United States
Environmental Protection
Agency
Air Pollution Training Institute
MD20
Environmental Research Center
Research Triangle Park, NC 27711
EPA 450/2-82-002
February, 1982
APTI
Correspondence Course 437
Site Selection
for the Monitoring of CO
and Photochemical Pollutants
in Ambient Air
Guidebook
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United States Air Pollution Training Institute EPA 450/2-82-002
Environmental Protection MD 20 February, 1982
Agency Environmental Research Center
Research Triangle Park, NC 27711
Air
APTI
Correspondence Course 437
Site Selection
for the Monitoring of CO
and Photochemical Pollutants
in Ambient Air
Guidebook
Technical Content:
B. M. Ray
Instructional Design:
K. M. Leslie
Northrop Services, Inc.
P.O. Box 12313
Research Triangle Park, NC 27709
Under Contract No.
68-02-3573
EPA Project Officer
R. E. Townsend
United States Environmental Protection Agency
Office of Air, Noise, and Radiation
Office of Air Quality Planningand Standards
Research Triangle Park, NC 27711
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Notice
This is not an official policy and standards document. The opinions and selections
are those of the authors and not necessarily those of the Environmental Protection
Agency. Every attempt has been made to represent the present state of the art as
well as subject areas still under evaluation. Any mention of products or organiza-
tions does not constitute endorsement by the United States Environmental Protec-
tion Agency.
Availability
This document is issued by the Manpower and Technical Information Branch,
Control Programs Development Division, Office of Air Quality Planning and Stan-
dards, USEPA. It was developed for use in training courses presented by the EPA
Air Pollution Training Institute and others receiving contractual or grant support
from the Institute. Other organizations are welcome to use the document.
This publication is available, free of charge, to schools or governmental air
pollution control agencies intending to conduct a training course on the subject
covered. Submit a written request to the Air Pollution Training Institute, USEPA,
MD 20, Research Triangle Park, NC 27711.
Others may obtain copies, for a fee, from the National Technical Information
Service (NTIS), 5825 Port Royal Road. Springfield, VA 22161.
n
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Table of Contents
Page
Course Introduction 0-1
Section 1. Introduction to CO Monitoring and to Site Selection for
Regional and Neighborhood CO Monitoring Stations 1-1
Review Exercise 1-3
Review Exercise Answers 1-7
Section 2. The Locating of Middle Scale CO Monitoring Stations and
the Rationale for CO Monitor-Siting Criteria 2-1
Review Exercise 2-3
Review Exercise Answers 2-9
Section 3. Introduction to the Monitoring of Photochemical Air
Pollutants 3-1
Review Exercise 3-3
Review Exercise Answers 3-8
Section 4. Locating Monitoring Stations for Photochemical Air
Pollutants 4-1
Review Exercise 4-3
Review Exercise Answers 4-14
Section 5. Rationale for Monitor-Siting Criteria for Photochemical
Air Pollutants 5-1
Review Exercise 5-3
Review Exercise Answers 5-6
Section 6. Monitoring Network Design and Probe-Siting Criteria for
SLAMS, NAMS, and PSD Monitoring Stations for
CO, O8, and NO, 6-1
Excerpts of 40 CFR 58 Appendices D and E 6-4
Excerpts of "Ambient Monitoring Guidelines for Prevention of
Significant Deterioration (PSD)" 6-12
Review Exercise 6-17
Review Exercise Answers 6-25
111
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Course Introduction
Overview of Course
Course Description
This training course is a 35-hour correspondence course dealing with the siting of
ambient monitors for CO, nonmethane hydrocarbons, NO, NO2, and ozone. The
course presents general concepts of ambient monitor site selection and specific,
detailed considerations and procedures for selecting CO, nonmethane hydro-
carbons, NO, NO2, and ozone ambient monitoring sites. Course topics include the
following:
• use of monitoring data and related monitor-siting objectives
• special considerations associated with the monitoring of CO, nonmethane
hydrocarbons, NO, NO2, and ozone
• procedures and criteria for site selection for the monitoring of CO,
nonmethane hydrocarbons, NO, NO2, and ozone
• rationale for siting criteria associated with the monitoring of CO, nonmethane
hydrocarbons, NO, NO2, and ozone
• network design and probe-siting criteria for CO, NO2, and ozone SLAMS,
NAMS, and PSD monitoring stations.
Course Goal
The goal of this course is to familiarize you with general concepts of ambient
monitor site selection and with specific, detailed considerations and procedures for
selecting ambient monitor sites for the monitoring of CO, nonmethane hydro-
carbons, NO, NO2, and ozone.
Course Objectives
Upon completion of this course, you should be able to:
1. describe general considerations for siting ambient air quality monitors.
2. select the optimum general siting area and probe location for CO,
nonmethane hydrocarbons, NO, NO2, and ozone monitors for a given
monitoring objective.
3. describe the logic of the siting criteria for the monitoring of CO, nonmethane
hydrocarbons, NO, NO2, and ozone.
0-1
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Lesson Titles, Sequence, and Trainee Involvement Time
Trainee involvement
Lesson number Lesson title time (hours)
1 Introduction to CO Monitoring and 5
to Site Selection for Regional and
Neighborhood CO Monitoring
Stations
2 The Locating of Middle Scale CO 5
Monitoring Stations and the
Rationale for CO Monitor-Siting
Criteria
3 Introduction to the Monitoring of 6
Photochemical Air Pollutants
4 Locating Monitoring Stations for 8
Photochemical Air Pollutants
5 Rationale for Monitor-Siting Criteria 6
for Photochemical Air Pollutants
6 Monitoring Network Design and 5
Probe-Siting Criteria for SLAMS,
NAMS, and PSD Monitoring Sta-
tions for CO, OS) and NO2
Requirements for Successful Completion of this Course
In order to receive 3.5 Continuing Education Units (CEUs) and a certificate of
course completion you must:
• take two supervised quizzes and a supervised final examination.
• achieve a final course grade of at least 70% (out of 100%) determined as
follows:
• 20% from Quiz 1
• 20% from Quiz 2
• 60% from the final examination.
0-2
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Use of Course Materials
Necessary Materials
• "APTI Correspondence Course 437 Site Selection for the Monitoring of CO
and Photochemical Pollutants in Ambient Air: Guidebook"
• EPA 450/3-75-077, "Selecting Sites for Carbon Monoxide Monitoring"
• EPA 450/3-78-013, "Site Selection for the Monitoring of Photochemical
Air Pollutants"
• ruler
• pencil or pen
Use of this Guidebook
Relationship Between Guidebook and Assigned Reading Materials
This guidebook directs your progress through the reference texts "Selecting Sites for
Carbon Monoxide Monitoring" and "Site Selection for the Monitoring of
Photochemical Air Pollutants" and through the excerpts of 40 CFR 58 Appendices
D and E and "Ambient Monitoring Guidelines for Prevention of Significant
Deterioration (PSD)", which are contained in the guidebook.
Description of Guidebook Sections
This guidebook contains six reading assignment sections which correspond to the
six lessons of the course.
Each section contains the following:
• reading assignment
• reading assignment topics
• section's learning goal and objectives
• reading guidance
• review exercise
Instructions for Completing the Quizzes and the Final Examination
• You should have received, along with this guidebook, a separate sealed
envelope containing two quizzes and a final examination.
• You must arrange to have someone serve as your test supervisor.
• You must give the sealed envelope containing the quizzes and Final examina-
tion to your test supervisor.
• At designated times during the course, under the supervision of your test
supervisor, complete the quizzes and the final exam.
0-3
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• After you have completed each quiz or the exam, your test supervisor must
sign a statement on the quiz/exam answer sheet certifying that the quiz/exam
was administered in accordance with the specified test instructions.
• After signing the quiz/exam answer sheet, your test supervisor must mail the
quiz/exam and its answer sheet to the following address:
Air Pollution Training Institute
Environmental Research Center
MD-20
Research Triangle Park, NC 27711
• After completing a quiz, continue with the course. Do not wait for quiz
results.
• Quiz/exam and course grade results will be mailed to you.
// you have questions, contact:
Air Pollution Training Institute
Environmental Research Center
MD-20
Research Triangle Park, NC 27711
Telephone numbers:
Commercial: (919) 541-2401
FTS: 629-2401
0-4
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Section 1
Introduction to CO Monitoring and
to Site Selection for Regional and
Neighborhood CO Monitoring Stations
Reading Assignment
Pages 1-35 of EPA 450/3-75-077 "Selecting Sites for Carbon Monoxide
Monitoring".
Reading Assignment Topics
Need for objective, uniform siting procedures
General emission characteristics of CO sources
Uses of CO monitoring data
Spatial scales of representativeness
Correlation of spatial scales of representativeness with uses of monitoring data
Locating regional CO monitoring stations
Locating neighborhood CO monitoring stations
Learning Goal and Objectives
Learning Goal
To familiarize you with major sources of CO emissions, general types of monitoring
sites used to measure ambient CO concentrations, and siting of regional and
neighborhood CO monitoring stations.
Learning Objectives
When you have completed this section, you should be able to:
1. recognize transportation activities, especially the use of motor vehicles, as a
major source of CO emissions in the U.S.
2. describe typical concentration patterns of CO emissions from motor vehicles.
3. define spatial scale of representativeness.
4. associate typical spatial scales of representativeness with physical dimensions
of siting areas.
5. associate spatial scales of representativeness with uses of CO monitoring data.
6. select the general siting area for regional mean CO monitoring stations.
7. select the general siting area for regional background CO monitoring stations.
8. select the general siting area for neighborhood CO monitoring stations.
1-1
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Reading Guidance
• Because "Selecting Sites for Carbon Monoxide Monitoring" was published
before the promulgation of 40 CFR 58, the monitor probe heights and
roadway minimum separation distances for neighborhood stations specified in
the document do not agree with the required probe heights and separation
distances of 40 CFR 58. Also these differences are due to the less restrictive
monitoring objectives and practical siting problems encountered in the
40 CFR 58 regulations. Probe heights and roadway minimum separation
distances specified in 40 CFR 58 are addressed in Section 6 of this guidebook.
• Wind roses are discussed in this reading assignment. A wind rose is a graphical
representation of wind directional frequency. The farther the bar extends from
the circle, the more frequently the wind blows from that direction.
• The term sink is mentioned in this reading assignment. For our purposes, sink
is defined as an entity that destroys the pollutant that is being monitored.
• Refer often to the tables and figures of the assigned reading material as you
progress through the assignment.
• When you have finished the reading assignment, complete the review exercise
for Section 1. It begins on the following page.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), proceed to Section 2
of this guidebook.
1-2
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Review Exercise
Now that you've completed the assignment for Section 1, please answer the fol-
lowing questions. These will help you determine whether or not you are mastering
the material.
1. In the United States, transportation activities account for about
percent of atmospheric CO, with motor vehicles accounting for about
y) percent.
a. 50, 40
b. 30, 25
c. 75, 65
d. 95, 90
2. True or False? CO emissions from motor vehicles may result in large horizontal
and vertical concentration gradients.
3. True or False? A spatial scale of representativeness is the volume of air sur-
rounding an air monitoring site which can be described by measurements
made at the site.
Match each of the following spatial scales of representativeness with its corre-
sponding dimensions. (Questions 4-8)
4. microscale a. tens to hundreds of meters
5. middle scale b. hundreds of kilometers
6. neighborhood scale c. meters to a few tens of meters
7. urban scale d. entire metropolitan area
8. regional scale e. a few kilometers
Match each of the following CO monitoring data uses with its appropriate scales of
representativeness. (Questions 9-13)
9. determine compliance with a. middle/neighborhood scales
ambient air quality standards
10. alert authorities to existing b. neighborhood scale
or impending critical situations
11. evaluate results of control c. middle/regional scales
measures
12. serve as a data base for
city and regional planners
13. provide measures of the
magnitude of sources
and sinks
1-3
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14. Which of the four general siting areas, labeled a through d, is the best siting
area for a CO regional mean concentration monitoring station?
Wind rose
Major highway
Urban area
0 25 50
Kilometers
1-4
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15. Which of the four general siting areas, labeled a through d, is the best siting
area for locating a regional monitoring station for assessing the transport of
CO into the urban area?
Wind rose
Urban area
16. Which of the four general siting areas, labeled a through d in question 15, is
the best siting area for locating a second regional monitoring station for
assessing the transport of CO into the urban area?
1-5
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17. The figure below represents an urban area with relative CO concentrations
plotted. Which of the four general siting areas, labeled a through d, is the best
siting area for assessing CO concentrations in neighborhoods that have average
CO concentrations in the urban area?
18. Which of the four general siting areas, labeled a through d in question 17, is
the best siting area for assessing CO concentrations in neighborhoods that have
the highest CO concentrations in the urban area?
1-6
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Review Exercise Answers
Page(s) of CO
Siting Manual
1. c 3
2. True 4-5
3. True 9
4. c 9
5. a 10
6. e 10
7. d 11
8. b 11
9. a 16
10. a 16
11. a 16
12. b 17
13. c 17
14. d 22,27-28
15. a 22,27
16. c 22,27,29
17. c 32-33
18. a 32-33
1-7
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Section 2
The Locating of Middle Scale
CO Monitoring Stations and the
Rationale for CO Monitor-Siting Criteria
Reading Assignment
Pages 35-73 of EPA 450/3-75-077 "Selecting Sites for Carbon Monoxide
Monitoring".
Reading Assignment Topics
Types of middle scale CO monitoring stations
Locating street canyon CO monitoring stations
Locating roadway CO monitoring stations
Monitoring CO concentrations in the vicinity of an indirect source
CO monitoring stations other than regional, neighborhood, and middle scale
Considerations in locating probe inlets of CO monitors
Undue influence effects of nearby CO sources
Learning Goal and Objectives
Learning Goal
To familiarize you with the siting of middle scale CO monitoring stations and with
the logic of the CO monitor-siting criteria.
Learning Objectives
When you have completed this section, you should be able to:
1. select the general siting area for street canyon CO monitoring stations.
2. select the general siting area for roadway CO monitoring stations.
3. recognize the usefulness of weighted averages of CO measurements for
determining urban and national scale CO concentrations.
4. describe considerations and assumptions for determining probe-siting criteria
for CO analyzers located in street canyons.
5. describe assumptions for determining regional scale interference distances for
major highways and major urban areas.
6. describe the effects of nearby CO sources on CO measurements.
2-1
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Reading Guidance
• Because "Selecting Sites for Carbon Monoxide Monitoring" was published
before the promulgation of 40 CFR 58, the monitor probe heights and
roadway minimum separation distances for middle scale stations specified in
the document do not agree with the required probe heights and separation
distances of 40 CFR 58. Probe heights and roadway minimum separation
distances specified in 40 CFR 58 are addressed in Section 6 of this guidebook.
• Middle scale sites described in "Selecting Sites for Carbon Monoxide Moni-
toring" are approximately equivalent to microscale sites defined in 40 CFR 58.
• Try to visualize how the siting criteria would be affected if the assumptions
described in this reading assignment were altered.
• Refer often to the figures of the assigned reading material as you progress
through the assignment.
• When you have finished the reading assignment, complete the review exercise
for Section 2. It begins on the following page.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), take Quiz 1. Follow
the directions listed in the Course Introduction section of this guidebook.
• After completing Quiz 1, proceed to Section 3 of this guidebook.
2-2
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Review Exercise
Now that you've completed the assignment for Section 2, please answer the fol-
lowing questions. These will help you determine whether or not you are mastering
the material.
1. The figure below represents a downtown street canyon area with average daily
traffic volumes for major two-way streets indicated. Which of the four general
siting areas, labeled a through d, is the best siting area for locating a CO
monitor to measure the highest concentrations in the downtown area?
2-3
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2. The figure below represents a downtown street canyon area with average daily
traffic volumes indicated. Which of the four general siting areas, labeled a
through d, is the best siting area for locating a CO monitor to measure typical
concentrations in the downtown area?
Wind rose
for low
wind speeds
10,000
3. True or False? One sampling inlet is adequate for a street canyon CO monitor
that is located in an area of asymmetrical wind directional frequencies.
2-4
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4. The figure below represents a roadway area with average daily traffic volumes
indicated. Which of the four general siting areas, labeled a through d, is the
best siting area for locating a CO monitor to measure the highest concentra-
tions in the roadway area?
J
o
o
o
I
5,000
o
o
o
~1
10,000
r
Wind rose
for light winds
5. The figure below represents a roadway area with average daily traffic volumes
indicated. Which of the four general siting areas, labeled a through d, is the
best siting area for locating a CO monitor to measure typical concentrations in
the roadway area?
10,000
o
o
o
o
o
o
5,000
Wind rose
2-5
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6. True or False? When monitoring CO concentrations resulting from a roadway
in an area having wind directional frequencies that are asymmetrical, it is
desirable to locate sampling inlets on both sides of the roadway.
7. Which of the following is necessary for determining the general locations of
maximum CO concentrations resulting from an elevated roadway?
a. atmospheric stability class
b. wind direction
c. wind speed
d. CO emission rate of the roadway
e. all of the above
8. True or False? Short-term bag sampling is an efficient means of refining
general locations of maximum CO concentrations resulting from an elevated
roadway.
9. True or False? Simple averaging of CO concentrations from neighborhood
monitoring sites in an urban area is the best approach for determining urban
CO concentrations when no urban scale monitoring site exists.
10. True or False? Weighted averaging of CO concentrations from regional and
urban monitoring sites is a useful approach for determining national scale CO
concentrations.
11. Which of the following factors was (were) considered in selecting the optimum
probe height of 3 meters for CO monitors which are located in street canyons?
a. average breathing height
b. prevention of vandalism
c. a and b, above
d. none of the above
12. The recommended 1-meter probe height range for CO monitor probes which
are located in street canyons is based on the assumption that CO hourly
average concentrations in street canyons vary about (') PPm Per
meter.
a. 0.1
b. 1
c. 3
d. 5
2-6
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13. Which of the following factors was (were) considered in recommending that
street canyon CO monitor probes be located greater than 10 meters from an
intersection?
a. Intersections represent a much smaller portion of downtown space than do
the streets between them.
b. Pedestrian exposure times are probably greater in street canyons than at
intersections.
c. Practical difficulties of positioning probe inlets are less at midblock loca-
tions than at intersections.
d. Empirical data suggest that there is a reasonable uniformity of CO concen-
tration throughout the part of a block that is more than 10 meters from an
intersection.
e. all of the above
For questions 14 and 15, select the values that were assumed for each of the fol-
lowing parameters in determining the CO regional scale interference distance for
major highways.
14. Undue influence CO concentration level (mg/m3):
a. 0.01
b. 0.2
c. 1
d. 2
15. Peak CO emission rate of highway (g/m/s):
a. 0.001
b. 0.008
c. 0.08
d. 0.26
16. An extended straight section of a major highway has v) influence on
CO concentrations measured at regional monitoring sites which are aligned
within 5 degrees of it than(as) at regional monitoring sites which are outside
5-degree alignment.
a. more
b. less
c. the same
2-7
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For questions 17-21, select the values that were assumed for each of the following
parameters in determining the CO regional scale interference distance for major
urban areas.
17. Effective CO emission height (m):
a. 1
b. 5
c. 10
d. 20
18. Urban area maximum CO emission rate (g/m2/s):
a. 0.75XKT6
b. 0.86X10'5
c. 1.3X10-4
d. 2.4 xlO'3
19. Wind speed (m/s):
a. 0.1
b. 1
c. 10
d. 15
20. Atmospheric stability
a. unstable
b. slightly stable
c. stable
21. Undue influence CO concentration level (mg/ms):
a. 0.01
b. 0.2
c. 1
d. 2
22. In general, CO emissions from streets located in the center of a city have
v) influence on CO concentrations measured at street canyon
monitoring sites than(as) streets located at the edge of the city.
a. more
b. less
c. the same
23. Usually, emissions from sources located within 2 kilometers of a CO
neighborhood monitoring site account for v) percent of the CO con-
centrations measured at the site.
a. 5 to 10
b. 15 to 40
c. 50 to 75
d. 80 to 90
2-8
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Review Exercise Answers
Page(s) of CO
Siting Manual
1. d 38-39
2. a 38-40
3. False 39-40
4. d 42,44
5. b 42,44
6. True 42,44-45
7. e 46,48
8. True 45,46
9. False 51
10. True 53
11. c 55
12. b 56
13. e 60
14. b 63
15. b 63
16. a 63
17. c 65
18. c 64
19. b 64
20. b 65
21. b 64
22. b 66
23. b 69
2-9
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Section 3
Introduction to the Monitoring
of Photochemical Air Pollutants
Reading Assignment
Pages 7-23 of EPA 450/3-78-013 "Site Selection for the Monitoring of
Photochemical Air Pollutants".
Reading Assignment Topics
• Pollutants related to the formation of photochemical oxidants
• Emission sources and photochemical reactions of nonmethane hydrocarbons
• Emission sources and photochemical reactions of nitric oxide and nitrogen
dioxide
• Photochemical formation of ozone
• National Ambient Air Quality Standards (NAAQS) for the photochemical
pollutants
• Purposes of monitoring
• General types of monitoring sites
Learning Goal and Objectives
Learning Goal
To familiarize you with major sources of nonmethane hydrocarbons and nitrogen
oxide emissions, the photochemical formation of ozone, and general types of
monitoring sites used to measure nonmethane hydrocarbons, nitric oxide, nitrogen
dioxide, and ozone.
Learning Objectives
When you have completed this section, you should be able to:
1. recognize the major ambient air pollutants related to the formation of
photochemical oxidants.
2. explain why methane concentrations are not of concern when monitoring the
formation of photochemical oxidants.
3. recognize the use of motor vehicles and the use of organic solvents as major
sources of nonmethane hydrocarbon emissions in the U.S.
4. recognize stationary source combustion and transportation activities as
major sources of oxides of nitrogen emissions in the U.S.
3-1
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5. recognize nitric oxide and nitrogen dioxide as the major constituents
of the oxides of nitrogen.
6. recognize that nitric oxide is frequently oxidized to nitrogen dioxide.
7. describe the major chemical reactions of the atmospheric nitrogen dioxide
photolytic cycle.
8. recognize ozone as the major constituent of photochemical oxidants.
9. describe diurnal concentration patterns for ozone, nitric oxide, and nitrogen
dioxide.
10. recognize photochemical reactions of nonmethane hydrocarbons and oxides
of nitrogen as the major source of ozone.
11. recognize electrical discharges and stratospheric injection as minor sources of
ozone.
12. recognize the importance of the ratio of nonmethane hydrocarbon concen-
tration to oxides of nitrogen concentration for the formation of ozone.
13. recognize major purposes for monitoring nonmethane hydrocarbons, nitric
oxide, nitrogen dioxide, and ozone.
14. recognize neighborhood and urban/regional as important spatial scales of
representativeness for the monitoring of photochemical air pollutants.
15. differentiate between source-oriented and general monitoring sites.
16. differentiate between reactant-oriented and product-oriented monitoring
sites.
17. associate nonmethane hydrocarbons, nitric oxide, nitrogen dioxide, and
ozone with their appropriate general types of monitoring sites.
Reading Guidance
• Refer often to the tables and figures of the assigned reading material as you
progress through the assignment.
• The CO concentration curve depicted in Figure 6 on page 15 of the reading
assignment is a surrogate for nonmethane hydrocarbons concentration.
Because both CO and nonmethane hydrocarbons are emitted from motor
vehicles, nonmethane hydrocarbon concentration should increase during the
morning rush hours in the same manner as CO concentration.
• The NAAQS of 0.08 ppm for photochemical oxidants described in Table 4 on
page 17 of the reading assignment has been changed to 0.12 ppm for ozone.
• The averaging time for hydrocarbons indicated as 9 to 6 a.m. in Table 4 on
page 17 of the reading assignment should be 6 to 9 a.m.
• When you have finished the reading assignment, complete the review exercise
for Section 3. It begins on the following page.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), proceed to Section 4
of this guidebook.
3-2
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Review Exercise
Now that you've completed the assignment for Section 3, please answer :he fc
lowing questions. These will help you determine whether or not vou are :nastenne-
the material.
1. Which one of the following ambient air pollutants is not involved in the
formation of photochemical oxidants?
a. NMHC
b. NO,
c. NO
d. CO
2. True or False? Methane does not participate in the formation of photochemical
oxidants.
3. In the United States, transportation activities account for about ___iil___
percent of hydrocarbon emissions and the use of organic solvents accounts for
about v/ percent.
a. 40, 25
b. 60, 20
c. 40, 10
d. 60, 30
4. In the United States, stationary fuel combustion accounts for about
y) percent of NO* emissions and transportation activities account for
about v) percent.
a. 75, 20
b. 50, 45
c. 50, 20
d. 30, 10
5. Which of the following is(are) the major constituent(s) of NO,?
a. NO
b. NO2
c. a and b, above
d. none of the above
6. True or False? NO is frequently oxidized to form NO2.
3-3
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7. In the figure below, a, b, c, and d are
a. NO, O3, atomic oxygen, and hydrocarbons
b. O3, NO, atomic oxygen, and hydrocarbons
c. NO, atomic oxygen, O3, and hydrocarbons
d. O3, atomic oxygen, NO, and NO2
., respectively.
Hydrocarbon
free radicals A -" '
8. True or False? Photochemical oxidant concentrations are decreased when the
steady state of the NO2 photolytic cycle is disrupted by NMHC reacting with
NO to unbalance the cycle.
9.
is the major constituent of photochemical oxidants.
a. NO
b. NOZ
c. O,
d. none of the above
3-4
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10. In the figure below, curves labeled a, b, and c represent diurnal concentration
patterns for v) respectively.
a. NO, NO2, and O3
b. NO2, NO, and O3
c. O3, NO, and NO2
d. NO, O3, and NO2
c
o
o
20
10 -
0
2400 0300 0600 0900 1200 1500 1800 2100 2400
Time of day
3-5
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11. Ozone's reaction with w causes the amount of ozone near a highway
to be much lower than that found a short distance from the highway.
a. NO
b. NO2
c. oxygen
d. NMHC
12. v) is a major source of ozone while ^) and v) are
relatively minor sources.
a. Stratospheric injection, photochemical reactions of NMHC and NO*, elec-
trical discharges
b. Photochemical reactions of NMHC and NO*, electrical discharges,
stratospheric injection
c. Electrical discharge, photochemical reactions of NMHC and NO,,
stratospheric injection
13. True or False? The ratio of NMHC concentration to NO* concentration affects
the amount of ozone photochemically produced.
For each of questions 14-17, match the stated monitoring purpose with its
appropriate group of pollutants.
14. determine compliance with air a. NMHC, NO2, and O,
quality standards
15. evaluate results of control b. NMHC, NO, NO2, and Ox
measures
16. provide a basis for invoking c. NOt and O,
short-term or emergency
control measures
17. evaluate effects of exposure
on humans
18. Which of the following spatial scales of representativeness is(are) important
for the monitoring of photochemical air pollutants?
a. middle
b. neighborhood
c. urban/regional
d. b and c, above
19. True or False? Source-oriented sites are those associated with siting objectives
that require information regarding impacts from a specific source or a group
of specific sources.
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20. True or False? General sites are those located in areas where information con-
cerning the total air pollutant concentration is important but where informa-
tion concerning contributions from individual sources to the total concentra-
tion is relatively unimportant.
21. v/ -oriented sites are those associated with the measuring of air
pollutants which are in the same chemical state as when they were emitted into
the atmosphere, while ( ' -oriented sites are associated with measuring
air pollutants which have been created by chemical reactions in the
atmosphere.
a. Reactant, product
b. Product, reactant
c. neither a nor b, above
For each of questions 22-25, match the given pollutant with its appropriate general
types of monitoring sites.
22. NMHC a. source-oriented and general neighborhood;
reactant-oriented and general urban/regional
23. NO b. source-oriented and general neighborhood;
reactant-oriented, product-oriented, and
24. NO2 general urban/regional
c. general neighborhood; product-oriented
25. O3 and general urban/regional
3-7
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Review Exercise Answers
Page(s) of Photochemical
Air Pollutants
Siting Manual
1. d 7
2. True 9
3. a 10
4. b 14
5. c 9,13
6. True 9
7. c 12
8. False 9
9. c 13
10. a 15
11. a 13
12. b 13
13. True 16,18
14. a 20
15. b 20
16. b 20
17. c 20
18. d 21
19. True 19
20. True 19
21. a 19
22. a 23
23. a 23
24. b !..23
25. c 23
3-8
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Section 4
Locating Monitoring Stations for
Photochemical Air Pollutants
Reading Assignment
Pages 25-50 of EPA 450/3-78-013 "Site Selection for the Monitoring of
Photochemical Air Pollutants".
Reading Assignment Topics
• General principles of site selection
• Site selection procedures for nonmethane hydrocarbons
• Site selection procedures for nitric oxide and nitrogen dioxide
• Site selection procedures for oxidants (ozone)
Learning Goal and Objectives
Learning Goal
To familiarize you with the siting of nonmethane hydrocarbons, nitric oxide,
nitrogen dioxide, and ozone monitoring stations.
Learning Objectives
When you have completed this section, you should be able to:
1. list in order the major steps involved in selecting a specific monitoring site.
2. recognize the importance of minimizing effects from individual sources on
monitoring sites other than source-oriented sites.
3. recognize that regions associated with strong concentration gradients or sinks
should be avoided when selecting monitoring sites.
4. associate monitoring purposes with types of sites used for monitoring
nonmethane hydrocarbons, nitric oxide, nitrogen dioxide, and ozone.
5. select the general siting area for a source-oriented nonmethane hydrocarbon
monitoring station.
6. select the general siting area for a nonmethane hydrocarbon background
monitoring station for an elevated point source.
7. select the general siting area for a reactant-oriented nonmethane hydro-
carbon monitoring station.
8. select probe locations for nonmethane hydrocarbon monitoring stations.
4-1
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9. select general siting areas for monitoring maximum short-term and long-
term average nitrogen dioxide concentrations resulting from an elevated
point source.
10. select general siting areas for locating reactant-oriented and product-
oriented neighborhood NO/NO2 monitoring stations.
11. select the general siting area for a product-oriented regional NO2 monitoring
site.
12. select the general siting areas for regional and neighborhood ozone moni-
toring sites.
Reading Guidance
• Refer often to the tables, flow charts, and figures of the assigned reading
material as you progress through the assignment.
• The table on page 40 of the reading assignment should be labeled Table 9.
• Because "Site Selection for the Monitoring of Photochemical Air Pollutants"
was published before the promulgation of 40 CFR 58, the roadway minimum
separation distances for neighborhood NO2 and O3 monitoring stations
specified in the document do not agree with the required minimum separation
distances of 40 CFR 58. Roadway minimum separation distances specified in
40 CFR 58 are addressed in Section 6 of this guidebook.
• When you have finished the reading assignment, complete the review exercise
for Section 4. It begins on the following page.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), take Quiz 2. Follow
the directions listed in the Course Introduction section of this guidebook.
• After completing Quiz 2, proceed to Section 5 of this guidebook.
4-2
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Review Exercise
Now that you've completed the assignment for Section 4, please answer the fol-
lowing questions. These will help you determine whether or not you are mastering
the material.
1. Which of the following is the proper sequence of major steps involved in
selecting a monitoring site?
a. identify general site location, identify purpose of monitoring, identify type
of site that will best serve the monitoring purpose, identify specific moni-
toring site
b. identify general site location, identify specific monitoring site, identify pur-
pose of monitoring, identify type of site that will best serve the monitoring
purpose
c. identify purpose of monitoring, identify type of site that will best serve the
monitoring purpose, identify general site location, identify specific moni-
toring site
2. True or False? The most important principle in the selection of specific
monitoring sites is that the effects from individual sources, other than those of
interest in source-oriented monitoring, should be minimal.
3. True or False? In general, monitoring sites should be located in areas
associated with strong concentration gradients or sinks.
For each of questions 4-6, match the stated NMHC monitoring purpose with its
appropriate types of monitoring sites.
4. determine compliance with
air quality standards
5. evaluate results of control
measures
6. provide a basis for
invoking short-term or
emergency control measures
a. reactant-oriented and general
urban/regional; general neighborhood
b. general urban/regional;
source-oriented neighborhood
c. reactant-oriented urban/regional
4-3
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For each of questions 7-10, match the stated NO2 monitoring purpose with its
appropriate types of monitoring sites.
7. determine compliance with
air quality standards
evaluate results of control
8.
10.
measures
provide a basis for
invoking short-term or
emergency control measures
evaluate effects of
human exposure
a. reactant-oriented and general
urban/regional; source-oriented
and general neighborhood
b. general urban/regional;
source-oriented neighborhood
c. reactant-oriented, product-oriented, and
general urban/regional; source-
oriented and general neighborhood
d. general urban/regional; source-
oriented and general neighborhood
For each of questions 11-13, match the stated O3 monitoring purpose with its
appropriate types of monitoring sites.
11
determine compliance with
air quality standards
12. provide a basis for
invoking short-term or
emergency control measures
13. evaluate effects of
human exposure
a. product-oriented and general
urban/regional; general neighborhood
b. general urban/regional;
general neighborhood
14. For NO, a
site is the appropriate type of monitoring site for pro-
viding a basis for invoking short-term or emergency control measures.
a. general urban/regional
b. reactant-oriented urban/regional
c. source-oriented neighborhood
d. general neighborhood
4-4
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15. Which of the four general siting areas, labeled a through d, is the best siting
area for a monitoring station for determining 6 to 9 a.m. peak NMHC concentra-
tions resulting from the isolated point source?
Wind rose for
extremely unstable
atmospheric conditions
Wind rose for
slightly unstable
atmospheric conditions
Isolated point source
16. Which of the four general siting areas, labeled a through d in question 15, is
the best siting area for an NMHC background monitoring station?
4-5
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17. True or False? A monitoring site for measuring maximum NMHC concentra-
tions resulting from an NMHC point source probably should be located
somewhat farther from the point source than the distance predicted for max-
imum concentrations.
18. The figure below represents a region with relative NMHC concentrations
plotted. Which of the four general siting areas, labeled a through d, is the best
siting area for a reactant-oriented NMHC monitor?
Wind rose for
low to moderate
ambient temperatures
and moderate to high
wind speeds
School
Wind rose for
igh ambient
temperatures
and low wind speeds
IB
Senior
citizen
apartments
19. An NMHC monitor's probe inlet should be located about w meters
above ground level.
a. 2 to 10
b. 3 to 10
c. 2 to 20
d. 3 to 15
20. The probe inlet for an NMHC monitor should be located at least about
v ' meter(s) above its supporting structure.
a. 0.5
b. 1
c. 3
d. 5
4-6
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21. The probe inlet for an NMHC monitor should be located at least
v / meters from a roadway having an average daily traffic (ADT)
volume less than 1,000.
a. 5
b. 15
c. 25
d. 50
22. The minimum separation between the inlet probe of an NMHC monitor and a
roadway having an average daily traffic (ADT) volume greater than 10,000
should be (?) meters.
a. 50
b. 100
c. 200
d. 400
23. An NMHC monitor's probe inlet should be located away from surrounding
obstacles so that the distance between an obstacle and the inlet is at least
about ( ' times the height that the obstacle protrudes above the inlet.
a. 2
b. 4
c. 5
d. 10
24. In general, areas of highest v) average NO/NO2 concentrations
resulting from an elevated point source are more likely to occur nearer the
point source than are areas of highest ( ' average NO/NO2 concentra-
tions resulting from the point source.
a. long-term, short-term
b. short-term, long-term
c. neither a nor b, above
25. True or False? A monitoring site for measuring maximum NOZ concentrations
resulting from an NO* point source should be located somewhat farther from
the point source than the distance predicted for maximum NO* concentrations.
4-7
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26. The figure below represents a region with relative NOX concentrations plotted.
Which of the four general siting areas, labeled a through d, is the best siting
area for a reactant-oriented neighborhood NO* monitor?
Wind rose for
high ambient
temperatures
and low wind speeds
School
Wind rose for
low to moderate
ambient temperatures
and moderate to high
wind speeds
am mm m
fflaaa
aria a
Senior
citizen
apartments
,120
4-8
-------
27. The figure below represents a city area with relative NO^ emissions plotted.
Which of the four general siting areas, labeled a through d, is the best siting
area for locating a product-oriented neighborhood NO2 monitoring site to
measure maximum short-term average NO2 concentrations?
Wind rose
for high ambient
temperatures
and low wind speeds.
28. Which of the four general siting areas, labeled a through d in question 27, is
the best siting area for locating a product-oriented neighborhood NO2
monitoring site to measure maximum long-term average NOZ concentrations?
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29. Which of the four general siting areas, labeled a through d, is the best siting
area for locating a product-oriented regional NO2 monitoring site?
Wind rose
Urban area
(population: 2,000,000)
0 25. 50 75
Kilometers
100
4-10
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30. Select the value that was assumed for the undue influence NO, concentration
level (ppb) in determining the NO2 regional scale interference distances for
urban areas.
a. 1
b. 7
c. 23
d. 50
31. Which of the four general siting areas, labeled a through d, is the best siting
area for locating a regional O3 monitoring site?
Wind rose
for high ambient
temperatures
Urban area
(population: 2,000,000)
_L
25 50 75
Kilometers
100
4-11
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32. The figure below represents a city area with relative ozone concentrations
plotted. Which of the four general siting areas, labeled a through d, is the best
siting area for assessing ozone concentrations in the city neighborhoods that
have average neighborhood scale ozone concentrations?
Wind rose for periods
of high ozone concentrations
(average wind speed of 10 kilometers per hour)
City boundary
Suburban area
1
0
I 1
10 20
1
30
I I
40 50
Kilometers
33. Which of the four general siting areas, labeled a through d in question 32, is
the best siting area for measuring maximum ozone concentrations?
34. True or False? Monthly wind roses are more useful than high-temperature
wind roses for determining wind directions during periods which are conducive
to the photochemical formation of ozone.
4-12
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Review Exercise Answers
Page(s) of Photochemical
Air Pollutants
Siting Manual
1. c 25
2. True 25
3. False 25
4. c 26
5. b 26
6. a 26
7. a 26
8. b 26
9. c 26
10. d 26
11. a 26
12. a •. 26
13. b 26
14. c 26
15. b 27,33
16. d 33
17. True 33
18. a 27,38
19. d 27,38
20. b 38
21. b 27
22. d 27
23. a 38
24. b 41
25. True 41
26. b 43-44
27. a 43-44
28. b 43-44
29. a 44-46
30. b 45
31. d 45-46,48-49
32. b 48-49
33. d 48-50
34. False 49
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Section 5
Rationale for Monitor-Siting Criteria
for Photochemical Air Pollutants
Reading Assignment
Pages 51-100 of EPA 450/3-78-013 "Site Selection for the Monitoring of
Photochemical Air Pollutants".
Reading Assignment Topics
• Identification of conditions conducive to high pollutant concentrations
• Identification of general areas suitable for monitoring
• Local effects and the selection of specific sites
Learning Goal and Objectives
Learning Goal
To familiarize you with the logic of the monitor-siting criteria for photochemical
air pollutants.
Learning Objectives
When you have completed this section, you should be able to:
1. identify essential ingredients for the photochemical formation of high ozone
concentrations.
2. recognize meteorological conditions that favor the formation of high ozone
concentrations.
3. recognize meteorological conditions that favor maximum long-term ground
level pollutant concentrations resulting from emissions from elevated point
sources.
4. describe the relationship between distributions of nonmethane hydrocarbons
and nitric oxide ambient air concentrations and distributions of nonmethane
hydrocarbons and nitric oxide emissions.
5. describe spatial and temporal separations between precursor emissions and
NO2 and Os ambient air concentrations.
6. describe conditions conducive to the formation of high NOj concentrations
in the vicinity of strong NO emissions.
7. describe relative locations of NO2 and Os maximum ambient air
concentrations.
5-1
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8. describe assumptions for determining the areas of maximum ozone concen-
trations resulting from urban areas.
9. recognize potential scavenging of NO2 and O3 by obstructions.
10. describe air cavity effects of buildings.
11. recognize the scavenging of O3 near roadways by nitric oxide emissions from
motor vehicles.
12. describe assumptions for determining minimum separation distance between
roadways and NMHC monitor probes.
13. recognize the scavenging of O3 by valleys.
Reading Guidance
• Refer often to the tables and figures of the assigned reading material as you
progress through the assignment.
• Although it is stated on page 52 of the reading assignment that Figure 22
shows 13 cases when the average temperature exceeded 75°F and ozone
remained below 80 ppb, the figure actually indicates only 12 such cases.
• Try to visualize how the siting criteria would be affected if the assumptions
described in this reading assignment were altered.
• When you have finished the reading assignment, complete the review exercise
for Section 5. It begins on the following page.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), proceed to Section 6
of this guidebook.
5-2
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Review Exercise
Now that you've completed the assignment for Section 5, please answer the fol-
lowing questions. These will help you determine whether or not you are mastering
the material.
1. Which of the following ingredients is(are) essential for the photochemical for-
mation of high concentrations of ozone?
a. an accumulation of precursor emissions
b. sunshine
c. relatively little ozone removal
d. all of the above
2. v) ambient temperatures and v) wind speeds favor the
formation of high ozone concentrations.
a. Low, low
b. High, high
c. Low, high
d. High, low
3. High ozone concentrations occur most frequently during v/
a. January and February
b. November and December
c. January, February, and March
d. June, July, and August
4. The most commonly occurring combination of wind speed and wind direction
during w atmospheric conditions will often determine where the
maximum long-term average ground-level pollutant concentrations resulting
from emissions from an elevated point source will occur.
a. neutral
b. slightly stable
c. stable
d. unstable
5. True or False? Most of the ambient concentrations of inert pollutants whose
emission sources are near ground level result from nearby sources.
6. True or False? Spatial and temporal separations of precursor emissions and
ozone concentrations may be quite large.
7. True or False? Spatial and temporal separations of NO emissions and NOZ
concentrations resulting from the NO emissions can be quite large if local
ozone concentrations are high, or smaller if ozone concentrations are low.
5-3
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8. Which of the following conditions favor the formation of high NO2 concentra-
tions in the vicinity of strong NO emissions?
a. high O3 concentrations and nearly stagnant winds
b. high O3 concentrations and appreciable winds
r Inw O. rnnrpnfraHnns and staonanf winds
g 3 concentratons an apprecae w
low O3 concentrations and stagnant winds
d. all of the above
9. Maximum NO2 concentrations are found (•' maximum ozone
concentrations.
a. upwind of
b. downwind of
c. at the same location as
10. Which of the following assumptions was(were) made in locating the area of
maximum ozone concentrations resulting from emissions of a relatively large
urban area?
a. Maximum ozone concentrations are most likely to accompany large
accumulations of precursor emissions.
b. Large accumulations of precursor emissions are most likely in air that
travels across the entire emitting region, especially during the morning rush
hour.
c. Maximum ozone concentrations are reached in the early to middle after-
noon, after the morning rush hour emissions have been traveling 5 to 7
hours.
d. Emissions of NO within the metropolitan area will destroy ozone near
ground level and keep the concentrations below their maxima.
e. all of the above
1 1 . True or False? In locating areas of maximum ozone concentrations resulting
from emissions of a small urban area, it was assumed that lateral mixing of
clean air into the urban plume increases the separation distance between the
urban area and the area of maximum ozone concentrations.
12. True or False? In locating areas of maximum ozone concentrations resulting
from emissions of large sprawling metropolitan areas, it was assumed that the
metropolitan areas may contain "islands" of low NO emissions which may be
locations of maximum ozone concentrations.
13. True or False? Ozone and perhaps NO* can be destroyed by coming into
contact with obstructions.
14. An air cavity extends downwind of a building about v) heights of the
building.
a. 1.5
b. 4.5
c. 9
d. 15
15. True or False? Ozone near roadways will be destroyed by nitric oxide emitted
by motor vehicles.
5-4
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For each of questions 16-21, select the value that was assumed for the specified
parameter when determining the separation distances between roadways and
NMHC monitor probes.
16. Undue influence NMHC concentration level (pphm):
a. 1
b. 8
c. 20
d. 50
17. Wind speed (m/s):
a. 0.1
b. 1
c. 5
d. 10
18. NMHC emission rate for pre-1970 model vehicles (g/mile):
a. 0.5
b. 1
c. 4
d. 10
19. Peak hour traffic volume (percent of average daily traffic):
a. 10
b. 20
c. 35
d. 50
20. Atmospheric stability
a. neutral
b. slightly stable
c. stable
d. unstable
21. Initial vertical dispersion height (m):
a. 0.25
b. 0.5
c. 1.5
d. 2.5
22. True or False? In general, ozone concentrations found in valleys are lower than
typical ambient ozone concentrations.
5-5
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Review Exercise Answers
Page(s) of Photochemical
Air Pollutants
Siting Manual
1. d 51
2. d 51-53
3. d 52,55
4. a 52
5. True 52,57
6. True 57
7. False 57
8. d 57
9. a 60
10. e 69
11. False 69
12. True 69
13. True 87
14. a 87
15. True 92
16. b 92
17. b 92
18. c 92
19. a 92
20. b 94
21. c 94
22. True 97,99
5-6
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Section 6
Monitoring Network Design
and Probe-Siting Criteria for SLAMS,
NAMS, and PSD Monitoring Stations
for CO, O3, and NO2
Reading Assignment
Pages 6-4 through 6-16 of this guidebook.
Reading Assignment Topics
• Excerpts of 40 CFR 58 Appendix D
• SLAMS network design for CO, O3) and NOj monitoring stations
• NAMS network design for CO, O3, and NO2 monitoring stations
• Excerpts of 40 CFR 58 Appendix E
• Probe-siting criteria for CO SLAMS and NAMS
• Probe-siting criteria for Os SLAMS and NAMS
• Probe-siting criteria for NO2 SLAMS and NAMS
• Materials of construction and maximum sample residence times for NOj
and Os probes
• Waiver provisions for SLAMS and NAMS probe-siting criteria
• Excerpts of "Ambient Monitoring Guidelines for Prevention of Significant
Deterioration (PSD)" (EPA 450/4-80-012)
• Network design for PSD monitoring stations
• Probe-siting criteria for ground-level sources
Learning Goal and Objectives
Learning Goal
To familiarize you with regulations and guidelines concerning monitoring network
design and probe-siting criteria for CO, Os, and NO2 SLAMS, NAMS, and PSD
monitoring stations.
6-1
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Learning Objectives
When you have completed this section, you should be able to:
1. recognize the four basic monitoring objectives of SLAMS.
2. associate SLAMS monitoring objectives with spatial scales of representativeness.
3. recognize applicable spatial scales of representativeness for CO, Os, and NO2
SLAMS.
4. recognize the primary monitoring objective of NAMS.
5. describe the two basic categories of NAMS.
6. recognize the two primary uses of NAMS data.
7. determine the number of CO, Os, and NO2 NAMS required for a given
monitoring area.
8. recognize the spatial scales of representativeness required for CO, O3, and
NO2 NAMS.
9. select probe locations for CO, O3, and NO2 SLAMS, NAMS, and PSD
monitoring stations.
10. select the appropriate materials of construction and the maximum sample
residence times for O3 and NO2 probes.
11. describe waiver provisions for SLAMS and NAMS probe-siting criteria.
12. select general siting areas for PSD monitoring stations.
13. estimate the number of CO, Os, and NO2 monitoring stations needed for
preconstruction and postconstruction PSD monitoring networks.
14. define ambient air.
15. recognize that PSD monitors should be located in ambient air areas.
16. select appropriate probe heights for O3l and NOZ PSD monitors used to
measure impacts of ground-level sources.
Reading Guidance
• SLAMS and NAMS are required for State Implementation Plan ambient air
quality monitoring networks.
• The information concerning SLAMS and NAMS contained in the assigned
reading material is stated as a regulation.
• PSD monitoring stations are used to determine the air quality impacts of
existing or proposed sources that are located in areas meeting the National
Ambient Air Quality Standards (NAAQS).
• The information concerning PSD monitoring stations contained in the assigned
reading material is stated as a guideline.
• The probe-siting criteria for CO PSD monitoring stations are identical to the
probe-siting criteria for CO SLAMS and NAMS.
• The probe-siting criteria for Os and NO2 PSD monitoring stations are iden-
tical to the probe-siting criteria for Os and NOZ SLAMS and NAMS except for
the PSD monitoring of ground-level sources. Therefore, only ground-level
source monitoring information is included in the PSD monitor-siting portion of
the reading assignment.
6-2
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• NMHC monitoring is not required for PSD purposes because O3 monitoring is
required in lieu of NMHC monitoring.
• Table 4 of the excerpts of 40 CFR 58 Appendix D is incorrectly titled as
"Figure 5-2. Paniculate field data". The correct title is "Summary of Spatial
Scales for SLAMS and Required Scales for NAMS".
• < 110,000 which appears in Tables 2 and 3 of the excerpts of 40 CFR 58
Appendix E should be > 110,000.
• The last reference found in the footnotes of the excerpts of 40 CFR 58 Appen-
dix E should read 21-22, not 21-21.
• When you have finished the reading assignment, complete the review exercise
for Section 6. It begins on page 6-17.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), take the final
examination for the course. Follow the directions listed in the Course
Introduction section of this guidebook.
• Your course grade results will be mailed to you.
6-3
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Excerpts of 40 CFR 58 Appendices D and E
Chapter I—Environmental Protection Agency
Title 40—Protection of Environment
APR. D
APPENDIX D—NETWORK DESIGN FOR STATE
AND LOCAL AIR MONITORING STATIONS
(SLAMS) AND NATIONAL AIR MONITORING
STATIONS (NAMS)
1. SLAMS Monitoring Objectives and Spa-
tial Scales
2. SLAMS Network Design Procedures
2.1 Background Information /or Estab-
lishing SLAMS
2.2 Total Suspended Participates (TSP)
Design Criteria for SLAMS
2.3 Sulfur Dioxide (SO,) Design Criteria
for SLAMS
2.4 Carbon Monoxide (CO) Design Crite-
ria for SLAMS
2.5 Ozone (O.) Design Criteria for
SLAMS
2.6 Nitrogen Dioxide (NO,) Design Crite-
ria for SLAMS
3. Network Design for National Air Moni-
toring Stations (NAMS)
3.1 Total Suspended Particulates (TSP)
Design Criteria for NAMS
3.2 Sulfur Dioxide (SO,) Design Criteria
for NAMS
3.3 Carbon Monoxide (CO) Design Crite-
ria for NAMS
3.4 Ozone (O,) Design Criteria for NAMS
3.5 Nitrogen Dioxide (NO,) Design Crite-
ria for NAMS
4. Summary
5. References
1. SLAMS MONITORING OBJECTIVES AND
SPATIAL SCALES
The purpose of this appendix is to de-
scribe monitoring objectives and general cri-
teria to be applied in establishing the State
and Local Air Monitoring Stations (SLAMS)
networks and for choosing general locations
for new monitoring stations. It also de-
scribes criteria for determining the number
and location of National Air Monitoring
Stations (NAMS). These criteria will also be
used by EPA in evaluating the adequacy of
SLAMS/NAMS networks.
The network of stations which comprise
SLAMS should be designed to meet a mini-
mum of four basic monitoring objectives.
These basic monitoring objectives are: (1)
To determine highest concentrations ex-
pected to occur in the area covered by the
network; (2) to determine representative
concentrations in areas of high population
density; (3) to determine the impact on am-
bient pollution levels of significant sources
or source categories; and (4) to determine
general background concentration levels.
To a large extent, the existing State Im-
plementation Plan (SIP) monitoring net-
works have been designed with these four
objectives in mind. Thus, they can serve as
the logical starting point for establishing
the SLAMS network, This will, however, re-
quire a careful review of each existing SIP
ambient network to determine the principal
objectives of each station and the extent to
which the location criteria presented herein
are being met. It should be noted that this
appendix contains no criteria for determin-
ing the total number of stations in SLAMS
networks. The optimum size of a particular
SLAMS network involves trade offs among
data needs and available resources which
EPA believes can best be resolved during
the network design process.
This appendix focuses on the relationship
between monitoring objectives and the geo-
graphical location of monitoring stations
Included are a rationale and set of general
criteria for identifying candidate station lo-
cations in terms of physical characteristics
which most closely match a specific moni-
toring objective. The criteria for more spe-
cifically siting the monitoring station in-
cluding spacing from roadways and vertical
and horizontal probe placement, are de-
scribed in Appendix E of this part.
To clarify the nature of the link between
general monitoring objectives and the phys-
ical location of a particular monitoring sta-
tion, the concept of spatial scale of repre-
sentativeness of a monitoring stat'an is de-
fined. The goal in siting stations is to cor-
rectly match the spatial scale represented
by the sample of monitored air with the
spatial scale most appropriate for the moni-
toring objective of the station.
Thus, spatial scale of representativeness is
described in terms of the physical dimen-
sions ol the air parcel nearest to a monitor-
ing station throughout which actual pollut-
ant concentrations are reasonably similar.
The scale of representativeness of most in-
terest for the monitoring objectives defined
above are as follows:
• Microscale—defines the concentrations
in air volumes associated with area dimen-
sions ranging from several meters up to
about 100 meters.
• Middle Scale—defines the concentration
typical of areas up to several city blocks in
size with dimensions ranging from about 100
meters to 0.5 kilometer.
• Neighborhood Scale—defines concentra-
tions within some extended area of tne city
that has relatively uniform land use with di-
mensions in the 0.5 to 4.0 kilometers range.
• Urban Scale—defines the overall,
citywide conditions with dimensions on the
order of 4 to 50 kilometers. This scale would
usually require more than one site for defi-
nition.
• Regional Scale—defines usually a rural
area of reasonably homogeneous geography
and extends from tens to hundreds of kilo-
meters.
• National and Global Scales—these mea-
surement scales represent concentrations
characterizing the nation and the globe as a
whole.
Proper siting of a monitoring station re-
quires precise specification of the monitor-
ing objective which usually includes a de-
sired spatial scale of representativeness. For
example, consider the case where the objec-
tive is to determine maximum CO concen-
trations in areas where pedestrians may rea-
sonably be exposed. Such areas would most
likely be located within major street can-
yons of large urban areas and near traffic
corridors. Stations located in these areas are
most likely to have a microscale of repre
sentativeness since CO concentrations typi-
cally peak nearest roadways and decrease
rapidly as the monitor is moved from the
roadway. In this example, physical location
was determined by consideration ol CO
emission patterns, pedestrian activity, and
physical characteristics affecting pollutant
dispersion. Thus, spatial scale of representa-
tiveness was not used in the selection proc-
ess but was a result of station location.
In some cases, the physical location of a
station is determined from joint considera-
tion of both the basic monitoring objective.
and a desired spatial scale of representative-
ness. For example, to determine CO concen-
trations which are typical over a reasonably
broad geographic area having relatively
high CO concentrations, a neighborhood
scale station is more appropriate. Such a
station would likely be located in a residen-
tial or commercial area having a high over-
all CO emission density but not in the im-
mediate vicinity of any single roadway. Note
that in this example, the desired scale of
representativeness was an important factor
in determining the physical location of the
monitoring station.
In either case, classification of the station
by its intended objective and spatial scale of
representativeness is necessary and will aid
in interpretation of the monitoring data.
Table 1 illustrates the relationship be-
tween the four basic monitoring objectives
and the scales of representativeness that are
generally most appropriate for that objec-
tive.
TABLE 1.—Relationship among monitoring
objectives and scale of representativeness
Monitoring objective
Appropriate siting scales
Highest concentration Micro, middle, neighborhood (some-
times urban)
Population Neighborhood, urban
Source impact Micro, middle, neighborhood
General/background Neighborhood, regional
Subsequent sections of this appendix de-
scribe in greater detail the most appropriate
scales of representativeness and general
monitoring locations for each pollutant.
2. SLAMS NETWORK DESIGN PROCEDURES
The preceding section of this appendix
has stressed the importance of defining the
objectives for monitoring a particular pol-
lutant. Since monitoring data are collected
to "represent" the conditions in a section or
subregion of a geographical area, the previ-
ous section included a discussion of the
scale of representativeness of a monitoring
station. The use of this physical basis for lo-
cating stations allows for an objective ap-
proach to network design.
The discussion of scales in Sections 2.2-2.6
does not include all of the possible scales for
each pollutant. The scales which are dis-
cussed are those w.iich are felt to be most
pertinent for SLAMS network design.
In order to evaluate a monitoring network
and to determine the adequacy of particular
monitoring stations, it is necessary to exam-
ine each pollutant monitoring station indi-
vidually by stating its monitoring objective
and determining its spatial scale of repre-
sentativeness. This will do more than insure
compatibility among stations of the same
type. It will also provide a physical basis for
the interpretation and application of the
data. This will help to prevent mismatches
between what the data actually -epresem
and what the data are interpreted to repre-
6-4
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Chapter I—Environmental Protection Agency
Title 40—Protection of Environment
App. D
sent. It is important to note that SLAMS
are not necessarily sufficient for completely
describing air quality. In many situations.
diffusion models must be applied to comple-
ment ambient monitoring, e.g.. determining
the impact of point sources or defining
boundaries of nonattainment areas.
2.1 Background Information for Estab-
lishing SLAMS
Background information that must be
considered in the process of selecting
SLAMS from the existing network and in
establishing new SLAMS includes emission
inventories, climatological summaries, and
local geographical characteristics. Such in-
formation is to be used as a basis for the
judgmental decisions that are required
during the station selection process. For
new stations, the background information
should be used to decide on the actual loca-
tion considering the monitoring objective
and spatial scale while following the de-
tailed procedures in References 1 through 4.
Emission inventories are generally the
most important type of background infor-
mation needed to design the SLAMS net-
work. The emission data provide valuable
information concerning the size and distri-
bution of large point sources. Area source
emissions are usually available for counties
but should be subdivided into smaller areas
or grids where possible, especially if diffu-
sion modeling is to be used as a basis for de-
termining where stations should be located.
Sometimes this i.-uoi be done rather crude-
ly, for example, on the basis of population
or housing units. In general, the grids
should be smaller in areas of dense popula-
•ion than in less densely populated regions.
Emission inventory information for point
sources should be generally available lor
any area of the country for annual and sea-
sonal averaging times. Specific information
characterizing the emissions from large
point sources for the shorter averaging
times (diurnal variations, load curves, etc.)
can often be obtained from the source. Area
source emission data by season, although
no! available from the EPA. can be generat-
ed by apportioning annual totals according
to degree days.
Detailed area source data are also valua-
ble in evaluating the adequacy of an exist-
ing station in terms of whether the station
has been located in the desired spatial scale
of representativeness. For example, it may-
be the desire of an agency to have an exist-
ing CO station measuring in the neighbor-
hood scale.
By examining the traffic data for the area
and examining the physical location of the
station with respect to the roadways, a de-
termination can be made as to whether or
not the station is indeed measuring the air
quality on the desired scale.
The climatological summaries of greatest
use are the frequency distributions of wind
speed and direction. The wind rose is an
easily interpreted graphical presentation of
the directional frequencies. Other types of
useful climatological data are also available.
but generally are not as directly applicable
to the site selection process as are the wind
statistics.
In many cases, the meteorological data
originating from the most appropriate (not
necessarily the nearest) national weather
service (NWS) airport station in the vicinity
of the prospective siting area will adequate-
ly reflect conditions over the area of inter-
est, at least for annual and seasonal averag-
ing times. In developing data in complex
meteorological and terrain situations, diffu-
sion meteorologists should be consulted.
NWS stations can usually provide most of
the relevant weather information in support
of network design activities anywhere in the
country. Such information includes joint
frequency distributions of winds and atmos-
pheric stability (stability-wind roses).
The geographical material is used to de-
termine the distribution of natural features.
such as forests, rivers, lakes, and manmade
features. Useful sources of such information
may include road and topographical maps.
aerial photographs, and even satellite pho-
tographs. This information may include the
terrain and land-use setting of the prospec-
tive monitor siting area, the proximity of
larger water bodies, the distribution of pol-
lutant sources in the area, the location of
NWS airport stations from which weather
data may be obtained, etc. Land use and to-
pographical characteristics of specific areas
of interest can be determined from U.S.
Geological Survey (USGS) maps and land
use maps. Detailed information on urban
physiography (building/street dimensions.
etc.) can be obtained by visual observations.
aerial photography, and also surveys to sup-
plement the information available from
those sources. Such information could be
used in determining the location of local
pollutant sources in and around the pros-
pective station locations.
2.4 Carbon Monoxide (CO) Design Criteria
for SLAMS
Micro, middle, and neighborhood scale
measurements are necessary station classifi-
cations for SLAMS since most people are
exposed to CO concentrations In these
scales. Carbon monoxide maxima occur pri-
marily in areas near major roadways and in-
tersections with high traffic density and
poor atmospheric ventilation. As these
maxima can be predicted by ambient air
quality modeling, a large fixed network of
CO monitors is not required. Long-term CO
monitoring should be confined to a limited
number of micro and neighborhood scale
stations in large metropolitan areas to meas-
ure maximum pollution levels and to deter-
mine the effectiveness of control strategies.
• Microscale.— Measurements on this scale
would represent distributions within street
canyons, over sidewalks, and near major
roadways. The measurements at a particu-
lar location in a street canyon would be
typical of one high concentration area
which can be shown to be a representation
of many more areas throughout the street
canyon or other similar locations In a city.
This is a scale of measurement that would
provide valuable information for devising
and evaluating "hot spot" control measures
• Middle Scale.— This category covers di-
mensions from 100 meters to 0.5 kilometer.
In certain cases discussed below, it may
apply to regions that have a total length of
several kilometers. In many cases of inter-
est, sources and land use may be reasonably
homogeneous for long distances along a
street, but very inhomogeneous normal to
the street. This is the case with strip devel-
opment and freeway corridors. Included in
this category are measurements to charac-
terize the CO concentrations along the
urban features just enumerated. When a lo-
cation is chosen to represent conditions in a
block of street development, then the char-
acteristic dimensions of this scale are tens
ol meters by hundreds of meters. If an at-
tempt is made to characterize street-side
conditions throughout the downtown area
or along an extended stretch of freeway, the
dimensions may be tens of meters by kilo-
meter.
The middle scale would also include the
parking lots and feeder streets associated
with indirect sources which attract signifi-
cant numbers of pollutant emitters, particu-
larly autos. Shopping centers, stadia, and
office buildings are examples of indirect
sources.
• Neighborhood Scale.—Measurements in
this category would represent conditions
throughout some reasonably homogeneous
urban subregions. with dimensions of a few
kilometers and generally more regularly
shaped than the middle scale. Homogeneity
refers to CO concentration, but it probably
also applies to land use. In some cases, a lo-
cation carefully chosen to provide neighbor-
hood scale data, might represent not only
the immediate neighborhood, but also
neighborhoods of the same type in other
parts of the city. These kinds of stations
would provide Information relating to
health effects because they would represent
conditions in areas where people live and
work. Neighborhood scale data would pro-
vide valuable Information for developing.
testing, and revising concepts and models
that describe the larger scale concentration
patterns, especially those models relying on
spatially smoothed emission fields for
inputs. These types of measurements could
also be used for interneighborhood compari-
sons within or between cities.
After the spatial scale has been deter-
mined to meet the monitoring objectives for
each location, the location selection proce-
dures, as shown in reference 3 should be
used to evaluate the adequacy of each exist-
ing CO station and must be used to relocate
an existing station or to locate any new
SLAMS stations. The background material
necessary for these procedures may include
the average daily traffic on all streets in the
area, wind roses for different hours of the
day. and maps showing one-way streets.
street widths, and building heights. If the
station is to typify the area with the highest
concentrations, the streets with the greatest
daily traffic should be identified. If some
streets are one-way, those streets that have
the greatest traffic during the afternoon
and evening hours should be selected as ten-
tative locations, because the periods of high
traffic volume are usually of greatest dura-
tion through the evening hours. However,
the strength of the morning inversion has
to be considered along with the traffic
volume and pattern when seeking areas
with the highest concentrations. Traffic
counters near the stations will provide valu-
able data for interpreting the observed CO
Concentrations.
Monitors should not be placed in the vi-
cinity of possible anomalous source areas.
Examples of such areas include toll gates on
turnpikes, metered freeway ramps, and
drawbridge approaches. Additional informa-
tion on network design may be found in ref-
erence 3.
2.5 Ozone (O,) Design Criteria for
SLAMS
Ozone is not directly emitted into the at-
mosphere but results from complex photo-
chemical reactions involving organic com-
pounds, oxides of nitrogen, and solar radi-
ation.
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Chapter I—Environmental Protection Agency
Title 40—Protection of Environment
App. D
The relationships between primary emis
sions (precursors) and secondary pollutants
(O,) tend to produce large separations spa-
tially and temporally between the major
sources and the areas of high oxidant pollu-
tion. This suggests that the meteorological
transport process and the relationships be-
tween sources and sinks need to be consid-
ered in the development of the network
design criteria and placement of monitoring
stations, especially in measuring peak con-
centration levels.
The principal spatial scales for SLAMS
purposes based on the monitoring objectives
are neighborhood, urban, regional, and to a
lesser extent, middle scale. Since onone re-
quires appreciable formation time, the
mixing of reactants and products occurs
over large volumes of air. and this reduces
the importance of monitoring small scale
spatial variability.
• Middle Scale. — Measurement in this
scale would represent conditions close to
sources of NO, such a-s roads where it would
be expected that suppression of O, concen-
trations would occur. Measurements at
these stations would represent conditions
over relatively small portions of the urban
area.
• Neighborhood Scale.—Measurements in
this category represent conditions through-
out some reasonably homogeneous urban
subregion. with dimensions of a few kilome-
ters. Homogeneity refers to pollutant con-
centrations. Neighborhood scale data will
provide valuable information for developing.
testing, and revising concepts and models
that describe urban/regional concentration
patterns. They will be useful to the under
standing and definition of processes that
take periods of hours to occur and hence in-
volve considerable mixing and transport.
Under stagnation conditions, a station locat-
ed in the neighborhood scale may also expe-
rience peak concentration levels within the
urban areas.
• Urban Scale.— Measurement in this scale
will be used to estimate concentrations over
large portions of an urban area with dimen-
sions of several kilometers to 50 or more ki-
lometers. Such measurements will be used
for determining trends, and designing area-
wide control strategies. The urban scale sta-
tions would also be used to measure high
concentrations downwind of the area having
the highest precursor emissions.
• Regional Scale. — This scale of measure-
ment will be used to typify concentrations
over large portions of a metropolitan area
and even larger areas with dimensions of as
much as hundreds of kilometers. Such mea-
surements will be useful for assessing the
ozone that is transported into an urban
area. Data from such stations may be useful
in accounting for the ozone that cannot be
reduced by control strategies in that urban
area.
The location selection procedure contin-
ues after the spatial scale is selected based
on the monitoring objectives. The appropri-
ate network design procedures as found in
reference 4, should be used to evaluate the
adequacy of each existing O, monitor and
must be used to relocate an existing station
or to locate any new O, SLAMS stations.
The first step in the siting procedure would
be to collect the necessary background ma-
terial, which may consist of maps, emission
inventories for nonmethane hydrocarbons
and oxides of nitrogen (NO,), climatological
data, and existing air quality data for ozone,
nonmethane hydrocarbons, and NO,/NO
For locating a neighborhood scale station
to measure typical city concentrations, a
reasonably homogeneous geographical area
near the center of the region should be se-
lected which is also removed from the influ
ence of major NOX sources. For an urban
scale station to measure the high concentra-
tion areas, the emission inventories should
be used to define the extent of the area of
important nonmethane hydrocarbons and
NO* emissions. The most frequent wind
speed and direction for periods of important
photochemical activity should be deter-
mined. Then the prospective monitoring
area should be selected in a direction from
the city that is mcst frequently downwind
during periods of photochemical activity.
The distance from the station to the upwind
edge of the city should be about equal to
:.he distance traveled by air moving for 5 to
7 hours at wind speeds prevailing during pe-
riods of photochemical activity. Prospective
areas for locating O, monitors should
always be outside the area of major NOX.
In locating a neighborhood scale station
which is to measure high concentrations.
the same procedures used for the urban
scale are followed except that the station
should be located closer to the areas border-
ing on the center city or slightlj further
downwind in an area of high density popula-
tion.
For regional scale background monitoring
stations, the most frequent wind associated
with important photochemical activity
should be determined. The prospective mon-
itoring area should be upwind for the most
frequent direction and outside the area of
city influence.
Where ozone levels have significant fluc-
tuations throughout the year, consideration
should be given to monitoring ozone only
during the seasons when levels above the
NAAQS occur as documented by previous
data. Additional discussion on the proce
dures for siting ozone stations may be found
in reference 4.
2.6 Nitrogen Dioxide (NO,) Design Crite
ria for SLAMS
The typical spatial scales of representa-
tiveness associated with nitrogen dioxide
monitoring based on monitoring objectives
are middle, neighborhood, and urban. Since
nitrogen dioxide is primarily formed in the
atmosphere from the oxidation of NO, large
volumes of air and mixing times usually
reduce the importance of monitoring on
small scale spatial variability especially for
long averaging times. However, there may
be some situations where NO, measure-
ments would be made on the middle scale
for both long- and short-term averages.
• Middle Scale.— Measurements on this
scale would cover dimensions from about
100 meters to 0.5 kilometer. These measure-
ments would characterize the public expo-
sure to NO, in populated areas. Also moni-
tors that are located closer to roadways
than the minimum distances specified in
Table 3 of Appendix E of this part, would be
represented by measurements on this scale.
• Neighborhood and Urban Scales.— The
same considerations as discussed in Section
2.5 for O, would also apply to NO,.
After the spatial scale is selected based on
the monitoring objectives, then the siting
procedures as found in reference 4 should
be used to evaluate the adequacy of each ex-
isting NO, station and must be used to relo-
cate an existing station or to locate any new
NOi SLAMS stations. The siting procedures
begin with collecting the background mate-
rial. This background information may in-
clude the characteristics of the area and its
sources under study, climatological data to
determine where concentration maxima are
most likely to be found, and any existing
monitoring data for NO,
For neighborhood or urban scales, the em-
phasis in site selection will be in finding
those areas where long-term averages are
expected to be the highest. Nevertheless, it
should be expected that the maximum NO,
concentrations will occur in approximately
the same locations as the maximum total
oxides of nitrogen concentrations. The best
course would be to locate the station some
what further downwind beyond the expect-
ed point of maximum total oxides of nitro-
gen to allow more time for the formation of
NO,. The dilution of the emissions further
downwind from the source should be consid-
ered along with the need for reaction time
for NO, formation in locating stations to
measure peak concentration. If dispersion is
favorable, maximum concentrations may
occur closer to the emission sources than
the locations predicted from oxidation of
NO to NO, alone. This will occur downwind
of sources based on winter wind direction or
in areas where there are high ozone concen-
trations and high density NO, emissions
such as on the fringe of the central business
district or further downwind. The distance
and direction downwind would be based on
ozone season wind patterns.
Once the major emissions areas and wind
patterns are known, areas of potential maxi-
mum NO, levels can be determined. Nitro-
gen dioxide concentrations are likely to de-
cline rather rapidly outside the urban area.
Therefore, the best location for measuring
NO, concentrations will be in neighbor-
hoods near the edge of the city.
3. NETWORK DESIGN FOR NATIONAL AIR
MONITORING STATIONS (NAMS)
The NAMS must be stations selected from
the SLAMS network with emphasis given to
urban and multisource areas. Areas to be
monitored must be selected based on urban-
ized population and pollutant concentration
levels. Generally, a larger number of NAMS
are needed in more polluted urban and
multisource areas. The network design crite-
ria discussed below reflect these concepts.
However it should be emphasized that devi-
ations from the NAMS network design crite-
ria may be necessary in a few cases. Thus,
these design criteria are not a set of rigid
rules but rather a guide for achieving a
proper distribution of monitoring sites on a
national scale.
The primary objective- for NAMS is to
monitor in the areas where the pollutant
concentration and the population exposure
are expected to be the highest consistent
with the averaging time of the NAAQS. Ac-
cordingly, the NAMS fall into two catego-
ries:
Category (a): Stations located in the
area(s) of expected maximum concentra-
tions (generally neighborhood scale, except
micro scale for CO and urban scale for O,):
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Chapter I—Environmental Protection Agency
Title 40—Protection of Environment
APR. D
Category (b): Stations which combine
poor air quality with a high population den-
sity but not necessarily located in an area of
expected maximum concentrations (neigh-
borhood scale, except urban scale for NO,).
Category (b) monitors would generally be
representative of larger spatial scales than
category (a) monitors.
For each urban area where NAMS are re-
quired, both categories of monitoring sta-
tions must be established. In the case of
TSP and SO, if only one NAMS is needed.
then category (a) must be used. The analy-
sis and interpretation of data from NAMS
should consider the distinction between
these types of stations as appropriate.
The concept of NAMS is designed to pro-
vide data for national policy analyses/
trends and for reporting to the public on
major metropolitan areas. It is not the
intent to monitor in every area where the
NAAQS are violated. On the other hand,
the data from SLAMS should be used pri-
marily for nonattainment decisions/ analy-
ses in specific geographical areas. Since the
NAMS are stations from the SLAMS net-
work, station locating procedures for NAMS
are part of the SLAMS network design proc-
ess.
3.3 Carbon Monoxide (CO) Design Crite-
ria for NAMS
Information is needed on ambient CO
levels in major urbanized areas where CO
levels have been shown or inferred to be a
significant concern. At the national level.
EPA will not routinely require data from as
many stations as are required for TSP. and
perhaps. SO,, since CO trend stations are
principally needed to assess the overall air
quality progress resulting from the emission
controls required by the Federal motor vehi-
cle control program (FMVCP).
Although State and local air programs
may require extensive monitoring to docu-
ment and measure the local impacts of CO
emissions and emission controls, an ade-
quate national perspective is possible with
as few as two statioas per major urban area.
The two categories for which CO NAMS
would be required ere: (a) Peak concentra-
tion areas such as are found around major
traffic arteries and near heavily traveled
streets in downtown areas (micro scale): and
(b) neighborhoods where concentration ex-
posures are significant (neighborhood
scale).
The peak concentration station (micro
scale) is usually found near heavily traveled
downtown streets (street canyons), but
could be found along major arterials (corri-
dors), either near intersections or at low ele-
vations which are influenced by duwnslope
drainage patterns under low inversion con-
ditions. The peak concentration station
should be located so that it is representative
of several similar source configurations in
the urban area, where the general popula-
tion has access. Thus, it should reflect one
of many potential peak situations which
occur throughout the urban area. It is rec-
ognized that this does not measure air qual-
ity which represents large geographical
areas. Thus, a second type of station on the
neighborhood scale is necessary to provide
data representative of the high concentra-
tion levels which exist over large geographi-
cal areas.
The neighborhood station (neighborhood
scale) should be located in areas with a
stable, high population density, projected
continuity of neighborhood character, and
high traffic density. The stations should be
located where no major zoning changes, new
highways, or new shopping centers are
being considered. The station should be
where a significant CO pollution problem
exists, but not be under the influence of any
one line source. Rather, it should be more
representative of the overall effect of the
sources in a significant portion of the urban
area.
Because CO is generally associated with
heavy traffic and population clusters, an ur-
banized area with a population greater than
500,000 is the principal critertion for identi-
fying the urban areas for which pairs of
NAMS for this pollutant will be required.
The criterion is based on judgment that sta-
tions in urban areas with greater than
500.000 population would provide sufficient
data for national analysis and national re-
porting to Congress and the public. Also, it
has generally been shown that major CO
problems are found in areas greater than
500.000 population.
3.4 Ozone (O,) Design Criteria for NAMS
The criterion for selecting locations for
ozone NAMS is any urbanized area having a
population of more than 200,000. This popu-
lation cut off is used since the sources of hy-
drocarbons are both mobile and stationary
and are more diverse. Also, because of local
and national control strategies and the com-
plex chemical process of ozone formation
and transport, more sampling stations than
for CO are needed on a national scale to
better understand the ozone problem. This
selection criterion is based entirely on popu-
lation and will include those relatively
highly populated areas where most of the
oxidant precursors originate.
Each urban area will generally require
only two ozone NAMS. One station would be
representative of maximum ozone concen-
trations (category (a), urban scale) under
the wind transport conditions as discussed
in section 2.5. The exact location should bal-
ance local factors affecting transport and
buildup of peak O, levels with the need to
represent population exposure. The second
station (category (b). neighborhood scale).
should be representative of high density
population areas on the fringes of the cen-
tral business district along the predominant
summer/fall daytime wind direction. This
latter station should measure peak O, levels
under light and variable or stagnant wind
conditions. Two ozone NAMS stations will
be sufficient in most urban areas since spa-
tial gradients for ozone generally are not as
sharp as for other criteria pollutants.
3.5 Nitrogen Dioxide (NO,) Criteria for
NAMS
Nitrogen dioxide NAMS will be required
in those areas of the country which have a
population greater than 1.000,000. These
areas will have two NO, NAMS. It is felt
that stations in these major metropolitan
areas would provide sufficient data for a na-
tional analysis of the data, and also because
NO, problems occur in areas of greater than
1.000.000 population
Within urban art as requiring NAMS. two
permanent monitor.; are sufficient. The first
station (category (a) neighborhood scale)
would be to measure the photochemical pro-
duction of NO, and would best be located in
that part of the urban area where the emis-
sion density of NO, is the highest. The
second station (category (b) urban scale),
would be to measure the NO, produced from
the reaction ot NO with O, and should be
downwind of the area of peak NO, emission
areas.
4. SUMMARY
Table 4 shows by pollutant, all 01 the spa-
tial scales that are applicable for SLAMS
and the required spatial scales for NAMS.
There may also be some situations, as dis-
cussed later in Appendix E, where addition-
al scales may be allowed for NAMS pur-
poses.
Table 4—Summary of Spatial Scales for SLAMS and Required Scales for NAMS
Spatial
scale
Micro
Middle
Neighborhooc
Urban
Regional
icales applicable for SLAMJ
TSP
/
/
/
/
so2
/
/
/
/
CO
/
/
/
°3
/
/
/
/
N02
/
/
/
Scales required for NAMS
TSP
/
so2
/
CO
/
/
°3
/
/
N02
/
/
Figure 5-2. Paniculate field data.
5. REFERENCES
1. Ludwig. F. L., J. H. S. Kealoha, and E.
Shelar. Selecting Sites for Monitoring Total
Suspended Particulates. Stanford Research
Institute. Menlo Park. CA. Prepared for
U.S. Environmental Protection Agency, Re-
search Triangle Park. NC. EPA Publication
No. EPA-450/3-77-018. June 1977. revised
December 1977.
2. Ball. R. J. and G. E. Anderson. Opti-
mum Site Exposure Criteria for SO, Moni-
toring. The Center for the Environment and
Man. Inc.. Hartford, CT. Prepared for U.S.
Environmental Protection Agency. Re-
search Triangle Park, NC. EPA Publication
No. EPA-450/H-77-013. April 1977.
3. Ludwig. F. L. and J. H. S. Kealoha. Se-
lecting Sites for Carbon Monoxide Monitor-
ing. Stanford Research Institute. Menlo
Park. CA. Prepared for U.S. Environmental
Protection Agency. Research Triangle Park,
NC. EPA Publication No. EPA-450/3-75-
077. September 1975.
6-7
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Chapter I—Environmental Protection Agency
Title 40—Protection of Environment
App. E
4 Ludwig, F. L. and E. Shclar. Site Select
ing for the Monitoring of Photochemical
Air Pollutants. Stanford Research Institute.
Menlo Park. CA. Prepared for U.S. Environ-
mental Protection Agency, Research Trian
gle Park. NC EPA Publication No. EPA-
450/3 78-013. April 1978.
5. Guideline on Air Quality Models.
OAQPS, U.S. Environmental Protection
Agency. Research Triangle Park. NC
OAQPS No. 1.2-080. April 1978.
[44 FR 27571. May 10. 1979: 44 FR 72592.
Dec. 14. 19791
APPENDIX E—PROBE SITING CRITERIA FOR
AMBIENT AIR QUALITY MONITORING
1. Introduction
2. Total Suspended Participates (TSPi
2.1 Vertical Placement
2.2 Spacing from Obstructions
2.3 Spacing from Roadways
2.4 Other Considerations
3. Sulfur Dioxide
3.1 Horizontal and Vertical Probe Place-
ment
3.2 Spacing from Obstructions
4. Carbon Monoxide 'CO)
4.1 Horizontal and Vertical Probe Place-
ment
4.2 Spacing from Obstructions
4.3 Spacing from Roads
5. Ozone (O,l
5.1 Vertical and Horizontal Probe Place-
ment
5.2 Spacing from Obstructions
5.3 Spacing from Roads
6, Nitrogen Dioxide iNO,>
6.1 Vertical and Horizontal Probe Place-
ment
6.2 Spacing from Obstructions
6,3 Spacing from Roads
7. Probe Material and Pollutant Sample
Residence Time
8. Waiver Provisions
9. Discussion and Summary
10. References
1 INTRODUCTION
This appendix contains probe siting crite-
ria to be applied to ambient air quality mon-
itors or monitor probes after the genera;
station location has been selected based on
the monitoring objectives and spatial scale
of representativeness as discussed in Appen-
dix D of this part. Adherence to these siting
criteria is necessary to ensure the uniform
collection of compatible and comparable air
quality data.
The probe siting criteria as discussed
below must be followed to the maximum
extent possible. It is recognized that there
may be situations when the probe siting cri-
teria cannot be followed. If the siting crite-
ria cannot be met, this must be thoroughly
documented with a written request for a
waiver which describes how and why the
siting criteria differs. This documentation
should help to avoid later questions about
the data. Conditions under which EPA
would consider an application for waiver
from these siting criteria are discussed in
Section 8 of this appendix.
The spatial scales of representativeness
used in this appendix, i.e., micro, middle.
neighborhood, urban, and regional are de-
fined and discussed in Appendix D of this
part. The pollutant specific probe siting cri-
teria generally apply to all spatial scales
except where noted otherwise. Specific
siting criteria that are prefaced with a
"must' are defined as a requirement and ex-
ceptions must be approved through the
waiver provisions. However, siting criteria
that are prefaced with a "should" are de-
fined as a goal to moot for consistency but
are not a requirement
4. CARBON MONOXIDE (CO)
4.1 Horizontal a,id Vertical Probe Place-
ment
Because of the importance of measuring
population exposure to CO concentrations,
air should be sampled at average breathing
heights. However, practical factors require
that the inlet probe be higher. The required
height of the inlet probe for CO monitoring
is therefore 3±'/2 meter for a microscale
site, which is a compromise between repre-
sentative breathing height and prevention
of vandalism. The recommended 1 meter
range of heights is also a compromise to
some extent. For consistency and compara-
bility, it would be desirable to have all inlets
at exactly the same height, but practical
considerations often prevent this. Some rea-
sonable range must be specified and 1 meter
provides adequate leeway to meet most re-
quirements.
For the middle and neighborhood scale
stations the vertical concentration gradi-
ents are not as great as for the microscale
station. This is because the diffusion from
roads is greater and the concentrations
would represent larger areas than for the
microscale. Therefore, 'he required height
of the inlet probe is 3 to 15 meters for
middle and neighborhood scale stations.
The inlet probe must be located more than
1 meter in the vertical or horizontal direc-
tion from any supporting structuie.
4.2 Spacing from Obstructions
Airflow must also be unrestricted in an arc
of at least 270' around the inlet probe, and
the predominant wind direction for the
season of greatest pollutant concentration
potential must be included in the 270' arc. If
the probe is located on the side of a build-
ing. 180° clearance is required.
4.3 Spacing from Roads
Street canyon and traffic corridor stations
(microscale) are intended to provide a mea-
surement of the influence of the immediate
source on the pollution exposure of the pop
ulation. In order to provide some reasonable
consistency and comparability in the air
quality data from such stations, a minimum
distance of 2 meters and a maximum dis-
tance of 10 meters from the edge of the
nearest traffic lane must be maintained for
these CO monitor inlet probes. This should
give consistency to the data, yet still allow
flexibility of finding suitable locations.
Street canyon/corridor (microscale) inlet
probes must be located at least 10 meters
from an intersection and preferably at a
midblock location. Midblock locations are
preferable to intersection locations because
intersections represent a much smaller por-
tion of downtown space than do the streets
between them. Pedestrian exposure is prob-
ably also greater in street canyon/corridors
than at intersections. Finally, the practical
difficulty of positioning sampling inlets is
less at midblock locations than at the inter-
section.
In determining the minimum separation
between a neighborhood scale monitoring
station and a specific line source, the pre-
sumption is made that measurements
should not be unduly influenced by any one
roadway. Computations were made to deter-
mine the separation distances, and table 1
provides the required minimum separation
distance between roadways and neighbor-
hood scale stations. Sampling stations that
are located closer to roads than this crite-
rion allows should not be classified as a
neighborhood scale, since the measurements
from such a station would closely represent
the middle scale. Therefore, stations not
meeting this criterion should be classified as
middle scale. In some cases, such a monitor-
ing station would be acceptable for SLAMS
purposes, but not NAMS since no middle
scale NAMS stations are required. Addition-
al information on CO probe siting may be
found in reference 12.
TABLE 1— Minimum separation distance be-
tween neighborhood scale CO stations
and roadways
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Chapter I—Environmental Protection Agency
Title 40—Protection of Environment
App. E
dilations using the methodology in refer-
ence 13 and validated using more recent am-
bient data collected near a major roadway
Sampling stations that are located closer to
roads than this criterion allows should not
be classified as neighborhood or urban scale.
since the measurements from such stations
would more closely represent the middle
scale. Accordingly, such stations should be
classified as middle scale. In some cases, a
middle scale station would be acceptable for
SLAMS purposes, but not for NAMS since
no middle scale NAMS are required. The
minimum separation distance must also be
maintained between an ozone station and
other similar volumes of automotive traffic.
such as parking lots. Additional information
on ozone probe siting criteria may be found
in reference 13.
TABLE 2—Minimum separation distance be-
tween neighborhood and urban scale
ozone stations and roadways (edge of
nearest traffic lane)
Roadway average daily
traffic, vehicles per day
^ 10.000
15,000
20.000
40.000
70.000
- 110.000
Minimum separation distance
between roadways and
stations, meters
jlO-
20
30
50
100
..250
• Distances should be interpolated cased on traffic flow
6. NITROGEN DIOXIDE (NO,)
6.1 Vertical and Horizontal Probe Place-
ment
The height of the NO, inlet probe must be
3 to 15 meters above the ground. This Is a
compromise between measuring in the
breathing zone and avoidance of vandalism.
finding suitable sites, etc. For NO,, the
height does not appear to be a critical factor
since the NO, should be fairly well mixed
and somewhat uniform in the vertical direc-
tion. The distance of the inlet probe from
any supporting structure must be greater
than 1 meter vertically or horizontally.
6.2 Spacing from Obstructions
Buildings, trees, and other obstacles ma>
possibly scavenge NO, In order to avoid this
kind of interference, the station must be lo-
cated well away from such obstacles so that
the distance between obstacles and the inlet
probe is at least twice the height that the
obstacle protrudes above the probe. Sam-
pling stations that are located closer to ob-
stacles than this criterion allows should not
be classified in the neighborhood or urban
scales, since the measurements from such
stations would more closely represent the
middle scale. Such stations should be classi-
fied as middle scale. For similar reasons, a
probe inlet along a vertical wall is undesira-
ble because air moving along that wall may
be subject to possible removal mechanisms.
The inlet probe should also be at least 20
meters from trees. There must be unres-
tricted airflow in an arc of at least 210'
around the inlet probe, and the predomi-
nant wind direction for the season of great-
est pollutant concentration potential must
be included in the 270' arc. If the probe is
located on the side of the building, 180'
clearance is required.
6.3 Spacing from Roads
It is important that the monitoring probe
be removed from oxides of nitrogen sources
to avoid measurements being dominated by
any one source and to allow time for conver-
sion (reactions) of NO emissions to NO,.
Further, the effects of roadway sources
must be minimized by using separation dis-
tances for neighborhood and urban scale
stations found in Table 3. These distances
were based on recalculations using the
methodology in reference 13 and validated
using more recent ambient data collected
near a major roadway. The minimum sepa-
ration distance must also be maintained be-
tween an NO, probe and any other similar
volume of automotive traffic such as park-
ing lots. Sampling stations that are located
closer to roads than this criterion allows
should not generally be classified as neigh-
borhood or urban scales, since the measure-
ments from such stations would more close-
ly represent middle scale stations. Such sta-
tions should generally be classified as
middle scale. In some cases, such a monitor-
Ing station would be acceptable for SLAMS
purposes, but not for NAMS since no middle
scale NAMS are acceptable. Additional in-
formation on NO, probe siting criteria may
be found in reference 13.
TABLE 3—Minimum separation distance be-
tween neighborhood and urban scale
NO, stations and roadways (edge of
nearest traffic lane)
Roadway average daily Minimurr. separation distance
traffic, vehicles per day between roadways and station
meters
OO.OOC
15.000
20.000
40.000
70,000
O10.000
.•10-
20
30
50
100
,250
• Distances should be interpolated based on traffic flow
7. PROBE MATERIAL AND POLLUTANT SAMPLE
RESIDENCE TIME
For the reactive gases, SO,, NO,, and O,.
special probe material must be used. Stud-
ies """ have been conducted to determine
the suitability of materials such as polypro-
pylene, polyethylene, polyvinylchloride.
tygon, aluminum, brass, stainless steel.
copper, pyrex glass and teflon fo' use as
intake sampling lines. Of the above materi-
als, only pyrex glass and teflon have been
found to be acceptable for use as intake
sampling lines for all the reactive gaseous
pollutants. Furthermore, EPA" has speci-
fied borosilicate glass or PEP teflon as the
only acceptable probe materials for deliver-
ing test atmospheres in the determination
of reference or equivalent methods. There-
fore, borosilicate glass. FEP teflon, or their
equivalent must be used for existing and
new NAMS or SLAMS.
No matter how nonreactive the sampling
probe material is Initially, after a period of
use reactive particulate matter is deposited
on the probe walls. Therefore, the time it
takes the gas to transfer from the probe
inlet to the sampling device is also critical.
Ozone in the presence of NO will show sig-
nificant losses even in the most inert probe
material when the residence time exceeds 20
seconds.10 Other studies"-" indicate that a
10-second or less residence time is easily
achievable. Therefore, sampling probes for
reactive gas monitors at SLAMS or NAMS
must have a sample residence time less than
20 seconds.
8. WAIVER PROVISIONS
It is believed that most sampling probes or
monitors can be located so that they meet
'he requirements of this appendix. New sta-
tions with rare exceptions, can be located
within the limits of this appendix. However,
some existing stations may not meet these
requirements and yet still produce useful
data for some purposes. EPA will consider a
written request from the State Agency to
waive one or more siting criteria for some
monitoring stations providing that the State
can adequately demonstrate the need (pur-
pose) for monitoring or establishing a moni-
toring station at that location. For estab-
lishing a new station, a waiver may be
granted only if both of the following crite-
ria are met:
• The site can be demonstrated to be as
representative of the monitoring area as it
would be if the siting criteria were being
met.
• The monitor or probe cannot reasonably
be located so as to meet the siting criteria
because of physical constraints (e.g., inabil-
ity to locate the required type of station the
necessary distance from roadways or ob-
structions).
However, for an existing station, a waiver
may be granted if either of the above crite-
ria are met.
Cost benefits, historical trends, and other
factors may be used to add support to the
above, however, they in themselves, will not
be acceptable reasons for granting a waiver.
Written requests for waivers must be sub-
mitted to the Regional Administrator. For
those SLAMS also designated as NAMS, the
request will be forwarded to the Administra-
tor.
9. DISCUSSION AND SUMMARY
Table 4. presents a summary of the re-
quirements for probe siting criteria with re-
spect to distances and heights. It is appar-
ent from Table 4 that different elevation
distances above the ground are shown for
the various pollutants. The discussion in the
text for each of the pollutants described
reasons for elevatir g the monitor or probe.
The differences in the specified range of
heights are based on the vertical concentra-
tion gradients. For CO, the gradients in the
vertical direction are very large for the mi-
croscale. so a small range of heights has
been specified. For SO,, NO,, TSP, and O,
(except near roadways), the vertical gradi-
ents are smaller and thus a larger range of
heights can be used. The upper limit of 15
meters was specified for consistency be-
tween pollutants and to allow the use of a
single manifold for monitoring more than
one pollutant.
dix.
' See References at end of this Appen
" See References at end of this Appendix.
10 See References at end of this Appendix.
""" See References at end of this Appen-
dix.
6-9
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Chapter I—Environmental Protection Agency
Title 40—Protection of Environment
APR. E
Pollutant
TSP
S0j
°3
"°2
All
All
Middle
All
All
Height above
1 - 15
3 - 15
J - 15
3 - 15
at cuctu
> 1
> 1
> 1
re. •« t e r •
» 2
> 1
> 1
> I
Other ep«c ing criteria
1. Should b* >20 B«ter« f row tree*.
2. Distance fro* sampler to obstacle, such as buildings, s>uet b« .
) . Hint have unrestricted airflow 270* around the saa.pl er .
1. Should b* >20 Mtera fro* trees.
If probe Is on the tide of a building.
probe IB on the aide of r building.
«t l«a*t tvlre the height the obstacle protrude* above the lnl«t probe.
3. Hu,ft have unrestricted airflow 270* around th* Inlet probe, or 180*
If probe 1« on the side of • building.
1. Should b* >20 SMters from tract.
*t least twice the height the obstacle protrude* above the Inlet probe. **
3. Muit hav* unrestricted airflow 270" around the Inlet probe, or 180"
1 f probe It on the aide of a build Ing.
Ohm probe !• located on rooftop, thla separation dlec«ace it In reference to walls, parapets, or penthouees located on the roof.
t,
Sites not netting thist criterion would be classified as Middle acale leee lejct).
Distance la dependent on height of furnace or Incineration flue, type of fuel or waate burned, and quality of fuel (eulfur and ash content).
TM« Is to avoid undue Influencea from Minor pollutant aourcee.
REFERENCES
1 Bryan. R.J.. R.J. Gordon, and H.
Menck. Comparison of High Volume Air
Filter Samples at Varying Distances from
Los Ange.es Freeway. University of South-
ern California. School of Medicine, Los An-
geles, CA. (Presented at 66th Annual Meet
ing of Air Pollution Control Association.
Chicago. IL.. June 24-28, 1973. APCA 73-
158.)
2. Teer. E.H. Atmospheric Lead Concen-
tration Above an Urban StreeU. Master of
Science Thesis, Washington University. St.
Louis, MO. January 1971.
3 Bradway, R.M., F.A. Record, and W.E.
Belanger. Monitoring and Modeling of Re-
suspended Roadway Dust Near Urban Ar
terials. OCA Technology Division. Bedford.
MA. (Presented at 1978 Annual Meeting of
Transportation Research Board, Washing-
ton, DC. January 1978.)
4. Pace, T.G., W.P. Preas, and E.M. Afify.
Quantification of Relationship Between
Monitor Height and Measured Participate
Levels in Seven U.S. Urban Areas. U.S Envi-
ronmental Protection Agency, Research Tri
angle Park, NC. (Presented at 70th Annual
Meeting of Air Pollution Control Associ-
ation, Toronto, Canada, June 20-24, 1977
APCA 77-13.4.)
5. Harrison, P.R. Considerations for Siting
Air Quality Monitors in Urban Areas. City
of Chicago, Department of Environmental
Control, Chicago. IL. (Presented at 66th
Annual Meeting of Air Pollution Control
Association, Chicago, IL., June 24-28. 1973
APCA 73-161.)
6 Study of Suspended Particulate Mea-
surements at Varying Heights Above
Ground. Texas State Department of Health.
Air Control Section, Austin, TX. 1970. p.7.
7. Rodes. C.E. and G.F. Evans. Summary
of LACS Integrated Pollutant Data. In: Los
Angeles Catalyst Study Symposium. U.S.
Environmental Protection Agency. Re
search Triangle Park, NC. EPA Publication
No. EPA-600/4-77-034. June 1977.
. 8. Lynn, D.A. et. al. National Assessment
of the Urban Particulate Problem: Volume
1, National Assessment. GCA Technology
Division/Bedford, MA. U.S. Environmental
Protection Agency. Research Triangle Park.
NC. EPA Publication No. EPA-450/3-75-
024. June 1976.
9. Pace, T.G. Impact of Vehicle-Related
Participates on TSP Concentrations and
Rationale for Siting Hi-Vols in the Vicinity
of Roadways. OAQPS. U.S. Environmental
Protection Agency, Research Triangle Park,
NC April 1978.
10 Ludwig, F.L.. J.H. Kealoha. and E.
Shelar. Selecting Sites for Monitoring Total
Suspended Particulates. Stanford Research
Institute. Menlo Park. CA. Prepared for
U.S. Environmental Protection Agency, Re-
search Triangle Park. NC. EPA Publication
No. EPA-450/3-77-018. June 1977. revised
December 1977.
11. Ball, R.J. and G.E. Anderson. Opti-
mum Site Exposure Criteria for SO, Moni-
toring. The Center for the Environment and
Man, Inc., Hartford, CT. Prepared for U.S.
Environmental Protection Agency, Re-
search Triangle Park. NC. EPA Publication
No. EPA 450'3-77-013 April 1977.
12. Ludwig. F.L. and J.H.S. Kealoha. Se-
lecting Sites for Carbon Monoxide Monitor-
ing. Stanford Research Institute, Menlo
Park, CA. Prepared for U.S. Environmental
Protection Agency. Research Park, NC. EPA
Publication No EPA-450/3-75-077. Septem-
ber 1975.
13. Ludwig. F.L and E. Shelar. Site Selec-
tion for the Monitoring of Photochemical
Air Pollutants. Star ford Research Institute.
Menlo Park. CA. Prepared for U.S. Environ-
mental Protection Agency, Research Trian-
gle Park, NC. EPA Publication No. EPA-
150/3-78-013. April 1978.
14. Wechter, S.G. Preparation of Stable
Pollutant Gas Standards Using Treated Alu-
minum Cylinders. ASTM STP. 598.40-54
1976.
15. Wohlers. H.C.. H. Newstein and D.
Daunis. Carbon Monoxide and Sulfur Diox-
ide Adsorption On and Description From
Glass, Plastic and Metal Tubings. J. Air
Poll. Con. Assoc. 17:753, 1976.
16. Elfers, L.A. Field Operating Culde for
Automated Air Monitoring Equipment U S
NTIS. p. 202. 249. 1971.
17. Hughes. E.E. Development of Standard
Reference Material for Air Quality Mea-
surement. ISA Transactions. 14:281-291
1975.
18. Ahshuller. A.D. and A G. Wartburg.
The Interaction of Ozone with Plastic and
Metallic Materials in a Dynamic Flow
System. Intern. Jour. Air and Water Poll
4:70-78. 1961.
19. CFR Title 40 Part 53.22. July 1976.
6-10
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Chapter I—Environmental Protection Agency
Title 40—Protection of Environment
App. E
20 Butcher, S.S. and R.E. Ruff. Effect of
Inlet Residence Time on Analysis of Atmos-
pheric Nitrogen Oxides and Ozone, 43:1890,
1971.
21. Slowik. A.A. and E.B. Sansone. Diffu-
sion Losses of Sulfur Dioxide in Sampling
Manifolds J. Air. Poll. Con. Assoc.. 24:245,
1974.
22. Yamada. V.M. and R.J. Charlson.
Proper Sizing of the Sampling Inlet Line for
a Continuous Air Monitoring Station. Envi-
ron. Sci. and Technol.. 3:483, 1969.
[44 FR 27571, May 10. 1979; 44 PR 72592,
Dec. 14. 19791
6-11
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Excerpts of Ambient Monitoring Guidelines for Prevention of
Significant Deterioration (PSD) EPA 450/4-80-012
2. NETWORK DESIGN AND PROBE SITING CRITERIA
A source subject to PSD should only proceed with designing a PSD
monitoring network only after going through the procedure in Appendix A
to determine if monitoring data will be required. To fulfill that
requirement, a source may use representative air quality data which was
discussed in section 2.4 or monitor This section presents guidance to
be used if an applicant decides to monitor in lieu of using representative
air qua!ity data.
3.2 Network Design
The design of a network for criteria and noncn'teria pollutants
will be affected by many factors, such as topography, climatology,
population, and existing emission sources. Therefore, the ultimate
design of a network for PSD purposes must be decided on a case-by-case
basis by the permit granting authority. Section 3.2 discusses the
number and location of monitors for a PSD network. Additional guidance
on the general siting of the monitors may be found in references 6-9
which discuss highest concentration stations, isolated point sources,
effects of topography, etc. Probe siting criteria for the monitors are
discussed in section 3.3. The guidelines presented here should be followed
to the maximum extent practical in developing the final PSD monitoring
network.
3. 2 Number and Location of Monitors
The number and location of monitoring sites will be determined on a
case-by-case basis by the source owner or operator and reviewed by the
permit granting authority. Consideration should be given to the effects
of existing sources, terrain, meteorological conditions, existence of
fugitive or reentrained dusts, averaging time for the pollutant, etc.
Generally, the number of monitors will be higher where the expected
spatial variability of the pollutant in the area(s) of study is higher.
3.2.I Preconstruction Phase
Information obtained in the ambient air quality analysis in Appendix
A will be used to assist in determining the number and location of
monitors for the preconstruction phase. The air quality levels before
construction were determined by modeling or in conjunction with monitoring
data. The screening procedure (or more refined model) estimates were
determined in Appendix A.
6-12
-------
The source should first use the screening procedure or refined
model estimates to determine the general location(s) for the maximum air
quality concentrations from the proposed source or modification. Secondly,
the source should determine by modeling techniques the general location(s)
for the maximum air quality levels from existing sources. Thirdly, the
modeled pollutant contribution of the proposed source or modification
should be analyzed in conjunction with the modeled results for existing
sources to determine the maximum impact area. Application of these
models must be consistent with EPA's "Guideline on Air Quality Models"
[34]. This would provide sufficient information for the applicant to
place a monitor at (a) the location(s) of the maximum concentration
increase expected from the proposed source or modification, (b) the
location(s) of the maximum air pollutant concentration from existing
sources of emissions, and (c) the location(s) of the maximum impact
area, i.e., where the maximum pollutant concentration would hypothetically
occur based on the combination effect of existing sources and the proposed
new source or modification. In some cases, two or more of these locations
may coincide and thereby reduce the number of monitoring stations.
Monitoring should then be conducted in or as close to these areas
as possible (also see discussion in seotior. 3.2.3}. Generally, one to
four sites would cover most situations in multisource settings. For
remote areas in which the permit granting authority has determined that
there are no significant existing sources, a minimum number of monitors
would be needed, i.e., one or probably two at the most. For new sources,
in these remote areas, as opposed to modifications, some concessions
will be made on the locations of these monitors. Since the maximum
impact from these new sources would be in remote areas, the monitors may
be located, based on convenience or accessibility, near the proposed new
source rather than near the maximum impact area since the existing air
quality would be essentially the same in both areas. However, the
maximum impact area is still the preferred location.
* * * * * * * For fugitive hydrocarbon emissions,
the applicant should locate a monitor downwind of the source at the
point of expected maximum ozone concentration contribution. This location
will be found downwind during conditions that are most conducive to
ozone formation, such as temperature above 20°C (68°F) and high solar
radiation intensity. For hydrocarbon emissions from a stack, the applicant
should also locate the monitor in the area of expected maximum ozone
concentration. For both fugitive and stack emissions, the selection of
areas of highest ozone concentrations will require wind speed and direction
data for periods of photochemical activity. Monitoring for ozone will
only be necessary during the seasons when high concentrations occur.
Since ozone is the result of a complex photochemical process, the
rate of movement across an area of the air mass containing precursors
should be considered. The distance from the proposed source to the
monitor for an urban situation should be about equal to the distance
traveled by the air moving for 5 to 7 hours at wind speeds occurring
during periods of photochemical activity. In an urban situation, ozone
formation over the initial few hours may be supressed by nitric oxide
(NO) emissions. For a point source, the NO interactions may be minimal,
and the travel time to the expected maximum ozone concentration may be 3
6-13
-------
to 4 hours downwind. In general, the downwind distance for the maximum
ozone site should generally not be more than 15 to 20 miles from the
source because a lower wind speed (2-3 miles per hour) with less dilution
would be a more critical case. Additionally, the frequency that the
wind would blow from the source over the site diminishes with increasing
distances.
.5. .9..': Postconstruction Phase
As discussed above for preconstruction monitoring, appropriate dis-
persion modeling techniques are used to estimate the location of the
air quality impact of the new source or modification. Monitors should
then be placed at (a) the expected area of the maximum concentration
from the new source or modification, and (b) the maximum impact area(s),
i.e., where the maximum pollutant concentration will occur based on the
combined effect of existing sources and the new source or modification.
It should be noted that locations for these monitors may be different
from those sites for the preconstruction phase due to other new sources
or modifications in the area since the preconstruction monitoring.
Generally, two to three sites would be sufficient for most situations
in multisource areas. In remote areas where there are no significant
existing sources, one or two sites would be sufficient. These sites
would be placed at the locations indicated from the model results. The
same concerns discussed in section 3.2.2 regarding industrial process
fugitive particulate emissions, fugitive hydrocarbon emissions, and
ozone monitoring would also be applicable for the postconstruction
phase.
3. 2. 3 Special Concerns for Location of Monitors
For the preconstruction and postconstruction phases, modeling is
used to determine the general area where monitors would be located. Some
of the modeled locations may be within the confines of the source's
boundary. However, monitors should be placed in those locations satisfying
the definition of ambient air. Ambient air is defined in 40 CFR 50.1(e)
as "that portion of the atmosphere, external to buildings, to which the
general public has access." Therefore, if the modeled locations are
within an area excluded from ambient air, the monitors should be located
downwind at the boundary of that area.
In some cases, it is simply not practical to place monitors at the
indicated mode'ied locations. Some examples may include over open bodies
of water, on rivers, swamps, cliffs, etc. The source and the permit
granting authority should determine on a case-by-case basis alternative
locations.
3. 3 Probe Siting Criteria
The desire for comparability in monitoring data requires adherence
to some consistent set of guidelines. Therefore, the probe siting
criteria discussed below must be followed to the maximum extent possible
to ensure uniform collection of air quality data that are comparable and
compatible.
6-14
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Before proceeding with the discussion of pollutant specific probe
siting criteria, it is important to expand on the discussion in section
3.2 of the location of monitors. In particular, reference is made to
two monitoring objectives.
• Case 1: Locating monitors to determine the maximum concentration
from the proposed source and/or existing sources.
• Case 2: Locating monitors to determine where the combined
impact of the proposed source and existing sources
would be expected to exhibit the highest concentrations.
For Case 1, the driving force for locating the siting area of the
monitor as well as the specific location of the probe or instrument
shelter is the objective of measuring the maximum impact from the proposed
source. Two Case 1 examples are given. Consider the first situation in
which a proposed source would be emitting pollutants from an elevated
stack. Under these circumstances, sufficient mixing generally occurs
during the transport of the emissions from the stack to the ground
resulting in small vertical gradients near ground level, thus, a wide
range of probe heights, 3-15 meters for gases and 2-15 meters for particulates
is acceptable. For the same objective (maximum concentration from
proposed source), consider the second example in which pollutants would
be emitted from a ground level source. In this case, the concentration
gradient near the ground can be large, thereby requiring a much tighter
range of acceptable probe heights. For ground level sources emitting
pollutants with steep vertical concentration gradients, efforts should
be made to locate the inlet probe for gaseous pollutant monitors as
close to 3 meters (a reasonable practical representation of the breathing
zone) as possible and for particulate monitors using the hi-volume
sampler 2 to 7 meters above ground level. The rationale for the 3
meters is that for gaseous pollutant measurements, the inlet probe can
be adjusted for various heights even though the monitor is located in a
building or trailer. Conversely, the 2-3 meter height for the hi-
volume sampler placement is not practical in certain areas. The 7 meter
height allows for placement on a one story building and is reasonably
close to representing the breathing zone.
Turn now to the second monitoring objective, Case 2, which is
locating monitors to determine the maximum impact area taking into
consideration the proposed source as well as existing sources. The
critical element to keep in mind in locating a monitor to satisfy this
objective is that the intent is to maximize the combined effect. Thus,
in one circumstance, the existing source might contribute the largest
impact. The importance of the above discussion to the topic of probe
siting criteria is that in attempting to locate a monitor to achieve
this objective, the placement of the probe or instrument shelter can
vary depending upon which source is the predominant influence on the
maximum impact area. As an extreme example, consider the situation
where a proposed elevated source would emit CO into an urban area and
have maximum combined CO impact coincident to an area adjacent to a
heavily traveled traffic corridor. It is known that traffic along
corridors emit CO in fairly steep concentration gradients so the placement
of the probe to measure the areas of highest CO concentration can vary
significantly with probe height as well as distance frdm the corridor.
6-15
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In this example, the traffic corridor has the major influence on the
combined impact and therefore controls the probe placement. As noted in
the CO probe siting criteria in section 3.3.3 as well as Appendix E of
the May 10, 1979 Federal Register promulgation of the Ambient Air Monitoring
Regulations [10], the required probe height in such microscale cases is
given as 3^1/2 meters while the distance of the probe from the roadway
would be between 2 and 10 meters.
As another example, consider the case where the same proposed CO
source would emit CO at elevated heights and have a combined maximum CO
impact in an urban area that is only slightly affected by CO emissions
from a roadway. The combined impact area in this case is far enough
away from the two sources to provide adequate mixing and only small
vertical concentration gradients at the impact area. In this case, the
acceptable probe height would be in the range of 3-15 meters.
It is recognized that there may be other situations occurring which
prevent the probe siting criteria from being followed. If so, the
differences must be thoroughly documented. This documentation should
minimize future questions about the data.
6-16
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Review Exercise
Now that you've completed the assignment for Section 6, please answer the fol-
lowing questions. These will help you determine whether or not you are mastering
the material.
1. Which of the following is(are) a basic monitoring objective(s) of a SLAMS
network?
a. determination of the highest air pollutant concentrations that are expected
to occur in the area covered by the network
b. determination of representative air pollutant concentrations in areas of high
population density
c. determination of the impact on air pollution levels of significant sources or
source categories
d. determination of general background air pollutant concentration levels
e. all of the above
2. True or False? The number of monitoring stations required for a SLAMS net-
work is specified in Appendix D of 40 CFR 58.
Match each of the following SLAMS monitoring objectives with its appropriate type
of monitoring site. (Questions 3-6)
3. determination of the highest air a. neighborhood and regional
pollutant concentrations that
are expected to occur in the
area covered by the network
4. determination of representative b. neighborhood and urban
air pollutant concentrations in
areas of high population density
5. determination of the impact on c. micro-, middle, and neighborhood
air pollution levels of significant
sources or source categories
6. determination of general back- d. micro-, middle, neighborhood,
ground air pollutant concen- and urban
tration levels
7. True or False? The primary monitoring objective of NAMS is to monitor in
areas where pollutant concentrations and population exposure are expected to
be the highest consistent with the averaging times of the National Ambient Air
Quality Standards.
6-17
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8. Which of the following is(are) a NAMS category(ies)?
a. monitoring stations located in areas of expected maximum pollutant
concentrations
b. monitoring stations located in areas of combined poor air quality and high
population density
c. both a and b, above
d. none of the above
9. Which of the following is(are) a primary use(s) of NAMS data?
a. analyzing national policy and trends
b. reporting air quality information concerning major metropolitan areas to
the public
c. both a and b, above
d. none of the above
For each of questions 10-12, match the specified pollutant with its appropriate
SLAMS spatial scales of representativeness.
10. CO a. micro-, middle, neighborhood
11. O3 b. middle, neighborhood, urban, regional
12. NO2 c. middle, neighborhood, urban
13. In general, urbanized areas having populations greater than v) are
required to have at least v) CO NAMS.
a. 200,000; 1
b. 500,000; 2
c. 500,000; 3
d. 1,000,000; 2
14. In general, urbanized areas having populations greater than v) are
required to have at least v) Os NAMS.
a. 200,000; 2
b. 500,000; 2
c. 500,000; 3
d. 1,000,000; 2
15. Urbanized areas having populations greater than (•) are required to
have (?) NO2 NAMS.
a. 200,000; 2
b. 500,000; 2
c. 500,000; 3
d. 1,000,000; 2
For each of questions 16-18, match the specified pollutant with its required NAMS
spatial scales of representativeness.
16. CO a. micro-, neighborhood
17. Os b. neighborhood, urban
18. NO2
6-18
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For each of questions 19-26, select the CO SLAMS/NAMS siting criterion specified
in Appendix E of 40 CFR 58 for the specified parameter.
19. For microscale sites, height range of CO monitor's inlet probe above
ground level (meters):
a. 1 to 3
b. 2.5 to 3.5
c. 2 to 10
4. 3 to 15
20. Minimum horizontal separation distance of CO monitor's inlet probe from its
supporting structure (meters):
a. 0.5
b. 1
c. 2
d. 5
21. Minimum vertical separation distance of CO monitor's inlet probe from its sup-
porting structure (meters):
a. 0.5
b. 1
c. 2
d. 5
22. Arc of unrestricted air flow for CO monitor inlet probes which are not located
on sides of buildings (degrees):
a. 90
b. 180
c. 270
d. 360
23. Arc of unrestricted air flow for CO monitor inlet probes which are located on
sides of buildings (degrees):
a. 45
b. 90
c. 135
d. 180
24. For middle scale and neighborhood scale sites, height range of CO monitor's
inlet probe above ground level (meters):
a. 2 to 10
b. 3 to 10
c. 2 to 15
d. 3 to 15
25. Separation distance range of a microscale CO monitor's inlet probe from the
edge of the nearest traffic lane (meters):
a. 1 to 5
b. 1 to 10
c. 2 to 5
d. 2 to 10
6-19
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26. Minimum separation distance of a microscale CO monitor's inlet probe from
the nearest traffic intersection (meters):
a. 1
b. 5
c. 10
d. 20
27. The probe inlet for a neighborhood scale CO SLAMS/NAMS monitor must be
located at least (*/ meters from a roadway having an average daily
traffic volume less than 10,000.
a. 5
b. 10
c. 15
d. 20
28. The minimum separation distance between the inlet probe of a neighborhood
scale CO SLAMS/NAMS monitor and a roadway having an average daily traf-
fic volume greater than 60,000 must be '•' meters.
a. 20
b. 50
c. 150
d. 250
For each of questions 29-34, select the O3/NO2 SLAMS/NAMS siting criterion
specified in Appendix E of 40 CFR 58 for the specified parameter.
29. Height range of O3/NO2 monitor's inlet probe above ground level (meters):
a. 2 to 10
b. 3 to 10
c. 2 to 15
d. 3 to 15
30. Minimum horizontal separation distance of O3/NO2 monitor's inlet probe from
its supporting structure (meters):
a. 0.5
b. 1
c. 2
d. 5
31. Minimum vertical separation distance of O3/NO2 monitor's inlet probe from its
supporting structure (meters):
a. 0.5
b. 1
c. 2
d. 5
32. O3/NO2 monitor inlet probe's minimum separation distance from trees (meters):
a. 2
b. 5
c. 10
d. 20
6-20
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33. Arc of unrestricted air flow for O3/NO2 monitor inlet probes which are not
located on sides of buildings (degrees):
a. 90
b. 180
c. 270
d. 360
34. Arc of unrestricted air flow for O3/NO2 monitor inlet probes which are located
on sides of buildings (degrees):
a. 45
b. 90
c. 135
d. 180
35. The probe inlet for a neighborhood/urban scale Os or NO2 SLAMS/NAMS
monitor must be located at least v) meters from a roadway having an
average daily traffic volume less than 10,000.
a. 5
b. 10
c. 15
d. 20
36. The minimum separation distance between the inlet probe of a
neighborhood/urban scale O3 or NO2 SLAMS/NAMS monitor and a road-
way having an average daily traffic volume greater than 110,000 must be
(•) meters.
a. 20
b. 50
c. 150
d. 250
37. True or False? Minimum roadway separation distances for neighborhood/
urban O3 and NO2 SLAMS/NAMS must also be maintained between
neighborhood/urban Os and NO2 SLAMS/NAMS and other similar volumes of
automotive traffic, such as parking lots.
38. True or False? Neighborhood/urban CO, OS( and NO2 SLAMS/NAMS that do
not meet the minimum roadway separation requirements should be classified as
middle scale.
39. Appendix E of 40 CFR 58 requires that the inlet probe of an O3 or NO2
monitor be located away from obstacles such as buildings, so that the distance
between an obstacle and the probe is at least v) times the height that
the obstacle protrudes above the probe.
a. 2
b. 4
c. 5
d. 10
6-21
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40. True or False? Appendix E of 40 CFR 58 requires that intake sampling lines
for existing and new O3 and NO2 SLAMS/NAMS monitors be constructed of
borosilicate glass, FEP teflon, or their equivalent.
41. Appendix E of 40 CFR 58 requires that sampling probes at O3 and NO2
SLAMS/NAMS have a sample residence time of less than (•/ seconds.
a. 5
b. 10
c. 15
d. 20
42. True or False? If the probe siting criteria specified in Appendix E of 40 CFR 58
cannot be met, a written request for a waiver must be submitted to EPA.
43. In establishing a new SLAMS/NAMS, which of the following conditions must
be met in order to obtain a waiver from the monitor siting criteria specified in
Appendix E of 40 CFR 58?
a. The site can be demonstrated to be as representative of the monitoring area
as it would be if the siting criteria were being met.
b. The monitor or probe cannot reasonably be located so as to meet the siting
criteria.
c. both a and b, above
d. either a or b, above
44. For an existing monitoring station, which of the following conditions must be
met in order to obtain a waiver from the monitor siting criteria specified in
Appendix E of 40 CFR 58?
a. The site can be demonstrated to be as representative of the monitoring area
as it would be if the siting criteria were being met.
b. The monitor or probe cannot reasonably be located so as to meet the siting
criteria.
c. both a and b, above
d. either a or b, above
45. For preconstruction PSD ambient air quality monitoring, monitors should be
sited at which of the following locations?
a. area(s) of the maximum air pollutant concentration increase expected from
the proposed source or modification
b. area(s) of the maximum air pollutant concentration resulting from existing
sources of emissions
c. area(s) where the maximum air pollutant concentration would hypo-
thetically occur based on the combined effect of existing sources and the
proposed new source or modification
d. all of the above
6-22
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46. For postconstruction PSD ambient air quality monitoring, monitors should be
sited at which of the following locations?
a. expected area of the maximum air pollutant concentration resulting from
the new source or modification
b. area(s) where the maximum pollutant concentration will occur based on the
combined effect of existing sources and the new source or modification
c. area(s) of the maximum air pollutant concentration resulting from existing
sources of emissions
d. all of the above
e. a and b, above
47. For preconstruction PSD ambient air quality monitoring in a multisource
setting, v1/ to ' ' monitoring sites will be sufficient for most
situations.
a. 1, 3
b. 1, 4
c. 2, 5
d. 2, 6
48. For postconstruction PSD ambient air quality monitoring in a multisource
setting, v) or (*/ monitoring sites will be sufficient for most
situations.
a. 1, 2
b. 2, 3
c. 3, 4
d. 4, 5
49. For preconstruction or postconstruction PSD ambient air quality monitoring in
a remote area, v/ or (•) monitoring sites will be sufficient
for most situations.
a. 1, 2
b. 2, 3
c. 3, 4
d. 4, 5
50. True or False? Ambient air is defined in 40 CFR 50 as "that portion of the
atmosphere, external to buildings, to which the general public has access".
51. True or False? PSD ambient air quality monitors should be placed in locations
which satisfy the definition of ambient air.
6-23
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52. For PSD purposes, when monitoring gaseous concentrations resulting from a
ground-level source, the monitor's inlet probe should be located as close as
possible to (•' meter(s) above ground level.
a. 1
b. 3
c. 10
d. 15
6-24
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Review Exercise Answers
Page(s) of Section 6
of Guidebook
1. e 4
2. False 4
3. d 4
4. b 4
5. c : 4
6. a 4
7. True 6
8. c 6-7
9. c 7
10. a 5,7
11. b 6-7
12. c 6-7
13. b 7
14. a 7
15. d 7
16. a 7
17. b 7
18. b 7
19. b 8
20. b 8
21. b 8
22. c 8
23. d 8
24. d 8
25. d 8
26. c 8
27. b 8
28. c 8
29. d 8-9
30. b 8-9
31. b 8-9
32. d 8-9
33. c 8-9
34. d 8-9
35. b 9
36. d 9
37. True 9
38. True 8-9
39. a 8-9
40. True 9
6-25
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Page(s) of Section 6
of Guidebook
41. d 9
42. True 8
43. c 9
44. d 9
45. d 13
46. e 14
47. b 13
48. b 14
49. a 13-14
50. True 14
51. True 14
52. b 15
6-26
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TECHNICAL REPORT DATA
(Please read laitructions on the reverse before completing/
REPORT NO.
EPA 450/2-82-002
2.
3. RECIPIENT'S ACCESSIOr*NO.
TITLE AND SUBTITLE
APTI Correspondence Course 437
Site Selection for the Monitoring of CO and
Photochemical Pollutants in Ambient Air: Guidebook
5. REPORT DATE
February 1982
6. PERFORMING ORGANIZATION CODE
. AUTHORIS)
8. PERFORMING ORGANIZATION REPORT NO.
B. M. Ray
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Northrop Services, Inc.
P.O. Box 12313
Research Triangle Park, NC 27709
10. PROGRAM ELEMENT NO.
B18A2C
11. CONTRACT/GRANT NO.
68-02-3573
12. SPONSORING AGENCY NAME AND ADDRESS
U. S. Environmental Protection Agency
Manpower and Technical Information Branch
Air Pollution Training Institute
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Student Guidebook
14. SPONSORING AGENCY CODE
EPA-OANR-OAQPS
15. SUPPLEMENTARY NOTES
Project Officer for this publication is R. E. Townsend, EPA-ERC, RTP, NC 27711
16. ABSTRACT
This Guidebook was developed for use in the Air Pollution Training Institute s
Correspondence Course 437, "Site Selection for the Monitoring of CO and
Photochemical Pollutants in Ambient Air." It contains reading assignments
and review exercises covering the following topics:
Use of Monitoring Data and Related Monitor-Siting Objectives
Special Considerations Associated with the Monitoring of CO, NMHC,
NO, NOo, and 03
Procedures and Criteria for Site Selection for CO, NMHC, NO, N02 and 03
Monitors
Rationale for CO, NMHC, NO, N02, and 03 Monitor-Siting Criteria
Network Design and Probe-Siting Criteria for CO, N02, and 03 SLAMS,
NAMS, and PSD Monitoring Stations
The Guidebook is designed for use in conjunction with "Selecting Sites for
Carbon Monoxide Monitoring" (EPA 450/3-75-077) and "Site Selection for the
Monitoring of Photochemical Air Pollutants" (EPA 450/3-78-013).
17.
KEY WORDS AND DOCUMENT ANALYSIS
a.
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COS AT I Field/Group
Training
Air Pollution
Measurement
Ambient Air Monitoring
Monitor Siting
Training Course
13B
51
68A
1S. DISTRIBUTION STATEMENT
Unlimited, available
from the National Technical Information
Service, 5285 Port Royal Rd.,
Springfield. VA 22161
19. SECURITY CLASS (ThisReport!
unclassified
21. NO. OF PAGES
77
20. SECURITY CLASS (This page)
unclassified
22. PRICE
EPA Form 2220-1 (t-73)
6-27
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