DEVELOPMENT DOCUMENT
FOR PROPOSED
EFFLUENT LIMITATIONS GUIDELINES,
NEW SOURCE PERFORMANCE STANDARDS,
AND
PRETREATMENT STANDARDS
FOR"THE
STEAM ELECTRIC
POINT SOURCE CATEGORY
Douglas M. Costle
Administrator
Robert B. Schaffer
Director, Effluent Guidelines Division
John Lum
Senior Project Officer
Teresa Wright
Project Officer
September 1980
Effluent Guidelines Division
Office of Water and Waste Management
U.S. Environmental Protection Agency
Washington, D.C. 20460
-------
-------
TABLE OF CONTENTS
Page
• •,"-".^' "'•'•,"'-'
I CONCLUSIONS 1
II RECOMMENDATIONS 3
III INTRODUCTION 15
BACKGROUND , 15
OF THIS SUPPLEMENT 15 .
INFORMATION AVAILABILITY, SOURCES AND
COLLECTION , 23
INDUSTRY DESCRIPTION 27
PROCESS DESCRIPTION . 31
ALTERNATE PROCESSES UNDER ACTIVE DEVELOPMENT 39
FUTURE GENERATING SYSTEMS 40
IV INDUSTRY CATEGORIZATION. 43
STATISTICAL ANALYSIS '..... 44
ENGINEERING TECHNICAL ANALYSIS 47
V WASTE CHARACTERIZATION 51
INTRODUCTION 51
DATA COLLECTION. ..: 51
COOLING WATER 59
ASH HANDLING 116
LOW VOLUME WASTES 173
METAL CLEANING WASTES 192
COAL PILE RUNOFF 212
VI SELECTION OF POLLUTANT PARAMETERS 233
-------
TABLE OF CONTENTS (CONTINUED)
Page
VII TREATMENT AND CONTROL TECHNOLOGY. . 249
INTRODUCTION. ....... 249
COOLING WATER. 249
ASH HANDLING , 305
LOW-VOLUME WASTES , . 401
METAL CLEANING WASTES 406
COAL PILE AND CHEMICAL HANDLING RUNOFF 419
VIII COST, ENERGY, AND NON-WATER QUALITY ASPECTS..... 421
COOLING WATER 421
ASH HANDLING 432
LOW VOLUME-WASTES 445
COAL PILE RUNOFF .... • 449
IX BEST AVAILABLE TECHNOLOGY ECONOMICALLY
ACHIEVABLE GUIDELINES AND LIMITAITONS, AND
NEW SOURCE PERFORMANCE STANDARDS AND
PRETREATMENT STANDARDS 455
ONCE-THROUGH COOLING WATER 455
COOLING TOWER SLOWDOWN. 460
ASH TRANSPORT WATER 463
METAL CLEANING WASTES 469
LOW-VOLUME WASTES 469
X ACKNOWLEDGEMENTS , 471
XI REFERENCES 475
XII GLOSSARY 487
ii
-------
TABLE OF' CONTENTS (CONTINUED)
APPENDIX
A TVA RAW RIVER INTAKE AND ASH POND DISCHARGE
DATA ....... ............ .. ........................ 513
B CHLORINE MINIMIZATION PROGRAM FOR ONCE-
THROUGH COOLING WATER. .............. ---- . ....... 572
C STATISTICAL EVALUATION OF CHLORINE MINIMIZA-
TION AND DECHLORINATION . ---- ...... ... ........... 584
iii
-------
LIST OF TABLES
Number
II-1 RECOMMENDED BAT GUIDELINES AND PRETREATMENT
STANDARDS FOR NEW AND EXISTING SOURCES 4
II-2 TECHNOLOGIES EVALUATED AS CAPABLE OF ACHIEVING
RECOMMENDED LIMITATIONS 8
II-3 EXISTING BPT GUIDELINES AND PRETREATMENT
STANDARDS FOR NEW AND EXISTING SOURCES 10
III-l LIST OF SIXTY-FIVE CLASSES OF POLLUTANTS
CONTAINED IN SETTLEMENT AGREEMENT BETWEEN
EPA. AND NRDC 16
III-2 LIST OF 129 PRIORITY POLLUTANTS 18
III-3 DISTRIBUTION OF THE STEAM SECTION RELATIVE TO
THE ENTIRE ELECTRIC UTILITY INDUSTRY AS OF 1978. 28
III-4 YEAR-END 1978 DISTRIBUTION OF STEAM ELECTRIC
PLANTS BY SIZE CATEGORY 29
III-5 PRESENT AND FUTURE CAPACITY OF THE ELECTRIC
UTILITY INDUSTRY 30
III-6 NUMBER OF EXISTING STEAM-ELECTRIC POWERPLANTS
BY FUEL TYPE AND SIZE 32
III-7 CAPACITY OF EXISTING AND NEW STEAM-ELECTRIC
POWERPLANTS BY FUEL TYPE AND SIZE....... 33
III-8 EXISTING AND PROJECTED DISTRIBUTION OF STEAM
ELECTRIC POWERPLANTS BY FUEL TYPE 34
III-9 DISTRIBUTION OF STEAM-ELECTRIC CAPACITY BY
PLANT SIZE AND IN-SERVICE YEAR 35
IV-1 VARIABLES FOUND TO HAVE A STATISTICALLY
SIGNIFICANT INFLUENCE ON NORMALIZED FLOW
DISCHARGES . 45
IV-2 PERCENT OF THE VARIATION IN NORMALIZED
DISCHARGE FLOWS THAT IS EXPLAINED BY THE
INDEPENDENT VARIABLES 46
-------
LIST OF TABLES (Continued)
Number
V-l CHARACTERISTICS OF PLANTS SAMPLED IN THE
SCREEN SAMPLING PHASE OF THE SAMPLING PROGRAM... 54
V-2 CHARACTERISTICS OF PLANTS SAMPLED IN THE
VERIFICATION PHASE. ,. 56
V-3 SUMMARY TABLE OF ALL PRIORITY POLLUTANTS
DETECTED IN ANY OF THE WASTE STREAMS FROM
STEAM ELECTRIC POWERPLANTS BASED ON THE ANALYSIS
OF THE COMPLETE COMPUTERIZED DATA BASE 60
V-4 ONCE-THROUGH COOLING WATER FLOW RATES 62
V-5 COOLING TOWER SLOWDOWN 67
V-6 COPPER CORROSION DATA........ .'..' 79
V-7 ONE YEAR STEADY STATE CORROSION RATES FOR
ALLOY 706 DETERMINED EXPERIMENTALLY 81
V-8 SELECTED PRIORITY POLLUTANT CONCENTRATIONS
IN SEAWATER BEFORE AND AFTER PASSAGE THROUGH
ONCE-THROUGH COOLING WATER SYSTEM. 82
V-9 SOLUBLE COPPER CONCENTRATIONS IN RECIRCULATING
COOLING WATER SYSTEMS 83
V-10 COMMONLY USED CORROSION AND SCALING CONTROL
CHEMICALS 84
V-ll SOLVENT OR CARRIER COMPONENTS THAT MAY BE USED
IN CONJUNCTON WITH SCALING AND CORROSION
CONTROL AGENTS 88
V-l2 POLLUTANTS REPORTED ON 308 FORMS IN COOLING
TOWER SLOWDOWN 89
V-13 ASBESTOS IN COOLING TOWER WATERS 90
V-14 RESULTS OF SCREENING PROGRAM FOR ONCE-THROUGH
COOLING WATER SYSTEMS 93
V-15 OF DATA FROM THE VERIFICATION PROGRAM
AND EPA SURVEILLANCE AND ANALYSIS REPORTS FOR
ONCE-THROUGH COOLING WATER SYSTEMS 94
-------
LIST OF TABLES (Continued)
Number Page
V-16 RESULTS OF THE SCREENING PHASE OF THE SAMPLING
PROGRAM FOR COOLING TOWER SLOWDOWN 103
V-17 SUMMARY OF RESULTS OF VERIFICATION PROGRAM FOR
RECIRCULATION COOLING WATER SYSTEMS 107
V-18 FLY ASH POND OVERFLOW 117
V-19 BOTTOM ASH POND OVERFLOW 118
V-20 VANADIUM, NICKEL, AND SODIUM CONTENT OF
RESIDUAL FUEL OIL 120
V-21 AVERAGE PRODUCT YIELD OF A MODERN UNITED
STATES REFINERY 121
V-22 SULFUR CONTENT IN FRACTIONS OF KUWAIT CRUDE
OIL 122
V-23 MELTING POINTS OF SOME OIL/ASH CONSTITUENTS 124
7-24 MEGATONS OF COAL ASH COLLECTED IN THE
UNITED STATES 126
V-25 VARIATIONS IN COAL ASH COMPOSITION WITH
RANK. 127
V-26 RANGE IN AMOUNT OF TRACE ELEMENTS PRESENT IN
COAL ASHES 128
V-27 COMPARISON OF DISTRIBUTION BETWEEN BOTTOM ASH
AND FLY ASH BY TYPE OF BOILERS AND METHOD OF
FIRING 133
V-28 MAJOR CHEMICAL CONSTITUENTS OF FLY ASH AND
BOTTOM ASH FROM THE SOUTHWESTERN PENNSYLVANIA
REGIONS ., 134
V-29 COMPARISON OF FLY ASH AND BOTTOM ASH FROM
VARIOUS UTILITY PLANTS. 135
V-30 CONCENTRATIONS OF SELECTED TRACE ELEMENTS IN
COAL AND ASH AT PLANT 4710....... 137
-------
LIST OF TABLES (Continued)
Number Page
V-31 ELEMENTS SHOWING PRONOUNCED CONCENTRATION
TRENDS WITH DECREASING PARTICLE SIZE 140
V-32 CHARACTERISTICS OF ASH POND OVERFLOW WITH
TOTAL SUSPENDED SOLIDS CONCENTRATIONS LESS
THAN 30 mg/1 141
V-33 SUMMARY OF ASH POND OVERFLOW DATA FROM
DISCHARGE MONITORING REPORTS 142
V-34 SUMMARY OF QUARTERLY TVA TRACE METAL DATA FOR
ASH POND INTAKE AND EFFLUENT STREAMS 143
V-35 SUMMARY OF PLANT OPERATION CONDITIONS AND ASH
CHARACTERISTICS OF TVA COAL-FIRED POWER
PLANTS 149
V-36 NUMBER OF ASH PONDS IN WHICH AVERAGE EFFLUENT
CONCENTRATIONS OF SELECTED TRACE ELEMENTS
EXCEED THOSE OF THE INTAKE WATER • 15°
V-37 SUMMARY OF QUARTERLY TRACE METAL DATA FOR ASH
POND INTAKE AND EFFLUENT STREAMS 151
V-38 SUMMARY OF PLANT OPERATING CONDITIONS AND ASH
CHARACTERISTICS OF TVA COAL-FIRED POWERPLANTS 154
V-39 ASH POND EFFLUENT TRACE ELEMENT
CONCENTRATIONS 156
V-40 SCREENING DATA FOR ASH POND OVERFLOW 157
V-41 SUMMARY OF DATA FROM THE VERIFICATION PROGRAM
AND EPA SURVEILLANCE AND ANALYSIS REPORTS FOR
ASH POND OVERFLOW 160
V-42 CONDITIONS UNDER WHICH ARSENIC IN ASH POND
OVERFLOW EXCEEDS 0.05 mg/1. 171
V-43 ARSENIC CONCENTRATIONS IN ASH POND
EFFLUENTS . 172
V-44 RECOMMENDED LIMITS OF TOTAL SOLIDS IN BOILER
WATER FOR DRUM BOILERS 174
vii
-------
LIST OF TABLES (Contimied)
Number
V-45 CHEMICAL ADDITIVES COMMONLY ASSOCIATED WITH
INTERNAL BOILER TREATMENT 175
V-46 STATISTICAL ANALYSIS OF BOILER SLOWDOWN
CHARACTERISTICS........... 176
V-47 BOILER SLOWDOWN FLOWRATES 178
V-48 SURVEILLANCE AND ANALYSIS DATA FOR BOILER
SLOWDOWN 179
V-49 COAGULATING AND FLOCCULATING AGENT
CHARACTERISTICS . 182
V-50 CLARIFIER SLOWDOWN FLOWRATES 183
V-51 FILTER BACKWASH FLOWRATES 184
V-52 ION EXCHANGE MATERIAL TYPES AND REGENERANT
REQUIREMENT 186
V-53 ION EXCHANGE SPENT REGEN1RANT CHARACTERISTICS.... 187
V-54 ION EXCHANGE SOFTENER SPENT REGENERANT
FLOWRATES 188
V-55 LIME SOFTENER SLOWDOWN FLOWRATES 189
V-56 EVAPORATOR SLOWDOWN CHARACTERISTICS 190
7-57 EVAPORATOR SLOWDOWN FLOWRATES 191
V-58 REVERSE OSMOSIS BRINE FLOWRATES 193
V-59 EQUIPMENT DRAINAGE AND LEAKAGE. 194
V-60 SURVEILLANCE AND ANALYSIS DATA FOR
DEMINERALIZER REGENERANT 195
V-61 ALLOYS AND CONSTITUENTS OF BOILER SYSTEMS 201
V-62 WASTE CONSTITUENTS OF AMMONIATED CITRIC ACID
SOLUTIONS 203
V-63 WASTE CONSTITUENTS OF AMMONIATED EDTA
SOLUTIONS 204
viii
-------
LIST OF TABLES (Continued)
Number
V-64 WASTE CONSTITUENTS OF AMMONIACAL SODIUM
BROMATE SOLUTIONS 205
V-65 WASTE CONSTITUENTS OF HYDROCHLORIC ACID WITHOUT
COPPER COMPLEXER SOLUTIONS 207
V-66 WASTE CONSTITUENTS OF HYDROCHLORIC ACID WITH
COPPER COMPLEXER SOLUTIONS '..... 209
V-67 WASTE CONSTITUENTS ;OF HYDROXYACETIC/FORMIC
ACID SOLUTIONS , 210
V-68 AVERAGE AND MAXIMUM CONCENTRATIONS AND LOADING
IN EAW WASTEWATER FROM FIRESIDE WASHES AT
PLANT 3306. 213
V-69 WASTE LOAD DATA FOR BOILER FIRESIDE WASH 214
V-70 FIRESIDE WASH WATER FLOWRATES 215
V-71 AIR PREHEATER WASH WATER. 216
V-72 WASTE LOAD DATA FOR AIR PREHEATER WASH 217
V-73 AIR PREHEATER WASHWATER FLOWRATES 218
V-74 CHARACTERISTICS OF COAL PILE RUNOFF 221
V-75 CONCENTRATIONS OF METALS IN COAL PILE
222
V-76 SUMMARY OF NEW AND RETROFIT FGD SYSTEMS BY
PROCESS o „ 224
V-77 COMPOSITION OF EFFLUENT FROM ONCE-THROUGH
MIST ELIMINATOR WASH UNIT AT WET LIMESTONE
SCRUBBER SYSTEM. 226
V-78 RANGE OF CONCENTRATIONS OF CHEMICAL CONSTITUENTS
IN FGD SLUDGES LIME/LIMESTONE, AND DOUBLE-
ALKALI SYSTEMS 229
V-79 FLUE GAS SCRUBBER SLOWDOWN 230
V-80 FLUE GAS SCRUBBER SOLIDS POND OVERFLOW...... 231
ix
-------
LIST OF TABLES (Continued)
Number
¥1-1 PRIORITY POLLUTANTS DETECTED IN THE SAMPLING
PROGRAM BY WASTE STREAM SOURCES 235
VI-2 NUMBER OF PLANTS REPORTING VARIOUS PRIORITY
POLLUTANTS AS OR SUSPECTED TO BE PRESENT
IN VARIOUS WASTE STREAMS ... , 240
VI-3 PRIORITY POLLUTANT CONTAINING PROPRIETARY
CHEMICALS USED BY POWER PLANTS 243
VI-4 WATER QUALITY AND HUMAN HEALTH CRITERIA USED
IN ASSESSMENT OF ENVIRONMENTAL SIGNIFICANCE OF
POWER PLANT EFFLUENTS 246
VII-1 TOTAL RESIDUAL CHLORINE DATA REPORTED IN
CHLORINE MINIMIZATION STUDIES , . 262
VII-2 SULFUR DIOXIDE DECHLORINATION SYSTEMS IN USE OR
CONSTRUCTION AT U.S. STEAM ELECTRIC
PLANTS , 269
VII-3 CHLORINATED CONDENSER OUTLET FIELD DATA FROM
PLANT 0611 270
VII-4 UNCHLORINATED CONDENSER OUTLET FIELD DATA FROM
PLANT 0611 271
VII-5 DECHLORINATED EFFLUENT DATA FIELD DATA FOR
PLANT 0611 . 272
VII-6 DRY CHEMICAL DECHLORINATION SYSTEMS IN USE OR
UNDER CONSTRUCTION AT U.S. STEAM ELECTRIC
PLANTS 277
VII-7 CHLORINATION/DECHLORINATION PRACTICES 278
VII-8 EFFECT OF DRY CHEMICAL DECHLORINATION ON PH
OF THE COOLING WATER... 280
-------
LIST OF TABLES (Continued)
Number " •Page
711-9 EFFECT OF DRY CHEMICAL DECHLORINATION ON
DISSOLVED OXYGEN IN COOLING WATER........... 281
VII-10 CORROSION AND SCALING CONTROL MIXTURES KNOWN
TO CONTAIN PRIORITY POLLUTANTS....... .. .. 299
VII-11 COMMONLY USED OXIDIZING BIOCIDES 300
VII-12 COMMONLY USED NON-OXIDIZING BIOCIDES. 302
VII-13 ASH CONVEYING CAPACITIES OF VARIOUS SIZE PIPES... 315
VII-14 PLANTS WITH RETROFITTED DRY FLY ASH HANDLING
SYSTEMS ...... ^ 336
VII-15 ARSENIC REMOVAL FROM MUNICIPAL WASTEWATERS 351
VII-16 SUMMARY OF NICKEL CONCENTRATIONS IN METAL
PROCESSING AND PLATING WASTEWATERS.'...' . 352
VII-17 SUMMARY OF EFFLUENT NICKEL CONCENTRATIONS ' .
AFTER PRECIPITATION TREATMENT 353
\- •
VII-18 CONCENTRATIONS OF ZINC IN PROCESS WASTEWATERS '355
VII-19 SUMMARY OF PRECIPITATION TREATMENT RESULTS FOR
ZINC. 356
VII-20 COPPER CONCENTRATIONS IN WASTEWATER FROM METAL
PLATING AND PROCESSING OPERATIONS 356
VII-21 COPPER REMOVAL BY. FULL-SCALE INDUSTRIAL
WASTEWATER TREATMENT SYSTEMS 357
VII-22 COMPARISON OF INITIAL TRACE METAL CONCENTRATIONS
CITED IN STUDIES REPORTED IN THE LITERATURE AND
TRACE METAL CONCENTRATIONS IN ASH POND
DISCHARGES 361
VII-23 TRACE METAL REMOVAL EFFICIENCIES FOR LIME
PRECIPITATION TREATMENT OF ASH POND EFFLUENTS.... 362
-------
LIST OF TABLES (Continued)
Number
Page
VII-24 TRACE METAL REMOVAL EFFICIENCIES FOR LIME PLUS
FERRIC SULFATE PRECIPITATION TREATMENT OF ASH
POND EFFLUENTS 363
VII-25 DATA SUMMARY OF PLANTS REPORTING ZERO DISCHARGE
OF BOTTOM ASH TRANSPORT WATER.................... 375
VII-26 TRACE ELEMENTS/PRIORITY POLLUTANTS
CONCENTRATIONS AT PLANT 3203 385
VII-27 MAJOR SPECIES CONCENTRATION AT PLANT 3203 386
VII-28 TRACE ELEMENTS PRIORITY POLLUTANTS
CONCENTRATIONS AT PLANT 0822...; 391
VII-29 MAJOR SPECIES CONCENTRATIONS AT PLANT 0822....... 392
VII-30 TRACE ELEMENTS PRIORITY POLLUTANTS
CONCENTRATIONS AT PLANT 1811 397
VII-31 MAJOR SPECIES POLLUTANTS CONCENTRATIONS
AT PLANT 1811 398
VII-32 TRACE ELEMENTS/PRIORITY POLLUTANTS
CONCENTRATIONS AT PLANT 1809 . 402
VII-33 MAJOR SPECIES CONCENTRATIONS AT PLANT 1809 403
VII-34 TREATMENT OF ACID CLEANING WASTEWATER SUMMARY
OF JAR TESTS 416
VII-35 EQUIVALENT TREATMENT OF INCINERATION TESTS... 418
VII-36 PHYSICAL/CHEMICAL TREATMENT PROCESSES AND
EFFICIENCIES 420
VIII-1 SUMMARY OF COST, ENERGY, AND LAND REQUIREMENTS
FOR CHLORINE MINIMIZATION IN ONCE-THROUGH
COOLING WATER SYSTEMS 422
VIII-2 SUMMARY OF COST, ENERGY, AND LAND REQUIREMENTS
FOR DECHLORINATION IN ONCE-THROUGH COOLING
WATER SYSTEMS 422
xii
-------
LIST OF TABLES (Continued)
Number
VIII-3 SUMMARY OF COST, ENERGY AND LAND REQUIREMENTS
FOR BIOFOULING CONTROL WITH CHLORINE DIOXIDE
IN ONCE-THROUGH COOLING WATER SYSTEMS 424
VIII-4 SUMMARY COST, ENERGY AND LAND REQUIREMENTS
FOR BIOFOULING CONTROL WITH BROMINE CHLORIDE
IN ONCE-THROUGH COOLING WATER SYSTEMS 424
VIII-5 SUMMARY COST, ENERGY, AND LAND REQUIREMENTS
FOR BIOFOULING CONTROL WITH OZONE IN ONCE-
THROUGH COOLING WATER SYSTEMS 425
VIII-6 SUMMARY COST, ENERGY AND LAND REQUIREMENTS
FOR DECHLORINATION OF RECIRCULATING COOLING
SYSTEM DISCHARGE (SLOWDOWN) . 425
VIII-7 SUMMARY COST, ENERGY AND LAND REQUIREMENTS
FOR VAPOR COMPRESSION DISTILLATION OF COOLING
TOWER SLOWDOWN. ... . 427
VIII-8 SUMMARY COST, ENERGY AND LAND REQUIREMENTS
FOR BIOFOULING CONTROL WITH CHLORINE DIOXIDE
IN RECIRCULATING COOLING SYSTEMS 427
VIII-9 SUMMARY COST, ENERGY AND LAND REQUIREMENTS
FOR- BIOFOULING CONTROL WITH BROMINE CHLORIDE
IN RECIRCULATING COOLING SYSTEMS.., . 428
VIII-10 SUMMARY COST, ENERGY AND LAND REQUIREMENTS
FOR BIOFOULING CONTROL WITH OZONE IN
RECIRCULATING COOLING SYSTEMS... 428
VIII-11 SUMMARY COST, ENERGY AND LAND REQUIREMENTS
FOR SWITCHING TO NON-PRIORITY CONTAINING
NON-OXIDIZING BIOCIDES ... 430
VIII-12 SUMMARY COST, ENERGY AND LAND REQUIREMENTS
FOR SWITCHING TO NON-PRIORITY POLLUTANT
CONTAINING CORROSION AND SCALE CONTROL
CHEMICALS 430
VIII-13 COOLING TOWER FILL REPLACEMENT COSTS............. 431
xa.il.
-------
LIST OF TABLES (Continued)
Number
VIII-14 CAPITAL COSTS FOR DRY FLY ASH HANDLING SYSTEMS... 434
VIH-15 ANNUAL OPERATING AND MAINTENANCE COST FOR DRY
FLY ASH HANDLING SYSTEMS t 434
VIII-16 ENERGY REQUIREMENTS FOR DRY FLY ASH HANDLING
SYSTEMS 436
VIII-17 LAND REQUIREMENTS FOR DRY FLY ASH HANDLING
SYSTEMS 436
VIII-18 CAPITAL COSTS FOR PARTIAL RECIRCULATING AND
CHEWMICAL PRECIPITATION OF ONCE-THROUGH FLY
ASH SLUICING SYSTEMS 437
VIII-19 OPERATING AND MAINTENANCE COSTS FOR PARTIAL
RECYCLE AND CHEMICAL PRECIPITATION OF ONCE-
THROUGH FLY ASH SLUICING SYSTEMS 438
VIII-20 ENERGY REQUIREMENTS FOR PARTIAL RECIRCULATING
AND WET CHEMICAL PRECIPITATION OF ONCE-THROUGH
FLY ASH SLUICING SYSTEMS .• 439
VIII-21 LAND REQUIREMENTS FOR PARTIAL RECIRCULATING
AND CHEMICAL PRECIPITATION OF ONCE-THROUGH
FLY ASH HANDLING SYSTEMS 440
VIII-22 CAPITAL COSTS FOR COMPLETE RECYCLE BOTTOM
ASH HANDLING SYSTEM 440
VIII-23 OPERATING AND MAINTENANCE COSTS FOR COMPLETE
RECYCLE BOTTOM ASH HANDLING SYSTEM 443
VIII-24 ENERGY REQUIREMENTS FOR COMPLETE RECYCLE
BOTTOM ASH HANDLING SYSTEM , 443
VIII-25 LAND REQUIREMENTS FOR COMPLETE RECYCLE BOTTOM
ASH HANDLING SYSTEM ... 444
VIII-26 CAPITAL COSTS FOR PARTIAL RECYCLE BOTTOM ASH
HANDLING SYSTEM . 444
VIII-27 OPERATING AND MAINTENANCE COSTS FOR PARTIAL
RECYCLE BOTTOM ASH HANDLING SYSTEM 446
xiv
-------
LIST OF TABLES (Continued)
Number
VIII-28 ANNUAL ENERGY REQUIREMENTS FOR PARTIAL RECYCLE
BOTTOM ASH HANDLING SYSTEM, 446
VIII-29 LAND REQUIREMENTS FOR PARTIAL RECYCLE BOTTOM
AHS BALDING SYSTEMS .. 447
VIII-30 IMPOUNDMENT COST. .. . . 447
VIII-31 COST OF VAPOR COMPRESSION EVAPORATION SYSTEM..... 448
VIII-32 COST OF EVAPORATION PONDING 448
VIII-33 COST OF SPRAY DRYING SYSTEM 450
VIII-34 COST OF IMPOUNDMENT FOR COAL PILE RUNOFF..». 450
VIII-35 COST OF LIME FEED SYSTEM 451
VIII-36 COST OF MIXING EQUIPMENT. 451
VIII-37 CLARIFICATION 452
VIII-38 COST FOR LIME FEED SYSTEM. 452
VIII-39 COST OF POLYMER FEED SYSTEM 454
VIII-40 COST OF ACID FEED SYSTEM 454
A-l TVA PLANT A RIVER WATER INTAKE AND FLY ASH
POND DISCHARGE DATA 514
A-2 TVA PLANT A RIVER WATER INTAKE AND BOTTOM ASH
POND DISCHARGE DATA 518
A-3 TVA PLANT B RIVER WATER INTAKE AND FLY ASH
POND DISCHARGE DATA ,. 522
A-4 TVA' PLANT B RIVER WATER INTAKE AND BOTTOM ASH
POND DISCHARGE DATA. 525
A-5 TVA PLANT C RIVER WATER INTAKE AND COMBINED
ASH POND (EAST) DISCHARGE DATA 528
A-6 TVA PLANT C RIVER WATER INTAKE AND COMBINED
ASH POND (WEST) DISCHARGE DATA 532
-------
LIST OF TABLES (Continued)
Number • Page
A-7 TVA PLANT D RIVER WATER INTAKE AND COMBINED
ASH POND DISCHARGE DATA 536
A-8 TVA PLANT E RIVER WATER INTAKE AND COMBINED
ASH POND DISCHARGE DATA 540
A-9 TVA PLANT F RTVER WATER INTAKE AND COMBINED
ASH POND DISCHARGE DATA 544
A-10 TVA PLANT G RIVER WATER INTAKE AND COMBINED
ASH POND DISCHARGE DATA 548
A-11 TVA PLANT H RIVER WATER INTAKE AND COMBINED
ASH POND DISCHARGE DATA 552
A-12 TVA PLANT H RIVER WATER INTAKE AND FLY ASH
POND DISCHARGE DATA 555
A-13 TVA PLANT H RIVER WATER INTAKE AND BOTTOM ASH
POND DISCHARGE DATA 556
A-14 - TVA PLANT I RIVER WATER INTAKE AND COMBINED
ASH POND (SOUTH) DISCHARGE 557
A-15 TVA PLANT J RIVER WATER INTAKE AND COMBINED
' ASH POND DISCHARGE 561
A-16 TVA PLANT K RIVER WATER INTAKE AND COMBINED
ASH POND DISCHARGE 565
A-17 TVA PLANT L RIVER WATER INTAKE AND COMBINED
ASH POND DISCHARGE 569
C-l RECOMMENDED STANDARDS: TRC (mg/1) 585
C-2 THE NUMBER OF OF CHLORINATION ............. 586
C-3 PERCENTAGE OF AVERAGE (X) AND MAXIMUM (MAX.)
VALUES EQUALING ZERO 587
C-5 WEIGHTED MEAN: TRC (mg/1) 591
C-6 STANDARD DEVIATION 595
xva.
-------
LIST OF TABLES (Continued)
Number . Page
C-7 WEIGHTED MEANS AND MEDIAN OF ESTIMATED
STANDARD DEVIATION FOR TREATMENT TYPE
(PLANT INDEPENDENT) 5»6
C-8 COMPUTATION OF ? .99nl 597
x .
C-9 99th PERCENTILE ESTIMATES FOR A DAILY MAXIMUM... 597
-------
LIST OF FIGURES
Figure > Page
III-l TYPICAL COAL-FIRED STEAM ELECTRIC PLANT.......... 37
V-l SOURCES OF WASTEWATER IN A FOSSIL-FUELED
STEAM ELECTRIC POWER PLANT 52
V-2 SHELL AND TUBE CONDENSER.- ... 61
V-3 MECHANICAL DRAFT COOLING TOWERS 64
V-4 NATURAL DRAFT EVAPORATIVE COUNTERFLOW COOLING
TOWER .. 65
V-5 EFFECT OF pH ON THE DISTRIBUTION OF HYPOCHLOROUS
ACID AND HYPOCHLORITE ION IN WATER 69
V-6 EFFECT OF IMPURITIES IN WATER ON TOTAL
AVAILABLE CHLORINE RESIDUAL 72
V-7 FREQUENCY DISTRIBUTION OF HALOGENATED ORGANICS
IN RAW AND FINISHED DRINKING WATER. 73
V-8 EFFECT OF WATER TEMPERATURE ON THE CHLOROFORM
REACTION. .. .. 75
V-9 EFFECT OF pH ON THE CHLOROFORM REACTION.......... 76
V-10 EFFECT OF CONTACT TIME ON THE CHLOROFORM
REACTION 77
V-ll PULVERIZED-COAL FIRING METHODS ,. 132
V-12 GRAIN SIZE DISTRIBUTION CURVES FOR BOTTOM ASH
AND FLY ASH 139
VII-1 LIQUID SUPPLY CHLORINATION SYSTEM 253
VII-2 SCHEMATIC DIAGRAM OF A TYPICAL CHLORINATOR 254
VII-3 PROCEDURE FOR CONDUCTING A SET OF SCREENING
TRIALS TO CONVERGE ON THE MINIMUM VALUE FOR
TRC LEVEL, DURATION OF CHLORINATION, AND
CHLORINATION FREQUENCY 260
VII-4 FLOW DIAGRAM FOR DECHLORINATION BY SULFUR
DIOXIDE (S02) INJECTION 265
xviii
-------
LIST OF FIGURES (Continued)
Figure ' Page
VII-5 FLOW DIAGRAM FOR DECHLORINATION BY DRY
CHEMICAL INJECTION 275
VII-6 DECHLORINATION BY NATURAL CHLORINE DEMAND IN A
ONCE-THROUGH COOLING WATER SYSTEM 283
VII-7 SIMPLIFIED, SCHEMATIC DIAGRAM OF A CHLORINE
DIOXIDE BIOFOULING CONTROL FACILITY BASED ON
THE CHLORINE GAS METHOD . 287
VII-8 SIMPLIFIED, SCHEMATIC DIAGRAM OF A CHLORINE
DIOXIDE BIOFOULING CONTROL FACILITY BASED ON
THE HYPOCHLORITE METHOD 288
VII-9 SCHEMATIC DIAGRAM OF CORONA CELL 291
VII-10 EFFECT OF OZONATION FACILITY CAPACITY ON
PROCESS CHOICE - OXYGEN VS. AIR 292
VII-11 OZONATION FACILITY USING AIR TO GENERATE
OZONE 294
VII-12 OZONATION FACILITY USING OXYGEN TO GENERATE
OZONE . . .. . 295
VII-13 SCHEMATIC ARRANGEMENT OF AMERTAP TUBE CLEANING
SYSTEM. 297
VII-14 SCHEMATIC OF M.A.N. SYSTEM REVERSE FLOW
PIPING 298
VII-15 DRY FLY ASH HANDLING - VACUUM SYSTEM 308
VII-16 DIAGRAM OF A HYDRAULIC VACUUM PRODUCER.. 310
VII-17 TYPE "E" DUST VALVES 311
VII-18 SEGREGATING VALVES 313
VI1-19 TYPICAL PIPES AND FITTINGS FOR ASH CONVEYING..... 314
VII-20 DRY FLY ASH HANDLING SYSTEM - PRESSURE SYSTEM 317
VII-21 TYPICAL AIR LOCK VALVE FOR PRESSURE FLY ASH
CONVEYING SYSTEM 319
XXX
-------
LIST OF FIGURES (Continued)
Figure
VII-22 FLY ASH SILO AND HOPPERS/PLANT 1811 322
VII-23 FLOW DIAGRAM FOR PLANT 0822 323
VII-24 PRESSURE FLY ASH HANDLING SYSTEM FOR PLANT 3203.. 326
VII-25 DISTRIBUTION OF FLY ASH HANDLING SYSTEMS BY
MAJOR FUEL TYPES.......... ....... 328
VII-26 DISTRIBUTION OF FLY ASH HANDLING SYSTEMS BY
COAL TYPE 329
VII-27 DISTRIBUTION OF FLY ASH HANDLING SYSTEMS BY
MAJOR BOILER TYPES 330
VII-28 DISTRIBUTION OF FLY ASH HANDLING SYSTEMS BY
EPA REGION 331
VII-29 EPA REGIONS 332
VII-30 DISTRIBUTION OF FLY ASH HANDLING SYSTEMS BY
VARIOUS PLANT SIZES 334
VII-31 DISTRIBUTION OF FLY ASH HANDLING SYSTEMS AS A
FUNCTION OF INTAKE WATER QUALITY 335
VII-32 GENERALIZED, SCHEMATIC DIAGRAM OF A PARTIAL
RECIRCULATION FLY ASH HANDLING SYSTEM 338
VII-33 A TYPICAL METHOD OF SLUICING FLY ASH FROM
COLLECTION POINTS 339
VII-34 TYPICAL AIR SEPARATOR IN A PARTIAL RECIRCULATING
FLY ASH HANDLING SYSTEM 340
VII-35 ASH HANDLING SYSTEM FLOW DIAGRAM AND SAMPLING
LOCATIONS FOR PLANT 1809 343
VII-36 FLOW DIAGRAM OF A TYPICAL PHYSICAL/CHEMICAL
TREATMENT SYSTEM FOR METALS REMOVAL USING LIME... 345
VII-37 TYPICAL LIME FEED SYSTEM 346
VII-38 DEEP BED FILTER. 348
-------
LIST OF FIGURES (Continued)
Figure ^ ' . Page
VII-39 LANDFILL METHODS . 365
VII-40 VARIOUS STAGES OF A CLOSED-LOOP REGIRCULATING
SYSTEM 367
VII-41 PONDING RECYCLE SYSTEM FOR BOTTOM ASH 372
VII-42 WATER FLOW DIAGRAM FOR PLANT 3203 381
VII-43 BOTTOM ASH RECYCLE SYSTEM AT PLANT 3203 382
VII-44 BOTTOM ASH HANDLING SYSTEM FOR PLANT 8022. 388
VII-45 PLANT 1811 FLOW DIAGRAM FOR BOTTOM ASH HANDLING.. 394
VII-46 SIMPLIFIED, SCHEMATIC DIAGRAM OF A VAPOR
COMPRESSION EVAPORATION UNIT 405
VII-47 TYPICAL PIPING DIAGRAM AND LOCATION FOR
INCINERATION OF BOILER CHEMICAL CLEANING
WASTES 408
VII-48 COMPLEXING OF Fe(III) 411
VII-49 THE CHELATE EFFECT ON COMPLEX FORMATION OF
Cu-aq2+ WITH MONODENTATE, BIDENTATE AND
TETRADENTATE AMINES 412
VII-50 TREATMENT SCHEME FOR METALS REMOVAL BY
PRECIPITATION FROM WASTE BOILER CLEANING
SOLUTION. 414
VII-51 THEORETICAL SOLUBILITIES OF METAL IONS AS
A FUNCTION OF pH. 415
C-l HISTOGRAMS FOR PLANT 2608 588
C-2 HISTOGRAMS FOR PLANT 2607 589
C-3 HISTOGRAMS FOR PLANT 2603. 590
C-4 EMPIRICAL DISTRIBUTION FUNCTIONS FOR PLANT 2608.. 592
C-5 EMPIRICAL DISTRIBUTION FUNCTIONS FOR PLANT 2607.. 593
C-6 EMPIRICAL DISTRIBUTION FUNCTIONS FOR PLANT 2603.. 594
xxa.
-------
-------
SECTION I
CONCLUSIONS
In revising effluent limitations guidelines and standards of per-
formance as well as pretreatment standards for the steam electric
power generating industry, separate consideration has been given to
heat and to chemical pollutants. In this regulation review, only non-
thermal-related pollutants :were considered. Another document will
address thermal discharges when thermal regulations are proposed.
The analysis of pollutants and the technologies applicable to their
control has been based on specific waste streams of concern. These
waste streams are primarily a function of fuels used, processes
employed, plant site characteristics, and intake water quality. The
major waste streams have been defined as direct or indirect products
of the treatment system, power cycle system, ash handling system, air
pollution control system, coal pile, yard and floor drainage,
condenser cooling system and miscellaneous sources. Virtually all
steam electric facilities have one or more waste streams associated
with these systems and sources.
This review of effluent guidelines focused primarily on the 129
priority pollutants, although other pollutants were also considered.
In general, very few of the organics in the list of 129 priority
pollutants were detected in quantifiable amounts. Inorganic priority
pollutants, however, are found in most waste streams. The review also
found that the chlorine (non-conventional pollutants) limitations in
the original guidelines were not sufficiently stringent.
Treatment and control technologies currently in use by certain
segments of the power industry could be applied to a greater number of
powerplants, reducing the discharge of pollutants. The best
practicable control technology currently available (BPTCA) will not be
changed with exception to provisions relating to boiler blowdown. The
best available technology economically achievable (BATEA), new source
performance standards (NSPS) and pretreatment standards for new (PSNS)
and existing sources (PSES) will be changed to reflect updated
information on control technology, waste characterization and other
factors.
Although zero discharge of bottom and fly ash handling waters can be
achieved by the use of complete recirculatirig or dry transport
systems, the Agency is not requiring zero discharge of bottom and fly
ash handling waters for existing facilities. However, zero discharge
of fly ash water will be required for new sources. The discharge of
priority pollutants as the result of the use of cooling tower
maintenance chemicals (which contain the 129 priority pollutants) can
be eliminated through proper selection of chemical additives;
discharge of chlorine residuals can be also reduced significantly by
chemical treatment and implementation of proper chlorine addition
procedures.
-------
Pretreatment standards for new and existing sources will require
control of discharges resulting from metal cleaning operations, ash
transport, and blowdown from cooling tower operations.
EPA has Teviewed all powerplant waste stre*ams in this regulation
review effort with the exception of ash pile, chemical handling and
construction area runoff and discharges from wet scrubbing systems for
air pollution control. Regulations for these streams will be proposed
when additional data become available. Additional data are also being
compiled on bottom and fly ash transport water. Regulations for .ash
transport streams may be revised upon review of the information.
-------
SECTION II
RECOMMENDATIONS
The effluent limitations guidelines and standards of performance and-
pretreatment standards for the steam electric power generating point
source category are summarized in table II-l. The technologies
available to achieve these guidelines are presented in table II-2,
These limitations are based on the findings and conclusions presented
in this report, and are proposed in compliance with the Federal Water
Pollution Control Act Amendments of 1977 (Clean Water Act).
For comparison, the current BPT guidelines are presented in Table II-
3. •
-------
Table II-1
RECOMMENDED BAT GUIDELINES AND PRETREATMENT STANDARDS
FOR NEW AND EXISTING SOURCES
Wastestreams
All Waste-
streams Except
Once Through
Cooling Water
Proposed BAT:
Existing Sources
pH 6-9
Proposed
Standards of
Performance:
NewSources
pH 6-9
Pretreatment
Standards:
Existing Sources (1)
pH not less than
5, unless special
case
Pretreatment
Standards:
New Sources (1)
pH 6-9
All Waste-
streams
No Discharge
PCB's
No Discharge
PCB's
No pollutants
may be introduced
to a POTW that
shall interfere
with operation or
performance of
that facility
No discharge of
PCB's
Copper (total)
1.0 mg/1
Oil and Grease
(O&G) 100 mg/1
No pollutants
may be intro-
duced to a
POTW that
shall inter-
fere with ope-
ration or per-
formance of
that facility
No discharge
PCB's
-------
Table II-1 (Continued)
RECOMMENDED BAT GUIDELINES AND PRETREATMENT STANDARDS
FOR NEW AND EXISTING SOURCES
Wastestreams
Once-Through
Cooling Water
Ul
Proposed BAT;
Exi s t ing Source s
Zero discharge'of
TRC except demon-
stration of need,
then not to exceed
0.14 mg/1 and dis-
charge of TRC lim-
ited to 2 hours
per day per dis-
charge point (un-
less crustacean
control is needed)
Proposed
Standards of
Performance:
New Sources
Zero discharge
of TRC~ except
demonstration
of need, then
not to exceed
0.14 mg/1 and
dicharge, of
TRC limited to
2 hours per day
per discharge
point (unless
crustacean con-
trol is needed)
Pretreatment
Standards:
ExistingSources (1)
As described under
all wastestreams
category
Pretreatment
Standards:
New Sources (1)
As described
under all •
wastestreams
category
Cooling Tower
Slowdown
TRC not to exceed
0.14 mg/1 (max);
No discharge of
the 129 priority
pollutants result-
ing from chemical
additives
TRC not to ex-
ceed 0.14 mg/1
(max); No dis-
charge of the
129 priority
pollutants re-
• suiting from
chemical
additives
No discharge of
the 129 priority
pollutants result-
ing from chemical
additives.
No discharge of
of the 129 pri-
ority pollutants
resulting from
chemical addi-
tives
-------
Table II-1 (Continued)
RECOMMENDED BAT GUIDELINES AND PRETREATMENT STANDARDS
FOR NEW AND EXISTING SOURCES
Wastestrearns
Bottom Ash
Transport
Water
Proposed BAT:
Existing Sources
Same as BPT
Proposed
Standards of
Performance:
Hew Sources
Same as BPT
Pretreatment
Standards:
Existing Sources (
As described under
all wastestrearns
category
Pretreatment
Standards:
New Sources (1)
As described
under all
wastestrearns
category
cy*
Fly Ash
Transport
Water
Same as BPT
Zero discharge
As described under
all wastestreams
category
Zero discharge
Metal Cleaning
Wastes
Same as BPT
Same as BPT
1 mg/1 Cu (max)
and as described
under all waste-
streams category
- Copper ("total)
1.0 mg/1
Low Volume
Wastes (to
include boiler
blowdown)
Same as BPT
Same as BPT
As described under
all wastestreams
category
As described
under all
wastestreams
category
-------
Table II-1 (Continued)
RECOMMENDED BAT GUIDELINES AND PRETREATMENT STANDARDS
FOR NEW AND EXISTING SOURCES
Wastegtreams
Ash Pile/
Construction
Runoff
Proposed BAT:
Existing Sources
Reserve for future
consideration
Proposed
Standards of
Performance:
NewSources
Reserve for
future con-
sideration
Pretreatment
Standards:
Existing Sources (1)
Reserve for future
consideration
Pretreatment
Standards:
New Sources (1)
Reserve for4
future con-
sideration
Coal Pile/
Chemical
Handling
Runoff
Same as BPT
Same as BPT
pH not less than
5; No discharge
that would cause
process upset
pH 6-9 (ex-
cept for 10-
year , 24-hour
rainfall event)
Slowdown for
Wet Air Pollu-
tion Control
Systems (other
than for partic-
ulate control)
Reserve for future
consideration
Reserve for
future con-
sideration
Reserve for future
consideration
Reserve for
future con-
sideration
NOTE; (1) - All indirect dischargers must comply with the general pretreatment
standards (40 CFR 403) in addition to the limitations specified
below,
-------
Table II-2
TECHNOLOGIES EVALUATED AS CAPABLE OF ACHIEVING RECOMMENDED LIMITATIONS
Wastestreams
Once-Through
Cooling Water
Cooling Tower
Slowdown
c» Bottom Ash
Transport
Water
Fly Ash
Transport
Water
Metal Clean-
ing Wastes
Low Volume
Waste
(includes
boiler
blowdown)
Proposed BAT:
Existing Sources
Chlorine Minimiza-
tion-Dechlorina-
tion
Dechlorination/
Use of alternative
chemicals
Sedimentation
Sedimentation
Chemical
Precipitation
Sedimentation
Proposed
Standards of
Performance;
New Sources
Chlorine Mini-
mization-
Dechlorination
Dechlorina-
tion/Use of
alternative
chemicals
Pretreatment
Standards:
Existing Sources
No treatment
required
Use of alternative
chemicals
Sedimentation Sedimentatipn
Dry transport
and disposal
Chemical
Precipitation
Sedimentation
Chemical Precipi-
tation
Sedimentation Sedimentation
Pretreatment
Standards:
New Sources
No treatment
required
Use of
alternative
chemicals
Sedimenta-
tion
Dry trans-
port and
disposal
Chemical
Precipita-
tion
Sedimenta-
tion
:c
-------
Table II-2 (Continued)
TECHNOLOGIES EVALUATED AS CAPABLE OF ACHIEVING RECOMMENDED LIMITATIONS
Wastestreams
Ash Pile/
Construction
Runoff
Coal Pile/
Chemical
Handling
Runoff
Slowdown from
Wet Air Pollu-
tion Control
Devices
Proposed BAT:
Existing Sources
Reserved for
future considera-
tion
pH adjustment,
sedimentation
Reserved for
future considera-
tion
Proposed
Standards of
Performance;
New Sources
Reserved for
future con-
sideration
pH adjustment,
sedimentation
Reserved for
future con-
sideration
Pretreatment
Standards:
Existing Sources
Reserved for
future considera-
tion
pH adjustment,
sedimentation
Reserved for
future considera-
tion
Pretreatment
Standards;
New Sources
Reserved for
future con-
sideration
pH adjust-
ment, sedi-
mentation
Reserved for
future con-
sideration
-------
Table II-3
EXISTING BPT GUIDELINES AND PRETREATMENT STANDARDS
FOR NEW ANa EXISTING SOURCES
Wastestrearns
Current BPT:
Existing Sources
All Waste- ,pH 6-9
streams Except
Once Through
Cooling Water
All Waste-
streams
No Discharge PCB's
Low Volume
Wastes
- TSS 100 tng/1 (one
day max.)
30 mg/1 (30 day
avg.)
- O&G 20 mg/1 (one
day max.)
15 mg/1 (30 day
avg.)
Pretreatment
Standards:
Existing Sources(2)
pH not less than 5,
unless special case
- No pollutants may be
introduced to a POTW
that shall interfere
with operation or per-
formance of that
facility
- No discharge of PCB's
- Copper (total) 1.0
mg/1
- Oil and Grease (O&G)
100 mg/1
As described under all
wastestreams category
Pretreatment
Standards;
New Sources (2)
For incompatible pol-
lutants (heavy metals,
toxic organics), the
pretreatment standards
for new sources are
identical to BPT
- No pollutants may
be introduced to a
POTW that shall
interfere with ope-
ration or perfor-
mance of that
facility
- No discharge of
PCBs
As described under all
wastestreams category
-------
Table II-3 (Continued)
EXISTING BPT GUIDELINES AND PRETREATMENT STANDARDS
FOR NEW AND EXISTING SOURCES
Wastestrearns
Combined Ash
Transport
Water
Bottom Ash
Transport
Water
Fly Ash
Transport
Water
Current BPT;
'Existing Sources
- TSS 100 mg/1 (one
day max.)
30 mg/1 (30
day avg.)
- O&G 20 mg/1 (one
day max.)
15 mg/1 (30
day avg.)
- TSS 100 ing/1 (one
day max.)
30 mg/1 (30
day max.)
- O&G 20 rag/1 (one
day max.)
15 mg/1 (30
day avg.)
- TSS 100 mg/1 (one
day max.)
30 mg/1 (30
day max.)
- O&G 20 mg/1 (one
day max.)
15 mg/1 (30
day max.)
Pretreatment
Standards:
Existing Sources (2)
As described under all
wastestrearns category
As described under all
wastestreams category
As described under all
wastestrearns category
Pretreatment
Standards:
New Sources (2)
As described under all
wastestrearns category
As described under all
wastestreams category
No discharge of TSS
or O&G (Note: This
portion of the fly
ash regulation was
remanded but is being
reproposed as in
Table I1-1)
-------
Table II-3 (Continued)
EXISTING BPT GUIDELINES AND PRETREATMENT STANDARDS
FOR NEW AND EXISTING SOURCES
Wastestrearns
Metal Clean-
ing Wastes
K5
Once Through
Cooling Water
Current BPT;
Existing Sources
- TSS 100 mg/1 (one
day max.)
30 mg/1 (30
day avg.)
- O&G 20 mg/1 (one
day max.)
15 mg/1 (30
day avg.)
- Copper (total)
1.0 mg/1 (one day
max. and 30 day
avg.)
- Iron (total)
1.0 mg/1 (one day
max. and 30 day
avg.)
Free Available Chlo-
rine - 0.5 mg/1 (max.)
0.2 mg/1 (avg.) and may
not be discharged from
any one unit more than
2 hours per day and BO
more than one unit at
a time may discharge
FAG (unless plant can
show reason why more
is needed)
Pretreatment
Standards:
Existing Sources (2)
As described under all
wastestreams category
- Copper (total)
1.0 mg/1
As described under all
wastestreams category.
No chlorine limitation,
Pretreatment
Standards:
New Sources (2)
As described under all
wastestreams category
- Copper (total)
1.0 mg/1
As described under
all wastestreams
category. No chlo-
rine limitation.
-------
Table II-3 (Continued)
EXISTING BPT GUIDELINES AND PRETREATMENT STANDARDS
FOR NEW AND EXISTING SOURCES
Wastestrearns
Cooling Tower
Blowdown
Boiler
Blowdown
Current BPT;
Existing Sources
Free Available Chlo-
rine - 0.5 mg/1 (max.)
0.2 mg/1 (avg.) and may
not be discharged from
any one unit more than
2 hours per day and no
more than one unit at
a time may discharge
FAC (unless plant can
show reason why more
is needed)
- TSS 100 mg/1 (one
day max.)
30 mg/1 (30
day avg.)
- O&G 20 mg/1 (one
day max.)
15 mg/1 (30
day avg.)
- Copper (total) 1.0
mg/1 (one day max.
and 30 day avg.)
- Iron (total) 1.0
mg/1 (one day max.
and 30 day avg.)
Note; The new proposed
regulations place this
stream under the low
volume wastes category
where only TSS and O&G
are regulated.
Pre treatment
Standards ;
Existing Sources
As described under all
wastestreams category.
No chlorine limitation,
As described under all
wastestreams category.
Note: The new proposed
regulations place this
stream under the low
volume wastes category.
Pretreatment
Standards;
NewSources (2)
No discharge of
materials added for
corrosion inhibition
including but not
limited to zinc,
chromium, phosphorus
Note; The new proposed
regulations place this
stream under the low
volume wastes category
where only TSS and O&G
are regulated
- Copper (total)
1.0 mg/1
-------
Table II-3 (Continued)
EXISTING BFT GUIDELINES AND PRETREATMENT STANDARDS
FOR HEW AND EXISTING SOURCES
Pretreatrnent Pretreatment
Current BPT: Standards: Standards:
Wasteatrearns Existing Sources Existing Sources (2) New Sources (2)
Coal Pile/ TSS not to exceed 50 pH not less than 5, As described under all
Chemical m§/l» pH 6-9 (except No discharge that would wastestreams category
Storage Area for 10-year, 24-hour cause process upset
Runoff rainfall events)
NOTE: (2) - All indirect dischargers must comply with the general pretreatment
standards (40 CFR 403) in addition to the limitations specified
below.
-------
SECTION III
INTRODUCTION
BACKGROUND
The primary effluent guidelines document for the steam electric power
industry (1) was prepared by Burns & Roe and published by the
Environmental Protection Agency (EPA) in October 1974. This document
still serves as the fundamental source of information for the industry
as to its process descriptions, wastewater quantities and
compositions, treatment and control technologies, and achievable
pollutant levels for conventional and nonconventional pollutants. A
supplemental document (2) prepared by Hittman Associates and published
by EPA provided information on pretreatment for wastewater discharged
by the steam electric industry to publicly owned treatment works
(POTW).
Subsequent to the publishing of the Burns & Roe document, three events
which have implications for the effluent limitations guidelines for
the steam electric power industry have occurred, First, the
Settlement Agreement on June 7, 1976 between the Natural Resources
Defense Council (NRDC) and EPA (3) requires that EPA develop and
promulgate effluent limitations guidelines reflecting best available
technology economically achievable (BATEA), standards of performance
for new sources, and pretreatment standards for new and existing
sources for 21 major industries, taking into account a, list of 65
classes of toxic pollutants. This list has now been modified to 129
specific priority pollutants. The original list of 65 classes of
pollutants appears in table III-l. The present list of 129 priority
pollutants is presented in table III-2. Second/ the U.S.Court of
Appeals ruling of July 16, 1976 (4) remanded for reconsideration
various parts of the October 1974 effluent limitations guidelines for
the steam electric industry. Third, the Clean Water Act Amendments of
1977 require the review and, if appropriate, revision of each effluent
standard periodically.
PURPOSE OF THIS SUPPLEMENT
This supplemental document provides a basis for the revision of
effluent limitations guidelines for the steam electric power industry.
It forms the technical basis for the revised steam electric power
generating effluent limitations based on the BATEA, new source
performance standards (NSPS) and pretreatment standards in conformance
with the June 7, 1976 Consent Decree.
The steam electric power •industry covered in this document is
classified in Standard Industrial Classification (SIC) Codes 4911 and
4931(5). Code 4911 encompasses establishments engaged in the
generation, transmission, and/or distribution of electric energy for
sale. Code 4931 encompasses establishments primarily engaged in
providing electric service in combination with other services, with
electric services as the major part though less than 95 percent of the
15
-------
Table III-1
LIST OF SIXTY-FIVE CLASSES OF POLLUTANTS CONTAINED IN
SETTLEMENT EPA AND NRDC (3)
Acenaphthene
Acrolein
Acrylonitrile
Aldrin/Dieldrin
Antimony and compounds*
Arsenic and compounds
Asbestos
Benzene
Benzidine
Beryllium and compounds
Cadmium and compounds
Carbon tetrachloride
Chlordane (technical mixture and metabolites)
Chlorinated benzenes (other than dichlorobenzenes)
Chlorinated ethanes (included 1,2-dichlorethane,
1 ,1 ,1-trichlorethane, and hexachloroethane)
Chloroalkyl ethers (Chloromethyl, chlorethyl, and mixed ethers)
Chlorinated naphthalene
Chlorinated Phenols (other than those listed elsewhere; includes
trichlorophenols and chlorinated cresols)
Chloroform
2-chlorophenol
Chromium and compounds
Copper and compounds
Cyanides
DDT and metabolites
Dichlorobenzenes (1,2-,1,3-, and 1,4-dichlorobenzenes)
Dichlorobenzidene
Dichloroethylenes (1 ,1-and 1,2-dichloroethylene)
2,4-dichlorophenol
Dichloropropane and dichloropropene
2,4-dimethylphenol
Dinitrotoluene
Diphenylhdrazine
Endosulfan and metabolites
Endrin and metabolites
Ethylbenzene
Fluoranthene
Haloethers (other than those listed elsewhere; includes
chlorophenylphenyl ethers, bromophenylphenyl ether, bis
(dischloroisopropyl) ether, bis-(chloroethoxy) methane and
polychlorinated diphenyly ethers)
-------
Table III-1 (Continued)
LIST OF SIXTY-FIVE CLASSES OF POLLUTANTS CONTAINED IN
SETTLEMENT AGREEMENT BETWEEN EPA AND NRDC (3)
Halomethanes (other than those listed elsewhere; includes
methylene chloride methylchloride, methylbromide, bromoform,
dichlorobromomethane, triehlororfluoromethane,
dichlorodifluoromethane)
Heptachlor and metabolites
Hexachlorobutadiene
Hexachlorocyclohexane (all isomers)
Hexachlorocyclopentadiene
Isophorone
Lead and compounds
Mercury and compounds
Naphthalene
Nickel and compounds
Nitrobenzene «
Nitrophenols (Including 2,4-dinitrophenol, dinitrocresol)
Nitrosamines , •....•
Pentachlorophenol
Phenol
Phthalate esters
Polychlorinated biphenyls (PBCs) ,
Polynuclear aromatic hydrocarbons (Including benzanthracenes,
benzopyrenes, benzofluoranthene, chrysense,
dibenzanthracenes» and indenopyrenes)
Selenium and compounds
Silver and compounds
2,3,7,8,-Tetrachlorodibenzo-p-dioxin (TCDD)
Tetrachloroethylene
Thallium and compounds
Toluene
Toxaphene
Trichloroethylene
Vinyl chloride
Zinc and compounds
*As used throughout this table the term "compounds" shall include
organic and inorganic compounds.
17
-------
Table III-2
LIST OF 129 PRIORITY POLLUTANTS (2)
Compound Name
1. *acenaphthene (B)***
2. *acrolein (v)***
3. *acrylonitrile (V)
4« *benzene (V)
5. *benzidene (B)
6. *earbon tetraehloride (tetrachloromethane) (V)
*Chlorinated benzenes (other than dichlorobenzenes)
7. chlorobenzene (V)
8. 1,2,4-trichlorobenzene (B)
9. hexachlorobenzene (B)
*Chlor_inated ethanes (including 1 ,2-dichloroethane,
T,1,1- trichloroethane and hexachloroethane)
10. 1,2-dichloroethane (V)
11. 1,1»1-trichlorethane (V)
12« Kexachlorethane (B)
13. 1,1-dichloroethane (V)
14. 1,1,2-trichloroethane (V)
15. 1,1,2,2-tetrachloroethane (V)
16. chloroethane (V)
*Chloroalkyl ethers (chlqromethyl, chloroethyl and
mixed ethers)
17. bis (chloromethyl) ether (B)
18. bis (2-chloroethyly) ether (B)
19. 2-chloroethyl vinyl ether (mixed) (V)
*Chlorinated naphtalene
20. 2-chloronaphthalene (B)
*Chlorinated phenols (other than those listed elsewhere;
includes trichlorophenols and chlorinated cresols)
21. 2,4,6-trichlorophenol (A)***
22. parachlorometa cresol (A)
23. *chloroform (trichloromethane) (V)
24. *2-chlorophenol (A)
13
-------
Table III-2 (Continued)
LIST OF 129 PRIORITY POLLUTANTS (2)
frpichlorobenzenes
25. 1,2-diehlorobenzene (B)
26. 1,3-dichlorobenzene (B)
2*7. 1 ,4-dichlorobenzene (B)
*Dichlgrobenz idine " • '-....
28. 3,3f-dichlorobenzidine (B) .
*Diehloroethylenes (1,1-dichloroethylene and
1,2-dichloroethylene)
29. 1,1-dichloroethylene (V)
30. 1,2-trans-dischloroethylene (V)
31. *2,4-dichlorophenol (A)
*Dichloropropane and' dichloropropene
32. 1 ,2-diehloropropane (V) ,
33. 1,2-dichloropropylene (1,3-dichloropropene) (V)
34. *2,4-dimenthylphenol (A)
*Dinitrotoluene . .
35. 2,4-dinitrotoluene (B)
36. 2,6,-dinitrotoluene (B)
37. *1,2-diphenylhydrazine (B)
38. *ethylbenzene (V) . • .
39. *fluoranthene (B)
*Haloethers (other than those listed elsewhere)
40., 4-chlorophenyl phenyl ether (B)
41, 4-bromophnyl phenyl ether (B)
42, bis(2-ehloroisopropyl) ether (B)
43. bis(2-chloroethoxy) methane (B)
*Halomethanes (other than those listed elsewhere)
44. methylene chloride (dichloromethane) (V)
45. methyl chloride (chloromethane) (V)
46. methyl bromide (bromomethane) (V)
47. bromoform (tribramomethane) (V)
48. dichlorobromomethane (V)
19
-------
Table III-2 (Continued)
LIST OF 129 PRIORITY POLLUTANTS (2)
49. trichlorofluoromethane (7)
50. dlchlorodifluoromethane (V)
51 . chlorodibrocaome thane (V)
52. *hexaehlorobutadiene (B)
53. *hexachlorocyclopentadiene (B)
54. *Isophorone (B)
55. *naphthalene (B)
56. *nitrobenzene (B)
*Nitrophenols (including 2,4-dinitrophenol and dinitrocesol)
57. 2~nitrophenol (A)
58. 4-nitrophenol (A)
59. *2,4-dinitrophenol (A)
60. 4»6-dinitro-o-cresol (A)
*Hitrosamines
61. N-nitrosodimethylamine (B)
62. N-nitrosodiphenylamine (B)
63. N-nitrosodi-n-propylamine (B)
64. *pentachlorophenol (A)
65. *phenol (A)
*Phthalate esters
66. bis(2-3ethylhexyl) phthalate (B)
67. butyl benzyl phthalate (B)
68. di-n-butyl phtalate (B)
69. di-n-octyl phtalate (B)
70. diethyl phtalate (B)
71. dimethyl phthalate (B)
*Polynuclear aromatic hydrocarbons
72. benzo (a)anthracene (1,2-benzanthracene) (B)
73. benzo (a)pyrene (3,4-benzopyrene) (B)
74. 3,4-benzofluoranthene (B)
75. benzo(k)fluoranthane (11,12-benzofluoranthene) (B)
76. chrysene (B)
77. acenaphthylene (B)
78. anthracene (B)
79. benzo(ghi)perylene (1,12-benzoperylene) (B)
80. fluroene (B)
81. phenathrene (B)
-------
Table III-2 (Continued)
LIST OF 129 PRIORITY POLLUTANTS (2)
82. dibenzo (a,h)anthracene (1,2,5,6-dibenzanthracene) (B)
83. indeno (1,2,3-cd)(2,3,-o-phenylenepyrene) (B)
84. pyrene (B)
85. *tetrachloroethylene (V)
86. *toluene (V)
87. *trichloroethylene (V)
88. *vinyl chloride (chloroethylene) (V)
Pesticides and Metabolites
89. *aldrin (P)
90. *dieldrin (P)
91. *chlordane (technical mixture and metabolites) (P)
*PDT and metabolites
92. 4,4'-DDT (P)
93. 4,4'-DDE(p,p'DDX) (P)
94. 4,4'-DDD(p,p'TDE) 9 (P)
*endosul£an and metabolites
95. a-endosulfan-Alpha (P)
96. b-endosulfan-Beta (P)
--97. endosulfan sulfate (P)
*endrin and metabolites
98. endrin (P)
99. endrin aldehyde (P)
*faeptachlor and metabolites
100. heptachlor (P)
101. heptachlor epoxide (P)
*h.exachlorocyclohexane (all isomers)
102. a-BHC-Alpha (P) (B)
103. b-BHC-Beta (P) (V)
104. r-BHC (lindane)-Gamma (P)
105. g-BHC-Delta (P)
21
-------
Table III-2 (Continued)
LIST OF 129 PRIORITY POLLUTANTS (2)
%>olychlorinated biphenyls (PCB's)
106. PCB-1242 (Arochlor 1242) "(P)
107. PCB-1254 (Arochlor 1254) (P)
108. PGB-1221 (Arochlor 1221) (P)
109. PCB-1232 (Arochlor 1232) (P)
110. PCB-1248 (Arochlor 1248) (P)
111. PCB-1260 (Arochlor 1260) (P)
112. PCB-1016 (Arochlor 1016) (P)
113. *Toxaphene , (P)
114. *Antiraony (Total) (P)
115. *Arsenic (Total)
116. *Asbestos (Fibrous)
117. *Beryllium (Total)
118. *Cadmiura (Total)
119. *Chromium (Total)
120. *Copper (Total)
1 21 . *Cyanide (Total)
122. *Lead (Total)
123. *Mercury (Total)
124. *Niekel (Total)
125. *Seleniura (Total)
126. ^Silver (Total)
127. *Thallium (Total)
128. *Zinc (Total)
129. **2»3»7,8-tetrachlorodiben2o-p~dioxin (TCDD)
*Specific compounds and chemical classes as listed in the
consent degree.
**This compound was specifically listed in the consent degree.
Because of the extreme toxicity (TCDD), EPA recommends that
laboratories not acquire analytical standard for the compound,
***B » analyzed in the base-neutral extraction fraction
¥ =» analyzed in the volatile organic fraction
A « analyzed in the acid extraction fraction
P =• pesticide
22
-------
total. The SIC Manual (5) recommends that, when available, the value
of receipts or revenues be used in assigning industry codes for
transportation-, communication, electric, gas, and sanitary services.
This study was limited to powerplants comprising the steam electric
utility industry and did not include steam electric powerplants in
industrial, commercial or other facilities. Electric generating
facilities other than steam electric, such as combustion gas turbines,
diesel engines, etc., are included to the extent that power generated
by the establishment in question is produced primarily through steam
electric processes. This report covers effluents from both fossil-
fueled and nuclear plants, but excludes the radiological aspects of
effluents.
The Clean Water Act (6) requires EPA to consider several factors in
developing effluent limitation guidelines and standards of performance
for a given industry. These include the total cost of applying a
technology in relation to the effluent reduction benefits realized;
the age of equipment and facilities; the processes employed; the
engineering aspects of applying various types of control techniques;
process changes; nonwater quality environmental impacts (including
energy requirements); and other factors. For steam electric
powerplants, a formal subdivision of the industry on the basis of the
factors mentioned in the Act was inapplicable. The two basic aspects
of the effluents produced by the industry—chemical and thermal—
involve such divergent considerations that a basic distinction between
guidelines for chemical wastes and thermal discharges was determined
to be most: useful , in achieving the objectives pf the Act.
Accordingly, this report covers waste categorization, control and
treatment technology, and recommendations for effluent limitations for
chemical and other non-thermal aspects of waste discharge.
INFORMATION AVAILABILITY, SOURCES AND COLLECTION
Since the publication of the Burns & Roe document in 1974, EPA has
collected additional information on the industry profile, its waste
characteristics, and applicable treatment technologies. In addition,
the NRDC settlement agreement focused attention on the need for
information concerning pollutants in the wastewaters. As a result of
this attention, there have been various studies on the priority
pollutants as to their occurrence in wastewater from the steam
electric power industry.
The data base for effluent limitations and standards for the steam
electric industry was revised on the basis of the following
information sources:
1. A profile of the Steam Electric Power Generating point source
category which lists the name of each plant; its location, age, and
size; its wastewater characteristics; and its pollutant control
technologies.
2. Available data from published and unpublished literature;
demonstration project reports; the steam electric industry; manu-
23
-------
facturers and suppliers of equipment and chemicals used by the
industry; various EPA, federal, state, and local agencies; and
responses to EPA's 308 letter (1976).
3. Engineering plant visits.
5. Result of sampling program at selected plants.
The current effluent guidelines are divided into four subcategories:
generating units, small units, old units, and area runoff. Economic
considerations, rather than chemical discharge characteristics, were
the determining criteria for differentiating the first three
subcategories. Available information indicates that the types of
pollutants discharged by powerplants do not differ significantly among
plants of varying age and size; the chemical waste characteristics are
similar for similar waste sources. Limitations within each
subcategory were therefore specified for each of the in-plant waste
sources. These included: (1) cooling water; (2) ash-bearing streams;
(3) metal cleaning waste; (4) low volume waste; (5) area runoff; and
(6) wet flue gas cleaning blowdown.
Section 308 Data Forms
In order to carry out the Settlement Agreement with NRDC, EPA
collected additional information on the production processes, raw
waste loads, treatment methods, and effluent quality associated with
the steam electric industry. This information was obtained via a data
collection effort pursuant to Section 308 of the Clean Water Act (6).
Section 308 letters and data collection questionnaires were sent to
approximately 900 powerplants in the United States of which a total of
812 responded. The data in the responses were coded and subsequently
keypunched onto data cards and loaded into a computerized data base.
The data base was instrumental in supporting selection of plants for
the sampling visits, as well as a valuable tool in establishing how
many plants employ what technologies relevant to pollution generation
or control.
Data Gathering and Analysis
Initial historical data gathering consisted of visiting the 10 EPA
regional offices and several state environmental departments,
contacting other EPA offices and governmental agencies, and conducting
an extensive literature search. The initial phase of the data
gathering effort occurred during the latter part of 1976 and early
part of 1977. This was followed by the tabulation of each set of data
corresponding to an outfall of a particular plant in terms of
pollutant parameters monitored against the date of analysis. This
information consisted of the list of the various streams being
discharged through this particular outfall and the control or
treatment technology to which these streams are subjected.
24
-------
Screen Sampling Program ,
A screen sampling program was developed to determine the presence of
the 129 priority pollutants in steam electric power industry
effluents. EPA selected eight plants for the screen sampling. These
plants had indicated in their 308'responses that their discharge was
known to contain one or more of the 129 priority pollutants.
Selection was also based upon various plant variables which could
affect plant discharge and effluent composition. The eight plants
selected for the screen sampling program were Plants 4222, 2414, 0631,
1720, 3404, 2512, 3805, and 4836.
The screen sampling procedures followed the Environmental Protection
Agency Screen Sampling Procedure for the Measurement of Priority
Pollutants (7). Grab and continuous composite samples were collected
over 24-hour sampling periods. The continuous 24-hour samples were
collected by automatic samplers and maintained .at 4 C, while the grab
samples were maintained at ambient temperature levels which did not
exceed 4 C. At the end of the 24-hour sampling period, samples were
preserved according to protocol.
Representatives of both EPA and the electric power industry were
present during all sampling. Parallel sampling (two separate samples)
and analysis were conducted. Samples of all waste streams were
analyzed by both EPA-contracted laboratories and power industry-
contracted laboratories.
The EPA-contracted analytical laboratory used analytical procedures
derived from Standard Methods for the Examination of Water. Organics
were analyzed by first extracting the sample into base, neutral, acid,
and volatile fractions and then analyzing each fraction by gas
chromatography with a mass spectrometer detector (GC/MS). Cyanide was
analyzed by steam distillation followed by the standard colorimetric
method. Samples were analyzed for heavy metals by atomic adsorption
spectrophotometry.
Although the screen sampling program, was intended only to determine
the presence or absence of the 129 priority pollutants, the methods of.
analysis did yield numerical concentrations for detected compounds.
Thus, the screening data provided quantified values for detected
priority pollutants.
Verification Sampling Program
A verification program followed screen sampling in order to quantify
further the pollutant loadings from the power generating industry.
This sampling program was used to verify the results of the screen
sampling program for both organic and inorganic analyses.
Verification involved more plants and was a more intensive effort
compared to the screening study. The sixteen plants selected for the
verification sampling program were Plants 2718, 1716,, 3414, 4826,
1742, 1245, 1226, 4251, 3404, 4602, 3920, 3924, 3001, 1741, 5410, and
2121.
25
-------
Representatives of both EPA and the electric power industry were
present during all the verification sampling. Splits of a single
collected sample were used; one half of the original sample went to
the EPA-contracted analytical laboratory and the other half went to
the power industry-contracted laboratory.
Two additional plants were added to the verification data base as data
became available from another contractor using the methods and format
of the sixteen earlier verification studies. These are Plants 5409
and 5604.
Sampling and preservation procedures were similar to those of the
screen sampling program, except that identical, not parallel, samples
were collected for shipment to the EPA and power industry analytical
laboratories.
In total, samples from eighteen plants were analyzed by several
different EPA-contracted laboratories. Analytical procedures included
gas chromatography (GO or gas chromatography-mass spectrometry
(GC/MS) for the organics, and spark source mass spectrometry (SSMS) or
atomic absorption (AA) for most of the inorganics. Mercury was
analyzed by cold-vapor atomic adsorption. Selenium was analyzed by
fluorometry and cyanide by a colorimetric procedure.
Surveillance and Analysis Sampling Program
Additional data were provided through several EPA regional
Surveillance and Analysis (S&A) programs conducted by those regions.
S&A programs involve periodic visits to powerplants by EPA sampling
teams to collect data to determine if the plants are complying with
NPDES permits. During some of these visits arrangements were made for
the sampling of priority pollutants. Eight plants are represented in
this data base; they are Plants 1002, 1003, 4203, 2608, 2603, 2607,
2750, and 5513.
The sampling, preservation, and analytical procedures used by S&A were
similar to those employed in both the screening study and the
verification study. Analytical methods included gas chromatography
mass spectrometry (GC/MS) for organics or ICAP for inorganics.
Waste Characterization Data Base
After evaluation of all the data from the three sampling efforts—
screening, verification, and S&A sampling—the Agency decided that all
three sets of data were useful in establishing the presence and
quantifying the concentration of priority pollutants in discharges
from steam electric powerplants. All three sets of data were stored
in computerized files such that they could be analyzed as a single
data base representing 34 plants.
26
-------
Engineering Visits to Steam Electric Plants
Eight steam electric plants were visited from March to April 1977 to
obtain information on specific plant practices and to develop a
sampling and analysis program to verify collected data, to fill
existing gaps, and to provide additional information. Specific
information gathered included data on raw waste loads, water use/
treatment technology, fuel handling systems, and general plant
descriptions. Additional engineering visits were conducted from
August through September 1979. These visits were to collect data and
water samples from plants with recycling bottom . ash sluice systems.
Fly ash handling methods also were evaluated during these visits.
INDUSTRY DESCRIPTION :
Steam electric powerplants produce electric power. The industry also
transmits and distributes electric energy. The industry is made up
of two basic ownership categories—investor owned and publicly owned
— with the latter further divied into Federal agencies, non-Federal
agencies, and cooperatives. About two-thirds of the 3,400 systems in
the United States perform only the distribution function, but many
perform all three functions: production (generally referred to as
generation), transmission, and distribution. In general, the larger
systems are vertically integrated, while the smaller systems, largely
in the municipal and cooperative categories, rely on purchases to meet
all or part of their requirements. Many of the systems are
interconnected and can, under emergency conditions, obtain power from
other systems.
The industry started around 1880 with the construction of Edison's
steam electric plant in New York City. ' For the next 60 years, growth
was continuous but unspectacular due to the fairly limited despand for
power; since 1940, however, the annual per capita production of
electric energy has grown at a rate of about 6 percent per year and
the total energy consumption by about 7 percent (1). As of 1978,
there were over 2,600 generating plants in the United States. These
systems had a combined generating capacity of 573,800 megawatts (MW)-
and produced 2,295 billion kilowatt hours (MWh) of energy (8). Table
III-3 shows the number of plants, capacity, and annual generation of
the total electric utility industry as well as the steam electric
sector. Non steam electric generation sources include principally
hydroelectric, diesel, and combustion gas turbines. Table II1-4 shows
the number of plants and their capacity for various size categories.
The addition of new plants will alter the 1978 plant and capacity
distribution. By 1985, SPA projects that there will be an additional
161,100 megawatts of capacity added by new plants in the steam
electric sector. In the. period 1986-1990, the addition of 81,300
megawatts is expected. These projections were derived from Temple,
Barker and Sloane, Inc. (TBS) projections of future capacity
requirements (8). Table III-5 shows the present and future capacity
of the industry.
2-7
-------
Table III-3
DISTRIBUTION OF THE STEAM SECTION RELATIVE TO THE
ENTIRE ELECTRIC UTILITY INDUSTRY AS OF 1978* (8, 9)
Capacity Generation Number
(gjLgawatts) (billion kilowatt hours) of Plants
Total Industry 573.8 2,295 >2,600
Steam Sector 453.3 1,951 842
Percent of
Total Industry
Included in
Steam Sector 79% 85% <32%
*The number and capacity of plants in each category is based on
the 1979 DOE Inventory of Powerplants data base. Plants listed
in the DOE Inventory as having a net dependable capacity of
zero were excluded.
28
-------
Table III-4
YEAR-END 1978 DISTRIBUTION OF STEAM ELECTRIC PLANTS
BY SIZE CATEGORY* (8, 9)
0-25 MW 26-100 MW 101-200 MW 201-350 MW 351-500 MW Over 500 MW TotaL
Total MW in
Category
Percent of
Total MW in
Category
Number of
Plants in
Category
Percent of
Total Plants
in Category
1,273 9,466 16,777 24,125
0.3%
98
2.1%
172
11.6% 20.4%
4.0%
115
13.7%
5.3%
87
10.3%
33,282
7.0%
79
9.4%
368,342 453,265
81 .3%
291
34.6%
100.07*
842
100.0%
*The number and capacity of plants in each category is based on the 1979 DOE Inventory of
Powerpiants data base. Plants listed in the DOE Inventory as having a net dependable
capacity of zero were excluded.
-------
Table III-5
PRESENT AND FUTURE CAPACITY OF THE ELECTRIC UTILITY
INDUSTRY (8, 9)
(capacity in gigawatts at year end)
1978 1985 1990 1995
Generating Capacity
Total Industry 573.8 750.3 834.9 1003.8
Steam Sector 453.3 614.4 695.7 855.4
Source: DOE Inventory of Powerplants (1979) and projections
made by Temple,Barker and Sloane, Inc.
30
-------
The U.S. Department of Energy provided information on the number and
capacity of existing steam electric powerplants by size category and
fuel type (9). The fuel mix of future plants was determined from the
fuel types of the announced plant additions, adjusted to account for
some expected fuel shifts,, especially from oil or gas to coal (8).
This infromation is presented in tables III-6 and III-7. A summary of
existing and projected total capacity versus fuel type is presented in
table II1-8. • .
Steam electric powerplants discharge waste heat with once-through
cooling systems, recirculating cooling systems, or a combination of
both. The type of cooling system is important in determining the
values of a plant's effluent discharge and therefore the cost of
treating the discharge. Plants with once-through cooling water
systems discharge the cooling water after only one or two passes
through the plant. . The waste heat is dissipated to a receiving body
of water. Plants with recirculating cooling water systems in most
cases use cooling towers, either forced draft or natural draft, and
recirculate the water through the plant. A blowdown stream is
typically discharged from a recirculating system to control the
buildup of dissolved solids. The cooling mechanism, evaporation,
results in the discharge of waste heat to the atmosphere and
evaporation of water concentrates dissolved solids. Of the existing
plants approximately 65 percent or 547 plants use once through cooling
and 35 percent or 295 plants use recirculating cooling water systems.
The distribution of plants by age and size category appears in table
III-9. Plants built since 1971 represent about 40 percent of steam
electric capacity. Plants built before 1961 represent only about 26
precent of the existing capacity.
PROCESS DESCRIPTION
The "production" of electrical energy always involves the conversion
of some other form of energy. The three most important sources of
energy which are converted to electric energy are the gravitational
potential energy of water, the atomic energy of nuclear fuels, and the
chemical energy of fossil fuels. The use of water power involves the
transformation of one form of mechanical energy into another prior to
conversion to electrical energy and can be accomplished at greater
than 90 percent of theoretical efficiency. Therefore, hydroelectric
power generation produces only a minimal amount of waste heat through
conversion inefficiencies. Current uses of fossil fuels, on the other
hand, are based on a combustion process, followed by steam generation
to convert the heat first into mechanical energy and then to convert
the mechanical energy into electrical energy. Nuclear processes in
general also depend on the conversion of thermal energy (heat) to
mechanical energy via a steam cycle (1).
Hydroelectric Power
Hydroelectric power uses the energy of falling water to produce
electric power. Although the facility construction and development
31
-------
Table III-6
NUMBER OF EXISTING STEAM-ELECTRIG POWERPLANTS
BY FUEL TYPE AND SIZE (8, 9)
(number of plants)
u>
fsi
Total
Plant Size Categories
Fuel Type
Existing (1979)
Coal
Oil/Gas
Nuclear
Other
0-25 MW
35
48
0
15
26-
100 MW
63
102
2
5
101-
200 MW
36
76
2
1
201-
350 MW
38
48
0
1
351-
500 MW
35
44
0
0
More Than
500 MW
145
111
34
1
Total
352
429
38
23
98
172
115
87
79
291
842
Source; DOE Inventory ofPowerplants (1979).
-------
Table III-7
CAPACITY OF EXISTING AND NEW STEAM- ELECTRIC POWERPLANTS BY FUEL TYPE AND SIZE (8, 9)
1978-1995
(gigawatts)
_ Plant Size Categories
__. __ __
_
__. T_T_ _j_ 35^ More Than
Fuel Type 0-25 MW 100 MW 200 MW 350 MH 500 MM 500 MM Total
Existing (1979)
Coal
Oil/Gas
Nuclear
Other" " ' _____ _ ___ _ ___ __
Total 1.27 9.47 16.78 24TT2 33.29 368.33 453.37
Additions (1978-1985)
....... ..... ' '
Coal 79.20
Oil/Gas 19.80
Nuclear 85.40
.46
.67
0
.14
3.46
5.69
.16
.16
5.59
10.71
.35
.13
10.47
13.33
0
.32
14.77
18.52
0
0
192.61
121 .16
53.31
1.25
227.37
170.07
53.83
2.10
Total 184.40
Additions (1986-1995)
Coal 187.30
Oil/Gas .20
Nuclear 142.10
Total 329.60
Total Additions (1978-1995) 514.00
Source: DOE Inventory of Powerplants.
-------
Table III-8
EXISTING AND PROJECTED DISTRIBUTION OF STEAM ELECTRIC
.POWERPLAOTS BY FUEL TYPE (8, 9)
(capacity in gigawatts)
1978a 1985b . 1990b 1995b
Coal Capacity 227.4 301.8 365.1 473.9
Number of Plants 352 467 565 734
Oil/Gas Capacity 170.1 173.5 157.4 100.4
Number of Plants 429 438 397 253
Nuclear Capacity 53.8 139.0 173.1 , 281.0
Number of Plants 38 98 122 198
Sources:
aDOE, Inventory of Powerpiants, (1979).
^Electrical World; September 15, 1979; and projections by
Temple,Barker,and Sloane, Inc.
34
-------
Table III-9
DISTRIBUTION OF STEAM-ELECTRIC CAPACITY BY PLANT SIZE AND IN-SERVICE YEAR (9)
Plant Size Category
Plant Age
Category
Pre-1960 MW
Percent of
Age Category
1961-1970 MW
Percent of
Age Category
Post-1970 MW
Percent of
Age Category
Total MW
Percent of
Age Category
0-25
1,154
1
344
.3
20
.01
1,518
.3
26-100
6,656
5.6
2,157
1.6
1,135
.6
9,948
2
101-200
12,926
10.8
4,052
3.0
1,543
.8
18,521
4
201-350
17,362
14.5
6,570
4.8
3,942
2
27,874
6
351-500
16,749
14
9,630
7.1
7,539
3.8
33,918
7
>500
64,968
54
112,844
83
184,502
93
362,314
80
Total
119,815
100
135,597
100
198,681
100
454,093
100
Percent
of Total
Capacity
26
30
44
100
, • . .
Source: DOE Inventory of Powerplants, 1979.
-------
costs are high, the fuel itself is not an operational cost.
Unfortunately, the availability of hydroelectric power is limited to
locations where' nature has created the opportunity of providing both
water and elevation differences to make the energy extractable. The
total hydroelectric capacity installed at the end of 1975 amounted to
about 5 percent of the total installed United States generating
capacity. This share of power is projected to decline to less than
0.1 percent by 1983 (8), primarily because the number of sites
available for development have already been developed and the
remaining sites are either too costly or too far from urban centers
(10).
Another form of hydroelectric power is produced by means of pumped
storage projects. The process involves pumping water into an elevated
reservoir during off-peak load hours, and then generating electricity
at peak load periods by conventional hydroelectric means. Although
not as efficient as once-through hydroelectric power facilities,
pumped storage projects are favorable for the peak load periods when
power demands are very high and additional power generation capacity
is needed to supplement the normal load generators.
In general, hydroelectric power represents a viable alternative to
fossil-fueled or nuclear steam cycle generation where geographic,
environmental, and economic conditions are favorable (1).
Steam Electric Powerplants
Steam electric powerplants are the production facilities of the
electric power industry. The process to produce electricity can be
divided into four stages. In the first operation, fossil fuel (coal,
oil, or natural gas) is burned in a boiler furnace. The evolving heat
is used to produce pressurized and superheated steam. This steam is
conveyed to the second stage—-the turbine— where it gives energy to
rotating blades and, in the process, loses pressure and increases in
volume. The rotating blades of the turbine act to drive an electric
generator or alternator to convert the imparted mechanical energy into
electrical energy. The steam leaving the turbine enters the third
stage—the condenser—where it is condensed to water. The liberated
heat is transferred to a cooling medium which is normally water.
Finally, the condensed steam is re.introduced into the boiler by a pump
to complete the cycle.
Historically, powerplants were categorized in accordance with the type
of fuel they burned. Recently, however, because of the energy crisis
and other cost factors, powerplants have modified their equipment to
enable them to use more than one fuel. Based on 308 data, 78 percent
of the steam electric powerplants have the capability of using two or
more fossil fuels, which indicates that the majority, of all steam
electric plants have the capability to burn more than one type of
fossil fuel.
Figure III-l shows a simplified flow diagram of a typical coal-fired
powerplant. The figure depicts features which are common to all
36
-------
- „ B1 r~' ' ' - . --
, WiHtir Plow 1 • .,
— t Air EiuiattjUma - i
-*x»^a- cool I Collection J
j t
L.- .. .. ..L L .... .
i
• * toiiaeiisate
I
I Boiler Ganawtoc^j f
FueJ- Stem _I Steam fn f
uttr . . . *" Tceutwent *~ Ueiwruting -\^ \^
, ^^-^.
i ' w Blowdoun '
Eluudown
1 Oiice-Tliiroiigli Cooling j ,
.;•-»-- J - r - - . j
1 I
1 ' BoCtomABli Boiler Tube Cleanina,
. j ' Handling Fireside and Air
Coal £ 1
*— - • • i ' • •
. ' -:!1__ _ _'!___„ "'._
—.
-^j
:nse
'-~s
\
)
Sanitary uaace laliuracory
ti unmpling tiaatca, intake
caullng uat^r ayutcma con-
struction, Activity
f
B^iving
t w
Figure III-l
TYPICAL COAL-FIRED STEAM ELECTRIC PLANT
-------
powerplants as well as features which are unique to coal-fired
facilities. Features unique to coal-fired plants include coal storage
and preparation (transport, beneficiation, pulverization, drying),
coal-fired boiler, ash handling and disposal system,, and flue gas
cleaning and desulfurization. A brief description of tttlse features
and their environmental results is presented in subsequent sections of
this document. EPA anticipates that future designs will emphasize
recovery and reuse of resources, in particular recycle of water and
use of fly ash as a resource.
Combustion Gas Turbines and Diesel Engines
Combustion gas turbines and diesel engines are devices for converting
the chemical energy of fuels into mechanical energy by using the
Brayton and Diesel thermal cycles as opposed to the Rankine cycle used
with steam. In a combustion gas turbine, fuel is injected into
compressed air in a combustion chamber. The fuel ignites, generating
heat and combustion gases, and the gas mixture expands to drive a
turbine, which is usually located on the same axle as the compressor.
Various heat recovery and staged compression and combustion schemes
are in use to increase overall efficiency. Aircraft jet engines have
been used to drive turbines which, in turn, are connected to electric
generators. In such units, the entire jet engine may be removed for
maintenance and a spare installed with a minimum of outage time.
Combustion gas turbines require little or no cooling water and
therefore produce no significant effluent. Diesel engines, which can
be operated at partial or full loads, are capable of being started in
a very short time, so they are ideally suited for peaking use. Many
large steam electric plants contain diesel generators for emergency
shutdown and startup power (1). In 1975, gas turbine and diesel-
powered electric generation plants represented 6.8 percent of the
total United States generating capacity. By 1983 the number of gas
turbine and diesel-powered electrical generation plants is projected
to decline to less than 0.1 percent of the total United States
electric generating capacity (2).
Nuclear Powerplants
Nuclear powerplants utilize a cycle similar to that used in fossil-
fueled powerplants except that the source of heat is atomic
interactions rather than combustion of fossil fuel. Water services as
both moderator and coolant as it passes through the nuclear reactor
core. In a pressurized water reactor, the heated water then passes
through a separate heat exchanger where steam is produced on the
secondary side. This steam, which contains no radioactive materials,
drives the turbines. In a boiling water reactor, steam is generated
directly in the reactor core and is then piped directly to the
turbine. This arrangement produces some radioactivity in the steam
and therefore requires some shielding of the turbine and condenser.
Long term fuel performance and thermal efficiencies are similar for
the two types of nuclear systems (1).
38
-------
Alternative Processes Under Active Development
Future Nuclear Types
At the present time almost all of the nuclear power-plants in,.operation
in the United States are of the boiling water reactor (BWR) or
pressurized water reactor (PWR) type. Some technical aspects of these
types of reactors limit their thermal efficiency to about 30 percent.
There are potential problems in the area of fuel availability if the
entire future nuclear capacity is to be met with these types of
reactors. In order to overcome these problems, a number of other
types of nuclear reactors are in various stages of development. The
objective of developing these reactors is two fold: to improve
overall efficiency by being able to produce steam under temperature
and pressure, conditions similar to those being achieved in fossil fuel
plants and to assure an adequate supply of nuclear fuel at a minimum
cost. Included in this group are the high temperature, gas-cooled
reactor CHTGR), the seed blanket light water breeder reactor (LWBR),
the liquid-metal fast breeder reactor (LMFBR), and the gas-cooled fast
breeder reactor (GCFBR). All of these utilize a steam cycle as the
last stage before generation of electric energy. Both the HTGR and
the LMFBR have advanced sufficiently to be considered as potentially
viable, alternate processes.
The HTGR is a graphite-moderated reactor which uses helium as a
primary coolant. The helium is heated to about 750 degrees Centigrade
(1,400 degrees Fahrenheit) and then gives up its heat to a steam cycle
which operates at a maximum temperature of about 550 degrees
centigrade. (1,000 degrees Fahrenheit). As a result, the HTGR can be
expected to produce electric energy at an overall thermal efficiency
of about 40 percent. The thermal effects of its discharges should be
.similar to those of an equivalent capacity fossil-fueled plant. Its
chemical wastes will be provided with essentially similar treatment
systems which are presently being provided for BWR and PWR plants.
The LMFBR will have a primary and secondary loop cooled with sodium
and a tertiary power producing loop utilizing a conventional steam
system. Present estimates are that the LMFBR will operate at an
overall thermal efficiency of about 36 percent, although higher
efficiencies are deemed to be ultimately possible. The circulating
water thermal discharges of, the LMFBR will initially be about halfway
between those of the best fossil-fueled plants and the current
generation of nuclear plants. Chemical wastes will be similar to
those of current nuclear plants (1).
Coal Gasification
Coal gasification involves the production of fuel gas by the reaction
of the carbon in the coal with steam and oxygen. The processes of
this energy technology are divided into two groups depending upon the
heating value of the product gas. Low Btu gasification utilizes air
as the oxygen source and produces a CO and H2 rich gas with a heating
value of 150 - 450 Btu/scf. High Btu gasification utilizes pure
39
-------
oxygen in the gasification process and produces a fuel gas of pipeline
quality with a heating value of approximately 1,000 Btu/scf. The main
difference between high and low Btu processing is the inclusion of
shift conversion and methanation processes in the processing sequence
for high Btu gasification. &*.
The Federal Government and a number of private organizations are
supporting research and development of coal gasification complexes.
Estimates indicate that low Btu gasification of coal can be
accomplished for less than twice the current natural gas price paid by
electric utilities. As natural gas and fuel oil become increasingly
short in supply, gasification of coal could well turn into a factor in
steam electric power generation.
Combined Cycle Powerplants
Combined cycle power systems combine gas turbine and steam turbine
cycles to increase thermal efficiencies of power generation. The hot
exhaust gases from a gas turbine are used to generate steam in an
unfired boiler. The steam generated is used to drive a conventional
steam turbine. Combined cycle systems might consist of a number of
gas turbines exhausted into a single steam turbine with its own
electric generating capacity. Another combined cycle concept is a
pressurized bed system. The concept is to burn coal in a fluidized
bed environment of dolomite at 10 atmospheres of pressure. Steam is
produced in the conventional manner of using boiler heat for the steam
cycle but cleaned combustion gases are also used to produce
electricity by use of a gas turbine. Waste heat is used to economize
the cycle through preheating of boiler feed water.
FUTURE GENERATING SYSTEMS
Natural Energy Sources
Geothermal Energy. Geothermal energy is the natural heat contained in
the crust of the earth. While ubiquitous throughout the earth's
crust, only in a few geological formations is it sufficiently
concentrated and near enough to the surface to make its recovery
economically viable. Geothermal energy involves six major resource
types of which two are currently capable of being utilized for the
generation of electricity. Vapor-dominated reservoirs, such as those
utilized at The Geysers, California, obtain steam directly from wells
drilled into the geothermal reservoirs. The steam is then used to
drive a steam turbine. Liquid-dominated reservoirs contain geothermal
fluids consisting of hot water and steam. The geothermal fluids must
first be flashed to steam or used to evaporate some other types of
working fluid, which is then used to drive a steam turbine.
The advantage of geothermal power generation is that the energy source
is essentially free after the initial exploration, drilling, and
facility costs are paid off. The disadvantages of geothermal power
generation are that the costs of facility siting and construction are
40
-------
high, and geothermal fluids must be cleaned prior to use and disposed
of by reinjection tp the subsurface geothermal reservoir.
Solar Energy. The conversion of solar energy to electricity at a
large scale via a steam cycle involves the use of a. large .array of
reflective focusing collectors which concentrate the.solar radiation
on a heat collector which heats water to steam. The steam is used to
drive a steam turbine to produce electricity. The systems currently
in use are developmental, and it is projected that, in the future, as
fossil fuels become increasingly short in supply and high in cost,
solar systems will be developed in areas which are geographically
suited to maximum solar collection and conversion.
Biomass Conversion. This involves the production of photosynthetic
materials {wood, sugar cane, and other similar high Btu content crops)
for use as a fuel. The photosynthetic materials can be directly
combusted in coal-fed type boilers or converted into low Btu gas by
gasification of the biomass. The technology behind biomass production
and utilization closely resembles agricultural techniques and
techniques evolved from the handling of coal. As a result, the
utilization of biomass materials as a heat source for steam electric
generation will increase as demands are placed on the coal industry to
provide cleaner fuel at low prices.
Other Natural Energy Sources., Other major energy conversion processes
(ocean thermal gradiant to electricity, wind energy to electricity,
photovoltaics, and solar heating and cooling of buildings and water)
involve mechanical conversion or the transfer of heat without the
production of steam for use as a working fluid.
Maqnetohydrodynami cs
Magnetohydrodynamics (MHD) power generation consists of passing a hot
ionized gas or liquid metal through a magnetic field to generate
direct current. The concept has been known for many years, although
specific research directed towards the development of viable systems
for generating significant quantities of electric energy has only been
in progress for the past 10 years. Magne.tohydrodynamics have
particular potential as a "topping" unit used in conjunction with a
conventional steam turbine. Exhaust from a MHD generator is hot
enough to be utilized in a waste heat boiler resulting in an overall
system efficiency of 50 to 60 percent. The problem associated with
MHD is the development of materials which can withstand the
temperature generated. Despite its high efficiency, development of
MHD to a commercial operation is not expected to occur within the next
several years in the United States (1).
Electroqasdynamics
Electrogasdynamics (EGD) produces power by passing an electrically
charged gas through an electric field. The process converts the
kinetic energy of the moving gas to high voltage direct current
electricity. The promise of EGD is similar to the promise of MHD.
-------
Units would be smaller, would have a minimum of moving parts, would
not be limited by thermal cycle efficiencies, and would not require
cooling water. The system could also be adapted to any source of fuel
or energy including coal, gas, oil or nuclear reactors.
Unfortunately, the .problems of developing commercially practical units
are also similar to those associated with MHD (1).
Fuel Cells
Fuel cells are electrochemical devices, similar to storage batteries,
in which the chemical energy of a fuel such as hydrogen is converted
continuously into low voltage electric current. The prospect of fuel
cells is for use in residential and commercial services. However, the
fuel cell is not expected to replace a significant portion of the
central powerplant generator facilities within the next several years
due to expense of manufacturing and the significant quantity of
electric power needed to produce the cells.
42
-------
SECTION IV
INDUSTRY CATEGORIZATION
The 1974 Development Document (1) presented the framework and
rationale for the recommended industry categorization which was
subsequently used in the development of chemical-type waste effluent
limitations under best practicable control technology, best available
technology economically achievable, and standards of performance for
new sources. Factors which were considered in the development of the
industry categorization included analysis of the processes employed;
raw materials used; the number and size of generating facilities;
their age, and site characteristics; mode of operation; wastewater
characteristics; pollutant parameters; control and treatment
technology; and cost, energy and non-water quality aspects. As a
result, it was recommended that the industry be categorized according
to the origin of individual waste sources, including: condenser
cooling system; water treatment; boiler or PWR steam generator;
maintenance cleaning; ash handling; drainage; air pollution control
devices; and miscellaneous waste streams.
Since the issuance of the 1974 Development Document (1), additional
information has been collected through questionnaire surveys, plant
visits, and sampling and analysis programs for priority pollutants.
The steam electric power generating point source category has been
reevaluated in - light of this new information to determine whether
categorization and subcategorization would be required for the
preparation of effluent guidelines and standards for the industry.
The reevaluation consisted of: . (1) the statistical analysis of 308
questionnaire data to assess the influence of age, size (installed
generating capacity), fuel type, and geographic location on wastewater
flow; and (2) engineering technical analysis to assess the influence
of these and other variables on wastewater pollutant loading and the
need for subcategorization.
On the basis of the reevaluation studies, EPA concluded that the
existing categorization approach (by chemical waste stream origin) was
adequate, but that a new format would be an improvement. The
recommended categorization for the steam electric power generating
point source category includes:
1. Once-Through Cooling Water
2. Recirculating Cooling System Slowdown
3. Fly Ash Transport Discharge
4. Bottom Ash Transport Discharge
5. Metal Cleaning Wastes
- Air preheater wash
- Fireside wash
4-3
-------
- Boiler tube cleaning
- Cleaning rinses
6. Low Volume Wastes
= ' ' ' '•>*-
- Clarifier blowdown
- Makeup water filter backwash
- Lime softener blowdown
- Ion exchange softener regeneration
- Demineralizer regeneration
Powdered resin demineralizer back flush
- Reverse osmosis brine
- Boiler blowdown
- Evaporator blowdown
- Laboratory drains
- Floor drains
- Sanitary wastes
- Diesel engine cooling system discharge
7. Ash Pile, Chemical Handling and Construction Area Runoff
8. Coal Pile
9. Wet Flue Gas Cleaning Blowdown
The following subsections of this section describe the statistical
analysis and engineering technical analysis performed as a part of the
categorization reevaluation.
STATISTICAL ANALYSIS
Flow data from the steam electric 308 questionnaire data base were
obtained for once-through cooling water, recirculating cooling system
blowdown, ash transport discharge, and low volume waste discharges.
Flow values were normalized by installed plant generating capacity and
expressed in gallons per day per megawatt.
Four independent variables were studied to determine their effect on
waste flow discharge. They were: principal fuel type (oil, coal,
gas); EPA region; generating capacity; and age. The effect of these
four variables on normalized waste flow discharge was tested using
analysis of covariance. Results of the analysis indicated those
independent variables which have a statistically significant effect on
waste flow discharge and therefore warranted further consideration as
a basis for subcategorization. Table IV-1 presents the independent
variables which were found statistically to have an influence on
normalized waste flow discharges. In general, fuel type was found to
have the greatest influence on normalized discharge flow. This was
expected because water requirements for ash transport and other uses
normally vary among oil, coal, and gas-fired plants.
Although some statistically significant influences were found, their
practical significance requires further, examination. Table IV-2 lists
44
-------
Table IV-1
^VARIABLES FOUND TO HAVE A STATISTICALLY
SIGNIFICANT INFLUENCE ON NOBMALIZED FLOW DISCHARGES
Independent Variable
Normalized Discharge Source Fuel Type - Capacity EPA Region Age
Once Through Cooling Water x
lecirculating Cooling Water
Slowdown x
Ash Transport Discharge x
Low Volume Waste Discharge x x
45
-------
Table I?-2
PERCENT OF THE VARIATION IN NORMALIZED 'DISCHARGE
FLOWS THAT IS EXPLAINED:BY THE INDEPENDENT VARIABLES
Percent of the Variation
in Normalized Discharge
Explained by the Inde-
Discharge Source pendent Variables
Once Through Cooling 9.6
Recirculating Cooling Water Slowdown 16.5
Ash Transport Discharge 18.6
Low Volume Waste Discharge 18.3
46
-------
the percent of the variation in normalized flow discharge which is
explained by the four independent variables investigated. in
statistical terminology, these percentages are the square of the
multiple correlation coefficient (R&), expressed as a percent. The
relatively ^ow R2 values indicate that although some of the
independent variables were shown to statistically influence discharge:,
their importance is largely overshadowed by other influences. Less
than 20 percent of the variation in normalized ash transport discharge
was explained by the influences of fuel type, plant capacity, EPA
region and plant age. The Agency therefore concluded that there was
no strong statistical basis for establishing discharge source
subcategories by fuel type, plant capacity, EPA region, or plant age.
ENGINEERING TECHNICAL ANALYSIS
The objective in developing any System of industry subcategorization
is to provide logical groupings of discharges based on those factors
which affect the waste loading from the plant. The effect on. the
waste loading must be of sufficient magnitude to warrant imposition of
a different treatment technology or to affect radically the
performance of an existing technology.
The following characteristics of steam electric power generating
plants were considered in establishing the basis for industry
subcategorization:
1. Age
2. Size (Installed Generating Capacity)
3. Fuel Type
4. Intake Water Quality
5. Geography
6. Source of Raw Waste - = •
These factors were selected as having the greatest potential effect on
powerplant waste loading.
Previous analyses (1) have shown that older plants (defined by the
year the oldest currently operating boiler was placed in service) tend
to be smaller, tend to have urbanized locations, and are somewhat more
likely to discharge plant wastewaters to publicly owned treatment
works (POTW's). Of these factors only the size of the facilities is
likely to impact wastewater quality or loading. Smaller plants do
have smaller discharges compared to large plants but the quality of
the discharge is not appreciably different.
47
-------
The biggest influence of plant age is on the economics of power
generation. Older plants are less efficient than new ones and the
cost of producing electricity is generally higher. It is therefore
logical that capital investment in, as well as operating expenses of,
pollution control equipment in older facilities can* cause more
economic hardship as compared to newer more efficient facilities. The
economic issues are addressed in the economic evaluation being
prepared as a companion document to this one.
The influence of age was judged not to be of a nature to warrant
future subcategorization beyond the division by wastewstreams as
presented earlier.
Size
As noted above station size (commonly expressed as installed
generating capacity in megawatts) is an important factor influencing
the volume of effluent flow. Discharge flows of cooling water, boiler
feed water, ash handling water, and other waste streams.all increase
with increasing installed capacity. In general, small stations
produce about the same quality of wastewater as compared to larger
stations.
Fuel Type
The type of fuel (coal, oil, gas, nuclear) used to fire powerplant
boilers most directly influences the number of powerplant waste
streams. The influence comes principally from the effect of fuel on
the ash transport waste stream. Stations using heavy or residual oils
such as no. 6 fuel oil generate fly ash in large quantities and may
generate some bottom ash. This ash must be handled either dry or wet.
Wet handling produces a waste stream. Stations which use wet removal
methods have an ash sluice water stream that typically contains heavy
metals including priority pollutants.. Stations which burn coal create
both fly ash and bottom ash. As in the case of oil ash, both types of
coal ash can be removed either by wet or by dry methods. Those power
stations using wet ash removal methods have an ash sluice water stream
containing inorganic toxic pollutants such as arsenic, selenium,
copper/ etc.
Since fuel can affect both the presence and concentration of
pollutants, fuel type does have a strong influence on waste loading
and could serve as a potential basis for subcategorization. The
existing categorization by waste stream source, however, does include
the effect of fuel type by establishing limitations for ash transport
water and further subcategorization of those waste streams by fuel
type is not necessary.
Intake Water Quality
Quality of the intake water has both a direct and an indirect effect
on the waste loading and discharge flow of a power station. The
direct effect is that pollutants coming into the plant tend to be
48
-------
eventually discharged by the plant. The indirect effects are mote
complex, High concentrations of dissolved solids in. the intake water
can require more frequent regeneration of, boiler water treatment
systems. High dissolved solids content may also limit the amount of
recycle of cooling water from the cooling towers, thus increasing the
flow of cooling tower blowdown. High organic loadings in the raw
water"" intake require larger doses of chlorine or other chemicals for
cooling water treatment. Water quality is normally divided into three
types: fresh, brackish, and salt, depending on the concentration of
dissolved solids. The different types of water are .believed to react
differently with chlorine and other biocidal agents to produce
different types and different concentrations of reaction products.
Intake water quality can affect both the flow and pollutant
concentration in water discharges. However, its influence on cooling
water flows is mostly dependent on the type of cooling used by the
station. The influence of intake water quality is accounted for in
the present categorization and was rejected as a basis for
subcategorization.
Geographic Location
Geographic location can have an influence on power station waste
concentrations and flows primarily through the affect of intake water
availability and quality. The effect of intake water quality is
described above. Other geographical oriented considerations have
small to no effect on wastewater flow or quality.
Waste: Stream Source
Steam electric powerplant waste stream source has the strongest
influence on the presence and concentration of various pollutants as
well as on flow, - Waste stream source effects all aspects of waste
loading. Power stations commonly have several wastewater sources, but
rarely are all possible sources present at any single station. All of
the sources present fit into one of the general categories.
Categorization by waste source provides the best mechanism for
evaluating and controlling waste loads. It was concluded that current
categorization by waste stream source should be retained.
49
-------
50
-------
SECTION V
WASTE CHARACTERIZATION
INTRODUCTION
This study addresses only the chemical aspects of powerplant
wastewater discharge. A number of different operations by steam
electric powerplants discharge chemical wastes. Many wastes are
discharged more or less continuously as ' long as the plant is
operating. These include wastewaters from the following sources:
cooling water systems, ash handling systems, wet-scrubber air
pollution control systems, and boiler blowdown. Some wastes are
produced at regular intervals, as in water treatment operations which
include a .cleaning or regenerative step as part of their cycle (ion
exchange, filtration, clarification, evaporation). Other wastes are
also produced intermittently but are generally associated with either
the shutdown or startup of a boiler or generating unit such as during
boiler cleaning (water side), boiler cleaning (fire side), air
preheater cleaning, cooling tower basin cleaning, and cleaning of
miscellaneous small equipment. Additional wastes exist which are
essentially unrelated to production. These depend on meteorological
or' other factors. Rainfall runoff, for example, causes drainage from
coal piles, ash piles, floor and yard drains, and from construction
activity. A diagram indicating potential sources * of wastewaters
containing chemical pollutants in a fossil fueled steam electric
powerplant is shown in figure V-l.
DATA COLLECTION ' -
Data on waste stream characteristics presented in this section were
accumulated from the following sources:
1. The 1974 Development document for the Steam Electric Industry (1);
2. Literature data available since 1974 supplied by various sources,
including the steam electric industry;
3. Individual plant information available from approximately 800
steam electric plants responding to an EPA data collection effort
(under authority of section 308 of the FWPCA);
4. Data from monthly monitoring reporting forms, EPA regional
offices, state agencies, and other Federal agencies;
5. Results of screen sampling and analysis of steam electric
facilities;
6. Results of verification sampling and analysis of steam electric
facilities; and ' ]
7. Miscellaneous data sources.
51
-------
CIKHICAll
MU tMfl*
iMHTomr VASTH,
UlOMfOMf C SAMfllKC
WASTCS, INfMt SCftCCH
IMSUAIM, CICStt
COOtlKC UAt£K SmtKS
CONSIRUCf IOH ACflVlflf
HI5C. WAJH-
WAICN S1KMIS
t"giotpai«r~|»
1.CCEHII
, itquii riow
-»- __ _ US ( StlAH flOW
ll,l« :f CHtHICAU
-. OMIOHAl ftW
4 UMfi IOWCC
Figure V-l
SOURCES OF WASTEWATER IN A FOSSIL-FUELED
STEAM ELECTRIC POWER PLANT (1)
52
-------
Most of the historical data available cover conventional and non-
conventional non-toxic pollutants such as total residual chlorine,
free available chlorine, temperature, non-priority metals, oil and
grease, total suspended solids (TSS), and pH. Data covering the
organic priority pollutants were practically nonexistent. A two fold
sampling program was conducted to fill the data void. The initial
"screening" phase served to identify the presence of pollutants and
the "verification" phase to quantify them. Five analytical
laboratories were involved in the sampling program. All the
laboratories used gas chromotography with a mass spectrometer detector
(GC/MS) in analyzing for the organics (with one exception) and atomic
adsorption for the metals (with two exceptions). One laboratory used
a GC with a Hall detector for organic analyses. Two laboratories used
the Inductively Coupled Argon Plasma Atomic-Emission Spectroscopy
Method (ICAP) for metal analyses. The sampling protocol outlined in
the document entitled, "Sampling and Analysis Procedures for Screening
of Industrial Effluents for Priority Pollutants—April 1977 (2), was
used with some minor revisions. The revisions are described in the
subsections on each waste stream.
Methylene chloride and phthalates were detected in almost all samples.
The potential sources of contamination for these pollutants include
sampling and analytical equipment (phthalates are used as plasticizer
in tubing), and reagent used to clean and prepare sample bottles
(methylene chloride). For these reasons, phthalates and methylene
chloride are excluded from consideration as pollutants from powerplant
operation.
Screen Sampling Efforts
Eight plants were chosen for example under the screen sampling phase.
These plants were representative of the pollutant sources encountered
in the industry; the selection of plants was based on plant variables
known to affect effluent composition. The selection criteria
included: fuel type, plant size, cooling type, and feed water
quality. The characteristics of these eight plants are summarized in
table V-l.
Verification Sampling Efforts
The verification sampling phase was developed' to quantify pollutant
loadings from the power-generating industry. Plants were chosen for
this phase after consultation with industry representatives and
computer scans of the 308 data base. The rationale for plant
selection was based on chemical discharge waste characteristics. This
phase focused primarily on the following streams: once-through
cooling water, cooling tOwer blowdown, and ash handling waters.
Although this sampling effort emphasized these major waste sources,
other waste streams were also sampled.
Pollutants discharged from once-through cooling water can be
attributed to corrosion of construction materials, and to the reaction
of elemental chlorine as hydrochlorite with organics in the intake
53
-------
Table V-1
CHAEACTERISTICS OF PLANTS SAMPLED IN THE SCREEN SAMPLING PHASE
OF THE SAMPLING PROGRAM
Plant
4222
0631
2414
1720
3805
3404
2512
4836
Capacity
(MW)
1641.7
169
1329
1107
660
1120
495
Fuel Type
Bituminous
Coal
Oil/Gas
Bituminous
Coal
Bituminous
Coal
Lignite
Coal
475.6 Coal/Oil
Oil
Gas
Fly Ash
Collection
ESP
Cyclones
Units 1,2:
ESP
Unit 3:
Scrubber
ESP
ESP
Fly Ash Hand1ing
Once-Through
Sluicing
Dry Handling
Dry
Units 1,2:
Handling
Unit 3: Partial
Recirculation
Sluice System
Once-Through
Sluicing
Partical Reeir-
culating Sluice
System
Reinjection of
Fly Ash Into
Boilers
Partial Recir-
culation of Fly
Ash Sluice
Cooling Water System/
Type of Water
Cooling Towers/Fresh
Water
Cooling Towers/Fresh
Water
Units 1»2; Once-
Through/Fresh Water
Unit 3: Cooling
Tower/Fresh Water
Once-Through/Fresh
Water
Once-Through/Saline
Water
Units 1,2: Cooling
Towers/Saline Water
Unit 3; Once-Through
/Saline Water
i>
3
Once-Through/Saline
Water
Cooling Towers/Fresh
Water
-------
water. Primary emphasis for cooling waters was placed on organics.
Plants sampled during the verification program were selected on the
basis of intake water quality. Powerplants with fresh water intake,
brackish water intake, and saline water intake were selected because
reaction kinetics for chlorinated organics formation are known to
differ with the nature of the water source.
Pollutants in cooling tower blowdown may be the result of chlo-
rination, chemical additives, and corrosion and erosion of the piping,
condenser, and cooling tower materials. The Agency therefore,
considered materials of construction (in particular cooling tower
fills) in plant selection. Plants using the three most prevalent
types of cooling tower fill were sampled. Plants with fresh,
brackish, and saline water intakes were selected for chlorinated
organics sampling. Since most of the powerplants were chlorinating on
an intermittent basis, cooling tower and once-through cooling
effluents were sampled only during periods of chlorination.
.Ash handling streams contain dissolved material from J:he ash
particles. The. chemical nature of the ash material is a function of
fuel composition. The four basic fuels considered were: coal, oil,
natural gas, and nuclear. Natural gas-fired and nuclear-fired plants
do not generate ash. Responses from the 308 letters indicate that few
oil-fired plants have wet ash-sluicing systems. Only one plant with
oil ash handling waters was sampled. As a result, the ash transport
waters from coal-fired powerplants were the primary focus. Four
factors were determined to have the greatest impact on this stream:
(1) sulfur content; (2) type of coal (bituminous, lignite, etc.); (3)
origin of coal; and (4) type of boiler. Plants were selected under
these criteria. Most coal-fired facilities have ash ponds or other
means of treatment for total suspended solid removal. Samples were
taken from the ash pond effluent. Table V-2 lists the powerplants
sampled during the verification phase of the sampling program.
Information regarding plant fuel type, installed generating capacity,
ash handling systems, and cooling system type are provided in this
table.
Sampling Program Results .' • • •
The results of the screening and verification sampling programs are
discussed by specific waste stream in the following subsections:
1. Cooling Water :
- once-through
recirculating
2. Ash Handling
- combined ash ponds
- separate fly ash and bottpm ash ponds
3. Boiler Blowdown
5-5
-------
Table V-2
CHARACTERISTICS OP PLANTS SAMPLED IN THE VERIFICATION PHASE
in
Plant
No.
2718
1716
4826
1742
1226
Capacity
MW
136.9
648.5
826.3
22
117
I I /
1,229
ooc
OJ J
Fly Ash
Fuel Type Handling System
Lignite Coal Dry
Bituminous Dry
Coal /Gas
n-i i
Gas N/A
Bituminous Dry
Coal /Oil
Hi T /facj
Ul-i./ Ijctb _____
Bituminous Wet Once-Through
Coal/Oil/Gas
Bottom Ash Cooling Water System/
Handling System (Fill*)/Type of Water
Dry Once-Through and
Cooling Tower (Wood)/
Fresh
Wet Once-Through Once-Through/Fresh
N/A Once-Through/Brackish
Wet Once-Through Once-Through/Fresh
Cooling Tower/Fresh
Wet Once-Through Once-Through and
Cooling Tower (P¥C)/
Fresh
(Asbestos) /Fresh
NA = Not Applicable
s Insufficient Information
*Type of Fill in Cooling Towers; given where appropriate,
-------
Table V-2 (Continued)
CHARACTERISTICS OF PLANTS SAMPLED IN THE VERIFICATION PHASE
u»
Plant
No.
3404
5409
5604
4602
3920
3924
3001
Capacity
"MW
475.6
2,900
750
22
544
87.5
50.0
Fuel Type
Bituminous
Coal/Oil
Bituminous
Coal/Oil
Bituminous
Coal /Oil
Subbitumi-
nous Coal
Bituminous
Coal/Oil
Bituminous
Coal
Lignite
Coal /Gas
Fly Ash
Hand ling. Sy s t em
Wet Once-Through
Wet Once-Through
Dry/Wet Recycle
Dry
Wet Once-Through
Wet Once-Through
Wet Once -Through
and Wet Recycle
Bottom Ash Cooling Water System/
Handling System Type of Water _
Wet Once-Through Once-Through and
Cooling Tower
(Asbes tos ) / Brackish
Wet Once-Through Cooling Towerw( )/
Fresh
Wet Once-Through/ Once-Through and
Wet Recycle Cooling Tower ( )/
Fresh
Wet Once-Through Cooling Tower (Wood)/
Fresh
Dry/Wet Once- Once-Through/
Through
Wet Once-Through Once-Through/ •-
Wet Once-Through Once Through/
NA
Not Applicable
Insufficient Information
*Type of Fill in Cooling Towers; given where appropriate.
— •— •» SSS
-------
Table V-2 (Continued)
CHARACTERISTICS OF PLANTS SAMPLED IN THE VERIFICATION PHASE
Plant
No.
1741
5410
2121
Capacity
MW Fuel Type
99.0 Bituminous
Coal
675 Bituminous
Coal
1,002.6 Bituminous
Coal
Fly Ash
Handling System
Wet Once-Through
Wet Once-Through
Wet Once-Through
Bottom Ash
Handling System
Wet Once-Through
Wet Once -Through
Wet Recycle
(Bottom Ash
Cooling Water System/
Type of Water
Cooling Ponds/
Once-Through/
Cooling Tower ( )/
Ul
OQ
Sluice Water
Recycled for Fly
Ash Sluicing)
NA = Not Applicable
= Insufficient Information
*Type of Fill in Cooling Towers; given where appropriate.
-------
4. Metal Cleaning Wastes
5. Boiler Fireside Washing
6. Air Preheater Washing
7. Coal Pile Runoff
A listing of the pollutants detected in the various powerplant waste
streams is given in table V-3.
COOLING WATER
i
In a steam electric powerplant, cooling water absorbs the heat that is
liberated from the steam when it is condensed to water in the
condensers. A typical type of condenser for steam electric power
applications is the shell and tube condenser. A crosssectional view
of this type of condenser is provided in figure V-2. Cooling water
enters the condenser through the inlet box and passes through the
condenser tubes to the outlet box. As the water passes through the
tubes, heat is transferred across the tube walls to the cooling water.
from steam contained in the condenser shell. The steam in the shell
is the turbine exhaust. The transfer of heat to the cooling water
results in condensation of steam on the condenser tubes. The
condensate falls from the tubes to the bottom of the shell forming a
pool in the hot well. The condensate is then pumped from the hot well
through the feedwater train to the boiler. Cooling water is
discharged from the condenser through the outlet box (3).
Once-Through Cool ing Water Systems
In a once-through cooling water system, the cooling water is withdrawn
from the water source, passed through the system, and returned
directly to the water source. The components of the system are the
intake structure, the circulating water pumps, the condensers, and the
discharge conduit. The components of a typical intake structure are
the intake cowl, the conduit, and the wet well. Each intake cowl
contains a bar rack to remove large objects from the water in order to
protect the pumps. The wet well contains the pumps, called the
circulating water pumps, and screens for removing smaller objects in
the water which could damage the pumps. The relative location of the
components in a particular application depends on the type of water
source and various physical characteristics of the water source. The
discharge from the recirculating water pumps enter a manifold that
distributes the cooling water to the condensers. A manifold collects
the heated water from all of the condensers and transfers the water to
a conduit. The cooling water is discharged from the conduit into the
receiving water body. Based on 308 data, approximately 65 percent of
the existing steam electric powerplants have once-through cooling
water systems. Table V-4 presents a statistical analysis of once-
through cooling water flow rates reported in 308 responses from the
industry.
59
-------
Table V-3
SUMMARY TABLE OF ALL PRIORITY POLLUTANTS DETECTED
IN ANY OF THE WASTE STREAMS FROM STEAM ELECTRIC
POWERPLANTS BASED ON THE ANALYSIS OF THE COMPLETE
COMPUTERIZED DATA
Benzene
Chlorobenzene
1,2-Dichloroethane
1,1,1-Triehloroethane
1,1,2-Trichloroethane
2-Chloronaphthalene
Chloroform *
2-Chlorophenol
1,2-Diehlorobenzene
1,4-Dichlorobenzene
1,1-Diehloroethylene
1,2-Trans-Dichloroethylene
2,4-Dichlorophenol
Ethylbenzene
Methylene Chloride
Bromoform
Diehlorobromomethane
Trichlorofluoromethane
Chlorodibromomethane
Nitrobenzene
Pentachlorophenol
Phenol
Bis(2-Ethylhexyl) Phthalate
Butyl Benzyl Phthalate
Di-N-Butyl Phthalate
Di-N-Octyl Phthalate
Diethyl Phthalate
Dimethyl Phthalate
Tetrachloroethylene
Toluene
Trichloroethylene
4,4-ODD
Antimony (Total)
Arsenic (Total)
Asbestos (Total-Fiber's/Liter)
Beryllium (Total)
Cadmium (Total)
Chromium (Total)
Copper (Total)
Cyanide (Total)
Lead (Total)
Mercury (Total)
Nickel (Total)
Selenium (Total)
Silver (Total)
Thallium (Total)
Zinc (Total)
60
-------
Cooling
liquid Intel
1
Noncondanubli
' get outl«t
Vapor Inlet
Cooling
liquid ouiiet
Figure V-2
SHELL AND TUBE CONDENSER
Reprinted from Handbook of Chlorination by G. C. White by permission of Van Nostrand
Reinhold Company^Year of first publication: 1972.
-------
Table V-4
ONCE-THROUGH COOLING WATER FLOWRATES
(308 Questionnaire)
Number
of Minimum
Variable Plants Mean Value Standard Deviation Value Maximum Value
Fuel: Coal*
Flow: GPD/plant 239 298,048,949 358,035,167.6 50.0 1,662,900,000
Flow: GPD/MW 239 1,140,619,218 5,030,338,485 0.347 55,430,000
Fuel: Gas*
Flow: GPD/plant 105 206,671,665.8 539,322,309.7 79.2 1,905,000,000
Flow; GPD/MW 104 636,267,895 573,486.38 1.8 3,658,536,585
Fuel: Oil*
Flow; GPB/plant 138 393,313,121.5 687,433,085.8 1.91 7,056,000,000
Flow; GPD/MW 137 1,385,121.179 4,991,663.852 0.013 58,074,074.07
*Fuel designations are determined by the fuel which contributes the most Btu for power
generation for the year 1975.
-------
Recirculatinq Cooling Water Systems
In a recirculating cooling water system, the cooling water is
withdrawn from the water source and passed through the condensers
several, times before being .discharged to the receiving water. After
each pass through the condenser, heat is removed from the water. The
heat is removed from the cooling water by three major methods:
cooling ponds or cooling canals, mechanical draft evaporative cooling
towers, arid natural draft evaporative cooling towers.
Cooling ponds are generally most appropriate in relatively dry
climates and in locations where large land areas are available. In
some cases where land area is not readily available, spray facilities
have been installed to reduce the needed pond size. Approximately
half of the steam electric industry's cooling ponds are in the
Southwest (Texas and Oklahoma), a quarter in the Southeast, and the
remainder mainly in the Midwest. Cooling ponds normally have a water
retention time of 10 days or more and, for a large steam electric
plant, usually have a surface area in excess of 500 hectares.
Chemical addition requirement for cooling ponds is significantly less
than for cooling towers.
The mechanical draft evaporative cooling tower is by far the most
popular, cooling method for recirculating cooling water in large steam
electric powerplants. The mechanical draft towers, shown in figure V-
3, use fans to move air past the droplets or films of water to be
cooled. Evaporation of water into the air stream provides the primary
mechanism for cooling.
Like the mechanical draft towers, the natural draft towers rely on
water evaporation for cooling effect. However, fans are not used to
induce air through the tower. Instead, the tower is designed so that
air will naturally flow from the bottom to the top of the tower as a
result of density differences between ambient air and moist air inside
the tower and the chimney effect of the tower's tall structure.
Natural draft towers are often selected over mechanical draft towers
in areas where low wet bulb temperatures and .high humidity prevail. A
sketch of this type of tower is shown in figure V-4.
More than 120 natural draft cooling towers were installed or planned
by 1976 (6). The first towers installed in this country were
concentrated in the Appalachian Mountains as a solution to the problem
of getting plumes up and out of local valleys. As of 1976, however,
towers were in operation or on order in 23 states. While the number
of units may represent as little as 20 percent of the total number of
cooling towers at powerplants, the megawatt capacity they represent is
far higher since natural draft towers usually are constructed for the
larger, newer plants. Natural draft cooling towers are expected to
account for almost 50 percent of new generating capacity requiring
cooling towers. All of the hyperbolic natural ^draft cooling towers
built in the United States to da'te have been of concrete construction.
Cooling tower fill can be made of polyvinyl chloride, asbestos cement,
ceramic or wood.
63
-------
AIR
OUTLET
WATER
INLET
FAN
WATER
WLET
MECHANICAL DRAFT
CROSS-FLOW TOWER
AIR
OUTLET
t t
FAN
«<«««««<
"JH^'"" >^ V"^
t vr.NJ sX
DRIFT
FILL
WATER OUTLET
MECHANICAL DRAFT
COUNTER-FLOW TOWER
WATER
INLET
INLET
Figure V-3
MECHANICAL DRAFT COOLING TOWERS (4)
-------
DRIFT
ELIMINATOR
FILL
HOT
WATER
INLET
HOT WATER
DISTRIBUTION
AIR
INLET
COLD WATER
BASIN
Figure V-4
NATURAL DRAFT EVAPORATIVE COUNTEWLOW COOLING TOWER (5)
65
-------
The water that evaporates from a recirculating cooling water system in
cooling ponds or cooling towers results in an increase in the
dissolved solids content of the water remaining in the system; thus,
the dissolved solids concentration will tend to build up over time and
will eventually, if left unattended, result in the formation of scale
deposits. Scaling due to dissolved solids buildup is usually
maintained at an acceptable level through use of a bleed stream called
cooling tower blowdown. A portion of the cooling water in the system
is discharged via this stream. The discharged water has a higher
dissolved solids content than the intake water used to replace the
discharged water, so the dissolved solids content of the water in the
system is reduced. Table V-5 presents a statistical analysis of
cooling tower blowdown based on 308 data.
In some recirculating systems, chemical additives that inhibit scale
formation are added to the recirculating water. These additives are
discharged in the cooling tower blowdown.
Chlorination
Biofouling occurs when an insulating layer of slime-forming organisms
forms on the waterside of the condenser tubes, thus inhibiting the
heat exchange process. The slime-forming organisms consist of fungi,
bacteria, iron bacteria, and sulfur bacteria. The exact mechanics of
blofouling are not fully understood, but the steps are believed to
consist of a roughening of the metal surfaces by abrasion; attachment
of bacteria and protozoa; entrapment of particulate matter by the
slime growth; and the deposition of successive layers of slime-forming
organisms and particulate matter (3).
Chlorination is the most widely practiced method of biofouling control
for both once-through and recirculating cooling water systems. Based
on the '308' data and Federal Power Commission data, about 65 percent
of the 842 steam electric plants use chlorine for biofouling control.
The remaining plant either do not have a significant biofouling
problem or use a method of control other than chlorine. If the intake
water has certain characteristics, e.g., high suspended solids
concentration or low temperature, biofouling is not a problem with
once-through cooling water systems. With recirculating cooling water
systems, Chlorination may still be required in order to protect the
cooling tower. The alternatives to chlorine include other oxidizing
chemicals, nonoxidizing biocides, and mechanical cleaning. None of
these alternatives are widely used at this time, so Chlorination is
clearly the predominant method of biofouling control.
The properties of chlorine that make it an effective biofouling
control agent are precisely the properties which cause environmental
concern. The addition of chlorine to water causes the formation of
toxic compounds and chlorinated organics which may be priority
pollutants. The available information on the reaction mechanisms and
products of chlorine with fresh and saline waters is summarized in the
following two subsections.
66
-------
Table V-5
COOLING TOWER SLOWDOWN
(308 Questionnaire)
Number
of
Variable Plants
Fuel:
Flow:
Fuel:
Flow:
Flow:
Flow:
Coal*
GPD/ plant
GPD/MW
Gas*
GPD/ plant
GPD/MW
Oil*
GPD/ plant
GPD/MW
82
82
120
119
47
47
Mean
2,232
2
315
3
274
1
Value
,131
,973.251
,951.9
,080.131
,193.2
,862.413
Minimum
Standard Deviation Value
5,452
7
505
4
584
3
,632
,308
,504
,851
,273
,428
.6
.87
.6
.049
.3
.478
0
0
0
0
0
0
.00
.00
.00
.00
.00
.00
Maximum Value
40,300
63
2,882
26
3,200
16
,000
,056.68
,880
,208.00
,000
,712.00
*Fuel designations are determined by the fuel which contributes the most Btu for power
generation for the year 1975.
-------
Fresh Water
When chlorine is dissolved in water, hypochlorous acid and
hydrochloric acid are formed:
C12 + H20 £ HOC1 + HC1 (1)
The reaction occurs very rapidly. In dilute solutions with pH levels
greater than 4, the equilibrium is displaced far to the right;
therefore, very few chlorine molecules (C12) exist in solution.
Hypochlorous acid is a weak acid that particularly dissociates in
water to the hydrogen ion and the hypochlorite ion:
HOC1 * H+ + OC1- (2)
The equilibrium of this reaction is a function of pH as shown in
figure V-5. As pH increases, the ratio of hypochlorite ion to
hypochlorous acid increases. The concentrations of hypochlorous acid
plus hypochlorite ion in solution is termed free available chlorine.
Chlorine may be applied to water not only in the pure C12 form but
also in compound form, usually as hypochlorite. Hypochlorites are
salts of hypochlorous acid. The two most commonly used hypochlorites
are calcium hypochlorite, a solid, and sodium hypochlorite, a liquid.
When sodium hypochlorite is dispersed in water, hypochlorous acid and
sodium hydroxide are formed:
NaOCl + H20 $ HOC1 + NaOH (3)
*
Hypochlorous acid then partially dissociates in accordance with
Equation 2; therefore, whether chlorine gas or hypochlorite are added
to water, the end chlorine-containing products are hypochlorous acid
and hypochlorite ion.
Both hypochlorous acid and hypochlorite ion are potent oxidizing
agents. The source of this oxidizing potential is the chlorine that,
at a oxidation state of +1, can accept two electrons in being reduced
to the -1 state. Hypochlorous acid is superior to hypochlorite ion as
a biocide. The primary reason for this superiority is the relative
ease with which hypochlorous acid can penetrate biological organisms.
As a result of the . biocidal efficiency of hypochlorous acid, an
equilibrium shifted to the left in Equation 2 is preferred in most
applications. The achievement of such an equilibrium position is
aided by using chlorine since one of the reaction products,
hydrochloric acid, lowers the pH of the water; but the achievement of
this equilibrium position is impeded when using hypochlorite since one
of the reaction products, sodium hydroxide, raises the pH of the
water.
Since hypochlorous acid is an oxidizing agent, a considerable amount
of free available chlorine may be consumed in reactions with
inorganic-reducing materials in water before any biocidal effect is
accomplished. Cyanide, hydrogen sulfide, iron, and manganese are
68
-------
HJU
90
80
70
EO
50
40
30
20
10
n
j-
\
\
1
\
\
\\
\\
20-C\\
\
\09C
\\
%
^
u
10
20
30
40
•50^
;
SO
80
90
t^n
PH
Fig-ure V-3 - .
EFFECT OF pH ON THE DISTRIBUTION OF HYPOCHLOROUS ACID
AND HYPOCHLORITE ION IN WATER
Reprinted from Chemistry for Sanitary Engineers by C. N. Sawyer
and P. L. McCarty by permission of McGraw-Hill, Inc., Year of
first publication: 1967.
69
-------
among the substances which can be oxidized by hypochlorus acid. In
these reactions the Cl+ in hypochlorus acid is reduced to Cl- which
has no biocidal capability. The consumption of hypochlorous acid by
inorganic-reducing materials is termed chlorine demand. The demand
for chlorine by these substances must be satisifed before hypochlorous
acid is available for biocidal activity.
When sufficient hypochlorous acid is present to exceed chlorine
demand, the acid will react with ammonia and organic materials. The
reaction of ammonia with hypochlorous acid forms monochloramine and
water:
NH3 + HOC1 2 NHjCl + H20 (4)
This reaction occurs when the weight ratio of chlorine to ammonia is
less than or equal to 5:1. Monochloramine is a weak biocide. The
reactions of organic materials with hypochlorous acid can be divided
into two groups: reactions with organic nitrogen and reactions with
all other organic compounds. Compounds which contain organic nitrogen
are complex; therefore, the chemistry of chlorination of organic
nitrogen compounds is complex. The products of the reactions of
diverse organic nitrogen compounds with hyprochlorous acid are grouped
under the general term complex organic chloramines. The chemistry of
chlorination of other organic compounds is also complex. The products
of chlorination of other organic compounds are grouped under the
general term chlorine substitution and addition products. The organic
chloramines and the chlorine substitution and addition products are
weak biocides. The chlorine contained in these compounds and in
monochloramine is called combined chlorine residual. The word
"residual" denotes that this is the chlorine remaining after
satisfaction of chlorine demand, while the word "combined" denotes
that the chlorine is tied up in compounds.
Further addition of hypochlorous acid so that the weight ratio of
chlorine to ammonia exceeds 5:1 results in the conversion of some of
the monochloramine to dichloramine:
NH2C1 + HOC1 2 NHC12 + H20 (5)
As the weight ratio of chlorine to ammonia increases to 10:1, the
dichloramine and the organic chloramines and chlorine substitution and
addition products begin to decompose. The exact mechanism and
products of this decomposition are still incompletely defined. The
decomposition consumes hypochlorous acid, so a chlorine demand is
again exerted. The decomposition also decreases the combined chlorine
residual level. Decomposition ceases at a weight ratio of chlorine to
ammonia of 10:1. At this point, the combined available chlorine
residual consists of approximately equal amounts of monochloramine and
dichloramine. Like monochloramine, dichloramine is a weak biocide.
As the weight ratio of chlorine to ammonia proceeds to 20:1 through
addition of hypochlorous acid, the conversion of monochloramine to
70
-------
dichloramine is greatly speeded and some dichloramine is converted to
trichloramine, also called nitrogen trichloride:
NHC12 + HOC1 2 NCI3 + HZ0 (6)
Regardless of the form of the combined available chlorine residual,
the amount of the residual remains constant at the level present when
the chlorine to ammonia weight ratio was 10:1. The quantity of
hypochlorous acid added that is not involved in the chloramine
reactions is, therefore, present as free available chlorine residual.
Hypochlorous acid is, as previously stated, a powerful biocide.
The effect of various impurities in water on the disinfecting power of
hypochlorous acid, described by the preceding series of equations, is
illustrated in figure V-6. Total available chlorine residual, which
includes both combined available chlorine residual and free available
chlorine residual, is the measure of total biocidal power. As
hypochlorous acid is added to water, the total available chlorine
residual passes through four stages. In the first stage, no residual
is formed, because chlorine is being reduced by inorganic materials.
In the second stage, a residual, consisting of only combined available
chlorine, is formed and continuously increases as monochloramine,
organic chloramines, and chlorinated organics are formed. In stage
three, the residual, still consisting of only combined available
chlorine, decreases as monochloramine is converted to dichloramine and
the dichloramine and the organic compounds undergo further reactions.
In the fourth stage, the residual increases continuously. The
residual in this stage consists of both combined available chlorine
and free available chlorine. In most water treatment operations,
sufficient hypochlorous acid is provided to operate in stage four in
order to take advantage of the biocidal power of hypochlorous acid.
A great deal of research has been conducted on the formation of
chlorinated organics in fresh water. Some of the chlorinated organics
are in the list of 129 priority pollutants (i.e., bromoform and
chloroform). One of the experiments to examine chlorination of
organics resulting from chlorinated cooling waters was performed by
Jolley, et al (7). Over 50 chlorinated organics were isolated from
concentrates of.Watts Bar Lake water and Mississippi River water which
were chlorinated at concentrations of 2.1 mg/1 (75 minutes reaction
time) and 3.4 mg/1 (15 minutes reaction time). The chlorinated
organics formed were in ppb concentrations.
In view of the finding of the National Organics Reconnaissance Survey
that halogenated organics in raw and finished drinking water are
widespread and distributed with a frequency shown in figure V-7, EPA
Municipal Environmental Research Labs (8) sought to investigate the
mechanism for the formation. Suspecting humic substances to be the
precursors, they tested this hypothesis. At concentrations of humic
acid representing the non-volatile total organic carbon (NVTOC)
concentrations found in the Ohio River (3 mg/1), they observed that
the rate of trihalomethane formation was similar to that observed in
Ohio River water.
71
-------
OS-
O
I
0.4
Q3-
02
0.1
FOftUATiONOF ntErCHUMINE JkW
PRESENCE OF CHIOMO-ORSANIC
COMPOUNDS NOT DESTROYED
o ai &2 03 0.4 as os 0,7 oa ^S
CHLORINE ADDED AS BZPOCHLOROUS ACID
LO
Figure ?-6
EFFECT OF IMPURITIES IN WATER ON TOTAL AVAILABLE .
CHLORINE RESIDUAL
Reprinted from Manual af Instruction for Water Treatment Plant
Operators by New York State Department of Health by permission
of New York State Health. Education Service. Year of first
publicat ion: unknown.
72
-------
300
2 5 10 30 50 70 9Q 99
PERCENT EQUAL TO OR LESS
THAN GIVEN CONCENTRATION
Figure V-7':
JRIQUEN8Y'DISTRIBUTION OF HALOGENATED ORGANICS
IN RAW AND FINISHED DRINKING WATER (8)
73
-------
The major mechanism for trihalomethane reactions in natural waters is
the haloform reaction (9) that is a base catalyzed series of
halogenation and hydrolysis reactions which occur typically with
methyl ketones or compounds oxidizable to that structure. Humic and
fulvic substances have been postulated as precursors to
trichloromethane formation. Humic materials are composed of aromatic
and alicyclic moieties containing alcoholic, carbonyl carboxylic, and
phenolic functional groups, which can participate in trihalomethane
formation by ionizing to form carbonions rapidly.
Unfortunately, data on the formation of trihalomethanes in cooling
water effluents is not readily available. Several of the variables
which influence chloroform formation have been investigated by the
Louisville Water Company (10). A conventional treatment process of
sedimentation, coagulation with alum, softening, recarbonization, and
filtration is practiced. Primary disinfection is accomplished by
chlorination at the head of the coagulation process. The chlorine
residual leaving the plant is approximately 2.0 ppm. The correlation
between total trihalomethanes and water temperature is shown in figure
V-8. It is evident that seasonal variation in influent water
temperature could vary the effluent chloroform concentration by a
factor of 2-3 times. There are marked increases in chloroform
formation with increases in pH as shown in figure V-9. Figure V-10
shows the effect of contact time on chloroform formation.
Saline Water
When chlorine gas is dissolved in saline water, the chemical reactions
which occur initially are identical to the reactions which occur when
chlorine gas is dissolved in fresh water. Once hypochlorous acid and
hypochlorite ion are in equilibrium in solution, the bromide present
in saline water is oxidized and hypobromous acid and hypobromite ion,
respectively, are formed:
HOC1 + Br £ . HOBr + Cl (7)
Br- + 3C10 $ BrQ-3 + 3C1- (8)
The oxidiaation occurs because chlorine has a higher oxidation
potential than bromine. The equilibriums in these reactions are
normally displaced to the right; hence, hypobromous acid and
hypobromite ion are more prevalent in solution than hypochlorous acid
and hypochlorite ion.
The four oxidizing compounds: hypochlorous acid, hypochlorite ion,
hypobromous acid, and hypobromite ion are believed to behave in saline
water similar-ly to hypochlorous acid and hypochlorite ion in fresh
water. The reactions and the reaction products in each of the four
stages described for fresh water are not conclusively defined for
saline water. The presence in saline water of numerous chemical
species not found in fresh water leads, to many side reactions
triggered by the four oxidizing compounds. These side reactions
74
-------
•5 200
C /GO
Figure V-8
EFFECT OF WATER TEMPERATURE ON THE
CHLOROFORM REACTION
Reprinted from Hubbs, S.A., et al., "Trihalomethane Reduction
at the Louisville Water Company," Louisville Water Company,
Louisville, KY,"undated.'
-------
5 »
& 7
10 //
Figure V-g
EFFECT OF pH ON THE CHLOROFORM REACTION
Reprinted from Hubbs, S. A., et al., "Trihalomethane Reduction
at the Louisville Water Company," Louisville Water Company,
Louisville, KY, undated.
76
-------
Figure V-10
EFFECT OF CONTACT TIME ON THE CHLOROFORM REACTION
Reprinted from Hubbs, S. A., et al., "Trihalbmethane Reduction
at the Louisville Water Company," Louisville Water Company,
Louisville, KY, undated.
77
-------
obscure the main reactions which result in the difficulty in defining
the primary reactions and reaction products. In spite of this
difficulty, some progress has been made in defining reaction products,
particularly in Stage 4. In this stage, the free residual probably
contains the four oxidizing compounds and the, combined residual
probably contains chloramines, bromamines, chloro-organics, and bromo-
organics. ;
Bean, et al. (11), chlorinated Seguim Bay waters at a rate of 1-2 mg/1
chlorine for approximately 2 hours. This is relatively pristine water
with approximately 1 mg/1 TOG. Principle reaction products were
bromoform (30 mg/1) with smaller quantities of dibromomethane and
traces of dichloromethane.
Carpenter (12) found that bromoform, and to a lesser extent,
chlorodibromomethane were formed upon chlorination of Biscayne Bay
waters. Typically, organic constituents range from 9-12 ppb dissolved
organic carbon. Chlorination to 1 mg/1 produced 36 ppb CHBr3 in
unfiltered water and 43 ppb CHBr3 centrifuged water. It is postulated
that chlorine reacts with' the particulate matter and prevents
oxidation of bromine to a certain extent in the former case.
Corrosion Products
Corrosion is an electrochemical process that occurs when metal is
immersed in water. A difference in electrical potential between
different parts of the metal causes a current to pass through the
metal between the anode, the region of lower potential, and the
cathode, the region of higher potential. The migration of electrons
from the anode to the cathode results in the oxidization of the metal
at the anode and the dissolution of metal ions into the water (13).
Most metals rely on the presence of a corrosion products film to
impart corrosion protection. In the case of copper alloys, which are
used extensively in powerplant condensers, this film is usually Cu20.
As a result, copper can usually go into the corrosion product film or
directly into solution as an ion or a precipitate in the initial
stages of condenser tube corrosion. As corrosion products form and
increase in thickness, the corrosion rate decreases continually until
steady state conditions are achieved. The data presented in table V-6
lend support to the corrosion product film theory as applied to
condenser tubes. The plant that was sampled had three units. Unit 3
had just begun operation and contributed the most copper to the
cooling water. Unit 1 had been in operation for a longer period of
time and contributed the least amount of copper to the cooling water.
Unit 2 was not considered in the comparison because mechanical
cleaning was used to control biofouling which artificially increased
the copper contribution to the cooling water (14).
Waters high in dissolved solids are more conductive; therefore, plants
using saline water for cooling should have higher metals
concentrations in the cooling water discharge than plants using fresh
water. Popplewell and Hager (15) observed that the long term
7-8
-------
Table V-6
COPPER CORROSION DATA (14)
Condenser
Material
Comment
Copper Added to Cooling Water by
Passing Through the Condenser*
Soluble Particulate
(UR/1) (Ug/l)
Unit 1 Aluminum-brass
76-79 percent
copper
Unit 2 90/10 copper
nickel alloy
Unit 3 90/10 copper
nickel alloy
Considered to be
equilibrated with
the environment
Mechanical anti-
fouling system
was used
Had been operating
intermittently for
only a few months
No statistically
significant addition
6.70
11.8
1.28
7.76
1.8
^Average of hourly samples over a 24 hour sampling period; corrected for copper
concentrations at the intake.
-------
corrosion rate of alloy 706 (90/10-copper/nickel) does not differ
significantly in different environments. A summary of these results
is shown in table V-7. Copper release is more a function of flow rate
than it is of salt content of makeup water. A study was undertaken by
a utility (16) to determine concentrations of cadmium, chromium,
copper, nickel, lead, and 2inc in the influents and effluents of eight
coastal generating stations. The composite data in table V-8 for all
eight plants sampled shows that in 11 of the 12 available comparisons,
the median difference between effluent and influent concentration was
positive, suggesting a net addition of trace elements as a result of
corrosion. However, only copper in the dissolved state and zinc in
the suspended were increased in excess of 0.1 ppb. The data from
these two studies do not indicate higher metal concentrations in
saline cooling water compared to fresh cooling water and, regardless
of the type of water, do not indicate that significant increases in
metals concentrations are occuring because of cooling system
corrosion.
Data on soluble copper concentrations in the recirculating cooling
water systems at three plants are summarized in table .V-9. The
soluble copper concentrations in the intake water are also provided as
a baseline. Copper concentrations increase markedly in the tower
basin and the drift and increase dramatically in sludge in the towe^
basin (155. Based on this data, it appears that corrosion products
are more of a problem in cooling tower blowdown (tower basin in table
V-9) than in once-through cooling water discharge. The concentration
of pollutants (via evaporation) in recirculating systems probably
accounts for most of the difference in the level of metals observed
between once-through discharge and cooling tower blowdown,
Products ofChemical Treatment
Chemical additives are needed at some plants with recirculating
cooling water systems in order to prevent corrosion and scaling.
Chemical additives are also occasionally used at plants with once-
through cooling water system for corrosion control.
Scaling occurs when the concentration of dissolved materials, usually
calcium and magnesium containing species, exceeds their solubility
levels. Solubility levels are influenced by, among other things,
water temperature and pH. The addition of scaling control chemicals
allows a higher dissolved solids concentration to be achieved before
scaling occurs; therefore, the amount of blowdown required to control
scaling can be reduced. Control of scaling is an important plant
cooling systems operational consideration. Severe scaling can
drastically alter cooling systems fluid flow characteristics and
result in reduced heat transfer, high pressure drops, and other
undesirable effects.
Chemicals added to once-through cooling water to control corrosion or
to recirculating cooling water to control corrosion and scaling will
usually be present in the discharges. A list of chemicals commonly
used to control corrosion and scaling is presented in table V-10 (17).
ao
-------
Table V-7
ONE YEAR-STEADY'STATE-CORROSION RATES
FOR ALLOY 706 DETERMINED EXPERIMENTALLY (15)
New Haven
Tap Water
Brackish Water
0.1%. NaCl
Salt Water
3.4% NaCl
0.1 mils/yr
0.1 tnils/yr
0.1 mils/yr 0.2 mils/yr
at velocity
of 7 ft/sec
at velocity
of 7 ft/sec
at velocity at velocity
of 7 ft/sec of 12 ft/sec
81
-------
Table V-8
SELECTED PRIORITY POLLUTANT CONCENTRATIONS IN
SEAWATER BEFORE AND AFTER PASSAGE THROtJGH
ONCE-THROUGH COOLING WATER SYSTEM (16)
Median Influent
Concentration
Net Concentration
Change (Effluent-Influent)
(PPb)
Metal
Cd
Cr
Cu
Ni
Pb
Zn
Dissolved
0.06
0.16
0.80
" o;44
0.14
0.20
Particulate
0.006
0.200
0.320
0.160
0.24
0.48
. (ppb) ;
Dissolved
0.034
(0.010)*
0.21
0.10
0.04
0.09
Particulate
0.005 •
0.097
0.10
0.004
0,07
0.17
*Negative value.
82
-------
Table V-9
SOLUBLE COPPER CONCENTRATIONS IN
RECIRCULAT1NG COOLING WATER SYSTEMS (15)
Location of
sample
River influent
Tower Basin
Tower basin mud
Tower drift
Plant 1
2 years
operation
.23
PPb
7.0 1.8
6.45 88
-* 560,000
6.43 76
Plant 2
1 year ,
operation
pH
6.§
6.6
.*
6.5
PPb
1
35- ;
670,000
34
Plant 3
1 week
operation
pH
_*
6.9
.*
_*-
PPb
_*
75
_*
_*
*Measurement not taken.
83
-------
Table V-10
COMMONLY USED CORROSION AND SCALING CONTROL CHEMICALS (17)
Benzotriazole and its sodium salt
*Chromic Acid
Nitrilo-tris acetic acid and its alkali metal and ammonium salts
Organophosphorous Antiscalants including 1-Hydroxyethylidene-1,
1-diphosphonic acid, Nitrilo-tri (methy1enephosphonic acid)
(and the alkali metal and ammonium salts of each), and
Polyolphosphate esters of low molecular weight
Potassium hydroxide
Sodium bisulfate
Sodium carbonate
*Sodium dichromate
*Sodium chrornate
Sodium hexatnetaphosphate
Sodium hydroxide
Sodium mercaptobenzothiazole
Sodium molybate
Sodium nitrate
Sodium nitrite
Sodium phosphate (mono-, di-, tri-)
Sodium silicates
Sodium tetraborate
Sodium tripolyphosphate
Sulfamic acid
Sulfuric acid
Tetrasodium pyrophosphate
Tetrapotassium pyrophosphate
Ethylenediamine tetra-acetic acid and its alkali metal and
ammonium salts
Tolyltriazole
*Zinc chloride
84
-------
Table V-10.(Continued)
**v
COMMONLY USED CORROSION AND SCALING CONTROL CHEMICALS (17)
*Zinc oxide
*Zinc sulfate
Tannins
Sodium Boro-polyphosphate
*Sodium Zinc Polyphosphate
*Calcium Zinc Polyphosphate
Sodium Acid Pyrophosphate
Phosphoric acid
Ethylene diamine tetrakis (methylene phosphonic acid) and its
alkali metal and ammonium salts
Hexamethylene diamine tetrakis (methylene phosphonic acid) and
its alkali metal and ammonium salts
Diethylene triamine pentakis (methylene phosphonic acid) and
its alkali metal and ammonium salts
Sodium polystyrene sulfonate and copolymers
Carbon dioxide
Monobutyl esters of polyethylene - and polypropylene glycols
Acrylamide polymers and copolymers
Polyoxypropylene glycols (min. tnol. wt. 1,000)
Sodium carboxymethylcellulose
Sodium lignosulfonates .
Sodium polyacrylates and polyacrylic acids
Sodium polymethacrylates
Styrene - inaleic anhydride copolymers
Polyethyleiiimines
Sodium citrate
Alkyphenoxy polyethoxy ethanols
Dioctyl sodium sulfosuccinate
85
-------
Table V-10 (Continued)
COMMONLY USED CORROSION AND SCALING CONTROL CHEMttfALS (17)
Poly - (amine-epichlorohydrin) condensates
Poly - demethyl, diallyl ammonium chlorides
Poly - (amine-ethylene dichloride) condensates
NOTE: In many cases either sodium or potassium salts are in use.
*Indicates that the compound is known to contain a priority
pollutant. Some of the other compounds may contain or may
degrade into priority pollutants but no data was available to
make a definite determination.
86
-------
Those compounds which are priority pollutants are marked with an
asterisk to the left of the compound name. Chromium and zinc ace the
active components of most of the popular corrosion inhibitors. Both
these metals are inorganic priority pollutants. The solvent and
carrier components which may be used in conjunction with scaling and
corrosion control agents are listed in table V-ll tl7). The
pollutants which were reported as present in recireflating cooling
water on the 308 data base forms are found in table V-12. In addition
to the chemicals listed in this table, acrolein and asbestos have been
reported.
Products o_f Asbestos Cooling Tower Fill Erosion
The fill material in natural draft cooling towers is frequently
asbestos cement. Erosion of the fill material can cause discharge of
asbestos in cooling water blowdown. Table V-13 shows the test results
for detection of asbestos fibers in the waters of 18 cooling systems.
Baseline data on chrysotile asbestos concentrations in makeup water
are also contained in the table. Seven of the 18 sites contained
detectable concentrations of chrysotile asbestos in the cooling tower
waters at the time of sampling. Most of the samples containing
detectable chrysotile were samples of basin water. Data in the last
three columns of the table for Site 3 indicate that a settling pond or
lagoon interposed between the cooling towers and the receiving water
removes asbestos since it was not detectable in the effluent (4).
Sampling Programs Results
Once-Through Cooling Water Systems
Three plants that use only once-through cooling water systems were
sampled during the screening phase of the sampling program. Table V-
14 present trace metal data for these plants from the screening
program. The duration of chlorination at all three plants .did not
exceed 2 hours per day. Net increases were observed for antimony,
arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium,
thallium, and phenol. However, net increases were greater than 10 ppb
only for arsenic, cadmium, nickel, selenium, and phenol. Only in the
case of arsenic was the net increase greater than 25 ppb.
Eleven plants with once-through cooling water systems were sampled as
part of the verification program and the surveillance and analysis
sampling efforts. The analytical results are presented in Table V-15.
Four of these plants have estuarine or salt water intakes, and the
remaining seven plants have fresh water intakes. Samples were
collected only during the period of chlorination. The samples were
analyzed for all the organic priority pollutants except the
pesticides, and for total organic carbon and total residual chlorine.
Only the organic priority pollutants which were detected are shown.
Analysis for total residual chlorine (TRC) was performed at nine of
the plants.
87
-------
Table V-ll
SOLVENT OR CARRIER COMPONENTS THAT MAY BE USED
IN CONJUNCTION WITH SCALING AND CORROSION CONTROL AGENTS (17)
Dimethyl Formamide
Methanol
Ethylene glycol monomethyl ether
Ethylene glycol monobutyl ether
Methyl Ethyl Ketone
Glycols to Hexylene Glycol
*Heavy aromatic naphtha
Cocoa diamine
Sodium chloride
Sodium sulfate
Polyoxyethylene glycol
Talc
Sodium Aluminate
Monochlorotoluene
Alkylene oxide - alcohol glycol ethers
*Indicates that the compound is known to contain a priority
pollutant. Some of the other compounds may contain or may
degrade into priority pollutants but no data was available
to make a definite determination.
88
-------
Table,V-12
POLLUTANTS REPORTED ON 308 FORMS IN COOLING TOWER SLOWDOWN
: -it; . '•' •: ' ,: ' '• •,:',: • . • • ••'•'.
Number of Plants
Compound Name Reporting Presence
Antimony and compounds 3
Arsenic and compounds 2
Cadmium and compounds 3
Chlorinated phenols 7
Chloroform 1
Chromium and compounds .36
Copper and compounds 8
EDTA 6
Lead and compounds 3
Mercury and compounds 2
Nickel and compounds 3
Pentachlorophenol 9
Phenol 2
Selenium and compounds 2
Silver and compounds 2
Thallium and compounds 2
Vanadium 2
Zinc and compounds 31
89
-------
Table V-13
ASBESTOS IN COOLING TOWER WATERS (4)
Anbeatos, fIbera/llCer ofMS/8 («ed)*
Kokeup Hater
Site Snapllng
Ho. Date
I 26 Hay 77
2 26 Hay 77
3 26 May 77
4 25 May 77
5 13 Nay 76
6 Oct 76
6 25 Hay 77
7 6 Jul 76
7a 15 Aug 77
Repli-
ca teg
a
b
c
a
b
c
a
b
c
a
b
c
a
a
b
a
b
c
a
a
b
c
Lower Unit
of Detection
6.3xl04
6.3xl04
6.3xl04
6.3x10*
6.3xl04
6,3xl04
8.4x10*
L
8.4x10*
8.4xl04
8.4x107 sup
7x10° sed
8.4x10, sup
8.4x10° aed
8.4x10* sup
7x10° aed
1,2x1 05
1.57xl05
6.3x10
6.3x10
6.3xl04
6.3xl05
4
6.3x10, sup
6.3x10^ sup
6.3x10 sup
Cone.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
O.SxlO6
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
Basin Hater
Lower Ll«lt
of Detection
4
6.4x10, oup
5.2x10° tied
6.3x10; sup
4.8x10? eed
6.3x10* sup
83x10 sed
6.3x10* sup
6
11x10. oed
6.3x10*! eup
9.1xlfl| aed
6.3x10, a up
7x1 0° ged
8.4x107. sup
5.2x107 aed
8.4x10"! sup
6.4x10° sed
8.4x10 aup
6.3x10? sup
220x10° sed
8.4x10 sup
LH 4 sed
8.3x10, sup
140x10 sed
O.SxlO6
1.57xlo!
1.57x10
8.4xl04
8.4x1 04
8.4xl04
1.26x10°
6.3x10*
Slowdown
Louer Limit
Cone.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L
44x1 08
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L
B.D.L
B.D.L.
B.D.L.
8,D.Lh
130xl08
B.D.L.
<0.5Z,
1.9x10**
78xl09
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
All B.D.L.
of Detection
6.3stl04
6.4x107
6.3x107
6.4x10?
6.3x10:!
7.5x1 O6
8.4x1 0J
8.4x10?
8.4x10
7x10°
2.6x10
8.7xl04
3.4x10*
1.7x10*
LH
0.8x10°
1.51.X105
6.3xl04
4.0x10*
6.3x1 o:
7.0x10?
l.SxlO3
2.1xl06
6.3x10,
6.3xlo!
6.3x10*
•up
aed
sup
aed
•up
sed
sup
sed
sup
Bed
sup
sup
sed
6 Up
sed
sup ,
aed
,
Cone.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
0.92x10
B.D.L.
110x10°
1.3xl06
160xl06
B.D.L.
<0.5Z
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
Other
Lower Lille
SaBple of Detection
Settling-pond 6.
effluent
4.
6.
5.
" " 6.
4.
Sediment from 2.
sump
Lagoon effluent 8.
** "
8.
8.
Potable water 0.
Basin water from 1.
MDCT that cools
NDCT blowdova
2.
" 6.
** 6.
3x10 sup
A
9x10° sed
3x10? sup
6x1 0| aed
3x10, sup
8x10? sed
1x10 sed
4xl04
L
4x10^
4xl04
12xl06
26x10°
9x10^
3x107
3x10
Cone.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
1
B.D.L.
B.D.L.
B.D.L.
B.D.L.
-------
Table V-.13 (Continued)
ASBESTOS IN COOLING TOWER WATERS (4)
Asbestos, fibers/liter of Ma/g .(sed)*'
Site
No.
8
9»
10
Sampli ng
Date
S Jul 76
2 Sep 76
31 Aug 76
Repli-
cates
8
b
C
a
b
c'
a
b
c
Makeup
Lower Limit
Water Basin Hater Slowdown . . Other
Lower Limit
of Detection Cone. of Detection
ljdQ5
1x10
1.88xlo!
1.88x10;
1.88x10
4.2x10?
6.3x10?
6.3x10
B.D.L. 2x10^
B.D.L. I.IxlOr
1x10
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
.88x10*
.88x10?
.88x10
.26x1 of
.26x10*
.26x10
Lower Limit Lower Limit
Cone. of Detection Cone. Sample of Detection Cone,
B.D.L. Towers had circulating
B.D.L. water but no hlowdown ,
B.D.L. (towers not yet "on line")
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
.88x10, 37x10
.88x10? B.D.L.
.88x10 B.D.L.
.26x10* B.D.L.
.26x10? B.D.L.
.26x10 B.D.L.
8
9b
10
11
11
12
12
13
13
14C
15
16
S Jul 76
2 Sep 76
31 Aug 76
15 Aug 77
(1 of 2
towers)
15 Aug 77
(2nd of 2
towers)
16 Aug 77
(Unit 3
tower)
16 Aug 77
(Unit 4
tower)
17 Feb 76
28 Apr 76
7 Hay 76
20 Jun 77
26 Aug 77
8
b
C
a
b
c'
a
b
c
a
b
c
a
b
c
a
b
c
a
b
c
a
a
a
b
c
d
a
b
c
a
b
c
2.3xl0
2.5x10,
2.9x10*
6.3x10;
2.3x10^
1.2x10
1.2x10
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
n5
6,38xl0
6.47x10°
2.9x10;
2.5x10 ,
6.36x10
2.5x10?
1.3x10
5.1x10
2.5x10,
2.3x10,
2.5x10
1.4xlOJ 2.5x10
(amphlbole)
5 6
5.9x10, raw B.D.L. 1.04x10
1.2x10 trtd B.D.L.
6.3x10"
6.3x10*
6.3x10*
6.3x10,
6.3x10*
6.3x10
8.4xlo| sup
8.4x10 sup
8.4x10* sup
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
370x1 0
330x10
B.D.L
B.D.L,
210x10
B.D.L.
B.D.L,
24xl06
B.D.L.
B.D.L.
B.D.L.
4.3xl06
2.5xl0
B.D.L.
B.D.L.
B.D.L.
B.D.L.
Settling-basin
effluent
1.8x10
2.5x10
6.3xl04
Ash-pond effluent 6.3xlO<
6.3x10,
2.8x10
4.7x10
1.04x10"
1.04x10)!
1.04x10°
1.04x10°
6.3x10?
6.3x10*
6.3x10
6.3x10* sup
6.3x10, sup
6,3x10 sup
B.D.L.
B.D.L.
B.D.L.
B.D.L..
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
Cooling-toner
" •• riser
2.5x10
2.5xl0
Park reservoir
6.3x107
6.3x10
Discharge canal 6.3x10, sup
" 6.3x10, sup
" " 6,3x10 sup
LM sed
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
1.5x10
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
B.D.L.
0.5Xd
-------
Table V-13 (Continued)
ASBESTOS IN COOLING TOWER WATERS (4)
AebestoB, fibcra/liter of UB/K (acd)*
Site
No.
17
17
Sampling
Date
21 Hay 76
Aug 76
teplt-
cates
a
a
b
Makeup Hater
Lower Limit
of Detection Cone.
1.2xl05 »5xl06
5
1x1 Of B.D.L.
1x10 B.D.L.
Basin Mater
Lower Limit
of Detection Cone.
6x10* B.D.L.
Slowdown
Lower Unit
of Detection Cone.
6x10* B.D.L.
5
1x1% B.D.L.
1x10 B.D.L.
Other
Lower Llnit
Saaple of Detection Cone.
IB- 21 Hay 76
1.2x10
B.D.L.
1.2x10
B.D.L.
^Concentrations are listed aa fibers/liter for bulk water samples (no postscript). In caeca where the bulk samples contained appreciable amounts
of suspended solids, the samples were shaken, allowed to stand 4 hours, and che supernatant analyzed by electron microscopy; results are Hated
in fibers/liter (sup). The sedinent was analyzed either by electron Microscopy or light microscopy (LH); the results of sediment analysis by
electron microscopy are listed as Mg/g (sed), and by light nicroacopy as a percent of the sedinent mass by weight. Concentrations (Cone.) below
detection limits are Indicated by B.D.L. Except as otherwise noted, all asbestos wna identified as chryaotlle.
''"Replicates teken at a given sampling date.
"Site 7 has four natural-draft towers. For basin-water analyses, two samples Here taken froa each of the four tower basins. The lower limit
of detection range from 6.3x10^ to 3.0x10-" for all eight samples.
''The lower limit of detection is relatively high due to high salt content in the water.
C81oudown saaples are froa four separate mechanical-draft toners, one of which contains redwood fill.
dC!brysotile was found by light ulcroscopy in the sediment suspended in the bulk water sample. Fibers were 2-5 pa in diameter, 60-130 [im in
length, in small bundles.
-------
10
Table V-14
RESULTS OF SCREENING PROGRAM FOR ONCE-THROUGH COOLING WATER SYSTEMS
(parts per billion)
Plant #2512
Plant #3805
Plant
Compounds
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Cyanide
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Phenol
Intake
<5
6
<5
<10
<5
22
<20
<5
0.21
7
35
<5
<5
<5
100
Discharge
10
70
<5
30
8
24
<20
<5
0.17
25
58
<5
13
<5
100
Intake
<5
<5
<5
<5
39
6
<20
19
0.23
<5
11
12
<5
<5
<10
Discharge
<5
<5
<5
<5
<5
5
<20
<5
0.32
<5
<5
<5
<5
<5
<10
Intake
7
18
<5
<5
24
16
20
8
0.42
29
20
<5
<5
42
30
Discharge
<5
25
<5
<5
17
20
20
14
0.42
26
18
<5
<5
26
50
-------
Table V-15
Plant
Code
2718
1716
VO
3414
4826
Pollutant
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE AND
ANALYSIS REPORTS FOR ONCE-THROUGH COOLING WATER SYSTEMS
Concentration (ppb)
Zinc
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Total Residual Chlorine
1,1,2,2-Tetrachloroethane
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Phenolics, 4AAP
Total Residual Chlorine
2,4-Dichlorophenol
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Phenolics, 4AAP
Total Residual Chlorine
1,2-Dlchlorobenzene
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Phenolics, 4MP
Total Residual Chlorine
1,2 or 1,3 or 1,4 Dlchlorobenzene
Intake
340
230,000
3,000
11,000
D < 10
5
250,000
7,000
34,000
12
D < 10
ND
23,000,000
16,000
25,000
15
D < 10
ND
12,200,000
17,000
12,000
8
D < 10
18
Discharge
380,000
4,000
17,000
20/20/20/20
5
360,000
10,000
15,000
7
400/7100/5100/D<10
4/8
24,000,000
8,000
26,000
7
250/320/310/280
30
12,300,000
21,000
30,000
18
1200/2000/1900/800
-------
Table V-15 (Continued)
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE AND
ANALYSIS REPORTS FOR ONCE-THROUGH COOLING WATER SYSTEMS
vO
un
Pollutant
1245 Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Phenolics, 4AAP
Total Residual Chlorine
1002 Bromofonn
Chlorodlbromomethane
Bis(2-Ethylhexyl) Pthalate
BHC(Lindane)~Gamma
Antimony, Total
Cadmium, Total
Chromium, Total
Copper,-Total
Lead, Total
Mercury, Total
Nickel, Total
Silver, Total
Zinc, Total
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Total Residual Chlorine
Free Residual Chlorine
Iron, Total
Concentration (ppb)
Intake Discharge
35,000,000
6,000
14,000
D < 5
D < 10
420
16
17
13
22
10
ND
120
30
- 32
11,488,000
38,400
8,150
0/0/200/300/400/540/900
200/1000/700/500/700/300/500
600
33,000,000
14,000
25,000
D < 5
D<10/200/120
31
2.6
D < 0.1
14
16
14
24
11
1
120
36
24
13,437,000
49,800
7,930
800/310/200/250/170/ISO/150
500/600/180/200/250/170/150/150
760
-------
Table V-15 (Continued)
SUMMARY OF DATA. FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE AND
ANALYSIS REPORTS FOR ONCE-THROUGH COOLING WATER SYSTEMS
\o
Pollutant
1742 Cadmium, Total (Dissolved)
Chromium, Total (Dissolved)
Copper, Total (Dissolved)
Lead, Total (Dissolved)
Nickel, Total (Dissolved)
Silver, Total (Dissolved)
Zinc, Total (Dissolved)
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Aluminum, Total
Barium, Total (Dissolved)
Boron, Total (Dissolved)
Calcium, Total (Dissolved)
Cobalt, Total
Manganese Total
Magnesium, Total (Dissolved)
Molybdenum, Total
Phenolics, 4AAP
Total Residual Chlorine
Sodium, Total (Dissolved)
Tin, Total
Titanium, Total
Iron, Total
Vanadium, Total (Dissolved)
Concentration (ppb)
Intake
40(5)
24/20(ND/30)*
21/20(ND/9)*
9/NK20(ND/90)*
17/ND<5(ND/40)*
(ND/10)*
ND/70(30/ND<60)*
340,000
100,000
10,000
2,000
60(30)
90(200)
51,000(44,000)
10
200
23,000(22,000)
9
6
21,000(20,000)
30
40
4,000
ND/ND<10(ND/20)*
Discharge
1,200,000
90,000
9,000
260
330/890/800/860
*These multiple results represent analyses by multiple analytical labs.
OValues in parentheses indicate dissolved fractions.
-------
Table V-15 (Continued)
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE AND
ANALYSIS REPORTS FOR ONCE-THROUGH COOLING WATER SYSTEMS
- Plant
Code Pollutant
2608 Benzene
Concentration (ppb)
2-Chloronaphthalene
Chloroform
1,1-Dichloroethylene
Ethylbenzene
Methylene Chloride
Bromoform
Phenol (GC/MS)
Butyl Benzyl Phthalate
Di-N-Butyl Phthalate
Toluene
Trichloroethylene
Antimony, Total
Arsenic, Total
Chromium, Total
Copper, Total
Mercury, Total
Selenium, Total
Zinc, Total
Total Dissolved Solids
Total Organic Carbon
Barium, Total
Calcium, Total
Manganese, Total
Intake
ND
MD/26*
ND
D < 10
7
3
13
7
1.2
< 2
< 60
ND
ND
229,000
6,000
10
39,600
53
Discharge
Chlorinated
30/70/100/50/ND/1QOO
DOO/ND
D<8/10/D<10/D<9/D<8/D<8
ND/10/ND/40/ND/D<10
ND/ND/ND/ND/ND/D<10
210/350/1Q/100/ND/370
ND/ND/ND/ND/ND/ND
ND/17*
120
10
ND/ND/ND/ND/ND/D<10
D<10/D<10/D<10/ND/D<10/ND
3
3
13
9
0.7
3
ND < 60
225,000
6,000
13
42,200
71
Dechlorinated
D<10/D<10/D<10/40/D<10/D<10
D<10/130/D<10
ND
D<6/4/D<10/D<5/D<10/D<6.5
D<6/D<3/10
ND/ND/ND/D<10/ND/ND/ND/ND/ND
ND/ND/D<10/D<10/ND/ND/ND/D<10/ND
106/190/240/40/100/20/20/140/50
ND/ND/D<10/ND/ND/ND/ND/ND/ND
ND/11*
ND
D < 10
ND/ND/D<10/D<10/ND/ND/ND
D<10/ND
ND/ND/ND/ND/ND/D<10/ND/ND/ND
5
6
12
11
0.1
ND
ND
222
6
64
000
000
11
42,200
59
*These multiple results represent analyses by multiple analytical labs.
()Values in parentheses indicate dissolved fractions*
-------
Table V-15 (Continued)
Plant
Code Pollutant
SUMMARI OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE AND
ANALYSIS REPORTS FOR ONCE-THROUGH COOLING WATER SYSTEMS
Concentration (ppb)
2608 Magnesium, Total
(Cont) Total Resdual Chlorine
Sodium, Total
Iron, Total
2603 Benzene
1,1,1-Triehloroethane
Chloroform
1,1-Dichloroethylene
Ethylbenzene
^ Methylene Chloride
Pentachlorophenol
Phenol (GC/MS)
Bis(2-ethylhexyl) Phthalate
Butyl Benzyl Phthalate
Di-N-Butyl Phthalate
Diethyl Phthalate
Tetrachlete ethylene
Trichloroethylene
Arsenic, Total
Chromium, Total
Copper, Total
Mercury, Total
Nickel, Total
Silver, Total
Zinc, Total
Total Dissolved Solids
Total Organic Carbon
*These multiple results represent analyses by multiple analytical labs.
Qvalues in parentheses indicate dissolved fractions.
Intake
13,100
D<15,000
248
D < 10
ND
D < 10
ND
ND
D < 10
ND
ND/9*
D < 10
D < 10
D < 10
50
D < 10
D < 10
ND < 2
10
22
0.2
8
ND < 1
88
292,000
9,000
Chlorinated
13,000
0/40/40/40
15,000
D < 10
ND
D < 10
ND
ND
20
D < 10
4/ND*
D < 10
ND
20
20
D"< 10
D < 10
ND < 2
13
23
0.1
ND < 5
ND < 1
68
271,000
6,000
Discharge
Dechlorinated
13,000
0/0/0/0
23,000
D < 10
D < 10
D < 10
D < 10
D < 10
35
ND
4/D < 10*
D < 10
ND
D < 10
D < 10
D < 10
D < 10
3
11
22
0.1
ND < 5
2
ND < 60 .
247,000
6,000
-------
Table V-15 (Continued)
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE AND
ANALYSIS REPORTS FOR ONCE-THROUGH COOLING WATER SYSTEMS
Plant
Code Pollutant
Concentration
2603 Aluminum, Total
(Cont) Barium, Total
Boron, Total
Calcium, Total
Manganese, Total
Magnesium, Total
Total Residual Chlorine
Sodium, Total
Tin, Total
Titanium, Total
vo Iron, Total
Free Residual Chlorine
2607 Benzene
Chloroform
1,1-Dichloroethylene
Methylene Chloride
Phenol (GC/MS)
Bis(2-ethylhexyl) Phthalate
Di-N-Butyl Phthalate
Toluene
Trichloroethylene
Arsenic. Total
Chromium, Total
Copper, Total
*These multiple results represent analyses by multiple analytical labs.
OValues in parentheses indicate dissolved fractions.
Intake
497
t 7
11
m < so
48,700
65
15,300
.
23,600
36
18
842
. — . —
20
ND
10
ND
ND/D<10*
D < 10
D < 10
D < 10
ND
5
7
14
Discharge
Chlorinated
445
140
45,300
61
13,900
D<30/200/240/270/300
20,700
ND < 5
ND < 15
715
40/140/10
D < 10
D < 10
ND
10
ND/D<10*
D < 10
ND
ND
D < 10
5
10
14
<•
Dechlorinated
689
53
44,900
65
14,000
D<30/D<30/D<30/1 10/D<30
18,300
ND < 5
20
921
20
ND
ND
10
ND/D<10*
D < 10
D < 10
D < 10
ND
4
7
14
-------
Table V-15 (Continued)
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE AND
ANALYSIS REPORTS FOR ONCE-THROUGH COOLING WATER SYSTEMS
Plant
Code Pollutant
Concentration (ppb)
o
o
2607 Selenium, Total
(Cont) Thallium, Total
.Zinc, Total
Total Dissolved Solids
Total Organic Carbon
Aluminum, Total
Barium, Total
Boron, Total
Calcium, Total
Manganese, Total
Magnesium, Total
Molybdenum, Total
Total Residual Chlorine
Sodium, Total
Titanium, Total
Iron, Total
5513 Benzene
Benzideae
1,1,1-Trichloroethane
Chloroform
1,2-Dlchlorobenzene
2,4-Dichlorophenol
Ethylbenzene
Methyl Chloride
Bis(2-ethylhexyl) Phthalate
Di-N-Butyl Phthalate
*These multiple results represent analyses by multiple analytical labs.
QValues in parentheses indicate dissolved fractions.
Intake
3.8
3
ND < 60
260,000
14,000
2,440
32
70
44,800
98
14,200 ;
ND < 5
20,500
51
2,560
A A
HU
ND
ND
ND
ND
ND
D < 10
50
D < 10
D < 10
Chlorinated
8.3
ND < 2
ND < 60
263,000
9,000
2,180
31
56
35,400
86
11,700
10
0/0/0/0/0/0
15,500
58
2,260
"""
ND/30/40
ND/D<10/ND
ND/20/10
ND/D<10
1./ND
ND
400/50/50
ND
10
Discharge
Deehlorinated
2.7
ND < 2
73
294,000
6,000
2,090
31
89
43,400
97
13,700
ND < 5
0/0/0/0/0/0
19,800
58
2,340
ND
ND
ND
ND
ND
ND
10
ND
ND
-------
Table V-15 (Continued)
Plant
Code Pollutant
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE AND
ANALYSIS REPORTS FOR ONCE-THROUGH COOLING WATER SYSTEMS
Concentration (ppb)
5513 Toluene
(Cont) Trichloroethylene
Ant imony, Total
Arsenic, Total
Chromium, Total
Copper, Total
Cyanide, Total
Lead, Total
Mercury, Total
Selenium, Total
Silver, Total
COD
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Aluminum, Total
Barium, Total
Boron, Total
Calcium
Cobalt, Total
Manganese, Total
Magnesium, Total
Molybdenum, Total
Phenolics, 4AAP
Sodium, Total
Tin, Total
Titanium, Total
Iron, Total
Total Solids
*These multiple results represent analyses by multiple analytical labs,
OValues in parentheses indicate dissolved fractions.
Intake
ND
ND
10
4
19
8
. 10
ND < 20
1
3
m < i
35,000
545,000
10,000
13,000
283
24
83
84
D < 5
66
33,000
13
49,000
30
ND < 15
675
AIO Ann
Chlorinated
ND/ND/D<10
ND/ND/K10
10
ND < 10
25
11
ND < 5
34
0.8
ND <• 2
3
33,000
526,000
10,000
14,000
245
18
51
73
D < 5
63
30,200
16
15
35,000
ND < 5
19
537
Discharge
Dechlorlnated
ND
ND
9
4
24
10
ND < 5
41
1.9
3
ND < 1
33,000
506,000
10,000
14,000
289
21;
50
76
D < 5
62
30,900
14
19
39,700
ND < 5
18
646
-------
The jdata in Table V-15 indicate that there were net increases in all
of the following compounds: total dissolved solids, total suspended
solid,s, total organic carbon, total, residual chlorine, free available
chlorjine, 2,4-dichlorophenol, 1,2-dichlorobenzene, phenol ics,
chroniium, copper, lead, mercury, silver, iron, arsenic, zinc, barium,
calcium, manganese, sodium, methylene chloride, aluminum, boron and
titanium. However, the net increase was greater than 10 ppb only for
l,2-c|ichlorobenzene, total phenolics, lead, zinc, and methylene
chloride. Only for 1,2-dichlorobenzene and total phenolics were the
increases greater than 25 ppb, and in one case an increase of slightly
more then 250 ppb was observed for total phenolics.
Recifculating Cooling Water Systems :
Four powerplants with cooling towers were sampled at intake and
discharge points during the screening phase of the sampling program.
The results of the priority pollutants analyses of these samples are
presented for each plant in table V-16. The metal, organic (other
than I the volatile organics), and asbestos samples were 24-hour
composites.
Eight powerplants with cooling towers were sampled at intake and
discharge points during the verification sampling program. As noted
in table V-2, plants using fresh, salt or brackish water included.
The results of the verification sampling program for cooling tower
blowdown are presented in table V-17.
The data presented in tables V-16 and V-17 indicate that there was a
net increase from the influent concentration to the effluent
concentration for the following compounds: trichlorofluoromethane,
bromoform, chlorodibromomethane, bis(2-ethylhexyl) phthalate,
antimony, arsenic, cadmium, chromium, mercury, nickel, selenium,
silver, thallium, benzene, tetrachloroethylene, toluene, copper,
cyanide, lead, zinc, chloroform, phenol, asbestos, total dissolved
solids, total suspended solids, total organic carbon, total residual
chlorine, 1,2-dichlorobenzene, 2,4-dichlorophenol, boron, calcium,
magnesium, molybdenum, total phenolics, sodium, tin, vanadium, cobalt,
iron," chloride, 2, 4, 6-trichlorophenol, and pentachlorophenol. It must
be recognized, however, that recirculating cooling systems tend to
concentrate the dissolved solids present in the make-up water and,
thus/ a blowdown stream with many different compounds showing con-
centration increases is to be expected. Of the priority pollutants
detected as net discharges, the concentration increase was greater
than- 10 ppb only for bis(2-ethylhexyl) phthalate, cadmium, chromium,
nickel, selenium, silver, toluene, copper, cyanide, lead, zinc,
phenol, 1,2-dichlorobenzene, total phenolics, and 2,4,6,-trichloro-
phenol. Net increases of greater than 25 ppb were observed for all of
the 'following: bis (2-ethylhexyl) phthalate, cadmium, chromium,
nickel, selenium, silver, toluene, copper, cyanide, lead, zinc,
1,2-dichlorobenzene, and 2,4,6-trichlorophenol. The net concentration
increase exceeded 100 ppb only for bis (2-ethylhexyl) phthalate,
cadmjLum, chromium, copper, cyanide, lead, and zinc.
102
-------
fable V-16
-• %i ' - -
RESULTS OF THE SCREENING PHASE OF THE
SAMPLING PROGRAM FOR COOLING TOWER SLOWDOWN
Plant 3404
Pollutant
Benzene
Chloroform
1,4-Dichlorobenzene
1 ,1-Dichloroethylene
Methylene Chloride
Trichlorofluoromethane
Brotaoform
Chlorodibromomethane
Phenol
Bis(2-Ethylhexyl) Phthalate
Di-N-Butyl Phthalate
Toluene
Antimony, Total
Arsenic, Total.
Cadmium, Total
Chromium, Total
Copper, Total
Lead, Total
Mercury, Total
Nickel, Total
Selenium, Total
Silver, Total
Thallium, Total
Cone et^tr at ion ( ppb )
Intake
1
3/1
ND < 1
1/1
20/1
ND < 1
ND<1/ND<1
ND<1/ND<1
ND<1/36
11
4
3/3
11
<5
15
16
25
'. • 5
.0.34
21
55
40
<5
Discharge ,
1
1/1
1
2/ND<1
10/4
1
4/4
3/3
1/<10
62
ND < 1
6/2
14
8
40
23
13
- , <5 - '
0.58
29
87
64
9
103
-------
Table V-16 (Continued)
RESULTS OF THE SCREENING PHASE OF THE
SAMPLING PROGRAM FOR COOLING TOWER SLOWDOWN
Plant 0631
Pollutant
Methylene Chloride
Phenol
Toluene
Benzene
Chloroform
Tetraehloroethylene
Toluene
Antimony, Total
Arsenic, Total
Cadmium, Total
Chromium, Total
Copper, Total
Cyanide, Total
Lead, Total
Mercury, Total
Nickel, Total
Selenium, Total
Silver, Total
Zinc, Total
Concentration (ppb)
IntakeDischarge
20.6
3.9/20
24.4
ND < 1
5.7
ND < 1
47.8
<5
<5
10
37
25
130
<5
0.41
8
<5
9
41
ND
1.5.
34/40
21
1 ,
< 1
1
115
6
13
25
75
150
360
17
0,
100
23
32
67
0
91
104
-------
Table V-16 (Continued)
l RESULT^ OF THE SCREENING PHASE OF THE
SAMPLING PROGRAM FOR COOLING TOWER SLOWDOWN
Plant 2414
Pollutant
Benzene
1,2-Dichloroethane
1,1,1-Trichloroethane
Chloroform
1,4-Dichlorobenzene
Methylene Chloride
Phenol
Bis(2-Ethylhe3tyl) Phthalate
Diethyl Phthalate
Toluene
Cis 1,2-Dichloroethylene
Ethylbenzene
Antimony, Total
Arsenic, Total
Asbestos (fibers/liter)
Chromium, Total
Copper, Total
Cyanide, Total
Lead, Total
Mercury, Total
Nickel, Total
Selenium, Total
Silver, Total
Thallium, Total
Concentration (ppb)
intake
2/1
2/1
1/1
10/
28
.3
2
1
2
1
10
105
5
15
1
<5
5
,400
<5
21
<20
7
0.88
8
15
45
6
Discharge
2/1
ND < 1
ND < 1
3 ;
ND <1
3/ND<1
25
262 '
ND < 1
7/10
20/ND<1
1
7
9
147,000
11 .
70
50
8
1 .02
58
22
65 .
5
105
-------
Table V-16 (Continued)
RESULTS OF THE SCREENING PHASE OF THE
SAMPLING PROGRAM FOR COOLING TOWER SLOWDOWN
Plant 4836
Pollutant
Chloroform
1,1-Dichloroethylene
Methylene Chloride
Bromoform
Trichlorofluoromethane
Ghlorodibromoform
Phenol
Bis(2-Ethylhexyl) Phthalate
Di-N-Butyl Phthalate
Diethyl Phthalate
Tetrachloroethylene
Toluene
1,4-Dichlorobenzene
Bromodichloroethylene
Antimony, Total
Chromium, Total
Copper, Total
Cyanide, Total
Mercury, Total
Nickel, Total
Selenium, Total
Zinc, Total
Concentration (ppb)
Intake
9/6
ND<1/
49/8
ND <
1/1
ND <
:
1/2
6/3
M
1
1
3
1
1
2
1
2
<5
6
8
62
0,15
6
<5
23
Discharge
ND< 1/1
1/1
4/4
ND < 1
1
ND<1/ND<1
1
1
ND < 1
ND < 1
ND<1/ND<1
3/3
ND < 1
ND < 1
10
11
95
75
0.29
10
8
19
106
-------
fable V-17
SUMMARY OF RESULTS OF VERIFICATION PROGRAM FOR RECIRCULATING COOLING WATER SYSTEMS
Pollutant
Concentration (ppb)
o
•xj
2718 2,4-Dichlorophenol
Pentachlorophenol
Cadmium, Total
Chromium, Total
Copper, Total
Lead, Total
Nickel, Total
Thallium, Total
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Barium, Total
Boron, Total
Calcium, Total
Cobalt, Total
Manganese, Total
Magnesium, Total
Molybdenum, Total
Phenolics, 4AAP
Total Residual Chlorine
Sodium, Total
Tin, Total
Titanium
Iron, Total
1,1,2,2-Te trachloroe thane
*These multiple results represent analyses by multiple analytical labs,
()Values in parentheses Indicate dissolved fractions.
Intake
3
4
8
ND/400*
14/10
ND < 20
ND/200*
20
370,000
2,000
9,000
100
80
59,000
10
60
33,000
20
— . —
ND < 10
ND < 15,000
30
20
2,000
ND < 5
Discharge
ND
ND
4
ND/300*
53/20
40
ND/124*
20
27,000,000
17,000
46,000
100
ND < 50
35,000
10
60
20,000
20
ND < 5
350/280/90/10
ND < 15,000
30
20
1,000
-------
Table V-17 (Continued)
SUMMARY OF RESULTS OF VERIFICATION PROGRAM FOR RECIRCULATING COOLING WATER SYSTEMS
Plant
Code
1245
i-1
o
00
Pollutant
1,2-Dichlorobenzene
2,4-Dichlorophenol
Pentachlorophenol
Cadmium, Total
Chromium, Total
Copper, Total (Dissolved)
Nickel, Total
Silver, Total
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Boron, Total
Calcium, Total
Manganese, Total
Magnesium, Total
Molybdenum, Total
Phenolics, 4AAP
Total Residual Chlorine
Sodium, Total
Tin, Total
Vanadium, Total
Concentration (ppb)
Intake
ND
3
ND < 2
83/20*
12/ND<6*
ND/ND<5*
ND < 1
900,000
2,000
22,000
500
53,000
8
22,000
ND < 5
7
1,170
170,000
ND < 5
ND < 3
Discharge
26
8
4
5
55/40*
70/30*
ND/10*
2
2,240,000
4,000
76,000
2,000
140,000
ND < 3
48,000
40
20
0/0/0/0/0
350,000
30
10
*These multiple results represent analyses by multiple analytical labs.
QValues in parentheses indicate dissolved fractions.
-------
Table V-17 (Continued)
SUMMARY OF RESULTS OF VERIFICATION PROGRAM FOR RECIRCULATING COOLING WATER SYSTEMS
1226
i-1
o
Pollutant
Chloroform
Bromoform
Dlchlorobromomethane
Chlorodibromomethane
Ant imony, Total
Arsenic, Total
Cadmium, Total
Chromium, Total
Copper, Total (Dissolved)
Lead, Total (Dissolved)
Mercury, Total
Nickel, Total (Dissolved)
Silver, Total
Zinc, Total (Dissolved)
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Aluminum, Total (Dissolved)
Barium, Total (Dissolved)
Boron, Total
Calcium, Total (Dissolved)
Cobalt, Total
Manganese, Total (Dissolved)
Magnesium, Total (Dissolved)
Phenolics, 4AAP
Total Residual Chlorine
Sodium, Total (Dissolved)
Concentration (ppb)
Intake
Discharge
ND/7*
ND/3*
2.1/ND<2*
ND/7/7*
10/12/10*(10)
12/10/ND<20*(7/ND/20)*
ND<1/0.5*
27/1.5/ND<5*(29/ND*)
ND/1.3/ND<1*
ND/9/70*(50/ND<60)*
190,000
14,000
10,000
700(100)
20(20)
ND < 50
6,900(D<5000)
7
200(200)
4,500(5000)
12
33,000(36,000)
D < 1
154
8.
58
7
ND/4*
1.8/ND<2*
28/5/20*
47/50*
3/ND<20*
0.2
6/6/ND<5*
0.7/ND<1*
50/26/ND<60*
1,050,000
8,000
11,000
400
20
60
6,900
8
100
4,900
8
D<10/D<10/D<10/D<10/D<10/D<10/90/D<10
210,000
*These multiple results represent analyses by multiple analytical labs.
OValues in parentheses indicate dissolved fractions.
-------
Table V-17 (Continued)
SUMMARY Of RESULTS OF VERIFICATION PROGRAM FOR RECIRCULAIING COOLING WATER SYSTEMS
Plant
Code
Pollutant
Concentration (ppb)
1226 Titanium, Total
(Cont'd) Iron, Total (Dissolved)
Vanadium, Total
Lead (Dissolved)
4251 1,2-Dichlorobenzene
2,4-Dichlorophenol
Cadmium, Total
Chromium, Total
Copper, Total
,_, Lead, Total
g Nickel, Total
Zinc, Total
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Barium, Total
Boron, Total
Calcium, Total
Cobalt, Total
Manganese, Total
Magnesium, Total
Molybdenum, Total
Phenolics, 4AAP
Total Residual Chlorine
Sodium, Total
Iron, Total
Intake
20
2,000(1,000)
ND/40/ND<10*
(7/ND<20*)
ND
11
9
42/500*
55/20*
30
24/200*
340/ND<60*
227,000
10,000
34,000
40
60
29,000
10
200
7,600
20
16
D < 10
17,000
2,000
Discharge
20
3,000
27/ND<10
20
ND
m < 2
10/10*
81/40*
ND < 20
42/10*
40/OTK60*
430,000
53,000
15,000
70
ND/53,000*
ND < 5
70
8,900
ND < 5
8
100/4100/6500/6200/5200/4300/3950/
3400/2800/2500/2000/1550/1300/750
52,000
300
*These multiple results represent analyses by multiple analytical labs.
()Values in parentheses indicate dissolved fractions.
-------
Table V-17 (Continued)
SUMMARY OF RESULTS OF VERIFICATION PROGRAM FOR RECIRCULATING COOLING WATER SYSTEMS
Plant
Code
3404
Pollutant
1,2-Dichlorobenzene
2,4-Dichlorophenol
Pentachlorophenol
Cadmium, Total
Chromium, Total
Copper, Total
Lead, Total
Nickel, Total
Silver, Total
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Aluminum, Total
Boron, Total
Calcium, Total
Cobalt, Total
Manganese, Total
Molybdenum, Total
Phenolics, 4AAP
Totai Residual Chlorine
Sodium, Total
Tin, Total
Titanium, Total
Iron, Total
Vanadium, Total
Concentration (ppb)
Intake
18
12
12
100
78/800*
33/ND<60*
500
34/100*
40
26,000,000
110,000
26,000
2,000
4,000
340,000
ND < 50
200
80 . "
5
ND< 1 0/ND< 1 0/ND< 1 0/ND< 1 0
6,000,000
300
200
4,000
200
Discharge
ND
8
4
200
110/1000*
24/60
800
78/200*
80
34,000,000
90,000
9,000
2,000
4,000
460,000
80
100
100
230/190/390/170
7,000,000
500
200
4,000
200
*These multiple results represent analyses by multiple analytical labs.
QValues in parentheses indicate dissolved fractions.
-------
Table V-17 (Continued)
SUMMARY OF RESULTS OF VERIFICATION PROGRAM FOR RECIRCULATING COOLING WATER SYSTEMS
Plant
Code
5409
Pollutant
Concentration (ppb)
Benzene
Carbon Tetrachloride
Chloroform
1,2-Dichlotobenzene
Dichlorobromomethane
Chlorodibromoraethane
Toluene
Trichloroethylene
Cadmium, Total
Chromium, Total
P Copper, Total (Dissolved)
*° Cyanide, Total
Lead, Total (Dissolved)
Mercury, Total
Nickel, Total
Selenium, Total
Silver, Total
Thallium, Total
Zinc, Total (Dissolved)
Total Suspended Solids
Total Organic Carbon
Chloride
Vanadium, Total
1,3 and 1,4-Dichlorobenzene
*These multiple results represent analyses by multiple analytical labs.
()Values in parentheses indicate dissolved fractions.
Intake
D < 1
ND < 2
15
ND < 0
ND < 1
20
2.4
1.4
5.3
-
-
2
4
1.4
27
,000
8
.2
1.7
2
1.6
15
5
,000
_
13
2.4
Discharge
1.5
__^__
2.4
2.6
D < 1
4
1
37
3,800(620)
5
130(70)
1
4
ND < 2
14
8
290(61)
460,000
21,000
110,000
17
•
-------
Table V-17 (Continued)
SUMMARY OF RESULTS OF VERIFICATION PROGRAM FOR RECIRCOLAfING COOLING WAfER SYSTEMS
Pollutant:
Concentration (ppb)
5604 Benzene
Toluene
Antimony, Total
Arsenic, Total
Chromium, Total
Copper, total
Cyanide, Total
Lead, Total
Nickel, Total
Selenium, Total
i Silver, Total
Zinc, Total
Total Suspended Solids
Total Organic Carbon *
Chloride
Vanadium, Total
*These multiple results represent analyses by multiple analytical labs.
()Values in parentheses indicate dissolved fractions.
latake
ND
ND
ND
ND
-
1.2
9.1
4
< 1
< 2
700
4
6
< 0.5
2
< 3
53
5,500
14,000
11
Discharge
D < 1 •""•'"•'
23
5
7
2
180
.' .3
ND < 3
6
ND.< 2
3
780
42,000
14,000
54,000
24
-------
Table V-17 (Continued)
SUMMARY OF RESULTS OF VERIFICATION PROGRAM FOR RECIRCULATIBC COOLING WATER SYSTEMS
Plant
Code
.4602
Pollutant
2,4,6-Tr ichlor ophenol
Pentachlorophenol
Cadmium, Total
Chromium, Total
Copper, Total
Lead, Total
Nickel, Total
Silver, Total
Zinc, Total
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Barium, Total
Boron, Total
Calcium, Total
Cobalt, Total
Manganese, Total
Magnesium, Total
Molybdenum, Total
Phenolics, 4MP
Total Residual Chlorine
Sodium, Total
Tin, Total
Titanium, Total
Iron, Total
Vanadium, Total
Concentration (ppb)
Intake
ND
ND
ND < 20
73/100*
21/50*
30
98/ND<5*
2
NB/70*
190,000
2,000
D < 1000
300
300
260,000
8
90
100,000
20
D < 5
D < 10
95,000
60
30
1,000
20
Discharge
35
4
5
130/400*
62/400*
ND < 30
60/200*
ND < 1
210/200*
880,000
2,000
9,000
200
60
110,000
10
50
57,000
60
D < 5
7340/4730/190/50
33,000
60
ND < 20
2,000
20
*These multiple results represent analyses by multiple analytical labs.
QValues in parentheses indicate dissolved fractions.
-------
Additional Data Sources
Another source of useful data is a study on the chlorinationiof a
fresh water once-through cooling system that found that chloroform
levels in the outlet from the condenser during periods of chlorine
addition ranged between 1.4 and 8.7 ppb (47). The mean chloroform
concentration, in the condenser outlet during chlorination was S.Ojppb.
The intake in this same study, had chloroform levels consistently below
1.0 ppb with the exception of one sample point at 1.2 ppb. ,, f
Samples were also analyzed for dichlorobromomethane in this.same study
(47). Condenser outlet dichlorobromomethane levels ranged from 049 to
4.6 ppb during .the period ,of chlorine addition. The ,'mean
dichlorobromomethane level was 2.0 ppb. Intake water ' had
dichloromethane levels consistently below 0.2 ppb.
Analysis was also done for dibromochloromethane (47). Condenser
outlet dibromochloromethane levels ranged from less than 0.2 ppo to
1.5 ppb during the period of chlorine addition. The 'jmean
dibromochloromethane level was 0.. 77 ppb but in three samples the level
of dibromochloromethane could not be quantified; these samples -'were
not used in calculating the mean. Intake water was consistently below
0.2 ppb dibromochloromethane. -.. • • I '
Summary of the Results of Cooling Water Sampling and Data Collecting
Efforts ~ •• •
I
An examination of all the available data, including screening,
verification, surveillance and analysis, and literature data, lea<3s to
several major conclusions. First, net discharges of metals other I than
chromium and zinc are the result of- corrosion of metal surfaces within
the cooling water system. Net discharges from once-through systems
are typically less than 20 ppb. Net discharges from recirculating
cooling systems may be higher because of the concentrating effect
these systems have on dissolved solids. Net discharges of chromium
and zinc from recirculating systems may be as high as 1,000 ppb'Zinc
and 200 ppb chromium as the result of the use of corrosion control
additives(13). |
Second, the organic pollutants that were detected in the sampling
efforts may result from several sources. Methylene chloride may be a
product of chlorination or, since it is a common lab solvent, may be
an analytical error. Bis (2-ethylhexyl) phthalate is probably the
result of the loss of plasticizers from plastic sampling tubes or
bottles. 2,4-dichlorophenol, 1,2-dichlorobenzene, bromoform, chloro-
dibromomethane, and chloroform all may result from cooling tyater
chlorination. Net discharges of these compounds were always at or
below 30 ppb, often only a few ppb. The concentration scale up effect
of recirculating cooling systems may account for increases in some of
the organics. The use of non-oxidizing biocides may explaint' the
presence of compounds like phenol, benzene, toluene, 1,2-dichloro-
benzene, 2,4,6-trichlorophenol and pentachlorophenol (13,17). '
115
-------
A third major finding was a net dscharge of asbestos in the cooling
tower blowdown of plant 2414. Since asbestos was also present in the
make-up water, it is not clear whether fill erosion is occuring. The
introduction of asbestos into cooling tower blo.wdown from fill erosion
has already been demonstrated by the data presented in table V-13.
Finally, net discharges of total residual chlorine were observed in
both once-through and recirculating systems. Net discharges as high
as 7,100 pph were observed.
ASH HANDLING
Steam electric powerplants using oil or coal as a fuel produce ash as
a waste product of combustion. The total ash product is the
combination of bottom ash and fly ash. Bottom ash is the residue
which accumulates on the furnace bottom, and fly ash is the lighter
material which is carried over in the flue gas stream. In coal-burning
boilers, some of the fly ash or carryover ash settles in the
economizer section of the boiler. This ash is called economizer ash
and is typically the larger particles of the fly ash.
The ash composition of oil, on a weight percent basis, is much lower
than that of coal. Oil ash seldom exceeds 0.2 percent whereas coal
ash comprises from 3 to 30 percent of the coal. As such, the presence
of ash is an extremely important consideration in the design of a
coal-fired boiler and, to a lesser extent, an oil-fired boiler.
Improper design could lead to accumulation of ash deposits on furnace
walls and tubes, leading to reduced heat transfer, increased pressure
drop, and corrosion.
Ash handling or transport is the conveyance of the accumulated waste
products to a disposal system. The method of conveyance may be either
wet (sluicing) or dry (pneumatic). Dry handling systems are more
typical for fly ash than bottom ash. The method of disposal for a dry
ash is commonly by landfill but the ash can also be sold as a by-
product for a variety of uses such as an ingredient for road pavement
or for portland cement (alkaline ashes). Ash from oil-fired-units is
often sold for the recovery of vanadium.
Wet ash handling systems produce wastewaters which are currently
either discharged as blowdown from recycle systems or discharged
directly to receiving streams in a once-through manner. Statistical
analyses of fly ash and bottom ash wastewater flow rates reported in
308 responses from the industry are presented in tables V-18 and V-19.
The chemical characteristics of ash handling wastewater are basically
a function of the inlet or makeup water, composition of the fuel
burned, and the composition of other wastewaters discharged into the
ash settling ponds. These characteristics are discussed in this
section.
116
-------
Table V-18
Variable
Fuel: Coal*
Flow: GPD/plant 167
GPD/MW 166
FLY ASH POND OVERFLOW
(308 Questionnaire)
Number
of
Plants Mean Value
Minimum
Standard Deviation Value Maximum Value
2,610,724.6 3,397,528.7
3,807.976 3,608.152
0.00 23,000,000
0.00 16,386.91
Fuel: Gas*
Flow: GPD/plant 21
GPD/MW 21
Flow: Oil*
Flow: GPD/plant 47
GPD/MW 47
322,170.0
1,899.28
764,538.7
3,026.676
487,996.2 1,607,619.2
828.552 1,652.856
0.00
0.00
0.00
0.00
3,250,000
11,535,049
9,750,000
7,485.76
*Fuel designations are determined by the fuel which contributes the most Btu for power
generation for the year 1975.
-------
Table V-19
Variable
Fuel; Coal*
BOTTOM ASH POND OVERFLOW
(308 Questionnaire)
Number
of lliriimum
Plants Mean Value Standard Deviation Value
Flow; GPD/plant 219 2,600,998.7 5,072,587.5
GPD/MW 218 3,880.983 5,147.284
0.00
0.00
Maximum Value
33,600,000
38,333.33
06
Fuel: Gas*
Flow: GPD/plant 25
GPD/MW 25
Flow. Oil*
Flow; GPD/plant 40
GPD/MW 40
417,345.2 1,026,066.7
1,804.65 3,229.089
322,913.6
622.696
907,839.3
1,698.706
0.00 4,020,000
0.00 11,535.049
0.00 4,900,000
0.00 9,902.53
*Fuel designations are determined by the fuel which contributes the most Btu for power
generation for the year 1975.
-------
Fly Ash From Oil-Fired Plants
The ash from fuel oil combustion usually is in the form of fly ash.
The relatively small quantity of ash (compared to coal) is capable of
causing severe problems of external deposits and corrosion in boilers.
The many elements which may appear in oil ash deposits include
vanadium, sodium, and sulfur. Compounds containing these elements are
found in almost every deposit in boilers fired by residual fuel oil
and often constitute the major portion of these deposits.
Origin of Crude Oil Ash
Some of the ash-forming constituents in the crude oil had their origin
in animal and vegetable matter from which the oil was derived. The
remainder is extraneous material resulting from contact of the crude
oil with rock structures,and salt brines pr picked up during refining
processes, storage, and transportation.
In general, the ash content increases with increasing asphaltic
constituents in which the sulfur acts largely as a bridge between
aromatic rings. Elemental sulfur and hydrogen sulfide have been
identified in crude oil. 'Simpler sulfur compounds, including thio-
esters, disulfides, thiophenes, and mercaptans, are found in the
distillates of crude oil.
Vanadium, iron, sodium, nickel, and calcium in fuel oil are common in
rock strata, but elements including vanadium, nickel, zinc, and copper
are believed to come from organic matter from which the petroleum was
created. Vanadium and nickel are known to be present in organo-
metallic compounds known as porphyrins which are characteristic of
certain forms of animal life. Table V-20 summarizes the amounts of
vanadium, nickel, and sodium present in residual fuel oils from
various crudes.
Crude oil, as such, is not normally used as a fuel but is further
processed to yield a wide range of more valuable products. For
example, in a modern United States refinery, the average product
yield, as a percentage of total throughput, is given in table V-21.
Virtually all metallic compounds and a large part of the sulfur.
compounds are concentrated in the distillation residue, as illustrated
for sulfur in table V-22. Where low-sulfur residual fuel oils are
required, the oil is obtained by blending with suitable stocks,
including both heavy distillates and distillation from low-sulfur
crudes. This procedure is used occasionally if a residual fuel oil
must meet specifications such as vanadium, or ash content.
Release of Ash During Combustion
Residual fuel oil is preheated and atomized to provide enough reactive
surface to burn completely within the boiler furnace. The atomized
fuel oil burns in two stages. In the first stage, the volatile
portion burns and leaves a porous coke residue; and, in the second
'stage, the coke residue burns. In general, the rate of combustion of
119
-------
Table V-20
VANADIUM, NICKEL, AND SODIUM CONTENT OF
RESIDUAL FUEL OIL (18)
(parts per million by weight)
Source of
Crude Oil
Africa
1
2
Middle East
3
4
5
United States
6
7
8
Venezuela
9
10
11
12
13
Vanadium
5.5
1
7
173
47
13
6
11
«».**
57
380
113
93
Nickel
5
5
«w» <*•
51
10
— —
2.5
_.
6
13
60
32
-_
Sodium
22
--.
1
_ -
8
350
120
84
480
72
70
49
38
12.0,
-------
Table V-21
AVERAGE PRODUCT YIELD OF A MODERN
UNITED STATES REFINERY (18)
Product: - Percentage of Total Throughput
Gasoline 44.4
Lube oil fraction 16.4
Jet fuel 6.2
Kerosine 2.9
Distillates 22.5
Residual fuel 7.6
121
-------
Table V-22
SULFUR CONTENT IN FRACTIONS OF KUWAIT CRUDE OIL (18)
Distillation Range Total Sulfur
Fraction ' (°F) (% by Weight)
Crude Oil — 2.55
Gasoline 124-253 0.05
Light naphtha 257-300 0.05
Heavy naphtha 307-387 0.11
Kerosene 405-460 0.45
Light gas oil 477-516 0.85
Heavy gas oil 538-583 1.15
Residual oil 588-928 3.70
122
-------
tfce" coke residue is inversely proportional to the square of its
diameter, which, in turn, is related to the droplet diameter. Thus,
small fuel droplets give rise to coke residues which burn very
rapidly, and the ash-forming constituents are exposed to the highest
temperatures in the flame envelope. The ash-forming droplets are
heated more slowly, partly in association with carbon. Release of the
ash from these residues is determined by the rate of oxidation of the
carbon (18).
During combustion, the organic vanadium compounds in the residual fuel
oil thermally decompose and oxidize in the gas stream to V203, V204
and finally V?0S. Although complete oxidation may not occur and there
may be some dissociation, a large part of the vanadium originally
present in the oil exists as vapor phase V20S in the flue gas. The
sodium, usually present as a chloride in the oil, vaporizes and reacts
with sulfur oxides either in the gas stream or after deposition on
tube surfaces. Subsequently, reactions take place between the vana-
dium and sodium compounds with the formation of complex vanadates
which have melting ppints lower than those of the parent compounds.
An example is shown in equation 9. The melting point of each compound
is given below as well as the'formula for the compound.
Na2SQ* + V20S 2 2NaVO3 + S03 (9)
(1625 F) (1275 F) :(1165 F)
Excess vanadium or sodium in the ash deposit, above that necessary for
the formation of the sodium vanadates (or vanadyl vanadates), may be
present as V20S and Na2S04, respectively (18).
The sulfur in residual fuel is progressively released during
combustion and is promptly oxidized to sulfur dioxide (SO2). A small
amount of sulfur dioxide is further oxidized to SO3 by a small amount
of atomic oxygen present in the hottest part of the flame. Also,
catalytic oxidation of S0? to SO3 may occur as the flue gases pass
over vanadium rich ash deposits on high-temperature superheater tubes
and refractories (18).
Characteristics of Fuel Oil Ash
With respect to fuel oil ash characteristics, sodium and vanadium are
the most significant elements in fuel oil because they can form
complex compounds having low melting temperatures, 480 to 1250 F, as
shown in table V-23. Such temperatures fall within the range of tube-
metal temperatures generally encountered in furnace and superheater
tube banks of many oil-fired boilers. Because of its complex chemical
composition, fuel-oil ash seldom has a single sharp melting point, but
rather softens and melts over a wide temperature range (18). Oil ash
(especially from plants using Venezuelan and certain Middle Eastern
oil) can contain significant amounts of nickel.
123
-------
Table V-23
MELTING POINTS OF SOME OIL/ASH CONSTITUENTS (18)
Compound
Aluminum oxide ,
Aluminimu sulfate,
Calcium oxide, CaO
Calcium sulfate, CaS04
Ferric oxide , Fe203
Ferric sulfate, Fex (80^)3
Nickel oxide, NiO
Nickel sulfate, NiS04
Silicon dioxide,
Sodium sulfate,
Sodium bisulfate, NaHS04
Sodium pyrosulfate,
Sodium ferric sulfate,
Vanadium trioxide, ¥203
Vanadium tetroxide,
Vanadium pentoxide,
Sodium metavanadate,
Sodium pyrovanadate,
Sodium orthovanadate,
Sodium vanadylvanadates , Na20.V204.V205
Melting Point
(°F)
3720
1420*
4662
2640
2850
895
3795
1545*
3130
1625
480*
750*
1000
3580
3580
1275
1165
1185
1560
1160
995
*Decomposes at a temperature around the melting point.
124
-------
Ash From Coal-Fired Plants
Coal Ash Formation
More than 90 percent of the coal currently used by electric utilities
is burned in pulverized coal boilers. In such boilers, 65 to 80
percent of the ash is produced in the form of fly ash, which is
carried out of the combustor in the flue .gases and is separated from
these gases by electrostatic precipitators and/or mechanical
collectors. The remainder of the ash drops to the bottom of the
furnace as bottom ash or slag. The amounts of each type of ash
produced in the United States during several recent years are listed
in table V--24. The percentage of ash collected as fly ash has risen
from 65 percent in 1971 to 71 percent in 1975.
The ash residue resulting from the combustion of coal is primarily
derived from the inorganic matter in the coal. Table V-25 provides a
breakdown of several of the major ash constituents for different ranks
of coal. The overall percent ash in the coal varies from 3 to
approximately 30 percent. These major ash components can vary widely
in concentrations within a particular rank as well as between ranks.
Relatively significant concentrations of trace elements are also found
in the coal ash. Many of these elements, are listed in table V-26 for
various ranks of coal. These elements can range from a barely
detectable limit to almost 14,000 ppm as the maximum measured for
barium in some lignites and subbituminous coals.
During the combustion of coal, the products formed are partitioned
into four categories: bottom ash, economizer ash, fly ash, and
vapors. The bottom ash is that part of the residue which is fused
into particles heavy enough to drop out of the furnace gas stream (air
and combustion gases). These particles are collected in the bottom of
the furnace. The economizer ash particles are sized approximately
between those of bottom and fly ash. This ash is collected in
economizer hoppers just beyond the boiler flue gas pass. The fly ash
is that part of the ash which is entrained in the combustion gas
leaving the boiler. While most of the fly ash is collected in
mechanical collectors, baghouses, or electrostatic precipitators, a
small quantity of this material may pass through the collectors and be
discharged into the atmosphere. The vapor is that part of the coal
material which is volatilized during combustion. Some of these vapors
are discharged into the atmosphere; others are condensed onto the
surface of fly ash particles and may be collected in one of the fly
ash collectors. Certain of the trace elements are more volatile than
others. The more volatile elements, . e.g., mercury, fluorine,
thallium, and antimony, will have a strong tendency to vaporize and
perhaps condense on the fly ash particles. Some of the vapors may
also be trapped inside larger sized bottom ash particles resulting in
condensation there as well.
The distribution of the ash between the bottom ash and fly ash
fractions is a function of the boiler type (firing method), the type
of coal (ash fusion temperature), and the type of boiler bottom (wet
125
-------
Table V-24
MEGATONS OF COAL ASH COLLECTED IN THE UNITED STATES, (19)
Type 1971 1973 '""1974 1975 1980* 1985**
Fly ash 27.7 34.6 40.4 42.3
Bottom ash 10.1 10.7 14.3 13.1
Boiler slag 5.0 4.0 4.8 4.6
Total 42.8 49.3 59.5 60.0 75.0 120.0
Coal consumed - - 390 403
Calculated
average ash
content - - 15.3% 14.9% - -
*Projection by R. E, Morrison, American Electric Services Co.
**Projaction based on expected doubling in coal-fired power
generation, 1975 to 1985.
126
-------
Table V-25
VARIATIONS IN COAL ASH COMPOSITION WITH RANK (19)
Component Rank . .
Anthracite Bituminous Subbittiminous Lignite
Si02 48-68 7-68 17-58 6-40
Al203 25-44 4-39 4-35 4-26
F62CJ3 2-10 2-44 3-19 1-34
Ti02 1-2 0.5-4 0.6-2 0-0.8
CaO 0.2-4 0.7-36 '2.2-52 12.4-52
MgO 0.2-1 0.1-4 0.5-8 2.8-14
Na20 - 0.2-3 - 0.2-28
KaO - 0.2-4 - 0.1-1.3
S03 0.1-1 0.1-35 3-16 8.3-32
127
-------
Table V-26
RANGE IN AMOUNT OF TRACE ELEMENTS PRESENT IN COAL ASHES (19)
(ppm)
Anthracites
High volatile bituminous
Element
Ag
B
Ba
Be
Co
Cr
Cu
Ga
Ge
La
Mh
Ni
Pb
Sc
Sn
Sr
v
Y
Yb
Zn
Zr
Max.
1
130
1340
11
165
395
540
71
20
220
365
320
120
82
4250
340
310
120
12
350
1200
Mln...
1
63
540
6
10
210
96
30
20
115
58
125
41
50
19
80
210
70
5
155
370
Average
*
90
866
9
81
304
405
42
*
142
270
220
81
61
962
177
248
106
8
*
688
Max.
3
2800
4660
60
305
315
770
98
285
270
700
610
1500
78
825
9600
840
285
15
1200
1450
Min.
1
90
210
4
12
74
30
17
20
29
31
45
32
7
10
170
60
29
3
50
115
Average
*
770
1253
1253
64
193
293
40 ,
*
111
170
154
183
32
171
1987
249
102
10
310
411
* » Insufficient data to compute an average value.
» Figures encircled indicate the number of samples used to
compute average values.
128
-------
Table V-26 (Continued)
RANGE IN AMOUNT OF TRACE ELEMENTS PRESENT IN COAL ASHES (19)
(ppm)
Low volatile bituminous Medium volatile bituminous
Element
Ag
B
Ba
Be
Co
Cr
Cu
Ga
Ge
La
Mn
Ni
Pb
Sc
Sn
Sr
V
Y
Yb
Zn
Zr
Max.
1.4
180
2700
40
440
490
850
135
20
180
780
350
170
155
230
2500
480
460
23
550
620
Bin.
1
76
96
6
26
120
76
10
20
56
40
56
23
15
10
66
115
37
4
62
220
Average
*
123
740
16
172
221
379
41
*
110
280
89
50
92
818
278
152
10
231
458
Max.
1
780
1800
31
290
230
560
52
20
140
4400
440
210
110
160
1600
870
340
13
460
540
Min.
1
74
230
4
10
36
130.
10
20
19
125
20
52
7
29
40
170
37
4
50
180
Average
*
218
396
13
105
169
313
*
*
83
1432
263
96
56
75
668
390
151
9
195
326
- Insufficient data to compute an average value.
- Figures encircled indicate the number of samples used to
compute average values,
129
-------
Table 7-26 (Continued)
IN AMOUNT OF TRACE ELEMENTS PRESENT IN COAL ASHES (19)
(ppm)
Lignites and Subbituminous
Element
Ag
B
Ba
Be
Co
Cr
Cu
Ga.
Ge
La
Mn
Ni
Pb
Sc
Sn
Sr
V
Y
Yb
Zn
Zr
Max.
50
1900
13900
28
310
140
3020
30
100
90
1030
420
165
58
660
8000
250
120
10
320
490
Min.
1
320
550
1
11
11
58
10
20
34
310
20
20
2
10
230
20
21
2
50
100
Average -
*
1020
5027
6
45
54
655
23
*
62
688
129
60
18
156
4660
125
51
4
*
245
* «• Insufficient data to compute an average value.
* Figures encircled indicate the number of samples used to
compute average values.
130
-------
or dry)- The first factor, boiler type, is significant in determining
ash distribution. The boiler types which are currently in use are
pulverized coal, cyclone, and spreader stoker. Most modern boilers
are the pulverized coal type. The different methods of firing
pulverized-coal boilers are shown in figure V-ll. Table V-27 shows
the relative distributions of bottom ash and fly ash by boiler firing
method. The smallest amount of fly ash, approximately 10 percent, is
emitted by the cyclone furnace because the ash fusion temperature is
exceeded and 80-85 percent of the ash is collected as slag in the
bottom ash hopper.
A wet or dry bottom boiler influences the distribution of ash in
pulverized coal-fired boilers. Most of the modern pulverized units
utilize a dry bottom design., This type of furnace allows the ash to
remain in a dry, or non-molten, state and drop through a grate into
water-filled hoppers used to collect the ash. Ash in a dry state may
reflect either a relatively low boiler design combustion temperature
or the ash may contain constituents .which are characterized by
relatively high melting points. Since the dry ash does not fuse, it
can be fairly easily entrained in the combustion gas stream resulting
in higher fly ash/bottom ash ratios than in wet bottom boilers. The
wet-bottom boiler collects bottom ash in a fused or molten state.
This furnace is referred to as a slagging furnace. The relative
distributions of bottom ash and fly ash by type of boiler bottom are
also shown in table V-27.
Chemical Characteristics of Coal Ash
The chemical compositions of both types of bottom ash, dry or slag,
are quite similar. The major species present in bottom ash are silica
(20-60 weight percent as SiOa), alumina (10-35 weight percent as
A1Z03), ferric oxide (5-35 weight percent as Fe2O3), calcium oxide (1-
20 weight percent as CaO), magnesium oxide (0.3-0.4 weight percent as
MgO), and minor amounts of sodium and potassium oxides (1-4 weight
percent). In most instances, the combustion of coal produces more fly
ash than bottom ash. Fly ash generally consists of very fine
spherical particles, ranging in diameter from 0.5 to 500 microns. The
major species present in fly ash are silica (30-50 weight percent as
Si02), alumina (20-30 weight percent as A120), and titanium dioxide
(0.4-1.3 weight percent as Ti02). Other species which may be present
include sulfur trioxide, carbon, boron, phosphorous, uranium, and
thorium. Tables V-28 and V-29 provide some ranges for these major
species. Species concentration differences between fly ash and bottom
ash can vary considerably from one site to another.
In addition to these major components, a number of trace elements are
also found in bottom ash and fly ash. Tables V-29 and V-30 present
data concerning concentrations of these trace elements for both bottom
and fly ash for various utility plants. The trace elemental
concentrations can vary considerably within a particular ash or
between ashes. Generally, higher trace element concentrations are
found in the fly ash than bottom ash; however, there are several cases
where bottom ash exceeds fly ash concentrations.
131
-------
«f
•^» i——
J. T
T«rtiory air
i Primary air
\ i and eaal
\.k
Poirtoil
(X)
F1RINC
Primary air
and cadi
\ 4&
\
"%.
\
air
Ren Vfew of F«rnoc»
(BJ TANCENTlAt, HRINS
air
HORtZOMTAL FJIHMC
air
CO.] -CTO.ONE EJR1H6
(£.) OFTO8E&-IHO.JNEB
Figure V-ll
PULVERIZED-COAL FIRING METHODS (19)
132
-------
Table V-27
COMPARISON OF DISTRIBUTION BETWEEN BOTTOM ASH
AND FLY ASH BY TYPE OF BOILERS AND METHOD OF FIRING (19)
Bottom Ash Fly Ash
Type of Firing* Type of Boiler Bottom** (typical%) (typical%)
PCFR W 35 65
PCOP W 35 65
PCTA W 35 65
PCFR D 15 85
PCOP D 15 85
PCTA D 15 85
CYCL - 90 ' 10
SPRE - 35 65
*PCFR - Pulverized coal front firing
PCOP - Pulverized coal opposed firing
PCTA - Pulverized coal tagential firing
CYCL - Cyclone
SPRE - Spreader stoker
**W - wet bottom
D - dry bottom
133
-------
Table V-28 ^
MAJOR CHEMICAL CONSTITUENTS OF FLY ASH AND BOTTOM ASH
FROM THE SOUTHWESTERN PENNSYLVANIA REGIONS (19)
Constituent
Sulfur trioxide
Phosphorus pentoxide
Silica
Iron oxide
Aluminum oxide
Calcium oxide
Magnesium oxide
Sodium oxide
Potassium oxide
Titanium oxide
Fly Ash
(% by weight)
0.01-4.50
0.01-0.50
20.1-46.0
7.6-32.9
17.4-40.7
0.1-6.1
0.4-1.2
0.3-0.8
1.2-2.4
1,3-2.0
Bottom ash
(% by weight)
0.01-1 .0
0.01-0.4
19.4-48.9
11 .7-40.0
18.9-36.2
0.01-4.2
0.5-0.9
0.2-0.8
1.7-2.8
1.3-1 .8
134
-------
UJ
Table V-29
COMPARISON OF FLY ASH AND BOTTOM ASH FROM VARIOUS UTILITY PLANTS (19)
Compound
or
Element
Si02, %
A1203, %
Fe203, %
CaO, .%
S03, %
MgO, %
Na20, %
K2°. %
P205, %
Ti02, %
As , ppm
Be , ppm
Cd , ppm
Cr , ppm
Cu, ppm
Mg, ppm
Plant 1
FA BA
59
27
3.8
3.8
0.4
0,96
1.88
0.9
0.13
0.43
12
4.3
0.5
20
54
0.07
58
25
4.0
4.3
0.3
0.88
1.77
0.8
0.06
0.62
1
3
0.5
15
37
0.01
Plant 2
FA BA
57
20
5.8
5.7
0.8
1.15
1.61
1.1
0.04
1.17
8
7
0.5
50
128
0.01
59
18.5
9.0
4.8
0.3
0.92
1.01
1.0
0.05
0.67
1
7
0.5
30
48
0.01
Plant 3
FA BA
43
21
5.6
17.0
1.7
2.23
0.4
1.44
0.70
1.17
15
3
0.5
150
69
0.03
50
17
5.5
13.0
0.5
1.61
0.5
0.64
0.30
0.50
3
2
0.5
70
33
0.01
Plant 4
FA BA
54
28
3.4
3.7
0.4
1.29
1.5
0.38
1.00
0.83
6
7
1.0
30
75
0.08
59
24
3.3
3.5
0.1
1.17
1.5
0.43
0.75
0.50
2
5
1.0
30
40
0.01
Plant 5
BA BA
NR
NR
20.4
3.2
NR
NR
NR
NR
NR
NR
8.4
8.0
6.44
206
68
20.0
NR
NR
30.4
4.9 .
0.4
NR
NR
NR
NR
NR
5.8
7.3
1.08
124
48
0.51
Plant 6*
BA BA
42
17
17.3
3.5
NR
1.76
4 ft £•
I .JO
2.4
NR
1.00
110
NR
8.0
300
140
0.05
49
19
16.0
6.4
NR
2.06
0.67
1.9
NR
0.68
18
NR
1.1
152
20
0.028
-------
Table V-29 (Continued)
COMPARISON OF FLY ASH AND BOTTOM ASH FROM VARIOUS UTILITY PLANTS (19)
Compound
or
Element
Mn , ppm
Ni , ppm
Pb , ppm
Se, ppm
V, ppm
Zn , ppm
B, ppm
Co , ppm
F, ppm
Plant 1
FA
267
10
70
6.9
90
63
266
7
140
BA
366
10
27
0.2
70
24
143
7
50
Plant 2
FA
150
50
30
7.9
150
50
200
20
100
BA
700
22
30
0.7
85
30
125
12
50
Plant 3
FA
150
70
30
18.0
150
71
300
15
610
BA
150
15
20
1.0
70
27
70
7
100
Plant 4
FA
100
20
70
12.0
100
103
700
15
250
BA
100
10
30
1.0
70
45
300
7
85
Plant 5
BA
249
134
32
26.5
341
352
NR
6.0
624
BA
229
62
8.1
5.6
353
150
NR
3.6
10.6
Plant 6
BA
298
207
8.0
25
440
740
NR
39
NR
BA
295
85
6.2
0.08
260
100
NR
20.8
NR
KEY: FA = Fly Ash
BA = Bottom Ash
-------
Table V-30
CONCENTRATIONS OF SELECTED TRACE ELEMENTS
•*• IN COAL AND ASH AT PLANT 4710 (19)
Element Concentration
Element Coala Bottom ash Inlet fly ashb Outlet
As
Ba
Br
Cd
Ce
Cl
Co
Cr
Cs
Cu
Eu
Ga
Hf
Hg.
La
Mn
Ni
Pb
Rb
Sb
Sc
Se
Sm
Sr
Ta
Tn
U
V
Zn
4
65
3
0
8
914
2
18
1
8
0
4
0
0
3
33
16
4
15
0
2
2
1
23
0
2
2
28
46
.45
.7
.47
.2
.9
.1
.3
*1
.5
.4
.122
.8
.8
.9
.5
.5
,2
.2
.0.
.11
.1
.18
«5
18
500
2
1
84
<100
20
152
7
20
1
5
4
0
42
295
85
6
102
0
20
0
8
170
0
15
14
260
100
.1 .
.8
.7
.1
.6
.028
.2
.64
.8
.08
.2
.95.
.9
110
465
4
8
84
<200
39
300
13
140
1
81
4
0
40
298
207
80
155
12
26
25
10
250
1
20
30
440
740
.0
•3'
.1
.050
.5
.4
.1
440
750
51
120
65
900
27
1.3
5.0
42
430
650
55
36
88
36
'• 9
1.8
26
1180
5900
aMixture of coals from southern Illinois and western Kentucky,
Ash content 12%.
^Collected tipstream from electrostatic precipitator.
cCollected downstream from electrostatic precipitator.
137
-------
Figure V-12 presents the size distribution curves for fly ash and
bottom ash. The difference between the 50 percent grain sizes of
bottom ash and fly ash is approximately two orders of magnitude with
bottom ash being the larger. Fly ash demonstrates various
concentrations of trace elements in various size ranges o!f particles.
More specifically, there exists an increased concentration trend with
decreasing particle sizes as shown in table V-31.
Those data on the composition of ash particles demonstrate that
priority pollutants are present in the dry ashes and therefore can
dissolve into water when ash sluicing methods are used. The next
section addresses observed concentrations of these materials in ash
handling waters. The purpose is to assess the extent to which these
materials enter the ash sluicing waters and therefore are discharged
from the plants.
Characterization of Ash Pond Overflows.
Data From EPA Regional Offices
Table V-32 is a compilation of data obtained for ash pond overflows
from various EPA regional offices. These data summarize ash pond
effluents where the total suspended solids values are less than 30
ppm. This data was studied to determine whether a correlation existed
between TSS values and the corresponding heavy metal concentrations
(20). The results from this study of five different metals, i.e.,
arsenic, nickel, zinc, copper, and selenium, indicated that no
correlation existed between these concentrations and TSS values.
Additional data on ash pond overflow are available in the 1974
Development Document (1).
Discharge monitoring report data for 17 plants from various EPA
regional offices have been summarized. Table V-33 lists metals
concentrations for fly ash ponds, bottom ash ponds, and combined pond
systems. These metal concentrations are discharge values only; they
do not reflect a net discharge based on intake water metals
concentrations.
Tennessee Valley Authority Data
Combined Ash Ponds. In 1973, the Tennessee Valley Authority (TVA)
began collecting ash pond effluents and water intake samples quarterly
for trace metals; calcium, chloride, and silica analyses. A summary
of these data for 1973 through 1975 for plants with combined fly ash
and bottom ash ponds appears in table V-34. The complete data from
which the summary tables where prepared is presented in Appendix A.
The summary consists of the average, maximum, and minimum
concentrations for each element. The average was calculated by
substituting a value equal to the minimum quantifiable concentration
(MQC) when the reported value was less than the MQC. Thus, the
average may be biased upward if there is a significant number of
values less than the MQC. Those elements most likely affected are As,
Ba, Be, Cd, Cr, Pb, Hg, Ni, and Se.
138
-------
100
BO
eo
TO
U. ft. Slondaid Sim Optnlng In
« 4 9 MJ/2 | V4 I/Z
Inch**
11.8. SlomfarJ SUv* llumbtit
I *o
ir
90
40
20
1
9/09 4 3 610 1418 203040 BO TO 100 MO ZOO
M|OO
900
100 BO
10 0 I 0.5
Oral* 9li» Mllllmilm
0.1 0.09
0.01 O.009
0.001
Cohkli*
Olov»l
CtOflt | Fin*
Soml
Coafi» 1 Mtdlum 1 Fin*
SHI or Clotf
Figure V-12
GRAIN SIZE DISTRIBUTION CURVES FOR BOTTOM ASH AND FLY ASH (19)
-------
Table V-31
ELEMENTS SHOWING PRONOUNCED CONCENTRATION TRENDS
WITH DECREASING PARTICLE SIZE (19)
(ppm unless otherwise noted)
Particle
Diameter
(mm) Pb
A. Fly
1 .
74
44-74
2.
40
30-40
20-30
15-20
10-15
5-10
5
Tl
Ash Retained in
Sb
Plant
Cd
Se
As
Ni
Cr
Zn
Sieved fractions
140
160
7
9
Aerodynamically
90
300
430
520
430
820
980
5
5
9
12
15
20
45
1.5
7
sized
8
9
8
19
12
25
31
10
10
12
20
180
500
100
140
100
90
500
411
fractions
10
10
10
10
10
10
10
15
15
15
30
30
50
50
120
160
200
300
400
800
370
300
130
160
200
210
230
260
70
140
150
170
170
160
130
730
570
480
720
770
1100
1400
B.
Analytical method*
Airborne Fly Ash
1. Data
11.3
7.3-11.3
4.7-7.3
3.3-4.7
2.1-3.3
1.1-2.1
0.65-1 .1
1100
1200
1500
1550
1500
1600
* * *
29
40
62
67
65
76
* *
17
27
34
34
37
53
* *
13
15
18
22
26
35
• *
13
11
16
16
19
59
» *
680
800
1000
900
1200
1700
* «
460 740
400 290
440 460
540 470
900 1500
1600 3300
2. Analytical method*
d a a
8100
9000
6600
3800
15000
13000
* - (a) DC arc emission spectrometry.
(b) Atomic absorption spectrometry.
(c) X-ray fluorescence spectrometry,
(d) Spark source mass spectromety.
140
-------
Table V-32
CHARACTERISTICS OF ASH POND OVERFLOWS WITH TOTAL
SUSPENDED SOLIDS CONCENTRATIONS LESS THAN 30 mg/1 (19)
(mg/1)
Plant
Code
3711
3708
4234
0512
1226
3713
3701
2105
2102
3805
2103
* c -
o -
g -
Capacity
(MH)
781
466
598
1,341
1,229
2,000
421
511
132
660
694
coal
oil
gas
Fuel*
c/o
c/o
c/0
c
c/E
C/O
c/o
c
c/o
c
c
No. of
Samples
18
6
1
7
22
9
3
5
2
1
3
TSS
24.5
14.7
6.0
16.5
9.4
5.2
18.0
4.4
10.9
15
20
Fe
0.36
0.12
0-38
0.63
0.92
0.20
0.47
0.11
0.2
-
0.52
Cu Cd
0.1 0.02
0.1 0.02
0.01
0.01
0.03
0.1 .02
0.05 0.01
0.006 0
0.009
0.11 0.002
0.15
Ni
0.1
0.1
0.0
0.01
-
0.1
0.05
0.0004
0.0045
-
0.005
As
0.06
0.14
0.011
0.19
0.02
0.03
0.01
0.02
0.03
0.06
0.21
H>
O.I
0.1
0.05
0.14
0.01
0.1
0.05
0.004
0.04
0.01
0.007
"g
0.002
0.003
0.001
0.0006
0.002
0.001
0
0.0004
0.0001
0.0001
Zn
0.14
0.01
0.03
0.04
0.05
0.08
0.05
0.005
0.06
0.04
0.02
Se
0.007
0.005
-
0.011
-
0.03
0.10
0.004
0.018
-
0.01
P Cr
0.05
0.05
0.01
0.10 0.01
0.05
0.05
0.004
0.003
0.02
0.005
Oil &
Grease
0.23
0.16
1 .71
4.0
1.2
0.17
1.0
1.3
0.26
-
0.79
-------
Table V-33
SUMMARY OF ASH POND OVERFLOW DATA FROM >
DISCHARGE MONITORING (21)
(ppb)
Trace
Metal Fly
Ash
Ponds1
Mln. Max. Ave.
As
Cd
Cr
Cu
Fe
Pb
Hg
Ni
Se
Zn
10
3.5
5
20
1055
10
0.1
33
2
50
66
26
15
209
8138
200
1
100
7
1139
29
.9 11
.2 10
84
4011
59
.8 0
61
.8 4
358
.2
.8
.2
.8
.4
.6
.1
.4
.4
Bottom
Min.
7
2
4
5
657 1
10
0.4
13.3
2
10
Ash
Ponds2
Combined Ponds 3
Max . Ave .
70
16
41
70
0950
60
1
1345
10
302
21
.3 9
.7 15
36
3410
25
.7 0
191
6
131
.1
.7
.6
.9
.5
.8
.4
.7
.9
Min. Max.
3.5
0
2.5
0
80
0
0
0
1 .7
10
416
82
84.2
130
2600
100
65
100
68.3
293
Ave
67'
18.7
30.4
59
664.6
40.1
3.9
49
23.6
94.9
Data for 4 facilities
for 9 facilities
for 20 facilities
142
-------
Table V-34
SUMMARY OF QUARTERLY TVA TRACE METAL DATA FOR ASH POND INTAKE
AND EFFLUENT STREAMS (22)
Aluminum
Ammonia as N
Arsenic
Barium
Beryllium
Cadmium
I-* Calcium
Chloride
Chromium
Copper
Cyanide
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
EFF
RU
EFF
RU
EFF
RU
EFF
RH
EFF
RU
EFF
RH
EFF
RU
EFF
RU
EFF
RU
EFF
RU
EFF
RU
EFF
RH
EFF
RU
EFF
RU
EFF
RH
EFF
RU
EFF
RU
Minimum
0.3
0.6
0.02
0.03
<0.005
<0.005
8:!
-------
Table V-34 (Continued)
SUMMARY OF QUARTERLY T?A TRACE METAL DATA FOR ASH POND INTAKE
AND EFFLUENT STREAMS (22)
Selenium
Silica
Silver
Dissolved
Solids
Suspended
Solids
SulCate
Zinc
Mlniraun
EFF <0.001
RH <0.001
EFF 4.7
RH 5.5
EFF <0 .01
RH <0.01
EFF 260
RU 160
EFF 3
RW 11
EFF 110
RU 0.07
EFF 0.02
RH 0.03
Plant C
Average
0.010
0.002
7.4
6.1
0.01
0.01
345
205
18
46
158
23
0.13
0.08
Plant F
Minimum Average
Aluminum
Ammonia as N
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chloride
EFF 0.8
RH <0.1
EFF 0.03
RU 0.02
EFF <0.005
RH <0.005
EFF <0.1
RH <0.1
EFF <0.01
RU <0.01
EFF <0,001
RU <0.001
EFF 67 '
RU 19
EFF 4
RU 3
1.7
1.4
0.17
0.08
0.008
<0.005
0.2
0.1
<0.01
<0.0t
0.001
0.001
107
27
5
4
Maximum
0.080
0.004
11
7.9
0.03
<0.01
460
240
37
150
200
52
0.27
0.13
Maximum
3.1
3.6
.42
0.26
0.040
<0.005
0.3
0.1
-------
Table V-34 (Continued)
SUMMARY OF QUARTERLY TVA TRACE METAL DATA FOR ASH POND INTAKE
AND EFFLUENT STREAMS (22)
Plant F
Minimum Average Maximum
Plant G
Minimum Average Maximum
Plant H
Minimum Average Maximum
Plant I South
Minimum Average Maximum
Ui
Chromium
Copper
Cyanide
Icon
Lead
Magnesium
Manganese
Mercury
Nickel
Selenium
Silica
Silver
Dissolved
Solids
Suspended
Solids
Sulfate
Zinc
EFF
RU
EFF
RU
EFF
RU
EFF
RW
EFF
RU
EFF
RU
EFF
RH
EFF
RU
EFF
RU
EFF
RU
EFF
RU
EFF
RU
EFF
RU
EFF
RU
EFF
RU
EFF
RU
<0.005
<0.005
<0.01
<0.01
<0.01
<0.05
0.10
-------
Table V-34 (Continued)
OV
Aluminum
Ammonia as H
Araenlc
Barium
Beryllium
Cadmium
Calcium
Chloride
Chromium
Copper
Cyanide
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
EFF
RU
EFF
RU
EFF
RH
EFF
RU
EFF
RH
EFF
RU
EFF
RH
EFF
RU
EFF
RU
EFF
RU
EFF
RH
EFF
RU
EFF
RU
EFF
RH
EFF
RU
EFF
RW
EFF
RH
Hinitaua
0.4
0.3
0.01
0.01
0.005
0.005
8:!
<0.01
<0.01
<0.001
<0.001
20
4
2
2
<0.005
<0.005
0.02
<0.01
<0.01
0.1
0.26
<0.010
<0.010
3.9
1.2
0.05
0.03
<0.0002
<0.0002
<0.05
<0.05
Plant J
Average
2.6
0.7
0.05
0.04
0.041
0.018
0.2
0.2
<0.01
<0.01
0.001
0.001
34
15
5
2
0.005
0.005
0.11
0.08
<0.01
2.4
0.7
0.015
0.010
6.7
4.5
- 0.38
0.07
0.0003
0.0003
0.05
<0.05
Haxinum
7.6
1.4
0.08
0.23
0.130
0.110
0.3
0.4
<0.01
<0.01
0.002
0.002
57
30
21
4
0.007
0.006
0.73
0.13
<0.01
9.4
1.2
0.038
0.018
9.3
8.3
0.79
0.18
0.0008
0.0009
0.08
<0.05
Hinlraum
0.5
0.6
0.02
0.04
0.005
0.005
8:!
<0.01
<0.01
<0.001
<0.001
44
12
6
4
<0.005
<0.005
0.01
<0.01
<0.0)
0.11
0.66
0.010
0.01
0.4
2.5
0.01
0.07
<0.0002
<0.0002
<0.05
<0.05
Plane K
Average
1.8
2.0
0.06
0.09
6.033
0.009
0.2
0.1
<0.01
<0.01
0.001
<0.001
76
20
10
7
0.019
0.009
0.05
0.07
<0.01
0.39
1.9
0.017
0.01
1.6
4.3
0.02
0.10
0.0003
<0.0002
0.06
<0.05
Maximum
3.1
3.4
0.16
0.24
0.100
0.024
0.3
0.3
<0.01
<0.01
0.002
<0.001
130
28
19
10
0.036
0.027
0.10
0.12
<0.0t
1.2
3.3
0.048
0.03
3.6
6.9
0.04
0.18
0.0008
<0.0002
0.22
<0.05
Minimum
1.3
0.3
0.06
0.04
<0.005
<0.005
8:i
<0.01
<0.01
-------
Table V-34 (Continued)
SUMMARY OF QUARTERLY TVA TRACE METAL DATA FOR ASH POND INTAKE
AND EFFLUENT STREAMS (22)
Plant J
Minimum Average Maximum
Plane K Plant L
Minimum Average Maximum Minimum Average Maximum
Selenium
Silica
Silver
Dissolved
Solids
Suspended
Solids
Sulfate
Zinc
EFF
RH
EFF
RH
EFF
RH
EFF
RH
EFF
RW
EFF
RW
EFF
RW
<0.001
xo.oot
3.5
1.0
<0.01
<0.01
140
30
1
5
56
9
0.02
0.03
0.004
0.003
6.4
3.9
<0.01
<0.01
202
89
15
13
119
22
0.07
0.06
0.008
0.008
8.7
5.0
<0.01
<0.01
250
210
81
35
180
80
0.25
0.09
<0.002
<0.001
4.0
2.5
<0.01
<0.01
180
80
3
17
54
12
0.01
0.04
0.010
0.002
6.7
4.6
<0.01
<0.01
240
106
8
29
83
20
0.05
0.07
0.016
0.002
8.8
5,9
<0.01
<0.01
310
150
26
60
110
31
0.11
0.11
0.002
<0.001
4.5
3.6
<0.01
<0.01
140
70
3
4
6
9
0.02
0.03
0.010
0.002
5.7
5,t
<0.01
<0.01
211
88
12
14
80
!3
0.04
0.06
0.020
0.002
9.1
5.8
<0.01
<0.01
260
100
50
43
110
16
0.06
0.09
HOTEs Effluent data based on years 1973-1975
Raw water intake data based on years 1974 and 1975
KE¥t EFF - effluent
RH - raw water (Intakes)
-------
The average concentrations of calcium, chloride, iron, magnesium, and
manganese varied considerably from one effluent to another, while the
average concentrations of aluminum, arsenic, silica, and sulfate
varied only slightly. The average concentrations of barium, cadmium,
chromium, copper, lead, mercury, nickel, selenium, ""and zinc were
approximately the same in all the ash pond effluents. The combined
ash pond effluent at Plant D had a considerably higher concentration
of selenium (70 ppb) than the rest of the effluents, while the ash
pond effluent from Plant H had a considerably higher concentration of
arsenic (123 ppb) than the others. The plants, other than Plant H,
had less than 50 ppb arsenic in the effluents.
TVA statistically compared the intake water characteristics to those
of the effluents for Plants E, G, H, and J. Of particular importance
was the evaluation of a potential relationship between priority
pollutants (metals) and suspended solids. Essentially no correlation
existed between suspended solids in the ash pond effluent and intake
water quality characteristics.
Relationships between the ash pond effluent and the plant operating
conditions were also studied by TVA. Table V-35 provides a summary of
the TVA plant operating conditions during collection of the ash pond
effluent data. No bottom ash characteristic data were available for
this study. Statistical correlations of the data show the pH of the
ash pond effluent is influenced mainly by the calcium content of the
fly ash and by the sulfur content-of the coal. As the percent CaO
goes up, the alkalinity of the ash pond effluent increases. The
number of ash ponds in which the average concentration of each trace
element shows a net increase from the ash pond influent to the
overflow is presented in table V-36. More than half of the ash ponds
increase the concentrations of Al, NH3, As, Ba, Cd, Ca, Cl, Cr, Pb,
Hg, Ni, Se, Si, SO4 and Zn over that of the intake water. According
to studies completed by TVA (22), the range over which the trace
metals vary in the ash pond effluent appeared to be as great or
greater than that in the intake water.
Separate Bottom Ash and Fly Ash Ponds. Certain utilities utilize
separate fly ash and bottom ash ponds for handling the sluice water in.
their ash pond effluent systems. Table V-37 provides both ash pond
effluent and raw water trace element and solids data for the separate
fly ash and bottom ash ponds for .two TVA plants. The complete data
from which the summary table was prepared is presented in Appendix A.
Most of the elements appeared in greater concentrations in the fly ash
effluent than in the bottom ash effluent for Plant A. On the average,
the concentrations observed in Plant A fly ash effluents are at least
several times as great as the observed bottom ash concentrations. For
Plant B, the fly ash and bottom ash effluent concentrations are
approximately equal. Comparison of ash effluent concentrations to the
raw water concentrations for Plant A reveals that the bottom ash
concentrations are approximately equal to the raw water
concentrations. The Plant A fly ash concentrations generally exceed
the raw water concentrations. For Plant B, the bottom ash and fly
ash effluent concentrations generally exceed the raw water
148
-------
Table V.-35
SUMMARY OF PLANT OPE1ATIOM CONDITIONS AND ASH CHAMCTERISTICS
OF TVA COAL-FIRED POWER PLANTS (22)
Paraneters
Method of Firing
Coal Source M.
, Ash Content in Coal, X
* Fly Aah of Total Ash, X
Botcoa Ash of Total Ash, %
Sulfur Content In Coal, %
Coal Usage at Full Load
(tons/day)
Number of Unit a
ESP Efficiency, %
Mechanical Ash Collector
Efficiency, Z
Overall Efficiency, %
Sluice Hater to Ash Ratio
(gal/ ton)
pll of Intake Hater
Suspended Solids Concentration
of Intake Hater (rag/1)
Alkalinity of Intake Water
(»e/l «a CaC03)
Z 3102 In Fly Ash
I CaO In Fly Aah
I Fe203 in Fly Ash
X Al2«3 in Fly Ash
X lljO in fly Asii
I S03 In Fly Ash
I Holstuve In Fly Ash
pli of Fly Ash
Ash Pond Effluent
Ash Fond Effluent Suspended
Solids (mg/1)
Plant C
Cyclone
Kentucky
11
30
70
3.0
7848
3
-
90-99
-
23065
7.*
81
S3
47.6
1.72
11.3
22.7
0.93
2.2
1.04
2.9
2.1
30
Plant D
Tangential
E. Kentucky
15.5
75
25
1.2
8420
1
99
~
99
10770
7.5
15
95
HA
HA
NA
HA
HA
HA
NA
HA
8.4
19
Plant E
Cl rcular
Wall Burner
H. Kentucky H.
S.
15.J
67
33
4.1
12897
5
74
80
95
9585
7.0
17
53
46,9
4.66
14.9
18.6
1.33
1.5
0.32
11.8
11.1
<10
Plant F
Opposed
Kentucky
Illinois
16.3
80
20
3.7
24525
: - 2 ' '
99
-
-
19490
7.4
24
69
NA
NA
NA
NA
NA
NA
NA
NA
11.1
10 '
Plant G
Tangential
N. Kentucky
isi.7
80
20
3.5
10503
4
60
—
98-99
12345
7.3
12
63
53.7
2.36
9.6
26.4
1.12
1.09
-0.37
4.5
9.5
20
Plant H
Tangentla
Virginia
E. Kentucl
E. Tennesi
15
67
33
1.8
8057
•• -4
-
-
99
11425
7.0
21
73
52.5
2.19
10.2
25.5
1.42
1.9
0.63
3.6
8.7
19
Plant I
Circular
Hall Bitruar
14
70
30
3.7
14460
10
75
75.5
42430
7.4
15
58
58.7
3.17
10.7
23.9
1.24
1.2
0.22
4.6
11.0
19
Plant J
Tangential
E. Kentucky
E. Tennessee
19.1
75
25
2.1
16193
9
70
95
98
9520
7.6
15
55
50,4
1.92
11.6
25.2
1.29
0.54
0.21 '
4.0
7,5
25
Plant K
Circular
Sail Burner
S. Illinois
M. Kentucky
15.6
75
25
2.8
15304
10
60
95
98
17265
7.6
38
66
NA
HA
NA
NA
NA
NA
NA
NA
10.8
17
Plant L
Clrculai
Wall Bun
U. Kentm
N. Alabat
16
75
„ 25
2.8
17691
8
60
99
70
15370
7.5
6
63
45.3
4.91
17.0
27.0
1.22
1.16
0.87
6.5
10.1
15
NOTE: Intake water characteristics based on 1974 and 1975 weekly samples.
Ash pond effluent characteristics based on 1970-1975 weekly samples.
All plants, use combined fly ash/bottom ash ponds.
-------
Table V-36
NUMBER OF ASH PONDS IN WHICH AVERAGE EFFLUENT
CONCENTRATIONS OF SELECTED TRACE ELEMENTS EXCEED
THOSE OF THE INTAKE WATER (22)
Element
Aluminum
Ammonia
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chloride
Chromium
Copper
Cyanide
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Selenium
Silica
Silver
Sulfate
Zinc
No« Exceeding
10
9
15
7
1
7
15
8
10
5
3
4
8
6
5
12
10
14
12
2
15
7
NOTE: The total number of ash ponds is 15.
150
-------
Table V-37
SUMMARY OF QUARTERLY TRACE METAL DATA FOR ASH POND INTAKE AND
EFFLUENT STREAMS (22)
Aluminum
Ammonia as N
Arsenic
Barium
Beryllium
Cadmium
Calcium
Chloride
Chromium
Copper
Cyanide
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Selenium
EFF
RH
EFF
RH
EFF
RW
EFF
RW
EFF
RU
EFF
RU
EFF
RU
EFF
RU
EFF
RU
EFF
RU
EFF
RU
EFF
RH
EFF
RH
EFF
RU
EFF
RU
EFF
RU
IFF
RU
EFF
RU
Minimum
0.5
0.5
0.04
0.02
-------
Table V-37 (Continued)
SUMMARY OF QUARTERLY TRACE METAL DATA FOR ASH POND INTAKE AND
EFFLUENT STREAMS (22)
Ui
Plant A
Sotton Ash
Minimum Average Maximum
Plant A
Fly Ash
Minimum Average Maximum
Plant B
Bottom Ash
Hlnintun Average Maximum
Plant B
Fly Ash
Minimum Average
Maximum
Silica
Silver
Dissolved
Solids
Suspended
Solids
Sulfate
Zinc
EFF
RH
EFF
RU
EFF
RU
EFF
RU
EFF
RH
EFF
RH
5.6
1.7
<0.01
<0.01
140
120
5
14
23
6
0.02
0.06
7.4
5.6
<0.01
<0.01
185
154
52
60
45
21
0.08
0.09
9.3
8.0
<0.01
<0.01
260
200
200
190
80
30
0.16
0.14
9.3
1.7
<0.01
<0,0»
470
120
1
14
240
6
0.82
0.06
13
5.6
<0.01
<0.01
593
154
6
60
346
21
1.4
0.09
20
8.0
<0.01
<0.01
700
200
17
190
440
30
2.7
0.14
3.7
3.2
<0.01
0.01
110
90
2
8
20
9
0.02
0.01
6.4
5.4
<0.01
0.02
229
93
23
It
102
12
0.13
0.02
22
7.2
<0.01
0.05
710
100
78
14
470
18
0.55
0.04
3.1
3.2
<0.01
0.01
40
90
2
8
17
9
0.01
0.01
7.1
5.4
-------
concentrations. In both plants, iron was found in higher
concentrations in the bottom ash than the fly ash. Selenium, mercury,
and cyanide were found in very low concentrations. Arsenic was below
0.05 mg/1 in all four ponds. In both plants, the dissolved solids
were higher in the fly ash ponds while the suspended solids were
higher in the bottom ash ponds.
Table V-38 provides plant operating information for Plants A and B.
Plant A has a cyclone furnace that produces approximately 70 percent
bottom ash and 30 percent fly ash, while Plant B has pulverized coal-
fired boilers which produce 50 percent bottom ash and 50 percent fly
ash.
NUS Corporation Data. Table V-39 provides trace element information
for separate fly ash and bottom ash ponds. These data were compiled
by NUS Corporation (23). Nickel and manganese was evenly distributed
between both types of ash ponds; zinc was slightly higher in the fly
ash ponds; copper was slightly higher in the bottom ash ponds. The
fly ash pond of southeastern Ohio was the only pond that demonstrated
arsenic levels which exceeded 50 ppb.
Sampling Program Results
Screening Phase. The purpose of the screening phase of the sampling
program was to identify the pollutants in the discharge streams. The
screening phase for the ash transport stream included the sampling of
five ash pond overflows. Table V-40 presents the analytical results
for sampling for the 129 priority pollutants.
Verification Phase. The verification phase involved the sampling of
nine facilities for ash pond overflow to further quantify those
effluent species identified in the screening program. The data
reported as a result of this effort are summarized in table V-41. One
of the plants (1226) was sampled by two laboratories and both sets of
results are reported.
Arsenic Levels
Table V-42 presents data for plants in which arsenic concentrations in
the ash pond discharge streams exceed the Interim Drinking Water
Standard of 50 ppb. The maximum arsenic level is 416 ppb. Other data
concerning arsenic levels in ash pond effluents are given in table V-
43. Two plants exceed the 50 ppb level. Intake water concentrations
for arsenic are provided in tables V-40, V-41, and 'V-43. The
increases in arsenic concentrations, from the plant intake water to
the ash pond overflow, range from no increase at all for a number of
plants to a 300 ppb increase for plant 2603 in Table V-41. The range
of arsenic levels in ash pond effluents is from less than 1 ppb to 416
ppb.
153
-------
Table V-38
SUMMARY OF PLANT OPERATING CONDITIONS AND ASH
CHARACTERISTICS OF TVA COAL-FIRED POWER PLANTS
Parameters
Method of Firing
Coal Source
Ash Content in Coal, %
Fly Ash of Total Ash, %
Bottom Ash of Total Ash, "k
Sulfur Content in Coal, %
Coal Usage at Full Load (tons/day)
Number of Units
ESP Efficiency, %
Mechanical Ash Collector Efficiency,
Overall Efficiency, %
Sluice Water to Ash Ratio (gal/ton)
pH of Intake Water
Suspended Solids Concentration of
Intake Water (mg/1)
Alkalinity of Intake Water
(mg/1 as CaCOs)
% Si02 in Fly Ash
% CaO in Fly Ash
% Fe£03 in Fly Ash
% A1203 in Fly Ash
% MgO in Fly Ash
Plant A
Cyclone
W. Kentucky
18.8
30
70
4.1
22901
3
97
Plant B
Circular
Wall Burners
W. Kentucky
14.8
, 5.0
50
3314 '
4
98
98
12380f
981 Ob
7.7
60
-
-
7.5
41
56
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
154
-------
JTable V-38 (Continued)
SUMMARY OF PLANT OPERATING CONDITIONS AND ASH
CHARACTERISTICS OF TVA COAL-FIRED POWER PLANTS
Parameters Plant A Plant B
Ash Pond Effluent pH ' 4.4f 9.8f
7.2b 8.0b
Ash Pond Effluent Suspended Solids 25f 85f
(tng/1) 55b 64b
Ash Pond Only
bBottom Ash Pond Only
NOTE: Intake water characteristics based on 1974 and 1975
weekly samples. Ash pond effluent characteristics
based on 1970-1075 weekly samples.
155
-------
Table V-39
ASH POND EFFLUENT TRACE ELEMENT CONCENTRATIONS* (23)
Station Location
Western W. Virginia
Eastern Ohio
Southern Ohio
Eastern Michigan
Southeast Michigan
i— i
i
Ui
cy> , Southeast Ohio
Eastern Missouri
Central Utah
Western W. Virginia
Southern Ohio
Ash Pond Type
Bottom
Bottom
Bottom
Bottom
Fly
Fly
Bottom
Bottom
Ply
Fly
(PPb)
Arsenic
<5
7
<5
30
40
200
20
<5
8
10
Copper
<1
10
60
<1
<1
6
3
6
5
4
Nickel
11
30
30
20
20
30
20
1
30
<1
Zinc
10
90
40
270
240
50
50
5
40
. 80
Manganese
130
300
180
70
5
4
240
5
550
10
*Minimum Quantifiable Concentrations/Arsenic (5 ppb), Copper (1 ppb), Nickel
(1 ppb), Zinc (1 ppb), Manganese (1 ppb).
-------
Table V-40
SCREENING DATA FOR ASH POND OVERFLOW
Plant
Code Pollutant
4222 Methylene Chloride
(Combin- Trichlorofluoromethane
ed Fly Phenol
Ash and Bis(2-Ethylhexyl) Phthalate
Bottom Butyl Benzyl Phthalate
Ash) Toluene
Methylene Chloride
Antimony, Total
Arsenic, Total
Beryllium, Total
Chromium, Total
Copper, Total
Mercury, Total
Nickel, Total
Selenium, Total
Zinc, Total
2414 Benzene
(Combin- Chloroform
ed Fly Methylene Chloride
Ash and Phenol
Bottom Bis(2-Ethylhexyl) Phthalate
Ash) Diethyl Phthalate
Toluene
Gis 1,2-Dichloroethylene
1,1,1-Trichloroethane
1,4-Dichlorobenzene
Ethylbenzene
Arsenic, Total
Asbestos (fibers/liter)
Chromium, Total
Copper, Total
Cyanide, Total
Lead, Total
Mercury, Total
Nickel, Total
Selenium, Total
Silver, Total
Thallium, Total
.Zinc, Total
Concentration (ppb)
Intake
12
ND<1/1
2/<100
2
1
3/2
8
<5
<5
^ <5
<5
16
0.26
6
<5
14
6/13
2
4/1
45/<100
12
3
21/1
ND<1/15
ND < 1
ND < 1
1
5
28,400
<5
21
<20
7
0.88
8
15
45
6
<5
Discharge
27
6/ND<1
1/260
1
1
3/4
18
29
160
20
11
6
0.2.1
8
32
10
3/2
ND < 1
ND<1/2
NDO/31
40
ND < 1
11/70
30/ND<1
1
1
2
50
0
14
66
80
8
0.63
144
22
52
8
41
157
-------
Table V-40 (Continued)
SCREENING DATA FOR ASH POND OVERFLOW
Plant
Code Pollutant
3805 Benzene
(Combin- 1,1,1-Trichloroethane
ed Fly Chloroform
Ash and 1,1-Dichloroethylene
Bottom Ethylbenzene
Ash) Methylene Chloride
Trichlorofluoromethane
Phenol
Bis(2-Ethylhexyl) Phthalate
Tetrachloroethylene
Toluene
Trichloroethylene
Cis 1,2-Dichloroethylene
Chromium, Total
Copper, Total
Lead, Total
Mercury, Total
Selenium, Total
Silver, Total
Zinc, Total
3404 Benzene
(Bottom Chloroform
Ash) 1,1-Dichloroethylene
Methylene Chloride
Phenol
Bis(Z-Ethylhexyl) Phthalate
Di-N-Butyl Phthalate
Toluene
Antimony, Total
Arsenic, Total
Cadmium, Total
Chromium, Total
Copper, Total
Lead, Total
Mercury, Total
Nickel, Total
Selenium, Total
Silver, Total
Zinc, Total
Concentration (ppb)
Intake
1/6
1/3
ND
22/1
ND <
42/1
3/1
1/1
20/1
ND<1
3/3
2
20
0
40
2
1
1
4
2
3
39
6
19
0.23
11
12
5
1
/36
11
4
11
<5
15
16
25
5
0.34
21
55
40
<5
Discharge
ND<1/2
ND < 1
2/4
ND < 1
8/15
1
3
6
ND < 1
4/6
ND < 1
ND < 1
<5
5
<5
0.32
<5
<5
5
1
NDO/1
1/NIX1
4/ND<1
1/20
9
1
3/2
12
14
13
20
29
5
0.32
33
42
19
8
158
-------
Table V-40 (Continued)
SCREENING DATA FOR ASH POND OVERFLOW
Plant
Code Pollutant Cone en t r a t ion <| ppb)
" ' Intake Discharge
2512 Benzene NIK 1/1 1/ND<1
(Fly Ash) 1,1,1-Trichloroethane ND<1/ND<1 2/3
Chloroform 2/3 1/ND<1
1,1-Dichloroethylene 1/2 ND<1/2
Ethylbenzene ND<1/1 1/ND<1
Methylene Chloride 23/12 35/5
Bis(2-Ethylhexyl) Phthalate 1 27
Di-N-Butyl Phthalate ND < 1 1
Toluene 2/7 4/3
1,4-Dichlorobenzene 7 ND < 1
Antimony, Total <5 5
Arsenic, Total . 6 7
Copper, Total 22 14
Lead, Total <5 12
Mercury, Total 0.21 0.22
Nickel, Total 7 1,500
Selenium, Total , 35 32
Zinc, Total <5 17
159
-------
Table V-41
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE
AND ANALYSIS REPORTS FOR ASH POND OVERFLOW
Pollutant
1742 Cadmium, Total (Dissolved)
(Combined Chromium, Total (Dissolved)
Fly Ash Copper, Total (Dissolved)
and Bot- Lead, Total (Dissolved)
torn Ash Mercury, Total (Dissolved)
Pond) Nickel, Total (Dissolved)
Zinc, Total (Dissolved)
Total Dissolved Solids
Total Suspended Solids
r_i Total Organic Carbon
^ Aluminum, Total
Barium, Total (Dissolved)
Boron, Total (Dissolved)
Calcium, Total (Dissolved)
Cobalt, Total (Dissolved)
Manganese, Total (Dissolved)
Magnesium, Total (Dissolved)
Molybdenum, Total (Dissolved)
Phenolics, 4AAP
Sodium, Total (Dissolved)
Tin, Total (Dissolved)
Titanium, Total
Iron, Total
Vanadium, Total (Dissolved)
Silver (Dissolved)
Concentration (ppb)
Intake
40(5)
24/20*(ND/30)*
2l/20*(ND/9)*
9/ND<20*(ND/90)*
ND < 0.5
17/ND<5*(ND/40)*
ND/70*(30/ND<60)*
340,000
100,000
10,000
2,000
60(30)
90(200)
51,000(44,000)
10(7)
200(10)
23,000(22,000)
9(40)
6
21,000(20,000)
30(60)
40
4,000
ND/ND<10*(ND/20)
(ND/10)*
Discharge
10(9)
23/2000*(ND/30)*
106/50*(54/7)*
9/ND<20*(3/100)*
1.5(1)
39/900*(1/40)
ND/ND<60*(20/ND<60)*
370,000
15,000
150,000
ND < 50
50(50)
200(400)
51,000(53,000)
50(10)
300(ND<5)
20,000(22,000)
50(50)
12
26,000(25,000)
30(60)
ND < 20
8,000
ND/20*(ND/30)*
(ND/10)*
*These multiple results represent analyses by multiple analytical labs*
OValues in parentheses indicate dissolved fractions.
-------
Table V-41 (Continued)
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE
AND ANALYSIS REPORTS FOR ASH POND OVERFLOW
Pollutant
1741 Cadmium, Total (Dissolved)
(Bottom Chromium, Total (Dissolved)
Ash) Copper, Total (Dissolved)
Lead, Total (Dissolved)
Mercury, Total
Nickel, Total (Dissolved)
Zinc, Total (Dissolved)
Total Dissolved Solids
Total Suspended Solids
i— Total Organic Carbon
2 Aluminum, Total
Barium, Total (Dissolved)
Boron, Total (Dissolved)
Calcium, Total (Dissolved)
Cobalt, Total (Dissolved)
Manganese, Total (Dissolved)
Magnesium, Total (Dissolved)
Molybdenum, Total (Dissolved)
Phenolics, 4AAP
Sodium, Total (Dissolved)
Tin, Total (Dissolved)
Titanium, Total
Iron, Total
Vanadium, Total (Dissolved)
Beryllium, Dissolved)
Silver, (Dissolved)
Concentration (ppb)
Intake
ND < 2(3)
ND/4,000*(ND/20)*
ND/90*(ND/9)*
ND/20*(ND/100)*
ND
ND/2000*(ND/20)*
ND/ND<60*(20/ND<60)*
130,000
10,000
5,000
200
30(30)
70(ND<50)
10,000(13,000)
40(6)
800(ND<5)
9,800(5,100)
60(30)
ND
D<15,000(D<15,000)
ND < 5(30)
30
20,000
ND/10(ND<10/ND)*
(3)
(ND/6)*
Discharge
10(8)
9/ND<5*(ND/20)*
35/10*(13/7)*
14/ND<20*(ND<4/100)*
1
15/ND<5*(ND/50)*
ND/70*(ND/100)*
4,000
160,000
17,000
ND < 50
60(60)
80(100)
21,000(24,000)
ND < 5 (8)
100(700)
5,600(5,800)
8(30)
11
D<15,000(D<15,OQO)
20(20)
ND < 30
200
ND/ND<10(ND/10)
(2)
(ND/9)*
*These multiple results represent analyses by multiple analytical labs.
()Values in parentheses indicate dissolved fractions.
-------
Table V-41 (Continued)
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE
AND ANALYSIS REPORTS FOR ASH FOND OVERFLOW
Plant
Code
1741
(Fly
Ash)
Pollutant
Cadmium, Total (Dissolved)
Chromium, Total (Dissolved)
Copper, Total (Dissolved)
Lead, Total (Dissolved)
Nickel, Total (Dissolved)
Zinc, Total (Disslved)
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Barium, Total (Dissolved)
Boron, Total (Dissolved)
Calcium, Total (Dissolved)
Cobalt, Total (Dissolved)
Manganese, Total (Dissolved)
Magnesium, Total (Dissolved)
Molybdenum, Total (Dissolved)
Phenolics, 4AAP
Sodium, Total (Dissolved)
Tin, Total (Dissolved)
Titanium, Total
Iron, Total
Beryllium, (Dissolved)
Silver (Dissolved)
Vanadium (Dissolved)
Yttrium (Dissolved)
Concentration (ppb)
Intaket
Discharge
90(70)
12/6*(ND/20)*
15/9*(4/7)*
120/ND<20*(6/80)*
100/50*(58/90)*
1400/1000*(ND/1000)*
790,000
6,000
18,000
100(100)
3,000(5,000)
140,000(160,000)
10(20)
1,000(1000)
9,500(10,000)
200(300)
9
D<15,000(D<15,000)
30(20)
20
900
2
(ND/10)*
(8D/20)*
(40)
tSame intake as for Plant 1741, Bottom Ash Pond.
*These multiple results represent analyses by multiple analytical labs.
()Values in parentheses indicate dissolved fractions.
-------
Table V-41 (Continued)
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE
AND ANALYSIS REPORTS FOR ASH POND OVERFLOW
Plant
Code Pollutant
1226 Antimony, Total
(Combined Arsenic, Total
Fly Ash Cadmium, Total
and Bot- Chromium, Total
torn Ash Copper, Total (Dissolved)
Pond) Lead, Total (Dissolved)
Mercury, Total
Nickel, Total (Dissolved)
Selenium, Total
M Silver, Total
P^ Zinc, Total (Dissolved)
Total Dissolved Solids
Total Suspended Solids
Aluminum, Total (Dissolved)
Barium, Total (Dissolved)
Boron, Total (Dissolved)
Calcium, Total (Dissolved)
Cobalt, Total
Manganese, Total (Dissolved)
Magnesium, Total (Dissolved)
Molybdenum, Total (Dissolved)
Phenolics, 4AAP
Sodium, Total (Dissolved)
Titanium, Total
Iron, Total (Dissolved)
Vanadium, Total (Dissolved)
Concentration (ppb)
Intake
ND/7*
ND/3*
2.1/ND<2*
ND/7/7*
10/12/10*(10)
12/10/ND<20*(7/ND<20)*
ND<1/0.5*
27/1.5/ND<5*(29/ND<5)*
ND/ND<2*
ND/1.5/ND<1*
ND/9/70*(50/ND<60)*
190,000
14,000
700(100)
20(20)
ND < 50(70)
6,900(D<5,000)
7
200(200)
4,500(5,000)
ND < 5(ND<5)
12
33,000(36,000)
20
2,000(1,000)
ND/40/ND<10*(ND/ND<10)*
Discharge
ND/7*
ND/9*
2/ND<2*
ND/6/10*
18/14/10*(13/9)*
9/4*(4/ND<20)*
ND<0.5/ND<0.2*
ND/5.5/5*(ND/ND<5)*
ND/8*
ND/0.5/ND<1*
ND/7/ND<60*(ND/ND<60)*
2,350,000
12,000
300(500)
60(60)
400(900)
34,000(32,000)
ND < 5
30(6)
7,300(7,500)
100(100)
17
66,000(72,000)
ND < 20
600(ND<200)
ND/78/50*(ND/40)*
*These multiple results represent analyses by multiple analytical labs.
()Values in parentheses indicate dissolved fractions.
-------
Table V-41 (Continued)
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE
AND ANALYSIS REPORTS FOR ASH POND OVERFLOW
Plant
Code Pollutant Concentration (ppb)
Intake Discharge
5409 Benzene 2.4 2
(Fly Ash) Carbon Tetrachloride D < 1
Chloroform 1.4
1,2-Dichlorobenzene 5.3
Ethylbenzene D < 1
Toluene 2 3.5
Trichloroethylene D < 4
Antimony, Total 3 6
Beryllium, Total ND < 0.5 2.5
t-* Cadmium, Total 1.4 1.0
f. Chromium, Total ND < 2 4
Copper, Total 27 80
Cyanide, Totl 15,000 22
Lead, Total 8 ND < 3
Nickel, Total 1.7 9.5
Selenium, Total 2.0 3.0
Silver, Total 1.6 5.5
Thallium, Total 1 ND < 1
Zinc, Total 15 300
Total Suspended Solids 5 15,000
Total Organic Carbon D < 20,000 7,600
Chloride 37,000
Vanadium, Total 13 27
1,3 and 1,4-Dichlorobenzene 2.4 2.4
*These multiple results represent analyses by multiple analytical labs.
QValues in parentheses indicate dissolved fractions.
-------
Table V-41 (Continued)
SUMMARY OF DATA FROM TEE VERIFICATION PROGRAM AND EPA SURVEILLANCE
AND ANALYSIS REPORTS FOE ASH POND OVERFLOW
2603
(Combined
Fly Ash
and Bot-
tom Ash
Pond)
cr>
ui
Pollutant
Benzene
Chloroform
1,1-Dichloroethylene
Ethylbenzene
Methylene Chloride
Phenol (GC/MS)
Bis(2-Ethylhexyl)Phthalate
Butyl Benzyl Phthalate
Di-N-Butyl Phthalate
Diethyl Phthalate
Dimethyl Phthalate
Tetrachloroethylene
Antimony, Total
Arsenic, Total
Cadmium, Total
Chromium, Total
Copper, Total
Mercury, Total
Nickel, Total
Selenium, Total
Silver, Total
Zinc, Total
Total Dissolved Solids
Total Suspended Solids
Oil and Grease
Total Organic Carbon
Aluminum, Total
Concentration (ppb)
Intake
» < 10
D < 10
ND
ND
D < 10
ND/9*
D < 10
D < 10
D < 10
50
ND
D < 10
ND < 2
ND < 20
ND < 2
10
22
07
*£.
8
ND < 2
ND < 1
88
292,000
9,000
497
Discharge
» < 10
D < 10
D < 10
D < 10
10
ND/4*
D < 10
ND
D < 10
10
D < 10
ND
10
300
3
12
10
10
13
4
ND < 60
455,000
D < 5000
1,000
6,000
131
*These multiple results represent analyses by multiple analytical labs.
QValues in parentheses Indicate dissolved fractions.
-------
Table V~41 (Continued)
SUMMARY OP DATA. FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE
AND ANALYSIS REPORTS FOR ASH POND OVERFLOW
Plant
Code
Pollutant
Concentration (ppb)
2603 Barium, Total
(Cont'd) Boron, Total
Calcium, Total
Manganese, Total
Magnesium, Total
Molybdenum, Total
Sodium, Total
Tin, Total
Titanium, Total
Iron, Total
Vanadium, Total
5604 Benzene
(Combined Ethylbenzene
Fly Ash) Toluene
Antimony, Total
Beryllium, Total
Cadmium, Total
Chromium, Total
Copper, Total
Cyanide, Total
Lead, Total
Mercury, Total
Nickel, Total
Silver, Total
Zinc, Total
Total Suspended Solids
Total Organic Carbon
Chloride
Vanadium, Total
*These multiple results represent analyses by multiple analytical labs.
QValues in parentheses indicate dissolved fractions.
Intake
ND
ND
—
ND
ND
ND
ND
ND
ND
-
17
< 50
48,700
65
15,300
< 5
23,600
36
18
842
1.2
9.1
4
< 0.5
< 0.5
< 2
700
4
6
< 0.2
< 0.5
< 3
53
5,500
14,000
11
Discharge
92
209
62,100
10
15,500
143
32,000
36
ND < 15
170
22
2.0
D < 1
3.5
6
2.5
1.0
4
80
22
ND < 3
0.2
9.5
5.5
300
15,000
7,600
37.000
27
-------
Table V-41 (Continued)
SUMMARY OF DATA PROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE
AND ANALYSIS REPORTS FOR ASH POND OVERFLOW
Plant
Code
3920
(Ply Ash)
01
Pollutant
Beryllium, Total (Dissolved)
Chromium, Total (Dissolved)
Copper, Total (Dissolved)
Lead, Total (Dissolved)
Nickel, Total (Dissolved)
Zinc, Total (Dissolved)
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Aluminum, Total (Dissolved)
Barium, Total (Dissolved)
Boron, Total (Dissolved)
Calcium, Total (Dissolved)
Cobalt, Total (Dissolved)
Manganese, Total (Dissolved)
Magnesium, Total (Dissolved)
Molybdenum, Total (Dissolved)
Phenolics, 4AAP
Sodium, Total (Dissolved)
Iron, Total
Cadmium (Dissolved)
Silver (DIssolvedO
Tin (Dissolved)
Concentration (ppb)
Intake
ND (ND)
20/2*(10/ND<5)*
ND<6/8(4/ND<6)*
20/ND<20*(18/40)*
25/ND<3*(14/ND<5)*
ND/ND<60*(ND/ND<60)*
220,000
12,000
5,000
ND<50(ND<50)
30(30)
80(90)
28,000(27,000)
ND<5(ND<5)
50(50)
7,200(7,400)
ND<5(6)
40
18,000(17,000)
500
(ND<3)
(ND/ND)*
(20)
Discharge
2(2)
50/9*(41/8)*
ND/30*(ND/40)*
8/ND<20*(14/30)*
16/20*(ND<9/40)*
180/100*(ND/200)*
880,000
73,000
3,000
5,000(6,000)
60(ND<5)
1,000(5,000)
120,000(120,000)
7(7)
300(500)
6,700(9,700)
10(8)
40
35,000(47,000)
2,000
(10)
(ND/5)*
(20)
*These multiple results represent analyses by multiple analytical labs,
QValues In parentheses Indicate dissolved fractions.
-------
Table V-41 (Continued)
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE
AND ANALYSIS REPORTS FOR ASH POND OVERFLOW
Plant
Code
3924
(Fly Ash)
oo
3001
(Combined
Fly Ash
and Bot-
tom Ash
Pond)
Pollutant
Chromium, Total (Dissolved)
Copper, Total (Dissolved)
Lead, Total (Dissolved)
Nickel, Total (Dissolved)
Zinc, Total (Dissolved)
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Barium, Total (Dissolved)
Boron, Total (Dissolved)
Calcium, Total (Dissolved)
Manganese, Total (Dissolved)
Magnesiumi Total (Dissolved)
Molybdenum, Total (Dissolved)
Phenolics, 4AAP
Sodium, Total (Dissolved)
Iron, Total
Aluminum (Dissolved)
Tin (Dissolved)
Chromium, Total (Dissolved)
Copper, Total (Dissolved)
Lead, Total (Dissolved)
Nickel, Total (Dissolved)
Total Dissolved Solids
Total Suspended Solids
Oil and Grease
Aluminum, Total (Dissolved)
Concentration (ppb)
Intake
7/ND<5*(ND/ND<5)*
18/10*(16/9)*
10/ND<20*(5/ND<20)*
18/ND<5*(ND/ND<5)*
20/ND<60*(20/ND<60)*
480,000
15,000
21,000
40(40)
100(100)
57,000(55,000)
100(50)
13,000(14,000)
ND<5(ND<5)
38
43,000(44,000)
500
ND < 50
(20)
ND/10*(ND/10)*
ND/10*(22/ND<6)
ND/ND<20*(ND/ND<20)*
ND/6*(ND/ND<5)*
532,000
170,000
25,000
500(ND<50)
Discharge
27/70*(49/ND<5)*
32/ND<6*(42/ND<6)*
23/ND<20*(l/ND<20)*
23/40*(10/6)*
20/ND<60*(ND/ND<60)*
670,000
16,000
16,000
200(200)
1,000(4,000)
110,000(110,000)
80(70)
14,000(14,000)
300(300)
35
38,000(39,000)
300
60
(ND<5)
190/ND*(93/40)*
ND/ND<6*(20/ND<6)*
3/ND<20*(4/ND<20)*
35/ND<5*(33/ND<5)*
490,000
30,000
24,000
2,000(200)
*These multiple results represent analyses by multiple analytical labs,
QValues in parentheses indicate dissolved fractions.
-------
Table V-41 (Continued)
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE
AND ANALYSIS REPORTS FOR ASH POND OVERFLOW
Plant
Code
3001
(Cont'd)
o\
vo
5410
(Combined
Ely Ash
and Bot-
tom Ash
Pond)
Pollutant
Barium Total (Dissolved)
Boron, Total (Dissolved)
Calcium, Total (Dissolved)
Manganese, Total
Cadmium (Dissolved)
Magnesium, Total (Dissolved)
Molybdenum, Total (Dissolved)
Phenolics, 4AAP
Sodium, Total (Dissolved)
Tin, Total (Dissolved)
Iron, Total
Vanadium, Total
1,1,2,2-Tetrachloroethane
Zinc (Dissolved)
Cadmium, Total (Dissolved)
Chromium, Total (Dissolved)
Copper, Total (Dissolved)
Lead, Total (Dissolved)
Nickel, Total (Dissolved)
Silver, Total (Dissolved)
Zinc, Total
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Aluminum, Total
Barium, Total (Dissolved)
Boron, Total (Dissolved)
Concentration (ppb)
Intake
40(60)
60(200)
38,000(48,000)
40
ND < 2
23,000(27,000)
ND < 5(ND<5)
57,000(66,000)
ND < 5(20)
200
ND/NDOO*
24
(ND/ND<60)*
9(6)
7/70*(9/7)*
15/6*(9/ND<6)*
17/ND<20*(9/ND<20)*
22/30*(9/6)*
ND/ND
-------
Table V-41 (Continued)
SUMMARY OF DATA FROM THE VERIFICATION PROGRAM AND EPA SURVEILLANCE
AND ANALYSIS REPORTS FOR ASH POND OVERFLOW
Plant
Code
Pollutant
Concentration (ppb)
o
Intake
27,000(27,000)
ND < 5
40(ND<5)
7,700(7,300)
ND < 5
9
18,000(17,000)
10(ND<5)
HD < 20
400
ND/ND<10*
ND < 20
ND
5410 Calcium, Total (Dissolved)
(Cont'd) Cobalt, Total
Manganese, Total (Dissolved)
Magnesium, Total (Dissolved)
Molybdenum, Total
Phenolics, 4AAP
Sodium, Total (Dissolved)
Tin, Total (Dissolved)
Titanium, Total
Iron, Total
Vanadium, Total
Yttrium, Total
Arsenic (Dissolved)
4203 1,1,1-Trichloroethane
(Combined Chloroform
Fly Ash Methylene Chloride
and Bot- Pentachlorophenol
torn Ash Tetrachloroethylene
Pond) Trichloroethylene
4,4'-ODD (P.P'-TDE)
Arsenic, Total
Cadmium, Total
Chromium, Total
Copper, Total
Lead, Total
Nickel, Total
Selenium, Total
Silver, Total
Zinc, Total
Iron, Total
*These multiple results represent analyses by multiple analytical labs.
OValues in parentheses indicate dissolved fractions.
Discharge
40,000(38,000)
20
100(200)
9,100(8,200)
8
6
22,000(24,000)
10(6)
50
2,000
ND/10*
20
14
0.25
32
6.5
-------
Table V-42
CONDITIONS UNDER WHICH ARSENIC IN ASH POND OVERFLOW EXCEEDS 0.05 mg/1 (19)
(mg/D
Plant Plant
Oil and No. of
Code
3711
3708
0512
3710
4218
3701
2103
3805
*c -
0 -
Capacity
781
466
1341
290
1163
421
694
660
coal
oil
Fuel*
c/o
c/o
c
c/o
c/o
c/o
c
c
PH
6.48 '
8.48
8.29
9.07
6.63
-
8.4
-
TSS
24.5
14.7
16.5
127
36.8
18.0
20
15
As
0.06
O.Ki
0.19
0.416
0.131
0.09
0.21
0.06
Cu
0.1
O.I
0.01
0.12
0.075
0.05
0.15
0.11
Cr
0.05
0.05
0.01
0.05
0.002
0.05
0.005
0.02
Cd
0.02
0.02
-
0.02
-
o.oi
-
0.002
Ni
O.I
O.I
0.01
O.I
0.038
0.05
0.005
Fe
0.36
0.14
0.63
0.3
0.74
0.47
0.52
Pb
O.I
O.I
0.14
O.I
0.002
0.05
0.007
0.01
"8
0.002
0.003
0.001
0.0023
0.0005
0.001
0.0001
0.0001
Zn
0.14
0.01
0.04
0.11
0.087
0.05
0.02
0.04
Se
0.007
0.005
0.011
0.05
-
0.10
0.01
Grease
0.23
0.16
4.0
0.13
0.9
1.0
0.79
Sainj
18
6
7
3
1
3
3
1
-------
Table V-43
ARSENIC CONCENTRATIONS IN ASH POND EFFLUENTS (23, 24)
N>
Station
Location
Western W. Virginia
Eastern Ohio
Southern Ohio
Eastern Michigan
Southeast Michigan
Southeast Ohio
Eastern Missouri
Central Utah
Western W. Virginia
Southern Ohio
Wyoming
Florida
Upper Appalachia
Size
(MW)
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
750
948
2900
Ash Pond
Effluent Plant Water
Type Concentrations intafce uonc.
Bottom
Bottom
Bottom
Bottom
Fly
Fly
Bottom
Bottom
Fly
Fly
Combined
Combined
Combined
(ppb)a
<5
7
<5
30
40
200
20
<5
8
10
<1
9
74
(ppb)
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
<1
3
<1
Data
Sources
23
23
23
23
23
23
23
23
23
23
24
24
24
aDetection limit for NUS is 5 ppb/for Radian, 1 ppb.
NA - Not Available
-------
LOW VOLUME WASTES
Low volume wastes include boiler blowdown, waste streams from water
treatement, and effluent from floor and yard drains.
Boiler Blowdown
Power-plant boilers are either of the once-through or drum-type
design. Once-through designs are used almost exclusively in high-
pressure, supercritical boilers and have no wastewater streams
directly associated with their operation. Drum-type boilers, on the
other hand, operate at subcritical conditions where steam generated in
the drum-type units is in equilibrium with boiler water. Boiler water
impurities are, therefore, concentrated in the liquid phase. The
concentration of impurities in drum-type boilers must not exceed
certain limitations which are primarily a. function of boiler operating
conditions. Table V-44 presents recommended limits of total
(dissolved and suspended) solids in drum-type boilers as a function of
drum pressure (25). Boiler blowdown, therefore, serves to maintain
specified limitations for dissolved and suspended solids. In response
to the 308 questionnaire, 544 powerplants put of a total 794 indicated
presence of boiler blowdown at their facilities.
The sources of impurities in the blowdown are the intake water,
internal corrosion of the boiler, and chemicals added to the boiler
system. Impurities contributed by the intake water are usually
soluable inorganic species (Na+, K+, C1-, So42, etc.) and
precipitates containing calcium/magnesium cations. Products of boiler
corrosion are soluble and insoluble species of iron, copper, and other
metals. A number of chemicals are added to the boiler feedwater to
control scale formation, corrosion, pH, and solids deposition. A
summary of types of chemicals used for these purposes is presented in
table V-45. In addition, the following proprietary chemicals which
may contribute chromium, copper, and phenol species to the boiler
blowdown were identified:
NALCO 37 - contains chromium
NALCO 75 - contains phenol
NALCO 425L - contains copper
CALGON CL35 - contains sodium dichromate.
The boiler blowdown is usually of high quality and even may be of
higher quality than the intake water. It is usually suitable for
internal reuse in the powerplant, for example, as cooling water makeup
(26, 27). Tcible V-46 presents a statistical analysis of regional EPA
data on the quality of boiler blowdown. It should be noted that mean
concentrations of phosphorous are computed on the basis of 19 data
points. Phosphorous is evidently contributed by phosphate-containing
chemicals used for solids deposition control. Under certain
conditions, the concentrations of corrosion products such as copper
and iron may be high. One power company in Southern California
reported maximum concentrations of copper and iron as 2 and 20 ppm,
173
-------
Table V-44
RECOMMENDED LIMITS OF TOTAL SOLIDS IN
BOILS! WATER FOR DRUM BOILERS (25)
Drum Pressure
(atmj
0-24.4
20.41-30.5
30.51-40.8
40.18-51.0
51.01-61.0
61.01-68.0
68.01-102.0
102-01-136
>136
Tpsi)
0-300
301-450
451-600
601-750
751-900
901-1000
1001-1500
1501-2000
>2000
Total Solids (mg/1)
3500
3000
2500
2000
1500
1250
1000
750
15
174
-------
Table V-45
CHEMICAL ADDITIVES COMMONLY ASSOCIATED WITH
INTERNAL BOILER TREATMENT (25)
Control
Objective
Scale
Corrosion
pH
Solids
Deposition
Candidate Chemical Additives
di— and tri-sodium phosphates
Ethylene diaminetetracetic
acid (EDTA)
Nitrilotriacetic acid (NTA)
Alginates
Polyacrylates
Polymethacrylates
Sodium sulfite and catalyzed
Sodium sulfite
Hydrazine
Morpholine
Sodium hydroxide
Sodium carbonate
Ammonia
Morpholine
Hydrazine
Tannins
Lignin derivitives
Starch
Alginates
Polyacrylamides
Polyacrylates
Polyme thacry1ate s
Phosphates
Residual Concentration
.in Boiler Water
3-60 mg/1 as
20-100 mg/1
10-60 mg/1
up to 50-100 mg/1
less than 200 'mg/1
5-45 mg/1
added to adjust
boiler water pH to
the desired level,
typically 8.0 - 11.0
<200 mg/1
20-50 mg/1
175
-------
Table V-46
STATISTICAL ANALYSIS OF BOILER SLOWDOWN CEARACTERISTICS
(Discharge Monitoring Data - EPA Regional Offices)
Mean
Number of Concentration
Pollutants Points (mg/1) Log. Mean Standard Deviation Log. Deviation
Copper
Iron
Oil & Grease
Phosphorous
Suspended
258
273
151
19
230
.14
.53
1.74
17.07
66.26
2.9615
2.3486
.0276
1.8363
1.2198
.2888
2.0609
4.5311
12.5154
500.3967
1.2845
1.6351
k
.9807
2.3911
1.9421
-------
respectively. These high values were observed immediately after
boiler chemical cleaning (26).
Boiler blowdown may be discharged either intermittently or con-
tinuously. Table V-47 contains a statistical analysis of flow rates
reported in the 308 responses from industry.
Three plants were sampled for boiler blowdown during the verification
phase of the sampling program. The results are summarized in; Table V-
48. Pollutants not listed were not detected. l
Water Treatment
Boiler feedwater is treated for the removal of suspended and dissolved
solids to prevent scale formation. The water treating processes
include clarification, filtration, lime/lime soda softening, ion
exchange, reverse osmosis, and evaporation.
Clarification
Clarification is»the process of agglomerating the solids in a stream
and separating them by settling. The solids are coagulated, by
physical and chemical processes, to form larger particles and ttten
allowed to settle. Clarified water is drawn off and may be> filtered
to remove any traces of turbidity (1). Chemicals commonly added to
the clarification process are listed in table V-49. As the table
shows, none of these chemicals contain any of the 129 .priority
pollutants. Table V-50 presents a statistical analysis of clarifier
blowdown flow rates reported by the industry in response to the 308
questionnaires. Table V-51 presents a statistical analysis of filter
backwash flow rates reported by the industry in response to the 308
questionnaires.
Ion Exchange
Ion exchange processes can be designed to remove all mineral salts in
a one-unit operation and, as such, is the most common means of
treating supply water. The ion exchange material is an organic
resinous material manufactured in bead form. The resin may be one of
two types: cation or anion. The ion exchange process generally
occurs in a fixed bed of the resin beads which are electrically
charged. The beads attract chemical ions of opposite charge. Once
all of the available sites on the resin beads have been exhausted, the
bed must be regenerated. During regeneration, the bed is b^ckwashed
(the normal flow throughout the bed is reversed), causing the bed to
erupt and the solids to be released. A regenerant solution is then
passed over the resin bed, for approximately 30 minutes for cation
resins and 90 minutes for anion resins. The bed is then rin$ed with
water to wash the remaining voids within the bed.
The resulting exchange wastes are generally acidic or alkaline with
the exception of sodium chloride solutions which are neutral! While
these wastes do not have significant amounts of suspended solids,
i • .
177
-------
Table V-47
BOILER SLOWDOWN FLOWRATES
(308 questionnaire data)
Variable
co
Number Mean Standard Minimum Maximum
of Plants Value Deviation Value Value
Fuel:
Flow:
Fuel:
Flow:
Fuel:
Flow:
coal*
GPD/ plant
GPD/MW
gas*
GPD/platit
GPD/MW
oil*
GPD/ plant
GPD/MW
231
230
189
189
148
148
33,259
148
19,346
163
66,173
287
71,682
392
60,933
669
320,106
1,237
0.11 650,000
3,717
4 700,000
0.08 8,470
2=7 3,810,000
0.12 14,066
*Fuel designations are determined by the fuel which contributes the most Btu for
power generation for the year 1975.
-------
Table V-48
SURVEILLANCE AND ANALYSIS DATA FOR BOILER BLOWDOWN
Plant
Code
1003
Concentration (ppb)
V0
Pollutant
Chloroform
Dichlorobromomethane
Chlorodibromomethane
Arsenic, Total
Copper, Total
Mercury, Total
Zinc, Total
Total Dissolved Solids
Total Suspended Solids
Oil and Grease
Total Organic Carbon
Phenolicss 4AAP
Intake
68
23
3.8
3
9
1
104
207,000
2,800
2,280
D < 20
Discharge
ND
ND
ND
2
8
10
100,000
800
5,000
1,250
D < 20
4203 1,1,2-Trichloroethane
Chloroform
Bromoform
Dichlorobromomethane
Chlorodibroraoinethane
Phenol, GC/MS
Trichloroethylene
Antimony, Total
Arsenic, Total
Cadmium, Total
Copper, Total
Lead, Total
Mercury, Total
Zinc, Total
Iron, Total
ND <
ND <
0,
4.
0,
0.
0,
4.
0.
1
2
4
22
20
1,
10
10
23
4
0?
87
17
2
13
ND
ND
ND
ND
ND
0.12
6.4
6
2
5
520
40
1,
68
60
-------
Table V-48 (Continued)
SURVEILLANCE AND ANALYSIS DATA FOR BOILER SLOWDOWN
Plant
Code
2603
Unit 11
Concentration (ppb)
00
o
Pollutant
Benzene
1,1,1-Triehloroethane
1,1,2,2-Tetrachloroethane
Chloroform
1,1-Dichloroethylene
Ethylbenzene
Methylene Chloride
Phenol, GC/MS
Bis(2-Ethylhexyl) Phthalate
Butyl Benzyl Phthalate
Di-N-Butyl Phthalate
Diethyl Phthalate
Tetrachloroethylene
Toluene
Trichloroethylene
Antimony, Total
Chromium, Total
Copper, Total
Lead, Total
Mercury, Total
Nickel, Total
Selenium, Total
Zinc, Total
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Calcium, Total
Manganese, Total
Magnesium, Total
Intake
10
10
D <
ND
ND
D <
ND
ND
D < 10
ND/9
D
D
D <
D <
ND
D <
ND <
ND <
ND <
10
10
10
50
10
10
; 2
10
22
20
0,
8
2
292,000
9,000
48,700
65
15,300
Discharge
D <
D <
D <
D <
290
10
10
10
60
10
910
ND/15
D < 10
ND
10
10
10
10
D <
D <
D <
D <
ND
10
6
26
36
ND < 0.1
1.3
5.7
72
11,000
D < 5,000
D < 3,000
D < 5,000
ND < 5
ND < 1,000
-------
Table V-48 (Continued)
SURVEILLANCE AND ANALYSIS DATA FOR BOILER SLOWDOWN
Plant
Code
Pollutant
2603 Molybdenum, Total
Unit #1 Sodium, Total
(Cont'd) Titanium, Total
Iron, Total
Concentrat ion (ppb)
Intake Discharge
ND < 5
18
842
61
D < 15,000
ND < 5
oo
2603* Benzene
Unit #2 1,1-Diehloroethylene
1,3-Dichloropropene
Ethylbenzene
Methylene Chloride
Br OHIO form
Phenol, GC/MS
Di-N-Butyl Phthalate
Diethyl Phthalate
Tetrachloroethylene
Toluene
Ant imony, Total
Copper, Total
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Aluminum, Total
Calcium, Total
Molybdenum, Total
Sodium, Total
D <
30
10
10
10
30
10
ND/10
D
D
D
D
D
7,
3,
D <
D <
10
10
10
10
20
8
000
5,000
000
213
5,000
55
15,000
*Intake data for Plant 2603, Unit #2 is the same as that for Plant 2603, Unit f1 .
-------
Table V-49
COAGULATING AND FLOCCULATING AGENT CHARACTERISTICS (25)
Coagulant/Flocculant:
Alum
A12(S04)3 .
Aluminate
H20
Ferric Chloride
FeCl2 • 6 H20
co Copperas
* 7 H20
Weighting Agents
(bentenite, kaolin,
mon tmor illonite)
Absorbents
(powdered carbon,
activated alumina)
Polyeleetrolytes
(inorganic activated
silica and organic
polymers)
Purpose
Main Coagulant
To assist coagulation with
aluminate
Main Coagulant
To assist coagulation with
alum
Main Coagulant
Main Coagulant
Coagulant Aid
Coagulant Aid
Coagulant Aid
Normal Dosage (mg/1)
5-50
2-20
5-15
(0.1 to 0.5 of
alum dosage)
5-50
5-50
<2
-------
Table ¥-50
CLARIFIER BLOWDOWN FLOWRATES
(308 questionnaire data)
Variable
Fuel: coal*
Flow: gpd/plant
gpd/MW
Fuel; gas
Flow: gpd/plant
gpd/MW
Fuel: oil
Flow: gpd/plant
gpd/MW
Number Mean Standard Minimum Maximum
of Plants Value Deviation Value Value
88 29,966 74,518.4 7
87 64.8 200.9 0.04
26 57,653 234,909 10
26 210.8 914 0.11
14 19,779 29,820 20
14 107.9 196.8 0.15
605,000
.1,208
1,200,000
4,678
100,420
697
*Fuel designations are determined by the fuel which contributes the most Btu
for power generation for the year 1975.
-------
Table V-51
FILTER BACKWASH FLOWRATES
(308 questionnaire data)
Variable
Number Mean Standard Minimum Maximum
of Plants Value Deviation Value Value
Fuel : coal*
Flow: gpd/plant
gpd/MW
Fuel: gas*
,_. Flow: gpd/plant
£ gpd/MW
Fuel : oil*
Flow: gpd/plant
gpd/MW
155
154
58
58
58
58
25,460
71
7,827
41
25,003
168
42,027
258
15,153
87
58,410
677
1.6
0.013
40
0.1
30
0.13
300,000
2,400
94,200
404
250,000
4,528
*Fuel designations are determined by the fuel which contributes the most Btu for
power generation in the year 1975.
-------
certain chemicals such as calcium sulfate and calcium carbonate have
extremely low solubilities and are often precipitated because of
common ion effects.
The wastes may*be collected in an equalization tank or basin and
neutralized with acid or alkali or slowly mixed with other nonprocess
wastes prior to treatment. In the cases where the wastes are mixed
with other non-process water, there may be the effect of
neutralization by the natural alkalinity or acidity of the non-process
stream. In any of the treatment cases discussed above, the treated
water is suitable for reuse as non-process makeup water.
Spent regenerant solutions, constituting a significant part of the
total flow of wastewater from ion exchange regeneration, contains ions
which are eluted from the ion exchange material plus the excess
regenerant that is not consumed during regeneration. The eluted ions
represent the chemical species which were removed from water during
the service cycle of the process. Table V-52 presents a summary of
ion exchange material types and regenerant requirements of each.
Historical raw waste load data for ion exchange regenerant is shown in
table V-53. Table V-54 contains a statistical analysis of ion
exchange spent regenerant flow rates reported in the industry response
to the 308 questionnaire.
Lime/Lime Soda Softening
In lime softening, chemical precipitation is applied to hardness and
alkalinity. Calcium precipitates as calcium carbonate (CaC03) and
magnesium as magnesium hydroxide (Mg(OH)2). The softening may take
place at ambient temperatures, known as cold process softening, or at
elevated temperatures (100 C or 212 F), known as hot process softening
(1). The hot process accelerates the formation of the carbonates and
hydroxides. Hot process softening is commonly employed for treating
boiler feed water in facilities where steam is generated for heating
processes as well as electric power generation. Since lime and/or
soda ash are the only chemicals added in this process, none of the
priority pollutants will be introduced in the system. Table V-55
presents a statistical analysis of lime softener blowdown flow rates
reported by the industry in response to the 308 questionnaires.
Evaporator Blowdown i:-
Evaporation is a process of purifying water by vaporizing it with a
heat source and condensing the vaporized water. The influent water
evaporates arid is ducted to an external product condenser. In the
lower portion of the evaporator, a pool of boiling water is maintained
at a constant level to keep the heat source (steam tubes) immersed in
liquid. Water is periodically blown down from the bottom to lower the
contaminant levels. Table V-56 presents historical raw waste load
data for the evaporator blowdown. As indicated in this table,
suspended solids in the blowdown may reach very high levels. Table V-
57 presents a statistical analysis of evaporator blowdown flow rates
reported by the industry in response to the 308 questionnaires.
• • 185 •
-------
Table V-52
ION EXCHANGE MATERIAL TYPES AND REGENERANT REQUIREMENT (25)
Ion Exchange Material
Cation Exchange
Sodium Cycle
Hydrogen Cycle
Weak Acid
Strong Acid
Anion Exchange
Weak Base
Strong Base
Description of Operation
Sodium cycle ion exchange is used as
a water softening process. Calcium,
"magnesium, and other divalent cations
are exchange for more soluble sodium
cations, i.e.,
(Rc)2 - Ca + 2 NA*
2 2 - 804 + 2HOH
Strong base Ion exchange removes
anions of all soluble salts in water
i.e.,
Regenerant Solution
10% brine (NaCl) solution or
some other solution with a
relatively high sodium con-
tent such as sea water.
112SO4 or HC1 solutions with
acid strengths as low as
0.5%.
H2S04 or 1IC1 solutions with
acid strengths ranging from
2.0-6.07..
NaOH, NH^OH, ^82003 solutions
of variable strength
NaOH solutions at approximate
4.0% strength.
Regenerant
Requirement
Theoretical Amount
110-1201
200-400%
120-140%
150-300%
RA - OH + H2C03 RA - HC03 + HOH
-------
Table V-53
ION EXCHANGE SPENT REGENERANT CHARACTERISTICS
(Discharge Monitoring Data - EPA Regional Offices)
'»
Pollutant
pH (122 entries)
Suspended solids (mg/1)
(88 entries)
Dissolved solids (mg/1)
(39 entries)
Oil and Grease (mg/1)
Mean
Value
6.15
44
6,057
6.0
Standard
Deviation
2.45
60.14
2,435
6.7
Minimum
Value
1.7
3.0
1,894
0.13
Maximum
Value
10.6
305
9,645
22
(29 entries)
-------
Table V-54
ION EXCHANGE SOFTENER SPENT REGENERANT FLOWRATES
(308 Questionnaire Data)
00
oo
Variable
Number Mean . Standard Minimum Maximum
of Plants Value Deviation Value Value
Fuel:
Flow:
Fuel:
Flow:
Fuel:
Flow:
coal*
gpd/plant
gpd/MW
gas*
gpd/plant
gpd/MW
oil*
gpd/plant
gpd/MW
104
104
86
86
42
42
9,290
79
11,142
84
19,358
226
16,737
264
32,663
247
32,965
764
14.4
0.12
7
0.12
16
0.43
107,143
2,028
164,000
2,058
132,000
4,633
*Fuel designations are determined by the fuel which contributes the most Btu for
power generation in the year 1975.
-------
Table V-55.
LIME SOFTENER BLOWDOWN FLOWRATES
(308 Questionnaire Data)
VO
Variable
Number Mean Standard Minimum Maximum
of Plants Value Deviation Value Value
Fuel:
Flow:
Fuel:
Flow:
Fuel:
Flow:
coal*
gpd/ plant
gpd/MW
gas*
gpd /pi ant
gpd/MW
oil*
gpd/plant
gpd/MW
37
37
40
40
15
15
26,228
56
30,937
154
15,808
216
85,069
117
144,642
558
57,099
818
29
0.28
15
0.17
75
0.62
, 50,000
625
900,000
3,508
222,180
3,174
*Fuel designations are determined by the fuel which contributes the most Btu for
power generation in the year 1975.
-------
Table V-56
EVAPORATOR SLOWDOWN CHARACTERISTICS
(Discharge Monitoring Data - EPA Regional Offices)
•JD
O
Mean
Number of Concentration
Pollutants Points
Copper 9
Iron 9
Oil & Grease 9
Suspended
Solids 31
(IHR/I)
.39
.54
2.1
28.4
Log . Mean
-.9671
-.6198
.7085
2.4499
Standard Deviation
.0875
.0831
.4841
36.7079
Log . Deviation
.2080
.1543
.2404
1.5392
-------
Table V-S7
EVAPORATOR SLOWDOWN FLOWRATES
(308 Questionnaire Data)
Variable
Number Mean Standard Minimum Maximum
of Plants Value Deviation Value Value
Fuel:
Flow:
Fuel:
Flow:
Fuel:
Flow:
coal*
gpd/plant
gpd/MW
gas*
gpd/plant
gpd/MW
oil*
gpd/plant
gpd/MW
104
104
83
83
57
57
29,310
126
13,647
74
320,293
4,781
96,221
810
34,312
222
2,111,836
34,796
•" 2 '
8
0.02
15
0.11
962,800
8,292
215,000
1 ,512
15,900,000
262,809
*Fuel designation are determined by the fuel which contributes the most Btu for
power generation in the year 1975
-------
Reverse Osmosis
Reverse osmosis is a process in which a semipermeable membrane—
generally cellulose acetate or a polyamide—separates two solutions of
different concentrations. In the case of a salt solution, use of a
membrane impermeable to salt will allow only water to leave the
solution, producing one stream with a greater salt concentration than
the feed and one, more dilute. The concentrated stream is called the
reverse osmosis brine and constitutes the waste stream from the
process. Table V-58 presents a statistical, analysis of reverse
osmosis brine flow rates reported by the industry in response to the
308 questionnaires. In the water treatment schemes reported by the
industry, reverse osmosis was always used in conjunction, with
demineralizers and sometimes in conjunction with clarification,
filtration, and ion exchange softening.
Drains and Spills
Floor and Yard Drains
There are numerous sources of wastewater in the nature of piping and
equipment drainage and leakage throughout a steam electric facility.
The list in table V-59 is a representative compilation of the sources,
showing major contaminants, the likelihood of occurrence, potential
severity, and control techniques which might be employed. There have
been no data reported for this stream, however, the pollutant
parameters which may be of concern would be oil and grease, pH, and
suspended solids.
Laboratory Streams
Many steam electric powerplants maintain laboratory, facilities to
carry out chemical analyses as a part of controlling the operation of
the plant. This would include elemental analysis and heating value
analysis of coal, analysis of treated boiler water, and boiler tube
cleaning chemical analysis.
The wastes from the laboratories vary in quantity and constituents,
depending on the use of the facilities and the type of powerplant.
The chemicals are usually present in extremely small quantities. It
has been common practice to combine laboratory drains with other plant
plumbing.
Sampling Results
Demineralizer regenerants were sampled in three facilities during the
verification phase of the sampling program. Analytical results are
presented in Table V-60.
METAL CLEANING WASTES
Metal cleaning wastes include wastewater from chemical cleaning of
boiler tubes, air preheater washwater, and boiler fireside washwater.
192
-------
Table V-58
OSMOSIS BEINE FLOWRATES
(308 Questionnaire Data)
Variable
Number Mean Standard Minimum Maximum
of Plants Value Deviation Value Value
Fuel:
Flow:
Fuel:
Flow:
•
coal*
gpd/ plant
gpd/MW
gas*
gpd/ plant
gpd/MW
3
3
11
11
10,674
31
18,179
55
18,192
53
27,437
42
3
0.25
465
23
31,680
92
95,000
165
*Fuel designations are determined by the fuel which contributes the most Btu for
power generation in the year 1975.
-------
Table V-59
EQUIPMENT DRAINAGE AND LEAKAGE (1)
Source
Oil-water Heat
Exchangers
Oil Tank, Lines &
Transformer
Rupture
Floor Spills
Oil Drips and
Tank Leakage
Sump Discharges
from Service
Bldg. & Yard
Chemical Tank
Rupture
Chemical Tank
Leakage
Major Contaminanta
Oil
Frequency
Potential
Severity
Oil
Suspended Solids or Oil
Oil
Remote Severe
Possibility
Remote Severe
Possibility
Daily
Daily
Oil and Suspended Solids Often
Slight
Slight
Slight
Regenerant and cleaning Remote Severe
chemicals Possibility
Regenerant and cleaning Occasional Slight
chemicals
Potential. Control Techniques
1. Continuous Gravity Separation
2. Detection and Batch Gravity
Separation
3. Detection & Mechanical
Separation
4. Maintain pressure of water
greater than oil
1 . Isolation from Drains
2. Containment of Drainage
1, Plug Floor Drain
2. Route Floor Drainage Through
Clarifier & Gravity or
Mechanical Separation
1. Isolate from Floor Draina
2. Route to Gravity or
Mechanical Separation
1. Isolate and route ciarifier
and gravity or mechanical
separation
1. Containment of Drainage
2. Isolation from Drains
3. Route drains to Ash Pond or
Holding Pond for
Neutralization
1. Isolate from Floor Drains
2. Route drains to Ash Pond or
Holding Pond
NOTE: Oil Spill Contingency Plans would apply to significant oil releases.
-------
Table V-60
SURVEILLANCE AND ANALYSIS DATA FOR DEMINERALIZER REGENERANT
Plant
Code
1003
Cone en t r a tion ( ppb)
Ul
4203
Pollutant
1,1,1-Trichloroethane
Chloroform
Bromoform
Dichlorofluoromethane
Arsenic, Total
Copper, Total
Mercury, Total
Selenium, Total
Zinc, Total
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Chlorobenzene
1,1,2-Trichloroethane
Chloroform
V,2-Dichlorobenzene
1,3-DichlorobenEene
1,4-Dichlorobenzene
Methylene Chloride
Bromoform
Dichlorobrornotnethane
Chlorodibromomethane
Nitrobenzene
Phenol, GC/MS
Di-N-Octyl Phthalate
Trichloroethylene
Arsenic, Total
Cadmium, Total
Chromium, Total
Intake
ND
68
23
^ ft
3 « O
•J
•j
9
i
i
1
104
207 ,000
2,800
2,280
ND
0.23
4.4
ND
ND
ND
ND
0.07
0.87
0.17
ND
4.2
ND
0.13
o
£.
4
ND<2
Discharge
2
1.8
. '
_____
«. w. — — .*
4,584,000
9,250
4,810
0.67
0.68
38
39
0.3
5.2
>220
ND
ND
ND
81
3.8
22
0.38
35
26
-------
Table V-60 (Continued)
SURVEILLANCE AND ANALYSIS DATA FOR DEMINERALIZER REGENERANT
Plant
Code
Concentration (ppb)
Pollutant
4203 Copper, Total
(Cont'd) Cyanide, Total
Lead, Total
Mercury, Total
Nickel, Total
Silver, Total
Zinc, Total
Iron, Total
Acetone
2603 Benzene
Chloroform
1,1-Dichloroethylene
Methylene Chloride
Broraoform
Diehlorobromomethane
Chlorodibromomethane
Phenol, CC/MS
Bis(2-Ethylhexyl) Phthalate
Butyl Benzyl Phthalate
Di-N-Butyl Phthalate
Diethyl Phthalate
Tetrachloroethylene
Trichloroethylene
Antimony, Total
Cadmium, Total
Chromium, Total
Copper, Total
Cyanide, Total
Mercury, Total
Intake
22
0
ND<20
1.5
ND<20
ND<2
10
10
D<10
ND<10
ND
D<10
ND
ND
ND
ND/9
D<10
D<10
D<10
50
D<10
D<10
ND<2
ND<2
10
22
ND<5
0.2
Discharge
65
0.04
24
1.6
230
58
54
5,000
ft 7
o * /
ND
140
D<10
60
D<10
70
30
ND/4
D<10
_____
D<10
D<10
D<10
ND
20
5
14
27
47
6
-------
Table V-60 (Continued)
SURVEILLANCE AND ANALYSIS DATA FOR DEMINERALIZER REGENERANT
Plant
Code
Concentration (ppb)
Pollutant
*-*
2603 Nickel, Total
(Cont'd) Selenium, Total
Thallium, Total
Einc, Total
Total Dissolved Solids
Total Suspended Solids
Total Organic Carbon
Aluminum, Total
Barium, Total
Boron, Total
Calcium, Total
Manganese, Total
Magnesium, Total
Molybdenum, Total
Sodium, Total
Titanium, Total
Iron, Total
Intake
8
ND<2
ND<20
88
292,000
9,000
497
17
ND<50
48,700
65
15,300
ND<5
18
842
Discharge
200
4
182
ND
3,010,000
1 7 nnfl
I / , UUU
8,000
277
ND<5
63
169,000
9
17,400
15
1 "\Q ftAH
I .jy , uuu
ND<15
793
-------
Chemical Cleaning of Boiler Tubes
Chemical cleaning is designed to remove scale and corrosion products
which accumulate on the boiler tubes in the boiler's-, ' steam-side.
There are—a number of factors affecting the selection of^'the cleaning
method. Among the major factors are:
1. Type of deposit,
2. Type of metals (alloys) cleaned,
3. Type of boiler, •
4. Economics,
5. Prior experience,
6. Hazards associated with cleaning agents, and
7. Ease of waste disposal.
Boiler Cleaning Chemicals
Hydrochloric Acid Without Copper Complexer. Hydrochloric acid is the
most frequently used boiler tube cleaning chemical. It has the
ability to handle a wider range of deposits than any other solvent
available today. This ability, combined with its relatively low cost,
availability, and the extensive experience associated with its use for
boiler cleanings, is the reason for its popularity in the chemical
cleaning of utility boilers (28).
Hydrochloric acid, which is usually used in solutions of 5 to 10
percent, forms soluble chlorides with the scale and corrosion products
in the boiler tubes. Its strength makes it very effective for
removing heavy deposits; however, due to this strength, an inhibitor
is mandatory to reduce attack to boiler tube metal. This strength
also allows the use of either the soaking or circulation method of
boiler cleaning.
The high chloride content makes the use of hydrochloric acid solutions
infeasible for austenitic steels due to the potential for chloride
stress cracking (29). Hydrochloric acid is highly corrosive.
Hydrogen gas will be liberated during cleaning operations. Large
amounts of water are required for rinsing.
Hydrochloric Acid With Copper Complexer. Hydrochloric acid with a
copper complexer is used in boilers containing copper to prevent the
replating of dissolved copper onto steel surfaces during chemical
cleaning operations. The two most prominent complexers are Dow
Chemical's Thiourea and Halliburton's Curtain II. If a complexer is
not used, copper chlorides, formed during cleaning operation, react
with boiler tube iron to form soluble iron chlorides while the copper
198
-------
is replated onto the tube surface. Use of a copper complexer
interrupts this reaction by complexing the copper (30,31).
Alkaline Deoreaser. Alkaline cleaning (flush/boil-out) is commonly
employed prior to boiler cleaning to remove oil-based compounds from*11"
tube surfaces. These solutions are composed of trisodium phosphate
and a surfactant and act to clear away the materials which may
interfere with the reactions of the boiler cleaning chemicals and
deposits (32, 33).
Ammoniated Citric Acid. Citric acid cleaning solutions are used by a
number of utilities for boiler cleaning operations (34). Utilizing
the circulation method, this weak acid is usually diluted to a 3
percent solution and ammoniated to a pH of 3.5 for cleaning purposes.
This solution is used in a two-stage process. The first stage
involves the dissolution of iron oxides. In the second stage,
anhydrous ammonia is added! to a pH of 9 to 10 and air is bubbled
through the solution to dissolve copper deposits. Halliburton markets
this as the Citrosolv Process (35). This "one solution" cleaning
process affords some advantages due to the minimal cleaning time and
water requirements. The hazards associated with this solution are not
as great as with other acids due to its lower corrosivity; however,
there is potential for hydrogen gas liberation.
Ammoniated EDTA. The most widely known ammoniated EDTA cleaning
chemical is produced by Dow Chemical Company and marketed under the
name, "Vertan 675." This boiler cleaning agent has been used
successfully in a wide variety of boiler cleaning operations. , The
cleaning involves a one solution, two-stage process. During the first
stage, the solution solubilizes iron deposits and chelates the iron
solution. In the second stage, the solution is oxidized with air to
induce iron chelates from ferric to ferrous and to oxidize copper
deposits into solution where the copper is chelated (36).
The most prominent use of this cleaning agent is in circulating
boilers which contain copper alloys. It has gained increasing
popularity for use in cleaning utility boilers due to its low hazard
(no hydrogen gas formation and not highly corrosive) and low water
usage (normally only one rinse required).
Ammonic-al Sodium Bromate. Occasionally, large amounts of copper
deposits in boiler tubes cannot be removed with hydrochloric acid due
to copper's relative insolubility. When such conditions exist,
solutions of ammonia-based oxidizing compounds have been effective.
Used in a single separate stage the ammonical sodium bromate step
includes the introduction of solutions containing ammonium bromate
into the boiler system to rapidly oxidize and dissolve the copper.
This stage may be completed pre- or post-acid stage. It has been
found to be effective on units which contain large amounts of copper
metals (37).
Hydroxyacetic/Formic Acid. The use of hydroxyacetic/formic acid in
the chemical cleaning of utility boilers is common. It is used in
199
-------
boilers containing austenitic steels because its low chloride content
prevents possible chloride stress corrosion cracking of the
austenitic-type alloys. It has also found extensive use in the
cleaning operations for once-through supercritical boilers (38).
Circulation of this solvent is required i^order to.keep desired
strength in all areas of the boiler system. Hydroxyacetic/formic acid
has chelation properties and a high iron pick-up capability, thus it
is used on high iron content systems. It is not effective on hardness
scales. If water requirements are low, generally only one rinse is
required. The corrosiveness of the solvent is not as high as that of
inorganic acids, yet there is potential for hydrogen gas release.
SuIfuric Acid. Sulfuric acid has found limited use in boiler cleaning
operations. It is not feasible for removal of hardness scales due to
th© formation of highly insoluble calcium sulfate (39). It has found
some use in cases where a high-strength, low-chloride solvent is
necessary. As with other acids, potential hazards involve the
liberation of hydrogen gas and the chemical's highly corrosive nature.
Use of sulfuric acid requires high water usage in order to rinse the
boiler sufficiently.
Waste Characteristics
The characteristics of waste streams emanating from the chemical
cleaning of utility boilers are similar in many respects. The major
constituents consist of boiler metals; i.e., alloy metals used for
boiler tubes, hot wells, pumps, etc. Although waste streams from
certain cleaning operations which are used to remove certain deposits;
i.e., alkaline degreaser to remove oils and organics/ do not contain
heavy concentrations of metals, the primary purpose of the total
boiler cleaning operation (all stages combined) is removal of heat
transfer-retarding deposits, which consist mainly of iron oxides
resulting from corrosion. This removal of iron is evident in all
total boiler cleaning operations through its presence in boiler
cleaning wastes.
Copper is the next most prevalent constitutent of boiler cleaning
wastes due to wide use as a boiler system metal. Based on information
on nearly 2,500 utility boilers, EPA estimates that copper alloys are
used in 91 percent of the steam condenser tubes, 85 percent of the
highpressure feedwater heater tubes, and 83 percent of the lowpressure
feedwater heater tubes (40). Table v-61 shows a few of these alloys
and corresponding constituents.
The presence of boiler metal constituents in chemical cleaning wastes
is further illustrated by examining the characteristics of wastes
emanating from boilers in which admiralty metals were used for steam
condenser tubes and low-pressure feedwater heater tubes. Admiralty
metal contains aproximately 25 percent zinc.
The wastewaters from a boiler cleaning operation on a boiler
containing such an alloy contained 166 mg/1 of zinc. The relatively
200
-------
Table V-61
M.LOYS AND C&NSTITUENTS OF BOILER SYSTEMS (41)
(Percent)
Alloy Constituent
. Admiralty
Arsenical Admiralty
Phosphorized Admiralty
Brass
Aluminum brass
Copper-nickel 90/10
Copper-nickel 80/20
Copper-:nickel 70/30
Cupro-nickel (10%)
Cupro-niekel (20%)
Monel
Copper
71
71
71
,65
65 .
90
80
70
89
79
23
Iron Nickel
10
20
30
1 .0 1:0
1.0 20
3.5 60
Zinc Other ,
25 Sn-4
27 As-0.04
27 P-0.1
35
30 A1-5
*
Mn-3.5
201
-------
high value of zinc was due to the presence of zinc in the boiler tube
metal (1).
A number of cleaning agents use completing agents in order to keep
dissolved deposits in solution and thus remove them from the boiler
system when the solution is drained.- Ammoniated solutions of bromate,
citrate, and EDTA have been used for this purpose. Ammonia forms a
complex with -copper while citrate and EDTA chelate iron and other
heavy metals. Ammonia is a monodentate complex former since it
contains only one ligand. Citrate and EDTA are multidentate complex
formers. Multidentate complexes may be referred to as chelates,
whereas monodentate complexes are referred to only as complexers (42).
These complexes and chelates are stable compounds and pose greater
difficulty in treatment.
Other waste constituents present in spent chemical cleaning solutions
include wide ranges of pH, high dissolved solids concentrations, and
significant oxygen demands (BOD and/or COD). The pH of spent
solutions ranges from 2.5 to 11.0 depending on whether acidic or
alkaline cleaning agents are employed.
Waste characteristics for the above mentioned cleaning solutions
appear in tables V-62 through V-67. A brief description of those
wastes by chemical cleaning solvent type follows.
Alkaline Degreaser. Alkaline cleaning is used to remove oil con-
taminants which may have entered the boiler system. The cleaning
solution waste will contain sodium phosphates, and some boiler metals.
In some cases, if chelating agents and sodium hydroxide have been
added to the original cleaning solution, these materials and related
compounds may be present. Volume of waste solutions will exceed two
boiler volumes due to intermittent blowdowns and a final rinse with
condensate.
Ammoniated Citric Acid. This waste stream consists of a number of
complexed boiler metals. Their presence is dependent upon their use
in boiler metals alloys. Citrate, a multidentate ligand, is the
chelating agent in this solution, while ammonia forms soluble
complexes with copper. Various other constituents of this waste
stream will include dissolved deposit components and BOD. Waste
volume is generally equivalent to two boiler volumes, which includes a
rinse.
Ammoniated EDTA. Ammoniated EDTA wastes are alkaline (pH = 9.0 to
10.0) and contain amounts of iron and copper which are present as
ferric and cupric chelates. Although this type of cleaning agent is
used generally for removal of copper, the copper content will vary in
concentration in proportion to the amount of copper used in the boiler
system. Similarily, the content of other boiler metals present in the
waste will generally be-a function of their presence. The volume of
waste from this type of cleaning is usually two boiler volumes. One
volume consists, of the cleaning solution while the second will be
rinse water.
202
-------
Table V-62
WASTE "CONSTITUENTS OF AMMONIATED CITRIC ACID SOLUTIONS (48)
(mg/l)
CONSTITUENTS
Silica
Phosphorous
Copper
Iron
Nickel
Zinc
C-1
220
8,300
130
390
C-2
40
200
20
9,800
C-3
8
10,800
NOTE: (1) The absence of concentration value denotes informa-
tion is not available.
(2) C-1, C-2, C-3 denote wastes from independent boiler
chemical cleaning operations.
203
-------
Table V-63
WASTE CONSTITUENTS OF AMMONIATED EDTA SOLUTIONS (48)
(mg/1)
CONSTITUENTS
Waste Volume,
million gallons
pH, units
Dissolved Solids
Suspended Solids
Oil & Grease
Silica
NH3 - N
Phosphorous
Aluminum
Calcium
Chromium
Copper
Iron
Magnesium
Manganese
Nickel
Sodium
Zinc
V-1
9.2
V-2
8.8
V-3
9.0
V-4
9.5
V-5
9.5
93.69
V-6
19,000
9.2
59,549
V-7
10.0
73,800
24
41
5,200
260.25
31.23
20.82
10.41
11,700 30 53 413 124.92
2,250 4,600 7,900 7,000 8,328
20.82
72.87
135.33
124.92
45.3
26.50
707
6,867
11.12
49.93
68.40
371.87
143.75
11.6
0.17
6,900
- 11.8
79
NOTE: (1) The absence of concentration value denotes information is not
available.
(2) V-1 through V-7 denote wastes from independent boiler chemical
cleaning operations.
-------
Table V-64
WASTE CONSTITUENTS OF AMMONIACAL SODIUM BROMATE SOLUTIONS (48)
(mg/1)
CONSTITUENTS AB-1 AB~2 AB-3 AB-4 AB-5 AB-6
Waste Volume,
million gallons • 0.217 0.165
pH, units 10.5 10.2
Dissolved Solids 1,015 340 1,400
Suspended Solids 77 8 71
COD 24 120
Oil & Grease <5 <5
Silica 7.2 14
NH3 - N 700 2,000
Org. - N 40 <10
N02 + N03 - N • 0.04 0.51
Phosphorous 10 30
Bromide 52 <5
Chloride 60
Fluoride 1.5 6.1
Aluminum <0.2 <0.2
Arsenic 307 0.048 <0.005
barium <0.1 <0.1
Beryllium <0.01 <0.01
Cadmium <0.02 <0.001 <0,001
Calcium 0.0 3.0 0.4
-------
Table ?~64 (Continued)
WASTE CONSTITUENTS OF AMMQNIACAL SODIUM BROMATE SOLUTIONS (48)
(mg/1)
CONSTITUENTS
Chromium
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
Silver
Sodium
Tin
Zinc
AB-1
<0.05
409
1 .92
0.1
14.9
255
23.6
1.03
AB-2
750
AB-3
AB-4
AB-5
AB-6
0.0
117
0.15
0.0
0.01
0.08
59
<0.005
334 100
0 1.7
<0.01
2.9
0.03
<0.0002
0 0.52
70
1 <0.002
<0.01
3.7
<0.005
790
4.9
<0.01
0.67
0.04
<0.0002
2.5
220
<0.002
<0.02
15
0.41
0.5
0.06
0.54
NOTE: (1) The absence of concentration value denotes information is not
available.
(2) AB-1 through AB-6 denote wastes from independent boiler chemical
cleaning operations.
-------
Table V-65
WASTE CONSTITUENTS OF HYDROCHLORIC ACID WITHOUT COPPER COMPLEXER SOLUTIONS (48)
CONSTITUENTS H-1 H-2 H-3 K-4 K-5 H-6 H-7
Waste Volume,
million gallons
pH, units
Suspended Solids
COD
TOC
Oil & Grease
Phenols
Silica
NH3 - N
o N02 + N03 - N
"^ Phosphorous
Sulfate
Aluminum
Arsenic
Barium
Beryllium
Cadmium
Calcium
0.200
3.3
57
9,900
4,600
23
0.05
19
325
225
1.2
0.008
<0.001
16
0.217
0.8
8
1 ,200
240
<5
0.065
66
140
0.06
0.07
30
<1
6.5
0.06
<0.1
<0.01
<0.01
42
0.099
0.7
120
1 ,500
90
11
0.070
120
80
140
<0.01
50
10
6.6
0.01
0.4
<0.01
0.051
70
0.087
0.7
18
1 ,200
1,800
7.6
0.035
240
220
75
<0.01
35
<1
7.0
0.03
0.1
<0.01
0.032
53
0.070
0.5
35
1,900
220
20
0.020
31
290
10
<0.01
50
<1
8.2
0.055
0.3
<0.01
0.1
64
0.090
0.7
33
1 ,500
120
23
0.025
150
870
45
0.035
<0.001
74
-------
Table V-65 (Continued)
WASTE CONSTITUENTS OF HYDROCHLORIC ACIP WITHOUT COPPER COMPLEXER SOLUTIONS (48)
(mg/1)
CONSTITUENTS
Chromium
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Selenium
N Silver
o Sodium
Tin
Zinc
H-1
H-2
H-3
H-4
H-5
H-6
H-7
43
1,125
150
15.8
<0.005
0.69
4,200
19
110
0.94
1.5
2.2
1,300
0.4
8.7
6.9
<0.002
77
1.4
<0.004
0.02
31
<1
5.9
6
7.6
3,820
3.8
6.5
29
<0.002
260
2.3
<0.002
0.02
74
7.3
170
1.1
18
1,420
0.86
5.7
10
<0.002
170
1.5
<0.002
0.07
40
<1
34
8.8
13
3,720
5.2
8.8
28
<0.002
300
1.8
<0.002
0.03
49
2.8
53
<0.005
47
2,780
<0.01
22
150
24
NOTE: (i) The absence of concentration value denotes information is not
available.
(2) H-1 through H-7 denote wastes from indenpendent boiler chemical
cleaning operations.
-------
Table V-66
WASTE CONSTITUENTS OF HYDROCHLORIC ACID WITH COPPER COMPLEXER SOLUTIONS (48)
(mg/1)
CONSTITUENTS
Dissolved Solids
Suspended Solids
Silica
Phosphorous
Calcium
Chromium
Copper
Iron
Manganese
Nickel
Sodium
Zinc
HC-1
HC-2
HC-3
HC-4
HC-5
HC-6
280
100
20
4,600
3
30
300
460
1,900
410
680
110
2,100
20
10
960
3,200
500
840
30,980
2,375
980 66.6
16.8
270 530
6,200 6,470
8.16
267
9.2
.132
NOTE: (1) The absence of concentration values denotes information is not
available.
(2) HC-1 through HC-6 denote wastes from independent boiler chemical
cleaning operations.
-------
Table V-67
WASTE CONSTITUENTS OF HYDROXYACETIC/FORMIC ACID SOLUTIONS (48)
(mg/l)
CONSTITUENTS HFA-1 HFA-2 HFA-3 HFA-4
Copper 2
Iron 9,800 3,600 6,300 2,900
Nickel 5
Zinc 8
NOTE: (1) The absence of concentration value denotes information is not
available,
(2) HFA-1 through HFA-4 denote wastes from independent boiler chemical
cleaning operations.
-------
AnmoniacaJ Sodium Bromate. Ammoniated sodium bromate solutions are
used to remove large amounts of copper from boiler systems. Nitrogen
compounds will be present in large quantities due to the ammonia.
This cleaning step is followed by a rinse which makes the volume of
this chemical cleaning waste equivalent to two boiler volumes.
Hydrochloric Acid Without Copper Complexer. These wastes are
generally high in total iron contentration (100 mg/1), low in total
copper (100 mg/1) and vary with low to medium concentrations of nickel
and zinc, depending on boiler metal alloys. Other significant
constituents of this type of waste stream consist of solubilized
deposit materials, such as calcium, silica, phosphorous, and oil and
grease. Some rather low quantities of arsenic, cadmium, chromium,
manganese, and tin are also present due to slight acidic attack on
boiler metals. The volume of wastes associated with this type of
cleaning is generally four times the boiler capacity. This accounts
for rinses and neutralization steps in addition to the acid cleaning
step.
Hydrochloric Acid With Copper Complexer. The use of the copper
complexer implies that copper is present in the system as a boiler
metal and therefore must be removed to prevent replating onto steel
surfaces. This copper is present as a complex, as are the
concentrations of nickel and zinc which are present mainly at moderate
levels. As with waste hydrochloric acid solutions without copper
complexer, iron concentrations are very high, generally ranging from
2,000 to 6,000 mg/1, while other constituents consist of lower
quantities of other boiler metals. Volume of waste associated with
this cleaning process is generally four to five boiler volumes due to
rinses and neutralization steps.
Hydroxyacetic/Fotrmic Acid. Hydroxyacetie/formic acid has chelating
properties which, at times, may enable a 3 percent solution of these
mixed acids to exceed a dissolved iron content of 1.3 percent. Other
metals generally do not have high concentrations in this waste
cleaning solution due to absence in boiler metals. As with most
organic solvents, the total volume will be twice the boiler capacity
because a rinse must follow the cleaning step. The organic nature of
the solvent will also result in elevated BOD levels.
Sulfuric AcjLd. This boiler cleaning agent is not widely used. The
waste characteristics are probably similar to those of hydrochloric
acid without copper complexer. Sulfuric acid is a strong acid which
may find use in austenitic steels due to its low chloride content.
Metal constituents will vary with their use in boiler metals. Volume
of the waste, including rinses and neutralizing steps, will approach
four to five boiler volumes.
Sampling Results
A boiler cleaning effluent was analyzed for the presence of priority
organics. None of the organics met or exceeded the limit of
quantification.
211
-------
Boiler Fireside Washing
Boiler firesides are commonly washed by spraying high-pressure water
against boiler tubes while they are still hot. Waste effluents from
this washing operation contain an assortment of dissolved and
suspended solids. Acid wastes are common for boilers fired with high-
sulfur fuels. Sulfur oxides absorb onto fireside deposits, causing
low pH and a high sulfate content in the waste effluent (25). Table
V-68 presents average and maximum concentrations of pollutants in
fireside washes from Plant 3306 (43). Table V-69 shows historical
waste load data for boiler fireside wash waters. Table V-70 presents
a statistical analysis of fireside wash flow rates reported by the
industry. The daily average flow was computed by multiplying the
frequency of cleaning per year times the volume per cleaning and
dividing the product by 365.
Air Preheater Washing
Air preheaters employed in power stations are either the tubular or
regenerative types. Both are periodically washed to remove deposits
which accumulate. The frequency of washing is typically once per
month; however, frequency variations ranging from 4 to 180 washings
per year are reported (1). Many air preheaters are sectionalized so
that heat transfer areas may be isolated and washed without shutdown
of the entire unit (25). Higher wash frequencies are expected for air
preheaters employing this design feature.
Fossil fuels with significant sulfur content will produce sulfur
oxides which adsorb on air preheater deposits. Water washing of these
deposits produces an acidic effluent. Alkaline reagents are often
added to wash water to neutralize acidity, prevent corrosion of
metallic surfaces, and maintain an alkaline pH. Alkaline reagents
might include soda ash (Na2C03), caustic soda/NaOH), phosphates,
and/or detergent. Preheater wash water contains suspended and
dissolved solids which include sulfates hardness, and heavy metals,
including copper, iron, nickel, and chromium (1, 25). Waste
characteristics data for these waste waters are presented in table V-
71. In table V-72, the EPA raw waste load data for air preheater wash
water is shown. Table V-73 presents a statistical analysis of air
preheater wash flow rates reported by the industry in response to the
308 questionnaire.
COAL PILE RUNOFF
In order to ensure a consistent supply of coal for steam generation,
plants typically maintain an outdoor reserve. A 90-day supply is
generally maintained to provide a sufficient safety factor. This
correlates to approximately 600 to 1,800 m3 (780 to 2,340 yards3) of
stored coal per megawatt of required capacity (1,20). Four factors
which may preclude maintaining a large coal reserve are (20):
1. Cost of land required for storage,
212
-------
Table V-68
AVERAGE AND MAXIMUM CONCENTRATIONS AND LOADING
IN RAW WASTEWATER FROM FIRESIDE WASHES AT PLANT 3306 (43)
Const ituent
Total chromium
Hexavalent chromium
Zinc
Nickel
Copper
Aluminum
Iron
Manganese
Sulfate
TDS
TSS
Oil and Grease
Concentration
(mg/1)
15 max., 1.5 ave.
<1,0 max., Q«02 ave.
40 max., 4.0 ave.
900 max., 70 ave.
250 max., 6.0 ave.
21 max., 2,0 ave.
14,000 max., 2,500 ave.
40 max., 3.5 ave.
10,000 max., 1,000 ave.
50,000 max., 5,000 ave.
25,000 max., 250 ave.
Virtually
Loading
(kg/cleaning)
6.8 ave. (15 Ib)
0.09 ave. (0.2 Ib).
18 ave. (40 Ib)
317 ave. (700 Ib)
27 ave. (60 Ib)
9 ave. (20 Ib)
11,340 ave. (25,000 Ib)
16 ave. (35 Ib)
4,540 ave. (10,000 Ib)
22,680 ave. (50,000 Ib)
1,135 ave. (2,500 Ib)
Absent
-------
Table V-69
WASTE LOAD DATA FOR BOILER FIRESIDE WASH
(Discharge Monitoring Data - EPA Regional Offices)
(mg/1)
Pollutant
Suspended solids
(7 entries)
Copper (7 entries)
Iron (7 entries)
Mean
Value
15,387
47.82
9,630.86
Standard
Deviation
19,905
46.56
14,699.10
Minimum
Value
1,914
2.02
966
Maximum
Value
49 , 680
127.00
40,938
-------
Table V-70
FIRESIDE WASH WATER FLOWRATES
(308 Questionnaire Data)
Variable
Number Mean Standard Minimum Maximum
of Plants Value Deviation Value Value
Fuel: coal*
Flow: gpd/plant
gpd/MW
Fuel : gas*
M Flow: gpd/plant
C gPd/MW
Fuel : oil*
Flow: gpd/plant
gpd/MW
42
42
40
40
81
81
2,658
2.9
512
3.4
3,426
7
4,500
4.6
662
7
6,058
11.8
2.7
0.03
0.3
0.006
13.7
0.1
20,295
19
2,739
38.6
35,616
70
*Fuel designations are determined by the fuel which contributes the most Btu for
power generation in the year 1975.
-------
Table V-71
AIR P1EHEATER WASH WATER (1)
(Plant 3410)
COD (mg/1)
SS
TDS
Oil
pH
01
S04
Cond.
Hard.
Ca
Mg
Fe (soluble)
Ni
Or
Na
Zn
Case #1
50
34
733
.25
3.5
18.5
2,480
2,700
1 ,600
37.8
333
515
20.8
1 .45
360
1 .06
Case 92
70
83
606
8.5
3.2
16.6
1 ,920
2,700
1,400
29.4
257
335
18
1 .0
375
1 .19
Case #3
60
29
746
.25
3.3
27
2,720
3,250
1 ,460
34.4
330
460
34.8
1.25
368
1.45
216
-------
Table V-72
WASTE LOAD DATA FOR AIR PREHEATER WASH
(Discharge Monitoring Data - EPA Regional Offices)
(mg/1)
Pollutant
Suspended Solids
(78 entries)
Copper (77 entries)
Iron
Mean
Value
1,268.52
148.03
1,953.28
Standard
Deviation
1,663.14
815.37
2,023.79
Minimum
Value
40
0.1
0.05
Maximum
Value
10,211
6,000
8,250
-------
Table V-73
AIR PREHEATER WASHWATER FLOWRATES
(308 Questionnaire Data)
oo
Variable
Fuel:
Flow:
Fuel:
Flow:
Fuel:
Flow:
Coal*
gpd/ plant
gpd/MW
Gas*
gpd/ plant
gpd/MW
Oil*
gpd/plant
gpd/MW
Number
of Plants
148
147
56
56
110
110
Mean
Value
10,844.4
14.5
980.1
3.8
10,666.7
17.6
Standard
Deviation
22,234.04
31.8
1,922.8
6.2
50,872.6
62.2
Minimum
Value
2.7
0.01
0.27
0.002
1.4-
0.02
Maximum
Value
156,164.4
320.2
9,863
25.9
526,027.4
618.8
*Fuel designations are determined by the fuel which eontributes the most Btu for
power generation in the year 1975.
-------
2. Labor force and equipment required to maintain coal
storage area,
3. Cost of larger inventory, and
4. Loss in heating value of coal due to oxidative
degradation.
The quantity of runoff is dependent on the amount of rainfall. A
correlation developed by TVA to predict the runoff in inches per acre
for a given storm event when the total inches of rainfall are known is
given in equation 10 (44).
Runoff = 0.855 * Rainfall * 0.0082 (10)
The following generalizations may be made with regard to emergence of
contaminants in coal pile drainage (44): :
1. For a coal pile of a given size and configuration, the amount of
contaminants generated and flushed depends upon the residence time of
the water within the coal pile.
2. The time required to complete the flushing of contaminants from
the coal pile depends upon the volume of water applied (hydraulic
head) and the duration of the application.
3. Before flushing is complete, concentrations of contaminants are
inversely proportional to the flow rate of drainage runoff.
4. Upon completion of flushing, there is no significant change in
contaminant levels with changes in flow rate.
The contaminants and their respective amounts can be classified into
specific types according to chemical characteristics. The first type
relates to pH of the coal pile drainage. The pH tends to be of an
acid nature, primarily as a result of the oxidation of iron sulfide in
the presence of oxygen and water. The reaction is 'believed to occur
in two steps (20, 44). The products of the first step are ferrous
iron and sulfuric acid as shown in equation 11.
2FeSa + 702 + 2H20 # 2FeS04 + 2H4S04 (11)
The ferrous iron (Fea+) then undergoes oxidation to the ferric state
(Fe3+) as shown in equation 12.
4FeSQ* + 2H2SO* + 02 * 2Fe2(S04)3 + 2H*0 (12)
The reaction may proceed to form ferric hydroxide or basic ferric
sulfate as shown in equations 13 and 14, respectively.
Fez(SO«)3 + 6H20 ^ 2Fe(OH)3 + 3H2SO* (13)
Fe2(SO*)3 + 2H20 * 2Fe(OH(S04) + H2SO<, (14)
219
-------
The ferric iron can also directly oxidize pyrite to produce more
ferrous iron and sulfuric acid as shown in equation 15.
FeSj, + 14Fe+3 + 8H20 # ISFe+a + 2SO4~2 + 16H+ (15)
Thus/ the oxidation of one mole of iron pyrite yields 2 moles of
sulfuric acid.
As the pH of the pyritic systems decreases below 5, certain
acidophilic, chemoauto trophic bacteria become active. These bacteria,
Thiobacillus ferroxiduns, Ferrobacillus f erroxidans, Metal loqenium,
and similar species are active at pH 2.0 to 4.5 and use COZ as their
carbon source (45). These bacteria are responsible for the oxidation
of ferrous iron to ferric state, the rate limiting step in the
oxidation of pyrite. Their presence is generally an indication of
rapid pyrite oxidation and is accompanied by waters low in pH and high
in iron/ manganese, and total dissolved solids.
The potential influence of pH on the behavior of toxic and heavy
metals is of particular concern. Many of the metals are amphoteric
with regard to their solubility behavior. The factors affecting
acidity, pH and the subsequent leaching of trace metals are (44): |
1. Concentration and form of pyritic sulfur in coal;
2. Size of the coal pile;
3. Method of coal preparation and clearing prior to storage;
4. Climatic conditions, including rainfall and temperature;
5. Concentrations of CaC03 and other neutralizing substances in the
coal ;
6. Concentration and form of trace metals in the coal; and
•?. The residence time in the coal pile.
Table V-74 contains results of analysis of samples from coal piles at
two TVA plants. Both facilities exhibited very low pH values;
however/ the acidity values were quite variable in each of the cases,
which demonstrates that acidity is not a measure of hydrogen ion but
rather a measure of available protons. The suspended solids levels
observed went up to 2,500 mg/1 . Elevated levels of total suspended
solids result when rainfall/runoff suspends coal fires in the pile.
Most of the total dissolved solids concentrations are a consequence of
enhanced pyritic oxidation via equations 11-15. Table V-75 displays
data on the concentrations of metals in coal pile runoff from two TVA
plants. An examination of the data reveals that there is a large
degree of variability among the values. The metals present in the
greatest concentrations were copper, iron, aluminum, and nickel.
Others present in trace amounts include chromium, cadmium, mercury,
arsenic/ selenium, and berillium.
220
-------
Table V-74
CHARACTERISTICS OF COAL PILE RUNOFF (44)
Plant
J
E
E*
Range
Mean
N
Range
Mean
N
Range
Mean
N
El
2.3-3.1
2.79
19
2.5-3.1
2.67
6
2.5-2.7
2.63
14
Acidity
(mg/1
CaCO )
300-71 OQ
3400
18
860-2100
1360
6
300-1400
710
14
Sulfate
(mg/1)
1800-9600
51 60
18
1900-4000
2780
6
870-5500
2300
14
Dissolved
Solids
(mg/1)
2500-16000
7900
18
2900-5000
3600
6
1200-7500
2700
14
Suspended
Solids
(mg/1)
8.0-2300
470
18
38-270
190
6
69-2500
650
14
Fe
ipig/1)
240-1800
940
19
280-480
380
6
62-380
150
14
Mn
(mg/1)
8.9-45
28.7
19
2.4-10.0
4.13
6
0.88-5.4
2.3
14
*Discrete Storm
-------
Table V-75
CONCENTRATIONS OF METALS IN COAL PILE RUNOFF (44)
(mg/1)
Plant
Range
J Mean
ND*
N+ •
Range
0=24-0.46
E Mean
ra
K> M+
to "
Range
J Mean
ND*
N+
Range
E Mean
ND*
N-l-
Cu
0.43-1.4
0.86
0
19
0.01-0.46
0.23
0
6
Cr
<0.005-.011
.007
1 1
17
<0.005-.011
0.007
3
6
Zn
2.3-16 <
6.68
0
19
1.1-3.7
2.18
0
6
H&
<.0002-.0025
.0004
12
20
0.003-.007
0.004
0
5
Cd
.001-C001
<.001
19
19
<. 001-0. 003
0.002
2
6
As
.005-0.6
0.17
0
19
0.006-0.046
0.02
0
4
Al
66.0-440
260
0
19
22.0-60.0
43.3
0
6
Se
C001-.03
0.006
4
18
<.001-.001
0.001
3
4
Ni
0.74-4.5
2.59
0
19
0.33
0
6
Be
0.03-0.07
0.044
0
1-8
<. 01-0. 03
0.014
3
4
*Nft = Number of samples.below detection limits.
-------
Wet Flue Gas Cleaning Processes
•"•«—^i^««^••—••—^— ,
\
Flue Gas Desulfurization Systems
In 1977 there were approximately 34 powerplants in the United States
having operational FGD systems. In addition, 42 such systems were
under construction (49). The breakdown of existing, constructed, and
planned FGD systems by the type of process used for desulfurization of
the stack gases is given in table V-76.
In all of the existing FGD systems the main task of absorbing S02 from
the stack gases is accomplished by scrubbing the exiting gases with an
alkaline slurry. This may be preceded by partial removal of fly ash
from the stack gases. Existing FGD processes may be divided into two
categories: nonregenerable (throwaway) and regenerable.
Nonregenerable flue gas desulfurization processes include lime,
limestone, arid lime/limestone combination and double alkali systems.
The following is a short description of each process with
characterization, where applicable or available, of the liquid wastes
generated in the processes.
Nonregenerable Processes
Lime and Limestone Scrubbing Processes. In the lime or limestone flue
gas desulfurization process S02 is removed from the flue gas by wet
scrubbing with a slurry of calcium oxide (lime) or calcium carbonate
(limestone). The principal reactions for absorption of SO2 by slurry
are:
lime: SOj, + CaO + 1/2H20 -? CaSO3 . 1/2H20
limestone: SO2 + CaCO3 + 1/2H2O -? CaSO3 . 1/2H2O + CO2
Oxygen absorbed from the flue gas or surrounding atmosphere causes the
oxidation of absorbed SO2. The calcium sulfite formed in the
principal reaction and the calcium sulfate formed through oxidation
are precipitated as crystals in a holding tank. The crystals are
recovered in a solid/liquid separator. Waste solids disposal is
accomplished by ponding or landfill. The clear liquid can be
recycled.
A bleed stream is taken off the effluent hold tank to be dewatered.
This step, necessary to minimize the land area needed for sludge
disposal, varies depending on the application and type of disposal.
For systems with on-site pond disposal, solids may be pumped directly
from the effluent hold tank to the pond area. Clean overflow liquor
from the pond may then be returned to the system. :If necessary, a
thickening device such as a clarifier or centrifuge can be used to
increase the solids content. Additional dewatering to 60-70 percent
solids can sometimes be achieved by various systems including vacuum
filtration.
223
-------
Table ¥-76
SUMMARY OF NEW AND RETROFIT. FGD SYSTEMS BY PROCESS (49)
Operational
Proeaaa T7P«
Lisa
Lin«/allcaline tlyash
Lino/ 1 tee s con*
Limestone
Subcocal-lime/lir.escone
Aqueous
Aqueous earbonaca/fiab.
ftlctr
Double alkali
Magnesium oxide
Hoc solacced
Reganerablt noc selected
Sodiurn carbonata
W«llc»n Lord
Heltaen Lord/ Allied
Chemical
TOTALS
Line/lineacona I o£
total MW
Mew or
Recrotic
8
R
N
R
N
R
N
R
M
R
S
R
H
S
M
R
H
R
N
R
H
R
•H
R
N
R
S
R
M
R
N
R
Mo.
4
8
3
0
0
2
8
3
15.
13.
0
0
0
0
0
0
0
1
0
0
, 0
0
1
z
0
Q
1
1 ,
17.
17.
94
84
5W
2,450
1 ,650
1,170
o -
0
20
4,443
790
8,963.
2,46&.
0
0
0
0
0
0
0
120
0
0
0
0
125
250
0
0
375
115
8,563.
2,945.
Under
Construction
Mo.
10*
0
1
0
Q
0
23
..:,,„.
34.
1.
0
0
0
0
2
1
0
0
0
0
0
0
1
0
1
1
0
-„:. „
38.
4.
MN
4,565
0
500
0
0
0
9.620.
1 A??! 1
14.685.
425.
0
0
0
0
825
277
0
0
0
0
0
0
509
0
soo
180
0
.r:.140.;
16,,519,
1,222-
89
35
NO
0
2
1
3
0
0
5
-2
6
5
0
0
0
0
0
0
0
3
18
4
0
1
1
0
1
0
0
_0
26
13
Planned
. UN
0
660
527
579
0
0
2,880
0_
. • 3,407.
1,239.
0
0
0
0
0
0
0
726 '
9,500
2,100
0
650
125
0
500
0
0
_ o
. 13,532.
4,715.
25
26
Total. So.
of Planes
Ho.
16
10
7
3
0
2
45
5
68.
20.
0
1
1
0
2
1
0
4
19
4
0
1
3
2
2
1
1
A,
96.
36.
MM
8,440
2,310
3.597
579
0
20
21,726
1 ,790
33,763
4,699
0
100
400
0
825
277
0
846
9,800
2,100
0
650
759
250
1 ,000
180
375
455
46 , 922
9,557
72
49
R - racrofie
224
-------
or limestone systems typically recycle overflow water from the
thickener or settling pond. If all the overflow is recycled, the
system is a closed loop system (no discharge). Many of the lime or
limestone systems discharge scrubber waters usually to control
dissolved solids levels.
Another source of discharge not common to all systems is the mist
elimination wash. This involves the practice of either continuous or
intermittent wash of the demister vanes of the scrubber. Scrubber
slurry carryover (material carried from the contactor with the flue
gas) is retained in the system by impacting the demister section.
Cleaning of the demister is then accomplished by washing. The
resulting wash water is then either sent to the thickener, recycle
tank, or the settling pond. A summary of composition data for a
typical demister wash is presented in table V-77.
Double Alkali Wet Scrubbing. A number of processes can be considered
double alkali processes. In the United States,, most of the
developmental work has emphasized sodium-based double alkali systems
using lime for regeneration. Double alkali systems using an
ammonia/calcium ' base have been tested, but they suffer the
disadvantage of potentially producing a visible ammonium salt plume
from the scrubbing system. The following process description will be
limited to sodium/calcium-based processes.
/ / • ./
Flue gas is pretreated in a venturi or tray type prescrubber to cool
and humidify the gas and to reduce fly ash and chlorides. The
humidification and cooling step prevents the evaporation of excessive
amounts of water in the absorber. The potential for scaling and
plugging problems is reduced by the removal of fly ash which,
containing vanadium and iron compounds, can catalyze the oxidation of
'Na2O3 to Na2SO4.
Cool and humidified gas from the prescrubber passes through an
absorption tower, where SOZ is removed by absorption into a sodium
hydroxide or sodium sulfite scrubbing solution. The scrubber effluent
liquor is regenerated with lime or limestone in a reaction tank.
The calcium sulfite and calcium sulfate solids formed in the reaction
tank were withdrawn from the system in a solid/liquid separator.
After make-up alkali and water are added, the separator effluent
liquor is recycled to the scrubbing loop. A liquid purge stream is
required to remove soluble sodium sulfate. Failure to allow for
sulfate removal from double alkali systems will ultimately result in
(1) precipitation of sodium sulfate somewhere in the system if active
sodium is made up to the system; or (2) in the absence of makeup,
eventual deterioration of the SO2 removal capability due to the loss
of active sodium from the system.
Discharges From Non-Reqenerable Scrubbing Systems. All the non-
regenerable scrubbing systems have a disadvantage in that they produce
large amounts of throwaway sludges which may pose • problems in
disposal. Onsite disposal is usually performed by sending the waste
225
-------
Table V-77
COMPOSITION OF EFFLUENT ONCE-THROUGH MIST ELIMINATOR
WASH UNIT AT WET LIMESTONE SCRUBBER (50)
Water quality parameter
Acidity (methyl orange), as
Acidity (total), as CaC03, mg/1
Ammonia nitrogen, mg/1
Calcium, nig/1
Chloride, mg/1
Conductance, umho/cm
Dissolved solids (total), mg/1
Hardness as CaC03, mg/1
Magnesium, mg/1
pH, unit
Phosphate (total), mg/1
Potassium, mg/1
Sodium, mg/1
Sulfate, mg/1
Turbidity, JTU
Concentration at indicated wash rate
40.7 1/min/m2 20.35 1/min/m2 10.18 1/min/m2
49 - 120
64
0.21
220
24
1,300
1,000
580
6.5
3.1
0.11
2.2
8.1
700
<1
-
0.25
440
40
1,600
1,900
1,100
8.2
.
0.03
3
8.8
1,000
<1
150
0.34
430
120
2,700
2,200
1,100
18
2.7
0.03
2.6
11
1,200
2
-------
COMPOSITION OF
WASH UNIT
Water quality parameter
Aluminum, mg/1
Arsenic, mg/1
Bariuflf, mg/1
* I
Beryllium, mg/1
Cadmium, mg/1
Chromium, mg/1
Copper, mg/1
Cyanide, mg/1
Iron, mg/1
Lead, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Selenium, mg/1
Silver, mg/1
Zinc, mg/1
Table V-77 (Continued)
EFFLUENT FROM ONCE-THROUGH MIST ELIMINATOR
AT WET LIMESTONE SCRUBBER SYSTEM (50)
Concentration at indicated wash rate
40.7 1/min/m2 20.35 1/min/m2 10.18 1/min/m2
<0.2 <0.2 <0.2
0.002 0.002 OoOl
0.01
0.0042
<0.05
0.02
<0.01
5.8
0.033
0.16
<0.0002
<0.05
0.012
<0.01
0.07
<0.01
0.0013
<0.05
0.02
<0.01
0.07
0.011
0.14
-------
solids to a large pond. After settling, the supernatant from the
ponds may be recycled back into the scrubbing process. However, in
1977 only 6 of the total 34 plants (308 data) having operational FGD
systems reported closed loop mode of operation. Actual practices at
these facilities has not been confirmed at this time. Thus, the
supernatant from the majority of plants was directed to the surface
waters.
Table V-78 presents range of concentrations of chemicals in the
scrubber liquors before settling. Liquor analyses were conducted on
13 samples from seven powerplants burning eastern or western coal and
using lime, limestone or double alkali absorbents.
Wastewater Flows. Statistical analysis of wastewater flows from 28
powerplants indicating flue gas scrubber blowdown (308 data) is
presented in table V-79. It should be noted that the corresponding
question in the questionnaire reads "Flue Gas Scrubber Blowdown."
Statistical analysis of wastewater flows categorized as "Scrubber
Solids Pond Overflow" is presented in table V-80.
Regenerable Processes
Wellman-Lord Sulfite Scrubbing Process. The Wellman-Lord Sulfite
Scrubbing Process is a regenerable flue gas desulfurization process
marketed by Davy Powergas. It is based on the ability of a sodium
sulfite solution to absorb S02 and form a solution of sodium
bisulfite. The sodium bisulfite solution can be thermally regenerated
to produce a concentrated stream of SO2 and the original sodium
sulfite solution. The concentrated S02 stream can be processed to
produce elemental sulfur, sulfuric acid, or recycled to the absorber.
In the absorption phase of the process, sulfates formed by oxidation
of sulfites are removed from the system in a purge of sodium sulfate
and sulfite solids.
About 15 percent of the absorber product liquor is sent to purge
treatment. The product resulting from the purge treatment is a
chrystalline mixture of anhydrous sodium sulfate (70 percent) and
sodium sulfite (30 percent) with small amounts of thiosulfates,
pyrosulfites and chlorides. The supernatent liquor is recycled (51).
There is no planned wastewater or sludge streams associated with this
process.
Magnesia Slurry Absorption Process. The Magnesia Slurry Absorption
Process is a regenerable flue gas desulfurization process. S02 is
removed from the flue gases by wet scrubbing with a slurry of
magnesium oxide. Magnesium sulfite is the predominant species formed
in the absorption reaction below:
Mg(OH)2 + S02 •£ MgS03 + H2
The "absorber effuent is centrifuged. The liquor is sent to the slurry
tank for combination with makeup water, makeup MgO, and regenerated
MgO to form the slurry feed for the scrubber. The magnesium sulfite
228
-------
Table V-78
EANGE 0F CONCENTRATIONS OF CHEMICAL CONSTITUENTS IN FGD
SLUDGES FROM LIME/LIMESTONE, AND DOUBLE-ALKALI SYSTEMS (52)
Scrubb er .Cons tituent
Aluminum
Arsenic
Beryllium
Cadmium
Calcium
Chromium
Copper
Lead
Magnesium
Mercury
Potassium
Selenium
Sodium
Zinc
Chloride
Fluoride
Sulfate
Sulfite
Chemical oxygen demand
Total dissolved solids
PH
Liquor, mg/1
(except pH)
0.03-2.0
0.004-1.8
0.002-0.18
0.004-0.11
180-2,600
0.015-0.5
0.002-0.56
0.01-0.52
4.0-2,750
0.0004-0.07
5.9-100
0.0006-2.7
10.0-29,000
0.01-0.59
420-33,000
0.6-58
600-35,000
0.9-3,500
1-390
2,800-92,500
4.3-12.7
Solid, mg/kg
0.6-52
0.05-6
0.08-4
105,0.00-268,000
'10-250
8-76
0.23-21
0.01-5
2-17
-48,000
45-430
35,000-473,000
1 ,600-302,000
229
-------
Table V-79
FLUE GAS SCRUBBER SLOWDOWN
(308 Questionnaire)
Number
of Minimum
Variable Plants Mean Value Standard Deviation Value Maximum Value
Fuel; Coal*
Flow: GPD/plant 34 671,364.7 2,572,498.5 0.00 15,000,000
GPD/MW 34 811.27 1,877,799 0.00 8,823.53
to i
o *Fuel designations are determined by the fuel which contributes the most Btu for power
generation for the year 1975.
-------
Table V-80
FLUE GAS SCRUBBER SOLIDS POND OVERFLOW
(308 Questionnaire)
Variable
Fuel: Coal*
Number
of
Plants
Flow: GPD/plant 28
GPD/MH 28
Mean Value
210,724.6
3,973.31
Minimum
Standard Deviation Value
580,849.9
19,814.926
0.00
0.00
Maximum Value
2,310,000
195,000
*Fuel designations are determined by the fuel which contributes the most Btu for^power
generation for the year 1975. W
-------
cake is dried to remove free and bound water. Magnesium oxide is then
regenerated in a calciner by thermal decomposition of the magnesium
sulfite according to the equation below;
MgS03 •? - MgO + S02 f"
The concentrated SO2 gas stream can be used to promote sulfuric acid
or elemental sulfur.
Summary. In general, data sufficient to characterize waste loadings
resulting from flue gas cleaning processes are not available. No net
discharge data, i.e., influent and effluent data, are currently
available for those systems. Additional studies will be needed to
provide this data and to confirm the current discharge practices in
the industry.
232
-------
SECTION VI.
SELECTION OF POLLUTANT PARAMETERS
Section 502 of the Clean Water Act (I) defines; a pollutant as" follows;
The term "pollutant" means dredged spoil, solid waste,, incinerator
residue, sewage, garbage, sewage sludge, munitions-, chemical wastes,
biological materials, radioactive materials, heat, wrecked or
discharged equipment, rock, sand, cellar dirt and industrial,
municipal and agricultural waste discharged into water.
The selection of pollutant parameters for the 1974 Development
Document (2) was based on a list of 71 pollutant parameters published
by EPA (3) and supplemented by the following pollutant parameters:
- free available chlorine,
- polychlorinated biphenyls, and
. - pH.
The pollutant parameters selected and subsequently addressed in
the 1974 Development Document (2) werer
total solids,
total suspended solids,
total dissolved solids,
•
biochemical oxygen demand (BOD),
chemical oxygen demand (COD),
chlorine residuals,
alkalinity,
acidity,
total hardness,
fecal coliform,
surfactants,
oil and grease,
ammonia,
233
-------
- total phosphorous,
- phenols/
- sulfate/
- sulfite,
- flouride,
- chloride,
- -bromide/
- iron/
copper,
- mercury,
- vanadium/
- chromium/
- zinc/
- magnesium/ and
- aluminum.
The selection of pollutant parameters for this document is based on
the court approved list of 129 priority pollutants. The assessment of
the priority pollutants that may be discharged from steam electric
powerplants was based on the analytical results from the sampling
program, data from the 308 survey, and information published in the
literature. The priority pollutants detected in the sampling program
are listed in table VI-1 by waste stream source. Since the sampling
program did not include all the plants, pollutants which were not
detected at the sampled facilities may be discharged from other
facilities. Pollutants at or below the level of quantification may be
present at very low concentrations. The number of plants which
reported various priority pollutants as known or suspected to be
present in their waste streams are presented in table VI-2 by waste
stream source. In the 308 survey, powerplants were also requested to
provide information regarding proprietary chemicals used during plant
operations and their points of application. Table VI-3 provides a
listing of those proprietary chemicals, reported which contain one or
more of the priority pollutants. The specific priority pollutant
contained in each chemical was identified from the literature. The
addition of any proprietary chemical containing a priority pollutant
during operation of a plant would result in the discharge of that
pollutant in the plant's wastewater streams, thus, knowledge of the
chemical nature of proprietary chemicals and their point of
234
-------
Table VI-1
PRIORITY POLLUTANTS DETECTED IN THE SAMPLING PROGRAM BY
WASTE STREAM SOURCES
Priority Pollutant
Waste Stream Source
LO
Acenaphthene
Acrolein
Acrylonitrile
Benzene
Benzidene
Carbon Tetrachloride
Chlorobenzene
1,2,4-Trichlorobenzene
Hexachlorobenzene
1,2-Dichloroethane
1,1,1-Trichloroethane
Hexachloroethane
1,1-Dichloroethane
1 ,1,2-Trichloroethane
1,1,2,2-Tetrachloroethane
Chloroethane
Bis(Chloromethyl) Ether
Bis(2-Chloroethyl) Ether
2-Chlorbethyl Vinyl Ether
(Mixed)
2-Chloronaphthalene
2,4,6-Trichlorophenol
Parachlorotneta Cresol
Chloroform
2-Chlorophenol
1,2-Dichlorobenzene
1,3-Dichlorobenzene
Once
Through
Cooling
Water
0
0
0
X
0
0
0
0
0
0
X
0
0
0
0
0
0
0
0
X
0
0
X
0
X
0
Cooling
Tower
Blowdown
0
0
0
X
0
0
0
0
0
0
0
0
0
0
0
0
0
0
O
0
0
0
X
0
0
0
Combined
Ash
Sluice
Water
0
0
0
X
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
X
0
0
0
Bottom
Ash
Sluice
Water
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
6
Fly
Ash
Sluice
Water
0
0
0
0
0
0
0
0
0
0
X
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Low
Volume
Waste
0
0
0
X
0
0
X
0
0
X
X
0
0
X
0
0
0
0
O
0
0
0
X
X
X
0
Coal
Pile
Runoff
*
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
-------
Table VI-1 (Continued)
PRIORITY POLLUTANTS DETECTED IN THE SAMPLING PROGRAM BY
WASTE STREAM SOURCES
Priority Pollutant
Waste Stream Source
u>
1,4-Dichlorobenzene
3,3-Dichlorobenzidine
1f1-Diehloroethylene
1,2-Trans-Dichloroethylene
2,4-Dichlorophenol
1,2-Dichloropropane
1,3-Dichloropropene
2,4-Dimethylphenol
2,4-Dinitrotoluene
2,6-Dinitrotoluene
1,2-Diphenylhydrazine .
Ethylbenzene
Fluoranthene
4-Chlorophenyl Phenyl Ether
4-Bromophenyl Phenyl Ether
Bis(2-Chloroisopropyl) Ether
Bls(2-Chloroethoxy) Methane
Methylene Chloride
Methyl Chloride
Methyl Bromide
Bromoform
Dichlorobromomethane
Trichlorofluoromethane
Dichlorodifluoromethane
Chlorodibromomethane
Hexachlorobutadiene
Once
Through
Cooling
Water
0
0
X
0
X
0
0
0
0
0
0
X
0
0
0
0
0
X
0
0
X
0
0
0
X
0
Cooling
Tower
Slowdown
0
0
X
0
X
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
X
0
0
0
Combined
Ash
Sluice
Water
X
0
X
0
0
0
0
0
0
0
0
X
0
0
0
0
0
X
0
0
0
0
X
0
0
0
Bottom
Ash
Sluice
Water
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
Fly
Ash
Sluice
Water
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
X
0
0
0
0
0
0
0
0
Low
Volume
Waste
X
0
0
X
X
0
0
0
0
0
0
X
0
0
0
0
0
X
0
0
X
X
0
0
X
0
Coal
Pile
Runoff
*
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
-------
Table VI-1 (Continued)
PRIORITY POLLUTANTS DETECTED IN THE SAMPLING PROGRAM BY
WASTE STREAM SOURCES
Priority Pollutant
Waste Stream Source
Hexaehloroeyclopentadiene
Isophorone
Naphthalene
Nitrobenzene
2-Nitrophenol
4-Nitrophenol
214-Dinitrophenol
4,6-Dinitro-Q-Cresol
N-Nitrosodimethylamine
N-Nitrosodiphenylamine
N-Nitrosodi~N-Propylamine
Pentaehlorophenol
Phenol
Bis(2-Ethylhexyl) Phthalate
Butyl Benzyl Phthalate
Di-N-Butyl Phthalate
Di-H-Octyl Phthalate
Diethyl Phthalate
Dimethyl Phthalate
Benzo(A)Anthracene
Behzo (A) Pyr ene
Benzo(B)Fluoranthene
Benzo(K) Fluoranthene
Chrysene
Acenaphthylene
Anthracene
Benzo(G,H,I)Perylene
Once
Through
Cooling
Water
0
0
0
0
0
0
0
0
0
0
0
X
X
X
X
X
0
X
d
0
0
0
0
0
0
0
0
Cooling
Tower
Slowdown
0
0
0
0
0
0
0
0
0
0
0
0
X
X
0
0
0
0
0
0
0
0
0
0
0
0
0
Combined
Ash
Sluice
Water
0
0
0
0
0
0
0
0
0
0
0
0
X
X
0
0
0
0
X
0
0
0
0
0
0
o
0
Bottom
Ash
Sluice
Water
0
0
0
0
0
0
0
0
0
0
0
0
X
0
0
0
6
0
0
0
0
0
0
0
0
0
6
Fly
Ash
Sluice
Water
0
0
0
0
0
0
0
0
0
0
0
0
X
X
0
X
0
0
0
0
0
0
0
0
0
0
0
Low
Volume
Waste
0
0
0
X
0
0
0
0
0
0
0
0
X
0
X
0
X
0
0
0
0
0
0
0
0
0
0
Coal
Pile
Runoff
*
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
-------
Table VI-1 (Continued)
PRIORITY POLLUTANTS DETECTED IN THE SAMPLING PROGRAM BY
WASTE STREAM SOURCES
Priority Pollutant
Waste Stream Source
ro
W
oo
Fluorene
Phenanthrene
Dibenzo(A,H)Anthracene
Indeno(1,2,3,-C,D)Pyrene
Pyrene
Tetraehloroethylene
Toluene
Trichloroethylene
Vinyl Chloride
Aldrin
Dieldrin
Chlordane
4,4-DDT
4,4-DDE
4,4-ODD
Endosulfan-Alpha
Endosulfan-Beta
Endosulfan Sulfate
Endrin
Endrin Aldehyde
Heptachlor
Heptachlor Epoxide
BHC-Alpha
BBC-Beta
BHC(Lindane)-Gama
BHC-Delta
PCB-1242 (Arochlor 1242)
PCB-1254 (Arochlor 1254)
Once
Through
Cooling
Water
0
0
0
0
0
X
X
X
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Cooling
Tower
Slowdown
0
0
0
0
0
X
X
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Combined
Ash
Sluice
Water
0
0
0
0
0
X
X
0
0
0
0
0
0
0
X
0
0
0
0
0
0
0
0
0
0
0
0
0
Bottom
Ash
Sluice
Water
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
d
0
0
0
0
0
0
0
0
0
Fly
Ash
Sluice
Water
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
Low
Volume
Waste
0
0
0
0
0
V
A
X
X
0
0
0
0
0
0
X
0
0
0
0
0
0
0
0
0
0
0
0
0
Coal
Pile
Runoff
*
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
-------
Table VI-1 (Continued)
Ui
PRIORITY POLLUTANTS DETECTED IN THE SAMPLING PROGEAM BY
WASTE STREAM SOURCES
Priority Pollutant
Waste Stream Source
PCB-1221 (Arochlor 1221)
PCB-1232 (Arochlor 1232)
PCB-1248 (Arochlor 1248)
PCB-1260 (Arochlor 1260)
PCB-1016 (Arochlor 1016)
Toxaphene
Antimony (Total)
Arsenic (Total)
Asbestos(Total-Fibers/Liter)
Beryllium (Total)
Cadmium (Total)
Chromium (Total)
Copper (Total)
Cyanide (Total)
Lead (Total)
Mercury (Total)
Nickel (Total)
Selenium (Total)
Silver (Total)
Thallium (Total)
Zinc (Total)
2,3,7,8-Tetrachlorodibenzo-
P-Dioxin
Once
Through
Cooling
Water
0
0
0
0
0
0
X
* X
0
0
X
X
X
0
X
X
X
X
X .
X
X
Cooling
Tower
Slowdown
0
0
0
0
0
0
X
X
x
X
X
X
X
X
X
X
X
X
X
X
X
Combined
Ash
Sluice
Water
0
0
0
0
0
0
X
X
0
X
X
X
X
X
X
X
X
X
X
X
X
Bottom
Ash
Sluice
Water
0
0
0
0
0
0
X
X
O
X
X
X
X
0
X
X
X
X
0
0
X
Fly
Ash
Sluice
Water
0
0
0
0
0
0
X
X
0
X
X
X
X
0
X
X
X
X
0
X
X
Low
Volume
Waste
0
0
0
0
0
0
X
X
O
0
X
X
X
X
X
x
X
X
X
X
X
Coal
! Pile
Runoff
* .
0
0
0
0
0
0
0
0
O
X
X
X
X
0
X
0
X
0
0
0
X
0
0
0
0
0
0
0
Note:
X = Present in greater concentration in the effluent than in the influent at least once.
0 = Never present in greater concentration in the effluent than in the influent.
* = Since coal pile runoff has no influent stream (except rainfall), this column
reflects whether or not the pollutant was ever detected in the coal pile effluent
stream.
-------
Table VI-2
OF PLANTS REPORTING VARIOUS PRIORITY POLLUTANTS
AS KNOWN OR SUSPECTED TO BE PRESENT IN VARIOUS WASTE STREAMS
(308 questionnaire data)
Priority Pollutant
Acenaphten
Acrolein
Acryloni trile
Aldrin-dieldrin
Antimony and Compounds
Arsenic and Compounds
Asbestos
Benzene
Benzidine
Beryllium and Compounds
Cadmium and Compounds
Carbon Tetrachloride
Chlordane
Chlorinated Benzenes
Chlorinated Ethanes
Chlorinated Phenols
Chloroalkyl Ethers
Chloroform
Chromium and Compounds
Copper and Compounds
Cyanides
DDT and Metabolites
Dichlorobenzenes
Dichloroethylenes
Diphenylhydrazine
EDTA
Number of Plants Reporting by
Waste Stream*
1 .2 3 45 6
9
0
0
0
108
155
5
0
0
96
124
0
0
1
0 1
0
0
0
145
132
18
0
0
0
0
2
0
0
1
0
0
13
0
0
0
0
1
0
0
0
0
• o
0
0
4
38
0
0
0
0
1
7
0
0
0
0
3
2
0
0
0
0
3
0
0
0
0
7
0
1
40
8
0
0
0
0
0
6
0
0
0
0
0
2
32
2
0
1
0
0
1
1
20
1
0
0
3
9
0
0
0
0
0
6
0
0
0
0
0
11
9
0
0
0
8
0
0
0
0
0
0
0
43
76
0
0
0
0
0
0
0
0
0
0
15
36
4
19
0
15
25
9
0
0
2
1
0
19
45
69
12
0
0
0
0
39
240
-------
Table VX-2 (Continued)
NUMBER OF PLANTS REPORTING VARIOUS PRIORITY POLLUTANTS
AS KNOWN OR SUSPECTED TO BE PRESENT IN VARIOUS WASTE STREAMS
(308 questionnaire data)
Number of Plants Reporting by
Waste Stream*
Priority Pollutant 1 2 3 4 5 6
Flouranthene 000000
Haloethers 000000
Halomethanes 000000
Heptaehlor and Metabolities 0 0 0 00 0
Isophorone 1 00000
Lead and Compounds 132 9 3 12 8 37
Mercury and Compounds 137 11 2 13 0 43
Naphthalene 0 0 0 0 0 14
Nickel and Compounds 137 14 3 3 65 48
Nitrosamines 600000
PCBS 400200
Pentachlorophenol 109001
Phenol 5 6 2 1 2 19
Phthalate Esters 000001
Polynuclear Aromatic
Hydrocarbons 1 0000 0
Selenium and Compounds 120 0 20 1 20
Silver and Compounds 83 3 2 0 0 26
Tetrachloroethylene 0 00 10 0
Thallium and Compounds 34 0 2 0 0 2
Toluene 0 00 0 0 18
Trichloroethylene ' 000500
Vanadium 94 0 2 00 6
Vinyl chloride 0 0 0 01 0
Zinc and Compounds 142 7 22 9 59 49
241
-------
Table VI-2 (Continued)
OF PLANTS REPORTING VARIOUS PRIORITY POLLUTANTS
AS KNOW OR SUSPECTED TO BE PRESENT IN VARIOUS WASTE STREAMS
(308 questionnaire data)
Number of Plants Reporting by
Waste Stream*
Priority Polutant 1 23456
2-chlorophenol 00 0 00 0
2,4 Dichlorophenol 000000
2,4 Dimethylphenol 0 0 0 107
*Waste Streams:
1 - ash transport water
2 - water treatment wastes
3 - cooling system wastes
4 - maintenance wastes
5 - construction wastes
6 - other wastes
242
-------
. Table VI-3
PRIORITY POLLUTANT CONTAINING PROPRIETARY CHEMICALS*
USED BY POWER PLANTS
(308 questionnaire data)
Proprietary Chemical
(point ofapplication*)
NALCO CHEMICALS
25L (CT)*
37 (BW)
38 (CW)
75 (BW)
201 (CT)
344 (CT)
375 (CW)
425L(BW)
CALGON CHEMICALS
CL-70 (CT)
CL-35 (BW)
CL-68 (CW)
DEARBORN CHEMICALS
71 2 (CW)
BETZ CHEMICALS
BETZ 4OP (CW)
BETZ 403 (CW)
. DIANODIC 191 (CW)
DOW CHEMICALS
DOWICIDE GB (ALGACIDE)
HERCULES CHEMICALS
CR 403 (CT)
DUPONT -
KARMEX (CW)
Specific Priority Pollutant
Contained in Product (4,5)
COPPER
CHROMIUM
CHROMIUM
PHENOL
CHLORINATED PHENOLS
ACRYLONITRILE
CHROMIUM
COPPER
ZINC CHLORIDE
SODIUM DICROMATE
SODIUM DICHROMATE, ZINC CHLORIDE
CHLORINATED PHENOLS
CHROMATE AND ZINC SALTS
CHROMATE AND ZINC SALTS
CHROMATE AND ZINC SALTS
CHLORINATED PHENOLS
ZINC DICHROMATE, CHROMIC ACID
CHLORINATED PHENOLS
243
-------
Table VI-3 (Continued)
PRIORITY POLLUTANT CONTAINING PROPRIETARY CHEMICALS
USED BY POWER PLANTS
(308 questionnaire data)
Proprietary Chemical
(point of application*)
DREW CHEMICALS
BIOSPERSE 201 (CW)
ASHLAND CHEMICALS
1,1,1-TRICHLOROETHANE (FA)
BURRIS CHEMICALS
SODIUM DICHROMATE (CT)
Specific Priority Pollutant
Contained in Product (4,5)
CHLORINATED ETHANES
CHLORINATED ETHANES
SODIUM DICHROMATE
*Point of Application:
BW - BOILER WATER
CT - COOLING TOWER
CW - COOLING WATER
FA - FUEL ADDITIVE
244
-------
application was an additional way of identifying priority pollutants
in powerplant wastewater discharges.
At the time of the preparation of. this document, water quality
criteria for "the 65 families of toxic pollutants were not available.
Proposed criteria, however, were available for 27 of the pollutant
families. The criteria used are presented in table VI-4. Water
quality criteria are not an absolute constraint on effluent guidelines
development; they are one of many factors considered.
245
-------
Table ?I~4
WATER QUALITY AND HUMAN HEALTH CRITERIA USED IN ASSESSMENT
OF ENVIRONMENTAL SIGNIFICANCE OF POWER PLANT EFFLUENTS
(ppb)
to
Pollutant
Benzene
1,2-dichloroethane
2-chloronaphthalene
2,4,6-triehlorophenol
chloroform
1,2-dichlorobenzene
1,3-dichlorobenzene
1 ,4-dichlorobenzene
1,1-dichloroethylene
1,2-trans-diehloroethylene
2,4-dichlorophenol
methylene chloride
bromoform
chlorodibromomethane
2,4-dinitrophenol
pentachlorophenol
phenol
trichloroethylene
1,1,2,2-tetrachloroethane
ethylbenzene
isophorone
bromodichloromethane
tetrachloroethylene
WaterQuality Criteria
Freshwater
FT
3100
52
500
44
310
190
530
620
0.4
4000
840
6.2
600
1 50'0
310
FX
7000
150
1200
99
700
440
1200
1400
110
9000
1900
14
3400
3400
700
Marine
MT
920
620
15
22
15
1700
1900
180
3.7
38
97
79
MX
2100
1400
34
49
34
3900
4400
420
8.5
87
220
180
Human Health Criteria
15
2.1
270 Total
0.48
0.5
140
21
2.2
-------
Table VI-4 (Continued)
WATER QUALITY AND HUMAN HEALTH CRITERIA USED IN ASSESSMENT
OF ENVIRONMENTAL SIGNIFICANCE OF POWER PLANT EFFLUENTS
(ppb)
Pollutant
Water Quality Criteria
Freshwater Marine
FT FX MT MX
Human Health Criteria
antimony
arsenic
asbestos
chromium
copper
cyanides
^.mercury
~J nickel
selenium
silver
thallium
zinc
beryllium
cadmium
lead
57
130
29
7-10 35-400
FT=e exp (1 .24
-FX=e exp (1.24
FT-e exp (0.867
FX=e exp (1 .30
MT=1
MX=16
FT=e exp (1.51
FX=e exp (1 .51
48
67
5
0.3-15
1.4
0.003
2-100
9.7
0.009
280
3.5-60
42
3.2
45-600
22
1.9
25
0.88
0.089
4.4
0.26
260
2
1.6
10
0.58
110
In(hardness)-6.65)
ln(hardness)-1.46)
In(hardness)-4.38)
ln(hardness)-3.92)
ln(hardness)-3.37)
ln(hardness)-1 .39)
0.02
10
20
4
0.087
10
50
-------
248
-------
SECTION VII
TREATMENT AND.CONTROL TECHNOLOGY
INTRODUCTION
This section addresses treatment and control technologies judged to be
effective in reducing or eliminating pollutants from steam electric
power wastewaters. Wastewaters from steam electric powerplants vary
in both quality and quantity from one plant to another. Control of
pollutants, however, can be achieved in a uniform manner. The
treatment and control technologies described in this section are those
technologies which are available or currently in use in the steam
electric power industry to decrease the discharge of toxic pollutants
to navigable waters. The discussion of technologies is organized by
major waste streams and waste stream categories: cooling water, ash
handling, low volume wastes, metal cleaning wastes, and coal pile
runoff.
COOLING WATER
The variety of pollutants which may be present in cooling water
discharges from steam electric powerplants were identified in Section
V. In Section VI the major pollutants of concern were identified as
total residual chlorine (TRC) and certain priority pollutants.
The technologies which have been evaluated for control of TRC include:
- chlorine minimization,
dechlorination,
alternative oxidizing chemicals,
- mechanical cleaning,
- biocidal soak,
antifouling coatings,
heat treatment,
- gamma irradiation and ultraviolet radiation,
ultrasonic vibration,
- modified water velocity,
- osmotic shock, and
anoxic water.
EPA evaluated each of these technologies. Many were eliminated
249
-------
from further consideration for various reasons including:
- The technology was not believed to be applicable to a
large population of plants;
j . j
- The technology was judged to be too complex to be reliably
operated and maintained at a steam electric plant; or
No data was available to establish the effectiveness of
the technology in use at steam electric power plants or in
similar biofouling control applications. ;
The technologies chosen for full consideration were:
chlorine minimization,
- dechlorination,
- alternative oxidizing chemicals, and
- mechanical cleaning. ,
Several of the 129 priority pollutants have been observed in cooling
tower blowdown. The sources of these priority pollutants are chemical
additives used for corrosion, scaling, and biofouling control and
asbestos fill material from the cooling towers. The only feasible
technology for priority pollutant control is substitution of products
not containing priority pollutants for products that do contain these
pollutants. Chemical mixtures not containing priority pollutants can
be substituted for scaling and corrosion .control chemicals and non-
oxidizing biocides. Replacement of asbestos cement cooling tower fill
with another type of fill eliminates the release of asbestos fibers in
cooling tower blowdown.
A process description, an effectiveness evaluation, and a discussion
of the limitations for each of these technologies are presented in
this subsection.
Total JResidual Chlorine Control with Chlorine Minimization
Chlorine minimization is defined as any modification of a current
cooling water chlorination program that reduces to the minimum
possible level the loading of total residual chlorine (TRC) placed on
a receiving water by the once-throgh cooling water system of a steam
electric powerplant. Loading is the product of three factors:
cooling water flowrate, TRC concentration in the .cooling water
discharge, and the length of time TRC is present in the discharge.
Reduction of cooling water flow rate is not practical in a once-
through system; therefore, chlorine minimization can be accomplished
by reducing any of the following:
Dose of chlorine added; where dose is defined as the total
weight of chlorine added per unit volume of cooling water,
250
-------
i.e., 1 mg/1, 2 mg/1, etc./
- Duration of chlorination period; where duration is defined
as the length of time between the start and end of a
single period of chlorine addition; or
- Frequency of chlorination; where frequency is defined as
the number of times per day that chlorination periods
occur.
In addition, combinations of dose, duration and frequency may be
reduced simultaneously to bring about a reduction in net loading of
TRC to the environment.
Some plants add chlorine continuously in order to control biofouling
from barnacles or fresh water clams. Often a low dose of chlorine is
applied continuously for control of the hard shelled organisms—which
can close their shell and endure intermittent chlorination periods—
a.nd a higher dose is applied intermittently at some duration and
frequency for the control of biological slimes. Thus, plants which
chlorinate continuously may be able to apply chlorine minimization by
reducing their chlorine dose-for continuous chlorination—and reducing
their dose, duration or frequency for intermittent chlorination.
Chlorine minimization was considered only for plants with oncethrough
cooling water systems. For plants with recirculating systems, the
cooling towers as well as the condensers are susceptible to
biofouling. The need to control biofouling in the cooling towers not
only greatly complicates chlorine minimization but also increases the
risk of serious biofouling during a chlorine minimization program.
Description of a Chlorine Minimization Program
A chlorine minimization program as described here has three
components: upgrading the existing chlorination facility, conducting
a minimization study, and implementing the recommendations of the
study.
Upgrading Existing Chlorination Facility. An adequate chlorination
facility includes an equipment module, an instrumentation module, and
a structural module. ^
The equipment module contains the chlorine supply system. Two types
of chlorine supply systems are used; chlorine gas systems and sodium
hypochlorite generation systems. Sodium hypochlorite systems are
considerably more expensive than gas feed systems and have seen
limited application, primarily at plants which needed to avoid the
necessity for regular deliveries of chlorine gas cylinders, or at
plants where safety considerations suggested the use of a system,not
involving chlorine gas. Since the use of sodium hypochlorite.
generators is limited, the analysis does not consider these units
further; nevertheless, the concepts of chlorine minimization developed
251
-------
for gas feed chlorination systems can be similarly applied to
hypochlorite generation systems.
In gas feed chlorination systems, chlorine is manufactured offsite,
compressed in steel containers, and shipped to the plant site as a
liquid. Containers with a wide range of capacities are used.
Cylinder capacity commonly ranges from 150 pounds to 1 ton of
chlorine. Selection of container size is primarily a function of
average daily chlorine consumption. Selection of the number of
containers is primarily a function of facility design;capacity and
method of withdrawal (1). Generally, systems with a chlorine
withdrawal requirement of more than 17 pounds per hour per 1 ton
container use liquid withdrawal systems. Most steam electric
powerplants fall into this category. Some small plants may use gas
withdrawal systems.
Transmission of the chlorine from the containers to the metering
system differs for gas withdrawal and liquid withdrawal. For gas
withdrawal, the gas passes through a filter and, in some cases, a
pressure-reducing valve. The filter removes impurities in the
chlorine gas which might inhibit the functioning of some equipment in
the metering system. When there is a danger of reliquefaction of the
gas between the containers and the metering system, a pressure-
reducing valve is used to lower the pressure of the gas which, in
turn, lowers the temperature at which liquefaction would occur.
For liquid withdrawal, the liquid passes through an evaporator which
converts the liquid to chlorine gas and then the gas passes through a
filter and, in some cases, a pressure-reducing valve just as in gas
withdrawal. A flow diagram of a liquid withdrawal system is shown in
figure VII-1. The evaporator consists of an inner liquid chlorine
chamber surrounded by an electrically heated water bath. Expansion
chambers are usually provided on the liquid chlorine line between the
containers and the evaporator to prevent rupture of the pipe in the
event of capture of liquid in the line and subsequent temperature
rise. Whether gas or liquid withdrawal is used, chlorine gas enters
the metering system si'nce liquid is converted to gas during
transmission from the containers (1).
The metering system—usually referred toc as the chlorinator—is shown
in figure VII-2. The chlorinator is activated by a vacuum created by
the injector system. The vacuum opens the diaphragm check valve, the
vacuum regulating valve, and the pressure-vacuum relief valve which
allows air to enter the system. The vacuum also opens the gas
pressure regulating valve so that when the chlorine supply system is
opened, chlorine gas will flow through to the injector. When the gas
flow satisfies the vacuum, the pressure-vacuum relief valve closes,
stopping the flow of air into the system. The rate of chlorine gas
flow is controlled by the feed rate valve, and the vacuum-regulating
valve. By adjusting the feed rate valve, the flow of chlorine gas can
be limited to values less than the capacity of the rotameter.
252
-------
Ul
LEGEND:
IXJ
PIPE LINE SHUT-OFF
VALVE (GLOBE OR BALL TYPE)
FLANGE UNION (TONGUE
a GROOVE. AMMONIA TYPE!
LIQUID
CHEMICAL
EXPANSION TANK
PRESSURE SWITCH
DIAPHRAGM PflOTECTOfl (IF SWITCH
IS NOT EQUIPPED WITH SELF-
CONTAINED PROTECTION)
VENT
BLOW-OFF
VALV
PRESSURE
RELIEF
VALVE
AUTOMATIC
SHUT'OFF VALVE
(PRESSURE REDUCING
TYPE RECOMMENDED
RUPTURE DISC AND
INTEGRAL SUPPORT HOUSING
PRESSURE- SAUCE
DIAPHRAGM PROTECTOR
LIQUID CHEMICAL TRAP
(RECOMMENDED
LENGTH IS INCHESl
SUPERHEAT
BAFFLE
PRESSURE
VESSEL
LIQUID SUPPLY TO HEADER
(MINIMUM OF TWO SERVICE CONNECTIONS)
Figure VII-1
LIQUID SUPPLY CHLORINATION SYSTEM
Reprinted from Instruction Bulletin 70-9001 by Fischer and Porter Co., April, 1977
-------
-^OXIU KUV VUMt
Figure VII-2 |
SCHEMATIC DIAGEAM OF A TYPICAL CHLORINATOR
Reprinted from Handbookof Chlorination by G. C. White by per-
mission of Van tNostrand. Reinhold Company. Year of .first
publication: 1972.
254
-------
The last component of the equipment module is the injector system
which consists of a booster pump, an injector, and a diffuser. The
injector is the key component of the system. It is essentially a
constriction in the pipe carrying the water in which the chlorine gas
is dissolved. The constriction causes an increase in water velocity,,
thus creating the vacuum that activates the metering system. The
chlorine gas from the metering system enters the injector system at
this point and is dissolved in the water in the turbulent discharge of
the injector (1).
In order for the injector to operate properly, an adequate flow of
water at the proper pressure must be supplied by the booster pump.
The flow must be ample enough to limit the concentration of chlorine
in solution to 3,500 ppm and to create a vacuum of about 25 inches of
mercury. If the concentration of chlorine in solution exceeds 3,500
ppm, chlorine gas will come out of solution causing fuming at the
point of application and gas binding in the chlorine solution line.
If the vacuum falls below 25 inches of mercury, the metering system
will .not operate properly. The flow of water required to avoid these
problems can be determined from manufacturer's injector efficiency
curves. The pressure must be high enough to overcome the back
pressure on the injector and the pressure loss through the injector.
The back pressure on the injector is the sum of the static pressure at
the point of injection and friction losses in the piping between the
injector and the point of injection. The pressure loss through the
injector can also be determined from manufacturer's injector
efficiency curves. Given the required discharge volume and pressure,
the proper booster pump can be selected (1).
The hypochlorus acid solution from the injector is dispersed in the
cooling water with a diffuser. Two basic types of diffusers are
available. For pipelines flowing full, the diffusers are essentially
pipes mounted on the cooling water conduit perpendicular to the flow
of cooling water and discharging at the center of the conduit. Fpr
open channel flow, the diffusers are perforated pipes mounted in the
open channel. In steam electric powerplant applications, the open
channel condition exists when the hypochlorous acid solution is added
to the cooling water before it enters the circulating water pumps, and
the full pipeline condition exists when the hypochlorous acid solution
is added to the cooling water before it enters the condensers (1).
The instrumentation module consists of timers., a chlorine residual
analyzer/recorder, a scale, and a chlorine leak detector. Timers are
applicable to intermittent chlorination, not to continuous
chlorination. The timers automatically start and stop the booster
pump which in turn activates and deactivates the equipment module.
The timers are set so that chlorination occurs with the frequency and
duration • desired. The chlorine residual analyzer/recorder
continuously analyzes for total residual chlorine in the cooling water
discharge and overrides the timers to stop the booster pump if the
total residual chlorine concentration exceeds a predetermined level.
The scale is\ used to weigh the chlorine containers in service in order
to track consumption and to determine when containers need to be
255
-------
replaced. The chlorine leak detector monitors the air in the
chlorination building for chlorine gas and sounds an alarm if any of
the gas is detected (2).
The structural module consists of a building for the equipment and
instrumentation modules. The building must be properly ventilated and
heated. When 1 ton chlorine containers are being used, a hoist must
be provided with the building (1).
Chlorine Minimization Study. The chlorine minimization study consists
of three phases. The first phase establishes the following
relationships:
- condenser performance and dose of chlorine added to the
cooling water,
- condenser performance and duration of chlorination period,
and
- condenser performance and frequency of chlorination.
Condenser fouling is commonly measured in terms of turbine back
pressure. The second phase consists of screening trials in which the
chlorine residual in the cooling water discharge, the duration of the
chlorination events, and the frequency of the chlorination events are
each reduced below the baseline level until condenser performance
drops below the baseline levels. The screening trials define the
minimum chlorine dose, duration and frequency levels which can
maintain adequate condenser performance. The third phase is a long-
term trial of the chlorine minimization program defined in the second
phase. The minimum chlorine dose, duration, and frequency are
maintained and condenser performance is monitored. If performance is
satisfactory over the long term, the chlorine minimization program is.
instituted permanently (3,4,5).
Almost all of the data required to conduct the study are collected as
part of the normal operation and maintenance procedure in plants with
an adequate chlorination facility. The normal operation and
maintenance procedure for the chlorination facility includes daily
logging of the chlorine scale readings, daily logging of timer
settings, changing the chart on the chlorine residual analyzer, and
weekly checks of. the analyzer using an amperometric titrator. The
normal operation and maintenance procedure for the plant is assumed to
include daily logging of cooling water flow, changing charts on the
turbine back pressure recorder, and sampling and analysis of intake
water quality. The only data not collected as part of normal
operation and maintenance procedure is a qualitative evaluation of the
degree of biofouling in the condensers. A visual inspection of the
condenser can be conducted at the conclusion of each screening trial.
The inspection, however, requires taking the condenser out of service,
which is very costly in terms of lost power output from the plant.
256
-------
The performance data are analyzed. The analyses include correlating
intake water quality and chlorine demand, relating chlorine demand to
chlorine dosage, and plotting turbine back pressure/ TRC level,
duration of chlorination, and frequency of chlorination versus time.
The analyses are performed at different intervals for each phase of
the study. The frequency of analysis is greatest in the second phase
since the results of the analyses are used to operate the chlorination
facility.
The study procedure is applicable not only to a plant practicing
intermittent'chlorination but also to a plant practicing continuous
chlorination with the addition of a parallel set of steps to determine
the minimum dosage required to control biofouling in the intake
structure and the pipeline.
Implementing Study Recommendations. The final step in the chlorine
minimization program is implementing, the recommendations of the study.
Assuming that reductions in duration of chlorination, dose, or
frequency of chlorination are recommended, the minimum values become
the permanent basis of chlorination facility operation.
Application to a Model Plant
The model plant is assumed to have the following characteristics:
two baseload generating units of equal capacity;
- once-through cooling water system for both units;
- separate circulating water pumps for each unit;
same cooling water flow rate through the condensers of
each unit;
- chlorine addition on the intake side of the circulating
water pumps;
- chlorination of the units in series, not in parallel;
intermittent chlorination only;
- chlorination required during all seasons of the year;
- chlorination requirements varying with season of the year;
- existing chlorination equipment, structural, and
instrumentation modules; and
• •- in operation for several years sp that baseline levels of
chlorination are well defined.
As the first step in the minimization program, the existing chlo-
rination facility is evaluated. Assume that the existing equip-
257
-------
ment, structural, and instrumentation mcxtules are adequate.
The first phase of the study consists of establishing the fol-
lowing baseline relationships:
- water quality and chlorine demand of the cooling water,
- chlorine demand of the cooling water and dosage of
chlorine required to obtain'a given chlorine residual,
— condenser performance and chlorine residual in the
cooling water,
- condenser performance and duration of chlorination events,
and
- condensor performance and frequency of chlorination
events.
Condenser performance is measured by condenser back pressure or,
in some cases, turbine back pressure. In order to establish the
baseline relationships, the following measurements are taken with
the specified frequency:
- relevant intake water quality parameters once per week;
- chlorine demand of the intake water once per week;
- flow rate of cooling water to each unit once per week;
- weight of chlorine container(s) in use once per week;
- turbine back pressure once per shift;
- TRC at the plant discharge continuously, change chart on
recorder once per day;
- settings of timers that start and stop chlorination once
per day, and
- check of TRC analyzer once per week with an amperometric
titrator and adjustment of the analyzer, if necessary.
Each season, or once every 3 months, the data are analyzed as
follows: ;
- correlations between intake water quality parameters and
chlorine demand of the intake water are checked;
- the flow rate of cooling water pumped to each unit and the
consumption' of chlorine are used to calculate the chlorine
dosage;
- a graph of chlorine demand versus chlorine dosage is made;
258
-------
and
graphs of turbine back pressure, TRC level, duration of
chlorination, and frequency of chlorination versus time
are made. The unit, of time used should be 8 hours or one
shift.
Throughout the 18 month long study, screening trials are conducted.
Throughout all of the screening trials, the TRC level and frequency
and duration of chlorination for Unit 1 are maintained at the baseline
levels for the appropriate season of the year in order to detect any
shifts in the baselines. A visual inspection may be held at the end
of one or more of the screening trials.
The information from the visual inspections of the condensers is used
to qualitatively confirm the turbine back pressure readings. A set of
screening trials is conducted for each chlorination parameter: dose,
duration, and frequency of chlorination. The objective of each set of
trials is to converge on the minimum value for the parameter under
consideration. The other two parameters are held constant. The
procedure for conducting a set of screening trials is shown in figure
VII-3. The set of screening trials for TRC level are conducted first
using the baiseline levels for duration and frequency of chlorination
for the appropriate seasons of the year. After the minimum TRC level
has been determined, the set of screening trials for duration of
chlorination are conducted using the seasonally adjusted minimum TRC
level and the baseline level of chlorination frequency for the
appropriate season of the year. At the completion of this set of
trials, the set of screening trials for frequency of chlorination is,
conducted using the seasonally adjusted minimum TRC level and the
seasonally adjusted minimum duration of chlorination. When all three
sets of screening trials have been completed, the minimum values of
TRC level, duration of chlorination, and frequency of chlorination are
known.
The final step in the chlorine minimization program is implementing
the recommendations of the study. Assuming that the study recommended
reductions in TRC level, duration of chlorination, and frequency of
chlorination, the four sets of seasonal minimum values become the
permanent basis of chlorination facility operation. The .same
measurements which were made in the minimization study become part of
the data base on plant operation that is generated as standard
operating procedure. The analysis of the data is also assigned to the
plant operating staff with the assistance of appropriately designed
calculation sheets and graph paper. In essence, the chlorine
minimization program loses its identity in this final step as it is
completely integrated into the normal operation of the plant. A
detailed discussion of the necessary steps in conducting a chlorine
minimization program is provided in Appendix B.
259
-------
Figure VII -3 '_
PROCEDURE FOR CONDUCTING A SET OF SCREENING TRIALS
TO CONVERGE ON THE MINIMUM VALUE FOR TRC LEVEL,
DURATION OF CHLORINATION, AND CHLORINATION FREQUENCY
Sat TEC Level/Duration/Frequency at 1/2 of Baseline Value for Unit 2
Ploc Turbine Backprossure Readings Daily
Has Turbine Backpreasura Fallen Below the Baseline Level?
Ecs th« Staady-SCaca Biotouling
Condition Been Achieved
for tfiis Trial?
tea
Ses»t ISO
at Baseline Laval or Higher,
if necessary
Yes
Is Degree of Converganca on Mlnianim
Value of TE.C Level/Duraclon/
Frequency Maquata?
Inspect Condensers'for
Biofilm Accumulation
Plot Turbins Backpressure
Readings Daily
Has Turbine Backpregaura Risen
Co Baseline Level?
Redoes tha TRC Laval/Duracion/
Frequency Iron the Level in she
Pricaediag Trial by 1/2 ch«
in the Pracaeding Trial
,, fes
Inspect Condensers for Biofilm
Accumulation
Increase th« TRC Level/Duration/
Frequency from the Level in che
freceediog Trial- by 1/2 tha Level
la the Proceeding frial
260
-------
Effectiveness .
The objective of a chlorine minimization program is to reduce the
loading of total residual chlorine (TRC) into the receiving water as
much as possible without impairing condenser performance. The degree
to which this objective is achieved—'the effectiveness of chlorine
minimization—is measured in terms of the TRC level at "the point of
cooling water discharge and the length of time that chlorine is added
to the cooling water per day. Data on these two measures of
effectiveness were compiled from various studies of efforts to reduce
the quantity of chlorine discharged at operating powerplants. Very
little data from efforts to reduce the length of time that chlorine is
added to the cooling water were found. It should.be noted, however/
that the currsmt limitation was not exceeded in any of the studies.
An adequate amount of data from efforts to reduce TRC level was found,
therefore, an assessment of the effectiveness of chlorine minimization
was conducted by analyzing data on TRC levels only.
The TRC data which were extracted from the chlorine minimization and
reduction studies are presented in table VII-1. Twenty-two plants,
all with once-through cooling water systems, are represented. Seven
out of the 11 nuclear plants shown in table VII-1 were able to
maintain adequate biofouling control at plant discharge levels below
0,1 mg/1. The NEC studies were among the most carefully conducted; it
is believed they represent levels that should be achievable for many
fossil fuel plants.
A statistical evaluation of the effectiveness of chlorine minimization
at three Michigan power plants is presented in Appendix C. On the
average, the three plants were able to reduce their effluent TRC
concentrations by 40 percent through the use of a chlorine
minimization program.
Potential Operating Problems
A chlorine minimization program requires close monitoring by the
operating staff of a steam electric powerplant to insure that several
problems do not arise. First, the likelihood of severe, condenser
biofouling is increased. If this biofouling does occur, the condenser
has to be treated with very high dosages of chlorine or be taken out
of service for manual cleaning. Severe biofouling • is more likely
because there is no measure of condenser performance that
unambiguously reflects the formation of biofilm on condenser tubes.
The measure of condenser performance selected for the recommended
minimization program, turbine back pressure, is affected by factors
other than biofilm formation, principally, debris blocking the
condenser tubes. The other measures of condenser performance, heat
transfer efficiency and pressure drop across the condenser, are
similarly afflicted and require more data to calculate (5). Second,
the units on which screening trials are being conducted for the
minimization study have to be shutdown for visual inspection of the
condenser tubes at the end of each screening trial. The shutdowns
reduce the power output of the plant and require more operator time
261
-------
Table VII-1
TOTAL RESIDUAL CHLORINE DATA REPORTED IN CHLORINE MINIMIZATION
STUDIES
Recommended*
Plant TRC Level
Number (mg/1) Sampling Point
4223
0.5
4229
4225
5513
4704
1719
1713
1825
4206
0512
2630
5519
5514
1221
0905
3608
0904
2506
1248
0629
2705
2708
1.0
1.5
1.0
0.2
0.4
0.2
0.2
0.2
0.1
0.1
0.1
0.1
1.8
0.1
0.2
0.1
0.5
0.1
1.0
0.2
0.2
Condenser outlet
Condenser outlet
Condenser outlet
Condenser outlet
Condenser outlet
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Plant discharge
Comments
Condenser performance declined at
0.2, but not 0.5
Condenser performance declined at
0.5, but not 1 .0
Condenser performance declined at
1.0, but not 1 .5.
.Level frequently exceeded.
Level exceeded 73% of the time.
Level cannot be consistently met,
Six violations in three years
One violation in three years
Two violations in three years
Reference
6
6
6
. 3
7
8
8
9
10
11
11
11
11
11
11
11
11
11
11
11
12
13
*Recommended level represents the maximum TRC concentration expected to be used
during worst case plant conditions. Lower TRC levels often produce adequate
biofouling control.
-------
the shutdown and startup procedures. Unfortunately, no ot/ie,r
method of evaluating turbine back pressure readings is available (5);.
Some of the inspections may be required at times when the units arie
shutdown for other reasons, thus minimizing the impact of the
inspections. Third, the total residual chlorine measurements may bje
in error when the cooling water is drawn from an estuary. Errors to
the high side could cause, premature shutdown of the chlorination
facility and thus increase the potential for severe biofouling of the
condensers. Errors to the low side could create toxic conditions ijn
the receiving stream as a result of the chlorination facility not
shutting down when a predetermined level of TRC is exceeded.
The potential operating problems which have been mentioned should be
known to the operators of a plant before, a chlorine minimizatioin
program is begun so that the operators can deal with the problems as
effectively as possible.
Total Residual Chlorine Control with Dechlorination
Dechlorination is the process of adding a chemical-reducing agent to
the cooling water which reduces chlorine to chloride, a nontoxic
chemical. There are numerous reducing agents available for this
purpose. Only a few have shown themselves to be practical for use iln
the water and wastewater treatment industry (15):
1. Sulfur Dioxide (S02)
2. Salts Containing Oxidizable Sulfur
a. Sodium Sulfite (Na2S03)
b. Sodium Metabisulfite (Na2S2Qs)
c. Sodium Thiosulfate (Na2S203)
3. Natural Chlorine Demand
4. Ferrous Sulfate (FeS04)
5. Ammonia (NH3)
6. Activated Carbon (C) .
7. Hydrogen Peroxide (H202)
The use of ferrous sulfate, ammonia, activated carbon, or hydrogen
peroxide for dechlorination at powerplants has been evaluated and
found to be technically and/or economically infeasible (15). Any
dechlorination systems in which these chemicals are used were,
therefore, not given further consideration. Dechlorination systems
using sulfur dioxide, salts of oxidizable sulfur and natural chlorine
demand are discussed in detail in the following subsections.
Sulfur Dioxide System
263
-------
Chemical Reactions. The most common form of dechlorination as
practiced in the water and wastewater treatment industry is injection
of sulfur dioxide (S02) (1). When injected into water, sulfur, dioxide
reacts instantaneously to form sulfurous acid (H2S03):
S02 + H20 4- H2S03 (13)
The sulfurous acid, in turn, reacts instantaneously with hypochlorous
acid (HOC1):
H2SO3 + HOC1 «*• H2S04 + HC1 (14)
Monochloramine also reacts with sulfurous acid:
H2S03 + NH2C1 + H20 £ NH4HSO4 + HC1 (15)
Both dichloramine and nitrogen trichloride are also reduced by sulfur
dioxide in similar reactions. -The reaction of sulfur : dioxide with
hypochlorous acid (HOC1) is virtually instantaneous. Reactions with
monochloramine and the other combined forms proceed slightly more
slowly (16).
Equipment. The equipment required for dechlorination by sulfur
dioxide injection is shown in figure VII-4. As indicated in the
figure, a complete system includes the following pieces of equipment:
- S02 storage containers,
- expansion chamber-rupture disk,
- S02 evaporator,
- SO2 gas regulator,
- sulfonator,
- ejector;
- ejector pump,
- building for system housing, and
- required timers and control system.
The equipment required for dechlorination by sulfur dioxide injection
is identical to the equipment required for chlorination, and the
description of chlorination equipment is also applicable to the sulfur
dioxide dechlorination system. Equipment manufacturers sell the same
equipment for both chlorination and sulfur dioxide dechlorination
applications. The capacities of the equipment are different in each
application due to differences in the properties of the two gases.
Also shown in figure VII-4 is a typical diffuser assembly installation
in a discharge conduit. The number of diffuser installations"and the
264
-------
Ch
Ui
Chanber-
Rupture
Disk
"Electric SO,
Containers
Evaporator
Makeup Hater
Intake
Hater
Source
To additional
Discharge Conduit*
• Afl Required
Diffusers
Discharge Conduit
Structure
FIGURE VII - 4
FLOW DIAGRAM FOR DECHLORINATION BY SULFUR DIOXIDE (S02> INJECTION
-------
-------
pipe run required to each of the diffusers can vary significantly from
plant to plant. If- the water in the discharge conduit is in turbulent
flow, mixing of the injected solution should be complete in
approximately ten discharge conduit diameters. In some plants, this
length of pipe may not be available between the point at which sulfur
dioxide, can be injected and the point at which the effluent cooling
water enters the receiving source. Adequate mixing can be provided in
even these cases by the Use of multiple injectors which are
commercially available (17).
As stated earlier, the number of diffusers required and the length of
the pipe runs to each diffuser vary significantly from plant to plant.
Proper diffuser placement is essential for complete dechlorination.
In order to provide adequate time for mixing and reaction of the S0?
with the residual chlorine, it is desirable to locate the diffuser
assembly as far upstream from the point of final cooling water
discharge as possible. However, no biological fouling control can be
expected downstream of the diffuser assembly so in cases where
biofouling control is required in the discharge conduit (due to
presence of inollusks, asiatic clams, etc.), the diffuser should be
located as close to the point of final discharge as possible. In
theory, these two opposing constraints are balanced in determining the
location of the diffuser assembly. In reality, the location of the
diffuser assembly is often fixed by the location of the existing
access points in the discharge conduit. Installing the diffuser
assembly in an already existing access point (stop log guides, gate
shafts) is far less expensive than installing the diffuser assembly by
creating a new access point.
A second reason to dechlorinate as far upstream as possible is to
minimize the contact time of chlorine with organic matter in the
cooling water. Although the kinetics of the formation of chlorinated
organics has not been completely defined, it is likely that reducing
the chlorine-hydrocarbon contact time will reduce the formation of
chlorinated organics.
Chemical Consumption. The amount of S02 required to dechlorinate a
given cooling" water will vary from plant to plant. A stoichiometric
analysis of the sulfur dioxide-chlorine residual reaction reveals that
0.9 milligrams of sulfur dioxide are required to remove 1.0 milligrams
of residual chlorine (1). Actual operating experience at sewage
treatment plant suggests that a sulfur dioxide dose rate of 1.1
milligrams of sulfur dioxide per milligram of total residual chlorine
will result in proper system performance (16). As was discussed
earlier, the concentration of total residual chlorine in the cooling
water effluent will depend on the chlorine dose added and the chlorine
demand of the influent water. A high quality influent cooling water
will require only a small dose of chlorine to provide the
approximately 0.5 mg/1 of free available chlorine (FAC) that is
required to control biofouling in the condenser. Since a small dose
of chlorine was added to the cooling water to begin with, a small dose
of sulfur dioxide will be required for dechiorination.
267
-------
On the other hand, when a poor quality influent cooling water is used
(high ammonia concentration), a large chlorine dose will be required
to achieve the necessary amount of free residual chlorine. This large
chlorine dose may result in a high total residual chlorine
concentration which, in turn, would require a large dose of sulfur
dioxide to remove the chlorine residual.
In summary, high quality influent water will require small chlorine
doses and, in turn, small sulfur dioxide dosages. Low quality, high
ammonia influent cooling water is likely to require a high chlorine
dose and, therefore, a high sulfur dioxide dose.
Effectiveness. The effectiveness of sulfur dioxide dechlorination has
been demonstrated at water and wastewater treatment plants where the
technology has been in use since 1926 (17). Municipal treatment
plants are able to consistently reduce effluent TRC concentrations to
the limit of detection (0.02 mg/1 TRC). Of course, a sewage treatment
plant is generally dealing with a much lower water flow rate so that a
dechlorination contact basin may be used to insure adequate contact
time.
Sulfur dioxide dechlorination systems have also been installed or are
currently being installed in several United States steam electric
plants. A list of these facilities is shown in table VII-2. Plants
using both once-through and recirculating cooling water systems are
included. At Plant 0611, an involved study was done to determine the
effectiveness of dechlorination by sulfur dioxide injection (18).
This plant has a once-through cooling system using salt water.
Samples were collected from three streams in the plant: the
chlorinated condenser outlet, the unchlorinated condenser outlet and
the dechlorinated effluent from the S02 dechlorination system. The
data are presented in tables VII-3, VII-4 and VII-5. In all cases,
the total oxidant residual (TOR) in the dechlorinated effluent was
below the limit of detection of 0.03 mg/1. Total residual oxidants
(TRO), as compared to total residual chlorine (TRC), measures all free
oxidants because the bromine in salt water reacts upon chlorination to
form bromine residuals which are also active oxidizing compounds.
Amperometric titration does not distinguish between chlorine and
bromine residuals.
The sampling program conducted at Plant 0611 also included analysis of
samples for trihalomethahes. Samples were collected from the same
three streams as the TOR samples: the chlorinated condenser outlet,
the unchlorinated condenser outlet, and the dechlorinated final
effluent. The data indicate that chlorination of a once-through
brackish cooling water did result in very small but statistically
significant increases in total trihalomethane (THM) concentration.
The data also indicated that the dechlorinated effluents contained
smaller concentrations of THM's than the non-dechlorinated samples.
No mechanism for the decomposition of trihalomethanes by
dechlorination is known to exist; the lower THM concentrations in the
dechlorinated samples were attributed to sampling error. Thus,
268
-------
Table VII-2 •
SULFUR DIOXIDE! DECHLQRINATION SYSTEMS IN USE OR
UNDER CONSTRUCTION AT U.S. STEAM ELECTRIC PLANTS (23)
Plant Code
Plant 4251
Plant 4107
Plant 0611
Plant 0604
Plant
Capacity
(MW)
130
400
278
371.4
Cooling
Discharge
Type
Slowdown
Slowdown
Qnce-Thrti
Once-Thru
Cooling
Discharge
Flowrate
(MGD)
Not Available
Not Available
372.2x106
348.9x1O6
269
-------
Table VII-3
CHLORINATED CONDENSER OUTLET FIELD DATA
FROM PLANT 0611 (18)
Test
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Chlorine
Dose*
(mg/1)
0.85
0.82
0.85
0.83
0.72
0.83
0.81
0.81
0.80
0.80
0.80
0.81
0.87
0.87
0.87
0.87
0.88
0.89
0.88
0.85
0.85
0.82
0.85
0.42
0.85
0.81
0.81
0.83
TOR
(mg/1)
0.052
0.027
0.093
0.200
0.269
0.178
0.122
0.168
0.213
0.217
0.206
0.225
0.243
0.265
0.315
0.281
0.320
0.339
0.331
0.277
0.289
0.259
0.304
0.140
0.306
0.270
0.256
0.322
pH •
7.4
7.5
7.4
7.1
7.4
7.3
7.4
7.4
7.4
7.4
7.3
7.6
7.3
7. .6
7.5
7.6
7.6
7.4
7.0
7.6
7.6
7.5
7.6
7.7
7.7
7.7
7.7
7.7
D.O.
(mg/1)
3.9
3.7
4.9
4.7
5.4
5.0
5.8
5.5
5.4
5.4
5.4
7.0
5.4
5.5
5.1
5.2
4.8
5.1
5.0
5.3
5.4
5.0
5.0
5.3
5.4
5.0
, 5.4
5.2
^Calculatedbased on. ctilorine and cooling water flow rates.
270
-------
Table VII-4
UNCHLORINATED CONDENSER OUTLET FIELD DATA
FROM PLANT 0611 (18)
D.O.
Qns/1).
3.5
3.4
5.2
5.4
5.5
5.6
5.3
5.9
5.9
5.7
6.0
5.8
5.8
5.4
5.4
5.3
5.7
5.5
5.5
5.5
5.8
5.4
5.7 :
5.5
5.6
5.4 '
5.8
5.8
Test
No.
1
2
3
4
5
6
7
8 '
9
10
11
12
13
14
15.
16
17
18
19
20
21
22
23
24
25
26
27
28
TOR
(mg/1)
<0.03
<0.03
<0 . 03
<0.03
<0 . 03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
pH
7.6
7.3
7.5
7.4
7.2
7.4
7.4
7.4
7.4
7,4
7.4
7.0
7.4
7.5
7.5
7.7
7.7
7.4
7.7
7.7
7.6
7.6
7.7
7.7
7.7
7.6
7.7
7.7
271
-------
Table VII-5
DECHLORINATSD EFFLUENT DATA FIELD DATA
FOR PLANT 0611 (18)
Test
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
TOR
(mg/l)
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
pH
7.4
7.6
7.4
7.4
7.4
7.3
7.4
7.4
7.4
7.4
7.4
7.4
7.3
7.4
7.5
7.6
7.6
7.4
7.7
7.7
7.6
7.4
7.7
7.6
7.7
7.6
7.7
7.7
D.O.
(mg/l)
3.7
3,9
4.7
5.8
5.2
4.8
5.3
5.5
5.1
5.4
5.0
5.4
5.5
4.9
5.1
5.1
5.4
5.5
5.4
5.6
5.5
5.2
5.4
5.4
5.6
5.4
4.9
5.6
272
-------
dechlorination is not expected to have a significant effect on the THM
concentrations found in once-through cooling water effluent.
In summary, the available data indicate that state-of-the-art SO2
dechlorination systems can bring effluent TRC concentrations down to
the detection.limit (approximately 0.03 mg/1). Additional data will
be presented shortly on the effectiveness of dry chemical
dechlorination systems.
Potential Operating Problems. There are several potential operating
problems with sulfur dioxide dechlorination systems. First, since the
vapor pressure of sulfur dioxide is lower than chlorine at the same
temperature, the sulfur dioxide has a tendency to recondense in the
feed lines between the evaporator and the sulfonator. This problem
can be controlled by installing continuous strip electric heaters
along the feed line piping.
A second potential problem is pH shift in the effluent. The end
products of the reaction of sulfur dioxide with hypochlorous acid are
sulfuric acid and hydrochloric acid. Both these compounds tend to
lower the pH of the effluent water. Since the total dose of sulfur
dioxide is, in most cases, quite small and since the water usually has
some natural buffering capabilty, the pH shift is usually not
significant. A statistical analysis of the pH data collected from
each of the three streams at Plant.0611 (tables ViII-3, VII-4, and
VI1-5) did not indicate that S02 dechlorination was causing any
statistically significant change in pH.
Excess sulfur dioxide may also react with dissolved oxygen present in
the effluent cooling water. This could present a serious problem
since dissolved oxygen must be present in water in concentrations of
at least 4 mg/1 to support many kinds of fish. Sulfur dioxide
dechlorination has been practiced at wastewater treatment plants for
many years and dissolved oxygen depletion has not been a problem at
plants where proper sulfur dioxide dosage control has been practiced.
The data collected for dissolved oxygen levels at Plant 0611 (tables
VII-3, VII-4, and VII-5) do not indicate that any significant
depletion of dissolved oxygen is occurring due to SO2 dechlorination.
Although some problems exist with sulfur dioxide dechlorination
systems, it appears that, with proper equipment maintenance and good
process control, sulfur dioxide dechlorination offers an effective
method of reducing the discharge of residual chlorine from most
powerplants.
Dry Chemical Systems
Several sodium salts of sulfur can be used in dechlorination. These
compounds are all purchased in bulk volumes as dry chemical solids.
They will, therefore, be referred to hereafter by the generic term
"dry chemicals."
273
-------
Chemical Reactions. One of the dry chemicals commonly used is sodium
sulfite (Na2S03). Sodium sulfite reacts with hypochlorous acid as
shown in equation 16.
Na2S03 + HOC1 4*- Na2S04 + HC1 (16)
The stoichiometry of this reaction is such that 1.775 grams of sodium
sulfite are required to remove 1.0 gram of residual chlorine. Sodium
sulfite will also react with the chloramines.
A second dry chemical useful in dechlorination is sodium metabisulfite
(Na2S205) which dissociates in water into sodium bisulfite as shown in
equation 17.
Na2S205 + H20 -fr 2NaHS03 (17)
The sodium bisulfite then reacts with the hypochlorious acid as shown
in equation 18.
NaHSO3 + HOC1 •**• NaHS04 + HC1 (18)
Stoichiometrically, 1.34 grams of sodium metabisulfite are required to
remove 1.0 gram of residual chlorine. Sodium metabisulfite reduces
chloramines through a similar sequence of reactions.
The third commonly used dechlorination dry chemical is sodium
thiosulfate (Na2S203). It reacts with hypochlorus acid as shown in
equation 19.
Na2S203 + 4HOC1 + H20 •& 2NaHS04 + 4HC1 (19)
The stoichiometric reaction ratio is 0.56 grams of sodium thiosulfate
per gram of residual chlorine. Sodium thiosulfate will also reduce
chloramines. White (1) does not recommend the use of sodium
thiosulfate for dechlorination because it reacts through a series of
steps and requires significantly more reaction time than the other dry
chemicals. However, sodium thiosulfate has been used at full-scale
steam electric plants so it will be discussed here.
Equipment. The equipment required for dechlorination by dry chemical
injection is shown in figure VII-5. As indicated in the figure, a
complete system includes the following pieces of equipment (11):
loading hopper - dust collector unit,
- extension storage hopper,
- volumetric feeder,
- solution makeup tank and mixer,
- metering pump,
274
-------
Loading Hopper and
Oust Collector
Dry Cheaicsl Stored
On-nice in 100 Ib. bag*.
Manually loaded into
hopper.
Extension
Uopper
- Volumetric
Feeder
n
O tKl—
•C3 Presaure
Metering Relief
Pump Valve
C
Solution Makeup Tank and Miner
Control
Valve
To additional
Discharge Condulta
A» Required
-tfa-
Diacharge
Conduit
Structure
Figure VII-5
FLOW DIAGRAM FOR DECHLORINATION BY DRY CHEMICAL INJECTION
-------
- pressure relief valve, and
- required timers and control system.
Also shown in figure VII-5 is a typical diffuser assembly installation
in a discharge conduit.
The chemicals are typically received and stored in 100-pound bags.
When necessary, bags are opened and manually dumped into a loading
hopper dust collector unit. An extension storage hopper is provided
so that bags of chemical need only be loaded on a periodic basis. A
volumetric feeder then adds the chemical at a preselected rate into a
solution mixing tank. The chemical is mixed with water to form a
solution which is then pumped by a metering pump to the required
points of injection. If the water in the discharge conduit is in
turbulent flow, mixing of the injected solution should be complete in
approximately 10 discharge conduit diameters. The dechlorination
reaction is generally very rapid but the rate can vary significantly
depending on which dry chemical is used. All of the points made
earlier about the location of the point of sulfur dioxide injection
apply to the point of dry chemical injection. The same is true for
the relationship between influent water quality and the required dose
of dechlorination chemical.
Effectiveness. Dry chemical injection systems have been or are
currently being installed at a number of United States steam electric
plants. A list of these facilities is shown in table VII-6.
Additional data on the operational practices applied at three of these
plants is provided in table VII-7.
These three plants were selected for detailed statistical analysis of
their effluent TRC levels over a period of two years. During the two
year period, three different chlorination programs were in effect, as
follows:
No Controls - 1/77 through 5/77
Chlorine Minimization - 6/11 through 10/77
Dechlorination - 11/77 through 12/78
Thus, dechlorination data from discharge monitoring reports (DMR's)
are available for each of the three plants (2603, 2608, 2607) for a
period of slightly over one year. As detailed in Appendix C, the
dechlorination data were analyzed to determine the 99th.percentlie of
the distribution of daily effluent TRC concentrations. The analysis
found 0.14 mg/1 TRC to be the concentration below which 99 percent of
all grab samples taken during periods of simultaneous chlorination and
dechlorination would fall. It is concluded that dry chemical
dechlorination can effectively limit the discharge of TRC to
concentrations of 0.14 mg/1 or lower with 99 percent reliability.
It is important to note that the dry chemical dechlorination systems
in use at Plants 2603, 2608, and 2607 are all "make-shift" systems.
The equipment used is generally a 55 gallon drum (used as a mix tank)
276
-------
' Table VII-6
DRY CHEMICAL DECHLORINATION SYSTEMS IN USE OR
CONSTRUCTION AT U.S. STEAM ELECTRIC PLANTS* (23)
Plant Code (Capacity)
Plant 5513 (272 MWe)
Plant 2601 (615 MWe)
Plant 2607 (325 MWe)
Plant 2608 (510 MWe)
Plant 2623 (34 MWe)
Plant 2603 (1135 MWe)
Cooling System
Once-thru
Once-thru
Once-thru
Once-thru
Once-thru
Once-thru and
Recirculating
Agent
Sodium bisulfite
Sodium sulfite
Sodium thiosulfate
Sodium sulfite
Sodium bisulfite
Sodium sulfite and
Sodium thiosulfate
*In some cases, temporary make shift units were used.
277
-------
Table VII-7
CHiORINATION/DECHLORINATION PRACTICES (23)
Practice
Deehlorination
Chemical
Dose of dechlo-
rination chemical
fed per chlorina-
tion period
(concentration)
Chlorination
,0 Chemical
oo
Dose of chlorina-
tion chemical fed'
per chlorination
period (concentra-
tion of available
chlorine)
Flow rate of
discharge
Reaction time
condenser outlet
to headwall)
Plant 2603
Sodium Sulfite
Sodium Thiosulfate
winter ,9ppm
summer .9 ppm
Chlorine Gas
winter .22 ppm
summer 1.06 ppm
150,000 gpm
calculated-5 min,
actual-4.5 min.
Plant 2608
Sodium Sulfite
winter .07 ppm
summer .2 ppm
Plant 2607
Sodium Thiosulfate
winter .14 ppm
summer .3 ppm
Sodium Hypochlorite Sodium Hypochlorite
winter .04 ppm
summer .11 ppm
winter .22 ppm
summer .22 ppm
405,000 gpm
214,000 gpm
calculated-1-2 min. calculated-6 min.
-------
with a pump and a hose leading to the condenser outlet. Thus, tne
apparatus constitutes a minimum of sophistication. It would follow
therefore, that properly designed and instrumented dechlorination
systems should be capable of achieving much better performance, as
demonstrated "in other data presented in this section. The data from
Plant 0611 (tables VII-3, VII-4, VII-5) which has. a properly
instrumented S02 dechlorination system supports this conclusion. TRC
levels in the final effluent from Plant 0611 were consistently below
the level of detection.
Potential Operating Problems. Potential problems with dry chemical
dechlorination systems include pH shift, and oxygen depletion. Table
VI1-8 presents pH data from four powerplants with dry chemical
dechlorination systems. In these four plants, pH shift was not
significant and may have been within the error limits of the
instrumentation.
Table VI1-9 presents additional data from the same four plants using
dry chemical dechlorination. The data indicate that dissolved oxygen
depletion in the effluent cooling water is not a problem. In no case
was the dissolved oxygen lowered by more than 0.6 mg/1.
In summary, dry chemical dechlorination is an effective method of
reducing the discharge of residual chlorine from powerplants. Good
process control and proper equipment maintenance are necessary for the
system to perform optimally.
Dechlorination by Natural Chlorine Demand
Another form of dechlorination does not require the injection of a
reducing agent but, instead, makes optimal use of the reducing
compounds naturally present in raw water. These natural dechlo-
rinating agents include all the components of the chlorine demand
except ammonia.
Once-Through Cooling Systems. Dechlorination by natural chlorine
demand is applied differently for once-through and recirculating
plants. In once-through plants the technology essentially consists of
placing the point of chlorine injection directly in front of or inside
of the condenser inlet box. In an existing plant, this often involves
moving the current points of injection from the suction (low pressure)
side of the cooling water circulating pumps to the new location near
the condenser inlet box (where the water is at high pressure). In a
new plant, the chlorination system can be designed to feed into or
near the condenser inlet box from the start.
Feeding the chlorine into or near the condenser inlet box may offer
any of three distinct advantages depending on plant design. First,
less reaction time with the natural chlorine demand of the cooling
water will be available before the cooling water reaches the condenser
tubes where biofouling control is required. This is because the
residence time between the traditional point of chlorine injection—
the suction side of the cooling water pumps— and the new point of
279
-------
Table VII-8
EFFECT OF DRY CHEMICAL DECHLORINATlCl
ON PH OF THE COOLING WATER
(EPA Surveillance and Analysis Regional Data)
EH
Plant Code Intake Chlorinated , Dechlorinated
2603 8.0 8.4 7.2
2608 7.5 8.1 7.9
2607 8.0 7.9 8.0
5513 7.3 7.3 7.2
280
-------
Table VII-9
''"EFFECT OF DRY CHEMICAL DECHLORINATION ON
DISSOLVED OXYGEN IN COOLING WATER
(EPA Surveillance and Analysis Regional Data)
Pi s s oIved Oxygen(mg/I)'
Plant Code
2603
2608
2607
5513
Intake
5.8
8.1
7.0
2.2
Chlorinated
NA
NA
NA
2.1
Dechlorinated
7.2
7.5
6.6
1.9
NA - Data not available.
281
-------
chlorine injection—into or near the inlet condenser box—has been
eliminated. A shorter residence time means less of the free chlorine
will react with ammonia—to form chloramines of low biocidal activity-
-and less of the free chlorine will react with other chlorine demand
compounds—to form compounds containing no residual^chlorine and
having little or no biocidal activity. Since less of the free
chlorine is being lost to chlorine demand reactions before reaching
the condenser tubes, a lower dose of chlorine will be required to
achieve the same concentration of free available chlorine in the
condenser tubes. Thus, moving the point of chlorine injection may
allow a reduction in the chlorine dose required to maintain adequate
biofouling control. For this reason, some reports have referred to
moving the points of injection as a chlorine minimization technique.
The definition of chlorine minimization contained in this document
does not include moving the points of injection.
The second major advantage of locating the points of injection at or
near the condenser inlet box is that chlorination can then be done
sequentially; each condenser or condenser half is chlorinated by
itself, one at a time. The effect of chlorinating sequentially is to
provide non-chlorinated water for dilution of the chlorinated water
stream. Figure VII-6 illustrates a hypothetical powerplant cooling
water system; the points of chlorine injection (before and after the
movement of the points) are shown. In this example, there are two
condensers, each is split into two separate halves. If the cooling
water flow rate through each of the condenser halves is equal, then
only one quarter of the cooling water flow will be chlorinated at any
one time; three quarters of the flow is available for dilution. From
simple dilution then, the concentration of residual chlorine in the
final discharge effluent will only be one quarter of the concentration
present in the exit line from the chlorinated condenser half.
The third major advantage of locating the points of chlorine injection
at or near the condenser inlet box is that the nonchlorinated water
being used for dilution will also bring about some dechlorination due
to the presence of natural chlorine demand compounds in the
unchlorinated water. The extent to which dechlorination removes the
remaining free chlorine (after dilution) is a function of the quality
of the cooling water and the residence time in the cooling water
discharge conduit. Any chloramines formed by reaction , of chlorine
with ammonia will not be decomposed by any of the natural chlorine
demand compounds so some residual chlorine will still be present in
the final effluent.
In summary, the application of dechlorination by natural chlorine
demand in once-through cooling water systems—moving the points of
chlorine injection—offers three potential advantages:
1. Less natural dechlorination before the condenser.
2. More unchlorinated water available for dilution.
282
-------
DO
CO
SHORELINE
BOUNDARY
OLD CHLORINE INJECTION LINE;
ONE CONTROL VALVETv
COOLING WATER
INTAKE SOURCE
INDIVIDUAL TIMERS AND
CONTROL VALVES; EfcfiH
LINE OPERATES AT A \
DIFFERENT TIME
INTERVAL
} *-
1
J
1
1
CONDENSER #la
CONDENSER #lb
COMMON DISCHAKU£
CONDUIT •*
^~~ 1 '.
-^ "I....
IT !.
T.f —
"" CONDENSER #2a
CONDENSER jf2u
'
•IEOUSLY
CHLORINATIO
BUILDING
: ! b-
1
_ I
Jr
N
1 |
>-
\
NEW
CHLORINE
INJECTIOb
LINES
i i i I I
1
8
1
$
1
1
1
2
1
J
3
1
TO FINAL POINT
OF DISCHARGE
FIGURE VII - 6
DECHLORINATION BY NATURAL CHLORINE DEMAND
IN A ONCE - THROUGH COOLING WATER SYSTEM
OLD
CHLORINE
SOLUTION
DIFFUSERS
INTAKE
SCREENS
PUMP
HOUSE
PUMPS
-------
3. Some natural dechlorination after the cooling water exits the
condenser outlet box.
Recirculatinq Cooling Systems. In recirculating cooling systems, the
application of dechlorination by natural chlorine demand consists of
simply modifying the chlorination procedure currently in use at the
plant such that blowdown is not discharged during the chlorination
period nor during the period of time after chlorine addition stops
that residual chlorine is still present in the recirculating cooling
water. Once chlorine addition ceases/ the natural chlorine demand
reactions will bring about a rapid reduction in the residual chlorine
concentration present in the recirculating stream. For example, in a
study conducted at Plant 0609, it was found that the total residual
chlorine concentration in the recirculating water of a cooling tower
dropped to zero one and one' half hours after chlorine dosage was
ceased (20). A program of chlorination was adopted such that the
cooling tower blowdown valve was closed during the period of
chlorination and left closed for the*following three hours. A three
hour no-blowdown time period was selected in order to insure complete
degradation of the total residual chlorine present in the recir-
culating cooling water. . It is expected that this same kind of
operation procedure could be, successfully applied to recirculating
cooling systems using cooling ponds or canals.
Effectiveness. The effectiveness of dechlorination by natural
chlorine demand is extremely site specific. For once-through plants,
three factors will tend to increase the effectiveness:
1. The longer the residence time between the present points of
chlorine addition and the new points of addition, the more reaction
time will be eliminated by moving the points; thus,;the larger a
reduction in chlorine loss to pre-condenser demand reactions.
2. The larger the number of condensers and the larger the plant
megawatt capacity, the more unchlorinated water will be available for
dilution, provided all the condenser exit streams are combined before
final discharge.
3. The higher the chlorine demand (except ammonia) of the raw cooling
water, the more dechlorination will occur upon combination of the
chlorinated condenser exit stream with the nonchlorinated streams.
In recirculating cooling systems the following factors play a role in
determining the effectiveness of this technology: . the amount of
chlorine demand in the makeup water, the amount of sunlight entering
the tower, and the quality of the air being scrubbed by the tower.
If the implementation of dechlorination by natural chlorine demand is
possible at a given plant, there may be very substantial economic
advantages to using this technique as opposed to either of the two
other dechlorination methods.
,284
-------
Potential Operating Problems. Two potential operating problems are
immediately apparent when considering dechlorination by natural
chlorine demand. First, in once-through cooling systems, there may be
a need for biofouling control in the inlet cooling water tunnel(sj.
If the points^of chlorine injection are moved from the entrance to the
cooling water tunnels to the condenser inlet box, there may be a
problem with biofouling in the inlet cooling water tunnels.
Secondly, in recirculating cooling systems, it may not be possible to
shut the blowdown valve for long periods of time on the order of
several hours due to the system hydraulic .characteristics. This is
especially likely to be a problem in large plants using cooling towers
where the blowdown flow rate may be on the order of several million
gallons per day.
Total Residual Chlorine Control Through Alternative Oxidizing
Chemicals -
Oxidizing chemicals, other than chlorine, which have been proposed for
biofouling control include:
chlorine dioxide,
bromine,
- ozone,
bromine chloride, and
iodine.
Substitution of the chemicals for chlorine would reduce or eliminate
TRC in the cooling water discharge. These chemicals were evaluated
and only chlorine dioxide, bromine chloride, and ozone were selected
for further consideration.
Chlorine Dioxide
Chlorine dioxide is a gas under standard conditions. At concen-
trations exceeding 15 to 20 percent, gaseous chlorine dioxide is
unstable and, therefore, not suitable for handling in bulk form. As a
result, chlorine dioxide is generated on site.
Facility Descriptions. Two methods, the chlorine gas method and the
hypochlorite method, are commonly used.
When chlorine gas is dissolved in water, hypochlorous acid and
hydrochloric acid are formed:
C12 + H20 .# HOC1 + HC1 . (20)
This is the reaction that occurs in the injector of a chlorination
system. The chlorine dioxide biofouling control facility takes the
285
-------
chlorinated water stream from the injector and passes it through a
packed column in which it reacts with a sodium chlorite solution to
form chlorine dioxide:
HOC1 + HC1 + 2NaCl02 * 2C102 + 2NaCl + H20 "(21)
The resulting chlorine dioxide solution then enters the cooling water
through a diffuser.
A simplified, schematic diagram of a chlorine dioxide biofouling
control facility based -on the chlorine gas generation method is
presented in figure VII-7. The facility contains a complete
chlorination system as described in the chlorine biofouling control
facility section. In addition, the facility includes a sodium
chlorite solution storage container, a metering pump for the sodium
chlorite solution, and the packed column. The major component of the
chlorine dioxide facility is the chlorination system.
The feed rate of chlorine dioxide to the cooling water is controlled
by adjusting the feed rates of the chlorine gas and the sodium
chlorite solution to the packed column. The feed rate of chlorine gas
is controlled by the chlorinator in the chlorination system. The feed
rate of the sodium chlorite solution is controlled by the metering
pump. Since the flow of water through the packed column is provided
by the booster pump in the chlorination system, the flow remains
constant; therefore, changes in the feed rates of chlorine gas and
sodium chlorite solution result in changes in the concentration of
chlorine dioxide gas in the water entering the diffuser.
When sodium hypochlorite is dissolved in water, hypochlorous acid and
sodium hydroxide are formed:
NaOCl + H20 * HOC1 + NaOH (22)
Reaction of the hypochlorous acid with a sodium chlorite solution
produces chlorine dioxide: ;
2HOC1 + 4NaC102 + H2S04 -? 4C102 + Na2SO4 + 2NaCl + 2H20 (23)
The sodium hydroxide formed in the reaction represented by equation*22
raises the pH of the solution above the optimum for the reaction in
equation 23; therefore, sulfuric acid is added to the reaction
represented by equation 23 to lower the pH. The reactions in
equations 22 and 23.are the basis of the hypochlorite method.
A simplified, schematic diagram of a chlorine dioxide biofouling
control facility based on the hypochlorite generation method is
presented in figure VI1-8. A side stream of cooling water is pumped
to a packed column. Sulfuric acid and sodium hypochlorite are added
by metering pumps to the water in.the pipe between the pump and the
column; thus, the rea'ction in equation 22 has occurred and the pH is
at the optimum for the reaction in equation 23 when the water reaches
the column. At this point, a sodium chlorite solution is added by a
286
-------
CL02 SOLUTION TO
COOLING WATER
PACKED
COLUMN
SODIUM
CHLORITE
SOLUTION
CHLORINATED WATER
CHLORINATION
SYSTEM
I
5
Ti
Figure VII-7
Simplified, Schematic Diagram of a Chlorine Dioxide Biofouling Control Facility
Based on the Chlorine Gas Method (21)
287
-------
CL02 SOLUTION
"fO COOLING WATER
PACKiD
COLUMN
COOLING
WATER
SIDESTREAM
SODIUM
CHLORITE
SOLUTION
SODIUM
HYPOCHLOR1TE
SULFURIC
ACID
Figure VII-3
Simplified, Schematic Diagram of a Chlorine Dioxide Biofouling Control Facility
Based on the Hypochlorite Method (21)
288
-------
metering pump to the water, and the reaction in equation 23 occurs in
the column. The resulting chlorine dioxide solution enters the
cooling water through a diffuser. The feed rate of chlorine dioxide
to the cooling water is controlled by adjusting the feed rate of the
sodium hypochlorite and sodium chlorite solution metering pumps.
Effectiveness. The substitution of chlorine dioxide for chlorine in
biofouling control should eliminate all total residual chlorine in the
cooling water; however, the addition of excess chlorine in the
generation of chlorine dioxide to insure maximum yield could create a
total chlorine residual in the cooling water. The determination of
the presence or absence of this residual and the concentration if the
residual is present, is not possible. All of the methods of
determining total residual chlorine are based on the oxidizing power
of both free and combined chlorine residuals (14). Chlorine dioxide
residuals are also oxidizing agents, though. As a result, any attempt
to measure total residual chlorine results in a measurement of both
total residual chlorine and chlorine dioxide residuals. No officially
accepted method of eliminating the chlorine dioxide residual
interference is available (14).
In the absence of data on total residual chlorine in cooling water
treated with chlorine dioxide, it was assumed that the concentration
of total residual chlorine is zero. The basis for this assumption is
fairly sound. The quantity of chlorine dioxide added to the cooling
water is much greater than the quantity of chlorine added, and
chlorine is a more powerful oxidant than chlorine dioxide (22).
Therefore, the limited amount of chlorine is probably consumed by
inorganic reducing agents and the biological fouling organisms before
chlorine residuals are formed. Although total residual chlorine is
probably not present, chlorine dioxide residuals, which are also
toxic, are present.
Chlorine dioxide is currently being used for biofouling control in a
limited number of steam electric powerplants with once- through
cooling water systems and in a single plant with a recirculating
cooling water system (23).
Bromine Chloride
Facility Description. A bromine chloride biofouling control facility
is identical to a chlorine biofouling control facility except for
minor changes required by differences in the physical and chemical
properties of bromine chloride and chlorine. Bromine chloride is
denser than chlorine, so. the handling equipment and scales for the
containers are of higher capacity. Bromine chloride exists in
equilibrium with bromine and chlorine in both the liquid and the
gaseous phases in . containers. The vapor pressure of chlorine is
higher than the vapor pressures of bromine and bromine chloride;
therefore, a chlorine-rich vapor exists in the gas phase in
containers. As a result, bromine chloride is always withdrawn from
containers as a liquid, and an evaporator is used to convert the
liquid to gas. Bromine chloride condenses at a higher temperature
2S9
-------
than chlorine, so the evaporator is designed to operate at a higher
temperature in a bromine chloride facility than in a chlorine facility
to prevent condensation of bromine chloride. The design changes
consist of using steam or direct electric.resistence heating rather
than hot water. Bromine chloride attacks both steel and polyviriyl
chloride, the materials used in chlorination facilities. As a result,
nickel or Monel is substituted for steel and Kynar is substituted for
polyvinyl chloride in all parts which are in contact with liquid or
vapor bromine chloride (23, 24).
Effectiveness. The substitution of bromine chloride for chlorine in
biofouling control should eliminate all total residual chlorine in the
cooling water. Although total residual chlorine will not be present,
bromine residuals, which are also toxic, will probably be present.
Bromine chloride has been used on a trial basis at three plants with
once-through cooling water systems (25, 26, 27), but is not currently
being used for biofouling control at any steam electric powerplants
(24).
Ozone
Facility Description. An ozone biofouling control facility consists
of"threesystems: the ozone generating system, the gas treating
system/ and the gas-liquid contacting system.
Ozone is generated on site by passing an oxygen-bearing gas through a
high frequency electric field called a corona. A schematic diagram of
a corona cell is shown in figure VI1-9. The cell consists of two
electrodes separated by a narrow gap. One electrode is grounded. A
high voltage alternating current is applied to the other electrode.
This electrode discharges to the grounded electrode creating a high
intensity corona discharge in the gap between the electrodes. The
dielectric on the discharging electrode stabilizes the discharge over
the entire electrode so that it does not localize in an intense arc.
The corona discharge in the gap converts some of the oxygen in the
oxygen- bearing gas passing through the gap to ozone. A relatively
small amount of the energy in the. discharge is utilized to convert
oxygen to ozone; consequently, a substantial amount of heat is
produced. The low volume of gas passing through the gap cannot
dissipate the heat, so the electrodes are cooled by either a liquid or
a gas in contact ,with the side .of the electrode opposite the discharge
gap. The configuration of the corona cell, the materials of
construction, and the cooling method vary with manufacturer (28, 29).
Ozone can be generated from either air or oxygen. In cooling water
biofouling control applications, the choice between air and oxygen is
based primarily on facility design capacity. For small capacity
facilities, air is more economical. For large capacity facilities,
oxygen is more economical. The breakpoint between air and oxygen is
shown in figure VII-10 as a function of facility capacity expressed as
flow and dosage.
290
-------
High Voltage
Alternating
Current
ELECTRODE
DIELECTRIC
(grounded)
Figure VII-9
SCHEMATIC DIAGRAM OF CORONA CELL (28)
291
-------
80
1
0)
co
o
fi
•o
a)
•H
H
Economics
Favor
Oxygen
10
Economics
Favor
Air
I I
100
Plow Treated (MGD)
Figure VII-10
EFFECT OF 020NATION FACILITY CAPACITY ON
PROCESS CHOICE - OXYGEH VS. AIR (28)
-------
Whether air or oxygen is used, the gas entering the generator must be
dry. Moisture is removed from air by lowering its temperature, which
causes the water to condense and then passing the air through a
desiccant drier. Makeup oxygen comes directly from the oxygen source.
Recycled oxygen is extracted from the waste gas from the gas-liquid
contacting system. Moisture is removed from the recycled oxygen in
the same way it is removed from air.
The three basic methods of supplying makeup oxygen for ozone
generation are on site liquid oxygen storage, on site generation by
the pressure-swing adsorption process, and on site generation by the
cryogenic , air separation process. On site liquid oxygen storage
requires an insulated tank, an evaporator, and the appropriate piping
and valves. The stored liquid is withdrawn and vaporized to gas on
demand. The supply of liquid oxygen is replenished periodically by
tank truck deliveries from local suppliers. On site storage is the
preferred method when makeup requirements are less than 1 ton per day.
On site generation by the pressure-swing adsorption process is
generally used for oxygen requirements from 1 to 30 tons per day. In
this process, air is compressed, cooled to condense moisture, and then
passed through an adsorbent that removes carbon dioxide, water vapor,
and nitrogen to produce a 90 to 95 percent oxygen gas stream. On site
generation by the cryogenic air separation process is generally used
for oxygen requirements in excess of 30 tons per day, so this, process
is rarely used in ozonation systems (28).
The gas-liquid contacting system consists of a closed tank, diffusers,
and an ozone decomposition device. Ozone is dispersed in water
through diffusers which release the ozone as fine bubbles. The
bubbles are dispersed in the water in a closed tank so that the ozone
in the gases released from the water can be collected and passed
through the ozone decomposition device before release of the gases to
the atmosphere or recycle of the gases to the ozone generator. Ozone
is fairly insoluble in water; therefore, contacting system designs
must optimize the tradeoff between contact time and ozone utilization.
A typical ozonation facility using air to generate ozone is shown in
figure VII-11. A typical ozonation facility using oxygen to generate
ozone is shown in figure VI1-12. The gas treating system, the ozone
generating system, and the gas-liquid contacting system are delineated
on the diagrams.
Effectiveness. The substitution of ozone for chlorine in biofouling
control should eliminate all total residual chlorine in the cooling
water. Although total residual chlorine will not be present, other
oxidant residuals, which are also toxic, will probably be present.
Ozone is not currently being used for biofouling control at any steam
electric powerplant. Ozone has been used on a trial basis for
biofouling control at one plant (23).
Z93
-------
N>
CHILLED '
WATER |
AIR /" "SI.,, 1 ... .r ^.| \\^ | >
COMPRESSOR!
1 *
1 HjO
1
1
1
1
Gas Treating Syst
1
WATER
,,. fc. O2OMATOR
••" ""•! 1 r~
|| CONTACTOR
V ^
J 1 TREAT
CLEAN
DISCHA
I
Jr
FED
AIR
RQE
DEC
DRYER 1 WATER
1
i
:em Ozone ' Gas -Liquid
Generating 1 Contacting
1 System | System
OZONE
DMPOSIT
DEVICE
Figure VII-11
OZONATION FACILITY USING AIR TO GENERATE OZONE (28)
-------
to
Ul
t PURGE ' ..— — ,. .,«
. OXYGEN RECYCLE LINE ^ | OZONE DECOMPOSITION
* ' DEVICE
i 1 ,. _„. „„,
I '
I OXYGEN i WATER
1 GENERATOR • vSi.lc5 .
' • ^f i ' • ' 1
I ~~ -|— "" ' ''**'. UtUINAIUH " *""" "
x^~*5ri 1 . f \^\ ifc, 1 - ' 1 j
/ | **1 y\ J *" xK xk I i
^-^ ! CWL^D V ' CONTACTOR
COMPRESSOR I WATER J I
i t V V I
1 H20 A.l .
. I TR
i DRYER | v\
i 1 .
I Gas Treating System ' Ozone Generating . Gas
, | System « Cc
! ! £
j
t
k
1
EATED
(ATER
i -Liquid
mtacting
>ystem
Figure VII-12
OZONATION FACILITY USING OXYGEN TO GENERATE OZONE (28)
-------
Tot.a.l Residual Chlorine Control Through Mechanical Cleaning
Mechanical means of cooling system cleaning can be used in place of
chemical antifoulants. The most obvious method is manual cleaning
which requires long plant downtime. Two types of automatic mechanical
condenser cleaning systems, which can be used during normal plant
operations, are the Amertap and American M.A.N. systems. Diagrams
showing the major components of each of these systems are presented in
figures VI1-13 and VI1-14. The Amertap system is the most common type
of automatic mechanical cleaning system. By circulating oversize
sponge rubber balls through the condenser tubes with the cooling
water, the inside of the condenser tubes are wiped. The balls are
collected in the discharge water box by screens and repumped to the
inlet of the condenser for another pass through the system. They can
be used on an intermittent or continuous basis. The American M.A.N.
system uses flow drive brushes which are passed through the condenser
tubes intermittently by reversing the flow of condenser cooling water.
The brushes abrasively remove fouling and corrosion products. Between
cleaning cycles, the brushes are held in baskets attached at both ends
of each tube in the condenser.
The Amertap and, to a lesser extent, the American M.A.N. system have
been reasonably successful in maintaining condenser efficiency and
reliability. Some problems are abrasion and grooving of condenser
tubes, and, in some cades, the systems themselves become fouled and
must be cleaned.
Priority Pollutants Control Through Alternative Corr.osion" and-• Scaling
Control Chemicals
The principal control technology available to eliminate the discharge
of priority pollutants as a result of the use of corrosion and scale
control agents is the substitution of corrosion and scaling control
agents which do not contain priority pollutants. Most powerplants
usually purchase the chemicals they need for corrosion and scaling
control from vendors as prepackaged mixtures. The exact composition
of these "proprietary" mixtures is confidential but a partial listing
of some of the commonly used mixtures • which do contain priority
pollutants is given in table VII-10 (31). At least one vendor is now
offering a corrosion and scaling control mixture that contains neither
zinc nor chromium and has proven very effective in several full scale
test programs in various industrial applications (32).
Priority pollutant Control Through Alternative Non-Oxidizing Biocj:des
Many steam electric powerplants use non-oxidizing biocides instead of
or in conjunction with the oxidizing biocides. The non-oxidizing
biocides are also effective in controlling biofouling but do so
through mechanisms other than direct oxidation of cell walls.
A list of most of the commonly used oxidizing biocides is presented in
table VII-11 (33, 34). Note that there are really two kinds of
oxidizing biocides. The first group are appropriate for use in large
296
-------
Ni
\O
OUTLET MATER
MX
COOLING
WATER
OUTLET
STRAINER
SECTION
TURBINE EXHAUST
STEAM
CONDENSE!
DGXE
,INLET HATEI
MX
4 *
».",!,",'.=
'•^
1
x*
P
„•"•"»•,
,1 1
3 ' f
r~' JL \r
dh II
RECIRCULATION
PUMP
a
^ «
44
1
ATCH FOR INSERTIN6
R REMOVINQ BALLS
U~ BALL COLLECTING
BASKET
^ BASKET SHUTOFF
• FLAP xp>4 ;:;:', ',;;
|>c^ »p>» ^
\>>T>^f '" '
BALL
ELECTOR
4
1
L— j
V
r>
SPONGE,RU88ER t
SALLS (TYPICAL)
COOLIMB WATER
INLET
FIGURE VII -13
SCHEMATIC ARRANGEMENT OF AMERTAP CLEANING SYSTEM (30)
-------
NORMAL ROW PI PING
BACKWASH FLOW PI PING
OPEN 0
CLOSED C
Ni
<^>
00
L i
i
/c
/c
/o
Xo
SECTION OF
CONDENSER BEING
BACKWASHED
FROM INTAKE »-
FROM INTAKE *-
TO OUTFALL -
TO OUTFALL ~
0
HxH
F
c
H'H
Xo Xc
Xo XC
Xc Xo
T^
Xo xc
FIGURE VII -14
SCHEMATIC OF M.A.N. SYSTEM REVERSE FLOW PIPING (30)
-------
Table VII-10
CORROSION AND SCALING CONTROL MIXTURES
TO CONTAIN PRIORITY POLLUTANTS (31, 32)
Compounds Known to Contain
Priority Pollutants
NALCO CHEMICALS
25L
38
375
Specific Priority Pollutants
Contained in Product
Copper
Chromium
Chromium
CALGON CHEMICALS
CL-70
CL-68
BETZ CHEMICALS
BETZ 4QP
BETZ 403
Dianodic 191
Zinc Chloride
Sodium Dichromate, Zinc Chloride
Chrornate and Zinc Salts
Chrornate and Zinc Salts
Chromate and Zinc Salts
HERCULES CHEMICALS
CR 403
BURRIS CHEMICALS
Sodium Dichromate
Zinc Bichromate, Chromic Acid
Sodium Dichromate
299
-------
Table VII-11
COMMONLY USED OXIDIZING BIOCIDES (33, 34)
Group A - Appropriate for Use in Large Scale Applications,
RequireExpensive Feed Equipment
Bromine chloride
Chlorine
Chlorine dioxide
Ozone
Group B - Appropriate for Use on Intermittent Basis or in Small
Systems_, May Not Require Expensive Feed Equipment:
Ammonium persulfate
Bromine
Calcium chlorite
Calcium hypochlorite
Dibromonitrilopropionamide
2,2-dichlorodimethyl hydantoin
Iodine {
Potassium hydrogen persulfate
Potassium permangnate
Sodium chlorite
Sodium dichloroisocyanurate
Sodium dichloro-s-triazinetrione
Sodium hypochlorite
Trichloroisocyanuric acid
NOTE: None of these compounds are priority pollutants.
300
-------
Scale applications and require expensive feed equipment. These
compounds have all been thoroughly discussed earlier and no further
discussion will be presented here.
The second group of oxidizing biocides are commonly purchased from
suppliers as a liquid or solid in small containers (i.e., 50 gallon
drums, 100 pound bags). These biocides are fed using relatively
simple feed equipment (solution tank,.mixer, pump, diffuser) and in
some cases are simply dumped into the influent lines to the cooling,
system. Note that many of these compounds contain chlorine which is
released upon solution in water to form hypochlorous acid (free
available chlorine). The use of chlorine in this form will create the
same problems as injection of chlorine gas, the only difference being
the method in which the chlorine was introduced to the system. Plants
using the "chlorine bearing" compounds will have to meet the same
effluent standards as plants injecting chlorine gas. Both chlorine
minimization and dechlorination are technologies available to help a
plant meet total residual chlorine limitations.
A third possible technology is the substitution of a "nonchlorine
bearing" oxidizing biocide which may offer similar biofouling control
but will not result in the discharge of residual chlorine. For
example, a plant currently using calcium hypochlorite could switch to
dibromonitrilopropionamide (DBNPA) and avoid the discharge of residual
chlorine altogether.
Another substitution available to the plant is to use a nonoxidizing
biocide instead of an oxidizing biocide. A list of the commonly used
non-oxidizing biocides is presented in table VII-12. as the table
shows, a large diversity of products have been used for this purpose.
An advantage that non-oxidizing biocides have over their oxidizing
counterpart is their slow decay. Oxidizing biocides are, by design,
very reactive compounds. As a result, the oxidizing biocides react
with many contaminants present in the cooling water and rapidly decay
to relatively non-toxic compounds. The non-oxidizing biocides are, by
design, very toxic materials which react selectively with
microorganisms and other life forms. They may decay very slowly once
released to the environment and thus pose a substantial environmental
hazard.
Many of the non-oxidizing biocides are priority pollutants. If a
compound is a known priority pollutant it is marked with an asterisk
to the left of the compound name.' Since there are many non-priority
pollutant, non-oxidizing compounds readily available on the
marketplace, it is not recommended that priority pollutants be used
for this purpose.
Before searching for a substitute for the current biocide a plant is
using, careful examination should be given for the need of biocides at
all, especially non-oxidizing biocides. Once-through cooling systems
located in areas where biofouling is a problem should be able to
achieve adequate biofouling control with chlorine or perhaps one of
the other "large-scale" oxidizing biocides. If additional control
301
-------
Table VII-12
COMMONLY USED NON-OXIDIZING BIOCIDES (33, 34)
*Acid copper chrornate
*Acrolein
n-alkylbenzyl-N-N-N-trimethyl ammonium chloride
n-Alkyl (60% C14 , 307, C16, 5% C12 • 57° C18 ) dimethyl bensyl
Ammonium chloride
n-Alkyl (50% C12 , 30% C14 , 17% C16 , 3% C18) dimethyl ethylbenzyl
ammonium chloride
n-Alkyl (98% C12» ^^ C14^ dimethyl-1-naphthylmethyl ammonium
chloride
alkylmethylbenzylaramonium lactate
Alkyl-9-methyl-benzyl ammonium chloride
n-Alkyl (C6 - C^g) - 1,3-Propanediamine
*Arsenous Acid
^Benzenes
Benzyltriethylammonium chloride
Benzyltrimethylammonium chloride
Bis-(tributyltin) oxide
Bis-(trichloromethyl) sulfone
Bromonitrostyrene
Bromos tyrene
2-bromo-4-phenylphenol
*Carbon tetrachloride
Cetyldimethylammonium chloride
Chloro-2-phenylphenol
2-chloro-4-penylphenol
*Chromate
*Copper Sulfate
*Cromated copper arsenate
*Cresote :
*Cyanides
3,4-dichlorobenzylammonium chloride
302
-------
Table VII-12 (Continued)
COMMONLY USED NON-OXIDIZING BIOCIDES (33, 34)
*2,4-dichlorophenol
Dilauryldimethylainmonium chloride
Dilauryldimethylammonium oleate
Dimethyltetrahydrothiadiazinethione
Disodium ethylene-bis-(dithiocarbainate)
Dodecyltrimethylammonium chloride
Dodecyl .dimethyl ammonium chloride
Dodecyl guanidine acetate and hydrochloride
Isopropanol
*Lactoxymercuriphenyl ammonium Lactate
Lauryldimethyl-benzyldiethylammonium chloride (7573)
Methylene bisthiocyanate
Octadecyltrimethylammonium chloride
*PhanyImercurie triethanol-ammonium lactate
*Phenylmercuric trihydroxethyl ammonium lactate
o-phenylphenol ,
Poly-(oxyethylene (dimethylimino) ethylene-(dimethylimino)
ethylene dichloride) ,
Sodium dimethyldithiocarbamate
*Sodium pemtachlorophenate , .
*Sodium trichlorophenate
2-tertbutyl-4-chloro 5-methyl phenol
2,3,4,6-tetrachlorophenol
Trimethylammonixim chloride
*Zinc salts
In addition to the above chemicals the following may be present
as solvents or carrier components:
Dimethyl Formatnide
Methanol
303
-------
Table VII-12 (Continued)
COMMONLY USED NON-OXIDIZING BIOCIDES (33, 34)
Ethylene glycol monomethyl ether
Ethylene glycol monobutyl ether
Methyl Ethyl Ketone
Glycols to Hexylene Glycol
*Heavy aromatic naphtha
Cocoa diamine
Sodium chloride
Sodium sulfate
Polyoxyethylene glycol
Talc
Sodium Aluminate I
Mono chlorotoluene
Alkylene oxide - alcohol glycol ethers
NOTE: *Indicates the compound is known to contain a priority
pollutant. Some of the other compounds may degrade
into priority pollutants but no data was available
to make a definite determination.
304
-------
seems needed, the plant should first attempt modifications of its
current biocide program, i.e., change the dosage, frequency, etc.
Another possibility is the periodic use of a dispersant or "chlorine
helper" which is a specially formulated mixture designed to increase
the penetration of chlorine, especially into existing thick slime-
films. A study was conducted at Plant 5004 over a three year period
during which the dosage rate of chlorine and a "chlorine helper" were
varied. The "chlorine helper" was found to significantly increase the
cleanliness factor of the condenser tubes and helped to keep mud" and
silt from settling out in the cooling systems (35). The success of
the use of a "chlorine helper" is likely to be extremely site specific
and depend on water quality, system design and other factors.
Recirculating plants also often operate with the use of chlorine
alone. In those recirculating plants using cooling towers with wood
fill, a special biofouling problem exists. It is only in these
systems in which the use of non-oxidizing biocides is really justified
(23). The problem is that the wood fill is susceptible to fungal
attack in the center of the boards. Chlorine doses high enough to
provide microbial control at the center of the boards would result in
the delignification of the lumber and destroy the wood's structural
strength. Thus, a , nonoxidizing biocide offers a perfect solution.
For this reason, lumber used in cooling tower fill is often pre-
treated with a non-oxidizing biocide. Pentachlorophenate and various
trichlorophenates are frequently used for this .purpose (33). Both
pentachlorophenate and the trichlorophenates are priority pollutants.
Vendors of non-oxidizing biocides have indicated that nonpriority
pollutant non-oxidizing biocides are available at approximately the
same cost as their priority pollutant analogs (33). Thus, when the
use of a non-oxidizing biocide is required, there is no cost penalty
in using a compound that is not a priority pollutant. The use of non-
oxidizing biocides in once-through cooling systems is likely to be
prohibitively expensive and represents a serious environmental hazard
and is therefore, not recommended.
Priority Pollutant Control Through Replacement of Asbestos
Cooling Tower Fill .
The technology evaluated to control the discharge of asbestos fibers
in cooling tower blowdown is replacement of existing asbestos fill
material. Existing asbestos cement fill is taken out of the tower and
replaced with wood, PVC, or ceramic tiles. This is a straightforward
disassembly and reassembly construction procedure. The tower is, of
course, out of service during .this construction activity.
Ash Handling
Systems for handling the products of coal combustion by hydraulic or
pneumatic conveyors have been used for 50 years or more. With the
advent of larger steam generation units, larger ash handling systems
have been built with heavier components to cope with the increased
305
-------
loads. Powerplant refuse, which can be classified as ash, falls into
four categories (36):
1. Bottom ash (dry or slag)—material which drops out of the
main furnace and is too heavy to be entrained with the
flue gases;
2. Fly ash—finer particles than bottom ash which are
entrained in the flue gas stream and are removed
downstream via dust collecting devices such as
electrostatic precipitators, baghouses, and cyclones;
3. Economizer and air preheater ash—coarser particles which
drop out of flue gases as a result of changes in direction
of the flue gas; and,
4. Mill rejects, or pyrites—variety of coarse, heavy pieces
of stone, slate, and iron pyrite which are removed from
coal during preparation stages (at plants which clean the
coal prior to use).
Economizer and air preheater ashes are usually collected in hoppers
and transported in conjunction with fly ash to a disposal site; thus,
fly ash transport systems are considered to apply to the economizer
and preheater ash as well. Mill rejects are wastes encountered in
coal preparation which is usually performed off site; therefore, mill
reject transport systems are treated as off site operations and are
not addressed in this discussion. As a result, only bottom ash and
fly ash handling systems are considered in this subsection.
Statistics for 1975 indicate that approximately 410 million tons of
coal were burned, producing nearly 41 million tons of fly ash and 22
million tons of bottom ash and boiler slag (37). As coal use
increases to replace the dwindling supplies of other fuels used for
generating electric power, the amounts of fly ash and bottom ash
requiring proper disposal will also increase. Perhaps the most
environmentally acceptable and economically attractive method of
disposal is through utilization as a raw material in the manufacture
of new products. Recently fly ash and other coal residues have found
uses such as lightweight aggregates for construction, structural
fills, embankments, or low-cost highway base mixes. 'Ash also has been
successfully used as a soil amendment, in fire-control or fire-
abatement procedures, and for treatment of acid mine drainage. Since
ash is typically high in concentrations of many metals such as copper,
vanadium, aluminum, chromium, manganese, lead, zinc, nickel, titanium,
magnesium, strontium, barium, lithium, and calcium, it may serve as an
important source of these metals in the near future (38). Thus far,
however, the use of fly ash and bottom ash in manufacturing has been
relatively small, only 16.3 percent in 1974 (38); therefore, the major
portion of the fly ash and bottom ash resulting from coal combustion
must be disposed of.
306
-------
Fly Ash
The treatment and control technologies applicable to fly ash handling
systems are:
1. dry fly ash handling;
2, partial recirculation fly ash handling; and
3. physical/chemical treatment of ash pond overflows from
wet, once-through systems.
Dry Systems
Dry fly ash handling systems are pneumatic systems of the vacuumor
pressure type. Vacuum systems use a vacuum, produced by ejectors or
mechanical blowers, to provide the necessary air flow to convey ash
from the electrostatic precipitator (ESP) hoppers to its destination
point, i.e., a dry storage silo or landfill. Pressure systems, on the
other hand, make use of pressure blowers to provide the required air
flow for ash conveying. In general, a vacuum system is more limited
in conveying distance than a pressure system; thus, vacuum systems are
generally not used for systems covering distances greater than 500 to
700 feet (39). Controls for a vacuum system are generally simpler
than those for a pressure system. This can be advantageous for
systems which have a large number of ash hoppers, e.g., 35 to 40.
Because dry fly ash systems eliminate the need for an ash sluice water
discharge, they represent a means of achieving zero discharge.
Vacuum Systems. In this type of system, fly ash is pneumatically
conveyed to a dry storage silo by means of a mechanical vacuum
producer. An example of a vacuum system for dry fly ash is shown in
Figure VII-15. Fly ash is drawn from the bottom of the ash hopper
through the dust valves and segregating valves to the primary and
secondary collectors above the dry storage silo. The dust-free air
from the collectors is sent through a cartridge filter before it is
allowed to pass through the mechanical blowers where it is vented to
the atmosphere.
Vacuum systems are limited in conveying distance. The distance to
which material can be conveyed depends on the configuration of the
system and plant altitude above sea level. The application of vacuum
systems is generally limited from 500 to 700 feet of distance from the
ash hoppers to the dry storage silos (39). The simplicity of vacuum
systems makes them particularly advantageous in systems with 35 to 40
ESP hoppers.
Equipment. The following list of equipment comprises the major
components of a vacuum system:
1. vacuum producers—mechanical or hydraulic;
2. valves—type "E" Dust Valves and segregating valves;
307
-------
Cartridge, Filter
Burnt Valves
Type "E" Outlet
Segregating
Valvea A
Primary
Collector
Secondary »
Collector
.(Bag Filter)
Vent
Storage Silo
Aeration
Silo Unloader-
Vacuum
Blower
Figure VII-15
DRY FLY ASH HANDLING - VACUUM SYSTEM
308
-------
3. conveying pipe;
4. dry storage—silo, dust collectors, and vent filters;
5. dust conditioners (or unloaders); and
6. controls.
Many vacuum systems use mechanical exhausters to provide the necessary
vacuum to convey fly ash to the dust collectors. These mechanical
exhausters are 300- to 400-hp blowers (39), which are similar to those
used in pressure systems. Vacuum production may also be provided by
mechanical vacuum pumps motor driven machines of either the dry or
water-injected positive displacement type or the water sealed rotary
bucket type. Experience has shown that water-injected lobe type
positive displacement vacuum producers cannot be used in cases where
flue gases are high in sulfur dioxide (40). In such cases, dry vacuum
pumps or watersealed machines must be used to avoid corrosion. The
use of any mechanical vacuum pump requires the installation of
collecting equipment of the highest possible efficiency ahead of the
pump.
Figure VII-16 presents a diagram of a hydraulic vacuum producer. This
particular unit, marketed under the trade name "Hydrovactor," is
manufactured by the Allen-Sherman-Hoff Company. The hydrovactor makes
use of high-pressure water (from 100 to 300 psi) discharged through an
annular ring of nozzles into a venturi throat to create the vacuum to
convey dust to the collectors (40). A similar unit, known as a
"Hydroveyor," is manufactured by United Conveyor Corporation. The
amount of water required, the pressure of the water, and the extent of
the vacuum produced are a function of the ash generating rate and
distance to the storage silo. Typical values might be 1,500 gpm of
water through the venturi to draw 100 pounds per minute of air at 13
inches of mercury (39).
Figure VII-17 illustrates the type "E" dust valve which is installed
under the fly ash collection hoppers. This valve is air-electric
operated and is designed to admit ambient air . through integrally
mounted inlet check valves. As the slide gate is opened, air drawn
through these valves and from the interstices in the dust becomes the
conveying medium which transports the fly ash. Valve opening and
closing is controlled by fluctuations in the vacuum at the producer.
A drop in vacuum indicates an empty hopper, so that an operator, or an
automatic control device, is alerted to move to the next point of dust
collection.
When the fly ash is conveyed from two or more branch lines,
segregating values are used to block off any branched lines which are
not in use. By isolating the lines in this manner, the full energy of
the conveying air can be applied to one branch at a time without the
possibility of loss of conveying capacity due to leaks in other
branches. Segregating valves may be provided with chain wheel or hand
309
-------
I/*"PIPf MI'S
(VACUUM ft PMES5.0AUSE CSNH*S)
•IMLET LINER
taecTon HEAO wtrw
IZSIfe. OM Z3OI&, WttTCM
PKC3S.INt.ET FLANGE
CCESS PLUGS
(BOTH sioesj
NOZZLE Tll»
THROAT CASINO
TMM01T USERS
Figure VII-16
DIAGRAM OF A HYDRAULIC VACUUM PRODUCER
Reprinted from A Primer for Ash Handling by Allen-Sheman-Hoff
Company by permission of Allen-Sherman-Hoff Company, A Division
of Ecolaire. Year of first publication: 1976.
310
-------
SYUNO6R
**•
S.S. SLIDE SATE
VALVE SEAT
INLET CHECK VALVC
OUTI.IT
VALVE 800Y
S.S.SU8C 3ATC
8*X**TYP6*E*MATERIAl.S HANOUN6 VACVC
( CTUNOSH OPgBATEO )
. Figure VII-17
TYPE' "E" DUST VALVES
Reprinted from APrimer for Ash Handling by Allen-Shennan-Hoff
Company by permissionof Allen-Sherman-Hoff Company, A Division
of Ecolaire. Year of first publication: 1976.
311
-------
wheel operators as well as air-electric operators as shown in figure
VII-18.
There are three types of pipe generally used in ash handling:
1. carbon steel pipe,
2. centrifugally cast iron pipe, and
3. basalt-lined pipe.
In general, the carbon steel and centrifugally cast iron pipes are
most commonly used for dry handling (39). Basic pipe for ash handling
service have a Brinnell Hardness Number (BHN) of 280; fittings are
harder (approximately 400 BHN) to combat the added abrasive action at
bends in a conveying line (40). Typical pipe and fittings are shown
in figure VII-19. Integral wear back, tangent end fittings are used.
A line of fittings with replaceable wear backs is available for vacuum
systems. These wear backs are reversible so that each provides two
points of impact where abrasion is most severe. In addition, each
wear back, for a given size pipe fitting, can be.used on all fittings
of that size. Some typical line sizes which may be used for varying
system capacities are provided in table VII-13. Experience has shown
that one line should handle no more than 50 TPH fly ash and that two
lines with cross-over provision should be run to the silo (40).
Dust caught by the collectors is continuously dropped into fly ash
storage silo where it is held until disposed. Storage silos may be of
carbon steel or hollow concrete stave construction. Flat bottom silos
are equipped with aeration stones or slides to fluidize dust and
induce flow to the discharge outlets. Motor driven blowers supply the
fluidizing air. Silos are also provided with bag vent filters to
prevent the discharge of .dust along with displaced air as the silo is
being filled. Alternately, venting can be provided by a duct from the
silo roof back to the precipitator inlet. It may be necessary to
supply lowpressure blowers on the vent duct to pvercome losses which
may prevent release of the conveying air, resulting in a pressure
build up in the silo and drop-out of the fly ash in the duct.
Fly ash is normally deposited in trucks or railroad cars for transport
to a dump area. In such cases, it is necessary to wet the dust to
prevent it from blowing off conveyances during transportation. This
is accomplished by means of conditioners which may be of the
horizontal rotary pug-mill type or the vertical type.
The horizontal type is suitable for conditioning a maximum of 180 tons
of dust per hour with water additions as high as 20 percent by weight
(40). This unit requires a rotary feeding device between the
discharge point and the unloader inlet to feed dry ash at a steady
measured rate. Dust is fed by means of the star (rotary) feeder to
the inlet of a screw feeder which carries the dust to the end of a
rotating drum. Water is added at the discharge point of the screw
feeder and at various points along the drum as the dust is tumbled and
312
-------
I
TV
_ .V*L«e tQSf,
IrLMIM 6NO OR
_ .ACCESS COV6R
ROUL fin "* PISTOI*' *OO
JU8IMS
LIMIT
iuoe SATS
(TMO CAP
AC7UAT1HC PIN
SECTION, "a-a"%
1/2* N.P.T. CONDUIT CONM,
SECTION ""A-A"
Lgven
LIMIT
LIMIT SWITCH OPERaTING
SLIDE SATE
T. COWOUIT CONH. «
•A'
AIR CONTNOL VALVE
sea RESATI no su o s ir ...ryA uyET
CA»R-€L£CTRIG OPeRATSOl
Figure ¥11-18
SEGREGATING VALVES '
'Reprinted from A_Primer for Ash Hand!ing by Allen-Sherman-Hoff .
Company, by permission of, Allen-Sharman-Hoff Company, A Division
of Ecolaire. Year of first publication: 1976.
313
-------
STANDARD COUPLINGS, ADAPTORS * BLIND FtANGIS
Hi
fouowcni
CCTJPUNS
BUND RANGE
Views ! S
5S
fut.if.fcn v
fs! M*K. /on iar > i*"
THilli"
ASKCeUTI
n& iou*
ADAPTORS 4" ttru 9*
litnoLE- n«-r—
HIH9 ' '
SINGLE COUPLING & filler
^UfflBCT;
-f
-------
Table VII-13
ASH CONVEYING CAPACITIES OF VARIOUS SIZE PIPES (39)
Pipe Size Ash Generating Rate
(inside diameter in inches) (tons/hour)
6 15-20
8 25-50
10 50-75
315
-------
rolled past a series of scrapers toward the discharge point. Operator
attention is essential to the satisfactory functioning of this
conditioner.
The vertical conditioner is more adaptable to automatic operation with
20 percent water addition (40). This unit is supplied with a
fluidizing feeder and metering cut off gate to provide uniform feed.
Dust enters a chamber on the top of the vertical conditioner where it
falls onto a rotating distributing cone. This creates a cylindrical
curtain of dust which is sprayed from numerous directions by high-
velocity fog-jet nozzles. The wetted dust, which is driven onto the
walls of the bottom chamber, is moved toward the bottom discharge
nozzle by means of a pair of motor-driven scraper blades.
Both units require water at a minimum pressure of 80 psi to achieve
intimate mixing. Water supplied at a lower pressure cannot penetrate
the mass of dust passing through in a very short period of time (40).
Controls for vacuum fly ash systems are activated by changes in
vacuum. When a hopper is emptied of fly ash, the system vacuum will
drop, A pressure switch then activates a rotary step switch to close
the dust valve under the hopper and to open the valve under the next
hopper. This procedure continues until all the hoppers are empty.
Maintenance. There are several high-maintenance areas associated with
vacuum systems:
1. Vacuum Blowers - Problems may arise if the conveying air
is insufficiently filtered upstream of the blower. Dust
in the conveying air would then pass through the blower,
and erode the blades.
2. Bag Filter - Bag filter breakage is a common maintenance
problem, creating a fugitive dust problem usually just
within the confines of the silo area.
3. Leakage - Leaks in the couplings of the pipe system can
reduces the conveying power of the system. Maintenance
problems for leakage are much less severe for vacuum
systems as compared to pressure system leakage because
all leaks are inward.
4. Vacuum Silo - Since the silo is generally outside the
plant area, maintenance may be less frequent. For the
vacuum silo, this can be more of a problem because it is
more complex than a pressure silo due to the need for
collectors.
Pressure Systems. This system conveys fly ash from individually
controlled air locks (at the bottom of the ESP hoppers) to a dry
storage silo by means of pressure provided by positive displacement
blowers. A schematic diagram of a pressure system appears in figure
VI1-20. The mechanical blowers supply compressed air at pressures of
316
-------
To
Fly Ash Hoppars with
Air £oek Valves
•fed-
Blower
HXJ-
V V V V
Prosaure Blower
Segregating
Valves
Oust
Conditioner"
(Unloader)
fl Vent
[ {"Filter
Storage Silo
Aeration
Figtire VII-20
DRY FLY ASH HANDLING SYSTEM - PRESSURE SYSTEM
317
-------
up to 32 psi (40). The main difference between the vacuum and
pressure systems is that the pressure system does not require cyclone
collectors at the storage silo; instead, a vent filter relieves the
silo of the air displaced by the incoming dust as well as the expanded
volume of the conveying air. In some systems, a return line is run
from the vent filter back to the ESP hopper to avoid possible fugitive
dust emissions from the vent filter. A blower is usually required on
this line to overcome draft losses.
Equipment. The major components of a pressure system are essentially
the same as those of a vacuum system with the following exceptions.
Air locks are used to transfer fly ash from a hopper at one pressure
to a conveying line at a higher pressure (figure VII-21). These are
available in a wide range of capacities to meet any handling rate
required of a pressurized conveying system. Air- electric operated
cylinders control the positioning of upper and lower feed gates in
proper sequence with the equalizing valves between upper and lower
chambers. Manual cut off gates are supplied at the inlet and
discharge of each air lock to permit its removal without interrupting
operation of the rest of the system (40).
Silo storage is the same as for vacuum systems except that dust
collectors are not required; however, a self-cleaning vent bag filter
is required. Air-to-cloth ratio should be no greater than 2.5 cubic
feet per minute to 1 square foot of bag cloth area (40). Vent ducts
provide an alternate means of relieving air from silos.
Controls for pressure systems operate on a timed basis determined by
the amount of dust stored in each row of collector hoppers.
Individual air .locks on any given row are carefully interlocked with
the other air locks to prevent discharge of more than one hopper at a
time. Programmable controls are available to permit changing of air
lock cycling where dust loading fluctuations are expected.
Maintenance. There are several areas of high maintenance in a
pressure system. The blowers, in general, are high-maintenance items.
However, the risk of erosion of fan blades due to dust in the
conveying air is not as great in the pressure system as it is in the
vacuum system. Leakage, on the other hand, represents a more severe
problem in the pressure system than it does in the vacuum system.
Leaks in the pipe couplings can cause greater fugitive dust problems
because of the positive pressure in the lines. In this sense, the
pressure system is not as "clean" as the vacuum system.
Fugitive Dust Emissions. Dry fly ash handling systems potentially
have significant dust emission problems. These dust emissions can
occur at various locations within the ash handling system. Fly ash is
a very abrasive material so problems generally arise in maintenance.
Positive pressure fly ash transport systems generally incur problems
in the pipe joints. One of the major maintenance problem areas with
vacuum systems is with the bag filters used in the secondary or
tertiary collectors on top of the storage silo., If these bags break,
318
-------
'Figure ¥1-1-21
TYPICAL AIR LOCK VALVE FOR PRESSURE FLY ASH
- CONVEYING SYSTEM
Reprinted from APrimer for Ash Handling by Allen-Sherman-Hoff
Company by permTssion of A11en-Sherman-Hoff Company, a Division
of Ecolaire. Year of first publication: 1976.
319
-------
the dust-laden air stream will continue through the vacuum producer
and into the atmosphere. If the vacuum producer is hydraulic, then
the fly ash will be slurried with high-pressure water, eliminating the
dusting problem. Dusting problems also arise from bag breakage if a
mechanical exhauster is used. Another problem area is the unloader at
the bottom of the silo where spray nozzles are used to wet the fly ash
before it is dumped into the truck. These spray nozzles need
continuous maintenance to avoid pluggage and subsequent dusting
problems. Even with proper maintenance of the nozzles, the area
around the unloader is still exposed to excessive dusting. Some
facilities use roll-up doors to close off this area and vent the air
back to the precipitator.
EPA conducted a telephone survey to determine the types of regulations
on fugitive dust emissions which exist among different federal, state,
and local authorities. In general, there are no regulations which
apply specifically to dry fly ash handling systems. , Fugitive dust
emissions are usually covered by a more general regulation regarding
particulate emissions such as a general opacity reading at the plant
boundary. Regular monitoring or inspection for dust emissions is
generally not required. Enforcement is based primarily on complaints.
Retrofitting. The motivation for retrofitting dry fly ash handling
systems may stem from a variety of circumstances:
1. A shortage of water may exist for sluicing the fly ash to
ponds,
2. State or local regulations for certain aqueous discharges
may result in a retrofit, and
3. A marketable use for the fly ash such as an additive for
making cement.
Very little, if any, equipment could be reused in retrofitting to
a dry fly ash system from a wet handling system. The equipment
needing removal would be:
- Valves allowing flow from the ESP hopper into the sluice
line, if the sluice line runs into the hopper;
- Pumps for carrying fly ash to the pond; and
- The line used for conveying the ash slurry.
In some cases, fly ash is pneumatically conveyed via a hydrovactor (or
hydroveyor) to a mixing tank where it mixes with bottom ash for
sluicing to a pond. The piping and vacuum producers, in these cases
are potentially reusable. It would be necessary to shut down the
existing equipment during installation of the new equipment.
320
-------
Trip Reports. EPA visited several plants in order to define various
bottom ash and fly ash handling practices. This subsection discusses
dry fly ash handling systems encountered at some of these plants.
Plant 1811. This plant is a 615-MW coal-fired electric power
generating station located in Northern Indiana. The ash is generated
by two cyclone type boilers of 194 and 422 MW each. The coal is
characterized as low sulfur with an ash content of 10 to 12 percent
with 11 percent as the average. This bituminous coal comes from
Bureau of Mines Coal Districts 10 and 11.
The fly ash handling system currently in use at the plant is a dry
vacuum system that was retrofitted in early 1979. The previous system
was a wet sluicing operation that used a hydroveyor and ponding. The
major equipment for this dry system is presented schematically in
figure VI1-22. This is a dual system in terms of the separators,
i.e., cyclones and bagfilters, and the mechanical exhausters. There
are separate lines which run from Unit 8 ESP hoppers and Unit 7 ESP
hoppers. These lines feed separate cyclone collectors and bagfilters,
but one silo is used to store the ash transported by the two lines.
The storage silo has a diameter of 35 feet. Sixteen hoppers feed the
Unit 8 line (10-inch diameter pipe) and eight feed Unit 7 line. The
distance from the hoppers to the silo is approximately 300 feet. No
major problems occurred in the changeover from hydroveying the ash to
ponds to vacuum handling of the ash to a storage silo.
The fly ash system was fairly new at the time of the site visit, and
no major operating difficulties had been encountered. Early
experience showed that the optimum operating procedure was to run the
mechanical exhausters continuously; intermittent operation had caused
some difficulty in achieving a sufficient vacuum for fly ash
transport. Minor erosion of the exhausters had occurred.
In 1978, the plant generated 38,100 tons of fly ash. This ash is
currently trucked to a landfill site for disposal by an outside firm.
Closed cement trucks are used; the ash is not conditioned at the silo.
Plant 1164. This plant is a 447-MW coal-fired powerplant located in
Northwestern Colorado. The plant consists of two units: Unit 1
completed in 1965 and Unit 2 in 1976. Thie facility is a baseload
plant which uses cooling towers for condenser heat dissipation, dry
fly ash transport, and a zero discharge bottom ash sluicing system.
The plant burns a bituminous coal from Bureau of Mines Coal District
17. The plant is sufficiently close to the coal mine (9 miles) to be
considered a mine-mouth operation. Plant water is drawn from a nearby
river. The facility uses a vapor compression distillation unit to
recover recycleable water from cooling water blowdown. All
wastewaters are ultimately handled by an evaporation pond. A
generalized flow scheme for the plant appears in figure VI1-23. The
water system, as currently in operation, was designed by Stearns-
Rodgers.
321
-------
HEQUHICAL
EXHAUSTER
COMTUTOOOS
OPERAT1HG
SEPARATOR $
9 10
O O
°- Pnn
u- ^ y l,
O O O v
O Q 0 C
* S ^
i
5 e o y
BAG FILTER
MECHANICAL
EXHAUSTER.
t7
tACOBB
SWITCHES
FILTER 91
TOIT FILTER
COHXIOTOOS
OPERATING-
SEPARATOR 117
I 2
5678
Q _O f>.._Q_
_Q_Q_Q_Q_
1234
Figtire VII-22
FLY ASH SILO AND HOPPERS/PLANT 1811
322
-------
21
tVAPOHATKJN
i
j. ^ / \ "^ aoj^m "i
"7 T* ^^ r<
L / HAWWAl-i-mietWVOW
i zrjAcms
\ gra MWWATfH j
VJ. \ »««»»««•« \ n
;!UKN """
u
1 f 1 l- 1 fc M.OHMXJWNTO •_
| ~ 5VAK>K»nON PONO \
cUMunin eoouNa\
~*N^ _s*J TOWM \
^N^s^ s^**^ ' yiwt V
A», 1«« (VAT. 1(11
M»T 17 omnir
1 Mi A
1 HAKHP ' |
*u» / \iiMoo /«^"»«>
AM / \ OW< / f°WW
_14 •„„ „ ,», _,js — ;_«•«
1 MW
n WATIM
JL , MocwAwro HJJVWCWN 1°
m.TCT IH/-> '»• HK»QUAUT» HW-HH-W f
'N/ WMB X~ ^s
*1 . eoAioui
iupMtm
eUAWMU.
.T3
OftHN
typpw
IAHK
,31
1 13
s?
UWfl
BO4LOI
riLovnoowN i
LIAXAtMt
SAXPUNO
FWQM w
TnMTUINT
SIWAOI ,
WFU
10
W.TW . 2
lACKWAIM"
fWUVMMHo*** —— 1
IHIMOMi.
«.«m
-\ * / — "\
>» 1«
cUNKmaguNOW
,. t AIM WATIN
WMPMAU
^.v MWMIITHi*f»
WllTMUtWAnil ' TOMMMOttAXlTT
TANK ,0
UMCnUUMOlM
^*^4a,AH4t»aii»
in
r 01IHK ^ j »HtN.TO
\amiij IW.NMO
*ii !
ST-a-.«-«
gum ww'
11
oooyna
raww 4 »
mcreuTo
eoeuNOTOwm '«
iom WM
. t- f
~7aC«5S"A5it*"
. STORAOf
9H " OTOMI
M
1 1 n
CVA» n.y SOT WAS
M AIM ASM TOI
INT ID 2 K)
K3NO
to
|
i»
WAtTEWAm
FAQUTT
I
Iftl
4 moouerra
HKmouAun
WATMMOyillM1
KHD
(xetsa
«n
•isvciiTO
WASTIWATIR
TMAraiMr
H M
HANI IVAA
1
4
._-J 1M
134
awwoowM
9
tns
VAT
Na
4
in
9
«•*••
m
W»M>
I4MH
t
f
-jsvstm
WAins
. CMHMI?
- OMIN
CONOtnONS;
AU. AOWC IM AViMAaK Q
AVDUMI ANIWMU. COC'UltO TOW1II (VAKMTION
caouMOTOwmeoMeiKnunoM ti crctt*
COOUMO TOM* owr a«» OP et ne. WATW nan
mnvaii * w«o tar ANWAI AVUWOI
Figure VII-23
FLOW DIAGRAM FOR PLANT 0822
323
-------
The dry fly ash handling system for the plant removes fly ash from the
boiler economizer hoppers and precipitator hoppers on Units 1 and 2
and transports the ash to a common fly ash silo where the ash is
loaded into trucks. The trucks then transport the ash back to the
mine site for burial. The system is pressurized and uses air as the
conveying media. Ash conveying blowers supply the conveying air. Fly
ash is fed into the system from the economizer and precipitator
hoppers by "nuva" feeders in a programmed sequence and the air flow
carries the ash to the plant fly ash silo. Exhaust air from the silo
is vented by the fly ash silo vent fans to the Unit 2 precipitator
flue gas inlet manifold.
Three positive displacement blowers are used to drive the fly ash from
the ESP and economizer hoppers to the plant storage silo. These
blowers include one spare. Blower 1 serves Unit 1; blower 3 serves
Unit 2; and blower 2 is the spare. These blowers each have^ a capacity
of 2,900 ACFM at 13.5 psig and are driven by 250 hp, 480-volt, 3-
phase, 60-hertz, 1,800-rpm electric motors. A 10-inch line is run
from the Unit 2 blower to the Unit 2 precipitator and economizer
hoppers. Each of the two precipitatbrs contain 16 ash hoppers and the
economizer contains four . hoppers. The conveying air is piped to
service nine groups of hoppers, each group containing four hoppers.
Fly ash from each group of four hoppers is automatically fed by "nuva"
feeders in a programmed sequence contained in the fly ash control
system which empties the hoppers in each group one at a time.
The fly ash system for Unit 1 consists of one four-branched conveyor,
which, automatically conveys fly ash from 24 precipitator "nuva"
feeders. The "nuva" feeders are essentially airlocks which utilize
fluidizing stones to achieve better dust flow characteristics from the
hopper to the pressure pneumatic conveyor. "Nuva" is a trade name
used by United Conveyor for their air.locks. The air displaced by ash
in the precipitator feeders is vented through a bag filter to the
atmosphere. Air displaced by the economizer ash is vented back into
the hopper.
From the hoppers the fly ash and conveying air travel through a 10-
inch line into the plant fly ash silo. The conveying air is vented
from the silo through a 16-inch line by three fly ash silo vent fans.
The air is piped through one of two 14-inch lines leading to the Unit
1 and 2 precipitators. The three silo vent fans are driven by 50-hp,
480-volt, 3-phase, 60-hertz, 1,800-rpm electric motors. The rotary
unloaders condition the fly ash which is then hauled to the mine for
disposal. Ash water from the bottom ash surge tank is pumped to the
fly ash silo by two fly ash unloader pumps through a 6-inch line.
The most significant maintenance item is the blowers. These have
required two mechanics full time due to the erosion of the com-
pressors. Other problems occur with pipe fitting leakage due to pipe
expansion. The pipe expands because of the high temperature (700 F.)
fly ash which is being conveyed.
324
-------
This system was installed along with the bottom ash system in 1974 as
a retrofit to Unit 1 and as new to Unit 2. No particular problems
were encountered in this retrofit. Some downtime was required to
hookup the fly ash conveying pipe and airlocks to the ESP and
economizer heppers. Also, the old wet sluicing pipe needed to be
taken out. No pipe was reusable for fefee*^f4y-ash system.
Plant 3203. This plant is a 340-MW western bituminous coal- burning
facility which fires a moderately low-sulfur coal (average 0.6
percent) with an average ash content of 12 percent. The availability
of the three boilers has historically averaged 86 percent annually.
The dry fly ash handling system currently in use is a pressure system
designed and installed by United Conveyor Corporation. Fly ash is
generated by three pulverized dry bottom coal-fired units. Operating
conditions at the plant indicate that ; .80 percent of the coal ash
leaves . the boilers via the flue gas stream. This corresponds to
approximately 385 TPD of fly ash being generated. Approximately 0.3
percent of this fly ash is collected -in the economizer hopper; the
ash collected there is sluiced to the bottom ash handling system at a
rate of 1 TPD. The majority of the remainder of the fly ash is
collected in mechanical collecting ..devices, cyclones, with an
efficiency of 75 percent. The remaining 25 percent is collected in
the air preheater and stack hoppers. The fly ash collected is then
conveyed under pressure to a storage silo for commercial use or
disposal. Approximately 250 TPD of the fly ash is sold dry, or
unconditioned, to a cement company as an additive for $1 per ton. The
remainder is conditioned and trucked to an on site landfill.
The pressure system is diagrammed in figure VII-24. There are six
hoppers per.mechanical collector which feed through an airlock device
into a pressurized (8-10 psig) pneumatic conveying line which leads to'
the storage silo. The distance from the cyclone hoppers to the
storage silo is approximately 500 feet. The volume of the silo is
30,000 cubic feet and the pneumatic lines leading to the silo are 6 to
7 inches in diameter. This silo volume provides approximately a 2-day
storage capacity and therefore requires dumping several times a week.
The equipment which required the most maintenance during the past 4
years of operation of the unit were (1) the blowers and (2) valves and
elbows. There were no real problems with the rest of the system.
The motivation for retrofitting this system was twofold: a general
water shortage problem existed and approximately 250 TPD of the fly
ash was a saleable product at a rate of $1 per ton. At the time the
pressure dry fly ash. system was installed in 1975, a dewatering bin
system and a third unit boiler were also installed.. A 2-week outage
for Units 1 and 2 was incurred when these retrofit systems were
installed. :
Utilization of the Systems. Data from the 308 survey were used to
evaluate the distribution of fly :ash handling systems for the
following parameters: ;
325
-------
6 hoppers per mechanical collector
Air prelieater
hopper stack
hopper
blowers
ov
VVVVVV V V
Vent r-j
Filter! * '
storage
silo
6 and 7-lnch
lines
Figure VII-24
PRESSU1E FLY ASH HANDLING SYSTEM FOR PLANT 3203
-------
- fuel type,
boiler type,
- location,
9-~
size, and
intake water quality.
Fuel Type. The most important fuel type is coal. This fuel type
accounts for 74 percent of the fly ash handling systems as shown in
figure VI1-25. Dry fly ash handling systems are as common as wet
once-through systems for coal-burning facilities and represent 34
percept of all ash handling systems. Wet recirculating systems,
however, are much less common, representing only 2 percent of all ash
handling systems. This distribution does not change significantly
among coal, gas, and oil-burning facilities. .Thus, it seems that fuel
type has little effect on the type of ash handling system used.
The distribution of ash handling systems among different coal types is
shown in figure VII-26. Coal type does not seem to significantly
affect the distribution of systems. Bituminous coal facilities, by
far the most common of the three coal types considered, are split
between dry and wet once^-through systems. Wet recirculating systems
are rare.
Boiler Type. Three major boiler types are considered in this
analysis: cyclone, pulverized coal, and spreader stoker units.
Figure VI1-27 indicates that the type of boiler does influence the
distribution of fly ash handling systems. Dry fly ash units are
outnumbered three-to-one by wet once—through systems for cyclone
units. Eighty to 90 percent of the ash produced by a cyclone boiler
is bottom ash. Since the cyclone boiler is a slagging boiler, the
bottom ash is usually handled wet; thus, it is not surprising that the
remaining 10 to 20 percent of the ash is more frequently handled wet.
Wet recirculating systems are rare (less than 2 percent of the systems
reported) for cyclone boilers, as well as for pulverized.and stoker
boilers. Pulverized coal units seem to have the same distribution of
fly ash handling systems as discussed previously for fuel types. Dry
systems are very common (almost equal in number to wet once- through
systems), and wet recirculating systems are rare. Spreader stoker
units use a much larger proportion of dry systems than wet once-
through systems. Wet recirculating systems are rare.
Location. The distribution of fly ash handling systems for each of
the 10 EPA regions is shown in figure VII-28. A map displaying the
EPA regions is provided in figure VII-29. The distribution indicates
that there are some regional variances in the distribution of fly ash
handling systems.
Regions I through III show a slightly greater frequency of dry systems
(as opposed to wet once-through) and very few instances of wet
327
-------
u
03
?s
M
eo
R
*O
§
W
«
<
0
SO
CO
4J
%
O
30
20
id
•M
**
»*
*»
t*
4*
11
«*
**
*
*
*
*
*
7
II
0 1)
/ t
VI U
o n
T
H U W I*
/ o i« n
* t /
u
it
T
«•*
*4
44
*»
4:
4 *4
• **
ft !»
y
w
o
T
i
i
U M
/ /
U A
R
»*
k»
4
#
*
*
* »*
H M W
o H n
T /
W
0
f
** **
i* 4*
n o n M M
/ / / o
u u A r
0 ,H
T
u u
R H
/
H
U
T
t*
** »»
• *• **
*» *« *«
n • u n N w u i)
.///ORB
w y ft T /
OR i H
T 0
T
Major Fuel Type
Keys D: Dry Fly Ash Handling System
WOT: Wee Once-Through Fly Ash Handling System
WR; Wee Reeirculating Fly Ash Handling Syscem
NOTE: Plants which could not be identified under a sub-
group appear in a subgroup on the far left o£ the
chart, designated by a "," or by " "..
Figure VII-25
DISTRIBUTION OF FLY ASH HANDLING
BY MAJOR FUEL TYPES
328
-------
30
4- t
i1 ;
4J f
S, 25 <
M *
I i
d an <
c *
a :
43 *
« 15 +
> * **
*-l t »*
* **
**
»«
** ' '
- »
t
*
• t
, *
. * **
,» » 4* **
,, • 4 »» *«
Tt ' * *• ** -*» *« **
ifiuNHUw uuutiwwti uunuuwy
/ / / 0 (. ft ///OP« / / / 0 R K
MKAT / HHAf / MyAT /
Oii U OH M U« W X2901
1 0 T 01 0
T T J.
Key: Ds
WOT:
WE:'
nir * *— U"
Type of Coal
Dry Fly Ash Handllmg System
Wec_ Once-Through Fly £sh Handling System
Wetf Recirciilating Fly. Aah'Haii'dl'ing System
SUII
CTP
NOTE: Plants which could not be identified under a sub-
group appear in a subgroup on the- far left of the
chart, designated by-a "." or by " ".
..-.v . Figure ¥11-26
DISTRIBUTION OF" ILY ASH HANDLING SYSTEMS BY COAL TYPE
329
-------
ra
m
g
H
•a
a
cB
»
rG
SI
<
3>
09
«
a>
u
M
41
3(1
t
20 +
*
x
in *
*
*
je
* **
0 U
/
U
0
T
D
/
U
n
»»
, f
• 4
U U
0 R
T
U
R
/
V
Q
T
*4
• *
4*
it-
44
44
« (
**
*»
4*
4*
44*
4*
**
n
44
4*
n
/
u
0
T
4*
»*
44
44
44
44
44
44
44
*»
4*
44
44
4*
*•
44
44
n w
/ 0
U T
R
»*
H hi
n R
/
u
a
T
44
44
44
4*
44
44
D
4*
0 0 U
/ / 0
U W T
U A
T
U U
R R
, /
U
0
T
Cyclone
Pulverized Coal
Spreader Stoker
Kay: D:
TOT:
WR:
Major Boiler Type
Dry Fly Ash Handling System
Wet Once-Through Fly Ash Handling System
Wat Recirculatzng Fly Ash Handling System
NOTE: * Plants which could not be identified under a sub-
group appear in a subgroup on the far left of the
chart, designated by a "." or by "-—".
Figure VII-27
DISTRIBUTION OF FLY ASH HANDLING SYSTEMS
BY MAJOR BOILER TYPES
330
-------
CO
CO
t
I*6*
w *
M *
M2B *
if *
•H /
1 '
.3 IS »
33 i
.C <
ca >
jf
>i 10 1
m j
•1 1 j
0 1
dT 1 »
00 # f . *
-S * i r * j «
|jj U 11 it V -M i) «I U M M U II (i U U
A< //OH / / U « / / 0 fl
U U r DM! « W T
it n OH o a
r T i
*
*
*
f
*
*
t
*
9
*
^
1 t
» f -
* 4
4- * f1 $
11 !) 0 ti y U Jl ti M M
//OR //on
U U 1 H W 1
on u it
i i
t
t
f -
^
*
1
t
4
|
* *
*
t
*
*
t
* *
4 t
* t
1 t
» 4
* * t
£ A K * 4 «
* f ¥ f v
UPOUM OUrHUUU r
//Of. / , / o n it
U U 1 W t' ft I /
o ft ON ti
I I «
i
t -9 -f
4:
*
* , *
- * *
4 *
4 *
* *
*
*• I
* *
*
t
« r
*
*
*
* .
; *
*
*
t
. - » . . .- . t . . .
* *
4 4 * 4 44 *
1 1) U li V H H II |> b M U M U U II O H W U U 0 O U H H U U
/ / / Jl H H / / / 0 (1 N ///OB « / / / b H H
U II A 1 / WUAI ./ *UUAI / UUftT /
U H U 0 It U O It U 0 ft ti
I 01 01 0 T D
II f t
EPA Region
Key; D: Dry Fly Ash Handling System
WOT: Wet Once-Through Ply Ash Handling System
WR: Wet Recirculating Fly Ash Handling System
NOTE: Plants which could not be identified under a sub-
group appear in a subgroup on the far left of. the
chart, designated by a "." or by " ".
Figure VII-28
DISTRIBUTION OF FLY ASH HANDLING SYSTEMS.BY EPA REGION
-------
Figure VII-29
EPA REGIONS
-------
recir ciila ting systems. Oil-burning facilities are more common in the
Northeast. The low ash production rate of oilburning facilities may-
be one explanation for the increased use of dry fly ash systems. In
addition, insufficient land for ponding may also contribute to the
choice of dry^over wet handling.
In Region IV, wet once-through systems are most commonly used. Dry
fly ash systems represent 3 percent of all ash handling systems. Wet
once-through systems account for 18 percent of all ash handling
systems. The high occurrence of wet once-through systems may be due
in part to the greater availability of land for ponding rather .than
some restriction on the use of dry systems.
In Regions V, VI, and VII, dry systems are competitive with wet once-
through systems.
In Regions VIII and IX, the proportions of dry and wet recirculatirig
systems are considerably higher than those of any other region. This
reflects the need to conserve water in these areas. The only systems
reported in Region X are dry fly ash systems. Again, this is a result
of the scarcity of water in the West.
Plant Size. Plant size is expressed in plant nameplate capacity. The
distribution of fly ash handling systems by various plant size
catagories is presented in figure VII-30. Category 1 is dominated by
dry fly ash systems. This probably reflects the dominance of stoker
boilers among low capacity plants. As plant capacity increases above
100 MW, wet once-through systems become competitive with dry fly ash
systems. For plants greater than 500 MW, the percentage of wet once-
through is slightly greater than the percentage of dry systems.
Intake Water Quality. Intake water quality was measured as total
dissolved solids (TDS). The distribution of fly ash handling systems
by intake water quality is presented in figure VII-31. No significant
differences in the distribution of fly ash systems are apparent among
any of these categories.
Retrofitted Dry Fly Ash Systems. Table VII-14 presents a list of
plants which have been identified as having retrofitted dry fly ash
systems.
Partial Recirculating Systems. The wet handling of fly ash is
achieved by sluicing the fly ash from the collection device, ESP or
cyclone hopper, to a pond. Settling of the fly ash typically occurs
in primary and secondary ponds. A third settling area, usually
referred to as a clear pond, is used if the sluice water is to be
recycled. Total recirculation of the ash pond transport water is a
zero discharge system. If less than total recycle occurs, the system
is defined as a partial recirculating system.
333
-------
teasf
03
CO
60
•H
i-l
T3
fd
m
15
(0
^5
>»
i-i
fw
*4
O
01
60
ra
1
M
0.
18 4>
$
*
i
IS *
*
a
£
12 +
*
t
*
9 +
jt
*
, *
6 +
£
* *«
* **
34-**
* »*
* i*
* »»
0
**
**
**
**
**
• *«
»*
'4* • »«
** **•'
«« **
4i **
** **
«» **
••* *»
»* »«
** **
4* 4* **
»* 4*' *«
4* 4* »»
44 » t t«
»t ** 4* ** 4*
*» ** ** ** *«
DDHUUU II DUN MUM DDU
/ / *; o R H xxxonn xx
u u ; r / WHAT / uu
OR H 0 K u 0 l<
T 01 0 T
T T
*4
**
**
<*
»4
it
4- 4
**
*4
4*
**
**
**
**
4*
**
• *
4*
**
44
4* 4*
4* **
N U U
/OR
A T
44
4.*
4*
**
^ ^
** ,
**
*4
**
•»» "
»*
4* .
**
**
4-4
*t
«4>
*4
*4 ' •«
44 44
44 44 4«
« o u n
B XX
X H U
u on
0 I
T
*»
*4
**
<*
4*
*»
4*
**
**
4*
4*
**•
«*
4t
*4
**
«4
0*
*4
4*
4*
4+ t*
4* *4
4* **
M « «
X* 0 H
A T
y
H
/
y
0
T
/_..—,—». , ,. » 2 -— / * . 3 . 1 i H ——t
<25 25-100 100-500 >500
, Nameplate Capacity (MW)
K*y; Ds Dry Fly Ash Handling System
WOT: Wet Once-Through Fly Ash Handling System
WR: Wee Recirculating Fly Ash Handling System
HOTS: Flanta which could not be identified under a sub-
group appear in a subgroup on the far left of the
chart, designated by a. "." or by " "",
Figure VII-30
DISTRIBUTION OF FLY ASH HANDLING SYSTEMS
BY VARIOUS PLANT SIZES
334
-------
0)
OT *
ap i !i t
•H *
T3 ,
g»» *
a • *
_ *
•s *
"^J *J *
I
rt >
fa »•
b *
0 »
/
U *
aa t *
U f
a *
y *
^J u & a it u u u
/ / / u H K
M ' A T /
u • u
T o
i
t '
* *
* »
* *
* »
* » *
* » •- *
« » » +
+ * * *
* 4 » *
» » »
• » »
* |
* *
* *
t *
+ *
* *
» »' » » « *
*
f
V
* T
f t
T t
* * f . *
II 11 «i U U M M U it U M U U U IJ U 0 N U U U 0 0 0 M W U W
///oui< / / / a a n /-//OUR ///OBH
UllAT / MMAf / U U A T / M«4f /
OK U U H U 0 H U 0 K U 1290)
T u T u 1 0 T 0
T T T T
400
io-3o o-6
>600
Total Dissolved Solids (ppm)
Key. DJ Dry Fly Ash Handling System
WOT: Wet Once-Thzough Fly Ash Handling System
WE,: Wet Reeirculating Fly Ash Handling System
NOTE: Plants which could not be .identified-under a sub-'
group appear in a subgroup on Che far left of che
chart, designated by a "." or by "---".
Figttre VII-31
DISTRIBUTION OF FLY ASH HANDLING SYSTEMS
AS A FUNCTION OF INTAKE WATER QUALITY
335
-------
Table VI1-14
PLANTS WITH RETROFITTED DRY FLY ASH HANDLING SYSTEMS
Plant/Utility
Gallatin/TVA
John E« Amos/
Appalachian Power Co.
Kirk/Black Hills
Power & Light Co.
Ben French/Black
Hills Power & Light Co.
Fisk/Commonwealth
Edison Co.
Bailly/No. Indiana
Public Service Co.
Ashtabula/Cleveland
Electric Illuminating Co.
Avon Lake/Cleveland
Electric Illuminating Co.
Eastlake/Cleveland
Electric Illuminating Co.
Lake Shore/Cleveland
Electric Illuminating Co.
Coffeen/Central
Illinois Public Service
Reid Gardner/Nevada
Power Co.
Hayden/Colorado-Ute
Cherokee #3/Publie
Service of Colorado
Bowen/Georgia Power
Company
Arkwright/Georgia
Power Co.
McDonough/Georgia
Power Company
Port Wentworth/
Savannah Electric & Light
Location
(EPA Region)
Summer, TN (IV)
Kanawha, WV (III)
Lead, 3D (VIII)
Rapid City, SD (VIII)
Cook, IL (V)
Porter, IN (V)
Ashtabula, OH (V)
Lorain, OH (V)
Lake, OH (V)
Cuyahoga, OH (V)
Montgomery, IL (V)
Capacity (MW)
1255.2
2932.6
31 .5
22.0
547.0
615.6
640.0
1 ,275.0
1,257.0
514.0
1,005.5
Moapa Clark Co., NV (IX) 340.8
Hayden, CO (VIII)
Adams, CO (VIII)
.Bartow, GA (IV)
Bibb, GA (IV)
Cobb, GA (IV)
Chatham, GA (IV)
447.0
801.3
2,547.0
181 .0
598.0
333.9
336
-------
Partial Recircula'ting Systems
Process Description. A generalized schematic of a typical partial
recirculating system is shown in figure VI1-32. Sluiced ash is pumped
to the primary and secondary pond and flows to the clear pond from
which water is recirculated by the main recirculation pumps to the
main sluice pumps to be used as dilution water. A portion of the
clear pond overflow is discharged.
There are various methods of sluicing the fly ash from the collection
point. A typical method is illustrated in figure VI1-33. Fly ash
from the ESP hoppers is vacuum conveyed through the vacuum producer
where it is slurried with the high-pressure water used to create the
vacuum for conveying. This slurry is discharged through an air
separator. From the air separator, the sluiced fly ash may flow by
gravity to the pond or to a mix tank before it is pumped to the pond
site. Slurry pumps are necessary when the ash slurry is pumped a
great distance to the pond, which is often the case. Many ponds are
typically 1,000 to 3,000 feet from the hoppers.
Equipment. The equipment associated with dry conveying, i.e., all
equipment up to and including the vacuum producer, is discussed in the
sections on dry fly ash handling. The major equipment discussed in
this section includes:
air separator, :
- pumps,
- conveying pipe, and
ponds.
Air Separator. A typical air separator is shown in figure VI1-34. A
wide variety of separators, unlined or with basalt linings, are
available for single and multiple systems.
Pumps. Slurry pumps may be centrifugal pumps or ejectors (jet pumps).
Either pump requires considerable dilution at the suction in order to
provide a slurry that can be pumped. For the same discharge quantity
and discharge head, a centrifugal pump is about 40 percent more
efficient than a jet pump without considering the efficiency of
auxiliary pumping equipment which supplies the ejector nozzle (40).
Jet pumps are generally more favorable for slurry handling than
centrifugal pumps because of the relative ease with which-they can be
serviced, even though such service may be required much more
frequently than for a comparable centrifugal pump. - The higher
maintenance requirement is due to higher operating pressure in the
ejector nozzles.
Hard metals are employed in the construction of both types of pumps in
areas where abrasion is most severe. It is desirable to maintain
velocities as low as possible within the limits of pump efficiency to
337
-------
Sluiced Fly Ash
Main Sluice Pump
Main
Recirculation
Pump
oo
Discharge
I
Final Pond
(Clear Pond)
Settling Ponds
Figure VII-32
GENERALIZED, SCHEMATIC DIAGRAM OF A PARTIAL RECIRCULATION FLY ASH
HANDLING SYSTEM
-------
VO
Fly Ash Hoppers
V V V
V V V
X
Vacuum
Producer
Option 1
Mix
Tank
To Ponds
Air
Air
Separator
Option 2
Flow by
Gravity to
Pond Area
Slurry Pump
Figure VII-33
A TYPICAL METHOD OF SLUICING FLY ASH FROM COLLECTION POINTS
-------
CUTLTT-*.
4. SUPPORTS
VENT OPCHIN8
IMUT
INLET VOLUTE
CASTING
Figure VII-34
TYPICAL AIR SEPARATOR IN A PARTIAL RECIRCULATING
FLY ASH HANDLING SYSTEM
Reprinted from A Primer forAsh Handling by Allen-Sherman-Hoff
Company by p ermi s s ion o f "AH en - Sherman- Ho f f Company, a Division
of Ecolaire. Year of first publication: 1976.
340
-------
reduce abrasion. A veloctiy of 40 to 50 feet per second maximum
through a jet pump is desirable. In the case of centrifugal pumps,
the impeller peripheral speed should not exceed 4,500 to 5,000 feet
per minute (40).
When system heads exceed about 100 feet, jet pumps are generally
ineffective since series pumping is not practical. Centrifugal pumps,
on the other hand, can be conveniently placed in series for high-head
requirements (40).
Centrifugal pumps are generally used for recirculation. Clarity of
recirculated water does not present a wear problem to a centrifugal
ash handling pump.
Pipe. The pipe conveying an ash slurry is similar to that used in dry
fly ash systems. Basic pipe for ash handling service has a Brinnell
Hardness Number (BHN) of 200; fittings have a BHN around 400. Various
hardnesses are available with cost usually increasing in proportion to
hardness (40). Centrifugally cast iron pipe is by far the most widely
used pipe for wet systems because of its ability to withstand the
corrosive and erosive condition often encountered in ash handling
(39). . This type of pipe is available from a number of pipe
manufacturers. Basalt- lined pipe is another fairly common pipe used
in ash handling systems. The basalt lining is formed from volcanic
rock which is melted and shaped into a liner for the pipe. Basalt
provides improved protection from abrasion; however, it is generally
less resistant to impact caused by turbulent conditions at bends in
the pipe. In fact, some plants have used basalt-lined pipes for
straight sections and cast , iron for bends. Basalt also protects
against corrosion by sealing the pipe from the corrosive conditions
within. One drawback from this pipe is that it is more expensive to
install because it requires a lot of shaping and cutting. Some firms
are marketing a ceramic pipe for use in ash handling systems. This
type of pipe is fairly new and has not been universally accepted by
the utility companies. Fiberglass pipe has also been used in ash
handling systems. Like basalt- lined pipe, fiberglass pipe has fairly
high installation costs because it requires cutting and shaping.
Ponds. The primary pond or settling area may not necessarily be a
pond, per se, but can be a run-off area for removal of the larger ash
particles. The sluice water may then overflow via gravity to a
secondary pond for further settling. Overflow from the second pond
would flow to a clear pond which serves as a holding basin for
recirculation water. To be effective, ponds must cover a considerable
area to allow sufficient retention time for settling of the ash in the
conveying water. For bottom ash, volume in the storage basin should
be sufficient to provide at least 1 day's retention time. Because of
its slow settling rate, fly ash requires a larger pond to provide
longer retention time than for bottom ash.
Maintenance. For those sections of a partial recirculating system
which involve dry conveying, maintenance of the equipment is the same
as for vacuum and pressure dry fly ash handling systems. Abrasive and
341
-------
corrosive wear on the pumps and conveying lines handling the ash
sluice is a major source of maintenance problems. Most of the wear on
pipe lines occurs along the bottom because most of the solids in the
slurry are carried along the bottom. To distribute the wear along the
bottom, many plants rotate their cast iron pipe lines regularly. The
other area of major maintenance are the settling ponds. Generally,
these ponds must be dredged regularly to remove settled ash for
landfill disposal.
Retrofitting. The motivation for retrofitting a partial recirculating
system onto an existing ash pond system may be either a water shortage
or regulations governing wastewater effluents. Essentially no
equipment must be removed in order to retrofit a partial recirculating
system other than rerouting of old pipe near the sluicing pumps where
hook up would occur. Old pipe in the plant may be used in some
instance to help defray the capital cost of the new pipe.
Recirculation pumps may be required to move the pond water to the
existing ash sluice pumps. Some downtime may be required for hook up
of the recycle line to the main sluice water conveying pumps.
Trip Report. One of the plants visited in the effort to define
various bottom ash and fly ash handling practices had a partial
recirculating system for fly ash. Plant 1809 is a 736 MW electric
power generating station. Four of the seven boilers currently in
operation burn bituminous coal from Bureau of Mines Districts 10 and
11 with an ash content of 10 to 12 percent. The boilers are of the
wet bottom, cyclone type and produce a relatively large amount of
bottom ash slag. The plant utilizes a wet recirculating ponding
system to handle both fly ash and bottom ash. Water is obtained from
a nearby creek for use in the sluicing operation. Figure VII-35
presents a flow diagram indicating separate fly ash and bottom ash
holding ponds. There are two primary, two secondary, and one final
pond.
The fly ash is jet sluiced from the ESP hoppers from Units 4, 5, 6,
and 12 to one of two fly ash settling ponds. The sluice water from
the fly ash pond is overflowed by gravity to the final pond for
holding and recirculation to the jet pumps and ESP hoppers. The final
pond also contains bottom ash sluice water. The same discharge point
exists for the fly ash system as for the bottom ash. The final pond
and recycle lines were retrofitted in 1974 in order to collect the
discharge streams in one location for treatment purposes. The
distance from the ESP hoppers to the fly ash ponds is approximately
1,500 feet. The fly ash is sluiced six times a day in 12-inch
diameter sluice lines of cast basalt construction for 45-minute
sluicing intervals. Thirty fly ash hoppers collect the fly ash at the
ESP for Unit 12 and 12 hoppers collect for Units 4, 5, and 6.
Since the coal-fired boilers are all cyclone type, a small percentage
of fly ash is produced relative to the bottom ash. In 1978,
approximately 48,600 tons of fly ash was produced which represents 26
percent of all the ash produced. This fly ash is cleaned out of one
pond annually and is trucked to a landfill site by an outside firm.
342
-------
co
Sample 2
Overflow
(2) Fly Aah Ponds
Botto* Aali
Storage Ground
(2 primary, 1 secondary pond)
>Diacliarge (f)
EJ * ii j Sample 3
Final Pond
Illgll Pressure
(200 psig)
(2 pumps)
Lou Pressure
(50 palg)
(2 pimps)
NOTE: Approximately 1/4 mile from alag tanks
and ESP' hoppers to the pond area.
i Jet pumps
(200 pslg)
Figure VII-35
ASH HANDLING SYSTEM FLOW DIAGRAM AND SAMPLING LOCATIONS FOR PLANT 1809
-------
The sluicing jets-and recirculation pumps are the primary maintenance
items for this system. Minor erosion has caused some maintenance
problems. Scaling and corrosion have not been found to be prevalent.
Physical/Chemical Treatment of Fly Ash Pond Overflows from Wet, Once-
Through Systems '
Wet, once-through systems with ponding are commonly used for ash
handling. Typically, sluiced fly ash is sent to primary and secondary
ponds arranged in series where settling of the larger particles
occurs. The overflow from the secondary pond is then discharged.
Physical/chemical treatment of the ash pond overflow may be employed
to remove trace metals before the sluice water is discharged. This
section describes physical/chemical treatment and the equipment
involved and assesses the effectiveness of physical/chemical treatment
in removing arsenic, nickel, zinc, copper, and selenium from ash pond
overflows.
Process Description. Metals typically are removed from wastewater by
raising the pH of the wastewater to precipitate them out as
hydroxides. Lime is frequently used for pH adjustment. A flow diagram
of a typical physical/ chemical treatment system for metals removal
using lime is shown in figure VII-36. The major equipment items
include a lime feed system, mis tank polymer feed system,
flocculator/clarifier, deep bed filter, acid feed system, and another
mix tank. The underflow from the clarifier may require additional
treatment with a gravity thickener and a vacuum filter to provide
sludge which can be transported economically for landfill disposal.
Typically, wastewater pH's of 9 to 12 are required to achieve the
desired precipitation levels. Lime dosage rates, flocculant dosage
rates, and clarifier design parameters are determined by jar tests and
onsite pilot test on the ash sluice water discharge.
Equipment. Typically, hydrated or pebble lime is used to raise low pH
systems to the desired pH. Hydrate lime feed systems are used when
lime feed rates are less than 250 pounds per hour (41). Pebble lime
feed systems are used for lime feed rates greater than 250 pounds per
hour. A typical pebble lime feed system is illustrated in figure VII-
37. For larger systems, the reduced chemical cost and ease of
handling of pebble lime make the pebble lime systems more desirable.
Wastewaters which have a pH greater than 9 after lime addition will
require acid addition to reduce the pH before final discharge. The
system differs from lime feed systems in that the acid is delivered to
the plant as a liquid. The feed system equipment must be constructed
of special materials, typically rubber or plastic-lined carbon steel
or stainless steel alloys. Acid addition rates for pH adjustment are
highly dependent upon wastewater flow, pH, alkalinity, and type and
strength of acid. Dosage rates are determined by laboratory or onsite
testing.
344
-------
Initial pH
Adjustment
Clarification
Filtration
Final pH
Adjustment...
lime Feeder
Polymer Feeder
Acid Feeder
Ul
Waste
Water
M
P
''
^
1
1
a
1
* *
1
^
Clar
f -•• -
Ifier
..
i
Det
Bee
Fll
*P
i
t<
Underflow to
Thickener and
Vacuum Filter
D
CO
Mix Tank
Figure VII-36
FLOW DIAGRAM OF A TYPICAL PHYSICAL/CHEMICAL TREATMENT SYSTEM FOR
METALS REMOVAL USING LIME
-------
.OUST COLLECTOR
•FILL PIPE
8ULX STORAGE
BIN
\
BIX GATE
FLEX ISLE
CQHNECT1QH
SOLEHOIO
VALYEx
SCALE
OR SAMPLE CHUTE
ROTAMETERS
SLAKIH6 WATER
DILUTION WATER
UXEK
\ PRE5
**\ ' . • «
\t *
y
i—
-LEVEL j
PROSES '
f 1 " f*
SURE
:EO
it
HOLDIHG
HCTERIMG
PRESSURE
YALYE
Figure VII-37
TYPICAL LIME FEED SYSTEM (41)
346
-------
For wastewaters which have a pH'of less than 6, mixers and mixing
tanks are made of special materials of construction (stainless steel
or lined-carbon steel). For wastewaters with pH's greater than 6,
concrete tanks are typically used.
Polymer addition may be required to enhance the settling charac-
teristics of the metal hydroxide precipitate. Typical polymer feed
concentrations in the wastewater are 1 to 4 ppm. The required polymer
addition rate is determined using laboratory or onsite testing.
The metal hydroxide precipitate is separated from the wastewater in
the clarifier. Unlike settling ponds, these units continually collect
and remove the sludge formed. To determine the size of the unit
required, laboratory settling tests are required. These tests will
define the required surface area. Typically, a 2- to 3-hour
wastewater retention time will be required (39). Clarifier diameters
range from 10 to 200 feet with average depths of 10 to 15 feet (39).
Filters are typically used for effluent polishing and can reduce
suspended solids levels below 10 mg/1. Figure VI1-38 illustrates a
typical deep bed filter. Sand or coal are the most common filter
media. Hydraulic loading rates of 2 to 20 gpm per square foot of bed
cross sectional area are common. High removal efficiencies require
lower hydraulic loading rates. For general design purposes, a
hydraulic loading of 5 gpm per square foot of filter area is typical.
As the filter medium becomes plugged with suspended solids, the
pressure drop across the bed increases. At 10 to 15 psi bed
differential pressure, the bed is automatically backwashed with water
and air to remove the trapped suspended solids. Typically, 6 to 8
scfm of air and 6 to 8 gpm of water are required to backwash a square
foot of bed cross section. Total backwash water consumption is
usually in the range of 150 to 200 gallons per square foot of filter
surface area. Backwash frequency can range from 1 to 6 times per day
for normal operations. For backwash systems using only water, 15 to
20 gpm per square foot of filter area is requred with a backwash water
rate of 400 to 500 gallons per square foot of filter area (39).
Gravity thickeners are essentially identical to clarifiers in design.
Sludge enters the middle of the thickener and the solids settle into a
sludge blanket at the bottom. The concentrated sludge is very gently
agitated by a moving rake which dislodges gas bubbles and keeps the
sludge moving to the center well through which it is removed. The
average retention time of solids in the thickener is between 0.5 and 2
days (42). Most continuous thickeners are circular and are designed
with depths of 10 feet (42)r. In thickening of lime sludge from lime
tertiary treatment, incoming sludge of 1 to 2 percent solids has been
thickened to 8 to 20 percent solids at solids loadings
Vacuum filtration is a common technique for dewatering sludge to
produce a cake that has good handling properties and minimum volume.
The vacuum filter typically consists of a cylindrical drum that
rotates with the lower portion of the drum submerged in the feed
sludge. The drum is covered with a porous filter medium. As the drum
347
-------
RAW
WATER
STABILIZING
LAYS?
MEDIUM
SUPPORTING
LAYER
AIR
DISTRIBUTION
PIPES
CLEAR WATER
WASHWATSR
CONDUITS
CLEAR
WATER
FILTERING
FILTER 3E0
FINE
SUPPORTING
LAYER
COARSE
SUPPORTING
LAYER
M-aLOCXS
COVER
PLATES
FILTRATE OUT «-{
WATER IN
Figure -VII-38'
DEEP BED FILTER
348
-------
rotates, the feed liquor is drawn onto the filter surface by a vacuum
that exists on the drum interior. The liquid passes through the
filter and the sludge forms a cake on the surface of the drum. The
cake is separated from the filter by a scraper. Generally, vacuum
filters are capable of dewatering a 2 to 4 percent solids feed to a
filter cake with a concentration of 19 to 36 percent solids. Typical
solids loading rates may vary from 3 to 14 pounds per hour per square
foot for lime sludges.
Effectiveness. A review of the literature on trace metals removal
from various wastewaters using physical/chemical treatment was
conducted for arsenic, nickel, zinc, copper, and selenium. The
results of this literature review and the results of bench-scale
studies of trace metal removals in ash pond overflows are discussed in
this subsection.
Arsenic. Arsenic and arsenical compounds have been reported as waste
products of the metallurgical industry, pesticide production,
petroleum refining, and the rare-earth industry. High levels of
arsenic also have been reported in raw municipal wastewater. Arsenic
occurs in four oxidation states, but it is found primarily in the
trivalent (arsenite) and pentavalent (arsenate) forms. It is found in
organic and inorganic compounds. The inorganic compounds are
generally more hazardous than the organic compounds, and the trivalent
form is generally more toxic than the pentavalent form. Information
on the conventional coagulant and lime-softening processes indicates
that removal is valance dependent (44).
While only limited information is available on the concentration of
arsenic in industrial wastewater and on current treatment processes,
more up-to-date information is available on the removal of arsenic in
municipal wastewater. One study (45) of the lime softening process
indicates removals of approximately 85 percent. In particular, the
lime softening process was found to reduce an initial arsenic
concentration of 0.2 mg/1 down to 0.03 mg/1. Simple filtration
through a charcoal bed reduced the same initial arsenic concentration
to 0.06 mg/1. Results from another pilot plant study (45) for removal
of arsenic in municipal wastewaters indicate removal efficiencies of
96 to 98 percent (final effluent concentration = 0.06 mg/1). The
treatment involved addition of coagulant (ferric sulfate), followed by
flocculation, settling, dual media filtration, and carbon adsorption.
The Water Supply Research Division (WSRD) of EPA recently completed
pilot plant studies on arsenic removal (44). In one study, sample
effluents were pumped to a rapid-mix tank then flowed by gravity
through coagulation, flocculation, and sedimentation steps to filter
columns. WSRD reported removals as high as 96 percent for an initial
concentration of 0.39 mg/1 of arsenate and 82 percent for an initial
concentration of 0.12 mg/1 of arsenite. The study confirmed that:
- Arsenic V is more easily removed than Arsenic III by alum
and ferric sulfate coagulation.
349
-------
- Ferric sulfate is more effective for removal of Arsenic
III.
The average removal efficiency of Arsenic V was approximately 69
percent (minimum removal = 11 percent, maximum removal = 96 percent).
The average removal efficiency of Arsenic III was approximately 48
percent (minimum removal = 1 percent, maximum removal = 82 percent).
WSRD also investigated the use of lime softening techniques. Removals
of 71 percent for Arsenic III and 99 percent for Arsenic V were
reported after settling and dual-media filtration. The average
removal efficiency for Arsenic III was about 50 percent; and for
Arsenic V, about 76 percent.
In pilot plant studies in Taiwan, the only technique continuously
capable of high arsenic removal was ferric chloride coagulation,
preceded by chlorine oxidation (for oxidation of Arsenic III to
Arsenic V), followed by sedimentation and filtration (44). Based on
these studies, a full-scale arsenic removal plant for treatment of
municipal wastewater, handling 150 m3/day, was built in Taiwan.
During the first 59 days of operation, 82 to 100 percent removal was
achieved (with initial concentrations from 0.60 to 0.94 mg/1).
In a bench scale study conducted for EPA of priority heavy metals
removal, chemical precipitation was evaluated for arsenic removal from
three ash pond effluents (48). This treatment method proved effective
in reducing arsenic to the analytical detection limit. The results of
this study are presented in greater detail later in this section.
A summary of arsenic treatment methods and removals is shown in table
VII-15.
Nickel. Wastewaters containing nickel are found primarily in the
metal industries, particularly in plating operations. A list of
industries and their average wastewater nickel concentrations is given
in table VII-16. Nickel exists in wastewater as the soluble ion. In
the presence of complexing agents such as cyanide, nickel may exist in
a more soluble complexed form; therefore, pretreatment to remove these
agents may be necessary. The formation and precipitation of nickel
hydroxide is generally the basis for destructive treatment of nickel
wastes (as opposed to carbonates and sulfates, which are used in the
recovery of nickel). Table VII-17 summarizes actual full-scale
results of lime precipitation. The theoretical solubility limit for
nickel is approximately 0.001 mg/1 (46). Complete removal of nickel
has been reported with ion exchange treatments. Though this is
generally more expensive, the cost is offset by the value of the
recovered nickel. Since recovery of nickel from ash pond effluents is
not practical, such a treatment would probably be uneconomical for
steam electric powerplants.
Pilot plant studies (45) have been conducted on the use of reverse
osmosis for removal of nickel from wastewater. The studies indicate
removals of greater than 99 percent. It should be noted, however,
that reverse osmosis units typically blowdown 10 to 40 percent of the
350
-------
Table VII-15
ARSENIC REMOVAL FROM MUNICIPAL WASTEWATERS (44, 45)
Treatment Method
Lime Softening
Lime Softening
As V
As III
Coagulation with
Ferric Chloride
Coagulation with
Ferric Chloride
As V
As III
Chlorine Oxidation
and Ferric Chloride
Coagulation
Charcoal Filtration
Initial Arsenic
Concentration
(mg/1)
0.2
0.58
0.34
1.5-3.0
0.39
D.12
0.06-0.94
0.2
Final Arsenic
Concentration
(mg/1)
0.03
0.10
0.06
0.02
0.02
Percent
Removal
85
99
71
96-9.8
0.06
96
82
82-100
70
351
-------
Table VII-16
SUMMARY OF NICKEL CONCENTRATIONS IN METAL
PROCESSING AND PLATING WASTEWATERS (45)
Cmg/1)
Industry
TablewarePlating
Silver bearing waste
Acid Waste
Alkaline waste
Metal Finishing
Mixed wastes
Acid wastes
Alkaline wastes
Small parts fabrication
Combined degreasing, pickling and
Ni dipping of sheet steel
Business Machine Manufacture
Plating wastes
Pickling wastes
Plating Plants
4 different plants
Rinse waters
Large plants
5 different plants
Large plating plant
Automatic plating of Zinc base
castings
Automatic plating of ABS type
plastics
Manual barrel and rack
Nickel Concentration
Range Average
0-30 5
10-130 33
0.4-3.2 1.9
17-51
12-48
2-21
179-184 181
3-5
5-35 11
6-32 1.7
2-205
2-900
up to 200 25
5-58 24
88 (single
waste stream)
46 (combined
flow)
45-55
30-40
15-25
352
-------
Table VII-17
SUMMARY OF EFFLUENT NICKEL CONCENTRATIONS AFTER
PRECIPITATION THREATMENT (45)
CO
Ul
Source
Tableware Plating
Appliacne Manu-
facutring
Office Machine
Manufacturing
Non-Ferrous Metal
Plating
Record Changer
Manufacturing
Nickel Concentration (mg/1)
Initial Final
21
35
39
46
0.09-1.9
0.4
0.17
0.5-0.13
0.8
0.1-0.2
Precent Removal Comment
91-99.6
98.9
99.6
Sand Filtra-
tion
6 hour Works
settling
6 hour
detention in
clarifier
-------
volume of wastewater treated. Reverse osmosis simply concentrates
materials in a dilute stream.
Zinc. Waste concentrations of zinc range from 1 to 1,000 mg/1 in
various waste streams described in the literature, but average values
fall between 1 and 100 mg/1 as shown in table VII-18. Table VII-19
summarizes published precipitation treatment results. As with nickel,
cyanide forms a more soluble complex ion with zinc; therefore, cyanide
treatement may be required before precipitation of zinc.
A treatment combining hydroxide and sulfide precipitation of heavy
metals, known as the "Sulfex" process, has reported effective removal
of zinc, chromium, and other trace metals. The Sulfex process has
been used to treat water rinses following carburetor-casting treatment
tanks in an automotive plant in Paris, Tennessee. The waste stream in
this plant has a zinc concentration of 34 mg/1. Treatment has
resulted in a filtered effluent concentration of less than 0.05 mg/1
of zinc (47).
Copper. Primary sources of copper in industrial waste streams are
metal process pickling and plating baths. For a given bath, the rinse
water concentration will be a function of many factors, such as
drainage time over the bath, shape of the parts, surface area of the
parts, and the rate of rinse water flow. Untreated process waste
water concentrations of copper typical of plating and metal processing
operations are summarized in table VI1-20.
As with most heavy metal wastes, treatment processes for removal of
copper may be of a destructive nature, involving precipitation and
disposal of resulting solids, or of a recovery nature, e.g., ion
exchange, evaporation, and electrolysis. Ion exchange or activated
carbon are appropriate treatment methods for wastewaters containing
copper at concentrations less than 200. mg/1; precipitation is
applicable for copper levels of 1.0 to 1,000 mg/1, and electrolytic
recovery is advantageous for copper treatment at concentrations above
10,000 mg/1 (45).
Generally, hydroxide precipitation is accomplished by lime addition to
an acidic wastewater. The theoretical solubility limit of the metal
ion is approximately 0.0004 mg/1 at a pH of approximately 9.0 (46).
Theoretical levels are seldom achieved due to colloidal precipitates,
slow reaction rates, pH fluctuations, and the influence of other ions.
Reported treatment levels achieved by full-scale industrial treatment
operations are presented in table VII-21.
Selenium. Industries which use selenium include paint, pigment and
dye producers, electronics, glass manufacturers, and insecticide
industries. Selenium is similar to arsenic in several ways. For
example, the two predominant oxidation states in water are Selenium IV
(selenite) and Selenium VI (selenate) and selenium appears in the
anion form and thus has acid characteristics. Very little information
is available on levels of selenium in industrial wastewaters or
treatment methods for selenium wastes.
354
-------
Table V-18
CONCENTRATIONS OF ZINC IN PROCESS WASTEWATERS (45)
(mg/1)
Zinc Concentration
Industrial Process • Range ' Average
Metal Processing
Bright dip wastes 0.2-37.0
Bright mill wastes 40-1,463
Brass mill wastes 8-10
Pickle bath 4.3-41.4
Pickle bath 0.5-37
Pickle bath, 20-35
Aqua fortis and CN dip 10-15
Wire mill pickle 36-374
Plating
General 2.4-13.8 8.2
General 55-120
General 15-20 15
General 5-10
Zinc 20-30
.Zinc 70-150
Zinc 70-350
- Brass 11-55
•Brass 10-60
General 7.0-215 46.3
Plating on zinc castings 3-8
Galvanizing of cold rolled steel 2-88
S i1ver P1ating ]
Silver bearing wastes 0-25 9
Acid waste 5-220 65
Alkaline 0.5-5.1 2.2
Rayon Wastes .
General 250-1000
General . 20
General . 20-120
355
-------
Table VII-19
SUMMARY OF PRECIPITATION TREATMENT RESULTS FOR ZINC (45, 47)
Source
Zinc Plating
General Plating
General Plating
General Plating
Vulcanized Fiber
*-<•» Brass Wire Mill
Tableware Plant
Viscose Rayon
Viscose Rayon
Viscose Rayon
Metal Fabrication
Automotive Industry
(Sulfex Process)
Zinc (mR/1)
Percent Removal Comment
Initial
18.4
55-120
100-300
36-374
Final
0.2-0.5
2.0
0-6
<1.0
<1.0
0.08-1.60
89
99
99
99
Sand Fi
Integra
16.1
20-120
70
20
0.02-0.23
0.88-1.5
3-5
1.0
0.5-1.2
0.1-0.5
99
93-96
95
34
0.05
99
Treatment for
Copper Recovery
Sand Filtration
(1) Sedimentation
(2) Sand Filtration
-------
Table VII-20
COPPER CONCENTRATIONS IN WASTEWATER FROM METAL PLATING
AND PROCESSING OPERATIONS
(mg/1)
' Process
Plating Rinse
Plating Rinse
Plating Rinse
Plating Rinse
Plating
Plating
Plating
Plating
Plating
Plating
Appliance Manufacturing
Spent Acids
Alkaline Wastes
Automobile Heater Production
Silver Plating
Silver Bearing
Acid Wastes
Alkaline Wastes
Brass Plating
Pickling Bath Wastes
Bright Dip Wastes
Plating Wastes
Pickling Wastes
Brass Dip
Brass Mill Rinse
Brass Mill Rinse
Tube Mill
Rod and Wire Mill
Brass Mill Bichromate Pickle
Tube Mill
Rod and Wire Mill
Rolling Mill
Copper Rinse
Brass Mill Rinse
Copper Cone entrat ion
20-120
0-7.9
20 (ave.)
5.2-41
6,4-88
2.0-36.,0
20-30
10-15
3-8
11.4
0.6-11.0
0-1 .0
24-33 (28 ave.)
3-900 (12 ave.)
30-590 (135 ave.)
3.2-19 (6.1 ave.)
4.0-23
7.0-44
2.8-7.8 (4.5 ave.)
0.4-2.2 (1.0 ave.)
2-6
4.4-8.5
74
888
13.1
27.4
12.2
13-74
4.5
357
-------
Table VII-20 (Continued)
3 J ^ENTRATIONS IN WASTEWATER FROM METAL PLATING
AND PROCESSING OPERATIONS
(mg/1)
Process
IS lad • •
; S .. ,'1 ' •
js i id
>e: '. ill
>'3r Wire Mill
Mr Pickle
i-ar Bright Dip
*'oj >e: 'UD:- "".'.„•.' •• •!
€01 >e: r 'ir -1..~ -
Copper ure Extraction
Gold Ore Extraction
Acid Mine Drainage
Acid Mine Drainage
Acid Mine Drainage
Acid Mine Drainage
Copper Concentration
72-124
60-9
20-35
19-74
70 (ave.)
800 (ave.)
0.28-0.33
20
3.2
3.9
0.12
51.6-128.0
358
-------
Table VII-21
COPPER REMOVAL BY FULL-SCALE INDUSTRIAL WASTEWATER
TREATMENT SYSTEMS (45)
Ul
(a
Source and Treatment
Metal Processing (Lime)
Nonferrous Metal Processing
(Lime)
Metal Processing (Lime)
Electroplating (caustic,
Soda Ash t Hydrazine)
Machine Plating (Lime +
coagulant)
Metal Finishing (Lime)
Brass Mill (Lime)
Plating
Plating (CN oxidation, Cr
reduction, neutralization)
Wood Preserving (Lime)
Brass Mill (Hydrazine + NaOH)
Silver Plating (CN oxidation,
Lime, Fe Cl3
Initial
Copper eonc,
(mg/1)
204-385
6.0-15.5
10-20
11.4
0.25-1.1 (range)
75-124
30 (ave.)
Final Copper cone.
(mg/1)
0.5
0.2-2.3 (prior to
sand filtration)
1.4-7.8 (prior to
sand filtration)
0.0-0.5 (after sand
filtration)
0.09-0.25 (sol.)
0.30-0.45 (tot.)
2.2
0-12 (ave. 0.19)
1-2
0.02-0.2
2.0 ,
« i
0.1-0.35
0.25-0.85
0.16-0.3 (with sand
filtration)
Removal
Efficiency
98.7-99.8
f '
99-99.5
-------
Secondary municipal sewage treatment plants with 2 to 9 ug/1 of
selenium in the effluent have been reported (45). A tertiary sequence
of treatment which included lime treatment to pH 11, sedimentation,
mixed-media filtration, activated carbon adsorption and chlorination
yielded selenium removals of 0 to 89 percent. In another study (45),
various advanced treatments were tested for a sewage treatment plant
effluent with a selenium concentration of 2.3 ug/1. The investigators
concluded that efficient removal (99 percent) could be achieved using
a strong acid-weak base ion exchange system (45).
Jar tests and pilot plant tests conducted by WSRD on the removal of
selenium from ground and surface waters by conventional coagulation
showed that selenium removal is dependent on the oxidation state,
initial concentration of selenium, pH, and types and doses of
coagulation (44). Removals range from 0 to 81 percent using ferric
sulfate and alum coagulants. In general, ferric sulfate was more
efficient than alum in removing Selenium IV. Both ferric sulfate and
alum yielded removals of 11 percent or less for Selenium VI. Initial
selenium concentrations ranged from 0.03 to 0.10 mg/1. With dual
media and granular activated carbon filters, removals as high as 80
percent were obtained for Selenium IV. WRDS also conducted pilot
plant studies on lime-softening treatments for selenium removal. The
results indicate that this is not an effective treatment for selenium
removal (44). WSRD conducted studies which confirmed removals of
greater than 99 percent using a cation-anion exchange system in
series. Research on both laboratory and pilot plant scale is needed
before feasibility of this treatment technique can be determined (44).
Ash Pond Overflows. The removal efficiencies which have been
presented for arsenic, nickel, ziric, selenium and copper must be
viewed with caution regarding application of removal efficiencies to
fly ash and bottom ash pond discharges. Table VI1-22 shows a
comparison of the range of initial concentrations associated with the
removal efficiencies which have been presented and the average
concentrations of trace metals in fly ash and bottom ash pond
discharges. The average concentrations in fly ash and bottom ash
ponds are much lower than the ranges of initial concentrations
contained in the literature; thus, the removal efficiencies do not
necessarily reflect the efficiencies of such treatments for removal of
•trace metals in the ash ponds of steam electric powerplants. The
final effluent concentration, however, would probably be lower for a
powerplant because of the low initial concentration.
i
Bench scale studies of various removal technologies for treatment of
ash pond effluents from steam electric powerplants have been conducted
(48). Results of chemical precipitation treatments of the ; ash pond
effluents from three powerplants located in Wyoming, Florida, and
Upper Appalachia are shown in tables VI1-23 and VI1-24 for lime and
lime and ferric sulfate addition, respectively. Arsenic removal
appears to be reasonably good, ranging from 67 to less than 99
percent. Copper removals are variable, ranging from 31:to 80 percent.
The efficiency of nickel removal is also uncertain. Selenium removal
is, in general, fairly poor. This is consistent with other studies
360
-------
Table VII-22
COMPARISON OF INITIAL TRACE, METAL CONCENTRATIONS CITED
IN STUDIES REPORTED IN THE LITERATURE AND TRACE METAL
CONCENTRATIONS IN ASH POND DISCHARGES
(ppm)
Metal
As
Ni
Zn
Cu
Se
Initial
Concentrations
Treated
0.200 to 3.00
18 to 374
0.25 to 385
0.01 to 0.08
Average
; Bottom Ash
Coneentration s
0.022
0.079
,0.020
0.012
0.004
Average
Fly Ash
Concentrations
0.055
0.224
0.014
0.003
0.008
361
-------
Table VII-23
TRACE METAL REMOVAL EFFICIENCIES FOR LIME PRECIPITATION
TREATMENT OF ASH POND EFFLUENTS (48)
Arsenic
Wyoming
Florida
Appalachia
Copper
Wyoming
Florida
Appalachia
Nickel
Wyoming
Florida
Appalachia
Selenium
Wyoming
Florida
Appalachia
Zinc
Wyoming
Florida
Appalachia
Inlet
(ppb)
9
74
80
14
26
9.5
5.5
2.5
3
8
42
300
7
11
Outlet
23
10
12
0.5
6.0
2.2
3
8
52
31
2
<2
Removal Efficiency
DL
89
>99
71
29
54
<95
OGTI
12
DL
. NR
OGTI
90
57
>82
KEY: DL - Concentrations of both inlet and outlet are below
the detection limit.
OGTI - Outlet concentrations greater than inlet.
NR - No removal.
362,
-------
Table VII-24
TRACE METAL REMOVAL EFFICIENCIES FOR LIME PLUS
FERRIC SULFATE PRECIPITATION TREATMENT OF ASH POND
EFFLUENTS (48)
Inlet
(ppb)
Outlet
(ppb)
Arsenic
Wyoming
Florida
Appalachia
Copper
Wyoming
• Florida
Appalachia
Nickel
Wyoming
Florida
Appalachia
Selenium
Wyoming
Florida
Appalachia
Zinc
Wyoming
Florida
Appalachia
80
14
26
9.5
5.5
2.5
3
8
42
300
7
11
23
7
18
10.5
9.0
2.0
3
7
32
25
6
<2
Removal Efficiency
DL
67
>99
80
50
31
>95
OGTI
20
DL
12
24
92
14
>82
KEY: DL - Concentrations of both inlet and outlet are below
the detection limit.
OGTI - Outlet concentrations greater than inlet.
NR - No removal.
363
-------
cited earlier on removal of selenium by chemical precipitation. The
efficiency of zinc removal varies significantly from 14 to 92 percent.
Though this study may indicate that1 chemical precipitation has
potential for effective removal of some trace metals from ash ponds
effluents/ other studies are necessary to confirm these results.
Ash/Sludge Disposal. The two primary methods of ash disposal are
landfill and utilization. Only a few plants presently sell or use fly
ash. Ash which has been collected dry or has been dewatered is
disposed of by landfill. Figure VII-39 illustrates some common
landfill methods. Equipment requirements include closed trucks,
graders, and bulldozers. Disposal of dry fly ash poses some fugitive
dust problems. Closed trucks are used to prevent fugitive dust
emissions enroute to the landfill site. At the site, the ash should
be wetted down after application to the landfill.
Bottom Ash
The technologies applicable to bottom ash handling systems are:
1. dry bottom ash handling,
1. Hydrobin/dewatering bin systems, and
3. ponding with recycle.
Dry Systems
Dry handling of bottom ash is generally typical of stoker-fired
boilers. This method is used by 19 percent of those plants which
reported a bottom ash system type in the 308 survey (including all
types of plants). Stoker-fired boilers are generally used in
relatively small capacity installations where small amounts of bottom
ash are handled. Since this technology represents a small and more
obsolete sector of the industry, it is not addressed in further detail
in this section.
Complete Recycle Systems
The term "complete recycle" describes a system which returns all of
the ash sluice water to the ash collecting hoppers for recurrent use
in sluicing. The key concept of complete recycle is that there is no
continuous discharge of sluice water from the system. Virtually no
system is zero discharge from the standpoint of containing all ash
handling water onsite because ash-laden water does leave the facility
in a variety of ways. Water is occluded with the ash when trucked
away to disposal. Under upset conditions, it is often necessary to
discharge water. In some cases, small amounts of water from the ash
handling system are needed elsewhere in the plant, typically for
wetting fly ash handling trucks to prevent blowing of dry fly ash and
for servicing the silo unloaders. Makeup water is required to
maintain a steady water balance despite these inherent losses in the
364
-------
Sidm Hill Landfill
Ucdfill
Caofiguracioa
FU1
DiapasaL
Configuracion
Figure VII-39
LANDFILL METHODS
365
-------
system. The magnitude of the makeup water requirement depends upon
the major equipment in the ash handling system.
Technology Descriptions.
Dewatering/Hydrobin System (36). The various stages of a closed-loop
recirculating system appear in figure VII-40. For the sake of
clarity, some details have been omitted. Initially, as illustrated in
figure VII-40a, the ash hopper is filled to its overflow line, and one
dewatering bin (bin A) is partially filled with water. Enough water,
remains in the storage tank to start operating the system after the
ash hopper is filled with ashes. In the next stage, illustrated in
figure VII-40b, the ash hopper has been filled with ashes, and the
water displaced by them has been pumped into the settling tank and
overflowed into the storage tank. In the next step, shown in figure
VII-40c, ash hopper cleaning is in progress in the right hand chamber.
Ashes are pumped to the Dewatering B.in A. As ash-water slurry enters
the dewatering bin, an equal amount of water overflows to the settling
tank and then to the storage tank. In figure VII-40d, the ash hopper
has been completely emptied. All of the water that had been in the
ash hopper is now in the storage tank. The water in the storage tank
is used to refill the ash hopper as shown in figure VII-4Qf. The
water in the ash hopper is then available for filling Dewatering Bin B
as shown in figure VII-40g. The water volume in the settling tank
remains constant while the volume in all other vessels varies during
different phases of operation.
Outside makeup water is necessary to restore the water lost with the
bottom ash discharged from the dewatering bins as well as water lost
through evaporation from the bottom ash hopper. Makeup usually is
added at the storage tank. An emergency bypass can be installed
between the settling tank and the storage tank to provide needed water
in the event of temporary failure of outside makeup.
In most cases, a closed-loop recirculating system shows a marked
change in the pH of the recirculated water. This ph shift is tempered
by the addition of makeup water if it is- added in sufficient quantity
and is of good quality. A monitoring system and chemical additives
can maintain recirculated water at as neutral a level as possible in
order to keep pipe scaling or corrosion to a minimum.
Cases where pH adjustment is not sufficient for scale prevention, such
as very reactive bottom ash or poor intake water quality, may require
side stream lime/soda ash treatment. The equipment for ' slip stream
softening has been described in the section concerning
physical/chemical treatment of ash pond overflows from wet once-
through fly ash handling systems. The magnitude of the flow rate of
the slip stream is estimated to be about 10 percent of the total
sluice stream. The use of slip stream softening in a dewatering bin
system would create an additional solid waste stream as well as an
additional water loss source which would require more makeup water.
Slip stream softening in a dewatering/hydrobin system is not a proven
technology based on data from the 308 survey.
366
-------
DEWATERIN6 BINS
OVERFLOW SIN
OVERFLOW PUMP
I STORAGE TANK
RETURN WATER PUMP
OEWATCRINO
BINS
SYSTEM FILLED WITH WATER.
TO RECEIVE ASH
PEWATENING BINS
KTLOW BW
PUMP
STORAGE TANK
OEWATERINO
NCTUKN WATS* PUMP
HOPPCT FILLED WITH ASH. WATCT DISPLACED
TO STORAGE TANK THRU OVERFLOW SIN AND
SCTTLtNC TANK.
Figure VII-40
VARIOUS STAGES OF A CLOSED-LOOP RECIRCULATING SYSTEM (36)
367
-------
OEWATERIW; ems
OVERFLOW BIN
OVERFLOW PUMP
/ STORAGE TANK
0 OEWATEHIMS
BINS
RETURN WATER PUMP
ASH HOPPEft BEIM6 EMPTIED. OCWATERINO
flIN BEING FIU.CB. OVERFLOW TO SCTTUNG
TANK.
OEWATEIHN6 BINS
OVERFLOW BIN
RFLOW PUMP
STORAGE TANK
RETURN «MTER PUMP
0 OEWATCRINO
BINS
ASH HOPPER EMPTIED, OEWAfEltlMO SIN PIU.EO.
Figure VII- 40 (Continued)
VARIOUS STAGES OF A CLOSED-LOOP RECIRCULATING SYSTEM (36)
368
-------
OEWATERIM4 BINS
LOW BIN
OVERFLOW PUMP
/ STORAGE TAMIC
RETURN WATER PUMP
0 OeW&TCRINO
BINS
ASH HOPPER REFILLED WITH WATER.
OEWATEHIHC BINS
VERFLOW BIN
OVERFLOW PUMP
/ STORAfie 'TANK
TO DEWATCHINO
BINS
RETURN WATER PUMP
OEWATERING BIN BEING DRAINED.
Figure VII- 40 (Continued)
VARIOUS STAGES OF A CLOSED-LOOP RECIRCULATING SYSTEM (36;
369
-------
OEWATeitlNS BINS
.OVERFLOW SIN
rFLOW PUMP
STORAGE TANK
RETURN WATER PUMP
DEWATEMINO
BINS
DEWATERING BIN ® UNLOAOINO. DEWATERIN8 «IN ®
BEING fVKRTIAU.7 FIUXD WITH WATER.
Figure VII- 40 (Continued)
VARIOUS STAGES OF A CLOSED-LOOP RECIRCULATING SYSTEM. (36)
370
-------
Bottom ash obtained from dewatering bins is considered "commercially
dry" by vendors of this equipment (36, 39), i.e., on the order of 20
percent moisture. This degree of moisture can vary widely depending
on the installation as well as within a particular plant. The ash is
wet enough for transport to a landfill site in an open truck without
creating a fugitive dust problem, and at the landfill site, there is
no need to wet the ash down. Some dust problems may occur with
certain western coal ashes since these tend to contain relatively more
fines than eastern coal ashes (39).
A dewatering/hydrobin system which contains a slip stream softening
system produces a sludge waste stream which requires disposal. This
waste is produced at a much lower rate than is the bottom ash and has
a higher moisture content.
Ponding System. Approximately 81 percent of all plants which replied
in the 308 survey designated ponding as their bottom ash handling
method. Of these, approximately 9 percent designated either complete
or partial recycle.
A ponding recycle system for(bottom ash is illustrated in figure VII-
41. The ash or slag collected in the bottom ash hopper which is
filled with water is ground down to a sluiceable size range by clinker
grinders at the bottom of the hopper. Depending on the size of the
boiler, the bottom ash hopper may have two or three "pantlegs," or
discharge points. At each pantl-eg there may be one or two clinker
grinders. Larger facilities usually have three pantlegs and two
clinker grinders at each pantleg (39). Smaller facilities have two
pantlegs and one clinker grinder at each leg. Double roll clinker
grinders can generally handle from 75 to 150 tons per hour of ash with
drives from 5 hp to 25 hp depending on the material to be crushed and
required system capacity. A smaller grinder that can handle 20 tons
per hour or less uses a single roll with a stationary breaker plate.
After being crushed, the ash is fed into an adopter or sump from which
it is pumped by one of two types of pumping devices, a centrifugal
pump or a jet pump. Pumps and piping have already been discussed in
the subsection on partial recirculating fly ash systems.
A series of ponds are usually used for bottom ash settling. A primary
pond accumulates most of the sluiced bottom ash. The sluice water
then flows by gravity to a secondary settling pond. Overflow from the
secondary pond goes to a final or clear pond which is used as a
holding basin for the recirculating water. Pond sizes cover a wide
range depending on the plant size, the amount of bottom ash produced
(boiler type), pond depth, required holding time (which is a function
of the solids settling rate), and the amount of land available.
Typically, the primary and secondary ponds are dual systems so that
dredging does not interfere with operation. For instance, a plant may
have two primary and secondary ponds. One primary and one secondary
are dredged annually to remove the settled solids while the other two
ponds are in operation.
371
-------
CO
N>
f_ _s
V" ~
(Discharge
for
Partial
Recycle)
/
Makeup
Water
>
Alternate Alternate
Secondary Primary
Settling Settling
Pond Pond
_ | | j 1 |
Recycle Pumps — i i i i —
. \l V/ \\ */
\ — ''1T\'< / > S
}~\ ^\ ,(. Secondary Settling Primary Settling
V. / PnnH Pond
Clear Pond
Bottom Ash Hopper
\. /^ClinkerV /
\-VxV Grinders 7-V*V _«. -. • 1
' (JO UU s/*s *
Ash Sluice Pumps
Figure VII-41
PONDING RECYCLE SYSTEM FOR BOTTOM ASH
-------
Facilities may be made available to provide for a discharge of sluice
water.from' the recycle line. A makeup water stream will be necessary
due to water losses inherent in the system. The most significant
water losses occur in percolation through the floor of unlined ponds
and evaporation of pond water. A pond, system maintained at a steady-
state water balance without discharging is considered a zero discharge
or complete recycle system. A partial recycle system maintains a
discharge either on a continuous basis or for upset conditions.
Bottom ash recovered from ponds by dredging does not create fugitive
dust problems because of the .high moisture content of the ash.
Disposal of bottom ash may be achieved by any of the conventional
landfill methods discussed in the fly ash subsection.
Evaporation Ponds. In cases, where pH adjustment can not adequately
prevent scale, an alternative to slip stream softening is the release
of some of the ash sluice water as a blowdown stream. In cases where
it is difficult to maintain a steady water balance in a complete
recycle system, occasional discharge of ash sluice water may be
necessary. The use of evaporation ponds to contain blowdown streams
from dewatering bin systems is an option for achieving zero discharge
under these conditions. This option has been successfully exercised
in the western part of the United States where high net evaporation
rates are indigenous. Two of the plants visited attained zero
discharge by using a blowdown to evaporation ponds from dewatering bin
systems.
Retrofitting. The primary reasons for retrofitting complete recycle
systems are:
1. A shortage of water requiring minimal consumption,
2. State or local regulations governing, a reduction in
wastewater pollutants, and
3. A market for dewatered slag.
Some of the piping from the old system is reusable in the retrofitted
system, although difficulties may be encountered in rerouting old
pipe. Of course, difficulty may be encountered in integrating any
other system discharge with the bottom ash recycle loop, e.g., sump
discharge and cooling tower blowdown. Plant downtime would be
required for the hook-up of the retrofitted dewatering bin system,
resulting in a temporary reduction in generating capacity.. In
addition, some downtime may occur during the debugging period. For
some plants, debugging may last up to a year. The land required to
retrofit a dewatering bin system is:
- Approximately 1 acre to contain the dewatering bins,
settling tank, surge tank, and pump houses; and
- Landfill area for bottom ash disposal.
373
-------
A plant that used a pond system prior to the retrofit of the
dewatering bin system probably would have land available for disposal
of the dewatered bottom ash.
Utilization of Complete Recycle Systems. Data from the- 308 survey
provided a list of plants which reported wet recirculating bottom ash
handling systems and zero discharge of ash transport water. EPA
teleponed each of these 14 plants to confirm the data submitted on the
1976 data form. The results of the telephone contacts appear in table
VII-25. Specific details of plant designs are discussed below.
This information has not been positively confirmed for all 14 plants.
The only method of positive confirmation is site inspection but time
and budget constraints precluded visitation of all 14 plants. Four of
the plants were visited.
Plants 4813, 3203, 1811 and 0822, handle and dispose of bottom ash
completely separately from fly ash. The plants employ dry fly ash
handling and complete recirculation of bottom ash transport water.
The plants are located in Texas, 'Indiana, Nevada, and Colorado. The
facilities in Nevada and Colorado make use of high evaporation rates
in those locations to achieve zero discharge while allowing for some
blowdown from the systems. The fuels burned at these plants include
lignite and bituminous coals with the ash contents ranging from 9.7
percent to 11.5 percent. The boiler types include both pulverized
coal boilers and cyclone boilers, giving a bottom ash to fly ash ratio
from 20:80 to 90:10. These plants represent zero discharge designs;
while the absolute number of plants identified as achieving zero
discharge from this study is small, they do present a representative
mix of location fuel type and boiler type.
Plants 4813, 3203, and 0822 use hydrobines or dewatering bins to
separate the bottom ash particles from the sluice water. In each
case, the sluice water overflows the weir at the top of the bin and
gravity flows to a surge tank which supplies the suction side of the
recycle or recirculation pumps. Makeup water to compensate for
evaporation, water lost from pump seals, water lost from the ash
hopper locks, water occluded with the bottom ash and other spills and
leaks is added at some point in each system depending on the plant.
Accurate control of makeup water is an important factor in achieving
zero discharge. If the actual makeup rate exceeds the required makeup
rate, a system upset occurs which causes discharge of ash transport
water. Such upsets do occur in most systems from time to time, but do
not constitute normal operating procedure. Plant 4813 has settling
ponds backing up the hydrobins. Bottom ash can be sent to either
system. One pond serves as a recycle tank from which recirculating
sluice water is drawn.
Plant 1811 uses a ponding system to separate the bottom ash from the
sluice water. Once side of the settling pond is wide and gradually
inclined. The ash is sluiced to this open area where the heavy
material forms a pile. The sluice water drains into a final settling
374
-------
Table VII-25
DATA SUMMARY OF PLANTS REPORTING ZERO DISCHARGE OF
BOTTOM ASH TRANSPORT WATER
Plant
Code Location
2903 Missouri
2705 Minnesota
Ul
2413 Maryland
4813 Texas
Fuel
Bituminous
(13.8% ash)
Subbituminous
(9% ash)
Bituminous
(14.6% ash)
Lignite
(10.4% ash)
Boiler Type Ash Handling Systems
Pulverized-
Dry Bottom
Pulverized-
Dry Bottom
Pulverized-
Dry Bottom
Pulverized-
Dry Bottom
Fly Ash can be either
dry transported to
silo (for sale) or
or sluiced to pond
Bottom Ash is sluiced
to pond and water is
recycled
Fly Ash removed in
wet scrubber
Bottom Ash is sluiced
to pond and some
of sluice water is
recycled
Dry Fly ash handling
Bottom ash sluiced to
hydrobins overflow to
surge tank and
recycled
Dry Fly ash handling
Bottom ash sluiced
either to hydrobins or
primary settling ponds
all sluice water is
recycled
Comments
Not all sluice
water is recy-
cycled some is
discharged to
a river
The Bottom Ash
Sluice water
not recycled
serves as
scrubber makeup
Not all the
sluice water is
recycled some
reaches, central
treatment plant
Zero discharge
of bottom ash
sluice water
-------
Table VII-25 (Continued)
DATA SUIMARY OF PLANTS REPORTING ZERO DISCHARGE OF
BOTTOM ASH TRANSPORT WATER
Plant
Code Location
5102 Virginia
Fuel
u>
4230 Pennsylvania Bituminous
(10% ash)
Boiler Type Ash Handling Systems
Bituminous Pulverized-
(17.8% ash) Dry Bottom
4229 Pennsylvania Bituminous Pulverized-
(11.5% ash) Dry Bottom
Pulverized-
Dry Bottom
2901 Missouri
Subbituminous Pulverized-
(25% ash) Wet Bottom
Dry Fly ash handling
Bottom ash is sluiced
to a pond and all pond
water is recycled
Dry Fly ash handling
Bottom ash is sluiced
to a pond some of the
water is recycled
Wet Fly ash handling
with recirculation of
water
Bottom ash sluiced to
a pond, some of the
water is recylced
Fly ash is sluiced to
settling pond water is
recycled
Bottom ash is sluiced
to settling pond and
water is recycled
Comments
Drains carrying
discharges from
ash hoppers and
pumps go to
central treat
ment facility
and are
discharged
Not a zero dis-
charge facility
Not a zero dis-
charge system
facility, ash
transport water
goes to treat-
ment facility
Combined ash
pond, all water
is recycled-
zero discharge
of ash trans-
port water
-------
Table VII-25 (Continued)
DATA SUMMARY OF PLANTS REPORTING ZERO DISCHARGE OF
BOTTOM ASH TRANSPORT WATER
Plant
Code Location
3203 Nevada
1811
Indiana
1809 Indiana
3626 New York
Fuel
Bituminous
(9.69% ahs)
Bituminous
(11.54% ash)
Bituminous
(13.721 ash)
Bituminous
(17.7% ash)
Boiler Type Ash Handling Systems
Pulverized-
Dry Bottom
Cyclone-
Wet Bottom
Cy clone-
Wet Bottom
Pulverized-
Dry Bottom
Dry Fly ash handling
Bottom ash is sluiced
to dewatering bins and
water is recycled
- Dry Fly ash handling
- Bottom ash is sluiced
to a pond, water is
recycled recycled
Fly ash is wet sluiced
to ponds overflow goes
to recycle
Bottom ash is wet
sluiced to holding
pond overflow to
recycle
Dry Fly ash handling
Bottom ash wet sluiced
to hydrobins, overflow
to surge tank and
recycled
Comments
Slowdown from
bottom ash
sluicing system
goes to evap.
ponds
Zero discharge
design however
blowdown is
removed at times
when water
balance problems
occur
Recycle serves
both fly ash and
bottom ash
sluicing opera-
tions, zero dis-
charges except
under upset
conditions
Some water is
discharged due
to water balance
problems
-------
Table VII-25 (Continued)
DATA SUMMARY OF PLANTS REPORTING ZERO DISCHARGE OF
BOTTOM ASH TRANSPORT WATER
Plant
Code Location
2415 Maryland
0822 Colorado
Fuel
Bituminous
(14.58% ash)
Bituminous
(10.661 ash)
Boiler Type Ash Handling Systems
Pulverized-
Dry Bottom
Pulverized-
Dry Bottom
oo
Dry Fly ash handling
Bottom ash wet sluiced
some of water is
recycled
Dry Fly ash handling
Bottom ash is wet
sluiced to hydrobins
and overflow goes to
recycle basin
Comments
Not a zero dis-
charge plant,
sluiced water is
treated prior to
discharge
Slowdown from
sluice system is
sent to evapora-
tion pond
-------
pond at the base of the incline. The recircul at ion pumps dtav> suction
from this pond. All system drains and leaks are sent to this pond.
Plants 2901 and 1809 sluice both fly ash and bottom ash. These two
sluice waters' are ponded prior to recycle. In both cases, the primary
settling ponds for fly ash and bottom ash are separate ponds. The
overflow from these ponds gravity flows to a final settling pond.
Both plants are zero discharge designs. Only under upset conditions
is ash handling water discharged. The plants are located in Missouri
and Indiana and burn a subbituminous coal with 25 percent ash and a
bituminous coal with 13.7 percent ash. Both plants have cyclone
boilers which give a bottom ash to fly ash ratio of 90:10.
The remaining plants employ some continuous blowdown or discharge from
the recirculating bottom ash sluicing systems. These plants have very
low discharge rates but are not zero discharge facilities. Only one
plant, 4429, was designed to be zero discharge but was unable to close
the water balance due to problems in accurately monitoring the makeup
water requirement. An additional plant, 2750, was not intended to be
a closed-loop bottom ash system since the scrubber makeup is drawn
from the recycle tank. If the scrubber loop can be operated in a
closed-loop or zero discharge mode, this plant could be considered a
zero discharge facility from the standpoint of ash handling. It could
not, however, be representative of achievable complete recycle
technology for bottom ash handling.
Each plant contact was asked if any scaling or corrosion problems had
resulted from the recirculation mode of operations. . Only one plant,
2750, indicated that scaling in the recirculation .line might, be a
problem. No such problems have been encountered however. The plants
in the survey produce both alkaline ash and acid ash covering the
range of. chemical properties of ash .handling waters,
Trlg.:Jgejggrts.' Four plants were visited' to confirm the bottom ash
handling practices as. zero discharge. Only two of the four plants
were true zero discharge plants: 3203 and 0822. In both cases a
blowdown from the bottom ash sluicing systems (with dewatering. bins)
was observed? however, this blowdown was directed to evaporation ponds
on plant property. The purpose of the blowdown was primarily to
maintain a steady-state water balance. The remaining two plants, 1811
and 1809, were confirmed as having discharges and were considered
partial recycle plants.
Abridged versions of the trip reports for these plants are contained
in this subsection. A,description of the bottom ash handling system,
a discussion of retrofitting problems, a discussion of operating and
maintenance problems, and a .presentation of sampling and analysis work
are provided for each plant.
Plant 3203. This plant is a 340-MW western bituminous coal- burning
facility that uses a dewatering bin (United Conveyor Corporation)
bottom ash sluice recycle system with a series of evaporation ponds.
The plant fires a moderately low-sulfur coal (average 0.6 percent)
379
-------
with an average ash content of 12 percent and fluctuation to
approximately 16 percent ash. The availability of the three boilers
has historically averaged 86 percent annually. Water comes from two
sources. During the summer, water is pumped from wells and during the
winter, from a nearby river. The water is pumped to a reservoir for
holding and then to the three cooling towers. Slowdown from the
cooling towers accumulates in a storage tank. Water from this storage
tank then feeds the three S02 scrubbers as well as the bottom ash
sluicing system. The bottom ash storage tank receives water from the
cooling tower blowdown storage tank and from the plant drain sump; the
drain sump receives water from the area drains and boiler blowdown. A
generalized flow diagram appears in figure VII-42, which shows the
major equipment and associated typical flow rates.
The bottom ash sluicing system was designed and installed by United
Conveyor Corporation. It was retrofitted to Units 1 and 2 and was
installed along with Unit 3. The system was designed for 7 percent
ash coal with capacity to handle a fourth unit, which was to be built
at a later date. The bottom ash handling system is currently
operating at a greater-than-rated capacity due to the higher-than-
average ash coal being burned in the three units.
The general flow scheme for this bottom ash recycle system is shown in
figure VI1-43. The bottom ash handling system processes approximately
77 tons per day of bottom ash as well as 1 ton per day of economizer
ash for all three units combined. The bottom ash is pumped from the
hoppers to the dewatering bins for approximately 4 hours per day, the
economizer ash for 1 hour each day. It takes approximately 6 hours to
dewater the bottom,ash in the bin to yield an ash moisture content of
about 20 percent to 50 percent. Approximately, one truckload of
dewatered bottom ash is hauled to the onsite disposal area per day.
The number of loads per month varies from 30 to 40. The disposal area
is 1 mile from the plant. The hauling and placement of the ash is
contracted to an outside firm.
The major equipment for the bottom ash recycle system was bought,from
and installed by United Conveyor Corporation. The dewatering bins are
30 feet in diameter, with 5,000 cubic feet per bin. Two bins are
used* one dewaters ash, while the other fills with ash. The drained-
off water from the bins flows by gravity to a settling tank of 50 feet
in diameter and a capacity of 145,000 gallons. Sludge pumps are
provided beneath the settling tank to pump any settled solids back
into the top of the settling tank. Overflow from the settling tank
drains into the surge (or storage) tank, which is of the same diameter
and capacity as the settling tank. The surge tank is operated,
however, at 19,108 cubic feet, or 135,000 gallons. Sludge pumps
beneath the surge tank pump any settled solids back into the settling
tank. From the surge tank, water is pumped back to the bottom ash
hoppers for subsequent sluicing. A jet pump provides the pressure for
transporting the ash to the dewatering bins. The length of pipe from
the bottom ash hopper to the dewatering bin is approximately 500 feet
for Unit 3 and,100 feet from Units 1 and 2. The pipe diameter for
this system is typically 10 inches with a discharge pressure of 200
380
-------
Te Scrubber
Settling tad
fTOB Sh«
mils atsd river
(1 con per day of ash)
9>"To Dose Conditioners
Bonea Aah & Seaoaoixar
To Bvmporacion Pond*
50-100 gpn
Figure VII-42
WATER FLOW DIAGRAM FOR PLANT 3203
381
-------
LO
00
To Fjly Ash
Conditioner"
To Evapora-
tion FOB
Froa Cooling Tower
Slowdown Storage Tank
From Jlant
Drain Sump
«Sample |2
Settling Tank
Overflow
Recycle
Water \Storage
Slu dee
fro
Sludge Settlln
Pun»P Tank
Storage
Tank
Units
1,2,3
Dewatered
Bottom Ash
to Disposal
Sludge to
Bump
Economizer
—i
I I Ash Hopper
V
Bottom Ash Sluice Water
(1,250,000 gpd)
Overflown to
Plant Drain Sump
Sample Location
Figure VII-43
BOTTOM ASH RECYCLE SYSTEM AT PLANT 3203
-------
psi. The land area devoted to the dewatering bins, settling tank, and
surge tank is approximately one acre; this does not include the pump
house or pipe.rack. The bottom ash is trucked to a 200-acre, onsite
landfill area. Side streams are taken from the bottom ash sluice
lines which feed the fly ash dust conditioning nozzles and from a
purge stream to the evaporator ponds. The purge flow rate is
continuous and varies from approximately 50 to 100 gpm.
The maintenance of the sluicing system has been nominal since
installation in 1975. No chemical testing for scaling species has
been done and no scaling has been observed to the extent of producing
a malfunction in equipment or line pluggage. Some minor corrosion on
valves has occurred and some pump repair has been needed due to minor
erosion.
There is a problem with solids plugging the bottom of the settling
tank. This is due to several inherent design aspects of the system.
The settling tank is not designed to remove large amounts of sludge.
In this system, the plant drain sump discharges to the settling tank
as well as the sludge from the surge tank. Adding to the problem is
the fact that the system was designed to remove less ash than is
currently being generated. : Generation of fines is indigenous to
western bituminous coal ash. These fines can plug the dewatering bin
screens and overflow into the settling tank. A platform has been
built over the settling tank to provide access for air lancing the
solids in order to prevent sludge pump plugging. The settling tank
sludge pumping capacity is to be doubled in the future to help reduce
the load on the current pumps.
The entire bottom ash system requires two men per day for maintenance
and one man per shift each day for operation of the system.
The motivation for retrofitting the bottom ash recycle system was a
general water shortage problem associated with both wet once- through
bottom ash and fly ash handling systems. At the time the bottom ash
recycle system was installed, a pressure dry fly ash handling system
and a third unit were also installed. Scaling .problems tended to be
more prevalent in the wet once-through system than in the current
bottom ash sluice recycle system. Some of the wet once-through system
piping was reused in the installation, of the new bottom ash system. A
2-week outage for Units 1 and 2 occurred when the retrofit systems
were installed and major pipe rerouting was done. It took
approximately a year to debug the fly ash and bottom ash systems as
well as the new Unit 3. ' .
Samples were taken ,at three different locations in the bottom ash
sluicing system. These locations are shown in the bottom ash sluicing
system diagram in figure VII-43 and are described as follows:
1. A sample was taken of a stream of water leaking through the slide
gate at the bottom of the dewatering bins,
383
-------
2. A sample was taken of the recycle system makeup water from the
cooling tower blowdown tank, and
3. A sample was taken at the recirculation pump which pumps the ash
transport water back to the bottom ash hoppers.
These samples provide an indication of the trace elements, major
species, and carbon dioxide content of transport streams before and
after dewatering of the bottom ash and of the makeup water to the
system. The trace elements which were quantified include silver,
arsenic, beryllium, cadmium, chromium, copper, mercury, nickel, lead,
antimony, selenium, thallium, and zinc. Other metal elements (major
species) were magnesium, calcium, and sodium. The non-metal major
species quantified were phosphate, sulfate, chloride, silicate, and
carbon dioxide. The results of the analyses are presented in tables
VII-26 and VII-27.
Of the three samples taken, the cooling tower blowdown had the highest
concentrations in arsenic, magnesium, sulfates, and silicates. The pH
of this stream was 8.2, and the temperature was 96 F. Dilution of
this stream in the surge tank with the plant drain sump effluent
resulted in lower concentrations of these species. Species which had
the highest concentrations at the recirculation pump, i.e., downstream
from the surge tank, were phosphates, chlorides, carbon dioxide, zinc,
and sodium. The pH of this stream was 8.2, and the temperature was 126
F. The third sample was taken from a leak beneath the dewatering bin
during an ash dewatering mode of operation. The pH of this water was
10.4, and the temperature was ambient, 106 F. The significant species
in this sample relative to the other two samples were copper, lead,
and calcium.
On the basis of the sampling results and the subsequent analyses, EPA
assessed the potential for precipitation of certain species by using
an aqueous equilibrium computer program. The results from this
assessment indicated that the calcium carbonate species has the
greatest potential for precipitation in the leakage from the
dewatering bin sample. The next greatest potential for the same
species was in the cooling tower blowdown. The lowest potential was in
the recycle stream prior to the recirculation pump. In this case, the
maximum precipitation potential occurred in the stream in contact with
the coal ash for the greatest period of time.
In conclusion, a closed-loop bottom ash system is feasible at Plant
7281 by using discharge to an evaporation pond. The technical
problems associated with the equipment in the closed-loop system were
of a reconciliable design nature. The only significant equipment
problem exists because the settling tank was designed to handle all
the overflow fines from the dewatering bins. More modern systems pipe
these overflow fines back to dewatering bins. Chemically, there
seemed to be no major cycling of trace elements and major species
concentrations as a result of the closed-loop operation. It appears,
however, that the concentration of copper increases as a consequence
of sluice water being in contact with the coal ash. Contact w.ith the
384
-------
Table VII-26
TRACE ELEMENTS/PRIORITY POLLUTANTS1
CONCENTRATIONS AT PLANT 3203
(ug/1)
Cooling Tower Leakage from
Slowdown Dewatering Bin
pH
Temp. (°F)
Silver
Arsenic
Beryllium
Cadmium
Chromium
Copper
Mercury
Nickel
Lead
Antimony
Selenium
Thallium
Zinc
8.20
96
71
<0.52
<0.5
15
21
<2
<0.5
<3
8
5" -.
160
1 0 .40
<0.5
<0.5
24
49
<2
<0.5
4
<2
40
Recirculation
Pump
8.20
96
26
<0.5
i.5
19
5
<2
<3
5
<2
40
^.5
analyses were done for each sample speciesj the results
are. given as the average for each element.
2<,5 refers to the fact that the measured concentration was
less than 0.5 g/1, which is the detection limit for this
species.
NOTE: All concentrations reflect dissolved as opposed to total
concentrations.
385
-------
Table VII-27
MAJOR SPECIES CONCENTRATION1 AT PLANT 3203
;V -»-;.
(mg/1)
Cooling Tower Leakage from Recirculation
Calcium
Magnesium
Sodium
Phosphate^
Sulfate
Chloride
Silicate
Carbonate
Blowdown
395
190
645
0.40
2546
394
181
2520
Dewatering Bin
505
1
780
0,06
1773
601
27
60
Pump
310
105
770
2.30
1786
622
92
2760
analyses were done for each sample for Ca, Mg, Na; the
results are given as an aveage of the two values.
2A11 species except Ca, Mg, Na, were analyzed only oncej one
number is reported for each sample species.
NOTE: All concentrations reflect dissolved as opposed to total
concentrations«
386
-------
coal ash also increased the concentrations of calcium and sodium. The
potential for precipitation of CaCo3 exists in all three sampled
streams based on the scaling tendency calculations. The greatest
potential exists in the sluice water in the dewatering bin. This
means that increased recycle or continuous operation of the current
system can cause scale formation on pipes thereby reducing the flow
rate in the pipes.
Plant 0822. This plant is a 447 MW coal-fired powerplant located in
northwestern Colorado. The plant consists of two units: Unit 1
completed in 1965 and Unit 2 in 1976. The facility is a baseload
plant using cooling towers for condenser heat dissipation, dry fly ash
transport, and a zero discharge bottom ash sluicing system. The plant
burns a bituminous coal from USBM Coal District 17, The plant is
sufficiently close to the coal mine (nine miles) to be considered a
mine-mouth operation. Plant water is drawn from a nearby river. The
facility utilizes an RCC vapor compression distillation unit to
recover recycleable water from cooling tower blowdown. All final
wastewaters are ultimately handled by an evaporation pond. A general
description along with a flow diagram (figure .VI1-23'} of this plant
has been provided in the fly ash subsection.
The flow scheme for the bottom ash sluice system is illustrated in
figure .VII-44. Bottom ash from the boiler is jetted tp one of two
United Conveyor dewatering bins (one bin is in operation while the
other is being drained). The overflow from the dewatering bin flows
by gravity to a solids settling tank. Sludge from the settled ash
material is pumped back to the hydrobin. The overflow from the
settling tank flows to the surge tank and then to the two centrifugal
pumps which supply water to the ash jet pumps. Makeup water, which
consists of cooling tower blowdown and some plant raw water, is added
to two ash water storage tanks. The makeup: water is directed either
to the surge tank or to the high- and low-pressure ash water pump
suction headers. Under normal operation, the ash water makeup equals
the water retained by the bottom ash after dewatering, the water used
for wetting fly ash prior to unloading and small losses from
evaporation in the bottom ash hopper. Any solids which settle to the
bottom of the surge tank are pumped as sludge back to the dewatering
b i ns.
Once the dewatering bin fills with bottom ash, the bottom ash sluice
is switched to the other bin. The filled bin is then drained of the
sluice water. When the bottom ash is sufficiently dewatered (after
about 8 hours), it is dumped into an open truck and hauled to the mine
for disposal. The sluice water makeup from the cooling tower blowdown
is treated with a scale inhibitor (NALCO). The cooling towers operate
between 8 and 10 cycles of concentration with a dissolved solids level
of 1,200 mg/1.
The current bottom ash sluice system was designed as a part of Unit 2.
Thus, for Unit 2, the system is an original design while for Unit 1,
it is a retrofit. Prior to the construction of the current system in
1975, the plant used a once-through sluice operation in which both fly
387
-------
Ui
00
03
(2) 2GO,000-g*lloi» *alt water itong*
fr«w tank* (cooling tower blowdoun)
Cooling
(2} centrifugal £ran«fer
PU»P8, 1500 (MB,
48' bead, 25 lip drive
¥ v
Devttercd
Bottom Aeh to
Disposal
To Ash S nidge
Drain Suap
Quantity of Bottom A»bl Coal 3,000" tons/day
101 Aolt - 500 ton/day and
101 Oottoa Aali -- SO tons/day
•louilaun fco
Evaporation Fond
High
preaaura
ccatrt- "
tugsl
feclrcu-
Intlon
3000 gp
7)0' be
TOO lip
drlv«
Figure VII-44
BOTTOM ASH HANDLING SYSTEM FOR PLANT 0822
-------
ash and bottom ash were sluiced to a pond. The solids resulting from
these operations have since been removed and disposed of at the mine.
The pond now serves as a water storage pond to be used in the event of
drought conditions.
j, • ' •
The bottom, ash handling system supplier for plant 0822 is United
Conveyor Corporation. The following discussion provides specific
information concerning the major equipment for the bottom ash handling
system.
Two ash water storage tanks hold the makeup water to the ash handling
system. These tanks have volumes of 200/000 gallons each. High and
low water level switches are used to control the water level in these
tanks.
Two Bingham horizontal end suction, back pullout, centrifugal pumps
each rated at 150 gpm, 48 feet head are driven by 25 HP, 1,200 rpm
Westinghouse motors. These pumps supply water to the surge tank from
the ash water storage tanks and are automatically controlled by surge
tank hi-low level switches.
Two high pressure pumps supply recirculation water to the jet pumps at
the bottom ash hoppers from the surge tank. These pumps are Bingham
horizontal, single stage, axially split, double suction centrifugal
pumps each rated at 3,000 gpm, 730 feet head and are driven by 700 hp,
3,600 rpm Reliance motors. Start-stop control switches are located on
the bottom ash panel.
; • .
Three low pressure ash water pumps supply ash water from the surge
tank at a pressure of approximately 50 psig to the surge and settling
tanks for sludge removal and flushing, and to the bottom ash hopper
for fill, seals, flushing, i and overflow supply. These pumps are
Bingham horizontal end suction, back pullout, single stage centrifugal
pumps each rated at 1,000 gpm, 130 feet head and are driven by 50 hp,
1,800 rpm Westinghouse motors. Automatic controls are located on the
bottom ash panel and manual controls are locally placed.
The "jetpulsion" pumps are jet pumps located beneath the cylinder
grinders. These pumps create the force necessary to convey the ash
and water to the dewatering bins. Water for the "jetpulsion" pumps is
supplied by the high pressure ash water pumps. These jet pumps are
controlled on and off by associated two-way rotary sluice gates
located in the discharge line of each pump. The sluice gates are
solenoid operated from the bottom ash control panel by OPEN-CLOSE
switches.
Each of the two dewatering bins is designed to provide a net storage
volume of 12,700 cubic feet or approximately 48 hours bottom ash
storage capacity with both 1 and 2 at full load. Also, each bin is
fitted with a 12 kw chromolox electric heater and an ash level
detector which activates an alarm and a light on the control room
panel when maximum ash level is reached. At this point the conveyor
389
-------
is stopped, the diverting gates are switched, and the conveying
operation is then restarted by an operator.
Separate settling and water surge tanks are provided to recover the
ash water used in the handling of bottom ash and pyrites. The
settling tank is sized to provide flow-through water velocities
sufficiently low to precipitate most particulate matter larger than
100 microns. Sufficient volume is provided in the surge tank to
absorb the severe imbalance between input and output flows that occur
when the system progresses through the ash transport and dewatering
cycle.
The manpower increase due to the retrofitted ash handling systems is
15. This number includes both fly ash and bottom ash systems for both
maintenance and operation.
The maintenance problems with the bottom ash handling system are
nominal. The most frequently recurring problem is the erosion of the
impellers and casings of the high pressure recirculation pumps. There
are no problems with fines in the operation of the dewatering bins,
e.g., screen plugging or overflow into the settling tank causing
plugging of the sludge pumps. Some problems arose in retrofitting the
bottom ash system; the usual pipe rerouting, use of old pipe, and
outage time were required for the system installation.
Samples were taken at three different locations in the bottom ash
sluicing system. These locations were:
1. A sample was taken of the system-makeup stream from the cooling
tower blowdown water,
2. A sample was taken of the settling tank overflow to the surge
tank, and
3. A sample was taken from the surge tank.
These samples provide an indication of the trace elements, major
species, and carbon dioxide content of transport streams before and
after the surge tank, and of makeup water to the system. The trace
elements which were analysed include silver, arsenic, beryllium,
cadmium, chromium, copper, mercury, nickel, lead, antimony, selenium,
thallium, and zinc. . The major species analyzed were magnesium,
calcium, sodium, phosphate, sulfate, chloride, silicate, and carbon
dioxide. The results of these analyses are reported in tables VII-28
and VI1-29.
The sampling results indicate that the contact of the sluice water
with the bottom ash, as reflected in the settling tank overflow
species values relative to the other two streams, raises the
concentrations of some species. The trace elements, which increased
due to ash contact are silver, cadmium, chromi'um, selenium, and zinc.
For the major species, an increase in carbonate concentration is
reflected in the carbon dioxide values. Decreases in concentration
390
-------
Table VII-28
TRACE ELEMENTS PRIORITY POLLUTANTS CONCENTRATIONS1.2
AT PLANT 0822 .
Cooling Tower
Slowdown
Settling Tank
Overflow
Surge Tank
6.7
126.0
3.0
<0.5
<0.5
<2.0
15.0
<0.2
<0.5
<3.0
5.0
6.0
410
trace element analyses were done in duplicate; the two
values were averaged.
All concentrations are for the dissolved, not total,
concentration.
The value <0.5 indicates that the concentration was below the
detection limit which in this case is 0.5 ppb for beryllium.
pH
Temp. (°F)
Silver
Arsenic
Beryllium
Cadmium
Chromium
Copper
Mercury
Nickel
Lead
Antimony
Selenium
Thallium
Zinc
8.0
89.0
<0.1
49 .0
<0.53
<0 .5
<2.0
47.0
<0.2
<0.5
<3.0
<1 .0
<2.0
<1 .0
95
6.3
130.0
0.4
3.0
<0.5
2.0
10.0
8.0
<0.2
<0.5
<3.0
<1 .0
5.0
<1 .0
145
391
-------
Calcium
Magnes ium
Sodium
Phosphate (P04>
Sulfate (804)
Chloride (C1-)
Silicate (Si02)
Carbonate
Table VII-29
MAJOR SPECIES CONCENTRATIONS1*2
AT PLANT 0822
(mg/1)
Cooling Tower
Slowdown
365
120
210
3.3
1215
211
57
60
Settling Tank
Overflow
365
92
145
0.17
1203
112
36
120
Surge Tank
370
90
150
0.09
1165
125
35
360
1Ca, Mg, Na were analyzed in duplicate; values are averages.
2A11 values reflect dissolved, not total, concentrations.
392
-------
from the makeup source to the recycle loop are observed for arsenic
and copper and for magnesium, sodium, chloride, and silicate, which
indicates that a cycling effect does not exist in this system for
these species.
On the basis of the sampling analyses, the Agency determined the
tendencies for scaling for various species in the makeup and recycle
streams by using an aqueous equilibrium program. The amount of
scaling which may actually exist is contingent upon the amount of the
species present and any other inhibitor additives which may be
present. Only one sample species represented any driving force for
precipitation. This species was CaC03 for the cooling tower blowdown
makeup water stream.
In summary, this plant has achieved zero discharge by using
evaporation ponds. No significant mechanical problems have occurred
since the installation of this bottom ash system in 1974, and no
significant problems arose during the retrofitting procedure.
Chemically, some increase in trace element priority pollutants and
major species concentrations has been observed due to contact with the
ash. The potential exists for scaling CuCo3 in the makup water
stream. However, neither scaling nor corrosion has, been a problem in
the operation of this system.
Plant 1811. This plant is a 615-MW electric power generating station
located in Northern Indiana. The plant uses a wet recirculating
ponding system to handle bottom ash. This ash is generated by two
cyclone-type boilers of 194 and 422 MW each. The coal ash content is
10 to 12 percent with 11 percent as the average. This bituminous coal
is obtained from Bureau of Mines Coal Districts 10 and 11. The bottom
ash sluicing recycle system was retrofitted in the early 1970's. The
dry fly ash handling system was retrofitted early in 1979. Both of
these systems were designed and installed by United Conveyor
Corporation.
The bottom ash sluicing system is characterized by a bottom ash
storage area, a series of settling ponds, and a recirculation or final
pond. Figure VII-45 presents the sluice system flow diagram for the
plant. Only one primary and one secondary pond is used during
operation of the sluicing system. The sluice lines shown, other than
the bottom ash sluice, are used to transport sump water to the ponds.
Also, the discharge from a package sewage treatment facility is sent
to the primary settling pond;
The hydroveyor line, which was used to sluice fly ash to the ponds, is
used as a backup to the normal ash sluice pipes. The main sluice
pumps for the bottom ash are jet pumps which discharge at a pressure
of 230 psig at the runoff area. The larger unit 8 has two 10 inch
sluice lines (including one spare) which transport the ash one-quarter
of a mile to the slag runoff area. The smaller unit 7 has one 10 inch
sluice line. The flow rate used to transport the bottom ash to the
runoff area is approximately 2 MGD. The ash is sluiced for 1 to 2
hours each shift (depending on the load) with 10 minutes of flushing
393
-------
LO
'Sample 3
Recycle
Pump
(260 pal)
First
Forebay
(clear
oond)
secondary
Pond
Second
Secondary
Pond
r~^
Sewage
Treatment
Discharge
Line
(Unit
(Old Hydroveyor Sluice \
Lines Cor Fly Aeh /
Bottom
Ash
Sluice
(1.99 mgpd)
Lake Michigan
Makeup
Reclrculatlon Lines (2-16" lines)
Discharge/Hi Level
(Flow Rate Unknown)
A Sample location
Figure VII-45
PLANT 1811 FLOW DIAGRAM FOR BOTTOM ASH HANDLING
-------
before and 15 to 20 minutes afterwards. The surface areas of the two,
primary settling ponds are 4.2 acres (182,900 feet2) and 4.4 acres
(192,200 feet2). The areas of the two secondary ponds are 2.09 acres
and 3.66 acres. The forebay or final pond has an area of 0.1 acres
(5,188 feet2). Three centrifugal pumps are located at the forebay
which are used to recirculate the sluice water back to the bottom ash
pump (a distance of 1/2 mile) as well as the general plant water
system through one of two existing lines (16 inches diameter). These
recirculation pumps supply sluice water to the bottom ash pump at a
discharge pressure of 260 psig. A single pipe exists downstream of
the forebay recirculation pumps which allows for the discharge of
sluice water from the recirculating system. This discharge is
initiated during upset conditions but is under complete control of the
plant operators. This discharge is estimated to occur 2 days out of
7. The water is transported to Lake Michigan. Since this occurs
intermittently, the flow rate was difficult to quantify. Makeup water
to the bottom ash sluicing system enters the system at the sluice
pumps from Lake Michigan. Makeup water is required because of pond
evaporation, pond percolation, and water losses by removal of wet
bottom ash. The amount of ash handled by the bottom ash sluicing
system was estimated by 1978 FPC figures given by Plant 1811
personnel.
In 1978, the amount of bottom ash collected was 72,200 tons. The
operating and maintenance cost associated with the sluicing operation
was $67,300 for 1978. The hauling and disposal of the bottom ash at
the landfill site was contracted out and cost $86,900 in 1978. Some
of the bottom ash was sold which yielded $11,400.
Operating problems associated with the sluice system are nominal.
Occasional broken lines and ruptured slag pumps require periodic
maintenance, but this is considered normal. One major operating
problem is pond sluice water percolation. The ponds are located at a
higher elevation than a nearby plant and national park. These ponds
are not sealed and the sluice water seeps into offsite water systems.
The amount of percolation increases during periods of high water
levels in the pond. Future plants are expecting to build a lined pond
to prevent this percolation.
The operating manpower required to run the sluicing system is one man
part-time in the control room each shift and one man part- time
monitoring the slag sluicing operation. This requirement totals to
one man full-time for equipment maintenance. Most heavy maintenance
work is done during planned outages.
The recycle portion of the sluice system, i.e., the forebay and
recycle line~T was retrofitted in the early-1970's as a result of a
decision to collect all process waters at one location. No problems
were incurred due to the retrofit of the system.
Samples were taken at three different locations in the bottom ash
sluicing system. These locations, which are designated in figure VII-
45, are:
395
-------
1. the bottom ash discharge point,
2. the primary pond overflow, and
3. the forebay outfall.
These samples were taken to provide an indication of the levels of
trace elements and major species in the recirculating/sluicing system.
The trace elements assayed were silver, arsenic, beryllium, cadmium,
.chromium, copper, mercury, nickel, lead, antimony, selenium, thallium,
and zinc. The major species "assayed were magnesium, calcium, sodium,
phosphate, sulfate, chloride, silicate, and carbon dioxide. The
results of, these analyses are reported in tables VII-30 and VII-31.
The sampling results are inconclusive. Most of the concentrations are
low, except for the sulfate and zinc. There is essentially no
indication of an effect on trace metal concentrations due to contact
of the sluice water with the ash.
On the basis of sampling results, EPA determined the tendencies for
scaling for various species in the recycle streams by using an aqueous
equilibrium program. The results of this analysis indicated that the
potential for scaling of four major species was very low in all three
sample streams.
The feasibility of zero discharge using complete recycle with ponding
for bottom ash cannot be confirmed by the system used at this plant
because it requires intermittent discharge to maintain a steady-state
water balance in the system/ however there were no mechanical or
chemical problems related to the recycle operation. The problem with
percolation could be alleviated by lining the existing ponds.
Plant 1809. This plant is a 736 MW electric power generating station.
Four boilers currently in operation burn bituminous coal which has an
ash content of 10 to 12 percent. The boilers are of the wet bottom
cyclone type and produce a relatively large amount of bottom ash slag.
The plant utilizes a wet recirculating ponding -system to handle both
fly ash and bottom ash. Water is obtained from a nearby creek for use
in the sluicing operation. A flow diagram of the ash handling system
appears in figure VII-35.
The bottom ash sluicing system was retrofitted in 1974 along with the
fly ash sluicing system and Unit 12, the largest of the steam
generators (520 MW). All systems were designed and installed by
Allen-Sherman-Hoff, retrofitted for Units 4, 5, and 6, and new for
Unit 12. The principal reasons for installing the ash sluicing recycle
system were the requirements of discharge regulations and the decision
to collect and handle all process waters at one location. The fly ash
and bottom ash is produced at a ratio of 26 percent fly ash to 74
percent bottom ash. In 1978, approximately 48,600 tons of fly ash
were collected and 136,000 tons of bottom ash were collected.
396
-------
Table VII-30
TRACE ELEMENTS PRIORITY POLLUTANTS CONCENTRATIONS1.2
AT PLANT 1811
(ug/1).
pH
Temp. (°F)
Silver
Arsenic
Beryllium
Cadmium
Chromium
Copper
Mercury
Forebay
Outfall
6.5
77
<0 . 1 3
<1 .0
-------
Table VII-31
MAJOR SPECIES POLLUTANTS CONCENTRATIONS1
AT PLANT 1811
(mg/1)
Calcium
Magnesium
Soditm
Phosphate
Sulfate (S04)
Chloride (Cl)
Silicate (Si02>
Carbonate (003)
Forebay
Outfall
69
14
40
<0.06
273
8
5
60
Primary Pond
Overflow
54
11
43
<0.06
241
8
<3
300
Bottom Ash
Discharge
74
19
36
<0.06
250
8
4
600
Ca» Mg, Na were analyzed in duplicate; the values are
averaged.
values reflect dissolved, not total, concentrations.
398
-------
A jet pump sluices the bottom ash from the slag tanks to the bottom
ash runoff area. Two 12-inch diameter pipes are used to sluice the
bottom ash; one from the Boiler 12 slag tank and one from Boilers 4,
5, and 6 slag tanks. The bottom ash sluice water flow rate is
approximately 3 MGD. At t:he bottom ash runoff area, the bottom ash
slag is bulldozed into piles and is sold 'for use as a road bed
aggregate. The runoff area is composed of two primary ponds,
11,536,000 and 14,198,000 gallons capacity, and one small secondary
pond. Only one primary pond operates at a time. The bottom ash is
sluiced every 4 hours for 30 to 45 minutes. The piping used for
conveying the bottom ash is cast iron in the plant area and cast
basalt (Sch. 80) outside the plant area. From the secondary pond, the
sluice water overflows into the final pond for recirculation back to
the jet pumps.
At the final pond, facilities are available for a discharge to Lake
Michigan. These facilities consist of two pipes from the main
conveying lines to Lake Michigan for intermittent and upset
conditions. The discharge is actuated by gravity overflow. A
discharge condition prevails when Unit 12 is operating. Usually when
Units 4, 5, and 6 are operating and Unit 12 is down, the discharge
condition does not exist. The final pond also receives a large amount
of water from the , miscellaneous sump system; thus, during heavy
rainfall periods, a discharge condition often exists. Thus, Plant
1809 is not strictly a zero discharge plant. It does provide for a
discharge under fairly consistent conditions when Unit 12 is
operating. This discharge stream was not quantified by plant
personnel. The discharge is not used to prevent scaling of the ash
handling components, but is used solely to remove the surplus water
which accumulates. This surplus water is .being considered for use as
makeup to the cooling tower.
Operating problems associated with the sluice system are nominal.
Occasional instances of low pH have caused some pipe corrosion;
however, lime addition for pH adjustment has alleviated much of this
problem. Scaling has historically not been a maintenance problem.
Suspended solids have caused pump erosion problems on an intermittent
basis. Currently, the creek is used as the makeup water source. High
flow situations, e.g., after heavy rainfall, result in a poor quality
makeup water; also, incomplete bottom ash settling caused some wear on
pumps. Control of final pond water flow and installation of surface
booms for floating material collection has mitigated much of the
solids problem. The piping is rolled to maintain even wear on all
inside sluicing surfaces. This procedure is not unusual. One area
which requires significant maintenance is the sluicing jets and
recirculation pumps. These pumps do not have spares and therefore
must be frequently checked and maintained so as not to cause a
shutdown of the sluicing operation.
The primary ponds are cleaned annually and only one primary pond is
cleaned per year. Ash hauling is contracted to an outside trucking
firm.
399
-------
The bottom ash is sold for commercial use, which provides a credit for
the ash. According to the 1978 FPC data provided by the plant
personnel, the cost for collection and disposal of the bottom ash was
$79,200 and the sale of the bottom ash provided a $29,900 credit.
The bottom ash ponding recycle sluicing system for plant 1505 was
installed in 1974. At the same time the fly ash sluice water recycle
system and Unit 12 was installed. Thus, the recycle portion of the
pond system is a retrofit system for units 4, 5, and 6. The reason
for retrofitting a recycle system, i.e., a final pond and return line,
was in part due to discharge regulations since the plant is bounded by
a National Park, a town, and Lake Michigan. An additional motive was
to collect all discharge streams in the final pond for common
treatment, if needed.
The retrofit of the recycle line did not enable the plant to achieve
zero discharge because of water balance problems •. Water is
accumulated especially when Unit 12 is operating. The plant is in. a
low net evaporation climate. When the plant installed the
recirculation system, the already-existing main sluicing jet pumps and
the new recirculating pumps were not spared. This has presented a
maintenance problem and a need for redundancy by the plant is
recognized.
The plant claims that it is difficult to achieve zero discharge by
retrofitting a recycle loop on a ponding system for two reasons: it
is difficult to tie up all the streams into one collection point, and
it can be done only if the already-existing systems can be totally
segregated. There is also the effect on electricity generation to be
considered; higher auxiliary power .requirements reflect lower net
power generation. Plant 1809 personnel indicate that the technology
to retrofit bottom ash systems is more available than that for
retrofitting fly ash recycle systems. Cyclone boilers produce mostly
bottom ash; however, cyclones are no longer available as a
technology, primarily only way for plant 1809 to meet a zero discharge
requirement is to install evaporators which would increase the
auxiliary power requirements.
Any new expansion of generating capabilities would have to be met with
pulverized coal boilers. No market for bottom ash from these boilers
has been found by plant 1809 personnel, so the bottom ash handling
systems would have to be segregated. Also, facilities to handle a
larger percentage of fly ash would be installed with a pulverized
unit.
Samples were taken at three different locations in the bottom ash
sluicing system. These locations are shown in the bottom ash sluicing
system diagram in figure VII-35 and are described as follows:
1. A sample was taken of the miscellaneous sump water,
2. A sample was taken of the bottom ash pond overflow, and
400
-------
3. A sample was taken of the recirculating water from the final pond.
These samples provide data on the trace element, major species, and
carbon dioxide content of transport streams at the settling ponds and
of the sump water before the ponds. The trace elements analyzed for
were silver, arsenic, beryllium, cadmium, chromium, copper, mercury,
nickel, lead, antimony, selenium, thallium, and zinc. The major
species assayed were calcium, magnesium, sodium, phosphate, sulfate,
chloride, silicate, and carbon dioxide. The results of these analyses
are presented in tables VI1-32 and VI1-33.
Results from the sampling of trace elements indicate that only one
concentration increased due to exposure to the bottom ash. The
concentration of nickel in the bottom ash pond overflow is higher than
in the final pond effluent which serves as the makeup water to the
bottom ash sluicing system.
On the basis of this sampling and analysis, the tendencies for scaling
in the sluice streams were determined through an aqueous equilibrium
program. Based on the aqueous equilibrium results, calcium carbonate
theoretically has the greatest potential for precipitation in the
sluice water from the final pond; next greatest in the bottom ash pond
overflow, and the least potential in the miscellaneous sump stream.
None of the streams indicated a high scaling potential.
The feasibility of a closed-loop zero discharge operation cannot be
established based on the information available from this plant since
there is fairly continous discharge. This discharge is due to an
inherent accumulation of water in the recyle loop under certain
operating conditions.
LOW-VOLUME WASTES
One treatment technology applicable for the treatment of low- volume
waste streams is vapor-compression evaporation (VCE). Although this
method of waste treatment is energy intensive, it yields a high-
purity treated water stream and significantly reduces the wastewater
effluent flow. A number of the low-volume waste streams described in
Section V are suitable for VCE treatment. These streams are:
1. Water Treatment
- Clarifier blowdown^(underflow)
- Make-up filter backwash
- Lime softener blowdown
Ion exchange softener regenerant
- Demineralizer regenerant
Reverse osmosis brine
- Evaporator bottoms
2. Boiler blowdown
3. Floor and laboratory drains.
401
-------
Table VII-32
TRACE ELEMENTS/PRIORITY POLLUTANTS CONCENTRATIONS'1 »2
AT PLANT 1809
(ug/1)
1
Sluice Water from
Recirculation Pond
Bottom Ash
Pond Overflow
Miscellaneous
Sump
pH
Temp <°F)
Silver
Arsenic
Beryllium
Cadmium
Chromium
Copper
Mercury
Nickel
Lead
Antimony
Selenium
Thallium
Zinc
7.9
80
<0.13
66
<0.5
0.7
3
5
<1 .0
17
<2
9
4
62
70
7.9
85
<0.1
12
<0.5
1 .0
<2
3
<1.0
29
<2
8
<2
56
50
7
80
<0
12
<0
1
3
16
4
<3
3
<3
<2
6
100
.7
.1
.5
.0
.0
samples were analyzed in duplicate, the values were
averaged .
analytical values are for dissolved concentrations , the
samples were filtered initially.
value <.1 indicates that the concentration was below the
detection limit which is 0.1 g/1*
402
-------
Table VII-33
MAJOR SPECIES CONCENTRATIONS1^
AT PLANT 1809
(mg/D
Sluice Water from
Recirculation Pond
Bottom Ash
Pond Overflow
Miscellaneous
Sump
Calcium
Magnesium
Sodium
Phosphate (PQ4>
Sulfate (804)
Chloride (Cl)
Silicate (Si02>
Carbonate (003)
125
60
50
0.06 '
633
16
6
1080 ;
115
58
48
<0.063
650
18
5
1020
63
24
19
0.11
149
14
5
1800
lCa, Mg, Na samples were analyzed in duplicate; the results
were averaged.
2These concentrations reflect dissolved, not total,
concentration.
3The value <.06 reflects a concentration below the detection
limit which in this case is 0.06 tn'g/1.
403
-------
The VCE process concentrates non-volatile effluents from these
sources. This produces a concentrated brine which is usually ponded
in arid regions or sent to a pond or treated in a spray dryer in non-
arid regions (49).
Process Description
A schematic flow diagram of a VCE system is shown in figure VII-46.
The wastewater is first treated in a feed tank to adjust the pH to
between 5.5 and 6.5 for decarbonation. The stream is then pumped
through a heat exchanger to raise its temperature to the boiling
point. In some instances, softening may be required to prevent
scaling in the heat exchanger. After passing through a deaerator
which removes dissolved gases, the hot waste stream is combined with
the slurry concentrate in the evaporator sump. This slurry is
constantly recirculated from the sump to the top of the evaporator
tubes. The slurry flows as a thin film down through the tubes and
vaporizers. The vapor is compressed and introduced to the shell side
of the tube bundle. As this stream condenses, it transfers its heat
of vaporization to the brine slurry. The cohdensate that results on
the shell side is pumped through the feed preheater to transfer as
much heat as possible to the process before it is discharged from the
unit. A portion of the brine slurry is continuously drawn off from
the sump to maintain a constant slurry concentration (200,000 to
400,00 mg/1 solids) (51, 52).
The formation of scale is avoided on heat transfer surfaces by
preferential precipitation of calcium sulfate silica on seed crystals
in the slurry. In addition, a small temperature difference across the
heat exchanger tubing minimizes scale formation on the evaporating
surfaces (39).
Effectiveness
VCE systems have taken streams containing between 3,000 and 50,000
mg/1 of total dissolved solids (TDS) and have yielded a brine stream
containing 200,000 to 400,000 mg/1 TDS and a stream of water
containing less than 10 mg/1 TDS. In the event that there are
significant amounts of priority pollutants present in the feed stream,
it may be necessary to attach additional treatment equipment to the
deaerator vent, e.g., carbon adsorption or incineration.
Brine Slurry Concentration and Disposal
Evaporation Ponds
For areas of the country where the net annual evaporation rate (gross
evaporation minus rainfall) exceeds 20 inches a year, use of
evaporation ponds .for disposal of VCE waste brines may be a viable
disposal method. Evaporation ponds are used as a final wastewater
disposal method throughout the electric utility industry, primarily in
404
-------
FEED
o
Ul
FEED
PUMP
PRODUCT -*-
HEAT
EXCHANGER
VENT
EVAPORATOR
STEAM
COMPRESSOR
TO WASTE
DISPOSAL
WASTE
PUMP
PRODUCT
PUMP
RECIRCULATION
PUMP
Figure VII-46
SIMPLIFIED, SCHEMATIC DIAGRAM OF A VAPOR COMPRESSION EVAPORATION UNIT (50)
-------
the southwestern states; however, land cost and governmental
regulations restrict the use of evaporation ponds at many plant sites.
Evaporation ponds use solar energy to evaporate wastewater and thereby
concentrate dissolved solids in the wastewater. The ponds are
constructed by excavation, by enclosing an area with dikes, by
building dams, or by a combination of these methods. Ponds may
require a liner to prevent seepage of wastewater into the natural pond
water supplies. Typical liners are clay, asphalt, and PVC sheets.
The area required for a single evaporation pond can be estimated by
equation 24:
Area (acres) * 19.5G (24)
V
where G is the wastewater flow rate in gallons per minute and V is the
effective net evaporation rate in inches per year.
The effective net evaporation rate of pond water is less than the area
net evaporation rate. This occurs because of the decreasing pond
water vapor pressure with increased dissolved solids content of the
pond water. Consequently, some systems use ponds in series where the
effective evaporation rate of the first ponds is greater than the
evaporation rate of the latter ponds. The pond depth required is
equal to the wastewater flow rate in acre-feet per year divided by the
pond area in acres required for evaporation. Additional depth is
required for solids build-up in the pond.
Spray Drying
For areas of the country where evaporation by ponding is not feasible,
thermal drying of the waste brine to produce a solid for disposal by
land fill is an option. Spray dryers have been proposed as a suitable
method for thermal drying of VCE waste brines.
In a spray dryer, the VCI waste brine is atomized either by a spray
nozzle or a high-speed rotating disk. Hot combustion gases contact the
atomized brine in the drying chamber and vaporize the water. The hot
flue gases and dryed brine crystals pass through a baghouse for brine
crystal removal before being vented to the atmosphere. Moisture
content of the dried brine crystals is less than 5 percent (51).
METAL CLEANING WASTES
As explained in Section V, metal cleaning wastes are, periodic
discharges that may occur only infrequently at many power stations.
Since they are infrequent, many plants prefer to have them hauled off
and treated by private contractors. Most of the expertise for
treating cleaning wastes has been developed by the cleaning
contractors. Current treatment methods include incineration, ash
basin treatment, and physical-chemical treatment. . In addition,
treatment by vapor compression evaporation also has been considered.
406
-------
Treatment Methodologies
Disposal by Incineration (Evaporation). Incineration (evaporation) of
boiler chemical cleaning solutions has gained increasing popularity
since its first commercial application in 1971 (53). A number of
utilities have used such a process for disposal of waste boiler
cleaning solutions of various types, including ammoniated EDTA,
ammoniacal bromate, citric acid, and hydroxyacetic/formic acid
containing ammonium bifluoride (54, 55, 56). To date, well over 125
such incinerations of ammoniated EDTA waste solutions alone have
occurred.
The incineration procedure involves the controlled injection of spent
boiler cleaning chemicals into the firebox of an operational boiler
(see figure VII-47). As the solution is injected, water is vaporized
and the organics are combusted. The organic materials are reduced to
such compounds as N2, C02, and H20 while iron and copper deposits from
the cleaning are transformed to oxides (57). These boiler chemical
cleaning wastes are combustible to some extent due to these organic
molecules and metal compounds. Ammoniated EDTA has been estimated to
have a heat value of 2,000 Btu/pound.V
Injection rates are dependent on the fan and fuel capacity of the
boiler and must be determined on an individual basis. However, the
gallon per minute incineration rate has been equivalent to
approximately 2 to 5 percent of the steam flow of the boiler in a
number of cases (58). Injection rates range from 20 to 180 gallons
per minute. -,.
Solvent injection has been tested in coal, oil, and gas fired boilers,
both above and below the burners, and at various spray angles. Tests
have shown that disposal through incineration has successfully
captured metals. At times, as high as 98 percent iron and 95 percent
copper from the injected waste solutions have been retained in the
furnace; ., . „
The transition of metal ions to oxides is chemical in nature. These
oxides are then physically transformed to small particles and either
leave the stack or are trapped as deposits between the point of
combustion and the stack outlet. Since ash is primarily composed of
metallic oxides in various proportions, it would be expected that
deposition would occur along with bottom or fly ash, in pollution
control equipment or on walls of the furnace or stack.
Other substances which are of concern ., were also evaluated in
incineration studies. Such cases concerned the disposal of .ammoniacal
bromate, and hydroxyacetic/formic acid containing ammonium bifluoride.
Thermogravimetric analysis revealed that sodium bromate was converted
to sodium bromide and oxygen at 752 F and that no obnoxious products
were formed at temperatures up to 1,850 F (54). Actual incineration
tests on these solutions in a 860 F boiler revealed no liberation of
halogen gas or other obnoxious gases.
407
-------
iSWWiiriifeSft^^tffiSisV'n
SEE DETAIL
Figure VII-47
TYPICAL PIPING DIAGl^M AND LOCATION FOR INCINERATION
OF BOILER CHEMICAL CLEANING WASTES (68)
408
-------
Some tests conducted during incineration of boiler cleaning wastes
have shown that sulfur dioxide (SO2) and the oxides of nitrogen (NO )
have been reduced in stack emissions. Explanation of the lower NO
levels may stem from, the dissociation of water, which replaces oxygen
supplied by air thereby lowering the air and nitrogen supply to the
furnace (58).
Ash Basin Treatment. A number of utilities employ ash ponds for the
treatment of boiler chemical cleaning wastes (57, 59). The theory
behind such a treatment scheme is that the chemical/physical nature, of
the ash pond environment will treat those wastes as well as
conventional lime treatment.
A number of basic characteristics of the ash pond are utilized to
treat these wastes. The most important characteristic is pH, since
metals are removed as precipitated hydroxides above a certain pH.
Many ash ponds are naturally alkaline and thus have a good potential
for metal-hydroxide formation.
The presence of fly ash in ash ponds also appears to be an aid in the
treatment scheme (60). Fly ash has been used in water treatment to
increase the rate of floe growth and to enhance floe settling
properties. Some studies have shown that ashes which raise the pH of
ash sluice water can be expected to precipitate heavy metals (60).
In one of the demonstration projects on ash basin treatment, dissolved
oxygen content of the aslv pond was felt to, be an important factor
(60). In theory, its presence1 provided the oxidizing potential to
convert iron ions from the ferrous to the ferric state, the latter
which could be precipitated at a lower pH than the former.
The dilution factor of the ash pond is also felt to be important in
breaking the ammonia complex bond in the ammoniacal. bromate solution,
thus allowing the precipitation of copper. In order to achieve
equivalent metal removal, the increase in the concentration of the
metal in the ash pond effluent must be equal to or less than the
concentration achievable by lime precipitation divided by the dilution
factor.
Physical/Chemical Treatment. A number of treatment schemes employing
physical/chemical processes have been tested, designed, and
implemented for the treatment of boiler chemical cleaning wastes. The
basic mechanism behind these treatment schemes involves neutralization
with caustic or lime followed by precipitation of the metal hydroxide
compounds (57, 61, 62, 63, 64, 65). However, there are a number of
additional unit processes which have been employed on certain waste
chemical solutions in order to increase the degree of attainable
reduction of certain constituents. These additional unit processes
include: mixing with other metal cleaning waste sources, oxidation,
sulfide addition, filtration, and carbon adsorption.
In the treatment of. waste boiler chemical cleaning solutions the use
of these unit processes, either alone or in combination with others,
409
-------
is dependent upon which waste solution is being treated. Various
characteristics of individual waste streams make the use of certain
unit processes feasible. A description of the use of these processes
as they apply to boiler chemical cleaning wastes follows.
Ammoniated Citric Acid. Ammoniated citric acid boiler cleaning wastes
contain amounts of complexed iron and copper. Chelation of iron by
citrate is the first step of the two step process which is followed by
ammonia addition to complex copper. Dilution is necessary ' to
dissociate the ammonia-copper complex and will aid in breaking the
iron-citrate chelate. Adjustment of pH upwards will further lower the
degree of complexation as figure VII-48 illustrates.
Aeration of this waste has been recommended in order to oxidize
cuprous and ferrous ions to the eupric and ferric state, thus lowering
the pH needed to precipitate the copper and iron (57).
Addition of sodium sulfide after aeration under acidic conditions, in
one treatment scheme reduced metal concentrations due to the
precipitation of metal sulfides. In this treatment scheme, clarif,'ier
overflow was filtered through a dual media gravity filter to produce
final effluent with iron and copper concentration below one (I) mg/1
(57).
Ammoniated EDTA. Waste ammoniated EDTA boiler and chemical cleaning
solutions are difficult to treat due to the metal complexes which are
present. EDTA is a hexadentate ligand which chelates iron, .while the
ammonia forms complexes with copper. However, these wastes are
effectively treated to below the one (1) mg/1 level for iron and
copper using a combination of unit processes.
Dilution in plant wastes such as air preheater wastes and boiler
fireside wastes have effectively achieved the dissociation of these
complexes and subsequent removal of the copper (57, 66). The presence
of sulfides in these wastes, resulting from burning sulfur-containing
fuels, helps remove copper by the formation of insoluble copper
sulfide (57, 67). When dilution is followed by lime addition to pH
levels of approximately 13, reduction of iron and copper levels below
1 mg/1 may be achieved (57). Addition of a polymer to aid in
flocculation has" been used in order to achieve maximum removal of
metals (57).
Amtnonical Sodium Brornate. Reduction of total copper in waste
ammoniated sodium bromate solutions first requires the, dissociation of
the ammonia-copper complexes. This step is required in order to free
the copper, thus allowing it to form insoluble hydroxide precipitates.
Figure VII-49 illustrates the degree of complexation of NH3 on Cua+ to
be a function of dilution. In the left hand graph, pCu2* first
increases as ammonia equilibrium forces it to enter into solution
(thereby shifting the copper species to the lower ammoniated form)
then decreases as dilution effects predominate. The second graph
shows the degree of complexation decreasing with dilution due to the
410
-------
Figure VII-48
COMPLEXING OF Fe(III) (69)
The degree of complexation is expressed in terms of pFe for
various ligands (10""%). The competing effect of H+ at low pH
values and of OH at higher pH values explains that effective
complexation is strongly dependent on pH. Mono-, di- and tri-
dent ate ligands (10~ZM) are not able to keep a 10~3M Fe(III) in
solution at higher pH values.
-------
pCu
6
8
IO
12
10-
4[Cu(H)]«[lVl]
H2NCH2CH2NH;
10"* !0"3 !0"4
ApCu
[CuOU]-
Figure VII-49
THE CHELATE EFFECT ON COMPLEX FORMATION OF Cu-aq2+
WITH MONODENTATE,- BIDENTATE AND TETRADENTATE AMINES.
pCu IS PLOTTED AS A FUNCTION OF CONCENTRATION IN THE
LEFT-HAND DIAGRAM. IN THE RIGHT THE RELATIVE DEGREE OF
COMPLEXATION AS MEASURED BY pCu AS A FUNCTION OF
CONCENTRATION IS DEPICTED (69)
412
-------
increase in the Cu2+ species. Although other factors such as
temperature and ionic activity affect solubilities, dilution will aid
in the dissociation of the ammonia/copper complex.
Once this dissociation is accomplished, aqueous copper may be
precipitated with hydroxides. Addition of lime (Ca(OH2)) provides the
necessary hydroxides and precipitation will occur at approximately pH
* 10. Flocculation may be enhanced with addition of an organic
polymer flocculating agent. Sedimentation may be followed by the
passage of the supernatent through a granular media filter to insure
effluent quality. Reduction of iron and copper to below the one mg/1
level was accomplished using the overall treatment scheme in Figure
VII-50.
Hydrochloric Acid Without Copper Complexer. Many times HC1 (without
coppercomplexer)is"used inconjunction with ammoniated sodium
bromate solutions, and will be incorporated with the treatment scheme
for that solution. However, it may be used for removing heavy scales
in boiler systems which do not contain copper, and thus the waste
solution will not contain these relatively hard-to-break copper
complexes. Effluent levels for iron and copper below one mg/1 are
expected as treatment levels attainable for metals will approach
theoretical solubilities when pH is adjusted.
Figure VII-51 shows theoretical solubilities of a number of metals as
a function of pH. From the diagram it may be seen that those metals
found in waste hydrochloric acid cleaning solutions may be removed
below 1 mg/1 with pHs adjusted to approximately pH =10. The
adjustment of pH may be with the lime, or sodium hydroxide, although
sludge dewaterability is best when lime is used.
The treatment scheme employed for this waste stream is pH adjustment,
sedimentaiton, and (possibly) polishing of supernatent with some form
of filtration.
Hydrochloric Acid with Copper Complexer. Thiourea and Cutain II are
two copper complexing agents which have been employed along with
hydrochloric acid for the cleaning of boiler systems containing copper
alloys. Successful treatment of these wastes, to obtain total metal
residuals for iron and copper of below 1 mg/1 each (61), involves
breaking the copper complex and precipitating metal hydroxides.
Thiourea and Cutain II are multidentate ligands and, as such, are more
stable than the ammonia-copper complex, ammonia being a monodentate
ligand. Therefore, the same degree of dilution of these hydrochloric
wastes to dissociate the complex is not as effective as it is for the
degree of complexation.
In most cases, dilution occurs by combining acid stage wastes with
rinse waters or other metal cleaning wastes. The effect of such
dilution may be found in bench-scale test data contained in table VII-
34. In this case, wastes were diluted and pH was adjusted to 9.5,
where metals were precipitated and then the samples were filtered.
413
-------
WASTE
BOILER
CLEANING
SOLUTION
DILUTION
I
J
' 1
SEDIMENTATION
GRANULAR
MEDIA FILTER
Ca(OH)9 FLOC
z AGENT
EFFLUENT
WASTE
SOLIDS
WASTE
SOLIDS
Figure VII-50
TREATMENT SCHEME FOR METALS REMOVAL BY
PRECIPITATION FROM WASTE BOILER CLEANING SOLUTION
-------
100
10
1.0
Te
0,1
I /
7
0.01
0,001
.Fe
O-OOOI
\
K
\
\
Cu
\
\
V
An.
(Cd
*:
Fe
Ni'
\
y
9
PH
IO
ii 12
Figure VII-51
THEORETICAL SOLUBILITIES OF METAL
IONS AS A FUNCTION OF pH (69)
415
-------
Table VII-34
TREATMENT OF ACID CLEANING WASTEWATER
SUMMARY OF JAR TESTS (61)
Concentration (mg/1)
Dissolved
Metals
Zn
Ni
Cu
Fe
Mn
V
T^"i T iTf"n mn
LfjL -L wl U .L U tl
prior to
treatment
Before
Treatment
335
375
306
5,140
41
0.8
0.02
0.04
0.03
0.14
.01
.1
90 « 1
£.\J • I
After Ti
0.045
0.13
0.34
0.31
.01
.1
1 O ' 1
1 U . 1
reatment
0.2
0.31
0.32
0.60
0.04
.1
H • 1
J . i
0.74
2.9
0.35
0.52
0.12
0.5
pH adjusted to 9.5 with lime
Source: Design Report Wastewater Treatment Facilities
England Power Service Company
New
416
-------
-------
Table VII-35
EQUIVALENT TREATMENT OF INCINERATION TESTS
Waste Characteristics
Volume
Iron
Copper
Nickel
90,850 liters
727.27 kg
163.64 kg
36.36 kg
Volume 218,039 liters
Iron 4142.74 kg
Copper 69.77 kg
Percent Equivalent Treated
Retained Effluent Concentration
94 480 tng/1
88 216 mg/1
90 40 mg/1
81 3456 mg/1
94 19 mg/1
418
-------
Ash Pond Treatment. The mechanisms believed to be incorporated by
the chemical/physical nature of ash ponds for treatment of boiler
cleaning wastes are the same as those which were found to be effective
in physical/chemical treatment processes (i.e., dilution, oxidation,
pH adjustment, precipitation). However, with the ash ponds, control
of these variables may be difficult (if not impossible) and thus the
question of attainment of effluent limitations. The level achievable
in the ash pond must be equal to the original level in the ash pond
prior to metal cleaning waste addition plus the value determined by
dividing the effluent limitation (1 mg/1) by the dilution factor.
Because of the accuracy and precision of the analytical methods, such
demonstration may not be possible in some cases.
Physical/Chemical Treatment. Physical/chemical treatment methods have
been used successfully to treat solutions of chelated metals. By
employing various unit processes, it is possible to have control of
all reactions needed to reduce the levels of heavy metals in waste
boiler cleaning chemical solutions to below the one mg/1 level. Table
VI1-36 shows the treatment levels of various treatment schemes.
COAL PILE AND CHEMICAL HANDLING RUNOFF
One treatment technology applicable to coal pile and chemical handling
runoff is chemical precipitation/sedimentation. Chemical
precipitation is discussed in the ash handling subsection of this
section. Sedimentation is discussed in the 1974 Development Document
(46).
Flue Gas Cleaning Discharges,
In general flue gas cleaning processes employing wet scrubbing make
maximum use of recycle of slurry water. Typical systems use
thickeners which produce a high solids waste stream which is ponded
and a supernatent which is recycled to the scrubber. The solids
settling is typically accomplished in a pond where much of the water
is retained as a part of the settled sludge. This water which
overflows the pond is either recycled or discharged.. While it was
originally believed that most, if not all, such systems could operate
in a closed-loop or zero discharge mode supporting data to confirm
this is not available. The Agency plans to continue research into
scrubber system discharges and their control.
419
-------
Table VII-36
PHYSICAL/CHEMICAL TREATMENT PROCESSES
AND EFFICIENCIES
Waste Type and
Treatment Scheme
Hydrochloric acid with
copper complexer
Dilution 4- precipitation
at pH =* 1 sedimentation
filtration (61)
Parameter
Fe.
Cu
Zn
Ni
Mn
Effluent
Concentration
(mg/1)
0.01
0.14
0.02
0.04
0.01
Ammoniated EDTA
H2S addition 4- precipita-
tion at pH « 13 4-
sedimentation (57)
Fe
Cu
0.5
0,61
Ammonical brornate 4-
hydrochloric acid
Dilution 4- precipitation
at pH - 8.2 sedimentation
4- filtration (66)
Fe
Cu
Zn
Ni
*
*
*
*
^Indicates that the value is below the detection limit.
420
-------
SECTION VIII
x
COST, ENERGY, AND NON-WATER QUALITY ASPECTS ^
- - - ^-**"^
The cost, energy, and land requirements, of the various treatment and
control technologies described in section VII are presented in this
section for typical steam electric powerplants. For most
technologies, the costs are estimated for 25, 100, and 1,000 MW
plants. For some of the fly ash handling technologies, the costs are
estimated for 25, 100, 200, 350, 500, and 1,000 MW plants, in order to
provide better information regarding the change in fly ash handling
costs with decreasing plant size. Only summary information is
provided in this section. A discussion of the non-water quality,
environmental effects of the various treatment and control
technologies is also provided in this section.
COOLING WATER
Once- Through Cooling Water Systems
The capital cost, operating and maintenance costs, energy
requirements, and land requirements have been evaluated for the
following technologies:
- Chlorine minimization,
— Dechlorination,
- Alternative oxidizing chemicals
- bromine chloride
- chlorine dioxide
- ozone, and
- Non-oxidizing biocides.
Chlorine Minimization
Cost, Energy, and Land Requirements. Summary cost, energy and land
requirements for chlorine minimization at both new and existing plants
are presented in table VIII-1. The requirements for retrofitting an
existing plant are identical to the requirements for a new. plant.
Non-Water Qua! i tv Aspects . Chlorine minimization is not expected to
have any non-^water quality environmental effects.
Dechlorination
Energy., and Land Requirements. Summary cost, energy and land
requirements at both new and existing plants for dechlorination of
once-through cooling water systems are presented in table VI I 1-2. The
requirements for retrofitting an existing plant are identical to the
requirements for a new plant.
421
-------
Table VIII-1
SUMMARY OF COST, ENERGY, AND LAND REQUIREMENTS FOR
CHLORINE MINIMIZATION IN ONCE-THROUGH COOLING WATER SYSTEMS
Capital Cost ($)
Operation and Maintenance
($/year)
Energy Requirements
(kwh/year)
Land Requirements (acres)
Plant Size (MW)
25 100
36,000 37,000
9,200
9,100
1 ,000
38,700
8,500
negligible negligible negligible
none none none
Table VIII-2
SUMMARY OF COST, ENERGY, AND LAND REQUIREMENTS FOR
DECHLORINATION IN ONCE-THROUGH COOLING WATER SYSEMS
25
77,000
20,000
Capital. Cost ($)
Operation and Maintenance
($/year)
Energy Requirements
(kwh/year)
-and Requirements (acres) none
Plant Size (MW)
UK) 1 .000
91,500 127,000
36,400
84,900
5.6x104 1.12K105
none none
422
-------
Non-Water Quality Aspects. Dechlorination is not expected to have any
non-water quality environmental effects.
Alternative Oxidizing Chemicals ,
*"*
Chlorine Dioxide. Summary cost, energy and land requirements for
biofouling control with chlorine dioxide are presented in table VIII-
3.
Non-Water Quality Aspects. Chlorine dioxide use in once-through
cooling water systems is not expected to have any non-water quality
environmental effects.
Bromine Chlorine. Summary .cost, energy and land requirements for
biofouling control with bromine chloride in once-through cooling water
systems are presented in table VII1-4.
Non-Water Quality Aspects. Bromine chloride use in once-through
cooling water systems is not expected to have any non-water quality
environmental effects.
Ozone. Summary cost, energy and land requirements for the use of
ozone as a biofouling control agent in once-through cooling water
systems are presented in table VIII-5.
Non-Water Quality Aspects. The use of ozone in once-through cooling
water systems is not expected to have any non-water quality
environmental effects. An ozone destruction system is installed as
part of the ozonation facility which prevents the release of ozone to
the atmosphere.
Recirculating Cooling Water Systems
The capital cost, operatipnal and maintenance costs, energy
requirements, and land requirements have been evaluated for the
following technologies:
- Dechlorination,
Vapor Compression Distillation,
- Alternative Oxidizing Chemicals
chlorine dioxide
- bromine chloride
ozone,
- Non-Oxidizing Biocides,
Corrosion and Scaling Control, and
- Asbestos Cooling Tower Fill Replacement.
423
-------
Table VIII-3
SUMMARY OF COST, ENERGY AND LAND REQUIREMENTS FOR
BIOFOULING CONTROL WITH CHLORINE DIOXIDE IN ONCE-THROUGH
COOLING WATER SYSTEMS
Plant Size (MW)
25_ 100 1 ,000
Capital Cost ($) 19,000 19,400 20,200
Operation and Maintenance
($/year) 15,800 25,300 65,800
Energy Requirements
(kwh/year) 1.24x104 1.24x10^ 1.24x10^
Land Requirements (acres) negligible negligible negligible
Table VIII-4
SUMMARY COST, ENERGY AND LAND REQUIREMENTS FOR
BIOFOULING CONTROL WITH BROMINE CHLORIDE IN ONCE-THROUGH
COOLING WATER SYSTEMS
Plant Size (MW)
25 100 1.000
Capital Cost ($) 51,600 52,600 95,200
Operation and Maintenance
($/year) 21,800 28,700 61,800
Energy Requirements
(kwh/year) 1x104 1.3x104 1.81x104
Land Requirements (acres) negligible negligible negligible
424
-------
Table VIII-5
SUMMARY COST, ENERGY, AND LAND REQUIREMENTS: FOR
BIOFOULING CONTROL WITH OZONE IN
ONCE-THROUGH COOLING WATER SYSEMS
Plant Size (MW)
25 100 1.000
Capital Cost ($) 560,000 930,000 2,350,000
Operation and Maintenance
($/year) 12,500 16,200 31,600
Energy Requirements
(kwh/year) 9.1x10^ 1.66x10$ 5.59x105
Land Requirements (acres) negligible negligible negligible
Table VIII-6
SUMMARY COST, ENERGY AND LAND REQUIREMENTS FOR.
DECHLORINATTON OF RECIRCULATING COOLING SYSTEM DISCHARGE
(SLOWDOWN)
Plant Size (MW)
15 100 1.000
Capital Cost ($) 54,200 54,200 57,200
Operation and Maintenance
($/year) 6,100 6,100 6,300
Energy Requirements
(kwh/year) 1.6x1o3 1.6x10^ 1.6x103
Land Requirements (acres) negligible negligible negligible
425
-------
A discussion of the non-water quality aspects of each technology is
also included.
Dechlorination , .
Cost, Energy, and Land Requirements. Summary cost, energy and land
requirements for dechlorination at both new and existing plants using
recirculating cooling water systems are presented in table VII1-6.
The requirements for retrofitting an existing plant are identical to
the requirements for a new plant.
Non-Hater Quality Aspects. Dechlorination of cooling tower blowdown
is not expected to result in any non-water quality environmental
effects.
Vapor Compression Distillation
Cost, Energy, and Land Requirements. Summary cost, energy and land
requirements for vapor compression distillation of cooling tower
blowdown are presented in table VIII-7.
Non-Water Quality Aspects. Vapor compression distillation of cooling
tower blowdown does not have any non-water quality environmental
effects.
Alternative Oxidizing Chemicals
Chlorine Dioxide. Summary cost, energy and land requirements for the
use of chlorine dioxide as a biofouling control agent in recirculating
cooling water systems are presented in table VIII-8.
Non-Hater Quality Aspects. The use of chlorine dioxide as a
biofouling control agent at plants with recirculating systems is not
expected to involve any non-water quality environmental effects.
Bromine Chloride. Summary cost, energy and land requirements for the
use of bromine chloride as a biofouling control agent are presented in
table VIII-9.
Non-Water Quality Aspects. The use of bromine chloride as a
biofouling control agent at plants using recirculating cooling systems
is not expected to have any non-water quality environmental effects.
Ozone. Summary cost, energy and land requirements for the use of
ozone as a biofouling control agent in plants using recirculating
cooling water systems are presented in table VIII-10.
Non-Water Quality Aspects. The use of ozone as a biofouling control
agent at plants using recirculating cooling water systems is not
expected to have any non-water quality environmental effects.
426
-------
Table VIII-7
SUMMARY COST, ENERGY AND LAND REQUIREMENTS FOR VAPOR
COMPRESSION DISTILLATION OF COOLING TOWER SLOWDOWN
Plant Size (MW)
11 100 t.OOO
Capital Cost ($) 1,620,000 2,280,000 10,200,000
Operation and Maintenance
($/year) 46,500 51,000 124,000
Energy Requirements
(kwh/year) 2.61x1Q5 1.12x1Q7 7.25x107
Land Requirements (acres) 0.12 1.0 5.8
. Table VIII-8
SUMMARY COST, ENERGY AND LAND REQUIREMENTS FOR
BIOFOULING CONTROL WITH CHLORINE DIOXIDE IN
RECIRCULATING COOLING SYSTEMS
Plant Size (MW)
25 100 1,000
Capital Cost ($) 19,100 19,100 19,300
Operation and Maintenance
($/year) 8,500 9,500 18,500
Energy Requirements
(kwh/year) ;l.24x1Q5 1.24x105 1.24x10^
Land Requirements (acres) negligible negligible negligible
427
-------
Table VIII-9
SUMMARY COST, ENERGY AND LAND REQUIREMENTS FOR
BIOFOULING CONTROL WITH BROMINE CHLORIDE IN
RECIRCULATING COOLING SYSTEMS JD
Plant Size (MW)
25 JJD£ 1 ,000
Capital Cost ($) 36,600 36,900 52,300
Operation and Maintenance
($/year) 15,800 17,100 26,600
Energy Requirements
(kwh/year) 6.5x103 7.5x103 1.2x103
Land Requirements (acres) negligible negligible negligible
Table VIII-10
SUMMARY COST, ENERGY AND LAND REQUIREMENTS FOR
BIOFOULING CONTROL WITH OZONE IN RECIRCULATING
COOLING SYSTEMS
Plant Size (MW)
25_ 100 1 ,000
Capital Cost ($) 96,600 210,000 690,000
Operation and Maintenance
($/year) 7,800 9,000 13,800
Energy Requirements
(kwh/year) 1x104 2.2x104 1.06x104
Land Requirements (acres) negligible negligible negligible
428
-------
Non-Oxidizing Biocides
Cost, Energy> and Land Requirements. As detailed in Section VII, the
technology evaluated for the control of the discharge of priority
pollutants contained in non-oxidizing biocide formulations is
substitution. No additional cost, energy or land requirements are
expected to be involved in the use of nonpriority pollutant mixtures
as shown in table VI11-11.
Non-Water Quality Aspects. Switching to non-priority pollutant-
containing, non-oxidizing biocides is not expected to have any non-
water quality effects.
Corrosion and Scaling Control Chemicals
Cost, Energy, and Land Requirements. As detailed in Section VII, the
technology evaluated for the control of the discharge of priority
pollutants contained in scaling and corrosion control formulations is
substitution. The additional cost, energy and land requirements
incurred in switching from a priority pollutant-containing, scaling
and corrosion control mixture ' to one that contains no priority
pollutants are presented in table VIII-12.
Non-Water Quality Aspects. Switching to non-priority pollutant-
containing, scale and corrosion control chemicals, is not expected to
have any non-water quality effects.
Replacement of Asbestos Cooling Tower Fill
The technology evaluated for the control of the discharge of asbestos
in cooling tower blowdown is the replacement of the asbestos fill
material with fill material of ceramic, PVC, or woods. The cost for
asbestos cement fill replacement is extremely site-specific. Factors
such as the current fill configuration, plant location, fill chosen
for replacement, local labor wages and availability, proximity to
appropriate asbestos fill disposal site and time available for fill
replacement (cooling tower must-be out of service) all affect the cost
of fill replacement. The general range of the fill replacement costs
can be estimated from repair work done by cooling tower manufacturers
in the past. In one such case, the existing asbestos cement fill was
damaged due to problems with the water chemistry of the recirculating
water. This resulted in the leaching of calcium carbonate from the
asbestos cement which brought about rapid fill deterioration. In
another case, water freezing in the fill brought about serious damage.
In both instances, complete fill replacement was necessary. Cost data
from these two jobs is summarized in table VII1-13.
The numbers which appear in the table serve as only general guidelines
and may vary as much as 50 percent due to site- specific conditions.
The costs include the labor cost for removal of the old fill, the cost
of the new fill material which was of PVC or other asbestos-free
composition, and the labor cost to install the new fill. They do not
include the cost of disposal of the old asbestos cement fill. In the
429
-------
Table VIII-11
SUMMARY COST, ENERGY AND LAND REQUIREMENTS FOR SWITCHING
TO NGN-PRIORITY POLLUTANT CONTAINING NON-OXIDIZING BIOCIDES
Capital Cost (§)
Operation and Maintenance
($/year)
Energy Requirements
(kwh/year)
Land Requirements (acres)
Plant Size (MW)
25 100 1,000
None None None
The OSM cost (chemical purchase cost)
of non-priority pollutant non-oxidiz-
ing biocides is less than for chlori-
nated phenols.
None
None
None
None
None
None
Table VIII-12
SUMMARY COST, ENERGY AND LAND REQUIREMENTS FOR SWITCHING
TO NON-PRIORITY POLLUTANT CONTAINING CORROSION AND
SCALE CONTROL CHEMICALS
Capital Cost ($)
Operation and Maintenance
($/year)
Energy Requirements
(kwh/year)
Land Requirements (acres)
Plant Size (MW)
11 100
None None
1 ,800
5,200
1 ,000
None
36,000
negligible negligible negligible
negligible negligible negligible
430
-------
Table VIII-13
COOLING TOWER FILL REPLACEMENT COSTS
Size of Plant
Cooling Tower
Was Servicing
(MW)
700
900
Type
of
Fuel
Fossil
Nuclear
Cost of
Materials
(Million
Dollars
1979)
2
4
Cost of
Labor
(Million
Dollars
1979)
1
2
Total
Cost
(Million
Dollars
1979)
3
6
4,31
-------
case of the 700- megawatt plant, some additional modifications to
increase the thermal capacity of the tower were done at the time of
the asbestos fill replacement. This brought the total cost of that
project to about $3.5 million while effecting about a 15 percent
increase in thermal capacity.
Labor costs were estimated to run between one-third and one-half of
the total replacement cost. This cost will vary depending on how the
labor force is scheduled (How much overtime is involved? How many
workers are onsite simultaneously?). At the 700- megawatt fossil
unit/ it was estimated that the entire job could be completed in 10
weeks, with 120 to 200 workers on site simultaneously, working 10 hour
days, 5 days per week. This works out to a total of about 75,000 man-
hours. In actuality, the replacement work at the 700-megawatt plant
is being done in two installments of 5 weeks each. It is possible to
break fill replacement work down such that as little as one quarter of
the work is done in one installment. This allows most of the fill
replacement work to be done during normally scheduled plant outages
thus reducing the otherwise enormous cost of plant shutdown for fill
replacement purposes.
The operational costs of the tower may decrease upon asbestos fill
replacement if the new fill and other tower modifications increased
the tower efficiency. Yearly savings amounting from this are
extremely site-specific.
The data indicate that costs in the range of $1-9 million can be
expected for asbestos fill replacement allowing for the +50 percent
accuracy of the costs. Nuclear plants place a higher heat load on a
cooling tower per megawatt of generated power when compared to fossil-
fueled plants. As a result, the cost of fill replacement per unit of
generated power will run higher for nuclear plants.
Non-Water Quality Aspects. The asbestos fill removed from the cooling
tower may be considered a hazardous waste and require appropriate
disposal.
ASH HANDLING
Fly Ash
Three treatment and control options for discharges from fly ash
handling systems are costed in this section. They ares
1. Dry fly ash handling,
2. Partial recirculation of sluice water, and
3. Once-through sluicing with chemical precipitation. •
Use of dry fly ash handling includes dry vacuum and dry pressure
pneumatic conveying systems. Partial recirculation includes ponding
and recycle of the sluice water with a continuous untreated discharge.
432
-------
The once-through sluicing system involves sluicing the ash to a pond
with the sluice water passing through a chemical precipitation system
prior to discharge. The information presented for the fly ash
handling systems includes capital costs, operating, and annual
maintenance costs, energy requirements, and land requirements.
Dry Fly Ash Handling
Both pneumatic vacuum conveying and pneumatic pressure conveying were
evaluated. Technical descriptions of these two systems can be found
in chapter VII. The costs of each system were addressed separately
and then were combined into a "composite" cost for a.typical plant by
consideration of the number of plants using each technology.
Dry fly ash handling capital costs are presented for these two
technologies in terms of new plants and existing plants. Existing
plants have an additional cost factor included for each case, the
retrofit costs. The quantification of this factor was estimated
because retrofit costs are very site specific. In all cases except
the chemical precipitation system, the retrofit cost will equal the
cost, to install the system. The chemical precipitation retrofit cost
was estimated to be 10 percent of the installation cost. This cost
reflects a number of items: labor to take out existing equipment,
labor to reroute existing piping, resulting downtime to install the
new system, etc. New plants will not have to contend with this added
cost. The engineering and contingency estimate was 20 percent of the
installed system with retrofit cost.
Capital Costs for Dry Fly Ash Handling Systems. The capital costs for
dry fly ash handling systems are presented in table VII1-14. All
equipment, except for the dry storage silo, was costed for an ash
conveying rate equal to twice the actual ash generating rate. The silo
was sized based on a 72-hour storage capacity. A factor of 2.5 times
the total equipment cost was used to estimate the total installed cost
of the system. In addition, for existing plants, the retrofit cost was
estimated as equal to the cost for installing the equipment.
Engineering and contingencies were estimated as 20 percent of the
installed system costs with retrofit penalties. Table VIII-14 presents
costs which include all of these factors.
Operating and Maintenance (O&M) Costs. The nominal ash disposal cost
assumed for dry fly ash handling was based on the assumption that the,
plants would have to dispose of the ash material regardless of any
water discharge regulations and the difference in operating costs for
disposal will be minimal. These O&M costs are presented in table
VIII-15.
Energy Requirements. The energy requirements for either the vacuum or
pressure systems involve, for the most part, the power requirements
for the blowers. The range of power requirements for these blowers is
from 38 KWto 180 KW at 150 TPH of fly ash. Other energy-consuming
equipment included were the silo aerators, unloaders, vent return line
433
-------
Table VIII-14
CAPITAL COSTS FOR DRY FLY ASH HANDLING SYSTEMS
Capital .Costs
(million dollars)
Existing Plants
New Plants
25
2.33
1.45
Plant Size (megawatts)
100 200 350 500
2.96
.1.90
3.35
2.16
4.77
3.14
5.37
3.54
1000
10.05
6.76
Table VIII-15
ANNUAL OPERATING AND MAINTENANCE COST FOR DRY FLY ASH
HANDLING SYSTEMS
Operation and Maintenance
(million dollars /year)
Existing Plants
New Plants
25
Plant Size (megawatts)
100 200 350 500
0.347
0.348
0.373
0.377
0.405
0.412
0.459
0.471
0.509
0.526
1000
0.690
0.724
-------
blowers, and silo heating coils, Table VII1-16 presents the annual
energy requirements for the vacuum and pressure systems.
Land Requirements. The land requirements for the dry fly ash handling
systems are given in table VIII-17. Land is required to contain the
silo, blowers, and piping.
Non-Water Quality Aspects. The use of dry handling and disposal of
fly ash over ponding will have, a direct impact from the standpoint of
solid wastes disposal. Landfilling of the ash material must be
conducted in an environmentally sound manner. 'If proper landfill
operations are used, the potential problems of fugitive dust and
leaching of ash into groundwater can be contained.
Partial Recirculating and Chemical Precipitation of Fly Ash
The technologies which are addressed in these two categories are (1)
ponding of the fly ash with partial recycle of the sluice water, and
(2) ponding of the fly ash with total discharge of sluice water after
chemical precipitation. The partial recirculating system includes the
addition of a clear pond and a recycle line back to the fly ash sluice
pumps. The second system includes the addition of a chemical
precipitation system. The costs and other requirements for these two
systems were addressed in the same manner as for the fly ash handling
systems. Similar assumptions were utilized for addressing new and
existing plants, pulverized and cyclone-fired boilers.
Capital Costs. The capital costs for the wet fly ash handling systems
are presented in table VII1-18. The equipment upon which the partial
recirculation capital costs were based are a clear pond, piping, and
pumps. The once-through sluicing equipment is that associated with
the chemical precipitation system. Further description of these
systems can be found in chapter VII.
Operating and Maintenance Costs. The O&M cost assumptions for the
once-through system were solely based on the chemical precipitation
system operation. These O&M costs are presented in table VII1-19.
Energy Requirements. The energy requirements for these two systems
are presented in table VIII-20. The energy requirements for partial
recycle/fly ash were based ,on the energy used by the recycle pumps.
The wet once-through system requirements were based on those for the
chemical precipitation system.
Land Requirements. The land requirements for these two systems are
presented in table VIII-21. For the partial recirculating system, the
land requirement was based on a clear pond and piping from the pond to
the sluice pumps. For the wet once-through system, only the land
needed for the chemical precipitation system was estimated.
Non-Water Quality Aspects. The use of partial recirculation is not
expected to have any impacts over current operations. The use of
chemical precipitation will result in a lime sludge which must be
435
-------
Table VIII-16
ENERGY REQUIREMENTS FOR DRY FLY ASH HANDLING SYSTEMS
25
Energy Requirements
(million kilowatt-hours/year)
Existing Plants
New Plants
0.340
0.340
Plant Size (megawatts)
100 200 350 500
0.340 0.340 0.340 0.340
0.340 0.340 0.340 0.340
1000
0.916
0.980
Table VIII-17
LAND REQUIREMENTS FOR DRY FLY ASH HANDLING SYSTEMS
Land Requirements
(acres)
Existing Plants
New Plants
25
Plant Size(megawatts)
100 200 350 500
0.75
0.75
1.0
1.0
1.2
1.2
1.4
1.4
1.5
1.5
1000
2.0
2.0
-------
Table VIII-18
CAPITAL COSTS FOR PARTIAL.RECIRCULATING AND CHEMICAL
PRECIPITATION OF ONCE-THROUGH FLY ASH SLUICING SYSTEMS
(million dollars)
1. Partial Recirculation
Existing
New
Plant Capacity (MW)
25 100 1000
0.845
0.528
0.881
0.553
1 .700
1 .120
2. Once-Through Sluicing
with Chemical Precipitation
Existing
New
25
0.369
0.348
Plant Capacity (MW)
100
0.840
0.792
200
1 .272
1 .200
350
1 .781
1 .680
500
2.099
1 .980
1000
3.31
3.12
437
-------
Table VIII-19
OPERATING AND MAINTENANCE COSTS FOE PARTIAL RECYCLE AND
CHEMICAL PRECIPITATION OF ONCE-THROUGH FLY ASH SLUICING SYSTEMS
(million dollars/year)
1 . Partial Recirculation
Existing
New
Plant Capacity (MW)
25 100 1000
0.331
0.331
0.331
0.331
0.332
0.331
2. Once-Through Sluicing With
Chemical Precipitation
Existing
New
25
0.105
0.105
100
0.185
0.185
Plant Capacity (MW)
200 350 500
0.326
0.326
0.510
0.510
0.693
0.693
1000
1.12
1.12
438
-------
Table VIII-20
ENERGY REQUIREMENTS FOR PARTIAL ^CIRCULATING1AND WIT CHEMICAL
PRECIPITATION OF ONCE-THROUGH FLY ASH SLUICING SYSTEMS
(million kilowatt-hours/year)
1. Partial Recirculation
Existing
New
Plant Capacity (MW)
25 TOO 1000
0.160
0.160
0.630
0.680
8.13
8.94
2. Once-Through Sluicing With
Chemical Precipitation
Existing
New
"25 •
0.498
0.498
Plant Capacity(MW)
100 200 350 500
0.566
0.566
0.641
0.641
0.753
0.753
0.857
0.857
1000
1.09
1 .09
439
-------
Table VIII-21
LAND REQUIREMENTS FOR PARTIAL RECIRCULATING AND CHEMICAL
PRECIPITATION OF ONCE-THROUGH FLY ASH HANDLING SYSTEMS
(acres)
1. Partial Recirculation
Existing
New
Plant Capacity (MW)
25 100 1000
6.1
6.1
5.4
6.4
10,32
10.32
2. Once-Through Sluicing With
Chemical Precipitation
25
Existing
New
0.3
0.3
100
0.4
0.4
Plant Capacity (MW)
200 350 " 500
0.4
0.4
0.5
0.5
0,5
0.5
1000
0.7
0.7
Table VIII-22
CAPITAL COSTS FOR COMPLETE RECYCLE BOTTOM ASH HANDLING SYSTEM
(million dollars)
System
Complete Recycle with Softening
Existing
New
Plant Capacity (MW)
25 100 1000
1 .431
0.882
1 .569
0.967
2.508
1 .381
440
-------
disposed of in a properly operated landfill. Proper landfill
operation should insure against the possibility of leaching of
material in the sludge which may otherwise enter groundwater.
Bottom Ash
The discussion of bottom ash handling systems will include individual
presentations of capital costs, operating and maintenance annual
costs, energy requirements, and land requirements for 25, 100, and
1,000 MW 'typical' plants. The specific technologies associated with
bottom ash handling are represented in the contexts of complete
recycle and partial recycle. The concept of complete recyclie, as
discussed in chapter VII, involves the elimination of any direct
discharge from the sluice system.
Partial recycle allows for a continuous direct discharge from the
sluice system with the remainder of the sluice stream returned to the
main sluice pumps.
Complete Recycle
The technologies which are addressed in the complete recycle category
include hydrobin/dewatering bin systems, and ponding with recycle.
Both technologies in this case were considered in terms of complete
recycle by using slip stream softening. Costs for each of these
technologies were composited>in order to generate typical costs for a
given plant installing complete recycle bottom ash handling. Both
existing and new facilities are addressed. Existing plants have an
additional cost factor included for each case, the retrofit costs. In
all cases, the retrofit cost was assumed to equal the cost to install
the system, This retrofit cost reflects a number of items: labor to
take out existing equipment, labor to reroute existing piping,
resulting downtime to install the new system, etc. New plants will
not have to contend with this added cost.
Capital Cost. The capital costs are, presented in table VIII-22.'. for
the bottom ash handling systems which are considered for complete
recycle. The dewatering bins system/slip stream softening capital
costs were the summation of the dewatering bin system and slip stream
softening system costs. The slip stream softening system cost was
based on treatment of 10 percent of the ash sluicing stream. For
existing plants, an installation factor was considered to yield an
installed system cost of 2.5 times the equipment cost.
The retrofit penalty was considered to be equal to the cost of
installation; the engineering and contingency were estimated to be 20
percent of the installed system with retrofit penalty. New plants, of
course, were not penalized for retrofit costs.
The second major system that was costed for a complete recycle
scenario was ponding with recycle. The pond was assumed to be built 1
mile from the bottom ash sluice pumps. The slip stream softening
4A1
-------
system was assumed to treat 10 percent of the recycle stream and used
the same equipment as presented above.
Operating and Maintenance Costs. The maintenance materials criteria
were different for hydrobin systems and recycle systems. For hydrobin
systems, the maintenance materials cost was estimated to be 2 percent
of the equipment cost annually. For recycle, this annual cost was
assumed to be 1 percent of equipment cost. The slip stream softening
O&M costs were calculated based on the amount of sluice water treated.
A nominal ash disposal cost was assumed for the dewatering bin
systems; this cost was $1 per ton of bottom ash produced. This cost
was based on the assumption that the plants would have to dispose of
the ash material regardless of any water discharge regulations and the
difference in operating costs for disposal will be minimal. Costs'for
both alternative systems were composited in order to generate typical
costs for a given plant installing complete recycle bottom ash
handling. The operation and maintenance costs are presented in table
VIII-23.
Energy Requirements. The estimation of energy requirements was made
in terms of annual consumption of electricity. The requirements for
the dewatering bin systems were based on the pumping requirements.
Energy requirements for both systems were composited into typical
energy requirements for a given plant installing complete recycle
bottom ash handling. The energy requirements are presented in table
VIII-24.
Land Requirements. The land requirements for a complete recycle
system are given in table VIII-25. For recirculating systems, land
requirements were for the clear pond and piping from the clear pond to
the bottom ash hoppers. For the dewatering bin systems, land is
required for the bins, tanks and pumps and piping.
Non-Water Quality Aspects. The use of complete recycle may require
chemical softening of the recycle water. This would result in a lime
sludge which must be disposed of in a landfill. If proper landfill
operations are used, the potential problem of leaching into
groundwater can be contained.
Partial Recycle
The technologies which are addressed for bottom ash partial recycle
systems are the same basically as those presented for complete
recycle. The difference between the two scenarios is that the partial
recycle bottom ash handling systems will not include a slip stream
softening system.
The costs and other requirements were addressed in the same manner as
for the complete recycle systems. Similar assumptions were utilized
for addressing new and existing plants, pulverized and cyclone-fired
boilers.
442
-------
Table VIII-23
OPERATING AND MAINTENANCE COSTS FOR COMPLETE RECYCLE
BOTTOM ASH HANDLING SYSTEM
(million dollars/year)
Plant Capacity (MW)
System
Complete Recycle with Softening
Existing
New
25
0.440
0.440
100
0.445
0.445
1000
0.561
0.535
Table VIII-24
ENERGY REQUIREMENTS FOR COMPLETE RECYCLE BOTTOM ASH
HANDLING SYSTEM
(kwh/year)
System
Complete Recycle with
Softening
Existing
New
: Plant Capacity (MW) -
25 100 1000
1.19x105 1.96x105 1.48x106
1.12x105 1.53x105 1.04x1o6
443
-------
Table VIII-25
LAND REQUIREMENTS FOR COMPLETE RECYCLE BOTTOM ASH
HANDLING SYSTEM
(acres)
Plant Capacity (MW)
System 25. 100 1000
Complete Recycle
Existing 3.55 3.8 5.4
New 3.55 3.8 5.4
Table VIII-26
CAPITAL COSTS FOR PARTIAL RECYCLE BOTTOM ASH HANDLING SYSTEM
(million dollars)
Plant Capacity (MW)
System Z5 100 1000
Partial Recycle :
Existing 1.260 1.262 1.59
New 0.787 0.814 1.41
444
-------
Capital Costs. The capital costs for the partial recycle systems are
presented in table VIII-26. The equipment upon which these costs are
based, i.e., dewatering bins without slip stream softening and
recirculation without slip stream softening, may be found in the
capital cost discussion of complete recycle systems.
Operating and Maintenance Costs. The O&M annual costs estimated for
the partial recycle systems were established based on the same
assumptions as for the complete recycle technologies. The slip stream
softening O&M costs were omitted in the partial recycle cases. Table
VIII-27 presents the O&M cost requirements for the partial recycle
systems.
Energy Requirements. The energy requirements estimated for the
partial recycle systems were established based on the same assumptions
as for the complete recycle technologies. The slip stream softening
energy requirments were omitted in the partial recycle cases. Table
VII1-28 presents the annual energy requirements for the partial
recycle systems.
Land Requirements. The land requirements estimated for the partial
recycle systems were established based on the same assumption as for
the complete recycle technologies. The slip stream softening land
requirements were omitted in the,partial recycle cases. Table VIII-29
presents the land requirements for the partial recycle systems.
Non-Water Quality Aspects. No nonwater quality impacts are anti-
cipated as a result of requiring partial recirculation of sluice
water.
Low Volume-Wastes '
The technology costed for the treatment of low-volume wastes is vapor
compression evaporation (VCE). The sources of these wastes tend to be
intermittent and batch in nature, requiring a basin to equalize the
flow prior to treatment. The cost for diked impoundment of the water,
assuming $10,000 per impoundment acre, is shown in table VIII-30.
The installed battery limits costs for the VCE system are shown in
table VIII-31. The system , life is expected to be 30 years. The
materials of construction for the system are titanium, stainless steel
and special steel alloys.
The technologies costed for the disposal brine (evaporator bottoms)
are evaporation ponds and spray drying. The capital and operation and
maintenance costs for a typical diked clay-lined pond for 20 inches
per year net evaporation are presented in table VIII-32. These costs
are based on the following items:
dirt and excavation cost—$20,000 per acre, and
clay costs and installation—$20,000 per acre.
445
-------
Table VIII-27
OPERATING AND MAINTENANCE COSTS FOR PARTIAL RECYCLE
BOTTOM ASH HANDLING SYSTEM
(million dollars/year)
Plant Capacity (MW)
System 25 100 1000
Partial Recycle
Existing 0.355 0.359 0.421
New 0.355 0.357 0.395
Table VIII-2S
ANNUAL ENERGY REQUIREMENTS FOR PARTIAL RECYCLE BOTTOM ASH
HANDLING SYSTEM
(kwh/year)
Plant Capacity (MW)
System 25. 100 1000
Partial Recycle
Existing 0.99x105 1.72x105 1.42x106
New 0.92x105 1.30x105 9.80x105
446
-------
Table VIII-29
LAND REQUIREMENTS FOR PARTIAL RECYCLE BOTTOM ASH
HANDLING SYSTEMS
(acres)
System
Partial Recycle
Existing
New
Plant Capacity (MW)
25 100 1000
3.55
3.55
3.8
3.8
5.4
5.4
Table VIII-30
IMPOUNDMENT COST
25
Plant Size (MW)
100 1000
Capital Cost ($)
Operation and Maintenace
($/year)
Land Requirements (acres)
4,200
8,400
12,000
negligible negligible negligible
0.35 0.7 1.0
447
-------
Table VIII-31
COST OF VAPOR COMPRESSION EVAPORATION SYSTEM
Plant Size (MW)
11 J_00 1000
Installed Capital
Cost ($)* 1,140,000 2,040,000 2,880,000
Operation and Maintenance^3
($/year) 25,000 32,000 39,000
Energy Requirements
(kwh/year) 1.6x106 3.2x106 4.8x106
Land Requirements
-------
The capital and O&M costs as well as energy and land requirements are
presented in table VIII-33.
COAL PILE RUNOFF
For the treatment of coal pile runoff, two treatment and discharge
options are presented:
Option 1—equalization, pH adjustment, settling, and
Option 2—equalization, chemical, precipitation treatment,
settling, pH adjustment.
The costs of Option 1 include impoundment (for equalization), a lime
feed system and mixing tanks for pH adjustment, and a clarifier for
settling.
The costs for the impoundment area include diking and. containment
around each coal pile and associated sumps and pumps and piping from
runoff areas to impoundment area. The costs for land are not
included. The cost of impoundment for pH adjustment is shown in table
VIII-34.
•The lime feed system employed for pH adjustment includes a storage
silo, slaker, feeder, and lime slurry storage tank as well as
instrumentation, electrical connections, piping and controls. The
capital and O&M costs for pH adjustment are shown in table VIII-35.
Rubber-lined steel mixing tanks are employed to accommodate wastes
with a pH of less than 6. The capital and O&M costs as well as energy
and land requirements for mixing are presented in table VII1-36.
The clarifier is assumed to have a 3-hour retention time. The costs
of clarification are presented in table VII1-37.
The costs of Option 2 include, impoundment for equilization, a lime
feed system, mixing tank, and polymer feed system for chemical
precipitation, a clarifier for settling and an acid feeder and mixing
tank to readjust the pH within the range of 6 to 9. The equipment and
system design, with the exception of the polymer feeder, acid feeder
and final mixing tank, is essentially the same as for Option 1.
The costs for the impoundment area are the same as for Option 1 (refer
to table VIII-34).
The costs for the lime feed system are presented in table VII1-38.
The components of this sysem are the same as those for Option 1.
Two tanks are required for Option 2/ one for precipitation and another
for final pH adjustment with acid. The cost of mixing is therefore
twice that of Option 1 (refer to table VIII-36).
The polymer feed system includes storage hoppers, chemical feeder,
solution tanks, solution pumps, interconnecting piping, electrical
449
-------
Table VIII-33
COST OF SPRAY DRYING SYSTEM
Plant Size (MW)
25 100 1000
Installed Capital Cost (?) 600,000 648,000 744,000
Operation and Maintenance
($/year) 25,000 25,800 27,400
Energy Requirements (kwh/yr) 3.7x106 7.4x10^ 1.0x10?
Land Requirements (ft2) 800 800 800
Table VIII-34
COST OF IMPOUNDMENT FOR COAL PILE RUNOFF
Plant Size (MW)
25 TOO 1000
Installed Capital Cost ($) 4,500 4,500 9,000
Operation and Maintenance ($) negligible negligible negligible
450
-------
Table VI1I-35.
COST OF LIME FEED SYSTEM
' • ' Plant Size (MW)
25 100 1000
Installed Capital Cost ($) 91,200 168,000 258,000
Operation and Maintenance
($/year) 3,800 7,000 11,500
Energy Requirements (kwh/yr) 3.6xl04 3.6x104 3.6x1Q4
Land Requirements (ft^) 5,000 5,000 5,000
Table VIII-36
COST OF MIXING EQUIPMENT
Plant Size (MW)
,25 100 1000
Installed Capital Cost ($) 43,200 60,000 76,800
Operation and Maintenance
($/year) > 1,500 1,600 1,700
Energy Requirements (kwh/yr) 1.3x10^ 3.3x10^ 6.5x10^
Land Requirements (ft2) ; 2,000 2,000 2,000
451
-------
Table VIII-37
CLARIFICATION
Plant Size (MW)
25 100 1000
Installed Capital Cost ($) 120,000 156,000 186,000
Operation and Maintenance
($/year) 2,100 2,400 2,700
Energy Requirements (kwh/yr) 1.3x103 3.3x103 6.5x103
Land Requirements (acres) 0.07 0.11 0.16
Table VIII-38
COST FOR LIME FEED SYSTEM
Plant Size (MW)
25 100 1000
Installed Capital Cost ($) 91,200 168,000 258,000
Operation and Maintenance
($/year) 3,800 7,000 11,500
Energy Requirements (kwh/yr) 3.6x104 3.6x10^ 3.6x104
Land Requirements (ft2) 5,000 5,000 5,000
452
-------
connections and instrumentation. The costs of the polymer feed system
are shown in table VII1-39.
The cost of clarification is identical to that of Option 1 (refer to
table VIII-37).
Option 2 requires the use of an acid addition system to readjust the
pH within the range of 6 to 9. The components of this system include
a lined acid storage tank, <, two feed pumps, an acid pH control loop,
and associated piping, electrical connections and instrumentation.
The specific costs as well as energy and land requirements of the acid
feed system are presented in table VIII-40.
453
-------
Table VIII-39
COST OF POLYMER SYSTEM
Plant Size (MW)
25 100 1000
Installed Capital Cost ($) 1,200 1,500 1,500
Operation and Maintenance
($/year) 1,100 1,100 1,100
Energy Requirements (kwh/yr)• 2.2x1Q3 2.2x1Q3 2.2x1Q3
Land Requirements (ft2) 100 100 100
Table VIII-40
COST OF ACID FEED SYSTEM
Plant Size (MW)
25 100 1000
Installed Capital Cost ($) 22,800 36,000 51,600
Operation and Maintenance
($/year) 1,500 1,700 2,000
Energy Requirements (kwh/yr) 75 180 360
Land Requirements (ft2) 100 100 100
454
-------
SECTION IX
BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE
GUIDELINES AND LIMITATIONS, AND NEW SOURCE PERFORMANCE
STANDARDS AND PRETREATMENT STANDARDS
The technical information presented in the previous sections was
evaluated in light of the Water Pollution Control Act (P.L. 92-500)
as amended and the Settlement Agreement in NRDC vs. Train 8 ERC 2120
(D.D.C. 1976), modified at 12 ERC 1833 (D.D.C. 1976). The Agency has
determined, from the list of technology options, the best available
technology economically achievable and new source performance
standards for the following waste streams:
1. Once-Through Cooling Water
2. Recirculating Cooling Water Slowdown
3. Fly Ash Transport Water
4, Bottom Ash Transport Water
5. Metal Cleaning Wastes
6. Low Volume Wastes
7. Coal Pile Runoff
8. Ash Pile, Chemical Handling Area and Construction Area Runoff
9. Flue Gas Scrubber Discharge
The BATEA guidelines and limitations and NSPS are summarized in the
following discussion which includes a brief description of the
technology based limitations, an estimate of the uncontrolled
pollutant loadings associated with the waste streams, and an estimate
of the quantity of pollutants removed following application of BAT or
NSPS, .:.
Rationale for Proposal b^ Waste Streams
A. Once-Through Cooling Water
1 . Pollutants Present
The Agency detected several pollutants in once- through cooling water
discharges. Table VI-1 lists those pollutants detected at least once
in greater concentrations in the effluent than in the influent. The
pollutants present as a result of plant operation are copper,
chromium, nickel, sine, bromoform, chloroform, chlorodibromonethane,
and total residual chlorine (TRC).
455
-------
2< Need to control TRC
In general, chlorine is a strong oxidizing agent with a high
solubility in water. Numerous reports are available that document the
toxicity of chlorine and its byproducts to aquatic organisms.
Chlorine in water may be present as free available chlorine (hypo-
chlorous acid or hypochlorite ion) or combined residual chlorine
(mono-, di-, and tri-chloramines) or other chlorine derivatives.
Studies have shown that the toxicity to aquatic life is dependent on
the concentration of total residual chlorine (TRC) . remaining in the
water, including both free available and combined residual chlorine,
as well as the duration of contact. In estuarine/marine environments,
brominated compounds are formed instead. The term "residual oxidants"
is more appropriate than "residual chlorine" in such cases. Of about
550 plants with once-through cooling, EPA estimates that 335 use
chlorine for biofouling control.
3. Available technologies and techniques
Because of current requirements in Part 423, and because of state and
local requirements, many power plants already are making efforts to
reduce their TRC discharges. The principal ways in which to curtail
or eliminate TRC discharges include the following:
(a) no biocides —
The intake water quality at many plants is such that condenser
biofouling is not a problem. Characteristics of this type of intake
water include high turbidity, low dissolved oxygen or low
temperatures. Currently, 40 percent of the plants with once-through
cooling water do not chlorinate.
(b) use of alternative biocides Jto chlorine —
Some plants with biofouling problems use other biocides than chlorine.
The alternative biocides include chlorine bromide, chlorine dioxide
and ozone.
(c) chlorine minimization —
In the past, caution has dictated the liberal chlorination of
condenser tubes. Plant operators are discovering, however, that by
following careful operating, monitoring, and maintenance procedures,
they can significantly reduce the use of chlorine without impeding
effective biofouling control.
In essence, "chlorine minimization" is nothing more than a program
designed to assure the most efficient use of chlorine and reduce the
amount of TRC discharged. Such a program requires plant personnel to
conduct a number of tests to determine the minimum amount, of chlorine
necessary to control biofouling. Chlorination practices then can be
adjusted in accordance with the test results. Continued monitoring
and inspection of the condensers on a periodic basis is also required.
456
-------
Many power plants undergoing some form of chlorine minimization
program find that they do not need biofouling control at all; others
find that their current chlorine doses can be reduced significantly.
(d) dechlorination —
Some plants have installed chemical treatment devices that remove a
significant amount of TRC from the cooling water before it is
discharged from the plant. Most of these dechlorination devices use
sulfur dioxide or. sodium thiosulfate to accomplish TRC reduction. The
reaction products, if sulfur dioxide is used, are sulfate ions,
chloride ions and ammonium bisulfate. Each is present in low
concentrations and have been shown to have insignificant pH and
dissolved oxygen shift effect. This technology has been demonstrated
to be effective both in fresh and salt water media. This technology
reduces TRC to less than 0.14 mg/1 at any time (instantaneous
maximum).
(e) mechanical antifoulinq devices —
Some plants use mechanical devices/ either with chlorine or in place
of chlorine, to control biofouling. Two types of on-line mechanical
devices are used. One method uses sponge rubber balls of slightly
larger diameter than the inside diameter of the tubes to be cleaned.
The balls are fed to the inlet of the exchanger, forced through the
tubes under water pressure, removed at the downstream side of the heat
exchanger, and recycled. A second method uses brushes which are
installed in each tube. Movement of the brushes is induced by
periodic changes in the direction of the cooling water flow.
4. Proposed Regulation
a. BAT
The Agency is proposing to prohibit the discharge of total residual
chlorine (TRC); however, power plants that demonstrate a need for
chlorine to control condenser biofouling may discharge the minimum
amount of TRC necessary (chlorine minimization program). In no event
may a TRC discharge exceed 0.14 mg/1 maximum concentration at the
point of discharge. Moreover, TRC may not be discharged from any
discharge point for more than two hours per day unless the plant shows
that chlorination for a longer period is required for crustacean
control. The current Part 423 provision prohibiting simultaneous
chlorination of several units would be deleted. This provision is
already incorporated into the chlorine minimization requirements.
Section 301(b)(2)(A) of the Act requires the Agency to develop
limitations that will result in reasonable further progress towards
eliminating all pollutant .discharges. This section states that BAT
limitations must prohibit pollutant discharges if the Agency finds
this technologically and economically achievable.
457
-------
The Agency has determined that at many plants, a prohibition against
TRC discharges is technologically and economically achievable. As
noted earlier, about 40 percent of existing power plants with once-
through cooling do not chlorinate at all. Moreover, the Agency
believes that some plants now using chlorine could discontinue it
without adverse effect.
Many plants, however, must use chlorine or other means to control
biofouling because of the nature of their intake water. For such
plants, a total prohibition against TRC discharges may be neither
technologically nor economically achievable. Mechanical anti-fouling
devices are expensive to backfit, and are not always adequate
substitutes for chlorine. There is insufficient data to demonstrate
that the alternative biocides can substitute for chlorine under all
cases, or if they are more or less environmentally acceptable on a
national basis. This is not to say that the use of alternative
biocides and/or mechanical systems might not be appropriate in some
cases.
Dechlorination has been demonstrated to be effective from both
technical and economic standpoints. While dechlorination
significantly reduces the amount of TRC discharged, it does not
eliminate it.
Accordingly, the Agency has structured the proposed TRC regulation in
two basic parts. First, the proposed regulation contains a general
prohibition against TRC discharges. This is BAT for the many plants
that do not need chlorine for biofouling control. Second, the
proposed regulation requires that any plant which must control
biofouling must use only the minimum amount of chlorine demonstrated
to be necessary at that plant (chlorine minimization).
Plants needing to use chlorine to control biofouling in their once-
through cooling water must demonstrate to the NPDES permit-writer,
through the chlorine minimization study set forth in Appendix A of the
proposed regulations, how much chlorination is actually necessary at
the plant. Based on this study, the permit writer establishes a BAT
limitation for that plant (in terms of a TRC concentration level
(mg/1) as well as limits on the duration and frequency of chlorine
added) reflecting the minimum amount of chlorination necessary to
control biofouling. The limitations may vary seasonally or vary with
intake water temperature.
The proposed regulation specifies that in no event may a TRC
limitation exceed 0.14 mg/1 concentration at the point of discharge.
The Agency believes that many plants can achieve this limitation
merely by following the minimization program. In the event a plant
cannot meet this limit with minimization only, the plant could meet
the limitation by adding a dechlorination system. Thus, the proposed
BAT for plants that must chlorinate requires a minimization program in
all cases, and may require dechl'orination in some.
458
-------
The Agency considered the option of merely requiring minimization
without specifying a maximum TRC concentration level. Under this
option, no plant would be required by BAT to dechlorinate. The
Agency's conclusion, however, is that this approach would impede
reasonable further progress toward the elimination of TRC discharges
throughout the nation because some plants would be allowed to
discharge TRC at concentrations much greater than those which- can be
achieved by a technology (dechlorination) that is both technically and
economically available.
Another option was to specify a maximum TRC concentration level (based
upon dechlorination technology for plants that must chlorinate)
without first requiring that the plants minimize their use of
chlorine. The Agency has rejected this option because many plants
have the ability with economically and technologically available
procedures (chlorine minimization) to discharge a lower maximum TRC
concentration level than is generally achievable on a national basis
by dechlorination (maximum of 0.14 mg/1). Further, the chlorine
minimization program is environmentally advantageous in that it always
reduces, and in some cases eliminates, the discharge of chlorine.
Further, those plants that will be required to dechlorinate after the
chlorine minimization program will use less dechlorination chemicals.
The Agency believes that the proposed scheme best follows the mandate
of S301(b)(2)(A), which is that BAT should be no discharge unless it
is not technogically or economically feasible. The Agency's scheme
assures that there will be no TRC discharge at plants where this is
technologically and economically feasible, and limits discharges at
other plants to the maximum degree technologically and economically
feasible.
The Agency is also proposing to limit TRC discharges from plants that
must chlorinate to no more than two hours per day unless plant
personnel can demonstrate that discharges for longer periods are
necessary for crustacean control. This limitation is essentially the
same as that which is already in effect for free available chlorine.
Finally, the Agency is proposing to relax current Part 423 in one
respect. The current BAT regulation prohibits simultaneous chlorine
discharges from more than one unit at any plant, even if each unit is
meeting the maximum concentration and hours-per-day limitations. The
Agency is proposing to eliminate this restriction because plants with
multiple units may not be able to comply with the one unit at a time
restriction. The current Part 423 provision prohibiting simultaneous
chlorination of several units (unless a demonstration of need is made)
would be deleted. This provision is already incorporated into the
chlorine minimization requirements.
This change is necessary because the proposed discharge limitations
are more stringent than BPT and adequate biofouling control for multi-
unit plants, in some cases, may require multi-unit chlorination. It
should be noted that BPT provides for exemption from the "one-unit-at-
a-time" requirement if the need for multi-unit chlorination can be
459
-------
demonstrated. The minimization program required by this proposed
regulation is equivalent to the demonstration of need required under
BPT.
b, NSPS
The proposed NSPS is the same as the proposed BAT.
Section 306(a)(l) directs the Agency to set a NSPS which prohibits
pollutant discharges "where practicable." The Agency must also
consider costs. S306(b) (1) (B) . For the same reasons discussed in
part 4a above, practical considerations and high costs are the reasons
for not imposing an across-the-board prohibition on TRC discharges.
The Agency is accordingly proposing to make NSPS equivalent to BAT.
c. PSES
The proposed PSES do not restrict the discharge of any pollutants from
this wastewater source.
For PSES, the Agency is proposing no limitations on TRC because no
plants currently discharge their once-through cooling water to POTW's.
In addition, TRC dissipates in the POTW system.
d. PSNS
For PSNS, EPA is proposing no limitations on TRC or any other
pollutants. Because of the massive flows, it is unlikely that new
plants will discharge to POTW's. In addition, the TRC dissipates in
the POTW system.
S« Cooling Tower Slowdown.
1. P Present
Several pollutants detected in cooling tower blowdown discharges were
attributed entirely to their presence in the intake water. The
sampling data show that the following pollutants are being discharged
as a result of power plant operations: copper, nickel, zinc,
asbestos, benzene, chloroform, 2, 4-dichlorophenol, total phenolics and
TRC. Table VI-1 lists those pollutants that were detected at least
once in the EPA data base in greater concentrations in the effluent
than in the influent.
2. Need to control TRC and other chemicals added for cooling tower
maintenance
Chlorine is commonly added to cooling water to inhibit organism growth
in both the tower and the condenser. Of about 300 plants with
recirculating cooling systems, approximately 75 percent of these
plants use chlorine. The need to control TRC discharges was covered
in the previous discussion on once-through cooling water. In addition
to chlorine, other chemicals may be added to control scaling,
460
-------
corrosion, and biofouling of the tower itself. Scaling, corrosion,
and biofouling affect cooling tower performance and are the major
maintenance items that are commonly handled by chemical treatment-
Some of these chemicals contain priority pollutants.
3. Available technologies and techniques
(a) For control of TRC
The technologies and techniques for TRC control are essentially the
same as discussed for once-through cooling {Part IV (A)(3) above).
(b) For control of 129 toxic pollutants discharged from chemicals
added for cooling tower maintenance
Many power plants can avoid or minimize discharges of the 129 toxi.c
pollutants from the cooling tower blowdown stream by using chemicals
that do not contain the 129 toxic pollutants. Many plants are already
using some of these readily available chemicals.
(c) For control of all pollutants from recirculating cool ing water
systems
Some plants (principally in the southwest) do not discharge cooling
tower blowdown but use evaporation ponds to eliminate all discharges.
In areas where net evaporation is less than 20 inches/year, this is
not a practical technology. Vapor compression distillation (VCD) is
sometimes used to reduce the volume of wastewater to be evaporated and
to provide recovery of water for inplant use. VCD is a forced
evaporation system which evaporates over 90 percent of the water. The
vapor is condensed and reused by the plant as make-up water, and the
remaining 10 percent is a concentrated brine that is disposed of in
evaporation ponds or spray dryers.
(d) For control of heavy metals
An available option for removal of chromium and zinc is precipitation.
This treatment method involves the addition of chemicals to
precipitate the dissolved metals and sedimentation or filtration to
remove suspended solids. This technology is required under existing
BAT. This treatment method is effective in lowering amounts of
dissolved metals.
4. Proposed Regulation
a. BAT
The Agency is proposing to limit TRC discharges to a maximum
concentration of 0.14 mg/1 at any time. The Agency is also proposing
to prohibit the discharge of all chemicals used for tower and
condenser maintenance that contain any of the 129 toxic priority
pollutants. Plants with cooling towers are not required to
461
-------
demonstrate the need to chlorinate or to undergo a minimization
program.
For Control of_ TRC: One technology that is available to achieve the
.14 mg/1 TRC limit is dechlorination. In some cases, plants may be
able to meet this limitation without dechlorination by using other
good management practices, i.e., discontinuation of discharge for two
to three hours until the TRC dissipates inside the system.
The Agency is not requiring a chlorine minimization program because
such a program would be unduly complex for this stream (as compared to
once-through cooling) since chlorine may be required for cooling tower
maintenance as well as biofouling control in the condenser tubes.
Moreover, minimization is not as important in this waste stream
because the daily flow is commonly less than l/100th of the once-
through cooling water flow.
The Agency has rejected a no discharge limitation because it would
either require the use of alternative biocides for biofouling control
or would require vapor compression distillation. Some of these
alternative biocides may be as toxic as chlorine. The Agency does not
believe vapor compression distillation is a viable technology for the
treatment of this waste stream since disposal of the brine wastes in
an environmentally acceptable manner may not be technically feasible
in some cases and, may be too expensive in some geographical
locations.
Thus, because dechlorination is clearly technologically and
economically achievable, the Agency has determined that the 0.14 mg/1
limit, which can be met by dechlorination, is BAT for the control of
TRC. Meeting ,this limit will result in reasonable further progress
toward the Act's no discharge goal.
For control of. the 129 toxic pollutants; Many chemicals are available
for cooling tower maintenance that do not contain any of the 129 toxic
pollutants, and these chemicals can effectively and economically
protect cooling towers and system equipment from scaling, corrosion,
and biofouling problems. High levels of chromium and zinc are present
in cooling tower Slowdown only if they were added for tower
maintenance. Although precipitation reduces the discharge of these
chemicals, it will not be able to eliminate it as in the case of using
replacement material. Therefore, BAT for this stream prohibits the
use of chemicals containing the 129 pollutants (no discharge of
chemicals added for cooling tower maintenance).
For Control of Phosphorus; Phosphorus is used in cooling towers
primarily for scaling control. The existing BAT requires treatment of
phosphorus to 5 mg/1. The Agency has determined that this requirement
is not necessary because 1) the limited use of phosphorus in cooling
towers and 2) the environmental impact is quite site specific. The
Agency has determined that the environmental effect of this non-
toxic/non-conventional pollutant is adequately addressed by water
462
-------
quality standards. The proposed BAT is, therefore, relaxed in this
respect, and the current limitation for phosphorus will not apply. .
b. NSPS
The proposed NSPS controls for cooling tower blowdown are identical to
the proposed BAT controls. The same factors and considerations
discussed in the BAT section immediately above apply here.
c. PSES and PSNS
For PSES and PSNS, EPA is proposing no limitations on TRC because most
of the TRC dissipates before reaching the POTW and the remaining low
levels do not warrant control. For the 129 priority pollutants and
phosphorus, EPA is proposing PSES equal to BAT because the Act's
legislative history indicates that pretreatment standards should be
equivalent to BAT. Moreover, these pollutants (primarily chromium,
zinc, and pentachlorophenol) are not compatible with POTW treatment
and may interfere with POTW operation or limit their sludge disposal
options. For PSES and PSNS, the Agency is proposing no limitations on
phosphorus as in the case for BAT.
C. Ash Transport Water
1. Fly Ash
a. Pollutants Present
Table IV-1 lists those pollutants that were detected at least once in
the EPA data base in greater concentrations in the effluents than in
the influents. The following toxic pollutants are believed to be a
result of transporting fly ash: arsenic, antimony, beryllium,
selenium, nickel,, lead, chromium, copper, zinc, cadmium, mercury, and
thallium.
These materials enter the water primarily via dissolution of reactive
compounds on the surface of the fly ash particles. Only plants
handling fly ash with partially recirculating or wet once-through
systems contribute to this problem. Gas-fired and nuclear plants do
not .generate ash. Further, out of approximately 850'steam electric
plants, only 43 oil-fired plants and 183 coal-fired plants currently
discharge fly ash sluice water (many of the oil-fired facilities do
not collect fly ash and would not be affected by regulations for fly
ash transport water).
b. Need to control toxics from this stream
The sampling data demonstrates that toxic pollutants are present in
the fly ash transport water discharge stream; however, most of these
pollutants are also present in the plants' make-up or intake water
source. Data on concentrations of pollutants in the intake water and
fly ash transport water discharges are limited to seven of
approximately 25 plants (nationally) with separate fly ash ponds.
463
-------
These data do not demonstrate a consistent pattern. That is, at
certain plants the observed concentrations (or average concentrations)
of some toxics are higher in the intake water than in the ash pond
discharge while for other toxics the reverse is true. In other cases,,
effluent concentrations are higher than intake concentrations but the
observed values are close to or at the detectable limit for the
pollutant. The Agency's conclusion is that the present data base is
not sufficient to support any reasonable estimation of net discharges
of toxic pollutants for the industry from this waste source. This
conclusion is based on the small numbers of observations and the large
variation in the data.
3. Available technologies and techniques
(a) Dry fly ash transport
Currently 48 percent of the 352 coal-fired plants and 14 percent of
the 429 oil-fired plants in the country use dry fly ash transport and
disposal systems. Such systems of transport carry fly ash collected
in precipitators to short-term storage vessels (silos) by vacuum or
pressurized air. No water is used in the transport. The ash in the
silos is trucked to landfill disposal sites.
A number of these facilities retrofitted their systems—that is, they
replaced wet sluicing to ponds with the dry transport systems. This
method of handling fly ash eliminates the discharge of all ash sluice
water and thus eliminates priority pollutant discharge.
The motivation for retrofitting dry fly ash systems for these
facilities may be the result of a water shortage in the area, state or
local requirements, or a plant's desire to market the fly ash.
b« Partial recirculation of fly ash sluice water
Currently 52 percent of coal fired plants and 10 percent of oil fired
plants wet sluice -their fly ash to a disposal pond. This method
carries ash from the fly ash hoppers to a settling pond or basin using
water as the transport medium. Most plants operate in a once-through
mode since they do not pump any of the ash water back to be reused.
Of the plants wet sluicing fly ash, 9 percent of coal-fired plants
partially recirculate the sluice water. The sluiced ash is commonly
pumped to settling ponds and then flows to a clear pond where water is
recirculated to the main sluice pumps. In partially recirculating
systems, a portion of the clear pond overflow is discharged.
Theoretically, partial recirculation reduces the flow of ash transport
discharge and therefore the mass rate of discharge for priority
pollutants; however, data to quantify the degree of toxic reduction
are not available at the present time.
Essentially no major equipment need be removed in order to retrofit a
partially recirculating system from a wet once-through system, other
than the rerouting of old pipe. The addition of recirculation pumps
464
-------
to move the pond water, and a recirculation pond are required. The
technology is in use today at some facilities and is available to all
plants. The degree of water recycle/reuse practiced by existing
facilities with recirculating systems varies. The Agency has not
identified any plants with complete recirculation (no blowdown or
point source discharge).
c. Chemical precipitation
Another available technology option is chemical precipitation of the
final discharge from the partially recycled ash sluice water.
Chemical precipitation, in particular lime precipitation, has been
demonstrated over many years as an effective method of removing heavy
metals from aqueous solutions. The Agency has data to quantify
arsenic removal to 50 ppb although the removal of other inorganic
priority pollutants was also studied. The Agency has demonstrated the
effectiveness of lime precipitation for reducing levels of metals in
fly ash pond effluents in bench scale tests.
The Agency's data base indicates that approximately 10 percent of the
plants discharging fly ash sluice water will have high levels of
dissolved arsenic (exceeding .05 mg/1),
4. Proposed Regulation
a. BAT
The Agency is not proposing any additional controls for fly ash
transport water beyond those established by BPT at this time. This
decision is the result of careful consideration of factors including
costs, treatment technology! availability, quantity of pollutants
removed, and other factors. The ash ponds generally used to achieve
BPT limits already produce substantial reductions in the amounts of
toxic pollutants discharged from fly ash transport water.
EPA seriously considered proposing a no-discharge limitation for all
plants larger than 200 MW based upon dry fly ash -transport. While EPA
found this option to be technologically feasible.for these plants, EPA
has concluded that; the extremely high costs to the industry ($3.19
billion in capital costs for 1980-1985) could not be justified in view
of the inconclusive nature of the available data regarding the degree
of toxic pollutant reduction to be achieved beyond BPT. EPA does not
feel that it would be responsible to impose such costly additional
requirements in the face of such uncertainity.. Currently, 169 out of
the 352 existing coal-fired plants already use dry methods of
transport. EPA's decision is not based upon consideration of water
quality impacts. The decision is based soley on the inconclusive
nature of the data regarding the degree of effluent reduction that
would be achieved.
Another option to eliminate discharge is through complete
recirculation of ash transport water. However, the information
465
-------
available to the Agency at this time is not sufficient to determine if
this system is technically achievable.
The Agency rejected partial recirculation (with blowdown) because data
are not available at this time to support a specific numerical
effluent limitation for any toxic pollutant; nor can the Agency
conclude at this time that any non-toxic pollutant parameter (such as
TSS) could serve as an "indicator" for toxic control from partial
recirculation. In addition, more stringent limitations for
conventional pollutions based on partial recirculation are not imposed
because the cost will not pass the cost reasonableness test for Best
Conventional Technology.
Precipitation has been explored as a technology option for inorganic
priority pollutant removal from ash pond overflows. Precipitation is
rejected because the mean concentrations of most of the inorganic
pollutants from the untreated ash ponds overflow are less than the
treated levels through precipitation from other industrial plants, and
thus no technology transfer can be made. The Agency conducted a pilot
study and determined that precipitation can remove inorganic
pollutants from ash pond overflows; but the data are not sufficient to
specify the removal level achievable at a full scale plant.
Precipitation is an option for treating arsenic at certain plants with
high levels of arsenic. Existing data are available to specify a
removal level for arsenic of 0.05 mg/1. This level is estimated to be
exceeded by 10 percent of the coal-fired facilities. Although the
precipitation technology option was not selected for proposal, it,
together with the dry fly ash transport requirements will be seriously
considered as an alternative BAT option in the future.
EPA has decided not to propose further control of fly ash transport
water beyond BPT for existing sources at this time because the
available data does not support the need for further control EPA is
considering further sampling and industry profile studies that might
allow the Agency to reasses its position. The Agency is publishing
all available data and requesting public comment on how a program for
further sampling and analyses might be conducted.
b. NSPS and PSNS
The proposed NSPS and PSNS prohibits all discharges of fly ash water.
In light of the large number of plants already uisng dry fly ash
systems, the technology is clearly demonstrated and available. Unlike
BAT, the costs for a dry fly ash handling system are not appreciably
different than costs for wet sluicing fly ash in a new plant. All new
sources regardless of size are prohibited from discharging fly ash
water. The Agency does not anticipate any of the new sources to
discharge their fly ash. transport water to POTWs.
c. PSES
466
-------
For PSES, EPA is proposing no additional control beyond existing PSES.
This is equivalent to no control.
D. Bottom Ash Transport Water
1 • Pollutants detected ir\ sampling program
Similar pollutants were detected in bottom ash transport water and fly
ash transport water but the concentrations detected in bottom ash
sluice water discharges were typically lower. Moreover, in comparison
to the fly ash sampling data, the data on bottom ash water discharge
displays a more consistent pattern of lower concentrations in the
effluent than in the intake water. This is because the surface area
of ash/unit weight available for leaching is greater for fly ash than
bottom ash. Further, certain pollutants with low volatility
temperature would be present in the bottom ash at very low
concentrations (i.e., arsenic, mercury, etc.).
At most plants sampled, the concentrations of priority inorganic
pollutants detected in the bottom ash pond were less than the
concentrations detected in .the raw or intake water source. The bottom
ash data are still somewhat inconclusive due to small sample size and
large variability. The pollutants detected in bottom ash transport
water are summarized in Table VI-1 of Section VI.
2.. Need to control toxics from this stream
The following priority inorganic pollutants were detected at least
once in bottom ash effluent in the EPA sampling data base: antimony,
nickel, arsenic, lead, beryllium, chromium, copper, cadmium, mercury,
selenium, and zinc. In most cases, however, the observed effluent
concentrations of these pollutants are smaller thand the intake water
concentrations. Thus, the need to control toxic pollutants from this
waste stream beyond BPT is warranted on the basis of the sampling data
now available to. the Agency.
3. Available technologies and techniques
(a) dry transport —
Approximately 70 plants currently transport their bottom ash using a;
dry system and report no discharge to the navigable waters. Dry
transport of bottom ash entails the mechanical removal of the bottom
ash from the bottom ash bin and mechanical transport (conveyor type)
to a temporary storage vessel. The ash from the temporary storage
vessel is transported by truck to the permanent disposal site. No
water is required in this transport system. Dry handling of bottom
ash is typical of plants with stoker-fired boilers. These plants
usually have small capacities, with relatively small amounts of bottom
ash generated.
467
-------
(b) partial to complete recirculation --
Many plants recirculate their bottom ash transport water with a
blowdown stream to control the buildup of dissolved solids. A
completely recirculating system returns all of the ash sluice water to
the ash collecting hoppers for repeated use in sluicing. A
recirculating system can be operated at partial recirculation, usually
12.5 or 25 times recycle, or operated with a complete recycle of
bottom ash sluice water. The Agency has not identified any plants
with complete recirculation except those in arid areas using
evaporation ponds to eliminate final discharge.
(c) precipi_tation .—
This is the same treatment method as discussed in part 3(c) of the f.ly
ash section.
4. Proposed Regulation
(a) BAT
No further control beyond BPT is proposed. The Agency has considered
the above options and determined that in view of the waste
characteristics and costs of control options, adequate control methods
are imposed under BPT for this waste stream.
Dry transport of bottom ash for all plants is rejected because this
technology is known to be adequate for handling only small amounts of
bottom ash. The Agency does not believe that this technology is
economically feasible and technically available on a national basis.
The Agency seriously considered the options of partial to complete
recirculation of bottom ash sluice water. Although complete
recirculation is concluded to be a technically feasible option,
although the Agency is not proposing it. The high costs, and the fact
that the data to quantify the effluent reduction beyond BPT are
inadequate, are the two major reasons for .not selecting this option.
The Agency may gather additional information on this waste source
(through the sampling program discussed above) and the Agency's
positon may be reassessed upon review of the new information.
The Agency is proposing the withdrawal of the current BAT requirement
of 12.5 recycle of bottom ash sluice water based on the removal of
conventional pollutants because the "reasonableness" of this option
using the cost tests for conventional pollutants in 40 CFR Part 405
(August 23, 1978) was assessed and for all plant sizes, the 12.5
recycle option did not pass the BCT test.
Precipitation is rejected because the effectiveness of this technology
in bottom ash wastewater is uncertain. The mean concentrations of the
inorganic priority pollutants are lower than the treated levels from
other industries using this technology, and thus a technology transfer
cannot be established. Bench scale studies applying this technology
468
-------
to ash pond effluents indicate effective removal of certain trace
metals, but more studies are necessary to confirm these results,, .
(b) NSPS
For, the same reasons that EPA is not proposing any requirements beyond
BPT for existing sources, EPA is proposing to withdraw the current
NSPS requirement of 20 times recycle and substitute the basic BPT
requirement in its place. Unlike dry fly ash handling systems for new
sources (which are no more costly than other fly as handling systems)
a recycle system for bottom ash is substantially more expensive than
other bottom ash handling systems.
(c) PSES and PSNS
The proposed PSES and PSNS do not restrict the discharge of any
pollutants from this wastewater source. The costs of controlling
priority inorganic pollutants and the low levels of pollutants
detected do not warrant the imposition of effluent standards for this
waste stream at this time.
E.' Metal Cleaning Wastes
This document supercedes all previous memoranda on effluent limi-
tations guidelines regarding the definition of.metal cleaning wastes.
Metal cleaning wastes include boiler tube cleaning waste, air
preheater wash water and fireside wash water, with or without the use
of chemicals during the cleaning process.
The limitations for iron and copper of 1 mg/1 will not be changed.
For those cases where chelating or complexing agents are used in the
cleaning process, the treatment technology scheme may need to be
altered. Lime treatment of these chelated wastes, together with air
preheater and fireside wash water (at the proper ratio), will result
in the achievement of the 1.0 mg/1 limitation. An alternate
precipitation scheme using sulfide will also achieve the 1.0. mg/1
limit.
F. Low-Volume Wastes
The best practicable technology currently available is found to be
adequate for control and is being defined as best available technology
economically achievable. Boiler blowdown, which is currently
considered as a separate waste category, is required to be treated for
iron and copper. In reexamination of the waste characteristics
information, boiler blowdown is now redefined as low-volume waste and,
therefore, is no longer subject to the iron and copper limitations.
Application of. Effluent Limitations Guidelines and SJbandards
A discussion of the application of the effluent limitations guidelines
was presented in the 1974 Development Document (1). Certain aspects
relating to the implementation of the original guidelines and
469
-------
recommended revisions are discussed below. In-plant dilution is
permitted to achieve pH limitations. Consolidation of waste streams
to a centralized treatment .system is permitted and encouraged. The
quantity of pollutant permitted to be discharged, however, is not
always equal to the total flow times the effluent limitations
guidelines. It would equal the effluent limitations guidelines times
total flow only if all the raw waste streams contributing to the
central treatment system have waste characteristics which exceed the
guidelines. For cases where the dilution ratio would be so great that
the analytical method is not accurate enough to distinguish the
difference (such as low volume wastes containing oil and grease
exceeding 15 mg/1 are discharged to ash ponds)t monitoring at the
point prior to mixing (or dilution) would be required. The same
analogy can be used for any stream and any pollutant.
470
-------
SECTION X
Ji. ACKNOWLEDGEMENTS
Many individuals representing numerous agencies, institutes,
organizations, universities, companies, and corporations have
contributed material, time and energy to the production of this
document. Because of the large number of individual contributors,
only the organizations they represented will be mentioned.
This document was prepared under the direction of John Lum of the
Energy and Mining Branch of the Effluent Guidelines Division of the
EPA. Assisting Mr. Lum were Ms. Barbara Menking (EGD) and Ms. Teresa
Wright (EGD). Dr. William A. Telliard, Branch Chief of the Energy and
Mining Branch, also provided direction and assistance during the
course of the study.
This version of the development document was developed and written by
Radian Corporation, McLean, Virginia. An earlier version of this
document (September 1978) was developed and written by the
Environmental Engineering Department of Hittman Associates, Columbia,
Maryland. Much of the information developed by Hittman Associates was
incorporated into this draft. Material was also drawn from the
Development Document for the original BAT guidelines written by Burns
and Roe in 1974.
The following acknowledgements for cooperation, assistance, data,
advice, etc., are organized by type of organization.
Agencies—The following agencies and divisions of agencies contributed
to the development of this document.
EPA - 1. All the regional offices
2. Industrial and Environmental Research Labs—
Research Triangle Park
3. Industrial and Environmental Research Labs—
Corvallis, Oregon
4. Office of Research and Development
5. Office of General Council
6. Office of Planning and Evaluation
7. Office of Enforcement
8. Office of Analyses and Evaluation
9. Monitoring and Data Support
10. Criteria and Standards Division
11. Office of Solid Wastes
12. Environmental Monitoring and Support
13. Environmental Research Lab—Duluth, Minnesota
14. Office of Pesticide Program
Federal Power Commission
Nuclear Regulatory Commission
Oak Ridge National Laboratories
471
-------
Several institutes and organizations, primarily representing the
interests of the industry, were very helpful in providing data and
various forms of technical assistance. These were:
Cooling Tower Institutes
Edison Electric Institute
Gulf South Research Institute
Utility Water Act Group (UWAG)
Two state agencies, the State of California Resources Agency and the
Michigan Department of Natural Resources, provided data and assistance
to this effort. The University of Delaware is acknowledged for their
assistance and data contributions.
Many private companies, primarily vendors doing business for electric
utility companies, were helpful in providing equipment costs,
engineering data and other assistance. These were (in alphabetical
order):
Allen Sherman Hoff Company
Amertap Corporation
ANDCO
Betz Laboratories
Carborundum
Dow Chemical Company
Drew Chemical Corporation
Ecodyne
INCRA
Lockheed
Mogul Corporation
01in Brass
Research Cottrell
Richardson
Tetratech, Inc.
TRW
United Conveyor
Many electric power companies were very cooperative in providing
access to steam electric plants for various sampling and engineering
studies, Many were also very cooperative in sharing data and other
information on their facilities. Of particular assistance were {in
alphabetical order):
American Electric Power
Appalachian Power Company
Arizona Public Service Company
Boston Edison
Cincinnati Gas & Electric Company
Colorado-Ute Power Company
Commonwealth Edison
Consumer Power Company
Delmarva Power Company
Georgia Power Company
472
-------
Gulf Power Company
Long Island Lighting
Natural Rural Electric
Nevada Power Company
Northern States Power Company
Pacific Power and Light
Pennsylvania Power and Light Company
Public Service Electric & Gas
Southern California Edison
Tampa Electric Company
Tennessee Valley Authority
Utah Power and Light
Wisconsin Electric Power Company
473
-------
474
-------
SECTION XI
REFERENCES
SECTION III"
1. "Development Document for Effluent Limitations Guidelines
and New Source Performance Standards for the Steam Electric
Power Generating Point Source Category," U.S. Environmental
Protection Agency, EPA-4401/l-74-029-a, October 1974.
2. Telliard, William A., "Rationale for the Development of BAT
Priority Pollutant Parameters," U.S. Environmental
Protection Agency, May 24, 1977.
3. Natural Resources Defense Council, et al. v. Train,
8 E.R.C. 2120-2136 (D.C.D.C. 1976).
4. Appalachian Power Company, et al., v. Train, 9 E.R.C.
1033-1056 (C.A.D.C. 1976).
5. "Standard Industrial Classification Manual," U.S. Office of
Management and Budget, Washington, D.C., 1972.
6. "The Clean Water Act, Showing Changes Made by the 1977
Amendments and the 1978 Amendments to Sections 104 and
311," (33 U.S.C. 466 et seq.), 96th Congress, 1st Session,
U.S. GPO, Washington, D.C., 1979.
7. "Sampling and Analysis Procedures for Screening of Indus-
trial Effluents for Priority Pollutants," U.S. Environmental
Protection Agency, April 1977.
8. "Draft Economic Analysis for the Proposed Revision of
Steam Electric Utility Industry Effluent Limitations
Guidelines," U.S. Environmental Protection Agency,
prepared by Temple, Barker, and Sloane, Inc., Lexington,
Mass., August, 1980.
9 "Inventory of Power Plants in the United States - April
1979", U.S. Department of Energy, Energy Information Adminis-
tration, DOE/EIA - 0095(79), DIST CAT. UC - 97, U.S. Govern-
ment Printing Office, Washington, D.C., 20402.
10. "Electric Utility Statistics" Public Power, Vol. 34, No.
1, pp. 32-74, 1976.
SECTION IV
1. "Development Document for Effluent.Limitations Guidelines
and New Source Performance Standards for the Steam Electric
Power Generating Point Source Category," U.S. Environmental
Protection Agency, EPA-4401/.l-74-029-a, October 1974.
475
-------
SECTION V
1. "Development Document for Effluent Limitations Guidelines
and New Source Performance Standards for the Steam Electric
Power Generating Point Source Category," U.S. Environmental
Protection Agency, EPA-4401/l-74-029-a, October 1974.
2. "Sampling and Analysis Procedures for Screening of Indus-
trial Effluents for Priority Pollutants," U.S. Environmental
Protection Agency, April 1977.
3. White, George C., "Handbook of Chlorination: for Potable
Water, Wastewater, Cooling Water, Industrial Processes, and
Swimming Pools", Van Nostrand Reinhold Company, NY, 1972.
4. Lewis, Barbara-Ann G., "Asbestos in Cooling-Tower Waters,"
Argonne National Laboratory, Argonne, IL, December 1977.
5. Warner, M. E. and M. R. Lefevre, "Salt Water Natural Draft
Cooling Tower Design Considerations," presented at the
American Power Conference, Chicago, IL, April 1974.
6. Haggerty, D., and M. Lefevre, "The Growing Role of Natural
Draft Cooling Towers in U.S. Power Plants," Power
Engineering, Vol. 80, No. 6, pp. 60-63, 1976.
7. Jolley, Robert L., et al., "Chlorination of Organics in
Cooling Waters and Process Effluents," Proceedings of the
Conference on the Environmental Impact of Water Chlorina-
tion, October 22-24, 1975.
8. Stevens, Alan A., et ai., "Chlorination of Organics in
Drinking Water," Proceedings of the Conference on the
Environmental Impact of Water Chlorination, October 22-24,
1975.
9. Morris, J. Carrell and B. Baum, "Precursors and Mechanisms
of Haloform Formation in the Chlorination of Water
Supplies," Harvard University, Cambridge, MA, undated.
10. Hubbs, S. A., et al., "Trihalomethane Reduction at the
Louisville Water Company," Louisville Water Company,
Louisville, KY, undated.
11. Bean, Roger, M., R. G. Riley and P. W. Ryan, "Investigation
of Halogenated Components Formed from Chlorination of
Estuarine Water," presented at the Conference on Water
Chlorination: Environmental Impact and Health Effects,
Gatlinburg, TN, October 31-November 4, 1977.
12. Carpenter, James H. and C. A. Smith, "Reactions in
Chlorinated Seawater," Water Chlorination: Environmental
476
-------
Impact and Health Effects, Ann Arbor Science Publishers,
Inc., Ann Arbor, Michigan, 1978.;
13. "Principles of Industrial Water Treatment," Second Edition,
Drew Chemical Corporation, Boonton, NJ, 1978.
14. Alexander, James E. , "Copper and Nickel Pickup in the Cir-
culating Water Systems at Northport," New York Ocean Science
Laboratory, Montauk, NY, March 1973.
15. Popplewell, James M. and S. F. Hager, "Corrosion of Copper
Alloys in Recirculating Cooling Tower Systems and its Effect
on Copper in the Effluent," presented at the National
Association of Corrosion Engineers Conference, San
Francisco, CA, March 14-18, 1977.
16. Young, David R. , et al., "Trace Metals in Coastal Power
Plant Effluents," Southern California Coastal Water Research
Project, El Segundo, CA, undated.
17. Weidman, Jay G., Water Treatment Committee, Cooling Tower
Institute, letter to John Lum, U.S. Environmental Protection
Agency, April 6, 1977.
18. "Steam: Its Generation and Use," 39th Edition, Babcock &
Wilcox Company, New York, NY, 1978.
19. "Ash Handling Systems and Suspended Solids in Ash Ponds,"
U.S. Environmental Protection Agency, prepared by Hittman
Associates, Inc., Contract No. 68-01-4894, December 1978.
20. Cox, Doye B., et al., "Characterization of Coal Pile Drain-
age," U.S. Environmental Protection Agency,
EPA-600/7-79-051, prepared by Tennessee Valley Authority,
February 1979.
21. Curtis, Robert, "Ash Handling File," Radian Corporation,
McLean, VA, November 1979.
22. Miller, F. A., T. Y. J. Chu and R. J. Ruane, "Design of Mon-
itoring Program for Ash Pond Effluents," U.S. Environmental
Protection Agency, prepared by Tennessee Valley Authority,
EPA-IAG-D8-E721, undated.
23. NUS Corporation, "Treatability of Ash Settling Pond
Effluents," Pittsburgh,, PA, March 1979.
24. "Field Testing and Laboratory Studies for the Development of
Effluent Standards for the Steam Electric Power Industry,"
U.S. Environmental Protection Agency, prepared by Radian
Corporation, Contract No. 68-02-2608, August 1978.
25. "Pollution Control Technology for Fossil Fuel-Fired Electric
477
-------
Generating Stations, Section 3, Water Pollution Control,"
U.S. Environmental Protection Agency, prepared by Radian
Corporation, Contract No. 68-02-2008, March 1975^
26. California Regional Water Quality Control Board, Santa Ana
Region, "Variance from Effluent Guidelines Limitations for
Steam Electric Power Generating Point Source Category,"
transmittal of August 12, 1976.
27. Rice, James K. and Sheldon D. Strauss, "Water Pollution
Control in Steam Plants," Power, Vol. 120, No. 4, April
1977.
28. Halliburton Services, "Hydrochloric Acid Cleaning Service,"
Technical Data Sheet IC-12000(Rev), Duncan, Oklahoma.
29. Engle, J. P., "Cleaning Boiler Tubes Chemically," Chemical
Engineering, Vol. 18, pp. 154-158, 1971.
30. Greenburg, S., "Factors That Must Be Considered for Suc-
cessful Chemical Cleaning as Experienced in Naval Boilers,"
Proceedings of the American Power Conference, Vol. 28, pp. '
818-829, 1966.
31. Halliburton Services, "CurtainMI Complexing Agent,"
Technical Data Sheet IC-12022(Rev), Duncan, Oklahoma.
32. "Handbook of Industrial Water Conditioning," Seventh
Edition, Betz Laboratories, Trevose, PA, 1976.
33. Ellis, H. J., Public Service Company of New Hampshire,
letter to Edward J. Conley, U.S. Environmental Protection
Agency, Boston, MA, August 21, 1973.
34. Klein, H. A., J. J. Kurpen and W. G. Schuetzenduebel, "Cycle
Cleanup for Supercritical Pressure Units/" Proceedings of
the American Power Conference, Vol. 27, pp. 756-773, 1965.
35. Halliburton Services, "The Citrosolv Process," Technical
Data Sheet IC-12005(Rev.), Duncan, Oklahoma.
36. Flynn, James P., Dow Industrial Service, letter to K. G.
Sudden, Hittman Associates, Inc., February 7, 1977.
37. Haller, W.A., et al., "Duke Power Company Ash Basin Equiva-
lency Demonstration for Metal Cleaning Wastes," Proceedings
of the American Power Conference, Vol. 39, pp. 868-874,
1977.
38. Halliburton Services, "Hydroxyacetic/Formic Acid," Technical
Data Sheet IC-12009{Rev), Duncan, Oklahoma.
39. Reich, C. F. and D. B. Carroll, "A New Low Chloride
478
-------
Inhibitor and Copper Complexing Agent for Sulfuric Acid
Cleaning Solutions," Proceedings of the American Power
Conference, Vol. 27, pp. 784-789, 1965.
40. Engle, J. P., "Chemical Cleaning of Feedwater Heaters,"
Paper No. 104, presented at the Corrosin Forum, Chicago, IL,
March 4-8, 1974.
41. Woldman, N. E., and R. C. Gibbons, eds., "Engineering
Alloys," Fifth Edition, Van Nostrand Reinhold Company, New
York, 1973.
42. Strumm, W., and J. J. Morgan, "Aquatic Chemistry: An Intro-
duction Emphasizing Chemical Equilibria in Natural Waters,"
Wiley-Interscience, John Wiley & Sons, Inc., New York, 1970.
43. Ellis, H. J., Public Service Company of New Hampshire,
letter to Edward Conley, U.S. Environmental Protection
Agency, Boston, MA, August 21, 1973.
44. Cox, Doye B., and R. J. Ruane, "Characterization of Coal
Pile Drainage," Tennessee Valley Authority,
EPA-IAG-D5-E-721, undated.
45. Anderson, William C., and Mark P. Youngstrom, "Coal Pile
Leachate-*-Quantity and Quality Characteristics, " ASCE,
Journal of Environmental Engineering Division, Vol. 102,
No. EE6, pp. 1239-1253, 1976.
46. Cox, Doye B., and R. J. Ruane, "Coal Pile Drainage,"
Tennessee Valley Authority, semi-annual progress report,
July-December 1976.
47. Flora, H. B,, Ph.D. (TN Valley Authority) to M. C. Osborne,
EPA, RTP, NC. re: Chlorinated organics study, once-through
cooling system, letter. Chattanooga, TN, 4/24/79.
48. 'Hittman Associates, Inc. Boiler Chemical Cleaning Prelimin-
ary Draft Report, (EPA Contract No. 68-01-3501), Columbia
Maryland, July 1977.
49. Gregory, N., et al., "EPA Utility FGD Survey: February-March 1978,"
PEDCo Environmental, Inc., Cincinnati, OH, EPA
Contract No. 67-01-4147, EPA 600/7-78-0516, June 1978.
50. Chu, T. J., R. J. Ruane and G. R. Steiner, "Characteristics
of Wastewater Discharges from Coal-fired Power Plants,"
paper presented"at the 31st annual Purdue Industrial Waste
Conference, West Lafayette, IN, May 1976.
51. Sugarek, R. L. and T. G. Sipes, "Water Pollution Impact of
Controlling Sulfur Dioxide Emissions from Coal-fired Steam
Electric Generators," draft report, Radian Corporation,
479
-------
Austin, TX, EPA Contract No. 68-02-2608, October 1977.
52. Leo, P. P. and J. Rossoff, "The Solid Waste Impact of
Controlling S02 Emissions from Coal-Fired Steam
Generators," Vol. 2-Technical Discussion, Aerospace
Corporation, El Segundo, CA, EPA Contract No. 68-01-3528,
October 1977.
53. Fling, R. B., et al., "Disposal of Flue Gas Cleaning Wastes:
EPA Shawnee Field Evaluation," Aerospace Corporation, Los
Angeles, CA, EPA-ORD Contract No. 68-02-1010, EPA
600/2-76-070, March 1976.
SECTION VI
1. "The Clean Water Act, Showing Changes Made by the 1977
Amendments and the 1978 Amendments to Sections 104 and 311,"
(33 U.S.C. 466 et seq.), 96th Congress, 1st Session, U.S.
GPO, Washington, D.C., 1979.
2. "Development Document for Effluent Limitations Guidelines
and New Source Performance Standards for the Steam Electric
Power Generating Point Source Category," U.S. Environmental
Protection Agency, EPA-4401/l-74-029-a, October 1974.
3. "Guidelines Establishing Test Procedures for the Analysis of
Pollutants," Federal Register, Vol. 38, No. 199, pp.
28758-28760, October 16, 1973.
4. Paterson, Robert, "Corrosion and Scaling Control File: A Set
of Notes and Phone Call Memos on Corrosion and Scaling Con-
trol," Radian Corporation, McLean, VA, August-November 1979.
5. Paterson, Robert, "Non-Oxidizing Biocides File: A Set of
Notes, Calculations and Vendor Contact Reports Concerning the
Use of Non-Oxidizing Biocides," Radian Corporation, McLean,
VA, August-November 1979.
SECTION VII
1. White, George C., "Handbook of Chlorination: for Potable
Water, Wastewater, Cooling Water, Industrial Processes, and
Swimming Pools," Van Nostrand Reinhold Company, NY, 1972.
2, Ward, Daniel, "Chlorination, Chlorination-Alternatives File:
A Set of Notes and Calculations Describing Cost Estimates,"
Radian Corporation, McLean, VA, October 1979.
3. Schumacher, P. D., and J. W. Lingle, "Chlorine Minimization
Studies at the Valley and Oak Creek Power Plants," presented
at the Condenser Biofouling Control Symposium, Altanta, GA,
March 1979.
480
-------
4. Rice, James K., "Chlorine Minimization Plan for Comanche
Peak Steam Electric Station, Texas Utilities Generating
Company, NPDES Permit TX0065854," Olney, MD, March=1979.
5. Rice, James K., "Chlorine Minimization: An Overview,"
Olney, MD, undated.
6. Philadelphia Electric Company, "Condenser Chlorination Study
- 1977/1978," Philadelphia, PA, October 1978.
7. Moss, Robert, et al., "Chlorine Minimization/Optimization at
one TVA Steam Plant," Tennessee Valley Authority,
Chattanooga, TN, 1978.
8. Commonwealth Edison, "Chlorine Reduction Studies," Chicago,
IL, December 1976.
9. American Electric Power Service Corporation, "Indiana-
Kentucky Electric Corporation, Clifty Creek Station:
Chlorine Study Report," Vols. 1 and 2, Canton, OH, June
1978.
10. Duquesne Light Company, "Shippingport Atomic Power Station,
NPDES Permit No. PA 0001589: Chlorine Reduction Study,"
Pittsburg, PA, December 1978.
11. Lehr, John, "Summary Report on Chlorination Practices and
Controls at Operating U.S. Nuclear Power Plants," Draft
Report, United States.Nuclear Regulatory Commission,
Washington, D.C., May 1978.
12. Bernt, D. S. and K. H. Nordstrom, "Chlorine Reduction Study:
High Bridge Generating Plant," Northern States Power
Company, Minneapolis, MN, June 1978.
13. Bernt, D. S., "Chlorine Reduction Study: Monticello
Generating Plant," Northern States Power Company,
Minneapolis, MN, June 1978.
14. American Public Health Association, et al., "Standard
Methods for the Examination of Water and Wastewater,"
Thirteenth Edition, APHA, AWWA, and WPCF, New York, 1971.
15. Betz Environmental Engineers, Inc., "Dechlorination,"
undated.
16. "Chlorination of Wastewater—Manual of Practice No. 4,"
Water Pollution Control Federation, Washington, D.C., 1976.
17. White, George C., "Chlorination and Dechlorination: A
Scientific and Practical Approach," Journal AWWA, Vol. 60,
No. 5, pp. 540-555, May 1968.
481
-------
18. Scheyer, K. and G. Houser, "Evaluation of Dechlorination for
»Total Residual Oxidants Removal," TRW, Inc., Redondo Beach,
CA, Contract No. 68-02-2613, November 1979.
19. Schumacher, P. D., "Test Results for Chemical Dechlorination
Studies at the Valley Power Plant," Wisconsin Electric Power
Company, Milwaukee, Wisconsin, June 1977.
20. Pacific Gas and Electric Company, "Data and Letters
Describing the Process of Dechlorination by Natural Chlorine
Demand in a Recirculating Cooling Water System at California
Power Plant," Transmitted to the California Regional Water
Quality Control Board, Oakland, CA, June 20, 1977.
21. Gray, Harry J., and A. W. Speirs, "Chlorine Dioxide Use in
Cooling Systems Using Sewage Effluent as Make-Up," presented
at the Cooling Tower Institute Annual Meeting, Houston,
Texas, January 23-25, 1978.
22. Yu, H. H. S., G. A. Richardson and W. H. Hedley, "Alterna-
tivees to Chlorination for Control of Condenser Tube
Biofouling", Monsanto Research Corporation, Dayton, OH, EPA
600/7-77-030, March 1977.
23 Ward, Daniel, "Chlorination, Chlorination-Alternatives File:
A set of Notes and Calculations Describing ST Estimates,"
Radian Corporation, McLean, VA, October 1979.
24. Mills, Jack F., "Bromine Chloride, an Alternative to
Chlorine for Trtatment of Once-through Cooling Waters,"
presented at the Electric Power Research Institute Condenser
Biofouling Control Symposium, Atlanta, GA, March 1979.
25 Bongers, Leonard H., et al., "Bromine Chloride—An Alterna-
tive Biofouling Control Agent for Cooling Water Treatment",
presented at the Conference on Water Chlorination:
Environmental Impact and Health Effects, Gatlinburg, TN,
October 31-Noyember 4, 1977.
26. Burton, D.T., and S.L. Margrey, "Control of Fouling
Organisms in Estuarine Cooling Water Systems by Chlorine and
Bromine Chloride," Environmental Science & Technology, Vol.
13, No. 6, pp. 684-689, June 1979.
27. Wackenhuth, E. C., and G. Levine, "Experience in the Use of
Bromine Chloride for Antifouling at Steam Electric Genera-
ting Stations," Biofoulinq Control Procedures, Pollution
Engineering and Technology, Vol. 5, Marcel Dekker, Inc., New
York, 1977.
28. Union Carbide Corporation, "Ozonation Systems, Oxygen
Production and Supply," "Ozonation Systems," and "LG Model
Ozone Generators," pamphlets, New York, New York.
482
-------
29. Ozone Research & Equipment Corporation, "Ozonators;
Industrial, Municipal, Process, Laboratory," Phoenix, hi,
undated,
30. Woodbridge, D. D., "Alternatives to Chlorination in Electric
Power Plants," Hittman Associates, Inc., Columbia, MD, Con-
tract No. 68-01-4894, undated.
31. "Point Source Water Control Monitoring (sampling) Data
Collection and Identification," Hittman Associates, Inc.,
Columbia,.MD, Contract No. 68-01-3501, Progress Report,
October 1977.
32. Paterson, Robert, "Corrosion and Scaling Control Files A
Set of Notes, Phone Call Memos on Corrosion and Scaling Con--
trol," Radian Corporation, McLean, VA, August-November 1979.
33. Paterson, Robert, "Non-Oxidizing Biocides,; File: A Set of
Notes, Calculations and Vendor Contract Reports Concerning
the Use of Non-Oxidizing Biocides," Radian Corporation,
McLean, VA, August-November 1979.
34. Weidman, Jay G., Cooling Tower Institute, letter to-John
Lum, U.S. Environmental Protection Agency, February 2, 1977.
»!>*- *•<
35. Sipp, J. R. and J. R. Townsend, "Improving Condenser
Cleanliness by Using a Dispersant to Supplement Chlorination
at a Nuclear Power Plant," Presented at the Cooling Tower
Institute Annual Meeting, January 23-25, ,1978.
36. Allen-Sherman-Hoff Company, "A Primer on; Ash Handling Sys-
tems," Malvern, PA, 1976.
37. Morrison, Ronald E., "Powerplants Ash; A New Mineral Re-
source," presented at the Fourth International Ash Utiliza-
tion Symposium, St. Louis, Missouri, March 24-25, 1976.
38. "Utilities Cash in on Fly Ash," Electrical World, Vol. 185,
No. 9, pp. 23-24, May 1, 1976.
39. Curtis, Robert, "Ash Handling File: A^ Sjet of Notes and
Calculations Describing the Costs Submitted to Temple,
Barker and Sloane," Radian Corporation, McLean, VA, October
1979.
40. Allen-Sherman-Hoff Company, "A Primer on Ash Handling Sys-
tems," Malvern, PA, 1976. i
41. "Process Design Manual for Suspended Solids Removal," D.S.
Environmental Protection Agency, EPA 625/l-75-003a, January
1975.. ' ' • v'; . •
483
-------
42. "Process Design Manual for Sludge Treatment Disposal," U.S.
Environmental Protection Agency, EPA 625/1-74-006, October
1974.
43. Gulp, Russell L., G. M. Wesner, and G. L. Gulp, "Handbook of
Advanced Wastewater Treatment," Second Edition, Van Nostirand
Reinhold Company, New Yor, 1978.
44. Sorg, Thomas J., and G. S-. Logsdon, "Treatment Technology to
Meet the Interim Primary Drinking Water Regulations for
Inorganics: Part 2," Journal American Water Works Associa-
tion, pp. 379-392, July 1978.
45. Patterson, James W., "Wastewater Treatment Technology," Ann
Arbor Science Publishers Inc., Ann Arbor, Michigan, 1975.
46. "Development Document for Effluent Limitations Guidelines
and New Source Performance Standards for the Steam Electric
Power Generating Point Source Category," U.S. Environmental
Protection Agency, EPA-4401/l-74/029~a, October 1974.
47. Scott, M. C./•"'"•Sulfide Process Removes Metals, Produces
Disposable Sludge," Industrial Wastes, pp. 34-39,
July/August 1979.
48. "Field Testing and Laboratory Studies for the Development of
Effluent Standards for the Steam Electric Power Industry,"
U.S. Environmental Protection Agency, prepared by Radian
Corporation, Contract No. 68-02-2608, August 1978.
49. Colley, j.-pi^'ft al., "Assessment of Technology for Control
of Toxic Effluents From the Electric Utility Industry,"
prepared by"Radian Corporation for U.S. Environmental
Protection Agency, Contract No. 68-02-2608, December 1977.
50. Resources Conservation Company, "Brine Concentration,"
Renton, WA,mundated.
51. Springer, Wayne E., Resources Conservation Company, letter
to Thomas Emmel,Radian Corporation, August 14, 1979.
" '• y dai* "'
52. "Scale-Free Vapor Compression Evaporation," U.S. Department
of the Interior, Washington, D.C., undated.
53. Wackenhuth, E.'C., L. W. Lamb and J. P. Engle, Use and Dis-
posal of Boiler Cleaning Solvent, Pov/er Engineering,
November 1973y: *
54. Jones, C. Wv, G. W. Lewis and L. D. Martin, Disposal of
Waste Ammoniacai Bromate and Ammonium Bifluoride Solutions
by Evaporation, presented at the 37th Annual Meeting Inter-
nations Water Conference, Pittsburg, PA, October 26-28,
1976.
484
-------
55. O'Neal, A, J., H, Cowmerd and D. J. Hassebroek, Experimental
Incineration of Boiler Internal Cleaning Solvent at Long
Island Lighting Company, Combustion, October 1976.
56. Sisson, Si B. and 'G* V. Lee, Incineration Safely Disposes of
Chemical Cleaning Solvents, presented at the American Power
Conference, 1972.
57. Hittman Associates, Inc., Metal Cleaning Wastes File - A
Collection of letters and phone contacts .concerning Metal
Cleaning Wastes, Their Cleanup and Disposal, Hittman
Associates, Inc. 1976-1977.
58. Dow Industrial Service, ACR Process for Effective Chemical
Cleaning...Incineration for Safe Effective Waste Disposal,
Form No, 174-418-76, Dow Chemical, Midland, Michigan, 1976.
59. Engle, J. P. and J. T. Dillman, Chemical Cleaning of New
Power Boilers, Power Engineering, 1967.
60. Haller, W. A., Ash Basin Equivalency Demonstration Duke
Power Company, presented to the 39th Annual Meeting of the
American Power Conference, Chicago, Illinois, April 19,
1977. ' . •: " " "
61. Chas. T. Main, Inc., Design Report Was1;ewater Treatment
Facilities, New England Power Service.Company, Chas. T.
Main, Inc., Boston, MA, 1975. "I,..% ""/.>
62. Dascher, R.E., San Juan Station Water - Management Program
presented at the 39th Annual Meeting of .the American Power
Conference, Chicago, Illinois, April 19,,.1§77.
63. Kaercher, G. C. and R. M. Rosain, The Design-of Wastewater
Treatment Facilities for the Detroit Edison Company,
Presented to the 39th Annual Meeting of"the" American Power
Conference, Chicago, Illinois, April 19,""1977.
!•= •*••> »„,««*•'
64. Martin, L. D. and W. P. Banks, Electrochemical Investigation
of Passivating Systems, presented at the 35th Annual Meeting
International Water Conference, Pittsburgy PA, October 30 -
November 1, 1974. -'*"," ,2, «J:
.;. w 4, " •-.
65. Peltier, R. V. and J. E. Brennan, Design and Implementation
of the San Diego Gas & Electric Company, jjlastewater Treatment
System, presented at the 39th Annual Meeting of the American
Power Conference, Chicago, Illinois, April 19, 1977.
66. Kuppusamy, N., Copper removal from Power .Plant Boiler Clean-
ing Waste, Induudstrial Waste, 23(2), 43r-i5, March 1977.
67. Feigenbaum, H. M., Removing Heavy Metals in Textile Waste,
485
-------
Industrial Wastes, 11:(11) pp. 32-34, 1977.
68. "Steam: Its Generation and Use," 39th Edition, Babcock &
Wilcox Company, New York, NY, 1978.
69. Strumm, W. and J. J. Morgan, Aquatic Chemistry, Wiley-
Interscience, John Wiley & Sons, Inc., New York, NY, 1970.
SECTION IX •
1. "Development Document for Effluent Limitations Guidelines
and New Source Performance Standards for the Steam Electric
Power Generating Point Source Category," U.S. Environmental
Protection Agency, EPA-440l/l-74-029~a, October 1974.
486
-------
SECTION XII
GLOSSARY
. t.
This section is an alphabetical listing of technical terms (with
definitions) used in this document which may not be familiar to the
reader. •
Absolute Pressure
The total force per unit area measured above absolute vacuum as a
reference. Standard atmospheric pressure,is 101,326 N/m2 (14.696 psi)
above absolute vacuum (zero pressure absolute}.;?
Absolute Temperature
The temperature measured from a zero at which all molecular activity
ceases. The volume of an ideal gas is directly proportional to its
absolute temperature. It is measured in +K (+R) corresponding to +C +
273 (+F + 459). :
Acid
A substance which dissolves in water with the formation of hydrogen
ion. A substance containing hydrogen which may be displaced by metals
to form salts.
Acid-Washed Activated Carbon
Carbon which has been contacted with an acid solution with the purpose
of dissolving ash in the activated carbon.
Acidity
The quantitative capacity of aqueous solutions to react with hydroxyl
ions (OH-). The condition of a water solution having a pH of less
than 7.
Acre-Foot
(1) A term used in measuring the volume of water that is equal to the
quantity of water required to cover 1 acre 1 foot deep, or 43,560 ft3.
C2) A term used in sewage treatment in measuring the volume of
material in a trickling filter. One acre-foot contains 43,560 ft3 of
water.
Activated Carbon
Carbon which is treated by high-temperature heating with steam or
carbon dioxide producing an internal porous particle structure.
Absorption
487
-------
The adhesion of an extremely thin layer of molecules (of gas, liquid)
to the surfaces of solids (granular activated carbons for instance) or
liquids with which they are in contact.
Adsorption Isotherms (Activated Carbon)
A measurement of adsorption determined at a constant temperature by
varying the amount of carbon used or the concentration impurity in
contact with the carbon.' "
Advanced Waste Treatment
Any treatment method or process employed following biological
treatment (1) to increase the removal of pollution load, (2) to remove
substances which may be deleterious to receiving waters or the
environment, (3) to produce a high-quality effluent suitable for reuse
in any specific manner or for discharge under critical conditions.
The term tertiary treatment is commonly used to denote advanced waste
treatment methods.
Aerated Pond ,..,_,,,,
_• "I.:... -1. _l....—m-i«iumninoBmi.u.i_L._iLi-jij__j _
-------
lunlon
The charged particle in a solution of an electrolyte which carries a
negative charge. .•'.••>
An ion Ex change Process ' •' -
The reversible exchange of negative ions between functional groups of
the ion exchange medium and the solution in which the solid is
immersed. Used as a wastewater treatment process for removal of
anions, e.g., carbonate.
An ionic Surfactant - '•• . .
An ionic type of surface-active substance that has been widely used in
cleaning products. The hydrophilic group of these surfactants carries
a negative charge in washing solution.
Anthracite
A hard natural coal of high luster which contains little volatile
matter.
Apparent Density (Activated Carbon)
The weight per unit volume of activated carbon.
Approach Temperature ' • "•"'...-.
The difference between the exit temperature of water from a cooling
tower and the wet bulb"temperature of the air,
Aquifer
A subsurface geological structure that contains water.
Ash
The solid residue following combustion as a fuel.
Ash Sluice
The transport of solid residue ash by water flow in a conduit.
Backwashing .
The process of cleaning a rapid sand or mechanical filter by reversing
the flow of water.
Baffles ' ":' . .. ,.
Deflector vanes, guides, grids, gratings, or similar devices
constructed or placed in flowing water or sewage to (1) check or
489
-------
effect a more uniform distribution of velocities; (2). absorb energy?
(3) divert, guide, or agitate the liquids, and <4) check eddy
currents? •** ' •-
Bag Filter , ' • •
A fabric type filter in which dust laden gas is made to pass through
woven fabric to remove the particulate matter.
Banks, Sludge
Accumulations on the bed of a waterway of deposits of solids of sewage
or industrial waste origin.
Base
A compound which dissolves in water to yield hydorxyl ions COH-).
Base-Load Unit
MMMMMMmMMMMBMPMMMMM*MHMMPMMMI^MM> f «4 ^ ,,
An electric generating facility operating continuously at a constant
output with little hourly or daily fluctuation.
Bed Degsth (Activated Carbon)
The amount of carbon expressed in length units which is parallel to
the flow of the stream and through which the stream must pass.
Bioassav
,£ ^ • ""• >|t • . '
An assay method using a change in biological activity as a qualitative
or quantitative means of analyzing a meateerial response to industrial
wastes and other wastewaters by using viable organisms or live fish as
test organisms.
BiochemicalOxygen Demand(BOD)
(1) The quantity of oxygen used in the biochemicaoxidation of organic
matter in a specified time, at a specified temperature, and under
specified conditions.- "" ."'
(2) Standard test used in accessing wastewater strength.
Biocides
'ۥ 7 v *
Chemical agents with the capacity to kill biological life forms,
Bactericides, insecticides, pesticides, etc., are examples.
Bioctegradablg
The part of organic matter which can be oxidized by bioprocesses,
biodegradable detergents, food wastes, animal manure.
490
-------
Biological Wastewater Treatment
Forms of wastewater treatment in which bacterial or biochemical action
is intensified to stabilize, oxidize, and nitrify the unstable organic
matter present. Intermittent sand filters, contact beds, trickling
filters, and activated sludge process are examples.
Bituminous
A coal of intermediate hardness containing between 50 and 92 percent
carbon.
Slowdown
A portion of water in a closed system which is removed or discharged
in order to prevent a buildup of dissolved solids.
Boiler .
A device in which a liquid is converted into its vapor state by the
action of heat. In the steam electric generating industry, the
equipment which converts water into steam.
Boil.er Feedwater ' .. ...
The water supplied to a boiler to be converte*! into steam,
Boiler Fireside
The surface at which thfe boiler heat exchange elements are exposed to
the hot combustion products. - .
Boiler Scale . ."-". f .
A deposit of salts on the waterside of a boiler as a result of the
evaporation of water. , ._.;-\%^;.
Boiler Tubes ' ' ;; -•;•.-:.-;!
•.,•>'*£* i •
Tubes contained in a boiler through which water passes during its
conversion into steam*
•;< 6,1 - •
Bottom Ash
The solid residue left from the combustion of a fuel which falls to
the bottom of the combustion chamber. .,? ^
Brackish Water ' "' * -
Water having a dissolved solids content between that of fresh water
and that of sea water, generally from 1,000 to 10,000 mg per liter.
Brine
491
-------
Water saturated with a salt.
Buffer
Any of certain combinations of chemicals used to stabilize the pH
values or alkalinities of solutions.
Cake, Sludge
The material resulting from air drying or dewatering sludge (usually
forkable or spadable),
Calibration -
The determination, checking or rectifying of the graduation of any
instrument given quantitative measurements.
Capacity Factor
The ratio of energy actually produced to that which would have been
produced in the same period had the unit been operated continuously at
rated capacity.
Carbonate Hardness
Hardness of water caused by the presence of carbonates and
bicarbonates of calcium and magnesium.
Carbon Column A
A column filled with granular activated carbon whose primary function
is the preferential adsorption of a particular type or types of
molecules.
Catalyst
A substance which accelerates or retards a chemical reaction without
undergoing any permanent changes.
Cation
The charged particles in solution of an electrolyte which are
positively charged.
CationExchange Process
The reversible exchange of positive ions between functional groups of
the ion exchange medium and the solution in which the solid is
immersed. Used as a wastewater treatment process for removal of
cations, e.g., calcium.
Cationic Surfactant
492
-------
A surfactant in which the hydrophi1ic groups are positively charged;
usually a quaternary ammonium salt such as cetyl trimethyl ammqnium
bromide (CeTAB), C16H33N > (CH3)3 Br. Cationic surfactants, as a
class, are poor cleaners but exhibit remarkable disinfectant
properties.
Chelatinq Agents
A chelating agent can attache itself to central metallic atom so as to
form a heterocyclic ring. Used to make ion exchange more selective
for specific metal ions such as nickel, copper, and cobalt.
Chemical Analysis
The use of a standard chemical analytical procedure to determine the
concentration of a specific pollutant in a wastewater sample.
Chemical Coagulation
The destabilization and initial aggregation of colloidal and finely
divided suspended matter by the addition of a floe-forming chemical.
Chemical Oxygen Demand (COD)
A specific test to measure ; the amount of oxygen required for the
complete oxidation of all organic and inorganic matter in a water
sample which is susceptible to oxidation by a strong chemical oxidant.
Chemical Precipitation
(1) Precipitation induced by addition of chemicals.
(2) The process of softening water by the addition of lime and soda
ash as the precipitants.
Chemisorptlon
Adsorption where the forces holding the adsorbate to the adsorbent are
chemical (valance) instead of physical (van der Waals).
Chlorination
The application of chlorine to water or wastewater, generally for the
purpose of disinfection but frequently for accomplishing other
biological or chemical results.
Chlorination Break Point
The application of chlorine to water, sewage, or industrial waste
containing free ammonia to the point where free residual chlorine is
available.
Chlorination, Free Residual
493
-------
The application of chlorine to water, sewage, or industrial wastes to
produce directly or through the destruction of ammonia, or of certain
organic nitrogenous compounds, a free available chlorine residual.
Chlorine, Available
A term used in rating chlorinated lime and hypochlorites as to their
total oxidizing power. Also, a term formerly applied to residual
chlorine; now obsolete.
Chlorine, Combined Available Residual
That portion of the total residual chlorine remaining in water,
sewage, or industrial wastes at the end of specified contact period
which will react chemically and biologically as chloramines or organic
chloramines.
Chlorine Demand
The quantity of chlorine absorbed by wastewater (or water) in a given
length of time.
Chlorine, Total Residual
Free residual plus combined residual.
Clorite, High-Test Hypor-- T
A combination of lime and chlorine consisting largely of calcium
hypochloride.
Chlorite, Sodium Hypo •''•••'
A water solution of sodium hydroxide and chlorine in which sodium
hypochlorite is the essential ingredient.
Circulating Water Pumps
Pumps which deliver cooling water to the condensers of a powerplant.
Circulating Water System
A system whi'ch conveys cooling water from its source to the main
condensers and then to the point of discharge. Synonymous with
cooling water system.
Clarification
A process for the removal of suspended matter from a water solution.
Clarifier
494
-------
A basin in which water flows at a low velocity to allow settling of
suspended matter.
Colloids . •
A finely divided dispersion of one material called the "dispersed
phase" (solid); in another material which is called the "dispersion
medium" (liquid). Normally negatively charged.
Closed Circulating Water System
A system which passes water through the condensers then through an
artificial cooling device and keeps recycling it.
Coal Pile Drainage
Runoff from the coal pile as a result of rainfall.
Condensate Polisher
• • f^-. - '•• • ' •
An ion exchanger used to adsorb minute quantities of cations and
anions present in condensate as a result of corrosion and erosion of
metallic surfaces. ; iS , . ,
Condenser s^ -:• •;
A device for converting a vapor into its liquid-phase.
Construction -^ 0rSj .,-•-•..'
Any placement, assembly, or installation of facilities or equipment
(including contractual obligations to purchase such facilities .or
equipment) at the premises where the equipment will be used, including
preparation work at the premises. /; -;,;/;. >-A , ,
Convection The heat transfer mechanism arising from the motion of a
fluid.
-S-i' "
Composite Wastewater Sample -•-.-. ; r«..-,-
••^•^••••••••••(•^(•••••^•••••^••••••^•VMKMMMMBMIMMnMBBaMMWWMMMMIHMIB _ .'. ,± '-v?^-,-
A combination of individual samples of water or^wastewater taken at
selected intervals, generally hourly for soTSt specified period, to
minimize the effect of the variability of^-t-he individual samle.
Individual samples may have equal yplum§-.- or may be roughly
proportioned to the flow at time of sampling.
Concentrat ion, Hydrogen Ion
The weight of hydrogen ions in grams per Iiterfi9| solution. Commonly
expressed as the pH value that represents ' the logarithms of the
reciprocoal of the hydrogen ion concentration.
Cooling Canal
495
-------
A canal in which warm water enters at one end, is cooled by contact
with air, and is discharged at the other end.
Cooling Tower
A configured heat exchange device which transfers rejected heat from
circulating water to the atmosphere.
Cooling Tower Basin
A basin located at the bottom of a cooling tower for collecting the
falling water.
Cooling Water System
See Circulating Water System.
Corrosion Inhibitor
A chemical agent which slows down or prohibits a corrosion reaction.
Counterflow
A process in which two mediae flow through a system in .opposite
directions. •
Critical Point
The temperature and pressure conditions at which the saturated liquid
and saturated vapor states of a fluid are identical. For water-steam,
these conditions are 3208.2 psia and 705.47 +F.
Cycling Plant
A generating facility which operates between peak load and base load
conditions.
Cyclone Furnace
A water-cooled horizontal cylinder in which fuel is fired, heat is
released at extremely high rates, and combustion is completed. The
hot gases are then ejected into the main furnace. The fuel and
combustion air enter tangentially imparting a whirling motion to the
burning fuel, hence the name Cyclone Furance. Molten slag forms on
the cylinder walls and flows off for removal.
Data
Records of observations and measurements of physical facts,
occurrences, and conditions reduced to written, graphical, or tabular
form.
Data Correlation
496
-------
The process of the conversion of reduced data into a functional
relationship and the development of the significance of both the data
and the relationship for the purpose of process evaluation.
Data Reduction
The process for the conversion of raw field data into a systematic
flow which assists in recognizing errors, omissions, and the overall
data quality.
Data Si qn i f i cance . - -;''':' -
The result of the statistical analysis of a data group or bank wherein
the value or significance of the data receives a thorough appraisal.
Beaeratlon : - :
A process by which dissolved air and oxygen are stripped from water
either by physical or chemical methods.
Deaerator
A device for the removal of oxygen, carbon dioxide, and other gases
from water. ov;-
Dech1orination Process
A process by which excess chlorine is removed...from water to a desired
level, e.g., 0,1 mg/1 maximum limit. Usua~jKS^^accomplished by passage
through carbon beds or. by aeration at a suffkb^B pH.
<«* s- W W *•*- A. .
Degasif1cation
The removal of a gas from a liquid.
Deionizer ' - -
A process for treating water by removal of cations and anions.
Demineralizer V'"?,(1S">C*;
See Deionizer.
Demister • ' : *d*n »».-.
; . . :-;'*oli b,. .
A device for trapping liquid entrainment from gas or vapor streams.
Detention Time , ,
"'"• ' "" . S f? C' ,i 3 K* •
The time allowed for solids to coffec€"r in a settling tank.
Theoretically, detention time is equal to the volume of the tank
divided by the flow rate. The actual detention time is determined by
the purpose of the tank. Also, the design resident time in a tank or
497
-------
reaction vessel which allows a chemical reaction to go to completion,
such as the reduction of chromium +6 or the destruction of cyanide.
Dewater
To remove a portion of the" water from a sludge or a slurry.
Dew Point . ' •
The temperature of a gas-vapor mixture at which the vapor condenses
when it is cooled at constant humidity.
Diatomaceous Earth
A filter medium used for filtration of effluents from secondary and
tertiary treatments, particularly when a very high grade of water for
reuse in certain industrial purposes is.required. Also used as an
adsorbent for oils and oily: emulsions in some wastewater treatment
designs.
Diesel
An internal combustion engine in which the temperature at the end of
the compression is such that combustion is initiated without external
ignition.
Discharge ?;V- j?ru • : .
To release or vent. vc yll.»,, . •
'•RSiq 3- ' . •.'.'•'.'
Discharge Pipe
A section of pipe or conduit from the condenser discharge to the point
of discharge into receiving^waters or cooling device.
>C-5."^» ., ... . .
Dissolved Solids r.isogfiu ,„ / . ...''.
Theoretically, the anhydrous residues of the dissolved constituents in
water. Actually, the term is defined by the method used in
determination. In water and wastewater treatment, the Standard
Methods tests are used. ,?""">•
Diurnal Flow Curve
A curve which depicts M'tovrsdistribution over the 24-hour day.
Drift
Entrained water carried from a cooling device by the exhaust air,
Dry Bottom Furnace
498
-------
Refers to a furnace in which the ash leaves the boiler bottom as a
solid (as opposed to a molten slag).
Dry Tower
A cooling tower in which the fluid to be cooled flows within a closed
system which transfers heat to the environment using finned or
extented surfaces.
Dry Well
A dry compartment of a pump structure at or below pumping level where
pumps are located.
Economizer
A heat exchanger which uses the heat of combustion gases to raise the
boiler feedwater temperature before the feedwater enters the boiler,
Economizer Ash
Carryover ash from the boiler which due to its size and weight,
-settles in a hopper below the economizer.
Effluent
(1) A liquid, which flows out of a containing space.
(2) Sewage, water or other liquid, partially or, as the case may be,
flowing out of a reservoir basin, treatment plant, or part thereof.
Electrostatic Precipitator
A device for removing particles from a stream ; of gas based on the
principle that these particles carry electrostatic charges and can
therefore be attracted to an electrode by imposing a potential across
the stream of gas.
Evaporat ion " .»;
The process by which a liquid becomes a vapor. ..-.
Evaporator
A device which converts a liquid into a vapor>?ob~y the addition of heat.
Feedwater Heater
Heat exchangers in which boiler feedwater. bis preheated by steam
extracted from the turbine.
499
-------
Filter Bed
A device for removing suspended solids from water, consisting of
granular material placed in a layer(s) and capable of being cleaned
hydraulically by reversing the direction of the flow.
Filter, High-Rate
A trickling filter operated at a high average daily dosing rate. All
between 10 and 30 mgd/acre, sometimes including recirculation of
effluent.
Filter, Intermittent
A natural or artificial bed of sand or other fine-grained material to
the surface of which sewage is intermittently added in flooding doses
and through which it passes, opportunity being given for filtration
and the maintenance of aerobic conditions.
Filter, Low-Rate
A trickling filter designed to receive a small load of BOD per unit
volume of filtering material and to have a low dosage rate per unit of
surface area (usually 1 to 4 mgd/acre). Also called standard rate
filter.
Filter, Rapid Sand ; ;
-s •>• -^'r- •
A filter for the purification of water where water which has been
previously treated, usually by coagulation and sedimentation, is
passed downward through a filtering medium consisting of a layer of
sand or prepared anthracite coal or other suitable material, usually
from 24 to 30 inches,, thick and resting on a supporting bed of gravel
or a porous median such as carborundum. The filtrate is removed by an
underdrain system. The filter is cleaned periodically by reversing
the flow of the water upward through the filtering medium; sometimes
supplemented by mechanical or air agitation during backwashing to
remove mud and other impurities that are lodged in the sand.
Filter, Vacuum ' ', ~
A filter consisting of a cylindrical drum mounted on a horizontal
axis, covered with a filter cloth revolving with a partial submergence
in liquid. A vacuum is maintained under the cloth for the larger part
of a revolution to extract^ moisture and the cake is scraped off
continuously.
Filtration
The process of passrhg a liquid through a filtering medium for the
removal of suspended or colloidal matter.
Fireside Cleaning
500
-------
Cleaning Of the OUtSide surface of boiler tubes and combustion chamber
refractories to remove deposits formed during the combustions.
Floe
A very fine, fluffy mass formed by the aggregation of
particles.
Flocculator
fine suspended
An apparatus designed for the formation of floe in water or sewage.
Flocculation
In water and wastewater treatment, the agglomeration of colloidal and
finely divided suspended matter after coagulation by gently stirring
by either mechanical or hydraulic means. In biological wastewater
treatment where coagulation is not used, agglomeration may be
accomplished biologically.
Flow Rate ,,.. , we,P-,
Usually expressed as liters/minute (gallons/minute) or liters/day
(million gallons/day). Design flow rate is that used to size the
wastewater treatment process. Peak flow rate is 1.5 to 2.5 times
design and relates to the hydraulic flow limit and is specified for
each plant. Flow rates can be mixed as batch and continuous where
these two treatment modes are used on the same;,plant.
Flow-Nozzle Meter
L Ft 'J
• ::, •' p --, e - .
A water meter of the differential medium type" in which the flow
through the primary element or nozzle produces'a .pressure difference
or differential head, which the secondary element, or float tube then
uses as an indication of the rate of flow. ,, ,.7* --,-
Flue Gas
The gaseous products resulting from the combustion process after
passage through the boiler.
~ '*.o
Fly Ash ,-jIi:
A portion of the noncombustible residue from a7«i|iel which is carried
out of the boiler by the flue gas.
Fossil Fuel
A natural solid, liquid, or gaseous fuel such as coal, petroleum, or
natural gas. r,;'lll-
Frequency Distribution
501
-------
An arrangement or distribution of quantities pertaining to a single
element in order of their magnitude.
Gauging Station
A location on a stream or conduit where measurements of discharge are
customarily made. The location includes a stretch of channel through
which the flow is uniform and a control downstream from this stretch.
The station usually, has a recording or other gauge for measuring the
elevation of the water surface in the channel or conduit.
Grab Sample
A Single sample of wastewater taken at neither a set time nor flow.
Generation
The conversion of chemical or mechanical energy into electrical
energy.
Hardness
A characteristic of water, imparted by salts of calcium, magnesium,
and iron, such as bicarbonates, carbonates, sulfates, chlorides, and
nitrates, that causes curdling of soap, deposition of scale in
boilers, damage in * some industrial process, and sometimes
objectionable taste. It may be determined by a standard laboratory
procedure or computed from the amounts of calcium and magnesium as
well as iron, aluminum, manganese, barium, strontium, and zinc, and is
expressed as equivalent calcium carbonate.
Heat of AbsorPti on
The heat given off when molecules are adsorbed.
High Rate
The fuel heat input (in Joules or Btu's) required to generate a kWh.
Heating Value
The heat available from the combustion of a given quantity of fuel as
determined by a standard calorimetric process.
Humidity
Pounds of water vapor carried by 1 pound of dry air.
Ion
A charged atom, molecule or radical, the migration of which affects
the transport of electricity through an electrolyte.
502
-------
Ion Exchange
A chemical process involving reversible interchange of ions between a
liquid and solid but no radical change in the structure of the solid.
Incineration . ,--.-.•..
The combustion (by burning) of organic matter in wastewater sludge
solids after water evaporation from the solids.
Lagoon • •• ..,-... .........
(1) A shallow body of water as a pond or lake which usually has a
shallow, restricted inlet from the,sea.
(2) A pond containing raw or partially treated wastewater in which
aerobic.or anerobic stabilization occurs.
Lignite
A carbonaceous fuel ranked between peat and coal.
Lime
Any of a family of chemicals consisting, essentially of calcium
hydroxide made from limestone (calcite) which is composed almost
wholly of calcium carbonate or a mixture of calcium and magnesium
carbonates. . . •;• : • '-•-
Makeup Water Pumps ' "'••-.. :.'<:.
Pumps which provide water to replace that lost by evaporation,
seepage, and blowdown.
Manometer
An instrument for measuring pressure. It usually consists of a U--
shaped tube containing a liquid, the surface of which moves
proportionally with changes in pressure on the liquid in the other
end. Also, a tube type of differential pressure gauge.
Mean Velocity : ' •,;
The average velocity of a stream flowing in a channel or conduit at a
given cross section or in a given reach. It is equal to the discharge
divided by the cross sectional area of the reach. Also called average
velocity. :
Mechanical Draft Tower . . -
A cooling, tower in which the air flow through the tower is maintained
by fans. In forced draft towers, the air is forced through the tower
503
-------
by fans located at its base; whereas in induced draft towers, the air
is pulled through the tower by fans mounted on top of the tower.
Mesh Size (Activated Carbon)
The particle size of granular activated carbon as determined by the
U.S. Sieve series. Particle size distribution within a mesh series is
given in the specification of the particular carbon.
Milligrams Per Liter (mg/1)
This is a weight per volume designation used in water and wastewater
analysis.
Mine-Mouth Plant
A steam electric powerplant located within a short distance of a coal
mine and to which the coal is transported from the mine by a conveyor
system, slurry pipeline, or truck.
Mixed-Media Filtration *
A filter which uses two or more filter materials- of differing specific
gravities selected so -as to produce a filter uniformly graded from
coarse to fine.
Mole
The molecular weight of a substance expressed in grams (or pounds).
Monitoring
(1) The procedure or operation of locating and measuring radioactive
contamination by means of survey instruments that can detect and
measure, as dose rate, ionizing radiations.
(2) The measurements, sometimes continuous, of water quality.
Name Plate
Name plate—design rating of a plant or specific piece of equipment.
Natural Draft Cool ing Tower
A cooling tower through which air is circulated by a natural or
Chimney effect. A hyperbolic tower is a natural draft tower that is
hyperbolic in shape.
Neutralization
Reaction of acid or alkaline solutions with the opposite reagent until ;
the concentrations of hydrogen and hydorxyl ions are about equal. !
504
-------
New Source
Any source, the construction of which is begun after the publication
of proposed Section 306 regulations, (March 4, 1974 for the Steam
Electric Power Generating Point Source Category).
Nominal Capacity
See Name Plate.
Nuclear Energy
The energy derived from the fission of nuclei of heavy elements such
as uranium or thorium or from the fusion of the nuclei of light
elements such as deuterium or tritium.
Once-Through Circulating Water System
A circulating water system which draws water from a natural source,
passes it through the main condensers, and returns it to a natural
body of water.
Osmosis
The process of diffusion of a solvent through a semipermeable membrane
from a solution of lower to one of higher concentration.
Osmotic Pressure
The equilibrium pressure differential across a semipermeable membrane
which separates a solution of lower from one of higher concentration.
Overflow
(1) Excess water over the normal operating limits disposed of by
letting it flow out through a device provided for that purpose. (2)
The device itself that allows excess water to flow out.
Outfall
The point or location where sewage or drainage discharges from a
sewer, drain, or conduit.
Oxidation • ;
The addition of oxygen to a chemical compound, generally any reaction
which involves the loss of electrons from an atom.
Package Sewage Treatment Plant
A sewage treatment facility contained in a small area and generally
prefabricated in a complete- package.
505
-------
Packing (Cooling Towers)
A media providing large surface area for the purpose of enhancing mass
and heat transfer, usually between a gas vapor and a liquid.
Peak-Load Plant
A generating facility operated only during periods at maximum demand.
pH Value
A scale for expressing the acidity or alkalinity of a solution.
Mathematically, it is the logarithm of the reciprocal of the gram
ionic hydrogen equivalents per liter. Neutral water has a pH of 7.0
and hydrogen ion concentration of 107 moles per liter.
PIaced in Servl.ce
Refers to the data when a generating unit initially generated
electrical power to service customers.
P1ant Code Number
A four-digit number assigned to all powerplants in the industry
inventory for the purpose of this study.
Plume (Gas)
A conspicuous trail of gas or vapor emitted from a cooling tower or
chimney.
Pond, Sewage Oxidation.
A pond, either natural or artificial, into which partly treated sewage
is discharged and in which natural purification processes take place
under the influence of sunlight and air.
Powerpiant
Equipment that produces electrical energy generally by conversion from
heat energy produced by chemical or nuclear reaction.
Precipitation
A phenomenon that occurs when a substance held in solution in a liquid
phase passes out of solution into a solid phase.
Preheater (Air)
A unit used to heat the air needed for combustion of absorbing heat
from the products of combustion.
Psychrometr i c
506-
-------
Refers to air-water vapor mixtures and their properties. A
psychrometric chart graphically displays the relationship between
these properties.
Pulverized Coal . " . . • . '
Coal that has been ground to a powder, usually of a size where 80
percent passes through a 1200 U.S.S. sieve.
Pyrites ' - •- . ' - . -
Combinations of iron and sulfur found in coal as FeS2.
Radwaste
Radioactive waste streams from nuclear powerplants.
Range
Difference between entrance and exit temperature of water in a cooling
tower,
Rank of Coal
A classification of coal based upon the fixed carbon as a dry weight
basis and the heat value.
RankineCycle
The thermodynamic cycle which is the basis of the steam electric
generating process,
Recirculation System
Facilities which are specifically designed to divert the major portion
of the cooling water discharge back for reuse.
Reduction ' . . . .
A chemical reaction which involves the addition of electrons to an ion
to decrease its positive valence.
Regeneration
Displacement from ion exchange resins of the ions removed from the
process solution.
Reheater
A heat exchange device for adding superheat to steam which has been
partially expanded in the turbine.
Reinlection
507
-------
To return a flow, or portion of flow, into i process.
Re1atiye Humid i tv
Ratio of the partial pressure of the water vapor to the vapor pressure
of water at air temperature.
ResidualChlorine
Chlorine remaining in water or wastewater at the end of specified
contact period as combined or free chlorine.
ReverseOsmosis
The process of diffusion of a solute through a semipermeable membrane
from a solution of lower to one of higher concentration, affected by
raising the pressure of the less concentrated solution to above the
osmotic pressure.
Salinity
(I) The relative concentration of salts, usually sodium chloride, in
a given water. It is usually expressed in terms of the number of
parts per million of chloride (CD.
(2) A measure of the concentration of dissolved mineral substances in
water.
Sampler
A device used with or without flow measurement to obtain any adequate
portion of water or waste for analytical purposes. May be designed
for taking a single sample (grab), composite sample, continuous
sample, or periodic sample,
Sampli ng Stations
Locations where several flow samples are tapped for analysis,
San i tary Wastewater
Wastewater discharged from sanitary conveniences of dwellings and
industrial facilities.
Saturated A i r
Air in which water vapor is in equilibrium with liquid water at air
temperature.
Saturated Steam
Steam at the temperature and pressure at which the liquid and vapor
phase can exist in equilibrium.
508
-------
Scale
Generally insoluble deposits on equipment and heat transfer surfaces
which are created when the solubility of a salt is exceeded. Common
scaling agents are calcium carbonate and calcium sulfate.
Scrubber
A device for removing particles or objectionable gases from a stream
of gas.
Secondary Treatment
The treatment of sanitary wastewater by biological means after primary
treatment by sedimentation. .
Sedimentation
The process of subsidence and deposition of suspended matter carried
by a liquid.
Sequestering Agents
Chemical compounds which are added to water systems to prevent the
formation of scale by holding the insoluble compounds in suspension.
Service Water Pumps
Pumps providing water for auxiliary plant heat exchangers and other
uses.
Settleable Solids ,
(1) That matter in wastewater which will not stay in suspension
during a preselected settling period, such as 1 hour but either
settles to the bottom or floats to the top.
(2) In the Imhoff cone test, the volume of matter that settles to the
bottom of the cone in 1 hour.
Slag Tap Furnace
Furnace in which the temperature is high enough to maintain ash (slag)
in a molten state until it leaves the furnace through a tap at the
bottom. The slag falls into the sluicing water where it cools,
disintegrates, and is carried away.
Slimicide
An agent used to destroy or control slimes.
Sludge
509
-------
Accumulated solids separated from a liquid during processing.
Softener
Any device used to remove hardness from water. Hardness in water is
due mainly to calcium and magnesium salts. Natural zeolites, ion
exchange resins, and precipitation processes are used to remove the
calcium and magnesium.
Spinning Reserve
The power generating reserve connected to the bus bar and ready to
take load. Normally consists of units operating at less than full
load. Gas turbines, even though not running, are considered spinning
reserve due to their quick startup time.
Spray Module (Powered Spray Module)
A water cooling device consisting of a pump and spray nozzle or
nozzles mounted on floats and moored in the body of water to be
cooled. Heat is transferred principally by evaporation from the water
drops as they fall through the air.
Stabilization Lagoon
A shallow pond for storage of wastewater before discharge. Such
lagoons may serve only to detain and equalize wastewater composition
before regul-ated discharge to a stream, but often they are used for
biological oxidation.
Stabilization Pond
A type of oxidation pond in which biological oxidation of organic
matter is affected by natural or artifically accelerated transfer of
oxygen to the water from air.
Steam Drum
Vessel in which the saturated steam is separated from the steam-water
mixture and into which the feedwater is introduced.
Supercritical
Refers to boilers designed to operate at or above the critical point
of water 22,100 kN/square meters and 374.0+C (3206.2 psia and
705.4+F).
Superheated Steam
Steam which has been heated to a temperature above that corresponding
to saturation at a specific pressure.
Suspended Solids
510
-------
(1) Solids which either float on the surface of or are in suspension
in water, wastewater, or other liquids, and which are largely
removable by laboratory filtering.
(2) The quantity of material removed from wastewater in a laboratory
test, as prescribed in "Standard Methods for the Examination of Water
and Wastewater" and referred to as nonfilterable residue.
Thermal Efficiency
The efficiency of the thermodynamic cycle in producing work from heat.
The ratio of usable energy to heat input expressed as a percent.
Thickening
Process of increasing the solids content of sludge.
Total Dynamic Head (TDH)
Total energy provided by a pump consisting of the difference in
elevation between the suction and discharge levels, plus losses'due to
unrecovered velocity heads and friction.
Total Solids
The total amount of solids in a wastewater in both solution and
suspension.
Turbine
A device used to convert the energy of steam or gas into rotational
mechanical energy and used as prime mover to drive electric
generators.
Treatment Efficiency
Usually refers to the percentage reduction of a specific or group of
pollutants by a specific wastewater treatment step or treatment plant.
Turbidmeter
An instrument for measurement of turbidity in which a standard
suspension usually is used for reference.
Turbidity
(1) A condition in water or wastewater caused by the presence of
suspended matter, resulting in the scattering and adsorption of light
rays.
(2) A measure of fine suspended matter in liquids.
511
-------
(3) An analytical quantity usually reported in arbitrary turbidity
units determined by measurements of light diffraction.
Turbulent Flow
(1) The flow of a liquid past an object such that the velocity at any
fixed point in the fluid varies irregularly.
{2) A type of liquid flow in which there is an unsteady motion of the
particles and the motion at a fixed point varies in no definite
manner. Sometimes called eddy flow, sinuous flow.
In steam electric generation, the basic sysem for power generation
consisting of a boiler and its associated turbine and generator with
the required auxiliary equipment.
Utility
(Public utility)—A company either investor-owned or publicly owned
which provides service to the public in general. The electric
utilities generate and distribute electric power.
Volatlle Combustion Matter
The relatively light components in a fuel which readily vaporize at a
relatively low temperature and which when combined or reacted with
oxygen, giving out light and heat.
Wet Bottom Furnace
See slag-tap furnace.
Wet Bulb Temperature
The steady-state, nonequilibrium temperature reached by a small mass
of water immersed under adiabatic conditions in a continuous stream of
air.
Wet^Scrubber
A device for the collection of particulate matter from a gas stream or
adsorption of certain gases from the stream.
512
-------
APPENDIX A
TVA RAW RIVER INTAKE AND
ASH POND DISCHARGE DATA
Quarterly Samples
1973-1976
513
-------
Table A-l
TVA PLANT A RIVER WATER INTAKE AND FLY ASH POND DISCHARGE DATA
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
ui Chromium, mg/1
tj Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, »g/l
Sulfate, mg/1
Zinc, mg/1
1/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
6.4
0.10
0.023
0.3
<0.01
0.037
170
6
0.049
750
0.36
<0.01
480
1.1
<0.010
13
0.50
0.0006
0.13
0.18
0.004
15
-------
Table A-l (Continued)
TVA PLANT A RIVER HATER INTAKE AND FLY ASH POND DISCHARGE DATA
(Quarterly Samples)
Ul
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1 •
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, aig/1
1/15/74
River
Intake
5.7
0.14
<0.005
0.1
<0.01
<0.001
24
4
0.021
140
0.19
-
69
5.4
0.02
4.1
0.17
<0.0002
<0.05
0.12
<0.002
5.2
<0.01
120
100
6
0,09
Pond
Discharge
13
« 1.4
0.005
0.2
<0.01
0.041
110
5
0.17
710
0.45
<0.01
340
6.6
0.20
17
0.63
<0.0002
0.10
0.02
0.002
11
<0.01
620
6
280
2.7
4/8/74
River
Intake
6.7
0.04
<0.005
0.4
<0.01
<0.001
27
4
0.024
210
0.14
-
91
6.7
<0.010
5.7
0.25
<0.0002
0.05
0.13
<0.002
6.9
<0.01
120
190
28
0.12
Pond
Discharge
6.6
1.0
<0.005
0.4
0.02
0.030
94
5
0.056
740
0.30
<0.01
320
1.0
0.021
20
0.59
<0.0002
0.08
0.02
<0.002
12
<0.01
560
5
430
1.1
7/15/74
River
Intake
1.0
0.04
<0.005
0.2
<0.01
<0.001
41
9
<0.005
320
0.08
-
140
1.3
0.026
8.0
o.io
<0.0002
<0.05
0.04
<0.002
1.7
<0.01
200
14
24
0.08
Pond
Discharge
3.6
0.26
0.005
0.3
<0.01
0.038
94
8
0.12
640
0.16
<0.01
280
0.33
<0.024
12
0.29
<0.0002
0.06
0.02
<0.002
—
0.01
470
2
240
1.3
10/8/74
River
Intake
1.1
0.02
<0.005
0.2
<0.01
<0.001
41
9
0.008
310
0.04
-
90
1.1
0.038
6.8
0.08
<0.0002
<0.05
0.03
<0.002
6.3
<0.01
170
45
15
0.06
Pond
Discharge
7.9
0.15
0.010
0.2
<0.01
0.037
110
6
0.082
680
0.30
_
310
0.60
0.064
9.4
0.31
<0.0002
0.11
0.02
<0.002
10
<0.01
500
6
380
1.4
-------
Table A-l (Continued)
TVA PLANT A RIVER WATER INTAKE AND FLY. ASH POND DISCHARGE DATA
(Quarterly Samples)
Ul
CTx
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, iag/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, nig/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
2/3/75
River
Intake
0.05
0.10
no sample
<0.1
<0.01
0.004
29
6
<0.005
240
0.05
<0.01
91
1.4
0.021
4.5
0.12
<0.0002
<0.05
<0.01
no sample
8.0
<0.01
140
57
30
0.14
Pond ,
Discharge
6.2
1.2
<0.005
<0.1
<0.01
0.025
88
5
0.052
590
0.24
<0.01
270
2.2
0.052
13
0.44
<0.0002
0.07
<0.01
<0.002
9.3
<0.01
470
4
290
0.82
4/7/75
River
Intake
*
0.02
<0.005
*
*
*
*
4
*
190
*
-
*
*
*
*
*
<0.0002
*
0.05
<0.002
5.6
*
150
21
28
*
Pond
Discharge
10
0.75
<0.005
-------
Table A-l (Continued)
TVA PLANT A RIVER WATER INTAKE AND FLY ASH POND DISCHARGE DATA
(Quarterly Samples)
Date
1/8/76
4/13/76
Ul
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25 °C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous , mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, »g/l
Solids, Suspended, mg/1
Sul fate, mg/1
Zinc, mg/1
River
Intake
1.2
0.07
<0.005
<0.1
<0.01
<0.001
42
5
XO.OQ5
240
0.02
-
130
1.2
<0.010
5.4
0.10
<0.0002
<0.05
0.04
<0.002
7.0
<0.01
150
31
16
0.02
Pond
Discharge
9.5
0.89
0.005
<0.1
<0.01
0.049
"92
6
0.080
660
0.32
_
280
5.6
0.050
13
0.46
<0.0002
0.05
0.06
-
14
<0.01
480
25
320
0.74
River
Intake
1.0
0.03
<0.005
<0.1
<0.01
<0.001
32
6
<0.005
220
0.03
-
100
1.3
<0.010
5.5
0.12
<0.0002
<0.05
0.04
<0.002
*
<0.01
130
36
16
0.06
Pond
Discharge
7.4
0.55
-------
Table A-2
TVA PLANT A RIVER WATER INTAKE AND BOTTOM ASH POND DISCHARGE DATA
(Quarterly Samples)
Ul
M
00
Date
Aluminum, rag/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, uohos/<
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, rag/1
Sulfate, »g/l
Zinc, mg/1
1/2/73
River
Intake
NA
NA
NA
NA
NA
NA
. NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.6
0.06
0.002
<0.1
<0.01
<0.001
33
6
<0.005
250
0.04
<0.01
110
3.8
<0.010
5.7
0.12
0.0008
<0.05
0.17
0.002
7.3
<0.01
170
27
41
0.08
ft/2/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
0.9
0.06
0.005
<0.1
<0.01
<0.001
33
8
<0.005
250
<0.01
<0.01
110
2.0
0.010
6.7
0.14
0.0004
<0.05
<0.03
<0.004
8.1
<0.01
180
13
45
0.03
7/2/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
MA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
8.0
0.06
0.015
0.1
<0.01
<0.001
44
8
<0.005
290
0.08
<0.01
140
7.5
<0.010
6.7
0.25
<0.0026
<0.05
0.36
<0.001
6.1
<0.01
180
74
50
0.07
10/1/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
0.7
0.22
<0.005
0.1
<0.01
<0.001
67
15
<0.005
400
0.03
<0.01
170
2.1
<0.010
0.3
0.15
<0.0002
0.12
0.09
<0.001
8.6
3<0.01
260
6
80
0.02
NA = Not Available
-------
Table A-2 (Continued)
TVA PLANT A RIVER WATER INTAKE AND BOTTOM ASH POND DISCHARGE DATA
(Quarterly Samples)
Ul
i_i
us
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1 :
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/15/74
River
Intake
5.7
0.14
<0.005
0.1
<0.01
<0.001
21
4
0.021
140
0.19
.-
69
5.4
0»02
4.1
0.17
<0.0002
<0,05
0.12
<0.002
5.2
<0.01
120
100
6
0.09
Pond
Discharge
6.0
0.05
0.005
0.1
<0.01
<0.001
23
5
0.023
180
0.12
<0.01
76
11
0.031
4.4
0.16
<0.0002
<0.05
0.14
0.004
6.3
<0.01
150
120
41
0.14
4/8/74
River
Intake
6.7
0.04
<0.005
0.4
<0.01
<0.001
27
4
0.024
210
0.14
_
91
6.7
<0.010
5.7
0.25
<0.0002
<0.05
0.13
<0.002
6.9
<0.01
120
190
28
0.12
Pond
Discharge
7.9
0.34
0.005
0.3
<0.01
<0.001
30
6
0.011
250
0.14
<0,01
100
10
0.019
6.0
0.26
0.0006
<0.05
0.23
<0.002
7.4
<0.01
170
200
48
0.16
7/15/74
River
Intake,
1.0
0.04
<0.005
0.2
<0.01
<0.001
41
9
<0.005
320
0.08
-
140
1*3
0.026
8.0
0.10
<0.0002
<0.05
0.04
<0.002
1.7
<0.01
200
14
24
0,08
Pond
Discharge
0.5
0.12
<0.005
0.2
<0.01
0.002
44
10
<0.005
360
0.01
<0.01
150
1.7
0.020
9.3
0.07
X0.0002
0.05
0.03
<0.002
- ' •
<0.01
240
5
42
0.07
10/8/14
River
Intake
1.1
0.02
<0.005
0.2
<0.01
<0.001
41
9
0.008
310
0.04
_
90
1.1
0.038
6.8
0.08
«0.0002
<0.05
0.03
<0.002
6.3
<0;01
170
45
15 '.
0.06
' fond
Discharge
1.3
0.04
<0.005
0.2
<0.01
<0.001
47
9
0.010
320
0.09
_
150
4.2
0.020
7.7
0.12
<0.0002
<0.05
0.03
<0.002
8. 0
<0.01
200
26
43
0.15
-------
Table A-2 (Continued)
TVA PLANT A RIVER HATER INTAKE AND BOTTOM ASH POND DISCHARGE DATA
(Quarterly Saaples)
m
to
o
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, tag/1
Barium, mg/1
Berylliun, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, uinhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, ng/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/14/75
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
4.9
0.06
<0.005
0.1
<0.01
<0.001
34
5
<0.005
260
0.02
<0.01
110
8.3
0.018
5.8
0.24
<0.0002
<0.05
0.08
<0.002
9.3
<0.01
170
110
29
0.06
4/7/75
River
Intake
*
0.02
<0.005
*
*
*
*
4
*
190
*
_
*
*
*
*
*
<0.0002
*
0.05
<0.002
5.6
*
150
21
28
*
Pond
Discharge
3.1
0.06
<0.005
<0.1
<0.01
0.002
23
4
0.005
200
0.09
-
76
5.6
0.028
4.6
0.13
<0.0002
<0.05
0.02
<0.002
6.0
<0.01
140
21
40
0.10
7/14/75
River
Intake
1.2
0.04
<0.1
<0.01
0.001
48
5
<0.005
280
0.04
-
150
1.4
<0.010
6.6
0.10
<0.0002
0.05
0.14
<0.002
6.0
<0.01
170
18
18
0.06
Pond
Discharge
0.7
0.09
<0.005
<0.1
<0.01
0.001
51
6
<0.005
320
0.11
-
160
2.3
<0.010
7.1
0.12
<0.0002
<0.05
0.02
<0.002
7.6
<0.01
200
6
63
0.09
10/14/75
River
Intake
2.1
0.14
0.005
<0.1
<0.01
<0.001
35
10
<0.005
260
0.09
-
120
1.9
0.022
7.1
0.12
<0.0002
<0.05
0.06
<0.001
5.4
<0.01
160
33
21
0.10
Pond
Discharge
2.1
0.14
0.015
<0.1
<0.01
0.002
26
7
<0.005
160
0.09
-
94
4.1
0.018
7.1
0.25
<0.0002
<0.05
0.05
<0.001
6.5
K0.01
160
14
23
0,02
NA = Not Available
*Bottle Broken
-------
Table A-2 (Continued)
TVA PLANT A RIVER WATER INTAKE AND BOTTOM ASH POND DISCHARGE DATA
(Quarterly Samples)
ui
Date
Aluminum, mg/1
Ammonia as N, mg/1.
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dis solved ,. mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/8/76
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
1A
NA
NA
NA
NA
NA
NA
Pond
Discharge
3.3
0.06
0.005
<0.1
<0.01
<0.001
43
6
0.008
280
0.08
-
130
4.7
<0.010
6.0
0.14
<0.0002
<0.05
0.07
<0.002
7.6
<0.01
190
42
45
0.12
4/13/76
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA ,
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.0
0.07
<0.005
<0.1
<0.01
<0.001
38
6
<0.005
260
0.09
—
120
4.4
<0.010
6.3
0.15
<0.0002
<0.05
0*06
<0.002
6.3
<0.01
160
33
41
0.09
NA » Not Available
*Bottle Empty
-------
Table A-3
TVA PLANT B RIVER WATER INTAKE AND FLY ASH POND DISCHARGE DATA
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
y, Chromium, mg/1
£» Conductivity, 25°C, umhos/em
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/21/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
MA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.8
0.11
0.065
0.1
<0.01
<0.001
250
7
0.036
mo
<0.01
<0.01
650
0.69
<0.010
6.8
0.04
0.0056
<0.05
0.55
0.064
8.0
<0.01
760
13
450
0.08
4/5/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
0.7
0.20
0.050
<0.1
<0.01
0.002
130
4
<0.005
580
0.02
<0.01
340
7.1
<0.010
4.4
0.63
0.0002
<0.05
0.24
0.007
22
<0.01
440
14
230
0.04
7/23/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
4.8
0.08
0.010
0.1
<0.01
<0.00i
430
6
0.011
2,200
0.02
<0.01
1,100
1.2
<0.010
0.2
0.04
0.0010
<0.05
0.03
0.030
3.7
<0.01
1,100
28
480
0,09
10/1/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.6
0.04
0.005
<0.1
<0.01
<0.001
33
8
<0.005
240
<0.01
<0.01
110
4.2
<0.010
5.9
0.12
<0.0002
<0.05
0.18
<0.001
6.0
_<0.01
Jfto
39
44
0.03
NA » Not Available
-------
table A-3 (Continued)
TVA PLANT B RIVER WATER INTAKE AND FLY ASH POND DISCHARGE DATA
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Sus pe nded, mg/1
Sulfate, mg/1
Zinc, mg/1
2/12/74
River
Intake
1.6
0.04
<0.005
<0. 1
<0.01
<0.001
19
4
<0.005
150
<0,01
-
67
0.9
0.010
4.7
0.06
<0.0002
<0.05
-
<0.001
7.2
<0.01
90
14
12
0.02
Pond
Discharge
0.8
0.09
0.010
<0.1
<0.01
<0.001
120
6
0.017
550
<0.01
<0.01
320
1.1
<0.010
4.4
0.05
<0.0002
0.08
0.10
0.004
7.8
<0.01
40
15
190
0.02
5/15/74
River
Intake
1.0
0.05
<0.005
<0.1
<0.01
<0.001
22
4
<0.005
150
0.04
- •
76
0.47
<0.010
5.0
0.04
0.0009
<0.05
0.03
<0.002
5.1
<0.01
90
4
11
<0.01
4/8/74
Pond
Discharge
1.8
<0.01
0.065
0.2
<0.01
<0.001
27
4
0.010
200
<0.05
<0.01
79
0.66
0.027
2.8
0.06
<0.0002
<0.005
0.13
0.007
3.8
<0.01
130
15
35
<0.01
8/13/74
River
Intake
0.6
0.06
<0.005
<0.1
<0.01
<0.001
22
6
<0.005
170
<0.01
-
77
0.44
<0.010
5.0
0.1
<0.0002
<0.05
0.04
<0.002
4.8
<0.01
100
7
14
0.01
7/16/74
Pond
Discharge
1.0
<0.01
0.055
<0.1
<0.01
0.002
50
6
<0.005
67
<0.01
<0.01
140
0.26
0.024
4.1
0.02
<0.0002
<0.05
0.10
<0.002
• _
<0.01
250
3
110
0.13
11/12/74
River
Intake
0.2
0.04
<0.005
<0.1
<0.01
0.002
19
7
<0.005
-
<0.01
-
69
0.36
<0.010
5.2
0.05
<0.0002
<0.05
0.02
<0.002
4.6
<0.01
-
-
14
<0.01
HO/30/74
Pond
Discharge
0.9
0.02
<0.005
0.1
<0.01
0.001
95
8
0.034
620
0.04
_
250
0.19
<0.010
2.3
0.05
<0.0002
<0.05
<0.01
<0.002
4.5
<0.01
460
2
230
0.06
-------
Table A-3 (Continued)
TVA PLANf B RIVER WATER INTAKE AND FLY ASH POND DISCHARGE DATA
(Quarterly Samples)
Date
Aluminum, »g/l
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, rag/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
2/4775
River
Intake
maj
0.08
<0.005
-
-
<0.001
17
6
<0.005
160
0.02
_. -'
- 57
0.32
-
3.6
0.06
<0.0002
-
0.02
<0.002
5.6
-
100
12
18
0.04
1/15/75-
Pond
Discharge
0.6
0.09
<0.005
0.2
<0.01
<0.001
110
7
<0.005
650
<0.01
<0.01
290
0.48
0.014
3.6
0.31
<0.0002
<0.05
0.01
<0.002
5.9
<0.01
440
6
160
0.04
5/19/T5
River
Intake
0.4
0.08
<0.005
<0.1
<0.01
0.003
20
4
<0.005
150
<0.01
-
67
0.68
<0.010
4.5
0.04
<0.0002
<0.05
0.02
<0.002
3.2
<0.01
90
8
9
<0.01
4/21/75
Pond
Discharge
1.3
0.11
0.005
<0.1
<0.01
<0.001
220
7
0.020
880
0.03
_
550
0.21
0.030
0.6
0.03
0.0004
0.06
<0.01
0.022
7.2
<0.01
520
6
300
0.02
8/5/75
River
Intake
0.5
0.05
<0.005
<0.1
<0.01
0.01
-
7
<0.005
-
0.02
_
0.38
<0.010
-
0.08
<0.0002
<0.05
0.02
<0.002
5.6
<0.05
90
9
10
0.02
4/14/75
Pond
Discharge
1.6
0.02
0.070
0.2
<0,01
0.001
190
6
0.006
790
0.08
480
0.27
<0.010
2.1
0.02
0.0120
<0.05
0.04
0.018
6.5
<0.01
600
10
17
0.06
11/4/75
River
Intake
0.7
0.04
0.005
<0.1
<0.01
0.002
16
7
<0.005
140
<0.01
56
0.37
<0.010
3.8
0.06
<0.0002
<0.05
0.01
<0.002
4.8
<0.01
95
5
10
<0.01
10/14/75
Pond
Discharge
1.5
0.06
0.008
<0.1
<0.01
<0.001
170
7
<0.005
730
0.10
450
0.14
<0.010
6.1
0.03
0.0002
<0.05
* 0.04
0.025
3.1
<0.01
600
2
320
0.03
-------
Table A-4
TVA PLANT B RIVER WATER INTAKE AND BOTTOM ASH POND DISCHARGE DATA
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
01 Chromium, mg/1
£J Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1 .
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/21/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
MA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.5
0.09
<0.005
<0.1
<0.01
<0.001
24
7
<0.005
210
<0.01
<0.01
80
3.2
<0.010
4.9
0.16
0.0026
<0.05
0.11
<0.001
5.7
<0.01
110
20
30
0.03
4/5/73
River
.Intake
NA
NA
NA
NA :
NA
1A
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.2
0.04
0.005
<0.1
<0.01
<0.001
23
5
<0.005
180
0.03
<0.01
78
2.4
<0.010
5.1
0.12
<0.0002
<0.05
0.18
0.001
5.6
<0.0l
120
15
25
0.02
7/23/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
.NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
0.9
0.01
0.010
<0.1
<0.01
<0.001
30
6
<0.005
210
0.01
<0.01
93
1.8
<0.010
4.4
0.05
0.0021
<0.05
0.10
- :
5.3
<0.01
130
10
36
0.02
10/1/73
River
Intake
NA
NA
NA
NA
NA
NA
NA-
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA-
NA
NA
NA
NA
NA
NA
NA
NA
NA
f* Pond
Discharge
4.1
0.06
0.050
<0.1
<0.01
0.01
200
8
0.026
750
<0.01
<0.01
520
1.1
0.012
4 = 8
0.07
<0.0002
<0.05
0.36
0.056
3.7
<0.01
630
46
350
0.09
NA = Not Available
-------
Table A-4 (Continued)
fVA.PLANT B RIVER WATER INTAKE AND BOTTOM ASH POND DISCHARGE DATA
(Quarterly Samples)
U1
N>
o\
Date 2/12/74
River Pond
IgjgKg Discharge
Aluminum, mg/1 1.6 3.7
Ammonia as N, mg/1 0.04 0.08
Arsenic, ag/1 <0.005 0.010
Barium, mg/1 " <0.1 <0.1
Beryllium, mg/1 <0.01 <0.01
Cadmium, mg/1 <0.001 <0.001
Calcium, mg/1 19 37
Chloride, mg/1 4 8
Chromium, mg/1 <0.005 <0.005
Conductivity, 25°C, umhos/cm 150 300
Copper, mg/1 X0.01 0.04
Cyanide, mg/1 - <0.01
"Hardness, mg/1 67 120
Iron, mg/1 0.9 8.0
Lead, mg/1 0.010 <0.010
Magnesium, mg/1 4.7 7.0
Manganese, mg/1 0.06 0.54
Mercury, mg/1 <0.0002 <0.0002
Nickel, mg/1 <0.05 <0.05
Phosphorous, mg/1 - 0.12
Selenium, mg/1 0.001 0.014
Silica, mg/1 7.2 6.7
Silver, mg/1 <0.01 <0.01
Solids, Dissolved, mg/1 90 190
Solids, Suspended, mg/1 14 48
Sulfate, mg/1 12 71
Zinc, mg/1 0.02 0.24
5/15/74
River
Intake
1.0
0.05
<0.005
<0.1
<0.01
<0.001
22
4
<0.005
150
0.04
«
76
0.47
<0.010
5.0
0.04
0.0009
<0.05
0.03
X0.002
5.1
<0.01
90
4
11
<0.01
4/8/74
Pond
Discharge
8.6
0.31
<0.005
0.3
<0.01
0.004
120
11
<0.005
960
0.18
<0.01
390
30
0.048
21
3.6
<0.0002
0.14
0.08
<0.002
22
<0.01
710
78
470
0.55
8/13/14
River
Intake
0.6
0.06
<0.005
<0.1
<0.01
<0.001
22
6
<0.005
170
<0.01
-
77
0.44
<0.010
5.0
0,1
<0.0002
<0.05
0.04
<0.002
4.8
<0.01
100
7
14
0.01
Pond
Discharge
,NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
11/12/74
River
Intake
0.2
0,04
<0.005
<0.1
<0.01
0.002
19
7
<0.005
-
<0.01
-
69
0.36
<0.010
5.2
0.05
<0.0002
<0.05
0.02
<0.002
4.6
<0.01
_
_
14
<0.01
10730/74
Pond
Discharge
0.4
0.12
<0.005
<0.1
<0.01
0.001
16
8
0.020
220
0.04
-
57
1.1
<0.010
4.2
0.04
<0.0002
<0.05
0.04
<0.002
, 4.8
<0.01
120
4
22
0.06
NA = Not Available
-------
Table A-4 (Continued)
TVA PLANT B RIVER WATER INTAKE AND BOTTOM ASH POND DISCHARGE DATA
(Quarterly Samples)
'Ln
NJ
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
2/4/75
River
Intake
A.
0.08
<0.0005
-
-
<0.001
17
6
<0.005
160
0.02
-
57
0.32
-
3.6
0.06
<0.0002
-
0.02
<0.002
5.6
-
100
12
18
0.04
1/15/75
Pond
Discharge
1.2
0.04
<0.0005
<0.1
<0.01
<0.001
30
8
0.008
250
0.20
<0.01
93
2.1
0.042
4.5
0.13
<0.0002
<0.05
0.03
<0.002
6.9
<0.01
140
23
35
0.12
5/19/75
River
Intake
0.4
0.08
<0.005
<0.1
<0.01
0.003
20
4
<0.005
150
<0.01
-
67
0.68
<0.010
4.5
0.04
<0.0002
<0.05
0.02
<0.002
3.2
<0.01
90
8
9
<0.01
4/21/75
Pond
Discharge
1.4
0.06
<0.005
<0.1
<0.01
<0.001
17
5
0.012
190
0.03
-
60
2.5
0.024
4.3
0.09
0.042
<0.05
0.03
<0.002
6.1
<0.01
120
13
26
0.11
8/5/75
River
Intake
0.5
0.05
<0.005
<0.1
<0.01
0.01
-
7
<0.005
-
0.02
-
-
0.38
<0.010
-
0.08
<0.0002
<0.05
0.02
<0.002
5.6
<0.05
90
9
10
0.02
7/14/75
Pond
Discharge
0.6
0.05
<0.005
0.1
<0.01
0.001
26
6
<0.005
160
0.08
-
85
2.2
<0.010
4.9
0.08
<0.0002
<0.05
0.04
X0.002
4.5
<0.01
120
16
20
0.12
11/4/75 10/14/75
River Pond
Intake Discharge
0.7
0.04
0.005
<0.1
<0.01
0.002
16
7
<0.005
140
<0.01
56
0.37
<0.010
3.8
0.06
<0.0002
<0.05
0.01
<0.002
4.8.
<0.01
95
5
10
<0.01
0.5
<0.01
0.008
<0.1
<0.01
<0.001
23
7
<0.005
190
0.06
79
1.7
<0.010
5.2
0.09
0.0002
<0.05
0.03
<0.002
5.0
<0.01
110
2
25
0.03
-------
fable A-5
TVA PLANT C RIVER WATER INTAKE AND COMBINED ASH POND (EAST) DISCHARGE DATA
(Quarterly Samples)
m
N>
00
Date
Aluminum, rag/1
Ammonia as N, rag/1
Arsenic, «g/l
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
, NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.8
0.23
0.008
<0.1
<0.01
0.002
45
8
<0.005
380
0.01
<0=01
140
2.0
<0.010
7.1
0,13
0.0025
<0.05
0.21
0.080
6.4
<0.01
260
17
120
0.09
4/3/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
3.8
0.12
0.010
0.2
<0.01
0.004
86
11
0.008
470
<0.01
<0,01
250
4.1
0.069
9.4
0.27
0.0006
<0.05
0.24
-
7.5
<0.01
310
37
130
0.08
7/3/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.7
0.09
0.015
0.1
<0.01
0.002
94
12
<0.005
430
0.02
<0.01
290
2.5
<0.010
14
0.16
<0.0002
<0.05
0.15
0.004
4.7
<0.01
300
25
110
0.10
9/30/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
0.3
0.04
0.050
<0.1
<0.01
0.003
100
16
<0.005
620
<0.01
<0.01
320
0.34
0.012
16
0.25
<0.0002
<0.05
0.21
<0.001
8.0
*'<0.01
460
4
170
0.02
NA » Not Available
-------
Table A~5 (Continued)
4
TVA PLANT C RIVER WATER INTAKE AND COMBINED ASH POND (EAST) DISCHARGE DATA
(Quarterly Samples)
m
10
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, rag/1
Conductivity, 25°C, umhos/etn
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/15/74
River
Intake
1.4
0.28
0.010
0.1
<0.01
<0.001
15
9
0.041
170
0.22
_
65
14
0*032-
6i88
02344
<0.0002
0.05
0.49
0.004
7.1
<0.01
170
38
48
0.13
Pond
Discharge
2.4
0.23
0.005
0.2
<0.01
0.010
80
9
0.008
510
<0.01
<0.01
230
3.3
Oi024';
7*2?
Oi25
0.11
0.07
0.02
0.010
7.2
<0.01
330
32
190
0.25
4/9/74
River
Intake
3.7
0.03
<0.005
0.2
<0.01
<0.001
29
12
<0.005
310
0.12
„
no
3.7
0102*
9i4
Oil 2
<0.0002
<0.05
0.28
<0.002
7.9
<0.01
160
32
44
0.08
Pond
Discharge
1.1
0.02
0.010
0.4
<0.01
0.010
70
12
<0.005
560
0.10
<0.01
180
1.6
<0.010
U4
0.34
0.0074
<0.05
0.02
<0.002
8.7
<0.01
350
22
190
0.22
7/16/74
River
Intake
4.9
0.12
<0.005
0.2
<0.0.1
<0.001
28
10
<0.005
300
0.15
-
110
6.1
0.022
9.8
0.38
0.0016
<0.05
0.29
<0.002
- —
<0.01
200
31
40
0.03
Pond
Discharge
1.9
0.08
0.005
0.3
<0.01
0.006
83
10
<0.005
580
0.07
<0.01
250
2.7
0.020
11
0.18
<0.0002
<0.05
' -
<0.002
-
<0.01
-
24
160
0.11
10/18/74
River
Intake
1.9
0.29
<0.005
0.2
<0.01
X0.001
38
16
0.016
410
0.06
_
150
2.4
0.010
14
0.53
<0.0002
<0.05
0.06
<0.002
5.4
<0.01
240
39
52
0.06
Pond
Discharge
0.3
0.07
<0.005
0.1
<0.01
0.004
100
15
<0.010
600
0.04
• -
310
0.33
0.020
14
0.19
<0.0002
<0.05
<0.01
<0.002
6.5
0.03
400
3
170
0.00
-------
Table A~5 (Continued)
TVA PLANT C RIVER WATER INTAKE AND COMBINED ASH POND (EAST) DISCHARGE DATA
(Quarterly Samples)
Ul
Date
Aluminum, mg/1
Ammonia as N, rag/1
Arsenic, mg/1 '-•.•«$' -rf;!
Barium, mg/1 *
Beryllium, iag/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/oa
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, ng/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended,
Sulfate, mg/1
Zinc, mg/1
1/14/75
River
Intake
Mti • 'f
f' 15;-; f
•• ^0;;-^3
<0.005
0.1
<0.01
<0.001
20
9
<0.005
20
0.03
-
80
13
0.028
7.4
0.26
<0.0002
<0.05
0.27
<0.002
5.6
<0.01
200
150
54
0.10
fond
Discharge
0.4
0.34
<0.005
0.3
<0.01
0.007
59
9
<0.005
480
0.04
<0.01
180
0.49
0.030
7.8
0.13
0.0220
0.05
0.02
<0.002
6.7
<0.01
320
5
180
0.14
4/8/75
River
Intake
<,'',:*£• Hi ~
I&-.5.
.OJ03
<0.005
<0.1
<0.01
0.002
17
7
0.013
200
0.13
_
69
10
0.047
6.5
0.29
<0.0002
<0.05
0.23
<0.002
5.8
<0.01
190
48
68
0.10
fond
Discharge
- .. ,
"••ko"
0.04
0.005
<0.1
<0.01
0.013
88
7
<0.005
480
0.09
-
250
1.4
0.021
7.0
0.17
No Bottle
<0.05
0.02
<0.002
7.8
<0.01
340
12
200
0.27
7/15/75
River
Intake
1.3
0.03
0.026
<0.1
<0.01
<0.001
43
11
0.009
360
0.10
-
160
1.4
<0.010
12
0.26
<0.0002
<0.05
0.10
<0.002
5.6
<0.01
220
17
34 *
0.08
Pond
Discharge
0.6
0.06
0.032
<0.1
<0.01
0.003
68
12
<0.005
5200
0.05
_
220
1.1
<0.010
13
0.14
<0.0002
<0,05
0.05
<0.002
11
<0.01
340
4
130
0.04
10/14/75
River
Intake
0.6
0.03
<0.005
<0.1
<0.01
<0.001
45
15
<0.005
400
0.09
-.
150
1.0
<0.010
10
0.29
<0.0002
<0.05
0.07
<0.001
5.5
<0.01
260
11
68
0.07
Pond
Discharge
1.4
0.05
0.010
<0.1
<0.01
0.002
66
16
<0.005
530
0.07
—
230
2.3
<0.010
15
0.14
<0.0002
<0.05
0.07
0.002
6.6
<0.01
380
25
140
0.07
-------
Table A-5 (Continued)
fVA PLANT C RIVER WATER INTAKE AND COMBINED ASH POND (EAST) DISCHARGE DATA
(Quarterly Samples)
Ul
Date
Aluminum, rag/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium| mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25 °C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1 •f-^-,^ .,:;• ,-,.;
Magnesium, mg/1) o s
Manganese, mg/1 : s}
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, rag/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/8/76
4/13/76
River
Intake
1.2
0.15
<0.005
<0.1
<0.01
<0.001
35
13
<0.005
300
. 0.09
120
3*7
<0.01Q
8v6v-.
0,09
<6*6oo2
<0.05
0.20
<0.002
7.3
<0.01
130
32
25
0.03
Pond
Discharge
1.2
0.20
0.010
0.2
<0.01
0.013
61
12
0.018
440
0.05
190
1.9
C0.010
9>5 * '
0.13
<0.0002
<0.05
0.57
<0.002
7.1
<0.01
310
20
130
0.33
River
Intake
1.1
0.03
0.005
<0.1
<0.01
<0.001
24
8
<0.005
210
0.05
87
1.8
<0.010
6.6
0.10
<0.0002
<0.05
0.33
<0.002
10.0
<0.01
170
58
50
0.02
Pond
Discharge
2.3
0.06
<0.010
0.3
<0.01
0.010
43
9
<0.005
450
0.19
160
3.4
0.014
13
0.16
<0.0002
<0.05
0.05
<0.002
9.5
<0.01
300
18
140
0.23
-------
Table A-6
TVA PLANT C RIVER WATER INTAKE AND COMBINED ASH POND (WEST) DISCHARGE DATA
(Quarterly Samples)
u>
Date
Aluminum, rag/1
Ammonia as N, rag/1
Arsenic,
Barium^
'Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, rag/1
Chromium, mg/1
Conductivity, 25°C, umhoa/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/73
River
Intake
NA
NA
'iMf*
'm
*NA°S
NA
NA
NA
NA
NA.
NA
NA.
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
6.9
0.07
3 0.008
<6.!i
$.01
<6.ooi
26
8
<0.005
250
<0.01
<0.01
92
5.7
<0.010
6.6
0.15
0.0002
<0.05
0.57
<0.004
6.9
<0.01
170
57
70
0.16
4/73
River
Intake
NA
NA
;NA
ffi
-------
Table A-6 (Continued)
TVA PLANT C RIVER INTAKE AND COMBINED ASH POND (WEST) DISCHARGE DATA
(Quarterly Samples)
u>
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
iron,,' mg/1. } r
Magne'sfiuni 1' mg/1
y ./ <*"*. ,.•*•„*• • " •'' it**?s S~*£ *
Manganese, *mg-/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/15/74
River
Intake
1.4
0.28
0.010
0.1
<0.01
<0.001
15
9
0.041
170
0.22
-
65
14^-
C?'1)32
f&
0^34
<0.0002
0.05
0.49
0.004
7.1
<0.01
170
38
48
0.13
Pond
Discharge
6.6
0.18
0.010
0.1
<0.01
<0.001
19
10
0.014
230
<0.01
0.01
73
"748"'
tiidss
%6Y3<
olW^'
0.0003
<0.05
0.30
0.002
6.7
<0.01
180
27
80
0.15
4/9/74
River
Intake
3.7
0.03
<0.005
0.2
<0.01
<0.001
70
12
<0.005
310
0.12
„
110
WJ
oT62
Q-* "fi
f$/\ i'l O
<0.0002
<0.05
0.28
<0.002
7.9
<0.01
160
32
44
0.08
Pond
Discharge
2.4
<0.02
<0.005
0.3
<0.01
<0.001
26
11
0.010
320
0.12
<0.01
100
2'. 8
<0t010
8'. 9
0.07
0.0041
<0.05
0.13
<0.002
8.2
<0.01
170
29
50
0.14
7/16/74
River
Intake
4.9
0.12
<0.005
0.2
<0.01
<0.001
28
10
<0.005
300
0.15
-
110
6.1
0.022
9.8
0.38
0.0016
<0.05
0.29
<0.002
-.
<0.01
200
31
40
0.03
Pond
Discharge
1.6
0.11
0.11
0.2
<0.00l
0.002
27
10
<0.005
270
0.10
<0.01
100
2.0 "
0.024
9.0
0.11*
0.050
<0.05
_
<0.002
-
<0.01
_
19
42
0.11
10/8/74
River
Intake
1.9
0.29
<0.005
0.2
<0.01
<0.001
38
16
0.016
410
0.06
-
150
2.4
6.010
14
6.53
<0.0002
<0.05
0.06
<0,002
5.4
<0.01
240
39
52
0.06
Pond
Discharge
0.5
0.10
<0.005
0.1
<0.01
0.004
89
14
0.008
600
0.06
-
280
0.72
0.016
14
0.34
<0.0002
<0.05
0.02
<0.002
5.9
0.02
390
4
180
0.11
-------
Table A-6 (Continued)
TVA PLANT C RIVER WATER INTAKE AND COMBINED ASH POND (WEST) DISCHARGE DATA
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
m Chromium, mg/1
JpJ Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/i
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/14/75
River
Intake
15.0
0.33
W»
\- :Q\1f.tui,:
•<0;'OPV
-------
Table A-6 (Continued)
TVA PLANT C RIVER WATER INTAKE AND COMBINED ASH POND (WEST) DISCHARGE DATA
(Quarterly Samples)
Cn
t*>
Ul
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, rag/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Eea'd^Jing/l >. •/ 0 s ?
Magnesium, 'mg/1 <{)'01
Manganese, mg/l <0* I
Merely, mg7COO? <0°CH>~:
Nldcel, mg/1' 4" '>"•-.-
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/8/76
River
Intake
1.2
0.15
<0.005
<0. 1
<0.01
<0.001
35
13
<0.005
300
0.09
— '
120
3.7
<0.010
8.DJ
o;'09
-------
Table A-7
TVA PLANT D RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
Date
u>
"AwmoiJjLa,,as |}g, mg/1
vj* • •.*?tfr-V>,».U!mBiD!T
Barium^, -mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1,
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/2/73
River
Intake
NA j"1
liA0*^
if A10
NA?
NAlK
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
ltt- .
^p,Y§^'*
Btbi8
0.2,
<&dr.
0.001
37
5
<0.005
310
<0.01
<0.01
130
0.17
<0.010
9.0
0.04
0.001
<0.05
0.07
0.140
3.2
<0.01
200
8
84
0.01
4/2/73
River
Intake
•NA :
^A^1'^'
9P3
.^ .
"'NA;)' ''
NA
NA
NA
NA ,
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
.1.3" T
' HOi1''*"
bls025
6.2
O.Q50
3.8
<0.01
100
14
60
0.01
7/2/73
River
Intake
"NA
NA
NA" ':
NA;
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
.NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
0. 4
o.oi"
O."020
0.2
<0.01 !
<0.001
28
3
<0.005
210
0.01
<0.01
100
0.08
<0.010
7.8
0.01
0.0003
<0.05
0.06
0.050
1.0
<0.01
120
3
35
<0.01
10/1/73
River
Intake
NA
'$&.' "'
NA1'
NA*';
NA!
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
.NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.6
0.01
0.050
0.1
<0.01
<0.001
34
3
0.005
250
<0.01
<0.01
110
0.39
<0.010
8.9
0.02
<0.0002
0.19
0.15
0.056
5.0
<0.01
170
33
52
0.01
NA = Not Available
-------
Table A-7 (Continued)
TVA PLANT D RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
Date -
Aluminum, rag/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/i
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
m Chromium, mg/1
itj Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/15/74
River
Intake
0.9
0.01
<0.005
0.2
<0.01
<0.001
27
4
<0.005
150
0.22
-
100
1.00
0.016
8.4
0.10
0.0005
0.27
<0.01
0.004
3.8
<0.01
130
13
14
0.07
Pond
Discharge
0.3
0.14
0.010
<0.1
<0.01
<0.001
26
4
<0.005
920
<0.01
<0.01
96
0.14
X0.010
,7.5 •
0.05
<0.0002
0.05
<0.01
0.098
3.6
X0.01
160
7
70
<0.01
4/22/74
River
Intake
0.2
<0.01
<0.005
0,2
<0.01
<0.001
28
3
<0.005
200
0.03
-
100
0.41
<0.010
717
QJ03
<0'
-------
Table A-7 (Continued)
TVA PLAHT D RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
Ul
u>
00
Date
Aluminum, mg/1
Ammonia as N, mg/1 u ? »•• «
Arsenic, mg/1 $5 fugsi?,,;
Barium, mg/1 " }j'"°JT«3-i«»
Beryllium, mg/1 -'iqs r"
Cadmium, mg/1 ;! :•'
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
.Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, rag/1
Solids, Suspended, rag/1
Sulfate, mg/1
Zinc, mg/1
1/13/75
*
*
*
3
*
220
*
*
*
*
*
0
<0
4
*
140
55
18
*
.05
.002
.4
0.6
0.04
<0.005
0.1
<0.01
0.001 •
33
3
<0.005
280
0.01
<0.01
120
0.09
0.046
8.3
0.03
<0.0002
<0.05
0.02
0.130
3.3
<0.01
170
6
65
0.04
4/7/75
River
Intake
0.5
<;0it044<>.
8.2
v 04)2
-------
Table A-7 (Continued)
TVA PLANT D RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
Ol
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1 :; -',/ i
Magnesium, mg/1 n
Manganese, mg/;l!,
-------
Table A-8
TVA PLANT E RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
Ln
-^
O
Date
Aluminum, mg/1
Ammonia as N, rag/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/I
Mercury, mg/1
Nickel, rag/1
Phosphorous, mg/1
Selenium, mg/1
Silica, rag/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, rag/1
Sulfate, mg/1
Zinc, mg/1
1/4/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.5
0.07
0.005
0.1
<0.01
<0.001
230
8
0.015
1,200
<0.01
<0.01
580
0.17
<0.010
0.6
<0.01
0.0002
<0.05
0.06
0.008
5.0
<0.01
540
6
180
0.07
4/2/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
11
0.08
0.010
0.4
<0.01
0.002
340
6
0.026
1,400
<0.01
<0.01
850
3.6
<0.010
0.9
0.06
0.0002
<0.05
0.03
0.024
5.0
<0.01
680
150
230
0.11
7/3/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.9
0.07
0.010
0.2
<0.01
<0.001
210
5
0.027
950
0.01
<0.01
530
0.29
<0.010
0.5
<0.01
<0.0002
<0.05
0.04
0.010
6.2
<0.01
420
6
22
0.02
10/1/73
River
Intake
NA
NA
NA
NA
NA
•NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA -
NA
NA
Pond
Discharge
3.4
0.23
0.005
0.4
<0.01
<0.001
300
8
0.020
1,600
0.20
<0.01
800
0.20
<0.010
11
<0.01
<0.0002
<0.05
<0.03
0.016
5.7
<0.01
680
8
220
0.01
NA = Not Available
-------
Table A-8 (Continued)
TVA PLANT E RIVER WATER INTAKE AND COMBINED ASH FOND DISCHARGE DATA
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1 ,
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, rag/1
Zinc, mg/1
1/15/74
River
Intake
2.7
0.06
0.005
0.2
<0.01
<0.001
17
5
0.02
130
0.13
-
57
2.40
0.016
3.6
0.1
<0.0002
<0.05
0.08
<0.001
5.2
<0.01
80
9
15
0.08
Pond
Discharge
2.0
0.06
<0.005
<0.1
<0.01
1 <0.001
160
5
0.011
270
<0.01
<0.01
400
0.16
0.008
0.2
<0.1
<0.0002
<0.05
<0.01
0.020
5.6
<0.01
310
10
150
<0.01
4/9/74
River
Intake
3.2
0.06
<0.005
<0.1
<0.01
<0.001
19
5
<0.005
160
0.11
- '
61
0.94
<0.01
3.4
0.24
<0.0002
<0.05
0.08
<0.002
4.4
<0.01
90
27
20
0.08
Pond
Discharge
4.5
0.06
<0.005
0.4
<0.01
<0.001
200
6
0.039
1,500
0.10
<0.01
500
0.95
<0.010
0.3
0.02
<0.0002
<0.05
0.02
0.011
5.0
<0.01
580
37
170
0.08
7/16/74
liver
Intake
0.6
0.07
<0.005
0.2
<0.01
<0.001
17
6
-
160
0,06
_
58
-
0.024
3.9
0.05
0.0006
<0.05
0.05
-
_
<0.01
-
4
_
0.07
Pond
Discharge
1.3
0.05
<0.005
0.3
<0.01
0.003
64
4
- '
660
0.07
<0.01
160
-
0.068
1.1
<0.01
0.0003
<0.05
_
_
_
<0.01
_
23
-
0.07
10/16/74
River
Intake
0.5
-
0.005
<0.1
<0.01
0.001
20
9
<0.005
180
0.12
-
68
0.18
0.010
4.5
0.07
<0.0002
<0.05
0.09
<0.002
5.8
<0.01
110
2
12
0.05
Pond
Discharge
2.1
0.03
<0.005
0.3
X0.01
<0.001
' 98
9
0.017
670
0.10
-
250
0.20
0.012
0.3
0.02
-
<0.05
0.01
<0.002
6.9
<0.01
260
5
70
0.06
-------
Table A-8 (Continued)
TVA PLANT E RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
en
•P*
ro
Date
Aluminum, mg/1 , «,« >, i
Ammonia as N, ng/1 *,,„ , ,'Mjsf,,:f
Arsenic, mg/1 '[•.,--;,,e^--,i.:
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, ing/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/14/75
River
Intake
*( 4.3
\ 0. 07
'<0.'005
-------
Table A-8 (Continued)
TVA PLANT E RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
l_rt
-P-
U)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/em
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1 r, ^
Magnesium, nig|j:,(^
Manganese, mg7jl^("
Mercury, mg/11,-."
Nickel, mg/1 "
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1 j:'
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1 - ;
1/19/76
ft/12/76
River
Intake
2.1
0.13
<0.005
<0.1
<0.01
<0.001
22
7
<0,005
hos/cm 150
<0i01
69
0.45
<0.010
'"* ' 3 5 ''
'.i, '95';-; rAC/*'1'*'
'*;'.?*
-------
fable A-9
TVA PLANT F RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
01
DaCe
Aluminum, mg/1
.Ammonia as N, mg/1
Arsenic, mg/1
Barium, rag/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, nsg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/1/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.0
0.06
<0.005
<0.1
<0.01
<0.001
100
5
0.030
410
<0.01
<0.01
260
0.19
<0.010
3.1
<0.01
0.0009
<0.05
0.14
0.024
4.8
<0.01
320
1
140
0.03
3/28/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.2
0;03
0.005
<0.1
<0.01
<0.001
74
5
0.012
350
<0.01
<0.01
200
1.1
<0.010
2.7
0.04
<0.0002
<0.05
0.24
0.009
4.2
<0.01
230
20
120
0.01
7/13/73
River
Intake
NA
NA
NA
NA
NA .
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.8
0.06
<0.005
<0.1
<0.01
<0.001
140
4
0.059
650
<0.01
<0.01
350
<0.05
<0.010
0.3
<0.01
0.0003
<0.05
0.03
0.016
5.9
<0.01
390
2
180
<0.01
10/16/73
River
Intake
NA'
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.5
0.12
<0.005
0.3
<0.01
<0.001
140
6
0.040
700
0.02
<0.01
380
<0.05
<0.010
7.2
<0.01
0.0003
<0.05
0.03
0.010
7.6
<0.0l
380
2
230
<0.01
NA = Not Available
-------
Table A-9 (Continued)
TVA PLANT P RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
Ui
Date
Aluminum, rag/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1 ,
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide , mg/1
Hardness, mg/1
Iron, mg/1
Lead , mg/1 -, ;
Hagne'Sliimf fmjg/ 1
Mawg afte'sie , " ttg/ 1
Metetir.ys, Wg/8." H'§\J
Nictael' i - mg/ It \ r
Phosphorous, mg/1
Selenium, ng/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, ttg/1
Zinc, mg/1
2/27/74
River
Intake
3.6
0.03
<0.005
<0.10
<0.01
<0.001
26
4
<0.005
170
<0.01
-
81
1.1
<0i,010
4J«D
'Of«f)6
QW0033
<0i<05
0.10
<0.002
5.4
<0.01
90
26
20
0.18
1/28/74
Pond
Discharge
0.8
0.38
<0.005
<0.1
<0.01
<0.001
80
4
0.050
480
0.04
<0.01
200
0.11
<0.010
'2
<0>OJ:Vs»
-------
Table A-9 (Continued)
TVA PLANT F RIVER HATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
Date
Aluminum, rag/1 p'wVsoft
Ammonia as N, mg/1 wff'ji^w {
Arsenic, mg/1 "«
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
tn Chromium, mg/1
^ Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, ing/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/20/75
River
Intake
n-,^'\-i
•(-•* l-'i3\|-
;,r Oi'Q3j
<0.005
<0.1
<0.01
0.002
28
4
<0.005
220
0.05
-
86
1.1
0.052
3.8
0.07
<0.0002
<0.05
0.11
<0.002
4.1
<0.01
140
35
18
0.06
Pond
Discharge
1.5
0.30
<0.005
0.2
<0.01
<0.001
85
5
<0.005
780
0.08
<0.01
210
0.10
<0.010
0.3
<0.0i
<0.0002
<0.05
<0.01
0.010
5.8
<0.01
450
3
260
0.07
4/7/75
River
Intake
••0*'W> '
2;lCr "
0^0,5
<0*005
<0.1
<0.01
0.001
19
3
0.005
150
0.04
-
62
2.1
0.010
3.5
0.11
<0.0002
<0.05
0.10
<0.002
4.8
<0.01
130
42
22
0.06
Pond
Discharge
fk ' ''• !
0^9 ,r
0.42
<0.005
<0.1
<0.01
0.001
100
5
0.020
400
0.06
-
260
0.37
0.015
1.6
0.01
<0.0002
<0.05
0.03
0.008
3.9
<0.01
300
11
140
0.04
7/15/75
River
Intake
1.0
0.07
<0.005
<0.1
<0.01
<0.001
31
4
<0.005
190
0.08
-
96
0.97
<0.010
4.4
0.07
<0.0002
<0.05
0.17
<0.002
4.4
<0.01
110
27
23
0.13
Pond
Discharge
1.0
0.03
<0.005
<0.1
<0.01
<0.001
67
4
0.020
460
0.07
_
170
0.12
<0.010
0.7
0.01
<0.0002
<0.05
0.02
0.010
6.6
<0.01
270
4
120
0.14
10/14/75
River
Intake
<0.2
0.10
<0.005
<0.1
<0.01
0.001
30
4
<0.005
210
0.05
-
95
0.29
<0.010
4.9
0.07
<0.0002
<0.05
0.16
<0.001
3.5
<0.01
170
15
12
0.03
Pond
Discharge
1.4
0.06
0.040
<0.1
<0.01
<0.001
110
6
<0.005
660
0.04
_
280
0.10
0.010
0.6
0.01
<0.0002
<0.05
0.02
0.006
6.5
<0.01
430
4
160
0.02
-------
Table A~9 (Continued)
TVA PLANT F RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
Ul
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cni
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1 .»,..
Magnesium, mg/3-
Manganese, pg/1
Mercury , mg/1
Nickel, fflg/1""'"
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/13/76
River
Intake
0.6
0.07
<0.005
<0.1
<0.01
<0.001
35
4
<0.005
220
<0.01
-
100
0.73
<0.010
r&$
^.06
<0."0002
<0.05
0.09
<0.004
4.6
<0.01
120
21
17
0.02
Pond
Discharge
1.9
0.27
<0.005
0.2
<0.01
0.001
130
6
0.058
580
0.02
-
330
0.31
<0.010
0.?6
<0.:01
<0.0002
<0.05
0.02
<0.004
4.9
<0.01
390
53
220
0.06
4/13/76
River
Intake
1.3
0.03
<0.005
<0.1
<0.01
<0.001
29
4
<0.005
180
0.01
-
91
1.6
<0.010
4.4
0.08
<0.0002
<0.05
0.10
<0.002
4.9
<0.01
110
18
13
0.16
Pond
Discharge
1.0
0.11
<0.005
<0. 1
<0.01
<0.001
110
4
0.022
550
0.02
-
280
0.24
<0.010
1.0
0.01
<0.0002
<0.05
<0.01
0.005
5.6
<0.01
380
1
170
<0.01
-------
Table A-10
TVA PLANT G RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
ui
-P-
Date
1/4/73*
4/2/73*
7/2/73
River
Intake
NA
NA
NA
vUAjtfii
NA'O
NA?5
NA1"'^
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.1
0.38
0.004
/Ti Q* 4 ;
-------
fable A-10 (Continued)
TVA PLANT G 1IVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
vo
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, rag/1
Lead, m^/1 -
Magnesium, mg/1
Manganese, mg/d
MeVcury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/14/74
River
Intake
4.1
0.03
<0.005
0.1
<0.01
<0.001
21
3
-
140
0,16
69
4.6
0*04
mo
0^23
-------
fable A-10 (Continued)
TVA PLANT G RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
m
tn
o
Date
Aluminum, mg/1 -,..?, -,=.
Awionia as N, mg/1 ;-
Arsenic, ag/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide,, mg/1,
Hardness, mg/1
Iron, Bg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/13/75
River
Intake
!«: 1 j
0.7
0.01
<0.005
<0.1
-------
Table A-10 (Continued)
TVA PLANT G RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
u>
Ui
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, rag/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1 t •« ^^
Magnesium, mg/1:
Manganese, mg/1
Mercury, mg/1
Nickel, mg"/l "
Phosphorous, rag/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/7/76
River
Intake
0.7
0.02
<0.005
<0.01
<0.001
28
5
<0.005
160
0.02
88
0.78
-------
Table A-ll
TVA PLANT H RIVER HATER INTAKE AND COMBINED ASH FOND DISCHARGE DATA
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, ng/1
Barium, mg/1
Beryllium, »g/l
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
ui Chromium, mg/1
^2 Conductivity, 25 °C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness» mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/2/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.2
0.48
0.076
0.1
<0.0l
<0.001
39
12
<0.005
330
<0.01
<0.01
130
0.48
<0.010
8.1
0.07
0.0007
<0.05
0.40
<0.004
5.6
<0.01
200
5
85
0.01
4/2/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.9
0.16
0.070
0-2
<0.01
<0.001
46
15
<0.005
350
0.05
<0.01
150
1.4
<0.010
7.8
0.07
0.0016
<0.05
0.2L1
-
5.2
<0.01
240
19
45
<0.01
7/2/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.9
0.03
0.180
0.1
<0.01
<0.001
49
20
<0.005
380
<0.01
<0.01
150
0.24
<0.010
7.6
0.02
<0.0002
<0.05
0.62
0.014
2.7
<0.01
240
8
65
0.01
10/2/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.5
0.06
0.140
0.1
<0.01
<0.001
67
22
0.008
460
<0.01
<0.01
200
0.51
<0.010
8.8
0.03
<0.0002
<0.05
0.63 ,
0.024
3.6
<0.01
300
7
120
0.02
NA » Not Available
-------
fable A-ll (Continued)
TVA PLANT H RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
Ul
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
ui Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/14/74
River
Intake
1.2
0.11
0.01
<0.1
<0.01
<0.001
29
7
<0.005
220
0.15
-
100
1.4
0.040
7.3
0.14
0.0008
<0.05
0.06
0.006
6.0
<0.01
120
27
18
0.08
Pond
Discharge
1.4
0.16
0.055
<0.1
<0.01
<0.001
42
8
<0.005
350
<0.01
<0.01
130
0.88
0.030
6.2
0.07
0.0002
<0.05
0.06
0.014
5l3
<0.01
200
19
100
0.01
4/9/74
River
Intake
1.1
0.24
<0.005
0.2
<0.01
<0.001
26
9
<0.005
230
0.05
-
88
0.99
<0.010
5.7
0.10
<0.0002
<0.05
0.06
<0.002
6.6
<0.01
130
29
17
0.06
Pond
Discharge
1.1
0.03
0.035
0.3
<0.01
<0.001
42
10
<0.005
350
0.10
<0.01
130
0.70
<0.010
5.8
0.04
<0.0002
<0.05
0.04
0.004
5.5
<0.01
210
18
80
0.07
7/15/74
River
Intake
0.6
0.06
<0.005
0.2
<0.01
<0.001
23
9
<0.005
220
0.03
-
82
0.59
0.016
5.9
0.11
<0.0002
<0.05
0.06
<0.002
2.7
<0.01
110
22
16
0.05
Pond
Discharge
1.2
0.04
0.140
0.3
<0.01
XO.OOl
60
10
<0.005
440
0.04
<0.01
180
0.22
0.010
6.8
0.02
0.0012
<0.05
0.13
<0.002
-
<0.01
290
5
140
0.05
12/4/74
River
Intake
<0.2
0,15
<0.005
0.2
<0.01
<0.001
22
10
0.007
240
0.11
-
82
0.45
<0.010
6.5
0.10
0.0002
<0.05
0.06
<0.002
5.9
<0.01
130
10
20
0.10
Pond
Discharge
0.8
2.6
0.065
0.3
<0.01
0.001
34
16
0.010
400
0.14
-
120
0.64
<0.010
7.8
0.08
<0.0002
0.07
0.14
0.028
5.5
<0.01
220 . ,
4
70
0.15
-------
Table A-ll (Continued)
T7A PLANT H RIVER HATER INTAKE AND COMBINED ASH POND DISCHARGE DATA
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, rag/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, fflg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, iag/1
Sulfate, mg/1
Zinc, mg/1
1/14/75
River
Intake
0.8
0.42
<0.005
-------
Table A-12
TVA PLANT H RIVER WATER INTAKE AND FLY ASH POND DISCHARGE DA.
(Quarterly Samples)
Ui
m
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
'Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Coppers mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/14/76
4/12/76
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
'NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA.
NA
NA
NA
NA
Pond
Discharge
2.2
0.19
0.085
<0.1
<0.01
0.007
69 ._
11
0.011
440
0,02
- ,
200
0.80
<0.010
7.4
0.08
<0.0002
<0.05
0.09
0.019
5.9
<0.01
290
35
140
0.10
River
Intake
NA
NA
NA
NA
NA
NA
.. NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Dischai
2.2
0.1:
0.2,
<0.1
<0.0
0.0.
91
20
0.01
630
0.16
-
280
2.3
<0.01C
12
0.19
0.00'
<0.05
0.0$
—
4.9
<0.0
450
11
220
0.
-------
Table A-13
TVA PLANT H RIVER WATER INTAKE AND BOTTOM ASH POND DISCHARGE DATA
(Quarterly Samples)
Ul
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, rag/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm 260
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/14/76
River
Intake
*
0.27
<0.005
*
*
*
*
11
*
260
*
*
A
*
*
*
*
*
0.09
<0.002
6.5
*
150
23
20
*
Pond
Discharge
1.7
0.15
0.060
<0.1
<0.01
0.001
49
11
<0.005
340
<0.01
150
1.2
<0.010
6.1
0.04
<0.0002
<0.05
0.12
0.010
5.5
<0.01
210
35
59
<0.01
4/12/76
River
Intake
0.5
0.55
<0.010
<0.1
<0.01
<0.001
43
27
<0.005
390
0.03
150
0.53
0.013
9.3
0.14
<0.0002
<0.05
0.24
<0.002
2.3
<0.01
200
4
42
0.02
Pond
Discharge
0.9
0.18
NES
0.4
<0.01
<0«001
55
21
<0.005
420
<0.01
180
0.72
<0.010
11
0.06
<0.0002
<0.05
0.10
*
3.8
<0.01
260
2
100
<0.01
*Bottle Received Broken.
-------
Table A-14
TVA PLANT I RIVER WATER INTAKE AND COMBINED ASH POND (SOUTH) DISCHARGE
(Quarterly Samples)
Ul
Ul
Date
Aluminum, mg/1
Ammonia as N, rag /I
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, rag/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/3/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
HA
NA
NA
NA
NA
NA
NA ,
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
0.6
0.31
<0.005
0.1
<0.01
<0.001
110
11
0.016
610
<0.01
<0.01
280
0.05
<0.010
0.4
<0.01
0.0012
<0.05
0.05
<0.004
7.1
<0.01
280
3
60
<0.01
5/16/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge.
1.2
0.05
- •
0.2
<0.01
<0.001
99
6
0.006
540
0.02
<0.01
250
0.09
<0.010
0.2
0.01
<0.0002
<0.05
0.03
0.004
7.4
<0.01
230
2
50
0.24
7/9/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.6
0.05
0.005
0.1
<0.01
- - _
140
6
0.021
750
0.02
<0.01
350
0.09
-
0.4
<0.01
<0.0002
X0.05
0.06
0.004
7.0
<0.01
300
6
75
0.01
10/1/73 _
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.1
0.03
0.005
0.2
<0.0i
<0.001
100
7
0.026
680
<0.01
<0.01
250
<0.05
0.010
0.2
<0.01
<0.0002
0.05
<0.03
0.006
7.6
<0.01
300
3
64
0.03
NA - Not Available
-------
Table A-14 (Continued)
TVA PLANT I RIVER WATER INTAKE AND COMBINED ASH POND (SOUTH) DISCHARGE
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
yj Conductivity, 25°C, umhos/cm
00 Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Ironj mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, og/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
2/19/74
River
Intake
1.4
0.05
<0.005
0.2
<0.01
<0.001
21
4
<0.005
170
0.11
-
66
1.7
0.021
3.3
0.11
<0.0002
<0.05
0.15
0.002
5.6
<0.01
100
18
12
0.08
Pond
Discharge
0.8
0.03
<0.005
0.3
<0.01
<0.001
74
4
0.030
540
0.13
<0.01
190
0.15
<0.010
0.4
<0.01
<0.0002
<0.005
0,01
0.08
7.9
<0.01
220
4
61
0.07
4/8/74
Elver
Intake
2.0
0.08
<0.005
0.3
<0.01
<0.001
20
4
<0.005
150
0.10
_
64
1,8
0.014
3.3
0.12
<0.0002
<0.05
0.21
<0.002
5.9
<0.01
90
28
14
0.12
Pond
Discharge
1.1
0.06
<0.005
0.2
<0.01
<0.001
46
4
4
440
0.05
<0.01
120
0.28
<0.010
0.5
0.5
<0.0002
<0.05
0.04
0.007
7.8
<0.01
190
2
58
0.08
7/15/74
River
Intake
0.8
0.02
<0.005
0.1
<0.01
<0.001
18
6
<0.005
150
0.07
-
59
0.80
0.017
3.5
0.06
<0.0002
<0.05
0.04
<0.002
3.2
<0.01
90
16
10
0.09
Pond
Discharge
2.0
0.03
<0.005
0.2
<0.01
0.002
92
5
0.020
750
0.15
<0.01
230
0.25
0.038
0.3
<0.01
<0.0002
<0.05
<0.01
<0.002
-
<0.01
230
<1
90
0.09
10/15/74
River
Intake
1.2
0.04
<0.005
<0.1
<0.01
0.001
21
8
<0.005
180
0.12
_
70
0.61
0.016
4.3
0.01
<0.0002
<0.05
0.10
<0.002
_
<0.01
100
3
12
0.05
Pond
Discharge
2.6
0.03
<0.005
0.5
<0.01
<0.001
140
10
0.026
940
0.10
_
350
0.17
0.010
0.2
0.01
<0.0002
<0.05
<0.01
0.012
9.1
<0.01
370
2
100
0.08
-------
Table A-14 (Continued)
TVA PLANT I RIVER WATER INTAKE AND COMBINED ASH POND (SOUTH) DISCHARGE
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, rag/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
en Conductivity, 25°C, umhos/cm
*° Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/13/75
River
Intake
3.0
0.10
<0.005
<0.1
<0.01
<0.001
18
5
<0.005
130
0.01
-
56
3.9
0.014
2.7
0.20
<0.0002
<0.05
0.36
<0.002
6.4
<0.01
100
57
10
0.05
Pond
Discharge
1.4
0.06
0.010
<0.1
<0.01
<0.001
44
6
0.024
310
0.02
<0.01
120
0.35
0.012
2.0
0.02
<0.0002
<0.05
0.05
<0.002
6.3
<0.01
190
15
50
0.04
4/7/75
River
Intake
2.0
0.04
<0.005
0.3
<0.01
0.001
17
6
0.005
140
0.06
-
53
1.8
0.012
2.6
0.12
<0.0002
<0.05
0.15
<0.002
6.5
<0.01
100
16
20
0.11
Pond
Discharge
1.9
0.10
0.100
<0.1
<0,01
0.001
45
4
0.007
310
0.02
-
120
0.58
0.019
2.2
0.01
0.0005
<0.05
0.09
0.007
6.0
<0.01
210
, 7
70
0.06
7/14/75
liver
Intake
*
0.03
*
*
*
*
*
5
*
150
*
-
*
*
*
*
*
<0.0002
*
0.10
<0.002
4.4
*
90
20
11
* '
Pond
Discharge
2.1
0.01
0.110
<0.1
<0.01
<0.001
58
4
<0.005
330
0.09
-
160
0.47
<0.010
3.7
0.02
<0.0002
<0.05
0.25
0.008
6.0
<0.01
220
4
200
0.11
10/20/75
River
Intake
1.0
0.07
<0.005
<0.1
<0.01
<0.001
19
6
<0.005
150
0.04
-
61
1.5
<0.010
3.4
0.11
0.0003
<0.05
0.26
<0.001
5.9
<0.01
90
31
12
0.03
Pond
Discharge
1.2.
0.07
0.160
<0.1
<0.01
<0.001
61
7
<0.005
350
0.04
-
180
0.57
<0.010
3.5
<0.01
<0.0002
<0.05
0.24
0.005
6.2
<0.01
230
15,,.
88
0.10
*Bottle Broken
-------
fable A-14 (Continued)
1VA PLANf I RIVER WATER INTAKE AND COMBINED ASH POND (SOUTH) DISCHARGE
(Quarterly Samples)
Ul
m
o
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, Mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/12/76
River
Intake
1.1
0.07
<0.005
<0.01
<0.001
27
7
<0.005
150
<0.01
81
1.0
<0.010
3.2
0.07
<0.0002
<0.05
0.11
<0.002
6.3
<0.01
110
9
12
0.02
Pond
Discharge
3.4
0.20
0.035
<0.01
<0.001
59
6
0.012
310
<0.01
160
1.0
<0.010
3.6
0.01
<0.0002
<0.05
0.24
0.015
6.1
<0,01
200
48
59
<0.01
4/12/76
River
Intake
1.0
0.05
<0.005
<0.01
<0.001
26
5
<0.005
170
0.03
79
1.2
<0.010
3.4
0.09
<0.0002
<0.05
0.11
<0.002
5.0
<0.01
90
10
12
0.02
Pond
Discharge
0.4
0.07
0.010
<0.01
<0.010
140
6
0.006
880
<0.01
350
0.07
<0.010
0.5
0.01
<0.0002
<0.05
0.03
0.020
8.1
<0.01
360
15
120
0.06
-------
Table A-15
TVA PLANT J RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, rag/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/3/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
3.6
0.08
0.018
0.1
<0.01
0.002
30
3
0.006
360
0.05
<0.01
96
2.7
<0.010
5.0
0.66
0.0008
<0.05
0.15
<0.004
7.5
<0.01
210
2
140
0.04
4/3/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
5.0
0.04
0.014
<0.1
<0.01
0.001
31
3
<0.005
340
0.03
<0.01
100
3.4
<0.010
6.0
0.62
<0.0002
<0.05
0.03
0.003
7.9
<0.01
220
35
120
0.06
7/2/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
0.4
0.06
0.015
<0.1
<0.01
<0.001
39
4
<0.005
320
0.02
<0.01
130
0.66
<0.010
8.2
0.44
<0.0002
<0.5
0.04
0.002
5.7
<0.01
200
2
120
0.04
10/1/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.3
0.04
0.080
<0.1
<0.01
<0.001
57
4
0.005
380
0.02
<0.01
180
0.58
<0.010
9.3
0.16
<0.0002
<0.05
0.39
<0.001
5.6
<0.01
250
5
120
0.02
NA = Not Available
-------
Table A-1S (Continued)
TVA PLANT J RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE
(Quarterly Samples)
Ul
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/14/74
River
Intake
0.9
<0,01
•C0.005
<0.1
<0,01
<0.001
5
2
<0.005
44
oas
-
19
0.91
<0.01
U6
0.08
<0.0002
<0.05
<0.01
<0.002
4.1
<0.01
40
10
13
0.08
Pond
Discharge
7.6
0.05
0.025
<0.1
<0.01
<0.001
32
2
0.007
370
0.08
<0.01
100
9.4
0.028
5.7
0.68
<0.0002
<0.07
0.03
0.006
6.8
<0.01
250
81
170
0.09
4/4/74
liver
Intake
1.4
0.02
<0.005
0.4
<0.01
<0.001
4
2
<0.005
51
0.12
-
16
1.5
0.020
1.5
0.07
<0.0002
<0.05
0.03
<0.002
4.5
<0.01
40
35
13
0.09
Pond
Discharge
2.1
<0.08
<0.005
0.3
<0.01
<0.001
23
3
<0.005
250
0.18
<0.01
73
1.2
<0.010
3.9
0.40
<0.0002
<0.05
0.04
<0.002
6.5
<0.01
140
12
120
0.12
7/15/74
River
Intake
0.4
0.01
0.110
0.2
<0.01
<0.001
26
3
<0.005
320
0.04
-
95
0.44
<0.010
7.3
0.03
<0.0002
<0.05
0.02
0.008
1.0
<0.01
210
7
80
0.08
Pond
Discharge
1.0
<0.01
0.110
0.2
<0.01
<0.002
38
2
<0.005
320
0.05
<0.01
130
0.39
0.038
8.2
0.05
0.0005
<0.05
0.11
0.004
-
<0.01
200
9
90
0.03
10/8/74
River
Intake
0.3
0.01
<0.005
0.2
, <0.01
<0.001
30
4
0.006
240
0.04
-
110
0.26
<0,010
8.3
0.03
<0.0002
<0.05
0.02
<0.002
4.0
<0.01
130
5
14
0.05
Pond
Discharge
0.4
0.01
0.040
0.2
<0.01
<0.001
47
3
0.006
350
0.04
-
150
0.10
<0.010
8.6
0.08
<0.0002
<0.05
0.03
<0.002
3.5
<0.01
220
1
94
0.03
-------
Table A-15 (Continued)
TVA PLANT J RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25 °C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/15/75
River
Intake
0.6
0.02
<0.005
<0.1
<0.01
<0.001
4.0
2
<0.005
44
<0.01
-
15
0.50
0.18
1.2
0.06
<0.0002
<0.05
0.01
<0.002
3.9
<0.01
30
5
9
0.04
Pond
Discharge
4.4
0.04
0.005
0.2
<0.01
XO.OOl
29
2
<0.005
390
0.04
<0.01
94
5.2
0.014
5.3
0.79
<0.0002
<0.05
<0.01
<0.002
6.6
<0.01
210
9
180
0.11
4/8/75
River
Intake
1.0
0.23
<0.005
<0. 1
<0.01
<0.002
8.0
4
<0.005
90
0.06
-
30
0.61
0.011
2.4
0.18
<0.0002
<0.05
0.01
<0.002
4.8
<0.01
50
25
14
0.04
Pond
Discharge
3.0
3.7
<0.005
0.3
<0.01
<0.002
20
21
0.006
420
0.73
-
67
3.8
0.018
4.1
0.40
0.0004
0.08
0.08
<0.002
8.7
<0.01
170
9
140
0.25
7/14/75
River
Intake
1.0
0.02
0.007
<0.1
<0.01
<0.001
24
3
<0.005
200
0.11
-
89
1.1
<0.010
. 7.1
0.05
<0.0002
<0.05
0.02
<0.002
5.0
<0.01
110
7
16
0.03
Pond
Discharge
1.5
0.07
0.130
<0. 1
<0.01
<0.001
40
6
<0.005
310
0.05
-
140
0.86
<0.010
9.9
0.14
<0.0002
0.05
0.11
0.008
7.1
<0.01
200
4
72
0.02
10/15/75
River
Intake
0.3
0.03
<0.005
<0. 1
<0.01
<0.001
20
3
<0.005
160
0.09
-
76
0.28
0.010
6.4
0.06
0.0009
<0.05
0.03
<0.001
3.8
<0.01
100
7
13
0.04
Pond
Discharge
1.4
0.03
0.040
<0.1
<0.01
X0.001
25
3
<6.005
230
0.05
-"
85
0.52
<0.010
5.6
0.13
<0.0002
<0.05
0.07
0.007
4.7
<0.01
150
6
56
0.08
-------
Table A-15 (Continued)
TVA PLANT J RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE
(Quarterly Samples)
Ul
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Berylliums mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/7/76
River
Intake
0.4
0.01
<0.005
<0.1
<0.01
<0.001
6.0
3
0.014
48
0.01
20
0.45
<0.010
1.3
0.07
<0.0002
<0.05
0.01
<0.002
4.1
<0.01
40
4
10
<0.01
Pond
Discharge
1.5
0.04
0.090
0.1
<0.01
0.002
23
3
<0.005
230
0.03
70
3.2
<0.010
3eO
0.28
<0.0002
<0.05
0.09
0.004
5.6
<0.01
70
14
85
0.0.4
4/13/76
River
Intake
0.6
0.01
<0.010
<0.1
<0.01
<0.001
9.0
3
<0.005
74
0.05
32
0.84
<0.010
2.2
0.11
<0.0002
<0«05
0.02
<0.002
4.6
<0.01
50
6
18
<0.01
Pond
Discharge
1.3
0.07
0.100
<0.1
<0.01
0.0001
22
3
<0.005
NES
0.09
68
1.5
<0.010
3.2
0.32
0.0006
<0.05
0.03
0.004
6.2
<0.01
140
4
92
0.06
-------
Table A-16
TVA PLANT K RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/2/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.3
0.05
0.008
<0. 1
<0.01
<0.001
87
13
0.022
380
<0.01
<0.01
220
0.11
<0.010
1.0
<0.01
0.0008
<0.05
0.03
0.016
7.0
<0.01
220
7
72
0.11
4/2/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
1.9
0.03
<0.005
<0.1
<0.01
<0.001
110
9
0.015
520
<0.01
<0*01
280
0.34
<0.010
0.4
0.02
0.0003
<0.05
<0.03
0.008
7.4
<0.01
240
5
55
<0.01
7/2/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.3
0.16
-
0.2
<0.01
<0.001
130
13
0.023
580
<0.01
<0.01
330
0.17
<0.010
0.7
<0.01
0.0008
<0.05
0.06
0.008
8.8
<0.01
290
3
90
0.02
10/1/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
- Pond
Discharge
0.5
0.02
0.025
<0.1
<0.01
<0.001
75
19
0.023
480
0.03
<0.01
190
0.13
<0.010
1.1
<0.01
<0.0002
0.22
0.10
0.012
7.1
<0.01
310
6
88
0.02
NA = Not Available
-------
Table A-16 (Continued)
TVA PLANT K RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE
(Quarterly Samples)
Ul
o\
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, rag/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury,-mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/14/74
River
Intake
2.8
0.08
0.015
<0.1
<0.01
<0,001
15
6
0.027
140
0.12
_
52
2.6
0.022
3.6
0.09
<0.0002
<0.05
0.13
<0.002
5.3
<0.01
90
31
22
0.09
Pond
Discharge
1.8
0.06
0.010
<0.1
<0.01
0.001
77
11
0.014
500
0.07
<0,01
190
0.32
0.017
0.6
<0.01
<0.0002
<0.05
0.01
0.014
6.5
<0.01
240
10
89
0.08
4/8/74
River
Intake
2.3
0.04
<0.005
0.3
<0.01
<0.001
16
6
0.012
160
0.12
- .
56
2.2
<0.010
3.8
0.11
<0.0002
<0.05
0.10
<0.002
4.8
<0.01
100
26
18
0.08
Pond
Discharge
1.8
0.03
0.005
0.3
<0.01
<0.001
52
9
0.019
460
0.08
<0.01
130
0.33
<0.010
0.6
<0.01
0.0003
<0.05
0.01
0.012
8.0
<0,01
220
8
100
0.06
7/15/74
River
Intake
3.4
0.06
<0.005
0.2
<0.01
0.001
18
6
<0.005
150
<0.01
-
61
3.3
0.030
3.8
0.18
<0.0002
<0.05
0.06
<0.002
2.5
<0.01
80
60
13
0.04
Pond
Discharge
2.4
0.04
<0.005
0.2
<0.01
0.002
76
7
0.026
640
0.10
<0.01
190
0.33
0.040
0.5
<0.01
<0.0002
<0.05
<0.01
<0.002
-
<0.01
250
3
90
0.04
10/8/74
River
Intake
1.4
0.24
<0.005
0.1
<0.01
<0.001
28
10
0.006
260
0.04
-
98
1.3
<0.010
6.9
0.07
<0.0002
<0.05
0.08
<0.002
5.9
<0.01
150
30
31
0.06
Pond
Discharge
1.3
0.07
0.025
0.3
<0.01
<0.001
92
12
0.026
400
0.05
-
240
0.18
0.014
3.0
<0.01
<0.0002
<0.05
0.06
> 0.012
6.7
<0.01
240
5
110
0.05
-------
Table A-16 (Continued)
TVA PLANT K RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE
(Quarterly Samples)
Date
Aluminum, mg/1 "
Ammonia as N, mg/1
Arsenic , rag/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
0 Conductivity, 25 °C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese , mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/13/75
River
Intake
1.8
0.05
<0.005
<0.1
<0.01
<0.001
21
6
<0.005
160
0.02
-
66
1.8
0.020
3.4
0.10
<0.0002
<0.05
0.11
<0.002
5.6
<0.01
100
20
12
0.04
Pond
Discharge
3.1
0.08
0.045
0.3
<0.01
<0.001
60
8
0.036
350
0.02
<0.01
160
1.0
0.048
2.4
0.03
<0.0002
<0.05
0.06
<0.002
6.6
<0.01
210
26
60
0.04
4/7/75
River
Intake
2.6
0.43
<0.005
<0.1
<0.01
<0.001
12
4
0.009
120
0.08
_
40
2.2
0.010
2.5
0.07
<0.0002
<0.05
0.11
<0.002
5.0
<0.01
110
21
19
0.06
Pond
Discharge
1.7
0.10
0.050
<0.1
<0.01
0.001
47
7
0.009
320
0.03
-
130
0.37
0.012
2.4
0.01
<0.0002
<0.05
0.08
0.011
4.0
<0.01
240
7
88
0.02
7/14/75
River
Intake
1.1
0.06
0.024
<0.1
<0.01
<0.001
25
8
<0.005
200
0.11
-
87
1.4
<0.010
6.0
0.10
<0.0002
<0.05
0.09
<0.002
2.5
<0.01
120
23
23
0.11
Pond
Discharge
2.2
0.04
0.100
<0.1
<0.01
<0.001
64
6
0,015
340
0.01
-
180
1.2
<0.010
3.6
0.04
<0.0002
<0.05
0.17
0.009
5.3
<0.01
240
6
100
0.07
i
10/14/75
River
Intake
0.6
0.05
<0.005
<0.1
<0.01
<0.001
22
8
<0.005
150
0.09
-
73
0.66
<0.010
4.4
0.08
<0.0002
<0.05
0.09
<0.001
5.4
<0.01
100
17
21
0.06
Pond
Discharge
1.4
0.02
0.085
<0.1
<0.01
0.001
44
9
<0.005
300
0.09
-
120
0.18
0.010
3.0
0.01
i <0.0002
<0.05
0.12
0.008
5.8
<0.01
180
11
54
0.04
-------
Table A-16 (Continued)
TVA PLANT K RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE
(Quarterly Samples)
en
o\
oo
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/12/76
River
Intake
1.2
0.05
<0.005
<0.1
<0.01
<0.001
23
7
<0.005
150
<0.01
71
1.2
<0.010
3.4
0.07
<0.0002
<0.05
0.10
0.009
5.9
<0.01
100
22
16
<0.01
Pond
Discharge
1.4
0.11
0.060
<0.1
<0.01
<0.001
59
8
<0.005
320
<0.01
160
0.26
<0.010
3.0
<0.01
<0.0002
<0.05
0.06-
0.012
5.9
<0.01
200
4
59
<0.01
4/12/76
River
Intake
1.0
0.04
<0.010
<0.1
<0.01
<0.001
30
8
<0.005
210
0.03
96
1.7
<0.010
5.0
0.14
<0.0002
<0.05
0.13
<0.002
4.8
<0.01
110
24
24
0.04
Pond
Discharge
0.7
1.3
0.092
0.3
<0.01
<0.001
69
19
<0.005
370
0.04
180
0.20
<0.010
3.0
0.01
<0.0002
<0.05
0.02
0.003
5.6
<0.01
200
4
91
0.03
-------
Table A-17
TVA PLANT L RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/8/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.1
0.37
0.036
<0.1
<0.01
<0.001
44
6
0.009
120
<0.01
<0.01
130
0.90
<0.010
3.9
<0.01
0.0009
<0.05
0.19
<0.004
5.6
<0.01
230
11
100
0.04
4/2/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.2
1.3
0.030
0.1
<0.01
<0.001
38
4
0.007
270
<0.01
<0.01
110
1.0
0.043
4.0
0.06
0.0005
<0.05
0.03
0.013
5.0
<0.01
190
8
60
0.02
7/2/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Pond
Discharge
2.6
0.20
0.070
<0.1
<0.01
<0.001
91
6
<0.005
330
0.01
<0.01
240
0.54
<0.010
4.2
<0.01
-
<0.05
0.45
0.013
5.9
<0.01
240
3
75
0.03
10/1/73
River
Intake
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
.NA
NA
NA
JPond
Discharge
1.8
1.4
0.070
<0. 1
<0.01
<0.001
53
9
0.009
360
<0.01
<0.01
150
0.58
<0.010
3.5
<0.01
<0.0002
<0.05
0.42
0.014
5.4
<0.01
230
5
110
0.02
NA - Not Available
-------
Table A-17 (Continued)
TVA PLANT L RIVER WATER INTAKE AND COMBINED ASH POND DISCHARGE
(Quarterly Samples)
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
<_n Chromium, mg/1
Q Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/15/74
River
Intake
2.8
0.04
<0.005
0.1
<0.01
<0.001
14
4
0.021
110
0.14
-
50
2.40
0.02
3.7
0.12
0.0002
<0.05
0.01
<0.002
5.2
<0.01
80
30
11
0.08
Pond
Discharge
2.0
0.60
0.045
<0.1
<0.01
<0.001
60
4
0.005
300
0.07
<0.01
160
0.87
<0.010
2.0
<0.01
<0.0002
<0.05
0.01
0.014
5.2
<0.01
220
27
80
0.02
4/9/74
River
Intake
2.3
0.05
<0.005
0.2
<0.01
<0.001
17
4
<0.005
130
0.10
-
56
1.9
0.012
3.4
0.08
<0.0002
<0.05
0.06
<0.002
5.4
<0.01
80
43
15
0.07
Pond
Discharge
2.5
0.46
0.010
0.2
<0.01
<0.001
72
4
0.010
560
0.08
<0.01
190
0.85
<0.010
1.3
0.01
0.0002
<0.05
0.02
0.008
6.7
<0.01
230
50
90
0.06
7/16/74
River
Intake
0.7
0.07
<0.005
0.2
<0.01
<0.001
17
6
<0.005
170
0.04
-
60
0.61
0.014
4.3
0.05
<0.0002
<0.05
0.02
<0.002
3.6
<0.01
90
8
14
0.04
Pond
Discharge
2.2
0.06
0.015
0.2
<0.01
0.004
47
6
0,010
310
0.14
<0.01
130
0.38
0.036
2.6
<0.01
<0.0002
<0.05
0.08
<0.002
-
<0.01
230
9
110
0.05
10/22/74
River
Intake
0.3
0.08
0.010
<0.1
<0.01
<0.001
17
8
0.010
180
<0.01
-
61
0.28
<0.010
4.4
0.03
<0.0002
<0.05
0.04
<0.002
5.1
<0.01
100
4
14
0.05
Pond
Discharge
1.3
0.73
0.010
<0.1
<0.01
<0.001
32
8
0.012
270
<0.01
_ .
92
0.41
<0.010
3.0
<0.01
<0.0002
<0.05
0.05
£0.002
-5.3
0.01
150
4
55
0.05
-------
Table A-17 (Continued)
TVA PLANT L RIVER INTAKE AND COMBINED ASH POND DISCHARGE
(Quarterly Samples)
Ul
•xj
Date
Aluminum, mg/1
Ammonia as N, mg/1
Arsenic, mg/1
Barium, mg/1
Beryllium, mg/1
Cadmium, mg/1
Calcium, mg/1
Chloride, mg/1
Chromium, mg/1
Conductivity, 25°C, umhos/cm
Copper, mg/1
Cyanide, mg/1
Hardness, mg/1
Iron, mg/1
Lead, mg/1
Magnesium, mg/1
Manganese, mg/1
Mercury, mg/1
Nickel, mg/1
Phosphorous, mg/1
Selenium, mg/1
Silica, mg/1
Silver, mg/1
Solids, Dissolved, mg/1
Solids, Suspended, mg/1
Sulfate, mg/1
Zinc, mg/1
1/21/75
River
Intake
1.0
0.05
<0.005
<0.1
<0.01
<0.001
13
6
0.012
150
0.02
-
46
0.84
0.018
3.4
0.07
<0.0002
<0.05
0.03
<0.002
5.1
<0.01
90
12
16
0.06
Pond
Discharge
1.5
0.45
0.033
<0.1
<0.01
<0.001
42
8
0.018
410
<0.01
<0.01
120
0.48
<0.010
2.7
0.13
<0.0002
<0.05
0.03
0.020
4.5
<0.01
260
11
6
0.04
4/15/74
River
Intake
1.4
0.06
<0.005
0.2
<0.01
<0.001
15
4
0.005
140
0.06
-
53
1.1
0.032
3.7
0.07
<0,0002
<0.05
0.03
<0.002
5.8
<0.01
70
9
12
0.09
Pond
Discharge
2.3
0.29
0.035
0.2
<0.01
0.002
42
4
0.016
320
0.12
-
110
0.30
0.031
1.8
0.07
<0.0002
<0.05
-
0.013
7.1
<0.01
180
7
100
0.06
7/9/75
River
Intake
0.7
0.07
<0.005
<0.1
<0.01
0.001
21
7
<0.005
150
0.08
_
70
0.66
<0.010
4.2
0.07
<0.0002
<0.05
0..04
<0.002
5.0
<0.01
90
5
9
0.03
7/16/75
Pond
Discharge
2.1
0.29
0.030
<0.1
<0.01
<0.001
63
5
<0.005
360
0.10
-
160
0.36
<0.010
1.4
0.01
<0.0002
<0.05
0,04
0,010
9.1
<0.01
230
3
110
0.03
10/14/75
River
Intake
0.7
0.04
<0.005
<0.1
<0.01
< 0.001
19
7
<0.005
150
0.08
_
64
0.45
<0.010
4.0
0.04
<0.0002
<0.05
0.04
<0.001
5.3
<0.01
100
4
9
0.07
Pond
Discharge
1.7
0.14
0.005
<0.1
<0.01
<0.001
62
4
<0.005
420
0.09
—
160
<0.05
0.010
0.4
<0.01
<0.0002
<0.05
0.02
0.010
8.5
<0.01
140
3
67
0.02
-------
, APPENDIX B
CHLORINE MINIMIZATION PROGRAM
FOR ONCE-THROUGH COOLING WATER
572
-------
APPENDIX B
CHLORINE MINIMIZATION PROGRAM
FOR ONCE-THROUGH COOLING WATER
PURPOSE
The purpose of chlorine minimization is to reduce the
discharge of chlorine or its related compounds to receiving
waters. This description is intended to explain what a chlorine
minimization program is and how to develop and implement one.
Anticipated situational factors and how to approach them are also
presented.
BACKGROUND
Chlorine is commonly added to condenser cooling water
of steam electric facilities in order to control the growth of
various organisms (algae, bacteria, barnacles, clams) that would
otherwise attach to surfaces in the condenser, cooling towers, or
to other components of the cooling system and prevent the system
from functioning properly.
The attachment of these various organisms to the cool-
ing water system is called biofouling. Since the control method
using chlorine involves creating a residual dose of reactive
chlorine, some of the chlorine used to control biofouling is
Still present when the cooling water is discharged from the
plant. It is desirable to minimize the discharge of free and
combined residual chlorine from steam electric powerplants due to
the toxicity these compounds have on aquatic life.
573
-------
Various powerplants have undertaken some type of pro-
gram to reduce the use of chlorine. The results of these pro-
grams indicate that significant chlorine reduction can be
achieved in many cases. Some of the plants found that chlorina-
tion is not required at all while others have found that the
amount of chlorine added can be significantly reduced, especially
during the winter months.
GENERAL APPROACH
In order to determine the minimum amount of chlorine a
specific powerplant requires, a chlorine minimization study must
be undertaken. A chlorine minimization study may require up to
eighteen months. The first step is the selection of the most
appropriate minimization strategy, which may take up to six
months. During this period, each of the following three vari-
ables is controlled at various levels until the minimum value
that permits- proper plant performance is determined:
1. Dose of chlorine added - where dose is defined as
the total amount of chlorine added per unit volume
of cooling water.
2» Duration of chlorine addition - where duration is
defined as the length of time between the start
and end of a single period of chlorine addition.
3« Frequency of chlorination - where frequency is
defined as the number of periods of chlorine addi-
tion per day or week.
During the trials of various combinations of dose,
duration, and frequency, data on plant performance must be
574
-------
collected.*- These data may include condenser vacuum, generator
output, and the cooling water temperature rise as well as pres-
sure drop across the condenser. The performance data can be
analyzed to determine if proper plant performance is being
maintained. Different plants will necessarily employ different
measures of performance to ensure that conditions specific to
that plant are taken into account. Starting from operational
practices known to maintain satisfactory performance of the cool-
ing system, the systematic approach described in the following
sections would be used to select the optimum chlorine minimiza-
tion strategy. This optimum strategy determines the manner in
which dose, duration, and frequency are best varied to maintain
system performance.
After the optimal minimization strategy has been deter-
mined, a full year of application of the optimal strategy is
required to define the minimum dose and duration as well as
optimum frquency to be used during any portion of the year. The
optimal chlorination procedure will vary with the seasons o£ the
year due to changes in the chemical, physical, and biological
characteristics of the cooling water source. Water temperature
is an especially important variable, as the growth rate of many
microorganisms drops rapidly with decreasing water temperature.
Therefore, many plants have found they do not need to chlorinate
at all during the winter months.
At the end of a full year of study, the proper chlori-
nation procedure for each season of the year will have been
defined and the chlorine minimization program will officially
cease. At this point, the proper chlorination procedure is based
upon the data collected during the previous years program. Sys-
tem performance data must still be collected periodically to
check the adequacy of the procedure and to enable any needed
changes to be made.
575
-------
It Is important to mention that plants have^ some addi-
tional ways of reducing chlorine use besides conducting a formal
minimization program. For example, chlorine need not always be
applied to the entire cooling system. Although biological growth
occurs in all segments of the cooling system, the most sensitive
portion is usually the condenser. Biological growth in the other
segments does not generally impair the operation and efficiency
of the plant with the exception of plants with encrustations of
macroinvertabrates (barnacles, clams) in the intake system. The
relocation of the point of chlorine addition to the condenser
inlet box, providing sufficient mixing of chlorine occurs, can
result in significant reduction in the quantity of chlorine
required to achieve the necessary level of free available chlo-
rine at the condenser outlet. Chlorine addition, however, is
required in the cooling water intake structure and other sections
of the cooling system for plants with macroinvertabrate fouling
problems. Most experience has demonstrated that the continuous
application of chlorine is necessary to gain control of both
larval and adult forms of the macroinvertabrates where they occur
on the intake structure, intake tunnels, and intake water boxes.
Chlorine minimization in such instances involves applying chlo-
rine only during the growing season and at the Ipwest concentra-
tions necessary to achieve control. Visual inspection is the
most usual and reliable method of measuring the chlorine effec-
tiveness. For new facilities, the option of utilizing heat
treatment to resolve this problem should be explored.
Another method of reducing chlorine use that falls out-
side the scope of a. formal minimization program is the use of a
mechanical condenser antifouling device (mechanical cleaning).
Some plants using on-line mechanical cleaning do not chlorinate
at all; others still require chlorine addition to the critical
576
-------
components of the cooling system. For existing plants, the
retrofitting of a mechanical cleaning system may be expensive.
For new plants, costs of a mechanical cleaning system are lower
since no retrofit is needed. New plants should seriously con-
sider the use of a condenser mechanical cleaning system.
SYSTEMATIC APPROACH FOR DETERMINING MINIMUM AMOUNT OF
CHLORINE ADDITION
As explained in the preceeding discussion, the control
variables are dose, duration, and frequency. During the optimal
strategy development stage, these factors must be varied in a
systematic fashion. Throughout this period the operating inte-
grity of the plant must be protected. To accomplish this, plant
operators will need to establish some absolute means of monitor-
ing condenser performance. : If at all possible; | provisions should
be made to enable visual inspection of the gon^enser elements
following a test period. The actual condition e-f the system in
- ' ",-•' I- -V?* £. W
terms of biofouling can then be directly conrpared to the indirect
means of monitoring performance (condenser v§SUum» pressure drop,
etc.)- Actual inspection of the condenser or pj'her part of the
cooling system (which requires plant closure 0,5 loading reduc-
tion) should not be considered to be a 'roofing' method of eval-
uating the effectiveness of the chlorine addition program as unit
downtime to make such inspections is costly and highly undesira-
ble from the operator's standpoint.
The following sections provide additional details con-
cerning; (1) the specific things each plant must be capable of
in order to conduct a minimization program, (2) the specific
steps that make up a minimization, program, and (3) how a plant
should use the results of a minimization program to control
future chlorine use.
577
-------
1 • Required Capabilities . • j ^
a. A means of measuring the apparent waterside
condenser tube fouling. This should include
visual inspections and biofouling sampling at
some point, in the test program. Inspection
should include the condenser txibes, intake tube
sheet, water boxes and, if needed, the cooling
water intake structure. Other measurements may
be substituted with caution such as deviation
from expected condenser vacuum, pressure drop,
etc. The substitute measurements all have
serious problems of ambiguity since many
factors - other than biofouling film growth in
the condenser tubes can affect these
measurements .
v bus. ...
b. A meanslx'of. relating the periodic inspection
result or other measurements to condenser
performance.
j:3?fs_.-i _:'
c. A means of gathering grab samples from con-
denser inlet, outlet, and NPDES discharge
pointi TT-i
d. A means of measuring free available chlorine
(FAC)'and total residual- chlorine (TRC) on
samples without delay once collected. The test
method to be employed is ASTM D 1253 Chlorine
in Water, Method A, Direct Amperometric
Titration .
578
-------
e. A means of controlling and measuring with
appropriate accuracy the addition of chlorine
to the cooling water to the unit or condenser
under study. The arrangement for adding
chlorine varies considerably from plant to
plant. The physical differences may influence
the minimization strategy and may require
physical modification of the existing system in
order to properly implement the program.
* E' "7 - ;
f. General chemical analytical capability for
properties or substances in water.-.
g. A means of determining short-termvfree avail-
able chlorine demand of the inletrnwater either
in the laboratory or by difference, between
applied chlorine concentration and the free
available chlorine residual fojind^iat the
condenser inlet. 70 si.
2. Specific Steps in a Minimization Program
'"'' O 8.S.E :
a. Establish a baseline of condenser performance
associated with the condenser for each seasonal
period of plant operation (winter, summer,
etc.). This may involve an initial-offline
chemical or mechanical cleaning;; : It is
necessary that these baseline conditions be
used to evaluate the results of :the various
chlorination strategies. Data needed to estab-
lish baseline conditions will be available at
most facilities, and thus, will not require a
delay in systematic testing of minimization
strategies.
579
-------
Conduct screening tests for a letigth of time to
be determined by plant operators. A period of
two months for each of the strategies tested is
probably appropriate. Different plant cooling
water and chlorine feed configurations may
require alterations in the selection of the
minimization strategies. Plants with several
units with similar tube metal, intake water,
transit times, temperature gradient across the
condensers and cooling water velocity may allow
parallel trials of the minimization strategies
on several units while maintaining other units
on the dose, frequency and duration found
effective in. past experience. The duration of
plant chlorination should be restricted to a
maximum of two hours per day.
.''SJLx/c-j:.
There are three basic ways to institute a
chlorine minimization program: (i) reduce the
dose, (ii)";areduce the duration, or (iii) change
the frequency;. • For many facilities it may be
desirablconduct all three alternatives in
successioiTrprior to selecting the most suit-
able. In some cases the operator can choose
one alternative based on previous experience.
The three: alternative approaches are explained
in detail as follows:
(i) Reduction of Dose: Establish a desired
outlet concentration for TRC. This
value should be lower than 0.14 mg/1.
Maintain the frequency and duration
580
-------
,m found effective in past experience but
reduce the dole of cht'Orine until the
desired effluent concentration is not
exceeded. Closely monitor condenser
performance parameters during this
period. If the system shows signs of
biofouling, increase the"dose. Test
periods of about two months should be
used for evaluating effectiveness of
each new dose used.
(ii)- Seduction of Duration: Decrease the
•duration of chlorine feed while
-• maintaining the dose and frequency found
effect i ve in •. pa s t exp er i enc e:.'.: • •
-------
applied in each season. Therfoptimum cpmbina-
tions for each season being those defined by
the chlorine minimization study during that
season. .Long term year to year variations in
water quality may require changes in dose,
duration, and frequency not encountered during
the minimization test program.
c. Monitoring of condenser performance indicators
(condenser vacuum, etc.) should continue during
the implementation plan. This is necessary to
prevent serious biofouling (and potential plant
shutdown) in the event that the influent
cooling water quality or plant operating
characteristics undergo a sudden change that
increases the plant's susceptibility to
f r"*: t
582
-------
Llfrom the £hort term screening tests, select
-r-r-3- --- -
the approach that appears to best fulfill
the purposes of the chlorine minimization
program. Using the selected strategy,
.-• : .';~s "•'••'"
conduct a year-long trial making- appropriate
adjustments in the dose, duraitbn, ""and
frequency to meet the changing'" intake water
chlorine demand and biofouling propensity so
as to maintain acceptable plant™ performance.
The entire test program, from start to finish,
••i'v "ij : ••'•'..
should not require more than 1 8 months .
.. i, rrs >'-'.:•>•:•;
3. Using the Results of the Minimization^ 'Program
a. The information obtained in the"fa month
chlorine minimization program®should serve as
the guidelines for a permanent chlorination
procedure. The most successful approach (the
method that provides for adequate plant
performance while minimizing chlorine
discharge) should be implemented.
b. The implementation program should take into
account both year-to-year and seasonal varia-
tions in water quality. For example, as was
done in the minimization program, each season
of the year should be approached as a new set
of operating conditions. Different combina-
tions of dose, duration and frequency may be
583
-------
APPENDIX C
STATISTICAL EVALUATION OF CHLORINE MINIMIZATION
AND DECHLORINATION
584
-------
APPENDIX C
STATISTICAL EVALUATION OF CHLORINE MINIMIZATION
AND DECHLORINATION
INTRODUCTION
Chlorine is one of the pollutants identified in the effluent of
steam .electric generating plants. It is used intermittently in
the cooling waters of generating stations to kill organisms which
interfere with the operation of a plant. Chlorine is added to
the cooling water in batches at such times as biofouling becomes
an operational problem. Because chlorination is a batch process,
chlorine in a plant's effluent is of concern only during and
immediately after the period of chlorination.
The effluent guidelines for steam electric plants are to include
standards for chlorine concentrations. Control options which may
be applied to reduce effluent chlorine concentrations include
chlorine minimization (use of the least amount of chlorine needed
without impairing operation of the plant) and dechlorination of
the effluent.
Three plants have provided data to EPA on chlorine concentrations
under no-control, minimization and dechlorination (where dechlo-
rination may include some level of chlorine minimization as well)
to the EPA. The purpose |