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ORGANIZATION OF THIS DOCUMENT
This development document for the nonferrous metals manufacturing
category consists of a general development document which
considers the general and overall aspects of the regulation and
31 subcategory specific supplements. These parts are organized
into 10 volumes as listed below.
The information in the general document and in the supplements is
organized by sections with the same type of information reported
in the same section of each part. Hence to find information on
any specific aspect of the category one would need only look in
the same section of the general document and the specific
supplements of interest.
The ten volumes contain contain the following subjects:
Volume I
Volume II
Volume III
General Development Document
Bauxite Refining
Primary Aluminum Smelting
Secondary Aluminum Smelting
Primary Copper Smelting
Primary Electrolytic Copper Refining
Secondary Copper Refining
Metallurgical Acid Plants
Volume IV Primary Zinc
Primary Lead
Secondary Lead
Primary Antimony
Volume V Primary Precious Metals and Mercury
Secondary Precious Metals
Secondary Silver
Secondary Mercury
Primary Tungsten
Secondary Tungsten and Cobalt
Primary Molybdenum and Rhenium
Secondary Molybdenum and Vanadium
Primary Beryllium
Primary Nickel and Cobalt
Secondary Nickel
Secondary Tin
Volume VIII Primary Columbium and Tantalum
Secondary Tantalum
Secondary Uranium
Volume VI
Volume VII
Volume IX Primary and Secondary Titanium
Primary Zirconium and Hafnium
Volume X Primary and Secondary Germanium and Gallium
Primary Rare Earth Metals
Secondary Indium
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DEVELOPMENT DOCUMENT
for
EFFLUENT LIMITATIONS GUIDELINES AND STANDARDS
for the
NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY
Volume I
General Development Document
William K. Reilly
Administrator
Rebecca Hanraer
Acting Assistant Administrator for Water
Martha G. Prothro, Director
Office of Water Regulations and Standards
A h
532
Thomas M. O'Farrell, Director
Industrial Technology Division
Ernst P. Hall, P.E. , Chief
Metals Industry Branch
and
Technical Project Officer
May 1989
U.S. Environmental Protection Agency
Office of Water
Office of Water Regulations and Standards
Industrial Technology Division
Washington, D.C. 20460
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GENERAL DEVELOPMENT DOCUMENT
FOREWORD
This foreword briefly describes the recent history of regulations
promulgated for this category and the litigation and subsequent
settlement agreements resulting from promulgation of the
rulemak i ngs.
Revised and expanded effluent limitations and standards for the
Nonferrous Metals Manufacturing Point Source Category were
promulgated in two separate rulemakings, sometimes referred to as
Phase I and Phase II, The category was divided into two phases
for regulatory convenience; this division was generally
consistent with Agency priorities of regulating first those
segments which generate the largest quantities of toxic
pollutants. The two finalized rulemakings and the three minor
amendments derived from settlement agreements are integral parts
of one regulation (40 CFR Part 421).
The Agency used the same overall approach in the development of
each rulemaking, however, certain assumptions were made specific
to each of the two phases. These assumptions, which are
described in this document, were based on the best data available
to EPA at the time each phase was developed.
EPA promulgated amendments to the nonferrous metals manufacturing
category (Phase I) on March 8, 1984 (49 PR 8742). Twelve
subcategories were addressed at that time:
1.
Primary Aluminum Smelting
2.
Secondary Aluminum Smelting
3.
Primary Copper Smelting
4 .
Primary Copper Electrolytic Refining
5.
Secondary Copper
6.
Primary Lead
7.
Primary Zinc
8.
Metallurgical Acid Plants
9.
Primary Tungsten
10.
Primary Colurabium-Tantalum
11.
Secondary Silver
12.
Secondary Lead
On September 20, 1985, EPA promulgated additional amendments for
the nonferrous metals manufacturing category (Phase II) (50 FR
38276). Twenty-five subcategories were addressed in this
amendment.
1. Bauxite Refining
2. Metallurgical Acid Plants (Molybdenum)
3. Primary Antimony
4. Primary Beryllium
5. Primary Boron
6. Primary Cesium and Rubidium
7. Primary and Secondary Germanium and Gallium
8. Secondary Indium
9. Primary Lithium
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GENERAL DEVELOPMENT DOCUMENT
10.
Primary Magnesium
11.
Secondary Mercury
12.
Primary Molybdenum and Rhenium
13.
Secondary Molybdenum and Vanadium
14 .
Primary Nickel and Cobalt
15.
Secondary Nickel
16.
Primary Precious Metals and Mercury
17.
Secondary Precious Metals
18.
Primary Rare Earth Metals
19.
Secondary Tantalum
20.
Secondary Tin
21.
Primary and Secondary Titanium
22.
Secondary Tungsten and Cobalt
23.
Secondary Uranium
24.
Secondary Zinc
25.
Primary Zirconium and Hafnium
After publication of the March 1984 amendments, twelve
petitioners filed petitions for judicial review of the
regulation. These challenges were consolidated into one lawsuit
by the United States Court of Appeals for the Fourth Circuit
(Kennecott v, EPA, 4th Cir. No. 84-1288 and Consolidated Cases).
On December 26, 1985 the court denied the petitions for review of
the primary lead, primary zinc, primary copper, metallurgical
acid plants, secondary lead and the columbiurn-tantalum
subcategories (780 P. 2d 445). The United States Supreme Court
denied two petitions for a writ of certiorari on October 7, 1986.
In November, 1985 four aluminum parties in the consolidated
lawsuits entered into two settlement agreements which resolved
issues raised by the petitioners related to the primary and
secondary aluminum subcategories. In accordance with the
Settlement Agreements, EPA published a notice of proposed
rulemaking on May 20, 1986 and solicited public comments on these
proposed amendments to 40 CFR Part 421 (50 FR 18530). EPA
promulgated these amendments (primary and secondary aluminum
subcategories) on July 7, 1987 (52 FR 25552).
On June 26, 1986 EPA entered into a Settlement Agreement with
AMAX, Inc. and intervenor GTE Products Corp., two petitioners
affected by the regulations for the Primary Tungsten Subcategory.
As a result of the settlement agreement, EPA proposed amendments
to the Primary Tungsten Subcategory regulation on January 20,
1987 ( 52 FR 2480 ) . After considering public comments on this
proposal, EPA promulgated these amendments on January 21, 1988
(53 FR 1704).
Ten petitioners challenged the September 1985 (Phase II)
amendments. The Agency has developed settlement agreements
resolving the complaints of six petitioners; three petitioners
have withdrawn their complaints and one complaint was made moot
when the Agency withdrew the BPT and BAT limitations for one
subcategory (primary rare earth metals). These settlement
agreements are the basis for amendments proposed April 28, 1989
(5 4FR18412).
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GENERAL DEVELOPMENT DOCUMENT
The five amendments of greatest significance to this document are
Proposal Promulgation
February 17, 1983 (48FR7032) March 8, 1984 (49FR 8742)
June 27, 1984 (49FR26352) September 20, 1985 (50FR38276,
May 20, 1986 (50FR18530) July 7, 1987 (52FR25552)
January 20, 1987 (52FR2480) January 21, 1988 (53FR1704)
April 28, 1989 (54FR18412)
In the preparation of this document, including the supplements,
the administrative records or court dockets have been used as the
primary source of data and information. Obvious errors have been
corrected and some substantial editing has been performed in some
areas, especially where it was necessary to protect information
claimed to be confidential by the firm that originally made the
information available. Additionally, supplements which were
originally prepared to support the March 8, 1984 and September
20, 1985 promulgations have been edited to reflect the most
recent amendments to the regulation. The supplements have also
been updated to reflect amendments to the regulations that would
be effective if the April 1989 proposed amendments are
promulgated without change.
The Agency has not substantially updated the information about
specific plants or processes. It is recognized that much of the
information was collected in the 1979 to 1983 period and that
time may have allowed changes to creep into the data. This is
unavoidable and should be taken into account when the data and
information are being used for some purposes. For most uses, the
data should be completely useful as it defines and clarifies the
technical basis for the nonferrous metals manufacturing effluent
limitations and standards.
In providing this technical basis for the regulation, the Agency
believes that it will be useful to industry and permit writing
authorities alike as it provides the best technical advice
relative to the effluent standards and limitations. In an effort
to provide this advice, the Agency has included a substantial
amount of technical data about the processes and raw wastewaters
within the processes. Where this data was available to the Agency
but is not provided, it has been withheld because of claims of
confidentiality. Additionally, where there were pollutants found
but not specifically regulated, the levels at which they would
have beer, regulated are shown to permit a ready technical
evaluation in situations where wastewater streams from different
categories or subcategories are combined for treatment: and
discharge.
Questions, comments, arid corrections for this document may be
addressed to The Er.vi ronmentai Protection Agency, Industrial
Technology Division (WK552), Washington, DC 20460.
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GENERAL DEVELOPMENT DOCUMENT
CONTENTS
Section Title Page
I Summary and Conclusions 1
II Recommendations 19
III Introduction 21
IV Industry Subcategorization 33
V Water Use and Wastewater Characteristics 39
VI Selection of Pollutant Parameters 49
VII Control and Treatment Technology 141
VIII Cost of Wastewater Treatment and Control 285
IX Effluent Quality Attainable Through Application 365
of the Best Practicable Control Technology
Currently Available
x Effluent Quality Attainable Through Application 391
of the Best Available Technology Economically
Achievable
XI New Source Performance Standards 425
XII Pretreatment Standards 441
XIII Best Conventional Pollutant Control Technology 465
XIV Acknowledgments 467
XV References 469
XVI Glossary
v
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GENERAL DEVELOPMENT DOCUMENT
LIST OF TABLES
Table Title Page
I-l List of Subcategories Considered 7
1-2 Process Wastewater Streams Identified in 8
Nonferrous Metals Manufacturing
I-3 Treatment Options Considered and Selected 16
II-l Promulgated Effluent Limitations and Standards 20
III-l Summary of DCP Respondents by Type of Metal 32
Processed
V-l Distribution of Sampled Plants in the Nonferrous 48
Metals Manufacturing Category by Subcategories
VI-1 List of 129 Priority Pollutants 126
VI—2 Pollutants Selected for Further Consideration 131
by Subcategory
VI-3 Polyneeulear Aromatic Hydrocarbons 143
VII-1 pH Control Effect on Metals Removal 235
VI1-2 Effectiveness of Sodium Hydroxide for 235
Metals Removal
VI1-3 Effectiveness of Lime and Sodium Hydroxide 236
for Metals Removal
VI1-4 Theoretical Solubi1i t ies of Hydroxides and 236
Sulfides of Selected Metals in Pure Water
VI1-5 Sampling Data from Sulfide Precipitation — 237
Sedimentation Systems
VII-6 Sulfide Precipitation — Sedimentation 238
Performance
VI1-7 Ferrite Co-Precipitation Performance 239
VI1-8 Concentration of Total Cyanide 2 3 9"
VI1-9 Multimedia Filter Performance 240
VII-10 Performance of Selected Settling Systems 240
VH-11 Skimming Performance 241
VII-l2 Selected Partition Coefficients 241
vi
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GENERAL DEVELOPMENT DOCUMENT
LIST OF TABLES (Continued)
Table Page
VII-13 Trace Organic Removal by Skimming — 242
API Plus Belt Skimmers
VI1-14 Combined Metals Data Effluent Values 242
VII-15 L&S Performance — Additional Pollutants 243
VII-16 Combined Metals Data Set-Untreated Wastewaters 243
VII-17 Pollutant Content of Untreated Wastewater 244
VII-18 Precipitation-Settling-Filtration (LS&F) 245
Performance -- Plant A
VII-19 Precipitation-Settling-Filtration (LS&F) 246
Performance — Plant A
VII-20 Precipitation-Settling-Filtration (LS&F) 247
Performance -- Plant A
VII-21 Summary of Treatment Effectiveness 248
VII-22 Treatability Rating of Priority Pollutants 249
Utilizing Carbon Adsorption
VII-23 Classes of Organic Compounds Asdorbed 250
on Carbon
VII-24 Activated Carbon Performance (MERCURY) 251
VII-25 Ion Exchange Performance 251
VII-26 Membrane Filtration System Effluent 252
VII-27 Peat Absorption Performance 252
VII-28 Ultrafiltrationn Performance 253
VIII-1 BPT Cost of Compliance for the Nonferrous 327
Metals Manufacturing Category
VIII-2 BAT Cost of Compliance for the Nonferrous 328
Metals Manufacturing Category
VIII-3 PSES Costs of Compliance for the Nonferrous 329
Metals Manufacturing Category
VII1-4 Nonferrous Metals Manufacturing Phase II 330
Category Cost Equations for Recommended
Treatment and Control Technologies
v 1 1
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GENERAL DEVELOPMENT DOCUMENT
LIST OF TABLES (Continued)
Table Title Page
VIII-5 Components of Total Capital Investment 341
VIII-6 Components of Total Annualized Costs 342
VIII-7 Wastewater Sampling Frequency 343
VIII-8 Cost Program Pollutant Parameters 344
VIII-9 Flow Reduction Recycle Ratio and Associated 345
Cost Assumptions
VIII-10 Nonferrous Metals Manufacturing (Phase I) 347
Compliance Costs — Secondary Silver
Subcategory
VIII-11 Nonferrous Metals Manufacturing Waste Generation 348
VIII-12 Nonferrous Metals Manufacturing Energy 349
Consumpt ion
IX-1 Summary of Current Treatment Practices 383
IX-2 BPT Regulated Pollutant Parameters 386
X-l Options Considered for Each of the Nonferrous 415
Metals Manufacturing Subcategories
X-3 Priority Pollutants Effectively Controlled by 419
Technologies Upon Which are Based Other Effluent
Limitations and Guidelines
X-4 Toxic Pollutants Detected but only in Trace 424
Amounts and are neither causing nor likely to
cause Toxic Effects
XI-1 Regulated Pollutant Parameters 436
XII-1 Pollutants Selected for Regulation for 461
Pretreatment Standards by Subcategory
vi i i
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GENERAL DEVELOPMENT DOCUMENT
LIST OF FIGURES
Number Title Page
VII-1 Comparative Solubilities of Metal Hydroxides 254
and Sulfide as a Function of pH
VI1-2 Effluent Zinc Concentration vs. Minimum 255
Effluent pH
VI1-3 Lead Solubility in Three Alkalis 256
VI1-4 Hydroxide Precipitation Sedimentation 257
Effectiveness -- Cadmium
VI1-5 Hydroxide Precipitation Sedimentation 258
Effectiveness — Chromium
VI1-6 Hydroxide Precipitation Sedimentation 259
Effectiveness — Copper
VII-7 Hydroxide Precipitation Sedimentation 260
Effect iveness — Lead
VII-8 Hydroxide Precipitation Sedimentation 261
Effectiveness — Nickel and Alumimum
V11-9 Hydroxide Precipitation Sedimentation 262
Effectiveness — Zinc
VII-10 Hydroxide Precipitation Sedimentation 263
Effectiveness — Iron
VII-11 Hydroxide Precipitation Sedimentation 264
Effectiveness — Manganese
VI1-12 Hydroxide Precipitation Sedimentation 265
Effectiveness — TSS
VI1-13 Hexaualent Chromium Reduction with 266
Sulfur Dioxide
VI1-14 Granular Bed Filtration 267
VI1-15 Pressure Filtration 268
VI1-16 Representative Types of Sedimentation 269
VII-17 Activated Carbon Adsorption Column' 270
VI I-1 8 Centrifugation 271
VI1-19 Treatment of Cyanide Waste by Alkaline 272
Chlorination
IX
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GENERAL DEVELOPMENT DOCUMENT
LIST OF FIGURES (Continued)
Number Title Page
VII-20 Typical Ozone Plant for Waste Treatment 273
VII-21 UV/Ozonation 274
VI1-22 Types of Evaporation Equipment 275
VII-23 Dissolved Air Flotation 276
VII-24 Gravity Thickening 277
VII-25 Ion Exchange with Regeneration 278
VI1-26 Simplified Reverse Osmosis Schematic 279
VII-27 Reverse Osmosis Membrane Configurations 280
VII-28 Sludge Drying Bed 281
VII-29 Simplified Ultrafiltration Flow Schematic 282
VII-30 Vacuum Filtration 283
VII-31 Flow Diagram for Recycling with a 284
Cooling Tower
VIII-1 General Logic Diagram of Computer Cost Model 350
VI11 —2 Logic Diagram of Module Design Procedure 351
VIII-3 Logic Diagram of the Cost Estimation Routing 352
VIII-4 Capital and Annual Costs for — 353
Cooling Tower, Holding Tank
VIII-5 Capital and Annual Costs for — 354
Flow Equalization
VIII-6 Capital and Annual Costs for -- 355
Cyanide Precipitation
VII1-7 Capital and Annual Costsfor — 356
Ammonia Steam Stripping
VIII-8 Capital and Annual Costs for — 357
Oil Water Separation
VIII-9 Capital and Annual Costs for — 358
Chemical Precipitation
x
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GENERAL DEVELOPMENT DOCUMENT
LIST OF FIGURES (Continued)
Number Ti tie Page
VIII-I0 Capital and Annual Costs for — 359
Sulfide Precipitation
VIII-11 Capital and Annueal Costs for — 360
Vacuum Filtration
VIII-12 Capital and Annual Costs for — 361
Holing Tanks, Recycle
VIII-13 Capital and Annual Costs for — 362
Multimedia Filtration
VIII-14 Capital and Annual Costs for — 363
Activated Carbon Adsorption
VIII-15 Costs for Contract Hauling 364
xx
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GENERAL DEVELOPMENT DOCUMENT
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GENERAL DEVELOPMENT DOCUMENT SECT - I
SECTION I
SUMMARY
The United States Environmental Protection Agency (EPA) has
promulgated effluent limitations and standards for the nonferrous
metals manufacturing category pursuant to Sections 301, 304, 306,
307, and 501 of the Clean Water Act. The promulgated regulation
contains effluent limitations for best practicable control
technology currently available (BPT), and best available
technology economically achievable (BAT), as well as pretreatment
standards for new and existing sources (PSNS and PSES), and new
source performance standards (NSPS).
This development document presents the technical summary of EPA's
study of the nonferrous metals manufacturing category. This
volume summarizes the general findings of the study, while the
remaining volumes contain supplements that detail specific
results for each subcategory.
The Agency's economic analysis of the regulation is set forth in
two documents entitled Economic Impact Analysis of Effluent
Limitations, Guidelines and Standards for the Nonferrous Metals
Manufacturing Point Source Category Phase I, and Phase II. These
documents are available from the Office of Analysis and
Evaluation, Economic Analysis Staff, WH-586, U.S. Environmental
Protection Agency, Washington, D.C., 20460.
EXISTING REGULATIONS
Since 1974, implementation of the technolocy-based effluent
limitations and standards has been- guided by a series of
settlement agreements into which EPA entered with several
environmental groups, the latest of which occurred in 1979. NRDG
v. Costle, 12 ERC 1833 (D.D.C. 1979), affirmed and remanded, EPF
v. Costle, 14 ERC 2161 (1980). Under the settlement agreements,
EPA was required to develop BAT limitations and pretreatment and
new source performance standards for 65 classes of pollutants
discharged from specific industrial point source categories. The
list of 65 classes was substantially expanded to a list of 126
specific priority pollutants three of which subsequently have
been removed.
METHODOLOGY
To develop the effluent limitations and standards presented in
this document, the Agency characterized the category by
subdividing it, collecting raw and treated wastewater samples,
and examining water usage and discharge rates, and production
processes. To gather data about the category, EPA developed a
1
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GENERAL DEVELOPMENT DOCUMENT
SECT - I
questionnaire (data collection portfolio - acp) to collect
information regarding plant size, age and production, the
production processes used, the quantity of process wastewater
used and discharged, wastewater treatment in-place, and disposal
practices. The dcp were sent to 540 firms (693 plants) known or
believed to perform nonferrous smelting and refining operations.
These responses were reviewed, and it was determined that there
were 450 plants among the 693 plants queried that were within the
nonferrous metals manufacturing point source category.
As a next step, EPA conducted a sampling and chemical analysis
program to characterize the raw (untreated) and treated process
wastewater. This program was carried out in three stages. In
the first stage, 30 plants were sampled to characterize all the
significant waste streams and production processes in these
industries. In the second stage, 54 plants were sampled, to
expand the data base, and to confirm data acquired during the
first phase of sampling. The third stage consisted of a plant
self-sampling effort in which eight plants submitted data on
specific waste streams for which EPA had not previously acquired
analytical data. These data were used to confirm assumptions
made in developing the limitations. Samples were generally
analyzed for 124 of the 126 priority pollutants and other
pollutants deemed appropriate. Because no analytical standard
was available for TCDD, samples were never analyzed for this
pollutant, although there is no reason to believe that it would
be present in nonferrous metals manufacturing wastewater. Also,
few samples were analyzed for asbestos because there is no reason
to believe that asbestos would be present in nonferrous metals
manufacturing wastewaters. A discussion of the sampling and
analytical methods and procedures is presented in Section V.
EPA then reviewed the rate of production and wastewater
generation reported in the dcp's for each manufacturing
operation, as well as the wastewater characteristics determined
during sampling, as the principal basis for subcategorizing the
industry. The data demonstrated that the industry should be
subcategorized by major metal manufacturing process. A
discussion of the subcategorization scheme is presented in
Section IV. For this rulemaking, the nonferrous metals
manufacturing point source category includes 36
subcategories(Table 1-1, page 7). These subcategories addressed a
total of 63 metals and metal types including both primary and
secondary production.
The nonferrous metals manufacturing point source category is
divided into subcategories based on differences in the quantity
and quality of wastewater generated which are related to
differences in manufacturing processes. This has resulted in the
designation of 31 subcategories for regulation. Five
subcategories were excluded from regulation. Primary boron,
primary cesium and rubidiurr., primary lithium and secondary zinc
were excluded because no plants in these subcategories discharge
wastewater and primary magnesium was excluded because no plants
in this subcategory discharge treatable concent rat ions of
2
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GENERAL DEVELOPMENT DOCUMENT SECT - I
pollutants. Each regulated subcategory is further subdivided
into major sources of wastewater for specific limitation. The
process wastewater streams identified in the nonferrous metals
manufacturing category are listed by subcategory in Table 1-2
(page 8).
There are more than 450 plants identified in the nonferrous
metals manufacturing point source category discharging an
estimated 136.2 billion liters per year of process wastewater.
Untreated, this process wastewater contains approximately
3,650,000 kilograms of toxic pollutants.
The pollutants generated within the nonferrous metals
manufacturing subcategories are diverse in nature due to varying
raw materials and production processes. Thus, the Agency
examined various end-of-pipe and pretreatment technologies to
treat the pollutants present in the identified process
wastewaters. The Pollutants selected for consideration for each
subcategory are presented in Section VI. The treatment
technologies considered for each subcategory are shown in Table
1-3 (Page 16).
Engineering costs were prepared for each of the treatment options
considered for each subcategory. These costs were then used by
the Agency to estimate the impact of implementation of the
various options by the industry For each subcategory for each
control and treatment option, the number of potential closures,
number of employees affected, and impact on price were estimated.
These results are reported in the economic impact analysis
document.
The Agency then reviewed each of the treatment options for each
subcategory to determine the estimated mass of pollutant removed
by the application of each treatment technology. The pollutant
removal after the application of the treatment technology is
referred to as the benefit. The methodology used to calculate
the pollutant removal estimates is presented in Section X.
TECHNOLOGY BASIS FOR LIMITATIONS AND STANDARDS
In general, the BPT level represents the average of the best
existing performances of plants of various ages, sizes, processes
or other common characteristics. Where existing performance is
uniformly inadequate, BPT may be transferred from a different
subcategory or category.
In balancing costs in relation to effluent reduction benefits,
EPA considers the volume and nature of existing discharges, the
volume and nature of discharges expected after application of
BPT, the general environmental effects of the pollutants, and
cost and economic impacts of the required pollution control
level.
After examining the various treatment technologies, the Agency
has identified BPT to represent the average of the best existing
3
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GENERAL DEVELOPMENT DOCUMENT SECT - I
plants. Metals removal based on chemical precipitation and
sedimentation technology is the basis for the BPT limitations for
25 subcategories. Two subcategories, primary copper smelting and
secondary copper, are already subject to zero discharge of all
process wastewater pollutants. The Agency did not promulgate BPT
requirements for three subcategories, secondary indium, secondary
mercury, and secondary nickel because these subcategories contain
no existing direct dischargers. EPA promulgated only minor
technical amendments to the existing BPT limitations for the
bauxite refining subcategory. Steam stripping is selected as the
basis for ammonia limitations in nine subcategories. Air
stripping is selected as the technology basis for ammonia
limitations in one subcategory, namely, secondary molybdenum and
vanadium. Oil skimming is selected as the basis for oil and
grease limitations in three subcategories: primary precious
metals and mercury, primary and secondary titanium, and secondary
tungsten and cobalt. Cyanide precipitation is selected as the
technology basis for cyanide limitations for the primary
beryllium, secondary precious metals, secondary tin, and primary
2irconium and hafnium subcategories. Ion exchange is selected as
the technology basis for gold, platinum and palladium limitations
in the primary precious metals and mercury, and secondary
precious metals subcategories. Iron co-precipitation was
selected as the technology basis for molybdenum limitations in
the primary molybdenum and rhenium, metallurgical acid plants,
and secondary molybdenum and vanadium subcategories. To meet the
promulgated BPT effluent limitations based on these technologies,
it is estimated that the nonferrous metals manufacturing point
source category will incur a capital cost of $7.28 million (1982
dollars) and an annual cost of $9.3 million (1982 dollars).
The BAT technology level represents the best economically
achievable performance of plants of various ages, sizes,
processes or other shared characteristics. BAT may be
transferred from a different subcategory or category. BAT may
include feasible process changes or internal controls, even when
not common industry practice.
In developing BAT, EPA has given substantial weight to the
reasonableness of costs. The Agency considered the volume and
nature of discharges, the volume and nature of discharges
expected after application of BAT, the general environmental
effects of the pollutants, and the costs and economic impacts of
the required pollution control levels.
Despite this consideration of costs, the primary determinant of
BAT is effluent reduction capability. For BAT, the Agency has
built upon the BPT technology basis by adding in-process control
technologies which include recycle of process water from air
pollution control and metal contact cooling waste streams, as
well as other flow reductions, where achievable. Filtration is
added as an effluent polishing step to the end-of-pipe treatment
scheme. Implementation of this technology increases the
reliability of the treatment system by making it less susceptible
to operator error and to surges in raw wastewater flow and
4
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GENERAL DEVELOPMENT DOCUMENT SECT - I
concentrations. Sulfide precipitation technology is added for
primary copper electrolytic refining, primary lead, primary zinc,
and metallurgical acid plants facilities.
To meet the BAT effluent limitations based on this technology,
the nonferrous metals manufacturing point source category is
estimated to incur a capital cost of $28.4 million (1982 dollars)
and an annual cost of $22.7 million (1982 dollars).
New Source Performance Standards (NSPS) are based on the best
demonstrated available technology (BDT), including process
changes, in-plant controls, and end-of-pipe treatment
technologies which reduce pollution to the maximum extent
feasible. NSPS are equivalent to BAT for 25 subcategories. For
three subcategories which currently have no direct dischargers,
BAT was not promulgated. For one of these, secondary mercury,
metals removal based on chemical precipitation, sedimentation,
and filtration (the selected BAT for most of the 25 subcategories
with direct dischargers) is the basis for NSPS limitations. For
the secondary indium and secondary nickel subcategories chemical
precipitation and sedimentation is selected as the basis for
metals removal. In selecting NSPS, EPA recognizes that new
plants have the opportunity to implement the best and most
efficient manufacturing processes and treatment technology. As
such, new source performance standards for the primary and
secondary titanium subcategory are equivalent to BAT plus zero
discharge for chip crushing, sponge crushing and screening, scrap
milling, and chlorine liquefaction air pollution control. New
source performance standards for the primary aluminum subcategory
are based on dry alumi na air pollution scrubbing systems or 100
percent recycle. Implementation of this technology at primary
aluminum plants eliminates the discharge of toxic organics due to
air emission scrubbing associated with anode paste plants, anode
bake plants, potlines and potrooms. New source performance
standards for the primary lead subcategory require zero discharge
of all process wastewaters except for employee hand wash,
employee respirator wash, and laundering of uniforms. Zero
discharge for all other process wastewater is achievable through
dry slag conditioning instead of using high pressure water jets
to granulate smelter slag.
PSES (pretreatment standards for existing sources) are designed
to prevent the discharge of pollutants which pass through,
interfere with, or are otherwise incompatible with the operations
of POTW. For PSES, the Agency selected the same technology as
BAT, which is BPT end-of-pipe treatment in conjunction with in-
process flow reduction control techniques followed by effluent
polishing filtration, for the secondary aluminum, secondary
copper, primary lead, primary zinc, metallurgical acid plants,
primary tungsten, primary columbium-tantalum, secondary silver,
secondary lead, secondary precious metals, primary rare earth
metals, secondary tin, primary and secondary titanium, and
secondary tungsten and cobalt subcategories. Chemical
precipitation and sedimentation is selected as the technology
basis for PSES limitations for the primary and secondary
5
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GENERAL DEVELOPMENT DOCUMENT SECT - I
germanium and gallium, secondary indium, and secondary nickel
subcategories. The Agency did not promulgate PSES for the
remaining 15 subcategories because there are no existing indirect
dischargers in these subcategories. To meet the pretreatment
standards for existing sources, the nonferrous metals
manufacturing point source category is estimated to incur a
capital cost of $12.2 million (1982 dollars) and an annual cost
of $7.3 million (1982 dollars).
Pretreatment Standards for New Sources (PSNS) are designed to
prevent the discharge of pollutants which pass through, interfere
with, or are otherwise incompatible with the operation of the
POTW. New indirect dischargers, like new direct dischargers,
have the opportunity to incorporate the best available
demonstrated technologies including process changes, in-plant
controls, and end-of-pipe treatment technologies, and to use
plant site selection to ensure adequate treatment system
installation.
This regulation establishes mass-based PSNS for all 31 regulated
subcategories. For PSNS, the Agency selected end-of-pipe
treatment and in-process flow reduction control techniques
equivalent to NSPS for 28 of the subcategories and equivalent to
PSES for the remaining three subcategories.
Non-Water Quality Environmental Impacts
Eliminating or reducing one Eorm of pollution may cause other
environmental problems. Sections 304(b) and 306 of the Act
require EPA to consider the non-water quality environmental
impacts (including energy requirements) of certain regulations.
In compliance with these provisions, EPA considered the effect of
this regulation on air pollution, solid waste generation, water
scarcity, and energy consumption.
This regulation was reviewed by EPA personnel responsible for
non-water quality programs. While it is difficult to balance
pollution problems against each other and against energy use, we
believe that this regulation will best serve often competing
national goals.
Wastewater treatment sludges from this category are expected to
be non-hazardous by the E.P.Toxicity test under RCRA when
generated using the model technology. Treatment of similar
wastewaters from other categories using this technology has
resulted in non-hazardous sludges. Costs for disposal of non-
hazardous wastes are included in the annual costs. The only
sludges expected to be hazardous under RCRA, generated as a
result of wastewater treatment, are those from sulfide or cyanide
precipitation steps. The Agency has included costs for disposal
of those hazardous sludges in its estimates of compliance costs,
To achieve the BPT and BAT effluent limitations, a typical direct
discharger will increase total energy consumption by less than
one percent of the energy consumed for production purposes.
6
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GENERAL DEVELOPMENT DOCUMENT SECT - I
TABLE 1-1
LIST OP SUBCATEGORIES CONSIDERED
1.
Bauxite Refining
2.
Primary Aluminum Smelting
3.
Secondary Aluminum Smelting
4.
Primary Copper Smelting
5.
Primary Electrolytic Copper Refining
6.
Secondary Copper
7.
Primary Lead
8.
Primary Zinc
9.
Metallurgical Acid Plants
10.
Primary Tungsten
11.
Primary Columbium-Tantalum
12.
Secondary Silver
13.
Secondary Lead
14.
Primary Antimony
15.
Primary Beryllium
16.
Primary Boron
17.
Primary Cesium and Rubidium
18.
Primary and Secondary Germanium and Gallium
19.
Secondary Indium
20.
Primary Lithium
21.
Primary Magnesium
22.
Secondary Mercury
23.
Primary Molybdenum and Rhenium
24.
Secondary Molybdenum and Vanadium
25.
Primary Nickel and Cobalt
26.
Secondary Nickel
27.
Primary Precious Metals and Mercury
28.
Secondary Precious Metals
29.
Primary Rare Earth Metals
30.
Secondary Tantalum
31.
Secondary Tin
32.
Primary and Secondary Titanium
33.
Secondary Tungsten and Cobalt
34.
Secondary Uranium
35.
Secondary Zinc
36.
Primary Zirconium and Hafnium
7
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GENERAL DEVELOPMENT DOCUMENT SECT - I
TABLE 1-2
PROCESS WASTEWATER STREAMS IDENTIFIED IN
NONFERROUS METALS MANUFACTURING
Bauxite Refining
Mud Impoundment Effluent (Net Precipitation Discharge)
Primary Aluminum Smelting
Anode and Cathode Paste Plant Wet Air Pollution Control
Anode Bake Plant Wet Air Pollution Control
Anode Contact Cooling and Briquette Quenching
Cathode Reprocessing
Potline Wet Air Pollution Control
Potroom Wet Air Pollution Control
Direct Chill Casting
Continuous Rod Casting
Stationary Casting or Shot Casting
Degassing Wet Air Pollution Control
Pot Repair and Soaking
Spent Potliner Leachate
Secondary Aluminum Smelting
Scrap Drying Wet Air Pollution Control
Scrap Screening and Milling
Dross Washing
Demagging Wet Air Pollution Control
Delacquering Wet Air Pollution Control
Direct Chill Casting
Ingot Conveyer Casting
Stationary Casting
Shot Casting
Primary Copper Smelting
Slag Granulation
Casting Contact Cooling
Casting Wet Air Pollution Control
Primary Electrolytic Copper Refining
Anode and Cathode Rinsing
Spent Electrolyte
Casting Contact Cooling
Casting Wet Air Pollution Control
By-Product Recovery
8
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GENERAL DEVELOPMENT DOCUMENT SECT - I
TABLE 1-2 (Continued)
PROCESS WASTEWATER STREAMS IDENTIFIED IN
NONFERROOS METALS MANUFACTURING
Secondary Copper
Slag Milling and Classification
Smelting Wet Air Pollution Control
Casting Contact Cooling
Spent Electrolyte
Slag Granulation
Primary Lead
Sinter Plant Materials Handling Wet Air Pollution Control
Blast Furnace Slag Granulation
Blast Furnace Wet Air Pollution Control
Zinc Fuming Wet Air Pollution Control
Dross Reverberatory Slag Granulation
Dross Reverberatory Furnace Wet Air Pollution Control
Hard Lead Refining Slag Granulation
Hard Lead Refining Wet Air Pollution Control
Facility Washdown
Employee Hand Wash
Employee Respirator Wash
Laundering of Uniforms
Primary Zinc
Zinc Reduction Furnace Wet Air Pollution Control
Preleach of Zinc Concentrates
Leaching Wet Air Pollution Control
Electrolyte Bleed Wastewater
Cathode and Anode Washing
Casting Wet Air Pollution Control
Casting Contact Cooling
Cadmium Plant Wastewater
Metallurgical Acid Plants
Acid Plant Blowdown
9
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GENERAL DEVELOPMENT DOCUMENT SECT -
I
TABLE 1-2 (Continued)
PROCESS WASTEWATER STREAMS IDENTIFIED IN
NONFERROUS METALS MANUFACTURING
Primary Tungsten
Tungstic Acid Rinse
Acid Leach Wet Air Pollution Control
Alkali Leach Wash
Ion-Exchange Raffinate
Calcium Tungstate Precipitate Wash
Crystallization and Drying of Ammonium Paratungstate
Ammonium Paratungstate Conversion to Oxide Wet Air
Pollution Control
Ammonium Paratungstate Conversion to Oxides Water of
Formation
Reduction to Tungsten Wet Air Pollution Control
Reduction to Tungsten Water of Formation
Tungsten Powder Acid Leach and Wash
Molybdenum Sulfide Precipitation Wet Air Pollution Control
Alkali Leach Condensate
Primary Columbium-Tantalum
Concentrate Digestion Wet Air Pollution Control
Solvent Extraction Raffinate
Solvent Extraction Wet Air Pollution Control
Precipitation and Filtration of Metal Salts
Precipitation and Filtration Wet Air Pollution Control
Tantalum Salt Drying
Reduction of Tantalum Salt to Metal
Reduction of Tantalum Salt to Metal Wet Air Pollution
Control
Oxides Calcining Wet Air Pollution Control
Tantalum Powder Wash
Consolidation and Casting Contact Cooling
Secondary Silver
Film Stripping
Film Stripping Wet Air Pollution Control
Precipitation and Filtration of Film Stripping Solutions Wet
Air Pollution Control
Precipitation and Filtration of Film Stripping Solutions
Precipitation and Filtration of Photographic Solutions
Precipitation and Filtration of Photographic Solutions Wet
Air Pollution Control
Electrolytic Refining
Furnace Wet Air Pollution Control
Leaching
Leaching Wet Air Pollution Control
Precipitation of Nonphotographic Solutions Wet Air Pollution
Control
Precipitation and Filtration of Nonphotographic Solutions
Floor and Equipment Washdown
10
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GENERAL DEVELOPMENT DOCUMENT SECT - I
TABLE 1-2 (Continued)
PROCESS WASTEWATER STREAMS IDENTIFIED IN
NONFERROUS METALS MANUFACTURING
Secondary Lead
Battery Cracking
Blast, Reverberatory, and Rotary Furnace Wet Air Pollution
Control
Kettle Wet Air Pollution Control
Casting Contact Cooling
Lead Paste Desulfurization
Truck Wash
Facility Washdown
Battery Case Classification
Employee Hand Wash
Employee Respirator Wash
Laundering of Uniforms
Primary Antimony
Sodium Antimonate Autoclave Wastewater
Fouled Anolyte
Cathode Antimony Washwater
Primary Beryllium
Solvent Extraction Raffinate from
Solvent Extraction Raffinate from
Beryllium Carbonate Filtrate
Beryllium Hydroxide Filtrate
Beryllium Oxide Calcining Furnace
Beryllium Hydroxide Supernatant
Process Water
Fluoride Furnace Scrubber
Chip Treatment Wastewater
Beryllium Pebble Plant Area-Vent Wet Air Pollution Control
Beryl Ore Gangue Dewatering
Bertrandite Ore Gangue Dewatering
Beryl Ore Processing
AIS Area Wastewater
Bertrandite Ore Leaching Scrubber
Bertrandite Ore Counter Current
Decantation Scrubber
Primary and Secondary Germanium and Gallium
Still Liquor
Chlorinator Wet Air Pollution Control
Germanium Hydrolysis Filtrate
Acid Wash and Rinse Water
Gallium Hydrolysis Filtrate
Solvent Extraction Raffinate
Bertrandite Ore
Beryl Ore
Wet Air Pollution Control
11
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GENERAL DEVELOPMENT DOCUMENT SECT - I
TABLE 1-2 (Continued)
PROCESS WASTEWATER STREAMS IDENTIFIED IN
NONFERROUS METALS MANUFACTURING
Secondary Indium
Displacement Tank Supernatant
Spent Electrolyte
Secondary Mercury
Spent Battery Electrolyte
Acid Wash and Rinse Water
Furnace Wet Air Pollution Control
Primary Molybdenum and Rhenium
. aLm m ,i.i — ..
Molybdenum Sulfide Leaching
Roaster S02 Scrubber
Molybdic Oxide Leachate
Hydrogen Reduction Furnace Scrubber
Depleted Rhenium Scrubbing Solution
Secondary Molybdenum and Vanadium
Leach Tailings
Molybdenum Filtrate Solvent Extraction Raffinate
Vanadium Decomposition Wet Air Pollution Control
Molybdenum Drying Wet Air Pollution Control
Pure Grade Molybdenum
Primary Nickel and Cobalt
Raw Material Dust Control
Nickel Wash Water
Nickel Reduction Decant
Cobalt Reduction Decant
Secondary Nickel
Slag Reclaim Tailings
Acid Reclaim Leaching Filtrate
Acid Reclaim Leaching Belt Filter Backwash
12
-------
GENERAL DEVELOPMENT DOCUMENT SECT - I
TABLE 1-2 (Continued)
PROCESS WASTEWATER STREAMS IDENTIFIED IN
NONFERROUS METALS MANUFACTURING
Primary Precious Metals and Mercury
Smelter Wet Air Pollution Control
Silver Chloride Reduction Spent Solution
Electrolytic Cells Wet Air Pollution Control
Electrolyte Preparation Wet Air Pollution Control
Calciner Wet Air Pollution Control
Calciner Quench Water
Calciner Stack Gas Contact Cooling Water
Mercury Calcining Condensate
Mercury Cleaning Bath Water
Secondary Precious Metals
Furnace Wet Air Pollution Control
Raw Material Granulation
Spent Plating Solutions
Spent Cyanide Stripping Solutions
Retinery Wet Air Pollution Control
Gold Solvent Extraction Raffinate and Wash Water
Gold Spent Electrolyte
Gold Precipitation and Filtration
Platinum Precipitation and Filtration Palladium Precipitation and
Filtration Other Platinum Group Metals Precipitation and
Filtration Spent Solution from PGC Salt Production Equipment and
Floor Wash
Preliminary Treatment
Primary Rare Earth Metals
Dryer Vent Water Quench and Scrubber
Dryer Vent Caustic Wet Air Pollution Control
Electrolytic Cell Water Quench and Scrubber
Electrolytic Cell Caustic Wet Air Pollution Control
Sodium Hypochlorite Filter Backwash
Secondary Tantalum
Tantalum Alloy Leach and Rinse
Capacitor Leach and Rinse
Tantalum Sludge Leach and Rinse
Tantalum Powder Acid Wash and Rinse
Leaching Wet Air Pollution Control
13
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GENERAL DEVELOPMENT DOCUMENT SECT - I
TABLE 1-2 (Continued)
PROCESS WASTEWATER STREAMS IDENTIFIED IN
NONFERROUS METALS MANUFACTURING
Secondary Tin
Tin Smelter SO2 Scrubber
Dealuminizing Rinse
Tin Hydroxide Wash
Tin Mud Acid Neutralization Filtrate
Spent Electrowinning Solution from New Scrap
Spent Electrowinning Solution from Municipal Solid Waste
Tin Hydroxide Supernatant from Scrap
Tin Hydroxide Supernatant from Spent Flating Solutions and
Sludges
Tin Hydroxide Filtrate
Primary and Secondary Titanium
Chlorination Off-Gas Wet Air Pollution Control
Chlorination Area-Vent Wet Air Pollution Control
TiCl4 Handling Wet Air Pollution Control
Reduction Area Wet Air Pollution Control
Melt Cell Wet Air Pollution Control
Chlorine Liquefaction Wet Air Pollution Control
Sodium Reduction Container Reconditioning Wash Water
Chip Crushing Wet Air Pollution Control
Acid Leachate and Rinse Water
Sponge Crushing and Screening Wet Air Pollution Control
Acid Pickle and Wash Water
Scrap Milling Wet Air Pollution Control
Scrap Detergent Wash Water
Casting Crucible Wash Water
Casting Contact Cooling Water
Secondary Tungsten and Cobalt
Tungsten Detergent Wash and Rinse
Tungsten Leaching Acid
Tungsten Post-Leaching Wash and Rinse
Synthetic Scheelite Filtrate
Tungsten Carbide Leaching Wet Air Pollution Control
Tungsten Carbide Wash Water
Cobalt Sludge Leaching Wet Air Pollution Control
Crystallization Decant
Acid Wash Decant
Cobalt Hydroxide Filtrate
Cobalt Hydroxide Filter Cake Wash
14
-------
GENERAL DEVELOPMENT DOCUMENT SECT - I
TABLE 1-2 (Continued)
PROCESS WASTEWATER STREAMS IDENTIFIED IN
NONFERROUS METALS MANUFACTURING
Secondary Uranium
Refinery Sump Filtrate
Slag leach Reslurry
Solvent Extraction Raffinate Filtrate
Digestion Wet Air Pollution Control
Evaporation and Denitration Wet Air Pollution Control
Hydrofluorination Alkaline Scrubber
Hydrofluorination Water Scrubber
Magnesium Reduction and Casting Floor Wash Water
Laundry Wastewater
Primary Zirconium and Hafnium
Sand Drying Wet Air Pollution Control
Sand Chlorination Off-Gas Wet Air Pollution Control
Sand Chlorination Area-Vent Wet Air Pollution Control
SiCl4 Purification Wet Air Pollution Control
Feed Make-up Wet Air Pollution Control
Iron Extraction (MIBK) Steam Stripper Bottoms
Zirconium Filtrate
Hafnium Filtrate
Calcining Caustic Wet Air Pollution Control
Pure Chlorination Wet Air Pollution Control
Reduction Area-Vent Wet Air Pollution Control
Magnesium Recovery Off Gas Wet Air Pollution Control
Magnesium Recovery Area-Vent Wet Air Pollution Control
Z irconium Chip Crushing Wet Ai r Pollution Cont rol
Acid Leachate from Zirconium Metal Production
Acid Leachate from Zirconium Alloy Production
Leaching Rinse Water from Zirconium Metal Production
Leaching Rinse Water from Zirconium Alloy Production
15
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GENERAL DEVELOPMENT DOCUMENT SECT - I
TABLE 1-3
TREATMENT OPTIONS CONSIDERED AND SELECTED
Treatment Technology Options
Considered Selected
Subcategory A B C E BPT BAT NSPS
Bauxite Refining
X
ZD
ZD
ZD
Primary Aluminum Smelting
X
X
X
-
C
c
Secondary Aluminum Smelting
X
X
X
-
C
c
Primary Copper Smelting
X
X
_
ZD
ZD
Primary Copper Electrolytic
X
X
X
-
C
C
Refining
Secondary Copper
X
X
—
ZD
ZD
Primary Lead
X
X
X
A
C
C
Primary Zinc
X
X
X
-
c
c
Metallurgical Acid Plants
X
X
X
A
c
C
Primary Tungsten
X
X
X
X
A
c
c
Primary Columbium-Tantalum
X
X
X
X
A
c
c
Secondary Silver
X
X
X
X
A
c
c
Secondary Lead
X
X
X
A
c
c
Primary Antimony
X
X
A
c
c
Primary Beryllium
X
X
A
c
c
Primary Boron
X
X
—
_
—
Primary Cesium and Rubidium
X
X
-
-
-
Primary and Secondary
X
X
A
A
A
Germanium and Gallium
Secondary Indium
X
X
_
-
A
Secondary Mercury
X
X
-
-
c
Primary Molybdenum and
X
X
X
A
c
C
Rhenium
Secondary Molybdenum and
X
X
A
c
c
Vanadium
Primary Nickel and Cobalt
X
X
A
c
c
Secondary Nickel
X
X
—
_
A
Primary Precious Metals
X
X
X
A
c
c
and Mercury
Secondary Precious Metals
X
X
X
A
c
c
Primary Rare Earth Metals
X
X
X
X
-
-
c
16
-------
GENERAL DEVELOPMENT DOCUMENT SECT - I
TABLE 1-3 (Continued)
TREATMENT OPTIONS CONSIDERED AND SELECTED
Treatment Technology Options
Considered Selected
Subcategory A B C E BPT BAT NSPS
Secondary Tantalum
X
X
A
C
C
Secondary Tin
X
X
A
C
C
Primary and Secondary Titanium
X X
X
A
C
C
Secondary Tungsten and
X X
X
A
C
C
Cobalt
Secondary Uranium
X
X
A
C
C
Primary Zirconium and
X
X
A
C
C
Hafnium
Notes: Option A - Chemical precipitation and sedimentation and
sulfide precipitation, iron co-precipitation, ion
exchange, cyanide precipitation, ammonia steam or air
stripping, activated carbon adsorption or oil skimming
where appropriate.
Option B - Option A preceded by flow reduction by
recycling variable quantities of process wastewater.
Option C - Option B plus filtration.
Option E - Option C plus activated carbon adsorption.
ZD - No discharge allowance for pollutants in process
wastewater discharged.
17
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GENERAL DEVELOPMENT DOCUMENT
SECT - I
THIS PAGE INTENTIONALLY LEFT BLANK
18
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GENERAL DEVELOPMENT DOCUMENT SECT - II
SECTION II
CONCLUSIONS
The nonferrous metals manufacturing point source category has
been divided into thirty six subcategories, thirty one of which
are regulated by this regulation. The Agency concluded that five
of the subcategories should not be regulated at this time and
that the remaining thirty one should be subject to effluent
limitations and standards published in the Federal Register. For
some of the subcategories, limitations or standards were not
developed for existing sources because there were either no
direct discharging or no indirect discharging sources. Table II-l
(Page 20) lists all of the regulated subcategories and the
limitations and standards promulgated within each subcategory.
BCT limitations are not promulgated for any subcategory.
Section II of the development document supplement for each
specific subcategory contains a tabulation of the specific
numerical limitations and standards for that subcategory.
19
Preceding page blank
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GENERAL DEVELOPMENT DOCUMENT SECT - II
TABLE II-l
PROMULGATED EFFLUENT LIMITATIONS AND STANDARDS
Subcategory BPT BAT NSPS PSES PSNS
Bauxite Refining
X
X
X
Primary Aluminum Smelting
X
X
X
X
X
Secondary Aluminum Smelting
X
X
X
X
X
Primary Copper Smelting
X
X
X
X
X
Primary Electrolytic
X
X
X
X
Copper Refining
Secondary Copper
X
X
X
X
X
Primary Lead
X
X
X
X
X
Primary Zinc
X
X
X
X
X
Primary Tungsten
X
X
X
X
X
Primary Columbium & Tantalum
X
X
X
X
X
Secondary Silver
X
X
X
X
X
Secondary Lead
X
X
X
X
X
Primary Antimony
X
X
X
X
X
Primary Beryllium
X
X
X
X
Primary and Secondary
X
X
X
X
Germanium and Gallium
Secondary Indium
X
X
X
Secondary Mercury
X
X
Primary Molybdenum and Rhenium
X
X
X
X
Metallurgical Acid Plants
X
X
X
X
X
Secondary Molybdenum and
X
X
X
X
Vanadium
Primary Nickel and Cobalt
X
X
X
X
Secondary Nickel
X
X
X
Primary Precious Metals
X
X
X
X
Mercury
Secondary Precious Metals
X
X
X
X
X
Primary Rare Earth Metals
X
X
X
Secondary Tantalum
X
X
X
X
Secondary Tin
X
X
X
X
X
Primary and Secondary
X
X
X
X
X
Titanium
Secondary Tungsten and Cobalt
X
X
X
X
X
Secondary Uranium
X
X
X
X
Primary Zirconium and Hafnium
X
X
X
X
20
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GENERAL DEVELOPMENT DOCUMENT SECT - III
SECTION III
INTRODUCTION
PURPOSE AND AUTHORITY
The Federal Water Pollution Control Act Amendments of 1972
established a comprehensive program to "restore and maintain the
chemical, physical, and biological integrity of the Nation's
waters," Section 101(a). By July 1, 1977, existing industrial
dischargers were required to achieve "effluent limitations
requiring the application of the best practicable control
technology currently available" (BPT), Section 301(b)(1)(A). By
July 1, 1984, these dischargers were required to achieve
"effluent limitations requiring the application of the best
available technology economically achievable — which will result
in reasonable further progress toward the national goal of
eliminating the discharge of all pollutants" (BAT), Sect:on
301(b)(2)(A). New industrial direct dischargers were required to
comply with Section 306 new source performance standards (NSPS),
based on best available demonstrated technology; and new and
existing dischargers to publicly owned treatment works (POTW)
were subject to pretreatment standards under Sections 307(b) and
(c) of the Act, The requirements for direct dischargers were to
be incorporated into National Pollutant Discharge Elimination
System (NPDES) permits issued under Section 402 of the Act.
Pretreatment standards were made enforceable directly against
dischargers to POTW (indirect dischargers).
Although Section 402(a)(1) of the 1972 Act authorized the setting
of requirements for direct dischargers on a case-by-case basis,
Congress intended that, for the most part, control requirements
would be based on regulations promulgated by the Administrator of
EPA, Section 304(b) of the Act required the Administrator to
promulgate regulations providing guidelines for effluent limita-
tions setting forth the degree of effluent reduction attainable
through the application of BPT and BAT. Moreover, Sections
304(c) and 306 of the Act required promulgation of regulations
for NSPS, and Sections 304(f), 307(b), and 307(c) required
promulgation of regulations for pretreatment standards. In
addition to these regulations for designated industry categories,
Section 307(a) of the Act required the Administrator to
promulgate effluent standards applicable to all dischargers of
toxic pollutants. Finally, Section 501(a) of the Act authorized
the Administrator to prescribe any additional regulations
"necessary to carry out his functions" under the Act.
EPA was unable to promulgate many of these regulations by the
dates contained in the Act. In 1976, EPA was sued by several
environmental groups, and in settlement of this lawsuit, EPA and
the plaintiffs executed a "Settlement Agreement" which was
approved by the District Court. This Agreement required EPA to
develop a program and adhere to a schedule for promulgating, for
21
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GENERAL DEVELOPMENT DOCUMENT SECT - III
21 major industries, BAT effluent limitations guidelines,
pretreatment standards, and new source performance standards for
65 "priority" pollutants and classes of pollutants. See Natural
Resources Defense Council, Inc..v. Train, 8 ERC 2120 (D.D.C.
1976), modified, 12 ERC 1833 (D.D.C. 1979), modified by
additional orders of August 25, 1982, October 26, 1982, August 2,
1983 and January 6, 1984.
On December 27, 1977, the President signed into law the Federal
Water Pollution Control Act (P.L. 95-217) , commonly referred to
as the Clean Water Act of 1977. Although this law makes
several important changes in the federal water pollution
control program, its most significant feature is it
incorporates into the Act several of the basic elements of the
Settlement Agreement program for toxic pollutant control.
Sections 301(b)(2)(A) and 301(b)(2)(C) of the Act now require
the achievement of effluent limitations requiring BAT for "toxic"
pollutants, including the 65 "pollutants and classes of
pollutants which Congress declared "toxic" under Section 307(a)
of the Act. Likewise, EPA's programs for new source performance
standards and pretreatment standards are now aimed principally at
toxic pollutant controls. Moreover, to strengthen the toxics
control program, Section 304(e) of the Act authorizes the
Administrator to prescribe "best management practices" (BMP) to
prevent the release of toxic and hazardous pollutants from plant
site runoff, spillage or leaks, sludge or waste disposal, and
drainage from raw material storage associated with, or anci1lary
to, the manufacturing or treatment process.
The 1977 Amendments added Section 301(b)(2)(E) to the Act,
establishing "best conventional pollutant control technology"
(BCT) for discharges of conventional pollutants from existing
industrial point sources. Conventional pollutants are those
mentioned specifically in Section 304(a)(4) (biochemical
oxygen demanding pollutants (BOD ) total suspended solids
(TSS) fecal coliform, and pH), and any additional pollutants
defined by the Administrator as "conventional." (To date, the
Agency has added one such pollutant, oil and grease, 44 FR 44501,
July 30, 1979.) before establishing them as BCT. In no case
may BCT be less stringent than BPT.
BCT is not an additional limitation but replaces BAT for the
control of conventional pollutants. In addition to other factors
specified in Section 304(b)(4)(B), the Act requires that BCT
limitations be assessed in light of a two-part "cost-
reasonableness" test, American Paper Institute v. EPA, 660 F.2d
954 (4th Cir. 1981). The first test compares the cost for
private industry to reduce its conventional pollutants with the
costs to publicly owned treatment works for similar levels of
reduction in their discharge of these pollutants. The second
test examines the cost-effectiveness of additional industrial
treatment beyond BPT. EPA must find that limitations are
"reasonable" under both tests.
22
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GENERAL DEVELOPMENT DOCUMENT SECT - III
EPA published its methodology for carrying out the BCT analysis
on August 29, 1979 (44 FR 50372). In the case mentioned above,
the Court of Appeals ordered EPA to correct data errors underly-
ing EPA's calculation of the first test, and to apply the second
cost test, (EPA had argued that a second cost test was not
required.)
A revised methodology for the general development of BCT limita-
tions was proposed on October 29, 1982 (47 FR 49176), but had not
been promulgated as a final rule when this regulation was
promulgated. We accordingly have not proposed BCT limits for
plants in the nonferrous metals manufacturing category. We will
await establishing nationally applicable BCT limits for this
industry until promulgation of the final methodology for BCT.
For nonconvent ional pollutants, Sections 301(b)(2)(A) and
(b)(2)(F) require achievement of BAT effluent limitations within
three years after their establishment or July 1, 1984, whichever
is later, but not later than July 1, 1987.
The purpose of these promulgated regulations is to provide efflu-
ent limitations guidelines for BPT and BAT, and to establish
NSPS, pretreatment standards for existing sources (PSES), and
pretreatment standards for new sources (PSNS), under Sections
301, 304, 306, 307, and 501 of the Clean Water Act.
PRIOR EPA REGULATIONS
EPA previously promulgated effluent limitations and pretreatment
standards for certain nonferrous metals manufacturing
subcategories. The nonferrous metals manufacturing regulations
existing prior to the present rulemaking effort (Phase I and
Phase II) and the technological basis for them are briefly
discussed below.
Bauxite Refining Subcategory. EPA promulgated BPT, BAT, NSPS,
and PSNS in this subcategory (39 FR 12822, March 26, 1974). BPT,
BAT, NSPS and PSNS were based on zero discharge of process
wastewater, but allow for a monthly net precipitation discharge
from the red mud impoundment.
Primary Aluminum Subcategory. EPA promulgated BPT, BAT, NSPS,
and PSNS in this subcategory (39 FR 12822, March 26, 1974). BPT
was based on lime precipitation and sedimentation technology.
BAT was based on this technology and flow reduction; NSPS and
PSNS were based on BPT plus additional flow reduction.
Secondary Aluminum Subcategory. Existing regulations in this
subcategory cover BPT, BAT, NSPS, PSES and PSNS (39 FR 12822
(March 26, 1974) and 41 FR 54854 (December 15, 1976)
(establishing pretreatment standards)). BPT was based on lime
precipitation and sedimentation with pH adjustment to control
ammonia. BAT required no discharge of wastewater pollutants,
PSES was based on oil skimming, pH adjustment and ammonia air
stripping, while NSPS and PSNS were based on lime precipitation
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GENERAL DEVELOPMENT DOCUMENT SECT - III
and sedimentation and flow reduction, (Promulgated NSPS and PSNS
were less stringent than BAT and PSES because the processes
believed to be necessary to achieve zero discharge were not yet
demonstrated in 1974 or 1976, but it was believed that they would
be demonstrated at the time of the BAT and PSES compliance
dates.)
Primary Copper Smelting. The existing regulation covered BPT and
BAT. The amended BPT required no discharge of process wastewater
pollutants subject to an exception for unlimited discharge of the
volume of water falling within impoundments in excess of the 10-
year, 24-hour storm (known as a catastrophic precipitation event)
when a storm of at least that magnitude occurred. See 45 FR
44926 (July 2, 1980). Existing BAT, promulgated earlier (40 FR
8523 (February 27, 1975)), was less stringent than BPT, allowing
as exemptions to zero discharge a similar unlimited discharge for
stormwater {except the allowance is for a volume of wastewater in
excess of a 25-year, 10-hour storm), and a further discharge
during any calendar month equal in volume to the difference
between precipitation on and evaporation from the impoundment
during that month. This latter discharge is subject to
concentration-based limitations.
Primary Electrolytic Copper Refining. Existing regulations cover
BPT and BAT. The BPT regulation for this subcategory allowed a
mass-based continuous discharge based on lime precipitation and
sedimentation. 45 FR 44926 (July 2, 1980). The BAT regulation,
promulgated earlier (40 FR 8524 (February 27, 1975)) was
impoundment rather than hardware-based, and established a mass-
based continuous discharge limitation, based on flow reduction,
lime precipitation, sedimentation, and the same allowances for
catastrophic stormwater discharge and net precipitation discharge
described for primary copper smelting, previously. (Refiners
located in areas of net evaporation, however, cannot discharge
process wastewaters, based on the use of solar evaporation. The
monthly net precipitation and catastrophic discharges may be
discharged.)
Secondary Copper. EPA established BPT, BAT and PSES in this
subcategory. BPT and BAT, based on the presence of impoundments
(or cooling tower circuits), required no discharge of process
wastewater pollutants with allowances for catastrophic stormwater
discharge and net precipitation discharge as described above when
impoundments are used instead of cooling tower circuits. See 40
FR 8526 (February 27, 1975). PSES, promulgated later (41 FR
54854 (December 15, 1976)) was based on lime precipitation and
sedimentation.
Primary Lead¦ The existing BPT and BAT limitations in zhis
subcategory were based on impoundments. See 40 FR (February 27,
1975). These limitations recu i r ed no discharge of process
wastewater pollutants, with exemptions for catastophic stormwater
and net precipitation discharge of acid plant blowdown (subject
to mass limitations) and monthly net precipitation on
impoundments. The existing limitations did net apply to primary
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GENERAL DEVELOPMENT DOCUMENT SECT - III
lead refineries not on-site with a smelter.
Primary Zinc. EPA promulgated BPT and BAT in this subcategory.
See 40 FR 8528 (February 27, 1975). This limitation was based on
lime precipitation and sedimentation technology for BPT, with
flow reduction added for BAT.
Metallurgical Acid Plants. This subcategory was established in
1980, and at that time included only acid plants (i.e., plants
recovering by-product sulfuric acid from sulfur dioxide smelter
air emissions) associated with primary copper smelting opera-
tions. (See 45 FR 44926.) Primary lead and zinc plants also
have associated acid plants; the applicability of the
metallurgical acid plants subcategory was expanded to include
these sources and was finalized on March 8, 1984 (49 FR 8742).
EPA further expanded the existing regulation for metallurgical
acid plants by modifying the applicability of the metallurgical
acid plants subcategory to include molybdenum acid plants.
METHODOLOGY
Approach of Study
The nonferrous metals manufacturing category comprises plants
that process ore concentrates and scrap metals to recover and
increase the metal purity contained in these materials. The
promulgated effluent limitations and standards for nonferrous
metals manufacturing addresses 31 subcategories (See Table 1-3,
page 15).
The 31 subcategories in nonferrous metals manufacturing contain
38 primary metals and metal groups, 24 secondary metals and metal
groups, and bauxite refining. A group of metals— including six
primary metals and five secondary metals—were excluded from
regulation either because the manufacturing processes do not use
water or because they are regulated by toxics limitations and
standards in other categories (e.g., ferroalloys and inorganic
chemicals). Four of these metals which were excluded from
regulation on May 10, 1979 — primary antimony, primary tin,
secondary molybdenum, and secondary tantalum — have since been
reconsidered based on information received during more recent
data collection efforts. EPA also studied the segments of the
nonferrous metals industry associated with forming or casting
nonferrous metals. EPA promulgated regulations for aluminum
forming (48 FR 49126) in October, 1983; for copper forming (48 FR
36942) in August, 1983; for metal molding and casting (50 FR
45212) October, 1985; and for forming of nonferrous metals other
than aluminum and copper (50 FR 34242) in August, 1985.
In the course of developing these guidelines, EPA gathered and
evaluated technical data in order to perform the following tasks:
1. To profile the category with regard to the production,
manufacturing processes, geographical distribution, potential
wastewater streams, and discharge mode of nonferrous metals
25
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GENERAL DEVELOPMENT DOCUMENT SECT - III
manufacturing plants.
2. To subcategorize, if necessary, in order to permit
regulation of the nonferrous metals manufacturing category in an
equitable and manageable way.
3. To characterize wastewater, detailing water use, wastewater
discharge, and the occurrence of toxic, conventional, and
nonconventional pollutants, in waste streams from nonferrous
metals manufacturing processes.
4. To select pollutant parameters — those toxic,
nonconventional, or conventional pollutants present at
significant concentrations in wastewater streams — that should
be considered for regulation,
5. To consider control and treatment technologies and select
alternative methods for reducing pollutant discharge in this
category,
6. To evaluate the costs of implementing the alternative
control and treatment technologies.
7. To present regulatory alternatives.
Data Collection and Methods of Evaluation
Data on the nonferrous metals manufacturing category were gath-
ered from previous EPA studies, literature studies, inquiries to
federal and state environmental agencies, trade association con-
tacts and the manufacturers themselves. Meetings were also held
with industry representatives and the EPA. All known companies
within the nonfer rous metals manufacturing category were sent
data collection portfolios to solicit specific information con-
cerning each facility. Finally, a sampling program was carried
out at 84 plants. Wastewater samples were collected in three
phases. In the first phase, 30 plants were sampled in an attempt
tov characterize all the significant waste streams and production
processes in these segments. In the second phase, 46 plants were
sampled to expand the data base, and to confirm data acquired
during the first phase of sampling. The third stage consisted of
a plant self-sampling effort, in which eight plants submitted
data on specific waste streams for which EPA had not previously
acqui red analytical data. These data were used to confirm
assumptions made in developing the limitations. Samples were
generally analyzed for 124 of the 126 toxic pollutants and other
pollutants deemed appropriate. Because no analytical standard
was available for TCDD, samples were never analyzed for this
pollutant, although there is no reason that it would be present
in nonferrous metals manufacturing wastewater. Asbestos was not
analyzed for in any of the samples because there was no reason to
believe it would be present in wastewater resulting from the
manufacture of nonferrous metals. At least one plant in every
major subcategory was sampled during the data collection effort,
with some subcategories sampled at more than one plant, when the
26
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GENERAL DEVELOPMENT DOCUMENT SECT - III
production processes were different.
Specific details of the sampling program and information from the
above data sources are presented in Section V. Details on selec-
tion of plants for sampling, and analytical results, are con-
tained in Section V of each of the subcategory supplements.
Literature Review. EPA reviewed and evaluated existing litera-
ture for background information to clarify and define various
aspects of the nonferrous metals manufacturing category and to
determine general characteristics and trends in production pro-
cesses and wastewater treatment technology. Review of current
literature continued throughout the development of these limita-
tions and standards. Information gathered in this review was
used, along with information from other sources as discussed
below, in the following specific areas:
Subcategory Profile (Section III of each of the subcategory
supplements) - Description of production processes and the
associated raw materials and wastewater streams.
Subcategorization (Section IV of each of the subcategory
supplements) - Identification of differences in manufac-
turing process technology and their potential effect on
associated wastewater streams.
Selection of Pollutant Parameters (Section VI) - Infor-
mation regarding the toxicity and potential sources of
the pollutants identified in wastewater from nonferrous
metals manufacturing processes.
Control and Treatment Technology (Section VII) - Infor-
mation on alternative controls and treatment and
corresponding effects on pollutant removal.
Costs (Section VIII) - Formulation of the methodology
for determining the current capital and annual costs to
apply the selected treatment alternatives.
Existing Data. Previous EPA studies of the following nonferrous
metals manufacturing subcategories were reviewed:
Primary Aluminum
Secondary Aluminum
Primary Copper
Secondary Copper
Primary Lead
Primary Zinc
Secondary Lead
Primary Columbium-Tantalum
Primary Beryllium
Primary and Secondary Germanium
Primary Magnesium
Secondary Zinc
Primary Zirconium and Hafnium
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GENERAL DEVELOPMENT DOCUMENT SECT - III
The available information included a summary of the category
describing the production processes, the wastewater
characteristics associated with the processes, recommended
pollutant parameters requiring control; applicable end-of-pipe
treatment technologies for wastewaters; effluent characteristics
resulting from this treatment, and a background bibliography.
Also included in these studies were detailed production and
sampling information for many plants.
The concentration or mass loading of pollutant parameters in
wastewater effluent discharges are monitored and reported as
required by individual state agencies. Where available, these
historical data were obtained from NPDES monitoring reports and
reviewed.
Other useful data sources were industry personnel and trade
associations. Contributions from these sources were particularly
useful for clarifying differences in production processes.
Finally, general information was derived from publications of the
U.S. Bureau of Mines, including the Minerals Yearbook and
supplements, and through discussions with commodity experts at
the U.S. Bureau of Mines.
Data Collection Portfolios¦ EPA conducted a survey of the non-
ferrous- metals manufacturing plants to gather information
regarding plant size, age and production, the production proces-
ses used, economic parameters, and the quantity, treatment, and
disposal of wastewater generated at these plants. This informa-
tion was requested in data collection portfolios (dcp) mailed to
all companies known or believed to belong to the nonferrous
metals manufacturing category. A listing of the companies
comprising the nonferrous metals industry (as classified by
standard industrial code numbers) was compiled by consulting
trade associations and the U.S. Bureau of Mines.
In all, dcp were sent to 540 firms (693 plants). In some cases,
companies contacted were not actually members of the nonferrous
metals manufacturing category as it is defined by the Agency.
Where firms had nonferrous metals manufacturing operations at
more than one location, a dcp was returned for each plant.
If the dcp was not returned, information on production processes,
sources of wastewater and treatment technology at these plants
was collected by telephone interview. The information so
gathered was validated by sending a copy of the information
recorded to the party consulted. The information was assumed to
be correct as recorded if no reply was received in 30 days. In
total, more than 99 percent of the category was contacted either
by mail or by telephone.
A total of 450 dcp applicable to the nonferrous metals manufac-
turing category were returned. A breakdown of these facilities
by type of metal processed is presented in Table III-l (page 32).
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GENERAL DEVELOPMENT DOCUMENT SECT - III
The dcp responses were interpreted individually, and the follow-
ing data were documented for future reference and evaluation;
Company name, plant address, and name of the contact
listed in the dcp.
Plant discharge status as direct (to surface water),
indirect (to POTW), or zero discharge.
Production process and waste streams present at the
plant, as well as associated flow rates; production
rates; operating hours; wastewater treatment, reuse,
or disposal methods; and the quantity and nature of
process chemicals.
Capital and annual wastewater treatment costs.
Availability of pollutant monitoring data provided by the
plant.
The summary listing of this information provided a consistent,
systematic method of evaluating and summarizing the dcp
responses. In addition, procedures were developed to simplify
subsequent analyses, which had the following capabilities:
Selection and listing of plants containing specific pro-
duction process streams or treatment technologies.
Summation of the number of plants containing specific
process waste streams and treatment combinations.
Calculation of the percent recycle present for specific
waste streams and summation of the number of plants
recycling these waste streams within various percent
recycle ranges.
Calculation of annual production values associated with
each process stream and summation of the number of plants
with these process streams having production values
within various ranges.
Calculation of water use and discharge from individual
process streams.
The calculated information and summaries were used in developing
these effluent limitations and standards. Summaries were used in
the category profile, evaluation of subcategorization, and analy-
sis of in-place treatment and control technologies. Calculated
information was used in the determination of water use and dis-
charge values for the conversion of pollutant concentrations to
mass loadings.
GENERAL PROFILE OF THE NONFERROUS METALS MANUFACTURING CATEGORY
The nonferrous metals manufacturing point source category encom-
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GENERAL DEVELOPMENT DOCUMENT SECT - III
passes the primary smelting and refining of nonferrous metals
(Standard Industrial Classification (SIC) 333) and the secondary
smelting and refining of nonferrous metals (SIC 334). The cate-
gory does not include the mining and concentration of ores, roll-
ing, drawing, or extruding of metals, or scrap metal collection
and preliminary grading.
Nonferrous metal manufacturers include processors of ore concen-
trates or other virgin materials (primary) and processors of
scrap (secondary). Metals produced as by- or co-products of pri-
mary metals are themselves considered primary metals. For exam-
ple, rhenium recovered from primary molybdenum roaster flue gases
is considered to be primary rhenium, rather than secondary. Table
III-l (page 32) summarizes the nonferrous metals manufacturers
studied by the type of metal processed.
The nonferrous metals manufacturing category is quite complex and
the production process for a specific metal is dictated by the
characteristics of raw materials, the economics of by-product
recovery, and the process chemistry and metallurgy of the metals.
Employment data are given in the dcp responses for 456 plants.
These plants report a total of 74,500 workers involved in nonfer-
rous metals manufacturing plants. Industry production figures
show that bauxite refining and primary aluminum dominates the
industry in terms of tonnage. Other subcategories with large
production figures are primary copper, lead, zinc and molybdenum.
Two hundred thirteen plants (47 percent) indicated that no
wastewater from nonferrous metals manufacturing operations is
discharged to either surface waters or a POTW. Of the remaining
243 plants, 112 (25 percent) discharge an effluent from
nonferrous metals manufacturing directly to surface waters, and
131 (28 percent) discharge indirectly, sending nonferrous metals
manufacturing effluent through a POTW.
EPA recognizes that plants sometimes combine process and non-
process wastewater prior to treatment and discharge. Pollutant
discharge allowances will be established under this regulation
only for nonferrous metals manufacturing process wastewater, not
the nonprocess wastewaters. The nonprocess flows and wastewater
characteristics are a funct ion of the plant layout and water
handling practices. As a result, the pollutant discharge
effluent limitation for nonprocess wastewater streams will be
prepared by the permitting authority. A discussion of how a
permit writer would construct a permit for a facility that
combines wastewater is presented in Section IX.
Section III of each of the subcategory supplements presents a
detailed profile of the plants in each subcategory and describes
the production processes involved. In addition, the following
specific information is presented;
1. Raw materials,
2. Manufacturing process,
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GENERAL DEVELOPMENT DOCUMENT SECT - III
3. Geographic locations of manufacturing plants,
4. Age of plants by discharge status,
5. Production ranges by discharge status, and
6. Summary of waste streams for each process.
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GENERAL DEVELOPMENT DOCUMENT SECT - III
Table III-l
SUMMARY OF DCP RESPONDENTS BY TYPE OF METAL PROCESSED
Number
Subcategory of Plants
Bauxite Refining 8
Primary Aluminum Smelting 33
Secondary Aluminum Smelting 59
Primary Copper Smelting 21
Primary Electrolytic Copper Refining 17
Secondary Copper 31
Primary Lead 9
Secondary Lead 73
Primary Zinc 8
Primary Tungsten 18
Primary Columbium-Tantalum 5
Secondary Silver 81
Metallurgical Acid Plants 29
Primary Antimony 8
Primary Beryllium 2
Primary and Secondary Germanium and Gallium 5
Secondary Indium 1
Secondary Mercury 4
Primary Molybdenum and Rhenium 9
Secondary Molybdenum and Vanadium 1
Primary Nickel and Cobalt 1
Secondary Nickel 2
Primary Precious Metals and Mercury 8
Secondary Precious Metals 49
Primary Rare Earth Metals 4
Secondary Tantalum 3
Secondary Tin 12
Primary and Secondary Titanium 8
Secondary Tungsten and Cobalt 6
Secondary Uranium 3
Primary Zirconium and Hafnium 3
TOTAL 521
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GENERAL DEVELOPMENT DOCUMENT SECT - IV
SECTION IV
INDUSTRY SUBCATEGORIZATION
Subcategorization should take into account pertinent industry
characteristics, manufacturing process variations, wastewater
characteristics, and other factors. Effluent limitations and
standards establish mass limitations on the discharge of pollu-
tants which are applied, through the permit issuance process, to
specific dischargers. To allow the national standard to be
applied to a wide range of sizes of production units, the mass of
pollutant discharge must be referenced to a unit of production.
This factor is referred to as a production normalizing parameter
and is developed in conjunction with subcategorization.
Division of the category into subcategories provides a mechanism
for addressing process and product variations which result in
distinct wastewater characteristics. The selection of production
normalizing parameters provides the means for compensating for
differences in production rates among plants with similar prod-
ucts and processes within a uniform set of mass-based effluent
limitations and standards.
This subcategorization analysis is actually an ongoing process.
The first subcategories (bauxite refining, primary aluminum
smelting, and secondary aluminum smelting) were established in a
1973 Agency rulemaking. Since that time, some subcategories have
been modified. New subcategories were added in 1975 and then
again in 1980.
A comprehensive analysis of each factor that might warrant sepa-
rate limitations for different segments of the industry has led
the Agency to promulgate the following subcategorization scheme
for BPT and BAT effluent limitations guidelines and PSNS, PSES,
and NSPS in the nonferrous metals manufacturing category. (See
listing in Table V-l, page 48)
Most of these subcategories are further segmented into
subdivisions for the development of effluent limitations; these
subdivisions are enumerated and discussed in the subcategory
supplements to this document.
SUBCATEGORIZATION BASIS
Technology-based effluent limitations are based primarily upon
the treatability of pollutants in wastewaters generated by the
category under review. The treatability of these pollutants is,
of course, directly related to the flow and characteristics of
the untreated wastewater, which in turn can be affected by fac-
tors inherent to a processing plant in the category. Therefore,
these factors and the degree to which each influences wastewater
flow and characteristics form the basis for subcategorization of
the category, i.e., those factors which have a strong influence
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GENERAL DEVELOPMENT DOCUMENT
SECT - IV
on untreated wastewater flow and characteristics are applied to
the category to subcategorize it in an appropriate manner.
The list of potential subcategorization factors considered for
the nonferrous metals manufacturing category include:
Metal products, co-products, and by-products;
Raw materials:
Manufacturing processes;
Product form;
Plant location;
Plant age;
Plant size;
Air pollution control methods;
Meteorological conditions;
Treatment costs;
Solid waste generation and disposal;
Number of employees;
Total energy requirements (manufacturing process and
wastewater treatment and control); and
Unique plant characteristics.
For the reasons discussed below, the metal or other products, the
raw materials, and the manufacturing process were discovered to
have the greatest influence on wastewater flow characteristics
and treatability, and thus ultimately on the appropriateness of
effluent limitations. These three factors were used to
subcategorize the category. As mentioned previously, further
division of some subcategories is warranted based on the sources
of waste waters {manufacturing processes) within the plant. Each
manufacturing process generates differing amounts of wastewater
and in some instances specific waste streams conta i n pol lutar.ts
requiring preliminary treatment to reduce concentrations of oil
and grease, ammonia, cyanide, and toxic organics prior to
combined treatment. Thus, each subcategory is further subdivided
based on the manufacturing processes used. These subdivisions
are discussed in the appropriate supplement.
Metal Products, Co-Products, and By-Products
The metal products, co-products, and by-products is the most
important factor in identifying subcategories for this category,
Subcategorizing on this basis is consistent with the existing
division of plants, i.e., plants are identified as {and identify
themselves as) nickel plants, tin plants, titanium plants, etc.
The production of each metal is based on its own raw materials
and production processes, which directly affect wastewater volume
and characteristics.
In nonferrous metals manufacturing, production and refining of
metal by-products and co-products generally will be covered by
means of subcategorization with the major metal product. There
are several examples of this. EPA found that production of the
co-product metals primary zirconium and hafnium are inherently
allied, so both were considered in a single subcategory. The
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GENERAL DEVELOPMENT DOCUMENT SECT - IV
same is true for primary molybdenum and rhenium, primary nickel
and cobalt, primary precious metals and mercury, and primary rare
earth metals. Secondary cobalt is a by-product of the secondary
tungsten manufacturing process, thus, the two are placed together
in one subcategory.
Raw Materials
The raw materials used (ore concentrates or scrap) in nonferrous
metals manufacturing determine the reagents used, and to a large
extent the wastewater characteristics. Raw materials are signi-
ficant in differentiating between primary and secondary produc-
ers. It is therefore selected as a basis for subcategorization.
In some cases (e.g., primary and secondary titanium), the raw
material differences did not warrant separate subcategorization
due to common processing steps or other factors.
Manufacturing Processes
The production processes for each metal are unique and are
affected by the raw materials used and the type of end product.
The processes used will, in turn, affect the volume and charac-
teristics of the resulting wastewater.
The processes performed (or the air pollution controls used on
the process emissions) in the production of nonferrous metals
determine the amount and characteristics of wastewater generated
and thus are a logical basis for the establishment of subcate-
gories. In this category, however, similar processes may be
applied to differing raw materials in the production of different
metals yielding different wastewater characte r ist i.cs . For exam-
ple, molybdenum, precious metals, and tin may all be produced by
roasting. As a result of these considerations, specific process
operation was not generally found to be suitable as a primary
basis for subcategorization. However, process variations which
result in significant differences in wastewater generation are
reflected in the allowances for discrete unit operations within
each subcategory (see the discussion of building blocks in
Section IX).
In the case of primary copper manufacturing, the production
processes used are deemed to be a reasonable basis for
subcategorization, even though these processes are sometimes
practiced at a single site. This resulted in the establishment
of the primary copper smelting subcategory and the primary copper
electrolytic refining subcategory (see Section IV of the Primary
Copper Supplement). This is consistent with the structure of the
category since smelting and refining are often conducted at
different sites.
Product Form
This factor becomes important when the final product from a plant
is actually an intermediate that another plant purchases and pro-
cesses to render the metal in a different form. An example of
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GENERAL DEVELOPMENT DOCUMENT SECT - IV
this is the production of molybdenum, which some plants produce
by reducing molybdenum trioxide (M0O3), an intermediate that may
have been produced by another plant. This practice, however, is
not found to be common in the category and its effect on
wastewater volume and total subcategory raw waste generation is
not as significant as the factors chosen.
Plant Location
Most plants in the category are located near raw materials
sources, transportation centers, markets, or sources of inexpen-
sive energy. While larger primary copper, lead, zinc, molybdenum
and titanium producers are mainly found near Mid-western and
Western ores and are remote from population centers, proximity to
shipping lanes in the lower Mississippi region is important for
bauxite refiners. Secondary producers, on the other hand, are
generally located in or near large metropolitan areas.
Therefore, primary producers often have more land available for
treatment systems than secondary producers. Plant location also
may be significant because evaporation ponds can be used only
where solar evaporation is feasible and where sufficient land is
available. However, location does not significantly affect
wastewater characteristics or treatability, and thus different
effluent limitations are not warranted based on this factor.
Plant Age
Plants within a given subcategory may have significantly
different ages in terms of initial operating year. To remain
competitive, however, plants must be constantly modernized.
Plants may be updated by modernizing a particular component, or
by installing new components. For example, an old furnace might
be equipped with oxygen lances to increase the throughput, or
replaced entirely by a new, more efficient furnace. Moderniza-
tion of production processes and air pollution control equipment
produces analogous wastes among all plants producing a given
metal, despite the original plant start-up date. While the rela-
tive age of a plant may be important in considering the economic
impact of a guideline, as a subcategorization factor it does not
account for differences in the raw wastewater characteristics.
For these reasons, plant age is not selected as a basis for
subcategorization.
Plant Size
The size of a plant generally does not affect either the produc-
tion methods or the wastewater characteristics. Generally, more
water is used at larger plants. However, when water use and
discharge are normalized on a production basis, no major differ-
ences based on plant size are found within the same subcategory.
Thus, plant size is no: selected as a basis for subcategoriza-
tion .
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GENERAL DEVELOPMENT DOCUMENT SECT - IV
Air Pollution Control Methods
Many facilities use wet scrubbers to control emissions which
influence wastewater characteristics. In some cases, the type of
air pollution control equipment used provides a basis for regula-
tion, because if wet air pollution control is used, an allowance
may be necessary for that waste stream, while a plant using only
dry systems does not need an allowance for a non-existent waste
stream. Therefore, this factor is often selected as a basis for
subdivision within some subcategories (i.e., developing an allow-
ance for this unit operation as part of the limitation or stan-
dard for the subcategory), but not as a means for subcategorizing
the category.
Meteorological Condit ions
Climate and precipitation may affect the feasibility of certain
treatment methods, e.g., solar evaporation through the use of
impoundments is a feasible method of wastewater treatment only in
areas of net evaporation. This factor was not selected for sub-
categor ization, however, because the differences in wastewater
characteristics and treatability are better explained by other
factors such as metal products and manufacturing processes.
Therefore, different effluent limitations based on this factor
are not warranted.
Solid Waste Generation and Disposal
Physical and chemical characteristics of solid waste generated by
the nonferrous metals category are determined by the raw
material, process, and type of air pollution control in use.
Therefore, this factor does not provide a primary basis for
subcategor izat ion.
Number of Employees
The number of employees in-a plant does not directly provide a
basis for subcategorization because the number of employees does
not directly affect the production or process water usage rate at
any plant. Because the amount of process wastewater generated is
related to the production rates rather than employee number, the
number of employees does not provide a definitive relationship to
wastewater generation.
Total Energy Requirements
Total energy requirements was not selected as a basis for sub-
categorization primarily because energy requirements are found to
vary widely within this category and are not meaningfully related
to wastewater generation and pollutant discharge. Additionally,
it is often difficult to obtain reliable energy estimates spe-
cifically for production and waste treatment. When available,
estimates are likely to include other energy requirements such as
lighting, air conditioning, and heating or cooling energy.
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GENERAL DEVELOPMENT DOCUMENT SECT - IV
Unique Plant Characteristics
Unique plant characteristics such as land availability and water
availability do not provide a proper basis for subcategorization
because they do not materially affect the raw wastewater charac-
teristics of the plant. Process water availability may indeed be
a function of the geography of a plant. However, the impact of
limited water supplies is to encourage conservation by recycle
and efficient use of water. Therefore, insufficient water
availability only tends to encourage the early installation of
practices that are advisable for the entire category in order to
reduce treatment costs and improve pollutant removals.
Limited land availability for constructing a waste treatment
facility may affect the economic impact of an effluent limita-
tion. The availability of land for treatment, however, is gen-
erally not a major issue in the nonferrous metals manufacturing
category. Most primary plants are located on very large sites
and land availability would not be a factor. While secondary
producers tend to be located in more urban settings, the amount
of land available to them for treatment is sufficient for the
types of treatment and control technologies considered.
PRODUCTION NORMALIZING PARAMETERS
To ensure equitable regulation of the category, effluent guide-
lines limitations and standards of performance are established on
a production-related basis (i.e., a mass of pollutant per unit of
production). In addition, by using these mass-based limitations
the total mass of pollutants discharged is minimized. The under-
lying premise for mass-based limitations is that pollutant load-
ings and water discharged from each process are correlated to the
amount of material produced by that process. This correlation is
calculated as the mass of pollutant or wastewater discharged per
unit of product ion. The units of production are known as produc-
tion normalizing parameters (PNFs). The type and value of the
PNPs vary according to the subcategory or subdivision. In one
case it may be the total mass of metal produced from that line
while in others it may be some other characteristic parameter.
Two criteria are used in selecting the appropriate PNP for a
given subcategory or subdivision: (1) maximizing the degree of
correlation between the production of metal reflected by the PNP
and the corresponding discharge of pollutants, and (2) ensuring
that the PNP is easily measured and feasible for use in
establishing regulations.
The production normalizing parameter identified for each
subcategory or subdivision, and the rationale used in selection
are discussed in detail in Section IV of the appropriate
supplements.
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GENERAL DEVELOPMENT DOCUMENT SECT - V
SECTION V
WATER USE AND WASTEWATER CHARACTERISTICS
This section presents the data collection and data analysis
methods used for characterizing water use and wastewater
associated with the nonferrous metals manufacturing category.
Raw waste and treated effluent sample data, and production
normalized water use and wastewater discharge data are presented
in Sect ion V of each of the subcategory supplements.
DATA SOURCES
Historical Data
A useful source of long-term or historical data available for
nonferrous metals manufacturing plants are the Discharge
Monitoring Reports (OMR's) completed as a part of the National
Pollutant Discharge Elimination System (NPDES). All applicable
DMR's were obtained through the EPA regional offices and state
regulatory agencies for the year 1982, the last complete year
prior to the proposal of the first segment (Phase I) of this
regulation for which information was available. These data were
available from 14 nonferrous metals manufacturing plants. The
DMR's present a summary of the analytical results from a series
of samples taken during a given month for the pollutants
designated in the plant's permit. In general, minimum, maximum,
and average values, in rng/1 or lbs/day, are presented for such
pollutants as total suspended solids, aluminum, oil and grease,
pH, copper, and zinc. The samples are collected from the plant
outfall ( s ) , which represents the discharged ) from the plant.
For facilities with wastewater treatment, the DMR's provide a
measure of the performance of the treatment system. In theory,
these data could then serve as a basis for characterizing treated
wastewater from nonferrous metals manufacturing plants; however,
there is no influent to treatment information (i.e., paired
influent-effluent data) and too little information on the
performance of the plant at the time the samples were collected
to be the preferred source of data in formulating achievable
performance for various types of treatment. They do serve as a
set of data that can be used to verify the technology
performances presented in Section VII, Control and Treatment
Technology (Table VII-21, page 248). DMR data from 12 plants
with lime precipitation and sedimentation treatment were used as
a check on the achievability of the treatment effectiveness
concentrations used to establish the limitations and standards.
These DMR data and a comparison of them to the treatment
effectiveness concentrations are found in the record of this
rulemak ing.
Data Collection Portfolios
Information on plant location and size, number of employees, dis-
39
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GENERAL DEVELOPMENT DOCUMENT SECT - V
charge status, production processes and quantities, wastewater
sources and flows, treatment system processes, operations and
costs, economic information, and pollutant characterization data
was solicited in the data collection portfolio (dcp).
Two of the most important items are the production processes and
quantities and the associated flows. These data were evaluated,
and two flow-to-production ratios were calculated for each stream
in each subcategory. The two ratios, water use and wastewater
discharge flow, are differentiated by the flow value used in cal-
culation. Water use is defined as the volume of water or other
fluid required for a given process per mass of metal product and
is therefore based on the sum of recycle and make-up flows to a
given process. Wastewater flow discharged after preliminary
treatment or recycle (if these are present) is the volume of
wastewater discharged from a given process to further treatment,
disposal, or discharge per mass of metal produced. The production
values used in this calculation correspond to the production
normalizing parameter, PNP, assigned to each stream, as outlined
in Section IV of each of the subcategory supplements. This value
is most often the amount of metal processed by each operation
that generates a wastewater.
The production normalized water use and discharge flows were com-
piled and summarized for each stream. The flows are presented in
Section V of each of the subcategory supplements. Where appro-
priate, an attempt was made to identify factors that could
account for variations in water use. The flows for each stream
were evaluated to establish BPT, BAT, NSPS, and pretreatment dis-
charge flows. These are used in calculating the effluent limita-
tions and standards in Sections IX, X, XI, and XII of each of the
subcategory supplements.
The regulatory production normalized discharge flows were also
used to estimate flows at nonferrous metals manufacturing plants
that supplied EPA with only production data in their dcp. Actual
discharge flows, or estimated flows, when an actual flow was not
reported in the dcp, were then used to determine the cost of
various wastewater treatment options at these facilities.
Sampling and Analysis Program
The sampling and analysis program discussed in this section was
undertaken to collect specific data to implement the requirements
of the 1977 amendments to the Act and to identify pollutants of
concern in the nonferrous metals manufacturing point source
category, with emphasis on toxic pollutants. EPA and its
contractors collected and analyzed samples from 84 nonferrous
metals manufacturing facilities.
This section summarizes the purpose of the sampling trips and
identifies the parameters analyzed. It also presents an overview
of sample collection, preservation, and transportation
techniques. Finally, it describes the pollutant parameters
quantified, the methods of analyses and laboratories used, the
40
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GENERAL DEVELOPMENT DOCUMENT SECT - V
detectable concentration of each pollutant, and the general
approach used to ensure the reliability of the analytical data
produced.
Site Selection. Information gathered in the data collection
portfolios was used to select sites for wastewater sampling for
each subcategory. The plants sampled were selected to be
representative of each subcategory. Considerations included how
well each facility represented the subcategory as indicated by
available data, potential problems in meeting technology-based
standards, differences in production processes used, number and
variety of unit operations generating wastewater, and wastewater
treatment in place. Additional details on site selection are
presented in Section V of each of the subcategory supplements.
Field Sampling. After plants to be sampled were selected, each
plant was contacted by telephone, and sent a letter of
notification as to when a visit would be expected. These
telephone inquiries4disclosed facility information necessary for
efficient on-site sampling. Based on this information, the
sources of wastewater to be sampled at each plant were selected.
The sample points included, but were not limited to, untreated
and treated discharges, process wastewater, and partially treated
wastewater.
During this program, 84 nonferrous metals manufacturing plants
were sampled. The distribution of these plants by subcategory is
presented in Table V-l (page 48).
Wastewater samples were collected in three stages. In the first
stage, 30 plants were sampled in an attempt to characterize all
the significant waste streams and production processes in these
industries. In the second stage, 46 plants were sampled in an
attempt to fill any gaps in the data base, and to confirm data
acquired during the first phase of sampling. In the third stage,
EPA conducted a small plant self-sampling effort under Section
308 of the Clean Water-Act. In this effort eight plants submitted
data on specific waste streams for which EPA had not previously
acquired analytical data. These data were used to confirm
assumptions made by EPA in developing the limitations. Samples
were generally analyzed for 124 (excluding TCDD and asbestos) of
the 126 toxic pollutants and other pollutants deemed appropriate.
Because no analytical standard was available for TCDD, samples
were never analyzed for this pollutant, although there is no
reason that it would be present in nonferrous metals
manufacturing wastewater. Also, no samples were analyzed for
asbestos because there is no reason to believe that asbestos
would be present in wastewater resulting from :.he manufacture of
nonferrous metals. At least one plant in every major subcategory
was sampled during the data collection effort, with some
subcategories sampled at more than one plant, when the produc-
tion processes were different.
To reduce the volume of data handled, avoid unnecessary expense,
and direct the scope of the sampling program, analyses were only
41
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GENERAL DEVELOPMENT DOCUMENT SECT - V
performed for pollutants expected to be present in a plant's
wastewater. Two sources of information were used for selecting
the analyzed pollutants: the pollutants that industry believes
or knows are present in their wastewater, and the pollutants the
Agency believes could be present after studying the processes and
materials used by the industry. If industry and the Agency did
not believe a pollutant or class of pollutants likely to be
present in the wastewater after studying the processes and
materials used, analyses for that pollutant were not completed.
The 126 toxic pollutants were listed in each dcp and each facil-
ity was asked to indicate for each particular pollutant whether
it was known to be present or believed to be present. If the
pollutant had been analyzed for and detected, the facility was to
indicate that it was known to be present. If the pollutant had
not been analyzed, but might be present in the wastewater, the
facility was to indicate that it was believed to be present. The
reported results are tabulated in Section V of the subcategory
supplements.
Sample Collection, Preservation, and Transportation. Samples
were collected, preserved, and transported in accordance with
procedures outlined in Appendix III of "Sampling and Analysis
Procedures for Screening of Industrial Effluents for Priority
Pollutants" (published by the Environmental Monitoring and
Support Laboratory, Cincinnati, Ohio, March 1977, revised, April
1977), "Sampling Screening Procedure for the Measurement of
Priority Pollutants" (published by the EPA Effluent Guidelines
Division, Washington, D.C., October 1976), Handbook for Sampling
and Sample Preservation of Water and Wastewater (published by the
Environmental Monitoring and Support Laboratory, Cincinnati,
Ohio, September 1982) and in "Methods for Chemical Analysis of
Water and Wastes", USEPA, EMSL, Cincinnati, Ohio 45268, EPA-
600/4-79-020 (March 1983); "Guidelines Establishing Test
Procedures for the Analysis of Pollutants Under the Clean Water
Act", 49 FR 43234 (October 26, 1984). The procedures are
summarized below.
Whenever practical, all samples collected at each sampling point
were taken from mid-channel at mid-depth in a turbulent, well-
mixed portion of the waste stream. Periodically, the temperature
and pH of each waste stream sampled were measured onsite.
Before collection of automatic composite samples, new Tygon
tubing was cut to minimum lengths and installed on the inlet and
outlet (suction and discharge) fittings of the automatic sampler.
Two liters (2.1 quarts) of blank water, known to be free of
organic compounds and brought to the sampling site from the
analytical laboratory, were pumped through the sampler ana its
attached tubing into a 3.8 liter (1 gallon) glass jug; the water
was then distributed to cover the interior of the jug and
subsequently discarded.
A field blank sample was produced by pumping an additional three
liters (0.8 gal) of blank water through the sampler into the
42
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GENERAL DEVELOPMENT DOCUMENT SECT - V
glass jug. The blank sample was sealed with a Teflon-lined cap,
labeled, and packed in ice in a plastic foam-insulated chest.
This sample subsequently was analyzed to determine any contamina-
tion contributed by the automatic sampler.
Each large composite (Type 1} sample was collected in a 10-liter
(2.6 gallon) wide-mouth glass jar that had been washed with
detergent and water, rinsed with tap water, rinsed with distilled
water and then methylene chloride, and air dried at room
temperature in a dust-free environment.
During collection of each Type 1 sample, the wide-mouth glass
jar was packed in ice in a separate plastic foam-insulated
container. After the complete composite sample had been
collected, it was mixed to provide a homogenous mixture, and l-
liter aliquots were removed for metals analysis and placed in two
new labeled plastic 1-liter bottles which had been rinsed with
distilled water. Both of the 1-liter aliquots were preserved by
the addition of 5 ml of concentrated nitric acid. The bottles
were then sealed, placed in an insulated chest and shipped for
metals analyses. These analyses include atomic absorption
spectrophotometry and inductively coupled argon plasma emission
spect roscopy (ICAP).
After removal of the two 1-liter metals aliquots from the compos-
ite sample, the balance of the sample in the glass jar was sub-
divided for analysis of nonvolatile organics, conventional, and
nonconventional parameters. If a portion of this sample was
requested by a plant representative for independent analysis, a
1-liter aliquot was placed in a sample container supplied by the
representative.
Sample Types 2 (cyanide) and 3 (total phenols) were stored in new
bottles which had been iced and labeled; 1-liter clear plastic
bottles for Type 2, and 1-liter amber glass for Type 3. The
bottles had been cleaned by rinsing with distilled water, and the
samples were preserved as described below.
To each Type 2 (cyanide) sample, sodium hydroxide was added as
necessary to elevate the pH to 12 or more (as measured using pH
paper). Where the presence of chlorine (which would decompose
most of the cyanide) was suspected, the sample was tested for
chlorine by using potassium iodide-starch paper. If the paper
turned blue, ascorbic acid crystals were slowly added and
dissolved until a drop of the sample produced no change in the
color of the test paper. An additional 0.6 gram (0.021 ounce) of
ascorbic acid was added, and each sample botr.le was sealed (by a
Teflon-lined cap), labeled, iced, and shipped for analysis.
To each Type 3 (total phenols) sample, sulfuric acid was added
as necessary to reduce the pH to 2 or less (as measured using pH
paper). Each sample bottle was sealed with a Teflon-lined cap,
labeled, iced, and shipped for analysis.
Each Type 4 (volatile organics) sample was stored in a new 40-ml
43
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GENERAL DEVELOPMENT DOCUMENT SECT - V
glass vial that had been rinsed with tap water and distilled
water, heated to 105°C (221°F) for one hour, and cooled.
The septum and lid for each bottle were also prepared by this
method. Each bottle, when used, was filled to overflowing,
sealed with a Teflon-faced silicone septum (Teflon side down),
capped,* labeled, and iced. Proper sealing was verified by
inverting and tapping the container to confirm the absence of air
bubbles. (If bubbles were found, the bottle was opened, a few
additional drops of sample were added, and proper sealing was
verified.) Samples were labeled, iced to 4°C, and sent for
analysis.
A 1-quart wide-mouth glass bottle was used to collect each grab
sample for oil and grease analysis. Because oil tends to form a
film on top of water in quiescent streams, the sample was col-
lected in an area of complete mixing. Sulfuric acid was added as
necessary to reduce the pH to less than 2. The sample bottle was
sealed with a Teflon-lined cap, labeled, iced to 4°C and shipped
for analysis.
Sample Analysis. Samples were shipped by air to laboratories
where inductively coupled argon plasma emission spectroscopy
(ICAP) and atomic absorption spectrophotometry (AA) analyses were
performed. The samples were analyzed only for metals shown to be
significant in the nonferrous metals manufacturing category or
those expected to consume large amounts of lime. Twenty-three
metals were analyzed by ICAP, and six metals were analyzed by AA,
as shown below. Total metals analysis was used for all samples.
Two nonconventional metal pol1utants (tantalum and tungsten) were
analyzed by X-ray fluorescence. Uranium was analyzed by
fluorometry.
Metals Analyzed by ICAP
Aluminum
Bar i um
~Beryllium
Boron
~Cadmium
Calcium
*Chromium
Cobalt
*Copper
Gold
I ron
*Lead
Metals An a 3. v zed by AA
*Ant imony
*Arsenic
*Mercury
44
Magnesium
Manganese
Molybdenum
~Nickel
Sodium
Tin
Titanium
Vanadium
Yttrium
*Z inc
Zi rconium
~Selenium
* Silver
*'Thall iun
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GENERAL DEVELOPMENT DOCUMENT
SECT - V
Metals Analyzed by X-Ray Fluorescence
Tantalum
Tungsten
Metals Analyzed by Fluorometry
Uran ium
*Priority pollutant metals.
Mercury was analyzed by cold vapor flameless atomic absorption
spect rophotomet ry.
Radium-226 was analyzed by the precipitation method. The refer-
ence for this method is the Interim Radiochemical Methodology.
Samples also went to laboratories for organics analysis. Due to
their very similar physical and chemical properties, it is
extremely difficult to separate the seven polychlorinated
biphenyls (pollutants 106 to 112) for analytical identification
and quantification. For that reason, the concentrations of the
polychlorinated biphenyls are reported by the analytical labora-
tory in two groups: one group consists of PCB-1222, PCB-1252,
and PCB-1221; the other group consists of PCB-1232 PCB-1248, PC8-
1260, and PCB-1016. For convenience, the first group has been
referred to as PCB-1254 and the second as PCB-1228.
The samples were not analyzed for Pollutant 129, 2,3,7,8-tetra-
chlorodibenzo-p-dioxin (TCDD) because no reference sample was
available to the analytical laboratory.
Three of the five conventional pollutant parameters were selected
for analysis for evaluating treatment system performance. They
are total suspended solids (TSS), oil and grease, and pK. The
other two conventionals, fecal coliform and biochemical oxygen
demand (BOD), were not measured because there is no reason to
believe that fecal matter or oxygen demanding biological mate-
rials would be present in these wastewaters. Ammonia, fluoride,
and total phenols (4-AAP) were analyzed for in selected samples
if there was reason to believe they would be present based on the
processes used. While not classified as toxic pollutants, they
affect the water quality. Chemical oxygen demand (COD) and total
organic carbon (TOC) were also selected for analysis for selected
samples for subsequent use in evaluating treatment system
performance. Total dissolved solids (TDS) was measured to
evaluate the potential for accumulation of dissolved salts.
In addition, chloride, alkalinity-acidity, total solids, total
phosphorus (as PO4), and sulfate were measured to provide data to
evaluate the performance and cost of line and settle treatment of
certain wastewater streams.
Samples were also analyzed for asbestos by transmission electron
microscopy. Total fiber and c'nrysotile fiber counts were
45
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GENERAL DEVELOPMENT DOCUMENT SECT - V
reported by the testing laboratory. Chrysotile was chosen by the
Agency as the screening parameter for asbestos for mining related
activities because: (1) of its known toxicity when particles are
inhaled, (2) its industrial prevalence, (3) its distinguishing
selected area electron diffraction (SAED) pattern, and (4) the
cumbersome nature of the transmission electron microscopic (TEM)
analysis technique limits the identification to one mineral form
at the present time due to economics and time constraints.
While the asbestos data vary, the testing laboratory's report
indicates that when the total fiber count is performed in
conjunction with a count of chrysotile fibers, a good initial
screening parameter is produced. The report recommends re-
examining any facility with chrysotile fiber counts greater than
100 million fibers per liter (MFL) because this represents a
significant departure from ambient counts of 3 MFL in the Great
Lakes Basin. The technique used had a threshold of detection of
0.22 MFL.
The analytical quantification limits used in evaluation of the
sampling data reflect the accuracy of the analytical methods
used. Below these concentration, the identification of the
individual compounds is possible, but quantification is
difficult. Pesticides and PCBs can be analytically quantified at
concentrations above 0.005 mg/1, and other organic priority
pollutants at concentrations above 0.010 mg/1. Analytical
quantification limits associated with priority inorganic
pollutants are as follows: 0.100 mg/1 for antimony; 0.10 mg/1
for arsenic; 10 MFL for asbestos; 0.010 mg/1 for beryllium; 0.002
mg/1 for cadmium; 0.005 mg/1 for chromium; 0.009 mg/1 for copper;
0.02 mg/1 for cyanide; 0.02 mg/1 for lead; 0.0001 mg/1 for
mercury; 0.005 mg/1 for nickel; 0.010 mg/1 for selenium; 0.020
mg/1 for silver; 0.100 mg/1 for thallium; and 0.050 mg/1 for
z inc.
These detection limits are not the same as published detection
limits for these pollutants by the same analytical methods (40
CFR Part 136 - Guidelines Establishing Test Procedures for the
Analysis of Pollutants; 40 CFR Part 136 - Proposed, 44 FR 69464,
December 3, 1979; 1982 Annual Book of ASTM Standards, Part 31,
Water, ASTM, Philadelphia, PA: "Methods for Chemical Analysis of
Water and Wastes," Environmental Monitoring and Support
Laboratory, Office of Research and Development, U.S. EPA
Cincinnati, OH, March, 1979, EPA-600 4-79-020; Handbook for
Monitoring Industrial Wastewater, U.S. EPA Technology Transfer,
August, 1973). The detection limits used were reported with the
analytical data and hence are the appropriate limits to apply to
the data. Detection limit variation can occur as a result of a
number of laboratory equipment and daily operator-specific
factors, such as day-to-day differences in machine calibration,
variation in stock solutions, and variation in operators.
Quality Control. Quality control measures used in performing all
analyses conducted for this program complied with the guidelines
given in "Handbook for Analytical Quality Control in Water and
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GENERAL DEVELOPMENT DOCUMENT SECT - V
Wastewater Laboratories" (published by EPA Environmental Monitor-
ing and Support Laboratory, Cincinnati, Ohio, 1976), As part of
the daily quality control program, blanks (including sealed sam-
ples of blank water carried to each sampling site and returned
unopened, as well as samples of blank water used in the field),
standards, and spiked samples were routinely analyzed with actual
samples. As part of the overall program, all analytical instru-
ments (such as balances, spectrophotometers, and recorders) were
routinely maintained and calibrated.
The atomic-absorption spectrophotometer used for metal analysis
was checked to see that it was operating correctly and performing
within expected limits. Appropriate standards were included
after at least every 10 samples, Reagent blanks were also ana-
lyzed for each metal.
WATER USE AND WASTEWATER CHARACTERISTICS
In each of the subcategory supplements, wastewater characteris-
tics corresponding to the subcategories in the nonferrous metals
manufacturing category are presented and discussed. Tables are
presented in Section V of each of the subcategory supplements
which present the sampling program data for raw waste and treated
effluent sampled streams. For those pollutants detected above
analytically quantifiable concentrations in any sample of a given
wastewater stream, the actual analytical data are presented.
Where no data are listed for a specific day of sampling, it
indicates that the wastewater samples for the stream were not
collected.
The statistical analysis of data includes some samples measured
at concentrations considered not quantifiable. The base neu-
trals, acid fraction, and volatile organics are considered not
quantifiable at concentrations equal to or less than 0.010 mg/1.
Below this level, organic analytical results are not quantita-
tively accurate; however, the analyses are useful to indicate the
presence of a particular pollutant. Nonquantifiable results are
designated in the tables with an asterisk (double asterisk for
pesticides).
When calculating averages from the organic sample data, non-
quantifiable results and data reported as not detected (ND) were
assumed to be zero. When calculating averages from metal,
cyanide, conventional and nonconventional sampling data, values
reported as less than a certain value were considered as not
quantifiable, and consequently were assigned a value of zero.
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GENERAL DEVELOPMENT DOCUMENT SECT - V
Table V-l
DISTRIBUTION OF SAMPLED PLANTS IN THE NONFERROUS METALS
MANUFACTURING CATEGORY BY SUBCATEGORY
Number
Subcategory of Plants
Bauxite Refining 2
Primary Aluminum Smelting 7
Secondary Aluminum Smelting 5
Primary Copper Smelting 4
Secondary Copper 5
Primary Lead 3
Secondary Lead 8
Primary Zinc 6
Primary Tungsten 6
Primary Columfaium-Tantalum 4
Secondary Silver 4
Metallurgical Acid Plants*
Primary Antimony -
Primary Beryllium 1
Primary and Secondary Germanium and Gallium 2
Secondary Indium 1
Primary Magnesium** 1
Secondary Mercury -
Primary Molybdenum and Rhenium (includes
Molybdenum Acid Plants 3
Secondary Molybdenum and Vanadium 1
Primary Nickel and Cobalt 1
Secondary Nickel 1
Primary Precious Metals and Mercury 2
Secondary Precious Metals 5
Primary Rare Earth Metals 1
Secondary Tantalum 2
Secondary Tin 5
Primary and Secondary Titanium 3
Secondary Tungsten and Cobalt 2
Secondary Uranium 1
Primary Zirconium and Hafnium 2
TOTAL (!) 84
**The primary magnesium subcategory has been recommended for
exclusion under Paragraph 8 of the Settlement Agreement.
*Acid plant wastewater samples were collected at the primary
copper, lead, and zinc plants listed above.
•Because several plants were sampled for more than one
subcategory, the actual number of plants sampled is less than
the total number of plants sampled for all subcategories.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
SECTION VI
SELECTION OF POLLUTANT PARAMETERS
The Agency has studied nonferrous metals manufacturing waste-
waters to determine the presence or absence of toxic, conven-
tional, and selected nonconventional pollutants. The toxic
pollutants and nonconventional pollutants are subject to BAT
effluent limitations and guidelines. Conventional pollutants are
considered in establishing BPT, BCT, and NSPS limitations.
Sixty five pollutants and classes of pollutants were classified
as toxic by the CWA amendments of 1977. The Agency clarified
this into the list of 129 specific toxic pollutants listed in
Table VI-1 (page 126) for which specific analysis procedures and
standards were available. These 129 toxic pollutants are
sometimes referred to as priority pollutants. Three pollutants
have been deleted from the toxic pollutant list.
Dichlorodifluoromethane and trichlorofluoromethane were deleted
(46 FR 2266, January 8, 1981) followed by the deletion of bis-
(chloromethyl) ether (46 FR 10723, February 4. 1981) The Agency
has concluded that deleting these compounds will not compromise
adequate control over their discharge into the aquatic
environment and that no adverse effects on the aquatic
environment or on human health will occur as a result of deleting
them from the list of toxic pollutants.
Past studies by EPA and others have identified many pollutant
parameters in addition to the toxic pollutants useful in
characterizing industrial wastewaters and in evaluating treatment
process removal efficiencies. For this reason, a number of other
pollutants and pollutant parameters were also studied for the
nonferrous metals manufacturing category.
The conventional pollutants considered in this rulemaking (total
suspended solids, oil and grease, and pH) traditionally have been
studied to characterize industrial wastewaters. These parameters
impact water quality and are especially useful in evaluating the
effectiveness of some wastewater treatment processes. EPA has
defined the criteria for the selection of conventional pollutants
(43 FR 32857 January 11, 1980).
Several nonconventional pollutants were also considered in devel-
oping these regulations. These include aluminum, barium, boron,
cesium, cobalt, gallium, germanium, hafnium, manganese, radium-
226, rhenium, rubidium, uranium, vanadium, zirconium, chemical
oxygen demand (COD), and total organic carbon (TOC). In addi-
tion, calcium, chloride, magnesium, alkalinity-acidity, total
dissolved solids, total phosphorus (as PO4), and sulfate were
measured to provide data to evaluate the cost of chemical pre-
cipitation and sedimentation treatment of certain wastewater
st reams.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Fluoride, ammonia (NH3), and total phenols (4-AAP) were also
identified as pollutants for some of the subcategories. Fluoride
compounds are used in the production of primary aluminum,
columbium-tantalum, and beryllium and secondary uranium and are
present in the raw wastewater of these industries. NH3 is used in
the process or formed during a process step in the primary
aluminum, columbium-tantalum, tungsten, and zirconium
subcategories and in the secondary molybdenum and vanadium,
precious metals, tungsten and cobalt, uranium, aluminum and
silver subcategories. In other subcategories, it has been used
for neutralization of the wastewater.
RATIONALE FOR SELECTION OF POLLUTANT PARAMETERS
In determining which pollutants to regulate, a pollutant that was
never detected, or that was never found above its analytical
quantification level, usually was eliminated from consideration.
The analytical quantification level for a pollutant is the
minimum concentration at which that pollutant can be reliably
measured. Below that concentration, the identification of the
individual compounds is possible, but quantification is
difficult. For the priority pollutants in this study, the
analytical quantification levels are: 0.005 mg/1 for pesticides,
PCB's, chromium, and nickel: 0.010 mg/1 for the remaining organic
priority pollutants and cyanide, arsenic, beryllium, and
selenium: 10 million fibers per liter (10 MFL) for asbestos:
0.020 mg/1 for lead and silver; 0.009 mg/1 for copper; 0.002 mg/1
for cadmium; and 0.0001 mg/1 for mercury.
These detection limits are not the same as published detection
limits for these pollutants by the same analytical methods. The
detection limits used were reported with the analytical data and
hence are the appropriate limits to apply to the data. Detection
limit variation can occur as a result of a number of laboratory-
specific, equipment-specific, and daily operator-specific
factors. These factors can include day-to-day differences in
machine calibration, variation in stock solutions, and variation
in operators.
Because the analytical standard for TCDD was judged to be too
hazardous to be made generally available, samples were never
analyzed for this pollutant. There is no reason to expect that
TCDD would be present in nonferrous metals manufacturing
wastewater s.
Pollutants which we re defected be low concent rat ions considered
achievable by available treatment technology were also eliminated
from further consideration. For the toxic metals, the chemical
precipitation, sedimentation, and filtration technology values,
which are presented in Section VII (Table VII-21 page 248) were
used. For the toxic organic pollutants detected above their
analytical quantification limit, achievable concentrations for
activated carbon technology were used. These concentrations
represent the most stringent treatment options considered for
pollutant removal.
50
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
The pollutant exclusion procedure was applied to the raw waste
data for each subcategory. Detailed specific results are pre-
sented in Section VI of each of the subcategory supplements.
Summary results of selected pollutants for each subcategory are
presented later in this section.
Toxic pollutants remaining after
process were then selected for
lishing specific regulations.
the application of the exclusion
further consideration in estab-
DESCRIPTION OF POLLUTANT PARAMETERS
The following discussion addresses the pollutant parameters
detected above their analytical quantification limit in any
sample of nonferrous metals manufacturing wastewater. The
description of each pollutant provides the following information:
the source of the pollutant; whether it is a naturally occurring
element, processed material, or manufactured compound; general
physical properties and the form of the pollutant; toxic effects
of the pollutant in humans and other animals; and behavior of the
pollutant in a POTW at concentrations that might be expected from
industrial discharges.
Acenaphthene (1). Acenaphthene (1,2-dihydroacenaphthylene, or
1,8-ethylene-naphthalene) is a polynuclear aromatic hydrocarbon
(PAH) with molecular weight of 154 and a formula of Ci2H10*
Acenaphthene occurs in coal tar produced during high temperature
coking of coal. It has been detected in cigarette smoke and
gasoline exhaust condensates.
The pure compound is a white crystalline solid at room tempera-
ture with a melting range of 95°C to 97°C and a boiling range of
278°C to 280°C. Its vapor pressure at room temperature is less
than 0.02 mm Hg. Acenaphthene is slightly soluble in water (100
mg/1), but even more soluble in organic solvents such as ethanol,
toluene, and chloroform. Acenaphthene can be oxidized by oxygen
or ozone in the presence of certain catalysts. It is stable
under laboratory conditions.
Acenaphthene is used as a dye intermediate, in the manufacture of
some plastics, and as an insecticide and fungicide.
So little research has been performed on acenaphthene that its
mammalian and human health effects are virtually unknown. The
water quality criterion of 0.02 mg/1 is recommended to prevent
the adverse effects on humans due to the organoleptic properties
of acenaphthene in water.
No detailed study of acenaphthene behavior in a POTW is avail-
able. However, it has been demonstrated that none of the organic
toxic pollutants studied so far can be broken down by biological
treatment processes as readily as fatty acids, carbohydrates, or
proteins. Many of the toxic pollutants have been investigated,
51
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
at least in laboratory-scale studies, at concentrations higher
than those expected to be contained by most municipal waste-
waters. General observations relating molecular structure to
ease of degradation have been developed for all of the toxic
organic pollutants.
The conclusion reached by study of the limited data is that bio-
logical treatment produces little or no degradation of acenaph-
thene. No evidence is available for drawing conclusions about
its possible toxic or inhibitory effect on POTW operation.
Its water solubility would allow acenaphthene present in the
influent to pass through a POTW into the effluent. The hydrocar-
bon character of this compound makes it sufficiently hydrophobic
that adsorption onto suspended solids and retention in the sludge
may also be a significant route for removal of acenaphthene from
the POTW.
Acenaphthene has been demonstrated to affect the growth of plants
through improper nuclear division and polyploidal chromosome
number. However, it is not expected that land application of
sewage sludge containing acenaphthene at the low concentrations
which are to be expected in a POTW sludge would result in any
adverse effects on animals ingesting plants grown in such soil.
Benzene (4). Benzene (C5H5) is a clear, colorless liquid
obtained mainly from petroleum feedstocks by several different
processes. Some is recovered from light oil obtained from coal
carbonization gases. It boils at 80°C and has a vapor pressure
of 100 mm Hg at 26°C. It is slightly soluble in water (1.8 g/1
at 25°C) and it dissolves in hydrocarbon solvents. Annual U.S.
production is three to four million tons.
Most of the benzene used in the U.S. goes into chemical
manufacture. About half of that is converted to ethylbenzene
which is used to make styrene. Some benzene is used in motor
fuels.
Benzene is narmful to human health according to numerous pub-
lished studies. Most studies relate effects of inhaled benzene
vapors. These effects include nausea, loss of muscle coordina-
tion, and excitement, followed by depression and coma. Death is
usually the result of respiratory or cardiac failure. Two spe-
cific blood disorders are related to benzene exposure. One of
these, acute myelogenous leukemia, represents a carcinogenic
effect of benzene. However, most human exposure data are based
on exposure in occupational settings and benzene carcinogenisis
is not considered to be firmly established.
Oral administration of benzene to laboratory animals produced
leukopenia, a reduction in number of leukocytes in the blood.
Subcutaneous injection of benzene-oil solutions has produced sug-
gestive, but not conclusive, evidence of benzene carcinogenisis.
Benzene demonstrated teratogenic effects in laboratory animals,
52
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
and mutagenic effects in humans and other animals.
For maximum protection of human health from the potential
carcinogenic effects of exposure to benzene through ingestion of
water and contaminated aquatic organisms, the ambient water
concentration is zero. Concentrations of benzene estimated to
result in additional lifetime cancer risk at levels of 10 ,
10" / and 10"5 are 0.00015 mg/1, 0.0015 mg/1, and 0.015 mg/1,
respectively.
Some studies have been reported regarding the behavior of benzene
in a POTW, Biochemical oxidation of benzene under laboratory
conditions, at concentrations of 3 to 10 mg/1, produced 24, 27,
24, and 20 percent degradation in 5, 10, 15, and 20 days,
respectively, using unacclimated seed cultures in fresh water.
Degradation of 58, 67, 76, and 80 percent was produced in the
same time periods using acclimated seed cultures. Other
studies produced similar results. Based on these data and
general conclusions relating molecular structure to biochemical
oxidation, it is expected that biological treatment in a POTW
will remove benzene readily from the water. Other reports
indicate that most benzene entering a POTW is removed to the
sludge and that influent concentrations of lm/1 inhibit sludge
digestion. There is no information about possible effects of
benzene on crops grown in soils amended with sludge containing
benzene.
Carbon Tetrachloride (6). Carbon tetrachloride (CCI4), also
called tetrachloromethane, is a colorless liquid produced primar-
ily by the chlorination of hydrocarbons, particularly methane.
Carbon tetrachloride boils at 77°C and has a vapor pressure of 90
mm Hg at 20°C. It is slightly soluble in water (0.8 gm/1 at
25°C) and soluble in many organic solvents. Approximately one-
third of a million tons is produced annually in the U.S.
Carbon tetrachloride, which was displaced by perchloroethylene as
a dry cleaning agent in the 1930's, is used principally as an
intermediate for production of chlorofluoromethanes for refriger-
ants, aerosols, and blowing agents. It is also used as a grain
fumigant.
Carbon tetrachloride produces a variety of toxic effects in
humans. Ingestion of relatively large quantities - greater than
5 grams - has frequently proved fatal. Symptoms are burning
sensation in the mouth, esophagus, and stomach, followed by
abdominal pains, nausea, diarrhea, dizziness, abnormal pulse, and
coma. When death does not occur immediately, liver and kidney
damage are usually found. Symptoms of chronic poisoning are not
as well defined. General fatigue, headache, and anxiety have
been observed, accompanied by digestive tract and kidney discom-
fort or pain.
Data concerning teratogenicity and mutagenicity of carbon tetra-
chloride are scarce and inconclusive. However, carbon tetrachlo-
ride has been demonstrated to be carcinogenic in laboratory
53
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
animals. The liver was the target organ.
For maximum protection of human health from the potential carcin-
ogenic effects of exposure to carbon tetrachloride through inges-
tion of water and contaminated aquatic organisms, the ambient
water concentration is zero. Concentrations of carbon tetrachlo-
ride estimated to result in additional lifetime cancer risk at
risk levels of 10"' , 10 , and 10 5 are 0.000026 mg/1, 0.00026
mg/1, and 0.0026 mg/1, respectively.
Data on the behavior of carbon tetrachloride in a POTW are not
available. Many of the toxic organic pollutants have been inves-
tigated, at least in laboratory-scale studies, at concentrations
higher than those expected to be found in most municipal waste-
waters . General observations have been developed relating
molecular structure to ease of degradation for all of the toxic
organic pollutants. The conclusion reached by study of the
limited data is that biological treatment produces a moderate
degree of removal of carbon tetrachloride in a POTW. No informa-
tion was found regarding the possible interference of carbon
tetrachloride with treatment processes. Based on the water
solubility of carbon tetrachloride, and the vapor pressure of
this compound, it is expected that some of the undegraded carbon
tetrachloride will pass through to the POTW effluent and some
will be volatilized in aerobic processes.
Chlorobenzene (7). Chlorobenzene (C5H5CI), also called mono-
chlorobenzene is a clear, colorless, liquid manufactured by the
liquid phase chlorination of benzene over a catalyst. It boils
at 132°C and has a vapor pressure of 12.5 mm Hg at 25°C.
It is almost insoluble in water (0.5 g/1 at 30°C), but
dissolves in hydrocarbon solvents. U.S. annual production is
near 150,000 tons.
Principal uses of chlorobenzene are as a solvent and as an inter-
mediate for dyes and pesticides. Formerly it was used as an
intermediate for DDT production, but elimination of production of
that compound reduced annual U.S. production requirements for
chlorobenzene by half.
Data on the threat to human health posed by chlorobenzene are
limited. Laboratory animals, administered large doses of
chlorobenzene subcutaneously, died as a result of central nervous
system depression. At slightly lower dose rates, animals died of
liver or kidney damage. Metabolic disturbances occurred also.
At even lower dose rates of orally administered chlorobenzene
similar effects were observed, but some animals survived longer
than at higher dose rates. No studies have been reported
regarding evaluation of the teratogenic, mutagenic, or
carcinogenic potential of chlorobenzene.
For the prevention of adverse effects due to the organoleptic
properties of chlorobenzene in water the recommended criterion is
0.020 mg/1.
54
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GENERAL DEVELOPMENT DOCUMENT
SECT - VI
Only limited data are available on which to base conclusions
about the behavior of chlorobenzene in a POTW. Laboratory
studies of the biochemical oxidation of chlorobenzene have been
carried out at concentrations greater than those expected to
normally be present in POTW influent. Results showed the extent
of degradation to be 25, 28, and 44 percent after 5, 10, and 20
days, respectively. In another, similar study using a phenol-
adapted culture, 4 percent degradation was observed after 3 hours
with a solution containing 80 mg/1. On the basis of these
results and general conclusions about the relationship of molec-
ular structure to biochemical oxidation, it is concluded that
chlorobenzene remaining intact is expected to volatilize from the
POTW in aeration processes. The estimated half-life of chloro-
benzene in water based on water solubility, vapor pressure and
molecular weight is 5.8 hours.
1,2,4-Trichlorobenzene (8). 1,2,4-Trichlorobenzene (C6H3C13),
1,2,4-TCB) is a liquid at room temperature, solidifying to a
crystalline solid at 17°C and boiling at 214°C. It is produced
by liquid phase chlorination of benzene in the presence of a
catalyst. Its vapor pressure is 4 mm Hg at 25°C. 1,2,4-TCB is
insoluble in water and soluble in organic solvents. Annual U.S.
production is in the range of 15,000 tons. 1,2,4-TCB is used in
limited quantities as a solvent and as a dye carrier in the
textile industry. It is also used as a heat transfer medium and
as a transfer fluid. The compound can be selectively chlorinated
to 1,2,4,5-tetrachlorobenzene using iodine plus antimony
trichloride as catalyst.
No reports were available regarding the toxic effects of 1,2,4-
TCB on humans. Limited data from studies of effects in
laboratory animals fed 1,2,4-TCB indicate depression of activity
at low doses and predeath extension convulsions at lethal doses.
Metabolic disturbances and liver changes were also observed.
Studies for the purpose of determining teratogenic or mutagenic
properties of 1,2,4-TCB have not been conducted. No studies have
been made of carcinogenic behavior of 1,2,4-TCB administered
orally.
For the prevention of adverse effects due to the organoleptic
properties of 1,2,4-trichlorobenzene in water, the water quality
criterion is 0.013 mg/1.
Data on the behavior of 1,2,4-TCB in POTW are not available.
However, this compound has been investigated in a laboratory
scale study of biochemical oxidation at concentrations higher
than those expected to be contained by most municipal waste-
waters. Degradations of 0, 87, and 100 percent were observed
after 5, 10, and 20 days, respectively. Using this observation
and general observations relating molecular structure to ease of
degradation for all of the organic priority pollutants, the
conclusion was reached that biological treatment produces a high
degree of removal in POTW.
Hexachlorobenzene J_9 ) • Hexachlorobenzene (C5H5) is a non-
55
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
flammable crystalline substance which is virtually insoluble in
water. However, it is soluble in benzene, chloroform, and ether.
Hexachlorobenzene (HCB) has a density of 2,044 g/ml. It melts at
231°C and boils at 323 to 326°C. Commercial production of HCB in
the U.S. was discontinued in 1976, though it is still generated
as a by-product of other chemical operations. In 1972, an
estimated 2,425 tons of HCB were produced in this way.
Hexachlorobenzene is used as a fungicide to control fungal
diseases in cereal grains. The main agricultural use of HCB is
on wheat seed intended solely for planting. HCB has been used
as an impurity in other pesticides. It is used in industry as a
piasticizer for polyvinyl chloride as well as a flame retardant.
HCB is also used as a starting material for the production of
pentachlorophenol which is marketed as a wood preservative.
Hexachlorobenzene can be harmful to human health as was seen in
Turkey from 1955 to 1959. Wheat that had been treated with HCB
in preparation for planting was consumed as food. Those people
affected by HCB developed cutanea tarda porphyria, the symptoms
of which included blistering and epidermolysis of the exposed
parts of the body, particularly the face and the hands. These
symptoms disappeared after consumption of HCB contaminated bread
was discontinued. However, the HCB which was stored in body fat
contaminated maternal milk. As a result of this, at least 95
percent of the infants feeding on this milk died. The fact that
HCB remains stored in body fat after exposure has ended presents
an additional problem. Weight loss may result in a dramatic
redistribution of HCB contained in fatty tissue. If the stored
levels of HCB are high, adverse effects might ensue.
Limited testing suggests that hexachlorobenzene is not terato-
genic or mutagenic. However, two animal studies have been con-
ducted which indicate that HCB is a carcinogen. HCB appears to
have multipotential carcinogenic activity; the incidence of hepa-
tomas, haemangioendotheliomas and thyroid adenomas was signifi-
cantly increased in animals exposed to HCB by comparison to con-
trol animals.
For maximum protection of human health from the potential carcin-
ogenic effects of exposure to hexachlorobenzene through ingestion
of water and contaminated aquatic organisms, the ambient water
concentration is zero. Concentrations of HCB estimated to result
in additional lifetime cancer risk at levels of 10 , 10~6, and
10-5 are 7.2 x 10 8 mg/1, 7.2 x 10~7 mg/1, and 7.2 x 10~6 mg/1,
respectively. If contaminated aquatic organisms alone are
consumed, excluding the consumption of water, the water
concentration should be less than 7.4 x 10 6 mg/1 to keep the
increased lifetime cancer risk below 10~5. Available data show
that adverse effects on aquatic life occur at concentrations
higher than those cited for human health risks.
No detailed study of hexachlorobenzene behavior in POTW is
available. However, general observations relating molecular
56
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
structure to ease of degradation have been developed for all of
the organic priority pollutants. The conclusion reached by study
of the limited data is that biological treatment produces little
or no degradation of hexachlorobenzene. No evidence is available
for drawing conclusions regarding its possible toxic or
inhibitory effect on POTW operations.
1,2-Dichiproethane (10) . 1,2-Dichloroethane is a halogenated
aliphatic used in the production of tetraethyl lead and vinyl
chloride, as an industrial solvent, and as an intermediate in the
production of other organochlorine compounds. Some chlorinated
ethanes have been found in drinking waters, natural waters,
aquatic organisms, and foodstuffs. Research indicates that they
may have mutagenic and carcinogenic properties.
1,1,1-Trichloroethane (11). 1,1,1-Trichloroethane is one of the
two possible trichlorethanes. It is manufactured by hydrochlori-
nating vinyl chloride to 1,1-dichloroethane which is then chlori-
nated to the desired product. 1,1,1-Trichloroethane is a liquid
at room temperature with a vapor pressure of 96 mm Hg at 20°C and
a boiling point of 74°C. Its formula is CCI3CH3 It is slightly
soluble in water (0,48 g/1) and is very soluble in organic
solvents. U.S. annual production is greater than one-third of a
million tons.
1,1,1-Trichloroethane is used as an industrial solvent and
degreasing agent.
Most human toxicity data for 1,1,1-trichloroethane relates to
inhalation and dermal exposure routes. Limited data are avail-
able for determining toxicity of ingested 1,1,1-trichloroethane,
and those data are all for the compound itself, not solutions in
water. No data are available regarding its toxicity to fish and
aquatic organisms. For the protection of human health from the
toxic properties of 1,1,1-trichloroethane ingested through the
consumption of water and fish, the ambient water criterion is
15.7 mg/1. The criterion is based on bioassays for possible
carcinogenicity.
No detailed study of 1,1,1-trichloroethane behavior in a POTW is
available. However, it has been demonstrated that none of the
toxic organic pollutants of this type can be broken down by bio-
logical treatment processes as readily as fatty acids, carbohy-
drates, or proteins.
Biochemical oxidation of many of the toxic organic pollutants has
been investigated, at least in laboratory-scale studies, at con-
centrations higher than commonly expected in municipal waste-
water. General observations relating molecular structure to ease
of degradation have been developed for all of these pollutants.
The conclusion reached by study of the limited data is that
biological treatment produces a moderate degree of degradation of
1,1,1 -tr ichloroethane. No evidence is available for drawing con-
clusions about its possible toxic or inhibitory effect on POTW
operation. However, for degradation to occur, a fairly constant
57
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
input of the compound would be necessary.
Its water solubility would allow 1,1,1-trichloroethane, present
in the influent and not biodegradable, to pass through a POTW
into the effluent. One factor which has received some attention,
but no detailed study, is the volatilization of the lower molecu-
lar weight organics from a POTW. If 1,1,1-trichloroethane is not
biodegraded, it will volatilize during aeration processes in the
POTW.
Hexachloroethane (12) . Hexachloroethane (CCI3CCI3), also called
perchloroethane is a white crystalline solid with a camphor-like
odor. It is manufactured from tetrachloroethylene, and is a
minor product in many industrial chlorination processes designed
to produce lower chlorinated hydrocarbons. Hexachloroethane
sublimes at 185°C and has a vapor pressure of about 0.2 mm Hg at
20°C. It is insoluble in water (50 mg/1 at 22°C) and soluble in
some organic solvents
Hexachloroethane can be used in lubricants designed to withstand
extreme pressure. It is used as a plasticizer for cellulose
esters, and as a pesticide. It is also used as a retarding agent
in fermentation, as an accelerator in the rubber industry, and in
pyrotechnic and smoke devices.
Hexachloroethane is considered to be toxic to humans by ingestion
and inhalation. In laboratory animals liver and kidney damage
have been observed. Symptoms in humans exposed to
hexachloroethane vapor include severe eye irritation and vision
impairment. Based on studies on laboratory animals,
hexachloroethane is considered to be carcinogenic.
For the maximum protection to human health from the potential
carcinogenic effects of exposure to hexachloroethane through
ingestion of water and contaminated aquatic organisms, the
ambient water concentration is zero. Concentrations of hexa-
chloroethane estimated to result in additional lifetime cancer
risks at levels of 1Q-7, 10" , and 1Q-5 are 0.000059 mg/1,
0.00059 mg/1, and 0.0059 mg/1. respectively.
Data on the behavior of hexachloroethane in POTW are not
available. Many of the organic priority pollutants have been
investigated at least in laboratory scale studies, at
concentrations higher than those expected to be contained by most
municipal wastewaters. General observations have been developed
relating molecular structure to ease of degradation for all of
the organic priority pollutants. The conclusion reached by study
of the limited data is that biological treatment produces little
or no removal of hexachloroethane in POTW. The lack of water
solubility and the expected affinity of hexachloroethane for
solid particles lead to the expectation that this compound will
be removed to the sludge in POTW. No information was found
regarding possible uptake of hexachloroethane by plants grown on
soils amended with hexachloroethane-bearing sludge.
58
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
1,1-Dichloroethane (13). 1,1-Dichloroethane, C2H4CI2 t also
called ethylidene dichlor ide and ethylidene chlor rde, is a
colorless liquid manufactured by reacting hydrogen chloride with
vinyl chloride in 1,1-dichloroethane solution in the presence of
a catalyst. However, it is reportedly not manufactured
commercially in the U.S. 1,1-Dichloroethane boils at 57°C and
has a vapor pressure of 182 mm Hg at 20°C. It is slightly
soluble in water (5.5 g/1 at 20°C) and very soluble in organic
solvents.
1,1-Dichloroethane is used as an extractant for heat-sensitive
substances and as a solvent Cor rubber and silicone grease.
1,1-Dichloroethane is less toxic than its isomer (1,2-dichloro-
ethane), but its use as an anaesthetic has been discontinued
because of marked excitation of the heart. It causes central
nervous system depression in humans. There are insufficient data
to derive water quality criteria for 1,1-dichloroethane.
Data on the behavior of 1,1-dichloroethane in a POTW are not
available. Many of the toxic organic pollutants have been
investigated, at least in laboratory-scale studies, at concen-
trations higher than those expected to be contained by most
municipal wastewaters. General observations have been developed
relating molecular structure to ease of degradation for all of
the toxic organic pollutants. The conclusion reached by study of
the limited data is that biological treatment produces only a
moderate removal of 1,1-dichloroethane in a POTW by degradation.
The high vapor pressure of 1,1-dichloroethane is expected to
result in volatilization of some of the compound from aerobic
processes in a POTW. Its water solubility will result in some of
the 1,1-dichloroethane which enters the POTW leaving in the
effluent from the POTW.
1,1,2-Trichloroethane (14). 1,1,2-Trichloroethane is one of the
two possible trichloroethanes and is sometimes called ethane tri-
chloride or vinyl trichloride. It is used as a solvent for fats,
oils, waxes, and resins, in the manufacture of 1,1-dichloro-
ethylene, and as an intermediate in organic synthesis.
1,1,2-Trichloroethane is a clear, colorless liquid at room tem-
perature with a vapor pressure of 16.7 nun Hg at 20°C, and a boil-
ing point of 113°C. it is insoluble in water and very soluble in
organic solvents. The formula is CHCI2CH2CI.
Human toxicity data for 1,1,2-trichloroethane do not appear in
the literature. The compound does produce liver and kidney dam-
age in laboratory animals after intraperitoneal administration.
No literature data were found concerning teratogenicity or muta-
genicity of 1,1,2-trichloroethane. However, mice treated with
1,1,2-trichloroethane shewed increased incidence of hepatocellu-
lar carcinoma. Although bioconcentration factors are not avail-
able for 1,1,2-trichloroethane in fish and other freshwater
aquatic organisms, it is concluded on the basis of octanol-water
59
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
partition coefficients that bioconcentration does occur.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to 1,1,2-trichloroethane through
ingestion of water and contaminated aquatic organisms, the
ambient water concentration is zero. Concentrations of this
compound estimated to result in additional lifetime cancer risks
at risk levels of 10"', 10" , and 10~5 are 0.00006 mg/1, 0.0006
mg/1, and 0.006 mg/1, respectively. If contaminated aquatic
organisms alone are consumed, excluding the consumption of water,
the water concentration should be less than 0.418 mg/1 to keep
the increased lifetime cancer risk below 1Q~5. Available data
show that adverse effects on aquatic life occur at concentrations
higher than those cited for human health risks.
No detailed study of 1,1,2-trichloroethane behavior in a POTW is
available. However, it is reported that small amounts are formed
by chlorination processes and that this compound persists in the
environment (greater than two years) and it is not biologically
degraded. This information is not completely consistent with the
conclusions based on laboratory-scale biochemical oxidation
studies and relating molecular structure to ease degradation.
That study concluded that biological treatment in a POTW will
produce moderate removal of 1,1,2-trichloroethane,
The lack of water solubility and the relatively high vapor
pressure may lead to removal of this compound from a POTW by
volatilization.
2,4,6-Trichlorophenol (21). 2,4,6-Trichlorophenol (6H2CI3OH,
abbreviated here to 2,4,6-TCP) is a colorless, crystalline solid
at room temperature. It is prepared by the direct chlorination
of phenol. 2,4,6-TCP melts at 68°C and is slightly soluble in
water (0.8 gm/1 at 25°C). This phenol does not produce a color
with 4-aminoantipyrene, and therefore does not contribute to the
nonconventional pollutant parameter "Total Phenols." No data
were found on production volumes.
2,4,6-TCP is used as a fungicide, bactericide, glue and wood
preservative, and for antimildew treatment. It is also used for
the manufacture of 2,3,4,6-tetrachlorophenol and
pentachlorophenol.
No data were found on human toxicity effects of 2,4,6-TCP.
Reports of studies with laboratory animals indicate that 2,4,6-
TCP produced convulsions when injected interperitoneally. Body
temperature was elevated also. The compound also produced
inhibition of ATP production in isolated rat liver mitochondria,
increased mutation rates in one strain of bacteria, and produced
a genetic change in rats. No studies on teratogenicity were
found. Results of a test for carcinogenicity were inconclusive.
For the prevention of adverse effects due to the organoleptic
properties of 2,4,6-1 r ichlorophenol in water, the water quality
criterion is 0.100 mg/1.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Although no data were found regarding the behavior of 2,4,6-TCP
in a POTW, studies of the biochemical oxidation of the compound
have been made at laboratory scale at concentrations higher than
those normally expected in municipal wastewaters. Biochemical
oxidation to 2,4,6-TCP at 100 mg/1 produced 23 percent
degradation using a phenol-adapted acclimated seed culture.
Based on these results, biological treatment in a POTW is
expected to produce a moderate degree of degradation. Another
study indicates that 2,4,6-TCP may be produced in a POTW by
chlorination of phenol during normal chlorination treatment.
Para-chloro-meta-cresol (22). Para-chloro-meta-cresol
(CIC7H6OH)) is thought to be a 4-chloro-3-methyl-phenol (4-
chloro-meta-cresol, or 2-chloro-5-hydroxy-toluene), but is also
used by some authorities to refer to 6-chloro-3-methyl-phenol (6-
chloro-meta-cresol, or 4-chloro-3-hydroxy-toluene), depending on
whether the chlorine is considered to be para to the methyl or to
the hydroxy group. it is assumed for the purposes of this
document that the subject compound is 2-chloro-5-hydroxy-toluene.
This compound is a colorless crystalline solid melting at 66 to
68°C. It is slightly soluble in water (3.8 gm/1) and soluble in
organic solvents. This phenol reacts with p-aminoantipyrene to
give a colored product and therefore contributes to the
nonconventional pollutant parameter designated "Total Phenols."
No information on manufacturing methods or volumes produced was
found.
Para-chloro-meta cresol (abbreviated here as PCMC) is marketed as
a microbiocide, and was proposed as an antiseptic and
disinfectant more than 40 years ago. It is used in glues, gums,
paints, inks, textiles, and leather goods. PCMC was found in
raw wastewaters from the die casting quench operation from one
subcategory of foundry operations.
Although no human toxicity data are available for PCMC, studies
on laboratory animals have demonstrated that this compound is
toxic when administered subcutaneously and intravenously. Death
was preceded by severe muscle tremors. At high dosages, kidney
damage occurred. On the other hand, an unspecified isomer of
chlorocresol, presumed to be PCMC, is used at a concentration of
0.15 percent to preserve mucous heparin, a natural product
administered intravenously as an anticoagulant. The report does
not indicate the total amount of PCMC typically received. No
information was found regarding possible teratogenicity, or
carcinogenicity of PCMC.
Two reports indicate that PCMC undergoes degradation in
biochemical oxidation treatments carried out at concentrations
higher than are expected to be encountered in POTW influents.
One study showed 50 percent degradation in 3.5 hours when a
phenol-adapted acclimated seed culture was used with a solution
of 60 mg/1 PCMC. The other study showed 100 percent degradation
of a 20 mg/1 solution of PCMC in two weeks in an aerobic
activated sludge test system. No degradation of PCMC occurred
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
under anaerobic conditions.
Chloroform (23). Chloroform, CHCI3, also called
trichloromethane, is a colorless liquid manufactured commercially
by chlorination of methane. Careful control of conditions
maximizes chloroform production, but other products must be
separated. Chloroform boils at 61°C and has a vapor pressure of
200 mm Hg at 25°C. It is slightly soluble in water (8.22 g/1 at
20°C and readily soluble in organic solvents.
Chloroform is used as a solvent and to manufacture refrigerants,
pharmaceuticals, plastics, and anesthetics. It is seldom used as
an anesthetic.
Toxic effects of chloroform on humans include central nervous
system depression, gastrointestinal irritation, liver and kidney
damage, and possible cardiac sensitization to adrenalin. Carcin-
ogenicity has been demonstrated for chloroform on laboratory
animals.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to chloroform through ingestion
of water and contaminated aquatic organisms, the ambient water
concentration is zero. Concentrations of chloroform estimated to
result in additional lifetime cancer risks at the levels of 10"',
10"6, and 1Q"5 were 0.000021 mg/1, 0.00021 mg/1, and 0.0021 mg/1,
respectively.
No data are available regarding the behavior of chloroform in a
POTW. However, the biochemical oxidation of this compound was
studied in one laboratory-scale study at concentrations higher
than those expected to be contained by most municipal waste-
waters. After 5, 10, and 20 days no degradation of chloroform
was observed. The conclusion reached is that biological treat-
ment produces little or no removal by degradation of chloroform
in a POTW.
The high vapor pressure of chloroform is expected to result in
volatilization of the compound from aerobic treatment steps in a
POTW. Remaining chloroform is expected to pass through into the
POTW effluent.
2-Chlorophenol (24). 2-Chlorophenol (CIC5H4OH), also called
ortho-chlorophenol, is a colorless liquid at room temperature,
manufactured by direct chlorination of phenol followed by distil-
lation to separate it from the other principal product, 4-chloro-
phenol. 2-Chlorophenol solidifies below 7°C and boils at 176°C.
It is soluble in water (28.5 gm/1 at 20°C) and soluble in several
types of organic solvents. This phenol gives a strong color with
4-aminoantipyrene and therefore contributes to the
nonconventional pollutant parameter "Total Phenols." Production
statistics could not be found. 2-Chlorophenol is used almost
exclusively as a chemical intermediate in the production of
pesticides and dyes. Production of some phenolic resins uses 2-
chlorophenol.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Very few data are available on which to determine the toxic
effects of 2-chlorophenol on humans. The compound is more toxic
to laboratory mammals when administered orally than when
administered subcutaneously or intravenously. This effect is
attributed to the fact that the compound is almost completely in
the unionized state at the low pH of the stomach and hence is
more readily absorbed into the body. Initial symptoms are
restlessness and increased respiration rate, followed by motor
weakness and convulsions induced by noise or touch. Coma
follows. Following lethal doses, kidney, liver, and intestinal
damage were observed. No studies were found which addressed the
teratogenicity or mutagenicity of 2-chlorophenol. Studies of 2-
chlorophenol as a promoter of carcinogenic activity of other
carcinogens were conducted by dermal application. Results do not
bear a determinable relationship to results of oral
administration studies.
For the prevention of adverse effects due to the organoleptic
properties of 2-chlorophenol in water, the criterion is 0.0003
mg/1.
Data on the behavior of 2-chlorophenol in a POTW are not
available. However, laboratory-scale studies have been conducted
at concentrations higher than those expected to be found in
municipal wastewaters. At 1 mg/1 of 2-chlorophenol, an
acclimated culture produced 100 percent degradation by
biochemical oxidation after 15 days. Another study showed 45,
70, and 79 percent degradation by biochemical oxidation after 5,
10, and 20 days, respectively. The conclusion reached by the
study of these limited data, and general observations on all
toxic organic pollutants relating molecular structure to ease of
biochemcial oxidation, is that 2-chlorophenol is removed to a
high degree or completely by biological treatment in a POTW.
Undegraded 2-chlorophenol is expected to pass through a POTW into
the effluent because of the water solubility. Some 2-
chlorophenol is also expected to be generated by chlorination
treatments of POTW effluents containing phenol.
1,1-Dichloroethylene (29 ) . 1,1-Dichloroethylene (1,1-DCE), also
called vinylidene chloride, is a clear colorless liquid
manufactured by dehydrochlorination of 1,1,2-trichloroethane.
1,1-DCE has the formula CCI2CH2• It has a boiling point of 32°C,
and a vapor pressure of 591 mm Hg at 25°C. 1,1-DCE is slightly
solu-ble in water (2.5 mg/1) and is soluble in many organic
solvents. U.S. production is in the range of hundreds of
thousands of tons annually.
1,1-DCE is used as a chemical intermediate and for copolymer
coatings or films. It may enter the wastewater of an industrial
facility as the result of decomposition of 1,1,1-trichloro-
ethylene used in degreasing operations, or by migration from
vinylidene chloride copolymers exposed to the process water.
Human toxicity of 1,1-DCE has not been demonstrated; however, it
is a suspected human carcinogen. Mammalian toxicity studies have
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
focused on the liver and kidney damage produced by 1,1-DCE.
Various changes occur in those organs in rats and mice ingesting
1,1-DCE.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to 1,1-dichloroethylene through
ingestion of water and contaminated aquatic organisms, the
ambient water concentration is zero. The concentration of 1,1-
DCE estimated to result in an additional lifetime cancer risk of
1 in 100,000 is 0.0013 mg/1.
Under laboratory conditions, dichloroethylenes have been shown to
be toxic to fish. The primary effect of acute toxicity of the
dichloroethylenes is depression of the central nervous system.
The octanol-water partition coefficient of 1,1-DCE indicates it
should not accumulate significantly in animals.
The behavior of 1,1-DCE in a POTW has not been studied. However,
its very high vapor pressure is expected to result in release of
significant percentages of this material to the atmosphere in any
treatment involving aeration. Degradation of dichloroethylene in
air is reported to occur, with a half-life of eight weeks.
Biochemical oxidation of many of the toxic organic pollutants has
been investigated in laboratory-scale studies at concentrations
higher than would normally be expected in municipal wastewaters.
General observations relating molecular structure to ease of
degradation have been developed for all of these pollutants. The
conclusion reached by study to the limited data is that
biological treatment produces little or no degradation of 1,1-
dichloroethylene. No evidence is available for drawing
conclusions about the possible toxic or inhibitory effect of 1,1-
DCE on POTW operation. Because of water solubility, 1,1-DCE
which is not volatilized or degraded is expected to pass through
a POTW. Very little 1,1-DCE is expected to be found in sludge
from a POTW.
1, 2-trans-Dichloroethylene ( 30 ) . 1, 2-Dichloroe_thylene (1,2-
trans-DCE) is a clear, colorless liquid with the formula
CHC1CHC1. 1,2-trans-DCE is produced in mixture with the cis-
isomer by chlorination of acetylene. The cis-isomer has
distinctly different physical properties. Industrially, the
mixture is used rather than the separate isomers. 1,2-trans-DCE
has a boiling point of 48°C, and a vapor pressure of 234 mm Hg at
2 5°C.
The principal use of 1,2-dichloroethylene (mixed isomers) is to
produce vinyl chloride. It is used as a lead scavenger in
gasoline, general solvent, and for synthesis of various other
organic chemicals. When it is used as a solvent, 1,2-trans-DCE
can enter wastewater streams.
Although 1,2-t rans-DCE is thought to produce fatty degeneration
of mammalian liver, there are insufficient data on which to base
any ambient water criterion.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
In the reported toxicity test of 1,2-trans-DCE on aquatic life,
the compound appeared to be about half as toxic as the other
dichloroethylene (1,1-DCE) on the toxic pollutants list.
The behavior of 1,2-trans-DCE in a POTW has not been studied.
However, its high vapor pressure is expected to result in release
of a significant percentage of this compound to the atmosphere in
any treatment involving aeration. Degradation of the dichloro-
ethylenes in air is reported to occur, with a half-life of eight
weeks.
Biochemical oxidation of many of the toxic organic pollutants has
been investigated in laboratory-scale studies at concentrations
higher than would normally be expected in municipal wastewaters.
General observations relating molecular structure to ease of
degradation have been developed for all of these pollutants. The
conclusion reached by the study of the limited data is that
biochemical oxidation produces little or no degradation of 1,2-
trans-dichloroethylene. No evidence is available for drawing
conclusions about the possible toxic or inhibitory effect of 1,2-
trans-dichloroethylene on POTW operation. It is expected that
its low molecular weight and degree of water solubility will
result in 1,2-trans-DCE passing through a POTW to the effluent if
it is not degraded or volatilized. Very little 1,2-trans-DCE is
expected to be found in sludge from a POTW.
2,4-Dichlorophenol (31). 2,4-Dichlorophenol, a white, low melt-
ing solid, melts at 45°C. it is soluble in alcohol and carbon
tetrachloride and slightly soluble in water. This compound is
moderately toxic by ingestion and is a strong irritant to tissue.
2,4-Dimethylphenol (34). 2,4-Dimethylphenol (2,4-DMP), also
called 2,4-xylenol, is a colorless, crystalline solid at room
temperature (25°C), but melts at 27°C to 28°C. 2,4-DMP is
slightly soluble in water and, as a weak acid, is soluble in
alkaline solutions. Its vapor pressure is less than 1 mm Hg at
room temperature.
2,4-DMP (CqHiqO) is a natural product, occurring in coal and
petroleum sources. It is used commercially as an intermediate
for manufacture of pesticides, dye stuffs, plastics and resins,
and surfactants. It is found in the water runoff from asphalt
surfaces. It can find its way into the wastewater of a
manufacturing plant from any of several adventitious sources.
Analytical procedures specific to this compound are used for its
identification and quantification in wastewaters. This compound
does not contribute to "Total Phenols" determined by the 4-
aminoantipyrene method.
Three met'nylphenol isomers (cresols) and six dimethylphenol
isomers (xylenols) generally occur together in natural products,
industrial processes, commercial products, and phenolic wastes.
Therefore. data are not available for human exposure to 2,4-DMP
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
alone. In addition to this, most mammalian tests for toxicity of
individual dimethylphenol isomers have been conducted with
isomers other than 2,4-DMP,
In general, the mixtures of phenol, methylphenols, and
diraethylphenols contain compounds which produced acute poisoning
in laboratory animals. Symptoms were difficult breathing, rapid
muscular spasms, disturbance of motor coordination, and
asymmetrical body position. In a 1977 National Academy of
Science publication the conclusion was reached that, "In view of
the relative paucity of data on the mutagenicity,
carcinogenicity, teratogenicity, and long term oral toxicity of
2,4-dimethylphenol, estimates of the effects of chronic oral
exposure at low levels cannot be made with any confidence." No
ambient water quality criterion can be set at this time. In
order to protect public health, exposure to this compound should
be minimized as soon as possible.
Toxicity data for fish and freshwater aquatic life are limited;
however, in reported studies of 2,4-dimethylphenol at concen-
trations as high as 2 mg/1 no adverse effects were observed.
The behavior of 2,4-DMP in a POTW has not been studied. As a
weak acid, its behavior may be somewhat dependent on the pH of
the influent to the POTW. However, over the normal limited range
to POTW pH, little effect of pH would be expected.
Biological degradability of 2,4-DMP as determined in one study,
showed 94.5 percent removal based on chemical oxygen demand
(COD). Thus, substantial removal is expected for this compound.
Another study determined that persistence of 2,4-DMP in the
environment is low, and thus any of the compound which remained
in the sludge or passed through the POTW into the effluent
would be degraded within moderate length of time (estimated as
two months in the report).
2,4-Dinitrotoluene (35) 2,4-Dini trotoluene ((NO2)2C6K3CH3), a
yellow crystalline compound, is manufactured as a co-product with
the 2,6-isomer by nitration of nitrotoluene. It melts at 71°C.
2,4-Dinitrotoluene is insoluble in water (0.27 g/1 at 22°C) and
soluble in a number of organic solvents. Production data for the
2,4-isomer alone are not available. The 2,4- and 2,6-isomers are
manufactured in an 80:20 or 65:35 ratio, depending on the process
used. Annual U.S. commercial production is about 150 thousand
tons of the two isomers. Unspecified amounts are Produced by the
U.S. government and further nitrated to trinitrotoluene (TNT) for
military use. The major use of the dinitrotoluene mixture is for
production of toluene diisocyanate used to make polyurethanes.
Another use is in production of dyestuffs.
The toxic effect of 2,4-dinitrotoluene in humans is primarily
methemoglobinemia (a blood condition hindering oxygen transport
by the blood). Symptoms depend on severity of the disease. but
include cyanosis, dizziness, pain in joints, headache, and loss
of appetite in workers inhaling the compound. Laboratory animals
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
fed oral doses of 2,4-dinitrotoluene exhibited many of the same
symptoms. Aside from the effects in red blood cells, effects are
observed in the nervous system and testes.
Chronic exposure to 2,4-dinitrotoluene may produce liver damage
and reversible anemia. No data were found on teratogenicity of
this compound. Mutagenic data are limited and are regarded as
confusing. Data resulting from studies of carcinogenicity of
2,4-dinitrotoluene point to a need for further testing for this
property.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to 2.4-dinitrotoluene through
ingestion of water and contaminated aquatic organisms, the
ambient water concentration is zero. Concentrations of 2,4-
dinitrotoluene estimated toresult in additional lifetime cancer
risk at risk levels of 10" , 10 and 10 5 are 0.00074 mg/1,
0.074 mg/1, and 0.740 mg/1, respectively.
Data on the behavior of 2,4-dinitrotoluene in a POTW are not
available. However, biochemical oxidation of 2,4-dinitrophenol
was investigated on a laboratory scale. At 100 mg/1 of 2,4-
dinitrotoluene, a concentration considerably higher than expected
in municipal wastewaters, biochemical oxidation by an acclimated,
phenol-adapted seed culture produced 52 percent degradation in
three hours. Based on this limited information and general
observations relating molecular structure to ease of degradation
for all the toxic organic pollutants, it was concluded that
biological treatment in a POTW removes 2,4-dinitrotoluene to a
high degree or completely. No information is available regarding
possible interference by 2,4-dinitrotoluene in POTW treatment
processes, or on the possible detrimental effect on sludge used
to amend soils in which food crops are grown.
Ethylbenzene (38). Ethylbenzene (CgHig) is a colorless,
flammable liquid manufactured commercially from benzene and
ethylene. Approximately half of the benzene used in the U.S.
goes into the manufacture of more than three million tons of
ethylbenzene annually. Ethylbenzene boils at 136°C and has a
vapor pressure of 7 mm Hg at 20°C. It is slightly soluble in
water (0.14 g/1 at 15°C) and is very soluble in organic solvents.
About 98 percent of the ethylbenzene produced in the U.S. goes
into the production of styrene, much of which is used in the
plastics and synthetic rubber industries. Ethylbenzene is a
constituent of xylene mixtures used as diluents in the paint
industry, agricultural insecticide sprays, and gasoline blends.
Although humans are exposed to ethylbenzene from a variety of
sources in the environment, little information on effects of
ethylbenzene in man or animals is available. Inhalation can
irritate eyes, affect the respiratory tract, or cause vertigo. In
laboratory animals, ethylbenzene exhibited low toxicity. There
are no data available on teratogenicity, mutagenicity, or car-
cinogenicity of ethylbenzene.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Criteria are based on data derived from inhalation exposure
limits. For the protection of human health from the toxic
properties of ethylbenzene ingested through water and
contaminated aquatic organisms, the ambient water quality
criterion is 1.1 mg/1.
The behavior of ethylbenzene in a POTW has not been studied in
detail. Laboratory-scale studies of the biochemical oxidation of
ethylbenzene at concentrations greater than would normally be
found in municipal wastewaters have demonstrated varying degrees
of degradation. In one study with phenol-acclimated seed
cultures, 27 percent degradation was observed in a half day at
250 mg/1 ethylbenzene. Another study at unspecified conditions
showed 32, 38, and 45 percent degradation after 5, 10, and 20
days, respectively. Based on these results and general
observations relating molecular structure of degradation, it is
concluded that biological treatment produces only moderate
removal of ethylbenzene in a POTW by degradation.
Other studies suggest that most of the ethybenzene entering a
POTW is removed from the aqueous stream to the sludge. The
ethylbenzene contained in the sludge removed from the POTW may
volatilize.
Fluoranthene (39). Fluoranthene (1,2-benzacenaphthene) is one of
the compounds called polynuclear aromatic hydrocarbons (PAH). A
pale yellow solid at room temperature, it melts at 111°C and has
a negligible vapor pressure at 25°C. Water solubility is low
(0.2 mg/1). Its molecular formula is CigHio- Fluoranthene, along
with many other PAHs, is found throughout the environment. It is
produced by pyrolytic processing of organic raw materials, such
as coal and petroleum, at high temperature (coking processes).
It occurs naturally as a product of plant biosynthesis.
Cigarette smoke contains fluoranthene. Although it is not used as
the pure compound in industry, it has been found at relatively
higher concentrations (0.002 mg/1) than most other PAH's in at
least one industrial effluent. Furthermore, in a 1977 EPA survey
to determine levels of PAH in U.S. drinking water supplies, none
of the 110 samples analyzed showed any PAH other than
fluoranthene.
Experiments with laboratory animals indicate that fluoranthene
presents a relatively low degree of toxic potential from acute
exposure, including oral administration. Where death occurred,
no information was reported concerning target organs or specific
cause of death.
There is no epidemiological evidence to prove that PAH in
general, and fluoranthene, in particular, present in drinking
water are related to the development of cancer. The only studies
directed toward determining carcinogenicity of fluoranthene have
been skin tests on laboratory animals. Results of these tests
show that fluoranthene has no activity as a complete carcinogen
(i.e., an agent which produces cancer when applied by itself),
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
but exhibits significant cocarcinogenicity (i.e., in combination
with a carcinogen, it increases the carcinogenic activity).
Based on the limited animal study data, and following an
established procedure, the ambient water quality criterion for
fluoranthene alone (not in combination with other PAH) is
determined to be 200 mg/1 for the protection of human health from
its toxic properties.
There are no data on the chronic effects of fluoranthene on
freshwater organisms. One saltwater invertebrate shows chronic
toxicity at concentrations below 0.016 mg/1. For some fresh-
water fish species the concentrations producing acute toxicity
are substantially higher, but data are very limited.
Results of studies of the behavior of fluoranthene in
conventional sewage treatment processes found in a POTW have been
published. Removal of fluoranthene during primary sedimentation
was found to be 62 to 66 percent (from an initial value of
0.00323 to 0.04435 mg/ to a final value of 0.00122 to 0.0146
mg/1), and the removal was 91 to 99 percent (final values of
0.00028 to 0.00026 mg/1) after biological purification with
activated sludge processes.
A review was made of data on biochemical oxidation of many of the
toxic organic pollutants investigated in laboratory-scale studies
at concentrations higher than would normally be expected in
municipal wastewaters. General observations relating molecular
structure to ease of degradation have been developed for all of
these pollutants. The conclusion reached by study of the limited
data is that biological treatment produces little or no
degradation of fluoranthene. The same study, however, concludes
that fluoranthene would be readily removed by filtration and oil-
water separation and other methods which rely on water
insolubility, or adsorption on other particulate surfaces. This
latter conclusion is supported by the previously cited study
showing significant removal by primary sedimentation.
No studies were found to give data on either the possible
interference of fluoranthene with POTW operation, or the
persistence of fluoranthene in sludges or POTW effluent waters.
Several studies have documented the ubiquity of fluoranthene in
the environment and it cannot be readily determined if this
results from persistence of anthropogenic fluoranthene or the
replacement of degraded fluoranthene by natural processes such as
biosynthesis in plants.
Methylene Chloride (44). Methylene chloride, also called
dichloromethane (CH2CI2), is a colorless liquid manufactured by
chlorination of methane or methyl chloride followed by separation
from the higher chlorinated methanes formed as co-products.
Methylene chloride boils at 40°C, and has a vapor pressure of 362
mm Hg at 20°C. It is slightly soluble in water (20 g/1 at 20°C),
and very soluble in organic solvents. U.S. annual production is
about 250,000 tons.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Methylene chloride is a common industrial solvent found in
insecticides, metal cleaners, paint, and paint and varnish
removers.
Methylene chloride is not generally regarded as highly toxic to
humans. Most human toxicity data are for exposure by inhalation.
Inhaled methylene chloride acts as a central nervous system
depressant. There is also evidence that the compound causes
heart failure when large amounts are inhaled.
Methylene chloride does produce mutation in tests for this
effect. in addition, a bioassay recognized for its extremely
high sensitivity to strong and weak carcinogens produced results
which were marginally significant. Thus potential carcinogenic
effects of methylene chloride are not confirmed or denied, but
are under continuous study. Difficulty in conducting and
interpreting the test results at the low boiling point (4Q°C) of
methylene chloride increases the difficultg of maintaining the
compound in growth media durihg incubation at 37°C; and the
difficulty of removing all impurities, some of which might
themselves be carcinogenic.
For the protection of human health from the toxic properties of
methylene chloride ingested through water and contaminated
aquatic organisms, the ambient water criterion is 0.002 mg/1. The
behavior of methylene chloride in a POTW has not been studied in
any detail. However, the biochemical oxidation of this compound
was studied in one laboratory-scale study at concentrations
higher than those expected to be contained by most municipal
wastewaters. After five days no degradation of methylene
chloride was observed. The conclusion reached is that biological
treatment produces little or no removal by degradation of
methylene chloride in a POTW.
The high vapor pressure of methylene chlor ide is expected to
result in volatilization of the compound from aerobic treatment
steps in a POTW. It has been reported that methylene chloride
inhibits anaerobic processes in a POTW. Methylene chloride that
is not volatilized in the POTW is expected to pass through into
the effluent.
Dichlorobromomethane (48). This compound is a halogenated
aliphatic. Research has shown that halomethanes have
carcinogenic properties, and exposure to this compound may have
adverse effects on human health.
Chlorodibromomethane (51). This compound is a halogenated
aliphatic. Research has shown that halomethanes have
carcinogenic properties, and exposure to this compound may have
adverse effects on human health.
Isophorone (54). Isophorone is an industrial chemical produced
at a level of tens of millions of pounds annually in the U.S. The
chemical name for isophorone is 3,5,5-trimethyl-2-cyclohexen-l-
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GENERAL DEVELOPMENT DOCUMENT
SECT - VI
one and it is also known as trimethyl cyclohexanone and
isoacetophorone. The formula is C5H5(CH3)3O. Normally, it is
produced as the gamma isomer; technical grades contain about 3
percent of the beta isomer (3,5,5-tr imethyl-3-cyclohexen-l-one).
The pure gamma isomer is a water-white liquid, with vapor
pressure less than 1 mm Hg at room temperature, and a boiling
point of 215.2°C. It has a camphor- or peppermint-like odor and
yellows upon standing. It is slightly soluble (12 mg/1) in water
and dissolves in fats and oils.
Isophorone is synthesized from acetone and is used commercially
as a solvent or cosolvent for finishes, lacquers, polyvinyl and
nitrocellulose resins, pesticides, herbicides, fats, oils, and
gums. It is also used as a chemical feedstock.
Because isophorone is an industrially used solvent, most toxicity
data are for inhalation exposure. Oral administration to
laboratory animals in two different studies revealed no acute or
chronic effects during 90 days and no hematological or
pathological abnormalities were reported. Apparently, no studies
have been completed on the carcinogenicity of isophorone.
Isophorone does undergo bioconcentration in the lipids of aquatic
organisms and fish.
Based on subacute data, the ambient water quality criterion for
isophorone ingested through consumption of water and fish is set
at 460 mg/1 for the protection of human health from its toxic
properties
Studies of the effects of isophorone on fish and aquatic
organisms reveal relatively low toxicity compared to some other
toxic pollutants.
The behavior of isophorone in a POTW has not been studied.
However, the biochemical oxidation of many of the toxic organic
pollutants has been investigated in laboratory scale studies at
concentrations higher than would normally be expected in
municipal wastewaters. General observations relating molecular
structure to ease of degradation have been developed for all of
these pollutants. The conclusion reached by the study of the
limited data is that biochemical treatment in a POTW produces
moderate removal of isophorone. This conclusion is consistent
with the findings of an experimental study of microbiological
degradation of isophorone which showed about 45 percent oxidation
in 15 to 20 days in domestic wastewater, but only 9 percent in
salt water. No data were found on the persistence of isophorone
in sewage sludge.
Naphthalene (55). Naphthalene is an aromatic hydrocarbon with
two orthocondensed benzene rings and a molecular formula of
c1Qh8. As such, it is properly classed as a polynuclear aromatic
hydrocarbon (PAH). Pure naphthalene is a white crystalline solid
melting at 80°C. For a solid, it has a relatively high vapor
pressure (0.05 mm Hg at 20°C), and moderate water solubility (19
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
mg/1 at 20°C). Napthalene is the most abundant single component
of coal tar. Production is more than a third of a million tons
annually in the U.S. About three fourths of the production is
used as feedstock for phthalic anhydride manufacture. Most of
the remaining production goes into manufacture of insecticide,
dyestuffs, pigments, and pharmaceuticals. Chlorinated and
partially hydrogenated naphthalenes are used in some solvent
mixtures. Naphthalene is also used as a moth repellent.
Naphthalene, ingested by humans, has reportedly caused vision
loss (cataracts), hemolytic anemia and occasionally renal
disease. These effects of naphthalene ingestion are confirmed by
studies on laboratory animals. No carcinogenicity studies are
available which can be used to demonstrate carcinogenic activity
for naphthalene. Naphthalene does bioconcentrate in aquatic
organisms.
For the protection of human health from the toxic properties of
naphthalene ingested through water and through contaminated
aquatic organisms, the ambient water criterion is determined to
be 143 mg/1.
Only a limited number of studies have been conducted to determine
the effects of naphthalene on aquatic organisms. The data from
those studies show only moderate toxicity.
Naphthalene has been detected in sewage plant effluents at
concentrations up to 0.022 mg/1 in studies carried out by the
U.S. EPA. Influent levels were not reported. The behavior of
naphthalene in a POTW has not been studied. However, recent
studies have determined that naphthalene will accumulate in
sediments at 100 times the concentration in overlying water.
These results suggest that naphthalene will be readily removed by
primary and secondary settling in a POTW, if it is not
biologically degraded.
Biochemical oxidation of many of the toxic organic pollutants has
been investigated in laboratory-scale studies at concentrations
higher than would normally be expected in municipal wastewaters.
General observations relating molecular structure to ease to
degradation have been developed for all of these pollutants. The
conclusion reached by study of the limited data is that
biological treatment produces a high removal by degradation of
naphthalene. One recent study has shown that microorganisms can
degrade naphthalene, first to a dihydro compound, and ultimately
to carbon dioxide and water.
Nitrobenzene (56). Nitrobenzene (C6H5N02), also called
nitrobenzol and oil of mirbane, is a pale yellow, oily liquid,
manufactured by reacting benzene with nitric acid and sulfuric
acid. Nitrobenzene boils at 210°C and has a vapor pressure of
0.3g mm Hg at 25°C. It is slightly soluble in water (1.9 g/1 at
20°C) and is miscible with most organic solvents. Estimates of
annual U.S production vary widely, ranging from 100 to 350
thousand tons.
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GENERAL DEVELOPMENT DOCUMENT
SECT - VI
Almost the entire volume of nitrobenzene produced (97 percent) is
converted to aniline, which is used in dyes, rubber, and
medicinals. Other uses for nitrobenzene include: solvent for
organic synthesis, metal polishes, shoe polish, and perfume.
The toxic effects of ingested or inhaled nitrobenzene in humans
are related to its action in blood; methemoglobinemia and
cyanosis. Nitrobenzene administered orally to laboratory animals
caused degeneration of heart, kidney and liver tissue;
paralysis, and death. Nitrobenzene has also exhibited
teratogenicity in laboratory animals but studies conducted to
determine mutagenicity or carcinogenicity did not reveal either
of these properties
For the prevention of adverse effects due to the organoleptic
properties of nitrobenzene in water, the criterion is 0.030 mg/1.
Data on the behavior of nitrobenzene in POTW are not available.
However, laboratory-scale studies have been conducted at
concentrations higher than those expected to be found in
municipal wastewaters. Biochemical oxidation produced no
degradation after 5, 10, and 20 days. A second study also
reported no degradation after 28 hours, using an acclimated,
phenol-adapted seed culture with nitrobenzene at 100 mg/1. Based
on these limited data, and on general observations relating
molecular structure to ease of biological oxidation, it is
concluded that little or no removal of nitrobenzene occurs during
biological treatment in POTW. The low water solubility and low
vapor pressure of nitrobenzene lead to the expectation that
nitrobenzene will be removed from POTW in the effluent and by
volatilization during aerobic treatment.
2-Nitrophenol (57). 2-Nitrophenol (NO2C5H4OH), also called
orthonitrophenol, is a light yellow crystalline solid,
manufactured commercially by hydrolysis of 2-chloro-nitrobenzene
with aqueous sodium hydroxide, 2-Nitrophenol melts at 45°C and
has a vapor pressure of 1 mm Hg at 49°C. 2-Nitrophenol is
slightly soluble in water (2.1 g/1 at 20°C) and soluble in
organic solvents. This phenol does not react to give a color
with 4-amino-antipyrene, and therefore does not contribute to the
nonconventional pollutant parameter "Total Phenols." U.S. annual
production is 5,000 to 8,000 tons.
The principle use of ortho-nitrophenol is to synthesize
ortho-aminophenol, ortho-nitroanisole, and other dyestuff
intermediates.
The toxic effects of 2-nitrophenol on humans have not been
extensively studied. Data from experiments with laboratory
animals indicate that exposure to this compound causes kidney and
liver damage. Other studies indicate that the compound acts
directly on cell membranes, and inhibits certain enzyme systems
in vitro.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
No information regarding potential teratogencity was found.
Available data indicate that this compound does not pose a
mutagenic hazard to humans. Very limited data for 2-nitrophenol
do not reveal potential carcinogenic effects.
The available data base is insufficient to establish an ambient
water criterion for protection of human health from exposure to
2-nitrophenol. No data are available on which to evaluate the
adverse effects of 2-nitrophenol on aquatic life.
Data on the behavior of 2-nitrophenol in POTW were not available.
However, laboratory-scale studies have been conducted at
concentrations higher than those expected to be found in
municipal wastewater. Biochemical oxidation using adapted
cultures from various sources produced 95 percent degradation in
three to six days in one study. Similar results were reported
for other studies. Based on these data, and general observations
relating molecular structure to ease of biological oxidation, it
is expected that 2-nitrophenol will be biochemically oxidized to
a lesser extent than domestic sewage by biological treatment in
POTWs.
4-Nitrophenol (58) . 4-Nitrophenol (NO2C5H4OH). also called
paranitrophenol, is a colorless to yellowish crystalline solid
manufactured commercially by hydrolysis of 4-chloro-nitrobenzene
with aqueous sodium hydroxide. 4-Nitrophenol melts at 114°C.
Vapor pressure is not cited in the usual sources. 4-Nitrophenol
is slightly soluble in water (15 mg/1 at 25°C) and soluble in
organic solvents. This phenol does not react to give a color
with 4-aminoantipyrene, and therefore does not contribute to the
nonconventional pollutant parameter "Total Phenols." U.S. annual
production is about 20,000 tons.
Paranitrophenol is used to prepare phenetidine, acetaphenetidine,
azo and sulfur dyes, photochemicals, and pesticides.
The toxic effects of 4-nitrophenol on humans have not been
extensively studied. Data from experiments with laboratory
animals indicate that exposure to this compound results in
methemoglobinemia (a metabolic disorder of blood), shortness of
breath, and stimulation followed by depression. Other studies
indicate that the compound acts directly on cell membranes, and
inhibits certain enzyme systems i_n vitro. No information
regarding potential teratogenicity was found. Available data
indicate that this compound does not pose a mutagenic hazard to
humans. Very limited data for 4-nitrophenol do not reveal
potential carcinogenic effects, although the compound has been
selected by the National Cancer Institute for testing under the
Carcinogenic Bioassay Program.
No U.S. standards for exposure to 4-nitrophenol in ambient water
have been established.
Data on the behavior of 4-nitrophenol in a POTW are not
available. However, laboratory-scale studies have been conducted
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
at concentrations higher than those expected to be found in
municipal wastewaters. Biochemical oxidation using adapted
cultures from various sources produced 95 percent degradation in
three to six days in one study. Similar results were reported
for other studies. Based on these data, and on general
observations relating molecular structure to ease of biological
oxidation, it is concluded that complete or nearly complete
removal of 4-nitrophenol occurs during biological treatment in a
POTW.
2,4-Dinitrophenol (59). 2,4-Dinitrophenol (C6H4N2O5), a yellow
crystalline solid, is manufactured by hydrolysis of 2,4-dinitro-
1-chlorobenzene with sodium hydroxide. 2,4-Dinitrophenol sublimes
at 114°C, Vapor pressure is not cited in usual sources. It is
slightly soluble in water (7.0 mg/1 at 25°C) and soluble in
organic solvents. This phenol does not react with 4-
aminoantipyrene and therefore does not contribute to the
nonconventional pollutant parameter "Total Phenols." U.S. annual
production is about 500 tons.
2,4-Dinitrophenol is used to manufacture sulfur and azo dyes,
photochemicals, explosives, and pesticides.
The toxic effects of 2,4-dinitrophenol in humans is generally
attributed to their abi1i ty to uncouple oxidative
phosphorylation. in brief, this means that sufficient 2,4-
dinitrophenol short-circuits cell metabolism by preventing
utilization of energy provided by respiration and glycolysis.
Specific symptoms are gastrointestinal disturbances, weakness,
dizziness, headache, and loss to weight. More acute poisoning
includes symptoms such as: burning thirst, agitation, irregular
breathing, and abnormally high fever. This compound also
inhibits other enzyme systems, and acts directly on the cell
membrane, inhibiting chloride permeability. Ingestion of 2,4-
dinitrophenol also causes cataracts in humans.
Based on available data it appears unlikely that 2,4-
dinitrophenol poses a teratogenic hazard to humans. Results of
studies of mutagenic activity of this compound are inconclusive
as far as humans are concerned. Available data suggest that 2,4-
dinitrophenol does not possess carcinogenic properties.
To protect human health from the adverse effects of 2,4-
dinitrophenol ingested in contaminated water and fish, the
suggested water quality criterion is 0.0686 mg/1.
Data on the behavior of 2,4-dinitrophenol in a POTW are not
available. However, laboratory-scale studies have been conducted
at concentrations higher than those expected to be found in
municipal wastewaters. Biochemical oxidation using a phenol-
adapted seed culture produced 92 percent degradation in 3.5
hours. Similar results were reported for other studies. Based
on these data, and on general observations relating molecular
structure to ease of biological oxidation, it is concluded that
complete or nearly complete removal cf 2,4-dinitrophenol occurs
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
during biological treatment in a FOTW.
4,6-Dinitro-o-cresol ( 60). 4,6-Dinitro-o-cresol (DNOC) is a
yellow crystalline solid derived from o-cresol. DNOC melts at
85.8°C and has a vapor pressure of 0.000052 mm Hg at 20°C. DNOC
is sparingly soluble in water (100 mg/1 at 20°C), while it is
readily soluble in alkaline agueous solutions, ether, acetone,
and alcohol. DNOC is produced by sulfonation of o-cresol
followed by treatment with nitric acid.
DNOC is used primarily as a blossom thinning agent on fruit trees
and as a fungicide, insecticide, and miticide on fruit trees
during the dormant season. It is highly toxic to plants in the
growing stage. DNOC is not manufactured in the U.S. as an
agricultural chemical. Imports of DNOC have been decreasing
recently with only 30,000 pounds imported in 1976.
While DNOC is highly toxic to plants, it is also very toxic to
humans and is considered to be one to the more dangerous
agricultural pesticides. The available literature concerning
humans indicates that DNOC may be absorbed in acutely toxic
amounts through the respiratory and gastrointestinal tracts and
through the skin, and that it accumulates in the blood. Symptoms
of poisoning include profuse sweating, thirst, loss of weight,
headache, malaise, and yellow staining to the skin, hair, sclera,
and conjunctiva.
There is no evidence to suggest that DNOC is teratogenic,
mutagenic, or carcinogenic. The effects of DNOC in the human due
to chronic exposure are basically the same as those effects
resulting from acute exposure. Although DNOC is considered a
cumulative poison in humans, cataract formation is the only
chronic effect noted in any human or experimental animal study,
it is believed that DNOC accumulates in the human body and that
toxic symptoms may develop when blood levels exceed 20 mg/kg.
For the protection of human health from the toxic properties of
dinitro-o-cresol ingested through water and contaminated aquatic
organisms, the ambient water criterion is determined to be 0.0134
mg/1. If contaminated aquatic organisms alone are consumed,
excluding the consumption of water, the ambient water criterion
is determined to be 0.765 mg/1. No data are available on which
to evaluate the adverse effects of 4,6-dini tro-o-cresol on
aquatic life.
Some studies have been reported regarding the behavior of DNOC in
POTW. Biochemical oxidation of DNOC under laboratory conditions
at a concentration of 100 mg/1 produced 22 percent degradation in
3.5 hours, using acclimated phenol adapted seed cultures. In
addition, the nitro group in the number 4 (para) position seems
to impart a destablilizing effect on the molecule. 3ased on
these data and general conclusions relating molecular structure
to biochemical oxidation, it is expected that 4.6-dinitro-o-
cresol will be biochemically oxidized to a lesser extent than
domestic sewage by biological treatment in POTW.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
N-nitrosodiphenylamine (62). N-nitrosodiphenylamine [(CgHs)2NNO],
also called nitrous diphenylamide, is a yellow crystalline solid
manufactured by nitrosation of diphenylamine. it melts at 66°C
and is insoluble in water, but soluble in several organic
solvents other than hydrocarbons. Production in the U.S. has
approached 1,500 tons per year. The compound is used as a
retarder for rubber vulcanization and as a pesticide for control
of scorch (a fungus disease of plants).
N-nitroso compounds are acute iy toxic to every animal species
tested and are also poisonous to humans. N-nitrosodiphenylamine
toxicity in adult rats lies in the mid range of the values for 60
N-nitroso compounds tested. Liver damage is the principal toxic
effect. N-nitrosodiphenylamine, unlike many other N-
nitrosoamines, does not show mutagenic activity. N-
nitrosodiphenylamine has been reported by several investigations
to be non-carcinogenic. However, the compound is capable of
trans-nitrosation and could thereby convert other amines to
carcinogenic N-nitrosoamines. Sixty-seven of 87 N-nitrosoamines
studied were reported to have carcinogenic activity. No water
quality criteria have been proposed for N-nitrosodiphenylamine.
No data are available on the behavior of N-nitrosodiphenylamine
in a POTW. Biochemical oxidation of many of the toxic organic
pollutants have been investigated, at least in laboratory-scale
studies, at concentrations higher than those expected to be
contained in most municipal wastewaters. General observations
have been developed relating molecular structure to ease of
degradation for all the toxic organic pollutants. The conclusion
reached by study of the limited data is that biological treatment
produces little or no removal of N-nitrosodiphenylamine in a
POTW. No information is available regarding possible
interference by N-nitrosodiphenylamine in POTW processes, or on
the possible detrimental effect on sludge used to amend soils in
which crops are grown. However, no interference or detrimental
effects are expected because N-nitroso compounds are widely
distributed in the soil and water environment, at low
concentrations, as a result of microbial action on nitrates and
nitrosatable compounds.
Pentachlorophenol (64). Pentachlorophenol {C5CI5OH) is a white
crystalline solid produced commercially by chlorination of phenol
or polychlorophenols. U.S. annual production is in excess of
20,000 tons. Pentachlorophenol melts at 190°C and is slightly
soluble in water (14 mg/1). Pentachlorophenol is not detected by
the 4-amino antipyrene method.
Pentachlorophenol is a bactericide and fungicide and is used for
preservation of wood and wood products. It is competitive with
creosote in that application. It is also used as a preservative
in glues, starches, and photographic papers. It is an effective
algicide and herbicide.
Although data are available on the human toxicity effects of
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
pentachlorophenol, interpretation of data is frequently
uncertain. Occupational exposure observations must be examined
carefully because exposure to pentachlorophenol is frequently
accompanied by exposure to other wood preservatives.
Additionally, experimental results and occupational exposure
observations must be examined carefully to make sure that
observed effects are produced by the pentachlorophenol itself and
not by the by-products which usually contaminate
pentachlorophenol.
Acute and chronic toxic effects of pentachlorophenol in humans
are similar: muscle weakness, headache, loss of appetite,
abdominal pain, weight loss, and irritation of skin, eyes, and
respiratory tract. Available literature indicates that
pentachlorophenol does not accumulate in body tissues to any
significant extent. Studies on laboratory animals of
distribution of the compound in body tissues showed the highest
levels of pentachlorophenol in liver, kidney, and intestine,
while the lowest levels were in brain, fat, muscle, and bone.
Toxic effects of pentachlorophenol in aquatic organisms are much
greater at pH 6 where this weak acid is predominantly in the
undissociated form than at pH 9 where the ionic form
predominates. Similar results were observed in mammals where
oral lethal doses of pentachlorophenol were lower when the
compound was administered in hydrocarbon solvents (un-ionized
form) than when it was administered as the sodium salt (ionized
form) in water.
There appear to be no significant teratogenic, mutagenic, or
carcinogenic effects of pentachlorophenol.
For the protection of human health from the toxic properties of
pentachlorophenol ingested through water and through contaminated
aquatic organisms, the ambient water quality criterion is deter-
mined to be 0.140 mg/1.
Only limited data are available for reaching conclusions about
the behavior of pentachlorophenol in a POTW. Pentachlorophenol
has been found in the influent to a POTW. In a study of one POTW
the mean removal was 59 percent over a seven-day period.
Trickling filters removed 44 percent at the influent
pentachlorophenol, suggesting that biological degradation occurs.
The same report compared removal of pentachlorophenol at the same
plant and two additional POTW facilities on a later date and
obtained values of 4.4, 19.5, and 28.6 percent removal, the last
value being for the plant which was 59 percent removal in the
original study. Influent concentrations of pentachlorophenol
ranged from 0.0014 to 0 . 0046 mg/'l. Other studies, including the
general review of data relating molecular structure to biological
oxidation, indicate that pentachlorophenol is not removed by
biological treatment processes in a POTW. Anaerobic digestion
processes are inhibited by 0.4 mg/1 pentachlorophenol.
The low water solubility and low volatility of pentachlorophenol
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
lead to the expectation that most of the compound will remain in
the sludge in a POTW. The effect on plants grown on land treated
with pentachlorophenol-containing sludge is unpredictable.
Laboratory studies show that this compound affects crop
germination at 5.4 mg/1. However, photodecomposition of
pentachlorophenol occurs in sunlight. The effects of the various
breakdown products which may remain in the soil were not found in
the literature.
Phenol (65) . Phenol, also called hydroxybenzene and carbolic
acid, is a clear, colorless, hygroscopic, deliquescent, crystal-
line solid at room temperature. Its melting point is 43°C and
its vapor pressure at room temperature is 0.35 mm Hg. It is very
soluble in water (67 gm/1 at 1°C) and can be dissolved in
benzene, oils, and petroleum solids. Its formula is
C6H50H.
Although a small percent of the annual production of phenol is
derived from coal tar as a naturally occurring product, most of
the phenol is synthesized. Two of the methods are fusion of
benzene sulfonate with sodium hydroxide, and oxidation of cumene
followed by cleavage with a catalyst. Annual production in the
U.S. is in excess of one million tons. Phenol is generated
during distillation of wood and the microbiological decomposition
of organic matter in the mammalian intestinal tract.
Phenol is used as a disinfectant, in the manufacture of resins,
dyestuffs, and in pharmaceuticals, and in the photo processing
industry. In this discussion, phenol is the specific compound
which is separated by methylene chloride extraction of an
acidified sample and identified and quantified by GC/MS. Phenol
also contributes to the "Total Phenols," discussed elsewhere
which are determined by the 4-AAP colorimetric method.
Phenol exhibits acute and sub-acute toxicity in humans and
laboratory animals. Acute oral doses of phenol in humans cause
sudden collapse and unconsciousness by its action on the
central nervous system. Death occurs by respiratory arrest.
Sub-acute oral doses in mammals are rapidly absorbed and
quickly distributed to various organs, then cleared from the
body by urinary excretion and metabolism. Long-term exposure
by drinking phenol-contaminated water has resulted in a
statistically significant increase in reported cases of
diarrhea, mouth sores, and burning of the mouth. In
laboratory animals, long-term oral administration at low levels
produced slight liver and kidney damage. No reports were found
regarding carcinogenicity of phenol administered orally -- all
carcinogenicity studies were skin test.
For the protection of human health from phenol ingested through
water and through contaminated aquatic organisms, the
concentration in water should not exceed 3.4 mg/1.
Fish and other aquatic organisms demonstrated a wide range of
sensitivities to phenol concentration. However, acute toxicity
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
values were at moderate levels when compared to other toxic
organic pollutants.
Data have been developed on the behavior of phenol in a POTW.
Phenol is biodegradable by biota present in a POTW. The ability
of a POTW to treat phenol-bearing influents depends upon
acclimation of the biota and the constancy of the phenol
concentration. It appears that an induction period is required to
build up the population of organisms which can degrade phenol.
Too large a concentration will result in upset or pass though in
the POTW, but the specific level causing upset depends on the
immediate past history of phenol concentrations in the influent.
Phenol levels as high as 200 mg/1 have been treated with 95
percent removal in a POTW, but more or less continuous presence
of phenol is necessary to maintain the population of
microorganisms that degrade phenol.
Phenol which is not degraded is expected to pass through the POTW
because of its very high water solubility. However, in a POTW
where chlorination is practiced for disinfection of the POTW
effluent, chlorination of phenol may occur. The products of that
reaction may be toxic pollutants.
The EPA has developed data on influent and effluent
concentrations of total phenols in a study of 103 POTW
facilities. However, the analytical procedure was the 4-AAP
method mentioned earlier and not the GC/MS method specifically
for phenol. Discussion of the study, which of course includes
phenol, is presented under the pollutant heading "Total Phenols."
Phthalate Esters (66-71). Phthalic acid or 1,2-benzene-
dicarboxylic acid, is one of three isomeric benzenedicarboxylic
acids produced by the chemical industry. The other two isomeric
forms are called isophthalic and terephthalic acids. The formula
for all three acids is C5H4(COOH)2. Some esters of phthalic acid
are designated as toxic pollutants. They will be discussed as a
group here, and specific properties of individual phthalate
esters will be discussed afterwards.
Phthalic acid esters are manufactured in the U.S. at an annual
rate in excess of one billion pounds. They are used as
plastiizers, primarily in the production of polyvinyl chloride
(PVC) resins. The most widely used phthalate plasticizer is
bis(2ethylhexyl) phthalate (66) which accounts for nearly one-
third of the phthalate esters produced. This particular ester is
commonly referred to as dioctyl phthalate (DOP) and should not be
confused with one of the less used esters, di-n-octyl phthalate
(69), which is also used as a plasticizer. In addition to these
two isomeric dioctyl phthalates, four other esters, also used
primarily as plasticizers, are designated as toxic pollutants.
They are: butyl benzyl phthalate (67), di-n-butyl phthalate
(68), diethyl phthalate (70), and dimethyl phthalate (71).
industrially, phthalate esters are prepared from phthalic
anhydride and the specific alcohol to form the ester. Some
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
evidence is available suggesting that phthalic acid esters also
may be synthesized by certain plant and animal tissues. The
extent to which this occurs in nature is not known.
Phthalate esters used as plasticizers can be present in
concentrations up to 60 percent of the total weight of the PVC
plastic. The plasticizer is not linked by primary chemical bonds
to the PVC resin. Rather, it is locked into the structure of
intermeshing polymer molecules and held by van der Waals forces.
The result is that the plasticizer is easily extracted.
Plasticizers are responsible for the odor associated with new
plastic toys or flexible sheet that has been contained in a
sealed package.
Although the phthalate esters are not soluble or are only very
slightly soluble in water, they do migrate into aqueous solutions
placed in contact with the plastic. Thus, industrial facilities
with tank linings, wire and cable coverings, tubing, and sheet
flooring of PVC are expected to discharge some phthalate esters
in their raw waste. In addition to their use as plasticizers,
phthalate esters are used in lubricating oils and pesticide
carriers. These also can contribute to industrial discharge of
phthalate esters.
From the accumulated data on acute toxicity in animals, phthalate
esters may be considered as having a rather low order of
toxicity. Human toxicity data are limited. It is thought that
the toxic effects of the esters is most likely due to one of the
metabolic products, in particular the monoester. Oral acute
toxicity in animals is greater for the lower molecular weight
esters than for the higher molecular weight esters.
Orally administered phthalate esters generally produced enlarging
of liver and kidney, and atrophy of testes in laboratory animals.
Specific esters produced enlargement of heart and brain,
spleenitis, and degeneration of central nervous system tissue.
Sub-acute doses administered orally to laboratory animals
produced some decrease in growth and degeneration of the testes.
Chronic studies in animals showed similar effects to those found
in acute and sub-acute studies, but to a much lower degree. The
same organs were enlarged, but pathological changes were not
usually detected.
A recent study of several phthalic esters produced suggestive but
not conclusive evidence that dimethyl and diethyl phthalates have
a cancer liability. Only four of the six toxic pollutant esters
were included in the study. Phthalate esters do bioconcentrate
in fish. The factors, weighted for relative consumption of
various aquatic and marine food groups, are used to calculate
ambient water quality criteria for four phthalate esters. The
values are included in the discussion of the specific esters.
Studies of toxicity of phthalate esters in freshwater and salt
water organisms are scarce. A chronic toxicity test with bis(2-
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
ethylhexyl) phthalate showed that significant reproductive
impairment occurred at 0.003 mg/1 in the freshwater crustacean,
Daphnia magna. In acute toxicity studies, saltwater fish and
organisms showed sensitivity differences of up to eight-fold to
butyl benzyl, diethyl and dimethyl phthalates. This suggests
that each ester must be evaluated individually for toxic effects.
The behavior of phthalate esters in a POTW has not been studied.
However, the biochemical oxidation of many of the toxic organic
pollutants has "been investigated in laboratory-scale studies at
concentrations higher than would normally be expected in
municipal wastewaters. Three of the phthalate esters were
studied. Bis(2-ethylhexyl) phthalate was found to be degraded
slightly or not at all and its removal by biological treatment in
a POTW is expected to be slight or zero. Di-n-butyl phthalate
and diethyl phthalate were degraded to a moderate degree and
their removal by biological treatment in a POTW is expected to
occur to a moderate degree. Using these data and other
observations relating molecular structure to ease of biochemical
degradation of other toxic organic pollutants, the conclusion was
reached that butyl benzyl phthalate and dimethyl phthalate would
be removed in a POTW to a moderate degree by biological
treatment. On the same basis, it was concluded that di-n-octyl
phthalate would be removed to a slight degree or not at all. An
EPA study of seven POTW facilities revealed that for all but di-
n-octyl phthalate, which was not studied, removals ranged from 62
to 87 percent.
No information was found on possible interference wirh POTW oper-
ation or the possible effects on sludge by the phthalate esters.
The water - insoluble phthalate esters (butyl benzyl and di-n-
octyl phthalate) would tend to remain in sludge, whereas the
other four toxic pollutant phthalgte esters with water
solubilities ranging from 50 mg/1 to 4.5 mg/1 would probably pass
through into the POTW effluent.
Bis(2-ethylhexyl) Phthalate (66). In addition to the general
remarks and discussion on phthalate esters, specific information
on bis(2-ethylhexyl) phthalate is provided. Little information
is available about the physical properties of bis(2-ethylhexyl)
phthalate. It is a liquid boiling at 387°C at 5 mm Hg and is
insoluble in water. Its formula is CgH4(COOCgH]^ )2. This toxic
pollutant constitutes about one-third of the phthalate ester
production in the U.S. It is commonly referred to as dioctyl
phthalate, or DOP, in the plastics industry where it is the most
extensively used compound for the plasticization of polyvinyl
chloride (PVC). Bis(2-ethylhexyl) phthalate has been approved by
the FDA for use in plastics in contact with food. Therefore, it
may be found in wastewaters coming in contact with discarded
plastic food wrappers as well as the PVC films and shapes
normally found in industrial plants. This toxic pollutant is
also a commonly used organic diffusion pump oil, where its low
vapor pressure is an advantage.
For the protection of human health from the toxic properties of
82
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
bis(2-ethylhexyl) phthalate ingested through water and through
contaminated aquati c organisms, the ambient water quality
criterion is determined to be 15 mg/1. If contaminated aquatic
organisms alone are consumed, excluding the consumption of water,
the ambient water criteria is determined to be 50 mg/1.
Although the behavior of bis(2-ethylhexyl) phthalate in a POTW
has not been studied, biochemical oxidation of this toxic
pollutant has been studied on a laboratory scale at
concentrations higher than would normally be expected in
municipal wastewater. In fresh water with a non-acclimated seed
culture, no biochemical oxidation was observed after 5, 10, and
20 days. However, with an acclimated seed culture, biological
oxidation occurred to the extents of 13, 0, 6, and 23 percent of
theoretical after 5, 10, 15, and 20 days, respectively. Bis{2-
ethylhexyl) phthalate concentrations were 3 to 10 mg/1. Little
or no removal of bis(2-ethylhexyl) phthalate by biological
treatment in a POTW is expected.
Butyl Benzyl Phthalate (67). In addition to the general remarks
and discussion on phthalate esters, specific information on butyl
benzyl phthalate is provided. No information was found on the
physical properties of this compound.
Butyl benzyl phthalate is used as a plasticizer for PVC. Two
special applications differentiate it from other phthalate
esters. It is approved by the U.S. FDA for food contact in
wrappers and containers, and it is the industry standard for
plasticization of vinyl flooring because it provides stain
resistance.
No ambient water quality criterion is proposed for butyl benzyl
phthalate.
Butyl benzyl phthalate removal in a POTW by biological treatment
is expected to occur to a moderate degree.
Di-n-butyl Phthalate (68). In addition to the general remarks
and discussion on phthalate esters, specific information on di-
n-butyl phthalate (DBP) is provided. DBP is a colorless oil
liquid, boiling at 340°C. Its water solubility at room
temperature is reported to be 0.4 g/1 and 4.5 g/1 in two
different chemistry handbooks. The formula for DBP,
C6H4(COOC4Hg)2 is the same as for its isomer, di-isobutyl
phthalate. DBP production is 1 to 2 percent of total U.S.
phthalate ester production.
Dibutyl phthalate is used to a limited extent as a plasticizer
for polyvinyl chloride (PVC). It is not approved for contact
with food. It is used in liquid lipsticks and as a dilluent for
polysulfide dental impression materials. DBP is used as a
plasticizer for nitrocellulose in making gun powder, and as a
fuel in solid propeilants for rockets. Further uses are
insecticides, safety glass manufacture, textile lubricating
agents, printing inks, adhesives, paper coatings, and resin
83
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
solvents.
For protection of human health from the toxic properties of
dibutyl phthalate ingested through water and through contaminated
aquatic organisms, the ambient water quality criterion is
determined to be 34 mg/1. If contaminated aquatic organisms
alone are consumed, excluding the consumption of water, the
ambient water criterion is 154 mg/1.
Although the behavior of di-n-butyl phthalate in a POTW has not
been studied, biochemical oxidation of this toxic pollutant has
been studied on a laboratory scale at concentrations higher than
would normally be expected in municipal wastewaters. Biochemical
oxidation of 35, 43, and 45 percent of theoretical oxidation were
obtained after 5, 10, and 20 days, respectively, using sewage
microorganisms as an unacclimated seed culture.
Biological treatment in a POTW is expected to remove di-n-butyl
phthalate to a moderate degree.
Di-n-octyl Phthalate (69). In addition to the general remarks
and discussion on phthalate esters, specific information on di-n-
octyl phthalate is provided. Di-n-octyl phthalate is not to be
confused with the isomeric bis(2-ethylhexyl) phthalate which is
commonly referred to in the plastics industry as DOP. Di-n-
octyl phthalate is a liquid which boils at 220 C at 5 mm Hg. It
is insoluble in water. Its molecular formula is CgH4(COOCqH;l7)2.
Its production constitutes about 1 percent of all phthalate ester
production in the U.S.
Industrially, di-n-octyl phthalate is used to plasticize
polyvinyl chloride (PVC) resins.
No ambient water quality criterion is proposed for di-n-octyl
phthalate.
Biological treatment in a POTW is expected to lead to little or
no removal of di-n-octyl phthalate.
Diethyl Phthalate (70) . In addition to the general remarks and
discussion on phthalate esters, specific information on diethyl
phthalate is provided. Diethyl phthalate, or DEP, is a colorless
liquid boiling at 296°C, and is insoluble in water. Its
molecular formula is C5H4(COOC2H5)2• Production of diethyl
phthalate constitutes about 1.5 percent of phthalate ester
production in the U.S.
Diethyl phthalate is approved for use in plastic food containers
by the U.S. FDA. In addition to its use as a polyvinyl chloride
(PVC) plasticizer, DEP is used to plasticize cellulose nitrate
for gun powder, to dilute polysulfide dental impression materials
and as an accelerator for dyeing triacetate fibers. An
additional use which would contribute to its wide distribution in
the environment is as an approved special denaturant for ethyl
alcohol. The alcohol-containing products for which DEP is an
84
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
approved denaturant include a wide range of personal care items
such as bath preparations, bay rum, colognes, hair preparations,
face and hand creams, perfumes and toilet soaps. Additionally,
this denaturant is approved for use in biocides, cleaning
solutions, disinfectants, insecticides, fungicides, and room
deodorants which have ethyl alcohol as part of the formulation.
It is expected, therefore, that people and buildings would have
some surface loading of this toxic pollutant which would find its
way into raw wastewaters.
For the protection of human health from the toxic properties of
diethyl phthalate ingested through water and through contaminate
aquatic organisms, the ambient water quality criterion is deter-
mined to be 350 mg/1. If contaminated aquatic organisms alone
are consumed, excluding the consumption of water, the ambient
water criterion is 1,800 mg/1.
Although the behavior of diethyl phthalate in a POTW has not been
studied, biochemical oxidation of this toxic pollutant has been
studied on a laboratory scale at concentrations higher than would
normally be expected in municipal wastewaters. Biochemical
oxidation of 79, 84, and 89 percent of theoretical was observed
after 5, 15, and 20 days, respectively. Biological treatment in
a POTW is expected to lead to a moderate degree of removal of
diethyl phthalate.
Dimethyl Phthalate (71). In addition to the general remarks and
discussion on phthalate esters, specific information on dimethyl
phthalate (DMP) is Provided. DMP has the lowest molecular weight
of the phthalate esters - M.W. = 194 compared to M.W. of 391 for
bisf2-ethylhexyl) phthalate. DMP has a boiling point of
282°C. It is a colorless liquid, soluble in water to the extent
of 5 mg/1. its molecular formula is C5H4(COOCH3)2.
Dimethyl phthalate production in the U.S. is just under 1 percent
of total phthalate ester production. DMP is used to some extent
as a plasticizer in cellulosics; however, its principal specific
use is for dispersion of polyvinylidene fluoride (PVDF). PVDF is
resistant to most chemicals and finds use as electrical
insulation, chemical process equipment (particularly pipe), and
as a case for long-life finishes for exterior metal siding. Coil
coating techniques are used to apply PVDF dispersions to aluminum
or galvanized steel siding.
For the protection of human health from the toxic properties of
dimethyl phthalate ingested through water and through
contaminated aquatic organisms, the ambient water criterion is
determined to be 313 mg/1. If contaminated aquatic organisms
alone are consumed excluding the consumption of water, the
ambient water criterion is 2,900 mg/1.
Based on limited data and observations relating molecular
structure to ease of biochemical degradation of other toxic
organic pollutants, it is expected that dimethyl phthalate will
be biochemically oxidized to a lesser extent than domestic sewage
85
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
by biological treatment in a POTW.
Polynuclear Aromatic Hydrocarbons (72-84). The polynuclear
aromatic hydrocarbons (PAH) selected as toxic pollutants are a
group of 13 compounds consisting of substituted and unsubstituted
polycyclic aromatic r ings. These compounds and their structurial
formulae are shown in Figure VI-3 (page 143). The general class
of PAH includes heterocyclics, but none of those were selected as
toxic pollutants. PAH are formed as the result of incomplete
combustion when organic compounds are burned with insufficient
oxygen. PAH are found in coke oven emissions, vehicular
emissions, and volatile products of oil and gas burning. The
compounds chosen as toxic pollutants are 1isted with their
structural formulae and melting points (m.p.). All are
relatively insoluble in water.
Some of these toxic pollutants have commercial or industrial
uses. Benzo(a)anthracene, benzo(a)pyrene, chrysene, anthracene,
dibenzo(a,h)anthracene, and pyrene are all used as antioxidants.
Chrysene, acenaphthylene, anthracene, fluorene, phenanthrene, and
pyrene are all used for synthesis of dyestuffs or other organic
chemicals. 3,4-Benzofluoranthrene, benzo(k)fluoranthene, benzo-
(ghi)perylene, and indeno (1,2,3-cd)pyrene have no known
industrial uses, according to the results of a recent literature
search.
Several of the PAH toxic pollutants are found in smoked meats, in
smoke flavoring mixtures, in vegetable oils, and in coffee.
Consequently, they are also found in many drinking water
supplies. The wide distribution of these pollutants in complex
mixtures with the many other PAHs which have not been designated
as toxic pollutants results in exposures to humans that cannot be
associated with specific individual compounds.
The screening and verification analysis procedures used for the
toxic organic pollutants are based on gas chromatography (GC).
Three pairs of the PAH have identical elution times on the column
specified in the protocol, which means that the parameters of the
pair are not differentiated. For these three pairs [anthracene
(78) - phenanthrene (81); 3,4-benzofluoranthene (74) - benzo(k)-
fluoranthene (75); and benzo(a)anthracene (72) - chrysene (76)]
results are obtained and reported as "either-or." Either both
are present in the combined concentration reported, or one is
present in the concentration reported.
There are no studies to document the possible carcinogenic risks
to humans by direct ingestion. Air pollution studies indicate an
excess of lung cancer mortality among workers exposed to large
amounts of PAH containing materials such as coal gas, tars, and
coke-oven emissions. However, no definite proof exists that the
PAH present in these materials are responsible for the cancers
observed.
Animal studies have demonstrated the toxicity of PAH by oral and
dermal administration. The carcinogenicity of PAH has been
86
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
traced to formation of PAH metabolites which, in turn, lead to
tumor formation. Because the levels of PAH which induce cancer
are very low, little work has been done on other health hazards
resulting from exposure. It has been established in animal
studies that tissue damage and systemic toxicity can result from
exposure to non-carcinogenic PAH compounds.
Because there were no studies available regarding chronic oral
exposures to PAH mixtures, proposed water quality criteria were
derived using data on exposure to a single compound. Two studies
were selected, one involving benzo{a)pyrene ingestion and one
involving dibenzo(a,h)anthracene ingestion. Both are known
animal carcinogens.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to polynuclear aromatic
hydrocarbons (PAH) through ingestion of water and contaminated
aquatic organisms, the ambient water concentration is zero.
Concentrations of PAH estimated to result in additional risk of 1
in 100,000 were derived by the EPA and the Agency is considering
setting criteria at an interim target risk level in the range of
10" , 10~ , or 10"5 with corresponding criteria of 0.000000097
mg/1, 0.00000097 mg/1, and 0.0000097 mg/1, respectively.
No standard toxicity tests have been reported for freshwater or
saltwater organisms and any of the 13 PAH discussed here.
The behavior of PAH in a POTW has received only a limited amount
of study. It is reported that up to 90 percent of PAH entering a
POTW will be retained in the sludge generated by conventional
sewage treatment processes. Some of the PAH can inhibit
bacterial growth when they are present at concentrations as low
as 0.018 mg/1. Biological treatment in activated sludge units
has been shown to reduce the concentration of phenanthrene and
anthracene to some extent; however, a study of biochemical
oxidation of fluorene on a laboratory scale showed no degradation
after 5, 10, and 20 days. On the basis of that study and studies
of other toxic organic pollutants, some general observations were
made relating molecular structure to ease of degradation. Those
observations lead to the conclusion that the 13 PAH selected to
represent that group as toxic pollutants will be removed only
slightly or not at all by biological treatment methods in a POTW.
Based on their water insolubility and tendency to attach to
sediment particles, very little pass through of PAH to POTW
effluent is expected. Sludge contamination is the likely
environmental fate, although no data are available at this time
to support any conclusions about contamination of land by PAH on
which sewage sludge containing PAH is spread.
Tetrachl oroethvlene (85). Tetrachloroethylene (CC112sCCl2), also
called perchloroethylene and PCE, is a colorless, nonflammable
liquid produced mainly by two methods - chlorination and
pyrolysis of ethane and propane, and oxycnlorination of
dichloroethane. U.S. annual production exceeds 300,000 tons.
PCE boils at 121°C, a vapor pressure of 19 mm Kg at 20°C. It is
87
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
insoluble in water but soluble in organic solvents.
Approximately two-thirds of the U.S. production of PCE is used
for dry cleaning. Textile processing and metal degreasing, in
equal amounts consume about one-quarter of the U.S. production.
The principal toxic effect of PCE on humans is central nervous
system depression when the compound is inhaled. Headache,
fatigue, sleepiness, dizziness, and sensations of intoxication
are reported. Severity of effects increases with vapor
concentration. High integrated exposure (concentration times
duration) produces kidney and liver damage. Very limited data on
PCE ingested by laboratory animals indicate liver damage occurs
when PCE is administered by that route. PCE tends to distribute
to fat in mammalian bodies.
One report found in the literature suggests, but does not
conclude, that PCE is teratogenic. PCE has been demonstrated to
be a liver carcinogen in B6C3-F1 mice.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to tetrachlorethylene through
ingestion of water and contaminated aquatic organisms, the
ambient water concentration is zero. Concentrations of
tetrachloroethylene estimated ggo result . ng additional lifetime
cancer risk levels of 10" , 10 , and 10~* are 0.00002 mg/1,
0.0002 mg/1, and 0.002 mg/1, respectively.
No data were found regarding the behavior of PCE in a POTW. Many
of the toxic organic pollutants have been investigated, at least
in laboratory-scale studies, at concentrations higher than those
expected to be contained by most municipal wastewaters. General
observations have been developed relating molecular structure to
ease of degradation for all of the toxic organic pollutants. The
conclusion reached by the study of the limited data is that
biological treatment produces a moderate removal of PCE in a POTW
by degradation. No information was found to indicate that PCE
accumulates in the sludge, but some PCE is expected to be
adsorbed onto settling particles. Some PCE is expected to be
volatilized in aerobic treatment processes and little, if any, is
expected to pass through into the effluent from the POTW.
Toluene (86) . Toluene is a clear, colorless liquid with a
benzene-like odor. It is a naturally occurring compound derived
primarily from petroleum or petrochemical processes. Some
toluene is obtained from the manufacture of metallurgical coke.
Toluene is also referred to as toluol, methylbenzene, methacide,
and phenylmethane. It is an aromatic hydrocarbon with the
formula C6H5CH3. It boils at 111°C and has a vapor pressure of
Hg at room temperature. The water solubility of toluene is 535
mg/1, and it is miscible with a variety of organic solvents.
Annual production of toluene in the U.S. is greater than two
million metric tons. Approximately two-thirds of the toluene is
converted to benzene and the remaining 30 percent is divided
approximately equally into chemical manufacture, and use as a
88
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
paint solvent and aviation gasoline additive. An estimated 5,000
metric tons is discharged to the environment annually as a
constituent in wastewater.
Most data on the effects of toluene in human and other mammals
have been based on inhalation exposure or dermal contact studies.
There appear to be no reports of oral administration of toluene
to human subjects. A long-term toxicity study on female rats
revealed no adverse effects on growth, mortality, appearance and
behavior, organ to body weight ratios, blood-urea nitrogen
levels, bone marrow counts, peripheral blood counts, or
morphology of major organs. The effects of inhaled toluene on
the central nervous system, both at high and low concentrations,
have been studied in humans and animals. However, ingested
toluene is expected to be handled differently by the body because
it is absorbed more slowly and must first pass through the liver
before reaching the nervous system. Toluene is extensively and
rapidly metabolized in the liver. One of the principal metabolic
products of toluene is benzoic acid, which itself seems to have
little potential to produce tissue injury.
Toluene does not appear to be teratogenic in laboratory animals
or man. Nor is there any conclusive evidence that toluene is
mutagenic. Toluene has not been demonstrated to be positive in
any in vitro mutagenicity or carcinogenicity bioassay system, nor
to be carcinogenic in animals or man.
Toluene has been found in fish caught in harbor waters in the
vicinity of petroleum and petrochemical plants. Bioconcentration
studies have not been conducted, but bioconcentration factors
have been calculated on the basis of the octanol-water partition
coefficient.
For the protection of human health from the toxic properties of
toluene ingested through water and through contaminated aquatic
organisms, the ambient water criterion is determined to be 14.3
mg/1. If contaminated aquatic organisms alone are consumed
excluding the consumption of water, the, ambient water criterion
is 424 mg/1. Available data show that the adverse effects on
aquatic life occur at concentrations as low as 5 mg/1.
Acute toxicity tests have been conducted with toluene and a
variety of freshwater fish and Daphnia magna. The latter appears
to be significantly more resistant than fish. No test results
have been reported for the chronic effects of toluene on
freshwater fish or invertebrate species.
No detailed study of toluene behavior in a POTW is available.
However, the biochemical oxidation of many of the toxic
pollutants has been investigated in laboratory scale studies at
concentrations greater than those expected to be contained by
most municipal wastewaters. At toluene concentrations ranging
from 3 to 250 mg/1 biochemical oxidation proceeded to 50 percent
of theoretical or greater. The time period varied from a few
hours to 20 days depending on whether or not the seed culture was
89
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
acclimated. Phenol adapted acclimated seed cultures gave the
most rapid and extensive biochemical oxidation.
Based on study of the limited data, it is expected that toluene
will be biochemically oxidized to a lesser extent than domestic
sewage by biological treatment in a POTW. The volatility and
relatively low water solubility of toluene lead to the
expectation that aeration processes will remove significant
quantities of toluene from the POTW. The EPA studied toluene
removal in seven POTW facilities. The removals ranged from 40 to
10C) percent. Sludge concentrations of toluene ranged from 54 x
10 to 1.85 mg/1.
Tr ichloroethylene (87). Trichloroethylene (1,1,2-
trichloroethylene or TCE) is a clear, colorless liquid boiling at
87°C. It has a vapor pressure of 77 mm Hg at room temperature and
is slightly soluble in water (1 gm/1). U.S. production is
greater than 0.25 million metric tons annually. It is produced
from tetrachloroethane by treatment with lime in the presence of
water.
TCE (CHCl=CCl2) is used for vapor phase degreasing of metal
parts, cleaning and drying electronic components, as a solvent
for paints, as a refrigerant, for extraction of oils, fats, and
waxes, and for dry cleaning. Its widespread use and relatively
high volatility result in detectable levels in many parts of the
environment.
Data on the effects produced by ingested TCE are limited. Most
studies have been directed at inhalation exposure. Nervous
system disorders and liver damage are frequent results of
inhalation exposure. In the short term exposures, TCE acts as a
central nervous system depressant - it was used as an anesthetic
before its other long-term effects were defined.
TCE has been shown to induce transformation in a highly sensitive
in vitro Fischer rat embryo cell system (F1706) that is used for
identifying carcinogens. Severe and persistent toxicity to the
liver was recently demonstrated when TCE was shown to produce
carcinoma of the liver in mouse strain B6C3F1. One systematic
study of TCE exposure and the incidence of human cancer was based
on 518 men exposed to TCE. The authors of that study concluded
that although the cancer risk to man cannot be ruled out,
exposure to low levels of TCE probably does not present a very
serious and general cancer hazard.
TCE is bioconcentrated in aquatic species, making the consumption
of such species by humans a significant source of TCE. For the
protection of human health from the potential carcinogenic
effects of exposure to trichloroethylene through ingestion of
water and contaminated aquatic organisms, the ambient water
concentration is zero. Concentrations of trichloroethylene
estimated to result in additional lifetime cancer risks of 10"',
1Q~6, and 10~5 are 0.00027 mg/1, 0,0027 mg/1, and 0,027 mg/1,
respectively. If contaminated aquatic organisms alone are
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GENERAL DEVELOPMENT DOCUMENT
SECT - VI
consumed, excluding the consumption of water, the water
concentration should be less than 0.807 mg/1 to keep the
additional lifetime cancer risk below 10 .
Only a very limited amount of data on the effects of TCE on
freshwater aquatic life are available. One species of fish (fat-
head minnows) showed a loss of equilibrium at concentrations
below those resulting in lethal effects.
The behavior of trichloroethylene in a POTW has not been studied.
However, in laboratory-scale studies of toxic organic pollutants,
TCE was subjected to biochemical oxidation conditions. After 5,
10, and 20 days no biochemical oxidation occurred. On the basis
of this study and general observations relating molecular
structure to ease of degradation, the conclusion is reached that
TCE would undergo no removal by biological treatment in a POTW.
The volatility and relatively low water solubility of TCE is
expected to result in volatilization of some of the TCE in
aeration steps in a POTW.
Vinyl Chloride (88). No freshwater organisms have been tested
with vinyl chloride and no statement can be made concerning acute
or chronic toxicity.
For the maximum protection of human health from the potential
carcinogenic effects due to exposure of vinyl chloride through
ingestion of contaminated water and contaminated aquatic
organisms, the ambient water concentrations should be zero based
on the non-threshold assumption for this chemical. However, zero
level may not be attainable at the present time. Therefore, the
levels which may result in incremental increase of cancer risk
over the lifetime are estimated at 10" , 10" , and 10" . The
corresponding recommended criteria are 0.020 mg/1, 0.0020 mg/1,
and 0.00020 mg/1, respectively. For consumption of aquatic
organisms only, excluding consumption of water, the levels are
5.246 mg/1, 0.525 mg/1, and 0.052 mg/1, respectively.
Vinyl chloride has been used for over 40 years in producing
polyvinyl chloride (PVC) which in turn is the most widely used
material in the manufacture of plastics throughout the world. Of
the estimated 18 billion pounds of vinyl chloride produced
worldwide in 1972, about 25 percent was manufactured in the
United States. Production of vinyl chloride in the United States
reached slightly over 5 billion pounds in 1978.
Vinyl chloride and polyvinyl chloride are used in the manufacture
of numerous products in building and construction, the automotive
industry, for electrical wire insulation and cables, piping,
industrial and household equipment, packaging for food products,
medical supplies, and is depended upon heavily by the rubber,
paper, and glass industries. Polyvinyl chloride and vinyl
chloride copolymers are distributed and processed in a variety of
forms including dry resins, plastisol (dispersions in
plasticizers), organosol (dispersions in plasticizers plus
volatile solvent), and latex (colloidal dispersion in water).
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Latexes are used to coat or impregnate paper, fabric, or leather.
Vinyl chloride (CH2CHCI: molecular weight 62.5) is a highly
flammable chloroolefinic hydrocarbon which emits a sweet or
that of air. ± l nets <1 uuj.j-j.ny puint ui -j.o.3 v- duu a melting
point of -153.8°C. Its solubility in water at 28°C is 0.11 g/100
g water and it is soluble in alcohol and very soluble in ether
and carbon tetrachloride. Vinyl chloride is volatile and readily
passes from solution into the gas phase under most laboratory and
ecological conditions. Many salts such as soluble silver and
copper salts, ferrous chloride, platinous chloride, iridium
dichloride, and mercurous chloride to name a few, have the
ability to form complexes with vinyl chloride which results in
its increased solubility in water. Conversely, alkali metal
salts such as sodium or potassium chloride may decrease the
solubility of vinyl chloride in ionic strengths of the aqueous
solution. Therefore, the amounts of vinyl chloride in water
could be influenced significantly by the presence of salts.
Vinyl chloride introduced into aquatic systems will most probably
be quickly transferred to the atmosphere through volatilization.
In fact, results from model simulations indicate that vinyl
chloride should not remain in an aquatic ecosystem under most
natural conditions.
Based on the information found, it does not appear that oxidation
hydrolysis, biodegradation or sorption, are important fate
processes for vinyl chloride in the aquatic environment.
Based on the 1982 POTW study, "Fate of Priority Pollutants in
Publicly Owned Treatment Works, Final Report," Effluent Guide-
lines Division, U.S. Environmental Protection Agency, EPA 440/1-
82/303, September 1983, the removal efficiency for vinyl chloride
at a POTW with secondary treatment is 94 percent.
4,4'-DDD (94 ) . 4,4'-DDD is toxic by ingestion, inhalation, skin
absorption, and is combustible.
a-Endosul fan-alpha J_95_^. Endosulfan is toxic by ingestion,
inhalation and skin absorption.
a-BHC-alpha (102) . BHC-alpha is toxic by ingestion, skin
absorption, is an eye irritant, and a central nervous system
depressant.
b-BHC-beta (103). BHC-beta is moderately toxic by inhalation,
highly toxic by ingestion, and is a strong irritant by skin
absorption. It acts as a central nervous system depressant.
Polycnlorinated Biphenyls J_106 - 112). Poiychlorinated biphenyls
(c12H10-ncln'H10-ncln where n can range from 1 to 10), designated
PCBs, are chlorinated derivatives of biphenyls. The commercial
products are complex mixtures of chlorobiphenvls, but are no
longer produced in the U.S. The mixtures produced formerly were
pleasant odor
than twice
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
characterized by the percentage chlorination. Direct chlorination
of biphenyl was used to produce mixtures containing from 21 to 70
percent chlorine. Seven of these mixtures have been selected as
toxic pollutants:
Toxic
Pollu- Range (°C)
tant
Percent
Distilla-
Pour
Water
No.
Name
Chlorine
tion
Point (°C)
Solubility
Arochlor
106
1242
42
325-366
-19
240
107
1254
54
365-390
10
12
108
1221
20.5-21.5
275-320
1
<200
109
1232
31.4-32.5
290-325
-35.5
.—
110
1248
48
340-375
- 7
54
111
1260
60
385-420
31
2.7
112
1016
41
323-356
—
225-250
The arochlors 1221, 1232, 1016, 1242, and 1248 are colorless,
oily liquids; 1254 is a viscous liquid; 1260 is a sticky resin at
room temperature. Total annual U.S. production of PCBs averaged
about 20,000 tons in 1972 to 1974.
Prior to 1971, PCBs were used in several applications including
plasticizers, heat transfer 1iquids, hydraulic fluids,
lubricants, vacuum pump and compressor fluids, and capacitor and
transformer oils. After 1970, when PCB use was restricted to
closed systems, the latter two uses were the only commercial
applications.
The toxic effects of PCB's ingested by humans have been reported
to range from acne-like skin eruptions and pigmentation of the
skin to numbness of limbs, hearing and vision problems, and
spasms. Interpretation of results is complicated by the fact
that the very highly toxic polychlorinated dibenzofurans (PCDFs)
are found in many commercial PCB mixtures. Photochemical and
thermal decomposition appear to accelerate the transformation of
PCBs to PCDFs. Thus the specific effects of PCBs may be masked
by the effects of PCDFs. However, if PCDFs are frequently
present to some extent in any PCB mixture, then their effects may
be properly included in the effects of PCB mixtures.
Studies of effects of PCBs in laboratory animals indicate that
liver and kidney damage, large weight losses, eye discharges, and
interference with some metabolic processes occur frequently.
Teratogenic effects of PCBs in laboratory animals have been
observed, but are rare. Growth retardations during gestation,
and reproductive failure are more common effects observed in
studies of PCB teratogenicity. Carcinogenic effects of PCBs
have been studied in laboratory animals with results interpreted
as positive. Specific reference has been made to liver cancer in
rats in the discussion of water quality criterion formulation.
For the maximum protection of human health from the potential
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
For the maximum protection of human health from the potential
carcinogenic effects of exposure to PCBs through ingestion of
water and contaminated aquatic organisms, the ambient water
concentration should be zero. Concentrations of PCBs estimated
to result in additional lifetime cancer risk at risk levels of
10-V io~6, and 10 are 0.0000000026 mg/1, 0.000000026 mg/1,
and 0,00000026 mg/1, respectively.
The behavior of PCBs in a POTW has received limited study. Most
PCB's will be removed with sludge. One study showed removals of
82 to 89 percent, depending on suspended solid removal. The
PCB's adsorb onto suspended sediments and other particulates. In
laboratory-scale experiments with PC8 1221, 81 percent was
removed by degradation in an activated sludge system in 47 hours.
Biodegradation can form polychlorinated dibenzofurans which are
more toxic than PCBs (as noted earlier). PCBs at
concentrations of 0.1 to 1,000 mg/1 inhibit or enhance bacterial
growth rates, depending on the bacterial culture and the
percentage chlorine in the PCB. Thus, activated sludge may be
inhibited by PCBs. Based on studies of bioaccumulation of PCBs
in food crops grown on soils amended with PCB-containing sludge,
the U.S. FDA has recommended a limit of 10 mg PCB/kg dry weight
of sludge used for application to soils bearing food crops.
Antimony (114). Antimony, classified as a non-metal or
metalloid, is a silvery white, brittle crystal1ine solid.
Antimony is found in small ore bodies throughout the world.
Principal ores are oxides of mixed antimony valences, and an
oxysulfide ore. Complex ores with metals are important because
the antimony is recovered as a by-product. Antimony melts at
631°C, and is a poor conductor of electricity and heat.
Annual U.S. consumption of primary antimony ranges from 10,000 to
20,000 tons. About half is consumed in metal products - mostly
antimonial lead for lead acid storage batteries, and about half
in non-metal products. A principal compound is antimony trioxide
which is used as a flame retardant in fabrics, and as an
opacifier in glass, ceramics, and enamels. Several antimony
compounds are used as catalysts in organic chemicals synthesis,
as fluorinating agents (the antimony fluoride), as pigments, and
in fireworks. Semiconductor applications are economically
significant.
Essentially no information on antimony-induced human health
effects has been derived from community epidemiology studies. The
available data are in literature relating effects observed with
therapeutic or medicinal uses of antimony compounds and
industrial exposure studies. Large therapeutic doses of
antimonial compounds, usually used to treat schistisomiasis, have
caused severe nausea, vomiting, convulsions, irregular heart
action, liver damage, and skin rashes. Studies of acute
industrial antimony poisoning have revealed loss of appetite,
diarrhea, headache, and dizziness in addition to the symptoms
found in studies of therapeutic doses of antimony.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
For the protection of human health from the toxic properties of
antimony ingested through water and through contaminated aquatic
organisms the ambient water criterion is determined to be 0.146
mg/1. If contaminated aquatic organisms are consumed, excluding
the consumption of water, the ambient water criterion is deter-
mined to be 45 mg/1. Available data show that adverse effects on
aquatic life occur at concentrations higher than those cited for
human health risks.
Very little information is available regarding the behavior of
antimony in a POTW, The limited solubility of most antimony
compounds expected in a POTW (i.e., the oxides and sulfides),
suggests that at least part of the antimony entering a POTW will
be precipitated and incorporated into the sludge. However, some
antimony is expected to remain dissolved and pass through the
POTW into the effluent. Antimony compounds remaining in the
sludge under anaerobic conditions may be connected to stibine
(SbH3), a very soluble and very toxic compound. There are no
data to show antimony inhibits any POTW processes. Antimony is
not known to be essential to the growth of plants, and has been
reported to be moderately toxic. Therefore, sludge containing
large amounts of antimony could be detrimental to plants if it is
applied in large amounts to cropland.
Arsenic (115). Arsenic is classified as a non-metal or
metalloid. Elemental arsenic normally exists in the alpha-
crystalline metallic form which is steel gray and brittle, and in
the beta form which is dark gray and amorphous. Arsenic sublimes
at 615°C. Arsenic is widely distributed throughout the
world in a large number of minerals. The most important
commercial source of arsenic is as a by-product from treatment of
copper, lead, cobalt, and gold ores. Arsenic is usually marketed
as the trioxide (As20 3). Annual U.S. production of the trioxide
approaches 40,000 tons.
The principal use of arsenic is in agricultural chemicals
(herbicides) for controlling weeds in cotton fields. Arsenicals
have various applications in medicinal and veterinary use, as
wood preservatives, and in semiconductors.
The effects of arsenic in humans were known by the ancient Greeks
and Romans. The principal toxic effects are gastrointestinal
disturbances. Breakdown of red blood cells occurs. Symptoms of
acute poisoning include vomiting, diarrhea, abdominal pain
lassitude, dizziness, and headache. Longer exposure produced
dry, falling hair, brittle, loose nails, eczema, and exfoliation.
Arsenicals also exhibit teratogenic and mutagenic effects in
humans. Oral administration of arsenic compounds has been
associated clinically with skin cancer for nearly one hundred
years. Since 1888 numerous studies have linked occupational
exposure and therapeutic administration of arsenic compounds to
increased incidence of respiratory and skin cancer.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to arsenic through ingestion of
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
water and contaminated aquatic organisms, the ambient water
concentration is zero. Concentrations of arsenic estimated to
result in additional lifetime cancer risk levels of 10"' , 10~°,
and 105 are 2.2 x 10-7 mg/1, 2.2 x 10-6 mg/1, and 2,2 x 10-5
mg/1, respectively. If contaminated aquatic organisms alone are
consumed, excluding the consumption of water, the water
concentration should be less than 1.75 x 10~4 to keep the
increased lifetime cancer risk below 10-5. Available data show
that adverse effects on aquatic life occur at concentrations
higher than those cited for human health risks.
A few studies have been made regarding the behavior of arsenic in
a POTW. One EPA survey of nine POTW facilities reported influent
concentrations ranging from 0.0005 to 0.693 mg/1; effluents from
three POTW facilities having biological treatment contained
0.0004 to 0.01 mg/1; two POTW facilities showed arsenic removal
efficiencies of 50 and 71 percent in biological treatment.
Inhibition of treatment processes by sodium arsenate is reported
to occur at 0.1 mg/1 in activated sludge, and 1.6 mg/1 in
anaerobic digestion processes. In another study based on data
from 60 POTW facilities, arsenic in sludge ranged from 1.6 to
65.6 mg/kg and the median value was 7.8 mg/kg. Arsenic in sludge
spread on cropland may be taken up by plants grown on that land.
Edible plants can take up arsenic, but normally their growth is
inhibited before the plants are ready for harvest.
Asbestos (116). Asbestos is a generic term used to describe a
group of hydrated mineral silicates that can appear in a fibrous
crystal form (asbestiform) and, when crushed, can separate into
flexible fibers. The types of asbestos presently used
commercially fall into two mineral groups; the serpentine and
amphibole groups. Asbestos is mineralogically stable and is not
prone to significant chemical or biological degradation in the
aquatic environment. In 1978, the total consumption of asbestos
in the U.S. was 583,000 metric tons. Asbestos is an excellent
insulating material and is used in a wide variety of products.
Based on 1975 figures, the total annual identifiable asbestos
emissions are estimated at 243,527 metric tons. Land discharges
account for 98.3 percent of the emissions, air discharges account
for 1.5 percent, and water discharges account for 0.2 percent.
Asbestos has been found to produce significant incidence of
disease among workers occupationally exposed in mining and
milling, in manufacturing, and in the use of materials containing
the fiber. The predominant type of exposure has been inhalation,
although some asbestos may be swallowed directly or ingested
after being expectorated from the respiratory tract.
Noncancerous asbestos has been found among people directly
exposed to high levels of asbestos as a result of excessive work
exposure; much less frequently, among those with lesser exposures
although there is extensive evidence of pulmonary disease among
people exposed to airborne asbestos. There is little evidence of
disease among people exposed to waterborne fibers.
Asbestos at the concentrations currently found in the aquatic
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
environment does not appear to exert toxic effects on aquatic
organisms. For the maximum protection of human health from the
potential carcinogenic effects of exposure to asbestos through
ingestion of water and contaminated aquatic organisms, the
ambient water concentration should be zero based on the non-
threshold assumption of this substance. However, zero level may
not be attainable at the present time. Therefore, levels which
may result in incremental increase of cancer risk over the life
time are estimated at 10 , 10 , and 10 The corresponding
recommended criteria are 300,000 fibers/1, 30,000 fibers/1, and
3,000 fibers/1.
The available data indicate that technologies used at POTW for
reducing levels of total suspended solids in wastewater also
provide a concomitant reduction in asbestos levels. Asbestos
removal efficiencies ranging from 80 percent to greater than 99
percent have been reported following sedimentation of wastewater.
Filtration and sedimentation with chemical addition (i.e., lime
and polymer) have achieved even greater percentage removals.
Beryllium (117) . Beryllium is a dark gray metal of the alkaline
earth family. It is relatively rare, but because of its unique
properties finds widespread use as an alloying element,
especially for hardening copper which is used in springs,
electrical contacts and non-sparking tools. World production is
reported to be in the range of 250 tons annually. However, much
more reaches the environment as emissions from coal burning
operations. Analysis of coal indicates an average beryllium
content of 3 ppm and 0.1 to 1.0 percent in coal ash or fly ash.
The principal ores are beryl (3BeO¦AI2O3 *63102) and bertrandite
(Be4Si207(OH)2)• Only two industrial facilities produce
beryllium in the U.S. because of 1imited demand and the highly
toxic character. About two-thirds of the annual production goes
into alloys, 20 percent into heat sinks, and 10 percent into
beryllium oxide (BeO) ceramic products.
Beryllium has a specific gravity of 1.846, making it the lightest
metal with a high melting point (1,350° C). Beryllium alloys
are corrosion resistant, but the metal corrodes in aqueous
environments. Most common beryllium compounds are soluble in
water, at least to the extent necessary to produce a toxic
concentration of beryllium ions.
Most data on toxicity of beryllium is for inhalation of beryllium
oxide dust. Some studies on orally administered beryllium in
laboratory animals have been reported. Despite the large number
of studies implicating beryllium as a carcinogen, there is no
recorded instance of cancer being produced by ingestion.
However, a recently convened panel cf uninvolved experts
concluded that epidemiologic evidence is suggestive that
beryllium is a carcinogen in man.
In the aquatic environment, beryllium is chronically toxic to
aquatic organisms at 0.0053 mg/1. Water softness has a large
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
effect on beryllium toxicity to fish. In soft water, beryllium
is reportedly 100 times as toxic as in hard water.
For the maximum protection of human health from the potential
carcinogenic effects of exposure to beryllium through ingestion
of water and contaminated aquatic organisms the ambient water
concentration is zero. Concentrations of beryllium estimated to
result in additional lifetime cancer risk levels of 10" , 10" ,
and 10"5 are 0.00000068 mg/1, 0.0000068 mg/1, and 0.000068 mg/1,
respectively. If contaminated aquatic grganisms alone are
consumed excluding the consumption of water, the concentration
should be less than_0.00115 mg/1 to keep the increased lifetime
cancer risk below 10 ,
Information on the behavior of beryllium in a POTW is scarce.
Because beryllium hydroxide is insoluble in water, most beryllium
entering a POTW will probably be in the form of suspended solids.
As a result, most of the beryllium will settle and be removed
with sludge. However, beryllium has been shown to inhibit
several enzyme systems, to interfere with DNA metabolism in
liver, and to induce chromosomal and mitotic abnormalities. This
interference in cellular processes may extend to interfere with
biological treatment processes. The concentration and effects of
beryllium in sludge which could be applied to cropland have not
been studied.
Cadmium (118). Cadmium is a relatively rare metallic element
that Is seldom found in sufficient quantities in a pure state to
warrant mining or extraction from the earth's surface. It is
found in trace amounts of about 1 ppm throughout the earth's
crust. Cadmium is, however, a valuable by-product of zinc
production.
Cadmium is used primarily as an electroplated metal and is found
as an impurity in the secondary refining of zinc, lead, and
copper.
Cadmium is an extremely dangerous
progressive chronic poisoning in
other organisms. The metal is not
cumulative toxicant, causing
mammals, fish, and probably
excreted.
Toxic effects of cadmium on man have been reported from through-
out the world. Cadmium may be a factor in the development of
such human pathological conditions as kidney disease, testicular
tumors, hypertension, arteriosclerosis, growth inhibition,
chronic disease of old age, and cancer. Cadmium is normally
ingested by humans through food and water as well as by breathing
air contaminated by cadmium dust. Cadmium is cumulative in the
liver, kidney, pancreas, and thyroid of humans and other animals.
A severe bone and kidney syndrome known as ita-itai disease has
been documented in Japan as caused by cadmium ingestion via
drinking water and contaminated irrigation water. Ingestion of
as little as 0.6 mg/day has produced the disease. Cadmium acts
synergistically with other metals. Copper and zinc substantially
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
increase its toxicity.
Cadmium is concentrated by marine organisms, particularly
mollusks, which accumulate cadmium in calcareous tissues and in
the viscera. A concentration factor of 1,000 for cadmium in fish
muscle has been reported, as have concentration factors of 3,000
in marine plants and up to 29,600 in certain marine animals. The
eggs and larvae of fish are apparently more sensitive than adult
fish to poisoning by cadmium, and crustaceans appear to be more
sensitive than fish eggs and larvae.
For the protection of human health from the toxic properties of
cadmium ingested through water and through contaminated aquatic
organisms, the ambient water criterion is determined to be 0.010
mg/1. Available data show that adverse effects on aquatic life
occur at concentrations in the same range as those cited for
human health, and they are highly dependent on water hardness.
Cadmium is not destroyed when it is introduced into a POTW, and
will either pass through to the POTW effluent or be incorporated
into the POTW sludge. In addition, it can interfere with the
POTW treatment process.
In a study of 189 POTW facilities, 75 percent of the primary
plants, 57 percent of the trickling filter plants, 66 percent of
the activated sludge plants, and 62 percent of the biological
plants allowed over 90 percent of the influent cadmium to pass
through to the POTW effluent. Only two of the 189 POTW
facilities allowed less than 20 percent pass-through, and none
less than 10 percent pass-through. POTW effluent concentrations
ranged from 0.001 to 1.97 mg/1 (mean 0.028 mg/1, standard
deviation 0.167 mg/1).
Cadmium not passed through the POTW will be retained in the
sludge where it is likely to build up in concentration. Cadmium
contamination of sewage sludge limits its use on land since it
increases the level of cadmium in the soil. Data show that
cadmium can be incorporated into crops, including vegetables and
grains, from contaminated soils. Since the crops themselves show
no adverse effects from soils with levels up to 100 mg/kg
cadmium, these contaminated crops could have a significant impact
on human health. Two Federal agencies have already recognized
the potential adverse human health effects posed by the use of
sludge on cropland. The FDA recommends that sludge containing
over 30 mg/kg of cadmium should not be used on agricultural land.
Sewage sludge contains 3 to 300 mg/kg (dry basis) of cadmium
(mean = 10 mg/kg, median = 16 mg/kg). The USDA also recommends
placing limits on the total cadmium from sludge that may be
applied to land.
Chromium (119). Chromium is an elemental metal usually found as
a chromite (FeO * Cr 2O3). The metal is normally produced by
reducing the oxide with aluminum. A significant proportion of
the chromium used is in the form of compounds such as sodium
dichromate (Na2Cr04), and chromic acid (Cr03) - both are
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
hexavalent chromium compounds.
Chromium is found as an alloying component of many steels and its
compounds are used in electroplating baths and as corrosion
inhibi tors for closed water circulation systems.
The two chromium forms most frequently found in industry
wastewaters are hexavalent and trivalent chromium. Hexavalent
chromium is the form used for metal treatments. Some of it is
reduced to trivalent chromium as part of the process reaction.
The raw wastewater containing both valence states is usually
treated first to reduce remaining hexavalent to trivalent
chromium, and second to precipitate the trivalent form as the
hydroxide. The hexavalent form is not removed by lime treatment.
Chromium, in its various valence states, is hazardous to man. It
can produce lung tumors when inhaled, and induces skin
sensitizations. Large doses of chromates have corrosive effects
on the intestinal tract and can cause inflammation of the
kidneys. Hexavalent chromium is a known human carcinogen. Levels
of chromate ions that show no effect in man appear to be so low
as to prohibit determination, to date.
The toxicity of chromium salts to fish and other aquatic life
varies widely with the species, temperature, pH, valence of the
chromium, and synergistic or antagonistic effects, especially the
effect of water hardness. Studies have shown that trivalent
chromium is more toxic to fish of some types than is hexavalent
chromium. Hexavalent chromium retards growth of one fish species
at 0.0002 mg/1. Fish food organisms and other lower forms of
aquatic life are extremely sensitive to chromium. Therefore,
both hexavalent and trivalent chromium must be considered harmful
to particular fish or organisms.
For the protection of human health from the toxic properties of
chromium (except hexavalent chromium) ingested through water and
contaminated aquat ic organisms, the ambient water quality
criterion is 170 mg/1. If contaminated aquatic organisms alone
are consumed excluding the consumption of water, the ambient
water cr iter ion for trivalent chromium is 3,443 mg/1. The
ambient water quality criter ion for hexavalent chromium is
recommended to be identical to the existing drinking water
standard for total chromium which is 0.050 mg/1.
Chromium is not destroyed when treated by a POTW (although the
oxidation state may change), and will either pass through to the
POTW effluent or be incorporated into the POTW sludge. Both
oxidation states can cause POTW treatment inhibition and can also
limit the usefulness of municipal sludge.
Influent concentrations of chromium to POTW facilities have been
observed by EPA to range from 0.005 to 14.0 mg/1, with a median
concentration of 0.1 mg/1. The efficiencies for removal of
chromium by the activated sludge process can vary greatly,
depending on chromium concentration in the influent, and other
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
operating conditions at the POTW. Chelation of chromium by
organic matter and dissolution due to the presence of carbonates
can cause deviations from the predicted behavior in treatment
systems.
The systematic presence of chromium compounds will halt
nitrification in a POTW for short periods, and most of the
chromium will be retained in the sludge solids. Hexavalent
chromium has been reported to severely affect the nitrification
process, but trivalent chromium has little or no toxicity to
activated sludge, except at high concentrations. The presence of
iron, copper, and low pH will increase the toxicity of chromium
in a POTW by releasing the chromium into solution to be ingested
by microorganisms in the POTW.
The amount of chromium which passes through to the POTW effluent
depends on the type of treatment processes used by the POTW. In
a study of 240 POTW facilities, 56 percent of the primary plants
allowed more than 80 percent pass-through to POTW effluent. More
advanced treatment results in less pass-through. POTW effluent
concentrations ranged from 0.003 to 3.2 mg/1 total chromium (mean
= 0.197, standard deviation = 0.48), and from 0.002 to 0.1 mg/1
hexavalent chromium (mean = 0.017, standard deviation = 0.020).
Chromium not passed through the POTW will be retained in the
sludge, where it is likely to build up in concentration. Sludge
concentrations of total chromium of over 20,000 mg/kg (dry basis)
have been observed. Disposal of sludges containing very high
concentrations of trivalent chromium can potentially cause
problems in uncontrolled landfills. Incineration, or similar
destructive oxidation processes, can produce hexavalent chromium
from lower valence states. Hexavalent chromium is potentially
more toxic than trivalent chromium. In cases where high rates of
chrome sludge application on land are used, distinct growth
inhibition and plant tissue uptake have been noted.
Pretreatment of discharges substantially reduces the
concentration of chromium in sludge. In Buffalo, New York,
pretreatment of electroplating waste resulted in a decrease in
chromium concentrations in POTW sludge from 2,510 to 1,040 mg/kg.
A similar reduction occurred in Grand Rapids, Michigan, POTW
facilities where the chromium concentration in sludge decreased
from 11,000 to 2,700 mg/kg when pretreatment was made a
requirement.
Copper (120) . Copper is a metallic element that sometimes is
found free, as the native metal, and is also found in minerals
such as cuprite (CU2O, maiechite [CUCO3.Cu(OH)2], azurite
[2CUCO3.Cu(OH)2], chalccpyrite (CuFeS2), and bornite (CuSFeS4) .
Copper is obtained from these ores by smelting, leaching, and
electrolysis. It is used in the plating, electrical, plumbing,
and heating equipment industries, as well as in insecticides and
fungicides .
Traces of copper are found in all forms of plant and animal life,
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
and the metal is an essential trace element for nutrition. Copper
is not considered to be a cumulative systemic poison for humans
as it is readily excreted by the body, but it can cause symptoms
of gastroenteritis, with nausea and intestinal irritations, as
relatively low dosages. The limiting factor in domestic water
supplies is taste. To prevent this adverse organoleptic effect
of copper in water, a criterion of 1 mg/1 has been established.
The toxicity of copper to aquatic organisms varies significantly,
not only with the species, but also with the physical and
chemical characteristics of the water including temperature,
hardness, turbidity, and carbon dioxide content. In hard water,
the toxicity of copper salts may be reduced by the precipitation
of copper carbonate or other insoluble compounds. The sulfates
of copper and zinc, and of copper and calcium are synergistic in
their toxic effect on fish.
Relatively high concentrations of copper may be tolerated by
adult fish for short periods of time? the critical effect of
copper appears to be its higher toxicity to young or juvenile
fish. Concentrations of 0.02 to 0.03 mg/1 have proved fatal to
some common fish species. In general, the salmonoids are very
sensitive and the sunfishes are less sensitive to copper.
The recommended criterion to protect freshwater aquatic life is
0.0056 mg/1 as a 24-hour average, and 0.012 mg/1 maximum
concent rat ion at a hardness of 50 mg/1 CaCOj. For total
recoverable copper, the criterion to protect freshwater aquatic
life is 0.0056 mg/1 as a 24-hour average.
Copper salts cause undesirable color reactions in the food
industry and cause pitting when deposited on some other metals
such as aluminum and galvanized steel. To control undesirable
taste and odor quality of ambient water due to the organoleptic
properties of copper, the estimated level is 1.0 mg/1 for total
recoverable copper.
Irrigation water containing more than minute quantities of copper
can be detrimental to certain crops. Copper appears in all
soils, and its concentration ranges from 10 to 80 ppm. In soils,
copper occurs in association with hydrous oxides of manganese and
iron, and also as soluble and insoluble complexes with organic
matter. Copper is essential to the life of plants, and the
normal range of concentration in plant tissue is from 5 to 20
ppm. Copper concentrations in plants normally do not build up to
high levels when toxicity occurs. For example, the
concentrations of copper in snapbean leaves and pods was less
than 50 and 20 mg/kg, respectively, under condi ticns of severe
copper toxicity. Even under conditions of copper toxicity, most
of the excess copper accumulates in the roots; very little is
moved to the aerial part of the plant.
Copper is not destroyed when treated by a POTW, and will either
pass through to the POTW effluent or be retained in the POTW
sludge. It can interfere with the POTW treatment processes and
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
can limit the usefulness of municipal sludge.
The influent concentration of copper to a POTW has been observed
by the EPA to range from 0.01 to 1.97 mg/1, with a median
concentration of 0.12 mg/1. The copper that is removed from the
influent stream of a POTW is absorbed on the sludge or appears in
the sludge as the hydroxide of the metal. Bench-scale pilot
studies have shown that from about 25 percent to 75 percent of
the copper passing through the activated sludge process remains
in solution in the final effluent. Pour-hour slug dosages of
copper sulfate in concentrations exceeding 50 mg/1 were reported
to have severe effects on the removal efficiency of an
unacclimated system, with the system returning to normal in about
100 hours. Slug dosages of copper in the form of copper cyanide
were observed to have much more severe effects on the activated
sludge system, but the total system returned to normal in 24
hours.
In a recent study of 268 POTW facilities, the median pass-through
was over 80 percent for primary plants and 40 to 50 percent for
trickling filter, activated sludge, and biological treatment
plants. POTW effluent concentrations of copper ranged from 0.003
to 1.8 mg/1 (mean = 0.126, standard deviation = 0.242).
Copper which does not pass through the POTW will be retained in
the sludge where it will build up in concentration. The presence
of excessive levels of copper in sludge may limit its use on
cropland. Sewage sludge contains up to 16,000 mg/kg of copper,
with 730 mg/kg as the mean value. These concentrations are
significantly greater than those normally found in soil which
usually range from 18 to 80 mg/kg. Experimental data indicate
that when dried sludge is spread over tillable land, the copper
tends to remain in place down to the depth of the tillage, except
for copper which is taken up by plants grown in the soil. Recent
investigation has shown that the extractable copper content of
sludge-treated soil decreased with time, which suggests a
reversion of copper to less soluble forms was occurring.
Cyanide (121). Cyanides are among the most toxic of pollutants
commonly observed in industrial wastewaters. Introduction of
cyanide into industrial processes is usually by dissolution of
potassium cyanide (KCN) or sodium cyanide (NaCN) in process
waters. However, hydrogen cyanide (HCN), formed when the above
salts are dissolved in water, is probably the most acutely lethal
compound.
The relationship of pH to hydrogen cyanide formation is very
important. As pK is lowered to below 7, more than 99 percent of
the cyanide is present as HCN and less than 1 percent as cyanide
ions. Thus, at neutral pH, that of most living organisms, the
more toxic form of cyanide prevails.
Cyanide ions combine with numerous heavy metal ions to form
complexes. The complexes are in equilibrium with HCN. Thus, the
stability of the metal-cyanide complex and the pH determine the
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
concentration of HCN. Stability of the metal-cyanide anion
complexes is extremely variable. Those formed with zinc, copper,
and cadmium are not stable - they rapidly dissociate, with
production of HCN, in near neutral or acid waters. Some of the
complexes are extremely stable. Cobaltocyanide is very resistant
to acid distillation in the laboratory. Iron cyanide complexes
are also stable, but undergo photodecomposition to give HCN upon
exposure to sunlight. Synergistic effects have been demonstrated
for the metal cyanide complexes making zinc, copper, and cadmium
cyanides more toxic than an equal concentration of sodium
cyanide.
The toxic mechanism of cyanide is essentially an inhibition of
oxygen metabolism (i.e., rendering the tissues incapable of
exchanging oxygen). The cyanogen compounds are true noncumulative
protoplasmic poisons. They arrest the activity of all forms of
animal life. Cyanide shows a very specific type of toxic action.
It inhibits the cytochrome oxidase system. This system is the
one which facilitates electron transfer from reduced metabolites
to molecular oxygen. The human body can convert cyanide to a
non-toxic thiocyanate and eliminate it. However, if the quantity
of cyanide ingested is too great at one time, the inhibition of
oxygen utilization proves fatal before the detoxifying reaction
reduces the cyanide concentration to a safe level.
Cyanides are more toxic to fish than to lower forms of aquatic
organisms such as midge larvae, crustaceans, and mussels.
Toxicity to fish is a function of chemical form and
concentration, and is influenced by the rate of metabolism
(temperature), the level of dissolved oxygen, and pH. In
laboratory studies, free cyanide concentrations ranging from 0.05
to O.lg mg/1 have been proven to be fatal to sensitive fish
species including trout, bluegi11, and fathead minnows. Levels
above 0.2 mg/1 are rapidly fatal to most fish species. Long-term
sublethal concentrations of cyanide as low as 0.01 mg/1 have been
shown to affect the ability of fish to function normally (e.g.,
reproduce, grow, and swim).
For the protection of human health' from the toxic properties of
cyanide ingested through water and through contaminated aquatic
organisms, the ambient water quality criterion is determined to
be 0.200 mg/1.
Persistence of cyanide in water is highly variable and depends
upon the chemical form of cyanide in the water, the concentration
of cyanide, and the nature of other constituents. Cyanide may be
destroyed by strong oxidizing agents such as permanganate and
chlorine. Chlorine is commonly used to oxidize strong cyanide
solutions. Carbon dioxide and nitrogen are the products of
complete oxidation. But if the reaction is not complete, the
very toxic compound, cyanogen chloride, may remain in the
treatment system and subsequently be released to the environment.
Partial chlorination may occur as part of a POTW treatment, or
during the disinfection treatment of surface water for drinking
water preparation.
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Cyanides can interfere with treatment processes in a POTW, or
pass through to ambient waters. At low concentrations and with
acclimated microflora, cyanide may be decomposed by
microorganisms in anaerobic and aerobic environments or waste
treatment systems. However, data indicate that much of the
cyanide introduced passes through to the POTW effluent. The mean
pass-through of 14 biological plants was 71 percent. In a recent
study of 41 POTW facilities the effluent concentrations ranged
from 0.002 to 100 rtig/1 (mean = 2.518, standard deviation = 15.6).
Cyanide also enhances the toxicity of metals commonly found in
POTW effluents, including the toxic pollutants cadmium, zinc, and
copper.
Data for Grand Rapids, Michigan, showed a significant decline in
cyanide concentrations downstream from the POTW after
pretreatment regulations were put in force. Concentrations fell
from 0.66 mg/1 before, to 0.01 mg/1 after pretreatment was
required.
Lead (122). Lead is a soft, malleable, ductile, blueish-gray,
metallic element, usually obtained from the mineral galena (lead
sulfide, PbS), anglesite (lead sulfate, PbSO<}) , or cerussite
(lead carbonate, PbC03). Because it is usually associated with
minerals of zinc, silver, copper, gold, cadmium, antimony, and
arsenic, special purification methods are frequently used before
and after extraction of the metal from the ore concentrate by
smelting.
Lead is widely used for its corrosion resistance, sound and
vibration absorption, low melting point (solders), and relatively
high imperviousness to various forms of radiation. Small amounts
of copper, antimony and other metals can be alloyed with lead to
achieve greater hardness, stiffness, or corrosion resistance than
is afforded by the pure metal. Lead compounds are used in glazes
and paints. About one third of U.S. lead consumption goes into
storage batteries. About half of U.S. lead consumption is from
secondary lead recovery. U.S. consumption of lead is in the
range of one million tons annually.
Lead ingested by humans produces a variety of toxic effects
including impaired reproductive ability, disturbances in blood
chemistry, neurological disorders, kidney damage, and adverse
cardiovascular effects. Exposure to lead in the diet results in
permanent increase in lead levels in the body. Most of the lead
entering the body eventually becomes localized in the bones where
it accumulates. Lead is a carcinogen or cocarcinogen in some
species of experimental animals. Lead is teratogenic in
experimental animals. Mutagenicity data are not available for
lead.
The ambient water quality criterion for lead is recommended to be
identical to the existing drinking water standard which is 0.050
mg/1. Available data show that adverse effects on aquatic life
occur at concentrations as low as 7.5 x 10-4 mg/1 of total
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
recoverable lead as a 24-hour average with a water hardness of 50
mg/1 as CaC03.
Lead is not destroyed in a POTW, but is passed through to the
effluent or retained in the POTW sludge; it can interfere with
POTW treatment processes and can limit the usefulness of POTW
sludge for application to agricultural croplands. Threshold
concentration for inhibition of the activated sludge process is
0.1 mg/1, and for the nitrification process is 0.5 mg/1. In a
study of 214 POTW facilities, median pass-through values were
over 80 percent for primary plants and over 60 percent for
trickling filter, activated sludge, and biological process
plants. Lead concentration in POTW effluents ranged from 0.003
to 1.8 mg/1 (mean = 0.106 mg/1, standard deviation = 0.222).
Application of lead-containing sludge to cropland should not lead
to uptake by crops under most conditions because normally lead is
strongly bound by soil. However, under the unusual condition of
low pH (less than 5.5) and low concentrations of labile
phosphorus, lead solubility is increased and plants can
accumulate lead.
Mercury (123) ¦ Mercury is an elemental metal rarely found in
nature as the free metal. Mercury is unique among metals as it
remains a liquid down to about 39 degrees below zero. it is
relatively inert chemically and is insoluble in water. The
principal ore is cinnabar (HgS).
Mercury is used industrially as the metal and as mercurous and
mercuric salts and compounds. Mercury is used in several types
of batteries. Mercury released to the aqueous environment is
subject to biomethylation - conversion to the extremely toxic
methyl mercury.
Mercury can be introduced into the body through the skin and the
respiratory system as the elemental vapor. Mercuric salts are
highly toxic to humans and can be absorbed through the
gastrointestinal tract. Fatal doses can vary from 1 to 30 grams.
Chronic toxicity of methyl mercury is evidenced primarily by
neurological symptoms. Some mercuric salts cause death by kidney
failure.
Mercuric salts are extremely toxic to fish and other aquatic
life. Mercuric chloride is more lethal than copper, hexavalent
chromium, zinc, nickel, and lead towards fish and aquatic life.
In the food cycle, algae containing mercury up to 100 times the
concentration in the surrounding sea water are eaten by fish
which fur the r concentrate the mercury. Predators that eat the
fish in turn concentrate the mercury even further.
For the protection of human health from the toxic properties of
mercury ingested through water and through contaminated aquatic
organisms, the ambient water criterion is determined to be 0.0002
mg/1.
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Mercury is not destroyed when treated by a POTW, and will either
pass through to the POTW effluent or be incorporated into the
POTW sludge. At low concentrations it may reduce POTW removal
efficiencies, and at high concentrations it may upset the POTW
operation,
The influent concentrations of mercury to a POTW have been
observed by the EPA to range from 0.002 to 0.24 mg/1, with a
median concentration of 0,001 mg/1. Mercury has been reported in
the literature to have inhibiting effects upon an activated
sludge POTW at levels as low as 0.1 mg/1. At 5 mg/1 of mercury
losses of COD removal efficiency of 14 to 40 percent have been
reported, while at 10 mg/1, loss of removal of 59 percent has been
reported. Upset of an activated sludge POTW is reported in the
literature to occur near 200 mg/1. The anaerobic digestion
process is much less affected by the presence of mercury, with
inhibitory effects being reported at 1,365 mg/1.
In a study of 22 POTW facilities having secondary treatment, the
range of removal of mercury from the influent to the POTW ranged
from 4 to 99 percent with median removal of 41 percent. Thus
significant pass-through of mercury may occur.
In sludges, mercury content may be high if industrial sources of
mercury contamination are present. Little is known about the
form in which mercury occurs in sludge. Mercury may undergo
biological methylation in sediments, but no methylation has been
observed in soils, mud, or sewage sludge.
The mercury content of soils not receiving additions of POTW
sewage sludge lie in the range from 0.01 to 0.5 mg/kg. In soils
receiving POTW sludges for protracted periods, the concentration
of mercury has been observed to approach 1.0 mg/kg. In the soil,
mercury enters into reactions with the exchange complex of clay
and organic fractions, forming both ionic and covalent bonds.
Chemical and microbiological degradation of mercurials can take
place side by side in the soil, and the products - ionic or
molecular - are retained by organic matter and clay or may be
volatilized if gaseous. Because of the high affinity between
mercury and the solid soil surfaces, mercury persists in the
upper layer of the soil.
Mercury can enter plants through the roots, it can readily move
to other parts of the plant, and it has been reported to cause
injury to plants. In many plants mercury concentrations range
from 0.01 to 0.20 mg/kg, but when plants are supplied with high
levels of mercury, these concentrations can exceed 0.5 mg/kg.
Bioconcentration occurs in animals ingesting mercury in food.
Nickel j_124). Nickel is seldom found in nature as the pure
elemental metal. It is a relatively plentiful element and is
widely distributed throughout the earth's crust. It occurs in
marine organisms and is found in the oceans. The chief
commercial ores for nickel are pentlandite {(Fe,Ni)9S8], and a
lateritic ore consisting of hydrated nickel-iron-magnesium
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silicate.
Nickel has many and varied uses. It is used in alloys and as the
pure metal. Nickel salts are used for electroplating baths.
The toxicity of nickel to man is thought to be very low, and
systemic poisoning of human beings by nickel or nickel salts is
almost unknown. In non-human mammals nickel acts to inhibit
insulin release, depress growth, and reduce cholesterol. A high
incidence of cancer of the lung and nose has been reported in
humans engaged in the refining of nickel.
Nickel salts can kill fish at very low concentrations. However,
nickel has been found to be less toxic to some fish than copper,
zinc, and iron. Nickel is present in coastal and open ocean
water at concentrations in the range of 0.0001 to 0.006 mg/1
although the most common values are 0.002 to 0.003 mg/1. Marine
animals contain up to 0.4 mg/1 and marine plants contain up to 3
mg/1. Higher nickel concentrations have been reported to cause
reduction in photosynthetic activity of the giant kelp. A low
concentration was found to kill oyster eggs.
For the protection of human health based on the toxic properties
of nickel ingested through water and through contaminated aquatic
organisms, the ambient water criterion is determined to be 0.0134
mg/1. If contaminated aquatic organisms are consumed, excluding
consumption of water, the ambient water criterion is determined
to be 0.100 mg/1. Available data show that adverse effects on
aquatic life occur for total recoverable nickel concentrations as
low as 0.0071 mg/1 as a 24-hour average.
Nickel is not destroyed when treated in a POTW, but will either
pass through to the POTW effluent or be retained in the POTW
sludge. It can interfere with POTW treatment processes and can
also limit the usefulness of municipal sludge.
Nickel salts have caused inhibition of the biochemical oxidation
of sewage in a POTW. In a pilot plant, slug doses of nickel
significantly reduced normal treatment efficiencies for a few
hours, but the plant acclimated itself somewhat to the slug
dosage and appeared to achieve normal treatment efficiencies
within 40 hours. It has been reported that the anaerobic
digestion process is inhibited only by high concentrations of
nickel, while a low concentration of nickel inhibits the
nitrification process.
The influent concentration of nickel to a POTW has been observed
by the EPA to range from 0.01 to 3.19 mg/1, with a median of 0.33
mg/1. In a study of 190 POTW facilities, nickel pass-through was
greater than 90 percent for 82 percent of the primary plants.
Median pass-through for trickling filter, activated sludge, and
biological process plants was greater than 80 percent. POTW
effluent concentrations ranged from 0.002 to 40 mg/1 (mean
0.410, standard deviation = 3.279).
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Nickel not passed through the POTW will be incorporated into the
sludge. In a recent two-year study of eight cities, four of the
cities had median nickel concentrations of over 350 mg/kg, and
two were over 1,000 mg/kg. The maximum nickel concentration
observed was 4,010 mg/kg.
Nickel is found in nearly all soils, plants, and waters. Nickel
has no known essential function in plants. In soils, nickel
typically is found in the range from 10 to 100 mg/kg. Various
environmental exposures to nickel appear to correlate with
increased incidence of tumors in man. For example, cancer in the
maxillary antrum of snuff users may result from using plant
materials grown on soil high in nickel.
Nickel toxicity may develop in plants from application of sewage
sludge on acid soils. Nickel has caused reduction of yields for
a variety of crops including oats, mustard, turnips, and cabbage.
In one stu nickel decreased the yields of oats significantly
at 100 mg/kg.
Whether nickel exerts a toxic effect on plants depends on several
soil factors, the amount of nickel applied, and the contents of
other metals in the sludge. Unlike copper and zinc, which are
more available from inorganic sources than from sludge, nickel
uptake by plants seems to be promoted by the presence of the
organic matter in sludge. Soil treatments, such as liming,
reduce the solubility of nickel. Toxicitry of nickel to plants is
enhanced in acidic soils.
Selenium (125). Selenium is a non-metallic element existing in
several allotropic forms. Gray selenium, which has a metallic
appearance, is the stable form at ordinary temperatures and melts
at 220°C. Selenium is a major component of 38 minerals and a
minor component of 37 others found in various parts of the world.
Most selenium is obtained as a by-product of precious metals
recovery from electrolytic copper refinery slimes. U.S. annual
production at one time reached one million pounds.
Principal uses of selenium are in semi-conductors, pigments,
decoloring of glass, and metallurgy. It also is used to produce
ruby glass used in signal lights. Several selenium compounds are
important oxidizing agents in the synthesis of organic chemicals
and drug products.
While results of some studies suggest that selenium may be an
essential element in human nutrition, the toxic effects of
selenium in humans are well established. Lassitude, loss of
hair, discoloration and loss of fingernails are symptoms of
selenium poisoning. In a fatal case of ingestion or a larger
dose of selenium acid, peripheral vascular collapse, pulmonary
edema, and coma occurred. Selenium produces mutagenic and
teratogenic effects, but it has not been established as
exhibiting carcinogenic activity.
For the protection of human health from the toxic properties of
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selenium ingested through water and through contaminated aquatic
organisms, the ambient water criterion is determined to be 0.010
mg/1, (i.e., the same as the drinking water standard). Available
data show that adverse effects on aquatic life occur at
concentrations higher than that cited for human toxicity.
Very few data are available regarding the behavior of selenium in
a POTW. One EPA survey of 103 POTW facilities revealed one POTW
using biological treatment and having selenium in the influent.
Influent concentration was 0.0025 mg/1, and effluent
concentration was 0.0016 mg/1, giving a removal of 37 percent.
It is not known to be inhibitory to POTW processes. In another
study, sludge from POTW facilities in 16 cities was found to
contain from 1.8 to 8.7 mg/kg selenium, compared to 0,01 to 2
mg/kg in untreated soil. These concentrations of selenium in
sludge present a potential hazard for humans or other mammals
eating crops grown on soil treated with selenium-containing sludge.
Silver (126). Silver is a soft lustrous white metal that is
insoluble in water and alkali. In nature, silver is found in the
elemental state (native silver) and combined in ores such as
argentite (Ag2S), horn silver (AgCl), proustite (Ag3AsS3), and
pyrargyrite (AgjSbSj). Silver is used extensively in several
industries, among them electroplating.
Metallic silver is not considered to be toxic, but most of its
salts are toxic to a large number of organisms. Upon ingestion
by humans, many silver salts are absorbed in the circulatory
system and deposited in various body tissues, resulting in
generalized or sometimes localized gray pigmentation of the skin
and mucous membranes known as argyria. There is no known method
for removing silver from the tissues once it is deposited, and
the effect is cumulative.
Silver is recognized as a bactericide and doses from 0.000001 to
0.0005 mg/1 have been reported as sufficient to sterilize water.
The criterion for ambient water to protect human health from the
toxic properties of silver ingested through water and through
contaminated aquatic organisms is 0.010 mg/1.
The chronic toxic effects of silver on the aquatic environment
have not been given as much attention as many other heavy metals.
Data from existing literature support the fact that silver is
very toxic to aquatic organisms. Despite the fact that silver is
nearly the most toxic of the heavy metals, there are insufficient
data to adequately evaluate even the effects of hardness on
silver toxicity. There are no data available on the toxicity of
different forms of silver.
There is no available literature on the incidental removal of
silver by a POTW. An incidental removal of about 50 percent is
assumed as being representative. This is the highest average
incidental removal of any metal for which data are available.
(Copper has been indicated to have a median incidental removal
rate of 49 percent.)
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Bioaccumulation and concentration of silver from sewage sludge
has not been studied to any great degree. There is some
indication that silver could be bioaccumulated in mushrooms to
the extent that there could be adverse physiological effects on
humans if they consumed large quantities of mushrooms grown in
silver-enriched soil. The effect, however, would tend to be
unpleasant rather than fatal.
There are little summary data available on the quantity of silver
discharged to a POTW. Presumably there would be a tendency to
limit its discharge from a manufacturing facility because of its
high intrinsic value.
Thallium (127) . Thallium is a soft, silver-white, dense,
malleable metal. Five major minerals contain 15 to 85 percent
thallium, but they are not of commercial importance because the
metal is produced in sufficient quantity as a by-product of lead-
zinc smelting of sulfide ores. Thallium melts at 304°C. U.S.
annual production of thallium and its compounds is estimated to
be 1,500 pounds.
Industrial uses of thallium include the manufacture of alloys,
electronic devices and special glass. Thallium catalysts are
used for industrial organic syntheses.
Acute thallium poisoning in humans has been widely described.
Gastrointestinal pains and diarrhea are followed by abnormal
sensation in the legs and arms, dizziness, and, later, loss of
hair. The central nervous system is also affected. Somnolence,
delirium or coma may occur. Studies on the teratogenicity of
thallium appear inconclusive; no studies on mutagenicity were
found; and no published reports on carcinogenicity of thallium
were found.
For the protection of human health from the toxic properties of
thallium ingested through water and contaminated aquatic
organisms, the ambient water criterion is 0.004 mg/1.
No reports were found regarding the behavior of thallium in a
POTW. It will not be degraded; therefore, it must pass through
to the effluent or be removed with the sludge. However, since
the sulfide (T1S) is very insoluble, if appreciable sulfide is
present, dissolved thallium in the influent to a POTW may be
precipitated into the sludge. Subsequent use of sludge bearing
thallium compounds as a soil amendment to crop bearing soils may
result in uptake of this element by food plants. Several leafy
garden crops (cabbage, lettuce, leek, and endive) exhibit
relatively higher concentrations of thallium than other foods
such as meat.
Z inc (128)¦ Zinc occurs abundantly in the earth's crust,
concentrated in ores. It is readily refined into the pure,
stable, silver-white metal. In addition to its use in alloys,
zinc is used as a protective coating on steel. It is applied by
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hot dipping (i.e., dipping the steel in molten zinc) or by
electroplating.
Zinc can have an adverse effect on man and animals at high
concentrations. Zinc at concentrations in excess of 5 mg/1
causes an undesirable taste which persists through conventional
treatment. For the prevention of adverse effects due to these
organoleptic properties of zinc, 5 mg/1 was adopted for the
ambient water criterion. Available data show that adverse
effects on aquatic life occur at concentrations as low as 0.047
mg/1 as a 24-hour average.
Toxic concentrations of zinc compounds cause adverse changes in
the morphology and physiology of fish. Lethal concentrations in
the range of 0.1 mg/1 have been reported. Acutely toxic
concentrations induce cellular breakdown of the gills, and
possibly the clogging of the gills with mucous. Chronically
toxic concentrations of zinc compounds cause general enfeeblement
and widespread histological changes to many organs, but not to
gills. Abnormal swimming behavior has been reported at 0.04
mg/1. Growth and maturation are retarded by zinc. It has been
observed that the effects of zinc poisoning may not become
apparent immediately, so that fish removed from zinc-contaminated
water may die as long as 48 hours after removal.
In general, salmonoids are most sensitive to elemental zinc in
soft water? the rainbow trout is the most sensitive in hard
waters. A complex relationship exists between zinc
concentration, dissolved zinc concentration, pH, temperature, and
calcium and magnesium concentration. Prediction of harmful
effects has been less than reliable and controlled studies have
not been extensively documented.
The major concern with zinc compounds in marine waters is not
with acute lethal effects but rather with the long-term sub-
lethal effects of the metallic compounds and complexes. Zinc
accumulates in some marine species and marine animals contain
zinc in the range of 6 to 1,500 mg/kg. From the point of view of
acute lethal effects, invertebrate marine animals seem to be the
most sensitive organism tested.
Toxicities of zinc in nutrient solutions have been demonstrated
for a number of plants. A variety of fresh water plants tested
manifested harmful symptoms at concentrations of 0.030 to 21.6
mg/1. Zinc sulfate has also been found to be lethal to many
plants and it could impair agricultural uses of the water.
Zinc is not destroyed when treated by a POTW, but will either
pass through to the POTW effluent or be retained in the POTW
sludge. It can interfere with treatment processes in the POTW
and can also limit the usefulness of municipal sludge.
In slug doses, and particularly in the presence of copper,
dissolved zinc can interfere with or seriously disrupt the
operation of POTW biological processes by reducing overall
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removal efficiencies, largely as a result of the toxicity of the
metal to biological organisms. However, zinc solids in the form
of hydroxides or sulfides do not appear to interfere with
biological treatment processes, on the basis of available data.
Such solids accumulate in the sludge.
The influent concentrations of zinc to a POTW have been observed
by the EPA to range from 0.017 to 3.91 mg/lf with a median
concent rat ion of 0.33 mg/1. Primary treatment is not efficient
in removing zinc; however, the microbial floe of secondary
treatment readily adsorbs zinc.
In a study of 258 POTW facilities, the median pass-through values
were 70 to 88 percent for primary plants, 50 to 60 percent for
trickling filter and biological process plants, and 30 to 40
percent for activated process plants. POTW effluent
concentrations of zinc ranged from 0.003 to 3.6 mg/1 (mean =
0.330, standard deviation = 0.464).
The zinc which does not pass through the POTW is retained in the
sludge. The presence of zinc in sludge may limit its use on
cropland. Sewage sludge contains 72 to over 30,000 mg/kg of
zinc, with 3,366 mg/kg as the mean value. These concentrations
are significantly greater than those normally found in soil,
which range from 0 to 195 mg/kg, with 94 mg/kg being a common
level. Therefore, application of sewage sludge to soil will
generally increase the concentration of zinc in the soil. Zinc
can be toxic to plants, depending upon soil pH. Lettuce,
tomatoes, turnips, mustard, kale, and beets are especially
sensitive to zinc contamination.
Oil and Grease. Oil and grease are taken together as one
pollutant parameter. This is a conventional pollutant and some
of its components are:
1. Light Hydrocarbons - These include light fuels such as
gasoline, kerosene, and jet fuel, and miscellaneous solvents used
for industrial processing, degreasing, or cleaning purposes. The
presence of these light hydrocarbons may make the removal of
other heavier oil wastes more difficult.
2. Heavy Hydrocarbons, Fuels, and Tars - These include the
crude oils, diesel oils, #6 fuel oil, residual oils, slop oils,
and in some cases, asphalt and road tar.
3. Lubricants and Cutting Fluids - These generally fall
into two classes: non-emulsifiable oils such as lubricating oils
and greases and emulsifiable oils such as water soluble oils,
rolling oils, cutting oils, and drawing compounds. Emulsifiable
oils may contain fat, soap, or various other additives.
4. Vegetable and Animal Fats and Oils - These originate
primarily from processing of foods and natural products.
These compounds can settle or float and may exist as solids or
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liquids depending upon factors such as method of use, production
process, and temperature of water.
Oil and grease even in small quantities cause troublesome taste
and odor problems. Scum lines from these agents are produced on
water treatment basin walls and other containers. Fish and water
fowl are adversely affected by oils in their habitat. Oil
emulsions may adhere to the gills of fish causing suffocation,
and the flesh of fish is tainted when microorganisms that
were exposed to waste oil are eaten. Deposition of oil in
the bottom sediments of water can serve to inhibit normal
benthic growth. Oil and grease exhibit an oxygen demand.
Many of the toxic organic pollutants will be found distributed
between the oil phase and the aqueous phase in industrial
wastewaters. The presence of phenols, PCBs, PAHs, and almost any
other organic pollutant in the oil and grease make
characterization of this parameter almost impossible. However,
all of these other organics add to the objectionable nature
of the oil and grease.
Levels of oil and grease which are toxic to aquatic organisms
vary greatly, depending on the type and the species
susceptibility. However, it has been reported that crude oil in
concent rat ions as low as 0.3 mg/1 is extremely toxic to
freshwater fish. It has been recommended that public water
supply sources be essentially free from oil and grease.
Oil and grease in quantities of 100 1/sq km show up as a sheen on
the surface of a body of water. The presence of oil slicks
decreases the aesthetic value of a waterway.
Oil and grease is compatible with a POTW activated sludge process
in limited quantity. However, slug loadings or high
concentrations of oil and grease interfere with biological
treatment processes. The oils coat surfaces and solid particles,
preventing access of oxygen, and sealing in some microorganisms.
Land spreading of POTW sludge containing oil and grease
uncontaminated by toxic pollutants is not expected to affect
crops grown on the treated land or animals eating those crops.
pH. Although not a specific pollutant, pH is related to the
acidity or alkalinity of a wastewater stream. It is not,
however, a measure of either. The term pH is used to describe
the hydrogen ion concentration (or activity) present in a given
solution. Values for pH range from 0 to 14, and these numbers
are the negative logarithms of the hydrogen ion concentrations.
A pH of 7 indicates neutrality. Solutions with a pH above 7 are
alkaline, while tnose solutions with a pH below 7 are acidic.
The relationship of pH and acidity and alkaliniby is not
necessarily linear or direct. Knowledge of the water pK is
useful in determining necessary measures for corrosion control,
sanitation, and disinfection. Its value is also necessary in the
treatment of industrial wastewaters to determine amounts of
chemicals required to remove pollutants and to measure their
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effectiveness. Removal of pollutants, especially dissolved
solids is affected by the pH of the wastewater.
Waters with a pH below 6.0 are corrosive to water works
structures, distribution lines, and household plumbing fixtures
and can thus add constituents to drinking water such as iron,
copper, zinc, cadmium, and lead. The hydrogen ion concentration
can affect the taste of the water, and at a low pH, water tastes
sour. The bactericidal effect of chlorine is weakened as the pH
increases, and it is advantageous to keep the pH close to 7.0,
This is significant for providing safe drinking water.
Extremes of pH or rapid pH changes can exert stress conditions or
kill aquatic life outright. Even moderate changes from accept-
able criteria limits of pH are deleterious to some species.
The relative toxicity to aquatic life of many materials is
increased by changes in the water pH. For example,
metallocyanide complexes can increase a thousand-fold in toxicity
with a drop of 1.5 pH units.
Because of the universal nature of pH and its effect on water
quality and treatment, it is selected as a pollutant parameter
for many industry categories. A neutral pH range (approximately
6 to 9) is generally desired because either extreme beyond this
range has a deleterious effect on receiving waters or the
pollutant nature of other wastewater constituents.
Pretreatment for regulation of pH is covered by the "General
Pretreatment Regulations for Existing and New Sources of
Pollution," 40 CFR 403.5. This section prohibits the discharge
to a POTW of "pollutants which will cause corrosive structural
damage to the POTW but in no case discharges with pH lower than
5,0 unless the works is specially designed to accommodate such
discharges."
Total Suspended Solids (TSS)» Suspended solids include both
organic and inorganic materials. The inorganic compounds include
sand, silt, and clay. The organic fraction includes such
materials as grease, oil, tar, and animal and vegetable waste
products. These solids may settle out rapidly, and bottom
deposits are often a mixture of both organic and inorganic
solids. Solids may be suspended in water for a time and then
settle to the bed of the stream or lake. These solids discharged
with man's wastes may be inert, slowly biodegradable materials,
or rapidly decomposable substances. While in suspension,
suspended solids increase the turbidity of the water, reduce
light penetration, and impair the photosynthetic activity of
aquatic plants.
Suspended solids in water interfere w i rh many industrial
processes and cause foaming in boilers and encrustations on
equipment exposed to such water, especially as the temperature
rises. They are undesirable in process water used in the
manufacture of steel, in the textile industry, in laundries,
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
in dyeing, and in cooling systems.
Solids in suspension are aesthetically displeasing. When they
settle to form sludge deposits on the stream or lake bed, they
are often damaging to the life in the water. Solids, when
transformed to sludge deposit, may do a variety of damaging
things, including blanketing the stream or lake bed and
thereby destroying the living spaces for those benthic organisms
that would otherwise occupy the habitat. When of an organic
nature, solids use a portion or all of the dissolved oxygen
available in the area. Organic materials also serve as a
food source for sludgeworms and associated organisms.
Disregarding any toxic effect attributable to substances leached
out by water, suspended solids may kill fish and shellfish by
causing abrasive injuries and by clogging the gills and
respiratory passages of various aquatic fauna. Indirectly,
suspended solids are inimical to aquatic life because they
screen out light, and they promote and maintain the
development of noxious conditions through oxygen depletion.
This results in the killing of fish and fish food organisms.
Suspended solids also reduce the recreational value of the
water.
Total suspended solids is a traditional pollutant which is
compatible with a well-run POTW. This pollutant, with the
exception of those components which are described elsewhere in
this section (e.g., heavy metal components), does not interfere
with the operation of a POTW. However, since a considerable
portion of the innocuous TSS may be inseparably bound to the
constituents which do interfere with POTW operation, or produce
unusable sludge, or subsequently dissolve to produce
unacceptable POTW effluent, TSS may be considered a toxic waste.
Aluminum. Aluminum, a nonconventional pollutant, is the most
common metallic element in the earth's crust, and the third most
abundant element (8.1 percent). It is never found free in
nature. Most rocks and various clays contain aluminum in the
form of aluminosilicate minerals. Generally, aluminum is first
converted to alumina (AI2O3) from bauxite ore. The alumina then
undergoes electrolytic reduction to form the metal. Aluminum
powders (used in explosives, fireworks, and rocket fuels) form
flammable mixtures in the air. Aluminum metal resists corrosion
under many conditions by forming a protective oxide film on the
surface. This oxide layer corrodes rapidly in strong acids and
alkalis, and by the electrolytic action of other metals with
which it comes in contact. Aluminum is light, malleable,
ductile, possesses high thermal and electrical conductivity, and
is non-magnetic. It can be formed, machined, or cast. Aluminum
is used in the building and construction, transportation, and the
container and packaging industries and competes with iron and
steel in these markets. Total U.S. production of primary
aluminum in 1981 was 4,948,000 tons. Secondary aluminum (from
scrap) production in 1981 was 886,000 tons.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Aluminum is soluble under both acidic and basic conditions, with
environmental transport occurring most readily under these
conditions. In water, aluminum can behave as an acid or base,
can form ionic complexes with other substances, and can
polymerize, depending on pH and the dissolved substances in
water. Aluminum's high solubility at acidic pH conditions makes
it readily available for accumulation in aquatic life. Acidic
waters consistently contain higher levels of soluble aluminum
than neutral or alkaline waters. Loss of aquatic life in
acidified lakes and streams has been shown to be due in part to
increased concentrations of aluminum in waters as a result of
leaching of aluminum from soil by acidic rainfall.
Aluminum has been found to be toxic to freshwater and marine
aquatic life. In freshwaters, acute toxicity and solubility
increases as pH levels increase above pH 7. This relationship
also appears to be true as the pH levels decrease below pH 7.
Chronic effects of aluminum on aquatic life have also been
documented. Aluminum has been found to be toxic to certain
plants. A water quality standard for aluminum was established
(U.S. Federal Water Pollution Control Administration, 1968) for
interstate agricultural and irrigation waters, which set a trace
element tolerance at 1 mg/1 for continuous use on all soils and
20 mg/1 for short-term use on fine-textured soils.
There are no reported adverse physiological effects on man from
exposure to low concentrations of aluminum in drinking water.
Large concentrations of aluminum in the human body, however, are
alleged to cause changes in behavior. Aluminum compounds,
especially aluminum sulfate, are major coagulants used in the
treatment of drinking water. Aluminum is not among the metals
for which a drinking water standard has been established.
The highest aluminum concentrations in animals and humans occur
in the lungs, mostly from the inhalation of airborne particulate
matter. Pulmonary fibrosis has been associated with the
inhalation of very fine particles of aluminum flakes and powders
among workers in the explosives and fireworks industries. An
occupational exposure Threshold Limit Value (TLV) of 5 mg/m3 is
recommended for pyro powders to prevent lung changes, and a
time weighted average (TWA) of 10 mg/m3 is recommended for
aluminum dust. High levels of aluminum have been found in the
brains, muscles, and bones of patients with chronic renal failure
who are being treated with aluminum hydroxide, and high brain
levels of aluminum are found in those suffering from Alzheimers
disease (presenile dementia) which manifests behavioral changes.
Aluminum and some of its compounds used in food preparation and
as food additives are generally recognized as safe and are
sanctioned by the Food and Drug Administration. No limits on
aluminum content in food and beverage products have been
established.
Aluminum has no adverse effects on POTW operation at
concentrations normally encountered. The results of an EPA study
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
of 50 POTW revealed that 49 POTW contained aluminum with effluent
concentrations ranging from less than 0.1 mg/1 to 1.07 mg/1 and
with an average removal of 82 percent.
Ammonia. Ammonia (chemical formula NH3) is a nonconventional
pollutant. It is a colorless gas with a very pungent odor,
detectable at concentrations of 20 ppm in air by the nose, and is
very soluble in water (570 gm/1 at 25°C). Ammonia is produced
industrially in very large quantities (nearly 20 million tons
annually in the U.S.). It is converted to ammonium compounds or
shipped in the liquid form (it liquifies at -33°C). Ammonia also
results from natural processes. Bacterial action on nitrates or
nitrites, as well as dead plant and animal tissue and animal
wastes produces ammonia. Typical domestic wastewaters contain 12
to 50 mg/1 ammonia.
The principal use of ammonia and its compounds is as fertilizer.
High amounts are introduced into soils and the water runoff from
agricultural land by this use. Smaller quantities of ammonia are
used as a refrigerant. Aqueous ammonia (2 to 5 percent solution)
is widely used as a household cleaner. Ammonium compounds find a
variety of uses in various industries; as an example, ammonium
hydroxide is used as a reactant in the purification of tungsten.
Ammonia is toxic to humans by inhalation of the gas or ingestion
of aqueous solutions. The ionized form, ammonium (NH/j"1"), is less
toxic than the un-ionized form. Ingestion of as little as one
ounce of household ammonia has been reported as a fatal dose.
Whether inhaled or ingested, ammonia acts destructively on mucous
membrane with resulting loss of function. Aside from breaks in
liquid ammonia refrigeration equipment, industrial hazard from
ammonia exists where solutions of ammonium compounds may be
accidentally treated with a strong alkali, releasing ammonia gas.
As little as 150 ppm ammonia in air is reported to cause
laryngeal spasms and inhalation of 5,000 ppm in air is
considered sufficient to result in death.
The behavior of ammonia in POTW is well documented because it is
a natural component of domestic wastewaters. Only very high
concentrations of ammonia compounds could overload POTW. One
study has shown that concentrations of un-ionized ammonia
greater than 90 mg/1 reduce gasification in anaerobic
digesters and concentrations of 140 mg/1 stop digestion
completely. Corrosion of copper piping and excessive
consumption of chlorine also result from high ammonia
concentrations. Interference with aerobic nitrification
processes can occur when large concentrations of ammonia
suppress dissolved oxygen. Nitrites are then produced instead of
nitrates. Elevated nitrite concentrations in drinking water are
known to cause infant methemoglobinemia.
Cobalt¦ Cobalt is a nonconventional pollutant. It is a brittle,
hard, magnetic, gray metal with a reddish tinge. Cobalt ores are
usually the sulfide or arsenic [smaltite-(Co, Ni)AS2; cobaltite-
CoAsS] and are sparingly distributed in the earth's crust.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Cobalt is usually produced as a by-product of mining copper,
nickel, arsenic, iron, manganese, or silver. Because of the
variety of ores and the very low concentrations of cobalt,
recovery of the metal is accomplished by several different
processes. Most consumption of cobalt is for alloys. Over
two-thirds of U.S. production goes to heat-resistant, magnetic,
and wear-resistant alloys. Chemicals and color pigments make up
most of the rest of consumption.
Cobalt and many of its alloys are not corrosion resistant
therefore, minor corrosion of any of the tool alloys or
electrical resistance alloys can contribute to its presence
in raw wastewater from a variety of manufacturing facilities.
Additionally, the use of cobalt soaps used in coatings may be
a general source of small quantities of the metal. Several
cobalt pigments are used in paints to produce yellows or
blues.
Cobalt is an essential nutrient for humans and other mammals, and
is present at a fairly constant level of about 1.2 mg in the
adult human body. Mammals tolerate low levels of ingested
water-soluble cobalt salts without any toxic symptoms; safe
dosage levels in man have been stated to be 2-7 mg/kg body weight
per day. A goitrogenic effect in humans is observed after the
systematic administration of 3-4 mg cobalt as cobaltous chloride
daily for three weeks. Fatal heart disease among heavy beer
drinkers was attributed to the cardiotoxic action of cobalt salts
which were formerly used as additives to improve foaming. The
carcinogenicity of cobalt in rats has been verified; however,
there is no evidence for the involvement of diecary cobalt in
carcinogenisis in mammals.
There are no data available on the behavior of cobalt in PQTW.
There are no data to lead to an expectation of adverse effects of
cobalt on POTW operation or the utility of sludge from POTW for
crop application. Cobalt which enters POTW is expected to pass
through to the effluent unless sufficient sulfide ion is present,
or generated in anaerobic processes in the POTW to cause
precipitation of the very insoluble cobalt sulfide.
Fluoride. Fluoride ion (F-) is a nonconventional pollutant.
Fluorine is an extremely reactive, pale yellow gas which is
never found free in nature. Compounds of fluorine - fluorides -
are found widely distributed in nature. The principal minerals
containing fluorine are fluorspar (CaF2) and cryolite
(Na2AlFg). Although fluorine is produced commercially in
small quantities by electrolysis of potassium bifiuoride in
anhydrous hydrogen fluoride, the elemental form bears little
relation to the combined ion. Total production of fluoride
chemicals in the U.S. is difficult to estimate because of the
varied uses. Large volume usage compounds are: calcium fluoride
(estimated 1, 500,000 tons in I", S. ) and sodium f luoraluminate
(estimated 100,000 tons in U.S.). Some fluoride compounds and
their uses are sodium fuoroaluminate - aluminum production;
calcium fluor-ide - steelmaking, hydrofluoric acid production,
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
enamel, iron foundry; boron trifluoride - organic synthesis;
antimony penta-fluoride - fluorocarbon production; fluoboric acid
and fluobor-ates - electroplating; perchloryl fluoride (CIO3F)
rocket fuel oxidizer; hydrogen fluoride - organic fluoride
manufacture, pickling acid in stainless steelmaking manufacture
of aluminum fluoride sulfur hexafluoride - insulator in high
voltage trans-formers; polytetrafluoroethylene - inert plastic.
Sodium fluoride is used at a concentration of about 1 mg/1 in
many public drinking water supplies to prevent tooth decay in
children.
The toxic effects of fluoride on humans include severe
gastroenteritis, vomiting, diarrhea, spasms, weakness, thirst,
failing pulse and delayed blood coagulation. Most observations
of toxic effects are made on individuals who intentionally or
accidentally ingest sodium fluoride intended for use as rat
poison or insecticide. Lethal doses for adults are estimated to
be as low as 2.5 g. At 1.5 ppm in drinking water, mottling of
tooth enamel is reported, and 14 ppm, consumed over a period of
years, may lead to deposition of calcium fluoride in bone and
tendons.
Fluorides found in irrigation waters in high concentrations have
caused damage to certain plants exposed to these waters. Chronic
fluoride poisoning of livestock has been observed. Fluoride from
waters apparently does not accumulate in soft tissue to a
significant degree; it is transferred to a very small extent into
the milk and to a somewhat greater degree in eggs. Data for
fresh water indicate that fluorides are toxic to fish.
Very few data are available on the behavior of fluoride in PCTW.
Under usual operating conditions in POTW, fluorides pass through
into the effluent. Very little of the fluoride entering
conventional primary and secondary treatment processes is
removed. In one study of POTW influents conducted by the U.S.
EPA, nine POTW reported concentrations of fluoride ranging
from 0.7 mg/1 to 1.2 mg/1, which is the range of
concentrations used for fluoridated drinking water.
Iron. Iron is a nonconventional pollutant. It is an abundant
metal found at many places in the earth's crust. The most common
iron ore is hematite (Fe203) from which iron is obtained by
reduction with carbon. Other forms of commercial ores are
magnetite (Fe30,j) and taconite (FeSiO). Pure iron is not
often found in commercial use, but it is usually alloyed with
other metals and minerals. The most common of these is carbon.
Iron is the basic element in the production of steel. Iron with
carbon is used for casting of major parts of machines and it can
be machined, cast, formed, and welded. Ferrous iron is used in
paints, while powdered iron can be sintered and used in powder
metallurgy. Iron compounds are also used to precipitate other
metals and undesirable minerals from industrial wastewater
streams.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Corrosion products of iron in water cause staining of porcelain
fixtures, and ferric iron combines with tannin to produce a dark
violet color. The presence of excessive iron in water
discourages cows from drinking and thus reduces milk production.
High concentrations of ferric and ferrous ions in water kill
most fish introduced to the solution within a few hours. The
killing action is attributed to coatings of iron hydroxide
precipitates on the gills. Iron oxidizing bacteria are
dependent on iron in water for growth. These bacteria form
slimes that can affect the aesthetic values of bodies of water
and cause stoppage of flows in pipes. However, high
concentrations of iron can precipitate on bottom sediments and
affect rooted aquatic and invertebrate benthos.
Iron is an essential nutrient and micro-nutrient for all forms of
growth. Drinking water standards in the U.S. set a limit of 0.3
mg/1 of iron in domestic water supplies based on aesthetic and
organoleptic properties of iron in water.
High concentrations of iron do not pass through a POTW into the
effluent. In some POTW iron salts are added to coagulate
precipitates and suspended sediments into a sludge. In an EPA
study of POTW, the concent ration of i ron in the effluent of 22
biological POTW meeting secondary treatment performance levels
ranged from 0.048 to 0.569 mg/1 with a median value of 0.25 mg/1.
This represented removals of 76 to 97 percent with a median of 87
percent removal.
Iron in sewage sludge spread on land used for agricultural
purposes is not expected to have a detrimental effect on crops
grown on the land.
Molybdenum. Molybdenum is present in the environment in trace
quantities. It is estimated that 3.6 x 1010 grams of molybdenum
are released into surface waters of the world each year by
natural processes. Most surface waters contain less than 0.020
mg Mo/1, and sea water concentrations range from 0.004 to 0.012
mg Mo/1. Finished waters in the United States contain a median of
0.0014 mg Mo/1 and a maximum of 0,068 mg Mo/1. Normal
concentrations in stream sediments range from 1 to 5 ppm Mo, and
the concentration of molybdenum tends to increase with decreasing
grain size.
Molybdenum is vitally necessary to plants and animals as it is a
constituent of essential enzymes needed for life processes.
Molybdenum concentrations in plants normally range from 1 to 2
ppm, though a range of tenths to hundredths of ppm have been
observed. Legumes tend to take up more molybdenum than other
plants. Accumulation of molybdenum in plants occurs without
detrimental effects.
Disease related to molybdenum in humans and animals has
historically been a result of excessive uptake of molybdenum.
Average daily intake of molybdenum in the United States varies
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
between 0,120 and 0.240 mg Mo/day, depending on age, sex, and
family income. Estimated daily intake of molybdenum in the
U.S.S.R. has been been reported to be between 0.329 and 0.376 mg
Mo/day. Abnormally high intakes, as high as 10 to 15 mg Mo/day,
have been documented in India, the U.S.S.R., and are suspected in
Turkey. Diet plays a large part in determining molybdenum uptake.
Legumes, cereal grains, leafy vegetables, liver, and kidney beans
are among the foods which contain greater concentrations of
molybdenum than fruits, root and stem vegetables, muscle meats,
and dairy products.
The only clinical symptom resulting from excessive molybdenum
uptake in humans is described as a gout-like disease. Study of a
human population receiving 10 to 15 mg Mo/day found high
incidence of this gout-like disease. In addition, increased uric
acid levels were noted. Another study where humans were exposed
to 10 mg Mo/day found greatly increased blood and urine levels of
molybdenum, and significant increases in uric acid excretion,
though the levels of uric acid were still within an acceptable
range for humans. For daily intake levels between 0.5 and 1.0
mg Mo, increased urinary copper excretion was noted in human
subjects. Increased urinary excretion of molybdenum has been
observed in humans whose water supply contained 0.050 to 0.200 mg
Mo/1. No biochemical or clinical effects are known in humans
whose water supply contains less than 0.050 mg Mo/1.
Sources of molybdenum for animals are primarily in pasture forage
and grain feed. Intake from water sources is not very
significant. Molybdenum is more toxic to animals than to humans,
and cattle and sheep are more susceptible to disease caused by
excessive molybdenum than rats, poultry, horses, and pigs. These
species differences are not understood. The Registry of Toxic
Effects for Chemical Substances states the lower toxic dose
(oral) for rats and rodents is 6.050 mg/kg.
All cattle are susceptible to roolybdenosis, with dairy cattle and
calves showing a higher susceptibility. The characteristic
scouring disease.and weight loss may be debilitating to the point
of permanent injury or death. Pastures containing 20 to 100 ppm
Mo (dry weight basis) are likely to induce the disease as
compared to health forage containing 3 to 5 ppm molybdenum or
less. It is difficult to assign a firm threshold value of
molybdenum contained in pasture that will include molybdenosis
because of the effects of two other dietary constituents. High
levels of molybdenum act to decrease the retention of copper in
an animal. Increased copper intake could, therefore, mitigate
the effect of high amounts of molybdenum. The second factor in
the diet is sulfate. It has oeen shown that in animals showing
increasing levels of molybdenum, an increase in dietary sulfate
causes more of the molybdenum to be excreted harmlessly.
A study of the effects on frogs to changes in the molybdenum
concentration in the aqueous environment concluded that while
high concentrations of aqueous molybdenum increased blood levels
of molybdenum ir. frogs, no deleterious effects were observed.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Laboratory bioassays involving rainbow trout have also been
conducted to determine long-term and acute toxicity of
molybdenum. Long-term toxicity tests included sodium molybdate
dissolved in demineralized water in concentrations ranging from 0
to 17 mg/1 Mo. After one year, results showed no significant
differences in growth and mortality for the exposed fish. Acute
toxicity results determined that for rainbow trout averaging 55
mm and 20 mm, the 96 hr LC50 is 1,320 mg/1 Mo and 800 mg/1 Mo,
respectively. Generally it was concluded that molybdenum as
molybdate in the aquatic environment constitutes little danger to
rainbow trout.
A third study was done to determine whether or not molybdenum
mining in Colorado was causing any environmental problems to the
natural wildlife in geographic areas impacted by molybdenum
mining and milling. Animals in the area were assayed, fish were
placed a mile downstream of mine tailings, and tailings were fed
to chicks. No serious adverse effects were discovered in
animals, and chicks fed 20 percent mine tailings remained
healthy. Some adverse effects and abnormal tissue were found in
the fish, but it was not certain whether these conditions were
caused by excessive molybdenum or other heavy metals also
present in the stream.
In conclusion, molybdenum is not very toxic to humans. Clinical
effects have been reported at steady intake levels of 10 to 15 mg
Mo/day, and biochemical effects in the range of 0.5 to 10 mg
Mo/day. Below 0.5 mg Mo/day, there is no evidence of substantial
toxic effects of molybdenum to humans.
The greatest problem of molybdenum toxicity involves cattle and
other ruminants. These animals are for unknown reasons
particularly susceptible to molybdenosis, and in addition, rely
entirely on forage for food. It is known that plants can
accumulate molybdenum without harmful effects but herbage
containing more than 20 ppm Mo (dry weight basis) may cause
molybdenosis in cattle.
High molybdenum content in surface waters in the United States in
rare and usually associated with molybdenum mining and milling,
uranium mining and milling, copper mining and milling, molybdenum
smelting and purification, or shale oil production. Toxicity of
molybdenum to some aquatic life has been shown to be low.
Surface or ground waters high in molybdenum that are used for
farmland irrigation may increase molybdenum content of plants.
This may have effects on animals further along the food chain.
Phenols (Total). "Total Phenols"' is a nonconvent i onal pollutant
parameter/ Total phenols is the result of analysis using the
4-AAF (4-aminoantipyrenc) method. This analytical procedure
measures the color development of reaction products between 4-AAP
and some phenols. The results are reported as phenol. Thus
"total phenol" is not total phenols because many phenols {notably
nitrophenols) do not react. Also, since each reacting phenol
contributes to the color development to a different degree, and
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
each phenol has a molecular weight different from others and from
phenol itself, analyses of several mixtures containing the same
total concentration in ma/1 of several phenols will give
different numbers depending on the proportions in the particular
mixture.
Despite these limitations of the analytical method, total phenols
is a useful parameter when the mix of phenols is relatively
constant and an inexpensive monitoring method is desired. In any
given plant or even in an industry subcategory, monitoring of
"total phenols" provides an indication of the concentration of
this group of priority pollutants as well as those phenols not
selected as priority pollutants. A further advantage is that the
method is widely used in water quality determinations.
In an EPA survey of 103 POTW the concentration of "total phenols"
ranged from 0.0001 mg/1 to 0.176 mg/1 in the influent, with a
median concentration of 0.016 mg/1. Analysis of effluents from
22 of these same POTW which had biological treatment meeting
secondary treatment performance levels showed "total phenols"
concentrations ranging from 0 mg/1 to 0.203 mg/1 with a median of
0.007. Removals were 64 to 100 percent with a median of 78
percent.
It must be recognized, however, that six of the 11 priority
pollutant phenols could be present in high concentrations and not
be detected. Conversely, it is possible, but not probable, to
have a high "total phenol" concentration without any phenol
itself or any of the 10 other priority pollutant phenols present.
A characterization of the phenol mixture to be monitored to
establish constancy of composition will allow "total phenols" to
be used with confidence.
Titanium. Titanium is a nonconventional pollutant. It is a
lustrous white metal occurring as the oxide in ilmenite
(FeO"Ti02) and rutile (Ti02). The metal is used in heat-
resistant, high-strength, light-weight alloys for aircraft and
missiles. It is also used in surgical appliances because of its
high strength and light weight. Titanium dioxide is used
extensively as a white pigment in paints, ceramics, and plastics.
Toxicity data on titanium are not abundant. Because of the lack
of definitive data, titanium compounds are generally considered
non-toxic. Large oral doses of titanium dioxide (Ti02) and
thiotitanic acid (H4TiS03) were tolerated by rabbits for several
days with no toxic symptoms. However, impaired reproductive
capacity was observed in rats fed 5 mg/1 titanium as titanite in
drinking water. There was also a reduction in the male/female
ratio and in the number of animals surviving to the third
generation. Titanium compounds are reported to inhibit several
enzyme systems and to be carcinogenic.
The behavior of titanium in POTW has not been studied. On the
basis of the insolubility of the titanium oxides in water, it is
expected that most of the titanium entering the POTW will be
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
removed by settling and will remain in the sludge. No data were
found regarding possible effects on plants as a result of
spreading titanium-containing sludge on agricultural cropland.
SUMMARY OF POLLUTANT SELECTION
After examining the sampling data, pollutants and pollutant
parameters were selected by subcategory for further consideration
for limitation. The selection of a pollutant was based on the
concentration of the pollutant in the raw sampling data and the
frequency of occurrence above concentrations considered
treatable. The pollutants selected under this rationale are
listed in Table VI-2 (page 131). The analysis that led to the
selection of these priority pollutants and the exclusion of
pollutants is presented in Section VI of each subcategory
supplement.
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Table VI-1
LIST OF 129 PRIORITY POLLUTANTS
Compound Name
1. acenaphthene
2. acrolein
3. acryloni tr ile
4. benzene
5. benzidene
6. carbon tetrachloride {tetrachloromethane)
Chlorinated benzenes (other than dichlorobenzenes)
7. chlorobenzene
8. 1,2,4-trichlorobenzene
9. hexachlorobenzene
Chlorinated ethanes (including 1,2-dichloroethane,
1,1,1-tr ichloroethane and hexachloroethane)
10.
1,2-dichloroethane
11.
1,1,1-trichloroethane
12.
hexachloroethane
13.
1,1-dichloroethane
14.
1,1,2-trichloroethane
15.
1,1,2,2-tetrachloroethane
16.
chloroethane
Chloroalkyl ethers (chloromethyl, chloroethyl and
mixed ethers)
17. bis(chloromethyl) ether (deleted)
18. bis (2-chloroethyl) ether
19. 2-chloroethyl vinyl ether (mixed)
Chlorinated naphthalene
20. 2-chloronaphthalene
Chlorinated phenols (other than those listed elsewhere:
includes trichlorophenols and chlorinated cresols)
21. 2,4,6-trichlorophenol
22. parachlorometa cresol
23. chloroform (trichicromethane)
24. 2-chlorophenoi
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GENERAL DEVELOPMENT DOCUMENT SECT
Table Vl-1 (Continued)
LIST OF 129 PRIORITY POLLUTANTS
Dichlorobenzenes
25. 1,2-dichlorobenzene
26. 1,3-dichlorobenzene
27. 1,4-dichlorobenzene
Dichlorobenz idine
28. 3,31-dichlorobenzidine
Dichloroethylenes (1,1-dichloroethylene and
1,2-dichloroethylene)
29. 1,1-dichloroethylene
30. 1,2-trans-dichloroethylene
31. 2,4-dichlorophenol
Dichloropropane and dichloropropene
32. 1,2-dichloropropane
33. 1,2-dichloropropylene {1,3-dichloropropene)
34. 2,4-dimethylphenol
Dinitrotoluene
35. 2,4-dinitrotoluene
36. 2,6-dinitrotoluene
37. 1,2-diphenylhydrazine
38. ethylbenzene
39. fluoranthene
Haloethers (other than those listed elsewhere)
40. 4-chlorophenyl phenyl ether
41. 4-bromophenyl phenyl ether
42. bis(2-chloroisopropyl) ether
43. bis(2-choroethoxy) methane
Halomethanes (other than those listed elsewher
44. methylene chloride (dichloromethane)
45. methyl chloride (chloromethane)
46. methyl bromide (bromcmethane)
127
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Table VI-1 (Continued)
LIST OF 129 PRIORITY POLLUTANTS
Halomethanes (Cont.)
47. bromoform {tribromomethane)
48. dichlorobrornomethane
49. trichlorofluoromethane (deleted)
50. dichlorofluoromethane (deleted)
51. chlorodibromomethane
52. hexachlorobutadiene
53. hexachlorocyclopentadiene
54. isophorone
55. naphthalene
56. nitrobenzene
Nitrophenols (including 2,4-dinitrophenol and dinitrocresol)
57. 2-nitrophenol
58. 4-nitrophenol
59. 2,4-dinitrophenol
60. 4,6-dinitro-o-cresol
Nitrosamines
61. N-nitrosodimethylamine
62. N-nit rosodiphenylamine
63. N-nitrosodi-n-propylaraine
64. pentachlorophenol
65. phenol
Phthalate esters
66. bis(2-ethylhexyl) phthalate
67. butyl benzyl phthalate
68. di-n-butyl phthalate
69. di-n-octyl phthalate
70. diethyl phthalate
71. dimethyl phthalate
Polynuclear aromatic hydrocarbons
72. benzo (a)anthracene (1,2-benzanthracene)
73. benzo (a)pyrene (3,4-benzcpyrene)
74. 3,4-benzofluoranthene
75. benzo(k)fluoranthane (11,12~benzofluoranthene)
128
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
Table VI-1 (Continued)
LIST OF 129 PRIORITY POLLUTANT
Polynuclear aromatic hydrocarbons (Cont.)
76.
chrysene
77.
acenaphthylene
78.
anthracene
79.
beqzo(ghi)perylene (1,11-benzoperylene)
80.
fluorene
81.
phenanthrene
82 .
dibenzo (a,h)anthracene (1,2,5,6-dibenzanthracene)
83.
indeno (1,2,3-cd)pyrene (w,e,o-phenylenepyrene)
84.
pyrene
85.
tetrachloroethylene
86.
toluene
87.
tr ichloroethylene
88.
vinyl chloride (chloroethylene)
Pesticides and metabolites
89.
aldrin
90.
dieldrin
91 •
chlordane (technical mixture and metabolites)
DDT and metabolites
92. 4,4'-DDT
93. 4,4'-DDE(p, p 'DDX)
94. 4,4'-DDD(p, p TDE)
Polychlor inated biphenyls (PCB's)
Endosulfan and metabolites
95. a-endosulfan-Alpha
96. b-endosulfan-Beta
97. endosulfan sulfate
Endrin and metabolites
98. endrin
99. endrin aldehyde
Heptachlor and metabolites
100. heptachlor
101. heptachlor epoxide
129
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GENERAL DEVELOPMENT DOCUMENT SECT -
Table Vl-1 (Continued)
LIST OF 129 PRIORITY POLLUTANTS
Hexachlorocyclohexane (all isomers)
102. a-BHC-Alpha
103. b-BHC-Beta
104. r-BHC {lindane)-Gamma
105. g-BHC-Delta
106. PCB-1242 (Arochlor 1242)
107. PCB-1254 (Arochlor 1254)
108. PCB-12 21 (Arochlor 1221)
109. PCB-1232 (Arochlor 1232)
110. PCB-1248 (Arochlor 1248)
111. PCB-1260 (Arochlor 1260)
112. PCB-1016 (Arochlor 1016)
Other
113. toxaphene
Metals and Cyanide, and Asbestos
114.
antimony
115.
arsenic
116.
asbestos (Fibrous)
117.
beryllium
118.
cadmium
119.
chromium {Total)
120.
copper
121.
cyanide (Total)
122.
lead
123.
mercury
124.
nickel
125.
selenium
126.
silver
127.
thallium
128.
zinc
129.
2,3,7,8-tetra chlorodibenzo-p-dioxin (TCDD)
130
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GENERAL DEVELOPMENT DOCUMENT SECT - VI
TABLE VI-2
POLLUTANTS SELECTED FOR FURTHER CONSIDERATION BY SUBCATEGORY
Bauxite Refining
21
24
31
57
58
6 5
2,4,6-tr ichlorophenol
2-chlorophenol
2,4-dichlorophenol
2-nitrophenol
4-nitrophenol
phenol
phenols (4-AAP)
pH
Primary Aluminum Smelting Subcategory
1. acenaphthene
39. fluoranthene
55. naphthalene
12. benzo(a)anthracene {1,2-benzanthracene)
73. benzo(a)pyrene
76. chrysene
78. anthracene (a)
79. benzo(ghi)perylene (1,11-benzoperylene)
80. fluorene
81. phenanthrene (a)
82. dibenzo(a,h)anthracene (1,2,5,6-dibenzanthracene;
84. pyrene
114. antimony
115. arsenic
116. asbestos (Fibrous)
118. cadmium
119. chromium (Total)
120. copper
121. cyanide (Total)
122. lead
124. nickel
125. selenium
128. zinc
aluminum
fluoride
oil and grease
TSS
pH
(a) Reported together
131
-------
GENERAL DEVELOPMENT DOCUMENT SECT
VI
TABLE VI-2 (Continued)
POLLUTANTS SELECTED FOR FURTHER CONSIDERATION BY SUBCATEGORY
Secondary Aluminum Subcategory
65. phenol
118. cadmium
122. lead
128. zinc
aluminum
ammonia (N)
total phenolics (by 4-AAP method)
oil and grease
TSS
pH
Primary Electrolytic Copper Refining Subcategory
115.
arsenic
119.
chromium (Total)
120 .
copper
122.
lead
124.
nickel
126.
silver
128.
zinc
TSS
pH
Primary Lead Subcategory
116. asbestos (Fibrous)
118. cadmium
122. lead
128. zinc
TSS
pH
Primary Zinc Subcategory
115. arsenic
116. asbestos (Fibrous)
118. cadmium
119. chromium (Total)
120. copper
122. lead
124. nickel
126. silver
128. zinc
TSS
pH
132
-------
GENERAL DEVELOPMENT DOCUMENT SECT
- VI
TABLE VI-2 (Continued)
POLLUTANTS SELECTED FOR FURTHER CONSIDERATION BY SUBCATEGORY
Metallurgical Acid Plants
114. antimony
115. arsenic
118. cadmium
119. chromium
120. copper
122. lead
123. mercury
124. nickel
125. selenium
126. silver
128. zinc
fluoride
molybdenum
total suspended solids (TSS)
pH
Primary Tungsten Subcategory
11.
1,1,1-trichloroethane
55 .
naphthalene
65.
phenol
73.
benzo(a)pyrene
79.
benzo(ghi)perylene
82.
dibenzo{a, h)anthracene
85.
tetrachloroethylene
86.
toluene
118.
cadmium
119.
chromium (Total)
122.
lead
124.
nickel
126.
siIver
127 .
thallium
128.
z inc
ammonia (N)
TSS
pH
133
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VI
TABLE VI-2 (Continued)
POLLUTANTS SELECTED FOR FURTHER CONSIDERATION BY SUBCATEGORY
Primary Columbium-Tantalum Subcategory
4. benzene
6. carbon tetrachloride
7. chlorobenzene
8. 1,2,4-trichlorobenzene
10. 1,2-dichloroethane
30. 1,2-trans-dichloroethylene
38. ethylbenzene
51, chlorodibromomethane
85. tetrachloroethylene
87. trichloroethylene
114. antimony
115. arsenic
116. asbestos (Fibrous)
118. cadmium
119. chromi um (Total)
120. copper
122. lead
124. nickel
125. seleni um
127. thallium
128. zinc
ammonia (N)
fluoride
TSS
PH
134
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VI
TABLE VI-2 (Continued)
POLLUTANTS SELECTED FOR FURTHER CONSIDERATION BY SUBCATEGORY
Secondary Silver Subcategory
4. benzene
6. carbon tetrachloride (tetrachloromethane)
10. 1,2-dichloroethane
11. 1,1,1-trichloroethane
29. 1,1-dichloroethyi ene
30. 1,2-trans-dichloroethylene
38. ethyl benzene
84. pyrene
85. tetrachloroethylene
86. toluene
87. trichloroethylene
114. antimony
115. arsenic
118. cadmium
119. chromium (Total)
120. copper
121. cyanide
122. lead
124. nickel
125. selenium
126. silver
127. thallium
128. zinc
ammonia (N)
total phenolics (by 4-AAP method)
TSS
pH
Secondary Lead Subcategory
114 .
antimony
115.
arsenic
118.
cadmium
119.
chromium (Total
120.
copper
122.
lead
124.
nickel
126.
siIver
127.
thallium
128.
zinc
ammonia
TSS
pH
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VI
TABLE VI-2 (Continued)
POLLUTANTS SELECTED FOR FURTHER CONSIDERATION BY SUBCATEGORY
Primary Antimony Subcategory
114, antimony
115. arsenic
118. cadmium
120. copper
122. lead
123. mercury
128. zinc
total suspended solids {TSS)
pH
Primary Beryllium
117. beryllium
119. chromium
120. copper
121. cyanide
ammonia (as N)
fluoride
total suspended solids (TSS)
pH
Primary and Secondary Germanium and Gallium
| II ¦ III! 111. ¦¦ I III T# — MM | | II I———————— || I
114. antimony
115. arsenic
118. cadmium
119. chromium
120. copper
122. lead
124. nickel
125. selenium
126. silver
127. thallium
128. zinc
fluor ide
germanium
gallium
total suspended solids (TSS)
pH
136
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VI
TABLE VI-2 (Continued)
POLLUTANTS SELECTED FOR FURTHER CONSIDERATION BY SUBCATEGORY
Secondary Indium
118, cadmium
119. chromium
122. lead
124. nickel
125. selenium
126. silver
127. thallium
128. zinc
indium
total suspended solids (TSS)
pH
Secondary Mercury
122. lead
123. mercury
127. thallium
128. zinc
total suspended solids (TSS)
pH
Primary Molybdenum and Rhenium
115. arsenic
119. chromium (total)
120. copper
122. lead
124. nickel
125. selenium
128. zinc
ammonia (as N)
fluoride
molybdenum
rhenium
total suspended solids (TSS)
pH
137
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VI
TABLE VI-2 (Continued)
POLLUTANTS SELECTED FOR FURTHER CONSIDERATION BY SUBCATEGORY
Secondary Molybdenum and Vanadium
115. arsenic
119. chromium
120. copper
122. lead
124. nickel
128. zinc
aluminum
ammonia (as N)
boron
cobalt
germanium
iron
manganese
molybdenum
tin
titanium
vanadium
total suspended solids
pH
Primairy Nickel and Cobalt
120. copper
124. nickel
128. zinc
cobalt
ammonia (as N)
total suspended solids (TSS)
pH
Secondary Nickel
115. arsenic
119. chromium
120. copper
124. nickel
128. zinc
total suspended solids (TSS)
pH
138
-------
GENERAL DEVELOPMENT DOCUMENT SECT
- VI
TABLE VI-2 (Continued)
POLLUTANTS SELECTED FOR FURTHER CONSIDERATION BY SUBCATEGORY
Primary Precious Metals and Mercury
115. arsenic
118. cadmium
119. chromium
120. copper
122. lead
123. mercury
124. nickel
126. silver
127. thallium
128. zinc
gold
oil and grease
total suspended solids (TSS)
pH
Secondary Precious Metals
114. antimony
115. arsenic
118. cadmium
119. chromium
120. copper
121. cyanide
122. lead
124. nickel
125. selenium
126. silver
127. thallium
128. zinc
ammonia (as N)
gold
palladium
plat inum
total suspended solids (TSS)
pH
139
-------
GENERAL DEVELOPMENT DOCUMENT
SECT
- VI
TABLE VI-2 (Continued)
POLLUTANTS SELECTED FOR FURTHER CONSIDERATION BY SUBCATEGORY
Primary Rare Earth Metals
4.
benzene
9.
hexachlorobenzene
115.
arsenic
118.
cadmium
119.
chromium (total)
120.
copper
122.
lead
124.
nickel
125.
selenium
126.
silver
127 .
thallium
128.
zinc
total suspended solids (TSS)
pH
Secondary Tantalum
114. antimony
120. copper
122. lead
124. nickel
126. silver
128. zinc
tantalum
total suspended solids (TSS)
pH
140
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VI
TABLE VI-2 (Continued)
POLLUTANTS SELECTED FOR FURTHER CONSIDERATION BY SUBCATEGORY
Secondary Tin
114. antimony
115. arsenic
118. cadmium
119. chromium
120. copper
121. cyanide
122. lead
124. nickel
125. selenium
126. silver
127. thallium
128. zinc
aluminum
barium
boron
fluoride
i ron
manganese
tin
total suspended solids (TSS)
pH
Primary and Secondary Titanium
114. antimony
118. cadmium
119. chromium (total)
120. copper
122. lead
124. nickel
127. thallium
128. zinc
titanium
oil and grease
total suspended solids (TSS)
PH
141
-------
GENERAL DEVELOPMENT DOCUMENT SECT
- VI
TABLE VI-2 (Continued)
POLLUTANTS SELECTED FOR FURTHER CONSIDERATION BY SUBCATEGORY
Secondary Tungsten and Cobalt
115. arsenic
118. cadmium
119. chromium
120. copper
122. lead
124. nickel
126. silver
128. zinc
ammonia (as N)
cobalt
tungsten
oil and grease
total suspended solids (TSS)
pH
Secondary Uranium
114. antimony
115. arsenic
118. cadmium
119. chromium (total)
120. copper
122. lead
124. nickel
125. selenium
126. silver
128. zinc
fluor ide
uranium
total suspended solids (TSS)
PH
Primary Zirconium and Hafnium
118. cadmium
119. chromium (total)
121. cyanide (total)
122. lead
124. nickel
127. thallium
128. zinc
ammonia (as N)
hafnium
radium-226
z i r cotiium
total suspended solids (TSS)
pH
-------
72
73
74
75
76
77
78
79
80
81
GENERAL DEVELOPMENT DOCUMENT SECT - VI
FIGURE VI-3
POLYNUCULEAR AROMATIC HYDROCARBONS
(Toxic Pollutant No's 72 - 84)
Benzo(a)anthracene (1,2-benzanthracene) ^ m.p. 162°C
Benzo(ajpyrene (3,4-benzopyrene)
m.p. 176°C
3»4-Benzofluoranthene
m.p. 168°C
Benzo(k)fluoranthene
(11,12-benzofluoranthene)
m.p. 217°C
Chrysene {1,2-benzphenanthrene)
m.p. 2 5 5°C
Acenaphthylene
HC-CH
COIQ
m.p. 9 2°C
Anthracene
;oTotoi
m.p. 216°C
Benzo{ghiJperylene
{1,12-benzoperylene)
m.p. not reported
Fluorene (alpha-diphenylenemethane) . m.p. 116°C
©r~£o}
Phenanthrene
143
m.p. 101°C
-------
GENERAL DEVELOPMENT DOCUMENT SECT
- VI
FIGURE VI-3 (Continued)
FOLYNUCULEAR AROMATIC HYDROCARBONS
tToxic Pollutant No's 72 - 84)
82 Dibenzo(a,h)anthracene
(1,2,5,6-dibenzoanthracene)
m.p. 269°C
83 Indeno (1,2,3-cd)pyrene
(2,3-o-phenylenepyrene)
m.p. not available
84 Pyrene
m.p. 156°C
144
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
NONFERROUS METALS MANUFACTURING
SECTION VII
CONTROL AND TREATMENT TECHNOLOGY
This section describes the treatment techniques currently used or
available to remove or recover wastewater pollutants normally
generated by the nonferrous metals manufacturing industrial point
source category. Included are discussions of individual end-of-
pipe treatment technologies and in-plant technologies. These
treatment technologies are widely used in many industrial
categories, and data and information to support their
effectiveness has been drawn from a similarly wide range of
sources and data bases.
END-OF-PIPE TREATMENT TECHNOLOGIES
Individual recovery and treatment technologies are described
which are used or are suitable for use in treating wastewater
discharges from nonferrous metals manufacturing plants. Each
description includes a functional description and discussion of
application and performance, advantages and limitations,
operational factors (reliability, maintainability, solid waste
aspects), and demonstration status. The treatment processes
described include both technologies presently demonstrated within
the nonferrous metals manufacturing category, and technologies
demonstrated in treatment of similar wastes in other industries.
Nonferrous metals manufacturing wastewaters
characteristically may contain treatable concentrations of
toxic metals. The toxic metals antimony, arsenic,
beryllium, cadmium, chromium, copper, lead, mercury,
nickel, selenium, silver, thallium and zinc are found in
nonferrous metals manufacturing wastewater streams at
treatable concentrations; and are generally free from strong
chelating agents. Aluminum, ammonia, barium, boron, cesium,
cobalt, columbium, cyanide, fluoride, gallium, germanium, gold,
hafnium, indium, iron, manganese, molybdenum, palladium,
phosphorus, platinum, radium-226, rhenium, rubidium, tantalum,
tin, titanium, tungsten, uranium, vanadium, zirconium and some
toxic organics (polynuclear aromatic hydrocarbons and phenols)
also may be present. The toxic inorganic pollutants constitute
the most significant wastewater pollutants in this category.
In general, these pollutants are removed by chemical
precipitation and sedimentation or filtration. Most of them may
be effectively removed by precipitation of metal hydroxides or
carbonates utilizing the reaction with lime, sodium hydroxide, or
sodium carbonate. For some, improved removals are provided by
the use of sodium sulfide or ferrous sulfide to precipitate the
pollutants as sulfide compounds with very low solubilities.
145
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
Discussion of end-of-pipe treatment technologies is divided into
three parts: the major technologies; treatment effectiveness of
major technologies; and minor technologies.
MAJOR TECHNOLOGIES
In Sections IX, X, XI, and XII the rationale for selecting
model treatment systems is discussed. The individual
technologies used in the system are described here. The
major end-of-pipe technologies for treating nonferrous
metals manufacturing wastewaters are: (1) chemical reduction of
chromium, (2) chemical precipitation, (3) cyanide
precipitation, (4) granular bed filtration, (5) pressure
filtration, (6) settling, and (7) skimming. In practice,
precipitation of metals and settling of the resulting
precipitates is often a unified two-step operation. Suspended
solids originally present in raw wastewaters are not
appreciably affected by the precipitation operation and are
removed with the precipitated metals in the settling operations.
Settling operations can be evaluated independently of hydroxide
or other chemical precipitation operations, but hydroxide and
other chemical precipitation operations can only be evaluated in
combination with a solids removal operation.
1 * Chemical Reduction of Chromium
Description of the Process. Reduction is a chemical reaction in
which electrons are transferred to the chemical being reduced
from the chemical initiating the transfer (the reducing agent).
Sulfur dioxide, sodium bisulfite, sodium metabisulfite, and
ferrous sulfate form strong reducing agents in aqueous solution
and are often used in industrial waste treatment facilities for
the reduction of hexavalent chromium to the trivalent form. The
reduction allows removal of chromium from solution in conjunction
with other metallic salts by alkaline precipitation. Hexavalent
chromium is not precipitated as the hydroxide.
Gaseous sulfur dioxide is a widely used reducing agent and
provides a good example of the chemical reduction process.
Reduction using other reagents is chemically similar. The
reactions involved may be illustrated as follows:
3 S02+ 3 H20 > 3 H2S03
3 H2S03 + 2H2Cr04 > Cr2(S04)3 + 5 H20
The above reaction is favored by low pH. A pH of from 2 to 3 is
normal for situations requiring complete reduction. At pH levels
above 5, the reduction rate is slow. Oxidizing agents such as
dissolved oxygen and ferric iron interfere with the reduction
process by consuming the reducing agent.
A typical treatment consists of 45 minutes retention in a
reaction tank. The reaction tank has an electronic recorder-
146
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
controller device to control process conditions with respect to
pH and oxidation reduction potential (ORP). Gaseous sulfur
dioxide is metered to the reaction tank to maintain the ORP
within the range of 250 to 300 millivolts. Sulfuric acid is
added to maintain a pH level of from 1.8 to 2.0. The reaction
tank is equipped with a propeller agitator designed to provide
approximately one turnover per minute. Figure VII-13 (Page 266)
shows a continuous chromium reduction system.
Application and Performance¦ Chromium reduction is most usually
required to treat electroplating and metal surfacing rinse
waters, but may also be required in nonferrous metals
manufacturing plants. A study of an operational waste treatment
facility chemically reducing hexavalent chromium has shown that a
99.7 percent reduction efficiency is easily achieved. Final
concentrations of 0.05 mg/1 are readily attained, and
concentrations of 0.01 mg/1 are considered to be attainable by
properly maintained and operated equipment.
Advantages and Limitations. The major advantage of chemical
reduction to reduce hexavalent chromium is that it is a fully
proven technology based on many years of experience. Operation
at ambient conditions results in minimal energy consumption, and
the process, especially when using sulfur dioxide, is well suited
to automatic control. Furthermore, the equipment is readily
obtainable from many suppliers, and operation is straightforward.
One limitation of chemical reduction of hexavalent chromium is
that for high concentrations of chromium, the cost of treatment
chemicals may be prohibitive. When this situation occurs, other
treatment techniques are likely to be more economical. Chemical
interference by oxidizing agents is possible in the treatment of
mixed wastes, and the treatment itself may introduce pollutants
if not properly controlled. Storage and handling of sulfur
dioxide is somewhat hazardous.
Operational Factors. Reliability: Maintenance consists of
periodic removal of sludge; the frequency of removal depends on
the input concentrations of det rimental constituents.
Solid Waste Aspects: Pretreatment to eliminate substances which
will interfere with the process may often be necessary. This
process produces trivalent chromium which can be controlled by
further treatment. However, small amounts of sludge may be
collected as the result of minor shifts in the solubility of the
contaminants. This sludge can be processed by the main sludge
treatment equipment.
Demonstration Status¦ The reduction of chromium waste by sulfur
dioxide or sodium bisulfite is a classic process and is used by
numerous plants which have hexavalent chromium compounds in
wastewaters from operations such as electroplating, conversion
coating and noncontact cooling.
147
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
2. Chemical Precipitation
Dissolved toxic metal ions and certain anions may be chemically
precipitated for removal by physical means such as sedimentation,
filtration, or centrifugation. Several reagents are commonly
used to effect this precipitation:
1) Alkaline compounds such as lime or sodium hydroxide may be
used to precipitate many toxic metal ions as metal hydroxides.
Lime also may precipitate phosphates as insoluble calcium
phosphate, fluorides as calcium fluoride and arsenic as calcium
arsenate,
2) Both "soluble" sulfides such as hydrogen sulfide or sodium
sulfide and "insoluble" sulfides such as ferrous sulfide may be
used to precipitate many heavy metal ions as metal sulfides.
3) Ferrous sulfate, zinc sulfate or both (as is required) may be
used to precipitate cyanide as a ferro or zinc ferricyanide
complex.
4) Carbonate precipitates may be used to remove metals either by
direct precipitation using a carbonate reagent such as calcium
carbonate or by converting hydroxides into carbonates using
carbon dioxide.
These treatment chemicals may be added to a flash mixer or rapid
mix tank, to a presettling tank, or directly to a clarifier or
other settling device. Because metal hydroxides tend to be
colloidal in nature, coagulating agents may also be added to
facilitate settling. After the solids have been removed, final
pH adjustment may be required to reduce the high pH created by
the alkaline treatment chemicals.
Chemical precipitation as a mechanism for removing metals from
wastewater is a complex process of at least two steps
precipitation of the unwanted metals and removal of the
precipitate. Some very small amount of metal will remain
dissolved in the wastewater after precipitation is
complete. The amount of residual dissolved metal depends on
the treatment chemicals used and related factors. The
effectiveness of this method of removing any specific metal
depends on the fraction of the specific metal in the raw
waste (and hence in the precipitate) and the effectiveness of
suspended solids removal. In specific instances, a sacrifical
ion such as iron or aluminum may be added to aid in the removal
of toxic metals by co-precipitation process and reduce the
fraction of a specific metal in the precipitate.
Application and Performance. Chemical precipitation is used in
nonferrous metals manufacturing for precipitation of dissolved
metals. It can be used to remove metal ions such as aluminum,
antimony, arsenic, beryllium, cadmium, chromium, copper, lead,
mercury, nickel, zinc, cobalt, iron, manganese, tungsten,
molybdenum and tin. The process is also applicable to any
148
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GENERAL DEVELOPMENT DOCUMENT SECT -VII
substance that can be transformed into an insoluble form such
as fluorides, phosphates, soaps, sulfides and others. Because
it is simple and effective, chemical precipitation is extensively
used for industrial waste treatment.
The performance of chemical precipitation depends on several
variables. The more important factors affecting precipitation
effectiveness are:
1. Maintenance of an appropriate (usually alkaline) pH throughout
the precipitation reaction and subsequent settling;
2. Addition of a sufficient excess of treatment ions to drive the
precipitation reaction to completion;
3. Addition of an adequate supply of sacrifical ions (such as
iron or aluminum) to ensure precipitation and removal of specific
target ions; and
4. Effective removal of precipitated solids (see appropriate
solids removal technologies).
Control of pH. Irrespective of the solids removal technology
employed, proper control of pH is absolutely essential for
favorable performance of precipitation-sedimentation
technologies. This is clearly illustrated by solubility curves
for selected metals hydroxides and sulfides shown in Figure VII-
1, (page 254), and by plotting effluent zinc concentrations
against pH as shown in Figure VII-2 (page 255). Figure
VII-2 was obtained from Development Document for the
Proposed Effluent Limitations Guidelines and New Source
Performance Standards for the Zinc Segment of Nonferrous
Metals Manufacturing Point Source Category, U.S. E.P.A., EPA
440/1-74/033, November, 1974. Figure VII-2 was plotted from
the sampling data from several facilities with metal finishing
operations. It is partially illustrated by data obtained from
3 consecutive days of sampling at one metal processing plant
(47432) as displayed in Table VII-1 (page 235). Flow through
this system is approximately 49,263 l/h (13,000 gal/hr).
This treatment system uses lime precipitation (pH adjustment)
followed by coagulant addition and sedimentation. Samples were
taken before (in) and after (out) the treatment system. The best
treatment for removal of copper and zinc was achieved on day one,
when the pH was maintained at a satisfactory level. The poorest
treatment was found on the second day, when the pH slipped to an
unacceptably low level; intermediate values were achieved on the
third day, when pH values were less than desirable but in between
those for the first and second days.
Sodium hydroxide is used by one facility (plant 439) for pH
adjustment and chemical precipitation, followed by settling
(sedimentation and a polishing lagoon) of precipitated solids.
Samples were taken prior to caustic addition and following the
polishing lagoon. Flow through the system is approximately
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22,700 1/hr. (6,000 gal/hr). These data displayed in Table VII-2
(page 235) indicate that the system was operated efficiently.
Effluent pH was controlled within the range of 8.6 to 9.3, and,
while raw waste loadings were not unusually high, most toxic
metals were removed to very low concentrations.
Lime and sodium hydroxide (combined) are sometimes used to
precipitate metals. Data developed from plant 40063, a facility
with a metal bearing wastewater, exemplify efficient operation of
a chemical precipitation and settling system. Table VI1-3 (page
236) shows sampling data from this system, which uses lime
and sodium hydroxide for pH adjustment and chemical
precipitation, polyelectrolyte flocculant addition, and
sedimentation. Samples were taken of the raw waste influent
to the system and of the clarifier effluent. Flow through the
system is approximately 19,000 1/hr (5,000 gal/hr).
At this plant, effluent TSS levels were below 15 mg/1 on each
day, despite average raw waste TSS concentrations of over 3500
mg/1. Effluent pH was maintained at approximately 8, lime
addition was sufficient to precipitate the dissolved metal ions,
and the flocculant addition and clarifier retention served to
remove effectively the precipitated solids.
Sulfide precipitation is sometimes used to precipitate metals
resulting in improved metals removals. Most metal sulfides are
less soluble than hydroxides, and the precipitates are frequently
more dependably removed from water. Solubilities for selected
metal hydroxide, carbonate and sulfide precipitates are shown in
Table VII-4, (page 236). (Source: Lange's Handbook of
Chemistry). Sulfide precipitation is particularly effective in
removing specific metals such as silver and mercury. Sampling
data from three industrial plants using sulfide precipitation
appear in Table VII-5 (page 237). In all cases except iron,
effluent concentrations are below 0.1 mg/1 and in many cases
below 0.01 mg/1 for the three plants studied.
Sampling data from several chlorine-caustic manufacturing plants
using sulfide precipitation demonstrate effluent mercury
concentrations varying between 0.009 and 0.03 mg/1. As shown in
Figure VII-1 (page 254), the solubilities of PbS and Ag2S
are lower at alkaline pH levels than either the corresponding
hydroxides or other sulfide compounds. This implies
that removal performance for lead and silver sulfides should be
comparable to or better than that for the metal hydroxides.
Bench-scale tests on several types of metal finishing
and manufacturing wastewater indicate that metals removal to
levels of less than 0.05 mg/1 and in some cases less than
0.01 mg/1 are common in systems using sulfide precipitation
followed by clarification. Some of the bench-scale data,
particularly in the case of lead, do not support such low
effluent concentrations. However, lead is consistently
removed to very low levels (less than 0.02 mg/1) in
systems using hydroxide and carbonate precipitation and
sedimentation.
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Of particular interest is the ability of sulfide to precipitate
hexavalent chromium (Cr + 6) without prior reduction to the
trivalent state as is required in the hydroxide process-
When ferrous sulfide is used as the precipitant, iron and sulfide
act as reducing agents for the hexavalent chromium according to
the reaction;
Cr03 + FeS + 3H20 > Fe(OH)3 + Cr(OH)3 + S
The sludge produced in this reaction consists mainly of ferric
hydroxides, chromic hydroxides, and various metallic sulfides.
Some excess hydroxyl ions are generated in this process, possibly
requiring a downward re-adjustment of pH.
Based on the available data, Table VII-6 (page 238) shows the
minimum reliably attainable effluent concentrations for sulfide
precipitation-sedimentation systems. These values are used to
calculate performance predictions of sulfide precipitation-
sedimentation systems.
Sulfide precipitation is used in many process and wastewater
treatment applications in nonferrous metals manufacturing. This
technology is used to treat process wastewater discharges from
cadmium recovery and to recover metals from zinc baghouse dusts
at a U.S. nonferrous metals manufacturing plant. Another plant
achieves complete recycle of electrolyte from copper refining
through removal of metal impurities via sulfide precipitation.
Primary tungsten is frequently separated from molybdenum via
sulfide precipitation. In secondary tin production, lead is
recovered from alkaline detinning solutions with sulfide
precipitation just prior to electrowinning. In the production of
beryllium hydroxide, sulfide precipitation is used to remove
metal impurities prior to precipitating beryllium hydroxide.
These demonstrations show that sulfide precipitation is in use in
the nonferrous metals manufacturing category that may present
equal or greater treatment difficulties as wastewater.
Sulfide precipitation also is used as a preliminary or polishing
treatment technology for nonferrous metals manufacturing
wastewater. A U.S. nonferrous metals manufacturing facility
specifically uses sulfide precipitation operated at a low pH to
remove specific toxic metals from the acid plant blowdown prior
to discharging the wastewater to a lime and settle treatment
system. Hydrogen sulfide is used to precipitate selenium.
Arsenic is also precipitated as arsenic sulfide. The arsenic and
selenium sulfides are removed in a plate and frame filter. EPA
sampling at this plant found three-day averages of arsenic and
selenium in the untreated acid plant blowdown of 4.74 mg/1 and
21.5 mg/1 of arsenic and selenium, respectively. Composite
samples of treated (sulfide precipitation and filtration) acid
plant blowdown collected during the EPA sampling visit showed
arsenic concentrations at 0.066, 0.348 and 0.472 mg/1. Likewise,
the treated acid plant blowdown samples contained selenium
concentrations at 0.015, 0.05, and 0.132 mg/1.
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
Performance data collected by personnel at this same plant over a
one-year time period (24 data points) indicate the long-term
arithmetic mean for arsenic is 1.2 mg/1. Selenium data gathered
at the same plant over one year (33 data points) show a
long-term arithmetic mean of 0.53 mg/1. The effluent data
submitted to the Agency are quite variable due to the methods
used to control reagent addition by the plant. In fact, there
is almost as much variability in the treated effluent from the
filter press as there is in the raw acid plant blowdown.
This is not characteristic of the well-operated treatment
systems where a significant reduction in variability of raw waste
loads is observed. Hydrogen sulfide is added to the acid plant
blowdown based on flow rate, not influent concentration, EPA
sampling data demonstrate that slight increases in influent
arsenic concentration also produce similar increases in
effluent arsenic concentrations. This is characteristic
of a system in which treatment reagents are not being added
in sufficient quantities. The Agency believes more uniform
performance would be achieved if sulfide addition were
properly controlled using a specific ion electrode. This method
of control is demonstrated in sulfide treatment to recover silver
from photographic solutions. In this way, excess sulfide is
consistently added to ensure proper precipitation of arsenic and
selenium sulfides.
While the average for arsenic from this plant is 1.2 mg/1, the
system as operated was able to achieve concentrations as low as
0.04 mg/1. Likewise, for selenium, concentrations as low as 0.01
mg/1 were achieved. The Agency recognizes that it is unlikely
that plants could consistently achieve 0.04 mg/1 and 0.01 mg/1,
respectively; however, this performance indicates that through
proper control of reagent addition the plant would vastly improve
the performance.
Data are also available from a Swedish copper and lead smelter
that operates a full-scale sulfide precipitation and hydroxide
precipitation unit on acid plant blowdown, storm water, and
facility cleaning wastewaters. The full-scale sulfide-
hydroxide precipitation plant was started up in May 1978 and has
operated since that time. The plant personnel compared
hydroxide and sulfide precipitation for removal of toxic metals
at the bench scale prior to design of the full-scale plant. On
the basis of laboratory data, they determined that a combined
sulfide-hydroxide process would be best. This approach resulted
in the best overall removals and yielded a sludge that could be
recycled into the smelting process.
This Swedish plant operates the sulfide precipitation portion of
the process at a pH in the range of 3 to 5 standard units. This
results in good copper, lead, and zinc removals as well as some
reduction of arsenic and selenium. This mode of operation was
selected to yield a sludge containing copper and lead sulfides
that could be reintroduced readily into the smelter furnaces.
Arsenic concentrations as low as 1.9 mg/1 were achieved even in
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
this mode which is not optimized for arsenic removal.
There is a Japanese copper smelter with a metallurgical acid
plant that operates a sulfide precipitation and filtration
preliminary treatment system. The plant uses sulfide to treat'
acid plant blowdown containing arsenic concentrations of 8,530
mg/1, copper at 120 mg/1, lead at 30 mg/lr copper at 120 mg/1,
lead at 30 mg/1 and cadmium at 60 mg/1. The filtrate from this
treatment system typically contains concentrations of 0.03 mg/1
for arsenic, 0,03 mg/1 for copper, 0,5 mg/1 for lead and 0.3 mg/1
for cadmium. Wastewater from the acid plant is pumped from the
acid plant to a 50-cubic-meter stirred reaction tank where
sodium hydrosulfide is added. Completion of the
precipitation reaction is measured by a oxidation-reduction
potentiometer. After the reaction is complete the wastewater is
pumped to a filter press to separate the precipitated solids from
solution. The filtrate is pumped for additional wastewater
treatment downstream.
EPA also conducted bench-scale tests to determine the
effectiveness of sulfide precipitation on metallurgical
acid plant discharges. Wastewater samples were collected
from a U.S. copper smelter and refinery with a
metallurgical acid plant on site. The U.S. plant did not have
raw wastewater arsenic concentrations as high as those of the
Japanese plant; however, the arsenic concentrations from the U.S.
facility have been observed to range from 50-150 mg/1.
Bench-scale tests were conducted using sulfide precipitation and
filtration preliminary treatment in the same way as the
full-scale Japanese plant. At a pH of 1.5 standard units with
excess sodium sulfide, an arsenic concentration of 1.5 mg/1 was
achieved with this preliminary treatment. The fact that the
concentration achieved for arsenic in the bench-scale tests is
higher (1.5 mg/1 as opposed to 0.03 mg/1) than that observed in
the full-scale Japanese facility is not unexpected. The purpose
of the bench-scale tests was to demonstrate that effective
removal of arsenic was possible. These operating conditions were
not optimized as they were in the_ full-scale facility. The
bench-scale tests are described in greater detail in a report
entitled Laboratory Studies on Sulfide Precipitation Applied to
Metallurgical Acid Plant Wastewaters, found in the record
supporting this rulemaking.
Sulfide precipitation may also be applied following or in
conjunction with hydroxide precipitation (two-stage
treatment-lime followed by sulfide). In these applications
sulfide precipitation acts to further reduce toxic metal
concentrations. Responses to Section 308 data collection
portfolios indicate that there are four nonferrous metals
manufacturing plants using sulfide precipitation as a polishing
step - two primary zinc and two secondary silver plants.
EPA conducted bench-scale tests to examine the effectiveness of
sulfide precipitation used in conjunction with lime precipitation
and following lime and settle treatment. Sulfide precipitation
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
used in conjunction with lime precipitation applied to wastewater
from a primary sine process wastewater containing 1.4 mg/1 of
arsenic, 15 mg/1 of cadmium, 7 mg/1 of copper, 5 mg/1 of lead and
114 mg/1 of zinc, achieved effluent concentrations of 0,04 mg/1
of arsenic, 0.05 mg/1 of cadmium, 0.038 mg/1 of copper, 0.027
mg/1 of lead and 0.31 mg/1 of zinc. Sulfide precipitation
applied as a polishing step after lime precipitation achieved
0.04 mg/1 of arsenic, 0.004 mg/1 of cadmium, 0.014 mg/1 of
copper, 0.003 mg/1 of lead and 0.036 mg/1 of zinc when treating
the same process wastewater.
Carbonate precipitation is sometimes used to precipitate metals,
especially where precipitated metals values are to be recovered.
The solubility of most metal carbonates is intermediate between
hydroxide and sulfide solubilities; in addition, carbonates form
easily filtered precipitates. Carbonate ions appear to be
particularly useful in precipitating lead and antimony. Sodium
carbonate has been observed being added at treatment to improve
lead precipitation and removal in some industrial plants. The
lead hydroxide and lead carbonate solubility curves displayed in
Figure VII-3 (page 256) (Source; "Heavy Metals Removal," by
Kenneth Lanovette, Chemical Engineering/Deskbook Issue, October
17, 1977) explain this phenomenon,
Co-precipitation With Iron, The presence of substantial
quantities of iron in metal-bearing wastewaters before
treatment has been shown to improve the removal of toxic
metals. In some cases this iron is an integral part of the
industrial wastewater? in other cases iron is deliberately
added as a preliminary treatment or first step of
treatment. The iron functions to improve toxic and other metals
(such as molybdenum) removal by three mechanisms: the iron
co-precipitates with toxic metals forming a stable precipitate
which desolubilizes the tox ic metal; the iron
improves the settleability of the precipitate; and the
large amount of iron reduces the fraction of toxic
metal in the precipitate. Co-precipitation with iron has
been practiced for many years incidentally when iron was
a substantial constituent of raw wastewater and intentionally
when iron salts were added as a coagulant aid. Aluminum
or mixed iron-aluminum salt also have been used.
Co-precipitation using large amounts of ferrous iron salts is
known as ferrite co-precipitation because magnetic iron oxide or
ferrite is formed. The addition of ferrous salts (sulfate) is
followed by alkali precipitation and air oxidation. The
resultant precipitate is easily removed by filtration and may be
removed magnetically. Data illustrating the performance of
ferrite co-precipitation is shown in Table VII-7, (page 239).
Removal of PAH
EPA and its contractor conducted a series of bench- and pilot-
scale tests examining the effectiveness of removing polynuclear
aromatic hydrocarbons (PAH) from primary aluminum smelting
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
potline wet air pollution control wastewater. In the study, the
effectiveness of lime and settle, multimedia filtration and
activated carbon adsorption was examined. The study demonstrated
that PAH commonly found in potline wet air pollution control
wastewater can be removed by lime and settle technology. PAH
present in the untreated potline scrubber liquor at
concentrations ranging from 0.030 to 2.740 mg/1 were reduced to
less than 0.170 mg/1 (ND to 0.170 mg/1) by lime and settle
treatment,
Advantages and Limitations. Chemical precipitation has proved to
be an effective technique for removing many pollutants from
industrial wastewater. It operates at ambient conditions and is
well suited to automatic control. The use of chemical
precipitation may be limited because of interference by chelating
agents, because of possible chemical interference with mixed
wastewaters and treatment chemicals, or because of the
potentially hazardous situation involved with the storage and
handling of those chemicals. Nonferrous metals
manufacturing wastewaters do not normally contain chelating
agents or complex pollutant matrix formations which would
interfere with or limit the use of chemical precipi tation.
One exception to this statement is wastewaters generated by
secondary precious metals facilities. These wastewaters are
expected to contain metal complexes which may require lime
or sulfide addition to help overcome complexing effects.
Lime is usually added as a slurry when used in hydroxide
precipitation. The slurry must be kept well mixed and the
addition lines periodically checked to prevent blocking which
may result from a build-up of solids. Also, lime
precipitation usually makes recovery of the precipitated
metals difficult, because of the heterogeneous nature of
most lime sludges.
The major advantage of the sulfide precipitation process is that
the extremely low solubility of most metal sulfides promotes very
high metal removal efficiencies; the sulfide process also has the
ability to remove chromates and dichromates without preliminary
reduction of the chromium to its trivalent state. In addition,
sulfide can precipitate metals complexed with most complexing
agents. The process demands care, however, in maintaining the pH
of the solution at approximately 10 in order to restrict the
generation of toxic hydrogen sulfide gas. For this
reason, ventilation of the treatment tanks may be a necessary
precaution in most installations. The use of insoluble sulfides
reduces the problem of hydrogen sulfide evolution. As with
hydroxide precipitation, excess sulfide ion must be present to
drive the precipitation reaction to completion. Since the
sulfide ion itself is toxic, sulfide addition must be carefully
controlled to maximize heavy metals precipitation with a
minimum of excess sulfide to avoid the necessity of
additional wastewater treatment. At very high excess
sulfide levels and high pH, soluble mercury-sulfide compounds
may also be formed. Where excess sulfide is present,
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
aeration of the effluent stream can aid in oxidizing residual
sulfide to the less harmful sodium sulfate (Na2S0<}) . The
cost of sulfide precipitants is high in comparison to hydroxide
precipitants, and disposal of metallic sulfide sludges may
pose problems. An essential element in effective sulfide
precipitation is the removal of precipitated solids from
the wastewater and proper disposal in an appropriate site.
Sulfide precipitation will also generate a higher volume of
sludge than hydroxide precipitation, resulting in higher
disposal and dewatering costs. This is especially true
when ferrous sulfide is used as the precipitant.
Sulfide precipitation may be used as a polishing treatment after
hydroxide precipitation-sedimentation. This treatment
configuration may provide the better treatment effectiveness of
sulfide precipitation while minimizing the variability caused by
changes in raw waste and reducing the amount of sulfide
precipitant required.
Operational Factors. Reliability: Alkaline chemical
precipitation is highly reliable, although proper monitoring and
control are required. Sulfide precipitation systems provide
similar reliability.
Maintainability: The major maintenance needs involve periodic
upkeep of monitoring equipment, automatic feeding equipment,
mixing equipment, and other hardware. Removal of accumulated
sludge is necessary for efficient operation of precipitation-
sedimentation systems.
Solid Waste Aspects: Solids which precipitate out are removed in
a subsequent treatment step. Ultimately, these solids require
proper disposal.
Demonstration Status. Chemical precipitation of metal hydroxides
is a classic waste treatment technology used by most industrial
waste treatment systems. Chemical precipitation of metals in the
carbonate form alone has been found to be feasible and is
commercially used to permit metals recovery and water reuse.
Full-scale commercial sulfide precipitation units are in
operation at numerous installations, including several plants in
the nonferrous metals manufacturing category. As noted earlier,
sedimentation to remove precipitates is discussed separately.
Use in Nonferrous Metals Manufacturing Plants: Hydroxide
chemical precipitation is used at 121 nonferrous metals
manufacturing plants. Sulfide precipitation is used in four
nonferrous metals manufacturing plants.
3. Cyanide Precipitation
Cyanide precipitation, although a method for treating cyanide in
wastewaters, does not destroy cyanide. The cyanide is retained
in the sludge that is formed. Reports indicate that during
exposure to sunlight, the cyanide complexes can break down and
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
form free cyanide. For this reason, the sludge from this
treatment method must be disposed of carefully.
Cyanide may be precipitated and settled out of wastewaters by the
addition of zinc sulfate or ferrous sulfate. In the presence of
iron, cyanide will form extremely stable cyanide complexes. The
addition of zinc sulfate or ferrous sulfate forms zinc
ferrocyanide or ferro ferricyanide complexes.
Cyanide precipitation occurs in two steps; react ion with ferrous
sulfate or zinc sulfate at an alkaline pH to form iron or zinc
cyanide complexes followed by reaction at a low pH with
additional ferrous sulfate to form insoluble iron cyanide
precipitates. Cyanide precipitation is applicable to all cyanide
containing wastewater and, unlike many oxidation technologies,
is not limited by the presence of complexed cyanides. The
oxidation technologies discussed later in this section are
applicable for waste streams containing only uncomplexed
cyanides. Cyanide precipitation has been selected as the
technology basis for cyanide control because of the presence of
iron, nickel, and zinc in wastewaters in this category. These
toxic metals are known to form stable complexes with cyanide.
Cyanide-containing wastewater is introduced into a mixing
chamber where ferrous sulfate (as the heptahydrate (FeS04.
7H2O)), is added to form a hexacyanoferrate complex. The
hexacyanoferrate complex is most stable at a pH of 9
(standard units). Thus, the complexation reaction is
performed at pH 9. The amount or dosage of ferrous sulfate
is dependent upon the chemical form of the cyanide in
the wastewater. Cyanide may be present in one of two
forms, free or complexed (sometimes referred to as fixed).
Various analytical methods to determine the portions of
free and complexed cyanides in wastewater are discussed in
the open literature. Free cyanide refers to the portion of
total cyanide that freely dissociates in water (e.g., HCN).
When ferrous sulfate is added to the wastewater at pH 9, the
ferrous ion readily oxidizes to the ferric ion. The complexation
step is then expected to occur as follows:
FeS04 + 6CN~ > Fe(CN)53~ + S04~" + C~
To a lesser degree, the free cyanide may also be complexed
according to;
FeS04 + 6CN~ > Fe(CN)64- + SO4
Complexed cyanide, present as the hexacyanoferrate or
metallocyanide complexes, is already in the desired chemical
form. In theory, the ferrous sulfate dosage is determined by
calculating the stoichiometric equivalent required for the free
cyanide present, that is, one mole of ferrous sulfate per six
moles of cyanide. In actual practice, the dosage requirements
are greater than the stoichiometric equivalent. One reason
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
that excess ferrous sulfate is required is that the
complexation reaction is very slow and the excess of reactants
increases the reaction rate. Another reason is that in treatment
systems, where lime or other sources of hydroxide ions are added
to raise the pH to 8, some of the lime will react with the
ferrous sulfate to form calcium sulfate.
After forming the complex, the wastewater is then mixed with
additional ferrous sulfate and the pH adjusted using acid
(e.g., H2S04) in the range of 2 to 4. The ferrous sulfate
reacts with the hexacyanoferrate to form ferrohexacyanoferrate,
according to;
3FeS04 + 2Fe(CN)g 3_ > Fe3{Pe(CN)6)2 + 3S04~~
2FeS04 + Fe(CN)g 4~ > Fe2(Fe(CN)6) + 2S04~~
It appears that it may also be possible to use ferric chloride in
the precipitation step, according to:
4FeC13 + 3Fe(CN6)4 > Fe4(Fe(CN)6)3 + 12C1"
However, based on data obtained from cyanide-bearing waters in
the primary aluminum industry, ferric chloride did not increase
the amount of cyanide precipitate formed. In wastewaters
obtained from two different facilities, the dosage of ferrous
sulfate was held constant while the dosage of ferric chloride was
varied. Results from both plants indicate that the addition of
ferric chloride has little, if any, effect on the precipitation
chemistry.
Following complexation the wastewater is introduced into a
clarifier to allow these insoluble precipitates to settle.
Sedimentation (settling) is discussed in a later subsection.
Adequate complexation of cyanide requires that the pH must be
kept at 9.0 and an appropriate retention time be maintained. A
study has shown that the formation of the complex is very
dependent on pH. At a pH of either 8 or 10, the residual cyanide
concentrations measured are twice that of the same reaction
carried out at a pH of 9. Removal efficiencies also depend
heavily on the retention time allowed. The formation of the
complexes takes place rather slowly. Depending upon the excess
amount of z inc sulfate or ferrous sulfate added, at least a 30
minute retention time should be allowed for the formation of the
cyanide complex before continuing on to the clarification stage.
One experiment with an initial concentration of 10 mg/1 of
cyanide showed that 98 percent of the cyanide was completed ten
minutes after the addition of ferrous sulfate at twice the
theoretical amount necessary. Interference from other metal
ions, such as cadmium, might result in the need for longer
retention times.
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
Table VI1-8 (page 239) presents cyanide precipitation data from
three coil coating plants, A fourth plant was visited for the
purpose of observing plant testing of the cyanide precipitation
system. Specific data from this facility are not
included because: (1) the pH was usually well below the optimum
level of 9.0; (2) the historical treatment data were not
obtained using the standard cyanide analysis procedure; and
(3) matched input-output data were not made available by the
plant. Scanning the available data indicates that the raw
waste CN level was in the range of 25.0; the pH 7.5; and treated
CN level was from 0.1 to 0.2.
The concentrations are those of the stream entering and leaving
the treatment system. Plant 1057 allowed a 27-minute retention
time for the formation of the complex. The retention time for
the other plants is not known. The data suggest that over a wide
range of cyanide concentration in the raw waste, the
concentration of cyanide can be reduced in the effluent stream to
under 0.15 mg/1.
Application and Performance. Cyanide precipitation can be used
when cyanide destruction is not feasible because of the presence
of cyanide complexes which are difficult to destroy. Effluent
concentrations of cyanide well below 0.15 mg/1 are possible.
Advantages and Limitations, Cyanide precipitation is an
inexpensive method of treating cyanide. Problems may occur when
metal ions interfere with the formation of the complexes.
^• Granular Bed Filtration
Filtration occurs in nature as surface and ground waters are
cleansed by sand. Silica sand, anthracite coal, and garnet are
common filter media used in water treatment plants. These are
usually supported by gravel. The media may be used singly or in
combination. The multi-media filters may be arranged to maintain
relatively distinct layers by virtue of balancing the forces of
gravity, flow, and buoyancy on the individual particles. This is
accomplished by selecting appropriate filter flow rates (gpm/sq-
ft), media grain size, and density.
Granular bed filters may be classified in terms of filtration
rate, filter media, flow pattern, or method of pressurization.
Traditional rate classifications are slow sand, rapid sand, and
high rate mixed media. In the slow sand filter, flux or
hydraulic loading is relatively low, and removal of collected
solids to clean the filter is therefore relatively infrequent.
The filter is often cleaned by scraping off the inlet face (top)
of the sand bed. In the higher rate filters, cleaning is
frequent and is accomplished by a periodic backwash, opposite to
the direction of normal flow.
A filter may use a single medium such as sand or diatomaceous
earth, but dual and mixed (multiple) media filters allow higher
flow rates and efficiencies. The dual media filter usually
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
consists of a fine bed of sand under a coarser bed of anthracite
coal. The coarse coal removes most of the influent solids, while
the fine sand performs a polishing function. At the end of the
backwash, the fine sand settles to the bottom because it is
denser than the coal, and the filter is ready for normal
operation. The mixed media filter operates on the same
principle, with the finer, denser media at the bottom and the
coarser, less dense media at the top. The usual arrangement is
garnet at the bottom (outlet end) of the bed, sand in the middle,
and anthracite coal at the top. Some mixing of these layers
occurs and is, in fact, desirable.
The flow pattern is usually top-to-bottom, but other patterns are
sometimes used. Upflow filters are sometimes used, and in a
horizontal filter the flow is horizontal. In a biflow filter,
the influent enters both the top and the bottom and exits
laterally. The advantage of an upflow filter is that with an
upflow backwash, the particles of a single filter medium are
distributed and maintained in the desired coarse-to-fine (bottom-
to-top) arrangement. The disadvantage is that the bed tends to
become fluidized, which ruins filtration efficiency. The biflow
design is an attempt to overcome this problem.
The classic granular bed filter operates by gravity flow;
however, pressure filters are fairly widely used. They permit
higher solids loadings before cleaning and are advantageous when
the filter effluent must be pressurized for further downstream
treatment. In addition, pressure filter systems are often less
costly for low to moderate flow rates.
Figure VI1-14 (page 267) depicts a high rate, dual media, gravity
downflow granular bed filter, with self-stored backwash. Both
filtrate and backwash are piped around the bed in an arrangement
that permits gravity upflow of the backwash, with the stored
filtrate serving as backwash. Addition of the indicated
coagulant and polyelectrolyte usually results in a substantial
improvement in filter performance.
Auxiliary filter cleaning is sometimes employed in the upper few
i nches of filter beds. This is conventionally refer red to as
surface wash and is accomplished by water jets just below the
surface of the expanded bed during the backwash cycle. These
jets enhance the scouring action in the bed by increasing the
agi tat ion.
An important feature for successful filtration and backwashing is
the underdrain. This is the support structure for the bed. The
underdrain provides an area for collection of the filtered water
without clogging from either the filtered solids or the media
grains. In addition, the underdrain prevents loss of the media
with the water, and during the backwash cycle it provides even
flow distribution over the bed. Failure to dissipate the
velocity head during the filter or backwash cycle will result in
bed upset and the need for major repairs.
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Several standard approaches are employed for filter underdrains.
The simplest one consists of a parallel porous pipe embedded
under a layer of coarse gravel and manifolded to a header pipe
for effluent removal. Other approaches to the underdrain system
are known as the Leopold and Wheeler filter bottoms. Both of
these incorporate false concrete bottoms with specific porosity
configurations to provide drainage and velocity head dissipation.
Filter system operation may be manual or automatic. The filter
backwash cycle may be on a timed basis, a pressure drop basis
with a terminal value which triggers backwash, or a solids carry-
over basis from turbidity monitoring of the outlet stream. All
of these schemes have been used successfully.
AfiEilcatioil Performance. Wastewater treatment plants often
use granular bed filters for polishing after clarification,
sedimentation, or other similar operations. Granular bed
filtration thus has potential application to nearly all
industrial plants. Chemical additives which enhance the upstream
treatment equipment may or may not be compatible with or enhance
the filtration process. Normal operating flow rates for various
types of filters are:
Slow Sand 2.04 -
Rapid Sand 40.74 -
High Rate Mixed Media
5.30 1/sq m-hr
51.48 1/sq m-hr
81.48 - 122.22 1/sq m-hr
Suspended solids are commonly removed from wastewater streams by
filtering through a deep 0.3-0.9 m (1-3 feet) granular filter
bed. The porous bed formed by the granular media can be designed
to remove practically all suspended particles. Even colloidal
suspensions (roughly 1 to 100 microns) are adsorbed on the
surface of the media grains as they pass in close proximity in
the narrow bed passages.
Properly operated filters following some pretreatment to reduce
suspended solids below 200 mg/1 should produce water with less
than 10 mg/1 TSS. For example, multimedia filters produced the
effluent qualities shown in Table VII-9 (page 240).
The addition of multimedia filtration to lime precipitation and
sedimentation resulted in further reduction of the PAH; all less
than 0.110 mg/1. Benzo(a)pyrene was reduced to the analytical
quantification limit of 0.010 mg/1. The study conducted on
potline scrubber liquor is discussed more fully in Section VII of
the primary aluminum subcategory supplement and in a report
entitled Physical-Chemical Treatment of Aluminum Plant Potline
Scrubber Wastewater, found in the record supporting this rule.
Advantages and Limitations. The principal advantages of granular
bed filtration are its comparatively (to other filters) low
initial and operating costs, reduced land requirements over other
methods to achieve the same level of solids removal, and
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
elimination of chemical additions to the discharge stream.
However, the filter may require pretreatment if the solids level
is high (over 100 rag/1). Operator training must be somewhat
extensive due to the controls and periodic backwashing involved,
and backwash must be stored and dewatered for economical
disposal.
Operational Factors. Reliability: The recent improvements in
filter technology have significantly improved filtration
reliability. Control systems# improved designs, and good
operating procedures have made filtration a highly reliable
method of water treatment.
Maintainability: Deep bed filters may be operated with either
manual or automatic backwash. In either case, they must be
periodically inspected for media attrition, partial plugging, and
leakage. Where backwashing is not used, collected solids must be
removed by shoveling, and filter media must be at least partially
replaced.
Solid Waste Aspects: Filter backwash is generally recycled
within the wastewater treatment system, so that the solids
ultimately appear in the clarifier sludge stream for subsequent
dewatering. Alternatively, the backwash stream may be dewatered
directly or, if there is no backwash, the collected solids may be
disposed of in a suitable landfill. In either of these
situations there is a solids disposal problem similar to that of
clarifiers.
Demonstration Status. Deep bed filters are in common use in
municipal treatment plants. Their use in polishing industrial
clarifier effluent is increasing, and the technology is proven
and conventional. Granular bed filtration is used in 25
nonferrous metals manufacturing plants. As noted previously,
however, little data is available characterizing the
effectiveness of filters presently in use within the industry.
5. Pressure Filtration
Pressure filtration works by pumping the liquid through a filter
material which is impenetrable to the solid phase. The positive
pressure exerted by the feed pumps or other mechanical means
provides the pressure differential which is the principal driving
force. Figure VI1-15 (page 268) represents the operation of one
type of pressure filter.
A typical pressure filtration unit consists of a number of plates
or trays which are held rigidly in a frame to ensure alignment
and which are pressed together between a fixed end and a
traveling end. On the surface of each plate, a filter made of
cloth or synthetic fiber is mounted. The feed stream is pumped
into the unit and passes through holes in the trays along the
length of the press until the cavities or chambers between the
trays are completely filled. The solids are then entrapped, and
a cake begins to form on the surface of the filter material. The
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water passes through the fibers, and the solids are retained.
At the bottom of the trays are drainage ports. The filtrate is
collected and discharged to a common drain. As the filter medium
becomes coated with sludge, the flow of filtrate through the
filter drops sharply, indicating that the capacity of the filter
has been exhausted. The unit must then be cleaned of the sludge.
After the cleaning or replacement of the filter media, the unit
is again ready for operation.
Application and Performance. Pressure filtration is used in
nonferrous metals manufacturing for sludge dewatering and also
for direct removal of precipitated and other suspended solids
from wastewater. Because dewatering is such a common operation
in treatment systems, pressure filtration is a technique which
can be found in many industries concerned with removing solids
from their waste stream.
In a typical pressure filter, chemically preconditioned sludge
detained in the unit for one to three hours under pressures
varying from 5 to 13 atmospheres exhibited final solids content
between 25 and 50 percent.
Advantages and Limitations¦ The pressures which may be applied
to a sludge for removal of water by filter presses that are
currently available range from 5 to 13 atmospheres. As a result,
pressure filtration may reduce the amount of chemical
pretreatment required for sludge dewatering. Sludge retained in
the form of the filter cake has a higher percentage of solids
than that from centrifuge or vacuum filter. Thus, it can be
easily accommodated by materials handling systems.
As a primary solids removal technique, pressure filtration
requires less space than clarification and is well suited to
streams with high solids loadings. The sludge produced may be
disposed without further dewatering, but the amount of sludge is
increased by the use of filter precoat materials (usually
diatomaceous earth). Also, cloth pressure filters often do not
achieve as high a degree of effluent clarification as clarifiers
or granular media filters.
Two disadvantages associated with pressure filtration in the past
have been the short life of the filter cloths and lack of
automation. New synthetic fibers have largely offset the first
of these problems. Also, units with automatic feeding and
pressing cycles are now available.
For larger operations, the relatively high space requirements, as
compared to those of a centrifuge, could be prohibitive in some
si tuat ions,
Operational Factors. Reliability: With proper pretreatment,
design, and control, pressure filtration is a highly dependable
system.
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
pretreatment. The site of flocculant or coagulant addition also
may significantly influence the effectiveness of clarification.
If the flocculant is subjected to too much mixing before entering
the clarifier, the complexes may be sheared and the settling
effectiveness diminished. At the same time, the flocculant must
have sufficient mixing and reaction time in order for effective
set-up and settling to occur. Plant personnel have observed that
the line or trough leading into the clarifier is often the most
efficient site for flocculant addition. The performance of
simple settling is a function of the movement rate, particle
size and density, and the surface area of the basin.
The data displayed in Table VII-10 (page 240) indicate suspended
solids removal efficiencies in settling systems.
The mean effluent TSS concentration obtained by the plants shown
in Table VII-10 is 10.1 mg/1. Influent concentrations averaged
838 mg/1. The maximum effluent TSS value reported is 23 mg/1.
These plants all use alkaline pH adjustment to precipitate metal
hydroxides, and most add a coagulant or flocculant prior to
settling.
Advantages and Limi tations. The major advantage of simple
settling is its simplicity as demonstrated by the gravitational
settling of solid particulate waste in a holding tank or lagoon.
The major problem with simple settling is the long retention time
necessary to achieve complete settling, especially if the
specific gravity of the suspended matter is close to that of
water. Some materials cannot be practically removed by simple
settling alone.
Settling performed in a clarifier is effective in removing slow-
settling suspended matter in a shorter time and in less space
than a simple settling system. Also, effluent quality is often
better from a clarifier. The cost of installing and maintaining
a clarifier, however, is substantially greater than the costs
associated with simple settling.
Inclined plate, slant tube, and lamella settlers have even higher
removal efficiencies than conventional clarifiers, and greater
capacities per unit area are possible. Installed costs for these
advanced clarification systems are claimed to be one half the
cost of conventional systems of similar capacity.
Operational Factors. Reliability: Settling can be a highly
reliable technology for removing suspended solids. Sufficient
retention time and regular sludge removal are important factors
affecting the reliability of all settling systems. Proper
control of pH adjustment, chemical precipitation, and coagulant
or flocculant addition are additional factors affecting settling
efficiencies in systems (frequently clarifiers) where these
methods are used.
Those advanced settlers using slanted tubes, inclined plates, or
a lamellar network may require pre-screening of the waste in
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
order to eliminate any fibrous materials which could potentially
clog the system. Some installations are especially vulnerable to
shock loadings, as from storm water runoff, but proper system
design will prevent this.
Maintainability: When clarifiers or other advanced settling
devices are used, the associated system utilized for chemical
pretreatment and sludge dragout must be maintained on a regular
basis. Routine maintenance of mechanical parts is also
necessary. Lagoons require little maintenance other than
periodic sludge removal.
Demonstration Status. Settling represents the typical method of
solids removal and is employed extensively in industrial waste
treatment. The advanced clarifiers are just beginning to appear
in significant numbers in commercial applications.
7. Skimming
Pollutants with a specific gravity less than water will often
float unassisted to the surface of the wastewater. Skimming
removes these floating wastes. Skimming normally takes place in
a tank designed to allow the floating debris to rise and remain
on the surface, while the liquid flows to an outlet located below
the floating layer. Skimming devices are therefore suited to the
removal of non-emulsified oils from raw waste streams. Common
skimming mechanisms include the rotating drum type, which picks
up oil from the surface of the water as it rotates. A doctor
blade scrapes oil from the drum and collects it in a trough for
disposal or reuse. The water portion is allowed to flow under
the rotating drum. Occasionally, an underflow baffle is
installed after the drum; this has the advantage of retaining any
floating oil which escapes the drum skimmer. The belt type
skimmer is pulled vertically through the water, collecting oil
which is scraped off from the surface and collected in a drum.
Gravity separators, such as the API type, utilize overflow and
underflow baffles to skim a floating oil layer from the surface
of the wastewater. An overflow-underflow baffle allows a small
amount of wastewater (the oil portion) to flow over into a trough
for disposition or reuse while the majority of the water flows
underneath the baffle. This is followed by an overflow baffle,
which is set at a height relative to the first baffle such that
only the oil bearing portion will flow over the first baffle
during normal plant operation. A diffusion device, such as a
vertical slot baffle, aids in creating a uniform flow through the
system and in increasing oil removal efficiency.
Application and Performance. Oil skimming is used in nonferrous
metals manufacturing to remove free oil and grease used as
lubricants in some types of metal casting. Another source of oil
is lubricants for drive mechanisms and other machinery contacted
by process water. Skimming is applicable to any waste stream
containing pollutants which float to the surface. It is commonly
used to remove free oil, grease, and soaps. Skimming is often
used in conjunction with air flotation or clarification in order
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to increase its effectiveness.
The removal efficiency of a skimmer is partly a function of the
retention time of the water in the tank. Larger, more buoyant
particles require less retention time than smaller particles.
Thus, the efficiency also depends on the composition of the waste
stream. The retention time required to allow phase separation
and subsequent skimming varies from 1 to 15 minutes, depending on
the wastewater characteristics.
API or other gravity-type separators tend to be more suitable for
use where the amount of surface oil flowing through the system is
consistently significant. Drum and belt type skimmers are
applicable to waste streams which evidence smaller amounts of
floating oil and where surges of floating oil are not a problem.
Using an API separator system in conjunction with a drum type
skimmer would be a very effective method of removing floating
contaminants from non-emulsified oily waste streams. Sampling
data shown in Table VII-11 (page 241) illustrate the capabilities
of the technology with both extremely high and moderate oil
influent levels.
These data are intended to be illustrative of the very high level
of oil and grease removals attainable in a simple two-step oil
removal system. Based on the performance of installations in a
variety of manufacturing plants and permit requirements that are
consistently achieved, it is determined that effluent oil levels
may be reliably reduced below 10 mg/1 with moderate influent
concentrations. Very high concentrations of oil such as the 22
percent shown above may require two-step treatment to achieve
this level.
Skimming which removes oil may also be used to remove base levels
of organics. Plant sampling data show that many organic
compounds tend to be removed in standard wastewater treatment
equipment. Oil separation not only removes oil but also organics
that are more soluble in oil than in water. Clarification
removes organic solids directly and probably removes dissolved
organics by adsorption on inorganic solids.
The source of these organic pollutants is not always known with
certainty, although in metal forming operations they seem to
derive mainly from various process lubricants. They are also
sometimes present in the plant water supply, as additives to
proprietary formulations of cleaners, or as the result of
leaching from plastic lines and other materials.
High molecular weight organics in particular are much more
soluble in organic solvents than in water. Thus they are much
more concentrated in the oil phase that is skimmed than in the
wastewater. The ratio of solubilities of a compound in oil and
water phases is called the partition coefficient. The logarithm
of the partition coefficients for selected polynuclear aromatic
hydrocarbon (PAH) and other toxic organic compounds in octanol
and water are shown in Table VI1-12 (page 241).
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A review of priority organic compounds commonly found in metal
forming operation waste streams indicated that incidental removal
of these compounds often occurs as a result of oil removal or
clarification processes. When all organics analyses from visited
plants are considered, removal of organic compounds by other
waste treatment technologies appears to be marginal in many
cases. However, when only raw waste concentrations of 0.05 mg/1
or greater are considered, incidental organics removal becomes
much more apparent. Lower values, those less than 0.05 mg/1,
are much more subject to analytical variation, while higher
values indi-cate a significant presence of a given compound. When
these factors are taken into account, analysis data indicate that
most clarification and oil removal treatment systems remove
significant amounts of the toxic organic compounds present in the
raw waste. The API oil-water separation system performed notably
in this regard, as shown in Table VII-13 (page 242).
Data from five plant days demonstrate removal of organics by the
combined oil skimming and settling operations performed on coil
coating wastewaters. Days were chosen where treatment system
influent and effluent analyses provided paired data points for
oil and grease and the organics present. All organics found at
quantifiable levels on those days were included. Further, only
those days were chosen where oil and grease raw wastewater
concentrations exceeded 10 mg/1 and where there was reduction in
oil and grease going through the treatment system. All plant
sampling days which met the above criteria are included below.
The conclusion is that when oil and grease are removed, organics
also are removed.
Percent Removal
Plant-Day
Oil & Grease
Organics
1054-3
95.9
98. 2
13029-2
98.3
78.0
13029-3
95.1
77 .0
38053-1
96.8
81. 3
38053-2
98.5
86.3
Mean
96.9
84.2
The unit operation most applicable to removal of trace priority
organics is adsorption, and chemical oxidation is another
possibility. Biological degradation is not generally applicable
because the organics are not present in sufficient concentration
to sustain a biomass and because most of the organics are
resistant to biodegradation.
Advantages and Limitations, Skimming as a pretreatment is
effective in removing naturally floating waste material. It also
improves the performance of subsequent downstream treatments.
Many pollutants, particularly dispersed or emulsified oil, will
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
not float "naturally" but require additional treatments. There-
fore, skimming alone may not remove all the pollutants capable of
being removed by air flotation or other more sophisticated
technologies.
Operational Factors. Reliability: Because of its simplicity,
skimming is a very reliable technique.
Maintainability: The skimming mechanism requires periodic
lubrication, adjustment, and replacement of worn parts.
Solid Waste Aspects; The collected layer of debris must be
disposed of by contractor removal, landfill, or incineration.
Because relatively large quantities of water are present in the
collected wastes, incineration is not always a viable disposal
method.
Demonstration Status. Skimming is a common operation utilized
extensively by industrial waste treatment systems. Oil skimming
is used in four nonferrous metals manufacturing plants.
MAJOR TECHNOLOGY EFFECTIVENESS
The performance of individual treatment technologies was
presented above. Performance of operating systems is discussed
here. Two different systems are considered: L&S (hydroxide
precipitation and sedimentation or lime and settle) and LS&F
(hydroxide precipitation, sedimentation, and filtration or lime,
settle, and filter). Subsequently, an analysis of effectiveness
of such systems is made to develop one-day maximum, ten-day and
thirty-day average concentration levels to be used in
regulating pollutants. Evaluation of the L&S and the LS&F
systems is carried out on the assumption that chemical reduction
of chromium, cyanide precipitation and oil removal are installed
and operating properly where appropriate.
L&S Performance -- Combined Metals Data Base
A data base known as the "combined metals data base" (CMDB) was
used to determine treatment effectiveness of lime and settle
treatment for certain pollutants. The CMDB was developed over
several years and has been used in a number of regulations.
During the development of coil coating and other categorical
effluent limitations and standards, chemical analysis data were
collected of raw wastewater (treatment influent) and treated
wastewater (treatment effluent) from 55 plants (126 data days)
sampled by EPA (or its contractor) using EPA sampling and
chemical analysis protocols. These data are the initial data
base for determining the effectiveness of L&S technology in
treating nine pollutants. Each of the plants in the initial data
base belongs to at least one of the following industry
categories: aluminum forming, battery manufacturing, coil coating
(including canraaking), copper forming, electroplating and
porcelain enameling. All of the plants employ pH adjustment and
hydroxide precipitation using lime or caustic, followed by
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Stokes' law settling (tank, lagoon or clarif ier) for solids
removal. An analysis of this data was presented in the
development documents for the proposed regulations for coi1
coating and porcelain enameling (January 1981). Prior to
analyzing the data, some values were deleted from the data base.
These deletions were made to ensure that the data reflect
properly operated treatment systems. The following criteria were
used in making these deletions:
Plants where malfunctioning processes or treatment systems
at the time of sampling were identified.
Data days where pH was less than 7.0 for extended periods
of time or TSS was greater than 50 mg/1 (these are
prima facie indications of poor operation).
In response to the coil coating and porcelain enameling
proposals, some commenters claimed that it was inappropriate to
use data from some categories for regulation of other categories.
In response to these comments, the Agency reanalyzed the data.
An analysis of variance was applied to the data for the 126 days
of sampling to test the hypothesis of homogeneous plant mean raw
and treated effluent levels across categories by pollutant. This
analysis is described in the report "A Statistical Analysis of
the Combined Metals Industries Effluent Data" which is in the
administrative record supporting this rulemaking. Homogeneity is
the absence of statistically discernible differences among the
categories, while heterogeneity is the opposite (i.e., the
presence of statistically discernible differences). The
main conclusion drawn from the analysis of variance is that, with
the exception of electroplating, the categories included in the
data base are generally homogeneous with regard to mean
pollutant concentrations in both raw and treated effluent.
That is, when data from electroplating facilities are included in
the analysis, the hypothesis of homogeneity across categories
is rejected. When the electroplating data are removed from,
the analysis the conclusion changes substantially and the
hypothesis of homogeneity across categories is not rejected.
On the basis of this analysis, the electroplating data were
removed from the data base used to determine limitations for the
final coil coating, porcelain enameling, copper forming,
aluminum forming, battery manufacturing, nonferrous metals
manufacturing, nonferrous metals forming, and canmaking
regulations.
Analytical data from nonferrous metals manufacturing treatment
systems which include paired raw waste influent treatment
and treated effluent are limited to nine plants with lime
precipitation and sedimentation systems. Three of these
systems were deemed to be inappropriate for consideration
in establishing treatment effectiveness concentration for
nonferrous metals manufacturing. Two of the plants had large
non-scope flows entering the treatment system and the third had
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
high TSS (N 1000 mg/1) concentrations at the outfall of its lime
and settle treatment system; concentrations indicative of poor
system operation. The treated data from six of these nine
nonferrous metals manufacturing plants with properly operated
lime precipitation and sedimentation systems were compared to the
achievable concentrations derived using the combined metals data
base. These data generally supported the combined metals data
base concentrations. These data and the analysis performed using
the data are in the administrative record supporting this
rulemaking.
EPA examined the homogeneity among nonferrous metals
manufacturing subcategories, as well as across the
combined metals data base. Homogeneity is the absence of
statistically discernible differences among mean untreated
pollutant concentrations observed in a set of data. The purpose
of these analyses was to corroborate the Agency's engineering
judgment that the untreated wastewater characteristics
observed in the nonferrous category were similar to those
observed in the combined metals data. Establishment of
similarity of raw wastes through a statistical assessment
provides further support to EPA's assumption that lime and
settle treatment reduces the toxic metal pollutant concentrations
in untreated nonferrous metals manufacturing wastewater to
concentrations achieved by the same technology applied to the
wastewater from the categories in the combined metals data
base. In general, the results of the analysis showed that the
nonferrous subcategories are homogeneous with respect to mean
pollutant concentrations across subcategories. Comparison
of the untreated nonferrous metals manufactur ing data
combined across subcategories and the combined metals data
also showed good agreement.
The homogeneity observed among the nonferrous untreated data and
the combined metals data supports the hypothesis of similar
untreated wastewater characteristics and suggests that lime and
settle treatment would reduce the concentrations of toxic
metal pollutants in the nonferrous metals manufacturing to
concentrations comparable to those achievable by lime and settle
treatment of wastewater from the categories included in the
combined metals data base.
There were several exceptions to the general finding of
homogeneity among the industrial categories discussed above. The
exceptional cases include:
1. Primary aluminum - cathode reprocessing wastewater and
potline wet air pollution control wastewater commingled with
cathode reprocessing wastewater.
2. Primary lead, zinc, and metallurgical acid plants - all
process wastewater.
3. The primary beryllium subcategory has higher beryllium
concentrations in the uncreated wastewater than other plants in
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phase II.
4. The secondary precious metals subcategory has higher zinc
concentrations in the untreated wastewater than other plants in
phase II.
5. The untreated nickel concentrations in specific secondary
tungsten and cobalt plants are higher than in the plants in the
combined metals data base.
These first two special cases are discussed later in this
section.
EPA is considering the use of sulfide precipitation in
conjunction with lime and settle, and lime, settle and filtration
for these three latter cases where the influent metals
concentrations are higher than those observed in the combined
metals data base. These special cases are discussed in a
memorandum entitled "Analysis of the Wastewater Pollutant
Concentrations from the Phase II Subcategories of the
Nonferrous Metals Manufacturing Category," found in the record
supporting this rulemaking. The combined metals data base as
discussed below is applicable to all nonferrous metals
manufacturing wastewater as demonstrated by the homogeneity.
Properly operated hydroxide precipitation and sedimentation will
result in effluent concentrations that are directly related to
pollutant solubilities. Since the nonferrous metals
manufacturing raw wastewater matrix contains the same toxic
pollutants in the same order of magnitude as the combined metals
data base, the treatment process effluent long-term performance
and variability will be quite similar. In addition,
interfering properties (such as chelating agents) usually do
not exist in nonferrous metals manufacturing wastewater
that would interfere with metal precipitation and so
prevent attaining concentrations calculated from the combined
metals data base.
It should be noted, however, that statistical analyses indicate
that the raw wastewater matrix in nonferrous metals manufacturing
contains higher concentrations of lead and cadmium than the raw
wastewater of plants used for the combined metals data base.
Because the precipitation (and ultimate removal by sedimentation)
of these metals is directly related to their solubility, EPA
believes that the differences in raw waste concentrations, while
statistically significant, are not large enough to alter the
achievable concentrations following treatment.
The statistical analysis provides support for the technical
engineering judgment that electroplating wastewaters
are sufficiently different from the wastewaters of other
industrial categories in the data base to warrant removal of
electroplating data from the data base used to
determine treatment effectiveness.
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For the purpose of determining treatment effectiveness,
additional data were deleted from the data base. These
deletions were made, almost exclusively, in cases where
effluent data points were associated with low influent values.
This was done in two steps. First, effluent values measured on
the same day as influent values that were less than or equal to
0.1 mg/1 were deleted. Second, the remaining data were
screened for cases in which all influent values at a plant were
low although slightly above the 0.1 mg/1 value. These
data were deleted not as individual data points but as plant
clusters of data that were consistently low and thus not
relevant to assessing treatment. A few data points were
also deleted where malfunctions not previously identified
were recognized. The data basic to the CMDB are displayed
graphically in Figures VI1-4 to 12 (Pages 257 to 265).
After all deletions, 148 data points from 19 plants remained.
These data were used to determine the concentration basis of
limitations derived from the CMDB used for the proposed
nonferrous metals manufacturing regulations.
The CMDB was reviewed following its use in a number of proposed
regulations (including nonferrous metals manufacturing).
Comments pointed out a few errors in the data and the Agency's
review identified a few transcr iption errors and some data points
that were appropriate for inclusion in the data that had not been
used previously because of errors in data record identification
numbers. Documents in the record of this rulemaking identify all
the changes, the reasons for the changes, and the effect of these
changes on the data base. Comments on other proposed regulations
asserted that the data base was too small and that the
statistical methods used were overly complex. Responses to
specific comments are provided in a document included in the
record of this rulemaking. The Agency believes that the data
base is adequate to determine effluent concentrations achievable
with lime and settle treatment. The statistical methods employed
in the analysis are well known and appropriate statistical
references are provided in the documents in the record that
describe the analysis.
The revised data base was re-examined for homogeneity.
The earlier conclusions were unchanged. The categories show
good overall homogeneity with respect to concentrations of the
nine pollutants in both raw and treated wastewaters with the
exception of electroplating.
The same procedures used in developing limitations for
nonferrous metals manufacturing from the combined metals data
base were then used on the revised data base. That is,
certain effluent data associated with low influent values were
deleted, and then the remaining data were fit to a lognormal
distribution to determine limitations values. The deletion of
data was done in two steps. First, effluent values measured on
the same day as influent values that were less than or equal to
0.1 mg/1 were deleted. Second, the remaining data were screened
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
for cases in which all influent values at a plant were low
although slightly above the 0.1 mg/1 value. These data were
deleted not as individual data points but as plant clusters of
data that were consistently low and thus not relevant to
assessing treatment.
One-day Effluent Values
The basic assumption underlying the determination of treatment
effectiveness is that the data for a particular pollutant are
lognormally distributed by plant. The lognormal has been found
to provide a satisfactory fit to plant effluent data in a number
of effluent guidelines categories and there was no evidence that
the lognormal was not suitable in the case of the CMDB. Thus, we
assumed measurements of each pollutant from a particular plant,
denoted by X, followed a lognormal distribution with log mean "y"
and log variance a • The mean, variance and 99th percentile of
X are then:
mean of X = E(X) = exp ( y + ct2/2)
variance of X = V(X) = exp (2 y + a2) [exp(o 2) - 1]
99th percentile = X. 99 = exp ( vj + 2.33 0 )
where exp is e, the base of the natural logarithm. The term
lognormal is used because the logarithm of X has a normal
distribution with mean ^ and variance a Using the
basic assumption of lognormality of the actual
treatment effectiveness was determined using a lognormal
distribution that, in a sense, approximates the distribution of
an average of the plants in the data base, i.e., an
"average plant" distribution. The notion of an "average plant"
distribution is not a strict statistical concept but is used
here to determine limits that would represent the performance
capability of an average of the plants in the data base.
This "average plant" distribution for a particular pollutant was
developed as follows; the log mean was determined by taking the
average of all the observations for the pollutant across plants.
The log variance was determined by the pooled within plant
variance. This is the weighted average of the plant variances.
Thus, the log mean represents the average of all the data for the
pollutant and the log variance represents the average of the
plant log variances or average plant variability for the
pollutant.
The one day effluent values were determined as follows:
Let Xij = the jth observation on a particular pollutant at plant
i where
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
i = 1, I
™ If . « *f J i
I = total number of plants
Ji = number of observations at plant i.
Then Yij = In Xij
where In means the natural logarithm.
Then y = log mean over all plants
I Ji
£ £ yij/n,
i=l j=l
where n = total number of observations
I
z
Jl
i=l
and V(y) = pooled log variance
I
I
i - 1
I {Ji - 1) Si2
I
I (Ji - 1)
i = 1
.9
where Si = log variance at plant l
Jj
= E (yij - Yi ) /(Ji - 1)
J = 1
Yi = log mean at plant i.
Thus, y and V(y) are the log mean and log variance, respectively,
of the lognormal distribution used to determine the treatment
effectiveness. The estimated mean and 99th percentile of this
distribution form the basis for the long term average and daily
maximum effluent limitations, respectively. The estimates are
mean = E(X) = exp(y) yn (0.5 V{y))
99th percentile = X.99 = exp [y + 2.33 /V(y) ]
where f (.) is a Bessel function and exp is e, the base of the
natural logarithms (See Aitchison, J. and J.A.C. Brown, The
Lognormal Distribution, Cambridge University Press, 1963). In
cases where zeros were present in the data, a generalized form of
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
the lognormal, known as the delta distribution was used (See
Aitchison and Brown, op. cit., Chapter 9).
For certain pollutants, this approach was modified slightly to
ensure that well-operated lime and settle plants in all CMDB
categories would achieve the pollutant concentration values
calculated from the CMDB. For instance, after excluding the
electroplating data and other data that did not reflect pollutant
removal or proper treatment, the effluent copper data from the
copper forming plants were statistically significantly greater
than the copper data from the other plants. This indicated that
copper forming plants might have difficulty achieving an effluent
concentration value calculated from copper data from all CMDB
categories. Thus, copper effluent values shown in Table VII-14
(page 242) are based only on the copper effluent data from the
copper forming plants. That is, the log mean for copper is the
mean of the logs of all copper values from the copper forming
plants only and the log variance is the pooled log variance of
the copper forming plant data only. A similar situation occurred
in the case of lead. That is, after excluding the electroplating
data, the effluent lead data from battery manufacturing were
significantly greater than the other categories. This indicated
that battery manufacturing plants might have difficulty achieving
a lead concentration calculated from all the CMDB categories.
The lead values proposed in nonferrous metals manufactur ing phase
I were therefore based on the battery manufacturing lead data
only. Comments on the proposed battery manufacturing
regulation objected to this procedure and asserted that the
lead concentration values were too low. Following proposal,
the Agency obtained additional lead effluent data from a battery
manufacturing facility with well-operated lime and settle
treatment. These data were combined with the proposal lead data
and analyzed to determine the final treatment effectiveness
concentrations. The mean lead concentration is unchanged at
0.12 mg/1 but the final one-day maximum and monthly 10-day
average maximum increased to 0.42 and 0.20 mg/1,
respectively. A complete discussion of the lead data and
analysis is contained in a memorandum in the administrative
record for this rulemaking.
In the case of cadmium, after excluding the electroplating data
and data that did not reflect removal or proper treatment, there
were insufficient data to estimate the log variance for cadmium.
The variance used to determine the values shown in Table VII-14
for cadmium was estimated by pooling the within plant variances
for all the other metals. Thus, the cadmium variability is the
average of the plant variability averaged over all the other
metals. The log mean for cadmium is the mean of the logs of the
cadmium observations only. A complete discussion of the data and
calculations for all the metals is contained in the
administrative record for this rulemaking.
Average Effluent Values
Average effluent values that form the basis for the monthly
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
limitations were developed in a manner consistent with the method
used to develop one-day treatment effectiveness in that the
lognormal distribution used for the one-day effluent values was
also used as the basis for the average values. That is, we
assume a number of consecutive measurements are drawn from the
distribution of daily measurements. The average of ten
measurements taken during a month was used as the basis for the
monthly average limitations. The approach used for the 10
measurement values was employed previously in regulations for
other categories. That is, the distribution of the average of 10
samples from a lognormal was approximated by another
lognormal distribution. Although the approximation is not
precise theoretically, there is empirical evidence based on
effluent data from a number of categories that the lognormal is
an adequate approximation for the distribution of small samples.
In the course of previous work the approximation was verified in
a computer simulation study (see "Development Document for
Existing Sources Pretreatraent Standards for the Electroplating
Point Source Category", EPA 440/1-79/003, U.S. Environmental
Protection Agency, Washington, D.C., August 1979). We also note
that the average values were developed assuming independence of
the observations although no particular sampling scheme was
assumed.
Ten-Sample Average:
The formulas for the 10-sample limitations were derived on the
basis of simple relationships between the mean and variance of
the distributions of the daily pollutant measurements and the
average of 10 measurements. We assume the daily concentration
measurements for a particular pollutant, denoted by X, follow a
lognormal distribution with log mean and log variance denoted by
y and o2, respectively. Let X]q denote the mean of
10 consecutive measurements. The following relationships then
hold assuming the daily measurements are independent:
mean of X10 = E^X10) = E(X)
variance of X^g = V(Xiq) = V(X) 10.
Where E(X) and V(X) are the mean and variance of X, respectively,
defined above. We then assume that X^0 follows a
lognormal distribution with log mean u iq and log standard
deviation cr2ig. The mean and variance of X^g are then
3(Xi0) = exp ( u10 + 0.5 e2io)
V(X10) = exp 12 U10 + tf2io [exp ( o2io)-l]
Now, UiO and c 210 can be derived in terms of u and o2 as
U 10 = y + C2/2 - 0.5 In [1 + exp (c2/N]
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
oZio = In [1 + (exp( a2) -l)/N]
Therefore, Wig and 0^10 can be estimated using the above
relationships and the estimates of y and obtained for the
underlying lognorraal distribution. The 10 sample
limitation value was determined by the estimate of the
approximate 99th percentile of the distribution of the 10 sample
average given by
g ( . 99) = exp ( ^ io + 2,33 010)*
where Pio and aiq are the estimates of V ig and o
respectively.
Thirty Sample Average
Monthly average values based on the average of 30 daily
measurements were also calculated. These are included because
monthly limitations based on 30 samples have been used in the
past and for comparison with the 10 sample values. The average
values based on 30 measurements are determined on the basis of a
statistical result known as the Central Limit Theorem. This
Theorem states that, under general and nonrestrictive
assumptions, the distribution of a sum of a number of random
variables, say n, is approximated by the normal distribution.
The approximation improves as the number of variables, n,
increases. The Theorem is quite general in that no particular
distr i but i onal form is assumed for the distribution of the
individual variables. In most applications (as in approximating
the distribution of 30-day averages) the Theorem is used to
approximate the distribution of the average of n observations of
a random variable. The result makes it possible to compute
approximate probability statements about the average in a wide
range of cases. For instance, it is possible to compute a value
below which a specified percentage (e.g., 99 percent) of the
averages of n observations are likely to fall. Most textbooks
state that 25 or 30 observations are sufficient for the
approximation to be valid. In applying the Theorem to the
distribution of the 30-day average effluent values, we
approximate the distribution of the average of 30 observations
drawn from the distribution of daily measurements and use the
estimated 99th percentile of this distribution.
Thirty Sample Average Calculation
The formulas for the 30 sample average were based on an
application of the Central Limit Theorem. According to the
Theorem, the average of 30 observations drawn from the
distribution of daily measurements, denoted by X30, is
approximately normally distributed. The mean and variance of
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
X30 are:
mean of X30 = E(X30) = E(X)
variance of X30 = V(X30) = V(X)/30.
The 30 sample average value was determined by the estimate of the
approximate 99th percentile of the distribution of the 30 sample
average given by
X30?.99) = E(X> = 2.33 /V(X) -s 30
where
E?X) = exp(y) yn (0.5V(y))
and v}x) = exp(2y) [ yn(2V(y)) - n (n-2)/(n-l) V(y) ]
The formulas for E(X) and V(X) are estimates of E(X) and V(X)r
respectively, given in Aitchison, J. and J.A.C. Brown, The
Lognormal Distribution, Cambridge University Press, 1963, page
45.
Application
In response to the proposed coil coating and porcelain enameling
regulations, the Agency received comments pointing out that
permits usually required less than 30 samples to be taken during
a month while the monthly average used as the basis for permits
and pretreatment requirements usually is based on the average of
30 samples.
In applying the treatment effectiveness values to regulations, we
have considered the comments, examined the sampling frequency
required by many permits and considered the change in values of
averages depending on the number of consecutive sampling days in
the averages. The most common frequency of sampling required in
permits is about ten samples per month or slightly greater than
twice weekly. The 99th percentiles of the distribution of
averages of ten consecutive sampling days are not substantially
different from the 99th percentile of the distribution's 30-day
average. (Compared to the one-day maximum, the ten-day average
is about 80 percent of the difference between one- and 30-day
values). Hence the ten-day average provides a reasonable basis
for a monthly average limitation and is typical of the sampling
frequency required by existing permits.
The monthly average limitation is to be achieved in all permits
and pretreatment standards regardless of the number of samples
required to be analyzed and averaged by the permit or the
pretreatment authority. Treatment effectivenss for the nine
pollutants studied in the combined metals data base are tabulated
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
in Table VII-14 (page 242) and are included in Table VI1-21.
Additional Pollutants
Thirty-three additional pollutant parameters were evaluated
to determine the performance of lime and settle treatment systems
in removing them from industrial wastewater. Performance data
for these parameters are not a part of the CMDB so other
available data have been used to determine the long term average
performance of lime and settle technology for each
pollutant. These data are displayed in Table VII-15 (page
243). Treatment effectiveness values for these additional
pollutants were calculated by multiplying the mean performance
from Table VII-15 by the appropriate variability factor.
{The variabi1ity factor is the ratio of the value of concern
to the mean). The pooled variability factors are; one-day
maximum - 4.100; ten-day average 1.821; and 30-day
average - 1.618. These one-, ten-, and thirty-day values are
tabulated in Table VII-21 (page 248).
In establishing which data were suitable for use in Table VII-15
two factors were heavily weighed: (1) the nature of the
wastewater; and (2) the range of pollutants or pollutant matrix
in the raw wastewater. These data have been selected from
processes that generate dissolved metals in the wastewater and
which are generally free from complexing agents. The pollutant
matrix was evaluated by comparing the concentrations of
pollutants found in the raw wastewaters with the range of
pollutants in the raw wastewaters of the combined metals data
set. The raw wastewater pollutant matrix for the CMDB is shown
in Table VII-16 (page 243). Table VII-17 (page 244), displays
the raw waste pollutant matrix of wastewaters from which long
term average treatment effectiveness data were derived for 18 of
the added pollutant(s). Data for the remaining added pollutants
were developed from CMDB related manufacturing facilities. The
available data on these added pollutants do not allow a
homogeneity analysis as was performed on the combined
metals data base. Because the concentrations of the componets in
the raw wastewaters is similar to or less than that of the CMDB
it is appropriate to logically assume transferability of the
treated pollutant concentrations to the combined metals data
base.
Antimony (Sb) - The achievable performance for antimony is based
on data from a battery and secondary lead plant. Both EPA
sampling data and recent permit data (1978-1982) confirm the
achievability of 0.7 mg/1 in the battery manufacturing wastewater
matrix included in the combined data set. The 0.7 mg/1
concentration is achieved at a nonferrous metals manufacturing
and secondary lead plant with the comparable untreated wastewater
matrix shown in Table VII-17 (page 244).
Arsenic (As) - The achievable performance of 0.51 mg/1 for
arsenic is based on permit data from two nonferrous metals
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
manufacturing plants. The untreated wastewater matrix shown in
Table VI1-17 (page 244) is comparable with the combined data set
matrix.
Beryllium (Be) - The achievable performance of beryllium is
from the nonferrous metals manufacturing industry. The 0.3 mg/1
performance is achieved at a beryllium plant with the comparable
untreated wastewater matrix shown in Table VII-17.
Mercury (Hg) - The achievable concentration of 0.06 mg/1 for
mercury is based on data from four battery plants. The untreated
wastewater matrix at these plants was considered in the combined
metals data set.
Selenium (Se) - The achievable concentration of 0.30 mg/1 for
selenium is based on recent permit data from one of the
nonferrous metals manufacturing plants also used for
arsenic performance. The untreated wastewater matrix for this
plant is shown in Table VII-17.
Silver (S) - The achievable concentration of 0.1 mg/1 for
silver is based on an estimate from the inorganic
chemicals industry. Additional data supporting a
treatability as stringent or more stringent than 0.1 mg/1 is
also available from seven nonferrous metals manufacturing
plants. The untreated wastewater matrix for these plants is
comparable and summarized in Table VII-17.
Thallium (T1) The 0.50 mg/1 treatability for thallium is
transferred from the inorganic chemicals industry. Although no
untreated wastewater data are available to verify comparability
with the combined metals data set plants, no other sources of
data for thallium treatability could be identified.
Aluminum (Al) - The 2.24 mg/1 achievable concentration of
aluminum is based on the mean performance of three aluminum
forming plants and one coil coating plant. These plants are
from categories included in the combined metals data set,
assuring untreated wastewater matrix comparability.
Barium (Ba) - The achievable performance for barium (0.42 mg/1)
is based on data from one nonferrous metals forming plant. The
untreated wastewater matrix shown in Table VII-17 is comparable
with the combined metals data base.
Boron (3) - The achievable performance of 0.36 mg/1 for boron is
based on data from a nonferrous metals plant. The untreated
wastewater matrix shown in Table VII-17 is comparable with the
combined metals data base.
Cesium (Cs) - The achievable performance for cesium (0.124 mg/1)
is based on the performance achievable for sodium using ion
exchange technology. This transfer of performance is technically
justifiable because of the similarity of the chemical and
physical behavior of these monovalent atoms.
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
Cobalt (Co) - The 0.05 mg/1 achievable concentration is
based on nearly complete removal of cobalt at a porcelain
enameling plant with a mean untreated wastewater cobalt
concentration of 4.31 mg/1. In this case, the analytical
detection limit using aspiration techniques for this
pollutant is used as the basis of the treatability. Porcelain
enameling was considered in the combined metals data base,
assuring untreated wastewater matrix comparability.
Columbium .(Nb) ~ Data collected at two refractory metals forming
plants indicate that lime and settle reduces columbium to below
the level of detection (using x-ray fluorescence analytical
methods) when an operating pH of eight is maintained. Another
sampled lime and settle treatment system is operated at a higher
pH, from 10.5 to 11.5. Effluent concentrations of columbium from
this system are significantly higher. Therefore, the data
indicate that if the treatment system is operated at a pH near 8,
columbium should be removed to below the level of detection. The
level of detection (0..12 mg/1) is used as the one-day maximum
concentration for lime and settle treatment effectiveness values
are established since it is impossible to determine precisely
what concentrations are achievable. The untreated wastewater
matrix shown in Table VII-17 (page 244) is comparable with the
combined metals data base.
Fluoride (F) - The 14.5 mg/1 treatability of fluoride generally
applicable to metals processing is based on the mean performance
(47 samples) from two electronics manufacturing phase II plants.
The untreated wastewater matrix for this plant shown in Table
VII-17 is comparable to the combined metals data set.
Gallium (Ga) - The achievable concentration of gallium is
assumed to be the same as the level for chromium (0.084 mg/1) for
the reasons discussed below for indium.
Germanium (Ge) - The achievable concentration of germanium is
assumed to be the same as the level for chromium (0.084 mg/1)
for the reasons discussed for indium (see below).
Gold (Au). The treatment effectiveness value for gold (0.1
mg/1) is based on the performance achieved at a secondary
precious metals manufacturing facility whose treatment scheme
includes lime, settle, filter and ion exchange. This value is
supported by data obtained from an ion exchange equipment
manufacturer (Rohm & Haas) for treatment of electroplating rinse
water .
Hafnium (Hf)_ - The achievable performance for hafnium (7.28 mg/1)
is based on the performance achieved for zirconium at two
nonferrous metals forming plants. The Agency believes that
since the water chemistry for zirconium and hafnium is similar,
hafnium can be removed to the same levels as zirconium.
Indium (In) - The achievable concentration for indium is assumed
to be the same as the level for chromium (0.084 mg/1).
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
Lacking any treated effluent data for indium, a comparison was
made between the theoretical solubilities of indium and the
metals in the Combined Metals Data Base: cadmium, chromium,
copper, lead, nickel and zinc. The theoretical solubility
of indium (2.5 x 10-7,) is more similar to the theoretical
solubility of chromium (1.65 x 10-8 ) than it is to the
theoretical solubilities of cadmium, copper, lead, nickel
or zinc. The theoretical solubilities of these metals range
from 20 x 10-3 to 2.2 x 10-5 mc/1. This comparison is further
supported by the fact that indium and chromium both form
hydroxides in the trivalent state. Cadmium, copper, lead,
nickel and zinc all from divalent hydroxides.
Molybdenum |Mo)_ - The 1.83 mg/1 treatment effectiveness is based
on data from a nonferrous metals manufacturing and forming plant
which uses coprecipitat ion of molybdenum with iron. The
treatment effectiveness concentration of 1.83 mg/1 is achievable
with iron coprecipitat ion and lime and settle treatment. The
untreated wastewater matrix shown in Table VII-17 (page 244) is
comparable with the combined metals data base.
Palladium (Pd) - The treatment effectiveness value for palladium
(0.1 mg/1) is based on the performance achieved at a secondary
precious metals manufacturing facility whose treatment scheme
includes lime, settle, filter and ion exchange. This value is
supported by data obtained from an ion exchange equipment
manufacturer (Rohm & Haas) for treatment of electroplating rinse
water.
Phosphorus (P) - The 4.08 mg/1 achievable concentration of
phosphorus is based on the mean of 44 samples including 1.9
samples from the Combined Metals Data Base and 25 samples from
the electroplating data base. Inclusion of electroplating
data with the combined metals data was considered
appropriate, since the removal mechanism for phosphorus is a
precipitation reaction with calcium rather than hydroxide.
Platinum (Pt) - The treatment effectiveness value for platinum
(0.1 mg/1) is based on the performance achieved at a secondary
precious metals manufacturing facility whose treatment scheme
includes lime, settle, filter and ion exchange. This value is
supported by data obtained from an ion exchange equipment
manufacturer (Rohm & Haas) for treatment of electroplating rinse
water.
Radium 226 |Ra 2 26) - The achievable performance of 6.17
picocuries per liter for racium 226 is based on data from one
facility in the uranium subcategory of the Ore Mining and
Dressing category which practices barium chloride coprecipitation
in conjunction with lime and settle treatment. The untreated
wastewater matrix shown in Table VII-17 is comparable with the
Combined Metals Data Base.
Rhenium £Re) - The achievable performance for rhenium (1.83 mg/1)
is based on the performance achieved for molybdenum at a
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
nonferrous metals manufacturing and forming plant. This transfer
of performance is technically justifiable because of the
similarity of the physical and chemical behavior of these
compounds.
Rubidium (Rb) - The achievable performance for rubidium (0.124
mg/i) is based on the performance achievable for sodium using ion
exchange technology. This transfer of performance is technically
justifiable because of the similarity of the chemical and
physical behavior of these monvalent atoms.
Tantalum (Ta) - As with columbium, data collected at two
refractory metals forming plants indicate that lime and settle
reduces tantalum to below the level of detection (using x-ray
fluorescence analytical methods) when an operating pH of eight is
maintained. Another sampled lime and settle treatment system is
operated at a higher pH, from 10.5 to 11.5. Effluent
concentrations of tantalum from this system are
significantly higher. Therefore, the data indicate that if
the treatment system is operated at a pH near 8, tantalum
should be removed to below the level of detection. The level of
detection (0.45 mg/1) is used as the one-day maximum
concentration for lime and settle treatment effect iveness. No
long-term, 10-day, and 30-day average treatment
effectiveness values are established since it is impossible to
determine precisely what concentrations are achievable. The
untreated wastewater matrix shown in Table VII-17 is comparable
with the combined metals data base.
Tin (Sn) - The achievable performance of 0.14 mg/1 for tin is
based on data from one metal finishing tin plant. The
untreated wastewater matrix shown in Table VII-17 is comparable
with the combined metals data base.
Titanium (Ti) - The 0.19 mg/1 achievable concentration is based
on the mean performance of four nonferrous metals forming plants.
A total of 9 samples were included in the calculation of the mean
performance. The untreated wastewater matrix shown in Table VII-
17 is comparable with the combined metals data base.
Tungsten (W) - The 1.29 mg/1 treatability (using x-ray
fluorescence analytical methods) is based on data collected
from the refractory metals forming plant where an operating pH of
10.5 to 11.5 was used. The data indicate that maintaining
the pH within this range achieves significantly better
removal of tungsten than a pH near 8. Therefore, plants
that treat wastewaters containing both tantalum and tungsten or
other metals that precipitate at a higher pH may need to use a
two-stage lime and settle system to remove all of these metals.
The untreated wastewater matrix shown in Table VII-17
is comparable with the combined metals data base.
Uranium jU) - The achievable performance of 4.0 xc/1 for
uranium is based on data from one facility in the uranium
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
subcategory of the Ore Mining and Dressing category which
practices chemical precipitation and sedimentation treatment.
The untreated wastewater matrix shown in Table VII-17 (page 244)
is comparable with the combined metals data base.
Vanadium (V) - Data collected at two nonferrous metals forming
plants indicate that lime and settle reduces vanadium to below
the detection limit. The level of detection (0.10 mg/1) is used
as the one-day maximum concentration for lime and settle
treatment. No long-term, 10-day or 30-day average treatment
effectiveness values are established since it is impossible to
determine precisely what concentrations are achievable. The
untreated wastewater matrix shown in Table VII-17 is comparable
with the combined metals data base.
Zirconium (Zr) - The zirconium treatment effectiveness of 7.28
mg/1 is based on the mean performance of two nonferrous metals
forming plants with lime and settle treatment. One plant forms
zirconium and the other plant forms refractory metals. The
untreated wastewater matrix shown in Table VII-17 is comparable
with the combined metals data base.
Applicability of CMBD and Additional Pollutant Data Base to
Plants with Elevated Raw Wastewater Concentrations
Several comments on the proposed regulations for nonferrous
metals manufacturing pointed out that plants in the category had
concentrated process wastewater discharges containing
significantly higher concentrations of toxic metals than those
observed in plants in the combined metals data base and plants
used to establish treatment effectiveness concentrations for the
additional pollutants. Plants with elevated cadmium, copper,
lead, and zinc concentrations may apply sulfide precipitation and
filtration as a polishing step following lime and settle to
achieve the concentrations based on the CMDB. Plants with
elevated arsenic and selenium concentrations may apply sulfide
precipitation and filtration as a preliminary treatment to lime
and settle to achieve the CMDB concentrations.
Lime and Settle Performance on Cathode Reprocessing Wastewater -
Primary Aluminum
Treatment performance data gathered during a pilot-scale study
conducted by EPA on primary aluminum wastewater demonstrated that
plants operating cathode reprocessing operations and using the
wastewater as makeup for potiine scrubber liquor cannot achieve
the performance values proposed for aluminum, antimony, nickel,
and fluoride. This is due to the matrix differences resulting
from cathode reprocessing. The cathode reprocessing wastewater,
and subsequently the potline scrubber Iiquor, contain dissolved
solids levels in the five to six percent range. Consequently,
the Agency is promulgating effluent limitations and standards
based on specific treatment effectiveness concentrations for
those primary aluminum plants that operate cathode reprocessing
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
and commingle resulting wastewater with potline scrubber liquor.
To receive these alternate limitations the plant may not dilute
potline scrubber liquor blowdown or cathode reprocessing
wastewater with any process or nonprocess wastewater source. If
the potline scrubber blowdown is diluted with other wastewaters,
the complexity of the matrix decreases and thus the
concentrations of the combined metals data base (as well as the
transferred aluminum, antimony and fluoride concentrations) can
be achieved. The derivation of the limitations and standards for
this wastewater is detailed in the primary aluminum supplement.
Cyanide Precipitation Performance in Cathode Reprocess ing
Wastewaters
Cyanide is present in wastewater resulting from cathode
reprocessing in the primary aluminum smelting industry. Its
presence is due to the use of coke and pitch in the electrolytic
reduction of alumina to produce aluminum metal. Cyanide has been
detected at concentrations ranging from approximately 50 to 800
mg/1 in this wastewater. In general, approximately 90 percent of
the cyanide is present as a complex, hexacyanoferrate.
EPA conducted bench-scale and pilot-scale studies on cathode
reprocessing and cryolite recovery wastewater from a primary
aluminum plant. The study was directed at examining the
effectiveness of removing cyanide from this wastewater by
precipitating with ferrous sulfate and ferric chloride. These
treatment performance studies revealed that the performance
limits for cyanide precipitation are not transferrable from coil
coating to primary aluminum wastewater. The pilot study is
summarized in Section VII of the primary aluminum subcategory
supplement.
Treatment Effectiveness Concent rations for Fluoride iri Pr imary
Aluminum and Primary Columbium-Tantalum Subcategories
The Agency has re-evaluated lime and settle technology
performance for fluoride removal. The proposed treatment
performance for fluoride was transferred from electrical and
electronic component manufacturing (phase I) lime and settle mean
performance. However, examination of the electronics data has
lead the Agency to conclude that the raw concentrations of
fluoride in nonferrous metals manufacturing wastewaters more
closely resemble the higher concentrations found in electrical
and electronics phase II rather than phase I (49 FR 55690).
Therefore, the Agency believes it is appropriate to use the mean
performance and daily maximum variability developed for
electronics phase II to establish treatment effectiveness for
fluoride removal by lime and settle treatment.
The fluoride data from Electrical and Electronic Components -
Phase II were taken from self-sampling data from two plants.
There were 20 observations from one plant and 27 from the other,
totaling 47. A geometrical form of the lognormal distribution,
known as the delta lognormal distribution, was used to model the
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data. The new long-term performance concentration of 14.5 mg/1
was estimated using the mean of the distribution of effluent
concentrations. The daily maximum limitation of 35 mg/1 was
based upon estimates of the 99th percentile of the distribution
of effluent concentrations. The monthly average limitation of 20
mg/1 was based on the 99th percentile of the distribution of
averages of 10 samples drawn from the distribution of effluent
concentrations.
LS&F Performance
Tables VII-18 and VII-19 (pages 245 and 246) show long-term data
from two plants which have well operated precipitation-settling
treatment followed by filtration. The wastewaters from both
plants contain pollutants from metals processing and finishing
operations (multi-category). Both plants reduce hexavalent
chromium before neutralizing and precipitating metals with lime.
A clarifier is used to remove much of the solids load and a
filter is used to "polish" or complete removal of suspended
solids. Plant A uses a pressure filter, while plant B uses a
rapid sand filter.
Raw wastewater data was collected only occasionally at each
facility and the raw wastewater data is presented as an
indication of the nature of the wastewater treated. Data from
plant A was received as a statistical summary and is presented as
received. Raw laboratory data was collected at plant B and
reviewed for spurious points and discrepancies. The method of
treating the data base is discussed below under lime, settle, and
filter treatment effectiveness.
Table VII-20 (page 247) shows long-term data for zinc and cadmium
removal at plant C, a primary zinc smelter, which operates a LS&F
system. This data represents about 4 months (103 data days)
taken immediately before the smelter was closed. It has been
arranged similarly to Plants A and B for comparison and use.
These data are presented to demonstrate the performance of
precipitation-settling-filtration (LS&F) technology under actual
operating conditions and over a long period of time.
It should be noted that the iron content of the raw wastewater of
plants A and B is high while that for Plant C is low. This
results, for plants A and B, in co-precipitation of toxic metals
with iron. Precipitation using high-calcium lime for pH control
yields the results shown above. Plant operating personnel
indicate that this chemical treatment combination (sometimes with
polymer assisted coagulation) generally produces better ar.d more
consistent metals removal than other combinations of sacrificial
metal ions and alkalis.
The LS&F performance data presented here are based on systems
that provide polishing filtration after effective L&S treatment.
We have previously shown that L&S treatment is equally applicable
to wastewaters from the five categories because of the
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homogeneity of its raw and treated wastewaters, and other
factors. Because of the similarity of the wastewaters after L&S
treatment, the Agency believes these wastewaters are equally
amenable to treatment using polishing filters added to the L&S
treatment system. The Agency concludes that these LS&F data
based in part on porcelain enameling are directly applicable to
nonferrous metals manufacturing.
Analysis of Treatment System Effectiveness
Data are presented in Table VI1-14 showing the mean, one-day,
10-day, and 30-day values for nine pollutants examined in the L&S
combined metals data base. The pooled variability factor for
seven metal pollutants (excluding cadmium because of the small
number of data points) was determined and is used to estimate
one-day, 10-day and 30-day values. { The variability factor is
the ratio of the value of concern to the mean. The pooled
variability factors are: one-day maximum - 4.100; ten-day
average - 1.821? and 30-day average - 1.618.) For values not
calculated from the CMDB as previously discussed, the mean value
for pollutants shown in Table VII-15 were multiplied by the
variability factors to compute the one, ten and 30-day values.
These are tabulated in Table VI1-21.
The treatment effectiveness for sulfide precipitation and
filtration has been calculated similarly. Long-term average
values shown in Table VII-6 (page 238) have been multiplied by
the appropriate variability factor to estimate one-day maximum,
and ten-day and 30-day average values. Variability factors
developed in the combined metals data base were used because the
raw wastewaters are identical and the treatment methods are
similar as both use chemical precipitation and solids removal to
control metals.
LS&F technology data are presented in Tables VII-18 and VI1-19
(pages 245 and 246). These data represent two operating plants (A
and B) in which the technology has been installed and operated
for some years. Plant A data was received as a statistical
summary and is presented without change. Plant B data was
received as raw laboratory analysis data. Discussions with
plant personnel indicated that operating experiments and changes
in materials and reagents and occasional operating errors
had occurred during the data collection period. No specific
information was available on those variables. To sort out
high values probably caused by methodological factors from random
statistical variability, or data noise, the plant B data
were analyzed. For each of four pollutants (chromium, nickel,
zinc, and iron), the mean and standard deviation (sigma)
were calculated for the entire data set. A data day was removed
from the complete data set when any individua1 pollutant
concentration for that day exceeded the sum of the mean plus
three sigma for that pollutant. Fifty-one data days (from a
total of about 1300) were eliminated by this method.
Another approach was also used as a check on the above method of
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eliminating certain high values. The minimum values of raw
wastewater concentrations from Plant B for the same four
pollutants were compared to the total set of values for the
corresponding pollutants. Any day on which the treated
wastewater pollutant concentration exceeded the minimum value
selected from raw wastewater concentrations for that pollutant
was discarded. Forty-five days of data were eliminated by that
procedure. Forty-three days of data in common were eliminated by
either procedures. Since common engineering practice (mean plus
3 sigma) and logic (treated wastewater concentrations should be
less than raw wastewater concentrations) seem to coincide, the
data base with the 51 spurious data days eliminated is the basis
for all further analysis. Range, mean plus standard deviation
and mean plus two standard deviations are shown in Tables VII-18
and VI1-19 (pages 245 and 246) for Cr, Cu, Ni r Zn and Fe.
The Plant B data was separated into 1979, 1978, and total data
base (six years) segments. With the statistical analysis from
Plant A for 1978 and 1979 this in effect created five data sets
in which there is some overlap between the individual years and
total data sets from Plant B. By comparing these five parts it
is apparent that they are quite similar and all appear to be from
the same family of numbers. The largest mean found among the
five data sets for each pollutant was selected as the long-term
mean for LS&F technology and is used as the LS&F mean in Table
VII-21.
Plant C data was used as a basis for cadmium removal performance
and as a check on the zinc values derived from Plants A and B.
The cadmium data is displayed in Table VII-20 (page 247) and is
incorporated into Table VII-21 (page 248) for LS&F. The zinc
data was analyzed for compliance with the 1-day and 30-day
values in Table VII-21; no zinc value of the 103 data points
exceeded the 1-day zinc value of 1.02 mg/1. The 103 data points
were separated into blocks of 30 points and averaged. Each of
the 3 full 30-day averages was less than the Table VII-
21 value of 0.31 mg/1. Additionally the Plant C raw wastewater
pollutant concentrations (Table VII-20) are well within the
range of raw wastewater concentrations of the combined metals
data base (Table VI1-16), further supporting the conclusion
that Plant C wastewater data is compatible with similar data from
Plants A and B.
Concentration values for regulatory use are displayed in Table
VII-21. Mean one-day, ten-day and 30-day values for L&S for
nine pollutants were taken from Table VII-14 (page 242; the
remaining L&S values were developed using the mean values in
Table VII-15 and the mean variability factors discussed above.
LS&F mean values for Cd, Cr, Ni, Zn and Fe are derived from
plants A, B, and C as discussed above. One-, ten- and thirty-day
values are derived by applying the variability factor developed
from the pooled data base for the specific pollutant to the mean
for that pollutant. Other LS&F values are calculated using the
long-term average or mean and the appropriate variabi lity
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factors.
Copper levels achieved at Plants A and B may be lower than
generally achievable because of the high iron content and low
copper content of the raw wastewaters. Therefore, the mean
concentration value from plants A and B achieved is not used; the
LS&F mean for copper is derived from the L&S technology.
L&S cyanide mean levels shown in Table VII-8 (page 239) are
converted to one-day, ten-day and 30-day values using mean
variability factors. LS&F mean cyanide is calculated by
applying the ratios of removals L&S and LS&F as discussed
previously for LS&F metals limitations. The treatment
method used here is cyanide precipitation. Because cyanide
precipitation is limited by the same physical processes as
the metal precipitation, it is expected that the
variabilities will be similar. Therefore, the average of the
metal variability factors has been used as a basis for
calculating the cyanide one-day, ten-day and thirty-day
average treatment effectiveness values.
The filter performance for removing TSS as shown in Table VI1-9
(page 240) yields a mean effluent concentration of 2.61 mg/1 and
corresponds to a 10-day average of 4.33, 30-day average of
3.36 mg/1 and a one-day maximum of 8.88. These calculated
values more than amply support the classic thirty-day and one-day
values of 10 mg/1 and 15 mg/1, respectively, which are used for
LS&F.
Although iron concentrations were decreased in some LS&F
operations, some facilities using that treatment introduce iron
compounds to aid settling. Therefore, the one-day, ten-day and
30-day values for iron at LS&F were held at the L&S level so as
to not unduly penalize the operations which use the relatively
less objectionable iron compounds to enhance removals of toxic
metals.
The removal of additional fluoride by adding polishing filtration
is suspect because lime and settle technology removes calcium
fluoride to a concentration near its solubility. The one
available data point appears to question the ability of filters
to achieve high removals of additional fluoride. The fluoride
concentrations demonstrated for L&S are used as the treatment
effectiveness for LS&F.
MINOR TECHNOLOGIES
Several other treatment technologies were considered for possible
application in this subcategory. These technologies are
presented here.
8. Carbon Adsorption
The use of activated carbon to remove dissolved organics from
water and wastewater is a long demonstrated technology. It is
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one of the most efficient organic removal processes available.
This sorption process is reversible, allowing activated carbon to
be regenerated for reuse by the application of heat and steam or
solvent. Activated carbon has also proved to be an effective
adsorbent for many toxic metals, including mercury. Regeneration
of carbon which has adsorbed significant metals, however, may be
difficult.
The term activated carbon applies to any amorphous form of carbon
that has been specially treated to give high adsorption
capacities. Typical raw materials include coal, wood, coconut
shells, petroleum base residues, and char from sewage sludge
pyrolysis. A carefully controlled process of dehydration,
carbonization, and oxidation yields a product which is called
activated carbon. This material has a high capacity for
adsorption due primarily to the large surface area available for
adsorption, 500 to 1500 m2/sq m resulting from a large number of
internal pores. Pore sizes generally range from 10 to 100
angstroms in radius.
Activated carbon removes contaminants from water by the process
of adsorption, or the attraction and accumulation of one
substance on the surface of another. Activated carbon
preferentially adsorbs organic compounds and, because of this
selectivity, is particularly effective in removing organic
compounds from aqueous solution.
Carbon adsorption requires pretreatment to remove excess
suspended solids, oils, and greases. Suspended solids in the
influent should be less than 50 mg/1 to minimize backwash
requirements; a downflow carbon bed can handle much higher levels
(up to 2000 mg/1) but requires frequent backwashing. Backwashing
more than two or three times a day is not desirable; at 50 mg/1
suspended solids, one backwash will suffice. Oil and grease
should be less than about 10 mg/1. A high level of dissolved
inorganic material in the influent may cause problems with
thermal carbon reactivation (i.e., scaling and loss of activity)
unless appropriate preventive steps are taken. Such steps might
include pH control, softening, or the use of an acid wash on the
carbon prior to reactivation.
Activated carbon is available in both powdered and granular form.
An adsorption column packed with granular activated carbon is
shown in Figure VII-17 (page 270), Powdered carbon is less
expensive per unit weight and may have slightly higher adsorption
capacity, but it is more difficult to handle and to regenerate.
Application and Performance. Carbon adsorption is used to remove
mercury from wastewaters. The removal rate is influenced by the
mercury level in the influent to the adsorption unit. In Table
VII-24, removal levels found at three manufacturing facilities
are listed.
In the aggregate these data indicate that very low effluent
levels could be attained from any raw waste by use of multiple
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adsorption stages. This is characteristic of adsorption
processes.
Isotherm tests have indicated that activated carbon is very
effective in adsorbing 65 percent of the organic priority
pollutants and is reasonably effective for another 22 percent.
Specifically, for the organics of particular interest, activated
carbon was very effective in removing 2,4-dimethylphenol,
fluoranthene, isophorone, naphthalene, all phthalates, and
phenanthrene. It was reasonably effective on 1,1,1-
trichloroethane, 1,1-dichloroethane, phenol, and toluene. Table
VII-22 (page 249) summarizes the treatment effectiveness for most
of the organic priority pollutants by activated carbon as
compiled by EPA. Table VII-23 (page 250) summarizes classes of
organic compounds together with examples of organics that are
readily adsorbed on carbon.
In response to comments from companies in the primary aluminum
subcategory on the proposed mass limitations for benzo(aJpyrene,
the Agency conducted bench and pilot-scale tests or potline
scrubber liquor to determine the effectiveness of various
wastewater treatment technologies, including carbon adsorption,
in removing polynuclear aromatic hydrocarbons (PAH) from these
wastewaters. The study is discussed in greater detail in Section
VII of the primary aluminum subcategory supplement and in the
record supporting this rulemaking.
The pilot tests demonstrated that activated carbon will reduce
the polynuclear aromatic hydrocarbons to the nominal
quantification limit of 0.010 mg/1.
Advantages and Limitations. The major benefits of carbon
treatment include applicability to a wide variety of organics and
high removal efficiency. Inorganics such as cyanide, chromium,
and mercury are also removed effectively. Variations in
concentration and flow rate are well tolerated. The system is
compact, and recovery of adsorbed materials is sometimes
practical. However, destruction of adsorbed compounds often
occurs during thermal regeneration. If carbon cannot be
thermally desorbed, it must be disposed of along with any
adsorbed pollutants. The capital and operating costs of thermal
regeneration are relatively high. Cost surveys show that thermal
regeneration is generally economical when carbon use exceeds
about 1,000 lb/day. Carbon cannot remove low molecular weight or
highly soluble organics. It also has a low tolerance for
suspended solids, which must be removed to at least 50 mg/1 in
the influent water.
Operational Factors. Reliability: This system should be very
reliable with upstream protection and proper operation and
maintenance procedures.
Maintainability: This system requires periodic regeneration or
replacement of spent carbon and is dependent upon raw waste load
and process efficiency.
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
Solid Waste Aspects: Solid waste from this process is
contaminated activated carbon that requires disposal. Carbon
undergoes regeneration, which reduces the solid waste
problem by reducing the frequency of carbon replacement.
Demonstration Status. Carbon adsorption systems have been
demonstrated to be practical and economical in reducing COD, BOD,
and related parameters in secondary municipal and industrial
wastewaters; in removing toxic or refractory organics from
isolated industrial wastewaters? in removing and recovering
certain organics from wastewaters; and in removing and some times
recovering selected inorganic chemicals from aqueous wastes.
Carbon adsorption is a viable and economic process for organic
waste streams containing up to 1 to 5 percent of refractory or
toxic organics. Its applicability for removal of inorganics such
as metals has also been demonstrated.
9. Centrifuqation
Centrifugation is the application of centrifugal force to
separate solids and liquids in a liquid-solid mixture or to
effect concentration of the solids. The application of
centrifugal force is effective because of the density
differential normally found between the insoluble solids and the
liquid in which they are contained. As a waste treatment
procedure, centrifugation is applied to dewater ing of sludges.
One type of centrifuge is shown in Figure VII-18 (page 271).
There are three common types of centrifuges; disc, basket, and
conveyer. All three operate by removing solids under the
influence of centrifugal force. The fundamental difference among
the three types is the method by which solids are collected in
and discharged from the bowl.
In the disc centrifuge, the sludge feed is distributed between
narrow channels that are present as spaces between stacked
conical discs. Suspended particles are collected and discharged
continuously through small orifices in the bowl wall. The
clarified effluent is discharged through an overflow weir.
A second type of centrifuge which is useful in dewatering sludges
is the basket centrifuge. In this type of centrifuge, sludge
feed is introduced at the bottom of the basket, and solids
collect at the bowl wall while clarified effluent overflows the
lip ring at the top. Since the basket centrifuge does not have
provision for continuous discharge of collected cake, operation
requires interruption of the feed for cake discharge for a minute
or two in a 10 to 30 minute overall cycle.
The third type of centrifuge commonly used in sludge dewatering
is the conveyer type. Sludge is fed through a stat ionary feed
pipe into a rotating bowl in which the solids are settled out
against the bowl wall by centrifugal force. From the bowl wall,
the solids are moved by a screw to the end of the machine, at
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
which point they are discharged. The liquid effluent is
discharged through ports after passing the length of the bowl
under centrifugal force.
Application And Performance. Virtually all industrial waste
treatment systems producing sludge can use centrifugation to
dewater it. Centrifugation is currently being used by a wide
range of industrial concerns.
The performance of sludge dewatering by centrifugation depends on
the feed rate, the rotational velocity of the drum, and the
sludge composition and concentration. Assuming proper design and
operation, the solids content of the sludge can be increased to
20 to 35 percent.
Advantages And Limitations. Sludge dewatering centrifuges have
minimal space requirements and show a high degree of effluent
clarification. The operation is simple, clean, and relatively
inexpensive. The area required for a centrifuge system
installation is less than that required for a filter system or
sludge drying bed of equal capacity, and the initial cost is
lower.
Centrifuges have a high power cost that partially offsets the low
initial cost. Special consideration must also be given to
providing sturdy foundations and soundproofing because of the
vibration and noise that result from centrifuge operation.
Adequate electrical power must also be provided since large
motors are required. The major difficulty encountered in the
operation of centrifuges has been the disposal of the concentrate
which is relatively high in suspended, non-settling solids.
Operational Factors. Reliability: Centrifugation is highly
reliable with proper control of factors such as sludge feed,
consistency, and temperature. Pretreatment such as grit removal
and coagulant addition may be necessary, depending on the
composition of the sludge and on the type of centrifuge employed.
Maintainability: Maintenance consists of periodic lubrication,
cleaning, and inspection. The frequency and degree of inspection
required varies depending on the type of sludge solids being
dewatered and the maintenance service conditions. If the sludge
is abrasive, it is recommended chat the first inspection of the
rotating assembly be made after approximately 1,000 hours of
operation. If the sludge is not abrasive or corrosive, then the
initial inspection might be delayed. Centrifuges not equipped
with a continuous sludge discharge system require periodic
shutdowns for manual sludge cake removal.
Solid Waste Aspects: Sludge dewatered in the centrifugation
process may be disposed of by landfill. The clarified effluent
(centrate), if high in dissolved or suspended solids, may require
further treatment prior to discharge.
Demonstration Status. Centrifugation is currently used in a
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great many commercial applications to dewater sludge. Work is
underway to improve the efficiency, increase the capacity, and
lower the costs associated with centrifugation.
10. Coalescing
The basic principle of coalescence involves the preferential
wetting of a coalescing medium by oil droplets which accumulate
on the medium and then rise to the surface of the solution as
they combine to form larger particles. The most important
requirements for coalescing media are wettability for oil and
large surface area. Monofilament line is sometimes used as a
coalescing medium.
Coalescing stages may be integrated with a wide variety of
gravity oil separation devices, and some systems may incorporate
several coalescing stages. In general, a preliminary oil
skimming step is desirable to avoid overloading the coalescer.
One commercially marketed system for oily waste treatment
combines coalescing with inclined plate separation and
filtration. In this system, the oily wastes flow into an
inclined plate settler. This unit consists of a stack of
inclined baffle plates in a cylindrical container with an oil
collection chamber at the top. The oil droplets rise and impinge
upon the undersides of the plates. They then migrate upward to a
guide rib which directs the oil to the oil collection chamber,
from which oil is discharged for reuse or disposal.
The oily water continues on through another cylinder containing
replaceable filter cartridges, which remove suspended particles
from the waste. From there the wastewater enters a final
cylinder in which the coalescing material is housed. As the oily
water passes through the many small, irregular, continuous
passages in the coalescing material, the oil droplets coalesce
and rise to an oil collection chamber.
Application and Performance. Coalescing is used to treat oily
wastes which do not separate readily in simple gravity systems.
The three-stage system described above has achieved effluent
concentrations of 10 to 15 mg/1 oil and grease from raw waste
concentrations of 1000. mg/1 or more.
Advantages and Limitations. Coalescing allows removal of oil
droplets too finely dispersed for conventional gravity
separation-skimming technology. It also can significantly reduce
the residence times (and therefore separator volumes) required to
achieve separation of oil from some wastes. Because of its
simplicity, coalescing provides generally high reliability and
low capital and operating costs. Coalescing is not generally
effective in removing soluble or chemically stabilized emulsified
oils. To avoid plugging, coalescers must be protected by
pretreatment from very high concentrations of free oil and grease
and suspended solids. Frequent replacement of prefilters may be
necessary when raw waste oil concentrations are high.
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Operational Factors. Reliability: Coalescing is inherently
highly reliable since there are no moving parts, and the
coalescing substrate (monofilament, etc.) is inert in the
process and therefore not subject to frequent regeneration or
replacement requirements. Large loads or inadequate
pretreatment, however, may result in plugging or bypass of
coalescing stages.
Maintainability: Maintenance requirements are generally limited
to replacement of the coalescing medium on an infrequent basis.
Solid Waste Aspects: No appreciable solid waste is generated by
this process.
Demonstration Status. Coalescing has been fully demonstrated in
industr ies generating oily wastewater, although none are
currently in use at any nonferrous metals manufacturing
facilities.
11 * Cyanide Oxidation by Chlor i ne
Cyanide oxidation using chlorine is widely used in industrial
waste treatment to oxidize cyanide. Chlorine can be utilized in
either the elemental or hypochlorite forms. This classic
procedure can be illustrated by the following two step chemical
reaction:
1. Cl2 + NaCN + 2NaOH > NaCNO + 2NaCl + H20
2. 3C12 + 6NaOH + 2NaCNO > 2NaHC03 + N2 + 6NaCl + 2H20
The reaction presented as Equation 2 for the oxidation of cyanate
is the final step in the oxidation of cyanide. A complete' system
for the alkaline chlorination of cyanide is shown in Figure VII-
19 (page 272).
The alkaline chlorination process oxidizes cyanides to carbon
dioxide and nitrogen. The equipment often consists of an
equalization tank followed by two reaction tanks, although the
reaction can be carried out in a single tank. Each tank has an
electronic recorder-controller to maintain required conditions
with respect to pH and oxidation reduction potential (ORP). In
the first reaction tank, conditions are adjusted to oxidize
cyanides to cyanates. To effect the reaction, chlorine is
metered to the reaction tank as required to maintain the ORP in
the range of 350 to 400 millivolts, and 50 percent aqueous
caustic soda is added to maintain a pH range of 9.5 to 10. In
the second reaction tank, conditions are maintained to oxidize
cyanate to carbon dioxide and nitrogen. The desirable ORP and pH
for this reaction are 600 millivolts and a pH of 8.0. Each of
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the reaction tanks is equipped with a propeller agitator designed
to provide approximately one turnover per minute. Treatment by
the batch process is accomplished by using two tanks, one for
collection of water over a specified time period, and one for the
treatment of an accumulated batch. If dumps of concentrated
wastes are frequent, another tank may be required to equalize the
flow to the treatment tank. When the holding tank is full, the
liquid is transferred to the reaction tank for treatment. After
treatment, the supernatant is discharged and the sludges are
collected for removal and ultimate disposal.
Application and Performance. The oxidation of cyanide waste by
chlorine is a classic process and is found in most industrial
plants using cyanide. This process is capable of achieving
effluent levels that are nondetectable.
Advantages and Limitations. Some advantages of chlorine
oxidation for handling process effluents are operation at ambient
temperature, suitability for automatic control, and low cost.
Disadvantages include the need for careful pH control, possible
chemical interference in the treatment of mixed wastes, and the
potential hazard of storing and handling chlorine gas.
Operational Factors. Reliability: Chlorine oxidation is highly
reliable with proper monitoring and control and proper
pretreatment to control interfering substances.
Maintainability: Maintenance consists of periodic removal of
sludge and recalibration of instruments.
Solid Waste Aspects: There is no solid waste problem associated
with chlorine oxidation.
Demonstration Status. The oxidation of cyanide wastes by
chlorine is a widely used process in plants using cyanide in
cleani ng and metal processing baths. Alkaline chlor ination is
also used for cyanide treatment in a number of inorganic chemical
facilities producing hydrocyanic acid and various metal cyanides.
12. Cyanide Oxidation By Ozone
Ozone is a highly reactive oxidizing agent which is approximately
ten times more soluble than oxygen on a weight basis in water.
Ozone may be produced by several methods, but the silent
electrical discharge method is predominant in the field. The
silent electrical discharge process produces ozone by passing
oxygen or air between electrodes separated by an insulating
material. A complete ozonation system is represented in Figure
VI1-20 (page 273).
Application and Performance. Ozonation has been applied
commercially to oxidize cyanides, phenolic chemicals, and
organometal complexes. Its applicability to photographic
wastewaters has been studied' in the laboratory with good
results. Ozone is used in industrial waste treatment primarily
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to oxidize cyanide to cyanate and to oxidize phenols and
dyes to a variety of colorless nontoxic products.
Oxidation of cyanide to cyanate is illustrated below:
CN- + 03 > CNQ- + 02
Continued exposure to ozone will convert the cyanate formed to
carbon dioxide and ammonia; however, this is not economically
practical.
Ozone oxidation of cyanide to cyanate requires 1.8 to 2.0 pounds
ozone per pound of CN~; complete oxidation requires 4.6 to 5.0
pounds ozone per pound of CN . Zinc, copper, and nickel
cyanides are easily destroyed to a nondetectable level, but
cobalt and iron cyanides are more resistant to ozone treatment.
Advantages and Limitations. Some advantages of ozone oxidation
for handling process effluents are its suitability to automatic
control and on-site generation and the fact that reaction
products are not chlorinated organics and no dissolved solids are
added in the treatment step. Ozone in the presence of activated
carbon, ultraviolet, and other promoters shows promise of
reducing reaction time and improving ozone utilization, but the
process at present is limited by high capital expense, possible
chemical interference in the treatment of mixed wastes, and an
energy requirement of 25 kwh/kg of ozone generated. Cyanide is
not economically oxidized beyond the cyanate form.
Operational Factors. Reliability: Ozone oxidation is highly
reliable with proper monitoring and control, and proper
pretreatment to control interfering substances.
Maintainability: Maintenance consists of periodic removal of
sludge, and periodic renewal of filters and desiccators required
for the input of clean dry air? filter life is a function of
input concentrations of detrimental constituents.
Solid Waste Aspects: Pretreatment to eliminate substances which
will interfere with the process may be necessary. Dewatering of
sludge generated in the ozone oxidation process or in an "in
line" process may be desirable prior to disposal.
13. Cyanide Oxidation By Ozone With [JV Radiation
One of the modi f icat ions of the ozonation process is the
simultaneous application of ultraviolet light and ozone for the
treatment of wastewater, including treatment of halogenated
organics. The combined action of these two forms produces
reactions by photolysis, photosensitizarion, hydroxylation,
oxygenation, and oxidation. The process is unique because
several reactions and reaction species are active simultaneously.
Ozonation is facilitated by ultraviolet absorption because both
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the ozone and the reactant molecules are raised to a higher
energy state so that they react more rapidly. In addition, free
radicals for use in the reaction are readily hydrolyzed by the
water present. The energy and reaction intermediates created by
the introduction of both ultraviolet and ozone greatly reduce the
amount of ozone required compared with a system using ozone
alone. Figure VII-21 (page 274) shows a three-stage UV-ozone
system. A system to treat mixed cyanides requires pretreatment
that involves chemical coagulation, sedimentation, clarification,
equalization, and pH adjustment.
Application and Performance. The ozone-UV radiation process was
developed primarily for cyanide treatment in the electroplating
and color photo-processing areas. It has been successfully
applied to mixed cyanides and organics from organic chemicals
manufacturing processes. The process is particularly useful for
treatment of complexed cyanides such as ferricyanide, copper
cyanide, and nickel cyanide, which are resistant to ozone alone.
Cyanide Oxidation By Hydrogen Peroxide
Hydrogen peroxide oxidation removes both cyanide and metals in
cyanide containing wastewaters. In this process, cyanide bearing
waters are heated to 49 to 54° C (120 to 130°F) and the pH is
adjusted to 10.5 to 11.8. Formalin (37 percent formaldehyde) is
added while the tank is vigorously agitated. After 2 to
5 minutes, a proprietary peroxygen compound (41 percent
hydrogen peroxide with a catalyst and additives) is added.
After an hour of mixing, the reaction is complete. The cyanide
is converted to cyanate, and the metals are precipitated as
oxides or hydroxides. The metals are then removed from solution
by either settling or filtration.
The main equipment required for this process is two holding tanks
equipped with heaters and air spargers or mechanical stirrers.
These tanks may be used in a batch or continuous fashion, with
one tank being used for treatment while the other is being
filled. A settling tank or a filter is needed to concentrate the
precipitate.
Application and Performance. The hydrogen peroxide oxidation
process is applicable to cyanide-bearing wastewaters, especially
those containing metal-cyanide complexes. In terms of waste
reduction performance, this process can reduce total cyanide to
less than 0.1 mg/1 and the zinc or cadmium to less than 1.0 mg/1.
Advantages and Limitations. Chemical costs are similar to those
for alkaline chlorination using chlorine and lower than those for
treatment with hypochlorite. All free cyanide reacts and is
completely oxidized to the less toxic cyanate state. In
addition, the metals precipitate and settle quickly, and they may
be recoverable in many instances. However, the process requires
energy expenditures to heat the wastewater prior to treatment.
Demonstration Status. This treatment process was introduced in
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1971 and is used in several facilities. No nonferrous metals
manufacturing plants are known to use oxidation by hydrogen peroxide.
15. Evaporation
Evaporation is a concentration process. Water is evaporated from
a solution, increasing the concentration of solute in the
remaining solution. If the resulting water vapor is condensed
back to liquid water, the evaporation-condensation process is
called distillation. However, to be consistent with industry
terminology, evaporation is used in this report to describe both
processes. Both atmospheric and vacuum evaporation are commonly
used in industry today. Specific evaporation techniques are
shown in Figure VII-22 (page 275) and discussed below.
Atmospheric evaporation could be accomplished simply by boiling
the liquid. However, to aid evaporation, heated liquid is
sprayed on an evaporation surface, and air is blown over the
surface and subsequently released to the atmosphere. Thus,
evaporation occurs by huraidification of the air stream, similar
to a drying process. Equipment for carrying out atmospheric
evaporation is quite similar for most applications. The major
element is generally a packed column with an accumulator bottom.
Accumulated wastewater is pumped from the base of the column,
through a heat exchanger, and back into the top of the column,
wherfe it is sprayed into the packing. At the same time, air
drawn upward through the packing by a fan is heated as it
contacts the hot liquid. The liquid partially vaporizes and
humidifies the air stream. The fan then blows the hot, humid air
to the outside atmosphere. A scrubber is often unnecessary
because the packed column itself acts as a scrubber.
Another form of atmospheric evaporator also works on the air
humidification principle, but the evaporated water is recovered
for reuse by condensation. These air humidification techniques
operate well below the boiling point of water and can utilize
waste process heat to supply the energy required.
In vacuum evaporation, the evaporation pressure is lowered to
cause the liquid to boil at reduced temperature. All of the
water vapor is condensed, and to maintain the vacuum condition,
noneondensible gases (air in particular) are removed by a vacuum
pump. Vacuum evaporation may be either single or double effect.
In double effect evaporation, two evaporators are used, and the
water vapor from the first evaporator (which may be heated by
steam) is used to supply heat to the second evaporator. As it
supplies heat, the water vapor from the first evaporator
condenses. Approximately equal quantities of wastewater are
evaporated in each unit; thus, the double effect system
evaporates twice the amount or water that a single effect system
does, at nearly the same cost in energy but with added capital
cost and complexity. The double effect technique is
thermodynami cally possible because the second evaporator is
maintained at lower pressure (higher vacuum) and, therefore,
lower evaporation temperature. Vacuum evaporation equipment may
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be classified as submerged tube or climbing film evaporation
units.
Another means of increasing energy efficiency is vapor
recompression evaporation, which enables heat to be transferred
from the condensing water vapor to the evaporating wastewater.
Water vapor generated from incoming wastewaters flows to a vapor
compressor. The compressed steam than travels through the
wastewater via an enclosed tube or coil in which it condenses as
heat is transferred to the sur rounding solut ion. In this way,
the compressed vapor serves as a heating medium. After
condensation, this distillate is drawn off continuously as the
clean water stream. The heat contained in the compressed vapor
is used to heat the wastewater, and energy costs for system
operation are reduced.
In the most commonly used submerged tube evaporator, the heating
and condensing coil are contained in a single vessel to reduce
capital cost. The vacuum in the vessel is maintained by an
eductor-type pump, which creates the required vacuum by the flow
of the condenser cooling water through a venturi . Wastewater
accumulates in the bottom of the vessel, and it is evaporated by
means of submerged steam coils. The resulting water vapor
condenses as it contacts the condensing coils in the top of the
vessel. The condensate then drips off the condensing coils into
a collect ion trough that carries it out of the vessel.
Concentrate is removed f rom the bottom of the vessel.
The major elements of the climbing film evaporator are the
evaporator, separator, condenser, and vacuum pump. Wastewater is
"drawn" into the system by the vacuum so that a constant liquid
level is maintained in the separator. Liquid enters the steam-
jacketed evaporator tubes, and part of it evaporates so that a
mixture of vapor and liquid enters the separator. The design of
the separator is such that the liquid is continuously circulated
from the separator to the evaporator. The vapor entering the
separator flows out through a mesh entrainment separator to the
condenser, where it is condensed as it flows down through the
condenser tubes. The condensate, along with any entrained air,
is pumped out of the bottom of the condenser by a liquid ring
vacuum pump. The liquid seal provided by the condensate keeps
the vacuum in the system from being broken.
Application and Per formance. Both atmospheric and vacuum
evaporation are used in many industrial plants, mainly for the
concentration and recovery of process solutions. Many of these
evaporators also recover water for rinsing. Evaporation has also
been applied to recovery of phosphate metal cleaning solutions.
In theory, evaporation should yield a concentrate and a deior.ized
condensate. Actually, carry-over has resulted in condensate
metal concent rat ions as high as 10 mg/1, although the usual level
is less than 3 mg/1, pure enough for most final rinses. The
condensate may also contain organic brighteners and antifoaming
agents. These can be removed with an activated carbon bed, if
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necessary. Samples from one plant showed 1,900 mg/1 zinc in the
feed, 4,570 mg/1 in the concentrate, and 0.4 mg/1 in the
condensate. Another plant had 416 mg/1 copper in the feed and
21,800 mg/1 in the concentrate. Chromium analysis for that plant
indicated 5,060 mg/1 in the feed and 27,500 mg/1 in the
concentrate. Evaporators are available in a range of capacities,
typically from 15 to 75 gph, and may be used in parallel
arrangements for processing of higher flow rates.
Advantages and Limitations. Advantages of the evaporation
process are that it permits recovery of a wide variety of process
chemicals, and it is often applicable to concentration or removal
of compounds which cannot be accomplished by any other means.
The major disadvantage is that the evaporation process consumes
relatively large amounts of energy for the evaporation of water.
However, the recovery of waste heat from many industrial
processes (e.g., diesel generators, incinerators, boilers and
furnaces) should be considered as a source of this heat for a
totally integrated evaporation system. Also, in some cases solar
heating could be inexpensively and effectively applied to
evaporation units. Capital costs for vapor compression
evaporators are substantially higher than for other types of
evaporation equipment. However, the energy costs associated with
the operation of a vapor compression evaporator are significantly
lower than costs of other evaporator types. For some
applications, pretreatment may be required to remove solids or
bacteria which tend to cause fouling in the condenser or
evaporator. The build-up of scale on the evaporator
surfaces reduces the heat transfer efficiency and may
present a maintenance problem or increase operating cost.
However, it has been demonstrated that fouling of the heat
transfer surfaces can be avoided or minimized for certain
dissolved solids by maintaining a seed slurry which
provides preferential sites for precipitate deposition. In
addition, low temperature differences in the evaporator will
eliminate nucleate boiling and supersaturation effects.
Steam distillable impurities in the process stream are carried
over with the product water and must be handled by pre-or post
treatment.
Operational Factors. Reliability: Proper maintenance will
ensure a high degree of reliability for the system. Without such
attention, rapid fouling or deterioration of vacuum seals may
occur, especially when corrosive liquids are handled.
Maintainability: Operating parameters can be automatically
controlled. Pretreatment may be required, as well as periodic
cleaning of the system. Regular replacement of seals, especially
in a corrosive environment, may be necessary.
Solid Waste Aspects: With only a few exceptions, the process
does not generate appreciable quantities of solid waste.
Demonstration Status. Evaporation is a fully developed,
commercially available wastewater treatment system. It is used
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extensively to recover plating chemicals in the electroplating
industry, and a pilot-scale unit has been used in connection with
phosphating of aluminum. Proven performance in silver recovery
indicates that evaporation could be a useful treatment operation
for the photographic industry, as well as for metal finishing.
Vapor compression evaporation has been practically demonstrated
in a number of industries, including chemical manufacturing, food
processing, pulp and paper, and metal working.
16. Flotation
Flotation is the process of causing particles such as metal
hydroxides or oil to float to the surface of a tank where they
can be concentrated and removed. This is accomplished by
releasing gas bubbles which attach to the solid particles,
increasing their buoyancy and causing them to float. In
principle, this process is the opposite of sedimentation. Figure
VI1-23 (page 276) shows one type of flotation system.
Flotation is used primarily in the treatment of wastewater
streams that carry heavy loads of finely divided suspended solids
or oil. Solids having a specific gravity only slightly greater
than 1.0, which would require abnormally long sedimentation
times, may be removed in much less time by flotation. Dissolved
air flotation is of greatest interest in removing oil from water
and is less effective in removing heavier precipitates.
This process may be performed in several ways: foam, dispersed
air, dissolved air, gravity, and vacuum flotation are the most
commonly used techniques. Chemical additives are often used to
enhance the performance of the flotation process.
The principal difference among types of flotation is the method
of generating the minute gas bubbles (usually air) in a
suspension of water and small particles. Chemicals may be used
to improve the efficiency with any of the basic methods. The
following paragraphs describe the different flotation techniques
and the method of bubble generation for each process.
Froth Flotation - Froth flotation is based on differences in the
physiochemical properties in various particles. Wettability and
surface properties affect the particles' ability to attach
themselves to gas bubbles in an aqueous medium. In froth
flotation, air is blown through the solution containing flotation
reagents. The particles with water repellant surfaces stick to
air bubbles as they rise and are brought to the surface. A
mineralized froth layer, with mineral particles attached to air
bubbles, is formed. Particles of other minerals which are
readily wetted by water do not stick to air bubbles and remain in
suspens ion.
Dispersed Air Flotation - In dispersed air flotation, gas bubbles
are generated by introducing the air by means of mechanical
agitation with impellers or by forcing air through porous media.
Dispersed air flotation is used mainly in the metallurgical
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industry,
Dissolved Air Flotation - In dissolved air flotation, bubbles are
produced by releasing air from a supersaturated solution under
relatively high pressure. There are two types of contact between
the gas bubbles and particles. The first type is predominant in
the flotation of flocculated materials and involves the
entrapment of rising gas bubbles in the flocculated particles as
they increase in size. The bond between the bubble and particle
is one of physical capture only. The second type of contact is
one of adhesion. Adhesion results from the intermoleeular
attraction exerted at the interface between the solid particle
and gaseous bubble.
Vacuum Flotation - This process consists of saturating the
wastewater with air either directly in an aeration tank, or by
permitting air to enter on the suction of a wastewater pump. A
partial vacuum is applied, which causes the dissolved air to come
out of solution as minute bubbles. The bubbles attach to solid
particles and rise to the surface to form a scum blanket, which
is normally removed by a skimming mechanism. Grit and other
heavy solids that settle to the bottom are generally raked to a
central sludge pump for removal. A typical vacuum flotation unit
consists of a covered cylindrical tank in which a partial vacuum
is maintained. The tank is equipped with scum and sludge removal
mechanisms. The floating material is continuously swept to the
tank periphery, automatically discharged into a scum trough, and
removed from the unit by a pump also under partial vacuum.
Auxiliary equipment includes an aeration tank for saturating the
wastewater with air, a tank with a short retention time for
removal of large bubbles, vacuum pumps, and sludge pumps.
Application and Performance. The primary variables for flotation
design are pressure, feed solids concentration, and retention
period. The suspended solids in the effluent decrease, and the
concentration of solids in the float increases with increasing
retention period. When the flotation process is used primarily
for clarification, a retention period of 20 to 30 minutes usually
is adequate for separation and concentration.
Advantages and Limitations. Some advantages of the flotation
process are the high levels of solids separation achieved in many
applications, the relatively low energy requirements, and the
adaptability to meet the treatment requirements of different
waste types. Limitations of flotation are that it often requires
addition of chemicals to enhance process performance and that it
generates large quantities of solid waste.
Operational Factors. Reliability: Flotation systems normally
are very reliable with proper maintenance of the sludge collector
mechanism and the motors and pumps used for aeration.
Maintainability; Routine maintenance is required on the pumps
and motors. The sludge collector mechanism is subject to
possible corrosion or breakage and may require periodic
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replacement,
Solid Waste Aspects; Chemicals are commonly used to aid the
flotation process by creating a surface or a structure that can
easily adsorb or entrap air bubbles. Inorganic chemicals, such
as the aluminum and ferric salts, and activated silica, can bind
the particulate matter together and create a structure that can
entrap air bubbles. Various organic chemicals can change the
nature of either the air-liquid interface or the solid-liquid
interface, or both. These compounds usually collect on the
interface to bring about the desired changes. The added
chemicals plus the particles in solution combine to form a large
volume of sludge which must be further treated or properly
disposed.
Demonstration Status. Flotation is a fully developed process and
is readily available for the treatment of a wide variety of
industrial waste streams. Flotation separation is
demonstrated in one primary aluminum plant, namely, at the a
smelter as a part of a system for oil removal.
17. Gravity Sludge Thickening
In the gravity thickening process, dilute sludge is fed from a
primary settling tank or clarifier to a thickening tank where
rakes stir the sludge gently to densify it and to push it to a
central collection well. The supernatant is returned to the
primary settling tank. The thickened sludge that collects on the
bottom of the tank is pumped to dewatering equipment or hauled
away. Figure VI1-24 (page 277) shows the construction of a
gravity thickener.
Application and Performance. Thickeners are generally used in
facilities where the sludge is to be further dewatered by a
compact mechanical device such as a vacuum filter or centrifuge.
Doubling the solids content in the thickener substantially
reduces capital and operating cost of the subsequent dewatering
device and also reduces cost for hauling. The process is
potentially applicable to almost any industrial plant.
Organic sludges from sedimentation units of one to two percent
solids concentration can usually be gravity thickened to six to
ten percent; chemical sludges can be thickened to four to six
percent.
Advantages and Limitations. The principal advantage of a gravity
sludge thickening process is that it facilitates further sludge
dewatering. Other advantages are high reliability and minimum
maintenance requirements.
Limitations of the sludge thickening process are its sensitivity
to the flow rate through the thickener and the sludge removal
rate. These rates must be low enough not to disturb the
thickened sludge.
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Operational Factors. Reliability: Reliability is high with
proper design and operation. A gravity thickener is designed on
the basis of square feet per pound of solids per day, in which
the required surface area is related to the solids entering and
leaving the unit. Thickener area requirements are also expressed
in terras of mass loading, grams of solids per square meter per
day (lbs/sq ft/day).
Maintainability: Twice a year, a thickener must be shut down for
lubrication of the drive mechanisms. Occasionally, water must be
pumped back through the system in order to clear sludge pipes.
Solid Waste Aspects; Thickened sludge from a gravity thickening
process will usually require further dewatering prior to
disposal, incineration, or drying. The clear effluent may be
recirculated in part, or it may be subjected to further treatment
prior to discharge.
Demonstration Status. Gravity sludge thickeners are used
throughout Industry to reduce water content to a level where the
sludge may be efficiently handled. Further dewatering is usually
practiced to minimize costs of hauling the sludge to approved
landfill areas,
18. Insoluble Starch Xanthate
Insoluble starch xanthate is essentially an ion exchange medium
used to remove dissolved heavy metals from wastewater. The water
may then either be reused (recovery application) or discharged
(end-of-pipe application). In a commercial electroplating
operation, starch xanthate is coated on a filter medium. Rinse
water containing dragged out heavy metals is circulated
through the filters and then reused for rinsing. The
starch-heavy metal complex is disposed of and replaced
periodically. Laboratory tests indicate that recovery of
metals from the complex is feasible, with regeneration of the
starch xanthate. Besides electroplating, starch xanthate is
potentially applicable to any other industrial plants where
dilute metal wastewater streams are generated. Its present use
is limited to one electroplating plant.
19. Ion Exchange
Ion exchange is a process in which ions, held by electrostatic
forces to charged functional groups on the surface of the ion
exchange resin, are exchanged for ions of similar charge from the
solution in which the resin is immersed. This is classified as a
sorption process because the exchange occurs on the surface of
the resin, and the exchanging ion must undergo a phase transfer
from solution phase to solid phase. Thus, ionic contaminants in
a waste stream can be exchanged for the harmless ions of the
resin.
Although the precise technique may vary slightly according to the
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application involved, a generalized process description follows.
The wastewater stream being treated passes through a filter to
remove any solids, then flows through a cation exchanger which
contains the ion exchange resin. Here, metallic impurities such
as copper, iron, and trivalent chromium are retained. The stream
then passes through the anion exchanger and its associated resin.
Hexavalent chromium, for example, is retained in this stage. If
one pass does not reduce the contaminant levels sufficiently, the
stream may then enter another series of exchangers. Many ion
exchange systems are equipped with more than one set of
exchangers for this reason. A strongly basic anion exchange
resin may be used alone to remove precious metals, such as gold,
palladium and platinum.
The other major portion of the ion exchange process concerns the
regeneration of the resin, which now holds those impurities
retained from the waste stream. An ion exchange unit with in-
place regeneration is shown in Figure VII-25 (page 278). Metal
ions such as nickel are removed by an acid, cation exchange
resin, which is regenerated with hydrochloric or sulfuric acid,
replacing the metal ion with one or more hydrogen ions. Anions
such as dichromate are removed by a basic, anion exchange resin,
which is regenerated with sodium hydroxide, replacing the anion
with one or more hydroxyl ions. The three principal methods
employed by industry for regenerating the spent resin are:
A) Replacement Service: A regeneration service replaces the
spent resin with regenerated resin, and regenerates the spent
resin at its own facility. The service then has the problem of
treating and disposing of the spent regenerant.
B) In-Place Regeneration: Some establishments may find it less
expensive to do their own regeneration. The spent resin column
is shut down for perhaps an hour, and the spent resin is
regenerated. This results in one or more waste streams which
must be treated in an appropriate manner. Regeneration is
performed as the resins require it, usually every few months.
C) Cyclic Regeneration: In this process, the regeneration of the
spent resins takes place within the ion exchange unit itself in
alternating cycles with the ion removal process. A regeneration
frequency of twice an hour is typical. This very short cycle
time permits operation with a very small quantity of resin and
with fairly concentrated solutions, resulting in a very compact
system. Again, this process varies according to application, but
the regeneration cycle generally begins with caustic being pumped
through the anion exchanger, carrying out hexavalent chromium,
for example, as sodium dichromate. The sodium dichromate stream
then passes through a cation exchanger, converting the sodium
dichromate to chromic acid. After concentration by evaporation
or other means, the chromic acid can be returned to the process
line. Meanwhile, the cation exchanger is regenerated with
sulfuric acid, resulting in a waste acid stream containing the
metallic impurities removed earlier. Flushing the exchangers
with water completes the cycle. Thus, the wastewater is purified
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arid, in this example, chromic acid is recovered. The ion
exchangers, with newly regenerated resin, then enter the ion
removal cycle again.
Application and Performance. The list of pollutants for which
the ion exchange system has proved effective includes aluminum,
arsenic, cadmium, chromium (hexavalent and trivalent), copper,
cyanide, gold, iron, lead, manganese, nickel, palladium,
platinum, selenium, silver, tin, zinc, and more. Thus, it can
be applied to a wide variety of industrial concerns. Because of
the heavy concentrations of metals in their wastewater, the
metal finishing industries utilize ion exchange in several ways.
As an end-of-pipe treatment, ion exchange is certainly
feasible, but its greatest value is in recovery applications. It
is commonly used as an integrated treatment to recover
rinse water and process chemicals. Some electroplating
facilities use ion exchange to concentrate and pur ify
plating baths. Also, many industrial concerns, including a
number of nonferrous metals manufacturing plants, use ion
exchange to reduce salt concentrations in incoming water sources.
The ion exchange process may be used to remove cyanide in a
ferrocyanide complex from wastewater. The process generates a
concentrated stream of the complex, which may be treated using
cyanide precipitation.
Ion exchange is applicable to cyanide removal when the cyanide is
complexed with iron. Experimental data have shown that a
specific resin (Rohm & Haas IRA-958) is very selective to the
removal of iron cyanide complexes. The process described below
is based on the use of this resin and upon operating data
obtained from the vendor and from an actual operating ion
exchange facility.
Two downflow columns are used. The columns are operated in a
merry-go-round configuration (see the granular activated carbon
adsorption process description in this section for a discussion
on this type of operation). The regeneration step is carried out
in two stages. The first step uses regeneration solution from
the previous second regeneration step. The second step uses
fresh regeneration solution. This is done because a large
majority of the pollutant ions are eluted in the first step. The
solution used in the second step yields a dilute solution of the
pollutant and can be used in the first step of the next
regeneration cycle. Separation of the regeneration solution in
this manner results in a 50 percent savings in regeneration
solution costs and a more concentrated product. The regeneration
solution used is 15 percent brine (NaCl).
Unless the cyanide in the influent is already in complexed form,
the wastewater must be treated to convert the free cyanide to the
ferrocyanide complex.
The spent brine solution produced in the regeneration step may be
disposed of as a hazardous waste or sent to cyanide
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precipitation. In this module the cyanide complex is combined
with more iron at low pH to produce an insoluble complex.
Ion exchange is highly efficient at recovering metal bearing
solutions. Recovery of chromium, nickel, phosphate solution, and
sulfuric acid from anodizing is commercial. A chromic acid
recovery efficiency of 99.5 percent has been demonstrated.
Typical data for purification of rinse water have been reported
and are displayed in Table VII-25 (page 251). Sampling at one
nonferrous metals manufacturing plant characterized influent
and effluent streams for an ion exchange unit on a silver bearing
waste. This system was in start-up at the time of sampling,
however, and was not found to be operating effectively.
Advantages and Limitations. Ion exchange is a versatile
technology applicable to a great many situations. This
flexibility, along with its compact nature and performance, makes
ion exchange a very effective method of wastewater treatment.
However, the resins in these systems can prove to be a limiting
factor. The thermal limits of the anion resins, generally in the
vicinity of 60°C, could prevent its use in certain
situations. Similarly, nitric acid, chromic acid, and hydrogen
peroxide can all damage the resins, as will iron, manganese,
and copper when present with sufficient concentrations of
dissolved oxygen. Removal of a particular trace contaminant
may be uneconomical because of the presence of other ionic
species that are preferentially removed. The regeneration of
the resins presents its own problems. The cost of the
regenerative chemicals can be high. In addition, the waste
streams originating from the regeneration process are extremely
high in pollutant concentrations, although low in volume. These
must be further processed for proper disposal.
Operational Factors. Reliability; With the exception of
occasional clogging or fouling of the resins, ion exchange has
proved to be a highly dependable technology.
Maintainability: Only the normal maintenance of pumps, valves,
piping and other hardware used in the regeneration process is
required.
Solid Waste Aspects: Few, if any, solids accumulate within the
ion exchangers, and those which do appear are removed by the
regeneration process. Proper prior treatment and planning can
eliminate solid build-up problems altogether. The brine
resulting from regeneration of the ion exchange resin must
usually be treated to remove metals before discharge. This
can generate solid waste.
Demonstration Status. All of the applications mentioned in this
document are available for commercial use, and industry sources
estimate the number of units currently in the field at well over
120. The research" and development in ion exchange is focusing on
improving the quality and efficiency of the resins, rather than
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new applications. Work is also being done on a continuous
regeneration process whereby the resins are contained on a
fluidtransfusible belt. The belt passes through a
compartmentalized tank with ion exchange, washing, and
regeneration sections. The resins are therefore continually
used and regenerated. No such system, however, has been reported
beyond the pilot stage.
Ion exchange has been used to treat cyanide containing wastewater
at two plants in the primary aluminum subcategory in the
nonferrous metals manufacturing category.
Ion exchange has also been used to treat wastewaters from three
secondary precious metals facilities in the nonferrous
metals manufacturing category. These wastewaters contain
gold, platinum and palladium, as well as base metals.
20. Membrane Filtration
Membrane filtration is a treatment system for removing
precipitated metals from a wastewater stream. It must therefore
be preceded by those treatment techniques which will properly
prepare the wastewater for solids removal. Typically, a membrane
filtration unit is preceded by pH adjustment or sulfide addition
for precipitation of the metals. These steps are followed by the
addition of a proprietary chemical reagent which causes the
precipitate to be non-gelatinous, easily dewatered, and highly
stable. The resulting mixture of pretreated wastewater and
reagent is continuously recirculated through a filter module and
back into a recirculation tank. The filter module contains
tubular membranes. While the reagent-metal hydroxide precipitate
mixture flows through the inside of the tubes, the water and any
dissolved salts permeate the membrane. When the recirculating
slurry reaches a concentration of 10 to 15 percent solids, it is
pumped out of the system as sludge.
Application and Performance. Membrane filtration appears to be
applicable to any wastewater or process water containing metal
ions which can be precipitated using hydroxide, sulfide or
carbonate precipitation. It could function as the primary
treatment system, but also might find application as a polishing
treatment (after precipitation and settling) to ensure continued
compliance with metals limitations. Membrane filtration systems
are being used in a number of industrial applications,
particularly in the metal finishing area. They have also been
used for toxic metals removal in the metal fabrication industry
and the paper industry.
The permeate is claimed by one manufacturer to contain less than
the effluent concentrations shown in Table VII-26 (page )
regardless of the influent concentrations. These claims have
been largely substantiated by the analysis of water samples at
various plants in various industries.
In the performance predictions for this technology, pollutant
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concentrations are reduced to the levels shown below in Table
VII-26 (page 252) unless lower levels are present in the influent
stream.
Advantages and Limitations. A major advantage of the membrane
filtration system is that installations can use most of the
conventional end-of-pipe systems that may already be in place.
Removal efficiencies are claimed to be excellent, even with
sudden variation of pollutant input rates; however, the
effectiveness of the membrane filtration system can be limited by
clogging of the filters. Because pH changes in the waste stream
greatly intensify clogging problems, the pH must be carefully
monitored and controlled. Clogging can force the shutdown of
the system and may interfere with production. In addition,
the relatively high capital cost of this system may limit its
use.
Operational Factors. Reliability: Membrane filtration has been
shown to be a very reliable system, provided that the pH is
strictly controlled. Improper pH can result in the clogging of
the membrane. Also, surges in the flow rate of the waste stream
must be controlled in order to prevent solids from passing
through the filter and into the effluent.
Maintainability; The membrane filters must be regularly
monitored, and cleaned or replaced as necessary. Depending on
the composition of the waste stream and its flow rate, frequent
cleaning of the filters may be required. Flushing with
hydrochloric acid for 6 to 24 hours will usually suffice. In
addition, the routine maintenance of pumps, valves, and other
plumbing is required.
Solid Waste Aspects; When the recirculating reagent-precipitate
slurry reaches 10 to 15 percent solids, it is pumped out of the
system. It can then be disposed of directly or it can undergo a
dewatering process. Because this sludge contains toxic metals,
it requires proper disposal.
Demonst rat ion Status. There are more than 25 membrane filtration
systems presently in use on metal finishing and similar
wastewaters. Bench-scale and pilot-studies are being run in an
attempt to expand the list of pollutants for which this system is
known to be effective.
21. Peat Adsorption
Peat moss is a complex natural organic material containing lignir.
and cellulose as major constituents. These constituents,
particularly lignin, bear polar functional groups, such as
alcohols, aldehydes, ketones, acids, phenolic hydroxides, and
ethers, that can be involved in chemical bonding. Because of the
polar nature of the material, its adsorption of dissolved solids
such as transition metals and polar organic molecules is quite
high. These properties have led to the use of peat as an agent
for the purification of industrial wastewater.
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Peat adsorption is a "polishing" process which can achieve very
low effluent concentrations for several pollutants. If the
concentrations of pollutants are above 10 mg/1, then peat
adsorption must be preceded by pH adjustment for metals
precipitation and subsequent clarification. Pretreatment is also
required for chromium wastes using ferric chloride and sodium
sulfide. The wastewater is then pumped into a large metal
chamber called a kier which contains a layer of peat through
which the waste stream passes. The water flows to a second kier
for further adsorption. The wastewater is then ready for
discharge. This system may be automated or manually operated.
Application and Performance. Peat adsorption can be used in
nonferrous metals manufacturing for removal of residual dissolved
metals from clarifier effluent. Peat moss may be used to treat
wastewaters containing heavy metals such as mercury, cadmium,
zinc, copper, iron, nickel, chromium, and lead, as well as
organic matter such as oil, detergents, and dyes. Peat
adsorption is currently used commercially at a textile plant, a
newsprint facility, and a metal reclamation operation.
Table VI1-27 (page 252) contains performance figures obtained
from pilot-plant studies. Peat adsorption was preceded by pH
adjustment for precipitation and by clarification.
In addition, pilot plant studies have shown that chelated metal
wastes, as well as the chelating agents themselves, are removed
by contact with peat moss.
Advantages and Limitations. The major advantages of the system
include its ability to yield low pollutant concentrations, its
broad scope in terms of the pollutants eliminated, and its
capacity to accept wide variations of waste water composition.
Limitations include the cost of purchasing, storing, and
disposing of the peat moss-, the necessity for regular replacement
of the peat may lead to high operation and maintenance costs.
Also, the pH adjustment must be altered according to the
composition of the waste stream.
Operational Factors. Reliability: The question of long-term
reliability is not yet fully answered. Although the manufacturer
reports it to be a highly reliable system, operating experience
is needed to verify the claim.
Maintainability: The peat moss used in this process soon
exhausts its capacity to adsorb pollutants. At that time, the
kiers must be opened, the peat removed, and fresh peat placed
inside. Although this procedure is easily and quickly
accomplished, it must be done at regular intervals, or the
system's efficiency drops drastically.
Solid Waste Aspects: After removal from the kier, the spent peat
must be eliminated. If incineration is used, precautions should
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be taken to insure that those pollutants removed from the water
are not released again in the combustion process. Presence of
sulfides in the spent peat, for example, will give rise to sulfur
dioxide in the fumes from burning. The presence of significant
quantities of toxic heavy metals in nonferrous metals
manufacturing wastewater will in general preclude incineration of
peat used in treating these wastes.
Demonstration Status. Only three facilities currently use
commercial adsorption systems in the United States - a textile
manufacturer, a newsprint facility, and a metal reclamation firm.
No data have been reported showing the use of peat adsorption in
nonferrous metals manufacturing plants.
22. Reverse Osmosis
The process of osmosis involves the passage of a liquid through a
semipermeable membrane from a dilute to a more concentrated
solution. Reverse osmosis (RO) is an operation in which pressure
is applied to the more concentrated solution, forcing the per-
meate to diffuse through the membrane and into the more dilute
solution. This filtering action produces a concentrate and a
permeate on opposite sides of the membrane. The concentrate can
then be further treated or returned to the original operation for
continued use, while the permeate water can be recycled for use
as clean water. Figure VII-26 (page 279) depicts a reverse
osmosis system.
As illustrated in Figure VII-27, (page 280), there are three
basic configurations used in commercially available RO modules;
tubular, spiral-wound, and hollow fiber. All of these operate on
the principle described above, the major difference being their
mechanical and structural design characteristics.
The tubular membrane module uses a porous tube with a cellulose
acetate membrane lining. A common tubular module consists of a
length of 2.5 cm (1 inch) diameter tube wound on a supporting
spool and encased in a plastic shroud. Feed water is driven into
the tube under pressures varying from 40 to 55 atm (600-800 psi).
The permeate passes through the walls of the tube and is
collected in a manifold while the concentrate is drained off at
the end of the tube. A less widely used tubular RO module uses a
straight tube contained in a housing, under the same operating
conditions.
Spiral-wound membranes consist of a porous backing sandwiched
between two cellulose acetate membrane sheets and bonded along
three edges. The fourth edge of the composite sheet is attached
to a large permeate collector tube. A spacer screen is then
placed on top of the membrane sandwich, and the entire stack is
rolled around the centrally located tubular permeate collector.
The rolled up package is inserted into a pipe able to withstand
the high operating pressures employed in this process, up to 55
atm (800 psi) with the spiral-wound module. When the system is
operating, the pressurized product water permeates the membrane
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and flows through the backing material to the central collector
tube. The concentrate is drained off at the end of the container
pipe and can be reprocessed or sent to further treatment
facilities.
The hollow fiber membrane configuration is made up of a bundle of
polyamide fibers of approximately 0.0075 cm (0.003 in.) OD and
0.0043 cm (0.0017 in.) ID. A commonly used hollow fiber module
contains several hundred thousand of the fibers placed in a long
tube, wrapped around a flow screen, and rolled into a spiral.
The fibers are bent in a U-shape and their ends are supported by
an epoxy bond. The hollow fiber unit is operated under 27 atm
(400 psi), the feed water being dispersed from the center of the
module through a porous distributor tube. Permeate flows through
the membrane to the hollow interiors of the fibers and is
collected at the ends of the fibers.
The hollow fiber and spiral-wound modules have a distinct
advantage over the tubular system in that they are able to load a
very large membrane surface area into a relatively small
volume. However, these two membrane types are much more
susceptible to fouling than the tubular system, which has a
larger flow channel. This characteristic also makes the tubular
membrane much easier to clean and regenerate than either the
spiral-wound or hollow fiber modules. One manufacturer claims
that its helical tubular module can be physically wiped
clean by passing a soft porous polyurethane plug under pressure
through the module.
Application and Performance. In a number of metal processing
plants, the overflow from the first rinse in a countercurrent
setup is directed to a reverse osmosis unit, where it is
separated into two streams. The concent rated stream contains
dragged out chemicals and is returned to the bath to replace the
loss of solution caused by evaporation and dragout. The dilute
stream (the permeate) is routed to the last rinse tank to provide
water for the rinsing operation. The rinse flows from the last
tank to the first tank, and the cycle is complete.
The closed-loop system described above may be supplemented by the
addition of a vacuum evaporator after the RO unit in order to
further reduce the volume of reverse osmosis concentrate. The
evaporated vapor can be condensed and returned to the last rinse
tank or sent on for further treatment.
The largest application has been for the recovery of nickel
solutions. It has been shown that RO can generally be applied
to most acid metal baths with a high degree of
performance, providing that the membrane unit is not
overtaxed. The limitations most critical here are the
allowable pH range and maximum operating pressure for each
particular configuration. Adequate prefiltrat ion is also
essential. Only three membrane types are readily available in
commercial RO units, and their overwhelming use has been for
the recovery of various acid metal baths. For the purpose of
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calculating performance predictions of this technology, a
rejection ratio of 98 percent is assumed for dissolved salts,
with 95 percent permeate recovery.
Advantages and Limitations. The major advantage of reverse
osmosis for handling process effluents is its abi1i ty to
concentrate dilute solutions for recovery of salts and chemicals
with low power requirements. No latent heat of vaporization or
fusion is required for effecting separations; the main energy
requirement is for a high pressure pump. It requires relatively
little floor space for compact, high capaci ty units, and it
exhibits good recovery and rejection rates for a number of
typical process solutions. A limitation of the reverse osmosis
process for treatment of process effluents is its limited
temperature range for satisfactory operation. For cellulose
acetate systems, the preferred limits are 18 to 30°C (65 to
85°F); higher temperatures will increase the rate of membrane
hydrolysis and reduce system life, while lower temperatures will
result in decreased fluxes with no damage to the membrane.
Another limitation is inability to handle certain solutions.
Strong oxidizing agents, strongly acidic or basic solutions,
solvents, and other organic compounds can cause dissolution of
the membrane. Poor rejection of some compounds such as borates
and low molecular weight organics is another problem. Fouling of
membranes by slightly soluble components in solution or colloids
has caused failures, and fouling of membranes by feed waters with
high levels of suspended solids can be a problem. A final
limitation is inability to treat or achieve high concentration
with some solutions. Some concentrated solutions may have
initial osmotic pressures which are so high that they either
exceed available operating pressures or are uneconomical to
treat.
Operational Factors. Reliability: Very good reliability is
achieved so long as the proper precautions are taken to minimize
the chances of fouling or degrading the membrane. Sufficient
testing of the waste stream prior to application of an RO system
will provide the information needed to insure a successful
application.
Maintainability: Membrane life is estimated to range from six
months to three years, depending on the use of the system.
Downtime for flushing or cleaning is on the order cf two hours as
often as once each week; a substantial portion of maintenance
time must be spent on cleaning any prefilters installed ahead of
the reverse osmosis unit.
Solid Waste Aspects: In a closed-loop system utilizing RO there
is a constant recycle of concentrate and a minimal amount of
solid waste. Prefiltration eliminates many solids before they
reach the module and helps keep the build-up to a minimum.
These solids require proper disposal.
Demonstration Status¦ There are presently at least one hundred
reverse osmosis wastewater applications in a variety of
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industries. In addition to these, there are 30 to 40 units being
used to provide pure process water for several industries.
Despite the many types and configurations of membranes, only the
spiral-wound cellulose acetate membrane has had widespread
success in commercial applications.
23. Sludge Bed Drying
As a waste treatment procedure, sludge bed drying is employed to
reduce the water content of a variety of sludges to the point
where they are amenable to mechanical collection and removal to
landfill. These beds usually consist of 15 to 45 cm (6 to 18
in.) of sand over a 30 cm (12 in.) deep gravel drain system made
up of 3 to 6 mm (1/8 to 1/4 in.) graded gravel overlying drain
tiles. Figure VII-28 (page 281) shows the construction of a
drying bed.
Drying beds are usually divided into sectional areas
approximately 7.5 meters (25 ft) wide x 30 to 60 meters (100 to
200 ft) long. The partitions may be earth embankments, but more
often are made of planks and supporting grooved posts.
To apply liquid sludge to the sand bed, a closed conduit or a
pressure pipeline with valved outlets at each sand bed section is
often employed. Another method of application is by means of an
open channel with appropriately placed side openings which are
controlled by slide gates. With either type of delivery system,
a concrete splash slab should be provided to receive the falling
sludge and prevent erosion of the sand surface.
Where it is necessary to dewater sludge continuously throughout
the year regardless of the weather, sludge beds may be covered
with a fiberglass reinforced plastic or other roof. Covered
drying beds permit a greater volume of sludge drying per year in
most climates because of the protection afforded from rain or
snow and because of more efficient control of temperature.
Depending on the climate, a combination of open and enclosed beds
will provide maximum utilization of the sludge bed drying
facilities.
Application and Performance. Sludge drying beds are a means of
dewatering sludge from clarifiers and thickeners. They are
widely used both in municipal and industrial treatment
facilities.
Dewatering of sludge on sand beds occurs by two mechanisms:
filtration of water through the bed and evaporation of water as a
result of radiation and convection. Filtration is generally
complete in one to two days and may result in solids
concentrations as high as 15 to 20 percent. The rate of
filtration depends on the drainability of the sludge.
The rate of air drying of sludge is related to temperature,
relative humidity, and air velocity. Evaporation will proceed at
a constant rate to a critical moisture content, then at a falling
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SECT - VII
rate to an equilibrium moisture content. The average evaporation
rate for a sludge is about 75 percent of that from a free water
surface.
Advantages and Limitations. The main advantage of sludge drying
beds over other types of sludge dewatering is the relatively low
cost of construction, operation, and maintenance.
Its disadvantages are the large area of land required and long
drying times that depend, to a great extent, on climate and
weather.
Operational Factors. Reliability: Reliability is high with
favorable climactic conditions, proper bed design and care to
avoid excessive or unequal sludge application. If climatic
conditions in a given area are not favorable for adequate drying,
a cover may be necessary.
Maintainability: Maintenance consists basically of periodic
removal of the dried sludge. Sand removed from the drying bed
with the sludge must be replaced and the sand layer resurfaced.
The resurfacing of sludge beds is the major expense item in
sludge bed maintenance, but there are other areas which may
require attention. Onderdrains occasionally become clogged and
have to be cleaned. Valves or sludge gates that control the flow
of sludge to the beds must be kept watertight. Provision for
drainage of lines in winter should be provided to prevent damage
from freezing. The partitions between beds should be tight so
that sludge will not flow f rom one compartment to another. The
outer walls or banks around the beds should also be watertight.
Solid Waste Aspects: The full sludge drying bed must either be
abandoned or the collected solids must be removed to a landfill.
These solids contain whatever metals or other materials were
settled in the clarifier. Metals will be present as hydroxides,
oxides, sulfides, or other salts. They have the potential for
leaching and contaminating ground water, whatever the location of
the semidried solids. Thus the abandoned bed or landfill should
include provision for runoff cont rol and leachate monitor ing.
Demonstration Status. Sludge beds have been in common, use in
both municipal and industrial facilities for many years.
However, protection of ground water from contamination is not
always adequate.
24. Ultrafiltration
Ultrafiltration (UF) is a process which uses semipermeable
polymeric membranes to separate emulsified or colloidal materials
suspended in a liquid phase by pressurizing the 1iquid so that it
permeates the membrane. The membrane of an ultrafilter forms a
molecular screen which retains molecular particles based on their
differences in size, shape, and chemical structure. The membrane
permits passage of solvents and lower molecular weight molecules.
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At present, an ultrafilter is capable of removing materials with
molecular weights in the range of 1,000 to 100,000 and particles
of comparable or larger sizes.
In an ultrafiltration process, the feed solution is pumped
through a tubular membrane unit. Water and some low molecular
weight materials pass through the membrane under the applied
pressure of 2 to 8 atm (10 to 100 psiq). Emulsified oil droplets
and suspended particles are retained, concentrated, and removed
continuously. In contrast to ordinary filtration, retained
materials are washed off the membrane filter rather than held by
it. Figure VII-29 (page 282) represents the ultrafiltration
process.
Application and Performance. Ultrafiltration has potential
application to nonferrous metals manufacturing for separation of
oils and residual solids from a variety of waste streams. In
treating nonferrous metals manufacturing wastewater, its greatest
applicability would be as a polishing treatment to remove
residual precipitated metals after chemical precipitation and
clarification. Successful commercial use, however, has been
primarily for separation of emulsified oils from wastewater.
Over one hundred such units now operate in the United States,
treating emulsified oils from a variety of industrial processes.
Capacities of currently operating units range from a few hundred
gallons a week to 50,000 gallons per day. Concentration of oily
emulsions to 60 percent oil or more is possible. Oil
concentrates of 40 percent or more are generally suitable for
incineration, and the permeate can be treated further and in some
cases recycled back to the process. In this way, it is possible
to eliminate contractor removal costs for oil from some oily
waste streams.
The test data in Table VII-28 (page 253) indicate ultrafiltration
performance (note that UF is not intended to remove dissolved
solids).
The removal percentages shown are typical, but they can be
influenced by pH and other conditions.
The permeate or effluent from the ultrafiltration unit is
normally of a quality that can be reused in industrial
applications or discharged directly. The concentrate from the
ultrafiltration unit can be disposed of as any oily or solid
waste.
Advantages and Limitations, Ultrafiltration is sometimes an
attractive alternative to chemical treatment because of lower
capital equipment, installation, and operating costs, very high
oil and suspended solids removal, and little required
pretreatment. It places a positive barrier between pollutants
and effluent which reduces the possibility of extensive pollutant
discharge due to operator error or upset in settling and skimming
systems. Alkaline values in alkaline cleaning solutions can be
recovered and reused in process.
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A limitation of ultrafiltration for treatment of process
effluents is its narrow temperature range (18°C to
30°C) for satisfactory operation. Membrane life decreases
with higher temperatures, but flux increases at elevated
temperatures. Therefore, surface area requirements are a
function of temperature and become a tradeoff between
initial costs and replacement costs for the membrane. In
addition, ultrafiltration cannot handle certain solutions.
Strong oxidizing agents, solvents, and other organic
compounds can dissolve the membrane. Fouling is sometimes a
problem, although the high velocity of the wastewater normally
creates enough turbulence to keep fouling at a minimum. Large
solids particles can sometimes puncture the membrane and must be
removed by gravity settling or filtration prior to the
ultrafiltration unit.
Operational Factors¦ Reliability: The reliability of an
ultrafiltration system is dependent on the proper filtration,
settling or other treatment of incoming waste streams to prevent
damage to the membrane. Careful pilot studies should be done in
each instance to determine necessary pretreatment steps and the
exact membrane type to be used.
Maintainability: A limited amount of regular maintenance is
required for the pumping system. In addition, membranes must
be periodically changed. Maintenance associated with membrane
plug-ging can be reduced by selection of a membrane with optimum
phy-sical characteristics and sufficient velocity of the
waste stream. It is occasionally necessary to pass a
detergent solution through the system to remove an oil and
grease film which accumulates on the membrane. With proper
maintenance, membrane life can be greater than twelve months.
Solid Waste Aspects: Ultrafiltration is used primarily to
recover solids and liquids. It therefore eliminates solid waste
problems when the sol ids (e.g., paint sol ids) can be recycled to
the process. Otherwise, the stream containing solids must be
treated by end-of-pipe equipment. In the most probable
applications within the nonferrous metals manufacturing category,
the ultrafilter would remove hydroxides or sulfides of metals
which have recovery value.
Demonstration Status. The ultrafiltration process is well
developed and commercially available for treatment of wastewater
or recovery of certain high molecular weight liquid and solid
contaminants.
2 5. Vacuum Filtration
In wastewater treatment plants, sludge dewatering by vacuum
filtration generally uses cylindr ical drum filters. These drums
have a filter medium which may be cloth made of natural or
synthetic fibers or a wire-mesh fabric. The drum is suspended
above and dips into a vat of sludge. As the drum rotates slowly,
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part of its circumference is subject to an internal vacuum that
draws sludge to the filter medium. Water is drawn through the
porous filter cake to a discharge port, and the dewatered sludge,
loosened by compressed air, is scraped from the filter mesh.
Because the dewatering of sludge on vacuum filters is relativley
expensive per kilogram of water removed, the liquid sludge is
frequently thickened prior to processing. A vacuum filter is
shown in Figure VII-30 (page ).
Application and Performance. Vacuum filters are frequently used
both in municipal treatment plants and in a wide variety of
industries. They are most commonly used in larger facilities,
which may have a thickener to double the solids content of
clarifier sludge before vacuum filtering.
The function of vacuum filtration is to reduce the water content
of sludge, so that the solids content increases from about 5
percent to about 30 percent.
Advantages and Limitations. Although the initial cost and area
requirement of the vacuum filtration system are higher than those
of a centrifuge, the operating cost is lower, and no special
provisions for sound and vibration protection need be made. The
dewatered sludge from this process is in the form of a moist cake
and can be conveniently handled.
Operational Factors. Reliability: Vacuum filter systems have
proven reliable at many industrial and municipal treatment
facilities. At present, the largest municipal installation is at
the West Southwest wastewater treatment plant of Chicago,
Illinois, where 96 large filters were installed in 1925,
functioned approximately 25 years, and then were replaced with
larger units. Original vacuum filters at Minneapolis-St. Paul,
Minnesota, now have over 28 years of continuous service, and
Chicago has some units with similar or greater service life.
Maintainability: Maintenance consists of the cleaning or
replacement of the filter media, drainage grids, drainage piping,
filter pans, and other parts of the equipment. Experience in a
number of vacuum filter plants indicates that maintenance
consumes approximately 5 to 15 percent of the total time. If
carbonate buildup or other problems are unusually severe,
maintenance time may be as high as 20 percent. For this reason,
it is desirable to maintain one or more spare units.
If intermittent operation is used, the filter equipment should be
drained and washed each time it is taken out of service. An
allowance for this wash time must be made in filtering schedules.
Solid Waste Aspects: Vacuum filters generate a solid cake which
is usually trucked directly to landfill. All o£ the metals
extracted from the plant wastewater are concentrated in the
filter cake as hydroxides, oxides, sulfides, or other salts.
Demonstration Status. Vacuum filtration has been widely used for
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many years. It is a fully proven, conventional technology for
sludge dewatering. Vacuum filtration is used in 20 nonferrous
metals manufacturing plants for sludge dewatering.
26. Permanganate Oxidation
Permanganate oxidation is a chemical reaction by which wastewater
pollutants can be oxidized. When the reaction is carried to
completion, the by-products of the oxidation are not
environmentally harmful. A large number of pollutants can be
practically oxidized by permanganate, including cyanides,
hydrogen sulfide, and phenol. In addition, the chemical oxygen
demand (COD) and many odors in wastewaters and sludges can be
significantly reduced by permanganate oxidation carried to its
end point. Potassium permanganate can be added to wastewater in
either dry or slurry form. The oxidation occurs optimally in the
8 to 9 pH range. As an example of the permanganate oxidation
process, the following chemical equation shows the oxidation of
phenol by potassium permanganate:
3C6H5(OH) + 28KMn04 + 5H20 > 18C02 + 28KOH + 28Mn02.
One of the by-products of this oxidation is manganese dioxide
(Mn02), which occurs as a relatively stable hydrous colloid
usually having a negative charge. These properties, in addition
to its large surface area, enable manganese dioxide to act as a
sorbent for metal cation, thus enhancing their removal from the
wastewater.
Application and Performance. Commercial use of permanganate
oxidation has been primarily for the control of phenol and waste
odors. Several municipal waste treatment facilities report that
initial hydrogen sulfide concentrations (causing serious odor
problems) as high as 100 mg/1 have been reduced to zero through
the application of potassium permanganate, A variety of
industries (including metal finishers and agricultural chemical
manufacturers) have used permanganate oxidation to totally
destroy phenol in their wastewaters.
Advantages and Limitations. Permanganate oxidation has several
advantages as a wastewater treatment technique. Handling and
storage are facilitated by its non-toxic and non-corrosive
nature. Performance has been proved in a number of municipal and
industrial applications. The tendency of the manganese dioxide
by-product to act as a coagulant aid is a distinct advantage over
other types of chemical treatment.
The cost of permanganate oxidation treatment can be limiting
where very large dosages are required to oxidize wastewater
pollutants. In addition, care must be taken in storage to
prevent exposure to intense heat, acids, or reducing agents;
exposure could create a fire hazard or cause explosions. Of
greatest concern is the environmental hazard which the use of
manganese chemicals in treatment could cause. Care must be taken
to remove the manganese from treated water before discharge.
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Operation Factors. Reliability: Maintenance consists of
periodic sludge removal and cleaning of pump feed lines.
Frequency of maintenance is dependent on wastewater
characteristics.
Solid Waste Aspects: Sludge is generated by the process where
the manganese dioxide by-product tends to act as a coagulant aid.
The sludge from permanganate oxidation can be collected and
handled by standard sludge treatment and processing equipment.
No nonferrous metals manufacturing facilities are known to use
permanganate oxidation for wastewater treatment at this time.
Demonstration Status. The oxidiation of wastewater pollutants by
potassium permanganate is a proven treatment process in several
types of industries. It has been shown effective in treating a
wide variety of pollutants in both municipal and industrial
wastes.
27. Activated Alumina Adsorption
Application, Performance, Advantages and Limitations. Activated
alumina adsorbs arsenic and fluorides. Alumina's removal
efficiency depends on the wastewater characteristics. High
concentrations of alkalinity or chloride and high pH reduce
activated alumina's capacity to adsorb. This reduction in
adsorptive capacity is due to the alkalinity causing (e.g.,
hydroxides, carbonates, etc.) and chlorine anions competing with
arsenic and fluoride ions for removal sites on the alumina.
While chemical precipitation can reduce fluoride to less than 14
mg/1 by formation of calcium fluoride, activated alumina can
reduce fluoride levels to below 1.0 mg/1 on a long-term basis.
An initial concentration of 30 mg/1 of fluoride can be reduced by
as much as 85 to 99+ percent. Influent arsenic concentrations of
0.3 to 10 mg/1 can be reduced by 85 to 99+ percent. However,
some complex forms of fluoride are not removed by activated
alumina. Caustic, sulfuric acid, hydrochloric acid, and alum are
used to chemically regenerate activated alumina.
Operational Factors—Reliability and Maintainabi1i ty : Activated
alumina has been used at potable water treatment plants for many
years. Furthermore, the equipment is similar to that found in
ion-exchange water softening plants which are commonly used in
industry to prepare boiler water.
Demonstration Status. The use of activated alumina has not been
reported by any nonferrous metals manufacturing plants nor is it
widely applied in any other industrial categories. High capital
and operation costs generally limit the wide application of this
process in industrial applications.
^® * Ammonia Str ippinq
Ammonia, often used as a process reagent, dissolves in water to
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an extent governed by the partial pressure of the gas in contact
with the liquid. The ammonia may be removed from process
wastewaters by stripping with air or steam.
Air stripping takes place in a packed or lattice tower; air is
blown through the packed bed or lattice, over which the ammonia-
laden stream flows. Usually, the wastewater is heated prior to
delivery to the tower, and air is used at ambient temperature.
The term "ammonia steam stripping" refers to the process of
desorbing aqueous ammonia by contacting the liquid with a
sufficient amount of ammonia-free steam. The steam is introduced
countercurrent to the wastewater to maximize removal of ammonia.
The operation is commonly carried out in packed bed or tray
columns, and the pH is adjusted to 12 or more with lime. Simple
tray designs are used in steam stripping because of the presence
of appreciable suspended solids and the scaling produced by lime.
These allow easy cleaning of the tower, at the expense of
somewhat lower steam water contact efficiency, necessitating the
use of more trays for the same removal efficiency.
Application and Performance. The evaporation of water and the
volatilization of ammonia generally produces a drop in both
temperature and pH, which ultimately limit the removal of ammonia
in a single air stripping tower. However, high removals are
favored by;
1. High pH values, which shift the equilibrium from ammonium
toward free ammonia;
2. High temperature, which decreases the solubility of ammonia
in aqueous solutions; and
3. Intimate and extended contact between the wastewater to be
stripped and the stripping gas.
Of these factors, pH and temperature are generally more
cost-effective to optimize than increasing contact time by an
increase in contact tank volume or recirculation ratio. The
temperature will, to some extent, be controlled by the climatic
conditions; the pH of the wastewater can be adjusted to assure
optimum stripping.
Steam stripping offers better ammonia removal (99 percent or
better) than air stripping for high ammonia wastewaters found in
the primary columbium-tantalum, primary molybdenum and
rhenium, primary tungsten, secondary silver, secondary
molybdenum and vanadium, primary nickel and cobalt, secondary
precious metals, primary and secondary tin, secondary
tungsten and cobalt, secondary uranium and primary zirconium
and hafnium subcategories of this category.
The performance of an ammonia stripping column is influenced by
a number of important variables that are associated with
the wastewater being treated and column design. Brief discussions
224
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
of these variables follow.
Wastewater pH: Ammonia in water exists in two forms, NH3 and
NH4+, the distribution of which is pH dependent. Since only
the molecular form of ammonia (NH3 ) can be stripped, increasing
the fraction of NH3 by increasing the pH enhances the rate of
ammonia desorption.
Column Temperature: The temperature of the stripping column
affects the equilibrium between gaseous and dissolved ammonia, as
well as the equilibrium between the molecular and ionized forms
of ammonia in water. An increase in the temperature reduces the
ammonia solubility and increases the fraction of aqueous ammonia
that is in the molecular form, both exhibiting favorable effects
on the desorption rate.
Steam rate: The rate of ammonia transfer from the liquid to gas
phase is directly proportional to the degree of ammonia
undersaturation in the desorbing gas. Increasing the fate of
steam supply, therefore, increases undersaturation and ammonia
transfer.
Column design: A properly designed stripper column achieves
uniform distribution of the feed liquid across the cross section
of the column, rapid renewal of the liquid gas interface, and
extended liquid-gas contacting area and time.
Chemical analysis data were collected for raw waste
(treatment influent) and treated waste (treatment effluent)
from one plant of the iron and steel manufacturing category. EPA
collected six paired samples in a two-month period. These
data are the data base for determining the effectiveness of
ammonia steam stripping technology and are contained within the
public record supporting this rulemaking. Ammonia treatment at
this coke plant consisted of two steam stripping columns in
series with steam injected countercurrently to the flow of the
wastewater. A lime reactor for pH adjustment separated the two
stripping columns.
An arithmetic mean of the treatment effluent data produced an
ammonia long-term mean value of 32.2 mg/1. The one-day
maximum, 10-day and 30-day average concentrations attainable by
ammonia steam stripping were calculated using the long-term mean
of the 32.2 mg/1 and the variability factors developed for the
combined metals data base. This produced ammonia treatment
effectiveness concentrations of 133.3, 58.6, and 52.1 mg/1
ammonia for the one-day maximum, 10-day and 30-day averages,
respectively.
As discussed below, steam stripping is demonstrated within the
nonferrous metals manufacturing category. EPA believes the
performance data from the iron and steel manufacturing category
provide a valid measure of this technology's performance on
nonferrous category wastewater.
225
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
The Agency has verified the steam stripping performance values
using steam stripping data collected at a zirconium-hafnium
manufacturing plant, which is in the nonferrous category.
Data collected by the plant represent almost two years of
daily operations, and support the long-term mean used to
establish treatment effectiveness.
The Agency also has corroborated the steam stripping performance
values with data submitted by a facility manufacturing columbium
and tantalum. This facility has high influent concentrations of
ammonia and also high influent concentrations of dissolved
solids.
Steam stripping can recover significant quantities of reagent
ammonia from wastewaters containing extremely high initial
ammonia concentrations, which partially offsets the capital and
energy costs of the technology.
Advantages and Limitations. Strippers are widely used in
industry to remove a variety of materials, including hydrogen
sulfide and volatile organics as well as ammonia, from
aqueous streams. The basic techniques have been applied both in
process and in wastewater treatment applications and are well
understood. The use of steam strippers with and without pH
adjustment is standard practice for the removal of hydrogen
sulfide and ammonia in the petroleum refining industry and
has been studied extensively in this context. Air stripping
has treated municipal and industrial wastewater and is
recognized as an effective technique of broad applicability.
Both air and steam stripping have successfully treated ammonia-
laden wastewater, both within the nonferrous metals
manufacturing category or for similar wastes in closely
related industries.
The major drawback of air stripping is the low efficiency in cold
weather and the possibility of freezing within the tower.
Because lime may cause scaling problems and the types of towers
used in air stripping are not easily cleaned, caustic soda is
generally employed to raise the feed pH. Air stripping simply
transfers the ammonia from one medium to another (water to
air), whereas steam stripping allows for recovery and, if
so desired, reuse of ammonia. Four primary tungsten plants use
steam stripping to recover ammonia from process wastewater and
reuse the ammonia in the manufacture of ammonium
paratungstate. The two major limitations of steam
strippers are the critical column design required for proper
operation and the operational problems associated with
fouling of the packing material.
Operational Factors. Reliability and Maintainability: Strippers
are relatively easy to operate. The most complicated part of a
steam stripper is the boiler. Periodic maintenance will prevent
unexpected shutdowns of the boiler.
Packing fouling interferes with the intimate contacting of
226
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
liquid-gas, thus decreasing the column efficiency, and
eventually leads to flooding. The stripper column is
periodically taken out of service and cleaned with acid and
water with air sparging. Column cutoff is predicated on a
maximum allowable pressure drop across the packing of
maximum "acceptable" ammonia content in the stripper bottoms.
Although packing fouling may not be completely avoidable
due to endothermic CaS04 precipitation, column runs could
be prolonged by a preliminary treatment step designed to
remove suspended solids originally present in the feed and
those precipitated after lime addition.
Demonstration Status. Steam stripping has proved to be an
efficient, reliable process for the removal of ammonia from many
types of industrial wastewaters that contain high concentrations
of ammonia. Industries using ammonia steam stripping technology
include the fertilizer industry, iron and steel manufacturing,
petroleum refining, organic chemicals manufacturing, and
nonferrous metals manufacturing. Eight plants in the nonferrous
metals manufacturing category currently practice steam stripping.
IN-PLANT TECHNOLOGY
The intent of in-plant technology for the nonferrous metals
manufacturing point source category is to reduce or eliminate the
waste load requiring end-of-pipe treatment and thereby improve
the efficiency of an existing wastewater treatment system or
reduce the requirements of a new treatment system. In-plant
technology involves water conservation, automatic controls, good
housekeeping practices, process modifications, and waste
treatment.
Process Water Recycle
EPA has promulgated BAT for most subcategories based on 90
percent recycle of wet air pollution control and contact
cooling wastewater. The Agency promulgated a higher rate for
certain waste streams where reported rates of recycle are even
higher. Water is used in wet air pollution control systems to
capture particulate matter or fumes evolved during
manufacturing. Cooling water is used to remove excess heat
from cast metal products.
Recycle is part of the technical basis for many of the
promulgated regulations in the nonferrous metals manufacturing
category. The Agency identified both demonstrated and feasible
recycle opportunities as early as 1973 in proposed effluent
limitations for secondary aluminum.
Recycling of process water is the practice of recirculating water
to be used again for the same purpose. An example of recycling
process water is the return of casting contact cooling wacer to
the casting process after the water passes through a cooling
tower. Two types of recycle are possible—recycle with a bleed
stream (blowdown) and total recycle. Total. recycle may be
227
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
prohibited by the presence of dissolved solids. Dissolved solids
(e.g., sulfates and chlorides) entering a totally recycled waste
stream may precipitate, forming scale if the solubility limits of
the dissolved solids are exceeded. A bleed stream may be
necessary to prevent maintenance problems (pipe plugging or
scaling, etc.) that would be created by the precipitation of
dissolved solids. While the volume of bleed required is a
function of the amount of dissolved solids in the waste stream,
10 percent bleed is a common value for a variety of process waste
streams in the nonferrous metals manufacturing category. The
recycle of process water is currently practiced where it is cost
effective, where it is necessary due to water shortage, or where
the local permitting authority has required it. Recycle, as
compared to the once-through use of process water, is an
effective method of conserving water.
Application and Performance. Required hardware necessary for
recycle is highly site-specific. Basic items include pumps and
piping. Additional materials are necessary if water treatment
occurs before the water is recycled. These items will be
discussed separately with each unit process. Chemicals may be
necessary to control scale build-up, slime, and
corrosion problems, especially with recycled cooling water.
The Agency based its zero discharge of pollutants regulation for
PSES in the secondary copper subcategory on the use of cooling
towers in conjunction with lime precipi tat ion and sedimentation.
The lime precipitation and sedimentation technology was included
to reduce the metals concentrations so that the wastewater could
be completely recycled and reused without corrosion and scaling
problems. Maintenance and energy use are limited to that
required by the pumps, and solid waste generation is dependent on
the type of treatment system in place.
Recycling through cooling towers is the most common practice.
One type of application is shown in Figure VII-31 (page
284). Casting contact cooling water is recycled through a
cooling tower with a blowdown discharge.
A cooling tower is a device which cools water by bringing the
water into contact with air. The water and air flows are
directed in such a way as to provide maximum heat transfer. The
heat is transferred to air primarily by evaporation (about 75
percent), while the remainder is removed by sensible heat
transfer.
Factors influencing the rate of heat transfer and, ultimately,
the temperature range of the tower, include water surface area,
tower packing and configuration, air flow, and packing height. A
large water surface area promotes evaporation, and sensible heat
transfer rates are lower in proportion to the water surface area
provided. Packing (an internal latticework contact area) is
often used to produce small droplets of water which evaporate
more easily, thus increasing the total surface area per unit of
throughput. For a given water flow, increasing the air flow
228
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
increases the amount of heat removed by maintaining higher
thermodynamic potentials. The packing height in the tower should
be high enough so that the air leaving the tower is close to
saturation.
A mechanical-draft cooling tower consists of the following major
components: (1) Inlet-water distributor (2) Packing (3)
Air fans (4) Inlet-air louvers (5) Drift or carry-over
eliminators (6) Cooled water storage basin.
Advantages and Limitations. Recycle offers economic as well as
environmental advantages. Water consumption is reduced and
wastewater handling facilities (pumps, pipes, clarifiers, etc.)
can thus be sized for smaller flows. By concentrating the
pollutants in a much smaller volume (the bleed stream), greater
removal efficiencies can be attained by any applied treatment
technologies. Recycle may require some treatment such as
sedimentation or cooling of water before it is reused.
The ultimate benefit of recycling process water is the reduction
in total wastewater discharge and the associated advantages of
lower flow streams. A potential problem is the build-up
of dissolved solids which could result in sealing. Scaling
can usually be controlled by depressing the pH and increasing
the bleed flow.
Operational Factors. Reliability and Maintainability: Although
the principal construction material in mechanical-draft towers is
wood, other materials are used extensively. For long life and
minimum maintenance, wood is generally pressure-treated with a
preservative. Although the tower structure is usually made of
treated redwood, a reasonable amount of treated fir has been used
in recent years. Sheathing and louvers are generally made of
asbestos cement, and the fan stacks of fiberglass. There is a
trend to use fire-resistant extracted PVC as fill which, at
little or no increase in cost, offers the advantage of permanent
fire-resistant properties.
The major disadvantages of wood are its susceptibility to decay
and fire. Steel construction is occasionally used, but not to
any great extent. Concrete may be used but has relatively high
construction labor costs, although it does offer the advantage of
fire protection.
Various chemical additives are used in cooling water systems to
control scale, slime, and corrosion. The chemical additives
needed depend on the character of the make-up water. All
additives have definite limitations and cannot eliminate the need
for blowdown. Care should be taken in selecting nontoxic or
readily degraded additives, if possible.
Solid Waste Aspects: The only solid waste associated with
cooling towers may be removed scale.
Demonstration Status. Predominantly two types of waste streams
229
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
in the nonferrous metals manufacturing category are currently
being recycled,* casting contact cooling water and air pollution
control scrubber liquor. Two variations of recycle are used:
(1) a wastewater is recycled within a given process, and (2) a
wastewater is combined with others, treated, and the combined
wastewater is recycled to the processes from which it originated.
For example, scrubber liquor may be recycled within the scrubber,
or treated by sedimentation and recycled back to the scrubber.
Total recycle may become more wide-spread in the future if
methods for removal of dissolved solids, such as reverse osmosis
and ion exchange, become more common and less expensive.
The Agency observed extensive recycle of contact cooling water
and scrubber liquor throughout the category. Indeed, some plants
reported 100 percent recycle of process wastewater from these
operations. The Agency believes, however, that most plants may
have to discharge a portion of the recirculating flow to prevent
the excessive build-up of dissolved solids unless dragout
of solids in products or slags is sufficient to prevent
this build-up.
Existing practice supports the selection of a 90 percent recycle
rate. Twenty-nine of 61 aluminum smelting and forming plants
practice greater than 90 percent recycle of the direct chill
casting contact cooling water. Two of the five aluminum smelters
practicing continuous rod casting recycle 90 percent or more of
their contact cooling water. Four of eight primary aluminum
plants using wet air pollution control on anode bake ovens, five
of 11 plants using wet scrubbers on potlines, and three of eight
plants using wet scrubbers for potrooms recycle 90 percent or
more of their scrubber water.
Five of 10 primary electrolytic copper plants currently recycle
90 percent or more of their casting contact cooling water. Two
of three primary zinc plants with leaching scrubbers recycle 90
percent or more. Two of five primary tungsten plants with
scrubbers on reduction furnaces practice 90 percent or greater
recycle. Six of seven secondary silver plants with furnace
scrubbers currently recycle 90 percent or more of the scrubber
water.
Process Water Reuse
Reuse of process water is the practice of recirculating water
used in one production process for subsequent use in a different
production process.
Application and Performance.
process can include using
for another application, or
for an application where water
Reuse of wastewater in a different
a relatively clean wastewater
using a relatively dirty water
quality is of no concern.
Advantages and Limitations. Advantages of reuse are similar to
230
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
the advantages of recycle. Water consumption is reduced and
wastewater treatment facilities can be sized for smaller flows.
Also, in areas where water shortages occur, reuse is an effective
means of conserving water.
Operational Factors. The hardware necessary for reuse of process
wastewaters varies, depending on the specific application. The
basic elements include pumps and piping. Chemical addition is
not usually warranted, unless treatment is required prior to
reuse. Maintenance and energy use are limited to that required
by the pumps. Solid waste generated is dependent upon the type
of treatment used and will be discussed separately with each unit
process.
Demonstration Status. Reuse applications in the nonferrous
metals manfuacturing category are varied. For example, a
secondary uranium facility reuses wastewater from evaporation and
calcination wet air pollution control in raw material leaching
operations. Bauxite refineries commonly reuse water from red mud
inpoundments in digestion operations. A primary aluminum plant
reuses wastewater from casting for air scrubbing. A lead smelter
uses wastewater from air scrubbing for slag granulation, where
all the water is evaporated. A primary copper refinery reuses
precipitated spent electrolyte, known as "black acid," in
leaching operations that are part of an ore beneficiaticn plant.
Process Water Use Reduction
Process water use reduction is the decrease in the amount of
process water used as an influent to a production process per
unit of production. Section V of each of the subcategory
supplements discusses water use in detai1 for each nonfer rous
metals manufacturing operation. A range of water use values
taken from the data collection portfolios is presented for each
operation. The range of values indicates that some plants use
process water more efficiently than others for the same
operation.
Application and Performance. Noncontact cooling water can
replace contact cooling water in some applications. The use of
noncontact heat exchangers eliminates concentration of dissolved
solids by evaporation and minimizes scaling problems. A copper
refinery is currently using this method to achieve zero
discharge. However, industry-wide conversion to noncontact
cooling may not be possible because of a need for extensive
retrofitting. Certain molten metals require contact cooling to
produce desired surface characteristics. Some plants produce a
metal shot by allowing molten metal to flow through a screen into
a tank of water, immediately quenching the metal and producing a
spherical shot product. Shot, generally ca.nnoc be produced
without contact cooling water.
Air Cooling of Cast Metal Products
Appli cation and Performance. Air cooling, for some operations,
231
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
is an alternative to contact cooling water but limited potential
except in low tonnage situations. Tor example, air cooling is
not generally used in the production of high tonnage casting for
several reasons. The casting line can be inordinately long (or
large), a result of an increased number of molds to compensate
for the slower cooling of the metal.
Operational Factors. Maintenance costs are generally higher
because of the longer conveyer, the added heat load on equipment
and lubricants, and the need for added air blowers. Air cooling
without these process appurtenances might greatly reduce finished
metal production from rates now possible with water cooling.
Conversion to dry air pollution control equipment, discussed
further on in this sect ion, is another way to eliminate water
use.
Dry Slag Processing and Granulation
Slag from pyrometallurgical processes is a solid waste that must
be disposed of or reprocessed. Slag can be prepared for disposal
by slag granulation or slag dumping.
Applicat ion and Performance. Slag granulation uses a high-
velocity water jet to produce a finely divided and evenly sized
rock, which can be used as concrete agglomerate or for road
surfacing. Slag dumping is the dumping and subsequent
solidification of slag, composed almost entirely of insolubles,
which can be crushed and sized for such applications as road
surfacing. Slag can be reprocessed if the metal content is high
enough to be economically recovered. Wet or dry milling, and
recovery of metal by melting can be used to process slag with
recoverable amounts of metal. Of course, in all slag reuse
processes, ultimate disposal of the reprocessed slag must be
considered.
Operational Factors-. Although slag dumping eliminates the
wastewater associated with slag granulation, an additional factor
is that large volumes of dust are generated during subsequent
crushing operations and dust control systems may be necessary.
Demonstration Status. Four of the seven primary lead smelters
currently granulate slag prior to disposal. One of the four
plants granulates the slag, mixes the granulated slag in with ore
concentrate feed to sintering to control lead content of the
feed.
Dry Air Pollution Control Devices
Application and Performance. The use of dry air pollution
control devices would allow the elimination of waste streams with
high pollution potentials. The choice of air pollution control
equipment is complicated, and sometimes a wet system is the
necessary choice. The important difference between wet and dry
devices is that wet devices control gaseous pollutants as well as
232
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
particulates.
Wet devices may be chosen over dry devices when any of the
following factors are found: (1) the particle size is
predominantly under 20 microns, (2) flammable particles or gases
are to be treated at minimal combustion risk, (3) both vapors and
particles are to be removed from the carrier medium, (4) the
gases are corrosive and may damage dry air pollution control
devices, and (5) the gases are hot and may damage dry air
pollution control devices.
Equipment for dry control of air emissions includes cyclones, dry
electrostatic precipitators, fabric filters, and afterburners.
These devices remove particulate matter, the first three by
entrapment and the afterburners by combustion.
Afterburner use is limited to air emissions consisting mostly of
combustible particles. Characteristics of the particulate-laden
gas which affect the design and use of a device are gas density,
temperature, viscosity, flammability, corrosiveness, toxicity,
humidi ty, and dew point. Particulate characteristics which
affect the design and use of a device are particle size, shape,
density, resistivity, concentration, and other physiochemical
properties.
In the primary and secondary aluminum subcategories, melting
prior to casting requires wet air pollution control only when
chlorine gas is present in the offgases. Dry air pollution
control methods with inert gas or salt furnace fluxing have been
demonstrated in the category. It is possible to perform all the
metal treatment tasks of removing hydrogen, non-metallic
inclusions, and undesirable trace elements and meet the most
stringent quality requirements without furnace fluxing, using
only in-line metal treatment units. To achieve this, the molten
aluminum is treated in the transfer system between the furnace
and casting units by flowing the metal through a region of very
fine, dense, mixed-gas bubbles generated by a spinning rotor or
nozzle. No process wastewater is generated in this operation, A
schematic diagram depicting the spinning nozzle refining
principle is shown in Figure VI1-32 (page xxx). Another similar
alternate degassing method is to replace the chlorine-rich
degassing agent with a mixture of inert gases and a much lower
proportion of chlorine. The technique provides adequate
degassing while permitting dry scrubbing.
To the extent that nonferrous metals manufactur ing processes are
designed to limit the volume or severity of air emissions, the
volume of scrubber water used for air pollution control also can
be reduced. For example, new or replacement furnaces can be
designed to minimize emission volumes.
Advantages and Limitations. Proper application of a dry control
device can result in particulate removal efficiencies greater
than 99 percent by weight for fabric filters, electrostatic
precipitators, and afterburners, and up to 95 percent for
233
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
cyclones.
Common wet air pollution control devices are wet electrostatic
precipitators, venturi scrubbers, arid packed tower scrubbers.
Collection efficiency for gases will depend on the solubility of
the contaminant in the scrubbing liquid. Depending on the
contaminant removed, collection efficiencies usually approach 99
percent for particles and gases.
Demonstration Status. Plants in the primary and secondary
aluminum, primary zinc, primary lead, secondary copper, secondary
silver, primary precious metals and mercury, and secondary
precious metals subcategories all report the use of dry air
pollution control devices on furnaces and smelting operations.
Good Housekeeping
Good housekeeping and proper equipment maintenance are necessary
factors in reducing wastewater loads to treatment systems.
Control of accidental spills of oils, process chemicals, and
wastewater from washdown and filter cleaning or removal can aid
in abating or maintaining the segregation of wastewater streams.
Curbed areas should be used to contain or control these wastes.
Leaks in pump casings, process piping, etc., should be minimized
to maintain efficient water use. One particular type of leakage
which may cause a water pollution problem is the contamination of
noncontact cooling water by hydraulic oils, especially if this
type of water is discharged without treatment.
Good housekeeping is also important in chemical, solvent, and oil
storage areas to preclude a catastrophic failure situation.
Storage areas should be isolated from high fire-hazard areas and
arranged so that if a fire or explosion occurs, treatment
facilities will not be overwhelmed nor excessive groundwater
pollution caused by large quantities of chemical-laden fire-
protection water.
A conscientiously applied program of water use reduction can be a
very effective method of curtailing unnecessary wastewater flows.
Judicious use of washdown water and avoidance of unattended
running hoses can significantly reduce water use.
234
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
TABLE VII-1
pH CONTROL EFFECT ON METALS REMOVAL
Day 1 Day 2 Day 3
in Out In Out In Out
pH Ranqe 2.4-3.4 8.5-8.7 1.0-3.0 5.0-6.0 2.0-5.0 6.5-8,1
(mg/l)
TSS 39 8 16 19 16 7
Copper 312 0.22 120 5.12 107 0.66
Zinc 250 0.31 32.5 25.0 43.8 0.66
TABLE VII-2
EFFECTIVENESS OF SODIUM HYDROXIDE FOR METALS REMOVAL
Day 1
Day
2
Day
3
In
Out
In
Out
In
Out
pH Range
2.1-2.
9 9.0-9.3
2.0-2.4
8.7-9.1
2.0-2.4
8.6-9.1
(mg/1)
Cr
0.097
0.0
0.057
0.005
0.068
0.005
Cu
0.063
0 .018
0.078
0.014
0.053
0.019
Fe
9.24
0.76
15.5
0.92
9.41
0.95
Pb
1.0
0.11
1. 36
0.13
1.45
0.11
Mn
0.11
0.06
0 .12
0.044
0.11
0.044
Ni
0.077
0.011
0 .036
0 .009
0.069
0.011
Zn
0.054
0 . 0
0.12
0.0
0.19
0.037
TSS 13 11 11
235
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GENERAL DEVELOPMENT DOCUMENT
SECT - VII
TABLE VI1-3
EFFECTIVENESS OF LIME AND
SODIUM HYDROXIDE FOR METALS
REMOVAL
Day
1
Day
2
Day
3
In
Out
In
Out
In
Out
pH range
9.2-9.6
8,3-9.8
9.2
7.6-8.1
9.6
7.8-8.2
(mg/1)
A1
37.3
0.35
38.1
0.35
29.9
0.35
Co
3.92
0.0
4.65
0.0
4.37
0.0
Cu
0.65
0.003
0.63
0.003
0.72
0.003
Fe
137
0.49
110
0.57
208
0 . 58
Mn
175
0.12
205
0.012
245
0.12
Ni
6.86
0.0
5.84
0.0
5.63
0.0
Se
28.6
0.0
30.2
0.0
27.4
0.0
Ti
143
0.0
125
0.0
115
0.0
Zn
18.5
0.027
16.2
0.044
17 .0
0.01
TSS
4390
9
3595
13
2805
13
TABLE VII-4
THEORETICAL SOLUBILITIES OP HYDROXIDES AND SULFIDES
OF SELECTED METALS IN PURE WATER
Metal
Cadmium (Cd++)
Chromium (Cr+ )
Cobalt (Co++)
Copper (Cu++)
Iron (Fe++)
Lead (Pb"1""*")
Manganese (Mn++)
Mercury (Hq++)
Nickel {Ni +)
Solubi1ity of metal ion, mg/1
As Carbonate As Sulfide
linVfini+|
Zinc (Zn+ )
+ )
'
—
2.3
X
10~5
10
X
10~4
6.7
X
10
8.4
X
10
No precipita
2.2
X
10"1
1.0
X
10"'
2.2
X
10"?
5.8
X
10"
8.9
X
10"1
3.4
X
10"
2 .1
7.0
X
10~3
3.8
X
10
1.2
2.1
X
10"
3.9
X
10~4
3.9
X
10~2
9.0
X
10"
6.9
X
10"3
1.9
X
10"1
6.9
X
10"'
13.3
2.1
X
1G"1
7.4
X
10"
. 1«
X
10"4
3.8
X
10"
1.1
7.0
X
10"4
2.3
X
10"
10
&e
18
5
9
3
20
8
12s
236
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
TABLE VI1-5
SAMPLING DATA FROM SULFIDE
PRECIPITATION-SEDIMENTATION SYSTEMS
Lime, FeS, Lime, FeS, NaOH, Ferric
Polyelectrolyte, Polyelectrolyte, Chloride, Na2S
Treatment Settle, Filter Settle, Filter Clarify (1 stage)
+ In Out In Out In Out
pH 5.0-6.8 8-9 7.7 7.38
(mg/i)
Cr 25.6 <0.014 0.022 <0.020 11.45 <-005
Cr 32.3 <0.04 2.4 <0.1 18.35 <.005
Cu 0.029 0.003
Fe 0.52 0.10 108 0.6
Ni 0.68 <0.1
Zn 39.5 <0.07 33.9 0.01 0.060 0.009
These data were obtained from three sources:
Summary Report, Control and Treatment Technology for the
Metal Finishing Industry: Sulfide Precipitation, USEPA, EPA No.
625/8/80-003, 1979.
Industrial Finishing, Vol. 35, No. 11, November, 197 9.
Electroplating sampling data from plant 27045.
237
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
TABLE VII-6
SULFIDE PRECIPITATION-SEDIMENTATION PERFORMANCE
Parameter Treated Effluent (mq/1)
ca o.oi
Cr (T) 0,05
Cu 0.05
Pb 0.01
Hg 0.03
Ni 0.05
Ag 0.05
Zn 0.01
Table VII-6 is based on two reports:
Summary Report, Control and Treatment Technology for the
Metal Finishing Industry: Sulfide Precipitation, USEPA, EPA
No. 625/8/80-003, 1979.
Addendum to Development Document for Effluent Limitations
Guidelines and New Source Performance Standards, Major
Inorganic Products Seqment of lnorqanics Point Source
Category, USEPA., EPA Contract No. EPA 68-01-3281 (Task 7),
June, 1978.
238
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
Matal
TABLE VII-7
FERRITE CO-PRECIPITATION PERFORMANCE
Influent (ntg/1) Effluent (mg/1)
Mercury
7.4
0.001
Cadmium
240
0.008
Copper
10
0.010
Zinc
18
0.016
Chromium
10
<0 .010
Manganese
12
0.007
Nickel
1,000
0.200
Iron
600
0.06
Bismuth
240
0.100
Lead
475
0.010
NOTE: These data are from;
Sources and Treatment of Wastewater in the Nonferrous
Metals Industry, USEPA, EPA No. 600/2-80-074, 1980.
TABLE VI1-8
CONCENTRATION OF TOTAL CYANIDE
(mg/1)
Plant
1057
33056
12052
Method
FeS04
FeS04
ZnS04
In
2.57
2.42
3.28
0.14
0.16
0.46
0.12
Out
0.024
0.015
0.032
0.09
0.09
0.14
0.06
Mean
0.07
239
-------
GENERAL DEVELOPMENT DOCUMENT
SECT - ¥11
Plant ID #
TABLE VI1-9
MULTIMEDIA FILTER PERFORMANCE
TSS Effluent Concentration, mq/1
06097
0.0,
0.0,
0 . 5
13924
1.8,
2.2,
5.6,
4.0,
4.0,
3.0,
3.0,
2.0,
5.6,
3.6,
2.4,
3.4
18538
1.0
30172
1.4,
7.0,
1.0
36048
2.1,
2.6,
1.5
mean
2.61
2.2, 2,8
PLANT ID
01057
09025
11058
TABLE ¥11-10
PERFORMANCE OF SELECTED SETTLING SYSTEMS
SETTLING SUSPENDED SOLIDS CONCENTRATION (mq/1)
DEVICE
Day 1 Day 2 Day 3
In Out 1 Out In Out
Lagoon 54
Clarifier 1100
& Settling
Ponds
Clarifier 451
6
9
17
56
1900
6
12
50
1620
12075
Settling
284
6
242
10
502
14
Pond
19019
Settling
170
1
50
1
Tank
33617
Clarifier
1662
16
1298
4
& Lagoon
40063
Clarifier
4390
9
3595
12
2805
13
44062
Clarifier
182
13
118
14
174
23
46050
Settling
295
10
42
10
153
8
Tank
240
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
TABLE VII-11
SKIMMING PERFORMANCE
Oil &_ Grease (mg/1)
Plant Skimmer Type In Out
06058 API 224,669 17.9
06058 Belt 19.4 8.3
TABLE VII-12
SELECTED PARITION COEFFICIENTS
Log Octanol-Water
Priority Pollutant Partition Coefficient
1 Acenaphthene 4.33
11 1,1,1-Trichloroethane 2.17
13 1,1-Dichloroethane 1.79
15 1,1,2,2-Tetrachloroethane 2.56
18 Bis(2-chloroethyl)ether 1.58
23 Chloroform 1.97
29 1,1-Dichloroethylene 1.48
39 Fluoranthene 5.33
44 Methylene chloride 1.25
64 Pentachlorophenol 5.01
66 Bis(2-ethylhexyl)
phthalate 8.73
67 Butyl benzyl phthalate 5.80
68 Di-n-butyl phthalate 5.20
72 Benzo(a)anthracene 5.61
73 Benzo(a)pyrene 6.04
74 3,4-benzofluoranthene 6.57
75 Benzo(k)fluoranthene 6.84
76 Chrysene 5.61
77 Acenaphthylene 4.07
78 Anthracene 4.45
79 Benzo(ghi)perylene 7.23
80 Fluorene 4.18
81 Phenanthrene 4.46
82 Dibenzo(a,h)anthracene 5.97
83 Indeno(1,2,3,cd)pyrene 7.66
84 Pyrene 5.32
85 Tetrachloroethylene 2.88
86 Toluene 2.69
241
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
TABLE VI1-13
TRACE ORANIC REMOVAL BY SKIMMING
API PLUS BELT SKIMMERS
(From Plant 06058)
Pollutant Influent Effluent
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
TABLE VII-15
L&S PERFORMANCE
ADDITIONAL POLLUTANTS
(mg/I)
Average
Average
Pollutant
Performance
Pollutant
Performance
Sb
0.7
Hf
7.28
As
0.51
In
0.084
Be
0.30
Mo
1.83
Hg
0.06
Pd
0.01
Se
0.30
P
4.08
Ag
0.10
Pt
0.01
Th
0.50
Ra-226
6.17
A1
2.24
Re
1.83
Ba
0.42
Rb
0,124
B
0.36
Ta
<0.12
Cz
0.124
Sn
0.14
Co
0.05
Ti
0.19
Nb
0.12
W
1.29
F
14.5
U
4.0
Ga
0. 084
V
<0.10
Ge
0.084
Xr
7.28
Au
0.01
NOTE: Ra-226 is in picocurries per liter
TABLE VI1-16
COMBINED METALS DATA SET - UNTREATED WASTEWATER
Pollutant Miru Conc^ (mg/1) Max. Cone ¦_ jmg/1)
Cd
<0.1
3.83
Cr
<0.1
116
Cu
<0.1
108
Pb
<0.1
29.2
Ni
<0 .1
27 . 5
Zn
<0.1
337
Fe
<0.1
263
Mn
<0.1
5.98
TSS
4.6
4, 390
243
-------
TABLE VII-17
POLLUTANT CONTENT OF UNTREATED WASTEWATER
For Selection of Average Treatment Effectiveness for Additional Pollutants
(mg/1)
Specific Additional Pollutant
Sb
Pollu-
tant
As
Be
Ag
Ba,Mo£,U Ra-226
Sn
Ti
Zr
Nb&Ta
Sb
8.5
0.58
-
-
-
-
-
-
-
-
-
-
-
As
0.024
4.2
-
-
0.008
_
-
0.068
-
-
-
-
-
Be
-
-
10.24
-
0.02
-
-
-
-
-*
-
-
-
Cd
0.83
<0.1
<0.1
0.043
<0.1
<0.25
-
1.88
<0.25
<0.03
<0.25
9.2
Cr
-
0.18
8.60
0.23
14.0
22.8
0.4
0.035
79.2
0.4
0.07
<0.3
13.
Cu
0.41
33.2
1.24
110.5
2.4
2.2
4.7
0.02
107,0
4.7
0.2
0.5
120.
Pb
76.0
6.5
0.35
11.4
2.70
5.35
9.2
0.065
0.16
9.2
0.2
22.
160.
Hg
-
-
-
-
-
-
-
-
-
-
-
-
-
Ni
-
-
-
100
34.0
0.69
1.4
0.06
47.7
1.4
0.9
<0.25
170.
Se
_
0.58
-
-
-
-
-
-
-
-
-
-
-
Ag
-
-
-
4.7
0.001
-
-
-
-
-
-
2.2
Zn
0.53
3.62
0.12
1512.
0.3
<0.1
0.6
0.17
197.
0.6
1.0
<0.25
0.5
Ba
_
-
_
-
_
-
2.6
-
-
-
-
B
-
_
_
_
17.0
*
1.6
-
-
-
-
-
-
Co
-
-
-
-
-
-
2.2
-
-
-
-
-
-
Ni
_
_
_
_
_
-
-
-
-
-
-
-
98.
F
-
-
-
-
1050.
760.
12.
•
9.25
12.
-
-
-
Fe
-
-
646.
-
62.0
•
-
-
38.3
-
-
-
-
Mo
_
-
_
-
0.5
-
9.2
0.07
_
-
-
-
-
Ra-226 -
_
_
_
_
_
_
1098.
-
-
-
-
-
Ta
-
-
-
-
-
-
-
-
-
-
90.
Sn
_
_
_
1.1
_
_
_
4.39
_
-
-
Ti
_
-
_
_
-
_
_
_
_
24
12
-
170.
w
-
-
-
-
-
-
-
_
-
2.4
-
37.
u
-
_
_
_
_
_
2.30
10.53
-
230
-
-
-
V
_
_
-
_
7.0
_
6.0
-
-
-
_
-
-
Zr
-
-
-
-
-
-
-
-
•
170.
6.7
OS.G
16. 9
_
16.
_
2.8
220.
33.
220.
<1.
860.
72.
TSS
134.
352.
796.
587 .8
690,
5.6
420.
1639.
3500.
420.
<1.
42.
450.
Data
NFM
NFM
NFM
NFM
NFF
E&EC
NFF
OMD
MF
NFF
NFF
NFF
NFF
Source 234
280&
3921
*Y
225 8&
#v
20086
#D,V,
, #x
#wtz
#X&Z
214
30167
X&Y
NOTES:
Values
of Ra-226
in picocuries
per liter.
NFF - Nonferrous
metals
forming
a
w
3
w
>
tr>
a
w
<
M
t"1
O
3
M
SI
i-3
O
o
n
w
2:
in
w
0
1
<
(-) indicates pollutant not analyzed.
Data source consists of industry category and plant ID.
NFM - Nonferrous metals manufacturing
E&EC -Electrical and electronic componets
MF - Metal Finishing
OMD - Ore Mining and Derssing
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
TABLE VI1-18
PRECIPITATION-SETTLING-FILTRATION
Plant A
LSSrF) PERFORMANCE
Parameters
No Pts, Range mq/1
Mean +
std. dev.
Mean + 2
std. dev.
For
1979-
Treated Wastewater
Cr
47
0.015
0.13
0.045
+0.029
0.10
Cu
12
0.01
-
0.03
0.019
+0.006
0.03
Ni
47
0.08
-
0.64
0.22
+ 0.13
0.48
Zn
47
0. 08
_
0.53
0.17
+ 0.09
0.35
Fe
For
1978-
Treated Wastewater
Cr
47
0.01
_
0.07
0.06
+ 0.10
0.26
Cu
28
0.005
-
0.055
0.016
+ 0.010
0.04
Ni
47
0.10
-
0.92
0,20
+ 0.14
0.48
Zn
47
0.08
-
2.35
0.23
+ 0.34
0.91
Fe
21
0.26
—
1.1
0.49
+ 0.18
0.85
Raw
Waste
Cr
5
32.0
—
12. 0
Gu
5
0.08
_
0.45
Ni
5
1.65
-
20.0
Zn
5
33.2
-
32.0
Fe
5
10.0
-
95.0
245
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
TABLE VII-19
PRECIPITATION-SETTLING-FILTRATION (LS&F) PERFORMANCE
Plant B
Parameters
No Pts. Range mq/1
Mean +
std. dev.
Mean + 2
std. dev.
For 1979-Treated Wastewater
Cr
175
0.0
- 0.40
0.068
+0.075
0.22
Cu
176
0.0
- 0.22
0.024
+0.021
0.07
Ni
] 75
0. 01
- 1.49
0.219
+0.234
0.69
Zn
175
0.01
- 0.66
0.054
+0.064
0.18
Fe
174
0.01
- 2.40
0.303
+0.398
1.10
TSS
2
1.00
- 1.00
For 1978-Treated Wastewater
Cr
144
0.0
- 0.70
0.059
+0.088
0 . 24
Cu
143
0.0
- 0.23
0.017
+0.020
0.06
Ni
143
0.0
- 1.03
0.147
+0.142
0.43
Zn
131
0.0
- 0.24
0.037
+0.034
0.11
Fe
144
0.0
- 1.76
0.200
+0.223
0.47
Total 1974-1979-Treated Wastewater
Cr
1288
0.0
- 0.56
0.038
+0.055
0.15
Cu
1290
0.0
- 0.23
0.011
+0.016
0.04
Ni
1287
0.0
- 1.88
0.184
+0.211
0.60
Zn
1273
0.0
- 0.66
0.035
+0.045
0.13
Fe
12B7
0.0
- 3,15
0.402
+0.509
1.42
Raw Waste
Cr
3
2.80
- 9.15
5.90
Cu
3
0.09
- 0.27
0.17
Ni
3
1.61
- 4.89
3.33
Zn
2
2.35
- 3.39
Fe
3
3.13
- 35.9
22.4
TSS
2
177
- 466.
246
-------
GENERAL DEVELOPMENT DOCUMENT
SECT - VII
TABLE VI1-20
PRECIPITATION-SETTLING-FILTRATION (LS&F) PERFORMANCE
Plant C
Mean + Mean + 2
Parameters No Pts. Range (mq/1) std. dev. std. dev.
For Treated Wastewater
Cd 103 0.010 - 0.500 0.049 +0.049 0.147
Zn 103 0.039 - 0.899 0.290 +0.131 0.552
TSS 103 0.100 - 5.00 1.244 +1.043 3.33
pH 103 7.1 - 7.9 9.2*
For Untreated Wastewater
Cd 103 0.039 - 2.319 0.542 +0.381 1.304
Zn 103 0.949 - 29.8 11.009 +6.933 24.956
Fe 3 0.107 - 0.46 0.255
TSS 103 0.80 - 19.6 5.616 +2.896 11.408
pH 103 6.8 - 8.2 7.6*
* pH value is median of 103 values.
247
-------
TABLE VII-21
SUKMAKY OF TREATMENT EFFECTIVENESS fmg/1)
L & S Technology System
L S S F Technology System
Sulfide & Filter Technology System
ro
co
Pollutant
One-day
IC-day
30-day
one-day
10-day
30-day
One-day
10-day
30-day
Parameter
Mean 1
Maximum
Average
Average
Mean Maximum
Average
Average
Mean Maximum
Average
Average
114 Sb
0,70
2,87
1.28
1.14
0.47
1.93
0.86
0.76
115 As
0.51
2.09
0.93
0.83
0. 34
1.39
0.62
0.55
117 Be
C.30
1. 23
0.55
0.49
0.20
0.B2
0.37
0.32
118 Cd
0.079
0.34
0.15
0.13
0.049
0.20
0.08
0.08
0.01 0.04
0.02
0.02
119 Cr
0.084
0.44
0.18
0.12
0.07
0.37
0.15
0.10
0.08 0.21
0.09
0.08
120 CU
0.58
1,90
1.00
0.73
0.39
1.28
C . 61
0.49
0.05 0.21
0.09
0.08
121 CN
0.07
0.29
0.12
0.11
0.047
0,20
0.08
0.08
122 Pb
0.12
0,42
0.20
0.16
0.08
0.28
0.13
0.11
0.01 0.04
0.02
0.02
12 J H<>
0.06
0.25
0.10
0.10
0.036
0.15
0.06
0.06
0.03 0.13
0.06
0.05
124 Nl
0.74
1.92
1.27
1.00
0.22
0. 55
0. 37
0.29
0.05 0.21
0,09
0.08
125 Se
0. 30
1.23
0.55
0.49
0.20
0.82
0.37
0.33
126 Ag
0.10
0.41
0.17
0.16
0.07
0.29
0.12
0.10
0.05 0.21
0.09
0.08
127 T1
0.50
2.05
0.91
0.81
0.34
1.40
0.61
0.55
128 Zn
0.33
1.46
0.61
0.45
0.23
1.02
0.42
0.31
0.01 0.04
0.02
0.02
A1
2.24
6.43
3.20
2.52
1.49
6.11
2.71
2.41
CO
0.05
0,21
0.09
0.08
0.034
0.14
0.07
.06
F
14.50
35.00
19.90
14. 50
35.00
19.90
Fe
0.41
1.20
0.61
0.50
0.28
1.20
0.61
.50
Kn
0.16
0,68
0. 29
0.21
0.14
0.30
0.23
.19
P
4.08
16.70
6.83
6,60
2.72
11.20
4.60
4.40
O&G
20.00
12.00
10.00
10.00
10.00
10.00
TSS
12,00
41,00
19.50
15.50
2.60
15.00
12.00
10.00
Ammonia
32.20
133.30
58.60
52.10
32.20
133.30
58.60
52.10
Barium
0.42
5.55
2.54
NC
0.28
1.15
0. 51
NC
Boron
0.36
1.84
C.B4
NC
0.36
1.84
0.84
NC
Cesium
0.124
0.51
0.23
NC
0.124
C.51
0. 23
NC
Gallium
0.084
0,44
0.18
0.12
0.07
0,37
0.15
0.10
Germanium
0.084
0,44
0.18
A
0.12
0.07
0.37
0.15
0.10
Gold
« #
*.10
U
* *
A *
* «
*.10
* *
* w
Hafnium
7. 28
28,80
13.90
NC
4 .81
19.70
9.01
NC
Indium
0.084
0.44
0,18
0.12
0.07
.37
0.15
0.10
Molybdenum
1.83
6,61
3.42
NC
1.23
5.03
2.23
NC
Palladium
*#
*.10
* A
* *
* *
*.10
* *
« *
Platinum
* *
*.10
* *
* #
• *
*.10
* #
* #
Radium***
6.17
30.00
11.23
10.00
4.13
20.00
7.52
6.67
Rhenium
1.83
6.61
3. 42
NC
1.23
5.03
2.23
NC
Rubidiun
C.124
0.51
0.23
NC
0.124
0.51
0.23
NC
Tantalum
* *
*.45
* *
# #
* *
*.45
f> *
* *
Tin
0.14
0. 38
0.22
*#
0.14
0.38
0.22
* *
07/03/86
Titanium
0.19
0.94
0.41
NC
0.13
0.53
0.23
NC
NC - Not Calculated
* - Limits of detection
Tungsten
1.23
6.96
2.78
NC
0.85
3.48
1.55.
NC
** - None established
Uraniuir.
4.00
6,50
4.73
NC
2 .67
4.29
3.12
NC
*** - Isotope 226
i. values
in
Vanadiura
* *
*.10
* A
* *
* *
*.10
* *
#*
picocuri es
per liter
Zireomu.it
7.28
28.SO
13.90
HC
4 .El
19.70
9.CI
NC
t"1
a
w
<
H
f
o
V
s
w
25
O
O
n
c
s
M
2:
»-a
C/J
M
O
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
TABLE VII-22
TREATABILITY RATING OF PRIORITY POLLUTANTS
UTILIZING CARBON ADSORPTION
Priority Pollutant
1.
acenaphthene
H
48.
dichlorobromomethane
M
2.
acrolein
L
51.
chlorodibromomothane
H
3.
acrylonitrile
L
52.
hexachlorobutadiene
H
4.
benzene
M
53.
hexachlorocyclopentadiene
H
5.
be.nzidene
H
54.
isophorone
H
6.
carbon tetrachloride
H
55.
naphthalene
H
7.
chlorobenzene
H
56.
nitrobenzene
H
8.
1,2,4-trichlorobenzene
H
57.
2-nitrophenol
H
9.
hexachlorobenzene
H
58.
4-nitrophenol
H
10.
1,2-dichloroethane
M
59.
2,4-dinitrophenol
H
11.
1,1,1-trichloroethane
M
60.
4,6-dinitro-o-cresol
H
12.
hexachloroethane
K
61.
N-nitrosodimethylamine
M
13.
1,1-dichloroethane
M
62.
N-nitrosodiphenylamine
H
14.
1,1,2-trichloroethane
K
63.
N-nitrosodi-n-propylamine
M
15.
1,1,2,2-tetrachloroethane
H
64.
pentachlorophenol
H
16.
chloroethane
L
65.
phenol
M
18.
bis (2-chloroethyl) ether
M
66.
bis{2-ethylhexyl) phthalate
H
19.
2-chloroethyl vinyl ether
L
67.
butyl benzyl phthalate
H
20.
2-chloronaphthalene
H
68.
ai-n-butyl phthalate
H
21.
2, 4 , 6-trichlorophenol
H
69.
di-n-octyl phthalate
H
22.
parachlorometa cresol
H
70.
diethyl phthalate
H
23.
chloroform (trichloromethane) L
71.
dimethyl phthalate
H
24.
2-chlorophenol
H
72.
benzo {a)anthracene
H
25.
1,2-dichlorobenzeneH
73.
benzo (a)pyrene
H
26.
1,3-dichlorobenzene
H
74.
3,4-benzofluoranthene
H
27.
1,4-dichlorobenzene
H
75.
benzo(k)fluoranthane
H
28.
3,3'-dichlorobenzidine
H
76.
chrysene
H
29.
1,1-dichloroethylene
L
77.
acenaphthylene
H
30.
1,2-trans-dichloroethylene
L
78.
anthracene
H
31.
2,4-dichlorophenol
H
79.
benzofghi)perylene
H
32.
1,2-dichloropropane
M
80.
fluorene
H
33.
1,2-dichloropropylene
M
81.
phenanthrene
H
34.
2,4-dimethylphenol
H
82.
dibenzo (a,h)anthracene
H
35.
2,4-dinitrotoluene
H
83.
indeno (1,2,3-cd)pyrene
H
36.
2,6-dinitrotoluene
H
84.
pyrene
_
37.
1,2-diphenylhydrazine
H
85.
tetrachloroethylene
M
38.
ethylbenzene
M
86.
toluene
M
39.
fluoranthene
H
87.
trichloroethylene
L
40.
4-chlorophenyl phenyl ether
H
88.
vinyl chloride
L
41.
4-brornophenyl phenyl ether
K
106.
PCB-1242 (Arochlor 1242)
H
42.
bis(2-chloroisopropyl) ether M
107.
PCB-1254 (Arochlor 1254)
H
43.
bis(2-choroethoxy) methane
M
108.
PC3-1221 (Arochlor 1221)
H
44.
methylene chloride
L
109.
PCB-1232 (Arochlor 1232)
H
45.
methyl chloride
L
110.
PCB-1248 (Arochlor 1248)
H
46.
methyl bromide
L
111.
PCB-1260 (Arochlor 1260)
H
47.
bromoform (tribromomethane)
K
112.
PCB-1016 (Arochlor 1016)
H
Category H (high removal)
Adsorbs at levels >100 mg/g carbon at Cg =10 mg/1
Adsorbs at levels >100 mg/g carbon at Cf <10 mg/1
Category M (high removal)
Adsorbs at levels >100 mg/g carbon at Cf =10 mg/1
Adsorbs at levels <100 mg/g carbon at Cf <10 mg/1
Category L (high removal)
Adsorbs at levels <100 mg/g carbon at Cf =10 mg/1
Adsorbs at levels <100 mg/g carbon at Cf <10 mg/1
Cf = final concentration of priority pollutant at equilibrium.
249
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
TABLE VII-23
CLASSES OP ORGANIC COMPOUNDS ADSORBED ON CARBON
Organic Chemical Class
Aromatic Hydrocarbons
Polynuclear Hydrocarbons
Chlorinated Aroroatics
Phenolics
Chlorinated Phenolics
High Molecular Weight Alphatic
and Branch Chain Hydrocarbons
Chlorinated Alphatic Hydrocarbons
High Molecular Weight Alphatic
Acids and Aromatic Acids
High Molecular Weight Alphatic
Amines and Aromatic Amines
High Molecular Weight Ketones,
Esters, Ethers and Alcohols
Surfactants
Soluble Organic Dyes
Example of Chemical Class
Benzene, toluene, xylene
Napthalene, anthracene,
biphenols
Chlorobenzene, pollychlorinated
biphenyls, aldrin, endrin
Phenol, cresol, resorcenol,
polyphenyls
Trichlorophenol,
pentachlorophenol
Gasoline, kerosine
Carbon tetrachloride,
chlorethylenes
Tar acids, benzoic acid
analine, toluene, diamine
Hydroquinone, polyethylene
glycol
alkyl benzene sulfonates
Melkylene blue, Indigo carmine
High molecular weight includes compounds in the broad range from
four to 20 carbon atoms.
250
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
TABLE VI1-24
ACTIVATED CARBON PERFORMANCE (MERCURY)
Plant
A
B
C
Mercury levels (mg/1)
28.0
0,36
0.008
0.9
0.015
0.0005
Parameter
Al
Cd
Cr
+ 3
+6
Cr
Cu
CN
Au
Fe
Pb
Mn
Ni
Ag
S04
Sn
Zn
TABLE VII-25
ION EXCHANGE PERFORMANCE
(mg/1)
Plant A
In
5.6
5.7
3.1
7.1
4.5
9.8
7.4
4.4
6.2
1.5
1.7
14.8
Out
0.20
0.00
0.01
0.01
0.09
0.04
0.01
0.00
0 .00
0.00
0.00
0.40
Plant B
In
43.0
3.40
2. 30
1.79
1.60
9.10
210.00
1.10
Out
0.10
0.09
0.10
0 .01
0.01
0.01
2.00
0.10
251
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
TABLE VI1-26
MEMBRANE FILTRATION SYSTEM EFFLUENT
Specific Manufacturers Plant 19066 Plant 31022 Predicted
Metal Guarantee In Out In Out Performance
Al 0.5
Cr+6 0.02 0.46 0.01 5.25 <0.005
Cr (T) 0.03 4.13 0.018 98.4 0.057 0.05
Cu 0.1 18.8 0.043 8.00 0.222 0.02
Fe 0.1 288 0.3 21.1 0.263 0.30
Pb 0.05 0.652 0.01 0.288 0.01 0.05
CN 0.02 <0.005 <0.005 <0.005 <0.005 0.02
Ni 0.1 9.56 0.017 194 0.352 0.40
Zn 0.1 2.09 0.046 5.00 0.051 0.10
TSS 632 0.1 13.0 8.0 1.0
TABLE VII-27
PEAT ADSORPTION PERFORMANCE
(mg/1)
Pollutant In Out
Cr*6 35000 0.04
Cu 250 0.24
CN 36.0 0.7
Pb 20.0 0.025
Hg 1.0 0.02
Ni 2.5 0.07
Ag 1.0 0.05
Sb 2.5 0.9
Zn 1.5 0.25
252
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
TABLE VII-20
ULTRAFILTRATION PERFORMANCE
Parameter Feed (rag/1) Permeate (mq/1)
t * .... J/ /
Oil (Freon extractable) 1230 4
COD 8920 148
TSS 1380 13
Total Solids 2900 296
253
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
to
10
10
Zn(OH)
Cd (OH j
10
10
Cu (OH)
COS
ZnS
CdS
10"
1
9
7
2
4
a
10
11
12
I S
pH
FIGURE VII -1. COMPARATIVE SOLUBILITIES OF METAL HYDROXIDES
AND SULFIDE AS A FUNCTION OF pH
254
-------
t o 9 i u
MINIMUM EFFLUENT pH
FIGURE VII 2 EFFLUENT ZINC CONCENTRATION VS. MINIMUM EFFLUENT pH
-------
GENERAL DEVELOPMENT DOCUMENT
SECT - VII
CAUSTIC SODA
SODA ASH AND
CAUSTIC SODA
FIGURE VII • 3 LEAD SOLUBILITY IN THREE ALKALIES
256
-------
1.0
c
o
C_3
0.1
NJ
Ln
E
a
J.01
1
.
i
i
|
V
|
i
a
!
I
1
1—
:
i
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i
1
1
i
,
i
f
1
I
|
-
!
i
|
I
t
{
i
1
i
i
i
i
7—
i
!
i
i
1
—
1
t
i
/2
£l.
0.01
Data points with a raw waste concentration
less than 0.1 mg/l were not included in
treatment effectiveness calculations.
0.1
1.0
Cadmium RawWaste Concentration (rng/l)
10 100
(Number of observations = 2)
FIGURE VII-4
HYDROXIDE PRECIPITATION SEDIMENTATION EFFECTIVENESS
CADMIUM
en
m
55
M
PO
>
f
a
w
<
M
O
hd
2
W
a
o
o
c:
s
M
55
t-3
Ul
w
o
1-3
<
M
M
-------
10
t\J
Ul
oo
©
o
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to
01
E
a
1.0
0.1
0.01
i,
)
<
p
$
}
0
€
9
$
<
)
(s
®
a
©
ft
X
T
a
0.1
1.0
10
Chromium Raw Waste Concentration (mg/l)
100 1000
(Number of observations = 25}
o
M
Z
M
t-i
a
m
<
m
t->
o
3
W
2!
H
8
o
M
25
n3
in
M
O
H3
1
<
FIGURE VII - 5
HYDROXIDE PRECIPITATION SEDIMENTATION EFFECTIVENESS
CHROMIUM
-------
10
©
©
1.0
ۥ
©"
IT
C)
0.1
j£L
o
w
2
w
50
>
t"1
O
M
<
W
tr>
O
~o
2
M
i-3
O
o
o
G
3
w
52
t-3
0.01
-
-------
1.0
c
o
a
u
NJ
CTi
o
0.1
0.01
0.001
f
©
0
-
©
oK&ca a
to
c
i.
0.01
0.1
1.0
Lead Raw Waste Concentration (my/I)
10 100
(Number of observations = 22)
O
M
Z
W
»
>
f
a
w
<
M
IT1
O
~d
3
H
e:
H
O
o
a
a
3
M
2:
H
w
w
o
H3
<
H
FIGURE VII-7
HYDROXIDE PRECIPITATION SEDIMENTATION EFFECTIVENESS
LEAD
-------
10
x
en
-E —
OS
S £
£5 ©
i 1
g =
O u
1.0
to
CTi
si
a
E £
? •-
i 2
u
< 2
0.1
©
Js
0 01
s-
<3
B«2l
&
©
X
X X
0.1
1.0 10
® Nickel Raw Waste Concentration (my/I)
x Aluminum Raw Waste Concentration (my/I)
100
(Number of observations = 12)
(Number of observations = 11)
1000
FIGURE VII-8
HYDROXIDE PRECIPITATION SEDIMENTATION EFFECTIVENESS
NICKEL AND ALUMINUM
Q
M
S3
M
ta
>
lr"
a
w
<
w
f
O
*x)
S
M
Z
O
O
o
G
3
w
z
w
M
O
H
<
tH
H
-------
10
1.0
0.1
0.01
0.
1
-------
10
®
©
1.0
¦«»-
JSC
C
o
e
o
C3
igf-
ISL
s®
©
KJ
cn
UJ
i r
-<^h
iSr
"ST
0.1
c
~
©
-€0-
Q
ra
25
M
>
t"1
a
w
<
R
t"1
O
13
2
M
2
i-3
O
O
o
a
2
M
52
H
ir
w
M
o
1-3
0.01
0.1
1.0
10
Iron Raw Waste Concentration (my/1)
100 1000
(Number of observations = 28)
FIGURE VII-10
HYDROXIDE PRECIPITATION SEDIMENTATION EFFECTIVENESS
IRON
-------
1.0
§ 0.1
¦J3
e
E
a
c
o
CJ
»-
ISJ
cr»
s
»_
~—
| 0.01
8.
C
2
0 001
o.i
1.0 10
Manpnese Raw Waste Concentration (mg/l)
100 1000
(Number of observations = 10)
FIGURE VII-11
HYDROXIDE PRECIPITATION SEDIMENTATION EFFECTIVENESS
MANGANESE
-------
1.0 10 100 1000 10,000
TSS Raw Waste Concentration (mg/l)
(Number of observations = 45}
FIGURE VII-12
HYDROXIDE PRECIPITATION SEDIMENTATION EFFECTIVENESS
TSS
-------
SULFURIC SULFUR
ACID DIOXIDE
LIME OR CAUSTIC
tsj
£T>
0%
1 t
i .
i i
pH CONTROLLER
pH CONTROLLER
ORPCONTROLLER
RAW WASTE'. i
(HEXAVALCNT CHROMIUM)
ob
TRIVALENT CHROMIUM}
TO CLARIFIER
(CHROMIUM
HYDROXIDE)
PRECIPITATION TANK
REACTION TANK
o
M
25
W
5
a
w
tr"
o
2!
h3
a
w
w
n
<
M
FIGURE VII-13. HEXAVALENT CHROMIUM REDUCTION WITH SULFUR DIOXIDE
-------
GENERAL DEVELOPMENT DOCUMENT SECT
- VII
INFLUENT
ALUM
EFFLUENT
POLYMER
STORED
BACKWASH
WATER
-•—FILTER
BACKWASH
THREE WAY VALVE
FILTER
COMPARTMENT
COAL
SAN
COLLECTION CHAMBER
SUMP
DRAIN
FIGURE VII-14. GRANULAR BED FILTRATION
267
-------
GENERAL DEVELOPMENT DOCUMENT SECT -VII
PERFORATED
BACKING PLATE
FABRIC
FILTER MEDIUM
SOLID
RECTANGULAR
END PLATE
INLET
SLUDGE
FABRIC
FILTER MEDIUM
Entrapped solids
PLATES AND FRAMES ARE
PRESSED TOGETHER DURING
FILTRATION CYCLE
RECTANGULAR
METAL PLATE
FILTERED LIQUID OUTLET
RECTANGULAR FRAME
FIGURE VIMS. PRESSURE FILTRATION
268
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
FLANGE
- BACKWASH
WASTE WATER
INFLUENT-
DISTRIBUTOR
REPLACEMENT CARBON
WASH WATER
SURFACE WASH
MANIFOLD
CARBON BED
CARBON REMOVAL PORT
TREATED WATER
BACKWASH
SUPPORT PLATE
FIGURE VII-17. ACTIVATED CARBON ADSORPTION COLUMN
270
-------
GENERAL DEVELOPMENT DOCUMENT
SECT - VII
SEDIMENTATION BASIN
INLET ZONE
INLET LIQUID
BAFFLES TO MAINTAIN
QUIESCENT CONDITIONS
OUTLET ZONE
* SETTLING PARTICLE
* * • *****«-„.* > TRAJECTORY , •
• * • * * *. . • 1 • •
5
OUTLET LIQUID
• * •• *
BELT-TYPE SOLIDS COLLECTION
MECHANISM
SETTLED PARTICLES COLLECTED
AND PERIODICALLY REMOVED
CIRCULAR CLARIFIER
SETTLING 20NE
INLET LIQUID
CIRCULAR BAFFLE
NLET ZONE
• i
' V*.* FLOW .
• • .' .T -T t* T» •
ANNULAR OVERFLOW WEIR
OUTLET LIQUID
REVOLVING COLLECTION
MECHANISM
SETTLING PARTICLES
SETTLED PARTICLES
COLLECTED AND PERIODICALLY
REMOVED
SLUDGE DRAWOFF
FIGURE V11-16. REPRESENTATIVE TYPES OF SEDIMENTATION
269
-------
GENERAL DEVELOPMENT DOCUMENT SECT
- VII
LIQUID
OUTLET
DRYING
ZONE
CONVEYOR DRIVE
L1QU
ZONE
BOWL DRIVE
a
SLUDGE
INLET
.i-rfV .1^ —TT-
>»
SLUDGE
DISCHARGE
CYCLOGEAR
CONVEYOR
BOWL
REGULATING
RING
FIGURE VII - 18. CENTRIFUGATION
271
-------
RAW WASTE
CAUSTIC
SODA
NJ
-J
KJ
ORPCONTBOLLEHS
CAUSTIC
SODA
PH
CONTROLLER
WATER
CONTAINING
CVANATE
TREATED
WASTE
CIRCULATING
PUMP
CHLORINE
REACTION TANK
REACTION TANK
CHLORINATOR
Q
M
55
W
*>
>
f4
o
m
<
m
t-1
o
u
3
W
z
t-i
O
o
o
c
3
M
z
t-3
W
M
0
H
1
<
Ml
H
FIGURE VII-19. TREATMENT OF CYANIDE WASTE BY ALKALINE CHLORINATION
-------
GENERAL DEVELOPMENT DOCUMENT
treated
waste
OZONE
REACTION
TANK
CONTROLS
OZONE
GENERATOR
DRY AIR
RAW WASTE
FIGURE VII - 20, TYPICAL OZONE PLANT FOR WASTE TREATMENT
273
-------
GENERAL DEVELOPMENT DOCUMENT
SECT - VII
EXHAUST
GAS
TEMPERATURE
CONTROL
PH MONITORING
TEMPERATURE
CONTROL
SECOND
STAGE
PH MONITORING
TEMPERATURE
CONTROL
THIRD
STAGE
EWATER
TANK
PH MONITORING
OZONE
GENERATOR
OZONE
TREATED WATER
FIGURE VII-21. UV/OZONATION
274
-------
EXHAUST
CONDENSER
ISJ
-vj
Ln
EVAPORATOR
WATER VAPOR
packed tower
EVAPORATOR
Mr A STEM ATER
FAN
vapoh-liquid
MIXTURE / SEPARATOR
.JT
' n\
11 i
HEAT
EXCHANGER
"STEAM
STEAM
CONDENSATE
STEAM-
STEAM
CONDENSATE
* CONCENTRATE
TURE / *»*.
^ /f
n
/
/
/
~
/
~
~
/
/
X
_
~
r AT EH VAPOR
RETURN
ATMOSPHERIC EVAPORATOR
WASTEWATER
r-J.
COOLING
WATER
c±£3
,CONDENSATE
VACUUM CUMf
CONCENTRATE
CLIMBING FIC.M E V AfOH ATON
VAPON
CONDENSATE
WASTEWATER
CONCENTRATE
VACUUM
VACUUM LI
COOLING
HOT V APQlf
PU MP
WATER
WATER
STEAM
CONDENSATE
CONOEN
SATE
STEAM
WASTE
WATER
CONCENTRATE
FEED
(CONDENSATE
VACUUM PUMP
EXHAUST
ACCUMULATOR
CONDENSATE
FOR REUSE
STEAM
CONDENSATE
SUBMERGED TUBE EVAPORATOR
CONCENTRATE FOR REUSE
DOUULt EfFECT EVAPORATOR
a
M
52
M
W
>
O
w
<
w
f
o
Ha
3
PJ
3
i-3
U
o
n
a
2
w
55
H
CO
M
o
>-3
FIGURE VII-22. TYPES OF EVAPORATION EQUIPMENT
-------
GENERAL DEVELOPMENT DOCUMENT
SECT
- VII
WATER
DISCHARGE
OILY WATER
INFLUENT
OVERFLOW
SHUTOrr
VALVE
MOTOR
DRIVEN
RAKE
AIR IN
BACK PRESS
VALVE
1
FINES a> o
OUT
EJECTOR
EXCESS
AIR OUT
LEVEL
CONTROLLER
HOLDING
TANK
RECYCLE
WATER
TO SLUDGE
TANK ""
FIGURE VII - 23. DISSOLVED AIR FLOTATION
276
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
RAKE ARM
BLADE
COUNTERBLOW
INFLUENT WELL
CONDUIT
TO MOTOR
DRIVE UNIT
INFLUENT
WALKWAY
CONDUIT TO
OVERLOAD
ALARM
OVERLOAD ALARM
EFFLUENT WEIR
DIRECTION OF ROTATION
EFFLUENT PIPE
EFFLUENT CHANNEL
PLAN
TURNTABLE
BASE
HANDRAIL
DRIVE
WATER LEVEL
CENTER COLUMN
INFLUENT
CENTER CASE
FEED WELL
SQUEESEE
STILTS
SLUDGE PIPE
CENTER SCRAPER
FIGURE VII -24. GRAVITY THICKENING
277
-------
GENERAL DEVELOPMENT DOCUMENT
SECT
VII
WASTE WATER CONTAINING
DISSOLVED METALS OR
OTHER IONS
DIVERTER VALVE
REGENERANT
SOLUTION
DISTRIBUTOR
SUPPORT
REGENERANT TO REUSE,
TREATMENT, OR DISPOSAL
-DIVERTER VALVE
METAL-FREE WATER
rOR REUSE OR DISCHARGE
FIGURE VII • 25. ION EXCHANGE WITH REGENERATION
278
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VII
# MACROMOLECULES
# AND SOLIDS
.... ••
SALTS & • _
• • r ~
• MOST
MEMBRANE
A P « 450 PSlI
WATER
PERMEATE (WATER)
-MEMBRANE CROSS SECTION,
IN TUBULAR. HOLLOW TIBER,
OR SPIRAL-WOUND CONFIGURATION
• * T f I* • 9 »T •
• • • O ° • n 9/ o .0 I r
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279
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
PERMEATE
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FIGURE VII - 27. REVERSE OSMOSIS MEMBRANE CONFIGURATIONS
280
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GENERAL DEVELOPMENT DOCUMENT
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281
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
ULTRAFILTRATION
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FIGURE VII -29. SIMPLIFIED ULTRAFILTRATION FLOW SCHEMATIC
282
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
FABRIC OR WIRE
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GENERAL DEVELOPMENT DOCUMENT SECT - VII
EVAPORATION
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FLOW DIAGRAM FOR RECYCLING WITH A COOLING TOWER
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
SECTION VIII
COST OF WASTEWATER TREATMENT AND CONTROL
This section contains a summary of cost estimates, a discussion
of the cost methodology used to develop these estimates, and
descriptions of the equipment and assumptions for each individual
treatment technology. These cost estimates, together with the
estimated pollutant reduction performance for each treatment and
control option presented in Sections IX, X, XI, and XII of the
subcategory supplements, provide a basis for evaluating each
regulatory option, as well as for identification of the best
practicable technology currently available (BPT), best available
technology economically achievable (BAT), best demonstrated
technology (BDT), and the appropriate technology for pretreatment
standards. The cost estimates also provide the basis for
determining the probable economic impact of regulation on the
category at different pollutant discharge levels. In addition,
this section addresses nonwater quality environmental impacts of
wastewater treatment and control alternatives, including air
pollution, solid wastes, and energy requirements.
SUMMARY OF COST ESTIMATES
The total capital and annual costs of compliance with the
promulgated regulation are presented by subcategory in Tables
VIII-1 through VIII 3 (pages 327-329) for regulatory options BPT,
BAT, and FSES, respectively. The number of direct and indirect
discharging plants in each subcategory is also shown. The
methodology used to obtain these plant cost estimates is
described in the following sections.
COST ESTIMATION METHODOLOGY
Two general approaches to cost estimation are possible. The
first is a plant-by-plant approach in which costs are estimated
for each individual plant in the category. Alternatively, in a
model plant approach, costs can be projected for an entire
category (or subcategory) based on cost estimates for an
appropriately selected subset of plants. The plant-by-plant cost
estimation procedure is usually more accurate compared with the
model plant approach because it affords a higher degree of
flexibility and maximizes the use of plant specific data. For
the nonferrous metals manufacturing category, the plant-by-plant
approach was adopted.
For the primary aluminum, secondary aluminum, primary copper
smelting, primary copper electrolytic refining, primary lead,
primary zinc, primary columbiurn-tantalum, primary tungsten,
secondary silver, secondary copper, secondary lead, and
metallurgical acid plants subcategories, the Agency revised its
cost estimation methodology between proposal and promulgation of
effluent limitations.
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
The revisions are based on a more detailed engineering analysis
of each plant so that estimated costs better represent actual
cost to each plant for compliance with the regulations. The
revised methodology also reflects the comments received by the
Agency on its cost estimation approach. The pre- and post-
proposal cost estimation methodologies are, in general, very
similar. The major revisions in the methodology are listed
below.
(1) The revised approach made greater use of plant-specific
data for treatment system design and equipment information for
costs.
(2) Treatment-in-place was considered.
(3) The method of determining the flow rate of wastewater
into the treatment system was revised.
(4) Specific design and cost assumptions were revised.
(5) The method of calculating the pollutant loading in each
waste stream was revised.
(6) The chemical precipitation system configuration was
simplified.
(7) Costs for contract hauling of nonhazardous wastes were
revised.
(8) Enclosure costs were revised.
To implement the revised approach, the wastewater characteristics
and appropriate treatment technologies for the category were
identified. These are discussed in Section V of each subcategory
supplement and Section VII of this document, respectively. Based
on a preliminary technical and economic evaluation, the model
treatment systems were developed for each regulatory option from
the available set of treatment processes. When these systems
were established, a cost data base is developed containing
capital and operating costs for each applicable technology. To
apply this data base to each plant for cost estimation, the
following steps were taken:
1. Define the components of the treatment system (e.g.,
chemical precipitation, multimedia filtration) and their sequence
that are applicable to the waste streams under consideration.
2. Define the flows and pollutant concentrat ions of the
waste streams entering the treatment system.
3. Estimate capital and annual costs for this treatment
system.
4. Estimate the actual compliance costs by accounting for
existing treatment inplace.
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
5. Repeat steps 1-4 for each regulatory option.
Because of the large number of plants in the category and to
provide a greater degree of accuracy, the above steps were
accomplished by development of a computer-based cost estimation
model for the nonferrous metals manufacturing category and
related categories with similar treatment technology. This model
represents the key element in the plant-by-plant cost estimation
approach.
Each of the steps involved in the cost estimation methodology
outlined above is described in more detail below.
Cost Data Base Development
A step required prior to cost estimation is the development
of a cost data base, which includes the compilation of cost
data and standardization of the data to a common dollar
basis. Capital and annual cost data for the selected treatment
processes were obtained from three sources: (1) equipment
manufacturers and vendors, (2) literature data, and (3) cost data
from existing plants. The major source of equipment costs was
contacts with equipment vendors, while the majority of annual
cost information was obtained from in-house files and the
literature. Additional cost and design data were obtained from
data collection portfolios when possible. The components of the
cost estimates, the sources of cost data, and the update
factors used for standardization (to March 1982 dollars) are
described below.
Components of Costs
The components of the capital and annual costs and the
terminology used in this study are presented here in order to
ensure unambiguous interpretation of the cost estimates and cost
curves included in this section.
Capital Costs. The total capital costs consist of two major
components: direct, or total module capital costs and indirect,
or system capital costs. The direct capital costs include:
(1) Purchased equipment cost.
(2) Delivery charges (based on a shipping distance of 500
miles), and
(3) Installation (including labor, excavation, site work,
and materials) .
The direct components of the total capital cost are derived
separately for each unit process, or treatment technology. Each
unit process cost comprises individual equipment costs (e.g.,
pumps, tanks, feed systems, etc.). The correlating equations
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
used to generate the individual equipment costs are presented in
Table VIII-4 (page 330).
Indirect capital costs consist of contingency, engineering and
contractor fees. These indirect costs are derived from factored
estimates (i.e., they are estimated as percentages of a subtotal
of the total capital cost, as shown in Table VIII-5 (page 341)).
Annual Costs. The total annualized costs also consist of a
direct and a system component as in the case of total capital
costs. The components of the total annualized costs are listed
in Table VIII-6 (page 340). Direct annual costs include the
following:
Raw materials - These costs are for chemicals and other
materials used in the treatment processes, which may include
lime, caustic, sodium sulfide, activated carbon, sulfuric
acid, ferrous sulfate, and polyelectrolyte.
Operating labor and materials - These costs account for the
labor and materials directly associated with operation of
the process equipment. Labor requirements are estimated in
terms of hours per year. A labor rate of $21 per hour was
used to convert the hour requirements into an annual cost.
This composite labor rate included a base labor rate of $9
per hour for skilled labor, 15 percent of the base labor
rate for supervision and plant overhead at 100 percent of
the total labor rate. The base labor rate was obtained from
the "Monthly Labor Review," which is published by the Bureau
of Labor Statistics of the U.S. Department of Labor. For
the metals industry, this wage rate was approximately $9 per
hour in March of 1982.
Maintenance labor and materials - These costs account for
the labor and materials required for repair and routine
maintenance of the equipment. They are based on information
gathered from the open literature and from equipment
vendors.
Energy - Energy, or power, costs are calculated based on
total energy requirements (in kw-hrs). an electricity charge
of $0.0483/kilowatt-hour and an operating schedule of 24
hours/day, 250 days/year unless otherwise specified. The
electricity charge rate (March 1982) is based on the average
retail electricity prices charged for industrial service by
selected Class A privately-owned utilities, as reported in
the Department of Energy's Monthly Energy Review.
System annual costs include monitoring, insurance and
amortization. Monitoring refers to the periodic analysis of
wastewater effluent samples to ensure that discharge limitations
are being met. The annual cost of monitoring was calculated
using an analytical lab fee of $120 per wastewater sample and a
sampling frequency based on the wastewater discharge rate, as
shown in Table VII1-7 (page 343). The values shown in Table
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
VIII-7 represent typical requirements contained in NPDES permits.
For the economic impact analysis, the Agency also estimated
monitoring costs based on 10 samples per month, which is
consistent with the statistical basis for the monthly effluent
limitations,
The cost of taxes and insurance is assumed to be one percent of
the total depreciable capital investment.
Amortization costs, which account for depreciation and the cost
of financing, were calculated using a capital recovery factor
(CRF). A CRF value of 0.177 was used, which is based on an
interest rate of 12 percent, and a taxable lifetime of 10 years.
The CRF is multiplied by the total depreciable investment to
obtain the annual amortization costs.
Standardization of Cost Data
All capital and annual cost data completed were standardized by
adjusting to March 1982 dollars based on the following cost
indices.
Capital Investment. Investment costs were adjusted using the
EPA-Sewage Treatment Plant Construction Cost Index. The value of
this index for March 1982 is 414.0.
Chemicals. The Chemical Engineering Producer Price Index for
industrial chemicals was used. This index is published biweekly
in Chemical Engineering magazine. The March 1982 value of this
index is 362.6.
Energy. Power costs were adjusted by using the price of
electricity on the desired date and multiplying it by the energy
requirements for the treatment module in kw-hr equivalents. The
industrial charge rate for electricity for March 1982 is $0.0483
per kw-hr as mentioned previously in the annual costs discussion.
Labor. Annual labor costs were adjusted by multiplying the
hourly labor rate by the labor requirements {in man-hours), if
the latter is known. The labor rate for March 1982 was computed
to be 21 dollars per hour as discussed above. In cases where the
man-hour requirements are unknown, the annual labor costs are
updated using cost indices. The ENR Skilled Labor Index was used
for the primary aluminum, primary copper smelting, primary copper
electrolytic refining, primary lead, primary zi nc, primary
columbium-tantalum, primary tungsten, secondary aluminum,
secondary silver, secondary copper, secondary lead, and
metallurgical acid plants subcategories. The value of this index
for March 1982 is 3,256.23. For all other subcategories in this
rulemaking the EPA-Sewage Treatment Plant Construction Cost
Index was used. The value of this index for March 1982, is 414.0
as stated above.
Plant Specific Flowsheet
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
When the cost data base has been developed, the first step of the
cost estimation procedure is the selection of the appropriate
treatment technologies and their sequence for a particular plant.
These are determined for a given option by applying the general
treatment diagram for that subcategory to the plant, which is
then modified as appropriate to reflect the treatment
technologies that the plant will require. For instance, one plant
in a subcategory may generate wastewater from a certain operation
that requires oil-water separation. Another plant in the same
subcategory may not generate this waste stream and thus does not
require oil-water separation technology. The specific plant
flowsheets will reflect this difference.
Wastewater Characteristics
Upon establishing the flowsheet required for a given plant, the
next step is to define the influent waste stream characteristics
(flow and pollutant concentrations).
The list of pollutants which may influence the design (and thus
the cost) of the treatment system is shown in Table VIII-8. This
list includes the conventional pollutants, and priority metal and
selected nonconventional pollutants that are generally found in
metal-bearing waste streams. Inclusion of these pollutants
allows the model to account for the effects of varying influent
concentrations upon the various wastewater treatment processes.
For example, influent waste streams with high metals loadings
require a greater volume of precipitant (such as lime) and
generate a greater amount of sludge than wastestreams with lower
metals concentrations.
The raw waste concentrations of pollutants present in the
influent waste streams for cost estimation were based primarily
on field sampling data. A production normalized raw waste value
in milligrams of pollutant per metric ton of production was
calculated for each pollutant by multiplying the measured
concentration by the cor responding waste stream flow and dividing
this result by the corresponding production associated with
generation of the waste stream. These raw waste values are
averaged across all sampled plants where the waste stream is
found. These final raw waste values are used in the cost
estimation procedure to establish influent pollutant loadings to
each plant's treatment system. The underlying assumption in this
approach is that the amount of pollutant that is discharged by a
process is a function only of the amount of product that is
generated by the process (or in some cases, the amount of raw
material used in the process). The amount of water used in the
processes is assumed to not have an affect on the pollutant
quantity discharged. This assumption is also called the constant
mass assumption since the mass of pollutant discharged remains
the same even if the flow of water carrying the pollutant is
changed.
The individual flows for cost estimation are determined for each
waste stream. The procedure used to derive these flows is as
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GENERAL DEVELOPMENT DOCUMENT SECT -VIII
follows:
{1} The production normalized flows (1/kkg) were determined
for each waste stream based on production (kkg/yr) and current
flow (1/yr) data obtained from each plant's dcp or trip report
data where possible.
(2) This flow was compared to the regulatory flow allowance
(1/kkg) established by the Agency for each waste stream.
(3) The lower of the two flows was selected as the cost
estimation flow. The flow in 1/yr is calculated by multiplying
the selected flow by the production associated with that waste
stream.
(4) The regulatory flow was assigned to waste streams for
which actual flow rate data were unavailable for a plant.
Treatment System Cost Estimation
Once the treatment system and waste stream characteristics have
been defined, they can be used as input to the cost estimation
step, which is based on the cost estimation model and general
cost assumptions described below.
Cost Estimation Model
The computer-based cost estimation model was designed to provide
conceptual wastewater treatment design and cost estimates based
on wastewater flows, pollutant loadings, and unit operations that
are specified by the user. The model was developed using a
modular approach; that is, individual wastewater treatment
processes such as gravity settling are contained in
semiindependent entities known as modules. These modules are
used as building blocks in the determination of the treatment
system flow diagram. Because this approach allows substantial
flexibility in treatment system cost estimation, the model did
not require modification for each regulatory option.
Each module was developed by coupling design information from the
technical literature with actual design data from operating
plants. This results in a more realistic design than using
either theoretical or actual data alone, and correspondingly more
accurate cost estimates. The fundamental units for cost
estimation are not the modules themselves but the components
within each module. These components range in configuration from
a single piece of equipment such as a pump to components with
several individual pieces, such as a lime feed system. Each
component is sized based on one or more fundamental parameters.
For instance, the lime feed system is sized by calculating the
lime dosage required to adjust the pH of the influent to 9 and
precipitate dissolved pollutants. Thus, a larger feed system
would be designed for a chemical precipitation unit treating
effluent containing high concentrations to dissolved metals 'than
for one treating effluent of the same flow rate but lower metals
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
loadings. This flexibility in design results in a treatment
system tailored to each plant's wastewater characteristics.
The cost estimation model consists to four main parts, or
categories of programs:
User input programs.
Design and simulation programs,
Cost estimation programs, and
Auxiliary programs.
A general logic diagram depicting the overall calculational
sequence is shown in Figure VIil-1 (page 350).
The user input programs allow entry of all data required by the
model, including the plant-specific flowsheet, flow and
composition data for each waste stream, and specification of
recycle loops. The design portion of the model calculates the
design parameter for each module of the flowsheet based on the
user input and material balances performed around each module.
Figure VII1-2 (page 351) depicts the logic flow diagram for the
design portion of the model.
The design parameters are used as input to the cost estimation
programs to calculate the costs for each module equipment
component (individual correlating cost equations were developed
for each of these components). The total direct capital and
annual costs are equal to the sum of the module capital and
annual costs, respectively. System, or indirect costs (e.g.,
engineering, amortization) are then calculated (see Tables VIII-
5, and VIII-6 (pages 341 and 342)) and added to the total direct
costs to obtain the total system costs. The logic flow for the
cost estimation programs is displayed in Figure VIII-3 (page
352). The auxiliary programs store and transfer the final cost
estimates to data files, which are then used to generate final
summary tables (see Table VIII-10, page 347, for a sample summary
table).
General Cost Assumptions
The following general assumptions apply to cost estimation
in all subcategories:
(1) Unless otherwise specified, all wastewater treatment
sludges are considered to be nonhazardous.
(2) In cases in which a single plant has wastewater
generating processes associated with different nonferrous metals
manufacturing subcategories, costs are estimated for a single
treatment system. In most cases, the combined treatment system
costs are then apportioned between subcategories on a flow-
weighted basis since hydraulic flow is the primary determinant of
equipment size and cost. It is possible, however, for the
combined treatment system to include a treatment module that is
required by only one of the associated subcategories. In this
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
case, the total costs for that particular module are included in
the costs for the subcategory which requires the module. Where
the module in question involves flow reduction, the costs are
apportioned based on an influent flow weighted basis. Such cost
apportioning is essentially only a bookkeeping exercise to
allocate costs because the total costs calculated for the plant
remain the same.
(3) In most cases, where a plant has wastewater sources
from the nonferrous metals manufacturing category and a category
other than nonferrous manufacturing (for example, nonferrous
forming) costs are calculated for segregating these different
wastewaters. This means of cost estimation accounts for the
possibility that respective regulations for each category are
based on different technologies {and may control different
pollutants).
Consideration of Existing Treatment
The cost estimates calculated by the model represent "greenfield
costs" that do not account for equipment that plants may already
have in place, i.e.. these costs include existing treatment
equipment. In order to estimate the actual compliance cost
incurred by a plant to meet the effluent guidelines, "credit"
should be given to account for treatment in place at that plant.
This was accomplished by subtracting capital costs of treatment
in-place {as estimated by the model) from the "greenfield costs"
to obtain the actual or required capital costs of compliance.
Annual costs associated with treatment in place (as estimated by
the model), however, are not subtracted because these costs recur
and must be borne by the facility each year. Further, inclusion
of these annual costs ensures that EPA adequately considers the
costs for proper operation of each module in the treatment
system. For an example the reader is referred to Table VIII-10,
(page 347 which presents compliance cost estimates for a plant
that has chemical precipitation of sufficient capacity already in
place.
Existing treatment is considered as such only if the capacity and
performance of the existing equipment (measured in terms of
estimated ability to meet the effluent limitations) is
equivalent to that of the technologies considered by the Agency.
The primary source of information regarding existing treatment
was data collection portfolios (dcps).
General assumptions applying to all subcategories used for
determining treatment in place qualifications in specific
instances include:
(1) In cases in which existing equipment has adequate
performance but insufficient capacity, the plant is assumed to
comply by either installing additional required capacity to
supplement the existing equipment or disregarding the existing
equipment and installing new equipment to treat the entire
flow. This selection was based on the lowest total annualized
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
cost.
(2) When a plant reported recycle of treatment plant
sludges, capital and annual costs for sludge handling (vacuum
filtration and contract hauling) are not included in the
compliance costs. It is assumed that it is economical for the
plant to practice recycle in this case, and therefore, the
related costs are considered to be process associated, or a cost
of doing business.
(3) Capital costs for flow reduction (via recycling) were
not included in the compliance costs whenever the plant
reported recycle to the stream, even it the specific method of
recycle was not reported.
(g) Settling lagoons were assumed to be equivalent to
vacuum filtration for dewatering treatment plant sludges.
Thus, whenever a plant reported settling lagoons to be
currently in use for treatment plant sludges, the capital costs
of vacuum filtration were not included. It was assumed that
annual vacuum filtration costs were comparable to those for
operation of settling lagoons and were thus retained.
COST ESTIMATES FOR INDIVIDUAL TREATMENT TECHNOLOGIES
Treatment technologies have been selected from among the larger
set of available alternatives discussed in Section VII after
considering such factors as raw waste characteristics, typical
plant characteristics (e.g., location, production schedules,
product mix, and land availability), and present treatment
practices. Specific rationale for selection is addressed in
Sections IX, X, XI, and XII of this document and the subcategory
supplements. Cost estimates for each technology addressed in
this section include investment costs and annual costs for
amortization, operation and maintenance, and energy.
The specific design and cost assumptions for each wastewater
treatment module are listed^under the subheadings to follow.
Costs are presented as a function of influent wastewater flow
except where noted in the unit process assumptions.
Costs are presented for the following control and treatment
technologies:
Cooling towers,
Flow equalization,
Cyanide precipitation and gravity settling,
Ammonia steam stripping.
Oil-water separation,
Chemical precipitation and gravity settling,
Sulfide precipitation and gravity settling,
Vacuum filtration,
Holding tanks,
Multimedia filtration,
Activated carbon adsorption,
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GENERAL DEVELOPMENT DOCUMENT
SECT - VIII
Chemical oxidation, and
Contract hauling.
In addition, costs for the following items associated with
compliance costs are also discussed:
Enclosures
Segregation
Cooling Towers
Cooling towers are used to reduce discharge flows by recycling
cooling water waste streams. Holding tanks are used to recycle
flows less than 3,400 liters per hour {15 gpm). This flow
represents the effective minimum cooling tower capacity generally
available.
The cooling tower capacity is based on the amount of heat
removed, which takes into account both the design flow and the
temperature decrease needed across the cooling tower. The
influent flow to the cooling tower and the recycle rate are based
on the assumptions given in Table VIII-9 (page 346). It should be
noted that for BAT a cooling tower is not included for cases in
which the actual flow is less than the reduced regulatory flow
(BAT flow) since flow reduction is not required. The recycle
ratios for waste streams undergoing flow reduction (based on
cooling tower technology) are discussed in Section X of the
pertinent subcategory supplement.
The temperature decrease is calculated as the difference between
the hot water (inlet) and cold water (outlet) temperatures. The
cold water temperature was assumed to be 29°C (85°F) and an
average value calculated from sampling data is used as the hot
water temperature for a particular waste stream. When such data
were unavailable, or resulted in a temperature less than 35°C
(95°F), a value of 35°C (95°F) was assumed, resulting in a
cooling requirement for a 6°C (10°F) temperature drop. The other
two design parameters, namely the wet bulb temperature (i.e.,
ambient temperature at 100 percent relative humidity) and the
approach (the difference between the outlet water temperature and
the wet bulb temperature), were assumed to be constant at
25°C (77°F) and 4°C (8°F), respectively.
For flow rates above 3,400 1/hr, a cooling tower is designed. The
cooling tower is sized by calculating the required capacity in
evaporative tons. Cost data were gathered for cooling towers up
to 700 evaporative tons.
The capital costs of cooling tower systems include the following
equipment:
Cooling tower (crossflow, mechanically-induced) and typical
accessor ies
Piping and valves (305 meters (1,000 ft.), carbon
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
steel)
Cold water storage tank (1-hour retention time)
Recirculation pump, centrifugal
Chemical treatment system (for pH, slime and corrosion
control)
For heat removal requirements exceeding 700 evaporative tons,
multiple cooling towers are designed.
The direct capital costs include purchased equipment cost,
delivery, and installation. Installation costs for cooling
towers are assumed to be 200 percent to the cooling tower cost
based on information supplied by vendors.
Direct annual costs include raw chemicals for water treatment and
fan energy requirements. Maintenance and operating labor was
assumed to be constant at 60 hours per year. The water treatment
chemical cost is based on a rate to $220/1,000 lph ($5/gpm) of
recirculated water.
For small recirculating flows (less than 15 gpm), holding tanks
were used for recycling cooling water. A holding tank system
consists of a steel tank, 61 meters (200 feet) piping, and a
recirculation pump. The capacity of the holding tank is based on
the cooling requirements of the water to be cooled. Calculation
of the tank volume is based on a surface area requirement of
0.025 m2/lph (60 ft2/gpm) to recirculated flow and constant
relative tank dimensions.
Capital costs for the holding tank system include purchased
equipment cost, delivery, and installation. The annual costs are
attributable to the operation of the pump only (i.e., annual
costs for tank and piping are assumed to be negligible).
Capital and annual costs for cooling towers and tanks are
presented in Figure VIII-4 (page 353).
Flow Equalization
Flow equalization is accomplished through steel equalization
tanks which are sized based on a retention time of 8 or 16 hours
and an excess capacity factor of 1.2. A retention time of 16
hours was assumed only when the equalization tank preceded a
chemical precipitation system with "low flow" mode, and the
operating hours were greater than or equal to 16 hours per day.
In this case, the additional retention time is required to hold
wastewater during batch treatment, since treatment is assumed to
require 16 hours and only one reaction tank is included in the
"low flow" batch mode. Cost data were available for steel
equalization tank up to a capacity of 1,893,000 liters (500,000
gallons); multiple units were required for volumes greater than
1,893,000 liters (500,000 gallons). Fiberglass tanks are used
296
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
for capacities below 24,000 gallons. The tanks are fitted with
agitators with a horsepower requirement of 0,006 kw/1,000 liters
{0.03 hp/1,000 gallons) of capacity to prevent sedimentation. An
effluent transfer pump is also included in the equalization
system. Cost curves for capital and annual costs are presented
in Figure VIII-5 (page 354), for equalization at 8 hours and 16
hours retention time. Figure VIII-5 presents cost curves for
capital and annual costs that are applicable to the following
list of subcategories: primary aluminum, secondary aluminum,
primary copper, secondary copper, primary lead, primary zinc,
primary tungsten, primary columbiurn-tantalum, secondary silver,
and secondary lead.
Cyanide Precipitation and Gravity Settling
Cyanide precipitation is a two-stage process to remove complexed
and uncomplexed cyanide as a precipitate. In the first step, the
wastewater is contacted with an excess of FeS04.7H2O at pH
9.0 to ensure that all cyanide is converted to the complexed
form:
FeS04 ' 7H20 + 6CN > Fe(CN)63~ + 7H20 + S042" + e-
The hexacyanoferrate is then routed to the second stage, where
additional FeS04*?H20 and acid are added. In this stage, the pH
is lowered to 4.0 or less, causing the precipitation of
Fe3(Fe(CN)5)2 (Turnbull1s blue) and its analogues:
3FeS04 * 7H20 + 2Fe(CN)63~ > Fe3(Fe{CN)6)2 + 21H20 + 3S042"
A chemical defoamer may be added prior to pH adjustment to
inhibit foaming, as carbon dioxide degassing may occur when the
pH is lowered.
The blue precipitate is settled and the overflow is discharged
for further treatment.
Since the complexation step adjusts the pH to 9, metal hydroxides
will precipitate. These hydroxides may either be settled and
removed at pH 9 or resolubilized at pH 4 in the final
precipitation step and removed later in a downstream chemical
precipitation unit. Advantages of removal of the metal
hydroxides include reduced acid requirements in the final
precipitation step, since the metals will resolubilize when the
pH is adjusted to 4. However, the hydroxide sludge may be
classified as hazardous due to the presence of cyanide. In
addition, the continuous mode of operation requires an additional
clarifier between the complexation and precipitation step. These
additional costs make the settling of metal hydroxides
economically unattractive in the continuous mode. However, the
batch mode requires no extra equipment. Consequently, metal
hydroxide sludge removal in this case is desirable before the
precipitation step. Therefore, the batch cyanide precipitation
step settles two sludges: metal hydroxide sludge (at pH 9) and
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
cyanide sludge (at pH 4),
Costs were estimated for both batch and continuous systems with
the operating mode selected on a least cost basis. The equipment
and assumptions used in each mode are detailed below.
Costs for the complexation step in the continuous mode are based
on the following:
(1) Ferrous sulfate feed system
ferrous sulfate steel
storage hoppers with dust collectors (largest hopper
size is 170 mg (6,000 ft3); 15 days storage)
enclosure for storage tanks
volumetric feeders (small installations)
mechanical weigh belt feeders (large installations)
dissolving tanks (5-minute detention time,
6 percent solution)
dual-head diaphragm metering pumps
instrumentation and controls
(2) Lime feed system
hydrated lime
feeder
slurry mix tank (5-minute retention time)
feed pump
instrumentation (pH control)
(3) H2SO4 feed system (used when influent pH is >9)
93 percent H2SO4 delivered in bulk or in drums
acid storage tank (15 days retention) when
delivered in bulk
metering pump (standby provided)
pipe and valves
instrumentation and controls
(4) Reaction tank and agitator (fiberglass, 60-minute
retention time, 20 percent excess capacity, agitator
mount, concrete slab)
(5) Effluent transfer pump
For the primary aluminum subcategory, the lime feed system was
replaced with a caustic feed system. This system consisted of
day tanks (2) with mixers and feeders for feed rates less than
200 lbs/day, a fiberglass tank with a 15-day storage capacity for
feed rates greater than 200 lbs/day, chemical metering pumps,
pipes and values, and instruments and controls.
Costs for the second step (precipitation) in the continuous mode
are based on the following equipment:
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
(1) FeS04 feed system - as above
(2) H2SO4 feed system - as above
(3) Polymer feed system
chemical mix tank with agitator
chemical metering pump
system storage hopper
(4) Reaction tank with agitator (fiberglass, 30-minute
retention time, 20 percent excess capacity, agitator
mount, concrete slab)
(5) Clarifier
sized based on 709 lph/m2 (17.4 gph/ft2), 3
percent solids in underflow
steel or concrete, above ground
support structure, sludge scraper, and other internals
center feed
(6) Effluent transfer pump
(7) Sludge transfer pump
A chemical defoaming system may be included. Defoaming costs
consist of the antifoam chemical and the chemical feed system.
Operation and maintenance costs for continuous mode cyanide pre-
cipitation include labor requirements to operate and maintain the
system, electric power for mixers, pumps, clarifier and controls,
and treatment chemicals. Electrical requirements are also
included for the chemical storage enclosures for lighting and
ventilation and in the case of caustic storage, heating. The
following assumptions are used in establishing OEM costs for the
complexation step in the continuous mode:
(1) Ferrous sulfate feed system
stoichiometry of 1 mole
FeS04 7H20 to 6 moles CN-
1.5 times stoichiometric dosage to
drive reaction to completion
operating labor at 10 min/feeder/shift
maintenance labor at 8 hr/yr for liquid metering
pumps
power based on agitators, metering pumps
maintenance materials at 3 percent of capital cost
chemical cost at $0.1268 per kg ($0.0575 per lb)
(2) Lime feed system
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
dosage based on pH and metals content to raise pH
to 9
operating and maintenance labor requirements are
based on 20 min/day; in addition, 8 hr/7,260 kg
(8 hr/16,000 lbs) are assumed for delivery of
hydrated lime
maintenance materials cost is estimated as 3
percent of the purchased equipment cost
chemical cost of lime is based on $0.0474/kg
($0.0215 per lb) for hydrated lime delivered in
bags
(3) Acid feed system (if required)
dosage based on pH and metals to bring pH to 9
labor unloading - 0.25 hr/drum acid
labor operation - 15 min/day
annual maintenance - 8 hrs
power (includes metering pump)
maintenance materials - 3 percent of capital
cost
chemical cost at $0,082 per kg ($0,037 per lb)
(4) Reaction tank with agitator
operating and maintenance labor at 120 hrs/yr
maintenance materials
— tank: 2 percent of tank capital cost
— pump: 5 percent of pump capital cost
For the primary aluminum subcategory
maintenance materials costs were estimated
at 5 percent of capital cost,
power based on agitator (70 percent efficiency)
at 0.099 kW/1,000 liters (0.5 hp/1,000 gallons)
of tank volume
(5) Pump
operating labor at 0.04 hr/operating day
maintenance labor at 0.005 hr/operating hour for
flow <22,700 liters per hour (100 gpm)
maintenance materials at 5 percent of capital
cost
power based on pump hp
For the primary aluminum subcategory, the lime feed system was
replaced by a caustic feed system. The costs for the caustic
feed system are as follows:
Caustic feed system
dosage based on pH and metals content to raise pH
to 9
maintenance materials - 3 percent of manufactured
equipment cost (excluding storage tank cost)
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
labor unloading
—dry NaOH - 8 hrs/16,000 lbs
—liquid 50 percent NaOH - 5 hrs/50, 000 lbs
labor operation (dry NaOH only) 10 min/day/feeder
labor operation for metering pump - 15 min/day
annual maintenance - 8 hrs
power [includes metering pump hp, instrumentation
and control, volumetric feeder (dry NaOH)]
chemical cost at §0.183 per lb
The following assumptions were used for the continuous mode
precipitation step:
(1) Ferrous sulfate feed system
stoichiometric dosage based on 3 moles
FeS04•7H2O to 2 moles of iron-complexed
cyanide (Fe (CN)6 )
total dosage is 10 times stoichiometric dosage
based on data from an Agency treatability study
other assumptions as above
(2) H2SO4 feed system
dosage based on pH adjustment to 4 and
resolubilization of the metal hydroxides
from the complexation step
other assumptions as above
(3) Polymer feed system
2 rag/1 dosage
operation labor at 134 hr/yr, maintenance labor at
32 hr/yr
maintenance materials at 3 percent of the capital
cost
energy at 17,300 kWh/yr
chemical cost at $4.96/kg (§2.25/lb)
(4) Reaction tank with agitator
see assumptions above
(5) Clarifier
sized based on 417 gpd/ft2, 3 percent solids
in underflow
maintenance materials range from 0.8 percent to
2 percent as a function of increasing size
labor - 150 to 500 hr/yr (depending on size)
power - based on horsepower requirements for
sludge pumping and sludge scraper drive unit
(6) Effluent transfer pump
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
see assumptions above
(7) Sludge pump
sized on underflow from clarifier
operation and maintenance labor varies with flow
rate
maintenance materials - varies from 7 percent to
10 percent of capital cost depending on flow rate
The batch mode cyanide precipitation step accomplishes both
complexation and precipitation in the same vessel. Costs for
batch mode cyanide complexation and precipitation are based on
the following equipment:
(1) Ferrous sulfate addition
from bags
added manually to reaction tank
(2) Lime addition
from bags
added manually to reaction tank
(3) H2SO4 addition
from 208 liter (55 gallon) drums
stainless steel valve to control flow
(4) Reaction tank and agitator (fiberglass, 8,5 hour
minimum retention time, 20 percent excess capacity,
agitator mount, concrete slab)
(5) Pump
effluent transfer pump
sludge pump
Operation and maintenance costs for batch mode cyanide
complexation and precipitation include costs for the labor
required to operate and maintain the equipment, electrical power
for agitators, pumps, and controls, and chemicals. The
assumptions used in estimating costs are as follows:
(1) Ferrous sulfate addition
stoichiometric dosage
—complexation: 1 mole FeS04•7H2O per 6 moles
CN-
—precipitation: 3 moles FeS04 7H2O per 2
moles of the iron cyanide complex (Fe(CNg )
actual dosage in excess of stoichiometric
complexation: 1.5 times stoichiometric dosage added
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
precipitation: 10 times stoichiometric dosage added
operating labor at 0.25 hr/batch
chemical cost at $0.1268/kg ($0.0575/lb)
no maintenance labor or materials or power costs
(2) Lime addition
dosage based on pH and metals content to raise pH
to 9
operating labor at 0.25 hr/batch
chemical cost at $0.0474/kg ($0.0215/lb)
no maintenance labor or materials or power costs
(3) H2SO4 addition
dosage based on pH and metals content to lower pH
to 9 (for complexation if required) and/or to lower
pH to 4 (for precipitation)
operating labor at 0.25 hr/batch
chemical cost at $0.082/kg ($0.037/lb)
no maintenance labor or materials or power costs
(4) Reaction tank with agitator
maintenance materials
—tank; 2 percent of tank capital cost
—pump; 5 percent of pump capital cost
power based on agitator (70 percent efficiency) at
0.099 kW/1,000 liters (0.5 hp/1,000 gallons) of tank
volume
(5) Pumps
effluent transfer pump
—operating labor at 0.04 hr/operating day
—maintenance labor at 0.005 hr/operating day (or
flows < 22,700 1/hr (100 gpm)
—maintenance materials at.5 percent of capital cost
—power based on pump hp
sludge pump
—operation and maintenance costs vary with flow
rate
—maintenance materials costs vary from 7 to 10 per-
cent of capital cost depending on flow rate
Capital and annual costs for continuous and batch mode cyanide
precipitation are presented in Figure VII1-6 (page 355). Figure
VIII-6 presents cost curves for capital and annual costs that are
applicable to the following list of subcategories; primary
aluminum, secondary aluminum, primary copper, secondary copper,
primary lead, primary zinc, primary tungsten, primary columbium-
tantalum, secondary silver, and secondary lead.
Ammonia Steam Stripping
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
Ammonia removal using steam is a proven technology that is in use
in many industries. Ammonia is more volatile than water and may
be removed using steam to raise the temperature and
preferentially evaporate the ammonia. This process is most
economically done in a plate or packed tower, where the
method of contacting the liquid and vapor phases reduces the
steam requirement.
The pH of the influent wastewater is raised to approximately 12
to convert almost all of the ammonia present to molecular ammonia
(NH3) by the addition of lime. The water is then preheated
before it is sent to the column. This process takes place by
indirectly contacting the influent with the column effluent and
with the gaseous product via heat exchangers. The water enters
the top of the column and travels downward. The steam is
injected at the bottom and rises through the column, contacting
the water in a countercurrent fashion. The source of the steam
may be either reboiled wastewater or another steam generation
system, such as the plant boiler system.
The presence of solids in the wastewater, both those present in
the influent and those which may be generated by adjusting the pH
(such as metal hydroxides), necessitates periodic cleaning of the
column. This requires an acid cleaning system and a surge tank
to hold wastewater while the column is being cleaned. The column
is assumed to require cleaning approximately once per week based
on the demonstrated long-term cleaning requirements of an ammonia
stripping facility. The volume of cleaning solution used per
cleaning operation is assumed to be equal to the total volume of
the empty column (i.e., without packing).
For the estimation of capital and annual costs, the following
pieces of equipment were included in the design of the steam
stripper:
(1) Packed tower
3-inch Rashig rings
hydraulic loading rate = 2 gpm/ft2
height equivalent to a theoretical plate = 3ft
(2) pH adjustment system
lime feed system (continuous) - see chemical
precipitation section for discussion
rapid mix tank, fiberglass (5-minute retention time)
agitator (velocity gradient is 300 ft/sec/ft)
control system
pump
(3) Heat exchangers (stainless steel)
(4) Reboiler (gas-tired)
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
(5) Acid cleaning system
batch tank, fiberglass
agitator (velocity gradient is 60/sec.)
metering pump
(6) Surge tank (8-hour retention time)
The direct capital cost to the lime feed system was based on the
chemical feed rate as noted in the discussion on chemical
precipitation. Sulfuric acid used in the acid cleaning system
was assumed to be added manually, requiring no special equipment.
Other equipment costs were direct or indirect functions of the
influent flow rate. Direct annual costs include operation and
maintenance labor for the lime feed system, heat exchangers and
reboiler, the cost of lime and sulfuric acid, maintenance
materials, energy costs required to run the agitators and pumps,
and natural gas costs to operate the reboiler. The total direct
capital and annual costs are presented in Figure VIII-7 (page
356).
Oil-Water Separation
Oil skimming costs apply to the removal of free (non-emulsified)
oil using either a coalescent plate oil-water separator or a belt
skimmer located on the equalization tank. The latter is
applicable to low oily waste flows (less than 189 liters per day)
whereas the coalescent plate separator is used for oily flows
greater than 189 liters/day (50 gpd).
Although the required coalescent plate separator capacity is
dependent on many factors, the sizing was based primarily on the
influent wastewater flow rate, with the following design values
assumed for the remaining parameters of importance:
Parameter Design Value
Specific gravity of oil 0.85
Operating temperature (°F) 68
Influent oil concentration (mg/1) 30,000
Effluent oil concentration (mg/1) 10.0
Extreme operating condi tions, such as influent oil concentrat ions
greater than 30,000 mg/1, or temperatures much lower than
20°C (68°F) were accounted for in the sizing of the separator.
Additional capacity for such extreme conditions was provided
using correlations developed from actual oil separator
performance data.
The capital and annual costs of oil-water separation include the
following equipment:
Coalescent plate separator with automatic shutoff
valve and level sensor
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
Oily waste storage tanks (2-week retention time)
Oily waste discharge pump
Effluent discharge pump
Influent flow rates up to 159,100 1/hr {700 gpm) are treated in a
single unit. Flows greater than this require multiple units.
The direct annual costs for oil-water separation include the cost
of operating and maintenance labor and replacement parts. Annual
costs for the coalescent plate separators alone are minimal and
involve only periodic cleaning and replacement of the plates.
If the amount of oil discharged is 189 liters/day (50 gpd) or
less, it is more economical to use a belt skimmer'rather than a
coalescent plate separator. This belt skimmer may be attached to
the equalization basin which is usually necessary to equilibrate
flow surges. The belt skimmer-equalization basin configuration
is assumed to achieve 10 mg/1 oil in the effluent.
The equipment included in the belt oil skimmer and associated
design parameters and assumptions are presented below.
1. Belt oil skimmer
12-inch width
6-foot length
2. Oily waste storage tank
2-week storage
fiberglass
Capital costs for belt skimmers were obtained from published
vendor quotes. Annual costs were estimated from the energy and
operation and maintenance requirements. Energy requirements are
calculated from the skimmer motor horsepower. Operating labor is
assumed constant at 26 hours per year. Maintenance labor is
assumed to require 24 labor hours per year and belt replacement
once a year. Cost curves for capital and annual costs of
oil-water separation are presented in Figure VIII-8 (page
357). Figure VIII-8 presents cost curves for capital and annual
costs that are applicable to the following list of subcategories:
primary aluminum, secondary aluminum, primary copper, secondary
copper, primary lead, primary zinc, primary tungsten, primary
columbium-tantalum, secondary silver, and secondary lead.
Chemical Precipitation and Gravity Settling
Chemical precipitation using lime or caustic followed by gravity
settling is a fundamental technology for metals removal. In
practice, quicklime (CaO), hydrated lime (Ca(OH)2), or caustic
(NaOH) can be used to precipitate toxic and other metals. Where
lime is selected, hydrated lime is generally more economical for
low lime requirements since the use of slakers, which are
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GENERAL DEVELOPMENT DOCUMENT
SECT
- VIII
necessary for quicklime usage, is practical only for large volume
applications of lime (greater than 50 Ibs/hr). The chemical
precipitant used for compliance cost estimation depends on a
variety of factors in the subcategory being considered. The
basis for the chemical precipitant (lime or caustic) used for a
particular subcategory may be found in the appropriate
supplement.
Lime or caustic is used to adjust the pH of the influent waste
stream to a value of approximately 9, at which optimum overall
precipitation of the metals as metal hydroxides is assumed to
occur. The chemical precipitant dosage is calculated as a
theoretical stoichiometric requirement based on the pH and the
influent metals concentrations. In addition, particular waste
streams may contain significant amounts of fluoride, such as
those found in the secondary tin and primary columbiurn-tantalum
subcategories. The fluoride will form calcium fluoride (CaF2)
when combined with free calcium ions which are present if lime is
used as the chemical precipitant. The additional sludge due to
calcium fluoride formation is included in the sludge generation
calculations. In cases where the calcium consumed by calcium
fluoride formation exceeds the calcium level resulting from
dosing for pH adjustment and metal hydroxide formation, the
additional lime needed to consume the remaining fluoride is
included in the total theoretical dosage calculation. The total
chemical dosage requirement is obtained by assuming an excess of
10 percent of the theoretical dosage. The effluent concentrations
are generally based on the Agency's combined metals data base
treatment effectiveness values for chemical precipitation
technology described in Section VII (see Table Vil-21, page 248).
The costs of chemical precipitation and gravity settling are
based on one of three operating modes, depending on the influent
flow: continuous, "normal" batch, or "low flow" batch. The use
of a particular mode for cost estimation purposes is determined
on a least cost (total annualized) basis. The economic break-
point between continuous and normal batch was estimated to be
10,600 1/hr (46.7 gpm). Below 2,200 1/hr, it was found that the
low flow batch was the most economical. The direct capital and
annual costs are presented in Figure VIII-9 (page 358 for all
three operating modes. Figure VIII-9 presents cost curves for
capital and annual costs that are applicable to the following
list of subcategories: primary aluminum, secondary aluminum,
primary copper, secondary copper, primary lead, primary zinc,
primary tungsten, primary columbium-tantalum, secondary silver,
and secondary lead.
Continuous Mode. For continuous operation, the following
equipment is included in the determination of capital and annual
costs:
(1) Chemical precipitant feed system (continuous)
1 ime
—bags (for hydrated lime) or storage units (30-day
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
storage capacity) for quicklime
—slurry mix tank (5-minute retention time) or
slaker
—feed pumps (for hydrated lime slurry) or gravity
feed (for quicklime slurry)
— instrumentation (pH control)
caustic
—day tanks (2) with mixers and feeders for feed
rates less than 200 lbs/day; fiberglass tank with
15-day storage capacity otherwise
—chemical metering pumps
—pipe and valves
—instrumentation (pH control)
(2) Polymer feed system
storage hopper
chemical mix tank with agitator
chemical metering pump
(3) Reaction system
rapid mix tank, fiberglass (5-minute retention time)
agitator (velocity gradient is 300 ft/sec/ft)
instrumentation and control
(4) Gravity settling system
clarifier, circular, steel (overflow rate of 360
gpd/ft. and underflow solids of 5 percent) were
used for most subcategories. However, for the
following subcategories, an overflow rate of
500 gpd/ft and an underflow solids of 3 percent
was used: primary aluminum, secondary aluminum,
primary copper, secondary copper, primary lead,
pr imary zinc, pr imary tungsten, primary
columbium-tantalum, secondary silver, and secondary
lead.
(5) Sludge pump
Ten percent of the clarifier underflow stream is recycled to the
pH adjustment tank to serve as seed material for the incoming
waste stream.
The direct capital costs of the chemical precipitant and polymer
feed are based on the respective feed rates (dry lbs/hr), which
are dependent on the influent waste stream characteristics. The
flexibility of this feature (i.e., costs are independent of other
module components) was previously noted in the description of the
cost estimation model. The remaining equipment costs (e.g., for
tanks, agitators, pumps) were developed as a function of the
influent flow (either directly or indirectly, when coupled with
the design assumptions).
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
Direct annual costs for the continuous system are based on the
following assumptions:
(1) Lime feed system
Operating and maintenance labor requirements are
based on 3 hrs/day for the quicklime feed system and
20 min/day for the hydrated lime feed system. In
addition, 5 hrs/50,000 lbs are required for bulk
delivery of quicklime and 8 hrs/16,000 lbs are
assumed for delivery of hydrated lime.
Maintenance materials cost is estimated as 3 percent
of the purchased equipment cost.
Chemical cost of lime is based on $47.40/kkg
($43.00/ton) for hydrated lime delivered in bags and
$34.50/kkg ($31.30/ton) for quicklime delivered on a
bulk basis. These costs were obtained from the
Chemical Weekly Reporter (March 1982).
(2) Caustic feed system
Labor for unloading of dry NaOH requires 8 hours per
16,000 lbs delivered. Liquid 50 percent NaOH
requires 5 hours per 50,000 lbs.
Operating labor for dry NaOH feeders is 10
min/day/feeder
Operating labor for metering pump is 15 min/day
Maintenance materials cost is assumed to be 3
percent of the purchased equipment cost.
Energy cost is based on the horsepower requirements
for the feed pumps and mixers. Energy requirements
generally represent less than 5 percent of the total
annual costs for the caustic feed system.
Chemical cost is $1,183 per lb.
(3) Polymer feed system
Polymer requirements are based on a dosage of 2
mg/1.
The operating labor is assumed to be 134 hrs/yr,
which includes delivery and solution preparation
requirements. Maintenance labor is estimated at 32
hrs/yr.
Energy costs for the feed pump and mixer are based
on 17,300 kw-hr/yr.
Chemical cost for polymer is based on $5.0Q/kkg
($2.225/lb).
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
(4) Reaction system
Operating and maintenance labor requirements are 120
hrs/yr.
Pumps are assumed to require 0.005 hrs of mainte-
nance/operating hr (for flows less than 100 gpm)
or 0.01 hrs/operating hr (flows greater than 100
gpm), in addition to 0.05 hrs/operating day for
pump operation.
Maintenance materials costs are estimated as 5
percent of the purchased equipment cost.
Energy costs are based on the power requirements for
the pump (function of flow) and agitator (0.06 hp/
1,000 gal). An agitator efficiency of 70 percent
was assumed.
(5) Gravity settling system
Annual operating and maintenance labor requirements
range from 150 hrs for the minimum size clarifier
(300 ft.2) to 500 hrs for a clarifier of 30,000
ft.2. In addition, labor hrs for operation and
maintenance of the sludge pumps were assumed to
range from 55 to 420 hrs/yr, depending on the pump
capacity (10 to 1,500 gpm).
Maintenance material costs are estimated as 3
percent of the purchased equipment cost.
Energy costs are based on power requirements for the
sludge pump and rake mechanism.
Normal Batch Mode. The normal batch treatment system, which is
used for flows between 2,200 and 10,600 1/hr, consists of the
following equipment:
(1) Chemical precipitant feed system
lime (batch)
—slurry tank (5-minute retention time)
—agitator
—feed pump
caustic (batch)
—fiberglass tank (1-week storage)
—chemical metering pump
(2) Polymer feed system
chemical mix tank
agitator
chemical metering pump
(3) Reaction system
reaction tanks (minimum of 2) (8-hour retention
time each)
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
agitators (2) (velocity gradient is 300 ft/sec/ft)
pH control system
The reaction tanks used for pH adjustment are sized to hold the
wastewater volume accumulated for one batch period (assumed to be
8 hours). The tanks are arranged in a parallel setup to allow
treatment in one tank while wastewater is accumulated in the
other tank. A separate gravity settler is not necessary since
settling can occur in the reaction tank after precipitation has
taken place. The settled sludge is then pumped to the dewatering
stage if necessary.
Direct annual costs for the batch treatment system are based on
the following assumptions:
(1) Lime feed system (batch)
Operating labor requirements range from 15 to 60
min/batch, depending on the feedrate (5 to 1,000 lbs
of hydrated lime/batch).
Maintenance labor is assumed to be constant at 52
hrs/yr (1 hr/week).
Energy costs for the agitator and feed pump are
assumed to be negligible.
Chemical costs are based on the use of hydrated lime
(see continuous feed system assumptions).
(2) Caustic feed system (batch)
Operating labor requirements are based on 30
min/metering pump/shift.
Maintenance labor requirements are 16 hrs/metering
pump/yr.
Energy costs are assumed to be negligible.
Chemical costs are based on the use of 50 percent
liquid caustic solution (see continuous feed
system).
(3) Polymer feed system (batch)
Polymer requirements are based on a dosage of
2 mg/1.
Operating and maintenance labor are ass-urned to
require 50 hrs/yr.
Chemical cost for polymer is based on $5.00/kkg
($2.25/lb).
(4) Reaction system
Required operating labor is assumed to be 1 hr/batch
(for pH control, sampling, valve operation, etc.)
Maintenance labor requirements are 52 hrs/yr.
Energy costs are based on power requirements for
operation of the sludge pump and agitators.
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Low-Flow Batch Mode. For small influent flows (less than 2,200
1/hr), it Is more economical on a total annualized cost basis to
select the "low flow" batch treatment system. The lower flows
allow an assumption of up to five days for the batch duration, or
holding time, as opposed to eight hours for the normal batch
system. However, whenever the total batch volume (based on a
five-day holding time) exceeds 10,000 gallons, which is the
maximum single batch tank capacity, the holding time is decreased
accordingly to maintain the batch volume under this level. The
cutoff value used for maximum single batch tank capacity for the
following list of subcategories was 25,000 gallons, rather than
10,000 gallons: primary aluminum, secondary aluminum, primary
copper, secondary copper, primary lead, primary zinc, primary
tungsten, primary columbium-tantalum, secondary silver and
secondary lead. Capital costs for the low flow system are based
on the following equipment:
(1) Reaction system
reaction/holding tank (5-day or less retention time)
agitator
transfer pump
(2) Polymer feed system (batch)
chemical mix tank (5-day retention time)
agitator
chemical metering pump
The polymer feed system is included for the low flow system for
manufacturing processes operating in excess of 16 hours per day.
The addition of polymer for plants operating 16 hours or less per
day is assumed to be unnecessary due to the additional settling
time available.
Only one tank is required for both equalization and treatment
sincje sedimentation is assumed to be accomplished during non-
production hours (since the holding time is greater than the time
required for treatment). Costs for a chemical precipitant feed
system are not included since lime or caustic addition at low
application rates can be assumed to be done manually by the
operator. A common pump is used for transfer of both the
supernatant and sludge through an appropriate valving
arrangement.
As in the normal batch case, annual costs consist mainly of labor
costs for the low flow system and are based on the following
assumptions:
(1) Reaction system
Operating labor is assumed to be'" constant at 1 hr/
batch (for pH control, sampling, filling, etc.).
For the primary aluminum, secondary aluminum,
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
primary copper, secondary copper, primary lead, primary
zinc, primary tungsten, primary columbium-tantalum,
secondary silver, and secondary lead subcategories
operating labor value of 2 hrs/batch is used.
Additional labor is also required for the manual
addition of lime or caustic, ranging from 15 minutes
to 1.5 hrs/batch depending on the feed requirement
(1 to 500 lbs/batch).
Maintenance labor is 52 hrs/yr (1 hr/wk).
Energy costs are based on power requirements
associated with the agitator and pump.
Chemical costs are based on the use of hydrated lime
or liquid caustic (50 percent).
(2) Polymer feed system {batch)
See assumptions for normal batch treatment.
The capital and annual costs for chemical precipitation are
presented in Figure VIII-9 (page 358), for all three operating
modes.
Sulfide Precipitation and Gravity Settling
Precipitation using sulfide followed by gravity settling is a
technology similar to lime precipitation. In general, sulfide
precipitation removes more metals from wastewater than lime
precipitation because metal sulfides are less soluble than metal
hydroxides. Another configuration using sulfide precipitation is
appropriate for removal of arsenic and selenium (as well as other
metals) in the metallurgical acid plant subcategory. That system
is discussed in Section VIII of the metallurgical acid plant
subcategory supplement.
Sulfide precipitants can be either soluble sulfides (such as
sodium sulfide, or sodium hydrosulfide) or insoluble sulfides
(such as ferrous sulfide). Soluble sulfides generate less sludge
than insoluble sulfides, are less expensive, and are more
commonly used in industry. As such, the sulfide precipitation
module is based on the use of sodium sulfide.
The sulfide precipitation system generally used for this category
consists of the use of sulfide precipitation as a polishing step
following chemical precipitation (described above). Sodium
sulfide is added to the wastewater. The sodium sulfide reacts
with the remaining dissolved metals to form metal sulfides. The
sodium sulfide concentration is calculated as the theoretical
stoichiometric requirement based on the influent metals
concentration. To calculate chemical requirements, the sodium
sulfide dosage is obtained by assuming an excess of 25 percent of
the theoretical sodium sulfide dosage. This 25 percent excess of
sodium sulfide is needed to ensure complete reaction to the metal
sulfides within the time allowed in the reaction tank. As noted
below, the sulfide dosage would actually be controlled in a plant
by a specific-ion electrode. Effluent concentrations are based
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on treatment effectiveness values for sulfide precipitation.
The reaction tank is equipped with a specific-ion electrode which
monitors the solution potential during the addition of sodium
sulfide. The sulfide ion reacts with the metals in solution to
form insoluble metal sulfides as discussed above. When all of
the metal is reacted, excess sulfide ion causes a sharp negative
potential change, which automatically stops the sulfide addition
at the correct point. This control equipment helps to eliminate
the release of H2S gas from the reaction tank. A ventilation
hood is included in the cost estimate to control any H2S which
would be released. As a final protection, an aeration system is
included to remove any excess sulfide prior to discharge.
As with lime precipitation costs, the costs for sulfide precipi-
tation, and gravity settling are based on one of three operation
modes, depending on the influent flow rate: continuous, normal
batch, and low flow batch. The use of a particular mode for cost
estimation purposes was determined on a least cost (total
annualized) basis for a given flow rate. The economic breakpoint
between continuous and normal batch is assumed to be 10,600
liters/hour. Below 2,200 liters/hour, it is assumed that the low
flow batch system is most economical. Although all three modes
of operation were available for cost estimations for the
category, the flow rates for all plants requiring sulfide
precipitation were in the continuous range of operation. Since
only the continuous mode was used, the normal batch and low flow
batch operation modes are not included in the following
discussion.
For a continuous operation, the following equipment were included
in the determination of the capital and annual costs:
(1) Sodium sulfide feed system (continuous)
storage units (sized for 15-day storage)
mix tank (5-minute retention time)
feed pumps
hood for ventilation
(2) Polymer feed system
storage hopper
chemical mix tank with agitator
chemical metering pump
(3) pH adjustment system
rapid mix tank, fiberglass
agitator (velocity gradient is 300 ft/sec/ft)
control system
(4) Sulfide precipitation system
rapid mix tank, fiberglass
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
agitator (velocity gradient is 300 ft/sec/ft)
hood for ventilation
a specific-ion electrode
(5) Flocculation system
slow mix tank, fiberglass
agitator (velocity gradient is 100 ft/sec/ft)
2.0 mg/1 polymer dosage
(6) Gravity settling system
clarifier, circular, steel (overflow rate is 500
gpd/ft , underflow is 3 percent solids)
sludge pump (1)
Lime is added to adjust pH as necessary. Lime costs are included
in the subcategory supplements where appropriate. An aeration
system (tank and spargers) for removing excess hydrogen sulfide
is also included in the costs.
The direct capital costs of the lime, sodium sulfide, and polymer
feed systems were based on the respective chemical feed rates
(dry lbs/hour), which are dependent on the influent waste stream
characteristics. Direct annual costs for the continuous system
include operating and maintenance labor for the feed systems and
the clarifier, the cost of lime, sodium sulfide, and polymer,
maintenance materials and energy costs required to run the
agitators and pumps. The assumptions for each of these are
similar to those used for lime precipitation. Cost curves are
presented in Figure VIII-10 (page 359), page for capital and
annual costs of the continuous system. Figure VIII-10 presents
cost curves for capital and annual costs that are applicable to
the following list of subcategories: primary aluminum, secondary
aluminum, primary copper, secondary copper, primary lead, primary
zinc, primary tungsten, primary columbium-tantalum, secondary
silver, and secondary lead.
Vacuum Filtration
The underflow from the clarifier at 3 percent solids is routed to
a rotary precoat vacuum filter, which dewaters sludge to a cake
of 20 percent dry solids. The dewatered sludge is disposed of by
contract hauling and the filtrate is recycled to the chemical
precipitation step.
The capacity of the vacuum filter, expressed as square feet of
filtration area, is based on a yield of 14.6 kg of dry solids/hr
per square meter of filter area (3 lbs/hr/ft2), a solids capture
of 95 percent and an excess capacity of 30 percent. It was
assumed that the filter operates eight hours/operating day.
Cost data were compiled for vacuum filters ranging from 0.9 to
69.7 m (9.4 to 750 ft) of filter surface area. Based on a total
annualized cost comparison, it was assumed that it was more
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
economical to directly contract haul clarifier underflow streams
which were less than 50 1/hr (0.23 gpm), rather than dewater by
vacuum filtration before hauling. For the following list of
subcategories, a flow cutoff value of 42 1/hr (0.19 gpm) was
used: primary aluminum, secondary aluminum, primary copper,
secondary copper, primary lead, primary zinc, primary tungsten,
primary columbiurn-tantalum, secondary silver, and secondary lead.
The costs for the vacuum filtration system include the following
equipment:
(1) Vacuum filter with precoat but no sludge conditioning
(2) Housing
(3) Influent transfer pump
{4) Slurry holding tank
(5) Sludge pumps
The vacuum filter is sized based on 8 hrs/day operation. The
slurry holding tank and pump are excluded when the treatment
system operates 8 hrs/day or less. It was assumed in this case
that the underflow from the clarifier directly enters the vacuum
filter and that holding time volume for the slurry in addition to
the clarifier holding time was unnecessary. For cases where the
treatment system is operated for more than 8 hrs/day, the under-
flow is stored during vacuum filter non-operating hours. The
filter is sized accordingly to filter the stored slurry in an 8
hour period each day. The holding tank capacity is based on the
difference between the plant and vacuum filter operating hours
plus an excess capacity of 20 percent. Cost curves for direct
capital and annual costs are presented in Figure VIII-11 (page
360), for vacuum filtration. Figure VIII-11 presents cost curves
for capital and annual costs that are applicable to the following
list of subcategories: primary aluminum, secondary aluminum,
primary copper, secondary copper, primary lead, primary zinc,
primary tungsten, primary columbium-tantalum, secondary silver,
and secondary lead.
The following assumptions were made for developing capital and
annual costs:
(1) Annual costs associated with the vacuum filter were
developed based on continuous operation (24 hrs/day!
365 days/yr). These costs were adjusted for a plant s
individual operating schedule by assuming that annual
costs are proportional to the hours the vacuum filter
actually operates. Thus, annual costs were adjusted by
the ratio of actual vacuum filter operating hours per
year (8 hrs/day x no. days/yr) to the number of hours
in continuous operation (8,760 hrs/yr).
(2) Annual vacuum filter costs include operating and
maintenance labor (ranging from 200 to 3,000 hrs/yr as
a function of filter size), maintenance materials
(generally less than five percent of capital cost), and
energy requirements (mainly for the vacuum pumps).
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
(3) Enclosure costs for vacuum filtration were based on
applying rates of $45/ft2 and $5/ft /yr for capital and
annual costs, respectively to the estimated floor area
required by the vacuum filter system. The capital cost
rate for enclosure is the standard value as discussed
below in the costs for enclosures discussion. The
annual cost rate accounts for electrical energy
requirements for the filter housing. Floor area for
the enclosure is based on equipment dimensions reported
in vendor literature, ranging from 300 ft2 for the
minimum size filter (9.4 ft) to 1,400 ft for a vacuum
filtration capacity of 1,320 ft2.
Holding Tanks-Recycle
A holding tank may be used to recycle water back to a process or
for miscellaneous purposes, e.g., storage for hose washdown for
plant equipment. Holding tanks are usually implemented when the
recycled water need not be cooled. The equipment used to deter-
mine capital costs are a fiberglass tank, pump, and recycle
piping. Annual costs are associated only with the pump. The
capital cost of a fiberglass tank is estimated on the basis of
required tank volume. Required tank volume is calculated on the
basis of influent flow rate, 20 percent excess capacity, and four
hour retention time. The influent flow and the degree of recycle
were derived from the assumptions outlined in Table VIII-9,
Cost curves for direct capital and annual costs are presented in
Figure VIII-12 (page 361).
Multimedia Filtration
Multimedia filtration is used as a wastewater treatment polishing
device to remove suspended solids not removed in previous
treatment processes. The filter beds consist of graded layers of
coarse anthracite coal and fine sand. The equipment used to
determine capital and annual costs are as follows:
(1) Gravity flow, vertical steel cylindrical filters with media
(anthracite and sand)
(2) Influent storage tank sized for one backwash volume
(3) Backwash tank sized for one backwash volume
(4) Backwash pump to provide necessary flow and head for
backwash operations including an air scour system
(5) Influent transfer pump including piping, valves, and a
control system
The hydraulic loading rate is 7,335 lph/m2 (180 gph/ft2) and the
backwash loading race is 29,340 lph/m2 (720 gph/ft2). The filter
is backwashed once per 24 hours for 10 minutes. The backwash
volume is provided from the stored filtrate.
Effluent pollutant concentrations are based on the Agency's
combined metals data base for treatability of pollutants by
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
filtration technology.
Cartridge-type filters are used instead of multimedia filters to
treat small flows (less than 800 liters/hour) since they are more
economical than multimedia filters at these flows (based on a
least total annualized cost comparison). The effluent quality
achieved by these filters was equivalent to the level attained by
multimedia filters. The equipment used to determine capital and
annual costs for membrane filtration are as follows:
(1) influent holding tank sized for eight hours retention
(2) pump
(3) prefilter
—prefilter cartridges
—prefilter housings
(g) membrane filter
—membrane filter cartridges
—housing
The majority of annual cost is attributable to replacement of the
spent prefilter and membrane filter cartridges. The maximum
loading for the prefilter and membrane filter cartridges was
assumed to be 0.225 kg per 0.254 meter length of cartridge. The
annual energy and maintenance costs associated with the pump are
also included in the total annual costs. Cost curves for direct
capital and annual costs are presented in Figure VIII-13 (page
362) for cartridge and multimedia filtration.
Activated Carbon Adsorption
Activated carbon is used to remove dissolved organic contaminants
from wastewater. As the wastewater is pumped through the carbon
column, organic contaminants diffuse into the carbon particles
through pores and are adsorbed onto the pore walls. As organic
material accumulates, the carbon loses its effectiveness and must
be replaced or regenerated periodically.
Two downflow carbon columns in series are used. The leading
column loses its effectiveness first, since most of the organics
are adsorbed in it. When breakthrough occurs (i.e., when the
column effluent concentration of a specified organic exceeds a
specified maximum), the column is taken off-line and the second
column becomes the leading column. When the carbon in the first
column is regenerated or replaced, it becomes the following
column. This configuration, known as a merry-go-round, results in
a more consistent effluent quality than a single, larger column
or a system where one column is active and one on standby.
During column operation, solids accumulate in the interstices of
the carbon bed. To prevent the column from plugging, the bed
must be periodically backwashed to remove these solids. Also, a
method for replacing spent carbon is required. Either
replacement with virgin carbon and disposal of the spent carbon
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or regeneration of the spent carbon via off-site or on-site
regeneration may be used.
The following pieces of equipment were included in the
determination of capital and annual costs:
(1) Carbon adsorption system
adsorption columns (2), downflow, merry-go-round
configuration
—hydraulic loading of 2.5 gpm/ft
initial carbon charge
pump
(2) Backwash facilities
backwash hold tank - to provide 15 gpm/ft2 per
column for 15 min.
pump
(3) Influent surge tank (1-hour retention time)
(4) Carbon replacement/regeneration facilities
replacement
off-site regeneration
on-site regeneration
The direct capital costs for the adsorption system pump, backwash
facilities, and surge tank are direct or indirect functions of
the influent flow rate. Direct capital costs for the adsorption
columns and replacement or regeneration facilities are functions
of the influent flow rate and the rate at which carbon is used,
or the carbon exhaustion rate. The rate (expressed in kg/1 or
lbs/ 1,000 gal) used depended upon the data available for the
types of organic contaminants being adsorbed. Carbon adsorption
data for a specific type of wastewater were preferred when
available; otherwise, isotherm data for selected organics were
used with conservative design factors. The specific exhaustion
rates selected are provided in the subcategory supplements.
The direct annual costs for the adsorption columns, backwash
facilities, and surge tank included operation and maintenance
labor for the columns and backwash facilities, maintenance
materials, and energy costs for pumping.
The carbon usage rate (kg carbon exhausted/hr) is a function of
the influent flow rate combined with the carbon exhaustion rate
expressed as a carbon usage rate (lbs carbon exhausted/hr). One
of three operating regimes is chosen on a least cost (total
annualized) basis for a given carbon usage rate. Below a usage
rate of about 1.6 lbs/hr, replacement of spent carbon with virgin
carbon and disposal of the spent carbon as a hazardous waste was
found to be most economical. Between 1.6 and 53 lbs/hr,
regeneration by an off-site regeneration service is more cost
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GENERAL DEVELOPMENT DOCUMENT SECT - VIII
effective. Oil-site regeneration facilities are more economical
above 53 lbs/hr.
For the carbon replacement option, no additional capital
investment is required. Direct annual costs consist of contract
hauling the spent carbon as a hazardous waste and the purchase
and installation of virgin carbon.
Direct capital costs for the off-site regeneration option include
hoppers for dewatering and storage of spent carbon. Also
included is the cost of acquiring an increased carbon inventory
where the actual required inventory is less than the minimum for
economical off-site regeneration (about 20,000 lbs). Direct
annual costs include the charge for regeneration, transportation
of the carbon to and from the regeneration facility, and costs
for placing carbon into the column.
Direct capital costs for an on-site regeneration facility include
costs for a multiple hearth furnace and associated equipment,
spent carbon storage, exhaust gas scrubbers, a carbon slurry
system, quench tank, housing, and controls and instrumentation.
Direct annual costs include operation and maintenance labor for
the regeneration facility, maintenance materials, and electricity
and natural gas costs for the building, electrical equipment, and
furnace. Also included is the cost of replacing carbon lost in
the regeneration process (10 percent of the spent carbon passing
through the furnace) with virgin carbon.
The total direct capital and annual costs for the activated
carbon adsorption system are presented in Figure Vlll-14 (page
363). Figure VII1-14 presents cost curves for capital and annual
costs that are applicable to the following list of subcategories:
primary aluminum, secondary aluminum, primary copper, secondary
copper, primary lead, primary zinc, primary tungsten, primary
columbium-tantalum, secondary silver, and secondary lead.
Chemical Oxidation
Chemical oxidation using ozone is an alternative technology to
activated carbon adsorption in the bauxite refining subcategory
for removing dissolved organics from the red mud impoundment net
precipitation discharges. Compliance costs for the bauxite
subcategory were based on activated carbon adsorption since it
was more cost-effective than chemical oxidation based on a total
annualized cost comparison. Chemical oxidation with ozone proved
to be uneconomical due to the capital intensive ozone generation
equipment required for the relatively high ozone consumption
rates encountered.
Ozone and hydrogen peroxide are considered as chemical oxidants
because they do not result in the release of secondary
pollutants, such as manganese or residual chlorine. Given the
high pH of the red mud impoundment net precipitation discharge
(11.5), ozone was selected over hydrogen peroxide because the
peroxide reaction occurs optimally at a pH of 4 or less, whereas
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ozone only requires neutralization to a pH of 7. An ozone dosage
level of 50 mg/1 was assumed for the particular organics and COD
loadings found in the red mud impoundment waste stream.
Neutralization of the waste stream to a pH of 7 with lime prior
to contact with ozone was accounted for in developing costs.
The costs for chemical oxidation with ozone were based on the
following equipment:
(1) Ozone generator
ozone preparation and dissolution equipment
electrical and instrumentation
safety and monitoring equipment
(2) Contact chamber, concrete (90 minute contact time)
(3) Neutralization system
mixing tank
— pump
agitator
Annual costs comprise mainly the labor and electricity costs
required to operate the ozone generation equipment and operation
and maintenance cost of the neutralization system.
Contract Hauling
Concentrated sludge and waste oils are removed on a contract
basis for off-site disposal. The cost of contract hauling
depends on the classification of the waste as being either
hazardous or nonhazardous. For nonhazardous wastes, a rate of
$0.106/liter ($0.40/galIon) was used in determining contract
hauling costs. The cost for contract hauling hazardous wastes
was developed from a survey of waste disposal services and varies
with the amount of waste hauled. No capital costs are associated
with contract hauling. Annual cost curves for contract hauling
nonhazardous and hazardous wastes are presented in Figure VIIl-
ls (page 364) .
Enclosures
The costs of enclosures for equipment considered to require
protection from inclement weather were accounted for separately
from the module costs (except for vacuum filtration). In
particular, chemical feed systems were generally assumed to
require enclosure.
Costs for enclosures were obtained by first estimating the
required enclosure area and then multiplying this value by the
unit cost in dollars per unit area. A capital cost of $485/m2
($45/ft2) was estimated, based on the following:
structure (including roofing, materials, insulation,
etc. )
site work (masonry, installation, etc.)
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SECT - VIII
electrical and plumbing
The rate for annual costs of enclosures is $54/m2 ($5/ft2) which
accounts for energy requirements for heating and lighting the
enclosure.
The required enclosure area is determined as the amount to total
required enclosure area which exceeds the enclosure area
estimated to be available at a particular plant. It was assumed
that a common structure could be used to enclose all equipment
needing housing unless information was available to indicate that
separate enclosures are needed (e.g., due to plant layout). The
individual areas are estimated from equipment dimensions reported
by vendors and appropriate excess factors. The available
enclosure areas were assumed as a function of plant site, based
on experience from site visits at numerous plants.
Segregation
Costs for segregation of wastewaters not included in this
regulation (e.g., noncontact cooling water) or for routing
regulated waste streams not currently treated to the treatment
system were included in the compliance cost estimates. The
capital costs for segregating the above streams were determined
using a rate of $6,900 for each stream requiring segregation.
This rate is based on the purchase and installation of 50 feet of
10 cm (4-inch) piping (with valves, pipe racks, and elbows) for
each stream. Annual costs associated with segregation are
assumed to be negligible.
Where a common stormwater-process wastewater piping system was
used at a plant, costs were included for both segregation of each
process waste stream to treatment (based on the above rate) and
segregation of stormwater for rerouting around the treatment
system.
Stormwater segregation cost is $8,800 based on the underground
installation of 305 m (300 feet) of 0.61 m (24-inch) diameter
concrete pipe.
COMPLIANCE COST ESTIMATION
To calculate the compliance cost estimates, the model was run
using input data as described previously. A cost summary is
prepared for each plant. An example of this summary may be found
in Table VIII-10 (page 347). Referring to this table, four types
of data are included for each option: run number, total capital
costs, required capital costs, and annual costs. Run number
refers to the computer run from which the costs were derived.
Total capital costs include the capital cost estimate for each
piece of wastewater treatment equipment necessary to meet mass
limitations. Required capital costs are determined by
considering the equipment and wastewater treatment system a plant
currently has in place. As discussed previously, the required
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capital costs reflect the estimates of the actual capital cost
the facility will incur to purchase and install the necessary
treatment equipment by accounting for what that facility already
has installed. Adequate operation and size of equipment currently
at a facility must be demonstrated before equipment is considered
to be in place. This prevents compliance cost underestimation.
Annual costs are based on all equipment in the treatment system,
as discussed previously.
NONWATER QUALITY ASPECTS
The elimination or reduction of one form of pollution may
aggravate other envi ronmental problems. Therefore, Sections
304(b) and 306 of the Act require EPA to consider the nonwater
quality environmental impacts (including energy requirements) of
certain regulations. In compliance with these provisions, EPA
has considered the effect of this regulation on air pollution,
solid waste generation, water scarcity, and energy consumption.
This regulation was circulated to and reviewed by EPA personnel
responsible for nonwater quality environmental programs. While
it is difficult to balance pollution problems against each other
and against energy utilization, the Administrator has determined
that the impacts identified below are justified by the benefits
associated with compliance with the limitations and standards.
The following are the nonwater quality environmental impacts
associated with compliance with BPT, BAT, NSPS, PSES, and PSNS.
Air Pollution, Radiation, and Noise
In general, none of the wastewater treatment or control processes
causes air pollution. Steam stripping of ammonia has a potential
to generate atmospheric emissions, however, with proper design
and operation, air pollution impacts are prevented. Air strip-
ping to ammonia also has a potential to generate atmospheric
emissions, because air stripping transfers ammonia from a water
to an air medium. Because air stripping was only considered as a
technology option for plants which presently use air stripping,
the Agency does not believe it will create an air quality
problem. Sulfide precipitation operations can involve hydrogen
sulfide vapors if not properly controlled. EPA's design for
sulfide precipitation includes an automatic pH-controller
equipped with a specific-ion electrode that monitors solution
potential during sulfide addition. When all to the available
metal ions are sequestered by the sulfide, the excess sulfide ion
causes a sharp negative potential change, automatically stopping
the sulfide addition. None of the wastewater treatment processes
cause objectionable noise or have any potential for radiation
hazards.
Solid Waste Disposal
As shown in the subcategory supplements, the waste streams being
discharged contain large quantities of toxic and other metals:
the most common method to removing the metals is by chemical
precipitation. Consequently, significant volumes of heavy
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SECT - VIII
metal laden sludge are generated that must be disposed of
properly.
The technologies that directly generate sludge are;
1. Cyanide precipitation
2. Chemical precipitation (lime, caustic, sulfide, iron
co-precipitation, etc.)
3. Multimedia filtration
4. Oil-water separation
Spent carbon from activated carbon adsorption also represents a
solid waste stream requiring disposal. The sludge volumes
generated by plants complying with these effluent limitations and
standards are estimated for each subcategory in Table VIII-12
(page 348).
The estimated sludge volumes generated from wastewater treatment
were obtained from material balances performed by the computer
model during cost estimation. The sludges resulting from the
technologies listed above will vary in characteristics depending
on the subcategory and combination of streams being treated. The
majority of sludge produced will be either dewatered sludge from
filtration or sludge from chemical precipitation.
A major concern in the disposal of sludges is the contamination
of soils, plants, and animals by the heavy metals contained in
the sludge. The leaching of heavy metals from sludge and
subsequent movement through soils is enhanced by acidic
conditions. Sludges formed by chemical precipitation possess high
pH values and thus are more resistant to acid leaching. Since
the largest amount of sludge that results from the alternatives
is generated by chemical precipitation, it is not expected that
metals will be readily leached from the sludge. Disposal of
sludges in a lined sanitary landfill will further reduce the
possibility of heavy metals contamination of soil, plants, and
animals.
Other methods of treating and disposing sludge are available. One
method currently being used at a number of plants is reuse or
recycle, usually to recover metals. Since the metal
concentrations in some sludges may be substantial, it may be cost
effective for some plants to recover the metal fraction of their
sludges prior to disposal.
The Solid Waste Disposal Act Amendments of 1980 prohibited EPA
from regulating certain wastes under Subtitle C of RCRA until
completion of certain studies and certain rulemaking. Among these
wastes are "solid waste from the extraction, beneficiation and
processing of ores and minerals." EPA has therefore exempted
from hazardous waste status any solid wastes from primary
smelting and refining, as well as from exploration, mining, and
324
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VIII
in 1111 ng.
The Agency has not made a determination of the hazardous
character of sludges and solid wastes generated from the
secondary metals processing plants covered by this regulation.
Each sludge generator in the secondary metals subcategories is
subject to the RCRA tests for ignitability, corrosivity,
reactivity, and toxicity. Costs for treatment and disposal of
such sludges and solid wastes, as well as nonhazardous sludges
and solid wastes, have been presented in this section.
Wastewater treatment sludges from this category are expected to
be non-hazardous by the E,P. Toxicity test under RCRA when
generated using the model technology. The only sludges expected
to be hazardous under RCRA, generated as a result of wastewater
treatment, are those from sulfide or cyanide precipitation steps.
The Agency has included costs for disposal of those hazardous
sludges in its estimates of compliance costs. Treatment of
similar wastewaters from other categories using this technology
has resulted in non-hazardous sludges. Costs for disposal of
non-hazardous wastes are included in the annual costs.
Consumptive Water Loss
Treatment and control technologies that require extensive
recycling and reuse of water may require cooling mechanisms.
Evaporative cooling mechanisms can cause water loss and
contribute to water scarcity problems, a primary concern in arid
and semi-arid regions. While this regulation assumes water
reuse, the overall amount of reuse through evaporative cooling
mechanisms is low and the quantity of water involved is not
significant. The Agency has concluded that consumptive water
loss is insignificant and that the pollution reduction benefits
of recycle technologies outweigh their impact on consumptive
water loss.
Energy Requirements
The incremental energy requirements of a wastewater treatment
system have been determined in order to consider the impact of
this regulation on natural resource depletion and on various
national economic factors associated with energy consumption. The
calculation of energy requirements for wastewater treatment
facilities proceeded in two steps. First, the portion of
operating costs which were attributable to energy requirements
was estimated for each wastewater treatment module. Then, these
fractions, or energy factors, were applied to each module in all
plants to obtain the energy costs associated with wastewater
treatment for each plant. These costs were summed for each
subcategory and converted to kW-hrs using the electricity charge
rate previously mentioned ($0.0483/kW-hr for March 1982). The
total plant energy usage was calculated based on the data
collection portfolios.
Table VI11-12 (page 349), presents these energy requirements for
325
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VIII
each regulatory option on each subcategory. From the data in
this table, the Agency has concluded that the energy requirements
of the proposed treatment options will not significantly affect
the natural resource base nor energy distribution or consumption
in communities where plants are located.
326
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VIII
Table VI-I-1
BPT COSTS OF COMPLIANCE FOR THE
NONFERROUS METALS MANUFACTURING CATEGORY
Final Regulation Cost
Estimates (§1982)
Subcategory
Capital
Annual
Primary Lead
242,000
112,000
Primary Tungsten
619,000
1,008,000
Primary Columbium-Tantalum
680,000
1,139,000
Secondary Silver
110,000
309,000
Secondary Lead
1,631,000
1,124,000
Primary Antimony
196,400
554,200
Primary Beryllium
226,500
211,200
Primary and Secondary
B
B
Germanium and Gallium
Primary Molybdenum and Rhenium
B
B
Metallurgical Acid Plants
B
B
(associated with molybdenum
roasters)
Secondary Molybdenum and
B
B
Vanadium
Primary Nickel and Cobalt
B
B
Primary Precious Metals and
2,200
26,800
Mercury
Secondary Precious Metals
B
B
Primary Rare Earth Metals
A
28,700
Secondary Tantalum
B
B
Secondary Tin
841,300
692,600
Primary and Secondary Titanium
644,500
505,300
Secondary Tungsten and Cobalt
B
B
Secondary Uranium
54,800
90,400
Primary Zirconium and Hafnium
B
B
NOTES: A = no incremental costs
B = based on confidential data
*Costs are shown for the selected option only.
327
-------
GENERAL DEVELOPMENT DOCUMENT
SECT - VIII
Table VIII-2
BAT COSTS OF COMPLIANCE FOR THE
NONFERROUS METALS MANUFACTURING CATEGORY
Subcategory
Primary Lead
Primary Tungsten
Primary Columbium-Tantalum
Secondary Silver
Secondary Lead
Primary Antimony
Bauxite Refining
Primary Beryllium
Primary and Secondary
Germanium and Gallium
Primary Molybdenum and Rhenium
Metallurgical Acid Plants
(associated with molybdenum
roasters)
Secondary Molybdenum and
Vanadium
Primary Nickel and Cobalt
Primary Precious Metals and
Mercury
Secondary Precious Metals
Primary Rare Earth Metals
Secondary Tantalum
Secondary Tin
Primary and Secondary Titanium
Secondary Tungsten and Cobalt
Secondary Uranium
Primary Zirconium and Hafnium
NOTES: A = no incremental costs
B = based on confidential
*Costs are shown for the selected
Promulgated
Regulation Cost
Number of Estimates ($1982)*
Dischargers Capital Annual
242,000 112,000
619,000 1,008,000
680,000 1,139,000
110,000 309,000
1,631,000 1,124,000
1 196,400 554,200
3 A B
1 226,500 211,200
0 B B
2 B B
2 B B
1 B B
1 B B
1 3,025 27,300
4 B B
1 B B
3 B B
3 B B
4 1,030,000 585,000
4 B B
1 88,000 106,700
1 B B
data
option only.
328
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VIII
Table VIII-3
PSES COSTS OF COMPLIANCE FOR THE
NONFERROUS METALS MANUFACTURING CATEGORY
Subcategory
Primary and Secondary
Germanium and Gallium
Secondary Indium
Secondary Nickel
Secondary Precious Metals
Primary Rare Earth Metals
Secondary Tin
Primary and Secondary Titanium
Secondary Tungsten and Cobalt
Number
of Indirect
Dischargers
.p.-- -I. • ,m in .—
1
1
30
1
2
2
1
Promulgated
Regulation Cost
Estimates ($1982)*
Capital Annual
B B
17,300 25,400
320,000 161,200
1,734,300 1,059,400
B B
160,200 50,000
B B
16,300 8,800
NOTES: B = based on confidential information
*Costs are shown for the selected option only,
329
-------
Table VIII-4
Equipment
Aerator for Sulfide
Precipitation
£ Agitator, C-clamp
o
Agitator, Top Entry
NONFERROUS METALS MANUFACTURING PHASE II CATEGORY
COST EQUATIONS FOR RECOMMENDED TREATMENT
AND CONTROL TECHNOLOGIES
Equat ion
C = 207.046 + 0.974477 (X)
- 1.58743 x 10-5 (X)2
A - -1 .536 + 0.504294 (X)
-8.15566 x 10-7 (X)2
C = 839.1 + 587.5 (HP)
A - 0.0483 x 0.746 (HP) + 0.05 (C)
C = 1,585.55 + 125.302 (HP) - 3.27437 (HP)2
A = 0.0483 x 0.746 (HP) + 0.05 (C)
Range of Validity
100< X < 25,000
0.25 < HP < 0.33
0.33 < HP < 5.0
M
52
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F
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2
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%
D
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cj
2
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«
Clarifier, Concrete
Clarifier Steel
C = 78,400 + 32.65 (S) - 7.5357 x 10-4(S)2
A - exp[8.22809 - 0.224781 (InS)
+ 0.0563252 (lnS)2]
C = 41,197. 1 + 72.0979 (S) + 0.0106542 (S)2
A = exp[8.22809 - 0.224781 (InS)
+ 0.0563252 (lnS)2]
500 < S < 12,000
300 < S < 2,800
w
w
o
i-i
<
H
M
M
-------
Table VIII-4 (Continued)
U>
u>
NONFERROUS METALS MANUFACTURING PHASE II CATEGORY
COST EQUATIONS FOR RECOMMENDED TREATMENT
AND CONTROL TECHNOLOGIES
Equipment
Cooling Tower System
Contract Hauling
Equation
exp[8.76408 + 0.07048 (InCTON)
+ 0.05095 (InCTON)2 J
exp[9.08702 + 0.75544 (InCTON)
+ 0.140379 (InCTON)2]
C = 0
A - 0.40 (G)(HPY)
C = 0
A = exp[-0.0240857 + 1.02731 (InG)
- 0.0196787 (InG)2](HPY)
Range of Validity
5 < CTON < 700
5 < CTON < 700
Non Hazardous
o
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25
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3
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%
H
O
O
o
C
2
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a
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Hazardous
Equalization Basin
14,759.8 + 0.170817 (V) - 8.4427'
x 10-8 (V)2
3,100.44 + 1.19041 (V) - 1.7288
x 10-5 (V)2
exp[4.73808 - 0.0628537(InV)
+ 0.0754345 (lnV)2]
0.05 (C)
24,000 < V < 500,000
000 < ¥ < 24,000
V < 1,000
0 < V < 500,000
c/i
w
o
-------
Table VIII-4 (Continued)
NONFERROUS METALS MANUFACTURING PHASE II CATEGORY
COST EQUATIONS FOR RECOMMENDED TREATMENT
AND CONTROL TECHNOLOGIES
Equipment
Equalization Basin
u>
to
Feed System, Caustic
Equation
C - 14,759.8 + 0.170817 (V) - 8.44271
x 10-8 (V)2
C » 3,100.44 +¦ 1.19041 (V) - 1 .7288
x 10-5 (V)2
C « exp[4.73808 - 0.0628537(InV)
+ 0.0754345 (lnV)2]
A = 0.05 (C)
Continuous feed:
C = exp[9.63461 + 8.36122 x 10-3 (InF)
+ 0.0241809 (InF)2]
A = exp[7.9707 - 4.45846 x 10-3 (InF)
+ 0.0225972 (InF)2] + 0.183 (HPY)(F)
Range of Validity
24,000 < V < 500,000
1,000
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a
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3
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t-i
CA
w
n
Batch feed:
C = exp[7.50026 + 0.199364 (InF)
+ 0.0416602 (InF)2]
A - (21)t16 + 0.5 (BPY)] + 0.131 (F)(HPY)
1.5 < F < 1,500
<
H
H
-------
Table VILI-4 (Continued)
Ui
UJ
UJ
Equipment
N0NFERR01S METALS MANUFACTURING PHASE II CATEGORY
COST EQUATIONS FOR RECOMMENDED TREATMENT
AND CONTROL TECHNOLOGIES
Equation
Low flow batch feed;
C = 250
A = 10.5 (BPY) + 0.131 (F) (HPY)
Feed System, Defoamer C = 980
A = 6.5 x 10-5 (X) (HPY)
Feed System, Lime
(Manual)
Feed System, Lime
(Batch)
C = 0
A - (DPY)[0.074 (B) + 5.25 (NB)]
C = 1,697.79 + 19.489 (B) - 0.036824 (B)2
C = 16,149.2 + 10.2512 (B) - 1.65864
x 10-3 (B)2
A = (BPY)[5.01989 + 0.0551812 (B)
- 1 .79331 x 10-5 (B)2] + 545
Range of Validity
X < 100
0 < X < 83,000
X < 2,000
1 < B < 200
B > 200
Q
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55
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s
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%
t-3
D
O
n
G
2
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25
in
M
o
i-3
Feed System, Lime
(Continuous)
exp[6.32249 + 1.70246 (InF)
- 0. 1371 86 ( InF) 2 f
exp[4.87322 + 1.78557 (InF)
+ 0. 136732 (InF)2 J + (F)(HPY)(LC)
10 < F < 1,000
-------
Table VIII-4 (Continued)
LJ
>fc»
Equipment
Feed System,
Ferrous Sulfate
NONFERROUS METALS MANUFACTURING PHASE II CATEGORY
COST EQUATIONS FOR RECOMMENDED TREATMENT
AND CONTROL TECHNOLOGIES
Equation
Feed System, Polymer
C = exp[10.1703 - 0.38694 (InF)
+ 0.0765919 (InF)2]
A = exp[9.696551 - 0.612972 (InF)
+0.0960144 (InF)2] + 0.0575 (F) (HPY)
C = exp[9.83111 + 0.663271 (InF)
+ 0.0557039 (InF)2]
A = 0.42 (F)(HPY) + 1050
C = 13,150 + 2515.2 (F)
A = exp[8.60954 + 0.04109 (InF)
+ 0.0109397 (InF)2] + 2.25 (F)(HPY)
Range of Validity
10.7 < F < 5350
0.04 < F < 0.5
0.5 < F < 12
o
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e
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2
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D
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3
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55
Feed System, Sodium
Sulfide (Manual)
Feed Syfetem, Sodium
Sulfide (Continuous)
C = 0
A = [0.240 (B) + 5.25 (NB)](DPY)
C = 1 3,953.3 f- 117.18 (F) - 0.069117 (F)2
A = [0.758002 + 0.140318 (F) - 8.6493
x 10-8 (F)2](HPY)
X < 2200
10 < F <5,350
Ui
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-------
Table VIII-4 (Continued)
U)
u»
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Equipment
Feed System,
Sulfuric Acid
Filter, Multimedia
Filter, Membrane
NONFERROUS METALS MANUFACTURING PHASE II CATEGORY
COST EQUATIONS FOR RECOMMENDED TREATMENT
AND CONTROL TECHNOLOGIES
Equation
C - expl8.1441 + 0.23345 (InF)
+ 0.0180092 (InF)2J
A = exp[7.36913 + 0.0133111 (InF)
+ 0.029219 (InF)2] + 0.03743 (F)(HPY)
C - 10,888 + 277.85 (SA) - 0.154337 (SA)2
A = exp[8.20771 + 0.275272 (InSA)
+ 0.0323124 (InSA)2]
C = 290.48 + 31.441 (Y) - 0.050717 (Y)2
A = [8.34253 x 10-3 + 0.173683 (SR)
- 4.1435 x 10-5 (SR)2J(HPY)
C = -2,922.48 + 60.6411 (Y) - 0.065206 (Y)2
A - [-0.0152849 + 0.172153 (SR) - 3.46041
x 10-6 (SR)2](HPY)
Range of Validity
0.01 < F < 3,200
7 < SA < 500
2 < Y < 140
140 < Y < 336
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3
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Granular Activated
Carbon
C = 1 .739 (CINT)(0.93662)
A = 1 . 739 (CLOS)(0.93662)
0 < CINT < 107
0 < CLOS < 107
-------
Table VIII-4 (Continued)
u>
UJ
0\
Equipment
Granular Activated
Carbon Columns
Granular Activated
Carbon, Off-site
Regenerat ion
Granular Activated
Carbon, On-site
Regeneration
NONFERROUS METALS MANUFACTURING PHASE II CATEGORY
COST EQUATIONS FOR RECOMMENDED TREATMENT
AND CONTROL TECHNOLOGIES
C = exp[9.649881 + 0.645947 (InDF)
+ 0.0572931 (InDF)2]
A = exp[7.3/615 + 0.570095 (InDF)
+ 0.196441 (InDF)2]
C = exp[7.602986 + 0.900958 (InCB)
- 9.70893 x 10-3 (InCB)2 J
A = 1.84214 + 4516.24 (LBC)
+ 3.66964 x 10-3 (LBC)2
C - exp[11.797 + 0.317114 (InLBC)
+ 8.85061 x 10-3 (InLBC)2J
A - exp[8.84373 + 0.490475 (InLBC)
+ 0.0252024 (InLBC)2] (HPB)
Range of Validity
2 < DF < 9
26.5 < CB < 530
3.4 < LBC < 342
56 < LBC < 3138
Q
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5
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Oil/Water Separator, C
Coalescent type A
5,542.07 + 65.7158 (Y) - 0.029627 (Y)2
783.04 + 6.3616 (Y) - 0.001736 (Y)2
0 < Y < 700
-------
Table VIII-4 (Continued)
Equipment
NONFERROUS METALS MANUFACTURING PHASE II CATEGORY
COST EQUATIONS FOR RECOMMENDED TREATMENT
AND CONTROL TECHNOLOGIES
Equation
Ranfte of Valid
Oil/Water Separator,
Belt-type
(Small Flow)
C
A
C
A
2370
1300
2900
1 500
OC < 25
OC > 25
Piping, Recycle
C = exp[6.55278 + 0.382166 (InD)
+ 0.133144 (InD)2] (0.01)(L)
A = 0
D > 1
Prefilter, Cartridge
C = 283.353 + 25.9111 (Y) - 0.058203 (Y)2
A = [0.118985 + 0.0803004 (SR) - 1.66003
x 10-5 (SR)2](HPY)
2 < Y < 140
C - -2,612.73 + 51.568 (Y) - 0.059361 (Y)2
A = [-3.82339 + 0.0937196 (SR) - 1.7736
x 10-5 (SR)2j(HPY)
140 < Y < 336
Pump, Centrifugal
C =
A
exp[6.31076 + 0.228887(lnY)
+ 0.0206172 (lnY)2]
exp[6.67588 + 0.031335 (lnY)
+ 0.062016 (lnY)2] (HPB)
3 < Y < 3,500
-------
Table VI11-4 (Continued)
NONFERROUS METALS MANUFACTURING PHASE II CATEGORY
COST EQUATIONS FOR RECOMMENDED TREATMENT
AND CONTROL TECHNOLOGIES
LO
UJ
00
Equipment
Pump, Sludge
Tank, Batch Reactor
Tank, Concrete
Tank, Large
Fiberglass
Equation
C = 2,264.31 + 21.0097 (Y) - 0.0037265 (Y)2
A = exp[7.64414 + 0.192172 (lnY)
+ 0.0202428 (lnY)2] (HPB)
C = exp[4.73808 - 0.0628537 (InV)
+ 0.0754345 (lnV)2j
C = 3,100.44 + 1.19041 (V) - 1.7288
x 10-5(V)2
A - 1,090 + 21 (BPY)
A « exp[8.65018 - 0.0558684 (lnX)
+ 0.0145276 (lnX)2]
C = 5,800 + 0.8V
A = 0.02 (C)
C = 3,100.44 + 1.19041 (V) - 1.7288
x 10-5 (V) 2
A - 0.02 (C)
Range of Validity
5 < Y < 500
57 < V < 1,000
1,000 < V < 24,000
X < 2,200
2,200 < X < 11,600
24,000 < V v 500,000
1,000 < V < 24,000
Q
W
53
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2
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55
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3
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Tank, Small
expf4.7308 - 0.0628537 (InV)
+ 0.0754345 (lnV)2j
0.02 (C)
57 < V < 1,000
-------
Table VIII-4 (Continued)
u>
U)
ID
Equipment
Tank, Large Steel
Tank, Small Steel
Vacuum Filter
NONFERROUS METALS MANUFACTURING PHASE II CATEGORY
COST EQUATIONS FOR RECOMMENDED TREATMENT
AND CONTROL TECHNOLOGIES
C =
A =
Equat ion
3,128.83 + 2.37281 (V) - 7.10689
x 10-5(V)2
14,759.8 + 0.170817 (V)
- 8.44271 x 10-8 (V)2
0.02 (C)
Range of Validity
500 < V < 12,000
V > 25,000
100 < V < 500
C - 692.824 + 6.16706 (V) - 3.95367
x 10-3(V)2
A = 0.02 (C)
C = 71,083.7 + 442.3 (SA) - 0.233807 (SA)2 9.4 < SA < 750
A = 17,471.4 + 677.408 (SA) - 0.484647 (SA)2
Vacuum Filter Housing C = (45)[308.253 + 0.836592 (SA)]
A = (4.96)[308.253 + 0.836592 (SA)]
9.4 < SA < 750
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2
m
z
U
o
o
w
25
t-3
W
m
o
(-3
-------
Table ¥111-4 (Continued)
NONFERROUS METALS MANUFACTURING PHASE II CATEGORY
COST EQUATIONS FOR RECOMMENDED TREATMENT
AND CONTROL TECHNOLOGIES
u>
o
VARIABLE DEFINITIONS
A = Direct annual costs (1982 dollars/year)
B = Batch chemical feed rate (pounds/batch)
BD = Batch chemical feed rate (pounds/day)
BPY = Number of batches per year
C - Direct capital, or equipment c^sts (1982 dollars)
CB = Activated carbon inventory (10 lb)
CINT = Initial carbon charge (lb)
CLOS = Carbon replacement requirement (lb)
CTON = Evaporative tons
D = Inner diameter of pipe (inches)
DF = Inner diameter of column (feet)
DPY = Days of operation per year
F = Chemical feed rate (pounds/hour)
G = Sludge disposal rate (gallons/hour)
HP = Power requirement (horsepower)
HPB = Fraction of time equipment is in operation
HPY = Plant operating hours (hours/year)
L = Length of piping (feet)
LBC = Activated carbon regeneration rate (Ib/hr)
LC = Lime cost ($/1b , March 7 982 )
NB = Number of batches per day
OC = Oil removed (gallons/day)
S = "CIarif ier surface area (square feet)
SA = Filter surface area (square feet)
SR = Solids removed by filter (grams/hour)
V = Tank capacity (gallons)
X = Wastewater flow rate (liters/hour)
Y = Wastewater flow rate (gallons/minute)
Q
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ts
2
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a
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CO
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<
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Hi
-------
Table VIII-5
COMPONENTS OF TOTAL CAPITAL INVESTMENT
Item
Number
Item
Cost
u>
1
3
4
5
8
9
1 0
1 1
1 5
1 7
18
Bare Module Capital Costs
Electrical & instrumentation
Yard piping
Enclosure
Pumping
Retrofit allowance
Total Module Cost
Engineering/admin. & legal
Cons truetion/yardwork
Monitoring
Total Plant Cost
Cont ingency
Contractor's fee
Total Construction Cost
Interest during construction
Total Depreciable Investment
Land
Working capital
Di rect capital costs from model3
0% of item 1
0%> of item 2
Included in item 1
Included in item 1
Included in item 1
Item 1 + items 2 through 6
10,0% of item 7
0% of item 7
0% of item 7
Item 7 + items 8 through 10
15% of item 11
10% of item 11
Item 11 + items 12 through 13
0% of item 1 4
Item 14 + it era 15
0%
0%
of
of
item
item
1 6
16
o
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25
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2
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53
H
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1 9
Total Capital Investment
Item 16 + items 17 through 18
aDirect capital costs include
installation, and delivery.
costs of equipment and required accessories,
-------
Table VIII-6
COMPONENTS OF TOTAL ANNUALIZED COSTS
ife
k;
Item
Number
20
21
22
23
24
25
I tern
Bare Module Annual Costs
Overhead
Monitoring
Taxes and Insurance
Amortization
Total Annualized Costs
Cost
Direct annual costs from model3
0% of item 16^
See footnote c
1% of item 16
CRF x item 16d
Item 20 + items 21 through 24
aDirect annual costs include costs of raw materials, energy, operating labor,
maintenance and repair.
t>I tem 16 is the total depreciable investment obtained from Table VI11-4 .
cSee page for an explanation of the determination of monitoring costs.
dThe capital recovery factor (CRF) was used to account for depreciation and
the cost of financing.
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-------
GENERAL DEVELOPMENT DOCUMENT SECT - VIII
TABLE VIII-7
WASTEWATER SAMPLING FREQUENCY
Wastewater Discharge (1/day) Sampling Frequency
0
36851
189251
378501
37850
Once per month
189250
Twice per month
378500
Once per week
946250
Twice per week
& above
Three times per
343
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VIII
TABLE VIII-8
COST. PROGRAM POLLUTANT PARAMETERS
Parameter
Units
Flow rate
mg/1
pH
mg/1
Temperature
mg/1
Total suspended solids
mg/1
Acidity (as CaC03)
mg/1
Aluminum
mg/1
Ammonia
mg/1
Antimony
mg/1
Arsenic
mg/1
Cadmium
mg/1
Chromium (+3)
mg/1
Chromium (+6)
mg/1
Cobalt
mg/1
Copper
mg/1
Cyanide (free)
mg/1
Cyanide (total)
mg/1
Fluoride
mg/1
Germanium
mg/1
I ron
mg/1
Lead
mg/1
Manganese
mg/1
Molybdenum
mg/1
Nickel
mg/1
Oil and Grease
mg/1
Phosphorus
mg/1
Selenium
mg/1
Silver
mg/1
Thallium
mg/1
Tin
mg/1
Titanium
mg/1
Zinc
mg/1
344
-------
Table VIII-9
FLOW REDUCTION RECYCLE RATIO AND ASSOCIATED COST ASSUMPTIONS
Condition
Act ion
u>
£>.
U!
Option A:
1. Actual flow from process* is greater
than Option A,
2. Actual flow from process is less than
Option A.
Options B and C:
1. Actual flow from process is greater 1.
than Option A and no in-process flow
reduction techniques are in place.
2. Actual flow from process is greater 2.
than Option A. The actual plant recycle
ratio is known and results in a flow
less than Option A but greater than
Option B.
3. Actual flow from process is greater 3.
than Option A. The actual plant recycle
ratio is known and results in a flow
less than Option B.
4. Actual flow from process is greater 4.
than Option A and the actual plant
recycle is unknown.
1. Reduce flow to Option A at zero cost.
Use flow to cost central treatment
system,
2. Use actual plant flow to cost central
treatment plant.
Reduce flow to Option A at zero cost.
Reduce flow to Option B using recycle
ratio.*
Reduce flow to Option A at zero cost.
Reduce flow to Option B using recycle
rat io.
Reduce flow to Option A at zero cost.
Set discharge from flow reduction
equipment equal to actual plant reduced
flow.
Reduce flow to Option A at zero cost.
Reduce flow to Option B using constant
recycle ratio.
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-------
Table VIII-9 (Continued)
FLOW REDUCTION RECYCLE RATIO AND ASSOCIATED COST ASSUMPTIONS
Condlt ion
Action
LO
as
Actual flow from process is less than
Option A (but greater than Option B) and
the actual plant recycle ratio is known
and results in a flow less than Option B.
Actual flow from process is less than
Option A (but greater than Option B) and
the actual plant recycle ratio is unknown,
zero, or results in a flow greater than
Option B.
Actual flow from process is less than
Option B using no flow reduction
techniques.
Set discharge from flow reduction
equipment equal to actual plant reduced
flow.
Set discharge from flow reduction
equipment equal to Option B,
Set discharge equal to actual plant
flow.
*Flow before any reported flow reduction techniques (i.e., holding tanks, cooling towers,
thickeners).
**The constant recycle ratio is calculated as: R = Option A Flow - Option B Flow.
Option A Flow
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Note:
Option A = Lime and settle.
Option B = Lime and settle with in-process flow reduction.
Option C - Lime, settle, and multimedia filtration with in-process flow reduction.
-------
Table VIII-10
NONFERROUS METALS MANUFACTURING (PHASE I) COMPLIANCE COSTS
SECONDARY SILVER SUBCATEGORY
PLANT XXXX
DISCHARGE STATUS; INDIRECT
u>
Option A
Option B
Option C
Total
RequI red
Total
RequI red
Total
Required
Equ ipment
Run
Cap 1ta1
Capital
Annual
Run
Capital
Capital
Annual
Run
Capi tal
Capital
Annual
Cyanide Precipitation
Ammonia Steam Stripping
Cooling Towers
EquallzatIon
1
2,800
2,800
1 ,900
1
2,800
2,800
1 ,900
1
2,800
2,800
1 ,900
Chemical Precipitation
1
9,000
9,000
4,300
1
9,000
9,000
4,300
1
9,000
9,000
4,300
Gravity Settling
(4)
(4)
(4)
Vacuum Filtration
(5)
(5)
(5)
Multimedia Filtration
1
1 ,700
1 ,700
1 ,200
Contract Hauling
1
0
0
1 ,300
1
0
0
1 ,300
1
0
0
1 ,300
Hold Tanks, Recycle
1
3,600
3,600
900
1
3,600
3,600
900
1
3,600
3,600
900
Segregation Costa
6.500
_6,50(!
0
6,500
6,500
0
6.500
6.500
0
Subtotal
21,900
21,900
8,400
21,900
21,900
8,400
23,600
23,600
9,600
System Capital Costs
8,212
8,212
8,212
8,212
8,850
8,850
Enc losure
0
0
0
Insurance and Taxes
301
30!
324
AmortlzatIon
5,329
5,329
5,743
Monitoring
1 ,440
1 ,440
1,440
TOTAL
30,112
30,112
t 5 ,470
30,112
30,112
15,470
32,450
32,450
17,107
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FOOTNOTES:
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All costs are in March, 1982 dollars.
System capital costs are calculated as 37,5 percent of the total direct capital costs (capital subtotal).
Amortization is calculated as 17./ percent of the total required capital coats.
Chemical precipitation operated In batch mode; gravity settling not costed.
Flow to vacuum filter la less than minimum for sizing (42 1/hr). Stream la contract hauled.
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VIII
TABLE VIII-11
NONFERROUS METALS MANUFACTURING WASTE GENERATION
(tons/yr)
Discharger Type
Direct Indirect
734336
*
*
*
1878
65a
3 . 5a
88a
896
17932
3361
0
695
0
Subcategory
Primary Aluminum
Secondary Aluminum
Primary Copper
Secondary Copper
Secondary Silver
Primary Lead
Primary Zinc
Metallurgical Acid Plants
Primary Tungsten
Primary Columbium & Tantalum
Secondary Lead
Primary Antimony
Bauxite Refining
Primary Beryllium
Primary Boron
Primary Cesium and Rubidium 0
Primary & Secondary Germanium 0
& Gallium
Secondary Indium 0
Secondary Mercury 0
Primary Molybdenum & Rhenium 1682
Secondary Molybdenum & Vanadium 850
Primary Nickel and Cobalt 10.4
Secondary Nickel 0
Primary Precious Metals & Mercury 11.4
Secondary Precious Metals 524
Primary Rare Earth Metals 0
Secondary Tantalum 173
Secondary Tin 2762
Primary & Secondary Titanium 339
Secondary Tungsten & Cobalt 562
Secondary Uranium 320
Primary Zirconium Hafnium 2624
NA
5697
NA
*
2893
NA
0 • 6a
3. 4a
1212
25003
0
0
0
0
0
108
170
0
0
0
0
423
0
1585
17
0
19.3
50.2
0.2
0
5.6
* Solid waste generation accounted for by existing BPT regulation
a - Sulfide precipitation sludge
348
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VIII
TABLE VII1-12
NONFERROUS METALS MANUFACTURING ENERGY CONSUMPTION
(kW-hr/yr)
Subcategory
BPT
1AT
PSES
Primary Aluminum
¦k
11079204
NA
Secondary Aluminum
*
884061
1613178
Primary Copper
*
166302
NA
Secondary Copper
*
*
179190
Secondary Silver
662074
711872
217053
Primary Lead
125247
1100028
NA
Primary Zinc
*
69564
13706
Metallurgical Acid Plants
*
469968
16666
Primary Tungsten
4600400
4641860
904665
Primary Columbium & Tantalum
3373589
3406603
1859916
Secondary Lead
1727280
1813408
3607300
Primary Antimony
393800
396500
NA
Bauxite Refining
0
0
NA
Primary Beryllium
1067300
1137000
NA
Primary Boron
0
0
0
Primary Cesium and Rubidium
0
0
0
Primary & Secondary Germanium
0
0
6253
& Gallium
Secondary Indium
NA
NA
5900
Secondary Mercury
0
0
0
Primary Molybdenum & Rhenium
1261200
1267200
NA
Secondary Molybdenum & Vanadium 926000
936000
NA
Primary Nickel and Cobalt
20600
28570
NA
Secondary Nickel
NA
NA
88300
Primary Precious Metals & Mercury 4224
5155
NA
Secondary Precious Metals
489000
497000
4981000
Primary Rare Earth Metals
43500
39400
26000
Secondary Tantalum
16000
18000
NA
Secondary Tin
576000
581000
319200
Primary & Secondary Titanium
680340
687150
340300
Secondary Tungsten & Cobalt
1150000
1185000
3700
Secondary Uranium
57000
66000
NA
Primary Zirconium & Hafnium
12210000
12264000
NA
NOTE; NA = not applicable
* Energy consumption was considered for the promulgated BPT
regulation; no additional energy consumption is attributed
to this regulation.
349
-------
GENERAL DEVELOPMENT DOCUMENT SECT - VIII
Stare
Executive
Routine to Call
Required Modules
Input
Desired
Modules
Input
User-Specified
Variables
Resi gn
Parameters
Call Cost
Equations For
Each Module
Du t pu t
Costs
Figure VII1-1
GENERAL LOGIC DIAGRAM OF COMPUTER COST MODEL
350
-------
GENERAL DEVELOPMENT DOCUMENT
SECT - VIII
ROW AND
conc8wm*non»
PKOM MtfVIOUC
MODULI
•PfCtFY
COW«TA*T».
DESJOW VALUES
DAT* FROM
fwkviously
UMTKEATID
WASTtWATlIt
'
1
AJ8UME INITIAL
VALUES fQ*
nncrctt
STREAMS
CGM*/T*
calculate
dcsion
VAiMt S
MA3
TEST PARAM.
ATEP1$) COM-
VfUGC?
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S. VAUJtS TO sS m
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•A4AMCCS AMD
DCSIQM VALUES
1
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00 to NEXT
MODULE
Figure V1II-2
LOGIC DIAGRAM OF MODULE DESIGN PROCEDURE
351
-------
GENERAL DEVELOPMENT DOCUMENT
SECT
- VIII
OUTPUT
COSTS
COMPUTE
system
COSTS
CAU. COST
EQUATIONS
CALL COST
EQUATIONS
MODULE N
components
MODULE 2
COMPONENTS
CALL MODULE
SUBROUTINES
MODULE 1
COMPONENTS
DESIGN VALUES
AND CONFIGURATION
FROM MATERIAL
iALANCE PROGRAM
COST
EQUATIONS
Figure VI11-3
LOGIC DIAGRAM OF THE COST ESTIMATION ROUTINE
352
-------
10°
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INFLUENT FLOW TO COOLING TOWER (l/hr)
Figure VIII-4
CAPITAL AND ANNUAL COSTS FOR COOLING TOWER/HOLDING TANK
-------
10°
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10'
10
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ur
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INFLUENT FLOW TO EQUALIZATION (l/hr )
M
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Figure VI11-5
CAPITAL AND ANNUAL COSTS FOR FLOW EQUALIZATION
-------
GENERAL DEVELOPMENT DOCUMENT
SECT - VIII
1
-1
CAPfTAL
y
"""annual
O3 104 10s
INFLUENT FLOW TO CYANIDE PRECIPITATION (l/hr )
Figure V111-6
CAPITAL AND ANNUAL COSTS FOR CYANIDE PRECIPITATION
-------
CAPITAL
ANNUAl
INFLUENT FLOW TO AMMONIA STEAM STRIPPING |l/hr|
Figure VI11-7
CAPITAL AND ANNUAL COSTS FOR AMMONIA STEAM STRIPPING
-------
CAPITAL
INFLUENT FLOW TO OIL/WATER SEPARATOR |l/hr|
Figure VIII-8
CAPITAL AND ANNUAL COSTS FOR OIL/WATER SEPARATION
-------
10°
OJ
<_n
00
04
00
1
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c
<
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t—
05
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10^
10°
INFLUENT FLOW TO CHEMICAL PRECIPITATION (l/hrj
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Figure VIII-9
CAPITAL AND ANNUAL COSTS FOR CHEMICAL PRECIPITATION
-------
GENERAL DEVELOPMENT DOCUMENT
SECT - VIII
*
"CAi
'1TAL
A
z\
MUAl
10 INFLUENT FLOW TO SULFIDE PRECIPITATION !l/hr ) ^
Figure VIII-10
CAPITAL AND ANNUAL COSTS FOR SULFIDE PRECIPITATION
359
-------
CAPITAL
ANNUAL
INFLUENT FLOW TO VACUUM FILTER (l/hr|
(3% SOLIDS)
Figure VIII-11
CAPITAL AND ANNUAL COSTS FOR VACUUM FILTRATION
-------
10°
u>
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X
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in
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10u
10'
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I02 103
INFLUENT FLOW TO HOLDING TANK (l/hr |
Figure VI11-12
CAPITAL AND ANNUAL COSTS FOR HOLDING TANKS/RECYCLE
10°
O
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MULTIMEDIA FILTRATION
CAPITAL
ANNUAL
CARmiDGE HI IHATION
CAPITAL
ANNUA!
INFLUENT FLOW TO MULTIMEDIA FILTRATION |l/hr)
Figure V1II-13
CAPITAL AND ANNUAL COSTS FOR MULTIMEDIA FILTRATION
-------
10°
US
M
to
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U
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VOLUME OF WASTE CONTRACT HAULED |l/hr I
M
Figure VIII-15
COSTS FOR CONTRACT HAULING
-------
GENERAL DEVELOPMENT DOCUMENT SECT - IX
SECTION IX
EFFLUENT QUALITY ATTAINABLE THROUGH APPLICATION OP THE
BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE
This section sets forth the effluent limitations attainable
through the application of best practicable control technology
currently available (BPT). It also serves to summarize changes
from previous rulemakings in the nonferrous metals manufacturing
category, and presents the development and use of the mass-based
production related effluent limitations.
A number of considerations guide the BPT analysis. First,
effluent limitations based on BPT generally reflect performance
levels achieved at plants in each subcategory equipped with the
best wastewater treatment facilities. The BPT analysis
emphasizes treatment facilities at the end of a manufacturing
process but can also include in-plant control techniques when
they are considered to be normal practice within the subcategory.
Finally, the Agency closely examines the effectiveness of the
various treatment technologies by weighing the pollutant removals
achievable by each treatment alternative and by assessing
installation and operational costs.
The limitations are organized by subcategory, and are presented
in Section II of each subcategory supplement.. The limitations
were developed based on the sampling, treatment effectiveness,
and cost data that have been presented in this document.
TECHNICAL APPROACH TO BPT
In the past, the technical approach for the nonferrous metals
manufacturing category considered each plant as a single
wastewater source, without specific regard to the different unit
processes that are used in plants within the same subcategory.
This approach may be appropriate for BPT which is generally based
upon end-of-pipe technology. In-process controls are generally
not used to establish BPT; however, they may be used as the basis
of BPT when they are widely used in the category. In reviewing
the existing BAT regulations and developing new BAT regulations,
the Agency closely examined each process and the potential for
implementing in-process controls. It became apparent that it was
best to establish effluent limitations and standards recognizing
specific waste streams associated with specific manufacturing
operations. This also results in more effective pollution
abatement by tailoring the regulation to reflect these various
wastewater sources. Currently promulgated BPT effluent
limitations and standards which have been developed using this
approach generally have not been modified.
This approach, referred to as the building block approach,
establishes pollutant discharge limitations for each source of
wastewater identified within the subcategory. Each wastewater
365
-------
GENERAL DEVELOPMENT DOCUMENT SECT - IX
source is allocated a discharge based on the average reported
discharge rates for that source. These flows are normalized
(related to a common basis) using a characteristic product ion
parameter associated with the wastewater source (e.g. volume of
wastewater discharged per unit mass of production). The mass
limitations established for a wastewater source are obtained by
multiplying the effluent concentrations attainable by the
selected BPT technology by the regulatory (production
normalized) flow for each wastewater source. Thus, the specific
pollutant discharge allowances for a plant's final discharge
permit are calculated by multiplying the appropriate production
rates with the corresponding mass limitations for each wastewater
source in that plant, and then summing the results. This
calculation is performed to obtain the one-day maximum and the
monthly average limitations. It is important to note that the
plant need only comply with the total mass limitations for the
discharge and not the flow allowances or concentrations. In
cases where process wastewaters and nonprocess waters not
specifically regulated by this proposal are discharged together
from a facility, the permit authority must treat the nonprocess
segment on a case-by-case basis.
Although each waste stream may not i nclude each selected
pollutant, discharge allowances are provided for all pollutants
in every waste stream from the same subcategory because each
waste stream contributes to the total loading of a combined waste
treatment system. Since a discharge allowance is included for
each pollutant in every waste stream, facilities would not be
required to reduce pollutant concentrations below the performance
limits of the technology. Instead, this approach allows plants to
achieve the performance determined for the technology at the
plant discharge point. Therefore, the mass limitation for each
pollutant in each building block is the product of the
concentration achievable by the technology basis of the
limitation and the regulatory flow for that building block.
In determining the technology basis for BPT, the Agency reviewed
a wide range of technology options and selected four alternatives
which could be applied to nonferrous metals manufacturing as BPT
options. These options include:
1. Option A - End-of-pipe treatment consisting of chemical
precipitation and clarification, and preliminary treatment,
where necessary, consisting of oil skimming, cyanide
precipitation, sulfide precipitation, iron coprecipitation,
and ammonia air or steam stripping. This combination of
technologies reduces toxic metals and cyanide, conventional,
and nonconventional pollutants. Ion exchange end-of-pipe
treatment is also included in Option A where necessary to
reduce certain nonconventional pollutants.
2. Option B - Option B is equal to Option A preceded by flow
reduction of process wastewater through the use of cooling
towers for contact cooling water and holding tanks for all
other process wastewater subject to recycle.
366
-------
GENERAL DEVELOPMENT DOCUMENT SECT - IX
3. Option C - Option C is equal to Option B plus end-of-
pipe polishing filtration for further reduction of
priority metal pollutants and TSS.
4. Option E - Option E consists of Option C plus activated
carbon adsorption applied to the total plant discharge as a
polishing step to reduce toxic organic concentrations.
Two additional technologies, activated alumina and reverse
osmosis, were evaluated prior to proposing mass limitations for
this category. Activated alumina treatment was included for
reduction of fluoride and arsenic concentrations. Reverse
osmosis was considered so that complete recycle of all process
wastewater could be attained. However, both of these
technologies were rejected because they are not demonstrated in
the nonferrous metals manufacturing category, nor are they
clearly transferable.
For each of the selected options, the mass of pollutant removed
and the costs associated with application of the option were
estimated. A description of the pollutant removal estimates
associated with the application of each option is presented in
Section X, while the cost methodology is presented in Section
VIII.
MODIFICATIONS TO EXISTING BPT EFFLUENT LIMITATIONS
Prior to this rulemaking session, BPT effluent limitations were
promulgated for nine of the 31 nonferrous metals manufacturing
subcategor ies:
1. bauxite refining,
2. primary aluminum smelting,
3. secondary aluminum smelting,
4. primary copper smelting,
5. primary electrolytic copper refining,
6. secondary copper,
7. primary lead,
8. primary zinc, and
9. metallurgical acid plants.
On February 17, 1983, four new subcategories were proposed for
inclusion in the nonferrous metals manufacturing point source
category (48 FR 7032). No effluent limitations had previously
been promulgated for these subcategories.
1. primary tungsten,
2. primary columbium-tantalum,
3. secondary silver, and
4. secondary lead.
On June 27, 1984, 20 new subcategories were proposed for
inclusion in the nonferrous metals manufacturing point source
category (49 FR 26352.) There had been no previous effluent
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limitations developed for these 20 subcategories. Following
proposal, EPA decided to exclude two of the 20 subcategories,
primary boron and primary cesium and rubidium, from regulation.
The 20 new subcategories EPA proposed for regulation are listed
below:
1. primary antimony
2. primary beryllium
3. primary boron
4. primary cesium & rubidium
5. primary and secondary germanium and gallium
6. secondary indium
7. secondary mercury
8. primary molybdenum and rhenium
9. secondary molybdenum and vanadium
10. primary nickel and cobalt
11. secondary nickel
12. primary precious metals and mercury
13. secondary precious metals
14. primary rare earth metals
15. secondary tantalum
16. secondary tin
17. primary and secondary titanium
18. secondary tungsten and cobalt
19. secondary uranium
20. primary zirconium and hafnium
EPA modified BPT effluent limitations for the primary lead
subcategory and secondary aluminum subcategory because new data
and information submitted to the Agency made it necessary to
revise these limits. EPA is modified the metallurgical acid
plants subcategory to include acid plants associated with primary
molybdenum, primary zinc and primary lead. In addition,
modifications were promulgated for existing stormwater exemptions
previously promulgated in the primary lead subcategory.
PRIMARY LEAD
The 1975 promulgated BPT for this subcategory is based on the
complete recycle and reuse of slag granulation wastewater (or dry
slag dumping), dry air scrubbing, and treatment and impoundment
(subject to allowances for net precipitation and catastrophic
precipitation events) of acid plant blowdown. As mentioned
earlier, acid plant wastewater is now included in the
metallurgical acid plants subcategory. This suggests that BPT
for primary lead should be zero discharge. Since 1975, however,
additional data collected by the Agency support the need for
discharge of wastewater from slag granulation. Although it was
previously thought that slag granulation is a net water consuming
operation, the additional data show that at least one plant uses
an ore with a lead content sufficiently high to justify recycling
blast furnace slag into the sintering machine to recover the
remaining lead content. For this reason, EPA modified the 1975
promulgated BPT for this subcategory to allow a discharge from
dross slag granulation operations.
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
METALLURGICAL ACID PLANTS
On February 17, 1983, EPA proposed to expand the metallurgical
acid plants subcategory to include metallurgical acid plants at
primary lead and primary zinc smelters as well as those at
primary copper smelters.
On June 27, 1984, EPA proposed to include metallurgical acid
plants associated (i.e., on-site) with primary molybdenum
roasters as part of the metallurgical acid plants subcategory.
These operations, which were previously regulated under their
respective primary metal subcategories, are now subject to
limitations for acid plants. All these plants would accordingly
have identical effluent limitations and standards, with one
exception: acid plants associated with primary molybdenum
roasters would also have fluoride and molybdenum regulated in
their effluent. In making this determination, that all acid
plants be regulated in one subcategory, the Agency considered the
way in which acid plants are operated when associated with the
primary smelters and the characteristics of the wastewater
generated by each type to acid plant. Our conclusion is that
these processes, rate of process discharge, and wastewater
matrices are similar, justifying a single subcategory for all
acid plants.
Metallurgical acid plants are constructed on-site with primary
copper, lead, zinc, and molybdenum smelters to treat the smelter
emissions, remove the sulfur dioxide, and produce sulfuric acid
as a marketable by-product. Although two basic technologies,
single contact and double contact, are used in the industry, the
Agency found no predominance of either technology in place in
plants of the four metal types. Finally, the Agency found no
difference in the characterization of the wastewater at plants
which burn supplemental sulfur.
The processes are also similar in terms of waste streams
generated. Wastewaters are typically combined in acid plants into
a single waste stream (acid plant blowdown). Principal streams
going into the blowdown (compressor condensate, blowdown from
acid plant scrubbing, mist precipitation, mist elimination, and
steam generation) are common to all four types of plants.
The wastewater matrices from all four types of acid plants also
are similar. The Agency reviewed the analytical data that were
obtained in sampling programs described in Section V and compared
the characteristics of untreated acid plant blowdown from plants
associated with each of the four primary metals considered. There
were similar concentrations (i.e., in the same order of
magnitude) of antimony, arsenic, chromium, mercury, and selenium,
among the four. All of these metals were present at
concentrations that are treatable to the same effluent
concentration upon application of chemical precipitation and
sedimentation or chemical precipitation, sedimentation and
multimedia filtration, and are within the range used in
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
calculating treatment effectiveness for these technologies. One
dissimilarity which was observed between molybdenum acid plant
wastewater matrices and the matrices associated with other acid
plants is that treatable concentrations of fluoride and
molybdenum are present in molybdenum acid plant wastewaters and
not in the wastewaters from other metallurgical acid plants. The
Agency is establishing limitations for fluoride and molybdenum in
discharges from metallurgical acid plants associated with primary
molybdenum roasters. Molybdenum limitations are based on iron
co-precipitation preliminary treatment.
Therefore, in light of these essential similarities of process,
wastewater flow and composition, we have chosen to include all
acid plants in a single subcategory.
MODIFIED APPROACH TO STORMWATER
Stormwater, in all effluent limitations and standards, is only
considered process wastewater when commingled with actual process
wastewater. If commingling occurs, the stormwater, which usually
does not contain significant pollutant loadings, is contaminated
with the pollutants contained in the process wastewater, and as
such should be subject to treatment. No allowance, however, is
given for this additional flow, since stormwater is or can be
segregated from the process wastewater.
Existing BFT effluent limitations for the nonferrous metals
subcategories primary copper smelting, secondary copper, and
primary lead have promulgated stormwater exemptions. Facilities
in these three subcategories are subject to a zero discharge
requirement according to promulgated BPT effluent limitations;
however, facilities meeting certain design capacity requirements
could discharge, regardless of effluent quality, a volume of
water falling within the impoundment in excess of the 10-year,
24-hour storm, when a storm of at least that magnitude occurred.
Further, facilities in the secondary copper and primary lead
subcategories can discharge once per month, subject to
concentration-based effluent limitations, a volume of water equal
to the difference between precipitation and evaporation falling
on the impoundment in that month.
The Agency made some revisions to some of these impoundment-based
regulations in 1980 for primary copper smelting and electrolytic
refining BPT. The 1983-1989 rulemaking session promulgated
revisions to others. The revised regulations are based on end-
of-pipe treatment using hardware (lime precipitation and
sedimentation technology using clarifiers). By eliminating
impoundments, the need for a net precipitation allowance and
stormwater discharge (subject to an exception discussed below) is
eliminated.
The Agency is reluctant to issue limitations based on
impoundments for a number of reasons:
1. Discharge from impoundments can be as a "slug,"
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
allowing potentially heavy and damaging pollutant
loadings to be discharged all at once?
2. Impoundments allow dilution of heavily contaminated
process wastewaters with relatively cleaner process
streams;
3. Net precipitation limitations are hard to calculate
because of periodic shifts between net precipitation
and net evaporation;
4. Impoundments pose a risk of groundwater contamination;
and,
5. Impoundment-based regulations effectively require the
Agency to specify impoundment design.
For reference, see generally 45 FR at 44926 (July 2, 1980),
revising impoundment-based regulations in the primary copper
smelting and electrolytic refining subcategories. In addition,
plants within these subcategories have, in many cases, already
installed hardware-based lime precipitation and sedimentation
technology, so that these technologies are now BFT or BAT for
these subcategories.
In light of these considerations, an allowance for net
precipitation is not included for BFT for the primary lead
subcategory because the effluent limitations for BFT are not
based on settling and evaporation impoundments. EPA is not
promulgating any modifications to previously promulgated BPT
effluent limitations for the primary copper smelting and
secondary copper subcategories.
It is recognized that this approach to catastrophic rainfalls
varies from the approach used for the ore mining and dressing
category (47 FR 54603). In that regulation EPA required only
that the impoundments be designed and operated so as to contain a
10-year, 24-hour storm, while this promulgated regulation
requires that no discharge from the impoundment may occur except
when a 10-year, 24-hour storm occur s. This difference is
justified by the fact that the nonferrous metals manufacturing
allowance applies only to water falling on the surface of the
impoundment while the ore mining allowance applies to stormwater
drainage from various processing locations at the ore mine and
mill. The relative surface area of a nonferrous manufacturing
impoundment is a small fraction of the area drained at an ore
mine or mill. Therefore, the quantity of stormwater that must be
contained at a nonferrous plant impoundment is much smaller,
making containment of the stormwater under the provisions of this
regulation achievable. The Agency believes that decisions
regarding stormwater are site-specific and are best handled based
on the judgment of individual permit writers.
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
BPT OPTION SELECTION
The treatment option selected for the technology basis of BPT
throughout the category is Option A (chemical precipitation and
sedimentation, with ammonia steam or air stripping, oil skimming,
sulfide precipitation, iron co-precipitation and cyanide
precipitation pretreatment, and ion-exchange end-of-pipe
treatment where appropriate). Chemical precipitation,
sedimentation, and ammonia stripping are widely demonstrated at
plants with the best treatment practices in the nonferrous metals
manufacturing category. Of the 240 discharging plants (shown by
subcategory in table IX-1, (page 384), 133 plants have treatment
to remove metals and suspended solids, one plant practices oil
skimmig, one plant has technology for cyanide precipitation,
eight have technology for cyanide oxidation, 11 practice ammonia
stripping, three employ ion exchange and 13 practice end-of-pipe
filtration. The remainder of the dischargers did not report any
treatment for their nonferrous metals manufacturing wastewaters.
The preponderance of technology is chemical precipitation and
sedimentation equipment. Multimedia filtration (Option C) as an
add-on polishing step to the precipitation and sedimentation
system was not selected at BPT since it was less widely
demonstrated.
Recycle after treatment consisting of lime precipitation and
sedimentation is practiced at one plant. Thirty-nine plants
practice recycle of scrubber water without any treatment, and two
plants practice recycle of process water using cooling towers.
Between 1975 and 1980, BPT effluent limitations were promulgated
for nine of the 36 nonferrous metals manufacturing subcategories,
namely, bauxite refining, primary aluminum, secondary aluminum,
primary copper smelting, primary electrolytic copper refining,
secondary copper, primary lead, primary zinc, and metallurgical
acid plants. Of the remaining 27 subcategories, EPA has reserved
setting BPT limitations for the following three subcategories
because there are no existing direct discharging plants in these
subcategories;
1. Secondary Indium
2. Secondary Mercury
3. Secondary Nickel
As discussed earlier, EPA has excluded the following five sub-
categories from limitations.
1. Primary Boron
2. Primary Cesium and Rubidium
3. Primary Lithium
4. Primary Magnesium
5. Secondary Zinc
Effluent BPT limitations were promulgated for the following 18
subcategories in 1985;
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
1. Primary Tungsten
2. Primary Columbium-Tantalum
3. Secondary Silver
4. Secondary Lead
5. Primary Antimony
6. Primary Beryllium
7. Primary and Secondary Germanium and Gallium
8. Primary Molybdenum and Rhenium
9. Secondary Molybdenum and Vanadium
10. Primary Nickel and Cobalt
11. Primary Precious Metals and Mercury
12. Secondary Precious Metals
13. Secondary Tantalum
14. Secondary Tin
15. Primary and Secondary Titanium
16. Secondary Tungsten and Cobalt
17. Secondary Uranium
18. Primary Zirconium and Hafnium
Briefly discussed below are descriptions of the options selected
for each of these 18 subcategories. A discussion of primary lead
and secondary aluminum BPT option selection will also be
presented since limitations for these subcategories were
modified. The mass limitations developed for these subcategories
are presented in Section II of this document and the
corresponding supplements. Table IX-2 (page 386) presents the
pollutants selected for limitation in each of the subcategories.
PRIMARY LEAD
The technology basis for the BPT limitations is lime
precipitation and sedimentation technology to remove metals and
solids from combined wastewaters and to control pH. This
technology is demonstrated at two primary lead smelters and will
remove an estimated 4,286 kg/yr of toxic metals from the
estimated raw discharge. Removal of TSS from raw discharge is
estimated at 261,130 kg/yr. The capital and annual costs for
achieving BPT are estimated at $0.24 million (March 1982 dollars)
and $0.11 million, respectively.
PRIMARY TUNGSTEN
The technology basis for the BPT limitations is lime
precipitation and sedimentation technology to remove metals and
solids from combined wastewaters and to control pH, and ammonia
steam stripping to remove ammonia. Lime and settle technology is
already inplace at three direct dischargers for this subcategory.
Ammonia steam stripping is used by one direct discharger.
Implementation of the promulgated BPT limitations will result in
the removal of 5,350 kg/yr of toxic metals from raw discharge
estimates. Removal estimates from raw discharge for ammonia is
141,000 kg/yr and 50,300 kg/yr of TSS. The capital and annual
costs for achieving BPT are estimated at $0.62 million (March
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
1982 dollars) and $1.0 million, respectively.
PRIMARY COLUMBIUM-TANTALUM
The technology basis for BPT effluent mass limitations is lime
precipitation and sedimentation to control toxic metals, TSS, pH
and fluoride, and ammonia steam stripping. Lime and settle
technology is currently inplace at all three direct dischargers.
Ammonia steam stripping is currently used at two of the three
direct discharging facilities.
Application of BPT treatment will result in the removal of 61,000
kg/yr of toxic pollutants, 1,692,000 kg/yr of conventional
pollutants, and 941,000 kg/yr of ammonia from raw discharge
estimates. The estimated capital investment cost of BPT is
$0.680 million (March 1982 dollars) and the estimated annual cost
is $1 .14 million. These costs represent wastewater treatment not
currently in place.
SECONDARY SILVER
The technology basis for BPT effluent mass limitations is lime
precipitation and sedimentation to remove toxic metals and TSS
and to control pH. Ammonia steam stripping is applied as
pretreatment for removal of ammonia. Lime and settle treatment
is currently in place at five direct dischargers, while ammonia
steam stripping is transferred from the columbium-tantalum and
tungsten subcategories.
The promulgated BPT will result in the removal of 30,900 kg/yr of
toxic pollutnts and 664,000 kg/yr of ammonia from estimated raw
discharge levels. The estimated capital investment cost of BPT
is $0.11 million (March 1982 dollars) and the est imated annual
cost is $0.31 million. These costs represent wastewater
treatment equipment not currently in place.
SECONDARY LEAD
The technology basis for BPT effluent mass limitations for the
secondary lead subcategory is lime precipitation and
sedimentation to control toxic metals, pH, and TSS. This
technology is currently inplace at five discharging facilities in
the secondary lead subcategory.
The promulgated BPT will result in the removal of 25,350 kg/yr of
toxic pollutants and 2,852,000 kg/yr of conventional pollutants
from estimated raw discharge levels. The estimated capital
investment cost of BPT is $1.6 million (March 1982 dollars) and
the estimated annual cost is $0,684 million. These costs
represent wastewater treatment equipment not currently in place.
PRIMARY ANTIMONY
The technology basis for the BPT limitations is lime
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
precipitation and sedimentation technology to remove metals and
solids from combined wastewaters and to control pH and sulfide
precipitation preliminary treatment. Lime and settle technology
is inplace at the one discharger in this subcategory. Sulfide
precipitation is necessary to ensure that large amounts of
arsenic present in the raw wastes are removed to the desired
level.
Implementation of the BPT limitations will remove annually an
estimated 17,522 kg of priority metals and 26,156 kg of
pollutants including TSS from the current discharge. We project
a capital cost of approximately $196,350 and an annualized cost
of approximately $554,180 for achieving BPT.
More stringent technology option were not selected for BPT since
they require in-process changes or end-of-pipe technologies less
widely practiced in the subcategory, and, therefore, are more
appropriately considered under BAT.
PRIMARY BERYLLIUM
The technology basis for the BPT limitations is chemical
precipitation and sedimentation technology to remove metals and
solids from combined wastewaters and to control pH and fluoride
along with scrubber liquor recycle, and cyanide precipitation and
ammonia steam stripping preliminary treatment. Lime and settle
technology is already in place at the one discharger in the
subcategory.
Implementation of BPT limitations will remove an estimated 2,698
kg/yr of priority metal pollutants and cyanide, 69,943 kg/yr of
ammonia, and 131,734 kg/yr of pollutants including TSS from the
raw wastewater. We project $226,500 in capital costs and
$211,200 in annual costs for achieving promulgated BPT.
PRIMARY AND SECONDARY GERMANIUM AND GALLIUM
The technology basis for the BPT limitations is chemical
precipitation and sedimentation technology to remove metals,
fluoride, and solids from combined wastewaters and to control pH.
The pollutants specifically included for regulation at BPT are
arsenic, lead, zinc, fluoride, TSS, and pH.
Although there are no existing direct dischargers in this
subcategory, BPT is promulgated for any existing zero discharger
that elects to discharge at some point in the future. This
action is necessary because wastewaters from germanium and
gallium operations which contain significant loadings of priority
pollutants are currently being disposed of in a RCRA - permitted
surface impoundment.
More stringent technology options were not selected for BPT since
they require in-process changes or end-of-pipe technologies less
widely practiced in the subcategory, and, therefore, are more
appropriately considered under BAT.
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
The cost and specific removal data for this subcategory are not
presented here because the data on which they are based have been
claimed to be confidential.
PRIMARY MOLYBDENUM AND RHENIUM
The technology basis for the BPT limitations is chemical
precipitation and sedimentation technology to remove metals and
solids from combined wastewaters and to control pH, and ammonia
steam stripping and iron co-precipitation preliminary treatment.
All to these technologies except iron co-precipitation are
already in-place at one to the two dischargers in the
subcategory.
Implementation of the BPT limitations will remove annually an
estimated 73,644 kg to priority metals, 737 kg of molybdenum,
63,443 kg of ammonia, and 51,529 kg of TSS from the current
discharge. While one discharging plant has the equipment inplace
to comply with BPT, we do not believe that plant is currently
achieving the BPT mass limitations. The cost data for this
subcategory are not presented here because the data on which they
are based have been claimed to be confidential.
More stringent technology options were not selected for BPT since
they require in-process changes or end-of-pipe technologies less
widely practiced in the subcategory, and, therefore, are more
appropriately considered under BAT.
SECONDARY MOLYBDENUM AND VANADIUM
The technology basis for the BPT limitations is iron co-
precipitation, chemical precipitation and sedimentation
technology to remove metals and solids from combined wastewaters
and to control pH, and air stripping to remove ammonia. Except
for iron co-precipitation, these technologies are already in
place at the one discharger in the subcategory.
Implementation of the BPT limitations will remove annually an
estimated 319 kg of priority metals and cyanide, 18,477 kg of
molybdenum, 563,160 kg of ammonia, and 28,136 kg of TSS from the
raw waste load. Although the one discharging facility in this
subcategory has some of the technology in place to comply with
BPT, we do not believe that the plant is currently achieving the
BPT mass limitations. The cost data for this subcategory are not
presented here because the data on which they are based have been
claimed to be confidential.
More stringent technology options were not selected for BPT since
they require in-process changes or end-of-pipe technologies not
practiced at the one plant in the subcategory. These
technologies must, therefore, be transferred from other
subcategories where the technologies have been defined as BAT
rather than BPT.
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
FRIMARY NICKEL AND COBALT
The technology basis for the BPT limitations is chemical
precipitation and sedimentation technology to remove metals and
solids from combined wastewaters and to control pH, and ammonia
steam stripping to remove ammonia. Chemical precipitation and
sedimentation technology is already inplace at the one discharger
in the subcategory.
Implementation of the BPT limitations will remove annually an
estimated 241 kg of priority metals and 252 kg of total
pollutants from the current discharge. While the one discharging
plant has the equipment inplace to comply with BPT, we do not
believe that the plant is currently achieving the BPT mass
limitations. The cost data for this subcategory are not
presented here because the data on which they are based have been
claimed to be confidential.
More stringent technology options were not selected for BPT
since they require in-process changes or end-of-pipe
technologies not practiced at the one plant in the subcategory.
These technologies must, therefore, be transferred from other
subcategories where the technologies have been defined as BAT
rather than BPT.
PRIMARY PRECIOUS METALS AND MERCURY
The technology basis for the BPT limitations is chemical
precipitation, sedimentation and ion exchange technology to
remove metals and solids from combined wastewaters and to control
pH, and oil skimming to remove oil and grease. Lime and settle
technology is in place at the one discharger in this subcategory.
Implementation of the BPT limitations will remove annually an
estimated 50,442 kg of priority metals and 53,768 kg of total
pollutants including TSS from the raw waste load. We project a
capital cost of $2,200 and an annualized cost of $26,814 for
achieving proposed BPT limitations.
More stringent technology options were not selected for BPT since
they require in-process changes or end-of-pipe technologies less
widely practiced in the subcategory, and, therefore, are more
appropriately considered under BAT.
SECONDARY PRECIOUS METALS
The technology basis for the BPT limitations is chemical
precipitation, sedimentation and ion exchange technology to
remove metals and solids from combined wastewaters and to
control pH, ammonia steam stripping pretreatment to remove
ammonia, and cyanide precipitation pretreatment to remove free
and complexed cyanide. Chemical precipitation and sedimentation
technology is already in place at 20 of the dischargers in the
subcategory. One plant has cyanide precipitation in place.
Although ammonia steam stripping is not currently practiced by
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
any of the plants in this subcategory# air stripping is practiced
at one plant and steam stripping is demonstrated at plants in
other nonferrous metals manufacturing subcategories.
Some of the plants in this subcategory have unusually high zinc
levels. For those plants, costs were developed for two-stage
precipitation using sulfide polishing as the second stage.
Sulfide controls zinc to the desired levels and helps overcome
complexation problems. Sulfide costs were included in the economic
impact analysis.
Implementation of the BPT limitations will remove annually an
estimated 94 kg of priority pollutants (which include 63 kg of
cyanide), and 4,677 of total pollutants, which include 494 kg of
ammonia, and 2,946 kg of TSS from the cur rent discharge. The
cost and specific removal data for this subcategory are not
presented here because the data on which they are based have been
claimed to be confidential.
More stringent technology options were not selected for BPT since
they require in-process changes or end-of-pipe technologies less
widely practiced in the subcategory, and, therefore, are more
appropriately considered under BAT.
PRIMARY RARE EARTH METALS
EPA has withdrawn the BPT limitations that were promulgated for
the Primary Rare Earth Metals Subcategory on September 20, 1985.
These limitations were withdrawn because EPA failed to adequately
address the sole direct discharging plant's comments in the
Administrative Record. Therefore, national BPT limitations are
not available for this subcategory, and applicable plant's
effluent limitations will need to be developed by the local
permitting authority through the NPDES program.
SECONDARY TANTALUM
The technology basis for the BPT limitations is chemical
precipitation and sedimentation technology to remove metals and
solids from combined wastewaters and to control pH. These
technologies are already inplace at three dischargers in the
subcategory.
Implementation of the BPT limitations will remove annually an
estimated 26,268 kg of priority metals, 1,490 kg of tantalum, and
51,392 kg of total pollutants including TSS from the current
discharge. The cost and specific removal data for this
subcategory are not presented here because the data on which they
are based have been claimed to be confidential.
More stringent technology options were not selected for BPT since
they require in-process changes or end-of-pipe technologies not
practiced by any of the three existing plants in the subcategory.
These technologies must, therefore, be transferred from other
subcategories where the technologies have been defined as BAT
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
rather than BPT.
SECONDARY TIN
The technology basis for the BPT limitations is chemical
precipitation and sedimentation technology to remove metals,
fluoride, and solids from combined wastewaters and to control pH,
with preliminary treatment consisting of cyanide precipitation
for certain building blocks. Chemical precipitation and
sedimentation technology is already inplace at two of the three
direct dischargers in the subcategory.
Implementation of the BPT limitations will remove annually from
raw discharge an estimated 688 kg of priority metals, 144 kg of
cyanide, 237,220 kg of fluoride, and 506,900 kg of TSS, for a
total pollutant removal of 800,967 kg. Projected capital costs
are estimated to be approximately $841,285 while annual costs are
estimated to be $692,625. The Agency has determined that the
pollutant reduction benefits associated with compliance justify
the costs for this subcategory.
More stringent technology options were not selected for BPT since
they require in-process changes or end-of-pipe technologies less
widely practiced in the subcategory, and, therefore, are more
appropriately considered under BAT.
PRIMARY AND SECONDARY TITANIUM
The technology basis for the BPT limitations is chemical
precipitation and sedimentation technology to remove metals and
solids from combined wastewaters and to control pH, and oil
skimming preliminary treatment for streams with treatable
concentrations of oil and grease. These technologies are already
in place at two of the four direct dischargers in the
subcategory. The pollutants specifically regulated at BPT are
chromium, lead, nickel, titanium, oil and grease, TSS, and pH. We
have exempted from regulation facilities which do not practice
electrolytic , recovery of magnesium and which use vacuum
distillation instead of leaching to purify titanium sponge. We
are promulgating these regulations for all other titanium plants
and the two-tiered regulation as proposed is not promulgated.
Implementation of the BPT limitations will remove annually an
estimated 217 kg of priority metals, 5,791 kg of titanium, and
64,446 kg of TSS from the raw waste load. While two plants have
the equipment in place to comply with BPT, we do not believe
that the plants are currently achieving the BPT limitations. We
project a capital cost of $644,500 and annualized cost of
$505,300 for achieving the BPT limitations.
More stringent technology options were not selected for BPT since
they require in-process changes or end-of-pipe technologies less
widely practiced in the subcategory, and, therefore, are more
appropriately considered under BAT.
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
SECONDARY TUNGSTEN AND COBALT
The technology basis for the BPT limitations is chemical
precipitation and sedimentation technology to remove metals and
solids from combined wastewaters and to control pH, ammonia steam
stripping to remove ammonia and oil skimming to remove oil and
grease. Chemical precipitation and sedimentation technology is
already inplace at three direct dischargers in the subcategory.
Implementation of the BPT limitations will remove annually an
estimated 150,600 kg of priority metals, 108,700 kg of TSS, and
420,200 of total pollutants from the current discharge. The cost
and specific removal data for this subcategory are not presented
here because the data on which they are based have been claimed
to be confidential.
More stringent technology options were not selected for BPT since
they require in-process changes or end-of-pipe technologies less
widely practiced in the subcategory, and, therefore, are more
appropriately considered under BAT.
SECONDARY URANIUM
The technology basis for the BPT limitations is chemical
precipitation and sedimentation technology to remove metals and
solids from combined wastewaters and to control pH. Chemical
precipitation and sedimentation technology is already in place
at the one discharger in the subcategory.
Implementation of the BPT limitations will remove annually an
estimated 100 kg of priority metals and 5,034 kg of total
pollutants including 651 kg of TSS from the estimated raw waste
load. While the one discharging plant has the equipment in place
to comply with BPT, we do not believe that the plant is cur rently
achieving the BPT limitations. We project capital and annual
costs of 554,800 and $90,400 (1982 dollars), respectively, for
modifications to technology presently in-place at the discharging
facility to achieve BPT regulations.
More stringent technology options were not selected for BPT since
they require in-process changes or end-of-pipe technologies not
practiced by any of the plants in the subcategory. These
technologies must, therefore, be transferred from other
subcategories where the technologies have been defined as BAT
rather than BPT.
PRIMARY ZIRCONIUM AND HAFNIUM
The technology basis for the BPT limitations is recycle of
scrubber liquors, chemical precipitation and sedimentation
technology to remove metals and solids from combined wastewaters
and to control pH, plus ammonia steam stripping and cyanide
precipitation preliminary treatment to streams containing ammonia
380
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
and cyanide. Chemical precipitation and sedimentation technology
and ammonia steam stripping is already in-place at one discharger
in the subcategory. The pollutants specifically regulated at BPT
are chromium, cyanide, lead, nickel, ammonia, TSS r and pH. We
are now exempting from national regulation facilities which only
produce zirconium or zirconium-nickel alloys by magnesium
reduction of Zr02• These BPT limitations apply to all other
zirconium-hafnium facilities.
Implementation of the BPT limitations will remove annually an
estimated 14,110 kg of priority metals and cyanide, and 19,4
million kg of pollutants including 38,240 kg of TSS from the raw
waste load. The cost data for this subcategory are not presented
here because the data on which they are based have been claimed
to be confidential.
More stringent technology options were not selected for BPT since
they require in-process changes or end-of-pipe technologies less
widely practiced in the subcategory, and, therefore, are more
appropriately considered under BAT.
THE BUILDING BLOCK APPROACH IN DEVELOPING PERMITS
A plant is to receive a discharge allowance for a particular
building block only it it is actually operating that particular
process. In this way, the building block approach recognizes and
accommodates the fact that not all plants use identical steps in
manufacturing a given metal. However, the plant need not be
discharging wastewater from the process to receive the allowance.
Thus, for example, if the regulation contains a discharge
allowance for wet scrubber effluent and a particular plant has
dry scrubbers, it cannot include a discharge allowance for wet
scrubbers as part of its aggregate limitation. On the other
hand, if it has wet scrubbers and discharges less than the
allowable limit or does not discharge from the scrubbers, it
would receive the full regulatory allowance in developing the
permit.
There are several facilities within this category that have
integrated manufacturing operations; that is, they combine
wastewater from smelting and refining operations which are part
of this point source category, with wastewater from other
manufacturing operations which are not a part of this category,
and treat the combined stream prior to discharge. For direct
dischargers, this problem would be appraoached using the building
block approach and and developing discharge allowances for the
additional wastewater streams from other applicable effluent
limitations and standards or, if such are not available, using
best professional judgment (BPJ). For indirect dischargers, this
problem would be approached by determining the discharge
allowances for the nonferrous metals manufacturing segment and
applying the combined waste formula to determine the discharge
allowand for the entire wastewater stream being treated. The
combined wastewater formula is presented in 40 CFR 403 and is
specifically intended to apply to those situations where
381
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GENERAL DEVELOPMENT DOCUMENT SECT - IX
wastewaters from various categories or non categorical
wastewaters are comingled before treatment and discharge.
Additional discussion of the development of discharge allowances
from the mixed wastewaters within this category is presented at
the end of Section X.
A summary of the BPT limitations (and also BAT, NSPS, PSES and
PSNS) is presented in Section II of each supplement.
Additionally, in each supplement, a table is presented for BPT
(also for BAT, NSPS, PSES and PSNS) showing the levels at which
all of the pollutants found at treatable levels would have been
regulated if the Agency had deemed it necessary or appropriate to
directly limit all of these pollutants. This additional
information is presented so it may be used by permit writers as
the Agency's best professional judgment whenever it becomes
necessary or desirable to set limitations on the additional
pollutants.
382
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TABLE IX-1
SUMMARY OF CURRENT TREATMENT PRACTICES
Airmonia
Stripping
Cyanide Treatment
Discharge Status
Subcategory
Lime and
Settle 1
Lime, Settle
and Filter
Oil
Skimming
Air Steam Oxidation
Ion
Precipitation Exchange
Direct
Indirect
Zero
~3
0
ft
Pri Aluminum
Smelting
11
(1)2 1
(01
24 7 31
Sec Aluminum
Smelting
2
(1)
0
<0!
10
14
23
47
Pri Copper
Smelting
3
(3)
0
(01
2
18
20
Pri Electro-
lytic Copper
Refining
5
(3)
0
(0)
1 (1)
4
11
14
Sec copper
5
(3)
2
(1!
5
6
20
31
Pri Lead
2
(0)
1
(01
4
2
0
6
Sec Lead
26
(4)
2
(li
8
26
15
49
UJ
00
Pri Zinc
4
(0)
1
(0)
3
1
4
8
w
Sec Sliver
13
(0)
2
(0)
7
26
28
61
Pri Columbium
and Tantalum
3
(0)
0
(0)
2 (0)
3
2
5
Pri Tungsten
4
(0)
0
(0)
3 (1)
4
6
6
16
Metallurgical
Acid Plants
11
(1!
2
(0)
a
2
9
19
Pri Antimony
1
l
6
7
Bauxite Refin-
ing
3
5
3
Pri Beryllium
1
1
2
3
Q
W
55
M
W
>
t"1
O
w
f
o
m
s
w
25
y-3
a
o
o
c
s
M
w
m
o
H
M
X
-------
TABLE IX-1 (Continued)
SUMMARY OF CURRENT TREATMENT PRACTICES
Ul
00
Lime arid
Settle 1
Subcategory
Pri Boron
Pri cesium
& Rubidium
Pri and Sec
Germanium and
Gallium
Sec Indium
Sec Mercury
Pri Molybdenum 3 (1}
and Rhenium
Sec Molybdenum 1
and Vanadium
Pri Nickel 1
and Cobalt
Lime, Settle
and Filter
Oil
Skimming
Sec Nickel 1
Pri Precious 1
Mtls & Mercury
Sec Precious 20
Metals
Pri Rare 1
Earth Metals
Sec Tantalum 3
11)
Ammonia
Stripping Cyanide Treatment Discharge Status
Ion
Air Steam Oxidation Precipitation Exchange Direct Indirect Zero
2
7 (1)
30
1
1
7
15
2
Total
2
1
13
1
1
2
8
49
4
Q
m
ss
M
Pd
>
17*
O
M
<
m
f
o
~D
3
M
25
H3
O
O
o
c
s
M
55
t-3
W
W
o
HI
-------
TA3LE IX-1 (Continued)
SU.MMAHY OF CURRENT TREATMENT PRACTICES
W
CO
tr1
O
M
<
M
tr1
O
3
H
Z
t-a
o
o
n
G
3
M
Z
i-3
in
M
O
1-3
H
X
-------
GENERAL DEVELOPMENT DOCUMENT SECT - IX
Table IX-2
BPT REGULATED POLLUTANT PARAMETERS
Subcategory
Primary Lead
Primary Tungsten
Pollutant Parameters
122.
128.
122.
128.
Primary Columbium-Tantalum
122.
128.
Secondary Silver
120.
128.
Secondary Lead
114.
115.
122.
128.
lead
zinc
TSS
pH
lead
zinc
ammonia (N)
TSS
pH
lead
zinc
ammonia (N)
fluoride
TSS
pH
copper
zinc
ammonia (N)
TSS
pH
antimony
arsenic
lead
zinc
ammonia (N)
TSS
PH
Primary Antimony
Primary Beryllium
114.
antimony
115.
arsenic
123.
mercury
TSS
PH
t i t
-L 1 / «
beryllium
119.
chromium
120.
copper
121.
cyanide
ammonia (,
fluoride
TSS
pH
total)
as N)
386
-------
GENERAL DEVELOPMENT DOCUMENT SECT - IX
Table IX-2 (Continued)
BPT REGULATED POLLUTANT PARAMETERS
Subcategory
Primary and Secondary Germanium
and Gallium
Primary Molybdenum and Rhenium
Secondary Molybdenum and Vanadium
Primary Nickel and Cobalt
Primary Precious Metals and Mercury
Pollutant Parameters
115. arsenic
122. lead
128. zinc
fluoride
TSS
pH
115, arsenic
122. lead
124. nickel
125. selenium
fluoride
molybdenum
ammonia {as N)
TSS
pH
115. arsenic
119. chromium
122. lead
124. nickel
molybdenum
ammonia (as N)
iron
TSS
pH
120. copper
124. nickel
cobalt
ammonia (as N)
TSS
pH
122. lead
123. mercury
126. silver
128. zinc
gold
oil and grease
TSS
pH
387
-------
GENERAL DEVELOPMENT DOCUMENT SECT - IX
Table IX-2 (Continued)
BPT REGULATED POLLUTANT PARAMETERS
Subcategory
Pollutant Parameters
Secondary Precious Metals
Primary Rare Earth Metals
Secondary Tantalum
Secondary Tin
Primary and Secondary Titanium
120. copper
121. cyanide
128. zinc
ammonia (as N)
gold
palladium
platinum
TSS
pH
119. chromium (Total)
122. lead
124. nickel
TSS
pH
120. copper
122. lead
124. nickel
128. zinc
tantalum
TSS
PH
115. arsenic
121. cyanide
12 2. 1ead
i ron
tin
fluoride
TSS
pH
119. chromium (total)
122. lead
124. nickel
titanium
oil and grease
TSS
pH
388
-------
GENERAL DEVELOPMENT DOCUMENT SECT - IX
Table IX-2 (Continued)
BPT REGULATED POLLUTANT PARAMETERS
Subcategory
Pollutant Parameters
Secondary Tungsten and Cobalt
Secondary Uranium
Primary Zirconium and Hafnium
120. copper
124. nickel
cobalt
tungsten
oil and grease
ammonia (as N)
TSS
pH
119. chromium (total;
120. copper
124. nickel
fluoride
TSS
pH
119. chromium (total;
121. cyanide (total)
122. lead
124. nickel
ammonia (as N)
TSS
pH
389
-------
GENERAL DEVELOPMENT DOCUMENT SECT -
THIS PAGE INTENTIONALLY LEFT BLANK
390
-------
GENERAL DEVELOPMENT DOCUMENT SECT - X
SECTION X
EFFLUENT QUALITY ATTAINABLE THROUGH APPLICATION OF
THE BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE
This section sets forth the effluent limitations attainable
through the application of best available technology economically
achievable (BAT). It also serves to summarize changes from
previous rulemakings in the nonferrous metals manufacturing
category, and presents the development and use of the mass-based
effluent limitations.
A number of factors guide the BAT analysis including the age of
equipment and facilities involved, the processes employed,
process changes, non-water quality environmental impacts
(including energy requirements), and the costs of application of
such technology. BAT technology represents the best available
technology economically achievable at plants of various ages,
sizes, processes, or other characteristics. BAT may include
process changes or internal controls, even when these are not
common industry practice. This level of technology also
considers those plant processes and control and treatment
technologies which, at pilot plant and other levels, have
demonstrated both technological performance and economic
viability at a level sufficient to justify investigation.
The required assessment of BAT "considers" costs, but does not
require a balancing of costs against effluent reduction benefits
(see Weyerhaeuser v. Costle, 11 ERC 2149 (D.C. Cir. 1978)). In
developing the proposed and promulgated BAT, however, EPA has
given substantial weight to the economic achievability of the
technology. The Agency has considered the volume and nature of
discharges expected after application of BAT, the general
environmental effects of the pollutants, and the costs and
economic impacts of the required pollution control levels.
The BAT effluent limitations are organized by subcategory for
individual sources of wastewater. The limitations were developed
based on the attainable effluent concentrations and production
normalized flows that have been presented in this document.
Implementation of the BAT effluent limitations is expected to
remove 1,968,000 kg/yr of priority pollutants from current
discharge. The estimated capital cost of BAT is $28.4 million
(1982 dollars), and the estimated annual cost is §22.7 million
(1982 dollars).
TECHNICAL APPROACH TO BAT
In the past, the technical approach for the nonferrous metals
manufacturing category considered each plant as a single waste-
water source, without specific regard to the different unit
processes that are used in plants within the same subcategory.
For this rulemaking, end-of-pipe treatment technologies and in-
process controls were examined in the selection of the best
391
Preceding page blank
-------
GENERAL DEVELOPMENT DOCUMENT SECT - X
available technology. After examining in-process controls, it
became apparent that it was best to establish effluent
limitations and standards recognizing specific wastewater streams
associated with specific manufacturing operations. The approach
adopted for this rule considers the individual wastewater sources
within a plant, resulting in more effective pollution abatement
by tailoring the regulation to reflect these various wastewater
sources. This approach, known as the building block approach, was
presented in Section IX. Another example to this approach is
given at the end of this section.
INDUSTRY COST AND POLLUTANT REDUCTION BENEFITS OF THE VARIOUS
TREATMENT OPTIONS
Under these guidelines, four treatment options were evaluated in
selection of BAT for the category. Because of the diverse
processes and raw materials used in the nonferrous category, the
pollutant parameters found in various waste streams are not
uniform. This required the identification of significant
pollutants in the various waste streams so that appropriate
treatment technologies could be selected for further evaluation.
The options considered applicable to the nonferrous metals
manufacturing subcategories are presented in Table X-l (page ).
A thorough discussion of the treatment technologies considered
applicable to wastewaters from the nonferrous metals
manufacturing category is presented in Section VII of this
document. In Section VII, the attainable effluent concentrations
of each technology are presented along with their uniform
applicability to all subcategories. Mass limitations developed
from these options may vary, however, because of the impact of
different production normalized wastewater discharge flows.
In summary, the treatment technologies considered for nonferrous
metals manufacturing are:
Option A is based on:
Chemical precipitation of metals followed by sedimentation, and,
where required, cyanide precipitation, sulfide precipitation,
iron co-precipitation, ammonia air or steam stripping and oil
skimming pretreatment, with ion-exchange end-of-pipe treatment.
(This option is equivalent to the technology on which BPT is
based. )
Option B is based on:
Option A (chemical precipitation and sedimentation with cyanide
precipitation, sulfide precipitation, iron co-precipitation,
ammonia air or steam stripping, and oil skimming pretreatment,
with ion exchange end-of-pipe treatment where needed) plus
process wastewater flow reduction by the following methods:
- Contact cooling water recycle through cooling towers.
- Holding tanks for all other process wastewater subject
392
-------
GENERAL DEVELOPMENT DOCUMENT SECT - X
to recycle.
Option C is based on;
Option B (chemical precipitation and sedimentation with cyanide
precipitation, sulfide precipitation, iron co-precipitation,
ammonia air or steam stripping, and oil skimming pretreatment,
with ion exchange end-of-pipe treatment where needed, preceded by
in-process flow reduction), plus multimedia filtration.
Option E is based on:
Option C (chemical precipitation, sedimentation with cyanide
precipitation, sulfide precipitation, iron co-precipitation,
ammonia air or steam stripping, and oil skimming pretreatment,
with ion exchange end-of- pipe treatment where needed, in-process
flow reduction, and multimedia filtration), plus activated carbon
adsorption applied to the total plant discharge as a polishing
step.
Two additional technologies, activated alumina and reverse
osmosis, were evaluated for this category. Activated alumina
treatment was included for reduction of fluoride and arsenic
concentrations. Reverse osmosis was considered so that complete
recycle of all process wastewater could be attained. However,
both of these technologies were rejected because they are not
demonstrated in the nonferrous metals manufacturing category, nor
are they clearly transferable. These two technologies are
discussed in greater detail in Section VII of this document.
As a means of evaluating the economic achievability of each of
these treatment options, the Agency developed estimates of the
compliance costs and pollutant reduction benefits. An estimate
of capital and annual costs for the applicable BAT options was
prepared for each subcategory as an aid in choosing the best BAT
option. The cost estimates are presented in Section X of each of
the subcategory supplements. All costs are based on March 1982
dollars.
The cost methodology has been described in detail in Section
VIII. For most treatment technologies, standard cost literature
sources were used for module capital and annual costs. Data from
several sources were combined to yield average or typical costs
as a function of flow or other characteristic design parameters.
In a small number of modules, the technical literature was
reviewed to identify the key design criteria, which were then
used as a basis for vendor contacts. The resulting costs for
individual pieces of equipment were combined to yield module
costs. In all cases, the cost data were coupled with flow data
from each plant to establish system costs for each facility.
The estimated pollutant removal that the treatment technologies
can achieve for each option for each subcategory. is presented
in Section X of each of the subcategory supplements.
393
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GENERAL DEVELOPMENT DOCUMENT SECT - X
The first step in the calculation of the removal estimates is the
calculation of production normalized raw waste values (mg/kkg)
for each pollutant in each waste stream. The raw waste values
were calculated using one of three methods. When analytical
concentration data (mg/1) and sampled production normalized flow
values (1/kkg) were available for a given waste stream,
individual raw waste values for each sample were calculated and
averaged. This method allows for the retention of any
relationship between concentration, flow and production. When
sampled production normalized flows were not available for a
given waste stream, an average concentration was calculated for
each pollutant, and the average production normalized flow taken
from the dcp information for that waste stream was used to
calculate the raw waste. When analytical values were not
available for a given waste stream, the raw waste values for a
stream of similar water quality was used.
The total flow (1/yr) for each option for each subcategory was
calculated by the following three steps: first, comparing the
actual discharge to the regulatory flow for each waste stream;
second, selecting the smaller of the two values; and third,
summing the smaller flow values for each waste stream in the
subcategory for each option. The regulatory flow values were
calculated by multiplying the total production associated with
each waste stream in each subcategory (kkg/yr) by the
appropriate production normalized flow (1/kkg) for each waste
stream for each option.
The raw waste mass values (kg/yr) for each pollutant in each
subcategory were calculated by summing individual raw waste
masses for each waste stream in the subcategory. The individual
raw waste mass values were calculated by multiplying the total
production associated with each waste stream in each subcategory
(kkg/yr) by the raw waste value (mg/kkg) for each pollutant in
each waste stream.
The mass discharged (kg/yr) for each pollutant for each option
for each subcategory was calculated by multiplying the total flow
(1/yr) for those waste streams which enter the central
pretreatment system, by the treatment effectiveness concentration
(mg/1) (Table VII-21 page xxx) for each pollutant for the
appropriate option.
The total mass removed (kg/yr) for each pollutant for each option
for each subcategory was calculated by subtracting the total mass
discharged (kg/yr) from the total raw mass (kg/yr).
Total treatment performance values for each subcategory were
calculated by using the total production (kkg/yr) of all plants
in the subcategory for each waste stream. Treatment performance
values for direct dischargers in each subcategory were calculated
by using the total production (kkg/yr) of all direct dischargers
in the subcategory for each waste stream.
MODIFICATION OF EXISTING BAT EFFLUENT LIMITATIONS
394
-------
GENERAL DEVELOPMENT DOCUMENT
SECT - X
Modifications were promulgated to all existing promulgated BAT
effluent limitations in the nonferrous metals manufacturing
category. In general, the existing BAT effluent limitations have
been modified to incorporate the building block approach. A
detailed discussion regarding the development of mass limitations
from this approach is presented in Section IX. Other
modifications to the primary lead subcategory, secondary aluminum
subcategory, primary zinc subcategory, and metallurgical acid
plants subcategory were made as a result of new information
supplied to the Agency.
To reflect the changes in stormwater allowances promulgated for
BPT in the primary copper smelting and secondary copper
subcategories, the Agency is promulgating modifications to the
stormwater allowances promulgated under BAT. The promulgated
changes allow a discharge resulting from a catastrophic
rainstorm, but they eliminate the monthly net precipitation
discharge allowance. The building block approach is not
developed for these two subcategories since they are required to
maintain zero discharge of all process wastewater pollutants.
The technology basis for BAT has been modified, in most cases to
be lime precipitation, sedimentation and filtration. Sulfide
precipitation is also included as the technology basis for the
primary lead, primary zinc, and metallurgical acid plants
subcategories and for one primary copper plant. The Agency
believes this represents the best available technology
economically achievable.
Allowances for Net Precipitation in Bauxite Refining
Promulgated BPT and BAT limitations for the bauxite refining
subcategory are based on the use of settling impoundments.
Facilities in this subcategory are subject to a zero discharge
requirement; however, during any month they can discharge a
volume of water equal to the difference between precipitation
that falls within the impoundment and evaporation from that
impoundment for that month (net precipitation).
We are promulgating minor technical amendments to delete or
correct references to FDP considerations under Part 125 and
pretreatment references to Part 128, We are not altering the
existing BAT (promulgated on April 8, 1974 under Subpart A to 40
CFR Part 421) which prohibits the discharge of process wastewater
except for an allowance for net precipitation that falls within
process wastewater impoundments.
395
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Primary Aluminum Smelting
The previous BAT effluent limitations were developed by
considering each plant as a single wastewater source and
allocating one discharge rate from which the effluent limitations
were calculated. The technology basis from which these effluent
limitations were developed are lime and settle performance
values. The modified BAT effluent limitations were developed for
individual wastewater sources identified within the primary
aluminum subcategory, and effluent concentrations attainable with
lime precipitation, sedimentation, filtration, and cyanide
precipitation. This technology is discussed in greater detail in
the BAT option selection of this section.
Secondary Aluminum Smelting
The previously promulgated BAT for this subcategory prohibited
the discharge of process wastewater. However, new information
supports the need for discharge of wastewater from chlorine
demagging, an operation considered and included in the
promulgated zero discharge regulation. Three dry processes
existed at the time of promulgation; the Durham process; the
Alcoa process; and the Teller process. The Agency believed that
each of these processes were sufficiently well demonstrated to be
installed and become operational by 1984, the compliance date for
BAT, Consequently, there was no justification for a discharge
allowance associated with this waste stream.
New information shows that the technologies are not sufficiently
demonstrated nor are they applicable to plants on a nationwide
basis. For this reason, the promulgated BAT has been modified;
the modified BAT is based on the use of wet scrubbing on chlorine
demagging operations.
Information received through comments on the 1983 proposed
regulation and through data requests shows a need for discharge
of water from ingot conveyer casting. A discharge allowance will
be provided, but is intended only for those plants that do not
practice chlorine demagging wet air pollution control. Complete
reuse of ingot conveyer casting contact cooling water in
demagging wet air scrubber operations is demonstrated.
Comments and information received in response to dcp requests
subsequent to the 1983 proposal also show the need for a
discharge allowance for wet scrubbers used in delacquering
operations, where paint and lacquers are burned from the surface
of aluminum can scrap. The promulgated BAT effluent limitations
include this waste stream, which was not considered nor included
in the 1974 BAT regulation.
Primary Electrolytic Copper Refining
The previous BAT effluent limitations were developed by
considering each plant as a single wastewater source and
allocating one discharge rate from which the effluent limitations
396
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GENERAL DEVELOPMENT DOCUMENT SECT - X
were calculated. The technology basis was lime precipitation and
sedimentation performance values. The modified BAT effluent
limitations were developed for individual wastewater sources
identified within the primary electrolytic copper refining
subcategory, and effluent concentrations attainable with lime
precipitation, sedimentation, in-process flow reduction, and
multimedia filtration. This technology is discussed in greater
detail in the BAT option selection of this section.
Primary Lead
With the exception of stormwater exemptions, the previous BAT
effluent limitations required zero discharge of all process
wastewater pollutants. Before proposing modified limitations in
1983, information supplied to the Agency showed that slag removed
from the smelting furnace may contain recoverable concentrations
of lead. For the smelter slag to be recycled back into the
production process, it must be granulated so that it is
compatible with concentrated ore. The Agency has determined that
this waste stream requires a discharge to control the build-up of
suspended solids.
However, in the final rule, EPA has moved the proposed flow
allowance for blast furnace slag granulation to dross
reverberatory slag granulation. The Agency changed this
allowance so that a plant that achieves zero discharge of blast
furnace slag granulation would not receive a discharge allowance
that is not needed.
Primary Zinc
The previous BAT effluent limitations were developed from one
wastewater discharge rate and lime and settle performance values.
The modified BAT effluent limitations were developed for
individual wastewater sources identified within the primary zinc
subcategory, and effluent concentrations attainable with lime
precipitation, sedimentation, sulfide precipitation (and
sedimentation), in-process flow reduction, and multimedia
filtration. This technology is discussed in greater detail in
the BAT option selection of this section.
Metallurgical Acid Plants
As discussed in Section IX, the metallurgical acid plants sub-
category has been modified to include acid plants associated with
primary lead and zinc smelters, and primary molybdenum roasters.
This is based on the similarity between discharge rates and
effluent characterise, ics of wastewaters from all metallurgical
acid plants. The Agency is also establishing effluent
limitations for fluoride and molybdenum in discharges from acid
plants associated with primary molybdenum operations. The
existing BAT limitations are based on the BPT technology (lime
precipitation and sedimentation), in-process wastewater
reduction, with sulfide precipitation, iron co-precipitation
preliminary treatment and filtration. Flow reductions are based
397
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GENERAL DEVELOPMENT DOCUMENT SECT - X
on 90 percent recycle of scrubber liquor.
Compliance with the BAT limitations for the metallurgical acid
plants subcategory by the two direct discharging primary
molybdenum facilities which operate sulfuric acid plants will
result in the annual removal of an estimated 4,651 kg of priority
pollutants which is 219 kg of priority pollutants greater than
the estimated BPT removed and 67,539 kg of total pollutants
including molybdenum.
The costs for this subcategory are not presented here because the
data on which they are based have been claimed to be
confidential. The Agency has determined that BAT limitations for
this subcategory are technically feasible and economically
achievable.
MODIFIED APPROACH TO STORMWATER
For the same reasons discussed in detai1 in Section IX, no
allowance will be given for stormwater under BAT. Stormwater is
or can be segregated from the process wastewater. Furthermore,
stormwater is site-specific and is best addressed on a case-by-
case basis by the permit writer. Should a sufficient number of
plants demonstrate that segregation of stormwater would result in
excessive costs or is not technically feasible, or demonstrate
that contamination of stormwater with process pollutants is an
unavoidable result of manufacturing processes, the Agency will
consider modification of the promulgated regulation as
appropriate.
The BAT regulations on catastrophic and net precipitation
exemptions are modified for several subcategories. These changes
are presented in Table X-2 (page xxx). The reasons for modifying
the BAT relief provisions for primary copper smelting, primary
copper electrolytic refining, secondary copper and primary lead
are as follows;
1. The technology basis for BAT has been changed from
wastewater impoundments to equipment such as holding
tanks, cooling towers, and clarifiers. This type of
equipment is not influenced to the same degree as
cooling impoundments. As a result, storm relief is not
necessary to treat process wastewater (with the
exception noted in (2) below).
2. For primary copper smelting and secondary copper,
impoundments to treat cooling water are used at many
facilities as an alternative to cooling towers. EPA
has thus provided that stormwater nay be discharged
from these impoundments when a 25-year, 24-hour storm
or larger has been experienced by the facility. The
volume of water that may be discharged is only that
which falls directly on the impoundment surface.
Further, since the size required for cooling water
impoundments is substantially smaller than impoundments
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GENERAL DEVELOPMENT DOCUMENT
SECT - X
that treat other process wastewaters, no net
precipitation relief is necessary. The amount of
freeboard available in the proper design and operation
of these cooling water ponds is sufficient for most
facilities to accommodate the fluctuations in volume
resulting from the precipitation cycle without having
to discharge.
BAT OPTION SELECTION
The option generally selected throughout the category is Option C
- chemical precipitation, sedimentation, in-process flow
reduction, and multimedia filtration, along with applicable
pretreatment, including ammonia air or steam stripping, cyanide
precipitation, sulfide precipitation, iron co-precipitation, and
oil skimming pretreatment, and ion exchange end-of-pipe
treatment. The Agency has selected BPT plus in-process wastewater
flow reduction and the use of filtration as an effluent polishing
step as BAT for all of the subcategories except secondary
aluminum, which includes preliminary treatment of phenolics with
activated carbon adsorption, where applicable, and primary and
secondary germanium and gallium, where BAT is based on lime and
settle,
This combination of treatment technologies has been selected
because they are technically feasible and are demonstrated within
the nonferrous metals manufacturing category. Implementation of
this treatment scheme would result in the removal of an estimated
1,968,000 kg/yr of priority pollutants from current discharge
estimates. Although the Agency is not required to balance the
costs against effluent reduction benefits (see Weyerhaeuser v.
Costle, supra), the Agency has given substantial weight to the
reasonableness of cost. The Agency's current economic analysis
shows that this combination of treatment technologies is
economically achievable. Price increases are not expected to
exceed 2.5 percent for any subcategory.
Of the 36 subcategories considered in nonferrous metals
manufacturing, EPA has reserved setting BAT limitations for the
following three subcategories;
1. Secondary Indium
2. Secondary Mercury
3. Secondary Nickel
As discussed earlier, EPA has excluded the following five sub-
categories from limitations under the provisions of Paragraph 8
of the Settlement Agreement:
1. Primary Boron
2. Primary Cesium and Rubidium
3. Primary Lithium
4. Primary Magnesium
5. Secondary Zinc
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GENERAL DEVELOPMENT DOCUMENT SECT - X
BAT Effluent limitations have been promulgated for the following
28 subcategories:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
2 2
23
24
25
26
27
28
Bauxite Refining
Primary Aluminum Smelting
Secondary Aluminum Smelting
Primary Copper Smelting
Primary Electrolytic Copper Refining
Secondary Copper
Primary Lead
Primary Zinc
Metallurgical Acid Plants
Primary Tungsten
Primary Columbium-Tantalum
Secondary Silver
Secondary Lead
Primary Antimony
Primary Beryllium
Primary and Secondary Germanium and Gallium
Primary Molybdenum and Rhenium
Secondary Molybdenum and Vanadium
Primary Nickel and Cobalt
Primary Precious Metals and Mercury
Secondary Precious Metals
Primary Rare Earth Metals
Secondary Tantalum
Secondary Tin
Primary and Secondary Titanium
Secondary Tungsten and Cobalt
Secondary Uranium
Primary Zirconium and Hafnium
The general approach taken by the Agency for BAT regulation of
this category and the BAT option selected for each subcategory is
presented in this section. The actual limitations may be found
in Section II of each subcategory suppliment.
After publication of the nonferrous metals manufacturing
regulations, some petitioners challenged the promulgated rule.
EPA developed settlement agreements based on somw of these
petitions. The results of these settlement agreements are
discussed in the pertinent subcategory supplements.
In the regulatory sections of each subcategory supplement, the
pollutants considered for regulation are included in the
regulatory tables for that subcategory. Only some of these
pollutants were selected for regulation and the regulated
pollutants are indicated with an asterisk in each table. The
pollutants found at treatable levels but not regulated are
presented to assist the permit writer by advising him of the
discharge allowance that would have been assigned if these
pollutants had been regulated.
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GENERAL DEVELOPMENT DOCUMENT
SECT - X
Primary Aluminum Smelting
The BAT option selected is flow reduction, lime precipitation,
sedimentation, and filtration for control of toxic metals and
fluoride, and cyanide precipitation preliminary treatment.
This combination of treatment technologies was selected because
it provides additional pollutant removal achievable by the
primary aluminum subcategory and it is economically achievable.
Lime precipitation and sedimentation are widely practiced at
primary aluminum plants, and as indicated in the previous
section, form the basis for the BPT limitations. Filtration
serves as an important polishing step in BAT. For this
subcategory, it results in the removal of 271,350 kg/yr of toxic
pollutants and 5,231,000 kg/yr of nonconventional pollutants from
the estimated raw discharge. Further, lime precipitation and
sedimentation are demonstrated at 11 primary aluminum smelters,
while filtration is demonstrated at 23 plants in the nonferrous
metals manufacturing category including one plant in the primary
aluminum subcategory. The estimated capital investment cost of
BAT is $16 million (1982 dollars) and the annual cost is $10.5
million.
Cyanide precipitation preliminary treatment is directed at
control of free and complexed cyanides in waste streams within
the primary aluminum subcategory that result from use of coke and
pitch in the electrolytic reduction process. These waste streams
collectively discharge approximately 62,000 kg/yr of cyanide.
The Agency conducted a pilot-scale treatment performance study
for cyanide precipitation on wastewater from a cathode
reprocessing operation, the only primary aluminum operation to
generate cyanide. The treatment effectiveness concentration for
cyanide achieved from this study is the basis for the mass
limitation. The mean was also shown, in data submitted by a
primary aluminum facility, to be achievable by ion exchange
technology applied to cyanide-contaminated groundwater. in
developing variability factors for cyanide precipitation
technology, EPA will continue to use the mean variability from
the combined metals data base because only two data points were
generated by the treatability study.
Flow reduction is an important element of BAT because it results
in reduced dilution of pollutants and smaller hydraulic flows,
which in turn lead to more efficient treatment, smaller treatment
systems, and an associated reduction in the net cost of
treatment. Wastewater flow reduction is based on increased
recycle of scrubber liquor from potline, potline S02 emissions,
pot room, and anode bake scrubbers, in addition to casting contact
cooling water.
Secondary Aluminum Smelting
The BAT effluent limitations for the secondary aluminum
subcategory are based on lime precipitation, sedimentation,
filtration, ammonia steam stripping, and activated carbon
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GENERAL DEVELOPMENT DOCUMENT SECT - X
adsorption. Ammonia steam stripping is selected by the Agency
over air stripping because air stripping reduces ammonia
concentrations by simply transferring pollutants from one media
(water) to another (air). Steam stripping reduces ammonia
concentrations by stripping the ammonia from wastewater with
steam. The ammonia is concentrated in the steam phase and may be
condensed, collected, and sold as a by-product or disposed off-
site. Ammonia steam stripping is demonstrated by five facilities
in the nonferrous metals manufacturing category. Filtration is
not demonstrated in the secondary aluminum subcategory; however,
it is demonstrated in the nonferrous metals manufacturing
category.
Activated carbon adsorption preliminary treatment to remove 4-AAP
phenols applies to plants discharging scrubber water from
delacquering furnace operations (an operation that removes paint
and other surface coatings from aluminum scrap).
Application of the promulgated BAT will result in the removal of
9,590 kg/yr of toxic pollutants, 526 kg/yr of phenols, and 90,300
kg/yr of aluminum from the estimated raw discharge. The
estimated capital investment cost of the promulgated BAT is $1.1
million (1982 dollars) and the estimated annual cost is $0.64
million.
Primary Copper Electrolytic Refining
The BAT effluent limitations for Primary Copper Electrolytic
Refining are based on in-process flow reduction and end-of-pipe
treatment technology consisting of lime precipitation,
sedimentation, and multimedia filtration. Sulfide precipitation
is added for one integrated copper refiner and smelter based on
the demonstrated inability of this plant to meet the arsenic mass
limitations with lime and settle technology. The Agency believes
that the mass limitations are achievable using sulfide
precipitation based on bench-scale performance tests using the
plant's wastewater. Filtration is not demonstrated in this
subcategory, but it is transferred from the primary aluminum,
secondary copper, primary zinc, primary lead, secondary lead, and
secondary silver subcategories.
Application of the promulgated BAT will result in the removal of
48,700 kg/yr of toxic pollutants from the estimated raw
discharge. The estimated capital investment cost of the
"promulgated BAT is $2.7 million (1982 dollars) and the estimated
annual cost is $1,7 million.
Primary Lead
The effluent limitations for the primary lead subcategory are
based on the existing BPT with additional reduction in pollutant
discharge achieved through in-process wastewater flow reduction,
sulfide precipitation technology, and the use of filtration as an
effluent polishing step. Wastewater flow reduction is based on
the complete recycle of process wastewater from zinc fuming wet
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GENERAL DEVELOPMENT DOCUMENT
SECT - X
air pollution control, blast furnace slag granulation, and hard
lead refining wet air pollution control. Extensive treatment
performance data submitted to the Agency from a well-operated
plant in this subcategory indicate that, for this facility, the
proposed BAT mass limitations are not achievable with lime,
settle and filter technology. The principal reason for not being
able to attain the proposed effluent limits is the inability to
achieve the combined metals data base lime, settle and filter
concentration values. The specific technical factors in this
failure could not be determined from the data submitted. However,
the Agency believes the addition of sulfide precipitation, in
conjunction with multimedia filtration, will achieve the
treatment effectiveness values because of the lower solubility of
metal sulfides (i.e., lower than metal hydroxides) as well as
performance data for sulfide technology obtained from treating
nonferrous metals and inorganic chemical wastewaters. Sulfide
precipitation is currently demonstrated at a primary molybdenum
plant with a metallurgical acid plant, and at a cadmium plant in
the pr imary zinc subcategory. Filtration is currently
demonstrated by one facility in the primary lead subcategory.
Application of the promulgated BAT will result in the removal of
734 kg/yr of toxic pollutants over the estimated BPT removal.
The primary lead subcategory is estimated to incur a capital cost
of $0.2 million (1982 dollars) and an annual cost of $0.11
million to implement the BAT technology.
Primary Zinc
The BAT effluent limitations for the primary zinc subcategory are
based on BPT with additional reduction in pollutant discharge
achieved through in-process wastewater flow reduction, sulfide
precipitation technology, and the use of filtration as an
effluent polishing step. Wastewater flow reduction is based on
increased recycle of casting scrubber water and casting contact
cooling water. As discussed above, sulfide precipitation and
filtration is added to ensure achievability of the combined
metals data base treatment effectiveness, concentration values for
lime, settle and filter technology. Sulfide precipitation is
currently demonstrated at a cadmium plant in the primary zinc
subcategory, and at a primary molybdenum plant with a
metallurgical acid plant. Filtration is currently in place at
one of the three direct discharging plants in the primary zinc
subcategory.
Application of the promulgated BAT effluent mass limitations will
result in the removal of 1,159,000 kg/yr of toxic pollutants from
the estimated raw discharge. The estimated capital investment
cost of the promulgated BAT is $0.46 million (1982 dollars) and
the estimated annual cost is $0.24 million. Activated alumina
and reverse osmosis were also considered for BAT but were
rejected. These technologies are not demonstrated in the
category, nor are they clearly transferable.
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Metallurgical Acid Plants
The BAT effluent limitations for metallurgical acid plants are
based on BPT with additional reduction in pollutant discharge
achieved through in-process wastewater flow reduction, sulfide
precipitation technology, and the use of filtration as an
effluent polishing step. Wastewater flow reduction is based on
increased recycle of acid plant scrubber liquor. As discussed
above, sulfide precipitation and filtration is added to ensure
achievability of the combined metals data base treatment
effectiveness concentration values for lime, settle and filter
technology. Sulfide precipitation is currently demonstrated at a
cadmium plant in the primary zinc subcategory, and at a primary
molybdenum plant with a metallurgical acid plant. Filtration is
currently demonstrated at two of the seven direct discharging
plants in the metallurgical acid plants subcategory.
Application of the promulgated BAT mass limitations will result
in the removal of 136,800 kg/yr of toxic pollutants from the
estimated raw discharge. The estimated capital investment cost
of BAT is $1.97 million (1982 dollars) and the annual cost is
$1.24 million.
Filtration, option C, was selected instead of option B because it
is demonstrated and results in removal of 7,590 kg/yr of toxic
pollutants,
Primary Tungsten
The BAT limitations for the primary tungsten subcategory are
based on BPT with additional reduction in pollutant discharge
achieved through in-process wastewater flow reduction and the use
of filtration as an effluent polishing step. Wastewater flow
reduction is based on 90 percent recycle of scrubber liquors.
Filtration is currently demonstrated at 23 plants in the
category.
Application of the promulgated BAT will remove an estimated 5,140
kg/yr of toxic pollutants, which is 318 kg/yr of toxic metals
over the estimated BPT removal. No additional ammonia is removed
at BAT, nor are any toxic organics removed. The estimated
capital investment cost of BAT is $0.77 million (1982 dollars)
and the estimated annual cost is $1.0 million.
Primary Columbiurn-Tantalum
The BAT limitations for the primary columbium-tantalum
subcategory are based on BPT with additional reduction in
pollutant discharge achieved through in-process wastewater flow
reduction and the use of filtration as an effluent polishing
step. Wastewater flow reduction is based on increased recycle of
scrubber liquors associated with three sources: concentrate
digestion scrubber, solvent extraction scrubber, and
precipitation scrubber. Filtration is currently demonstrated at
23 nonferrous metals manufacturing plants.
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Application of the promulgated BAT will result in the removal of
283 kg/yr of toxic pollutants and 1,980 kg/yr of nonconventional
pollutants over the estimated BPT removal. The estimated capital
investment cost of BAT is $0.83 million (1982 dollars) and the
estimated annual cost is $1.2 million.
Filtration, option C, was selected instead of option B because it
is demonstrated and results in removal of 57 kg/yr of toxic
pollutants and 94 kg/yr of nonconventional pollutants.
Secondary Silver
The BAT limitations for the secondary silver subcategory are
based on BPT with additional reduction in pollutant discharge
through in-process wastewater flow reduction and the use of
filtration as an effluent polishing step. Wastewater flow
reduction is based on complete recycle of furnace scrubber water.
Filtration is currently demonstrated at two of the seven direct
discharging secondary silver plants.
Application of the promulgated BAT will result in the removal of
132 kg/yr of toxic pollutants over the estimated BPT removal.
The estimated capital investment cost of the promulgated BAT is
$0.28 million (1982 dollars) and the annual cost is $0.39
million.
Filtration, option C, was selected instead of option B because it
is demonstrated and results in removal of 132 kg/yr of toxic
pollutants.
Secondary Lead
The BAT limitations for the secondary lead subcategory are based
on BPT with additional reduction in pollutant discharge through
in-process wastewater flow reduction and the use of filtration as
an effluent polishing step. Wastewater flow reduction is based
on 90 percent recycle of casting contact cooling water and
complete recycle of facility washdown water and battery case
classification wastewater. Filtration is currently demonstrated
at one of eight direct discharging secondary lead plants and
seven plants in this subcategory.
Application of the promulgated BAT will result in the removal of
350 kg/yr of toxic pollutants over the estimated BPT removal.
The estimated capital investment cost of this technology is $1.86
million, (1982 dollars) and the estimated annual cost is $1.24
million.
Primary Antimony
The BAT limitations for the primary antimony subcategory are
based on chemical precipitation and sedimentation and sulfide
precipitation preliminary treatment (BPT technology) with the
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GENERAL DEVELOPMENT DOCUMENT SECT - X
addition of filtration.
The pollutants specifically limited under BAT are antimony,
arsenic, and mercury. The priority pollutants cadmium, copper,
lead, and zinc were also considered for regulation because they
were found at treatable concentrations in the raw wastewaters
from this subcategory. These pollutants were not selected for
specific regulation because they will be effectively controlled
when the regulated priority metals are treated to the levels
achievable by the model BAT technology.
Implementation of the BAT limitations would remove annually an
estimated 18 kg of priority metals over the estimated BPT
discharge. Estimated capital cost for achieving BAT is $208,300,
and annualized cost is $560,400.
Primary Beryllium
The BAT limitations for the primary beryllium subcategory are
based on chemical precipitation and sedimentation preceded by
scrubber liquor recycle, ammonia steam stripping and cyanide
precipitation (BPT technology), with the addition of filtration
and scrubber water recycle. Flow reduction is based on greater
than 90 percent recycle of beryllium oxide calcining furnace wet
air pollution control. The one beryllium plant currently
generating beryllium oxide calcining furnace wet air pollution
control wastewater does practice recycle.
The pollutants specifically limited under BAT are beryllium,
chromium, copper, cyanide, ammonia, and fluoride.
Implementation of the BAT limitations would remove annually an
estimated 8 kg of priority metals and 0.5 kg of cyanide over the
estimated BPT discharge. No additional ammonia is removed.
The costs and specific removal data for this subcategory are not
presented here because the data on which they are based has been
claimed to be confidential.
Primary and Secondary Germanium and Gallium
The BAT limitations for the primary and secondary germanium and
gallium subcategory are based on chemical precipitation and
sedimentation (BPT technology).
The pollutants specifically limited under BAT are arsenic, lead,
zinc, and fluoride. The priority pollutants antimony, cadmium,
chromium, copper, nickel, selenium, silver and thallium were also
considered for regulation because they were found at treatable
concentrations in the raw wastewaters from this subcategory.
These pollutants were not selected for specific regulation
because they will be effectively controlled when the regulated
priority metals are treated to the concentrations achievable by
the model : BAT technology. EPA is including limitations for
gallium and germanium as guidance for permitting authorities.
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Although there are no existing direct dischargers in this
subcategory, BAT is promulgated for any existing zero discharger
who elects to discharge at some point in the future. This action
was necessary because wastewaters from germanium and gallium
operations which contain significant loadings of priority
pollutants are currently being disposed of in a RCRA permitted
surface impoundment.
The costs and specific removal data for this subcategory are not
presented here because the data on which they are based has been
claimed to be confidential.
Primary Molybdenum and Rhenium
The BAT limitations for the primary molybdenum and rhenium
subcategory are based on preliminary treatment consisting to
ammonia steam stripping, iron co-precipitation, and end-of-pipe
treatment consisting of chemical precipitation and sedimentation
(BPT technology), with the addition of in-process wastewater flow
reduction and filtration. Flow reductions are based on 90
percent recycle of scrubber liquor, a rate demonstrated by one of
the two direct discharger plants.
The pollutants specifically limited under BAT are arsenic, lead,
molybdenum, nickel, selenium, fluoride, and ammonia. The
priority pollutants chromium, copper, and zinc were also
considered for regulation because they were found at treatable
concentrations in the raw wastewaters from this subcategory.
These pollutants were not selected for specific regulation
because they will be effectively controlled when the regulated
priority metals are treated to the levels achievable by the model
BAT technology.
Implementation of the BAT limitations would remove annually an
estimated 11 kg of priority metals greater than the estimated BPT
removal. No additional ammonia is removed at BAT.
The costs and specific removal data for this subcategory are not
presented here because the data on which they are based has been
claimed to be confidential.
Secondary Molybdenum and Vanadium
.. ¦¦¦¦¦¦ -A. + _____ .
The BAT limitations for the secondary molybdenum and vanadium
subcategory are based-on preliminary treatment consisting of
ammonia air stripping followed by end-of-pipe treatment
consisting of iron co-precipitation, chemical precipitation and
sedimentation (BPT technology) and filtration.
The pollutants specifically limited under BAT are arsenic,
chromium, lead, molybdenum, nickel, iron, and ammonia. The
priority pollutants antimony, beryllium, cadmium, and zinc were
also considered for regulation because they were found at
treatable concentrations in the raw wastewaters from this
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GENERAL DEVELOPMENT DOCUMENT SECT - X
subcategory. These pollutants were not selected for specific
regulation because they will be effectively controlled when the
regulated priority metals are treated to the concentrations
achievable by the model BAT technology. EPA is providing
limitations for the following pollutants as guidance for
permitting authorities; copper, zinc, aluminum, boron, cobalt,
germanium, manganese, tin, titanium, and vanadium.
Implementation of the BAT limitations would remove annually an
estimated 76 kg of priority metals greater than the estimated BPT
removal.
The costs and specific removal data for this subcategory are not
presented here because the data on which they are based has been
claimed to be confidential.
Primary Nickel and Cobalt
The BAT limitations for the primary nickel and cobalt subcategory
are based on preliminary treatment consisting of ammonia steam
stripping followed by end-of-pipe treatment consisting of
chemical precipitation and sedimentation (BPT technology), and
filtration. A filter is presently utilized by the one plant in
this subcategory.
The pollutants specifically limited under BAT are cobalt, copper,
nickel, and ammonia. The priority pollutant zinc was also
considered for regulation because it was found at treatable
concentrations in the raw wastewaters from this subcategory.
This pollutant was not selected for specific regulation because
it will be effectively controlled when the regulated priority
metals are treated to the levels achievable by the model BAT
technology.
Implementation of the BAT limitations would remove annually an
estimated 5 kg of toxic metals greater than the estimated BPT
removal.
The costs and specific removal data for this subcategory are not
presented here because the data on which they are based has been
claimed to be confidential.
Primary Precious Metals and Mercury
The BAT limitations for the primary precious metals and mercury
subcategory are based on preliminary treatment consisting of oil
skimming and end-of-pipe treatment consisting of chemical
precipitation and sedimentation (BPT technology), with the
addition of in-process wastewater flow reduction, filtration and
ion-exchange.
The pollutants specifically limited under BAT are gold, lead,
mercury, silver, and zinc. The priority pollutants arsenic,
cadmium, chromium, copper, nickel and thallium were also
considered for regulation because they were found at treatable
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GENERAL DEVELOPMENT DOCUMENT SECT - X
concentrations in the raw wastewaters from this subcategory.
These pollutants were not selected for specific regulation
because they will be effectively controlled when the regulated
priority metals are treated to the levels achievable by the model
BAT technology.
Implementation of the BAT limitations would remove annually an
estimated 1.0 kg of priority metals greater than the estimated
BPT removal. Estimated capital cost for achieving BAT is $3,025,
and annualized cost is $27,300.
Secondary Precious Metals
The BAT limitations for the secondary precious metals subcategory
are based on preliminary treatment consisting of cyanide
precipitation and ammonia steam stripping and end-of-pipe
treatment consisting of chemical precipitation and sedimentation
(BPT technology), with the addition of in-process wastewater flow
reduction, filtration and ion exchange. Flow reductions are
based on recycle of scrubber effluent. Twenty-one of the 29
existing plants currently have scrubber liquor recycle rates of
90 percent or greater. A filter is also presently utilized by
one plant in the subcategory.
The pollutants specifically limited under BAT are copper,
cyanide, zinc, ammonia, gold, palladium, and platinum. The
priority pollutants antimony, arsenic, cadmium, chromium, lead,
nickel, selenium, silver and thallium were also considered for
regulation because they were found at treatable concentrations in
the raw wastewaters from this subcategory. These pollutants were
not selected for specific regulation because they will be
effectively controlled when the regulated priority metals are
treated to the levels achievable by the model BAT technology.
Implementation to the BAT limitations would remove annually an
estimated 10 kg of priority pollutants greater than the estimated
BPT removal. No additional ammonia or cyanide is removed at BAT.
The costs and specific removal data for this subcategory are not
presented here because the data on which they are based has been
claimed to be confidential.
Primary Rare Earth Metals
The BAT limitations that were promulgated for the primary rare
earth metals subcategory on September 20, 1985 have been
withdrawn. These limitations were withdrawn because EPA failed
to adequately address the sole plant's comments in the
Administrative Record. Therefore, national BAT limitations are
not available for this subcategory, and a rare earth metal
manufacturing plant's effluent limitations will need to be
developed by the local permitting authority through the NPDES
program.
Secondary Tantalum
409
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GENERAL DEVELOPMENT DOCUMENT SECT - X
The BAT limitations for the secondary tantalum subcategory are
based on chemical precipitation and sedimentation (BPT
technology) with the addition of filtration.
The pollutants specifically limited under BAT are copper, lead,
nickel, zinc, and tantalum. The priority pollutants antimony,
beryllium, cadmium, chromium, and silver were also considered for
regulation because they were found at treatable concentrations in
the raw wastewaters from this subcategory. These pollutants were
not selected for specific regulation because they will be
effectively controlled when the suggested priority metals are
treated to the levels achievable by the model BAT technology.
Implementation of the BAT limitations would remove annually an
estimated 4.8 kg of metal priority pollutants more than the
estimated BPT removal.
The costs and specific removal data for this subcategory are not
presented here because the data on which they are based has been
claimed to be confidential.
Secondary Tin
The BAT limitations for the secondary tin subcategory are based
on preliminary treatment consisting of cyanide precipitation when
required, and end-of-pipe treatment consisting of chemical
precipitation and sedimentation (BPT technology), with the
addition of filtration.
The pollutants specifically limited under BAT are arsenic,
cyanide, lead, iron, tin, and fluoride. The priority pollutants
antimony, cadmium, chromium, copper, nickel, selenium, silver,
thallium, and zinc were also considered for regulation because
they were found at treatable concentrations in the raw waste-
waters from this subcategory. These pollutants were not selected
for specific regulation because they will be effectively
controlled when the regulated priority metals are treated to the
levels achievable by the model BAT technology.
Implementation to the BAT limitations would remove annually an
estimated 26 kg of priority metals over the estimated BPT
discharge. An additional 128 kg of fluoride is removed annually
at BAT. The costs and specific removal data for this subcategory
are not presented here because the data on which they are based
has been claimed to be confidential.
Primary and Secondary Titanium
EPA is exempting from limitations those titanium plants which do
not practice electrolytic recovery of magnesium and which use
vacuum distillation instead of leaching to purify titanium
sponge. BAT limitations are promulgated for all other titanium
plants based on chemical precipitation, sedimentation, and oil
skimming pretreatment where required (BPT technology), plus flow
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GENERAL DEVELOPMENT DOCUMENT SECT - X
reduction and filtration. Flow reduction is based on 90 percent
recycle of scrubber effluent through holding tanks and 90 percent
recycle of casting contact cooling water through cooling towers.
The pollutants specifically limited under BAT are chromium, lead,
nickel, and titanium. The priority pollutants antimony, cadmium,
copper, thallium, and zinc were also considered for regulation
because they were found at treatable concentrations in the raw
wastewaters from this subcategory. These pollutants were not
selected for specific regulation because they will be effectively
controlled when the regulated priority metals are treated to the
levels achievable by the model BAT technology.
Implementation of the BAT limitations would remove annually an
estimated 299 kg to priority pollutants from the current
discharge. Estimated capital cost for achieving BAT is
$1,030,000, and annualized cost is $585,000.
Secondary Tungsten and Cobalt
The BAT limitations for the secondary tungsten and cobalt
subcategory are based on preliminary treatment consisting of
ammonia steam stripping and oil skimming, and end-of-pipe
treatment consisting of chemical precipitation and sedimentation
(BPT technology), plus filtration.
The pollutants specifically limited under BAT are cobalt, copper,
nickel, tungsten, and ammonia. The priority pollutants arsenic,
cadmium, chromium, lead, silver, and zinc were also considered
for regulation because they were found at treatable
concentrations in the raw wastewaters from this subcategory.
These pollutants were not selected for specific regulation
because they will be effectively controlled when the regulated
priority metals are treated to the levels achievable by the model
BAT technology.
Implementation of the BAT limitations would remove annually an
estimated 100 kg of priority, pollutants more than estimated BPT
removal.
The costs and specific removal data for this subcategory are not
presented here because the data on which they are based has been
claimed to be confidential.
Secondary Uranium
The BAT limitations for the secondary uranium subcategory are
based on end-of-pipe treatment consisting of chemical
precipitation and sedimentation (BPT technology), and filtration.
Flow reduction of laundry wastewater is included in BAT.
The pollutants specifically limited under BAT are chromium,
copper, nickel, and fluoride. The priority pollutants antimony,
arsenic, cadmium, lead, selenium, silver, zinc, and the
nonconventional pollutant uranium were also considered for
411
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GENERAL DEVELOPMENT DOCUMENT SECT - X
regulation because they were found at treatable concentrations in
the raw wastewaters from the subcategory. These pollutants were
not selected for specific regulation because they will be
effectively controlled when the regulated priority metals are
treated to the levels achievable by the model BAT technology.
Guidance is being provided to permit writers for the control of
uranium.
Implementation of the BAT limitations would remove annually an
estimated 126 kg of priority metals from the current discharge.
Estimated capital cost for achieving BAT is $88,000, and
annualized cost is $107,000 (1982 dollars).
Primary Zirconium and Hafnium
EPA is exempting from limitations those plants which only produce
zirconium or zirconium-nickel alloys by magnesium reduction of
Zr02« Limitations apply to all other plants in the subcategory.
BAT limitations are based on the same flow allowances provided at
BPT (cyanide precipitation, ammonia steam stripping and chemical
precipitation and sedimentation), plus in-process wastewater flow
reduction and filtration.
The pollutants specifically limited under BAT are chromium,
cyanide, lead, nickel, and ammonia. The priority pollutants
cadmium, thallium, zinc, and the nonconventional pollutants
zirconium and hafnium were also considered for regulation because
they were found at treatable concentrations in the raw waste-
waters from this subcategory. These pollutants were not selected
for specific regulation because they will be effectively con-
trolled when the regulated priority metals are treated to the
levels achievable by the model BAT technology.
The costs and specific removal data for this subcategory are not
presented here because the data on which they are based has been
claimed to be confidential.
REGULATED POLLUTANT PARAMETERS
Presented in Section VI of this document is a list of the
pollutant parameters found at concentrations and frequencies
above treatable concentrations that warrant further
consideration. Although these pollutants were found at treatable
concentrations, the Agency is not promulgating regulation of each
pollutant selected for further consideration. The high cost
associated with analysis of metal priority pollutants has
prompted EPA to develop an alternative method for regulating and
monitoring toxic pollutant discharges from the nonferrous metals
manufacturing category. Rather than developing specific effluent
mass limitations and standards for each of the priority metals
found in treatable concentrations in the raw wastewater from a
given subcategory, the Agency is promulgating effluent mass
limitations only for those pollutants generated in the greatest
quantities as shown by the pollutant reduction benefit analysis.
412
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GENERAL DEVELOPMENT DOCUMENT SECT - X
By establishing limitations and standards for certain metal
pollutants, dischargers will attain the same degree of control
over metal pollutants as they would have been required to achieve
had all the metal pollutants been directly limited. This
approach is technically justified since the treatable
concentrations achievable with chemical precipitation and
sedimentation technology are based on optimized treatment for
concomitant multiple metals removal. Thus, even though metals
have somewhat different theoretical solubilities, they will be
removed at very nearly the same rate in a chemical precipitation
and sedimentation treatment system operated for multiple metals
removal. Filtration as part of the technology basis is likewise
justified because this technology removes metals non-
preferentially.
The Agency has excluded several toxic organic pollutants from
specific regulation in the primary tungsten, primary columbium-
tantalum, and secondary silver subcategories because they were
found in trace (deminimus quantities) amounts and are neither
causing nor likely to cause toxic effects.
The conventional pollutants oil and grease, pH, and TSS are
excluded from regulation in BAT. They are regulated by BCT,
Table X-2 (page 416) presents the pollutants selected for
specific regulation in BAT and Table X-3 (page 419) presents
those pollutants that are effectively controlled by technologies
upon which are based other effluent limitations and guidelines.
Table X-4 (page 424) presents those pollutants excluded because
they are neither causing nor likely to cause toxic effects. A
more detailed discussion on the selection and exclusion of
priority pollutants is presented in Sections VI and X of each
subcategory supplement.
EXAMPLE OF THE BUILDING BLOCK APPROACH IN DEVELOPING PERMITS
That there is a wide range of differences in manufacturing
facilities has been emphasized by industry representatives and
observed by Agency personnel. This diversity of processes makes
it virtually impossible to establish effluent limitations and
standards on a whole plant basis such that they are fair and
achievable for industry and protective of the environment. To
better accomplish these seemingly mutually exclusive goals, the
Agency has adopted the building block approach to developing
discharge limits for use in water discharge permits. The building
block approach allows the permit writer to establish appropriate
and achievable effluent limits for any discharge point by
combining appropriate limitations based upon the various
processes that contribute wastewater to the discharge point.
Each building block represents a single process or discharge
stream from a process within the subcategory. Because of
differences in manufacturing processes, all building blocks will
not occur in every plant in a subcategory. Similarly, the amount
of material processed through any building block may vary from
plant to plant both because of the product output of the plant
413
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GENERAL DEVELOPMENT DOCUMENT SECT - X
and the manufacturing processes used. The building block approach
takes both of these variables into account; the first by allowing
the selection of only those building blocks that are in use and
the second by relating the quantity of pollutant allowed to be
discharged to the materials processed or produced by a building
block. This measure of production is called a production
normalizing parameter (PNP) and is specific to each building
block.
As a simplified example, consider a facility which produces
aluminum from bauxite and treats the wastewater prior to
discharge. The facility in this example discharges wastewater
from pot room wet air pollution control and direct chill casting.
Only a part of the aluminum reduced in the potroom is processed
through the direct chill casting operation; the remainder is cast
into sow molds and generates no process wastewater. By
multiplying the production for each of these operations by the
limitations or standards in 40 CFR 421 for potroom wet air
pollution control and direct chill casting and by summing the
products obtained for each of these waste streams, the permit
writer can obtain the allowable mass discharge.
The permit writer must develop a quantification of the PNP for
each building block so that it is a reasonable representation of
the actual production level of the building block. The factors to
be taken into account in this quantification and the procedures
for calculating the reasonable representation of the actual
production have been reviewed in the development of 40 CFR 126.
The permit writer is expected to take into account production
variations in establishing a reasonable measure of the actual
production for use in the calculation of the discharge allowance.
If, for example, the reasonable representation of the actual
production associated with the potroom wet air pollution control
system is 550 kkg/day and the reasonable representation of the
production of aluminum through direct chill casting is 410
kkg/day the maximum for any one day discharge limit based on the
best available technology economically achievable (BAT) for the
pollutant nickel is 0.72486 kg/day as calculated below:
Potroom Wet Air Pollution Control
(550 kkg/day) x (0.733 mg/kg) x (10~^mg/kg)
= 0.42515 kg nickel, maximum for any one day
Direct Chill Casting
(410 kkg/day) x (0,731 mg/kg) x (10-3mg/kg)
= 0.29971 kg nickel, maximum for any one day
Total = 0.72486 kg nickel, maximum for any one day
414
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Table X-l
OPTIONS CONSIDERED FOR EACH OF THE NONFERROUS
METALS MANUFACTURING SUBCATEGORIES
Subcategory
A
1
c
E
Primary Aluminum Smelting
X
X
X
X
Secondary Aluminum Smelting
X
X
X
Primary Copper Electrolytic
X
X
X
Primary Zinc
X
X
X
Primary Lead
X
X
X
Metallurgical Acid Plants
X
X
X
Primary Tungsten
X
X
X
Primary Columbiurn-Tantalum
X
X
X
Secondary Silver
X
X
X
Secondary Lead
X
X
X
Primary Antimony
X
"1
X
Primary Beryllium
X1
X
Primary and Secondary
X
X
Germanium and Gallium
Secondary Indium
X
X
Secondary Mercury
X
X
Primary Molybdenum and
X
X
X
Rhenium
Secondary Molybdenum and
X
X
Vanadium
Primary Nickel and Cobalt
X
X
Secondary Nickel
X
X
Primary Precious Metals and
X
X
X
Mercury
Secondary Precious Metals
X
X
X
Primary Rare Earth Metals
X
X
X
Secondary Tantalum
X.
X
Secondary Tin
X1
X
Primary and Secondary Titanium
X
X
X
Secondary Tungsten and Cobalt
X
X
Secondary Uranium
X,
X
Primary Zirconium and Hafnium
X1
X
Includes recycle of scrubber liquors
as part
of I
415
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Table X-2
BAT REGULATED POLLUTANT PARAMETERS
Subcategory
Primary Aluminum Smelting
Secondary Aluminum
Primary Electrolytic Copper
Refining
Primary Lead
Primary Zinc
Metallurgical Acid Plants
Primary Tungsten
Primary Columbium-Tantalum
Secondary Silver
Pollutant Parameters
73. benzo(a)pyrene
114. antimony
121. cyanide (total)
124. nickel
aluminum
fluoride
122. lead
128. zinc
aluminum
ammonia (N)
phenolics
(total; by
4-AAP method)
114. arsenic
120. copper
124. nickel
122. lead
128. zinc
118. cadmium
120. copper
122. lead
128. zinc
115. arsenic
118. cadmium
120. copper
122. lead
128. zinc
122. lead
128. zinc
ammonia (N)
122. lead
128. zinc
ammonia (N)
fluoride
120,
128,
copper
zinc
ammonia
(N)
416
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Table X-2 (Continued)
BAT REGULATED POLLUTANT PARAMETERS
Subcategory Pollutant Parameters
Secondary Lead
114.
antimony
115.
arsenic
122.
lead
128.
zinc
ammonia (N)
Primary Antimony
114.
antimony
115.
arsenic
123.
mercury
Primary Beryllium
117.
beryllium
119.
chromium (total
120.
copper
121.
cyanide
ammonia (as N)
fluoride
Primary and Secondary Germanium
115.
arsenic
and Gallium
122.
lead
128.
zinc
fluor ide
Primary Molybdenum and Rhenium
115.
arsenic
122.
lead
124.
nickel
125.
selenium
fluor ide
molybdenum
ammonia (as N)
Secondary Molybdenum and Vanadium
115.
arsenic
119.
chromium
122.
lead
124.
nickel
molybdenum
ammonia (as N)
iron
Primary Nickel and Cobalt
120 .
copper
124 .
nickel
cobalt
ammonia (as N)
Primary Precious Metals and Mercury
122.
lead
123.
mercury
126.
silver
128.
zinc
gold
417
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Table X-2 (Continued)
BAT REGULATED POLLUTANT PARAMETERS
Subcategory
Secondary Precious Metals
Pollutant Parameters
Primary Rare Earth Metals
Secondary Tantalum
Secondary Tin
Primary and Secondary Titanium
Secondary Tungsten and Cobalt
Secondary Uranium
Primary Zirconium and Hafnium
120.
121.
128.
9.
119.
122.
124.
120.
122.
124.
128.
115.
121.
122.
119,
122,
124,
120
124
119
120,
124 ,
119,
121,
122,
124,
copper
cyanide
zinc
ammonia (as N)
gold
palladium
platinum
hexachlorobenzene
chromium (total)
lead
nickel
copper
lead
nickel
zinc
tantalum
arsenic
cyanide
lead
i ron
tin
fluoride
chromium (total)
lead
nickel
titanium
copper
nickel
cobalt
tungsten
ammonia (as N)
chromium
copper
nickel
t'luor ide
chromium
cyanide (
lead
nickel
ammonia (
(total)
(total
total)
as N)
418
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Table X-3
PRIORITY POLLUTANTS EFFECTIVELY CONTROLLED BY TECHNOLOGIES UPON
WHICH ARE BASED OTHER EFFLUENT LIMITATIONS AND GUIDELINES
Subcategory
Primary Aluminum Smelting
Pollutant Parameters
1. acenaphthene
39. fluoranthene
55. naphthalene
72. benzo{a)anthracene
(1,2-benzanthracene)
76, chrysene
78. anthracene (a)
79. benzo(ghi)perylene
(1,11-benzoperylene)
80. fluorene
81. phenanthrene (a)
82. dibenzo(a,h)anthracene
(1,2,5,6-dibenzanthracene)
84. pyrene
115. arsenic
116. asbestos (Fibrous)
118. cadmium
119. chromium (Total)
120. copper
122. lead
125. selenium
128. zinc
(a) Reported together.
Secondary Aluminum
65. phenol
118. cadmium
Primary Electrolytic
Copper Refining
119. chromium (Total)
122. lead
126. silver
128. zinc
Primary Lead
116. asbestos (Fibrous)
118. cadmium
Primary Zinc
115. arsenic
116. asbestos (Fibrous)
119. chromium (Total)
124. nickel
126. silver
419
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Table X-3 (Continued)
TOXIC POLLUTANTS EFFECTIVELY CONTROLLED BY TECHNOLOGIES
UPON WHICH ARE BASED OTHER EFFLUENT LIMITATIONS AND GUIDELINES
Subcategory
Metallurgical Acid Plants
Primary Tungsten
Primary Columbium-Tantalum
Secondary Silver
Secondary Lead
Primary Antimony
Pollutants
114.
antimony
119.
chromium
123.
mercury
124.
nickel
125.
selenium
126.
silver
118.
cadmium
119.
chromium
124.
nickel
125.
silver
127.
thallium
114.
antimony
115.
arsenic
116.
asbestos
118.
cadmium
119.
chromium
120.
copper
124.
nickel
125.
selenium
127.
thallium
114.
antimony
115.
arsenic
118.
cadmium
119 .
chromium
121.
cyanide
122.
lead
124 .
nickel
125.
selenium
126.
silver
127 .
thallium
118.
cadmium
119.
chromium
120.
copper
124.
nickel
126.
silver
127 .
thallium
118.
cadmium
120 .
copper
128.
z i.nc
Total)
420
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Table X-3 (Continued)
TOXIC POLLUTANTS EFFECTIVELY CONTROLLED BY TECHNOLOGIES
UPON WHICH ARE BASED OTHER EFFLUENT LIMITATIONS AND GUIDELINES
Subcategory
Pollutants
Primary and Secondary Germanium 114. antimony
and Gallium 118. cadmium
119. chromium
120. copper
124. nickel
125. selenium
126. silver
127. thallium
Primary Molybdenum and Rhenium
119. chromium (total)
120. copper
128. zinc
Secondary Molybdenum and
Vanadium
114.
117.
118.
128.
antimony
beryllium
cadmium
zinc
Primary Nickel and Cobalt
Primary Precious Metals and
Mercury
128. zinc
115.
118.
119.
120.
124.
127 .
arsenic
cadmium
chromium
copper
nickel
thallium
Secondary Precious Metals
114.
115.
118 .
119.
122.
124.
125.
126.
127.
antimony
arsenic
cadmium
chromium
lead
nickel
selenium
silver
thallium
421
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Table X-3 (Continued)
PRIORITY POLLUTANTS EFFECTIVELY CONTROLLED BY TECHNOLOGIES UPON
WHICH OTHER EFFLUENT LIMITATIONS AND GUIDELINES ARE BASED
Subcategory
Primary Rare Earth Metals
Pollutant Parameters
Secondary Tantalum
Secondary Tin
Primary and Secondary
Titanium
Secondary Tungsten and
Cobalt
4.
benzene
115.
arsenic
.
cadmium
120.
copper
125.
selenium
126.
silver
127.
thallium
128.
zinc
114.
antimony
117.
beryllium
118.
cadmium
119.
chromium
126.
silver
114.
antimony
118.
cadmium
119.
chromium
120.
copper
124.
nickel
125.
selenium
126.
silver
127.
thallium
128.
zinc
114.
antimony
118.
cadmium
120.
copper
128.
zinc
115.
arsenic
118.
cadmium
119.
chromium
124.
lead
126.
silver
128.
zinc
total)
422
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Table X-3 (Continued)
PRIORITY POLLUTANTS EFFECTIVELY CONTROLLED BY TECHNOLOGIES UPON
WHICH OTHER EFFLUENT LIMITATIONS AND GUIDELINES ARE BASED
Subcategory
Secondary Uranium
Pollutant Parameters
114. antimony
115. arsenic
118. cadmium
122. lead
125. selenium
126. silver
128. zinc
Primary Zirconium and Hafnium 118. cadmium
127. thallium
128. zinc
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GENERAL DEVELOPMENT DOCUMENT SECT - X
Table X-4
TOXIC POLLUTANTS DETECTED BUT ONLY IN TRACE AMOUNTS
AND ARE NEITHER CAUSING NOR LIKELY TO CAUSE TOXIC EFFECTS
Subcategory
Primary Tungsten
Primary Columbium-Tantalum
Secondary Silver
Pollutants
11.
1,1,1-trichloroethane
55.
naphthalene
65.
phenol
73.
benzo{a)pyrene
79,
benzo(ghi)perylene
82.
dibenzo(a,h)anthracene
85.
tetrachloroethylene
86.
toluene
4.
benzene
6.
carbon tetrachloride
7.
chlorobenzene
8.
1,2,4-trichlorobenzene
10.
1,2-dichloroethane
30.
1,2-trans-dichloroethylene
38.
ethylbenzene
51.
chlorodibromomethane
85.
tetrachloroethylene
87 .
trichloroethylene
4.
benzene
6.
carbon tetrachloride
{tetrachloroemethane)
10.
1,2-dichloroethane
11.
1,1,1-trichloroethane
29.
1,1-dichloroethylene
30.
1, 2-trans-dichloroethylene
38.
ethylbenzene
84.
pyrene
85.
tetrachloroethylene
86.
toluene
87.
trichloroethylene
total phenolics (by 4-AAP
method)
424
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GENERAL DEVELOPMENT DOCUMENT SECT - XI
SECTION XI
NEW SOURCE PERFORMANCE STANDARDS
The basis for new source performance standards (NSPS) under
Section 306 of the Clean Water Act is the best available
demonstrated technology (BDT). New plants have the opportunity
to design the best and most efficient production processes and
wastewater treatment technologies. Therefore, NSPS includes
process changes, in-plant controls (including elimination to
wastewater discharges for some streams), operating procedure
changes, and end-of-pipe treatment technologies to reduce
pollution to the maximum extent possible. This section describes
the control technology for treatment of wastewater from new
sources and presents mass discharge limitations of regulated
pollutants for NSPS, based on the described control technology.
TECHNICAL APPROACH TO NSPS
All wastewater treatment technologies applicable to a new source
in the nonferrous metals manufacturing category have been
considered previously for the BAT options. For this reason, four
options were considered as the basis for NSPS, all identical to
BAT options in Section X. In summary, the treatment technologies
considered for nonferrous metals manufacturing new facilities are
outlined below:
Option A is based on:
Chemical precipitation of metals followed by sedimentation,
and, where required, ion exchange, sulfide precipitation,
iron co-precipitation, cyanide precipitation, ammonia air or
steam stripping, and oil skimming.
Option B is based on:
Option A plus process wastewater flow reduction by the
following methods:
Contact cooling water recycle through cooling
towers.
Holding tanks for all other process wastewater
subject to recycle.
Option C is based on:
Option B plus multimedia filtration.
Option E is based on:
Option C plus activated carbon adsorption applied to the
total plant discharge as a polishing step.
425
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GENERAL DEVELOPMENT DOCUMENT SECT - KI
The options listed above are general and can be applied to all
subcategories. Wastewater flow reduction within the nonferrous
metals manufacturing category is generally based on the recycle
of scrubbing liquors and casting contact cooling water.
Additional flow reduction is achievable for new sources through
alternative process methods which are subcategory-specific.
Additional flow reduction attainable for each subcategory is
discussed later in this section regarding the NSPS option
selection.
For several subcategories, the regulatory production normalized
flows for NSPS are the same as the production normalized flows
for the selected BAT option. The mass of pollutant allowed to be
discharged per mass of product is calculated by multiplying the
appropriate treatment effectiveness value (one-day maximum and
10-day average values) (mg/1) by the production normalized flows
(1/kkg), When these calculations are performed, the mass-based
NSPS can be derived for the selected option. Effluent
concentrations attainable by the NSPS treatment options are
identical to those presented in Section VII of this document
(Table VI1-21 page xxx) .
MODIFICATIONS TO EXISTING NSPS
New source performance standards had been promulgated previously
for the primary and secondary aluminum smelting subcategories.
The technology basis for these standards was lime precipitation,
sedimentation, and in-process flow reduction of process
wastewater. EPA is promulgating modifications to these NSPS to
incorporate changes promulgated for BAT and to include additional
flow reductions possible at new sources in the primary aluminum
subcategory.
As discussed in Section IX, the metallurgical acid plants
subcategory has been modified to include acid plants associated
with primary lead and zinc smelters, and primary molybdenum
roasters. This is based on the similarity between discharge
rates and effluent characteristics of wastewaters from all
metallurgical acid plants.
NSPS OPTION SELECTION
In general, EPA is promulgating that the best available
demonstrated technology be equivalent to BAT technology (NSPS
Option C). For the subcategories where EPA has reserved setting
BAT limitations, chemical precipitation, sedimentation, and
filtration is generally selected as the technology basis for
NSPS. The principal treatment method for Option C is in-process
flow reduction, chemical precipitation, sedimentation, and
multimedia filtration. Option C also includes ion exchange,
sulfide precipitation, cyanide precipitation, iron co-
precipitation, ammonia air or steam stripping, and oil skimming,
where required. As discussed in Sections IX and X, these
technologies are currently used at plants within this point
426
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GENERAL DEVELOPMENT DOCUMENT SECT - XI
source category. The Agency recognizes that new sources have the
opportunity to implement more advanced levels to treatment
without incurring the costs to retrofit equipment, and the costs
of partial or complete shutdown to install new production
equipment. Specifically the design of new plants can be based on
recycle of contact cooling water through cooling towers, recycle
of air pollution control scrubber liquor or the use of dry air
pollution control equipment. New plants also have the
opportunity to consider alternate degassing or slag granulation
methods during the preliminary design of the facility.
The data relied upon for selection of NSPS were primarily the
data developed for existing sources which included costs on a
plant-by-plant basis along with retrofit costs where applicable.
The Agency believes that compliance costs could be lower for new
sources than the cost estimates for equivalent existing sources,
because production processes can be designed on the basis of
lower flows and there will be no costs associated with
retrofitting the in-process controls. Therefore, new sources
will have costs that are not greater than the costs that existing
sources would incur in achieving equivalent pollutant discharge
reduction. Based on this analysis, the Agency believes that the
selected NSPS (NSPS Option C) is an appropriate choice.
Section II of each subcategory supplement presents a summary of
the NSPS for the Nonferrous Metals Manufacturing Point Source
Category. The pollutants selected for regulation for each
subcategory are identical to those selected for BAT with the
addition of conventional pollutant parameters (e.g., TSS, oil and
grease, and pH), The pollutants regulated under NSPS are
presented for each subcategory in Table XI-1 (page 435).
Presented below is a brief discussion describing the technology
option selected for NSPS for each subcategory.
Primary Aluminum Smelting
New source performance standards for primary aluminum are based
on BAT plus additional flow reduction. Additional flow reduction
is achievable through the use of dry air pollution scrubbing on
potlines, anode bake plants, and anode paste plants and
elimination of potroom and degassing scrubber discharges.
Potroom scrubbing discharges are eliminated by design of
efficient potline scrubbing (eliminating potroom scrubbing
completely) or 100 percent recycle (with blowdown recycled to
casting). Degassing scrubbers are limited by replacing chlorine
degassing with inert gases.
These flow reductions are demonstrated at existing plants, but
are not included in BAT because they might involve substantial
retrofit costs at other existing plants. However, new plants can
include these reductions in plant design at no significant
additional cost.
The Agency does not believe that the promulgated NSPS will
provide a barrier to entry for new facilities. In fact,
427
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GENERAL DEVELOPMENT DOCUMENT SECT - XI
installation of dry scrubbing instead of wet scrubbing in new
facilities reduces the cost of end-of-pipe treatment by reducing
the overall volume of wastewater discharged.
Secondary Aluminum Smelting
The technology basis and discharge allowances for NSPS are
equivalent to that of the promulgated BAT, with the exception of
dross washing. Dross washing is not provided a discharge
allowance in the NSPS because of the demonstration of dry milling
in the subcategory. Dry milling is not required for existing
sources due to the extensive retrofit costs of installing
milling, grinding, and screening operations. However, new
sources have the opportunity to install the best equipment
without the cost of major retrofits. The Agency also does not
believe that new plants could achieve any additional flow
reduction for chlorine demagging and casting contact cooling
beyond that promulgated for BAT.
Primary Copper Smelting
The promulgated NSPS for the primary copper smelting subcategory
is zero discharge of all process pollutants without a
catastrophic storm discharge allowance. The Agency believes that
new smelting facilities can be constructed using cooling towers
to cool and recirculate casting contact cooling water and slag
granulation wastewater instead of large volume cooling
impoundments. This technology is demonstrated in this
subcategory. Thus, this modification eliminates the allowance
for the catastrophic precipitation discharge allowed at BAT. The
costs associated with construction and operation of a cooling
tower system are not significantly greater than those for cooling
impoundments, and as such, the Agency believes that the
promulgated NSPS will not constitute a barrier for entry of new
facilities. As a result of this modification, the discharge of
toxic metals during months of net precipitation will be
eliminated.
Primary Electrolytic Copper Refining
The promulgated NSPS for the primary electrolytic copper refining
subcategory are equivalent to promulgated BAT. Review of the
subcategory indicates that no additional demonstrated
technologies exist that improve on BAT. The Agency also believes
that new plants could not achieve any additional flow reduction
beyond that promulgated for BAT.
Secondary Copper
New source performance standards for the secondary copper
subcategory are promulgated as zero discharge of all process
wastewater pollutants. It is believed that new sources can be
constructed with demonstrated cooling tower technology
exclusively and that the cost of cooling towers instead of
cooling impoundments is minimal. This eliminates the allowance
428
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GENERAL DEVELOPMENT DOCUMENT
SECT - XI
needed for catastrophic stormwater provided at BAT« Therefore,
NSPS, as defined, does not constitute a barrier to entry for new
plants.
Primary Lead
The promulgated NSPS prohibit the discharge of all process
wastewater pollutants from primary lead smelting except those
industrial hygiene streams provided an allowance at BAT and for
which an allowance remains necessary. Zero discharge is
achievable through complete recycle and reuse of dross and blast
furnace slag granulation wastewater or through slag dumping.
Elimination of discharge from dross or blast furnace slag
granulation is demonstrated in four of the six existing plants,
but it is not included at BAT because it would involve
substantial retrofit costs for the one existing discharger by
requiring the installation of a modified sintering machine. New
plants can include elimination of the discharge from the slag
granulation process in the plant design at no significant
additional cost. Elimination of the sinter plant materials
handling wet air pollution control waste stream is based on dry
scrubbing to control fugitive lead emissions during materials
handling. Therefore, NSPS does not present any barrier to entry
for new plants.
Primary Zinc
New source performance standards for the primary zinc subcategory
are promulgated equal to BAT. Review of the subcategory
indicates that no new demonstrated technologies exist that
improve on BAT.
Dry scrubbing is not demonstrated for controlling emissions from
zinc reduction furnaces, leaching, and product casting. The
nature of these emissions (acidic fumes, hot particulate matter)
technically precludes the use of dry scrubbers. Therefore, a
discharge allowance is included from this source at NSPS
equivalent to that promulgated, for BAT. The Agency believes that
new plants could not achieve any additional flow reduction beyond
that promulgated for 3AT.
Metallurgical Acid Plants
New source performance standards for the metallurgical acid
plants subcategory are promulgated equal to BAT. Review of the
subcategory indicates that no new demonstrated technologies exist
that improve on BAT. The Agency also does not believe that new
plants could achieve any additional flow reduction beyond that
promulgated for BAT.
Primary Tungsten
For the primary tungsten subcategory, NSPS are promulgated as
equal to BAT. Review of the subcategory indicates that no new
demonstrated technologies that improve on BAT exist.
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GENERAL DEVELOPMENT DOCUMENT SECT - XI
Dry scrubbing is not demonstrated for controlling emissions from
acid leaching, APT conversion to oxides and tungsten reduction
furnaces. The nature of these emissions (acid fumes, hot
particulate matter) technically precludes the use of dry
scrubbers. Therefore, a discharge allowance is included for
these sources at NSPS equivalent to that promulgated for BAT.
Also, the Agency does not believe that new plants could achieve
any additional flow reduction beyond the 90 percent scrubber
effluent recycle promulgated for BAT.
Primary Columbium-Tantalum
The promulgated NSPS for the primary columbium-tantalum
subcategory is equivalent to BAT. Review of the subcategory
indicates that no new demonstrated technologies that improve on
BAT exist.
Dry scrubbing is not demonstrated for controlling emissions from
concentration digestion, solvent extraction, precipitation,
oxides calcining, and reduction of tantalum salt to metal. The
nature of these emissions (acidic fumes, hot particulate matter)
technically precludes the use of dry scrubbers. Therefore, a
discharge allowance is included for these sources at NSPS
equivalent to that promulgated for BAT. The Agency also does not
believe that new plants could achieve any additional flow
reduction beyond that promulgated for BAT.
Secondary Silver
The promulgated NSPS for the secondary silver subcategory is
equivalent to BAT. Review of the subcategory indicates that no
new demonstrated technologies that improve on BAT exist.
Dry scrubbing is not demonstrated for controlling emissions from
film stripping and precipitation of film stripping solutions,
precipitation and filtration of photographic solutions, and
leaching and precipitation of non-photographic solutions. The
nature of these emissions (acidic fumes, hot particulate matter)
technically precludes the use of dry scrubbers. Therefore, a
discharge allowance is included for these sources at NSPS
equivalent to that promulgated for BAT. The Agency also does not
believe that new plants could achieve any additional flow
reduction beyond that promulgated for BAT.
Secondary Lead
The promulgated NSPS for the secondary lead subcategory is
equivalent to BAT with additional flow reduction over BAT levels
using dry scrubbing to control emissions from kettle refining.
Review of the subcategory indicates that no other new
demonstrated technologies that improve on BAT exist.
Existing wet scrubbers are used to control emissions and prevent
baghouse fires caused by sparking when sawdust and phosphorus are
430
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GENERAL DEVELOPMENT DOCUMENT SECT - XI
applied to the surface of the metal while in the kettle. Dry
scrubbers can be used for this purpose if spark arrestors and
settling chambers are installed to trap sparks. According to
the Secondary Lead Smelters Association, this is a demonstrated
and viable technology option. Dry scrubbing is not required at
BAT because of the extensive retrofit costs of switching from wet
to dry scrubbing. Dry scrubbing, however, is not demonstrated
for controlling emissions from blast and reverberatory furnaces,
and the nature of these emissions (hot particulate matter)
precludes the use of dry scrubbing. Therefore, a discharge
allowance is included for this source at NSPS equivalent to that
promulgated for BAT. The Agency also does not believe that new
plants could achieve any additional flow reduction beyond that
promulgated for BAT.
Primary Antimony
The promulgated NSPS for primary antimony are equal to BAT. We
do not believe that new plants could achieve any reduction in
flow beyond the flows prom-ulgated for BAT. Because NSPS is
equal to BAT, we believe that the NSPS will not pose a barrier to
the entry of new plants into this subcategory.
Primary Beryllium
The promulgated NSPS for primary beryllium are equal to BAT. We
do not believe that new plants could achieve any flow reduction
beyond the allowances promulgated for BAT. Because NSPS is equal
to BAT, we believe that the NSPS will not have a detrimental
impact on the entry of new plants into this subcategory.
Primary and Secondary Germanium and Gallium
The promulgated NSPS for primary and secondary germanium and
gallium are equal to BAT. We do not believe that new plants
could achieve any reduction in flow beyond the flow allowances
promulgated for BAT. Because NSPS is equal to BAT, we believe
that the NSPS will not have a detrimental impact on the entry of
new plants into this subcategory.
Secondary Indium
The NSPS for the secondary indium subcategory are based on
chemical precipitation and sedimentation, (the same model
technology as PSES). The pollutants and pollutant parameters
specifically limited under NSPS are cadmium, lead, zinc, indium,
total suspended solids, and pH. The priority pollutants
chromium, nickel, selenium, silver, and thallium were also
considered for regulation because they are present at treatable
concentrations in the raw wastewaters from this subcategory.
These pollutants were not selected for specific regulation
because they will be effectively controlled when the regulated
priority metals are treated to the levels achievable by the model
technology.
431
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GENERAL DEVELOPMENT DOCUMENT SECT - XI
The costs arid specific removal data for this subcategory are not
presented here because the data on which they are based has been
claimed to be confidential. We believe the promulgated NSPS are
economically achievable, and that they do not pose a barrier to
entry of new plants into this subcategory.
Secondary Mercury
The promulgated NSPS for secondary mercury are based on chemical
precipitation, sedimentation, and filtration. This technology is
fully demonstrated in many nonferrous metals manufacturing sub-
categories and would be expected to perform at the same level in
this subcategory.
The pollutants specifically limited under NSPS are lead, mercury,
TSS, and pH. The priority pollutants arsenic, cadmium, copper,
silver, and zinc were also considered for regulation because they
are present at treatable concentrations in the raw wastewaters
from this subcategory. These pollutants were not selected for
specific regulation because they will be effectively controlled
when the regulated priority metals are treated to the levels
achievable by the model technology.
We believe the promulgated NSPS are economically achievable, and
that they are not a barrier to entry of new plants into this
subcategory.
Primary Molybdenum and Rhenium
The promulgated NSPS for primary molybdenum and rhenium are equal
to BAT. We do not believe that new plants could achieve any flow
reduction beyond the allowances promulgated for BAT. Because
NSPS are equal to BAT, we believe that the NSPS will not have a
detrimental impact on the entry to new plants into this
subcategory.
Secondary Molybdenum and Vanadium
The promulgated NSPS for secondary molybdenum and vanadium are
equal to BAT. We do not believe that new plants could achieve
any reduction in flow beyond the flow allowances promulgated for
BAT. Because NSPS are equal to BAT, we believe that the NSPS
will not pose a barrier to the entry of new plants into this
subcategory.
Primary Nickel and Cobalt
The promulgated NSPS for primary nickel and cobalt are equal to
BAT. We do not believe that new plants could achieve any
reduction in flow beyond the flow allow-ances promulgated for
BAT. Because NSPS are equal to BAT, we believe that the NSPS
will not pose a barrier to the entry of new plants into this
subcategory.
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GENERAL DEVELOPMENT DOCUMENT SECT - XI
Secondary Nickel
The promulgated NSPS for secondary nickel are equivalent to PSES
(chemical precipitation and sedimentation technology). We do not
believe that new plants could achieve any reduction in flow
beyond the flow allowances promulgated for PSES. Because NSPS
are equal to PSES, we believe that the NSPS will not pose a
barrier to the entry of new plants into this subcategory.
Primary Precious Metals and Mercury
The promulgated NSPS for primary precious metals and mercury are
equal to BAT. We do not believe that new plants could achieve
any reduction in flow beyond the allowances promulgated for BAT.
Because NSPS are equal to BAT, we believe that the NSPS will not
have a detrimental impact on the entry of new plants into this
subcategory.
Secondary Precious Metals
The promulgated NSPS for secondary precious metals are equal to
BAT. We do not believe that new plants could achieve any
reduction in flow beyond the allowances promulgated for BAT.
Because NSPS are equal to BAT, we believe that the NSPS are
economically achievable, and that they are not a barrier to entry
of new plants into this subcategory.
Primary Rare Earth Metals
The promulgated NSPS for primary rare earth metals are equal to
BAT, which is based on in-process flow reduction, lime, settle
and filter treatment, followed by activated carbon polishing
technology for control of toxic inorganic and organic pollutants.
Although the BPT and BAT limitations were remanded for this
subcategory, EPA feels that new sources would be able to
economically achieve these new source standards.
The NSPS for this subcategory are based on in-process wastewater
flow reduction, followed by lime, settle, and filter and
activated carbon adsorption end of pipe treatments. Flow
reduction is based on 90 percent recycle of scrubber effluent.
Activated carbon technology is transferred from the iron and
steel category where it is a demonstrated technology for removal
of toxic organic pollutants.
The pollutants specifically limited under NSPS are
hexachlorobenzene, chromium, lead, and nickel. The priority
pollutants benzene, arsenic, cadmium, copper, selenium, silver,
thallium, and zinc were also considered for regulation because
they were found at treatable concentrations in the raw
wastewaters from this subcategory. These pollutants were not
selected for specific regulation because they will be effectively
controlled when the regulated priority pollutants are treated to
the levels achievable by the model NSPS technology.
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GENERAL DEVELOPMENT DOCUMENT SECT - XI
Secondary Tantalum
The promulgated NSPS for secondary tantalum are equal to BAT. We
do not believe that new plants could achieve any reduction in
flow beyond the allowances promulgated for BAT. Because NSPS are
equal to BAT, we believe that the NSPS will not pose a barrier to
the entry of new plants into this subcategory.
Secondary Tin
The promulgated NSPS for secondary tin are equal to BAT. We do
not believe that new plants could achieve any reduction in flow
beyond the allowances promulgated for BAT. Because NSPS are
equal to BAT, we believe that the NSPS will not pose a barrier to
the entry of new plants into this subcategory.
Primary and Secondary Titanium
The promulgated NSPS for primary and secondary titanium are equal
to BAT plus flow reduction technology with additional flow
reduction for four streams. Zero discharge is promulgated for
chip crushing, sponge crushing and screening, and scrap milling
wet air pollution control wastewater based on dry scrubbing.
Zero discharge is also promulgated for chlorine liquefaction wet
air pollution control based on by-product recovery of scrubber
liquor as hypochlorous acid. Cost for dry scrubbing air pollution
control in a new facility is no greater than the cost for wet
scrubbing which was the basis for BAT cost estimates. Because
NSPS are equal to BAT, we believe that the NSPS will not pose a
barrier to the entry of new plants into this subcategory.
Secondary Tungsten and Cobalt
The promulgated NSPS for secondary tungsten and cobalt are equal
to BAT. We do not believe that new plants could achieve any
reduction in flow beyond the allowances promulgated for BAT.
Because NSPS are equal to BAT, we believe that the NSPS will not
pose a barrier to the entry of new plants into this subcategory.
Secondary Uranium
The promulgated NSPS for secondary uranium are equal to BAT. We
do not believe that new plants could achieve any reduction in
flow beyond the allowances promulgated for BAT. Because NSPS are
equal to BAT, we believe that the NSPS will not pose a barrier to
the entry of new plants into this subcategory.
Primary Zirconium and Hafnium
The promulgated NSPS for pr imary zi rconium and hafnium are equal
to BAT. We do not believe that new plants could achieve any
reduction in flow beyond the allowances promulgated for BAT.
Because NSPS are equal to BAT, we believe that the NSPS will not
pose a barrier to the entry of new plants into this subcategory.
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GENERAL DEVELOPMENT DOCUMENT SECT - XI
Table XI-1
REGULATED POLLUTANT PARAMETERS
Subcategory
Primary Aluminum Smelting
Secondary Aluminum Smelting
Primary Electrolytic Copper
Refining
Primary Lead
Primary Zinc
Metallurgical Acid Plants
Pollutant Parameters
73.
benzo(a)pyrene
114,
antimony
121.
cyanide (total)
124.
nickel
aluminum
fluoride
oil and grease
TSS
pH
122.
lead
128.
z x n c
aluminum
ammonia (N)
oil and grease
phenolics (total
by 4-AAP method
TSS
pH
114.
arsenic
120.
copper
124.
nickel
TSS
pH
122.
lead
128.
zinc
TSS
pH
118.
cadmium
120.
copper
122.
lead
128.
zinc
TSS
pH
115.
arsenic
118.
cadmium
120.
copper
122.
lead
128.
z inc
TSS
pH
435
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GENERAL DEVELOPMENT DOCUMENT SECT - XI
Table XI-1 (Continued)
REGULATED POLLUTANT PARAMETERS
Subcategory
Primary Tungsten
Primary Columbium-Tantalum
Secondary Silver
Secondary Lead
Primary Antimony
Primary Beryllium
Primary and Secondary Germani
and Gallium
Pollutant Parameters
122.
lead
128.
zinc
ammonia (N)
TSS
pH
122.
lead
128.
zinc
ammonia (N)
fluoride
TSS
pH
120 .
copper
128.
zinc
ammonia (N)
TSS
pH
114 .
antimony
115.
arsenic
122 .
lead
128.
zinc
ammonia (N)
TSS
pH
114.
antimony
115.
arsenic
123.
mercury
TSS
pH
117.
beryllium
119.
chromium (total)
120.
copper
121.
cyanide
ammonia (as N)
fluor ide
TSS
pH
115 .
arsenic
122 .
lead
128.
zinc
fluor ide
TSS
pH
436
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GENERAL DEVELOPMENT DOCUMENT SECT - XI
Table XI-l (Continued)
REGULATED POLLUTANT PARAMETERS
Subcategory
Secondary Molybdenum and Vanadium
Primary Nickel and Cobalt
Primary Precious Metals and Mercury
Secondary Precious Metals
Primary Rare Earth Metals
Pollutant Parameters
115. arsenic
119. chromium
12 2. 1ead
124. nickel
molybdenum
ammonia (as N)
iron
TSS
pH
120. copper
124. nickel
cobalt
ammonia (as N)
TSS
pH
122. lead
123. mercury
126. silver
128. zinc
gold
oil and grease
TSS
pH
120. copper
121. cyanide
128. zinc
ammonia (as N)
gold
palladium
plat inum
TSS
pH
119. chromium (Total)
122. lead
124. nickel
TSS
pH
437
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GENERAL DEVELOPMENT DOCUMENT SECT - XI
Table Xi-l (Continued)
REGULATED POLLUTANT PARAMETERS
Subcategory
Pollutant Parameters
Secondary Tantalum
Secondary Tin
Primary and Secondary Titanium
Secondary Tungsten and Cobalt
Secondary Uranium
120.
122.
124.
128.
115.
121.
122.
119.
122.
124.
120.
124.
119.
120.
124.
copper
lead
nickel
zinc
tantalum
TSS
pH
arsenic
cyanide
lead
iron
tin
fluoride
TSS
pH
chromium (total)
lead
nickel
titanium
oil and grease
TSS
pH
copper
nickel
cobalt
tungsten
oil and grease
ammonia (as N)
TSS
pH
chromium
copper
nickel
fluoride
TSS
total)
438
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GENERAL DEVELOPMENT DOCUMENT SECT - XI
Table XI-1 (Continued)
REGULATED POLLUTANT PARAMETERS
Subcategory
Pollutant Parameters
Primary Zirconium and Hafnium
119. chromium (total)
121. cyanide (total)
12 2. lead
124. nickel
ammonia (as N)
TSS
PH
439
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GENERAL DEVELOPMENT DOCUMENT SECT -
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440
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
SECTION XII
PRETREATMENT STANDARDS
Section 307(b) of the Clean Water Act requires EPA to promulgate
pretreatment standards for existing sources (PSES), which must be
achieved within three years of promulgation, PSES are designed
to prevent the discharge of pollutants which pass through,
interfere with, or are otherwise incompatible with the operation
of publicly owned treatment works (POTW). The Clean Water Act of
1977 adds a new dimension by requiring pretreatment for
pollutants, such as heavy metals, that limit POTW sludge
management alternatives, including the beneficial use of sludges
on agricultural lands. The legislative history of the 1977 Act
indicates that pretreatment standards are to be technology-based,
analogous to the best available technology for removal of
priority pollutants.
Section 307(c) of the Act requires EPA to promulgate pretreatment
standards for new sources (PSNS) at the same time that it
promulgates NSPS. New indirect discharge facilities, like new
direct discharge facilities, have the opportunity to incorporate
the best available demonstrated technologies, including process
changes, in-plant controls, and end-of-pipe treatment
technologies, and to use plant site selection to ensure adequate
treatment system installation.
General Pretreatment Regulations for Existing and New Sources of
Pollution were published in the Federal Register, Vol. 46, No.
18, Wednesday, January 28, 1981. These regulations describe the
Agency's overall policy for establishing and enforcing
pretreatment standards for new and existing users of a POTW and
delineates the responsibilities and deadlines applicable to each
party in this effort. In addition, 40 CPR Part 403, Section
403.5(b), outlines prohibited discharges which apply to all users
of a POTW.
This section describes the treatment and control technology for
pretreatment of process wastewaters from existing sources and new
sources, and presents mass discharge limitations of regulated
pollutants for existing and new sources, based on the described
control technology. It also serves to summarize changes from
previous rulemakings in the nonferrous metals manufacturing
category.
REGULATORY APPROACH
There are 125 facilities, representing 28 percent of the
nonferrous metals manufacturing category, who discharge
wastewaters to POTW. Pretreatment standards are established to
ensure removal of pollutants discharged by these facilities which
may interfere with, pass through, or be incompatible with POTW
operations, A determination of which pollutants may pass through
or be incompatible with POTW operations, and thus be subject to
441
Preceding page blank
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
pretreatment standards, depends on the level of treatment used by
the POTW. In general, more pollutants will pass through or
interfere with a POTW using primary treatment (usually physical
separation by settling) than one which has installed secondary
treatment (settling plus biological treatment).
Many of the pollutants contained in nonferrous metals
manufacturing wastewaters are not biodegradable and are,
therefore, not effectively treated by such systems. Furthermore,
these pollutants have been known to pass through or interfere
with the normal operations of these systems. Problems associated
with the uncontrolled release of pollutant parameters identified
in nonferrous metals manufacturing process wastewaters to POTW
were discussed in Section VI.
The Agency based the selection of pretreatment standards for the
nonferrous metals manufacturing category on the minimization of
pass-through of priority pollutants at POTW. For each
subcategory, the Agency compared removal rates for each priority
pollutant limited by the pretreatment options to the removal rate
for that pollutant at well-operated POTW. The POTW removal rates
were determined through a study conducted by the Agency at over
40 POTW and a statistical analysis of the data. (See Fate of
Priority Pollutants in Publicly Owned Treatment Works, EPA 4 40/1-
80-301, October, 1980; and Determining National Removal Credits
for Selected Pollutants for Publicly Owned Treatment Works, EPA
440/82-008, September, 1982.) The POTW removal rates are
presented below:
Priority Pollutant POTW Removal Rate
Antimony
0%
Arsenic
0%
Cadmium
38%
Chromium
65%
Copper
58%
Cyanide
52%
Lead
48%
Mercury
69%
Nickel
19%
Selenium
0%
Silver
66%
Zinc
65%
Hexachlorobenzene
12%
Ammonia
40%
Fluoride
0%
Total Regulated Metals
62%
There were no data concerning POTW removals for beryllium, boron,
cobalt, germanium, indium, molybdenum, radium 226, thallium, tin,
titanium, and uranium, to compare with our estimates of in-plant
treatment. Removal of these pollutants is solubility related.
Since the removal of metal pollutants for which data are
available is also solubility related, EPA believes that these
pollutants may pass through a POTW. It was assumed, therefore,
442
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
that these metals pass through a POTW because they are soluble in
water and are not degradable. Pass-through data are not
available for benzo(a)pyrene; however, pass-through data for five
other polynuclear aromatic hydrocarbons do not exceed 83 percent.
This value was used for organics pass-through calculations.
A pollutant is deemed to pass through the POTW when the average
percentage removed nationwide by well-operated POTW, meeting
secondary treatment requirements, is less than the percentage
removed by direct dischargers complying with BAT effluent
limitations guidelines for that pollutant. (See generally, 46 FR
9415-16 (January 28, 1981).) For example, if the selected PSES
option removed 90 percent of the cadmium generated by the
subcategory, cadmium would be considered to pass through because
a well-operated POTW would be expected to remove 38 percent.
Conversely, if the selected PSES option removed only 30 percent
of the cadmium generated by the subcategory, it would not be
considered to pass through. In the latter case, cadmium would
not be selected for specific regulation because a well-operated
POTW would have a greater removal efficiency.
The analysis described above was performed for each subcategory
starting with the pollutants selected for regulation at BAT. The
conventional pollutant parameters (TSS, pH, and oil and grease)
and aluminum were not considered for regulation under
pretreatment standards. The conventional pollutants are
effectively controlled by POTW, while aluminum is used to enhance
settling. For those subcategories where ammonia was selected for
specific limitation, it will also be selected For limitation
under pretreatment standards. Most POTW in the United States are
not designed for nitrification. Hence, aside from incidental
removal, most, if not all, of the ammonia introduced into POTW
will pass through into receiving waters without treatment.
An examination of the percent removal for the selected
pretreatment options indicated that the pretreatment option
selected removed at least 95 percent of the priority pollutants
generated in the nonferrous metals manufacturing point source
category. Consequently, the priority pollutants regulated for
each subcategory under BAT will also be regulated under
pretreatment standards. Table XII-1 (page 460) presents the
pollutants selected for regulation for pretreatment standards.
MODIFICATIONS TO EXISTING PRETREATMENT STANDARDS
Existing pretreatment standards proposed for the nonferrous
metals manufacturing category are being revised to incorporate
the building block approach as discussed earlier. In addition,
information has become available regarding proposed pretreatment
standards that warrant revision of promulgated standards.
Primary Aluminum Smelting
Pretreatment standards for new sources had been promulgated
previously to limit the quantity of fluoride discharged from
443
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
primary aluminum smelters to POTW. The technology basis for this
limitation was lime precipitation and sedimentation. PSNS for
primary aluminum has been revised to incorporate the building
block approach and the same technology basis as for new sources.
Since the PSNS regulation was proposed, three additional
technologies have been identified as demonstrated or transferable
to the primary aluminum subcategory. These technologies,
filtration, activated carbon, and dry alumina for scrubbing
systems, would greatly reduce the amount of toxic pollutants
discharged by a new source. A thorough discussion of the
building block approach and selection of regulated pollutant
parameters is presented in the primary aluminum supplement.
Secondary Aluminum Smelting
The previously promulgated pretreatment standards for existing
secondary aluminum facilities limited the quantity of oil and
grease allowed to be discharged from metal cooling, the pH from
demagging fume scrubbers, and the quantity of ammonia discharged
from residue milling. These mass limitations have been revised
to include additional waste streams that warrant regulations and
to upgrade the technology basis so that it is analogous to the
promulgated BAT.
Pretreatment standards previously promulgated for new sources
require zero discharge of all process generated pollutants into
POTW with the exception of demagging fume scrubber liquor. A
discharge from this scrubber was allowed only when chlorine is
used as a demagging agent. Mass limitations developed for this
discharge were based on chemical precipitation and sedimentation
technology. Revision of the promulgated pretreatment standard
was necessary in light of comments and information received and
to incorporate the more thorough building block approach (see
Section X). An extensive description of the development of these
standards can be found in the secondary aluminum supplement.
Secondary Copper
The promulgated pretreatment standards for existing sources allows
the discharge of process wastewaters subject to limitations
developed from chemical precipitation and sedimentation
technology. Currently promulgated BAT limitations, however,
require zero discharge of all process wastewaters. Therefore,
PSES is being promulgated as zero discharge through recycle and
reuse making it equivalent to BAT.
iMetallurgical Acid Plants
As discussed in Section IX, the metallurgical acid plants sub-
category has been modified to include acid plants associated with
primary molybdenum roasters. This is based on the similarity
between discharge rates and effluent characteristics of waste-
waters from all metallurgical acid plants.
EPA sis not extend the applicability of the existing
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
metallurgical acid plant pretreatment standards to include
molybdenum acid plants because there are no indirect discharging
molybdenum acid plants.
We have extended the applicability of the existing PSNS for
metallurgical acid plants to include metallurgical acid plants
associated with primary molybdenum roasters. It is necessary to
promulgate PSNS to prevent pass-through of arsenic, cadmium,
copper, lead, and zinc. These priority pollutants are removed by
a well-operated POTW achieving secondary treatment at an average
of 42 percent, while BAT level technology removes approximately
83 percent.
We believe that the promulgated PSNS are achievable, and that
they are not a barrier to entry of new plants into this
subcategory.
OPTION SELECTION
The treatment schemes considered for pretreatment standards for
existing sources are identical to those considered for BAT. The
treatment schemes considered for pretreatment standards for new
sources are also identical to those considered for BAT with the
exception of primary aluminum smelting, secondary aluminum,
primary lead, and secondary lead, where additional flow reduction
is required. Each of the options considered builds upon the BPT
technology basis of chemical precipitation and sedimentation.
Depending on the pollutants present in the subcategories' raw
wastewaters, a combination of the treatment technologies listed
below were considered:
o Option A - End-of-pipe treatment consisting of chemical
precipitation, sedimentation, and ion-exchange, and
preliminary treatment, where necessary, consisting of
oil skimming, cyanide precipitation, sulfide precipi-
tation, iron co-precipitation, and ammonia air or steam
stripping. This combination of technology reduces
priority metals and cyanide, conventional, and
nonconventional pollutants.
o Option B - Option B is equal to Option A preceded by
flow reduction of process wastewater through the use
of cooling towers for contact cooling water and holding
tanks for all other process wastewater subject to
recycle.
o Option C - Option C is equal to Option B plus end-of-
pipe polishing filtration for further reduction of
priority metals and TSS.
o Option E - Option E consists of Option C plus activated
carbon adsorption applied to the total plant discharge
as a polishing step to reduce priority organic concen-
trations .
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The general approach taken by the Agency for pretreatment
standards for this category is presented below. The mass-based
standards for each subcategory may be found in Section II of each
subcategory supplement. The options selected for the category on
which to base pretreatment standards are discussed below.
Primary Aluminum Smelting
Pretreatment standards for existing sources will not be
promulgated for the primary aluminum smelting subcategory since
there are no existing indirect dischargers.
The technology basis for PSNS is identical to NSPS and includes
flow reduction, lime precipitation, sedimentation, and filtration
for control of toxic metals, and cyanide precipitation
preliminary treatment.
Secondary Aluminum Smelting
The technology basis for PSES is in-process flow reduction lime,
precipitation, sedimentation, and filtration. Preliminary
treatment consisting of ammonia steam stripping and activated
carbon adsorption is included for selected streams. The
achievable concentration for ammonia steam stripping is based on
iron and steel manufacturing category data. Flow reduction for
the selected technology option over current discharge rates
represents a 75 percent reduction in flow. Ammonia steam
stripping and lime precipitation and sedimentation, and filter
technologies are presently demonstrated in the nonferrous metals
manufacturing category. Ammonia air stripping was the technology
basis for the previously promulgated PSES. Steam stripping was
promulgated in this rule instead of air stripping because it is a
superior technology in that it does not transfer the pollutant
from one media to another. Activated carbon adsorption is
selected to control phenolics in the scrubber stream from
delacquering operations.
Implementation of the promulgated PSES would remove annually an
estimated 11,300 kg/yr of toxic pollutants, 96 kg/yr of ammonia,
and 212 kg/yr of phenolics over estimated raw discharges.
Capital cost for achieving promulgated PSES is $2.3 million (1982
dollars), and annual cost of $1.4 million.
The technology basis used to develop standards for new sources is
identical to those used for existing sources. There is no
demonstrated technology that is better than the PSES technology.
Primary Copper Smelting
No pretreatment standards for existing sources are promulgated
for the primary copper smelting subcategory since there are no
existing indirect dischargers.
The technology basis for promulgated PSNS is identical to NSPS
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
(and BAT), which is zero discharge of all process wastewater
pollutants, with no allowance for catastrophic stormwater
discharge. New indirect dischargers will be constructed with
cooling towers, not cooling impoundments, since they will be
located near POTW, suggesting that they will be near heavily
populated areas where land is scarce making the cost of acquiring
land to install an impoundment relatively high. Thus, we do not
believe there are any incremental costs associated with PSNS.
Primary Electrolytic Copper Refining
No pretreatment standards for existing sources are promulgated
for the primary electrolytic copper refining subcategory since
there are no existing indirect dischargers.
The technology basis of pretreatment for new sources is identical
to BAT and NSPS and is based on lime precipitation,
sedimentation, filtration, and 90 percent recycle for casting
contact cooling water. As in NSPS, all other waste streams
generated at copper refineries are not included in the flow
allowance.
Secondary Copper
As mentioned earlier in this section, PSES for secondary copper
is being modified to make it equivalent to BAT, or zero
discharge. Implementation of the promulgated PSES would remove
an estimated 9,500 kg/yr of toxic pollutants from raw discharges.
The estimated capital cost for achieving the promulgated PSES is
$0,654 million (1982 dollars) and the annual cost is $0,277
million.
The technology basis for promulgated PSNS is identical to NSPS,
PSES, and BAT. No allowance for catastrophic stormwater
discharges is provided as is discussed in Chapter XI for NSPS.
Primary Lead
The technology for promulgated PSES is equivalent to BAT
treatment and consists of in-process flow reduction, lime
precipitation, sedimentation, sulfide precipitation (and
sedimentation), and multimedia filtration. Implementation of the
promulgated PSES will remove an estimated 117 kg/yr of toxic
pollutants over raw discharge. The capital cost for achieving
PSES is $0,057 million (1982 dollars) and the annual cost is
$0,011 million.
The technology basis for promulgated PSNS is equivalent to NSPS
or zero discharge except for industrial hygiene streams provided
an allowance at NSPS. As discussed in Chapter XI for NSPS, slag
removed from dross reverberatory furnaces contains economical
recoverable amounts of lead that are granulated before recycling.
New facilities will have the opportunity to install dry slag
conditioning devices to eliminate the usage of wastewater in this
process or implement a 100 percent recycle system of slag
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
granulation wastewater. Elimination of the sinter plant
materials handling wet air pollution control stream can also be
accomplished with dry methods or 100 percent recycle. The Agency
believes the elimination of these process wastewater sources can
be accomplished without additional cost beyond BAT-equivalent
costs.
Primary Zinc
The technology basis for the promulgated PSES in the primary zinc
subcategory is equivalent to BAT. The treatment consists of in-
process flow reduction, lime precipitation, sedimentation,
sulfide precipitation (and sedimentation), and multimedia
filtration. Implementation of the PSES would remove an estimated
650,000 kg/yr of toxic pollutants over raw discharge. The
estimated capital cost for achieving PSES is $0.12 million (1982
dollars) and the annual cost is $0,058 million.
The technology basis for promulgated pretreatment standards for
new sources is equivalent to the NSPS basis of flow reduction,
lime precipitation, sedimentation, sulfide precipitation and
sedimentation, and filtration. The PSNS flow allowances are
based on minimization of process wastewater wherever possible
through the use of cooling towers to recycle contact cooling
water and sedimentation basins for wet scrubbing wastewater. The
discharges from contact cooling and scrubbers is based on 90
percent recycle. Elimination of wastewater from scrubbers by
installing dry scrubbers is not demonstrated for controlling
emissions from zinc reduction furnaces, leaching, and product
casting. The nature of emissions from these sources (acidic
fumes, hot particulate matter) technically precludes the use of
dry scrubbers.
Metallurgical Acid Plants
The technology basis for the promulgated PSES in the
metallurgical acid plants subcategory is equivalent to BAT. The
treatment consists of in-process flow reduction, lime
precipitation, sedimentation, and multimedia filtration. Sulfide
precipitation is included for all primary lead and primary zinc
acid plants and one primary copper acid plant. Implementation of
the promulgated PSES would remove approximately 12,500 kg/yr of
toxic metals over raw discharge. The capital cost for PSES is an
estimated $0.16 million (1982 dollars) and the annual cost is
$0,085 million.
The promulgated technology basis for pretreatment for new sources
is equivalent to the NSPS basis of flow reduction, lime
precipitation, sedimentation, sulfide precipitation, and
filtration. There is no demonstrated technology that provides
better pollutant removal than that promulgated for PSNS. The
acid plant blowdown allowance allocated for PSNS is based on 90
percent recycle. The Agency believes that no additional flow
reduction is feasible for new sources because the only other
available flow reduction technology, reverse osmosis, is not
448
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
demonstrated nor is it clearly transferable for this subcategory.
Primary Tungsten
The technology basis for the promulgated PSES in the
primary tungsten subcategory is equivalent to BAT. The selected
treatment consists of in-process flow reduction, lime
precipitation and sedimentation, ammonia steam stripping, and
filtration.
Implementation of the promulgated PSES limitations would remove
an estimated 3,400 kg/yr of toxic pollutants over estimated raw
discharge, and an estimated 63,320 kg/yr of ammonia. The capital
cost for achieving promulgated PSES is $0,568 million (1982
dollars), and annual cost of $0,445 million.
The technology basis for promulgated PSNS is identical to PSES,
The PSES flow allowances are based on minimization of process
wastewater wherever possible through the use of cooling towers to
recycle contact cooling water and sedimentation basins for wet
scrubbing wastewater. These discharges are based on 90 percent
recycle of these waste streams. Dry scrubbing is not
demonstrated for controlling emissions from acid leaching, APT
conversion to oxides and tungsten reduction furnaces. The nature
of these emissions (acidic fumes, hot particulate matter)
technically precludes the use of dry scrubbers.
Primary Columbium-Tantalum
The technology basis for the promulgated PSES in the
primary columbium-tantalum subcategory is equivalent to BAT. The
selected treatment consists of in-process flow reduction, lime
precipitation and sedimentation, ammonia steam stripping, and
filtration. Flow reduction is based on 90 percent recycle of
scrubber effluent that is the flow basis of BAT. This flow rate
is achieved by both indirect dischargers in the subcategory, and
filters are demonstrated at 23 plants in the nonferrous metals
manufacturing category.
Implementation of the promulgated PSES limitations would remove
18,590 kg/yr of toxic pollutants, 290,460 kg/yr of ammonia and
400,175 kg/yr of fluoride from raw discharges. Capital cost for
achieving promulgated PSES is $1.03 million (1982 dollars), and
annual cost of $0.7 million.
The technology basis for promulgated PSNS is identical to NSPS,
PSES and BAT. There is no known economically feasible,
demonstrated technology that is better than PSES technology. The
PSES flow allowances are based on minimization of process
wastewater wherever possible through the use of cooling towers to
recycle contact cooling water and sedimentation basins for wet
scrubbing wastewater. The discharges are based on 90 percent
recycle of these waste streams. Dry scrubbing is not
demonstrated for controlling emissions from concentration
digestion, solvent extraction, precipitation, oxides calcining,
449
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
and reduction of tantalum salt to metal. The nature of these
emissions (acidic fumes, hot particulate matter) technically
precludes the use of dry scrubbers.
Secondary Silver
The technology basis for the promulgated PSES in the secondary
silver subcategory is equivalent to BAT. The selected treatment
consists of in-process flow reduction, lime precipitation,
sedimentation, and multimedia filtration, along with ammonia
steam stripping preliminary treatment. Flow reduction is based
on complete recycle of furnace wet air pollution control.
Filtration is currently in place at eight of the 26 indirect
discharging secondary silver plants. Promulgated PSES would
remove an estimated 4,259 kg/yr of toxic pollutants and
approximately 42,400 kg/yr of ammonia generated by the industry.
Capital cost for achieving promulgated PSES is $0.63 million
(1982 dollars), with an annual cost of $0.42 million.
The promulgated technology basis for PSNS is equivalent to the
NSPS basis of in-process flow reduction, lime precipitation and
sedimentation, filtration, and ammonia steam stripping. Review
of the subcategory indicates that no new demonstrated
technologies that improve on this BAT technology exist.
Dry scrubbing is not demonstrated for controlling emissions from
film stripping and precipitation of film stripping solutions,
precipitation and filtration of photographic solutions, and
leaching and precipitation of non-photographic solutions. The
nature of these emissions (acidic fumes, hot particulate matter)
technically precludes the use of dry scrubbers. Therefore, an
allowance is included for these sources at PSES equivalent to
that promulgated for BAT and PSES. The Agency also does not
believe that new plants could achieve any additional flow
reduction beyond that promulgated for BAT.
Secondary Lead
The technology basis for the promulgated PSES in the secondary
lead subcategory is equivalent to BAT. The selected treatment
consists of in-process flow reduction, lime precipitation,
sedimentation, and multimedia filtration. Flow reduction is
based on 90 percent recycle of casting contact cooling water
through cooling towers. Filtration is achieved by five of the 26
indirect discharging secondary lead plants.
Implementation of the promulgated PSES would remove an estimated
46,500 kg/yr of toxic pollutants over estimated raw discharge.
Capital cost for achieving promulgated PSES is $4.26 million
(1982 dollars), with an annual cost of $2.51 million.
Pretreatment standards for new sources are equivalent to the NSPS
basis of in-process flow reduction, lime precipitation,
sedimentation and filtration with the additional flow reduction
over BAT levels using dry scrubbing to control emissions from
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
kettle refining. Flow reduction is based on 90 percent recycle
of scrubber effluent and casting contact cooling water using
cooling towers and holding tanks. There is no known demonstrated
technology that is better than the technology basis promulgated
for new secondary lead plants. Existing wet scrubbers are used
to control emissions and prevent baghouse fires caused by
sparking when sawdust and phosphorus are applied to the surface
of the metal while in the kettle. Dry scrubbers can be used for
this purpose if spark arrestors and settling chambers are
installed to trap sparks. According to the Secondary Lead
Smelters Association, this is a demonstrated and viable
technology option. Dry scrubbing is not required at BAT because
of the extensive retrofit costs of switching from wet to dry
scrubbing. Dry scrubbing is not demonstrated for controlling
emissions from blast and reverberatory furnaces, and the nature
of these emissions (hot particulate matter) precludes the use of
dry scrubbing.
Primary Antimony
Pretreatment standards for existing sources were not promulgated
for the primary antimony subcategory because there are no exist-
ing indirect dischargers. We have promulgated PSNS equivalent to
NSPS and BAT. The technology basis for PSNS is identical to NSPS
and BAT. It was necessary to promulgate PSNS to prevent pass-
through of priority metals. These metals are removed by a well-
operated POTW achieving secondary treatment at an average of 61
percent. PSNS technology removes these pollutants at an average
of 98 percent. No additional flow reduction for new sources is
feasible beyond the allowances promulgated for BAT. We believe
that the PSNS are not a barrier to entry of new plants into this
subcategory because they do not include any additional costs
compared to BAT.
Primary Beryllium
Pretreatment standards for existing sources were not promulgated
for the primary beryllium subcategory since there are no indirect
dischargers. The technology basis for promulgated PSNS is
identical to NSPS and BAT. It was necessary to promulgate PSNS
to prevent pass-through of beryllium, chromium, copper, cyanide,
and fluoride. These priority pollutants are removed by a
well-operated POTW achieving secondary treatment at an average of
41 percent while BAT technology removes approximately 93 percent.
The PSNS flow allowances are based on minimization to process
wastewater wherever possible through the use of holding tanks for
wet scrubbing wastewater. The flow allowances are identical to
those promulgated for BAT.
Primary and Secondary Germanium and Gallium
EPA promulgated PSES and PSNS limitations for this subcategory
based on chemical precipitation and sedimentation treatment.
We have promulgated PSES to prevent pass-through to arsenic,
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
lead, zinc, and fluoride. These pollutants are removed by a
well-operated POTW achieving secondary treatment at an average of
33 percent while BAT technology removes approximately 87 percent.
Implementation of the PSES limitations would remove annually an
estimated 564 kg of priority metal pollutants.
The costs and specific removal data for this subcategory are not
presented here because the data on which they are based have been
claimed to be cponfidential. The promulgated PSES will not result
in adverse economic impacts.
We have promulgated PSNS equivalent to PSES, NSPS and BAT. The
technology basis for promulgated PSNS is identical to NSPS, PSES,
and BAT. The same pollutants pass through as at PSES, for the
same reasons. We believe that the promulgated PSNS are not a
barrier to entry of new plants into this subcategory because they
do not include any additional costs compared to BAT.
Secondary Indium
PSES limitations for this subcategory are promulgated based on
chemical precipitation and sedimentation technology. The
pollutants specifically regulated under PSES are cadmium, lead,
zinc, and indium. The priority pollutants chromium, nickel,
selenium, silver, and thallium were also considered for regula-
tion because they are present at treatable concentrations in the
raw wastewaters from this subcategory. These pollutants were not
selected for specific regulation because they will be effectively
controlled when the regulated priority metals are treated to the
levels achievable by the model technology. It is necessary to
promulgate PSES to prevent pass-through of cadmium, lead, and
zinc. These toxic pollutants are removed by a well-operated POTW
achieving secondary treatment at an average of 38 percent while
this BAT level technology removes approximately 90 percent.
Implementation of the PSES limitations would remove annually an
estimated 586 kg of priority metals and 288 kg of indium.
We have promulgated PSNS equal to NSPS. The technology basis for
PSNS is identical to NSPS. The same pollutants pass through as
at PSES, for the same reasons.
We believe that the promulgated PSNS are achievable, and that
they are not a barrier to entry of new plants into this
subcategory.
Secondary Mercury
Pretreatment standards for existing sources were not promulgated
for the secondary mercury subcategory since there are no existing
indirect dischargers.
We have promulgated PSNS equivalent to NSPS for this subcategory.
It was necessary to promulgate PSNS to prevent pass-through of
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
lead and mercury. These pollutants are removed by a well-
operated POTW achieving secondary treatment at an average of 59
percent while PSNS level technology removes approximately 99
percent.
We believe that the promulgated PSNS are achievable, and that
they are not a barrier to entry of new plants into this
subcategory.
Primary Molybdenum and Rhenium
Pretreatment standards for existing sources were not promulgated
for the primary molybdenum and rhenium subcategory since there
are no existing indirect dischargers.
We have promulgated PSNS equal to BAT and NSPS for this
subcategory. It was necessary to promulgate PSNS to prevent
pass-through of arsenic, lead, nickel, selenium, molybdenum, and
ammonia. These priority pollutants are removed by a well-
operated POTW achieving secondary treatment at an average of 13
percent, while the NSPS and BAT level technology removes
approximately 79 percent.
We believe that the promulgated PSNS are achievable, and that
they are not a barrier to entry of new plants into this
subcategory.
Secondary Molybdenum and Vanadium
Pretreatment standards for existing sources were not promulgated
for the secondary molybdenum and vanadium subcategory since there
are no existing indirect dischargers.
We have promulgated PSNS equal to BAT and NSPS for this
subcategory. It was necessary to promulgate PSNS to prevent pass-
through of arsenic, chromium, lead, nickel, molybdenum, iron, and
ammonia. These priority pollutants are removed by a well-
operated POTW achieving secondary treatment at an average of 23
percent, while the NSPS and BAT level technology removes
approximately 98 percent.
The technology basis for PSNS is ammonia air stripping, iron co-
precipitation, chemical precipitation, sedimentation, and
filtration. The achievable concentration for ammonia air
stripping is based on nonferrous metals manufacturing category
data, as explained in the discussion of BPT and BAT in this
subcategory supplement.
We believe that the promulgated PSNS are achievable, and thac
they are not a barrier to entry of new plants into this
subcategory because they do not include any additional costs
compared to BAT.
Primary Nickel and Cobalt
453
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
Pretreatment standards for existing sources were not promulgated
for the primary nickel and cobalt subcategory since there are no
existing indirect dischargers.
We have promulgated PSNS equal to BAT and NSPS for this
subcategory. It was necessary to promulgate PSNS to prevent
pass-through to copper, nickel, cobalt, and ammonia. These
priority pollutants are removed by a well-operated POTW at an
average of 26 percent, while SAT technology removes approximately
58 percent.
The technology basis for PSNS is ammonia steam stripping,
chemical precipitation and sedimentation, and filtration. The
achievable concentration for ammonia steam stripping is based on
iron and steel manufacturing category data, as explained in the
discussion of BPT and BAT for this subcategory.
We believe that the promulgated PSNS are achievable, and that
they are not a barrier to entry of new plants into this
subcategory because they do not include any additional costs
compared to BAT.
Secondary Nickel
PSES for this subcategory are promulgated based on chemical
precipitation and sedimentation. The pollutants specifically
regulated under PSES are chromium, copper, and nickel. The
priority pollutants arsenic and zinc were also considered for
regulation because they are present at treatable concentrations
in the raw wastewaters from this subcategory. These pollutants
were not selected for specific regulation because they will be
effectively controlled when the regulated priority metals are
treated to the levels achievable by the model technology. We are
promulgating PSES to prevent pass-through to chromium, copper,
and nickel. These pollutants are removed by a well-operated POTW
at an average of 32 percent while PSES technology removes
approximately 84 percent.
Implementation of the promulgated PSES limitations would remove
annually an estimated 1,624 kg of priority metals from the raw
waste loads. We estimate a capital cost of $320,000 and, an
annualized cost of $161,233 to achieve PSES. The promulgated
PSES will not result in adverse economic impacts.
We have promulgated PSNS equivalent to NSPS and PSES. The same
pollutants pass through at PSNS as at PSES, for the same reasons.
The PSES flow allowances are based on minimization of process
wastewater wherever possible.
We believe that the promulgated PSNS are achievable, and that
they are not a barrier to entry of new plants into this
subcategory.
Primary Precious Metals and Mercury
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
Pretreatment standards for existing sources were not promulgated
for the primary precious metals and mercury subcategory because
there are no existing indirect dischargers.
We have promulgated PSNS equal to BAT and NSPS for this
subcategory. It was necessary to promulgate PSNS to prevent pass-
through of gold, lead, mercury, silver, and zinc. These priority
pollutants are removed by a well-operated POTW at an average of
62 percent, while the NSPS and BAT technology removes
approximately 93 percent.
The technology basis for PSNS is oil skimming, chemical
precipitation and sedimentation, wastewater flow reduction,
filtration and ion exchange. Flow reduction is based on 90
percent recycle of scrubber effluent that is the flow basis of
BAT.
We believe that the promulgated PSNS are achievable, and that
they are not a barrier to entry to new plants into this
subcategory because they do not include any additional costs
compared to BAT.
Secondary Precious Metals
The technology basis for the promulgated PSES in the secondary
precious metals subcategory is equivalent to BAT. It is
necessary to promulgate PSES to prevent pass-through of copper,
cyanide, zinc, ammonia, gold, palladium, and platinum. The
priority pollutants are removed by a well-operated POTW achieving
secondary treatment at an average of 32 percent while BAT level
technology removes approximately 99 percent. The technology
basis for PSES is chemical precipitation and sedimentation,
ammonia steam stripping, cyanide precipitation, wastewater flow
reduction, filtration, and ion exchange. The achievable
concentration for ammonia steam stripping is based on iron and
steel manufacturing category data, as explained in the discussion
of BPT and BAT for this subcategory. Flow reduction is based on
the same recycle of scrubber effluent and granulation water that
is the flow basis of BAT. Recycle is practiced by 21 of the 29
existing plants in the subcategory.
Implementation of the promulgated PSES limitations would remove
annually an estimated 110,300 kg of priority pollutants including
866 kg of cyanide, and an estimated 10,530 kg of ammonia from the
raw waste load. Capital cost for achieving PSES is $1,734,265
and annualized cost of $1,059,367. The proposed PSES will not
result in adverse economic impacts.
We have promulgated PSNS equivalent to NSPS and BAT. The
technology basis for promulgated PSNS is identical to NSPS and
BAT. The same pollutants pass through at PSNS as at PSES, for the
same reasons. The NSPS flow allowances are based on minimization
of process wastewater wherever possible through the use of
holding tanks to recycle wet scrubbing wastewater and granulation
water. The discharges are based on recycle of these waste
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
streams. We believe that the promulgated PSNS are achievable,
and that they are not a barrier to entry of new plants into this
subcategory because they do not include any additional costs
compared to BAT and PSES.
Primary Rare Earth Metals
PSES and PSNS for this subcategory are based on chemical
precipitation and sedimentation, in-process wastewater flow
reduction, filtration, and activated carbon adsorption. Flow
reduction is based on 90 percent recycle of scrubber effluent.
Activated carbon technology is transferred from the iron and
steel category where it is a demonstrated technology for removal
of priority organic pollutants.
The pollutants specifically limited under PSES and PSNS are
hexachlorobenzene, chromium, lead, and nickel. The priority
pollutants benzene, arsenic, cadmium, copper, selenium, silver,
thallium, and zinc were also considered for regulation because
they were found at treatable concentrations in the raw
wastewaters from this subcategory. These pollutants were not
selected for specific regulation because they will be effectively
controlled when the regulated priority pollutants are treated to
the levels achievable by the model PSES and PSNS technology.
Secondary Tantalum
Pretreatment standards for existing sources were not promulgated
for the secondary tantalum subcategory since there are no
existing indirect dischargers.
We have promulgated PSNS equal to NSPS and BAT. It was necessary
to promulgate PSNS to prevent pass-through of copper, lead,
nickel, zinc, and tantalum. These priority pollutants are
removed by a well-operated POTW achieving secondary treatment at
an average of 48 percent, while BAT level technology removes
approximately 99 percent.
We believe that the promulgated PSNS are achievable, and that
they are not a barrier to entry to new plants into this
subcategory because they do not include any additional costs
compared to BAT.
Secondary Tin
The technology basis for the promulgated PSES in the secondary
tin subcategory is equivalent to BAT. It is necessary to
promulgate PSES to prevent pass-through to arsenic, cyanide,
lead, iron, tin, and fluoride. These priority pollutants and
fluoride are removed by a well-operated POTW achieving secondary
treatment at an average of 17 percent while BAT technology
removes approximately 97 percent. The technology basis for PSES
is chemical precipitation, sedimentation, and filtration with
preliminary treatment consisting of cyanide precipitation where
required.
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Implementation of the promulgated PSES limitations would remove
annually an estimated 167 kg of priority metals, 6,227 kg of tin,
20 kg of cyanide, and 25,105 kg of fluoride over estimated cur-
rent discharge. Capital cost for achieving PSES is $160,187, and
annual cost of $50,044. The promulgated PSES will not result in
adverse economic impacts.
We have promulgated PSNS equivalent to PSES, NSPS, and BAT. The
technology basis for PSNS is identical to NSPS, PSES, and BAT.
The same pollutants pass through at PSNS as at PSES, for the same
reasons. The PSNS flow allowances are identical to the flow
allowances for BAT, NSPS, and PSES.
There would be no additional cost for PSNS above the costs
estimated for BAT. We believe that the promulgated PSNS are
achievable, and that they are not a barrier to entry of new
plants into this subcategory because they do not include any
additional costs compared to BAT and PSES.
Primary and Secondary Titanium
We have promulgated PSES equal to BAT for this subcategory. It
is necessary to promulgate PSES to prevent pass-through of
chromium, lead, nickel, and titanium. These priority pollutants
are removed by a well-operated POTW achieving secondary treatment
at an average of 14 percent while BAT technology removes
approximately 76 percent. Implementation of the promulgated PSES
limitations would remove annually an estimated 1.7 kg of priority
pollutants, and 147 kg of titanium from the current discharge.
The cost data for this subcategory are not presented here because
the data on which they are based have been claimed to be
confidential. The promulgated PSES will not result in adverse
economic impacts.
We have promulgated PSNS equivalent to NSPS. The technology
basis for promulgated PSNS is identical to NSPS. The same
pollutants are regulated at PSNS as at PSES and they pass through
at PSNS as at PSES, for the same reasons. The PSNS and NSPS flow
allowances are based on minimization to process wastewater
wherever possible through the use of cooling towers to recycle
contact cooling water and holding tanks for wet scrubbing
wastewater. The discharge allowance for pollutants is the same
at PSNS and NSPS. The discharges are based on 90 percent recycle
of these waste streams (see Section IX - recycle of wet scrubber
and contact cooling water). As in NSPS, flow reduction beyond
BAT (zero discharge) is promulgated for chip crushing, sponge
crushing and screening, and scrap milling wet air pollution
control wastewater based on dry scrubbing. Also, zero discharge
is promulgated for chlorine liquification wet air pollution
control wastewater based on by-product recovery.
We believe that the promulgated PSNS are achievable, and that
they are not a barrier to entry of new plants into this
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
subcategory because they do not include any additional costs
compared to BAT and PSES.
Secondary Tungsten and Cobalt
The technology basis for the promulgated PSES in the secondary
tungsten and cobalt subcategory is equivalent to BAT and PSNS.
It was necessary to promulgate PSES and PSNS to prevent pass-
through to copper, nickel, cobalt, tungsten, and ammonia. These
priority pollutants are removed by a well-operated POTW achieving
secondary treatment at an average of 26 percent, while the NSPS
and BAT level technology removes approximately 97 percent.
The technology basis for PSES and PSNS is ammonia steam strip-
ping, oil skimming, chemical precipitation and sedimentation, and
filtration. The achievable concentration for ammonia steam
stripping is based on iron and steel manufacturing category data,
as explained in the discussion of BPT and BAT for this
subcategory.
Implementation of the PSES limitations would remove annually an
estimated 13 kg of priority pollutants. Capital and annual costs
expected to be incurred to achieve PSES are $16,293 and $8,765,
respectively. The Agency has determined that PSES are
economically achievable and will not result in adverse economic
impacts.
We believe that the promulgated PSNS are achievable, and that
they are not a barrier to entry of new plants into this
subcategory because they do not include any additional costs
compared to BAT.
Secondary Uranium
Pretreatment standards for existing sources were not promulgated
for the secondary uranium subcategory since there are no existing
indirect dischargers.
We have promulgated PSNS equal to BAT and NSPS for this
subcategory. It was necessary to promulgate PSNS to prevent
passthrough of chromium, copper, nickel, and fluoride. These
priority pollutants are removed by a well-operated POTW achieving
secondary treatment at an average of 40 percent, while the NSPS
and BAT level technology removes approximately 88 percent.
The technology basis for PSNS is chemical precipitation,
sedimentation, and filtration, plus in-process wastewater flow
reduction.
We believe that the promulgated PSNS are achievable, and that
they are not a barrier to entry of new plants into this
subcategory because they do not include any additional costs
compared to BAT.
458
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
Primary Zirconium and Hafnium
EFA did not promulgate pretreatment standards for existing
sources for the primary zirconium and hafnium subcategory. We
had proposed PSES for this subcategory in a two tier regulatory
approach. However, we are excluding from national regulation
plants which only reduce zirconium or zirconium-nickel alloys
from zirconium dioxide with magnesium or hydrogen. Since the
only indirect discharger in the subcategory complies with this
requirement, we have decided not to establish PSES for this
subcategory. However, this facility will still be subject to
general pretreatment standards.
We are promulgating PSNS equivalent to NSPS and BAT. The
technology basis for promulgated PSNS is identical to NSPS. The
following priority pollutants pass through; chromium, cyanide,
lead, nickel, and ammonia. It is necessary to promulgate PSNS to
prevent pass-through. These pollutants are removed by a well-
operated POTW achieving secondary treatment at an average of 30
percent, while BAT technology removes approximately 80 percent.
We know of no economically feasible, demonstrated technology that
is better than BAT and NSPS technology.
We believe that the promulgated PSNS are achievable, and that
they are not a barrier to entry of new plants into this
subcategory because they do not include any additional costs
compared to BAT and PSES.
459
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GENERAL DEVELOPMENT DOCUMENT
SECT
XII
Table XII-1
POLLUTANTS SELECTED FOE REGULATION FOR PRETREATMENT
STANDARDS BY SUBCATEGORY
Subcategory
.... i m mi
Pollutant Parameters
Primary Aluminum Smelting*
73. benzo(a)pyrene
114. antimony
121. cyanide (total]
124. nickel
fluoride
Secondary Aluminum Smelting
Primary Copper Smelting
Primary Electrolytic Copper
Refining*
122. lead
128. zinc
ammonia (N)
phenolics
(by 4-AAP
Method)
114. arsenic
120. copper
124. nickel
Primary Lead
122.
128.
lead
zinc
Primary Zinc
118.
120.
122.
128.
cadmium
copper
lead
zinc
Metallurgical Acid Plants
115.
118.
120.
122.
128.
arsenic
cadmium+
copper
lead
zinc+
Primary Tungsten
122.
128.
lead
zinc
ammonia
(N)
Primary Columbium-Tantalum
122.
128.
lead
z inc
ammonia (N)
fluor ide
Secondary Silver
120.
128.
copper
z inc
ammonia
(N)
460
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
Table XII-1 (Continued)
POLLUTANTS SELECTED FOR REGULATION FOR PRETREATMENT
STANDARDS BY SUBCATEGORY
Subcategory Pollutant Parameters
Secondary Lead
114.
antimony
115.
arsenic
122.
lead
128.
zinc
ammonia (N)
Primary Antimony
114 .
antimony
115.
arsenic
123.
mercury
Primary Beryllium
117.
beryllium
119.
chromium
120.
copper
121.
cyanide
ammonia (as
N)
fluoride
Primary and Secondary
115.
a rsenic
Germanium and Gallium
122.
lead
128.
zinc
fluor ide
Secondary Indium
118.
cadmium
122.
lead
128.
zinc
indium
Secondary Mercury
122.
lead
123.
mercury
Primary Molybdenum
115.
arsenic
and Rhenium
122.
lead
124 .
nickel
125.
selenium
fluoride
molybdenum
ammonia (as
N)
Secondary Molybdenum
115.
arsenic
and Vanadium
119.
chromium
122.
lead
124 .
nickel
iron
molybdenum
ammonia (as
N)
461
-------
GENERAL DEVELOPMENT DOCUMENT SECT - XII
Table XII-1 (Continued)
POLLUTANTS SELECTED FOR REGULATION FOR PRETREATMENT
STANDARDS BY SUBCATEGORY
Subcategory
Primary Nickel and Cobalt
Secondary Nickel
Primary Precious Metals
and Mercury
Secondary Precious Metals
Primary Rare Earth Metals
Secondary Tantalum
Secondary Tin
Pollutant Parameters
120.
copper
124.
nickel
cobalt
ammonia (as N)
119.
chromium
120.
copper
124.
nickel
122.
lead
123.
mercury
126.
silver
128.
zinc
gold
120.
copper
121.
cyanide
128.
zinc
ammonia (as N)
gold
palladium
plat inum
9.
hexachlorobenzene
119.
chromium (total)
122.
lead
^.
nickel
120,
copper
122.
lead
124.
nickel
128.
zinc
tantalum
115.
arsenic
121.
cyanide
122.
lead
iron
tin
fluoride
462
-------
GENERAL DEVELOPMENT DOCUMENT SECT - XII
Table XII-1 (Continued)
POLLUTANTS SELECTED FOR REGULATION FOR PRETREATMENT
STANDARDS BY SUBCATEGORY
Subcategory Pollutant Parameters
Primary and Secondary
119.
chromium (total)
Titanium
122.
lead
124.
nickel
titanium
Secondary Tungsten
120.
copper
and Cobalt
124.
nickel
cobalt
tungsten
ammonia (as N)
Secondary Uranium
119 .
chromium (total)
120.
copper
124.
nickel
fluor ide
Primary Zirconium
119.
chromium (total)
and Hafnium
121.
cyanide (total)
122.
lead
124 .
nickel
ammonia (as N)
^Regulated by PSNS only.
+Regulated by PSES only.
463
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GENERAL DEVELOPMENT DOCUMENT SECT - XII
THIS PAGE INTENTIONALLY LEFT BLANK
464
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GENERAL DEVELOPMENT DOCUMENT SECT -XIII
SECTION XIII
BEST CONVENTIONAL POLLUTANT CONTROL TECHNOLOGY
EPA is not promulgating best conventional pollutant control
technology (BCT) for the nonferrous metals manufacturing category
at this time.
465
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GENERAL DEVELOPMENT DOCUMENT SECT -XIII
THIS PAGE INTENTIONALLY LEFT BLANK
466
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GENERAL DEVELOPMENT DOCUMENT SECT - XIV
SECTION XIV
ACKNOWLEDGMENTS
The nonferrous metals manufacturing project has been ongoing as a
regulation development project since the Consent Agreement of
1976 required EPA to re-study and expand the regulation of this
industry category. During this eleven year period many persons
have contributed in a meaningful way toward the successful
completion of the project. This section is intended to provide
some recognition to those who have labored in behalf of this
regulation development effort.
Much of the sampling, analysis, data compilation and draft
manuscript preparation has been conducted by contractors for the
EPA. The initial contractor in this effort was Sverdrup and
Parcel and Associates under Contact No. 68-01-4409. Technical
personnel of this contractor who worked on the project included:
Mr. Donald Washington, Project Manager, Mr. Garry Aronberg, Ms.
Claudia O'Leary, Mr. Antony Tawa, Mr. Charles Amelotti and Mr .
Jeff Carlton. The second and final contractor in this effort was
Radian Corporation under Contracts N. 68-01-6529, 68-01-6999 and
68-03-3411. Technical personnel of this contractor who worked on
the project included: Mr. James Sherman, Program Manager, Mr.
Mark Hereth, Project Director, Mr. Ron Dickson, Mr. John
Vidumsky, Mr. Richard Weisman, Mr. Tom Grome, Mr. Marc Papai, Ms.
Lori Stoll, Mr. John Collins, Mr. Mike Zapkin, Mr. Andrew Oven
and Ms. Diane Neuhaus. Acknowledgment and appreciation is also
made to the Radian secretarial staff, Ms. Nancy Johnson, Ms.
Sandra Zapkin and Ms. Daphne Phillips for their tireless efforts.
This regulation development project has been under the direction
of Mr. Ernst P. Hall, Chief of the Metals Industry Branch,
Industrial Technology Division of EPA. Technical Project
Officers for this project were (in order of succession) Ms.
Patricia Williams, Mr. James Berlow, Ms. Maria Irizarry, and Ms.
Eleanor Zimmerman, with assistant project Officers Mr. Geoffery
Grubbs and Mr. Stuart Colton. The final review and editing of
this document has been under the immediate direction of Mr. Hall.
Special note is made of the contribution of the word processing
staff of the Industrial Technology Division, Ms. Kaye Starr, Ms.
Nancy Zubric, Ms. Pearl Smith, Ms. Carol Swann and Ms. Glenda
Nesby and a special commendation is given to Ms. Smith for her
tireless efforts in producing the final drafts and camera ready
copy of the entire document.
The cooperation of the Aluminum Association, American Mining
Congress, Aluminum Recycling Association, Tantalum Producers
Association and Secondary Lead Smelters Association along with
their technical committees and individual companies that supplied
information and whose plants were sampled is gratefully
acknowledged.
467
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GENERAL DEVELOPMENT DOCUMENT SECT - XIV
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468
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
SECTION XV
REFERENCES
1. Sampling and Analysis Procedures for Screening of Industrial
Effluents for Priority Pollutants, USEPA Environmental Monitoring
and Support Laboratory, Cincinnati, OH 45268 (March, 1977,
revised April, 1977).
2. "Mineral Facts and Problems," Bureau to Mines Bulletin 667,
Washington. D.C., Department to the Interior (1975).
3. Development Document for Effluent Limitations Guidelines and
New Source Performance Standards for the Primary Aluminum Smelt-
ing Subcategory, EFA-4401/l-74-019d. Environmental Protection
Agency (March, 1974).
4. Development Document for Effluent Limitations Guidelines and
New Source Performance Standards for the Secondary Aluminum
Subcategory, EPA-400/1-74-019e, Environmental Protection Agency
(March, 1974).
5. Development Document for Interim Final Effluent Limitations
Guidelines and Proposed New Source Performance Standards for the
Primary Copper Smelting Subcategory and Primary Copper Refining
Subcategory, EPA-440/l-75/032b, Environmental Protection Agency
(February, 1975).
6. Development Document for Interim Final Effluent Limi tat ions
Guidelines and Proposed New Source Performance Standards for the
Secondary Copper Subcategory, EPA-4 4Q/l-7 5/032c, Environmental
Protection Agency (February, 1975).
7. Development Document for Interim Final Effluent Limitations
Guidelines and Proposed New Source Performance Standards for the
Lead Segment, EPA-440/l-7 5/0 32a, Environmental Protection Agency
(February, 1975).
8. Development Document for Interim Final Effluent Limitations
Guidelines and Proposed New Source Performance Standards for the
Zinc Segment, EPA-440/1-75/03 2 , Environmental Protection Agency
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Reporter - Cases 8 ERC 2120 (1976).
469
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
11. Development Document for Effluent Limitations Guidelines and
New Source Performance Standards for the Bauxite Refining Indus-
try, EPA-440/l-74/019c, Environmental Protection Agency (March,
1974).
12. Pound, C. E. and Crites, R. W., "Land Treatment of Municipal
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at USEPA Technology Transfer Seminars (1975).
13. Wilson, Phillip R., Brush Wellman, Inc., Elmore, OH,
Personal Communication (August, 1978).
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Brush Wellman, Inc. Plant in Elmore, OH, Brush Wellman, Inc.
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per, Lead and Zinc)," Transactions to the Metallurgical Society
of AIME, 224, 657 (August, 1976).
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Silver-Production Techniques," Information Circular 8266, United
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17. Technical Study Report: BATEA-NSPS-PSES-PSNS-Textile Mills
Point Source Category, Report submitted to EPA-Effluent Guide-
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(November, 1978).
18. The Merck Index, 8th edition, Merck & Co., Inc., Rahway, NJ
(1968).
19. Rose, A, and Rose, E., The Condensed Chemical Dictionary,
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470
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
25. Class notes and research compiled for graduate class, Autumn
Qtr. , 1976-77 School year at Montana State University by G. A.
Murgel.
26. Gough, P. and Shocklette, H. T., "Toxicity of Selected Ele-
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27. Second Interim Report - Textile Industry BATEA-NSPS-PSES-
PSNS Study, report submitted to EPA-Effluent Guidelines Division
by Sverdrup & Parcel and Associates, Inc. (June, 1978).
28. Proposed Criteria for Water Quality, Vol. 1, Environmental
Protection Agency (October, 1973) citing Vanselow, A. P.,
"Nickel, in Diagnostic Criteria for Plants and Soils," H. D.
Chapman, ed., University of California, Division of Agricultural
Science, Berkeley, pp. 302-309 (1966),
29. Morrison, R. T. and Boyd, R. N., Organic Chemistry, 3rd ed.,
Allyn and Bacon, Inc., Boston (1973).
30. McKee, J. E. and Woll, H. W. (eds), Water Quality Criteria,
2nd edition, California State Water Resources Control Board
(1963) citing Browning, E., "Toxicity of Industrial Metals,
Butterworth, London, England (1961).
31. citing Stokinger, H. E. and Woodward, R. L,, "Toxicologic
Methods for Establishing Drinking Water Standards," Journal AWWA,
50, 515 (1958).
32. citing Waldichuk, M., "Sedimentation of Radioactive Wastes
in the Sea," Fisheries Research Board of Canada, Circular No. 59
(January, 1961) .
33. citing "Quality Criteria for Water," U.S. Environmental
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34. Bronstein, M. A., Priviters, E. L., and Terlecky, P. M.,
Jr., "Analysis of Selected Wastewater Samples of Chrysotile
Asbestos and Total Fiber Counts - Nonferrous Metals Point Source
Category," Calspan Advanced Technology Center, Report No. ND-
5782-M-19 for USEPA, Effluent Guidelines Division (November 1,
1978).
35. Hallenbeck, W. H. and Hesse, C. S., "A Review of the
Health Effects of Ingested Asbestos," Review of Environmental
Health, 2, 3, 157 (1977).
36. McKee, J. E. and Wolf, H. W. (eds), Water qualiny Criteria,
2nd edition, California State Water Resources Control Board,
(1963) citing The Merck Index, 7th ed. , Merck & Co., Inc.,
Rahway, NJ (1960).
471
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
37. citing Pomelee, C. S., "Toxicity of Beryllium," Sewage
and Industrial Wastes, 25, 1424 (1953).
38. citing Rothstein, "Toxicology of the Minor Metals,"
University of Rochester, AEC Project, UR-26 2 (June 5, 1953).
39. citing Truhout, R. and Boudene, C., "Enquiries Into the
Facts of Cadmium in the Body During Poisoning: Of Special
Interest to Industrial Medicine," Archiv. Hig. Roda 5, 19 (19 54);
AMA Archives of Industrial Health 11, 179 (February, 1955).
40. citing Fairhall, L. T., "Toxic Contaminants of Drinking
Water," Journal New England Water Works Association, 55, 400
(1941).
41. citing Ohio River Valley Water Sanitation Commission,
"Report on the Physiological Effects of Copper on Man," The
Kettering Laboratory, College of Medicine, University of
Cincinnati, Cincinnati, OH (January 28, 1953).
42. citing "Copper and the Human Organism," Journal American
Water Works Association, 21, 262 (1929).
43. ci ting Taylor, E. W., "The Examination of Waters and
Water Supplies," P. Blakiston's Son and Co. (1949).
44. citing "Water Quality and Treatment," 2nd ed., AWWA
(1950).
45. citing Hale, F. E., "Relation to Copper and Brass Pipe
to Health," Water Works Eng., 95, 240, 84, 139, 187 (1942).
46. citing "Drinking Water Standards," Title 42 - Public Health
Chapter 1 - Public Health Service, Department to Health,
Education, and Welfare; Part 72 - Interstate Quarantine Federal
Register 2152 (March 6, 1962).
47. citing Derby, R. L., Hopkins, 0. C., Gullans, 0., Baylis,
J. R., Bean, E. L., and Malony, F., "Water Quality Standards,"
Journal American Water Works Association, 52, 1159 (September,
1960).
48. McKee, J. E. and Wolf, H. W., (eds.), Water Quality
Criteria, 2nd edition, California State Water Resources Control
Board, (1963) citing Klein, L., "Aspects of River Pollution,"
Butterworth Scientific Publications, London and Academic Press,
Inc., New York (1957).
49. citing Fuchess, H., Bruns, H., and Haupt, H,, "Danger of
Lead Poisoning From Water Supplies," Theo. Steinkopff (Dresden)
(1938); Journal American Water Works Association, 30, 1425
(1938) .
50. citing "Ohio River Valley Water Sanitation Commission,
Subcommittee on Toxicities, Metal Finishing Industries Acti on
472
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
Committee," Report No. 3 (1950),
51. Pickering, Q. H. and Henderson, C., "The Acute Toxicity of
Some Heavy Metals to Different Species of Warm Water Fish,"
Intnat. J. Air-Water Pollution, 10: 453-463 (1966).
52. Murdock, H. R. Industrial Wastes," Ind. Eng. Chem. 99A-102A
(1953).
53. Calabrese, A., et. al., "The Toxicity of Heavy Metals of
Embryos of the American Oyster, Crassostrea Virginicia," Marine
Biology 38: 162-166 (1973).
54. citing Russell, F. C., "Minerals in Pasture, Deficien-cies
and Excesses in Relation to Animal Health," Imperial Bureau of
Animal Nutrition, Aberdeen, Scotland, Tech. Communication 15
(1944).
55. citing Hurd-Kaner, A., "Selenium Absorption by Plants and
their Resulting Toxicity to Animals," Smithsonian Inst. Ann.
Rept., p. 289 (1934-35) .
56. citing Byers, H. G., "Selenium Occurrence in Certain Soils
in the United States with a Discussion of Related Topics," U.S.
Department of Agr. Tech. Bull. No. 582 (August, 1935).
57. citing Fairhall, L. T,, "Toxic Contaminants of Drinking
Water," Journal New England Water Works Association, 55, 400
(1941) .
58. citing Smith, M. I., Franke, K. W., and Westfall, B. B. ,
"Survey to Determine the Possibility of Selenium Detoxification
in the Rural Population Living on Seleniferous Soil," Public
Health Repts. 51, 1496 (1936).
59. citing Kehoe, R. A., Cholak, J., and Largent, E. J., "The
Hygienic ¦ Significance of the Contamination of Water with Certain
Mineral Constituents," Journal American Water Works Association,
36, 645 (1944).
60. citing Schwarz, K., "Effects of Trace Amounts of Selenium,"
Proc. Conf. Physical. Effects of Water Quality, U.S.P.H.S., p. 79
(September, 1960).
61. Water Quality Criteria of 1972. NAS Report.
62. US Department of Agriculture, Agricultural Research
Science, Consumer and Food Economics Research Division, "Food
Consumption of Households in the United States " (Spring, 1965),
Preliminary Report, Agricultural Research Service, Washington,
D.C.
63. Hill, W. R. and Pillsburg" D. M., "Argyria Investigation -
Toxicity Properties of Silver," American Silver Producers
Research Project Report, Appendix 11.
473
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
64. citing Brown, A, W. A,, "Insect Control by Chemicals," John
Wiley and Sons (1951).
65. Lougis, P., "The Physiological Effect of Zinc in Seawater,"
Comptes Rendu, Paris, 253:740-741 (1961).
66. Wisely, B. and Blick, R. A., "Mortality of Marine
Invertebrate Larvae in Mercury, Copper and Zinc Solutions," Aust.
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67. Clarice, G. L., "Poisoning and Recovery in Barnacles and
Mussels," Biol. Bull., 93:73-91 (1947).
68. Foreman, C. T., "Food Safety and the Consumer," EPA Jour. 4,
10, 16 (November/December, 1978).
69. Marnahan, S. E., Environmental Chemistry, 2nd ed., Willard
Grant Press, Boston (1975).
70. Methods for Chemical Analysis of Water and Wastes, Environ-
mental Monitoring and Support Laboratory, EPA-625/6-74-003a
USEPA, Cincinnati, OH (1976) .
71. Krocta, H. and Lucas, R. L., "Information Required for the
Selection and Performance Evaluation of Wet Scrubbers," Journal
of Pollution Control Association, 22, 6, 459.
72. Pourbaix, M., Atlas of Electrochemical Equilibria in
Aqueous Solutions, Pergamon Press, New York (1966) cited in
Development Document for Interim Final Effluent Limi tations
Guidelines and Proposed New Source Performance Standards for the
Primary Copper Smelting Subcategory and Primary Copper Refining
Subcategory, EPA-440/1-75/0 32b, Environmental Protection Agency
(February, 197 5).
73. Draft Development Document for Effluent Limitations Guide-
lines and New Source Performance Standards for the Miscellaneous
Nonferrous Metals Segment, EPA-440/1-76/067, Environmental
Protection Agency (March, 1977) citing Miller, D. G., "Fluoride
Precipitation in Metal Finishing Waste Effluent," Water-1974:I.
Industrial Waste Treatment, American Institute of Chemical
Engineers Symposium Series, 70, 144 (1974).
74. Parker and Fong, "Fluoride Removal: Technology and Cost
Estimates," Industrial Wastes (November/December, 1975).
75. Rohrer, L., "Lime, Calcium Chloride Beat Fluoride Waste-
water," Water and Wastes Engineering (November, 1974), p. 66
cited in Draft Development Document for Effluent Limitations
Guidelines and New Source Performance Standards for the
Miscellaneous Nonferrous Metals Segment, EPA-4 4 0/1-76/067 ,
Environmental Protection Agency (March, 1977).
76. Zabben, W. and Jewett, H. W., "The Treatment of Fluoride
474
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
Wastes," Proceedings of 22nd Industrial Waste Conference, Purdue
University (May 2-4, 1967), pp. 706-716.
77. Manual of Treatment Techniques for Meeting the Interim
Primary Drinking Water Regulations, EPA-60 0/8-77-005,
Environmental Protection Agency (April, 1978).
78. Patterson, J.W. "Technology and Economics of Industrial
Pollution Abatement," IIEQ Document #76/22 Project #20.07 OA
(1976).
79. Maruyama, T., Hannah, S. A., and Cohen, J. M., "Metal
Removal by Chemical Treatment Processes," Journal Water Pollution
Control Federation, 47, 5, 962.
80. Culp, G. L. and Culp, R. L., New Concepts in Water
Purification, (Van Nostrand, Reinhold and Company, New York
(1974), pp. 222-224.
81. Jenkins, S. N., Knight, D. G., and Humphreys, R. E., "The
Solubility of Heavy Metal Hydroxides in Water, Sewage, and Sewage
Sludge, I. The Solubility of Some Metal Hydroxides," Interna-
tional Journal of Air and Water Pollution, 8, 537 (1964).
82. Sittig, M., Pollutant Removal Handbook. Noyes Data Corp.,
Park Ridge, NJ (1973).
83. Link, W. E. and Rabosky, J. G,, "Fluoride Removal from
Wastewater Employing Calcium Precipitation and Iron Salt Coagu-
lation, " Proceedings of the 31st Industrial Waste Conference,
Purdue University, pp. 485-500 (1976).
84. Beychak, M. R., Aqueous Wastes from Petroleum and Petrochem-
ical Plants, John Wiley and Sons (1967) cited in Draft Develop-
ment Document for Effluent Limitations Guidelines and New Source
Performance Standards for the Miscellaneous Nonferrous Metals
Segment, EPA-440/1-7 6-067, Environmental Protection Agency
(March, 1977).
85. "Stripping, Extraction, Adsorption, and Ion Exchange,"
Manual on Disposal of Refinery Wastes - Liquid Wastes, American
Petroleum Institute, Washington, D. C. (1973) cited by Draft
Development Document for Effluent Limitations Guidelines and New
Source Performance Standards for the Miscellaneous Nonferrous
Metals Segment, EPA-440/1-76/067, Environmental Protection Agency
(March, 1977).
86. Grants, R. G., "Stripper Performance Tied to NH3 Fixation,"
Oil and Gas Journal, 73, 24, 80 (1975) cited by Draft Development
Document for Effluent Limitations Guidelines and New Source
Performance Standards for the Miscellaneous Nonferrous Metals
Segment, EPA-440/1-76/067, Environmental Protection Agency
(March, 1977).
87. Wrek, W, J. and Snow, R. H., "Design to Cross Flow Cooling
475
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
Towers and Ammonia Stripping Towers," Industrial Engineering
Process Design Development, 11, 3 (1972) cited by Draft Develop-
ment Document for Effluent Limitations Guidelines and New Source
Performance Standards for the Miscellaneous Metals Segment, EPA-
440/1-76-067, Environmental Protection Agency (March, 1977).
88. Mioderszewski, D., "Ammonia Removal - What's Best," Water
and Wastes Engineering (July, 1975) cited by Draft Development
Document for Effluent Limitations Guidelines and New Source
Performance Standards for the Miscellaneous Metals Segment, EPA-
440/1-76-067, Environmental Protection Agency (March, 1977).
89. Schlauch, R. M., and Epstein, A. C., Treatment to Metal
Finishing Wastes by Sulfide Precipitation, EPA 600/2-77-049.
90. Coleman, R. T., Colley, D. J., Klausmeier, R. F., Malish, D.
A., Meserole, N. P., Micheletti, W. C., and Schwitzgebel, K.,
Draft Copy Treatment Methods for Acidic Wastewater Containing
Potentially Toxic Metal Compounds, Report by Radian Corporation,
Aust in, TX, submi tted to USEPA Indust r ial Environmental Research
Laboratory, Cincinnati, OH (1978).
91. Settler, C. R., "Lime Neutralization of Low-Acidity Waste-
water," Proceedings of 32nd Industrial Waste Conference, Purdue
University (1977), p. 830.
92. Permuitt Co., Inc., Proceedings of seminar on metal waste
treatment featuring the Sulfex process, Paramus, NJ, undated.
93. Larson, H. P., Shou, K. P., Ross, L. W., "Chemical Treatment
of Metal Bearing Mine Drainage," Journal Water Pollution Control
Federation, 45, 8, 1682 (1974) cited by Coleman, R. T., et. al.,
Draft Copy Treatment Methods for Acidic Wastewater Containing
Potentially Toxic Metal Compounds, Report by Radian Corporation,
Austin, TX, submitted to USEPA Industrial Environmental Research
Laboratory, Cincinnati, OH (1978).
94. Murao, K. and Sei, N., "Recovery of Heavy Metals from the
Wastewater of Sulfuric Acid Process in Ahio Smelter," Proceedings
of Joint MMIJ AIME Meeting on World Mining and Metallurgical
Technology, Denver, September, 1976, Volume 2, pp. 808-16 (1976)
cited by Coleman, R. T., et. al., Draft Copy Treatment Methods
for Acidic Wastewater Containing Potentially Toxic Metal
Compounds, Report by Radian Corporation, Austin, TX, submitted to
USEPA Industrial Environmental Research Laboratory, Cincinnati,
OH (1978).
95. LaPerle, R. L., "Removal of Metals from Photographic
Effluent by Sodium Sulfide Precipitation," Journal Appl. Photogr.
Eng. 2, 134, (1976) cited by Coleman, R. T., et. al., Draft Copy
Treatment Methods for Acidic Wastewater Containing Potentially
Toxic Metal Compounds, Report by Radian Corporation, Austin, TX,
submitted to USEPA Industrial Environmental Research Laboratory,
Cincinnati, OH (1978).
476
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
96. Scott, M, (Senior Marketing Specialist, Permutit Company),
Private communications with R. Klausmeier (November, 1977) cited
by Coleman, R. T., et. al., Draft Copy Treatment Methods for
Acidic Wastewater Containing Potentially Toxic Metal Compounds,
Report by Radian Corporation, Austin, TX, submitted to USEPA
Industrial Environmental Research Laboratory, Cincinnati, OH
(1978).
97. Development Document for Interim Final and Proposed Effluent
Limitations Guidelines and New Source Performance Standards for
the Ore Mining and Dressing Industry, EPA-440/1-75-061, Environ-
mental Protection Agency (1975) cited by Coleman, R. T., et. al.,
Draft Copy Treatment Methods for Acidic Wastewater Containing
Potentially Toxic Metal Compounds, Report by Radian Corporation,
Austin, TX, submitted to USEPA Industrial Environmental Research
Laboratory, Cincinnati, OH (1978),
98. Coleman, R. T. and Malish, D. A,, Trip Report to Paul Bergoe
and Son, Boliden Aktiebolag and Outokumpu as part to EPA Contract
68-02-2608, Radian Corporation (November, 1977) cited by Coleman,
R. T., et. al., Dragt Copy Treatment Methods for Acidic Waste-
water Containing Potentially Toxic Metal Compounds, Report by
Radian Corporation, Austin, TX, submitted to USEPA Industrial
Environmental Research Laboratory, Cincinnati, OH ( 1978) .
99. Maltson, M. E., "Membrane Desalting Gets Big Push," Water
and Wastes Engineering (April, 1975), p. 35.
100. Cruver, J. E., "Reverse Osmosis for Water Reuse," Gulf
Environmental System (June, 1973).
101. "Water Renovation of Municipal Effluents by Reverse
Osmosis," Gulf Oil Corporation, San Diego (February, 1972).
102. Spatz, D. D., "Methods of Water Purification," Presented to
the American Association of Nephrology Nurses and Technicians at
the ASAIO AANNT Joint Conference, Seattle, Washington (April,
1972).
103. Donnelly, R. G., Goldsmith, R, L., McNulty, K. J., Grant,
D. C., and Tan, M.r Treatment to Electroplating Wastes by Reverse
Osmosis, EPA-6Q0/2-76-261, Environmental Protection Agency
(September, 1976).
104. Rook, J. J., "Halofarms in Drinking Water," Journal
American Water Works Association, 68:3:168 (1976).
105. Rook, J. J., "Formation to Haloforms During Chlor ir.ation of
Natural Waters," Journal Water Treatment Examination, 23:234
(1974).
106. Trussel1, R. R, and Umphres, M. D,, "The Formation of
Trihaloniethanes, " Journal American Water Works Association
70:11:604 (1978).
477
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
107. Nebel, C., Goltschlintg, R. D. , Holmes, J, L., and Unangst,
P. C., "Ozone Oxidation of Phenolic Effluents," Proceedings of
the 31st Industrial Waste Conference, Purdue University (1976),
pp. 940-951.
108. Rosen, H M., "Wastewater Ozonation: a Process Whose Time
Has Come," Civil Engineering, 47, 11, 65 (1976).
109. Hardisty, D. M. and Rosen, H. M., "Industrial Wastewater
Ozonation," Proceedings of the 32nd Industrial Waste Conference,
Purdue University (1976), pp. 940-951.
110. Traces of Heavy Metals in Water Removal Processes and
Monitoring, EPA-90 2/9-74-DO1, Environmental Protection Agency
(November, 1973).
111. Symons, J. M., "Interim Treatment Guide for Controlling
Organic Contaminants in Drinking Water Using Granular Activated
Carbon," Water Supply Research Division, Municipal Environmental
Research Laboratory, Office of Research and Development, USEPA,
Cincinnati, OH (January, 1978) .
112. McCreary, J. J. and V. L. Snoeyink, "Granular Activated
Carbon in Water Treatment," Journal American Water Works
Association, 69, 8, 437 (1977).
113. Grieves, C. G. and Stevenson, M. K., "Activated Carbon
Improves Effluents," Industrial Wastes (July/August, 1977), pp.
30-35.
114. Beebe, R. L. and Stevens, J. I., "Activated Carbon System
for Wastewater Renovation," Water and Wastes Engineering
(January, 1967), pp. 43-45.
115. Culp, G. L. and Shuckrow, A. J., "What lies ahead for PAC,"
Water and Wastes Engineering (February, 1977), pp. 67-72, 74.
116. Savinelli, E. A. and Black, A. P., "Defluoridation of Water
With Activated Alumina," Journal American Water Works
Association, 50, 1, 33 (1958).
117. Paulson, E. G., "Reducing Fluoride in Industrial Waste-
water," Chemical Engineering, Deskbook Issue (October 17, 1977}.
118. Bishop, P. L. and Sansovey, G., "Fluoride Removal from
Drinking Water by Fluidized Activated Alumina Adsorption,"
Journal American Water Works Association, 70,10,554 (1978).
119. Harmon, J. A. and Kalichman, S. C., "Defluoridation of
Drinking Water in Southern California," Journal American Water
Works Association, 57:2:245 (1965).
120. Maier, F. J., "Partial Defluoridation of Water," Public
Works, 91:90 (1960).
478
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
121. Bellack, E., "Arsenic Removal from Potable Water," Journal
American Water Works Association, 63, 7 (1971),
122. Gupta, S. K. and Chen, K. Y., "Arsenic Removal by Adsorp-
tion," Journal Water Pollution Control Association (March, 1978),
pp. 493-506.
123. Johnson, D. E, L., "Reverse Osmosis Recycling System for
Government Arsenal," American Metal Market (July 31, 1973) cited
in Draft Development Document for Effluent Limitations Guidelines
and New Source Performance Standards for the Miscellaneous
Nonferrous Metals Segment, EPA-44Q/1-76-067, Environmental
Protection Agency (March, 1977).
124. Nachod, F. C. and Schubert, J., Ion Exchange Technology,
Academic Press, Inc. (1956).
125. Volkert, David, and Associates, "Monograph on the Effec-
tiveness and Cost of Water Treatment Processes for the Removal of
Specific Contaminants," EPA 68-01-1833, Office of Air and Water
(1974) cited by Contaminants Associated with Direct and Indirect
Reuse of Municipal Wastewater, EPA-600/1-78-019 (March, 1978).
126. Clark, J. W., Viessman, W., Jr., and Hammer, M., Water
Supply and Pollution Control, (3rd ed.) IEP, New York (1977).
127. AWARE (Associated Water and Air Resources Engineers, Inc.),
Analysis to National Industrial Water Pollution Control Costs,"
(May 21, 1973).
128. AWARE, "Alternatives for Managing Wastewater in the Three
Rivers Watershed Area," (October, 1972).
129. Bechtel, "A Guide to the Selection of Cost-Effective
Wastewater Treatment Systems," EPA 430/9-75-002 (July, 1975).
130. Smith R., "Cost of Conventional and Advanced Treatment of
Wastewater," Journal Water Pollution Control Federation, 40, 9,
1546 (1968).
131. Icarus, "Capital and Operating Costs of Pollution Control
Equipment Modules," Vols. I and II, EPA-R5~73-023a & b (July,
1973).
132. Monti, R. P. and Silberman, P. T., "Wastewater System
Alternatives: What Are They . . . and What Cost," Water and
Waste Engineering (May, 1974), p. 40,
133. Process Design Manual for Removal of Suspended Solids, EPA-
625/175-003a (January, 1975).
134. Process Design Manual for Carbon Adsorption, EPA 625/1-
71~Q02a (October, 1973).
135. Grits, G. J., "Economic Factors in Water Treatment,"
479
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
Industrial Water Engineering (November, 1971), p. 22.
136. Barnard, J. L. and Eckenfelder, W. W., Jr., "Treatment Cost
Relationships for Industrial Waste Treatment, Environmental and
Water Resou rces Engineering, Vande rbi11 University (1971).
137. Grits, G. J. and Glover, G. G., "Cooling Blowdown in
Cooling Towers," Water and Wastes Engineering (April, 1975), p.
45.
138. Kremen, S. S., "The True Cost of Reverse Osmosis,"
Industrial Wastes (November/December, 1973), p. 24.
139. Cruver, J. E. and Sleigh, J. H., "Reverse Osmosis - The
Emerging Answer to Seawater Desalination," Industrial Water
Engineering (June/July, 1976), p. 9.
140. Doud, D. H., "Field Experience with Five Reverse Osmosis
Plants," Water and Sewage Works (June, 1976), p. 96.
141. Lacey, R. E. and Loed, S., (eds.), "Industrial Processing
with Membranes," in The Cost of Reverse Osmosis, John Wiley and
Sons (1972).
142. Disposal of Brines Produced in Renovation of Industrial
Wastewater, FWPA Contract #14-12-492 (May, 1970).
143. Process Design Manual for Sludge Treatment and Disposal,
EPA 625/1-74-006 (October, 1974).
144. Black & Veatch, "Estimating Cost and Manpower Requirements
for Conventional Wastewater Treatment Facilities," EPA Contract
#14-12-462 (October, 1971).
145. Osmonics, Inc., "Reverse Osmosis and Ultrafiltration
Systems Bulletin No. G7606," (1978).
146. Buckley, J. D., "Reverse Osmosis Moving from Theory to
Practice," From Fluid Systems Div., UOP, Inc. (Reprint from
Consulting Engineer), 45, 5, 55 (1975).
147. Process Design Manual for Nitrogen Control, EPA-Technology
Transfer (October, 1975).
148. Rizzo and Shepherd, "Treating Industrial Wastewater with
Activated Carbon," Chemical Engineering (January 3, 1977).
149. Richardson, "1978-79 Process Equipment," Vol. 4 of
Richardson Rapid System.
150. Thiansky, D. P., "Historical Development of Water Pollution
Control Cost Functions," Journal Water Pollution Control
Federation, 46, 5, 813 (1974).
151. Zimmerman, 0. T., "Wastewater Treatment," Cost Engineering
480
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
{October, 1971), p. 11.
152. Watson, I. C., (Control Research, Inc.) "Manual for
Calculation of Conventional Water Treatment Costs," Office of
Saline Water {March, 1972).
153. Culp, R. L., Wesner, G. M., Gulp, G. L., Handbook of
Advanced Wastewater Treatment, McGraw Hill {1978).
154. Dynatech R/D Company, A Survey of Alternate Methods for
Cooling Condenser Discharge Water Large-Scale Heat Rejection
Equipment, EPA Project No. 16130 DHS (July, 1969).
155. Development Document for Steam Electric Power Generating,
EPA 440/1-73/029 {March, 1974).
156. "Cooling Towers - Special Report," Industrial Water
Engineering (May, 1970).
157. AFL Industries, Inc., "Product Bulletin #12-05.B1 {Shelter
Uses)," Chicago, IL (December 29, 1977).
158. Fisher Scientific Co., Catalog 77 (1977).
159. Isco, Inc., Purchase Order Form, Wastewater Samplers
(1977).
160. Dames & Moore, Construction Cost for Municipal Wastewater
Treatment Plants: 1973-1977, EPA-430/9-77-013, MCD-37 (January,
1978).
161. Metcalf & Eddy, Inc., Wastewater Engineering; Collection,
Treatment, Disposal, McGraw-Hill, New York (1972).
162. Obert, E. F. and Young, R. L., Elements of Thermodynamics
and Heat Transfer, McGraw-Hill (1962), p. 270.
163. Paulson, E. G., "How to Get Rid of Toxic Organics,"
Chemical Engineering, Deskbook Issue {October 17, 1977), pp. 21-
27.
164. CH2-M-Hill, "Estimating Staffing for Municipal Wastewater
Treatment Facilities," EPA #68-01-0328 (March, 1973).
165. "EPA Indexes Reflect Easing Costs," Engineering News Record
(December 23, 1976), p. 87.
166. Chemical Marketing Reporter, Vol. 210, 10-26 (December 6
and December 20, 1976).
167. Smith, J. E., "Inventory of Energy Use in Wastewater Sludge
Treatment and Disposal," Industrial Water Engineering
(July/August, 1977).
168. Jones, J. L., Bomberger, D. C., Jr., and Lewis, F. M.,
481
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
"Energy Usage and Recovery in Sludge Disposal, Parts 1 & 2, "Water
and Sewage Works (July and August, 1977), pp. 44-47 and 42-46.
169. Hagen, R. M. and Roberts, E. B., "Energy Requirements for
Wastewater Treatment, Part 2," Water and Sewage Works (December,
1976), p. 52.
170. Banersi, S. K. and 0'Conner, J. T., "Designing More Energy
Efficient Wastewater Treatment Plants," Civil Engineering
(September, 1977), p. 76.
171. "Electrical Power Consumption for Municipal Wastewater
Treatment," EPA-R2-73-281 (1973).
172. Hillmer, T, J., Jr., "Economics of Transporting Wastewater
Sludge," Public Works (September, 1977), p. 110.
173. Ettlich, W. F., "Economics of Transport Methods of Sludge."
Proceedings of the Third National Conference on Sludge Manage-
ment , Disposal and Utilization (December 14-16, 1976), pp. 7-14.
174. NUS/Rice Laboratory, "Sampling Prices," Pittsburgh, PA
(1978).
175. WARF Instruments, Inc., "Pricing Lists and Policies,"
Madison, WI (June, 15, 1973) .
176. Orlando Laboratories, Inc., "Service Brochure and Fee
Schedule #16," Orlando, FL (January 1, 1978) .
177. St. Louis Test ing Laboratory, "Water and Wastewater
Analysis - Fee Schedule," St. Louis, MO (August, 1976).
178. Ecology Audits, Inc., "Laboratory Services - Individual
Component Analysis," Dallas, TX (August, 1976).
179. Laclede Gas Company, (Lab Div.), "Laboratory Pricing
Schedule," St. Louis, MO (August, 1977).
180. Industrial Testing Lab, Inc. , "Price List," St. Louis, MO
(October, 1975).
181. Luther, P. A., Kennedy, D. C., and Edgerley, E., Jr.
"Treatability and Functional Design of a Physical-Chemical
Wastewater Treatment System for a Printing and Photodeveloping
Plant," 31st Purdue Industrial Waste Conference, pp. 876-884
(1976) .
182. Hindin, E. and Bennett, P. J., "Water Reclamation by
Reverse Osmosis," Water and Sewage Works, 116, 2, 66 (February,
1969).
183. Cruver, J. E. and Nusbaum, I., "Application of Reverse
Osmosis to Wastewater Treatment," Journal Water Pollution Control
Association, 476, 2, 301 (February, 1974).
482
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GENERAL DEVELOPMENT DOCUMENT SECT - XV
184. Cruver, J. E., "Reverse Osmosis - Where It Stands Today,"
Water and Sewage Works, 120, 10, 74 (October, 1973).
185. Vanderborght, B. M. and Vangrieken, R. E., "Enrichment of
Trace Metals by Adsorption on Activated Carbon," Analytic
Chemistry, 49, 2, 311 (February, 1977).
186. Hannah, S. A., "Jelus, by Physical and Chemical Treatment
Processes," Journal Water Pollution Control Federation, 50, 11,
2297 (1978).
187. Argo, D. G. and Gulp, G. L., "Heavy Metals Removed in
Wastewater Treatment Processes - Parts 1 and 2," Water and Sewage
Works, August, 1972, pp. 62-65, and September, 1972, pp. 128-132.
188. Eager, D. G., "Industrial Wastewater Treatment by Granular
Activated Carbon," Industrial Water Engineering, pp. 14-28
(January/February, 1974) 189. Rohrer, K. L., "Chemical
Precipitants for Lead-Bearing Wastewaters," Industrial Water
Engineering, 12, 3 13 (1975).
189. Brody, M. A. and Lumpkins, R. J., "Performance of Dual-
Media Filters," Chemical Engineering Progress (April, 1977).
190. Bernardin, F. E., "Cyanide Detoxification Using Absorption
and Catalytic Oxidation," Journal Water Pollution Control
Federation, 45, 2 (February, 1973).
191. Russel, D. L., "PCB's: The Problem Surrounding Us and What
Must be Done," Pollution Engineering (August, 1977).
192. Chriswell, C. D., et. al., "Comparison of Macroreticular
Resin and Activated Carbon as Sorbents," Journal American Water
Works Association (December, 1977).
193. Gehm, H. W. and Bregman, J. I., Handbook of Water Resources
and Pollution Control, Van Nostrand Reinhold Company (1976).
194. Considine, Douglas M., Energy Technology Handbook,
McGraw-Hill Book Company, New York, c.1977, pp. 5-173-5-181.
195. Absalom, Sandra T., Boron,
Bureau of Mines, Washington, D.C.,
196. Rathen, John A,, Antimony,
Bureau of Mines, Washington, D.C.,
197. Harris, Keith L., Cesium,
Bureau of Mines, Washington, D.C.,
U.S. Dept. of the Interior,
May, 1979.
U.S. Dept. to the Interior,
June, 1979.
U.S. Dept. of the Interior,
May, 1979.
483
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GENERAL DEVELOPMENT DOCUMENT SECT -
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484
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GENERAL DEVELOPMENT DOCUMENT SECT - XVI
SECTION XVI
GLOSSARY
This section is an alphabetical listing to technical terras (with
definitions) used in this document which may not be familiar to
the reader.
4-AAP Colorimetric Method
An analytical method for total phenols and total phenolic com-
pounds that involves reaction with the color developing agent 4-
aminoantipyr ine.
Acidity
The quantitative capacity to aqueous solutions to react with
hydroxyl ions. It is measured by titration with a standard
solution to a base to a specified end point, and is usually
expressed as milligrams per liter to calcium carbonate.
The Act
The Federal Water Pollution Control Act Amendments of 1972 as
amended by the Clean Water Act to 1977 (PL 92-500).
Amortization
The allocation of a cost or account according to a specified
schedule, based on the principal, interest and period of cost
allocation.
Analytical Quantification Level
The minimum concentration at which quantification of a specified
pollutant can be reliably measured.
Anglesite
A mineral occurring in crystalline form or as a compact mass,
Antimonial Lead
An alloy composed of lead and up to 25 percent antimony.
Backwashinq
The operation of cleaning a filter or column by reversing the
flow of liquid through it and washing out matter previously
trapped.
485
Preceding page blank
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GENERAL DEVELOPMENT DOCUMENT SECT - XVI
Baqhouses
The area for housing bag type air filters, an air pollution control
equipment device.
Ball Mill
Pulverizing equipment for the grinding of raw material. Grindinq
is done by steel balls, pebbles, or rods.
Barton Process
A process for making lead oxide to be used in lead acid
batteries. Molten lead is fed, agitated, and stirred in a pot
with the resulting fine droplets oxidized. Material is collected
in a settling chamber where crystalline varieties of lead oxide
are formed.
Batch Treatment
A waste treatment method where wastewater is collected over a
period of time and then treated prior to discharge. Treatment is
not continuous, but collection may be continuous.
Bench Scale Pilot Studies
Experiments providing data concerning the treatability of a
wastewater stream or the efficiency of a treatment process con-
ducted using laboratory-size equipment.
Best Available Demonstrated Technology (BDT)
Treatment technology upon which new source performance standards
are to be based as defined by Section 306 to the Act.
Best Available Technology Economically Achievable (BAT)
The selected technology applicable to control toxic and
nonconventional pollutants on which effluent limitations are
established. These limitations are to be achieved by July 1,
1984 by industrial discharges to surface waters as defined by
Section 301(b)(2)(C) of the Act.
Best Conventional Pollutant Control Technology (BCT)
The selected technology applicable to control conventional
pollutants used to develop effluent limitations to be achieved by
July 1, 1984 for industrial discharges to surface waters as
defined in Section 301(b)(2)(E) of the Act.
Best Management Practices (BMP)
Regulations intended to control the release of toxic and hazard-
ous pollutants from plant runoff, spillage, leaks, solid waste
disposal, and drainage from raw material storage.
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GENERAL DEVELOPMENT DOCUMENT SECT - XVI
Best Practicable Control Technology Currently Available (BPT)
The selected technology applicable to develop effluent limita-
tions to have been achieved by July 1, 1977 (originally) for
industrial discharges to surface waters as defined by Section
301(b)(1)(A) of the Act.
Better ton Process
A process used to remove bismuth from lead by adding calcium and
magnesium. These compounds precipitate the bismuth which floats
to the top of the molten bath where it can be skimmed from the
molten metal.
Billet
A long, round slender cast product used as raw material in
subsequent forming operations.
Biochemical Oxygen Demand (BOD)
The quantity of oxygen used in the biochemical oxidation of
organic matter under specified conditions for a specified time.
Blast Furnace
A furnace for smelting ore concentrates. Heated air is blown in
at the bottom to the furnace, producing changes in the combustion
rate.
Blister Copper
Copper with 96 to 99 percent purity and appearing blistered; made
by forcing air through molten copper matte.
Blowdown
The minimum discharge to circulating water from a unit operation
such as a scrubber for the purpose of discharging dissolved
solids or other contaminants contained in the water, the further
buildup of which would cause concentration in amounts exceeding
limits established by best engineering practice.
Building Block
The smallest sub-unit or segment of a subcategory for which a
specific effluent limitation is established. Building blocks are
directly usable in defining the processes used in a plant and in
developing the discharge allowances for that plant.
Calcining
Heating to a high temperature without fusing so as to remove
material or make other changes.
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GENERAL DEVELOPMENT DOCUMENT SECT - XVI
Carbon Reduction
The process of using the carbon of coke as a reducing agent in
the blast furnace.
Cementation
A process in which metal is added to a solution to initiate the
precipitation of another metal. For example, iron may be added
to a copper sulfate solution to precipitate Cu:
CUSO41s + pe _F Cu + FeS04
Cerussite
A mineral occurring in crystalline form and made of lead
carbonate.
Charge
Material that has been melted by being placed inside a furnace.
Charging Scrap
Scrap material put into a furnace for melting.
Chelation
The formation to coordinate covalent bonds between a central
metal ion and a liquid that contains two or more sites for com-
bination with the metal ion.
Chemical Oxygen Demand (COD)
A measure of the oxygen-consuming capacity to the organic and
inorganic matter present in the water or wastewater.
Cold-Crucible Arc Melting
Melting and purification of metal in a cold refractory vessel or
pot.
Colloid
Suspended solids whose diameter may vary between less than one
micron and fifteen microns.
Composite Samples
A series of samples collected over a period of time but combined
into a single sample for analysis. The individual samples can be
taken after a specified amount of time has passed {time compo-
sited ), or after a specified volume of water has passed the sam-
pling point {flow composited). The sample can be automatically
488
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GENERAL DEVELOPMENT DOCUMENT SECT - XVI
collected and composited by a sampler or can be manually
collected and combined.
Consent Decree (Settlement Agreement)
Agreement between EPA and various environmental groups, as insti-
tuted by the United States District Court for the District of
Columbia, directing EPA to study and promulgate regulations for
the toxic pollutants (NRDC, Inc. v. Train, 8 ERC 2120 (D.D.C.
1976), modified March 9, 1979, 12 ERC 1833, 1841).
Contact Water
Any water or oil that comes into direct contact with the metal,
whether it is raw material, intermediate product, waste product,
or finished product.
Continuous Casting
A casting process that produces sheet, rod, or other long shapes
by solidifying the metal while it is being poured through an
open-ended mold using little or no contact cooling water. Thus,
no restrictions are placed on the length of the product and it is
not necessary to stop the process to remove the cast product.
Continuous Treatment
Treatment of waste streams operating without interruption as
opposed to batch treatment. Sometimes referred to as flow-
through treatment.
Contractor Removal
Disposal of oils, spent solutions, or sludge by a commercial
firm.
Conventional Pollutants
Constituents of wastewater as determined by Section 304(a)(4) of
the Act, including but not limited to pollutants classified as
biological-oxygen-demanding, oil and grease, suspended solids,
fecal coliforms, and pH,
Converting
The process of blowing air through molten metal to oxidize
impurities.
Cooling Tower
A hollow, vertical structure with internal baffles designed to
break up falling water so that it is cooled by upward-flowing air
and the evaporation of water.
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GENERAL DEVELOPMENT DOCUMENT SECT - XVI
Copper Matte
An impure sulfide mixture formed by smelting the sulfide ores in
coppe r.
Cupelled
Refined by means of a small shallow porous bone cup that is used
in assaying precious metals.
Cupola Furnace
A vertical cylindrical furnace for melting materials on a small
scale. This furnace is similar to a reverberatory furnace but
only on a smaller scale.
Cyclones
A funnel-shaped device for removing particulates from air or
other fluids by centrifugal means.
Data Collection Portfolio (dcp)
The questionnaire used in the survey of the nonferrous metals
manufacturing industry.
Degassing
The removal of dissolved hydrogen from the molten metal prior to
casting. This process also helps to remove oxides and impurities
from the melt.
Direct Chi 11 Casting
A method of casting where the molten metal is poured into a
water-cooled mold. The base of this mold is the top of a
hydraulic cylinder that lowers the aluminum first through the
mold and then through a water spray and bath to cause solidifica-
tion . The vertical distance of the drop limits the length of the
ingot. This process is also known as semi-continuous casting.
Direct Discharger
Any point source that discharges to a surface water.
Pore
Gold and silver bullion remaining in a cupelling furnace after
oxidized lead is removed.
Dross
Oxidized impurities occurring on the surface of molten metal.
490
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GENERAL DEVELOPMENT DOCUMENT SECT - XVI
Drying Beds
Areas for dewatering of sludge by evaporation and seepage.
Effluent
Discharge from a point source.
Effluent Limitation
Any standard (including schedules of compliance) established by a
state or EPA on quantities, rates, and concentrations of chemi-
cal, physical, biological, and other constituents that are dis-
charged from point sources into navigable waters, the waters of
the contiguous zone, or the ocean.
Electrolysis
A method of producing chemical reactions by sending electric
current through electrolytes or molten salt.
Electrolytic Refining
A purification process in which metals undergo electrolysis.
Electrolytic Slime
Insoluble impurities removed from the bottom of an electrolytic
cell during electrolytic refining.
Electron Beam Melting
A melting process in which an electron beam is used as a heating
source.
Electrostatic Precipitator (ESP)
A gas cleaning device that induces an electrical charge on a
solid particle which is then attracted to an oppositely charged
collector plate. The collector plates are intermittently
vibrated to discharge the collected dust to a hopper.
End-of-Pipe Treatment
The reduction of pollutants by wastewater treatment prior to dis-
charge or reuse.
Film Stripping
Separation of silver-bearing material from scrap photographic
film.
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GENERAL DEVELOPMENT DOCUMENT SECT - XVI
GENERAL DEVELOPMENT DOCUMENT SECT - XVI
Non-Water Quality Environmental Impact
The ecological impact as a result to solid, air, or thermal pol-
lution due to the application to various wastewater technologies
to achieve the effluent guidelines limitations. Also associated
with the non-water quality aspect is the energy impact of waste-
water treatment.
NPDES Permits
Permits issued by EPA or an approved state program under the
National Pollutant Discharge Elimination System as required by
the Clean Water Act.
Off-Gases
Gases, vapors, and fumes produced as a result of a metal forming
operation.
Oil and Grease (O&G)
Any material that is extracted by freon from an acidified sample
and that is not volatilized during the analysis, such as hydro-
carbons, fatty acids, soaps, fats, waxes, and oils.
Outokumpu Furnace
A furnace used for flash smelting, in which hot sulfide concen-
trate is fed into a reaction shaft along with preheated air and
fluxes. The concentrate roasts and smelts itself in a single
autogeneous process.
Parke's Process
A process in which zinc is added to molten lead to form insoluble
zinc-gold and zinc-silver compounds. The compounds are skimmed
and the zinc is removed through vacuum de-zincing.
Pelletized
An agglomeration process in which an unbaked pellet is heat
hardened. The pellets increase the reduction rate in a blast
furnace by improving permeability and gas-solid contact.
EM
The pH is the negative logarithm of the hydrogen ion activity of
a solution.
Platinum Group Metals
A name given to a group of metals comprised of platinum,
palladium, rhodium, iridium, osmium, and ruthenium.
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GENERAL DEVELOPMENT DOCUMENT SECT - XVI
Pollutant Parameters
Those constituents of wastewater determined to be detrimental
and, therefore, requiring control.
Precious Metals
A generic term referring to the elements gold, silver, platinum,
palladium, rhodium, iridium, osmium, and ruthenium as a group.
Precipitation Supernatent
A liquid or fluid forming a layer above precipitated solids.
Priority Pollutants
Those pollutants included in Table 2 of Committee Print number
95-30 of the "Committee on Public Works and Transportation of the
House of Representatives," subject to the Act.
Process Water
Water used in a production process that contacts the product, raw
materials, or reagents.
Production Normalizing Parameter (PNP)
The unit to production specified in the regulations used to
determine the mass of pollution a production facility may
discharge.
PSES
Pretreatment standards (effluent regulations) for existing
sources applicable to indirect dischargers.
PSNS
Pretreatment standards (effluent regulations) for new sources
applicable to new indirect dischargers.
Publicly Owned Treatment Works (PQTW)
A waste treatment facility that is owned by a state or
municipality.
Pug Mill
A machine for mixing and tempering a plastic material by the
action to blades revolving in a drum or trough.
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GENERAL DEVELOPMENT DOCUMENT SECT - XVI
Pyr©metallurgical
GENERAL DEVELOPMENT DOCUMENT SECT - XVI
Surface Water
Any visible stream or body of water, natural or man-made. This
does not include bodies of water whose sole purpose is wastewater
retention or the removal of pollutants, such as holding ponds or
lagoons.
Surfactants
Surface active chemicals that tend to lower the surface tension
between liquids.
Sweating
Bringing small globules of low-melting constituents to an alloy
surface during heat treatment.
Total Dissolved Solids (TPS)
Organic and inorganic molecules and ions that are in true solu-
tion in the water or wastewater.
Total Organic Carbon (TOC)
A measure of the organic contaminants in a wastewater. The TOC
analysis does not measure as much of the organics as the COD or
BOD tests, but is much quicker than these tests.
Total Recycle
The complete reuse of a stream, with make-up water added for
evaporation losses. There is no blowdown stream from a totally
recycled flow and the process water is not periodically or con-
tinuously discharged.
Total Suspended Solids (TSS)
Solids in suspension in water, wastewater, or treated effluent.
Also known as suspended solids.
Traveling Grate Furnace
A furnace with a moving grate that conveys material through the
heating zone. The feed is ignited on the surface as the grate
moves past the burners; air is blown in the charge to burn the
fuel by downdraft combustion as it moves continuously toward
discharge.
Tubing Blank
A sample taken by passing one gallon to distilled water through a
composite sampling device before initiation of actual' wastewater
sampling.
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GENERAL DEVELOPMENT DOCUMENT SECT - XVI
Tuyere
Openings in the shell and refractory lining of a furnace through
which air is forced.
Vacuum Dezincing
A process for removing zinc from a metal by melting or heating
the solid metal in a vacuum.
Venturi Scrubbers
A gas cleaning device utilizing liquid to remove dust and mist
from process gas streams.
Volatile Substances
Materials that are readily vaporizable at relat ively low
temperatures.
Wastewater Discharge Factor
The ratio between water discharged from a production process and
the mass of product of that production process. Recycle water in
not included.
Water Use Factor
The total amount of contact water or oil entering a process
divided by the amount of product produced by this process. The
amount of water involved includes the recycle and make-up water.
Wet Scrubbers
Air pollution control devices used for removing pollutants as the
Igas passes through the spray.
Zero Discharger
Any industrial or municipal facility that does not discharge
wastewater.
The following sources were used for defining terms in the
glossary:
Gill, G. 1., Nonferrous Extractive Metallurgy. John Wiley &
Sons, New York, NY, 1980.
Lapedes, Daniel N., Dictionary of Scientific and Technical Terms,
2nd edition. New York, NY, McGraw-Hill Book Co., 1978.
McGannon, Harold E., The Making, Shaping, and Treating of Steel,
9th edition. Pittsburgh, PA, U.S. Steel Corp., 1971.
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