United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park, NC 27711
EPA-450/2-90-012
July 1990
AIR
EPA
Designing and Implementing
an Air Toxics Control Program:
A Program Development Manual
for State and Local Agencies
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DESIGNING AND IMPLEMENTING
AN AIR TOXICS CONTROL PROGRAM:
A PROGRAM DEVELOPMENT MANUAL
FOR STATE AND LOCAL AGENCIES
Prepared by:
Noncriteria Pollutant Programs Branch
Office of Air Quality Planning and Standards
U. S. Environmental Protection Agency
Research Triangle Park, NC 27711
Juiy 199C
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FOREWORD
This program development manual was prepared by the U. S. Environmental
Protection Agency (EPA) at the request of the State and Territorial Air Pollution
Program Administrators and the Association of Local Air Pollution Control Officials
(STAPPA/ALAPCO). The manual is intended to assist State and local (S/L) air
pollution control agencies in making informed decisions about the development of air
toxics control programs and to enhance consistency among S/L program approaches.
In particular, insight is provided into how to make critical decisions regarding program
scope and stringency, evaluation of program impacts, and achievement of overall
program effectiveness. While the information contained in this manual does not
represent EPA policy, it should prove useful to many S/L agencies now actively
engaged in air toxics program development.
In order to develop the manual, the advice and experience of S/L agencies at
various stages in their own program development were sought and incorporated into
this manual. The State of Maryland, currently in the implementation phase of their
air toxics program, provided advice and information based on the State's own
experience with program design. The States of Colorado and Illinois, currently taking
on the challenges of planning air toxics programs, helped identify issues and decision
points faced by States in the early stages of program development. The information
in the manual attempts to address these issues by illustrating the experiences of S/L
agencies and EPA. in making air toxics program decisions.
The control of toxic air pollutants is a high priority for both S/L and EPA.
Studies have revealed numerous sources of air toxics nationwide, including both point
sources (e.g., smokestacks and process vents) and area sources (e.g., vehicles and
other highly dispersed emission points). Data compiled under Section 313 of the
Superfund Amendments Reauthorization Act show that 2.7 billion pounds of toxic
chemicals are released to the air annually from industrial sources alone; many of the
chemicals released are known or suspected cancer-causing agents.
In response to the air toxics problem, EPA developed and implemented the
National Air Toxics Strategy in 1985. This policy calls for action on high risk point
111
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sources, the complex mixture of pollutants in urban areas, and mobile sources. The
strategy also strongly supports the development of S/L air toxic control programs as
an important part of an overall national effort to reduce toxic air emissions. In
particular, the strategy has a goal that each S/L agency develop a program capable of
addressing high risk point sources and carry out any federally adopted rules. Support
by EPA for achieving this goal includes development grants, technical assistance,
operation of technical assistance centers, air quality monitoring programs, and
guidance documents.
Since 1985, a majority of S/L air pollution control agencies have established
programs to address their air toxics problems. A significant trend is a growing
similarity in S/L air toxic programs. While some programs give somewhat greater
emphasis to one control approach over another, virtually all programs today include a
combination of at least two basic program elements: use of control technology and
ambient impacts requirements. In fact, use of these mutually reinforcing control
program elements has emerged as the predominant feature of S/L programs. For this
reason, the manual uses this multi-element approach as the baseline for discussing
approaches to control of toxic air emissions.
To date, most S/Ls have focused their regulatory efforts primarily on individual
high risk point sources; thus, high risk point source control is the focus of the manual.
However, both S/Ls and EPA recognize the importance of addressing the problems of
area sources, motor vehicles, and other clusters of sources. Research and regulatory
activities are ongoing in these areas. The emphasis of this manual on high risk pomr
source control is not intended to minimize the importance of these other problem
areas. .
At the tune this manual was developed, efforts were underway to amend the
Clean Air Act. While the nature of these amendments will become increasingly clear,
it is already clear that a substantial increase in the number of sources regulated under
federal rule is expected. S/L agencies currently engaged hi rule development should
consider designing their programs to complement the anticipated control approach,
source/pollutant applicability, and implementation framework set forth by the current
legislative proposals. Accordingly, S/L agencies with developing programs are further
iv
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advised to consult with applicable EPA officials to incorporate the current best
understanding of the future federal program.
The sections that follow include: Section 1.0, Designing the Basic Program
Approach; Section 2.0, Making Critical Design Choices: Scoping the Program; Section
3.0, Evaluating Program Impacts; and Section 4.0, Avoiding Pitfalls.
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TABLE OF CONTENTS PAGE
FOREWARD iii
LIST OF TABLES ix
LIST OF FIGURES ri
ACKNOWLEDGEMENTS xiii
1.0 DESIGNING THE BASIC PROGRAM APPROACH 1
1.1 DEVELOPING AN AIR TOXICS CONTROL PROGRAM 1
1.1.1 Why Have an Air Toxics Program? 2
1.1.2 Defining the Problem and Designing the Program 2
1.13 Implementing, Enforcing and Evaluating the Program 7
1.2 .APPROACHING .AIR TOXICS CONTROL
COMPREHENSIVELY 8
1.2.1 Converging Program Approaches 8
1.2.2 Putting the Elements into a Comprehensive Framework .... 10
2.0 MAKING CRITICAL DESIGN CHOICES 1
2.1 SELECTING POLLUTANTS OF CONCERN 2
2.1.1 General Approaches 2
2.1.2 Steps for Selecting Pollutants 4
2.2 SELECTING SOURCE CATEGORIES OF CONCERN 13
2.3 REGULATING EXISTING SOURCES 16
2.4 SELECTING SIZE AND EMISSION CUTOFFS/EXEMPTIONS . . 20
2.5 TIMING/PHASING OF PROGRAM COVERAGE 20
2.6 AGENCY RESOURCE REQUIREMENTS 21
3.0 EVALUATING PROGRAM IMPACTS 1
3.1 WHAT ARE THE COSTS? 1
Vll
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3.2 SELECTING A METHODOLOGY: MARYLAND'S APPROACH . 2
32.1 Compliance Costs 3
3.2.2 Administrative Costs 7
3.3 SELECTING A METHODOLOGY: NORTH CAROLINA'S
APPROACH 7
3.4 PLANNING A COST OR ECONOMIC IMPACT EVALUATION . 11
4.0 AVOIDING PITFALLS 1
4.1 DEFENDING THE PROGRAM ALONG THE WAY 1
4.2 ENSURING EFFECTIVE COMMUNICATION , . 2
4.2.1 Communicating Early and Often .................... 2
4.2.2 Understanding the Nature of
Environmental Communication ....... . ............ 2
4.2.3 Communicating Program Objectives .................. 6
4.2.4 Meeting Your Communication Objectives .............. 8
4.2.5 Communicating About Risks ...... . ............... 12
4.2.6 Working With the Press ......................... 14
4.3 COORDINATING WITH OTHER REGULATORY
PROGRAMS .................................... 15
43.1 Recognizing the Commonality of Different Regulatory
Programs .................................. 16
4.3.2 Coordinating with State Implementation Plans fSIPV. ...... 17
4.3.3 Coordinating with Other Toxics-Related Programs ........ 27
4.4 MEASURING PROGRAM EFFECTIVENESS
4.4.1 Need for an Air Toxics Program Performance Measurement
System .................................... 34
4.4.2 Performance Criteria ........................... 36
4.43 Example Measurement Techniques ................. . 38
VIII
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LIST OF TABLES PAGE
1-1 SUMMARY OF TECHNOLOGY ELEMENT 14/15
1-2 CITATIONS TO CONTROL TECHNOLOGY
REQUIREMENTS 19
1-3 SUMMARY OF AMBIENT IMPACT ELEMENT 22/23
1-4 EQUIVALENT UNCERTAINTY FACTOR FOR 24-HOUR
AVERAGING TIME 27
1-5 LIST OF POLLUTANTS FOR WHICH INHALATION
REFERENCE CONCENTRATIONS (RfCs) HAVE BEEN
DEVELOPED 29
1-6 EXAMPLE CALCULATION OF AAL FROM UNIT RISK
FACTOR 30
1-7 POLLUTANTS WITH EPA INHALATION UNIT RISK
FACTORS 31
1-8 CITATIONS TO AMBIENT IMPACT REQUIREMENTS 34
1-9 PRIMARY EPA SOURCES OF RISK ASSESSMENT
INFORMATION 39
2-1 CASE EXAMPLES: BASIS FOR POLLUTANT
SELECTION 6/7
2-2 LISTS OF CARCINOGENIC COMPOUNDS 8
2-3 SOURCE CATEGORIES S/L's REPORT EXEMPTED 17/18
2-4 DE MINIMIS LEVELS REPORTED BY S/L AGENCIES . . 22/23
3-1 CONSIDERATIONS IN THE PLANNING OF
REGULATORY IMPACT EVALUATIONS 12
4-1 LIKELY ADVERSE COMMENTS AND SUGGESTED
RESPONSES 3/4/5
4-2 TOXICS - RELATED PROGRAMS INFORMATION 28
4-3 EXAMPLE PROGRESS MEASUREMENT TECHNIQUES .... 39
IX
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LIST OF FIGURES PAGE
1-1 STEPS IN PROBLEM DEFINITION 4
1-2 DESIGNING AN AIR TOXICS PROGRAM 6
1-3 COMPREHENSIVE APPROACH TO CONTROLLING
AIR TOXICS EMISSIONS 9
1-4 FACTORS TO CONSIDER IN DESIGNING A
COMPREHENSIVE AIR TOXICS CONTROL PROGRAM .... 12
1-5 KEY DECISION POINTS FOR CONTROL TECHNOLOGY
ELEMENT 17
1-6 KEY DECIsioN POINTS FOR AMBIENT IMPACT
ELEMENT 24
XI
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ACKNOWLEDGEMENTS
This manual represents a collaborative effort between the U. S. Environmental
Protection Agency (EPA) and State and local (S/L) air pollution control agencies.
Information and case examples presented in this manual were gathered from a variety
of sources, including numerous contracts with S/L agencies over a long period of
time. The EPA would like to specifically acknowledge the contributions of the State
of Maryland whose personnel provided extensive input and assistance to EPA during
the preparation of the manual. The EPA is also grateful to personnel from the
States of Colorado and Illinois for reviewing and commenting on the manual several
times prior to its publication.
The EPA's effort to provide ihis document was also ably supported by Frank
Sheffield of Radian Corporation, Alice Pelland, of ABB Environmental Services, Inc.
and Jim Rickun of RMT, Inc. The EPA authors were Martha H. Keating and
Michael A. Truma, both of the Office of Air Quality Planning and Standards.
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SECTION 1.0
DESIGNING THE BASIC
PROGRAM APPROACH
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1.0 DESIGNING THE BASIC PROGRAM APPROACH
Highlights of This Section
Reasons for developing an air toxics program include prevention
of future health problems, the need for a system to handle high
risk sources, and a national policy supporting 3/L program
development.
Air toxics program development begins with assessing the problem
and designing the program; extensive data collection is not
necessary to get started.
Implementation, enforcement and evaluation follow.
A comprehensive approach, combining control technology and
ambient impacts requirements, is a good starting point for
development of a long-term program.
A comprehensive approach capitalizes on the best features of
individual elements and provides flexibility for future changes.
1.1 DEVELOPING AN AIR TOXICS CONTROL PROGRAM
This subsection describes how State and local (S/L) agencies proceed from
recognizing the need for additional air toxics control to designing and implementing a
regulatory program. This subsection will be most useful to agencies jusi beginning a
program.
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1.1.1 Why Have an Air Toxics Program?
Understanding the need for an air toxics program is an important issue that
should be addressed early. Some of the main reasons for developing a program
include:
o Protection of Public Health - The primary goal of S/L pollution control
agencies, and the basic argument in favor of an air toxics program, is
the protection of public health. Studies associating air toxics with
elevated cancer levels and other adverse health effects, as well as
monitoring data and data from Title HI of the Superfund Amendments
Reauthorization Act (SARA Title HI) showing large quantities of toxics
being emitted, support the conclusion that there is an air toxics problem
that needs 10 be addressed. The public"'? demand for clean air and
protection from exposure to air toxics is also a basis for developing an
air toxics program. Some S/L agencies have developed programs as a
reactive or curative measure to address problems that already exist.
Many S/L agencies now developing programs reason that the need to
prevent future air toxics problems (and subsequent health risks) is a
legitimate basis for justifying a program. This "preventative approach" to
air toxics control allows agencies to act rather than react.
o National policy supporting S/L air toxics control programs - As
mentioned in the Foreword, the National Air Toxics Strategy strongly
supports S/L program development. This strategy was prompted by
EPA studies suggesting potentially significant health risks from exposure
to air toxics. The current Federal program will be strengthened with
adoption of Clean Air Act amendments.
1.1.2 Defining the Problem and Designing the Program
In the early stages of program development, a S/L agency collects and
evaluates information to define the specific tasks that must be completed to develop a
program. At this point, the agency's list of action items might include:
o Defining the basic steps - The S/L agency should define the steps
required to define the air toxics problem and design the air toxics
program. The steps might include completing a review of legal
authority, preparing of draft regulations or guidelines, and developing
1-2
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a communication strategy to facilitate program approval and
implementation.
o Problem definition. A large data collection effort is not a prerequisite
for defining the problem and, in fact, can deplete agency resources
without achieving progress toward program approval. SARA Title HI
data and a point source screening survey may be enough to launch a
program. If a preventative approach is adopted, little effort needs to be
expended on documenting existing toxics-related health problems.
o Identification of air toxics of concern - Some S/L agencies use an open-
ended approach, regulating any noncriteria pollutants: others use a
specific list. Identifying pollutants of concern can start with a review of
various State and national lists (e.g., EPA's lists associated with proposed
Clean Air Act amendments), or lists from the National Institute of
Occupational Safety and Health (NTOSH), or the American Conference
of Governmental Industrial Hygienists (ACGIH). These lists can be
reviewed in conjunction with emission inventory or SARA Title ffl data.
Some S/L agencies have undertaken chemical-specific health effects
reviews, and selected chemicals based on these reviews.
o Identification of air toxics sources - To define what sources will be
included in the program, sources of air toxics emissions could be
identified using source surveys, reviewing emission inventory or SARA
Title HI data, or reviewing various national databases that can help
identify source categories of concern (see Section 2.2).
o Review of agency legal authority - Where any questions exist as to
whether or not the agency has the authority to regulate air toxics,
confirmation of legal authority to regulate air toxics is recommended.
Most S/L agencies have not needed additional legislative authority, and
have undertaken policy or guidelines development or ruiemaking via
tneir general air pollution control authority.
o Consideration of interim measures - Because program development
requires a significant period of time, several S/L agencies implemented
interim control strategies such as informally reviewing new and existing
sources for toxics as they apply for construction and/or operating
permits. Others have screened existing sources to help define the
problem and encourage voluntary actions by problem sources. These
interim measures can mitigate air toxics problems until a full program is
in place, and can also build a valuable base of knowledge and operating
experience.
Figure 1-1 summarizes key issues in the problem definition step.
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What are the objectives
for program development?
What are the air toxics
of concern?
Defining the air toxics problem
Review of legal authority
Preparation of draft policy
or regulations
Development of communication
strategy
Other States lists
National lists
Emission inventory data
Health effects reviews
of individual pollutants
What are the sources
of air toxics?
Is there adequate legal
authority for regulating
air toxics?
What interim measures can
be implemented during
program design/approval?
Source surveys
Emission inventories
SARA Title m data
Other State/national lists
Risk assessments
General authority
Authority to control
existing sources
Construction/Operating permit authority
Source registration
Authority for standards/guidelines
Autnonry to regulate area sources
Relationship to federal requirements
Review vs. screening of sources
Review of new sources only
Review of high risk sources
Source registration
Figure 1-1. Steps in Problem Definition.
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Once the S/L agency has defined the problem, the S/L is ready to design an
air toxics control program. As illustrated by Figure 1-2, there are several key points
to consider:
o Development of short- and long-term program goals and milestones -
The S/L decides what its air toxics program will accomplish and when.
Many S/L agencies have already accomplished this via EPA's Multiyear
Development Plan (MYDP) process.
o Development of communications strategy - Communications objectives
are denned, target audiences identified, communication techniques
selected and messages refined during this step. For reasons discussed
further in Sections 4.1 and 4.2, an effective communications strategy can
be a key to successful program development.
o Development of criteria for program evaluation - Beginning with the list
of program goals, the S/L decides how to measure progress made
toward each objective. Selecting measurable objectives, such as the
number of sources reviewed and controlled annually, is essential for
evaluating program progress and results.
o Selection of control approach - The key points to consider here are:
Will the agency base its program on promulgated rules or standards or
will it opt for a policy or informal guidelines? What will be the basis of
emission control (e.g., pollution prevention, control technology or
ambient impacts)? (See Section 1.2 for further discussion of control
approaches).
o Definition of program scope - The S/L considers its program goals, and
the information it has gathered, to determine which pollutants and
sources should be addressee first. Program scope includes issues such as
pollutant selection, source selection, and de minimis levels or
exemptions. (See Section 2.1 and 2.2 for further discussion).
o Assessment of resource requirements - This point is closely related to
program scope and stringency. More extensive source coverage and
review requires correspondingly greater staff resources. Phasing of
implementation can help fit the program to available resources. A
projection of necessary resources will likely be needed for budget
requestpurposes.
o Determination of program stringency - This includes establishing control
technology and/or emission reduction requirements for each source or
pollutant category. For the ambient impact element, methods for
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PROGRAM GOALS
COMMUNICATION
STRATEGIES
PROGRAM
EFFECTIVENESS
MEASURES
CONTROL APPROACH
POLLUTION PREVENTION
CONTROL
TECHNOLOGY
AMBIENT
IMPACTS
\
RISK ASSESSMENT/
RISK MANAGEMENT
PROGRAM SCOPE
RESOURCES
STAFF
PROGRAM
IMPACTS
PROGRAM
COMPLIANCE
PROGRAM
STRINGENCY
REPORTING
REQUIREMENTS
Figure 1-2. Designing an Air Toxics Program
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developing ambient guidelines are needed for each pollutant or category
of pollutants covered.
o Definition of staff responsibilities - The agency must decide who will do
what during program implementation and how many and what type of
personnel will be required for the job.
o Evaluation of program impacts - Agency procedures or policies may
require evaluation of the cost, economic, and administrative impacts of
the proposed program. This assessment may, in turn, influence program
design or implementation decisions.
o Determination of compliance schedules - The agency may decide during
program design that, while it would be appropriate to have the air toxics
control program broad in scope, it is not ready to tackle such a broad
scope immediately. If this is the case, the agency should use a phased
approach. Several agencies have adopted a phased approach with
defined compliance schedules. For example, high risk point sources
could be addressed first on a prioritized basis.
o Definition of reporting requirements - Reporting is often accomplished
through the existing permitting process because States have the authority
to request information from sources through permit applications and
source registrations.
1.13 Implementing, Enforcing and Evaluating the Program
At this point the S/L agency begins to put its control program into operation
through:
o Adoption of rules or policies - The agency's program is officially
launched with the approval of appropriate rules, guidelines, policies, or
procedures. Some S/L agencies have chosen to launch their initial
program through New Source Review while others have initiated more
comprehensive programs, including incorporation into the control
program of existing sources for several pollutants and source types.
o Resource acquisition - Resources include funding, equipment and staff.
For example, many S/L agencies have recruited staff with specialties
such as toxicology and chemistry. Some States finance their programs
through permit fees or other dedicated sources of revenue (e.g., vehicle
tag fees).
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Initiation of source-specific review - Depending on the program design,
this may mean starting permit application review and establishing permit
conditions and compliance schedules. For programs covering existing
sources, this may mean source registration and screening.
Initiation of information collection activities - For example, an ambient
monitoring network might be established to gather information on
conditions near high risk sources or in certain urban areas. Or, a source
survey (i.e., questionnaire) or review of SARA Title HI data could be
undertaken.
Coordination with other programs - For efficiency and enhanced
effectiveness, agencies coordinate with other programs such as ozone
control measures, community right-to-know, paniculate matter (PM,0)
control, etc. Often strategies can be designed to utilize additional
controls that simultaneously attain the goals and objectives of both air
toxics and criteria pollutant programs.
12 APPROACHING AIR TOXICS CONTROL COMPREHENSIVELY
This subsection presents guidance on selection of an agency's basic air toxics
control approach. This subsection will be useful to all S/L agencies, but especially
those in the process of designing their program.
1.2.1 Converging Program Approaches
Although some programs emphasize one control approach more than another.
the majority of S/L programs use a combined strategy made up of two basic program
elements: control technology and ambient impact requirements. A 1989 survey of
S/L programs by the State and Territorial Air Pollution Program Administrators and
the Association of Local Air Pollution Control Officials (STAPPA/ALAPCO) showed
that most agencies have adopted this more comprehensive approach to controlling air
toxics. Figure 1-3 illustrates the comprehensive approach.
Two primary factors underlie this strategy. First, each individual approach has
inherent limitations that can be offset by adoption of a combined approach. Second,
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• Technology-based
• Applies to specific source
categories and/or pollutants
Specifies minimum control
requirements
Achieves relatively
uniform reductions
• Promotes reasonable certainty
re: industry requirements
• Promotes pollution
prevention
- Health-based
- Applies to specific pollutants
- Standardizes air quality
levels
- Inhalation reference doses
- Ambient limits based on
on occupational levels
- Pollutant-specific
evaluations
•.s -V^ •.<
"^ <; '^VSX ^
Risk^e^nW^
_JX - S^-'^T^-"0^^^'^
RISK p!a»agein«f|i.t.
- Useful ior tailoring control
level to degree of health
concern
- Applicable to carcinogens
and noncarcinogens
- Based on target risk levels
- Can be used to establish
ambient limits
- Can be used to examine
post-control residual risks
Figure 1-3. Comprehensive Approach to Controlling Air Toxics Emissions
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because of the complexity of toxic air pollutants and emission sources, no one
regulatory approach is likely to address fully the air toxics problem.
Under a comprehensive approach, individual program elements are combined
into an integrated control strategy. The individual elements form a complementary
set of requirements. In this way, the program can effectively address sources of air
toxics that pose significant public health problems. For example, a program might
include a Best Available Control Technology (BACT) requirement plus ambient
impact requirements for new sources. In some cases, the optimum mix of controls is
achieved based on pollution prevention, control technology and ambient air
considerations. In others, a minimum level of control technology can be assured
before addressing issues regarding the acceptability of the remaining residual risk.
An advantage of a comprehensive approach is that it combines the best
features of the individual control elements. For example, the reasonable certainty of
emissions reduction of a control technology approach is combined with the site-specific
protection provided by an ambient impact approach. These advantages can be further
enhanced by use of risk assessment/risk management techniques to evaluate individual
sources.
A second advantage is that a comprehensive approach provides a framework
within which to address new pollutants or sources as additional information or
resources become available. Air toxics control is a long-term process. A first
generation program, for example, may focus only on certain pollutants emitted by a
limited number of sources. As a program evolves and matures, a second or third
generation program may cover a much broader array of pollutants and sources,
including area, nontraditional, and mobile sources. A comprehensive approach
provides a framework for responding to these and other problems as they are
identified.
1.2.2 Putting the Elements into a Comprehensive Framework
As mentioned above, a comprehensive approach combines individual program
elements into an integrated control program. To accomplish this, several key
1-10
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decisions are required Figure 1-4 illustrates the key factors to consider for each step
of a comprehensive approach.
For any type of program, whether it emphasizes control technology or ambient
impacts, one of the first major decision points is the selection of the basis for the
control program. At this point, an agency is faced with the decision of how, or
whether or not to combine control technology and ambient impacts requirements,
whether to incorporate risk assessment/risk management into the program, and how
to incorporate pollution prevention strategies into the program. It is important to
remember that decisions about the basis of the control program are closely related to
decisions about program scope, compliance schedules, and resources. The number
and type of pollutants and sources covered affect an agency's ability to implement a
particular type of program within available resources.
The following summarizes the different control approaches that, in combination,
establish the basis of a comprehensive air toxics control program.
Pollution Prevention Initiatives
Pollution prevention initiatives are those which reduce pollution at the source,
or which use environmentally sound recycling to prohibit releases of emissions,
discharges, and waste. Pollution prevention is one of EPA Administrator Reilly's
major environmental themes, signaling a change in policy from current EPA programs
whicn stress treatment and disposal after pollution has been generated. In the future,
EPA's emission regulations will be developed giving full consideration to prevention
potential.
Probably the most significant prevention opportunities in air programs involve
energy conservation and evaporation of volatile organic compounds (VOC). Examples
include promoting the use of low solvent coatings, handling and storage of volatile
fuels, and regulations that stimulate recycling of wastes to combustion units. The
emission regulations EPA has set for over 40 source categories of VOC emphasize
process modifications, reformulation, prevention measures, and recycling.
1-11
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Key Decisions
Factors to Consider
PROGRAM GOALS
AND OBJECTIVES
Reduce
PROGRAM
TYPE/BASIS
CONTROL
TECHNOLOGY
ELEMENT
AMBIENT IMPACT
ELEMENT
RISK ASSESSMENT/
RISK MANAGEMENT
PROGRAM SCOPE
REPORTING
•REQUIREMENTS
RESOURCE
REQUIREMENTS
PROGRAM
COMPLIANCE
Reduce cancer risks
Mitigation of fuuue neks
Control of specific sources/pollutants
Pollution prevention
Comprehensive versus limited
Guidelines versus pi'f^'Mgitrri
rales or standards
Preventanve vs. Curaave
Pollution prevention
New vs. easting sources
Carcinogens vs. noncsranogens
Major vs. minor sources
BACT vs. LAER (new)
RACT vs. BACT (existing)
Specific teccaoiogies vs.
percent reductions
Appropriateness of occupational limus
Inhalation Rfd'i
Risk-based AAL's
Multiple lources/poiluunts
vs. single source/single pollutant
Accepubie risk level
Identificitioo of bi£h "^ poflutmts
Risk urget versus sundnds
Residual risJa after control
Specific source categories
PoUutamx covered
Point vctxus cxea sources
Oenriniims size oaoff:
New vcnus eusaoa source
New and icnewal penmi applications
Source mspec&oc
Operating du
Agency requests to sources
SARA Tulc ffi
PCZIXQl ICV1CW
Digpcnrion modeling
Rick ttKumcnt
Ambient mwriionng
Control technology cvtluaioa/coKting
courcci
New «nd modified cotaces
Point sources
Are* sources vs. aanor point sources
Nootrtditionil sources
Schedule for complimce
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Pollution prevention is also an important facet of control in a comprehensive
S/L air toxics program. In conjunction with considering "end-of-pipe" control
technologies, process modifications, reformulation, prevention measures, and recycling
can also be considered. As discussed below, some S/L agencies (e.g., Maryland,
Nebraska, Kentucky) include pollution prevention in their definitions of BACT for
toxics.
1222 Control Technology Element
Under the control technology element, minimum control technology or
emissions reduction requirements are established. These may be applied across-the-
board or to specified source categories and/or pollutants. This element is
summarized in Table 1-1.
Control technology requirements may be in the form of pollution prevention
initiatives, specified technologies or control methods, a generic percent reduction
requirement, an emission limit, specified operating practices, or a combination thereof.
The label given to the control technology requirement differs from State-to-
State. For example, Maryland requires that most new sources use best available
control technology for toxics, or "T-BACF. Wisconsin has a "Lowest Hazardous
Emission Rate" (LHER) requirement for sources of known human carcinogens and
"Best Commercially Available Control Technology" (BCACT) requirement for sources
of suspected human carcinogens. New York and Texas require new sources to meet a
BACT requirement. Irrespective of the name, the most important ingredients of a
control technology requirement are its stringency and the sources to which it applies.
Stringency and applicability requirements vary considerably among S/L programs, and
may vary according to the toxicity of the pollutant. Many S/L programs with a
control technology emphasis apply the most stringent level of control to new sources,
and to the highest priority pollutants, such as carcinogens. Maryland, on the other
hand, applies their top-down T-BACT requirement on a case-by-case basis to all new
sources of toxics, taking into consideration the toxicity of the pollutants emitted and
the cost of control, among
1-13
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TABLE 1-1. SUMMARY OF CONTROL TECHNOLOGY ELEMENT
Main Features:
o Categorical control technology or emission reduction
requirements, or
o Case-by-case BACT requirement with or without a
minimum emission reduction level
o Requirements typically apply independent of ambient
impacts or risks
Advantages:
o Ensures minimum degree of control
o Achieves equitable emission reductions within
categories
o Provides less ambiguous requirements for affected
facilities
o Encourages pollution prevention
o Is technology -forcing
Decision Points:
example i-anguage:
(1) Rigor/stringency of control requirement
_ (e.g.,definition of BACT)
(2) Relationship to other program elements (e.g.,
residual risk issues)
(3) Process for making control technology decisions(i.e.,
generic criteria or case-by-case)
(4) Applicability to new and/or existing sources
(5) Applicability to pollutant types (e.g., carcinogens)
Wisconsin
* WI - NR 445.02 (4)
(4) "Best available control technology" means an emission
limit for a hazardous air contaminant based on the
maximum degree of reduction practically achievable as
specified by the department on an individual case-by-case
basis taking into account, energy, economic and
environmental impacts and other costs related to the
source.
Kentucky
* KY - KAR 63:022 Section 2(4)
(4) "Best available control technology" means emissions
limitation based on the maximum degree
1-14
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TABLE 1-1. SUMMARY OF CONTROL TECHNOLOGY ELEMENT (CONTINUED)
of reduction for each pollutant listed in Appendix B to this
regulation which would be emitted from any proposed
affected facility which the cabinet, on a case-by-case basis,
taking into account energy, environmental and economic
impacts and other costs, determined to be achievable for
such facility through application of production processes or
available methods, systems, and techniques for control of
such pollutant In no event shall application of best
available control technology result in the emission of an air
pollutant which would exceed the emissions allowed by any
applicable standard under Title 401, Chapters 57 and 59, or
40 CFR pans 60 and 61.
Maryland
« MD - COMAR 10.18.15.01 B(3)
(3) "Best available control technology for toxics" (T-BACT)
means that production technology, emissions control
technology, operation and maintenance procedures, other ~
measures, or combinations of them that results in the
maximum degree of emission reduction that the
Department determines, on a case-by-case basis, is
achievable by an installation, for each toxic air pollutant
discharged, taking into account the potency and toxicity of
each toxic air pollutant discharged as well as technical and
economic feasibility.
Nebraska
* NE - Title 129, Ch. 1 013
013 "Best Available Control Technology" means an emission
limitation or a design, equipment, work practice,
operational standard or combination thereof, which results
in the greatest degree of reduction of a pollutant, as basis,
taking into account energy, public health, environmental
and economic impacts and other costs.
1-15
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other factors. As in many other States, Maryland applies its control technology
requirement first, independent of the ambient impacts.
Development of a program including a control technology element involves at
least three major decision points. These are illustrated in Figure 1-5. The three
decision points are:
(1) the rigor or stringency of the control requirement,
(2) the relationship to other program elements, (i.e., ambient impacts and
residual risk analyses) and
(3) the process for making control technology decisions (e.g., whether to
establish generic requirements/guidelines or use a case-by-case
approach).
1. Rigor/Stringency of Technology Requirement. The first decision point
involves the rigor or stringency of the requirement. The level of stringency varies
among agencies and, in fact, may vary from one source to another. The level of
stringency does not ^vary so much in the formal definition of BACT. Indeed, most
agencies seem to rely on a fairly standard definition where BACT determinations are
made on a case-by-case basis and usually consider cost. Instead, the variation is in
which sources and for what pollutants BACT is required. It is also likely that the
stringency of the case-by-case BACT determinations varies between agencies, but that
possibility has not been investigated.
Although formal definitions of BACT are fairly consistent, they may be used
differently in practice. For example, the BACT guidelines developed by the Northeast
States for Coordinated Air Use Management (NESCAUM), .and Maryland's T-BACT
approach use top-down BACT where a permit applicant must first identify the most
stringent control possible (usually referred to as the lowest achievable emission rate or
LAER). and then quantify emissions. At this step, no technically feasible alternative
is ruled out. The starting assumption for the top-down BACT approach is that the
most stringent control possible is BACT. The burden of proof for applying a less
stringent control requirement rests with the applicant
1-16
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Other S/L agencies set a percent emission reduction as BACT. For example,
New York has a BACT requirement for all sources of pollutants classified as highly
toxic and generally considers BACT to result in 99 percent control. Similarly,
New Jersey requires BACT for sources that emit any of the toxic volatile organic
compounds that the State regulates and considers this to be 99 percent control. For
toxic particulates, 99 percent control is expected from existing sources and 99.9
percent for new sources.
Related to the use of BACT are the requirements for reasonably available
control technology (RACT) and the lowest achievable emission rate (LAER). A
RACT requirement is typically less stringent than BACT, while LAER is more
stringent.
Table 1-2 lists citations regarding control technology in several State air toxics
regulations.
A brochure about EPA's Control Technology Center (CTC), which can provide
information on control technology options and on how various S/L agencies have
determined BACT and LAER for various sources, can be obtained by calling the
CTC at (919)-541-0800.
2. Relationship to Other Program Elements. A second decision point
involves determining the relationship between the control technology requirement and
other reviews and requirements included in the program. Specifically, linkage to the
ambient impacts element, both procedurally and conceptually, must be determined.
Will sources be required to meet an AAL requirement in addition to the control
technology requirement? Will sources be analyzed for their residual risks and become
subject to additional controls or other changes before approval if they do meet the
target risk level after meeting the control requirement? Most S/L agencies with a
control technology component to their program couple it with an ambient impact
component or use risk assessment techniques to evaluate the residual risks posed by a
source after applying controls (e.g., New Jersey, Maryland, Texas).
1-18
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TABLE 1-2. CITATIONS TO CONTROL TECHNOLOGY REQUIREMENTS
Control Requirements: Control Technology-Based
CT - Section 22a-174-29(d)
KY - 401 DAR 63:021 Section 3(2)
KY - 401 DAR 63:022 Section 3(2)
MD - COMAR 10.18.15.05 A,B,C
MD - COMAR 10.18.15.05 B
NE - Title 129, Ch.6 007
NV - 445.719
NV - 445.7195
NY - 6 NYCRR 212.2(c)
NY - 6 NYCRR 212.4(d)
NY - 6 NYCRR 212.9, Tables 1,2,3,4
OK - 3.8.4(c)(l)
OK - 3.8.4(d)
VA - 120-04-0303
VA - 120-05-0303
WI - NR 445.04(3)(a) and (3)(b)
WI - NR 445.04(4)
WI - NR 445.04(5)(c)
WI - NR 445.05(3)(a) and (3)(b)
WI - NR 445.05.(5)(e)
Definitions: Best Available Control Technology
KY - 401 KAR 63:022 Section 2(4)
MD - COMAR 10.18.15.01 B(3)
NE - Title 129, Ch.l 013
WI - NR 445.02 (4)
1-19
-------
o Relationship Between BACT and Ambient Requirements. Several
agencies require sources to apply BACT and then to meet acceptable
ambient levels as well, while some either (1) allow sources to choose
between a BACT requirement or an ambient level, or (2) require
sources to apply BACT if the source cannot meet the agency's
acceptable ambient level In the first case, where BACT does not
achieve ambient impact objectives, options that are technology-forcing,
include pollution prevention or limiting operation are also considered.
o BACT Requirement for New Versus Existing Sources. A BACT
requirement for a source not yet constructed is much different from an
economic standpoint than a BACT requirement for an existing source
that has applied for a renewal of an operating permit Accordingly, few
agencies apply rigorous top-down BACT requirements to existing sources,
and those that do generally combine the technology requirements with
acceptable ambient levels and/or risk assessment requirement.
o BACT Requirements for Different Toxicity Classes. Another issue
relating to the stringency of BACT requirements is the pollutants that
trigger application of BACT. Several agencies require BACT, or even
the more stringent LAER only for emissions of carcinogens. Some
agencies require BACT on all new sources, but only on sources of
carcinogens for existing sources.
o Emissions Sources. At least one State (Wisconsin) makes a distinction
between which emission units within a facility must install BACT or
meet LAER. In this case, the emission units at the facility that emit the
greatest amount of the pollutant must install BACT (or meet LAER in
the case of known human carcinogens). If the pound per hour emission
rate given in the regulation is not met for the facility, then additional
units must install BACT (or meet LAER) until the emission rate is met.
o Residua] Risks. The issue concerning residual risk is "What additional
source requirements should apply if an unacceptable residual risk
remains after applying BACT or other applicable controls?" In this case,
the agency must carefully weigh post-BACT options. A likely concern in
such cases will be the potential economic consequences of various post-
BACT options. As a result, S/L agencies will need to evaluate the cost-
benefit of reducing risks to target levels, in the face of severe economic
consequences, a compliance schedule may need to be adopted that
would achieve risk targets within a specified period of time in lieu of
imposing unacceptably high costs or economic consequences (i.e., plant
shutdown) in order to achieve immediate compliance.
1-20
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3. Process for Making Control Technology Decisions. A third decision point
involves how control technology decisions are made. The question is whether such a
requirement should apply to individual source categories or pollutants, or whether a
case-by-case approach should be used. A categorical approach may require somewhat
more time initially. However, once established, control technology requirements or
guidelines can facilitate the review of individual source applications. On the other
hand, a case-by-case approach provides greater flexibility to handle unique situations.
However, it rnay involve more engineering evaluation during the review of permit
applications.
1.2.2.3 Ambient Impact Element
Under the ambient impact element, health-based ambient concentration limits
are used to establish control requirements for individual sources. This element is
summarized in Table 1-3.
The main feature of the ambient impact element is that it relies on ambient
concentration values as a control mechanism and therefore, control is based on
possible health effects rather than control technology. The objective in setting an
acceptable ambient level (AAL) is that it will be stringent enough to protect the
public from exposure to concentrations that would result in unacceptable health
effects. Under this approach, AALs have been established as either screening levels,
standards, or guidelines. This approach is premised on the assumption that
"acceptable" levels of exposure can be defined for individual toxic compounds in the
ambient air.
There are two major decision points in the design of a program that includes
an ambient impact element. The decision points are illustrated in Figure 1-6. They
are related to:
(1) The use of occupational levels
(a) which uncertainty factors to apply, and
(b) which averaging times to use.
1-21
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TABLE 1-3. SUMMARY OF AMBIENT IMPACT ELEMENT
Main Features:
Advantages:
Decision Points:
o Health-based acceptable ambient levels (AALs) are
used as basis for control requirement
o Occupational levels, inhalation reference doses, or
risk-based AALs commonly used
o AALs may be ambient standards or screening
guidelines
o Source controls based on health considerations
o Considers characteristics/toxicity of individual
pollutants
o Considers ambient impacts of individual sources
o Can use lexicological research done by others
(1) Whether to use occupational levels or
chemical-specific values
(2) What uncertainty factors to apply
(3) What averaging times to use
Example Language:
Connecticut
* CT - Section 22a-174-l
"Maximum allowable stack concentration" or "MASC" is the
maximum allowable concentration of a "hazardous air
pollutant" hi the exhaust gas stream of a "source" at the
"discharge point." (MASC is based on a "Hazard Limiting
Value" which is derived from an uncertainty factor applied
to an occupational standard.)
Kentucky
*KY - 401 KAR 63:021 Section 2(3)
(3) "Threshold ambient limit (TAL)" means the
concentration level in the ambient air of a toxic air
pollutant, calculated pursuant to Appendix B to this
regulation. (Appendix B lists 736 pollutants, and gives the
averaging time and a value for each. The Threshold
Ambient Level is calculated by dividing the given value by
the hours of emission of the substance per week from the
source.)
1-22
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TABLE 1-3. SUMMARY OF AMBIENT IMPACT ELEMENT (Continued)
Maryland
« MD - COMAR 26.11.15.01 B(l)
(1) "Acceptable ambient level" (AAL) means a
concentration of a toxic air pollutant in the atmosphere
that the Department determines will provide a margin of
safety to protect the public health from toxic,
noncarcinogenic effects that may be caused by the toxic air
polluiant and that is used to evaluate :he air quality
impacts of all premises within a 5 kilometer (3.1 mile)
radius. AALs are listed in Regulation ,13, below.
Oklahoma
* OK - 3.8.2 (2)
(2) Maximum Acceptable Ambient Concentration (MAAC)
means the maximum allowable twenty-four hour average
concentration, in ambient air, of a toxic air contaminant.
1-23
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(2) Alternative approaches
(a) inhalation reference doses concentrations (Rfcs),
(b) risk-based ambient levels, and/or
(c) chemical-specific evaluation.
1. Occupational Levels. The first decision point is whether or not to use
occupational levels as a basis for ambient limits. Acceptable ambient levels have
been established by some S/L agencies by applying an uncertainty factor to an
occupational standard for a particular pollutant. This approach has typically been
chosen because of two main advantages. First, for many pollutants, occupational
standards are the only health-based standards that are readily available. Secondly,
resource limitations have not allowed chemical-specific studies to be undertaken.
On the other hand, there are several disadvantages to using occupational levels
to set ambient limits. For example, Threshold Limit Values (TLVs) are occupational
levels established by ACGIH. They are based on a variety of health effects including
cancer and acute and chronic noncancer effects. However, the TLV is set to protect
a healthy worker population, and as such is based on an 8 hour/day, 40 hour/week
exposure (which allows for recovery between exposures). The TLV does not take into
account exposures that may be of a prolonged duration (such as ambient exposure),
or consider sensitive populations, such as children or the elderly. The application of
an uncertainty factor to the TLV is intended to lower the TLV to a level where
prolonged exposure and sensitive populations are considered.
Exposure time-adjustment factors are typically applied to convert an
occupational level from an 8-hour exposure to a 24-hour exposure. A second
uncertainty factor is also applied to account for the sensitivity of the general
population as compared to the healthy worker assumption used for the occupational
limit, and to account for uncertainties in the scientific basis of the
standards/guidelines. Different uncertainty factors may also be applied to different
groups of chemicals in recognition of their relative toxicity. For example, one factor
might be used for known human carcinogens, another for probable human
1-25
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carcinogens, a separate factor for chronic systemic toxicants, and another for acute
irritants.
Averaging times, or the length of time over which a source is allowed to
average its contribution to the ambient concentration, also have a significant impact
on the stringency of the AAL. For example, an ambient level of 10 ug/m3 with an
averaging time of 8 hours is more stringent than an ambient level of 10 ug/m3 with
an annual averaging period.
Many agencies choose averaging periods based on the health effects of
particular pollutants and, consequently, use more than one averaging period in their
program. For example, an annual averaging period is frequently used for carcinogens
and other pollutants with effects associated with long-term, chronic exposure, while a
1-hour averaging time is often used for pollutants associated with health effects
occurring from short-term, acute exposures. Averaging periods reported in the
STAPPA/ALAPCO survey ranged from 3 minutes to annual. The most commonly
used averaging times are annual, 24 hours, 8 hours, and 1 hour.
The relationship between AALs and averaging times is important to the overall
stringency of the control requirement An averaging time says, in effect, that
excursions above the AAL are permissible provided that they are compensated for by
equivalent excursions below the AAL over the period of the averaging time. In
determining the stringency of the AALs and their associated averaging times, an
agency has to address whether an AAL may be exceeded for some period of time. In
the case of some very acutely toxic pollutants, a short averaging time (e.g.,
15 minutes) is necessary to ensure that short-term releases do not go uncontrolled.
One question frequently asked is how to compare ambient levels that have the
same uncertainty factor, but different averaging times. To perform this comparison,
certain emission characteristics and dispersion assumptions must be made. In a study
done by the Commonwealth of Virginia, various safety factors were converted to an
equivalent basis for direct comparison of safety factors and averaging times. The
results of this analysis are summarized in Table 1-4. As shown in the table, the
uncertainty factor and averaging time both affect the stringency of the AAL. For
example, a TLV/100 level averaged over an 8-hour period is more stringent than a
TLV/300 level averaged on an annual basis.
1-26
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TABLE 1-4.
EQUIVALENT UNCERTAINTY FACTOR FOR 24-HOUR
AVERAGING TIME
AVERAGING
TIME
UNCERTAINTY
APPLIED TO TLV
EQUIVALENT UNCERTANITY
FACTOR FOR 24-HOUR
AVERAGING TIME a
8 hour
24 hour
1 hour
24 hour
24 hour
24 hour
annual
8 hour
24 hour
annual
24 hour
30 minutes
8 hour
24 hour
8 hour
24 hour
1 hour
24 hour
annual
24 hour
annual
24 hour
annual
10
10
40
40
30
42
42
50
50
50
60
100
100
100
200
200
300
300
300
420
420
1000
1000
20
10
200
40
30
42
10
100
50
10
60
1000
200
100
400
200
1500
300
60
420
84
1000
200
Based on calculations by the Commonwealth of Virginia, under typical conditions and non-varying
emission rates:
The highest 1-hour concentration of a pollutant = 25 X ANNUAL MEAN
5 X 24-HR MEAN
2JX 8-HR MEAN
For example, if the annual mean concentration is 10, the 24-hour mean would be 50, the 8-hour
concentration would be 100, and the highest 1-hour concentration would be 250.
1-27
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2. Alternative Approaches. There are alternatives to using the occupational
level/uncertainty factor approach. These include using EPA's reference concentrations
(RfCs), developing risk-based AALs for carcinogens using EPA's unit risk factors, or
evaluating health effects on a chemical-specific basis and basing the AAL on that
evaluation.
RfCs, developed by EPA, are based on a review of health effects data and
represent an annual average concentration below which a long-term exposure is unlikely
to result in adverse health effects. Consequently, they are an alternative to using
occupational standards as screening levels for ambient impacts. As of June 30, 1990,
RfCs have been developed and verified for 19 chemicals. Many more (primarily for
chemicals listed in Clean Air Act amendment legislation) are currently under review by
EPA's Reference Concentration Verification Work Group. The pollutants for which
RfCs have been developed are listed in Table 1-5.
For more information on inhalation RfCs, call the Air Risk Information Support
Center (Air RISC) hotline at (919) 541-0888.
A number of S/L agencies (e.g., Connecticut, Rhode Island) have developed
AALs for carcinogens using unit risk factors developed by EPA's Human Health
Assessment Group (formerly the Carcinogen Assessment Group). To convert a unit risk
factor to an AAL, the agency first needs to determine a target risk level that will be the
basis of evaluation. The most commonly used measure of acceptable risk is the
maximum individual risk (MIR) of the most exposed individual (MEI). Risk to the MEI
means the risk of contracting cancer associated with the highest ambient concentration
to which anyone would be continuously exposed over a 70-year lifetime. According to
the 1989 STAPPA/ALAPCO survey of S/L agencies, most agencies that use risk
assessment have an acceptable risk level of either one in one million (i x 10"6), or one
in one hundred thousand (1 x 10'5). An example calculation showing how to convert a
unit risk factor into an AAL is shown hi Table 1-6. Pollutants for which inhalation unit
risk factors have been developed are listed in Table 1-7.
1-28
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TABLE 1-5. LIST OF POLLUTANTS FOR WHICH INHALATION
REFERENCE CONCENTRATIONS (RfCs) HAVE BEEN DEVELOPED
(AS OF JUNE 30, 1990)
CHEMICALS WITH VERIFIED RfCs
Acetaldehyde
Acrolein
Bromomethane
Carbon disulfide
Cumene
1,4-Dichiorobenzene
Dichloromethane (methyiene chloride)
Dimethylamine
Epichlorohydrin
Hydrogen chloride
Hydrogen suifide
Hexane
Mercury (inorganic)
Nitrobenzene
Propylene glycol monoethyl ether
Tetrahydroniran
Toluene
Xylene
1-29
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TABLE 1-6. EXAMPLE CALCULATION OF AAL FROM UNIT RISK FACTOR
1. URF = (4.8 x 10"3) = the probability of dying of cancer following
70-years of continuous exposure to 1 ug/nf of a particular chemical in
the ambient air.
2. State's ARL = 1 x 1(T5
3. URF x AAL = ARL
4. AAL = ARL
URF
5. AAL = 1 x 10 "5
4.8 x 10
6. AAL = 0.00208 ug/m3
Where: URF = unit risk factor
ARL = acceptable risk level
AAL = acceptable ambient level
1-30
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TABLE 1-7. POLLUTANTS WITH EPA INHALATION UNIT RISK FACTORS
Acetaldehyde
Arsenic
Benzene
Beryllium
Cadmium
Chloroform
Coke oven emissions
1,1-Dichloroethylene
Ethylene dibromide
Formaldehyde
Hexachlorobenzene
Nickel
- Refinery dust
- Subsulfide
Tetrachloroethlyene
Vinyl chloride
Acrylonitrile
Asbestos
Benzo(a)pyrene
1,3-butadiene
Carbon Tetrachloride
Chromium (VI)
1,2-Dichloroethane
Epichlorohydrin
Ethylene oxide
Gasoline (marketing)
Methylene chloride
Propylene oxide
Styrene
2,3,7,8-TCDD
Trichloroethylene
1-31
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For more information on unit risk factors, call the Air RISC hotline at (919)
541-0888.
Evaluating health effects on a chemical-specific basis and deriving AALs from
the evaluation is a resource-intensive effort The advantage of this type of study is
that the AALs that are derived are health-based numbers that can consider cancer
and noncancer effects and are protective of public health (including sensitive
populations). The Massachusetts Department of Environmental Quality Engineering
has completed such a study (a 5-year effort) and compiled a document entitled The
Chemical Health Effects Assessment Methodology and the Method to Derive
Acceptable Ambient Limits (CHEM and AAL). The document describes the
methodology used to review the scientific data for four categories of health effects for
each chemical. The health effects review results in a "hazard score" being assigned to
each chemical for each of the four health endpoints. The hazard scores are used to
adjust the occupational level downward to account for factors that include chronic
exposure, sensitive populations, and noncancer effects. Because the hazard scores are
different for each chemical, the occupational levels are "customized" to form the basis
for the AAL,
As of this writing, Massachusetts has assigned AALs to approximately 105
chemicals and expects their chemical-by-chemical evaluation to be an ongoing process.
Another issue related to the stringency of any ambient-based control
requirement is whether the source must take into account background concentrations
of the pollutant in question, or if the source must simply be concerned with its own
contribution to the ambient concentration. From the standpoint of public health
protection, background concentrations are very important. From a source's point of
view, however, if background concentrations are taken into account, the source is
forced to use tighter control measures when the level of the pollutant in the ambient
air may not be attributable entirely to the source. Probably because of the difficulty
involved in measuring background levels, very few agencies consider background
concentrations in evaluating whether or not acceptable ambient levels are being met.
1-32
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Because of the impact that the consideration of background concentrations can have
on control decisions, this may be a factor to include in a "later generation" of a
control program.
Table 1-8 provides citations to S/L regulation containing ambient impact
requirements.
1.2.2.3 Risk Assessment/Risk Management
1. Overview. Risk assessment is the process of determining the potential
adverse health effects of human exposure to environmental hazards. Risk assessment
includes four steps:
(1) Hazard identification. A qualitative risk assessment, hazard identification
attempts to answer the question: Does exposure to a specified hazard cause
adverse health effects (such as cancer) in humans? A qualitative determination
of risk may entail some interpretation, such as whether animal carcinogens are
presumed to be human carcinogens, or whether benign tumors in animals
represent potential human carcinogenicity.
(2) Dose-response assessment. This is the process of characterizing the
relationship between the dose of a toxicant received, and the incidence of
adverse health effects in exposed populations. This step usually requires
extrapolation of data from animal studies to humans and from high doses to
low doses.
(3) Exposure assessment. This is the process of measuring or estimating the
intensity, duration, and frequency of human exposure to a toxicant.
(4) Risk characterization. Tnis is the final step of risk assessment and is the
quantitative process of estimating the magnitude of the public health problem
that results from the hazard. It involves the combination of the hazard
identification, dose-response assessment, and the exposure assessment. Thus,
the final expressions of health risks are derived in this step.
Risk management is the decision-making process in which an action is taken or
a policy developed once a risk has been determined to exist. It integrates the risk
assessment with technical, political, social, and economic issues. Risk management is
also a means of setting priorities among possible actions for a toxicant or source.
Risk management must take into account the uncertainties associated with various
assumptions and judgments made in each step of the risk assessment process.
1-33
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TABLE 1-8. CITATIONS TO AMBIENT IMPACT REQUIREMENTS
Control Requirements, Ambient Concentrations-Based
CT - Section 22a-174-29(b)(3) and (b)(4)
KY - 401 KAR 63:021 Section 3 and Appendix B
KY - 401 KAR 63:022 Section 3 and Appendix B
MD - COMAR 10.18.15.06
MD - COMAR 10.18.15.07 B(2)
MD - COMAR 10.18.15.07 C(2)
NV - 445:7195
NV - 445:720
OK - 3.8.4(b),(c),(d),(e)
RI - 22.5.4
VA - 120-04-0304
VA - 120-05-0304
WI - NR 445.04
WI - NR 445.05 (l)(a),(b);(2)(a),(b)
WI - NR 445.05 (4)(a),(b)
Control Requirements: Ambient Concentrations - Setting
Acceptable Concentrations
CT - Section 22a-174-29(a)(2) and (a)(3)
CT - Section 22a-174-29(c)
KY - 401 KAR 63:021 Appendix A
KY - 401 KAR 63:022 Appendix A
MD - COMAR 10.18.15.08 A
MD - COMAR 10.18.15.09 D(l),(2)
NV - 445.718
NV - 445.7185
OK - 3.8.4(f)
VA - 120-04-0304
VA - 120-05-0304
WI - 445.04 (l)(a) and (l)(b)
WI - 445.04 (2)(a) and (2)(b)
WI - 445.05 (l)(a) and (l)(b)
WI - 445.05 (2)(a) and (2)(b)
WI - 445.05 (4)(a) and (4)(b)
1-34
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There are no fundamental differences between cancer and noncancer risk
assessment/risk management issues. The major difference between the two is that
unit risk factors are available for carcinogens, thus giving the S/L agency a method to
derive a single number at the acceptable risk level. This makes cancer effects easier
to deal with compared to noncancer effects. The development of inhalation Rfcs
(discussed in Section 1.2.2.2), will make noncancer risk assessment much more
accessible to S/L agencies.
The main advantage of using risk assessment/risk management is that the end
result is an indication of relative health risks and a uniform threshold of protection
for the public. Risk assessment/risk management also allows the S/L agency to take
into account variations in the economics associated with individual sources in setting
control requirements.
The main disadvantage of using risk assessment/risk management is the
difficulty in determining an "acceptable" risk level. This difficulty is due to the
uncertainties associated with the many assumptions that must be made regarding
population exposure, dose-response, hazard identification, etc. The lexicological
resources required to evaluate individual facilities is another drawback. As described
in Section 1.2.2.2, according to the 1989 STAPPA/ALAPCO survey of S/L agencies,
most agencies that use risk assessment/risk management have an acceptable risk level
of either one in one million (1 x 10 "*), or one in one hundred thousand (1 x 10"5).
A decision closely associated with the determination of the target or acceptable
risk level is whether the risk level should be a screening tool or a regulatory
requirement. Several S/L agencies use nsk targets as a screening value for triggering
a more detailed evaluation of a source. Others use risk levels as an "action" level. If
the risk level is used as an "action" level (i.e., plant shutdowns are possible), an
appeal process will probably be necessary to allow the source the chance to, for
example, provide better modeling data or initiate actions to resolve the problem.
An issue here is whether the burden to undertake risk assessments should be
placed primarily on industry or whether the agency will conduct source-specific risk
assessments. The State of Maryland requires the source to perform the risk
assessment, an approach that Maryland feels saves the agency significant resources.
1-35
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Risk assessment/risk management comes into play with both control technology
requirements and ambient impact requirements. For example, residual risk after the
application of controls is an issue addressed by risk assessment/risk management, as is
the use of inhalation Rfcs or unit risk factors as a basis for setting AALs.
2. Risk Assessment/Risk Management Guidance. Risk assessment
guidelines relating to environmental carcinogens, mutagens, developmental toxicants,
chemical mixtures and estimating exposure were issued by EPA on
September 24, 1986 (51 FR 33992). The guidelines were developed to promote high
technical quality and Agency-wide consistency in the risk assessment process.
The guidelines were developed partly in response to a 1983 National Academy
of Sciences publication entitled "Risk Assessment in the Federal Government:
Managing the Process," which recommended that Federal regulatory agencies establish
risk assessment guidelines. An EPA task force, convened by then EPA Administrator
William D. Ruckelshaus to study ways to improve the scientific foundation for Agency
regulatory decisions, accepted the recommendation, and work on the guidelines began
early in 1984. As announced on August 26, 1988, some of the guidelines are
currently being revised (53 FR 32656). Additional guidelines are also under
development for various topics, including noncancer effects, reproductive toxicity, and
exposure-related measurements.
A second source of information is the NATICH report Qualitative and
Quantitative Carcinogenic Risk Assessment (EPA 450/5-87-003), which describes
EPA's risk assessment procedures for carcinogens. The Air Risk Information Support
Center (Air RISC) is also developing a guidance document on risk assessment that
will include noncancer risk assessment.
Another important source of assistance for risk assessment/risk management is
EPA's Integrated Risk Information System (IRIS). IRIS provides information on how
chemicals affect human health and is a primary source of risk assessment information
on chemicals of environmental concern. IRIS makes chemical-specific risk information
readily available to those who must perform risk assessments and also increases
consistency in risk management decisions. The health assessment information
contained in IRIS has been reviewed and agreed upon by two interdisciplinary review
1-36
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groups of EPA scientists who have extensive experience in risk assessment. This
Agency-wide agreement on risk information is one of the most valuable aspects of
IRIS.
The IRIS is an online database that may be accessed via EPA's electronic mail
(E-mail) system (available through DIALCOM, Inc.). The information in IRIS is
divided into two major components: (1) chemical-specific toxicity and regulatory
information, and (2) documentation providing instruction and explanation in support of
the system and the chemical files.
Each chemical file contains:
o verified reference doses based on noncancer health effects data
associated with chronic exposures,
o verified risk estimates for carcinogenicity,
o drinking water health advisories,
o summaries of selected EPA regulations, and
o supplementary data (e.g., acute toxicity information and physical-chemical
properties)
The database can be searched by chemical name or Chemical Abstracts Service (CAS)
number. Over 260 chemicals are represented.
For more information on IRIS, call IRIS User Support at (513) 569-7254 (EPA
Cincinnati).
A fourth source of assistance is EPA's Air RISC. One of Air RISC's goals is
to serve as a focal point for disseminating information on health, exposure, and risk
assessments for toxic pollutants.
1-37
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For a brochure describing Air RISC activities call the Air RISC hotline at (919)
541-0888.
A more complete list of primary sources of EPA information on risk
assessment is provided in Table 1-9.
1-38
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SECTION 2.0
MAKING CRITICAL DESIGN CHOICES
-------
2.0 MAKING CRITICAL DESIGN CHOICES
Highlights of This Section
Defining the scope of an air toxics program is a critical step
in program development which is closely related to program
stringency and other design and implementation issues.
Program scope includes pollutant selection, source category
selection, existing source coverage, size and emission cutoffs.
program phasing, and resource allocation issues.
A variety of resources are available to assist S/L agencies with
program scope decisions.
Defining the scope of a program is a critical step in the program development
process. Program scope decisions are critical for several reasons, including the
following:
o Program scope decisions affect the ability of an agencv to address air
toxics goals. For a program to be successful, the number of pollutants
and sources selected for regulation should be realistic and in keeping
with the program's goals. Defining program scope too narrowly,
however, may result in less public health protection than desired.
o Program scope decisions influence whether program goal." can be
achieved within available resources. An overly expansive program, for
example, may subject more sources to regulation than an agency can
handle within available resources. If staff and other resources are
overloaded, the chance of achieving the program's goals is likely to
diminish.
o Program scope decisions determine the size and nature of the regulated
community. Program scope decisions can greatly influence the politics of
program approval by defining the nature and extent of the potential
opposition to a program.
There are at least six main topics to consider in defining the scope of
an air toxics program. They are:
2-1
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(1) selection of pollutants,
(2) selection of source categories,
(3) regulation of existing sources,
(4) selection of size and emission cutoffs/exemptions,
(5) timing/phasing of program coverage, and
(6) resources required.
The following subsections discuss each of these program scope decision points and the
approaches used by S/L agencies with operating programs.
2.1 SELECTING POLLUTANTS OF CONCERN
2.1.1 General Approaches
Two general approaches have been taken by S/L agencies in selecting toxic air
pollutants for review or regulation. Under one approach, a specific list of toxic air
pollutants is prepared. In the second approach, the agency addresses any substance of
concern. Each of these approaches has certain advantages and disadvantages.
One point to keep in mind when considering these two approaches is that,
under either approach, once the total number of pollutants regulated reaches a certain
level (e.g., 100-300), the number of additional sources covered may decline. Tnat is,
sources typically emit mixtures of pollutants. As a result, regulation of a specific
compound often results in simultaneous control of other compounds emitted by a
source. Consequently, listing hundreds of pollutants may not necessarily expand the
universe of regulated sources.
1. Specific List of Pollutants. One advantage of defining a specific list of
toxic air pollutants is that an agency may scope or limit their air toxics program
efforts and focus their resources on the selected pollutants. The amount of research
2-2
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required for identifying pollutant health effects associated with exposure to a specific
pollutant and emissions estimates would likely be less than for the open-ended
approach. Also, by defining a specific list of pollutants, the agency may, in effect, let
industry and the public know what to expect, and thereby create a more cooperative
atmosphere. Also, as mentioned above, control of one toxic pollutant is likely to
control several other types simultaneously without their specific regulation.
A disadvantage of defining a specific list of pollutants is that it may be difficult
to add new pollutants to the list Depending on legal and regulatory constraints, the
additions may have to be approved by an administrative board or by the legislature.
Some pollutants may inadvertently be left off the list, even though they represent a
significant potential for exposure and/or risk to the population. Conversely, the
longer the list becomes, the more the resources that must be devoted to data
collection and management. Finally, there may be public controversy over which
pollutants are selected and the rationale for their selection.
Regardless of the number of pollutants covered, it is important to incorporate
some degree of flexibility into the procedure for listing pollutants. Such flexibility
includes the ability to add or delete pollutants as new information becomes available,
and to prioritize in some manner regulatory efforts among various categories of
pollutants. Generic language can be included in the regulation (or policy) that
requires public notice, but not legislative action, before adding to or deleting from the
list. Some agencies note that such flexible procedures make the list of pollutants a
"living list" that may change considerably over time. For example, a flexible list would
make it easier to incorporate the approximately 200 pollutants contemplated for
regulation under proposed Clean Air Act amendments. Wisconsin is an example of a
State with a flexible list of regulated pollutants.
Generally .speaking, S/Ls have listed more than 100 pollutants in their
programs. There is widespread consistency in listing carcinogens; the choice and
number of noncarcinogens vary widely.
2. Open-ended Approach. Because of the disadvantages mentioned above,
some agencies have found it overly constraining to be limited to a specific list of
2-3
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pollutants. An advantage offered by an open-ended approach is that the agency can
regulate emissions of any toxic substance without undertaking a formal pollutant
selection process. Texas is an example of a State that has adopted this approach.
Texas regulates all noncriteria pollutants under their air toxics program.
One disadvantage of the open-ended approach is that the number of pollutants
addressed may become very large, such that research into health effects and emission
rates for such a large number of pollutants may have to be rather cursory. Data
collection and management may become resource-intensive. To address this concern,
Texas uses screening values based on available health effects information and on their
own staff evaluations when reviewing sources. Also, industry may not know what is
expected and may be concerned that an open-ended approach does not define a
specific control plan.
A combination of these two approaches has also been used. Typically, a
specific, yet flexible list is used for existing sources, and an open-ended approach for
new sources.
2.12 Steps for Selecting Pollutants.
To select pollutants, S/L agencies have proceeded through one or more of the
following steps:
1. Review chemical lists, such as Superfund Amendments Reauthorization
Act Title IQ (SARA Title HI), American Conference of Governmental
Industrial Hygienists (ACGIH), or lists from States with operating
programs,
2. Evaluate of the health effects of individual chemicals,
3. Evaluate of the expected occurrence of emissions of individual chemicals.
4. Seek internal assistance from divisions within the agency, and
5. Seek external assistance from such sources as Air RISC, IRIS, special
task forces or work groups.
2-4
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The methods are discussed independently of one another in this section. However, it
should be emphasized that pollutant selection actually involves completion of some or
preferably each of these steps. Table 2-1 summarizes the basis for selecting pollutants
by nine S/L agencies.
Step 1: Chemical Lists. There are many pollutant Lists that can be reviewed.
These include the list of 400+ hazardous chemicals listed under SARA Title HI
(listed in the Toxic Chemical Release Inventory reporting Form R - EPA-560/4-88-
005), and EPA's list of pollutants with unit risk factors (see Table 1-7), or for which
EPA has developed inhalation reference concentrations (see Table 1-5). Table 2-2
summarizes several groups that publish lists of carcinogens. In addition, as shown in
Table 2-1. S/Ls also incorporate pollutants from lists published by ACGIH, OSHA,
and NIOSH. The Data Base Report on State. Local, and EPA Air Toxics Activities
(EPA-450/3-89-29) published annually by the National Air Toxics Information
Clearinghouse (NATTCH), also has pollutant lists for the many States that set ambient
limits. In many cases, S/L agencies have used one or more of these lists in developing
their own list of toxic air pollutants. For example, North Carolina used an initial
screening process in which they identified pollutants that appeared on the lists of at
least five other States. This list, coupled with a review of North Carolina's emissions
inventory data, resulted in an initial list of 67 pollutants of concern. About 30 more
chemicals were subsequently added to North Carolina's list.
While lists of pollutants may be appropriate for the purpose for which they
were prepared, they should not necessarily be adopted m toto by another agency
because the types of industries and chemicals used differ from area to area. Other
States' lists can, however, serve as a good starting point for identifying pollutants of
initial concern. The derivation of any other State's list under consideration should be
checked by contacting the particular State to help determine the similarity between
industry and emission characteristics. Discussions with the appropriate personnel in a
State or local agency may also shed light on the rationale for pollutant selection used
by that agency. In other words, any list must be "customized" to meet a State or
local agency's own needs.
2-5
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TABLE 2-2. LISTS OF CARCINOGENIC COMPOUNDS
Group
Special Features
National Toxicology Program
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Also publishes results of Mutagenicity
and Teratogenicity testing.
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Research on Cancer
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scheme.
Occupational Safety and Health
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Publishes list of carcinogenic
compounds for hazard communication
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American Conference of Govern-
mental Industrial Hygienists
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Has proposed system to indicate
carcinogenic potential and potency.
Environmental Protection Agency
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Maintains list of unit risk factors
for certain carcinogens and has
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Agency for Toxic Substances
and Disease Registry
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Prepares risk assessments of hazardous
compounds at Superfund sites.
2-8
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Step 2: Expected Occurrence. A second step in selecting toxic air pollutants
is to evaluate the likelihood of a substance's use and emissions within a State or
region. This step identifies which pollutants are actually emitted or anticipated to be
emitted, but does not provide an indication of the pollutant's toxicity.
Several data sources are available to determine which pollutants are
used/emitted. These include literature reviews, questionnaires and SARA Title HI
reports, monitoring data, source testing/stack sampling, and the criteria pollutant
inventory.
Literature reviews.
Literature reviews are less expensive than some other sources of data. An
excellent starting point for a literature review is the Bibliography of Selected Reports
and Federal Register Notices Related to Air Toxics, published annually by NATICH.
The Bibliography is a three-volume set (plus an index) containing over 1850
bibliographic citations to reports and Federal Register notices related to air toxics
(EPA-450/5-87-005, EPA-450/5-88-005, EPA-450/3-89-25). To facilitate the use of the
Bibliography, citations are indexed by document type, pollutant name or class,
Chemical Abstract Service (CAS) number, source category and Standard Industrial
Classification (SIC) code, and sponsoring agency. (The index is EPA report number
EPA-450/3-89-25a.) The information contained in the bibliography is also available
through the NATICH on-line database.
For information on accessing the NATICH database online, call the Clearinghouse
Staff at (919) 541-0850.
Another important source of information on emissions sources for individual
pollutants and source categories is the Locating and Estimating Emissions series of
documents published by EPA This series of documents, known as the "L&E
documents", compiles available information on sources and emissions of various air
2-9
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toxics. The series includes documents on almost two dozen of the highest priority
pollutants, such as acrylonitrile, chloroform, formaldehyde, chromium, ethylene oxide,
and others. The documents contain information on emissions from production of each
chemical, emissions from its major uses, emissions from miscellaneous sources, and
source test procedures.
For information about the L&E documents, call (919) 541-5522, and request the
brochure, 'Tools for Estimating Emissions of Air Toxics".
Questionnaires to sources and SARA Title III reports.
Information from questionnaires or surveys on a facility's production, use and
storage of chemicals can indicate the types of pollutants expected to be emitted.
Surveys might be sent to all sources or specific surveys might be developed for
selected source categories. The EPA documents Compiling Air Toxics Emission
Inventories (EPA-450/4-86-010, currently being updated)- and Compilation of Air
Toxics Emission Inventory Questionnaires (EPA-450/4-88-008) provide useful
information on identifying potential sources of air toxics and designing questionnaires
for industry surveys.
Toxic chemical data from SARA Title HI Sections 312 and 313 inventories also
can be used for this purpose. By serving as a screening tool, a
proauction/use/storage evaluation may besi fit the needs of an agency just beginning
to develop an air toxics program. The results of the production/use/storage
evaluation could focus the efforts of follow-up, detailed data gathering. The use of
SARA Title III data or questionnaires is relatively less expensive than other data
gathering methods. Such data could also serve as the cornerstone for ac air toxics
emission inventory.
SARA Title III Section 313 requires EPA to establish a toxic release inventory
and to make the toxic emissions data available to the public through a national Toxic
Chemical Release Inventory (TRI) data base. The TRI data base is accessible by
2-10
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Chemical Release Inventory (TRI) data base. The TRI data base is accessible by
S/L agencies as well as the general public. See subsection 4.33.1 for further
discussion of SARA Title lU and how to access the TRI database.
Monitoring data.
A third way to determine which pollutants are emitted is to conduct
monitoring. Ambient monitoring can provide definitive indications of the presence of
a toxic pollutant in ambient air. However, proven ambient monitoring and analytical
methods have not yet been developed for all toxic pollutants. Naturally occurring and
secondary pollutants also need to be considered. Monitoring is very expensive and
may not be a necessary step in pollutant selection in the beginning stages of an air
toxics program when less expensive methods can be used. Existing monitoring
programs for criteria pollutants can also be used for air toxics identification. This
topic is discussed in more detail in Section 4.3.2.2.
Source testing/stack sampling.
Source testing/stack sampling can determine which pollutants are actually
emitted. Modeling of the measured emission rates can -be used to estimate ambient
concentrations. However, source testing is very expensive and is usually not an option
that is available to most S/L agencies.
Criteria pollutant inventories.
Criteria pollutant inventories offer another source of data. This topic is
discussed further in Section 4.3.2.2.
Step 3: Health Effects Evaluation. Another step in selecting toxic air
pollutants is to examine the known or expected health effects resulting from exposure
to the pollutant. The primary advantage of this method is that the pollutants that
have the greatest potential to cause adverse health effects are identified. However,
the major disadvantage to this method is that it does not identify pollutants actually
emitted in the area, and hence, resources could be devoted to gathering information
2-11
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on pollutants that are not truly a problem in the State or region. Therefore it is
recommended that the expected occurrence of pollutants be evaluated prior to a
health effects evaluation.
The major issue when selecting pollutants on the basis of health effects is how
to define measures of toxicity. In other words, what toxic effects will warrant listing
and how much experimental evidence of those effects is necessary? Many agencies
agree that all carcinogens should be listed. As shown in Table 2-2, lists of known
and suspected carcinogens are published by various groups.
The National Institute for Occupational Safety and Health (NIOSH) maintains
the Registry of Toxic Effects of Chemical Substances (RTECS) database. RTECS is
an online interactive version of the NIOSH publication of the same name. It
provides data for 90,000+ potentially toxic chemicals, including toxiciry data, chemical
identifiers, exposure standards, National Toxicology Program test status, and status
under various Federal regulations and programs.
Many S/L agencies have frequently used the ACGIH list of chemicals as a
basis for pollutant selection, particularly for noncarcinogens. The ACGIH list is
especially useful for identifying substances used in the workplace that are toxic and
have the potential to be emitted into the ambient air.
Finally, EPA's Integrated Risk Information System (IRIS) is an important
source of information on the health effects of over 260 chemicals. The IRIS was
described above, in Section 1.2.2.3.
Step 4: Internal Assistance From Divisions Within the Agency. Another
method of choosing pollutants to list is requesting recommendations from agency
divisions outside the air pollution group. The public health department or division
can identify toxics associated with public health problems in the State or locale. The
water pollution department or division may be able to provide information on the
most frequently discharged water pollutants. The air pollution group can then
evaluate how those substances are used in industry and whether the substances may
be emitted and become airborne pollutants. The same approach may be applied to
information obtained by the State hazardous waste management staff. Permits issued
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under the Resource Conservation and Recovery Act (RCRA) contain lists of the
constituents of hazardous waste handled by a facility. The air pollution group could
evaluate chemicals on those lists for the potential for the pollutants to be emitted to
the atmosphere, based on their use in industry. The overlap of toxics programs and
RCRA is discussed further in Section 43.2.2.
Step 5: External Assistance. Several agencies have requested assistance from
individuals or groups outside the agency during development of a list of pollutants or
after pollutant selection, as an external review. Toxicologists and physicians from
local medical and research institutions can assist in evaluating health effects of toxic
pollutants. Consultants and members of the academic community can perform
technical review of potential sources and quantities of the toxic pollutants listed as
well as review of the policy implications in listing pollutants. Personnel from outside
of the agency can give different perspectives on policy issues and supplement the
knowledge of agency staff.
Many agencies have requested industry participation in development of their
entire air toxics program, including a review of the list of pollutants to be covered.
These agencies report that the success of their air toxics programs was due in part to
industry involvement that led to increased awareness and cooperation. Participation
by public groups, citizens' committees, and environmental groups can yield the same
benefits.
22 SELECTING SOURCE CATEGORIES OF CONCERN
There are three main issues with respect to source selection that S/L agencies
encounter when designing an air toxics control program:
(1) What types of air toxic-emitting sources, if any, should be excluded from
coverage under the program?
(2) Should the program apply to existing as well as new sources?
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(3) Should sources with very low levels of toxic emissions (de minimis
levels) be exempted?
Similar to pollutant selection decisions, resolution of these issues is critical in
determining program effectiveness, and the size and nature of the regulated
community.
1. Types of Sources to be Regulated. Air toxics control programs open up
a whole new universe of sources that need to be considered and evaluated for
possible regulation. The focus will not automatically be on large volume paniculate
matter (PM) or volatile organic compounds (VOC) sources as it has been
traditionally. Sources that were previously viewed as being too small of an emitter
(e.g., auto body painters) and/or as having configurations not easily amenable to
control (e.g., small volume printers) now are being examined under toxics programs
because they emit one or more chemicals deemed to present some measure of health
risk. Area sources, whether large or small, that have been unregulated in many State
VOC programs, must now be better identified and characterized because of the
aggregate impact of their emissions. Programs based on risk levels or ambient
concentration limits may bring into consideration some very small sources because,
even though emission quantity is low, pollutant toxicity may be quite high. The high
toxicity may trigger the review of the source under the air toxics program.
For any air toxics program, there is a strong presumption in favor of regulating
all sources that emit air toxics in amounts that ma}' pose health problems to the
public. However, such a broad regulatory scope may not be practical in terms of
agency resources and priorities. Therefore, the issue usually becomes, "Which sources
or source categories can justifiably be initially excluded from coverage without
seriously jeopardizing the achievement of the program's long-term goals?"
State and local agencies have adopted a variety of approaches to resolve this
issue. There is no one correct or necessarily best approach. The resolution of the
issue will depend to a large extent on the number and mix of sources in a given State
or locale, the degree of risk posed by air toxics sources, the availability of controls,
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the resources of the agency, and numerous other agency-specific factors. Some of the
more common source exemptions are discussed below.
Mobile Sources. With the exception of California, no S/L agency currently
includes mobile sources in their air toxics program because of the dominance
(although not preemption) of Federal regulation in this area, and the resources
required for S/L agency regulation of mobile sources. This is not to say that mobile
sources are not a major contributor of air toxics exposure — they are! However, S/L
agencies have tended to focus on stationary sources for the reasons mentioned above.
The only air toxics-related mobile source regulations implemented by S/L agencies are
carbon monoxide and ozone State Implementation Plan measures. These measures
can indirectly control air toxics through the co-control of criteria and noncriteria
pollutants.
Area Sources. Area sources (e.g., dry cleaners, woodstoves, fireplaces and
other small, but numerous sources) are regulated in some jurisdictions, either under
air toxics regulations or separate regulations. Collectively, such sources can emit
significant amounts of toxic air pollutants. Because of their large number, these
sources are usually too numerous to review on an individual basis. As such, S/L
agencies should carefully evaluate their ability and need to cover such sources initially.
Nontraditional Sources. A difficult issue for many agencies is the regulation of
various "nontraditional" sources, such as wastewater treatment plants and hazardous
waste landfills. These have been shown to be significant air toxics sources in several
studies. There is a strong presumption in favor of ultimately regulating such sources;
however, an agency should carefully evaluate the number, size, and type of such
sources in their area to decide whether regulation would be practicable in the
beginning.
Sources Regulated Under the Clean Air Act. Some States have included
provisions in their regulations that exclude from State regulations pollutants regulated
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under Sections lll(d) or 112 of the Clean Air Act The Virginia regulations (Section
120-05-0301) state, "The provisions of this rule do not apply to the following:
Hazardous air pollutants regulated under Section 112 of the Federal Clean Air
Act, except to the extent such pollutants are emitted from facilities which are
not subject to emissions standards in Rule 6-1." (Rule 6-1 includes Section 112
standards enforced by Virginia).
By including such "generic" exemptions, an agency would not have to amend its
regulations when additional 112 or lll(d) standards are promulgated or when Clean
Air Act amendments are passed.
In the 1989 STAPPA/ALAPCO survey, about 17 S/L agencies said that they
exempt or plan to exempt certain source categories. Table 2-3 summarizes some of
the source category exemptions noted in the questionnaire responses. Several
agencies noted that they exempt mobile sources and/or area sources; however, the
fact that a State did not mention area and mobile sources as exempted does not
necessarily mean that the State regulates those sources. Most State responses focused
on point source exemptions. Before interpreting any of these exemptions, it is
important to read the State's own regulatory language to avoid misconstruing the
context of the exemptions.
2.3 REGULATING EXISTING SOURCES
The second major source selection issue is whether to regulate existing as well
as new sources. New and modified sources are now addressed for their air toxics
impacts in virtually all S/L air toxics programs. Starting with new and modified
sources is a natural step because of the required review and generally more favorable
control economics for these sources. Because existing sources represent the origin of
all existing toxic air pollutant emissions, the question should really be viewed as,
"When?" - not whether. Ultimately, existing as well as new and modified sources
should be regulated.
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TABLE 2-3. SOURCE CATEGORIES S/Us REPORT EXEMPTED
California
Iowa
Kentucky
Maryland
New Mexico
New York
Wisconsin
CA-Ventura
KS-Kansas City
KY-Louisville
NV-Las Vegas
Sources whose emissions are small are deferred so
resources can be spent on source categories that pose a
higher risk.
Mobile sources.
NESHAP sources, laboratory equipment, dry cleaners.
indirect heat exchangers using fossil fuel only, gas stations,
agricultural operations.
Fuel burning equipment, char-broilers, gas stations,
NESHAP or potential NESHAP sources.
Gasoline service stations; automotive repair shops; laundry,
cleaning and garment services; domestic wood stoves and
fireplaces; oil and gas production facilities; agricultural
production and services; containers, tanks, etc. without
vents; nonprocess fugitive emissions from stationary sources
such as construction sites and mine tailings.
17 specific source exemptions including certain petroleum
liquid storage and transfer facilities, certain solvent metal
cleaning processes, certain surface coating operations,
perchioroethyiene dry cleaning facilities.
Depends on pollutant. Exemptions include combustion of
certain fuels, laboratories, certain gasoline dispensing
facilities, incinerators, indoor fugitive emissions, and certain
wood combustion.
Gasoline dispensing operations using Phase I and II vapor
recovery system, small perchioroethyiene dry cleaning
facilities.
Existing sources.
Service stations, dry cleaners, fossil fuel burners.
Dry cleaners, gas stations, businesses consuming less than
1000 gallons of solvent per year.
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TABLE 2-3. SOURCE CATEGORIES S/L's REPORT EXEMPTED (Continued)
PA-Philadelphia Commercial fuel combustion sources, retail dry cleaners,
gasoline service stations, incineration other than by-product
industrial work, and a list of "incidental" sources exempted
from emission reporting, but not from "no health hazard"
requirement.
WA-Seattle 29 specific source exemptions including certain types of the
following: fuel burning equipment, internal combustion
engines, laboratory equipment, storage tanks, water cooling
towers and ponds, restaurants, cold solvent cleaners, gas
stations, and dry cleaners.
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One possibility is to establish more flexible requirements for existing sources
such as process changes, raw material substitution, and other pollution prevention
initiatives. Another approach for States with a smaller population of high risk point
sources is to address each problem source on a case-by-case basis using general air
pollution control/health protection authority.
One concern in the regulation of existing sources is how to cover sources that
typically do not have to obtain air quality permits, but that are toxics emitters. The
coverage of existing sources, either immediate or in a phased approach, presents
additional implementation problems in terms of applicability determination. If the
coverage is immediate, all sources emitting chemicals of concern will need to be
identified and evaluated according to the basis of the program (i.e., emission limits,
acceptable ambient levels, etc.). Many emitters of toxics will not be traditionally-
regulated PM and VOC sources, and inventories of such sources will likely not exist.
Whether the program has immediate or phased coverage for existing sources, the
identification of sources releasing the regulated chemicals may present problems for
the source types not traditionally regulated or permitted.
The inclusion of existing sources at some point should definitely be an element
in the design of any air toxics program. In the STAPPA/ALAPCO survey, 20 States
and 7 local agencies reported that they regulate or have definite near-term plans to
regulate emissions from existing sources. Many agencies that have a system of
operating permit renewal in place begin to regulate existing sources on this cycle of
permit renewal. In these cases, existing sources are exempt, or control is deferred,
until their operating permit comes up for renewal. For programs covering existing
sources in a phased approach under their criteria pollutant program, attention needs
to be paid to the frequency and requirements of the permit renewal system. The
review cycle should be reasonably short (i.e., no more than 5 years) and capable of
imposing substantive new control requirements in order to be effective. In addition,
Clean Air Act amendments that have been proposed include operating permit
programs capable of assessing and collecting a fee which would compensate the
reviewing agency for its time and expense.
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2.4 SELECTING SIZE AND EMISSION CUTOFFS/EXEMPTIONS
A fourth major decision point in determining the scope of an air toxics
program is the selection of size and emissions cutoffs/exemptions. Such
cutoffs/exemptions are a standard feature of most programs either as source screening
levels or regulatory exclusions. Several of these agencies have stressed that this is
one of the most critical decisions associated with launching a new program. There
are at least two ways to structure such cutoffs/exemptions.
1. Lower Size Cutoff. One approach is to apply lower size cutoffs. These
can either be source-specific (e.g., production rate) or tied to the definition of a
major source/major modification (e.g., regulations apply only to sources classified as
major under criteria pollutant programs).
2. Emissions Cutoffs/Exemptions. Another approach is to apply ^§ mim'mis
emission cutoffs or exemptions. Some agencies use stack concentrations while others
use emission rates. Some cutoffs/exemptions are pollutant specific (e.g., Maryland,
North Carolina). Others are generic (e.g., Pennsylvania exempts any source whose
stack concentration is no greater than the applicable AAL). Table 2-4 summarizes
the jig minimis emission levels reported by S/L agencies responding to the
STAPPA/ALAPCO survey. For a complete understanding of these exemptions,
readers should consult each agency's regulations.
2.5 TIMING/PHASING OF PROGRAM COVERAGE
The development of an air toxics program is clearly not a one-time effort, but
rather an ongoing task that requires multiple iterations (e.g., evaluation of how
current practices are meeting agency objectives, revision of practices to meet
objectives, and development of new objectives). Some agencies have planned their air
toxics control program to be implemented in several phases or generations. For
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instance, they may target certain high risk point sources in the first generation and
then look at "urban soup" in the second or third generation of their program.
2.6 AGENCY RESOURCE REQUIREMENTS
As mentioned previously, agency resources are a key factor to consider before
the scope of the program is defined. Some agencies have deferred control of certain
sources or pollutants due to their limited available resources. Another approach is to
require industry to provide information such as emissions data, monitoring data, and
modeling results to the agency, thus saving the agency's resources that would be
needed to perform these tasks. The Maryland Air Management Administration used
such an approach during the development of their program. Maryland felt that
significant agency resources were conserved this way.
The 1989 STAPPA/ALAPCO survey asked for dollar and work hour allocations
devoted to air toxics programs in the past year for specific work areas, such as
permitting, program development, and monitoring. The STAPPA/ALAPCO document
can be referenced for program allocations for individual S/L agencies.
For information on obtaining the compilation of the results of the 1989
STAPPA/ALAPCO survey, contact STAPPA/ALAPCO at (202) 624-7864.
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TABLE 2-4. DE MINIMIS LEVELS REPORTED BY S/L AGENCffiS
California-Bay Area AQMD
Kentucky
Maryland
Michigan-Detroit
Nebraska
Nevada
New Mexico
New York
Oklahoma
Oregon
Pennsylvania
Noncarcinogens: acceptable exposure value/4
expressed as an ambient concentration (g/nr) and as
emission rates (Ib/day). No exemptions for
carcinogens.
Pollutant-specific emission levels are given in Ibs/hr
in regulations for new and existing sources
Noncarcinogens: <5 Ibs./hour if screening level is
>200 ug/rn3' Carcinogens: same as above, but also
<350 Ibs/yr if screening level for carcinogenic effect
is > lug/nT.
Case-by-case
2.5 tons/year
0.25 lb/8 hours
Applicability thresholds are pollutant-specific and
presented in the regulation as emissions in Ibs/hr
and Ibs/yr.
Emissions potential of <3.5 Ibs/hr of VOC for
sources not given an "A" environmental rating.
Low toxicity pollutants: 6 tons/yr, not to exceed 5.6
Ibs/hr Moderate toxiciiy pollutants: 1.2 tons/yr, not
to exceed 1.1 Ib/hr High toxicity pollutants: 1,200
Ibs/yr, not to exceed 0.57 Ibs/hr.
Compound-specific
pollutants.
minimjs limits for list of
No definite cut-off established yet for many smaller
sources. Their exempted status is based more
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TABLE 2-4. DE MINIMIS LEVELS REPORTED BY S/L AGENCIES (Continued)
Pennsylvania-Pittsburgh
Rhode Island
South Carolina
Tennessee
Vermont -
Virginia
on resource limitations than on a defined de minimis
level.
Pollutant-specific, less than air toxic ambient
guideline in the stack or emission stream.
Regulations give emission levels in !bs/hr for 40
pollutants.
< 1.0 Ib/hr of PM uncontrolled
< 1,000 Ib/mo VOC uncontrolled
Ambient levels listed for pollutants specified in PSD
regulations.
Compound-specific levels given in pollutant list,
expressed in lb/8 hours.
Emission rates in Ib/hr depend on ACGIH TLVs:
1-2
3-5
6-12
13-25
26-50
51-250
251-500
501 or greater
0.
0.13
0.76
1.52
3.29
6.58
12.90
63.51
126.77
Washington-Seattle
Wisconsin
Case-by-case consideration.
Regulation gives emission rate hi Ib/hr for listed
pollutants.
Wyoming
Determined on the basis of impact and exposure.
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SECTION 3.0
EVALUATING PROGRAM IMPACTS
-------
3.0 EVALUATING PROGRAM IMPACTS
Highlights of This Section
Evaluation of program impacts, at least to some degree, may be
necessary for either legal or practical reasons.
Agencies should plan such evaluations carefully to ensure results are
credible and program approval is facilitated.
3.1 WHAT ARE THE COSTS?
Documentation of the estimated costs of proposed air toxics regulations is often
an important issue. Estimates of agency implementation costs may be needed for
administrative purposes, and estimates of the cost to affected industries may also be
needed. Effected industries and the public at large have legitimate needs for
information concerning the likely consequences of proposed State or local regulations.
For this reason, laws in many States and locales require disclosure of the estimated
impacts of a rule prior to its adoption.
In the case of air toxics programs, documentation of program impacts may be
necessary for strategic as well as legal reasons. Some S/L agencies have found it
necessary to prepare such evaluations simply to respond to industry claims that
businesses would experience unreasonable economic impacts. Regardless of the
reason, as a practical matter agencies may find it difficult to convince their governing
boards or commissions of the reasonableness of the proposed rules without such an
evaluation. Consequently, at least some cost and/or economic impact evaluation may
be a prerequisite for obtaining program approval.
Agencies should plan such evaluations carefully before starting. Estimating the
costs to industry of proposed air toxics controls, especially for existing sources, can be
expensive and time-consuming. If economic impacts are included, the task becomes
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even more challenging. Because of the many assumptions required, the validity of
cost or economic evaluations is easily challenged. Consequently, such evaluations
should be carefully designed to ensure that the results are credible and the evaluation
will facilitate the program approval process.
The following two subsections describe the economic impact analyses
undertaken by the States of Maryland and North Carolina, respectively. The
approaches taken by the two States differ considerably. Maryland chose not to
estimate emission reductions, costs, or risk reduction on a source-specific basis.
Instead, a cost-screening analysis of four types of facilities was performed and control
costs were assessed qualitatively. North Carolina chose a more quantitative approach
by performing source-specific dispersion modeling, calculating emission control costs,
and estimating exposure and risk reductions.
32 SELECTING A METHODOLOGY: MARYLAND'S APPROACH
Maryland's Air Management Administration prepared a cost analysis of their
proposed regulatory program in 1986. Maryland is now in the implementation phase
of their program. The analysis by Maryland had two primary components: the cost to
businesses to comply and the administrative cost of implementing the regulations.
The Department estimated that about 800 existing installations at about 320
existing premises would be subject to the proposed regulations, in addition to about
140 to 150 new installations per year. Existing premises would be reviewed gradually
over the first four years, and then reanalyzed on approximately a three-year cycle.
These estimates were based on a registration system that tracks new and
existing installations that discharge air emissions. To estimate the number of effected
facilities, the Department counted all installations required to obtain an operating
permit that is renewed annually, and subtracted installations for fuel burning
equipment because they are exempt from the regulations. The number of new
installations per year was based on a review of permit data from 1984-86. The
Department did not attempt to estimate the effect of small source exemptions in the
regulations, or related tasks companies are required to perform to comply with the
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Superfund Amendments Reauthorization Act (SARA). As a result, their estimates
were considered conservative.
3.2.1 Compliance Costs
For the analysis of the compliance costs to business, three categories of costs
were estimated:
o emissions estimation costs,
o air quality modeling costs, and
o emissions control costs.
The Department did not attempt to quantify certain other possible costs to business,
such as monitoring, risk assessment, and health effects data collection costs.
Emissions Estimation Costs. Emissions estimation costs were divided into two
categories: (1) costs of performing stack tests, and (2) costs of estimating air toxics
emissions using other methods.
1. Stack Tests. To estimate stack testing costs, the Department worked
through the following calculations:
(1) (Total number of installations reviewed annually)
(2) X (Percentage of installations requiring tests)
(3) = Number of installations requiring tests
(4) (-) Number of tests performed by the Department
(5) = Total industry tests
Then the Department estimated the average costs per stack test. They
estimated a cost of $70,000 to $100,000 per test for complex installations. An
estimate of $20,000 to $40,000 per test was used for less complex installations. Based
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on these estimated stack test costs and the estimated number of installations tested
each year, the Department estimated the total cost of emissions estimation for
businesses for the first four years of the program. The range in annual costs was
$75,000 to $260,000.
2. Other Methods. The Department used a similar procedure to calculate the
costs of estimating emissions using methods other than stack tests. All installations
were assumed 10 perform this type of estimation. Installations were categorized as
either complex, moderate, or simple to reflect the varying costs for estimating
emissions. Then the Department approximated costs for both high and low cost
scenarios for each category.
Using this procedure, the Department estimated that annual costs for non-stack
testing methods ranged from approximately 596,000 to $398,000 per year.
In response to industry concerns about the cost of emissions estimation using
these other methods, the Department took several steps to niinimize cost impacts.
They included:
o Allow existing installations plenty of time to estimate emissions by
phasing in the program over four years,
o Require existing premises to quantify emissions only for specifically listed
compounds,
o Provide de minimis emission cutoffs,
o Provide "back calculation" procedures for estimating emissions from
physical source data and screening levels,
o Conduct a series of workshops to familiarize businesses with
emission estimation and modeling methods, and
o Provide assistance to businesses unable to develop estimates.
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Costs. For this estimate, it was assumed that modeling would be
done for entire premises, since the ambient impact requirements of the program apply
to entire premises rather than individual installations.
Based on a screening study of approximately 50 premises, the Department
assumed that about 70 percent of the regulated premises would be able to
demonstrate compliance using the Department's conservative screening dispersion
model (TM 86-02). This would involve only minimal costs to those businesses.
To estimate the number of businesses required to perform more rigorous
modeling, the Department assumed that about 50 percent of new installations will be
constructed at existing premises. The Department further assumed that about 70
percent of new installations located at existing premises would be part of premises
that do not have operating permits. These assumptions were based on department
permit data. For purposes of making the analysis conservative, the Department
assumed that each new installation locating at a new premise and each new
installation locating at an existing premise without an operating permit would be
required to perform the more rigorous modeling.
Using these procedures and assumptions, the Department estimated that about
570 premises would incur minimal modeling costs by using TM 86-02 or other low-
cost methods. Nearly 250 premises would require additional modeling. The
Department expected to perform the modeling for about 220 of these. Thus, only
about 4 percent of the regulated premises were assumed to incur modeling costs.
For more complex premises, the Department assumed average modeling costs
of from $15,000 to 530,000. Very complex premises were estimated to incur average
costs of from $50,000 to $70,000. By multiplying the average modeling costs by the
aggregate number of premises estimated to incur such costs, aggregate modeling costs
ranging from about $195,000 to $460,000 annually were estimated.
Emission Reduction Costs. For this category of cost impacts, the Department
chose not to provide detailed source-specific and aggregate estimates of emission
control costs because of the expense of such an analysis for the Department,
confidential plant data, and because of the heterogeneous nature of the different
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facilities involved. In lieu of a source-specific analysis, the Department performed a
cost screening analysis of selected existing facilities and qualitatively assessed the
control cost implications of the proposed program.
The Department adopted a source-specific regulatory approach using a
conditional standard to create the most cost-effective regulation. This approach allows
a case-by-case appraisal of the costs and benefits of controlling each source. Also,
sources are allowed to choose the method of compliance which is least costly given
their individual characteristics. Options include choice of control technology,
substituting different raw materials, making process changes, proposing higher
acceptable levels, and, in some cases, increasing stack heights. This flexibility was
another reason why the Department found it difficult to estimate the statewide
impacts of their proposed program.
To estimate the impacts on new installations, Department staff, with the
assistance of a contractor, evaluated the cost of meeting the States proposed T-BACT
and ambient impact requirements for four types of facilities, including:
o dry cleaners discharging perchloroethylene,
o a refractory storage pile discharging chromium and aluminum oxide,
o an adhesive application facility discharging either toluene or methylene
chloride, and
o a specialty steel facility discharging chromium and nickel.
The analysis showed that new commercial and industrial dry cleaners would
require no additional control beyond current regulations. T-BACT was assumed to
include a leak detection and repair system for controlling fugitive perchloroethylene
emissions. This cost was estimated to range from $200 to $5,000 for the detector and
$50 to 53,000 for subsequent annual maintenance. Costs for the refractory storage
pile facility were estimated to $180,000 per year for a building enclosure with a fabric
filter. No additional control costs were estimated for the adhesive application facility.
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Because of New Source Performance Standards requirements, the specialty steel
manufacturer was also estimated to incur no additional costs.
3.2.2 Administrative Costs
The Department evaluated administrative costs according to five categories:
(1) Personnel
(2) Laboratory equipment
(3) Data processing system
(4) Other equipment
(5) Operating expenses
Costs were estimated to range from a first year cost of about $400,000 to about
5250,000 per year for subsequent years. Personnel costs included salaries and fringe
benefits for three engineers, a toxicologist, a lab scientist, a data device operator, and
a secretary. The Department also assumed the purchase of a gas chromatograph-mass
spectrometer, sampling trains, and a sample concentrator in the first year.
3.3 SELECTING A METHODOLOGY: NORTH CAROLINA'S APPROACH
The approach used in North Carolina's assessment included an examination of
325 of the approximately 3,000 permitted sources in North Carolina. The facilities
selected by the State for the study represented a variety of major and minor potential
sources of air toxics in all parts of North Carolina. Based on information supplied by
facility owners/operators, a list of 85 facilities with emissions of air toxics exceeding
trace amounts was compiled. These 85 facilities were then screened by the Division
of Environmental Management (DEM) using accepted dispersion modeling techniques
to determine whether ambient air concentrations exceeded the levels specified in the
States proposed regulation. Facilities whose stack emissions exceeded acceptable
levels under current operating conditions were modeled to determine whether ambient
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air concentrations resulting from their emissions would be exceed the ambient limit if
their exhaust stacks were increased to 1.5 times the building height or, failing that, to
the maximum height allowed under federal Good Engineering Practice (GEP) exhaust
stack guidelines.
Using the results of the dispersion modeling analysis, DEM estimated the costs
of complying with the proposed regulation for each facility. For those facilities
determined to be capable of complying with the regulation through use of dispersion
techniques alone, the cost of an adequately-sized exhaust stack was calculated. For
facilities determined to require add-on control technology, such as fabric filters or
carbon absorbers, the costs of applicable add-on control systems were calculated.
Cost estimates did not take into account any existing emission controls at the
facilities.
Using these cost results, the potential economic effect on each facility was
examined in terms of estimated product price increases and/or profitability decreases.
If a facility's products could potentially experience a price increase of more than
5 percent, assuming no absorption of cost increases, the facility was predicted to
experience a significant economic impact. Similarly, if a facility's profit margin could
potentially drop to zero as a result of compliance with the regulation, the facility was
predicted to experience a significant economic impact.
The benefits of the proposed regulation were assessed by analyzing selected
facilities representing the potential range of benefit impacts and related costs resulting
from the regulation. Benefits were measured in terms of the reduced human
exposure to ambient concentrations of toxic chemicals in the vicinity of the example
facilities. For carcinogens, benefits were expressed in terms of the reduced annual
incidence of cancer for exposed populations resulting from the regulation. For
noncarcinogens, benefits were expressed in terms of the number of individuals whose
exposure to air toxics would be reduced to concentrations below proposed ambient
thresholds. The benefit estimates were then coupled with the estimated costs of
compliance for each example facility to obtain an overall indication of benefits
relative to costs.
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The primary findings and conclusions of the study were as follows:
o A majority of existing sources included in the survey used to develop the
findings in this report (216 of 325) would not likely be affected by die
proposed regulation because they do not emit any of the 116 listed toxic
air pollutants in more than trace amounts. Eighty-five of the 325
sources surveyed emit more than trace amounts of one or more listed
pollutant
o Fifteen of the 85 facilities emitting more than trace amounts of air toxics
would comply with proposed acceptable ambient levels under existing
operating conditions.
o Seventy of the 85 facilities emitting air toxics in more than trace
amounts showed ground level concentrations exceeding acceptable
ambient levels for one or more of the 116 listed pollutants under current
conditions. This finding is based on conservative dispersion modeling
assumptions (i.e., the dispersion modeling analysis may predict higher
concentrations than actually exist). In some cases, facilities did not
report stack parameter data and conservative assumptions were used to
assign model inputs for these emission points. More detailed dispersion
modeling on a small number of facilities for the benefits analysis showed
that many of these same facilities would be able to comply with the
proposed regulation without further control.
o Forty-two of the 70 sources modeled hi the stack height analysis could
comply by raising their stack height, thereby reducing ambient impacts to
acceptable levels. However, most of these would need to raise their
stack to the maximum height allowed by GEP to comply.
o None of the 42 facilities required to increase their stack height to
comply with the proposed regulation would likely experience significant
economic impacts.
o Twenty-eight of the 70 facilities modeled would need to upgrade existing
or install new add-on control systems in order to reduce ambient impacts
to acceptable levels. Ten of these could potentially experience
significant economic impacts as a result.
o The analysis of benefits of the proposed regulation showed that cancer
cases among persons living in the vicinity of the 4 example facilities
analyzed for carcinogenic pollutant emissions would be
reduced from 1 case every 20 years to 1 case about every 60 years for
two example facilities. Reductions in annual cancer cases for another
example facility would be from 1 case every 25 years to 1 case about
every 40 years.
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o The cost/benefit ratio for control of sources of carcinogens ranged from
a low of $90,000 per cancer case reduced to a high of $300 million per
cancer case reduced. The cost/benefit ratio for the other 2 example
facilities analyzed were $2 million and $33 million per cancer case
reduced, respectively.
o In the case of noncartinogens, the number of exposed individuals would
be reduced by 10 near 1 of the 4 example facilities analyzed and by
1,960 near another example facility. The number of exposed individuals
would be reduced by 229 and 1,760 near the other 2 example facilities,
respectively.
o The cost/benefit ratio of control for sources of noncarcinogens ranged
from a low of S9 per exposed individual to a high of $160 per exposed
individual.
North Carolina's experience with attempting to estimate program cost and
economic impacts was similar to Maryland's. The North Carolina DEM completed
their analysis after more than two years work by agency and contractor personnel.
The report, published in April 1987, subsequently underwent intense scrutiny by
several industry groups and individual companies. Industry representatives criticized
the report on several grounds, most especially because the cost estimates did not
include any direct cost input from individual plants.
Subsequently, the North Carolina Department of Commerce commissioned a
professor in the business school of a local university to critique the DEM report. The
critique contended that the analysis was unreliable because of several factors not
considered in conducting the analysis. The critique concluded by stating that a
reliable study would be very time-consuming and expensive to carry out.
North Carolina's effort to analyze the cost and economic impacts of their
proposed air toxics regulation raised the same basic issue as Maryland's effort: how
to accurately estimate a program's impacts within available resources. North
Carolina's study, which included dispersion modeling, control cost estimation, economic
impact analysis, and cost/benefit analysis for several dozen sources, cost approximately
$65,000. At a minimum, a truly comprehensive assessment of cost and economic
impacts would require several hundred thousand dollars and the collection of detailed
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plant-specific data from numerous sources. As of the drafting of this manual, a bill
was pending in the North Carolina General Assembly to more clearly define what
constitutes an "adequate" cost and economic impact evaluation for a proposed state
regulation.
3.4 PLANNING A COST OR ECONOMIC IMPACT EVALUATION
Where preparation of a cost or economic impact evaluation is necessary either
for legal or practical reasons, plans for the analysis should be carefully considered
before commencing work. A list of considerations to aid the planning of such an
analysis aooears in Table 3-1.
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TABLE 3-1. CONSIDERATIONS IN THE PLANNING OF
REGULATORY IMPACT EVALUATIONS
Carefully consider the goals and uses of the analysis.
Consider the types of impacts that are most relevant to program approval and
focus the analysis on those impacts.
Evaluate the acceptability or credibility of the results if the scope of the
analysis must necessarily be limited.
Use accepted and defensible methodologies, especially if major simplying
assumptions are necessary.
Involve industry and other outside advisors in the design of the analysis.
Use actual plant data to the fullest extent possible.
Avoid reporting aggregate statewide costs unless confident of the accuracy of
the estimate.
Carefully consider the representativeness of the sources analyzed.
Report the results in a manner easily understood by the public.
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SECTION 4.0
AVOIDING PITFALLS
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4.0 AVOIDING PITFALLS
Highlights of This Section
o Challenges to a proposed program should be anticipated and sound
responses developed.
o An effective communications strategy can be essential to the success of
a program.
o Duplication of effort can be avoided and resources conserved by
coordinating with other toxics-related regulatory programs.
o Administrative progress and control effectiveness should be measured
botn qualitatively and quantitatively :o ensure program goals are
achieved.
4.1 DEFENDING THE PROGRAM ALONG THE WAY
This subsection summarizes some of the most common charges leveled against
proposed S/L air toxics programs by those opposed to their approval. Air toxics
programs have been controversial in some States and their approval may require a
strong defense of the program's need and features. Opposition by parties affected by
the regulations should be anticipated. Understanding the likely adverse comments and
developing sound responses to those comments early in the process may be one of the
most important tasks in the development of a program.
A valuable piece of advice from an experienced former air toxics program
official is to build a network of S/L agency staff contacts to counsel you, especially
during the program design and approval stage. Conferring with others who have
already encountered similar opposition can be extremely helpful in answering
questions, testing out responses, and building confidence. The Data Base Report on
State. Local, and EPA Air Toxics Activities (EPA-450/3-89-29) published annually by
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the National Air Toxics Information Clearinghouse (NATICH), includes an extensive
list of S/L contacts in various program areas.
Table 4-1 highlights some of the most likely comments and offers some
suggested responses, based on the experience of S/L agencies who have successfully
defended their programs.
42 ENSURING EFFECTIVE COMMUNICATION
This subsection discusses ways to communicate effectively with interested parties
during program development and implementation.
4.2.1 Communicating Sariy and Often
At EPA workshops on air toxics program development held across the country,
one of the topics for group discussion was the nature of communication needs in air
toxics program development and implementation. The consensus of those discussions
was "Communicate early and often! The success of your program will depend on it!"
Understanding the Nature of Environmental Communication
Communicating successfully requires an appreciation of the unique nature of
environmental communication. Communication on environmental issues is distinctive
in four ways. The first is distinctive feature is the complexity of information.
Environmental communication frequently involves complicated subject matter such as
science, economics, law, business management and human behavior, with their trade-
offs and interactions. The second way is the gap in technical knowledge of the
general public. Technical information is presented about problems and solutions, but
the public may well not understand all of the terms, technical processes, etc. The
third distinctive feature of environmental communication is the personal impact of the
issues at stake. The air people breathe is, of course, a deeply personal concern. The
fourth way is the
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TABLE 4-1. LIKELY ADVERSE COMMENTS AND SUGGESTED RESPONSES
Comment
Potential Response (Aa Applicable)
There is little or no scientific
documentation that an air toxics
problem exists.
o Several EPA studies have, shown that significant risks are
associated with emissions of air toxics.
o SARA Title HI data show that large quantities of toxics are
released into the atmosphere - 2.7 billion pounds annually
from manufacturing plants alone.
o Air toxics programs are designed to prevent puoiic health
problems from arising.
o Citizen complaints and reported illnesses near industrial
plants often can be traced to toxic air emissions.
Pollutant selection is arbitrary,
as evidenced by the wide range in
the number of pollutants regulated
by States.
o Evidence is available to support regulation of specific
compounds, including categorical findingsr case-by-case
determinations, extensive screening of specific compounds,
emission inventories, and recommendations by other
organizations (e.g^ ACGffl, HIOSH< CAG, OSHA).
o The list includes only those of local concern.
o Federally regulated pollutants are exempt - thus there is no
duplication.
o The list is subject to revision and is a "living list."
o Industries can demonstrate that emission of a particular
pollutant from their plant does not pose a problem.
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TABLE 4-1. LIKELY ADVERSE COMMENTS AND SUGGESTED RESPONSES
(continued)
Comment
Potential Response (As Applicable)
3. Air toxics are already regulated
under other programs.
o SARA Title HI data show air toxics are not well controlled
generally.
o Criteria pollutant programs don't focus on toxics.
|) Many significant existing sources of .iir toxics are oooriy
controlled.
o Some air toxics sources are not covered by criteria pollutant
programs (e.g., POTWs, dry cleaners).
4. Program costs are unreasonable
o Demonstrated controls at a reasonable cost are available
for most sources.
o Sources can select among several control alternatives.
o Case-by-case procedures are available to consider any
unreasonable impacts.
o Most existing sources would not be affected; most new
sources require stringent controls anyway.
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TABLE 4-1. LIKELY ADVERSE COMMENTS AND SUGGESTED RESPONSES
(continued)
Comment
Potential Response (As Applicable)
Legal authority is inadequate
o General enabling authority has proven sufficient in most
states.
o The State Attorney General has concluded that adequate
authority exists.
o Federal law may soon reauire regulation of air toxics sources
in any case.
6. Local industry will be disadvantaged
and experience unacceptable delays
by complicated reviews.
o Air toxics control is not the most important factor in
competiveness on an international level (e.g., value of S).
o All local industries would be subject to the same degree of
control
o New source reviews requirements tends to equalize interstate
effects for all new sources.
o EPA resources are available to support implementation.
o Some additional costs due in part to criteria pollutant
programs.
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involvement of relative risks. The distinction between voluntary and involuntary risks
is frequently a factor in environmental communication.
4.2.3 Communicating Program Objectives
In the course of planning, developing and implementing an air toxics program,
S/L's will need to communicate and coordinate with industry, the public, and a variety
of public interest groups. The information needs of these groups differ, both in
content and timing. Industry participation in the program development process is
particularly crucial because the regulatory agency will not only need help in emissions
data collection, monitoring and/or modeling efforts, but will need industry's
cooperation to minimize opposition to the program. Typical industry communication
objectives during the problem definition stage of the program development process are
to:
o inform owners/operators of potentially affected sources of the reasons
for data collection,
o explain how data will be used, and
o explain how to generate the information requested (e.g., how to estimate
emissions).
In some cases, industries are skeptical of data requests by S/L agencies.
Reasons for resistance to supply information have included the attempt to gather too
much information initially (e.g., requesting information about emissions for a very long
list of pollutants), and the failure to adequately explain the reasons for data
collection.
As the program is designed and implemented, various industry groups may have
different information needs. It will then be necessary to:
o document the impacts of the program,
o explain the rationale for pollutants and sources covered and for the
standards selected,
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o explain compliance requirements, including inspection, stack testing,
monitoring, and reporting requirements, etc., and
o negotiate in cases of potential violation.
The information needs of the public or public interest groups may be somewhat
different from those of industry. Communication with these groups typically involves
describing the proposed program, explaining general progress in controlling air toxics,
explaining actions and seeking public opinion regarding a specific case.
Communication with the public about a particular source is likely to be one of the
most common communication needs after an agency's air toxics program is in place.
.Another important consideration is presenting the impacts of the proposed
regulation. These imDacis may include economic impacts to industry as well as health
impacts to the general public. Such information should be presented as soon as
possible, with emphasis on any reservations about reliability. Impacts should be
neither exaggerated nor minimized, and worst-case estimates should be identified as
such. Maryland has found that presenting impacts information to the public about
health issues is their most effective communication approach. In most cases Maryland
has been able to state that predicted ambient concentrations are below levels
considered protective. Keeping information simple and straightforward is beneficial.
It is also useful to anticipate questions the public will ask and to prepare general
responses. Maryland stresses that it is very important for the communicators to
understand that people are truly concerned about their own health and that of their
children.
In summary, throughout the air toxics program development process, the agency
will need to work closely with all interested groups in order to:
o explain problem definition measures underway and the reason air toxics
control is being investigated,
o solicit program design assistance, and most importantly,
o achieve support from and consensus among various interests that will
help in achieving compliance with proposed control measures.
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4.2.4 Meeting Your Communication Objectives
S/L agencies have used a variety of communication techniques to convey the
objectives of their program. These include such commonly used techniques as
committees, public hearings, public and industry seminars, and newsletters.
Committees. One of the most successful and widely used techniques is forming
a committee or task force. According to several agencies who have sought committee
advice and comment, there are two keys to successful involvement of outside groups.
First, the representatives chosen to speak for a group must have the authority to
speak on the group's behalf. Second, each representative must take information back
to their respective group ;o keep that group well informed. Also heipfui, if possible
is to have the committee or task force complete its work during the same
administration to minimize the turnover in committee or task force membership.
Having to educate new members is time-consuming and can undermine momentum.
In selecting committee members, it may be helpful to have the Governor, or other
leading official, request directly that certain groups or individuals participate on the
committee. This may ensure fair representation of all groups.
Michigan's air board appointed a Special Advisory Committee to determine if a
problem existed with toxic emissions, and if so, how such emissions should be
controlled. Several disciplines and interests, including industry, were represented on
the committee and were involved throughout program development. All meetings
were open to the public and invitations were sent to many groups and individuals to
attend each meeting. The Air Quality Division staff attributed a large measure of the
program's success to such public participation.
Philadelphia's Health Commissioner appointed an ad hoc advisory committee to
advise the air agency in setting ambient guidelines. Industry, academia, government,
and the community were all represented on this ten-member committee of experts in
the fields of toxicology, industrial hygiene, and occupational medicine. At the
beginning of the guideline development process, each member assumed responsibility
for researching and evaluating available information on several of the 99 substances
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proposed for regulation. Final guidelines were set by a consensus of the group.
Philadelphia's Air Management Services (AMS) noted that it was sometimes difficult
for the committee to reach agreement on a particular guideline or procedure, but
added that use of the ad hoc advisory committee composed of different interest
groups was important. The AMS said it was important that all members of the
committee were willing to work toward acceptable solutions. Connecticut has also
had experience in forming a working group to assist in program planning and
development. The Connecticut groups are described in the case example highlighted
on the following pages.
At EPA's air toxics workshops, staff members from Connecticut's Department
of Environmental Protection (BE?) Air Compliance Section described the various
groups involved In that agency's decision-making process in program planning and
.development. In addition to the Department staff, nine other groups are involved:
o the State Implementation Plan Revision Advisory Committee (SIPRAC),
a permanent steering committee [not formed specifically for the
hazardous air pollutant (HAP) program] of approximately 50 members
representing a broad range of interests;
o the HAP Study Subcommittee, a seven-member SIPRAC subcommittee
formed for discussions of detailed issues, consisting of two attorneys (one
representing business and industry and one representing an
environmental advocacy group), an industrial hygienist, a State
lexicologist, an industry engineer whose company does not have
manufacturing facilities in Connecticut, and two DEP engineers [The
HAP subcommittee discussed and resolved several issues and presented a
final version of die program description to die mil SIPRAC];
o specific interest groups, such as the Connecticut Business and Industry
Association, who gave "reasonable and prudent" recommendations on
several issues such as the setting of acceptable ambient levels;
o environmental activists including the Environmental Caucus, an umbrella
organization comprising members of several groups [These groups were
instrumental in the reversal of the policy to allow dispersion as a means
of compliance];
o the State's Department of Health Services (DHS), who had had
experience in working with an advisory board and developing health
standards for drinking water [Through a memorandum of understanding,
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the two departments agreed upon a procedure through which DHS
would provide expertise to DEP];
o U.S. EPA Regional office staff, who reviewed the program descriptions;
o the State Attorney General's office, who gave legal advice;
o the general public, who commented in public hearings after the
regulations were drafted and reviewed by SIPRAC; and
o the State General Assembly, who mandated a study of the feasibility of
an air toxics program and passed the regulations for the HAP program.
Public Meetings and Public Hearings. Some States, such as Maryland, are
required by law to give citizens an opportunity to request a public hearing when
certain sources have applied for a construction permit. In Maryland, of the permit
applications for which public hearings may be requested, about half result in a
hearing. Maryland's Air Management Administration recognized a need to discuss the
permit applications and air pollution issues with the public in a more casual
atmosphere than offered by a public hearing. Thus, a less formal public meeting is
usually held followed by a formal public hearing.
In explaining their experiences for the report National Air Toxics Information
Clearinghouse: Case Studies in Risk Communication (EPA-450/5-88-003), Maryland
noted that in a few instances, a brief discussion of the source and permit application
was sufficient to allay public concerns, and that little opposition had been expressed at
the public hearing even though, in most cases, both the public meetings and the
public hearings have been well attended. The public meetings helped focus attention
on air pollution control issues. It was Maryland's experience that some people wanted
to discuss issues related to the facility over which the air management staff has no
jurisdiction (e.g., traffic problems).
In preparing for public meetings and hearings, Maryland judges the level of
detail needed for each meeting, based on their familiarity with interested citizens'
groups, and business and industry representatives likely to be present. If necessary,
the Department's Assistant Secretary for Toxics, Environmental Science and Health
can be called on to describe risks.
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In Maryland, the opportunity to request a public hearing is announced in
newspapers. Citizens' groups in the affected area are contacted, but the responsibility
for becoming aware of potential hearings lies with the interested parties. Maryland
feels that the public is pleased that toxic emissions have been evaluated and that
efforts have been made to solve any problems. Simple, straightforward verbal and
written presentations are the most effective, with more detailed material available on
request. They have distributed fact sheets as people enter the public meetings and
hearings. The fact sheets describe, in laymen's terms, the facility or plant, the
products it manufactures, the processes it uses, pollutants that will be emitted,
modeling results showing the concentrations predicted for each of the pollutants, and
an acceptable ambient level for each pollutant.
Special Industry Meetings or Seminars. Some agencies have targeted certain
industries common in their area for special meetings or seminars aimed at the toxics
issues of the particular industry. For instance, North Carolina and Virginia have both
worked with the furniture manufacturing industry. Through EPA's Control Technology
Center, Virginia investigated and met with furniture manufacturers on the control of
formaldehyde emissions. This same type of meeting with a special interest group has
also been used with citizen and environmental groups, as well as with groups of
people who are interested hi emissions from a particular source.
Similarly, Maryland held discussions on proposed regulations with
representatives of the Baltimore Chamber of Commerce, the Chemical Industry
Council, and individual businesses. These meetings were held to ensure that effected
industries understood how the proposed regulations would apply to their facilities and
to give them an opportunity to explain any specific problems they foresaw in
implementing the regulations.
Newsletters. Some agencies publish newsletters to inform all concerned groups
on issues the agencies are addressing. Newsletters are prepared for a wide audience
with varied interests and concerns rather targeted at only one interest group.
Wisconsin's Department of Natural Resources, Bureau of Air Management, publishes
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a free quarterly newsletter called "Air Matters." Similarly, the Northeast States for
Coordinated Air Use Management (NESCAUM) also publishes a quarterly newsletter
called "Northeast ATReport" The purposes of this newsletter are to improve the
exchange of information among the eight NESCAUM States and to share the
northeast region's concerns, proposals, and programs with air quality officials and
other interested parties throughout the country.
42.5 Communicating About Risks
As S/L agencies design and implement air toxics control requirements, risk
communication, or explanation of the health risks posed by toxic emissions, will be
required. In 1987, EPA's Office of Policy, Planning, and Evaluation estabiisnea che
Risk Communication Program (RCP). The goal of the RC? is to provide technical
assistance in communicating environmental risks to the public. In addition to assisting
EPA staff with their risk communication efforts, the RCP sponsors its own projects 10
advance the state-of-the-art of environmental risk communication. Projects sponsored
by the RCP are selected after receiving input from the Risk Communication Work
Group, comprised of representatives appointed by each EPA Office.
Currently, the RCP is concentrating on risk communication training, radon, and
Title III of the Supernind Amendments Reauthorization Act (SARA Title HI). Risk
communication training has been selected as a priority by the RCP in order to
expedite the transfer of risk communication skills to EPA and S/L agency staff.
SARA Title HI is an area of emphasis for the RCP because of its potential
importance at the community level. Radon risk communication is an area of
concentration by the RCP because of the large need for it perceived by the Office of
Radiation Programs. Several projects form an integrated examination of how to
develop an effective radon risk communication program.
Also, an information hotline is operated by the staff of EPA's RCP. The
hotline gives program offices, regions, and S/L agencies quick access to research
results, provides the names of experts, and provides review of proposals and draft
materials.
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For comments or questions about the RCP, contact Deny Allen at (202) 382-2747,
or Ann Fisher at (202) 382-5500. The RCP hotline number is (202) 382-5606.
Two pressing reasons exist for improving an agency's ability to communicate
with the public about risks. The Srst is that the most serious remaining
environmental problems are not the most obvious ones. Because the public ultimately
determines the regulatory agenda, it is important to put the risks in context for them.
Second, many current environmental hazards are beyond the traditional tools of
regulation and require individuals to take action themselves (e.g., radon levels in
houses).
The EPA shares these concerns and has identified four steps of risk
communication through its RCP. These steps, applicable to ail communication
objectives mentioned hi this section are:
Step 1. Determine the purpose and audience of the
communication (this will guide the factual content of
the message).
Step 2. Develop strategies for getting the message across
(this includes determining which groups and media
would provide the best mechanism for reaching the
audience and establishing the credibility of the
information source).
Step 3. Implement the strategies,
Step 4. Evaluate the effectiveness of the risk communication
effort.
The EPA's Office of Policy Analysis has published a brochure titled, "Seven
Cardinal Rules of Risk Communication". While aimed at making and explaining
decisions that involve risk to the public, these guidelines give sound advice to agencies
developing and implementing an air toxics program.
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To obtain the brochure "Seven Cardinal Rules of Risk Communication", contact the
Risk Communication Program at (202)382-5606.
Case Studies in Risk Communication (EPA-450/5-88-003) published by
NATICH, is a further source of risk communication aid. This document profiles
three case studies, and includes the agencies' assessments of what was done well, what
could have been done better, and what advice they would offer to other agencies
undertaking a risk communication program. The three agencies emphasized that it
was very important to be open and straightforward with ail interested parties, :o be
willing to answer questions and investigate all issues.
Summary advice for other agencies includes putting risk estimates into
perspective for the public, thoroughly evaluating the facility in question, anticipating
the public's questions in order to present technical information clearly, and being sure
of the facts and confident of explanations of agency policy before going to the public.
42.6 Working With the Press
When addressing air toxics issues (whether the initial adoption of a program or
a particular permit application) agencies will undoubtedly have contact with the press.
How the press portrays the issue may greatly affect the public perception or reaction.
Agencies may have news conferences to formally pass information to local newspapers,
and to television and radio stations. In addition to large news conferences, individual
or small group briefings with reporters may be useful. Such small group sessions are
more relaxed, allowing the agency to elaborate on complex technical concepts.
Of major interest to the press recently are reports generated by SARA Title III
of toxic chemical releases. These reports of millions of pounds of toxic air
contaminates released annually have generated considerable public support for air
toxics controls. S/L agencies should be familiar with SARA Title III and be prepared
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to respond to press and public inquiries about efforts to control these releases.
Agencies can expect continued press attention on Title HI data and its implications
for public health.
From SARA Title in coverage and other experiences, agencies have learned
some important lessons. La dealing with a source of inorganic arsenic emissions in
Tacoma, Washington, EPA and the Puget Sound Air Pollution Control Agency
(APCA) had almost daily contact with the press. Both agencies felt they were able to
build a good relationship with reporters. As described in Case Studies in Risk
Communication, the Puget Sound APCA felt the agency had learned some important
techniques for dealing with the press. They found that the main concern among the
newspapers concerning the story was to be the first to publish a particular item.
regardless of accuracy. For this reason, Puget Sound APCA learned the importance
of communicating facts to the press understandably and accurately. The agency found
that the press was interested in covering events rather than explaining the process to
be used in decision-making, or explaining a control alternative. When the agency staff
and reporters came to understand each others' concerns, they were able to help each
other and work well together.
4.3 COORDINATING WITH OTHER REGULATORY PROGRAMS
This subsection describes how State Implementation Plans (SIPs) and other
toxics-related programs can complement an air toxics control program. Existing
regulatory programs can provide a wealth of data useful to air toxics control
programs. For example, if the air agency is trying to quantify evaporative toxic
emissions (e.g., waste solvents) from settling tanks, the agency's waste management
staff may be able to provide data on tonnages of waste present, composition, tank
sizes, and tank operating characteristics that would facilitate the emissions calculations.
The waste management staff may routinely require reports that provide data needed
for air toxics emissions evaluations and control. Planning air toxics programs in
conjunction with other programs conserves S/L resources and avoids the pitfall of
duplicating work already done.
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43.1 Recognizing the Commonality of Different Regulatory Programs
Seemingly different regulatory programs share a common environmental goal.
Each is charged with protecting public health. State criteria air pollutant programs,
for example, limit criteria emissions to levels that will not exceed health-based
national ambient air quality standards (NAAQS). Air toxics programs aim to lower
toxic emissions to levels whereby public health risks are minimized or kept below
levels deemed to be unacceptable.
Coordination with existing criteria air pollutant control programs is a
prerequisite for any successful air toxics program. In addition, other existing
environmental and health protection programs also provide benefits to an air toxics
program even though they may not be specifically aimed at controlling air emissions.
Some of the more prominent programs include:
o Superfund Amendments and Reauthorization Act (SARA)
o Resource Conservation and Recovery Act (RCRA),
o Occupational Safety and Health Administration (OSHA), and the
o Clean Water Act (CWA).
Programs such as these cover a diverse set of topics and provide multimedia
toxics control opportunities. Focused primarily on hazardous waste treatment, storage,
and disposal, RCRA has components that are applicable to air toxics. Activities
under SARA Title HI cover all media and have direct implications for air toxics
control. Although OSHA does not address air toxics releases to ambient air, it does
identify industrial and commercial activities that produce airborne toxics of concern.
The CWA program can serve as a good source of information to evaluate potential
air toxics emission sources from the standpoint of identifying chemicals in a process
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and its wastewaters. More detailed information on the coordination possibilities
between these programs and a developing air toxics control program is given in
Subsection 433.
Air toxics programs can benefit from coordination with these toxic-related
programs. As discussed in Section 2.0, a S/L agency's initial goal is usually to
determine the sources emitting pollutants deemed to pose toxic concerns. Each of the
four companion programs listed above can provide useful information on sources
known to be handling/producing chemicals that may be viewed by the air agency as a
toxic of concern. Some programs may have developed emissions information that
could be used to help bound the problem. The air agency can investigate the
potential for air emissions. In addition, the air toxics program may benefit from
requirements imposed by these companion programs (e.g., a source is prohibited from
putting waste solvents in an open-air lagoon). As the S/L program evolves, reporting
requirements of other programs may have enforcement and source monitoring benefits
for the air toxics control effort.
As a result of these commonalities, S/L agencies should take advantage of
every opportunity to use information developed by other programs and to optimize air
toxics control via co-control efforts. Recognizing and taking advantage of these
opportunities will save agency time, money, and waste from duplicated efforts.
432 Coordinating with State Implementation Plans (SIPs)
SIP Activities and Their Relationship to Air Toxics
Although the primary goals of SIPs are attaining and maintaining the National
Ambient Air Quality Standards (NAAQS) for criteria air pollutants, an important
secondary goal can be enhancing the control of toxic air pollutants. Reductions in
criteria pollutants through SIP activities, in addition to Federal regulatory efforts
focused on criteria pollutant control, have been shown to produce substantial
reductions in specific air toxics that exist predominantly as a form of either PM or
VOCs.
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The air toxics problem overlaps with PM and VOC problems in two ways.
First, many areas that are nonattainment for participate matter nominally
10 micrometers or less (PM^) and virtually all ozone nonattainment areas to be
addressed in upcoming SIP revisions involve large urban areas that are believed to
have air toxics problems. Second, the vast majority of toxic substances belong to the
general categories of ?M and VOCs.
Major SIP changes are under development in response to a revision in the PM
NAAQS and the passing of the attainment date for the ozone NAAQS. Additional
controls designed to reduce criteria pollutants can be justified, in part, by their
simultaneous payoff in air toxics coniroi. Moreover, these SIP control efforts,
properly designed, can do mucn more to reduce ihe air toxics concerns associated
with increased cancer incidence and risks to the maximum exposed individual.
In 1987, as part of the Clean Air Act's requirement that EPA periodically
review and, if appropriate, revise the NAAQS, EPA revised the primary and
secondary NAAQS for total suspended paniculates (TSP) to apply to PMj0. In the
case of PMjg, agencies were to submit a plan by August 1988. All areas within a
State are classified as Group 1, II, or HI, based on the probability of attainment of
the new PMj0 standards.
In May 1988, EPA issued "SIP calls" for 66 areas that failed to meet the
December 31, 1987, Act deadline for attainment of the ozone NAAQS. Revised
ozone SIPs will be developed in two phases. The first phase will focus on upgrading
emission inventories and correcting loopholes and deficiencies in existing SIP's. The
second phase, and its timing, will be contingent on EPA's final post-1987 Policy (or
Clean Air Act amendments). Regardless of the ultimate schedule for revising existing
ozone SIP's, it is clear that many State and local agencies will need to consider
additional VOC control measures in the coming months.
Both the ozone and PM.0 SIP actions offer several opportunities for enhancing
State and local air toxics programs. First, S/L agencies are encouraged to develop an
air toxics component for their ozone and PMj0 SIPs. In this way, air toxics and SIP
goals can be explicitly addressed simultaneously hi the context of SIP themselves.
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One benefit of this integrated approach could be the enhanced acceptability of SIP
control measures that can be credited with both criteria pollutant and air toxics
reductions. In addition, SIP control measures that may be somewhat marginal from a
purely VOC perspective may be regarded more highly if they are demonstrated as
having significant health risk reduction benefits.
In short, significant cost saving opportunities appear possible for S/L agencies
by promoting better coordination vith air toxics programs in the development of SIPs.
Many of the same point and area sources are likely to be arfected by both programs.
Coordination Opportunities
Updating and upgrading emissions inventories for ?Mj0 and/or ozone SIP
purposes is a good opportunity for S/L's to enhance the utility of these inventories for
air toxics applications. Several suggestions follow on how to optimize inventory and
air monitoring efforts, so that the data can be used for multiple purposes. If
implemented, these ideas are likely to reduce total resource requirements compared to
carrying out separate programs to accomplish toxic and criteria pollutant goals.
1. Source Category Coverage.
It is usually beneficial to inventory the sources and/or use the results of
monitoring programs to identify specific air toxics of concern. The S/L agency is
already aware of major point sources included in criteria pollutant inventories. When
updating these inventories for SIP purposes, the agency can also review these sources
to determine if they could be sources of air toxics of concern. The EPA's Air
Emissions Species Manual (EPA-450/2-88-003a and b) and the Toxic Air Pollutant
Source Crosswalk (EPA-450/4-87-023a) are good references to use to identify
potentially toxic constituents of paniculate matter (PM) or volatile organic compounds
(VOC) emissions, and the sources that emit them. The Crosswalk associates emitting
source categories with specific pollutants and as such is an indication of the potential
for a given substance to be emitted by a particular source category. The Ajr
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Emissions Species Manual is a two-volume document that contains speciation factors
for PM and VOC that can be used to estimate the specific compounds that comprise
PM and VOC emissions.
Many of the toxics-emitting sources have typically been included in past
emissions inventories for PMj0 or VOC (ozone). Some newly-implicated source
categories such as treatment, storage, and disposal facilities (TSDFs), leaking
underground storage tanks, and publicly-owned treatment works (POTW) are
important sources of toxic emissions, but have not typically been included in past
criteria pollutant emission inventories. Including these sources in updates to the
inventory should be required because opportunities for coordination certainly exist
with water, hazardous waste, and solid waste program offices.
2. Pollutant Coverage.
Air toxics may be in the form of PM, volatiles, or semivolatiles. Metals and
certain polycyclic organics [e.g., benzo-a-pyrene (B(a)P)] will likely exist in the
ambient air in particulate form, almost always concentrated in the smaller size ranges
(< 10 micrometers). The VOCs of concern for ozone formation also are usually
composed of multiple chemicals, many of which may be considered toxic.
Ideally, the VOC and PM^ inventory should be completely speciated for each
toxic of concern. Where this is not reasonable, a smaller list of compounds of
interest can be developed by first scrutinizing the applicable point sources. Using
data on hand such as permit files, tests/analyses, the Air Emissions Species Manual.
and "right-to-know" information from sources as a result of SARA Title HI
requirements, point sources can be evaluated with respect to their emissions of air
toxics of potential concern.
Area sources, such as motor vehicles and wood combustion, have been shown
to be a major concern in many areas. This concern can usually be traced to a
number of pollutants which include formaldehyde, benzene, 1,3-butadiene, chromium,
B(a)P, and others.
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3. Monitorin Considerations in SIPs for Ozone and
Ambient monitoring is usually an important aspect of preparation and execution
of a SIP. The ambient monitoring program for PMy, and ozone will result in a
collection of particulate samples and some measurement of the nonmethane organic
compounds. While these results are of little use directly in the assessment of air
toxics "potential," some supplementary analyses can be useful. The paniculate samples
can be inexpensively analyzed for total metals (e.g., arsenic, beryllium, cadmium,
chromium), and it can be a reasonably minor effort to supplement VOC programs by
speciating total VOC samples using EPA-supported programs. The EPA supports a
sampling program by which S/L's agencies can obtain ambient nonmethane organic
compound/nitrogen oxides (NMOC/NOX) ratio data for 6 to 9 a.m. summer weekday
situations. Through this program, S/L agencies provide contract funding, sampling
sites, and personnel. The EPA provides sampling equipment, transportation, and
contractual analytical capabilities. A number of the VOC samples collected under the
program in past years have been analyzed for organic species. This support
mechanism continues to be available to S/L agencies that want to obtain both VOC
and air toxics data for a preliminary look at what air toxics might exist in the ambient
air.
Arrangements can also be made for analysis of particulate filters for metals and
B(a)P and for sampling and analysis of cartridges for aldehydes, ketones, and other
oxygenates. The EPA will facilitate S/L efforts to evaluate these samples. A broader
but similar program also exists to provide for sample and analyze of 24-hour samples
taken every 12th day throughout the year, if desired. However, this program is almost
exclusively in the interest of air toxics screening and does not contribute greatly to
PMj0 or ozone SIP development. The S/L agencies should keep this information in
mind when defining the nature and extent to which their ambient monitoring program
for criteria pollutants is augmented and/or sensitized to air toxics concerns.
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For more information on urban air toxics monitoring, contact EPA's Monitoring and
Reports Branch at (919)541-5652.
4.3.2.3 Co-Control Opportunities
Once specific air toxics concerns have been identified, to the extent time and
resources allow, S/L agencies are encouraged to develop and implement appropriate
co-control measures. In urban areas these measures might emDhasize the control of
specific source categories and ooilutants. and particularly area sources. Outside urban
areas the focus of co-control might be more on the control of specific large point
sources. Several types of co-control measures to address this range of air toxics
concerns are discussed below.
Within existing legislative authorities, ongoing EPA regulatory efforts for
criteria and noncriteria pollutants will contribute toward the future reduction of air
toxics levels. Continued implementation of existing S/L and Federal requirements will
also reduce PM and VOC emissions which are likely to contribute to the current air
toxics problem. Despite these efforts, inadequate progress on the air toxics problem
will, in many cases, lead some S/L agencies to adopt significant additional mitigation
measures for toxics. Any co-control measures adopted by a S/L agency for mitigating
PM and VOC air toxics for any given area will depend on such factors as the number
and type of sources, the types and quantities of pollutants emitted, ambient
concentrations of pollutants, and the costs of control (as well as local political,
economic, and legal considerations). The S/L agency will need to make these
decisions based on their own individual policies regarding acceptable ambient levels
and risk management, as well as what otherwise will happen under Federal programs.
Following is a discussion of several candidate co-control measures for
consideration by S/L agencies. These measures represent a starting point for the
consideration of approaches to mitigating risks from exposure to air toxics. Where a
measure might involve a source category which is under consideration for a national
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measure might involve a source category which is under consideration for a national
standard, coordination with EPA is recommended to understand the most recent
information regarding possible overlap prior to the adoption of this measure.
For the most part, the candidate co-control measures described below do not
include new or necessarily innovative ideas. The list does, however, identify the
mitigation measures that appear to offer the best prospect for reducing the cancer and
noncancer risks of exposure to PM and VOC air toxics, particularly in urban settings,
As the understanding of the air toxics problem improves, new approaches may
emerge. Additional ideas for co-control should come from future field and research
experience. For example, the control of condensible paniculate matter (now
implemented by several S/L agencies and being researched by EPA) may well
accomplish co-control objectives for certain source categories.
1. More Intense Audit and Enforcement of Existing SIP Requirements.
Analyses show that considerable indirect control of air toxics can be achieved
through intensified efforts to enforce existing SIP requirements. Aggressive auditing
and enforcement of regulations for VOC and PM sources, which also emit toxic
pollutants, can be a cost-effective means of minimizing emissions of air toxics from
new and existing sources. An intensified enforcement effort aimed at sources of air
toxics could include:
(1) compliance audits of selected high priority sources (e.g.,
those emitting significant amounts of high priority
pollutants, sources with a history of poor compliance, etc.);
(2) increasing the number of enforcement source inspections;
(3) step-up of enforcement actions against noncomplying
sources which emit air toxics;
(4) evaluation of facilities most likely to experience process
upsets or control equipment malfunctions;
(5) strengthened source monitoring requirements;
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(6) greater use of opacity monitoring as an enforcement tool; and
(7) expanded coverage of ambiguous VOC regulations to sources not
previously judged to be covered by those regulations.
2. Selection of Additional PM and VOC SIP Co-Control
Measures.
Revision of existing PM and VOC SIP's will be necessary in many areas to
attain and/or maintain the PMjQ and ozone NAAQS. Control strategies that offer
significant air toxics benefits and, at the same time, satisfy PM,0 or ozone plans
should be given serious consideration over those that do not enhance air toxics
control. Also, there may be measures that are marginal from an ozone or PM,0
perspective, but which can be further supported on the basis of the payoff of
additional toxics control. For example, it has been shown that VOC can degrade in
the atmosphere to form formaldehyde; therefore, any additional control of VOC from
stationary or mobile sources could result hi lower ambient levels of formaldehyde.
3, Adoption of Control Measures in SIP's for Sources/Pollutants Not
Included.
Consideration should be given to identifying and adopting control measures for
sources or pollutants not currently covered under SIPs. Numerous small sources
which are potential emitters of toxics are often exempt from S/L permit requirements
(e.g., degreasers or miscellaneous metal or plastic coating operations). Also, sources
not presently required to apply Reasonably Available Control Technology (RACT)
could be controlled to RACT levels if they are sources of air toxics (e.g., spray
painting bridges with chromate paints). Thirdly, consideration should be given to the
control of VOCs which could be exempt, under current regulations, because of
negligible reactivity (e.g., small furniture refinishing businesses using methylene
chloride as a paint stripper). Finally, some sources and/or source-related operations
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are exempted within SIPs (such as peaking power units and malfunctions), and these
exemptions should be reexamined in light of their toxics implications. Control of each
of these sources may not have been justifiable previously on the basis of criteria
pollutants control, but may be worthy of consideration under a co-control program to
address air toxics.
4. Nontraditional Squrces and Control Strategies.
An examination of the itrban air toxics problem reveals that, in many instances,
nontraditional sources of air pollution may be major contributors to the problem. In
turn, this conclusion suggests chat solving the problem may call for the adoption of
some less traditional control strategies.
Acting to increase public awareness can be a cost-effective means of minimizing
PM and VOC and toxic emissions from area sources such as woodstoves and solvent
use and disposal. Woodstove emissions are a major source of toxic air contaminants
and PMj0 in many urban areas. High concentrations of polycyclic organic matter
(POM) emissions resulting from woodstove and fireplace emissions have been shown
to result in significant seasonal cancer risks hi some areas. Also, potential
nonattainment areas for PMj0 may need to achieve reductions in wood smoke
emissions to demonstrate attainment of the PMj0 NAAQS.
A cost-effective means of minimizing risks from wood smoke may be education
of woodstove owners about proper operation of woodstoves. Such a public education
effort has been implemented in some areas, and EPA is considering a public
education campaign in conjunction with the NSPS for woodstoves. Using materials
presently available from EPA (e.g., woodstove pamphlet included in the back of this
document), S/L agencies could, for example, advise woodstove owners of ways to
reduce woodstove emissions (e.g., small, hot fires; seasoned wood; appropriate size
stoves operated at efficient levels; catalytic combustors) or eliminate woodstove use at
certain times, such as during inversions.
Another area where public education can play a role in minimizing air toxics
and VOC emissions is in the handling and disposal of solvents. A number of toxic
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organics (such as trichloroethylene, chlorobenzene, and nitrobenzene) escape into the
atmosphere in the form of fugitive emissions as a result of improper solvents disposal
by individuals and small businesses. Because the use of solvents is widespread in
urban areas, improper handling and disposal practices can be a significant contributor
to air toxics and VOC loadings. A reduction in such VOC emissions may help areas
that are currently nonattainment for ozone.
State and local agencies may also want to consider a program to identify small
businesses that commonly use solvents and educate them, as well as the general
public, about good solvent handling and disposal practices. In some areas, local
solvent recycling programs and recycling cooperatives have been initiated to address
this need. The effectiveness of such measures will depend on the amount of effort
and resources applied, the attitudes of the public and small business community
concerning air pollution and environmental protection, and the expense and
inconvenience of recommended disposal methods versus traditional methods. An
effective public education campaign about solvent usage and disposal has the potential
to reduce risks from air toxics exposure for a relatively small investment of public and
private resources.
Because health risks to the public 'arise from a variety of sources and through
a multitude of pathways and media, a more integrated approach to controlling urban
air toxics may be warranted. For example, the influents and effluents of public
wastewater treatment plants are indicated as a sizeable source of air toxics, especially
those that receive discharges from chemical plants. Rather than directly controlling
emissions at the wastewater treatment plan itself, pollution prevention measures such
as industrial pretreatment programs aimed at reducing the discharge of organics into
public sewer systems, and the subsequent intermedia transfer of organics to the
atmosphere, may be more appropriate. Such an integrated, multimedia approach can
target the pollutants and sources posing the greatest overall risks to the public,
regardless of the particular environmental medium involved. Good communication
and coordination between Federal, State and local agencies is crucial to the success of
an integrated, multimedia approach such as this.
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43-3 Coordinating with Other Toxics-Related Programs
Coordination opportunities in the establishment of air toxics programs exist
with several other program areas in addition to SEP programs for PM and VOC. The
most prevalent programs offering air toxics benefits through coordination are the
SARA Title HI program, the RCRA/CERCLA program, OSHA programs, and the
Clean Water Act program. The generic opportunities for coordination within each of
these programs are described in the following sections, with examples given where
specific States have successfully implemented such coordination. Table 4-2 provides
contacts for information related to other toxics-related programs.
4JJ.1 SARA Title III Regulations
The SARA Title HI provisions, also known as the "Emergency Planning and
Community Right-to-Know Act," can provide a great deal of information that is
pertinent to the air toxics control program. Successfully coordinating the data
available from SARA Title HI with the information needs for an air toxics program
can lower the resources otherwise required for the air toxics initiative.
Several portions of the SARA Title ffl program have relevance to an air toxics
initiative. The sections that can provide the most data and have the greatest impacts
on air toxics program development are Sections 304, 311, 312, and 313.
The foundation of the SARA program is to provide EPA, S/L agencies, and
the public with information regarding the storage, use, manufacture, or release of
certain chemicals designated as hazardous. The EPA has established a list of
hazardous chemicals for which reporting must be done. The list currently numbers
over 400 chemicals and is expected to grow over time. The 400+ hazardous
chemicals are characterized as being toxic and/or extremely hazardous, which roughly
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corresponds to chronic and/or acute health hazards, respectively.
Reporting under the SARA Title HI provisions is due annually by July 1,
beginning in 1988. The EPA is currently evaluating responses received, performing
quality assurance checks, and developing a computerized data base of information that
is accessible by S/Ls through the National Computer Center in Research Triangle
Park, North Carolina. In addition, States are also receiving the SARA Title m
submittals and data compilations. In some cases, private groups such as the Natural
Resources Defense Council, the American. Lang Association, and the Sierra Club have
analyzed and summarized State data. Such analyses will likely be available to S/L
agencies and could provide information that could save agency resources for toxics
program development. The SARA Title HI data are also available through the
National Library of Medicine and tne NATICH database (see Table 4-2.)
Perhaps the most important part of SARA Title HI from an air toxics program
standpoint is Section 313. This section pertains to uniform toxic chemical release
reporting that must be done by industrial facilities meeting certain criteria. The
reports are filed with EPA and State authorities. The Section 313 requirements apply
to facilities that:
o employ 10 or more persons full time,
o are in Standard Industrial Classification (SIC) Codes 20 through 39 (as
in effect on July 1, 1985), and
o in the calendar year for which a release form is reauired. manufactured,
processed, or otherwise used a toxic chemical on the list described below
in amounts greater than those specified.
The toxic chemicals subject to the release reporting requirements are given in
the EPA publication 'Toxic Chemical Release Inventory Reporting Form R (EPA-
560/4-88-005). The EPA is continually evaluating and updating this list such that
chemicals may have been added or deleted since the publication of this report. The
final determination on whether a chemical release must be reported is based on
established reporting thresholds. For toxic chemical use at a facility, all uses of
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10,000 pounds per year or greater require Section 313 release reports. For toxic
chemical manufacture or processing, the release reporting thresholds are
75,000 pounds per year for all forms due on or before July 1, 1988, 50,000 pounds
per year for forms due on or before July 1, 1989, and 25,000 pounds per year for all
forms due on or before July 1, 1990 and thereafter.
The Section 313 chemical release form (Form R) provides the name, location,
and primary business activities of a subject facility. For each listed toxic chemical
emitted by the facility, the following data must be provided:
o Whether the toxic chemical at the facility is manufactured, processed, or
otherwise used, and the general category or categories of use of the
chemical.
o An estimate of the maximum amounts, in ranges, of the toxic chemical
present at the facility at any time during the preceding calendar year.
o For each waste stream, the waste treatment or disposal methods used,
and an estimate of the treatment efficiency typically achieved by such
methods for that waste stream.
o ~ The annual quantity of the toxic chemical entering each environmental
medium.
The usefulness of the Section 313 data in the problem definition and program
implementation phases of an air toxics control program are readily apparent. Not
only are potentially significant sources identified by the pollutants emitted, but
emission quantities are also provided. Indications of the potential for improvements
in control device use and efficiency are provided. The data can also be used as a
parallel enforcement tracking measure. Similarly, Section 313 reports can be used to
potentially measure the effectiveness and progress of the air toxics control program in
reducing overall airborne emissions.
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43.3.2 RCRA/CERCLA Regulations
The Resource Conservation and Recovery Act (RCRA) and the Comprehensive
Environmental Responsibility, Compensation, and Liability Act (CERCLA) are two
Federal control programs that can provide information useful to air toxics control
efforts. Both RCRA and CERCLA were originally designed as control programs for
hazardous wastes, particularly hazardous wastes that were being disposed of by land
treatment means (e.g., landfills, deep well injection, etc.). However, through the
Hazardous and Solid Waste Amendments of 1984 (HSWA) and SARA, both control
programs have expanded their scope in addressing hazardous waste management and
disposal. Toxic air emissions from hazardous waste incinerators are covered.
Multiple toxics emission points from comprehensive hazardous waste treatment,
storage, and disposal facilities (TSDFs) have been investigated for regulation jointly by
EPA's air and hazardous waste offices. Regulations limiting volatile organics releases
have been proposed (52 FR 3748) for TSDFs. Potential toxic air emissions occurring
during site clean-up operations are being estimated and potential risks determined
under the CERCLA Superfund program. A significant amount of information may be
available from these programs that could aid S/L agencies in the problem definition
and implementation phases of an air toxics control program.
One of the primary benefits of the RCRA/CERCLA programs is to help
identify what sources handle substances deemed to be toxic. The RCRA regulations
(40 CFR, Part 261, Subpart D) contain six categories used to classify chemical wastes.
These six are toxic, acutely hazardous, EP toxic (Extraction procedure-Method 1310),
reactive, corrosive, and ignitable. Though the lists are dynamic and continually under
review, the toxic and acutely hazardous lists combined currently include over
600 substances. Sources handling RCRA-listed wastes must conform with specified
treatment, disposal, and reporting requirements. The data produced by these
reporting requirements would be useful in denoting facilities handling substances of
concern and flagging potential air toxics emitters. Information may also be provided
that could be used to calculate emission estimates.
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Other work done by hazardous waste agencies may provide similar types of
information that would be beneficial to air agencies. Inventories of TSDFs have been
prepared by EPA and States for various purposes including the development of
regulations for TSDF air emissions. These inventories can provide much useful
information for problem definition purposes. Similarly, permit information, namely
RCRA Part B permits, can provide useful data on what industrial sources (not just
TSDFs) handle RCRA-listed wastes, and therefore may be sources of air toxics. In
most cases, Part B permits would provide sufficient data to calculate toxics emission
estimates.
The Superfund National Priorities list (NPL) program can also provide a data
on of air toxics emissions from hazardous waste clean-up sites. The provides Hazards
Ranking System (HRS) used for NPL listing data on sites that may present significant
risks until clean up. It does not provide much data on currently active TSDFs as air
toxics sources. Through the HRS, Superfund sites are evaluated and ranked according
to their overall health risk potential. Several hundred chemicals are listed by
CERCLA (40 CFR Part 302) as being hazardous and are evaluated by the system.
The overall evaluation includes multimedia exposure routes and exposures from the
site during clean-up operations. The rankings are used to prioritize clean up initiation
among sites nationwide. The HRS provides a substantial amount of information that
effectively defines the extent of the health risk at a particular site. This information
can be useful to a S/L agency in defining regulatory and control strategies for all
such sites in their area.
In terms of program implementation, routine source reporting requirements
under RCRA may have some benefits and use for tracking and monitoring air toxics
emissions and compliance with air toxics regulations. It is possible the RCRA reports
could be used as one means of enforcement. An air agency may be able to make
use of the reported data either as is or by adding minimal additional questions to the
routine reports, and accomplish its monitoring/enforcement goals. As with any
coordination activity, extensive communication and initial planning will be necessary to
gauge feasibility and ensure smooth operation.
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43.3.3 OSHA Regulations
Regulations of the Occupational Safety and Health Administration (OSHA) can
produce information beneficial to air toxics control program development The
primary benefits of OSHA are the identification of sources potentially emitting toxic
compounds, the estimation of emissions rates and related process information, and the
identification of control options for various processes and pollutants. In some cases
air toxics control efforts may be able to piggyback on OSHA regulatory initiatives.
The primary objective of OSHA programs is worker protection from unsafe
activities, including exposure to toxic chemicals. By limiting the amounts of a
chemical that may be released into the workplace, some OSHA regulations may
indirectly benefit air toxics control. For example, OSHA places very strict limits on
the amount of toxic arsenic trioxide (As^ Q) that arsenic acid production workers may
be exposed to. As a result, all domestic manufacturers of arsenic acid have installed
sophisticated capture and collection systems for arsenic trioxide dust. The benefit of
these systems has been to greatly lower both workplace and ambient air arsenic
trioxide releases.
Over 500 chemicals are regulated by OSHA in the workplace (29 CFR,
Part 1910, Subpart 2). As a part of its Hazards Communication System, OSHA
requires facilities to make available to employees and others, Material Safety Data
Sheets (MSDS) for the chemicals present in the workplace environment. An
assessment of facility MSDSs is a quick and easy way to determine what chemicals
are present at a plant and which have potential for emission into ambient air. The
OSHA also conducts special studies of particular processes/source categories to
estimate chemical release rates and possible control measures. For example, studies
have been conducted to estimate hexavalent chromium releases from electroplating
processes and possible control options. Studies such as this and others, by groups
such as the National Institute for Occupational Safety and Health (NIOSH), may be
able to provide S/L air agencies with insightful information for problem definition and
control strategy development phases of air toxics programs.
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4.3.3.4 Clean Water Act Regulations
The principal value of coordination with the Clean Water Act (CWA) program
is the potential identification and association of toxic chemicals of concern with
specific plants and general industrial processes. Such associations may be indicative of
potential air toxics emissions sources. The CWA program can also indicate what
facilities have wastewater streams containing toxic chemicals of concern. Some of
these chemicals may be ones that are readily volatilized and present air toxics .
problems. Sufficient CWA information may be available on toxic chemical loadings
and discharge volumes to quantify air emissions.
The utility of CWA program information on air toxics control program
development is probably much less than SARA Title HI or RCRA, but the potential
information overlap and coordination opportunities should not be overlooked.
4.4 MEASURING PROGRAM EFFECTIVENESS
The purpose of this subsection is to describe various techniques for measuring
air toxics control'program performance. The goal of this subsection is to present
general criteria for the design of an effective program performance measurement
system and to provide some example measurement techniques.
4.4.1 Need for an Air Toxics Program Performance Measurement System
Like criteria pollutant control programs, air toxics control programs have a
need to assess their overall progress and effectiveness relative to specific program
goals. For reasons of internal agency accountability, accountability to the legislature
or local board/commission, and accountability to the general public, S/L agencies are
commonly required to document the progress and effectiveness of their air pollution
control programs. In addition, agencies are required to document program activities
to qualify for grant funds from EPA (e.g., Clean Air Act Section 105 grants).
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Program effectiveness measures also need to be considered right from the start during
program design, and not as an afterthought
Progress toward achievement of program goals can be categorized as
administrative progress and control effectiveness. Administrative progress includes
development of regulations, policy, or guidelines, the number or percent of sources
inventoried, the number of multiyear development plan (MYDP) milestones met, the
number of hiring and resource acquisition objectives achieved, or the number/percent
of source reviews completed.
Control effectiveness refers to the results or "environmental payoff of program
implementation. This may include such items as the reduction in complaints, actual
emission reductions, the amount of reduction in ambient concentrations of air toxics,
or the reduction in public health risks.
Care needs to be taken to ensure that the measure being used to evaluate
effectiveness is consistent with the goal being measured. For example, the
effectiveness of a program that has a goal of developing and adopting an air toxics
regulation is best measured through administrative progress and not control
effectiveness. Obviously, since in this case the regulation has only been adopted and
not yet implemented, one would expect little progress in control effectiveness
measures. Measuring the effectiveness of this program through a control effectiveness
measure (e.g., risk reduction) would indicate that the program was not effective even
though it was successful in meeting the stated goal (i.e., adopting a regulation).
In developing a system for measuring the performance of an air toxics program,
a S/L agency can and should draw upon the considerable experience it has acquired
in tracking criteria air pollutant control programs. However, because of the human
health ramifications of air toxics program, the measures of administrative progress and
control effectiveness and the implications of the lack of progress and control are
unique for air toxics programs in several respects. First, the pollutants involved are
different and more numerous than in criteria programs. Second, programs that
include a goal of reducing public health risks to a specified level may need to
measure decreases in exposure and risk levels. Third, programs including acceptable
ambient guidelines or standards need to include measures of progress in reducing air
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toxics concentrations below those levels. Finally, S/L agencies receiving EPA grant
funds for air toxics program development are required to report their progress
according to special EPA program oversight procedures (ie., MYDP milestones).
The ultimate goal of a performance measurement system is to measure
program results. Needless to say, it is possible to expend a great deal of time,
energy, and resources on an air toxics program with few or no measurable results.
Therefore, S/L agencies and EPA need to be able to determine if any real progress
in regulating air toxics is occurring as a result of S/L agency air toxics program
activities.
Measurement of environmental payoff is a difficult (and expensive) aspect of an
air toxics program to measure. For example, measurement of reductions in air toxics
emissions actually achieved in practice can be either speculative or expensive to
determine. Consequently, tracking systems designed to measure program performance
may focus initially on administrative progress or on more qualitative measures
performance, rather than on control effectiveness measures. Accordingly, a primary
characteristic of systems to measure the performance of air toxics programs is a
graduated approach to measuring administrative progress and control effectiveness.
This graduated approach to tracking program performance is based on measures that
range from the easiest to measure and most qualitative hi nature to the most difficult
and quantitative. As a program is implemented and matures, an agency should be
able to measure program performance through use of increasingly more quantitative
and results-oriented indices.
4.4.2 Performance Criteria
Design of performance criteria should consider the following:
(1) Measure progress/effectiveness relative to program goals.
Progress/effectiveness measurement is a function of the primary
program goals and the basic design of the program. As such,
program performance measurement should provide information
related to the achievement of program goals. As such, program
performance measurement should provide information related to
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the achievement of program goals. For example, some programs
will want to show quantitative reductions in emissions to specified
levels. The system should also be flexible enough to
accommodate new goals and changes in program design that occur
over time.
(2) Measure progress/effectiveness both qualitatively and
Q\13fltit3flv?]y- Both qualitative and quantitative measures are
necessary to fully evaluate a program's performance relative to its
goals. Qualitative measures might include, for example, an
evaluation of the program's overall progress in meeting program
goals. Quantitative measures might include tracking the number
of sources reviewed for air toxics each year, the number of
sources inventoried, or reductions in the maximum individual risk
(MIR) or incidence of cancer near high risk point sources
(HRPS).
(3) Focus on the four National Air Toxics Strategy themes.
The four themes of EPA's 1985 National Air Toxics
Strategy provide a good focus for a performance
measurement system. The themes include: (1) acceptance
of NESHAP delegation, (2)addressing HRPS, (3) addressing
high risk urban areas, and (4) enhancing S/L agency
capability. Thus, for example, the system should measure
progress in reducing emissions and risks associated with
HRPS or the progress in accepting delegation of authority
for enforcing NESHAP regulations.
(4) Use available sources of data. Several sources of information are
available that may be useful in designing an effective program
performance measurement system. These include NATTCH, the
1989 STAPPA/ALAPCO survey of air toxics programs, and
various EPA and State monitoring programs such as the Non-
methane Organic Compound (NMOC) Monitoring Program.
These and other sources of information can provide useful
information that can be used as baseline measures.
(5) Include measures of agency capabilities to compare with oiher
agencies. To allow an assessment of the investment in air toxics
control over time and relative to the magnitude of the problem,
measures of agency capabilities should be incorporated into any
program tracking system. Such information can be used by S/L
agencies for direct comparison to the investment levels of agencies
in other States with comparable air quality programs, and by State
agencies for comparison of investments in local agencies in their
jurisdiction.
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(6) Provide for flexibility and feedback. The performance tracking
system should be flexible enough to accommodate new sources of
information, new data collection techniques, and new goals. In
addition, the system should provide feedback from the evaluation
of program performance so that modifications in program goals or
implementation can be made.
4.4.3 Example Measurement Techniques
No one measure of program progress can provide an accurate and
comprehensive indication of results. Consequently, a combination or series of
measures is necessary to comprise an effective performance tracking system.
Table 4-3 is a checklist of possible program progress and effectiveness
measures. The checklist is grouped according to administrative progress (or program
activity-oriented) measures and control effectiveness measures. Several of the
measures expressed as "number of could be expressed as percentages. The list is not
intended to be exhaustive, but may serve to illustrate a number of program
performance measures. __
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TABLE 4-3. EXAMPLE PROGRESS MEASUREMENT TECHNIQUES
Administrative Progress Measures
1. Number of MYDP milestones achieved.
2. Number of sources inventoried/surveyed.
3. Number of sources reviewed for air toxics.
4. Number of sources modeled (screening and/or detailed).
5. Achievement of major program goals (e.g., completion of draft regulations,
approval of regulations, hiring of budgeted personnel, etc.)
Control Effectiveness Measures
1. Number of sources meeting AAL, target risk level, or control technology
requirements.
2. Number of sources installing controls or making process changes for air toxics
beyond what would otherwise~be required for criteria pollutants.
3. Number of listed pollutants for which all sources are in compliance.
4. Number of HRPS in compliance.
5. Measurable risk reductions for HRPS (MIR and/or incidence).
6, Reductions in the volume of SARA Title HI toxic air releases.
7. Improvements in monitored ambient conditions in high risk urban areas, (not
otherwise due to industry shutdowns,curtailments, or reductions hi mobile
sources activity)
8. Achievement of major program goals related to results.
9. Number of air toxics-related complaints reviewed.
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TECHNICAL REPORT DA-TA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-450/2-90-012
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Designing and Implementing an Air Toxics Control
Program: A Program Development Manual for State and
Local Agencies
7. AUTHOR(S)
5. REPORT DATE
JUILI 1990
6. PERFORMING ORGANIZATION COOE
OAQPS
8. PERFORMING ORGANIZATION REPORT NO
Martha H. Keating and Michael A. Trutna (U.S. EPA)
I. PERFORMING ORGANIZATION NAME AND ADDRESS
Radian Corporation
P.O. Box 13000
Research Triangle ?ark,NC 27711
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME ANO ADDRESS
Noncriteria Pollutant Programs Branch
Air Quality Management Division
Office of Air Quality Planning and Standards
13. TYPE OF REPORT ANO PERIOD COVERED
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This manual is intended to assist State and Local air pollution control agencies
in making informed decisions about the development of air toxics control programs
and to enhance consistency among the State and local program approaches. In
particular, insight is provided into how to make critical decisions regarding
program scope and stringency, evaluation of program impacts, and achievement of
overall program goals. The manual addresses these issues by illustrating the
experiences of State and local agencies and EPA in making air toxics program decision:
The manual was developed by seeking the advice and experiences of State and local
agencies in various stages of their own program development. While this information
does not represent EPA policy, it should prove useful to many State and local
agencies now actively engaged in air toxics program development.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Air toxics
State and local programs (air toxics)
Program development (air toxics)
Air toxics strategies
Control of air toxics
18. DISTRIBUTION STATEMENT
19. SECURITY CLASS (Tins Report/
21. NO. OF PAGES
144
! 20. SECURITY CLASS (This page I
22. PRICE
EPA form 2270-1 (R«». 4-77) PREVIOUS COITION is OBSOLETE
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