Draft Integrated Urban Air Toxics Strategy To Comply With Section 112(k), 112(c)(3) and section 202(l) of the Clean Air Act

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.L[email protected].

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.

---------------------------------------------------------------------------

\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.

---------------------------------------------------------------------------

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.

---------------------------------------------------------------------------

\2\ Section 112(b) of the Act lists 189 hazardous air pollutants

(HAP). One of the HAP, caprolactam, was subsequently delisted.

---------------------------------------------------------------------------

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

[[Page 49243]]

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.

---------------------------------------------------------------------------

\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.

---------------------------------------------------------------------------

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.

[[Page 49244]]

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.

---------------------------------------------------------------------------

\4\ These HAP include: benzene, carbon tetrachloride,

chloroform, ethylene dibromide, ethylene dichloride, formaldehyde,

methyl chloride, and bis(2-ethylhexyl)phthalate.

---------------------------------------------------------------------------

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

---------------------------------------------------------------------------

\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.

---------------------------------------------------------------------------

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]

BILLING CODE 6560-50-P