EPA-450/3-77-021d
June 1977
A
W
AN IMPLEMENTATION PLAN
FOR SUSPENDED
PARTICIPATE MATTER
IN THE PHOENIX AREA
VOLUME IV - CONTROL
STRATEGY FORMULATION
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
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EPA-450/3-77-021d
AN IMPLEMENTATION PLAN
FOR SUSPENDED PARTICULATE MATTER
IN THE PHOENIX AREA
VOLUME IV - CONTROL STRATEGY
FORMULATION
by
George Richard
Environmental Engineering Division of TRW, Inc.
One Space Park
Redondo Beach, California
Contract No. 68-01-3152
EPA Project Officer: Dallas Safriet
Prepared for
ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
June 1977
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This report is issued by the Environmental Protection Agency to report technical
data of interest to a limited number of readers. Copies are available free
of charge to Federal employees, current contractors and grantees, and nonprofit
organizations - in limited quantities - from the Library Services Office (MD-
35), Research Triangle Park, North Carolina 27711; or, for a fee, from the
National Technical Information Service, 5285 Port Royal Road, Springfield,
Virginia 22161.
This report was furnished to the Environmental Protection Agency by Environmental
Engineering Division of TRW, Inc. , One Space Park, Redondo Beach, California,
in fulfillment of Contract No. 68-01-3152. Prior to final preparation, the report
underwent extensive review and editing by the Environmental Protection Agency.
The contents reflect current Agency thinking and are subject to clarification
and procedural changes.
The mention of trade names or commercial products does not constitute endorse-
ment or recommendation for use by the Environmental Protection Agency.
Publication No. EPA-450/3-77-021d
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TABLE OF CONTENTS
Page
1.0 INTRODUCTION AND SUMMARY 1-1
1.1 RESULTS 1-1
1.2 CONCLUSIONS AND RECOMMENDATIONS . . 1-0
2.0 CHARACTERIZATION OF ALTERNATIVE CONTROLS 2-1
2.1 CONTROL OF DUST EMISSION FROM UNPAVED ROADS 2-3
2.2 CONTROL OF ENTRAINED DUST OFF PAVED STREETS 2-13
2.3 CONTROL OF DUST FROM CONSTRUCTION ACTIVITIES 2-31
3.0 FORMULATION OF REASONABLE CONTROL STRATEGY 3-1
3.1 FACTORS AFFECTING SELECTION OF REASONABLE CONTROL
MEASURES 3-1
3.2 SELECTION OF REASONABLE STRATEGY 3-6
3.3 IMPACT OF STRATEGY ON EMISSION LEVELS 3-13
3.3.1 Unpaved Roads 3-18
3.3.2 Entrainment of Dust Off Paved Roads 3-21
3.3.3 Construction Activities 3-26
3.4 IMPACT ON AIR QUALITY 3-26
3.5 COST OF CONTROLS 3-36
3.6 IMPLEMENTATION PROBLEMS 3-38
3.7 DEMONSTRATION MODEL 3-42
in
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1.0 INTRODUCTION AND SUMMARY
This report is the fourth of four documents associated with a project
to develop an air pollution control strategy for total suspended particulate
matter in the Phoenix area. The previous documents include a review and
analysis of air quality data (Volume I), documentation of a particulate
emissions inventory (Volume II), and development of the relationship be-
tween emissions levels and air quality. The present report (Volume IV)
characterizes alternative control measures and documents the synthesis of
these candidate measures into a control strategy. The data base and
methodology developed in the project have been extended to provide a general
guideline document for application to areas with fugitive dust problems
similar to those in the Phoenix area.
A principal goal of the project was to develop a control strategy based
on "reasonable and achievable controls" that would minimize TSP concentra-
tions in the study area to the extent practicable. Such a plan has been
formulated and is described in this report. The strategy deals solely
with fugitive dust sources, the main cause of high TSP levels in Phoenix
today. Complete attainment of the standard is predicted with application of
reasonable and available controls.
The present section of this report introduces the study and summarizes
the major results and conclusions. Section 2 characterizes various candi-
date dust control methods for major fugitive dust sources causing high
levels of TSP in the Phoenix area. Section 3 discusses the factors in-
volved in reasonable control selection, and formulates a control strategy
based on these selection considerations. The impact of the control
strategy on emissions levels and air quality is evaluated, and the cost
and implementation problems associated with each of the control measures'
are documented.
1.1 RESULTS
A review of the emissions inventory developed earlier in the study^ '
showed that local fugitive dust sources are the most substantial contrib-
utor to TSP levels in the Phoenix area. By 1985, after planned develop-
ment changes the distribution and magnitude of the various sources, it is fore-
casted that three fugitive dust source categories will alone contribute to
1-1
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over 90% of the TSP levels in the study area. These sources are unpaved
roads, street dust on paved roads, and construction activities. Because
of the domination of TSP levels by these sources, the investigation of
alternative controls deals exclusively with their treatment.
Control methods to reduce dust emissions from unpaved roads consist
of: 1) paving, 2) chemical stabilizers, 3) watering, 4) graveling, and
5) traffic related controls. Characterization of these controls shows
that as a long term cost effective measure, paving of roads is the most
suitable control approach, as well as a relatively effective one. In
addition, road paving is compatible with planning objectives of local
agencies, and provides numerous cost benefits to many sectors of the
community. The effectiveness of chemical stabilizers as a road dust con-
trol has improved in recent years, but the high annualized cost of this
measure for only partial reduction of road emissions is a major drawback to
its use» The same shortcomings afflict watering and graveling controls.
Traffic controls such as speed restrictions are effective as interim con-
trol approaches, reducing dust emission rates significantly at very low
cost, but causing substantial inconvenience in areas where unpaved roads
serve as major travel routes.
Dust entrained from paved streets may be best controlled by either
eliminating sources of street dust, or by more frequent and efficient
removal of street dust loadings. Dust sources, consisting primarily of
exposed soil areas near the streets, are substantially reduced when unpaved
road shoulders are upgraded with curb and sidewalks. Further elimination
of sources is attained by providing soil cover (e.g. vegetation or aggregate
materials) or stabilization of adjacent soil areas. These measures are
relatively cost effective, and consistent with general improvement plans
in any community. Frequent street sweeping is an equally cost effective
measure, provided the suspendabl.e fines are removed by a suitable
cleaning approach such as vacuum sweeping.
Control methods to reduce dust arising from construction activities
consist of: 1) watering unpaved areas subject to traffic, 2) stabilization
of cleared areas of exposed earth, and 3) sweeping nearby public streets.
Enforcement of these measures, particularly wetting of unpaved access routes,
1-2
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provides significant reduction in dust emissions, and reduces the tempo-
rarily localized effects of construction activities on air quality.
In establishing the reasonableness (technological and economic
feasibility) of control measures, several area-specific factors must be
considered. These factors include: 1) the compatibility of the controls
with general planning of the area, 2) the timetable for implementation,
3) the degree of control required, and 4) the financing mechanisms available
for implementation of the control. Based on the characterization of
available control methods and a consideration of the above selection factors,
most of the measures for control of fugitive dust appear to be both
technically and economically feasible (reasonable) in the Phoenix area.
Control selection, therefore, reduces to a determination of the most cost
effective and least disruptive measures which will provide attainment
of air quality standards.
Table 1-1 summarizes the reasonable control strategy proposed for the
Phoenix area. The strategy has been formulated by evaluating successive
trials of specific combinations of cost effective measures until attainment
of air quality standards was predicted at each of the monitor sites. The
strategy was designed to minimize "overkill" at any given monitor site, and
to provide special attention where needed for attainment in "hot spot"
areas. The strategy is aimed at attainment over a reasonably achievable
time frame, beginning in 1978 and reaching complete attainment at all monitor
sites by 1975. Cost of the strategy is estimated at $4.4 million per year.
The measures comprising the strategy are consistent with long term
planning goals for the Phoenix region, and are also effective as dust
controls. The strategy is implementable in a technical and economic sense,
however, substantial social resistance'may likely develop against its
execution. A special feature of the overall strategy is a demonstration
model to develop social acceptance for; the strategy approach. This portion
of the strategy is discussed in Section 3.7. Another special proposal
concerns the extension of the current monitor network to establish base-
line air quality in specific locations identified by the study as potential
non-attainment areas after strategy implementation.
The reasonable control strategy formulated for the Phoenix area is
selective for the three major sources affecting TSP levels. The control
1-3
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TABLE 1-1.
SUMMARY OF REASONABLE CONTROL STRATEGY FOR PHOENIX AREA
NOTE: THE DEMONSTRATION STRATEGY IS PREREQUISITE TO
IMPLEMENTATION OF THIS PROGRAMb
SOURCE CATEGORY
CONTROL MEASURE
EMISSIONS REDUCTION FROM
1985 BASELINE LEVEL
tons/day percent
ANNUAL I ZED COST OF MEASURE
(Millions of Dollars)
Entrained Dust
Off Streets
Construction
Unpaved Roads 1. Chip Seal all section line roads
by 1995, and one half by 1985.
2. Reduced speed limit to 20 mph
for all interior unpaved roads
(private and county) by 1985
1. By 1985, sweep major city roads to attain
a 60% reduction in assumed street dust
loading in designated areas.b
1. Effective 1980, wetting of site access
roads twice daily at .5 gal/yd2.
2. By 1980, sweep roads to remove visible
dust loads caused by construction
activities. Sweeping shall be daily
if necessary.
3. By 1980, stabilization of exposed earth at
construction sites when operations cease
on this land for more than 2 months.
Other Sources No additional measures are recommended as
other sources are already controlled (either
by direct pollution regulations or by other
restrictions which affect dust control) or
have insignificant impact on TSP levels.
298
256
18
77
19.2%
16.5%
5.6%
5.0%
2.5
0.2
.36a
0.7
0.6
aBased on the required sweeping program indicated by the existing data base. This would consist of cleaning
major roads three times weekly, alternating from vacuum sweeping to broom sweeping as appropriate.
bThree field programs are proposed as prerequisites to implementation of the control strategy. First, a
demonstration project would involve application of the strategy measures within a limited selected area, and
promotional aspects to shape public acceptance for the eventual overall strategy. Second, a field measurement
program to determine street dust loads and effects of various sweeping alternatives should be conducted to
reconcile current sweeping controls indicated necessary by the limited existing data base. Third, the air
quality monitor network should be extended to establish baseline TSP levels at potential non-attainment areas
which may require additional controls in 1985.
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measures for unpaved roads exert the greatest impact on overall emission
levels. These controls reduce total baseline particulate emissions in the
study area by 35% in 1985. Figure 1-1 shows the impact of the control
strategy on emission levels. Overall, the total change in emission levels
ini1985, due to the strategy and to anticipated development in the study
area, amounts to a 31.6% reduction from the 1975 level. Emission reductions
attained by the year 1980 are less dramatic as only roughly two sevenths
of the strategy will be implemented by then.
Equally important as the emission level magnitudes are the distribu-
tion of the reductions. Emissions are reduced substantially in the areas
near the monitor sites. Because the major portion of ambient TSP levels
are caused by local sources in the near vicinity of the receptor, the impact
of the control strategy in areas near the monitors is substantial. Air
quality improvements at monitor sites in the specially designated control
area are dominated primarily by reductions in entrained street dust. How-
ever, sites outside the metropolitan influence or bordering the city tend
to be more affected by control measures proposed for unpaved roads.
Figure 1-2 shows the effect of the strategy on air quality at several of
the monitoring sites. By 1980, significant improvements in air quality are
predicted at many of the sites. However, these gains are minor compared
to the effect of the strategy by 1985, when baseline TSP levels are reduced
by about one third at most sites, and all' but two sites are forecasted
to attain (or very nearly attain) the primary air quality standards by 1985.
Air quality at the two exception sites was found to be unrepresentative
of the general area; hence, more stringent controls in the vicinity of these
monitors may be needed. However, before extensive site-specific plans are
implemented, more detailed analysis of the sites in question with regard to
monitor location, etc., should be completed. Additional air quality monitor-
ing data may also be necessary in order to further assess the problem and
evaluate the impact of the proposed strategy once it is implemented. TSP
levels at the Sun City and Glendale sites are substantially lower than the
standards level, but this is due to a low baseline concentration of TSP and
unavoidable impact of the strategy throughout the remainder of the area,
rather than an overkill control plan at these sites.
1-5
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o
^
CO
co
z
o
co
co
-------
CENTRAL PHOENIX
NORTH PHOENIX
CO
D.
co
209-'
TOO
o-
Baseline
Frlmary standard S --~-._~
Crnnt-Y-nl Qt-i-a
Strategy
200
co
75
80
SOUTH PHOENIX
85
200
100
Baseline
Control Strategy
Background
75
80
85
o>
: 100
0--
Baseline
Control Strategy
Background
75 80 85
N. SCOTTSDALE/PARADISE VALLEY
co
.E
O)
CO
200
100
Baseline
Primary Standard -
Control Strategy-
75
80
85
Figure 1-2. Impact of Dust Control Strategy on Suspended Particulate Levels at Monitor Sites in
Phoenix Area.
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I
00
CHANDLER
GLENDALE
200
co
. 100
Q.
Baseline
Primary Standard
Background
Control Strategy
co
200
100
o -
Baseline
Background
Control Strategy
75
80
MESA
85
75
Q.
IS)
200
100
o --
Baseline
Primary Standard
Background
Control Strategy
75
200
100
o -
80
ST. JOHNS
85
-Baseline
Primary Standard
-Control Strategy
Background
0
Figure 1-2. (Continued) Impact of Dust Control Strategy on Suspended Partlculate
levels At Monitor Sites in Phoenix Area
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SUN CITY
200
^6
en
. 100
Q.
o-
Baseline
Primary Standard
Background
--o-
"Control Strategy
TT
-85-
SCOTTDALE
200
CD
ft
-Baseline
Primary Standard --~^_
Background
Control Strategy
I
<£>
ARIZONA STATE
o>
200-
100
Baseline
Control
Primary Standard
Background
75
80
85
E
CD
CL.
CO
DOWNTOWN PHOENIX
200- '
100
Baseline
Control Strategy
Primary Standard
Background
75 80
Figure 1-2 (Continued). Impact of Dust Control Strategy on Suspended Particulate Levels at
Monitor Site in Phoenix Area
85
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1.2 CONCLUSIONS AND RECOMMENDATIONS
A reasonable control strategy can attain substantial improvements
in ambient air quality in Phoenix. Measures which are technically
and economically feasible can achieve the emission reductions re-
quired for attainment of the primary air quality standards for TSP.
The cost of clean air in Phoenix appears economical. Compared to
cities experiencing TSP non-attainment due to conventional emission
sources (e.g. Los Angeles), the cost effectiveness of lowering TSP
from fugitive dust in Phoenix is an order of magnitude less.
Successful implementation of the control strategy may be jeopardized
by social resistance (about 70% of the strategy costs must be
financed by public funds). A demonstration strategy should be
instituted to promote social acceptability for the strategy concept.
A local demonstration strategy is particularly appropriate for areas
experiencing widespread fugitive dust problems because of the
dominant local influence of these sources. A substantial portion
of the particle sizes from thse sources are greater than 15 microns,
and are limited in travel distance. However, because of their
widespread distribution throughout the Phoenix area, these sources
play a major role in measured.TSP levels at many sites. The
feasibility of improving air quality by eliminating such local
sources could be readily demonstrated by institution of a modest
local control program which is closely monitored.
The uncertainties involved in the analysis of dust pollution sources
makes justification of extensive control strategies untenable.
More precise demonstration is needed to warrant implementation of
the costly measures which are predicted to improve air quality.
The short term local model strategy is an appropriate vehicle for
this demonstration.
A special feature of the fugitive dust measures comprising the
strategy is their compatibility with overall planning objectives
for the area. Dust control for unpaved roads and paved city streets
are merely intensified extensions of current local programs (e.g.
paving of roads).
t The consistency between the major elements of the proposed control
strategy and planning objectives of local governmental agencies
permits a workable approach to implementation of dust controls.
The measures may be instituted and conducted as on-line operations
of the various local agencies, as opposed to the more conventional
procedure employing regulatory actions.
Because of uncertainties in the data base available for assessing
street dust loadings and street equipment sweeping efficiencies,
it is not possible to specify a definite street sweeping program
to accomplish the targeted emission reductions. A field measure-
ment program should be instituted to establish baseline loadings
1-10
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for various streets and to determine by test the actual sweeping
programs needed to obtain the allowable dust levels.
This study has identified nine potential non-attainment areas
(Figure 3-10) which may require additional control attention
in 19850 It is recommended that monitor sites be installed at
the indicated locations to establish baseline TSP levels for use
in air quality simulation and prediction of future TSP levels
there. The timetable for completing the expanded monitor network
should be immediate to permit appropriate adjustment of the proposed
control strategy (if necessary) before required deadlines.
0 To insure maximum effectiveness of the demonstration strategy as
a persuasive tool, implementation should include a public relations
program to promote awareness of the economic and air quality
benefits inherent in dust control plans. Opinion surveys should
be conducted to develop an understanding of the value forces which
must be shaped.
1-11
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2.0 CHARACTERIZATION OF ALTERNATIVE CONTROLS
In the Phoenix area, formidable reductions in fugitive dust emissions
must be achieved if air quality is to be upgraded to the National Ambient
Air Standards for suspended particulates. Therefore, the success of the
air pollution control plan will depend greatly on the effectiveness of
controls proposed for the major fugitive dust sources. Examination of the
1975 and 1985 emission inventories reveals the dominance of 5 major source
categories in the total emissions tabulation. Table 2-1 shows a listing
of the major particulate emissions expected from these sources in 1985.
Five sources are responsible for all but 17% of the particulate emissions
in 1975, and by 1985 these sources are estimated to account for all but
7% of the total particulate emissions in the study area. During the air
quality modeling task of this study [17], it was shown that three of the
major sources are almost entirely responsible for the high levels of sus-
pended particulates monitored throughout the study area. These sources
are fugitive dust arising from unpaved roads, dust off paved streets, and
construction activities.
The dominance of fugitive dust emissions in the particulate emissions
inventory (Table 2-1) is confirmed by microscopic analyses of the Hi-Vol
filters. Approximately 70% of all mass deposited on the filters consists of
particles greater than 20 micron diameters. ~[35] In areas where conventional
sources are already controlled (such as Phoenix), particles greater than
10 micron diameter are generally of fugitive origin. In the Phoenix study
area, one third of the fugitive dust emissions are estimated to be greater
than 20 micron diameter. The local impact of large particles is substantial.
Gravitational settling of the larger particles confines them to short
range transport, and limits their dispersion significantly. Controls which
treat these sources on a local basis may imorove local air quality substantially.
However, because the sources are widespread throughout the study area, the
effective control of these local sources must be area-wide to reduce the
local impact of particle deposition at many separate locations.
This chapter provides a general characterization of alternative control
methods which are applicable for prevention of fugitive dust emissions from
the three major source categories.
2-1
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TABLE 2-1. PARTICULATE EMISSIONS FROM MAJOR SOURCES* IN THE PHOENIX STUDY
AREA, 1975 AND 1985.
EMISSIONS , TONS/DAY
EMISSIONS SOURCE CATEGORY
1 . Unpaved Roads
2. Resuspension off paved roads
3. Construction activities
4. Wind Erosion-undisturbed
Desert
5. Off road vehicles
6. All other categories
Sub-total for 5 categories
Total emissions
.Percentage of all emissions
generated by 5 fugitive dust
categories
0-10y
537
164
66
200
29
258
996
1254
79.4
10-20y
144
57
23
65
8
70
297
367
81 :0
1975
20-lOOu
600
27
11
29
23
49
690
739
93.5
TOTAL
1281
248
100
294
71
386
1974
2360
83.7
0-lOy
637
213
169
58
44
105
1121
1226
91.5
1985
10-20y
171
74
59
19
12
16
335
351
95.5
.20-100y
745
35
28
8
50
19
866
885
98.0
TOTAL
1553
322
256
85
106
140
2322
2462
94.3
PO
I
ro
* The five sources listed above are the largest emitting sources of particulates projected to exist in 1985.
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2.1 CONTROL OF DUST EMISSIONS FROM UNPAVED ROADS
Control methods to reduce dust emissions from unpaved roads consist
of (1) paving roads, (2) application of chemical stabilizers, (3) watering,
and (4) traffic related controls. Both the city of Phoenix and Maricopa
County have considered these alternatives as candidate measures in their
respective improvement program.
In 1960, the City Transportation Department rejected use of measures
which are temporary or of short term nature and adopted an overall plan to
provide a high standard for roadways throughout the city. The city progr.am,
forecasted for completion by 1985, will provide for paving of all unpaved
streets and general upgrading of the city link network. The program has
already accounted for a decrease in unpaved road mileage in the city from
550 miles in 1960 to 191 in 1976.
The County Roadway Program includes a modest street paving effort
amounting to approximately 50 miles per year (including those streets
paved by private development). The County Highway Department is presently
engaged in a modest test program to evaluate highway alternative chemical
stabilizers as dust retardants and as preparation bases for asphaltic
composition road surfaces. Cement stabilization, lime, enzymes, and tree
sap have been tried as dust palliatives, without success, and also appear
to show little promise as stabilizer bases for bituminous asphaltic surfaces.
The stabilizers wear quickly under the abrasive action of motor vehicle
travel and retain their effectiveness only briefly before repeated applica-
tion is necessary [1]. The cost of effective dust control using road soil
stabilizers varies with the average vehicle traffic. An initial application
may cost from $2000 to $4000 per mile, depending on the type of stabilizer
and the surface preparation provided.
The Arizona Department of Transportation has recently funded a study [13]
in which various chemical stabilizers were tested for dust control on unpaved
roads. The stabilizers were applied to sections of an unpaved road with an
2-3
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average daily traffic of 140 vehicles and a surface soil silt content of
28%. Some of the chemicals were applied by spray, while others were mixed
to a three inch depth after ripping the roadbed surface. Hi-Vol and dust
collector measurements were utilized to evaluate the dust suppressing
ability of the stabilizers with the road subject to normal traffic condi-
tions. The performance of the stabilizer products is shown in Tables 2-2
and 2-3. As a spray treatment, dust control oil demonstrated the highest
degree of dust control on the road surface both after the 5 month and 14
month observation periods. This palliative also was superior in terms of
least cost. As a stabilizer which is mixed.into the roadbed, the Redicote
E52 Asphalt Stabilizer Emulsion provides superior dust control, especially
for the longer observation period. The stabilizer exhibiting the best
performance for dust control also performed significantly better in terms of
road surface preservation. The dust palliatives tested are available com-
mercially and can be applied at costs ranging from $4,300 to $10,300 per
mile of 2 lane roadway. Since these palliatives must generally be applied
once annually (for roads carrying 150 ADT), it is clear that the substantial
annual cost of this measure should be carefully evaluated against alterna-
tives before it is applied.
The city of Phoenix is currently engaged in a modest program to treat
a limited number of unpaved roads where dust emissions have been particularly
offensive. Dust control stabilizers are applied with the use of a boot
truck equipped with a spray bar. The street surface is prepared prior to
application by surface blading or by ripping, depending on whether the
application is a surface treatment or a soil penetration mix. After
application of the stabilizer, the street surface is compacted using a
roller.
The city of Phoenix is currently using Dust Control Oil (RD-1000) sup-
plied by Standard Oil as it has proven to be a satisfactory dust palliative
in the past. The State Department of Transportation is also using the Dust
Control Oil in the Phoenix area to stabilize 400 acres of cleared right of
way for the future Maricopa Freeway. This treatment was applied in 1974,
yet the soil still exhibits a crust and has been observed to be stable
during heavy winds. Because the oil application was very light (.1 to 25
o
gal/yd ), the crust is easily disturbed by pedestrian or vehicle traffic.
2-4
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TABLE 2-2. PERFORMANCE RATING AND RQAD CONDITIONS FOR SELECTED ROAD DUST PALLIATIVE,
SPRAY ON APPLICATIONS [13]
ro
i
en
Chenical
Dust Control Oil
fixture of petroleum
resin and light hydrocarbon
solvent. Applied at .6 gal/
yd. 2.
Curasol AE
A oolymer dispersion di-
luted in water by .6 to 1 .
Applied in 4 passes at .25
gal/yds2' each.
Aerospray 70
A polyvinyl Acetate
resin diluted 6 to 1 with
water. Applied using 4 passes
at .25 gal/yd each.
Dust Bond 100 + F-125
Mixture of lignin sulfate
and other chemicals. Applied
non diluted in first pass at
1 gas/ydz- then at 1 to 1 di-
lution plus 2.5'* formula 125 on
next pass. Surface compacted
intermittently for several
nours after application
Foramine 99-194
A urea-formaldehyde resin
in water solution. Diluted
1.6 .to 1 by w.ater appli-
cation at 1 gal/yd'-
Water
Cost of Chemical
& Application3-
S/mt.
5?80
8130
8080
8420
10300
400
After 5 Months
Percentage
Control0' Description of Road Condition
95.2 Black, very hard surface, some
potholes near shoulders, min-
imal loose material, extremely
light dust behind traffic.
86.9 Dark brown, medium hard surface,
rutted with few potholes, loose
coarse particles on surface,
moderate dust behind traffic.
82.6 Brown, medium hard surface,
medium wear and ruts, few pot-
holes, loose coarse particles
on surface, moderate dust be-
hind traffic.
88.0 Brown, medium hard surface, mod-
erate wear, few potholes, smooth
surface, slippery when wet, mod-
erate dust behind traffic.
46.6 Natural color, worn and rutted
surface, large amount of loose
particles, poor riding quality,
heavy dust behind traffic.
0 Natural color, soft when wet,
worn and rutted surface, large
amount of loose particles,
heavy dust cloud behind traffic.
After 14 Months and Several Bladlngs
"ercentaqe
Control1-- Description of Road Condition
54.3 Dark brown, hard surface, scattered
potholes, moderate loose material
but from outside the road, light
dust behind traffic.
9.4 Brown, several ruts and potholes,
large amount of loose particles,
very heavy dust behind traffic.
44.3 Lt. Brown several ruts and potholes,
large amount of loose particles,
heavy dust behind traffic.
17.6 Lt brown, few patches of treated
surface, several ruts, large a-
mount of loose particles, heavy
dust behind traffic.
8.9 Natural color, similar to untreated
(water) section.
0 Natural color, worn, numerous ruts
and potholes, large amount of loose
particles, heavy dust cloud behind
traffic.
Cost effectiveness6'
$/ton of dust
Emissions Prevented
9.3
23.8
18.0
22.4
52.2
Based on State cost figures [13] for chemical stabilizers, adjusted 15% upward to reflect current (1976 costs, and another 10% to Include
cost of surface preparation ano applications. Correction for adjustment to current costs 1s based on personal communication with a principal
supplier [I4j. Costs include shipping expenses for supplier to Phoenix.
Cost effectiveness Is based on the ratio of the cost and the average emissions reduction attained for the period Indicated. This reduction is
estimated by applying the control figures above to the uncontrolled dust emissions corresponding to an unpaved road with ADT of 140, soil silt
content of 28%, and average vehicle speed of 35 mph (see reference [10]. The uncontrolled emissions are 254 tons per mile of road for the 5
month period, and 712 for the 14 month period.
Control effectiveness 1s based on dustfall measurements conducted at various distances from road.
-------
TABLE 2-3. PERFORMANCE RATINGS AND ROAD CONDITIONS FOR SELECTED ROAD SOIL STABILIZERS,
MIXED INTO SOIL3- [13]
Chemicals
Redlcote E52 Asphalt Emulsion
A cationic asphalt emulsion
(7.4^ In water) applied at
2.4 gal/yd2-
Dust Bond 100 + F-125
A misture of lignin sulfonatp
and other chemicals plus
formula 125. Applied at
1 gal/yd .
Dust Control Oil
Mixture of petroleum resin
and light hydrocarbon solvent.
Applied at .5 gal/yd2-
Water
Cost of Chemical.
and its application
$/mi
10810
8440
4370
600
Percent .
Control '
94.7
86.6
80.5
0
After 5 Months
Description of Road Condition
Black, very hard, asphalt like
surface, little wear, smooth
no loose material, no dust behind
traffic.
Brown, hard surface, smooth,
little wear, some loose material,
very light dust behind traffic.
k
Black, hard at,spots, few ruts
and potholes, loose course material
moderate dust behind traffic
Natural color, rutted, several pot-
holes substantial loose material,
heavy dust behind traffic.
"ercent
Control a-
84.4
44.7
11.5
0
After 14 Months
Description of Road Conditions
After Several Bladings 9/29/75
Black very hard, asphalt like surface,
little wear, good riding quality, some
loose coarse material, very little dust
behind traffic.
Brown, few hard spots, numerous ruts
and potholes, heavy dust concentration
behind traffic.
Dark brown, hard at few spots, numerous
ruts and potholes, heavy dust cloud
behind traffic.
Natural color, rutted, numerous potholes,
substantial loose material, heavy dust
cloud behind traffic.
Cost effectiveness
$/ton of dust emissions
Prevented
17.0
18.1
13.4
ro
cr>
b.
Mixing of the chemical stabilizer into the road bed is accomplished as follows: 1) the surface is first ripped to a depth of 3 Inches; 2)- the surface
is sprayed with water; 3) the chemical is sprayed on the surface; 4) the chemical is mixed into the soil surface with a series of successive bladings;
5) the road surface is compacted by rolling.
Based on state cost figures [13] for chemical stabilizers, adjusted 15* upward to reflect current (1976) costs, and, adjusted another 10% to include
cost of surface preparation and chemical application.Correction to current costs are based on communication with a principal supplier [14]. Costs
Include shipping expenses from supplier to Phoenix. .
Cost effectiveness 1s based on the ratio of the cost and the average emissions reduction attained for the period indicated. This reduction 1s estimated
by applying the control figures above to the uncontrolled dust emissions corresponding to an unpaved road with ADT of 140, soil silt content 28%, and
average vehicle speed of 35 mph (see reference [10]. Roadway dust emissions without control are 712 tons for the 14 month period.
Control effectiveness is based on dustfall measurements conducted at various distances from road.
-------
This crust is, however, re-established after rainfall provided the soil is
not disturbed by frequent traffic.
The tests by the State Department of Transportation show clearly that
chemical soil stabilizers may be used as an effective control for unpaved
road dust emissions. In some cases the stabilizer also serves to preserve
the road surface, resulting in lower road maintenance cost. Of the various
chemicals tested by the state, the Dust Control spray application is by far
the most cost effective in terms of dust control. The most effective
performer was the mix-in application of Redicote Asphalt Emulsion, which
was controlling dust emissions by 85% after a 14 month period. The main
drawback to use of the effective stabilizer is cost. Repeated applications
of the chemicals, even at reduced rates, impose costs which approach or
exceed the annualized cost of a paved road.
In addition to chemical road stabilizers, the county and city have
each considered low-cost paving alternatives. The most widely used low
cost pavement is the bituminous asphaltic chip seal over a granular
base or a stabilized soil base. Figure 2-1 shows a profile of this chip
seal construction. A penetration stabilizer (liquid asphalt MC-250) is
applied to the 6 to 8 inch base, followed by a chip seal.
\ Er./jf/r.a Bosc MafsriaJ_
Figure 2-1. Profile of Typical Section for Chip Seal Road Surface
Construction.
2-7
-------
TABLE 2-4. COST OF CITY STREET MAINTENANCE IN PHOENIX, 1974-75 FISCAL YEAR [2]
MAJOR:
Fully improved
Bituminous Surface Treatment
Oiled Roadway
No. Surface Treatment (graded)
Total
COLLECTOR
Fully improved
Bituminous Surface Treatment
Oiled Roadv.'ay
No Surface Treatment (graded)
Total
LOCAL:.
Fully improved
Bituminous Surface Treatment
Oiled Roadway
No Surface Treatment (graded)'
Total
GRAND TOTAL
Miles
397
13
5
5
TFO"
200
28
8
1
237
1,772
15
35
116
T7913"
.2,595
% of Total
City Miles
15.3 >
0.5.
0.2
0.2
T672
"
7.7
1.1
0.3 "
-
68.3 - ..
0.6
1.3
. 4.5
74.7
: '100.0
City Cost
For Period
$1,296,027
42,743
13,531
19_,_69P.
$ 182,737
45,688
2,427
8,702
$ 239,554
$ 541,499 '
44,570
40,503
. 222,663
5 849,2.35
: .'$2,460,730
% of Total
City Cost
52.7
1.7
0.5
0.8
. 5577'
7.4
1.9
0.1
0.4
9.8
. \ i
22.0
1.8
1.7
9.0
34. b'
::100.0
Co3t Per nile
For Period
$3,265
3,223
2,705 '
3, '333
$1,267
$ 913
1,632
303
8^702
51,011
$, 306
2,971
1,157
1,920
$ ~'4jd
.'$ 948
ro
i
oo
Note: Above figures do not include cost of Preventive Maintenance by Contract,
-------
The city has rejected the chip seal approach on the basis of its high
annual maintenance costs and poor performance characteristics. Table 2-4
shows the high maintenance costs incurred during 1974-1975 for the four major
types of road construction in the city of Phoenix. However, the county is
experimenting with the bituminous chip seal for roads with low vehicle traffic
counts (100 vehicles/day), and finding it satisfactory in applications
throughout the county. Maintenance requirements depend on vehicle traffic
and locale, but generally include a second chip seal after one year, followed
by another seal in approximately 5 years.
A study conducted by the city of Seattle Engineering Department has
shown the most cost effective method of dust control on roadways is a chip
seal when the average daily traffic is 150 vehicles. This dust control option
is also economically beneficial, considering the estimated annual savings of
$2,665/yr/mi in maintenance costs resulting from the measure. A Duwamish
Valley study [3] has shown annual maintenance costs of various types of
roadways diminishes appreciably with the quality of the road surface.
Table 2-5 shows the annual maintenance costs derived from this study. The
study also includes a cost analysis of benefits gained by dust control for
Duwamish roadways. These benefits were estimated to translate to over
$3.88 million/year to the community, and demonstrate clearly that paving
of roads is a good investment.
TABLE 2-5. ANNUAL MAINTENANCE COSTS FOR VARIOUS ROAD3
SURFACES [3] IN DUWAMISH VALLEY
TYPE OF ROAD COST IN $/MI
Gravel Road 2900
Oiled Surface 1100
Seal Coat 245
3 inch Asphalt 245
6 inch Concrete and Curbs 100
a. Costs are given for standard 2-1ane road
2-9
-------
While it is possible to show the high cost of roadway dust control
programs is economically beneficial, the most cost effective control measures
are difficult to determine. The Duwamish Valley Study estimated that
oiling of unpaved roads with an average daily traffic over 15 vehicles is
the least cost way to reduce dust levels. As traffic increases, maintenance
costs required to sustain dust control throughout the year increases until
the least cost dust control consists of a chip seal surface at 150 ADT, and
with still more vehicle traffic, an asphalt surface. Typical cost estimates
for initial construction and maintenance of the different road types in
Phoenix are shown in Table 2-6. It is apparent that maintenance costs
contrast sharply with those reported in Phoenix City (Table 2-4) and the
Duwamish Valley .(Table 2-5). This is due to the diversity of maintenance
practices and requirements from one region to another, and the differing
cost of resources.
TABLE 2-6. INITIAL COST AND MAINTENANCE COST OF ALTERNATIVE
ROAD SURFACES APPLIED BY MARICOPA COUNTY HIGHWAY
DEPARTMENT [1, 13]
TYPE OF ROAD
Gravel Koad
Oiled Surface (Low Cost
Application)
Oiled Surface Dust Control Oil
Chip Seal Coat
3" Asphalt
COST ($/MI)
16,000
2000-3000
5,300
35,000
55,000-100,000
ANNUAL MAINTENANCE
($/MI)
600
2000-3000
5,300
800
160
Control efficiency estimates for the various dust measures are tabulated
by considering the effect of altering a road which is presently an unpaved
dirt surface having a silt content about twice that of a gravel road (re-
presentative of the Phoenix area). Cost effectiveness is then estimated by
considering the annualized cost of the measure in the given study area and
the resulting emissions reduction. Efficiencies and cost effectiveness
2-10
-------
estimates are shown in Table 2-7. The chip seal surface appears to be
somewhat more cost effective than the other road surfacing dust control
measures, and of those measures providing the best control, the chip seal
is significantly more cost effective. These findings are consistent with
the Duwamish Valley Study [3] where it was found that the least cost con-
trol was a chip seal surfacing when ADT is over 100. However, for lower ADT,
lighter applications of the road dust palliatives may be used to
attain a certain level of dust control and cost effectiveness of the
palliative in this instance becomes competitive with the chip seal paving
approach.
TABLE 2-7. EFFECTIVENESS OF ALTERNATIVE ROAD SURFACES IN REDUCING
DUST EMISSIONS FROM AN UNPAVED ROAD IN MARICOPA COUNTY
EMISSION RATE
ROAD TYPE LB/VEHICLE MI.
Dirt Surface
Gravel
Oil Surface (Dust Control
Oil)
Oiled Surface (Low Cost
Application)
Chip Seal
Asphalt
22a
lla
5f
nb
oe
oe
ANNUAL
EFFICIENCY
50%
75%
50%
100%
100%
COST EFFECTIVENESS0
$/TON OF DUST
11.0
19.5
13.5
10. 8d
19. 6d
' Based on MRI emission factor [6], and road silt content of 24% and
average vehicle speed of 35 mph.
' From reference [4].
c* Computations based on assumption of ADT of 100, maintenance costs of
Table 2-6, and annualized cost of indefinite period at 10% interest.
" These figures do not incude the dust reductions attained by inducement
of traffic off unpaved roads to the newly paved surface.
e> This emission rate does not include entrainment of dust loadings off
the pavement. Entrained dust emissions are discussed in Section 2.2.
' Based on field test conducted by Arizona Department of Transportation [13],
2-11
-------
Traffic controls also offer potential for dust emissions reduction
from unpaved roads. Dust emissions increase exponentially with vehicle
speed up to 30 mph [5,6]. Table 2-8 illustrates the dust emission rate at
different speeds for a vehicle traveling over a dirt road characteristic of
the Phoenix area. Based on an average speed of 35 mph, the reduction
achieved by restricting vehicle speed to 20 mph would be 62%.
Restriction of use of unpaved roads may also be employed to reduce
dust emissions. Unpaved roads may be closed to travel when alternative
paved routes are available. The potential of this dust control measure is
not encouraging since almost all roads provide needed access to at least
a limited segment of the population, and it is not plausible to restrict
traffic to only this limited sector. It should be noted, however, that
traffic volume on the remaining interior unpaved roads will be diverted
significantly after addition of paved routes to the road network. Such
traffic inducement should be considered in assessing the total effectiveness
of the road-surfacing measures. For example, a plan to pave half the
section line roads in Maricopa County (Arizona) by 1985 would reduce expected
traffic on remaining interior unpaved roads by 15%. This analysis is made
by considering the trip alternatives in a representative section of the
road network for the "before and after" paving control measure (Section 3.3).
TABLE 2-8. DUST EMISSION RATES AT DIFFERENT VEHICLE SPEEDS
SPEED OF
VEHICLE
35
30
25
20
EMISSION RATE3
LB/VEHICLE MI.
22
19
13
8.5
DEGREE OF EMISSIONS
REDUCTION
.
14%
41%
62%
1
The emission rate is based on the MRI emission factor [13] for vehicle
speeds of 30 mph and over. For speeds from 0 to 30 mph the emission
rate increases exponentially with speed and is calculated as follows:
e = .0211 S2, where e = emission rate (Ib/vehicle mi.), and S = vehicle
speed (mph). The baseline emission rate (35 mph) was calculated as-
suming a typical dirt road silt level of 24%.
2-12
-------
2.2 CONTROL OF ENTRAINED DUST OFF PAVED STREETS
The amount of entrained dust entering the atmosphere from paved
streets is proportional to the traffic volume and the street surface dust
loading [20]. Both of these parameters vary substantially from region to
region, as well as within the region itself. Figure 2-2 illustrates street
dust loadings measured [8] in various cities differing in age, size, locale,
meteorology, and land use patterns. The average dust loadings of the cities
sampled was 1500 Ib/curb mile, and for Phoenix, 780 Ib/curb mile.
The variation of dust loadings by different land use categories is
illustrated in Figure 2-3. Streets in industrial areas tend to be most
heavily loaded, while commercial streets are least heavily loaded. This
pattern is consistent with land use and street sweeping practices. Com-
mercial areas are swept frequently while, industrial areas receive less
cleaning attention. These patterns suggest the control of entrained dust
by two methods: 1) control of the street dust origins, and 2) modification
of street sweeping practices.
Control of the Dust Origins
One obvious means of reducing street dust loadings is by controll-
ing the dust sources. Significant origins consist of carryout of dust
from dirt surfaces by motor vehicles, atmospheric fallout of airborne
particulates, and transport from adjacent exposed land areas. In
Phoenix, the major sources of dust originate from dust fallout of local
source emissions and from transport of exposed soil areas near the
streets. There are presently 470 miles of city streets with unpaved
shoulders in the cities of the study are*.. Over half of these roads
are major streets experiencing substantial traffic volume. Dust from
the exposed road shoulders is transported to the street surface by
air turbulence from passing vehicles, wind erosion, tracking by^ped-
estrians and vehicles, and water runoff. In addition, there are
numerous exposed vacant lots throughout Phoenix which contribute to dust
transport on nearby street surfaces.
2-13
-------
f
Z
Z
o
<
O
^
97
i ~
0 e
0
4000
-6000
2000
1000
0
'<
i
"
Si > ° rf «1
0 J « n <
Figure 2-2. Street Dust Loadings for
Various Cities in U.S. [8].
.2-"14
-------
4000
3000
RESIDENTIAL
>-
h-
t/»
f1
UJ
o 2
5 o
*_J *
GO
rooo
INDUSTRIAL f'.-i
£1
COMMERCIAL
M
h
H
H
0.
_u
o
r
o
>
5
O
Fill ii
1 !j [| I
-1 1^3 i.n* L^
JS '^ t
171 "5 "i ~c<
S J :E ^
T ^ x
S' "°
t> . o , o
< > -i-
-o f, '>
o E
( j
[1 F
Ml
Hi
11 li 0
e >- £
.- O "£
g ? £
5? u
E
o
c
'5.
_c
0
,
^f
T3
li
C
V*
o
_n
Figure 2-3. Street Dust Loadings for Various Land-Use Categories,
Summary of Several Cities in U.S. [8].
2-15
-------
Roadway improvements anticipated over the next ten years will result
in significant impacts on street dust loadings. The mileages of uncurbed
streets in the cities of the study area will change as follows:
ROAD TYPE MILES OF UNCURBED CITY STREETS
Local
. Collectors and Majors
1975
142
329
1980
72
260
1985
0
191
Source: Support Document #2 [10].
These improvements are important because dust loadings for streets
with uncurbed shoulders are estimated to be four times greater than that
observed for curbed streets [9]. While local roads play a minor role in
total dust resuspension (due to low VMT on~those roads) the improvement of
road shoulders for collectors and major streets is expected to decrease
the city-wide entrainment emission factor from 11.1 g/vehicle mile.
in 1975 to 8.7 g/vehicle miles in 1985, [10], Table 2-9 summarizes the
reduction in area-wide dust resuspension factors which would occur with
an intensified city program to curb all major roads and collectors by 1985.
While this emission factor applies only to city traffic, the substantial
portion of vehicle miles traveled in the study area are concentrated within
the cities. Hence, reductions in street dust loadings in the cities would
have far greater impact on TSP levels than would similar reductions in the
county road network.
TABLE 2-9. EFFECT OF ROAD SHOULDER IMPROVEMENTS ON DUST
RESUSPENSION FACTORS FOR CITY STREETS
TOTAL UNCURBED WEIGHTED DUST
MILES IN CITY SUSPENSION RATE
gm/VEHICLE-MI.
Baseyear 1975
Baseline, 1985
After Program to Curb all Roads
(Major & Collector by 1985)
329
191
0
11.1
8.7
5.3
2-16
-------
Based on present city construction costs of $5/curb foot [11], the
additional cost of improving all remaining unpaved road shoulders with
curbs in the city by 1985 would be approximately $5 million. This compares
to the projected plan of the city of Phoenix to spend $57 million on
local street improvements and $167 million on major streets [11, 12]
by 1985.
To increase the effectiveness of street curbings as a dust con-
trol measure, the adjacent soil should be stabilized or covered to
prevent wind erosion or tracking of this soil onto the street. Clearly,
the most effective means of soil protection at the curb is a sidewalk.
The current city policy is to include sidewalks whenever curbs are
constructed on major streets. The cost of sidewalk construction is $6
per running foot of the standard 5 foot wide sidewalk. Quantification
of the effectiveness of this measure is not possible but it is clear
that transfer of exposed soil to adjacent road surfaces will be decreased
significantly.
Street Sweeping
There are three main types of machine street sweepers currently
in use. Broom sweepers utilize a rotating gutter broom to sweep debri
from the gutter into the main pickup broom which rotates to carry the
debris into the truck hopper. The broom sweeper is by far the most
commonly used class of sweeper. A second type of sweeper, called the
air broom uses an air blast to direct debris into a collection hopper.
A third type of sweeper utilizes a broom and vacuum system to collect
debris. Each of the sv/eepers employs a water spray to control dust
emissions during sweeping. A number of operational and equipment
factors have an appreciable impact on street sweeping effectiveness.
2-17
-------
These factors include operator performance, forward speed, type of
sweeper, and condition of broom. The most important operational
factor in sweeping efficiency concerns level of effort. Level of effort
in cleaning the road (expressed in terms of cleaning time per area)
is related to the weight of material collected by:
M = M* + (M - M*) e"kE
*
Where M is the initial street loading, M is the loading unremovable
by any amount of sweeping, k is an empirical constant dependent on
sweeper characteristics, and E the amount of sweeping effort [8].
The exponential effect of sweep effort on collection efficiency
for a broom sweeper is illustrated in Figure 2-4. For the normal
street sweeping operation, a single sweep pass is performed, yielding
approximately a 50% collection efficiency (for typical operating speed).
Adding a seocnd pass to the cleaning operation, or doubling the effort,
improves efficiency to 75%. For the vacuum sweeper, collection ef-
ficiency is relatively constant regardless of level of effort for
vehicle speeds 6 mph and less [18].
100 ;
u
c
Ol
U Q.
o
o
75
30
25
Based*on;
M = M +
MQ = 10.0 g/ft
M* = 0.5 g/ft
- M
2
012345
Number of passes (P)
FIGURE 2-4. Effect of Level of Effort on Col.lection
Efficiency of Broom Sweeper [8].
-------
Sweeper collection efficiency is also related to particle size of the
street load. Table 2-10 shows the efficiency of a broom sweeper for different
particle size ranges. It is clear that the broom sweeper is ineffective in
removing those particles which are most likely to become airborne (<100y)
by passing vehicles. In fact, the broom sweeper tends to fracture aggregated
fines causing slight increases in the concentration of smaller particles
after sweeping. In addition, the sweeper tends to redistribute the remaining
dust over the surface of the street, making it more susceptible to atmospheric
reentrainment by passing vehicles. While limited studies of the vacuum type
sweepers have been conducted, these controlled experiments demonstrate a
dramatic difference in the performance of the vacuum broom sweeper for col-
lecting smaller particles. Table 2-11 shows the vacuum sweeper will collect
roughly twice the small size material of the broom sweeper (when the broom
effort is equivalent to about a 2 pass operation). The vacuum sweepers
are most effective under dry conditions for loose dust.
TABLE 2-10. EFFICIENCY OF BROOM SWEEPER FOR VARIOUS
PARTICLE SIZES [8]
PARTICLE SIZE
- (P)
>2,000
840 - 2,000
246 - 840
104 - 246
43 - 104
<43
IN SITU TEST
78.8
66.4
69.5
47.7
< 0
< 0
EQUATION
--
49.2
48.7
22.2
15.8
COMPOSITE
(estimate)
79
66
60
48
20
15
2-19
-------
TABLE 2-11. COMPARISON OF REMOVAL EFFECTIVENESS FOR MOTORIZED SWEEPING AND
VACCUMIZED SWEEPING [9].
ro
i
ro
o
MACHINE
TYPE
Motorized
Vacuumi zed
Motorized
Vacummized
RELATIVE
EFFORT
2.17
2.88
4.32
5.83
20 g/ft2
177-300vt
""(I)
92.5
95.0
94.5
98.5
100 g/ft2
74-177V
(%)
58.0
94.5
-
-
600 g/ft2
74-1 77v
(%)
46.0
89.5
62.6
91.4
NOTE: Tests conducted on asphaltic concrete. Results are for 1 pass
in 2nd gear and 1 pass in 3rd gear.
g/ft2 = Initial mass level.
vi = Particle size range of simulant.,
(M - M)
% = Removal effectiveness = _2 x TOO
Mo
Relative
Effort = effort (time spent by sweeper covering a given area)
relative to the minimum level of effort attainable
by the sweeping equipment. For the tests above, unit
relative equipment effort corresponds to a forward
speed of 1200 ft/min. Therefore, relative effort =
1200/forward speed (ft/min.).
-------
The city presently operates: Z3 motorized broom sweepers on a full
time all day basis. The sweepers generally perform a single pass during
cleaning-. Major streets and collectors receivimr heavy traffic are
generally swept by night, and low-use major collectors, and local streets
are cleaned by day. The locarl streets, are swept/monthly,, most- collectors
every 2. weeks , the major streets every 7 days;.. Some of the^. Mglfc-use
streets aret cleatredr 3 tfmesr per* weetei :an&- & tfmftedr number are? sweplr
darty, The* eostr of- this, pcegapanr is &V J^ BirVH-eifc per1 year ^
The effect of street cleaning frequency on street dust loadings
is illustrated hypothetical ly below (Figure 2-5). The loading intensity
increases: rapidly approaching an equilibrium level after- sweeping. The
atcet;. eat . teypiiiea.'V, cirt^p. Sstrpgts. ha.v.p^-hppti. ^^d^Ptfe. r^trpftt.liT^
furtdln§ b^tfeerEkv-iniuiiiaPbl^^^ E^K Tyg^eai-
Tatiorr rates after a complete- cleaning are shown in Figure 2-6.
0)
-a.
w
o
Figure 2-5". Accumulation of Particulates (Shown with Periodic
Sweeping)
2-21
-------
rv>
i
ro
ro
01
=3
O
I/)
I/)
Q
O
O
LU
£
O
O
MOO
l?00
1000
eoo -
ELAPSED TIME SINCE LAST CLEANING BY SWEEPING OR RAIN (days)
Figure 2-6. Street Dust Loading Versus Time Since Last Sweeping [8]
-------
Figure 2-7 shows the effect of frequent sweeping with a broom sweeper
on a street with typical dust loading levels. The diagrams of Figure 2-7
have been formulated by applying a collection efficiency of 50% to the accum-
ulation schedule in Figure 2-6. When broom sweepers are used, a 48% total
dust loading reduction would occur by shifting from a 10 day cleaning cycle
to a 3 day cycle. In combination with a double pass of the broom sweeper,
the increased cleaning frequency would reduce average total street dust
loadings still more. Figure 2-8 shows the effect of frequent sweeping with
vacuum sweepers on a street with typical dust loading levels. These curves
are based on collection efficiency data shown in Table 2-11 and reported in
reference [18], and the average street accumulation rates shown in Figure 2-6.
A 58% total loading reduction would occur by shifting from the current
sweeping cycle to a 3 day cleaning cycle.
The information from Figures 2-7 and 2-8 are presented in summary form
in Figure 2-9 to permit extrapolation of total street dust loadings associated
with any given street sweeping schedule.
The reduction in street dust loadings affects entrainment of dust by
motor vehicles according to the relation developed by MRI [20].
E = KLS
Where E = suspended dust per vehicle mile
K = an empirical proportionality factor
L = street dust loading
S = silt content of dust (percentage of particles less
than 75y).
Emissions of street dust decrease with total street dust loading reductions
accomplished by street cleaning programs. However, intensification of street
sweeping will probably raise the average silt content of the street dust.
Immediately after sweeping, the remaining dust is comprised of a higher per-
centage of fines as most of the heavier larger particules are removed during
sweeping. Tables 2-10 and 2-11 show that the broom sweeper is far less ef-
fective at collecting smaller particles than the vacuum sweeper. For a
single pass of the broom sweeper, only 20% of the particles smaller than
100 micron were expected to be removed, and during field tests [8], it
2-23
-------
a
<
o
12CC-*-
1000-
SCO-
SCO-
(Sl
a 400
BASELINE AVERAGE STREET LOADING = 360 L3/MILE
(SINGLE PASS) ' -
AVERAGE = 720 LB/MILE I
(DOUBLE PASS)
I
20°" SINGLE OR DOUBLE PASS OF SWEEPER AND CLEANING IACH 10 DAYS
H h
10
DAYS
.AVERAGE STREET LOADING = W5 L3/MILE
2CC" SINGLE PASS OF SWEEPER AND CLEANING EACH 3 DAYS
H 1 1 1-
I I
10
DAYS
<
o
iCC-
AVERAGE STREET LOADING = 34G L3/MILE
:CL3LE PASS OF SWEEPER AND CLEANING EACH 3 DAYS
GOO .
400
200 -
AVERAGE DUST/LOADING - 305 LB/CURB-MILE
SINGLE PASS OF SWEEPER AND CLEANING EACH DAY
M 1 1 1 1 1 1 1 1 K
4 C
DAYS
10
Figure 2-7. Effect of Intensification of Broom Sweeping
on Street Dust Loadings
2-24
-------
BASELINE AVERAGE DUST LOADING
(BROOM SWEEPER)
360 L3/MILE
300 +
500-
400-1-
200+/
X
X
AVERAGE DUST LOADING = 615 LB/MILE
(VACUUM SWEEPER)
V
2. ' 4 6 8 T°
3IMGLE PASS OF SWEEPER AND CLEANING EVERY 10 DAYS
AVERAGE DUST LOADING = 360 L3/MILE
2 4 63
VACUUM CLEANING EACH THREE DAYS .
600
400
200
AVERAGE DUST LOADING = 160 LB/CURB MILE
Figure 2-8.
VACUUI CLEANING EACH DAY
Effect of Intensification of Vacuum Sweeping
on Street Dust Loadings
2-25
-------
t\5
£800..
^600..
H 1 1 1-
I I 1 I 1-
B
8
10
DAYS BETWEEN EACH SWEEPING
Figure 2-9. Effect of Sweeping Frequency on Average Total Street Dust Loadings
-------
was found that a street cleaning by the broom sweeper actually increased
loading concentrations of the particles smaller than 100 micron. This caused
substantial shifts in the silt content of the street dust, as shown in
Table 2-12. The higher silt values, increasing in some instances immediately
after sweeping by factors of 2 to 6, partially cancel!, at least temporarily,
the dust control benefits achieved by broom sweeping cleaning operations.
As accumulation of new materials occurs, equilibrium between deposition
rates and traffic related removal rates is once again achieved, returning
the silt levels within the range of 10 to 15%. However, with frequent
sweeping, the average silt levels of street dust may be significantly higher
than for normal street sweeping. It is not possible, using available
data, to assess the effective silt value occurring with more frequent
street sweeping. Studies now underway by the Environmental Protection
Agency should reveal more information on this subject.
TABLE 2-12. COLLECTION EFFICIENCY OF BROOM SWEEPER FOR VARIOUS
PARTICLE SIZES [8].
ATLANTA
rASTICLE
SIZE RANGE
(micron)
>2,COO
890-2.000
246-090
101-246
13-104
<«3
Total (S)
Overall Eff; (!) .
>104
<104
I silt*
1MMAL
LOADING
<9>
175
103
375
231
66
43
993
884
109
11
RESIDUAL
LOADING
(9)
76
14
56
29
136
187
438
50
175
323
67
INITIAL
LOADING
-------
Increased levels of silt content resulting from frequent broom sweeping
operations can be reduced substantially by employing vacuumized sweepers.
Table 2-13 shows the effect of vacuum sweeping for various particle size
ranges. The data is based on claims of Ecolotec, Inc., manufacturer of
commercial vacuum sweepers. For a street loading similar to that found in
Phoenix (768 Ib/mi) the vacuum sweeper collects approximately 80% of the
particles smaller than 45y. Therefore, the vacuum sweeper would have only
minor effects on the average silt level of road dust, while at the same
time this sweeper would reduce total street dust loadings substantially.
Consequently, the street dust loading reductions attained by a vacuum
sweeper program (Figure 2-9) will translate directly into emission reductions,
TABLE 2-13. EFFECT OF VACUUM SWEEPER OPERATIONS ON STREET DUST
LOADINGS [18].
OPERATING CONDITIONS
DEBRIS REMAINING
Vehicle Speed
MPH
3
3
3
3
3
3
3
3
3
1
1
1
6
6
Air Velocity
MPH -
115
115
115
134
134
134
186
186
186
134
147
171
147
171
Dirt Loading
#/mi .
768
1536
3072
768
1536
3072
768
1536
3072
3072
3072
3072
3072
3072
Overall
%
7.3
6.4
5.5
8.9
5.0
2.1
6.1
4.0
2.4
3.2
2.4
2.8
2.5
7.0
>841y
%
4.8
3.2
1.5
6.4
3.4
1.1
5.4
3.7
1.5
3.4
!
^
.
44-840y
%
8.4
7.8,
7.1
10.0
5.5
2.4
6.1
3.8
2.7
2.9
-
-
-
_
<43y
%
21.8
16.7
19.2
24.8
16.7
9.2
20.0
12.1
8.6
4.6
-
!
- !
2-28
-------
Caution should be exercised in applying the evaluation procedures
developed here for entrained street dust emissions control. The avail-
able data base for existing street dust loadings and sweeper efficiencies
are very limited. While an average dust loading and silt level was as-
sumed based on limited field data, it is known there is substantial
variation from street to street. The information for sweeper efficiency
is unclear, particularly with respect to the impact of the sweeper types
on the temporal and average distribution of the particle sizes. As more
information becomes available, it may be possible to develop software to
compile emissions estimates for each link of the transportation network,
using traffic volume tapes,street-specific dust load levels, and sweeper
efficiency values as inputs to the procedure. However, a field approach
would be preferable to the complex analytical procedure. For example,
the control objective would be specified in terms of an allowable dust
load target, and street sweeping would be adjusted by reasonable trials
to obtain the objective. Field measurements would provide the basis for
determining the amount of actual sweeping required, rather than uncertain
analytical estimates.
The control effectiveness of various schedules of vacuum and broom
sweeping outlined above can be used only as a useful guideline in specifying
tentative and potential street cleaning requirements associated with an
allowable street dust emission rate.
The cost of street sweeping varies widely from city to city. Because
the full scale street vacuum sweeper has been marketed for a limited time
in the United States (beginning in 1971), nearly all cost data available
pertain to the conventional broom sweeper. The American City Survey [26,27]
showed sweeping costs varying from $2.18 to $8.42 per curb mile sweep.
This cost range is due to differences in maintenance practices, operators
pay, and accounting reporting practices. The average cost of sweeping
streets in the city of Phoenix (using broom sweepers) is $4.80 per curb
mile [15].
Street maintenance departments of various municipalities [30,31,32]
are presently reserved about the potential utility of the vacuum sweepers.
2-29
-------
It is generally agreed the vacuum sweeper is not capable of collecting
heavy loads (e.g., high piles of leaves or debri) or loads which adhere
to the street surface (e.g., mud or sticky substances). Added reluctance
to purchase the vacuum sweepers stems from the higher initial cost of the
sweeper, and the general viewpoint that it reflects new state-of-art
development. However, it is also widely acknowledged that the broom sweeper
has its drawbacks: 1) it is inefficient as a collector of dust and small
particulates, and 2) it is characterized by high maintenance costs, exces-
sive downtime, and short lifetime.
Few cities have experimented with the vacuum sweepers, but there is
indication from those that have that it may provide satisfactory performance
at overall costs roughly equivalent to that of the broom sweeper [28].
The initial cost of a broom sweeper suitable for city street maintenance
is about $32,000 to $40,000 depending on the manufacturer and type of
engine. Because many cities find the diesel engine more attractive economi-
cally, the capital cost is often close to $40,000. Initial cost of the
vacuum sweepers varies from about $49,000 - $58,000, depending on manu-
facturer and engine type. Maintenance costs for the broom sweeper are
acknowledged to be higher. In one study performed by the city of Columbus
(Ohio), the vacuum sweeper was reported to be operating at an average cost
of $6.60 per cubic yard of collected material versus $26.00 per cubic yard
reported for the broom sweepers [28]. Since the vacuum sweeper is new on
the market, it is not possible to factor in equipment lifetime values to
compute annualized costs. Manufacturer claims indicate the vacuum sweeper
may be extended to a 7 to 10 year life [29,33], while experience has shown
the broom sweepers are usually scrapped after a 5 to 6 year term. Based on
these claims, the manufacturers are promoting the vacuum sweep as the
least cost street cleaning method.
While the available cost data are unclear in the comparison of vacuum
versus broom sweep technology, there appears to be little doubt these alterna-
tives are competitive. For the purposes of this study, the annualized cost
of these two street cleaning approaches was considered equivalent-
2-30
-------
Table 2-14 summarizes cost estimates and emission reductions for various
scenario street sweeping measures applied throughout the city of Phoenix.
City-wide costs are shown here for illustrative purposes only, while any
actual control program would probably focus on specific areas where en-
trainment of dust must be controlled to attain air quality objectives.
The cost of intensifying street cleaning operations in the city of Phoenix
(Table 2-14) have been estimated based on a review of the existing budget
and performance, and a projection of that base data for more intensified
operations.
2.3 CONTROL OF DUST EMISSIONS FROM CONSTRUCTION ACTIVITIES.
Construction activities are temporary and variable in nature. Fugitive
dust is emitted both during the activities (e.g., excavation, vehicle opera-
tion, equipment operations) and as a result of wind erosion over the exposed
earth surfaces. Earth moving activities comprise the major source of con-
struction fugitive dust emissions, but traffic and general disturbance of
the soil also generate significant dust emissions.
Emissions of dust from construction activities are already controlled
by the Maricopa County Bureau of Air Pollution Control Rules and Regulations.
Rule 31a states:
...."No building or its appurtenances, a utility or open area may
be used, constructed, repaired, altered, or demolished without
taking all reasonable precautions to prevent particulate matter
from becoming windborne or airborne. Dust and other types of
particulates shall be kept to a minimum by such measures as
wetting down, covering, landscaping, paving, treating or by other
effective means."
Similarly rule 31B requires that reasonable precautions also be taken to pre-
vent particulate emissions during roadway construction activities.
2-31
-------
TABLE 2-14. COST EFFECTIVENESS OF VARIOUS CITY-WIDE STREET SWEEPING PLANS
Control Measurement
Annual
Cost of Entire Motorized
Sweeping Program in Mil-
1 ions of dollars
Reduction of Average
Street Dust .Loading
Expected
Reduction of
Dust Emissions
Expected
Cost Effectiveness
$/ton of dust em-
missions prevented
1. Existing Motorized Sweeping
Program .87
2. Intensified Broom Sweeping
a. Sweep all Majors & Collectors
each 3 days 2.6
b. Double pass with Sweeper on
48%
79
ro
i
c*>
ro
c.
existing cycle
2 and 3 above
1.7
5.1
16%
60%
16%
45%
67
95
3. Vacuum Sweeper Program
a.
' b.
Sweeps on existing schedule
Sweep each 3 days
.87b
2.6
29% '
58%
29%
58%
Od
39
a Based on budget for 1975 [15]. Cost estimates of more intensified sweeping measures above are expanded proportionally from this
base.
Based on assumption that annualized cost of vacuum sweeper is approximately equivalent to that of broom sweeper. This is pre-
dicated on the tradeoff between higher initial cost of a vacuum sweeper ($50,000) versus 40,000 for broom sweeper) and lower
annual maintenance and longer lifetime of vacuum sweeper.
c Dust emission reductions for broom sweeping have been estimated based on assumption that silt content(percentage of particles <75v)
of street loading reaches equilibrium level within one day of sweeping. The silt level varies from 10% to a level 4-1/2 times greater
(based on Table 2-12) immediately after sweeping. The equilibrium silt value is taken as 10% [20].
This measure does not incur additional costs because the vacuum sweepers can replace broom sweepers on a phase out program at no charge
Emissions preventions are based on 322 tons of resuspended dust originating in the cities of the study area each day. 204
tons/day are estimated to originate off the streets of the city of Phoenix.
-------
While the construction regulations do not specify a definite amount
of control which must be applied, construction contractors are currently
employing water trucks and appear to be complying with the intent of the
rule [11, 16]. The rule was tested in court following a challenge by a
contractor, who had been cited in violation of the rule. The court upheld
the rule, deciding that the contractor had not taken reasonable precautions
(i.e., wetting down soil) to prevent the dust from becoming airborne.
However, despite the support given by the court, the rule is enforced
rather loosely, especially on construction sites removed from populated
areas.
Wetting the surfaces of unpaved access routes for construction vehicles
and trucks is an effective control for dust emissions provided the surface
is maintained wet. In the arrid Southwest this generally requires appreci-
able water. A study on the effect of watering on construction sites [4],
indicates that extensive wetting of the soil may reduce dust emissions at
up to 60 to 70%. However, this result was far from consistent, as the
watering control caused no apparent effect on several occasions, resulting
in an average efficiency of only 30%. PEDCO [4] suggests that wetting of
access roads twice a day with an application of .5 gal of water per square
yard will suppress dust emissions by 50%. Another study [25] has shown
emissions from unpaved roadways are reduced by 30% when the surface was
maintained moist.
It is not clear what degree of compliance is presently being exercised
with respect to dust control on construction sites. Baseline calculations
for emissions from construction sites were based on emission factors derived
from a study of a construction site in the Phoenix area where some degree of
dust control measures were being employed. The effect of more extensive
wetting practices on baseline estimated dust emissions is entirely specula-
tive, although such a practice would surely incur significant additional
prevention of dust emissions off the construction site. For the purpose of
this study, it was conservatively assumed that dust emissions would generally
be reduced by 30% with strict enforcement and awareness of the construction
dust regulations, including the added provision that watering be conducted
twice a day at a rate of 1/2 gal/sq.yd.
2-33.
-------
A negative tradeoff associated with watering controls at construction
sites concerns the carry-out of mud onto adjacent streets. The carried out
dust is susceptible to suspension by passing vehicles. If the construction
site is frequented by appreciable traffic and watering controls are amply
employed, mud carryout will be significant and should be controlled.
Presently, rather minimal control is provided by loose enforcement of
Rule 31D (this rule requires materials deposited on public roads be removed
by the responsible party). One means of removing the dust carryout from
construction activities is street sweeping. Street sweepers may be employed
daily to clean those paved public roads where visible dust has accumulated
due to construction activities. To reduce cleanup costs, good housekeeping
measures (cleaning construction vehicles before leaving site) may be
employed as a cost effective alternative to street sweeping. It is not
possible to generalize an effectiveness for these actions.
An additional dust source at construction sites consists of exposed
earth which is susceptible to wind erosion, and to dust emissions from in-
frequent traffic disturbance. While the suspended dust from this source is
generally significant, there are brief periods (i.e., during wind gusts or
traffic bursts) when the resulting dust levels may create a nuisance to
nearby inhabitants. Dust emissions from these sources may be reduced by
combining two approaches. First, a soil stabilizer, such as a chemical
palliative or vegetation cover may be applied. A second approach would
involve a stipulation that cleared earth be exposed for a limited period
before subsequent operations on this land begin. This would prevent the
frequent practice of clearance of vast plots of land where subsequent
construction operations are not scheduled to begin for several months. Such
clearance may be allowed only if accompanied by soil stabilization measures
within two months of the clearning. The effectiveness of these measures
in reducing dust emissions is unknown.
The cost of the alternative dust control measures for construction site
dust emission is shown in Table 2-15.
2-34
-------
TABLE 2-15. COST OF ALTERNATIVE DUST CONTROL MEASURES FOR CONSTRUCTION EMISSIONS
DESCRIPTION OF MEASURE
CONTROL EFFICIENCY
COST
r\>
i
Co
en
Wetting of site access roads twice/day
at .5 gal/yd2, and strict enforcement
by Building Department and County Health
Department
Daily (if necessary) cleanup of public roads
to remove visible dust or mud deposits resulting
from construction activities.
Stabilization of all exposed earth on the
construction site wherever operations cease
on that land for more than 2 months.
30%
Unknown
Unknown
a.
$6/acrea'/day
$25/sweeping/
siteb-
$200-300/acre(
Based on 3 hours labor and equipment cost. Unlimited water is provided from irrigation canals to
contracting for a single annual permit cost.
Based on typical sweeping service rates ($25/hour) [34], and assumed sweeping effort of one hour.
Sweeping requirements will vary substantially depending on the magnitude and nature of construction
activities. Good housekeeping practices can keep sweeping requirments to minimum.
Based on cost of Dust Control Oil application as reported by State [13] and supplier [14].
-------
3.0 FORMULATION OF REASONABLE CONTROL STRATEGY ,
This chapter discusses the selection and evaluation of a reasonable
control strategy for reducing suspended particulate levels in the Phoenix
area. Since the objective of the strategy is attainment of primary air
quality standards for TSP, the strategy selection necessarily involves
an iterative process where the impact of trial strategies are evaluat-
ed successively until the desired result is obtained.
Section 3.1 describes general factors affecting the selection of
reasonable control measures. Based on the general characterization of
alternative controls described in Section 2.0, and the general considera-
tions of Section 3.1, specific reasonable measures are selected to formu-
late an overall strategy (section 3.2). For each selected measure, the
reduction in emissions of fugitive dust is estimated (Section 3.3) and
the air quality impacts of these reductions are calculated (Section 3.4)
using the source-receptor model developed earlier in the study [17].
The cost and implementation problems associated with the strategy are
also evaluated (Section 3.5 and 3.6).
A special feature of the control strategy includes a demonstration
model to promote social acceptance for the main strategy. This concept
is appropriate because of the significant funding required for implementa-
tion of the strategy, and the probable social resistance to be encountered,
Section 3.7 describes the features of this demonstration strategy.
3.1 FACTORS AFFECTING SELECTION OF REASONABLE CONTROL MEASURES
Reasonable control measures are defined as those which are techni-
cally and economically feasible to implement, and attain significant
benefits in air quality. The technological and economic feasibility
of various controls will differ depending on several factors indiginous
to the study area. General factors affecting the reasonableness of a
control measure in Phoenix include:
The compatibility of the controls with general plans
of the area
The time-table for implementation
The degree of control required
.3-1
-------
The financing mechanisms available for implementation
The extent to which proposed control measures are compatible .with
planned development affects the cost and technological feasibility of
the measure. For example, the paving of roads for dust control is en-
tirely compatible with long term city development objectives to improve
the transportation network. Similarly, the improvement of road shoulders
to reduce street dust loadings and .reentrainment of this dust to the
ambient air is completely consistent with city objectives to improve
the quality of life in the city. This compatibility lends to greater
general technical and economic feasibility for the dust control measures
because of the other desirable benefits they provide.
A significant degree of fugitive dust control will occur in the
next several years due to normal development and improvement patterns.
Table 3-1 shows the expected improvement in air quality due to antici-
pated development in the Phoenix study area. This development will
change the distribution of emission sources, eliminate local sources near
the monitors, and diminish the magnitude of many sources. Although
total dust emissions from unpaved roads are expected to increase slightly
from 1975 to 1985, the distribution of these emissions changes sub-
stantially, such that they are more widely spread in the rural areas,
and greatly reduced in the city area. By 1985, wind erosion emissions
are estimated to decrease greatly from 1975 baseyear estimates due to a
decrease in wind erosion sources (i.e., vacant property), and the probable
occurance of typical meteorology (based on historical averages in 1985.
Contributions to TSP from entrainment of street dust are expected to in-
crease slightly by 1985, especially at monitors located within the city
areas. As a result of the net changes in emission source magnitudes and (
distribution, TSP levels will decrease significantly at 11 of the 13
monitoring sites under consideration (Table 3-1).
Another consideration in the determination of reasonable measures
involves the degree of control which is sought. The ultimate goal of
the reasonable control strategy would be achievement of the primary
air quality standards. Generally, the annual mean for TSP provides the
most appropriate target for air quality attainment. Table 3-2 summarizes
the extent to which air quality standards were violated in the Phoenix
3-2
-------
TABLE 3-1. IMPROVEMENT IN TSP LEVELS DUE TO ANTICIPATED DEVELOPMENT IN THE PHOENIX AREA
MONITOR SITE
C. Phoenix
S. Phoenix
Arizona St.
Glendale
N. Phoenix
N. Scott/Paradise
Scottsdale
Mesa
Downtown
St. Johns
Sun City
Paradise Valley
Chandler
TSP, pg/m3
Observed Forecast
1975 1980
112
144
169
101
121
149
115
117
200
145
88
184
119
104
139
157
84
111
111
105
114
186
151
81
152
139
Forecast
1985
87
101
132
65
83
101.
93
95
155
157
74
93
160
Percentage
Reduction in
TSP
1975 to 1985
22.3
29.8
21.9
35.6
30.4
32.2
19.1
18.8
22.5
-8.3
15.9
49.4
-34.5
Contribution to TSP, yg/m
Unpaved Roads Resuspension Construction
1975 ' 1985 1975 1985 1975 1985
25
75
35
30
26
24
27
32
42
93
15
42
64
8
32
12
9
8
32
10
13
15
116
6
14
91
31
20
59
17
' 28
8
33
35
70
2
12
14
"10
37
2fl.
68
20
32
9
42
45
82
0
17
17
12
4
2
7
7
7
14
6 .
8
8
2
3
17
7
5
9
9
2
7.
25
5
4
10
16
25
23
Percentage of TSP Contributed
by 3 major souKces and back-
ground (30ug/m )
1975 1985
80
88
78
83
75
51
83
90
75
66
68
56
93
92
94
90
94
93
9b
94
97
89
96
93
93
97
-------
TABLE 3-2. SUMMARY OF 1973-1975 AIR QUALITY VIOLATIONS FOR
TSP IN PHOENIX AREA
Stations
Reporting
Central Phoenix
South Phoenix
Arizona State
Glendale
North Phoenix
N Scot/Paradise
Scottsdale
Mesa
Downtown
St. Johns
Sun City
Paradise Val ley
Chandler
Carefree
TSP Concentration ug/m
Annual
139
170
156
97
127
143
110
124
199
145
84
191
136
41
Expected Second
Highest 24-Hra
370
320
390
220
340
450
225
250
450
63,0
200
480
320
135
Percentage Emission Reductions
to meet primary Standards'3 based
on .linear rollback
Annual
58.7
67.8
64.1
32,8
53.6
60.1
43.7
52.1
73.3
60.8
16.6
72.0
57.5
24-Hour
32.3
20.6
36.1
--
25.8
45.2
'
45.2
61.6
--
48.8
20.6
"
aBased on statistically computed expected concentrations (from distributions
derived from historical data [23] assuming 60 measurements per year).
\ *3
Annual primary standard = 75 pg/m
24-Hour primary standard = 260 u
3-4
-------
area in 1975. Except for days of dust storms, the severity of 24 hour viola
tions were generally of lesser degree than those for the annual measurements.
Table 3-2 also shows that substantial improvements in ambient air quality
are needed before the standards may be met. The higher the level of
control which is needed for attainment, the greater are the technical
and economic demands associated with the attaining control strategy.
Another important consideration in determining what is reasonable
strategy involves the time schedule of implementation. Typically,
strategies of previous air quality programs have been predicted on meet-
ing objectives within a short term. This requirement has often imposed
implementation problems which cannot be reasonably resolved. First, the
technological problems associated with the vast resources (i.e., labor
and materials) often required for rapid implementation of a regionwide
control are generally insurmountable; second, the economic hard-
ships inherent in short term financing and the increased cost associated
with intensified program development pose important economic problems for
the short term strategy. A reasonable strategy must, therefore, permit
execution of control measures over an extended period commensurate with
the technological and economic limitations characteristic of the study
area.
The economic feasibility of any control alternative is greatly
affected by the extent and manner of funding available. Budgets re-
quired for implementation of different controls should be compared and
expressed in terms of monetary impact on a per capita or consumer basis.
The source and ease of funding should be identified and evaluated. Some
controls (such as street sweeping, road surfacing) will be funded by
taxes or other governmental money-raising mechanisms, while others
will be paid by commercial enterprises and then passed onto the private
consumer. Either method of financing is reasonable, provided the re-
quired resources are available and judged to be within the reasonable
range of cost incurred by other existing and pollution controls of
similar effect.
Generally, public acceptance of reasonable available controls is impor-
tant for implementation. It is clear that the lack of social acceptance
will impose significant obstacles to the implementation of a reasonable
3-5
-------
control, and specific measures will be necessary to overcome these obstacles.
A demonstration project may be used to generate public support when necessary.
The elements of the demonstration project, and its implications for resolving
implementation difficulties, are considered in Section 3.7.
There are no absolute guidelines for the selection of reasonable
available control technology. A measure which is reasonable in one
area may be unreasonable in another. However, in general, most of the
measures available for control of fugitive dust are reasonable. Selection,
therefore, should be based on the most cost effective measures which will
provide air quality improvements needed for standards attainment. For
example, it may be necessary to pave all roads to bring about attainment,
with any lesser.measure being inadequate for attainment. Hence, while
other-measures may be more technically and economically feasible (i.e.,
more reasonable), they would not be selected when another reasonable al-
ternative capable of attaining the needed emission reductions is avail-
able.
Once a list of reasonable candidate measures have been identified,
selection of a control strategy is an iterative process accomplished by
means of successive tests of alternatives using the source receptor model
[17] to predict resulting air quality levels. As various trial alter-
native strategies are tested, it becomes clear which areas in the study
region may need special attention and which areas will require only
minimal controls. The emissions density grid map (Figure 3-3) may be
used as an aid in identifying specific problem areas and in formulating
preliminary control strategies for test by the source receptor model.
Eventually, through a series of iterative trial judgements, a strategy
should be established which attains the air quality objective at each
of the monitor sites utilizing the most cost effective combination of
reasonable control measures available.
3-6
-------
3.2 SELECTION OF RESONABLE STRATEGY
Based on consideration of the selection factors discussed above
(Section 3.1) and the control characterization presented previously
(Section 2.0), trial strategies are formulated and evaluated in an
iterative approach to attain the air quality objectives. Table 3-3
presents the final reasonable control strategy selected to meet the
objectives.
The measures comprising the strategy reflect the most cost effective
measures, are compatible with the long term planning goals for the
region, and are also effective as substantial dust controls. The strategy
is reasonable in that it is implementable in a technical and economic
sense, and accomplishes significant improvements in air quality. How-
ever, substantial social resistance is likely to develop against its
execution. A special feature of the overall strategy is a demonstration
project to develop social acceptance for the areawide strategy approach.
This portion of the strategy is discussed in Section 3.7.
The reasonable control strategy is selective for the three major
sources affecting air quality. Table 3-2 illustrates the relative
effect of these three sources on anticipated baseline TSP levels and
demonstrates clearly the justification for focusing attention to these
sources. In 1975, unpaved roads contributed the greatest portion of
TSP levels at most of the monitor sites. By 1985, after anticipated
development, TSP levels at the monitors are affected mostly by en-
trained dust off streets. Unpaved road emissions are still a dominant
contribution of TSP levels at sites in or near rural environments
(e.g., St. Johns, South Phoenix, North Scottsdale/Paradise, and
Chandler).
It is important to distinguish between the controls needed to
attain the standard throughout the region and that needed to attain the
standards only at the monitoring stations. Because of the very localized
impact of fugitive dust sources, it is possible to attain localized attain-
ment by application of controls in limited areas, (i.e., around
" 3-7
-------
TABLE 3-3. REASONABLE CONTROL STRATEGY FOR PHOENIX AREA*
SOURCE CATEGORY
PROPOSED CONTROL MEASURES
1. Unpaved Roads
Entrained Dust off
Paved City Streets
3.
Construction
Activities
4. Other Sources
County Roads
Chip seal all section line roads with emulsified asphalt
by 1995, and one half of section line roads by 1985. Sequence
of road selection should be based on ADT volume.
Reduce speed limit to 20 mph for all unpaved roads
gradually by 1985, or, where applicable, permit improve-
ment districts to implement equivalent dust control by
surface treatments such as graveling, oiling, or paving.
Restriction sequence should be based on availability of
alternative pave'd routes and trip lengths.
Private Roads
By 1985, restrict speed to 20 mph or require equivalent
dust emissions reductions by surface treatments such
as o'ling, watering, graveling, or paving.
City Streets
t By 1980, establish a field measurement program to deter-
mine street dust'loads and effects of various street
sweeping alternatives (using broom sweepers and vacuum
sweepers) on street dust loads.
Based on results of field program, formulate sweeping
requirements and implement by 1985 a program to attain
a 60% reduction in the current assumed average street
dust loading of 780 pound per mile [8] in the designat-
ed areas (Figure 3-1).
Effective wetting of site access roads twice daily
at .5 gal/yd .
By 1980, sweep roads to remove visible dust loads caused
by construction activities. Sweeping shall be performed
whenever dust loads are apparent, to maximum frequency
of once daily.
By 1980, require stabilization of all exposed earth at
construction site whenever operations cease on that land
for over 2 months.
No additional measures are recommended for other sources.
These sources are already controlled (either by direct
pollution regulations or by other restrictions which af-
fect dust control) or have minor impact on TSP levels.
* A demonstration project is recommended as a prerequisite to
implementation of.the overall control strategy. This project
'would involve application of the strategy measures within a
limited selected area. The project should be conducted prior
to the deadline date for submittal of State Implementation
Plans -For fugitive dust control in July, 1978.
3-8
-------
monitor sites). This approach should not be used to circumvent the
widespread TSP problem in the Phoenix area. It is evident that TSP at
other locations may be equivalent or higher than that represented by
the monitor network. However, an accurate prediction of the non-attain-
ment problem at these sites is unavailable. Under the circumstances,
a plausible policy for control strategy formulation was taken as:
1) apply an area-wide plan whichiattains standards at the monitors and
improves air quality elsewhere, and 2) identify the various locations
where additional controls may be necessary, but cannot be justified un-
til air monitoring data are available to confirm high TSP levels there.
The latter task may be accomplished by inspection of the 1985 projected
emissions grid maps, (see Section 3.3).
Implementation of the overall strategy (Table 3-3) is proposed
after the demonstration project is completed. The main element of the
overall strategy consists of an intensive road surfacing program in the
county for the next 20 years. Road surfacing is to be conducted by
applying a chip seal to the section line roads. This approach represents
the most cost effective of the alternative road surfacing measures (Table
2-5), and attains maximum source control where applied. Priorities for
the paving program would be assigned in the order of those section roads
receiving greatest traffic volume, and the county of Maricopa Depart-
ment of Transportation would administer the program.
In addition to the road surfacing measure, a control is also
proposed for existing or future unpaved roads. A speed restriction for
unpaved roads is especially cost effective, and is considered reasonable
when phased in concurrently with the road surfacing measure. Exceptions
to the speed limit would be permitted in instances where '.accessibility
to alternative paved routes is unavailable (e.g., roads connecting
remote residence sites to county arterials). Also, other techniques
of dust control (e.g., watering, graveling, oiling) would be permitted
in place of the speed restriction wherever private groups desire to
assume responsibility for improvements.
3-9
-------
The overall strategy includes an intensive street cleaning program
in designated areas where reduction of entrained street dust emissions
is necessary to attain the air quality standards. Figure 3-1 shows the
two areas which receive attention under this plan: the area surrounding
downtown Phoenix and the area around downtown Scottsdale. It is proposed
major streets be swept more frequently, alternating from vacuum sweeping
to broom sweeping to attain an overall reduction of 70% in sus-
pendable street dust loadings. The broom sweeper would be used to dis-
lodge material adhering to the road and for collection of larger particles,
while the vacuum sweeper would be employed for the efficient and cost
effective collection of dust particles of all sizes. The analysis of
Section 2.0 indicates that adjustment of typical existing street sweep-
ing programs to obtain a 60% reduction in street dust loadings is probably
feasible.
Because of the limited data ba-se available to characterize street
dust loadings and sweeping efficiencies, it is not possible to specify
a definite street sweeping program to accomplish the targeted emission
reductions. A field measurement program is proposed to establish baseline
loadings for various streets and to determine by test the actual sweeping
programs needed to obtain the required dust levels. Based on the crude
data of baseline average dust loadings and street sweeping efficiencies
available (Section 2.0), it appears that an adjustment from the existing
sweeping frequency (once per week for most major streets) to 3 times
per week will produce the targeted emission reductions.
The final element comprising the control strategy entails enforce-
ment of more rigorous regulations for construction activities. The
measures are relatively cost effective in terms of total emissions re-
ductions, and produce significant benefits in air quality for those areas
affected by construction emissions. The regulations would require:
1) sweeping of nearby roads to remove visible dust loads caused by
construction activities (e.g., vehicle carryout from the construction
site), 2) wetting of site access roads (when used) twice daily, and
3) stabilization measures for land exposed without construction activity
3-10
-------
PHOENIX
AND VICINITY
Figure 3-1. Area Map showing Special Areas (Downtown Phoenix and Scottsdale)
Designated for Intensified Street Sweeping Programs
3-11
-------
for more than two months. These measures would be incorporated as
regulations of the building codes and enforced by the local Building
and Safety Department.
Evaluation of the emissions reductions and air quality resulting
from the strategy is discussed in Section 3.3 and 3.4. From this analysis
nine potential nonattainment areas are identified (see Figure 3-10). There
is a distinct likelihood that some of these areas may require special con-
trols (e.g., street sweeping in urban areas). To establish the extent
of the TSP problem in these areas, and to simulate future air quality
levels there, it is recommended that the current monitoring network be
expanded to include representation of air quality in the potential non-
attaining areas. The additional monitor sites could be included as
part of the control strategy implementation, however, it would be pre-
ferable that the.new monitors be installed prior to state submittal of
fugitive dust implementation plans (July, 1978) so that any additional
area-specific control measures which might be required'may be efficiently
integrated into the overall control plan.
The strategy proposed in Table 3-3 has resulted from a series of
trials of different control alternatives applied in varying degrees.
Road improvements have been emphasized in the overall plan because of
compatibility of this control with the general planning objectives of
local agencies, because of the substantial impact of unpaved roads on
air quality, and because dust control off unpaved roads is generally
more cost effective than other measures. By accelerating this street
improvement program (a program which would eventually be implemented
on a slower timetable), the intensive street sweeping measure is needed only in
isolated areas. Minimizing additional street cleaning requirements is
appropriate considering the low priority of this function relative to
other programs now receiving competing attention for the city of Phoenix
Department of Transportation budget, and the high cost of this measure
as a dust control. Curbing for unpaved road shoulders is an effective
measure for reducing street dust loads, but was not included in the
final control strategy because most streets in the designated vicinities
requiring attention are located in downtown areas, and are either presently
3-12
-------
curbed or will be curbed after planned improvements are carried out through
the year 1985. Dust controls for construction activities are not responsible
for major long-term gains in air quality but are included to alleviate tempo-
rary and localized high levels of TSP surrounding the construction sites.
3.3 IMPACT OF STRATEGY ON EMISSIONS LEVELS
The effect of the proposed strategy on total emissions levels for the
entire study area is shown in Table 3-4. The source most affected by the
control strategy is unpaved roads. Dust emissions from unpaved roads are
reduced by about 36% from the anticipated levels in 1985, and 22% from the
baseyear (1975) levels. The reduction in this single category amounts to
about 22% of the total 1985 baseline emissions total, and the impact of
this reduction on air quality is expected to be substantial because of the
local concentration of this source near many of the air quality monitors.
Similarly, control of entrained dust emissions off paved roads in the down-
town Phoenix area and Scottsdale will incur emissions reductions in areas
near monitor sites in these locations. However, total entrained dust emissions
in the study area are expected to be reduced only 5.6% from 1985 baseyear
emission forecasts. Construction emissions will be reduced by 30% of the
1985 baseyear construction emissions totals, however, this reduction amounts
to only 3% of the total baseline emissions forecast in 1985. Hence, con-
struction dust controls are expected, to alleviate localized short term TSP
levels, but exert only minor effect on monitor annual TSP levels. Due to
planned development in the study area, remaining fugitive dust sources not
addressed by the strategy are reduced below 1975 levels by a greater degree than
those major source categories which are the object of the control strategy.
Overall, the total change in emission levels, due both to the control strategy
and to anticipated development in the study area, amounts to a reduction of 23%
from the 1975 to 1985 forecasted level.
Equally important as the emission level reduction magnitudes are the
distribution of these reductions. Figure 3-2 presents the level and spatial
distribution of emissions before and after strategy application. It is clear
that with strategy, emissions are reduced substantially in the area near the
monitor sites, that is, primarily in and bordering the metropolitan Phoenix
3-13
-------
TABLE 3-4. IMPACT OF CONTROL STRATEGY
ON TOTAL EMISSION LEVELS
Source Category
Unpaved Roads
Entrained Street Dust
Construction Activities
Wind Erosion-Undisturbed Desert
Off-Road Vehicles
Other Categories
Total Emissions
Baseyear
Emissions
(1975)
1281
246
100
294
71
366
2360
Baseline Pro-
jected Emissions
(1985)
1553
322
256
85
106
139
2462
TOTAL EMISSIONS IN STUDY
Emissions After Ap-
plication of Control
Strategy - 1985
999
304
179
85
106
. 139
1812
AREA, TONS/DAY
Percentage Reduction
from Baseyear (1975)
in 1985
22.0
22.6
-79.0
71;0
.-49.3
62.1
23.2
Percentage Reduction
from 1985 Baseline
35.7
5.6
30.0
0.0
0.0
0.0
26.4
GO
I
-------
BASELINE 1985
AFTER STRATEGY, 1985
Tigure 3-2. Total Partlculate Emissions For Phoenix Study Area 1n 1985.
With and Without Control Strategy.
-------
GRID
CODE
0
1
2
3
4
5
6
7
8
9
EMISSIONS
TONS/DAY
0
0 to .01
.01 to .04
.04 to .13
.13 to .32
.32 to .67
.67 to 1.2
1.2 to 2.1
2.1 to 3.4
3.4 to 5.2
Figure 3-3. Total Particulate Emissions in 1985
After Application of Control Strategy.
3-16
-------
GRID
CODE
0
1
2
3
4
5
6
7
EMISSIONS
TONS/DAY
0
0 to .01
.01 to .04
.04 to .13
.13 to .32
.32 to .67
.67 to 1.2
1.2 to 2.1
2.1 to 3.4
3.4 to 5.2
Figure 3-3.
(continued)
Particulate
Baseline Total
Emissions in 1985.
3-17
-------
region. The location of these reductions are consistent with the intent
of the control measures comprising the strategy. Entrainment of street dust
is prevented by control programs within the designated cities, and roads are
paved by priority of vehicle count along section lines closely surrounding
the metropolitan area. Figure 3-3 provides a more detailed illustration of
the distribution of emission densities in the study area: emission levels for
each of the grid squares of the study area network are given for both the
baseline and strategy forecasts. Because the major portion of ambient TSP
levels are caused by the local sources in the immediate vicinity of the
receptor, the emissions grid map of Figure 3-3 serves as a general representa-
tion of the TSP distributions as well. However, caution should be employed in
this representation, since local effects within a grid square may also cause
unsuspected levels of TSP to occur when the receptor is near or in the plume
of a nearby source. For example, sources at St. Johns may be very area-
specific with respect to TSP values measured there because of the concentration
of fugitive dust sources near the monitor. The grid emissions map of Figure
3-3 would not indicate this potential local effect, and assigns, instead a
lower emissions density based on the distribution of the "hot spot" sources
over the entire grid square.
The impact of the strategy on each of the major source categories and
the basis for these estimates is discussed in the following sections.
3.3.1 Unpaved Roads
The selected control strategy for unpaved roads is consistent with the
County's long-range planning objectives. Under the County's planned develop-
ment, the number of unpaved interior streets will decrease steadily as road
improvements are accomplished according to County priorities. Priority for
paving of roads is presently determined mainly by ADT. Table 3-5 shows the
projected ADT for various road types in the study area for 1985. By 1985,
baseline traffic volumes of unpaved roads is expected to increase by 50%.
At the same time, the total mileage of unpaved gravel roads is expected to
decrease by 21% (Table 3-6). Gravel roads are the principal target for
present planned improvements, since they receive the heaviest traffic activity.
Most of these roads are section line streets (1 mile apart) which serve as
3-18
-------
TABLE 3-5. TRAFFIC ACTIVITY AND STATUS OF UNPAVED ROADS IN STUDY
AREA, 1975 AND 1985
Dirt Roads (Maintained)
Dirt Roads (Not Maintained)
Gravel Roads
AVERAGE DAILY TRAFFIC
Rural
1975 1985
40 60
11 16
60 90
Urban
1975 1985
75 112
15 22
100 150
1. Figures are based on data presented in Support Document #2.
TABLE 3-6. UNPAVED ROADS MILEAGES IN STUDY AREA, 1975 AND 1985
Portion of Maricopa
County
Cities in Maricopa
Portion of Pinal
County
TOTAL
1975
Gravel
720
71
163
954
Dirt-
Maintained
1100
106
307
1513
Dirt-Not
Maintained
570
598
1168
1985
Gravel
579
10
163
752
Dirt-
Maintained
886
15
307
1208
Dirt-Not
Maintained
453
598
1051
3-19
-------
major traffic links throughout the country. The net results of the planned
improvements and the expected traffic volume increases is an overall increase
in unpaved road emissions from 1281 tons/day in 1975 to 1553 tons/day in
1985 (Table 3-4).
With implementation of the proposed Control Strategy, dust emissions
from unpaved roads are reduced substantially. Due to road, surfacing of
one-half the unpaved section line roads, previously anticipated 1985 emissions
arising from one-half the unpaved gravel roads in Maricopa County are es-
sentially eliminated. The road surfacing measure alone may account for a
reduction of nearly 50% of the estimated baseline emissions in this source
category, depending on the absorption of traffic from the remaining unpaved
roads to the newly improved alternates. Transportation of traffic to newly
paved streets will be further hastened by the traffic speed control measure
of the unpaved roads strategy. Vehicle speed on unpaved roads will be
restricted to 20 mph, causing an estimated dust emissions reduction of
approximately 40% (assuming vehicles will actually travel at 25 mph) for
those vehicles still using these roads. A significant portion of traffic
would be expected to switch to the newly paved roads.
In order to predict the reduction in VMT unpaved county roads as a
result of paving the gravel section line roads, a representative one-mile
rural section of the traffic line network was constructed, and net travel
in the link was considered for the "before and after" road paving control.
The representative .section was constructed using a street map. The map
showed that roughly 65% of the section line roads in Maricopa County are
presently paved. Travel on unpaved and paved lengths within the section to
alternative exit points on the section boundary was estimated by assigning
a through trip to the vehicle population expected to reside in the section.
the analysis showed that the paving control would reduce expected traffic on
remaining interior unpaved roads by 15% in 1985.
Because the strategy includes the paving of all roads within the cities,
dust emissions from unpaved city roads are essentially eliminated. For most
cities, this involves a modest street improvement program. For the City
of Phoenix, no additional strategy is required since the present 10-year
program includes improvement of all existing unpaved streets. (New unpaved
roads are not anticipated due to a county ordinance which requires paving
of all newly developed roads.)
-------
The expected emissions reductions associated with the control measures
are applied to the computerized baseline inventory on a grid square basis to
determine the emissions levels after controls are applied. The computerized
inventory maintains a record of urban and rural road types, mileages, and
dirt road silt values for each grid square of the study network. Table
3-4 summarizes the effect of the dust control strategies on total unpaved
road emissions for the study area. Over the 10-year period from 1975 to
1985, total dust emissions from unpaved roads would diminish 22% from 1281
tons/day in 1975 to 999 -jn 1985. The distribution of emissions, both for
the baseline case and with strategy applied, is shown in the graphics
plots and emission grid maps of Figures 3-4 and 3-5. It is clear that emis-
sions from unpaved roads diminish appreciable from 1985 baseline levels in
the vicinity of .nearly all the monitor sites.
3.3.2 Entrainment of Dust Off Paved Roads
The selected dust control strategy for entrained street dust on city
roads is consistent with city planning goals to maintain clean streets. An
effective street cleaning program is needed to maintain acceptable aesthetic
standards, to reduce pollution to sewer waters and treatment requirements
at sewage plants, and to maintain the condition of road surface. Dust con-
trol is an additional benefit to be gained by road cleaning programs, and
generally requires more effort than normally expended in typical street
cleaning operations. Accordingly, the proposed control strategy for street
dust consists of an intensification of the city street cleaning progams in
two designated areas where entrained street dust must be controlled for
attainment of the standards.
The dust control benefits that can be achieved with various street
sweeping operations was discussed in Section 2.2. It was determined that
either broom sweepers or vacuum sweepers may be employed to reduce total
street dust loadings significantly when the level of street cleaning
effort is increased greatly over the normal amount. However, it was also
determined that broom sweepers were far less efficient than vacuum sweepers,
especially for removal of smaller particles in the suspendable size range.
In fact, broom sweepers tend not to remove the smaller particles, but to
3-21
-------
BASELINE, 1985
AFTER STRATEGY, 1985
Figure 3-4. Total Particulate Emissions From Unpaved Roads, With and
Without Strategy, 1985
3-22
-------
GRID
CODE
0
1
2
3
4
5
6
7
8
9
EMISSIONS
TONS/DAY
0 to 0
0 to 005
0 to .02
.02 to .07
.07 to .18
.18 to .37
.37 to .68
.68 to 1.2
1.2 to 1.9
1.9 to 2.8
Figure 3-5. Total Particulate Emissions from Unpaved Roads
in 1985 After Application.of Control Strategy.
3-23
-------
GRID
CODE
G
1
2
3
4
5
6
7
8
9
EMISSIONS
TONS/DAY
0 to 0
0 to 005
0 to .02
.02 to .07
.07 to .18
.18 to .37
.37 to .68
.68 to 1.2
1.2 to 1.9
1.9 to 2.8
Figure 3-5. (continued) Total Particulate Emissions
From Unpaved Roads, Baseline 1985.
3-24
-------
redistribute them instead. Consequently, the different effect of each of
the sweeper types on dust emission rates off paved roads is appreciable
(see Table 2-12).
While the vacuum sweeper attains higher collection efficiency for
loose dust loadings under dry conditions, it is not as effective as the
broom sweeper for collection of heavy, wet loadings which typically occur
after rainstorms. In addition, rainstorms tend to distribute dust loadings
across the entire street surface (as opposed to the usual high density of
dust found only near the curb), making the broom sweeper, with its wide sweep
span, a very appropriate dust collection mechanism under these conditions.
The City Maintenance Department has suggested that optimal street cleaning
equipment might consist of a battery of both vacuum sweepers and broom
sweepers, to be used alternately depending on street loading conditions [11].
Because rains occur infrequently in the Phoenix area, it is feasible that
the future expanded sweeper squadron should be comprised predominantly of
vacuum sweeper types. As one feasible street cleaning scenario, broom
sweepers would be employed at the same frequency as in the baseyear, while
vacuum sweepers would be used for street cleaning twice in the interim
period. Based on Figure 2-9 and data presented in Section 2.2, this
alternating sequence between broom sweepers and vacuum sweepers would attain
at least a 60% reduction in entrained street dust emissions off city
streets. This sweeping scenario is suggested as a tentative estimate of
the sweeping program which may be applied to the designated areas (Figure
3-1) which appears to require additional sweeping effort.
Because of the limited data base available to characterize street dust
loadings and the effect of different sweeping alternatives, final selection
of the sweeping measures of the control strategy should be deferred until
an area-specific field measurement program is conducted. This program would
establish baseline loadings for various streets and determine by test the
actual sweeping programs needed to reduce entrained street dust emissions to
allowable levels. The measurements would include an analysis of dust silt
levels resulting from use of the major sweeper types to enable a fair assess-
ment of the efficiency of the sweepers in removing not only total dust loads,
but in particular the suspendable fines.
3-25
-------
If reconciled to field test data, the proposed street sweeping scenario
would reduce total street dust by about 60% in the designated areas targeted
for control. This reduction estimate was applied to all streets within the
designated control areas (Figure 3-1). Total entrained dust emissions were
calculated for each link and assigned to grid squares of the study area grid
network by means of simulator software operating on a computer tape of 1975
transportation link data. The variation in emissions density throughout the
study area, with and without the strategy in 1985, is illustrated by the
graphics of Figure 3-6 and the grid map of Figure 3-7.
3.3.3 Construction Activities
The wetting of construction access roads twice daily is assumed to
account for a 30% reduction in construction emissions (see Section 2.3).
This reduction was applied throughout the study area to the 1985 baseline
projected construction emission inventory. Additional measures, such as
nearby road sweeping and soil stabilization will further reduce construction
emissions by an undetermined amount. "Figure 3-8 and 3-9 show the distribution
and magnitude of emissions expected from construction activities after the
control strategy is applied by 1985.
3.4 IMPACT ON AIR QUALITY
The emission levels associated with the proposed reasonable control
strategy were translated into air quality forecasts using the source-receptor
model developed earlier in the study. These forecasts are shown for each of
the monitoring locations in the study area in Table 3-7. Substantial improve-
ments in air quality occur at each monitoring site. Baseline TSP levels in
1985 are reduced by about one third at most sites, and some monitor sites
experience from 40 to 60% reductions in TSP levels. In many cases, a signifi-
cant portion of the air quality gains over baseyear levels is due to baseline
development planned for the area (see Section 3.1). Between the improvements
achieved by development and the strategy together, baseyear TSP levels are
reduced by 31 to 76% by 1985.
3-26
-------
BASELINE, 1985
AFTER STRATEGY, 1985
Paved Streets, With and
3-27
-------
GRID
CODE
0
1
2
3
4
5
6
7
8
9
EMISSIONS
TONS/DAY
0 to 0
C to .004
.004 to .02
.02 to .07
.07 to .18
.18 to .37
.37 to .69
.69 to 1.2
1.2 to 1.9
1.9 to 2.9
Figure 3-7. Total Dust Emissions (Entrained from Unpaved Roads
In 1985 After Application of Control Strategy.
3-28
-------
GRID
CODE
EMISSIONS
TONS/DAY
0 to 0
0 to .004
.004 to .lit
.02 to .07
.07 to .18
.18 to .37
.37 to .69
.69 to 1.2
1.2 to 1.9
1.9 to 2.9
Figure 3-7. (continued) Total Dust Emissions From Paved Roads,
Baseline 1985.
3-29
-------
OJ
I
CO
o
WITH STRATEGY, 1985
Figure 3-8. Total Dust Emissions
From Construction Activities in 1985 After Application of Control Strategy
-------
GRID
CODE
0
1
2
3
4
5
6
7
8
9
EMISSIONS
TONS/DAY
0 to 0
0 to .001
.001 to .007
.007 to .02
.02 to .06
.06 to .12
.12 to .22
.22 to .38
.38 to .61
.61 to .92
Figure 3-9. Total Dust Emissions From Construction Activities in 1985
After Application of Control Strategy.
3-31
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TABLE 3-7. IMPACT OF CONTROL OF MAJOR SOURCE CATEGORIES ON TSP LEVELS
CO
I
CO
ro
MONITOR SITE
1. Central Phoenix
2. S. Piioenix
3. Arizona State
4. Glendale
5. N. Phoenix
6. N.Scottsdale/
Paradise
7. Scottsdale
8. Mesa
9. Downtown Phoenix
id. Sun City
11. Paradise Valley
12. Chandler
13. -St. John
TOTAL SUSPENDED PARTICUL/VTES, ug/m3
BASELINE
1975 1980 1985
112 104 87
144 139 101
169 157 132
101 84 65
121 111 83
149 111 101
115 105 93
117 114 95
200 186 155
88 81 74
184 152 93
119 139 160
145 151 157
STRATEGY
1980 1985
99 77
12£ 73
138 73
80 56
104 73
105 78
99 73
105 74
163 85
79 64
138 73
113 68
130 85
REDUCTION OF:
1975 TSP DUE '
1985 BASELINE TO STRATEGY &
TSP DUE TO PROJECTED
STRATEGY DEVELOPMENT
11.4% 31.22;
27.7% 49.3%
44.6% 56.8%
13.8% 44.6%
12. IS 39.6%
22.8% 47.6%
21.5* 36.5%
22.1% 36.7%
45.1% 57.5%
32.4% 76.1%
21.5% 60.3%
57.5% 42.8%
45.8% 41.4%
CONTRIBUTION TO TOTAL SUSPENDED PARTICULATES , ug/m3
UNPAVED ROADS ENTRAINED ST. DUST CONSTRUCTION ACTIVITIES
1985 1985 1985 1985 1985 1985
BASELINE STRATEGY BASELINE STRATEGY BASELINE STRATEGY
8 1 37 35 55
32 7 24 23 96
12 2 68 24 96
9 1 20 20 21
8 1 32 32 75
32 16 99 25 18
10 2 42 33 54
13 3 45 45 43
15 2 82 29 10 7
6 1 17 17 16 11
14 2 17 16 25 17
91 5 12 12 23 16
116 45 2 2 22
BACKGROUND
LEVEL
30
30
30
30
30
30
30
30
30
30
30
30
30
-------
With application of the control strategy, air quality at all thirteen
of the monitor sites is forecasted to attain, or come very close to attaining,
the primary air quality standard for TSP (75 yg/m ). Only the Downtown
O
Phoenix and St. John sites are expected to experience TSP levels (85 yg/m )
significantly higher than the standard. However, previous analysis has shown
that air quality at each of these sites is probably not representative of
air quality in the general area. Each of the two sites is located in a
hot spot of fugitive dust sources, and air quality measured there is site-
specific and biased towards higher levels than are 'representative of the general
area. Consequently, additional site-specific control measures may be needed.
However, before these measures are implemented, it may be advisable to further
examine the existing air monitoring network in the areas in question and supple-
ment the network as necessary to further refine the problem and evaluate the
impact of the proposed strategy once it is implemented.
Control strategy air quality improvements are dominated primarily by
reductions of dust emissions from unpaved roads. Because controls for unpaved
roads are targeted for county areas,monitor sites outside the metropolitan
influence tend to be more affected by the control measures proposed for un-
paved road emissions. These measures improve TSP levels at Chandler, St.
Johns, North Scottsdale/Paradise Valley, and South Phoenix in amounts ranging
from 25 to 71 yg/m in 1985. The effect of controls to reduce entrained
street dust emissions off paved roads is evidenced most noticeably at monitors
within the designated areas of control (Downtown Phoenix and Scottsdale). The
downtown Phoenix monitor experiences the greatest improvement as TSP levels
3
are reduced by 53 yg/m due to the street dust strategy measures. The effect
of construction controls is relatively minor at all monitors, ranging from a
o
resulting improvement of 8 yg/m at Paradise Valley to no improvement at St.
Johns where construction activities are anticipated to be very limited. As
discussed previously, other sources do not contribute significantly to TSP
levels at the various monitor sites.
As anticipated, the areawide emission reductions are significantly less
than the relative improvement in air quality. A 36% emission reduction
(Table 3-4) occuring in 1985 from the strategy translated to TSP reductions
of 11 to 57%. In view of the relatively high background contributions,
which is unaltered by the strategy, the improvement leverage provided by the
emissions reductions is appreciable. As discussed previously, this is due to
3-33
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the dominant influence of local fugitive sources on TSP levels at any
given location.
The impact of the control strategy by 1980 is also significant, but
because the control measures are about only two-sevenths complete by
this time, air quality at only one of the monitor sites (Sun City) is fore-
casted to attain the primary standard.
i
As discussed earlier, it is useful to distinguish between the control
strategy needed to attain the standard throughout the region and that
needed to attain the standard at the monitoring stations. Because of the
very localized influence of fugitive dust sources, and the limitations
associated with current state-of-art air quality simulator techniques, the
proposed control strategy cannot assure region-wide attainment. TSP levels
at certain locations may be higher than those represented by the monitoring
network. The analysis of air quality and emissions levels resulting from
the strategy may be combined to indicate potential non-attainment areas
where monitor sites should be established and additional controls applied
if warranted. Figure 3-10 shows nine potential non-attainment areas which
may require additional control attention in 1985. These areas were identified
by locating grid squares where emissions densities were greater than those
levels predicted at the attaining monitor sites (i.e., all grid squares with
grid codes greater than 7). Inspection of the emissions grid maps (Section
3.3) suggests the relative influence of the major sources on air quality at
these sites. Some of the potential hot spot grid squares are located within
the metropolitan area and are most affected by entrained street dust emissions.
Most of the potential problem sites are located in more rural areas outside
the metropolitan influence, where unpaved road emissions and dust from con-
struction activities are the major sources of the emissions totals.
Air quality monitors should be installed at the indicated sites to
establish baseline TSP levels for use in air quality simulation and prediction
of future TSP levels there. The timetable for completing the expanded monitor
network should be immediate to permit appropriate adjustment of the proposed
control strategy.
3-34
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43533
GRID
CODE
0
1
2
3
4
5
6
7
8
9
EMISSIONS
TONS/DAY
0
0 to .01
.01 to .04
.04 to .13
.13 to .32
.32 to .67
.67 to 1.2
1.2 to 2.1
2.1 to 3.4
3.4 to 5.2
Figure 3-10.
Potential Non-Attainment Are*
in 1985 After Application o*
Proposed Control Strategy.
3-35
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3.5 COST OF CONTROLS
The cost of implementing the control measures of the proposed strategy
are shown in Table 3-8. The estimates are based on cost data presented in
Section 2. The cost effectiveness is expressed in terms of emissions re-
ductions and average air quality improvement. With the exception of the
measures to restrict vehicle speed on unpaved roads, there is relatively
minor difference in the cost effectiveness of the various measures. The
vehicle speed restriction is especially cost effective because of 1) the
substantial emission reduction attained, 2) the presumption that the
measure can be implemented inexpensively at an annualized cost of $200,000.
Costs of the measures vary from about $2 to $55 per ton of dust emissions
prevented, or from about $40,000 to $218,000 for each yg/m of TSP con-
centration decrease. These costs are significantly loWer than those
typically required to control particulate emission sources in other regions
experiencing non attainment problems due mainly to conventional type
sources [21].
The total cost of instituting the control strategy is consistent with
the concept of "reasonable" strategy defined earlier. Annual cost of the
strategy is about $4.4 million, or approximately $3 per capita in Maricopa
County. This compares to an appropriate 1976 total budget of $358 million
for the city of Phoenix. Expressed as a tax on automobile gasoline in
Maricopa County, the control would cause an increase of 0.8 cents per gallon.
An important aspect in assessing the true cost of the controls concerns
cost benefits derived from the measures. The cost effects of air pollution
on water treatment, materials, aesthetics, property taxes, vegetation,
health, and economic development are significant. It is recommended that
the demonstration model, proposed as an integral part of the overall control
strategy (see Section 3.7), include a cost benefit analysis for each of the
proposed measures.
3-36
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TABLE 3-8. COST OF IMPLEMENTING CONTROL STRATEGY
CO
I
00
SOURCE CATEGORY
Unpaved Roads 1 .
2.
Entrained Dus.t 1 .
Construction
Activities 1 .
2.
3.
1
TOTAL, OVERALL STRATEGY
ANNUALI7.ED COST INCREASE
(MILLIONS OF DOLLARS)
CONTROL MEASURES
Chip seal all section line roads by 1995, and one- 2.5
half by 1985.
Reduce speed limit to 20 mph for all interior unpaved .2
roads (private and county) gradually by 1985.
/ e
By 1985, sweep major roads in designated areas to attain .36
a 60" reduction in the current assumed average street
dust loading. Based on the existing data base, the
sweeping program would consist of cleaning major roads
three days weekly, alternating from vacuum sweeping to
broom sweeping as appropriate.
Effective 1980, wetting of site access roads twice daily at
.5 gal/yard.2 .72a'
By 1980, sweeping of paved roads used by construction vehicles .60
to remove visible dust resulting from construction activities.
By 1980, stabilization of exposed earth at construction sites - c'
when operations cease.
4.4
COST EFFECTIVENESS
S/TONS OF EMISSION
PREVENTED
23.0d"
2.1d'
54.8
25.4
18.6
a.
b.
c.
d.
e.
f.
Based on assumption that access roads comprise 10% of all areas.involved in construction activity (6590 active acres/month), and
watering of these roads is currently performed once daily at $3/acre.
Based on assumption an average construction site is comprised of a 2 acre plot and there are some 330 individual sites which must
be attended on any day in 1985.
It is anticipated that construction practices will be modified to avoid this control requirement by suitable scheduling of
activities.
Based on emissions reduction of 298 tons/day due to paving measure, and 256 tons/day due to speed limit restriction.
This estimate was derived by multiplying the current average cost of street cleaning in Phoenix ($4.80/curb mile [15]) by the
number of curb miles of major roads to be swept 3 times weekly in the designated areas. (Total of 474 curb miles based
on compilations from traffic volume maps).
Cost effectiveness in terms of incremental air quality improvement was computed by dividing the total annual cost of the
measure by the average incremental TSP improvement for all monitor sites. Accordingly, this figure reflects the particular
cost effectiveness associated with gains at the monitor sites only.
-------
3.6 IMPLEMENTATION PROBLEMS
The difficulty in implementing the strategy depends on political,
legal, and socioeconomic obstacles associated with the various control
measures. The magnitude of these obstacles depends on the general im-
plementation approach of the strategy, that is, whether it is to be en-
forced as a series of air pollution control regulations, or as in-line
actions to be taken by various agencies in the performance of related
projects. As a direct regulatory approach, implementation of the strategy
will probably meet with substantial obstacles. There is the legal question
of whether the county has the authority to regulate and impose require-
ments on various agencies or private interests, and whether legislation
has actually delegated this specific authority to the county. While local.
agencies are responsible for the establishment of air pollution regulations,
the justification for many local regulations has stemmed from state and
federal pollution control requirements. The county could exercise initiative
in assuming implied-authority, and adopt new regulations for implementing
the control strategy, but the risks involved in this approach (e.g., jeopardy
of the current control program) would make it an improbable action by the
county.
In addition to legal obstacles, political and social acceptance of
the proposed measures may pose implementation problems especially if
controls are imposed by regulations. Regulations assembled by the County
Health Department and justified on the basis of air quality improvements
may generate apprehension on the part of agencies and individuals per-
ceiving conflict with their own interests. Productive interaction among
appropriate groups would alleviate this problem, but visible enforcement
of the measures by an air pollution control agency for questionable health
benefits would place support for the strategy in constant jeopardy.
The alternative to the regulatory approach for control measures is a
workable approach which provides for integration (when possible) of the
control measures into the on-line operations of various governmental agencies.
This approach generates greater political and social acceptance to the measures,
since the measures are visible not only as dust controls, but as planning and
3-38
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development improvements which will yield several tangible benefits of
more popular demand. In view of the types of major fugitive dust emission
sources which are typically uncontrolled at present, the integral planning
approach is particularly appropriate. Reasonably available controls for
unpaved road dust and entrained street dust emissions are entirely con-
sistent with objectives of the local transportation and street maintenance
departments.
The major obstacle confronting implementation of a dust control strategy,
whether utilizing the integral planning approach or the direct regulatory
technique, concerns the socioeconomic acceptability of the proposed actions.
Appropriations by the respective local agencies for implementing controls
requires financial support of the citizenry, whether by taxes, bonds, or
assessment districts. While the funding needed to support implementation
of the strategy is relatively miminal (amounting to 1.2% of the annual city
budget), there is little chance that the additional expenditures associated,
with the strategy would be absorbed in the annual budgets without visible
justification. Such justification may be facilitated by a persuasive
control demonstration project to validate the benefits of the proposed
strategy.
While some of the major sources can be controlled with general plan-
ning programs within the relevant local agencies, it is clear that all
sources cannot be controlled in this manner. For example, commercial
point sources of fugitive dust are currently controlled by county regula-
tions under the reasonable control clause requirement, and although other
participating agencies (e.g., Building and Safety Department) may be in-
volved in implementation of the present rule, the motivation stems from
regulatory mandate rather than planning interest. Such regulatory mandates
are subject to test by the courts. In fact, the reasonable control clause,
as it applies to construction activities, has already been tested in Phoenix.
The state court ruled for the regulation in this case, deciding that a
contractor has not taken reasonable precaution to reduce dust emissions
during construction activities. The proposed strategy of this study would
expand the control regulation for construction activities (requiring watering
twice daily and daily street sweeping) in more specific terms,and enlist
3-39
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the participation of the Building and Safety Department in the issuing of
construction permit approvals (under their delegated authority) contigent
on compliance with the control measure.
Table 3-9 provides a summary of the ranking of implementation dif-
ficulties anticipated for each of the control measures comprising the
strategy. The rankings are based on the interdisciplinary implementation
approach, in which various departments of the local government are active
participants in carrying out the strategy. The assessment is estimated
for two cases: with, and without the benefit of a demonstration model pre-
ceeding implementation of the area wide proposed strategy. The estimates
are necessarily somewhat speculative, but are consistent with the foregoing
control strategy analysis and interviews with appropriate administrators
and staff of pertinent local agencies in Phoneix.
The summary of Table 3-9 shows the relative difficulty of implementing
any of the measures is very similar. Without the benefit of a demonstra-
tion model to provide general awarene*ss and to support the suitability of
the proposed area wide strategy, each of the measures is likely to encounter
substantial socioeconomic resistance. Additional annual funding of about
$4.4 million would be needed to support the measures, most of which would'
be generated by increased taxes or direct assessment. Socioeconomic
resistance is compounded by the uncertainties inherent in the control
strategy development, and the subsequent difficulty in justifying expenditures
with minimum risk of expected benefits. None of the measures face diffi-
cult technical problems with the possible exception of the intensive street
cleaning proposal.
The lower half of Table 3-9 presents estimates of implementation
difficulties subsequent to conducting a demonstration model strategy
in a limited area of the Phoenix study region. Presuming the model is
conducted successfully, yielding a public awareness of the various bene-
fits (including air quality improvements) to be gained from widespread
implementation of the model elements, and dismissing speculative uncertainties
3-40
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TABLE 3-9. IMPLEMENTATION DIFFICULTY OF CONTROL STRATEGY
to
I
CONTROL
MEASURES
WITHOUT DEMONSTRATION MODEL:
1. Intensive Road Paving
2. Lower Speed Limit on Unpaved
Dirt Roads
3. Intensive Street Cleaning
'4. Wetting of Construction Site
Unpaved Access Roads
5. Sweeping Paved Access Roads Used
By Construction Vehicles
6. Stablize Cleared Areas of
Construction Sites
AFTER IMPLEMENTATION OF DEMONSTRATION
MODEL
1. Intensive Road Paving
2. Lower Speed Limit on Unpaved
Dirt Roads
3. Intensive Street Cleaning
4. Wetting of Construction Site
Unpaved Access Roads
5. Sweeping Paved Access Roads Used
by Construction Vehicles
6. Stabilized Cleared Areas of
Construction Sites
*
SEVERITY OF
TECHNICAL
1
1
2
1
1
1
1
1
2
1
1
1
IMPLEMENTATION
POLITICAL LEGAL
1
2
'2
2
2
2
1
1
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
1
2
DIFFICULTY
SOCIOECONOMIC
3
3
3
3
3
3
2
1
2
1
1
2
OVERALL
SEVERITY
6
7
8
7
7
8
5
4
6
6
4
6
-------
surrounding the appropriateness of the measures, the remaining obstacles
limiting the full scale institution of the strategy are expected to be
resolvable. The ingredients of the demonstration model are discussed
.in the following section.
3.7 DEMONSTRATION MODEL
The proposed measures of the control strategy are reasonable in terms
of their technical, institutional, economic, and legal feasibility. How-
ever, because of substantial socioeconomic resistance associated with the
measures, it is proposed that a demonstration model be formulated and in->
eluded as a prerequisite to implementation of the overall control strategy.
The model strategy would be useful in a number of ways. First, the model
Would be instrumental in generating the public acceptance needed for
eventual financial support of the total strategy. Second, the demonstra-
tion would promote committment from local agencies as participants
in dust control objectives. Finally, the demonstration program is essential
as a tool for pollution control analysis as it would yield useful insights
for appropriate adjustments of the region-wide strategy.
There is substantial indication the local control demonstration would
result in significant air quality improvement. The evidence shows clearly
that local sources are affecting the Hi-Vol monitor measurements dramati-
cally. The cost of controlling these sources may well be less than the
cost of the air pollution consequencies, and the specific controls are
compatible with other city and county planning objectives. Hence, the
local control demonstration is a very appropriate vehicle for persuasion,
with very little risk involved. '
The demonstration model must be formulated carefully, and should
consist of the following elements:
Surveys to establish understanding of pertinent value forces
operating among the various social sectors.
3-42
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A cooperative task force committee comprised of representatives
from the major affected local departments (i.e., Department of
Transportation, County Highway Department, Agricultural Exten-
sion Service, County Legal Services, Maricopa County Health
Department, etc.). The committee would be responsible for the
planning of the model strategy.
A field test to demonstrate the effect of the proposed control
measures in a limited area. This test would include institution
of all controls proposed for the area-wide strategy. A com-
prehensive TSP field monitoring program would be implemented.
A detailed economic analysis to evaluate the economic consequences
of particulate air pollution in Phoenix, and the cost benefits
of the proposed dust control strategy.
A public relations program to promote awareness of the benefits
of the proposed dust control and to generate support for funding
measures needed to implement the measures.
The selection of the specific area for the model demonstration would be
dependent on several factors. First, receptibility of the various local
agencies to participate in the model test should be assurred. Discussions
with various departments of the City of Phoenix and Maricopa County have
indicated a positive disposition to participate in both the funding and
implementation of a model demonstration program [1, 15, 16, 11, 22]. The
position of additional affected agencies should be surveyed, and the disposi-
tion of local agencies in unincorporated cities of the study area should be
investigated. Second, the test area should be representative of air quality
and major emission sources causing high levels of TSP throughout the study
area. Controls for the three major fugitive emission sources can then be
tested and evaluated during the single demonstration program. Third, it would
be preferable if the selected area included a monitor of the existing air
3-43
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sampling network. This would facilitate the comparison between control and
after control air quality, and would place the test program within the context
of the present study framework. Fourth, since a key to the utility of the
test model is its effect on social acceptance, the area selection should
reflect a level of social acceptance typical of that characteristic of the
region targeted for control strategy application. Another, but not necessari-
ly final consideration in test area selection is the scheduled planning for
the area. Desirability for selection of the area is increased when scheduled
development is compatible with the specific controls comprising the demonstra-
tion model.
Selection of a test area should be based on a prioritized ranking of
each of the above (and other) selection factors, and the specific charac-
terization for the various candidate areas being considered.
3-44
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REFERENCES
1. Maricopa County Highway Department, Personal communication, June 1976.
2. City of Phoenix Department of Transportation, street maintenance data
compiled for internal use by the department, July 1975.
3. Roberts, J.W., and H. A. Matters, "Cost and Benefits of Road Dust
Control in Seattle's Industrial Valley," Journal of the Air Pollution
Control Association, September 1975.
4. Jutze, G., and K. Axetell, PEDCO Environmental Specialists, Inc.,
"Investigation of Fugitive Dust, Volume I - Sources, Emissions, and
Control," June 1974.
5. Roberts, J.W., A. T. Rossano, P.T. Bosserman, G.C. Hafer, and H.A.
Watters, "The Measurement, Cost and Control of Traffic Dust and Gravel
Roads in Seattle's Duwamish Valley," Paper No. AP-72-5, presented at
the Annual Meeting of the Pacific Northwest International Section of
the Air Pollution Control Association, November 1972.
6. Cowherd, Chatten; Axetell, Kenneth; Midwest Research Institute,
"Development of Emission Factors for Fugitive Dust Sources," June 1974.
7. Sehmel, G.A., "Particle Resuspension from an Asphalt Road Caused by
Vehicular Traffic," BNWL-1651 PT1.
8. Sartor, James, Gail Boyd, "Water Pollution Aspects of Street Surface
Contaminants," Prepared for U.S. Environmental Protection Agency,
November, 1972.
9. American Public Works Association, "Water Pollution Aspects of Urban
Runoff," APWA, Chica o, 1969.
10. TRW Environmental Engineering Division, "Development of an Implementation
Plan for Suspended Particulate Matter in the Phoenix Area," Volume 2,
Prepared for Environmental Protection Agency, May 1976.
11. City of Phoenix Department of Transportation, Personal communication,
July 1975.
12. City of Phoenix Arizona, "1975 Accelerated Major Street Program,"
July 1975.
13. Sultan, Hassen A, Arizona Transportation and Traffic Institute,
"Soil Erosion and Dust Control of Arizona Highways Part IV Final
Report Field Testing Program," Prepared for Arizona Department of
Transportation, November 1975.
14. Hawkins Company, Phoenix, Arizona, Personal communication, July 1970.
15. Phoenix Department of Transportation and Road Maintenance, Personal
communication, June 1976.
R-l
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REFERENCES (continued)
16. Maricopa County Bureau of Air Pollution Control, Personal communication,
June 1976.
17. TRW Environmental Engineering Division, "Development of an Implementa-
tion Plan for Suspended Particulate Matter in the Phoenix Area," .
Volume 3, Prepared for Environmental Protection Agency, August 1976.
18. Horton, D., Ecolatec, Inc., "Effectiveness of Vacuum Sweepers,"
American Public Works Association Reporter, April 1976.
19. Ecolotec, Inc., Personal communication, September 1976.
20. Midwest Research Institute, "Quantification of Dust Entrainment
from Paved Roadways," Prepared for Environmental Protection Agency,
March 1976.
21. Trijonis, J., TRW Environmental Engineering Division, "An Imple-
mentation Plan for Suspended Parti.culate Matter in the Los Angeles
Basin," March 1975.
22. City of Phoenix Department of Transportation, Personal communication
with City.Tra.ffic Engineer, May 1976.
23. TRW Environmental Engineering Division, "Development of an Implementa-
tion Plan for Suspended Particulate Matter in the Phoenix Area,"
Volume 1, Prepared for Environmental Protection Agency, March 1976.
24. Olsen, R.H., Boeing Technology Services, "The Suspended Particulate
Problem in Seattle's Duwamish Basin," Presented at the Pacific
Northwest International Section of the Air Pollution Control
Association Annual Meeting.
25. Roberts, J.W., A. T. Rossano, P. T. Bosserman, C. G. Hafer, and H. A.
Watters, "The Measurement, Cost and Control of Traffic Dust and Gravel
Roads in Seattle's Duwamish Valley," Paper No. AP-72-5, presented at
the Annual Meeting of the Pacific Northwest International Section
of Air Pollution Control Association, November 1972.
26. Scott, John B., Director of Research, "The American City 1970 Survey
of Street Sweeping Equipment," The American City and the Municipal
Index, December 1970.
27. Laird, Carlton W., Scott, John, "How Street Sweepers Perform Today ...
in 152 selected cities across the nation," The American City,
and the Municipal Index, December 1970.
28. Jackson, R.D., City of Columbus, Ohio, Department of Public Service,
"Street Cleaning, the Best Way," presented at the Governmental Refuse
Collection and Disposal Association Seminar and Equipment Show,
Santa Cruz, California, November 1973.
R-2
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29. Elgin Leach Corporation, Illinois, Personal communication, October
1976.
30. Los Angeles Department of Street Maintenance, Personal communication,
October 1976.
31. Long Beach Department of Street Services, Personal communication,
October 1976.
32. City of Phoenix Department of Street Services, Personal communication,
October 1976.
33. Central Engineering Company, Inc., Milwaukee, Personal communication,
October 1976.
34. Super Vac Sweeping Service, Alhambra, California, Personal communi-
cation, October 1976.
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-450/3-77-021d
2.
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
An Implementation Plan for Suspended Particulate
Matter in the Phoenix Area, Volume IV, Control
Strategy Formulation
5. REPORT DATE
June 1977
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
George Richard
9. PERFORMING ORGANIZATION NAME AND ADDRESS
TRW
Environmental Engineering Division
One Space Park
RpHnpHn Rparh Tali form' a
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-01-3152
12. SPONSORING AGENCY NAME AND ADDRESS
13. TYPE OF REPORT AND PERIOD COVERED
U. S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Research Triangle Park, N.C. 27711
Final
14. SPONSORING AGENCY CODE
200/04
15. SUPPLEMENTARY NOTES Vol ume j f Air Quality Analysis - EPA 450/3-77-021a; Volume II
Emission Inventory - EPA 450/3-77-021J>; Volume III, Model Simulation of Total
Partinilate Matter Levels - EPA 450/3-77-021c ; Volume IV. Control
16. ABSTRAC
strategy' Formal atlon - EPA 450/3-77-021;d
This document is one volume of a four volume report presenting an implementation
plan for control of suspended particulate matter in the Phoenix area.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COS ATI Field/Group
Particulate Matter
Total Suspended Particulate
Emission Sources
Control Methods
Fugitive Dust
Air Quality Measurements
18. DISTRIBUTION STATEMENT
Release Unlimited
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
94
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
R-4
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