EPA 910/9-81-083
United States
Environmental Protection
Agency
Region 10
1200 Sixth Avenue
Seattle WA 98101
Air
February 1981
Carbon Monoxide Study
Spokane, Washington
November 21-December 19, 1980
Executive Summary
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CARBON MONOXIDE STUDY
SPOKANE, WASHINGTON
EXECUTIVE SUMMARY
NOVEMBER 21 - DECEMBER 19, 1980
PREPARED BY
JON W. SCHWEISS
SURVEILLANCE AND ANALYSIS DIVISION
FOR
AIR PROGRAMS BRANCH
AIR AND HAZARDOUS MATERIALS DIVISION
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION 10
1200 SIXTH AVENUE
SEATTLE, WASHINGTON 98101
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DISCLAIMER
This report has been reviewed by the Environmental Protection Agency
Region 10 and is approved for publication. Approval does not signify
that the contents necessarily reflect the views and policies of the
Environmental Protection Agency nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
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PREFACE
Under the Clean Air Act of 1970, the U.S. Environmental Protection Agency
has established standards for carbon monoxide in air external to
buildings to which the public has access. In a number of cities,
including Spokane, these standards have not yet been attained. Plans to
achieve the standards are required under the Clean Air Act Amendments of
1977 (PL 95-95). It is hoped that the material presented in this report
will assist in formulating and evaluating such plans for achieving
attainment of the standards.
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ABSTRACT
An ambient air sampling program was designed and implemented to obtain
information relative to the magnitude and spatial distribution of carbon
monoxide levels in Spokane's central business district. Integrated bag
samples were collected from a 16 site study network during 20 weekdays
spanning November and December of 1980. Samples from each site were
analyzed by the non-dispersive infrared method to yield a daily 8-hour
average concentration for comparison with values reported by the four
permanent monitors sited in the study area. Sampling and analytical
protocols were developed in concert with rigorous quality control
provisions to ensure the collection of valid, comparable data.
Using an array of linear regression formulas arising from analysis of the
study data, the permanent monitoring network effectively characterized
carbon monoxide concentrations at all study sites. The permanent
monitoring network also adequately represented the maximum carbon
monoxide concentration reported from the study network, compared without
respect to day of occurrence. However, the permanent monitoring network
was less successful in representing the daily maximum, and on occasion,
exhibited sub-exceedance values when a study site elsewhere in the study
area reported an exceedance of the 9.0 ppm 8-hour standard.
On balance, the study results indicate that the carbon monoxide problem
is areawide in the study portion of downtown Spokane, and is primarily
the result of highly localized contributory factors. Further, the study
established the potential efficacy of using data generated by the
existing permanent monitoring network to characterize carbon monoxide
levels at other locations in the central business district.
iv
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ACKNOWLEDGEMENTS
I gratefully acknowledge the assistance of members of the Washington
State Department of Ecology and the City of Spokane. With their
cooperation and special efforts, difficult obstacles to the
implementation of this study were either surmounted or wholly avoided.
Finally, I wish to express my gratitude to many members of EPA Region
10's staff, especially those of the Surveillance & Analysis Division for
their guidance and assistance.
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TABLE OF CONTENTS
Page
Preface Hi
Abstract iv
Acknowledgements v
Table of Contents vi
List of Figures vii
List of Tables viii
Introduction 1
Summary 7
Conclusions and Recommendations ........ 11
vi
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LIST OF FIGURES
Figure Page
1 On-Street Parking Prohibitions 4
2 Location of EPA Sampling Sites 8
3 Maximum 8-Hour Values for Entire Sampling Interval 12
4 Characteristics of Weekday Carbon Monoxide Average
Concentrations for an 8-Hour Period at Each Site 13
5 Characteristics by Day of the Composite Range of
Carbon Monoxide Concentrations for All Sites
During an 8-Hour Period 15
6 Frequency of 8-Hour Values Greater Than 9.0 ppm 18
7 Day of Highest Average Over All Sites 21
8 Average of Each Site's 8-Hour Values for Entire
Sampling Interval 22
VM
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LIST OF TABLES
Table Page
1 Spokane CO Study Sampling Site Location 9
viii
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INTRODUCTION
Since 1968, when routine ambient monitoring began in Spokane's Central
Business District (CBD), violations of the 8-hour National Ambient Air
Quality Standard (NAAQS) for carbon monoxide* (CO) have been recorded at
several sites operated by the Washington State Department of Ecology.
However, additional information concerning the severity and spatial
distribution of the CO problem in Spokane's CBD was sought to-assist in
evaluating the relationship between permanent monitors and CO
concentrations elsewhere in the CBD. A study was conceived and conducted
to address these needs. This report presents the major results and
conclusions derived from the study.
While several methods exist by which to compare data from the study sites
and the permanent monitors, two basic approaches are presented in this
report to examine the representativeness of the permanent monitors.
The first approach compares data on a day-by-day basis (Type 1
approach). Because the study sites were sampled during just one 8-hour
period (10:00 a.m. to 6:00 p.m.) each day, data from the permanent
monitors for the identical period were chosen for purposes of temporal
*
congruity, permitting comparisons of relative concentrations throughout
the study area. Data from the permanent monitors for other
*Established by EPA as 9 ppm and not to be exceeded more than once per
year.
-1-
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periods outside the daily study interval are available for additional
analyses of variability during a day. These analyses will not be
attempted at this time.
The second approach (Type 2) compares data from the entire 20-day study,
regardless of whether the compared data share the same day of
occurrence. This method of analysis lends itself towards examining
patterns and frequencies of concentrations throughout the study area.
Data for the designated study period (10:00 a.m. to 6:00 p.m.) from study
sites and permanent monitors were compared using this approach.
The study results that follow are distillations of the most significant
results and conclusions stemming from a second and more extensive
treatment. Because of time constraints, a second more detailed report
will not be performed now. All data pertinent to the sampling and
quality, assurance aspects of the study will be available from EPA's
Regional office in Seattle. The state monitoring data may be obtained
from the Washington State Department of Ecology (DOE) in Olympia,
Washington. It should be noted here that all DOE monitoring data are
unvalidated and incomplete at this writing and are subject to further
editing, although only minor changes are anticipated. Meteorological •
data originating at Spokane International Airport were accessed from the
National Weather Service. This source of data is some distance from the
CBD and the relationship of meteorology at the airport with that in the
CBO is not well known.
-2-
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Meteorological data more proximate to the study area were being collected
at sites operated by the Washington State Department of Transportation,
but are unavailable at this time. Finally, traffic counters were not
operated at the temporary monitoring sites, except in those random
instances where an EPA site happened to coincide with a short-term
traffic count survey operated by the city as part of its routine program.
The reader's attention is called to the following qualifications borne by
the study results:
1) The study was conducted following the city's implementation of a
limited parking ban (see Figure 1) aimed at reducing congestion
on the major legs (Washington, Stevens, Lincoln, and Monroe
Streets) carrying traffic through the C8D. The effect this
parking ban has on traffic dynamics and CO levels in these legs,
and streets interior to them, is not known. This situation
encumbers comparisons of this data with data generated under
some other condition.
2) Due to the nature of the sampling effort and the report
deadline, only data generated in the study period (10:00 a.m. to
6:00 p.m.) were considered for correlative analysis. Just as
the inter-site relationships may exhibit some degree of daily
variability, these relationships may also vary during periods
within a day for which comparable study data are unavailable.
This report makes no attempts to quantify this variability, but
relies solely on the merit of relativistic analyses from which
to make statements on the significance of study results.
-3-
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City of Spokane
On-Street Parking Prohibitions
Implemented September, 1980
Legend
Illllll Denotes peak period prohibition
Denotes all hour prohibition (existing)
CD
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3) Due to the nature of the sampling methodology, some
uncertainties about the absolute veracity of the data have been
recognized and accepted by us from the study's inception.
Intensive measures were taken to ensure the collection of data
having both high and demonstrable quality. Correlative analysis
of data returned by collocated study sites and permanent
monitors indicate excellent agreement. In light of these
results and because rigorous quality control functions were
applied uniformly throughout the entire study network, we are
reasonably assured that the network produced data of acceptable
precision, accuracy, and comparability.
4) There are limitations an abbreviated (20-day) study can impose
on interpretive efforts. The transitory nature of CO
contributory parameters such as meteorology and traffic dynamics
may induce "anomalous" short-term conditions to which short
duration studies of this sort can be oversensitive.
By way of illustrating this last point, the preliminary indication by the
National Weather Service is that during the study interval, the seasonal
stability that typically characterizes Spokane's winter meteorology was
somewhat less severe and persistent than usual, which would tend to
reduce CO levels other factors being equal. Additionally, retail sales
were reportedly off in the central business district during the holiday
season, which would imply some reduction in the typical traffic burden,
thereby effecting a depression of CO levels, other factors being equal.
-5-
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Given the combined impact these somewhat anomalous meteorological and
economic situations exert in the suppression of CO levels, data generated
by the study should probably be regarded as conservative, or
underpredicting in nature.
Finally, routine activities such as building construction and street
maintenance introduce relatively short-term perturbations to traffic
patterns and flow which may either suppress or exacerbate CO levels.
These situations occurred at several locations throughout the CBO and
were logged when observed. The ongoing incidence of these activities at
various locations within the CBO should be considered "normal".
These considerations are not mentioned in order to devalue the study
results in any way, but only to frame them in their proper context for
use in making long-term inferences. This serves to underscore the
necessity of long-term monitoring in strategy formulation and the
tracking of standards attainment.
-6-
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SUMMARY OF RESULTS
In 1980, a 20-day study of carbon monoxide levels at sixteen ambient
sampling sites was conducted in Spokane's C8D during November and
December, the "season" when high and persistent concentrations of CO
historically occur. The study was directed towards collecting data
relative to the magnitude and spatial distribution of CO concentrations
for comparison with data retrieved from the permanent monitoring sites.
Following the completion of an analysis* aimed at screening areas for
"hot-spot" potential to aid in the design of the sampling network, EPA
engaged a contractor** to conduct the field portion of the study. On
each weekday (except Thanksgiving day), two sets of 4-hour integrated bag
samples representing the 10:00 a.m. to 2:00 p.m. (AM sample) and the 2:00
p.m. to 6:00 p.m. (PM sample) intervals were collected from the 16
sampling sites (see Figure 2 and Table 1). The AM and PM bag samples
were in turn analyzed via the NDIR (non-dispersive infrared) method, and
the resultant concentrations averaged to yield an 8-hour value,
permitting comparison with the 8-hour standard of 9.0 ppm for CO.
Data are summarized in bar charts of the measurement distribution for
each site and each day of the study period, and in histogram-maps
exhibiting the spatial distribution of CO. Results from the study sites
were compared in several ways with data from the state sites, available
meteorological data, and,w-ith each other.
*EPA's Carbon Monoxide Hot-Spot Guidelines. EPA-450/3-78-035.
** Alsid, Snowden and Associates; Bellevue, Washington.
-7-
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Spokane Carbon Monoxide Study
Location of EPA Sampling Sites
11/21/80 to 12/19/80
o
State Site
O
EPA Site
P.O. - POST OFFICE
C.H. - COURT HOUSE
L.S. - LIQUOR STORE
F.B. • FERNWELL BDLG.
3!
CD
CD
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SPOKANE CO STUDY— NOV. 21 TO DEC.
SAMPLING SITE LOCATION
EPA STUDY
SITE NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
SITES
PRIMARY STREET
SPOKANE FALLS BLVD.
SPOKANE FALLS BLVD.
MALL
MAIN
MAIN
HOWARD
RIVERSIDE
RIVERSIDE
STEVENS
WASHINGTON
FIRST
SPRAGUE
MONROE
RIVERSIDE
POST
MAIN
TABLE 1
19, 1980
CROSS STREET
W/0 WALL
W/0 WALL
S/0 SPOKANE FALLS
W/0 HOWARD
W/0 HOWARD
S/0 MAIN
W/0 STEVENS
W/0 STEVENS
S/0 MAIN
S/0 RIVERSIDE
W/0 STEVENS
W/0 WALL
S/0 SPRAGUE
W/0 POST
S/0 MAIN
W/0 POST
SIDE OF STREET
N
N
BLVD. W
N
S
E
' N
S
E
W
N
N
E
N
E
N
STATE PERMANENT MONITORING SITES
Post Office (PO) LINCOLN
(Station No.: 3278013A)
Liquor Store (LS) SPRAGUE
(SAROAD No.: 49 2040,027 F01)
Fernwell Bldg. (FB) RIVERSIDE
(Station No.: 3278033A)
City Hall .(CH) WALL
(Station No.: 3278001A)
S/0 MAIN
W/0 WALL
W/0 STEVENS
S/0 SPOKANE FALLS BLVD. W
-9-
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The study indicated that the carbon monoxide problem is not restricted to
the immediate vicinity of the permanent sites, but pervades the CBO. This
is evidenced by the fact that 12 of the 16 study sites, or 75%, exhibited
at least one "exceedance"* of the 8-hour NAAQS for CO. Comparisons of the
8-hour averages at the study sites and the permanent monitors revealed
that the highest 8-hour average at a study site (13.7 ppm) was about the
same as that measured at any of the permanent monitors (13.0 ppm) for the
corresponding 10:00 a.m. to 6:00 p.m. interval.
Of the permanent monitors, the one located at the Post Office on Lincoln
Street south of Main Avenue, had the maximum 8-hour average, the
2nd-highest 8-hour average, the highest average of 8-hour values over the
entire study interval, and the greatest frequency of exceedances. A study
site on Riverside Avenue experienced a slightly higher maximum 8-hour
concentration, though one less exceedance of the standard. However, two
other study sites equalled the Post Office monitor in number of exceedance
values. Significantly, the Post Office permanent monitor did not exhibit
an 8-hour exceedance on 3 of the 6 days when at least one site in the
study network did so and for which comparative data was available. In
fact, when the permanent sites are considered in aggregate, they did not
produce an exceedance value on 2 of the 6 days when at least one study
site did so and where comparative data were available. Conversely, at
least one site in the study network, excluding those collocated with the
permanent monitors, exhibited an exceedance when one was reported from
among the permanent monitors.
*An exceedance is defined as any 8-hour average concentration of CO
greater than the 9.0 ppm standard.
-10-
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CONCLUSIONS AND RECOMMENDATIONS
The primary conclusions drawn from the results of a CO sampling study
conducted in Spokane on weekdays of November and December, 1980 during
the 10:00 a.m. to 6:00 p.m. interval are:
1. The severity of carbon monoxide concentrations in the CBD as
measured by the maximum 8-hour 10:00 a.m. to 6:00 p.m.
concentrations, compared without respect to day of occurrence,
was adequately represented by the permanent monitor located at
the Post Office on Lincoln Street south of Main Avenue (.see
Figures 3 and 4).
During the study period, the maximum 8-hour CO
concentration among all study sites was 13.7 ppm, occurring
on December 12th at site 14 on Riverside west of Post.
This was essentially the same as the maximum value
experienced at the permanent monitors during the study
period (13.0 ppm, also on December 12th, at the Post Office
monitor, located on Lincoln south of Main).
About 38% of the study sites (5 of the 13 sites not
collocated with permanent monitors) experienced at least
one 8-hour average concentration within 2.0 ppm of the
highest 8-hour value reported by the permanent monitors,
demonstrating the spatial severity of concentrations in the
study area. (Note that these are comparisons of the
maximums during the 20-day study period and did not
necessarily occur on the same day.)
-11-
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ISi
LEGEND
Denotes State Site
I Denotes Values Greater Than 9.0 PPM of C.O.
&
^ *$
CARBON MONOXIDE
CONCENTRATIONS
11/21/80 to 12/19/80
SPOKANE CENTRAL BUSINESS DISTRICT
MAXIMUM 8-HOUR1 VALUES FOR ENTIRE
SAMPLING INTERVAL
CO
'10 AM TO 6PM
Scale in PPM C.O. 0-
-------
Spokane Carbon Monoxide
November 21 to December 19,1980
(Weekdays Only)
Characteristics of Weekday Carbon Monoxide Average
Concentrations for an Eight-Hour Period
(10:00 a.m. to 6:00 p.m.) at Each Site.
20.0-r
Q.
O.
15.0- -
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10.0- -
9.0 -
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^-Number of values greater than 9.0 ppm
Maximum
2nd highest
Mean + one standard deviation
Mean
—Mean - one standard deviation
Minimum
•Collocated with CH
"Collocated with FB
"•Collocated with LS
Standard of 9.0 ppm not to be exceed
more than once per year
1 1 1
ft
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SITE NUMBER
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The maximum 8-hour averages at each of these five study
sites (sites 7, 9, 10, 13, and 14) exceeded the maximum
reading of 11.0 ppm at the Liquor Store monitor (located on
Sprague Avenue west of Wall Street), which was the next
highest maximum reading from a permanent monitor.
About 69% or 9 of the 13 study sites not collocated with
permanent monitors produced 8-hour maximum values which
equalled or exceeded the maximum 8-hour concentrations of 9
ppm and 9.4 ppm reported from the City Hall (Wall Street
south of Spokane Falls Blvd.) and Fernwell Building
(Riverside Avenue west of Stevens Street) permanent
monitors, respectively.
2. The permanent monitoring network did not necessarily represent
the daily 10:00 a.m. to 6:00 p.m. maximum CO concentration
within the study area for this 20-day period (see Figure 5).
On 61% of the days (11 of the 18 days for which comparable
data is available), the highest 8-hour value measured at a
study site not collocated with a permanent monitor, clearly
exceeded values at the permanent monitors, by an average of
about 2 ppm and a maximum of about 3 ppm. The maximum
daily value from among the permanent monitors clearly
exceeded that value from the study sites on 11% (2 of 18)
of the days, by an average of about 1 ppm. The daily
maximum values from both permanent monitors and study sites
were roughly equal (uncertain because of state-rounding
procedures) on 28% (5 of 18) of the days.
-14-
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Spokane Carbon Monoxide
November 21 to December 19,1980
Characteristics by Day of the Composite Range of
Carbon Monoxide Concentrations for all Sites
During an Eight-Hour Period
(10:00 a.m. to 6:00 p.m.).
Number of eight-hour values greater than 9.0 ppm
Maximum
Mean + one standard deviation
Mean
Mean - one standard deviation
Minimum
• Standard of 9.0 ppm not to be exceeded
more than once per year
tn
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20.0-
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EIGHT-HOU
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-5.0
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DATE (1980)
-------
The maximum 8-hour average of the day did not always occur
at the same sites. Excluding from consideration those
study sites (3, 8, and 12) collocated with permanent
monitors, study sites 4, 5, 7, 9, 10; 13, and 14 and
permanent monitors at the Post Office, City Hall and
Fernwell Building all were maximum, or shared that
distinction, on at least one day during the study, for
which comparable state and study data are available (18
days). Site 9 was highest on 22% of the days. Site 10 was
highest on only 6% of the days, but was equal to the
highest reading on an additional 17% of the days, each time
with either or both the Post Office and Fernwell Building
permanent monitors. Site 5 was highest on 17% of days.
Sites 13 and 7 were each highest on 11% of the days, and
equally the highest an additional 6% of the days. Sites 4
and 14 were each highest on 6% of the days. Of the
permanent monitors, the Post Office equalled the highest
reading on 22% of the days, three times with study site 10,
and twice with the Fernwell Building. Finally, the City
Hall permanent monitor had the daily maximum on 6% of the
days.
3. On occasion, the permanent monitoring network exhibited
sub-exceedance values when study sites elsewhere in the study
area reported exceedances of the standard.
-16-
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The 8-hour standard was exceeded at one or more of the
study sites on 35% (7 of 20) of the study days.
Exceedances at one or more of the permanent monitors
occurred on 20% (4 of 20) of. the sampled days. Two days of
state data were invalidated due to system malfunctions,
during one of which a study site (13) showed an exceedance
(10.6 ppm).
When considered on an individual site basis, the Post
Office permanent monitor was representative of the
frequency of exceedances within the study area, at 17% (3
of 18 days). This figure was equalled at study sites 9 and
10 (see Figure 6).
The frequency of exceedances at the permanent monitors
ranged from 0% at City Hall to 17% of the sampled days at
the Post Office.
4. Using the results of linear regression analyses, the permanent
monitoring network was effective in characterizing CO
concentrations at all study site locations. Two types of linear
regressions were performed: simple paired linear regressions,
and multiple linear regressions (MLR) where data from three
permanent monitors were input as "independent" predictors of a
"dependant" study site value.
-17-
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CONCENTRATIONS
c\^y LEGEND
, {>y 0- Number of Days 9.0 PPM Exceeded
11/21/80 to 12/19/80
^'
SPOKANE CENTRAL BUSINESS DISTRICT
nxDenotes Frequency* of 10:OOAM to 6:OOPM Periods
FREQUENCYW 8-HOUR2VALUES
GREATER THAN 9.0 PPM
210 AM TO 6 PM
ESS THAN 20 SUCCESSFUL SAMPLING DAYS OCCURED AT SOME
SITES
Where CO Averaged More Than 9.0 PPM
\~ State Site 'ROUNDED TO NEAREST 5%
(Q
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(FIXED BAR HEIGHT REPRESENTS 100% OF DAYS IN WHICH SUCCESSFUL SAMPLING OCCURED)
-------
The highest coefficient of correlation resulting from the
regression analyses for each study site was always greater
than 85%. Excluding from consideration those study sites
collocated with permanent monitors, 9 of the 13 remaining
study sites had regression correlation coefficients of 94%
or better.
Considering individual permanent monitors, data from the
Liquor Store monitor exhibited the most extensive
correlation with data from the study sites. It showed a
correlation coefficient of 80% or better for 11 of the 16
study sites. The Post Office monitor had correlation
coefficients of 80% or more for 5 of the 16 study sites.
The City Hall and Fernwell Building had no correlation
coefficients greater than 80%, excluding their collocated
study sites.
When considering the four possible combinations of three
permanent monitors in the multiple linear analysis, three
combinations, (1 - Post Office, Liquor Store, City Hall, 2
- Post Office, Liquor Store, Fernwell Bldg., 3 - Liquor
Store, Fernwell Bldg., City Hall), had or shared the
highest correlation coefficient at 9 or 10 of the 13 study
sites (the three study sites collocated with the permanent
monitors were excluded from the comparison). Finally, the
Post Office, City Hall, and Fernwell Building combination
had the highest correlation coefficient at just 1 of 13
study sites.
-19-
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5. Carbon monoxide concentrations were lower at some locations in
the CBO than others for corresponding intervals (see Figures 7
and 8).
For 25% of the study sites (sites 1, 2, 15, and 16) no
8-hour values exceeding the 9.0 ppm standard were reported
during the 20-day study.
Relatively low concentrations were observed at sites 1 and
2, which were located in areas offering good ventilation.
For these sites the averages of all eight-hour values were
2.0 and 3.5 ppm respectively. Study site 1, located about
75 meters from the nearest street, had the daily minimum
8-hour value on all 20 sampling days, and probably
approximates background concentrations of CO. Eight-hour
concentrations at site 1 ranged from .8 to 3.4 ppm during
the study interval.
On occasion, sites on one side of the street showed high,
even exceedance values, when sites directly across the
street reported lower, sub-exceedance values. This
occurred several times at both sets of "cross-street
pairs": sites 4 and 5 on Main west of Howard and sites 7
and 8, on Riverside west of Stevens. The former pair had a
near random linear correlation coefficient of 4%, while the
latter pair had one of 56%.
-20-
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LEGEND
H Denotes State Site
I Denotes Values Greater Than 9.0 PPM of C.O.
&-
CARBON MONOXIDE
CONCENTRATIONS
11/21/80 to 12/19/80
SPOKANE CENTRAL BUSINESS DISTRICT
DAY1 OF HIGHEST AVERAGE OVER ALL SITES
31
co'
c
12/12/80 - 10 AM TO 6 PM
Scale in PPM C.O.
-------
ro
ro
LEGEND
Denotes Slate Site
| Denotes Values Greater Than 9.0 PPM of C.O.
CARBON MONOXIDE
CONCENTRATIONS
11/21/80 to 12/19/80
SPOKANE CENTRAL BUSINESS DISTRICT
AVERAGE OF EACH SITE'S 8-HOUR1 VALUES
FOR ENTIRE SAMPLING INTERVAL
(Q
C
3
op
110AMT06PM
Scale in PPM C.O.
-------
It is recommended that:
1. The carbon monoxide situation in Spokane be considered an
area-wide problem in the study portion of the CBO, .as opposed to
a few isolated "hot spots". While examination of the
"cross-street pair" and "background" data analyses-confirms that
CO levels are primarily expressions of highly localized factors,
it should be recognized that the CBO offers an extensive array
of sites which fit the "hot-spot" scenario.
2. Concentrations at the permanent monitoring network above 9.0 ppm
be considered as indicative of concentrations equally high or
higher elsewhere in the study area at the same time. However,
should the permanent monitors measure concentrations under the
9.0 ppm (in the 5 to 9 ppm range) standard on a particular day,
it should not be construed as assurance that air quality
standards are being met throughout the study area on the same
day.
3. Given the current mix of non-meteorological parameters within
the study area, the Post Office permanent monitor be considered
as a candidate site to represent peak CO levels in downtown
Spokane for routine monitoring. However, the Liquor Store
monitor should be utilized as the single, most representative
site from which to infer CO levels at other sites within the
study area, as calculated from regression results.
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4. Concentrations at the permanent monitoring network be input to
the appropriate multiple .linear regression formula and the
output used to characterize concentrations at locations other
than at the permanent monitors.
5. Planning for future studies to aid development and/or revision
of control strategies to attain the NAAQS should consider the
possible utility of ancillary data on traffic and meteorological
parameters to aid data interpretation.
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA 910/9-81-083
2.
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
5. REPORT DATE
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
J. W. Schweiss
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
U.S. Environmental Protection Agency, Region X
1200 6th Ave. Surveillance & Analysis Division
Seattle, WA 98101
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
An ambient air sampling program was designed and implemented to obtain infor
mation relative to the magnitude and spatial distribution of carbon monoxide levels in
Spokane's central business district. Integrated bag samples were collected from a 16
site study network during 20 weekdays spanning November and December of 1980. Samples
from each site were analyzed by the non-dispersive infrared method to yield a daily
8-hour average concentration for comparison with values reported by the four permanent
monitors sited in the study area. Using an array of linear regression formulas arisin
from analysis of the study data, the permanent monitoring network effectively charac-
terized carbon monoxide concentrations at all study sites. The permanent monitoring
network also adequately represented the maximum carbon monoxide concentration reported
from the study network, compared without respect to day of occurrence. However, the
permanent monitoring network was less successful in representing the daily maximum,
and on occasion, exhibited sub-exceedance values when a study site elsewhere in the
study area reported an exceedance of the 9.0 ppm 8-hour standard. On balance, the
study results indicate that the carbon monoxide problem is areawide in the study
portion of downtown Spokane, and is primarily the result of highly localized contribu-
tory factors. Further, the study established the potential efficacy of using data
generated by the existing permanent monitoring network to characterize carbon monoxide
levels at other locations in the central business district.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lOENTlFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Carbon Monoxide
Air Quality Data
Air Pollution Sampling
Spokane (Washington)
18. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (ThisReport)
Unrl aqqi fi'pri
21. NO. OF PAGES
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
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