&EPA
United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 2771 1
EPA-450/3-85-024
CctUber 1 985
Air
Second Review Of
New Source
Performance
Standards For
Asphalt Concrete
Plants
-------
EPA-450/385-024
Second Review of New Source
Performance Standards
for Asphalt Concrete Plants
Emissions Standards and Engineering Division
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
October 1985
-------
This report has been reviewed by the Emission Standards and Engineering Division of the Office of Air Quality Planning
and Standards, EPA, and approved for publication Mention of trade names or commercial products is not intended to
constitute endorsement or recommendation for use Copies of this report are available through the Library Services
Office (MD-35), U S Environmental Protection Agency, Research Triangle Park, North Carolina 27711; or, for a fee, from
the National Technical Information Services, 5285 Port Royal Road, Springfield Virginia 22161
-------
TERMINOLOGY SHEET
Since the development of this review document, the National Asphalt
Paving Association (NAPA) has suggested that terminology used 1n the
asphalt concrete Industry be standardized. The association suggests using
the terms "hot mix asphalt (HMA)" Instead of "asphalt concrete"; "HMA
facility" Instead of "asphalt concrete plant"; "virgin hot mix asphalt" or
"virgin HMA" Instead of "conventional mix"; and "recycled hot mix asphalt"
or "recycled HMA" Instead of "recycled asphalt pavement (RAP)."
Subsequent documents should use the terminology suggested by NAPA.
m
-------
TABLE OF CONTENTS
Page
LIST OF FIGURES viii
LIST OF TABLES ix
CHAPTER 1. EXECUTIVE SUMMARY 1-1
1.1 Regulatory History of Current Standard 1-1
1.2 Industry Trends 1-2
1.3 Control Technology 1-2
1.4 Compliance Test Data 1-3
1.5 Cost Considerations Affecting the NSPS 1-3
1.6 Enforcement Aspects 1-4
CHAPTER 2. THE ASPHALT CONCRETE INDUSTRY 2-1
2.1 Industry Characterization 2-1
2.1.1 Description of Industry 2-1
2.1.2 Asphalt Concrete Facilities
Subject to NSPS 2-3
2.1.3 Industry Growth Projections 2-3
2.2 Raw Materials 2-5
2.2.1 Aggregate 2-5
2.2.2 Asphalt Cement 2-5
2.2.3 Recycled Asphalt Pavement 2-6
2.2.4 Rejuvenating Agents 2-6
2.2.5 Sulfur 2-8
2.3 Operations of Asphalt Concrete Plants 2-8
2.3.1 Batch Plants 2-8
2.3.2 Continuous-Mix Plants 2-13
2.3.3 Drum-Mix Plants 2-13
2.3.4 Indirect Heated Plant 2-16
2.3.5 Coal as Fuel 2-19
2.4 Emissions 2-19
2.4.1 A1r Emissions 2-19
2.4.1.1 Batch Plants 2-19
2.4.1.2 Continuous Mix Plants 2-20
2.4.1.3 Drum-Mix Plants 2-20
2.4.2 Effect of Asphalt Cement Grade
on Emissions 2-20
2.5 References for Chapter 2 2-21
CHAPTER 3. CURRENT STANDARDS FOR FOR ASPHALT
CONCRETE PLANTS 3-1
3.1 Facilities Affected 3-1
3.2 Controlled Pollutants and Emission
Levels 3-2
-------
TABLE OF CONTENTS (continued)
Page
3.3 Testing and Monitoring Requirements 3-2
3.3.1 Testing Requirements 3-2
3.3.1.1 Partlculate Matter 3-2
3.3.1.2 Opacity 3-3
3.3.2 Recordkeeplng and Reporting
Requ 1 rements .- 3-3
3.4 References for Chapter 3 3-4
CHAPTER 4. EMISSION CONTROL TECHNIQUES AND TEST RESULTS 4-1
4.1 Control Devices 4-1
4.1.1 Wet Scrubbers 4-1
4.1.2 Fabric Filters 4-3
4.2 Analysis of NSPS Compliance Tests 4-4
4.3 Analysis of Site Visits 4-6
4.4 Analysis of Emission Tests Conducted by
EPA During NSPS Review 4-8
4.4.1 Partlculate Emissions
(Front-Half Catch) 4-13
.4.2 Total Organic Carbon 4-18
.4.3 Visible Emissions 4-19
.4.4 Particle Size Determinations 4-20
.4.5 Poly nuclear Aromatic Hydrocarbons 4-20
.4.6 Trace Metals 4-23
.4.7 RAP, Asphalt Cement, and Aggregate
Analysis 4-23
4.4.8 Scrubber Water Analyses 4-28
4.5 References for Chapter 4 4-34
CHAPTER 5. COST ANALYSIS 5-1
5.1 Cost Analysis of Emission Control Devices 5-1
5.2 Estimated Capital and AnnualIzed Costs of
Emission Control 5-2
5.2.1 Fabric Filters 5-2
5.2.2 Wet Scrubbers 5-2
5.3 Comparison of Estimated and Reported
Capital Cost Data 5-3
5.4 Estimated Capital and AnnualIzed Costs of
Continuous Pressure Drop and Liquid Flow
Rate Monitors 5-3
5.5 Cost Effectiveness 5-4
5.6 References for Chapter 5 5-12
CHAPTER 6. ENFORCEMENT ASPECTS 6-1
6.1 Enforcement 6-1
6.1.1 Reciprocity Waivers 6-1
vi
-------
TABLE OF CONTENTS (continued)
Page
6.1.2 Process Parameters 6-1
6.1.2.1 Production Rate 6-1
6.1.2.2 Mix Type 6-2
6.1.2.3 Fuel 6-2
6.1.3 Control Equipment 6-3
6.1.4 Blue Haze Emissions -. 6-4
6.1.5 Visible Emissions 6-5
6.2 References for Chapter 6 6-6
APPENDIX A. EMISSION SOURCE TEST DATA A-l
APPENDIX B. SUMMARY OF STATE REGULATIONS FOR ASPHALT
CONCRETE FACILITIES B-l
APPENDIX C. EMISSION MEASUREMENT METHODS C-l
vn
-------
LIST OF FIGURES
Page
Figure 2-1 Percent of total paving using recycled
asphalt pavement on State, County, and
local road projects 2-7
Figure 2-2 Operation flow chart and main parts of
typical batch plant -. 2-9
Figure 2-3 Typical tons per hour capacity at various
moisture contents 2-11
Figure 2-4 Recycling asphalt pavement 1n a batch plant 2-12
Figure 2-5 Typical drum-mix process 2-14
Figure 2-6 Indirect heated plant 2-17
Figure 4-1 Venturl scrubber control device on asphalt
concrete plant 4-2
Figure 4-2 AP distribution among NSPS compliance tests 4-7
Figure 4-3 Partlcule size distribution curves of
uncontrolled emissions collected during
recycle and conventional operation 4-25
-------
LIST OF TABLES
Table 2-1 Production Capacity Distribution for Batch,
Page
Table 2-2
Table 2-3
Table 4-1
Table 4-2
Table 4-3
Table 4-4
Table 4-5
Table 4-6
Table 4-7
Table 4-8
Table 4-9
Table 4-10
Table 4-11
Table 4-12
Table 4-13
Table 4-14
Table 4-15
Table 4-16
Table 5-1
Quantity of New Asphalt Plants Shipped
Analysis of Process Water from Indirect Heated
Compliance Test Report Summary
Control Device and RAP Utilization ,
Baghouse Design and Operating Parameters ,
Summary of Emission Data from EPA-Conducted
Tests ,
Summary of Process Parameters from EPA-Conducted
Tests ,
Summary of Polynuclear Aromatic Hydrocarbon
Emissions During Conventional Operation— Plant A....,
Summary of Polynuclear Aromatic Hydrocarbon
Summary of Trace Metal Emissions During
Conventional Operation — Plant A ,
Summary of Trace Metal Emissions During Recycle
Operation— Plant A ,
RAP and Asphalt Cement Data ,
Average Scrubber Water Analytical Measurements-
Plants A and B ,
Scrubber Water PAH Analysis— Plant A ,
Scrubber Water Trace Metal Analysis— Plant A ,
Summary of Asphalt Concrete Model Plant
Parameters ,
2-2
2-4
2-18
4-5
4-9
4-10
4-11
4-12
4-14
4-16
4-21
4-22
4-24
4-26
4-27
4-29
4-30
4-32
4-33
5-5
ix
-------
LIST OF TABLES (continued)
Table 5-2
Table 5-3
Table 5-4
Table 5-5
Estimated Capital and Annual1zed Costs of
Partleulate Emission Control Equipment....
Cost Factors Used 1n Calculating the
Annual1zed Costs
Comparison of Estimated Capital Cost of Emission
Control with Reported Capital Cost Data
Estimated Capital and Annual 1zed Costs of
Continuous Pressure Drop and Liquid Flow
Rate Monitors
Page
5-6
5-7
5-8
5-9
Table 5-6 Cost Effectiveness of Particulate Emission
Reduction
5-10
-------
1. EXECUTIVE SUMMARY
The Clean Air Act Amendments of 1977 require that the U. S.
Environmental Protection Agency (EPA) review and, if appropriate, revise
new source performance standards (NSPS) every 4 years. This report
presents information on developments that have occurred in the asphalt
concrete industry since the last review of the standards in 1979.
1.1 REGULATORY HISTORY OF CURRENT STANDARDS
The NSPS for the asphalt concrete industry were proposed on June 11,
1973, and promulgated on March 8, 1974. These standards were reviewed
in 1979, and no changes were made. The standards apply to any asphalt
concrete plant for which construction, modification, or reconstruction
commenced after June 11, 1973. An asphalt concrete plant is defined as
any facility used to manufacture asphalt concrete by heating and drying
aggregate and mixing with asphalt cements. The asphalt concrete plant
is comprised only of any combination of dryers; systems for screening,
handling, storing, and weighing hot aggregate; systems for loading,
transferring, and storing mineral filler; systems for mixing asphalt
concrete; and the loading, transfer, and storage systems associated with
emission control systems.
The standards prohibit the discharge into the atmosphere from any
affected facility exhaust gases which:
1. Contain particulate matter in excess of 90 milligrams per dry
standard cubic meter (mg/dscm) (0.04 grains per dry standard cubic foot
[gr/dscf]); and
2. Exhibit 20 percent opacity or greater.
The first review of the standard, published in 1979, recommended
that no changes be made to the particulate mass or the visible emission
1-1
-------
limits. The following sections summarize the results and conclusions of
the second review of the NSPS for asphalt concrete plants.
1.2 INDUSTRY TRENDS
The most significant development In the asphalt concrete Industry
since the 1979 review Is the Increased use of drum-mix plants and recycled
asphalt pavement (RAP). At the time of the 1979 review, only 2.5 percent
of the existing plants were drum-mix plants. In 1983, approximately
96 percent of all new asphalt concrete plants purchased In the U.S. were
drum-mix plants. The use of RAP approximately doubled between 1981 and
1983. Both of these trends are expected to continue.
The use of coal to fuel asphalt concrete plants Is a recent (since
1983) development In the U.S. Prior to 1985, most of the coal burners
were retrofit Installations at existing facilities. The use of coal for
fuel appears to be a technology that will grow rapidly, however, with as
many as 30 additional plants expected to use coal by the end of 1985.
Pre-NSPS facilities that convert to coal firing are considered modified
facilities and must perform testing to demonstrate compliance with the
NSPS. Existing NSPS plants that convert to coal firing would be required
to demonstrate compliance with the NSPS while firing coal. Because the
use of coal for fuel at asphalt concrete plants is an emerging technology,
few units have been tested and little data are presently available.
The Bureau of Census and the Construction Industry Manufacturers
Association estimate more than 800 new asphalt concrete plants have been
shipped since the 1979 review and more than 100 more will be shipped in
1985.
1.3 CONTROL TECHNOLOGY
Fabric filters or wet scrubbers (venturi scrubbers) are used to
control emissions from asphalt concrete plants. Compliance with the
particulate mass and visible emission standards has been demonstrated
using either control device. Most asphalt concrete plants utilize
cyclones to recover particulate matter from the exhaust gas stream for
product recovery and to reduce the particulate load to the emission
control device. The recovered material is recycled to the process as
1-2
-------
filler; thus, these knockout boxes or cyclones are considered process
equipment rather than emission control devices.
A detailed discussion of the control technology used in the asphalt
concrete industry is presented in Chapter 4.
1.4 COMPLIANCE TEST DATA
During the present review of the asphalt concrete NSPS, 369 compliance
test reports were collected from State agencies and reviewed. Approxi-
mately half of the plants operated at less than 80 percent of their
design capacity during testing. Of the reports presenting numerical
test results, 13 percent reported particulate emissions greater than the
NSPS limit of 90 mg/dscm (0.04 gr/dscf). The majority of these
non-complying plants were scrubber-controlled drum-mix plants. These
reports also revealed that 82 percent of the scrubber-controlled plants
were operated with a pressure drop (AP) across the scrubber of less than
5 kilopascals (kPa) (20 inches of water column [in. w.c.]). Of the 369
reports collected during this review, 89 reports presented either complete
or summarized opacity data. Of these 89 reports, 7 had 6-minute averages
greater than 20 percent. Three of these seven plants were producing
conventional mix. These three plants also reported particulate emissions
greater than 90 mg/dscm (0.04 gr/dscf). The remaining four plants with
opacity greater than 20 percent were utilizing recycled asphalt pavement
(RAP) during testing. Of these four plants, one had particulate emissions
greater than 90 mg/dscm (0.04 gr/dscf), two had particulate emissions
less than 90 mg/dscm (0.04 gr/dscf), and one did not report the particulate
emission level. A detailed analysis of these compliance test reports is
presented in Section 4.2.
1.5 COST CONSIDERATIONS AFFECTING THE NSPS
To estimate the cost impacts of the NSPS, model facility descriptions
were developed based on information from the industry. The capital and
annualized costs for the control system for each model plant were estimated
using guidelines in Capital and Operating Costs of Selected Air Pollution
Control Systems (CARD, Inc.) and information supplied by industry. Costs
were updated to September 1984 dollars using the Chemical Engineering
journal plant cost index. The cost effectiveness of fabric filter and
wet scrubber control devices on each of three model plant sizes for
1-3
-------
seasonal operation (1,000 h/yr) and year-round operation (1,500 h/yr)
was calculated. For seasonal operation, the cost effectiveness of
controlling emissions from model plants with a fabric filter control
device ranges from $130 to $253 per Mg ($118 to $230 per ton). With a
wet scrubber control device, the cost effectiveness of emission control
ranges from $108 to $213 per Mg ($99 to $194 per ton). For year-round
operation, the cost effectiveness of control for fabric filters ranges
from $89 to $183 per Mg ($81 to $168 per ton). For wet scrubbers, the
cost effectiveness of control ranges from $84 to $166 per Mg ($76 to
$151 per ton).
1.6 ENFORCEMENT ASPECTS
Chapter 6 discusses air pollution control agency personnel concerns
regarding conditions that should exist during NSPS performance tests
including process parameters (production rate, mix type, fuel used, and
product temperature), control equipment (AP across scrubbers or fabric
filter, water quality and pond size for scrubbers), and visible emissions.
1-4
-------
2. THE ASPHALT CONCRETE INDUSTRY
2.1 INDUSTRY CHARACTERIZATION
2.1.1 Description of Industry
Companies that produce asphalt concrete are Included in Standard
Industrial Classification (SIC) Code 2951, "Paving Mixtures and Blocks."1
In the production of asphalt concrete, aggregate, which is composed of
gravel, sand, and mineral filler, is heated to eliminate moisture and
then mixed with hot asphalt cement. The resulting hot mixture is pliable
and able to be compacted and smoothed. When it cools and hardens,
asphalt concrete provides a waterproof and durable pavement for roads,
driveways, parking lots, and runways.
There are approximately 2,150 companies operating an estimated
4,500 asphalt concrete plants in the United States.2 Approximately
40 percent of these companies operate only a single plant.2 Because
plants must be located near the job site, plants are concentrated in
areas where the highway and road network is concentrated. Approximately
14 percent of asphalt concrete companies diversify their operations by
producing portland cement (an asphalt concrete substitute), while
49 percent quarry aggregate, and 88 percent lay hot mix asphalt
concrete.2,3
The three types of asphalt concrete plants in use are batch-mix,
continuous-mix, and drum-mix. Batch-mix and continuous-mix plants
separate the aggregate drying process from the mixing of aggregate with
asphalt cement. Drum-mix plants combine these two processes. Plant
production capacities range from 36 to 544 megagrams (Mg) (40 to 600 tons)
of hot mix per hour.2,3 The production capacity distribution for the
three types of asphalt concrete plants is presented in Table 2-1.2,3
Over 80 percent of all asphalt concrete plants are mobile.2
2-1
-------
TABLE 2-1. PRODUCTION CAPACITY DISTRIBUTION FOR BATCH, DRUM-MIX,
AND CONTINUOUS PLANTS2,3
Percentage
of plants
Production range, within produc-
Type of plant
Batch plants
Mg/h (tons/h)
Under 136 (Under 150)
136-272 (150-300)
273-363 (301-400)
Over 363 (Over 400)
tion range
25
63
11
1
iffo
Drum-mix plants Under 136 (Under 150) 15
136-272 (150-300) 52
273-363 (301-400) 26
Over 363 (Over 400) 7
100
Continuous mix plants Under 136 (Under 150) 43
136-272 (150-300) 21
273-363 (301-400) 19
Over 363 (Over 400) 17
TUB
2-2
-------
2.1.2 Asphalt Concrete Facilities Subject to NSPS
The new source performance standards (NSPS) for asphalt concrete
plants apply to facilities for which construction, modification, or
reconstruction commenced (as defined under 40 CFR 60.2) after June 11,
1973.4,5 Due to the large number of affected facilities in the asphalt
concrete industry, a complete list of affected facilities is beyond the
scope of this review. In addition, any list of affected facilities
would be of limited value due to the constantly changing number of
plants and the mobile nature of the asphalt industry. Instead, an
estimate of the number of new facilities has been made.
The total number of new asphalt plants shipped each year between
July 1973 and December 1983, as reported by the Bureau of the Census, is
presented in Table 2-2.6 An estimated 1,437 new plants were shipped in
the U.S. between July 1973 and December 1983. The Construction Industry
Manufacturers Association estimates a 14.8 percent increase in new asphalt
concrete plant sales for 1984 over 1983 and predicts a 13.4 percent
increase in sales for 1985 over 1984.7 Applying these increases
to the estimated 81 new plants shipped in 1983 yields an estimate of
93 new plants in 1984 and 105 new plants in 1985. Therefore, by the end
of 1985, an estimated 1,635 new plants will have been shipped since July
1973.
2.1.3. Industry Growth Projections
The Interstate Construction Estimate (ICE) reports that 350 and
372 million Mg (386 and 410 million tons) of asphalt concrete were
produced in 1983 and 1984, respectively.8 It is predicted that
production for 1985 will remain about 363 million Mg (400 million tons)
and that production for 1986 will increase significantly assuming an
increase in funding for highways.8
Batch-mix and drum-mix plants comprise the majority of existing
asphalt concrete plants, followed by a few remaining continuous-mix
plants.2,3 Continuous-mix plants are no longer sold. In 1983,
approximately 96 percent of all new asphalt concrete plants purchased in
the United States were drum-mix plants.9 As discussed in Section 2.1.2,
an increase in sales of new asphalt concrete plants of 14.8 percent is
expected for 1984 over 1983 and an increase of 13.4 percent is predicted
for 1985 over 1984.7
2-3
-------
TABLE 2-2. QUANTITY OF NEW ASPHALT PLANTS SHIPPED6
Year
1983
1982
1981
1980
1979
1978
1977
1976
1975
1974
Total quantity
shipped
114
171
307
241
190
184
198
131
132
194
Quantity exported3
33b
50C
91
82d
44e
41
33
35f
34g
549
Quantity shipped
in U.S. only
81b
121C
216
159d
146e
143
165
96f
98g
144g
last half
of 1973 92 24°
Total 1,954 517 1,437
aOata from the Bureau of the Census on exports are reported for 1977, 1978,
and 1981; partial data or no data were available for the remaining years
because some export information is proprietary. Therefore, exports in
.remaining years have been estimated.
"Based on 1981 and 1982 total export rate of 29 percent.
jBased on total export rate of 29 pecent for first 3 quarters of 1982.
Based on total export rate for last 3 quarters of 1980 and on export rate
of plants over 180 tph in first quarter of 1980 (34 percent).
fBased on total export rate of 23 percent for last 3 quarters of 1979.
Based on total export rate of 27 percent for last quarter of 1976.
9Based on average export rate of 26 percent for 1976 through 1983.
2-4
-------
2.2 RAW MATERIALS
2.2.1 Aggregate
Aggregate consists of any hard, inert mineral material mixed with a
binding material in the production of asphalt concrete.10 Aggregate
typically comprises between 90 and 95 percent by weight of the asphalt
concrete mixture.10 Since aggregate provides most of the load-bearing
properties of a pavement, the performance of the pavement depends on
selection of the proper aggregate.10
2.2.2 Asphalt Cement
Asphalt cement binds the aggregate, prevents moisture from
penetrating the aggregate, and acts as a cushioning agent. It typically
comprises 4 to 6 percent by weight of the asphalt concrete mixture.11
Asphalt cement is the residue from the distillation of crude
petroleum. Asphalt cement is classifed into "grades" under one of three
systems. The most commonly used system classifies asphalt cement based
on its viscosity at 60°C (140°F).12 The more viscous the asphalt cement,
the higher its numerical rating. An asphalt cement of grade AC-40 is
considered a "hard" asphalt (i.e., a viscosity of 4,000 grams per
centimeter per second [g/cm-s] [poises]), while an asphalt cement of
grade AC-2.5 is considered a "soft" asphalt (i.e., a viscosity of
250 g/cm-s [poises]).12 Several western States use a second grading
system that measures viscosity of the asphalt cement after a standard
simulated aging period.13 This simulated aging period consists of
exposure to a temperature of 163°C (325°F) for 5 hours.13,14 Viscosity
is measured at 60°C (140°F), with grades ranging from AR-1000 for a
"soft" asphalt cement (1,000 g/cm-s [poises]) to AR-16000 for a "hard"
asphalt cement (16,000 g/cm-s [poises]). A third grading system is
based on the "penetration" allowed by the asphalt cement.14 Grade
designation 40 to 50 means that a needle with a weight attached will
penetrate the asphalt cement between 40 and 50 tenths of a millimeter
under standard test conditions.12 The "hard" asphalt cements have
penetration ratings of 40 to 50 while the "soft" grades have penetration
ratings of 200 to 300.12
2-5
-------
The asphalt cement grade selected for asphalt concrete mixes
depends on the type of pavement, climate, and type and amount of traffic
expected.15 Generally, asphalt pavement bearing heavy traffic in warm
climates would require a harder asphalt cement than pavement subject to
either light traffic or cold climate conditions.15
2.2.3 Recycled Asphalt Pavement
Recycled asphalt pavement (RAP) is pavement material that has been
removed from a roadway for use in new asphalt concrete pavement.
Recycled asphalt pavement is used by a growing number of companies in
their asphalt concrete mixtures. The Surface Transportation Assistance
Act of 1982 encourages recycling by providing a 5 percent increase in
Federal funds to State agencies that recycle asphalt concrete pavement.
Figure 2-1 shows how the use of RAP in government paving contracts has
increased since 1981. Rarely does the RAP comprise more than 60 percent
by weight of the asphalt concrete mixture. Twenty-five percent RAP
mixtures are typical in batch plants while 40 to 50 percent RAP mixtures
are typical in drum-mix plants.16-18
Two methods are used to remove the old asphalt concrete pavement
that is to be recycled. In one method, a milling machine planes off 5
to 10 cm (2 to 4 in.) of pavement with each pass it makes over the road.
These machines have rotating cylinders with metal teeth that grind up
the pavement leaving a rough but usable temporary surface for traffic.
The ground-up pavement can be used immediately in the production of new
asphalt concrete. The other method involves ripping up large chunks of
pavement with heavy construction equipment. These chunks are
transported to crushing machines that reduce the material to usable size
for the production of asphalt concrete.18 The road is typically closed
to traffic if this process is used.
2.2.4 Rejuvenating Agents
Rejuvenating agents are sometimes used in RAP mixes to bring the
weathered and aged asphalt cement in the RAP up to the specifications of
the new pavement. Usually, a soft asphalt cement, a specially prepared
high viscosity oil, or a hard asphalt cement blended with a low
viscosity oil are used as rejuvenating agents. The amount of
rejuvenating agent added depends on the properties of the RAP and on the
2-6
-------
_ 30
i
3
20
«9
10
STATE: —
COUNTY: ~
LOCAL: "'
PROJECTED: —
1981
1982 1983
YEAR
1987
Figure 2-1. Percent of total paving using recycled asphalt pavement
on State, county, and local road projects.16
2-7
-------
specifications for the asphalt concrete product. These specifications
are usually stipulated by the applicable State department of transporta-
tion. A State may permit the use of a rejuvenating agent at the
contractor's discretion or may require the use of a rejuvenating agent.
2.2.5 Sulfur
Sulfur has been used on an experimental basis as a substitute for a
portion of the asphalt cement in asphalt concrete mixes. Tests show
that the asphalt cement/sulfur combination is better able to bind with
aggregate than is asphalt cement alone.19 Also, asphalt concrete pave-
ments containing the asphalt cement/sulfur combination appear to be
stronger and less susceptible to temperature changes than those
containing asphalt cement alone.19
The use of sulfur is not competitive with asphalt cement in asphalt
concrete mixes for several reasons, including environmental questions,
worker objections (odor), and corrosion, all of which result from
emissions of hydrogen sulfide (H2S), sulfur dioxide (S02), and elemental
sulfur (S). In addition, sulfur is almost twice as dense as asphalt
cement. Consequently, to make the use of sulfur economically feasible,
the cost of sulfur must be less than half the cost of asphalt cement.20
The resolution of these issues will determine the future use of sulfur
in the production of asphalt concrete.
2.3 OPERATIONS OF ASPHALT CONCRETE PLANTS
2.3.1 Batch Plants
Figure 2-2 is a schematic of a typical batch plant operation.
Aggregate of various sizes is stockpiled at the plant for easy access.
The moisture content of the stockpiled aggregate usually ranges from 3
to 5 percent.23 (Because aggregate piles are typically not covered, the
moisture content can be higher after rainfall.) The moisture content of
RAP is usually from 2 to 3 percent.24
The different sizes of aggregate are typically transported by
front-end loader to separate cold feed bins and metered onto a feeder
conveyor belt through gates at the bottom of the bins. The aggregate is
screened before it is fed to the dryer to keep oversized material out of
the mix.
2-8
-------
THE BASIC PROCESS IS SHOWN BELOU:
HOT
ASPHALT
STORAGE
•*
MEASURING
MINERAL
FILLER
STORAGE
•>
MEASURING
1. Cold storage bins
2. Cold elevator
3. Dryer
4. Dust collector
5. Hot elevator
6. Screening unit
7. Hot bins
8. Weigh box
9. Pugmill
10. Baghouse
Figure 2-2. Operation flow chart and main parts of
typical batch plant.21,22
2-9
-------
The screened aggregate is fed to a rotating dryer with a burner at
its lower (discharge) end that is fired with fuel oil, natural gas, or
propane. The dryer removes moisture from the aggregate and heats the
aggregate to the proper mix temperature. Inside the dryer are longitu-
dinal flights (metal slats) that lift and tumble the aggregate, causing
a curtain (veil) of material to be exposed to the heated gas stream.
This curtain of material provides greater heat transfer to the aggregate
than would occur if the aggregate tumbled along the bottom of the drum
towards the discharge end. Typical aggregate temperature at the
discharge end of the dryer is about 149°C (300°F). The amount of
aggregate that a dryer can heat depends on the size of the drum, the
size of the burner, and the moisture content of the aggregate. As the
amount of moisture to be removed from the aggregate increases, the
effective production capacity of the dryer decreases. Figure 2-3 shows
a typical relationship between effective dryer production capacity and
amount of moisture to be removed from the aggregate. As the figure
demonstrates, a 2 percent increase in moisture content in the aggregate
can decrease dryer production capacity by 25.3 percent.
Vibrating screens segregate the heated aggregate into bins
according to size. A weigh hopper meters the desired amount of the
various sizes of aggregate into a pugmill mixer. The pugmill typically
mixes the aggregate for approximately 15 seconds before hot asphalt
cement from a heated tank is sprayed into the pugmill.26 The pugmill
thoroughly mixes the aggregate and hot asphalt cement for 25 to 60 seconds.26
The finished asphalt concrete is either directly loaded into trucks or
held in insulated and/or heated storage silos. Depending on the production
specifications, the temperature of the asphalt concrete mix can range
from 107° to 177°C (225° to 350°F) at the end of the production process.27
When mix containing RAP is produced, the aggregate is superheated
(compared to conventional operation) to about 315°C (600°F) to ensure
sufficient heat transfer to the RAP when it is mixed with the virgin
materials.28 As shown in Figure 2-4, RAP may be added either to the
pugmill mixer or at the discharge end of the dryer. Rarely is more than
30 percent RAP used in batch plants for the production of asphalt
concrete.18
2-10
-------
TPH
300
250
200
150
100
50
(With a specified dryer operating at constant
heat consumption)
"1"
25.3% decrease^
,i
!••••
Moisture
increase
0 123456 789 10 11 12
MOISTURE REMOVED (%)
Figure 2-3. Typical tons per hour capacity
at various moisture contents.25
2-11
-------
COLD FEED
NEW
AGG. SAND
ffiZ
TO
EMISSIONS
CONTROL
SYSTEM
AGGREGATE
DRYER
SCREENS
SCALES
PUG MILL
RAP
(A) Standard batch plant with RAP added to superheated aggregate at the
pug mill.
SCREENS
SCALES
PUG MILL
COLD FEED
NEW
AGG. SAND
TO
EMISSIONS
CONTROL
SYSTEM
AGGREGATE
DRYER
AC MOD
oo
(B) Standard batch plant with RAP added to superheated aggregate at
dryer discharge.
Figure 2-4. Recycling asphalt pavement in a batch plant.29
2-12
-------
Many batch plants have some form of mechanical dust collector that
recovers particulate matter generated during the drying of the aggregate.
The recovered fines are recycled to the production process, thus decreasing
aggregate costs for the plant.
2.3.2 Continuous-Mix Plants
Continuous-mix plants are similar to batch plants. Continuous-mix
plants have smaller hot bins (for holding the heated aggregate) than do
batch plants. Little surge capacity is required of these bins because
the aggregate is continuously metered and transported to the mixer inlet
by a conveyor belt. Asphalt cement is continuously added to the aggregate
at the inlet of the mixer. The aggregate and asphalt cement are mixed
by the action of rotating paddles while being conveyed through the
mixer. An adjustable dam at the outlet end of the mixer regulates the
mixing time and also provides some surge capacity. The finished mix is
transported by a conveyor belt to either a storage silo or surge bin.
2.3.3 Drum-Mix Plants
Figure 2-5 depicts a typical drum-mix plant equipped for production
using only virgin raw materials. Drum-mix plants dry the aggregate and
mix it with the asphalt cement in the same drum, eliminating the need
for the extra conveyor belt, hot bins and screens, weigh hopper, and
pugmill. Although the drum of a drum-mix plant is much like the dryer
of a batch plant, the burner is at the aggregate feed end rather than at
the aggregate discharge end. The veil of aggregate is heated as it
flows with the heated gas stream instead of countercurrent to the gas
stream as in a batch plant.
The burner in a drum-mix plant emits a much bushier flame than does
the burner in a batch plant. The bushier flame is designed to provide
earlier and greater exposure of the virgin aggregate to the heat of the
flame. This design also protects the asphalt cement, which is injected
approximately two thirds of the way down the length of the drum, away
from the direct heat of the flame. Drum-mix plants typically have more
flights in their drums than do batch dryers to increase veiling of the
aggregate and to improve heat transfer.31
2-13
-------
Particular
Laden Qaa
••
Particulate
Collection
Devlce(a)
J
Cleaned
Gao y
Stack
Aggregate
Burner
Burner Fuel
IT TI
Figure 2-5. Typical drum-mix process.30
-------
The asphalt cement, which is usually injected from a pipe inserted
from the discharge end of the rotating drum, coats the aggregate. The
temperature of the mix as it leaves the drum usually ranges from 107° to
177°C (225° to 350°F).27 The hot asphalt concrete is transported by
conveyor to a surge bin or to an insulated, and possibly heated, storage
silo for truck load-out. Like batch plants, drum-mix plants have
mechanical dust control devices that capture material to be recycled to
the process. In addition, the fine dust captured by the baghouse is
returned to the process.
The first recycle plants introduced the RAP with the virgin
aggregate at the burner end of the drum. This often caused "blue haze"
as volatile compounds in the RAP burned off when RAP came in contact
with the burner flame.18,30 In attempts to prevent the generation of
blue haze, manufactures have experimented with several modifications of
the technology for introducing RAP to the'drum-dryer. In one modifica-
tion, water is sprayed on the RAP and aggregate immediately before it
enters the burner end of the drum. The water raises the moisture
content of the aggregate and RAP from about 5 percent to 7 or 8 percent.32
Another modification is to place a heat shield around the burner to
shield the RAP from direct contact with the flame. However, this method
restricts the flow of the burner gas, which increases the gas velocity
and turbulence and results in higher dust carryover than is experienced
without the shield.18 A third modification incorporates a separate drum
inside of the mixing drum to shield the RAP from the hot gas stream.
Virgin material is heated directly in the inner drum while the RAP is
introduced between the two drums to shield it from the direct flame.
The RAP is heated indirectly by contact with the inner drum before being
mixed with the superheated virgin aggregate at the discharge point of
the inner drum.18,33 This method reduces the capacity of the drum-mix
plant because the presence of the inner drum reduces the effective
volume of the outer drum.
Currently in new drum-mix plants, the RAP is introduced through a
collar midway down the drum and is dried by both the superheated aggregate
and by the gas stream. The veil of virgin aggregate created by the
2-15
-------
flights in the drum keeps the high heat of the flame from reaching the
RAP. Two vendors have attempted to improve on this approach by also
expanding the drum diameter at the burner end to allow a shorter, bushier
flame and to obtain more efficient heat transfer from the burner flame
to the virgin aggregate.34
One major advantage of drum mix plants is that they can produce
material containing higher percentages of RAP than batch plants can
produce. With the greater veiling of aggregate, drum-mix plants are
more efficient than batch plants at transferring heat and achieving
proper mixing of RAP and virgin materials.
2.3.4 Indirect Heated Plant
A potential new commercial production process for asphalt concrete
involves indirect heating of the aggregate and asphalt cement in a
mixer.35 Figure 2-6 depicts this production process.
In this process, asphalt cement and preheated aggregate are intro-
duced through air-locks into a heated, sealed mixing unit. Synthetic
heat transfer fluids are heated to 316° to 343°C (600° to 650°F) by a
fuel efficient diesel- or gas-fired burner.35 These synthetic fluids
heat the mixing unit chamber to approximately 149°C (300°F).35 Steam
from the moisture driven off from the aggregate is piped to the cold
feed bins to preheat the virgin aggregate. This preheating of the
aggregate decreases energy costs for drying. The product asphalt
concrete mix is transported by an enclosed conveyor from the mixing unit
to a storage silo. Because this process is sealed, there are no process
air emissions. The steam from the mixing unit condenses as it preheats
the cold feed bins. The results of tests on this condensed water are
presented in Table 2-3. The only other process emissions are the gases
from the heater unit. No air emission tests have been performed on the
heater units at this type of plant.
The indirect heated process has been successfully demonstrated with
a pi lot-scale plant capable of producing 14 to 18 megagrams per hour
(Mg/h) (15 to 20 tons per hour [tons/h]) of asphalt concrete.38 Stationary
and portable indirect heated plants have been designed with production
capacities ranging from 45 to 204 Mg/h (50 to 225 tons/h), and commercial
plants of 181 to 272 Mg/h (200 to 300 tons/h) production capacity are
expected by 1986.37,38
2-16
-------
ro
i
COLD FEED HEAT RECOVERY
BINS DIN STEAM HEATER
EXPANSION
TANK
SURGE SILO
CONDENSATE
FEED CONVEYOR
DRAG DLADE
CONVEYOR
ASPHALT
SUPPLY
NIXING UNIT
Figure 2-6. Indirect heated plant.35-37
-------
TABLE 2-3. ANALYSIS OF PROCESS WATER FROM
INDIRECT HEATED ASPHALT CONCRETE PLANTS36
Test,
mg/£
Total dissolved solids 28
Phenolphthalein alkalinity 0
Total alkalinity as CaC03 10
Carbonate alkalinity 0
Chloride as Cl 1.7
Sulfate as S04 3.5
Total hardness as CaC03 10
Magnesium as Mg 0.5
Iron as Fe 1.1
Manganese as Mn 0.05
Turbidity, NTU 11
2-18
-------
2.3.5 Coal as Fuel
A limited number of plants have experimented with coal as a fuel.
The majority of coal-fired asphalt concrete plants use dry pulverized
coal, although one manufacturer produces a wet coal slurry system.39-42
This slurry consists of 70 percent pulverized coal, 29 percent water,
and 1 percent additive to keep the coal in suspension.41
Because the use of coal in asphalt concrete plants is a very recent
(since 1983) development in the U.S., there are few emission test reports
for plants utilizing coal.40,42 The use of coal for fuel appears to be
a technology that may grow rapidly, however, with as many as 30 additional
plants expected to use coal by the end of 1985.40
2.4 EMISSIONS
2.4.1 Air Emissions
2.4.1.1 Batch Plants. The air emissions from the dryer include
sulfur oxides, nitrogen oxides, hydrocarbons, particulate matter,
aldehydes, carbon monoxide, and polycyclic organic material (POM).43
The uncontrolled particulate emission level from batch plants averages
22.5 kilograms (kg) per Mg (45 pounds [Ib] per ton) of asphalt concrete
produced.43 No uncontrolled emission data are available for gaseous
emissions from batch plant dryers.
Fugitive emissions not related to the production process include
dust from trucks carrying aggregate or asphalt concrete, aggregate blown
from stockpiles or from raw materials being transported to the dryer,
and emissions from openings in the storage silo or surge bin. The
potential uncontrolled fugitive particulate emission level from batch
plants is 0.163 kg per Mg (0.326 Ib per ton) of asphalt concrete
produced.44,45
"Blue haze" emission have been reported when RAP and virgin
materials are mixed.46 These emissions may occur when the RAP material
is heated to a temperature that exceeds its smoke point. In addition,
some batch plant operators have found that their exhaust gas handling
systems are undersized to handle the large amount of exhaust gas
generated when the moisture in the RAP turns to steam.
2-19
-------
2.4.1.2 Continuous-Mix Plants. The uncontrolled participate
emission level from continuous-mix plants is approximately the same as
that from batch plants.18
2.4.1.3 Drum-Mix Plant. The uncontrolled particulate emission
level from drum-mix plants averages about 2.45 kg per Mg (4.9 Ib per
ton) of asphalt concrete produced.47 Production levels, aggregate
properties, and gas stream velocity affect particulate emission levels
from drum-mix plants in the same way they affect those from batch
plants.47 As measured by EPA Reference Method 5E, uncontrolled
condensible hydrocarbon emissions range from about 0.006 to 0.14 kg
(0.012 to 0.27 Ib) of carbon per Mg (ton) of asphalt concrete.48,49
Production levels and operating temperatures may influence these hydro-
carbon emissions.50
The fugitive emissions from drum mix plants are similar in type,
source, and amount to fugitive emissions from batch plants with the
exception of fugitive emissions associated'with the mixing units at
batch and drum-mix plants.
2.4.2 Effect of Asphalt Cement Grade on Emissions
The way in which various grades of asphalt cement affect emissions
from batch and drum-mix plants is not known. Due to a probable increase
in the amount of light hydrocarbons in soft asphalt cements, higher
total organic carbon (TOC) emissions are expected when a soft asphalt
cement, such as AC-2.5, is used than when a hard asphalt cement, such as
AC-20, is used. Although asphalt cements are graded by viscosity and
tested for flash point, ductility, specific gravity, softening point,
and weight loss and change in penetration upon heating, no analyses of
the chemical constituents of various asphalt cements are routinely made
as part of quality control for the production process. Laboratory test
data indicate that two asphalt cements distilled from two different
crude oils can receive the same grade designation and yet have different
chemical constituents. The lack of sophisticated equipment and
technical expertise in existing asphalt testing laboratories precludes
the chemical analysis of asphalt cements. Also, the relationship
between the chemical constituents of an asphalt cement and its behavior
in the pavement is uncertain, further discouraging chemical analysis of
asphalt cement.51
2-20
-------
2.5 REFERENCES FOR CHAPTER 2
1. Office of Management and Budget. Standard Industrial Classification
Manual. 1972. United States Government Printing Office: Washington,
D.C. p. 127.
2. Telecon. Maul, M., MRI, with Kloiber, F., National Asphalt Pavement
Association. October 7, 1983. Production facts and figures for
asphalt concrete industry, 1981-1982.
3. Letter and attachments from Kloiber, F., National Asphalt Pavement
Association, to Kinsey, J., MRI. May 3, 1982. Production facts
and figures for asphalt concrete industry, 1979-1981.
4. Environmental Protection Agency. Inspection Manual for Enforcement
of New Source Performance Standards, Asphalt Concrete Plants. EPA
340/1-76-003. Washington, D.C. March 1976. p. 3.
5. Environmental Protection Agency. Code of Federal Regulations.
Title 40, Chapter I, Part 60. Washington, D.C. Office of the
Federal Register. July 1, 1982.
6. U.S. Department of Commerce, Bureau of the Census. Current Industrial
Reports, Construction Machinery. MA 35D(74)-1 through MA 35D(83)-1,
1974 through 1983.
7. Material from Witas, D. A., Construction Industry Manufacturers
Association, to Butler, J. R., MRI. March 15, 1985. Bureau of
Census and CIMA forecast of 1984 and 1985 machine shipments.
8. Telecon. Butler, J., MRI, with Kloiber, F., National Asphalt
Pavement Association. November 20, 1984. Production facts and
figures for asphalt concrete industry.
9. Telecon. Maul, M., MRI, with Mize, G., ASTEC Industries, Inc.
October 10, 1983. Profile of asphalt concrete industry.
10. The Asphalt Institute. Principles of Construction of Hot-Mix
Asphalt Pavements. Manual Series No. 22, College Park, Maryland.
January 1983. p. 168.
11. The Asphalt Institute. Mix Design Methods for Asphalt Concrete.
College Park, Maryland. March 1979. pp. 27, 59.
12. The Asphalt Institute. Paving Asphalt. Educational Series No. 8.
College Park, Maryland. January 1980. pp. 2-3.
13. Reference 10, p. 15.
14. The Asphalt Institute. Asphalt as Material Information Series
No. 93. College Park, Maryland. July 1975. p. 7-8.
2-21
-------
15. Barber-Greene Company. Bituminous Construction Handbook. Aurora,
Illinois. 1979. pp. 39-40.
16. Letters and attachments from Hoyt, P., Asphalt Recyling and Reclaiming
Association, to Maul, M., MRI. November 4, 1983. Information on
the Asphalt Recycling and Reclaiming Association and a 1982 survey
of governments concerning use of recycled asphalt pavement.
17. Trip report. Terry, W., MRI, to Telander, J., EPA:ISB. October 31,
1983. Report of visit to CMI Corp., Oklahoma City, Oklahoma.
18. Kinsey, J. S. Asphalt Concrete Industry—Source Category Report.
U. S. Environmental Protection Agency. Research Triangle Park,
North Carolina. February 28, 1983. pp. 15-18.
19. Fronun, H. J., 0. C. Bean, and L. Miller. Sulphur-Asphalt Pavements
Performance and Recycling. Proceedings of the Association of
Asphalt Paving Technologists, Vol. 49. 1980. p. 98.
20. Mize, G. Safe Paving with Sulfur. Information Series 81. National
Asphalt Pavement Association. Riverdale, Maryland. 1981. p. 1.
21. Reference 10, p. 139.
22. Reference 15, pp. 170-171.
23. Reference 18, pp. 5.
24. Trip report. Terry, W., MRI, to Telander, J., EPA:ISB. August 28,
1984. Report of visit to ASTEC Industries, Inc., Chattanooga,
Tennessee.
25. Reference 15, p. 154.
26. Reference 18, p. 7.
27. Reference 15, p. 239.
28. Scherocman, J. A. (Barber-Greene Company). Producing Recycled
Asphalt Concrete Mixtures in Batch and Drum-Mix Plants. North
Carolina Asphalt Pavement Recycling Seminar, McKimmon Center:
Raleigh. February 9-10, 1983.
29. Reference 18, p. 20.
30. Beggs, T. W. (JACA Corp.). Emission of Volatile Organic Compounds
from Drum-Mix Asphalt Plants. Prepared for U. S. Environmental
Protection Agency. Cincinnati, Ohio. EPA-600/2-81-026. February 1981.
pp. 2-5.
31. Reference 28, p. 7-10.
2-22
-------
32. Trip report. Shular, J., MRI, to Telander, J., EPA:ISB. August 28,
1984. Report of visit to Ajax Materials Corp., Detroit, Michigan.
33. The Asphalt Institute. Asphalt Hot-Mix Recycling. Manual Series
No. 20. College Park, Maryland. August 1981. p. 27, 30.
34. Trip report. Terry, W., MRI, to Telander, J., EPA:ISB. October 31,
1983. Report of visit to CMI Corp., Oklahoma City, Oklahoma.
35. Letter and brochure from Musil, J., Iowa Manufacturing Company to
Telander, J., EPArlSB. November 4, 1983. Costs and benefits of
indirect heating asphalt concrete plant.
36. Letter and attachment from Bracegirdle, P., Mix Design Methods,
Inc., to Telander, J., EPArlSB. November 17, 1983. Indirect
heated plant.
37. Letter and attachment from Bracegirdle, P., MDM Industries, Inc.,
to J. Butler, MRI. August 20, 1984. Update on indirect heated
plant.
38. Telecon. Butler, J., MRI, with Bracegirdle, P., MDM Industries,
Inc. January 16, 1985.
39. Letter and attachments from Sprouse, S. M., Astec Industries, Inc.
March 26, 1985. Emission test report and product literature.
40. Telecon, Butler, J., MRI, to Brock, D., Astec Industries. March 21,
1985. Discussion of coal as a fuel in asphalt concrete plants.
41. Literature from Clements, J., Standard Havens to Bulter, J., MRI.
March 15, 1985. Product literature and test results.
42. Telecon, Butler, J. MRI, to Clements, J., Standard Havens. March 19,
1985. Discussion of coal as a fuel in asphalt concrete plants.
43. Kahn, Z. S., and T. W. Hughes, (Monsanto Research Corp.). Source
Assessment Asphalt Hot Mix. Prepared for U. S. Environmental
Protection Agency. Cincinnati, Ohio. EPA-600/2-77-107n.
December 1977. pp. 45-52.
44. Evaluation of Fugitive Dust from Mining. EPA Contract No. 68-02-1321,
PEDCo Environmental Specialists, Inc., Cincinnati, Ohio. June 1976.
45. Peters, J. A. and P. K. Chalekode, "Assessment of Open Sources,"
Presented at the Third National Conference on Energy and the
Environment, College Corner, Ohio. October 1, 1975.
46. The Asphalt Institute. Asphalt Hot Mix Emission Study. College
Park, Maryland. March 1975. p. ill.
2-23
-------
47. Preliminary Evaluation of Air Pollution Aspects of the Drum Mix
Process. EPA-340/1-77-004. U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina. March 1976.
48. Radian Corp. Asphalt Concrete Industry Emission Test Report, Sloan
Construction Company. Prepared for U. S. Environmental Protection
Agency. Research Triangle Park, North Carolina. EMB Report 84-ASP-8.
July 1984. pp. 2-2 and 2-3.
49. GCA Corp. Emission Test Report, Western Engineering Asphalt Concrete
Plant. Prepared for U. S. Environmental Protection Agency. Research
Triangle Park, North Carolina. EMB Project No. 83-ASP-5. pp. 7-8.
50. Reference 30, pp. 23-27.
51. Reference 10, pp. 16-17.
2-24
-------
3. CURRENT STANDARDS FOR ASPHALT CONCRETE PLANTS
3.1 FACILITIES AFFECTED
On June 11, 1973, the Environmental Protection Agency (EPA) proposed
standards for asphalt concrete plants under Section 111 of the Clean Air
Act to control particulate matter and visible emissions. The final
version of the standards was published on March 8, 1974, effective
February 28, 1974, for plants whose construction or modification was
commenced after June 11, 1973.1,2 These standards were reviewed in 1979,
and no changes were made.3
The standards apply to facilities for which construction,
modification, or reconstruction commenced (as defined under 40 CFR 60.2)
after June 11, 1973. Such facilities are termed "affected facilities."
Standards of performance are not applicable to "existing facilities"
(i.e., facilities for which construction, modification, or reconstruction
commenced on or before June 11, 1973). An existing facility may become
an affected facility and, therefore, be subject to standards if the
facility undergoes modification or reconstruction. The term "modified
facility" applies to facilities to which physical or operational changes
have been made that caused an increase in the emission rate of particulate
matter or visible emissions (i.e., the pollutants to which these standards
apply). The term "reconstructed facility" applies when the replacement
cost of components exceeds 50 percent of the cost of building a comparable
new facility. Modification and reconstruction are defined under
40 CFR 60.14 and 60.15, respectively.4
The affected facility under the new source performance standards
(NSPS) for asphalt concrete plants is each asphalt concrete plant (i.e.,
any facility used to manufacture asphalt concrete by heating and drying
3-1
-------
aggregate and mixing with asphalt cements). An asphalt concrete plant is
comprised only of any combination of the following:5
1. Dryers;
2. Systems for screening, handling, storing, and weighing hot
aggregate;
3. Systems for loading, transferring, and storing mineral filler;
4. Systems for mixing asphalt concrete; and
5. Systems for loading, transfer, and storage associated with
emission control systems.
3.2 CONTROLLED POLLUTANTS AND EMISSION LEVELS
Particulate emissions from asphalt concrete plants are controlled
under the NSPS, as defined by 40 CFR, Subpart I, Section 60.92. The
standards prohibit the discharge into the atmosphere from any affected
facility exhaust gases which:
1. Contain particulate matter in excess of 90 milligrams per dry
standard cubic meter (mg/dscm) (0.04 grains per dry standard cubic foot
[gr/dscf]), and
2. Exhibit 20 percent opacity or greater.
3.3 TESTING AND MONITORING REQUIREMENTS
3.3.1 Testing Requirements
Performance tests to verify compliance with the NSPS must be
conducted and a written report of the results submitted within 60 days
after an asphalt plant has reached its full capacity production rate or
within 180 days after the initial startup of the facility, whichever
comes first.6 Under Section 114 of the Clean Air Act, reports of
performance tests may also be required by the Administrator at other
times.6 Emissions measured during startup, shutdown, and malfunctions
are not considered representative for the purpose of demonstrating
compliance.
3.3.1.1 Particulate Matter. The EPA reference test methods used to
determine compliance with the standards covering particulate matter
emissions are:7
1. Method 5 for the concentration of particulate matter and the
associated moisture content of the exhaust gases;
3-2
-------
2. Method 1 for sample and velocity traverses;
3. Method 2 for stack gas velocity and volumetric flow rate
determinations; and
4. Method 3 for analysis of exhaust gases for carbon dioxide (C02),
excess air, and dry molecular weight.
The sampling time for each Method 5 test run shall be at least
60 minutes, and the sampling rate shall be at least 0.9 dry standard
cubic meters per hour (dscm/h) (0.53 dry standard cubic feet per min
[dscf/min]).7 Performance tests consist of three separate runs conducted
during representative plant operating conditions. The standards apply to
the arithmetic mean of the test runs. Waiver provisions are made to allow
compliance to be determined on the arithmetic mean of two runs upon the
approval of EPA. A waiver may be granted for accidental sample loss or
because of conditions which cause one of the three runs to be discontinued
because of sample train failure, forced plant shutdown, extreme meteoro-
logical conditions, or other circumstances beyond the owner or operator's
control.6,7
3.3.1.2 Opacity. Methods for determining compliance with opacity
standards are defined in Section 60.11 of the Code of Federal Regulations.8
Method 9 is used for measuring visible emissions from stationary sources.
Continuous monitoring of opacity is not required.
3.3.2 Recordkeeping and Reporting Requirements
The owner or operator of an asphalt plant must notify the
Administrator between 30 and 60 days prior to initial startup. Notifica-
tion of actual initial startup must be made within 15 days after initial
startup. Notification must also be made of any physical or operational
change to an existing asphalt plant that may increase the emission rate
of any air pollutant to which the standards apply.9
A file of all records and reports on performance tests, monitoring,
and maintenance are to be kept for a period of at least 2 years. Additional
discussion concerning the documentation of representative process and control
device operating conditions during compliance testing is included in
Chapter 7. Records are also to be maintained by the plant owner or operator
of the occurrence and duration of startup, shutdown, or malfunctions in the
process and of malfunctions of the air pollution control equipment.9
3-3
-------
3.4 REFERENCES FOR CHAPTER 3
1. Environmental Protection Agency. Inspection Manual for Enforcement
of New Source Performance Standards, Asphalt Concrete Plants.
EPA 340/1-76-003. Washington, D.C. March 1976. p. 3.
2. Environmental Protection Agency. Code of Federal Regulations.
Title 40, Chapter I, Part 60. Washington, O.C. Office of the Federal
Register. July 1, 1982.
3. Environmental Protection Agency. A Review of Standards of Performance
for New Stationary Sources, Asphalt Concrete Plants. EPA-450/3-79-014.
Research Triangle Park, North Carolina. June 1979.
4. Reference 2, Sections 60.14 and 60.15.
5. Reference 2, Section 60.90.
6. Reference 2, Section 60.8.
7. Reference 2, Section 60.93.
8. Reference 2, Section 60.11.
9. Reference 2, Section 60.7.
3-4
-------
4. EMISSION CONTROL TECHNIQUES AND TEST RESULTS
This chapter describes the design and operating parameters for the
air emission control devices used In the asphalt concrete Industry.
Also Included In this chapter are tabulations of compliance test results
collected from State agencies, a summary of site visits, and a summary
of emission data from EPA-conducted source tests.
4.1 CONTROL DEVICES
Wet scrubbers and fabric filters are the typical particulate control
devices used by asphalt concrete plants to meet the new source performance
standards (NSPS). Most new asphalt concrete plants use knockout boxes
or cyclones as product recovery devices to recover large particulate
matter from the exhaust gas stream and to reduce the particulate load to
the emission control device. The recovered material Is recycled to the
process as filler; thus, these knockout boxes or cyclones are considered
process equipment rather than emission control devices.
4.1.1 Wet Scrubbers
Wet scrubbers cleanse particulate-laden gas streams by entrapping
particulate matter with water droplets. Although a variety of scrubbers
are available, the most commonly used wet scrubber on both batch and
drum-mix plants Is the venturi scrubber. Figure 4-1 Is a schematic of a
typical venturi scrubber. In some system designs, water Is sprayed Into
the ductwork upstream of the throat section of the venturi scrubber to
keep the ductwork clean.1,2 These sprays may remove some particulate
matter from the gas stream through condensation and Impingement mechanisms.
Some control of condenslble hydrocarbons may occur as a result of
the cooling and condensing action of the water sprays. The droplets
formed would then be removed In the same manner as dry particulate
4-1
-------
EXHAUST GAS
I
ro
1 .
1
1
STACK
FAN
/
\
AIR FLOW
WATER
^NOZZLES
SEPARATOR
CHAMBER
^
VENTURI
THROAT
f
*\
PERFORATED
METAL PLATE
DRAIN TO
SETTLING POND
KNOCK OUT
CHAMBER
INLEJ AIR
FLOW
I
PRODUCT
Figure 4-1. Venturi scrubber control device on asphalt concrete plant.
-------
matter. Absorption of the condensible hydrocarbons in the water is also
possible.
Venturi scrubbers in the asphalt concrete industry have pressure
drops that range from 2.5 to 5.2 kilopascals (kPa) (10 to 21 inches of
water column [in. w.c.]).3,4 A typical liquid-to-gas ratio for these
scrubbers is 1,070 liters per thousand cubic meters (2/1,000 m3) (8 gallons
per thousand cubic feet [gal/I,000 ft3]).5,6
The solids concentration in the scrubbing water can affect collection
efficiency. If scrubbing water is recycled from a settling pond, the
water must be sufficiently free of solids to prevent particle reentrainment
in the gas stream and particle carryover to the exhaust gas. Reducing
solids in the scrubber water also helps reduce abrasion and plugging of
scrubber spray nozzles. The settling ponds must, therefore, be constructed
to maximize settling of solids present in the scrubber effluent water.
4.1.2 Fabric Filters
Fabric filters have been used successfully as particulate control
devices in both batch and drum-mix plants. Of the 45 plants visited to
collect background information during this NSPS review, 26 were baghouse-
controlled. The fabric used in most baghouses at asphalt concrete
* fSl
plants is composed of felted Nomex , a nylon that can withstand temperatures
up to 232°C (450°F).7 The typical weight of the fabric is 0.5 kilograms
per square meter (14-ounces [weight] per square yard).4,7-9 The fabric
is formed into long cylindrical bags that are fitted over a cylindrical
wire form, called a "cage", which supports the fabric bags. Fabric
filters on portable asphalt concrete plants are typically no more than
2.4-m (8-ft) wide and 4.3-m (14-ft) high so that they can be transported
on public roads.l°
A fan is located at the outlet of the fabric filter, providing
suction, or negative pressure, to draw the gas stream through the fabric
filter from the dryer or drum. A pressure drop across the fabric filter
bags of 1.0 to 1.6 kPa (4 to 6.5 in. w.c.) is typical. Fabric filters
used in the asphalt concrete industry have a typical air-to-cloth ratio
(ftVmin of airflow per ft2 of cloth area) of 6:1.
4-3
-------
Most fabric filters in the asphalt concrete industry use a pulse
jet cleaning system.10,11 In pulse jet systems, compressed air is
injected into single bags or groups of bags. The air expands the bag
like a balloon and temporarily reverses the direction of the gas flow
through the fabric. The reversed gas flow and expansion of the bag
cause the dust cake to break from the fabric and fall into a hopper at
the bottom of the fabric filter. Typically, screw conveyors move the
collected dust from the hoppers to the discharge area where the material
is recycled back to the production process.
In the normal startup procedure for asphalt concrete plants, the
burner is fired without any aggregate in the drum to increase the
temperature of the gas stream above the water dew point but not so hot
as to damage the fabric.12 This procedure prevents moisture in the gas
stream from condensing on the bags and causing them to clog or "blind."
The shutdown procedure consists of allowing the baghouse to continue
to operate for at least one cleaning cycle after the burner and aggregate
feed have been shut down.13 This procedure removes the dust cake from
the bags and prevents moisture from condensing as the baghouse cools.
4.2 ANALYSIS OF NSPS COMPLIANCE TESTS
During the present review of the asphalt concrete NSPS, 369 compli-
ance test reports were collected from State agencies and reviewed.14 A
summary of this review is presented in Table 4-1. It should be noted
that, due to the mobile nature of the subject plants, it was often
difficult to determine if two test reports for a given company represented
two different plants or the same plant that was relocated.
Of the 292 reports in which the control device was identified,
21 percent of the plants used a baghouse, and 79 percent used a scrubber.
Of the 327 plants identified as either batch or drum-mix, 49 percent
were batch, and 51 percent were drum-mix. Of the 325 plants reporting
numerical test results, 13 percent had particulate emissions greater
than the NSPS limit of 90 milligrams per dry standard cubic meter (mg/dscm)
(0.04 grains per dry standard cubic foot [gr/dscf]). Of these 41 plants,
the majority were scrubber-controlled drum-mix plants. The pressure
4-4
-------
TABLE 4-1. COMPLIANCE TEST REPORT SUMMARY14
Total reports collected
Identified control method
Baghouse
Scrubber
Identified type of plant
Batch
Drum-mix
Identified test results
Test results failed NSPS limit3
Batch plant
Drum-mix plant
Process unidentified
Baghouse controlled
Scrubber controlled
Control method unidentified
Scrubber controlled plants identifying AP
AP <20 in. w.c.
Identified both design capacity and production
rate during test
Production during test: 100% of capacity
90-99% of capacity
80-89% of capacity
70-79% of capacity
60-69% of capacity
50-59% of capacity
40-49% of capacity
30-39% of capacity
0-29% of capacity
Used RAP during test
Drum-mix
Batch
Process unidentified
Baghouse controlled
Scrubber controlled
Failed NSPS
Drum-mix plant
Process unidentified
Baghouse controlled
Scrubber controlled
No.
369
292
(62)
(230)
327
(160)
(167)
325
(41)
(4)
(23)
(14)
(8)
(25)
(8)
60
(49)
150
(20)
(21)
(31)
(20)
(29)
(20)
(6)
(1)
(2)
51
(49)
(0)
(2)
(23)
(28)
(9)
(7)
(2)
(1)
(8)
Percent
(21)
(79)
(49)
(51)
(13)
(10)
(56)
(34)
(20)
(61)
(20)
(82)
(13)
(14)
(21)
(13)
(19)
(13)
(4)
(1)
(2)
(96)
(0)
(4)
(45)
(55)
(18)
(78)
(22)
(11)
(89)
a90 milligrams per dry standard cubic meter (mg/dscm) (0.04 grains per
dry standard cubic foot [gr/dscf]).
4-5
-------
drop (AP) across the scrubber was not monitored during most testing;
however, of the 60 plants that did report a AP across the scrubber,
82 percent were less than 5 kPa (20 in. w.c.). The AP distribution
among these 60 plants is illustrated in Figure 4-2. Of the 150 plants
reporting both design capacity and production rate during testing,
52 percent were operated below 80 percent of design capacity during
testing. This distribution is shown in Table 4-1.
Of the 369 reports collected, 99 reports included opacity information.
Of these 99 reports, 31 presented complete opacity data, 58 gave summaries
only, and 10 gave time periods for opacity readings but gave no opacity
data. Of the 89 reports presenting either complete or summarized opacity
data, 7 reports had 6-minute averages greater than 20 percent. Three of
these plants were producing conventional mix. These three also reported
particulate emissions greater than 90 mg/dscm (0.04 gr/dscf). The
remaining four plants with opacity greater than 20 percent were utilizing
recycled asphalt pavement (RAP) during testing. Of these four, one had
particulate emissions greater than 90 mg/dscm (0.04 gr/dscf), two had
particulate emissions less than 90 mg/dscm (0.04 gr/dscf), and one did
not report the particulate emission level.
The majority of test reports did not include any information'on the
type of asphalt concrete being produced or whether RAP was used during
testing. Of the 51 reports clearly identifying the use of RAP during
testing, 96 percent were drum-mix plants, and 4 percent did not identify
the type of process; also, 45 percent were baghouse controlled, and
55 percent were scrubber controlled. Eighteen percent of the plants
using RAP during testing had particulate emissions greater than 90 mg/dscm
(0.04 gr/dscf). Most of these plants were scrubber-controlled drum-mix
plants.
4.3 ANALYSIS OF SITE VISITS
Site visits were conducted to collect general background information
on the asphalt concrete industry and to select representative plants for
testing. Visits were made to 45 asphalt plants owned by 34 different
companies and to 5 equipment manufacturers.15 Almost all of the plants
visited were equipped to utilize RAP. Although some plants reportedly
4-6
-------
-vJ
C/l
H
<
a.
u
o
CD
41 51 61 718 910
1n. w.c.
Figure 4-2. AP distribution among NSPS compliance tests.
-------
were capable of using up to 66 percent RAP, most did not exceed 50 percent
RAP in actual practice. The most common RAP usage range was 25 to 30 percent.
Because RAP usage appears to be more common with drum-mix plants than
with batch plants and because of the interest in plants utilizing RAP,
only 7 of the 45 plants visited were batch plants. Five of the seven
batch plants were scrubber-controlled, and two were baghouse-controlled.
Of the 38 drum-mix plants visited, 14 were scrubber-controlled, and 24
•
were baghouse-controlled. Although most venturi scrubbers used at
asphalt plants are designed to operate at a 5 kPa (20-in. w.c.) pressure
drop (AP), it was found that the average normal operating pressure drop
is about 4.0 kPa (16 in. w.c.). About 25 percent of the scrubber-controlled
plants reporting a AP value reported operating their scrubbers at 5 kPa
(20 in. w.c.) or more.15 About half of the plants visited reported blue
haze emissions during production of RAP mixes. This blue haze generally
developed downwind from the plant.15
4.4 ANALYSIS OF EMISSION TESTS CONDUCTED BY EPA DURING NSPS REVIEW
During the NSPS review, tests were conducted by EPA at four asphalt
concrete plants.16 These plants were chosen for testing because their
ductwork configurations allowed for testing of both uncontrolled and
controlled emissions and because they had predictable production schedules
that included both conventional and RAP mixes. The plants were operated
above 80 percent of capacity during production of the various mixes.
The control device and the amount of RAP used at Plants A, B, C, and D
are presented in Table 4-2. Plant design and operating parameters at
the four plants are presented in Table 4-3. Scrubber and baghouse
design and operating parameters are presented in Tables 4-4 and 4-5,
respectively.
The following analyses were performed at some or all of the test
sites:
1. Particulate emission level;
2. Total organic carbon/extractable organic emission level;
3. Visible emission level;
4. Particle size determinations;
5. Polynuclear aromatic hydrocarbon emission level; and
6. Trace metals concentration.
4-8
-------
TABLE 4-2. CONTROL DEVICE AND RAP UTILIZATION16
Plant
Control device
Mix produced
A
B
C
D
Venturi scrubber
Venturi scrubber
Baghouse
Baghouse
Conventional and 25 percent RAP
50 percent RAP
Conventional and 30 percent RAP
Conventional and 50 percent RAP
4-9
-------
TABLE 4-3. PLANT DESIGN AND OPERATING PARAMETERS16
Plant
Type
Capacity, Mg/h (tons/h)
Rated
Typical
During test
Dryer fuel
Approximate drum size, m (ft)
Diameter
Length
Product temperature, °C (°F)
RAP entry position
Asphalt cement
Conventional
RAP
A
Drum-mix
218 (240)17
218 (240)
214 (236)
Natural gas
2.4 (8)
11 (36)
135-163
(275-325)
Centerfeed
AC- 20
AC-7.5
B
Drum-mix
229 (252)
181 (200)
181 (200)
No. 5 fuel oil
2.1 (7)
13 (42)
135-149
(275-300)
Centerfeed
HMA-175
C
Drum-mix
386 (425)
272 (300)
218 to 308a
(240-340)3
Natural gas
2.7 (9)
12 (38)
154
(310)
Centerfeed
AC-20
AC-10
D
Drum-mix
390 (430)
272-318 (300-350)
279 (307)
No. 5 fuel oil
2.7 (9)
12 (40)
135-143
(275-290)
Centerfeed
85-100 penetration
120-150 penetration
Average production rate during 30 percent RAP mix was 308 Mg/h
was 218 Mg/h (240 tons/h).
(340 tons/h); during conventional mix
-------
TABLE 4-4. SCRUBBER DESIGN AND OPERATING PARAMETERS16
B
Type
Total airflow, mVmin (acfm)
Design
During test
•
Water circulation rate,
jfc/min (gpm)
Design
During test
Make-up water source
AP across venturi during test,
kPa (in. w.c.)
Liquid/gas ratio, £/m3
(gal/1,000 acf)
Design
During test
Ponds:
No.
Size, m (ft)
Length
Width
Depth
Total volume, 1,000 £
(1,000 gal)
Residence time, h
Venturi scrubber
991-1,020
(35,000-36,000)
825
(29,080)
1,140
(300)
828
(220)
Groundwater,
as needed
AP, design, kPa (in. w.c.)18,19 13.5-15.5
3.1-3.6 •
(12.5-14.5)
1.1-1.2
(8.3-8.6)
1.0
(7.6)
17, 20 (55, 65)
7.3, 7.3 (24, 24)
0.9-1.8, 0.9-1.8
(3-6, 3-6)
246-492
(65-130)
3.6-7.2
Venturi scrubber
1,220
(43,000)
1,030
(36,500)
1,140-1,510
(300-400)
1,368
(362)
Groundwater
20
4.3-5.0
(17-20)
0.93-1.2
(7.0-9.3)
1.3
(9.9)
18, 18 (60, 60)
5.5, 7.3 (18, 24)
1.5, 1.5
(5, 5)
358
(94.5)
3.9-5.2
mVmin = actual cubic meter per minute
acfm = actual cubic feet per minute
£/min = liter per minute
gpm = gallon per minute
kPa = kilopascal
in. w.c. = inches of water column
4-11
-------
TABLE 4-5. BAGHOUSE DESIGN AND OPERATING PARAMETERS16
Type
Total airflow rate, mVmin
(acfm)
Design
During test
No. of bags
Bag material
Normal pressure drop, kPa
(in. w.c.)
Bag cleaning mechanism
Air-to-cloth ratio,
Design
During test
Dust disposal
Negative pressure
baghouse
1,470
(52,000)
1,320
(46,670)
462
Nomex
1
(4)
Pulse jet
-7:1
-6.3:1
Recycled to drum
Negative pressure
baghouse
1,590
(56,000)
1,200
(42,200)
900
Nomex
1.3
(5)
Pulse jet
6.3:1
4.8:1
Recycled to drum
4-12
-------
In addition, selected physical characteristics were determined for
samples of RAP, asphalt cement, aggregate, and scrubber water.
4.4.1 Participate Emissions (Front-Half Catch)
The uncontrolled and controlled particulate emission levels during
production of conventional and RAP mixes at the four representative
plant sites are presented in Table 4-6. The corresponding process
parameters are presented in Table 4-7.
For conventional mixes, the uncontrolled particulate emissions
ranged from 12,600 mg/dscm to 253,000 mg/dscm (5.58 to 112.66 gr/dscf).
The uncontrolled particulate emissions were generally lower during
production of RAP mixes than during production of conventional mixes.
For RAP mixes, the uncontrolled particulate emissions ranged from
7,290 mg/dscm to 24,600 mg/dscm (3.24 to 10.93 gr/dscf).
The controlled particulate emissions during production of conventional
mixes at Plants A and C and the controlled particulate emissions during
production of RAP mix at Plant B exceeded the NSPS limit of 90 mg/dscm
(0.04 gr/dscf). The NSPS limit is based on emission data that are
representative of the performance of a 5 kPa (20 in. w.c.) pressure drop
venturi scrubber. The pressure drop across the venturi at Plant A
•
averaged between 3.3 and 3.4 kPa (13.4 and 13.5 in. w.c.) during production
of conventional mix. This lower pressure drop contributed to the plant's
failure to meet the NSPS while producing conventional mixes. Due to the
low uncontrolled emission level during production of RAP mix, the scrubber
met the NSPS despite its low pressure drop.
The pressure drop across the venturi at Plant B averaged between
4.2 and 5 kPa (17 and 20 in. w.c.) during testing. During one period,
the pressure drop across the venturi dropped to 3.2 kPa (13 in. w.c.).
The dissolved solids concentration in the scrubber water at Plant B was
approximately seven times the dissolved solids concentration observed at
Plant A. The high dissolved solids level and low pressure drop
contributed to the failure of Plant B to meet the present NSPS.
After test Run C-l at Plant C, problems were encountered with the
operation of the plant that resulted in blinding of the bags and a
pressure drop across the baghouse of greater than 2.5 kPa (10 in. w.c.).
Although the bags were subsequently cleaned and the average pressure
4-13
-------
TABLE 4-6. SUMMARY OF EMISSION DATA FROM EPA-CONDUCTED TESTS
Production data
Plant
A
A
A
A
A
A
B
B
B
B
C
C
c
Run
No
C-l
C-2
C-3
R-l
R-2
R-3
R-l
R-2
R-3
R-4
C-l
C-2
C-3
Total
produc-
tion,
Mg/h
(tons/h)
220
(243)
213
(235)
179
(218)
207
(228)
229
(252)
219
(241)
188
(207)
172
(190)
178
(196)
185
(204)
216
(238)
218
(240)
218
(240)
RAP,
0
0
0
25
24
25
51
51
51
51
0
0
0
Mix
temp. .
°C (°F)
142
(288)
136
(277)
143
(289)
146
(295)
135
(275)
141
(286)
142
(288)
143
(290)
143
(290)
140
(284)
159
(319)
165
(329)
162
(323)
Emissions data
Outlet-controlled
Inlet-uncontrolled
Dry
catch,
mg/dscm
(gr/dscf)
17.400
(7 60)
19,400
(8.49)
12,800
(5.58)
7,410
(3.24)
10,000
(4.37)
8.580
(3.75)
18,500
(8.09)
12.700
(5.54)
14.100
(6.15)
12,100
(5.28)
43,500
(19 01)
34.400
(15.05)
38.200
(16 70)
TOC.
mg/dscm
(gr/dscf)
a
a
a
a
a
a
799
(0.349)
117
(0.051)
124
(0 054)
119
(0.052)
a
a
a
Film,
mg/dscm
(gr/dscf)
396
(0.173)
105
(0.046)
261
(0.114)
311
(0.136)
304
(0 133)
142
(0.062)
b
b
b
b
69
(0.030)
82
(0.036)
89
(0.039)
Dry
catch,
mg/dscm
(gr/dscf)
126
(0 055)
185
(0.081)
76
(0.033)
52
(0.023)
S3
(0.023)
66
(0.029)
263
(0.115)
297
(0.130)
327
(0. 143)
259
(0.113)
25
(0.011)
297
(0.130)
2.950
(1.29)
TOC.
mg/dscm
(gr/dscf)
a
a
a
a
a
a
53
(0.023)
57
(0.025)
57
(0.025)
43
(0.019)
a
a
a
Film.
mg/dscm
(gr/dscf)
128
(0.056)
32
(0 014)
21
(0.009)
25
(0.011)
71
(0.031)
39
(0.017)
b
b
b
b
32
(0.014)
62
(0.027)
96
(0.042)
Awg.
opa-
city.
0
0
NA
1.4
0 3
NA
8 4
13.6
12.3
9 8
c
c
c
.
Max
6-nin
opa-
city.
1.5
0
NA
5 8
1.7
NA
11.9
17.5
16.9
12 9
c
c
c
(continued)
-------
TABLE 4-6. (continued)
en
Emissions data
Production data
Plant
C
C
C
D
0
0
0
D
0
0
Run
No
R-l
R-2
R-3
C-l
C-2
C-3
C-4
R-l
R-2
R-3
Total
produc-
tion,
My/h
(tons/h)
316
(348)
308
(339)
307
(338)
281
(310)
282
(311)
277
(305)
244
(269)
301
(332)
281
(310)
281
(310)
Outlet-controlled
Inlet-uncontrol led
RAP,
X
27
29
28
0
0
0
0
49
49
49
Mix
temp .
°C (°F)
157
(315)
156
(312)
161
(321)
153
(307)
152
(305)
149
(300)
149
(301)
143
(290)
143
(290)
143
(290)
Dry
catch,
mg/dscm
(gr/dscf)
12,700
(5.54)
16,000
(7 00)
15.600
(6 82)
106,000
(46 33)
258.000
(112.66)
201.000
(8784)
123.000
(53 50)
16.200
(7.08)
25.000
(10.93)
19.800
(8.66)
TOC.
mg/dscm
(gr/dscf)
a
a
a
NA
105
(0.046)
39
(0.017)
96
(0 042)
64 '
(0.028)
240
(0.105)
80
(0.035)
Film.
mg/dscm
(gr/dscf)
80
(0.035)
64
(0.028)
66
(0.029)
71
(0.031)
108
(0.047)
57
(0.025)
606
(0.265)
37
(0.016)
85
(0.037)
220
(0.096)
Dry
catch.
mg/dscm
(gr/dscf)
41
(0.018)
76
(0.033)
34
(0.015)
18
(0.008)
57
(0.025)
64
(0.028)
50
(0.022)
18
(0.008)
14
(0.006)
TOC.
mg/dscm
(gr/dscf)
a
a
a
41
(0.018)
41
(0.018)
37
(0.016)
37
(0 016)
137
(0.060)
117
(0.051)
Film.
mg/dscm
(gr/dscf)
NA
137
(0 060)
14
(0 006)
23
(0.010)
50
(0.022)
23
(0 010)
18
(0 008)
ros
(0.046)
34
(0.015)
A»g.
opa-
city.
*
c
c
c
NA
0 25
NA
NA
4.5
NA
NA
Max.
6-oin
opa-
city.
X
c
c
c
NA
1 3
NA
NA
5
NA
NA
NA = Not available
*IOC data and total emission data are not included for Plants A and C due to problems with TOC testing methodology and analytical procedures.
"No film was collected at Plant B.
The opacity readings from Plant C are not Included due to technical problems experienced with the reading of opacity at this plant.
-------
TABLE 4-7. SUMMARY OF PROCESS PARAMETERS FROM EPA-CONDUCTED TESTS16
cn
Production data
Plant
A
A
A
A
A
A
B
B
B
B
C
C
C
Run
No.
C-l
C-2
C-3
R-l
R-2
8-3
R-l
R-2
R-3
8-4
C-l
C-2
C-3
Total
produc-
tion,
Hg/h
(tons/h)
220
(243)
213
(235)
179
(218)
207
(228)
229
(252)
219
(241)
188
(207)
172
(190)
178
(196)
185
(204)
216
(238)
218
(240)
218
(240)
HAP.
X
0
0
0
25
24
25
51
51
51
51
0
0
0
Hix
leap
°C (°f)
142
(288)
136
(277)
143
(289)
146
(295)
135
(275)
141
(286)
142
(288)
143
(290)
143
(290)
140
(284)
159
(319)
165
(329)
162
(323)
Virgin RAP
•ois- Mois-
ture. X ture, X
2.7
23
2.6
1.5 1 b
1.8 1.4
12 21
4.1 2.6
59 16
6 4 1.9
5.7 1.8
33
38
34
RAP
snake Pressure
point, drop, fcPa
*C (°f) (in. M.C.)
3.36 (13 5)
2.33 (13 4)
3.36(13.5)
179 (355) 3 44 (13.8)
3.44 (13.8)
3 46 (13.9)
179 (355) 4.48 (18)
•
179 (355) 4.23 (17)
180 (356) 4.98 (20)
177 (350) 4 98 (20)
1.1 (4.3)a
1.3(51)"
1.5 (5.9)"
Scrubber data-- influent
Sus- Ois-
pended solved
solids, solids,
•g/t BQ/l pH
161 1,860 7.3
24 1.780 7.3
124 1,770 7.4
78 1.960 7.3
144 1.970 7 3
179 1.890 7 4
57 14.700 6.2
18 12.100 6.1
34 13.000 6 1
49 13.800 6 1
liquid
to gas.
gal/scf
0019
0 017
0 015
0.018
0 016
0 021
0020
0 021
0 022
56"
56"
5.6"
Water
temp..
"C (*F)
56 (132)
52 (126)
48 (118)
43 (109)
55 (131)
43 (110)
58 (137)
51 (124)
59 (138)
60 (140)
-------
TABLE 4-7. (continued)
Production data
Plant
C
C
C
0
0
i
3 o
0
0
0
0
inn
No.
i-1
8-2
8-3
C-l
C-2
C-3
C-4
i-1
1-2
8-3
Total
produc-
tion,
Hg/b
(tons/b)
316
(340)
300
(339)
307
(330)
201
(310)
202
(311)
277
(305)
244
(269)
301
(332)
201
(310)
201
(310)
Scrubber data— influent
IAP.
27
29
20
0
0
0
0
49
49
49
Mix
tttV).
Of /°ft
157
(315)
156
(312)
161
(321)
153
(307)
152
(305)
149
(300)
149
(301)
143
(290)
143
(290)
143
(290)
iAP
Virgin iAP sioke
Mis- Mis- point,
ture. X ture, X C (°f)
3.4 NA 99 (211)
5.7 3.2 90 (209)
3.2 5.1 100(212)
2.1
2.0
2.3
3.2
4.0 2.0 173 (344)
1.7 4.1 102(360)
1.7 4.1 102(360)
Sus- Ois-
Pressura pended solved
drop. kPa solids. solids,
(In. w.c.) ag/l •0/1 pll
1.0 (4.0)'
1.0 (4.0)'
1.0 (4.0)'
1.4 (5.5)'
1.4 (5.6)'
1.4 (5.6)'
1.2 (5.0)'
1.1 (4.3)'
1.2 (4.7)'
1.2 (4.7)'
Liquid Water
togas, te*¥-.
gal/scf •£ (*f)
S.6b
56"
5.6b
6.3b
6.3b
6.3b
6.3b
6 3b
6.3b
6.3b
?0dylutuse pressure drop.
Oaghouse alr-to-clolh ratio, acfa/ll1, design
-------
drop across the baghouse was 1.3 and 1.5 kPa (5.1 and 5.9 in. w.c.) for
Runs C-2 and C-3, respectively, the previous blinding and high pressure
drop apparently created leaks in the bags and caused Plant C not to meet
the NSPS during Runs C-2 and C-3. Runs R-l, R-2, and R-3 at Plant C
were performed prior to this blinding.
Because of the lower uncontrolled particulate emission levels
during production of RAP mixes, the controlled particulate emission
levels at Plants A and D were lower during production of RAP mixes than
during production of conventional mixes. Only RAP mixes were produced
at Plant B, and problems with the baghouse were experienced at Plant C,
as already discussed.
4.4.2 Total Organic Carbon
The total organic carbon (TOC) emission results are presented in
Table 4-6. Due to problems with TOC testing methodology and analytical
procedures (as discussed in Appendix C), TOC data for Plants A and C are
not included.
An organic film was collected from the impinger walls during the
TOC tests at Plants A and C. Since this film is measured gravimetrically
and TOC is a measure of carbon present as a constituent of organic
compounds, the two results cannot be added directly.
The uncontrolled and controlled emission level of the material
comprising this film ranged from 105 to 396 mg/dscm (0.046 to 0.173 gr/dscf)
and from 21 to 128 mg/dscm (0.009 to 0.056 gr/dscf), respectively,
during production of conventional mix at Plant A. During production of
RAP mix at Plant A, the uncontrolled and controlled emission level of
the material comprising the film ranged from 142 to 311 mg/dscm (0.062
to 0.136 gr/dscf) and 25 to 71 mg/dscm (0.011 to 0.031 gr/dscf), respectively.
During production of conventional mix at Plant C, the uncontrolled
and controlled emission level of the material comprising the film ranged
from 69 to 89 mg/dscm (0.030 to 0.039 gr/dscf) and 32 to 96 mg/dscm
(0.014 to 0.042 gr/dscf), respectively. During production of RAP mix at
Plant C, the uncontrolled and controlled emission level of the material
comprising the film ranged from 64 to 80 mg/dscm (0.028 to 0.035 gr/dscf),
and 14 to 134 mg/dscm (0.006 to 0.060 gr/dscf), respectively.
4-18
-------
The uncontrolled TOC emissions at Plant B ranged from 117 to
799 mg/dscm (0.05 to 0.349 gr/dscf) during production of RAP mixes and
the controlled TOC emissions ranged from 43 to 57 mg/dscm (0.019 to
0.025 gr/dscf). No film was observed on the TOC impinger walls during
testing at Plant B.
During production of conventional mixes at Plant D, the uncontrolled
TOC emissions ranged from 39 to 105 mg/dscm (0.017 to 0.046 gr/dscf), and
the controlled TOC emissions ranged from 37 to 41 mg/dscm (0.016 to
0.018 gr/dscf). During production of RAP mixes at Plant 0, the uncontrolled
TOC emissions ranged from 64 to 240 mg/dscm (0.028 to 0.105 gr/dscf) and
the controlled TOC emissions ranged frm 117 to 137 mg/dscm (0.051 to
0.060 gr/dscf).
A film was observed on the TOC impinger walls during testing at
Plant D. During production of conventional mixes at Plant D, the
uncontrolled and controlled emission level of the material comprising
this film ranged from 71 to 606 mg/dscm (0.031 to 0.265 gr/dscf) and 18
to 50 mg/dscm (0.008 to 0.022 gr/dscf), respectively. During production
of RAP mixes at Plant D, the uncontrolled and controlled emission level of
the material comprising this film ranged from 37 to 220 mg/dscm (0.016
to 0.096 gr/dscf) and 34 to 105 mg/dscm (0.015 to 0.04 gr/dscf),
respectively.
Based on the results of EPA-conducted source tests, the only
correlation that can be drawn is that TOC emissions are approximately
equal during production of RAP and conventional mixes.
4.4.3 Visible Emissions
The test average and maximum 6-minute average opacity readings for
emission tests performed during production of both conventional and RAP
mixes at Plants A, B, and D are presented in Table 4-6. The test average
and maximum 6-minute average opacity readings at Plant A ranged from 0.3
to 1.4 and 1.5 to 5.8, respectively. At Plant B, the test average and
maximum 6-minute average opacity readings ranged from 8.4 to 13.6 and
11.9 to 17.5, respectively. Ranges of 0.25 to 4.5 and 1.3 to 5 were
observed for the test average and maximum 6-minute average opacity
readings, respectively, at Plant D. No readings were made during some
test runs due to overcast skies.
4-19
-------
Field data sheets from Plant C indicate that some or all of the
opacity readings at Plant C were made within the steam plume instead of
in the areas specified by EPA Reference Method 9. For this reason,
opacity readings are not given in Table 4-6 for Plant C.
The visible emission data for the scrubber and baghouse control
systems should not be compared. The baghouse data from Plant 0 were
obtained from observations made at the stack outlet, prior to the stack
gases condensing and becoming visible. In contrast, an attached steam
plume was present at the exhaust stack of the wet scrubber at Plants A
and B. As specified in Method 9, the observations reported for Plants A
and B were made at a point in the emissions plume where the condensed
water vapor was no longer visible. Because of the steam plume, the
scrubber data at Plants A and B were obtained from observations made 24
to 61 m (80 to 200 ft) downstream from the stack.
4.4.4 Particle Size Determinations
The results of the particle size analyses on uncontrolled emission
streams at Plants A and B are presented in Figure 4-3. In general, the
particles emitted during production of RAP mixes are larger than those
emitted during production of conventional mixes. For the three runs
conducted during RAP production, the results show that between 15 and
30 percent of the total mass of particulate matter is less than 10 micro-
meters (urn) in diameter. For the three runs conducted during production
of conventional mix, the particle size distribution measurements show
that between 45 and 60 percent of the total particulate mass is less
than 10 urn in diameter.
The particle size distribution tests conducted at Plant C were all
outside the accepted isokinetic range. Therefore, these data were
discarded.
No particle size distribution tests were conducted at Plant D due
to curtailed process operations.
4.4.5 Polynuclear Aromatic Hydrocarbons
A summary of the uncontrolled and controlled polynuclear aromatic
hydrocarbon (PAH) emissions during conventional operation at Plant A is
presented in Table 4-8. Table 4-9 presents a summary of uncontrolled and
controlled PAH emissions during recycle operations at Plant A.
4-20
-------
TABLE 4-8. SUMMARY OF POLYNUCLEAR AROMATIC HYDROCARBON EMISSIONS DURING
CONVENTIONAL OPERATION—PLANT A16
Process/testing parameters
Date
Volume gas sampled, dscm (dscf)
Stack gas flow rate, mVmin (dscfm)
Stack temperature, °C (°F)
Scrubber pressure drop, In. w.c.
Scrubber water flow rate, gpm
Percent moisture by volume
Percent isokinetic
Production rate, tons/h
CONCENTRATIONS AND
Uncontrolled
11/14/83
0.3472 (12.3)
289 (10,200)
156 (313)
13.4
220
42.2
111
196
MASS EMISSION RATES
Controlled
11/14/83
1.1963 (42.4)
331 (11,700)
70 (158)
13.4
220
32.2
103
196
Polynuclear aromatic Uncontrolled- total Controlled total
hydrocarbon results
Active carcinogenic species3
Benz(a)anthracene
Chrysene
Benzo(b)f 1 uoranthene
Benzo(j)fluoranthene
Benzo(e)pyrene
Benzo(a)pyrene
Indeno(l,2,3-c,d)-pyrene
Nonactive carcinogenic species
Phenanthrene
Anthracene
Fl uoranthene
Pyrene
Benzo(k)f 1 uoranthene
Perylene
Benzo(g , h , i )pery 1 ene
(ug/dscm)
1.4
7.3
0.58
NDb
3.5
1.4
1.7
140
20
13
36
0.58
0.58
NO
(mg/h)
24
130
10
61
24
29
2,400
350
230
620
10
10
aFutoma, David, et al. Polycyclic Aromatic Hydrocarbons
(ug/dscm)
0.22
1.2
0.50
ND
0.17
ND
0.084
100
7.1
2.5
6.4
0.50
0.17
ND
in Water
(mg/h)
4.4
24
9.9
3.4
1.7
2,000
140
56
150
9.9
3.4
Systems.
Boca Raton, Fla., CRC Press, Inc., 1981. Reference used to determine if
.PNA species were active or nonactive carcinogens.
DNO = not detected.
4-21
-------
TABLE 4-9. SUMMARY OF POLYNUCLEAR AROMATIC HYDROCARBON EMISSIONS DURING
RECYCLE OPERATION—PLANT A16
Process/testing parameters
Uncontrolled
Controlled
Date
Volume gas sampled, dscm (dscf)
Stack gas flow rate, mVmin, (dscfm)
Stack temperature, °C (°F)
Scrubber pressure drop, In. w.c.
Scrubber water flow rate, gpm
Percent moisture by volume
Percent isokinetic
Production rate, tons/h
11/15/83
0.4590 (16.2)
294 (10,400)
148 (299)
12.7
214
48.0
105
166
11/15/83
1.2789 (45.2)
280 (9,900)
78 (173)
12.7
214
43.4
113
166
CONCENTRATIONS AND MASS EMISSION RATES
Polynuclear aromatic
hydrocarbon results
Uncontrolled total
(ug/dscm)(mg/h)
Controlled total
(ug/dscm)(mg/h)
Active carcinogenic species
Benz(a)anthracene 1.8 32
Chrysene 8.4 150
Benzo(b)fluoranthene 0.087 1.5
Benzo(j)fluoranthene ND
Benzo(e)pyrene 1.9 34
Benzo(a)pyrene 0.50 8.8
Indeno(l,2,3-c,d)-pyrene 0.15 2.6
Nonactive carcinogenic species
0.75
2.6
0.24
ND
0.55
0.31
0.31
13
44
4.0
9.2
5.2
5.2
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(k)fluoranthene
Perylene
Benzo(g , h , i )pery 1 ene
220
16
20
36
0.11
0.33
ND
3,900
280
350
640
1.9
5.8
87
18
13
26
0.24
0.16
ND
1,500
300
220
440
4.0
2.7
ND = Not detected.
aFutoma, David, et al. Polycyclic Aromatic Hydrocarbons in Water Systems.
Boca Raton, Fla., CRC Press, Inc., 1981. Reference used to determine if
PNA species were active or nonactive carcinogens.
4-22
-------
Polynuclear aromatic hydrocarbon tests were conducted during the
emission tests at Plant B; however, the two air samples for PAH were
lost during the analysis because of a condenser problem. Scrubber water
samples were analyzed for PAH, and the results are summarized in
Section 4.4.8.
4.4.6 Trace Metals
A set of air emission samples (uncontrolled and controlled) as well
as a set of scrubber water samples (influent and effluent) were analyzed
for trace metals at Plant A. The results of the air trace metal emission
tests are presented in Tables 4-10 and 4-11 for conventional and RAP
operation, respectively. The scrubber water analysis results are
presented in Section 4.4.8.
During both conventional and recycle operations, the uncontrolled
and controlled concentrations of calcium, iron, magnesium, and aluminum
comprised more than 99 percent of the trace metals analyzed in the
samples.
Several "more volatile" elements were also detected in the trace
metal samples. These elements included beryllium and cadmium. Because
of their volatility, a greater percentage of these elements was found in
the back half portion of the trace metal sample than was found of the
above mentioned nonvolatile elements.
Trace metals were not measured at any of the remaining sites.
4.4.7 RAP. Asphalt Cement, and Aggregate Analyses
The moisture content data for the aggregate and RAP at the four
test sites are presented in Table 4-7. The virgin aggregate moisture
content ranged from 1.2 to 6.4 percent. The moisture content of the RAP
ranged from 1.4 to 5.1 percent.
Samples of RAP and asphalt cement were collected during each run
and analyzed for smoke point. The flash point was also determined for
the asphalt cement. The results of these tests are presented in
Table 4-12.
The asphalt cement used at Plant B was rated by its manufacturer to
be HMA-175. This is an asphalt in which the oils that are blended in to
adjust the viscosity are generally heavier than those used in other
asphalt cements. HMA-grading and AC-grading are not compatible; therefore,
4-23
-------
TABLE 4-10. SUMMARY OF TRACE METAL EMISSIONS DURING CONVENTIONAL OPERATION--PLANT A
Samples
Production rai
tons/h
Trace metal
Element
Aluminum
Beryllium
Calcium
Cadmi urn
Chromium
Iron
Mercury
Magnesium
Manganese
Nickel
Lead
Vanadium
Zinc
Uncontrolled
te,
Mass
front
half, ug
29,500
2.33
2,654,000
14.7
138
57,700
<273
42,900
911
104
118
<540
194
_ ______ o
e.
Mass
back
half, ug
66
0.90
1,260
5.4
1.47
53
<20
50
1.8
<4.4
<118
<88
13
A A _________
nn
Mass
total , ug
29,600
3.23
2,660,000
20.1
138
57,800
<293
43,000
913
104
118
<628
207
Concen-
tration,
ug/dscm
55,000
6.0
4,930,000
37
255
107,000
<544
79,600
1,700
193
219
<1,170
385
Mass
front
half, ug
453
0.187
41,000
28
7.2
650
<90
1,234
42.7
16.4
4.7
<115
42.2
Controlled
________ tA
eA
Mass
back
half, ug
98
2.6
1,283
13
12
61
<56
230
5.1
<5.6
<152
<113
9.6
A _________
q.
Mass
total, ug
551
2.8
42,300
41
19
711
<146
1,460
48
16
4.7
<228
52
Concen-
tration,
ug/dscm
404
2.0
31,000
30
14
521
<107
1,070
35
12
3.4
<167
38
-------
i
l\3
tn
888
888
886
88
88-
86
80
I «
@ 70
i -
I M
40
ao
20
10
2
I
06
02
01
Conventional (PLANT A)
25* RAP
(PLANT A)
50* .RAP(PLANT B)
s
10)
PARIICLf 81ZC M1CAONB
Figure 4-3. Particle size distribution curves of uncontrolled emissions
collected during recycle and conventional operation.16
-------
TABLE 4-11. SUMMARY OF TRACE METAL EMISSIONS DURING RECYCLE OPERATION-PLANT A
Samples
Production ral
tons/h
Trace metal
Element
Aluminum
Beryllium
-P, Calcium
er> Cadmium
Chromium
Iron
Mercury
Magnesium
Manganese
Nickel
Lead
Vanadium
Zinc
_ — _ Uncontrolled __-______.
L __ _____ ____
Le,
Mass
front
half, M9
13,300
0.91
1,154,000
13.7
111
26,600
<136
22,600
362.3
63.6
89
<141
230
_ _ __ o
____ ^
Mass
back
half, pg
69
1.37
751
6.6
6.25
64
<40
121
3.2
2.8
<113
<82
14
AA _________
nn
Mass
total, M9
13,300
2.28
1,150,000
20.3
117
24,600
<176
22,700
366
66
89
<223
244
Concen-
tration,
ug/dscm
22,500
3.9
1,960,000
34
199 .
41,800
<298
38,500
620
112
150
<378
414
Mass
front
half, pg
201
0.22
18,400
5.8
8.4
320
<60
500
18.1
12
4.2
<120
67.3
.___ PA— .4-innl "\r\rl _______________
Lontroiiea
________ 1A
___ £H
Mass
back
half, pg
<70
<0.70
730
<2.8
<1.4
9.8
<41
<47
<1.4
4.8
_^ 1 T Q
x A AO
<84
7.6
A _ _ ____
4 ---------
Mass
total, ug
201
0.22
19,100
5.8
8.4
330
<101
500
18.1
16.8
4.2
<204
74.9
Concen-
tration,
pg/dscm
124
0.14
11,800
3.6
5.2
204
<62
309
11
10
2.6
<126
46
-------
TABLE 4-12. RAP AND ASPHALT CEMENT DATA16
Smoke
point, °C (°F)
Plant
A
B
C
D
Type mix
Conventional
RAP
RAP
Conventional
RAP
Conventional
RAP
RAP
— —
179
(355)
179
(354)
— _
99
(211)
__
179
(355)
AC
216
(420)
174
(345)
182
(360)
N/A
N/A
N/A
3
N/Aa
Flash
point,
°C (°F)
AC
338
(640)
288
(550)
304
(580)
N/A
279
(534)
244
(471)
218
(424)
AC grade
AC-20
HMA-175
AC-20
AC-10
Penetration 85-100
Penetration 120-150
N/A = Not available.
4-27
-------
the asphalt cement used at Plant B cannot be readily compared to those
used at the other plants. No viscosity tests were performed on this
asphalt cement.
The asphalt cements used at Plant D are rated based on penetration
grade instead of AC grade. The viscosities of these asphalt cements
were found to be 1,153 poise and 876 poise at 60°C (140°F) for the
asphalt cements used with conventional and RAP mixes, respectively.
Both these viscosities fall within the 1,000 ± 200 poise range specified
for AC-10 by the Asphalt Institute.
The smoke point of the RAP at three of the test sites was approxi-
mately 179°C (355°F). The smoke point at the fourth test site was about
99°C (211°F).
The smoke points of the asphalt cements ranged from 174°C to 216°C
(345°F to 420°F), and the flash points ranged from 218°C to 338°C (424°F
to 640°F). In general, both the smoke point and the flash point were
lower for the softer asphalt cements used with RAP mixes than for the
asphalt cements used in conventional mixes.
4.4.8 Scrubber Water Analyses
During each sampling run, at least two scrubber influent and effluent
water samples were collected. The grab samples from each run were
composited and then filtered to determine total suspended solids. An
aliquot of the filtrate was analyzed for dissolved solids. The remaining
filtrate was analyzed for TOC, trace metals, and/or PAH. The average
dissolved solids, suspended solids, pH, and temperatures for the scrubber
water samples taken at Plants A and B are presented in Table 4-13.
Analytical problems were encountered with the scrubber water TOC
sample from Plant A, and these results are not reported. The TOC results
for the venturi scrubber influent and effluent water samples during
production of RAP mixes at Plant B are 968 and 985 milligrams per liter
(mg/£) (968 and 985 parts per million [ppm]), respectively.
The scrubber water PAH analysis is presented in Table 4-14 for
conventional and RAP mix test runs at Plant A. Polynuclear aromatic
hydrocarbons were found in trace amounts in the scrubber water during
both conventional and RAP operation.
4-28
-------
TABLE 4-13. AVERAGE SCRUBBER WATER ANALYTICAL MEASUREMENTS-
PLANTS A AND B16
Dissolved
solids,
mg/2 (ppm)
Suspended
solids,
mg/£ (ppm)
PH
Temp.,
°C (°F)
Conventional venturi
influent
Plant A
1,800
70
7.3 51 (124)
Conventional venturi
effluent
Plant A
Recycle venturi influent
Plant A
Plant B
Recycle venturi effluent
Plant A
Plant B
1,800
1,920
13,600
1,910
13,800
5,920
115
53
2,980
1,122
7.2
7.4
6.1
7.2
5.8
67 (153)
48 (119)
57 (135)
67 (152)
68 (155)
ppm = parts per million.
4-29
-------
TABLE 4-14. SCRUBBER WATER PAH ANALYSIS—PLANT A16
Conventional mix
Polynuclear hydrocarbon
Active carcinogenic
species. ug/A
Benz(a)anthracene
Chrysene
Benzo(b)f 1 uoranthene
Benzo( j )f 1 uoranthene
Benzo(e)pyrene
Benzo(a)pyrene
Indeno(l,2,3-c,d)-pyrene
Nonactive carcinogenic
species. ug/£
Phenanthrene
Anthracene
Fl uoranthene
Pyrene
Benzo(k)f 1 uoranthene
Perylene
Benzo(g , h , i )peryl ene
Run No.
Water to
venturi
<0.1
0.1
ND
ND
ND
ND
ND
10
0.4
0.6
1.4
ND
ND
ND
PAH Cl
Venturi
exit
water
<0.1
0.1
ND
ND
ND
ND
ND
6.8
ND
0.3
0.6
ND
ND
ND
RAP
Run No.
Water to
venturi
<0.1
0.1
ND
ND
ND
ND
ND
7.0
ND
0.7
1.3
ND
ND
ND
mix
PAH Rl
Venturi
exit
water
<0.1
0.1
ND
ND
ND
0.4
ND
5.0
ND
0.5
0.8
ND
0.5
ND
ND = Not detected.
4-30
-------
During conventional operation, phenanthrene and pyrene were found
at levels in excess of 1 part per billion (ppb). Three other species
(anthracene, fluoranthrene, and chrysene) were detected at levels of
less than 1 ppb. Benz(a)anthracene was detected but not at a quantifiable
level.
During RAP operation, phenanthrene and pyrene were the only species
found in excess of 1 ppb. Four other species (fluoranthene, perylene,
chrysene, and benzo(a)pyrene) were detected at levels less than 1 ppb.
The presence of benz(a)anthracene was detected but not at a quantifiable
level.
Polynuclear aromatic hydrocarbons were not detected in the scrubber
water samples collected at Plant B. Other major organic species quantified
in the scrubber water samples from Plant B are presented in Table 4-15.
The scrubber water trace metal analyses for both conventional and
RAP mix test runs at Plant A are presented in Table 4-16. There are no
significant differences between the scrubber influent and effluent trace
metals concentrations for either conventional or RAP operation. Calcium
and magnesium were the only species found in excess of 100 ppb.
The emissions at Plants C and D were controlled by baghouses and,
therefore, no water samples were obtained for analysis.
4-31
-------
TABLE 4-15. MAJOR ORGANICS IN SCRUBBER WATER AT PLANT B16
Major organic species, ug/m£
Phenol
Cresol
Methoxy phenol
C2-Phenol
Unknown
Unknown
C4-Benzene
C3-Phenol
Hydroxymethoxy-phenyl ethanone
Water to
venturl
670
97
60
46
75
60
120
106
106
Venturi
exit
water
870
200
54
69
44
NO
190
170
170
NO = Not detected.
4-32
-------
TABLE 4-16. SCRUBBER WATER TRACE METAL ANALYSIS—PLANT A16
Conventional mix
Trace metal
Element, MQ/m£
Al umi num
Beryllium
Calcium
Cadmi urn
Chromium
Iron
Mercury
Magnesium
Manganese
Nickel
Lead
Vanadium
Zinc
Run No.
Water to
venturi
<0.05
0.001
290
0.007
0.004
0.026
<0.03
54
0.047
<0.003
<0.08
0.069
<0.003
PAH Cl
Venturi
exit
water
<0.05
<0.005
300
<0.002
<0.001
< 0.008
<0.03
54
0.053
0.005
<0.084
<0.003
<0.003
RAP
Run No.
Water to
venturi
<0.05
<0.005
300
<0.002
<0.001
<0.008
<0.03
54
0.060
0.003
<0.084
<0.003
<0.003
mix
PAH Rl
Venturi
exit
water
<0.05
<0.005
300
<0.002
<0.001
<0.008
<0.03
53
0.061
<0.003
<0.084
<0.003
<0.003
4-33
-------
4.5 REFERENCES FOR CHAPTER 4
1. Trip report. Terry, W., MRI, to Telander, J., EPA:ISB. December 7,
1983. Report of visit to J. H. Strain and Sons Paving Company,
Sweetwater, Texas.
2. Trip report. Terry, W., MRI, to Telander, J., EPA:ISB. July 19,
1984. Report of visit to T. J. Campbell Construction Company, •
Oklahoma City, Oklahoma.
3. Trip report. Shular, J., MRI, to Telander, J., EPA:ISB. August 9,
1983. Report of visits to Mathy Construction Company, Neillsville,
Wisconsin.
4. Trip report. Terry, W., MRI, to Telander, J., EPA:ISB. August 28,
1984. Report of visit to ASTEC Industries, Inc., Chattanooga,
Tennessee.
5. National Asphalt Pavement Association. The Maintenance and Operation
of Exhaust Systems in the Hot Mix Batch Plant. Riverdale, Maryland.
1982. p. 26.
6. U. S. Environmental Protection Agency. A Review of Standards of
Performance for New Stationary Sources—Asphalt Concrete Plants.
EPA-450/3-79-014. Research Triangle Park, North Carolina p. 4-21.
7. Reference 5, pp. 29-30.
8. Reference 6, pp. 4-19.
9. U. S. Environmental Protection Agency. Inspection Manual for
Enforcement of New Source Performance Standards, Asphalt Concrete
Plants. EPA-340/1-76-003. Washington, D.C. p. 37.
10. The Mcllvaine Company. The Fabric Filter Manual, Volumes 1 and 2.
Northbrook, Illinois. September 1983. Ch. IX, pp. 124.4-124.5.
11. Reference 5, p. 23.
12. Reference 5, pp. 45-46.
13. Trip report. Shular, J., MRI, to Telander, J., EPArlSB. August 15,
1983. Report of visit to A. Metz, Inc. Valparaiso, Indiana.
14. Memo from Green, C., MRI, to 7707-L Project File. February 1,
1985. Compliance Test Reports Collected During NSPS Review.
15. Memo from Butler, J., to Telander, J., EPA/ISB. April 2, 1985.
Site Visit Tabulation.
16. Memo from Butler, J., to Telander, J. , EPA/ISB. January 18, 1985.
Asphalt Concrete Test Data Analysis.
4-34
-------
17. Telecon. Butler, J., MRI, with Miller, J., CMI Corporation.
June 25, 1985. Discussion of design specification.
18. Telecon. Bulter, J., MRI, with Shave, L., CMI Corporation.
June 18, 1985. Discussion of scrubber design specifications.
19. Telecon. Butler, J., MRI, with May, J., ASTEC Industries.
June 18, 1985. Discussion of scrubber design specifications.
4-35
-------
5. COST ANALYSIS
5.1 COST ANALYSIS OF EMISSION CONTROL DEVICES
The estimated costs of emission control devices for new or modified
asphalt concrete plants are presented in this chapter. The objective of
this analysis is to quantify the costs associated with two methods of
participate emission control. Model plant parameters were established
to represent the size range of facilities that have become subject to
the NSPS since the last review. Capital and annualized costs of
emission control equipment for the model plants were estimated using the
Capital and Operating Costs of Selected Air Pollution Control Systems
manual (in December 1977 dollars).1 These costs were updated to
September 1984 dollars using the Chemical Engineering fabricated
equipment cost index and indices from the Bureau of Labor Statistics.2-5
All costs are based on "study" estimates (±30 percent accuracy).
The capital cost of a control system includes the purchase and
installation costs of the major control device and necessary auxiliaries
such as fans and instrumentation; the cost of foundations, piping,
electrical wiring, and erection; and the cost of engineering overhead
and contingencies.1,2
The annualized cost of a control system represents the yearly cost
to the company of owning and operating the system. This includes direct
operating costs, such as labor, utilities, maintenance and replacement
parts, as well as capital related charges such as depreciation, interest,
administrative overhead, property taxes, insurance, and
product recovery credits.1,2
5-1
-------
The estimated capital and annualized costs of emission control
equipment are presented in Section 5.2. A comparison of the estimated
and reported capital costs is presented in Section 5.3. Cost
effectiveness of emission control is presented in Section 5.4.
5.2 ESTIMATED CAPITAL AND ANNUALIZED COSTS OF EMISSION CONTROL
Estimated capital and annualized costs are presented for three
sizes of model asphalt concrete plants with operating hours per year
representing year-round and seasonal operation. The capital and
annualized costs are for two emission control devices, a fabric filter
and a wet scrubber.
5.2.1 Fabric Filters
Small, medium, and large model asphalt concrete plants were
developed to evaluate the cost of emission control by fabric filters on
plants installed since September 1984. Parameters describing the model
plants and emission control equipment are presented in Table 5-1. The
fabric filter emission control system is composed of the fabric filter
with pulse-jet cleaning, ductwork (ducts, elbows, damper), induced-draft
fan system (fan, motor, V-belt drive, starter, damper), and stack. The
exhaust gas flow rate is the critical parameter for costing this type of
control device. Exhaust gas flow rates were developed using reported
air flow data from industry in combination with design data from control
equipment manufacturers.7
Table 5-2 presents the estimated capital and annualized costs of
fabric filter control devices for the three model plants in
September 1984 dollars. The capital cost of fabric filters for the
three model plants ranged from $239,000 to $567,000. The annualized
cost of fabric filters for the the three model plants ranged from
$56,000 to $115,000 for 1,000 h/yr (seasonal) operation and from $61,000
to $119,000 for 1,500 h/yr (year-round) operation.
Table 5-3 presents cost factors used in calculating the annualized
costs.
5.2.2 Wet Scrubbers
The capital and annualized costs of wet scrubber control devices
were also developed for the three model plants. Parameters describing
the plants and emission control equipment are presented in Table 5-1.
5-2
-------
The wet scrubber emission control system is composed of a 20-in.
w.c. pressure drop, venturi-type scrubber (elbow, separator, pumps,
controls), ductwork (ducts, elbows), wastewater disposal pipe, fan
system (fan, motor, starter, V-belt drive, damper), and stack. The
exhaust gas flow rate and scrubber water flow rate are critical
parameters for costing this type of control device. Exhaust gas and
water flow rates were developed using reported airflow data from industry
in combination with design data from control equipment manufacturers.7
Table 5-2 presents the estimated capital and annualized costs of
wet scrubber control devices (excluding continuous monitor costs) for
the three model plants in September 1984 dollars. The capital cost of
venturi scrubbers for the three model plants ranged from $156,000 to
$334,000. The annualized cost of venturi scrubbers for the three model
plants ranged from $46,000 to $96,000 for 1,000 h/yr operation and from
$54,000 to $111,000 for 1,500 h/yr operation.
Table 5-3 presents the cost factors used in calculating the
annualized costs.
5.3 COMPARISON OF ESTIMATED AND REPORTED CAPITAL COST DATA
Capital cost data obtained from individual asphalt concrete plants
and from vendors were converted to September 1984 dollars for comparison
with the estimated capital cost data presented in Section 5.2.8-10
Table 5-4 presents the estimated and reported costs by plant size and
type of control equipment.
5.4 ESTIMATED CAPITAL AND ANNUALIZED COSTS OF CONTINUOUS PRESSURE DROP
AND LIQUID FLOW RATE MONITORS
The pressure drop (AP) across a wet scrubber and the scrubber water
flow rate are two control device parameters that can be used as indicators
of how well the control device is operating. In the asphalt concrete
industry, these parameters are generally not continuously monitored.
However, in the event that a plant were to install and operate continuous
monitors, estimates of the capital and annualized costs of these monitors
are presented here. The capital and annualized costs of a wet scrubber
monitoring system (manometer, flowmeter, recorder) would be $2,903 and
$750, respectively. These costs are presented in Table 5-5.
5-3
-------
5.5 COST EFFECTIVENESS
Tables 5-6a and 5-6b present the cost effectiveness of wet scrubber
(including continuous monitors) and fabric filter control devices on
each of the three model plants for seasonal operation (1,000 h/yr) and
year-round operation (1,500 h/yr)7. Cost effectiveness is the annualized
cost of emission control divided by the annual emission reduction. The
NSPS (allowable) particulate emissions were calculated for each model
plant using the allowable NSPS concentration, the airflow into the
device and the seasonal and year-round hours of operation.1 Uncontrolled
emissions, which were assumed to be those entering the fabric filter or
wet scrubber, were calculated using an emission factor of 4.9 lb/ton.7
The annual emission reduction is calculated as uncontrolled emissions
minus NSPS (allowable) emissions.
For seasonal operation, the cost effectiveness of controlling
emissions from model plants with a fabric filter control device ranges
from $130 to $253 per Mg ($118 to $230 per ton). With a wet scrubber
control device (including continuous AP and liquid flow rate monitors),
the cost effectiveness of emission control ranges from $108 to $213 per
Mg ($99 to $194 per ton). For year-round operation, the cost effec-
tiveness of control for fabric filters ranges from $89 to $183 per Mg
($81 to $168 per ton). For wet scrubbers with monitors, the cost effec-
tiveness of control ranges from $84 to $166 per Mg ($76 to $151 per
ton).
5-4
-------
TABLE 5-1. SUMMARY OF ASPHALT CONCRETE MODEL PLANT PARAMETERS
in
en
Model plant
Size
I. Fabric filter control
A. Small
B Medium
Production
rate, Mg/h
(tons/h)a
91 (100)
277 (250)
Exhaust gas
flow rate, K
mVmin (acfm)0
566 (20,000)
1,133 (40,000)
Gas
temp.
inlet/
outlet
°C (°F)
163 (325)
163 (325)
Water
flow rate,
C/min (gpro)
N/A
N/A
Pressure
in. w.c. Other parameters
4.5 For all fabric filter-controlled
facilities:
4.5 Air-to-cloth ratio 6:1; 1.000
h/yr
C. Large 363 (400) 1,756 (62,000)' 163 (325)
II. Venturi scrubber control
N/A
A. Small
91 (100) 566 (20,000) 163 (325) 628
71 (160) (166)
4.5
20
and 1.500 h/yr operation; Nomex
bags; pulse jet cleaning; value
of mineral filler for product
recovery credit $10/ton.
For all venturi scrubber-controlled
facilities:
scrubber efficiency = >99%;
liquid to gas ratio =
3.1 xlO-2 mJ/28 mj-m-1
(8.3 gpm/1.000 acfm)
B Medium
C. Large
227 (250)
363 (400)
1,133 (40,000)
1,756 (62,000)
163 (325)
71 (160)
163 (325)
71 (160)
1257
(332)
1950
(515)
20
20
N/A = Not applicable.
jJMegagrams (tons) of asphalt produced per hour.
nrvmin = actual cubic meters per minute; acfm = actual cubic feet per minute.
(|C/mm = liters per minute; gpra = gallons per minute.
in w c. = inches water column.
-------
TABLE 5-2. ESTIMATED CAPITAL AND ANNUALIZED COSTS OF
PARTICULATE EMISSION CONTROL EQUIPMENT2
Model asphalt plant
I. Fabric filter control
A
B
C
II. Wet scrubber control
A
B
C
Model
facility size
Small
Medium
Large
Small
Medium
Large
Capital
cost, $
239,000
386,000
567,000
156,000
269,000
334,000
Annual i zed
cost, $a
(seasonal/
yearr
round)
56,0007
61,000
80,0007
84,000
115,0007
119,000
46,0007
54,000
76,0007
87,000
96,0007
111,000
["September 1984 dollars rounded to nearest thousand.
Hours of operation: 1,000 h/yr (seasonal); 1,500 h/yr (year-round).
5-6
-------
TABLE 5-3. COST FACTORS USED IN CALCULATING THE ANNUALIZED COSTS2
Cost item Wet scrubber Fabric filter
Operating labor
Operator $9.81/h $9.81/h
Supervisor «- 15% of operator labor • •*
Maintenance
Maintenance labor $9.81/h $9.81/h
Materials «• 100% of maintenance labor *
Utilities
Electricity $0.06/kWh $0.06/kWh
Water cost $3.00/1,000 gal N/A
Water use 0.50 gpm/1,000 gal N/A
Credit for mineral filler 0 $10/ton
N/A = not applicable.
5-7
-------
TABLE 5-4. COMPARISON OF ESTIMATED CAPITAL COST OF
EMISSION CONTROL WITH REPORTED CAPITAL COST DATA
Model facility control device
Fabric filter
A. Small
B. Medium
C. Large
Wet scrubber
A. Smal 1
B. Medium
C. Large
Capital
Estimated
239,000
386,000
567,000
156,000
269,000
334,000
cost, 1984 $ '
Reported
370,000
412,000
561,000
101,000
204,000
273,000
% b
Difference
-54.8
-6.7
1.1
35.3
24.2
18.3
Average reported control device capital costs from industry. Reported
costs are installed costs of control systems (assumed to include the
cost of the control device and all auxiliaries) for new plant construc-
. tion and installation.
% omerence , ,.t1«Ud rtrrrud cost „ 10Q
5-8
-------
TABLE 5-5. ESTIMATED CAPITAL AND ANNUALIZED COSTS OF CONTINUOUS
PRESSURE DROP AND LIQUID FLOW RATE MONITORS3,11-13
(September 1984 Dollars)
Wet scrubber
I. Capital Cost Estimates of Continuous Monitors
A. Flowmeter
Impeller/sensor = $168
Transmitter/display/totalizer = 309
Output transmitter for records = 262
1739
B. Manometer
Sensor/transmitter = $739
C. Chart/recorder
Two-pen recorder = $1.425
TOTAL $2,903
II. Annualized Cost of Continuous Monitors
Recordkeeping (5 min/d, 6 d/wk 25 wk/yr)a = $136
Maintenance labor (4 h/yr) = 84
Maintenance parts and supplies = 58
(pens, charts, etc.)
Capital recovery cost (16^275 percent of = 472
equipment capital cost)
TOTAL ANNUALIZED COST $750
?Assumes 6 months of plant operation per year.
Assume 2 percent of equipment capital cost.
Based on 10 percent annual interest rate and 10 year capital recovery
period.
5-9
-------
TABLE 5-6a. COST EFFECTIVENESS OF PARTICULATE EMISSION REDUCTION
(Seasonal Operation, 1,000 h/yr)
en
i
Control
device
Facility
size,
Mg/h a
(tons/h)a
Control
device
annual i zed
cost,
$/yr°
Parti cul ate
emissions,
Mg/yr (tons/yr)
Uncon-
trolled
NSPS
equivalent
Emission
reduction
Mg/yr
(tons/yr)
Cost
effectiveness^
$/Mg
($/tonr
I. Fabric filter
A.
B.
C.
II. Wet
A.
B.
C.
Small
Medium
Large
scrubber
Small
Medium
Large
91
(100)
227
(250)
363
(400)
91
(100)
227
(250)
363
(400)
56,000
80,000
115,000
47,000
76,000
96,000
222
(245)
555
(612)
890
(981)
222
(245)
555
(612)
890
(981)
1.51
(1.66)
3.01
(3.32)
4.67
(5.15)
1.51
(1.66)
3.01
(3.32)
4.67
(5.15)
221
(243)
552
(609)
885
(975)
221
(243)
552
(609)
895
(975)
253
144
130
213
138
108
(230)
(132)
(118)
(194)
(125)
(99)
. Megagrams (tons) of asphalt produced per hour.
September 1984 dollars rounded to nearest thousand. Annualized cost to operate wet scrubber includes
cost continuous AP and liquid flow rate monitors.
Annualized cost numbers in table may not yield exact cost effectiveness shown
Emission reduction* due to rounding of annualized cost.
"Cost effectiveness =
-------
TABLE 5-6b. COST EFFECTIVENESS OF PARTICIPATE EMISSION REDUCTION
(Year-round Operation, 1,500 h/yr)
Control
device
Facility
size,
Mg/h a
(tons/h)a
Control
device
annuali zed
cost,
$/yrD
Parti cul ate
emissions,
Mg/yr (tons/yr)
Uncon-
trolled
NSPS
equivalent
Emission
reduction
Mg/yr
(tons/yr)
Cost
effectiveness,.
$/Mg
($/ton)~
I. Fabric filter
A.
B.
C.
II. Wet
A.
B.
C.
Small
Medium
Large
scrubber
Small
Medium
Large
91
(100)
227
(250)
363
(400)
91
(100)
227
(250)
363
(400)
61,000
84,000
119,000
55,000
87,000
111,000
333
(367)
621
(685)
995
(1097)
333
(367)
621
(685)
995
(1097)
2.26
(2.49)
4.51
(4.98)
7.00
(7.72)
2.26
(2.49)
4.51
(4.98)
7.00
(7.72)
331
(365)
828
(913)
1,327
(1,463)
331
(365)
828
(913)
1,327
(1,463)
183
101
89
166
106
84
(168)
(93)
(81)
(151)
(96)
(76)
. Megagrams (tons) of asphalt produced per hour.
September 1984 dollars rounded to nearest thousand.
AP and liquid flow rate monitors.
Cost of wet scrubber includes cost for continuous
rn<:t
Lost
Annual j zed cost numbers in table may not yield exact cost effectiveness shown
Emission reduction* due to rounding of annual ized cost.
-------
5.6 REFERENCES FOR CHAPTER 5
1. Neveril, R. B. Capital and Operating Costs of Selected Air Pollution
Control Systems. CARD, Inc. Prepared for the U. S. Environmental
Protection Agency. Publication No. EPA-450/5-80-002. December 1978.
2. Memo from Green, C., MRI, to Telander, J., EPA/ISB. January 31,
1985. (Revised April 19, 1985.) Capital and annualized costs of
emission control devices for asphalt concrete plants.
3. Economic Indicators. Chemical Engineering. December 24, 1984.
p. 7.
4. Employment and Earnings. U.S. Department of Labor. Bureau of
Labor Statistics. December 1984. pp. 83-85.
5. Producer Prices and Price Indexes Data for September 1984. U.S.
Department of Labor. Bureau of Labor Statistics. September 1984.
pp. 109, 130, 133, 134.
6. Telecon. Green, C., MRI, to Waller, M. F., The Asphalt Paving
Institute, Raleigh, North Carolina. January 17, 1985. Discussion
of the cost of mineral filler material used in the aggregated mix
of an asphalt concrete plant.
7. Memo from Butler, J. and Green, C., MRI, to Telander, J., EPA/ISB.
March 27, 1985. Final Model Plant Parameters—Asphalt Concrete
NSPS Review.
8. Report of Visit—ASTEC Industries, Inc., Chattanooga, Tennessee.
Terry, W., to Telander, J., EPA/ISB. August 28, 1984. Asphalt
Concrete NSPS Review.
9. Report of Visit—Iowa Manufacturing Co., Cedar Rapids, Iowa.
Maxwell, W., to Telander, J., EPA/ISB. September 20, 1983. Asphalt
Concrete NSPS Review.
10. Telecon. Cooper, R., MRI, to Krattenmaker, L., Barber-Greene
Company. January 5, 1984. Discussion of cost information for
small, medium, and large asphalt concrete plants.
11. Telecon. Shular, J., MRI, with Kent Process Control, Inc. March 8,
1983. Cost of chart recorder.
12. Telecon. Shular, J., MRI, to K. Nile, W. K. Mile Company, Inc.
March 8, 1983. Cost of continuous monitors.
13. Leter from K. Nile, W. K. Nile Company, Inc., to J. Shular, MRI.
February 24, 1983. Cost of continuous monitors.
5-12
-------
6. ENFORCEMENT ASPECTS
6.1 ENFORCEMENT
This chapter presents enforcement aspects of the asphalt concrete
new source performance standards (NSPS). These are grouped under four
main headings: reciprocity waivers, process parameters, control
equipment, and visible emissions.
6.1.1 Reciprocity Waivers
Data collected during this review indicate that a number of
operating and maintenance factors, in addition to design parameters,
affect the performance of an asphalt concrete plant and its associated
air pollution control equipment. For this reason, two individual plants
of the same make and model may not have the same emission level.
Demonstration of compliance with the NSPS by a particular plant should
not be used by itself to justify waiving the requirement that a second
plant of the same type conduct a performance test.
6.1.2 Process Parameters
As discussed in Chapter 4, process parameters that influence
emissions from an asphalt concrete plant are the production rate, the
type mix produced, the fuel used for the dryer, and the final product
temperature.
6.1.2.1 Production Rate. The survey of test reports collected
during this NSPS review indicates that approximately half of the asphalt
concrete plants operated at less than 80 percent of their design
capacity during compliance testing. Plants that demonstrate compliance
with the NSPS when operated below full capacity may be out of compliance
when operated at higher production rates. This is especially true for
plants that use wet scrubber as control devices. In addition, conducting
6-1
-------
compliance tests at production rates that are much less than the design
capacity will result in emission data that are not representative of
normal operation.
As an example, Plant B, discussed in Chapter 4, was tested for
compliance with the NSPS at a production rate of 163 tons per hour (tph)
and had emissions of 0.02 grains per dry standard cubic foot (gr/dscf).
When tested by the EPA at a production rate of 196 tph, the same plant
had emissions of 0.13 gr/dscf. This increase in emissions is attributed
to the increased production rate and the manner in which the scrubber
was operated during the test. Assuming the plant operates 1,500 hours
per year, the difference in emissions from these two tests is 12 tons
per year. Therefore, it is recommended that NSPS performance tests be
conducted at or near full production capcity.
6.1.2.2 Mix Type. As discussed in detail in Chapter 4, mixes that
require a large amount of fine material result in more entrained material
in the exhaust gas stream from the dryer drum than do mixes containing
small amounts of fine material. Surface mixes generally require more
fine material than base mixes. Production of a surface mix, therefore,
results in more particulate matter in the exhaust gas stream from the
dryer drum and a greater loading on the control device than does
production of a base mix. Asphalt concrete plants produce both surface
and base mixes during normal operation. The practice of testing
predominantly during base mix production will not result in testing of
the control device under the heaviest concentration of fine materials.
Scrubber operation is especially sensitive to the inlet concentration of
fine materials. Therefore, it is recommended that NSPS performance
tests be conducted during production of a surface mix.
6.1.2.3 Fuel. The most common fuels used at asphalt concrete
plants are fuel oil and natural gas. A very limited number of plants
have experimented with pulverized coal as a fuel. During the present
NSPS review, only three test reports were available for plants using
coal as a fuel.2,3 All of these plants were fabric filter-controlled
and 2 of the 3 had particulate emissions greater than 90 mg/dscm
(0.04 gr/dscf). One of these two plants was retested while using fuel
oil as a fuel and met the NSPS.2 The other plant has not been retested
6-2
-------
at this time. The third plant demonstrated participate emissions of
23 to 30 percent of the NSPS.3
The use of coal as a fuel is a recent development in the asphalt
concrete industry, and the Agency did not find any existing plants that
were originally designed to use coal during this review. Emission
control equipment designed to reduce particulate emissions from oil- or
gas-fired plants may not be adequately designed or operated to achieve
the NSPS emission limit while firing coal. Therefore, operators of
asphalt concrete plants need to be aware that conversion from oil or gas
to coal may require a change in design or operation to meet the NSPS.
Any existing plant not presently subject to the NSPS that switches from
gas or oil to coal fuel would be a modified facility.4 Such a plant
would be required to conduct an emission test to demonstrate compliance
with the NSPS or to demonstrate that conversion to coal firing does not
increase particulate emissions to the atmosphere.
Any existing plant already subject to the NSPS would also have to
demonstrate compliance with the standards if it were to switch from oil
or gas to coal firing.
6.1.3 Control Equipment
The pressure drop (AP) across fabric filters used in the asphalt
concrete industry is typically 1.0 to 1.6 kilopascals (kPa) (4 to
6.5 inches water column [in. w.c.]). If the AP rises above this level,
"blinding" of the bags may occur. A AP below normal may indicate tears
or leaks in the fabric filter or overcleaning of the bags.
Most venturi scrubbers used in the asphalt concrete industry are
designed to operate at a AP of 3.8 to 5.0 kPa (15 to 20 in. w.c.).5,6
Operation at a lower AP, as is frequently done, will reduce the
efficiency of the scrubber.
The wet scrubber liquid to gas ratio (L/G) recommended by asphalt
plant manufacturers ranges from 1.1 to 1.3 liters per cubic meter (A/m3)
[8 to 10 gallons per 1,000 actual cubic feet (gal/1,000 acf)].7-10
Operation at a lower L/G ratio will reduce the efficiency of the
scrubber.
Since many scrubbers in the asphalt concrete industry use water
that is recycled through a settling pond, water quality and pond size
6-3
-------
are closely related. The purpose of the settling pond is to remove
suspended solids from the water.
A minimum pond size equal to half the daily flow rate (assuming an
8-hour day) has been recommended by one equipment vendor and by the
National Asphalt Pavement Association as proper design to achieve
adequate settling.5,11 It should be noted that this is only a minimum,
and, in cases where very fine particulate is present or where a work day
longer than 8 hours is practiced, this minimum may not be adequate. The
water depth of the pond must also be closely monitored to prevent the
pond volume from decreasing as a result of sludge buildup or evaporation
of the water.
Several chemical aids are available to maintain water quality.
Lime can be used to keep the pH of the water from dropping, and various
flocculants can be used to aid in the settling of suspended solids. It
should be noted that, while flocculants aid particulate settling, they
should not be expected to compensate for an inadequate pond size. One
equipment manufacturer recommends a maximum suspended solids
concentration of 500 parts per million (ppm) and a minimum pH of 5.5
Excess dissolved solids in the scrubber water may decrease the
efficiency of a scrubber. However, this parameter is not typically
monitored, and guidelines on what dissolved solids level is "excessive"
are not available.5 One method of controlling dissolved solids is to
replace a portion of the scrubber pond water with fresh water
periodically.
6.1.4 Blue Haze Emissions
As discussed in Chapter 4, approximately half of the plants visited
reported the presence of blue haze emissions during production of
recycled mix. The blue haze generally developed downwind of the plant
rather than at the stack vertex. No blue haze emissions in excess of
20 percent opacity were observed during the plant visits or emissions
testing program. Observers of visible emissions during NSPS performance
tests should note that condensing emissions that develop downwind of the
plant are not included in the Method 9 observations.
6-4
-------
6.1.5 Visible Emissions
The present NSPS for asphalt concrete plants includes a visible
emission standard of 20 percent opacity. Visible emission readings are
often difficult to make at a scrubber-controlled plant due to the
presence of an attached steam plume. Steam plumes are sometimes
observed at plants controlled by fabric filters; however, these plumes
are usually detached and not as dense as those observed at scrubber-
controlled plants. EPA Reference Method 9 specifies that visible
emissions should be evaluated between the stack and the steam plume for
detached plumes, or after disappearance of the steam plume for attached
plumes. Visible emissions are, therefore, usually read at the stack
vertex at fabric filter-controlled plants and downstream of the steam
plume at scrubber-controlled plants. After the disappearance of the
steam plume, the remaining plume is lightened by dispersion. In
contrast, the blue haze sometimes observed with RAP mixes appears to
darken as the plume cools and moves away from the stack. Because of
these interferences, the opacity of visible emissions in a scrubber
exhaust plume may not be a consistent indicator of the performance of
the scrubber.
As discussed in Chapter 4, the test reports collected during this
NSPS review indicate a high non-compliance rate for scrubber-controlled
plants. These test reports and discussions with plant personnel suggest
that wet scrubber performance is often allowed to deteriorate by
operating at a AP and liquid flow rate below the levels necessary to
meet compliance. For the reasons just discussed, visible emissions may
not be a consistent indicator of this deterioration in performance.
Monitoring of AP and liquid flow rate to supplement visible emissions
would provide a better indication of proper operation and maintenance
for plant and enforcement personnel. Operation of a wet scrubber at AP
and liquid flow rate levels below those recorded during successful
compliance testing would indicate a potential decrease in scrubber
performance and an increase in emissions.
6-5
-------
6.2 REFERENCES FOR CHAPTER 6
1. Trip report. Butler, J., MRI, to Glowers, M., EPA:ISB. April 17,
1984. Report of visit to Sloan Construction Company, Ormond Beach,
Florida.
2. Letter and attachments from Andrews, D., Kentucky Division of Air
Pollution Control, to Butler, J., MRI. January 30, 1985. Three
compliance tests on two coal-fired asphalt plants.
3. Letter and attachments from Sprouse, S. M., ASTEC Industries, Inc.
March 26, 1985. Emission test report and production literature.
4. Memorandum from Reich, E. E., EPA, to Wilburn, J. T., EPA.
April 4, 1985. Asphalt Concrete Plant NSPS Determination.
5. Telecon. Butler, J., MRI, with Wagner, L., ASTEC Industries, Inc.
October 8, 1984. Design and operating parameters for scrubber and
baghouse controlled asphalt concrete plants.
6. National Asphalt Pavement Association. The Maintenance and
Operation of Exhaust Systems in the Hot Mix Batch Plant.
Information Series 52 (2nd edition) and 52A (combined volumes).
College Park, Maryland. February 1980. pp. 26.
7. Telecon. Butler, J., MRI, with May, J., ASTEC Industries, Inc.
June 18, 1985. AP and L/G requirments for scurbber-controlled
plants.
8. Telecon. Butler, J., MRI, with Binz, L., Barber-Greene Co., Inc.
June 18, 1984. AP and L/G requirements for scrubber-controlled
plants.
9. Telecon. Butler, J., MRI, with Shaves, L., CMI Corporation
June 18, 1984. AP and L/G requirements for scrubber-controlled
plants.
10. Telecon. Butler, J., MRI, with Linkletter, D. Iowa Mfg. Co.
June 18, 1984. AP and L/G requirments for scrubber-controlled
plants.
11. Reference 6, pp. 6A.
6-6
-------
APPENDIX A
EMISSION SOURCE TEST DATA
The test results from EPA-conducted emission tests for four asphalt
concrete plants are presented in this appendix. These test results
include data that were excluded from Table 4-6 in Chapter 4 and the
reasons for their exclusion.
A.I Description of Sources
A brief description of the four plant sites tested and the operating
conditions of the process unit and control device at each plant site is
presented in this section.
A. 1.1 Plant A
Plant A ts a venturi-scrubber controlled drum-mix plant. Tests
were conducted during production of both conventional and approximately
25 percent recycled asphalt pavement (RAP) mixes. Plant A has a design
capacity range of 227 to 318 megagrams/hour (Mg/h) [250 to 350 tons/hour
(tons/h)] and typically operates at approximately 218 Mg/h (240 tons/h).
During testing the plant production averaged 204 Mg/h (232 tons/h) of
conventional mix and 218 Mg/h (240 tons/h) of RAP mix. The pressure
drop (AP) across the venturi averaged 3.23 kilopascals (kPa) [13.65 inches
water column (in. w.c.)] and the liquid-to-gas ratio averaged 0.017 gallons
per standard cubic foot (gal/scf) during testing.
The particulate and total organic carbon (TOC) emission test results
for Plant A are presented in Tables A-l through A-4. The total organic
carbon samples from Plant A were originally analyzed by an unapproved
method (TOC-1) that resulted in the inclusion of inorganic carbon in the
reported TOC values. These are the values presented in Tables A-l
through A-4. These samples were also analyzed by an ether/chloroform
A-l
-------
extraction method (ECE or extractable organics). The samples were
reanalyzed by the TOC-1 method and by the approved Method 5E analysis
method (TOC-2) when the samples were approximately 9 months old. The
TOC-1 analysis indicated that the samples had deteriorated during this
9-month period. The results of these analyses are presented in Table A-5.
Due to these problems in testing methodology and analytical procedures,
the TOC results from Plant A were not used in this study. The extractable
organic results (ECE) were also not used in this study because they are
not directly comparable to TOC results obtained using a different analysis
method.
The visible emissions observed at Plant A are described in Tables A-6
through A-8 and in Figures A-l through A-3. The highest single reading
was 10 percent and the highest 6-minute average ranged from 1.5 percent
to 5.8 percent for the three test runs during which visible emissions
were observed.
A.1.2 Plant B
Plant B is a venturi-scrubber controlled, portable, drum-mix plant.
Tests were conducted only during production of approximately 50 percent
RAP mixes. Plant B has a design capacity of 229 Mg/h (252 tons/h) at
5 percent moisture removal. During testing the plant averaged 181 Mg/h
(199 tons/h). The AP across the venturi averaged 4.67 kPa (19 in.
w.c.), and the liquid-to-gas ratio averaged 0.021 gal/scf during testing.
The particulate and TOC emission test results for Plant B are
presented in Tables A-9 and A-10. The visible emissions observed at
Plant B are described in Tables A-ll through A-14 and in Figures A-4
through A-7. The highest single reading was 25 percent and the highest
6-minute average ranged from 11.9 percent to 17.5 percent for the 4 test
runs during which visible emissions were observed.
A. 1.3 Plant C
Plant C is a baghouse-controlled, stationary drum-mix plant. Tests
were conducted during production of both conventional mix and approxi-
mately 28 percent RAP mixes. Plant C has a design capacity of 386 Mg/h
(425 tons/h) at 5 percent moisture removal. The design air-to-cloth
ratio was 5.6 acfm/ft2. During testing the plant production averaged
217 Mg/h (239 tons/h) of conventional mix and 310 Mg/h (342 tons/h) of
A-2
-------
RAP mix. The AP across the baghouse averaged 1.3 kPa (5.1 in. w.c.)
during production of conventional mix and 1.0 kPa (4.0 in. w.c.) during
production of RAP mix.
The particulate and TOC emission test results for Plant C are
presented in Tables A-15 through A-18. The TOC samples collected at
Plant C were contaminated with an organic solvent used to clean the
impinger walls. Therefore, the TOC results from Plant C were not used
in this study.
The visible emissions observed at Plant C are described in Tables A-19
through A-27 and in Figures A-8 and A-9. As discussed in Chapter 4,
field data sheets from Plant C indicate that some or all of the opacity
readings at Plant C were made within the steam plume; therefore, these
values were not used in this study.
A.1.4 Plant D
Plant D is a baghouse-controlled, portable drum-mix plant. Tests
were conducted during production of both conventional and approximately
50 percent RAP mixes. Plant D has a design capacity of 391 Mg/h
(430 tons/h) at 5 percent moisture removal and typically operates at
273-318 Mg/h (300-350 tons/h). The design air-to-cloth ratio was
6.3 acfm/ft2. During testing the plant production averaged 271 Mg/h
(299 tons/h) of conventional mix and 288 Mg/h (317 tons/h) of RAP mix.
The AP across the baghouse averaged 1.4 kPa (5.6 in. w.c.) during
production of conventional mix and 1.2 kPa (4.7 in. w.c.) during
production of RAP mix.
The particulate and TOC emission test results for Plant D are
presented in Tables A-28 through A-31. The visible emissions observed
at Plant D are described in Tables A-32 and A-33 and in Figures A-10 and
A-11. Visible emissions were observed during one conventional-mix test
run and during one RAP-mix test run. During production of conventional
mix the highest single reading was 5 percent and the highest 6-minute
average was 1.25 percent. During production of RAP mix the highest
single reading was 5 percent and the highest 6-minute average was
5.0 percent.
A-3
-------
A.2 Summary of Test Data
The EPA-conducted and EPA-approved test data are summarized in this
section. Metric/English conversions and test series averages may not
convert exactly due to independent rounding of data.
A-4
-------
TABLE A-l. SUMMARY OF UNCONTROLLED EMISSION TEST RESULTS—PLANT A—
CONVENTIONAL MIX PROCESS UNIT: DRUM PLANT MIX
Data
General
Date
Sampling tine, nin
Isoklnetlc ratio, percent
Production rate. Mg/h
(tons/h)
Gas stream data
Temperature, °C
Moisture, percent
Flow rate, ra3/s
(acfn)
Flow rate, dsmVs
(dscfra)
Parti cul ate emissions
ng/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Total Organic Carbon-- TOC
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Run No. C-l
11/12/83
48
109.9
221
(244)
147.6
(297.6)
38.01
13.46
(28,523)
5.52
(11,699)
17,400
(7.6)
96.1
(762)
1.56
(3.12)
470
(0.205)
2.59
(20.5)
0.042
(0.0840)
Run No. C-2
11/13/83
48
113.3
213
(235)
142.7
(288.8)
39.6
13.68
(28.974)
5.53
(11.724)
19,400
(8.49)
115
(910)
1.935
(3.87)
995
(0.434)
5.50
(43.6)
0.093
(0.186)
Run No. C-3 Run No.
11/13/83
48
103.8
193
(213)
150.9
(303.6)
36.71
14.31
(30,312)
5.91
(12,516)
12.800
(5.58)
75.5
(599)
1.405
(2.81)
681
(0.297)
4.01
(31.8)
0.0745
(0.0149)
Average
for test
series
--
--
--
210
(231)
147.1
(296.7)
38.11
13.82
(29,269.7)
5.65
(11,980)
16,500
(7.22)
95.5
(757)
1.635
(3.27)
715
(0.312)
4 03
(32.0)
0 0695
(0.139)
A-5
-------
TABLE A-2. SUMMARY OF CONTROLLED EMISSION TEST RESULTS—PLANT A—
CONVENTIONAL MIX PROCESS UNIT: DRUM PLANT MIX
Data
General
Date
Sampling time, rain
Isoklnetic ratio, percent
Production rate, Mg/h
(tons/h)
Gas stream data
Temperature, °C
Moisture, percent
Flow rate, m'/s
(acfm)
Flow rate, dsmVs
(dscfm)
Parti cul ate emissions
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Total Organic Carbon--TOC
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Run No. C-l
11/12/83
96
105
221
(244)
70.4
(158.7)
34.29
10.03
(21,255)
5.37
(11,367)
126
(0.0550)
0.697
(5.53)
0.0113
(0.0226)
122
(0.0532)
0.697
(5.34)
0.0110
(0.0219)
Run No. C-2
11/13/83
96
100.3
213
(235)
68.2
(154.8)
32.26
9.69
(20,533)
5.38
(11,400)
186
(0.0814)
1.05
(8.29)
0.0177 •
(0.0353)
319
(0.139)
1.05
(14.2)
0.0302
(0.0604)
Run No. C-3 Run No.
11/14/83
96
101.8
193
(213)
67.0
(152.6)
29.73
9.71
(20,579)
5.57
(11,811)
76
(0.0332)
0.435
(3.45)
0.0081
(0.0162)
296
(0.129)
0.435
(13.4)
0.0315
(0.0629)
Average
for test
series
—
--
--
210
(231)
68.5
(155.4)
32.09
9.81
(29,789)
5.44
(11,526)
129
(0.0565)
0.726
(5.76)
0.0124
(0.0247)
245
(0.107)
0.726
(11.0)
0.0238
(0.0476)
A-6
-------
TABLE A-3. SUMMARY OF UNCONTROLLED EMISSION TEST RESULTS-PLANT A—
RAP MIX PROCESS UNIT: DRUM PLANT MIX
Data
General
Date
Sampling time, min
Isokinetic ratio, percent
Production rate, Mg/h
(tons/h)
Gas stream data
Temperature, °C
/oe\
Moisture, percent
Flow rate, m3/s
(acfm)
Flow rate, dsmVs
(dscfm)
Parti cul ate emissions
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Total Organic Carbon—TOC
mg/dscm
(gr/dscf)
9/s
(Ib/h)
kg/Mg
(Ib/ton)
Run No. R-l
11/11/83
48
94.8
208
(229)
146.8
(296.2)
24.44
13.8
(29,241)
6.98
(14,797)
7,420
(3.24)
51.8
(411)
0.895
(1.79)
1,030
(0.448)
7.16
(56.8)
0.124
(0.248)
Run No. R-2
11/11/83
42
116.9
227
(250)
156.4
(313.6)
31.48
12.9
(27,367)
5.79
(12.275)
10,000
(4.37)
62.9
(499)
1.00
(2.00)
1,500
(0.655)
8.71
(69.1)
0.138
(0.276)
Run No. R-3 Run No.
11/12/83
48
110.6
214
(236)
158.3
(317.0)
27.74
14.2
(30,060)
6.61
(14,012)
8.590
(3.75)
59.8
(474)
1.005
(2.01)
1,160
(0.504)
7.63
(60.5)
0.128
(0.256)
Average
for test
series
--
~
—
216.3
(238.3)
153. 8
(308.9)
27.89
13.6
(28,889)
6.46
(13,695)
8,670
(3.79)
58.2
(461)
0.97
(1.94)
1,230
(0.536)
7.83
(62.1)
0.131
(0.261)
A-7
-------
TABLE A-4. SUMMARY OF CONTROLLED EMISSION TEST RESULTS—PLANT A~
RAP MIX PROCESS UNITS: DRUM PLANT MIX
Data
General
Date
Sampling time, n1n
Isoklnetlc ratio, percent
Production rate, Mg/h
(tons/h)
Gas stream data
Temperature, °C
Moisture, percent
Flow rate, ms/s
(acfm)
Flow rate, dsmVs
(dscfm)
Partlculate emissions
mg/dscm
(gr/dscf)
9/s
(Ib/h)
kg/Mg
(Ib/ton)
Total Organic Carbon—TOC
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Run No. R-l
11/11/83
93
104.5
208
(229)
63.6
(146.6)
21.28
10.0
(21,180)
6.60
(13,982)
51.9
(0.0227)
0.343
2.72
0.0050
(0.0119)
136
(0.0592)
0.894
(7.09)
0.0155
(0.0310)
Run No. R-2
11/11/83
96
116.3
227
(250)
66.8
(152.3)
30.63
10.36
(21,951)
5.97
(12,650)
52.5
(0.0229)
0.348
2.76
0.0055
(0.0110)
224
(0.0975)
1.40
(11.1)
0.0223
(0.0445)
Run No. R-3 Run No.
11/12/83
96
106.6
214
(236)
61.4
(142.5)
20.68
9.95
(21,076)
6.60
(13.973)
65.4
(0.0286)
0.431
3.42
0.0073
(0.0145)
365
(0.159)
2.40
(19.0)
0.0403
(0.0805)
Average
for test
series
•
—
—
--
216
(238)
63.9
(147.1)
24.20
10.10
(21,402)
6.39
(13,535)
56.6
(0.0247)
0.374
2.97
0.0063
(0.0125)
242
(0.105)
1.54
(12.4)
0.0260
(0.0520)
A-8
-------
TABLE A-5. ORGANIC EMISSION DATA AT PLANT A USING VARIOUS TEST METHODS
Inlet—uncontrolled
Run
no.
C-l
C-2
C-3
R-l
R-2
R-3
Original
TOC-la
mg/dscm
(gr/dscf)
470
(0.205)
996
(0.435)
681
(0.298)
1,030
(0.449)
1,500
(0.654)
1,160
(0.505)
Original
ECED
mg/dscm
(gr/dscf)
6.86
(0.003)
25.2
(0.011)
38.9
(0.017)
34.5
(0.019)
18.3
(0.008)
32.0
(0.014)
Reanalyzed
TOC-1C
mg/dscm
(gr/dscf)
2,190
(0.958)
1,560
(0.684)
1,380
(0.602)
1,570
(0.685)
2,660
(1.16)
2,200
(0.963)
Reanalyzed
TOC-2a
mg/dscm
(gr/dscf)
554
(0.242)
117
(0.0512)
129
(0.0562)
122
(0.0534)
120
(0.0523)
890
(0.389)
Original
TOC-13
mg/dscm
(gr/dscf)
121
(0.0531)
320
(0.139)
295
(0.129)
136
(0.0593)
223
(0.0974)
364
(0.159)
Outlet—controlled
Original
ECED
mg/dscm
(gr/dscf)
52.6
(0.023)
29.7
(0.013)
43.5
(0.019)
27.5
(o.oi2)
66.4
(0.029)
36.6
(0.016)
Reanalyzed
TOC-1C
mg/dscm
(gr/dscf)
431
(0.188)
353
(0.154)
533
(0.233)
664
(0.290)
364
(0.159)
434
(0.190)
Reanalyzed
TOC-2a
mg/dscm
(gr/dscf)
93.9
(0.0410)
115
(0.0502)
113
(0.0494)
147
(0.0644)
96.4
(0.0421)
42.4
(0.0185)
Original analysis by an unapproved method (TOC-1) resulting in inclusion of inorganic carbon in TOC
.values.
Analysis by ether/chloroform extraction method (extractable organics).
.Reanalysis by unapproved TOC-1 method after 9-month delay.
Reanalysis by approved Method 5E analysis method (TOC-2) after 9-month delay.
-------
TABLE A-6. SUMMARY OF VISIBLE EMISSIONS-PLANT A-
RAP MIX
Date
Run No.
Control device
Height of point of discharge, ft
Distance from observer to discharge point, ft
Direction of observer from discharge point
Description of background
Description of sky
Wind direction
Wind velocity, mph
Color of plume
Period of observation
Highest single reading, percent
Highest 6-minute average opacity, percent
11/10/83
Preliminary
Wet scrubber
30
300
South
Sky
Clear
North
20
White
1000-1620
5
2.7
1100
1200
Figure A-l. Six-minute averages of November 10, 1983.
Opacity readings on venturi scrubber stack during recycle operation.
A-10
-------
TABLE A-7. SUMMARY OF VISIBLE EMISSIONS—PLANT A—
CONVENTIONAL MIX
Date
Run No.
Control device
Height of point of discharge, ft
Distance from observer to discharge point, ft
Direction of observer from discharge point
Description of background
Description of sky
Wind direction
Wind velocity, mph
Color of plume
Period of observation
Highest single reading, percent
Highest 6-minute average opacity, percent
11/12/83
C-l
Wet scrubber
30
150
East
Sky
Blue; scattered clouds
Southeast
3-15
White
1130-1429
5
1.5
1200
Figure A-2. Six-minute averages of November 12, 1983.
Opacity readings on the venturi scrubber stack during
conventional operations.
A-11
-------
TABLE A-8. SUMMARY OF VISIBLE EMISSIONS—PLANT A-
RAP MIX
Date
Run No.
Control device
Height of point of discharge, ft
Distance from observer to discharge point, ft
Direction of observer from discharge point
Description of background
Description of sky
Wind direction
Wind velocity, mph
Color of plume
Period of observation
Highest single reading, percent
Highest 6-minute average opacity, percent
11/11/83
R-l
Wet scrubber
• 30
50-125
Northeast-
Southwest
Sky
Clear
0819-1136 North;
1308-1718 South
1-5
White
0837-1441
10
5.8
M'OO
ieoo
Figure A-3. Six-minute averages of November 11, 1983.
Opacity readings on venturi scrubber stack during recycle operation.
A-12
-------
TABLE A-9. SUMMARY OF UNCONTROLLED EMISSION TEST RESULTS—PLANT B~
RAP MIX PROCESS UNIT: DRUM PLANT MIX
Data
General
Date
Sampling time, min
Isold netic ratio, percent
Production rate, Mg/h
(tons/h)
Gas stream data
Temperature, °C
(°F)
Moisture, percent
Flow rate, mVs
(acfm)
Flow rate, dsmVs
(dscfm)
Participate emissions
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Total Organic Carbon--TOC
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Run No. R-l
5/8/84
32
99.7
188
(207)
141.6
(286.9)
30.31
18.05
(38,242)
8.93
(18,914)
18,500
(8.09)
165
(1,310)
3.165
(6.33)
799
(0.349)
7.11
(56.4)
0.136
(0.272)
Run No. R-2
5/10/84
32
101.2
172
(190)
150.9
(303.7)
28.95
17.31
(36,682)
8.56
(18.129)
12,700
(5.54)
109
(861)
2.265
(4.53)
117
(0.051)
0.999
(7.92)
0.021
(0.042)
Run No. R-3
5/10/84
32
97.5
174
(192)
143.7
(290.7)
30.4
17.23
(36,504)
8.49
(17.993)
14,100
(6.15)
120
(949)
2.47
(4.94)
124
(0.054)
1.06
(8.40)
0.022
(0.044)
Run No. R-4
5/10/84
32
101.5
186
(205)
145.2
(293.4)
32.2
16.30
(34,524)
7.80
(16,521)
12.100
(5.28)
94.3
(748)
1.825
(3.65)
119
(0.052)
0.918
(7.28)
0.19
(0.036)
Average
for test
series
--
--
--
178
(196)
145.4
(296)
30.5
17.22
(36.488)
8.44
(17,889)
13,000
(5.66)
108
(853)
2.185
(4.37)
120
(0.052)
0.992
(7.87)
0.021
(0.041)
A-13
-------
TABLE A-10. SUMMARY OF CONTROLLED EMISSION TEST RESULTS--PLANT B—
RAP MIX PROCESS UNIT: DRUM PLANT MIX
Data
General
Date
Sampling time, min
Isokinetic ratio, percent
Production rate, Mg/h
(tons/h)
Gas stream data
Temperature, °C
Moisture, percent
Flow rate, ms/s
(acfm)
Flow rate, dsnVs
(dscfm)
Particulate emissions
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Total Organic Carbon--TOC
mg/dscni
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Run No. R-l
5/8/84
119
82.6
190
(209)
70.5
(158.8)
29.51
13.65
(28,909)
8.30
(17,592)
263
(0.115)
2.00
(15.9)
0.038
(0.076)
52.6
(0.023)
0.438
(3.47)
0.008
(0.017)
Run No. R-2
5/10/84
72
102.1
172
(190)
67.7
(153.8)
24.8
12.86
(27,241)
8.42
(17,833)
298
(0.130)
2.51
(19.9)
0.0525
(0.105)
57.2
(0.025)
0.487
(3.86)
0.010
(0.020)
Run No. R-3
5/10/84
72
104.7
177
(195)
71.1
(160)
30.2
14.02
(29,073)
8.26
(17,503)
327
(0.143)
2.70
(21.4)
0.055
(0.110)
57.2
(0.025)
0.467
(3.70)
0.0095
(0.019)
Run No. R-4
5/10/84
72
102.3
185
(204)
71.5
(160.8)
30.4
13.15
(27,856)
7.88
(16,700)
259
(0.113)
2.03
(16.1)
0.0395
(0.079)
43.5
(0.019)
0.351
(2.78)
0.007
(0.014)
Average
for test,
series*
--
--
—
178
(196)
70.1
(158.2)
28.5
13.34
(28,057)
8.19
(17,345)
295
(0.129)
2.41
(19.1)
0.049
(0.098)
52.6
(0.023)
0.435
(3.45)
0.009
(0.018)
aAverage for the test series
isokinetic.
was based on R-2, R-3, and R-4 because R-l was less than 90 percent
A-14
-------
TABLE A-11.
SUMMARY OF VISIBLE EMISSIONS—PLANT B—
RAP MIX
Date
Run No.
Control device
Height of point of discharge, ft
Distance from observer to discharge point, ft
Direction of observer from discharge point
Description of background
Description of sky
Wind direction
Wind velocity, mph
Color of plume
Period of observation
Highest single reading, percent
Highest 6-minute average opacity, percent
5/8/84
R-l
Wet scrubber
30
175
Northeast
Sky
Clear
East
10-15
White
1425-1745
20
11.9
135-
IJ-
\
i«n
1900
isa
tan
too
two
trao
Figure A-4. Six-minute averages of the visible emissions from the
venturi scrubber stack during particulate/TOC Run 1 at the
Sloan Construction Company Asphalt Concrete Plant,
Cocoa, Florida, on May 8, 1984.
A-15
-------
TABLE A-12.
SUMMARY OF VISIBLE EMISSIONS-PLANT B--
RAP MIX
Date
Run No.
Control device
Height of point of discharge, ft
Distance from observer to discharge point, ft
Direction of observer from discharge point
Description of background
Description of sky
Wind direction
Wind velocity, mph
Color of plume
Period of observation
Highest single reading, percent
Highest 6-minute average opacity, percent
5/10/84
R-2
Wet scrubber
30
150
East
Sky
Clear—partly cloudy
Northwest
5-10
White
0800-1027
25
17.5
J
OBOO QUO QUO 000 1000
nut
Figure A-5. Six-minute averages of the visible emissions from the
venturi scrubber stack during particulate/TOC Run 2 of the
Sloan Construction Company Asphalt Concrete Plant,
Cocoa, Florida, on May 10, 1984.
A-16
-------
TABLE A-13.
SUMMARY OF VISIBLE EMISSIONS—PLANT B—
RAP MIX
Date
Run No.
Control device
Height of point of discharge, ft
Distance from observer to discharge point, ft
Direction of observer from discharge point
Description of background
Description of sky
Wind direction
Wind velocity, mph
Color of plume
Period of observation
Highest single reading, percent
Highest 6-minute average opacity, percent
5/10/84
R-3
Wet scrubber
• 30
150
East
Sky
Clear
Northwest
5-10
White
1139-1410
25
16.9
nil
1130 120B
1230 1300
TIME
1330 MOO
Figure A-6. Six-minute averages of the visible emission from the
venturi scrubber stack during particulate/TOC Run 3 at the
Sloan Construction Company Asphalt Concrete Plant,
Cocoa, Florida, on May 10, 1984.
A-17
-------
TABLE A-14.
SUMMARY OF VISIBLE EMISSIONS—PLANT B—
RAP MIX
Date
Run No.
Control device
Height of point of discharge, ft
Distance from observer to discharge point, ft
Direction of observer from discharge point
Description of background
Description of sky
Wind direction
Wind velocity, mph
Color of plume
Period of observation
Highest single reading, percent
Highest 6-minute average opacity, percent
5/10/84
R-4
Wet scrubber
30
150
West
Sky
Partly cloudy
North
5-10
White
1540-1659
20
12.9
11.5-
iaao
ion
tibo
Figure A-7. Six-minute averages of the visible emissions from the
venturi scrubber stack during particulate/TOC Run 4 at the
Sloan Construction Company Asphalt Concrete Plant,
Cocoa, Florida, on May 10, 1984.
A-18
-------
TABLE A-15. SUMMARY OF UNCONTROLLED EMISSION TEST RESULTS-PLANT C—
CONVENTIONAL MIX PROCESS UNIT: DRUM PLANT MIX
Data
General
Date
Sampling time, rain
Isokinetic ratio, percent
Production rate, Mg/h
(tons/h)
Gas stream data
Temperature, °C
(°F)
Moisture, percent
Flow rate, mj/s
(acfm)
Flow rate, dsm'/s
(dscfm)
Participate emissions
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Total Organic Carbon — TOC
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Run No. C-l
7/24/84
75
94.6
220
(242)
152.7
(307)
24.8
23.72
(50,259.5)
12.28
(26,008)
43,479.31
(19.006)
535.53
(4,250.32)
8.78
(17.56)
43.46
(0.019)
0.532
(4.22)
(0.0085)
(0.017)
Run No. C-2
7/25/84
75
101.3
217
(239)
202.2
(396)
27.1
26.32
(55.770.8)
11.84
(25,095)
34,433.89
(15.052)
407.95
(3,237.77)
6.78
(13.55)
475.83
(0.208)
5.64
(44.757)
(0.0935)
(0.187)
Run No. C-3 Run No.
7/25-26/84
75
106.4
206
(227)
173.3
(344)
31.4
22.45
(47,569)
10.14
(21,483)
38,215.40
(16.705)
387.567
(3,076.07)
6.78
(13.55)
375. 176
(0.164)
3.816
(30.290)
(0.0665)
(0.133)
Average
for test
series
--
--
—
214
(236)
176.1
(349)
27.8
24.17
(51,199.8)
11.42
(24,195)
38,709.53
(16.921)
443.68
(3,521.086)
7.46
(14.92)
298. 15
(0.130)
3.33
(26.422)
(0.056)
(0.112)
A-19
-------
TABLE A-16. SUMMARY OF CONTROLLED EMISSION TEST RESULTS-PLANT C--
CONVENTIONAL MIX PROCESS UNITS: DRUM PLANT MIX
Data
General
Date
Sampling time, rain
Isokinetic ratio, percent
Production rate, Mg/h
(tons/h)
Gas stream data
Temperature, °C
(°F)
Moisture, percent
Flow rate, raVs
(acfm)
Flow rate, dsmVs
(dscfm)
Par ficu late emissions
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Total Organic Carbon— TOC
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Run No. C-l
7/24/84
64
•
91.5
219.5
(242)
128.9
(264)
28.3
18.7
(39,642.7)
9.8
(20,823)
25. 164
(0.011)
0.237
(1.88)
0.0039
(0.0077)
947.09
(0.414)
9.314
(73.927)
0.153
(0.305)
Run No. C-2
7/25/84
60
94.0
216.8
(239)
140.5
(285)
25.6
22.1
(46.783.9)
11.7
(24,804)
297.396
(0.130)
3.492
(27.718)
0.058
(0.116)
75.49
(0.033)
0.890
(7.066)
0.0148
(0.0295)
Run No. C-3 Run No.
7/25-26/84
64
103.9
205.9
(227)
131.7
(269)
33.9
18.9
(40,007.8)
9.1
(19,261)
2,951.08
(1.29)
26.82
(212.88)
0.469
(0.938)
908.2
(0.397)
8.25
(65.477)
0.144
(0.288)
Average
for test
series
..
--
--
214.1
(236)
133.9
(273)
29.3
19.9
(42,144.8)
10.2
(21,620)
1,091.21
(0.477)
10.18
(80.82)
0.171
(0.342)
643.59
(0.281)
6.15
(48.825)
0.103
(0.206)
A-20
-------
TABLE A-17. SUMMARY OF UNCONTROLLED EMISSION TEST RESULTS—PLANT C—
RAP MIX PROCESS UNIT: DRUM PLANT MIX
Data
General
Date
Sampling time, nrin
I sold neti c ratio, percent
Production rate, Mg/h
(tons/h)
Gas stream data
Temperature, °C
(°F)
Moisture, percent
Flow rate, mVs
(acfm)
Flow rate, dsmVs
(dscfm)
Participate emissions
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Total Organic Carbon — TOC
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Run No. R-l
6/23/84
75
102.3
317
(349)
186.1
(367)
27.2
32.25
(68,315.9)
14.98
(31,733)
12,673.65
(5.54)
189.97
(1,507.76)
2.16
(4.32)
25.164
(0.011)
0.3805
(3.02)
0.0043
(0.0086)
Run No. R-2
6/25/84
75
102.6
320
(353)
140
(284)
35.1
30.92
(65,502.2)
14.12
(29,919)
16,020.50
(7.003)
226.27
(1,795.89)
2.544
(5.087)
146.41
(0.064)
2.065
(16.39)
0.0232
(0.0464)
Run No. R-3 Run No.
6/25/84
75
101.4
307
(338)
185.6
(366)
33.6
32.20
(68,220.7)
13.56
(28,727)
15,594.99
(6.817)
211.50
(1,678.59)
2.48
(4.96)
93.79
(0.0410)
1.345
(10.068)
0.0149
(0.0297)
Average
for test
series
—
--
--
314
(346)
170.6
(339)
31.9
31.79
(67,346.3)
14.22
(30,126.3)
14.763.05
(6.453)
209.25
(1,660.74)
2.39
(4.779)
88.45
(0.0386)
1.263
(9.83)
0.0142
(0.0284)
A-21
-------
TABLE A-18. SUMMARY OF CONTROLLED EMISSION TEST RESULTS—PLANT C--
RAP MIX PROCESS UNIT: DRUM PLANT MIX
Data
General
Date
Sampling time, min
Isokinetic ratio, percent
Production rate, Mg/h
(tons/h)
Gas stream data
Temperature, °C
(°F)
Moisture, percent
Flow rate, mVs
(acfm)
Flow rate, dsmVs
(dscfm)
Participate emissions
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Total Organic Carbon--TOC
mg/dscm
(gr/dscf)
9/s
(Ib/h)
kg/Mg
(Ib/ton)
Run No. R-l
6/23/84
96
93.6
317
(349)
136.1
(277)
29.8
26.10
(55,296.6)
13.21
(27,994)
41.17
(0.0180)
0.556
(4.417)
0.0063
(0.0126)
34.315
(0.015)
0.466
(3.702)
0.0053
(0.0106)
Run No. R-2
6/25/84
96
102.5
320
(353)
131.7
(269)
34.4
25.04
(53,055.2)
11.87
(25,158)
75.49
(0.033)
0.909
(7.215)
0.0102
(0.0204)
146.41
(0.064)
1.73
(13.743)
0. 0195
(0.0389)
Run No. R-3 Run No.
6/25/84
96
100.1
307
(338)
137.8
(280)
32.8
25.58
(54,195.6)
12.25
(25,962)
34.31
(0.015)
0.430
(3.410)
0.005
(0.0100)
173.86
(0.076)
2.123
(16.834)
0.0249
(0.0498)
Average
for test
series
•
—
--
314
(346)
135
(275)
32.3
25.57
(54,182.5)
12.45
(26,371.3)
50.32
(0.022)
0.632
(5.014)
0.0072
(0.0143)
118. 18
(0.052)
1.44
(11.426)
0.0165
(0.0330)
A-22
-------
TABLE A-19. SUMMARY OF VISIBLE EMISSIONS—PLANT C--
CONVENTIONAL MIX
Date 7/25/84
Run No. C-2
Control device Baghouse
Height of point of discharge, ft 40
Distance from observer to discharge point, ft 75
Direction of observer from discharge point East
Description of background Sky
Description of sky Scattered clouds
Wind direction Northeast
Wind velocity, mph 0-5
Color of plume White; gray-white
Period of observation 0904-1301
Highest single reading, percent 25
Highest 6-minute average opacity, percent 12
aData reading methods were inconsistent with Method 9 procedures.
A-23
-------
TABLE A-20.
SUMMARY OF VISIBLE EMISSIONS—PLANT C—
CONVENTIONAL MIX
Date
Run No.
Control device
Height of point of discharge, ft
Distance from observer to discharge point, ft
Direction of observer from discharge point
Description of background
Description of sky
Wind direction
Wind velocity, mph
Color of plume
Period of observation
Highest single reading, percent
Highest 6-minute average opacity, percent
7/25/84
C-2a
Baghouse
40
150
Southeast
Sky
Cloudy
East
0-10
White; gray
1212-1251
25
15
Readings intentionally taken 30 to 40 ft downwind from stack in an effort
to measure blue haze that did not form at'the stack.
A-24
-------
TABLE A-21. SUMMARY OF VISIBLE EMISSIONS—PLANT C--
CONVENTIONAL MIX
Date 7/25/84
Run No. C-3a
Control device Baghouse
Height of point of discharge, ft 40
Distance from observer to discharge point, ft 175
Direction of observer from discharge point South, west
Description of background Sky
Description of sky Blue
Wind direction South
Wind velocity, mph 0-25
Color of plume White
Period of observation 1505-1636
Highest single reading, percent 60
Highest 6-minute average opacity, percent 44
aData reading methods were inconsistent with Method 9 procedures.
A-25
-------
TABLE A-22. SUMMARY OF VISIBLE EMISSIONS—PLANT C--
CONVENTIONAL MIX
Date 7/26/84
Run No. C-3a'D
Control device Baghouse
Height of point of discharge, ft 40
Distance from observer to discharge point, ft 75
Direction of observer from discharge point East
Description of background Sky
Description of sky Cloudy
Wind direction West
Wind velocity, mph 0-15
Color of plume White
Period of observation 0820-0835
Highest single reading, percent 0
Highest 6-minute average opacity, percent 0
^Continuation of Run C-3 which began on 7-25-84 (see Table A-21).
Data reading methods are inconsistent with Method 9 procedures. Readings
taken at end of plume, approximately 50 feet from stack.
A-26
-------
TABLE A-23.
SUMMARY OF VISIBLE EMISSIONS—PLANT C—
CONVENTIONAL MIX
Date
Run No.
Control device
Height of point of discharge, ft
Distance from observer to discharge point, ft
Direction of observer from discharge point
Description of background
Description of sky
Wind direction
Wind velocity, mph
Color of plume
Period of observation
Highest single reading, percent
Highest 6-minute average opacity, percent
7/26/84
Particle size test
Baghouse
• 40
75
East
Sky
Cloudy
North
0-15
White
0949-1047
40
32
aData readings are inconsistent with Method 9 procedures. Readings taken at
end of plume, approximately 60 ft from stack.
I
o
3 20-
•
w
10
0100 0900 lOOO "00 I20O iJOO I4OO <5OO
» JULT IW«
O00O 090O GOO HOO <200
21 JW.Y i«84
Figure A-8. Six-minute average opacity during conventional operation.
A-27
-------
TABLE A-24. SUMMARY OF VISIBLE EMISSIONS—PLANT C—
RAP MIX
Date 6/23/84
Run No. R-la
Control device Baghouse
Height of point of discharge, ft 40
Distance from observer to discharge point, ft 200
Direction of observer from discharge point East
Description of background Sky
Description of sky Hazy
Wind direction North
Wind velocity, mph 10
Color of plume White
Period of observation 0915-1036
Highest single reading, percent 35
Highest 6-minute average opacity, percent 25
aData reading methods are inconsistent with Method 9 procedure. Readings
taken approximately 20 ft from stack.
A-28
-------
TABLE A-25. SUMMARY OF VISIBLE EMISSIONS—PLANT C-
RAP MIX
Date 6/25/84
Run No. R-2
Control device Baghouse
Height of point of discharge, ft 45
Distance from observer to discharge point, ft 100
Direction of observer from discharge point East
Description of background Sky
Description of sky Blue
Wind direction Northwest
Wind velocity, mph 10
Color of plume White; light gray
Period of observation 1055-1353
Highest single reading, percent 25
Highest 6-minute average opacity, percent 9
aData reading methods are inconsistent with Method 9 procedure. Readings
taken approximately 10 ft from stack.
A-29
-------
TABLE A-26. SUMMARY OF VISIBLE EMISSIONS—PLANT C--
RAP MIX
Date 6/25/84
Run No. R-3a
Control device Baghouse
Height of point of discharge, ft 40
Distance from observer to discharge point, ft 120
Direction of observer from discharge point Southwest
Description of background Sky
Description of sky Pale blue; hazy
Wind direction South
Wind velocity, mph 5-20
Color of plume White; gray
Period of observation 1523-1731
Highest single reading, percent 40
Highest 6-minute average opacity, percent 34
aData reading methods are inconsistent with Method 9 procedure. Readings
taken at 10 to 20 ft from stack.
A-30
-------
TABLE A-27. SUMMARY OF VISIBLE EMISSIONS—PLANT C~
RAP MIX
Date 6/25/84
Run No. R-3a
Control device Baghouse
Height of point of discharge, ft 40
Distance from observer to discharge point, ft 150
Direction of observer from discharge point West
Description of background Sky
Description of sky Blue, hazy
Wind direction South, southeast
Wind velocity, mph 10 to 15
Color of plume White
Period of observation 1655-1731
Highest single reading, percent 35
Highest 6-minute average opacity, percent 26
aReadings taken intentionally 15 ft downwind from stack in an effort to
measure blue haze which did not form at the stack.
Figure A-9. Six-minute average opacity during recycle operation.
A-31
-------
TABLE A-28. SUMMARY OF UNCONTROLLED EMISSION TEST RESULTS-PLANT D—
CONVENTIONAL MIX PROCESS UNITS: DRUM PLANT MIX
Data
General
Date
Sampling time, min
Isoklnetlc ratio, percent
Production rate, Mg/h
(tons/h)
Gas stream data
Temperature, °C
(°F)
Moisture, percent
Flow rate, mVs
(acfm)
Flow rate, dsmVs
(dscfm)
Particulate emissions
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Total Organic Carbon — TOC
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Run No. C-l
9/24/83
72
89.1
281
(310)
137
(279)
22.3
17.63
(37,351.6)
9.74
(20,638)
105,982.82
(46.328)
1,032.596
(8,195.388)
13.218
(26.436)
Run No. C-2
9/25/83
48
100.5
282
(311)
140
(284)
20.9
19.74
(41,819.8)
11.17
(23,662)
257,728.04
(112.660)
2,878.913
(22,849.019)
38.235
(76.47)
105.23
(0.046)
1. 1675
(9.266)
0.0149
(0.0298)
Run No. C-3
9/26/83
48
101. 9a
277
(305)
128
(263)
20.0
19.72
(41,774.2)
11.7
(24,798)
200,939.11
(87.836)
2,325.539
(18,457.072)
30.255
(60.51)
38.89
(0.017)
0.4672
(3.708)
0.0061
(0.0122)
Run No. C-4
9/27/83
48
99.8
244
(269)
133
(271)
18.6
18.80
(39,835.2)
11.15
(23,630)
122,389.94
(53.5)
1,365.289
(10,835.866)
20.14
(40.28)
96.08
(0.042)
1.076
(8.539)
0.01585
(0.0317)
Average
for test
series
'
--
--
271
(299)
135
(274)
20.45
18.97
(40,196.7)
10.9
(23,182)
171,759.98
(75,081)
1,900.58
(15,084.34)
25.225
(50.45)
80.06
(0.035)
0.903
(7.17)
0.0123
(0.0246)
Contaminated sample.
A-32
-------
TABLE A-29. SUMMARY OF CONTROLLED EMISSION TEST RESULTS—PLANT
CONVENTIONAL MIX PROCESS UNITS: DRUM PLANT MIX
D--
Data
General
Date
Sampling time, mln
Isokinetic ratio, percent
Production rate, Mg/h
(tons/h)
Gas stream data
Temperature, °C
(°F)
Moisture, percent
Flow rate, rnVs
(acfm)
Flow rate, dsm'/s
(dscfra)
Particulate emissions
mg/dscm
(gr/dscf)
9/s
(Ib/h)
kg/Mg
(Ib/ton)
Total Organic Carbon— TOC
mg/dscm
(gr/dscf)
9/s
(Ib/h)
kg/Mg
(Ib/ton)
Run No. C-l
9/24/84
126
98.7
281
(310)
124
(256)
19
23.36
(49.488.5)
13.97
(29,597)
18.301
(0.008)
0.2665
(2.115)
0.0035
(0.007)
41.18
(0.018)
0.585
(4.643)
0.0075
(0.015)
Run No. C-2
9/25/84
99
101.1
282
(311)
123
(253)
17.7
24.03
(50,904.1)
14.84
(31,448)
57.192
(0.025)
0.8643
(0.016)
0.011
(0.022)
41.18
(0.018)
0.622
(4.937)
0.00795
(0.0159)
Run No. C-3
9/26/84
126
101.2
277
(305)
120
(248)
18
23.86
(50,555.8)
14.84
(31.434)
64.054
(0.028)
0.9432
(7.498)
0.0125
(0.025)
36.60
(0.016)
0.5362
(4.256)
0.007
(0.014)
Run No. C-4
9/27/84
126
97.9
244
(269)
123
(253)
16.9
23.46
(49,709.6)
14.65
(31,032)
50. 328
(0.022)
0.72083
(5.721)
0.0105
(0.021)
36.60
(0.016)
0.524
(4.159)
0.0077
(0.0154)
Average
for test
series
«
--
--
271
(299)
123
(253)
17.9
23.68
(50,164.4)
14.57
(30.878)
47.469
(0.0207)
0.698
(5.545)
0.0095
(0.019)
38.89
(0.017)
0.567
(4.499)
0.0076
(0.0151)
A-33
-------
TABLE A-30. SUMMARY OF UNCONTROLLED EMISSION TEST RESULTS—PLANT D—
RAP MIX PROCESS UNIT: DRUM PLANT MIX
Data
General
Date
Sampling time, min
Isokinetic ratio, percent
Production rate, Mg/h
(tons/h)
Gas stream data
Temperature, °C
(°F)
Moisture, percent
Flow rate, rnVs
(acfm)
Flow rate, dsm3/s
(dscfra)
Particulate emissions
mg/dscn
(gr/dscf)
9/s
(Ib/h)
tcg/Mg
(Ib/ton)
Total Organic Carbon— TOC
mg/dscra
(gr/dscf)
9/s
(Ib/h)
kg/Mg
(Ib/ton)
Run No. R-l
9/28/84
48
103.5
301
(332)
171
(340)
20.5
206.31
(43,708.7)
109.95
(23,294)
16,208.08
(7.085)
178.238
(1,414.622)
2.13
(4.26)
64.05
0.028
0.7058
(5.602)
0.008
(0.0168)
Run No. R-2
9/28/84
48
104.6
281
(310)
174
(346)
21.1
199.84
(42.339.3)
104.99
(22,244)
25,013.3
(10.939)
262.78
(2,085.637)
3.364
(6.727)
164.7
0.105
2.525
(20.046)
0.0323
(0.0646)
Run No. R-3 Run No.
9/28/84
48
106.7
281
(310)
176
(349)
23.1
205.09
(43,451.2)
104.85
(22,215)
19,799.72
(8.655)
207.734
(1,648.073)
2.659
(5.318)
56.57
0.035
0.8502
(6.748)
0.0105
(0.021)
Average
for test
series
--
--
--
288
(317)
174
(345)
21.6
203.745
(43,166.4)
106.598
(22,584)
20,340.367
(8.89)
216.251
(1,716.330)
2.707
(5.414)
88.94
0.056
1.36
(10.798)
0.017
(0.034)
A-34
-------
TABLE A-31. SUMMARY OF CONTROLLED EMISSION TEST RESULTS—PLANT D~
RAP MIX PROCESS UNIT: DRUM PLANT MIX
Data
Run No. R-l Run No. R-2
Run No. Run No.
Average
for test
series
General
Date
Sampling time, min
Isokinetic ratio, percent
Production rate, Mg/h
(tons/h)
Gas stream data
Temperature, °C
(°F)
Moisture, percent
Flow rate, raVs
(acfra)
Flow rate, dsmVs
(dscfm)
Particulate emissions
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Mg
(Ib/ton)
Total Organic Carbon—TOC
mg/dscm
(gr/dscf)
g/s
(Ib/h)
kg/Kg
(Ib/ton)
9/28/83
126
106.8
301
(332)
9/28/83
126
105
281
(310)
105.1
(302.2)
21.1
18.301
(0.008)
0.2109
(1.674)
0.0025
(0.005)
137.26
(0.06)
1.625
(12.889)
0.0194
(0.0388)
157.2
(315)
21.7
21.14
(44,969.2)
11.79
(25,087)
23.79
(50,615.1)
12.96
(27,567)
13.726
(0.006)
0.1868
(1.483)
0.0024
(0.0048)
116.67
(0.51)
1.159
(12.059)
0.01945
(0.0389)
288
(317)
153.4
(308.6)
21.4
22.465
(47,792.15)
12.375
(26,327)
16.014
(0.007)
0.198
(1.578)
0.0025
(0.0049)
125.82
(0.055)
1.57
(12.479)
0.01965
(0.0393)
A-35
-------
TABLE A-32.
SUMMARY OF VISIBLE EMISSIONS—PLANT D--
CONVENTIONAL MIX
Date
Run No.
Control device
Height of point of discharge, ft
Distance from observer to discharge point, ft
Direction of observer from discharge point
Description of background
Description of sky
Wind direction
Wind velocity, mph
Color of plume
Period of observation
Highest single reading, percent
Highest 6-minute average opacity, percent
9/25/84
C-2
Baghouse
25
50
South
Sky
Blue
Northwest
15
White/gray
1300-1736
5
1.25
!?-
200 >300
<«00
i»00
TIME
'600
1700
1800
Figure A-10. Six-minute average opacity during conventional operation.
A-36
-------
TABLE A-33.
SUMMARY OF VISIBLE EMISSIONS— PLANT D~
RAP MIX
Date
Run No.
Control device
Height of point of discharge, ft
Distance from observer to discharge point, ft
Direction of observer from discharge point
Description of background
Description of sky
Wind direction
Wind velocity, mph
Color of plume
Period of observation
Highest single reading, percent
Highest 6-minute average opacity, percent
9/28/84
R-l
Baghouse
• 25
50
South
Sky
Blue
North northwest
10
White/gray
1032-1457
5
5.0
s-
I
3.
iQOO
—I—
iiOO
1200
1—
uoo
TIMt
I4OO
UOO
Figure A-11. Graphic representation of visual emission observations.
A-37
-------
APPENDIX B
SUMMARY OF STATE REGULATIONS FOR ASPHALT CONCRETE FACILITIES
A review of State regulations for asphalt concrete plants Indicates
that most States have adopted the same emission limits as required by
the present NSPS for this industry. Those States that presently have
standards more stringent than the current NSPS are listed in Table B-l.
Reference Method 5, established by the EPA, is used by all of these
States except Pennsylvania, which includes the soluble portions of the
back-half catch in its results.
B-l
-------
TABLE B-l. STATES WITH AIR EMISSION STANDARDS FOR ASPHALT CONCRETE
PLANTS STRICTER THAN THE NSPS OF 90 mg/dscm (0.04 gr/dscf)
State
Standard
mg/dscmgr/ascf
New Jersey1
New York*
45.8
68.8
Pennsylvania3 45.8
0.02
0.03
0.02
Utah4
O.C.5
Maryland6
45.8
80.3
68.8
68.8
0.02
0.035
0.03
0.03
If generate £50 Ib/h participate.
Ninety-nine percent collection
efficiency (or 0.5 Ib/h) if generate
<50 Ib/h particulate.
For plants that operate above
250,000 pounds per hour.
Unless the following formula yields
a more lenient standard:
A = 0.76 E°'42, where
E = FXW(F = 6 Ib/ton aggregate
feed)
W - tons/h (aggregate feed)
A = Ib/h
Plants producing virgin mix.
Plants producing recycle mix.
Zero percent opacity.
B-2
-------
REFERENCES FOR APPENDIX B
1. Telecon. M. Maul, MRI, with D. Blasi, and L. Mikolajczyk, New Jersey
Bureau of Air Pollution Control. January 17, 1984. State regulation.
2. Telecon. M. Maul, MRI, with D. Spencer, and B. Kerr, New York
Department of Environmental Conservation. January 17. 1984. State
regulation.
3. Telecon. M. Maul, MRI, with J. Benson, Pennsylvania Department of
Environmental Regulation. January 17, 1984. State regulation.
4. Telecon. M. Maul, MRI, with M. Keller, Utah Bureau of Air Quality.
January 30, 1984. State regulation.
5. Telecon. M. Maul, MRI, with D. Wambsgans, District of Columbia
Department of Environmental Services. January 20, 1984. District
regulation.
6. Telecon. B. Terry, MRI, with K. Gunkel, Maryland Air Management
Administration. January 17, 1984. State regulation.
B-3
-------
APPENDIX C
EMISSION MEASUREMENT METHODS
C.I INTRODUCTION
C.I.I Background
The EPA Office of Air Quality Planning and Standards conducted an
emission test program at four asphalt concrete producing facilities
between November 1983 and September 1984. Selection of the test sites
was based upon (1) processing of recycled asphalt pavement (RAP), (2) type
of operation and/or emissions control systems, (3) results obtained
during prior NSPS compliance testing, and (4) suitability for isokinetic
testing.
The test program consisted of sampling conventional and recycled
asphalt concrete process emissions at uncontrolled and controlled sources.
The emission control devices consisted of two baghouses and two scrubber
systems.
C.I.2 Objective
The purpose of the emission test program was to determine and
evaluate emission levels being generated from asphalt concrete plants
producing conventional and RAP mixes. The test program included
determining emission levels for the following parameters:
1. Particulate matter;
2. Total organic carbon/extractable organics;
3. Visible emissions;
4. Particle size;
5. Polynuclear aromatic hydrocarbons;
6. Scrubber and baghouse process samples; and
7. Trace metal emissions.
C-l
-------
The following narrative describes the rational for selection of the
methods used, the sampling procedures and equipment configurations, the
sample recovery procedures, and the analytical procedures used to obtain
the test data.
C.2 SELECTION OF SAMPLING AND ANALYTICAL METHODS
C.2.1 Preliminary Review
The EPA investigated several candidate sampling and analytical
procedures for measuring emissions from the asphalt concrete process.
The major pollutants of interest were particulate matter and condensible
hydrocarbons. The investigation consisted of reviewing test methods
that had previously been used to sample and analyze asphalt concrete
plant particulate emissions. Currently, EPA Method 5 is specified for
NSPS compliance testing. In addition, several procedures to determine
levels of condensible hydrocarbons and their relationship to blue haze
were evaluated.
The conclusion reached from the preliminary review for the
particulate emissions testing was that EPA Method 5 would be the best
method. The Method 5 procedure would allow the collected information
(front half catch) to be compared with the data collected previously
during NSPS compliance testing.
Three condensible hydrocarbon methods were selected for preliminary
screening. Method 25, which produces a total carbon number, was rejected
because of the overriding interferences of carbon dioxide and water in
the emission sources. Extractable organics as determined from the
ether/chloroform extract of the 0.1 N NaOH impinger solution and gravi-
metric analysis was the second condensible hydrocarbon method rejected
from consideration. The extracted organic method was eliminated because
of a loss of organic hydrocarbons that was encountered during analytical
operations. Reference Method 5E, which determines total organic carbon
(TOC) content by subtracting the total inorganic carbon from the total
carbon content, was selected. The use of this method provided the
following conveniences for the test program:
C-2
-------
1. The sample collection train could be combined with the Method 5
configuration, thereby allowing particulate and condensible hydrocarbon
results to be determined simultaneously;
2. The TOC number could be converted to a weight basis by using
the molecular weight of carbon, thus allowing the results to be added to
the particulate emissions, if desired;
3. The Method 5E (TOC) had been tried and proven in a standards
development testing program (wool fiberglass manufacturing);
4. Method 5E is simple and relatively easy to perform; and
5. Method 5E could be used to determine the uncontrolled and
controlled emission levels without any modification of detection limits
or sampling and analytical procedures.
Reference Method 9 protocol was selected for evaluating the visible
emissions. Because of the different control devices (baghouses and
scrubbers), the color of the plume (blue/gray haze), and the temperature-
dependent opacity, specific observation procedures had to be considered
for each test site.
Particle size determination test procedures were evaluated prior to
the emission test program. Because of the high moisture (30 percent),
excessive grain loading (75.0 grains/dscf), and temperature (350°F)
encountered at the inlet to the control devices, an Andersen High Capacity
Stack Sampler was selected to determine the uncontrolled particle size
distribution. This unit allowed a reasonable sampling time to be
performed at isokinetic sampling conditions. The controlled emission
sources required a different unit because of the fairly low grain loading
(0.03 grains/dscf) and the saturated gas stream associated with the
scrubber control devices. An Andersen Mark III with a precutter separator
and nine fraction sizes was selected for the controlled emission sources.
The precutter was specified to limit the quantity of large particles
being drawn into the impactor.
Polynuclear aromatic hydrocarbon (PAH) test procedures were evaluated
prior to the emission test program. Sampling, sample recovery, and
sample analysis protocols were selected from state-of-the-art established
procedures. Major organic species and benzo(a)pyrene were selected to
be analyzed by gas chromatography-mass spectrometry (GC-MS) for four
C-3
-------
field samples. The major organic species analyzed were selected based
upon relative peak heights of the GS-MS scan.
Sampling and/or monitoring of control devices and process operations
was conducted according to procedures established prior to the sampling
program. Analytical methods were selected for evaluating the individual
process samples and are described in the following:
Sample type Analysis Analytical method
Virgin aggregate Percent moisture Modified ASTM
RAP Percent moisture Modified ASTM
RAP Smoke point Oklahoma Test Lab
RAP Flash point Oklahoma Test Lab
Asphalt cement Smoke point ASTM D92
Asphalt cement Flash point ASTM D92
Scrubber water Dissolved solids ASTM
Scrubber water Suspended solids ASTM
Scrubber water TOC EPA Method 5E
Scrubber water pH Instrument
Scrubber water Temperature Instrument
Scrubber water Trace metals ICAPES
Scrubber water PAH GS-MS
Trace metal test procedures were evaluated prior to the emission
test program. Two analytical procedures were considered for the trace
metals; atomic absorption spectroscopy (AAS) and inductively-coupled
argon plasma emission spectroscopy (ICAPES). The ICAPES technique was
selected over the AAS procedure primarily because of lower cost and less
time required to analyze the large number of samples. Although the AAS
technique is more sensitive and has a lower detection limit, it requires
that each element be determined by a separate analysis. The ICAPES
system is computer-controlled, which allows for simultaneous multi-
element determinations. The AAS unit is believed to be more accurate;
however, the ICAPES system provides for an automatic background correction
to adjust for matrix interferences. Thirteen elements were selected for
trace metal investigation.
C.2.2 Preliminary Field Evaluation and Analysis
An actual preliminary field evaluation of the selected methods was
not conducted prior to the standard development program. However, a
number of sampling and analytical protocols were performed and compared
C-4
-------
during the NSPS field test program. The following describes these
different variations.
C.2.2.1 Sampling. The impinger train configuration and impinger
contents varied depending upon the emission specie(s) of interest.
Additional impingers were added during several runs to collect trace
metal samples. Extra impingers were inserted when high moisture levels
(35 percent) were experienced in the gas stream.
The fiberglass filter temperature was controlled automatically by a
time proportioning temperature controller using a thermocouple positioned
in the exit stream of the glass filter holder. The exit stream of the
filter was to be maintained at 250°F ± 10°F.
A stainless steel probe was used during several runs at the plant A
outlet location. High winds and stack vibrations had broken all of the
glass liner probes that the contractor had available.
C.2.2.2 Sample Recovery. No water rinse was performed on the
probe as is specified in the Method 5E procedures. It was not necessary
to separate water soluble particles from the remaining particulate
catch.
The acetone rinse of the probe was followed by a second organic
solvent rinse using trichloroethane at test site A. Particulate removal
efficiency of the acetone was being evaluated. The rinses' were stored
and analyzed separately.
A trichloroethane rinse that is not specified in Method 5E was
performed on the impingers following the 0.1 N NaOH rinse. A thin black
film adhered to the impinger walls and could be removed only with an
organic solvent.
C.2.2.3 Sample Analysis. Condensible hydrocarbons were analyzed
by two different methods for test site A to evaluate and compare the
results of the two analytical procedures. The TOC was determined by EPA
Method 5E, and extractable organics were determined by the ether/
chloroform extraction, evaporation, and drying procedures.
The Method 5E TOC samples were analyzed by two different techniques.
Samples from site A (inlet and outlet) were analyzed, first, by acidifying
the sample below a pH of 2 with H2S04 and purging with nitrogen to
remove the inorganic carbon. The second method was performed according
C-5
-------
to EPA Method 5E protocol (analyzing total inorganic carbon and total
carbon and determining organic carbon by difference). A series of
analyses using these two methods was performed during a 4-month period
(see Appendix B).
Impinger contents were recovered and analyzed separately for two of
the test sites. Each impinger was recovered and analyzed separately for
TOC content to determine the collection efficiency of the train
configuration.
The black film rinse recovered from the impingers was reduced by
drying and then weighed to determining the organic mass.
C.3 SAMPLING AND ANALYSIS TEST PROGRAM
C.3.1 Particulate Emissions Testing
Particulate emission tests were performed in accordance with EPA
Reference Method 5 (40 CFR Part 60-Appendix A) for the standards
development portion of the testing. Multiple point isokinetic sampling
was conducted at sampling points located according to EPA Methods 1 and
2 wherever the site permitted. Sampling was conducted in locations as
close as possible to the specified points.
Entrained water droplets were encountered at the two scrubber
outlet locations. Despite the water droplets and the proximity of some
sampling locations to flow disturbances, the test results are considered
to be representative of the source emissions. Testing was conducted on
uncontrolled and controlled process emissions during production of both
conventional and recycle mixes. Sample recovery and participate analytical
determinations were performed in accordance with criteria presented in
the reference method.
C.3.2 Visible Emissions Testing
Visible emission measurements of the control source effluent were
conducted in accordance with EPA Reference Method 9 (40 CFR Part 60-
Appendix A). Observations of visible emissions from a single controlled
source (scrubber, baghouse discharge) to the atmosphere were performed
concurrent with the emissions sampling when appropriate. Opacity readings
were recorded every 15 seconds and summarized in 6-minute averages.
Observations were performed during production of both conventional and
C-6
-------
recycle mixes except during interruption in production or testing or
when a contrasting background for the blue/gray plume was unavailable.
Each observer location was selected to provide both a clear view of the
effluent emissions without interference from the sun or overcast sky and
a line of vision approximately perpendicular to the plume direction with
a contrasting background.
The two scrubber visible steam plumes were attached to the stack;
consequently, readings were performed beyond the point in the plume
where the condensed water vapor was no longer visible. The effluent
emissions from the two baghouses were observed immediately above the
stack exit as condensed moisture did not interfere with the opacity
measurements at this point.
Visible emissions values obtained under these two different conditions
should not be compared because of the varying plume density, plume
diameter, potential emission condensation, and residual condensed moisture
interferences. When observations are performed after the disappearance
of the scrubber steam plume, the remaining plume normally is lightened
by dispersion. In contrast, the blue haze often observed with the
production of recycle mixes appears to darken as the emissions cool and
drift away from the stack. Because of these interferences, opacity
readings on the scrubber exhaust effluent are not good indicators of the
emission levels or the performance of the scrubber device.
The remaining tests that were conducted for secondary information
for the test program do not affect the standard development results and,
therefore, are not discussed in this document.
C.4 MONITORING SYSTEMS
C.4.1 Continuous Opacity Monitoring
Many new source performance standards for particulate emissions
require transmissometers (opacity monitors) to ensure proper operation
and maintenance of control devices. Transmissometer measurements are
not necessarily representative of opacity or mass emissions for the
effluent streams generated from asphalt concrete plants and, therefore,
are not recommended for this source. It is possible, for transmissometers
C-7
-------
to be operated on baghouse sources if the ambient temperature is above
the dew point of the stack gas.
The visible participate matter can vary with the stack gas
temperature, thus eliminating any correlation of the transmissometer
measurements with EPA Method 9 results. For example, at elevated stack
temperatures, condensible particulate emissions may exist in a vapor
state and would not be detected by the transmissometer. These emissions
would later recondense and be visible in the atmosphere.
Reference Method 9 is recommended on a daily basis for monitoring
the operation and maintenance of the process control devices. When
condensed moisture is present in the effluent stream such as from wet
scrubbers, Method 9 is not applicable, and another monitoring parameter
should be considered. Easily measured process parameters such as the
scrubber unit pressure drop and/or scrubber liquid flow rate should be
considered in lieu of continuous opacity monitors and Method 9 in these
cases.
C.4.2 Pressure Drop and Scrubber Liquid Flow Rate Continuous Monitoring
When scrubber systems are used for asphalt concrete plant emission
control, effluent gas pressure drop and scrubber liquid flow rate measuring
devices are recommended for monitoring the operation. Calibration and
maintenance intervals of the measuring unit should be established according
to manufacturer specifications.
The initial equipment and installation cost for installing a pressure
drop measurement device, a scrubber liquid flow rate meter, and associated
automatic monitoring equipment is estimated to be less than $3,000 per
site. Annual operating cost including maintenance and data filing would
be approximately $750/site.
C.5 PERFORMANCE TEST METHODS
C.5.1 Particulate Emissions
Consistent with prior testing and with the data base gathered
during the standards development test program, the recommended performance
test method for particulate matter is EPA Method 5 (40 CFR Part 60-
Appendix A).
C-8
-------
Sampling cost for a performance test consisting of these Method 5
runs is estimated to be between $6,000 and $9,000. If plant personnel
are used to conduct the test, the cost would be less.
C.5.2 Visible Emissions
Reference Method 9 (40 CFR Part 60-Appendix A) is the performance
test method recommended for measurement of opacity for the asphalt
concrete plant exhaust sources. Method 9 is recommended for all sources
except exhaust sources where condensible particulate and/or hydrocarbon
matter may be combined with moisture or water droplets to cause an
interference with opacity determination.
C-9
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA 450/3-85-024
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Second Review of New Source Performance Standards for
Asphalt Concrete Plants
5 REPORT DATE
Drtnhpy 1QR5
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
13. TYPE OF REPORT AND PERIOD COVERED
DAA for Air Quality Planning and Standards
Office of Air and Radiation
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
14. SPONSORING AGENCY CODE
EPA 200/04
IS. SUPPLEMENTARY NOTES
16. ABSTRACT
This report reviews the current New Source Performance Standards for Asphalt
Concrete Plants. It includes a summary of the current standards, the status of
current applicable control technology, and the ability of plants to meet the
current standards.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Air Pollution
Asphalt Concrete Plants
Hot Mix Asphalt Facilities
Particulate Matter
Standards of Performance
Pollution Control
Air Pollution
13B
18. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Report I
Unclassified
21 NO. OF PAGES
1/17
20 SECURITY CLASS (Tinspage)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
------- |