;"{ „ . United States Office of Air EPA 340/1-79-110
July 1979
- ""K , .... .' ' n . United States Office of Air
il l(\V*~~-^ V^O^'Y Environmental Protection Washington DC 20460
\ I If Agency
vc/EPA Executive Summary
Implications of Ract
for the Cutback
Asphalt Industry
July 1979
-------
EPA 340/1-79-110
EXECUTIVE SUMMARY
IMPLICATION OF RACT FOR THE
CUTBACK ASPHALT INDUSTRY
by
Robert W. Elfstrom, Jr.
and
James A. Commins, P.E.
JACA Corp.
550 Pinetown Rd.
Fort Washington, EA 19034
Contract No. 68-01-4135
Tasks 40-41
Prepared for
U.S. Environmental Protection Agency
Division of Stationary Source Enforcement
Washington, DC 20460
Task Manager: Robert L. King
July, 1979
-------
ABSTRACT
This report has been prepared with the objective of
summarizing enforcement implications of adopting reasonably
available control technology (RACT) by the cutback asphalt
industry, as developed by the U.S. Environmental Protection
Agency (EPA), to control the emissions of volatile organic
compounds (VOC's) generated from cutback asphalt use in highway
construction. RACT prohibits the use of cutback asphalt
whenever substitution of emulsified asphalt is possible.
However, certain operational conditions and technical problems
of storage and application limit the extent of this substitu-
tion and the subsequent reduction in VOC emissions. Some state
highway departments use cutback asphalt in maintenance prac-
tices, but it is predominantly used on roads under local
jurisdiction in miscellaneous surface and cold asphalt mix (as
opposed to hot asphalt mix) applications. Consequently,
enforcement strategies may be needed down to the local level.
The EPA solicits comments from the reader regarding
any positive or negative experiences with emulsions as well
as any additional information that the reader feels is perti-
nent to this discussion. Comments may be sent to:
Robert L. King, DSSE (EN-341)
Environmental Protection Agency
401 M Street, S.W.
Washington, DC 20460
11
-------
This report was submitted in partial fulfillment of
Contract No. 68-01-4135, Tasks 40-41 by JACA Corp., under the
sponsorship of the U.S. Environmental Protection Agency. The
contents of this report are reproduced herein as received from
the contractor. The opinions, findings, and conclusions
expressed are those of the authors and not necessarily those of
the Environmental Protection Agency.
iii
-------
ACKNOWLEDGEMENT
The technical discussions and data supplied to JACA from
many sources are gratefully appreciated. The authors wish to
express sincere appreciation to John DiRenzo, Vice President
of Highway Materials, Inc., Fred Kloiber, Director of Engineer-
ing and Operations for the National Asphalt Pavement Associa-
tion, Larry Ostermeyer, Vice President of Technical Services
and Mike Guerin, Field Engineer, McConnaughay, Inc. who crit-
ically reviewed this report. We would also like to note the
assistance of The Pennsylvania Department of Transportation,
The Pennsylvania Asphalt Pavement Association, The Asphalt
Institute, and The Asphalt Emulsion Manufacturer's Association.
iv
-------
Table of Contents
Page
INTRODUCTION *
Process Description 2
Volatile Organic Compound (VOC) Emissions 10
TECHNICAL FACTORS AND IMPLICATIONS 13
VOC Emissions 13
Storage, Handling, and Application of
Emulsified Asphalt 15
Enforcement 19
-------
List of Tables and Figures
Table No- Page
1 1977 CUTBACK ASPHALT VOC EMISSIONS H
2 STATE ROAD MILEAGE AND % UNDER LOCAL
JURISDICTION 20
Figure No.
1 SCHEMATIC OF AN ASPHALT PAVEMENT 3
2 1977 NATIONAL VOC EMISSION FROM
CUTBACK ASPHALT USE 22
VI
-------
INTRODUCTION
This document addresses the control of volatile organic
compounds (VOC's) generated from the use of cutback asphalt
in road construction and maintenance. Cutback asphalt is
asphalt cement (basically a solid or semi-solid) which has been
diluted with petroleum solvents (VOC's) to control set up time
of the pavement mixture. Cutbacks are occasionally mixed with
aggregates in asphalt mix plants to produce maintenances mixes
for pothole repair and other types of emergency uses. The bulk
of cutbacks are used in cold asphalt mixes and in miscellaneous
surface applications applied at the construction site.
The Environmental Protection Agency (EPA) has published
a Control Techniques Guideline (CTG) for cutback asphalt users
specifying reasonably available control technology (RACT).
RACT prohibits the use of cutback asphalt whenever substitution
of emulsified asphalt is possible. Because an emulsified
asphalt is basically a suspension of asphalt cement in water
and an emulsifying agent, such a substitution has the potential
to reduce VOC emissions significantly.
Operational conditions and technical problems of
storage and application limit the extent to which the substitu-
tion can be achieved. It is helpful to evaluate the potential
impact of RACT in terms of VOC reductions in the context of
these limitations.
-1-
-------
This document provides the reader with necessary
background information on the materials and equipment required
to construct and maintain an asphalt pavement and specifies
those areas where cutback and emulsified asphalts are used. In
addition, it presents technical factors of implementing RACT
which involve VOC emissions, storage, handling, and application
of emulsified asphalt, and enforcement.
Process Description
The process of constructing a road, which has been
described below, requires the laying of several hot or cold
mixed paving courses. Although the Control Techniques Guide-
line (CTG) is only applicable to cold mix operations, a
description of hot mix processes has been included to enhance
the reader's understanding of the paving industry.
An asphalt pavement is a compacted mixture of asphalt
cement, coarse aggregate and fine aggregate which have been
sized to design specifications. It may consist of several
layers or courses. The number of courses and the design
specifications depend on a number of factors such as the
subsoil structure, the average daily traffic (ADT), the type
of vehicles expected in the traffic mix, and the predicted
vehicle speeds. An example of this structure is shown in
Figure 1.
-2-
-------
FIGURE 1
SCHEMATIC OF AN ASPHALT PAVEMENT
TACK COAT
PRIME COAT
The subgrade (or soil) is leveled and stabilized if
necessary. Sub-base material consisting of one or more
layers of aggregate is evenly distributed over its surface.
A prime coat, a highly penetrating low viscosity liquid bitumi-
nous material, may be sprayed on the sub-grade or sub-base,
although the latter is more common. The prime coat penetrates
into the course forming a water resistant layer on its surface,
hardens and stabilizes the surface, and helps bind it to the
following asphalt course. The base, wearing course, and seal
coat sequentially cover the sub-base with aggregate size
progressively decreasing. The base, often referred to as black
base, serves as the foundation course and is constructed in 3
to 4 inch lifts of aggregate and an asphaltic binder. The
-3-
-------
wearing course is a single or multiple surface treatment of
asphalt and aggregate, whereas the seal coat is an optional
final cover applied to waterproof the asphalt surface and
improve its texture.
The duration of time between spreading and rolling the
base, wearing course, and seal coat may be long enough to
require the use of a tack coat. The tack coat, like the prime
coat, is also a low viscosity spray-applied preparation coat
which serves as an adhesive layer for the succeeding cover
material.
At asphalt mixing plants, the asphalt cement is either
mixed with aggregate which has been heated to a range of
temperatures nominally between 270° and 330°F (called a hot
asphalt mix) or with aggregate which has been heated to a
range of temperatures nominally between 100° and 150°F
(called a cold asphalt mix). Cold asphalt mixes may also be
prepared at the job site by mixing the asphalt cement with
aggregate at ambient temperature. Hot mixing requires melting
of the asphalt cement to liquify it while cold mixes are
prepared with liquid cutback or emulsified asphalt. The choice
of whether to use a hot or cold mix depends on the type of road
construction or surface treatment required, prevailing weather
conditions and job site location. A hot mix asphalt layer is
the highest quality surface.
Hot asphalt mixes are conventionally produced in
batch or continuous plants where the various sized aggregate
-------
is combined, dried and heated, separated as to size, recom-
bined, and then mixed with asphalt cement. Almost 85% of new
plants, however, use a technique known as drum mixing, which
combines drying, heating and mixing operations. This elimi-
nates the need for hot elevators, screens, and bins of the
conventional plants, but requires sophisticated cold feed
blending systems and surge or storage bins to store the drum-
mixed product.
Conventional operations in the hot mix process are:
1. Cold aggregate (which includes coarse aggregate up
to 2-1/2 inches in diameter and fine aggregate consisting of
a natural sand and/or finely crushed stone, slag, gravel
or synthetic aggregate such as expanded shale or clay) is
proportioned on the basis of size according to the design
specifications and transported by a common conveyor and/or
bucket elevator to the inlet of the dryer. Mineral filler
consisting of very finely crushed stone, hydrated lime, fly
ash, Portland cement, and other non-plastic mineral filler
may also be mixed with the cold aggregate (proportioned on
the basis of weight).
2. The rotating dryer has a series of internal flights
which cause the aggregate to form a curtain across the cross-
section of the drum. Aggregate temperature is raised to a
range of temperatures nominally between 270° and 330°F in
order to remove surface moisture and to improve the subsequent
asphalt coating. The capacity of the dryer is dependent on
-5-
-------
cold aggregate characteristics. As the percentage of fines and
moisture increase/ fuel consumption increases and aggregate
cold feed rates decrease.
3. The aggregate is discharged at the end of the
dryer into a bucket elevator which transports the material
to a set of vibrating screens which separate the aggregate
by size and drop it into appropriate hot storage bins.
Aggregate from these bins is weighed in the weigh hopper
according to mix specifications and job mix formulas and
discharged into the pugmill.
4. The pugmill mixes the dry aggregate for a few
seconds and then a spraybar, an "asphalt bucket", or other
metering device adds asphalt cement (approximately 5% by
weight). After 20 to 40 seconds of further mixing the product
is discharged into waiting trucks or surge or storage bins.
Hot mix plant operators occasionally reduce the temper-
ature on the aggregate dryer to between 100° to 150° F and
run cutback or emulsified asphalt through the pugmill to
produce what is known as a cold mix. (Cutback and emulsified
asphalts will be described in more detail later.) Cutback
asphalts are used with a nominal aggregate temperature of
110°F while some emulsified asphalts are used at slightly
higher temperatures. The temperature of the aggregate in the
dryer is lowered when cutbacks are used to prevent the vola—
tiles in the asphalt mixture from escaping and to reduce tha
chance of fire and explosion in the pugmill.
-6-
-------
Cold mixes are commonly mixed at the construction site
by traveling pugmills or mixed on the surface being treated
(in-situ) by motor graders. There are two types of traveling
pugmills. One mechanically gathers a prepared aggregate
windrow, adds and mixes cutback or emulsified asphalt with
the aggregate as it progresses, and then discharges onto the
roadbed a mixed windrow for aeration, spreading, and compact-
ing. The second type of traveling pugmill contains a hopper
which accepts aggregate from a haul truck, adds and mixes the
cutback or emulsified asphalt with the aggregate, and spreads
the mix on the roadbed.
In-place mixing is performed with a motor grader
which, after scarifying the bed, moves along the road surface,
grinds it with a series of tines and adds the emulsified
asphalt (which may require extra water) or cutback asphalt,
leaving the combined mix in the same basic position but in an
uncompacted state. To simplify mixing, this procedure may be
modified by attaching a mixing blade to the scarification unit
to produce windrows. The motor grader would then move longitu-
dinally over each windrow and perform the mixing.
Some states have central maintenance facilities (low
volume central mixing plants) which are responsible for
small-scale repairs and maintenance of state and county
roads. At these facilities pugmills are often replaced by
mixing platforms where the aggregate and cutback or emulsi-
fied asphalt are blade-mixed and front-end loaded into stock-
piles for storage or into trucks for immediate use at ambient
-7-
-------
temperature.
The time for the hot or cold mixed asphalt product to
harden is a key factor in product handling since it influences
workability and subsequent product quality. It is referred
to as curing time. Hot asphalt mixes set-up strictly by
cooling down to ambient temperature. In hot asphalt mixes,
the laying temperature of the mix must be within 15°F of
the plant's mixing temperature (based on refinery recommenda-
tions). The hot mix may also be transported on heated trucks
or, as in Pennsylvania, be stored in uninsulated surge or
storage bins for a maximum of 3 to 4 hours, stored in partially
heated and insulated storage silos for a maximum of 24 hours,
or stored in completely heated and insultated silos (possibly
sealed with inert gas) for longer than 24 hours depending on
product characteristics. Storage equipment and times may vary
in each state. In cold asphalt mixes which are stored and
applied at ambient temperatures and in prime and tack coat
applications where a low viscosity asphalt is required, it is
necessary to treat the asphalt cement in some way. The asphalt
cement may be diluted with a volatile organic solvent producing
a cutback asphalt or blended with a surfactant and water
producing an asphalt emulsion. Generally, cutbacks cure by the
evaporation of solvents whereas emulsions cure by the evapora-
tion of water which is freed when the asphalt particles coal-
esce.
There are three types of cutback asphalts. They include
-8-
-------
rapid curing cutbacks (RC) where highly volatile gasoline or
naptha is the solvent; medium curing cutbacks (MC) where the
less volatile kerosene is the solvent; and slow curing asphalt
(SC) where a low to non-volatile oil is the solvent. Average
evaporation percentages for RC, MC and SC cutback have been
estimated to be 80, 70 and 25 percent, respectively. Solvent
concentrations in cutbacks may be as high as 50% by volume;
however, a reasonable average is 20%. This figure is based
on the approximate average of solvent concentrations in four
grades of cutback most commonly used in cold mix operations
including RC 250, RC 800, MC 250 and MC 800. At this average,
the percent of solvent by weight for SC, MC and RC cutback
asphalt is 17.8, 17.0, and 14.6, respectively.
Emulsified asphalt, on the other hand, is processed
by running molten asphalt cement and treated water through a
colloid mill which imparts enough shear stress to produce
very small asphalt particles. A surface active ingredient
(surfactant) in the mixture provides a wetting action and
results in the asphalt particles assuming a charged state.
Consequently, emulsified asphalts are classified by this
charge and the time for the emulsion to coalesce - separate
into asphalt and water constituents. The terms rapid set
(RS), medium set (MS) and slow set (SS) are used to designate
set-up time. The terms cationic, anionic and nonionic desig-
nate the charge of the asphalt as positive, negative, or
neutral, respectively.
-9-
-------
According to state emulsified asphalt specifications,
volatile organic solvents are ingredients in some asphalt
emulsions. The specified maximum oil distillate ranges from
0 to 20%. Average evaporation percentages, for the solvents
used in these emulsions have not been determined.
Volatile Organic Compound (VOC) Emissions
The asphalt paving industry has been cited as a signifi-
cant VOC source of emissions because of its extensive use of
cutback asphalt. The amount of VOC's emitted into the air
from cutback asphalt use is, in part, determined by the
volatility and quantity of the solvent used in "cutting-back"
the asphalt cement. Other variables are the length of time
the cutback asphalt is exposed to the atmosphere during
storage, handling, and road surface applications, as well as
any methods employed by the plant to control emissions (i.e.,
impermeable tarps over the long-term storage piles and haul
trucks); the temperature; and the relative humidity.
In 1975 cutback asphalt paving and sealing operations
across the nation generated nearly 4% of the VOC's emitted
from stationary sources, and in some east central states it
accounted for about 15% of each state's VOC total. 1977
regional VOC emissions resulting from cutback asphalt use
are shown in Table 1. That year, approximately 30% of the
nation's VOC emissions were emitted from one region, 50%
-10-
-------
Table I
1977 CUTBACK ASPHALT VOC EMISSIONS
State
EPA Region JL
Connecticut
Maine
Massachusetts
New Hampshire
Rhode Island
Vermont
Total
Region II
New Jersey
New York
Total
Region III
Delaware
feryland (DC)
Pennsylvania
Virginia
West Virginia
Total
Region IV
Alabama
Florida
Georgia
Kentucky
Mississippi
North Carolina
South Carolina
Tennessee
Total
Hcg^on V
Illinois
Indiana
Michigan
Minnesota
Ohio
Wisconsin
Total
(1,000
VOC Emissions
1.3
1.8
1.9
2.5
Z.I
776
3.9
9.8
13.7
.1
3.8
18.6
8.3
1.3
32.1
4.8
5.7
4.0
2.9
.4
4.4
1.9
1.8
25.9
38.6
13.7
7.7
12.6
34.9
15.8
123.3
tons)
State
EPA Region VI
Arkansas
Louisiana
New Mexico
Oklahoma
Texas
Ibtal
EPA Region VII
Iowa
*£msas
Missouri
Nebraska
Total
EPA Region VIII
Colorado
Montana
forth Dakota
South Dakota
Utah
Wyoming
Ibtal
EPA Region IX
Arizona
California
Rawa i i
Nevada
Total
EPA Region X
Alaska
Idaho
Oregon
Washington
'fbtal
National Total
-11-
VOC Emissions
8.0
2.4
5.2
19.5
10.7-
4 5 . 81
9.1
11.0
22.0
5.1
47.2
5.4
5.7
5.8
4.8
4.2
5.0
30. .9
6. 0
25.3
.3
2.4
34.0
1.0
5.2
2. 0
9.5
17.7
378.2
-------
from three regions and 75% from six regions.
As previously stated, the Environmental Protection
Agency (EPA) has published a Control Techniques Guideline
(CTG) for the cutback asphalt industry specifying reasonably
available control technology (RACT). Because an emulsified
asphalt (which is water-based) contains significantly less
VOC' s than a cutback asphalt (which is solvent-based), RACT
prohibits the industry from using cutback asphalt whenever
substitution of emulsified asphalt is possible.
The implementation of RACT will reduce VOC emissions
because the amount of solvent used in the emulsified asphalt
is less than that used in cutback asphalt; also, solvent
evaporation may be less although this has not been quantita-
tively determined. Furthermore, energy can be conserved.
In 1975, for example, approximately 10 million barrels of
petroleum solvents were used in cutback asphalt. If the
crude oil used in making this amount of solvent had been
used to produce gasoline, about 4-1/2 million gallons of
gasoline could have been produced. This total energy savings,
however, must be reduced somewhat due to the energy expended in
hauling more weight of emulsions than cutback for a given
bitumen content. (See page 18 for bitumen content explana-
tion) .
-12-
-------
TECHNICAL FACTORS AND IMPLICATIONS OF RACT
VOC Emissions
In order to evaluate the effectiveness of RACT in
terms of a reduction in VOC emissions, it is necessary to
compare emissions generated from cutback and emulsified
asphalt use. Emulsions may contain varying amounts of volatile
organic solvents, so whenever a cutback is replaced by an
emulsified asphalt, this must be accounted for in estimating
VOC emission reductions. Use data such as the quantity and
grade designation of the cutback and emulsified asphalt used,
type of surface treatment, meteorological conditions, and any
deviation from normal operations which would effect VOC emis-
sions should be included in the analysis. Also, a maximum
concentration of solvent in emulsions should be set to avoid
the predicament when the emulsion is, in essence, an emulsi-
fied-cutback asphalt.
Based on state cutback asphalt sales data (supplied
by the U.S. Department of Energy), it is possible to arrive
at an estimate for VOC emissions generated from cutback
asphalt use. As an example, suppose 100 tons of SC, 450
tons of MC, and 326 tons of RC cutback asphalt were sold in
a state. Using the appropriate multipliers (see page 9),
state VOC emissions would be calculated in the following
manner:
-13-
-------
SC = (100) (.178) (.25) = 4.4 tons
MC = (450) (.170) (.70) = 53.5 tons
RC = (326) (.146) (.80) = 38.0 tons
Total = 95.9 tons
These calculations only reflect those VOC emissions
particular to cutback asphalt and do not take in to account
any of the necessary use data (referred to on page 13).
As RACT is implemented, data on national sales figures
of cutback asphalt and asphalt emulsions will serve as a check
of emission reductions. While getting these data on a state
level basis is easy, it would be preferable to have use data
from individual hot and cold mix asphalt companies and mis-
cellaneous surface applicators. Since it will be impossible to
do this on a national basis, a stratified random sample tech-
nique should be used. This method would involve dividing the
population (i.e., the 50 states) into strata or subsets based
on certain criteria (i.e., climatological factors such as
temperature, relative humidity, and precipitation). From each
stratum equal amounts of subsamples (i.e., asphalt companies
and surface applicators) would randomly be selected for data
collection.
Once area data is collected, net VOC emissions for
that area during a prescribed time can be estimated.
Emission rate factors specific to each type of surface
treatment (i.e., Ibs. VOC's emitted/hr) when applied to the
-14-
-------
reported quantities used and adjusted for the prevailing
temperature and humidity at the time of the operation (i.e.,
via a nomograph) should yield reasonable VOC emission esti-
mates. Presently, there are no such emission rate factors or
nomographs, which suggests the need for future research in this
area.
and Application of Emulsified Asphalt
It is imperative that the emulsion manufacturer be
intimately involved in the selection of the emulsion as well as
provide technical assistance in storing, handling, and applying
the emulsion. Of primary concern is matching the emulsion with
the job aggregate; however, one major issue remains unresolved.
Technical representatives from agencies such as the
Asphalt Institute, the Federal Highway Administration (FHWA) ,
the Asphalt Emulsion Manufacturer's Association (AEMA) and some
state highway departments believe that the key to matching the
aggregate with the emulsion depends on their respective elec-
trical charges. They feel that if an emulsion of one charge is
mixed with aggregate of the same charge, the asphalt may not
adequately coat the aggregate, resulting in a very poor seal
coat or mix. In contrast to this opinion, McConnaughay, Inc.
and several of their customers, including the Indiana State
Highway Commission, explain that the coating effectiveness of
the emulsion on the aggregate is based on emulsion formulation
-15-
-------
and not ionic classification. A discrepancy in opinions as
stated indicates that emulsion technology needs to be further
developed and properly transferred to those who use the ma-
terial.
The selection of the emulsion for the job aggregate is
based on prescribed tests provided by the asphalt emulsion
manufacturer. The emulsion manufacturer should also provide
some type of certification which states that their emulsion is
compatible with the aggregate. Additionally, premature coal-
escence of the emulsion can occur in feed lines, storage tanks,
and tank trucks if differently charged emulsions are mixed,
rendering the emulsion useless and requiring costly clean up
of the equipment. Therefore, it is necessary to employ proper
handling and storage procedures when using asphalt emulsions.
The Asphalt Institute, FHWA, and AEMA assisted by state highway
departments and many industrial technical representatives will
be conducting a new round of educational programs in the use of
asphalt emulsions in the Fall of 1979.
Even with these precautions it has been customary to
avoid application of emulsified asphalt under the following
conditions:
• When the temperature of the road surface or
ambient air approaches a level which impairs
the workability of the mix or the subsequent
product quality - a cut-off temperature (50°F)
-16-
-------
has been cited in draft SIPs and state DOT
specifications;
• When long-term stockpile storage is required
(i.e., cold patch reserves); and
• When a prime coat is to be applied.
The first two conditions involve either application
temperature or storage time. The third condition stems from
the actual size of the asphalt particle in the emulsion. In
an emulsion, asphalt cement particles are suspended in water
and a surfactant. If these particles are too large, penetration
into the surface voids may be inadequate which will weaken the
effect of the coat.
These limitations on the use of asphalt emulsions
reduce the substitution potential of asphalt emulsion for
cutbacks by about 25% and perhaps more in some of the colder
states. However, ongoing development of emulsion technology
may overcome some of these limitations in the future.
For example, several hot and cold mix operators in
Pennsylvania and Delaware have been successfully mixing,
storing for extended periods of time, and applying emulsified
asphalt cold patch material in cold weather. The highway
departments in Alabama, Indiana, South Carolina, and Tennessee*
have also succeeded in using it in prime coating. An effort 153
underway to find out what special techniques or feedstocks
these operators employ and to evaluate their extension to other
areas of the country.
-17-
-------
In constructing an asphalt pavement, residual bitumen
content (including the asphaltenes and maltenes) is another
technical factor. According to the American Society for
Testing and Materials (ASTM) specifications, the permissible
minimum residual bitumen content in the most commonly used
grades of cutback asphalt (referred to on page 9) is 65%.
However, for some grade of asphalt emulsions residual bitumen
content as low as 55% is permitted. As indicated by authori-
ties from the National Asphalt Pavement Association (NAPA), the
Pennsylvania Asphalt Pavement Association (PAPA), AEMA,
state highway and transportation departments, and several
asphalt plant operators, this difference in residual bitumen
content may entail the use of more emulsion than cutback when
laying certain road surface treatments. In essence there may
not be a one for one volumetric substitu tion. This affects
the potential VOC reductions and has economic and energy
implications.
In some operations approximately 3% (by weight) addi-
tional water is required from field service when using emulsi-
fied asphalt. This could be a limiting factor in arid regions.
Finally, there is a potential for adverse environmental side
effects which have not yet been examined. The amino compounds
present in some surfactants used in emulsions can leach out or
run off from inadequately cured road surfaces, especially
during heavy precipitation, resulting in poor road quality and
possible nitrogen contamination of ground and surface waters.
-18-
-------
Thus, upon further research into these side effects, topogra-
phic features in conjunction with weather conditions may
present more application limitations.
Enforcement
When an enforcement agency undertakes to implement
RACT guidelines it must deal with certain practical situa-
tions. The substitution must be agreeable to state DOTs and
preferably be incorporated in highway construction specifica-
tions. Enforcement would be comparatively easy in those
instances where state specifications require emulsified
asphalt, and the state has direct ability to enforce these
requirements on all levels of highway construction. Many
state DOTs are now specifying the use of emulsions rather
than cutback except for winter storage and prime coats.
The major problem is the limitation of state control in
local areas where most cutback asphalt is used (i.e., parking
lots, local and city streets, farm-to-market roads, and misc-
ellaneous surface applications). In Table 2, state road mileage
in each EPA region and the percentage under local jurisdiction
are shown. As an example, the New York State's highway depart-
ment in 1977 (see Table 2) practically eliminated the use of
cutback asphalt, but state VOC emissions from the use of
cutback asphalt (including SC, MC, and RC types) were estimated
to be 10,000 tons (see Table 1). This large remaining value
-19-
-------
r
TABLE II
STATE ROAD MILEAGE AND % UNDER
LOCAL JURISDICTION
State
EPA Region 1
Connecticut
Maine
Massachusetts
New Hampshire
Rhode Island
Vermont
Ibtal
Region II
New Jersey
Kaw York
Total
Region III
Delaware
Maryland (DC)
Pennsylvania
Virginia
West Virginia
Total
Region IV
Alabama
Florida
Georgia
Kentucky
Mississippi
North Carolina
South Carolina
Tennessee
Total
Region V
Illinois
Indiana
Michigan
Minnesota
Ohio
Wi scons in
Total
Total
Mileage*
18.9
21.5
31.3
15.2
5.5
13.8
106.2
32.7
108.9
141.6
5.2
28.6
114.9
62.4
36.5
247.6
86.4
98.1
100.6
69.9
67.0
88.6
60.6
81.1
652.3
131.1
91.4
118.6
128.1
110.3
104.7
684.2
%
Local
79
44
88
70
76
78
73
91
83
83
12
80
57
12
8
40
74
83
81
63
83
13
37
86
66
87
87
90
89
82
88
87
State
EPA Region VI
Arkansas
Louisiana
New Mexico
Oklahoma
Texas
Total
EPA Region VII
Iowa
Kansas
Missouri
Nebraska
•total
EPA Region. VIII
Colorado
Montana
North Dakota
South Dakota
Utah
Wyoming
Total
EPA Region IX
Arizona
California
Hawaii
Nevada
Total
EPA Region X
Alaska
Idaho
Oregon
Washington
Total
National Total
Total
Mileage^
78.2
53.5
70.2
108.4
253.7
564.0
112.8
134 . 7
67.0
97.8
412.3
84.3
78.2
105.9
82.6
48.4
31.9
431.3
52.1
169.6
3.7
49.7
•Z757I"-
9.8
56.5
103.3
81. 5
251.4
3766.0
jfc
Local
77
71
72
88
12
76
91
92
83
89
89
88
79
92
87
52
71
"82
54
69
70
£Q
64
23
50
40
61
48
74
*Units in 1000 miles (ARTBA, Highway Statistics, November, 1975)
-20-
-------
(even after state adoption of asphalt emulsion) may be due to
the fact that nearly 83% of the road mileage is under local
control.
In developing an enforcement strategy a decision must
be made as to what level of jurisdiction (i.e., regional,
state, or local) legal attention and related effort is neces-
sary to minimize VOC emissions by substituting emulsified
asphalt for cutback asphalt. In Figure 2 1977 national VOC
emissions from cutback asphalt use have been sectored according
to EPA regions. With the exception of Region I and II, which
contribute approximately 6% of. the emissions, those regions
which are significant contributors also have a large amount of
mileage under local control (see Table 2). Although too many
elements enter into the picture to compare road jurisdiction to
VOC emissions on a rigorous statistical basis, it can be
surmised from the information contained in Figure 2 that an
enforcement strategy is needed down to the local level.
An overall enforcement strategy would involve the
monitoring of state cutback and emulsified asphalt sales. This
can be readily accomplished since these data are already being
collected. In those instances where a state DOT has strong
indirect influence on local construction practices, enforcement
is also relatively simple. As an example, the Pennsylvania DOT
(PennDOT) indirectly affects the behavior of county and local
officials by placing construction restrictions on funds re-
ceived from gasoline tax sharing. The $.09 per gallon state
-21-
-------
FIGURE 2
1977 NATIONAL VOC EMISSIONS FROM CUTBACK ASPHALT USE
-22-
-------
gasoline tax provides for $.015 to be returned to county and
local governments if construction is carried out in accordance
with PennDOT specifications. In those states where such
indirect control through construction specifications and
funding are not in force, random sample enforcement is indica-
ted to be the only tangible, and feasible alternative.
Because there are production and application differences
with asphalt emulsions, technical exchanges between government
construction officials and producers and applicators will
improve acceptance of the substitution. Regional technology
transfer seminars or workshops could educate personnel from
state and local highway and transportation departments and
from industry in the proper ways to convert to, store, mix
and apply emulsified asphalt and associated asphalt mixtures.
These seminars would vary in intensity from state to state.
For example, Pennsylvania, Indiana, Virginia, and New York
have accepted emulsified asphalts and each has several years
experience, so training needs may be relatively light. On
the other hand, Illinois, Missouri, and Wisconsin which
have had bad encounters with emulsified asphalts, may need
more attention.
The foregoing discussion of highway jurisdiction
implications on the cutback-to-emulsion switch suggests that
several different enforcement strategies may need to be
developed for local areas. The problem is compounded by the
difficulty in isolating the relative impact of cutback VOC
-23-
-------
emissions for each local area considered on the basis of
attainment or non-attainment. A possible solution to minimize
the enforcement difficulties is to require the switch (with
consistent exceptions based on technical inabiity) everywhere
irrespective of the VOC attainment status.
-24-
-------
( BIBLIOGRAPHIC DATA
{SHEET
A T;ri..
1. Report No.
EPA 340/1-79-110
4. Titlv and Subtitle
Executive Summary: Enforcement Implication of RACT
for the Cutback Asphalt Industry
. Authar(s)Robert W.Elfstrom, Jr.
JACA Corp. James A. Commins, P.E.
. Performing Organization Name end Address
JACA Corporation
550 Pinetown Road
Fort Washington> PA 19034
2. Sponsoring Organization Name and Address
Division of Stationary Source Enforcement
U.S. Environmental Protection Agency
Washington, DC 20460
15. Supplementary Notes
3. Recipient's Accession No.
5. Kcpo/c Date
fc. Performing Organization Rci.;.
No. '
10. Projcci/Tasli/U'ojk Unh No.
11. Contract/Grant No,
68-01-4135 Task 40-41
13. Type of Ucj»ou & Period
Covered
App Ijed Keseare!; 1978-79
1-5.
16. Abstracts
,
been PrePared W1'th the objective of summarizing enforcement
^
17. Key Cords and Documcr' Analysis. I7a. Descriptors
Cutback Asphalt Users
Surface Treatment
Surface Applicators
Hot Mix Processes
Cold Mix Processes
Cutback Asphalt
Emulsified Asphalt
Volatile Organic Compounds
Emission Estimates
17b. Weiitifiers/Open-Ended Terms
Technical Factors of RACT
Enforcement Strategy of RACT
>7c. COSATI Field/Group
18. Availability Statement
ENDORSED BY ANSI AND UNESCO.
19. Security Chiss (1 Jiis
lU;,r,,0
20. Sccucity Class ( t his
21. No. ot Pages
23
22. Price
THIS FO11M MAY «£ RKPKODUCKD UICOMVI.DC »Jos.>-7*
------- |