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Section IV
INDUSTRY SUBCATEGORIZATION
In developing regulations for the nonferrous metals forming
category, the Agency considered whether different effluent limi-
tations and standards are appropriate for different segments of
the category. The regulations are technology based. If uniform
regulations are to be applied to the entire category, the tech-
nology upon which they are based must be available and appropri-
ate for every segment of the category. If not, subcategoriza-
tion is required. Subcategorization is also appropriate if
different pollutants are regulated in various segments of the
category.
EPA considers several factors to determine the appropriate sub-
categorization of a category. These include plant location and
nonwater quality environmental impacts, including energy costs
and solid waste generation. These factors affect the availabil-
ity of wastewater treatment technology. Other Subcategorization
factors which must be considered are raw materials, manufacturing
processes, products manufactured, plant size and age, and process
water use. These factors may influence wastewater characteris-
tics and thus determine the appropriateness of wastewater treat-
ment technologies and the presence of pollutants to be regulated.
EVALUATION AND SELECTION OF SUBCATEGORIZATION FACTORS
Factors Considered
The analysis of potential Subcategorization factors was carried
out in the context of the scope of the nonferrous metals forming
category. The manufacturing activities included in the category
are:
1. Forming of nonferrous metals other than copper and
aluminum by rolling, drawing, extruding, and forging
operations;
2. Production of ferrous and nonferrous metal powders;
3. Production of ingots and metal parts from ferrous and
nonferrous metal powders; and
4. Production of clad metals and bimetallics from
nonferrous metals other than copper and aluminum.
379
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The following factors were considered as a basis for subcategori-
zation:
1. Metal formed and raw materials used;
2. Manufacturing processes;
3. Products manufactured;
4. Process water use;
5. Plant size;
6. Plant age;
7. Plant location;
8. Solid waste generation and disposal, air emissions,
and energy usage; and
9. Individual waste streams generated by manufacturing
activities.
In addition to considering how the individual factors influenced
siibcategorization, the interrelationship between different fac-
tors was evaluated. An evaluation of these factors is presented
below.
Metal Formed and Raw Materials Used. The raw materials used in
the nonferrous metalsforming category can be classified as
follows:
Metal and metal alloys;
Lubricants and additives to lubricants; and
Surface treatment, degreasing, and furnace fluxing
chemicals.
The pollutants discharged from a particular forming operation are
dependent on the metal formed and other raw materials used in
that operation. For example, nickel forming wastewater will
contain nickel and any lubricants or surface treatment chemicals
used in forming and associated process steps. Nickel is probably
present in all nickel forming wastewater but the presence of
other pollutants varies from plant to plant and operation to
operation.
All of the manufacturing activities in this category, with the
exception of metal cladding, can easily be divided into subcate-
gories according to the metal formed. The metal formed and the
metallurgical properties that are required in the final product
will determine the other raw materials used during the forming
process itself and associated process steps. The metal formed
will also determine the manufacturing processes used, the
products manufactured, and the amount and type of process water
use.
Because the type of metal formed will have a major impact on
wastewater flow and characteristics, subcategorization of manu-
facturing activities by the type of metal formed is appropriate.
380
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Additionally, if two or more metals are formed by identical or
very similar operations, generating wastewaters of similar
characteristics, it is appropriate to group the metals into one
subcategory. One such grouping is the precious metals (gold,
silver, platinum, and palladium).
Pollutants generated by the production of clad metals and
bimetallics are dependent on the metals processed, just as are
discharges from other nonferrous metals forming processes.
However, because cladding involves more than one type of metal,
the categorization of this forming operation in a subcategoriza-
tion scheme based on the type of metal formed is not straight-
forward.
Of the 22 surveyed plants which reported clad metal production,
15 apply precious metal to a base metal. These plants use very
similar manufacturing operations and similar materials. Typi-
cally a gold or silver overlay or inlay is roll-bonded to a
copper-alloy base. Nickel and stainless steel are also used as
base metals.
The cladding of precious metals to base metals is closely asso-
ciated with precious metal forming. All but three of the 15
plants engaged in precious metal cladding also reported forming
precious metals. The clad metals are formed by the same tech-
niques and on the same equipment as pure metals. Therefore, it
is appropriate to group precious metal cladding with precious
metals forming.
Three plants reported cladding nonferrous metals other than pre-
cious metals to base metals in processes generating wastewater.
Just as cladding precious metals to base metal can be grouped
with precious metal forming, other cladding operations can be
grouped with the forming of the surface metal of the clad prod-
uct. For example, manufacture of nickel clad molybdenum would be
considered nickel forming but manufacture of molybdenum clad
nickel would be considered molybdenum forming.
The Agency does not consider the type of lubricant or surface
treatment, degreasing, and furnace fluxing chemicals to have a
major, organizing impact on the category's wastewater character-
istics. Subcategorization based on these raw materials would not
adequately distinguish the type of pollutants likely to be pres-
ent in waste streams from the resulting subcategories. For
instance, beryllium is likely to be present in wastewater gener-
ated from surface treatment of beryllium but is not expected to
be present in nickel surface treatment wastewater. Thus, raw
materials other than the metal formed are not appropriate
Subcategorization criteria.
381
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Manufacturing Processes. As discussed above, there are four
major manufacturing activities included in the nonferrous metals
forming category, each of which uses one or more distinct manu-
facturing processes. Subcategorization on the basis of manufac-
turing process would group all rolling operations, all drawing
operations, all extrusion operations, etc., together. The Agency
does not believe this is an appropriate basis for subcategoriza-
tion because it does not adequately distinguish the type of pol-
lutants likely to be present in waste streams from the resulting
subcategories. For instance, lead is likely to be present in
lead rolling wastewater but is not expected to be present in
nickel rolling wastewater.
Products Manufactured. Another approach is subcategorization
based on the products manufactured, as listed below:
Product
Plate
Sheet
Strip
Foil
Rod and bar
Tubing
Wire and cable
Other (L shapes, I-beams, etc)
Clad metals
Metal powders
Miscellaneous shapes
Associated
Manufacturing Process
Rolling
Rolling
Rolling
Rolling
Rolling, extrusion, drawing
Extrusion or drawing
Drawing or extrusion
Drawing or extrusion
Roll bonding, solder
application, explosion
bonding, co-drawing
Water atomization, gas
atomization, grinding, etc.
Forging, powder metallurgy
The product manufactured would be an excellent basis for subcate-
gorization if waste characteristics and the process to produce a
given item were the same from plant to plant; however, this is
not true for many formed metal products. For example, rods can
be produced by two different production processes which generate
similar wastewater (i.e., rolling and drawing), but the mass of
pollutants generated per unit of rod produced by rolling will be
different than the amount generated by drawing the rod. Further-
more, rods formed from different metals but produced by the same
process may use different lubricants, therefore generating a
waste with different characteristics. Because the type and mass
of pollutant generated per unit of product will be different
depending on the metal formed and type of forming operation^
employed, the type of products manufactured is an inappropriate
basis for subcategorizing the nonferrous metals forming category.
382
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Process Water Use. Major differences in water use (volume of
water applied to a process per mass of product) between facili-
ties with large and small production could be considered as a
factor in the development of subcategories.
A high water use per mass of product from a particular operation
would lead to a waste stream with lower pollutant concentration
than a lower production normalized water use (assuming the mass
of pollutant generated in a given process is dependent on the
mass of material processed). The differences in pollutant con-
centration may lead to differences in wastewater treatability and
required treatment technology. If the differences in process
water use are related to total plant production (if, for example,
small production requires a large amount of process water,
resulting in high production normalized water use and a low
pollutant concentration), process water use could be a basis for
subcategorization.
However, as will be discussed in Section V, analysis of the data
indicates that production normalized water use (i.e., gallons per
ton of metal formed) for a given unit operation is usually
independent of production volume. For example, a large direct
chill casting operation will use about the same amount of water
per ton of ingot produced as an operation casting much less
nonferrous metal by the same method. Production normalized water
use appears to be relatively constant over a wide range of pro-
ductions and therefore process water use is not an appropriate
parameter for subcategorization.
Plant Size. The number of employees and amount of metal pro-
cessed can be used as relative measures of the size of nonferrous
metals forming plants.
Wastewaters produced by a production process are largely indepen-
dent of the number of plant employees. Variations in staff occur
for many reasons, including shift differences, clerical and
administrative support, maintenance workers, efficiency of plant
operations, and market fluctuations. Due to these and other
factors, the number of employees is constantly fluctuating, mak-
ing it difficult to develop a correlation between the number of
employees and wastewater generation.
Subcategorization based on size in terms of production of non-
ferrous metals would group plants by the off-pounds of extru-
sions, sheets, rods, etc. This method of subcategorization does
not adequately distinguish between waste streams of differing
treatability nor does it determine a given plant's ability to
achieve effluent limitations.
Subcategorization based on size in terms of volume of wastewater
generated would be appropriate if the applicability of a parti-
cular treatment technology was dependent on the volume of water
383
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to be treated. However, this is not the case for wastewater
generated in the nonferrous metals forming category.
For the reasons discussed above, subcategorization on the basis
of size (number of employees, production, or volume of wastewater
generated) is not appropriate.
Plant Age. Most nonferrous metals forming plants have been built
in the past 30 years. Since metal forming technologies are
developing and changing rapidly, most plants have also been mod-
ernized frequently in order to remain economical. Therefore,
determination of a particular plant's technological age is very
difficult. Accordingly, plant age is not an appropriate basis
for subcategorization.
The potential subcategorization schemes presented above attempt
to create subcategories with similar waste characteristics.
Other factors which may affect 'the availability of wastewater
treatment technology must also be evaluated.
Plant Location. The geographical distribution of the nonferrous
metalsforming plants which responded to the dcp is presented in
Figure III-l. The plants are not limited to any one geographical
location, but they are generally located east of the Mississippi
River. Although some cost savings may be realized for facilities
located in nonurban settings where land is available to install
lagoons, equivalent control of wastewater pollutant discharge can
be achieved by urban plants with the use of physical and chemical
treatment systems that have smaller land requirements. Since
most plants are located in the eastern part of the United States
(an area where precipitation exceeds evaporation) or in urban
areas, evaporation and land application of the wastewater are not
commonly used. Thus, location does not appear to be a signifi-
cant factor on which to base subcategorization.
Solid Waste Generation and Disposal, Air Emissions and Energy
Usage.Certain manufacturingplantsmay belimitedin the waste-
water treatment technology available to them by their patterns of
solid waste generation and disposal, air emissions or energy us-
age. However, after a review of all available information, the
Agency was unable to identify any plant or type of plant which
has any unusual energy requirements or any unusual limitations in
available energy, solid waste disposal, or air emissions.
Individual Waste Streams Generated by Manufacturing Activities.
Most of the potential subcategorization schemes described above
attempt to create subcategories with similar waste characterist-
ics. An alternative to subcategorizing by a factor which only
indirectly influences wastewater characteristics is to consider
384
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each waste stream (such as nickel rolling spent emulsions, lead
shot casting contact cooling water, etc.) a separate subcategory.
The waste streams generated by the manufacturing activities
included in the nonferrous metals forming category are presented
in Section V of this document.
Use of this scheme will yield subcategories of homogeneous char-
acter and treatability. The principal benefit from using waste
streams as a basis for subcategorization is that an appropriate
effluent limitation or standard could be established for each
stream. For each regulated pollutant, a specific pollutant mass
discharge value could be calculated for each waste stream present
at the facility. These values would be summed to determine the
total mass discharge allowed for that pollutant at that facility.
The difficulties with this approach are the large number of sub-
categories - approximately 175 - that it would generate. The
Agency believes that a guideline with this many subcategories
would be extremely difficult to administer. However, waste
stream by waste stream analysis of production, flow, and
pollutants present was used to calculate pollutant mass
limitations for each subcategory.
Summary of Subcategorization
The nonferrous metals forming category can be subcategorized on
the basis of metal type formed. Based on information reported by
294 surveyed plants, 11 subcategories which have plants that
discharge process water to surface waters or a POTW can be
established. These subcategories are:
o Lead/Tin/Bismuth Forming,
o Nickel/Cobalt Forming,
o Zinc Forming,
o Beryllium Forming,
o Precious Metals Forming,
o Iron and Steel/Copper/Aluminum Metal Powder Production
and Powder Metallurgy
o Titanium Forming,
o Refractory Metals Forming,
o Zirconium/Hafnium Forming,
o Magnesium Forming, and
o Uranium Forming.
The iron and steel/copper/aluminum metal powder production and
powder metallurgy subcategory includes only manufacturing opera-
tions which involve metal powders. Forming of these metals is
covered by separate regulations. [iron and Steel, 40 CFR Part
420; Copper Forming, 40 CFR Part 468 (48 FR 36942, August 15,
1983); Aluminum Forming, 40 CFR Part 467 (48 FR 49126, October
24, 1983).]
385
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PRODUCTION NORMALIZING PARAMETER SELECTION
The objective of effluent limitations and standards is to reduce
the total quantity of pollutants discharged into surface waters.
Because plants could meet a concentration-based standard by dilu-
tion rather than treatment, mass limitations have been developed
for the nonferrous metals forming industry. In order for regula-
tions to be equitable for plants with large productions and. small
productions, the mass limitations must be normalized by an appro-
priate unit of production called a production normalizing param-
eter (PNP). That is, pollutant discharge limitations are written
as allowable mass of pollutant discharge per PNP (mg/PNP).
Therefore, for a PNP to be appropriate, mg/PNP must be indepen-
dent of both production and wastewater volume, for a particular
waste stream. Mass of metal, number of pieces, surface area, and
mass of process chemicals used were considered as possible PNP's.
An evaluation of these alternatives follows.
Mass of Metal Processed. The nonferrous metals forming category
typically maintains production records of the pounds of metal
processed. Availability of these production data and lack of
data for other production parameters, such as number of pieces
produced, makes this the most convenient parameter to use. The
nonferrous metals forming dcp requested three production values:
the capacity production rate for specific unit operations, the
average production rate for 1981 in off-lbs/hr, and the total
off-pounds of final product formed in 1981. A PNP based on mass
of metal processed would use the average production rates
reported in the dcp.
Number of Pieces Processed. The number of pieces processed by a
given plant would not account for the variations in size and
shape typical of formed products. Forgings, for instance, are
produced in a wide range of sizes. It would be unreasonable to
expect the quenching of a large forging to use the same amount of
water required for a smaller forged product and yield a constant
mass of pollutant per piece. Therefore, the Agency concluded
that the number of pieces processed is not an appropriate PNP.
Surface Area of Metal Processed. Surface area may be an appro-
priate production normalizing parameter for formed metal which is
rinsed (i.e., the mass of pollutants generated may correlate with
surface area). However, the mass of pollutants generated by
other metal forming operations, such as cooling, is unrelated to
surface area. Hence, surface area might be an adequate PNP for
some processes but would be wholely inappropriate for others. In
addition, records of the area of metal processed are not gen-
erally kept by industry. In some cases, such as forging of
miscellaneous shapes, surface area would be very difficult to
386
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determine. In any case, surface area data would be difficult to
collect. For these reasons, surface area is an inappropriate PNP
for the nonferrous metals forming category.
Mass of Process Chemicals Used. The mass of pollutants dis-
charged is more dependent on the processes which the metal under-
goes than on the amount of process chemical used in the process.
Some operations, such as heat treatment with contact cooling
water, generate pollutants but do not use any process chemicals.
In addition, the use of this parameter as the production normal-
izing parameter would tend to discourage regeneration and reuse
of process chemicals. For these reasons, mass of process chemi-
cals used is an inappropriate PNP for the nonferrous metals
forming category.
Selection of the Production Normalizing Parameter
For the reasons outlined above, the Agency has selected mass of
product formed as the most appropriate PNP. The mass of pollu-
tants can be related to the mass of metal processed and most
companies keep production records in terms of mass.
The PNP for nonferrous metals forming is "off-kilograms" or the
kilograms of product removed from a machine at the end of a pro-
cess cycle. For example, in the rolling process, an ingot enters
the mill to be processed. Following one process cycle which may
substantially reduce the ingot's thickness, the metal is removed
from the rolling mill where it may be processed through another
operation, such as annealing, sizing, cleaning, or it may simply
be stored before being brought back to the rolling mill for
another process cycle, further reducing the thickness. The mass
of metal removed from the rolling mill after each process cycle
multiplied by the number of process cycles is the PNP for that
process.
DESCRIPTION OF SUBCATEGORIES
The nonferrous metals forming category was divided into 11 sub-
categories, based on type of metal formed. Five of these sub-
categories cover forming operations for more than one metal.
This subcategorization allows separate limitations to be estab-
lished for groups of metals whose wastewater is similar, are
formed by similar processes, and would be expected to utilize
similar or identical wastewater treatment within the subcategory.
The iron and steel/copper/aluminum metal powder production and
powder metallurgy subcategory covers only metal powder production
and production of iron, copper, and aluminum metal parts from
powder. All other subcategories cover traditional forming opera-
tions (rolling, drawing, extruding, forging), powder metallurgy
387
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processes (powder production and compaction), and ancillary oper-
ations integral to the production of formed metal (heat treat-
ment, chemical and mechanical surface treatment, and casting).
Cladding operations are included in the subcategory of the
surface metal of the clad product.
The number of surveyed plants in each subcategory and the number
of plants in each subcategory discharging process wastewater
(directly to surface streams and to a POTW; are listed in Table
IV-1.
Lead/Tin/Bismuth Forming. This subcategory includes the pro-
duction of three major products: bullets, made by extrusion and
swaging lead; solder, formed by extrusion and drawing of lead,
tin, and bismuth in various alloy combinations; and insulated
cable, in which lead is extruded over copper cable. Smaller
amounts of lead sheet and pipe are produced by rolling and
extrusion, respectively.
Of the surveyed plants, 63 form lead. Twenty-one of these plants
discharge process wastewater, three directly to surface water and
18 to a POTW.
Nickel/Cobalt Forming. Nickel and cobalt are formed by rolling,
drawing, extrusion, and forging, with extrusion the least common
forming process. The two metals were grouped together because
the metals are formed by identical processes. Also, 15 of the 16
surveyed plants which form cobalt also form nickel.
Of the surveyed plants, 73 form nickel and/or cobalt, making this
the largest subcategory in the category. Forty-two plants dis-
charge process wastewater, 14 directly to surface water, 26 to a
POTW, and two both directly and to a POTW.
Zinc Forming. Zinc is formed by rolling, drawing, and forging.
It is surface treated and cleaned with alkaline detergents
following forming. Ten of the surveyed plants form zinc. Three
plants discharge process wastewater, one directly to surface
water and two to a POTW.
Beryllium Forming. After pressing beryllium powder into bricks,
the metal is sintered, and rolled to sheet between sheets of
stainless steel. Billets and sheets are pickled in acid and
rinsed with water. One surveyed plant forms beryllium amd it
discharges process wastewater directly to surface water.
Precious Metal Forming. This subcategory includes manufacturing
processes used to form gold, silver, platinum, and palladium.
The Agency believes that it would be very difficult to subcate-
gorize by the individual precious metals because most plants in
338
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this subcategory form all of the precious metals using the same
equipment and cleaning operations. In addition, the metals are
alloyed with each other in many combinations, some of which have
no one constituent that is greater than 50 percent of the alloy.
As described above, this subcategory also includes production and
forming of clad precious metals.
The most common forming operations are rolling and drawing.
Extrusion and forging are practiced to a much smaller extent.
Fifty of the surveyed plants form precious metals. Thirty-four
of these plants discharge process water, six directly to surface
water, 27 to a POTW, and one both directly and to a POTW.
Iron and Steel/Copper/Aluminum Metal Powder Production and Metal
Powder Metallurgy.Thissubcategoryincludesoperationsfor
producing metal powders and metal parts from powder for iron,
steel, copper, and aluminum. Powders are produced by wet or dry
atomization and mechanical grinding. Pressing and sintering, the
major manufacturing processes in powder metallurgy, usually use
no process water. Most of the wastewater from operations in this
subcategory is generated by post-forming surface treatment.
Sixty surveyed plants are engaged in powder production or powder
metallurgy of iron, steel, copper, or aluminum. Twenty-three of
these plants discharge process wastewater, three directly to
surface water and 20 to a POTW.
Titanium Forming. Titanium is formed by rolling, drawing, extru-
sion, and forging. Forging is practiced by many plants, many of
which primarily forge steel. Rolling is the second most common
forming operation, drawing the least. Titanium is often acid
etched to remove a hard surface layer which forms at elevated
temperatures.
Forty-one of the surveyed plants form titanium. Twenty-seven of
these plants discharge process wastewater, 11 directly to surface
streams, 15 to a POTW, and one both directly and to a POTW.
Refractory Metal Forming. This subcategory includes processes
used to form molybdenum, tungsten, vanadium, rhenium, tantalum,
and columbium. The Agency believes that it is unnecessary to
subcategorize by the individual refractory metals. The metals
are processed and fabricated by similar methods because of their
common characteristics. The end product of refining these metals
is metal powder which is consolidated into finished products or
mill shapes. Only production of metal powders, ferrous and non-
ferrous, in operations which do not significantly increase their
purity are included in this category. Production of nonferrous
metals powders in operations which significantly increase their
389
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purity is covered by the guidelines for nonferrous metals manu-
facturing, 40 CFR Part 421 (phase I, proposed at 40 CFR 7032,
February 17, 1983, to be promulgated shortly; and phase II,
scheduled for proposal shortly). The powders can also be arc or
electron beam melted and cast into ingots. The mill shapes and
ingots are shaped into finished form by rolling, drawing,
extruding, and forging. A second reason that subcategorization
by individual refractory metal is unnecessary is that most of the
plants which form one refractory metal also form one or more
other refractory metals and waste streams are commonly
commingled.
Fifty-two of the surveyed plants reported forming one or more of
the refractory metals. Thirty-five of these plants discharge
process wastewater, six directly to surface streams, 27 to a
POTW, and two both directly and to a POTW.
Zirconium/Hafnium Forming. Zirconium and hafnium are formed by
rolling, drawing, and extrusion. One common manufacturing
process is tube-reducing (roll-rocking or pilgering), a special
type of cold rolling. Post-forming operations include annealing
and sand blasting (dry), acid and alkaline cleaning, and conver-
sion coating. All of the plants which form hafnium also form
zirconium by similar processes.
Ten of the surveyed plants report forming zirconium. Seven of
these plants discharge process wastewater, three directly to
surface water, three to a POTW, and one both directly and to a
POTW.
Magnesium Forming. Magnesium forming processes consist of forg-
ing, rolling, and extrusion. Water is used in post-extrusion
etching, chromating, and rinsing processes. Eight of the sur-
veyed plants form magnesium. Five plants discharge process
water, three directly to surface streams and two to a POTW.
Uranium Forming. Uranium forming processes consist of forging
and extrusion, both of which use contact cooling water. Water
is also used in post-forming surface treatment steps. Three sur-
veyed plants report forming uranium. One plant discharges
process water directly to a surface stream and one both directly
and to a POTW.
390
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SECTION V
WATER USE AND WASTEWATER CHARACTERISTICS
This section presents a summary of the analytical data that char-
acterize the raw wastewater in the category. Flow data that
serve as the basis for developing regulatory flow allowances in
the nonferrous metals forming category are also summarized in
this section. The analytical and flow data were obtained from
four sources: information obtained during a telephone survey;
data collection portfolios (dcp's); sampling and analysis pro-
grams; and long-term or historical data. Confidential informa-
tion was handled in accordance with 40 CFR Part 2.
DATA SOURCES
Telephone Survey
As described in Section III of this document, a comprehensive
telephone survey was undertaken in order to determine which
plants should comprise a final dcp mailing list, i.e., whether or
not operations within the scope of this category were present at
the plants contacted. In the telephone survey, the contact at
each plant was asked what metals were formed, the type of forming
operations the plant employed, i.e., rolling, drawing, extruding,
forging, casting, cladding, or powder metallurgy and their asso-
ciated water usage, discharge, and treatment-in-place. The plant
contact was also asked what surface treatment, cleaning, washing,
and/or rinsing operations were utilized and their associated
water usage, discharge, and treatment-in-place. In addition to
the telephone contacts made during the comprehensive survey, many
plants were contacted by telephone to clarify dcp responses.
Data Collection Portfolios
Data collection portfolios (dcp's) are questionnaires which were
developed by the Agency to obtain extensive data from plants in
the nonferrous metals forming category. The dcp's, sent to all
facilities known or believed to be engaged in nonferrous metals
forming, requested information under the authority of Section 308
of the Clean Water Act. The information requested included plant
age, production, number of employees, water usage, manufacturing
processes, raw material and process chemical usage, wastewater
treatment technologies, and the presence (known or believed) of
toxic pollutants in the plant's raw and treated process
wastewaters.
Complete dcp responses supplied the following information for
each operation present at the responding plant: the total
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production in 1981, the average production rate (Ib/hr), produc-
tion rate at full capacity, and the quantity and rate of waste-
water discharge. As discussed in Section IV, a mass-based
regulation must relate water use and raw waste characteristics to
some production normalizing parameter. The average production
rate is considered to be the parameter most applicable to opera-
tions in this category, and has been used to normalize the water
and wastewater flows discussed in this section.
Two production normalized flows (PNF's) were calculated for each
operation reported in the dcp's. The first is production normal-
ized water use, defined as the volume of water or other fluid
(e.g., emulsions, lubricants) required per mass of metal pro-
cessed through the operation. Water use is based on the sum of
recycle and make-up flows to a given process. The second PNF
calculated for each operation is production normalized water
discharge, defined as the volume of wastewater discharged from a
given process to further treatment, disposal, or discharge per
mass of nonferrous metal processed. Differences between the
water use and wastewater flows associated with a given stream
result from recycle, evaporation, and carryover on the product.
The production values used in calculation correspond to the
production normalizing parameter, PNP, assigned to each stream,
as outlined in Section IV.
The production normalized flows from similar sources were com-
piled and statistically analyzed. Wastewater sources with
similar production normalized flows and physical and chemical
characteristics were grouped together (e.g., spent baths from
acid pickling, acid etching, chromating and phosphating were
grouped together as "surface treatment spent baths."). These
groupings are referred to as "waste streams" in this document.
It should be noted that one nonferrous metals forming or asso-
ciated operation can generate more than one waste stream. Each
distinct waste stream will have different production normalized
flows, physical and chemical characteristics, or both. The pro-
duction normalized flow information for each waste stream is
presented in the administrative record which accompanies this
rulemaking package. An analysis of factors affecting the waste-
water flows is presented in Sections IX, X, XI, and XII where
representative BPT, BAT, NSPS, and pretreatment discharge flow
allowances are selected for use in calculating the effluent
limitations and standards.
Sampling and Analysis Program
The sampling and analysis program was undertaken primarily to
identify pollutants of concern in the industry, with emphasis on
toxic pollutants. Samples were collected at 17 nonferrous metals
forming facilities.
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This section summarizes the activities undertaken during the sam-
pling trips and identifies the types of sites sampled and param-
eters analyzed. It also presents an overview of sample collec-
tion, preservation, and transportation techniques. Finally, it
describes the pollutant parameters quantified, the methods of
analyses and laboratories used, the detectable concentration of
each pollutant, and the general approach used to ensure the
reliability of the analytical data produced.
Site Selection. Seventeen plants engaged in manufacturing opera-
tions included in this category were sampled. Four of these
plants were sampled in data gathering efforts supporting the
development of guidelines for other industrial categories
(nonferrous metals manufacturing and battery manufacturing).
Information on nonferrous rnetals forming operations was collected
incidentally to the major sampling effort at these plants. Thir-
teen plants were sampled specifically to gather data to support
guidelines and standards for this category. These plants were
selected to be representative of the industry, based on informa-
tion obtained during the telephone survey. 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, and wastewater treatment-in-place. With the exception of
the uranium forming subcategory, at least one plant in every
subcategory was sampled. Two plants provided data for more than
one subcategory.
As indicated in Table V-l, the plants selected for sampling were
typically plants with multiple forming operations and associated
surface and heat treatment operations. The flow rates and pollu-
tant concentrations in the wastewaters discharged from the manu-
facturing operations at these plants are believed to be repre-
sentative of the flow rates and pollutant concentrations which
would be found in wastewaters generated by similar operations at
any plant in the nonferrous metals forming industry. The 17
sampled plants have a variety of treatment systems in place,
ranging from plants with no treatment to plants using the
advanced technologies considered as the basis for regulation.
Field Sampling. After selection of the plants to be sampled^
each plant was contacted by telephone, and sent a letter notify-
ing the plant when a visit would be expected as authorized by
Section 308 of the Clean Water Act. In most cases, a preliminary
visit was made to the plant to select the sources of wastewater
to be sampled. The sample points included, but were not limited
to, untreated and treated discharges, process wastewater, par-
tially treated wastewater, and intake water. The actual sampling
visit was also scheduled during the preliminary visit.
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Sample Collection, Preservation, and Transportation. Collection,
preservation,and transportation of samples were accomplished 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), and in the proposed
304(h) methods (44 FR 69464, December 3, 1979). The procedures
are summarized in the paragraphs that follow.
Whenever practical, samples 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 on-site.
Each large composite (Type 1) sample was collected in a 9-liter,
wide-mouth pickle jar that had been washed with detergent and
water, rinsed with tap water, rinsed with distilled water, and
air dried at room temperature.
Before collection of Type 1 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 com-
pounds and brought to the sampling site from the analytical
laboratory, were pumped through the sampler and its attached
tubing; the water was then discarded.
A blank (control sample) was produced by pumping an additional 2
liters of blank water through the sampler and into the original
blank water bottle. The blank sample was sealed with a Teflon®-
lined cap, labeled, and packed in ice in a plastic foam-insulated
chest. This sample was subsequently analyzed to determine any
contamination contributed by the automatic sampler.
During collection of each Type 1 sample, the pickle jar was
packed in ice in a plastic foam-insulated container to cool the
sample. After the complete composite sample had been collected,
it was mixed and a 1-liter aliquot to be used for metals analysis
was dispensed into a plastic bottle. The aliquot was preserved
on-site by the addition of nitric acid to pH less than 2. Metals
samples were stored at room temperature until the end of the
sampling trip at which time they were shipped to the appropriate
laboratory for analysis.
After removal of the 1-liter metals aliquot, the balance of the
composite sample was divided into aliquots to be used for analy-
sis of nonvolatile organics, conventional parameters, and noncon-
ventional parameters. If a portion of the composite sample was
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requested by a representative of the sampled plant for indepen-
dent analysis, an aliquot was placed in a sample container
supplied by the representative.
Water samples to be analyzed for cyanide, total phenol, oil and
grease, and volatile organics were not obtained from the compos-
ite sample. Water samples for these analyses were taken as
one-time grab samples during the time that the composite sample
was collected.
The cyanide, total phenol, and oil and grease samples were stored
in new bottles which had been iced and labeled, 1-liter (33.8
ounce) plastic bottles for the cyanide sample, 0.95-liter (1
quart) amber glass bottles for the total phenol sample, and
0.95-liter (1 quart) wide-mouth glass bottles with a Teflon® lid
liner for the oil and grease sample. The samples were preserved
as described below.
Sodium hydroxide was added to each sample to be analyzed for
cyanide, until the pH was elevated to 12 or more (as measured
using pH paper). Where the presence of chlorine was suspected,
the sample was tested for chlorine (which would decompose most of
the cyanide) by using potassium iodide/starch paper. If the
paper turned blue (indicating chlorine was present), 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
the sample bottle was sealed (by a Teflon®-lined cap), labeled,
iced, and shipped for analysis.
Sulfuric acid was added to each sample to be analyzed for total
phenol, until the pH was reduced to 2 or less (as measured using
pH paper). The sample bottle was sealed, labeled, iced, and
shipped for analysis.
Sulfuric acid was added to each sample to be analyzed for oil and
grease, until the pH was reduced to 2 or less (as measured using
pH test paper). The sample bottle was sealed (by a Teflon® lid
liner), labeled, iced, and shipped for analysis.
Each sample to be analyzed for volatile organic pollutants was
stored in a new 125-ml (4.2-ounce) glass bottle that had been
rinsed with tap water and distilled water, heated to 105°C
(221°F) for one hour, and cooled. This method was also used to
prepare the septum and lid for each bottle. When used, each
bottle was filled to overflowing, sealed with a Teflon®-faced
silicone septum (Teflon® side down), capped, labeled, and iced.
Hermetic sealing was verified by inverting and tapping the sealed
container to confirm the absence of air bubbles. (If bubbles
were found, the bottle was opened, a few additional drops of
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sample were added, and a new seal was installed.) Samples were
maintained hermetically sealed and iced until analyzed.
Sample Analysis. Samples were sent by air to one of the labora-
tories listed in Table V-2. The samples were analyzed for 21
metals, including seven of the priority metal pollutants (beryl-
lium, cadmium, chromium, copper, nickel, lead, and zinc) using
inductively-coupled argon plasma emission spectroscopy (ICAPES)
as proposed in 44 FR 69464, December 3, 1979. The remaining six
priority metal pollutants, with the exception of mercury, were
analyzed by atomic absorption spectroscopy (AA) as described in
40 CFR Part 136. Mercury analysis was performed by automated
cold vapor atomic absorption. Analysis for the seven toxic
metals analyzed by ICAPES was also performed by AA on 10 percent
of the samples to determine test comparability. Because the
results showed no significant differences in detection or quanti-
fication levels, ICAPES data were used for the seven toxic
metals.
Metals Analyzed by ICAP
Calcium Iron
Magnesium Manganese
Sodium Molybdenum
Aluminum *Nickel
Boron *Lead
Barium Tin
*Berylliura Titanium
*Cadmium Vanadium
Cobalt Yttrium
^Chromium *Zinc
^Copper
Metals Analyzed by AA
*Antimony
*Arsenic
*Selenium
^Thallium
*Mercury
^Silver
*Toxic metals.
Analyses for the organic toxic pollutants were performed by
Arthur D. Little, ERGO, IT, S-Cubed, and West Coast Technical
Service. Analyses for the toxic metal pollutants were performed
by CENTEC, Radian, Versar, and NUS. Radian, ARO, and NUS per-
formed analyses for cyanide, conventional and nonconventional
pollutants.
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EPA did not expect to find any asbestos in nonferrous metals
forming wastewaters because this category only includes metals
that have already been refined from ores that might contain
asbestos. Therefore, analysis for asbestos fibers was not per-
formed.
Pesticide priority pollutants were also not expected to be sig-
nificant in the nonferrous metals forming industry. Samples from
one facility were analyzed for pesticide priority pollutants by
electron capture-gas chromatography by the method specified in 44
FR 69464, December 3, 1979. Pesticides were not detected in
these samples, so no other samples were analyzed for these
pollutants.
Analyses for the remaining organic priority pollutants (volatile
fraction, base/neutral, and acid compounds) were conducted using
an isotope dilution method which is a modification of the analyt-
ical techniques specified in 44 FR 69464, December 3, 1979. The
isotope dilution method has been recently developed to improve
the accuracy and reliability of the analysis. A copy of the
method is in the record of rulemaking for this proposed regula-
tion. However, no standard was used in the analysis of 2,3,7,8-
tetrachlorodibenzo-p-dioxin (TCDD, pollutant 129). Instead,
screening for this compound was performed by comparing analytical
results to EPA's gas chromatography/mass spectroscopy (GC/MS)
computer file.
Analysis for cyanide used methods specified in 40 CFR Part 136
and described in "Methods for Chemical Analysis for Water and
Wastes," EPA-600/4-79-020 (March 1979).
Past studies by EPA and others have identified many nontoxic
pollutant parameters useful in characterizing industrial waste-
waters and in evaluating treatment process removal efficiencies.
Some of these pollutants may also be selected as reliable indi-
cators of the presence of specific toxic pollutants. For these
reasons, a number of nontoxic pollutants were studied for the
nonferrous metals forming category. These pollutants may be
divided into two general groups as shown in Table V-3. Analyses
for these pollutants were performed by the methods specified in
40 CFR Part 136 and described in EPA-600/4-79-020.
The analytical quantification levels used in evaluation of the
sampling data reflect the accuracy of the analytical methods
employed. Below these concentrations, the identification of the
individual compounds is possible, but quantification is diffi-
cult. Pesticides and PCB ' s can be analytically quantified at
concentrations above 0.005 mg/1, and other organic toxic levels
above 0.010 mg/1. Levels associated with toxic metals are as
follows: 0.010 mg/1 for antimony; 0.010 mg/1 for arsenic; 1 x
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107 fibers/1 for asbestos; 0.005 mg/1 for beryllium; 0.020 mg/1
for cadmium; 0.020 mg/1 for chromium; 0.050 mg/1 for copper; 0.02
mg/1 for cyanide; 0.050 mg/1 for lead; 0.0002 mg/1 for mercury;
0.050 mg/1 for nickel; 0.010 mg/1 for selenium; 0.010 mg/1 for
silver; 0.010 mg/1 for thallium; and 0.020 mg/1 for zinc..
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, daily operator-specific,
and pollutant-specific factors. These factors can include
day-to-day differences in machine calibration and variation in
stock solutions, operators, and pollution sample matrices (i.e.,
presence of some chemicals will alter the detection of particular
pollutants).
Quality Control. Quality control measures used in performing all
analysesconducted for this program complied with the guidelines
given in "Handbook for Analytical Quality Control in Water and
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
samples 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.
Historical Data
A useful source of long-term or historical data available for
nonferrous metals forming plants are the Discharge Monitoring
Reports (DMR's) completed as a part of the National Pollutant
Discharge Elimination System (NPDES) and/or State Pollutant
Discharge Elimination System (SPDES). DMR's were obtained
through the EPA regional offices and state regulatory agencies
for the years 1981 through the most recent date available. The
DMR's present a summary of the analytical results from a series
of samples taken during a given month for the pollutants desig-
nated in the plant's permit. In general, minimum, maximum, and
average values, in mg/1 or Ibs/day, are presented for such pollu-
tants as total suspended solids, oil and grease, pH, chromium,
and zinc. The samples were collected from the plant outfall(s),
which represents the discharge(s) 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
serve as a basis for characterizing treated wastewater from non-
ferrous metals forming plants. However, there is no information
on concentration of pollutants in wastewater prior to treatment
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and too little information on the performance of the plant at the
time the samples were collected to use these data in evaluating
the performance of various levels of treatment. The data
reported in DMR's could be used to compare the treatment perfor-
mance of actual plants to the treatment effectiveness concentra-
tions presented in Section VII. However, it was not possible to
perform this comparison in the limited time available between
receipt of the DMR's and the Court Ordered deadline for proposal
of this regulation.
The DMR data for uranium forming plants included the toxic metals
cadmium, copper, and nickel. The data were used to select the
pollutants proposed for regulation in the uranium forming
subcategory.
WATER USE AND WASTEWATER CHARACTERISTICS
Water use, wastewater discharge, and analytical sampling data for
each subcategory are presented in the administrative record which
accompanies this rulemaking package. These data (listed by waste
stream) were collected from the dcp's and during field sampling.
They include source water concentrations and current recycle
practices.
Analytical sampling data are summarized in Tables V-4 through
V-14. These tables present the concentration range of regulated
pollutants detected in the waste streams sampled in each subcate-
gory. Selection of regulated pollutants is discussed in Section
VI.
As indicated in Table V-l, not every waste stream generated by
nonferrous metals forming operations was sampled during the
screen sampling program. However, in order to evaluate the
applicability of the various treatment technologies to non-
sampled waste streams, the physical and chemical characteristics
of these streams were extrapolated from similar sampled streams.
This extrapolation was also necessary to estimate the costs of
the various treatment technologies, as discussed in Section VIII.
Extrapolation of sampling data from sampled to non-sampled waste
streams was not used to select pollutants for regulation in this
category (see Section VI).
Waste streams generated by similar physical processes using
similar process chemicals will have very similar physical and
chemical characteristics. For example, water used to cool extru-
sions will have low concentrations of all pollutants. This is
demonstrated by the results of the chemical analyses of lead and
nickel extrusion press and solution heat treatment contact cool-
ing water (Table V-15). The major difference between these two
waste streams is that the concentration of lead is higher in the
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lead cooling water (0.13 mg/1 vs. not detected) and the concen-
tration of nickel is higher in the nickel cooling water (0.14
mg/1 vs. 0.007 mg/1). This pattern will be repeated whenever
water, without additives, is used to cool hot metal.
In contrast, spent rolling emulsions have high concentrations of
several pollutants. The results of chemical analyses of lead,
nickel, and precious metals rolling spent emulsions are presented
in Table V-16. All three waste streams have high concentrations
of oil and grease, total suspended and dissolved solids, and
several metals. The lead rolling spent emulsion has a high con-
centration of lead (29.0 mg/1), the nickel rolling spent emulsion
has high concentrations of nickel and chrome (8.95 mg/1 and 1.27
mg/1, respectively), and the precious metals rolling spent emul-
sion has high concentrations of copper, silver, and zinc (25.0
mg/1, 0.13 m^/1, and 6.00 mg/1, respectively). It is not sur-
prising to find chromium in nickel rolling spent emulsions and
copper and zinc in precious metals rolling spent emulsions
because chromium is a common alloy of nickel and copper and zinc
are common alloys of precious metals. Thus, the major difference
between the three waste streams is the presence of the metals
formed in the operation generating the waste stream.
From the discussion above, it follows that refractory metals,
zirconijum, and uranium extrusion press and solution heat treat-
ment contact cooling water will have chemical characteristics
similar to lead and nickel extrusion press and solution heat
treatment contact cooling water. The major difference between
the waste streams will be the concentration of the metal cooled.
Similarly, zinc and refractory metals rolling spent emulsions
will have chemical characteristics similar to lead, nickel and
precious metals rolling spent emulsions, except for the concen-
tration of the metal rolled. However, because zinc and lead are
rolled at lower temperatures than nickel and refractory metals,
zinc rolling spent emulsions may be more like lead rolling spent
emulsions and refractory metals rolling spent emulsions may be
more like nickel rolling spent emulsions.
Arguments analogous to those presented above were used to esti-
mate the physical and chemical characteristics of all non-sampled
waste streams. These estimations, and summaries of sampling
data, are presented below.
Lead/Tin/Bismuth Forming Subcategory
Rolling Spent Emulsions. As discussed in Section III, oil-in-
water emulsionsare used as coolants and lubricants. Rolling
emulsions are typically recycled using in-line filtration and
periodically batch discharged when spent.
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One sample of rolling spent emulsions was collected at one plant.
Elevated concentrations of lead (29 mg/1), zinc (1.4 mg/1), oil
and grease (270 mg/1), and TSS (480 mg/1) v/ere detected in the
sample.
Rolling Spent _Soajp__Solutions_. As discussed in Section III, soap
solutions can be used as lubricants and coolants in rolling. Of
the plants surveyed, only one plant reported the use of soap
solutions in rolling.
No samples of rolling spent soap solutions were collected during
the sceen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to
alkaline cleaning rinsewater in this subcategory. Spent soap
solutions contain the same process chemicals as alkaline cleaning
baths, at mass loadings (rag/kkg) similar to the concentrations
found in alkaline cleaning rinses. Therefore, the pollutants
present and the mass loadings of pollutants present, in rolling
spent soap solutions and alkaline cleaning rinses are expected to
be similar.
Drawing Spent Neat: OJ_l_s_. As discussed in Section III, oil-based
lubricants may be used in drawing operations to ensure uniform
drawing temperatures and avoid excessive wear on dies and man-
drels. Drawing oils are usually recycled until their lubricant
properties are exhausted and are then contract hauled.
Since none of the plants surveyed reported discharging the draw-
ing spent neat oils, no samples were collected.
Drawing Spent Emulsions. As discussed in Section 111, oil-in-
water emulsions can~Hb~e used as drawing lubricants. The drawing
emulsions are frequently recycled and batch discharged periodi-
cally after their lubricating properties are exhausted.
No samples of drawing spent emulsions were collected during the
screen sampling program. However, the Agency believes that this
stream will have wastewater characteristics similar to rolling
spent emulsions in this subcategory. These two waste streams are
generated from similar physical processes which use similar pro-
cess chemicals. Therefore, the pollutants present in each waste
stream and the mass loading (mg/kkg product) at which they are
present should be similar.
Drawing Spent jSoajj_ SoJ.irti.ons. As discussed in Section ill, soap
solutions can be used as drawing lubricants. The drawing soap
solutions are frequently recycled and batch discharged periodi-
cally after their lubricating properties are exhausted.
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No samples of drawing spent soap solutions were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to alka-
line cleaning rinsewater in this subcategory. Spent soap solu-
tions contain the same process chemicals as alkaline cleaning
baths, at concentrations similar to the concentrations found in
alkaline cleaning rinses. Therefore, the pollutants present and
the mass loadings at which they are present in drawing spent soap
solutions and alkaline cleaning rinses are expected to be
similar.
Extrusion Press and Solution Heat Treatment Contact Cooling
Water. As discussed in Section III, heat treatment of lead/tin/
bismuth products frequently involves the use of a water quench in
order to achieve desired metallic properties. Eleven plants
reported 16 extrusion press and solution heat treatment processes
that involve water quenching either by spraying water onto the
metal as it emerges from the die or press or by direct quenching
into a contact water bath.
One sample of extrusion press and solution heat treatment contact
cooling water was collected at one plant. Elevated concentra-
tions of chromium (4.6 mg/1) were detected in the sample.
Extrusion Press Hydraulic Fluid Leakage. As discussed in Section
III,due to thelargeforce applied by a hydraulic extrusion
press, hydraulic fluid leakage is unavoidable.
No samples of extrusion press hydraulic fluid leakage were col-
lected during the screen sampling program. However, the Agency
believes that this stream will have wastewater characteristics
similar to press hydraulic fluid leakage in the nickel/cobalt
subcategory. The pollutants present in these two waste streams
are attributable to the hydraulic fluid used, not the metal
formed. Therefore, the pollutants present and the concentration
(mg/1) at which they are present should be similar.
Continuous Strip Casting Contact Cooling Water. As discussed in
Section III, in continuous casting, no restrictions are placed on
the length of the casting and it is not necessary to interrupt
production to remove the cast product. Although the use of con-
tinuous casting techniques has been found to significantly reduce
or eliminate the use of contact cooling water and oil lubricants,
five plants reported the use of continuous strip contact cooling
water.
One sample of continuous strip casting contact cooling water was
collected at one plant. Elevated concentrations of lead (1.2
mg/1) and zinc (3.1 mg/1) were detected in the sample.
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Semi-Continuous Ingot Casting Contact Cooling Water. As dis-
cussed in Section III,semi-continuous ingot casting may require
the use of contact cooling water in order to achieve the desired
physical properties of the metal.
Two samples of semi-continuous ingot casting contact cooling
water were collected from one stream at one plant. Elevated con-
centrations of lead (1.10 mg/1) and TSS (80 mg/1) were detected
in the samples.
Shot Casting Contact Cooling Water. As discussed in Section III,
contact cooling water is required to cool the cast lead shot so
that it will not reconsolidate as well as to achieve the desired
metallic properties.
Three samples of shot casting contact cooling water were col-
lected from one stream at one plant. Elevated concentrations of
lead (52.2 mg/1), antimony (3.30 mg/1), tin (10.5 rag/1), oil and
grease (22 mg/1), and TSS (420 mg/1) were detected in the
samples.
Shot-Forming Wet Air Pollution Controj. Blowdown. As discussed in
Section III, shot-forming may require wet air pollution control
in order to meet air quality standards. Of the plants surveyed,
only one reported the use of wet air pollution control on a
shot-forming operation.
No samples of shot-forming wet air pollution control blowdown
were collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to shot casting contact cooling water in this
subcategory. The pollutants in each of these waste streams
derive from contact of the water with particles of metal, so the
pollutants present are expected to be similar. However, because
the air pollution control device is designed to capture small
particles (dust), the mass loading of total suspended solids is
expected to be higher in shot-forming wet air pollution control
blowdown than in shot casting contact cooling water.
Swaging Spent Emulsions. As discussed in Section III, oil-in-
water emulsions can be used as swaging lubricants. The swaging
emulsions are frequently recycled and batch discharged periodi-
cally after their lubricating properties are exhausted.
No samples of swaging spent emulsions were collected during the
screen sampling program. However, the Agency believes that this
stream will have wastewater characteristics similar to rolling
spent emulsions in this subcategory. These two waste streams are
generated from operations using similar process chemicals (oil-
in-water emulsions) for similar purposes (lubrication). There-
fore, the pollutants present in each waste stream and the mass
405
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loading (mg/kkg product) at which they are present should be
similar.
Alkaline Cleaning Spent Baths. As discussed in Section III,
alkaline cleaning iscommonly used to clean lead/tin/bismuth sur-
faces. Products can be cleaned with an alkaline solution either
by immersion or spray.
One sample of an alkaline cleaning spent bath was collected at
one plant. Elevated concentrations of lead (183 mg/1), antimony
(7.30 mg/1), oil and grease (600 mg/1), and TSS (560 mg/1) were
detected in the sample.
Alkaline Cleaning Rinsewater. As discussed in Section III, rins-
ing, usually with warm water, should follow the alkaline cleaning
process to prevent the solution from drying on the product.
Four samples of alkaline cleaning rinsewater were collected from
two streams at one plant. Elevated concentrations of lead (40.8
mg/1), antimony (1.10 mg/1), and TSS (260 mg/1) were detected in
the samples.
Degreasing Spent Solvents. As described in Section III, solvent
cleaners are used to remove lubricants (oils and greases) applied
to the surface of nonferrous metals during mechanical forming
operations. Basic solvent cleaning methods include straight
vapor degreasing, immersion-vapor degrasing, spray-vapor degreas-
ing, ultrasonic vapor degreasing, emulsified solvent degreasing,
and cold cleaning.
Solvents most commonly used for all types of vapor degreasing are
trichloroethylene, 1,1,1-trichloroethane, methylene chloride,
perchloroethylene, and various chlorofluorocarbons. Solvent
selection depends on the required process temperature (solvent
boiling point), product dimension, and metal characteristics.
Contaminated vapor degreasing solvents are frequently recovered
by distillation. The sludge residue generated is toxic and may
be flammable, requiring appropriate handling and disposal pro-
cedures .
Since none of the plants surveyed reported discharging the vapor
degreasing spent solvents, no samples were collected.
Miscellaneous Nondescript Wastewater Sources. Several low volume
sourcesof wastewater were reported on the dcp's and observed
during the site and sampling visits. These sources are mainte-
nance and cleanup, autoclave contact cooling water, final product
lubrication, and product degreasing rinsewater. Because they
generally represent low volume periodic discharges applicable to
most plants, the Agency is including an allowance for all of
406
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these streams under the miscellaneous nondescript wastewater
sources waste stream.
Operations Which Do Not Use Process Water. The Agency proposes a
discharge allowance of zero for operations which do not generate
process wastewater. The following operations generate no process
wastewater either because they are dry or because they use
noncontact cooling water only:
Continuous Wheel Casting
Continuous Sheet Casting
Stationary Casting
Shot Pressing
Forging
Stamping
Pointing
Punching
Shot Blasting
Slug Forming
Powder Metallurgy Operations (Pressing, Sintering, Sizing)
Powder Tumbling
Melting
Solder Cream Making
Annealing
Tumble Cleaning
Slitting
Sawing
Coiling, Spooling
Trimming
Nickel/Cobalt Forming Subcategory
Rolling Spent Neat Oils. As described in Section III, the
rolling of nickel/cobalt products typically requires the use of
mineral oil lubricants. The oils are usually recycled with
in-line filtration and periodically disposed of by sale to an oil
reclaimer or by incineration. Because discharge of this stream
is not practiced, limited flow data were available for analysis.
Since none of the plants surveyed reported discharging the roll-
ing spent neat oils, no samples of this waste stream were
collected.
Rolling Spent Emulsions. As discussed in Section III, oil-in-
water emulsions are used in rolling operations as coolants and
lubricants. Rolling emulsions are typically recycled using
in-line filtration with periodic batch discharge of the spent
emulsion.
407
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Twelve samples of rolling spent emulsions were collected from six
streams at two plants. Elevated concentrations of nickel (34.2
mg/1), zinc (6.70 mg/1), oil and grease (7,600 mg/1), and TSS
(6,800 mg/1) were detected in the samples.
Rolling Contact Lubricant-Coolant Watery. As discussed in Section
III, it is necessary to use a lubricants-coolant during rolling to
prevent excessive wear on the rolls, to prevent adhesion of metal
to the rolls, and to maintain a suitable and uniform rolling tem-
perature. Water is one type of lubricant-coolant which may be
used.
One sample of rolling contact lubricant-coolant water was col-
lected at one plant. Elevated concentrations of copper (1.3
mg/1), fluoride (2,000 mg/1), oil and grease (22 mg/1), and TSS
(63 mg/1) were detected in the sample.
Rolling Solution Heat Treatment Contact Cooling Water. As dis-
cussed in Section III, solution heat treatment can be used after
most forming operations in order to improve mechanical properties
by maximizing the concentration of hardening contaminants in the
solid metal solution. Solution heat treatment typically involves
significant quantities of contact cooling water.
No samples of rolling solution heat treatment contact cooling
water were collected during the screen sampling program. How-
ever', the Agency believes that this stream will nave wastewater
characteristics similar to extrusion press and solution heat
treatment contact cooling water in this subcategory. These two
waste streams are generated from operations using water for an
identical purpose: to cool hot metal. In addition, no process
chemicals are added to either type of cooling water. Therefore,
both the pollutants present and the mass loadings of pollutants
present in these two waste streams are expected to be similar.
Tube Reducing Spent Lubricants. As discussed in Section III,
tube reducing, much like rolling, may require a lubricating com-
pound in order to prevent excessive wear of the tube reducing
rolls, prevent adhesion of metal to the rolls, and to maintain a
suitable and uniform tube reducing temperature.
One sample of tube reducing spent lubricants was collected from
one stream at one plant. Elevated concentrations of nickel (58.0
mg/1), copper (43.5 mg/1), lead (47.6 mg/1), zinc (63.1 mg/1),
and oil and grease (200,000 mg/1) were detected in the sample.
In addition, the sample had elevated concentrations of the toxic
organics 1,1,1-trichloroethane (33 mg/1) and N-nitrosodiphenyl-
amine (28.2 mg/1).
Drawing Spent Neat Oils. As discussed^in Section III, oil-based
lubricants may be required in draws which have a high reduction
408
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in diameter. Drawing oils are usually recycled, with in-line
filtration, until their lubricating properties are exhausted.
Since none of the plants surveyed reported discharging the draw-
ing spent neat oils, no samples were collected.
Drawing Spent Emulsions. As discussed in Section III, oil-in-
water emulsions are often used as coolants and lubricants in
drawing. The drawing emulsions are frequently recycled and batch
discharged periodically after their lubricating properties are
exhausted.
No samples of drawing spent emulsions were collected during the
screen sampling program. However, the Agency believes that this
stream will have wastewater characteristics similar to rolling
spent emulsions in this subcategory. These two waste streams are
generated from operations using similar process chemicals (oil-
in-water emulsions) for similar purposes (lubrication). There-
fore, the pollutants present and the mass loadings of pollutants
present in these two waste streams are expected to be similar.
Extrusion Spent Lubricants. As discussed in Section III, the
extrusion process requires the use of a lubricant to prevent
adhesion of the metal to the die and ingot container walls.
Since none of the plants surveyed reported wastewater discharge
values for extrusion spent lubricants, no samples of this waste
stream were collected.
Extrusion Press and Solution Heat Treatment Contact Cooling
Water.Asdiscussed in Section III,heat treatmentisfrequently
used after extrusion to attain the desired mechanical properties
in the extruded metal. Contact cooling of the extrusion, some-
times called press heat treatment, can be accomplished with a
water spray near the die or by immersion in a water tank adjacent
to the runout table.
One sample of extrusion press heat treatment contact cooling
water was collected at one plant. Elevated concentrations of
chromium (0.130 mg/1) were detected in the sample.
Forging, Extrusion, and Isostatic Press Hydraulic Fluid Leakage.
As discussed in Section III, due to the large force applied by a
hydraulic press, hydraulic fluid leakage is unavoidable.
Three samples of extrusion press hydraulic fluid leakage were
collected at one plant and one sample of forging press hydraulic
fluid leakage was collected at another plant. Elevated concen-
trations of nickel (1.30 mg/1), oil and grease (420 mg/1), and
TSS (500 mg/1) were detected in the samples.
409
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Forging Equipment Cleaning Wastewater. Forging equipment may be
periodically cleaned in order to prevent the excessive build-up
of oil and grease on the forging die.
No samples of forging equipment cleaning wastewater were col-
lected during the screen sampling program. However, the Agency
believes that this stream will have wastewater characteristics
similar to forging die contact cooling water in this subcategory.
These two waste streams are generated from similar physical
processes (flushing a forging die with water), so the pollutants
present are expected to be similar. However, the water is used
for different purposes, in one case to cool a hot die, in the
other, to remove built-up contaminants. Therefore, the mass
loadings of oil and grease are expected to be higher in forging
equipment cleaning wastewater than in forging die contact cooling
water.
Forging Die Contact Cooling Water. As discussed in Section III,
forging dies may require cooling to maintain the proper die tem-
perature between forgings, or to cool the dies prior to removal
from the forge hammer.
One sample of forging die contact cooling water was collected at
one plant. Elevated concentrations of nickel (16 mg/1), copper
(3.4 mg/1) and TSS (1,800 mg/1) were detected in the sample.
Forging and Swaging Spent Neat Oils. As described in Section
IIl7 an oil medium can be usedfor proper lubrication of forging
and swaging dies. Of the plants surveyed reporting the use of
forging and swaging neat oils, all recycle the oils until their
lubricating properties are exhausted, at which time the oils are
contract hauled.
Since none of the plants surveyed reported discharging the forg-
ing and swaging spent neat oils, no samples of this waste stream
were collected.
Stationary and Direct Chill Casting Contact Cooling Water. As
discussed in Section III, contact cooling water is a necessary
part of direct chill casting and is sometimes used in stationary
casting. The cooling water may be contaminated by lubricants
applied to the mold before and during the casting process and by
the cast metal itself.
No samples of stationary and direct chill casting contact cooling
water were collected during the screen sampling program. How-
ever, the Agency believes that this stream will have wastewater
characteristics similar to rolling contact lubricant-coolant
water in this subcategory. These two waste streams are generated
from operations using water for similar purposes (to cool hot
410
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metal). In addition, no process chemicals are added to either
type of cooling water. Therefore, both the pollutants present
and the mass loadings of pollutants present in the two streams
are expected to be similar.
Vacuum Melting Steam Condensate. As discussed in Section III,
nickel/cobalt may be melted by an operation known as vacuum melt-
ing. The high pressure steam used to create the vacuum condenses
to an extent as it produces the vacuum. Although this water does
not come in contact with the metal product, it may potentially be
contaminated with metal fines or components of lubricant com-
pounds volatilized in the furnace if scrap is being melted.
One sample of vacuum melting steam condensate was collected at
one plant. No pollutants were detected in the sample at elevated
concentrations.
Metal Powder Production Atomization Wastewater. As discussed in
Section III,metal powder iscommonly produced through wet atomi-
zation of a molten metal. Of the plants surveyed, three reported
the use of water in atomization of molten nickel.
One sample of metal powder production atomization wastewater was
collected at one plant. Elevated concentrations of chromium (1.0
mg/1), cobalt (5.2 mg/1), TSS (63 mg/1), and oil and grease (22
mg/1; were detected in the sample.
Annealing Solution Heat Treatment Contact Cooling Water. As
discussed in Section III, solution heat treatment is implemented
after annealing operations to improve mechanical properties by
maximizing the concentration of hardening contaminants in the
solid metal solution. Solution heat treatment typically involves
significant quantities of contact cooling water.
Two samples of solution heat treatment contact cooling water were
collected from two streams at two plants. Elevated concentra-
tions of nickel (6.80 mg/1), copper (2.92 mg/1), oil and grease
(40 mg/1), and TSS (78 mg/1) were detected in the samples.
Vet Air Pollution Control Slowdown. As discussed in Section III,
wet air pollution control devices^are required to control air
pollution from some operations. Scrubbers are frequently neces.-
sary over pickling operations to control fumes and over shot
blasting operations to control particulates.
Two samples of wet air pollution control blowdown were collected.
Slowdown from a scrubber on a pickling operation was sampled at
one plant and on a shot blasting operation at another plant.
Elevated concentrations of nickel (20.0 mg/1), copper (2.85
mg/1), chromium (1.75 mg/1), and TSS (130 mg/1) were detected in
the samples.
411
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Surface Treatment Spent Baths. As discussed in Section III, a
number of chemical surface treatments may be applied after the
forming of nickel/cobalt products. Although spent surface treat-
ment baths are often discharged, two out of 22 plants reporting
surface treatment baths have the spent baths contract hauled.
Samples of five spent surface treatment baths were collected at
two plants. Very high concentrations of nickel (193,000 mg/1),
copper (4,800 mg/1), cobalt (4,000 mg/1), chromium (3,600 mg/1),
fluoride (94,000 mg/1), and TSS (5,800 mg/1) were detected in the
samples.
Sjurface Treatment Rinsewater. As discussed in Section III, rins-
ing follows the surface treatment process to prevent the surface
treatment solution from affecting the surface of the metal beyond
the desired amount.
Twenty-three samples of surface treatment rinsewater were col-
lected from eight streams at three plants. Elevated concentra-
tions of nickel (364 mg/1), copper (87.4 mg/1), chromium (18.8
mg/1), cobalt (4.0 mg/1), zinc (2.36 mg/1), oil and grease (130
mg/1), and TSS (760 mg/1) were detected in the samples.
Alkaline Cleaning Spent Baths. As discussed in Section III,
alkaline cleaners are formulations of alkaline salts, water, and
surfactants. Spent solutions are discharged from alkaline clean-
ing processes.
Three samples of alkaline cleaning spent baths were collected
from three streams at two plants. Elevated concentrations of
nickel (122 mg/1), copper (39.2 mg/1), zinc (3.9 mg/1), chromium
(3.59 mg/1), oil and grease (49 mg/1), and TSS (4,000 mg/1) were
detected in the samples.
Alkaline Cleaning Rinsewater. As discussed in Section III, metal
parts are usually rinsed following alkaline cleaning to remove
the cleaning solution and any solubilized contaminants.
Four samples of alkaline cleaning rinsewater were collected from
three streams at two plants. Elevated concentrations of nickel
(5.58 mg/1), mg/1), oil and grease (26 mg/1), and TSS (190 mg/1)
were detected in the samples.
Molten Salt Spent Baths. As discussed in Section III, molten
salt baths are used to descale nickel and cobalt alloys. Formed
parts to be descaled are immersed in the bath for up to 15
minutes, removed, and water-quenched.
When removed from the heated bath container, the molten salt bath
solution solidifies and is no longer a liquid waste stream. The
solidified spent salt bath is usually discarded as a hazardous
412
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waste because it contains high concentrations of hexavalent chro-
mium. Therefore, no samples of molten salt baths were collected.
Molten Salt Rinsewater. As discussed in Section III, when molten
salt baths are used to descale nickel and cobalt alloys, they are
generally followed by a water quench/rinse step.
Seven samples of molten salt rinsewater were collected from three
streams at three plants. Elevated concentrations of nickel (14
mg/1), copper (8.05 mg/1), cobalt (2.8 mg/1), chromium (1,100.
mg/1), and TSS (4,200 mg/1) were detected in the samples.
Ammonia Rinse Wastewater. As discussed in Section III, an
ammonia rinse may be used after acid pickling of nickel/cobalt
products to neutralize the acid prior to further rinsing. The
ammonia rinse is periodically batch discharged when spent.
One sample of ammonia rinse wastewater was collected at one
plant. Elevated concentrations of nickel (456 mg/1), copper
(54.0 mg/1). chromium (108 mg/1), zinc (32.0 mg/1), and TSS
(9,000 mg/1) were detected in the sample.
Sawing/Grinding Spent Lubricants. As discussed in Section III,
sawing/grinding operations generally require a lubricant in order
to minimize friction and act as a coolant.
Ten samples of sawing/grinding spent lubricants were collected
from 10 streams at two plants. Elevated concentrations of nickel
(116 mg/1), copper (16.5 mg/1), cobalt (3.3 mg/1), chromium (24.0
mg/1), oil and grease (16,000 mg/1), and TSS (2,440 mg/1) were
detected in the samples.
Steam Cleaning Condensate. As discussed in Section III, steam
cleaning may be used to remove oil and grease from the surface of
metal. Steam is condensed as it hits the surface of the rela-
tively cooler metal and is then discharged.
No samples of steam cleaning condensate were collected during the
screen sampling program. However, the Agency believes that this
stream will have wastewater characteristics similar to rolling
contact lubricant-coolant water in this subcategory. These two
waste streams are generated in processes in which water, without
any added process chemicals, contacts metal. In the case of
contact lubricant-coolant water, the metal is hot and the water
(relatively) cool. In the case of steam cleaning condensate,
the water/steam is hot and the metal (relatively) cool. However,
the pollutants present and the mass loadings of pollutants
present in the two streams are expected to be similar.
413
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Hydrostatic Tube Testing Wastewajber. As discussed in Section
III, hydrostatic testing operations are used to check nonferrous
metals parts for surface defects or subsurface imperfections.
Hydrostatic testing operations are sources of wastewater because
the spent water bath or test media must be periodically discarded
due to the transfer into the testing media of oil and grease,
solids, and suspended and dissolved metals from each product
tested.
No samples of hydrostatic tube testing wastewater were collected
during the screen sampling program. However, the Agency believes
that this stream will have wastewater characteristics similar to
rolling contact lubricant-coolant water in this subcategory.
These two waste streams are generated in processes in which
water, without any added process chemicals, contacts metal.
Therefore, the pollutants present in each waste stream and the
mass loading (mg/kkg) at which they are present should be
similar.
Degreasing Spent Solvents. As described in Section III, solvent
cleaners are used to remove lubricants (oils and greases) applied
to the surface of nonferrous metals during mechanical forming
operations. Basic solvent cleaning methods include straight
vapor degreasing, immersion-vapor degreasing, spray-vapor
degreasing, ultrasonic vapor degreasing, emulsified solvent
degreasing, and cold cleaning.
Solvents most commonly used for all types of vapor degreasing are
trichloroethylene, 1,1,1-trichloroethane, methylene chloride,
perchloroethylene, and various chlorofluorocarbons. Solvent
selection depends on the required process temperature (solvent
boiling point), product dimension, and metal characteristics.
Contaminated vapor degreasing solvents are frequently recovered
by distillation. The sludge residue generated is toxic and may
be flammable, requiring appropriate handling and disposal pro-
cedures .
Since none of the plants surveyed reported discharging the vapor
degreasing spent solvents, no samples were collected.
Miscellaneous Nondescript Wastewater Sources. Several low volume
sources oTT wastewater" were report eT~on~ the Hep and observed dur-
ing the site and sampling visits. These sources are maintenance
and cleanup, final product Uibrication, and product degreasing
rinsewater. Because they generally represent low volume periodic
discharges applicable to most plants, the Agency is including an
allowance for all of these streams under the miscellaneous
nondescript wastewater soitrc.es wast*3 stream.
Operations Which Do Not_l)eo Process 'water. Ihe Agency proposes a
dischargr allowance or zn-.. lor ope-'af Ions vuvLch do not generate
4.U
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process wastewater. The following operations generate no process
wastewater, either because they are dry or because they use
noncontact cooling water only:
Powder Metallurgy Operations (Compacting, Sintering, Sizing)
Powder Blending
Powder Ball Milling
Powder Attrition
Powder Extrusion
Hot Isostatic Pressing
Grit, Sand, Shot Blasting
Welding
Plasma Torch Cutting
Gas Cleaning
Coil Buildup, Coiling
Straightening
Electroflux Remelting
Zinc Forming Subcategory
Rolling Spent Neat Oils. As described in Section III, mineral
oil or kerosene-based lubricants can be used in the rolling of
zinc products. The oils are usually recycled with in-line fil-
tration and periodically disposed of by sale to an oil reclaimer
or by incineration.
Since none of the plants surveyed reported discharging the roll-
ing spent neat oils, no samples were collected.
Rolling Spent Emulsions. As discussed in Section III, oil-in-
water emulsions are used in rolling operations as coolants and
lubricants. Rolling emulsions are typically recycled using
in-line filtration treatment, with periodic batch discharge of
the recycled emulsion.
No samples of rolling spent emulsions were collected during the
screen sampling program. However, the Agency believes that this
stream will have wastewater characteristics similar to rolling
spent emulsions in the lead/tin/bismuth subcategory. These two
waste streams are generated by identical physical processes which
use similar process chemicals. The only difference should be the
identity of metals present. The mass loading (mg/kkg) of zinc in
zinc rolling spent emulsions should be similar to the mass load-
ing of lead in lead rolling spent emulsions, and vice versa. The
other pollutants present in each waste stream and the mass load-
ing at which they are present should be similar.
Rolling Contact Lubricant-Coolant Water. As discussed in Section
III,it is necessary to use a lubricant-coolant during rolling to
prevent excessive wear on the rolls, to prevent adhesion of metal
415
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to the rolls, and to maintain a suitable and uniform rolling tem-
perature. Water is one type of lubricant-coolant which may be
used.
No samples of rolling contact lubricant-coolant water were col-
lected during the screen sampling program. However, the Agency
believes that this stream will have wastewater characteristics
similar to casting contact cooling water in the lead/tin/bismuth
subcategory. These two waste streams are generated by using
water, without additives, to cool hot metal. The only difference
between the wastewater characteristics of the two streams should
be the metals present. The mass loading (mg/kkg) of zinc in zinc
rolling contact lubricant-coolant water should be similar to the
mass loading of lead in lead casting contact cooling water, and
vice versa. The other pollutants present in each waste stream
and the mass loading at which they are present should be
similar.
Drawing Spent Emulsions. As discussed in Section III, oil-in-
water emulsions are used for many drawing applications in order
to ensure uniform drawing temperatures and avoid excessive wear
on the dies and mandrels used. The drawing emulsions are fre-
quently recycled and batch discharged periodically after their
lubricating properties are exhausted.
No samples of drawing spent emulsions were collected during the
screen sampling program. However, the Agency believes that this
stream will have wastewater characteristics similar to rolling
spent emulsions in the lead/tin/bismuth subcategory. These waste
streams are generated from operations using similar process chem-
icals (oil-in-water emulsions) for similar purposes (lubrica-
tion). The only difference should be the metals present. The
mass loading (mg/kkg) of zinc in zinc drawing spent emulsions
should be similar to the mass loading of lead in lead rolling
spent emulsions, and vice versa. The other pollutants present in
each waste stream and the mass loading at which they are present
should be similar.
Direct Chill Casting Contact Cooling Water. As discxissed in Sec-
tion III, contact cooling water is a necessary part of direct
chill casting. The cooling water may be contaminated by lubri-
cants applied to the mold before and during the casting process.
The cooling water may be recycled.
No samples of direct chill casting contact cooling water were
collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to semicontinuous ingot casting contact cooling
water in the lead/tin/bismuth subcategory. These two waste
streams are generated by using water, without additives, to cool
416
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cast metal. Since lubricants may be applied to the casting molds
in both processes, both streams may be contaminated by these
lubricants. The only difference between the waste streams should
be the metals present. The mass loading (mg/kkg) of zinc in zinc
direct chill casting contact cooling water should be similar to
the mass loading of lead in lead semicontinuous ingot casting
contact cooling water, and vice versa. The other pollutants
present and the mass loading at which they are present should be
similar.
Stationary Casting Contact Cooling Water. As discussed in Sec-
tion III, lubricants and cooling water are usually not required
in stationary casting. Since molten metal is poured into the
molds, if contact cooling water is used, it is frequently lost
due to evaporation.
Since none of the plants surveyed reported discharging the
stationary casting contact cooling water, no samples were
collected.
Solution Heat Treatment Contact Cooling Water. As discussed in
Section III, solution heat treatment is implemented after most
forming operations to improve mechanical properties by maximizing
the concentration of hardening contaminants in solid solution.
Solution heat treatment typically involves significant quantities
of contact cooling water.
No samples of solution heat treatment contact cooling water were
collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to continuous sheet casting contact cooling water
in the lead/tin/bismuth subcategory. These two waste streams
derive from the use of water, without additives, to cool hot
metal. The only difference should be the metals present. The
mass loading (mg/kkg) of zinc in zinc solution heat treatment
contact cooling water should be similar to the mass loading of
lead in lead continuous sheet casting contact cooling water, and
vice versa. The other pollutants present in each waste stream
and the mass loading at which they are present should be
similar.
Surface Treatment Rinsewater. As discussed in Section III, rins-
ing follows the surtace treatment process to prevent the solution
from affecting the surface of the metal beyond the desired
amount.
One sample of surface treatment rinsewater was collected at one
plant. Elevated concentrations of zinc (42.3 mg/1), chromium
(0.160 mg/1), nickel (8.10 mg/1), and TSS (20 mg/1) were detected
in the sample.
417
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Alkaline Cleaning Spent Baths. As discussed in Section III,
alkaline cleaners are formulations of alkaline salts, water, and
surfactants. Spent solutions are discharged from alkaline clean-
ing processes after their properties are exhausted.
No samples of alkaline cleaning spent baths were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to alka-
line cleaning rinsewater in this subcategory. As a zinc piece is
removed from an alkaline cleaning bath, it carries a small volume
of the bath with it. The rinsewater used to remove the carried-
over bath solution from the formed piece will contain the same
pollutants as the bath, only diluted. Therefore, the pollutants
present in zinc alkaline cleaning baths are expected to be iden-
tical to the pollutants present in zinc alkaline cleaning rinse-
water, except that the mass loadings of oil and grease and dis-
solved metals are expected to be higher in the spent baths than
in the rinsewater while the mass loading of total suspended
solids is expected to be much higher in the baths than in the
rinsewater.
Alkaline Cleaning Rinsewater. As discussed in Section III, fol-
lowing alkaline treating, metal parts are rinsed. Rinses are
discharged from alkaline cleaning processes.
One sample of alkaline cleaning rinsewater was collected at one
plant. Elevated concentrations of zinc (1.12 mg/1), cyanide (1.3
mg/1), oil and grease (23 mg/1), and TSS (90 mg/1) were detected
in the sample.
Sawing/Grinding Spent Lubricants. As discussed in Section III,
sawing/grinding operations generally require a lubricant: in order
to minimize friction and act as a coolant.
No samples of sawing/grinding spent lubricants were collected
during the screen sampling program. However, the Agency believes
that this stream will have wastewater characteristics similar to
sawing/grinding spent lubricants in the nickel/cobalt subcate-
gory. These two waste streams are generated by identical physi-
cal processes which use similar process chemicals. The only dif-
ference should be the metals present. The mass loading (mg/kkg)
of zinc in zinc sawing/grinding spent lubricants should be simi-
lar to the mass loading of nickel in nickel sawing/grinding spent
lubricants, and vice versa. The mass loading of chromium in zinc
sawing/grinding spent lubricants should be insignificant, since
chromium is often alloyed with nickel but not with zinc,, The
other pollutants present in each waste stream and the mass
loading at which they are present should be similar.
418
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Degrees ing Spent Solvents. As described in Section III, solvent
cleaners are used to remove lubricants (oils and greases) applied
to the surface of nonferrous metals during mechanical forming
operations. Basic solvent cleaning methods include straight
vapor degreasing, immersion-vapor degreasing, spray-vapor
degreasing, ultrasonic vapor degreasing, emulsified solvent
degreasing, and cold cleaning.
Solvents most commonly used for all types of vapor degreasing are
trichloroethylene, 1,1,1-trichloroethane, methylene chloride,
perchloroethylene, and various chlorofluorocarbons. Solvent
selection depends on the required process temperature (solvent
boiling point), product dimension, and metal characteristics.
Contaminated vapor degreasing solvents are frequently recovered
by distillation. The sludge residue generated is toxic and may
be flammable, requiring appropriate handling and disposal pro-
cedures .
Since none of the plants surveyed reported discharging the vapor
degreasing spent solvents, no samples were collected.
Operations Which Do Not Use Process Water. The Agency proposes a
discharge allowance of zero for operations which do not generate
process wastewater. The following operations generate no process
wastewater, either because they are dry operations or because
they use only noncontact cooling water:
Continuous Casting
Melting
Slitting
Stamping
Sawing
Homogenizing
Printing
Coating
Drying
Metal Powder Production
Beryllium Forming Subcategory
Area Cleaning Wastewater. Due to the toxicity of beryllium, it
is necessary to keepforming areas reasonably clean. After the
operations of a shift, areas need to be hosed down.
No samples of area cleaning wastewater were collected during the
screen sampling program. However, the Agency believes that this
stream will have wastewater characteristics similar to billet
washing wastewater in this subcategory. These two waste streams
are generated in washing/cleaning operations. Therefore, the
pollutants present in beryllium area cleaning wastewater are
419
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expected to be identical to the pollutants present in beryllium
billet washing wastewater, except that mass loadings of oil and
grease and total suspended solids are expected to be higher in
the area cleaning wastewater.
Billet Washing Wastewater. Beryllium billets are washed after
vacuum casting and sintering to remove an oxide layer on the
billet formed at the elevated casting and sintering temperatures.
Billets are washed using a high pressure spray nozzle to blast
off the oxide layer. In the plant surveyed, the wastewater is
not recirculated.
Two samples of billet washing wastewater were collected from two
streams at one plant. Elevated concentrations of beryllium (82
mg/1), copper (0.75 mg/1), and TSS (160 mg/1) were detected in
the samples.
Surface Treatment Spent Baths. As discussed in Section III, a
number of chemical treatments may be applied after the forming of
nonferrous metals products. Beryllium products are commonly
etched with a nitric acid-hydrofluoric acid solution. The acid
bath is used until its etching properties have been diminished
and fresh chemicals are needed.
One sample of a surface treatment spent bath was collected at one
plant. Elevated concentrations of beryllium (15,000 mg/1),
chromium, (3.0 mg/1), zinc (2.0 mg/1), nickel (2.4 mg/1), fluoride
(79,000 mg/1), and TSS (240 mg/1; were detected in the sample.
Surface Treatment Rinsewater. As discussed in Section III, after
a surface treatment bath,tHe nonferrous metal product must be
rinsed in order to stop the surface reaction from proceeding
beyond the desired amount. An overflow rinse tank is used after
the beryllium etching bath in the plant surveyed.
Two samples of surface treatment rinsewater were collected from
one stream at one plant. Elevated concentrations of beryllium
(35 mg/1), copper (6.1 mg/1), and TSS (18 mg/1) were detected in
the samples.
Sawing/Grinding Spent Lubricants. As discussed in Section III,
sawing/grinding operations generally require a lubricant in order
to minimize friction and act as a coolant.
One sample of sawing/grinding spent lubricants was collected at
one plant. Elevated concentrations of beryllium (17 mg/1), zinc
(0.86 mg/1), copper (1.5 mg/1), cyanide (1.1 mg/1), oil and
grease (21,000 mg/1), and TSS (19 mg/1) were detected in the
sample.
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Inspection/Testing Wastewater. As discussed in Section III,
product testing operations are used to check nonferrous metals
parts for surface defects, subsurface imperfections, and product
density. Product testing operations are usually sources of
wastewater because the spent water bath or test media must be
periodically discarded due to the transfer into the testing media
of oil and grease, solids, and suspended and dissolved metals
from each product tested. Toxic organics may also be present,
originating in the lubricants used in preceding forming opera-
tions. Beryllium products are washed before undergoing density
testing, therefore, no pollutants are expected in this waste
stream. The testing water is used indefinitely at the plant
surveyed.
One sample of inspection/testing wastewater was collected at one
plant. No pollutants were detected at elevated concentrations in
the sample.
Degreasing Spent Solvents. As described in Section III, solvent
•cleaners are used to remove lubricants (oils and greases) applied
to the surface of nonferrous metals during mechanical forming
operations. Basic solvent cleaning methods include straight
vapor degreasing, immersion-vapor degreasing, spray-vapor
degreasing, ultrasonic vapor degreasing, emulsified solvent
degreasing, and cold cleaning.
Solvents most commonly used for all types of vapor degreasing are
trichloroethylene, 1,1,1-trichloroethane, methylene chloride,
perchloroethylene, and various chlorofluorocarbons. Solvent
selection depends on the required process temperature (solvent
boiling point), product dimension, and metal characteristics.
Contaminated vapor degreasing solvents are frequently recovered
by distillation. The sludge residue generated is toxic and may
be flammable, requiring appropriate handling and disposal pro-
cedures.
Since none of the plants surveyed reported discharging the vapor
degreasing spent solvents, no samples were collected.
Operations Which Do Not Use Process Water. The Agency proposes a
discharge allowance of zero for operations which do not generate
process wastewater. The following operations generate no process
wastewater, either because they are dry or because they use only
noncontact cooling water:
Billet Chipping
Powder Metallurgy Operations (Pressing, Sintering)
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Precious Metals Forming Subcategory
Rolling Spent Emulsions. As discussed in Section III, oil-in-
water emulsions are used in rolling operations as coolants and
lubricants. Rolling emulsions are typically recycled using
in-line filtration with periodic batch discharge of the recycled
emulsion as it loses its lubricating properties.
One sample of rolling spent emulsions was collected at one plant.
Elevated concentrations of silver (0.130 mg/1), copper (25.0
mg/1), lead (1.00 mg/1), nickel (1.00 mg/1), oil and grease
(1,500 mg/1), and TSS (500 mg/1) were detected in the sample.
Rolling Solution Heat Treatment Contact Cooling Water. As dis-
cussed in Section III,solution heat treatment can be used after
most forming operations in order to improve mechanical properties
by maximizing the concentration of hardening contaminants in
solid solution. Solution heat treatment typically involves
significant quantities of contact cooling water.
No samples of rolling solution heat treatment contact cooling
water were collected during the screen sampling program. How-
ever, the Agency believes that this stream will have wastewater
characteristics similar to semi-continuous and continuous casting
contact cooling water in this subcategory. These two waste
streams are generated by the use of water, without additives, to
cool hot metal. Therefore, the pollutants present in each waste
stream and the mass loading at which they are present, should be
similar.
Drawing Spent Neat Oils. As discussed in Section III, oil-based
lubricantsmay be required in draws which have a high reduction
in diameter. Drawing oils are usually recycled until their
lubricating properties are exhausted.
Since none of the plants surveyed reported discharging the draw-
ing spent neat oils, no samples were collected.
Drawing Spent Emulsions. As discussed in Section III, oil-in-
water emulsions may be used as coolants and lubricants in draw-
ing. The drawing emulsions are frequently recycled and batch
discharged periodically after their lubricating properties are
exhausted.
One sample of drawing spent emulsions was collected at one plant.
Elevated concentrations of copper (46.4 mg/1), zinc (5.18 mg/1),
lead (1.05 mg/1), and oil and grease (33,000 mg/1) were detected
in the sample.
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Drawing Spent Soap Solutions. As discussed in Section III, soap
solutions can be used as drawing lubricants. The drawing soap
solutions may be recycled and batch discharged periodically after
their lubricating properties are exhausted.
No samples of drawing spent soap solutions were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to roll-
ing spent emulsions in this subcategory. These two waste streams
are generated from operations using similar process chemicals for
similar purposes (lubrication). Therefore, the pollutants pres-
ent and the mass loading at which they are present should be
similar.
Extrusion Solution Heat Treatment Contact Cooling Water. As dis-
cussed in Section III, solution heat treatment can be used after
most forming operations in order to improve mechanical properties
by maximizing the concentration of hardening contaminants in
solid solution. Solution heat treatment typically involves
significant quantities of contact cooling water.
No samples of extrusion solution heat treatment contact cooling
water were collected during the screen sampling program. How-
ever, the Agency believes that this stream will have wastewater
characteristics similar to semi-continuous and continuous contact
cooling water in this subcategory. These two waste streams are
generated by using water, without additives, to cool hot metal.
Therefore, the pollutants present in each waste stream and the
mass loading at which they are present should be similar.
Semi-Continuous and Continuous Casting Contact Cooling Water. As
discussed in Section III,a number of different continuouscast-
ing processes are currently being used in industry. The use of
continuous casting techniques has been found to significantly
reduce or eliminate the use of contact cooling water and oil
lubricants.
One sample of semi-continuous and continuous casting contact
cooling water was collected at one plant. Elevated concentra-
tions of cyanide (0.50 mg/1) and TSS (43 mg/1) were detected in
the sample.
Stationary Casting Contact Cooling Water. As discussed in Sec-
tion III, stationary casting of metal ingots is practiced at many
nonferrous metals forming plants. Lubricants and cooling water
are usually not required, however, two of the plants surveyed re-
ported the use and discharge of stationary casting contact cool-
ing water.
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No samples of stationary casting contact cooling water were col-
lected during the screen sampling program. However, the Agency
believes that this stream will have wastewater characteristics
similar to semi-continuous and continuous casting contact cooling
water in this subcategory. These two waste streams are; generated
by using water, without additives, to cool hot metal. Therefore,
the pollutants present in each waste stream and the mass loading
at which they are present should be similar.
Direct Chill Casting Contact Cooling Water. As discussed in Sec-
tion III, contact cooling water is a necessary part of direct
chill casting. The cooling water may be contaminated by lubri-
cants applied to the mold before and during the casting process.
No samples of direct chill casting contact cooling water were
collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar^to semi-continuous and continuous casting contact
cooling water in this subcategory. These two waste streams are
generated by using water, without additives, to cool hot metal.
Therefore, the pollutants present in each waste stream and the
mass loading at which they are present should be similar.
Shot Casting Contact Cooling Water. As discussed in Section III,
during shot casting,a tank of contact cooling water, either
stagnant or circulating, is necessary for quick quenching of cast
shot.
Two samples of shot casting contact cooling water were collected
from one stream at one plant. Elevated concentrations of cadmium
(9.88 mg/1), copper (0.600 mg/1), zinc (5.66 mg/1), and oil and
grease (54 mg/1) were detected in the samples.
Casting Wet Air Pollution Control Blowdown. As discussed in Sec-
tion III, casting may require wet air pollution control in order
to meet air quality standards. Of the plants surveyed, two
reported the use of wet air pollution control on a casting
operation.
No samples of casting wet air pollution control blowdown were
collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to shot casting contact cooling water in this sub-
category. The pollutants in each of these waste streams derive
from the contact of the water with particles of metal, so the
pollutants present are expected to be similar. However, because
the air pollution control device is designed to capture small
particles and gases (dust and fumes) generated during the casting
process, the mass loadings of total suspended solids and total
dissolved solids are expected to be higher in casting wet air
424
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pollution control blowdown than in shot casting contact cooling
water.
Metal Powder Production Atomization Wastewater. As discussed in
Section III, metal powder is commonly produced through wet atomi-
zation of a molten metal. Water is removed after the atomization
step, commonly by settling, then discharged.
No samples of metal powder production atomization wastewater were
collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to shot casting contact cooling water in this
subcategory. These two waste streams are generated by using
water to cool molten metal. Therefore, the pollutants present in
each waste stream and the mass loading (mg/kkg) at which they are
present should be similar.
Metal Powder Production Ball Milling Wastewater. As discussed in
Section III,metal powderscan be produced by milling with water,
most commonly wet ball milling. After the wet milling operation,
excess water is extracted from the metal powder, commonly by set-
tling, and then discharged.
No samples of metal powder production ball milling wastewater
were collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to tumbling wastewater in this subcategory. These
two waste streams are generated from similar physical processes
using water for similar purposes, so the pollutants present are
expected to be similar. However, because process chemicals (rust
inhibitors, detergents) are sometimes added to tumbling water,
the mass of loadings of total dissolved solids are expected to be
higher in tumbling wastewater than in metal powder production
ball milling wastewater.
Pressure Bonding Contact Cooling Water. As discussed in Section
III,metalscan be bonded together through the use of pressure
applied onto the desired forms. Cooling water may be applied
after the bonding operation to facilitate handling of the bonded
product.
One sample of pressure bonding contact cooling water was col-
lected at one plant. Elevated concentrations of zinc (3.42 mg/1)
and copper (7.85 mg/1) were detected in the sample.
Annealing Contact Cooling Water. As discussed in Section III,
annealing is used by plants in the nonferrous metals forming
category to remove the effects of strain hardening or solution
heat treatment. Once removed from the annealing furnace, it is
essential that the heat-treatable alloys be cooled at a control-
led rate. Contact cooling water may be used for this purpose.
425
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No samples of annealing contact cooling water were collected dur-
ing the screen sampling program. However, the Agency believes
that this stream will have wastewater characteristics similar to
semi-continuous and continuous casting contact cooling water in
this subcategory. These two waste streams are generated by using
water, without additives, to cool hot metal. Therefore, the
pollutants present in each waste stream and the mass loading at
which they are present should be similar.
Surface Treatment Spent Baths. As discussed in Section III, a
number of chemical treatments may be applied after the forming of
precious metals products. The surface treatment baths must be
periodically discharged after their properties are exhausted.
No samples of surface treatment spent baths were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to sur-
face treatment rinsewater in this subcategory. As a precious
metal piece is removed from a surface treatment bath, it carries
with it a small volume of the bath. The rinsewater used to
remove the carried-over bath solution from the formed piece will
contain the same pollutants as the bath, only at lower concentra-
tion. Therefore, the pollutants present in precious metals
surface treatment baths are expected to be identical to the
pollutants in precious metals surface treatment rinsewater,
except that the mass loadings of dissolved metals and total
suspended solids are expected to be higher in surface treatment
spent baths than in surface treatment rinsewater.
Surface Treatment Rinsewater. As discussed in Section III, rins-
ing followsthe surface treatment process to prevent the solution
from affecting the surface of the metal beyond the desired
amount.
Four samples of surface treatment rinsewater were collected from
two streams at two plants. Elevated concentrations of silver
(6.70 mg/1), zinc (4.66 mg/1), cadmium (11.1 mg/1), copper (60.6
mg/1), and TSS (3,000 mg/1) were detected in the samples.
Alkaline Cleaning Spent Baths. As discussed in Section III,
alkaline cleaners are formulations of alkaline salts, water, and
surfactants. Spent solutions are discharged from alkaline clean-
ing processes after their properties are exhausted.
No samples of alkaline cleaning spent baths were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to alka-
line cleaning spent baths in the nickel/cobalt subcategory.
These two waste streams are generated by identical physical pro-
cesses which use similar process chemicals. The only difference
426
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should be the metals present. The mass loading of precious
metals in precious metals alkaline cleaning spent baths should be
similar to the mass loading of nickel in nickel alkaline cleaning
baths, and vice versa. Also, chromium should not be present in
significant amounts. The other pollutants present in each waste
stream, and the mass loading at which they are present, should be
similar.
Alkaline Cleaning Rinsewater. As discussed in Section III, fol-
1owing alkaline treating, metal parts are rinsed. Rinses are
discharged from alkaline cleaning processes.
No samples of alkaline cleaning rinsewater were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to alka-
line cleaning rinsewater in the nickel/cobalt subcategory. These
two waste streams are generated by identical physical processes
which use similar process chemicals. The only difference should
be the metals present. The mass loading of precious metals in
precious metals alkaline cleaning rinsewater should be similar to
the mass loading of nickel in nickel alkaline cleaning rinse-
water, and vice versa. Also, chromium should not be present in
significant amounts. The other pollutants present in each waste
stream, and the mass loading at which they are present, should be
similar.
Prebonding Cleaning Wastewater. As discussed in Section III,
prior to bonding, metal surfaces must be cleaned in order to
obtain a good bond. The main source of process water in metal
cladding operations is in cleaning the metal surfaces prior to
bonding. Acid, caustic, or detergent cleaning can be performed
depending on the metal type. For small batch operations, the
cleaning steps can involve dipping the metal into small cleaning
bath tanks and hand rinsing the metal in a sink. For larger con-
tinuous operations, the metal may be cleaned in a power scrubline
In a typical scrubline, the strip passes through a detergent
bath, spray rinse, acid bath, spray rinse, rotating abrasive
scrub brushes, and a final rinse. The metal may then pass
through a heated drying chamber or may air dry.
Eight samples of prebonding cleaning wastewater were collected
from three streams at two plants. Elevated concentrations of
silver (0.100 mg/1), zinc (2.32 mg/1), copper (5.95 mg/1),
cyanide (0.28 mg/1), nickel (3.60 mg/1), oil and grease (16
mg/1), and TSS (400 mg/1) were detected in the samples.
Tumbling Wastewater. As discussed in Section III, tumbling is a
controlled method of processing parts to remove burrs, scale,
flash, and oxides as well as to improve surface finish of formed
metal parts. Water is commonly added to the tumbling container
and later discharged.
427
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Four samples of tumbling wastewater were collected from two
streams at two plants. Elevated concentrations of silver (0.220
mg/1), lead (1.85 mg/1), zinc (3.16 mg/1), iron (7,850 mg/1),
copper (142 mg/1), nickel (3.25 mg/1), chromium (3.18 mg/1), oil
and grease (40 mg/1), and TSS (110 mg/1) were detected in the
samples.
Burnishing Wastewater. As discussed in Section III, burnishing
is the process of finish sizing or smooth finishing a workpiece
(previously machined or ground) by displacement, rather than
removals of minute surface irregularities. Water is commonly
used to aid in this operation.
No samples of burnishing wastewater were collected during the
screen sampling program. However, the Agency believes that this
stream will have wastewater characteristics similar to tumbling
wastewater in this subcategory. These two waste streams are
generated from similar physical processes which use water for
similar purposes. Therefore, the pollutants present in each
waste stream and the mass loading (mg/kkg) at which they are
present should be similar.
Sawing/Grinding Spent Emulsions. As discussed in Section III,
the rolls used in rolling operations obtain surface abrasions
after repeated use. The rolls must be surface ground in order to
obtain a smooth rolling surface. The rolled product will not be
formed properly if the rolls are not adequately smooth. Roll
grinding and other sawing and grinding operations generally
require a lubricant to minimize friction and act as a coolant.
Oil-in-water emulsions are commonly used for this purpose. The
emulsions are typically recycled using in-line filtration and
batch discharged periodically after their lubricating properties
are exhausted.
A sample of roll grinding spent emulsions was collected at one
plant. Elevated concentrations of zinc (0.920 mg/1), chromium
(0.240 mg/1), and oil and grease (500 mg/1) were detected in the
sample.
Degreasing Spent Solvents. As described in Section III, solvent
cleaners are used to remove lubricants (oils and greases) applied
to the surface of nonferrous metals during mechanical forming
operations. Basic solvent cleaning methods include straight
vapor degreasing, immersion-vapor degreasing, spray-vapor
degreasing, ultrasonic vapor degreasing, emulsified solvent
degreasing, and cold cleaning.
Solvents most commonly used for all types of vapor degreasing are
trichloroethylene, 1,1,1-trichloroethane, methylene chloride,
perchloroethylene, and various chlorofluorocarbons. Solvent
428
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selection depends on the required process temperature (solvent
boiling point), product dimension, and metal characteristics.
Contaminated vapor degreasing solvents are frequently recovered
by distillation. The sludge residue generated is toxic and may
be flammable, requiring appropriate handling and disposal pro-
cedures.
Since none of the plants surveyed reported discharging the vapor
degreasing spent solvents, no samples were collected.
Operations Which Do Not Use Process Water. The Agency proposes a
discharge allowance of zero for operations which do not generate
process wastewater. The following operations generate no process
wastewater, either because they use only noncontact cooling water
or because they use no water at all:
Forging, Swaging
Punching, Stamping
Welding
Soldering
Melting, Screening
Sawing
Slitting
Metal Powder Production
Metal Powder Production and Powder Metallurgy Iron, Copper, and
Aluminum Subcategory
Metal Powder Production Atomization Wastewater. As discussed in
Section III, wet atomization is a method of producing metal
powder in which a stream of water impinges upon a molten metal
stream, breaking it into droplets which solidify as powder par-
ticles. Water atomization is used to produce irregularly shaped
particles, required for powder metallurgy applications in which a
powder is cold pressed into a compact. Because cooling times
play an important role in determining particle configuration, the
atomized metal droplets are sometimes rapidly cooled by falling
into a water bath. Atomization and quench water are separated
from the metal powder by gravity settling or filtration and
discharged.
No samples of iron, copper or aluminum atomization wastewater
were collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to tumbling, burnishing, and cleaning wastewater
in this subcategory. These two waste streams are generated from
operations using water, usually without added process chemicals,
in contact with finely divided metal. The pollutants present in
each waste stream and the mass loading at which they are present
should be similar, except for total suspended solids and oil and
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grease. Oil and grease, present in high concentrations in clean-
ing wastewater, is not expected to be present in significant
concentrations in metal powder production atomization wastewater.
Because metal powders are more finely divided than the parts
tumbled and in higher concentration than the metal fines produced
during tumbling, the mass loading of total suspended solids is
expected to be higher in metal powder production atomization
wastewater than in tumbling, burnishing, and cleaning wastewater.
Metal Powder Production Milling Wastewater. As discussed in Sec-
tion III, metal powders are also produced by mechanical reduc-
tion. The most common pieces of mechanical reduction equipment
are ball mills, vortex mills, hammer mills, disc mills, and roll
mills.
Water or other liquids may be used to aid in the milling opera-
tion or to facilitate handling after powder is milled.
No samples of metal powder production milling wastewater were
collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to tumbling, burnishing, and cleaning wastewater
in this subcategory. These two waste streams are generated from
operations using water, usually without added process chemicals,
in contact with finely divided metal. The pollutants present in
each waste stream and the mass loading at which they are present,
should be similar, except for total suspended solids and oil and
grease. Oil and grease, present in high concentrations in clean-
ing wastewater, is not expected to be present in significant
concentrations in metal powder production milling wastewater.
Metal powders are more finely divided than tumbled parts.
Powders are also present in higher concentration than the metal
fines produced during tumbling. Therefore, the mass loading of
total suspended solids is expected to be higher in metal powder
production milling wastewater than in tumbling, burnishing, and
cleaning wastewater.
Metal Powder Production Wet Air Pollution Control Slowdown. As
discussed in Section III, during the production of metal powders,
particulates may become airborne. The use of wet air pollution
control may be necessary in order to meet particulate air quality
standards.
No samples of metal powder production wet air pollution control
blowdown were collected during the screen sampling program. How-
ever, the Agency believes that this stream will have wastewater
characteristics similar to blowdown from air pollution control
scrubbers used to control particulate emissions in the nickel/
cobalt subcategory. The only difference between the wastewater
characteristics of the two streams should be the metals present.
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The mass loading (mg/kkg) of iron, copper and/or aluminum in
iron, copper and aluminum metal powder production wet air pol-
lution control scrubber blowdown should be similar to the nickel
mass loading in nickel air pollution control scrubber blowdown,
and vice versa. The other pollutants present in each waste
stream and the mass loading at which they are present, should be
similar.
Sizing/Repressing Spent Lubricants. As discussed in Section III,
powder metallurgy parts may be sized or repressed after sintering
to increase the density of the part and/or to bring the part
closer to required tolerances. Lubricants, such as turbine oil,
may be used to prevent the adhesion of the part to the sizing
die. Since none of the plants surveyed reported discharging
sizing spent lubricants (they are completely consumed in the
process), no samples were collected.
Oil-Resin Impregnation wastewater. As discussed in Section III,
porous parts pressed from metalpowders may be impregnated with
oils or resins. Following impregnation, the parts may be rinsed
with water to remove excess oil or resin and the rinsewater may
be discharged.
No samples of oil-resin impregnation wastewater were collected
during the screen sampling program. However, the Agency believes
that this stream will have wastewater characteristics similar to
tumbling, burnishing, and cleaning wastewater in this subcate-
gory. These two waste streams are generated from similar physi-
cal processes in which water is used to clean formed parts.
Therefore, the pollutants present in each waste stream and the
mass loading (mg/kkg) at which they are present should be
similar.
Steam Treatment Wet Air Pollution Control Blowdown. As discussed
in Section III, steam treatment operations may require the use of
wet air pollution control devices in order to meet air quality
standards.
Three samples of steam treatment wet air pollution control blow-
down were collected from one stream at one plant. Elevated
concentrations of oil and grease (42 mg/1) and TSS (200 mg/1)
were detected in the samples.
Tumbling, Burnishing, and Cleaning Wastewater. As discussed in
Section III,tumblingisan operation in parts pressed from metal
powder are rotated in a barrel with ceramic or metal slugs or
abrasives to remove scale, fins, or burrs. It may be done dry or
with an aqueous solution. Burnishing is a surface finishing pro-
cess in which minute surface irregularities are displaced rather
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than removed. It also can be done by dry or in an aqueous solu-
tion. Pressed parts can also be cleaned in hot soapy water to
remove excess oil from oil quenching operations.
Six samples of tumbling wastewater were collected from three
streams at one plant. Four samples of cleaning wastewater were
collected from one stream at one plant. Elevated concentrations
of iron (211 mg/1), copper (253 mg/1), aluminum (34.3 mg/1),
cyanide (1.8 mg/1), lead (45.1 mg/1), nickel (3.00 mg/1), zinc
(9.56 mg/1), boron (440 mg/1), tin (15.8 mg/1), titanium (2.50
mg/1), oil and grease (2,100 mg/1), and TSS (3,000 mg/1) were
detected in the samples.
Sawing/Grinding Spent Lubricants. As discussed in Section III,
sawing/grinding operationsgenerally require a lubricant in order
to minimize friction and act as a coolant.
Two samples of sawing/grinding lubricants were collected from two
streams at one plant. Elevated concentrations of iron (176
mg/1), copper (1.55 mg/1), aluminum (7.00 mg/1), zinc (3.26
mg/1), boron (166 mg/1), cyanide (2.5 mg/1), oil and grease (720
mg/1), and TSS (120 mg/1) were detected in the samples.
Degreasing Spent Solvents. As described in Section III, solvent
cleaners are used to remove lubricants (oils and greases) applied
to the surface of metals during powder metallurgy operations.
Basic solvent cleaning methods include straight vapor degreasing,
immersion-vapor degreasing, spray-vapor degreasing, ultrasonic
vapor degreasing, emulsified solvent degreasing, and cold
cleaning.
Solvents most commonly used for all types of vapor degreasing are
trichloroethylene, 1,1,1-trichloroethane, methylene chloride,
perchloroethylene, and various chlorofluorocarbons. Solvent
selection depends on the required process temperature (solvent
boiling point), product dimension, and metal characteristics.
Contaminated vapor degreasing solvents are frequently recovered
by distillation. The sludge residue generated is toxic and may
be flammable, requiring appropriate handling and disposal pro-
cedures .
Since none of the plants surveyed reported discharging the vapor
degreasing spent solvents, no samples were collected.
Operations Which Do Not Use Process Water. The Agency proposes a
discharge allowance of zero for operations which do not generate
process wastewater. The following operations generate no process
wastewater because they use only noncontact cooling water or
because they use no water at all:
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Powder Metallurgy Operations (Compacting, Sintering)
Sanding
Rolling
Machining
Screening
Blending
Briquetting
Crushing, Pulverizing
Titanium Forming Subcategory
Cold Rolling Spent Lubricants. As discussed in Section III,
mineral oil or kerosene-based lubricants are typically used in
cold rolling. However, water soluble lubricants are also used in
titanium cold rolling.
No samples of cold rolling spent lubricants were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to roll-
ing spent emulsions in the nickel/cobalt subcategory. These two
waste streams are generated by identical physical processes which
use similar process chemicals. The only difference should be the
metals present. The mass loading (mg/kkg) of titanium in tita-
nium cold rolling spent lubricants should be similar to the mass
loading of nickel in nickel rolling spent emulsions, and vice
versa. Also, the mass loading of chromium should be insignifi-
cant because titanium is seldom alloyed with chromium. The other
pollutants present in each waste stream and the mass loading at
which they are present should be similar.
Hot Rolling Contact Lubricant-Coolant Water. As discussed in
Section III, it is necessary to use a lubricant-coolant during
rolling to prevent excessive wear on the rolls, to prevent adhe-
sion of metal to the rolls, and to maintain a suitable and uni-
form rolling temperature. Water is one type of lubricant-coolant
which may be used.
No samples of hot rolling contact lubricant-coolant water were
collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to rolling contact lubricant-coolant water in the
nickel/cobalt subcategory. These two waste streams are generated
by using water, without additives, to cool and lubricate metal
during the rolling process. The only difference between the
wastewater characteristics of the two streams should be the
metals present. The mass loading (mg/kkg) of titanium in
titanium hot rooling contact lubricant-coolant water should be
similar to the mass loading of nickel in nickel rolling contact
lubricant-coolant water, and vice versa. The other pollutants
present in each waste stream and the mass loading at which they
are present should be similar.
433
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Extrusion Spent Lubricants. As discussed in Section III, the
extrusion process requires the use of a lubricant to prevent
adhesion of the metal to the die and ingot container walls.
No samples of extrusion spent lubricants were collected during
the screen sampling program. However, the Agency believes that
discharged titanium extrusion lubricants will have wastewater
characteristics similar to rolling spent emulsions in the nickel/
cobalt subcategory. These two waste streams are generated from
operations which use similar process chemicals for similar pur-
poses (lubrication). The only difference between the wastewater
characteristics of the two streams should be the metals present.
The mass loading (mg/kkg) of titanium in titanium extrusion spent
lubricants should be similar to the mass loading of nickel in
nickel rolling spent emulsions, and vice versa. Also, the mass
loading of chromium should be insignificant because titanium is
seldom alloyed with chromium. The other pollutants in each waste
stream, and the mass loading at which they are present, should be
similar.
Forging Spent Lubricants. As discussed in Section III, either a
water or oil medium can be sprayed onto forging dies for proper
lubrication.
Since none of the plants surveyed reported wastewater discharge
values for forging spent lubricants, no samples were collected.
Forging Die Contact Cooling Water. As discussed in Section III,
forging dies may require cooling to maintain the proper die tem-
perature between forgings.
No samples of forging contact cooling water were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to forg-
ing die contact cooling water in the nickel/cobalt subcategory.
These two waste streams are generated by using water, without
additives, to cool forging dies. The only difference between the
wastewater characteristics of the two streams should be the
metals present. The mass loading (mg/kkg) of titanium in tita-
nium forging die contact cooling water should be similar to the
mass loading of nickel in nickel forging die contact cooling
water, and vice versa. Also, the mass loading of chromium should
be insignificant because titanium is seldom alloyed with chro-
mium. The other pollutants in each waste stream, and the mass
loading at which they are present, should be similar.
Forging Wet Air Pollution Control Blowdown. As discussed in Sec-
tion III, wet air pollution control devices are needed to control
air pollution from some operations. For instance, scrubbers may
be needed over forging operations where partial combustion of
oil-based lubricants may generate particulates and smoke.
434
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No samples of forging wet air pollution control blowdown were
collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to surface treatment wet air pollxition control
blowdown in this subcategory. These two waste streams are
generated by devices designed to control emission of airborne
pollutants. However, because airborne particulates are generated
at higher concentration from forging operations than surface
treatment operations, the mass loading of total suspended solids
is expected to be higher in forging wet air pollution control
blowdown than in surface treatment wet air pollution control
blowdown. The other pollutants present in each waste stream, and
the concentration at which they are present, are expected to be
similar.
Heat Treatment Contact Cooling Water. As discussed in Section
III, heat treatment is used by plants in the nonferrous metals
forming category to give the metal the desired mechanical prop-
erties. After heat treatment, the metals must be cooled at a
controlled rate. Contact cooling water may be used for this
purpose.
No samples of heat treatment contact cooling water were collected
during the screen sampling program. However, the Agency believes
that this stream will have wastewater characteristics similar to
annealing contact cooling water in the nickel/cobalt subcategory.
These two waste streams are generated by using water, without
additives, to cool hot metal. The only difference between the
wastewater characteristics of the two streams should be the
metals present. The mass loading (mg/kkg) of titanium in tita-
nium heat treatment contact cooling water should be similar to
the mass loading of nickel in nickel annealing contact cooling
water, and vice versa. Also, the mass loading of chromium should
be insignificant because titanium is seldom alloyed with chro-
mium. The other pollutants in each waste stream, and the mass
loading at which they are present, should be similar.
Surface Treatment Spent Baths. As discussed in Section III, a
number of chemical treatments may be applied after the forming of
titanium products. The surface treatment baths must be period-
ically discharged after their properties are exhausted.
Two samples of surface treatment spent baths were collected from
two streams at one plant. Elevated concentrations of titanium
(44,100 mg/1), aluminum (4,170 mg/1), iron (17,020 mg/1),
fluoride (86,000 mg/1), and TSS (1,920 mg/1) were detected in the
samples.
435
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Surface Treatment Rinsewater. As discussed in Section III, rins-
ing follows the surface treatment process to prevent the solution
from affecting the surface of the metal beyond the desired
amount.
Seven samples of surface treatment rinsewater were collected from
three streams at one plant. Elevated concentrations of titanium
(55.3 mg/1), iron (124 mg/1), fluoride (85.0 mg/1), and TSS (40
mg/1) were detected in the samples.
Surface Treatment Wet Air Pollution Control Blowdown. As dis-
cussed in Section III, wet air pollution control devices must
accompany some operations in order to meet air quality standards.
One sample of surface treatment wet air pollution control blow-
down was collected. Elevated concentrations of titanium (2.750
mg/1), iron (1.800 mg/1), fluoride (33 mg/1), and TSS (40 mg/1)
were detected in the samples.
Alkaline^ Cleaning Spent Baths. As discussed in Section III ,
alkalineT cleaning Is commonly used to clean formed metal parts.
Products can be cleaned with an alkaline solution either by
immersion or spray.
No samples of alkaline cleaning spent baths were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to
alkaline cleaning spent baths in the nickel/cobalt subcategory.
These two waste streams are generated from operations using simi-
lar process chemicals to clean formed metal products. The only
difference between the wastewater characteristics of the two
streams should be the metals present. The mass loading (mg/kkg)
of titanium in titanium alkaline cleaning spent baths should be
similar to the mass loading of nickel in nickel alkaline cleaning
spent baths, and vice versa. Also, the mass loading of chromium
should be insignificant because titanium is seldom alloyed with
chromium. The other pollutants in each waste stream, and the
mass loading at which they are present, should be similar.
Alkaline Cleaning Rinsewater. As discussed in Section III, rins-
ing followsthe alkaline cleaning process to prevent the solution
from drying on the product.
No samples of alkaline cleaning rinsewater were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to
alkaline cleaning rinsewater in the nickel/cobalt subcategory.
These two waste streams are generated from using water to remove
alkaline cleaning solutions from cleaned metal. The only differ-
ence between the wastewater characteristics of the two streams
436
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should be the metals present. The mass loading (mg/kkg) of tita-
nium in titanium alkaline cleaning rinsewater should be similar
to the mass loading of nickel in nickel alkaline cleaning rinse-
water, and vice versa. Also, the mass loading of chromium should
be insignificant because titanium is seldom alloyed with chro-
mium. The other pollutants in each waste stream, and the mass
loading at which they are present, should be similar.
Tumbling Wastewater. As described in Section III, tumbling is an
operation in which forgings are rotated in a barrel with ceramic
or metal slugs or abrasives to remove scale, fins, oxides, or
burrs. It may be done dry, with water, or an aqueous solution
containing cleaning compounds, rust inhibitors or other
additives.
One sample of tumbling wastewater was collected. Elevated
concentrations of titanium (156 mg/1), iron (111 mg/1), aluminum
(182 mg/1), boron (116 mg/1), fluoride (110 mg/1), ammonia (34
mg/1), cyanide (4.0 mg/1), oil and grease (17 mg/1), and TSS
(6,800 mg/1) were detected in the sample.
Sawing/Grinding Spent Lubricants. As discussed in Section III,
sawing/grinding operationsgenerally require a lubricant in order
to minimize friction and act as a coolant.
One sample of sawing/grinding spent lubricant was collected.
Elevated concentrations of titanium (6.00 mg/1), iron (17.5
mg/1), aluminum (33.0 mg/1), fluoride (110 mg/1), cyanide (3.8
mg/1), oil and grease (34 mg/1), and TSS (244 mg/1) were detected
in the sample.
Degreasing Spent Solvents. As described in Section III, solvent
cleaners are used to remove lubricants (oils and greases) applied
to the surface of nonferrous metals during mechanical forming
operations. Basic solvent cleaning methods include straight
vapor degreasing, immersion-vapor degreasing, spray-vapor
degreasing, ultrasonic vapor degreasing, emulsified solvent
degreasing, and cold cleaning.
Solvents most commonly used for all types of vapor degreasing are
trichloroethylene, 1,1,1-trichloroethane, methylene chloride,
perchloroethylene, and various chlorofluorocarbons. Solvent
selection depends on the required process temperature (solvent
boiling point), product dimension, and metal characteristics.
Contaminated vapor degreasing solvents are frequently recovered
by distillation. The sludge residue generated is toxic and may
be flammable, requiring appropriate handling and disposal pro-
cedures.
Since none of the plants surveyed reported discharging the vapor
degreasing spent solvents, no samples were collected.
437
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Operations Which Do Not Use Process Water. The Agency proposes a
discharge allowance of zero for operations which do not generate
process wastewater. The following operations generate no process
wastewater, because they use only noncontact cooling water or
because they use no water at all:
Casting
Shot Blasting
Grit Blasting
Machining
Torching
Deoxidizing
Straightening
Trimming
Piercing
Shearing
Refractory Metals Forming Subcategory
Rolling Spent Neat Oils. As discussed in Section III, the roll-
ing of refractory metal products typically requires the use of
mineral oil lubricants. The oils are usually recycled with
in-line filtration and periodically disposed of by sale to an oil
reclaimer or by incineration. Because discharge of this stream
is not practiced, flow data were not available for analysis.
Only one plant surveyed reported using neat oil rolling lubri-
cants, but this plant did not report the quantity of lubricant
used.
Since none of the plants surveyed reported discharging the roll-
ing spent neat oils, no samples were collected.
Rolling Spent Emulsions. As discussed in Section III, oil-in-
water emulsions are used in rolling operations as coolants and
lubricants. Rolling emulsions are typically recycled using
in-line filtration treatment and batch discharged periodically
when the lubricating properties of the emulsions are exhausted.
No samples of rolling spent emulsions were collected during the
screen sampling program. However, the Agency believes that this
stream will have wastewater characteristics similar to nickel/
cobalt rolling spent emulsions. These two waste streams are
generated by identical physical processes which use similar
process chemicals. The only difference between the wastewater
characteristics of the two streams should be the metals present.
The mass loading (mg/kkg) of refractory metals rolling spent
emulsions should be similar to the mass loading of nickel in
nickel rolling spent emulsions, and vice versa. In addition, the
mass loading of chromium in refractory metals rolling spent emul-
sions should be insignificant because refractory metals are
seldom alloyed with chromium. The other pollutants in each waste
stream, and the mass loading at which they are present, should be
similar.
438
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Drawing Spent Lubricants. As discussed in Section III, a wide
variety of drawinglubricants are used in order to ensure uniform
drawing temperatures and avoid excessive wear on the dies and
mandrels. Drawing lubricants are usually recycled until no
longer effective.
Since none of the plants surveyed reported discharging the draw-
ing spent lubricants, no samples were collected.
Extrusion Press and Solution Heat Treatment Contact Cooling
Water.As discussed in Section III, heat treatment isfrequently
used after extrusion to attain the desired mechanical properties.
Heat treated products are primarily cooled by contact with water.
No samples of extrusion heat treatment contact cooling water were
collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to nickel/cobalt press and solution heat treatment
contact cooling water. These two waste streams are generated by
using water, without additives, to cool hot metal. The only dif-
ference between the wastewater characteristics of the two streams
should be the metals present. The mass loading (mg/kkg) of
refractory metals in refractory metals extrusion press and solu-
tion heat treatment contact cooling water should be similar to
the mass loading of nickel in nickel extrusion press and solution
heat treatment contact cooling water, and vice versa. In addi-
tion, the mass loading of chromium in refractory metals extrusion
press and solution heat treatment contact cooling water should be
insignificant because refractory metals are seldom alloyed with
chromium. The other pollutants in each waste stream, and the
mass loading at which they are present, should be similar.
Extrusion Press Hydraulic Fluid Leakage. As discussed in Section
III, due to the large force applied by a hydraulic press,
hydraulic fluid leakage is unavoidable.
One sample of extrusion press hydraulic fluid leakage was col-
lected during the screen sampling program. Elevated concentra-
tions of copper (21 mg/1), molybdenum (20 mg/1), oil and grease
(44,000 mg/l), and total suspended solids (19,000 mg/1) were
detected in the sample.
Forging Spent Lubricants. As discussed in Section III, proper
lubrication of the dies is essential in forging refractory
metals. Of the plants surveyed reporting the use of forging
lubricants, both reported total consumption due to evaporation
and drag-out.
Since none of the plants surveyed reported discharging the forg-
ing spent lubricants, no samples were collected.
439
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Forging Solution Heat Treatment Contact Cooling Water. As dis-
cussed in Section III, heat treatment isfrequently used after
forging to attain the desired mechanical properties in the forged
metal. Contact cooling water may be used to cool the alloy at a
controlled rate after heat treatment.
No samples of forging solution heat treatment contact cooling
water were collected during the screen sampling program. How-
ever, the Agency believes that this stream will have wastewater
characteristics similar to nickel/cobalt extrusion press and
solution heat treatment contact cooling water. These two waste
streams are generated by using water, without additives, to cool
hot metal. The only difference between the wastewater character-
istics of the two streams should be the metals present. The mass
loading (mg/kkg) of refractory metals in refractory metals
forging solution heat treatment contact cooling water should be
similar to the mass loading of nickel in nickel extrusion press
and solution heat treatment contact cooling water, and vice
versa. Also, the mass loading of chromium should be insignifi-
cant because refractory metals are seldom alloyed with chromium.
The other pollutants in each waste stream, and the mass loading
at which they are present, should be similar.
Extrusion and Forging Equipment Cleaning Wastewater. As dis-
cussed in Section III,extrusion and forging equipment should be
periodically cleaned in order to prevent the excessive build-up
of oil and grease on the dies.
No samples of extrusion and forging equipment cleaning wastewater
were collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to nickel forging die contact cooling water.
These two waste streams are generated from similar physical
processes (flushing a forging die with water) so the pollutants
present are expected to be similar. However, the water is used
for different purposes, in one case to cool a hot die, in the
other, to remove built-up contaminants. Therefore, the mass
loadings of oil and grease are expected to be higher in forging
equipment cleaning wastewater than in forging die contact cooling
water. In addition, the metals present in the two waste streams
are expected to differ. The only difference between the waste-
water characteristics of the two streams should be the metals
present. The mass loading (mg/kkg) of refractory metals in
refractory metals extrusion and forging equipment cleaning waste-
water should be similar to the mass loading of nickel in nickel
forging die contact cooling water, and vice versa. Also, the
mass loading of chromium should be insignificant because refrac-
tory metals are seldom alloyed with chromium. The other pollu-
tants in each waste stream, and the mass loading at which they
are present, should be similar.
440
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Met:al Powder Production Wastewater. As discussed in Section III,
refractory metal powders are frequently produced by mechanical
reduction. The most common pieces of mechanical reduction equip-
ment are ball mills, vortex mills, hammer mills, disc mills, and
roll mills. Water or other liquids may be used to aid in the
milling operation or to facilitate handling after powder is
milled. One plant reported discharging wastewater from a ball
milling operation.
No samples of metal powder production milling wastewater were
collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to tumbling/burnishing wastewater in this subcate-
gory. These two waste streams are generated from operations
using water, often without added process chemicals, in contact
with finely divided metal. The pollutants present in each waste
stream and the mass loading at which they are present, should be
similar, except for total suspended solids. Metal powders are
more finely divided than tumbled parts. Powders are also present
in higher concentration than the metal fines produced during
tumbling. Therefore, the mass loading of total suspended solids
is expected to be higher in metal powder production milling
wastewater than in tumbling/burnishing wastewater.
Metal Powder Production Wet Air Pollution Control Slowdown. As
discussed in Section III,particulates may become airborne during
the production of metal powders. Wet air pollution control
equipment may be necessary to capture these particles in order to
meet particulate air quality standards.
No samples of metal powder production wet air pollution control
blowdown were collected during the screen sampling program. How-
ever, the Agency believes that this stream will have wastewater
characteristics similar to blowdown from air pollution control
scrubbers used to control particulates in the nickel/cobalt
subcategory. These two waste streams are generated by air
pollution devices used to remove particulate contaminants from
air. The only difference between the wastewater characteristics
of the two streams should be the metals present. The mass load-
ing (mg/kkg) of refractory metals in refractory metals powder
production wet air pollution control scrubber blowdown should be
similar to the nickel mass loading in nickel shot blaster scrub-
ber blowdown, and vice versa. In addition, the mass loading of
chromium should be insignificant because refractory metals are
seldom alloyed with chromium. The other pollutants present in
each waste stream and the mass loading at which they are present
should be similar.
Metal Powder Pressing Spent Lubricants. As discussed in Section
III,lubricants may be needed in the fabrication step in which
441
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metal powders are compacted in a closed die to produce a final
shape. Since none of the plants surveyed reported discharging
metal powder pressing spent lubricants, no samples were
collected.
Casting Contact Cooling Water. As discussed in Section III,
casting may require the use of contact cooling water in order to
achieve the desired physical properties of the metal. Since the
one plant reporting the use of casting contact cooling water
reported complete evaporation, no samples were collected.
Post-Casting Billet Washwater. Refractory metals billets may be
washed after casting to remove an oxide layer on the billet
formed at the elevated casting temperatures. The one surveyed
plant reporting the use of post-casting washwater did not
recirculate the water.
No samples of post-casting washwater were collected during the
screen sampling program. However, the Agency believes that this
stream will have wastewater characteristics similar to beryllium
billet washing wastewater. These two waste streams are generated
by using water, without additives, to clean a cast billet. The
only difference between the wastewater characteristics of the two
streams should be the metals present. The mass loading (mg/kkg)
of refractory metals in refractory metals post-casting billet
washwater should be similar to the mass loading of beryllium in
beryllium billet washing wastewater, and vice versa. The other
pollutants in each waste stream, and the mass loading at which
they are present, should be similar.
Surface Treatment Spent Baths. As discussed in Section IH? a
number of chemical treatments may be applied after the forming of
refractory metal products. The surface treatment baths must be
periodically discharged after their properties are exhausted.
One sample of surface treatment spent baths was collected. Ele-
vated concentrations of nickel (12.4 mg/1), copper (6.3 mg/1),
silver (6.1 mg/1), and TSS (140 mg/1) were detected in the sam-
ple.
Surface Treatment Rinsewater. As discussed in Section III, rins-
ing follows the surface treatment process to prevent the solu-
tion from affecting the surface of the metal beyond the desired
amount.
Four samples of surface treatment rinsewater were collected from
four streams at three plants. Elevated concentrations of alumi-
num (6.8 mg/1), fluoride (1,018 mg/1), and TSS (80 mg/1) were
detected in the samples.
442
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Surface Treatment Wet Air Pollution Control Slowdown. As dis-
cussed in Section 111, wet air pollution control devices are
needed to accompany some operations in order to meet quality
standards.
One sample of surface treatment wet air pollution control blow-
down was collected. Elevated concentrations of fluoride (130
mg/1) and TSS (150 mg/1) were detected in the sample.
Surface Coating Wet Air Pollution Control Slowdown. As discussed
in Section IIl7 wet air pollution control devices are needed to
control air pollution from some operations.
No samples of coating wet air pollution control blowdown were
collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to surface treatment wet air pollution control
blowdown in this subcategory. These two waste streams derive
from air pollution control operations used to collect and concen-
trate airborne contaminants. The contaminants generated by
surface coating are expected to be similar to the contaminants
generated by other surface treatments. Therefore, the pollutants
present in each waste stream, and the mass loading at which they
are present, should be similar.
Alkaline Cleaning Spent Baths. As discussed in Section III,
alkaline cleaners are formulations of alkaline salts, water, and
surfactants. Spent solutions are discharged from alkaline clean-
ing processes.
No samples of alkaline cleaning spent baths were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to
alkaline cleaning spent baths in the nickel/cobalt subcategory.
These two waste streams are generated by identical physical pro-
cesses which use similar process chemicals. The only difference
between the wastewater characteristics of the two streams should
be the metals present. The mass loading (mg/kkg) of refractory
metals in refractory metals alkaline cleaning spent baths should
be similar to the mass loading of nickel in nickel alkaline
cleaning spent baths, and vice versa. Also, the mass loading of
chromium should be insignificant because refractory metals are
seldom alloyed with chromium. The other pollutants in each waste
stream, and the mass loading at which they are present, should i e
similar.
Alkaline Cleaning Rinsewater. As discussed in Section III, fol-
lowing alkaline treating, metal parts are rinsed. Rinses are
discharged from alkaline cleaning processes.
443
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No samples of alkaline cleaning rinsewater were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to
alkaline cleaning rinsewater in the nickel/cobalt subcategory.
These two waste streams are generated by using water to remove
alkaline cleaning solutions from cleaned metal. The only differ-
ence between the wastewater characteristics of the two streams
should be the metals present. The mass loading (mg/kkg) of
refractory metals in refractory metals alkaline cleaning rinse-
water should be similar to the mass loading of nickel in nickel
alkaline cleaning rinsewater, and vice versa. Also, the mass
loading of chromium should be insignificant because refractory
metals are seldom alloyed with chromium. The other pollutants
in each waste stream, and the mass loading at which they are
present, should be similar.
Molten Salt Spent Baths. As discussed in Section III, molten
salt baths are used to descale refractory metal alloys. Formed
parts to be descaled are immersed in the bath for up to 15
minutes, removed, and water-quenched. Since none of the plants
surveyed reported discharging the molten salt spent baths, no
samples were collected.
Molten Salt Rinsewater. As discussed in Section III, when molten
salt baths are used to descale refractory metal alloys, they are
generally followed by a water quench/rinse step.
Four samples of molten salt rinsewater were collected from two
streams at one plant. Elevated concentrations of boron (7.0
mg/1), and TSS (285 mg/1) were detected in the samples.
Tumbling/Burnishing Wastewater. As discussed in Section III,
tumbling is a controlled method of processing parts to remove
burrs, scale, flash, and oxides as well as to improve surface
finish. Burnishing is the process of finish sizing or smooth
finishing a workpiece (previously machined or ground) by dis-
placement, rather than removal, of minute surface irregularities.
Water is used to facilitate tumbling and burnishing.
Five samples of tumbling/burnishing wastewater were collected
from three streams at one plant. Elevated concentrations of
nickel (35.9 mg/1), copper (4.16 mg/1), aluminum (13.1 mg/1), and
TSS (1,860 mg/1) were detected in the samples.
Sawing/Grinding Spent Neat Oils. As discussed in Section III,
sawing/grinding operations may use mineral-based oils or heavy
grease as the lubricant required to minimize friction and act as
a coolant. Normally, saw oils are not discharged as a wastewater
stream. Since none of the plants surveyed reported discharging
the sawing spent neat oils, no samples were collected.
444
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Saving/Grinding Spent Emulsions. As discussed in Section III,
sawing/grinding operations generally require a lubricant in order
to minimize friction and act as a coolant. Oil-in-water emul-
sions are frequently used to lubricate sawing and grinding
operations. The emulsions are usually recycled with in-line
filtration to remove swarf and batch discharged periodically as
their lubricating properties are exhausted.
No samples of sawing/grinding spent emulsions were collected
during the screen sampling program. However, the Agency believes
that this stream will have wastewater characteristics similar to
nickel/cobalt sawing/grinding spent lubricants in this subcate-
gory. These two waste streams are generated by identical physi-
cal processes which use similar process chemicals. The only
difference between the wastewater characteristics of the two
streams should be the metals present. The mass loading (mg/kkg)
of refractory metals in refractory metals sawing/grinding spent
emulsions should be similar to the mass loading of nickel and
cobalt in nickel/cobalt sawing/grinding spent emulsions, and vice
versa. Also, the mass loading of chromium in this waste stream
should be insignificant because refractory metals are seldom
alloyed with chromium. The other pollutants in each waste
stream, and the mass loading at which they are present, should be
similar.
Sawing/Grinding Contact Lubricant-Coolant Water. As discussed in
Section III,a lubricant-coolant is frequently needed during
sawing/grinding. Water is one type of lubricant-coolant which
may be used.
Two samples of sawing/grinding contact lubricant-coolant water
were collected from two streams at two plants. Elevated concen-
trations of molybdenum (5,470 mg/1), iron (13.0 mg/1), and TSS
(310 mg/1) were detected in the samples.
Sawing/Grinding Wet Air Pollution Control Blowdown. As discussed
in Section III, wet air pollution control devices are needed to
accompany some operations in order to meet quality standards.
No samples of sawing/grinding wet air pollution control blowdown
were collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to surface treatment wet air pollution control
blowdown in this subcategory. These two waste streams derive
from air pollution control operations used to collect and con-
centrate airborne contaminants. Since sawing/grinding operations
are expected to generate more airborne particulates than surface
treatment, the mass loading of total suspended solids is expected
to be higher in sawing/grinding wet air pollution control blow-
down than in surface treatment wet air pollution control blow-
down. The other pollutants in each waste stream, and the mass
loading at which they are present, should be similar.
445
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F o s t - Sawing/Grinding Rinsewater. As discussed in Section III,
the formed metals may be rinsed following sawing/grinding to
remove the lubricants and saw chips for reprocessing.
No samples of post-sawing/grinding rinsewater were collected
during the screen sampling program. However, the Agency believes
that this stream will have wastewater characteristics similar to
sawing/grinding contact lubricant-coolant water in this subcate-
gory. Since the pollutants in each of these waste streams are
generated from sawing and grinding operations, the pollutants
present in each waste stream and the mass loading at which they
are present should be similar.
Product Testing Wastewater. As described in Section III, testing
operations are used to check nonferrous metals parts for surface
defects or subsurface imperfections. Testing operations are
sources of wastewater because the spent water bath or test media
must be^periodically discarded due to the transfer into the test-
ing media of oil and grease, solids, and suspended and dissolved
metals from each product tested.
One sample of product testing wastewater was collected during the
screen sampling program. Elevated concentrations of nickel U.6
mg/1), oil and grease (72 mg/1), and total suspended solids (22
mg/1) were detected in the sample.
Degreasing Spent Solvents. As described in Section III, solvent
cleaners are used to remove lubricants (oils and greases) applied
to the surface of nonferrous metals during mechanical forming
operations. Basic solvent cleaning methods include straight
vapor degreasing, immersion-vapor degreasing, spray-vapor
degreasing, ultrasonic vapor degreasing, emulsified solvent
degreasing, and cold cleaning.
Solvents most commonly used for all types of vapor degreasing are
trichloroethylene, 1,1,1-trichloroethane, methylene chloride,
perchloroethylene, and various chlorofluorocarbons. Solvent
selection depends on the required process temperature (solvent
boiling point), product dimension, and metal characteristics.
Contaminated vapor degreasing solvents are frequently recovered
by distillation. The sludge residue generated is toxic and may
be flammable, requiring appropriate handling and disposal pro-
cedures .
Since none of the plants surveyed reported discharging the vapor
degreasing spent solvents, no samples were collected.
Operations Which J3^_Not__Use Process Water_. The Agency proposes a
discharge alTowance o~F zero "Tor "operations which do not generate
process wastewater. The following operations generate no process
446
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wastewater, because they use only noncontact cooling water or
because they use no water at all:
Powder Metallurgy Operations (Pressing, Sintering)
Annealing
Soldering
Welding
Screening
Blending
Straightening
Blasting
Zirconium/Hafnium Forming Subcategory
Drawing Spent Lubricants. As discussed in Section III, a suita-
blelubricantis required to ensure uniform drawing temperatures
and avoid excessive wear on the dies and mandrels used. A wide
variety of lubricants can be used.
Since none of the plants surveyed reported discharging the draw-
ing spent lubricants, no samples were collected.
Extrusion Spent Emulsions. As discussed in Section III, the
extrusion process requires the use of a lubricant to prevent
adhesion of the metal to the die and ingot container walls.
No samples of extrusion spent emulsions were collected during the
screen sampling program. However, the Agency believes that this
stream will have wastewater characteristics similar to nickel/
cobalt rolling spent emulsions. These two waste streams are
generated from operations which use similar process chemicals for
similar purposes (lubrication). The only difference between the
wastewater characteristics of the two streams should be the
metals present. The mass loading (mg/kkg) of zirconium/hafnium
in zirconium/hafnium extrusion spent emulsions should be similar
to the mass loading of nickel/cobalt in nickel/cobalt rolling
spent emulsions, and vice versa. The other pollutants in each
waste stream, and the mass loading at'which they are present,
should be similar.
Extrusion Press Hydraulic Fluid Leakage. As discussed in Section
lYI", due to the large force applied by a hydraulic press,
hydraulic fluid leakage is unavoidable.
No samples of extrusion press hydraulic fluid leakage were col-
lected during the screen sampling program. However, the Agency
believes that this stream will have wastewater characteristics
similar to nickel/cobalt forging, extrusion, and isostatic press
hydraulic fluid leakage. The pollutants present in these two
waste streams are attributable to the hydraulic fluid used, not
447
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the metal formed. Therefore, the pollutants present, and the
concentration (mg/1) at which they are present, should be
similar.
Extrusion Heat Treatment Contact Cooling Water. As discussed in
Section III, heat treatment is frequently used after extrusion to
attain the desired mechanical properties in the extruded metal.
Contact cooling water may be sprayed onto the metal as it emerges
from the die or press, or be contained in a bath for direct
quenching.
No samples of extrusion heat treatment contact cooling water were
collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to nickel/cobalt extrusion press and solution heat
treatment contact cooling water. These two waste streams are
generated by using water, without additives, to cool hot metal.
The only difference between the wastewater characteristics of the
two streams should be the metals present. The mass loading
(mg/kkg) of zirconium/hafnium in zirconium/hafnium extrusion
press and solution heat treatment contact cooling water should be
similar to the mass loading of nickel/cobalt in nickel/cobalt
extrusion press and solution heat treatment contact cooling
water, and vice versa. The other pollutants in each waste
stream, and the mass loading at which they are present, should be
similar.
Tube Reducing Spent Lubricants. As discussed in Section III,
tube reducing,much like rolling, may require a lubricating com-
pound in order to prevent excessive wear of the tube reducing
equipment, prevent adhesion of metal to the tube reducing equip-
ment, and maintain a suitable and uniform tube reducing tempera-
ture.
No samples of tube reducing spent lubricants were collected dur-
ing the screen sampling program. However, the Agency believes
that this stream will have wastewater characteristics similar to
nickel/cobalt tube reducing spent lubricants. These two waste
streams are generated by identical physical processes which use
similar process chemicals. The only difference between the
wastewater characteristics of the two streams should be the
metals present. The mass loading (mg/kkg) of zirconium/hafnium
in zirconium/hafnium tube reducing spent lubricants should be
simlar to the mass loading of nickel/cobalt in nickel/cobalt tube
reducing spent lubricants, and vice versa. The other pollutants
in each waste stream, and the mass loading at which they are
present, should be similar.
Forging Solution Heat Treatment Contact Cooling Water. As dis-
cussed in Section III,forging diesmay require cooling such that
the proper die temperature is maintained between forg;ings.
448
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No samples of forging solution heat treatment contact cooling
water were collected during the screen sampling program. How-
ever, the Agency believes that this stream will have wastewater
characteristics similar to nickel/cobalt extrusion press and
solution heat treatment contact cooling water. These two waste
streams are generated by using water, without additives, to cool
hot metal. The only difference between the wastewater character-
istics of the two streams should be the metals present. The mass
loading (mg/kkg) of zirconium/hafnium in zirconium/hafnium
forging solution heat treatment contact cooling water should be
similar to the mass loading of nickel/cobalt in nickel/cobalt
extrusion press and solution heat treatment contact cooling
water, and vice versa. The other pollutants in each waste
stream, and the mass loading at which they are present, should be
similar.
Surface Treatment Spent Baths. As discussed in Section III, a
number of chemical treatments may be applied after the forming of
zirconium/hafnium products including pickling and coating. The
surface treatment baths must be periodically discharged after
their properties are exhausted.
Two samples of forging surface treatment spent baths were col-
lected from two streams at one plant. Elevated concentrations of
antimony (5.5 mg/1), cyanide (0.273 mg/1), chromium (18 mg/1),
fluoride (11,800 mg/1), and ammonia (392.5 mg/1) were detected in
the samples.
Surface Treatment Rinsewater. As discussed in Section III, rins-
ingfollowsthe surface treatment process to prevent the solution
from affecting the surface of the metal beyond the desired
amount.
No samples of surface treatment rinsewater were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to sur-
face treatment spent baths in this subcategory. As a zirconium
or hafnium piece is removed from a surface treatment bath, it
carries a small volume of the bath with it. The rinsewater used
to remove the carried over bath solution from the formed metal
piece will contain the same pollutants as the bath, only in lower
concentration. Therefore, the pollutants present in zirconium/
hafnium surface treatment rinsewater are expected to be identical
to the pollutants present in zirconium/hafnium surface treatment
baths, except that the mass loadings of the pollutants are
expected to be lower.
Alkaline Cleaning Spent Baths. As discussed in Section III,
alkaline cleaners are formulations of alkaline salts, water, and
surfactants. Spent solutions are discharged from the alkaline
cleaning processes.
449
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No samples of alkaline cleaning spent baths were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to
nickel/cobalt alkaline cleaning spent baths. These two waste
streams are generated by identical physical processes which use
similar process chemicals. The only difference between the
wastewater characteristics of the two streams should be the
metals present. The mass loading (mg/kkg) of zirconium/hafnium
in zirconium/hafnium alkaline cleaning spent baths should be
similar to the mass loading of nickel/cobalt in nickel/cobalt
alkaline cleaning spent baths, and vice versa. The other pollu-
tants in each waste stream, and the mass loading at which they
are present, should be similar.
Alkaline Cleaning Rinsewater. As discussed in Section III,
following alkaline cleaning, metal parts are rinsed. Rinses are
discharged from alkaline cleaning processes.
No samples of alkaline cleaning rinsewater were collected during
the screen sampling program. However, the Agency believes that
this stream will have wastewater characteristics similar to
nickel/cobalt alkaline cleaning rinsewater. These two waste
streams are generated by identical physical processes which use
similar process chemicals. The only difference between the
wastewater characteristics of the two streams should be the
metals present. The mass loading (mg/kkg) of zirconium/hafnium
in zirconium/hafnium alkaline cleaning rinsewater should be
similar to the mass loading of nickel/cobalt in nickel/cobalt
alkaline cleaning rinsewater, and vice versa. The other pollu-
tants in each waste stream, and the mass loading at which they
are present, should be similar.
Sawing/Grinding Spent Lubricants. As discussed in Section III,
sawing/grinding operations generally require a lubricant in order
to minimize friction and act as a coolant.
No samples of sawing/grinding spent lubricants were collected
during the screen sampling program. However, the Agency believes
that this stream will have wastewater characteristics similar to
nickel/cobalt sawing/grinding spent lubricants. These two waste
streams are generated by identical physical processes which use
similar process chemicals. The only difference between the
wastewater characteristics of the two streams should be the
metals present. The mass loading (mg/kkg) of zirconium/hafnium
in zirconium/hafnium sawing/grinding spent lubricants should be
similar to the mass loading of nickel/cobalt in nickel/cobalt
sawing/grinding spent lubricants, and vice versa. The other
pollutants in each waste stream, and the mass loading at which
they are present, should be similar.
450
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Sawing/Grinding Wet Air Pollution Control Slowdown. As discussed
in Section 11J-7 wet air pollution control devices are needed to
control air pollution from some operations. Scrubbers are
frequently necessary over sawing/grinding operations where
particulates are a problem.
Since none of the plants surveyed reported discharging the
sawing/grinding wet air pollution control blowdown, no samples
were collected.
Degreasing Spent Baths. As discussed in Section III, immersion-
vapor degreasing is used to clean metal parts coated with large
quantities of oil, grease, or hard-to-remove soil. Solvents used
are the same as those used in straight vapor degreasing. Solu-
tions of organic solvent in water are also used for degreasing.
Since none of the plants surveyed reported discharging the
degreasing spent baths, no samples were collected.
Degreasing Rinsewater. As discussed in Section III, it is some-
times necessary to rinse degreased parts with water to meet cer-
tain product specifications.
No samples of degreasing rinsewater were collected during the
screen sampling program. However, the Agency believes that this
stream will have wastewater characteristics similar to nickel/
cobalt alkaline cleaning rinsewater. These two waste streams are
generated from rinsing formed parts which have been cleaned or
degreased. Each rinsewater will contain the same process chemi-
cals as the bath which it follows, plus contaminants introduced
into the bath by the cleaned or degreased metal piece. Degreas-
ing rinsewater may contain organic pollutants at low mass load-
ing; nickel/cobalt alkaline cleaning rinsewater will not. In
addition, the two waste streams will differ in metals present.
The mass loading (mg/kkg) of zirconium/hafnium in zirconium/haf-
nium degreasing rinesewater should be similar to the mass loading
of nickel/cobalt in nickel/cobalt alkaline cleaning rinsewater,
and vice versa. The other pollutants in each waste stream, and
the mass loading at which they are present, should be similar.
Operations Which Do Not Use Process Water. The Agency proposes a
discharge allowance of zero for operations which do not generate
process wastewater. The following operations generate no process
wastewater, because they use only noncontact cooling water or
because they use no water at all:
Rolling
Casting
Annealing
Shot Blasting
451
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Grit Blasting
Bead Blasting
Polishing
Straightening
Cutting, Trimming
Debarring, Sanding
Magnesium Forming Subcategory
Rolling Spent Emulsions. As discussed in Section III, oil-in-
water emulsions are used in rolling operations as coolants and
lubricants. Rolling emulsions are typically recycled using
in-line filtration treatment.
Since none of the plants surveyed reported wastewater discharge
values for rolling spent em Isions, no samples were collected.
Forging Spent Lubricants. As discussed in Section III, either
water, oil,or granulated carbon can be applied to forging dies
for proper lubrication. Since none of the plants surveyed
reported wastewater discharge values for forging spent
lubricants, no samples were collected.
Forging Solution Heat Treatment Contact Cooling Vater. As dis-
cussed in Section III, solution heat treatment is implemented
after forging to improve mechanical properties by maximizing the
concentration of hardening contaminants in solid solution. Solu-
tion heat treatment typically involves significant quantities of
contact cooling water.
No samples of forging solution heat treatment contact cooling
water were collected during the screen sampling program. How-
ever, the Agency believes that this stream will have wastewater
characteristics similar to extrusion press and solution heat
treatment contact cooling water in the lead/tin/bismuth subcate-
gory. These two waste streams are generated by using water,
without additives, to cool hot metal. The only difference
between the wastewater characteristics of the two streams should
be the metals present. The mass loading (mg/kkg) of magnesium in
magnesium forging solution heat treatment contact cooling water
should be similar to the mass loading of lead in lead/tin/bismuth
extrusion press and solution heat treatment contact cooling
water, and vice versa. Also, there should be no significant mass
loading of antimony in magnesium forging solution heat treatment
contact cooling water because magnesium is not commonly alloyed
with antimony. The other pollutants in each waste stream, and
the mass loading at which they are present, should be similar.
Forging Wet Air Pollution Control Blowdown. As discussed in
Section III, wet air pollution control devices are needed to
452
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control air pollution from some operations. For instance, scrub-
bers may be necessary when particulates and smoke are generated
from the partial combustion of oil-based lubricants as they
contact the hot forging dies.
No samples of forging wet air pollution control blowdown were
collected during the screen sampling program. However, the
Agency believes that this stream will have wastewater character-
istics similar to wet air pollution control blowdown in the
nickel/cobalt forming subcategory. These two waste streams
derive from air pollution control devices used to collect and
concentrate airborne contaminants, both gaseous and particulate.
The only difference between the wastewater characteristics of the
two streams should be the metals present. The mass loading
(mg/kkg) of magnesium in magnesium forging wet air pollution
control blowdown should be similar to the mass loading of nickel
in nickel wet air pollution control blowdown, and vice versa.
The other pollutants in each waste stream, and the mass loading
at which they are present, should be similar.
Forging Equipment Cleaning Wastewater. As discussed in Section
III, forging equipment should be periodically cleaned in order to
prevent the excessive buildup of oil, grease, and caked-on solid
lubricants on the forging die.
No samples of forging equipment cleaning wastewater were col-
lected during the screen sampling program. However, the Agency
believes that this stream will have wastewater characteristics
similar to alkaline cleaning rinsewater in the lead/tin/bismuth
subcategory. These two waste streams are generated by cleaning
operations which use similar process chemicals. Since granulated
coal and graphite suspensions are frequently used to lubricate
magnesium forging operations, magnesium forging equipment clean-
ing wastewater may contain higher mass loadings of total sus-
pended solids. In addition, the metals present in the two waste
streams should differ. The mass loading (mg/kkg) of magnesium in
magnesium forging equipment cleaning wastewater should be similar
to the mass loading of lead in lead/tin/bismuth alkaline cleaning
rinsewater, and vice versa. Also, there should be no significant
concentration of antimony in magnesium forging equipment cleaning
wastewater because magnesium is not commonly alloyed with anti-
mony. The other pollutants in each waste stream, and the mass
loading at which they are present, should be similar.
Direct Chill Casting Contact Cooling Water. As discussed in Sec-
tion III, contact cooling water is a necessary part of direct
chill casting. The cooling water may be contaminated by lubri-
cants applied to the mold before and during the casting process.
The one plant reporting the use of direct chill casting contact
cooling water discharges no water, therefore no samples of this
waste stream were collected.
453
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Surface Treatment Spent Bathjg. As discussed in Section III, a
number of chemical treatments may be applied after the forming of
magnesium products. The surface treatment baths must be period-
ically discharged after their properties are exhausted,,
Three samples of surface treatment spent baths were collected
from three streams at one plant. Elevated concentrations of mag-
nesium (9,150 mg/1), chromium (28,000 mg/1), zinc (89.0 mg/1),
aluminum (64 mg/1), ammonia (97 mg/1), oil and grease (47,000
mg/1), and TSS (160 mg/1) were detected in the samples.,
Surface Treatment Rinsewater. As discussed in Section III, rins-
ing follows the surface treatment process to prevent the solution
from affecting the surface of the metal beyond the desired
amount.
Twelve samples of surface treatment rinsewater were collected
from eight streams at one plant. Elevated concentrations of mag-
nesium (148 mg/1), zinc (2.1 mg/1), chromium (516 mg/1), ammonia
(81 mg/1), oil and grease (16 mg/1), and TSS (97 mg/1) were
detected in the samples.
Sawing/Grinding Spent Lubricants. As discussed in Section III,
sawing/grinding operationsgenerally require a lubricant in order
to minimize friction and act as a coolant. Since none of the
plants surveyed reported wastewater discharge values for
sawing/grinding spent lubricants, no samples of this waste stream
were collected.
Sanding and Repairing Wet Air Pollution Control Slowdown. As
discussed in Section III, wet air pollution control devices are
needed to control air pollution from some operations. For
instance, scrubbers are frequently necessary over sanding and
repairing operations where particulates are a problem.
No samples of sanding and repairing wet air pollution control
blowdown were collected during the screen sampling program.
However, the Agency believes that this stream will have waste-
water characteristics similar to shot blaster wet air pollution
control blowdown in the nickel/cobalt subcategory. These two
waste streams derive from air pollution control devices used to
collect and concentrate airborne particulates. The only differ-
ence between the wastewater characteristics of the two streams
should be the metals present. The mass loading (mg/kkg) of
magnesium in mangesium sanding and repairing wet air pollution
control blowdown should be similar to the mass loading of nickel
in nickel shot blaster wet air pollution control blowdown, and
vice versa. The other pollutants in each waste stream, and the
mass loading at which they are present, should be similar.
454
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Degreasing Spent Solvents. As described in Section III, solvent
cleaners are used to remove lubricants (oils and greases) applied
to the surface of nonferrous metals during mechanical forming
operations. Basic solvent cleaning methods include straight
vapor degreasing, immersion-vapor degreasing, spray-vapor
degreasing, ultrasonic vapor degreasing, emulsified solvent
degreasing, and cold cleaning.
Solvents most commonly used for all types of vapor degreasing are
trichloroethylene, 1,1,1-trichloroethane, methylene chloride,
perchloroethylene, and various chlorofluorocarbons. Solvent
selection depends on the required process temperature (solvent
boiling point), product dimension, and metal characteristics.
Contaminated vapor degreasing solvents are frequently recovered
by distillation. The sludge residue generated is toxic and may
be flammable, requiring appropriate handling and disposal pro-
cedures .
Since none of the plants surveyed reported discharging the vapor
degreasing spent solvents, no samples were collected.
Operations Which Do Not Use Process Water. The Agency proposes a
discharge allowance of zero for operations which do not generate
process wastewater. The following operations generate no process
wastewater, because they use only noncontact cooling water or
because they use no water at all:
Extrusion
Shot Blasting
Powder Atomization
Screening
Turning
Uranium Forming Subcategory
Extrusion Spent Lubricants. As discussed in Section III, the
extrusion process requires the use of a lubricant to prevent
adhesion of the metal to the die and ingot container walls.
Since none of the plants surveyed reported wastewater discharge
values for extrusion spent lubricants, no samples were collected.
Extrusion Tool Contact Cooling Water. As discussed in Section
III,following an extrusion,the dummy block drops from the press
and is cooled before being used again. Water is sometimes used
to quench the extrusion tools.
No samples of extrusion tool contact cooling water were collected
during the screen sampling program. However, the Agency believes
that this stream will have wastewater characteristics similar to
455
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forging die contact cooling water in the nickel/cobalt subcate-
gory. These two waste streams are generated by using water,
without added process chemicals, to cool metal forming equipment.
The only difference between the wastewater characteristics of the
two streams should be the metals present. The mass loading
(mg/kkg) of uranium in uranium extrusion tool contact cooling
water should be similar to the mass loading of nickel in nickel/
cobalt forging die contact cooling water, and vice versa. Also,
there should be no significant mass loading of chromium in ura-
nium extrusion tool contact cooling water because uranium is not
commonly alloyed with chromium. The other pollutants in each
waste stream, and the mass loading at which they are present,
should be similar.
Extrusion Press and Solution Heat Treatment Contact Cooling
Water.As discussed in Section III, heat treatment is frequently
used after extrusion to attain the desired mechanical properties
in the extruded metal. Contact cooling of the extrusion can be
accomplished in one of three ways: with a water spray near the
die, by immersion in a water tank adjacent to the runout table,
or by passing the metal through a water mill.
No samples of extrusion solution heat treatment contact cooling
water were collected during the screen sampling program. How-
ever, -the Agency believes that this stream will have wastewater
characteristics similar to extrusion press and solution heat
treatment contact cooling water in the nickel/cobalt subcategory.
These two waste streams are generated by using water, without
additives, to cool hot metal. The only difference between the
wastewater characteristics of the two streams should be the
metals present. The mass loading (mg/kkg) of uranium in uranium
extrusion press and solution heat treatment contact cooling water
should be similar to the mass loading of nickel in nickel extru-
sion press and solution heat treatment contact cooling water, and
vice versa. Also, there should be no significant mass loading of
chromium in uranium extrusion press and solution heat treatment
contact cooling water because uranium is not commonly alloyed
with chromium. The other pollutants in each waste stream, and
the mass loading at which they are present, should be similar.
Forging Spent Lubricants. As discussed in Section III, proper
lubrication of the dies is essential in forging nonferrous
metals. A colloidal graphite lubricant is commonly sprayed onto
the dies for this purpose.
Since none of the plants surveyed reported wastewater discharge
values for forging spent lubricants, no samples were collected.
Forging Solution Heat Treatment Contact Cooling Water. As dis-
cussed in Section III, forging dies may require cooling to main-
tain the proper die temperature between forgings.
456
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No samples of forging solution heat treatment contact cooling
water were collected during the screen sampling program. How-
ever, the Agency believes that this stream will have wastewater
characteristics similar to extrusion press and solution heat
treatment contact cooling water in the nickel/cobalt subcategory.
These two waste streams are generated by using water, without
additives, to cool hot metal. The only difference between the
wastewater characteristics of the two streams should be the
metals present. The mass loading (mg/kkg) of uranium in uranium
extrusion press and solution heat treatment contact cooling water
should be similar to the mass loading of nickel in nickel extru-
sion press and solution heat treatment contact cooling water, and
vice versa. Also, the mass loading of chromium in uranium
forging solution heat treatment contact cooling water should be
insignificant because uranium is not commonly alloyed with
chromium. The other pollutants in each waste stream, and the
mass loading at which they are present, should be similar.
Surface Treatment Spent Baths. As discussed in Section III, a
number of chemical treatments may be applied after forming ura-
nium products. The surface treatment baths must be periodically
discharged after their properties are exhausted.
No samples of surface treatment spent baths were collected during
the screen sampling program. However, one plant supplied a par-
tial analysis of its spent surface treatment baths on its dcp.
Elevated concentrations of uranium (266,162 mg/1), titanium
(3,353 mg/1), magnesium (246 mg/1), fluoride (231 mg/1), and
barium (1,272 mg/1) were reported.
Surface Treatment Rinsewater. As discussed in Section III, rins-
ing shouldfollow the surface treatment process to prevent the
solution from affecting the surface of the metal beyond the
desired amount.
No samples of surface treatment rinsewater were collected during
the screen sampling program. However, one plant supplied a par-
tial analysis of surface treatment rinsewater on its dcp. Ele-
vated concentrations of uranium (1,250 mg/1), titanium (18 mg/1),
and barium (41 mg/1) were reported.
Surface Treatment Wet Air Pollution Control Slowdown. As dis-
cussed in Section III, wet air pollution control devices are
needed to control air emissions from some operations in order to
meet air quality standards. Scrubbers are frequently needed to
control acid fumes from surface treatment operations.
No samples of surface treatment wet air pollution control blow-
down were collected during the screen sampling program. However,
457
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the Agency believes that this stream will have wastewater char-
acteristics similar to surface treatment wet air pollution con-
trol blowdown in the titanium forming subcategory. These two
waste streams derive from air pollution control devices used to
collect and concentrate acid fumes. The only difference between
the wastewater characteristics of the two streams should be the
metals present. The mass loading (mg/kkg) of uranium in uranium
surface treatment wet air pollution control blowdown should be
similar to the mass loading of titanium in titanium surface
treatment wet air pollution control scrubber blowdown, and vice
versa. The other pollutants in each waste stream, and the mass
loading at which they are present, should be similar.
Sawing/Grinding Spent Emulsions. As discussed in Section III,
sawing/grinding operations generally require a lubricant in order
to minimize friction and act as a coolant. The emulsions are
typically recirculated, with in-line filtration to remove swarf,
and periodically batch discharged as the lubricating properties
are exhausted.
No samples of sawing/grinding spent emulsions were collected dur-
ing the screen sampling program. However, the Agency believes
that this stream will have wastewater characteristics similar to
sawing/grinding spent lubricants in the nickel/cobalt subcate-
gory. These two waste streams are generated by identical physi-
cal processes which use similar process chemicals. The only
difference between the wastewater characteristics of the two
streams should be the metals present. The mass loading (mg/kkg)
of uranium in uranium sawing/grinding spent emulsions should be
similar to the mass loading of nickel in nickel sawing/grinding
spent emulsions, and vice versa. Also, the mass loading of
chromium in uranium sawing/grinding spent emulsions should be
insignificant because uranium is not commonly alloyed with
chromium. The other pollutants in each waste stream, and the
mass loading at which they are present, should be similar.
Post-Sawing/Grinding Rinsewater. As discussed in Section III,
following the sawing/grinding operations, the lubricant and par-
ticulates occasionally need to be rinsed off the formed metal.
No samples of post-sawing/grinding rinsewater were collected dur-
ing the screen sampling program. However, the Agency believes
that this stream will have wastewater characteristics similar to
sawing/grinding contact lubricant-coolant water in the refractory
metals subcategory. These waste streams are both derived from
sawing/grinding operations, so the only difference between the
wastewater characteristics of the two streams should be the
metals present. The mass loading (mg/kkg) of uranium in uranium
post-sawing/grinding rinsewater should be similar to the mass
loading of refractory metals in refractory metals sawing/grinding
458
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contact lubricant-coolant water, and vice versa. The other pol-
lutants in each waste stream, and the mass loading at which they
are present, should be similar.
Degreasing Spent Solvents. As described in Section III, solvent
cleaners are used to remove lubricants (oils and greases) applied
to the surface of nonferrous metals during mechanical forming
operations. Basic solvent cleaning methods include straight
vapor degreasing, immersion-vapor degreasing, spray-vapor
degreasing, ultrasonic vapor degreasing, emulsified solvent
degreasing, and cold cleaning.
Solvents most commonly used for all types of vapor degreasing are
trichloroethylene, 1,1,1-trichloroethane, methylene chloride,
perchloroethylene, and various chlorofluorocarbons. Solvent
selection depends on the required process temperature (solvent
boiling point), product dimension, and metal characteristics.
Contaminated vapor degreasing solvents are frequently recovered
by distillation. The sludge residue generated is toxic and may
be flammable, requiring appropriate handling and disposal pro-
cedures .
Since none of the plants surveyed reported discharging the vapor
degreasing spent solvents, no samples were collected.
Operations Which Do Not Use Process Water. The Agency proposes a
discharge allowance of zero for operations which do not generate
process wastewater. The following operations generate no process
wastewater, because they use only noncontact cooling water or
because they use no water at all:
Stationary Casting
Direct Chill Casting
Salt Solution Heat Treatment
459
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Table V-l
NUMBER OF SAMPLES PER WASTE STREAM, BY SUBCATEGORY
Waste Stream / / / /
Rolling spent nea t oils
Rolling spent emulsions
Rol 1 ing contact 1 ubr icant-e oo lant water
Rol 1 ing spent soap sol ut ions
Rolling solution nedt treatment contat t cooling water
Drawing spent neat oils
Drawing spent emul s ions
Drawing spent lubricants
Drawing spent soap solutions
Extrusion spent emul sions
Extrusion spent lubricants
Extrusion press and solution heat treatment contact
cooling water
Extrusion and forging press hydraulic fluid leakage
Extrusion tool contact cooling water
Forging, swaging spent neat oils
Forging, swaging spent emu 1 s ions
Forging spent lubricants
Forging solution heat treatment contat t cooling water
Forging die contact cooling water
Forging wet air pol lution control blowdoun
Forging equipment L 1 ean ing wastewater
Press ing spent lubricants
Tube reducing spent lubricants
Metal powder produc t ion wet atomiza t ion wastewa ter
Metal powder production milling wastewate r
Metal powder production wet air pol lution control
blowdown
Metal powder produc t ion wabtewater
Continuous strip casting contact cooling water
Semi-continuous ingot casting contact cool ing water
Direct chill casting contact cooling water
Shot casting contact cooling water
Casting contact cooling water
1
A
A
A
A
1
A
*
1
2
i
*
12
1
*
A
*
*
I
4
A
1
A
1
1
A
A
A
A
A
/ "
1
A
A
1
A
A
A
A
A
2
/ */ / / / / /
A
A
A
A
A
A
A
A
A
A
A
A
A
1
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
0
14
1
0
0
0
1
0
0
0
0
2
5
0
0
0
0
0
1
0
0
0
t
1
0
0
0
1
2
0
5
0
460
-------
Table V-l (Continued)
NUMBER OF SAMPLES PER WASTE STREAM, BY SUBGATEGORY
Wa^te SL red m
Pobt-casting bilteL wa.-.hwater
Stationary and diret t chill i,a.-.i ing contac t t ool ing
water
Semi- c on t inuous and eont inuous cast ing con L act
cool ing water
Casting vacuum melting steam eondensate
Cast ing we t air pollut ion control b lowdown
Post-casting washwater
So In t ion heat treatment cont'/
3
1 9
1 £•
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A
X
A
A
A
A
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/
0
0
0
1
1
0
0
2
14
53
1
2
0
4
9
8
0
11
20
1
2
14
0
0
0
0
1
1
0
0
2
0
1
461
-------
Table V-l (Continued)
NUMBER OF SAMPLES PER WASTE STREAM, BY SUBCATEGORY
WdbLe Stream
Sizing »penL lubricants
Steam treatment wet air pollution cont rol blowdown
Oil-resin impregnation wastewater
Miscellaneous nondescript wastewater
Wet air pollution control blowdown
/
*
*
3
/
/
/
/ *
-A
3
*
/
/
/
0
3
0
0
0
3
*This waste stream was reported in dcp responses for plants in this subcategory, but no raw wastewater samples
were analyzed.
**Number of samples of this waste stream analyzed.
462
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Table V-3
NONTOXIC POLLUTANTS
Conventional
total suspended solids (TSS)
oil and grease
PH
Nonconventional
acidity
alkalinity
aluminum
ammonia nitrogen
barium
boron
calcium
chemical oxygen demand (COD)
chloride
cobalt
fliaoride
iron
magnesium
manganese
molybdenum
phenolics
phosphate
sodium
sulfate
tin
titanium
total dissolved solids (TDS)
total organic carbon (TOG)
total solids (TS)
vanadium
yttrium
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