EPA 310, 9-78-055A
United States
Environmental Protection
Agency
Reaion 10
1200 Sixth Avenue
Seattle WA 98101
       Air
           December 1978
      Part 1
      Carbon Monoxide Study
      Boise,  Idaho

      November 25 -
      December 22, 1977


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                                 EPA 910/9-78-055a
 Part 1.  CARBON MONOXIDE STUDY - BOISE, IDAHO



        NOVEMBER 25  - DECEMBER 22, 1977



               EXECUTIVE SUMMARY
                  PREPARED BY




         C. B. Wilson and J.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
                 DECEMBER 1978

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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. Environme ital 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 Boise,



these standards have not yet been attained.  Plans to achieve the standards



are now 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



achieving progress towards attainment of the standards.
                                     iii

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                               ACKNOWLEDGMENTS

We gratefully acknowledge the assistance of many members of the Idaho State
Department of Health and Welfare, the Idaho Transportation Department, and
Ada Planning Association in providing information for the planning and con-
duct of this study.  We especially wish to thank the Idaho State Department
of Health and Welfare for providing facilities to establish a field labora-
tory in Boise for use by the EPA contractor.  A number of individuals gave
freely of their time and information and their efforts contributed materially
to this study, though they are not, of course, responsible for any errors
herein.  These people include: Richard Johnson and Doss Terrel (IDHW), John
Hamrick, Keith Longnecker, and Lee Hatch (ITD); Ervin Olen, Jr.  and Robert
Winter, Jr. (APA).

Several firms and institutions graciously permitted installation of equipment
on their premises and without their cooperation,  portions of this study
could not have been conducted.  Our sincere thanks go to:  St. Luke's Hospi-
tal, Idan-Ha Hotel, Sexty1s Jewelers, David's Fabrics, Singer's, Falk's,  and
Boise State University.

Finally, we express gratitude to many members of the EPA staff for guidance,
encouragement, and assistance.
                                      IV

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                     TABLE OF CONTENTS








                                                       Page



Preface	ill



Acknowledgments  	   iv



Table of Contents	    v



List of Figures	   vi



List of Tables	vii



Abbreviations and Symbols  	 viii



INTRODUCTION 	    1



SUMMARY  	    1



CONCLUSIONS AND RECOMMENDATIONS  	    3



METHOD OF STUDY  	    7



RESULTS AND DISCUSSION 	    8








     Outdoor Sites 	    8



     Indoor Sites  	   26



     Pedestrian Routes 	   26

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                               LIST OF FIGURES
Figure
  1    Sampling Locations .......................    9



  2    Time Distribution of Eight-Hour Averages Over 9.0 ppm



       During November-December for 1975, 1976, and 1977 ........    12



  3    Characteristics of Weekday Carbon Monoxide Average



       Concentrations for an 8-Hour Period at Each Site ........    16



  4    Maximum 8-Hour Values for Entire Sampling Interval .......    18



  5    Frequency of 8-Hour Values Greater than 9.0 PPM .........    19



  6    Second-Highest 8-Hour Values for Entire. Sampling Interval. ...    21




  7    Day of Highest Average Over All Sites .............    23



  8    Characteristics by Day of the Composite Range of Carbon



       Monoxide Concentrations for All Sites During an 8-Hour Period.  .    24
                                      VI

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                              LIST OF TABLES








Table                                                              Page








  1    Boise Carbon Monoxide Sampling Sites 	    10



  2    Maximum Values from Forty Sites and the Permanent Monitor     11*



  3    Comparison of Maximum Study Site and Permanent Monitor



       Eight Hour Averages	    25
                                    vii

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                          Abbreviations and Symbols



AM  -    The four-hour* interval from  10:00 a.m.* to 2:00 p.m.*

PM  -    The four-hour* interval from  2:00 p.m.* to 6:00 p.m.*

AVC -    The eight-hour* average CO concentration for  the 10:00 a.m.*  to

         6:00 p.m.* sample collected at an EPA special study  site  (average

         calculated from AM and PM concentrations)

AVS -    The eight-hour average from 10:00 a.m. to 6:00 p.m.  of continuous

         non-dispersive infra-red measurements at the  permanent monitor

ODD -    The permanent monitor operated by the State at the Odd Fellows Hall

         at 115J Ninth Street

n/o -    north of as in "Ninth n/o Idaho"

w/o -    west of as in "Idaho w/o Eighth"



Exceedence of Standard** - An eight-hour average CO concentration exceeding

                           9.0 ppm

Violation of Standard - The second eight-hour, non-overlapping, running

                           average in  a year to exceed 9.0 ppm
 *  plus or minus fifteen minutes
**  This report discusses only the standard for the eight-hour average and
    does not discuss the standard for one-hour average CO concentrations.
                                     viii

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                                 INTRODUCTION



Frequent violations of the national ambient air quality standard*  for

carbon monoxide (CO) have occurred at the only continuous monitor  in down-

town Boise which is operated at 115J Ninth Street by the Idaho Department of

Health and Welfare (Figure 1).  However, more information on the severity of

the CO problem and its geographical extent was desired to assist in selec-

tion of candidate sites for additional routine monitoring and to examine the

representativeness of the existing site.  The levels of CO encountered by

pedestrians in the city and indoor occupants were also of interest.  There-

fore, a study was planned and conducted to address these needs.  This report

(Part 1) presents the major results and conclusions.  A more detailed de-

scription of the methods, additional discussion and analysis and the data

obtained in this study appear in a separate volume (Part 2).
                                   SUMMARY



In 1977, a 20-day study involving forty outdoor sites, six indoor sites, and

two pedestrian walking routes was conducted in Boise, Idaho during
*  Federal Register, 42 FR8186, April 30,  1971.  The standard for carbon
   monoxide addresses two averaging periods.  Eight-hour average CO concen-
   trations shall not exceed 9 ppm more than once per year.  One-hour average
   CO concentrations shall not exceed 35 ppm more than once per year-

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November-December, the season when high carbon monoxide levels frequently


occur.  The purpose of this study was to obtain additional data regarding

the magnitude and spatial extent of the carbon monoxide problem, the repre-


sentativeness of the only permanent monitor in the central business district,

and to assist in selection of candidate sites for routine monitoring.   On

each week-day, four-hour bag samples were collected from about 10:00 a.m.  to

2:00 p.m. (AM sample) and from about 2:00 p.m. to 6:00 p.m.  (PM sample) at
    •
33 of the outdoor sites and two of the indoor sites.  In addition, bag  sam-

ples of air were collected on two pedestrian walking routes  over two to four


hours during the AM and PM periods.




Data are summarized in bar charts, which show the measurement distribution


for each site or for each day of the study period; in histogram-maps showing

the spatial distribution of carbon monoxide; and in tables.  Results from

the study sites were compared in several ways with data from the permanent


monitor.  Comparisons were also made between study sites along the same


corridor, between indoor sites and adjacent outdoor sites, and between the

two pedestrian routes.  Eight-hour averages were compared with the 9.0 ppm

eight-hour standard.




The study results indicate that the carbon monoxide problem  is widespread

and not restricted to the downtown commercial district.  The magnitude of


the problem may be somewhat greater than shown by data from  the permanent

monitor.  The permanent monitor was generally representative of the higher


but not the highest concentrations.  Even higher concentrations and more


frequent exceedences of the standard occurred on Idaho Street and Main
                                     - 2 -

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Street as well as at a few other sites.  Exceedences  occurred  at  other loca-


tions and were more than  1.5 to 3 times greater than  at  the  permanent  monitor


when no exceedences were  noted at the permanent monitor.  Increases in carbon
                                                           i

monoxide at outdoor sites were frequently reflected by increases  at indoor


sites.  Pedestrians and some of the indoor population were exposed to  concen-


trations above the standard.




Future monitoring should  address the development of control  strategies


(short-term) and then track progress towards achievement of  the ambient air


quality standards (long-term).  Planning for such studies should  consider


the need for related data on traffic characteristics  coupled with meteoro-


logical data.




                       CONCLUSIONS AND RECOMMENDATIONS




The major conclusions of  a 20-day study conducted in  Boise during about


10:00 a.m. to 6:00 p.m. on week-days of November-December 1977 are:





1.   The magnitude of the  carbon monoxide problem was  somewhat greater  than


    indicated by the permanent monitor.




    - For nine study sites, (1, 10A, 11, 13, 17, 18,  20, 24, and  32) the


      maximum 10:00 a.m.  to 6:00 p.m. eight-hour average exceeded the  high-


      est observed at the permanent monitor (13-7 ppm) during the study


      period.
                                     - 3 -

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    - The highest eight-hour average (17.2 ppm) and most frequent exceed-
      ences of the 9.0 ppm standard (70% of the study days) were observed at
      site 32 on Idaho Street west of Eighth Street which most often had the
      highest eight-hour average of all sites (9 of the 20 days).

2.  The spatial extent of the problem encompasses not only the downtown
    commercial district but also locations along traffic corridors outside
    the core area.

    - When higher concentrations were observed in the core area, elevated CO
      levels also occurred elsewhere.

    - Altogether about 70% of the study sites (28 out of 40)  experienced one
      or more days when the eight-hour average exceeded the 9.0 ppm eiqht-
      hour standard.  (A total of nineteen sites experienced two or more
      days).

3.  The permanent monitor was generally representative of the higher concen-
    trations but did not represent the highest concentrations or frequency
    of exceedences within the study area.

    - On every day but one, the eight-hour concentration at the state
      site was exceeded at one or more study sites.
                                     - 4 -

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    - During the survey, the second-highest eight-hour average for 10:00 a.m.
      to 6:00 p.m. at the state site (10.8 ppm) was nearly equalled or ex-
      ceeded at a total of fourteen sites including three in the same block.
      At four sites (10A, 11, 17, and 32), concentrations were more than
      2 ppm greater.

    - On 95% of the study days (19 out of 20) the eight-hour standard was
      exceeded at one or more sites.  Exceedences at the state site occurred
      on 47% (9 out of 19) of the sampled days.

    - Eight-hour concentrations above the standard were observed at other
      locations and were up to three times greater than at the permanent
      monitor when no exceedence was noted at the permanent monitor.

  .  - When concentrations exceeded the standard at the permanent monitor
      they were also exceeded at other locations.

4.  Changes in CO concentrations at outdoor sites frequently coincided with
    changes in CO concentrations at indoor sites, but the relationship be-
    tween indoor and outdoor values was not constant.

    - Concentrations were usually lower indoors than at the adjacent outdoor
      site.

    - Indoors, the eight-hour average concentration of carbon monoxide ex-
      ceeded 9.0 ppm at times.
                                     - 5 -

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5.  Pedestrians were exposed to eight-hour average CO concentrations  exceed-



    ing the standard at times.








    - For sampling periods between two to four hours, concentrations  ranged



      from 3.9 ppm to 14 ppm.








    — For nearly sequential sampling periods totalling seven or more  hours,



      averages were equal to or above 9.0 ppm on four days.







It is recommended that:








1.  The carbon monoxide problem in Boise be considered a widespread problem.








2.  Increased local source emissions be avoided in areas where violations



    have been observed unless a reduction in the background concentrations



    which is at least sufficient to offset the increase can be demonstrated.








3-  Concentrations at the permanent monitor above 9.0 ppm be considered as



    indicative of concentrations equally high and very likely higher  else-



    where in the study area.  (Note that concentrations at the permanent



    monitor below 9.0 ppm do not mean that air quality standards are  being



    met throughout the study area.)








4.  A site on Idaho Street (site 32 or 10A) be considered as a candidate



    site to represent carbon monoxide concentrations in downtown Boise for
                                     - 6 -

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    routine ambient air quality monitoring  or  for  short-term monitoring



    during the late fall and winter season,  (November-December).








5.  Planning for future studies to aid development of control strategies and



    track progress towards attainment of the standard should consider the



    need for related data on traffic and meteorological characteristics.







                               METHOD OF STUDY








Forty outdoor sites (Figure 1 and Table 1)  were  selected after a review of  '



traffic characteristics, potential population  exposure, and  planning for the



Boise downtown area.  Traffic volumes were  a significant factor in the  selec-



tion of many sites because the motor vehicle is  by far the major source of



carbon monoxide in Boise.  However, locations  where high CO  from idling



vehicles might occur in situations, such as entrances or exits from large



parking lots, were deliberately avoided.  At each site, the  sample inlet was



about 3J meters above the sidewalk, more than  10 meters from an intersection,



and more than 2 meters from a vertical wall.   Most samples were a little



over one meter from the street curb; two were  at much greater distances.








Each week-day, air was collected into a bag during two sequential periods



(about 10:00 a.m. to 2:00 p.m. and about 2:00  p.m. to 6:00 p.m.) so that an




eight-hour average could be calculated for  comparison with the national




ambient air quality standard of 9.0 ppm which  is not to be exceeded more
                                      -  7  -

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than once per year.  Samples were obtained during November 25 through Decem-



ber 22, 1977, on week-days from about 10:00 a.m. to 6:00 p.m. because this



period of the day seemed most likely to have high carbon monoxide levels



based on data from the permanent monitor (Figure 2).  This appeared to  be




true during the survey since the daily maximum eight-hour average at the



state site was within 1 ppm of the 10:00 a.m. to 6:00 p.m. average on all



but four days of the study.  Carbon monoxide in the study samples was ana-



lyzed by an electrochemical oxidation method. Continuous analysis of air at



the indoor sites (in addition to bag sampling indoors and at the adjacent



outdoor site) monitored the daily pattern of indoor carbon monoxide levels.








Indoor sites representing exposure situations in downtown buildings within a



few blocks of the permanent monitor included three small retail shops,  a



hotel, and a large department store.  A hospital site about 0.8 mile east of



the permanent monitor was also sampled.  At all locations, care was taken to



avoid non-vehicle sources of carbon monoxide such as tobacco smoke in the



immediate vicinity of the sampler or fuel combustion from building heating



systems.  The nearest adjacent outdoor site was the basis for comparison.








                            RESULTS AND DISCUSSION








Outdoor Sites



The relative severity of the carbon monoxide problem at various outdoor



sites during the selected time period is indicated by several measures.



Maximum and second-highest eight-hour averages, the frequency of exceedences




observed at each site and maximum four-hour AM (10:00 a.m. to 2:00 p.m.) and
                                     - 8 -

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 FIGURE 1
 Boise Carbon Monoxide Study
Location of EPA Sampling Sites
     11725/77 to 12/22/77

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Table 1.  BOISE CARBON MONOXIDE SAMPLING SITES




             11/25 to 12/22, 1977
SITE NO.
1
2
3
4
5
6
7
8
9
11
12
13
14
15
16
17
18
19
20
21
22
MAIN STREET
Broadway
Broadway
Capitol
Capitol
Capitol
8TH
8TH
Main
9TH
9TH
State
9TH
Main
Main
10TH
Idaho
Main
11TH
Main
13TH
Front
CROSS STREET
n/o Myrtle
n/o Broad
n/o College
n/o Broad
n/o Idaho
n/o Idaho
n/o Main
w/o 8TH
n/o Main
n/o Idaho
w/o 8TH
n/o Main
w/o 9TH
w/o 9th
n/o Idaho
w/o 10th
w/o 10th
n/o Main
w/o 11th
n/o Idaho
w/o 15th
SIDE OF STREET
W
E
E
W
W
E
E
N
E
E
S
W
N
S
W
S
N
W
S
E
N
                      - 10 -

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            Table 1 (cont'd).  BOISE CARBON MONOXIDE SAMPLING SITES




                               11/25 to 12/22,  1977
SITE NO.   MAIN STREET
CROSS STREET
SIDE OF STREET
23
24
25
26
32
10A
27A
27B
28A
28B
29A
29B
30A
30B
3U
31B
32B
33A
33B
Main
16TH
23RD
State
Idaho
Idaho
Capitol
13TH
Main
16TH
1ST
State
Capitol
State
Capital
15TH
16TH
9TH
Grove
                                w/o  15TH



                                n/o  Main



                                n/o  Fairview



                                w/o  22nd



                                w/o  8TH



                                w/o  8TH



                                n/o  College*



                                n/o  State



                                w/o  Broadway



                                n/o  State



                                n/o  Idaho



                                w/o  18TH



                                n/o  Myrtle



                                w/o  25TH




                                n/o  Main



                                n/o  Main



                                n/o  River Road



                                n/o  Main




                                w/o  11TH
                                   S




                                   W




                                   E




                                   N




                                   N




                                   S




                                   W




                                   E




                                   N




                                   E




                                   W




                                   S




                                   E




                                   S




                                   W




                                   W




                                   W




                                   W




                                   N
*  Actually n/o Sherwood
                                      -  11  -

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      Figure 2




Boise Carbon Monoxide

State Site* Data Summary

For the November - December

Periods in 1975, 1976 and  1977
•Located til 115% N. 9th (Odd Fellows Building)
                                                  ——  1975 Data


                                                  — — —  1976 Data


                                                  ........  1977 Data
Figure

Time Distribution of 8-Hour Averages Over 9.0 ppm

During November - December

(By Ending Hour)
     SI
     Z o
     UJ I

     Q ^
     Ul 

Z 2 -D
  OLUi 0>
_ o ^
I- UJ ^
O'Q:O.
<  I'D

£*:£
  "J O)
  m:.E
     9t,
     O
            0.20
            o.io.
                                                              -r 0.20

                                                              + o.io
                     0200
                             0400
                                    0600
0800
       1000    1200     1400     1600     1800     2000
                                                                                              2200     2400
                                                     ENDING HOUR

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PM (2:00 p.m. to 6:00 p.m.) averages  in  Table  2  may be  compared  with measured



values at the state site.  Data distributions  for  each  site's  eight-hour



(10:00 a.m. to 6:00 p.m.) averages may be  compared in Figure 3.   Figures 4,



5, and 6 illustrate the spatial variation  of the data in Table 2 on  maps of



Boise.








In general, the lowest values  occurred at  site 3 on the Boise  State  Univer-



sity campus which was the farthest from  any  roadway (about  192 feet  east of



Capitol Boulevard).  The nearest  roadway's contribution may have been rela-



tively less here and thus more indicative  of the varying background  level of



carbon monoxide.








Depending on the purpose of the analysis,  different measures are appropriate



for examination of the representativeness  of the existing permanent  monitor.



Day-by-day similarities are not required to  compare the necessary reduction



of carbon monoxide levels implied by  data  from two different sites.   The



relationships between data at  the state  site and at other sites  are  not



necessarily the same from day-to-day.  Because attainment of the national



ambient air quality standard will depend on  developing  and  carrying  out



plans to reduce existing CO levels, it is  useful to know whether or  not  the



higher CO levels are similar at sites when measurements are taken over an



extended period.  Therefore, the  maximum eight-hour average concentration



and the frequency with which it exceeded the 9.0 ppm standard  at each site




are appropriate measures for comparison.
                                      - 13 -

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Table 2.  Maximum Values from Forty Sites and the Permanent Monitor
                       Carbon Monoxide in ppm
Site
1
2
3
4
5
6
7
8
9
1 10 A*
| — i
11
i
12
13
.14
15
16
17
18
19
20
21
22
23
Maximum AM
10 AM-2 PM
12.9
10.9
5.0
9.0
11.5
11.0
9.2
12.0
14.2
13.5
13.2
6.3
15.1
12.1
8.0
10.0
13.9
15.6
11.3
16.5
9.0
10.2
14.1
Maximum PM
2 PM-6 PM
16.5
8.9
4.5
10.0
15.5
11.0
12.8
16.0
13.3
20.6
18.0
12.9
15.2
11.5
7.5
14.0
16.5
14.9
13.1
13.5
11.2
12.0
11.8
Maximum AVC
10 AM-6 PM
14.7
9.0
4.8
9.5
13.5
10.5
8.4
13.0
13.6
15.9
15.6
9.5
14.2
11.2
7.6
9.9
15.2
15.3
12.1
13.8
9.9
11.1
13.0
% AVC1
GT 9.0
60
0
0
5
15
10
0
8
35
50
44
6
56
6
0
11
19
37
25
37
5
10
18
Ratio2
1.4
1.0
0.5
0.9
1.3
1.0
0.8
1.5
1.3
1.5
1.5
0.9
1.0
1.3
0.6
0.9
1.5
1.5
1.2
1.3
0.9
1.1
—
Date of
Maximum AVC
12/02
11/25
11/25
12/02
12/02
12/02
11/30
11/25
12/02
12/02
12/02
12/02
12/22
11/25
12/22
12/02
12/02
12/02
12/02
12/02
12/02
12/02
12/01
Second-Hi
AVC
12.6
7.7
4.2
6.9
11.8
9.4
8.1
9.0
11.9
13.2
13.3
8.6
12.4
7.9
7.5
9.4
13.6
12.1
10.2
11.5
8.4
9.1
11.6
Second
Ratio3
0.9
0,6
0.4
1.3
0.9
1.5
1.6
0.7
1.9
1.3
2.2
1.0
1.1
0.7
0.7
0.7
1.5
1.4
1.2
1.9
—
1.0
1.1
Date of
Second-Hi
12/22
12/22
12/02
12/12
12/22
12/06
12/12
12/22
12/06
12/05
12/06
1 1/25
12/19
12/02
11/30
12/22
11/25
11/25
11/25
12/06
12/01
11/25
12/02

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Site
24
25
26
27 A*
27B**
28A
28B
29A
29B
30 A
30B
31A
31B
32
32B
33A
33B
ODD***
Maximum AM
10 AM-2 PM
12.6
11.0
8.1
10.1
4.7
10.0
9.0
9.0
7.0
11.2
8.0
9.9
7.1
15.2
10.3
10.5
7.0
12.4
Maximum PM
2 PM-6 PM
17.5
15.8
14.0
10.1
6.5
9.9
9.3
9.9
4.5
12.0
5.7
10.5
6.5
19.9
9.1
13.3
10.1
15.1
Maximum AVC
10 AM-6 PM
15.1
13.4
10.6
10.1
5.3
8.0
7.8
9.5
5.4
11.4
6.0
8.7
6.3
17.2
9.7
11.6
8.4
13.7
Table 2. (con
% AVC1
GT 9.0 Ratio2
10
11
5
10
0
0
0
10
0
30
0
0
0
70
14
50
0
47
1.4
1.3
1.0
1.0
0.4
0.8
0.6
0.9
1.0
1.1
1.5
0.9
0.5
1.3
1.9
1.1
2.1
—
•t)
Date of
Maximum AVC
12/02
12/02
12/02
12/02
12/22
12/02
12/22
12/02
12/12
12/02
12/14
11/28
12/22
12/22
12/12
11/30
12/14
12/22
Second-Hi
AVC
9.1
11.0
8.6
7.2
4.1
8.0
6.4
8.5
4,9
11.0
4.6
7.7
5.7
16.5
8.1
10.6
7.2
10.8
i
Second
Ratio3
1.5
1.8
1.0
1.2
0.4
0.8
1.6
1.4
0.4
1.2
0.9
0,7
1.1
1.6
0.6
1.1
1.7
—
Date of
Second-Hi
12/06
12/06
11/25
12/06
12/21
12/02
12/14
12/06
12/22
11/25
12/12
12/02
12/12
12/02
12/22
12/05
12/20
12/19
  * "A" suffix indicates  sampled  first  10  days.
 ** "B" suffix indicates  sampled  last  10 days.
*** State's permanent monitor  at  Odd Fellows  Hall,  115^  Ninth  Street.
 1  Frequency of AVC's exceeding  9  ppm, expressed  as  a percentage  of  the  number  of  samples,
 2  Ratio of maximum AVC  to  the eight-hour average  for the  same  time  at ..the  State site,
 3  Ratio of second-highest  AVC to  the  eight-hour  average for  the  same time  at the  St,ate  site.

-------
Boise Carbon Monoxide
November 25 to December 22, 1977
(Weekdays Only)
Figure 3
Characteristics of Weekday Carbon Monoxide Average Concentrations for
an Eight-Hour Period (10:00 A.M. to 6:00 P.M.) at Each Site.
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-------
                                                                                                   A
                                                                                    Maximum
                                                                                    2nd highest
                                                                                    Mean + one standard deviation
                                                                                    Median
                                                                                    Mean
                                                                                    Mean - one standard deviation
                                                                                    Minimum
                                                                                    Standard not to be exceeded
                                                                                    more than once per year
                                                                                                          • Sites - first 10 days
                                                                                                         *• Sites - last 10 days
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      21    22     23    24     25     26    27A'   27B"  28A-  28B**   29A*  29B'   30A*   30B*   31A«  31B**  32   32B**   33A'  33B**  ODD
                                                                                                                            Permanent Monitor
    /    t    i    /   y   *?    /   /   /   /  /    /   /   /   /    /  /    ?#   /   /   /
    •*     O     r»      —    in     f*     ~.     e*     r*    **.     ^           s.w.O      O^1     i-vOsT*

SITE  NUMBER
                                                                     3
                                                                                 3
^
                               CO
                                     c?
 .c
J?
                                                             $     -
                                                                 17
                                                                           Note: Number of successful samples varies from site to site

-------
10 Scale in PPM CO
          FIGURE 4
          CARBON MONOXIDE
           CONCENTRATIONS
             11/25/77 to 12/22/77
BOISE CENTRAL BUSINESS DISTRICT
    MAXIMUM 8-HOUR1 VALUES FOR ENTIRE
    SAMPLING INTERVAL
Q Denotes 20-Day Sites (11/25/77)
| Denotes First 10-Day Sites (11/25/77-12/8/77)
I Denotes Last 10-Day Sites (12/9/77 - 12/22/77)

I Black Denotes Values Greater than 9 PPM CO
                                 AM TO 6 PM

-------
                                                 FIGURE 5
- 100 Scale %
                                                  CARBON MONOXIDE
                                                   CONCENTRATIONS
                                    st.              11/25/77 to 12/22/77
                              BA^°C*    BOISE CENTRAL BUSINESS  DISTRICT
                                    ST
                                         FREQUENCY1 OF 8-HOUR2 VALUES GREATER
                                      ST  THAN 9.0 PPM
                                                             •%
                                                                          *
                                                                           ^
U Denotes 20-Day Sites (11/25/77 - 12/22/77)

 I Denotes First 10-Day Sites (11/25/77-12/8/77)

I Denotes Last 10-Day Sites (12/9/77 - 12/22/77)

| Black Denotes Frequencies Greater than 25%
                                                            'ROUNDED TO NEAREST 5%
                                                            210 AM TO 6 PM

-------
On 95% of the study days, the eight-hour standard was exceeded at one or


more sites.  Several of the study sites experienced at least one eight-hour


average for 10:00 a.m. to 6:00 p.m. that was higher than the highest observed


at the state site during the survey period (13.7 ppm).  These included sites


1, 10A, 11, 13, 17, 18, 20, 2H, and 32 with the highest, 17.2 ppm, at site


32 on Idaho west of Eighth Street (Figures 3 and 4).  Site 32, which is a


block from the permanent monitorr had the most frequent exceedences of the


9.0 ppm standard (70$ of the sampled days) and most often had the highest


8-hour average of all sites (on nine days of the 20-day sample period).






Figure 5 shows that about 70* of the sampling sites (28 out of HO) experi-


enced one or more days when the eight-hour average exceeded the 9.0 ppm


standard.  The frequency of exceedences for several study sites was greater



than for the permanent monitor (47/8).  With the exception of Site 1 on Broad-


way north of Myrtle, these sites were within a couple of blocks of the exist-



ing monitor.






Figure 6 shows the second-highest eight-hour average at each site.  During


the study period, the maximum second-highest AVC recorded for any site,


16.5 ppm at site 32, exceeded the second-highest eight-hour average for


10:00 a.m. to 6:00 p.m. at the permanent monitor, 10.8 ppm.  Nineteen sites
                                                               /

experienced at least two days with an eight-hour period averaging above the



standard.  These were widespread through the study area and included sites


on Broadway north of Myrtle; several blocks between Idaho and Main (on 9th,



11th, and 16th); several blocks north of Idaho (on 8th, 9th, and 10th); both
                                     - 20 -

-------
                                                 FIGURE 6
-10
    Scale in PPM CO
          CARBON MONOXIDE
           CONCENTRATIONS
             11725/77 to 12/22/77

BOISE CENTRAL  BUSINESS  DISTRICT
    SECOND HIGHEST 8-HOUR1 VALUES FOR
    ENTIRE SAMPLING INTERVAL
 | Denotes 20-Day Sites (11/25/77 - 12/22/77)

 I Denotes First 10-Day Sites (11/25/77-12/8/77)

| Denotes Last 10-Day Sites (12/9/77 - 12/22/77)

 I Black Denotes Values Greater than 9 PPM CO
                              '10 AM TO 6 PM

-------
blocks sampled on Idaho (west of 8th and 10th); several  blocks  on Main (west



of 10th, 11th, and 15th); Front west of 15th; Capitol north  of  Myrtle and



Idaho; and 23rd north of Fairview.  Undetected violations may have occurred



at other sites or with greater magnitude at these same sites during the days



of the study.








On the day of the highest composite average of eight-hour values  from all



sites, December 2, most sites experienced their highest  concentrations.   The



10:00 a.m. to 6:00 p.m. average carbon monoxide concentration for  each out-



door study site on this day (Figure 7) shows that high concentrations  were



not restricted to a few sites, but were widespread with  twenty-four of the



twenty-nine sampled sites experiencing concentrations above  9.0 ppm.   Eleven



of the sites had eight-hour concentrations more than 20? higher than the



state site's (10.5 ppm).  Fourteen sites had averages similar to the state



site (ratios greater than or equal to 0.8 but less than  or equal to  1.2);



only four sites had appreciably lower averages (ratios less  than 0.8).








On some days at one or more study sites, a concentration above 9.0 ppm and



up to twice the concentration at the permanent monitor was noted when  con-



centrations at the permanent monitor were below the standard (Figure 8).



However, a concentration above 9.0 ppm at the permanent monitor was  usually



accompanied by equally high or higher concentrations elsewhere.   The concen-



tration at the permanent monitor was higher than at any  other site on  only



one day of the study (Table 3).
                                     - 22 -

-------
r10
-0
    Scale in PPM CO
* No monitoring data for these sites this date
          FIGURE 7
          CARBON MONOXIDE
           CONCENTRATIONS
             11/25/77 to 12/22/77
BOISE CENTRAL BUSINESS DISTRICT
  DAY1 OF HIGHEST AVERAGE OVER ALL SITES

  Denotes 20-Day Sites (11/25/77 - 12/22/77)

I  Denotes First 10-Day Sites (11/25/77-12/8/77)

I  Denotes Last 10-Day Sites (12/9/77 - 12/22/77)

  Black Denotes Values Greater than 9 PPM CO
                                 AM TO 6 PM
                                        12/2/77

-------
  FIGURE 8
 Boise Carbon Monoxide
 November 25 to December 22, 1977
 Characteristics by Day of the Composite Range of Carbon Monoxide
 Concentrations for all Sites During an Eight-Hour Period.
 (10A.M. to 6 P.M.)
                                                            A
                                                                  Maximum



                                                                  Mean +. one standard deviation

                                                                  Median
                                                                                          T
                                                                - Mean - one standard deviation

                                                                - Minimum

                                                                ~l Permanent Monitor
      20.0 T-
N>

      15.0 - -
  Op
  ||,0.0
  oz

  El
     o
     o
CO
       5.0 - -
i


1
              TT
          W
I
                                                           T
                                                o
                            T
                                                    T
r


 \
   J,         /
  /;.    I    J'
 / *'
 »rH      s
 •    *   i   «• • i
/    ; _L  /P
                                                    T

               11/25 11/28 11/29  11/30  12/1   12/2   12/5   12/6  12/7   12/8  12/9  12/12  12/13 12/14 12/15 12/16  12/19  12/20 12/21  12/22

-------
       Comparison of Maximum Study Site Each Day  and  Permanent  Monitor
                             Eight-Hour Averages
                            (carbon monoxide in  ppm)
                 STUDY SITES
Maximum
Study Site
32
32
1
33A
23
32
10A
11
32
13
32
1
11
11
32
32
13
20 and 11
32
32
Maximum
AVC»
16.2
11.3
11.0
11.6
13.0
16.5
13-2
13.3
8.7
9.4
12.1
11.1
9.8
11.9
9.9
11.0
12.4
10.1
12.6
17.2
Ratio
AVC/AVS«»
1.8
1.2
1.3
1.1
_
1.6
1.3
2.2
1.4
1.2
1.2
2.1
7.8
3.0
.9
1.8
1.1
2.4
1.2
1.3
    PERMANENT MONITOR
                                                 AVS«»«

                                                 8.8
                                                 9.8
                                                 8.3
                                                 10.7

                                                 10.5
                                                 9.9   •
                                                 6.2
                                                 6.4
                                                 7.6
                                                 9.7
                                                 5.2
                                                 1.3
                                                 4.0
                                                 10.7
                                                 6.0
                                                 10.8
                                                 4.
                                                 10,
 1
.2
 Maximum
Eight-Hour

 9.3
10.7
 8.3
10.7

10.5
 9.9
 6.2
 7.4
 8.2
 9.7
 8.4
 2.8
 4.0
10.7
 6.4
12.0
 7,
10.
 1
.5
                                                 13.7
         13.7
  End
 Hour

1500
1600
1800
1800

1800
1900
1800
1500
2000
1800
1500
0100
1800
1800
1500
1900
1400
2000
1900
  *  Eight-hour average CO concentration for 10:00 a.m. - 6:00 p.m.  (1000 -
     1800) at a study site

 **  Ratio AVC/AVS - The ratio of the eight-hour average CO concentration at
     the study site to that at the permanent monitor on the same day for the
     10:00 a.m. - 6:00 p.m. period.

**•  Eight-hour average CO concentration for 10:00 a.m. - 6:00 p.m. at the
     permanent monitor operated by the State at 115J Ninth Street.
                                     - 25 -

-------
The study ended on Thursday, December 22, the day before the highest  eight-hour



average for 1977 was recorded at the permanent monitor - 18.5 ppm  ending at



6:00 p.m.  Based on data collected during the study, it seems highly  likely



that concentrations greater than this occurred at one or more study sites on



Friday, December 23.








Indoor Sites








At all six indoor sites, the concentrations were usually less than at the



adjacent outdoor sites.  Otherwise, no consistent relationship between indoor



and outdoor levels was noted in this limited study.  Nevertheless, the eight-



hour average concentrations on one or more days exceeded 9.0 ppm at four of



the indoor locations with maximum values ranging from 10.0 to 11.1 ppm.   At



several sites, late afternoon increases in indoor CO were observed, suggesting



an influence from the afternoon peak traffic.








Pedestrian Data








Sampling periods ranged in length from about two to four hours on  two routes



which varied from day to day.  For these samples, concentrations ranged from



3.9 ppm to 14 ppm.  On four days, the average of morning and afternoon samples



totalling about seven or more hours was equal to or above 9.0 ppm.








Correlations were examined between concentrations on Route A and those on



Route B and were surprisingly high.  Better correlations were found between



the different routes on the same day than between morning and afternoon samples



from the same route.





                                     - 26 -

-------
                                     TECHNICAL REPORT DATA
                              (Please read Instructions on the reverse before completing)
1. REPORT NO.
  EPA 910/9-78-055a
              3. RECIPIENT'S ACCESSIOWNO.
4. TITLE AND SUBTITLE
   Carbon Monoxide Study - Boise,  Idaho
   Executive  Summary
   November 25  - December 22, 1977
              5. REPORT DATE
                December 1978
              6. PERFORMING ORGANIZATION CODE
 '. AUTHOR(S)
                                                               8. PERFORMING ORGANIZATION REPORT NO.
   C.  B. Wilson and J.  W.  Schweiss
9. PERFORMING ORGANIZATION NAME AND ADDRESS
  U.S. Environmental  Protection Agency
  Region 10,  Surveillance and Analysis Division
  1200 Sixth  Avenue
  Seattle, Washington  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

   See also  EPA 910/9-78-055b
 16. ABSTRACT
   This report is a  summary of  EPA 910/9-78-055b, a  study of the carbon monoxide
   problem  in Boise.
17.
                                  KEY WORDS AND DOCUMENT ANALYSIS
                   DESCRIPTORS
                                                 b.IDENTIFIERS/OPEN ENDED TERMS
                            c.  COSATI Field/Group
   carbon monoxide
   air quality data
   air pollution sampling
  Boise  (Idaho)
13. DISTRIBUTION STATEMENT

   Unlimited
19. SECURITY CLASS (This Report)
   unclassified
21. NO. OF PAGES
     35
                                                 20. SECURITY CLASS (This page)

                                                    unclassified
                            22. PRICE
EPA Form 2220-1 (9-73)

-------