EPA-450/2-77-010
June 1977
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
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EPA-450/2-77-010
AIR MONITORING STRATEGY
FOR
STATE IMPLEMENTATION PLANS
Standing Air Monitoring
Work Group
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
June 1977
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This report is issued by the Environmental Protection Agency to report
technical information of interest to a limited number of readers. Copies
are available free of charge to Federal employees, current contractors
and grantees, and nonprofit organizations - in limited quantities - from
the Library Service Office (MD-35), Research Triangle Park, North Carolina
27711; or, for a fee, from the National Technical Information Service,
5285 Port Royal Road, Springfield, Virginia 22161.
Publication No. EPA-450/2-77-010
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
THE ADMINISTRATOR
FOREWORD
Concern for the quality of air monitoring data has increased
substantially over the past few years and, likewise, so has the
response to this concern.
The recommendations of this strategy document were developed
through a partnership effort of State, local and Federal air
pollution control agencies. They are intended to improve the overall
quality of air monitoring data, increase the effectiveness of current
monitoring operations, and provide State and local agencies with
the flexibility needed to meet their variety of data needs.
This document principally presents overall air monitoring
strategy concepts with a minimum of rigid schedules and detailed
guidelines. It should be used as the basis for the development of
future long-range air monitoring plans. Air monitoring is a dynamic
process; measurement methods and techniaues change or are improved
and, consequently, our monitoring plans will need periodic
reevaluation and updatina. Hopefully, however, the strategies
recommended herein will provide sufficient stabilization to our
future monitoring programs thereby enabling us, with minimum
disruption to ongoing efforts, to achieve the goal of improved
data quality and increased air monitoring effectiveness.
To reach our goal, it is vital that we continue the partnership
efforts displayed in. developing the strategy described herein.
I request each State and local air pollution control agency to
actively and cooperatively participate with this agency in the
development and implementation of improved air monitoring plans based
upon the overall concepts outlined in this report.
Despite the difficulties of the tasks ahead, through your combined
actions, our air monitoring proopafril.Bs welly^fy oyr total air pollution
control efforts, will indeed
s M. Costle
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IV
ACKNOWLEDGMENTS
This report was prepared through the efforts of many
individuals: representatives of State and local air pollution
control agencies and their respective organizations, as well
as spokesmen for the Environmental Protection Agency's headquarters
and regional offices. The principal contributors are listed below:
STANDING AIR MONITORING WORK GROUP
R. Neligan, Chairman Office of Air and Waste Management
W. Auberle Association of Local Air Pollution Control
Officials (ALAPCO)
R. Col lorn State and Territorial Air Pollution
Program Administrators (STAPPA)
W. Cox Office of Air and Waste Management
F. Biros Office of Enforcement
E. Fitzpatrick Region I Office
T. Mauser Office of Research and Development
G. Helms Region IV Office
B. Korb Office of Planning and Management
C. Simon Region II Office
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CONSULTATION AND REVIEW GROUPS
STAPPA
R. Valentinetti
C. Barden
H. Williams
M. Michael
B. Becker
State of Vermont
State of Texas
State of Indiana
State of Idaho
State of Wisconsin
C. Rob 1 son
W. Reilly
H. Bergman
ALAPCO
Jefferson County, Alabama
City of Philadelphia
City of Cleveland
ADDITIONAL CONTRIBUTORS
G. Akland
N. Beloin
W. Bishop
F. Burmann
J. Clements
S. Coerr
C. Devereux
R. Duprey
J. Hammerle
A. Hoffman
W. Keith
M. Martinez
H. Richter
H. Slater
S. Sleva
D. Stonefield
The Standing Air Monitoring Work Group gratefully acknowledges
the assistance provided by State and local control agencies and
EPA offices who reviewed and made suggestions for improving the
strategy issue papers used as the basis for this document.
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VI
CONTENTS
Page
LIST OF TABLES viii
LIST OF FIGURES ix
ABBREVIATIONS x
I. EXECUTIVE SUMMARY 1
Origin and Goals of Study 1
Major Findings 2
Summary of Initial Recommendations 3
Summary of Comments on Initial Strategy Document.. 6
Summary of Revised Recommendations 8
Implications for Resources and Planning 12
II. INTRODUCTION 15
Origin and Mission of the Standing Air
Monitoring Work Group 15
Initial Tasks of the SAMWG 16
SAMWG Approach to Monitoring Problems 20
Issue Paper Recommendations and Air
Monitoring Strategy Document 22
Use of Strategy Document 23
III. AMBIENT AIR MONITORING PROGRAM 25
Introduction 25
Future Ambient Program 27
State and Local Ambient Monitoring Stations 29
National Air Quality Trend Stations 34
General Criteria for NAQTS 36
Special Purpose Monitoring 41
Meteorological Data to Support
Ambient Monitoring Activities 43
Summary of Recommendati ons 46
IV. SOURCE MONITORING PROGRAM 48
Introduction 48
Background Information on Point Source
Monitoring (PSM) Data 49
Point Source Monitoring Uses and Requirements 50
Point Source Ambient Monitoring Data 54
Point Source Emission Monitoring Data 55
Air Quality Simulation Modeling 61
Source/Emission Inventory 63
Summary of Recommendations 72
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CONTENTS (continued)
Page
V. FUTURE MONITORING PROGRAM FOR NON-CRITERIA
POLLUTANTS 77
Introduction 77
Baseline Investigations of Non-Criteria
Pollutants 79
Anticipatory Monitoring Research and
Development 82
Functional Management of Non-Criteria
Pollutant Monitoring 85
Implementation 87
Summary of Recommendations 87
VI. QUALITY ASSURANCE ACTIVITIES FOR AMBIENT
AND SOURCE MONITORING 89
Introduction 89
Development and Implementation of Air
Pollution Measurement Quality Assurance
Programs 90
Minimum Quality Assurance Programs 91
Summary of Recommendations 95
VII. ANALYSIS AND INTERPRETATION OF AIR QUALITY
INFORMATION 96
Data Analysis and Evaluation 96
Air Quality Display and Reporting 99
Summary of Recommendations 108
VIII. ANTICIPATED IMPACT OF STRATEGY 110
Introduction 110
Overall Impact of Monitoring Strategy 110
Resources for Ambient Air Monitoring 113
IX. IMPLEMENTATION OF STRATEGY 124
Introduction 125
Identification of Major Strategy Actions 127
APPENDIX A COMPILATION OF QUESTIONS CONCERNING
THE AIR MONITORING PROGRAM
APPENDIX B SUMMARY OF ISSUES AND RECOMMENDATIONS
FROM ISSUE PAPERS
APPENDIX C NETWORK DESIGN AND INSTRUMENT SITING
FOR NAQTS AND SLAMS
APPENDIX D DATA REPORTING AND HANDLING,
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LIST OF TABLES
Table
II-l Principal Uses of Aerometric Data
by Use Level 18
IV-1 Continuous Emission Monitoring 58
V-l Tentative List of Non-Criteria Pollutants 80
V-2 Principal Organizations Involved in
Non-Criteria Pollutant Monitoring 81
VIII-l State and Local Control Agency Expenditures
on Air Pollution Control Activities Ill
VI11-2 State, Local, and Federal Expenditures on
Air Monitoring Activities, FY-1975 112
VI11-3 Estimated Resources Impact of
SAMWG Strategy 114
VIII-4 Current Resource Estimates for Operation
of National Air Quality Trend Stations
(NAQTS) and State/Local Air Monitoring
Station (SLAMS) 116
VIII-5 Data Use: Judge Attainment of NAAQS 120
VI11-6 Data Use: Revise SIP Control Strategies 121
VIII-7 Data Use: Air Quality Progress and Trends 122
VI11-8 Data Use: New Source Review/Present
Significant Deterioration 123
IX-1 Schedule of Strategy Action Items 128
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IX
LIST OF FIGURES
Figure Page
VII-1 Isopleths of Annual Average TSP
Concentrations for the (NY, NJ,
Conn, AQCR) in 1971 and 1974 102
VI1-2 Population Exposed to Annual
TSP (NY, NJ, Conn. AQCR) 103
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LIST OF ABBREVIATIONS
AAQS Ambient Air Quality Standards
A&HM Air and Hazardous Materials (element of EPA
Regional Offices)
AQCR Air Quality Control Region
AQDHS Air Quality Data Handling System
CAA Clean Air Act
CDHS Comprehensive Data Handling System
CDS Compliance Data System
CEQ Council on Environmental Quality
CFR Code of Federal Regulations
CO Carbon Monoxide
DSSE Division of Stationary Source Enforcement (EPA HQ
element)
EIS Emissions Inventory System
ESECA Energy Supply and Environmental Coordination Act
of 1974
FEA Federal Energy Administration
FMVCP Federal Motor Vehicle Control Program
FOI Freedom of Information (legislation, request, etc.)
FSM Fixed Station Monitoring
FY Fiscal Year
HATREMS Hazardous and Trace Substance Emissions System
HC Hydrocarbons
HDV Heavy Duty Vehicle
ID Identification
LDV Light Duty Vehicle
NAAQS National Ambient Air Quality Standard(s)
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NADB
NAQTS
NASN
NEDS
NEDSXREF
NEPA
NESHAPS
NMHC
NMOC
N02
NO
NOX
NSPS
OAQPS
ORD
°3
PSD
PSI
PSM
QA
RAPS
RO
S&A
National Air Data Branch, National Aerometric
Data Bank
National Air Quality Trend Station(s)
National Aerometric Surveillance Network
National Emission Data System
Number providing cross reference between NEDS and
enforcement data systems
National Environmental Policy Act of 1969
National Emission Standards for Hazardous Air
Pollutants
Non-Methane Hydrocarbons
Non-Methane Organic Materials
Nitrogen Dioxide
Nitric Oxide
Nitrogen Oxides
New Source Performance Standards
EPA's Office of Air Quality Planning and Standards
EPA's Office of Research and Development
Ozone
Prevention of Significant Deterioration of Air
Quality
EPA's Pollutant Standards Index
Point Source Monitoring
Quality Assurance
St. Louis Regional Air Pollution Study
EPA Regional Office
Surveillance and Analysis (element of RO)
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SAMWG Standing Air Monitoring Work Group
SAROAD Storage and Retrieval of Aerometric Data (EPA's
ambient air quality data system)
SCS Supplemental Control System
SIP State Implementation Plan
SLAMS State and Local Air Monitoring Station(s)
SMSA Standard Metropolitan Statistical Area
S02 Sulfur Dioxide
SPM Special Purpose Monitoring
TCP Transportation Control Plans
TSP Total Suspended Particulate
VMT Vehicle Miles Traveled
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CHAPTER I
EXECUTIVE SUMMARY
ORIGIN AND GOALS OF STUDY
In October 1975, at the request of the Deputy Administrator of
the Environmental Protection Agency (EPA), Mr. John Quarles, a Stand-
ing Air Monitoring Work Group (SAMWG) was established. The Work
Group was to critically review and evaluate current air monitoring
activities and to develop, for consideration by control agency manage-
ment, air monitoring strategies which would help to correct identified
problems, improve overall current operations, and adequately meet
projected five-year air monitoring goals. Members of the Work Group
represented State and local air pollution control agencies and EPA
program, and regional offices. Since the great majority of air
monitoring activities are conducted by State and local agencies,
their views and opinions were widely sought throughout the study
period.
The initial concern of the project was to identify air monitor-
ing data needs and to delineate the problems involved in meeting
them. Any recommendations for corrective action were to be tempered
by the realization that current monitoring resources were limited
and any additional resources in the future were uncertain.
SAMWG developed an outline of the basic activities of a com-
prehensive air monitoring program and used these as the major themes
of discussion in writing a series of nine issue papers (see Appendix
B). Throughout the study, heavy emphasis was placed on the impor-
tance of quality assurance programs in producing timely data that
are complete, precise, accurate, and comparable.
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The nine issue papers and accompanying recommendations were
extensively circulated for the review of State and local agencies
and EPA offices. As a result of the comments and suggestions made
by the reviewers of the issue papers and the Work Group's earlier
identification of monitoring issues, SAMWG compiled a list of a
number of air monitoring activities that needed attention, as well
as recommendations for improvement. A summary of these major
findings are as follows:
MAJOR FINDINGS
Ambient Criteria Pollutant Networks
• Too few/too many monitors
• Monitor siting deficiencies
• Much data of unknown quality
• Quality control and method deficiencies
Non-Criteria Pollutant Monitoring
• Lack of coordination of monitoring activities.
• Deficiencies in analytical instrumentation and procedures
• Insufficient lead time for developing new methods
• Data of unknown precision and accuracy
Existing State Implementation Plan Ambient Monitoring Regulations
• Inflexible for current state Implementation Plan (SIP) needs
• Monitor siting not addressed
Source Monitoring
• Need for comprehensive inventories
• Need for more point source ambient monitoring by private
industry
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• Quality control and method deficiencies-
Monitoring Resources
• Receive equitable portion of total abatement and control
program resources
Data Reporting
• Much unneeded data to EPA central data bank
• Data not timely or complete
• Deficiencies in specific site information
Data Analysis and Presentation
• Need for more public-oriented information
• Need for more timely reports
From the Work Group's findings and the recommendations of the
review group, SAMWG proceeded to prepare a draft of an overall
air monitoring strategy for SIP. The major SAMWG recommendations
presented in the December 1976 draft of the strategy document are
presented below.
SUMMARY OF INITIAL RECOMMENDATIONS
• EPA should expand its efforts to implement a formal and
comprehensive quality assurance program. The proportion of
monitoring resources used in quality assurance is inadequate
(approximately 6 percent) and should be increased over the
next 5 years to approximately 10 to 20 percent, depending on
the type of monitoring program being implemented.
• EPA should modify existing monitoring regulations (40 CFR
51.17) to provide for:
a. A carefully planned supplement of State and Local Air
Monitoring Stations (SLAMS) whose size and distribution
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is largely determined by the needs of Regional Offices, States
and local air pollution control agencies;
b. A small but well-defined core of National Air Quality
Trend Stations (NAQTS) to minimally meet national needs
for trend and SIP evaluations; and
c. A plan for special purpose monitoring (SPM) tailored
to augment data from NAQTS and SLAMS.
• EPA should revise existing SIP reporting regulations (40 CFR
51.7) to reflect the diminished need for large quantities of
data at the national level.
• EPA should provide updated guidance to State and local air
pollution control agencies for the collection of the source
emission inventory information needed for State Implementation
Plan activities, national strategy development and assessment,
national trend analysis, and area-specific diffusion modeling.
• EPA should determine the feasibility of establishing a
national clearinghouse of monitoring information. The clear-
inghouse would provide a source of information about air
monitoring activities undertaken or authorized by governmental
agencies; it would not maintain actual measurement data. It
would, however, contain information about the nature and scope
of particular monitoring activities so that users could obtain
additional information or data, as necessary, from the appro-
priate agency.
• State and local agencies should complete baseline emission
inventories for all appropriate criteria pollutants with pri-
orities determined by the severity of the specific problem in
each county. Point source inventories should include all
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sources that have a potential for emitting 100+ T/year of a
criteria pollutant.
• Each action designed to improve the monitoring program which
will cause significant shifts in resources should be phased in over
a period of time sufficient to avoid disruption of the agency's program.
• EPA should take steps to establish a clear division of
responsibility among its program and research offices for the
establishment and conduct of non-criteria pollutant monitoring.
A program should be developed to provide for baseline investi-
gations of non-criteria pollutants and for anticipatory non-
criteria pollutant monitoring research and development.
• Individual users of data handling systems should develop
plans to modify them if their needs are distinctly different
from, or exceed, the capabilities of NEDS/SAROAD and related
systems. EPA should plan to provide a limited amount of
technical assistance to users in evaluating, modifying, or
developing new data handling and software systems, and seek
to assure overall system compatibility.
• EPA should foster the standardization and use of statis-
tical and simulation modeling techniques required to support
the air program activites of EPA regional offices and State
and local air pollution control agencies.
The December draft strategy document was then extensively cir-
culated for review by 50 State and some 180 local agencies and EPA
offices. In January 1977, four workshops were also held in order
to provide agencies the opportunity for first-hand open discussions
of the overall concepts of the strategy, as well as of the specific
details of the various monitoring program elements. Over 130
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persons attended the workshops and approximately 50 persons sent in
written comments and suggestions.
There was general agreement with the overall concepts and
approach of the proposed air monitoring strategy. In several
instances where disagreements did occur, they were found to be the
result of the need for additional detail and further clarification
of the specific concept in question. A summary of the more frequent
and major comments follows.
SUMMARY OF COMMENTS ON INITIAL STRATEGY DOCUMENT
• Reviewers unanimously agreed that good quality data is
absolutely necessary. They added, however, that additional
resources would be required to fully implement the recommended
minimum quality assurance program.
" Several reviewers stated that all SIP monitoring activities
should have a minimum quality assurance program rather than
treating it as a necessity for National Air Quality Trend
Stations (NAQTS) and a somewhat lower priority for State and
Local Air Monitoring Stations (SLAMS) and Special Purpose
Monitoring (SPM).
• A large number of reviewers stated that the definition of
potential and actual source emissions needs clarification.
' A majority of the workshop participants rejected the pro-
posed concept of only reporting baseline emission inventory
data to EPA. However, they emphasized that a reporting time
of more than 90 days after the end of the calendar year was
necessary in order to provide a more comprehensive annual
emissions inventory data report.
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• Reviewers agreed with the concepts of non-criteria pollu-
tant monitoring-, however, they stressed that EPA should look
to the States for more input to this important monitoring area.
• The reviewers felt that the strategy gives the impression
that a general across-the-board reduction in monitoring activities
and/or resources was recommended. In addition, they felt
the strategy implied that the NAQTS were first priority and the
SLAMS were lower priority and second-class stations.
• Many of the workshop participants felt that submission of
one-half of the filters from the NAQTS total suspended parti-
culate (TSP) sites was not acceptable. States having the
capability to do the filter analyses for non-criteria pollu-
tants and using acceptable quality assurance practices should
be allowed to do the analyses and merely submit the data to
EPA.
• A number of the reviewers disagreed with SAMWG's recommenda-
tion of having CO street canyon sites included as a NAQTS site.
They suggested that this type of monitoring is more appropriately
classified as SPM or SLAMS monitoring.
• A majority of the participants emphasized that siting cri-
teria should be handled as a formal guidance document rather
than a Federal regulation.
• Several reviewers suggested that SAMWG should modify the
recommendation "that point sources not be required to routinely
establish permanent full-scale point source ambient monitoring
(PSAM) programs." They felt that this should be an option of
the State, local agency, or EPA regional office.
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• There was general agreement with the overall goal of
implementing the strategy over a five-year period. However,
there were serious concerns that some States could not
implement the entire strategy in five years due to resource
limitations. They stressed the need for more flexible goals
that will allow negotiations within the 105 Grant procedures that
will produce a realistic and effective long-range monitoring plan.
• A number of regional offices suggested that it was important
to emphasize that the Regions would need more State and local
data than EPA headquarters.
Extensive discussions were held and serious consideration was
given to the comments and suggestions offered by the reviewers and
workshop participants. Where feasible, appropriate changes were
incorporated into the overall body of the document, the detailed
recommendations in the various chapters, and the revised summary
of recommendations in this chapter. The revised summary of recom-
mendations is as follows:
SUMMARY OF REVISED RECOMMENDATIONS
• Efforts should be expanded to implement a formal and
comprehensive quality assurance program. The proportion of
monitoring resources used in quality assurance is inadequate
(approximately 6 percent) and should be increased over the next
five years to approximately 10 to 20 percent, depending on the
type of monitoring program being implemented. Initiation of
the quality assurance program may require as much as 25 percent
of the monitoring resources. However, once implemented, a resource
reduction should occur. All monitoring activities which are
relatable to SIP 's should be under a quality assurance program.
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• EPA should modify existing monitoring regulations (40 CFR 51.17)
to provide for:
a. A carefully planned network of State and Local Air
Monitoring Stations (SLAMS) whose size and distribution
is largely determined by the needs of State and local air
pollution control agencies in meeting their respective
SIP requirements.
b. A small but well-defined core of National Air Quality
Trend Stations (NAQTS) to minimally meet national needs
for trend and SIP evaluations. These stations essentially
would be a subset of existing SIP/SLAMS monitoring networks.
c. A plan for Special Purpose Monitoring (SPM) tailored
to augment data from NAQTS and SLAMS.
• EPA should revise existing SIP reporting regulations, both
ambient and source (40 CFR 51.7), to reflect changes in the reporting
of source inventory and ambient data to EPA central data banks.
Data gathered from NAQTS should be received in EPA headquarters
within 90 days of the end of a calendar quarter. EPA regional
offices should negotiate with State and local air pollution control
agencies regarding the format, frequency, and timeliness of
data required from SLAMS and on an optimum handling procedure
for NAQTS data. Regional offices storing SLAMS data in machine
readable form must be made through the appropriate regional
office. An inventory of SLAMS must be provided to EPA on an
annual basis. EPA should consider some form of technical
assistance to State/local agencies with their own data handling
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systems to assure adequate performance of data submittal require-
ments. Control agencies should submit to EPA updated comprehensive
emission inventories annually instead of the current semiannual
submissions. As a minimum, the year of record should be updated.
The inventories should continue to include criteria pollutants
point source actual emissions. The area sources should also
continue to be reported on at the county level for those areas where
NAAQS are either violated or threatened. As additional air
quality standards are promulgated, the emission reporting level
for each new pollutant should also be specified. Data should be
submitted to EPA, in the NEDS fixed format machine readable form,
within 180 days after the end of a calendar year. Data may be
submitted more frequently as they become available.
• EPA should provide updated guidance to State and local air
pollution control agencies for the collection of the source
emission inventory information needed for SIP activities, national
strategy development and assessment, national trend analysis,
and area-specific diffusion modeling.
• EPA should determine the feasibility of establishing a national
clearinghouse of monitoring information. The clearinghouse
would provide a source of information about air monitoring activities
undertaken or authorized by governmental agencies; it would not
maintain actual measurement data. It would, however, contain
information about the nature and scope of particular monitoring
activities so that users could obtain additional information of
data, as necessary, from the appropriate agency.
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• Each action designated to improve the monitoring program which
will cause significant shifts in resources should be phased in
as resources become available or can be redirected.
t The resources to initiate the monitoring strategy should
come to the extent possible from a real location and more efficient
use of currently available resources. SAMWG believes that the
monitoring strategy is a minimally adequate program for SIP data
needs. However, it is also felt that in order to implement
the SIP monitoring strategy, additional resources will be needed
and should be provided to control agencies.
t EPA should take steps to establish a clear division of respon-
sibility among its program and research offices for the establishment
and conduct of non-criteria pollutant monitoring. EPA should seek
significant State and local agency input to the activity of non-
criteria pollutant monitoring. A program should be developed
to provide for baseline investigations of non-criteria pollutants
and for anticipatory non-criteria pollutant monitoring research
and development.
• Individual users of data handling systems should develop plans
to modify them if their needs are distinctly different from, or
exceed, the capabilities of NEDS/SAROAD and related systems.
However, the NEDS/SAROAD coding and file format should be the
basis for such systems. EPA should plan to provide a limited
amount of technical assistance to users in evaluating, modifying,
or developing new data handling and software systems, and seek
to assure overall system compatibility.
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• EPA should foster the standardization and use of statistical
and simulation modeling techniques required to support the
air program activities of EPA regional offices and State and
local air pollution control agencies.
IMPLICATIONS FOR RESOURCES AND PLANNING
The finding that air monitoring activities related to SIP's
generally have an equitable portion of the total abatement and con-
trol program resources, led SAMWG's thinking toward a reallocation
of the total resources available for monitoring so that they
would be used more effectively. Since substantial additional
resources are not generally expected to be available in any one
year, SAMWG developed a minimally adequate program to be
phased in over a period of time. The phased approach was taken
to minimize the resource impact of the recommendations in any one
year. Even with this approach, SAMWG finds that implementation
of the strategy will require more resources, especially
for expanded quality assurance programs and the purchase of
new instruments to replace obsolete or unacceptable analyzers.
In order to provide some overall guidance and structure
for the implementation of this strategy, SAMWG suggests that
EPA's Annual Program Guidance documents be used to specify
the objectives to be stressed during the next and future fiscal
years. This annual guidance will include strategy objectives for
both EPA regional offices and headquarters components, as well
as State and local programs. The Annual Program Guidance
should continue to have input from SAMWG or its successor. This
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group should have increased State and local agency participation.
In preparing their annual program plans, all EPA offices are
expected to commit themselves to accomplishment of as many
of these desired objectives as are possible within their resources.
Necessarily, many of the regional office air monitoring objectives
will require action by State and/or local agencies. For FY-1978,
SAMWG has recommended that the Regional Offices work closely
with their respective States to prepare plans and schedules
for the implementation of SAMWG's major recommendations. This
approach was proposed at the workshops held in January, 1977 as
a means of ensuring that implementation was closely tailored to the
individual needs and resources of each agency. To allow State
and local agencies the latitude implied by this approach, SAMWG
has revised Chapter IX to reduce the number of items to be
implemented under a uniform schedule. Implementation of the
minimum quality assurance program, however, remains a firm
requirement for the first year. The regional offices are also
expected to have an active role in assisting control agencies in
program evaluation and providing technical assistance in new,
specialized or problem areas of air monitoring. In some cases,
the EPA regional offices may choose to incorporate some portion of
these objectives as outputs expected under an agency's 105 Grant
Program.
Resource constraints must be carefully considered along
with the fact that State and local agencies will have changing
needs for monitoring information over the next five years. Also,
it is likely that the state-of-the-art in air monitoring will
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advance during the five-year period. For these reasons,
implementation will be closely coordinated through the Annual
Program Guidance and through periodic re-evaluations which will
consider air monitoring within the overall context of the Air
Program. As a result, this strategy document contains a minimum
of rigid schedules and should not be viewed as a set of static
requirements for judging progress.
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CHAPTER II
INTRODUCTION
ORIGIN AND MISSION OF THE STANDING AIR MONITORING WORK GROUP
In September 1975, the Deputy Administrator of the Environ-
mental Protection Agency, Mr. John Quarles, requested that a con-
tinuing group be formed to review air monitoring activities and to
develop and oversee the implementation of an overall strategy to
govern them. More specifically, this body, which was established
in October 1975 as the Standing Air Monitoring Work Group (SAMWG),
was to (1) determine how much and what kinds of monitoring data
were needed to meet the Agency's principal air program goals, (2)
ascertain, by a comprehensive review of ambient and source moni-
toring activities being conducted or fostered by the Agency, the
extent to which these needs were being met, and (3) identify major
air monitoring issues and present them in decision papers for
approval within and outside EPA and for subsequent incorporation
in a five-year monitoring strategy. It should be stressed that
SAMWG's primary concern with air monitoring was its usefulness as
an instrument for supporting air pollution control and abatement
efforts and promoting compliance with air quality standards. Air
monitoring for research and development programs would be addressed
only to a limited extent, mainly in the issue paper on non-criteria
pollutants.
It was Mr. Quarles1 special concern, in view-of the central
role played by monitoring in the improvement of air quality, that
SAMWG's recommendations for future strategies should evolve from a
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partnership between EPA and the States, working together to assure
that needed air quality data be obtained within the limits of the
resources made available by Federal, State and local governments
now and in the foreseeable future. In recognition of the fact that
the bulk of routine monitoring operations are conducted by State
and local control agencies, SAMWG made a firm commitment to obtain
their active participation in reviewing and evaluating current air
monitoring activities. This was done largely through the series of
nine issue papers, which were widely circulated in draft to State
and local agencies for their comments. In this way, the Work
Group acquired the views of management and decision-making officials
on strategies for effective air monitoring as well as the comments on
air monitoring specialists on technical matters. These views and
comments were incorporated in the final version of the issue papers.
INITIAL TASKS OF THE SAMWG
For the purpose of the Work Group study, it was necessary to
clarify the use of the term "air monitoring." In common usage,
air monitoring is often synonymous with the operation of a net-
work of ambient monitoring stations at fixed sites. However, the
definition of air monitoring used by the Work Group is somewhat
broader. As used in the issue papers developed by the Work Group,
"air monitoring" refers to activities which are related to estab-
lishing the concentration or quantity of a pollutant. These
activities are divided into general ambient air monitoring, source
emission monitoring and point source ambient monitoring.
Ambient monitoring generally implies the measurement, esti-
mation, or projection of pollutant concentrations in the air.
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Source monitoring involves gathering data about the pollutant
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18
TABLE II-l. PRINCIPAL USES OF AEROMETRIC DATA BY USE LEVEL *
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
USES
Judge attainment/non-attainment of TSP NAAQS
Evaluate progress in achieving/maintaining
NAAQS or state standards
Develop or revise SIP's to attain/maintain
TSP NAAQS
New Source Review and prevention of signi-
ficant deterioration
Develop or revise national TSP control
policies (e.g., NSPS, tall stacks, SCS)
Model development and validation
Energy Supply and Environmental
Coordination Act (ESECA)
Support enforcement actions
Public information (e.g., air quality indices)
Health research/establish standards
Develop or revise local control strategy
EPA
HQ
1
1
1
1
2
3
1
2
1
3
1
EPA STATE/LOCAL
RO AGENCIES
3
3
3
3
N/A
3
2
3
1
3
2
3
3
3
3
N/A
3
3
3
3
3
3
12. Determine specific cause of pollution in
an area 1 2 3
13. Determine nature of air pollution problem
in an area 33 3
*Use level refers to the detail, extent and frequency of reporting
of data needed by the user for the stated purpose.
1. Refers to a low level of detail, extent, and frequency of reporting
2. Refers to a moderate level of detail, extent, & frequency of reporting
3. Refers to a high level of detail, extent, and frequency of reporting
N/A - Not applicable
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monitoring by use level. This is given in summary form in Table
II-l. A cursory examination of this summary not only suggests the
importance of monitoring data for all phases of the air program,
but also shows how needs vary according to the functions and re-
sponsibilities of the user.
Delineation of Air Monitoring Problems
Considering the broad problems identified above, the
variety of current monitoring activities, and the data use list of
Table II-l, SAMWG developed an extensive list of issues facing
agencies or programs involved in air monitoring activities. The
following are examples of the sort of questions which were raised.
• Are current State Implementation Plan (SIP) monitoring
networks adequate in terms of the quantity and location of stations
established for the purpose of tracking the attainment and main-
tenance of the National Ambient Air Quality Standards (NAAQS)?
* Can valid national air quality assessments be made
with data from a smaller number of monitoring stations than are
now reporting to EPA?
• What specific needs for source and emissions data are
not being met by current activities?
A compilation of the questions which surfaced during the
early stages of the SAMWG study is included in Appendix A. These
questions were categorized under the broad topics listed below.
• Quality Assurance Programs
• Adequacy of SIP Ambient Monitoring Networks
• Source and Emission Data
• Air Quality Reporting
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* Monitoring Non-Criteria Pollutants
* Point Source Monitoring
• Data Processing and Support Systems
• Use of Air Quality Models
SAMWG APPROACH TO MONITORING PROBLEMS
The approach taken by the Work Group in reviewing monitoring
issues involved several distinct phases. (1) First, priorities
were assigned to the data needs of control and abatement programs,
(2) Then, a hypothetical monitoring system was devised which would
efficiently produce the data required. In this exercise, an effort
was made to determine the best balance of ambient monitoring,
source data collection, and modeling. (3) Next, SAMWG attempted
to identify problems and deficiencies of existing monitoring sys-
tems in meeting data requirements. (4) Finally, recommendations on
immediate corrective actions and several long-term directions were
made for consideration by officials responsible for monitoring
systems design and management. Throughout the Work Group's deli-
berations, the need to maximize potential benefits from existing
limited resources was of paramount concern.
Activities of a Basic Monitoring Program
In connection with the second phase of the approach just
described, the Work Group developed a basic outline of the elements
of an adequate air monitoring program. These were used as major
points of discussion in writing the issue papers discussed below.
Monitoring Program Activities
• Ambient Monitoring
State and Local Ambient Monitoring Stations (SLAMS)
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21
National Air Quality Trend Station (NAQTS)
Special Project Monitoring (SPM)
Diffusion Modeling
" Source Monitoring
Emission Inventories
Continuous Source Emission Monitoring
Manual Source Testing
Source Operation Parameter Monitoring
These basic activities are treated in some detail in the
succeeding portions of this document.
SAMWG Issue Papers
Because of the scientific and technical nature of air
monitoring, the Work Group believed critical reviews and evaluations
of such monitoring programs would be best conducted through dis-
cussions covering one pollutant or special topic at a time. Impor-
tant but strictly technical details such as instrumentation and
chemistry were not dealt with in any depth by SAMWG. Rather,
basic operational and program parameters were emphasized. As a
result, SAMWG developed a series of issue papers on general con-
siderations of air monitoring. A complete list of the issue papers
developed is provided below. Copies of these are available in
final form from SAMWG.
• Tape Sampler Monitoring Networks
• Background And General Considerations In The Develop-
ment Of Strategy Issues For Improvement In Air Moni-
toring
• Strategies For Improved S02 Monitoring
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• Strategies For Improved Oxidant And Hydrocarbon
Monitoring
• Strategies For Improved Suspended Participate Moni-
toring
• Strategies For Point Source Monitoring
* Strategy For Improved N02 Monitoring
* Strategies For Improved CO Monitoring
• Strategy Issues For Non-Criteria Pollutant Monitoring
The importance of producing timely data that are complete,
precise, accurate and comparable was well recognized by SAMWG. As
a result, implementation of quality assurance programs was stressed,
and reference to minimum quality assurance requirements was repeated
and emphasized in each appropriate issue paper.
ISSUE PAPER RECOMMENDATIONS AND AIR MONITORING STRATEGY DOCUMENT
All of the issues discussed by SAMWG in the various issue
papers generated one or more recommendations for improvement. (A
summary of these issues and the respective recommendations is given
in Appendix B.) The major recommendations and conclusions of the
issue papers form the substance of the overall air monitoring
strategy proposed in the present document.
The Work Group's major objective was to develop an air moni-
toring strategy that would provide the greatest possible benefit
from the resources devoted to air monitoring programs. It was
assumed that these resources would remain essentially constant.
Therefore, control agency efforts to implement the document's
recommendations may in some cases require a redirection of agency
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monitoring activities. To do this effectively, the relative
importance of various data needs will have to be carefully estab-
lished.
A summary of the major recommendations of SAMWG may be found
at the end of each chapter. They place major emphasis on the need
for greater flexibility at the State level in order to respond to
varied special purpose monitoring needs deriving from the general
goal of attaining and maintaining ambient air quality standards.
Several recommendations involve fixed, rigid requirements such as
adherence to the Federal Reference Methods and the establishment
of permanent National Air Quality Trend Stations.
Chapters III-VII of the present document discuss in detail
the individual elements of the air monitoring strategy, while
Chapters VIII and IX deal with its impact and implementation.
USE OF STRATEGY DOCUMENT
As mentioned earlier, the views and comments of State and local
control agencies were incorporated in the final version of the issue
papers and in the proposed strategy document. SAMWG promoted a further
interchange of views by holding a series of workshops on the proposed
strategy in January 1977. The final air monitoring strategy document
reflects the deliberations of these workshops as well as any additional
comments that were received on the proposed strategy document.
The final strategy document should be used to provide a blueprint
for the development of comprehensive air monitoring program plans.
SAMWG supports the idea that each State should develop a comprehensive
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monitoring plan which describes the major elements of the program
as well as a target schedule for implementation. Such plans should
be developed during the early part of FY 1978. It is recognized
that resource availability varies considerably from State to State
and consequently schedules for implementation will necessarily
differ from State to State.
Over the next five years, the Strategy Document will be used
as the overall basis for the Annual Program Guidance prepared by
EPA. It is SAMWG's intent that the' program guidance be used to high-
light the monitoring objectives to be stressed for the fiscal year.
This Annual Guidance will have to incorporate any changes in national
monitoring priorities and reflect the States' monitoring progress
and the comprehensive plans and schedules developed by the States.
To assist the States in implementing their plans, EPA in cooperation
with the States and local agencies will develop appropriate technical
assistance and guidance documents called for in the strategy document.
Another additional and important use of the air monitoring
strategy document is to provide the basis for proposing and promul-
gating changes in the Agency's regulations governing SIP reports
(40 CFR 51.7) and air quality surveillance systems (40 CFR 51.17).
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CHAPTER III
AMBIENT AIR MONITORING PROGRAM
INTRODUCTION
In the regulations (40 CFR Part 51) EPA wrote to guide the
preparation of acceptable State Implementation Plans (SIP's), the
Agency specified that the States would develop and operate an
ambient air monitoring program as an integral part of their effort
to attain and maintain the national ambient air quality standards
(NAAQS). The size of the States' ambient monitoring networks was
related to the pollutant priority classification and total popula-
tion of an air quality control region. In addition, the regula-
tions (40 CFR 51.17) required that the area of maximum pollutant
concentration be monitored.
As of this date, most States have developed networks that are
at least as large as the minimum size specified by EPA. In fact,
most states have developed and operate networks that somewhat
exceed the prescribed minimum. In cases where States notified
EPA of their intention to operate larger networks than required
by the regulations, EPA approved such networks as part of the SIP's
and continues to support the "additional monitoring" through the
grants mechanism. Thus, many approved networks that are larger
than legally required are partially maintained by Federal funds.
By and large, the networks that are operated by the States
provide the bulk of the information needed by the States and EPA
to evaluate the progress being made in the effort to attain and
maintain the NAAQS. EPA prepares reports and evaluations on the
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26
basis of these data to support the development of plan revisions
where needed, and to provide national overviews of the status of
air quality. The regions provide day-to-day assessment of the
adequacy of State monitoring systems to meet their need to evalu-
ate specific SIP's and to develop any air quality attainment/main-
tenance plans that may be needed.
It is recognized that the needs for, and uses of, ambient
data are dynamic. Accordingly, SAMWG's review of the ambient moni-
toring program focused first on the needs for ambient data (see
Chapter II). These needs were then compared with current and pro-
jected capabilities to determine if any serious deficiencies were
apparent.
This review showed that the ambient program is basically
effective in providing information for support of State implementa-
tion plan activities. Nevertheless, SAMWG identified several areas
where the correction of existing deficiencies would result in a
more efficient use of ambient monitoring resources at all levels.
The deficiencies were discussed in great detail in each of the
issue papers dealing with criteria pollutant monitoring. The
principal ones are summarized below to provide a perspective for
the program changes which should be implemented over the next five
years.
Redundant/Unneeded Data
In some cases, more stations are in operation than are
absolutely necessary for the purpose of documenting general ambi-
ent conditions and trends. In some areas, especially those where
ambient levels are well within acceptable limits, stations could
be terminated or relocated to other areas where ambient problems
are more acute. At the EPA headquarters level, routine overviews
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27
of national air quality and trends can be adequately evaluated
with data from a relatively small subset of stations routinely
operated by State and local air pollution control agencies.
Monitoring Inflexibility
Existing regulations do not allow State and local agen-
cies sufficient flexibility in conducting monitoring to meet cur-
rent data needs related to SIP review and revisions. In many
instances, resources needed to conduct special purpose monitoring
studies in support of SIP's are "tied up" in operation of monitors
which, although required by regulation, now provide only marginally
useful information.
Timeliness and Completeness of Data
The diversity of data needs, coupled with overall monitoring
resource constraints, has often resulted in information which is
untimely or incomplete in terms of its intended purpose. This
problem is most acute at the national level, where adequate air
quality data are often not available for routine trend analysis
until 12-18 months after each calendar quarter.
Data Quality
A host of factors related to monitor location and probe
siting, sampling methodology, quality assurance practices, and
data handling procedures have resulted in data of unknown or ques-
tionable quality. Many of these deficiencies will be minimized
over the next five years as a formal quality assurance program is
adopted and fully implemented by the State and local air pollution
control agencies.
FUTURE AMBIENT PROGRAM
SAMWG proposes the elimination of these deficiencies through
a careful process of planned improvements in SIP ambient monitor-
ing. As a first step, the existing SIP ambient networks should
be thoroughly reviewed by States and regional offices to determine
if these networks are capable of supplying the information neces-
sary to support SIP activities. The review should take into con-
sideration the design of the network (number and locations of
stations), instrument siting (exposure, distances from locally
interfering sources), and the operating characteristics of the
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28
monitors (equipment types, quality control, performance audits,
etc.). During the review process, deficiencies should be docu-
mented. Also, attention should be focused on determining ways in
which monitoring resources might be more efficiently used, such as
by relocation of monitors or shutdown of stations not providing
useful data, etc.
Second, a comprehensive plan should be developed by the States
in coordination with the regional offices for upgrading the SIP
ambient network. The plan, at a minimum, should provide for three
specific ambient monitoring activities. These activities should
come to be regarded as the principal types of ambient monitoring
conducted by State and local agencies and necessary to fulfill the
need for ambient monitoring information at the local, State,
regional and national levels. These activities are:
State and Local Air Monitoring Stations (SLAMS)
A carefully planned network of fixed monitoring stations
whose size and distribution is largely determined by the needs of
Regional Offices, States and local air pollution control agencies
in meeting their respective SIP requirements.
National Air Quality Trend Stations (NAQTS)
A small but well-defined core of fixed monitoring sta-
tions to minimally meet national needs for trend and SIP evalua-
tions. Initially, these stations will be essentially a subset of
existing SIP monitoring networks.
Special Purpose Monitoring
These monitoring activities shall consist of well-defined
studies required by the State and local agencies to support SIP's
and other air program activities.
The following sections discuss each of the proposed monitor-
ing activities in greater detail.
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STATE AND LOCAL AMBIENT MONITORING STATIONS
These stations will be the backbone of the ambient monitoring
program relative to SIP activities. They provide local agencies,
State agencies, and EPA with long-term air quality data on a routine
basis to ensure compliance with NAAQS, to measure air quality trends,
to indicate potential ambient problems, to measure background air quali-
ty, and to determine transport of air pollutants—all of which remain
essential elements in evaluating the effectiveness of the SIP's.
The majority of SLAMS should be located in problem areas to
ensure compliance with NAAQS throughout a State with a few sites
located to evaluate regional trends, particularly in potential
growth areas. Depending on the pollutant, additional background
air quality data sites may be needed to determine either remote
rural pollution levels or transport of specific pollutants into a
region. Data generated by these stations must be sufficient to
support ongoing local, State, regional, and national programs.
The following are examples of continuing programs which require
long-term air quality data and which should be considered by both
the regional offices and the States in planning and establishing
SLAMS networks. If possible, the data should be usable by more than
one program. Each of these programs have elements unique to a parti-
cular regional office or air pollution control agency and thus the
size and nature of the SLAMS networks will vary from area to area.
Suggested monitoring objectives relative to abatement and control
programs are:
Evaluation of Potential Non-Attainment Areas
Sites should be located in maximum pollution areas with
reasonable population exposure. While not every area with the
potential for violating NAAQS must be monitored, certainly the
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30
areas with the highest potential should be monitored, including those
areas in proximity to major sources of total suspended particulate
(TSP) and sulfur dioxide (S02).
Maintenance Plans
Long-term data needs for this activity would be associ-
ated with areas of rapid growth or changing emission patterns.
There may also be a need to develop long-term data showing trans-
port of a specific pollutant into a region. Once maintenance plans
are adopted, data will be needed to assess the effectiveness of the
control strategies.
Oxidant and Carbon Monoxide Control Strategies
Data needs will primarily involve a determination of the
effectiveness of control strategies and the need for additional
control measures. Long-term data needs may also involve residen-
tial, neighborhood and regional impact and trends.
Non-Deterioration Areas
There may be data needs in relatively clean areas which
are expected to experience significant growth. Future considera-
tions may require data from areas in economic decline to assess
the possibility of introducing new growth. Periodic monitoring
appropriate to the situation is recommended.
Emergency Episodes
Data will be required in areas which have significant
emissions and are prone to air stagnations.
Evaluate Existing SIP Control Strategies
Data will be required to evaluate the effectiveness of
existing control strategies, so that they may be retained,
tightened, or relaxed on a sound basis.
The entire SLAMS network should be reviewed annually and if
necessary, revised. Each site should be re-evaluated to determine
if it is still providing useful long-term air quality data for
current programs. Unneccessary stations should be eliminated or
relocated. The review shall include quality assurance procedures,
methodology, equipment, instrument siting and data handling. Modi-
fications to SIP SLAMS must not be made without the concurrence of
the EPA regional office.
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This network must meet specific requirements to insure quality
data.
1. Each site must meet approved EPA siting guidelines for
instrument exposure and sample inlet design.
2. Written quality assurance procedures must be developed
for each pollutant based on EPA guidance. (See chapter on quality
assurance.)
3. All sampling methods and equipment must meet the require-
ments of 40 CFR, Parts 50 and 53 (e.g., non-FRM and non-equivalent
instruments cannot be used after February 1980).
4. Acceptable data validation and record-keeping procedures
must be followed.
The number of SLAMS making up an adequate ambient network
cannot be realistically specified according to any set of national
criteria. In most cases, however, it is likely that several times
as many SLAMS as NAQTS will be needed to adequately represent the
air quality of any particular area. The actual size of SLAMS net-
works must be carefully evaluated and negotiated between the
affected agency and the EPA regional office. Existing guidance,
coupled with the combined experience of the monitoring agencies
are required to plan and implement necessary changes in existing
SIP monitoring networks. In some situations, this may be accomplished
through minor adjustments to the existing networks; in other situa-
tions, a major revision may be called for.
The monitoring data obtained from SLAMS should be stored at
the regional and/or State level. In cases where regional offices
elect to store/acquire data in a machine readable form, SAROAD
formats must be used. Regions are asked to encourage States and
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local agencies to use AQDHS for storage and retrieval of air
quality data in cases where its use is practicable. In some situ-
ations, regional offices may wish to make use of national ambient
data processing systems. These decisions should be matters for
EPA regional offices to negotiate with the State and local agencies.
On occasion, EPA headquarters will have special needs for
detailed SLAMS data. In these circumstances, requests will be made
through the appropriate regional offices, with allowance made for
such limiting factors as data availability, format and retrieval
capability. EPA headquarters will also require a tabulation of
SLAMS, to be updated on an annual basis. This will consist of
basic information related to station location, pollutants moni-
tored, etc.
SAMWG believes that a goal of the regional offices should
be the publication of an annual report summarizing SLAMS air
quality data. The report should contain a tabulation of pertinent
air quality statistics for each State. Existing publications pro-
vide a convenient reference point for further planning among
Regions regarding report format, style, and consistency. The
regional offices should initiate planning in FY-1978 for the pub-
lication of such reports. The target dates for beginning publi-
cation of these reports will vary from region to region according
to the capabilities and resources of the data collecting agencies
and regional offices. Further guidance on this will be given in
FY-78.
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33
SLAMS Recommendations
• EPA and State and local air pollution control agen-
cies should work together to establish a carefully
planned network of SLAMS whose size and distribution
will be largely determined by the SIP needs of the State
and local agencies and the regional offices.
• EPA regional offices should negotiate with State and
local air pollution control agencies regarding the for-
mat, frequency, and timeliness of data required from
SLAMS. Regional offices storing SLAMS data in machine
readable form must use SAROAD formats. EPA headquarters
requests for SLAMS data must be made through the approp-
riate regional office.
• EPA should require an up-to-date listing of all SLAMS
as well as other pertinent information (location, pollu-
tants monitored, measurement techniques utilized, siting
descriptions, etc.). States should report such informa-
tion to EPA on an annual basis.
• EPA should consider some form of technical assistance
to State/local agencies with their own data handling
systems to assure adequate compliance with data submit-
tal requirements.
• Regional offices should initiate plans in FY-78 to
prepare an annual summary report of air quality from
SLAMS on a state-by-state basis. Additional guidance
regarding contents, format, and alternatives for data
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34
handling related to implementation of such a report
will be issued in FY-78.
NATIONAL AIR QUALITY TREND STATIONS
National Air Quality Trend Stations (NAQTS) will consist
essentially of a subset of the SLAM's network with emphasis being
given to urban and multi-source areas. A few new stations may
need to be established in some areas in order to meet NAQTS
criteria. NAQTS, like SLAMS, must eventually conform to EPA
siting criteria and operate according to quality assurance pro-
cedures that equal or exceed EPA's minimum specifications. The
information provided from NAQTS will be used to answer a variety
of questions related to the effectiveness of the national control
effort. For example:
• Is air quality generally improving throughout the
country?
• Are these improvements roughly consistent with emis-
sion trends?
• Are the improvements different among various sectors
of the country?
• What areas of the country are experiencing broad-scale
air quality deteriorations? Why?
• Are certain seasons more pronounced in terms of air
quality trends or levels? Why?
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35
It is recognized that NAQTS data can only be used as a rough guide
to what may be actually happening in any particular urban area.
A comprehensive evaluation of air quality within a specific urban
area requires air quality information from a fully established SLAMS
monitoring network. Such evaluations would ordinarily be performed
on a routine basis by State and local agencies or by EPA regional
offices, using data from State and local air monitoring stations
in addition to NAQTS.
The purpose of officially sanctioning NAQTS is to remedy cer-
tain problems in the collection, analysis, and reporting of national
air quality data. These problems have limited EPA's ability to
report national air quality progress and modify national control
policies for the criteria pollutants. It is envisioned that the
network of NAQTS will result in the following improvements in the
current monitoring system.
Reduce the Quantity of Data Reported to EPA Headquarters
At the national level, the number of air monitoring
stations required to collect and routinely submit information
to EPA headquarters will decrease substantially. For TSP, the
number of stations required for national overview purposes will
decrease from approximately 4000 stations to approximately 1000,
a decrease of over 75 percent. Similarly, for SO? and N02» the
number of monitors will decrease from 2500 and 1000 to approxi-
mately 400 and 150, respectively. For CO and oxidants, the number
of NAQTS necessary are approximately 150 and 200. This represents
nearly a 65 percent reduction in the number of stations now sub-
mitting data to EPA's national data banks. Overall, the strategy
will result in a significant reduction in the number of observa-
tions routinely reported to the EPA national program.
Correct Site Information Deficiencies
Lack of specific knowledge about monitoring sites has ham-
pered the ability of national users to evaluate air quality trends
and patterns. Under the proposed system, each NAQTS will be
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36
extensively described in terms of orientation and distance from
major sources, data quality, type of monitoring equipment, and
other environmental factors relating to the exposure of the site
and how well it represents the surrounding area.
Provide for More Complete and Timely Data
Agencies responsible for the NAQTS will ultimately be
expected to submit complete, accurate, and timely data for analysis
and reporting. This will occur primarily because (1) these sites
will be well identified--!ate data would trigger inquiry and
followup--and (2) a high priority will be given to resource and
management commitments for their operation and the collection and
transmission of their data. Validated NAQTS data will be submitted
to EPA headquarters and available to national data bank users within
105 days after the end of each calendar quarter.
Substantially Enhance Data Quality
Monitoring at NAQTS must eventually be standardized and
rigidly controlled. Monitors will be EPA reference or equivalent
instruments and will be operated under quality assurance proce-
dures equal to or more stringent than those which EPA sets as the
minimum. As a result, data from this core of stations will be of
uniformly* high quality, consistent with the best state-of-the-
art field monitoring practices. Continuous monitors are preferred
for pollutants other than TSP. Note: The legal schedule for
replacement of non-reference or non-equivalent monitors is gov-
erned by the "grandfather clause" (40 CFR 51.17a) whereby non-
equivalent instruments must be replaced before February 1980.
General Criteria for NAQTS
The basic criteria**for selecting candidate areas for
NAQTS are urban population and pollutant concentration levels.
The Bureau of the Census has defined a total of 248 urbanized
areas in the country which have a combined urban population of
119 million people. Urbanized areas are defined by the Census
* Data collecting agencies are urged to develop procedures for
assessing the quality of ambient data obtained from NAQTS (see
quality assurance chapter).
**Further considerations in the design and siting of NAQTS are
discussed in Appendix C.
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37
as those having (1) a central city of at least 50,000 Inhabitants,
or (2) twin cities with contiguous boundaries which essentially
form one community whose population exceeds 50,000. Generally,
one or more of these urban areas are contained in a Standard
Metropolitan Statistical Area (SMSA). Since pollutant-producing
activities tend to be concentrated in urban areas, their popula-
tion is a more realistic indicator of the need for monitoring
than SMSA or AQCR population. Generally, a larger number of NAQTS
are desirable in more polluted urban and multi-source areas. The
number of NAQTS which will be located in specific areas will be
based on population and historical concentration data.
Obviously, these criteria are not fully adequate for deter-
mining the precise number of NAQTS to be established in any
particular area. The specific number of NAQTS and precisely
where they are to be ultimately established, must be a joint
decision among appropriate representatives of the affected agen-
cies, the regional office, and EPA headquarters. Priorities for
designation of NAQTS will obviously be determined by the (1) need
for information in a specific area, (2) the degree to which a
candidate monitor meets EPA siting criteria, (3) the type of
monitoring equipment at the candidate site (continuous or manual;
equivalent or non-equivalent) and (4) the timeframe and resources
necessary to establish a station in full conformance with the
intent and purpose of NAQTS. ,
In order to meet national objectives, a dual purpose moni-
toring approach is being proposed. The two purposes are to
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38
document (1) peak concentrations—long and short-term—and (2)
concentrations in densely populated areas. This dual approach
will provide information about the "worst" air quality in an urban-
ized area (that which the SIP's are designed to control) and also
provide additional information regarding population exposure.
SAMWG believes that both types of monitoring data are necessary
to provide a balanced national overview of air quality trends and
patterns of pollutant exposure.
In most instances, NAQTS should be sited* to reflect a neigh-
borhood scale of representativeness. Measurements in the neighbor-
hood scale represent conditions throughout some reasonably homo-
ge: jus urban sub-region with dimensions on the order of one to
vo kilometers. Homogeneity refers to concentration but could
apply to land use as well. The exception to the need for monitor-
ing at the neighborhood scale occurs with carbon monoxide (CO), for
which measurement on a smaller* scale (middle scale) is needed in
nder to characterize the impact of locally generated emissions
accomulatinq near heavily traveled streets in downtown or com-
mercial areas and near major roadways.
The NAQTS TSP stations, in addition to providing basic infor-
mation about the national and regional trends of TSP, will also
be used as a source of information for non-criteria pollutants
(e.g., trace metals, sulfates, and nitrates). This will be
accomplished by having the State and local agencies forward
*See Appendix C
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39
selected hi-volume filters for analysis and storage in EPA's
filter bank.
In urban areas where NAQTS are designated, several NAQTS TSP
monitors should be identified from which filters will be submitted
to EPA headquarters. As a guide, a minimum of two such monitors
should be selected in urbanized areas where population exceeds
250,000 and at least one monitor should be selected in urbanized
areas where population exceeds 100,000. Existing NASN stations
which are adequately sited are prime candidates since historical
non-criteria pollutant data exist from these sites for long-term
trend analysis. Not all filters from each of these two TSP stations
need be submitted. Assuming a sampling schedule of once in six days,
one-half the filters, or filters collected every twelfth day (approxi-
mately thirty filters per year per site), will be sent to EPA within
thirty days of the end of the quarter. The analytical data will
b6 returned to the States and local agencies within seven months.
In situations where the collecting agency chooses to retain all of
the NAQTS filters, the agency may operate a second monitor on a
twelve-day schedule at the same location and satisfy EPA's require-
ments by submitting these filters.
NAQTS will not be established to evaluate the impact of specific
point sources. This evaluation requires data from a moderate-sized
network for each isolated source. If we consider the number of
sources of potential concern, it is obvious that setting up ANQTS
for them would prohibitively increase the number of national trend
stations reporting data to EPA. EPA's strategy for assessing point
source ambient impact is based on a combination of source monitoring
and special purpose monitoring.
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As previously indicated, NAQTS data must be stored in EPA's
central data banks. To meet EPA headquarters needs, the goal is
to have NAQTS data accessible to national users from the national
data bank within 105 days after the end of each calendar quarter.
Since data handling capabilities vary considerably among the
States and local agencies and among the regional offices, no single
data handling scheme can be used by all. For example, it may prove
feasible to have some agencies forward NAQTS data directly to EPA
headquarters. In other cases, State and local agencies may require
regional office assistance in preparing and screening NAQTS data
before final submission to EPA headquarters. The regional offices
should develop a plan which is mutually agreeable with EPA head-
quarters and the affected State or local agency which contains
detailed schedules and procedures for handling and transmitting
NAQTS data. At a minimum, the plan should outline the responsibili-
ties of each organizational component in terms of data coding,
editing, screening and checking, formating, etc. To meet the
schedule called for above, the plan should ensure that accurate data
are provided to EPA headquarters in SAROAD format within 90 days
after each calendar quarter.
NAQTS Recommendations
• EPA and State and local agencies should work together
to establish a small but well-defined core of NAQTS capable of
minimally meeting national meeds for development of national con-
trol programs and policies, and evaluation of SIP's.
• Regional offices, with assistance from EPA headquarters,
must negotiate a data handling plan with those State and local agencies
responsible for collecting and submitting NAQTS data. The plan must
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41
contain a schedule whereby edited and valid NAQTS data are available
to national data bank users within 105 days after the end of each
data collection period (calendar quarter).
SPECIAL PURPOSE MONITORING
Special Purpose Monitoring (SPM) is defined as all ambient
monitoring performed apart from the SLAMS and NAQTS networks. It
is more flexible than these two networks; thus, it can be adjusted
easily to accommodate changing priorities. SAMWG recognizes that
the monitoring resources will not increase dramatically at any level.
Therefore, SAMWG recommends that SPM be used to supplement the fixed
monitoring network to make the overall effort more effective, avail-
able resources considered.
The SPM should have predetermined goals which provide useful
data for a specific program activity. In addition, SPM should be
given the same priority as the activity which it supports. The
conduct of SPM must not jeopardize the production of timely fixed
station data of high quality. On the contrary, SPM should enhance
the usefulness of fixed station data (1) by increasing the coverage
of that network with additional monitors for varying lengths of
time, (2) by checking the validity and representativeness of the
fixed network, and also (3) by producing data where none has been
collected previously or where existing data are no longer valid.
A list of various program activities and uses which may require
special purpose monitoring activities follows. Note that in some
cases this monitoring could include the measurement of non-criteria
pollutants at one or more of the SLAM stations if needed by the
supporting agency.
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42
• Determining air quality levels in areas suspected to be
higher than air quality standards but not monitored under the
SIP network.
• Developing and evaluating control strategies
•Determining nonurban background levels adjacent to metro-
politan areas
• Validation of Dispersion models
• Determining the impact of large point sources on ambient
air quality
• Quality assurance validity checks
• Characterizing significant air quality gradients
• Determining population-at-risk exposure
• SIP policy studies (fugitive dust, transport, etc.)
• Monitoring of non-criteria pollutants of special interest
to State or local agencies.
For obvious reasons of compatibility and comparativeness,
ideal SPM studies should be conducted with EPA reference or equiva-
lent methods, under the same quality assurance program as the fixed
network, and with proper use of applicable EPA siting guidelines.
Exceptions may occur when a particular goal of the studies warrants
the specific use of a non-reference/equivalent method or perhaps
variable sampling frequency. The sacrifice of data comparability
must be due to a special need of higher priority.
Special purpose monitoring activites are generally non-
recurring and of unique character in terms of pollutants monitored
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locations, frequency of sampling and other parameters of interest.
For this reason, it is not practical for EPA (regions, or headquarters)
to store such data in a central data file. Information relating to
both SLAMS and SPM would be of interest to a number of agencies
involved in monitoring, provided such information could be obtained
easily from a central location.
Therefore, information on SPM studies conducted by Federal,
State, and local organizations should be stored in a clearinghouse
for use by other agencies engaged in monitoring activities.
Special Purpose Monitoring Recommendations
• EPA and State and local air pollution control agencies
should work together to establish a plan for special
purpose monitoring (SPM) tailored to augment data from
SLAMS and NAQTS.
• A cost and technical feasibility study should be ini-
tiated by EPA headquarters to establish procedures for
setting up a clearinghouse for maintaining records and
answering requests concerning the availability and
location of special purpose air pollution monitoring data.
METEOROLOGICAL DATA TO SUPPORT AMBIENT MONITORING ACTIVITIES
The types and quantities of meteorological data that should
be collected depend on factors such as the uses and analyses
intended for the air quality data, the availability of representa-
tive meteorological data already being obtained by the National
Weather Service and control agencies, the complexity of the
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meteorological/topographical situations, and the cost and difficulty
of obtaining the data.
Uses of the SLAMS, NAQTS, and SPM network data have been
discussed in the previous sections. Most of these uses will require
meteorological data in accomplishing needed air quality assessments
and in control policy formulation. The analyses performed may
include adjustment of trends for meteorological differences
between comparable time periods, normalizing of air quality data by
comparing air quality measured in periods with similar meteorologi-
cal conditions, developing and testing air quality simulation models
to extend the information derived from monitoring stations both in
time and space, and determining meteorological parameters needed to
support programs to selectively control source emissions over certain
geographical areas or seasonal periods. Various examples of these
types of analysis can be cited from recent in-house and contractor
studies.
The National Weather Service, through its numerous field
stations, and also control agencies or their consultants, currently
obtain meteorological data that would be adequate in many instances
to fulfill the need for data of this type. Some of the data col-
lected by the National Weather Service, such as upper air data,
which is used in deriving transport and stability parameters, could
not be easily or economically collected by control agencies. The
National Weather Service through the facilities of NOAA's National
Climatic Center at Asheville, N.C., has facilities and capabilities
for storing and making available much of the needed data at a nomi-
nal cost. Hence, the need for additional meteorological data involves
only those areas where existing meteorological data are insufficient
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or unrepresentative of local conditions. This need may arise from
local peculiarities in emission sources (i.e., source height,
shape, building downwash, etc.), meteorology (i.e., sea/lake breeze,
urban heat island, etc.) or topography (i.e., hills, valleys, etc.).
It would be preferable to install meteorological sensors at
SLAMS and NAQTS; however, this would in many cases result in dupli-
cation of data collection.. SAMWG recommends that the National
Weather Service meteorological data be used to the extent possible.
If National Weather Service data are not available, it may be prac-
ticable to install a central meteorological station at one of the
NAQTS sites which is representative of several nearby NAQTS.
The meteorological data collected as part of fixed networks
should be stored with the air quality data. The National Aerometric
Data Bank provides meteorological data storage and retrieval capa-
bilities for the NAQTS. This capability should also be provided in
the system where the SLAMS data are stored. To facilitate data
analysis, some meteorological tabulation and analysis programs
should also be built into the systems, such as frequency distribu-
tions, wind roses, pollution roses, etc. These programs could be
expanded or refined as required for purposes of SIP data analysis.
Meteorological Recommendations
• Insofar as possible, the National Weather Service
meteorological data should be used in the interpretation
of SLAMS, NAQTS, or SPM data. In some cases, special
purpose meteorological data collection activites will be
required to support the need to establish the impact of
specific sources, determine pollutant transports, etc.
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• The regional offices should review available meteoro-
logical information to determine its adequacy in repre-
senting meteorological conditions at or near NAQTS.
• NAQTS where existing meteorological data are not repre-
sentative should be identified by the end of FY-78.
•Plans for collecting meteorological data in areas where data
are inadequate should be implemented by the end of FY-1980.
SUMMARY OF RECOMMENDATIONS
The following is a summary of the major recommendations related
to the future ambient monitoring program.
• State and local air pollution control agencies and EPA
should evaluate their respective monitoring programs annually
and modify them accordingly to meet the changing needs for
monitoring information.
• EPA and State and local air pollution control agencies
should work together to plan for and establish an ambient
monitoring program which contains, as a minimum, the following:
(a) A carefully planned network of State and Local Air
Monitoring Stations (SLAMS) whose size and distribution
will be determined largely by the needs of State and local
air pollution control agencies abatement and control programs;
(b) A small but well-defined core of National Air
Quality Trend Stations (NAQTS) which minimally meets
national needs for trend and SIP evaluations; and
(c) The conduct of Special Purpose Monitoring (SPM)
tailored to augment data from SLAMS and NAQTS.
• EPA should take steps to modify existing monitoring regula-
tions (40 CFR 51.17) to accommodate the need for SLAMS and
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47
NAQTS, and to incrase the flexibility required by State and
local agencies to conduct special purpose monitoring activities.
Similarly, reporting regulations (40 CFR 51.7) should be
modified to reflect the diminished need for large quantities
of data at the national level.
• Data gathered from NAQTS should be received in EPA head-
quarters within 90 days of the end of a calendar quarter.
EPA regional offices should negotiate with State and local
air pollution control agencies regarding the format, frequency,
and timeliness of data required from SLAMS and on an optimum
handling procedure for NAQTS data. Regional offices storing
SLAMS data in machine readable form must use SAROAD formats.
EPA headquarters requests for SLAMS data must be made through
the appropriate regional office. An inventory of SLAMS must
be provided to EPA on an annual basis. EPA should consider
some form of technical assistance to State/local agencies
with their own data handling systems to assure adequate per-
formance of data submittal requirements. Regions should initiate
plans in FY-78 for annual publication of reports containing
summary statistics of SLAMS air quality.
• A cost and technical feasibility study should be initiated
by EPA headquarters with a view to setting up a clearinghouse
for maintaining records and answering requests concerning the
availability and location of air pollution data from signifi-
cant special purpose monitoring studies.
• Insofar as possible, National Weather Service meteorological
data should be used in the interpretation of air quality data
gathered by SLAMS, NAQTS, or SPM studies.
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CHAPTER IV
SOURCE MONITORING PROGRAM
INTRODUCTION
Source monitoring encompasses both area and point source moni-
toring activities. There currently are approximately 165,000 point
sources and 3300 area (county) sources whose data are contained in
the central EPA data bank. Point source monitoring (PSM) can be
further broken down into two general categories, point source ambient
monitoring and point source emissions monitoring.
Source monitoring activities are conducted or required by EPA
and State/local control agencies to develop data and information in
support of enforcement decisions and to implement and evaluate air
programs policies and regulations. The addition of new program
responsibilities including New Source Review (NSR) and Prevention
of Significant Deterioration (PSD) and Energy Supply and Environ-
mental Coordination Act (ESECA) regulations, as well as continuing
program requirements such as evaluation and revision of State Imple-
mentation Plans (SIPs) indicate that program reliance on source moni-
toring data will increase in the future. Source monitoring should,
therefore, be viewed as a discrete monitoring program entity with
unique data gathering, handling, and reporting characteristics.
Atmospheric diffusion modeling, simulation modeling, greatly
depends on source monitoring data as well as emission, meteorological,
and topographic data in order to calculate the expected distribution
of air pollutants from a source over an area. The continually increas-
ing use of atmospheric dispersion modeling makes it imperative that source
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49
monitoring programs develop in a consistent manner.
Source/emission inventories are an integral component of source
monitoring, and are utilized primarily in air quality management
decisions. The inventories are of prime importance in the develop-
ment of air pollution control strategies and are required for
input to atmospheric dispersion models.
BACKGROUND INFORMATION ON POINT SOURCE MONITORING (PSM) DATA
The term "point source monitoring" is used here to designate
activities which are conducted to (1) establish the contribution
of an individual source to local air quality, (2) document con-
tinuing compliance with emission limiting regulations, by defining
that source's emissions and its environmental impact, or (3) pro-
vide a general picture of the relative contributions of source
categories and engineering information for large scale areas. PSM
may consist of a variety of activities which can be generally placed
in either of two categories, namely, emission and ambient monitoring.
Point Source Emission Monitoring
Point source emission monitoring (PSEM) may include the
conduct of actual source tests, the collection and evaluation of
continuous emission monitoring data obtained at the source, or the
collection and analysis of specific source process data (including
malfunction and upset information) which can provide an estimate
of emissions from the source. Specifically, PSEM encompasses one
or more of the following types of emission monitoring and data
collection activities: (1) continuous source emission monitoring,
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(2) manual source testing using reference methodology, (3) source
process monitoring, e.g., fuel analysis for combustion sources
(moisture, BTU, sulfur, ash, etc.), (4) malfunction and upset
reporting, (5) source inventory data collection (for emission
inventories), and (6) simulation modeling.
Point Source Ambient Monitoring
The ambient monitoring aspects of PSM are more limited in
scope than those associated with general trend monitoring. The
activity which is neither general source monitoring nor general
ambient monitoring, is referred to as point source ambient monitor-
ing (PSAM). It should be based on a consideration of such matters
as appropriate selection of the number and location of ambient air
monitors in the vicinity of the point source by use of appropriate
models, coordination of data collection with emission monitoring
activities conducted in the same study, collection and evaluation
of the ambient air quality data produced in the study, and finally,
coordination of meteorological data with monitoring data. An
important difference between PSAM and general trend monitoring
is that the former tends to be done on a case-by-case basis to
satisfy a particular air pollution control and abatement require-
ment, with the responsibility and cost for conducting the PSAM
frequently, though not always, borne by the source.
POINT SOURCE MONITORING USES AND REQUIREMENTS
The principal uses of PSM data in air quality planning, attain-
ment/maintenance strategy development, standards setting, and enforce-
ment action decision making are as follows:
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• Development of emission requirements for major sources
when making SIP revisions
• Determination of compliance status of sources for
specific enforcement actions
* Verification of the adequacy of control strategies and
associated SIP regulations to meet NAAQS
* Certification of fuel conversions under provisions of
the Energy Supply and Environmental Coordination Act
* Development of more representative emission factors
* Development and validation of long and short-term air
quality modeling procedures
* Conduct of new source review programs and implementation
of strategies for the prevention of significant deteriora-
tion (PSD)
• Evaluation of unique citizen complaint problems.
In the immediate future PSM will likely be limited to certain
emissions sources having significant impact on air quality or
sources specifically identified for analysis for enforcement pur-
poses. Approximately 21,000 such significant emissions point
sources have been identified. Of these, the 2400 sources listed
on the following page are most important as potential candidates for
point source monitoring activities for enforcement purposes (excluding
general emissions estimating requirements). PSM will principally
involve sources of sulfur oxides and total suspended particulate
matter, and, to a lesser extent, nitrogen oxides; emission inven-
tory requirements include all criteria pollutants.
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Source Category
Coal Fired Power Plants
Oil Fired Power Plants
Iron and Steel Mills and
Coke Plants
Non-ferrous Smelters
Refineries (petroleum)
Kraft Pulp Mills
Municipal Incinerators
Portland Cement
Phosphate Fertilizer
Sulfuric Acid Plants
No. of
Facilities
394
288
250
25
295
232
165
192
261
261
2363
Pollutants
TSP, SO. N0v
A A
TSP, SOY, N0¥
A A
TSP, SOX
TSP, S0x
SO, HC, TSP, CO
A
TSP, S02
TSP
TSP
TSP
S0x
It has been suggested that all significant point sources should
be routinely required to conduct PSM activities in the vicinity of
their facilities in order that information on air quality impact
of that source be available as the need arises. Section 114 of
the Clean Air Act, as amended, authorizes the Administrator of EPA
to require the owner or operator of any emission source to
"...(A) establish and maintain such records, (B) make
such reports, (C) install, use and maintain such monitoring
equipment or methods, (C) sample such emissions (in
accordance with such methods, at such locations, at such
intervals, and in such manner as the Administrator shall
prescribe), and (D) provide such other information, as he
may reasonably require;"
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This broad authority, according to section 114 (a), may be used
for the purpose of developing (and reviewing) SIPs, for determining
whether a source is in violation of any SIP or standard, and; for
carrying out the emergency episode and energy authority of the Act.
For these purposes, EPA may clearly place the burden for conduct and
cost of any or all reasonable point source monitoring activities
on the source management. Most states have comparable authority or
can be delegated the Administrator's authority under §114 (b) (1)
of the Act. However, in certain cases, the regulatory agency may
choose to exercise full control over the cost and operation of a
PSM activity. Where the conduct of PSM is performed by the source,
the responsible control agency should review and concur in the source-
proposed PSM program. Under SCS policy, certain sources are required
to conduct PSM activities as part of their compliance plan, along
with the other aspects of the SCS. The advantage of this approach
is that the data will be available quickly. This is an important
factor since violations can seldom be documented after the fact.
The disadvantage is the substantial cost of such monitoring where,
apart from SCS requirements, there is no well-defined prior need.
Also a significant amount of the data collected will never be used,
either because no need ever arises or the actual need is only for
a short-term study, as is usually the case.
On the other hand, certain PSM requirements of limited scope,
such as source process monitoring, may be advantageous to enforce-
ment programs. For example, mandatory submission of fuel analysis
data by power plants (utility and industrial boilers) could become
a permanent part of control agency compliance monitoring activities.
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Thus, sulfur content in fuel data could be used as an indicator of
continuing compliance with sulfur oxide emission limitations when
combined with other information about the source. The frequency of
data submission could be dependent on the quality and variability
of a coal or oil supply. For other categories of sources, process
feed material analyses or flow rates may serve an analogous purpose.
In addition, there will develop a need for substantial amounts
of point source monitoring in the near future as EPA and State/local
control agencies attempt to further define significant pollutant
contributor sources in non-attainment problem areas in order to
establish more stringent emission limitations. In addition, certi-
fication for fuel conversions by combustion sources under ESECA
will require PSM data in some cases. Other programs where the con-
duct of PSM activities by individual sources will be required in-
clude new source review procedures where source siting is evaluated
under prevention of significant deterioration guidelines, determina-
tion of compliance status for enforcement purposes, and development
of regulations. A critical requirement in these studies is a
definition of baseline air quality in specific areas where PSM
activities will be conducted.
POINT SOURCE AMBIENT MONITORING DATA
Currently, raw data generated by point source ambient net-
works are not normally submitted to EPA. This should continue to
be the case given the overall goal to decrease the amount of report-
ing to EPA. This philosophy is particularly applicable to PSAM
data since it need be reported only to the user, i.e., State or
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55
local agency or, when applicable, the appropriate EPA region.
These data are normally collected for a specified, relatively
limited period in the range of two months to two years, and have
meaning primarily to the user who must make a decision based on the
data, for example, to establish a new emission limitation for a SIP.
The raw data has no routine value on a national level but may be
needed for special studies and other purposes, such as diffusion
model validation, evaluation of new monitoring techniques, guidance
on establishment of new PSM systems, historical trends in local air
quality, etc. For these reasons, a national clearinghouse containing
an inventory of past PSAM activities, will need to be established
by EPA. The national clearinghouse would supply information con-
cerning the purpose for which the individual PSAM work was conducted,
exact location of data, scope of data collected, duration of the
study, source location, etc.
Recommendations
* It is recommended that raw data from PSAM activities
not be submitted to EPA on a routine basis.
• It is recommended that a national clearinghouse be
established to collect and store pertinent ambient monitor-
ing information related to each PSAM activity conducted in
order to centralize and facilitate dissemination of infor-
mation concerning PSAM activities. A suitable component
within EPA should be delegated the responsibility of
establishing a PSAM national clearinghouse, develop inven-
tory forms to be used by control agencies initiating PSAM
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work, provide for management facilities for the national
clearinghouse and establish procedures for reporting, col-
lection, storage and dissemination of PSAM information.
This inventory should be made widely available to regional
offices, State, and local agencies.
• It is recommended that point sources not be required to
routinely establish permanent full-scale PSAM programs to
continually assess environmental input due to the high cost
of permanent full-scale networks to the source and, more
importantly, to the control agency in collection, analysis,
and evaluation of data. However, this should be an option
of the State or local agency and the regional office.
Another consideration is a lack of well-defined need for
routine PSAM data; however, EPA should examine the advan-
tages of certain more limited PSM requirements such as
submission of fuel analysis data by power generation sources
and process feed data by other categories of sources as a
compliance monitoring tool.
POINT SOURCE EMISSION MONITORING DATA
As indicated earlier, point source emission monitoring consists
of continuous source emission monitoring, manual source testing
using reference methodology, source process monitoring, malfunction
and upset reporting, and source inventory data collection.
Continuous In-Stack Emission Monitoring Data
Continuous in-stack emission monitoring is now required for
certain categories of both new and existing sources, 40 F.R. 46240,
October 6, 1975. The categories of sources and pollutants
regulated are given in Table IV-1, both for new sources under new
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Source Performance Standards (NSPS) and existing sources under SIP.
The purpose of continuous emission monitoring is to provide a con-
tinuous record of emissions after the initial performance test in
order to ensure that the facility at all times employs proper oper-
ation and maintenance procedures to minimize emissions and maintain
compliance. Under NSPS, the source must keep a record of continuous
emissions monitoring data for a period of two years and submit to
EPA or the appropriate delegated State a quarterly report on excess
emissions occurring during the reporting period. Under the SIP's,
States must establish similar continuous emission monitoring require-
ments. Currently, requirements have been established as indicated
in Table IV-1. As can be .seen from the list, the requirements are
relatively complete for major sources of sulfur dioxide and nitrogen
oxides. However, there are major gaps for monitoring opacity.
Information from continuous emission monitoring is, of
course, a useful component of all PSM systems, since data on emis-
sions is available for the same time frame as ambient air quality
data. Useful data correlations, however, could be made at present
only for sulfur oxides and nitrogen oxides. Correlations for
particulate emissions are not possible at present because continuous
monitors measure emissions opacity.
Source Testing Data
Manual source testing is mandated for sources subject to
NSPS within 180 days after initial startup under 40 CFR part 60.
It is also mandated for certain sources subject to National Emission
Standards for Hazardous Air Pollutants (NESHAPS) under 40 CFR part
61. However, no periodic source test is now required by EPA either
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TABLE IV-1
CONTINUOUS EMISSION MONITORING
Source Category
fossil fuel fired
steam genrators
sulfuric acid
nitric acid
catalyst regenerators
for fluid bed cat-
alytic cracking units
electric arc
furnaces
primary copper,
zinc and lead
smelters
ferroalloy
production
facilities
Pollutants
opacity
S00
NO.
or
SO,
NO,
opacity
opacity
opacity
so2
opacity
New
>250 million
Btu/hr
all sources
covered by
NSPS
all sources
covered by
NSPS
all sources
covered by
NSPS
all sources
covered by
NSPS
all sources
covered by
NSPS
all sources
covered by
NSPS
Existing
>250 million Btu/hr
S02 only if flue gas
desulfurization
NO only where control
strategy required
02/C02 only if state
has emission
regulations
>300 ton/day
production
>300 ton/day
production and
only where control
strategy required
>20,000 BBl/day
no requirements
no requirements
no requirements
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for new or existing sources. It has been EPA's practice to require
source testing by way of §114 authority when compliance status is
in doubt and at the completion of a compliance program set forth
under an administrative order or consent agreement. Most State
and local control agencies operate similarly, i.e., a high degree
of flexibility is maintained concerning requirements for source
testing. It is essentially a case-by-case decision and should
remain so whether the source test provides data for an enforcement
decision or standard setting purpose or as part of a broader PSM
program. Whenever manual source testing is conducted every effort
should be made to acquire simultaneous continuous monitor data
where appropriate (i.e., where the source is subject to continuous
monitoring regulations). This will be useful in (a) verifying
that the source's continuous monitor is operating properly, (b)
providing a quantitative basis for subsequent determinations of
emission compliance, and (c) enhancing the probability that the
source will keep the continuous monitor in proper operation and
maintenance.
Source Process Monitoring Data
An additional aspect of emission monitoring is the valuable
information provided by fuel analysis data in fuel consuming sources,
and feed analysis data in certain chemical process sources. Such
data may provide pertinent information concerning source emissions
which can be an important part of PSM.
Recommendations
* It is recommended that continuous emission monitoring
requirements continue to be set for all major sources and
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pollutants. Consideration should also be given to require-
ments for monitoring and reporting of process feed data
such as fuel sulfur content or other relevant parameters
which can provide an indication of a source's compliance
status.
* It is recommended that high priority should be given by
EPA to the development and improvement of continuous moni-
toring instruments for all major categories of sources and
all regulated pollutants. It is specifically recommended
that continuous monitoring instruments or other techniques
be developed to monitor particulate emissions from indus-
trial sources or alternately, to convert opacity measurements
made by existing continuous monitors into particulate emis-
sion rates. EPA should also continue efforts to develop
remote source and long path monitoring techniques to be
used as adjuncts to PSM systems.
* It is recommended that EPA continue to establish QA pro-
cedures and techniques for validating the accuracy of data
produced by source continuous monitors.
* It is not recommended that raw data from continuous
monitors employed by industry in compliance with emission
monitoring regulations be routinely reported to control agencies,
Quarterly excess emission reports along with program man-
dated source inspections by the appropriate control agency
provide an adequate system to enforce proper operation and
maintenance at the source.
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• It is recommended that EPA develop a system with a
uniform format for use by State/local agencies to handle
information from excess emission reports in order to mini-
mize the source reporting burden and the control agency
data analysis burden.
* It is recommended that manual source testing should
continue to be a case-by-case decision to be made by the
responsible control official whether it is to be required
solely or as part of a more comprehensive PSM system.
AIR QUALITY SIMULATION MODELING
An air quality simulation model is a numerical method, based on
physical principles, for estimating pollutant concentrations in
space and time as a function of emission rates, meteorological
conditions and terrain factors. A competent analyst, using an
appropriate model and adequate and representative data can provide
information which suggests how available resources may be allocated
to produce the greatest improvement in air quality.
Air quality models can provide information on the location and
magnitude of the maximum concentrations; the distribution of con-
centrations in relation to the distribution of population; the
emission reductions needed to meet ambient air quality standards and
significant deterioration increments; the effects of installation of
control devices, process changes, the selection of sites for facil-
ities, and the relocation of sources of pollutants; the interim
suspension of major polluting activities; and tomorrow's or next
year's air quality.
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A fixed ambient air monitoring network provides data at a dis-
crete number of locations. The outputs of a model can provide
important data on the distribution of air quality concentrations
between widely spaced ambient monitors. They can indicate the
existence of "hot-spots" that otherwise may go undetected. The
costs incurred may be a small fraction of costs of monitoring.
However, for most relevant applications of models some minimum
amount of monitored ambient air quality and emission data are
essential. These data enable the performance of the model to be
tested. The analyst can coincidentally evaluate monitoring and
modeling data to identify background air quality data under a
variety of meteorological circumstances. He can make appropriate
adjustments to the model input data and identify the strengths and
weaknesses of the numerical method used for the particular problem
at hand. Finally, statements on the validity of the model appli-
cation can be made with greater confidence, and the air pollution
control official can use the data to assess more properly the con-
sequences of his decisions.
Air quality simulation models are slowly improving. More
definitive emission and ambient air quality data are providing
better bases to judge the applicability of the models with more
widespread use, the advantages and limitations of models are better
understood. Greater emphasis is being placed on more standard or
uniform application of the models; nevertheless, the diversity of
the Nation's terrain, climate and configuration of the several
thousands of sources of pollution dictates against a "cookbook" -
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only approach. EPA currently has an ongoing program to develop a
consensus of the scientific and air pollution control communities
on the selection and application of air quality models for air
pollution control purposes. Professional judgment in the selection
and application of models will retain an essential role in air
quality management.
Recommendation
It is recommended that the use of dispersion models be
fostered as a cost-effective technique to assess ambient
air quality and the impact of point sources on the environ-
ment. EPA should encourage more standard, although probably
not uniform, applications of models for particular pollutant
species and pollution problems. EPA should issue an
authoritative statement or guideline which has undergone
comprehensive outside peer-review on this matter.
SOURCE/EMISSION INVENTORY
The source/emission inventory provides the most basic tool for
air pollution control planning and management because it defines
the probable causes of the air pollution problem. The inventory
provides information concerning source emissions and defines the
location, magnitude, and relative contribution of these emissions.
It can be used to measure the effect of control activites and to
indicate future problems. The emission inventory is used to pre-
dict ambient air quality, and, in conjunction with a permit or
registration system, to provide up-to-date information on major
sources of pollution. In addition, the emission inventory is a
valuable guide in designing and evaluating air monitoring networks.
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Emission inventory information, by defining the major source
contributors (motor vehicle, industrial, etc.), influences national
control programs.
The level of detail put into the compilation of an emission
inventory depends to a great extent on the predominant use of such
data and also on the user of the emission inventory data. At the
national level, data from emission inventories is submitted to the
National Air Data Bank (NADB), National Emissions Data Systern.(NEDS)
and is required for a variety of purposes. Included among the many
uses are the following:
National Uses of Emission Inventory Data
• As an aid in the initial development of national strate-
gies.
• EPA review and evaluation of proposed SIP control strate-
gies.
• Identification and determination of relationships between
specific emission sources or source categories and ambient
air quality.
• As a mechanism to identify and locate sources that are
out of compliance or that should have compliance schedules
(interface with CDS).
• Preparation of national emission trends (EPA and CEQ).
• As a data base to be used to develop and improve general
emission inventory procedures.
• As a mechanism to evaluate the need for and determine the
priorities for development of new or improved emission
factors.
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• As a data base for use in development of alternative
strategies for automobile emission controls.
• As a mechanism to provide data for projecting emissions
and future air quality.
• As a data base for use in preparation of various Environ-
mental Impact Studies so that the impact of a proposed new
source is considered in context of sources and problems
already in existence.
• As a data base for use in cost./benefit studies.
• To assess the national impact of specific types of sources
with their current degree of control versus projected
future controls.
• As a data base to assist in determining priorities for
*
new research programs and new source performance standards.
Federal Regulations - Source/Emissions Reporting
Current Federal regulations pertaining to source emissions
reporting (40 CFR 51.7b) require State agencies to semiannually
submit data for selected point sources in the standard NEDS format.
The National Emissions Data System is a computerized data
handling system which accepts, stores, and reports on information
relating to sources of any of the five criteria pollutants (parti -
culates, SOV, NOV, CO, and hydrocarbons). NEDS was created to
f\ /\
provide a centralized source/emissions data bank for which
standard input forms would be used and output reports could
be generated to meet the requirements of the majority of users
of source/emissions data. In NEDS, a major distinction
is made between two types of sources: point sources and area
sources. Point sources, in the broadest sense, are stationary
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sources large enough to be identified and tracked individually;
although, per NEDS reporting requirements, they are any plants
emitting more than 100 tons/year of any of the criteria pollu-
tants. Area sources, on the other hand, are those stationary and
mobile sources which individually emit much less than 100 tons/
year and are too small and too numerous to keep individual records
on. In NEDS, area sources are considered collectively on a county
basis. It is the responsibility of the States (as required by
Federal regulations) to update the point source data semiannually.
Area source data, because of their composite nature, are generally
maintained centrally by NADB, although state-supplied data will be
accepted in place of nationally derived estimates.
In its deliberations, SAMWG thoroughly discussed the
existing regulations in light of the national uses of the collected
emissions inventory data. The result of the Work Group's delibera-
tions was an attempt to reduce the amount of data reported to
EPA and the frequency of reporting. With this goal in mind, SAMWG
in its December 1976 draft of the strategy document, proposed
that the States submit a baseline inventory to EPA. This inven-
tory called for less detail than the current Federal regulations.
During the workshops held to discuss the strategy document, many
State and local participants pointed out that their agency's
emission inventory needs require a more detailed level of emission
inventory data than the items which would have comprised SAMWG's
proposed baseline inventory. Since the State and local agencies
have a continuing need for the more comprehensive inventory and the
baseline inventory would require a different reporting and com-
pilation format, preparation and submission of the baseline
inventory reports as proposed would have required the expenditure of
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additional resources. In light of this situation, it was concluded
that the more comprehensive emission inventory reporting require-
ments of the current regulations should be retained and an
emissions inventory task force should be formed to recommend
what specific items should be included in the comprehensive
inventory. The current suggestions of the Work Group is that
the emission inventory reported to EPA for each criteria pollutant
should be continued. The inventories should include sources that
have actual emissions of 100+ tons/year of each of the following:
suspended particulates, sulfur dioxide, nitrogen dioxide, hydro-
carbons, and carbon monoxide. As additional air quality standards
are promulgated, the emission reporting level for each pollutant
should also be specified. The strategy reviewers had no objections
to the SAMWG's recommendation to change emissions inventory
reporting from a semi-annual basis to an annual basis.
When diffusion modeling is to be used, a detailed inven-
tory including data such as the following, are required: UTM
coordinates, SCC codes for each process, stack data, (e.g.,
height, diameter, temperature of exhaust gases and flow rate), and
percent of fuels used for space heating and seasonal production
rates. The information needed for a detailed inventory is identical
to that required for a NEDS inventory except that the total county
area emissions would need to be apportioned by source category
on a grid basis. The detailed inventory fills all the needs of
annual dispersion models. For short-term models, diurnal source
information is necessary. Point source inventories have always
been collected by the responsible State or local agency. Area
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source (county) data in the main have, in the past, been compiled
and analyzed by EPA headquarters. However, the increasing impor-
tance of HC, CO, and NOV, all of which have area sources as a
X
significant contributor, indicates that State/local control
agencies, who have not collected such data should be placing an
increasing importance on the knowledge and availability of area
source emissions data.
Compliance Data System
For purposes of clarification, another inventory system
which is not covered under the Federal reporting regulations
40 CFR 51.7, should be briefly discussed.
This separate inventory system, the Compliance Data System
(CDS), was developed to assist the Environmental Protection Agency
in carrying out its enforcement and surveillance programs. It is
used to record information on identified major polluting facilities
to provide information about the compliance status of these
facilities; and to keep track of enforcement actions taken by
regulatory agencies against these facilities.
CDS provides users with an effective tool for managing
large quantities of non-parametric stationary source information
in an efficient and expeditious manner. The system can store,
update, and retrieve large quantities of data describing the com-
pliance status and the enforcement activites of all major and many
minor sources of stationary air pollution. In effect, CDS is an
automated tickler file which provides both historical and current
record keeping capabilities.
A great deal of information must be readily available to
those responsible for conducting a successful enforcement program
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for stationary sources of air pollution. CDS accomplishes the
following:
(1) It provides an inventory of those sources of pollution
which are affected by Federal, State, or local emission regula-
tions and a fast retrieval capability for details about them.
(2) It provides both milestone (summary) reports and
listings of facilities which are in compliance, out of compliance
and of unknown compliance status with State, local, and Federal
regulations.
(3) It tracks enforcement actions scheduled into the
future and also can provide an historical report of actions
scheduled or achieved in the past.
(4) It can be used to prepare special reports. With the
retireval capability, CDS can be used to prepare special reports
based on standard industrial class (SIC) codes, on New Source Per-
formance Standards, or on any other criteria based on user needs.
(5) It can be used to coordinate State and local enforce-
ment programs. In some States, enforcement and compliance infor-
mation can be fed directly from the State into CDS. In all States,
CDS can provide highly effective turnaround documents used by
States for providing the region with new or additional enforcement
information; and
(6) It can be used to anticipate future enforcement require-
ments. CDS has a great deal of built-in flexibility, and it is
being constantly upgraded to meet current and anticipated user
requirements.
CDS requires that data be maintained on sources that have
the potential for emitting at least 100 tons/year of a specific
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pollutant. Potential emissions instead of actual emissions were
adopted as the source criteria for a number of reasons:
(1) A data base was desired that did not fluctuate with
production, use, or governmental restriction. The data base would
remain relatively constant and would permit statistical and perfor-
mance evaluations.
(2) A need existed to monitor continually the performance
of sources even after control efforts had been realized. Sources
which have the potential to substantially impact air quality in
the event of a malfuction or because of poor maintenance should be
monitored for continued compliance on a routine schedule.
(3) The total number of potential 100 ton/year emission
sources nationwide represented a reasonable amount of sources for
Federal oversight, and their total emissions represented the bulk
of the pollution problem.
(4) 100 ton/year actual emission sources have a discernible
ambient air quality impact. Therefore, when they are controlled
to less than 100 ton/year, these must be monitored to assure attain-
ment even if controlled to 90 + %, since non-compliance through
malfunction, control deterioration, or other reasons would result in an air
quality impact. As an example, a source of 1000 ton/year actual
emissions which was 95% controlled would emit only 50 ton/year.
But if the control deteriorated to 80%, 200 ton/year of emissions
would result. If the cutoff were 100 ton/year actual, this source
would not be monitored.
It should be emphasized that the SAMWG recommendations
regarding source emission inventories only refer to the Federal
regulations (40 CFR 51.7) which cover the recording and submittal
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of reports which must follow the procedures and forms originally
tr
described in APTD-1135, Guide for Compiling a Comprehensive
Emission Inventory. The SAMWG recommendations do not at this
time address or affect the separate requirements of the Compliance
Data System (CDS).
Source/Emission Inventory Recommendations
• Comprehensive emission inventories should be upgraded
annually to include all new or modified sources and all
sources that have ceased operations during the year. Data
should be submitted to EPA, in the NEDS fixed format machine
readable form, within 180 days after the end of the calendar
year. Data may be submitted more frequently as they become
available. If a source's inventory has not changed, the year
of record should be updated. The inventories should include
criteria pollutant point sources actual emissions and area
sources for those areas where the NAAQS are either violated
or threatened. The point source inventories should include
sources that have actual emissions of: 100+ tons/year of
each of the following: suspended particulates, sulfur dioxide,
nitrogen dioxide, hydrocarbons, and carbon monoxide. As
additional air quality standards are promulgated, the emission
reporting level for each pollutant should also be specified.
t Detailed diurnal emission inventories necessary
for short-term (hourly, daily) dispersion modeling should be
collected by State and local agencies only as needed. Agencies
using diffusion models for development, evaluation, or revision
of a SIP should retain the inventory for a period of time as
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specified by the EPA regional office.
• Improved guidance for compiling emission inventories
should be developed by EPA. In order for this document to
reflect the needs of its intended users, a group comprised
of State and local and EPA representatives should be established
to recommend items to be included within each point and area
source data category to be reported.
SUMMARY OF RECOMMENDATIONS
• EPA program offices should assist RO's and State and
local agencies by defining PSM data needs for specific program
areas and also assist in the conduct of programs when PSM may
be required. This support may be in the form of technical
support documents to define under what program circumstances
PSM may be desirable. Generally, discretion and flexibility
to apply PSM requirements should rest with RO's or State and
local agencies except for requirements specifically regulated
such as continuous in-stack source emission monitoring.
• The burden of conducting and paying for point source
monitoring should be placed on the responsible source to the
extent possible. Factors such as cost of monitoring, sensitive
litigation, and special studies may mitigage this rule. This
decision should be made by the appropriate control agency
official on a case-by-case basis.
• Control agencies should provide an overview of PSM
programs developed by sources required to do so by virtue
of control agency requirements. Appropriate review and con-
currence of proposed PSM programs, with final acceptance being
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based on how effectively the proposed PSM will satisfy
pertinent program requirements, should be an integral part
of this oversight activity.
t Appropriate quality assurance (QA) procedures for conduct
of PSM activities should be established. Acceptance of source-
generated PSM data should be premised on use of standardized
QA procedures. EPA should provide appropriate technical
assistance to State and local agencies relating to QA procedures.
• Raw data from point source ambient monitoring activities
should not be submitted to EPA on a routine basis.
• It is recommended that a national clearinghouse be
established to collect and store pertinent ambient monitoring
information related to each PSAM activity conducted in order to centra-
lize and facilitate dissemination of information concerning these
activities. A suitable component within EPA should be delegated
the responsibility of establishing a PSAM national clearinghouse,
develop inventory forms to be used by control agencies initiating
such activities, provide for management facilities for the national
clearinghouse and establish procedures for reporting, collection,
storage and dissemination of PSAM information. This inventory
should be made widely available to regional offices, State,
and local agencies.
• Point sources should not be required to establish
permanent full-scale PSAM programs to continually assess
environmental impact due to the high cost of permanent full-scale
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networks to the source and, more importantly, to the control
agency for the collection, analysis and evaluation of data.
However, this should be an option of the State or local
agency and the regional office. Another consideration is
the lack of a well-defined need for routine PSAM data; however,
EPA should examine the advantages of certain more limited
PSM requirements such as submission of fuel analysis data by
power generation sources and process feed data by other
categories of sources as a compliance monitoring tool.
• Continuous emission monitoring requirements should
continue to be set for all major sources and pollutants.
• High priority should be given by EPA to the development
and improvement of continuous monitoring instruments for
all major categories of sources and all regulated pollutants.
• EPA should continue to establish QA procedures and
techniques for validating the accuracy of data produced by
source continuous monitors.
• Raw data from continuous monitors employed by industry
in compliance with emission monitoring regulations should not
be routinely reported to control agencies. Quarterly excess
emissions reports along with program mandated source inspections
by the appropriate control agency provide an adequate system to
enforce proper operation and maintenance at the source.
• EPA should develop a system with a uniform format
for use by State/local agnecies to handle information from
excess emission reports in order to minimize the source
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reporting burden and the control agency data anlaysis burden.
• Manual source testing should continue to be a case-
by-case decision to be made by the responsible control official
whether it is to be required solely or as part of a more
comprehensive PSM system.
• The use of dispersion models should be fostered as
a cost-effective technique to assess ambient air quality and
the impact of point sources on the environment. EPA should
issue guidelines to assist State and local agencies in the
application and calibration of validated models.
t Comprehensive emission inventories should be updated
annually by the appropriate control agency and submitted to
EPA. If the inventory for a source has not changed, the year
of record should be updated. The inventories should include
criteria pollutant point source actual emissions and area
sources for those areas where the NAAQS are either violated
or threatened. The point source inventories should include
sources that have actual emissions of: 100+ tons/year of
each of the following: suspended particulates, sulfur dioxide,
nitrogen dioxide, hydrocarbons and carbon monoxide. As
additional air quality standards are promulgated, the emission
reporting level for each pollutant should also be specified.
Data should be submitted to EPA, in the NEDS fixed format
machine readable form, within 180 days after the end of a
calendar year. Data may be submitted more frequently as they
become available.
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• Detailed emission inventories necessary for dispersion
modeling should be collected by State and local agencies only
as needed. Agencies using diffusion models for development,
evaluation, or revision of a SIP should retain the inventory for
a period of time as specified by the EPA regional office.
• Improved guidance for compiling emission inventories
should be developed by EPA. In order for this document to
reflect the needs of its intended users, a group comprised of
State and local and EPA representatives should be established
to recommend items to be included within each point and area
source data category to be reported.
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CHAPTER V
FUTURE MONITORING PROGRAM FOR NON-CRITERIA POLLUTANTS
INTRODUCTION
The categorization of air pollutants as criteria or non-cri-
teria pollutants comes from the provisions of the Clean Air Act of
1970. The Act requires that EPA establish air quality criteria and
national ambient air quality standards for pollutants which have an
adverse effect on public health and welfare and which have widely
distributed mobile or stationary sources. There are six "criteria"
pollutants regulated under this part of the Act. These are sulfur
dioxide, nitrogen dioxide, total suspended particulates, carbon
monoxide, non-methane hydrocarbons, and photochemical oxidants. In
April 1976, EPA proposed lead as a possible seventh criteria
pollutant.
Because of the extensive and explicit requirements of the Act
for criteria pollutants, all other pollutants have come to be known
collectively as non-criteria pollutants. This is a somewhat arti-
ficial category in that it contains a very large number of chemi-
cally heterogeneous pollutants whose single common attribute is that
they do not fall under sections 108, 109, or 110 of the Clean Air
Act.
In the past, the effectiveness of non-criteria pollutant moni-
toring by EPA and other agencies has suffered from a lack of coor-
dination of monitoring activities, the absence of centralized
direction over instrumentation and procedures and insufficient lead
time for developing new monitoring methods. Non-criteria
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pollutant monitoring has generally produced data of unknown precision
and accuracy. Moreover, data coming from various sources have been
difficult to compare. Responding to pressures to develop regulations
and standards, EPA has used whatever data could be assembled. This has
meant, in some cases, that the Agency has inadvertently become committed
to monitoring with methods which were chosen hastily since time did not
permit necessary development and comprehensive evaluation of methods, or
field trials of selected or alternative methods. In the past, EPA has
been reluctant to use non-criteria pollutant data developed by other
agencies, both Federal and non-Federal, and by private industry because
of a concern about the adequacy of quality assurance programs used in
gathering the data. Also EPA has not been able to provide adequate techni-
cal leadership to the monitoring community for the collection of non-criteria
pollutant data.
Included in the non-criteria category are pollutants which are regu-
lated only under Section 111 and 112 of the Clean Air Act. However, the
largest group of non-criteria pollutants of concern are the so-called
"toxic substances" which will probably become subject to regulation now
that the Toxic Substances Control Act has become law. A tentative list
of the principal non-criteria pollutants of concern is given in Table V-l.
The list is not final and is presented with the understanding that it
needs to be critically reviewed for the purpose of establishing priorities.
This review and establishment of priority should involve appropriate
elements of EPA and State and local air pollution control agencies. For
the purpose of this review by the Standing Air Monitoring Work Group,
non-criteria pollutants do not include airborne pesticides or radio-active
materials.
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A number of the organizations engaged in non-criteria pollutant
monitoring are presented in Table V-2. It is common for a number
of organizations to be interested simultaneously in the same non-
criteria pollutant, although each organization may have established
different monitoring objectives. Monitoring objectives range from
just demonstrating that a pollutant is present to making accurate
measurements of pollutant concentrations over a wide geographical
range and sampling over protracted time periods. This multiplicity
of pollutants, monitoring organizations, and monitoring objectives
has resulted in a wide variety of non-criteria pollutant monitoring
activities. Therefore, it is extremely important that EPA estab-
lish policies and implement a well-coordinated program to assure
that reliable non-criteria data are collected in a timely fashion
to meet Agency needs, and that monitoring data collected by dif-
ferent organizations and techniques are interrelatable. It is the
view of the Standing Air Monitoring Work Group that there are a
number of general areas in which steps can be taken to improve the
effectiveness of non-criteria pollutant monitoring activities and
these are discussed below.
BASELINE INVESTIGATIONS OF NON-CRITERIA POLLUTANTS
Elsewhere in this strategy document, there is a discussion of
the establishment of permanent trend sites for criteria pollutants.
It is the viewpoint of SAMWG that a continuing baseline program of
non-criteria pollutant monitoring should be conducted at these
permanent trend sites and other appropriate locations. This should
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Table V-l
Tentative List of Non-Criteria Pollutants*
Acrolein
Aeroallergens
Aldehydes
Ammonia
Ammonium bisulfate
Ammonium sulfate
Aniline
Asbestos
Arsenic
Barium
Benzene
Benzidine(s)
Benzo[a]pyrene
Beryllium
Bis-chloromethyl ether
Cadmium
Carbontetrachloride
Chlorinated benzenes
Chlorinated phenols
Chlorine
Chloroform
Chloroprene
Chromium
Cobalt
Copper
Ethylene
Ethylene dibromide
Ethylene dichloride
Ethylene oxide
Formaldehyde
Hydrogen sulfide
Hydrochloric acid
Iron
Lead
Manganese
Mercury
Methyl Iodide
Mycotoxins
a-Naphthylamine
Nickel
Nickel Carbonyl
Nitrate
Nitric Acid
Nitric Oxide
Nitrobenzene
Nitrosamines
Noble Metals
Numerous iminoheterocyclics
Numerous polycyclic aromatics
Organic lead
Organic sulfates
Peroxy acetylnitrate
Phenol
Phosgene
Polybrominated biphenyls
Polychlorinated biphenyls
Respirable particulates
Selenium
Sulfate
Sulfuric Acid
Styrene
Tetraethyl lead
Trichloroethylene
Tris-2,3-dibromopropyl phosphate
Vanadium
Vinyl Chloride
Vinylidene chloride
Zinc
* The order of presentation of pollutants in this table does not
reflect any prioritization by SAMWG.
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TABLE V-2
PRINCIPLE ORGANIZATIONS INVOLVED IN NON-
EPA Organization
Environmental Monitoring § Support Laboratory
Environmental Sciences Research Laboratory
Office of Air Quality, Planning § Standards
Strategies § Air Standards Division
Monitoring and Data Analysis Division
National Enforcement Investigations Center
Regional Offices, Surveillance § Analysis Divisions
Other Federal Agencies
State and Local Agencies
Other Organizations
Universities
Private firms
National Bureau of Standards
American Society for Testing and Materials (ASTM)
CRITERIA POLLUTANT MONITORING
Monitoring Function
Monitoring in support of air program objectives,
analysis and maintenance of NASN filter bank, develop-
ment and technical assistance to EPA Regional Offices.
Develop new methodology for measuring air pollutants,
carry out research in atmospheric chemistry and air
pollutant transport.
Monitoring data acquired to support standards and
regulatory decisions.
Analyses and data bank maintenance.
Monitoring to support requirements of OGC and other
EPA components.
Activities in planning, enforcement, and problem
evaluation.
Monitoring pursuant to requirements of NEPA or ESECA,
etc.
Activities in planning, enforcement, and problem
evaluation.
00
Research studies, contracts, and grants.
Required or self initiated studies for various
purposes for CAA, ESECA, etc.
Development of standard reference materials.
Development of standard procedures.
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be of the type that is presently conducted for NASN sites (the
participate matter collected is analyzed for components such as
benzo(a)pyrene, sulfates, nitrates, and trace metals).
The value of such a program is demonstrated by the present
effort to establish a standard for lead and the investigations into
the possible control of such compounds as benzo(a)pyrene and sulfates.
These efforts are strongly supported by information from the NASN
filter bank.
The objective of a baseline investigative effort is to collect
non-criteria pollutant samples from different geographical locations
with distinct atmospheric characteristics. A collection of such
samples provides a preliminary indication of the location of important
pollutant sources and sampling over a period of years provides additional
indications of trends in pollutant concentrations.
It should be emphasized that data from a baseline network cannot
be expected to provide comprehensive information about a non-criteria
pollutant and would not eliminate the need for more extensive and special
studies.
ANTICIPATORY MONITORING RESEARCH AND DEVELOPMENT
The importance of establishing a workable method for
initial data collection and the time required to complete method
development argue in favor of anticipatory research and develop-
ment on monitoring methods. Until EPA anticipates rather than
reacts to monitoring needs, a crisis atmosphere is bound to
prevail, and air pollutant data will continually be questioned.
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A complete program of method research and development should
include a survey of alternative measurement principles and instru-
mentation, method evaluation, comparative testing of candidate
methods, and field testing of the selected method. Research
and development for monitoring methods should be a balanced program
ranging from periodic surveys of what existing technologies
should be adopted for short-term operational monitoring to more
basic research on the development of new monitoring principles.
A pervasive difficulty with anticipatory research and
development is the large number of possible non-criteria air
pollutants and the uncertainty as to which non-criteria air
pollutants might be the subject of the next crisis. This un-
certainty cannot be completely resolved. However, steps can
be taken to lead anticipatory activities in a direction with a
high probability of payoff. SAMWG believes that responsibility
and sufficient resources should be assigned to a specific program
within EPA to conduct anticipatory monitoring research and method
development activities. It is essential that the activities be
closely coordinated with EPA's existing research, field monitoring,
and quality assurance activities to prevent any duplication of
effort or waste of resources. A second essential step is for EPA
to develop, with significant input from environmentally oriented
medical experts, a priority list of non-criteria pollutants for which
a monitoring method is likely to be needed. The basis for such a list
is a coordinated assessment of pollutant toxicity and prevalance in
the environment.
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The Work Group also suggests that EPA operate a small pilot
network of monitoring sites so that (1) the new measurement
methodology could be evaluated under closely controlled conditions.
(2) internal quality control procedures could be perfected,
(3) data manipulation techniques could be developed, and (4) ex-
ternal quality assurance requirements could be evaluated. The
pilot network stations could approximate field conditions and
be located in different urban atmospheres. Such a network would
provide perfected monitoring systems which could be made
available to the general air pollution monitoring community
with a high degree of assurance that the methods would work
satisfactorily.
It is also the observation of the Work Group that the
method development which has occurred has tended to be in the
area of ambient monitoring. In some cases, development activities
could be more profitably focused on source emissions monitoring
methods, which, in combination with mathematical modeling and
limited ambient monitoring, may give better estimates of air
quality than ambient air monitors alone. This approach appears
to be particularly valid for a pollutant emitted from a single
stack or a small number of sources. As in ambient monitoring,
field testing of source sampling methods should be a prerequisite
to EPA selection and endorsement of a source monitoring method.
EXCHANGE OF NON-CRITERIA POLLUTANT MONITORING INFORMATION
At the present time, organizations at the Federal, state,
and local levels of government and in the private sector are
engaged in non-criteria pollutant monitoring, but there appears
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to be little exchange of information concerning the monitoring
methods used and little circulation of the data obtained from the
various non-criteria pollutant investigations. In view of the
considerable experience and expertise which has been developed
outside of EPA, it is the opinion of SAMWG that EPA should establish
a central information point for collection and dissemination of
this information about non-criteria pollutant monitoring projects.
Increased involvement of non-Federal agencies could have
benefits: more comprehensive investigation, sharing of costs,
and a greater mutual understanding of the pollutant problem.
Some non-criteria pollutant problems could be addressed by State
or local action without Federal intervention. Also, the exchange
of information would facilitate standardization of monitoring
methods.
While the Work Group is in favor of greater cooperation
between Federal and non-Federal agencies in non-criteria pollutant
monitoring, the precise basis for such coordinated activity
should probably be determined by the specific case at hand. In
some cases, these activities should be mutually funded, and in
others it may be appropriate for EPA to underwrite the cost of
the cooperating agency's involvement. Generally, involvement
of State and local agencies should be through the EPA regional
offices.
FUNCTIONAL MANAGEMENT OF NON-CRITERIA POLLUTANT MONITORING
It is the recommendation of the Work Group that EPA should
establish a group with the authority and resources needed to
provide centralized direction of non-criteria pollutant monitoring.
It is essential that this be closely coordinated with EPA's
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quality assurance, methods standardization, and air monitoring
equivalency programs and with research activities. It should
be made clear that centralized direction would extend only to
how monitoring should be conducted. It would not determine such
particulars as when, how much, and by whom non-criteria monitoring
would be done. Specifically, direction of non-criteria pollutant
monitoring should include:
1. Recommendation of the best monitoring method available
for use by the Agency components that need to monitor for a
non-criteria pollutant.
2. Recommendation of quality assurance activities needed
for each measurement system.
3. Collection and dissemination of information about current
or previous monitoring efforts for non-criteria pollutants.
The benefits of such management would be substantial:
the quality of the data collected would be adequately documented;
the data would be interrelatable; the results of previous moni-
toring would be available to influence decisions concerning the
need for additional monitoring; and there would be a sound basis
for expert testimony in support of data collected by established
procedures and methods.
In a crisis situation, the centralization of non-criteria
functional management would afford a single point for making
decisions on the adequacy of existing methods and for initiating
development of a new method on an accelerated basis.
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IMPLEMENTATION
The Work Group observes that implementing the above recom-
mendations could lead to functions which overlap; therefore,
SAMWG suggests that all the recommended functions should be the
responsibility of a single group within EPA.
The activities of such a program would be divided between
continuing research and development .of monitoring methods aad
direct support of monitoring programs initiated by other organi-
zations. The preliminary job for the program would be to
establish a list of priority needs for routine and new monitoring
methods after appropriate consultation with other concerned EPA
organizations. This would be followed by the survey of available
methods for each pollutant on the list, and the preliminary.selec-
tion of a promising monitoring technique. The complete evaluation
of the method would be accomplished through comparative and
collaborative testing, and the establishment of performance,
data, and quality control systems. The Work Group envisions
that method development and improvement would be a continuing
process, with each selected method fully field tested in a
pilot network of stations situated in various urban atmospheres.
SUMMARY OF RECOMMENDATIONS
EPA should implement a program to assure that non-criteria
monitoring data collected by different organizations and
techniques are interrelatable.
EPA should continue its baseline program of non-criteria
pollutant monitoring by analyzing samples from the TSP NAQTS
network, and other appropriate locations on a routine basis.
EPA should publish this information annually.
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• EPA should set up a small pilot network of monitoring
sites where new measurement methodologies and quality
assurance techniques can be evaluated.
• EPA should establish a central information point for
the collection and dissemination of information on non-
criteria pollutant projects covering both ambient air
and source monitoring.
• State and local agencies are strongly encouraged to
coordinate their own non-criteria pollutant monitoring
with EPA's so that the best available methods and qual-
ity assurance techniques are used.
' In consultation with state and local agencies and
with appropriate medical experts, EPA should develop in
order of priority, a list of important non-criteria air
pollutants.
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CHAPTER VI
QUALITY ASSURANCE ACTIVITIES FOR AMBIENT
AND SOURCE MONITORING
INTRODUCTION
In order for air monitoring data to be useful, it must be of
acceptable quality. The dissemination and use of data of poor or
unknown quality can lead to confusion and possibly incorrect decisions
with regard to environmental standards and regulatory actions. The
gathering of air monitoring data under the umbrella of a quality assur-
rance program does much to avoid regulatory mistakes, and all control
agencies should vigorously pursue the implementation of such measures.
It is important to understand that these quality assurance programs
apply both to ambient air measurements and to measurements of emissions
from stationary sources. Both types of air monitoring data need to
be collected under the auspices of sound quality assurance programs
because both are used in making important decisions. Data of unknown
or suspect quality are not much better than no data at all.
The major elements of support needed by the air pollution moni-
toring community for a satisfactory quality assurance program are
(1) the availability of an evaluated measurement methodology which
is adequate for its intended purpose, (2) satisfactory performance
by organizations collecting the air pollution monitoring data,
(3) assessment of the performance of monitoring agency by an indepen-
dent outside agency, and (4) the availability of competent technical
assistance for organizations needing to improve their performance. It
is imperative that the monitoring program's management be committed to
a quality assurance program and that adequate resources be available
to carry on the activities involved in its major elements.
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To be sure, the implementation of a formal quality assurance program
does have its price, but the cost of collecting good air monitoring data
is far less than the cost of making incorrect regulatory decisions
because of poor data. Experience has shown that an agency should be
prepared to spend between 10 and 25 percent of its monitoring budget to
develop and implement the type of quality assurance program discussed below.
DEVELOPMENT AND IMPLEMENTATION OF AIR POLLUTION MEASUREMENT QUALITY
ASSURANCE PROGRAMS
Federal, State, and local agencies all have important roles to play
in developing and implementing satisfactory quality assurance programs.
EPA's responsibility is to develop the tools needed to carry on a quality
assurance program, and it is up to the State and local agencies to
implement the programs.
Role of EPA Headquarters
EPA Headquarters has the following responsibilities:
•To be certain that the methods and procedures used in
making air pollution measurements, both of ambient air quality and
stationary source emissions, are well evaluated and that their limits
of precision and accuracy are well understood. An important part of
this responsibility is the certification of existing air monitors as to
whether they conform to the requirements of 40 CFR 53 (equivalent and
reference methods).
• To determine the performance of laboratories making air
pollution measurements of importance to the regulatory process. The use
of external performance audits is emphasized in this part of the program.
• To implement satisfactory quality assurance programs
over EPA's air pollution monitoring, both ambient and source, which
have the potential for generating data used for setting standards.
• To be certain that air monitoring data of importance
to the regulatory process is of satisfactory quality.
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• To render technical assistance to the air pollution
monitoring community.
Role of the EPA Regional Offices
The major responsibility of EPA's regional offices is the
coordination of quality assurance matters between the various ele-
ments of EPA and the State and local agencies. This role requires
that the regional offices make available to the State and local
agencies the technical information and quality assurance programs
which EPA headquarters has developed and make known to EPA head-
quarters the unmet quality assurance needs of the State and local
agencies. Another very important function of the regional office
is the evaluation of the ability of State and local agency labora-
tories to measure air pollutants of regulatory concern. To be
effective in these roles, the regional offices should maintain and
strengthen their technical capabilities with respect to air pollu-
tion monitoring.
Role of State and Local Agencies
The major responsibility of State and local agencies is
the implementation of satisfactory quality assurance programs over
the monitoring which yields the air quality data needed for the
regulatory process. It is the responsibility of State and local
agencies to implement these programs in their own laboratories and
in any consulting and contractor laboratories which they may use to
obtain ambient and source emission data of importance to the regu-
latory process.
MINIMUM QUALITY ASSURANCE PROGRAMS
Comprehensive quality assurance programs in air monitoring are
relatively new, and many agencies responsible for air monitoring
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have not formalized their quality assurance activities into an iden-
tifiable program. As an aid to agencies who are developing quality
assurance programs, and agencies who wish to review existing programs,
we present here those activities we consider to be essential in an
air pollution monitoring quality assurance program. These essential
activities and other aspects of a complete quality assurance program
are described in detail in "Quality Assurance Handbook for Air
Pollution Measurement Systems - Volume I, Principles (EPA-600/9-76-005),
and this document should be consulted in establishing or evaluating
a quality assurance program.
A suggested sequence for the development of a quality assurance
program is given below. About 12 months is required for complete
implementation, and we suggest that agencies begin developing this
program no later than the beginning of FY-78 (October 1, 1977).
Develop Immediately
• Agency Quality Assurance Policy and Objective
Each State agency should develop a written quality assurance
policy consistent with national quality assurance policy. This should be made
known to all agency personnel and, as a minimum, should create an awareness
of quality assurance activities, provide specific procedures for implementing
a quality control program, provide for corrective action when required,
state quality assurance objectives for each major monitoring pro-
ject operated by the agency, and explicitly delegate authority to
implement quality assurance systems planned by management officials.
• Organization and Responsibilities
An organization chart showing the key agency person-
nel and their area of quality assurance responsibility should be
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prepared. A quality Assurance Coordinator should be designated for the
agency. This designee should be responsible* for the coordination of
quality assurance activities within the agency and with other agencies.
Develop Within Six Months
• Measurement Method Review and Application
All existing methods (sampling and analysis) used for
routine ambient air and source emission measurements should be
reviewed and revised if necessary; written procedures should be
prepared where none exist. A document control system should be
developed for these methods to keep agency personnel abreast of
changes in methodology. Any ambient air monitoring for criteria
pollutants conducted under State Implementation Plans must use EPA's
reference methods or EPA-approved equivalent methods or have plans and
schedules for meeting this requirement by no later than February 1980.
States that have received a delegation of authority to enforce the
Standards of Performance for New Stationary Sources and the National
Emission Standards for Hazardous Air Pollutants must use the EPA
reference methods or EPA-approved alternate or equivalent methods
when monitoring for these regulated pollutants.
• Calibration Procedure Review
Calibration procedures used for all measurement methods
should be reviewed, revised if necessary, documented, and included
in the method write-up just mentioned. Document control should also
be established for these calibration procedures to inform agency
personnel of any changes. As an agency policy, traceability of the
accuracy of working calibration standards should be established by
comparing these standards to standards of higher accuracy whenever
standards of higher accuracy are available.
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' Internal Quality Control Procedures
The procedures used during sampling and analysis to detect,
correct, and record out-of-control conditions should be defined and
documented. Use of control charts is encouraged.
' Audit Procedures
Procedures should be selected and implemented that will per-
mit comparison of the performance of the measurement system (sampling
and analysis) under routine operation versus an independent technique.
Commonly, this independent technique is either a performance audit or
the use of a dual measurement system. Results from these audit procedures
are useful in detecting bias in the routine measurement system.
• Interlaboratory Testing
Each agency and its contractors conducting monitoring acti-
vities should participate in the EPA quality assurance performance
surveys. Requests for participation should be made at the EPA Regional
Office.
Develop Within Twelve Months
' Data Validation Procedures
The criteria used to validate air monitoring data should be
documented and the routine tests or checks on the raw data should be
defined.
* Preventive Maintenance
By measurement method, a schedule for preventive maintenance
should be prepared that identifies the maintenance tasks and frequency
required. A history of items requiring maintenance or guidance from
instrument vendors are useful in developing this schedule. A procedure
for performing the maintenance task should be prepared if none is available.
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* Review of Training Needs
Proper training of staff members is essential for the per-
formance of their assigned job responsibility. During the first twelve
months, the training and experience of all staff, members should be re-
viewed and plans made to obtain needed training.
SUMMARY OF RECOMMENDATIONS
• Comprehensive quality assurance programs should be implemented
by October 1978 for those agencies not having such programs.
• Agencies currently implementing quality assurance programs should
continuously review and evaluate their existing programs.
• EPA Headquarters should continue and expand its program in
developing the technical basis for quality assurance programs.
• Regional Offices should maintain and strengthen their technical
capabilities with respect to air pollution monitoring.
• EPA should perform a survey to determine the number and age
of air monitoring instruments currently in use in State and local
agencies by measurement principle and pollutant. Based on the
survey results, a testing program should be implemented to determine
whether those instruments in most widespread use meet the perfor-
mance specifications and other applicable requirements of 40 CFR 53
(Reference and Equivalency Regulation). Testing results should be
made available to State and local agencies in sufficient time to
minimize any disruptions to their programs while complying with the
regulations requiring State and local agencies to use only reference
or equivalent instrumentation after February 1980.
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CHAPTER VII
ANALYSIS AND INTERPRETATION OF AIR QUALITY INFORMATION
The purpose of this chapter is to present two separate but
related themes involving the analysis, interpretation, and display
of air quality information. These themes may be simply stated as
follows: (1) the complexities of air quality management will
require a more sophisticated approach to data analysis and evalua-
tion than that which has been followed traditionally to support
abatement and control programs; further, (2) EPA and the State and
local agencies must devote additional effort to displaying and
publicly reporting timely and meaningful air quality information.
DATA ANALYSIS AND EVALUATION
The first of these themes may be illustrated by way of several
examples in which data analysis impinges directly on air program
abatement and control activities. These examples indicate a grow-
ing need for more thoughtful and competent analysis of air monitor-
ing data.
The first example comes from recent efforts by governmental
agencies and the private sector to clarify the relationship between
oxidants and precursor hydrocarbon and nitrogen oxide emissions.
In one such effort, Bell Laboratories used "robust" statistical
procedures to demonstrate the extent of oxidant transport through
the Northeast corridor from New York City to Boston, Massachusetts.
This analysis was based on data obtained from the ground station
network of oxidant monitors now operated by the States. Bell's
analysis demonstrated that highest oxidant peaks were associated
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with southwesterly air flows which transport precursor emissions
from high emission density areas of New York towards Connecticut
and Massachusetts. Preliminary EPA analyses of these data indi-
cate a possible difference between weekdays and weekends with
respect to the distance downwind where highest oxidant levels
occur. EPA is now conducting further analyses to determine if
the differences are statistically significant and to what extent
they can be explained in terms of the difference between emission
patterns prevailing on weekdays and weekends.
In a parallel effort, EPA is devoting considerable time and
effort to the analysis of ambient and chamber oxidant data. The
purpose of this effort is to provide better technical guidance to
the States for the development of oxidant control strategies.
This analysis combines the results of state-of-the-art photochemical
oxidant diffusion modeling and empirical analysis of ambient data
to derive a closer approximation of the process that is believed
to occur in the ambient air. Although this and many similar
efforts are in the nature of research, it is extremely likely
that similar efforts will be required by the States and local
agencies in the future to determine the most realistic and practi-
cal means of attaining the oxidant standard.
A second example of the increasing importance of data analysis
is to be found in the interpretation of peak concentrations in
relationship to short-term ambient standards. The conventional
approaches for describing pollutant concentration data in terms of
a single probability distribution function is not uniformly
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accepted nor applicable for all source pollutant configurations.
There appears to be a need for additional evaluation of air quality
data to develop guidance which addresses the adequacy of distri-
bution functions in estimating peak concentrations in cases where
intermittent sampling is being done. A uniform procedure for
estimating peak concentration is especially important for EPA's
regional offices and State and local agencies in revising SIP's,
reviewing variance requests, and in reviewing new sources. A pro-
cedure is also needed to develop statistical error bands on esti-
mates of peak concentration and for evaluating these uncertainties
in relationship to concentration variations caused by annual and
seasonal meteorological fluctuations.
A third example area where data analysis has an increasingly
important program application is the evaluation of air quality
trends. Trends are important indicators of the rate of improve-
ment of air quality, and provide a convenient check on the adequacy
of emission reductions to achieve the standards. Such evaluations
are complicated by annual and seasonal variations in meteorological
conditions which can lead to false impressions as to the relative
rate of progress or deterioration. Procedures to "account" for
meteorological influences are just being developed and must be
tested before their routine application in air quality trend anal-
ysis can begin. For some pollutants, notably oxidants, approxi-
mately 5 or more years of data at a single monitorinq site are appar-
rently necessary before any meaningful trend can be detected. Better
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techniques are necessary to sharpen the analysts' ability to detect
"subtle" impacts of gradual emission changes on oxidant air quality.
The last example area concerns the use of pollutant roses to
evaluate the impact of specific sources or source categories.
Although tabulation of data in the format of pollutant roses is a
relatively simple and straightforward task, the procedure is highly
effective for illustrating and quantifying the contribution of
source emissions on ground-level ambient concentrations. Pollutant
roses are also useful for evaluating trends, especially in situa-
tions where air quality at a particular monitoring site is dominated
by a local source.
These four examples are no more than a limited sample of the
kinds of anlaysis which should become an integral part of a total
air pollution control program. There are no reliable guides available
for determining the exact needs of the State and local agencies for data
analysis. The Work Group recommends that EPA establish such guidelines
and that they be used in determining the minimum level of resources
necessary for data analysis activity.
AIR QUALITY DISPLAY AND REPORTING
SAMWG observes that air quality monitoring information pre-
sented in a geoqraphical or spatial context is useful to air pollu-
tion agencies and highly informative for the public. Using such
an approach, in which pollutant concentration isopleths are shown
for a specific area, it is possible to emphasize a broader
geographical scale than that which is generally associated with a
single monitoring station. In this context, geographically
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oriented air quality presentations supplement conventional tabula-
tions of air quality summary statistics. Portrayal of air quality
in the form of concentration isopleths is an extremely effective
technique for providing:
. A "visual" perspective of the spatial and geographi-
cal variations in air quality and patterns of population
exposure;
• A meaningful reference for evaluating air quality
trends in relation to temporal and spatial emission
trends; and,
. A spatially representative baseline of air quality
for evaluating and modifying regulatory programs (e.g.,
SIP's, new source reviews, attainment decisions).
SAMWG recognizes that isopleth display techniques are not
new and, in fact, have been used in the past by EPA and some
State and local agencies. SAMWG is calling attention to these
techniques now to foster their increased use by air pollution
control agencies for pollutants for which these techniques are
most suitable.
Basically, there are two approaches to generating the
necessary air quality information: (1) using data from an exist-
ing network, and (2) using an air quality diffusion model.
The first approach requires data from a reasonably "dense"
air monitoring network. The adequacy of the network in terms of
its size or "density" is' largely determined by the known or sus-
pected air quality gradients. Areas in which air quality changes
slowly across the region of interest would require fewer stations.
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To clarify the concept, an example of the application of the tech-
nique is illustrated in Figures VII-1 and 2. The New York City
area was chosen to illustrate the technique since a rather large
TSP network has been in operation there for some time.
Figure VII-1 shows TSP isopleths based on spatial interpola-
tions of annual average concentrations obtained from the existing
air monitoring network in the New York City metropolitan area. In
this example, it is clear that highest annual average TSP concen-
trations are centered over the metropolitan core of New York City.
Obviously, in 1971 large portions of the area were subject to
annual averages in excess of the Federal ambient standard. It is
also clear from this figure that a significant improvement in air
quality occurred between 1971 and 1974. In this example, the
land area over which the standard was exceeded decreased from 19
percent in 1971 to approximately 4 percent in 1974. In addition,
the spatial distribution of population has been correlated with
the air quality isopleths to produce a comparison between the
population exposure distributions of 1971 and 1974.
This trend is illustrated in Figure VI1-2 in a population
exposure distribution to various annual TSP levels. Figure 2 shows
that 58 percent of the population in 1971 was living in areas
exceeding the primary annual TSP standard while, in contrast, by
1974 levels had decreased to the point that only 17 percent of the
population was exposed to annual concentrations in excess of the
annual TSP standard.
While this example analysis in New York City clearly illus-
trates the advantages in displaying air quality in this fashion,
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FIGURE VII-1
ISOPLETHS OF ANNUAL AVERAGE TSP CONCENTRATIONS FOR THE NEW
YORK, NEW JERSEY, CONNECTICUT AQCR IN 1971 AND 1974
AtlNUAl MfSN TOTAL
ENDED PARTICULATE CONCEN
TRATIQN EXCEEDS ANNUAL PRIMARY
STANDARD OF li wm'J
NEW YORK
o
ro
ARE AS WHERE ANNUAL ME AN TOTAL
SUSPENDED PARTICULATE CONCtl
TRATION EXCEEDS ANNUAL PRIMARY
STANDARD OF 14 uifm3
NOTE. ISOPLETH MAPS ARE BASED ON SPATIAL INTERPOLATION FROM DATA MEASURED
AT ioj MONITORING SITES. LOCAL TSP MAY VARY BECAUSE OF METEOROLOGY. TOPOG-
RAPHY. AND EMISSIONS.
iif annual vcometnc mean concentration:,
<-7 total stispencJi'J.paniculate in Wtl.
Isopieihs of annual geometric mean concentrations
of total .suspended paniculate in 1974.
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FIGURE VII-2
POPULATION EXPOSED TO ANNUAL TSP
(NY. NJ, CONN AQCR)
100
CC<
II
-,UJ
S
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there are limitations which restrict broad-scale national appli-
cations. The principal limitation is that there are only rela-
tively few areas in the country where a history of data from
"dense" monitoring networks is sufficient to allow accurate
isopleth profiles. This is particularly true for oxidants and
NO- since intensive monitoring for these two pollutants has been
non-existent until very recently. Currently, there are probably
no more than 2-4 urbanized areas with sufficient monitoring
information to develop ozone and N02 isopleths for two or more
years.
As indicated, another approach for obtaining the necessary
information is through the application of air quality diffusion
models in which pollutant concentrations are estimated for a dense
network of artificial receptors. The major disadvantage in using
models to estimate pollutant isopleths is that an emission inven-
tory is needed which generally requires extensive time and manpower
to generate. In addition, a minimum amount of air quality data
are necessary to validate or calibrate the model before it can be
used to predict areawide pollutant concentrations. This disadvan-
tage is largely compensated by several distinct advantages. One
advantage is that the modeling process tends to smooth out the
influences of local factors which have an undesirable local effect
on air quality measurements. For example, a monitor located so as
to reflect air quality which is affected disproportionately by a
small nearby source may bias the results to the point that they
may not represent an appropriate ambient scale in the vicinity of
the monitor. In such situations, model-generated isopleths are
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more representative of ambient air quality than those generated
from inappropriate monitoring stations. Another important advan-
tage in using a model to develop air quality isopleth displays
is that the model can be used to predict concentrations at any
geographical point in the area of concern. This is especially
important in areas where a limited number of monitors are in
operation.
Diffusion models which have been developed for TSP and SCL
are widely accepted for predicting pollutant concentrations under
most topographical and meteorological circumstances. At present,
no satisfactory models exist for routine use in predicting area-
wide concentrations of oxidants and N02, primarily because of the
enormous complexity of the task of accurately simulating the
chemical reactions of precursor pollutants emitted into a dynamic
and turbulent atmospheric environment. Current air quality models
for CO are reasonably adequate for simulating large-scale (1/2 to
2 km) ambient levels, but are not presently adequate to accurately
estimate CO concentrations occurring in confined areas of high
emission density such as in street canyons, near intersections,
and the like.
Future efforts on the part of the state and local agencies
to develop maintenance plans, review and modify SIP's, and conduct
new source reviews will require the use of diffusion models. Much
of the use of models in the future will be geared to long-range
air quality planning since air quality continues to respond to
emission reductions designed to attain NAAQS. Modeling to support
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the development of air quality maintenance plans will result in
isopleth displays of air quality for areas for which additional
controls must be evaluated. In this manner, model-generated is-
opleths enable a planner to project the areawide air quality effects
of new growth patterns. In particular, the significance of a
potential new source can be evaluated in terms of its likely air
quality impact.
SAMWG believes that in cases where modeling is required,
strong consideration should be given to the desirability of dis-
playing areawide air quality patterns and trends. In cases where
modeling activities are not planned, existing monitoring networks
should be evaluated to determine whether adequate concentration
isopleth displays can be appropriately developed.
SAMWG has established that a goal of the monitoring strategy
is the development of isopleth concentration displays for large metro-
politan areas, especially those having an urbanized population exceeding
1,000,000. The selection of areas should be determined by a number
of factors including (1) adequacy of the monitoring base; (2) the
nature of the pollutant problem (e.g., fugitive dust versus industrial);
(3) the resources available ; and (4) the practicability of using
diffusion models in cases where their use is necessary for an adequate
areawide air quality display. These air quality displays should be
developed and updated annually by State and local agencies using
either actual monitoring data, air quality diffusion models, or a
combination of both. For at least a defined subset of these areas,
isopleth displays should be estimated for an appropriate base year
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(e.g., 1970) to enable control agencies to portray trends in air
quality and population exposure.
The precise areas and schedules under which the State and
local agencies would accomplish this would be decided through joint
consultations between the States and regional offices during the
formal program planning process. SAMWG also recommends that EPA
develop a technical guideline document for use by the State and
local agencies in developing isopleth concentration displays. The
guideline should prescribe the procedures, estimation techniques,
and input information requirements which produce satisfactory
displays.
In addition to public-oriented presentations of air
quality data, SAMWG feels that the public should be kept informed
of day-to-day changes in air quality. EPA's Pollutant Standards
Index (PSI) is suggested for use on a voluntary basis by State
and local air pollution control agencies wishing to use an index
approach for reporting ambient air quality. The PSI transforms
daily concentrations of the criteria pollutants into a uniform
scale ranging in severity from 0 to 500, where 0 to 50 is "good,"
50 to 100 "moderate," 100 to 200 "unhealthful,' 200 to 300 "very
unhealthful," and greater than 300 "hazardous." The index provides
the public with appropriate generalized health effects and caution-
ary statements.
As a concluding observation, SAMWG believes that EPA should
take a more active research role in determining the usefulness of
personal air pollution samplers to measure the exposure dose to
representative individuals. Increasingly, air pollution control
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agencies are being challenged on the use of fixed station ambient
monitors to support regulatory activities. Challengers point to
limited studies which show that fixed station data have no direct
relationship to exposures actually received by a mobile population.
Thus, they argue that SIP's based on fixed station monitors can
be overly lax, or conversely, too restrictive in terms of emission
controls needed to achieve ambient air quality standards. These
assertions could be objectively tested if personal monitoring
devices could be used to establish relationships between personal
exposure and concentration patterns at fixed monitoring locations.
Hopefully, such relationships could be used to calibrate or adjust
fixed station data to more adequately represent actual exposure
received by certain sensitive population groups.
SUMMARY OF RECOMMENDATIONS
t EPA should determine the minimum data analysis capabilities
needed by air pollution control agencies in order to properly
interpret and distribute monitoring information. These
minimum capabilities should be used as guides by EPA and
control agencies in assessing needs for resources for data
analysis.
• Isopleth concentration displays should be developed
and kept current for selected metropolitan areas having large
populations (e.g., exceeding 1,000,000). Where practicable,
such displays should also be made of baseline (e.g., 1970)
air quality in order to present trends graphically.
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t EPA should develop a guideline document dealing with
isopleth concentration displays.
t Control agencies are encouraged to use EPA's Pollutant
Standards Index (PSI) to inform the public of day-to-day
changes in air quality.
t EPA should initiate research to determine the feasi-
bility of using personal monitors to measure the exposure
dose to representative individuals.
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CHAPTER VIII
ANTICIPATED IMPACT OF STRATEGY
INTRODUCTION
Expenditures for air pollution control of State and local
agencies are shown in Table VIII-1. In FY1976, nearly 150 million
dollars was spent, of which nearly 30 million (or 20 percent)
was devoted to ambient air monitoring activities. Total spending
increased by 4.6 percent over FY1975, compared to an increase of
16.4 percent in resources for air monitoring. The greater increase
in air monitoring resources in FY1976 as compared to total agency
resources is attributed to increased quality assurance activities
and special monitoring studies. Although quality assurance activ-
ities of State and local agencies have increased slightly, this
increase is in many cases insufficient to implement adequate
programs at all levels where monitoring is conducted.
Table VIII-2 shows a breakdown of resources expended for
ambient and source monitoring activities in FY1975. This shows
that nearly 18 million dollars was spent in FY1975 on source
monitoring activities, which includes emission inventories,
source testing, and special source monitoring activities.
OVERALL IMPACT OF MONITORING STRATEGY
It is anticipated that the resources associated with air
pollution control activities in general and air monitoring activi-
ties in particular will not change substantially in the near
future. Thus, SAMWG's attention has been directed to the reallo-
cation of the total resources available for monitoring so that
they will be used more effectively. As an example, resources
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TABLE VIII-1
STATE AND LOCAL CONTROL AGENCY
EXPENDITURES ON AIR POLLUTION CONTROL ACTIVITIES
Source
Federal
Non-Federal
Ambient Air
Monitoring
TOTAL
FY1975 (OOP's)
FY1976
% Change
$51,900
$91 ,200
$143,100
28,600*
$55,300
$94,400
$149,700
33,300
+6.6
t3.5
+4.6
+16.4
*FY-1975 estimates for ambient air monitoring resources shown in Table VIII-2 also include
EPA expenditures and thus the total is higher.
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TABLE VIII-2
STATE, LOCAL AND FEDERAL EXPENDITURES
ON AIR MONITORING ACTIVITIES, FY1975
Ambient Air
TOTAL
$ (OOP's)
SIP Networks 23,900
Special Purpose Monitoring 4,500
Quality Assurance3 3,300
31,700*
Source $ (OOP's)
Emission Inventories 6,600
Source Testing 8,400
Special Studies 2,700
TOTAL 17,700
l\3
Quality assurance activities apply to both source and ambient.
About 85% is used for enforcement purposes.
*FY-1975 estimates for ambient air monitoring resources shown in Table VIII-1 does not include
EPA expenditures and thus the total is lower.
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113
saved on reduction in the operation of tape sampler networks
could be used for increased quality assurance activities or
for additional special purpose monitoring, including analysis
and reporting of data in non-attainment areas. Table VIII-3
provides a qualitative picture of how monitoring resources might
be affected by the monitoring strategy on a national basis.
In the area of data handling, for example, it is expected
that resources needed at the Regional Office level will increase.
Additional resources may be needed by some RO's since the strategy
will involve new or additional responsibilities in the area of
data storage and retrieval of SLAMS data. It is anticipated
that the greatest increase in resources will be needed during
the implementation phase of the strategy in order to develop new
operations in those Regions who elect to store SLAMS data. Once
underway, these programs should not call for substantial added
resources for maintenance. However, it is recognized that in
many areas, additional resources will be needed to implement a
fully operational quality assurance program. Further, purchase
of new continuous type instruments to complete the NAQTS network
or to replace obsolete instrumentation will require additional
resource committments. SAMWG recommends that new resources be
made available for these purposes from Federal, State and local
sources.
RESOURCES FOR AMBIENT AIR MONITORING
Impact of NAQTS Strategy
Estimates were made of resources needed for operation of
the National Air Quality Trend Station (NAQTS) network. (This
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TABLE VIII-3
ESTIMATED NATIONAL RESOURCE IMPACT OF SAMWG STRATEGY£
EPA
EPA
Element Headquarters
NAQTS
Sampling & Lab. Analysis
Data Reporting
SLAMS
Sampling & Lab. Analysis
Data Reporting
SPM
Sampling & Lab. Analysis
Data Reporting
Non-Criteria
Sampling & Lab. Analysis
Data Reporting
Data Analysis and Interpretation
(inlcuding modeling)
Quality Assurance
Emission Inventories
Source Testing
Same,
Same
N/J
Same0
Increase
Same0
Increase
Increase
Increase
Increase
Same
Same
Regional
Office
Same
Decrease
Same
Increase
Increase
Increase
Increase
Increase
Increase
Increase
Same
Same
State
Agencies
c
Decrease
Decrease
Increase
Increase
Increase
Increase
Increase
Increase
Increase
Increase
Increase
Increase
Local
Agencies
c
Decrease
Decrease
Increase
Increase
Increase
Increase
Increase ,-.
Increase £
Increase
Increase
Increase
Increase
Table indicates changes expected nationally over the next five years in relation to current
expenditures. Individual State or local agency impact may deviate from the national average.
Increases in CDHS activities and clearinghouses will roughly balance out any savings in handling
a reduced national air quality data base.
cSome agencies may experience temporary increases due to the need to replace unapproved instrumentation
N/A - Not applicable.
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115
network is discussed in detail in Chapter III.) The resource
estimates include operation of equipment, analysis of samples,
quality assurance and supervision.
Table VIII-4 presents current resource estimates for
the NAQTS network in comparison to the Federal minimum requirements
under 40 CFR 51.17 and existing State and local networks.
There are several noteworthy points to be made concern-
ing TABLE VIII-4. First, the resources allocated to each pollutant
monitoring program should not be taken to imply the relative
importance of the pollutant or the monitoring program. For
example, the fact that more resources are needed for Oo NAQTS
than for CO NAQTS does not necessarily mean that the 03 air
quality management program is more important or more difficult.
It reflects the relative cost of the monitoring devices and number
of devices needed in each geographical area in order to provide
a sufficient trend data base to satisfy EPA Headquarters needs.
Second, the reader should not infer that the establishment
of NAQTS will automatically result in a reduction in ambient trend
monitoring activities and associated monitoring resources. That
is, if the NAQTS strategy becomes the new Federal minimum require-
ment for EPA HQ data needs, a resource savings of $8.0 million
(14.7 minus 6.7) will not necessarily result. This is due to
the fact that the NAQTS represents a fraction of the total moni-
toring effort necessary on a national basis. The SLAMS network
and SPM projects will continue to provide the bulk of data necessary
to support SIP control actions. However, it is hoped that during
the establishment of the NAQTS, the State and local agencies will
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TABLE VIH-4
CURRENT RESOURCE ESTIMATES3 FOR OPERATION OF NATIONAL AIR
QUALITY TREND STATIONS (NAQTS) AND STATE/LOCAL AIR MONITORING STATIONS (SLAMS)
MILLIONS OF DOLLARS
Pollutant
TSP
Hi-Vols
Tape Samplers
so2
CO
Oo
TOTAL
SLAMS Strategy
2.5 - 3.1
0.2 - 0.4
4.2 - 6.7
2.2
2.0
1.8 - 2.9
12.9-17.3
NAQTS Strategy
Federal Minimum
Requirements
(40 CFR51.17)
6.7
14.7
Existing State &
Local Networks
0.9
b
2.3
1.1
1.4
1.0
1.7
2.9
6.5
1.1
1,4
1.1
4,3
2.2
10.7
3.3
3,4
4.7
28.6
The costs include: capital costs for purchase amortized over a five year period and annual
costs which include quality assurance, data handling, operation of
instrument, maintenance and supplies, and supervision.
DTape samplers are not included in the NAQTS strategy. They may be used for TSP emergency episode
prevention and thus should be included in the SLAMS network.
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117
critically review the need for each of their fixed monitoring
stations and eliminate those that are unnecessary.
Impact of SLAMS Strategy
In addition to the NAQTS network, the State and local
agencies will be performing additional fixed station monitoring
(State and local air monitoring stations) in support of SIP
activities. The amount of SLAMS type monitoring will vary from
place to place depending on the need for air quality information.
Therefore, it is not possible to present definitive resource
estimates for this monitoring category until the States have
completed an analysis of their monitoring activities in conjunction
with the appropriate EPA Regional Offices. However, a rough
estimate of resources for SLAMS activities has been made, and is
shown in Table VII1-4.
Impact of Special Purpose Monitoring (SPM)
Current special purpose monitoring resource estimates
have been estimated to be around 4.5 million dollars for FY1976.
This total should increase as a result of SAMWG's increased
emphasis on special purpose monitoring. It is expected, however,
that the total resource available for air monitoring will remain
the same or perhaps increase slightly. Thus, the total expenditures
for SLAMS and SPM will be the difference between the total moni-
toring resource and that required for NAQTS. It is SAMWG's estimate
that most of this difference will be placed into SLAMS monitoring
over the next few years, with SPM monitoring perhaps increasing
slightly. As air quality approaches standards, the need for
SPM will increase in order to provide more specific information
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118
about why standards are not being attained. However, if new air
quality standards are established, there may be needs for addi-
tional monitoring of the type done with NAQTS and SLAMS.
Resources for Source Monitoring
SAMWG estimates that resources for source monitoring should
not change significantly as a result of the strategy. Overall re-
sources needed for emission inventory activities may increase slightly.
Since data will be reported less often for many areas, expenditures
should decline. However, there will be a need for increased inven-
tory activity and associated resources for fugitive emissions sources
and hydrocarbon sources. Also, there will be increased resource
requirements in areas where dispersion models are necessary.
Few changes in source testing activities have been recom-
mended by SAMWG. Thus, there should be no significant change in
the resources being expended in this monitoring strategy. However,
continuing activities in the area of NSPS will result in a need
for additional resources as new industrial categores are regulated.
These resources will be needed for stack sampling and continuous
in-stack monitoring by affected sources.
Expected Benefits of the Air Monitoring Strategy
The benefits to be expected from implementation of the
proposed monitoring strategy are summarized in Table VIII-5 through
VIII-8 for each of four principal data uses. For example, under
the use "judge attainment of NAAQS" the three strategy components
outlined above are cross tabulated with areas for which attainment
decisions are of greatest general concern. Note that establishment
of trend sites (both NAQTS and SLAMS) meets most of the data needs
to judge attainment of NAAQS in urban areas but does not meet
these needs around point sources. To make adequate attainment
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119
judgments around major point sources, additional resources may
be needed for special purpose monitoring and modeling. The
appropriate mix of resources to be used for the three strategy
components will depend on source size, the applicability of models
for the particular source-pollutant configuration, and the extent
of available monitoring resources..
The proper use of the three strategy components will
result in an overall monitoring strategy capable of meeting the
principal uses of monitoring data.
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DATA USE:
TABLE VIII-5
JUDGE ATTAINMENT OF NAAQS
MEETS DATA USE/COMMENT
STRATEGY COMPONENT
URBAN
POINT SOURCES
MAX CONG. AREAS
Fixed Station Monitoring
(FSM)
Special Purpose
Monitoring (SPM)
Air Quality
Modeling (AQM)
YES, high quality
data from FSM* suit-
able for areawide
NAAQS judgments
PARTIAL. Special Pur-
pose monitors will
supplement FSI1* and
NAAQS attainment judg-
ments in local areas
OPTIONAL. Can be used
to identify areal
extent of air quality
problem in selected
areas
NO. will require
special purpose
and movable moni-
toring in conjunc-
tion w. modeling
YES. SPM moni-
tors will be used
to calibrate models
& establish NAAQS
violations. Special
purpose fixed-sta-
tions (e.g. SCS)
will also suffice
for some sources
PARTIALLY. Models,
where appropriate,
will be used to
identify areas
around sources above
NAAQS needing moni-
tors
PARTIALLY, the FSM* are
generally located in max
concentration areas. Local
"hot spots" must be iden-
tified w. movable monitors
PARTIALLY. SPM monitors
will be used to identify
"hot spots" & establish
fixed stations as needed
ro
o
PARTIALLY. Models will be
used to augment movable
monitors and FSM* to locate
stations in "hot spots"
Net Impact of
Strategy to Judge
Attainment of
NAAQS
YES. Data from FSM*
augmented by SPM &
AQM as needed
YES. Primarily based
on AOM & SPM Special
purpose fixed sta-
tion networks (e.g.
SCS) will suffice in
some cases
YES. Combination of data
from FSM*, SPM & AQM
FSM includes National Air Quality Trend Sites
Sites (SLAMS)
(NAQTS) and State and Local Air Monitoring
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TAHD3 VIII-6
DATA USE: REVISE SIP CONTROL STRATEGIES
MEETS DATA USE/COMMENT
STRATEGY COMPONENT
URBAN
POINT SOURCES
MAX CONC. AREAS
Fixed Station Monitoring
(ESM)
Special Purpose
Monitoring (SPM)
Air Quality
Modeling (AQM)
YES. The FSM* will be
primary base of high
quality data for SIP
revisions
YES. SPM monitors
likely to play vital
role to validate ex-
tent of air quality
problem, determine
specific source im-
pact, etc.
OPTIONAL. In some
urban areas, model-
ing will be used to
define sources need-
ing additional control
NO. Point source oriented
SIP revisions will be
based more on special
purpose networks, movable
monitors, supplemented by
modeling
YES. SPM monitors
will be key to success
of SIP revisions, esp.
around isolated point
sources. Also needed to
validate point source
models required for SIP
revisions
YES. Point source model-
ing, where appropriate,
will be basis of projected
air quality impacts & emis-
sion control strategies
PARTIALLY. The FSK* are
generally located in
max concentration areas
& are critical in SIP
revisions
PARTIALLY. SPM moni-
tors will be required to
document air quality "hot
spots" and determine
sources & conditions
causing max concentrations
YES. Revisions to SIP'3
will rely on use of air
quality modeling to insure
"hot spots" are adequately
controlled
Net Impact of
Strategy to Revise
SIP Control Stra-
tegies
YES. Combination of
FSM*, SPM and modeling
will suffice for SIP
revisions in urban
areas
YES. Combined use of
SPM and modeling will
suffice for SIP revisions
for individual point
sources
SfES. Combined use of model-
and data from SPM will
suffice to insure adequate
controls of "hot spots"
*FSM includes NAQTS and SLAMS monitoring
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DATA USE:
TABLE VII1-7
AIR QUALITY PROGRESS AND TRENDS
MEETS DATA USE/COMMENTS
STRATEGY
COMPONENT
URBAN
MAX. CONG.
ESTIMATE POPULATION
EXPOSURE
BACKGROUND
Fixed Station
Monitoring (FSM)
Special Purpose
Monitoring (SPM)
Air Quality
Modeling (AQM)
Net Impact of
Strategy to Evaluate
Air Quality Progress
and Trends
YES. Areawide air
quality trends
NO. Trends primary
determined by FSM*
OPTIONAL. Can be
used to augment FSM
& to project area-
wide air quality
programs
YES. Data from FSM
supplemented by
AQM
NO. Requires spec-
purpose fixed sta-
tions
YES.Requires combi-
nation of special
purpose monitors &
modeling
YES. Will be used
to assess point
source emission/
air quality
improvements
YES. Data from AQM
AND SPM
PARTIALLY. Must
supplement FSM*
with SPM
PARTIALLY. Used to
spot check high
growth areas to
establish FSM*
YES. Models cali-
brated with FSM anc
SPM to project
maximum concentra-
tion improvements
YES. Data from AQM
supplemented from
FSM and SPM
PARTIALLY. Must
supplement FSM*
with SPM & area-
wide models
PARTIALLY. To sup-
plement FSM* and
establish concen-
trations in un-
monitored areas
YES. U.sed with FSM
for calibration of
areawide models to
estimate trends in
population expo-
sure.
YES. Data from AQM
supplemented with
data from FSM &
SPM
PARTIALLY. Few FSM*
monitors in background
areas must be supple-
mented by SPM & models
PARTIALLY. Combined
with FSM* stations
to estimate background
levels
PARTIALLY. Expected
and actual air qual-
ity trends in back-
ground concentrations
based on emission
growth and models
YES. Combination of
data from FSM, SPM,
and AQM
ro
ro
*FSM includes NAQTS and SLAMS
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DATA USE:
TABLE VIII-8
NEW SOURCE REVIEW/PREVENT SIGNIl'ICANT DETERIORATION
MEETS DATA rTSS/COMMENT
STRATEGY COMPONENT
BASELINE AIR QUALITY
PROJECT AIR QUALITY INCREMENTS
Fixed Station Monitoring
(FSM)
Special Purpose
Monitoring (SPM)
Air Quality Modeling
(AQM)
PARTIALLY. Portions of the
FSM* network will be useful
to estimate baseline air
quality in areas experi-
encing growth or expecting
new sources
PARTIALLY. New sources
be required to document
baseline air quality before
construction. SPM will
augment baseline data
PARTIALLY. Modeling will be
required for areas where
baseline data are insuffi-
cient or not appropriately
obtained otherwise
NO. The FSM* Wni be useful, how
ever, in validation of models
needed to project air quality
increments
NO. SPM will be also used to
validate models used in air
quality projections
ro
GO
Modeling or rollback will
be necessary to estimate growth
and new source air quality
impacts
Net Impact of Strategy
to Review New Sources/
Prevent Significant
Deterioration
Combination of all 3
strategy components depend-
ing on source size, availa-
bility of data, etc.
YES. Validated models will be
principal tool for projecting
air quality increments
*FSM includes NAQTS & SLAMS
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124
CHAPTER IX
IMPLEMENTATION OF STRATEGY
INTRODUCTION
In developing the strategy proposed in the preceding chapter,
the members of the Standing Air Monitoring Work Group (SAMWG) pro-
ceeded on the premise that the current air monitoring program is per-
forming reasonably well and constitutes a sound base from which to
improve its responsiveness and cost-effectiveness. Accordingly, the
resultant strategy is designed to build upon this framework in an
evolutionary manner rather than to force major changes to be imple-
mented abruptly. Implementation of all of the new or revised activi-
ties called for, or implied by, the strategy cannot be accomplished
quickly. The critical role of monitoring within the Air Program dic-
tates that any substantial change be carefully planned and managed. To
do otherwise, entails the risk of decreasing the effectiveness of other
activities dependent upon monitoring. Due to these considerations, SAMWG
recommends that this strategy serve as a blueprint for change over
a five-year period starting in fiscal year 1978. By phasing the
strategy in over five years, control agencies should have sufficient
time to carefully plan the technical changes involved and in most
cases will have sufficient time to program for the resource adjust-
ments required. Comments offered at the four air monitoring work-
shops held in January 1977 indicated that some agencies foresee
fairly severe resource limitations for the next five years. Others
indicated that while they did not foresee severe resource limitations,
they felt that the strategy called for too many of the action items
to be accomplished during the first two years of the implementation
period. They felt that the strategy should allow each agency to
-------
125
have a greater say in planning the pace and sequence of particular
items in the strategy based upon their respective needs, capabilities,
and resources. As a result of these comments, SAMWG reconsidered its
proposed implementation schedule and revised its expectations about
implementation to provide more State and local flexibility. Due to
the importance of quality assurance, SAMWG reaffirmed its recommenda-
tion to implement the quality assurance program during the first
12 months. SAMWG has lengthened the implementation period for the
major ambient recommendations to provide one- to three-year implemen-
tation schedule. SAMWG felt that changes to the ambient monitoring
program were the most critical and should thus receive the highest
priority effort during the initial 1-3 years of the implementation
period. Action items dealing with other areas of the strategy will
generally be implemented over a longer period of time.
In view of the need to provide some overall guidance and struc-
ture for the implementation of this strategy, SAMWG foresees that
EPA's Annual Program Guidance (prepared prior to the start of each
fiscal year) will serve as a vehicle for focusing effort on the objec-
tives to be stressed during the next fiscal year. This Annual
Guidance will include strategy objectives for the EPA regional offices
(RO's) and for particular EPA headquarters components. In preparing
their annual program plans, all EPA offices are expected to commit
themselves to the accomplishment of as many of these desired objec-
tives as are possible within their resources. Necessarily, many of
the regional office air monitoring objectives will require action
by State and/or local agencies. For FY-1978, SAMWG has recommended
that the States develop plans and schedules for implementing SAMWG's
major recommendations pertaining to ambient monitoring activities.
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126
As outlined under the first major section in Table IX-1, these plans
will encompass a broad range of activities, many of which are critical
to assessing NAAQS attainment and maintenance. SAMWG recommends that
the RO's take an active role in assisting State and local agencies with
such plans, particularly in regard to planning the respective roles of
the RO's and State and local agencies in storing, reporting, and
analyzing ambient data in the future. The plans to be prepared early
in FY-1978 will serve to structure and document the approach and
schedule for the major ambient monitoring changes.
SAMWG recognizes that the specific milestones contained in
these initial plans may have to be modified in the future due to
factors such as unforeseen resource constraints and changes in con-
trol agency needs and priorities. In addition to playing a cooperative
role in planning, the RO's are expected to have an active role in
assisting control agencies in program evaluation and in providing
technical assistance in new, specialized, or problem areas of air
monitoring. In some cases, the EPA RO's may choose to incorporate some
part of these objectives as outputs expected under an agency's Control
Program Grant. The particular terms and conditions would be negotiated
annually by the RO's and the grantee agencies.
In order to refine the objectives to be set forth in each year's
Annual Program Guidance, SAMWG recommends that periodic evaluations
be performed of the progress achieved in implementing the strategy.
Such evaluations should be conducted as a joint effort between the
State and local agencies , EPA headquarters, and the RO's, and be as
informal as possible with a minimum of special reporting by all
parties concerned. While resource limitations will, of course, be a
key factor in the process, the dynamic nature of the Air Program and
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127
its impact on air monitoring should also be recognized. Over the next
five years, most, if not all, State and local agencies will be faced with
changing needs for monitoring data. Such changes will arise from
changes in present programs, and may well result from future
amendments to the Clean Air Act. In addition, the state-of-the-art
in air monitoring will presumably be advancing during the period.
This will mean that new and improved measurement equipment and
techniques will become available and, hopefully, many of the
shortcomings in current monitoring methodologies will be resolved.
In light of these considerations, SAMWG believes that neither EPA
nor the State and local agencies should view the strategy as a
set of static requirements for judging progress. Therefore,
periodic evaluations should broadly consider all major activities
which impact on air monitoring.
IDENTIFICATION OF MAJOR STRATEGY ACTIONS
Chapters III-VII of this document have presented a large
number of recommendations. Many of these explicitly identify some
new activity or program which should be implemented. A substantial
number, however, emerge mainly by implication. As an example of
this type, one might cite the need to take a more critical view
of special purpose monitoring. It is not the purpose of this
chapter to try to restate all of the many activities and tasks
already presented. It will attempt to focus on the major actions
to be undertaken during the next five years. Table IX-1 presents
a summary of these actions with an identification of the organiza-
tion^) responsible and the estimated implementation period.
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TABLE IX-1 SCHEDULE OF STRATEGY ACTION ITEMS
Action Item
Responsible
Organizations)
Period of
Implementation
Ambient Criteria Pollutant Monitoring
* Modify Regulations regarding networks and siting
(40 CFR 51.17)
* Develop plans for implementation of changes to
ambient monitoring program during the FY 1978-82
period. Plans to address as a minimum:
--Estimate of resources required to implement
monitoring program guidance
--Development of minimum quality assurance pro-
gram (See expanded description on p. 129)
--Review of networks
--SLAMS/NAQTS designation
--Completion of SLAMS/NAQTS designation
--Annual program for major Special Purpose
Monitoring (SPM) projects
--Review of meteorological data
--Development of capability to display popula-
tion exposure trends
--Development of operational data storage
and submission systems
--Development of capability to prepare annual
summary reports of SLAMS data
Clearinghouse for Monitoring Information
(Criteria and Non-Criteria Pollutants)
* Initiate cost and technical feasibility study
* Prepare operating procedures, make organiza-
tional arrangements and request OMB approval
of information collection form.
* Prepare specifications for information handling
.system and receive approval of information
collection form from OM8.
EPA, Office of Air
Quality Planning and
Standards (OAQPS)
State/local agencies
to develop ambient moni-
toring plans with guidance
and technical assistance
from the Regional Offices.
EPA, Office of Air
Quality Planning and
Standards (OAQPS)
Promulgation of Regulations by mid-1978.
Initial plans to be developed during the first
quarter of FY 1978. In preparing the FY 1978
program guidance dealing with development of
these plans, SAMWG has recommended that most
plan components be implemented during the FY
1978-80 period if at all possible. The minimum
quality assurance program, however, must be
implemented by the end of FY 1978. The imple-
mentation schedules for all other plan components
should reflect each agency's respective needs,
resources and capabilities. In general, imple-
mentation pf all components should be accom-
plished within 5 years, however agencies having
severe resource constraints may require longer
than 5 years to implement some components of the
strategy.
ro
00
Study to be started by June 1977 with results due
b.y November 1977.
Procedural and organizational arrangements to be
completed by February 1978; approval of form to be
initiated in February 1978.
System specifications and form approval activities
to be completed by August 1978.
• Collect initial information for clearinghouse
* Develop information handling system and check
and prepare initial information
To begin August 1978 and ba cc-molstac by ,-icv2rcber
1978.
System development to begin August 1978; checking
and preparation of information to begin November
1978; both to be completed by January 1979.
-------
TABLE 1X-1. SCHEDULE OF STRATEGY ACTION ITEMS (CONT'D)
Action Item
Responsible
Organlzatlon(s)
Period of
Implementation
• Clearinghouse operational with Initial Information
base.
Source/Emission Inventories
• Establish work group to recommend Improved Inventory
procedures and define possible revisions to data
items in inventories of sources emitting criteria
pollutants.
* Develop complete inventories including point sources
having potential emissions of 100 or more tons/year
and area sources at the county level.
* Prepare annual update of emission inventories in all
areas where NAAQS are either violated or threatened.
* Annually submit to EPA updated information on all point
sources having actual emissions of 100 or more tons/yr
and on area sources in counties where NAAQS are either
threatened or violated. Where the control agency knows
of no change to the inventory, updating can be done by
submission of changes to the year of record.
Enhance Control Agency Quality Assurance Programs (Ambient
and Source)
* Develop a written State quality assurance policy which
will be reviewed and approved by EPA for consistency
with National quality assurance policy.
* Review of existing measurement methods and other major
quality assurance procedures and participate in per-
formance surveys. Correct procedures as required.
* Develop and implement data validation procedures, train-
Ing schedules and maintenance activities.
OAQPS
OAQPS, and representatives
from State and local agencies
and Regional Offices
State/local agenices with tech-
nical assistance from the
Regional Offices
State/local agencies with tech-
nical assistance from the
Regional Offices.
State/local agencies with tech-
nical assistance from the
Regional Offices
State/local agencies to have pri-
mary role. EPA to review, approve
and provide technical assistance.
State/local agencies to have pri-
mary role. EPA to review, approve
and provide technical assistance.
State/local agencies to have pri-
mary role. EPA to review, approve
and provide technical assistance.
Operational by January 1979.
Work group should be established by August 1977 and
develop recommendations by December 1977.
This activity should begin early in FY 1978 and
be completed by the end of the fiscal year.
This activity should be done annually starting
In FY 1979.
Annual submissions will be required as soon as
revised reporting regulations (40 CFR 51.7) have
been promulgated. Promulgation should be done by
early 1978.
Preparation of written policies to begin by October
1977 and be completed by January 1978. Annual
review of policy, thereafter.
Initial review of methods and procedures to be
completed by April 1978. All necessary corrections
implemented by July 1978.
A deffned data validation procedure should be
operational by October 1978. Maintenance schedules
and training plans should be developed and imple-
mented by October 1978.
ro
«o
Non-Criteria Pollutant Monitoring
• Develop and implement Improved functional management
scheme.
Research and Program Offices
within EPA
A detailed analysis, with recommendations con-
cerning alternate ways to accomplish this should
be initiated during the latter part of FY 1977.
The development of policies and assignment of
organizational responsibilities should be
accomplished early In FY 1978.
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TABLE IX-1 SCHEDULE OF STRATEGY ACTION ITEMS (CONT'D)
Action Item
Responsible
Organization(s)
Period of
Implementation
Establish program to analyze selected NAQTS samples
for non-criteria pollutants.
Establish anticipatory program of monitoring R&D.
Data Systems—Planning and Operations
* The Regional Offices should consult with State/local
agencies to evaluate their respective needs for SLAMS
data and SPM data and to determine the optimum loca-
tion for storage of such data.
* Subsequent to the above review, a written plan should
be prepared for the development/acquisition and in-
stallation of storage and retrieval systems which
meet these needs. (This will be one component of each
State's plan for ambient monitoring.)
* Technical support to suers of the Comprehensive Data
Handling Systems (COHS) should continue at a high
level and expanded retrieval capabilities should be
developed.
Develop Revised Regulations for Reporting Data (40 CFR 51.7)
* Establish informal work group to recommend and define
monitor site information items needed to document each
NAQTS site.
* Establish formal work group to develop revised
reporting regulations for air quality and emission
data.
Submission of NAQTS samples
will be by State/local agen-
cies. Lab analysis and report-
ing of results by EPA, ORD
Research and Program Offices
within EPA
Regional Offices and State/local
agencies with technical assist-
ance by OAQPS
Regional Offices and State/local
agencies.
OAQPS
OAQPS, and representatives from
State and local agencies and
Regional Offices
OAQPS and selected representa-
tives from other EPA organiza-
tions
Procedures for submission, analysis and reporting
to be developed and distributed by November 1977.
Analysis to start with samples collected on and
after January 1, 1978.
Implementation of a planned methods development
program should begin in FY 1978. To the extent
which resources are available, the pilot network
of non-criteria monitors should become at least
partially operational in FY 1979.
The needs evaluation should begin by the latter
part of FY 1977. Optimum storage locations
should be determined by December 1977.
Planning for new-revised storage and retrieval
systems should be done during the first quarter
of FY 1978. The specific implementation period
for each agency will be jointly determined by the
Regional Offices and the State/local agencies con-
cerned.
A high level of technical support should be con-
tinued for the next several years. Additional
retrieval packages will be furnished to CDHS users
in FY 1978. Additional CDHS improvements will be
developed annually thereafter.
Work group should be established by April 1977 and.
develop recommendations by August 1977.
Work group should be established by May 1977.
Revised regulations should be promulgated by
mid-1978.
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TABLE IX-1 SCHEDULE OF STRATEGY ACTION ITEMS (CONT'D)
Action Item
Responsible
Organizations)
Period of
Implementation
EPA Guidance/Documents
• Source Inventories
* Monitoring networks and siting
• Point soruce monitoring
• Diffusion modeling
* Statistical analysis techniques (peak values,
trends, adjustment for meteorology)
* Quality assurance
* Analytical methods (technical assistance
documents)
* Data display techniques
Air Quality Analyses
* Develop technical guideline presenting tech-
niques and procedures for use in developing
isopleth concentration displays.
* Review data bases to determine feasibility
of developing population exposure trend displays
for large metropolitan areas (e.g. exceeding
1,000,000 population).
Preparation of population exposure trend
displays for large metropolitan areas where
the data is suitable.
OAQPS
OAQPS
Office of Enforcement
OAQPS
OAQPS
ORD
ORD
OAQPS
OAQPS
State and local agencies.
The Regional Offices will
coordinate interstate analyses
and provide technical assistance
If requested, OAQPS will also
provide1 technical assistance.
The documents referred to consist of new publica-
tions as well as updates to existing publications
Several are already in progress while the need
for others has only recently been Identified.
Guidance documents should be made available to
users prior to the period when the program
addressed by the guidance is to enter a new phase
Therefore, development of a number of guidance
documents will be done in phases over the next
several years. In most cases, firm schedules for
particular guidance documents should be estab-
lished annually in EPA's program plans. Special
needs may dictate the development of guidance
for which no need was identified during the annual
planning process.
Guideline should be initiated by April 1977 and
released to State and local agencies by October
1977.
These reviews should be completed by the end of
FY 1978.
Displays should be prepared by the end of FY 1980
if data bases are suitable.
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APPENDIX A
COMPILATION OF QUESTIONS CONCERNING THE AIR
MONITORING PROGRAM
ADEQUACY OF SIP MONITORING NETWORKS
• Are SIP ambient monitoring networks proper in terms of num-
bers and location of stations for the purpose of tracking
SIP's (trends, attainment and maintenance)?
• Do SIP networks provide comprehensive data for the purpose of
informing the public on progress towards achieving acceptable
air quality?
• Are SIP networks adequate for supporting regulations and
enforcement actions?
• Does the present number and location of monitoring sites
provide an effective measure of respective ambient levels
in urban areas? In nonurban areas? In vicinity of large
point sources?
• Can the present combination of continuous and intermittent
sampling equipment be shifted to different sampling schedules
which will improve their utilization while preserving a sta-
tistically sound sampling scheme?
• What is the feasibility of meeting SIP data needs with a
mixture of fixed stations and mobile monitors?
Can urban S02 and TSP networks be reduced in size in areas
where NAAQS are infrequently exceeded or where air quality
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A-2
patterns are well defined without sacrificing needed infor-
mation?
• Can information lost by network cutbacks be more than ade-
quately compensated by relocation of monitors to higher
priority areas or pollutants? What are the potential resource
savings of such a policy? How could such a policy be effec-
tively implemented and over what time frame?
• Are monitors currently sited to represent population exposure?
• What steps need to be taken to ensure more representative
siting of instruments in the future?
• Is our current state of knowledge adequate to define specific
criteria for locating monitoring instruments to meet EPA,
state, and local needs?
• What information should be developed or studies performed
to provide better guidance on the numbers and location of
monitors?
SOURCE AND EMISSIONS DATA
• What are the specific needs for source and emissions data
required by EPA and State and local agencies?
• Is the present system for gathering source data and estab-
lishing emissions inventories adequate to meet the needs of
EPA and State and local agencies?
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A-3
• Are reports from states regarding source activity and source
emissions complete, timely, and accurate enough to meet these
needs?
POINT SOURCE MONITORING
• Should ambient monitoring around point sources currently
regulated by SIP's be increased?
• Should this monitoring be used to support enforcement actions
against sources not in compliance?
• What types and size of sources should be candidates for such
monitoring?
• What legal and administrative actions can EPA take to require
such monitoring?
• What additional pollutants besides those governed by NAAQS
should be considered in any point source ambient program?
• Should EPA advocate that sources conduct ambient monitoring
for reporting to EPA as a condition for operating permits
and actions concerning variances, etc.?
• Can EPA initiate a system of conditions and checks on sources
to ensure that adequate data are obtained in such instances?
• What resources would be required to initiate such a system
and what types of sources would likely be affected?
MONITORING UNREGULATED POLLUTANTS
• For what pollutants should EPA be developing a monitoring
program?
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A-4
• Is the current program for obtaining data for such pollu-
tants as sulfates, nitrates, organics, trace metals adequate
in terms of the extent of monitoring coverage and analysis
of subsequent data?
• What are the specific needs for monitoring data and informa-
tion regarding these pollutants?
• What kinds of analyses should be applied to these data and
how should these data and subsequent analyses be evaluated?
• Is there a need to store information about these pollutants,
in a centralized clearing house?
USE OF AIR QUALITY MODELS
• Are air quality models being used as effectively as they
might be used for planning purposes and for augmenting infor-
mation from conventional monitors?
• Should calibrated models be used to establish specific
source control actions either with or without supporting
data from conventional monitors?
• What should be the agency's policy regarding the use of air
quality models?
• What are the potential costs/benefits of such a policy and
how might it be implemented? What are the specific data
requirements?
• What degree of credibility do models have and to what degree
must uncertainties be reduced to ensure ready acceptance
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A-5
in formulating policy and adopting specific control
measures?
DATA AND INFORMATION QUALITY
• What are the essential elements of a comprehensive quality
assurance program and how should they be implemented?
• What kind of system is needed to inform data users of the
quality of the information derived from ongoing monitoring
programs?
• What are the projected costs to the agency in terms of
credibility loss, enforcement, and implementation setbacks
if a more effective quality assurance program is not
implemented?
• What should be the specific priorities for implementation
of an overall quality assurance program in terms of payoffs
to control and enforcement programs?
AIR QUALITY REPORTING
• Can EPA make valid national air quality assessments with
data from a smaller number of monitoring stations than now
reporting to EPA?
• Must EPA have raw data from all of the routinely reporting
stations or would summary air quality statistics suffice?
• Should other information, such as the frequency of episodes,
be collected from the states and if so, how often?
• Should EPA establish a "rapid" air quality reporting system
to collect and report data from selected areas?
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A-6
• What data are needed from other agencies for EPA to properly
evaluate population-at-risk and population exposure to
various pollutants?
• How can EPA better publicize monitoring information and the
impacts of pollutant levels on public health and welfare?
DATA PROCESSING AND SUPPORT SYSTEMS
• Specifically, what is the hierarchy of data needs and data
analysis capabilities required to carry out EPA's monitor-
ing programs?
• Can the existing ADP systems and planned program of enhance-
ments realistically meet existing and projected needs for
monitoring and data analysis?
• If not, what kinds of alternative systems are needed for
use in air quality planning, in evaluating the effective-
ness of the SIP's, and in developing control regulations?
• Are efforts spent in data analysis adequate, especially in
light of the costs required for monitoring?
• Should regions be developing their own systems to deal with
the specific problems peculiar to the regions?
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APPENDIX B
SUMMARY OF ISSUES AND'RECOMMENDATIONS FROM ISSUE PAPERS
This appendix lists the issues raised and the recommendations
made in eight of the nine issue papers prepared by the Standing Air
Monitoring Work Group. No issues and recommendations were presented
in the paper "Background and General Considerations in the Develop-
ment of Strategy Issues for Improvement in Air Monitoring." The
purpose of this paper was to set forth general considerations and
background information valid for all pollutant monitoring systems
and to explain the approach taken by SAMWG in evaluating existing
or alternative monitoring systems.
At the time this version of the strategy document was printed,
review of the paper "Strategy Issues for Non-Criteria Pollutant
Monitoring" was still in progress. As a result, the recommendations
given here are those which appeared in the original version of this
paper. However, the recommendations reproduced here from the other
seven papers reflect the many comments and discussions offered by
those who were kind enough to review these papers in draft.
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B-2
ISSUES AND RECOMMENDATIONS
FOR "STRATEGIES FOR IMPROVED S02 MONITORING"
ISSUE 1: Should There Be A Change In The Present Structure Of
SOp Ambient Monitoring?
RECOMMENDATIONS:
(1) SAMWG recommends that EPA, in cooperation with State and
local agencies, designate a limited number of fixed SOp National
Air Quality Trend Stations (NAQTS) to be operated indefinitely for
the purpose of analyzing and reporting national and local trends.
These NAQTS would be complemented by additional State and local
air monitoring stations (SLAMS) to provide needed information to
evaluate SO^ NAAQS attainment and progress brought about by air
pollution control and abatement activities. The number of NAQTS
in any specific area would range from 2-8 stations, depending on
S0? concentrations levels and urbanized area population. NAQTS
must meet the following criteria:
(a) have EPA approved continuous SOp analyzers.*
(b) be sited in accordance with EPA guidance and oper-
ated under EPA approved quality assurance procedures.
(2) SAMWG recommends that current SIP monitoring guidance
(40 CFR 51.17) be modified to reflect the need for permanent trend
stations (NAQTS and SLAMS) and to provide additional flexibility
needed at the State and local agency level for monitoring activities
to support SOp control strategy development and evaluation.
(3) SAMWG recommends that EPA increase its efforts to pro-
vide technical and operational guidance in the areas of S0? ambient
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B-3
monitoring network design, recognizing the dynamic monitoring
needs of the SOg monitoring program. The guidance should cover
network size, siting criteria, sampling frequency, quality assur-
ance, data base—as relates to both point source and urban monitor-
ing.
*It is recognized that at least for an interim period, many of
these stations will be using non-continuous methods, especially at
those stations where temperature effects are unimportant and for
which annual averages are of highest concern. SLAMS should be
scheduled for continuous analyzers as needs dictate and resources
allow.
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B-4
ISSUE 2: What Should Be EPA's Policy Regarding The Use And
Interpretation Of SCL Bubbler Data?
RECOMMENDATIONS :
(1) EPA Regional Offices should continue to encourage State
and local air pollution control agencies to evaluate their bubbler
monitors regarding the effect of temperature on reported data.
Where evaluation indicates that bubbler data have been inaccurate,
Regional and State officials should review the status of SOp attain-
ment of NAAQS which may have been influenced by inaccurate bubbler
data.
(2) Bubbler sites which are susceptible to temperature effects
should be:
(a) replaced with equivalent continuous monitoring
instruments
(b) replaced with a modified bubbler operation which
will not be subject to temperature effects
(c) be used to sample only during seasons in those areas
where temperature effects are insignificant, or
(d) be terminated.
The appropriate decision by the Regional Office and State
or local agency should be based on the need for information at the
affected station and the cost of replacing or upgrading the bubbler.
(3) EPA should continue its intensive evaluation of the
bubbler methodology, and as soon as possible either:
(a) modify the procedure so that it can be used under
realistic field conditions, or
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B-5
(b) take the necessary steps to establish a continuous
reference principal and calibration procedure for
ambient SCL.
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B-6
ISSUE 3: Use Of Diffusion Modeling Of S02 Concentrations
RECOMMENDATIONS:
(1) Where modeling is practicable, EPA should encourage the
use of S02 diffusion models to:
(a) augment ambient SO^ networks in areas where SOp NAAQS
are threatened
(b) define emission limitations and regulations in
special cases
(c) estimate air quality increments caused by new sources,
and
(d) design and evaluate S02 air monitoring networks.
(2) EPA should standardize criteria for validation of S02
diffusion models for point sources and urban areas.
(3) EPA should provide increased technical assistance to
States and local agencies wishing to employ standard EPA or other
models for the purposes stated above.
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B-7
ISSUE 4: Increasing Needs For Emission Source Monitoring Data
RECOMMENDATIONS:
(1) SAMWG recommends that State and local agencies complete
baseline S02 emission inventories, with priorities determined by
the severity of the S0« problem in each county.
(2) Baseline S0» inventories should be updated annually by
the appropriate control agency and submitted to EPA for both point*
and area sources.
(3) Detailed emission inventories necessary for dispersion
modeling should be collected by State and local agencies only as
needed. Agencies using diffusion models for development, evalua-
tion, or revision of a SIP should retain the inventory for a period
of time as specified by the EPA Regional Office.
(4) A minimum quality assurance program should be developed
by ORD and implemented by the Regional Offices for source testing
and continuous in-stack monitoring. Particular attention should
be given to provide sufficient training where technical expertise
is lacking.
*SO« sources whose actual SOg emissions exceed 100 tons per year.
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B-8
ISSUES AND RECOMMENDATIONS FOR "STRATEGY ISSUES FOR
IMPROVED SUSPENDED PARTICULATE MONITORING"
ISSUE 1: Should there be a change in the present monitoring net-
works for suspended particulate matter?
RECOMMENDATIONS
1. National Air Quality Trend Stations
Through a cooperative effort between Federal, State, and local
agencies, a minimum number of permanent national air quality trend
sites (NAQTS) should be designated and operated indefinitely. The
data from these stations would be used to analyze and report national,
regional, and local trends. These stations need not be equivalent to
the minimum number of stations currently calculated from 40 CFR 51.17,
but a subgroup of the total.
Stations selected as a NAQTS must use the Federal Reference
Method for suspended particulates and must implement EPA's quality
assurance program for suspended particulates. They should represent
sites which have at least three continuous years of valid data. The
stations must also be located according to the most recent EPA
network design and siting guidance documents. In addition, the
selected stations should meet any one or combination of the following
criteria:
a. represent to the extent possible the maximum concentration
point of an urbanized area greater than 50,000 population. The site
should not be significantly affected by an individual source. In
areas not previously monitored, emission data and modeling should be
used to establish site location.
b. represent an urbanized area which has a population
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B-9
greater than 50,000, is below the secondary standard, and has a high
potential for significant air quality degradation.
c. represent to the extent possible areas of maximum popula-
tion density.
2. State and Local Air Monitoring Stations (SLAMS)
a. The designation of State and local air monitoring stations
(SLAMS) should be through a cooperative effort between the regional
offices and State agencies.
The number of stations in this category would be decided
by the States and regional offices. The SLAMS must use the FRM
and adhere to EPA guidelines on network design and siting, as well
as the quality assurance guidelines.
b. In view of the recently identified TSP station location
deficiencies, a more comprehensive monitoring network for TSP
problem identification should be established in widely dispersed
industrial areas and industrial areas frequently located just
beyond local jurisdictional boundaries. This may require increased
cooperation between state and local agencies.
c. Nonurban background stations should be established to
allow for the measurement of incoming transported TSP pollutants
in special problem areas. This recommendation is also in response
to current TSP station location deficiencies.
3. Special Purpose Monitoring Stations
SAMWG recognizes the numerous State and local demands for
special purpose ambient air monitoring data. Because of the varied
and unique requirements, the States should have prime responsibility
for deciding the number of such stations, location, sampling fre-
quency, length of study, and measurement method.
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Whenever possible, the FRM should be used. In addition, EPA
guidelines on quality assurance and network design and siting should
be followed to the greatest extent.
4. The current SIP air quality surveillance requirements (40
CFR 51.17) should be modified to include:
a. criteria for establishment and operation of national air
quality trend stations, including quality assurance, number and
location of stations, siting specifications, sampling schedule, and
reporting requirements.
b. designation of State and local air monitoring stations
c. provisions which allow the State and local agencies more
flexibility to respond to the variety of special purpose monitoring
associated with the overall goal of attaining, and maintaining,
ambient air quality standards.
ISSUE 2: Are improvements in the FRM for TSP needed?
RECOMMENDATIONS
1. EPA should critically review and evaluate the current FRM
writeup and tighten up the shelter design specification, prescribe
filter specifications, and attempt to clarify and improve the cali-
bration and operation procedures.
2. All NAQTS and SLAMS should use filters conforming to the EPA
specifications. To the extent possible, the special purpose
monitoring stations should also operate with the standardized fil-
ters.
3. EPA should conduct further investigations of the feasibility of
the use of the high-volume sampler in emergency episode situations.
4. EPA should continue its investigations of possible replacement
methods for the FRM. The replacement method should have the
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B-ll
capabilities for continuous or short-term sampling, particle sizing
and retention of sample for retrospect analysis.
ISSUE 3: Should the sampling frequency for TSP be varied or fixed?
RECOMMENDATIONS
On the basis of statistical considerations and the purposes
of the data, SAMWG recommends the following schedules for TSP
monitoring:
1. National Air Quality Trend Stations employ an every-sixth-day
schedule as a minimum. Data obtained from any balanced schedule
with more frequent monitoring is also acceptable. Additional data
that result in an unbalanced schedule are not to be submitted to
EPA but may be used by State and local agencies in combination with
the balanced schedule data sent to EPA to evaluate compliance or
progress at that site.
2. State and Local Air Monitoring Stations employ an every-sixth-day
schedule as a minimum. This basic schedule may be augmented as
required by the State or local agency to ensure sufficiently pre-
cise statements regarding the status or progress of the station.
3. Special Purpose Monitoring Stations may employ any monitoring
schedule that is consistent with the intended use of the data.
ISSUE 4: What are the emission data and modeling needs for improving
TSP control planning technology?
1. EPA should develop better techniques for estimating fugitive
emissions from traditional sources.
2. Improved inventories of fugitive emissions in heavily indus-
trialized particulate problem areas should be conducted.
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B-12
3. State and local agencies should reassess their point source
cut-off points in TSP problem areas to be certain that smaller
sources which may now constitute a major percentage of the tradi-
tional source emissions, are receiving appropriate attention.
4. EPA should develop improved techniques for inventorying emis-
sions from nontraditional sources in urban areas and support their
use by State and local agencies.
5. EPA should develop and provide to the States a diffusion model
which considers particle size, small-scale diffusion, and the
deposition characteristics of emissions from nontraditional urban
activity sources.
6. EPA should continue efforts to develop and document the mechan-
ism of formation and models for the prediction of the secondary
particulate pollutants sulfates and nitrates.
7. EPA should continue to conduct and support research efforts
directed to improve our knowledge and understanding of short- and
long-range transported particulates.
8. EPA should continue its efforts to develop continuous montor-
ing instruments to monitor particulate emissions from industrial
sources. The agency should also support studies to provide the
appropriate data necessary to convert opacity measurements made by
existing continuous monitors into particulate emission rates.
9. EPA should establish quality assurance procedures for calibra-
tion and operation of source continuous monitors.
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B-13
ISSUES AND RECOMMENDATIONS FOR "STRATEGIES
FOR IMPROVED CO MONITORING"
ISSUE 1; Should there be a change in the Present Structure in
CO Ambient Monitoring?
RECOMMENDATIONS
1. SAMWG recommends that a limited number of National Air Quality
Trend Stations (NAQTS) be established in each urban problem area.
A problem area is defined as:
a. any urbanized area greater than 500,000 population
b. any area where a TCP is in effect or under development
for CO
c. any area where measured air quality from monitors sited
according to current guidance is not expected to reach
the NAAQS by 1980 based on the projected emission improve-
ments of the Federal Motor Vehicle Control Program.
2. SAMWG recognizes the possible need for additional State and
local CO air monitoring stations (SLAMS) in addition to the NAQTS
in the areas which meet the criteria of recommendation one.
3. SAMWG recommends that special purpose monitoring be performed
to validate the suitability of permanent NAQTS or SLAMS locations
for determining maximum and neighborhood air quality levels, to
demonstrate or derive relationships of the permanent monitoring
stations data to population exposure, to provide additional data
in support of SIP control strategies, and to determine spatial
distributions of CO air quality. Further, it is recommended
that special purpose monitoring be done periodically in urban
areas which do not have permanent monitoring stations to assure
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B-14
that standards are being attained. If significant CO problems
are uncovered, then a permanent station could be installed.
Reference methods should be used where possible; however, grab
or bag sampling and analyzers using electrochemical principals
would be acceptable procedures for special studies.
4. The NAQTS should be operated in each of two locations,
i.e., in areas of maximum pollutant concentration and in high
density population neighborhoods. The sites should be standardized
in terms of instrumentation, (reference methods or equivalent
should be used), probe siting and quality assurance practices.
Once established, the sites should not be moved so that a trend
data base can be established.
5. SAMWG recommends that current SIP Monitoring Requirements
(40 CFR 51.17) for CO be amended to allow the State and local
agency to determine the need for and quantity of CO monitoring
based on the criteria in recommendation one.
6. Standardized monitor siting criteria should be established
for locating CO monitors. These criteria should include the
general types of areas to be monitored, as well as the specific
probe location at a site. These criteria should be followed by
all involved with CO monitoring in support of SIP's so that a
standardized, comparable data base is obtained.
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B-15
ISSUE 2: Increasing Need for CO Air Quality Models
RECOMMENDATIONS
1. CO diffusion models should be used to estimate the impacts
of increased CO levels from new and indirect sources.
2. EPA should standardize the validation procedure for CO
diffusion modeling and provide guidelines and technical assistance
to State and local agencies wishing to employ validated EPA or
other models for use in predicting hot spot locations.
3. Greater emphasis should be placed on using validated models
to estimate maximum CO levels at representative types of congested
traffic areas for developing and evaluating control strategies.
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B-16
ISSUE 3: Needs for Emissions and Source Monitoring Data
RECOMMENDATIONS
1. Baseline CO emission inventories should be completed for each
county where National Air Quality Trend Stations are located
or where SIP revisions are to be made. Local planning and
transportation agencies should be consulted since they can
usually provide most of the source data needed to make the
emission estimates. Supplement 5 to AP-42, "Compilation of Air
Pollutant Emission Factors" should be the source of all emission
factors used in the baseline inventory.
2. Baseline CO inventories should be reviewed and updated
annually by the appropriate control agency.
3. Detailed inventories necessary for control strategy
analysis should be collected only as needed, but once begun
should be updated annually for strategy evaluation. AP-42
can be used as the basis for emission calculations. However,
SAMWG encourages control agencies to conduct a more extensive
analysis of source characteristics in a specific area (especially
near monitoring sites) since the factors in AP-42 are based on
a national average.
4. Control agencies should collect traffic flow information
and percent of vehicles by driving mode around CO monitoring
sites if such information is available from planning or trans-
portation agencies. The sites whose air quality data form the
basis for SIP revisions should be done first. It would not
be necessary to collect the information on a continuous basis,
but rather over a short time period sufficient to establish the
traffic flow patterns and vehicle mix.
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ISSUES AND RECOMMENDATIONS FOR
"STRATEGY FOR IMPROVED N02 MONITORING"
ISSUE fl: Should Any Changes Be Made In The Ambient Monitoring
Structure for N02?
RECOMMENDATIONS
1. EPA, in cooperation with State and local agencies, should
designate fixed N02 National Air Quality Trend Stations (NAQTS)
to be operated for an indefinite period for determining progress
toward achieving or maintaining NAAQS. Reference or equivalent,
continuous methods should be used at these sites, to the extent
practicable. These stations should be located in urbanized areas
expected to experience concentrations near, or in excess of, ambient
standards. It is expected that no more than two to four NAQTS
would be needed in most major metropolitan areas. Only a few
larger metropolitan areas with widespread, high N02 levels would
need to designate a larger number of NAQTS sites.
2. Current SIP monitoring guidance (40 CFR 51.17) should be
modified to reflect the prescribed criteria for fixed N02 NAQTS,
and to provide additional flexibility, possibly including criteria
for supplementary fixed or movable stations as needed by the State
and local agencies for N02 and also oxidant control strategy
development and evaluation. These criteria should consider current
agency capabilities and resources.
3. EPA should provide additional technical guidance to State and
local agencies regarding minimum, adequate network size, siting
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B-18
criteria, sampling frequency, quality assurance, data base, etc.
needed to assess ambient NCL levels relative to achievement/main-
tenance of the N02 NAAQS and state standards.
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ISSUE #2: Relating Nitrogen Oxides (NO ) Emissions and Ambient
A
N02 Levels.
RECOMMENDATIONS
1. SAMWG recognizes that rollback models are the most practical
models now available for developing and evaluating NO control
A
strategies to achieve ML ambient air standards. However, rollback
models may over-simplify the relation of NO emissions to N0? air
A C-
quality, while more sophisticated simulation models are presently
too intricate, resource consuming, or have limited applicability.
Therefore, EPA should vigorously pursue the development and evalu-
ation of alternative simulation models and/or empirical-statistical
modeling techniques to project ambient N02 concentrations. Such
improved models would also have application in designing NOp moni-
toring networks and complementing existing monitoring data.
2. The rollback or modified rollback model should continue to be
used as the principal tool for developing NO emissions control
A
strategies until better models are developed and evaluated. How-
ever, use of current diffusion/photochemical models is encouraged
in special cases or localities where resources for their application
is available and their superiority over rollback techniques in
developing workable strategies is indicated.
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B-20
ISSUE #3: What Are The Needs For Nitrogen Oxides (NO ) Emission
A
Data, and What Changes Should Be Made In The Acquisition
of These Data?
RECOMMENDATIONS
1. State and local agencies should complete baseline (listed in
Table 4) NO emission inventories by county in areas threatening
A
or violating ambient N09 standards. If baseline NO emissions
£ /\
data are needed in other state areas, EPA can develop the inven-
tory data by national apportioning, unless the State or local air
pollution control agencies decide to collect these data themselves.
However, in any areas where State/local agencies do not complete
baseline emission inventories, SAMWG recommends that they still
collect the baseline data for these point sources emitting more
than 100 tons/year of NO .
/\
2. Baseline NO emission inventories compiled by State and local
A
agencies should be updated, on a calendar year basis, by the
appropriate control agencies and the updated data submitted to EPA.
For control strategy development and trends purposes, a record
should be retained by EPA or State/local agencies of emission
inventories applicable to individual years. (An annual record of
emissions data would allow an evaluation of the relationship be-
tween NO emissions trends and N09 air quality trends, and thus an
A £
assessment of the effectiveness of control programs.) (See also
Chapter VII recommendations on data reporting and handling.)
3. Detailed emission inventory data for simulation modeling
purposes beyond annual baseline needs should be collected by State
-------
B-21
and local agencies only as needed. These data should be retained
for a reasonable period for possible recurring modeling needs.
The period of retention should be coordinated with the appropriate
EPA Regional Office.
-------
B-22
ISSUES AND RECOMMENDATIONS FOR
"STRATEGIES FOR IMPROVED OXIDANT AND HYDROCARBON MONITORING"
ISSUE 1: Should measurement techniques for hydrocarbons and oxi-
dants be changed?
RECOMMENDATIONS
SAMWG recommends that EPA begin a study to determine whether
the FID NMHC analyzer is a satisfactory surrogate measurement for
ambient organic carbon. If it is not, then EPA should immediately
begin the development of a non-methane organic carbon (NMOC)
analyzer.
ISSUE 2: What kind of oxidant monitoring networks are needed?
RECOMMENDATIONS
1. SAMWG recommends that a national air quality trend station net-
work (NAQTS) for oxidants be established according to the location
criteria for NAQTS. NAQTS must use a Federal Reference Method
or equivalent and must operate in conformance with EPA's quality
assurance program.
2. States and local agencies, in collaboration with the EPA
regional offices, should examine their local oxidant networks and
redesign them, if necessary, to better assess the regional oxidant
problem. Statewide, and even interstate, planning should be under-
taken in order to make most efficient use of present equipment.
3. State and local agencies should mount a monitoring program in
appropriate areas, the purpose of which would be to learn of the
local relationship between emissions and ambient levels of NMOC,
NO , and oxidants and to determine which type of model (upper en-
A
velope curve, statistical, or photochemical diffusion) is the most
appropriate for their special local use.
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B-23
ISSUE 3; What should be done about Improving organic compound
emission Inventories?
RECOMMENDATIONS
1. SAMWG recommends that EPA, 1n collaboration with state and local
agencies, should agree upon a procedure for compiling base-line
inventories of oxidant precursors. All agencies should follow the
same procedure so that inventories from all areas can be compared
on a common basis.
2. State and local agencies having oxidant problems should
initiate compilation of their NMOC inventories as soon as a satis-
factory procedure is available. The agencies should make every
effort to keep the Inventories current.
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B-24
ISSUES AND RECOMMENDATIONS OF TAPE
SAMPLER MONITORING ISSUES PAPER
ISSUES:
There are four issues:
1. The Number of Samplers Needed: If an area is not prone
to episodes, should tape sampler monitoring be continued? If an
area is prone to episodes, should the level of monitoring be
continued or would a reduced number be adequate?
2. The Frequency At Which These Samplers Should Be Operated:
Should samplers be operated all year, even if episodes are known
to occur only during a short time during the year?
3. Reporting of Data to EPA: Should data be reported to
EPA that have only marginal or no use? What type of data are
needed at each organizational level?
4. Alternative Monitoring Techniques: Should other
monitoring techniques be used in place of tape samplers to
collect the necessary information for activating emergency
episode procedures?
RECOMMENDATIONS:
1. Eliminate all tape sampler monitoring in areas that do not
experience or are not prone to episodes.
2. Retain at least one tape sampler in areas experiencing
episodes or prone to emergency episodes. Staggered 24 hour
high volume sampling could be used instead of tape samplers.
It may be necessary to monitor at more than one site in an
area especially if more than one control agency is involved or
if several areas of high emissions from individual sources exist.
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B-25
3. Operate the additional samplers only when episodes occurred.
This could be achieved by using air stagnation advisories (ASA)
as a triggering mechanism to operate the instruments, by running
one tape sampler all year, or if TSP high volume measurements
675 ug/m (24-hr only). (Operation of all samplers year round
would also be acceptable.)
4. Areas experiencing high TSP concentrations due to natural
fugitive dust would not need to monitor.
5. Only summary type information would be sent to EPA.
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B-26
ISSUES AND RECOMMENDATIONS FOR
"STRATEGIES FOR POINT SOURCE MONITORING"
ISSUE #1: Should EPA Require Significant Emissions Point Sources
to Have Permanent Point Source Monitoring (PSM)* Programs?
RECOMMENDATIONS
1. Point sources should not be required to establish permanent
full-scale PSM programs to continually assess environmental impact
due to high resource requirements. However, air pollution control
agencies at all levels should examine the advantages of more limited
PSM requirements such as submission of fuel analysis data by power
generation sources and process feed data by other categories of
sources as a compliance monitoring tool.
2. All air pollution control agencies should increasingly require
PSM as necessary to support specific program needs, and to be used
as a more effective enforcement and program implementation tool.
A form of PSM with stipulated scope should be required for sources
subject to new source review where prevention of significant deterio-
ration is an issue.
3. EPA program offices should assist RO's and State and local
agencies, in the form of technical support documents in conduct of
programs where PSM may be required. Generally, discretion and
flexibility to apply PSM requirements should rest with RO's or State
and local agencies except for requirements specifically regulated,
such as continuous source emission monitoring.
*Point Source Monitoring includes: ambient monitoring
around a source, manual source tests, continuous in-stock monitor-
ing, fuel analyses, and dispersion modeling.
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B-27
ISSUE #2; What Should be the Scope of PSM Activities When They Are
Conducted?
RECOMMENDATIONS
1. EPA Headquarters program offices should assist RO's and State/
local agencies by defining the PSM data needs required for specific
program area. The spectrum of PSM activities needed to furnish
these data should also be defined.
2. EPA should strengthen program efforts, to ensure that valid,
reliable PSM techniques are available, and can be conducted cost
effectively.
ISSUE #3: Who Should Conduct PSM Programs?
RECOMMENDATIONS
1. The burden of conducting and paying for point source monitor-
ing should be placed on the responsible source. Factors such as
cost of monitoring, sensitive litigation, and special studies may
mitigate this rule. This decision should be made by the appro-
priate control agency official on a case-by-case basis.
• . j
2. The control agency should provide an overview of PSM programs
developed by sources. Appropriate review and concurrence of
proposed PSM programs, with final acceptance being based on how
effectively the proposed PSM will satisfy pertinent program require-
ments, should be an integral part of this overview activity. Appro-
priate resources must, therefore, be programmed to ensure the
adequacy of PSM data.
3. Quality assurance procedures for conduct of PSM activities should
be established. Acceptance of source-generated PSM data should be
premised on use of standardized QA procedures. EPA should provide
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B-28
appropriate technical assistance to State and local agencies
relating QA procedures.
ISSUE #4: How Should Point Source Monitoring Data be Controlled
and Reported?
RECOMMENDATIONS
1. Raw data from PSM activities should not be submitted to EPA on
a routine basis since quarterly excess emission reports, along with
program mandated source inspections provide an adequate enforcement
system.
2. A national clearinghouse should be established to collect and
store pertinent information related to each PSM activity conducted
in order to centralize and facilitate dissemination of information
concerning PSM activities.
3. Continuous in-stack monitoring requirements should continue to
be set for all major sources when feasible. Consideration should
also be given to requirements for monitoring and reporting of
process feed data such as fuel sulfur content or other relevant
parameters which can provide an indication of a source's compliance
status. SAMWG considers this high priority inasmuch as the data is
essential to ensure continuing source compliance and is a very use-
ful component of PSM systems conducted for various program purposes.
Similarly, high priority should also be given by EPA to the develop-
ment and improvement of continuous monitoring instruments for all
major categories of sources and all regulated pollutants. It is
specifically recommended that continuous monitoring instruments or
other techniques be developed to monitor particulate emissions
from industrial sources or alternately, to convert opacity measure-
ments made by existing continuous monitors into particulate emission
-------
B-29
rates. EPA should also continue efforts to develop remote source
and long path monitoring techniques to be used as adjuncts to PSM
systems.
4. That EPA continue to establish QA procedures and techniques for
validating the accuracy of data produced by source continuous
monitors. This will ensure that the adequacy of such data sub-
mitted to control agencies as part of emission monitoring regula-
tions or as part of other PSM requirements imposed by control
agencies.
5. Manual source testing should continue to be a case-by-case
decision to be made by the responsible control official whether it
is to be required solely or as part of a more comprehensive PSM
system. Data from these tests should, however, be retained and
available through cross-referencing from the PSM National clearing-
house discussed herein. Data from these tests should be available
on a national basis to all cognizant control agencies, and to indus-
try sources, subject to confidentially restriction.
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B-30
ISSUES AND RECOMMENDATIONS FOR
"STRATEGIES FOR NON-CRITERIA POLLUTANT MONITORING"
ISSUE #1: Is there a need for functional direction of non-criteria
pollutant monitoring? If so, what should be considered
in the operational aspects of the program?
RECOMMENDATIONS
1. As is the case with criteria pollutants, EPA should charge a
group with responsibility to provide direction to operational non-
criteria pollutant monitoring. It is essential that this activity
be closely coordinated with and use the results of EPA's ongoing
research activities, quality assurance, methods standardization,
and criteria pollutants equivalency programs.
2. EPA should assemble, in an Agency-wide effort, a priority list
of pollutants for monitoring methods development. Health and wel-
fare effects should be of primary concern.
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B-31
ISSUE #2: What actions should be taken to quickly respond to the
needs for non-criteria pollutant monitoring when stan-
dard methods are not available?
RECOMMENDATION
1. The responsibility and resources for evaluating and recommending
state-of-the-art monitoring methods for non-criteria pollutants
should be assigned to * specific program within EPA which would
conduct both laboratory evaluation and field testing. It is
essential that these activities be closely coordinated with EPA's
existing field monitoring and quality assurance activities.
-------
B-32
ISSUE #3: What effort should be taken to meet the growing needs
for baseline non-criteria pollutant data?
RECOMMENDATION
1. EPA should continue and expand its program of monitoring for
priority non-criteria pollutants in various urban atmospheres and
other appropriate locations.
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B-33
ISSUE #4: How can the exchange of non-criteria pollutant monitoring
information be accomplished?
RECOMMENDATION
1. EPA should establish a central information point for collecting
and disseminating information about non-criteria pollutant monitor-
ing projects. This would include projects by State and local
agencies, private firms, and other Federal organizations.
-------
APPENDIX C
INTRODUCTION
The purpose of this Appendix is to provide additional in-
formation on the design of the NAQTS and SLAMS networks and to
provide guidance for the siting of monitoring instruments. The
Appendix is divided into four parts:
1. Design of NAQTS Including Statistical Considerations
2. Siting for NAQTS
3. Additional Considerations in Siting SLAMS
4. Probe Siting Criteria for NAQTS and SLAMS
It should be recognized in designing the SLAMS and NAQTS net-
works, that a site designated as a NAQTS for one pollutant could
be designated as a SLAMS for other pollutants; e.g., an S02 NAQTS
site could have SLAMS monitoring collocated for TSP, N02 or 03-
Special purpose monitoring is not covered in this Appendix
because in most cases the location of the monitors and siting of
instrument probes is dependent on the purpose of the study. The
probe siting criteria in Part 4 to this Appendix should be
followed to the extent possible if the usefulness of the air
quality data will be compromised.
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C-2
PART 1: DESIGN OF NAQTS INCLUDING STATISTICAL CONSIDERATIONS
SOp and TSP NAQTS Criteria
Generally, it is desirable to have a larger number of NAQTS
in the more polluted and densely populated urban and multi-source
areas. Table C-l and C-2 indicate the approximate number of
permanent monitors believed to be needed in urban areas to charac-
terize national and regional TSP and S02 air quality trends and
geographical patterns. The criteria require that the number of
stations vary from a high of approximately 6 to 8 in areas
where urban populations exceed 500,000 and concentrations exceed
primary NAAQS, down to as few as one or two (or none) in smaller
urban areas where the S02 or TSB problem is minor. The actual
number of stations and their location will be decided by negotiation
between EPA and the State agency.
Generally, the "worst" air quality in an urban area should be
used as the basis for control strategies. This may, however, exclude
air quality levels caused predominately by single point source
emissions (e.g. remote power plants or smelters).
To estimate the number of urban areas which would meet the criteria
shown in Table C-l and C-2, pollutant concentration data from SAROAD
were used.
To guarantee a reasonable geographical balance, SAMWG recommends
that at least one TSP and S02 NAQTS be established in each state.
Without this requirement, it is conceivable that many states would
have no TSP or S02 NAQTS and this would create an undesirable
data gap. Where not otherwise indicated, this NAQTS would be located
-------
C-3
in the largest urban area or the heaviest industrial area.
The estimated number of TSP monitors which would be required
in the NAQTS network ranges from approximately 500 to 1000. The
actual number of monitors in any specific area would depend on
local factors such as meteorology, topography, urban and regional
air quality gradients, and the potential for significant air
quality improvement or degradation. Generally, the greatest
density of stations would occur in the northeastern states,
where urban populations are large and where pollutant levels
are high. Fewer monitors are necessary in western states,
especially for SOp, since concentrations are seldom above the
NAAQS in urban areas. Exceptions to this will occur, however,
in areas where an expected shortage of clean fuels indicates
that ambient air quality may be degraded by increased S02 emissions.
In such cases, a minimum number of national trend stations is
desirable to provide EPA with a proper national perspective
on any changes.
CO NAQTS Criteria
EPA Headquarters needs information on ambient CO levels
in major urbanized areas where CO levels have been shown, or
inferred to be of significant concern. At the national level,
EPA will not routinely require data from as many monitors as
are required for TSP, and, perhaps S02 , since CO trend stations
are designed to monitor the overall progress of the emission con-
trols required by the Federal Motor Vehicle Control Program
(FMVCP).
-------
C-4
Although State and local air programs may well require exten-
sive monitoring to document and measure the local impacts of CO
emissions and emission controls, an adequate national perspective
is possible with as few as two monitors per major urban area. As
described in the main text, the two types of situations which would
require CO NAQTS are: (1) peak concentations areas such as are
found around major traffic arteries and near heavily travelled
streets in downtown areas (such areas are measured in what is
referred to as middle scale—i.e., tens to hundreds of meters);
and (2) neighborhoods where concentration exposures are significant.
Peak concentration sites will generally be strongly influenced by
local sources such as heavy automotive traffic, while neighborhood
sites more generally reflect the combined impact of all vehicular
sources in the urban area. Neighborhood sites are generally more
suitable for ascertaining trends and exposures to CO over wide-
spread portions of urban areas, while peak CO concentration sites
more adequately characterize "worst" conditions within local areas.
(In addition to data from these two types of area, EPA requires
information from a minimum of one station in a small subset of
the urban areas requiring transportation control plans. Such
information is needed to document the ambient effects of major
shifts in commuting patters brought about by the TCP's and/or
other factors.)
-------
C-5
Because CO is generally associated with heavy traffic and
population clusters, urban population is the principal criterion
for identifying candidate urban areas for which pairs of NAQTS
for this pollutant will be required to meet the needs described
above. In addition, areas where CO ambient levels are known to
be a problem will also be required to maintain NAQTS. The
following specific criteria will be applied in locating and
selecting candidate areas for placing pairs of permanent CO
trend stations
(a) Any urbanized area greater than 500,000** population
(b) Any area where a TCP is in effect or under development
for CO, and;
(c) Any area where air quality measured by monitors sited
according to current guidance is not expected to reach
the NAAQS by 1980 on the basis of projected emission
reductions from the Federal Motor Vehicle Control
Program.
Table C-3 presents a national summary of areas following
under criteria listed above, according to information available
from the U.S. Census, and air quality data stored in the NADB.
This strategy will require approximately 77 urban areas to
operate paired CO monitoring stations on a permanent basis. A
total of 11 urban areas will need to install additional CO in-
struments, either because no CO monitoring is now taking place,
** On the basis of routine data and various special purpose
monitoring efforts, it is thought that these areas have, or
will have CO concentrations well above the NAAQS.
-------
C-6
or because only one monitor is in operation.
Nationally, approximately 450 CO monitors are now known
to be in operation. The total number of permanent trend CO
stations under this strategy is approximately 154, which is less
than 35 percent of the total number of stations now operating.
Most (66) of these urban areas currently have at least a pair
of CO monitors. The major impact of this strategy will be in
the effort required of the State and local agencies in evaluating
and possibly relocating existing CO stations to be consistent
with EPA location criteria.
NO., NAQTS Criteria
From a national perspective, the current f^ ambient air
quality problem is not as extensive or ,as severe as with other
pollutants. Accordingly, the need for an extensive NAQTS
network is not as great. It is estimated that there are approxi-
mately 30 areas in the country which have, or may have, a potential
problem in meeting the NOp NAAQS over the next 5 years. These
areas will definately have one or more NAQTS.
In addition, urban areas where population exceeds 1,000,000
should have permanent trend stations because of the general
association (See Table C-4) between population and high annual
average N0? levels, and also to assure appropriate representation
of populous areas. In 1974 data from SAROAD, over half of the
25 urban areas above 1,000,000 showed annual NO^ averages in
excess of 75 yg/m3.
-------
C-7
Listed below are the criteria for choosing candidate urban
areas for N02 NAQTS:
(a) Any urbanized area which does not meet or only marginally*
meets the annual NAAQS for N02 100 yg/m , annual arith-
metic mean (measured or estimated);
(b) Any urbanized area that clearly meets the NOp annual
NAAQS but is projected to not .meet the annual NAAQS by
1980. Such urbanized areas would be those which have annual
NOp levels at or above 75 yg/m , but less than 100 yg/m -
annual arithmetic mean (measured or estimated). This
assumes a projected growth rate of NO emissions of
A
about 5 percent per year. Other local emission growth
rates or NO emission reductions may be substituted to
/\
project 1980 levels;
(c) Any urbanized area not currently being monitored where
the urban population exceeds 1,000,000**;
(d) At a later date, if a short-term standard should be
set, additional areas may need to be added, depending
on the value of the short-term NAAQS and projections
for meeting the standard by 1980.
Using the criteria recommended above, and air quality data from SAROAD,
the approximate number of urbanized areas expected to have NAQTS are shown
in Table O5. Within urban areas requiring NAQTS * a range of from 2 to 4
*within 10* of Standard
**over 50% of those areas now monitoring show annual average exceed-
o
ing 75 yg/m . Future growth and growing concern over peak N02
concentration effects will necessitate national assessments for these
areas.
-------
C<-8
permanent monitors is sufficient. The actual number in any
specific urban area depends on local factors such as area size,
the magnitude of the NCL problem* the number of significant NCL
"hot spots" projected rates of growth, meteorological factors
favorable to NCL formation, and topography. Nationally, this
strategy will result in a range df approximately 75 to 150 NO^
monitors. These numbers are to be compared with a national
total of approximately 1000 stations where NOp monitoring is now
conducted.
Ozone NAQTS Criteria
A current survey of oxidant monitoring shows that about
500 monitors are now operating and reporting data to EPA. Of
these, three-fourths have had one or more hours in excess of
the NAAQS.
SAMWG believes that accurate national assessments of ozone
concentrations and trends can be outlined with somewhat fewer
stations. After reviewing the existing monitoring station
distribution and ambient concentration levels throughout the
country, SAMWG believes that adequate ozone data can be obtained
with around 170 to 200 ozone monitors. Criteria for selecting
(or establishing, if necessary) NAQTS are as follows:
(1) Any urbanized area having a population of more than
250,000 and which exceeded the oxidant NAAQS at any
time in the past 3 years; and
(2) Any area (AQCR or urban place) where oxidant concentra-
tions are definitely a problem related to urbanization.
-------
C-9
The first criterion, thus, is essentially population oriented
and will include those relatively highly populated areas where
most of the oxidant precursors originate, while the second criterion
will pick up those additional areas where there is definitely an
oxidant problem related to urban emissions (most probably due to
transported oxidant or precursors). Table C-4 gives the number
of areas which fit these two criteria.
Each urban area will generally require only two national
ozone trend monitoring stations. These stations should generally
be located downwind of the urban core according to predominant
summer/fall daytime wind patterns. The exact location would
depend on local factors affecting the transport and accumulation
of peak 03 levels; however, the locations should be balanced by
the need to represent population exposure to ozone.
-------
TABLE C-]
TSP NATIONAL AIR QUALITY TREND STATION CRITERIA
ESTIMATED NUMBER OF URBAN AREAS (Approximate Number of Stations Per Area^
Population Category
High Population
> 500,000
Medium Population
100,000-500,000
Low Population
50,000-100,000
TOTALS
High Cone/1)
29 (6-8)
35 (4-6)
14 (2-4)
78
Med. Conc.^
15 (4-6)
51 (2-4)
27 (1-2)
93
(2)
Low Cone. '
2 (0-2)
39 (0-2)
31 (0)
72
Totals
46
126
76
248
o
o
(DlH
(2)
(3)
High. Cone. - Exceeding Primary NAAQS by 20% or More
Med. Cone. - Exceeding Secondary NAAQS
Low Cone. - Less than Secondary NAAQS
TOTAL STATIONS NATIONWIDE: 531 to 928 (Note: It is desirable that every state be represented
by at least one TSP monitor)
Selection of urban areas and actual number of stations per area will be decided by
negotiation between EPA and State agency.
-------
TABLE C-2
S02 NATIONAL AIR QUALITY TREND STATION CRITERIA
ESTIMATED NUMBER OF URBAN^1 AREAS (Approximate Number of Stations Per Area)4
Population Category
High Population
> 500,000
Medium Population
100,000-500,000
Low Population
50,000-100,000
TOTALS
High Conc.(1)
5 (6-8)
4 (4-6)
0 (2-4)
9
Med. Conc.(2)
16 (4-6)
12 (2-4)
5 (1-2)
33
(3)
Low Cone. v '
24 (0-2)
94 (0-2)
52 (0)
170
Unknown
Status
1
16
19
36
!
Total
46
126
76
248
o
(2)
(3),
Cone. - Exceeding Primary NAAQS
Med. Cone. - Exceeds 60% of Primary or Secondary NAAQS
'Low Cone. - Less than 60% of Primary or Secondary NAAQS
TOTAL STATIONS NATIONWIDE: 139 to 454 (Note: It is desirable that each State be represented
by at least one S02 monitor)
(^Selection of urban areas and actual number of stations per area will be decided by
negotiation between EPA and State agency.
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C-12
TABLE C-3
NATIONAL SUMMARY OF CO NAQTS
Estimated*
Criteria for Number of Urbanized Areas
Selection Meeting Criteria
Population greater
than 500,000 46
TCP in Effect or
Under Development 31
Not Expected to
Meet Standards "
by 1980 25
*Actual urbanized areas having CO NAQTS negotiated between EPA and
air pollution control agency.
-------
TABLE C-4
NO ANNUAL MEANS
(1974)
*
BY URBAN POPULATION
Urbanized Areas
> 1,000,000
500,000 -
1,000,000
< 500,000
TOTAL
- 100
5
1
0
6
75-100
8
5
2
15
75
12
12
108
132
No
Suitable
Data
—
3
92
95
Total
25
21
202
248
o
I
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C-14
TABLE C-5
NATIONAL SUMMARY OF N02 NAQTS
Criteria for
Selection
Estimated*
# of Urbanized Areas
Meeting Criteria
Areas not meeting or only
marginally meeting NAAQS
16
Areas that meet NAAQS now
but may not by 1980
14
Areas greater than 1,000,000
population not included above
*Actual urbanized areas having N02 NAQTS negotiated between EPA
and air pollution control agencies.
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C-15
TABLE C-6
NATIONAL SUMMARY OF 0, NAQTS
Criteria for
Selection
Estimated*
# of Urbanized Areas
Meeting Criteria
Urbanized area > 250, 000
population which exceeded
oxidant NAAQS anytime over
last 3 years
80
Any area where oxidant
concentrations are an urban
related problem (not meeting
above criterion)
*Actual urbanized areas having
air pollution control agencies.
NAQTS negotiated between EPA and
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C-16
STATISTICAL CONSIDERATIONS IN THE DESIGN OF THE NAQTS NETWORK
The purpose of this section is to provide background material
concerning the number of sites in the NAQTS network as related
to the probability of detecting trends. As a general rule, the
more sites in the network the better the chance of detecting a
trend. Also, the greater the trend rate the easier it is to
detect a trend. While these general notions are correct, they
are also simplistic, and it is useful to attempt to quantify
some of these relationships. Although this requires certain
assumptions that are somewhat arbitrary, the basic results still
provide a relative indication of the impact of network size on
trend assessment.
Perhaps the most logical place to begin a discussion of
network size and trend assessment is to consider available
historical data. The most recent EPA trends report presents
nationwide TSP trends for the past five years based upon data
from approximately 2000 sites. Instead of using all 2000 sites,
it is possible to choose every fourth site in each region and
use this subset of 500 sites to depict trends. When this was
done, there was virtually no difference in the trend graphs. In
fact, as shown in Figure C-3, a cumulative frequency distribution
of the means of the subset of 500 sites for 1975 is almost in-
distinguishable from that for all 2000 sites. This suggests
that for practical purposes, the same trends could have been
determined from a much smaller network. The obvious question,
though, is "how much smaller?"
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C-17
Theoretically, this question can be examined statistically
to provide an answer. If the variability of the data is known,
it is possible to compute the probability of detecting certain
rates of change over a specific number of years for various
network sizes. Table C-7 shows these results for two-, three-,
and five-year periods. However, it should be recalled that this
table is based on an assumption as to the variability of the
data, which in this case, is the annual mean air quality at a
site. For this discussion, it was assumed that the variability
is +20%, i.e., a 95 percent confidence interval around the annual
mean would be +20%. For those familiar with this type of table,
it may be mentioned that it was computed using power curves for
two-sided t-tests at the 95 percent level for two means or for
the slope of regression equation.
The assumption of +20% variability, although somewhat
arbitrary, may be regarded as a "ballpark" figure. The sampling
error from an every-sixth-day schedule would be roughly +10%,
and so an overall variability of +20% may be regarded as a
reasonable approximation for this discussion.
From this table, a maximum network size of 1000 sites on
the national level seems reasonable. A minimum size of 500 also
appears acceptable. In the case of TSP, however, it is unlikely
that the same rate of change would apply throughout the nation.
Regional differences in the TSP problem make it essential that
the network also be useful for regional trend assessment. In
most practical applications, trends will be assessed on the
-------
C-T8
basis of 3 to 5 years of data to minimize the impact of meteoro-
logical influences. With 50 to 100 sites in each geographical
region, there is a reasonably good change of detecting three-year
trends of more than 2 percent per year.
Using the allocation indicated for a TSP trend network of
500-1000 sites, there would be a reasonable chance of determining
5-year trends of more than 3 percent per year in the medium pop-
ulation 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. So the overall range of 500-1000 NAQTS TSP monitors
seems to be acceptable for the purposes of national and regional
trends, and does not appear to be too dense a network.
It should be noted that this table does not imply that
the cause of the change or trend is known. For example, a 2-year
change of 5 percent may, in fact, be due solely to meteorology
with no change in emissions. There are various ways to minimize
this potential problem. One way is to attempt to adjust the
data for meteorology prior to any trend determination. Another
way is to use several years of data and hope thit the meteoro-
logical influence is averaged out. In actual practice, a little
bit of both approaches is usually employed, but until meteoro-
logical adjustments become more routine, extreme caution should
be used for any air quality trend determined from two years of
data.
The previous discussion has concentrated on trend assessment
for TSP. In principle the same basic tables might apply for
trends in other pollutants but there are certain practical
-------
C-19
differneces that permit smaller networks for these other pollutants.
These points will be discussed briefly. To a certain degree,
the arguments are somewhat heuristic, but are sufficient to
indicate the thinking involved in recommending smaller NAQTS
networks in these cases.
For sulfur dioxide, there are two points worth noting.
First, there are more urban areas with low SCL levels than
with low TSP levels (170 versus 72). Secondly, background is
higher for TSP than SC^. As a consequence, air quality is
more sensitive to SOp emission changes than is the case with
TSP. For example, a 2 percent reduction in TSP emissions from
traditional sources might yield a 1 percent reduction in ambient
TSP levels while a 2 percent reduction in SO emissions might
/\
yield a 2 percent improvement in air quality. With these con-
siderations in mind, a NAQTS network for SOp of 150-500 sites
may sufice.
NOp, CO, and 0- may be considered automotive-related pol-
lutants. For these pollutants the FMVCP results in controls
primarily on the national level, although there are areas with
additional control programs. However, this causes the primary
focus on trends to be national in scope and there is not as
much emphasis on differentiating regional trends. This makes
it possible to use fewer sites and to concentrate primarily on
areas with known or potential problems.
-------
C-20
TABLE C-7
PROBABILITY OF DETECTING CHANGE OVER 2 YEARS
Number
of Sites
3
5
10
25
50
100
200
500
1000
.01
.03
.04
.04
.05
.07
.11
.17
.35
.61
.02
.04
.05
.07
.11
.17
.29
.52
.89
.99
PROBABILITY OF
Number
of Sites
3
5
10
25
50
100
200
500
1000
2000
.01
.04
.05
.07
.11
.17
.29
.52
.89
.99
1.00
.02
.07
.09
.14
.29
.52
.81
.98
1.00
1.00
1.00
Annual Rate
.03 .04
.06
.07
.10
.18
.32
.56
.85
1.00
1.00
.07
.09
.14
.29
.52
.81
.98
1.00
1.00
of Change
.05 .10
.09 .23
.12 .35
.20 .61
.42 .94
.71 1.00
.94 1.00
1 . 00 1 . 00
1.00 1.00
1.00 1.00
.20
.59
.89
.99
1.00
1.00
1.00
1.00
1.00
1.00
DETECTING CHANGE OVER 3 YEARS
Annual Rate
.03 .04
.11
.15
,27
.56
.85
.99
1.00
1.00
1.00
1.00
.10
.24
.43
.81
.98
1.00
1.00
1.00
1.00
1.00
of Change
.05 .10
.23 .69
.35 .89
.61 .99
.94 1.00
1.00 1.00
1.00 1.00
1.00 1.00
1.00 1.00
1.00 1.00
1.00 1.00
.20
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
-------
C-21
TABLE C-7 (continued)
PROBABILITY OF DETECTING CHANGE OVER 5 YEARS
Number
of Sites
3
5
10
25
50
100
200
500
1000
2000
.01
.08
.11
.17
.35
.61
.89
.99
1.00
15.00
1.00
1
1
1
1
1
Annual
.02 .03 .04
.19 .38 .59
.29 .56 .81
.52 .85 .98
.89
.99
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00 1.00
.00 1.00
Rate
•
•
•
1.
1.
1.
1.
1.
1.
1.
1.
of Change
05 .10
78
94
00
00
00
00
00
00
00
00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.00
.20
1.00
1.00
1.00
1,00
1.00
1.00
1.00
1.00
1.00
1.00
-------
C-22
in
1.00
g 0.90
c
0.80
0.70
0.60
OJ
£ 0.50
to
o 0.40 -
E o.30
o
"- 0.20 -
o.io -
120 130 140
Figure C-l Cumulative frequency distribution for 1975
mean TSP (500 and 2000 site networks)
-------
C-23
PART II: SITING FOR NATIONAL AIR QUALITY TREND STATIONS (NAQTS)
The preceeding section of the Appendix has outlined the basic criteria
for selecting geographic areas where NAQTS monitoring is to be conducted.
As explained in the main body of the report, the National
Air Quality Trend Sites (NAQTS) should be located in areas of
peak pollution concentration and in areas which combines high
population density and pollution levels. In cases where these
two situations, i.e., peak concentration and high population
density, coincide, then only one monitoring site will be necessary.
Further, it is desired that these sites not be unduly influenced
by any single point source since the primary objective of these
sites is to assess national trends.
The following material contains the procedures to be
followed in locating NAQTS within these geographical areas. (In-
sofar as possible, the SLAMS should also be located according to
these procedures. Part III of this Appendix presents additional
factors to be considered in siting SLAMS.) The discussion is
presented according to pollutant since it is desired that each
pollutant network be designed and sited independently. Only
when optimum sites for each of the pollutants have been determined,
should one consider the combination of pollutant sites at one
location. Clearly, where there are several possible locations for
a National Air Quality Trend Station (NAQTS), and one of these
locations has a NAQTS for another pollutant, then that site
should be chosen.
-------
C-24
In general, NAQTS are intended to measure air quality on
the neighborhood* scale, with the exception of CO, for which
both neighborhood and middle** scale measurements are appropriate.
Further, it is desirable that NAQTS be located in the areas where
the maximum pollutant concentration for specific time averages
are expected as shown in Table C-8.
A final consideration in selecting NAQTS is that more than
one monitor may be necessary to adequately establish peak con-
centrations. The location of peak level concentrations varies
because of the following factors: (1) source emission patterns
cause different locations of long and short term maxima;
(2) meteorological fluctuations; and (3) changes in emission
patterns caused by growth and emission control.
Procedures for Locating NAQTS
Sulfur Dioxide and TSP
There are various patterns of SOp or TSP sources
which may exist in a given area: single point sources, clusters
of point sources, area sources, a mix of area sources and a
point source, or a mix of area sources and a cluster of point
*NEIGHBORHOOD - Represents conditions throughout some reasonable
homogeneous urban sub-region with dimensions around l-2km. Homo-
geneity refers to concentration but may apply to land use as well.
**MIDDLE - Similar to neighborhood but represents conditions
in the range of hundreds of meters. In the case of CO, the area
may be more irregularly shaped because the homogenity follows
patterns of freeway corridors or streets.
-------
C-25
sources. When siting NAQTS (or SLAMS, if appropriate) each of
these source configurations should be evaluated separately. For
example, for area sources only, the maximum 24-hour and annual
averages are likely to be in the same general area, and thus
only one monitoring site would be necessary for determining
peak concentrations.
To determine which areas are subject to highest SOp and TSP
concentrations, it is desirable to first obtain emission, meteoro-
logical and population density information. Other factors such
as height of release of major pollutant contributors and topo-
graphical information on the study area should also be collected.
Dispersion modelling is extremely useful for predicting
areas of maximum 24-hour and annual pollutant averages. The
degree of sophistication required in the model depends on the
complexity of sources, meteorology and topography. If modelling
or special monitoring studies are not possible for determining
areas of peak concentration, then technical judgements based
on maps of emission densities, wind roses, topography and past
air quality data must be made.
Once model outputs and population density maps have been
assembled, candidate areas for the two types of NAQTS can be
readily identified.
Carbon Monoxide
The motor vehicle is the predominant source of CO
emissions. Thus, peak concentrations will occur among or near
clusters of motor vehicle source activity. In order to adequately
reflect the concentrations of CO in an urban area, two types of
-------
C-26
NAQTS are necessary; a maximum or peak concentration site and a
neighborhood site.
The peak concentration site is usually found near heavily
travelled downtown streets, but could be found along major arterials,
either near intersections or at low elevations which are influenced
by downslope drainage patterns under low inversion conditions. The
peak concentration site should be selected so that is it representa-
tive of several similar source configurations in the urban area,
where general population has access. Further, it is not necessarily
in the area of absolute maximum concentration. It is recognized,
however, that this site does not represent the wide-scale urban
problem. Thus, a second type of site, the neighborhood site, is neces-
sary to provide data representative of the high concentration levels
which exist over larger geographical areas.
The neighborhood site should be located in areas with a stable,
high population density, projected continuity of neighborhood character,
and high traffic density. The site should be located where no major
zoning changes, new highways, or new shopping centers are being con-
sidered. The site should be where a significant CO pollution problem
exists, but not be under the influence of any one source. Rather, it
should be representative of the overall effect of the sources in the
urban area.
Nitrogen Dioxide
Nitrogen Oxides (f^ + NO) are emitted almost entirely from
fuel combustion sources. A limited number of industrial processes
emit NO . Only a small fraction of the total NO emission consist
X A
of NOp. Most of the N02 found in the atmosphere results from oxidation
-------
C-27
of NO to N02. When ozone is present, the conversion of NO to
N02 will proceed rapidly; therefore, areas of peak N02 concentra-
tions are expected downwind of clusters of NOW point sources or
many small area sources.
In most urban areas, proven and practicable models for predicting
N02 concentration isopleths are not available. Thus, areas of peak
concentration must be determined from past air quality or emission
density information coupled with meteorological data. Peak levels
of N02 are generally found in winter. Thus monitoring sites
should be selected downwind of maximum emission density areas
based on wintertime patterns. Also, peak N02 concentrations
would be expected in areas which combine the conditions of ex-
pected high ozone concentration with high NO emissions.
X
Two types of NAQTS sites are envisioned: one in the
area of peak concentration, and one which combines high population
density and high pollution levels.
Oxidants
Oxidants are not directly emitted into the atmosphere
but result from a complex photochemical reaction involving
organic compounds, oxides of nitrogen and sunlight. Thus,
the buildup of oxidants tends to be rather slow and to occur
over relatively large areas. Under transport wind conditions,
peak concentrations may be 15 to 30 kilometers downwind of areas
with emission densities of NO and organic compounds. The
/\
peak concentration of oxidant may occur closer or further from
the center city or areas of peak emission densities depending
on city size and wind speeds.
-------
C-28
Each urban area meeting criteria discussed in Part II
would generally require only two ozone trend monitoring stations.
One station would be representative of maximum ozone levels under
wind transport conditions. It should be located approximately
15 to 30 kilometers or further downwind of the CBD based on
predominant summer/fall daytime wind patterns. The exact location
should balance local factors affecting transport and buildup of
peak 03 levels with the need to represent population exposure.
The second station should be representative of high density popu-
lation areas on the fringes of the CBD along the predominate
summer/fall, daytime wind direction. This latter station
should sense peak 03 levels under light and variable or stagnant
wind conditions. Two NAQTS ozone stations should be sufficient
in most urban areas since spatial gradients for ozone generally
are not as sharp as for other criteria pollutants.
As in the case of the N02, models generally are not avail-
able for determining concentration patterns of oxidants. Thus, past
air quality data and wind trajectory patterns coupled with NO /organic
A
compound emission data and population density maps must be used in
determining suitable locations for NAQTS.
-------
C-29
TABLE C-8
AVERAGING TIMES OF INTEREST
FOR NAQTS
Pollutant
so2
TSP
N02
°3
CO
Averaging Time
24-hour, annual
24-hour, annual
annual
1-hour
1-hour, 8-hour
-------
C-30
PART III: ADDITIONAL CONSIDERATIONS IN SITING STATE/LOCAL AIR
MONITORING STATIONS (SLAMS)
As explained in the main body of this document, State/local
air monitoring stations (SLAMS) are to be the subject of negotia-
tions between EPA Regional Offices and the various control agencies.
In locating appropriate SLAMS sites, Part II of this Appendix should
be used wherever possible. In addition, the following should also
be considered:
1. Sulfur Dioxide - The primary use of S02 data will be
to demonstrate compliance with NAAQS and provide part of the
basis for studying secondary pollutant formation. Consideration
should be given to sites in populated areas where modeling or pre-
vious monitoring indicate potential violations of NAAQS. In
areas currently below SOp standards, but subject to fuel
switching or rapid growth, data may be necessary to evaluate
current control strategy revisions. Where SOp levels have
significant fluctuations throughout the year, consideration should
be given to monitoring SC^ only during the season when elevated
levels will occur.
2. Total Suspended Particulates - As with SO,,, first
priority should be for TSP data in populated areas to demonstrate
compliance with NAAQS. In addition to roof-top monitors, special
attention should be given to locating some TSP monitors at low
levels (3 meters) in urban centers to insure compliance with
NAAQS in the breathing zone. For areas of rapid growth or changing
-------
C-31
emission patterns, there may be a need for TSP trend data.
Also, since rural TSP levels may be significant or transport
may be a problem there may be a need for long-term background
TSP data.
It is obvious that TSP could be monitored at many
locations within an area. In order to reduce the amount of
fixed monitoring, typical sites should be selected on the basis
of the "worst" case analysis, with special purpose monitoring
used to back up these sites.
Monitoring for emergency episodes should be considered
part of the SLAMS network. Only those areas which are episode
prone (as discussed more fully in the Tape Sampler Issue Paper)
should be considered for episode monitoring. Either tape sampler
or hi-vol monitoring would be acceptable for this purpose. Gen-
erally, a major reduction in the use of tape sampler monitoring
is recommended due to the relatively few areas that are episode
prone.
3. Carbon Monoxide - CO violations occur primarily in
localized areas near major roadways and intersections with high
traffic density and poor atmospheric ventilation. As these
violations can be predicted by ambient air quality modeling,
a large fixed network of CO monitors is not required. Long-term
CO monitoring should be confined to a limited number of "peak"
and "neighborhood" sites in large metropolitan areas to measure
maximum pollution levels and determine the effectiveness of
control strategies. There is little need for background CO data.
-------
C-32
4. Ozone - Since large areas experience ozone violations,
only a few selected sites should be included in the SIP. These
sites should be located both to measure peak levels downwind of
the central city of large metropolitan areas, with emphasis on
areas of high population density, and to measure transport of
ozone into these metropolitan areas. The NAQTS sites will
generally suffice for development of long-term ozone data needs
in areas where they are located.
A detailed number of urban ozone sites will be necessary
to measure population exposure or trends and to provide a data
base for new source review. Where ozone levels have significant
fluctuations throughout the year, consideration should be given
to monitoring ozone only during the seasons when elevated levels
will occur.
5. Nitrogen Dioxide - Compliance stations should be located
in major metropolitan areas with a limited number of trend stations
located in smaller metropolitan areas. The need for background
NOp sites has a low priority. Additional sites may be necessary
as a result of special studies related to the hydrocarbon N02
ratio and oxidant formation.
6. Hydrocarbons - All hydrocarbon monitoring should be
treated as special purpose monitoring until the current methodology
and instrument problems are solved.
-------
C-33
PART IV; PROBE SITING CRITERIA FOR NAQTS AND SLAMS
Once the general area for locating the station- has been
identified and a suitable monitoring site has been established
which is secure and accessible, attention must be given to
the siting of the monitoring probe.
Table C-9 presents the recommended probe siting criteria
for each of the pollutants of interest. The criteria were
selected to standardize siting practice. In addition, it was
desired to be as close as possible to the breathing zone without
obstructing pedestrian traffic or subjecting the intake of
the probe to vandalism. Further, vertical and horizontal dis-
tances above supporting structures were specified to minimize
the effects of the air stream passing near surfaces where
chemical reactions may take place and to avoid situations where
unusual micro-meteorological conditions may exist.
Distances from influencing sources were also specified
to standardize the effects these sources have on the measurement
process. This is essential if a comparable data base is to be
developed. Also distances from vegetation were specified since
they can serve as pollutant sinks.
These probe siting criteria should be viewed as goals rather
than rigid requirements which must be met in all cases. SAMWG recog-
nizes that physical constraints may make meeting these criteria
impractical. In these cases, the rationale or reasons for not
meeting the probe siting criteria should be documented.
-------
TABLE C-9. PROBE SITING CRITERIA FOR NATIONAL AIR QUALITY TREND SITES (meters)
Pollutant
Height
Above
Ground
Distance from Supporting
Structure
Vertical
Horizontal
Comments
S0
TSP
°
NO
CO
3-15
2-15
N.A.
>2
3-15
3-1
3+1/2
*20 meters from trees
*if on roof, no furnace or incin-
eration flues should be nearby
*no obstructions in directions of
frequent wind
*20 meters from trees
*if on roof, no furnace or incin-
eration flues should be nearbyb
*no obstructions in directions of
frequent wind
*20 meters from trees
*>20 meters from motor vehicle
traffic or parking lots
*20 meters from trees
*>20 meters from motor vehicle
traffic or parking lots
*at least 10 meters fromjntersections
o
i
OJ
-£>
N.A. = not applicable
3when the probe is located on a rooftop, this separation distance is in reference to
walls, parapets or penthouses located on the roof.
bd1stance is dependent on height of furnace or incinerator flue, type of waste or fuel burned and quality
of fuel (sulfur & ash content). The goal is to avoid undue influences from minor pollutant sources.
-------
APPENDIX D
DATA REPORTING AND HANDLING
I. Monitoring and Program Objectives
Twelve data uses have been identified, as shown in Table D-l.
These are the monitoring program objectives which have been dis-
cussed at length in the individual issue papers of SAMWG. These
twelve uses can be summarized in two major data use objectives:
ambient monitoring program objectives and source monitoring program
objectives. These are shown, together with the primary methods of
achieving the major objectives, in Table D-2. Specific categories
of data may be matched directly with the methods (and, therefore,
the major objectives). These categories of data--items of infor-
mation which must be collected, stored/ retrieved, analyzed, and
some cases published/distributed for further use—are shown in
Table D-3.
The contribution of data reporting and handling, following the
collection of the data and preceding analysis of the data, is a
rather minor contribution, less than three percent, to the total
cost of the comprehensive air monitoring system.
II. Ambient Criteria Pollutant Information
Ambient monitoring information includes not only the air quality
concentrations and resulting statistics, but also considers site
information, which adequately describes the site and equipment
used for sampling, quality assurance information about the collection
and analysis of the sample and surface meteorological observations.
Little air pollution meteorological data are being collected
and stored by EPA at this time; however, it is anticipated that the
-------
D-2
TABLE D-I. MONITORING PROGRAM OBJECTIVES
(Data Uses)
1. Evaluate progress and judge attainment/non-attainment of NAAQS
(incl. modeling).
2. Develop/revise/evaluate State implementation and control plans
(incl. modeling).
3. New source review, maintenance of NAAQS and prevention of significant/
non-significant deterioration (incl. modeling).
4. Develop/revise National monitoring programs, control strategies and
policies (incl. forecasting, trends and resource management).
5. Model development and research.
6. ESECA activities and EIS preparation and review (incl. modeling).
7. Support of enforcement activities (incl. source compliance, legal
actions and modeling).
8. Public information and FOI requests (incl. population exposure
and trends).
9. Establishment of NAAQS and other health research (incl. new
pollutants and population exposure).
10. Episode documentation and control activities.
11. Establishment of stationary and mobile source emission standards
(incl. control technology R&D).
12. Other special studies.
-------
D-3
TABLE D-2. METHODS OF ACHIEVING MAJOR OBJECTIVES
AMBIENT MONITORING
1. National Air Quality Trend Stations (NAQTS)
2. State/Local Air Monitoring Systems (SLAMS)
3. Special Purpose Monitoring
(Including Moveable Monitors)
4. Air Quality Modeling
SOURCE MONITORING
1. Emission Inventories
2. Stack Testing
3. In-Stack Monitoring
4. Ambient Point Source Monitoring
TABLE D-3. CATEGORIES OF DATA
AMBIENT MONITORING
1. Ambient criteria pollutant observations
Site Information
Quality Assurance Information
Surface Meteorological Observations
2. Ambient Non-criteria Pollutant Observations
Site Information
Quality Assurance Information
SOURCE MONITORING
1. Point and Area Sources of Criteria Pollutants
2. Point and Area Sources of Non-criteria Pollutants
3. Point Source Monitoring Observations (Ambient and Stack,
Criteria, and Non-criteria)
4. Enforcement/Compliance Information
-------
D-4
quantity of this information required for submittal in the future
will increase. The more comprehensive upper atmosphere meteoro-
logical data required for modeling will probably not be available
and, therefore, provision for the handling of these data will not
be considered at this time.
It has been determined that additional information about the
site of the monitoring station and the instruments and procedures
used is required beyond that currently being collected and stored.
These additional items must be identified and provision made for
their storage, retrieval and analysis. Quality assurance information
also should be made available to data users, and again the infor-
mation elements must be identified and a method for handling such
data must be developed. At this time few data are available, although
a computerized system for handling selected items does exist. This
system would need to be expanded and enhanced to accommodate the
influx of more comprehensive site and quality assurance information.
SAMWG is recommending a national network of monitoring sites
with primary purpose of reporting National Air Quality Trend Station
(NAQTS) data. These stations would meet the HQ EPA requirements
and would be fewer in number than the currently operated State/
local network of nearly 9,000 sites (see Chapter IV). There were
7749 monitors proposed under SIP's (see Table D-4). Excessive
monitoring, above the levels proposed or required for SIP's,
utilizes resources which could effectively be used for increasing
data quality rather than quantity. Table D-.4 shows that current
monitoring for TSP is 281 percent of SIP requirements. This addi-
tional workload probably is a contributing factor to the lateness
of data submittals for TSP and other pollutants, as shown in Table
-------
TABLE D-4. NUMBER OF MONITORS (Required by SJP's, Proposed In SIP's. Reporting In 4th Quarter 1975*)
TSP
Reported
State Req. Pro. IV '75
Alabaira 37 38 74
Alaska 11 28 19
Arizona 16 35 55
Arkansas 9 29 46
California 65 102 80
Colorado 27 66 73
Connecticut 19 67 64
Delaware 3 20 15
District of Columbia 4 10 0
Florida 30 30 10
Georgia 43 56 59-
Hawaii 3 12 10
Idaho 15 35 24
Illinois 56 125 155
Indiana 45 124 83
Iowa 33 44 48
Kansas 34 59 58
Kentucky 30 165 119
Louisiana 5 9 30
Maine 13 22 25
Maryland 31 74 71
Massachusetts 34 63 51
Michigan 29 127 120
Minnesota 27 68 71
Mississippi 11 29 29
Missouri 30 75 52
Montana 13 14 34
Nebraska 12 29 42
Nevada 13 34 11
New Hampshire 8 32 30
New Jersey 19 50 9
New Mexico 16 52 44
New York 72 336 9
North Carolina 54 165 132
North Dakota 6 15 28
Ohio 78 255 277
Oklahoma 24 98 1
Oregon 20 27 47
Pennsylvania 68 116 110
Puerto R1co 3 22 4
Rhode Island 7 25 17
South Carolina 40 68 72
South Dakota 6 6 14
Tennessee 39 96 101
Texas 52 221 80
Utah 11 19 23
Verirant 4 10 11
Virginia 55 108 7
Washington 31 72 60
West Virginia 24 37 42
Wisconsin 24 74 83
Wyciring 7 10 40
Guam 123
Virgin Islands 364
Saroa 1 1 0
so2
Reported
Req. Pro. IV '75
17 19 34
7 7 4
18 17 18
4 6 16
17 40 43
8 14 7
17 35 50
3 36 7
460
21 22 7
36 40 36
1 9 9
7 11 8
53 82 87
38 121 57
13 16 24
6 38 40
17 173 124
15 19 17
13 25 25
29 64 56
30 88 66
27 63 48
22 32 37
9 19 19
15 17 9
14 15 13
7 7 10
880
9 17 15
20 27 9
9 27 31
58 90 8
11 131 111
228
55 140 152
7 18 2
789
4? 59 10
4 22 3
7 25 20
20 45 56
4 4 1
18 51 54
49 232 73
11 21 16
5 9 1
23 56 0
14 25 20
12 23 28
9 39 34
3 3 7
444
4 4 0
1 1 0
Reported
Req. Pro. IV '75
0 0 16
0 2 1
11 13 11
1 1 12
30 66 74
063
10 24 41
1 24 0
340
20 20 5
15 17 32
099
0 0 1
12 27 70
13 70 54
248
0 36 39
10 163 119
000
002
14 38 56
16 j69 53
21 41 26
10 13 17
0 1 3
7 16 7
003
678
5 8 1
0 13 11
788
0 18 0
26 28 9
0 0 108
0 1 7
45 129 124
003
042
45 60 3
0 19 3
6 25 19
0 0 48
0 0 1
11 38 48
27 79 76
10 21 4
0 1 0
21 40 0
10 13 3
000
10 14 15
DOS
004
000
0«t n
o o
CO
Reported
Req. Pro. IV '75
333
1 1 3
3 4 10
000
28 57 61
365
566
1 4 0
1 5 0
000
032
020
000
10 16 3
4 7 1
0 1 2
1 5 6
0 14 7
000
0 0 1
6 20 0
6 11 8
0 10 8
4.45
000
6 13 5
0 0 1
003
220
022
8 22 0
1 3 3
13 29 0
040
000
0 24 8
040
345
11 50 10
0 1 0
042
0 0 1
000
053
1 79 1
254
0 1 0
270
796
0 1 0
0 9 1
000
000
8 8 8
Ox
Reported
Req. Pro. IV '75
443
000
334
000
32 81 83
365
5 7 1
1 4 0
1 2 0
430
1 1 0
020
000
10 12 17
473
224
3 5 5
3 12 7
5 6 3
0 0 1
6 19 0
6 12 4
0 5 0
0 5 1
232
6 13 6
002
000
2 3 1
0 1.2
7 7 0
3 3 1
19 23 0
252
000
16 24 14
440
334
11 44 10
000
0 4 1
1 1 2
000
577
19 81 10
2 5 4
0 1 0
770
575
030
4 11 4
000
000
8 8 8
Total
Pro.
64
38
72
36
346
98
139
88
27
75
117
34
46
262
329
67
143
527
34
47
215
243
246
122
52
134
29
43
55
65
114
103
506
305
18
572
124
46
329
64
83
114
10
197
692
71
22
218
126
64
147
13
6
'i
5M
AQOHS-II
Installed
State AQ
System
x j
* !
x !
x
X
X
I
X
X
X
X
X
X
K
X
X
X
X
X
X
X
X
X
X
x
X
x
x
x
x
x
X
X
X
x
X
X
X
ir
Tz~
O
I
in
*As of October 1, 1976.
-------
D-6
D-4, where, nine months after the end of the fourth quarter of 1975,
many monitoring sites were still delinquent.
It is much more effective and efficient to submit individual
observations, rather than summary statistics. For example, if 31
summary values (Table D-5) were submitted quarterly for each of 1000
sites, over 120,000 summary values would be handled annually compared
to the 227,000 observations now submitted or the 80,000 actually
required by SIP's. The number of summary items processed for con-
tinuous monitoring devices would be even more significant, con-
sidering the calculation of overlapping intervals, possibly exceed-
ing the number of observations. The quality control involved with
submittal of summary statistics would be very complex, cumbersome,
and perhaps impossible to coordinate. The submittal of summary
statistics only does not prove to be a cost or effort-saving alter-
native, especially if the unavailability of observations for veri-
fication of questionable summary values precipitates additional
personnel resource expenditures.
State/local air monitoring systems (SLAMS) will continue to
operate, collecting information primarily of use and interest to
the State and local agencies. It may be useful, on an "as needed"
basis, for EPA RO's or HQ to request a portion of these data. In
such instances either "hard copy" or machine readable form may be
requested; when machine readable data are requested, the SAROAD
format must be used. Every effort should be made to avoid develop-
ment of data handling systems, in RO's for SLAMS data, which would
be duplicative of SAROAD and result in severe drains on manpower
resources for both development and operation. Coordination of
uniform statistical computational procedures, if duplicative systems
-------
D-7
TABLE D-5. SUMMARY ITEMS
1. For all entries
1. 10th PercentHe
2. 30th PercentHe
3. 50th Percentile
4. 70th Percentile
5. 90th Percentile
6. 95th Percentile
7. 99th Percentile
8. First high value
9. First high count
10. Second high value
11. Second high count
12. Third high value
13. Third high count
14. Percent of Possible Observations
15. Arithmetic mean
16. Geometric mean
17. Arithmetic Standard Deviation
18. Geometric Standard Deviation
19. Median
20. Minimum
21. Half the minimum detectable
22. Number of Observations
23. Number of times substitute value used
24. Sum of observations
25. Sum of natural logs of observations
26. Units code
27. Flag for criteria
28. Number of primary violations
29. Number of secondary violations
30. Time of occurrence of second maximum
31. Time of occurrence of maximum
II. Also for running average intervals
32. Second maximum
33. Minimum
34. Number of observations
35. Number of primary violations
36. Number of non-overlapping primary violations
37. Number of secondary violations
38. Number of non-overlapping secondary violations
39. Units code
40. Time of occurrence of second maximum
41. Time of occurrence of maximum
42 - 54 (Repeat items 1-13)
-------
D-8
were developed, would be very difficult and computer resources would be
utilized ineffecitvely. SAROAD will continue to provide storage/retrieval
service for voluntarily submitted SLAMS data.
Monitoring which is done as a part of a short-term or special
study usually results in data which should not be used for general
purposes such as trend analysis. These data are usually so special-
ized that no other use—outside of that special purpose for which
collected—should be made without discussion with the originator
or collector of the data. Such data need not be submitted to cen-
tralized data banks, but rather remain the responsibility of the
data orignator.
III. Ambient Non-Criteria Pollutant Information
Ambient non-criteria pollutant information, observations, site
and quality assurance information, etc., are usually collected in
special projects and are used in setting ambient and emission stand-
ards or in developing national strategies or long-range criteria
studies. Currently few data are received from outside of EPA,
about 15 percent of the total data stored annually; however, State/
local agencies and other monitoring groups which collect such data
are encouraged to submit available information to EPA for access and
use by all interested parties.
The time elapsed from the end of a data collecting period until
data are available for use includes one month for sample submittal
and six months for sample analysis.
The needs of the various research and development organiza-
tions, the prime collectors and users of non-criteria ambient air
quality data, currently are being met by their own data collection/
-------
D-9
storage/retrieval/analysis systems. It is recommended that all
ambient non-criteria pollutant data be stored within EPA in a
centralized system, with a single point of dissemination and
publication in order to avoid unnecessary duplication of efforts
and enhance the ease and speed of data availability.
IV. Point and Area Criteria Pollutant Emission Information
Currently there are 175,000 points/processes in 45,000 facili-
ties (Table D-6 indicates statistics for early 1976) in the EPA
point source emissions data bank. Many of these sources are very
small and create an unnecessary overhead in maintaining the
data banks. Even though the small sources may be of significant
importance to the State/local agencies, it is not cost effective
to submit data on these sources to a centralized data bank since
EPA HQ has little need for such data. The need for emissions
related data for all very large sources and for large sources in
areas not meeting air quality standards or in areas in which the
standards are being threatened has been discussed at length pre-
viously. These data are necessary both for energy/environmental/
economic strategies analysis and for other activities utilizing
air pollutant dispersion modeling.
Data on sources should be submitted to cover an annual period,
although to reduce and/or equalize workload it would be beneficial
to submit data on a regular basis throughout the year or to forward
the information as available, rather than as a single annual sub-
mittal. Table D-^7 indicates (for TSP) that many small sources are
in the existing data files. Ideally, the minimum source size for
use by EPA in strategy analysis is 100 T/yr of any single air pollu-
tant (actual emissions).
-------
D-10
TABLE D-6. NUMBER OF PLANTS
TOTAL
NUMBER OF
STATE PLANTS*
ALABAMA
ALASKA
ARIZONA
ARKANSAS
CALIFORNIA
COLORADO
CONNECTICUT
DELAWARE
361
178
373
268
5,328
271
153
no
STATE
EIS/P&R El
INSTALLED SYSTEM
X
X
X
X
X
X
DISTRICT OF COLUMBIA 47
FLORIDA
GEORGIA
HAUAII
IDAHO
ILLINOIS
INDIANA
IOWA
KANSAS
KENTUCKY
LOUISIANA
MAINE
MARYLAND
MASSACHUSETTS
MICHIGAN
MINNESOTA
MISSISSIPPI
MISSOURI
MONTANA
NEBRASKA
NEVADA
NEW HAMPSHIRE
NEW JERSEY
NEW MEXICO
NEW YORK
NORTH CAROLINA
NORTH DAKOTA
OHIO
OKLAHOMA
OREGON
PENNSYLVANIA
PUERTO RICO
RHODE ISLAND
SOUTH CAROLINA
SOUTH DAKOTA
TENNESSEE
TEXAS
UTAH
VERMONT
VIRGINIA
WASHINGTON
WEST VIRGINIA
WISCONSIN
WYOMING
GUAM
VIRGIN ISLANDS
902
872
136
297
697
1169
655
1,682
754
416
576
213
1,100
714
635
1,546
876
109
1,382
120
277
560
317
5,513
2,055
657
1,323
227
723
1,589
247
266
456
897
743
496
84
154
663
769
199
302
78
15
17
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
40567
20
10
*In NEDS data bank, February 1976.
-------
D-ll
TABLE D-7. PROFILE OF 80,000 PARTICULATE POINT
SOURCES IN 35,000 PLANTS*
Percent of
Source Percent of the total number of total national
size point sources with particulate participate
(T/yr) . emissions emissions
Points Plants
0-100
101-500
>500
89
8
4
84
11
5
8
13
79
*Size distributions for other pollutants indicate more
larger sources than for particulate. There are an additional
8,000 plants with 52,000 points having no particulate emissions,
TABLE D-8. COMPLETENESS OF SOURCE INVENTORY DATA BASE
Data Percent of completeness*
items by source size
Identifiers 0-100 T/yr 101-500 T/yr >500 T/yr
General Information 90 90 90
Emission Related Data 95 95 97
Data for Modeling 88 90 80
Enforcement Data 70 50 50
*As of October 1976.
-------
D-12
Based upon an anticipated reduction in required reporting, the
previous discussion has indicated that information on 20,000 par-
ticulate sources in 6,000 plants will be submitted each year. The
number of other facilities emitting 100+ T/yr of the remaining
criteria pollutants (not included in the TSP estimates) are:
SOV - 4000
A
NOV - 1500
A
HC - 9000
CO - 1000
Ave. no. pts.
15,500 x 3.5 Facility = 52,500 emitting points
These, combined with the TSP sources,total 72,500 emitting points
to be included in the data file. This workload exceeds that which
might be accomplished manually, thereby necessitating an automated
system. In addition, it may be expected that efforts at increasing
the completeness of information about plants/sources would result
in an increase in automatic data processing activities.
More detailed and accurate data on area (county) sources are
required for national strategy analysis, especially in areas exceed-
ing or threatening NAAQS. Currently all area source data are
collected and compiled internally at EPA headquarters. These data
are, for the most part, apportioned from larger areas (such as States)
which have statistics available. This procedure is insufficiently
sensitive in the estimating of emissions of certain pollutants (such
as HC and CO) from some source categories (such as LDV, HDV, and
other transportation sources). Although VMT or fuel consumption
figures are sometimes available to EPA, for the most part these
data are only available from local governmental agencies. For
use in dispersion modeling—again in areas where NAAQS are exceeded
-------
D-13
or threatened—it is very important that data available locally
be submitted for the estimation of area source emissions.
At this time emissions calculating capabilities are limited
primarily to total HC, whereas a more significant and more usable
statistic would be emissions of the organic classes of compounds.
Actions should be taken both in emission factors and data handling
to provide for the calculation of these emissions.
More detailed data about large sources are required for in-depth
modeling studies. These sources dominate the dispersion model
results; therefore, the parameters most frequently used in the
modeling calculations must be available and resources should be
assured to maintain annual currency and freedom from errors which
would render the modeling results incorrect. Table D-8 indicates
the percent completeness for point source data, with about 10
percent of the important items of data missing. For 22,500 point
sources approximately 500,000 items of necessary data are currently
unavailable.
There is some question as to the need for all of the data now
required for each point source in the file. A study group, formed
from data users, should ascertain exactly which items of informa-
tion are absolutely required, and the data system modified accord-
ingly.
V. Point and Area Non-Criteria Pollutant Emissions Information
The collection of point and area non-criteria pollutant source
information is primarily a special studies activity, and as far as
EPA usage is concerned, this activity seems to be oriented towards
the setting of both NAAQS and emissions standards.
-------
D-14
These data are now collected internally and the needs of the
various HQ organizations, the prime collectors and users of non-
criteria source inventory data, currently are being met by their
own data collection/storage/retrieval analysis systems. State/
local agencies and EPA do collect such information, on as as-needed
basis, and may be contacted infrequently by potential data users.
When such data are available, it is suggested that submittal to
EPA HQ would result in greater useability and availability when
incorporated into the existing system.
VI. Point Source Monitoring Observations (Criteria and Non-Criteria
Pollutants)
Both in-stack and ambient monitoring are associated with point
source monitoring. Both of these activities are usually associated
with special studies or enforcement actions. The in-stack data
results do not provide information for development of emission
factors since the many other variables required for the development
of emission factors (throughput amount and composition, theoretical
and actual operating rates, control device operating parameters,
etc.) are not known. The ambient monitoring is usually at fence
line or anticipated plume touch down or other areas of high concen-
tration and, therefore, does not represent general population
exposure locations. Neither of these data results are suitable
for generalized data usage. Although probably meeting the special-
ized needs very well, they should not be stored in centralized EPA
data banks, but rather be held by or storage arrangements made for
by the data originator.
-------
D-15
Source test/emissions monitoring data collected by EPA which
are sufficient for development of emission factors should be sub-
mitted within EPA in accordance with EPA Orders. State/local
agencies willing to share such information should contact EPA, and
arrangements will be made to collect the data.
VII. Enforcement/Compliance Information
Currently, although there is a capability for storage/retrieval
of compliance information in the existing air data systems, such
data are usually stored in the Compliance Data System (CDS) which
is a management information tracking system operated by DSSE, OEGC.
This situation seems to adequately meet the requirements of RO's.
However, a major problem exists for some blocks of data in that the
source ID's for the air data systems and CDS are not compatible.
It is, therefore, impossible in many cases to put the engineering/
emissions data together with the compliance information.
This problem must be rectified to increase the useability and
usefulness of both systems. Some efforts are currently underway
to correct the ID mismatch, but some RO's have not yet begun to
make the changes required such that any source in both CDS and
NEDS must have the NEDSXREF number (ID) coded into the appropriate
CDS format. There is no intention of having all sources common to
both data banks, however. Those which appear in both banks should
be cross-referenced and kept up to date. This will require RO
coordination and resolution of discrepancies when/if State/local
agencies or RO's change ID numbers.
-------
D-16
VIII. Categories of Data Users
Seven categories of data users have been identified, as shown
in Table D-9. Each of these user groups have somewhat different
use requirements. In order to ascertain the specifications for the
required data handling systems, it is necessary to ascertain the
requirements of each of the user groups. In many instances the
requirements may be conflicting, in which case resolution will be
necessary, usually selecting the more stringent specifications.
The number of requests processed by RO's directly is not known
at this time. However, in the future, anticipating additional com-
puter capability, only the most complex or highest printout regional
office requests will need to be processed outside of RO's, except
for national or inter-regional requests which will still require
centralized processing. Most of the requests shown in Table D-9
require multiple runs, sometimes as many as 25 to satisfy a single
request.
IX. General Data Reporting and Handling System Design Specifications
In considering the system design specifications, it must be
understood that only the major system requirements can be con-
sidered—exceptions must be handled outside the system. There is
no possibility of providing an all-encompassing system meeting the
requirements of all potential users without incurring costs several
orders of magnitude over those resources which may be assumed to be
available.
Furthermore, this is an attempt to develop a generalized set
of specifications for data reporting and handling—details on
design and implementation will be developed by the organization(s)
assigned the responsibility for an action plan.
-------
D-17
TABLE D-9. CATEGORIES OF DATA USERS
1. EPA RO's (Including S&A, A&HM, Enforcement, etc.)
2. EPA HQ (Program offices only)
3. EPA R&D (Including all ERC's and ORD HQ)
4. State Agencies
5. Local Agencies
6. Other Federal Agencies
7. Private Sector
PERCENT OF TOTAL NATIONAL AIR BANK
INFORMATION REQUESTS
PROCESSED BY NADB, FY 76*
Requestor NEDS SAROAD
Regional Offices 28% 32%
OAQPS, Other EPA, Other Federal Agencies 52% 50%
Private Sector 20% 18%
Total Number of Requests Received: 549 749
*Numbers of requests processed by RO's or handled by direct
access of data files are unknown due to current computer accounting
procedures.
-------
D-18
Table D-D provides the general system specifications which must
be determined for each user, each data category. These items have
been reduced to the form in Table D-ll, which can be completed for
each data user; the results can then be used to design the specific
data handling system to meet the most stringent requirements. Table
D-U now shows, for all user categories, the most stringent system
specifications required, as determined in SAMWG deliberations.
These specifications will determine the required development or
modification of edit updating, maintenance, and retrieval com-
ponents of the effected systems.
The design specifications have been listed in order that
systems can be modified or developed to meet the majority of the
requirements of most of the users. The design specifications are
self-explanatory and provide the basic information for designing
new or modified data systems. A flow chart showing the relationship
and responsibilities for data handling is given in Figure D-l.
X. Other Operations
A. State Systems
1. Automatic
States which handle large amounts of data require auto-
matic handling systems. Table D-4 indicates that 25 States have the
EPA-developed air quality data handling system and 12 have their
own systems. Table D-6 shows that 20 States have the EPA-developed
emissions inventory data handling system and 10 have their own
systems. A survey in 1975 of the potential for installation of
additional data handling systems in State offices provided the infor-
mation in Table D-12. There is little possibility of additional
-------
D-I9
TABLE D-10. GENERAL SYSTEM DESIGN SPECIFICATIONS
1. Preferred Originator of Data (from Categories of Data Users)
2. User of Data (from Categories of Data Users)
3. Preferred Data (select one)
a. Summary Statistics (detailed summary procedures to be
specified later)
b. Comprehensive/Detailed/Raw Observations* also results in
summarized data
4. Preferred Data Form
a. Hard Copy
b. Machine Readable (must be fixed format), also results in
hard copy
5. Preferred Data Use Format
a. Fixed Format
b. Optional/Flexible/Non-Specified Format
6. Preferred Storage Responsibility
a. Local (multiple locations)
b. State (54 locations)
c. RO's (10 locations)
d. HQ
e. R&D
7. Frequency of Reporting - from Preferred Originator of Data to
Preferred Storage Responsibility (number of times per year)
8. Time Elapsed - from end of reporting period until user can
access data in preferred form/format from preferred storage
responsibility (days)
-------
D-20
TABLE D-ll. USER REQUIREMENTS
Data User: EPA RO's (Including S&A, A&HM, Enforcement)
EPA HQ (Excluding Enforcement and R&D)
EPA R&D
State Agencies
Local Agencies
Other Federal Agencies
Private Sector
System Design
Specifications
Data Originator
Data User
Data: Summary
Comprehensive
Form: Hard Copy
Machine
Format: Fixed
Non-specified
Storage
Reporting
Frequency
Time Elapsed
DATA
Ambient Criteria
Information
NAQTS SLAMS
S&L
HQ
C
M
F
HQ
Q
90
days
S&L
S&L
S
H
F
S&L
As
Needed
Ambient Non-
Criteria
Information
R&D
R&D
C
M
F
R&D
Q
210 days
Point & Area
Criteria
Information
S&L
HQ
C
M
F
HQ
A
90 days
CATEGORIES .
Point & Area Non-
Criteria
Information
HQ
HQ
C
M
F
HQ
As Needed
-
Point Source
Monitoring
Information
S&L
RO
C
H
NS
S&L
As Needed
-
Enforcement and
Compliance
Information
RO
RO
C
H
F
RO
Q
30 days
f Quarterly
A Annually
-------
NAQTS
data
State Sys-
tem or
AQDHS II
User
SLAMS
P
data
__ fl<; NEEDED ^
AS NEEDED
RO
I
User
Non-Criteria
Ambient
Monitoring
r , AS "VATI AW F ^
Samples
State
System
ORD
AS NEEDED f^
User
I
ro
data
State Sys-
tem or EIS/
Annually .
User
Other Point
Source Moni-
toring
data
AS NFFDED ..
RO
AS" NEEDED
FIGURE D-l. Flow Chart for Data Handling Responsibilities
-------
II
III
IV
VII
VIII
IX
TABLE D-12. COMPUTATIONAL FACILITIES AVAILABLE TO
NO. OF
STATE MAKE MODEL CORE
Connecticut IBM 370/165 3M
Rhode Island IBM 370/158(4) NR
Maine Honeywell 6000 256K
Massachusetts CDC CYBER 72 93K words
New Hampshire Honeywell 6066 256K words
Vermont Not reported
Puerto Rico IBM 370/155 700K
New York IBM 370/155 500K
Burroughs 3500 150K
New Jersey IBM 370/145 750K
Virgin Islands No computer available
Delaware IBM 360/50 51 2K
Maryland Not reported
Pennsylvania Not reported
Virginia IBM 370/158 2M
W. Virginia Not reported
Alabama UNIVAC 1110 NR
Florida UNIVAC 70 196K
Georgia UNIVAC 1110 262K
Kentucky IBM 370 NR
Mississippi IBM 370/155 2M
North Carolina IBM NR NR
South Carolina IBM 370/158(4) 2M
Tennessee IBM NR NR
Illinois IBM 370/165 NR
Michigan IBM 370/155 75K
CDC 6500 96K
Wisconsin UNIVAC 9400 64K
Minnesota CDC 3300 230K
Ohio IBM 370/158 2M
Indiana IBM 370/165 5M
Arkansas Not reported
Texas UNIVAC 1106 262K
.Oklahoma IBM 370/145 NR
Louisiana No computer available
New Mexico IBM 370/158 NR
Missouri IBM 370/155 NR
Nebraska Not reported
Iowa IBM 370 86K
Kansas Not reported
Colorado IBM 370/145 1M
Montana IBM 370/145 NR
North Dakota IBM 370/145 1M
South Dakota Not reported
Utah Not reported
Wyoming IBM 370/155 NR
Arizona Honeywell 6000 NR
California CDC 3300 96K
Nevada UNI VAC i!08(4) 256KM
Hawaii No computer available
Guam No computer available
Alaska IBM 370 NR
Idaho Not reported
Oregon Not reported
Washington Not reported
(1) C indicates ANSI COBOL compiler available
F indicates ANSI FORTRAN compiler available
STATE 1
(D
TAPES COMPILER
NR
4
12
4
11
6
NR
4
NR
NR
NR
NR
6
8
NR
NR
NR
12
NR
20
12
4
2
4
20
NR
6
NR
3
NR
4
NR
NR
•NR
NR
NR
6
NR
NR
C, F
C, F
C, F
C, F
C, F
C, F
C, F
(3)
C, F
C,
C, F
C, F
C, F
C, F
C, F
C, f
C, F
C, F
C, F
C, F
C, F
C, F
F
C, F
C, F
C, F
C, F
C, F
C, F
C, F
C, F
C, F
C,
C, F
C, F
C, F
C, F
C, f
C, F
AGENCIES
(2)
USAGE
El AQ
AQ
AQ
El AQ
AQ
El, AQ
El
AQ
AQ
El
El, AQ
AQ
AQ
, AQ
El, AQ
El
El
El, AQ
El, AQ
El, AQ
El
, AQ
El, AQ
El, AQ
, AQ
El, AQ
El, AQ
AQ
El, AQ
El, AQ
El
El
-EI^AQ.
El
El, AQ
, AQ
El, AQ
AQ
AQ
El, AQ
ADEQUATE
TIME
E_
Y
Y
Y
Y
NR
NR
Y
Y
NR
Y
Y
NR
NR
Y
NR
NR
Y
NR
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
NR
Y
Y
N
Y
Y
Y
Y
NR
Y.
Y
Y
NR
Y
Y
Y
N
N
Y
ft
Y
Y
Y
Y
Y
NR
Y
NR
Y
Y
N
NR
NR
Y
NR
Y
Y
Y
Y
Y
NR
Y
Y
Y
Y
Y
Y
Y
V
Y
NR
Y
Y
N
Y
Y
NR
Y
NR
Y._
NR
Y
Y
Y
Y
Y
N
N
Y
(2) El indicates computer may be used to support the emission inventory
AQ indicates computer may be used to support the air quality system
(3) Does not have ANSI compilers
(4) Computer time is rented commercially
D-22
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D-23
installations, since few States with large numbers of sources/
monitors do not already have automatic data handling capabilities;
many States are also short of computer capabilities as shown in
Table D-12.
Currently the EPA-developed Comprehensive Data Hand-
ling System does not have sophisticated editing or retrieval/analysis
capabilities! and considerable improvement is required in these
two areas. In addition, EPA should continue to support a high
level of assistance to State systems users due to their turnover
in personnel, technical problems with their equipment facilities,
scarcity of resources, and usual system updates, and to assure and
maintain compatibility and uniformity in order that the data will
be usable and useful.
2. Manual
Some State agencies, due to financial, computer, or
manpower shortages, or because of a few monitors and/or sources, must
handle data manually. There is a possibility for some activity in
this area of providing more efficient manual systems recommendations
or time-saving techniques. However, this may not be a cost-effective
effort for EPA, since most of the States operating on a manual
basis do submit data in a timely fashion.
B. Clearinghouse Operations
There has been some discussion that a single organization
be given the responsibility for collecting and providing information
concerning the existence and availability of air pollution associated
data. Such a service would provide requestors with information on
the originator, location, and perhaps form/format of data. These
statistics would include information on special projects, State/local
monitoring, source testing and monitoring, and other information not
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D-24
routinely submitted for EPA storage. There is no intention of
storing data in the clearinghouse, merely storing information about
the data.
At the air monitoring workshops held in January 1977, a
general consensus emerged on the potential usefulness of such a
clearinghouse and that such an activity would best be operated
centrally. EPA's Office of Air Quality Planning and Standards
will initiate a study to determine the best and most economical
means for establishment and operation of the clearinghouse. Sub-
sequent to this study, operating procedures will be prepared and
the initial information base will be collected. The procedures
for reporting, collection, storage and dissemination of such infor-
mation will be provided to all data originators and to all prospective
users.
Milestones and an estimated schedule for implementation
of the clearinghouse are presented in Table IX-1. The information
to be handled by the clearinghouse will include:
1. a listing of SLAMS, updated annually;
2. annual listing of significant special purpose
monitoring projects for both criteria and non-criteria pollutants;
3. a listing, provided by industries, of point source
monitoring performed (updated annually);
4. information on monitoring methods for the non-criteria
pollutants.
The information indicated above should be printed and
disseminated on a routine bases to all interested users.
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-450/2-77-010
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
Air Monitoring Strategy For State Implementation Plans
5. REPORT DATE
June. 1977
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Standing Air Monitoring Work Group
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Monitoring and Data Analysis Division
Office of Air Quality Planning and Standards
U.S. Environmental Protection Agency
Research Triangle Park, N. C. 27711
10. PROGRAM ELEMENT NO.
2AF643
11. CONTRACT/GRANT NO.
N/A
12. SPONSORING AGENCY NAME AND ADDRESS
Same as 9
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES . . , -. . . , , . , , j. ^ , • j
Prepared in cooperation with State and local air pollution control agencies, and
EPA Headquarters and Regional offices.
i6. ABSTRACT Tnjs document describes the air monitoring strategy for State implementation
plans developed by the Standing Air Monitoring Work Group (SAMWG). It presents a
summary of their review and evaluation of current air monitoring activities. A
discussion of SAMWG1s findings and their resulting air monitoring strategy for State
implementation plan monitoring is described.
The major topics discussed in the strategy are: (1) Ambient monitoring, (2)
Source monitoring, (3) Future monitoring for non-criteria pollutants, (4) Quality
assurance activities for ambient and source monitoring, (5) Analysis and interpretatio
of air quality information, (6) Anticipated impact of the strategy and (7) Imple-
mentation of the strategy.
It was anticipated that the resources associated with air monitoring activites
would not change substantially in the near future. Thus the strategy recommends a
reallocation of the local monitoring resources so that the overall result will be a
more cost-effective monitoring program. A phased implementation approach is also
suggested in order to minimize the resource impact of the recommendations in any one
year. However, the strategy emphasizes that even with a phased approach, implementatio
of the recommendations will require more resources, especially for expanded quality
assurance programs and the purchase of new instruments to replace obsolete or
unacceptable analyzers.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
Ambient monitoring
Source monitoring
Non-criteria pollutant
monitoring
Quality assurance
Data analysis
Air monitoring strategy
c. COSATI Field/Group
Air Quality Measurements
General and Miscellaneous
Review (General)
Administrative
Compilation
8. DISTRIBUTION STATEMENT
Release Unlimited
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
241
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
*U.S. GOVERNMENT PRINTING OFFICE: 1977-740-1K* 325 REGION NO. 4
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