&EPA
United States
Environmental Protection
Agency
Air Pollution Training intoftute
MD20
Environmental Reeeareh Center
Keeeerch Triangle Park, NC 27711
EPA 460/2-81-061
December, 1961
Air
APTI
Correspondence Course 436
Site Selection
for the Monitoring of SO2
and TSP in Ambient Air
Guidebook
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United States
Environmental Protection
Agency
Air Pollution Training Institute
MD20
Environmental Research Center
Research Triangle Park, NC Z7711
EPA 460/2-81 -061
December, 1961
Air
APT!
Correspondence Course 436
Site Selection
for the Monitoring of SO2
and TSP in the 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 Planning and 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.
u
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Table of Contents
Page
Course Introduction 0-1
Section 1. Introduction to SOt Monitoring 1-1
Review Exercise 1-5
Review Exercise Answers 1-5
Section 2. Site Selection for General-Level SOt Monitoring Stations 2-1
Review Exercise 2-5
Review Exercise Answers 2-10
Section 3. Locating Proximate Middle Scale SO» Monitoring
Stations for Urban and Isolated Point Sources 3-1
Review Exercise S-S
Review Exercise Answers 3-10
Section 4. Rationale for SO* Monitor Siting Criteria 4-1
Review Exercise 4-3
Review Exercise Answers 4-7
Section 5. Introduction to TSP Monitoring and Site Selection
for Regional and Neighborhood TSP Monitoring Stations 5-1
Review Exercise 5-3
Review Exercise Answers 5-7
Section 6. Locating Middle Scale TSP Monitoring Stations
and Rationale for TSP Siting Criteria 6-1
Review Exercise 6-3
Review Exercise Answers 6-10
Section 7. Monitoring Network Design and Probe Siting Criteria for TSP
and SO, SLAMS, NAMS, and PSD Monitoring Stations 7-1
Excerpts of 40 CFR 58 Appendices D and E 7-4
Excerpts of "Ambient Monitoring Guidelines for Prevention of
Significant Deterioration (PSD)" 7-12
Review Exercise 7-16
Review Exercise Answers 7-24
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 SO, and TSP monitors. The course presents general concepts of ambient
monitor site selection and specific, detailed considerations and procedures for selec-
ting SO, and TSP ambient monitoring sites. Course topics include the following:
• use of monitoring data and related monitor siting objectives
• special considerations associated with SO, and TSP monitoring
• procedures and criteria for site selection for SO, and TSP monitors
• rationale for SO, and TSP siting criteria
• network design and probe siting criteria for SO, and TSP 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 SO, and TSP ambient monitor sites.
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 SO, and TSP
monitors for a given monitoring objective.
8. describe the logic of the SO, and TSP siting criteria.
0-1
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Sequence, Lesson Titles, and Trainee Involvement Time
Trainee involvement
Lesson number Lesson title time (hours)
1 Introduction to SO, Monitoring 4
2 Site Selection for General Level 6
SO, Monitoring Stations
5 Locating Proximate Middle Scale 7
SOS Monitoring Stations for Urban
and Isolated Point Sources
4 Rationale for SO, Monitor Siting 6
Criteria
5 Introduction to TSP Monitoring 4
and Site Selection for Regional
and Neighborhood TSP Moni-
toring Stations
6 Locating Middle Scale TSP 4
Monitoring Stations and Rationale
for TSP Siting Criteria
7 Monitoring Network Design and 4
Probe Siting Criteria for TSP and
SO, SLAMS, NAMS, and PSD
Monitoring Stations
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 4S6 Site Selection for the Monitoring of
and TSP in Ambient Air: Guidebook"
• EPA-450/3-77-013 "Optimum Site Exposure Criteria for SOt Monitoring"
• EPA-450/S-77-018 "Selecting Sites for Monitoring Total Suspended
Particulates"
• protractor
• ruler
• pencil or pen
Use of this Guidebook
Relationship Between Guidebook and Assigned Reading Materials
This guidebook directs your progress through the reference texts "Optimum Site
Exposure Criteria for SO» Monitoring" and "Selecting Sites for Monitoring Total
Suspended Particulates" 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 seven reading assignment sections which correspond to the
seven 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.
0-5
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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 SO2 Monitoring
Reading Assignment
Pages 1-26 of EPA-450/S-77-01S "Optimum Site Exposure Criteria for SO,
Monitoring".
Reading Assignment Topics
General emission characteristics of SO, sources
Characteristics of anthropogenic sources of SO,
Need for objective, uniform siting procedures
Uses of SOX monitoring data
Monitor siting objectives
Spatial scales of representativeness
General types of monitoring sites
Correlation of general types of monitoring sites with siting objectives
Learning Goal and Objectives
Learning Goal
To farr.iliarize you with the major sources of SO, emissions and the general types of
monitoring sites used to measure ambient SOS concentrations.
Learning Objectives
At the end of this section, you should be able to:
1. describe contributions and effects of natural and anthropogenic sources of
SO,.
2. identify typical concentration patterns of SO, emissions from anthropogenic
sources.
3. associate major anthropogenic SO, source categories with geographical areas
of the United States.
4. describe contributions of urban and rural sources of SO, emissions.
5. differentiate between point and area sources of SO, emissions.
6. define spatial scale of representativeness.
7. associate typical spatial scales of representativeness with physical dimensions
of siting areas.
1-1
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8. associate typical spatial scales of representativeness with general land-use
areas.
9. differentiate between proximate and general-level monitoring sites.
10. associate general types of monitoring sites with siting objectives.
Reading Guidance
• In addition to the regulatory concerns pertaining to ambient air monitoring
that are described on page seven of the assigned reading material, the United
States Environmental Protection Agency has also promulgated regulations
specifying monitoring network design and monitor probe siting requirements
for State Implementation Plan purposes. These regulations are found in Title
40, Part 58 of the Code of Federal Regulations (40 CFR 58) and are addressed
in Section 7 of this guidebook.
• Refer often to Tables S-l and 3-2 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 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. Globally, about v) percent of all SOj in the atmosphere comes from
natural sources.
a. 75
b. 25
c. 50
d. 10
2. True or False? Intense concentrations of ambient SO, are usually found near
anthropogenic SO, emission sources.
Match the geographical areas of the United States with their major anthropogenic
SOi source categories. (Questions 3-5)
S. North a. transportation/power plants/industrial processes
4. South b. industrial processes/transportation
5. West c. commercial and residential heating/power plants
6. About (•) percent of SOt emissions occur in urban areas.
a. 65
b. 50
c. 25
d. 90
7. Which of the following is an area source of SO» emissions?
a. power plant
b. smelter
c. highway
d. none of the above
Match the following spatial scales of representativeness with their corresponding
dimensions. (Questions 8-12)
8. microscale a. 0.1 to 0.5 kilometer
9. middle scale b. greater than 50 kilometers
10. neighborhood scale c. less than 0.1 kilometer
11. urban scale d. 4 to 50 kilometers
12. regional scale e. 0.5 to 4 kilometers
1-S
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Match the following land use areas with the spatial scale of representativeness most
likely to be represented by a single SO» measurement in each of them. (Questions IS-15)
13. urban a. middle scale
14. suburban b. neighborhood scale
15. rural c. regional scale
16. True or False? Proximate sites are those associated with siting objectives that
require information regarding impacts from a specific source or a group of
specific sources.
17. True or False? General-level sites are those located in areas where information
concerning the total air pollutant concentration is important but where infor-
mation concerning contributions from individual sources to the total concen-
tration is relatively unimportant.
Match the following SO, monitor siting objectives with their appropriate types of
monitoring sites. (Questions 18-21)
18. determination of the peak a. general-level regional scale
concentration in an
urban area
19. determination of the b. proximate micro/middle scale
impact of an isolated
point source
20. determination of the base c. general-level middle scale
concentration in areas
of projected growth
21. assessment of background d. general-level neighborhood scale
concentrations in rural areas
1-4
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Review Exercise Answers
Page of SO,
Siting Manual
1. c 1
2. True 1
S. c 4
4. a 4
5. b 4
6. a 4
7. c 5
8. c 17
9. a 17
10. e 17
11. d 18
12. b 18
IS. a 19
14. b 19
15. c 19
16. True 21
17. True 21
18. c 24
19. b 24
20. d 24
21. a : 24
1-5
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Section 2
Site Selection for General-Level SO2
Monitoring Stations
Reading Assignment
Pages 27-52 of EPA-450/S-77-013 "Optimum Site Exposure Criteria for SO,
Monitoring".
Reading Assignment Topics
• Site selection aids and background material
• Locating general-level regional scale SOt monitoring stations
• Locating general-level neighborhood scale SO, monitoring stations
• Locating general-level middle scale SO, monitoring stations
Learning Goal and Objectives
Learning Goal
To familiarize you with the siting of regional, neighborhood, and general-level
middle scale SO, monitoring stations.
Learning Objectives
At the end of this section, you should be able to:
1. recognize the appropriate SO, concentration gradient for regional scale SO,
monitoring sites.
2. determine the number of SO, monitoring sites required to represent SO, con-
centrations over an area.
S. select the general siting area for regional mean SO, monitoring stations.
4. select the general siting area for SO, transport monitoring stations.
5. select the general siting area for SO, emergency monitoring stations.
6. select the general siting area for population exposure and projected growth
neighborhood scale SO, monitoring stations.
7. select the general siting area for peak concentration general-level middle scale
SO, monitoring stations.
2-1
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Reading Guidance
• Because "Optimum Site Exposure Criteria for SO, Monitoring" was published
before the promulgation of 40 CFR 58, the monitor probe heights specified in
the document do not agree with the required probe heights of 40 CFR 58.
Probe heights specified in 40 CFR 58 are addressed in Section 7 of this
guidebook.
• Wind roses are discussed in this reading assignment. A wind rose is a graphical
representation of wind directional frequency. The farther that the bar extends
from the circle, the more frequently the wind blows from that direction.
• In this reading assignment, the winter wind rose is recommended for use in
selecting SOS monitoring sites. The basis for this recommendation is that for
many areas, especially northern areas of the United States, winter is the season
associated with maximum emissions of SOS because of space heating. However,
you should determine the season associated with maximum SO, emissions for
your specific monitor siting situation.
• Refer often to the flow charts 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 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 measurements from a single SOS monitoring site will represent concentra-
tions over the regional spatial scale if the concentration gradient over the area
of interest does not exceed about v) Mg/m* PC* kilometer.
a. 0.5
b. 0.1
c. 1.0
d. S.O
2. If the SOj concentration extremes over the area of interest are not within
about (^) percent of the average value, then more than one SO»
monitoring site will be needed to represent SO, concentrations over the area.
a. 5
b. 10
c. 25
d. 50
2-5
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S. Which of the four general siting areas, labeled a through d, is the best siting
area for an SOi regional mean concentration monitoring station?
Power plant
area
Town
(population: 50,000)
Industrial
source
Wind rose
Homes
10 20 SO 40 50
Kilometer*
2-4
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4. Which of the four general siting areas, labeled a through d, is the best siting
area for measuring the maximum in-state SO» concentration resulting from
the out-of-state urban center?
In-ttate
urban center
Out-of-uate
urban center
Wind
l
_L
I
0 10 20 SO 40 50
Kilometers
5. Which of the four general siting areas, labeled a through d in question four, is
the best siting area for measuring the most frequent in-state SOS concentra-
tions resulting from the out-of-state urban center?
2-5
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6. Which of the four general siting areas, labeled a through d, is the best siting
area for assessing the transport of SO! from the distant city into the urban
center?
Distant city
Wind
Urban center
(population: 200,000)
0 10 20 SO 40 50
Kilometers
2-6
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7. The figure below represents a city area with relative sulfur dioxide emission
rates plotted. Which of the five general siting areas, labeled a through e, are
the best two sites for SQi emergency episode monitoring?
2-7
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8. Which of the four general siting areas, labeled a through d, is the best siting
area for an urban population exposure/projected growth neighborhood scale
SOj monitoring station?
Direction toward
the nearest
urban center
Wind direction
associated with
frequency
of impacts
from nearby
sources
o
o
Tentative riting
area for
neighborhood SO,
monitoring station
G
500
Meters
1.000
0 • SOt point source
2-8
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9. Which of the four general siting areas, labeled a through d, is the best siting
area for a general-level middle scale monitoring station for determining peak
SOj concentrations?
Middle icale
area of interest
Wind direction
associated with
maximum frequency
of impacts from
nearby sources
I
I
J
100 200 SOO 400 500
Meters
0 • SOt point source
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Review Exercise Answers
Page(s) of SO,
Siting Manual
1. a 29
2. c 29
3. d SI
4. a 51
5. b 31
6. c 31
7. aandb 38
8. d 41-44
9. b 48-50
2-10
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Section 3
Locating Proximate Middle Scale SO2
Monitoring Stations for Urban and
Isolated Point Sources
Reading Assignment
Pages 52-82 of EPA-450/S-77-01S "Optimum Site Exposure Criteria for SO,
Monitoring".
Reading Assignment Topics
• Locating proximate middle scale SO, monitoring stations for urban point
sources
• Locating proximate middle scale SOZ monitoring stations for isolated point
sources
Learning Goal and Objectives
/
Learning Goal
To familiarize you with the siting of proximate middle scale SOt monitoring sta-
tions for urban and isolated point sources.
Learning Objectives
At the end of this section, you should be able to:
1. select the general siting area for an SO, monitoring station for assessing the
annual SOt impact from an urban point source.
2. recognize source characteristics which increase the probability of stack
down wash.
3. define flat terrain.
4. select the general siting areas for an isolated point source's peak SO, concen-
tration and for background stations in a flat terrain setting.
5. recognize the usefulness of mobile sampling for determining monitoring site
locations.
6. define sea-breeze fumigation and recognize its cause.
7. recognize necessary information for determining a sea-breeze fumigation
area.
S-l
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8. describe the effect of terrain elevation on vertical mixing depth for a
sea-breeze situation.
9. select the general siting areas for an isolated point source's peak SOS concen-
tration and for background stations in a ridge/valley setting under various
meteorological conditions.
10. describe the effects of moderately rough terrain on ambient SOS concentra-
tions resulting from isolated point sources.
11. recognize general siting considerations for locating SOS monitoring stations
for isolated point sources in extremely rough terrain.
Reading Guidance
• Refer often to the flow chart 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 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 the fol-
lowing questions. These will help you determine whether or not you are mastering
the material.
1. Yvliich of the four general siting areas, labeled a through d, is the best siting
area for a proximate middle scale monitoring station for determining the
maximum annual SOX impact from the urban point source?
Direction toward
the urban point source
Windrow
Middle scale
area of interest
_L
j
100 200 300 400 500
Meters
point source
3-S
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2. Stack downwash conditions may occur if the ratio between the stack gas
velocity and the wind velocity is less than about (?)
a. 15
b. 10
c. 5
d. 1.5
3. True or False? Stack downwash is likely to occur if the heights of any buildings
and other obstructions that exist within a distance of 10 stack heights of the
source exceed 2/5 of the height of the stack.
4. Terrain is deemed to be flat if terrain elevations greater than 2/5 the height of
the stack do not exist within (?) kilometers of the source.
a. 10
b. 50
c. 25
d. 100
5. Which of the four general siting areas, labeled a through d, is the best siting
area for a monitoring station for determining peak SOZ concentrations
resulting from the isolated point source?
Wind
Isolated point lource
3-4
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6. Which of the four general siting areas, labeled a through d in question 5, is
the best siting area for an SOS background monitoring station?
7. True or False? Mobile sampling should be used in locating peak SO» concen-
tration monitoring stations for determining the air quality impacts of isolated
point sources.
8. The following figure depicts:
a. plume lofting.
b. plume fanning.
c. sea-breeze fumigation.
d. none of the above
9. Which of the following is necessary for determining a sea-breeze fumigation
area?
a. the difference between the atmospheric temperature at plume height and
the sea-surface temperature
b. the mean wind speed of the marine air/plume layer
c. the height of the plume
d. all of the above
10. In a sea-breeze situation, vertical mixing depth vJ as the terrain
slopes upward from flat.
a. decreases
b. increases
c. remains the same
11. In a sea-breeze situation, vertical mixing depth (?) as the terrain
slopes downward from flat.
a. remains the same
b. increases
c. decreases
5-5
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Which of the four general siting areas, labeled a through d, is the best siting area
for a proximate middle scale monitoring station for determining peak SO» con-
centrations resulting from the point source for each of the following ridge/valley
situations? (Questions 12-15)
Stable
atmospheric
conditions
NN\VSVW\\\\\\\NVv
Wind direction ^
Light to
moderate wind
3-6
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15.
Neutral or unstable
atmospheric conditions,
moderate to strong
3-7
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16. Which of the four general siting areas, labeled a through d, is the best siting
area for a background SOS monitoring station?
17. True or False? When monitoring SOj resulting from an isolated point source in
a ridge/valley setting, one monitoring site should be established at a point
nearest the source on the valley wall that is most frequently downwind of the
source.
18. True or False? The major effect of moderately rough terrain on a plume is to
decrease its rate of dispersal.
19. True or False? In a moderately rough terrain setting, SOt concentrations are
always greater at the'top of obstacles.
5-8
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20. Monitoring stations should be established at which of the following locations
when monitoring SOS impacts from an isolated point source that is located in
extremely rough terrain?
a. for regions subject to periods of low mixing depths, in basins having inlets
for the point source's plume
b. at ridge top locations in the general downwind directions from the point
source
c. both a and b, above
d. none of the above
5-9
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Review Exercise Answers
Page(s) of SO,
Siting Manual
1. d 54-56
2. d 61
3. True 61
4. a 60
5. b 62
6. d 62
7. True 63
B. c 64
9. d 65-66
10. b 66
11. a 66
12. a 71-72
13. d 72-73
14. a 72-73
15. b 74-75
16. a 74
17. True 74
18. False 77
19. False 77
20. c 80,82
S-10
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Section 4
Rationale for SO2 Monitor
Siting Criteria
Reading Assignment
Pages 8S-102 of EPA-450/S-77-01S "Optimum Site Exposure Criteria for SO,
Monitoring".
Reading Assignment Topics
• Undue influence effects of nearby SO, sources
• Meteorological processes pertinent to monitor siting
• Effect of ambient temperature on SO, emission rates
• Chemical and physical interactions of SO, pertinent to monitor siting
Learning Goal and Objectives
Learning Goal
To familiarize you with the logic of the SO, monitor siting criteria.
Learning Objectives
At the end of this section, you should be able to:
1. associate assumed undue influence SO, concentration levels with the effects
of SO, sources in rural, urban, and suburban areas.
2. describe assumptions for determining interference distances.
5. differentiate between the relative influences of a nearby SO, source on SO,
monitoring stations within and outside the source's 10° plume sector.
4. recognize topographic effects on the shape of an air parcel and on wind
speed.
5. define mechanical turbulence.
6. recognize the averaging effect of an air cavity on pollutant concentration.
7. describe the causes of upslope and downslope air flows.
8. recognize the effects of obstacles on air flows under stable and unstable
atmospheric conditions.
9. recognize the effect of ambient temperature on SO, emission rates.
10. associate assumed SO, half-lives with areas having populations greater than
and less than one million.
4-1
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Reading Guidance
• Refer often to the figures of the assigned reading material as you progress
through the assignment.
• 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 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.
Select the values that were assumed for each of the following parameters in
determining the regional scale interference distance for a major urban area.
(Questions 1-5)
1. Wind speed (m/s):
a. 0.1
b. 1
c. 10
d. 15
2. Half-life of SO, (hours):
a. 6
b. 12
c. 24
d. S
S. Averaging interval of monitoring site SOt concentrations (hours):
a. 1
b. 3
c. 24
t
d. none of the above
4. SO, emission rate for a major urban area (g/s/ml):
a. 0.75X10'6
b. 0.63x10-*
c. 0.86x10'*
d. 0.72xlO's
5. Undue influence SO, concentration level (/ig/ms):
a. 0.1
b. 2.6
c. 25
d. 50
Select the values that were assumed for each of the following parameters in deter-
mining the point source, minor source, and source interference distances (PSID,
MSID, and SID, respectively). (Questions 6-10)
6. Effective SO, emission height (m):
a. zero
b. 10
c. 15
d. 25
4-3
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7. Undue influence SOt concentration level (jig/m8):
a. 1
b. 10
c. 100
d. 500
8. Wind speed (m/s):
a. 0.1
b. 1
c. 10
d. 15
9. Atmospheric stability class:
a. A
b. B
c. C
d. D
10. Averaging interval of monitoring site SOt concentrations (hours):
a. 0.5
b. 1
c. 3
d. 24
11. An SO» source has (?) influence on SO» concentrations measured at
monitoring sites within its 10 degree plume sector than at sites outside its 10
degree plume sector.
a. more
b. less
c. the same
12. As an air parcel passes between two obstructions, the parcel is squeezed
(?) and its speed (?)
a. vertically, increases
b. vertically, decreases
c. horizontally, increases
d. horizontally, decreases
IS. As an air parcel passes over a mountain, the parcel is squeezed (?)
and its speed (?)
a. vertically, increases
b. vertically, decreases
c. horizontally, increases
d. horizontally, decreases
14. As an air parcel passes across a valley, the parcel expands (?) and its
speed _!!!_.
a. vertically, increases
b. vertically, decreases
c. horizontally, increases
d. horizontally, decreases
4-4
-------
15. True or False? Mechanical turbulence is produced when air moves over a
rough surface.
16. Which of the locations, labeled a through d, would be the most likely site of
an air cavity wake?
Wind direction
17. An air cavity tends to
a. average
b. increase
c. decrease
(ZL
pollutant concentrations.
18. True or False? When the general wind direction is oblique to a ridge-valley
axis, channeling of the wind often occurs.
19. Mountain passes (?) wind speeds.
, a. increase
b. decrease
c. have no effect on
20. At night, (?)
air flows are caused by
of the air adjacent to
the ground along a valley floor and slope.
a. downslope, heating
b. downslope, cooling
c. upslope, heating
d. upslope, cooling
21. In the daytime, (?) air flows are caused by
adjacent to the ground along a valley floor and slope.
a. downslope, heating
b. downslope, cooling
c. upslope, heating
d. upslope, cooling
of the air
45
-------
22. Under v) atmospheric conditions, air parcels tend to move
(?) obstacles.
a. unstable, around
b. stable, over
c. unstable, over
d. none of the above
23. Under (?) atmospheric conditions, air parcels tend to move
(?) obstacles.
a. stable, around
b. unstable, around
c. stable, over
d. none of the above
24. True or False? The urban heat-island effect causes air to flow into urban
centers at night.
25. True or False? The pollutant averaging effects of building wakes and air cavity
flows cause the SOS concentration distribution of a city to be uniform up to at
least the mean building height.
26. True or False? Ambient temperature may influence the rate of SOt emissions.
27. The SOj monitoring criteria are based on an assumed SOS half-life of
(?) hour(s) for cities with populations greater than one million, and
(?) hour(s) for cities with populations of one million or less.
a. 1. 10
b. 10, 1
c. 1, S
d. S, 10
4-6
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Review Exercise Answers
Page(s) of SO,
Siting Manual
1. b 84
2. d 84
3. b 84
4. c 84
5. b 84
6. a 85
7. b 85
8. b 85
9. d 85
10. c 85
11. a 87
12. c '. 88
IS. a 88
14. b 88
15. True 89
16. d 89
17. a 89
18. True 90
19. a 90
20. b , 90
21. c 90
22. c 91
23. a '. 91
24. True 92
25. True 95-96
26. True 99
27. c 102
4-7
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Section 5
Introduction to TSP Monitoring and
Site Selection for Regional and
Neighborhood TSP Monitoring Stations
Reading Assignment
Pages 1-49 of EPA-450/S-77-018 "Selecting Sites for Monitoring Total Suspended
Particulates".
Reading Assignment Topics
Need for careful selection of TSP monitoring sites
General siting approach for TSP samplers
Special characteristics of paniculate matter
Sources of paniculate matter
Classification of TSP monitoring sites
Locating regional scale TSP monitoring stations
Locating neighborhood scale TSP monitoring stations
Learning Goal and Objectives
Learning Goal
To familiarize you with general considerations for monitoring TSP matter and
specific information for siting regional and neighborhood TSP monitoring stations.
Learning Objectives
At the end of this section, you should be able to:
1. explain the need for considering panicle size in the selection of TSP
monitoring sites.
2. describe the transport and removal mechanisms for large and small panicles.
3. differentiate between the health and visibility effects of large and small
panicles.
4. describe contributions and impacts of natural and anthropogenic sources of
TSP matter emissions.
5. define "paniculate emissions from ground-level sources".
6. recognize the applicability of middle scale TSP monitoring sites for strip
development, freeway corridors, and downtown street canyons.
5-1
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7. differentiate between the location of the maximum annual TSP impact area
and the location of the maximum 24-hour TSP impact area for a large,
elevated TSP point source.
8. recognize the importance of monitoring TSP matter in high TSP concentra-
tion/high population areas for determining compliance with the TSP
National Ambient Air Quality Standards.
9. select the general siting area for regional mean TSP monitoring stations.
10. select the general siting area for TSP transport monitoring stations.
11. select the general siting area for determining average neighborhood TSP
concentrations.
12. select the general siting area for determining highest average neighborhood
TSP concentrations.
Reading Guidance
• Because "Selecting Sites for Monitoring Total Suspended Particulates" was
published before the promulgation of 40 CFR 58, the TSP sampler roadway
set-back distances specified in the document do not agree with the required
set-back distances of 40 CFR 58. Set-back distances specified in 40 CFR 58 are
addressed in Section 7 of this guidebook.
• Natural dusts mentioned on page 10 of the reading assignment include an
indeterminate amount of paniculate emissions from anthropogenic sources.
• The titles for Figures 11 and 15 of the assigned reading material are reversed.
• Refer often to the flow charts 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 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 is(are) an important reason(s) for considering panicle
size in the selection of TSP monitoring sites?
a. Mass concentration varies with panicle size.
b. Panicle removal processes depend on panicle size.
c. Health effects are influenced by panicle size.
d. all of the above
2. True or False? Small panicles are likely to stay airborne longer and be
transported fanher than large panicles.
5. True or False? Large panicles are more subject to removal by impaction on
obstacles to air flow than small panicles.
4. True or False? Deposition in the lungs is a greater health hazard with large
panicles than with small panicles.
5. True or False? The most important visibility-reducing panicles are those below
10 jim in size.
6. In the United States, natural dusts constitute nearly (*) percent of the
paniculate emissions.
a. 10
b. 25
c. 50
d. 90
7. True or False? In general, high atmospheric concentrations of large panicles
are limited to areas near their sources.
8. In the United States, about (•' percent of the anthropogenic par-
ticulate emissions originate from stationary fuel combustion and industrial
processes.
a. 15
b. 25
c. 50
d. 85
9. Panicles which are blown at least (?) meter(s) from a ground-level
source are considered paniculate emissions of the source.
a. 1
b. 6
c. 14
d. 30
5-3
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10. True or False? The middle spatial scale of representativeness may be
appropriate when monitoring for TSP in strip developments, freeway corridors,
or downtown street canyons.
11. True or False? In general, one TSP sampler is sufficient for determining the
maximum annual and maximum 24-hour TSP impacts from a large, elevated
source.
12. The most important locations for monitoring to determine compliance with
the TSP National Ambient Air Quality Standards are in areas which have
a. high TSP concentrations.
b. large populations.
c. high TSP concentrations and large populations.
d. none of the above
13. Which of the four general siting areas, labeled a through d, is the best siting
area for a TSP regional mean concentration monitoring station?
Windrow
Major highway Urban area
0 5 10
Kilometers
5-4
-------
14. Which of the four general siting areas, labeled a through d, is the best siting
area for locating a second regional monitoring station for assessing the
transport of TSP into the urban area?
Wind rote
TSP transport ] D
monitoring station
Urban area
5-5
-------
15. The figure below represents an urban area with relative TSP concentrations
plotted. Which of the four general siting areas, labeled a through d, is the best
siting area for assessing TSP concentrations in neighborhoods which have
average TSP concentrations in the urban area?
16. Which of the four general siting areas, labeled a through d in question 15, is
the best siting area for assessing TSP concentrations in neighborhoods which
have the highest TSP concentrations in the urban area?
5-6
-------
Review Exercise Answers
Page(s) of TSP
Siting Manual
1. d 2
2. True 5
3. True 5
4. False 7
5. True 7
6. c 10
7. True 10
8. d 11
9. b 12
10. True 15
11. False 18-19
12. c 23
13. d 30,33,36
14. c 33,37
15. c 39,45
16. a 39,45
5-7
-------
Section 6
Locating Middle Scale TSP Monitoring
Stations and Rationale for TSP
Siting Criteria
Reading Assignment
Pages 50-74 of EPA-450/3-77-018 "Selecting Sites for Monitoring Total Suspended
Particulates".
Reading Assignment Topics
• Locating TSP monitoring stations for determining TSP impacts of elevated
point sources
• Locating TSP monitoring stations in street canyons and near traffic corridors
• Roadway effects peninent to TSP monitor siting
• Undue influence effects of urban areas on regional TSP monitoring
• Effects of obstructions pertinent to TSP monitor siting
, • Undue influence effects of nearby TSP sources
Learning Goal and Objectives
Learning Goal
To familiarize you with the siting of middle scale TSP monitoring stations and the
logic of the TSP siting criteria.
Learning Objectives
At the end of this section, you should be able to:
1. select general TSP monitor siting areas for determining the maximum annual
and most frequent high short-term TSP impacts of an elevated point source.
2. select TSP monitor sites in street canyons and near roadways for determining
worst-case and typical TSP concentrations.
5. describe the effects of horizontal and vertical placement of TSP samplers on
obtaining a representative TSP concentration near a roadway.
4. describe the assumptions for determining the urban area interference distance
for regional TSP monitoring sites.
5. recognize the effects of buildings on air flows.
6. describe the effects of nearby TSP area sources on TSP measurements.
6-1
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Reading Guidance
• Refer often to the flow charts concerning the selection of source-oriented
and middle scale TSP monitor sites as you progress through the assignment.
• 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 6. 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 7
of this guidebook.
6-2
-------
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. In general, areas of highest
average TSP concentrations resulting
from an elevated point source are more likely to occur nearer the point source
than are areas of highest v) average TSP concentrations resulting
from the point source.
a. long-term, short-term
b. short-term, long-term
c. none of the above
2. True or False? When monitoring air quality impacts from an elevated TSP
point source in an area which is influenced by additional sources of TSP, a
TSP sampling station should be located in the direction that is least frequently
downwind of the elevated point source.
5. The figure below represents a downtown street canyon area with average daily
traffic volumes for major streets indicated. Which of the four general siting
areas, labeled a through d, is the best siting area for locating a TSP sampler to
monitor the highest concentrations in the downtown area?
Wind rote for
•trong winds
6-3
-------
4. 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 TSP sampler to monitor typical
concentrations in the downtown area?
6-4
-------
5. 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 TSP sampler to monitor typical
concentrations in the downtown area?
6-5
-------
6. Which of the four general siting areas, labeled a through d, is the best siting
area for locating a TSP sampler to monitor maximum concentrations in the
street canyon?
Wind direction
7. 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 TSP sampler to monitor the highest concentra-
tions in the roadway area?
J
~l
5,000
10,000
I
Wind rote
r
6-6
-------
8. 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 TSP sampler to monitor typical concentrations in
the roadway area?
L
10,000
tf)
5,000
r
Wind
9. 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 TSP sampler to monitor typical concentrations in
the roadway area?
L
10,000
~i
5,000
r
Wind
6-7
-------
10. In proximity to a roadway, vertical TSP gradients resulting from the roadway
y) as the horizontal distance from the roadway (?)
a. increase, decreases
b. decrease, increases
c. remain the same, decreases
d. remain the same, increases
11. True or False? A regional TSP sampler should be sited so that it is not
influenced by paniculate matter resulting from unpaved roads.
Select the values that were assumed for each of the following parameters in deter-
mining the urban area interference distance for regional TSP monitoring sites.
(Questions 12-15)
12. Undue influence TSP concentration level (fig/ms):
a. 0.6
b. 6
c. 26
d. 50
13. Urban area TSP emission rate (/ig/mVs):
a. 1
b. 4
c. 12
d. 25
14. Daily average minimum wind speed (m/s):
a. 0.1
b. 0.5
c. 2
d. 5
15. TSP concentration averaging interval at monitoring site (hours):
a. S
b. 12
c. 24
d. 48
16. An air cavity extends downwind of a building about v) heights of the
building.
a. 1.5
b. 4.5
c. 9
d. 15
6-8
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17. A TSP sampler should be located at least (?) meters) above a 2-meter
high building in order for it to be reasonably well removed from the worst of
the air turbulence caused by the building.
a. 0.5
b. 1.5
c. 5.0
d. 7.5
18. Emissions from ground-level area sources located within two kilometers of a
TSP sampler account for more than half the TSP concentrations measured by
the sampler about (?) percent of the time.
a. 10 to 20
b. SO to 40
c. 60 to 70
d. 80 to 90
6-9
-------
Review Exercise Answers
Page(») of TSP
Siting Manual
1. b 50
2. True 53
3. a 56-57
4. a 56,58
5. d 58
6. d 57
7. d 59-60
8. b 59-60
9. a 59-60
10. b 66
11. False 67
12. b 68
13. b 68
14. c 68
15. c 68
16. a 70
17. b 70
18. b 73
6-10
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Section 7
Monitoring Network Design and Probe
Siting Criteria for TSP and SO2
SLAMS, NAMS, and PSD Monitoring
Stations
Reading Assignment
Pages 7-4 through 7-15 of this guidebook.
Reading Assignment Topics
• Excerpts of 40 CFR 58 Appendix D
• SLAMS network design for TSP and SO, monitoring stations
• NAMS network design for TSP and SO, monitoring stations
• Excerpts of 40 CFR 58 Appendix E
• Probe siting criteria for TSP SLAMS and NAMS
• Probe siting criteria for SO, SLAMS and NAMS
• Materials of construction and maximum sample residence time for SO,
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 TSP and SO, SLAMS, NAMS, and PSD
monitoring stations.
7-1
-------
Learning Objectives
At the end of 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.
S. recognize the primary monitoring objective of NAMS.
4. describe the two basic categories of NAMS.
5. recognize the two primary uses of NAMS data.
6. estimate the number of TSP and SO* NAMS required for a given
monitoring area.
7. recognize the spatial scale of representativeness required for TSP and SOj
NAMS.
8. select probe locations for TSP and SOt SLAMS, NAMS, and PSD
monitoring stations.
9. select the appropriate materials of construction and the sample residence
times for SOt probes.
10. describe waiver provisions for SLAMS and NAMS probe-siting criteria.
11. select general siting areas for PSD monitoring stations.
12. estimate the number of TSP and SOS monitoring stations needed for
preconstruction and postconstruction PSD monitoring networks.
13. define ambient air.
14. recognize that PSD monitors should be located in ambient air areas.
15. select appropriate probe heights for TSP and SOS 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 TSP and SO« PSD monitoring stations are iden-
tical to the probe-siting criteria for TSP and SOS 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.
• TSP sampler set-back distances described in the assigned reading materials
apply only to paved roadways.
7-2
-------
• 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".
• 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 7. It begins on page 7-16.
• 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.
7-5
-------
Excerpts of 40 CFR 58 Appendices D and £
I—Environmental Protection Agoncy
THI« 40—Protection of Environment
App.0
D—NETWORK DESIGN POD STATE
jure LOCAL Am MONITORING STATIONS
(SLAMS) AND NATIONAL AIK MONITORING
STATIONS (NAMS)
1. SLAMS Monitoring Objectives and Spa-
tial Scales
2. SLAMS Network Design Procedures
3.1 Background Information for Estab-
lishing SLAMS
2.2 Total Suspended Particulates (TSP)
OesigD Criteria for SLAMS
13 Sulfur Dioxide (SO,) Design Criteria
for SLAMS
2.4 Carbon Monoxide (CO) Design Crite-
ria (or 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 ) Design Criteria for NAMS
3.5 Nitrogen Dioxide (NO,) Design Crite-
ria (or NAMS
4. Summary
S. 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
(or 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
leneral 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 stating 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 pan.
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 of 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:
• Microtcale—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.
city-wide conditions with dimensions on the
order of 4 to 50 kilometers. This scale would
usually require more than one site for defi-
nition.
• Regional Scott—defines usually a rural
area of reasonably homogeneous geography
and extends from tens to hundreds of kilo-
meters.
• National and Global ScoJes—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 of 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 rtsvlt 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 (our basic monitoring objectives
and the scales of representativeness that are
generally most appropriate (or that objec-
tive.
TABLE I.—Relationship among monitoring
objectives and scale of representativeness
Montonng ob|*ctive
Appropmta SftinQ KJIWS
Mqhnl concentration
Population
Sou>ct impact
Gfrwai/Dackgtouna
Ifccro. n«od*€. nc'Q'to
knws ut»n>
Ndgnbomooe urban
Mere, maeie n«ig-
N»gneomooa
Subsequent sections of this appendix de-
scribe in greater detail the most appropriate
scales of representativeness and genert:
monitoring locations (or 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 tlu
scale of representativeness of a monitoring
station. The use of this physical basis for-lo
eating 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 (or
the interpretation and application of the
data. This will help to prevent mismatches
between what the data actually •epresen;
and 'vhat the data are interpreted to repre
7-4
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Chapter I—Environmental Protection Agoncy
Title 40—Protection of Environment
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
Jocal 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 Urge 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 must 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 tor
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 variation. load curves, etc.)
can often be obtained (: om the source. Area
source emission data by season, although
not 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 mede 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 da:a are also available.
but generally are not at 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 sitini 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.
KWS 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.
2.2 Total Suspended ^articulates
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Chapter I—Environmental Protection Agency
Title 40—Protection of Environment
AFP.D
uniform over a larger geographical area. Re-
gional scale measurements would be associ-
ated with rural areas.
• Middle Scalf.—Some data us»s associat-
ed with middle scale measurements for SO,
Include assessing the effects of control
strategies to reduce urban concentrations
(especially for the 3-hour and 24-hour aver-
aging times) and monitoring air pollution
episodes.
• Neighborhood Scale.—This scale applies
in areas where the SO. concentration gradi-
ent is relative)} flat (mainly suburban areas
surrounding the urban center) or in large
Auctions of small cities and towns. In gener-
al, these areas are quite homogeneous in
terms of SO, emission rates and population
density. Thus, neighborhood scale measure-
ments may be associated with baseline con-
centrations in areas of projected growth and
in studies of population responses to expo-
sure to SO, Also concentration maxima as-
sociated with air pollution episodes may be
uniformly distributed over areas of neigh-
borhood scale, and measurements taken
within such an area would represent neigh-
borhood, and to a limited extent, middle
scale concentrations.
• Urban Sea le.— Data from this scale
could be used for the assessment of air qual-
ity trends and the effect of control strate-
gies on urban .scale air quality.
• Regional Scale.— These measurements
would be applicable to large homogeneous
areas, particularly those which are sparsely
populated. Such measurements could pro-
vide information on background air quality
and interregional pollutant transport.
After the spatial scale has been selected to
meet the monitoring objectives for each sta
tion location, the procedures found in refer-
ence 2 should be used to evaluate the ade-
quacy of each existing SO, station and must
be used to relocate an existing station or to
locate any new SLAMS stations. The back-
ground material for these procedures
should consist of emission inventories, mete-
orological data, wind roses, and maps for
population and topographical characteris-
tics of specific areas of interest. Isopleth
maps of SO, air quality as generated by dif-
fusion models' are useful for the general de-
termination of a prospective area within
which the station is eventually placed.
***********
3. NrrwoRK DESIGN FOK NATIONAL Aw
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
Irvels. 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 expectec maximum concentra-
tions (generally neighborhood scale, except
micro scale for CO and urban scale for O,):
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.
3.1 Total Suspended Pa.rticula.tes (TSP)
Design Criteria for NAMS
Table 2 indicates the approximate number
of permanent stations needed in urban
areas to characterize national and regional
TSP air quality trends and geographical
patterns. The criteria require that the
number of stations in areas where urban
populations exceed 500.000 and concentra-
tions exceed the primary NAAQS range
from 6 to 8 but in small urban areas, no
more than two stations are required. A
range of monitoring stations is specified in
Table 2 because sources of pollutants and
local control efforts can vary from one part
of the country to another and therefore.
some flexibility is allowed in selecting the
actual number of stations in any one locale.
For those cases where more than one sta-
tion is required for an urban area, there
should be at least one station for category
(a) and category (b) objectives as discussed
in Section 3. Where three or more stations
arc required, the mix of category (a) and (b)
stations is determined on a case-by-case
basis. The actual number of NAMS and
their locations must be determined by EPA
Regional Offices and the State agencies sub-
ject to the approval of EPA Headquarters
(OANR). The EPA Headquarters approval is
necessary to insure that individual station;
conform to the NAMS selection criteria and
the network as a whole is sufficient in terms
of number and location for purposes of na-
tional analyses.
TABLE 2.—TSP Ntttonil Air Uonrtormg Stthon
Ottni (.Approamtte Number of Sunofts flpr Am i •
to.
concert- ooncen. cone*"-
fnerr »won-
**oh population. >HO.OOO •-« *-« 0-2
M*«um popUaton. 100.000-
SOO.OOO 4-6 2-4 0-2
Lo» population. SO.OOO-100.000 2-4 1-2 0
• 5»neuon ot «t*n anus «ne actual numb** of mown p*
area mu b* pntty aawwnau by EPA and in* SUM agency
by 20 percent o> more
'Me*umconcentrabl
• Low co
•dryNAAOS
ntr
v man Mcandvy NAAOS
The estimated number of TSP NAMS re-
quired nationwide will range from approxi-
mately 600 to 700. This range of stations is
based on a statistical analysis of the data
and computations of the probability of de-
tecting certain rates of change over a specif-
ic number of years. An assumption was
made that the variability of the data was 20
percent, i.e.. a 95 percent confidence inter-
val around the annual mean would be 20
percent. This assumption may be regarded
as a "ballpark figure." The sampling error
from an every sixth-day schedule would be
roughly 10 percent so an overall variability
of 20 percent may be regarded as a reason-
able approximation.
For TSP. it is unlikely that the same "ate
of change would apply throughout the
nation. Regional differences in the TSP
problem make it essential that the networks
also be useful for regional trend assess-
ments- In most practical applications, trends
will be assessed on the basis of 3-5 years of
data to minimize the impact of meteorologi-
cal influences. With 60 to 70 sites in each
geographical region, there is a reasonably
good chance of detecting 3-year trends of
more than 2 percent per year.
Using a TSP trend network of 600-700 sta-
tions there would be a reasonable chance of
determining 5-year trends of more than 3
percent per year In the medium population
cities with high TSP. but less than 50/50
chance of detecting 3-year trends of less
than 5 percent per year In any city. There-
fore, the overall range of 600-700 TSP
NAMS seems to be acceptable for the pur-
poses of national and regional trends. The
actual number of monitors in any specific
area would depend on local factors such as
meteorology, topography, urban and region-
al air quality gradients, and the potential
for significant air quality improvement or
degradation. Generally, the greatest density
of stations would oscur in the northeastern
Slates, where urban populations are Iftrge
and where pollutant levels are high.
Generally, the worst air quality in an
urban area should be used as the basis for
determining the required number of TSP
NAMS (see Table 2). This includes air qua]
ity levels, within populated parts of urban-
ized areas, that are affected by one or two
point sources of particulates if the impact of
the source(s) extends over a reasonably
broad geographic scale (neighborhood or
larger). Maximum air quality levels in
remote unpopulated areas should be ex
eluded as a basis for selecting TSP NAMS
regardless of the sources affecting the con
centration levels. Such remote areas are
7-6
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Chapter I—Environmental Protection Agency
THIe 40—Protection of Environment
more appropriately monitored by SLAMS or
6PM networks and/or characterized by dif-
fusion model calculations as necessary.
3.2 Sulfur Dioxide (SO,) Design Criteria
for NAMS
As with TSP monitoring. It is desirable to
have a greater number of NAMS in the
more polluted and densely populated urban
and multisource areas. "The data In Table 3
show the approximate number of perma-
nent stations needed in urban areas to char-
acterize the national and regional SO, air
quality trends and geographical patterns.
These criteria require that the number of
NAMS in areas where urban populations
exceed 500.000 and concentrations also
exceed the primary NAAQS may range from
6 to 8 and that in areas where the SOt prob-
lem is minor, only one or two (or no) moni-
tors are required. For those cases where
more than one station Is required for an
urban area, there should be at least one sta/
tion for category (a) and category (b) objec-
tives as discussed in Section 3. Where three
or more stations are required, the mix of
category (a) and (b) stations is determined
on a case-by-case basis. The actual number
and location of the NAMS must be deter-
mined by EPA Regional Offices and the
State agency, subject to the approval of
EPA Headquarters (OANK).
TASU 3—SO, National Air Monitoring Sta-
tion Criteria (Approximate Number of
Stations Per Area >•
Population category
Mqri Medium Loo
Cone*"- Cone*"- Concen-
•anon' vahon*
t*gf, population. > 500.000 .. S-8 «-6 0-2
•Weovm population. 100.000-
100000 ' 4-6 2-4 0-?
to- popuiaton SO.000-100.OOC 2-« 1-2 0
- Sancton of irten araat ane actual numow of tianont Of
area •* be iointty deierrraneo 9y EPA and the Sian agency
' Mqr, concentration—e«eeeO>% level of tne primary NAAQS
• Meoum concentraton—eiceeomg 60 percent of me level of
** pnmary or 100 percent of me tecondary NAAOS
•lo* concentration—4eu man 60 percent of me level of me
pnmjry or 100 percent of the lecondary NAAOS
The estimated number of SO, NAMS
which would be required nationwide ranges
from approximately 200 to 300. This range
in the number of stations is less than for
TSP. This is because there are more urban
areas with high TSP levels than with high
SO, levels. Also, the background air quality-
levels are higher for TSP than for SO,, and
thus air quality is more sensitive to SO,
emission changes than for TSP. Therefore.
fewer NAMS are needed on a national basis
for SO, than for TSP The actual number of
stations in any specific area depends on
local factors such as meteorology, topogra
phy. urban and regional air quality gradi-
ents, and the potential for significant air
quality improvements or degradation. The
greatest density of stations should be where
urban populations are large and where pol-
lution levels are high. Fewer NAMS are nec-
essary in the western States since concen-
trations are seldom above the NAAQS in
their urban areas. Exceptions to this are in
the areas where an expected shortage of
clean fuels indicates that ambient air qual-
ity may be degraded by increased SO, emis-
sions. In such cases, a minimum number of
NAMS is required to provide EPA with a
proper national perspective on significant
changes in air quality
Like TSP. the worst air quality in an
urban area is to be used as the basis for de-
termining the required number of SO,
NAMS (see Table 3). This Includes SO, air
quality levels within populated parts of ur-
banized areas, that are affected by one or
two point sources of SO, If the impact of
the source!s) extends over a reasonably
broad geographic scale (neighborhood or
larger). Maximum SO, air quality levels in
remote unpopulated areas should be ex-
cluded as a basis for selecting NAMS regard-
less of the sources affecting the concentra-
tion levels. Such remote areas are more ap-
propriately monitored by SLAMS or SPM
networks and/or characterized by diffusion
model calculations as necessary.
***********
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
Neighborhood
Urban
Regional
>cales applicable for SLAMJ
TSP
/
/
/
/
su2
•
/
/
•
LU
/
/
/
°3
/
/
/
/
N02
/
/
/
Scales required for NAMS
TSP
/
so2
•
CO
/
V
°3
/
V
NOj
/
/
Figure 5-2. Paniculate field data.
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-T7-018. June 1977. revised
December 1977
2. Ball. R. J. and C. 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 1877.
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 VS. Environmental
Protection Agency. Research Triangle Park.
NC. EPA Publication No. EPA-4SO/3-7S-
077. September 1975.
4. Ludwig. F. L and E. Shelar. Site Select-
ing for the Monitoring of Photochemical
Air Pollutants. Stanford Research Institute.
Menlo Park. CA. Prepared for \}£. 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 PR 72592.
Dec. 14. 19791
7-7
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Chapter I—Environmental Protection Agoncy
Title 40—Protection of Environment
APPENDIX E— PJIOBI SITING CRITERIA POR
AMBIENT A:n QUALITY MONITORING
1. Introducti:1"1.
2. Total Suspended Particulates (TSP>
2.1 Vertical Placement
2.2 Spacing from Obstructions
2.3 Spacing from Roadways
2.4 Other Considerations
3. Sulfur Dioxide (SO,)
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
5.1 Vertical and Horizontal Probe Place-
ment
5.2 Spacing from Obstructions
5.3 Spacing from Roads
6. Nitrogen Dioxide (NO,)
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
8. 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 general
•tation 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 me 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 meet for consistency but
are not a requirement.
2. TOTAL SUSPENDED PARTICULARS (TSP)
2.1 Vftica.1 Placement
The most desirable height for a TSP mon-
itor is near tht? breathing zone. Practical
considerations such as prevention of vandal-
ism, security, accessibility, availability of
electricity, etc.. require that the sampler be
elevated and that a range of acceptable
heights be specified. For TSP. the air intake
for a TSP monitor must be located 2 to IS
meters above ground level. The lower limit
was based on a compromise between ease of
sen-icing the sampler and the desire to
avoid reentrainment from dusty surfaces.
The upper limit represents a compromise
between the desire to have measurements
which are most representative of population
exposures, and the consideration for the lo-
cation of existing monitors.
2.2 Spacing from Obstructions
If the sampler is located on a roof or
other structure, then there must be a mini-
mum of 2 meters separation from walls.
parapets, penthouses, etc. No furnace or in-
cineration flues should be nearby. This sep-
aration distance from flues is dependent on
the height of the flues, type of waste or fuel
burned, and quality of the fuel (ash con-
tent). For example, if the emissions from
the chimney are the result of natural gas
combustion, no special precautions are nec-
essary except for the avoidance of obstruc-
tions, i.e.. at least 2 meters separation.
On the other hand, if fuel oil. coal, or
solid waste is burned and the stack is suffi-
ciently short so that the plume could rea-
sonably be expected to impact on the sam-
pler intake a significant part of the time.
other buildings/locations in the area that
are free from these types of sources should
be considered for sampling. Trees provide
surfaces for paniculate deposition and also
restrict airflow. Therefore, the sampler
should be placed at least 20 meters from
trees.
The sampler must also be located away
from obstacles such as buildings, so that the
distance between obstacles and the sampler
is at least twice the height that the obstacle
protrudes above the sampler. Sampling sta-
tions that are located closer to obstacles
than this criterion allows should not be clas-
sified as neighborhood, urban, or regional
scale, since the measurements from such a
station would closely represent middle scale
stations. Therefore, stations not meeting
the criterion should be classified as middle
scale. There must also be unrestricted air-
flow in an arc of at least 270 around the
sampler, and the predominant wind direc-
tion for the season of greatest pollutant
concentration potential must be included in
the 270' arc.
2.3 Spacing from Roads
A number of studies'"' support the con-
clusion that TSP concentrations decrease
with increasing height of the monitor and
distance from roads. Quite high concentra-
tions have been reported at monitors locat-
ed at a low elevation close to heavily trav-
eled roads. Moreover, monitors located close
to streets are within the concentrated
plume of particulate matter emitted and
generated by vehicle traffic. Except for spe
cial purpose monitoring studies where the
monitoring objective is to determine the
impact of a single source, ambient monitors
should not be located so as to measure the
plume of a single source. For TSP. ft is ap
propriate that ambient monitors be located
beyond the concentrated particulate plume
generated by traffic, and not so close that
the roadway totally dominates the meas-
ured ambient concentration.
An analysis of various monitoring studies'
shows that a llneir relationship between
sampler height and distance from roadways
defines a tone where the plume generated
by traffic greater than approximately 3.000
vehicles per day Is diminished. Figure 1 11
Justrates this relationship by showing two
xones where TSP SLAMS could be located
Zone A represents locations which are rec-
ommended for the neighborhood, urban and
regional scales and also for most middle
scale locations. Zone B represents locations
which should be avoided in order to mini-
mize undesirable roadway influences.
Because of the pronounced TSP air qua!
Ity gradients generally expected n-ar road
ways SLAMS which for certain reasons
cannot be located in Zone A and are located
in Zone B would be classified as having a
middle scale of representativeness. NAMS
must be located in Zone A. and it is recom
mended that most SLAMS be located in
Zone A.
In light of several street canyon studies
cited above, it appears that the street
canyon may confine resuspended roadway
dust and may not be a suitable location for
ambient monitors. However, since roads
with lower traffic (less than approximately
3.000 vehicles per day) generally do not gen-
erate a concentrated particulate plume.
monitors located in Zone B should not be
adversely influenced. Therefore, for those
cases where the traffic is less than approxi-
mately 3.000 vehicles per day. the monitor
must be located greater than 5 meters from
the edge of the nearest traffic lane and 2 to
IS meters above ground level (either Zone A
or Zone B).
In the case of elevated roadways where
the monitor must be placed below the leve:
of the roadway, then the monitor should be
located no closer than approximately 25
meters from the edge of the nearest traffic
lane. This separation distance applies for
those situations where the road is elevated
greater than 5 meters above the ground
level, and applies to all traffic volumes.
2.4 Other Considerations
Stations should not be located in an un-
paved area unless there is vegetative ground
cover year round so ihi>t the impact of reen-
trained or fugitive dusts will be kept to a
minimum. Addtional information on TSP
probe siting may be found in reference 10.
•See References at end of this Appendix.
"•See references at end of this Appendix.
7-8
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Chepter I—Environmental Protection Agoncy
Title 40—Protection of Environment
App. E
IB
I
o 10
ZONE C (UNACCEPTABLE)
ZONE A (ACCEPTABLE)
ZONE B NOT RECOMMENDED)
•APPLIES WHERE ADT >3 ooo
10 20 25 90
DISTANCE FROM EDGE OF NEAREST TRAFFIC LANE, meten*
Figur* I. Acceptable zone for siting TSP monitors.
3. SULFUR DIOXIDE (SO,)
3.1 Horizontal and Vertical Probe Place-
ment .
As with TSP monitoring, the most desir-
able height for an SO. monitor inlet proof
is near the breathing height Various fac-
tors enumerated before may require that
the Inlet probe be elevated Therefore, the
inlet probe must be located 3 to 15 meters
above ground level If the inlet probe is lo-
cated on the side of a building, then it
should be located on the windward side of
the building relative to the prevailing
winter wind direction. The Inlet probe must
also be located more than 1 meter vertically
or horizontally away from any supporting
•structure and also away from dirty, dusty
areas.
3.2 Spacing from. Obstruction}
No furnace or incineration flues, or other
minor sources of SO, should be nearby. The
separation distance is dependent on the
height of the flue*, type of waste or fuel
burned, and the quality of the fuel (sulfur
content). If the inlet probe is located on a
roof or other structure, it must be at least 1
meter from walls, parapets, penthouses, etc.
Th«> inlet probe should be placed more
than 20 meters from trees and must be lo-
cated away from obstacles and buildings.
The distance between the obstacles and the
Inlet probe must be at least twice the height
that the obstacle protrudes above the inlet
probe. Sampling stations that are located
closer to obstacles than this criterion allows
should not be classified as a neighborhood
scale, since the measurements from such a
station would closely represent middle scale
stations. Therefore, stations not meeting
the criterion should be classified as middle
scale. 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 concen-
tration potential must be Included In the
270* arc. If the probe is located on the side
of a building. 180* clearance is required. Ad-
ditional information on SO. probe siting cri-
teria may be found In reference 11.
7-9
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Chapter I—Environmental Protection Agency
Title 40—Protection of Environment
7. PIIOBI MATERIAL AND POLLUTANT SAMFLE
RESIDENCE TIME
For the re> ve cues. SO,. NO,. and O,.
special prolx . ateriaJ must be used. Stud-
ies """ have i>cen conducted to determine
the suitability of material* such as polypro
pylene. polyethylene, polyvinylchloride.
tygon. aluminum, brass, stainless steel.
copper, pyrex glass and teflon for 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 caseous
pollutants. Furthermore. EPA" has speci-
fied borosilicate glass or FEP 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 paniculate 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.M 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.
'*•" See References at end of this Appen-
dix.
'•See References at end of this Appendix
* See References at end of this Appendix.
ti- >i ggj References at end of this Appen-
dix.
6. 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 lim.ts 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 i for monitoring or establishing a moni-
toring station at that location. For estab-
lishing a new station, a waiver may be
framed 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
mould 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 mei
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 upp;r 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.
REFERENCES
1. Bryan. R.J.. R.J. Cordon, and H.
Menrk 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 75-
158.1
2. Teer. E.H Atmospheric Lead Concen-
tration Above an Urban Street. Master of
Science Thesis. Washington University. St.
Louis. MO. January 1971.
3. Bradway R.M.. F.A. Record, and W.E.
Brlanger 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. Freas. and E.M. Afify.
Quantification of Relationship Between
Monitor Height and Measured Paniculate
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 Paniculate 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 C.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 Paniculate Problem: Volume
1. National Assessment. CCA Technology
Division. Bedford. MA. U.S. Environmental
Protection Agency. Research Triangle Park
NC. EPA Publication No. EFA-450/3-75-
024. June 1976.
9. Pace. T.G. Impact of Vehicle-Related
Particulates on TSP Concentrations and
Rationale for Siting Hi-Vols in the Vicinity
of Roadways. OACJPS. 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 Tata!
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 C.E. Anderson. Opti
mum Site Exposure Criteria for SO, Moni-
toring. The Center for the Environment anc
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
letting Sites for Carbon Monoxide Monitor
Ing. Stanford Research Institute. Menlc
Park. CA. Prepared for U.S. Environmental
Protection Agency, hesearch 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. Pr-pared for U.S. Environ
mental Protection /.geney. 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
Class. Plastic and Metal Tubings. J. Air
Poll. Con. Assoc. 17:753. 1976.
16. Elfers. L.A Field Operating Cuide for
Automated Air Monitoring Equipment. U.S
NT1S 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. Altshuller. A.D. and A.C. Wanburg.
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 Pan 53.22. July 1976."
20. Butcher. S.S. and R.E. Ruff. Eifect of
Inlet Residence Time on Analysis of Atmos-
pheric Nitrogen Oxides and Ozone. 43:1890
1071
21. Slowik. A.A and E.B. Sansone Dfffu-
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 Techno!.. 3:483.1969.
(44 FR 27571. May 10. 1979: 44 PR 72592.
Dec. 14. 1979)
7-10
-------
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I
Excerpts of Ambient Monitoring Guidelines for
Prevention of Significant Deterioration (PSD)
EPA-450/4-80-012
S. 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 quality data.
3.2 Network Design
The design of a network for criteria and noncriteria 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.
3.2.1 Preoonstruction Phase
Information obtained 1n the ambient air quality analysis 1n 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.
7-12
-------
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 section 3.2.2). 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.
3.2.2 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 preconstructlon 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 3.2.1 regarding industrial process
fugitive particulate emissions, fugitive hydrocarbon emissions, and
ozone monitoring would also be applicable for the postconstruction
phase.
7-15
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3.2.3 Special Concerns for Location of Monitors
For the preconstruction and postconstruction phases, modeling 1s
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, 1f 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 modeled 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.
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.
t 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 nade 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
7-14
-------
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 from the corridor.
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 2,3.2 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.
7-15
-------
Review Exercise
Now that you've completed the assignment for Section 7, 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 objectives) 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, and
ground air pollutant concen- 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.
7-16
-------
8. Which of the following is(are) a NAMS categories)?
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
Match each of the following urban areas with its required number of TSP NAMS.
(Ques-J-ons 10-15)
10. Population: greater than 500,000; a. 6 to 8
TSP concentrations exceeding the
TSP primary NAAQS by 20
percent or more
11. Population: 100,000-500,000; b. 0
TSP concentrations greater than
the TSP secondary NAAQS but
not exceeding the TSP primary
NAAQS by 20 percent or more
12. Population: 50,000-100,000; c. 2 to 4
TSP concentrations less than
the TSP secondary NAAQS
IS. Population: 100,000-500,000; d. 4 to 6
TSP concentrations exceeding the
TSP primary NAAQS by 20
percent or more
14. Population: 50,000-100,000; e. 1 to 2
TSP concentrations greater than
the TSP secondary NAAQS but
not exceeding the TSP primary
NAAQS by 20 percent or more
15. Population: greater than 500,000; f. 0 to 2
TSP concentrations less than the
TSP secondary NAAQS
7-17
-------
Match each of the following urban areas with its required number of SOj NAMS.
(Questions 16-21)
16. Population: 100,000-500,000; a. 0
SOX concentrations less than
60 percent of the SO, primary
NAAQS or 100 percent of the
SO, secondary NAAQS
17. Population: 50,000-100,000; b. 1 to 2
SO, concentrations exceeding
the SO, primary NAAQS
18. Population: 100,000-500,000; c. 2 to 4
SO, concentrations exceeding
the SO, primary NAAQS
19. Population: greater than 500,000; d. 4 to 6
SO, concentrations exceeding the
SO, primary NAAQS
20. Population: 50,000-100,000; e. 0 to 2
SO, concentrations less than
60 percent of the SO, primary
NAAQS or 100 percent of the
SO, secondary NAAQS
21. Population: 50,000-100,000; f. 6 to 8
SO, concentrations exceeding
60 percent of the SO, primary
NAAQS or 100 percent of the
SO, secondary NAAQS but not
exceeding the SO, primary NAAQS
22. True or False? Generally, the worst air quality in an urban area should be used
as the basis for determining the required number of TSP and SO, NAMS for
the urban area.
23. TSP and SO, NAMS are required to be (?) scale monitoring stations.
a. middle
b. neighborhood
c. urban
d. regional
Select the TSP SLAMS/NAMS siting criterion specified in Appendix E of 40 CFR
58 for each of the following parameters. (Questions 24-27)
24. Height range of TSP sampler's air intake above ground level (meters):
a. 2 to 10
b. S to 10
c. 2 to 15
d. S to 15
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25. Minimum separation distance from walls, parapets, and penthouses for a roof-
located TSP sampler (meters):
a. 1
b. 2
c. 4
d. 10
26. TSP sampler's minimum separation distance from trees (meters):
a. 2
b. 5
c. 10
d. 20
27. Arc of unrestricted air flow around TSP sampler (degrees):
a. 90
b. 180
c. 270
d. 560
28. Appendix £ of 40 CFR 58 requires that a TSP sampler be located away from
obstacles such as buildings, so that the distance between an obstacle and the
sampler is at least v) times the height that the obstacle protrudes
above the sampler.
a. 2
b. 4
c. 5
d. 10
29. Appendix E of 40 CFR 58 requires that TSP NAMS be located greater than
(?) meter(s) from the edge of the nearest traffic lane of roadways.
a. 1
b. 3
c. 5
d. 10
SO. If a TSP sampler must be placed more than five meters below a roadway,
Appendix E of 40 CFR 58 recommends that the sampler be located no closer
than approximately (?) meters from the edge of the nearest traffic
lane of the roadway.
a. 5
b. 10
c. 25
d. 50
51. True or False? Appendix E of 40 CFR 58 recommends that TSP samplers
should not be located in an unpaved area unless there is year-around vegetative
ground cover.
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Select the SO, SLAMS/NAMS siting criterion specified in Appendix E of
40 CFR 58 for each of the following parameters. (Questions S2-S8)
32. Height range of SO, monitor's inlet probe above ground level (meters):
a. 2 to 10
b. S to 10
c. 2 to 15
d. S to 15
S3. Minimum horizontal separation distance of SO, monitor's inlet probe from its
supporting structure (meters):
a. 0.5
b. 1
c. 2
d. 5
34. Minimum vertical separation distance of SO, monitor's inlet probe from its
supporting structure (meters):
a. 0.5
b. 1
c. 2
d. 5
35. Minimum separation distance from walls, parapets, and penthouses for a roof-
located SO, monitor inlet probe (meters):
a. 0.5
b. 1
c. 2
d. 5
36. SO, monitor inlet probe's minimum separation distance from trees (meters):
a. 2
b. 5
c. 10
d. 20
37. Arc of unrestricted air flow for SO, monitor inlet probes which are not located
on sides of buildings (degrees):
a. 90
b. 180
c. 270
d. 360
38. Arc of unrestricted air flow for SO, monitor inlet probes which are located on
sides of buildings (degrees):
a. 45
b. 90
c. 135
d. 180
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39. Appendix E of 40 CFR 58 requires that the inlet probe of an SOj monitor be
located away from obstacles such as buildings, so that the distance between an
obstacle and the probe is at least (?) times the height that the obstacle
protrudes above the probe.
a. 2
b. 4
c. 5
d. 10
40. True or False? Appendix £ of 40 CFR 58 requires that intake sampling lines
for existing and new SOX SLAMS/NAMS be constructed of borosilicate glass,
FEP teflon, or their equivalent.
41. Appendix £ of 40 CFR 58 requires that sampling probes at SO*
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
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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
46. For post construction 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, (?) to (?) monitoring sites will be sufficient for most
situations.
a. 1, 3
b. 1,4
c. 2, 5
d. 2, 6
48. For post construction PSD ambient air quality monitoring in a multisource
setting, (?) 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 post construction PSD ambient air quality monitoring
in a remote area, (?) 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".
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51. True or False? PSD ambient air quality monitors should be placed in locations
which satisfy the definition of ambient air.
52. For PSD purposes, when monitoring TSP concentrations resulting from a
ground-level source, a TSP sampler's air intake should be located (?)
to (?) meters above ground level.
a. 2, 7
b. 2, 10
c. 2, 15
d. 5, 15
53. For PSD purposes, when monitoring SOt concentrations resulting from a
ground-level source, an SO, monitor's inlet probe should be located as close as
possible to (?) meter(s) above ground level.
a. 1
b. S
c. 10
d. 15
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Review Exercise Answers
Page(s) of
Section 7 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
9. c 6
10. a 6
11. c 6
12. b 6
IS. d 6
14. e.. 6
15. f 6
16. e 7
17. c 7
18. d 7
19. f 7
20. a 7
21. b 7
22. True 6-7
23. b 7
24. c 8
25. b 8
26. d 8
27. c 8
28. a 8
29. c 8
30. c 8
31. True 8
32. d 9
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Page(s) of
Section 7 of
Guidebook
33. b : 9
34. b 9
35. b .: 9
36. d 9
37. c 9
38. d 9
39. a 9
40. True 10
41. d 10
42. True 8
45. c 10
44. d 10
45. d 13
46. e 13
47. b IS
48. b 13
49. a IS
50. True 14
51. True 14
52. a 14
53. b 14
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TECHNICAL REPORT DATA
(Please reed Imuncrions on tht nvene I*fore completing)
1. REPORT NO.
EPA 450/2-81-081
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE _ . _-
APTI Correspondence Course 436
Site Selection for the Monitoring of SO.
TSP in Ambient Air: Guidebook
and
5. REPORT DATE
December 1981
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
t. 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
IS. SUPPLEMENTARY NOTES
Project Officer for this publication is R. E. Townsend, EPA-ERC, RTF, NC 27711
16. ABSTRACT
This Guidebook was developed for use in the Air Pollution Training
Institute's Correspondence Course 436, "Site Selection for the Monitoring
of S02 and TSP 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 S02 and TSP Monitoring
Procedures and Criteria for Site Selection for S02 and TSP Monitors
Rationale for SO- and TSP Monitor Siting Criteria
Network Design and Probe Siting Criteria for S02 and TSP SLAMS,
NAMS, and PSD Monitoring Stations
The Guidebook is designed for use in conjunction with "Optimum Site
Exposure Criteria for S02 Monitoring" (EPA 450/3-77-013) and "Selecting
Sites for Monitoring Total Suspended Particulates" (EPA 450/3-77-018).
17.
KEY WORDS AND DOCUMENT ANALYSIS
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
IB. D.STR.BUT.ON STATEMENT Unlimited. Available
from the National Technical Information
Service, 5285 Port Royal Rd.,
Springfield, VA 22161
18. SECURITY CLASS (nit Report)
unclassified
21. NO. OF PAGES
83
20. SECURITY CLASS (THupagt)
unclassified
22. PRICE
KPA Form 2220-1 <»-73)
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