±;PA 440/1-74/049
jroup II
Development Document for
Proposed Effluent Limitations Guidelines
and New Source Performance Standards
for the
PAVING AND ROOFING MATERIALS
(TARS AND ASPHALT)
Point Source Category
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
DECEMBER 1974
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DEVELOPMENT DOCUMENT
for
PROPOSED EFFLUENT LIMITATIONS GUIDELINES
and
NEW SOURCE PERFORMANCE STANDARDS
for
PAVING AND ROOFING MATERIALS
(TARS AND ASPHALT)
POINT SOURCE CATEGORY
Russell E. Train
Administrator
James L. Agee
Assistant Administrator for Water
and Hazardous Materials
Mr. A.D. Sidio
Director
National Field Investigations Center
Cincinnati, Ohio
Allen Cywin
Director, Effluent Guidelines Division
John Nardella
Project Officer
December, 1974
Effluent Guidelines Division
Office of Water and Hazardous Materials
U.S. Environmental Protection Agency
Washington, D.C. 20460
.
230 3. Dearb- -, -V ' ^~d'~')
, IL -***' ^ 16?0
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ABSTRACT
This document presents the findings of an in-house study of
the asphalt paving and roofing materials industry. It was
completed by the EPA, National Field Investigations Center -
Cincinnati, for the purpose of developing effluent
limitations guidelines and Federal standards of performance
for the industry, to implement Sections 304 and 306 of the
Federal Water Pollution Control Act, as amended.
Effluent limitations guidelines contained herein set forth
the degree of effluent reduction attainable through the
application of the best practicable control technology
currently available and the degree of effluent reduction
attainable through the application of the best available
technology economically achievable which must be achieved by
existing point sources by July 1, 1977, and July 1, 1983,
respectively. The standards of performance for new sources
contained herein set forth the degree of effluent reduction
which is achievable through the application of the best
available demonstrated control technology, processes,
operating methods, or other alternatives.
Supportive data and rationale for development of the
proposed effluent limitations guidelines and standards of
performance are contained in this report.
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Contents
Section Page
I. Conclusions 1
II. Recommendations 3
III.Introduction 7
Purpose and Authority 7
Summary of Methods Used for Development of the 8
Effluent Limitations Guidelines and Standards
of Performance
General Description of the Industry 9
IV. Industrial Categorization 33
Categorization 33
Rationale for Selection of Subcategories 33
V. Waste Characterization 37
General Use 37
Specific Uses 37
VI. Pollutant Parameters 41
Selected Parameters 41
Major Pollutants 41
VII.Control and Treatment Technology 51
Summary 51
Control Measures by Subcategory 53
Treatment Technology 54
VIII.Cost, Energy and Non-Water Quality Aspect 57
Introduction 57
Cost Information 57
Costs by Subcategory 59
IX. Best Practicable Control Technology 67
Currently Available
Pretreatment Standards for Existing Sources 71
X. Best Available Technology Economically Achievable 73
Introduction 73
Effluent Reduction Attainable Through 74
the Application of Best Available
Technology Economically Achievable
XI. New Source Performance Standards 77
Standards of Performance for New Sources 77
Pretreatment Standards for New Sources 78
XII.Acknowledgments 81
XIII.References 83
XIV.Glossary 85
XV. Conversion Table 91
111
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Tables
Status of Wastewater Treatment and Disposal 2
Practices at Plants in the Paving and Roofing
Materials (Tars and Asphalt) Category (1974)
2. Effluent Limitations for Asphalt Emulsion 3
Plants
3. Effluent Limitations for Asphalt Concrete 4
Plants
4. Effluent Limitations for Asphalt Roofing 4
Plants
5. Effluent Limitations for Linoleum and Printed 5
Asphalt Felt Plants
6. Gross Sales By Subcategories Covered in These 11
Guidelines (1971)
7. Data Base for Manufacturing Facilities in the 12
Asphalt Paving and Roofing Industry
8. Typical Prepared Roofings 19
9. Roofing Shipments in the United States 20
10. Weights and Uses of Typical Felts 21
11. Treatment Costs in Dollars for Asphalt 60
Emulsion Plants
12. Treatment Costs in Dollars for Asphalt Concrete 62
Plants
13. Treatment Costs in Dollars for Asphalt 63
Roofing Plants
Earthen Stilling Basin Used
14. Treatment Costs in Dollars for Asphalt Roofing 64
Plants Settling Tank Used
15. Treatment Costs in Dollars for Linoleum 65
and Asphalt Felts Plants
IV
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Figures
Figure
1 Half section view of asphalt oxidizing tower 14
2 Controlled hot-mix asphalt concrete plant 16
3 Schematic drawing of line for manufacturing 24
asphalt shingles, mineral-surfaced rolls,
and smooth rolls.
4 Schematic drawing of line for manufacturing 30
linoleum
v
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SECTION I
CONCLUSIONS
This report proposes effluent guidelines and standards of
performance, for the industries listed under the following
Standard Industrial Classification (SIC) code categories:
SIC 2951 - Paving mixtures and blocks
SIC 2952 - Asphalt felts and coatings
SIC 3996 - Linoleum, asphalted-felt-base, and other hard
surface floor coverings not elsewhere classified
These categories were subcategorized into the following four
industrial facilities:
1. Asphalt emulsion plants that make blown asphalt for
use in either roofing or paving materials and also
produce asphalt emulsion.
2. Asphalt concrete plants that manufacture paving
materials, such as blacktop.
3. Asphalt roofing plants that produce asphalt felts,
shingles, and other products, such as asphalt
impregnated siding, expansion joints, tars and
pitch, and roofing cements.
4. Linoleum and printed asphalt felt plants that make
linoleum and printed asphalt felt floor coverings.
The major selection criteria for the four subcategories are
the type of product manufactured and the quantity of waste
generated. Other factors, such as age, size, and location
of plants do not require further subcategories. The main
pollutants in these wastes are non-filterable suspended
solids and freon extractible oils. The suspended solids can
be removed by using sedimentation, filtration, or air
flotation methods, while gravity separators, air flotation,
or deep bed filters can remove the oils.
A large number of plants in all four subcategories are
currently achieving the 1977 requirement for application of
best practicable technology currently available and the 1983
requirement for the application of best available technology
economically achievable. The number of plants doing so in
each subcategory are listed in Table 1.
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TABLE 1
Status of
Wastewater Treatment and Disposal Practices
At Plants in the
Paving and Roofing Materials (Tars and Asphalt) Category
(1974)
Approximate Number of Plants
Approx. Meeting Meeting Using munic- With little
No. of 1977 1983 ipal sewer or no
Subcatggory plants standards* standards* system treatment
Asphalt
emulsion
Asphalt
concrete
Asphalt
roofing
50
18+
3,600** 3,100+
225
46+
3,lOOf
25t
25
None
known
158
Linoleum 20++
and printed
felt
500
21
20
* See Section III.
+ Industry - provided estimate
* Included in total for 1977 standards.
** An additional 1,200 plants do not use water in the processing,
++ Only one plant is known to produce linoleum.
New source performance standards are proposed which reflect
internal improvements which can be achieved through
effective design and layout of plant operation. The
resulting effluent may be recycled or discharged.
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SECTION II
RECOMMENDATIONS
The following effluent limitations guidelines and standards
of performance are recommended for the asphalt emulsion,
asphalt concrete, asphalt roofing, linoleum, and printed
asphalt felt industries (Tables 2 through 5).
TABLE 2
Effluent Limitations For
Asphalt Emulsion Plants*
Technology
or Standard
BPCTCA+
BATEA*
NSPSf
BPCTCA
BATEA
NSPS
Suspended Solids
30-day average
kg/cu m lb/1000 gal
Maximum daily
kg/cu m lb/1000
Not Regulated
0.015 0.125
0.015 0.125
Not Regulated
0.023 0.188
0.023 0.188
Oils and Grease
0.015
0.010
0.010
0.125
0.083
0.083
0.020
0.015
0.015
C.167
0.125
0.125
Note: pH within the range 6.0 to 9.0
*Limits are based on the containment of runoff resulting from
7.62 cm (3 in) of rain falling on a 4-hectare (10-acre) plant
production site during a 2U-hour period. The resulting volume
of water is 3,028 cu m/day (0.8 mgd). The limits are also based
on weight of pollutant per volume of runoff water.
+Best practicable control technology currently available
#Best available technology economically achievable
**New source performance standards
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TABLE 3
Effluent Limitations For
Asphalt Concrete Plants
Technology
or Standard
Suspended Solids
30-dav average
kg/kkg lb/1000 Ib
BPCTCA*
BATEA+
NSPSt
No Discharge
No Discharge
No Discharge
Maximum daily
kg/kkg lb/1000 Ib
No Discharge
No Discharge
No Discharge
*Best practicable control technology currently available
+Best available technology economically achievable
fNew source performance standards
TABLE 4
Effluent Limitations For
Asphalt Roofing Plants*
Technology
30-day average
kg/kkg lb/1000 Ib
Suspended Solids
Maximum daily
kg/kkg lb/1000 Ib
BPCTCA+
BATEA*
NSPS**
0.038
0.010
0.019
0.038
0.019
0.019
0.056
0.028
0.028
0.056
0.028
0.028
NOTE: pH within the range 6.0 to 9.0
*Limits are based on weight of pollutant per weight of product
produced. An average water discharge of 569 cu in/day (0.15 mgd)
and a daily production level of 454 kkg (500 tons) were used
in the unit determination.
+Best practicable control technology currently available
tBest available technology economically achievable.
**New source performance standards
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TABLE 5
Effluent Limitations For
Linoleum and Printed Asphalt Felt Plants*
Technology
or Standard
Suspended Solids
30-day average
kg/kkg lb/1000 Ib
Maximum daily
kg/kkg lb/1000
Ib
BPCTCA+
BATEA*
NSPS**
0.025 0.025
0.013 0.013
0.013 0.013
0.038
0.019
0.019
0.038
0.019
0.019
NOTE:
pH within the range 6.0 to 9.0
*Limits are based on weight of pollutant per weight of product
produced. An average water discharge of 23 cu in/day (0.006 mgd)
and a daily production level of 27 kkg (30 tons) were used in the
limit determination.
+Best practicable control technology currently available
#Best available technology economically achievable
**New source performance standards
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SECTION III
INTRODUCTION
Purpose and Authority
Section 301 (b) of the Federal Water Pollution Control Act,
as amended requires the achievement by not later than July
1, 1977, of effluent limitations for point sources, other
than publicly owned treatment works, which are based on the
application of the best practicable control technology
currently available as defined by the Administrator pursuant
to Section 304 (b) of the Act. Section 301 (b) also
requires the achievement by not later than July 1, 1983, of
effluent limitations for point sources, other than publicly
owned treatment works, which are based on the application of
the best available technology economically achievable which
will result in reasonable further progress toward the
national goal of eliminating the discharge of all
pollutants, as determined in accordance with regulations
issued by the Administrator pursuant to Section 304 (b) of
the Act. Section 306 of the Act requires the achievement by
new sources of a Federal standard of performance providing
for the control of the discharge of pollutants which
reflects the greatest degree of effluent reduction which the
Administrator determines to be achievable through the
application of the best available demonstrated control
technology, processes, operating methods, or other
alternatives, including, where practicable, a standard
permitting no discharge of pollutants.
Section 304 (b) of the Act requires the Administrator to
publish regulations providing guidelines for effluent
limitations setting forth the degree of effluent reduction
attainable through the application of the best practicable
control technology currently available and the degree of
effluent reduction attainable through the application of the
best available control measures and practices achievable
including treatment techniques, process and procedure
innovations, operation methods and other alternatives. The
recommendations proposed herein set forth effluent
limitations guidelines pursuant to Section 304 (b) of the
Act for the asphalt emulsion, asphalt concrete, asphalt
roofing, linoleum, and printed asphalt felt manufacturing
point sources.
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Summary of Methods Used for Development of the Effluent
~ Limitations Guidelines and Standards of Performance
The effluent limitations guidelines and standards of
performance proposed herein were developed in the following
manner. The point source category was first studied for the
purpose of determining whether separate limitations and
standards are appropriate for different segments within the
category. This analysis included a determination of whether
differences in raw material used, product produced,
manufacturing process employed, age of plant, size of plant,
wastewater constituents, and other factors require
development of separate limitations and standards for
different segments of the point source category. The raw
waste characteristics for each such segment were then
identified. This included an analysis of: (1) the source
flow and volume of water used in the process employed and
the sources of waste and wastewaters in the plant; and (2)
the constituents (including thermal) of all wastewaters,
including toxic constituents and other constituents which
result in taste, odor, and color in the water or aquatic
organisms. The constituents of the wastewaters which should
be subject to effluent limitations guidelines and standards
of performance were identified.
The full range of control and treatment technologies
existing within each segment was identified. This included
an identification of each distinct control and treatment
technology, including both in-plant and end-of-process
technologies, which are existent or capable of being
designed for each segment. It also included an
identification of, in terms of the amount of constituents
(including thermal) and the chemical, physical, and
biological characteristics of pollutants, the effluent level
resulting from the application of each of the treatment and
control technologies. The problems, limitations, and
reliability of each treatment and control technology and the
required implementation time were also identified. In
addition, the non-water quality environmental impact, such
as the effects of the application of such technologies upon
other pollution problems, including air, solid waste, noise,
and radiation was also identified. The energy requirements
of each control and treatment technology were identified as
well as the cost of the application of such technologies.
The information, as outlined above, was then evaluated in
order to determine what levels of technology constituted the
"best practicable control technology currently available,"
the "best available technology economically achievable," and
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the "best available demonstrated control technology,
processes, operating methods, or other alternatives." In
identifying such technologies, various factors were
considered. These included the total cost of application of
technology in relation to the effluent reduction benefits to
be achieved from such application, the age of equipment and
facilities involved, the process employed, the engineering
aspects of the application of various types of control
techniques, process changes, non-water quality environmental
impact (including energy requirements) and other factors.
The data on which the above analysis was performed were
derived from EPA permit applications, EPA sampling and
inspections, and industry submissions.
General Description of the,Industry
The SIC codes (categories) discussed in these guidelines
are:
1. 2951 - Paving mixtures and blocks
2. 2952 - Asphalt felts and coatings
3. 3996 - Linoleum, asphalted-felt-base,
hard-surface floor coverings, not elsewhere
classified.
These categories were then divided into the following
subcategories:
1. Asphalt emulsion plants engaged in the production
of blown asphalt for use in roofing or paving materials.
2. Asphalt concrete plants engaged in the production
of paving materials, such as black top
3. Asphalt roofing plants engaged in the production of
asphalt felts, shingles, and other products, such as
impregnated asphalt siding, expansion joints, canal liners,
roofing cements, tars and pitches, and tar paper.
4. Linoleum and printed asphalt felt plants engaged in
the production of linoleum floor coverings and printed
asphalt felt floor coverings.
The waste waters generated by the Asphalt Paving and Roofing
manufacturing industry has received almost no attention in
engineering and pollution control literature. Very few
plants have any information more extensive than the results
of analyses of one or a few grab samples of the final
effluent. The data used in this document were, therefore,
necessarily very limited and were derived from a small
number of sources. Some of these were published literature
on manufacturing processes, EPA technical publications on
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the industry, and consultations with qualified personnel.
Most of the information on wastewater volumes and
characteristics, however, was obtained from: 1) Refuse Act
Permit Program (RAPP) applications; 2) an on-site sampling
program; 3) telephone conversations with people in the
industry and from district and city wastewater treatment
personnel.
Approximately 5,100 plants with gross sales of $1.8 billion
in 1971 manufacture products which are covered by this
document. These plants are located throughout the country,
but are generally near large metropolitan areas. The
numerical breakdown of the plants in each subcategory and
the 1971 gross sales for each are shown in Table 6.
RAPP applications were available and used to study 43 of
these facilities. The applications provided data on the
characteristics of intake and effluent waters, water usage,
wastewater treatment provided, daily production, and raw
materials used.
Because the process used by each subcategory and the
resulting wastewater characteristics are similar in nature,
visiting one or two plants and making several telephone
surveys were considered sufficient to verify the data
collected on wastewater characteristics and treatment
techniques.
The number of known manufacturing facilities in each
subcategory and the number of plants visited, sampled, and
contacted by telephone are presented in Table 7. It also
lists the number of plants that discharge into city sewer
systems and the number of RAPP applications examined.
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TABLE 6
Gross Sales By Subcategories
Covered In These Guidelines *
(1971)
Number of Gross Sales
SIC Subcategory Plants _(Million_of _Dollars]L
2951
2951
2952
Asphalt emulsion plants
Asphalt concrete plants
Asphalt roofing plants
50
a, 800+
226
747. 5#
825.9
1. Asphalt and tar saturated
felts and boards for non-
building use. 19.8
2. Roofing asphalts, pitch,
coatings, and cements. 153.7
3. Asphalt and tar roofing
and siding products. 638.5
4. Asphalt felts and coatings. 13.9
3996 Linoleum and printed asphalt
felt plants 20 245.6
1. Linoleum, asphalt felt base,
and supporting plastic floor
covering. 241.6
2. Hard surface floor covering __ 4^0 _
TOTAL 5,096 1,819.0
From Reference 3
This figure is comprised of approximately 900 asphalt concrete
plants that are classed under SIC Code 2951, and approximately
3,900 asphalt concrete plants that are classed under SIC Code 1611,
Total gross sales for the combined SIC Code Group 2951 minus the
sales from the plants classed under SIC Code 1611.
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TABLE 7
Data Base
for
Manufacturing Facilities
in the
Asphalt Paving and Roofing Industry
Subcategory
No. of Plants RAPP Plants Surveyed Discharge
Reported Applications by visited to
Phone or sampled city._sy_stem
Asphalt Emulsion 50
Asphalt Concrete 4,880
Asphalt Roofing 226
Linoleum and
Printed Felts 20
4
11
25
5
8
25
2 25
1 None Known
3 158
2 2C
TOTAL 5,176
43
45
8
2C3
The asphalt concrete and asphalt roofing plants are the two
largest subcategories in terms of numbers of plants and
gross sales. The asphalt emulsion and concrete plants gross
sales for 1971 are given as a combined sum for the entire
2951 subcategory. The leading product of the 2952
subcategory is the impregnated shingle.
Although tar products are listed under this subcategory,
their use is slowly being phased out. Some products that
are labeled tar paper are, in fact, asphalt saturated felts.
SIC code group 3996 has been divided into linoleum, asphalt-
felt base and hard-surface floor coverings. The latter
accounts for such a small percentage of total sales that it
will not be discussed further.
True linoleum is known to be produced by only one plant in
the United States, while approximately 20 plants produce the
less-expensive grade of printed asphalt felt floor covering-
Printed felts are often sold as linoleums, but in reality
they are not. Both linoleum and printed asphalt felt floor
12
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coverings are being phased out and being replaced with vinyl
floor coverings, which are easier to install and whose
wearing surface lasts longer. A more detailed description
at each subcategory follows:
Asphalt Emulsion Plants (SIC 2951)
More than 90% of all asphalt and asphalt products is
manufactured from the residues generated when crude
petroleum is distillated. The residual, called "resid" or
"flux" is barged or trucked to the manufacturers* plants and
stored in heated tanks until ready for processing. The
resid which is heated to approximately 232°C (450°F) is
pumped to the top of a vertical tower. The vertical tower
known as an oxidizing tower, oxidizes the heated resid by
forcing hot air through it (Figure 1). The rate at which
the resid is pumped into the oxidizing tower varies, but the
average flow is about 0.76 cu m/min (200 gpm). The hot air
drives off the high volatiles and modifies some of the
resid's physical properties — melting point, hardness,
penetration, and ductility. The longer the resid is
oxidized, the more these physical properties are modified.
Asphalt used in paving operations and paving emulsion are
oxidized continuously in a flow-through tower, while asphalt
used in roofing applications is batch processed and is
allowed to oxidize for a longer period of time.
Various methods can be used to control air emissions from
the tower. The exhaust gases may be passed through a series
of knockout drums before being burned or through a series of
wet scrubbers. Knockout drums cause the heavier particles
in the air stream to fall out and the remaining gases are
burned to remove any volatiles still present. Wet scrubbers
trap the particles in water.
Paving asphalt is stored in heated tanks as soon as it
leaves the oxidizing tower, while roofing asphalt is
packaged immediately or is emulsified with a water and
chemical mixture, then packaged. The containers are made of
paper board or metal.
Emulsions that can be used in roofing or paving mixtures are
emulsified in colloidal mills. Asphalt enters the mill at a
temperature of about 177°C (350°F) and is emulsified with a
water and chemical mixture which enters at a temperature of
66°C (150°F). The resulting emulsion temperature is between
99-110°C (210-230°F). The emulsion is cooled in a shell and
tube heat exchanger and is then packaged in 19 or 208 1 (5
or 55 gal) containers. By varying the water and chemical
mixture, different grades of emulsions can be produced.
13
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FIGURE 1
HALF SECTION VIEW
OF
ASPHALT OXIDIZING TOWER
ASPHALT FLUX
EXHAUST AIR
14
OXIDIZED ASPHALT
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Plants in this subcategory range in size from 1,814 to 9,072
kkg/day (2,000 to 10,000 tons/day). The average size plant
used in developing these guidelines produced 5,443 kkg/day
(6,000 tons/day). The primary use of water in this
subcategory is to control the temperature of the oxidizing
tower, and this is done by two methods. First, water
circulates through jackets around the outside of the tower
and never comes in contact with the asphalt. The flow
varies between 190 and 3,790 cu m/day (0.05 to 1.0 mgd).
Second, water is injected into the oxidizing asphalt at a
carefully monitored rate so as not to disrupt the oxidizing
process yet stay within the temperature limits. The rate of
water injection is about 11.4 1/min (3 gpm). As the water
is injected, it is vaporized by the heat of the tower. The
heat needed to do this is therefore expended and results in
a cooler tower temperature.
Only the first method results in a wastewater discharge, but
it is relatively free of contaminants because the water is
essentially a noncontact type. The only source of
contaminated water is from the wet collection of exhaust
fumes or from runoff caused by precipitation. This water is
usually sewered with the cooling water.
Asphalt Concrete Plants fSIC 2951)
Asphaltic concrete is made by combining sand or gravel with
asphalt. Sand or gravel is heated and dried in a rotary
drier and is then transported to a mixing hopper where a
weighed amount of asphalt is mixed in (Figure 2).
Until a few years ago, the asphalt concrete industry was
generally recognized as a major source of particulate
emissions. Poorly controlled asphalt concrete plants were
known to release 5 to 7.5 kg/kkg (10 to 15 Ib/ton) of
particulates to the atmosphere. Considering an average size
plant produces approximately 181 kkg/hr (200 ton/hr) of
asphalt concrete an installation equipped with only dry
centrifugal dust collectors, would emit 907 to 1,361 kg
(2,000 to 3,000 Ib) of particulate each hour of operation.
To reduce emissions, fabric filters or medium-energy venturi
scrubbers, normally preceded by a cyclone or multiple
cyclones, can be used to collect dust from the drier. Other
systems of collecting the particulate matter can be used,
but the above methods are the two most widely used in this
subcategory. The wet type collection system is the most
commonly used system. The amount of water needed for a wet
collection system may range from 0.2 to 0.8 cu m/min (50 to
200 gpm). The resultant slurry is usually discharged to an
15
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EMISSIONS
HOT SCREENS
STACK
MINERAL FILLER
FINES STORAGE
PRIMARY DUST
COLLECTOR
SEALED
OVERFLOW
BIN
ASPHALT
STORAGE
TANK
FIGURE 2: CONTROLLED HOT-MIX ASPHALT CONCRETE PLANT.
(FROM REFERENCE 1)
16
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open pit where the particulates settle out; the clear water
is then recycled.
Asphalt Roofing Plants (SIC 2952)
Asphalt saturated felt products are used as a water barrier,
primarily in the siding and roofing materials field.
Roofing felts and impregnated roofing felts (shingles) rank
ahead of roofing asphalts and tars, tar papers, canal
liners, expansion joints, roofing cements, and other
asphalt-related items produced by plants in this
subcategory. Only the roofing felts and impregnated roofing
felts will be discussed.
Asphalt roofings are classified as "prepared" or "built-up",
depending on the method of construction and application.
Roofings that are factory "prepared" and are applied to a
roof without any major constituent having to be added are
called prepared, composition, or ready roofings; the first
term is generally preferred by the industry. The major
components of built-up roofings are assembled just prior to
being applied. Since this is done on-site and not at a
factory, this type of roofing will not be discussed.
Prepared roofings are composed of a structural felt
framework, a relatively soft asphalt saturant for the felt,
and a relatively hard or viscous asphalt coating applied to
the surfaces of the felt. Minerals may be embedded in the
final coating.
The roofing may be in the form of small individual or
multiple-cut units in large flat sheets or in long strips or
rolls. Regardless of their form, they are designed to be
held on by nails or by nails and a small amount of cement.
They consist almost entirely of asphalts of petroleum
origin. Some experimental prepared roofings have been
produced employing coal tar saturants and coatings, but
these have not been manufactured commercially. When
marketed in the form of small cut units they are called
shingles, and when supplied in roll form they are designated
roll roofings. Prepared roofings sold in the form of large
flat sheets are usually of multiple ply construction and are
termed plied or laminated roofings.
Roll roofings may be dusted on both sides with fine mineral
matter, such as talc, mica, or fine sand, to prevent
sticking in the rolls, or the side intended for exposure to
the weather may have the fine mineral replaced by relatively
coarse mineral granules. The first type is described as
smooth-roll roofing, the second as granule-surfaced roll
17
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roofing. Asphalt shingles are always granule surfaced.
(Table 8)
Several terms are used to describe the various types of
prepared roofing. Both smooth and granule-surfaced roll
roofings are described as composition or ready roofings.
Smooth roll roofings are also sometimes referred to as
rubber roofings. Granule-surfaced roofing is also known as
mineral surfaced roofing, slate surface roofing, or grit
roll roofing. Asphalt shingles are called slate-surfaced
shingles, composition shingles, and frequently as asbestos
shingles, even though they usually contain no asbestos
fibers.
As first marketed, prepared roofings made with asphalt
impregnants and coatings were not granule-surfaced.
Granule-surfaced roll roofings first appeared in 1897, and
granule-surfaced (slate) shingles were introduced in 1901.
Asphalt shingles did not come into general use until about
1911. By 1971 asphalt-prepared roofings accounted for
approximately 90% of all the roofing materials used in the
United States. Department of Commerce figures, which show
the shipment of asphalt roofing material sold, are
summarized in Table 9. The estimated dollar value of the
asphalt roofing sold in 1971 was approximately $826 million.
(Table 6)
Materials Used
Asphalt roofings are currently made of three types of
roofing felt or fabric: organic, asbestos, or glass fibers.
Felts are formed on a machine similar to that used to
manufacture paper. Typical weights and uses are presented
in Table 10.
18
-------
TABLE 8
Typical Prepared Roofings*
Parameter
Weight, lb/100 sq ft
Felt base, % by wt
Saturant for felt, % by wt
Coating (filled) , % by wt
Surfacing, % by wt
Character of felt
Weight, lb/480 sq ft
Thickness, in.
Composition:
Rag fiber, %
Chemical wood pulp, %
Mechanical wood pulp.
Character of saturant
Softening point (R&B) ,°F
Penetration at 77 °F
Character of coating
Filler (limestone) , % by
Softening point (R&B) ,
unfilled, °F
Softening point (R£B) ,
filled, °F
Smooth Roll
Roofing
48.4
14.0
19.6
59.8
6.6
30
0.034
0
45
X 55
110
150
wt 50
220
230
Penetration at 77°F, unfilled 18
Character of surfacing
Cumulative retained
10-mesh sieve, %
14-mesh sieve, %
35-mesh sieve, %
100-mesh sieve, %
200-mesh sieve, %
* From Reference 5
+ Not measurable
0
0
0
40
60
Granule-surfaced Standard
Roll Roofing
90
12.5
19.9
23.9
43.7
50
0.055
0
45
55
110
150
50
220
230
18
1
35
98
*
•f
Shingle
98
11.6
19.9
34.4
34.2
55
0.060
0
45
55
130
70
53
220
230
18
1
35
98
+
+
19
-------
TABLE 9
Roofing Shipments in the United States*
year
1972
1971
1970
1969
1968
1967
1966
1965
Asphalt Roofing
100 sq ft
97,696,321
93,246,194
83,179,391
84,430,028
78,044,744
76,500,410
69,393,339
72,337,669
Asphalt Siding
100 scr ft
136,102
185,668
259,942
363,627
417,648
467,597
554,368
627,564
Insulated Siding
100 sq ft
366,612
375,096
333,844
346,464
410,621
444,587
539,445
590,120
Saturated Felt
Tons
895,062
915,556
848,262
919,687
874,998
876,019
879,571
979,632
* From References 2 and 3
20
-------
TABLE 10
Weights and Uses of Typical Felts*
Fiber type
Saturated
Average dry weight weight
fib/100 sq ft) fib/100 sq ft)
Saturated felt use
Organic
Asbestos
Glass
5.6
6.3
10.4
11.5
12.5
9.0
12.0
13-14+# Built-up roofing,
shingle underlayment,
"building paper"
18-20 Lightweight roll roofing
26-27** built-up and roll roofing
30-31++ shingles, standard and
heavyweight
32.5-34++ heavyweight shingles***
13-15ff built-up roofing
18-20f# roll roofing, smooth
and granule surfaced
4-6 built-up roofing,
granule-surfaced shingles
8-10 built-up rooding, roll
roofing, shingles
From Reference 5
Must be at least 2.4 times the dry weight of dry felt.
Saturated with asphalt or coal tar; all other products
shown are asphalt saturated.
Must be at least 2.5 times the dry weight.
Must be at least 2.6 times the dry weight.
Must be at least 1.4 times the dry weight.
Asphalt
The asphalts used in the manufacture of prepared roofing
consist almost entirely of petroleum origin. The asphalts
used in impregnating the felts, known in the industry as
"saturants," are usually of a semi-solid consistency. The
saturants employed for shingles are generally harder, are
more viscous, and have a higher softening point, 52-82°c
(125-180°F), than those employed in manufacturing roll
roofings, 38-52°C (100-125 °F).
-------
Coating asphalts/ and those applied to the surface of the
saturated felts in the manufacture of prepared roofings must
be fluid enough to spread uniformly over the saturated felt,
adhere well to the felt, and hold mineral granules. On the
other hand, the coating must be stable enough not to flow
when the product is installed on the roof, and it must
continue to hold the granules in place. The viscosity of
the asphalt coating at roof temperature is estimated to be
on the order of 7 x 10(8) poises. Such coatings have
softening points in the range of 93-121° C (200 - 250°F).
Coatings consist of 100% asphalt or contain mineral fillers
in amounts as high as 50-60% by weight of the mixture. Most
manufacturers add mineral fillers to increase the coating's
weatherability. The fillers are usually of 100 mesh or
finer and are ground from such weather-resistant minerals as
slate, limestone, silica, trap rock, diatomaceous earth,
talc, and mica.
The asphalts used as cements in the manufacture of plied
roofings have softening points between 66-121°C (150-250°F),
and are filled or unfilled depending on the type of roofing
involved and the manufacturer's preference.
Surfacing Materials
Smooth roll roofings, the backs of asphalt shingles, and
granular-surfaced roll roofings are usually dusted with
pulverized minerals to prevent them from sticking when
packaged; talc and mica are the most widely used.
Coarse mineral granules have been employed on the weather
face of prepared roofings since 1901, and slate was the
first material employed for this purpose. Granular facings
greatly improve the resistance to the weather, and they are
also used to vary the color and texture of the roofings.
Although such natural minerals as slate still find extensive
use today, the greater percentage of granular surfacings is
synthetically prepared to provide a range of color and
brilliance unobtainable in natural minerals.
The colored granules that have proved most satisfactory for
use on prepared roofings are:
1. Natural granules, such as various colored slates
and gray or green stones.
2. Natural minerals fired at high temperatures, such
as shale or clay to which a metallic pigment is
sometimes added to provide color. The color may
extend throughout the body of the granule or be on
the surface.
22
-------
3. Ceramic granules are manufactured from a crushed
base rock, such as trap rock, basalt, or other
opaque, weather-resistant rock. They are coated
with a mixture of pigment and inorganic bonding
material and subsequently fired to insolubilize
pigment and binder onto the surface of the
granules.
4. Slag granules which may be either blast furnace
slag or wet bottom furnace slag. The blast furnace
granules are usually used only in headlap
surfacing, whereas the wet bottom slag granules are
used for exposed area surfacing and headlap.
Any of these four types may be further treated with
materials to make them lipophilic and improve their adhesion
to asphalt.
Manufacturing Process
Asphalt roofings and shingles are manufactured on high-
speed, continuously operating machines; some types are
produced at a rate as high as 152 m (500 ft) per minute.
The process consists of saturating the felt, coating the
surfaces with asphalt, surfacing with asphalt, surfacing
with pulverized or granular minerals, cooling, cutting, and
packaging (Figure 3).
Dry felt and loopers
A roll of dry felt is installed on the felt reel and is
unwound onto the "dry looper," which acts as a reservoir
that can be drawn upon by the machine as circumstances
demand. This eliminates stoppages, such as when a new roll
must be put on the felt reel or when an imperfection in the
felt must be cut out.
Saturation of felt
After passing through the dry looper, the felt is subjected
to a hot saturating process, usually at a temperature of
between 232-260°C (450-500<>F) . The asphalt saturant fills
the voids in the felt, helps bind the felt fibers, and
"primes" the felt to assure good coating adhesion and
improve the weather resistance of the felt without damaging
the weather-resistant coating.
Wet looper
At this point, an excess of saturant usually remains on the
surface of the sheet. It is therefore held for a time on a
23
-------
TO CONTROL
EQUIPMENT
I
TANK
TRUCK
BAGHOUSEj*
MIXER
ASPHALT SATURATOR
WATER
FIGURES: SCHEMATIC DRAWING OF LINE FOR MANUFACTURING
ASPHALT SHINGLES, MINERAL - SURFACED ROLLS, AND
SMOOTH ROLLS. (FROM REFERENCE 5)
SHINGLE
BUNDLES
TO STORAGE
SHINGLE SHINGLE
CUTTER STACKER
-------
wet looper so that the natural shrinking of the asphalt that
occurs upon cooling will cause the excess to be drawn into
the felt, resulting in a very high degree of saturation.
Coater
The sheet is then carried to the coater where asphalt is
applied to both the top and bottom surfaces, usually at a
temperature of 177-204°C (350-400°F). The quantity applied
is regulated by rolls which can be brought together to
reduce the amount or separated to increase it, and this
determines the product weight. Many machines are equipped
with automatic scales which weigh the sheets in the process
of manufacture and warn the operator when the material is
running over or under weight specifications.
Mineral Surfacing Application
When smooth-roll roofing is being made, talc or mica or
another "parting" agent is applied to the two sides of the
sheet and pressed into the coating by rolls. When mineral
surfaced products are being prepared, colored granules are
added from a hopper and spread thickly on one side, and
backing material is applied on the other side. The sheet is
then run through a series of cooling and press rolls to
properly embed the granules. The temperature at the rolls
is usually 107-135<>C (225-275°F) . The granules must be
screened within narrow limits to assure uniform appearance
and good adhesion.
Texture
At this point, some products are pressed by an embossing
roll which forms a pattern on the surface of the sheet.
Finish or cooling looper
The function of this looper is to cool the sheet so that it
can be cut and packed without being damaged. The
temperature at the start of the looper is usually 82-93°C
(180-200°F) and at the cutter it is usually about 38°C
(100°F) .
Water or air is used to cool the sheets. Air is used
only if the production rate is slow and enough time is
available.
The water system involves the use of contact sprays or mist
or non-contact cooling drums. These two methods can be used
separately or in conjunction with each other.
25
-------
The amount of water used depends on the production rate, the
ambient air temperature, and the type of system used. The
non-contact system is essentially a recycling system and the
amount of water discharged is less than 2% of the total
flow. The amount of water used in the spray system ranges
from 1.2 1/cu m (0.03 gal/sq ft) to 412 1/cu m (10.1 gal/sq
ft); the latter values are equivalent to about 379-948 cu
m/day (0.10-0.25 mgd) .
Shingle Cutter
Shingles are made by feeding the material from the finish
looper into a cutting machine, where the sheet passes
between a cutting cylinder and a pressure roll. The
cylinder cuts the sheets from the back or smooth side, and
they are then separated into units which accumulate in
stacks to be packaged.
Roll Roofing Winder
When roll roofing is being made, the sheet is drawn from the
finish looper to the winder where a mandrel measures the
length of the material as it turns. When a sufficient
amount has accumulated, it is cut off, removed from the
mandrel, and wrapped.
Linoleum and Printed Asphalt Felt Plants_jSIC 3996J
This subcategory is listed as SIC code group 3996, a
miscellaneous category. The industries that fall under it
produce floor coverings that are slowly being replaced by
the vinyl floor coverings covered under SIC code group 3292,
which also encompasses the makers of asphalt tile. The
plants covered under SIC code group 3996 are those that make
linoleum, printed asphalt felt, and supported plastic floor
coverings. The supported plastic floor coverings will not
be discussed because they represent such a small part of
this subcategory.
Linoleum has a relatively thick wearing surface that, extends
to a backing of burlap, cotton fabric, or felt. The wearing
surface consists of a binder or cement of blown (oxidized)
drying oils and resin that is filled with cork, wood flour,
mineral filler, or combinations of fillers and pigments.
Cork was once the principal filler, but its use has been
curtailed, because it cannot be employed in the bright
patterns now in demand.
Linoleums fall into four principal classes: plain colored,
marbled (jaspe), straight-line inlaid, and molded inlaid.
26
-------
The marble (jaspe) patterns are prepared by blending mixes
of two or more colors to obtain a mottled pattern.
Straight-line inlaid is characterized by geometric pieces of
several patterns arranged largely in straight lines. The
molded-type materials may have many colors arranged in
geometric patterns formed by rubbing granular colors through
stencils. This material may be embossed, and some patterns
simulate ceramic tile.
Printed felt base consists of a baked-enamel decorative
coating on an asphalt-saturated felt backing. Although
printed asphalt felts are not linoleum, some are sold under
that name.
Production of Linoleum
Oxidation of oils and preparation of cement
Linoleum cement is produced by bringing linseed oil or other
drying oils into contact with air. The problem of making a
satisfactory linoleum cement consists of more than producing
a rubber-like binder in which fillers and pigments can be
incorporated and calendered to a smooth sheet. The cement
must also possess heat reactivity, so it will harden when
stoved (a curing process).
Linseed oil is by far the most important base material used
in linoleum manufacture. Soybean (soya) oil is also used in
appreciable amounts, and its employment appears to be
increasing. Linseed oil consists principally of the
glyceride of saturated, oleic, linoleic, and linolenic
acids. The same esters occur in soybean oil, but differ in
that they contain a minor amount of linolenate esters. In
addition to the much higher content of the triunsaturated
linolenate esters, linseed oil contains a much larger
proportion of the total di- and triunsaturated esters than
soybean oil. This lower unsaturation in soybean oil is
reflected by a longer time for oxidation and stoving, but
the final product is very flexible and possesses excellent
color.
Before being oxidized, either of the oils used is often put
in storage tanks to settle out any solids. The clear oil is
then pumped off the top and into long-jacketed, cylindrical
kettles where it is agitated by a horizontal shaft and many
rotating arms.
The oil is then warmed to start oxidation, and air is blown
into the kettles. In some instances, the air is dried since
moisture retards oxidation. After the induction period, the
-------
oil evolves heat, and water is circulated to control the
temperature of the reaction — usually below 80°C (176°F).
Sometimes the temperature is allowed to rise to 90°C {194°F)
and is then decreased to 60°C (140°F). Oxidation takes
place more rapidly at higher temperatures, but the color of
the oil is better when lower temperatures are employed.
During most of the usual 24-hour oxidation period the oil is
fairly fluid, but during the last hours, the mix becomes
very viscous. In some cases, agitator speed is reduced when
viscosity increases. The process ends when the viscosity
has risen to the desired value or when the desired "linoxyn"
content is reached; "linoxyn11 is oxidized material which has
polymerized to an insoluble gel.
The blown oil is then poured out and allowed to cool in
thick slabs. It is often allowed to age before use, as
further hardening occurs. If resins are not incorporated
into the oil in the blowing operation, the blown oil is
fluxed with resins to form the cement.
Mixing and calendering
After the cement has been formed, linoleum mix is prepared
by blending fillers and pigments into the cement. The
composition of the mix often varies according to the type of
linoleum in which it is to be used. The composition also
varies, depending on whether it is to be used in a solid-
color, marble (jaspe), straight-line inlaid, or molded
inlaid material, or in a wall covering.
Cork has been an important filler in linoleum and in the
early years constituted the principal filler, if not the
only one. Today the trend has been toward cleaner, brighter
colors, and the trend has operated against the use of large
amounts of cork in linoleum, since its dark color will be
readily apparent. Cork is still used to some extent, but in
some patterns it is not used at all. If cork is used, it is
first reduced in size in a crusher and then ground in stone
mills. The cork is then sieved to size, and the coarse
material is reground.
Wood flour has largely supplanted cork as a low-density,
toothy filler. Mineral fillers are used with wood flour,
and although they are considerably heavier, they are much
less susceptible to moisture. Whiting (calcium carbonate)
is by far the most frequently used mineral filler. The wood
flours used are selected for their light color (usually pine
wood) and for their uniformity in texture and particle size
to ensure a smooth finish.
28
-------
In general, the same pigments used in paint production are
employed in linoleum manufacturing. Lithopone is regarded
as the standard pigment, but titanium dioxide is also
employed. Natural ochers have been largely supplanted by
synthetic iron oxides. Because colors are now popular,
there has been a trend toward using brighter and more stable
pigments.
The fillers and pigments are blended with the cement in a
series of operations in which the mix is continuously
reworked. Its flow properties must be carefully controlled
so that it will calender satisfactorily. Mixing formulas
for the various types of linoleum vary greatly and
pigmentation is changed for the various colors. A
representative formulation for linoleum is: 35-45% cement,
25-30% wood flour, 30-40% pigments and whiting, and 10%
cork, scrap linoleum, or clay.
The cement, fillers, and pigments are mixed in large steam-
jacketed vessels and are then passed through two or three
"germans" (machines equipped with a heated cylinder and a
screw feed). The mix next passes through rotating knives
and is extruded from the mixer in the form of small
sausages, which are then pressed between the rolls of a
calender to form a blanket. The calender, a wringer type
machine, is equipped with a hot top roller and a cold bottom
roller. As the blanket is being formed, it sticks to and
wraps itself around the hot roller. Another roller, faced
with many sharp points, is placed next to the hot roller and
picks small particles of the mix from the blanket. This
device is known as a "scratcher" and the resulting
granulated product is termed "scratch." The scratch, usually
particles about 1.6 mm (1/16 in) to 4.7 mm (3/16 in) in
diameter, is then either stored or conveyed to another
calender for processing. (Figure 4)
For plain colors, a single scratched mix is supplied. One
roll is heated; the felt or other backing material is fed
onto the other roll, which is cold. The heat and pressure
of the rolls consolidate the mix into a smooth sheet and key
the mix to the backing material. The calendered sheet
passes from the calender into the stoves for curing.
The process is similar for marble (jaspe), except that two
or more scratched mixes of different colors are supplied to
the calender, which smears the two colors into a
longitudinal striation. For certain marble effects one of
the colors may be supplied to the calender in pellets of
various sizes before the backing is applied. The backing is
29
-------
FIGURE 4
SCHEMATIC DRAWING
OF LINE
FOR
MANUFACTURING LINOLEUM
DIL
1
* r
OIL
SETTLING
TANK
1
t
pnoi iMr;
1 WATER
AIR — * OXIDIZING
* KETTLES
-••AIR ^
RESINS
HEATER
LINOLEUM
I MIX
COOLING
WATER
T
ALLOWED
TO HARDEN
LINOLEL
CEME
UM
T
ED
JM
"I .
MIXING
VAT
PIGM
FILLERS
ENTS
i
STEAM
JACKETED
MIXER
LINOLEUM MIX
GERMAN
SCRATCHER
SCRATCH
SCRATCH
STOVE
TO
SHIPING
-------
subsequently applied to the sheeted mix and rolled under
pressure.
The rotary inlaying process is somewhat different. The mix
is first blanketed between rolls without backing and passes
down conveyors to inlaying cylinders equipped with knives
set in a pattern, which cut out geometrical sections of the
sheet and press them against the backing. The remainder of
the sheet is reused. Other sheets of different colors and
patterns are cut and applied to the backing at subsequent
stations to make up the complete design. The various pieces
are then consolidated by being passed through heated rollers
to key the surface to the backing.
In the manufacture of molded linoleum, the mix is applied in
granular form to the backing rather than being made into a
blanket. Several different colors are applied through
stencils to various parts of the backing until the whole
pattern is built up. The backing moves horizontally,
stopping at a number of stations where various colors are
applied. The loose mix is consolidated by being compressed
at 112 kg/sq cm (1600 psi), between the heated platens of a
hydraulic press. The sheet is then cured.
Backing
Burlap was the standard backing for linoleum until a
shortage of jute during World War II led to a study of
replacement materials. Canvas has been used with some
success, but felt similar to roofing felt is generally used,
particularly in the lighter gages.
Curing linoleum
Linoleum is hung in large ovens to give it the desired
surface hardness. A temperature of 66-82°C (150-180°F) is
maintained during the maturing. Since maturing does not
depend primarily on oxidation, forced circulation of air is
not usually provided.
The time in the stove depends principally on the thickness
of the linoleum and increases with the gage. Other factors,
such as the composition, may have an effect, but play a
lesser role in the process. The rate of maturing is
carefully controlled, since overstoving can make a product
too stiff.
When the linoleum has satisfactorily matured, a process
which requires from a few days to seven weeks, the material
is removed from the stoves. The surface may then be given a
31
-------
thin coating of lacquer or wax to protect it during
installation. The edges are then trimmed, and the linoleum
is inspected for possible surface imperfections. The
linoleum is then rolled and crated for shipment.
Production of Printed Felt Base
This low-cost floor covering is produced by printing a heavy
film of paint on asphalt-saturated felt to which one or two
layers of sealant have been applied to keep the asphalt from
discoloring the paint and to level the surface. A backing
coat is simultaneously applied. The coating paints used for
sealing and leveling the felt contain linseed, soybean,
tung, fish or oiticica oil. Natural or synthetic resins are
used in these vehicles, and emulsion paints or solvent-
thinned vehicles are also employed. The backing is applied
with a doctor blade, which smooths the coating and trims the
excess. This coating is dried in a heated tunnel. The face
of the felt is coated on a revolving drum and the first
coating paint is applied with a doctor blade and stoved. A
second layer of coating paint is applied, and the coated
felt is again dried by festooning in the oven.
The requirements for a satisfactory paint are rather severe
since it must: (1) have a low volatility when applied; (2)
exhibit little tendency to flow; (3) dry readily in films
much thicker than those usually applied in painting
operations; and (4) produce a durable, high-gloss wearing
surface. The vehicle used in the enamels is comparable to a
long-oil varnish. Ester gum "pure" and rosin-modified
phenolic resins have been used in the vehicle, and alkyd
resins have also been employed. Tung oil is employed in the
manufacture of the enamels and its hardness and reduced
water susceptibility are desirable qualities. Oiticica oil
may also be used in print paints, as well as dehydrated
castor oil.
The paint was once printed on the felt base from wooden
blocks, but rotogravure printing became more generally
employed. Many colors are applied and each is printed
separately. The printed felt is then dried in ovens, heated
to 66-79°C (150-175°F), either in horizontal racks or in
festoons. The felt base matures in a few days and is then
inspected, rolled, and packaged for shipment.
32
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SECTION IV
INDUSTRIAL CATEGORIZATION
Cateqori z ation
In developing these effluent limitations guidelines for the
Asphalt Paving and Roofing Industry, the question arose as
to whether limitations and standards are appropriate for
different segments (subcategories) within the industry. In
arriving at an answer, the following factors were
considered:
1. Wastewater characteristics
2. Wastewater treatability
3. Raw materials used
4. Manufacturing processes (operations)
5. Size of facilities
6. Age of facilities
7. Location of facilities
After considering all the parameters, manufacturing
processes were selected as the bases for establishing the
following subcategories:
1. Asphalt Emulsion Plants
2. Asphalt Concrete Plants
3. Asphalt Roofing Plants
4. Linoleum and Printed Asphalt Felt Plants
Rationale for Selection of Subcategories
Wastewater Characteristics
The waste waters generated originate from one of two
processes: cooling or cleanup operations. While there are
distinct differences in the quality and quantity of the
various wastewaters generated, they are directly related to
the product manufactured and the manufacturing process
employed. As an example, in plants that produce asphalt
concrete, the average flow expected is 68 cu m/day (0.018
mgd) and the average expected suspended solids level is
13,876 mg/1, while in plants that produce asphalt emulsions
the average expected flow is 1,895 cu m/day (0.50 mgd) and
the expected suspended solids level is 58 mg/1. The
suspended solids value is higher for plants that produce
asphalt concrete because they use a vast amount of crushed
rock and this results in more fines being collected in the
33
-------
wastewaters. Plants that produce asphalt emulsions use no
rock. Since wastes generated are similarly related to
products and processes in the remainder of the industry, a
subcategorization on this basis is not warranted, because it
is effectively accomplished by the manufacturing process
employed.
Wastewater Treatability
The waste waters generated by the plants in this industry
contain as major pollutants, nonfilterable suspended solids,
and freon extractable oil and grease. The suspended solids
are usually treated by sedimentation and the oils by a oil
skimmer. The concentrations of each parameter may vary
within the industry, but they do not warrant
subcategorization.
Raw^Materjals Used
The major raw materials used in the industry is the residual
from the distillation of crude oil, called asphalt. By
mixing or coating other raw materials with asphalt,
different products result. The secondary raw materials are:
sand, gravel, organic or asbestos felts, and water. While
there are a number of distinctions related to the raw
material used, the data collected indicate that the
differences are not sufficiently important to form a basis
for subcategorization.
Manufacturing Processes (Operatigns|
The manufacturing processes used in the production of a
given product in this industry differ sufficiently to
support subcategorization. The principal processes employed
in producing asphalt emulsions are forcing hot air through
"crude" asphalt and mixing the "oxidized" asphalt with water
and a chemical solution.
The process employed to produce asphalt concrete "black top"
is simply the mixing of asphalt with crushed rock or gravel.
The process employed to produce asphalt roofing consists of
saturating and coating an organic felt with asphalt. The
coated felt may then be impregnated with crushed rock on one
side.
The processes employed to produce linoleum and printed
asphalt felts call for saturating an organic felt with
asphalt and then painting or embedding a design on one side
of the saturated felt.
34
-------
Manufacturers of several of the above mentioned products
vary their production process, but the resulting differences
are too slight to warrant further subcategorization.
Plant Size
Plant size alone was not found to be a factor in further
subcategorizing the industry. The operational efficiency,
quality of housekeeping, labor availability, and wastewater
characteristics of the plants do not differ because of size
variations. In some instances, a large plant uses less
water than a smaller one because the former employs better
housekeeping practices.
Plant size does not affect the type or performance of
effluent control measures. As described in Section VII, the
basic waste treatment operation for this industry is
sedimentation. Design is based on hydraulic flow rate and
plants with smaller discharges can use smaller and somewhat
less costly treatment units. The approximate daily
production ranges for the product categories were reported
to be:
kJS3 Tons
Asphalt Emulsions 1,813-9,072 2,000-10,000
Asphalt Concrete 363-1,089 400- 1,200
Asphalt Roofing 181- 635 200- 700
Linoleum-Printed Felts 14- 41 15-45
Plant Age
The ages of the plants in the industry range from less than
one to over 50 years. The manufacturing equipment is often
newer than the building housing the plant; in some cases,
however, used machines have been installed in new plants.
Plant age could not be correlated with operational
efficiency, quality of housekeeping, or wastewater
characteristics, therefore it is not an appropriate basis
for subcategorizing the industry.
Geographic Location
Plants in the asphalt paving industries are located near
most, if not all, cities in the United States that house a
Federal, State, County, or City highway department. Asphalt
roofing plants are located throughout the United States but
generally are located along the East, West, and Gulf Coasts.
This wide geographic spread may influence the yearly
production rate, but the wastewater characteristics are
35
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basically the same. Therefore subcategorization based on
geographic location is not warranted.
36
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SECTION V
WASTE CHARACTERIZATION
General Uses
These four subcategories generally use water for cooling,
air emission control, and/or cleanup purposes. The quantity
of water expended varies, but the wastewaters contain
basically the same pollutants.
The waters used for heat-reduction purposes are employed
basically in cooling pumps, agitator bearings, rotating
shafts, glands, and process controls. In the asphalt
roofing subcategory, water is also used to cool asphalt
saturated felts before they are packaged. The use of water
for air emission control and cleanup purposes are self
explanatory.
Specific Uses
Asphalt Emulsion Plants
The major water use at plants in this subcategory is for
cooling pumps and process controls. The water is generally
noncontact in nature and is, therefore, relatively pollutant
free. Runoff caused by precipitation is the only known
source of contaminated water. It contains high
concentrations of oils; a maximum value of 50 mg/1 was
reported. At older plants or at plants where poor
housekeeping practices are common, the production area
grounds are usually saturated with oils and asphalt. At
older plants, it used to be common practice to control dust
by spraying waste oil on plant grounds. Oil leaking out of
pump seals and packing glands and spills at loading docks
also tend to saturate the surrounding grounds. When
precipitation falls, some of the accumulation is carried off
and deposited in nearby receiving waters.
Asphalt Concrete Plants
In this subcategory, water is used only to control air
emissions. Various types of water scrubbers are employed to
collect dust given off during drying and mixing operations.
The characteristics of the raw wastewater were developed
from reported data and from telephone conversations. The
major constitutents in these wastewaters are:
37
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Parameter
Total Solids
Total Suspended Solids
Alkalinitv
mq/1
14,568
13,876
420
kq/kkg*
15.19
14.47
0.44
lb/1fOOO Ib*
15.19
14.47
0.44
*The average production and flow rate are 544 kkg/day
(600 ton/day) and 68 cu m/day (.018 mgd), respectively.
The nature of the solids content varies with geographic
location. The type of rock used in the mix depends on its
availability. If a carbonate-type rock is used, the amount
of solids collected in the wastewater will be higher than if
igneous rock is employed. If a limestone rock is used, pH
values will be high.
The oil and grease content of the raw wastewater was
reported to range from less than detectable to 8 mg/1.
Asphalt Roofing Plants
Water is used in this subcategory to cool the product and
process controls. Only 10-25% of the total volume is used
for the latter purposes.
The product is cooled by one or both of the following
methods. First, water is circulated through cylinders
(called cooling drums) around which the saturated felt
passes. This water is allowed to cool then is recirculated
through the cooling drums. In the second method, a fine
mist is sprayed directly on the saturated felt. The volume
of water used depends on whether the first method has been
employed. If it has been, the rate is 11 1/min (3 gpm),
otherwise the rate is 394 to 657 1/min (104 to 174 gpm).
When both methods are used very little wastewater is
discharged because 75-80% of the small amount of water
sprayed on the saturated felt evaporates. When only the
second method is used, almost all of the water sprayed onto
the saturated felt is discharged. Many plant managers are
now using this water for other processes that call for
heated water. It should be noted that approximately 50% of
the plants in this subcategory produce their own felt. The
heated waters can be used as "white water" makeup. The felt
making process is covered under the effluent guideline
development document entitled "Builders Paper and Board
Manufacturing Point Source Category."
The characteristics of the wastewaters from plants in this
subcategory were developed from sampling data and from
reported values. Typical values for different parameters
are:
38
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_ Parameter
BOD5
Total Solids
Total Dissolved
Total Suspended
Oil-Grease
Solids
Solids
mg/1
12.3
546
277
184
15.4
kq/kkq*
.0154
.6830
.3465
.2302
.0193
lb/1fOOO
.0154
.6830
.3465
.2302
.0193
lh*
*The average production and flow rates are 454 kkg/day
(500 tons/day) and 569 cu in/day (0.15 mgd) , respectively.
The amount of solids present in the wastewater depends on
the method of cooling used. Hardly any solids reach the
wastewaters if the first method or both methods are used.
If only the second method is used, the direct cooling of the
saturated felts washes some of the granules off. The nature
of these solids depends on the type of crushed rock that is
being used. Another source of solids is the backing
material (usually mica or talc) employed to keep the
finished product from sticking when packaged. When water is
sprayed on the felt to cool it some of the backing material
is washed off.
Almost all roofing plants have a tower where asphalt is
oxidized, and the grounds around it may be saturated with
oils and grease. The runoff from such areas is usually
sewered along with the cooling waters.
Linoleum and Printed Asphalt Felt Plants
The major source of wastewater in this subcategory is
cleanup operations. Water is also used to prepare the dyes
which are mixed with the paints, but this water is
consolidated with the end product. Solvents are used in
certain clean up operations, but the spent solvent is
usually reclaimed and the resulting sludges are disposed of
in drums.
The characteristics of these cleanup waters in this
subcategory were developed from reported data and from plant
inspections. Typical values are:
_ Parameter
BOD5
Total Solids
Total Suspended Solids
Total Nitrogen
Phenols
mq/1
8
470
11
1.3
0.02
Kq/kkq*
.0067
.3920
.0092
.0011
.00002
lb/1.000 Ib*
.0067
.3920
.0092
.0011
.00002
*The average production and flow rates are 27 kkg/day
(30 tons/day) and 23 cu m/day (0.006 mgd), respectively.
39
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The solids content usually consists of dried paint. The
mixing vats in which the dyes are prepared are steam
cleaned, and the resulting condensate is the wastewater
source.
40
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SECTION VI
POLLUTANT PARAMETERS
Selected Parameters
The chemical, physical, and biological parameters that
define the pollutants in wastewaters from this industry are:
Total Suspended Solids Dissolved Solids
Oils and Grease Nitrogen
pH Phosphorus
Temperature Phenols
BOD5 Heavy metals
COD (or TOC)
All pollutant parameters except TSS, oils and grease, pH,
and temperature are not normally present in high
concentrations, but they have been included because
significant levels of one or more have been detected in the
effluent from individual plants.
Pollutants in non-process wastewater, such as those from
boiler blowdown and from water treatment facilities are not
included in this document.
The rationale for selecting the listed parameters is given
below.
Major Pollutants
Total,Suspended Solids
Suspended solids include both organic and inorganic
materials. The inorganic components include sand, silt, and
clay. The organic fraction includes such materials as
grease, oil, tar, animal and vegetable fats, various fibers,
sawdust, hair, and various materials from sewers. These
solids may settle out rapidly and bottom deposits are often
a mixture of both organic and inorganic solids. They
adversely affect fisheries by covering the bottom of the
stream or lake with a blanket of material that destroys the
fish-food bottom fauna or the spawning ground of fish.
Deposits containing organic materials may deplete bottom
oxygen supplies and produce hydrogen sulfide, carbon
dioxide, methane, and other noxious gases.
41
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In raw water sources for domestic use, state and regional
agencies generally specify that suspended solids in streams
shall not be present in sufficient concentration to be
objectionable or to interfere with normal treatment
processes. Suspended solids in water may interfere with
many industrial processes, and cause foaming in boilers, or
encrustations on equipment exposed to water, especially as
the temperature rises. Suspended solids are undesirable in
water for textile industries; paper and pulp; beverages;
dairy products; laundries; dyeing; photography; cooling
systems, and power plants. Suspended particles also serve
as a transport mechanism for pesticides and other substances
which are readily sorbed into or onto clay particles,.
Solids may be suspended in water for a time, and then settle
to the bed of the stream or lake. These settleable solids
discharged with man's wastes may be inert, slowly
biodegradable materials, or rapidly decomposable substances.
While in suspension, they increase the turbidity of the
water, reduce light penetration and impair the
photosynthetic activity of aquatic plants.
Solids in suspension are aesthetically displeasing. When
they settle to form sludge deposits on the stream or lake
bed, they are often much more damaging to the life in water,
and they retain the capacity to displease the senses.
Solids, when transformed to sludge deposits, may do a
variety of damaging things, including blanketing the stream
or lake bed and thereby destroying the living spaces for
those benthic organisms that would otherwise occupy the
habitat. When of an organic and therefore decomposable
nature, solids use a portion or all of the dissolved oxygen
available in the area. Organic materials also serve as a
seemingly inexhaustible food source for sludgeworms and
associated organisms.
Turbidity is principally a measure of the light absorbing
properties of suspended solids. It is frequently used as a
substitute method of quickly estimating the total suspended
solids when the concentration is relatively low.
The suspended solids levels in wastewater at plants in these
four subcategories vary from a low of less than 10 mg/1 to a
high of over 35,000 mg/1. The solids are generally heavy
and settle quickly. The nature of the solids depends on the
plant locale and the type of readily available rock that is
used in the processes. Usually when carbonate rocks are
used, a higher level of suspended solids results, and a
lower level occurs when igneous rocks are employed. If
42
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discharged into a stream or lake, these solids would blanket
the bottom, cause turbidity, and possibly harm aquatic life.
Oil and Grease
Oil and grease exhibit an oxygen demand. Oil emulsions may
adhere to the gills of fish or coat and destroy algae or
other plankton. Deposition of oil in the bottom sediments
can serve to inhibit normal benthic growths, thus
interrupting the aquatic food chain. Soluble and emulsified
material ingested by fish may taint the flavor of the fish
flesh. Water soluble components may exert toxic action on
fish. Floating oil may reduce the re-aeration of the water
surface and in conjunction with emulsified oil may interfere
with photosynthesis. Water insoluble components damage the
plumage and coats of water animals and fowls. Oil and
grease in a water can result in the formation of
objectionable surface slicks preventing the full aesthetic
enjoyment of the water.
Oil spills can damage the surface of boats and can destroy
the aesthetic characteristics of beaches and shorelines.
The oils found at plants in these four subcategories are
usually floating oils and their concentrations range from
less than 0.1 mg/1 to over 50 mg/1.
pH. Acidity and Alkalinity
Acidity and alkalinity are reciprocal terms. Acidity is
produced by substances that yield hydrogen ions upon
hydrolysis and alkalinity is produced by substances that
yield hydroxyl ions. The terms "total acidity" and "total
alkalinity" are often used to express the buffering capacity
of a solution. Acidity in natural waters is caused by
carbon dioxide, mineral acids, weakly dissociated acids, and
the salts of strong acids and weak bases. Alkalinity is
caused by strong bases and the salts of strong alkalies and
weak acids.
The term pH is a logarithmic expression of the concentration
of hydrogen ions. At a pH of 7, the hydrogen and hydroxyl
ion concentrations are essentially equal and the water is
neutral. Lower pH values indicate acidity while higher
values indicate alkalinity. The relationship between pH and
acidity or alkalinity is not necessarily linear or direct.
Waters with a pH below 6.0 are corrosive to water works
structures, distribution lines, and household plumbing
fixtures and can thus add such constituents to drinking
43
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water as iron, copper, zinc, cadmium and lead. The hydrogen
ion concentration can affect the "taste" of the water. At a
low pH water tastes "sour". The bactericidal effect of
chlorine is weakened as the pH increases, and it is
advantageous to keep the pH close to 7. This is very
significant for providing safe drinking water.
Extremes of pH or rapid pH changes can exert stress
conditions or kill aquatic life outright. Dead fish,
associated algal blooms, and foul stenches are aesthetic
liabilities of any waterway. Even moderate changes from
"acceptable" criteria limits of pH are deleterious to some
species. The relative toxicity to aquatic life of many
materials is increased by changes in the water pH.
Metalocyanide complexes can increase a thousand-fold in
toxicity with a drop of 1.5 pH units. The availability of
many nutrient substances varies with the alkalinity and
acidity. Ammonia is more lethal with a higher pH.
The lacrimal fluid of the human eye has a pH of
approximately 7.0 and a deviation of 0.1 pH unit from the
norm may result in eye irritation for the swimmer.
Appreciable irritation will cause severe pain.
The wastewaters from these four subcategories may contain
carbonate rock dust that results in elevated pH values. The
values for pH may range from a low of 5.0 to a high of 12.0.
Any values outside the range of 6.0 to 9.0 are harmful to
aquatic life.
Other Pollutants
The following parameters were considered in the course of
this study, but were not included for either or both of the
following reasons: 1) only insignificant amounts were found
in the wastewaters; 2) insufficient data were available upon
which to base a limitation.
Biochemical Oxygen Demand (BOD)
Biochemical oxygen demand (BOD) is a measure of the oxygen
consuming capabilities of organic matter. The BOD does not
in itself cause direct harm to a water system, but it does
exert an indirect effect by depressing the oxygen content of
the water. Sewage and other organic effluents during their
processes of decomposition exert a BOD, which can have a
catastrophic effect on the ecosystem by depleting the oxygen
supply. Conditions are reached frequently where all of the
oxygen is used and the continuing decay process causes the
production of noxious gases such as hydrogen sulfide and
44
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methane. Water with a high BOD indicates the presence of
decomposing organic matter and subsequent high bacterial
counts that degrade its quality and potential uses.
Dissolved oxygen (DO) is a water quality constituent that,
in appropriate concentrations, is essential not only to keep
organisms living but also to sustain species reproduction,
vigor, and the development of populations. Organisms
undergo stress at reduced DO concentrations that make them
less competitive and able to sustain their species within
the aquatic environment. For example, reduced DO
concentrations have been shown to interfere with fish
population through delayed hatching of eggs, reduced size
and vigor of embryos, production of deformities in young,
interference with food digestion, acceleration of blood
clotting, decreased tolerance to certain toxicants, reduced
food efficiency and growth rate, and reduced maximum
sustained swimming speed. Fish food organisms are likewise
affected adversely in conditions with suppressed DO. Since
all aerobic aquatic organisms need a certain amount of
oxygen, the consequences of total lack of dissolved oxygen
due to a high BOD can kill all inhabitants of the affected
area.
If a high BOD is present, the quality of the water is
usually visually degraded by the presence of decomposing
materials and algae blooms due to the uptake of degraded
materials that form the foodstuffs of the algal populations.
The BOD5 levels in the wastewaters from these four
subcategories are usually very low -zero to 50 mg/1.
Temperature
Temperature is one of the most important and influential
water quality characteristics. Temperature determines those
species that may be present; it activates the hatching of
young, regulates their activity, and stimulates or
suppresses their growth and development; it attracts, and
may kill when the water becomes too hot or becomes chilled
too suddenly. Colder water generally suppresses
development. Warmer water generally accelerates activity
and may be a primary cause of aquatic plant nuisances when
other environmental factors are suitable.
Temperature is a prime regulator of natural processes within
the water environment. It governs physiological functions
in organisms and, acting directly or indirectly in
combination with other water quality constituents, it
affects aquatic life with each change. These effects
45
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include chemical reaction rates, enzymatic functions,
molecular movements, and molecular exchanges between
membranes within and between the physiological systems arid
the organs of an animal.
Chemical reaction rates vary with temperature and generally
increase as the temperature is increased. The solubility of
gases in water varies with temperature. Dissolved oxygen is
decreased by the decay or decomposition of dissolved organic
substances and the decay rate increases as the temperature
of the water increases reaching a maximum at about 30 °C
(86°F) . The temperature of stream water, even during
summer, is below the optimum for pollution-associated
bacteria. Increasing the water temperature increases the
bacterial multiplication rate when the environment is
favorable and the food supply is abundant.
Reproduction cycles may be changed significantly by
increased temperature because this function takes place
under restricted temperature ranges. Spawning may not occur
at all because temperatures are too high. Thus, a fish
population may exist in a heated area only by continued
immigration. Disregarding the decreased reproductive
potential, water temperatures need not reach lethal levels
to decimate a species. Temperatures that favor competitors,
predators, parasites, and disease can destroy a species at
levels far below those that are lethal.
Fish food organisms are altered severely when temperatures
approach or exceed 90°F. Predominant algal species change,
primary production is decreased, and bottom associated
organisms may be depleted or altered drastically in numbers
and distribution. Increased water temperatures may cause
aquatic plant nuisances when other environmental factors are
favorable.
Synergistic actions of pollutants are more severe at higher
water temperatures. Given amounts of domestic sewage,
refinery wastes, oils, tars, insecticides, detergents, and
fertilizers more rapidly deplete oxygen in water at higher
temperatures, and the respective toxicities are likewise
increased.
When water temperatures increase, the predominant algal
species may change from diatoms to green algae, and finally
at high temperatures to blue-green algae, because of species
temperature preferentials. Blue-green algae can cause
serious odor problems. The number and distribution of
benthic organisms decreases as water temperatures increase
above 90°F, which is close to the tolerance limit for the
46
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population. This could seriously affect certain fish that
depend on benthic organisms as a food source.
The cost of fish being attracted to heated water in winter
months may be considerable, due to fish mortalities that may
result when the fish return to the cooler water.
Rising temperatures stimulate the decomposition of sludge,
formation of sludge gas, multiplication of saprophytic
bacteria and fungi (particularly in the presence of organic
wastes), and the consumption of oxygen by putrefactive
processes, thus affecting the esthetic value of a water
course.
In general, marine water temperatures do not change as
rapidly or range as widely as those of freshwaters. Marine
and estuarine fishes, therefore, are less tolerant of
temperature variation. Although this limited tolerance is
greater in estuarine than in open water marine species,
temperature changes are more important to those fishes in
estuaries and bays than to those in open marine areas,
because of the nursery and replenishment functions of the
estuary that can be adversely affected by extreme
temperature changes.
Thermal increases are caused by contact and non-contact
cooling waters. Reported temperatures for effluents reach
maximum levels of 71°C (160°F). This water is either
recycled into the process water or allowed to cool before
being used again as a cooling water.
Dissolved Solids
In natural waters the dissolved solids consist mainly of
carbonates, chlorides, sulfates, phosphates, and possibly
nitrates of calcium, magnesium, sodium, and potassium, with
traces of iron, manganese and other substances.
Many communities in the United States and in other countries
use water supplies containing 2,000 to 4,000 mg/1 of
dissolved salts, when no better water is available. Such
waters are not palatable, may not quench thirst, and may
have a laxative action on new users. Waters containing more
than 4,000 mg/1 of total salts are generally considered
unfit for human use, although in hot climates such higher
salt concentrations can be tolerated whereas they could not
be in temperate climates. Waters containing 5,000 mg/1 or
more are reported to be bitter and act as bladder and
intestinal irritants. It is generally agreed that the salt
47
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concentration of good, palatable water should not exceed 50C
mg/1.
Limiting concentrations of dissolved solids for fresh-water
fish may range from 5,000 to 10,000 mg/1, according to
species and prior acclimatization. Some fish are adapted to
living in more saline waters, and a few species of fresh-
water forms have been found in natural waters with a salt
concentration of 15,000 to 20,000 mg/1. Fish can slowly
become acclimatized to higher salinities, but fish in waters
of low salinity cannot survive sudden exposure to high
salinities, such as those resulting from discharges of oil-
well brines. Dissolved solids may influence the toxicity of
heavy metals and organic compounds to fish and other aquatic
life, primarily because of the antagonistic effect of
hardness on metals.
Waters with total dissolved solids over 500 mg/1 have
decreasing utility as irrigation water. At 5,000 mg/1 water
has little or no value for irrigation.
Dissolved solids in industrial waters can cause foaming in
boilers and cause interference with cleanness, color, or
taste of many finished products. High contents of dissolved
solids also tend to accelerate corrosion.
Specific conductance is a measure of the capacity of water
to convey an electric current. This property is related to
the total concentration of ionized substances in water and
water temperature. This property is frequently used as a
substitute method of quickly estimating the dissolved solids
concentration.
The dissolved solids levels are high in all four
subcategories and range from 60 mg/1 to 850 mg/1. These
levels do not warrant the added expense of removal.
Nitrogen-Phosphorus
During the past 30 years, a formidable case has developed
for the belief that increasing standing crops of aquatic
plant growths, which often interfere with water uses and are
nuisances to man, frequently are caused by increasing
supplies of phosphorus. Such phenomena are associated with
a condition of accelerated eutrophication or aging of
waters. It is generally recognized that phosphorus is not
the sole cause of eutrophication, but there is evidence to
substantiate that it is frequently the key element in all of
the elements required by fresh water plants and is generally
present in the least amount relative to need. Therefore, an
48
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increase in phosphorus allows use of other, already present,
nutrients for plant growths. Phosphorus is usually
described, for this reasons, as a "limiting factor."
When a plant population is stimulated in production and
attains a nuisance status, a large number of associated
liabilities are immediately apparent. Dense populations of
pond weeds make swimming dangerous. Boating and water
skiing and sometimes fishing may be eliminated because of
the mass of vegetation that serves as an physical impediment
to such activities. Plant populations have been associated
with stunted fish populations and with poor fishing. Plant
nuisances emit vile stenches, impart tastes and odors to
water supplies, reduce the efficiency of industrial and
municipal water treatment, impair aesthetic beauty, reduce
or restrict resort trade, lower waterfront property values,
cause skin rashes to man during water contact, and serve as
a desired substrate and breeding ground for flies.
Phosphorus in the elemental form is particularly toxic, and
subject to bioaccumulation in much the same way as mercury.
Colloidal elemental phosphorus will poison marine fish
(causing skin tissue breakdown and discoloration). Also,
phosphorus is capable of being concentrated and will
accumulate in organs and soft tissues. Experiments have
shown that marine fish will concentrate phosphorus from
water containing as little as 1 ug/1.
Nitrogen levels in raw wastewaters from these subcategories
are normally low; they usually range from less than 0.1 mg/1
to 21.79 mg/1 of total nitrogen. Nitrogen was included
because at this level, it could influence eutrophication
rates in some water bodies.
Phosphorus levels reported in the wastewaters from these
subcategories range from 0.01 mg/1 to 3.38 mg/1 This element
can also influence eutrophication and should be monitored to
ensure that levels are acceptably low.
Phenols
Phenols and phenolic wastes are derived from petroleum,
coke, and chemical industries; wood distillation; and
domestic and animal wastes. Many phenolic compounds are
more toxic than pure phenol; their toxicity varies with the
combinations and general nature of total wastes. The effect
of combinations of different phenolic compounds is
cumulative.
-------
Phenols and phenolic compounds are both acutely and
chronically toxic to fish and other aquatic animals. Also,
chlorophenols produce an unpleasant taste in fish flesh that
destroys their recreational and commercial value.
It is necessary to limit phenolic compounds in raw water
used for drinking water supplies, as conventional treatment
methods used by water supply facilities do not remove
phenols. The ingestion of concentrated solutions of phenols
will result in severe pain, renal irritation, shock and
possibly death.
Phenols also reduce the utility of water for certain
industrial uses, notably food and beverage processingv where
it creates unpleasant tastes and odors in the product,
The presence of measurable phenol levels has been reported
in wastes from all four subcategories, but the levels
reported were all less than 1 mg/1. Even though the levels
are low, these chemicals can cause serious taste and odor
problems in the receiving water. Phenol discharges should
be monitored to ensure that levels are acceptably low.
Heavy Metals
Individual plants have reported that one or more of the
following metals were present in trace quantities in their
effluents: cadmium, chromium, copper, iron, lead, nickel,
zinc, aluminum, calcium, fluoride, chloride, magnesium, and
potassium.
Several of the plants also reported that arsenics and
cyanides were present. These materials, which originate in
the stone or rock that is used, were at levels well below
those specified as being safe for drinking water.
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SECTION VII
CONTROL AND TREATMENT TECHNOLOGY
Summary
The discharge of wastewater from mills in the asphalt
paving, roofing, and flooring industries into receiving
waters can be reduced to required levels by the
conscientious application of established in-plant controls
against process losses and water recycling measures and by
well-designed and operated external treatment facilities.
This section describes in-plant and external technologies
which are in wide use or are under development to achieve
various levels of pollutant reduction. External technology
is used to achieve the final reduction of pollutants
discharged to receiving waters.
Treatment
Sedimentation and various auxiliary operations yield an
effluent that has a low pollution potential when properly
applied. The settled solids are inert, dense, and suitable
for disposal in a landfill.
Treatment beyond sedimentation and oil control is not
necessary for wastes from this industry. The only pollutant
constituent present at significant levels is dissolved
solids. While these may be found at undesirably high levels
in certain industrial water uses, they do not present
serious hazards to human health or to aquatic life. To
remove the dissolved solids would require advanced treatment
techniques, e.g., reverse osmosis, electrodialysis, or
distillation. The initial and annual costs associated with
such operations are so high that alternative solutions—
complete recycle of wastewaters—will be implemented by the
industry instead of providing further treatment.
During the course of the study carried out to prepare this
document, it was found that approximately 3,100 plants in
this industry are considering, developing, or implementing
the complete recirculation of wastewaters. This estimate is
based on statements made by the industry that approximately
Q0% of the plants are currently recycling their production
waters.
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Implementation
The in-plant control measures and end-of-pipe treatment
technology outlined below can be implemented as necessary
throughout the industry. Factors relating to plant and
equipment age, manufacturing process and capacity, and land
availability do not play a significant role in determining
whether a given plant can make the changes. Implementation
of a particular control or treatment measure will involve
approximately equal degrees of engineering and process
design skill and will have the same effects on plant
operations, product quality, and process flexibility at all
locations.
In-Plant ContrQl_Measures
Many plants in this industry incorporate some in-plant
practices that simultaneously reduce the release of
pollutant constituents and result in economic benefits,
e.g., reduced water supply or waste disposal costs, or both.
Wastewater Segregation
In all cases, sanitary sewage should be disposed of
separately from process wastewaters. Public health
considerations as well as economic factors dictate that
sanitary wastes not be combined with these wastewaters.
Housekeeping Practices
Conscientious housekeeping is by far the most important in-
house measure that influences wastewater characteristics.
If all sump areas are kept clean and open and all loose
materials are swept up, the amount of solids reaching the
final discharge point will be drastically reduced.
Water Usage
Fresh water should be used first for pump seals, steam
generation, showers, and in similar applications where high
contaminated levels cannot be tolerated. The discharges
should then go into the manufacturing process as make-up
water and for other purposes when water quality is less
critical.
Water conservation equipment and practices should be
installed to prevent overflows, spills, and leaks. Plumbing
arrangements that discourage the unnecessary use of fresh
water should be incorporated.
52
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Control Measures By Subcategorv
Asphalt Emulsion Plants
Approximately eight plants in this subcategory are currently
recycling some of their cooling waters by using a cooling
tower or a cooling basin. To control contaminated runoff,
all areas where spills have occurred or where one might
occur, have been paved to collect runoff or collection sumps
have been constructed under the areas. The cooling water
flow is typically in the range of .105 to .418 cu m/kkg (25
to 100 gal/ton) of product.
Asphalt Concrete Plants
Approximately 3,100 plants in this subcategory are currently
practicing complete recycle and 1,200 use no water at all.
Typical flows from a wet collection system are in the range
of 0.094 to 0.125 cu m/kkg (22.5 to 30 gal/ton) of product.
Asphalt Roofing Plants
Approximately 23 plants in this subcategory practice some
sort of recycle. A major factor that is considered in
recycling water is its dissolved solids content. Several of
the plants that recycle their contact cooling water have
found that high levels of dissolved solids cause some
discoloration in the product. These levels vary so much
that no determination has yet been made as to what levels
cause discoloration. The darker the coating granules are,
the higher the dissolved solids content can be before
discoloration begins.
The success of these 23 plants proves that water usage can
be cut down in this subcategory. Splash or spray water can
be eliminated if cooling drums are installed. The cooling
drums represent essentially a noncontact system, and the
water used is relatively pollutant free. In some cases, a
fine mist spray is used in conjunction with the cooling
drums. The mist is sprayed only on the back of the
saturated felt and almost 75-80% of this water is
evaporated.
Good housekeeping practices in this subcategory will prevent
high concentrationsof solids from entering the wastewater.
If all sump areas are kept clean and all loose material on
the floors are kept swept up, the concentrations of
suspended solids are usually in the range of 100 to 884
mg/1.
53
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Typically wastewater flows from plants in this subcategory
are influenced by the type of cooling system used. The
range of flow therefore is 1.49 to 2.09 cu m/kkg (357 to 500
gal/ton) of product.
Linoleum and Printed Asphalt Felt Plants
The only known in-house method used to reduce pollutant
concentrations is good housekeeping practices. All wash
waters flow into sumps where the solids settle and are
removed. If these sumps are kept clean, the solids
concentrations can be kept low. Typical flow ranges at
these plants are .57 to .93 cu m/kkg (133.33 to 222.22
gal/ton) of product.
Treatment Technology
Most plants in this industry treat their raw wastewaters in
some way before discharging them. In virtually all cases,
this treatment is sedimentation. Fortunately, the waste
solids are dense and almost any period of detention will
accomplish major removals.
Technical Considerations
Sedimentation is the oldest of all treatment unit operations
in sanitary engineering practices. It is well understood
and its costs, ease of operation, efficiency, and
reliability make it ideally suited for industrial
application.
Application
Sedimentation is an appropriate form of treatment for this
industry regardless of plant size and capacity,
manufacturing process, and plant and equipment age. Design
is based on the hydraulic discharge and plants with smaller
effluent volumes can use smaller units. The treatment
system can be sized to accommodate surges and peak flows
efficiently. Because wastes from this industry are
basically inert biologically, overdesign does not result in
solids management problems.
Land Requirements
If necessary, complete settling facilities large enough to
treat the waste flows can be placed on an area no larger
than 0.1 hectare (0.25 acre). Land is usually available to
cover the settled solids.
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Control and Treatment Technologies By Subcatecrory
Asphalt Emulsion Plants
External control at the plants in this subcategory involves
the collecting of the entire runoff flow from the plant
production area. This can be achieved by diking the
perimeter of the plant area or by putting in a sewer
collection system; the runoff can then be treated at a
common point.
Various methods can be used to separate oils from the
wastewater, but the device commonly used in this subcategory
is an oil skimmer. Since the oils encountered are
relatively insoluble and float on the surface of the
wastewater, a good operating system can remove from 75-8535
of them. Other systems may be used, such as air flotation,
emulsion breaking, or deep bed filters, but their high
initial and operating costs may not make them economical for
all plants in the subcategory.
Asphalt Concrete Plants
The external controls at these plants involve treating the
wastewater from a wet collection system for air emissions.
The wastewater has a very high concentration of suspended
solids that settle readily. Sedimentation works well with
this type of wastewater, and an earthen stilling basin or a
mechanical sedimentation basin can be used. The first type
is commonly found at large stationary plants because land is
available, and usually a worked-out gravel pit is used. A
portable mechanical sedimentation basin has been used at
mobile plants, but the earthen stilling basin is the system
usually used. No other system can be used to remove
suspended solids economically, because of the large quantity
involved. The quantity of solids present in the wastewaters
depends on the type of rock being used in the product. A
carbonate-type rock produces more dust and fine granules
when crushed than igneous-types. For example, 1,360 kg
(3,000 Ib) of solids can settle out at a 181 kkg (200 ton)
per-hour plant. The solids that are removed from the
settling system are allowed to dry and are then landfilled.
The landfill need not be lined because the nature of the
solid does not harm the surrounding area.
Asphalt Roofing Plants
The external controls at plants in this subcategory are such
that either a sedimentation or filter unit can be used to
remove the suspended solids present in the wastewater.
55
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Sedimentation can be accomplished in an earthen stilling
basin or a mechanical sedimentation basin. Both can achieve
the desired effluent quality, but the choice of which to use
depends on land availability.
Rapid sand filters and clarifiers can also be used to
achieve the desired effluent quality needed by 1977, but
their initial and operating costs may be too high for some
of the plants in this subcategory.
The 1983 limits are lower than the 1977 requirements,
therefore, the above methods may have to be used. if the
plants use the splash type cooling method, large amounts of
the backing material (mica or talc) are washed off. To meet
the 1983 suspended solids limit, either additional time is
needed for sedimentation or a clarifier must be used.
Depending on the quantity and type of this fine suspended
material, coagulants may have to be used. The resulting
sludge is landfilled. The nature of this sludge does not
warrant the use of lined disposal pits.
Linoleum and Printed Felt Plants
External controls for this subcategory involve passing the
wastewater through an earthen stilling basin or a mechanical
sedimentation basin. The wastewater flow from plants in
this subcategory contains suspended solids that settle
readily. These settled solids may contain potentially
harmful materials. In some cases, settled solids may need
to be disposed of in a manner that will not harm the
environment.
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SECTION VIII
COST, ENERGY, AND NON-WATER QUALITY ASPECTS
Introduction
The plants used to develop representative treatment cost
information were selected because of the relatively high
quality of their treatment facilities, the quantity of
wastewater discharged, the availability of their cost data,
and the adequacy of verified information about the
effectiveness of the treatment facility. The plants used
typical, standard manufacturing processes and incorporated
some of the in-plant contacts described in Section VII.
The end-of-pipe control technologies were designed, for cost
purposes, to require minimal space and land area. It is
believed that no additional land would be required at most
plants. At locations with more land available, larger, more
economical facilities of somewhat different design, but
equal efficiency, could be used.
This cost information is intended to apply to most plants in
these four subcategories. Differences in age or size of
production facilities, level of implementation of in-plant
controls, manufacturing process, and local non-water quality
environmental aspects all reduce to one basic variable, the
volume of wastewater discharged.
Cost Information
Costs that were considered in this document are investment
and annual costs, which are based on the 1973 dollar.
Investment Cost
Design
Land
Mechanical and electrical equipment
Instrumentation
Site preparation
Plant sewers
Construction work
Installation
Testing
Annual Cost
Interest
Depreciation
57
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Operation and maintenance
Energy
Investment Costs
Investment costs are defined as the capital expenditures
required to bring the treatment or control technology into
operation. Included, as appropriate, are the cost of
excavation ($3.00/cu yd), concrete ($1.00/sq ft for 4 in.
thick slabs and $lUO.OO/cu yd for wall construction),
mechanical and electrical equipment installed (varies with
type), piping ($6.50/ft), grating ($2.4C/ft) , and
transportation ($6.00/ton). Additional amounts equal to 1056
and 25% of the total of the above were added to cover
engineering design services and construction supervision,
respectively. Also an additional 10% of the total amount
was added to cover unforeseen costs for new sources (30% for
old sources). It is believed that the interruptions
required for installation of control technologies can be
coordinated with normal plant shut-down and vacation, periods
in most cases. As noted above, the control facilities were
estimated on the basis of minimal space requirements.
Therefore, no additional land, and, hence no cost, would be
involved for this item.
Capital costs
The capital costs are calculated as 10% of total investment
costs.
Depreciation
Straight-line depreciation for 10 years or 10% of the total
investment cost is used in all cases.
Operation and Maintenance Costs
Operation and maintenance costs include labor, materials,
any solid waste disposal, effluent monitoring,, added
administrative expenses, taxes, and insurance. Manpower
requirements were based on the typical number of personnel
needed to operate the required control facilities. A salary
cost of $10 per man-hour was used. The costs of chemicals
used in treatment were added to the costs of materials used
for operation and maintenance.
The costs of solid waste handling and disposal were based
primarily on information supplied by officials operating
solid waste handling facilities.
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Energy and Power Costs
Power costs were estimated on the basis of $0.025 per
kilowatt hour.
Costs By Subcategory
Asphalt Emulsion Plants
All costs for this subcategory were determined for a plant
which has a 4 hectare (10 acre) production area and has no
means to collect runoff.
Best Practicable Control Technology Currently
Available (BPCTCA1
As stated in Section IX, all runoff from the production area
should be collected and treated. Installation and operating
costs that would be incurred at a typical size plant, are
presented in Table 11. It was assumed that: (1) no more
than three inches of rain will fall during a 24-hour period;
(2) a peripheral collection system is necessary and that a
gravity separator is needed to treat the runoff.
Best Available Technology Economically
Achievable (BATEAi
BATEA for the typical asphalt emulsion plant consists of a
sedimentation basin where additional removal of oils and
suspended solids can be achieved. The incremental costs of
achieving BATEA are shown in the second column of Table 11.
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TABLE 11
Treatment Costs in Dollars
For Asphalt Emulsion Plants*
Technology Level
Type Of Cost BPCTCA BATEA+ NSPS
Total Investment Cost
Capital cost
Depreciation and Interest
Operation and Maintenance
Energy
Total Annual Cost
Cost per kkg per day
73,290
7,330
7,330
1,250
190
16,100
0.01
7,500
750
750
625
100
2,225
0.002
72,000
7,200
7,200
1,250
190
15,840
0.01
*Daily Production 5,443 kkg (6,000 ton)
+Marginal costs after BPCTCA has been achieved.
New Source Performance Standards (NSPS)
It is recommended that new sources be required to install
control equipment equivalent to BATEA, and the costs for
doing this at a typical plant are shown in the third column
of Table 11. They are lower than the total for BPCTCA and
the incremental costs of BATEA, because of the reduced
expense associated with the construction and installation of
new facilities.
Asphalt Concrete,Plants
Plants in this subcategory have production capacities
ranging from 91 to 363 kkg/hr (100-400 ton/hr), but during
an average work day, the expected time of actual mixing is
from 2 to 4 hours. On some occasions this range may be 10-
12 hrs., and again it may be 1-2 hours. The length of
actual operation depends on the season, and the type of job
being done.
About 90% of the plants in this subcategory meet the 1977
requirement for BPCTCA, but for cost estimation, plants with
little or no treatment were used. The basic assumptions
that were used to develop costs are: (1) The daily
production levels used were 340 kkg/day (375 ton/day), 544
kkg/day (600 ton/day), and 851 kkg/day (938 ton/day); (2)
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the average expected wastewater flow is 1.04 cu m/kkg (250
gal/ton); (3) a pond large enough to give a 2 hour detention
time; (4) the solids collected per hour of operation amount
to 1,361 kg (3,000 Ib); (5) the pond will be cleaned every
month.
A mechanically cleaned settling tank was considered, but its
high initial and operating costs obviated its use.
The level of treatment required of this subcategory for 1977
is the same as that required in 1983; also new Source
Performance Standards are the same, namely, no discharge.
The incremental costs of applying BPCTCA, BATEA, and NSPS
for each of the three daily production levels are listed in
Table 12.
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TABLE 12
Treatment Costs in Dollars
For Asphalt Concrete Plants*
Daily Production Levels
Type of Cost 340 kkg 544 kkg 851 kkg
(375 ton) (600 ton) (938 ton)
Total Investment Cost 4,600
Capital Cost 460
Depreciation and Interest 460
Operation and Maintenances, 700
Energy 1,375
Total Annual Cost 7,995
Cost per kkg per day 0.12
5,550
555
555
7,265
2,100
10,475
0.10
6,400
640
640
9,600
3,325
14,205
0.08
*The costs needed to achieve BPCTCA, BATEA, and NSPS are
the same.
Asphalt Roofing Plants
The typical plant is assumed to have a capacity of 454
kkg/day (500 ton/day) and a wastewater flow of 569 cu m/day
(0.15 mgd) .
Best^ Practicable control Technology Currently
Available (BPCTCA1
At the majority of plants in this subcategory, large
suspended materials are settled in a pond or detention sump
before the effluent is discharged. BPCTCA requires that all
plants employ primary settling. The costs of BPCTCA have
been developed for situations in which: (1) an earthen
stilling basin is installed; (2) a steel or concrete
settling tank is used. It is assumed that: (1) both are
cleaned monthly by manual methods; (2) sprays or mists are
installed to reduce the volume of wastewater; (3) the use of
coagulants is not needed.
The costs of applying BPCTCA in each situation are shown in
the first column of Tables 13 and 14, respectively.
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Best Available Technology Economically Achievable /BATEA)
Since BATEA assumes that coagulants will be needed to settle
out more suspended solids, the costs of applying BATEA allow
for expenses incurred in having the resulting sludge removed
continuously and mechanically. It is assumed, therefore,
that the earthen stilling basin which is acceptable under
BPCTCA is replaced by a settling tank. The incremental
costs of achieving BATEA (depending on which settling method
is used under BPCTCA) are shown in the second column of
Tables 13 and 14.
TABLE 13
Treatment Costs in Dollars
For Asphalt Roofing Plants*
Earthen Stilling Basin Used
Technology Level
Type Of Cost BPCTCA BATEA+
Total Investment Cost 5,125 50,000
Capital Cost 510 5,000
Depreciation and Interest 510 5,000
Operation and Maintenance 1,600 10,000
Energy 100 375
Total Annual Cost 2,720 20,375
Cost per kkg per day 0.024 0.18
*Daily Production 454 kkg (500 ton)
•••Marginal costs incurred after BPCTCA has been achieved.
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TABLE 14
Treatment costs in Dollars
For Asphalt Roofing Plants*
Settling Tank Used
Type of Cost
Technology Level
BPCTCA BATEA+ NSPS
Total Investment
Capital cost
Depreciation and Interest
Operation and Maintenance
Energy
Total Annual Cost
Cost per kkg per day
24,000
2,400
2,400
1,720
190
6,710
0.059
29,500
2,950
2,950
7,500
280
13,680
0.12
53,500
5,350
5,350
9,220
470
20,379
0.18
*Daily Production 454 kkg (500 ton)
•••Marginal costs incurred after BPCTCA has been achieved.
New Source Performance Standards (NSPS)
NSPS require that the equivalent of BATEA be applied. The
total costs are shown in the third column of Table 14 only
because it is assumed that a new source would use a settling
tank and a continuous, mechanical method of sludge removal.
Lingleum and Printed Asphalt Felt_Plants
The typical plant has a capacity of 27 kkg/day (30 ton/day)
and a wastewater flow of 23 cu m/day (0.006 mgd). It is
assumed that the wastewater is not treated.
Best Practicable Control Technology Currently
Available IBPCTCA)
BPCTCA requires that suspended solids be settled out of the
wastewater prior to discharge. The cost estimate assumes
that a settling tank is installed and that the sludge is
manually removed from it at recurring intervals (Table 15).
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TABLE 15
Treatment Costs in Dollars
For Linoleum and Asphalt Felt Plants*
Type of Cost
Total Investment
CapitalCost
Depreciation and Interest
Operation and Maintenance
Energy
Total Annual Cost
Cost per kkg per day
BPCTCA
3,600
360
360
625
100
1,445
0.21
Technology
BATEA+
2,500
250
250
1,400
470
2,370
0.35
Level
NSPS
6,100
610
610
2,000
570
3,790
0.56
*Daily Production 27 kkg (30 ton)
^Marginal costs incurred after BPCTCA has been achieved.
Best Available Technology Economically Achievable (BATEA)
BATEA requires that coagulants be used to increase the
amount of suspended materials removed. The costs are shown
in the second column of Table 15.
New Source Performance Standards (NSPS)
NSPS requirements dictate that BATEA be applied. Costs are
shown in the third column of Table 15.
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SECTION IX
BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE
The effluent limitations which must be achieved by July 1,
1977, are to specify the degree of effluent reduction
attainable through the application of the best practicable
control technology currently available (BPCTCA). BPCTCA is
generally based on the average of the best levels being
achieved by plants of various sizes, ages, and unit
processes within the subcategory. Consideration was also
given to:
1. The total cost of application of technology in
relation to the effluent reduction benefits to be
achieved from such application.
2. The size, age of equipment, and facilities
involved.
3. The processes employed.
4. The engineering aspects of the application of
various types of control techniques.
5. Process changes
6. Non-water quality environmental impact, including
energy requirements.
BPCTCA emphasizes treatment facilities employed at the end
of a manufacturing process but includes the control
technologies within the process itself when the latter are
considered to be normal practice within the industry.
A further consideration is the degree of economic and
engineering reliability which must be established for the
technology to be "currently available." As a result of
demonstration projects, pilot plants, and general use, there
must exist a high degree of confidence in the engineering
and economic practicability of the technology at the time
construction starts or control facilities are installed.
Asphalt Emulsion Plants
As discussed in Sections III through VII, water is used only
for cooling purposes. Since this water is a non-contact
type, it contains no pollutants, and its temperature
increases only slightly. The water is commonly pumped
through cooling towers or basins and is then discharged or
returned for reuse. The flow varies from 190 to 3,790 cu
m/day (0.05 to 1.0 mgd).
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As stated before, the only sources of contaminated water in
this subcategory is runoff caused by precipitation and/or
water collected from the wet air scrubber systems. These
wastewaters are pumped through oil skimmers to remove the
oils that are present.
The most common treatment method used in this subcategory is
to collect all runoff flow from the production area and pump
it through a gravity oil skimmer. The wastewater from the
wet air scrubber is also pumped to the oil skimmer.
Since these contaminated waters are not a function of
production but depend on climatology, BPCTCA is based on the
following wastewater flow assumptions which are derived from
information presented in Section V:
1. Production Area Size: that area in which the
oxidation towers, loading facilities, and all buildings that
house product processes are located. The average size was
determined to be approximately H hectares (10 acres).
2. Amount of Precipitation: the average daily
rainfall for the entire United States was determined to be
7.62 cm (3 in).
The limitations are based on the following removal
efficiencies:
Oil and Grease: 75-85%
When the above technology is implemented there is no
significant non-water guality impact, and the solid wastes
generated are landfilled.
The above control facilities are currently in use at 18
plants located throughout the United States as listed below:
State Number of facilities
California U
Colorado 1
Delaware 1
Indiana 1
Maryland 1
New Jersey 2
Ohio 3
Oklahoma 1
Oregon 1
Texas 3
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Based on the information contained in Sections III through
VIII and summarized above, a determination has been made
that the degree of effluent reduction attainable and the
maximum allowable discharge within this subcategory through
the application of BPCTCA are as follows:
Oil-Grease _pH
(kg/cu m) (lb/1,000 gal) (units)
30-day average 0.015 0.125 6.0-9.0
Maximum daily 0.020 0.167 6.0-9.0
Asphalt Concrete Plants
The manufacture of asphalt concrete may or may not result in
the generation of wastewater depending on the type of air
emission control equipment used. The unit operations
required were discussed in detail in Section III, the wastes
derived from the operation were characterized in Section v,
and treatment and control technology was detailed in Section
VII.
Any wastewater generated is pumped into earthen stilling
ponds where settling occurs. The resulting clear water is
recycled through the scrubber systems, and the settled
solids are dredged out and landfilled. This control method
is commonly used at over 3,100 plants in this subcategory,
according to industry estimates.
Based on the information contained in Sections III through
VIII and summarized above, a determination has been made
that the degree of effluent reduction attainable through the
application of BPCTCA is no discharge of wastewaters to
navigable waters.
Asphalt Roofing Plants
As discussed in Sections III through VII, the primary use of
water is for cooling purposes. The water may be a contact
or non-contact type. The majority of the plants in this
subcategory utilize a non-contact cooling method
supplemented by contact cooling water in the form of a
spray.
The wastewater from the non-contact cooling system is pumped
to cooling basins or cooling towers to lower its
temperature, and it is then recycled through the system. As
stated in Section V, if the plant produces its own felt,
this heated water may be used as make-up water in the white
water system. The spray water is the only known source of
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contaminated water. The flow, which varies from 11 to 657
1/min (3-171 gpm), is pumped into settling tanks or ponds.
The settled sludge is usually dredged out and landfilled.
The resulting clearwater is then recycled or discharged.
The above control facilities are currently in use at 46
plants located throughout the United States, as listed
below:
State
Alabama
California
Colorado
Florida
Georgia
Illinois
Indiana
Maryland
Massachusetts
Minnesota
New Jersey
North Carolina
Ohio
Oklahoma
Oregon
Pennsylvania
Tennessee
Texas
No« of facilities
1
7
2
1
2
4
2
2
2
2
3
1
2
2
3
1
1
8
Runoff from the asphalt storage areas and from the
oxidization tower area contain oil and grease in
concentrations that may present problems in receiving
waters. With the utilization of good housekeeping practices
these concentrations of oil and grease can be kept low.
BPCTCA for this subcategory is based on the following
production raw waste and wastewater flow assumptions, which
have been derived from information presented in Section V:
Average Production Rate: 454 kkg/day (500 ton/day)
Average Effluent Discharge Rate: 569 cu m/day (0.15
mgd)
Average Daily Suspended Solids Concentration: 184 mg/1
The limits are based on the following removal efficiencies:
Suspended Solids: 85-955J
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Based on the information contained in Sections III through
VIII and summarized above, a determination has been made
that the degree of effluent reduction attainable and the
maximum allowable discharge in this subcategory through the
application BPCTCA are as follows:
Suspended Solids pH
(kg/kkg) (lb/1,000 Ib) (units)
30-day average 0.038 0.038 6.0-9.0
Maximum daily 0.056 0.056 6.0-9.0
Linoleum and Printed Asphalt Felt Plants
As discussed in Sections III through VII, the primary use of
water in this subcategory is for clean-up operations. The
amount used varies from 8-38 cu m/day (0.002-0.01 mgd). The
wastewater is pumped to sumps, which act as settling pits,
and is then discharged. The settled material is usually
disposed of in sealed containers, because some potentially
harmful materials may be present.
BPCTCA is based on the following production raw waste and
wastewater flow assumptions, which have been derived from
information presented in Section V:
Average Production Rate: 27 kkg/day (30 ton/day)
Average Effluent Discharge Rate: 23 cu m/day (0.006
mgd)
Average Daily suspended Solids Concentration: 11 mg/1
The limits are based on the following removal efficiencies:
Suspended Solids: 85-95S
Based on the information contained in Sections III through
VIII and summarized above, a determination has been made
that the degree of effluent reduction attainable and the
maximum allowable discharge in this subcategory through the
application of BPCTCA are as follows:
Suspended Solids pH
(kg/kkg) (lb/1,000 Ib) (units)
30-day average 0.025 0.025 6.0-9.0
Maximum daily 0.038 0.038 6.0-9.0
Pretreatment Standards for Existing Sources
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Of the 4,800 plants covered under the asphalt concrete
subcategory, none is known to discharge wastewater into a
city sewer system, but approximately 200 of the 300 plants
covered in the other three subcategories use this method.
Except for oils, which have a petroleum origin, and are in
low concentrations in all but the asphalt emulsion
subcategory, the wastewaters from these four subcategories
do not contain any pollutants that are classified as
incompatible. All major contributing industries may have to
pretreat their incompatible wastes if over the specified
limit. As defined, a major contributing industry is an
industrial user of the publicly owned treatment works that:
1. has a flow of 190 cu m (50,000 gal) or more per
average work day.
2. has a flow greater than 5% of the flow carried by
the municipal system receiving the waste.
3. has in its waste, a toxic pollutant in toxic
amounts as defined in standards issued under
Section 307 (a) of the act.
4. is found by the permit issuance authority, in
connection with the issuance of an NPDES permit to
the publicly owned treatment works receiving the
waste, to have significant impact, either singly or
in combination with other contributing industries,
on that treatment works or upon the quality of
effluent from that treatment works.
If the industry does not fall into any of the above cases,
it does not need to pretreat its incompatible wastes.
These waste waters also contain large volumes of suspended
solids which consist of suspended sand and gravel and may
cause or contribute to sewer line obstruction if present in
significant concentrations.
The following pretreatment limitations are recommended for
asphalt concrete plants which discharge to publicly owned
treatment systems and whose effluent may cause sewer line
obstruction or damage:
Suspended Solids
kg/kkg or lb/1000 Ib product
30 day average 0.10
Maximum daily 0.20
These pretreatment limitations are based upon the medium
size plant with water use at 131 gal/1000 Ib product.
Concentrations for the 30 day average and maximum daily
limitations are 100 mg/liter and 200 mg/liter, respectively.
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SECTION X
BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE
Introduction
The effluent limitations which must be achieved by July 1,
1983, are to specify the degree of effluent reduction
attainable through the application of the best available
technology economically achievable (BATEA). BATEA is not
based on an average of the best performance within an
industrial category, but is determined by: 1) identifying
the very best control and treatment technology employed by a
specific plant within the industrial subcategory; or 2)
concluding that such technology is readily transferable from
one industry process to another. Consideration was also
given to:
1. The total cost of application of this control
technology in relation to the effluent reduction to
be achieved from such application.
2. Energy requirements.
3. Non-water quality environmental impact.
4. The size and age of equipment and facilities
involved.
5. The process employed,
6. Process changes.
7. The engineering aspects of the application of this
control.
BATEA also considers the availability of in-process controls
as well as control or additional end-of-pipe treatment
techniques. This control technology is the highest degree
that has been achieved or has been demonstrated to be
capable of being designed for plant scale operations up to
and including "no discharge" of pollutants.
Although economic factors are considered in this
development, the cost for this level of control is intended
to be the top-of-the-line of current technology subject to
limitations imposed by economic and engineering feasibility.
However, this control technology may be characterized by
some technical risk with respect to performance and
certainty of costs. Therefore, this control technology may
necessitate some industrially sponsored development work
prior to its application.
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Effluent Reduction Attainable Through the Application
Qf Best Available Technology Economically Achievable
Based on information contained in Sections III through VIII
of this document, a determination has been made that the
degree of effluent reduction attainable through the
application of BATEA for the four subcategories is as
follows:
Asphalt Emulsion Plants
Suspended Solids Oil 6 Grease gtt
(kg/cu m) (lb/1,000 gal) (kg/cu m) (lb/1,000 gal) (units)
30-day
average
Maximum
daily
0.015
0.023
0.125
0.188
0.010
0.015
0.083
0.125
6.0-9.0
6.0-9.0
The above figures are given in terms of volume of runoff
produced by a 7.62 cm (3-in) rainfall on an average-size
production area of 4 hectares (10 acres) during a 24-hour
period—approximately 3,028 cubic meters (0.800 mgd) .
Asphalt Concrete Plants
The limitation for this subcategory is that there will be no
discharge to navigable waters.
Asphalt Roofing Plants
Suspended Solids _pH
(kg/kkg) (lb/1,000 Ib) (units)
30-day average 0.019 0.019 6.0-9.0
Maximum daily 0.028 0.028 6.0-9.0
The above figures are given in weight per weight of product
produced. The average size plant discharges 569 cu m/day
(0.15 mgd) of wastewater, and has a daily production rate of
454 kkg (500 ton) .
74
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Linoleum and Printed Asphalt Felt Plants
Suspended Solids^
(kg/kkg) (lb/1,000 Ib) (units)
verage 0.013
daily 0.019
0.013
0.019
6.0-9.0
6.0-9.0
The above figures are given in weight per weight of product
produced. The average size plant discharges 23 cu m/day
(0.006 mgd), of wastewater and has a daily production rate
of 27 kkg (30 ton).
The limits required by the application of BATEA for the four
subcategories can be reached by using the recommended
treatment technology as stated in Section IX of this
document plus employing either additional sedimentation
facilities or increasing the capacities. There is no
evidence that this control technology will result in any
unusual air pollution or solid waste disposal problems,
either in kind or magnitude.
The above control facilities are currently being employed by
a number of plants in each subcategory throughout the United
States as listed below.
No. of facilities
State Asphalt Emulsions Asphalt Roofing
Alabama
California
Colorado
Georgia
Illinois
Indiana
Maryland
New Jersey
North Carolina
Ohio
Oklahoma
Oregon
Pennsylvania
Texas
1
1
1
1
1
1
1
1
1
3
1
2
3
1
1
1
1
2
1
1
1
6
75
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There are 3,360 plants in the asphalt concrete subcategory
that are also achieving this level.
76
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SECTION XI
NEW SOURCE PERFORMANCE STANDARDS
Standards of Performance for New sources
This level of technology is to be achieved by new sources of
wastewaters. A "new source" is defined in the Act as "any
source, the construction of which is commenced after the
publication of proposed regulations prescribing a standard
of performance"
In defining performance standards
consideration has been given to:
for
new
sources,
1.costs and energy requirements;
2.non-water quality environmental impact;
3.process changes including changes in
operating methods, and recovery of materials;
4.engineering aspects of application.
raw material
Based on the information contained in Sections III through
VIII of this document and the considerations presented
above, a determination has been made that the degree of
effluent reduction attainable through application of the New
Source Performance Standards are the same as those outlined
in Section X of this document. A summary of these limits
follows:
Asphalt Emulsion Plants
Suspended Solids
Oil & Grease
—EM—
(kg/cu m) (lb/1,000 (kg/cu m) (lb/1,000 (units)
gal) gal)
30-day
Maximum
average
daily
0
0
.015
.023
0.
0.
125
188
0.
0.
010
015
0
0
.083
.125
6.
6.
0-9.0
0-9.0
The above figures are given in terms of volume of runoff
produced by a 7.62 cm (3-in) rainfall on an average-size
production area of 4 hectares (10 acres) during a 24-hour
period—approximately 3,028 cu m (0.800 mgd).
77
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Asphalt Concrete Plants
The requirement for this subcategory is no discharge of
wastewaters to navigable waters.
Asphalt Roofing Plants
Suspended Solids pH
(kg/kkg) (lb/1,000 Ib) (units)
30-day average
Maximum daily
0.019
0.028
0.019 6.0-9.0
0.028 6.0-9.0
The above figures are given in weight per weight of product
produced. The average-size plant discharges 569 cu m/day
(0.15 mgd) of wastewater, and has an average daily
production rate of 454 kkg (500 ton) .
Linoleum and Printed Asphalt Felt Plants
Suspended Solids _p.H
(kg/kkg)(lb/1,000 Ib) (units)
30-day average 0.013 0.013 6.0-9.0
Maximum daily 0.019 0.019 6.0-9.0
The above figures are given in weight per weight of product
produced. The average-size plant discharges 23 cu m/day
(0.006 mgd) of wastewater, and has an average daily
production rate of 27 kkg (30 ton).
As stated in Section X of this document, there is no
evidence that the application of this standard will result
in any unusual air pollution or solid waste disposal
problems, either in kind or magnitude.
Pretreatment Standards for New Sources
The level of treatment required for the incompatible oils
and greases, by each of the four subcategories which
discharge into a municipal system is the same as that
required of plants discharging directly into navigable
waters as discussed in Section IX. These wastewaters may
also contain suspended solids composed of sand and gravel
78
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which may cause or contribute to sewer line obstructions.
All major contributing industries shall pretreat their
incompatible wastes to the specified limits; a major
contributing industry was defined in Section IX. If the
industry does not fall into any of these cases, it does not
need to pretreat its incompatible wastes.
Waste waters from asphalt concrete plants contain large
volumes of suspended solids which consist of suspended sand
and gravel and may cause or contribute to sewer line
obstruction if present in significant concentrations.
Pretreatment limitations for asphalt concrete plants which
will discharge effluent in significant volumes as to cause
possible sewer line obstruction to publicly owned treatment
plants are the same as those recommended for existing
sources:
Suspended Solids
kg/kkg or lb/1000 Ib product
30 day average 0.10
Maximum daily 0.20
79
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SECTION XII
ACKNOWLEDGMENTS
This report was prepared by the Environmental Protection
Agency»s Water Quality Engineering Branch of the National
Field Investigations Center, Cincinnati, Ohio under the
management of Mr. A, D. Sidio, Director. Mr. Wayne Mello,
Project Engineer and Mr. Victor F. Jelen, Chief, Water
Quality Engineering Branch made significant contributions to
the preparation of this report.
Mr. John Nardella, Project Manager, Effluent Guidelines
Division contributed to the overall coordination of this
study and assisted in the preparation of the final report.
Mr. Allen Cywin, Director Effluent Guidelines Division, Mr.
Ernst Hall, Deputy Director, Effluent Guidelines Division
and Mr. Walter J. Hunt, Chief, Effluent Guidelines
Development Branch, offered guidance and helpful
suggestions.
Members of the working Group/Steering Committee who
coordinated the internal EPA review are as follows:
Mr. Walter J. Hunt, Effluent Guidelines Division
Mr. John A. Nardella, Effluent Guidelines Division
Mr. David G. Davis, Office of Planning and Evaluation
Mr. Courtney Riordan, Office of Enforcement and
General Counsel
Mr. Wayne Mello, National Field Investigation Center
Mr. Victor F. Jelen, National Field Investigation
Center
Mr. Leon Myers, Ada Laboratory, Office of Research
and Development
Acknowledgment and appreciation is given to secretarial
staff for their efforts in the preparation of this report:
Ms. Talmedge Dunkle, NFIC
Ms. Carolyn Stumf, NFIC
Ms. Ann Covert, NFIC
Ms. Nancy Zrubek, EGD
Ms. Alice Thompson, EGD
Ms. Kay Starr, EGD
Appreciation is extended to the National Asphalt Paving
Association and the Asphalt Roofing Manufacturers
81
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Association for the valuable assistance and cooperation
given to this project.
Appreciation is extended to the following companies that
participated in the study:
Aerodyne Inc.
Arctic Roofing Inc.
Armstrong Cork Company
Aqualogic Inc.
Bird and Son Inc.
Brewer Company
Carthage Mills Inc.
Celotex Corporation
Certain-teed Products Inc.
Chexron Asphalt Company
Congoleum Industries Inc.
Del-Val Asphalt Company
Lloyd A. Fry Roofing Company
Flintkote Company
G.A.F. Inc.
Hercules Inc.
Johns-Manville Corp.
Logan Long Company
Mannington Mills Inc.
National Floor Products, Inc.
Stroud Roofing Company
Trumbull Asphalt Company
Valley Asphalt Corp.
Wapora Inc.
Warren Brothers Company
82
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SECTION XIII
References
1.Background information for proposed new source performance
standard: Asphalt Concrete Plants, Vol. 1, Main text, EPA,
Publication No. APTD-1352a.
2.Industry Profile, Annual Survey of Manufacturers 1970,
Department of Commerce, Publication No. M70(AS)-10.
3.Value of Product Shipments, Annual Survey of Manufacturers
1971, Department of Commerce, Publication No. M71(AS)-2.
4.Asphalt and Tar Roofing and Siding Products Summary for
1972, Current Industrial Reports, Department of Commerce,
Publication No. MA-29A(72)-1.
S.Kirk-Othmer, Encyclopedia of Chemical Technology, Second
Edition, John Wiley and Sons, Inc., New York.
83
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SECTION XIV
GLOSSARY
The Federal Water Pollution Control
Act Amendments of 1972.
Annual Operating Costs;Those annual costs attributed to the
manufacture of a product or operation
of equipment. They include capital
costs, depreciation, operating and
maintenance costs, and energy and
power costs.
Asphalt
A dark-brown to black cementitious
material, solid or semisolid in con-
sistency, in which the predominating
constituents are bitumens which occur
in nature as such or are obtained as
residue in petroleum refining.
Begt Available Demonstrated Control Technology {BADCT)
Treatment required for new sources as
defined by Section 306 of the Act.
(See Section XI of this report).
Best Available Technology Economically Achievable
Treatment required by July 1, 1983,
for industrial discharges to surface
(BATEA)waters as defined by Section 301 (b)
(2) (A) of the Act. (See Section X
of this report).
Best Practicable control Technology
Currently Available (BPCTCA)
Treatment required by July 1, 1977,
for industrial discharges to surface
waters as defined by Section 301 (b)
(1) (A) of the Act. (See Section IX
of this report).
Bitumen
85
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A mixture of hydrocarbons occurring
both in the native state and as
residue from petroleum distillation.
Calender
A machine equipped with rollers that
smooth the linoleum mix into a smooth
blanket or sheet.
Capital Cost
Financial charges which are computed
as the costs of capital times the
capital expenditures for pollution
control. The cost of capital is based
upon a weighted average of the separate
costs of debt and equity.
An organic compound which upon saponi-
fication yields an acid fraction and an
an alcohol fraction; in this report
restricted to those compounds which
yield glycerine as the alcohol fraction.
External Controls
Technology applied to raw waste
streams to reduce pollutant level.
Festoons
Loops or curves of saturated felts,
linoleums, or printed felts.
Flux
As used by the asphalt industries,
the residue from refining.
A device utilizing a soft wear resistant
material used to minimize leakage between
a rotating shaft and the stationary
portion of a vessel, such as a pump.
Impregnate
86
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To saturate.
|n-Plant Controls
Technology applied within the manu-
facturing process to reduce or
eliminate pollutants in the raw
wastewater.
Investment Costs
The capital expenditures required to
bring the treatment or control tech-
nology into operation. These include
the traditional expenditures, such as
design, purchase of land and materials,
site preparation, construction and
installation, plus any additional
expenses required to bring the tech-
nology into operation including
expenditures to establish necessary
solid waste disposal.
Lijpophilic
A substance having a strong attraction
for fats or other liquids.
Lithopone
A white pigment consisting of 28%
zinc sulfide and 72% barium sulfate;
used widely in paints.
New Source
Any building, structure, facility, or
installation from which there is or may
be a discharge of pollutants and whose
construction is commenced after the
publication of the proposed regulations.
pcher
Any of various colored earthy powders
consisting essentially of hydrated
ferric oxides mixed with clay, sand,
etc.
87
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Operation and ffa3.ntenance
Costs required to operate and maintain
pollution abatement equipment. They
include labor, material, insurance,
taxes, solid waste disposal, etc.
QxjLdized
The process in which air is forced
through a substance, such as asphalt
or linseed oil.
Pretreatment
Treatment applied to waste water before
it is discharged to a publicly-owned
treatment works,
Poj.ses
A unit of coefficient of viscosity,
defined as the tangential force per
unit area required to maintain unit
difference in velocity between two
parallel planes separated by 1 cm
of fluid.
Res id
Another name for residual oil, a
liquid or semiliquid product obtained
as residue from the distillation of
petroleum. It contains asphaltic
hydrocarbons.
Rotogravure
A printing process using photogravure
cylinders on a rotary press.
Standard Industrial classification
Stoyinq
A curing process in which linoleum
or printed felt floorings are hung in
ovens.
88
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Whiting
Finely ground, naturally occurring
calcium carbonate (CaCO3).
89
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CONVERSION TABLE
MULTIPLY (ENGLISH UNITS)
ENGLISH UNIT ABBREVIATION
acre ac
acre - feet ac ft
British Thermal
Unit BTU
British Thermal
Unit/pound BTU/lb
cubic feet/minute cfm
cubic feet/second cfs
cubic feet cu ft
cubic feet cu ft
cubic inches cu in
degree Fahrenheit °F
feet ft
gallon gal
gallon/minute gpm
horsepower hp
inches in
inches of mercury in Hg
pounds lb
million gallons/day mgd
mile mi
pound/square
inch (gauge) psig
square feet sq ft
square inches sq in
ton (short) ton
yard yd
by TO OBTAIN (METRIC UNITS)
CONVERSION ABBREVIATION METRIC UNIT
0.405
1233.5
0.252
ha
cu m
kg cal
0.555
0.028
1.7
0.028
28.32
16.39
0.555(°F-32)*
0.3048
3.785
0.0631
0.7457
2.54
0.03342
0.454
785
1.609
kg cal/kg
cu m/min
cu m/min
cu m
1
cu cm
°C
m
1
I/sec
kw
cm
atm
kg
cu m/day
km
(0.06805 psig +1)* atm
0.0929 sq m
6.452 sq cm
0.907 kkg
0.9144 m
hectares
cubic meters
kilogram - calories
kilogram calories/kilogram
cubic meters/minute
cubic meters/minute
cubic meters
liters
cubic centimeters
degree Centigrade
meters
liters
liters/second
killowatts
centimeters
atmospheres
kilograms
cubic meters/day
kilometer
atmospheres (absolute)
square meters
square centimeters
metric ton (1000 kilograms!
meter
* Actual conversion, not a multiplier
-------
u.r. '"• •' -
r^ic,.i i, -
230 3. Deit
Chicago, n
-------
U.S. ENVIRONMENTAL PROTECTION AGENCY (A-107)
WASHINGTON, D.C. 20460
POSTAGE AND FEES PAID
ENVIRONMENTAL PROTECTION AGENCY
EPA-335
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