[Federal Register Volume 63, Number 177 (Monday, September 14, 1998)]
[Notices]
[Pages 49240-49258]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-24335]
[[Page 49239]]
_______________________________________________________________________
Part III
Environmental Protection Agency
_______________________________________________________________________
Draft Integrated Urban Air Toxics Strategy To Comply With Section
112(d), 112(c)(3) and Section 202(l) of the Clean Air Act; Notice
Federal Register / Vol. 63, No. 177 / Monday, September 14, 1998 /
Notices
[[Page 49240]]
ENVIRONMENTAL PROTECTION AGENCY
[FRL-6157-2; Docket No. A-97-44]
Draft Integrated Urban Air Toxics Strategy To Comply With Section
112(k), 112(c)(3) and section 202(l) of the Clean Air Act
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice.
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SUMMARY: This notice provides a draft strategy for public comment to
address health impacts from air toxics in urban areas. The strategy
includes a draft list of 33 hazardous air pollutants (HAP) judged to
pose the greatest potential threat to public health in the largest
number of urban areas, based on available information. Thirty of these
HAP are from area sources. It also provides a draft list of area source
categories to be listed for regulation under section 112(d) of the
Clean Air Act (Act). The draft strategy also provides a schedule for
specific actions to address risk from air toxics in urban locations.
This draft strategy is being developed as required in section 112(k)
and 112(c)(3) and section 202(l) of the Act, as amended in 1990, and a
consent decree entered in Sierra Club v. Browner, Civ. No. 95-1747
(D.D.C. 1995) (consolidated with Sierra Club v. Browner, Civ. No. 96-
436 (D.D.C. 1996)). Even though the draft strategy identifies source
categories for which additional standards under section 112(d) may be
developed, the strategy by itself does not automatically result in
regulation or control of emissions from sources within these source
categories. The EPA will perform further analyses of HAP emissions,
control methods for the listed source categories, and health impacts as
appropriate, for stationary and mobile sources. These analyses will
determine the ultimate regulatory requirements, if any, which may be
developed under the strategy.
DATES: A draft and final strategy, including HAP and source category
lists, are required under the consent decree to be completed and made
available by August 31, 1998 and June 18, 1999, respectively. Written
comments on this draft must be received by November 30, 1998. We will
hold four stake-holder meetings on this draft. The first will be at
Radisson Plaza Hotel at Mark Center, 5000 Seminary Road, in Alexandria,
VA on September 23, 1998. The second at the Durham Marriott at the
Civic Center, 201 Foster Street, Durham, NC on September 29, 1998, the
third, in Chicago, Illinois at Hyatt Regency Chicago, 151 East Wacker
Drive, Chicago, IL 60601 on November 5 and 6, 1998, and the final at
Cathedral Hill Hotel, 1101 Van Ness Avenue, in San Francisco,
California 94109, on November 19, 1998. Persons wishing to present oral
comments pertaining to this notice should contact EPA at the address
listed below.
ADDRESSES: A docket containing information relating to the development
of this notice (Docket No. A-97-44) is available for public inspection
and copying between 8:00 a.m. and 5:30 p.m., Monday through Friday
except for Federal holidays, in the Air and Radiation Docket and
Information Center (MC-6102), Room M-1500, U.S. Environmental
Protection Agency, 401 M Street, SW, Washington, DC 20460; telephone
(202) 260-7548. A reasonable fee may be charged for copying.
FOR FURTHER INFORMATION CONTACT: Laura McKelvey, Office of Air Quality
Planning and Standards (MD-15), U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina, 27711, telephone number (919)
541-5497, electronic mail address: McKelvey.Laura@epa.gov.
SUPPLEMENTARY INFORMATION:
Docket. The docket is an organized and complete file of all the
information submitted to or otherwise considered by the Agency in the
development of the Draft Urban Air Toxic Strategy. The principal
purpose of this docket is to allow interested parties to identify and
locate documents that serve as a record of the process engaged in by
the Agency to publish today's notice. The docket is available for
public inspection at the EPA's Air and Radiation Docket and Information
Center, which is listed in the addresses section of this notice.
In compliance with President Clinton's June 1, 1998 Executive
Memorandum on Plain Language in government writing, this package is
written using plain language. Thus, the use of ``we'' in this package
refers to EPA. The use of ``you'' refers to the reader and may include
industry, State and local agencies, environmental groups and other
interested individuals.
The information in this notice is organized as follows:
I. Introduction
II. List of Pollutants, Effects and Sources
III. Plan for Area Sources (section 112(k))
IV. Near-term Actions to Implement the Strategy
V. Longer-term Plans and Activities to Implement the Strategy for
all Sources of Air Toxics
VI. How EPA will Communicate with the Public on Progress in Meeting
the Strategy's Goals
VII. Regulatory Requirements
I. Introduction
We have made considerable progress since the passage of the Clean
Air Act Amendments of 1990 in improving air quality for all Americans
by reducing air toxics 1 emissions through regulatory,
voluntary and other programs. To date, we have focused mainly on
substantially reducing emissions of toxic air pollutants entering the
environment, primarily by setting standards for major industrial
sources and mobile sources. These reductions are only part of the
solution to protecting public health and the environment from toxic air
pollutants. In addition to lowering overall emissions of these toxic
pollutants, we need to develop focused strategies to combat problems of
particular concern. As we continue to develop the national air toxics
program, and planned research yields improved data on health risks, we
envision making increased use of risk information in setting priorities
and measuring progress.
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\1\ Our use of the terms ``air toxics'' or ``toxic air
pollutants'' in this notice refers specifically to those pollutants
which are listed under CAA section 112(b) as ``hazardous air
pollutants'' or HAP.
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As discussed in more detail in section II.B. current information
shows that some of the greatest health risks affecting the most people
are in urban areas. This Federal Register notice presents our draft
strategy to address the problem of urban air toxics, considering major
industrial sources, smaller ``area'' sources and mobile sources. The
Act requires us to develop a strategy for reducing urban air toxics by
focusing on area sources. However, these sources are not the only
contributors to toxic air pollutants in urban areas and are not the
only sources of concern to the public. Therefore, in addition to
satisfying our statutory obligation to address the threats presented by
emissions from area sources, we intend to devise a broad strategy for
reducing risks posed by air toxics from all sources. Different types of
sources emit the same pollutants; and especially in urban areas, there
are many sources emitting multiple pollutants. As part of our overall
plan to target risk reductions, our draft strategy addresses the
problems of cumulative exposures from air toxics through an integrated
approach that considers all sources.
In developing the urban strategy, we make use of the best available
scientific information providing insight into health risks from
hazardous air pollutants. Based on this information, we have suggested
priorities for the urban air toxics program. Our aim is to achieve the
greatest reductions in risk
[[Page 49241]]
for the largest number of Americans, in an expeditious manner. In
addition, we intend to address cases in which specific groups of
individuals, such as low-income communities and children, may be
exposed to disproportionately higher risks. Available information in
many cases is not sufficient to quantify health risks from air toxics;
there are significant gaps and uncertainties. However, section 112
generally provides a framework requiring the Nation to (1) move ahead
to reduce emissions through standards under section 112(d) or section
129, initially reducing health threats from urban air toxics, while (2)
conducting further research to address uncertainties and improve
information on risks under section 112(f), 112(k) and 112(m) in order
to then act to address the remaining identified risk.
In this introduction, we present a brief overview of the air toxics
problem, actions that we have taken to reduce emissions, and our
overall strategy for dealing with urban air toxics. We view this draft
strategy as a starting point. We welcome public comment and will meet
with various stakeholders, including direct dialogues with community
groups such as environmental justice communities, to develop this
approach further before the final strategy is issued in June 1999.
A. What is the air toxics situation?
There are currently 188 HAP regulated under the Clean Air Act that
have been associated with a wide variety of adverse health effects,
including cancer, neurological effects, reproductive effects and
developmental effects.2 We estimate that approximately 4.4
million tons (or 8.8 billion pounds) of HAP were released in the United
States in 1990, declining to 3.7 million tons in 1993 (Second Report to
Congress on the Status of the Pollution Program under the Clean Air
Act, October 1997). In total, we have issued 25 maximum achievable
control technology (MACT) and two section 129 standards, achieving
estimated emission reductions of approximately 1 million tons once
these standards are fully implemented.
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\2\ Section 112(b) of the Act lists 189 hazardous air pollutants
(HAP). One of the HAP, caprolactam, was subsequently delisted.
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We categorize anthropogenic sources of air toxics into three broad
types: (1) major stationary sources, which are sources that emit more
that 10 tons per year of any one HAP or 25 tons per year of a
combination of HAP, such as chemical plants, oil refineries, aerospace
manufacturers and steel mills; (2) area sources, which are smaller
sources of air toxics which emit less than 10 tons per year of any one
HAP or less than 25 tons per year of a combination of HAP, such as
drycleaners, solvent cleaning industries and secondary lead smelters;
and (3) mobile sources, which include cars, trucks and off-road
engines. According to 1993 data, on a national basis, 24 percent or
about 890 thousand tons of air toxics were emitted by major sources, 34
percent or about 1.26 million tons, were emitted by area sources, and
42 percent, or about 1.55 million tons, came from mobile sources (see
emissions inventory report in docket).
In urban areas, toxic air pollutants pose special threats because
of the concentration of people and sources of emissions. While threats
posed by some pollutants may be fairly common across the country,
studies in a number of urban areas indicate that threats posed by
others vary significantly from one urban area to the next. We are
concerned that because minority and low income communities are often
located close to urban industrial and commercial areas where ambient
concentrations of HAP may be greater, their risks of exposure to HAP at
levels above acceptable health bench marks may be disproportionately
higher than for other segments of the population. Through this study,
we intend to collect and evaluate additional information needed to
determine the extent to which there may be disproportionate risks for
these communities in urban areas.
In order to fully understand the air toxics problem, we must
understand the level of the pollution to which people are exposed. In
order to do this, we would like to know the concentrations of all HAP
as measured by ambient air monitors. However, the monitoring data are
scarce and limited. Consequently, we estimate pollution concentrations
through the use of models, relying on emissions measurements or
estimates.
B. What are we doing to address air toxics?
In amending the Act in 1990, Congress required us to establish
national emission standards for stationary sources of air toxics and to
study a number of air toxics problems to determine whether additional
reductions are needed. These emission standards are known as maximum
achievable control technology, or MACT standards, and generally
available control technology, or GACT standards. We have promulgated
standards for the first 47 of 174 source categories, which will reduce
air toxics emissions by approximately 980,000 tons per year. Within the
next 10 years, as we complete more MACT standards, the air toxics
program is estimated to reduce emissions of toxic air pollutants by
well over 1.5 million tons per year (Second Report to Congress on the
Status of the Hazardous Air Pollutant Program Under the Clean Air Act,
October 1997).
We have also established mobile source evaporative and exhaust
emission standards, as well as fuel standards, which are greatly
reducing the amount of air toxics coming from motor vehicles. Between
1995 and 2000, highway vehicle emissions of benzene, 1,3-butadiene, and
directly emitted formaldehyde will be reduced by about 40,000 tons per
year. Toxic emissions from non-road sources will also be reduced in
this period. Calculations and analyses which will improve our ability
to project the impact of planned mobile source standards are currently
in progress.
Congress instructed us to develop a strategy for air toxics in
urban areas, emphasizing actions to address the large number of
smaller, area stationary sources. Section 112(k)(1) states:
The Congress finds that emissions of hazardous air pollutants
from area sources may individually, or in the aggregate, present
significant risks to the public health in urban areas. Considering
the large number of persons exposed and the risks of carcinogenic
and other adverse health effects from hazardous air pollutants,
ambient concentrations characteristic of large urban areas should be
reduced to levels substantially below those currently experienced *
* *.
In particular, section 112(c)(3) and 112(k) instruct us to:
Develop a research program on air toxics, including
research on the health effects of the urban HAP, monitoring and
modeling improvements to better identify and address risk in urban
areas;
Identify at least 30 HAP from area sources in urban areas
that present ``the greatest threat to public health;''
Identify the area source categories or subcategories
emitting the 30 HAP and assure that 90 percent or more of the aggregate
emissions are subject to standards under subsection (d);
Provide a schedule for activities to substantially reduce
risks to public health (including a 75 percent reduction in cancer risk
attributable to 1990 exposures to HAP emitted by all stationary
sources) using all EPA and State/local authorities;
Implement the strategy and achieve compliance with all
requirements within 9 years of enactment;
Encourage and support State/local programs in reducing
risks within individual urban areas; and
[[Page 49242]]
Provide a Report to Congress at intervals not later than 8
and 12 years after enactment, on actions taken to reduce the risks to
the public health.
In addition, section 202(l) of the Act requires that we:
Study the need for and feasibility of controlling
emissions of toxic air pollutants associated with mobile sources; and
Promulgate regulations containing reasonable requirements
to control HAP from motor vehicles or motor vehicle fuels.
In September of 1995, the Sierra Club filed suit against EPA
alleging that we failed to promulgate regulations to control HAP from
motor vehicles and motor vehicle fuels within the deadlines required
under section 202(l)(2). Subsequently, in March 1996, the Sierra Club
filed another suit alleging that we failed to issue the source category
list under section 112(c) and the strategy under section 112(k) by
their respective deadlines. These were initially separate suits but we
agreed to address both of these requirements as part of a consolidated
consent decree (Defendant's Motion to Consolidate, Sierra Club v.
Browner, (D.D.C. 1996)(N0.99-1747)).
To address the problem of exposure to air toxics in urban areas and
to fulfill our obligations under the consent decree, we intend to
implement an integrated urban air toxics strategy that addresses the
urban air toxics risks from both stationary and mobile sources. This
strategy is expected to produce a set of actions that will be more
responsive to the cumulative risks presented by multiple sources of
toxics and combined exposures to multiple toxics. We believe that by
considering urban air toxics emissions from all sources, we will better
respond to the relative risks posed by any one pollutant and/or source
category. Thus, integration of the activities under both sections of
the Act will more realistically address the total exposure and will
better allow us and the States to develop activities to address risks
posed by toxic pollutants where the emissions and risks are most
significant and controls are most cost effective.
As discussed previously, we have a number of Act requirements to
address. For instance, section 112(k)(3)(B)(ii) and 112(c)(3) require
us to list and regulate area source categories accounting for 90
percent of the aggregate emissions of the 30 HAP identified under
section 112(k)(3)(B)(i). Promulgating these standards is an important
initial step in the strategy to reduce emissions. However, a separate
but equally important requirement of section 112(k)(3)(C) requires us
to substantially reduce the public health risk posed by exposure to
HAP, including a 75 percent reduction in cancer incidence. It is
important to recognize that even though they are linked, because
emissions reductions achieved through standards required under section
112(k)(3)(B)(ii) will help in achieving the risk goals under
112(k)(3)(C), they are two separate requirements. There are also some
important differences between the requirements. For example, section
112(k)(3)(B)(ii) is limited to emission standards for area source
categories emitting the 30 section 112(k) HAP, whereas, section
112(k)(3)(C) refers more broadly to reducing risk from all HAP emitted
by all stationary sources. In addition, standards addressing section
112(k)(3)(B)(ii) must be set under the authority of section 112(d),
whereas the risk reductions to address section 112(k)(3)(C) can be
achieved more flexibly using any of Administrator's authorities under
the Act or other statutes, or those of the States.
C. What is our strategy for addressing urban air toxics?
Today's notice presents our draft strategy for addressing urban air
toxics on a national level and for working with State and local
governments to reduce air toxics risks in our communities. The primary
goal of this strategy is to substantially reduce public health risks
from air toxics. The basic framework of our strategy is to:
1. Define the air toxics threat for urban areas from a cumulative
perspective, considering major, area and mobile sources.
Our implementation of the toxics provisions of the 1990 Amendments
to date has focused on setting technology-based emissions standards for
individual source categories and, separately, developing fuel and
vehicle standards for mobile sources. While we have achieved
significant toxics emissions reductions, including reductions in urban
areas, we believe that a focused urban strategy is needed to address
the ``urban soup'' of multiple toxic pollutants emitted by multiple
sources. In this strategy, we have looked at the contribution from all
sources of air toxics to develop a draft list of the relatively worst
HAP in urban areas. This list of HAP is provided and discussed in
Section II. We plan to use our range of authorities under the Act to
address these problems in the most effective way possible.
2. Improve our understanding of the risks from air toxics in urban
areas.
This draft strategy presents our first steps to characterize
``urban soup'' or the cumulative problem of air toxics in urban areas
and describe how risk can be reduced. As described in more detail in
Section II of this notice, we have analyzed the most significant HAP in
urban areas based on the best available data, including emissions and
toxicity information. To understand the risks from air toxics more
fully, however, we must address significant data gaps. For example, we
have limited information on human health effects associated with many
of the HAP, the extent to which people are exposed to air toxics in
urban areas, and the effect of exposure to multiple pollutants. We will
be providing a brief discussion of our research needs in Section V.
3. Reduce risks from urban air toxics through near- and longer-term
actions.
In addition to the research and other efforts planned to improve
our understanding of air toxics risks, we are suggesting specific
actions that will help achieve emissions reductions in the near-term
and longer-term. For example, as part of our statutory requirements, we
will be proposing air toxics standards for motor vehicles and motor
vehicle fuels, and will begin to develop area source standards by the
end of 1999. From 2002 to 2006, we will issue emissions standards for
these area sources that contribute significantly to emissions of urban
air toxics. In the longer-term, we could also use our residual risk
authority to address major sources that are already subject to
regulation, but which continue to pose substantial risks to urban
areas. More information on these and other actions is found in Section
IV.
4. Work with State and local governments on developing urban
strategies for their communities.
This draft strategy provides a national picture of air toxics in
urban areas, suggests a number of actions that we could take to reduce
toxics emissions, and discusses ways to involve State and local
governments to address toxics risks on the local level. We anticipate
that State and local measures, as well as Federal measures, will be
needed to reduce urban air toxics risks. Urban areas can differ greatly
in terms of air toxics, sources and meteorology. In addition, State and
local programs to address air toxics vary widely; and we recognize that
many States have successfully operated many programs to reduce air
toxic emissions at the State or local levels. Consequently, we intend
to seek collaborative relationships with State and local agencies,
minority and economically disadvantaged communities, and affected
industries to
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assure our actions are responsive to health concerns while promoting
environmental justice, encouraging urban redevelopment, and minimizing
regulatory burdens. We will further encourage and provide enhanced
technical assistance to these States' efforts and will be seeking ways
to expand opportunities for flexible and effective State and local
actions to address risks in more geographically-specific ways.
In this notice, we are suggesting a broad framework for addressing
urban air toxics with some specific actions to reduce emissions and to
improve our understanding of risks posed by air toxics. We will work
over the next several months with various stakeholder groups, including
States, local governments, industry representatives, small businesses,
local health officials and environmental groups to refine this
strategy. In addition, through our Regional Offices, we hope to reach
out to community groups that have not traditionally participated in
these efforts but who may be disproportionately affected by air toxics.
D. What are the components of this Federal Register Notice?
This draft strategy for urban air toxics presents our analysis of
the HAP posing the greatest threats to public health in urban areas,
near- and longer-term actions to address air toxics risks, and a
discussion on developing State and local programs. More specifically:
Section II discusses the health threats posed by air
toxics, describes our emissions inventory and our methodology for
identifying the HAP estimated to pose the greatest threats to public
health in urban areas (based on current information on 1990
conditions), and identifies 33 HAP from all emissions sectors.
Section III focuses on how we are planning to address air
toxics from area sources, as required by section 112(c) and (k),
including a draft list of 34 categories or subcategories of area
sources that account for 90 percent of the emissions of the worst HAP
in urban areas, and that will be subject to additional standards.
Section IV discusses our near-term actions to address
urban air toxics. These include evaluating the need and feasibility for
fuels and vehicle standards, developing area source standards,
reviewing and expanding monitoring networks, developing modeling tools
for national and local scale risk assessments, and beginning to work
with State and local governments to set up air toxic programs. It also
provides information on what EPA and State programs are currently doing
to reduce risks.
Section V describes our longer-term activities to address
air toxics risks in urban areas, including residual risk standards,
additional stationary source standards, and possible State program
actions. It also discusses our research strategy to characterize risks
and to measure progress toward the risks reduction goals of the
strategy.
II. List of Pollutants, their Effects and Sources
A. General Overview
This section provides further discussion of what air toxics are and
what concerns they present, and describes how we evaluated and selected
a draft list of HAP to guide our actions under the strategy. It
includes descriptions of our emissions inventory and our methodology
for identifying the HAP estimated to pose the greatest threats to
public health in urban areas.
In brief, we evaluated the health effects information available for
the 188 HAP, estimated emissions from all known sources using a variety
of techniques, assessed available air quality monitoring data, reviewed
existing studies, and produced a list of pollutants based on the
relative hazards they pose in urban areas when considering toxicity,
emissions and related characteristics. From this effort, we were able
to establish a list of HAP which we believe to pose the greatest
threats to public health in urban areas, considering emissions from
major stationary, area and mobile sources.
B. What are Air Toxics and what threats do they present to public
health?
Toxic air pollutants include a wide variety of organic and
inorganic substances released from industrial operations (both large
and small), fossil fuel combustion, gasoline and diesel-powered
vehicles, and many other sources. The Act as amended in 1990 identifies
188 toxic chemicals as HAP. Major categories of toxic air pollutants
include volatile organic compounds, known as VOC, metals and inorganic
chemicals, and semi-volatile organic chemicals. Volatile chemicals are
usually released into the air as vapor, while semi-volatile organics
and metals may be released in the form of particles.
The HAP have the potential to cause various types of harm under
certain circumstances of exposure (e.g., depending on the amount of
chemical, the length of time exposed, the stage in life of person
exposed). We have classified many as ``known,'' ``probable,'' or
``possible'' human carcinogens and have included this information in
EPA's Integrated Risk Information System.3 The HAP can also
be described with regard to the part of the human body to which they
pose threats of harm. For example, neurotoxic pollutants cause harm to
the nervous system. The severity of harm, however, can range from
headaches and nausea to respiratory arrest and death. The level of
severity differs both with the amount and length of exposure and the
chemical itself (i.e., how it interacts with individual components of
the nervous system). Some chemicals pose particular hazards to people
of a certain age or stage in life. For example, some HAP are
developmentally toxic. That is, exposure to certain amounts of these
chemicals during the development of a fetus or young child can prevent
normal development into a healthy adult. Other HAP are reproductive
toxicants, meaning that they may have the potential to affect the
ability of adults to conceive or give birth.
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\3\ The Integrated Risk Information System (IRIS), prepared and
maintained by the U.S. Environmental Protection Agency (U.S. EPA),
is an electronic data base containing information on human health
effects that may result from exposure to various chemicals in the
environment. IRIS was initially developed for EPA staff in response
to a growing demand for consistent information on chemical
substances for use in risk assessments, decision-making and
regulatory activities. The information in IRIS is intended for those
without extensive training in toxicology, but with some knowledge of
health sciences. Further information about IRIS, including the
information it contains, can be found on the IRIS web site at http:/
/www.epa.gov/iris.
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In a recent effort to characterize the magnitude, extent and
significance of airborne HAP in the U.S. (as part of EPA's Cumulative
Exposure Project or CEP), computer modeling was used to estimate
outdoor concentrations nationwide using a 1990 national emissions
inventory compiled for 148 pollutants from major area and mobile
sources (Woodruff et al., 1998). The estimated outdoor concentrations
for 119 HAP were compared to health-based benchmarks. The benchmarks
for potential cancer effects were set at HAP concentrations which, if
experienced throughout a lifetime, are predicted to be associated with
an upper bound excess cancer risk of 1-in-1 million. The benchmarks for
potential health effects other than cancer were set at exposure
concentrations for each HAP which, if experienced over a lifetime, are
considered to have no significant risk of adverse noncancer effects.
The study looked at more than 60,000 census tracts in the continental
U.S. Census tracts vary in size but typically contain a population of
approximately 4,000.
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It is very important to understand that this modeling estimates
annual average outdoor concentrations for 1990 and does not incorporate
other aspects of exposure modeling, such as differences in
concentrations in various micro environments, indoor air and
individuals' commuting patterns. Thus, the study did not attempt to
estimate the number of people who might be exposed to these estimated
concentrations of HAP, nor the frequency or duration of such exposures.
For this reason, results should be viewed as an indicator of potential
hazard and not as a characterization of actual risk. This effort
suggests that HAP exposures are prevalent nationwide; and for some HAP
in some locations, the concentrations are significant. Concentrations
of eight 4 HAP appear to be greater than their lifetime
excess cancer risk-based benchmarks (10-6 lifetime
individual excess cancer risk) in all of the census tracts, primarily
because of background concentrations (i.e., airborne levels occurring
as a result of long-range transport, resuspension of historic emissions
and natural sources), not just from localized current anthropogenic
emissions. Current anthropogenic emissions, however, appear to
contribute to concentrations of at least two HAP (benzene and
formaldehyde) above the associated benchmark in up to 90 percent of the
census tracts. Further, there are 28 HAP for which estimated
concentrations were greater than the associated benchmark in a larger
number proportion of urban areas than rural areas. In a much smaller
number of locations, concentrations of certain HAP were estimated to be
more than a factor of 100 greater than the corresponding cancer and
noncancer based benchmark.
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\4\ These HAP include: benzene, carbon tetrachloride,
chloroform, ethylene dibromide, ethylene dichloride, formaldehyde,
methyl chloride, and bis(2-ethylhexyl)phthalate.
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We conclude from this analysis that for certain HAP, concentrations
of potential concern are common in all census tracts. Additionally,
there is a subset of the HAP at levels of potential concern in more
urban than in rural areas. This project has highlighted many of the HAP
on which we will be focusing our attention in the urban air toxics
strategy.
C. How did EPA Identify the Priority HAP?
In this section, we present our analysis of what HAP we consider to
pose the greatest threat to public health in urban areas as of 1990.
Although we have limited information on risks, we used the best
available data on air toxics: (1) the National Toxics Inventory, which
provides emissions data on the 188 HAP, combined with information on
toxicity to determine the relative hazard among HAP; (2) monitoring
data available from the Aerometric Information Retrieval System and our
toxics data archive, (3) toxicological information from EPA and other
government sources, (4) an analysis of previous studies on air toxics
in urban area; and (5) the Cumulative Exposure Project analysis of
modeled emissions from 148 HAP by census tracts of the contiguous U.S.
We begin with a discussion of the emissions inventory and then explain
our methodology for picking the HAP in more detail.
1. Emissions Inventory
a. How was the emissions inventory developed?
In order to provide information on all 188 HAP, we are developing
and refining the national toxics inventory. Moreover, in order to
implement the specific requirements of section 112(k), we believed that
it was important to have the best information possible in determining
which of the 188 HAP should be included on the urban HAP list.
Therefore, we conducted an initial ranking analysis based on the
information we had at the time and identified a candidate list of 40
HAP. We provided the candidate list to the public for comment through
the Internet in September of 1997. We developed a national inventory of
sources and emissions for these 40 potential urban area pollutants
considering the information provided by the public for the base year
1990. The base year 1990 was used because it was the year that the Act
was amended and, thus, the year in which EPA received congressional
direction to take actions to address the hazards posed by HAP.
Therefore, we believe that 1990 represents a reasonable starting point
for our analyses and regulatory efforts. The base year inventory report
can be obtained from our Internet World Wide Web site (www.epa.gov/ttn/
uatw/112k/riurban.html). The report notes that current emissions may
differ from emissions calculated for the 1990 base year. We used these
1990 emissions estimates for the urban area pollutants identified in
the next subsection to evaluate what source categories should be
subject to regulation.
The 1990 base year inventory document includes estimates for all
sources of the section 112(k) pollutants for which we could establish
estimation techniques. We believe this base year inventory report will
be a useful reference to those who wish to understand the relative
relationship of stationary source emissions (and in particular those
that have been evaluated for section 112(k) purposes) to emissions from
other types of sources. Therefore, this inventory includes estimates
for sources that we believe would not be subject to section 112
regulations (e.g., mobile sources, fires, and residential fuel
combustion). In addition, where we do not have data to support an
emissions estimate but do have information to suggest a source category
is a potential emitter of a section 112(k) pollutant, we note this in
the inventory document.
Although section 112(k) focuses on area sources, the inventory
provides information concerning both ``major'' and ``area'' sources as
defined in section 112(a) of the Act for each source category, as well
as mobile source categories. This information is important to our
ability to fully characterize risk potential, even though regulatory
decisions under section 112(k) focus on area sources.
To address the requirements of section 112(k), we developed a
national inventory of sources and emissions of the urban area
pollutants based on data collected from the MACT standards program,
Urban Air Toxics Program, the Toxics Release Inventory (TRI), the Great
Waters Study, the Clean Air Act-mandated Reports to Congress on mercury
and electric utility steam generating units, locating and estimating
(L&E) documents used as guides to identify and estimate emissions, and
review of other published technical literature. Emission factors were
obtained from our Compilation of Air Pollutant Emission Factors, Volume
I: Stationary, Point and Area Sources (AP-42) document, our Factor
Information Retrieval System emission factor database, L&E documents,
MACT programs, Federal Aviation Engine Emission Database, and industry
studies. Activity data were obtained from published government reports
(e.g., vehicle miles traveled data from the Department of
Transportation's annual highway statistics, landing and take-off cycles
from the Federal Aviation Administration air traffic statistics, energy
consumption data from Department of Energy publications), industry
trade publications, industrial economic reports, industry trade groups,
and the MACT development programs. With the exception of TRI data, the
inventory primarily represents the product of a ``top-down''
calculation methodology. This means emissions
[[Page 49245]]
were estimated by using some measure of source category activity (on
the national level) and associated emission factors or speciation
profiles for the category and its processes. With a few exceptions
(e.g., use of TRI, emissions data from municipal waste combustors, and
secondary lead refining operations), section 112(k) national emissions
are not the sum of individual facility estimates (i.e., a ``bottom-up''
process). The initial phase of the section 112(k) emissions inventory
effort constituted a screening analysis since we were attempting to
preliminarily quantify atmospheric releases of all sources of the
section 112(k) pollutants. A top-down approach is generally considered
an appropriate and cost-effective use of resources for screening
efforts such as those needed to assess section 112(k) pollutants. The
level of effort required to estimate emissions using a bottom-up
approach for all source categories that emit these pollutants would be
extremely costly. Should it be dictated as a result of this analysis
and listing, such detailed facility-specific emissions information may
be collected during the technical analysis phase of MACT program
development for the source categories listed for future section 112(k)
rulemaking consideration.
b. What is the base year for the inventory?
As noted above, we chose the base year 1990 for the emissions
inventory because we believe that the year the Act was amended
represents the most reasonable starting point for our analyses and
regulatory efforts. Since section 112(k) requires a comparative
accounting of the sources of these specific pollutants, we also
believed it important that, to the greatest extent possible, all
emissions be estimated from the same base year. In several cases, other
and perhaps better, emissions estimates were available that represent
more current emissions levels. In these instances, the more current
estimate was noted, but the 1990 emissions estimate was used for the
section 112(k) accounting of the sources of urban HAP. For example,
lead emissions from gasoline distribution from the refinery to the
storage tanks at service stations (commonly referred to as Stage I) for
on-road mobile sources were estimated to be 0.086 tons in 1990. By
1996, there were no lead emissions from this source due to the mandated
phaseout of leaded gasoline by December 31, 1995. However, the lead
phaseout does not include fuels used for aviation, non-road egines,
marine vessels and automotive racing purposes. Data were insufficient
to estimate the emissions from fuel usage from non-road engines, marine
vessels and automotive racing. For this reason, we are requesting
additional information to help quantify emissions of lead compounds
from these sources.
c. How were pollutants that are regulated as sets of individual
species handled in the inventory?
a. Polycyclic Organic Matter (POM). Various conventions were
adopted for developing the inventory of the pollutant groups where no
standardized methods currently exist. This is most notably the case for
POM, which is defined in section 112(b) of the Act as organic compounds
with more than one benzene ring and a boiling point greater than or
equal to 100 deg.C, which would include a complex mixture of thousands
of polynuclear aromatic hydrocarbons (PAH).
Because compiling the inventory of all POM compounds individually
is currently impossible, surrogate approaches have been used. For
instance, some of the available POM data are expressed in terms of the
solvent-extractable fraction of particulate matter, referred to as
extractable organic matter or EOM. Other POM data are defined as being
included in either the group of seven or group of 16 individual PAH
species, referred to as 7-PAH and 16-PAH, respectively. The species
that make up 7-PAH have been identified by EPA as probable human
carcinogens, and the 16-PAH are those species that are measured by EPA
Method 610. The 16-PAH include the 7-PAH group.
For the purposes of section 112(k), we decided to use 7-PAH as the
POM surrogate because of its more well-established relationship to
health effects of concern. That is, 7-PAH includes 7 specific
carcinogenic compounds, whereas the health significance of the 16-PAH
surrogate is less certain.
b. Dioxins and Furans. In developing the emissions inventory to
support this action, we initially attempted to inventory the specific
dioxin and furan species, but soon found a significant shortage of
available emissions data for these pollutants for all pertinent source
categories. During the data collection phase of the process, we found
that more emissions estimates and emissions factors were available for
dioxins and furans on the basis of 2,3,7,8-TCDD toxic equivalent
quantities (TEQ, 1989 international-NATO). The MACT program, section
112(c)(6) source category list, and the Office of Research and
Development's Dioxin Reassessment Study predominantly report emissions
estimates on a 2,3,7,8-TCDD TEQ basis. Therefore, to maximize the
number of source categories for which national estimates could be
determined on a common basis and best carry out the objectives of
section 112(k), EPA chose to use the TEQ method for developing the
inventory for dioxin and furan species. It should be understood that
TEQs aggregate all of the dioxin and furan species into one value
weighted by toxicity, so that the dioxin and furan emissions estimates
compiled in this inventory include individual species. More information
on the use of the TEQ method can be obtained from the section 112(k)
inventory report (www.epa.gov/ttn/uatw/112k/riurban.html).
d. Why and how were national emissions disaggregated to major and
area source categories?
For the purposes of section 112(k), determining the percentage of a
source category's emissions that come from major sources generally
establishes the percentage subject to a given section 112(d)(2)
standard unless area sources for the category are also listed and
regulated. The allocation of emissions between major and area sources
(major/area splits) used for various source categories in the section
112(k) analysis are a rough approximation based on our current
understanding of the industries concerned. Where specific data
pertaining to major/area splits are available, the splits are typically
derived from definitions of facilities, not necessarily the allocation
of emissions.
Generally, we collect information on the major/area split during
the development of each source category specific regulation by
surveying individual facilities with detailed questions. This section
112(k) study is considered a screening analysis, and we considered
collecting more detailed data for this study to be cost prohibitive, as
well as redundant, since such information will be gathered on a source
specific basis during any subsequent regulatory development. For
information about the specific major/area splits used in the section
112(k) inventory, see Appendix C of the inventory report. We solicit
public comment on the appropriateness of the major/area splits used in
the section 112(k) emissions inventory, as well as the inventory
estimates of emissions. This information will also be on the web.
e. How were national emissions spatially disaggregated?
Section 112(k) of the Act addresses HAP that ``present the greatest
threat to public health in the largest number of urban areas.'' The Act
does not provide a definition of ``urban,'' however. To spatially
allocate emissions on an urban
[[Page 49246]]
and rural basis, we used Bureau of the Census statistical data (U.S.
Bureau of the Census, 1990). The Bureau of the Census lists the
counties included in each Metropolitan Statistical area (MSA) in the
United States. An MSA can include more than one county. We first summed
the county population in each MSA. We designated the counties as urban
or rural based on the sum of their populations. Emissions were assigned
to counties by various methods. In some cases, such as with TRI
estimates and data obtained from MACT studies, emissions could be
assigned to individual facilities and then summed at the county level.
In cases where facility-specific data were not available or could
not be provided in an appropriate format within the time constraints of
this project, emissions were assigned to individual counties using
surrogate approaches. Two examples of these surrogate approaches
include proportioning national non-road vehicle emissions to counties
based on population proportioning emissions from some industrial
sectors to counties based on 1990 SIC code employment estimates. For a
complete list of spatial allocation approaches used in this study, see
appendix C of the section 112(k) Inventory Report on the previously
mentioned web site.
f. How reliable is the inventory?
The emissions inventory developed to support section 112(k)
activities contains data of highly varying specificity and reliability.
In some cases, we or the industry prepared the emissions estimates in
response to other regulatory initiatives. These data are, in several
cases, based on individual facility data or representative, category-
wide data developed from extensive testing. Other more source-specific
estimate data are based on industry-submitted estimates to TRI, which
have been based on testing or process-specific knowledge. Other
estimates were based on a top-down approach utilizing limited emission
factors. Generally, activity data even for these categories were of
reasonably good quality. The emission factor data, however, varied
considerably in terms of number, quality, and representativeness. As
discussed previously, the draft inventory in this notice reflects the
input received.
The section 112(k) 1990 emissions inventory represents the best
data available to the Agency for that period. However, as more source
categories are evaluated during development of rules and more data on
industry activity, emissions factors and source tests become available,
emission estimates should continue to improve. In addition, although
there is currently no requirement for States to collect and/or report
HAP emissions estimates (as there are for criteria pollutant data),
many States are developing data bases for HAP emissions. As these
programs evolve, emissions estimates will improve further.
g. Has this inventory been reviewed by the public?
A draft of the section 112(k) emissions inventory was made
available on EPA's Internet World Wide Web site (www.epa.gov/ttn/uatw/
112k/riurban.html) for review by the public in September 1997. In
addition, we identified a list of trade organizations, industry, and
environmental advocacy groups and contacted them individually by letter
to announce the availability of the inventory and to request their
reviews. The EPA requested that any comments on the September 1997
draft section 112(k) inventory be submitted by October 15, 1997. The
comments submitted were summarized in the EPA document entitled
``Public Comments Received about Technical Aspects of the 1990 Emission
Inventory of Forty Pollutants in the Section 112(k) External Review
Draft Report,'' which can be obtained from the EPA's Internet Web site
mentioned earlier.
2. List of the Priority HAP
a. What are the priority HAP?
Table 1 presents a draft list of HAP that we believe pose the
greatest threat to public health in urban areas. Although information
is limited regarding actual risks posed by specific HAP emissions, the
availability of various other types of information is sufficient to
achieve our objective of identifying those HAP posing the greatest
potential public health concern in urban areas. Even though section
112(k)(3)(B)(i) requires that we list HAP emitted from area sources, we
believe that the public is exposed to complex mixtures of pollutants,
and these pollutants are emitted by all sources. The risk from exposure
to HAP has public health implications regardless of what the source of
the emissions are. We judged these HAP to pose significant health
threats and believe it is important to include them in the strategy to
support activities to achieve the risk reductions required under
section 112(k)(3)(C). Therefore, in the interests of best protecting
public health, we have identified HAP considering the cumulative
exposure potential of mobile, area, and major stationary source
emissions combined. Included on the draft list of urban HAP are those
30 HAP, the identification of which is required under section
112(k)(3), that present the greatest threat to public health and result
from area source emissions. Emissions of only these 30 HAP were
considered in the area source category listing required under section
112(c)(3) and 112(k). As discussed before, those HAP that are emitted
by major or mobile sources, without a significant contribution from
area sources, will be addressed using our other existing authorities
under the Act, such as section 112(c)(1), 112(d) and 112(f) (these HAP
are noted on the table with an asterisk). For example, if there is a
major source category that emits one of these HAP and is not currently
addressed by MACT or section 129, we may determine additional
regulation under section 112(b) is necessary. Alternatively, if the HAP
presents more of a local concern, it may be appropriate for the State
or local agency to address it under its authorities. In light of the
requirement of section 112(k)(3) and EPA's desire to integrate other
statutory requirements regarding air toxics, we are requesting comment
on whether it is appropriate for us to include the HAP that do not have
significant contributions from area sources on the list.
Table 1.--Draft list of HAP for the Integrated Urban Air Toxics Strategy
------------------------------------------------------------------------
------------------------------------------------------------------------
acetaldehyde........................... ethylene dichloride (1,2-
dichloroethane).
acrolein............................... ethylene oxide.
acrylonitrile.......................... formaldehyde.
arsenic compounds...................... hydrazine.
benzene................................ lead compounds.
bis(2-ethylhexyl) phthalate............ manganese compounds.
1,3-butadiene.......................... mercury compounds.
cadmium compounds...................... methyl chloride*.
carbon tetrachloride................... methylene diphenyl diisocynate
(MDI).
[[Page 49247]]
chloroform............................. methylene chloride
(dichloromethane).
chromium compounds..................... nickel compounds.
coke oven emissions*................... polycyclic organic matter (POM)
(7-PAH).
1,4-dichlorobenzene.................... propylene dichloride (1,2-
dichloropropane).
1,3-dichloropropene.................... quinoline*.
2,3,7,8-tetrachlorodibenzo-p-dioxin (& tetrachloroethylene
congeners & TCDF congeners). (perchloroethylene).
ethylene dibromide (dibromoethane)..... trichloroethylene
vinyl chloride.
------------------------------------------------------------------------
The method by which we identified HAP for the urban HAP list is
summarized here and more fully described in the technical support
document in the docket. In order to use the available information in
the most robust manner, we ranked HAP for consideration for the urban
HAP list in the following three ways. First, we ranked HAP by combining
indicators of toxicity and exposure into ranking indices. The
surrogates for toxicity were the risk-based concentration (RBC) for
inhalation or risk-based dose (RBD) for ingestion. For effects other
than cancer, the RBC or RBD represented an exposure estimated to be
without adverse effects in human populations, including sensitive
individuals. For carcinogenic HAP, we used RBC or RBD values
representing both exposures associated with a 1-in-1 million and a 1-
in-10 thousand upper-bound predicted lifetime cancer risks. Surrogates
for exposure included measured ambient concentrations and emission
rates from area, major and mobile sources. As more completely described
in the technical support document, seven separate indices were
calculated, then combined into a single ranking.
Second, we reviewed a number of existing exposure or hazard
assessments concerning HAP that have been conducted previously by EPA,
State agencies and others. Fourteen studies were deemed appropriate for
comparative ranking of HAP in urban areas because they were
sufficiently broad in the pollutants evaluated, they included area
sources of HAP, and they focused on the risks presented in urban areas.
The resultant HAP rankings from each study were normalized to the same
scale, then aggregated to make a total score for each HAP. Carcinogens
and noncarcinogens were ranked separately. Because section 112(k)
places special emphasis on area sources of HAP, analyses were done for
major, area, and mobile sources combined, and for area sources alone.
Third, we used information provided by the CEP which compares
modeled ambient concentrations of HAP in urban areas with health-based
benchmarks. The CEP used estimates of 1990 HAP emissions rates to model
long-term average concentrations at the census tract level for 148 HAP
[Woodruff et al., 1998]. A long-term Gaussian dispersion modeling
approach was used, with emission estimates drawn from TRI and other EPA
databases addressing major, area, and mobile sources. Contributions
from historic emissions of persistent pollutants and from
nonanthropogenic sources were addressed with background values drawn
from measurements in remote locations. The CEP compared its estimated
ambient concentrations to benchmarks corresponding to a one in a
million upper bound estimate of excess lifetime cancer risks, or no
significant risks of adverse noncancer effects. The HAP were
prioritized according to the number of urban census tracts in which the
modeled concentration was above the health based benchmark.
In our selection of urban HAP for the integrated strategy, we
compared and then combined the results of these three separate ranking
analyses. Thirty-one of the 33 urban HAP on the draft list in Table 1
were identified as significant by more than one of these separate
analyses. Two more HAP, mercury and POM were added to the draft list of
HAP. We were concerned that studies considered in the ranking
methodology that we used did not fully consider these two HAP. For
example, multipathway exposure to persistent pollutants was only
considered in one of the ranking methodologies. Therefore, although
mercury was identified by only one of the three analyses, it was added
to the proposed list because it was identified due to food chain
exposures. Moreover, the Mercury Study Report to Congress (December
1997) provides substantial information demonstrating the health and
ecological threats posed by mercury in the environment. Thus, in our
judgement, had multipathway exposure been more fully considered in the
CEP and other studies, mercury would have ranked significantly in them.
The health effect of greatest concern is the neurotoxicity to the
developing fetus associated with methylmercury exposure. Fish
consumption is a principle pathway for human exposure to methylmercury.
Since other forms of mercury are capable of methylation once introduced
into the environment, we do not limit the scope of our regulatory
analyses to methylmercury, but consider emissions of other mercury
species as well. Environmental loadings of mercury which lead to
concentrations in fish result from natural sources, historical
contamination through different media, and from current inputs,
including air emissions. Given the current scientific understanding, it
is not possible to quantify how much of methylmercury in fish consumed
by the U.S. population is contributed by U.S. air emissions relative to
other sources of mercury.5
---------------------------------------------------------------------------
\5\ Critical elements in estimating methylmercury exposure and
risk form fish consumption include the species of fish consumed, the
concentrations of methylmercury in the fish, the quantity of fish
consumed, and how frequently fish is consumed. The typical U.S.
consumer eating fish from restaurants and grocery stores is not in
danger of consuming harmful levels of methylmercury from fish and is
not advised to limit fish consumption. The levels of methylmercury
found in the most frequently consumed commercial fish are low,
especially compared to levels that might be found in some non-
commercial fish from fresh water bodies that have been affected by
mercury pollution. While most U.S. consumers need not be concerned
about their exposure to methylmercury, some exposures may be of
concern. Those who regularly and frequently consume large amounts of
fish-- either marine species that typically have much higher levels
of methylmercury than the rest of seafood, or freshwater fish that
have been affected by mercury pollution--are more highly exposed.
Because the developing fetus may be the most sensitive to the
effects from methylmercury, women of child-bearing age are regarded
as the population of greatest interest. An analysis of dietary
surveys presented in the 1997 EPA Mercury Study led the EPA to
conclude that between 1 and 3 percent of women of child-bearing age
(i.e., between ages of 15 and 44) eat sufficient amounts of fish to
be at risk from methylmercury exposure, depending on the
methylmercury concentration in the fish. These consumers should be
aware of the Food and Drug Administration and State fish advisories
that suggest limiting the consumption of contaminated fish.
Advisories in the United States have been issued by 40 States and
some Tribes, warning against consumption of certain species of fish
contaminated with methylmercury.
---------------------------------------------------------------------------
Given the concentrations of people in urban areas, the numerous
area sources of mercury emissions in those areas, and the resulting
greater potential for people to be exposed to mercury through multiple
pathways, we believe that
[[Page 49248]]
inclusion of mercury in the list of HAP under section 112(k)(3)(B)(i)
is appropriate. However, we are seeking comment on the inclusion of
mercury on this list and whether it is appropriate to identify a HAP
under this subsection based on pathways in addition to inhalation.
Polycyclic organic matter was only evaluated under one of the three
analyses and only partially under another and was added to the proposed
section 112(k) list based upon its identification in one analysis and a
recognition from the scientific literature of its potential hazard. For
POM, we are identifying the 7-PAH surrogate, which is focused on seven
specific carcinogenic species.
One family of pollutants emitted primarily by mobile sources,
diesel exhaust emissions, is not listed in Table 1 but is appropriately
noted here as one which is presently undergoing testing or assessment
by EPA for its role in the urban air toxics problem. Although diesel
exhaust was not specifically investigated in the studies that we used
to select the pollutants which do appear in Table 1, we will be
considering it along with those specific pollutants listed in Table 1
as we develop and implement the integrated urban strategy.
Diesel engines in highway and nonroad mobile sources are numerous
and widespread. There have been recent studies linking diesel emissions
to lung cancer and other health impacts. Diesel engines are a source of
POM which appears on Table 1. However, there may be other constituents
in diesel exhaust that adversely affect health. We have prepared a
draft assessment document on the health risks of diesel emissions and
have obtained comment on it from the Clean Air Science Advisory
Committee of the Science Advisory Board. When this document is
completed, it will inform the further development of the integrated
strategy for urban air toxics. There are area sources which employ
stationary diesel engines, but we are not proposing such stationary
engines for regulation under section 112(k) even though they emit POM
because we do not believe these engines are a substantial urban source
of POM or any of the other pollutants listed in Table 1. Stationary
diesel engines used by area sources located in urban environments are
primarily used only for emergency service and operate infrequently.
b. How did EPA identify the 30 HAP for section 112(k) purposes?
As discussed earlier, section 112(k)(3)(B) of the Act requires EPA
to identify not less than 30 HAP that are estimated to pose the
greatest threat to public health in the largest number of urban areas
as the result of emissions from area sources. Although the Act requires
that these HAP pose threats ``as the result of emissions from area
sources,'' it does not state that such threats be exclusively the
result of emissions from area sources. Therefore, for the purpose of
meeting the requirements of section 112(k) and 112(c)(3), we identified
those HAP that pose the greatest threat to public health in the
analysis discussed above because they ranked highest relative to the
other HAP and because they demonstrated significant contribution from
area sources. By identifying the draft list of 30 HAP as those that
have a significant contribution from area sources, we are ensuring that
the threats posed by those HAP are ``the result of emissions from area
sources.'' Without that contribution from area sources, the threat from
those HAP would not be as great. We judged an urban HAP to meet this
area source demonstration if it was identified in the CEP urban
analysis as having estimated concentrations greater than the health
based benchmark in a significant number of urban census tracts as a
result of area source emissions only, or according to EPA's National
Toxics Inventory, augmented by the section 112(k) inventory, its area
source emissions accounted for at least 5 percent of the total
emissions for that HAP. It is important to remember that these 30 HAP
were used in identifying the draft list of new area source categories
for which standards will be addressed in the future as required by
section 112(c)(3) and 112(k)(3)(B)(ii). The entire list of 33 HAP will
be used to guide actions to meet the requirements of section
112(k)(3)(C).
We are taking comment on the criteria we used in developing the HAP
list including whether it is appropriate for us to include multipathway
exposures as part of this determination; whether it is appropriate to
include more than those HAP with significant contribution from area
sources; and if we should expand the list to include a broader
representation of HAP.
III. Plan for the Area Source Strategy
This section discusses how we intend to use the information
collected in the emissions inventory development and HAP ranking
assessment efforts to address the requirements of section 112(c)(3) and
112(k)(3) to regulate emissions of air toxics from area sources. It
reviews the process of establishing a list of source categories,
identifies those source categories we intend to subject to further
emission standards, and discusses the significance of the listing
processes.
A. How does EPA plan to address area sources of HAP?
One component of the integrated urban air toxics strategy will
address the provisions of section 112(k). The basis for the draft area
source component of the integrated urban air toxics strategy is our
draft list of HAP that, as a result of emissions from area sources,
present the greatest threat to public health in urban areas. Section
112(k)(3) requires that we assure that area source categories or
subcategories accounting for at least 90 percent ``of each of the 30
identified hazardous air pollutants are subject to standards pursuant
to subsection [112](d).'' In addition, section 112(c)(3) specifies that
we list source categories or subcategories representing 90 percent of
area source emissions of the 30 HAP.
These provisions of the 1990 Amendments reflect Congress's judgment
that there are significant health risks from air toxics in urban areas
that should be expeditiously reduced. In addition, these provisions
reflect an understanding that available information is in many cases
insufficient to quantify risks from air toxics. Therefore, we are
directed to identify the pollutants from area sources that, in a
relative sense, present the greatest threat in urban areas and to set
achievable standards to reduce overall emissions of these priority
pollutants of concern. By requiring 90 percent of the emissions of each
of the identified HAP to be subject to regulation, the statute directs
us to seek opportunities for emissions reductions in many industry
sectors. However, the statute provided us with significant flexibility
to determine the stringency of the sector-based standards (i.e., MACT
or GACT standards) and to ensure that they are achievable and
reasonable. To provide compliance flexibility, standards are to be
performance-based (i.e., in the form of numerical emissions limits)
except where infeasible. We will also consider the use of incentives,
nonregulatory programs and other innovative approaches in seeking ways
to reduce emissions and risks from area sources, as well as other
sources addressed by the integrated strategy.
The following presents the analysis of the area source categories
that we are considering listing to meet the requirements of section
112(c)(3) and 112(k). Because this section of the Act imposes
requirements that are specific to area sources, this discussion did not
include an analysis of major or mobile source categories. Any
regulatory
[[Page 49249]]
activities for those categories will be addressed under other Act
authorities.
B. What is a ``listing''?
When we list a source category under the authority of section
112(c), we publicly identify it for regulatory action under section
112(d). As discussed earlier, the details of that regulation, such as
what kinds of controls will be imposed or emission reductions
accomplished, are determined in the subsequent regulatory development
process and cannot be predicted at the time of listing. This strategy
is not considered a rule and does not by itself affect the interests of
any party in a direct or quantifiable manner. Any standards that result
from this listing, however, will undergo full public notice and
comment. We believe that this is consistent with section 112(e)(4) of
the Act which states:
Notwithstanding section 307 of this Act, no action of the
Administrator adding a pollutant to the list under subsection (b) or
listing a source category or subcategory under subsection (c) shall
be a final agency action subject to judicial review, except that any
such action may be reviewed under such section 307 when the
Administrator issues emission standards for such pollutant or
category.
At the time we propose new emission standards for a source category or
subcategory identified in the final strategy, we intend also to request
comment on the section 112(k)(3)(B)(i) listing of the specific
pollutants that serve as the basis for the listing of that category or
subcategory.
C. What is EPA's goal in area source listing?
The stated purpose of section 112(k) of the Act is ``to achieve a
substantial reduction in the emissions of hazardous air pollutants from
area sources and an equivalent reduction in the public health risks
associated with such sources.'' In addition to assuring compliance with
the requirements of section 112(c)(3) and 112(k), our goal in this
draft listing action is to meet the purpose of the urban area source
program in the most effective and least burdensome way possible.
D. What does ``subject to standards'' mean?
In order to subject a source category to standards, we plan to
conduct an evaluation of the source category, then, based on that
evaluation, make rulemaking decisions as to what are the most
appropriate controls or other requirements for that area source
category and publish our findings or promulgate a rule, as appropriate.
This process will take place after publication of the final list of
newly identified source categories. That is, source categories listed
under section 112(c)(3) and (k)(3) will be ``subject to standards''
under section 112(d), but the appropriate controls and resulting
emission reductions will not be known until an area source standard is
subsequently proposed and promulgated.
E. Which area source categories are to be listed?
The following table summarizes which of the additional source
categories EPA intends to list in the final strategy. These categories
are in addition to those already listed for which standards have been
published or are being developed. Attached as an appendix is a table
for each HAP showing the source categories listed. We are requesting
comment on the list of area source categories identified below.
Table 1.--Draft List of Source Categories for Regulation Under Section
112(k)
------------------------------------------------------------------------
-------------------------------------------------------------------------
Abrasive Grain (Media) Manufacturing.
Acrylic and Modacrylic Fiber Production.
Agricultural Chemicals and Pesticides Manufacture.
Manufacture of Nutritional Yeast.
Cadmium Refining and Cadmium Oxide Production.
Chemical Manufacturing: Chromium Compounds.
Electronic and other Electric Equipment Manufacturing (SICs combined).
Food Products (SICs combined) manufacturing.
Gasoline Distribution Stage I.
Hospital Sterilizers.
Industrial Inorganic Chemical Manufacturing.
Industrial Machinery and Electrical Equipment (SICs combined).
Industrial Organic Chemicals Manufacturing.
Instruments and Related Products (SICs combined).
Iron and Steel Foundries: Steel Foundries.
Landfills (excluding Gas Flares).
Mineral Wool Manufacturing (includes Wool Fiberglass).
Miscellaneous Manufacturing (SICs combined).
Mobile Homes Manufacturing.
Nonclay Refractories.
Oil and Gas Production: Glycol Dehydrators.
Paint Application (no spray booths).
Pharmaceuticals Preparations and Manufacturing (SICs combined).
Plastics Materials and Resins Manufacturing.
Plastics Products Manufacturing.
Primary Copper Smelting.
Primary Metal Products Manufacturing (SICs combined).
Publicly Owned Treatment Works (POTWs).
Reconstituted Wood Products.
Sawmills and Planing Mills, general.
Secondary Copper Smelting.
Secondary Smelting and Refining of Nonferrous Metals.
Storage Batteries Manufacturing.
Textiles (SICs combined).
------------------------------------------------------------------------
F. How were the source categories selected for listing?
The language about selecting area source categories in section
112(c)(3) and section 112(k)(3)(b) differs somewhat. Section 112(c)(3)
requires us to list sufficient categories ``to ensure that area sources
representing 90 percent of the area source emissions of the 30 [listed]
hazardous air pollutants'' are subject to regulation under section 112.
That would seem to allow us to regulate either 90 percent of the
combined emissions of all of the 30 HAP or 90 percent of the emissions
of each of the 30 HAP. By contrast, section 112(k)(3)(B) requires us to
identify sufficient categories to ``assure that sources accounting for
90 percent or more of the aggregate emissions or each of the 30
identified hazardous air pollutants'' are subject to standards under
section 112(d). That language explicitly requires us to regulate 90
percent of the emissions of each of the 30 HAP. Consequently, we
selected the interpretation that allows us to read the two provisions
consistently. In other words, we assembled a draft list of area source
categories sufficient to cover 90 percent of the emissions of each of
the 30 HAP.
We ranked area source categories in the 1990 area source emission
inventory (described earlier) on a HAP-by-HAP basis. That is, area
source categories were ranked for each of the 30 urban HAP (30 separate
rankings) by mass of annual emissions (greatest tons per year to least
tons per year). For each HAP, we included emissions from those area
source categories which are already regulated or listed for regulation.
We then selected the greatest-emitting source categories until
emissions added up to 90 percent of the total emissions of that HAP.
All source categories selected in this process but not already listed
under section 112 are then to be listed for regulation.
It is important to note that for POM, we identified source
categories based on the 7-PAH surrogate. Because the available data for
the 7-PAH form are most amenable to risk analysis, we intend to apply
additional emissions standards only to the sources of emissions of this
form of POM.
[[Page 49250]]
However, we are seeking comment on the appropriateness of this
approach.
G. If my source category is already subject to MACT, will section
112(k) mean any changes to my requirements?
Additional requirements, if any, for new or existing standards may
follow after we conduct further assessments under section 112(f) of the
Act to determine residual risks after the implementation of MACT
standards set under section 112(d) and/or whether further actions under
section 112(k) and other Act authorities are needed to achieve risk
reduction goals. Because these elements of the program are not yet
developed, it is difficult to determine what, if any, changes will be
necessary. Section 112(k) requires that we ensure that 90 percent of
the aggregate emissions are subject to standards. If your area source
category is subject to a standard that has already been promulgated,
then that standard has been considered in the 90 percent and thus would
not require further listing under section 112(k). Where standards have
not yet been promulgated for your category, area sources may be made
subject to further requirements in order to assure the 90 percent
requirement is met.
H. Are changes to the list possible after the strategy is final?
It must be emphasized that, since the emissions inventory is likely
to change as new information becomes available from public comments, as
well as new data obtained in the regulatory development process, the
source categories selected for listing to meet the 90 percent emissions
requirement may also change. We expect to make revisions to this
regulatory listing based on new emissions information where it is more
accurate and effective to do so.
IV. Near-Term Actions To Implement the Strategy
This section discusses actions that we intend to take within the
next 2-3 years to address air toxics from all sources, including
decisions on the need for, and feasibility of, standards for motor
vehicle fuels and emissions, development of standards for area sources,
improvement in air quality and emissions databases, development of
analytical tools, and initiating collaboration with State and local
governments. It also provides summary information about what EPA and
State programs are currently in place to reduce risks from exposure to
HAP in urban areas.
A. How will EPA develop motor vehicle and/or motor vehicle fuel
standards?
As previously discussed, under section 202(l)(2) of the Act, we
will promulgate appropriate national regulations controlling HAP from
motor vehicles and their fuels. The standards will be based on the
updated analyses of the Motor Vehicle Related Air Toxic Study published
in 1993 under section 202(l)(1) of the Act, which analyzed the need
for, and feasibility of, controlling emissions of toxic air pollutants
which are associated with mobile sources. The section 202(l)(2)
regulations will reflect the greatest degree of emissions reductions
that can be achieved considering various factors including availability
and cost, and will at a minimum, address benzene and formaldehyde
emissions. We will examine mobile source contributions to urban air
toxics health risks and any new national mobile source regulations will
be established by 2000. We envision that work done in the early stages
of strategy implementation will serve to facilitate the important
comparisons of various emissions sources in the urban areas and allow
comparisons of control authorities to provide the best relative
reduction of risk to the urban public. Although the study of mobile
source emissions will be completed soon, and the rules may be among the
earliest activities of the strategy, we expect to continue our efforts
to ensure coordinated use of our authorities to address priority risks.
We expect to complete activities required by section 202(l)
according to the following dates, consistent with the consent decree:
1998: Complete the updated analysis of risks from mobile sources,
including addressing comments received from review of that study to
provide better estimations of mobile source emissions projected in the
future; estimate the exposure and predict risk to the public from motor
vehicle toxic emissions in 9 urban areas to better quantify the
magnitude of the health risks; and, assess available motor vehicle and/
or fuel technologies, and the impact or cost effectiveness of those
technologies to achieve the greatest reduction in public health risks
from air toxics under section 202(l).
1999: Issue a notice of proposed rulemaking for mobile source standards
2000: Issue final rulemaking on mobile source standards
B. How will EPA develop area source standards?
As discussed in section III, we must ensure that 90 percent of the
aggregate emissions of each of the area source urban HAP are subject to
regulation. Earlier, we presented the draft list of source categories
that must be included in addition to the existing MACT regulations to
achieve this requirement. We intend to ensure that the regulations that
result are both efficient and warranted for protection of public
health. In this notice, we are requesting comment on the following
approach to developing the regulations necessary to meet this
requirement.
We intend to focus MACT on those area sources where the impact is
greatest and where the technology applicable to major sources is also
appropriate to area sources. However, there are likely to be
circumstances where GACT might be more appropriate than MACT. In
establishing the basis for emission standards under section 112(d)(5),
Congress provided for GACT for area sources in lieu of MACT. That
provision does not define GACT, but only states that the Administrator
may elect to promulgate ``standards or requirements * * * which provide
for the use of generally available control technologies or management
practices by such sources to reduce emission of hazardous air
pollutants.'' For instance, there may be important differences in the
processes involved or the costs of control that might make it
infeasible for area sources to comply with MACT.
Although the primary focus of the specific requirements of section
112(c)(3) and 112(k) is to ensure that at least 90 percent of the
aggregate emissions of each of the 30 urban area source HAP are subject
to standards, we anticipate that area sources may be further addressed
in the strategy, as would major sources and motor vehicles, if we
determine that they continue to present significant public health risks
either on a national or local level once we have conducted analyses of
the estimated reduction of cancer and noncancer health risks.
We are seeking comments on the following schedule for developing
the urban area source standards:
1999: Finalize the Integrated Urban Air Toxics Strategy; Initiate the
development of additional area source standards
2002: Promulgate 50 percent of the area source standards
2004: Promulgate an additional 25 percent of the area source standards
2006: Promulgate final 25 percent of the area source standards
[[Page 49251]]
2008: Submit Report to Congress
2009: Require compliance with the urban air toxics standards
This schedule was established considering the facts that we are
currently engaged in significant efforts to develop standards for
stationary sources that were previously listed under section 112(c),
and that realistic schedule and resource constraints suggest that our
efforts to develop additional standards should be phased in over time.
C. What role do major stationary sources play in the strategy?
As previously discussed, section 112(k)(3)(b) requires that we
ensure that area sources accounting for 90 percent of the aggregate
emissions of the 30 112(k) HAP are subject to standards. Thus, major
sources are not affected by the requirements of this subsection.
However, in achieving required reductions in estimated cancer risk
and substantial reductions in health risks in general, section
112(k)(3)(C) permits us to consider reductions in public health risks
resulting from actions to reduce emissions from ``all stationary
sources and resulting from measures implemented by the Administrator or
by the States under this or other laws.'' We interpret the language of
this section to include reductions in major stationary source emissions
as well as area source emissions. Therefore, any reductions resulting
from MACT, the national ambient air quality standards, and other
programs that achieve reductions in HAP can be included in the
assessment of reductions in risks. In addition, in future stages of the
strategy, if it is determined that a source category or an individual
source is presenting a significant health risk, then it will be
addressed under the appropriate regulatory authority. For example, if a
source category is currently subject to MACT and it is found to pose a
significant remaining risk, then that risk could be addressed through
section 112(f) residual risk standards. Similarly, if a specific source
is contributing to a local risk problem, then the State or local
program may be more appropriate to address that risk. Finally, it is
important to note that while additional actions may be required to
address risks in the future, the baseline for evaluating what is needed
to achieve a 75 percent reduction in cancer incidence remains at the
1990 level.
D. How will EPA review and expand monitoring networks?
In order to better characterize the risks from HAP in urban areas,
it is important that we improve our ability to measure HAP in the urban
areas. To that end, we are working to improve our monitoring networks
for HAP in the urban areas over the next several years. The first step
in this effort is to improve our knowledge of where the State and local
agencies are currently monitoring HAP. We are currently conducting a
study to determine the coverage, comparability, and relevance of
existing monitoring networks. Further, recognizing competing resource
needs, we are encouraging the State and local agencies to tailor their
monitoring programs to address their most pressing air toxics issues
and local needs. However, we are requesting the State and local
agencies to work with us to develop a monitoring network distribution
that capitalizes on existing efforts and capabilities. We expect to add
17 new monitoring sites to the network in 1999. This will include one
new site in the major metropolitan areas of each of the ten EPA Regions
and an additional site in each of the seven areas with existing
Photochemical Air Monitoring System networks. In addition, we are
expecting to increase that number by up to 40 additional sites in 2000.
E. How will the consolidated emissions reporting rule fit in the
strategy?
In addition to expanded monitoring, we recognize the need for
improved emissions information to support air quality, modeling and
risk assessments. We are in the process of developing a consolidated
emissions reporting rule whose purpose is to simplify reporting, offer
options for data exchange, and unify reporting dates for various
categories of inventories. This action is expected to consolidate the
numerous emissions inventory reporting requirements found in various
parts of the Act and is being taken at the request of numerous State
and local agencies. Consolidation of reporting requirements will enable
these agencies to better explain to program managers and the public the
necessity for a consistent inventory program, increases the efficiency
of the emissions inventory program, and provides more consistent and
uniform data.
As discussed earlier, modeling is one of the primary tools that
will be used to estimate the exposure and risk from HAP. We will
continue to develop modeling tools and guidance for assessment of risks
on both the national and local scales.
F. What is the schedule for conducting risk assessments and assessing
progress toward the risk goals?
In addition to the emission standards called for by section
112(k)(3)(B), and to addressing the risk reduction goals described in
section 112(k)(3)(C), we expect to conduct assessments and make the
determination of whether additional risk assessment and risk management
activities are needed on an ongoing basis. However, the schedule for
conducting the risk assessments will be influenced by the Agency's
goal-setting and strategic planning processes and by the schedules set
forth in applicable provisions of section 112, including schedules for
the Reports to Congress required by section 112(k)(5). There are a
number of interim milestones that must be met in order to conduct these
assessments, particularly in the area of developing and refining the
modeling tools to conduct these assessments. They include:
1999:
(1) Initiate analyses of risks in urban areas; conduct assessment
of the emissions reductions from 1990 level due to current programs and
activities;
(2) expand monitoring network to 17 additional urban areas;
2000: Complete the national scale screening model (CEP2)
2001: Complete the local scale risk assessment model (TRIM);
Schedules for conducting more site-specific risk assessments will
be established based on the outcome of our efforts to develop, enhance,
and support State and local programs in the managing urban air toxics
risks.
G. Coordinate with State and local governments to develop or strengthen
risk-based air toxics programs.
In order to achieve our risk reduction goals, we will need to look
at ways to address public health risks not only on the national level,
but also on the local level because many of the factors that influence
risks, such as the types of sources, activity patterns, and
meteorology, vary from city to city. Much of what has been previously
discussed pertains to the tools and programs that can be employed on
the national level to address emissions and risks that occur uniformly
across the country. However, in order to achieve risk reductions at the
local level, it is important that the strategy provide for a strong
State or local role. We intend to work with the State and local air
program agencies to refine this aspect of the strategy. The following
is a discussion of some of the key elements
[[Page 49252]]
to developing the nature and scope of the State and local program.
One of our goals in the strategy will be to encourage and support
the State and local agencies in reducing public health risks (cancer
and noncancer--chronic and acute) in individual urban areas. Because
many of these risks are associated with specific local considerations,
such as clusters of sources, local meteorology, local fish and other
food consumption patterns, industrial make-up, and motor vehicle
density and activity in the specific urban area, we believe State and
local regulatory avenues are the most appropriate authorities to
address these risks. To that end, we envision a process that will
provide regulations, technical support and guidance, and/or other
support as necessary to State and local agencies to ensure that there
are substantial reductions in the public health risks in each urban
area. The process is expected to provide flexibility for local planning
and allow the development of city specific solutions to localized urban
risks. We envision our role in this program to include providing
guidance on important elements such as monitoring, emissions inventory
development, modeling and risk assessment, control techniques, and
enforcement provisions. As in the national elements of the program, we
envision a process that will include periodic review of the risks
associated with HAP emissions in the urban areas, and reductions
achieved to ensure that the program goals are met. In addition, because
the goal of the integrated strategy is to achieve public health risk
reductions, we believe that the State and local programs should be able
to address all emissions sources as appropriate to address the
aggregate risks in the area. For instance, if the largest contributor
to cumulative risk in an area is a cluster of MACT-controlled sources,
then the State may find that controls beyond MACT or those imposed by
residual risk are required. Likewise, if the risks are largely due to
mobile source emissions based on vehicle activity, then the State or
local Agency may consider transportation related measures to address
the risk.
1. What are the principles used in developing the State and local
program?
Based on our early discussions with a number of State and local
agencies, we developed and intend to employ the following principles in
developing provisions for use by State and local programs:
Provide a mechanism to encourage the development of State
and local requirements and programs;
Provide flexibility in implementing the national
standards;
Provide a balance between the need for flexibility for
States and local agencies with existing programs and the need to
provide a program for those States where Federal requirements are
necessary to enable addressing risks from the HAP.
We would like your comments on these principles, including the need
for other or different operating principles.
2. What are the key issues that must be addressed in developing the
State and local program?
Again, based on our discussions with State representatives, there
are a number of key issues that must be addressed which will determine
the nature and scope of the State/local programs. They include:
Should the program be mandatory?
If the program is required in some way, should the State
requirements be federally enforceable and, if so, by what mechanism?
Should the State and local program include elements to
address risk from all emission sectors (area source, major sources and
mobile sources)?
We would like your comments on these questions, including important
legal, technical, or other factual information in support of your
comments.
3. What might these programs include?
State and local representatives working with us developed a number
of preliminary ideas of how the program might work. We are requesting
comment on these ideas and on other ideas in developing the State and
local programs.
One suggested approach might be a control strategy approach where
we would set an urban areawide risk reduction target, considering risk
from all pathways, which the States could develop control strategies
and requirements for achieving those targets. These control strategies
would supplement the national MACT program and might include emissions
controls or other innovative strategies to address specific local
health risks from HAP. Another suggested approach might include States
that would be setting technology requirements for sources that
contribute to risks above a given level. This would be similar to
programs already in place in California, Maryland and other States.
Some State and local programs may be more effective if the strategy
provides for a purely voluntary program where we would provide Federal
guidance and information for reducing risks from urban HAP to the
State/local agencies and leave the program design to each individual
State or local program to develop and implement. Another approach would
be for us to set a HAP ambient concentration level and require/
recommend actions from the States where these levels were exceeded for
a specified duration and frequency. Another approach may be to use
combinations of these options. These options are not mutually exclusive
and other ideas might be developed or expanded upon in the future. We
are requesting input from you on the feasibility and desirability of
these options and on what the appropriate level of State and local
involvement should be. We expect to undertake some or all of the
following activities under section 112, depending on the outcome of
this process:
Development or strengthening of State and local programs;
Development of regulations necessary to provide authority
to implement the program (if appropriate);
Development of implementation guidance including
information on risk assessment, monitoring, modeling, emissions
inventory, potential control options; and,
Development of risk assessment tools for local planning.
While in the near term we intend to initiate discussions with the
States to further refine the program, most of these activities will be
longer-term activities. We expect to provide you with further
information and opportunities to comment as these elements are
developed or refined.
H. How does EPA intend to address special concerns about Environmental
Justice in the Urban Areas?
As discussed previously, we are particularly concerned about the
potential for disproportionate risk in low-income minority communities.
The Federal Government has not traditionally sought involvement from
these communities in environmental program development and have voiced
significant concerns about the difficulties and disadvantages they face
when attempting to participate in decisions affecting their
communities. We believe that the integrated urban air toxics strategy
should evaluate the potential links between toxic exposure and health
effects in disproportionately exposed populations, and should address
any significant resulting risks. Concurrently, we will consider
economic development and employment-related issues to ensure
sustainable economic development while addressing unacceptable levels
of
[[Page 49253]]
risk. In order to facilitate the development of a strategy which will
be responsive to these environmental justice concerns, we are actively
encouraging community groups not only to comment on the strategy, but
also to work actively with us in developing a program that can address
their concerns.
I. What EPA or State programs are currently in place to address the
risk posed by these HAP?
There are a number of activities that will take place prior to
risk-based goal setting envisioned in the national air toxics program
that will achieve significant early emissions reductions. They include
actions to reduce emissions from mobile, major, and areas sources, both
as a direct result of the Act requirements for control of air toxics
described above, and requirements under programs (e.g., the national
ambient air quality standards) which achieve significant coincidental
air toxics benefits. As discussed above, the strategy called for under
section 112(k)(3) is to achieve reductions in public health risks
through emissions control ``measures implemented by the Administrator
or by the States under this or other laws.'' The following presents a
summary of Federal and State and local programs that are currently
achieving HAP emissions reductions. This information will be considered
in our assessments of reductions in public health risks which have been
achieved as we evaluate the need for additional regulations.
1. Federal Regulatory Authorities
Clean Air Act, Section 112 Authorities: Under section 112 of the
1990 Amendments to the Act, there are many provisions, authorities, and
programs that are reducing, and will continue to reduce, HAP emissions,
exposures and health risks. Several of the major programs are discussed
below. Further information is available from the ``Second Report to
Congress on the Status of the Hazardous Air Pollutant Program under the
Clean Air Act,'' EPA-453/R-96-015, October 1997.
Section 112 established a procedure for developing and requiring
performance-based emission standards for sources of HAP following a
detailed 10 year schedule for action. These standards of control
technology, required by section 112(d), are known as MACT standards and
GACT standards. We are required to list categories and subcategories of
major and area sources of HAP and then, according to a 10 year
schedule, establish control requirements to assure that all major
sources of HAP achieve the level of control already being achieved by
the best performing sources in each category (i.e., MACT standards),
and ensure that listed categories of area sources are subject to MACT
or, alternatively, to GACT standards, which are controls that are
generally available across the industry. As required by section
112(c)(1), we published an initial list of source categories in 1992
(57 FR 31576). Revisions made thus far have included adding and
deleting source categories, combining categories for purposes of
efficiency, and making other relatively minor changes and corrections.
The list currently contains 175 categories, of which 167 are for major
sources and eight for area sources (61 FR 28197). Note that some
categories include both major and area sources. The schedule, initially
published in 1993 (58 FR 63941), specifies source categories for which
standards are to be promulgated within 2, 4, 7 and 10 years following
November 15, 1990, such that standards are promulgated for 25 percent
of the listed categories in the first 4 years (i.e., by November 15,
1994), an additional 25 percent by November 15, 1997, and the remaining
50 percent by November 15, 2000.
We have thus far promulgated standards for all 47 source categories
listed in the 2 and 4 year groups, which is approximately 25 percent of
the 175 listed source categories. We estimate that these major and area
source regulations will reduce air toxics emissions by approximately
980,000 tons per year. Additional MACT and/or GACT emissions standards
for the remaining listed source categories are scheduled to be
promulgated by November 15, 2000. These standards are expected to
obtain substantial additional reductions in air toxics over the next
several years and will decrease exposures and risks due to air toxics
in urban areas.
Under the Residual Risk Program established by section 112(f), we
will be assessing public exposures to HAP following MACT standard
promulgation to assess the remaining public health and environmental
effects of HAP and issue standards to provide an ample margin of safety
to protect public health, if necessary. The residual risk provisions
apply to all MACT standards and, therefore, focus primarily on major
sources. We have the discretion to apply residual risk provisions to
MACT standards that affect area sources as well.
Under section 112(r), we published a final risk management program
rule for the Prevention of Accidental Releases on June 20, 1996 (61 FR
31668). Along with the final rule, we published guidance to assist the
owner or operator of processes covered by the risk management program
rule in the analysis of offsite consequences of accidental releases of
substances regulated under section 112(r) of the Act. The list of
regulated substances with threshold quantities was published on January
31, 1994 (59 FR 4478). Of the 140 chemicals (77 acutely toxic
substances and 63 flammable gases) regulated under section 112(r), 18
are HAP under section 112(b) and eight are on the draft list of urban
HAP presented in this notice for public comment. Section 112(r) also
requires the source to assess each process to ensure they are safe and
will not accidently release HAP. By preventing accidental releases, the
section 112(r) rule will help reduce or prevent emissions of these HAP
in the future.
Requirements associated with the Act in section 112(g) and
112(i)(5) are also expected to yield reductions in emissions of HAP in
urban areas. The Construction and Reconstruction Rule required by
section 112(g) of the Act was issued in final form on December 27, 1996
(61 FR 68384). The rule requires, as of July 1, 1998, MACT controls for
any new or reconstructed major source of HAP and major HAP-emitting
production units at existing facilities. Section 112(i)(5), early
reductions rules, provide incentives for sources of HAP to reduce
emissions by 90 percent (95 percent for particulates) from 1990 levels
prior to the proposal of MACT for that source category. Eligible
sources may be granted a 6-year extension from compliance with the
later promulgated MACT, during which time they must meet alternative
emissions limitations which reflect the early reductions. Approximately
27 permit applications have been received, representing HAP reductions
of over 6,800 tpy. Approximately six permits have been issued to date.
Other CAA authorities: In addition to authorities under section
112, there are several other Act sections, the implementation of which
may contribute or has already contributed to reductions in air toxics
in urban areas. For example, state implementation plans developed to
attain compliance with the national ambient air quality standards (set
under section 109) are expected to provide incidental, but potentially
significant, reductions in HAP in addition to their intended result of
reducing levels of criteria pollutants (e.g., particulate matter,
ozone, etc).
The Act's mandated acid rain program may also provide HAP
reductions in urban areas in addition to the intended
[[Page 49254]]
result of sulfur dioxide and nitrogen oxides emissions reductions.
Section 202(l) is a critical part of the national air toxics
program and will be very important to the success of the Urban Air
Toxics Strategy because efforts to respond to section 202(l) will
address exposure to HAP from motor vehicles and motor vehicle fuels.
However, section 202(l) is just one example of the Act's authorities
regarding mobile sources. Other provisions which may affect reductions
in urban air toxics from mobile sources include sections 211 (fuel
requirements), 213 (emission standards for nonroad engines and
vehicles), and 219 (urban bus standards).
Performance standard setting for solid waste incineration units and
landfills under section 129 of the Act, which has been completed for
two of the four categories (municipal, medical, industrial and
commercial, and other categories of incinerators), is estimated to
result in substantial reductions in total HAP emissions (>50,000 tons/
yr), much of which may be in urban areas. Under section 129, specific
numerical emission limitations are required for various pollutants
including lead, cadmium, mercury, and dioxins/furans, all of which are
included on the draft list of urban HAP. Like the MACT standards,
residual risk applies to section 129 standards and thus potential
additional reductions may be possible in these areas.
Title VI of the Act directs us to protect the stratospheric ozone
layer through the reduction or elimination of certain chemicals. These
ozone-depleting substances include three HAP (carbon tetrachloride,
methly chloroform, and methly bromide), one of which, carbon
tetrachloride, is included in the draft list of urban HAP in addition
to the better known chlorofluorocarbons (CFC). We are implementing
title VI through a number of regulatory and voluntary programs which
have been successful in reducing production, use, and emissions of many
CFC and other ozone depleting chemicals. Production and import of
carbon tetrachloride and methyl chloroform were phased out as of
January 1, 1996 and the third is expected to be phased out by 2001.
Related regulations restrict uses to minimize the potential for these
chemicals to get into the atmosphere.
Other Federal laws: There are a number of other authorities, laws,
rules, and programs that will also help reduce emissions of HAP and
consequent exposures and risks. Some of these are discussed below. We
are currently evaluating the appropriateness of these statutes for
controlling emissions of HAP as described under section 112(k)(3) and
intend to take further actions under these statutes as appropriate.
Under the Toxic Substances Control Act (TSCA), chemicals produced
or imported into the United States are evaluated as to toxicity to
human health and the environment. To prevent adverse consequences of
the many chemicals developed each year, TSCA requires that any chemical
that will reach the consumer marketplace be tested for possible toxic
effects prior to commercial manufacture. Any existing chemical that is
determined to pose health and environmental hazards is tracked and
reported under TSCA. Procedures also are authorized for corrective
action under TSCA in cases of cleanup of toxic materials contamination.
The TSCA is a complementary authority to the Act and has contributed to
decreased emissions of several HAP. For example, concern over the
toxicity and persistence in the environment of polychlorinated biphenyl
compounds (PCB) led Congress to include in TSCA (see section 6(e) of
TSCA), prohibitions on the manufacture, processing, and distribution in
commerce of PCB. In 1990, TSCA authority was relied upon to eliminate
chromium use in and emissions from comfort cooling towers, i.e.,
industrial process cooling towers used exclusively for cooling,
heating, ventilation, and air conditioning systems.
There are several provisions of the Resource Conservation and
Recovery Act (RCRA) and its amendments which may yield reductions of
urban air toxics. One impact evidenced in the 1990's is increased
recycling and recovery of hazardous waste, including solvents which
through volatilization contribute to HAP emissions. The RCRA's section
3004(n) has been the basis of a three-phased regulatory program to
control air emissions from hazardous waste treatment, storage and
disposal facilities. The third phase will address any risks remaining
after implementation of the control regulations issued in 1990 and
1994, which were estimated to reduce HAP emissions by more than one
million tons per year. Any resulting emissions and risk reductions can
be considered in assessing progress in achieving the 75 percent
reduction in cancer incidence from the 1990 base year.
Under the Comprehensive Environmental Response, Compensation and
Liability Act, commonly known as Superfund, the clean up of abandoned
hazardous waste sites may also reduce emissions of HAP. Where
significant health risks from chemical releases to the air have been
identified at Superfund sites in urban areas, clean-up will reduce
risks from urban air toxics.
Under the Clean Water Act (CWA), States are required to adopt water
quality standards for those section 304(a) priority pollutants which
may be interfering with their water bodies' designated uses. In
response to the CWA, we identified 126 priority pollutants for action.
The CWA authorities provide for the regulation of discharges of these
pollutants in order to meet applicable water quality standards. Among
these pollutants, many are on the draft list of urban HAP. We are
exploring how the CWA and the Act tools can be used together to reduce
HAP.
The Federal Insecticide, Fungicide and Rodenticide Act (FIFRA)
provides Federal control of pesticide distribution, sale, and use.
Several HAP have been used as pesticides. An EPA registration is
required of all pesticides sold in the United States and is intended to
ensure that pesticide use, when in accordance with label specifications
regarding acceptable uses, does not cause unreasonable harm to people
or the environment. It is a violation of FIFRA to use a pesticide in a
manner inconsistent with its label. Registered pesticides classified as
``restricted use'' may only be used by registered applicators who have
passed a certification exam. This restricted use requirement minimizes
the number of persons having access to certain pesticides. The FIFRA
regulations may also reduce emissions and exposures by banning
(canceling or denying registration) or severely restricting pesticide
use. Seven individual HAP and members of three HAP compound groups have
been banned or severely restricted in their use as pesticides.
Two other Federal laws, the Emergency Planning and Community Right-
To-Know Act (EPCRA) of 1986 and the Pollution Prevention Act (PPA) of
1990, while not directly regulating air emissions of HAP, may influence
decisions regarding chemical usage and storage and yield significant
reductions in air toxics risks in urban areas. The goal of EPCRA is to
reduce risks to communities through informing communities and citizens
of chemical hazards in their areas. Sections 311 and 312 of EPCRA
require certain facilities to report the locations and quantities of
chemicals stored at their facilities to State and local governments.
This information is used by State and local agencies in preparing for
and responding to chemical spills and similar emergencies.
[[Page 49255]]
Through EPCRA, Congress mandated that a Toxics Release Inventory be
made public. The TRI provides citizens with accurate information about
potentially hazardous chemicals stored, manufactured and used in their
community so that they have more power to hold companies accountable
and make informed decisions about how toxic chemicals are to be
managed. Section 313 of EPCRA specifically requires certain
manufacturers and all Federal facilities to report to EPA and State
governments, all releases of any or more than 600 designated toxic
chemicals to the environment (including most of the 188 HAP). Each
year, more than 20,000 manufacturing facilities and 200 Federal
facilities submit information to us on the releases of chemicals to the
environment. We compile these data in an on-line, publicly accessible
national database, which is a significant source of information
regarding HAP emissions. Reporting requirements for TRI became more
comprehensive in 1991, highlighting the importance of pollution
prevention. It is expected, and has been observed for some chemicals,
that this public accounting for use and disposal of toxic chemicals may
lead to reductions in their environmental release.
The passage of the Pollution Prevention Act (PPA) established an
environmental hierarchy that establishes pollution prevention (P2) as
the first choice among waste management practices and was adopted as
national policy. Traditionally, much environmental protection has
involved controlling, treating or cleaning up pollution which, in many
cases, we continue to create. Pollution prevention, which eliminates or
minimizes pollution at the source, is most effective in reducing health
and environmental risks because it: (1) Eliminates any pollutant
associated risks; (2) avoids shifts of pollutants from one medium (air,
water or land) to another, which can result from certain waste
treatments; and (3) protects natural resources for future generations
by cutting wastes and conserving resources. For waste that cannot be
avoided at the source, recycling is considered the next best option. A
waste generator should turn to treatment or disposal only after source
reduction and recycling have been considered. Pollution prevention
strategies include redesigning products, changing processes,
substituting raw materials for less toxic substances, increasing
efficiency in the use of raw materials, energy, water, land and other
techniques. This is done in several ways, such as using voluntary
pollution reduction programs, engaging in partnerships, providing
technical assistance, funding demonstration projects and incorporating
cost-effective pollution prevention alternatives into regulations and
other initiatives.
In addition, in 1994, we developed the Waste Minimization National
Plan, a voluntary, long-term effort to reduce the quantity and toxicity
of hazardous waste through waste minimization. The plan calls for a 50
percent reduction in the presence of the most persistent,
bioaccumulative and toxic (PBT) chemicals in hazardous waste by 2005.
To assist in implementing this plan, we are developing a software tool
to prioritize PBT chemicals to focus national waste minimization
efforts and methods to track progress in reducing the presence of PBT
chemicals in waste and the volume of hazardous waste streams containing
PBT chemicals.
The starting point for selecting chemicals for the national waste
minimization list is EPA's Waste Minimization Prioritization Tool, a
software program which provides a screening-level assessment of
potential chronic risks chemicals pose to human health and the
environment, based on their persistence, bioaccumulative potential, and
human and ecological toxicity. This software program contains full or
partial PBT data for approximately 4200 chemicals. The draft Waste
Minimization Prioritization Tool was released for public comment in
June 1997 (62 FR 33868, June 23, 1997) and a revised version is
expected to be released in early 1999.
In addition to PBT data from the Waste Minimization Prioritization
Tool, we are considering a number of other factors in selecting
chemicals for the national waste minimization list, including
information about the quantity of chemicals in hazardous waste, the
number of facilities generating or handling the chemicals in waste, the
extent to which the chemicals have been found in the environment, and
the significance of the chemicals to the RCRA program, other Agency
programs, and States.
We are requesting comment and specific information on other Federal
programs, such as the Oil Pollution Act of 1990, that should be
considered for potential reductions in risk from HAP.
2. Summary of State and Local requirements
The Act requires that the strategy reduce cancer incidence by
actions under ``this or other laws * * * or by the States.'' By
including this language, Congress acknowledged that there are many
State programs achieving HAP emissions reductions and therefore,
reducing the chance for exposure and health risks including cancer. For
example, before the Clean Air Act was amended in 1990, many State and
local governments developed their own programs for the control of air
toxics from stationary sources. Some of these State and local
government programs have now been in place for many years and, for some
of the source categories regulated by Federal emissions standards under
section 112 of the Act, the State or local government programs have
likely reduced air toxics emissions and may have succeeded in reducing
air toxics emissions to levels at or below those required by the
Federal standards. It is clear that Congress intended State and local
governments to be important partners in carrying out the mandates of
the Federal air toxics program, and the strategy provides a mechanism
to recognize the reductions made by them.
Because of the varied nature of the emissions sources, legislative
structures, and other factors, the State and local government programs
address air toxics in a number of ways. For example, some States and
local programs have enacted technology standards for source categories
that require controls for specific HAP, much like the MACT program.
Other State or local government programs apply a risk standard to
sources that prohibit emissions beyond a certain level of risk. Other
States use an ambient air standard for air toxics that is based on
threshold or exposure levels. Still others may rely on reductions
achieved through volatile organic compounds, particulate matter, or
lead regulations developed under section 110 or subpart D of the Act
that control emissions of HAP to meet national ambient air quality
standards. Regardless of the approaches used to address air toxics,
State and local governments have accomplished and continue to
accomplish reductions of HAP. As we proceed to implement the strategy,
we will work with the States to better characterize these reductions in
emissions and the resulting reductions of public health risks,
including risk of cancer.
V. Longer-Term Activities
This section discusses longer-term activities we expect to take to
address risks from air toxics in urban areas, including how we intend
to initiate assessments of urban risk, residual risk standards,
additional stationary source standards, and possible State program
actions. It further discusses our research strategy to better
characterize risk and to
[[Page 49256]]
assess progress toward the risk reduction goals of the strategy.
A. How will EPA assess improvements in health risks?
1. How will EPA assess the reduction in cancer risk?
As discussed previously, in the integrated urban air toxics
strategy, we expect to utilize qualitative assessments of cancer
initially by determining the emissions reductions achieved since 1990
and using these emission reductions as rough surrogates for risk. Over
time, we intend to develop more quantitative estimates of risk or
estimated cancer incidence associated with toxic air pollutants to
measure progress toward the Act's goal of achieving a 75 percent
reduction in cancer incidence from 1990 levels. This effort is still
under development, and the final strategy will include more detailed
text describing the cancer risk-reduction estimation methodology and a
timeframe for carrying out the analysis.
2. How will EPA assess the reduction in noncancer risks?
As discussed before, Congress also expressed concern in section
112(k) about the noncancer health risks posed by HAP. While Congress
did not provide a quantitative goal for noncancer risks, we believe
that these risks are important to address. Several issues, however,
complicate our ability to assess reductions in noncancer risks. A
complication particularly relevant to urban air is our incomplete
knowledge about the effect of multiple pollutants. At a more
fundamental level, however, while we and other agencies have developed
estimates of lifetime excess cancer risks associated with air exposures
to many HAP, we do not have comparable quantitative ``risk per
exposure'' measures for assessing health risks other than cancer. The
reason for this is the assumption that there are thresholds associated
with most noncancer health effects such that exposures below the
threshold are considered unlikely to be harmful. Consistent with this
reasoning, we and other entities charged with protection of public
health, have identified ambient air levels for many air pollutants
which are unlikely to pose health risks for persons (including
sensitive sub-populations) who are exposed to that level over their
lifetime. These levels do not, however, provide information on the
exposure levels at which health effects are expected (i.e., the
threshold). Moreover, these cancer and noncancer concern thresholds do
not account for possible additive (i.e., synergistic) or antagonistic
effects when there are mixtures of HAP, as in urban areas. The issues
raised here necessitate the development of a noncancer risk reduction
assessment methodology or selection from among existing methods which
differs from that which we intend to follow for assessment of cancer
risk reduction.
We intend to address these issues as we proceed to set goals for
noncancer risk reductions and provide a description of assessment
methodologies, evaluating progress against the goal and identifying
appropriate additional risk reduction actions. The final strategy will
document our progress in addressing these activities.
3. How will EPA use modeling to assess risks?
In general, two types of models are important to our ability to
assess risk to the public from exposure to HAP: (1) transport,
diffusion and/or dispersion models simulate the release and transport
of pollutants, estimating concentrations at different points in time
and space; and (2) Exposure models simulate human activity patterns to
estimate the extent to which people may be exposed to pollutants and,
therefore, experience some level of risk. Air quality simulation models
have a long history of use in providing pollutant concentrations for
use in specifying emission limits and assessing control strategies to
attain ambient air quality standards. The Guideline on Air Quality
Models was established to promote consistency in the use of models
within the air management process.
Our use of exposure models to estimate risks to the public from HAP
in a meaningful and reliable manner has been more limited. As part of
the integrated urban air toxics strategy, we are conducting a pilot
modeling study for certain cities to better understand the potential
public exposure to HAP. The use of existing modeling tools to estimate
exposure potential for the urban air toxics strategy poses special
challenges due to the large geographical scale in urban areas relative
to the types of exposures which can produce adverse health effects, the
large number and variety of sources to be modeled, the variety of
pollutants to be considered, and variations in the exposure regimes of
significance for estimating the likelihood of effects. For that
purpose, we are developing a document describing suggested methodology
for using air dispersion models in urban areas. The document
illustrates the type of issues encountered when modeling two example
urban areas and provides suggestions for State and local agencies to
follow when modeling air toxics in urban areas.
4. How will EPA use ambient monitoring to assess risk?
Ambient air quality data can provide valuable input into the
assessment of the cancer and noncancer risks from air toxics in urban
areas. First, ambient air quality data provide a measure against which
any modeling of atmospheric HAP concentrations can be compared for
evaluation or verification purposes. Ambient air quality data can also
be used to evaluate differences in HAP concentrations from one urban
area to another to determine geographic patterns and/or characteristic
profiles based on demographic, economic or other attributes of these
areas. Finally, trends analyses of ambient air quality data on toxics
can provide a measure of the effectiveness of regulatory programs over
time. In addition to chronic exposure data, short term exposure data
may be important in various noncancer assessments. It is important to
recognize that exposure data can include more than ambient air
concentrations, and that microenvironmental exposure data can be
important to achieve a distribution of the population exposures.
As the goals for the program are established and the early
activities are carried out, we will conduct appropriate analyses to
determine the success of the program against the goals. If, in the
assessment of risk reduction, we conclude that the reduction goals
(e.g., 75 percent reduction in cancer risk) are not yet met, we expect
to identify and implement additional activities necessary to meet those
goals. These activities might include regulations to reduce stationary
or mobile source emissions or implementation of specific State
programs. Some examples of such actions are described below:
a. Residual risk standards. Under section 112(f) of the Act, we are
required to assess the risks remaining after the MACT standards are
implemented. For some source categories, more stringent standards to
achieve additional risks reductions from those standards might be
necessary. We intend to count any resulting risks reductions in the
urban areas toward the 75 percent reduction in cancer risks. However,
it is important to remember that residual risk only applies to source
categories for which there are MACT standards. Because MACT standard
development has focused on major sources, the residual risk program
will
[[Page 49257]]
primarily address risk from major sources.
b. Additional stationary source standards. We will develop section
112(d) standards (MACT/GACT) for the source categories listed
previously to address the requirements of section 112(k)(3)(B).
Emissions reductions from these standards are expected to reduce HAP-
associated health risks, thus providing early progress in achieving the
risk goals required under section 112(k)(3)(C). However, it is
important to recognize that in order to achieve the risk goals, we may
need to go beyond source-category-by-source-category approaches because
of concerns about cumulative risk from numerous sources. We believe
that individual 112(d) standards may not adequately address those risks
without further actions.
c. State program actions. As discussed earlier, in order to achieve
our risk reduction goals at the local level, it is important that the
strategy provide for a strong State or local role. We believe that this
will require significant ongoing efforts to develop and implement the
program in the urban areas. We will work with the State and local air
program agencies to refine this aspect of the strategy and we expect to
provide further opportunities for comment on it.
To address these issues and develop the necessary additional
technical, policy and/or regulatory support, we expect to carry out
additional efforts under the following schedule.
1999: Convene a State/local work group to better define the State and
local program structure
2000: Complete work on program development
2001: Development of any regulations necessary to provide authority to
implement the program (if appropriate)
2002: Develop implementation guidance concerning: risk assessment,
monitoring, modeling, emissions inventory, potential control options
2006: Assess progress toward goals, including the Integrated Urban Air
Toxics Strategy Report to Congress.
d. How will EPA address information and data gaps?
Significant research and data needs must be addressed in order to
achieve the goals of the strategy. Estimates of the reduction of cancer
incidence and of other significant public health effects related to
exposure to HAP targeted in this strategy will require:
Additional knowledge of both cancer and noncancer health
effects of these pollutants. This will include determinations of
specific toxicities determined from animal and human studies as well as
the development of models to extrapolate across species, across time
and across routes of exposure with a special emphasis on the effects of
HAP in children.
Improved monitoring data for ambient levels of HAP to
improve spatial characterization of exposure potential and act as a
measure against which modeling concentrations can be compared for
evaluation or verification purposes.
Improved data to better understand the potential for
disproportionate impacts on minority and low income communities.
Improved emissions models to estimate and assess HAP
emissions in a representative number of cities, and to extrapolate
results to other locations, together with atmospheric transport and
fate models.
Improved exposure models that include multiscale air
dispersion models (neighborhood, urban, and regional) and simulated
microenvironments of exposure, to estimate inhalation exposures to
urban HAP and their potential transformation products.
Improved modeling and monitoring to assess noninhalation
exposures to contaminated foods, such as fish, vegetables and beef,
resulting from deposition of urban HAP.
Measurement methods for many HAP for which none are
currently available.
Reference values such as inhalation reference
concentrations, acute reference exposure values, and cancer unit risk
factors for those among the HAP for which such values have not been
developed to perform quantitative risk assessments that EPA plans to
use as part of this strategy.6
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\6\ The use of These values is an essential part of EPA's
current practices in conducting risk assessment. For further
information about how the we conduct risk assessments please refer
to the draft Residual Risk Report to Congress on the EPA website
(www.epa.gov/ttn/oarpg/t3/report/rrisk.pdf) and the National
Research Council (NRC). 1994 Science and Judgment in Risk
Assessment. National Academy Press, Washington, D.C. and the
Commission on Risk Assessment and Risk Management (CRARM). 1997.
Risk Assessment and Risk Management in Regulatory Decision making.
Final Report, Volume 2.
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Statistical methods for quantifying and reducing
uncertainty in risk assessments.
Cost-effective control technologies for all HAP and more
effective controls developed for those pollutants predicted to have
residual risk using currently available controls.
e. What is the schedule for addressing the research needs?
Research needed to improve the quantitative risk assessment and
risk management of pollutants addressed in the urban air toxics
strategy will be identified in a separate research needs chapter of the
Integrated Urban Air Toxics Strategy Report to Congress that will be
provided to the public in June of 1999. Our current and near-term
planned research activities will also be described.
VI. How will EPA communicate with the public on progress in meeting
the strategy's goals?
The Act requires us to report to Congress at intervals not later
than 8 and 12 years after the date of enactment of the CAA Amendments
of 1990. We expect to provide the first Report to Congress when we
issue the final strategy on June 18, 1999. We anticipate updating the
public periodically on the status of the activities to implement the
work plan, as well as the status of the activities to reduce risks in
urban areas. However, we also expect to report to the public annually
on the air quality and emissions trends for air toxics in urban and
other areas in our annual Air Quality and Emissions Trends Reports.
Many of the activities identified in the strategy will require
further public notice and comment, and we will be providing further
opportunities as they are developed. The public will also be able to
measure the progress of the strategy by tracking these milestones.
VII. Regulatory Requirements
A. General
Today's notice is not a rule and does not impose regulatory
requirements or costs on any sources, including small businesses.
Therefore, the EPA has not prepared an economic impact analysis
pursuant to section 317 of the Act, nor a regulatory flexibility
analysis pursuant to the Regulatory Flexibility Act (Pub. L. 96-354,
September 19, 1980), nor a budgetary impact statement pursuant to the
Unfunded Mandates Act of 1995. Also, this notice does not contain any
information collection requirements and, therefore, is not subject to
the Paperwork Reduction Act, 44 U.S.C. 3501 et seq.
B. Executive Order 12866 and Office of Management and Budget (OMB)
Review
Under Executive Order 12866 (58 FR 51735, October 4, 1993), the
Agency must determine whether a regulatory action is ``significant''
and therefore subject to OMB review and the requirements of the
Executive Order.
[[Page 49258]]
The Order defines ``significant'' regulatory action as one that is
likely to lead to a rule that may either: (1) have an annual effect on
this economy of $100 million or more, or adversely and materially
affect a sector of the economy, productivity, competition, jobs, the
environment, public health or safety, or State, local or tribal
governments or communities; (2) create a serious inconsistency or
otherwise interfere with an action taken or planned by another Agency;
(3) materially alter the budgetary impact of entitlement, grants, user
fees, or loan programs or the rights and obligations of recipients
thereof; or (4) raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
Pursuant to the terms of Executive Order 12866, this is not a
``significant regulatory action'' within the meaning of the Executive
Order. This notice was submitted to OMB for review. Any written
comments from OMB and written EPA responses are available in the
docket.
C. Regulatory Flexibility Act of 1996
Today's action is not a rule that requires the publication of a
general notice of proposed rulemaking. Thus, it is not subject to the
Regulatory Flexibility Act of 1980, as amended by the Small Business
Regulatory Enforcement Fairness Act of 1996. In any case, as mentioned
above, this notice does not impose any regulatory requirements.
Instead, it merely provides a draft list of source categories and a
draft schedule of specific actions. Consequently, this notice will not
have any economic impact on small entities.
D. Executive Order 13084: Consultation and Coordination With Indian
Tribal Governments
Under Executive Order 13084, EPA may not issue a regulation that is
not required by statute, that significantly or uniquely affects the
communities of Indian tribal governments, and that imposes substantial
direct compliance costs on those communities, unless the Federal
government provides the funds necessary to pay the direct compliance
costs incurred by the tribal governments. If the mandate is unfunded,
EPA must provide to the Office of Management and Budget, in a
separately identified section of the preamble to the rule, a
description of the extent of EPA's prior consultation with
representatives of affected tribal governments, a summary of the nature
of their concerns, and a statement supporting the need to issue the
regulation. In addition, Executive Order 13084 requires EPA to develop
an effective process permitting elected and other representatives of
Indian tribal governments ``to provide meaningful and timely input in
the development of regulatory policies on matters that significantly or
uniquely affect their communities.'' Today's rule does not
significantly or uniquely affect the communities of Indian tribal
governments because it is not a rule and does not impose regulatory
requirements or costs on any sources. Accordingly, the requirements of
section 3(b) of Executive Order 13084 do not apply to this rule.
E. Applicability of the E.O. 13045: Children's Health Protection
(62 FR 19885, April 23, 1997) applies to any rule that: (1) Is
determined to be ``economically significant'' as defined under E.O.
12866, and (2) concerns an environmental health or safety risk that EPA
has reason to believe may have a disproportionate effect on children.
If the regulatory action meets both criteria, the Agency must evaluate
the environmental health or safety effects of the planned rule on
children, and explain why the planned regulation is preferable to other
potentially effective and reasonably feasible alternatives considered
by the Agency.
This draft strategy is not subject to the Executive Order because
it is not a rule, it is not economically significant as defined in E.O.
12866, and the Agency does not, at this time, have reason to believe
the environmental health or safety risks addressed by this action
present a disproportionate risk to children.
The public is invited to submit or identify peer-reviewed studies
and data, of which the Agency may not be aware, that assessed results
of early life exposure to any of the HAP of concern discussed in this
notice.
F. National Technology Transfer and Advancement Act
Section 12 of the National Technology Transfer and Advancement Act
of 1995 (NTTAA) requires Federal agencies to evaluate existing
technical standards when developing new regulations. To comply with
NTTAA, the EPA must consider and use ``voluntary consensus standards''
(VCS) if available and applicable when developing programs and policies
unless doing so would be inconsistent with applicable law or otherwise
impractical.
The EPA believes that VCS are inapplicable to this draft strategy.
The section 112(k)(3) strategy and section 112(c)(3) listing are not
regulatory actions that require the public to perform activities
conducive to the use of VCS. Instead, the strategy and listing are
actions performed by the Agency in anticipation of potential future
standard-setting, research, and other related activities. The EPA may,
however, find that VCS are available, applicable, and practical for
regulations that are promulgated in the future pursuant to the strategy
and listing. In any case, the Agency requests comments on whether any
VCS exist that could be considered for inclusion in this strategy and
listing.
Dated: August 31, 1998.
Robert Perciasepe,
Assistant Administrator for Air and Radiation.
[FR Doc. 98-24335 Filed 9-11-98; 8:45 am]
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