Urban Ozone and the Clean Air Act:

Problems and Proposals for Change

April 1988

NTIS order #PB88-205414
URBAN OZONE AND THE CLEAN AIR ACT:

Problems and Proposals for Change

A Staff Paper

from OTA’s Assessment of

New Clean Air Act Issues

Project Staff

Robert M. Friedman, Project Director

Jana Milford, OTA Fellow

Richard Rapoport, Analyst

Nancy Szabo, Analyst

Kathryn Harrison, Analyst

Sally Van Aller, Administrative Secretary

Robert W. Niblock, Program Manager

Oceans and Environment Program

John Andelin, Assistant Director

Science, Information and Natural Resources Division

April 1988

Oceans and Environment Program

Office of Technology Assessment

United States Congress

Washington, D.C. 20510-8025

The views expressed in this Staff Paper do not

necessarily represent those of the Technology

Assessment Board, the Technology Assessment

Advisory Council, or their individual members.
PREFACE

Over the past several months, Congress has once again turned its attention to the

widespread failure of U.S. cities to attain the health-based air quality standard for ozone. The

last major set of changes to the Clean Air Act, the Clean Air Act Amendments of 1977, set

December 1987 as the latest deadline for attaining the standard. Last December, as many urban

areas faced the prospect of sanctions, Congress extended the deadline through August, allowing

more time to consider several proposals addressing the ozone nonattainment problem. This OTA

staff paper has been prepared to assist the ongoing Congressional consideration of these

proposals.

S. 1894, a comprehensive set of amendments to the Clean Air Act, has been reported by

the Senate Committee on Environment and Public Works and awaits consideration by the full

Senate. H.R. 3054, introduced by Congressman Waxman and 39 cosponsors, is currently being

discussed within the Subcommittee on Health and the Environment of the House Committee on

Energy and Commerce. EPA has proposed its “post- 1987” ozone policy in the Federal Register,

stating its plans for implementing the existing Act’s mandate to attain the ozone standard in case

the August deadline passes without further Congressional guidance.

This OTA staff paper was written in response to separate requests by the Senate

Committee on Environment and Public Works and 34 Senators, asking for more information

about S. 1894 and EPA’s proposed post- 1987 ozone policy. The staff paper is part of a larger,

ongoing OTA assessment of the ozone nonattainment issue, requested by the Senate Committee

on Environment and Public Works and the House Committee on Energy and Commerce.

1.

2.

3.

4.

5,

The staff paper contains five chapters:

Summary findings and conclusions.

The effects of ozone, including discussions of the heallh effects of ozone, current

exposure to ozone concentrations above the standard, and the effects of ozone on crops

and trees.

Ways to control ozone, including analyses of the effects of emissions reductions on ozone

concentrations, the sources of the pollutants that lead to ozone formation, the likelihood

of attaining the standard with reductions possible from existing control techniques, and

the costs of controls.

A history of efforts to control ozone since the Clean Air Act Amendments of 1970,

focusing on the last major reauthorization in 1977, and why efforts since 1977 failed 10

bring more areas into attainment with the ozone standard.

A comparison of the three leading proposals addressing the ozone nonattainment

problem.
CONTENTS

Page Number

SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..................... 1

EFFECTS OF OZONE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..7

Effects on Human Health . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Exposure to Ozone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .....,..23

Effects of Ozone on Crops and Forests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ................37

CONTROLLING EMISSIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...............................57

Relationship of Emissions to Ozone Concentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............57

Volatile Organic Compounds:

Characterization of Current and Future Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . ........,....,...........................67

Potential Emissions Reductions

from Control Strategies Analyzed by OTA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Comparison of Potential Emissions Reductions

and Reductions Needed to Attain the Ozone Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95

Costs of Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

OZONE AND THE CLEAN AIR ACT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Evolution of ozone control Under the Clean Air Act. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .........,............. 11-7

State Implementation Plan (SIP) Development and Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

Failure to Meet the Ozone Standard Following the 1977 Amendments . . . . . . . . . . . . . . . . . . . . ................ 122

PROPOSALS FOR CHANGE: S.1894, H.R.3054, AND EPA’S PROPOSAL . . . . . . . . . . . . . . . 129

Overall Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Control Requirements . . . . . . . . . . . . ...................................................................................................... ....... 145

APPENDIX A

Assumptions Used to Calculate Volatile Organic Compound

Emissions Reduction Potential and Associated Costs of Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ................ 159
—

1. SUMMARY

Summarized below are the key findings and conclusions of our staff paper:

Human Health Effects

o Ozone has been shown to cause immediate, short-term changes in lung function and

Increased respiratory symptoms. There is ample evidence that some healthy adults who

exercise heavily for one to two hours during periods of elevated ozone concentrations

(greater than 0.18 ppm) experience pronounced symptoms (such as cough and pain on deep

breathing) and significant decreases in lung function. A number of new studies show some

temporary reduction of lung function among moderately to heavily exercising children and

adults exposed for one to two hours to ozone concentrations comparable to peak levels found

in many nonattainment cities (O. 12-0.16 ppm). Short-term decreases in lung function and

increased respiratory symptoms have also been shown to occur in healthy, exercising

individuals exposed for prolonged periods to ozone as low as the current standard level of

0.12 ppm. Some researchers have expressed concern about effects occurring at ozone

concentrations between 0.08 and 0.12 ppm among people exposed for up to six hours. The

long-term implications of these short-term changes are uncertain.

o Ozone has been suspected of playing a role in the long-term development of chronic

lung diseases. While not dismissing the short-term effects of ozone, many health

professionals appear to be more concerned that repeated exposure to ozone over a lifetime

may result in permanent impairment of the lung. New epidemiologic research suggests that

accelerated rates of decline of lung function with aging occur among residents of

communities with high ozone concentrations. Clinical studies of humans have recently shown

that prolonged exposure to low ozone concentrations results in progressively larger changes in

respiratory function and symptoms with time. Animal studies have shown that prolonged

ozone exposure can cause biochemical and structural injury to the lung. Some of these

changes are suspected of playing a role in the development of chronic lung disease, although

inherent uncertainties in extrapolating from animal data make it difficult to assess human

risk from these studies. Together, these studies suggest that there may be some persistent

effects associated with long-term exposure to ozone. However, at this time our

understanding of the contribution of ozone to the development of chronic lung disease is

limited.

1
o Two groups have been identified by EPA as being potentially at increased risk of

developing adverse health effects when exposed to elevated ozone concentrations: 1) a

subgroup of the general population with preexisting respiratory disease (e.g. asthma, chronic

obstructive pulmonary disease), and 2) those individuals who exercise or work outdoors. The

first group is of concern because their respiratory systems are already compromised. The

strongest evidence of increased risk exists for people who exercise heavily outdoors. They

are at risk because the doses they receive are high due to their increased breathing rate.

EPA also estimates that about 5 to 20 percent of the healthy population may represent a

subgroup of “responders” who may be significantly more responsive than the general

population to the same dose of ozone.

Exposure to Ozone

o Based on 1983-1985 ozone data, 76 areas (encompassing 94 individual metropolitan

statistical areas (MSAs) and 10 non-MSA areas) are in violation of the health-based National

Ambient Air Quality Standard for ozone, which allows no more than one exceedance per

year (on average over three years) of a daily maximum one-hour average ozone concentration

of 0.12 ppm. Approximately 130 million people reside in the 76 areas.

o Based on hourly ozone data for the period 1983-1985, and taking into account

people’s daily activity patterns (e.g. when and where they are indoors and when and where

they are outdoors) and exercise levels, we estimate that about 35 million people -- 25 percent

of the people who reside in nonattainment areas -- are exposed to ozone concentrations

above the standard for at least one hour each year. Nationwide, more than 10 million people

are estimated to be exposed to concentrations above the standard while exercising at

moderate to heavy levels of exertion.

o Outside of the Los Angeles area, people who are exposed to ozone concentrations

above 0.12 ppm during normal activities (i.e., not exercising) are exposed for an average of

about 4 hours per year. People who live in the Los Angeles area and are exposed to ozone

concentrations above 0.12 ppm during normal activities are exposed for an average of more

than 20 hours per year.

Effects of Ozone on Crops and Forests

o At many locations throughout the southern and eastern halves of the United States,

rural ozone concentrations are high enough to reduce yields of economically important crops

by 1 to 20 percent compared to yields that would be expected if ozone concentrations were
at natural background levels. The most heavily affected crops include soybeans, wheat,

cotton, and some types of produce. Agricultural benefits of about $2 billion would be

anticipated if rural ozone concentrations could be reduced by 25 percent.

o Ozone causes foliar injury and reduced growth rates in sensitive trees of several

species. Exposure to ozone can lead to increased susceptibility to diseases and other stresses,

increased mortality of individual trees, and eventually to overall decline of affected species.

All of these effects of exposure to ozone have been observed in forests in the mountains

bordering the Los Angeles basin. Ozone damage has also been observed in ponderosa and

Jeffrey pine at other locations in California. In the eastern United States, ozone is held to be

responsible for widespread foliar injury, reduced growth, and increased mortality in eastern

white pine. Ozone has also been suggested as a causal or contributing agent in reported

declines or growth rate reductions of red spruce, yellow pine and sugar maple.

Sources of Volatile Organic Compounds (VOCs]

o Ozone is not emitted, but rather is produced in the atmosphere from reactions

involving two pollutants: volatile organic compounds (VOCs) and nitrogen oxides (NOX

).

EPA has historically encouraged exclusive reliance on VOC emissions controls to meet the

ambient air quality standard for ozone.

o Nationwide VOC emissions totaled about 19 million tons during 1985. About 7.7

million tons were emitted in nonattainment areas. Without additional regulations, emissions

will decline by about 3 to 5 percent through the mid 1990s, and then slowly rise back to

current levels by 2003. Projected VOC emissions reductions from highway vehicles are

expected to be offset by emissions growth from small stationary sources,

o Highway vehicles contributed about 30 percent of the total VOC emissions in 1985.

Another 30 percent originated from evaporation of organic solvents used in surface coatings,

printing, dry cleaning, and for decreasing metal parts and products. About half of the total

1985 VOC emissions originated from small stationary sources that, individually, emit less

than 50 tons per year.

VOC Emissions Reductions and Costs

o OTA was able to identify potential emissions controls to lower VOC emissions in

nonattainment cities by about 20 percent below current levels by 1993. We believe that the

large majority of VOC emissions reductions possible with currently available control methods

are accounted for in our analysis.

3
o The VOC emissions reductions in nonattainment cities in 1993 from each of the nine

control strategies analyzed by OTA are as follows:

1. “Reasonably availabIe control technology” (RACT) controls on existing stationary

sources: 6 percent;

2. Limits on gasoline volatility: 6 percent;

3. Inspection and maintenance programs for cars and trucks: 3 percent;

4. Federal controls on selected small VOC sources: e.g., consumer and commercial

solvents, architectural surface coatings): 3 percent;

5. Stage II gasoline vapor recovery: 3 percent;

6. “Onboard” technology on motor vehicles to capture gasoline refueling vapors: 1

percent by 1993, 3 percent by 2003;

7. Substitution of methanol for gasoline as fuel for centrally-owned highway vehicle

fleets: 1 percent;

8. Adoption of new “Control Technique Guidelines” for existing stationary sources: 1

percent; and

9. More stringent tailpipe emissions standards for gasoline highway vehicles: less than

1 percent by 1993, 1 percent by 2003.

0 By 1993, after implementation of all the VOC control strategies analyzed by OTA,

many nonattainment cities with peak ozone concentrations less than about 0.14 ppm should

be able to attain the standard. Areas with more severe ozone problems will be able to

significantly lower peak ozone concentrations, but will fall short of attainment. For example,

in areas with current peak ozone concentrations around 0.16 ppm, peak concentrations can be

lowered by about one-third to two-thirds of the way to the standard by 1993. Areas could

come closer to attainment if they are able to implement controls on source categories we

were unable to analyze (e.g. transportation control measures). In some areas, controlling NOX

emissions in addition to VOCs would be effective.

o In nonattainment cities, the costs of control strategies analyzed by OTA range

between $6 billion and $7 billion per year in 1993, and between $8 billion and $9 billion by

2003. Because some controls would apply nationwide, total costs are about $7 billion to $8

billion per year in 1993, and about $10 billion to $11 billion per year by 2003. The rising

costs between 1993 and 2003 are due primarily to the increasing impact of more stringent

highway vehicle emission standards.

o The control strategies analyzed by OTA achieve about one-half the VOC reductions

needed to attain the standard in nonattainment areas. Because we were not able to identify

controls to achieve the other half, we could not estimate total costs to attain the standard.

4
o The cost effectiveness of most strategies falls between about $1,000 and $3,500 per

ton of VOC reduced. “Reasonably available control technology” (RACT) requirements for all

stationary sources and substitution of methanol for gasoline as a highway vehicle fuel are the

most expensive measures, with cost-effectiveness estimates of about $2,900 to $7,300 per ton

of VOC reduced and about $40,000 per ton, respectively. Limiting gasoline volatility is the

least expensive measure, at about $320 to $700 per ton of VOC reduced.

Ozone and the Clean Air Act

o The goal of the Clean Air Act is to “protect and enhance the quality of the Nation’s

air resources.” The Clean Air Act Amendments of 1970 established a partnership between the

States and the Federal Government. EPA sets nationally uniform air quality standards and

the States, with the Agency’s assistance, are responsible for meeting them. Of the six

“criteria” pollutants for which standards have been established, we have been least successful

in our efforts to attain the standard for ozone.

o More than ten years have gone by since the passage of the last major set of

amendments to the Clean Air Act. While some progress has been made in reducing VOC

emissions and lowering ozone concentrations, more than 60 areas do not meet the ozone

standard. As partial explanations for this failure, State and local air pollution control

officials suggest that we did not accurately predict the level of emissions control required to

meet the standard, and that State-level promulgation of regulations has been hindered by lack

of federal support for proposed control measures. EPA officials suggest that emissions

inventories and especially projections of emissions growth have been inaccurate, and that the

deadlines for attainment established in the 1977 Clean Air Act Amendments were

unreasonable. The bottom line, however, is that for a variety of reasons, we have not yet

reduced emissions enough to meet the goal of attainment.

Proposals for Change: S.1894. H.R.3054. and EPA’s Ozone Control Proposal

o H.R.3054 requires nonattainment areas to meet the standard within 3, 5 and 10 years,

depending on the severity of their problem. S. 1894 sets a similar schedule for most areas,

but allows the worst areas 15 years or longer. EPA’s post- 1987 ozone policy establishes the

longest schedules, Rather than establishing absolute attainment deadlines, EPA sets a

schedule for emissions reductions under which some of the worst areas might take over 20

years to attain the standard.

o While none of the proposals alters the Act’s ultimate requirement that the standard be

attained, each adds interim requirements that may in practice be more important driving

forces behind emissions reductions, The most important of these is the requirement for some

5
or all areas to achieve regular increments of emissions reductions, following an explicit

schedule in the proposal, or one assigned by EPA. All the proposals require VOC reductions

in nonattainment areas of about 25 to 40 percent below current levels by 1993, and impose

sanctions if

o The

with S. 1894

the reductions are not achieved.

new proposals also include source-specific technology or

requiring the most source-specific controls and the EPA

Some of the specified measures are to be implemented by the States

performance

proposal the

standards,

fewest.

in nonattainment areas

only, whereas others are federally implemented controls that apply nationwide.

o All three proposals include provisions for NOX controls (which, to date, have only

been required in California) but with varying degrees of flexibility. Flexibility is an issue

because while NOX controls may be necessary to attain the standard at some locations,

controlling NOX in addition to VOCs at other sites will result in ozone levels that are higher

than they would have been after VOC reductions alone. The Senate Environment Committee

proposal is the least flexible, requiring NOX reductions from both existing and new sources in

all nonattainment areas. The EPA proposal is the most flexible, allowing individual areas

discretion to require NOX controls if they judge them to be helpful.

6
2. EFFECTS OF OZONE

In this

description of

forests. Four

chapter we present a summary of the effects of ozone on human health, a

population exposure to ozone, and a discussion of ozone’s effects on crops and

major health effects issues are presented, along with a discussion of the impact

of ozone on the development of respiratory disease, lung function, symptoms, and susceptible

populations. In the exposure section, an assessment of the magnitude and frequency of

violations of the ozone standard in nonattainment areas is made, and factors influencing

ozone exposure in these areas are described as a prelude to estimates of nationwide human

exposure to ozone. Finally, in reviewing the effects of ozone on crops and forests, we

discuss ozone concentrations that occur in rural areas; crop yield reductions associated with

exposure to ozone at these levels; estimates of the agricultural benefits expected to result

from reducing ozone; and potential injury to different tree species due to ozone exposure.

2.1 Effects on Human Healthl

Human exposure to ozone primarily affects the lungs. Ozone has been shown to cause

immediate, short- term changes in lung function and increased respiratory symptoms, and has

been suspected of playing a role in the long-term development of chronic lung diseases. The

immediate or “acute” effects may include some breathing difficulty and coughing, but such

effects appear to be reversible, usually disappearing after a few hours. Ozone has also been

suspected of playing a role in initiating asthma attacks.

Although the short-term effects are important, many health professionals appear to be

more concerned that repeated exposure to ozone over a lifetime may result in permanent

impairment of the lung. Since ozone damages the tissues lining the airways of the lung,

ozone exposure could play a role in accelerated aging of the lung, retardation of lung

development in children, or the

However, existing data are just

term effects of ozone exposure.

concerns about these effects,

development of pulmonary fibrosis, a chronic lung disease.

beginning to shed light on questions about the possible longWe are not yet able to confirm or dismiss many of the

IThe fo]}owing summarv of the he~]th effects of ozone is derived Iargel Y from a draft rePort

.

prepared by Lawrence J. Folinsbee for the Office of Technology Assessment.

7
Major Issues

The debate over health effects from ozone has centered around four major issues: 1)

what are the lowest ozone concentrations at which health effects are observed; 2) what

constitutes an “adverse health effect” from ozone exposure; 3) who appears to be most

susceptible to ozone’s ill effects; and 4) what are the effects of exposure to ozone over a long

period of time? All of these issues play an important role in the standard-setting process.2

Determining the lowest level at which health effects are observed is a crucial first step in

this process. Studies conducted both in the laboratory and in the ambient environment

generate data that help scientists define the lowest observable effects level. Once this level

has been determined, a margin of safety is built into the standard to protect the groups most

sensitive to the pollutant. The margin of safety is designed to protect these populations

against health effects that research has not yet been identified. Deciding which effects are

to be considered “adverse” and determining which populations may be most sensitive to ozone

are essential to setting an “adequate” margin of safety. Information about adverse effects

help policy makers define an upper bound on this margin; information on sensitive

populations assist in defining a lower bound. Studies of the long-term effects of exposure to

a pollutant also provide input to the standard-setting process. These four major issues are

discussed briefly below.

What are the lowest ozone concentrations at which health effects are observed?

The lowest level at which effects from ozone can be observed has been revised

downward during the last 15 years, as more information has become available. In the early

1970’s the threshold for responses to oxidants3 was presumed to be 0.25 parts per million or

“ppm.” This was based on limited data, however.

4 In 1977, new ozone studies showed lung

function effects to exercising persons at concentrations as low as 0.15 ppm. 5 During the last

five years or so, the health effects data base for ozone has greatly expanded. Scientists now

believe that the duration of exposure to ozone and the intensity of exercise during exposure

play the greatest role in determining responses at lower levels of ozone. Some of the most

significant acute effects have been observed during prolonged periods of exposure (6.6 hours)

to ozone and at heavy exercise levels, at concentrations as low as the current standard level

of 0.12 ppm.6 A number of new human studies show that lung function decrements occur in

* The air quality standard for ozone is currently under review bY ‘PA”

Sphotochemical oxidants are a group of chemically-related pOllUtNltS. From the standPoint ‘f

health and welfare effects, ozone is the most important photochemical oxidant. Ozone typically

comprises over 90 percent of the total mass of photochemical oxidants measured in urban air.

4Schoett1in and Landau, 1961.

sDelucia and Adams, 1977

6F01insbee et al., 1988”

8
moderate to heavily exercising children and young

concentrations between 0.12 and 0.16 ppm. 7 8 9 10

at levels between 0.08 and

What is an adverse health

The Clean Air Act

produce “an adverse effect

0.12 ppm are less clear,

effect?

adults exposed for 1 to 2 hours to ozone

The prevalence and significance of effects

and are currently under investigation.

directs EPA to set air quality standards for pollutants that may

on public health or welfare.” A great deal of discussion has been

conducted within the scientific and medical community as to what constitutes an “adverse

health effect,” especially with regard to the effect of ozone inhalation on human lung

function at or below the National Ambient Air Quality Standard. While there is general

agreement that permanent respiratory injury or episodes of pollutant-induced respiratory

illness that interfere with normal activity11 would be considered “adverse,” it is less clear that

small changes in lung function indicators or minor increases in the incidence of respiratory

symptoms constitute an adverse health effect.

The broad continuum of effects and the diversity of scientific opinion make it

difficult to precisely define what is and is not an adverse health effect. The EPA staff

recommends that the threshold for an individual’s adverse respiratory response to acute

ozone exposure include any of the following responses: (See also Table 2- 1.)

- 10 to 200/0 decrement in FEV1 in individuals12 (w/complete recovery

after 6 hrs. );

mild- moderate cough, shortness of breath, pain when inhaling

deeply; and

individual decision to discontinue activity (due to lung function

losses and respiratory discomfort).

Most members of the medical community would consider a 10% or greater group mean loss

in lung function to be sufficient to warrant concern about damage to the lung, especially if

one considers that some individuals in these groups are likely to experience greater than

average lung function decrements. In addition, lung function losses that may not be harmful

7

Linn et al., 1986.

SAVO1 et al., 1987”

9McDonne11 et al., 1983”

I OMc Donnell et al., 1985”

llFerris et al., 1985”

12FEV ~-or the voIume of air exhaled in the first second of a forced expiration--is one measure

of pulmonary funciton that may indicate obstruction in the lungs.

9
10
for people with normal, healthy lungs may be more significant for individuals with

preexisting lung disease. Certainly effects that could be incapacitating and could interfere

with normal activity (e.g. asthma attacks) should be considered adverse. However,

perceptions of what is a medically significant health effect will vary greatly among

physicians and patients.

Are there any subpopulations that are particularly susceptible to ozone’s ill effects?

In response to the Clean Air Act’s mandate that EPA set air quality standards for

pollutants, “allowing an adequate margin of safety ... to protect the public health,” the EPA has

sought to identify those subpopulations, if any, that are shown to be more sensitive to ozone

exposure than the general population.

Two major groups have been identified by EPA as being potentially at increased risk

of developing adverse health effects from exposure to ozone:

1) a subgroup of the general population with preexisting disease (e.g., asthma, chronic

obstructive pulmonary disease); and 2) those individuals who exercise or work outdoors. 13

The first group is of concern because their already compromised respiratory systems may be

at greater risk than individuals without preexisting disease exposed to the same ozone dose.

The second group is at risk because by exercising or working in an outdoor environment,

they are increasing the dose of ozone to their lungs. To date, neither of these groups as a

whole has been clearly shown to be more sensitive to ozone than the rest of the population,

although some individuals with in these groups appear to be more sensitive. The strongest

evidence for a population “at-risk” exists for healthy, heavily exercising individuals.

In addition to the above-mentioned groups, studies have shown that there is a

subpopulation of otherwise healthy individuals who consistently respond more significantly to

the same dose of ozone than do their cohorts. These ozone-sensitive individuals are called

“responder s.” The EPA estimates that from 5-20°A of the healthy population may represent a

subgroup of responders who are at abnormally high risk to ozone exposure .14 The factors

that would account for such individual variability in sensitivity are unknown at this time.

What are the implications of long- term human exposure to ambient ozone levels?

Perhaps the most important health concern with

irreversible damage to the lung from repeated exposure

respect to ozone is the potential for

to ozone over a long period of time.

13Ep ~ OAQpS Draft Staff paper, November 1987. While EPA mentions preexisting reSp iratorjr

disease’ as a characteristic in the second at-risk group, perhaps the more relevant aspect of this

group is that they are exercising, because this will increase the dose of ozone being inhaled into

the lungs.

IAIbid., p. VI- 13.

11
This is especially critical when one considers that a significant percentage of the U.S.

population is living in areas that may experience recurrent episodes of ozone concentrations

at or near the national standard. (For further discussion of population exposure to ozone in

nonattainment areas, see Section 2.2, which follows. )

Ozone can cause acute decrements in lung function and increased respiratory

symptoms in healthy individuals exercising heavily (e.g. competitive running) at

concentrations as low as O.12 ppm. However, while the effects of short-term exposure to

this level of ozone appear to be reversible, it is not known if repeated exposure to ozone

levels in the range of 0.08 to 0.20 ppm would result in extended or, possibly, permanent

changes in lung function or structure. In other words, it is not clear if repetitive exposure to

ozone would cause permanent, chronic health effects.

Both animal and human repeated-exposure studies as well as many epidemiological

studies have attempted to address concerns about the implications of long-term (“chronic”)

exposure to Ozone. Together, these studies have yielded preliminary evidence that there may,

in fact, be some persistent effects associated with chronic exposure. However, estimates of

the risks associated with chronic exposures cannot be made with this limited data base.

The Development of Respiratory Disease

Ozone is suspected of playing a role in the initiation or triggering of respiratory

disease processes. The evidence that suggests that such an effect is plausible comes primarily

from two types of investigations -- animal toxicology studies and human epidemiology

studies -- although human chamber studies may also contribute valuable information.

Animal studies

Animal studies have shown that ozone exposure can cause biochemical and structural

changes in the lung. Some of these changes are suspected of playing a role in the

development of chronic lung diseases. Studies of animals exposed to relatively high levels of

ozone (0.50 ppm) have revealed that it may be responsible for at least temporarily reducing

the ability of the lungs to clear foreign material and, therefore, to ward off infection.15

Several studies have shown an increased response to bacterial infection in animals exposed to

ozone levels as low as 0.08-0.10 ppm for several hours. 16 17 Continuous exposure tO ozone

(at 0.50 ppm) has also been shown to alter the course of viral infection in mice by leading to

15 Foster et d., 1987”

IGMiller et al., 1978.

ITEhrlich et al., 1977.

12
structural changes in the lung that increase the likelihood that fibrosis 18 will occur.19 O n e

type of structural change in the lung which is thought to be linked to the development of

lung fibrosis is the deposition of collagen-- a structural protein that contributes to “stiffening”

of the lung. 20 21 Repeated, intermittent exposure of monkeys to Ozone Concentrations as low

as 0.25 ppm has been shown to result in increased lung collagen content. 22 Breathing

difficulty and subsequent limitation of work performance are characteristic symptoms

associated with lung stiffening. Ozone has also been shown to damage certain lung cells in

23 However, the long-term health Consequences of this animals at levels as low as 0.25 ppm.

cell damage are not known. While many of these studies offer important insights about the

effects of exposure to ozone, the inherent uncertainties in extrapolating from animal data

make it difficult to assess risk to humans from these studies.

Epidemiologic studies

Epidemiologic studies have also been used to investigate the potential link between

24 One question that has received considerable ozone exposure and respiratory disease.

attention is whether regular exposure to oxidant air pollution causes an increased rate of loss

of lung function with age. Part of the normal aging process of the lung involves loss of

“usable lung volume,” perhaps related to the changes in elasticity of the lung known to occur

with aging. (The technical term for this volume is the vital capacity, which is defined as the

maximum volume of air that can be expired after taking a full deep breath. ) If breathing

ozone even at very low levels over a long period of time caused an acceleration of the lung

aging process, we would expect to see a more rapid age-related decline in vital capacity in

people who reside continuously in oxidant-polluted areas. One epidemiological investigation

suggests that an accelerated rate of loss of lung function over a long period (e.g. five years)

25 The evidence is far from conclusive, occurs among residents of high oxidant communities.

however, and the question of what impact ozone may have on lung function over a lifetime

requires further evaluation before a definitive answer can be reached.

lspulmonary fibrosis results from the formation of excessive amounts of Protein fibers that

stiffen the lung. If this stiffening is severe enough, it can produce debilitating disease.

19 Jakab, 1988.

20Last et al, 1 979”

21 Bhatnagar (?t d, 1983”

22 Tyler et d, in press23 Crapo et al, 1984.

z4Epidemio]ogic studies involve large groups of people who are exposed to oxidant air PollutiOn

(mostly ozone) in their daily life and who may experience a variety of adverse responses from

this exposure. The kinds of responses that are examined include changes in lung function over

many years, the rate of occurrence of asthma attacks, the rate at which people with pre-existing

lung disease are admitted to the hospital, and even the death rate from lung or other diseases.

zSDetels et al., 1987”
Human chamber studies

Prolonged acute exposure (up to 6.6 hours) of humans in controlled laboratory settings

to ozone concentrations similar to those found in many nonattainment cities (0.12-0.18 ppm)

have had several effects, including: progressively larger changes in respiratory function and

symptoms with time26 and increased responsiveness of individuals to inhaled substances.27

The relationship between short-term changes in the lung and the progressive development of

chronic structural and functional damage is not known. Some health professionals postulate

that the link between acute and chronic effects is the lung inflammation observed in the

animal and human subjects of short-term ozone studies. Before this inflammatory response

disappears, some suggest that it may induce other changes in the lung that might persist over

time. Airway inflammation is also a feature of the development of a number of respiratory

diseases, most notably asthma and chronic bronchitis.

Issues of susceptibility and adaptation from prolonged exposure

Both animal studies and clinical chamber studies of humans have been used to

investigate the effect of repeated exposure to ozone over an extended period of time (over

several months in animal studies, over several days in human chamber studies). The

importance of such studies is that they help us understand the longer-term effects of ozone

on the lung -- i.e., whether or not prolonged exposure to ozone makes individuals more

susceptible to subsequent exposure to ozone and other pollutants and whether or not lung

function effects are reversible once exposure to ozone ends. Chamber studies of humans

show two notable responses to repeated ozone exposure: 1 ) when an individual is exposed to

ozone on two consecutive occasions separated by less than 48 hours, the second exposure

generally causes greater lung function effects than the first one28 29 and 2) with continued

exposure, these effects begin to diminish in intensity and after four or five days the

pulmonary function effects are undetectable.

30 31 32 This gradual l0SS of functional response

has been called “adaptation.”

26 F01insbee et d., 1988-

27 McDonnell et al., 1987”

zsFo~insbee and Horvath, 1986.

*gBedi et al., 1986.

sl)Horvath et al., 1981“

slKulle et al., 198 2”

s*Linn et al., 1982.

14
The adaptive responses of individuals who live in areas with high ozone levels might

be different from the responses of subjects exposed to ozone for only a few consecutive days

in a laboratory setting. Recent preliminary evidence indicates that people who live in Los

Angeles may become less sensitive to ozone during the entire “smog season” but regain their

33 In this study, "adaptation" did sensitivity during the relatively smog-free winter season.

not disappear rapidly, as in the chamber exposures, but appeared to persist for at least 2-3

months after the end of the smog season. Although this suggests that processes other than

those observed in a chamber may be involved in long-term adaptation to ozone exposure,

further evaluation is needed before a definitive answer can be reached.

Though measurable lung function changes and symptom responses may lessen for a

period, other changes within the lungs are ongoing. In other words, the process of lung

34 Individuals who, through adaptation, experience injury and repair is a continuous one.

fewer or less severe symptoms, may be at increased risk since they may be more able to

tolerate exercise outdoors during peak ozone episodes, and, hence, receive potentially greater

tissue damage over the long-term. Research on animals shows that some lung injury may

continue during an “adaptive” period (e.g. effects on host defense system35 and increased

susceptibility to disease36), even though other measures of response may be reduced.

Lung Function Effects

Ozone has well-documented short-term, reversible effects on lung function. In

studies of people exposed to ozone, the most commonly measured lung function effects are

changes in “forced expiatory volume” (FEV) 37 and “forced vital capacity” (FVC). Ozone can

cause decreases in both of these measures of lung function.

Changes in lung function depend upon the dose of ozone that is ultimately delivered

to the lung. A number of factors influence dose, including the concentration of ozone in the

air, duration of exposure, and the average volume of air breathed per minute, referred to as

the ventilation rate. The ventilation rate increases with exercise intensity. Figure 2-1

describes the dose-response relationship between ozone and FEV1

. As this diagram shows,

an increase in exercise intensity at any given ozone concentration results in a decrease in

group mean FEV1

.

ssHackney and Linn, 1987”

SAEPA “Air Quality criteria for Ozone and Other Photochemical Oxidants,” August 1986.

ssGard~er et al., 1972.

3GGardner and Graham, 1977.

37More ~ommon[y, FEV1, or the volume of air which can be expired in One SeCOnd, wi~~ be

measured.

15
16
Prior to 1980, there was very little information on lung function

controlled exposures to ozone concentrations below 0.30 ppm. This was

under the conditions of rest or mild exercise employed in most of these

changes from

mainly because

studies, there was

little, if any effect from 1-2 hour exposures to ozone levels less than 0.30 ppm. However, a

number of studies, using higher exercise levels, have since shown clear responses to ozone

levels between 0.16-0.24 ppm. 38 394041 Average decreases in group mean FEVI ranged

from 6-22%.

At ozone concentrations approaching the current ambient air quality standard for

ozone, some investigators have seen small (4-6%) but statistically significant group mean

decreases in FVC and FEVI under conditions of heavy exercise,42 43 while others have not.44

45 46 Because of the variability in observed changes in lung function among different

studies, it is difficult to draw any definite conclusions about changes in lung function in the

range of 0.08 to 0.16 ppm ozone for one- or two-hour exposure periods. The most

substantial responses in this range of ozone concentration occur under conditions of heavy

exercise and durations of exposure longer than one hour. For example, Folinsbee and

coworkers recently observed 13% group mean decreases in FEVI in subjects performing

heavy exercise for 6.6 hours at the level of the standard, 0.12 ppm.47

The current controversy surrounding impairment of lung function from ozone

exposure involves the definition of an “adverse” decrement in lung function. Group mean

decreases in either FEVI or FVC of greater than 10 percent are clearly significant enough to

be considered adverse, especially in light of the fact that some individuals within these

groups experience decrements in lung function greater than the average. Temporary and

infrequently occurring changes of less than 10 percent, in and of themselves, probably do not

represent an adverse health effect for a healthy young adult. However, some health

professionals would consider such changes to be adverse if they restrict activity or limit

performance 48

, Short-term reversible decrements in lung function could have adverse effects

in individuals with already reduced lung capacity. However, there is no universal agreement

38 McDonnell et al., 1 983”

sgFolinsbee et al., 1984.

AOAVO1 et al., 198 4’

41Gong et al., 1986.

42 McDonne1 1

, 1983”

43 Gong, 1986.

44Schelegle and Adams, 1986.

45 Ku11e et al., I 985”

AGLinn et al., 1986-

47 Fojjnsbee et al., 1988”

48 Ferris et al., 1985.

17
among scientists as to the implications of such “small” changes. There is also little convincing

evidence available at this time to indicate whether there are long-term consequences from

short-term lung function changes.

Symptom Responses

Symptoms experienced by people exposed to ozone are also important markers of

ozone’s effects. The major symptoms -- cough and pain when breathing deeply -- typically

are observed at about the same ozone exposure levels as are changes in lung function indices;

heavy exercise for one hour at 0.18 ppm will cause such symptoms in groups of healthy

young adults. 49 50 51 Folinsbee and coworkers’ recent study (1988) demonstrated a

relationship at 0.12 ppm between discomfort on deep breathing and changes in lung function

(FVC) using individual data. However, most studies have not shown an association between

symptoms and lung function changes at this ozone concentration on an individual level.

Pronounced symptoms such as repeated coughing or pain when taking a deep breath will

almost always be associated with substantial (greater than 10%) lung function changes.

Adults perceive symptoms of ozone exposure at low concentrations (0.12 ppm)52 but

children apparently do not.

53 54 55 While children are certainly capable of sensing breathing

discomfort, their lack of response from these low level exposures could be the result of a

higher “threshold” of perception for symptoms. It has been suggested that the weak symptom

responses of children may put them at greater risk from ozone exposure because they may

not make efforts to avoid being exposed if they are unable to perceive the effects. Further

research is needed on the sensitivity of children to the symptoms of ozone exposure.

Potentially Susceptible Members of the Population

Implicit in the Clean Air Act’s directive that EPA set air quality standards with an

“adequate margin of safety” is the desire to protect the most sensitive groups in the

population. Many factors may affect susceptibility to ozone exposure, including age, sex,

smoking status, nutritional status, environmental stresses, and exercise level during exposure.

These six factors help EPA identify groups likely to be at increased risk to ozone. At

present, scientists postulate that about 5 to 20 percent of the healthy population may

49 McDonnell et al., 1983”

SOAVO1 et al., 198 4”

6] Kulle et al., 1985.

S* McDonnell et al”$

53 McDonnell et al”*

54AV01 et d., 198 5”

55AV01 et d., 198 7”

1983.

1985.

18
—-

represent a subgroup of “responders”56 who may be significantly more responsive than the

general population to the same dose of ozone. Also considered “at-risk” are asthmatics,

people with pre-existing lung disease, children, the elderly, and individuals who exercise

heavily or work outdoors. Within each of these groups some individuals have demonstrated

greater-than-average sensitivity to a specified dose of ozone, although no particular group

has proven to be more sensitive than the others.

The strongest evidence for increased responsiveness exists for groups who exercise

intensively outdoors because the dose of ozone they receive is much higher than average due

to their increased breathing rate. Because individuals with preexisting lung disease already

have compromised respiratory systems, there is concern that lung function changes and other

respiratory effects may be more serious for these people than for the normal, healthy

population.

Asthmatics

Results of studies on asthmatics are mixed. A number of epidemiological studies of

asthmatics have suggested that ozone exposure may be associated with increased asthma

attacks, hospital admissions for asthma, decrements in lung function, and symptoms.57 58 59

60 Asthmatics have also participated in studies in which lung function and symptoms were

assessed before and after breathing ozone in a controlled laboratory environment. These

studies have consistently shown that the lung function and symptom responses of asthmatics

to a specific level of ozone do not differ from the responses of healthy non-asthmatics.61 62

63

Because of what we know about the significant difference in response to sulfur

dioxide between asthmatics and non-asthmatics, the failure of asthmatics to exhibit increased

sensitivity to ozone in chamber studies is somewhat surprising. However, these have been

group analyses; there may be a subpopulation of asthmatics more sensitive than a subgroup of

“normals” to ozone inhalation. For example, moderate to severe asthmatics have not been

studied in these controlled environments. In addition, chamber studies of asthmatics have

5Gp. VI- 13, “Review of the National Ambient Air Quality Standards for Ozone,” OAQPS Draft

Staff Paper, November 1987.

sTWhittemore and Kern, 1980”

s8Bates and SitZO, 1987”

59 H01guin et al., 1985

GoGong et al., 1987”

GIKoenig et al., 1987”

6zLinn et al., 1978.

63Linn et d., 1980.

19
not yet been conducted at the higher exercise levels that have yielded the most significant

responses in non-asthmatics. The discrepancy between results in epidemiologic and chamber

studies may also be due to interaction between ozone and other environmental factors (i.e.,

other pollutants, high temperatures and humidity) in the field. In other words, there may be

factors operating in the ambient environment that have not been replicated in clinical studies.

Chronic obstructive pulmonary disease (COPD) patients

Patients with chronic obstructive pulmonary disease (COPD) (chronic bronchitis,

emphysema), many of whom are former smokers, are also of concern as an “at-risk” subgroup

because they already have poor lung function and, compared to healthy individuals, relatively

small decrements in lung function could be adverse for them. Several different laboratory

64 65 66 67 68 but none have studies have been conducted on COPD patients exposed to ozone

found them to experience significant reductions in lung function measures (FVC, FEVI

) even

at concentrations as high as 0.30 ppm for 1-2 hours. It will be necessary to study these

individuals over longer periods of exposure and at higher exercise levels in order to

adequately evaluate the risk from ozone exposure faced by COPD patients. Out of concern

for their health, studies of patients with COPD, like those asthma, have not been performed

under such conditions to date.

Children

Children are another potenlially susceptible subgroup of concern. Since the lung

continues to develop until adulthood, the critical question regarding children exposed to

ozone is whether repeated exposure will influence lung maturation. Relatively low

concentrations of ozone (at or around the standard) do appear to have an adverse impact on

the lung function of active children.

69 70 On the basis of both controlled exposure studies

and field studies of ambient pollutant exposure, however, children do not appear to have

lung function effects that are much different than those experienced by adults.

64 Kulle et al., 1984.

G!jLinn et al., 1982.

GGLinn et al., 1983-

‘

7 Solic et al., 1982.

GsKehrl et al., 1985s

‘gMcDonnell et al., 1985.

70 Lippmann et al., 1983.

20
The elderly

Concern has also been expressed for elderly members of the population. A subgroup

of healthy, older adults may be at risk because they may participate in outdoor activities

where they might be exposed to ozone. There is not yet a consensus, however, as to whether

or not this group is at higher or lower risk for pulmonary function and other ozone-related

effects than younger adults. While lung function effects have been observed in this

subpopulation, several studies suggest that healthy older adults may less susceptible to the

71 72 The extent to which pulmonary acute effects of ozone than healthy young adults.

function changes reflect other events occurring in the lung of ozone-exposed older adults is

unknown; further research is necessary to fully evaluate this group.

Athletes

Both epidemiologic and chamber studies have indicated that athletes may be at

substantial risk of experiencing decreases in work performance and decrements in lung

function when exercising for approximately one hour at ozone concentrations as low as 0.20

ppm. 737475 Outdoor workers exposed to ozone for prolonged periods may also be at

increased risk. New research shows that volunteers performing the equivalent of a day of

very heavy manual labor while exposed to 0.12 ppm ozone experience significant loss in lung

function ( 13°/0 group mean decrease in FEVI

) and pronounced symptoms (e.g. cough, pain

76 when inhaling deeply). This research suggests that extended periods of heavy exercise may

be undesirable from the point of view of respiratory health and physical performance, not

only during periods of high ozone concentrations (greater than 0.20 ppm), but also at levels

found in many nonattainment cities (0.12-0.18 ppm).

The acute effects of ozone exposure (e.g. decreases in lung function and symptomatic

responses) are summarized in Figure 2-2, which illustrates the ozone level at which these

effects begin. The figure is divided into two sections: the upper section describes effects

that occur with -1-3 hour exposures, the lower section for 4-8 hour exposures. The tail of

the arrow indicates the concentration at which an effect may begin. At the lowest

concentrations at which effects are seen, the exposures are typically accompanied by very

71 Drechs1er-parks, 1987”

72 Reisenauer et al., 1988”

73 F01insbee et al., 1984S

74Gong et al., 1986.

TsSchlegle and Adams, 1986.

7GFolinsbee et al., 1988.

21
I ACUTE EFFECTS OF OZONE EXPOSURE I

1–3 H ACUTE

I

BACKGROUND OZONE LEVELS

I OZONE EXPOSURE I

EXERCISE PERFORMANCE DECLINE

> 10% DROP IN MEAN FEVI

INCREASED SYMPTOMS

> 10% DROP IN INDIVIDUAL FEV1

● 01 .02 40+

E

I

OZONE PPM (LOG SCALE)

4–8 H ACUTE

OZONE EXPOSURE

> 10% DROP IN INDIVIDUAL FEV .

1

Figure 2-2 . Acute Effects of Ozone Exposure.

No t e : All effects above ozone scale line are associated with 1 - 3

below line are associated with 4-8 h acute expos

may indicate airway obstruction in the lungs,

ure . Also, FEV1

h acute

is one

(short-term)

measure of p

exposure; all effects

ulmonary function that

Source: Draft Report for OTA by Lawrence J, Folinsbee, “A Summary of the Health Effects of Ozone,” Jan. 1988.
heavy exercise. With moderate or mild exercise, effects would begin at higher ozone

concentrations. Also, more adverse responses, such as cell damage shown in laboratory

animal studies, tend to occur at the higher concentrations.

2.2 Exposure to Ozone

Areas Failing to Meet the Standard

An area is designated “nonattainment ” for ozone if concentrations exceeding 0.12 ppm

(1 -hour aver-age) are measured on more than three days over a three year period at any

monitoring site in the area (i.e. the area is expected to exceed the standard more than once

per year, averaged over three years).

Figure 2-3 shows the metropolitan statistical areas (MSAs) and grouped or

“consolidated” metropolitan statistical areas (CMSAs) that were classified as ozone

nonattainment areas based on 1983-1985 monitoring data. The areas are listed in Table 2-2.

As indicated in the table, several non-MSA areas were also designated nonattainment but are

not show n o n the map. 77

EPA updates the list of nonattainment areas every year as data for a new season

become available. Based on the 1983-1985 data, 76 urban areas (encompassing 94 individual

MSAs plus the ten non- MSA areas) were designated nonattainment. In contrast, 62 areas

were designated nonattainment based o n t h e 1984-1986 period ( 16 areas were dropped in

1986 and 2 areas were added), The difference is primarily attributable to differences in

weather between the two periods. The nonattainment list from the 1983-1985 period has

been used here for consistency with other parts of this assessment, and because the list for

the most recent three-year time period -- 1985-1987, is not yet available. The list of

nonattainment areas for 1985-1987 is expected to match the 1983-1985 list more closely than

it matches the 1984-1986 list, because the relatively hot summers of 1983 and 1987 both saw

higher numbers of violations of the ozone standard than the intervening summers d id,

The shading in Figure 2-3 indicates the 1983-1985 “design value” for each area. The

design value is a measure of the highest daily maximum 1 -hour average ozone concentrations

in the area and is the fourth highest of all of the daily peak 1-hour average ozone

concentrations observed with in the area over the most recent three year period. Areas with

design values of 0.13 ppm or higher are violating the ozone standard. On average. the higher

the design value, the greater the level of emissions control required to prevent violations of

77 The non-MSA areas are Do\er, DE; Seaford, DE; Iberville Parish, LA; pointe Coupee Pot-is h,

LA; St. James Parish, LA; Acadia National Park, ME; Gardiner County, ME; Hancock Coun[>,

i’tl E; York County, ME; and Northampton County, VA.

23
24
Table 2-2. Areas classified as nonattainment for ozone based on 1983-1985 data.

* - - non-MSA area. ** -- multi-MSA consolidated area.

Area Name Design Value

(ppm)

0.13 to 0.14 ppm

Acadia National Park, ME*

Allentown-Bethlehem, PA

Birmingham, AL**

Charleston, WV

Charlotte-Gastonia- Rock Hill, NC-SC

Cleveland, OH**

Dayton-Springfield, OH

Denver-Boulder, CO**

Detroit, MI**

Dover, DE*

Erie, PA

Gardiner, ME*

Grand Rapids, MI

Hancock Co., ME*

Harrisburg-Lebanon-Carlisle, PA

Huntington-Ashland, WV-KY-OH

Iberville Parish, LA*

Indianapolis, IN

Jacksonville, FL

Janesville-Beloit, WI

Kansas City, MO-KS

Lake Charles, LA

Lancaster, PA

Miami- Hialeah, FL**

Muskegon, MI

Nashville, TN

Northampton Co, VA*

Pittsburgh, PA**

Pointe Coupee Parish, LA*

Portland, OR-WA**

Portsmouth- Dover-Rochester, NH-ME

Reading, PA

Richmond-Petersburg, VA

St James Parish, LA*

Tampa-St Petersburg-Clearwater, FL**

Tulsa, OK

Visalia-Tulare- Porterville, CA

York, PA

Yuba Citv. CA

0.13

0.14

0.13

0.13

0.13

0.14

0.13

0.13

0.13

0.14

0.13

0.14

0.13

0.13

0.13

0.14

0.13

0.13

0.14

0.13

0.14

0.14

0.13

0.13

0.14

0.14

0.14

0.13

0.13

0.13

0.13

0.13

0.13

0.13

0.13

0.13

0.13

0.13

,7 - 0.13

25
Table 2-2. (Cont.) Areas classified as nonattainment for ozone based on 1983-1985 data.

* - - non-MSA area. ** -- multi-MSA consolidated area.

Area Name Design Value

(ppm)

0.15 to 0.17 ppm

Atlanta, GA

Bakersfield, CA

Baltimore, MD

Baton Rouge, LA

Beaumont-Port Arthur, TX

Boston, MA**

Cincinnati, OH-KY-IN**

Dallas-Ft Worth, TX**

El Paso, TX

Fresno, CA

Longview-Marshall, TX

Louisville, KY-IN

Memphis, TN-AR-MS

Milwaukee, WI**

Modesto, CA

New Bedford, MA

Phoenix, AZ

Portland, ME

Salt Lake City-Ogden, UT

Santa Barbara-Santa Maria-Lompoc, C A

Seaford, DE*

St Louis, MO-IL**

Stockton, CA

Washington, DC-MD-VA

Worcester, MA

York Co, ME*

San Francisco, CA**

0.18 to 0.26 ppm

Atlantic City, NJ

Chicago, IL**

Greater Connecticut**

Houston, TX**

New York, NY**

Philadelphia, PA-NJ**

Providence, RI**

Sacramento, CA

San Diego, CA

0.27 ppm or higher

Los Angeles-Long Beach, CA**

0.16

0.16

0.17

0.16

0.16

0.16

0.17

0.16

0.16

0.17

0.15

0.15

0.15

0.17

0.15

0.16

0.16

0.16

0.15

0.16

0.15

0.16

0.15

0.16

0.15

0.15

0.17

0.19

0.20

0.23

0.25

0.22

0.18

0.18

0.18

0.21

0.36

26
the standard. For the 1983-1985 period, 39 areas had design values of 0.13 or 0.14 ppm, 27

areas had design values of 0.15 to 0.17 ppm, and 10 areas had design values of 0.18 ppm or

more. The highest design value for any area was 0.36 ppm, for Los Angeles, CA.

Frequency and Magnitude of Violations

Figures 2-4 through 2-6 show the areas throughout the contiguous United States

where ozone concentrations exceeded 0.12 ppm, 0.14 ppm and 0.18 ppm, respectively, at least

one hour per year, averaged over the years from 1983 to 1985. By averaging data from all

of the monitors in each area, the maps indicate the number of hours each concentration level

was typically exceeded.78 The data shown were obtained from EPA.

79 The all-monitor

average statistics are assumed to be more representative of air quality throughout each area

than data for the peak monitor (the monitor where the highest concentrations were recorded)

would be. Note that more areas would be expected to exceed the specified concentrations if

data for the peak monitor in each area were used.

Of the 317 (urban and nonurban) areas for which we have ozone data, Figure 2-4

shows the 130 areas where a concentration of 0.12 ppm was exceeded at least one hour per

year, on average, between 1983 and 1985.80 Sixty of those areas had concentrations equal to

or greater than O. 12 ppm six or more hours per year. The Dallas, Houston and Atlanta areas

and parts of California, New York, New Jersey and Connecticut all recorded concentrations

greater than or equal to 0.12 ppm more than 20 hours per year. The maximum number of

hours that monitored ozone concentrations exceeded 0.12 ppm in any one area was 275 hours

per year.

Figure 2-5 shows the 60 areas where the all-monitor average statistics indicate that

ozone concentrations reached 0.14 ppm at least one hour per year between 1983 and 1985.

Twenty-four of these areas recorded ozone concentrations of at least 0.14 ppm six or more

hours per year. Seven areas, namely the Houston area and parts of Connecticut and southern

California, recorded concentrations of 0.14 ppm or higher more than 20 hours per year.

78The number of monitors in each area ranges from one to 18 (in Los Angeles). The average

number of monitors in each area is three.

79 SAROAD, 1987”

801f data for the peak monitor in each area had been used instead of the all monitor average

statistics, 146 areas would be indicated as having ozone concentrations greater than or equal to

0.12 ppm at least one hour per year.

27
I /

28
co

I I I

I
\ I /

30
Figure 2-6 shows the eighteen areas where

for one or more hours per year between 1983 and

indicate that concentrations exceeded 0.18

two areas in Connecticut. Concentrations

three areas in southern California.

Factors Influencing Exposure to Ozone

Just because an individual lives in

ppm six

concentrations were as high as 0.18 ppm

1985. The all-monitor average statistics

or more hours per year in Houston and in

reached 0.18 ppm more than 20 hours per year in

an area where ozone concentrations of 0.14 ppm

(for example) have been measured does not mean that he or she has been exposed to ozone

concentrations at that level, or that if exposed, he or she would experience adverse health

effects. This section discusses some of the factors that determine what a specified measured

ozone concentration means for human health. The factors that need to be kept in mind

include:

1)

2)

3)

How outdoor ozone concentrations vary over time and location within a

city;

Where people are and for how long -- especially how much time they spend

outdoors versus indoors, where concentrations are lower;

People’s activity levels -- which determine their breathing rate and the

depth of the breaths they take, and thus the amount of ozone they inhale

over a given period of time; and

4) Person-to-person variability in how sensitive people are to ozone.

At urban locations, ozone concentrations usually peak during the early to midafternoon, after building up throughout the morning. At suburban and rural locations, the

peak concentrations usually occur later in the afternoon or early evening. Figure 2-7 shows

a profile of ozone concentrations as they change over the day at a single monitoring site.81

The profile is typical of a suburban area downwind of the center of a major city. Especially

at suburban and rural locations, ozone concentrations often stay within 10 to 20 percent of

the peak one-hour average concentration for several hours.

The first step in relating measured ozone concentrations to potential health effects is

to estimate from the monitor readings the pollutant concentrations to which people have

actually been exposed. Figure 2-8 shows a contour map of how peak ozone concentrations

82 The diagram shows on a given day vary across the New York City metropolitan area.

*lA da p

t ed from U.S. EPA, 1986.

szAdapted from Rae, 1987.

31
.

I 1 i

5

a.m . pi-n .

Figure 2-7. Profile of ozone concentrations as they change over the day at a

single monitoring site [adapted from U.S. EPA, 1986]. The profile is typica l

of a suburban area downwind of a strong source area or city center.

32
Figure 2-8. Contour map of the variation in daily peak ozone concentrations

(ppm) predicted for the New York City area using a model with meteorological

conditions and emissions of July 16, 1980 [adapted from Rae, 1987]. As shown,

ozone concentrations typically vary smoothly over a large area and do not show

localized peaks.

33
ozone concentrations predicted using a model, with meteorological conditions and emissions

of July 16, 1980 as inputs. As shown in the example, at any one time, outdoor ozone

concentrations can vary by a factor of two or more across an urban area. However, as shown

in Figure 2-8, ozone concentrations tend to vary smoothly over large areas, and not to show

sharp, localized peaks.83

People who are outdoors during the afternoon when ozone concentrations reach their

peak are apt to be exposed to higher ozone concentrations than people who are indoors. In

air conditioned buildings, indoor ozone concentrations are typically about 30 percent of those

84 Ozone concentrations inside buildings with open measured outdoors at the same location.

windows instead of air conditioning are estimated to be about 60 percent of outdoor

85 Most people spend 80 to 90 percent of their time indoors. Note, however, concentrations.

that some people work or recreate outdoors most of the day. About 5 percent of adult men

work mostly outdoors. An additional 10 percent work outside part of the time. The

proportion of women who work outside is thought to be somewhat lower.86

Two factors determine the total amount of ozone an individual inhales over a given

period of time: (1) the ozone concentrations to which the person is exposed; and (2) the

depth and rate at which the individual is breathing. The depth and rate at which someone

breathes is determined by the level of exercise he or she is performing. Since the amount of

air and thus the amount of ozone inhaled increases with increasing physical exertion, people

who are exercising or doing vigorous labor outdoors are more likely to experience health

effects due to elevated ozone concentrations than people who are sitting, standing or walking

at a leisurely pace. As examples, recreational jogging, swimming and bicycling can

constitute heavy exercise. Those who compete in these sports are likely to be attaining very

heavy exercise levels.87

Ssone exception t. this general rule is that in the plumes of large NoX sources, UP to about a

mile downwind of the source, ozone concentrations can be much lower than in the surrounding

air. This is because extremely high concentrations of NOX without comparably high VOC

concentrations destroy ozone faster than it is produced. However, as the NOX plume disperses,

VOC and NOX levels come into balance and net ozone production results.

84pau1 et al., 1986.

851bid.

86 Pope, 1986.

87A 1984 Gallup survey indicated that about 18 percent of adult Americans jog at least once per

week [Gallup, 1984]. Four out of every 1000 adults (0.4 percent) run more than six miles at

least once per week [Gallup, 1983].

34
As discussed in the section on health effects, clinical and epidemiological studies have

shown that different people respond differently to ozone even when they are exposed to the

same concentrations over the same time period and are breathing at the same rate. From five

to twenty percent of the population of healthy adults are thought to be very sensitive to

ozone. The reasons for their heightened sensitivity have not been established.

population Exposure Estimates

Based on 1984 census estimates88 and the data presented in Figures 2-4 to 2-6,

approximately 130 million people live in areas where ozone concentrations are expected to

equal or exceed O. 12 ppm at least one hour per year. Eighty-six million people live in areas

where concentrations reach at least O. 14 ppm at least one hour per year; 25 million where

concentrations reach at least 0.18 ppm; and 10 million live in the Los Angeles and Anaheim,

CA MSAs where ozone concentrations reach or exceed 0.25 ppm.

Of the 130 million people who live in areas where ozone concentrations reach or

exceed 0.12 ppm, 43 percent (56 million) live in areas where concentrations reach 0.12 ppm

six or more hours per year; 34 percent (44 million) in areas where concentrations reach 0.12

ppm at least 20 hours per year, and almost ten percent (12 million) in areas (Los Angeles,

Riverside and Anaheim, CA) where ozone concentrations

hours each year. As with the maps presented above, it is

preceding estimates are based on the average of all of the

“peak” monitor.

The population statistics presented above might be

reach 0.12 ppm more than 100

important to note that the

monitors in each area, not the

considered the number of people

“potentially” exposed to ozone -- people who, if they were outside at the “right” time and

location, would be exposed to ozone concentrations above the level at which the current

ozone standard is set. Table 2-3 presents estimates of actual exposures: the number of

people who do happen to be in the right place at the right time to be exposed to

concentrations above 0.12 ppm for at least an hour; and for each person who is exposed, the

average number of times each year that exposures occur. The numbers given in Table 2-3

were calculated by combining EPA’s exposure estimates 89 with the number of people we

have estimated who live in areas where ozone concentrations are expected to exceed 0.12

ppm more than one hour per year.

The numbers given in Table 2-3 are broken down by the exercise levels at which the

exposures were estimated to have occurred. Recall that people exercising at higher levels are

expected to be more susceptible to health impacts. Nationwide, 34 million people are

88 Department of COmmerCe, ] 986*

89,MCcurdy, 1988s

35
Table 2-3. Estimated exposures to ozone concentrations above 0.12 ppm

[adapted from McCurdy, 1988]. The estimates are based on hourly ozone data

for the period 1983-1985, and take into account people’s activity pattern s

(e.g . time commuting, time indoors at work, etc.) location throughout the day .

The estimates are broken down according to people’s exercise levels, as thos e

exercising at the higher levels are most apt to be susceptible to health

impacts. The total number of people residing in areas where the ozone standard

was exceeded at least one hour per year, on average during 1983-1985, wa s

approximately 130 million.

Exercis e People Exposed Percent of People in Hours of Exposure

leve l Areas Exceeding 0.12 ppm Per Person Exposed

Nationwide

sedentar y 34 million 26 % 8.8 hours

low 21 million 27 % 8.6 hours

moderate 13 million 27 % 5.7 hours

heavy 80 thousand 23 % 4.1 hours

Nationwide except Los Angeles

sedentar y 24 million 20 % 3.7 hours

low 16 million 23 % 4.6 hours

moderate 10 million 23 % 3.2 hours

heavy 60 thousand 19 % 2.1 hours

Los Angeles

sedentar y 9.7 millio n 97 % 22 hours

low 4,6 millio n 77 % 24 hours

moderate 3.0 millio n 83 % 14 hours

heavy 20 thousand 73 % 10 hours

36
estimated to be exposed each

levels; 13 million at moderate

year at sedentary exercise levels; 21 million at low exercise

exercise levels; and approximately 80 thousand during heavy

exercise. In each exercise category, these numbers represent about 25 percent of the people

who achieve that exercise level some time during the year. Since everyone is sedentary at

some time (e.g. when they are sitting and talking), about 25 percent of the people who live

in areas where ozone concentrations exceed 0.12 ppm are estimated to be exposed to

concentrations at or above this level. By far

exercise levels. Fewer people are exposed at

engage in heavy exercise. Of the nationwide

thousand of the people exposed at sedentary,

residents of the Los Angeles area.

the most people are exposed at sedentary or low

the highest exercise level, because few people

totals, 9.7 million, 4.6 million, 3 million and 20

low, moderate and high levels, respectively, are

On a nationwide basis, people who are exposed to ozone concentrations of 0.12 ppm

at low exercise levels are estimated to be exposed an average of about 9 hours per year;

people exposed at moderate levels an average of 5.7 hours per year; and people exposed at

high exercise levels an average of 4.1 hours per year. However, the national averages mask

considerable variability amongst urban areas. In particular, the national figures are skewed

by the high incidence of exposures in the Los Angeles area. In Los Angeles, the average

numbers of hours people are exposed at sedentary, low, moderate and high exercise levels are

estimated to be 22, 24, 14 and 10 hours per year per person exposed, respectively. For the

rest of the country, with the Los Angeles estimates subtracted out, the estimated numbers of

hours of exposure are, respectively, 3.7, 4.6, 3.2 and 2.1 hours per year for people exposed at

sedentary, low, moderate and high exercise levels.

2.3 Effects of Ozone on Crops and Forests

At concentrations that occur in rural areas throughout the

halves of the United States, ozone reduces yields of economically

southern and eastern

important crops by from

one to 20 percent, compared to yields that would be expected if ozone concentrations did not

90 Annual agricultural benefits on the order of $2 billion exceed natural background levels.

per year [1985 $] would be expected to result from increased crop productivity if ozone

concentrations in rural areas were reduced by 25 percent from current levels. 91 92

Forest damage (visible foliar injury, reduced growth rates, death of individual trees

and succession of dominant species) in Southern California has been clearly linked to

exposure to elevated ozone concentrations. Ozone has been shown to produce foliar injury

goHeck et al., 1984”

glKopp et a]., 1984-

gxKopp et al., 1 98A”

37
and/or reduce growth rates in young trees of numerous species in controlled experiments.

Ozone is suspected as being partially responsible (along with other pollutants and natural

stresses) for forest declines observed in parts of the eastern United States and southern

Canada. Over the last 20 to 25 years, in a variety of locations, significant fractions of the

trees in stands of several species have exhibited foliar injury or decreased growth rates or

both. In several cases, the location and timing of the declines suggest that air pollutants have

contributed. The forest-related benefits of reducing ozone concentrations cannot currently

be estimated.

This section reviews the effects of ozone on crops, indicates where elevated ozone

concentrations correspond to agricultural production, and briefly discusses estimates of the

agricultural benefits of reducing ozone concentrations. The section then reviews what is

understood about the effects of ozone on trees and forest ecosystems, shows the location of

major forested areas, and then discusses five cases in which

cause of forest decline.

Concentrations of Ozone in Rural Areas

Fewer than 100 ozone monitors are located in agricul

ozone has been suggested as a

tural areas across the United

States 93 A number of States do not have any monitors.

. Thus for much of the country, only

rough estimates of ozone concentrations in agricultural and forested areas can be made.

For rural monitors, Figure 2-9 shows daily maximum 7-hour average ozone

94 95

concentrations averaged over the 1984 growing season. The concentrations range from

0.038 to 0.065 ppm. For comparison, the natural background value of the seasonal average

daily maximum 7-hour average statistic is estimated to be between 0.025 and 0.030 ppm.

The highest concentrations are seen at sites in Connecticut, New Jersey, Georgia, Texas and

California. A general trend of increasing seasonal-average concentrations from north to

south is expected due to the fact that sunlight intensity increases as one moves south. Note

that the concentrations shown are from rural, but not necessarily remote monitoring sites,

and may be affected by pollution from urban areas within a few hours upwind.

930AQP$ 1987.

94 N Ap Ap, 1987.

gsRecent studies have suggested that for many CrOpS, CUmUlatiW exposure to ‘zone

concentrations above thresholds of 0.08 to 0.10 ppm is a somewhat better measure of exposure

than the seven-hour seasonal average ozone concentration. However, the seven-hour seasonal

average concentration is more widely reported.

38
I 1

Figure 2-9. Daily maximum 7 -hour average ozone concentrations (ppb) measured

at rural monitoring sites and averaged over the 1984 growing season [NAPAP,

1987 ] .

39
Effects of Ozone on Crops

Visible symptoms of injury due to ozone include light flecks, dark stipples and yellow

spots or patches on plant leaves. Chronic exposures can induce premature “senescence” or

maturation and loss of leaves. The minimum concentrations of ozone that produce acute

foliar injury in susceptible plants exposed for four hours range from 0.04 ppm to 0.09 ppm,

depending on the plant species. 96 Among other environmental factors, light conditions,

temperature, relative humidity and soil water content affect how plants respond to ozone

exposures.

For field and cash crops, the most important responses to ozone are reduced growth

rates and yields. These effects may occur without the visible signs of injury usually

associated with exposure to ozone. However, early senescence of leaves is usually found.

Growth and yield reductions result primarily from reduced photosynthesis and transport of

carbohydrates within plants. Table 2-4 displays the yield reductions predicted to occur for

various crops exposed to seasonal average seven-hour mean ozone concentrations of 0.04 and

0.06 ppm.

97 The yield-reduction predictions are from the National Crop LOSS Assessment

Program (NCLAN), an eight-year study in which crops were grown in the field either in air

filtered to assumed background ozone concentrations, ambient air, or air to which extra

ozone had been added. The reductions shown in the table are relative to the yields obtained

for crops exposed to assumed background ozone concentrations. The range of yield

reductions indicated for each crop indicates differences among varieties.

Figure 2-10 shows state-level production of each of the four crops listed in Table 2-

4. Figure 2-9 showed that seasonal average seven-hour mean concentrations of 0.04 ppm

were widely exceeded in 1984 and that concentrations higher than 0.06 ppm were measured

at a few locations. Note that due to year to year variability in weather, concentrations would

be higher at some sites and lower at others, if data for a year other than 1984 were shown.

Elevated ozone concentrations throughout the south impact cotton. The major soybean

producing regions of the Mississippi and Ohio River valleys and corn producing regions

throughout the eastern half of the United States and Texas are also impacted. High

concentrations affect wheat production in most areas where it is grown, except in the

northern plains states. In addition to the major crops listed in Table 2-4, yield reductions

have been seen with a wide variety of other crops including alfalfa, clover, sorghum, barley,

dry bean, root crops, tomatoes, spinach, lettuce and other produce.

g6Jacobson, 1977, as cited in U.S. EpA, 1987”

“EPA, 1987.

40
Table 2-4. Yield losses predicted to occur for seasonal average seven-hou r

mean ozone concentrations of 0.04 and 0.06 ppm [EPA, 1987]. The 0.04 ppm

level is exceeded throughout the southern and eastern halves of the United

States. The 0.06 ppm level is exceeded in parts of the northeast, California ,

Texas and Georgia. Natural background seasonal average seven-hour mean ozone

concentrations are thought to be about 0.025 to 0.03 ppm.

0.04 ppm ozone 0.06 ppm ozone

percent yield reductio n percent yield reductio n

cotto n 4.6 to 16 16 to 35

wheat 0.0 to 29 0.9 to 51

soybeans 1.7 to 15 5.3 to 24

corn 0.0 to 1. 4 0.3 to 5.1

41
1984 Cotton Production

USDA, Agricultural Statistics, 1985

bales (thousands )

1 to 1000

1000 to 2

more tha n

000

2000

1984 Soybean Production

USDA, Agricultural Statistics, 198 5

bushels (millions )

Figure 2-10. 1984 state-level (a) cotton and (b) soybean production [USDA,

Agricultural Statistics, 1985].

42
1984 Wheat Production

USDA, Agricultural Statistics, 1985

bushels (millions)

200 to 5 0 0

1984 Corn Production

USDA, Agricultural Statistics, 198 5

bushels (millions )

Figure 2-10. 1984 state - level (c) Wheat and (d) corn production [USDA,

Agricultural Statistics, 1985] .

43
Based on NCLAN’s predicted yield responses, economic models of crop supply and

demand have been developed to estimate the agricultural benefits of reducing ozone

concentrations.

98 99 Reductions i n ozone concentrations alter the supply of crops by

increasing yields. Prices are determined by market forces as well as whatever agricultural

price support policies are in place. The models use baseline ozone concentrations that are

extrapolated to rural areas from both suburban and rural monitors (which generally show

similar seasonal average values). While major uncertainties exist in these models, several

investigators have used different models and still been fairly consistent in predicting that

total annual benefits on the order of $2 billion per year [1985 $] would accrue to consumers

and farmers if ozone concentrations in rural areas were reduced by 25 percent. loo Note,

however, that the benefits estimates depend heavily on assumptions about agricultural

policies, base year and background ozone concentrations, and the experimental relationships

between crop yields and ozone concentrations.

Potential Effects of Ozone on Forests

Ozone-induced injury in trees shows up primarily as foliar injury, including leaf or

needle discoloration and premature loss. In extreme cases, leaves and then branches of

injured trees die back. Ultimately individual trees can die prematurely. Effects that may

not be apparent to the eye include reduced growth rates and increased susceptibility to

diseases and other stresses. Reduced photosynthesis and decreased allocation of

carbohydrates to tree roots are possible reasons for the increased susceptibility. Controlled

experiments suggest that growth rates may be reduced by ozone even though the

characteristic visible signs of ozone damage are not present. Weakening of species and

premature death of individual trees can have broad ecological impacts, as species which are

more resistant to ozone take over. All of these effects, including a transition in dominant

species, have been observed in the San Bernardino mountains east of Los Angeles, and

attributed to exposure to ozone originating from emissions in the Los Angeles basin.

Many of the effects of exposure to ozone also occur due to numerous other causes.

In most cases, it is likely that multiple stresses contribute to observed declines, making it

difficult to sort out primary causes or the effect of eliminating or mitigating a single stress.

Effects observed in studies that have been conducted in controlled environments in order to

isolate the effects of ozone do not always match those observed in natural environments.

Moreover, controlled studies have been performed almost exclusively on seedlings or saplings,

98 Adams et al., 1984”

WKOPP et al., 1984.

1OOU.S+ EPA, 1987.

44
rather than mature trees. So, while exposure to ozone has been suggested as an explanation

for several cases of forest or individual species decline in the United States, Canada and

Europe, in most of these cases no consensus exists on the role of ozone.

Figure 2-11 shows the major forested areas of the United States, and identifies the

types of trees that dominate in each area. Comparing Figure 2-11 with Figure 2-9 indicates

that elevated ozone concentrations are present in the western conifer region of California,

and the eastern hardwood and southeastern yellow pine regions. An additional consideration

is that high-elevation forests are likely to be exposed to higher long-term average

concentrations than nearby low-elevation forests, due to the tendency for elevated ozone

concentrations to be maintained at high altitudes overnight and into the morning, while low -

elevation surface concentrations are depleted at night.

Ozone has been suggested as a factor in several confirmed and reported cases of

forest or species decline in the United States.

101 Ozone has been implicated as a cause of

decline in the first two cases discussed below. It has been suggested as a contributing factor

in the other cases.

Ponderosa and Jeffrey pine in the San Bernardino National Forest and other locations in

southern California

Ozone is generally held to be a principal cause of visible injury and accelerated

mortality of ponderosa and Jeffrey pine and other species in the San Bernardino and San

Gabriel Mountains of southern California. The symptoms of injury observed there have

been duplicated in controlled exposure studies. At some sites in the San Bernardino National

Forest east of Los Angeles, daytime (14 hour) average ozone concentrations of 0.10 ppm are

typical during June, July and August. 102 The decline of ponderosa and Jeffrey pine in the

national forest has been so severe that if current trends persist, incense cedar and white fir

are expected to replace them as the dominant species in the forest.103 Growth reductions in

association with visible foliar injury have also been observed in Jeffrey pine at Sequoia and

Kings Canyon National Parks in California.104

White pine in the eastern United States

Controlled exposure studies and field studies support the hypothesis that

concentrations of ozone widely observed in the eastern United States injure white pine trees,

IOINApAp, 1987.

1°21bid.

IOqMcBride et al., as cited in NAPAP, ~ 987.

104peterson et al., 1987.

45
Western conifer -

0 d

\

Figure 2-11. Major forested area s and dominant tree-types of the United

States [NAPAP, 1987].

46
although as with other tree species, not all white

reduced growth rates and increased mortality are

United States.

Red spruce at high elevation sites in the eastern

Since the mid 1960’s, the number of live

105 Foliar injury, pines are equally sensitive.

apparent in trees throughout the eastern

United States

red spruce in some high elevation forests in

the northeast has decreased by 40 to 70 percent. 106 Decreased radial growth, dieback, and

increased mortality have been observed at high elevation sites in the Appalachians from

Vermont and New Hampshire to North Carolina, with the highest mortality rates in the

northeast. 107 Regionwide trends of colder winters and increasing pollutant levels since about

.

1960 have both been suggested as explanations. 108 At above-cloud-base sites in remote or

rural parts of the eastern United States, nighttime and early morning ozone concentrations

are significantly higher than concentrations measured at adjacent sites at lower elevations.

109 Scientists suggest that since The frequent presence of clouds enhances ozone uptake.

conditions at high elevations are marginal for red spruce to begin with, the added stresses of

colder winter temperatures and/or increased air pollution could readily push high elevation

forests into decline.110

Yellow pine in the southeastern United States

Average growth rates in natural stands of yellow pine have been reduced by up to 5 0

111 The causes of the widespread growth percent over rates observed in the late 1950s.

reductions are unknown, but may include the natural aging of the stands, increased

competition from hardwoods, drought, and exposure to air pollution. Preliminary results

indicate that controlled exposure to ozone has similar effects on loblolly pine as have been

observed with other species, including reduced photosynthesis and reduced growth. 112

However, the role of ozone in the yellow pine case has not been firmly established.

105woodman and cOWling, 1987”

1°6NAS, 1986.

1 0 7NAp Ap, 1987.

108NAS, 1986.

109 NAPAP, 1987.

1lONAS, ]986.

‘llSheffieid et al., 1985, as cited in NAPAP, 1987.

llzHeck, 1988.

47
Sugar maple in Pennsylvania, New York, New England and southeastern Canada

Crown dieback and elevated mortality rates became apparent in stands of sugar maple

and associated hardwoods at some locations in southeastern Canada in the late 1970s.

Damage has been noticed more recently in the northeastern United States. Pest infestation or

disease is the apparent cause in all of the cases in the United States, although some of the

113 Air pollution has been suggested as a contributing cases in Canada cannot be explained.

factor. Regionwide average growth rates in the United States have not declined. 114

113NApAp, 1987.

114 Hornbeck et al., 1987, aS cited in NAPAp, 1987.

48
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1985. In: Lee SD, ed. Evaluation of the scientific basis for ozone/oxidants standards

(Houston, TX: November 1984) pp 262-280.

Jakab G. J., “Influenza Virus, Ozone and Fibrogenesis,” Amer. Rev. Respir. Dis. April 1988.

Kehrl H. R., Hazucha M. J., Solic J. J., Bromberg P. A., “Responses of subjects with chronic

obstructive pulmonary disease after exposures to 0.30 ppm ozone,” Am. Rev. Respir. Dis.,

1985, 131:719-724.

Koenig J. Q., Covert D. S., Marshall S. G., Belle G. V., Pierson W. E., “The effects of ozone and

nitrogen dioxide on pulmonary function in healthy and in asthmatic adolescents,” Am. Rev.

Respir. Dis., 1987, 136:1152-1157.

Kulle T. J., Sauder L. R., Kerr H. D., Farrell B. P., Bermel M. S., Smith D. M., “Duration of

pulmonary function adaptation to ozone in humans,” Am. Ind. Hyg. Assoc. J., 1982, 43:832-

837.

Kulle T. J., Milman J. H., Sauder L. R., Kerr H. D., Farrell B. P., Miller W. R., “Pulmonary

function adaptation to ozone in subjects with chronic bronchitis,” Environ. Res., 1984, 34:55-

63.

Kulle T. J., Sauder L. R., Hebel J. R., Chatham M. D., “Ozone response relationships in healthy

non- smokers ,“ Am. Rev. Respir. Dis., 1985, 132:36-41.

Last J. A., Greenberg D. B., Castleman W. L., “Ozone-induced alterations in collagen

metabolism of rat lungs,” Toxicol. Appl. Pharmacol., 1979, 51:247-258.

Linn W. S., Buckley R., Speir C., Blessey R., Jones M., Fischer D., Hackney J. D., “Health

effects of ozone exposure in asthmatics,” Am. Rev. Respir. Dis., 1978, 117:835-843,

Linn W. S., Jones M. P., Bachmayer E. A., et al., “Short term respiratory effects of polluted air:

A laboratory study of volunteers in a high oxidant community,” Am. Rev. Respir. Dis., 1980,

121:243-252.

51
Linn W. S., Fischer D. A., Medway D. A., Anzar U. T., Spier C. E., Valencia L. M., Venet T. G.,

Hackney J. D., “Short term respiratory effects 03 exposure in volunteers with chronic

obstructive pulmonary disease,” Am. Rev. Respir. Dis., 1982, 125:658-663.

Linn W. S., Shamoo D. A., Venet T. G., Spier C. E., Valencia L. M., Anzar U. T., Hackney J. D.,

“Response to ozone in volunteers with chronic obstructive pulmonary disease,” Arch. Environ.

Health, 1983, 38:278-283.

Linn W. S., Avol E. L., Shamoo C. E., Speir L. M., Valencia T. G., Venet D. A., Fischer D. A.,

Hackney, J. D., “A dose response study of healthy, heavily exercising men exposed to ozone at

concentrations near the ambient air quality standard,” Toxicol. Indust. Health, 1986, 2:99-112.

Lippmann M., Lioy P. J., Leikauf G., Green K. B., Baxter D., Morandi M., Pasternack B. S.,

(1983) “Effects of ozone on the pulmonary function of children,” In: Lee S. D., Mustafa

M. G., Mehhnan M. A., eds. International symposium on the biomedical effects of ozone and

related phototchemical oxidants, (Princeton, NJ: Princeton Scientific Publishers, Inc., March

1982), pp. 423-446.

Lippmann M., “Health Significance of Pulmonary Function Tests,” Presented at the 80th

Annual Meeting of APCA. New York, New York. June 21-26, 1987.

McDonnell W. F., Horstman D. H., Hazucha M. J., Seal E., Haak E. D., Sallam S. A., House D. E.,

“Pulmonary effects of ozone exposure during exercise: dose response characteristics,” J. Appl.

Physiol., 1983, 54:1345-1352.

McDonnell W. F., Chapman R. S., Leigh M. W., Strope G. L., Collier A. M., “Respiratory

responses of vigorously exercising children to 0.12 ppm ozone exposure,” Am. Rev. Respir.

Dis., 1985, 132:875-879.

McDonnell W. F., Hortsman D. H., Abdul-Salaam S., Raggio L. J., Green J. A., “The respiratory

responses of subjects with allergic rhinitis to ozone exposure and their relationship to

nonspecific airway reactivity,” Toxicol. Industr. Health, 1987, 3:507-517.

Miller F. J., Illing J. W., Gardner D. E., “Effect of urban ozone levels on laboratoryinduced respiratory infections,” Toxicol. Lett., 1978, 2: 163-169.

Reisenauer C. S., Koenig J. Q., McManus M. S., Smith M. S., Kusic G., Pierson W. E.,

“Pulmonary response to ozone exposures in healthy individuals aged 55 years or greater,”

JAPCA, January 1988, 38:51-55.

Schlegle E. S., Adams W. C., “Reduced exercise time in competitive simulations consequent to

low level ozone exposure,” Med. Sci. Sports Exercise, 1986, 18:408-414.

52
Schoettlin C. E., Landau E., “Air pollution and asthmatic attacks in the Los Angeles area,”

Public Health Rep., 1961, 76:545-548.

Solic J. J., Hazucka M. J., Bromberg P. A., “Acute effects of 0.2 ppm ozone in patients with

chronic obstructive pulmonary disease,” Am. Rev. Respir. Dis., 1982, 125:664-669.

Tyler W. S., Tyler N. K., Last J. A., Gillespie M. J., Barstow T. J., “Comparison of daily and

seasonal exposures of young monkeys to ozone,” Toxicology (in press).

U.S. Environmental Protection Agency, Environmental Criteria and Assessment Office, Air

Quality Criteria for Ozone and Other Photochemical Oxidants, VOl. I of V (Washington, D. C.:

U.S. Environmental Protection Agency, August 1986.

U.S. Environmental Protection Agency, office of Air Quality Planning and Standards, Review

of the National Ambient Air Quality Standards for Ozone Preliminary Assessment of

Scientific and Technical Information, Draft Staff Paper (Washington, D. C.: November 1987).

Whittemore A. S., Kern E. L., “Asthma and air pollution in the Los Angeles area,” Am. J.

Public Health, 1980, 70:687-696.

53
References for Section 2.2

Gallup Poll, “Percentage of Americans who exercise daily up 12 points since 1982/Popularity

of jogging continues to increase,” The Gailup Opinion Index, vol. 226, July, 1984, pp.9-11.

Gallup Poll, “As runners extend distances, percent reporting they jog levels off; half of

Americans exercise regularly,” The Gallup Opinion Index, 1983.

McCurdy, T. R., Office of Air Quality Planning and Standards, U.S. Environmental

Protection Agency, Research Triangle Park, NC, personal communication, February, 1988.

Paul, R. A., Johnson, T., Pope, A., Ferdo, A., and Biller, W. F., National Estimates of

Exposure to Ozone under Alternative National Standards, Contract Number 68-02-4309, (U.S.

Environmental Protection Agency, Research Triangle Park, NC, December 1986).

Pope, A., Development of Activity Patterns to Determine Population Exposure to Ozone,

Contract Number 68-02-4309, (U.S. Environmental Protection Agency, Research Triangle

Park, NC, May 1986).

Rao S. T., Application of the Urban Airshed Model to the New York Metropolitan Area, EPA

450/4-87-01 1, (U.S. Environmental Protection Agency, Research Triangle Park, NC, May

1987).

SAROAD, Storage and Retrieval of Aerometric Data, data base, data files for 1983, 1984 and

1985, (U.S. Environmental Protection Agency, Research Triangle Park, NC, 1987).

U.S. Department of Commerce, State and Metropolitan Area Data Book, 1986, Files on

Diskette, (Washington, DC, 1986).

U.S. Environmental Protection Agency, Air Quality Criteria for Ozone and Other

Photochemical Oxidants, Volume II, EPA/600/8-84/020bF (Research Triangle Park, NC,

August 1986).

54
References for Section 2.3

Adams, R. M., Hamilton, S. A., McCarl, B. A., The Economic Effects of Ozone on Agriculture,

U.S. Environmental Protection Agency, EPA report number EPA-600/3-84-090, (Corvallis,

OR, 1984).

Electric Power Research Institute, Forest Health and Ozone, EPRI report number EA-5135-

SR, (Palo Alto, CA, April 1987).

Heck, W. W., Cure, W. W., Rawlings, J. O., Zaragoza, L. J., Heagle, A. S., Heggestad, H. E.,

Kohut, R. J., Kress, L. W., Temple, P. J., “Assessing impacts of ozone on agricultural crops: II.

Crop yield functions and alternative exposure statistics,” J. Air Pollution Control Association,

VOl. 34, 1984, pp.810-817.

Heck, W. W., personal communication, March 25, 1988.

Hornbeck, J. W., Smith, R. S., Federer, C. A., “Extended Growth Decreases in New England

are Limited to Red Spruce and Balsam Fir,” in Proceedings, International Symposium on

Ecological Aspects of Tree-Ring Analysis, (Lament-Doherty Geological Observatory,

Palisades, NY, 1987).

Jacobson, J. S., “The Effects of Photochemical Oxidants on Vegetation,” in Ozon and

Begleitsubslanzen in Photochemishen Smog, VDI colloquium, (Dusseldorf, West Germany:

Verein deutscher Ingenieure (VDI) GmbH, 1976), pp. 163-173.

Johnson, A. H., McLaughlin, S.B. “The Nature and Timing of the Deterioration of Red Spruce

in the Northern Appalachian Mountains, ” in Acid Deposition: Long-term Trends, (National

Academy Press, Washington, DC, 1986).

Kopp, R. J., Vaughan, W. J., Hazilla, M., Agricultural Sector Benefits Analysis for Ozone:

.Methods Evaluation and Demonstration, U.S. Environmental Protection Agency, EPA report

number EPA-450/5-84-003, (Research Triangle Park, NC, 1984).

McBride, J. R., Miller, P. R., Laven, R. D., “Effects of Oxidant Air Pollutants on Forest

Succession in the Mixed Conifer Forest Type of Southern California,” in Proceedings of the

Symposium On Air Pollutants Effects on Forest Ecosystems, (Acid Rain Foundation, St. Paul,

MN, 1985) pp. 157-168.

National Acid Precipitation Assessment program, Interim Assessment: The Causes and Effects

of Acidic Deposition, Volume III and IV, (Washington DC, 1987).

55
Office of Air Quality Planning and Assessment, Review of the National Ambient Air Quality

Standards for Ozone Preliminary Assessment of Scientific and Technical information,

OAQPS Draft Staff Paper, U.S. Environmental Protection Agency, (Research Triangle Park,

NC, November, 1987).

Peterson, D. L., Arbaugh, M. J., Wakefield, V. A., Miller, P.R. “Evidence of growth reduction

in ozone-stressed Jeffrey pine (Pinus jeffreyi Grev. and Balf. ) in Sequoia and Kings Canyon

National Parks,” J. Air Pollution Control Association, vol. 37, 1987, PP.906-912.

Reich, P. B., Amundson, R.G. ‘Ambient levels of ozone reduce net photosynthesis in tree and

crop species,” Science, vol. 230, 1985, PP.566-570.

Sheffield, R. M., Cost, N. D., Bechtold, W. A., McClure, J. P., Pine Growth Reductions in the

Southeast, Forest Service Southeast Forest Experiment Station Research Bulletin SE-83, (U.S.

Department of Agriculture, 1985).

Woodman, J. N., Cowling, E. B., “Airborne chemicals and forest health,” Environmental Science

and Technology, 21, 1987, pp. 120-126.

56
3. CONTROLLING EMISSIONS

Ozone is not emitted; rather it is produced in the atmosphere from reactions involving

two “precursor” pollutants: volatile organic compounds (VOCs) and nitrogen oxides (NOX).

Development of effective control strategies for ozone requires an understanding of the

relationship between VOC and NOX emissions levels and ozone concentrations. It also

involves identifying measures to control VOC and NOX emissions, and determining the levels

of reductions that can be achieved and the control costs associated with each measure. In

this chapter we discuss ( 1 ) the relationship between ozone and its precursors; (2) the sources

of VOC emissions and estimates of future emissions levels; (3) the VOC emissions reductions

that can be achieved using various control measures and how these compare with levels of

reductions required to meet the ozone standard in current nonattainment areas; and (4) the

costs of various VOC control measures.

3.1 Relationship of Emissions to Ozone Concentrations

Ozone is produced through chemical reactions of nitrogen oxides (NOX) and volatile

organic compounds (VOCs). Because the chemical reactions depend on both sunlight and

temperature, ozone concentrations are highest on hot, sunny days. Nitrogen oxides are

products of fossil fuel combustion. On a nationwide basis, approximately 45 percent of NOX

emissions are from motor vehicles and other mobile sources, 30 percent from utilities, and 12

12 VOCs are a broad class of organic gases such as percent from industrial fuel combustion.

vapors from solvents and gasoline. In urban areas, approximately 40 percent of VOCs are

INational Emissions Data System, Nationwide Emissions Report SummarY, comPuter printout,

U.S. Environmental Protection Agency, Research Triangle Park, NC, January, 1988.

2N0 ~mist.io~s from natural sources are ‘egligible.

x

57
emitted from mobile sources, 30 percent from organic solvent use, and smaller fractions from

other categories including gas station evaporation, solid waste disposal, chemical

manufacturing and petroleum processing. 34

The relationship between ozone and its precursors is complex. Reducing emissions of

either VOCs or NOX may or may not produce a decrease in ozone concentrations, depending

on the mix of pollutants that is present. Reducing NOX can even increase ozone

concentrations, in some situations. The effect of emissions controls on ozone concentrations

depends on meteorological conditions, the absolute and relative amounts of VOCs and NOX

emitted in a particular area, and the background concentrations of ozone and its precursors

that are present. Every urban area has a different balance between VOCs and NOX

.

Furthermore, day-to-day variability in emissions levels, background VOC and NOX

concentrations and wind patterns leads to day-to-day variations in the balance between VOCs

and NOX in each area. Thus the impact of controls on ozone concentrations will change from

day-to-day in a given city, as well as differ across cities. Comparing two different pollution

episodes leading to the same peak ozone concentration, the level of VOC emissions reductions

required to attain the ozone standard will be highest for the episode that has the higher

concentration of VOCs compared to

is true with respect to NOX controls:

efficacy of NOX reductions.

N OX (i.e. the higher “VOC-to-NOX” ratio). The converse

the higher the VOC-to-NOX ratio the higher the

The impact of controls also depends on the distance between the area where the

precursors are emitted and the location where the ozone concentration is monitored. In most

areas, observed peak ozone concentrations occur during mid-to-late afternoon, about 30 miles

downwind of the center of the city. However, concentrations of ozone that are two-to-three

times higher than background levelss may be maintained well beyond that distance, affecting

suburban and rural areas and also contributing to high concentrations in downwind cities. As

the polluted air mass is transported, chemical and physical processes remove NOX more

rapidly than they remove VOCs. Thus in addition to differences in the balance between

VOCs and NOX across days and between different urban areas, for any given pollution

episode there can be a substantial shift from relatively NOX

-rich conditions over the

downtown area to VOC-rich conditions over downwind suburbs and rural areas. Reducing

3

1b id.

AIn urban areas, VOC emissions from natural sources are also insignificant. During the summer,

in areas which are far from heavy traffic and industrial sources of VOCS, vegetation can be the

largest local source of VOC emissions. However, even at their highest levels (in some counties

in the southeast during the summer), over equal land areas, estimated VOC emissions from

vegetation are only about one-fifth of average urban VOC emissions. Moreover, unless NOX is

also present (from power plants or other industrial sources) ozone will not be produced.

‘Background ozone concentrations are estimated to peak at about 0.04 PPm (one-hour average)”

58
VOC emissions is apt to be effective in reducing ozone at downtown locations. Reducing

N OX emissions generally becomes more effective in reducing ozone concentrations downwind

from high emissions regions, over suburban and rural areas.

EPA has historically encouraged exclusive reliance on VOC emissions controls to

ensure compliance with the ambient air quality standard for ozone. NOX emissions controls

have usually been used only to the extent necessary to comply with the standard for nitrogen

dioxide. VOC controls have been emphasized for two reasons: (1) control technologies for

VOCs have been assumed to be cheaper and more readily available than those for NOX and

(2) there has been concern that reducing NOX emissions could increase ozone concentrations

at some locations. 6 Recent measurements of VOC and NOX concentrations in a number of

areas and extension of modeling analyses to consider the build-up of pollutant concentrations

over more than one day, distances further downwind of urban areas, and photochemical

pollutants other than ozone, have suggested that in some areas, NOX controls may be more

effective in reducing photochemical pollution than previously thought.’ 8 9 10

VOC Reductions Required to Meet the Standard

Figure 3-1 presents estimates of VOC emissions reductions needed to reduce local

peak ozone concentrations or “design values” down to 0.12 ppm, the maximum concentration

allowed under the ozone standard. For areas with design values up to 0.20 ppm, the control

requirements shown were estimated using EPA’s standard model (the Empirical Kinetic

Modeling Approach or EKMA model), with a set of meteorological, emissions and transport

conditions selected to approximate conditions in a typical urban area where transport from

11 A moderate amount Of ozone ‘s

upwind cities is not the principal cause of nonattainment.

assumed to be transported from upwind. N OX emissions are assumed to be unchanged from

current levels. The range of estimates given for each design value corresponds to the range

of VOC-to-NOX ratios expected to prevail across different cities with the same design

6Meyer, E.L. ‘r”’ “Review of Control Strategies for Ozone and their Effects on Other

Environmental Issues,” U.S. Environmental Protection Agency, Research Triangle Park, NC,

August 1986.

7Bauges, K., “A Review of NMOC, NOX and NMOC/NOX Ratios Measured in 1984 and 1985,

U.S. Environmental Protection Agency, Report Number EPA-450/4-86-015, Research Triangle

Park, NC, September 1986.

sMilford J B , “photochemical Air pollution Control Strategy Development,” ph. D. Thesis,

Carnegie’ M”el~on University, Pittsburgh, PA, March 1988.

‘Sillman, M. S., “Models for Regional-Scale Photochemical Production of ozone,” Ph.D. Thesis,

Harvard University, Cambridge, MA, November 1987.

IOTrainer M , Williams, EOJ., parrish, D. D., Buhr, M. P., Allwine, E.J., Wesfberg, H“H”~ .

Fehsenfel’d, F. C., Liu, S. C., “Models and observations of the impact of natural hydrocarbons on

rural ozone, ” Nature, 329:705-707 (1987).

llMeyer, E L , Jr., personal cOmmunicatiOn, September, 1987” . .

59
80%

60%

40%

20%

O%

PERCENT VOC CONTROL REQUIRED TO MEET

THE OZONE STANDARD

% VOC Control Required to Meet Standard

high VOC/NOx ratio

low VOC/NOx ratio

o 12 0.13 0.14 0.15 0.16 0.17 0.18 0.19 0.20

Initial Design Value (ppm)

Figure 3-1. VOC emissions reductions estimated to be required to reduce ozone

from the initial peak concentrations or “design values” shown down to 0.12

ppm. The control requirements were estimated using EPA’s standard model, with

meteorological , emissions and transport conditions set to approximat e

conditions in a typical area where transport from upwind cities is not the

principal cause of nonattainment. The range of estimates shown for each

design value corresponds to the range of VOC and N OX ratios expected to

prevail across different cities. The percentage reduction needed to meet the

standard in an individual city will typically fall somewhere between the two

curies shown.

60
value. 12 The estimates shown in Figure 3-1 are for reducing peak ozone concentrations at

monitors that are about 30 miles downwind of an urban center. Situations involving

transport to rural areas or other cities further than about 30 miles downwind will be

discussed later.

To illustrate how to interpret Figure 3-1, the model predicts that for a typical city

with a design value of 0.16 ppm, with no change in NOX emissions levels, VOC reductions

ranging from about 45 to 70 percent will be needed to meet the ozone standard. For areas

where current conditions are usually NOX

-rich (e.g. an ambient VOC-to-NOX ratio of about

8:1 or lower), the VOC reductions required to reduce local ozone concentrations are expected

to be at the lower end of the ranges shown. Where conditions are predominantly VOC-rich

(e.g. an ambient VOC-to-NOX ratio of about 15:1 or higher), control requirements are

expected to fall at the upper end of the range. Generally, the level of VOC control required

to meet the standard locally will be highest for those areas with the highest design values and

the most VOC-rich conditions.

Interim Reductions: The Effect of Lowering VOC Emissions by 35 Percent

As we will discuss later, if all of the controls we were able to analyze were to be

imposed, the total reduction in VOC emissions estimated for most areas would be between 20

and 40 percent, falling short of the levels estimated to be required to attain the standard in

many cities. Figure 3-2 shows the ozone concentrations predicted to result when VOC

emissions are reduced by 35 percent (with NOX emissions unchanged), plotted against initial

design values. The three solid lines represent estimates of final ozone concentrations

expected to result from a 35 percent reduction in VOC emissions with no change in NOX

emissions, if controls are applied in cities with low (8:1), medium ( 12:1) and high ( 15:1)

VOC-to-NO X ratios. The dashed line illustrates “no change” in ozone concentrations, i.e. the

final concentration is the same as the initial concentration or design value. Note that the

ozone standard, 0.12 ppm, is at the bottom of the graph, so that the relative position of a

control scenario line between the “no change” diagonal and the bottom of the graph indicates

what fraction of the reduction in ozone needed to obtain the standard is predicted to be

achieved. For example, if a city has a medium VOC-to-NOX ratio and a design value of

0.16 ppm, a 35 percent reduction in VOC emissions is predicted to yield a final ozone

concentration of about 0.14 ppm, or about half of the reduction estimated to be required to

meet the standard.

VOC reductions obtainable from the control measures we analyzed should be sufficient

to enable most areas with design values of 0.13 ppm to meet the standard. Areas with design

values of O. 14 ppm and low VOC-to-NOX ratios should also be able to attain the standard.

12 Bauge5, OP. cit. ’

footnote 7.

61
0.20

0.19

0.18

0.17

0.16

0.15

0.14

0.13

0.12

EFFECT OF VOC CONTROL ON PEAK OZONE

CONCENTRATIONS FOR A RANGE OF

VOC–TO–NOX RATIOS

Final Ozone (ppm) .- -

0.12 0.13 0.14 0.15 0.16 0.17 0.18 0.19 0.20

Initial Design Value (ppm)

Figure 3-2. Ozone concentrations predicted to result when VOC emissions ar e

reduced by 35 percent, with no change in NOX emissions levels. The thre e

solid lines indicate the ozone concentrations predicted to result in citie s

with low, medium and high VOC to NOX ratios. The dashed line illustrates th e

“no control” case, i.e . the final ozone concentrations are the same as the

initial design values.

62
The reductions we could quantify would be expected to get areas with higher design values

and low VOC-to-NOX ratios more than half way to the standard, in terms of the ozone

reductions they need. Areas with medium to high VOC-to-NOX ratios are predicted to get

less than a third of the reductions they need.

Interim Reductions: The Effect of Adding NO Controls

Figure 3-3 shows the effect of reducing NOX emissions as well as VOCs. Figure 3-3a

shows the effect of adding NOX controls to VOC controls in cities with medium VOC-toN OX ratios; Figure 3-3b in areas with low VOC-to-NOX ratios; and Figure 3-3c in areas with

high VOC-to-NOX ratios. Each of these three figures provides reasonable estimates of the

effect that reducing VOCs and NOX would have on local peak ozone concentrations in

roughly a third of the areas that are not meeting the ozone standard.

As shown in Figure 3-3, the model predicts that for most cities, 35 percent reductions

in both NOX and VOC emissions would reduce ozone concentrations more than 35 percent

reductions in VOCs alone. In fact, the combination is predicted to result in attainment in

some cities -- namely those with low design values and relatively high VOC to NOX ratios,

that would not be predicted to meet the standard if only VOC emissions were to be reduced.

In urban areas with low VOC-to-NOX ratios and high design values, the model predicts

that ozone concentrations would be higher if both VOC and NOX emissions were reduced by

35 percent than if only VOC emissions were reduced (Figure 3-3 b). This result suggests that

N OX controls could be counterproductive for major urban areas that are characterized by low

VOC-to-NOX ratios and high design values -- such as Baltimore, Boston, Los Angeles,

Philadelphia and Washington.

13 14 However a complicating issue in LOS Angeles is that No X 9

controls are expected to be needed to significantly reduce ozone concentrations at some

locations within the air basin, whereas to reduce ozone at other sites VOC controls are

predicted to be needed and NOX controls to be counterproductive. 15 16 N oX controls are a

major thrust of strategies for reducing ozone in the Los Angeles basin. This same issue may

be important in other places with high design values and low characteristic VOC-to-NOX

ratios where the ozone standard is exceeded over a large area (e.g. along the northeast

corridor). However, for areas other than Los Angeles, we lack sufficient information to

determine what combination of VOC and NOX controls might be desirable.

131bid.

ldBauges, K., personal communication, October 1987 ”

15 Mi1ford, OP. clt”’ .

footnote 8.

16South’ Coast Air Quality Management District, “Air Quality Management Plan, 1982 Revision,

Appendix No. VI-A, Ozone Analysis for the South Coast Air Basin,” El Monte, CA, October

1982.

63
EFFECT OF VOC AND NOX CONTROL ON

PEAK OZONE CONCENTRATIONS:

MEDIUM VOC–TO–NOX RATIO

Final Ozone (ppm)

0.20

0.19

0.18

0. 17

0.16

0.15

0.14

0.13

0012

NOX: -35%

0.12 0.13 0.14 0.15 0.16 0. 17 0.18 0.19 0.20

Initial Design Value (ppm)

Figure 3-3. Ozone concentrations predicted to result when VOC emissions ar e

reduced by 35 percent alone or in combination with 35 percent reductions in

N OX emissions. Figure 3-3a shows estimates for cities with medium VOC-to-NOX

ratios , Figure 3-3b cities with low VOC-to-NOX ratios and Figure 3-3c cities

with high ratios. Roughly one-third of the ozone nonattainment areas ar e

thought to be represented by each figure . The dashed line in each figur e

illustrates the “no control” case, i.e . the final ozone concentrations are the

same as the initial design values. The solid lines in each figure show

results with 35 percent reductions in VOC emissions together with O and 35

percent reductions in NOX

. In areas with medium and high VOC-to-NOX ratios

(Figures 3-3a and 3-3c), ozone concentrations are predicted to be furthe r

reduced when NOX controls are added to VOC emissions reductions. In area s

with low VOC-to-NOX ratios (Figure 3-3b), however, ozone concentrations are

predicted to be reduced to the greatest extent by controlling VOC emissions

alone , with N OX emissions reductions of up to 35 percent predicted to be

counterproductive .

64
EFFECT OF VOC AND NOX CONTROL ON

PEAK OZONE CONCENTRATIONS:

LOW VOC–NOX RATIO

Final Ozone (ppm)

0.20 1

0.12 0.13 0.14 0.15 0.16 0.17 0.18 0.19 0.20

Initial Design Value (ppm)

Figure 3-3b.

HIGH VOC–TO–NOX RATIO

0.20

0.19

0.18

0.17

0.16

0.15

0.14

0.13

0.12

0.12 0.13 0.14 0.15 0.16 0. 17 0.18 0.19 0.20

Initial Design Value (ppm)

Figure 3-3c .

65
In general, where high ozone concentrations occur closer to the urban center than

assumed for Figures 3-1 through 3-3, VOC controls are expected to be more effective, and

N OX controls less effective, than illustrated above.

17 18 19 Where high ozone concentrations

occur further downwind than assumed for Figures 3-1 through 3-3, VOC controls are

expected to be less effective, and NOX controls more so, than shown.20 21

Situations Involving Transport of Ozone or its Precursors

Transport of ozone and precursors from upwind cities can complicate efforts to attain

the ozone standard. Moreover, ozone concentrations in nonurban areas may approach or even

exceed 0.12 ppm over an hour or more during the day due to transport from upwind cities.

Elevated ozone concentrations in rural areas are of concern due to forest and crop damage

that may result, in addition to potential health effects.

During the day, due to transport, elevated concentrations of ozone can occur over

areas up to about a hundred miles downwind of urban areas, causing violations of the ozone

standard in relatively sparsely populated, nonindustrial areas. At night, ozone and VOCs can

be transported over distances of 200 miles or more.

22 Polluted air that has been carried at

high altitudes over night mixes with air at the surface during the first few hours after

23 Finally, in association with large-scale sunrise (as ground-level temperatures increase).

high pressure systems that maintain clear skies and elevated temperatures, pollution episodes

24 During these episodes, which occur can last for several days and cover multi-state regions.

 25 26 elevated ozone concentrations over the eastern United States several times each summer, 

17Meyer, Op. cit. ’ footnote 6.

18 Milford, op. Cit., footnote 8“

19 Dodge, M c , ‘Chemistry of Oxidant Formation: Implications fOr Designing Effective COntrOl

. .

Strategies,” Proceedings, North American Oxidant Symposium, Quebec, Canada, February 1987,

20Meyer, Op. cit. ’

footnote 6.

21 Mi1ford, Op. cit”~ footnote 8.

** Spicer, Crew., Joseph, D. W., Sticksel, P. R., ward> ‘S

F

. > “Ozone sources and transport in the

northeastern United States,” Environmental Science and Technology, 13:975-985 (1979).

zsNote that due t. dilution and chemical reactions, the OZOne transported into an area ‘s ‘ot

simply added to the concentration which would otherwise be produced (e.g. 0.10 ppm

transported into an urban area in the morning might only contribute about 0.05 ppm to the peak

ozone concentration observed that day.)

*AVukovich, F. M., Bach, W.D. Jr., Crissman, B“w”> King, W, J., “on the relationship between

high ozone in the rural surface layer and high pressure systems,” Atmospheric Environment,

11:967-983 (1977).

zSSamson, p J , Ragland, K.wo, “ozone and visibility in the midwest: evidence for large-scale

transport,” J: “Applied Meteorology, 16:1101 -1106 (1977).

26vukovich et al., op. Cit., fOOtnOte 24S

66
over both

emissions

for ozone

urban and rural areas can

that enter the system as it

formation.

arise from a combination of transport and fresh

moves, and due to the maintenance of conditions ripe

Transport of ozone and its precursors downwind of source areas on the same day the

precursors were emitted is thought to be the most frequent cause of “rural” nonattainment. It

can also compound ozone problems in urban areas downwind of the original source regions.

Transport on this scale exacerbates nonattainment problems of cities along the northeast

corridor from Virginia to Maine; along the Gulf Coast of Texas and Louisiana; and in

California. Transport that occurs over night or during regional-scale episodes also

exacerbates nonattainment problems in many cities. Although not typically leading to

violations of the ozone standard in rural areas, overnight transport and regional-scale

episodes are thought to account for a significant portion of the ozone measured at rural sites.

N OX controls in upwind cities are generally expected to be more effective than VOC

controls at lowering ozone concentrations in rural areas downwind.27 Both VOC and NOX

controls in upwind areas may be effective for reducing the contribution of transport to ozone

problems in downwind urban areas, because both transported ozone and transported VOCs

can be important.

3.2 Volatile Organic Compounds:

Characterization of Current and Future Emissions

This section describes the sources of volatile organic compound (VOC) emissions and

presents our estimates of the changes in emissions over the next 15 years due to the

offsetting influences of economic growth and

1987. These estimates serve as a baseline for

needed to attain the ozone standard.

Sources of Volatile Organic Compounds

State and federal regulations in place as of

considering the effects of regulatory changes

Table 3-1 displays estimates of 1985 VOC emissions, number of cities, and population

within each of five ozone design value categories. The EPA 1985 National Emissions Data

System (NEDS) inventory is the source of our emissions data and serves as the base inventory

for all future year projections presented in this report. Of the 19 million tons of VOCs

ZTNO controls are also expected to & required to reduce ozone produced locally in rural areas

wher~ VOCS from vegetation react with NOX from power plants and other industrial sources

[Trainer et al., 1987].

67
Table 3-1. SUMMARY OF 1985 VOC EMISSIONS IN NONATTAINMENT CITIES AND

ATTAINMENT REGIONS

Voc Percen t Percen t No. of 1985

Emissions Stationar y Mobile Citie s Population

(1000 tons)

a

(%) (x) (millions)

Nonattainment Cities by

Design Value Category

(in ppm 03

)

Attainment

Regions 11,000 62 38

30.2

55.3

20.2

11.9

117.7

118.8

TOTAL 19,000 61 39 236.5

Source: EPA 1985 National Emissions Data System emissions inventory, January

1988 printout; population data from Bureau of Census.

a Totals are rounded .

68
emitted per year, nationwide, approximately 40

exceeded the ozone standard during the 1983 to

half of the nation’s population.

percent were generated in 94 cities that

28 These regions contain about 1985 period .

Figure 3-4 displays the percent contribution of various source categories to the total

1985 VOC emissions. About two-thirds of the emissions are generated from two main

categories: mobile sources and organic solvent evaporation from stationary sources. About

30 percent of the 1985 emissions inventory is composed of highway vehicle emissions. A

further breakdown of the data, shown in Figure 3-5, reveals that passenger cars are the

largest contributors within the highway vehicle category, with almost 20 percent of the total

1985 VOC emissions, followed by light-duty gasoline trucks with eight percent.

Organic solvent evaporation from stationary sources contributed almost 30 percent of

the total VOC emissions in 1985. The sources within this category are extremely varied and

include such activities as decreasing of metal parts and products, dry cleaning, printing, and

surface coating. The range of individual source sizes (as defined by their individual annual

VOC emission rates) can also be quite wide, ranging from a small gas station decreasing tank

that emits less than a ton per year, to large industrial operations that contain evaporation

sources emitting several hundred tons per year. Figure 3-4 shows that solvent evaporation

from small stationary sources emitting less than 50 tons per year contributes about 25 percent

of total VOC emissions.

Figure 3-6 displays the breakdown of stationary source emissions by source size.

About half of the total 1985 VOC emissions originated from stationary sources that emit less

than 50 tons per year. Because of the way EPA constructs the NEDS emissions inventory, it

is not possible to show, with much certainty, a more detailed breakdown of the “less-than-50

tons-per-year” size class. 29 However, we do know that at least two percent of the inventory

comes from sources emitting between 25 and 100 tons per year, and that this contribution

could be as high as 30 to 40 percent. We have chosen 18 percent as a “rough guess”,

ZSFor our analysis, an area is considered in nonattainment if its design value is greater than 0.1 ~

ppm ozone according to EPA-published 1983-1985 ozone monitoring data. EPA’s actual

determination of nonattainment is based on a slightly different method, but the resulting

number of nonattainment cities are essentially the same. Our number of nonattainment areas

differs from EPA’s count of 61 because, in several cases, EPA has used Consolidated

Metropolitan Statistical Areas (CMSAS), rather than cities. Several of these CMSAS include two

or more cities that we have considered separately.

zgEpA requires States t. report VOC emissions from individual sources that emit more than 50

tons per year. If a large “facility” (that con[ains more than one source) emits more than 100

tons per year of VOCS, each individual source emitting more than 25 tons per year wifhin that

facility must also be reported. EPA uses a “market-balance” approach to indirectly estimate the

aggregate remaining emissions from small sources that are not required to report their em iss ions.

Determination of individual source sizes is, therefore, not possible for these small size

categories.

69
1985 VOC EMISSIONS BY SOURCE CATEGORY

Percent of Total VOC Emission s

o% 10% 20% 30% 40?% 50%

Mobile Sources

Organic Solvent Evap

Gas Station Evap.

Solid Waste Disposal

Chemical Manufact.

Petroleum Industry

Other Industries

Other Fuel Combust.

Miscellaneous

Home Fuel Combustio n

I Highway Vehicles Air, Rail. Marine

Small Miscellaneous Large Industrial

Stationary Solvent Source Solvent

Evaporation Evaporation

Majority of these

emissions not generated

during the ozone season.

(Total emissions = 19.0 million tons/yr)

Figure 3-4. Volatile Organic Compound (VOC ) Emissions by Source Category in

1985. Source: OTA, from EPA’s National Emissions Data System

(NEDS )

Note: Under the category “Organic Solvent Evaporation, “ the subcatego~ “Small Miscellaneous

Stationary. . . “ includea only sources that individually emit less than 50 tons per year of VOC.

70
1985 MOBILE SOURCE VOC EMISSIONS AS A

PERCENTAGE OF TOTAL

(MOBILE PLUS STATIONARY) EMISSIONS

Passenger Cars

LD Gasoline Trucks

Air, Rail, Marine

Off–Highway Vehicles

HD Gasoline Trucks

HD Diesel Trucks

LD = Light-Duty

HD = Heavy-Duty

o% 5% 10% 15% 20% 25%

Percent of Total Emissions

(Total emissions = 19 million tons/yr)

Figure 3-5. Volatile Organic Compound Emissions from Mobile Sources as a

Percentage of Total (Mobile plus Stationary) Emissions in 1985.

71
60%

50%

40%

30%

20%

10%

o%

1985 STATIONARY SOURCE VOC

A PERCENTAGE OF THE ENTIRE

SIZE OF THE INDIVIDUAL

Percent of Total Emissions

EMISSIONS AS

INVENTORY, BY

SOURCE

(Total = 19.0 million tons/yr)

Between 25 and 50 tons/yr

Not known if source size is

less than 25 tons/yr or

between 25 and 50 tons/yr.

Less than 25 tons/yr

Greater than 10 0 50 to 100 Less than 5 0

Individual Source Size (tons/year)

Figure 3-6. Stationary Source Emissions of Volatile Organic Compounds (VOCs)

as a Percentage of the Total Emissions Inventory, By Size of the

Individual Source .

Each bar displays the percentage of total VOC emissions that are contributed by each source-size

class. For example, about 50 percent of total emissions come from sources that emit less than 50 tons per

year. Because of the way the 1985 emissions inventory is constructed, we are unable to give a more precise

detailed breakdown within the “Less-than-50 tons-per-year” category. We have assumed that sources that emit

between 25 and 100 tons per year account for about 18 percent of the total VOC emzssions; this percentage

could be as high as 30 to 40 percent.

72
assuming that

(for which no

about a third of (he small aggregated VOC stationary sources in the inventory

source size can be identified) may, individually, emit more than 25 tons per

year. 30 The uncertainty about the actual sizes Of the less-than-50-ton sources does not

diminish the significant contribution they make to total VOC emissions.

It is important to highlight potentially significant sources of VOC that do not appear

in the 1985 NEDS emissions inventory. Treatment, storage, and disposal facilities (TSDF’s)

are now considered important sources, and will very likely appear in future VOC inventories.

Biogenic sources (e.g., trees and other vegetation) have also been recognized as a potentially

important VOC source category. However, biogenic sources are generally considered to have

little influence on local generation of urban ozone.

Finally, it is important to recognize that all emission inventories have an inherent,

unquantified, level of uncertainty. Given this drawback, any interpretation of emissions

inventory data, including those presented in this report, must be made with caution.

Future VOC Emissions

Tables 3-2 through 3-4 display our projections of VOC emissions in 1993, 1998, and

2003, assuming that existing State and EPA regulations do not change. These projections

serve as a baseline from which to gauge the effectiveness of future regulations; for example,

the changes proposed in recent Congressional bills or EPA’s proposed post- 1987 ozone policy.

Under current regulations, total VOC emissions would decline by approximately five percent

from 1985 levels by 1993, and three percent from 1985 levels by 1998. However, total

emissions are expected to start increasing again sometime after 1998, showing a net increase

of two percent in 2003 from 1985 levels.

The net decrease in VOC emissions between 1985 and 1998 is due to lower emission

31 Although the number of vehicle-miles travelled is forecast to rates from cars and trucks.

increase in many areas over this period, the gradual replacement of current vehicles with

newer, cleaner ones will result in an overall decline in highway vehicle emissions. Figure 3-

7 shows mobile and stationary source VOC emissions through time. VOC emissions from

highway vehicles are projected to decline by about 44 percent between 1985 and 1998.

sOThe 25 -ton _ p e r_ year Size cutoff was chosen so that we could analyze (in a later section) the

emissions reduction potential from stationary sources greater than 25 tons per year. The Clean

Air Act currently requires that, at a minimum, all stationary VOC sources that emit more than

100 tons per year in nonattainment areas must adopt “reasonably available” control methods,

though this cutoff is lower for some categories.

slFuture highway vehicle emissions were projected using EPA eStimates of future highway

vehicle VOC emission rates, combined with estimates of average yearly miles -travelled per

person, and Census Bureau population projections,

73
Table 3-2. SUMMARY OF 1993 VOC EMISSIONS IN NONATTAINMENT CITIES AND

ATTAINMENT REGIONS (Emissions in 1000 tons per year) a

VOC Emissions Change from 1985 Emissions

Tota l Stationary Mobil e Total Stationary Mobil e

Nonattainment Cities by

Design Value

(in ppm 03

)

0.13-0.1 4

0.15-0.1 7

0.18-0.2 6

> 0.26

Category

2,100

3,400

1,100

7 2 0

Total (nonattain.) 7,300

Attainment

Regions 11,000

1,500 570

2,400 980

800 300

490 2 3 0

5,200 2,100

7,600 3,200

-7%

-6%

-3%

- 6 %

-6%

-4%

8%

10%

12%

1 4 %

10%

9%

-32%

-31%

-28%

-31%

-31%

-27%

TOTAL 18,000 13,000 5,300 -5% 9% -28%

a Totals are rounded .

74
.

Table 3-3. SUMMARY OF 1998 VOC EMISSIONS IN NONATTAINMENT CITIES AND

ATTAINMENT REGIONS (Emissions in 1000 tons per year) a

VOC Emissions Change from 1985 Emissions

Tota l Stationary Mobil e Tota l Stationary Mobil e

Nonattainment Cities by

Design Value Category

(in ppm 03

)

0.13-0.1 4 2,100 1,500

0.15-0.1 7 3,500 2,600

0.18-0.2 6 1,100 850

> 0.26 750 530

Total (nonattain.) 7,400 5,500

Attainment

Regions 11,000 8,000

530 -6% 13% -38%

920 -4% 16% -35%

280 o% 19% -32%

220 -2% 2 3 % -35%

1,900 -4% 16% -36%

3,000 -2% 15% -30%

TOTAL 18,000 13,000 5,000 -3% 15% -32%

a Totals are rounded .

75
Table 3-4. SUMMARY OF 2003 VOC EMISSIONS IN NONATTAINMENT CITIES AND

ATTAINMENT REGIONS (Emissions in 1000 tons per year) a

VOC Emissions Change from 1985 Emissions

Tota l Stationary Mobil e Tota l Stationary Mobil e

Nonattainment Cities by

Design Value

(in ppm 03

)

0.13-0.1 4

0.15-0.1 7

0.18-0.2 6

> 0.26

Category

2,200

3,700

1,200

800

Total (nonattain.) 7,900

Attainment

Regions 12,000

1,600 550

2,700 970

900 300

570 230

5,800 2,000

8,400 3,200

-22

2%

7%

5 %

2%

18%

23%

27%

34%

23%

21%

-35%

-32%

-30%

-32%

-32%

-25%

TOTAL 19,000 14,000 5,300 2% 21% -28%

a Totals are rounded .

76
SUMMARY OF

EMISSIONS BY

Emissions

14.0

12.0 - c\

10.0

8.0

6.0

4.0

2.0

0.0

ESTIMATED NATIONWIDE VOC

SOURCE CATEGORY, BY YEAR

(million tons/yr)

11.0

ry

1985 1993 1998 2003

Yea r

Note:

“Small Stationary” = sources

less than 50 tons/yr.

Figure 3-7. Summary of Estimated Nationwide Volatile Organic Compound

Emissions by Source Category, by Year.

The numbers directly above the boxes are the total emissions within the source category. For

example, emissions from Highway Vehicles in 1993 are 3.7 million tons per year.

77
Stationary source emissions, on the other hand, are forecast to increase steadily

between 1985 and 2003, showing a nine percent increase by 1993 and a 21 percent increase

by 2003, over 1985 levels.

32 Small (less than 50 ton-per-year) stationary VOC source growth

is one of the most important reasons why overall VOC emissions are not expected to decline

more rapidly in the earlier years and why total emissions may show a net increase by 2003.

This source category effectively offsets much of the emissions reductions realized from

highway vehicles.

Our projections for large stationary source emissions may be somewhat high because

we are unable to explicitly model all of the control requirements in the Clean Air Act

pertaining to new and modified large VOC emission sources in nonattainment areas.33

However, the effect on our overall emissions estimates is small because, as illustrated in

Figure 3-7, small stationary source growth will have a much more significant impact on

future estimates of total VOC emissions than large stationary sources. In most States, these

more stringent new source regulations do not apply to small sources.

As discussed in the next section, changes in VOC emissions due to the source-specific

regulations currently in place are not sufficient to attain the standard in most nonattainment

cities. In a following section, we discuss the reductions necessary to attain the ozone

standard, as required under the Clean Air Act, and the reduction potential of additional

source-specific controls.

szFuture Jarge stationary source (greater than 50 tOIIS per year) emkiOnS ‘Cre estimated ‘sing

projections of industrial employment growth within Various industrial categories, while small

source growth was based either on industrial employment, estimates of population growth, or

growth in the Gross National Product per capita. References used included:

David South, et all Argonne National Laboratory, “Industrial VOC Model: Regionalized

Forecasts of Uncontrolled Emissions by Source Category, Draft Discussion Paper No. 19 for

Task Group B of the Interagency Task Force on Acid Precipitation,” prepared for U.S.

Department of Energy, Office of Planning and Environment, Washington, D. C., June 1985.

U.S. Department of Commerce, Bureau of Economic Analysis, Survey of Current Business

(Washington, DC: U.S. Government Printing Office, October 1985), pp. 32-36 .,U,S. Department

of Commerce, Bureau of the Census, Statistical Abstracts of the United States, 1981

(Washington, DC: U.S. Government Printing Qffice, 1987), p. 14.

U.S. Department of Commerce, Bureau of Economic Analysis, Survey of Curren/ Business

(Washington, DC: U.S. Government Printing Office, July 1987), pp. 78.

ssThese regulations require that new stationary sources with the Potential to emit more than 100

tons per year install the most stringent emission controls possible @ that VOC emissions from

other existing sources in the area be reduced so that there will be a net decline in emissions

after new operations commence. These same control requirements apply to major modifications

of existing sources that result in a VOC emissions increase of more than 40 tons per year.

78
3.3 Potential Emissions Reductions From Control Strategies

Analyzed by OTA

In this section we

specific control strategies

show how these potential

analyze the VOC emissions reductions from, and costs of, sourcecurrently being considered by the Congress and EPA. We also

emissions reductions compare with estimates of the overall

emissions reductions needed to attain the ozone standard in each nonattainment city.

Discussion of the costs of these control strategies appears in Section 3.5.

We are able to analyze the following source-specific control strategies:

o “Reasonably Available Control Technology" (RACT) on all existing stationary

sources;

o Adoption of new “Control Technique Guidelines” (CTG’s) for several existing

stationary sources of VOC;

o Establishment of new federally-regulated controls on selected stationary VOC

sources;

o “Onboard” technology on motor vehicles to capture gasoline vapor during refueling;

o “Stage II” control devices on gas pumps to capture gasoline vapor during motor

vehicle refueling;

o Inspection and

o More stringent

maintenance (1/M) programs for highway vehicles;

exhaust emission standards for gasoline highway vehicles;

control

o New federal restrictions on fuel volatility; and

o The use of methanol instead of gasoline as a fuel for vehicles in centrally-owned

fleets.

Transportation control measures that limit motor vehicle use are potentially important

strategies that we are unable to analyze at this time.

Throughout the analysis, emissions reductions reported apply to the change occurring

between 1985 and the relevant future year. The emissions reductions reported in our analysis

result from currently available control methods that we know can be applied in the nearterm. We were able to analyze the emissions reduction potential and associated control costs

for strategies applicable to about three-quarters of current VOC emissions. The remaining

79
34 of VOC emissions primarily come one-quarter

could not find applicable control technologies 01

from stationary sources for which we either

that we could not analyze because of a lack

of suitable information. We believe that the large majority of emission reductions possible

with currently available control methods are accounted for in our analysis. This does not

imply that additional VOC reductions beyond those analyzed here are not possible, but that

they should not be counted on within the next five to 10 years.

All control strategies listed above apply to nonattainment cities. Strategies including

federal controls on selected small VOC stationary sources, Onboard controls, more stringent

highway vehicle standards and fuel volatility limitations apply nationwide, not just in

nonattainment cities. It should be noted that both S.1894 and H. R.3054 require some VOC

control in selected attainment areas in States designated as ozone transport regions. However,

because each Congressional proposal sets up slightly different transport regions, we have

chosen to exclude these areas from our analysis.

Tables 3-5 through 3-7 present estimates of emissions reductions achieved in 1993,

1998, and 2003, respectively, if the various control strategies listed above are applied. We

estimate that VOC emissions in nonattainment cities can be reduced by 1.7 million tons per

year in 1993, about 21 percent below 1985 levels. Because some measures are not restricted

to nonattainment areas, approximately 2.7 million tons per year would be eliminated

nationwide. By 2003, total emissions reductions from these control

nonattainment areas increase only slightly to about 1.9 million tons

Again, we must stress that these estimates are for emissions

measures in

per year.

3s

reductions from the

additional controls that we are able to analyze. The remaining one-quarter of the inventory

that we were unable to analyze may contain emissions that could have been reduced by

applying some of these strategies. Therefore, actual emissions reduction potential available

from these additional controls may be greater than represented here. Other potential control

strategies, such as transportation control measures, are not included in our analysis.

Figures 3-8 and 3-9 display our estimates of emissions reductions resulting from each

control strategy in 1993 and 2003, as a percentage reduction below total 1985 emissions in

nonattainment cities. The largest reductions come from instituting RACT on stationary

sources and limiting fuel volatility. The percentage reductions are about the same for most

sAEmissions from treatment, storage, and disposal facilities are not included in this fraction

since they were not included in EPA’s 1985 National Emissions Data System (NEDS) emissions

inventory.

sSNote that the total reductions are slightly lower than the SUm Of the cOrnPOnent categories”

This is because the emissions reductions achieved by (a) lowering fuel volatility in combination

with an I/M program, and (b) combining a Stage 11 and Onboard control program, are slightly

less than instituting each one alone.

80
Table 3-

5. Potential Emissions Reductions in 1993 Compared to 1985 Emissions From Source-Specific Control Strategies

(Emissions in 1000 tons per year)a

Combined Fuel New Highway

New Federal Stage II & Volatility Enhanced Vehicle Methanol ALL

RACT CTG’s Controls Onboard Stage II Onboard Control b

I/M Emis. Stds Fuels CONTROLSC

Nonattainment Cities by

Design Value Category

(in ppm 03)

0.13-0.14

0.15-0.17

0.18-0.26

> 0.26

Total (nonattain.)

Attainment Areas

120 17 61 22 62 63 150 78 7 0 470

240 26 110 38 100 110 230 110 12 0 820

77 5 37 12 30 35 59 33 4 12 250

2 1 6 28 8 0 2 4 o _28 3 _l0 120

460 54 240 81 190 230 440 250 27 22 1,700

0 0 220 87 0 87 710 o 36 0 1,000

00 TOTAL 460 54 460 170 190 320 1,200 250 63 22 2,700

u

a Totals are rounded.

b Estimates are equivalent annual reductions. Actual reductions are required only five months out of the year.

c “All Controls” include RACT, new CTG’s, federal controls, combined Stage II and Onboard, gasoline volatility controls, enhanced I/M, and new mobile

emission standards. Note that total reductions are slightly lower than the sum of each component category. This is because the reductions achieved by

lowering gasoline volatility in combination with an enhanced I/M program, and a combining Stage II and Onboard program, are slightly lower than instituting

each one alone.

Strategy Descriptions:

RACT - “Reasonable Available Control Technology” on all existing stationary sources that emit more than 25 tons per year of VOC.

New Ctg's = Control Technique Guidelines for existing stationary sources that emit more than 25 tons per year of VOC.

Federal Controls on selected small Stationary sources of VOC (consumer and commercial solvents, and architectural surface coatings).

Onboard controls on motor vehicles to capture gasoline vapor during refueling.

Stage II control devices on gas pumps to capture gasoline vapor during motor vehicle refueling.

Fuel volatility control which limit the rate of gasoline evaporation.

Enhanced inspection and maintenance (1/H) programs for cars and light-duty trucks.

New highway-vehicle essission stadards for passenger cars and light-duty gasoline trucks.

Methanol fuels as a substitute for gasollne as a motor vehicle fuel.
Table 3-6. Potential Emissions Reductions in 1998 Compared to 1985 Emissions From Source-Specific Control Strategies

(Emissions in 1000 tons per year)a

Combined Fuel New Highway

New Federal Stage II & Volatility Enhanced Vehicle Methanol ALL

RACT CTG’s Controls Onboard Stage II Onboard Controlb

I/M Emis. Stds Fuel s CONTROL S

C

Nonattainment Cities by

Design Value Category

(in ppm 03)

0.13-0.14

0.15-0.17

0.18-0.26

> 0.26

Total (nonattain. )

Attainment Areas

TOTAL

a Totals are rounded.

b Estimates are equivalent annual reductions. Actual reductions are required only five months out of the year.

c “All Controls” include RACT, new CTG’s, federal controls, combined Stage II and Onboard, gasoline volatility controls, enhanced I/M, and new mobile

emission standards. Note that total reductions are slightly lower than the sum of each component category. This is because the reductions achieved by

lowering gasoline volatility in combination with an enhanced I/M program, and a combining Stage II and Onboard program, are slightly lower than instituting

each one alone.

Strategy Descriptions:

RACT = “Reasonable Available Control Technology” on all existing stationary sources that emit more than 25 tons per year of VOC.

New CTG's = new Control Technique Guidelines for existing stationary sources that emit more than 25 tons per year of VOC.

Federal Controls on selected small stationary sources of VOC (consumer and commercial solvents, and architectural surface coatings).

Onboard controls on motor vehicles to capture gasoline vapor during refueling.

Stage II control devices on gas pumps to capture gasoline vapor during motor vehicle refueling.

Fuel volatility controls which limit the rate of gasoline evaporation.

Enhanced inspection and maintenance (I/M) programs for cars and light-duty trucks.

New highway-vehicle emissions standards for passenger cars and light-duty gasoline trucks.

Methanol fuels as a substitute for gasoline as a motor vehicle fuel.
Table 3-7. Potential Emissions Reductions in 2003 Compared to 1985 Emissions From Source-specific Control Strategies

(Emissions in 1000 tons per year)a

Combined Fuel New Highway

New Federal Stage II & Volatility Enhanced Vehicle Methanol ALL

RACT CTG’s Controls Onboard Stage II Onboard Control b

I/M Emis. Stds Fuels CONTROLSC

Nonattainment Cities by

Design Value Category

(in PPM 03)

Attainment Areas o 0 240 310 0 310 750 0 150 0 1,400

TOTAL 520 56 500 580 240 610 1,200 220 250 21 3,300

a Totals are rounded.

b Estimates are equivalent annual reductions. Actual reductions are required only five months out of the year.

c “All Controls” include RACT, new CTG’s, federal controls, combined Stage II and Onboard, gasoline volatility controls, enhanced I/M, and new mobile

emission standards. Note that total reductions are slightly lower than the sum of each component category. This is because the reductions achieved by

lowering gasoline volatility in combination with an enhanced I/M program, and a combining Stage II and Onboard program, are slightly lower than instituting

each one alone.

Strategy Descriptions:

RACT = “Reasonable Available Control Technology” on all existing stationary sources that emit more than 25 tons per year of VOC.

New CTG's = new Control Technique Guidelines for existing stationary sources that emit more than 25 tons per year of VOC.

Federal Controls on selected small stationary sources of VOC (consumer and commercial solvents, and architectural surface coatings).

Onboard control on motor vehicles to capture gasoline vapor during refueling.

Stage II control devices on gas pumps to capture gasoline vapor during motor vehicle refueling.

Fuel volatility controls which limit the rate of gasoline evaporation.

Enhancad inspection and maintenance (1/M) programs for cars and light-duty trucks.

New highway-vehicle emission standards for passenger cars and light-duty gasoline trucks.

Methanol fuels as a substitute for gasoline as a motor vehicle fuel.
PERCENT VOC EMISSIONS REDUCTIONS IN 1993

COMPARED TO 1985 EMISSIONS, BY CONTROL

STRATEGY

NONATTAINMENT CITIES ONLY

RACT

* Fuel Volatility

Enhanced I/M

* Federal Controls

Stage II

Methanol Fuels

* Onboard

New CTG’s

* New Mobile Std’s.

o% 1% 2% 3% 4% 5% 6% 7%

(Percent Reductions From 1985 Emissions) \ - —- – - –– - - - -- -- - – .

. Emissions reductions are also

achieved tn attainment areas.

Figure 3-8. Percent Volatile Organic Compound (VOC) Emissions Reductions in

1993 Compared to 1985 Emissions, by Control Strategy

Strategy Descriptions

RACT= “Reasonably Available Control Technology” on all existing sources that emit more than 25 tons per

year of VOC.

Fuel Volatility standards that limit the rate of gasoline evaporation.

Enhanced Inspection and Maintenance (I/M) programs for passenger cars and light-duty trucks.

Federal Controls on selected small stationary sources of VOC (consumer and commercial solvents, and

architectural surface coatings).

Stage II control devices on gas pumps to capture gasoline vapor during motor vehicle refueling.

Methanol Fuels as a substitute for gasoline as a ❑ otor vehicle fuel.

Onboard controls on motor vehicles to capture gasoline vapor during refueling.

New CTG's = new Control Technique Guidelines for existing stationary sources that emit more than 25 tons per

year of VOC.

New Mobile Standards = more stringent tailpipe emission standards for passenger cars and light-duty gasoline

trucks.

84
PERCENT VOC EMISSIONS REDUCTIONS IN 2003

COMPARED TO 1985 EMISSIONS, BY CONTROL

STRATEGY

NONATTAINMENT CITIES ONLY

RACT

* Fuel Volatility

Enhanced I/M

* Federal Controls

Stage II

Methanol Fuels

* Onboard

New CTG’s

* New Mobile Std’s.

o% 1% 2% 3% 4% 5% 6% 7%

(Percent Reductions From 1985 Emissions)

. These control strategies will also

create emissions reductions in

attainment areas as well.

Figure 3-9. Percent Volatile Organic Compound (VOC) Emissions Reductions in

2003 Compared to 1985 Emissions, by Control Strategy.

Stratexy Descriptions

RAC T “Reasonably Available Control Technology” on all existing sources that emit more than 25 tons per

year of VCC.

Fuel Volatility standards that limlt the rate of gasoline evaporation.

Enhaocad Inspection and Maintenance (I/M) programs for passenger cars and light–duty trucks.

Federal Controls on selected small stationary sources of VOC (consumer and commercial solvents, and

architectural surface coatings).

Stage II control devices on gas pumps to capture gasoline vapor during motor vehicle refueling.

Methanol Fuels as a substitute for gasoline as a motor vehicle fuel.

Onboard controls on motor vehicles to capture gasoline vapor during refueling.

New CTGs = new Control Technique Guidelines for existing stationary sources that emit more than 25 tons per

year of VOC.

New Mobile Standards = more stringent tailpipe emission standards for passenger cars and light-duty gasoline

trucks.

85
categories in 1993 and 2003, except that the reductions from Onboard controls and new

highway-vehicle standards increase because more of the older vehicles will have been

replaced by newer ones equipped with additional controls. Table 3-8 presents a more

detailed breakdown of percent emissions reductions in 1993. By 1993, total reductions

average about 21 percent in nonattainment cities.

Figure 3-10 displays potential emissions reductions and the percentage of emissions

that remain after all of the reductions have been accounted for. In 1993, after all controls

are applied, emissions are approximately 70 percent of the 1985 total. Most of the remaining

emissions are from small stationary sources that emit less than 25 tons of VOCs per year. As

stated earlier, we are unable to identify controls for approximately one-quarter of the

emissions inventory. About 80 percent of this one-quarter (or about 20 percent of the entire

inventory) are emissions from small stationary sources.

The following subsections summarize the emissions reduction potential of each

individual control strategy.

Reasonably Available Control Technology ( RACT) on All Stationary Sources

The Clean Air Act requires that each State adopt, as part of its State Implementation

Plan (SIP), “reasonably available control technology” (RACT) regulations for existing

stationary sources of VOC in nonattainment cities. In our analysis, we have applied RACTlevel controls on 39 stationary source categories including petroleum refining, certain types

of chemical manufacturing, paper surface coating, automobile surface coating, gasoline

terminals, service stations, and dry cleaning.

The source of our estimates of the percentage reduction in VOC emissions from

RACT and of the data we used to calculate the cost of these controls, is a recent draft report

prepared for EPA by Alliance Technologies Corporation36. EPA made available to us a

series of memos detailing the methods used, technical references, and economic assumptions

used by Alliance, from which our estimates are drawn. A complete list of our control cost

assumptions, including control efficiencies and associated costs for each source type, is

included in Appendix A.

36William H Battye, Mark G. Smith, and Mark Deese, Alliance Technologies Corporation, “cost

Assessment of Alternative National Ambient Air Quality Standards For Ozone, Draft Report,”

prepared for the U.S. Environmental Protection Agency, Office of Air Quality Planning and

Standards, Contract No, 68-02-4317, October 1987.

86
Table 3-8. Percent Emissions Reductions in 1993 Compared to 1985 Emissions From Source-Specific Control Strategiesa

Combined Fuel New Highway

New Federal Stage II & Volatlilty Enhanced Vehicle Methanol ALL

RACT CTG’s Controls Onboard Stage II Onboard Control b

I/M Emis. Stds Fuels CONTROLS C

Nonattainment Cities by

Design Value Category

(in ppm 03

)

Attainment. Areas o 0 2 1 0 1 6 0 <1 0 9

Strategy Descriptions:

RACT = “Reasonable Available Control Technology” on all existing stationary sources that emit more than 25 tons per year of VOC.

New CTG'S = new Control Technique Guidelines for existing stationary sources that emit more than 25 tons per year of VOC.

Federal Controls on selected small stationary sources of VOC (consumer and commercial solvents, and architectural surface coatings).

Onboard controls on motor vehicles to capture gasoline vapor during refueling.

Stage II control devices on gas pumps to capture gasoline vapor during motor vehicle refueling.

Fuel volatility controls which limit the rate of gasoline evaporation.

Enhanced inspection and maintenance (Ire) programs for cars and light-duty trucks.

New highway-vehicle emission standards for passenger cars and light-duty gasoline trucks.

Methanol fuels as a substitute for gasoline as a motor vehicle fuel.
POTENTIAL VOC EMISSIONS REDUCTIONS AND

REMAINING EMISSIONS IN 1993 AS A

PERCENTAGE OF 1985 EMISSIONS

Nonattainment Cities Onl y

Remaining Mobile 20%

Remain.

Remain

Large Stat.

Small Stat

New CTG’s 1%

● Stage II+ Onboard 3%

Methanol Fuels 1 %

Enhanced I/M 3%

New Mobile Std’s 1%

th -

‘w- out Further Control 6%

Notes:

● [n a combmed Stage 11 + On board control program, Stage 11

contributes about 70 percent of the reductions in 1993

Figure 3-10. Potential Volatile Organic Compound (VOC) Emissions Reductions

and Remaining Emissions in 1993 as a Percentage of 1985

Emissions in Nonattainment Citie s

The pulled-out slices represent emissions that can be eliminated by each control strategy. The

three connected slices represent emissions in 1993 that remain after all control strategies are applied.

The category “Expected Reductions without Further Control” represents reductions achieved from existing

State and EPA VOC regulations as of 1985. “Remaining Small Stationary” represents emissions from stationary

sources that emit Less than 25 tons per year of VOC.

Strategy Descriptions

RACT = “Reasonably Available Control Technology” on all existing sources that emit more than 25 tons per

year of VOC.

Fuel Volatility standards that limit the rate of gasoline evaporation.

Enhanced Inspection and Maintenance (I/M) programs for passenger cars and light-duty trucks.

Federal. Controls on selected small stationary sources of VOC (consumer and commercial solvents, and

architectural surface coatings).

Stage II control devices on gas pumps to capture gasoline vapor during motor vehicle refueling.

Methanol FueLs as a substitute for gasoline as a motor vehicle fuel.

Onboard controls on motor vehicles to capture gasoline vapor during refueling.

New

New

CTGs = new Control

year of VOC.

Mobile Standards=

trucks.

Technique Guidelines for existing stationary sources that emit more than 25 tons per

more stringent tailpipe emission standards for passenger cars and light-duty gasoline

88
We estimate the emissions reductions achievable through RACT-level regulations by

simulating controls on all existing stationary sources that emit more than 25 tons of VOCs

per year;

37 in those cities that did not have an existing RACT regulation for a particular

source category in their SIP as of 1985. For this analysis, additional RACT controls are

applied only in nonattainment cities (although some bills also apply controls in selected

attainment areas in States designated as ozone transport regions).

We estimate that applying RACT to all sources in nonattainment cities would lower

VOC emissions by approximately 460 thousand tons per year in 1993, representing a six

percent decline based on 1985 levels. Reductions continue to increase over time, with total

reductions in nonattainment cities in 2003 estimated to be about 520 thousand tons per year,

from 1985 levels.

In the previous subsection, we analyzed the emissions reduction potential of applying

all currently available RACT-level controls on all existing stationary VOC sources. Several

additional stationary source categories are now being considered as candidates for

development of new RACT regulations by EPA. These would be issued as “Control

Technique Guidelines” (CTGs). Like the RACT controls analyzed in the previous section,

nonattainment cities would be required to adopt these “new” RACT regulations on all existing

stationary VOC sources that emit more than 25 tons of VOCs per year.

We are able to analyze the emission reduction potential from controls on ( 1 ) wood

furniture coating, (2) autobody refinishing, (3) plastic parts coating, and (4) coke oven byproduct plants. These four categories represent about one percent of the entire VOC

inventory. Appendix A lists the control efficiency assumptions we used for these sources.

We are unable to analyze the emissions reduction potential from other proposed new-CTG

categories, and at least one of these --treatment, storage, and disposal facilities--might be

quite large.

Emissions reductions from applying new CTG controls that we were able to analyze

are estimated to be about 54 thousand tons per year in 1993, or about a one percent

reduction based on 1985 emissions. This annual total is expected to increase by a few

thousand tons in 2003.

37 Since a large fraction of small stationary sources (i.e., area sources) are reported as aggregate

county-level totals in the 1985 NEDS emissions inventory, we have no way of knowing what

fraction of those aggregate totals are contributed by individual sources greater than 25 tons per

year. Therefore, for our analysis, we have assumed that one-third of the emissions from this

aggregate total are from sources greater than 25 tons per year.

89
Federal Controls on Small VOC Sources

Many small sources of VOCs do not lend themselves to traditional forms of regulation

(e.g., application of an add-on control device to reduce emissions). These sources

individually emit, small amounts of VOCs, but when aggregated over a region, they

collectively contribute a significant portion of the VOC inventory. Such sources include

consumer and commercial solvents, architectural surface coatings, agricultural pesticides,

adhesives, and others.

Although several categories have been proposed as candidates for new federal controls

in recent bills, we are only able to analyze commercial and consumer solvents, and

architectural surface coatings. These two categories represent about nine percent of the

entire emissions inventory. We believe, however, that emissions from these two categories

represent most of the emissions that would fall under proposed federal controls.

EPA control efficiency estimates range between 23 percent38 and 65 percent39 for

40 for commercial and consumer solvents. architectural surface coatings, and about 20 percent

For our analysis, we assume a 25 percent control efficiency for both categories. Since these

would be federally-regulated, emissions reductions would occur nationwide (in nonattainment

and attainment areas).

In 1993, federally-regulated controls on commercial and consumer solvents and on

architectural surface coatings are estimated to reduce VOC emissions by 240 thousand tons

per year in nonattainment cities, and about 220 thousand tons year in attainment areas. By

2003 in nonattainment cities, emissions reductions will reach about 260 thousand tons per

year.

Controls on Gasoline Emissions From Vehicle Refueling

Gasoline vapors that escape from vehicle fuel tanks during refilling can be controlled

by two fundamentally different methods. One method involves installation of a vapor

recovery system on service station gasoline pumps, commonly referred to as “Stage II” vapor

recovery. The other method relies on a control device installed on each vehicle as part of

the emission control system (commonly referred to as “Onboard” controls). Stage II programs

38u s Environmental protection Agency, Office of Air, ‘oise!

Quali~y Planning and Standards, “Control of Organic Emissions

Coating,” preliminary draft, March 1981, p. 3-11.

Wu . .s Environmental protection Agency, office of Air QualitY

“Implications of Federal Implementation Plans (FIP’s) for Post- 1987 Ozone Nonattainment

Areas,” March 1987, p. V-78.

AOIbido, p. v-83.

and Radiation/Office of Air

from Architectural Surface

Planning and Standards,

90
can become fully effective within a few years. The emissions reduction benefits of an

Onboard control program gradually increase over time and achieve full potential after about

10 years, when most older, non-equipped vehicles have been replaced. In the following

subsections, we describe the emissions reduction potential of each program individually, and

in combination.

“Onboard” refueling controls on motor vehicles

For this analysis, we assume that Onboard controls are required on all new gasoline

vehicles starting in 1991 and that by 2003, all gasoline vehicles on the road will be equipped

with Onboard controls due to fleet turnover. Assumptions regarding fleet turnover and

control efficiencies are obtained from EPA’s recent gas-marketing regulatory impact

analysis. 41 42 Because these controls apply to all new gasoline vehicles, emissions reductions

will occur nationwide (in both nonattainment and attainment areas).

We estimate that in 1993, Onboard controls will eliminate about 81 thousand tons per

year of VOC emissions in nonattainment cities, and 170 thousand tons per year nationwide,

representing about a one percent reduction, compared to 1985 emissions. In 2003, total

nationwide VOC reductions increase to about 580 thousand tons per year, or about a three

percent reduction based on 1985 levels. These results reflect only Onboard controls for

vehicle refueling and do not include

analysis of a combined Onboard and

“Stage II” refueling vapor recovery

reductions from additional Stage II controls. An

Stage 11 vapor recovery program is presented later,

Unlike Onboard controls, which are applied nationwide, we assume Stage 11 controls

are only installed in nonattainment cities. Congressional proposals have generally limited the

Stage II requirement to these areas. Emissions reductions in 1993 and 2003 are estimated to

be about 190 thousand and 240 thousand tons per year, respectively, which amounts to about

a three percent reduction in both 1993 and 2003, relative to 1985 emissions. We assume a

control efficiency of 86 percent, which represents EPA’s average estimate for a Stage 11

program with annual enforcement. Note that the percent emissions reductions ultimately

achievable with Stage II and Onboard controls are roughly comparable. However, in 1993,

Onboard is less effective than Stage II, because fleet turnover will have only just begun.

41U,S. Environmental Protection Agency, Office of Air and Radiation, “Draft Regulatory Impact

Analysis: Proposed Refueling Emission Regulations for Gasoline-Fueled Motcr Vehicles--

Volume 1, Analysis of Gasoline Marketing Regulatory Strategies,” EPA-450/3-87-00 la, July

1987, p. 2-33, 3-18.

42We assume that the percent reduction in refueling emissions from use of onboard controls, as

derived from EPA’s gas marketing analysis (Ibid., p. 3- 18), is 28 percent, 58 percent, and 76

percent in 1993, 1998, and 2003, respectively.

91
Combined Stage II and Onboard controls

If both Stage II and Onboard controls are adopted, the percent emissions reductions in

nonattainment cities in 1993 and 2003 are estimated to be about three and four percent,

respectively, relative to 1985 emissions. As the reduction benefits from Onboard controls

increase through time (due to fleet turnover), the benefits from the combined strategy is only

slightly greater than either method above. We assume a combined control efficiency of about

83 percent based on EPA-derived data. 43

Enhanced Motor Vehicle Inspection and Maintenance (1/M) Programs

For this analysis, we define an enhanced motor vehicle inspection and maintenance

(1/M) program as one including all requirements of the existing California I/M program

(among the most stringent in the nation), plus the following improvements: annual testing

for all pollutants (VOC, NOX

, carbon monoxide, and particulate) on all vehicles, improved

visual inspection of the emissions control system to detect tampering and other functional

defects, and a repair cost ceiling of $200 per year. We have assumed that enhanced I/M

programs are instituted in all nonattainment areas. Recent bills also require I/M in selected

attainment cities within States designated as ozone transport regions. However, since the

selection of attainment cities differs between these proposals, we have chosen to limit our

analysis to nonattainment cities.

For cities without an existing I/M program as of 1987, the full emission reduction

benefit of an enhanced I/M program is applied. If a city already had an I/M program as of

1987, then an incremental emission reduction benefit, representing the reductions achieved

by going from an existing to an enhanced program, is applied. Emissions reduction benefit

assumptions are taken from Sierra Research, Inc. (1988).44 We assume that the VOC emission

reduction potential of existing I/M programs is about 12 percent. The full benefit of

enhanced programs is about 30 percent, while the incremental benefit gained by switching

from an existing to an enhanced program is about 17 percent.

43u s Environmental protection Agency, Op. cit., footnote 41 ~ p“ 3-18-

. .

44 Sierra Re5earch, 1nc , “The Feasibility and Costs of More Stringent Mobile Source Emission .

Controls,” contractor report prepared for the Office of Technology Assessment, January 20,

1988. p. 9-23.

92
We estimate that enhanced I/M programs in nonattainment cities will reduce VOC

emissions by about 250 thousand tons per year in 1993 and by 220 thousand tons per year in

2003. 4s This represents about a three percent reduction in both 1993 and 2003, based on

1985 emissions. Enhanced I/M programs become slightly less effective over time because a

larger percentage of the vehicle fleet will be newer, lower-emitting vehicles.

More Stringent Hiqhway-Vehicle Emission Standards

This analysis includes the VOC emissions reduction potential of instituting more

stringent tailpipe controls on new passenger cars and light-duty gasoline-fueled trucks. The

standards we analyzed were determined to be the most stringent technologically feasible,

given currently “available” control technology, according to Sierra Research (1988).46 47

Sierra Research assumes that these standards can be met after 50,000 miles of controlled test

driving for passenger cars, and 120,000 miles for light-duty trucks; however, VOC emission

rates after 50,000 miles (for cars) and 120,000 miles (for trucks) of actual use by vehicle

owners would likely exceed these standards. We assume that new standards go into effect in

1990 for passenger cars, and 1992 for light-duty trucks.

We estimate that new highway vehicle standards reduce VOC emissions by less than

one percent nationwide, in 1993. By 2003, reductions increase to just over one percent

nationwide, compared to 1985 emissions. The increase in emissions reductions during this

period is due to the gradual replacement of older vehicles with newer, cleaner ones.

Limits on Fuel Volatility

Lowering gasoline volatility (i.e., lowering the rate of evaporation) reduces emissions

during refueling at the gas pump and during refilling of underground gasoline storage tanks,

and reduces evaporative emissions from vehicle fuel systems. For this analysis, we assume

that fuel volatility is reduced to nine pounds per square inch during the five-month

summertime period when most ozone concentrations most often exceed the standard.

45 Nitrogen oxides, carbon monoxide, and particulate emissions reduction benefits are also gained

by I/M programs, but are not calculated in this analysis.

46 Sierra Research, Inc., Op. Cit., fOOtnOte 44> p“ 1‘3”

47The new emission standards used h OUr 2UldySk are as follow’s:

(in “grams of pollutant emitted per mile traveled”, g/mile)

Passenger cars -- VOC: 0.25 g/mile; NOX: 0.4 g/mile

Light-duty gasoline trucks (by truck weight) --

(less than 3,750 pounds) VOC: 0.34 g/mile; NOX: 0.46 g/mile

(3,751 to 6,000 pounds) VOC: 0.43 g/mile; NOX: 0.80 g/mile

(6,000 to 8,500 pounds) VOC: 0.55 g/mile; NOX: 1.15 g/mile

93
However, for purposes of comparing total annual emissions reductions, we have scaled up the

annual emissions reductions as though the volatility limits would be in effect year-round.

Data for the analysis comes from EPA48

.

We estimate that limiting gasoline volatility would lower VOC emissions by about six

percent in both nonattainment and attainment areas in 1993. Actual emissions reductions, in

1993, are estimated to be about 1.2 million tons per year, nationwide, of which about 440

thousand tons per year are achieved in nonattainment cities (actual VOC emissions reductions

would be about 500 thousand tons nationwide, and 180 thousand tons in nonattainment areas,

during the five-month ozone season). Total reductions stay relatively constant between 1993

and 2003.

Alternative Motor Vehicle Fuels: Methanol

H.R.3054 and S.1894 both mandate the use of ‘alternative” motor vehicle fuels for

some ozone nonattainment areas. The “alternative” fuel which is most commonly considered

for reducing ozone is methanol (either 100 percent or “neat” methanol, or a blend of at least

85 percent methanol and up to 15 percent gasoline). Current U.S. production of methanol

totals about one billion gallons per year, mostly from natural gas. About 300 million gallons

are currently used in oxygenated fuel blends.’g

Methanol is a VOC that reacts more slowly in the atmosphere and consequently

produces less ozone than VOCs emitted from combustion and evaporation of gasoline. Per

mile travelled, substituting methanol for gasoline as motor vehicle fuel is roughly estimated

to be between 30 to 90 percent as effective in reducing ozone concentrations as completely

50 Based on these estimates, eliminating the emissions from the gasoline-fueled vehicles.

substituting methanol for gasoline for 10 percent of the vehicle miles travelled (VMT) in an

area would yield the same ozone benefits as simply reducing VMT by three to nine percent.

The relative ozone-producing potential of gasoline and methanol-fueled vehicles depends on

assumptions about the volatility limits imposed for gasoline, exhaust and evaporative

emissions limits imposed on both gasoline and methanol-fueled vehicles (including limits on

48u s Environmental protection Agency, office of Air and Radiation, OffiCe of Mobile

. .

Sources, “Draft Regulatory Impact Analysis: Control of Gasoline Volatility and Evaporative

Hydrocarbon Emissions from Motor Vehicles,” July 1987.

‘

g

’’ Oxygenated fuel blends” refers to gasoline to which either ethanol (grain alcohol), methanol

plus ethanol, or methyl tertiary butyl ether (MTBE), a methanol derivative, has been added,

resulting in a mixture which is about 90 percent gasoline by volume. S. 1894 and H. R.3054

mandate the use of oxygenated fuel blends during the colder months of the year in carbon

monoxide nonattainment areas.

sou s Environmental protection Agency, ‘lGUi&nCe on Estimating Motor Vehicle Emission . .

Reductions from the Use of Alternative Fuels and Fuel Blends,” EPA report number EPA-AATSS-PA-87-4, Research Triangle Park, NC, January 1988.

94
total VOCs, methanol, and formaldehyde -- a relatively reactive product of methanol

combustion as well as gasoline combustion), and how vehicle design is optimized for

methanol use.

Methanol substitution: centrally-owned fleets

S.1894 and H.R.3054 both include provisions for use of alternatively fueled vehicles

in centrally owned vehicle fleets. In 1986, six million cars and two million light trucks in

centrally owned fleets of 10 or more vehicles accounted for an estimated 15 percent of VMT

nationwide. 51 For our analysis, we assume that all centrally owned fleets of 10 or more

light duty vehicles in areas with design values of 0.18 ppm or higher will be required to

operate strictly on neat methanol by 1993.52 Further assuming that on a per mile basis,

substituting methanol for gasoline is equivalent to reducing VOC emissions by half, a yearround requirement that methanol be substituted for gasoline would result in total VOC

reductions in areas with design values of 0.18 ppm or higher of about 22,000 tons.

Compared to 1985 VOC emissions, this is an average reduction of about 1.2 percent in each

area.

3.4 Comparison of Potential Emissions Reductions and Reductions

Needed to Attain the Ozone Standard

Without Additional Controls

Figure 3-11 shows variability among nonattainment cities in

emissions predicted to occur between 1985 and 1993, assuming that

the changes in VOC

nothing is added to

existing State and EPA regulations. For each city, at its design value, we have graphed the

percentage change in emissions from the 1985 baseline expected to occur due to the

regulations included in State Implementation Plans (SIP) as of 1985, the current Federal

Motor Vehicle Control Program, and population and economic growth.

We have graphed cities by design value because it is a reasonable predictor of the

emissions reductions needed to reach the standard. The graph also displays estimates of the

reductions needed to reach the O. 12-ppm ozone standard, as a function of design value. The

two curves arching across the graph represent high and low estimates of the percentage

reduction in emissions that cities falling within a given design value range need attain the

slAutomotive Fleet 1987 Fact Book, Volume 26 Supplement, P.9, Bobit publishing co”> 1987”

Centrally owned fleet vehicles account for such a large fraction of VMT because each fleet

vehicle is driven over two-and-a-half times as many miles in a year as is averaged by the

general vehicle population.

Szcentrally-owned fleets turn over in about three years (the total vehicle Population takes more

than ten years to turn over), so we assume that fleet conversion would begin with all new

vehicles registered in fleets in 1991.

95
VOC EMISSIONS REDUCTIONS BETWEEN

1985 AND 1993: NO ADDITIONAL CONTROLS

% Reduction From 1985 Emission s

60%

40%

20%

I . ●

I

–20% t I I 1 I I I

0.12 0.14 0.16 0.18 0.20 0.22 0.2 4 0.26

1983–85 Design Value

Individua l

(ppm ozone)

City

Figure 3-11. Volatile Organic Compound (VOC) Emissions Reductions Between

1985 and 1993, Assuming No Change from 1985 VOC Regulations.

Each square represents a nonattainment city. The location on the graph shows the VOC emissions

reductions (as a percentage of 1985 levels) by 1993 given the State and EPA VOC regulations in place in

1985. Cities below the “O%” line experience a net increase in emissions between 1985 and 1993. The

horizontal axis shows the “design value”, a measure of peak ozone concentration used to determine the

emissions reductions needed to attain the ozone standard. The two curves arching across the graph and

vertical bars to the right of the curies show the upper and lower bounds of VOC reductions needed to attain

the standard. The vertical bars show estimated control requirements explicitly for major urban areas with

area-wide design values greater than 0.19 ppm.
standard. The area between these two curves represents a range of uncertainty in our

estimates of required emissions reductions. The five vertical bars to the right of the two

curves represent estimates of emissions reduction requirements for individual cities with

design values above 0.19 ppm. Areas with design values above 0.19 ppm have been excluded

from the graph because they are thought to be impacted significantly by transport from large

cities upwind. We have also omitted three cities with design values greater than 0.26 ppm

(all three are in southern California).

Summarizing how to read Figure 3-11, the squares show the change in VOC emission

in each nonattainment city projecled for 1993 (assuming existing regulations) and the curves

and vertical bars show the upper and lower bounds of the change needed, in each city, to

attain the ozone standard by 1993.

As Figure 3-11 illustrates, the change in VOC emissions that would occur by 1993

without further control ranges from an increase of about 10 percent to a reduction of about

15 percent. Emissions in most cities are expected to decline, due to the replacement of

today’s cars with lower- emitting new cars. However, emissions may increase in some cities

that are expected to experience high population growth.

Note that without additional controls only a few cities with design values of 0.13 ppm

may be able to attain the ozone standard by 1993. Most nonattainment areas will not be

much closer to meeting the standard than they are today.

With Additional Fuel Volatility Limitations and Onboard Controls

In the previous subsection, we analyzed the emissions reductions which would be

expected in 1993 if only State and federal regulations existing in 1985 were to be applied;

these estimates represent a “no-further-control” scenario from which we can gauge the

effectiveness of additional control measures. Recently, EPA announced proposals requiring

54 Because these limits on fuel volatility53 and Onboard controls on new motor vehicles .

controls could become law in the near future, their exclusion from a baseline “no-furthercontrol” scenario in a future year may not be appropriate. Therefore, the purpose of this

subsection is to show how the addition of these two control strategies would affect future

emissions reductions if they were added to the “no-further-control” baseline scenario.

Figures 3-12 and 3-13 illustrate the percent reductions which would be achieved in

1993 and 2003, respectively, from existing regulations plus fuel volatility and Onboard

controls (assuming these regulations are adopted in the near future). On average, in 1993,

5 352 Federa[ ~egister 31274 (Aug. 193 1987)

sAIbid., p. 31162.

97
80%

60%

40%

20%

0%

–20%

VOC EMISSIONS REDUCTIONS BETWEEN

1985 AND 1993: WITH ONBOARD AND

ADDITIONAL FUEL VOLATILITY CONTROLS

% Reduction From 1985 Emissions

0.12 0.14 0.16 0.18 0.2 0.22 0.24 0.26

1983–85 Design Value (ppm ozone)

.

individual Cit y

Figure 3-12. Volatile Organic Compound (VOC) Emissions Reductions Between

1985 and 1993, Including Onboard and Additional Fuel Volatility

Controls.

Each square represents a nonattainment city. The location on the graph shows the projected VOC

emissions reductions (as a percentage of 1985 levels) that each city can achieve by 1993 if Onboard

technology (to control motor vehicle gasoline refueling emissions) and fuel volatility limits are adopted in

addition to the State and EPA VOC regulations in place in 1985. Cities below the “O%” line experience a net

increase in emissions between 1985 and 1993. The horizontal axis shows the “design value", a measure of

peak ozone concentration used to determine the emissions reductions needed to attain the ozone standard.

The two curves arching across the graph and vertical bars to the right of the curves show the upper and

lower bounds of VOC reductions needed to attain the standard. The vertical bars show estimated control

requirements explicitly for major urban areas with area-wide design values greater than 0.19 ppm.

98
80%

60%

40%

20%

o%

–20%

VOC EMISSIONS REDUCTION BETWEEN 1985

AND 2003: EXISTING CONTROLS PLUS ONBOARD

AND ADDIITIONAL FUEL VOLATILITY CONTROLS

% Reduction From 1985 Emissions

High Estimate Reduction Target

I

I

.

.

●

.

●

. 8 m

● ●

.

9 9 ●

.

●

● m

●

1 1 1 I i I

o.12 0.14 0.16 0.18 0.2 0.22 0.24 0.26

1983–85 Design Value (ppm ozone)

●

Individual City

Figure 3-13. Volatile Organic Compound (VOC) Emissions Reductions Between

1985 and 2003, Including Onboard and Additional Fuel Volatility

Controls.

Each square represents a nonattainment city. The location on the graph shows the projected VOC

emissions reductions (as a percentage of 1985 levels) that each city can achieve by 2003 if Onboard

technology (to control motor vehicle Gasoline refueling emissions) and fuel volatility limits are adopted in

addition to the State and EPA VOC regulations in place in 1985. Cities below the “O%” line experience a net

increase in emmissions between 1985 and 2003. The horizontal axis shows the “design value”, a measure of

peak ozone concentration used to determine the emissions reductions needed to attain the ozone standard.

The two curves arching across the graph and vertical bars to the right of the curves show the upper and

Lower bounds of VOC reductions needed to attain the standard. The vertical bars show estimated control

requirements explicitly for major urban areas with area-wide design values greater than 0.19 ppm.
fuel volatility limits will lower emissions by about an additional six percent below 1985

levels; Onboard controls have only a minor effect in 1993 due to the small numbers of

Onboard-equipped vehicles which would be on the road. As illustrated in Figure 3-12, when

these control measures are added the percent reductions in many cities with design values of

0.13 ppm fall between the two curves. These cities may be able to attain the ozone standard

in 1993. By 2003, most cars and trucks will be equipped with Onboard controls. Even so,

Figure 3-13 shows that in 2003, the picture does not substantially improve compared to 1993,

primarily because of the influence of additional emissions due to population and economic

growth. Fuel volatility and Onboard controls, alone, are not expected to offset new

emissions growth in 2003.

With All Control Strategies Analyzed by OTA

Figure 3-14 illustrates the percent reduction in VOC emissions that could be achieved

by requiring all the control strategies listed in the beginning of this section. Emissions in

1993 would be lowered between about two and 40 percent, depending on the city. Figure 3-

15 shows that emissions reductions do not substantially change between 1993 and 2003. This

“flat” trend between 1993 and 2003 is due to the competing influences of population growth

(which drives new emissions growth) and the effects of additional emissions control

programs. The emissions reduction benefits from these programs act to cancel out new

emissions growth due to rising populations.

For some cities, the VOC emissions reductions from all controls may be more than

needed to attain the ozone standard. For other nonattainment cities with slightly higher

design values, the reductions projected for 1993 fall within the range of reductions which

might be needed. For most cities, however, projected reductions fall considerably below the

amount needed to meet the standard. The issues of excess, or overcontrol, and reduction

shortfalls (undercontrol) are discussed in the next subsection.

As stated earlier, the emissions reductions reported here represent control methods

that we know can be applied in the near term. We are able to analyze the emissions

reduction potential for about three-quarters of the VOC emissions inventory. The remaining

one-quarter represents mostly emissions from stationary sources for which we either could

not find applicable control methods or that we could not analyze because of a lack of

suitable information.

Estimates of Possible Excesses and Shortfalls in Emissions Reductions Required to Attain

the Ozone Standard

In this section we estimate: 1 ) the extent of overcontrol in nonattainment cities with

the lowest design values, and 2) the shortfall in nonattainment cities with higher design

values, expected to occur after applying all of the VOC controls discussed earlier. Table 3-9

100
80%

60%

4 0 %

20%

O%

–20 %

VOC EMISSIONS REDUCTIONS BETWEEN 1985

AND 1993: ALL MOBILE AND STATIONARY

SOURCE CONTROL STRATEGIES

% Reductions From 1985 Emissions

m

.

0.1 2 0 14 0.16 0.1 8 0.2 0.22 0.24 0 2 6

1983–85 Design Values (ppm ozone )

Individual City

Figure 3-14. Volatile Organic Compound (VOC) Emissions Reductions Between

1985 and 1993, Including All Mobile and Stationary Source

Control Strategies.

Each square represents a nonattalnment city. The location on the graph shows the projected VOC

emissions reductions (as a percentage of 1985 levels) that each city can achieve by 1993 if all additional

mobile and stationary source control strategies we analyzed are adopted in addition to the State and EPA VOC

regulations in place in 1985. The horizontal axis shows the “design value”, a measure of peak ozone

concentration used to determine the emissions reductions needed to attain the ozone standard. The two

curves arching across the graph and vertical bars to the right of the curves show the upper and lower bounds

of VOC reductions needed to attain the standard. The vertical bars show estimated control requirements

explicitly for major urban areas with area-wide design values greater than 0.19 ppm.

101
80%

60%

40%

20%

0%

–20%

VOC EMISSIONS REDUCTIONS BETWEEN 1985

AND 2003: ALL MOBILE AND STATIONARY

SOURCE CONTROL STRATEGIES

% Reductions From 1985 Emissions

High Estimate Reduction Target

II I

!

.

I

;

.

.

.

.

.

. ● .

.

9 9 ●

.

.

I 1 I I I I

0.12 0,14 0.16 0.18 0.2 0.22 0.24 0.26

1983–85 Design Values (ppm ozone)

Individual Cit y

Figure 3-15. Volatile Organic Compound (VOC) Emissions Reductions Between

1985 and 2003, Including All Mobile and Stationary Source

Control Strategies.

Each square represents a nonattainment city. The location on the graph shows the projected VOC

emissions reductions (as a percentage of 1985 levels) that each city can achieve by 2003 if all additional

mobile and stationary source control strategies we analyzed are adopted in addition to the State and EPA VOC

regulations in place in 1985. The horizontal axis shows the “design value”, a measure of peak ozone

concentration used to determine the emissions reductions needed to attain the ozone standard. The two

curves arching across the graph and vertical bars to the right of the curves show the upper and lower bounds

of VOC reductions needed to attain the standard. The vertical bars show estimated control requirements

explicitly for major urban areas with area-wide design values greater than 0.19 ppm.

102
Table 3-9. Estimates of Possible Overcontrol Resulting From All VOC

Control Strategies, in 1993

Possible Overcontro l

a

Nonattainment

Cities b y 1000 Tons/Yea r % of 1985 Emissions

Design Value 1985

Category Emissions Best Range Best Range

(ppm 03

) (1000 tons/year) Estimat e Estimat e

0.13-0.14 2,200 99 1-290 4 0-13

0.15-0.17 3,600 0 0-1 0 0

0.18-0.2 6 1,100 0 0

> 0.26 770 0 0

Totals 7,700 99 1-290 1.3 0-3.7

a Possible overcontrol represents the VOC emissions reductions in excess of the

total reductions needed to attain the ozone standard.

103
displays estimates of overcontrol from all VOC control strategies in 1993. We present a "best

estimate” as well as an uncertainty range for the four design value categories. To obtain

these estimates, we calculate the reductions in VOC emissions required to reach the ozone

standard in each city, assuming both VOC- and NOX

-rich conditions. (An earlier subsection

explains how the particular mix of pollutants in a city affects the reductions required to meet

the standard.) Because we do not have data on the pollutant mix in each city, we feel it is

important to present a range of uncertainty, in addition to the estimate one would expect if

all cities had the nationwide average mix of VOCs and NOX

.

Our best estimate is that adoption of all controls might over control VOC emissions in

low design-value nonattainment cities by about 100 thousand tons per year, or about four

percent of their 1985 emissions. The overcontrol possible in these cities ranges from zero to

290 thousand tons per year.

VOC reductions in attainment areas are a potentially significant source of overcontrol

in the sense that these areas do not need to reduce their emissions any further to meet the

ozone standard locally. We know that there will be some benefit to nonattainment cities

from controls in attainment areas, especially those in ozone transport regions, but we are not

able to estimate how much. Moreover, even in cities that already meet the standard,

lowering ozone concentrations even further will provide some benefit. Both S.1894 and

H.R.3054 explicitly mandate VOC controls in attainment areas in regions of the country

where transport of ozone and its precursors is a problem. Under S.1894, for example, VOC

emissions reductions in attainment areas in ozone transport regions could be about 570

thousand tons per year in 1993 (about a 16 percent decrease based on 1985 emissions) after

adoption of all applicable controls. 55 The total emissions reduction in all attainment areas

from application of the nationwide control measures discussed above is about one million

tons of VOCs per year, in 1993, or about nine percent, based on 1985 emissions. These

reductions result from controls on small VOC sources, limits on fuel volatility, Onboard

controls, and more stringent tailpipe standards for highway vehicles.

Table 3-10 presents our estimates of the additional VOC emissions reductions

nonattainment cities must achieve to attain the ozone standard after all controls have been

applied. Calculation procedures are similar to those discussed above. Our best estimate is

sswe assume that all VOC control strategies listed earlier, !2xceDt Stage 11 and new CTG’ss also

apply in attainment areas in regions of the country where ozone transport is a problem. Of the

570 thousand tons per year of VOC reductions, about 270 thousand tons are from RACT and

enhanced I/M programs; 300 thousand tons are from federal controls, fuel volatility limits, and

Onboard more stringent highway vehicle standards.

104
Table 3-10. Estimates of Possible Undercontrol Resulting From All VOC

Control Strategies, in 1993

Possible Undercontro l

a b

Nonattainment

Cities b y 1000 Tons/Year % of 1985 Emissions

Design Value 1985

Category Emissions Best Range Best Range

(ppm O3

) (1000 tons/year) Estimat e Estimat e

0.13-0.1 4 2,200 89 10-260 4 0-12

0.15-0.17 3,600 940 470-1,400 26 13-39

0.18-0.2 6 1,100 410 290-520 36 26-46

> 0.26 770 490 460-540 64 60-70

Totals 7,700 1,900 1,200-2,70 0 25 16-35

a Possible undercontrol represents the extra emissions reductions cities would nee d

to attai n

b Emission s

the ozone

reduction s

standard.

from use of methanol as a motor vehicle fuel are not included

in this analysis. Inclusion of this strategy in cities with design values greate r

than , or equal to, 0.18 ppm would decrease undercontrol (i.e., increase emissions

reductions) by about one percent.

105
that the shortfall of emissions reductions will be about 1.9 million tons per year in 1993, or

56 The shortfall in 1993 could be as low as about 25 percent of 1985 emissions in these areas.

1.2 million or as high as 2.7 million tons per year.

3.5 Costs of Control Strategies Analyzed by OTA

This section summarizes the costs of the control strategies analyzed by OTA. Because

we are unable to analyze the cost of additional emission controls required to make up the

shortfall discussed above, we are not able to estimate the total costs of actually attaining the

standard.

We estimate that the total cost of all controls analyzed by OTA in nonattainment

cities will be about $5.8 billion to $6.8 billion per year, in 1993. By 2003, costs will increase

to about $7.7 billion to $8.9 billion per year in nonattainment cities, primarily because of the

higher percentage of highway vehicles with more stringent controls. Table 3-11 displays the

costs in 1993, 1998, and 2003 by source category. Figure 3-16 displays the ranges of costs in

nonattainment cities in 1993 and 2003.

Table 3-12 presents the “cost-effectiveness” (the cost per ton of VOC eliminated) of

specific control measures for the three forecast years. Figure 3-17 illustrates the costeffectiveness of control measures in nonattainment cities in 1993. The solid bars represent

the average cost-effectiveness in all nonattainment cities. Uncertainty in the cost

effectiveness estimates is denoted by the thin horizontal lines. Note the wide range in

average cost-effectiveness across control measures, from about $500 per ton for limits on

fuel volatility to about $39,000 per ton for methanol fuels.

We also analyzed the cost and emissions reduction impacts of limiting the application

of controls on individual sources to those where the cost-effectiveness is equal to, or less

than, $5,000 per ton of VOCs reduced. We estimate that in 1993, by not requiring controls

that would cost more than $5,000 per ton, total costs in nonattainment cities would drop

about $1.6 billion per year, lowering total costs by about 26 to 31 percent. About 200

thousand tons per year of VOC emissions reductions would be lost in nonattainment cities,

lowering total reductions by about 12 percent. The declines occur entirely in the “RACTon-all-sources” and “New-CTGs” categories.

A brief discussion of the costs and cost-effectiveness of each of the control strategies,

including the data sources from which the estimates are calculated, follows.

561t is interesting to note that the magnitude of this shortfall (25 percent) is roughly equivalent

to the portion of the inventory that we are unable to analyze.

106
Table 3-11. Estimated Costs of Selected Control Strategies Analyzed by OTA

(costs in million dollars per year)a

199 3 199 8 200 3

Nonattain- Attainment Nonattain- Attainment Nonattain- Attainment

ment Cities Areas Total ment Cities Area s Total ment Cities Areas Total

RACT 1,600

New CTGs 300

Federal Controls 420

Onboard 90

Stage I I 190

Enhanced I/M (low)C 2,500

Fuel Volatility (low)d 94

New Highway Vehicle Standardse 250

Methanol Fuels 860

--b

.-

390

97

---

--

150

330

--

1,60 0

300

810

190

190

2,500

240

580

860

1,700

310

440

240

220

2,800

91

680

770

--

--

400

250

--

--

150

920

--

1,700

310

840

490

220

2,800

240

1,600

770

1,900

320

460

350

240

3,100

93

980

810

--

--

420

350

--

--

160

1,300

--

1,900

320

880

720

240

3,100

250

2,300

810

z TOTAL (low estimate) 5,800 910 6,800 6,800 1,700 8,400 7,700 2,200 10,000

+

TOTAL (high estimate) 6,800 1,000 7,800 7,800 1,800 9,600 8,900 2,300 11,000

a Totals are rounded.

b “--” means control strategy applied only in nonattainment cities.

c Includes costs of VOC, NOX, and carbon monoxide control.

d Estimates are equivalent annual costs. Controls required only five months out of the year.

e Includes costs of both VOC and NOX control.

Strategy Descriptions

RACT = “Reasonable Available Control Technology” on all existing stationary sources that emit more than 25 tons per year of VOC.

New CTG'S = new Control Technique Guidelines for existing stationary sources that emit more than 25 tons per year of VOC.

Federal Controls on selected small stationary sources of VOC (consumer and commercial solvents, and architectural surface coatings).

Onboard controls on motor vehicles to capture gasoline vapor during refueling.

Stage II control devices on gas pumps to capture gasoline vapor during motor vehicle refueling.

Fuel volatility controls which limit the rate of gasoline evaporation.

Enhanced inspection and maintenance (1/M) programs for cars and light-duty trucks.

New highway-vehicle emission standards for passenger cars and light-duty gasoline trucks.

Methanol fuels as a substitute for gasoline as a motor vehicle fuel.
Table 3-12.Estimated Cost-Effectiveness of Selected Control Strategies Analyzed by OTA

(dollars per ton of VOC reduced)

199 3 199 8 200 3

Nonattain- Attainment Nonattain- Attainment Nonattain- Attainment

ment Cities Areas Nationwide ment Cities Areas Nationwide ment Cities Areas Nationwide

RACT 2,900-7,200

New CTGs 5,000-7,300

Federal Controls 1,700

Onboard 1,100-1,300

Stage 11 1,000

Stage II & Onboard 1,200

Enhanced I/Mb

2,500-5,100

I Fuel Volatilityc

320-700

New Highway Vehicle Std’sb2,400

Methanol Fuels 39,000

-- a

--

1,700

1,100

--

1,100

--

320-700

2,400

--

--

--

1,700

1,100-1,300

--

1,200

--

320-700

2,400

--

3,000-7,300

5,100-7,300

1,700

1,200-1,400

1,000

1,700

3,200-6,400

320-700

2,400

39,000

--

--

1,700

1,200

--

1,200

--

320-700

2,400

--

--

--

1,700

1,200-1,400

--

1,500

-.

320-700

2,400

--

3,20 0

-

7,30 0

5,100-7,400

1,700

1,200-1,400

1,000

1,900

3,400-6,800

320-700

2,400

39,000

--

--

1,700

1,200

--

1,200

--

320-700

2,400

--

--

--

1,700

1,20 0

-

1,40 0

--

1,600

--

320-700

2,400

--

z

00 a "--" Means control strategy is applied only in nonattainment cities.

b Estimates reflect costs associated with VOC control onlY. Enhanced I/M controls also applies to NOX and carbon monoxide emissions;

new highway vehicle standards also apply to NOX emissions.

c Estimates reflect cost-effectiveness during the five-month summertime period when controls are required.

Strategy Descriptions

RACT = ‘Reasonable Available Control Technologyw on all existing stationary sources that emit more than 25 tons per year of VOC.

New CTG’s = new Control Technique Guidelines for existing stationary sources that emit more than 25 tons per year of VOC.

Federal Controls on selected small stationary sources of VOC (consumer and commercial solvents, and architectural surface coatings).

Onboard controls on motor vehicles to capture gasoline vapor during refueling.

Stage II control devices on gas pumps to capture Baseline vapor during motor vehicle refueling.

Fuel volatility controls which limit the rate of gasoline evaporation.

Enhanced inspection and maintenance (I/M) programs for cars and light-duty trucks.

New highway-vehicle emission standards for passenger cars and light-duty gasoline trucks.

Methanol fuels as a substitute for gasoline as a motor vehicle fuel.
ESTIMATED COST OF VOC EMISSION CONTROLS

IN 1993 AND 2003 IN NONATTAINMENT CITIES

RACT

* Fuel Volatility

Enhanced I/M

* Federal Controls

Stage II

Methanol Fuels

* Onboard Controls

New CTG’s

* New Mobile Std’s.

1993

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

Cost (billion dollars per year)

S Costs in attainment areas not shown.

Figure 3-16. Estimated Cost of Volatile Organic Compound (VOC) Emission

Control Strategies in 1993 and 2003 in Nonattainment Cities,

The cost of Enhanced Inspection and Maintenance (1/M) programs includes nitrogen oxide and carbon

monoxide control. The cost of New Mobile Standards includes nitrogen oxide control.

Strategy Descriptions

RACT = “Reasonably Available Control Technology” on all existing sources that emit ❑ ore than 25 tons per

year of VOC.

Fuel Volatility standards that limit the rate of gasoline evaporation.

Enhanced Inspection and Maintenance(I/M) programs for passenger cars and light-duty trucks.

Federal Controls on selected small stationary sources of VOC (consumer and commercial solvents, and

architectural surface coatings).

Stage II control devices on gas pumps to capture gasoline vapor during motor vehicle refueling.

Methanol Fuels as a substitute for gasoline as a motor vehicle fuel.

Onboard controls on motor vehicles to capture gasoline vapor during refueling.

New CTGs = new Control Technique Guidelines for existing stationary sources that emit more than 25 tons per

year of VOC.

New Mobil Standards = more stringent tailpipe emission standards for passenger cars and light-duty gasoline

trucks. 109
ESTIMATED COST–EFFECTIVENESS OF VOC

EMISSION CONTROL STRATEGIES IN 1993

IN NONATTAINMENT CITIES

RACT

Fuel Volatility

Enhanced I/M

Federal Controls

Stage II

Methanol Fuels

Onboard

New CTG’s

New Mobile Std’s.

Low Mean High o 1 2 3 4 5 6 7 8

($1000/ton of VOC reduced)

Figure 3-17. Estimated Cost-Effectiveness of Volatile Organic Compound (VOC)

Emission Control Strategies in 1993 in Nonattainment Cities.

The cost-effectiveness of Enhanced Inspection and Maintenance (1/M) programs and New Mobile

Standards include only the coat

The “?” attached to these lines

uncertainty associated with the

gasoline prices.

Strategy Descriptions

of VOC control. The thin horizontal lines represent ranges of uncertainty.

means that calculation of uncertainty was not possible. The very large

Methanol Fuels is due to the uncertainty of methanol prices relative to

RACT = “Reasonably Available Control Technology” on all existing sources that emit more than 25 tons per

year of VOC.

Fuel Volatility standards that limit the rate of gasoline evaporation.

Enhanced Impection and Maintenance(I/M) programs for passenger cars and light-duty trucks.

Federal Controls on selected small stationary sources of VOC (consumer and commercial solvents, and

architectural surface coatings).

Stage II control devices on gas pumps to capture Gasoline vapor during motor vehicle refueling.

Methanol Fuels as a substitute for gasoline as a motor vehicle fuel.

Onboard controls on motor vehicles to capture gasoline vapor during refueling.

CTGs = new Control

year of VOC.

Mobile Standards

trucks.

Technique Guidelines for existing stationary sources that emit more than 25 tons per

more stringent tailpipe emission standards for passenger cars and light-duty gasoline

110
Reasonably Available Control Technology ( RACT) on All Stationary Sources

Total costs in nonattainment cities for this category are predicted to be about $1.6

billion per year, in 1993, averaging about $2,900 to $7,200 per ton of VOC removed.

As mentioned in an earlier subsection, this control strategy applies to about 39 broad

source categories such as petroleum refining, certain types of chemical manufacturing, gas

stations, etc. A complete list, with our assumptions about control efficiencies and costeffectiveness for each source type, is included in Appendix A.

Adoption of New “Control Technique Guidelines” (CTG’s)

As stated earlier, we analyzed four stationary source categories currently being

considered as candidates for new CTG’s: wood furniture coating, plastic parts coating,

automobile refinishing, and coke-oven byproduct plants.

We estimate that new CTG’s would cost about $300 million per year in 1993, all of

which would be incurred in nonattainment cities. The cost-effectiveness averages about

$5,600 per ton with a range of $5,000 to $7,300 per ton. Appendix A lists the cost

assumptions used in our analysis.

Federal Controls on Small VOC Sources

The small amount of cost data available for architectural surface coatings revealed a

wide range of estimates, from a net savings to default costs of $2,000 per ton of reduction.

We assume that controls for this source cost about $1,000 per ton of VOC reduced. For

commercial and consumer solvents we assume a default cost of $2,000 per ton.

We estimate that, in 1993, federal controls on small VOC sources would cost about

$810 million per year, nationwide, with about $420 million per year incurred in

nonattainment cities. The average cost-effectiveness is estimated to be about $1,700 per ton

of VOC removed.

Controls on Gasoline Emissions From Vehicle Refueling

“Onboard” refueling controls on motor vehicles

We estimate the cost of Onboard controls by 1993 to be about $190 million per year,

nationwide, with about $90 million per year incurred in nonattainment cities. By 2003, costs

would total $720 million per year, nationwide, because of the higher percentage of On boardequipped vehicles on the road. The average nationwide cost-effectiveness is estimated to be

about $1,100 per ton in 1993.

111
For this analysis, we assume that all gasoline vehicles manufactured in 1991 and later

will be equipped with Onboard controls to capture gasoline vapors during refueling. By

2003, all gasoline vehicles on the road will be equipped with these controls. We assume that

Onboard controls cost about $25 per vehicle, which is close to EPA’s upper bound estimates’.

Note, however, that others conclude that the costs are higher. A study for the Motor Vehicle

Manufacturers Association estimates average per-vehicle costs of $80 for model-year 1991

vehicles .58

“Stage II” refueling vapor recovery

We estimate the cost of Stage II controls to be about $190 million per year in 1993,

all of which is incurred in nonattainment cities. This estimate is based on a costeffectiveness of $1,000 per ton of VOC removed. This figure represents EPA’s upper bound

range as presented in the recent gas-marketing regulatory impact analysis.59

Combined Stage II and Onboard controls

We assume that the cost of a combined Stage II and Onboard program is the sum of

the cost of each individual program. Therefore, in 1993, we estimate the cost to be about

$380 million per year, nationwide, with approximately $280 million per year incurred in

nonattainment cities. Nationwide costs increase to about $960 million per year in 2003. The

nationwide combined cost-effectiveness in 1993 is estimated to be about $1,200 per ton of

VOC removed and is expected to increase to about $1,600 per ton by 2003 because of fleet

turnover.

Enhanced Motor Vehicle Inspection and Maintenance (1/M) Programs

We estimate that enhanced I/M programs in nonattainment cities cost between about

$2.1 billion and $3.0 billion per year. In 2003, costs are expected to rise to between about

$2.6 billion and $3.7 billion per year. Assuming that one-third of the total costs are for

VOC reductions (the other two-thirds for NOX and carbon monoxide), the cost-effectiveness

in 1993 is estimated to be between $2,500 and $5,100 per ton of VOC reduced. In 2003, the

cost-effectiveness will increase to between $3,400 to $6,800 per ton; this rise is due to the

fact that cars and trucks will be cleaner in 2003, thus lowering the emission reduction

potential of enhanced I/M programs.

57U.S. Environmental Protection Agency, op.cit., footnote 41, p. 2-51

s8Multinational Business ServiCeS, Inc., “Costs and Cost-Effectiveness of Stage 11 and Onboard

Refueling Vapor Controls,” prepared for the Motor Vehicle Manufacturers Association of the

United States, Inc., and the Automobile Importers of America, Inc., April 1987, p. 4-14.

sgu s Environmental Protection Agency, oP.cit., footnote 41 ‘

. .

112
Our estimates of enhanced I/M program costs are based on an analysis of the

California I/M program, prepared for the California Air Resources Board by Sierra Research,

Inc. 60 We use Sierra Research’s finding that an enhanced I/M Program costs about $50 Per

.

vehicle. About $20 of this cost is for the inspection fee and program administration. The

remainder is for repair costs, which we assume to range between $70 and $100 per vehicle

for one-third of the vehicles inspected. Sierra Research’s analysis concludes that an

enhanced I/M program can reduce VOC emissions from cars and light-duty trucks by about

30 percent. This is about 17 percent higher than current I/M programs. For those cities that

already have an I/M program in place, we credit $20 per vehicle as the cost of the existing

program.

61 The major difference seems These costs are quite a bit higher than EPA estimates.

to be assumptions about whether repair costs drop after the program has been operating a

few years.

More stringent Highway -Vehicle Emission Standards

We estimate that the total cost of tighter emission standards for highway vehicles in

1993 will be about !$580 million per year, nationwide, of which about $250 million per year

will be incurred in nonattainment cities. By 2003, costs will total about $2.3 billion per year,

nationwide, because a higher percentage of vehicles on the road will be equipped with new

controls. These totals include the costs attributed to both VOC and NOX control on new

passengers cars and light-duty gasoline trucks. Costs are based on an OTA contractor report

by Sierra Research, inc. ( 1988), that estimated new emission control costs of about $140 per

62 Reductions of VOC are estimated to cost vehicle for combined VOC and NOX control.

about $2,400 per ton of VOC reduced. (The cost-effectiveness of combined VOC and NOX

control is about $9,200 per ton of VOC and NOX reduced. ) As described earlier, we

analyzed more stringent standards that can be met after 50,000 miles of driving under

controlled conditions for cars, and 120,000 miles for light-duty trucks; tailpipe VOC

emissions may exceed these standards after 50,000 miles (for cars) and 120,000 miles (for

trucks) of actual use by individual vehicle owners.

Limits on Fuel Volatility

We estimate that reducing fuel volatility (i.e., the rate of evaporation) during the

five-month summertime period costs between about $150 million and $340 million per year

‘“Sierra Research, Inc., op. cit., footnote 44.

Glphil Lorang , u s Environmental Protection Agency, Off iCe of Mobile Sources,

. . “Further OMS

Reflections on the Cost of Mobile source Provisions of the Mitcheil Bill,” September 10, ] 987,

Gzsierra Research, Inc., Op. cit., footnote 44”

113
nationwide. The cost-effectiveness, as estimated by EPA, ranges between about $320 to $700

per ton of VOC reduced.63

Alternative Motor Vehicle Fuels: Methanol

Because methanol is incompatible with some metals and polymers currently used in

automotive fuel systems, straight methanol is not recommended for use in vehicles designed

to run on gasoline. However, methanol-fueled vehicles have been built in limited runs and

are currently being test driven in California. Automobile manufacturers estimate that in runs

of less than about 150,000 vehicles, passenger vehicles designed to operate on methanol

64 

would cost $500 to $1,000 more per vehicle than gasoline-fueled vehicles. Assuming that

using methanol is equivalent to reducing total VOC emissions by 50 percent, compared to a

new gasoline-fueled vehicle with refueling controls in place, and that methanol-fueled

vehicles cost $500 to $1000 more than comparable gasoline-fueled vehicles, the costs

associated with a methanol strategy would be roughly $10,000 to $20,000 per ton of VOC

removed

6s

, not considering fuel costs. However, in large runs, others expect the costs of

producing gasoline and methanol-fueled vehicles to be comparable, so that considering

vehicle costs alone, the cost per ton of VOCs removed would be negligible.66

Based on estimates of the retail cost of methanol ($0.84 per gallon67) and the 1987

average retail price of gasoline ($0.96 per gallon68), and assuming that gasoline mileage is 1.8

times better than that of methanol, we estimate that fuel costs for operating motor vehicles

on methanol would be about 50 percent higher than operating them on gasoline: 5.7 cents per

mile for methanol versus 3.6 cents per mile for gasoline. Retail gasoline prices would have

to rise above about $1.50 per gallon with no change from current prices for methanol in

G3u s Environmental protection Agency, op. cit., footnote 48, PPs. 6-26, 6-28” . .

64’’Cost and Cost Effectiveness of Alternative Fuels,” prepared for the Vice President’s Task

Force, July 1987.

GsAssuming new gasoline-fueled vehicles emit 0“95 g/mi661bid.

GTBased on current wholesale methanol costs of $0.60 per gallon (A Icohol UPdate~ Information

Resources, Inc., Washington DC, April 11, 1988), and $0.24 per gallon for taxes, distribution

and markup.

GsMonthly Energy Review, U.S. I)epartrnent of Energy, DoE/EIA-oo35 (87/ 10)> ‘ash i ng t o

n

DC, October, 1987, p. 96.

114
order

—

for gasoline and methanol fuel costs to be equal. 69 Again assuming that methanol ‘se

is equivalent to reducing VOC emissions by 50 percent, the existing difference in fuel prices

would result in emission reduction costs of about $39,000 per ton of VOC removed, above

vehicle costs .’” Based on this cost effectiveness estimate, the total cost of a strategy in

which centrally owned light-duty vehicles in areas with design values of 0.18 ppm or higher

would be required to operate on methanol is estimated to be $860 million, in 1993. Finally,

note that the cost effectiveness of methanol use is highly sensitive to the relative prices of

methanol and gasoline. If retail methanol prices were ten cents lower than assumed above,

for example, the estimated cost per ton of VOC removed would be reduced by one third, to

about $26,000.

GgThe amount of methanol required to operate centrally owned fleets of 10 or more light duty

vehicles year round in all areas with design values of 0.18 ppm or higher is estimated to be

about 2.8 billion gallons per year. This level of methanol consumption is more than twice

current U.S. production. Moreover, existing methanol production capacity worldwide is

insufficient to meet this demand. Because new facilities for methanol production are unlikely

to be profitable if methanol prices drop much below current levels, significantly lower methanol

prices are not expected in the future.

TOfn estimating cost effectiveness it is assumed that a gasoline-fueled Vehkle would get 27 mi~es

per gallon, and emit a total of 0.95 grams VOc per mile.

115
4. OZONE AND THE CLEAN AIR ACT

The goal of the Clean Air

air resources. ” To implement that

to establish National Ambient Air

Act is to “protect and enhance the quality of the Nation’s

goal, the 1970 Clean Air Act Amendments required EPA

Quality Standards (NAAQS) to define the level of air

quality that is expected to be maintained throughout the nation. Of the six “criteria”

pollutants for which standards have been established, we have been least successful in our

efforts to attain the standard for ozone. Nationwide, more than sixty areas still violate the

ozone standard.

The ozone nonattainment problem is addressed by bills in both houses of Congress, as

well as by a new regulatory policy that has been proposed by EPA. In this chapter, we first

review the framework for meeting the ozone standard that was established in the 1970 and

1977 Clean Air Act Amendments and then briefly discuss the State implementation planning

(SIP) process. The last section presents some of the reasons why efforts to meet the standard

following the 1977 Amendments failed.

4.1 Evolution of Ozone Control Under the Clean Air Act:

The 1970 and 1977 Clean Air Act Amendments established a partnership between the

States and the Federal Government. EPA sets nationally uniform air quality standards and

the States, with the Agency’s assistance, are responsible for meeting them. The requirement

that the States develop “State Implementation Plans” (SIPS) and submit them to EPA for

review allows for federal oversight of the States’ efforts to achieve and maintain the required

level of air quality. In addition to the SIP process, the 1970 Clean Air Act Amendments

established two mandatory control programs, one applying to new motor vehicles and the

other to new stationary sources. EPA is responsible for setting standards for new motor

vehicles. EPA also issues regulations for new stationary sources, but the program is

implemented by the States. The 1977 Amendments added three additional control programs,

requiring ozone and carbon monoxide nonattainment areas to apply retrofit controls on

existing stationary sources and more stringent emissions limits on new stationary sources, and

to develop motor vehicle inspection and maintenance programs.

IThe six ~~criteria” po~]utants for which EPA h~$ been expl~cit~y required to establish ~AAQ~

are ozone, lead, sulfur dioxide, particulate, nitrogen dioxide, and carbon monoxide.

117
As defined in the Clean Air Act, “primary” air quality standards represent the

maximum allowable concentration of each criteria pollutant that protects against adverse

health effects. The primary standards are required to be set at a level that “protects the

public health” with an “adequate margin of safety,” without regard to the economic or

technical feasibility of attainment. Secondary standards are established to protect against

adverse impacts on human comfort and welfare, including impacts on visibility, vegetation,

animals, wildlife, materials and property. The States, together with EPA, are responsible for

ensuring that the primary air quality standards are met “as expeditiously as practicable”,

within the deadlines specified in the Act. The secondary standards are to be attained in a

“reasonable” period of time.

Primary and secondary standards for oxidants 2 were first set by EPA in 1971. In

1979, EPA revised the standards to the current definition. Both the primary and secondary

standards for ozone are currently defined as a daily maximum, one-hour average

concentration of 0.12 ppm, not to be exceeded more than once per year, on average.

In the Clean Air Act Amendments of 1970, Congress set 1975 as the deadline for

meeting the primary air quality standards. The States were required to develop and carry out

State Implementation Plans (SIPS), estimating the emissions reductions required to attain the

NAAQS, and establishing control programs to achieve the required reductions. In addition,

EPA was required to develop New Source Performance Standards (NSPS) that would be

imposed on new or modified stationary sources with the potential to emit more than 100 tons

per year of any of the criteria pollutants or of volatile organic compounds (VOCs), one of

the two principal precursors of ozone. To enforce the NSPS, the States were required to

include construction permit programs in their SIPS. EPA was also required to enforce a

specified schedule for reducing emissions from motor vehicles.

By 1977, two years after the original deadline, 78 areas were still violating the ozone

standard then in place (no more than one exceedance per year of a one-hour average oxidant

concentration of 0.08 ppm). The widespread failure to attain the ozone standard by 1977 has

been attributed to the fact that mobile source emissions reductions that the States and EPA

were counting on to reduce ozone were not fully realized3

, and that few controls were

required on existing stationary sources of VOCs4. Due to waivers granted by the EPA

Administrator and an extension given by Congress, the schedule specified in the Clean Air

Zphotochemical oxidants are a gl-oup of chemically-related pOllUtZiIltS. From the standpoint o f

health and welfare effects, ozone is the most important of these pollutants. Ozone typically

comprises over 90 percent of the total mass of photochemical oxidants measured in urban air

3

Stewart, R.B, and Krier, J. E., Environmental Law and Policy, 2nd Edition (Bobbs-Merrill

Company, inc., Indianapolis, IFJ, 1978).

AHawkins, Do, personal communication, ‘arch 1988”

118
Act for tightening motor vehicle emissions limits had not been met. For example, while new

car VOC emissions rates were about 60 percent lower in 1977 than in 1970, according to the

schedule specified in the Act, a 90 percent reduction should have been achieved.

Transportation control measures such as gas rationing, restricted parking and restricted

freeway lanes generally met with strong resistance; and in 1974 Congress enacted legislation

that prohibited EPA from requiring many types of transportation control measures.

In 1977, the deadline for meeting the ozone standard was moved back to 1982.

Severe nonattainment areas that did not expect to be able to meet the 1982 deadline could

obtain an extension to 1987. Responding to the failure to meet the goals of the 1970 Clean

Air Act, the 1977 Amendments included anew and more aggressive control program. New

SIPS were to be developed and submitted to EPA in 1979, and again in 1982, for areas

seeking extensions of the attainment deadline to 1987. A new schedule was established for

imposing emissions limits for new motor vehicles. Existing stationary sources in

nonattainment areas would have to be retrofit with emissions controls. A new source could

only be constructed in a nonattainment area if it would operate at the “lowest achievable

emissions rate” and if emissions reductions could be obtained from other sources to offset the

emissions from the proposed source. Transportation control measures would have to be

considered. Severe nonattainment areas would have to implement automobile inspection and

maintenance programs.

By 1983, 17 areas that had not asked for extensions to 1987 were still violating the

ozone standard (which had by that time been revised to its current definition, a daily peak

one-hour average concentration of 0.12 ppm not to be exceeded more than once per year, on

average). Following its interpretation of the Act, EPA proposed to ban construction of

major stationary sources in these areas. However, Congress then prohibited the Agency from

using appropriated funds to impose construction moratoriums in areas with approved SIPS.

Consequently, the areas that had not met the 1982 deadline were simply required to submit

revised SIPS demonstrating how they would attain the standard by 1987. As of November,

1987, no final action had been taken to approve or disapprove any of these SIPS. Since 1983,

the Agency’s policy on sanctions has been to restrict their imposition to areas with deficient

SIPS or areas that have failed to carry out their SIP commitments in good faith.

In addition to the 17 areas that were supposed to meet the 1982 deadline but failed to

do so, approximately forty ozone nonattainment areas had obtained deadline extensions prior

to 1982. These areas were to have submitted SIPS in 1982 that would demonstrate attainment

by 1987. EPA promulgated approvals and disapprovals for most of these SIPS in 1983 or

1984. Sanctions were imposed in some areas to spur correction of SIP deficiencies. In July

of 1987, EPA proposed construction bans for 11 ozone nonattainment areas that still did not

have adequate SIPS.

119
Some progress has been made since 1977 in reducing emissions of VOCs, one of the

two principal sets of precursors of ozone. Nationwide, estimated emissions of VOCs have

decreased by about 10 percent over the last decade. The decline in VOC emissions is due

primarily to a 30 percent decline in mobile source emissions, which has occurred because of

significant reductions in vehicle emissions rates, despite a 25 percent increase in vehicle

miles traveled .

5 Stationary source VOC emissions have increased by

1977.

Emissions of nitrogen oxides (NOX, the other principal set

estimated to have declined by less than two percent.6

Despite the progress that has been made in reducing VOC

areas still violate the current ozone standard. In November, EPA

policy for addressing ozone and carbon monoxide nonattainment.

of

about 3 percent since

precursors of ozone) are

emissions, more than 60

proposed a “post- 1987”

Then, on December 11,

1987, Congress extended the deadline for attainment once again, this time to August, 1988.

The legislation precluded the imposition of the construction bans EPA had proposed in July.

4.2 State Implementation Plan (SIP) Development and

Implementation

The principal regulatory mechanism by which the air quality standards are to be met

and maintained is the State-level process of developing and implementing State

Implementation Plans (SIPS). Through the SIP process, the States determine the emissions

reductions required to meet the air quality standard and then set up programs to achieve the

required reductions. EPA is responsible for reviewing the SIPS to ensure that they will lead

to attainment, and also provides guidance to the States on several aspects of SIP development.

In addition to deadlines for attainment of the standards, Congress has also specified deadlines

for SIP development.

Developing and implementing a State Implementation Plan for ozone involves a series

of steps that are carried out primarily at the State and local levels.

1 ) First, the extent and severity of the local air quality problem is determined by

monitoring ambient ozone concentrations. An area is classified “nonattainment” for

ozone if peak one-hour average concentrations measured at any monitor exceed

0.12 ppm more than one day per year, averaged over three years.

su s Environmental protection Agency, National Air Quality and Emissions Trends RePort>

1985: EPA-450/4-87-00 1 (Research Triangle Park, NC, 1987), pp. 3-32, 3-35.

GIbidQ, p. 3-29.

120
2) A critical piece of information required to develop a strategy for meeting the

ozone standard is an inventory of VOC and NOX emissions that covers both

stationary and mobile sources. The first step is to estimate current emissions of

both precursors. The second is to forecast the changes in emissions that are

anticipated to occur in the future without additional local control efforts. Such

changes include increases or decreases due to anticipated changes in population,

motor vehicle use and industrial activity, and also reductions due to control

programs which will be implemented at the federal level.

3) The next step is to use a mathematical model to predict how much emissions will

have to be reduced (in addition to the reductions that will be achieved through

federally-implemented control programs) to meet the ozone standard by the

Congressionally-specified deadline. The predicted control requirement becomes

the emissions reduction target for the area.

4) The three preceding steps are technically challenging. The fourth step is difficult

not only from a technical standpoint, but also from a political standpoint. Each

nonattainment area must develop a control strategy that allocates the required

emissions reductions among sources in the area, and then design programs to carry

out the strategy. A control strategy typically includes imposition of emission limits

or control technology requirements on stationary sources, with permitting and

source inspection and monitoring programs to ensure compliance. Control

strategies may include measures to encourage people to cut back on driving.

Retrofit controls on some categories of stationary sources, new source construction

permitting programs and motor vehicle inspection and maintenance programs have

been specified by Congress as mandatory components of SIP control strategies for

ozone.

5) Once an ozone control strategy has been developed, the regulations contained in

the SIP must be approved through the State regulatory process, and in some cases,

by the State legislature. This step alone can be time consuming. State rulemaking

processes typically take from six to eleven months’.

6) Once a SIP has been approved at the State level, it is sent to EPA for review. The

Agency ensures that the SIP has made the required “attainment demonstration”, i.e.

that the control measures the State has committed to implementing will provide the

level of emissions reductions predicted to be required to meet the standard. The

Agency also ensures that the SIP includes all of the control programs that Congress

7 pacifi c Environmental Services, Inc., Study of the 1979 State Implementation plan Submittals

(prepared for the National Commission on Air Quality, Washington, D. C., December 1980), pp.

4-13, 4-14.

121
requires. If the States are delinquent in their submittals or submit deficient

the Agency is required to impose specified sanctions and may impose others

discretion.

SIPS,

at its

7) The first six steps can be regarded as SIP development. What remains is to carry

out the regulatory programs contained in the SIP. This includes operating

inspection, monitoring, and enforcement programs for both stationary and mobile

sources. As SIP implementation progresses, the impact of the SIP is assessed by

tracking emissions, and ultimately through monitoring ambient ozone

concentrations.

8) Finally, the control strategy is revised, if necessary, to resolve problems identified

by EPA during its review process, or to compensate for inaccurate predictions of

emissions trends or of the efficacy of control measures, or, finally, if the ozone

standard is not attained.

EPA participates in SIP development by providing guidance to the States on

monitoring, emissions inventory development, modeling, and on the cost and reduction

potential of alternative control measures. Most States rely heavily on EPA as a source of this

information. For ozone, the “control technology guidelines” (CTGs) issued by EPA on

retrofit control strategies for existing sources of VOCs have been particularly critical. States

have not only relied on the CTGs to help identify potential VOC control measures but also to

facilitate promulgation of State-level regulations. For example, the existence of a CTG for a

particular source can provide leverage in convincing State legislators that the source ought to

be controlled.

EPA is responsible for reviewing the SIPS to ensure that they will lead to attainment

by the specified deadline and that they contain the required control programs. This process

involves repeated interaction between EPA, its Regional offices, and the States.

4.3 Failure to Meet the Ozone Standard Following the 1977

Amendments

More than ten years have now gone by since the passage of the last major set of

amendments to the Clean Air Act, which called for a new and more aggressive control

program to attain the ozone standard throughout the country by 1987. While ozone

concentrations have been lowered in many nonattainment areas, more than 60 areas still

exceed the standard. OTA sponsored two workshops involving State and local air pollution

control agency officials and current and former EPA staff, respectively, to explore the

reasons why this decade-long effort has not resulted in more areas attaining the standard.

122
Before each of the workshops, participants were asked to complete a questionnaire

that suggested possible problems associated with the development and implementation of the

ozone control strategy pursued since the late 1970s. The

the basis for further discussion.

Participants at each workshop tended to agree on

most significant. However, the problems emphasized by

results of the questionnaires formed

a few problems that they saw as

EPA and State regulators were quite

different. State and local respondents emphasized the problems of transport of ozone and

ozone precursors, inadequate air quality models, States’ inability to promulgate regulations

without EPA support, and inadequate EPA performance. EPA respondents most often cited

emissions growth, inaccurate emissions inventories, unreasonable deadlines in the Act, and

“lack of political will” to solve the ozone problem.

Many of the key problems identified in the OTA workshops were similar to those

discussed in a recent GAO report. 8 The GAO investigators also identified problems

stemming from inaccurate emissions inventories, flawed modeling, and ineffective EPA

oversight. In addition, they found that some control measures planned by States were not

implemented or were poorly enforced.

In this section, we will summarize the reasons for continued nonattainment most often

suggested by participants in the OTA workshops and in the GAO report. Our discussion

begins with “planning” problems, such as inadequate inventories and poor modeling, and

continues with the more difficult administrative and political problems, such as the slow pace

of issuing control regulations and poor control over emissions growth.

Incomplete And Inadequate Emissions Inventories

An early and extremely important step in developing an ozone control strategy is to

estimate current emissions of ozone precursors and to project future emissions in the absence

of additional controls. Both EPA and State participants at the OTA workshops suggested that

incomplete or inaccurate emissions inventories were a very serious problem. Respondents

were particularly concerned that emissions projections made in the past have been too low,

thus leading to underestimation of the reductions needed to ensure attainment by 1987. State

respondents emphasized that when current SIPS were developed, regulators did not anticipate

the gradual increase in gasoline volatility and hence evaporative emissions that has since

occurred. EPA participants stressed that in many areas, growth in automobile use has been

much higher than originally expected, and as a result automobile emissions have exceeded

expectations.

8United States General Accounting office, 1988, “Air pOllutiOn: OZOne Attainment Requires

Long-Term Solutions to Solve Complex Problems”. GAO/RCED-88-40, 61 pp.

123
The GAO investigators agreed that the ozone plans they reviewed often understated

VOC emissions. For example, they found that “the plan for the Los Angeles area estimated

that vehicle mileage would increase 14 percent for the planning period, but the mileage

actually increased during the 1979 to 1985 period by 26 percent.”9

Underestimates Of The Extent Of Control Required To Attain The Standard

The next step in devising a control strategy is to estimate the extent of emissions

reductions necessary. Ozone is formed by a complex series of reactions involving volatile

organic compounds (VOCs) and nitrogen oxides (NOx) in the presence of sunlight. In order

to control ozone formation, one must decide how much to reduce emissions of VOCs or NOX,

or both. To do so, regulators have relied on atmospheric models that describe the

relationship between VOC and NOx emissions and ambient ozone levels. Since each

nonattainment area is unique due to a different mix of sources and different meteorological

conditions, relying on computer models to predict control requirements allowed regulators to

tailor control programs to each area’s local circumstances.

State and local participants at the OTA workshops suggested that inaccuracy and

misuse of atmospheric models were among the most significant problems that contributed to

continued nonattainment. They suggested that, due to incomplete scientific understanding of

ozone formation, available atmospheric models were (and still are) too inaccurate to derive

accurate estimates of the emissions reductions needed to ensure attainment. State participants

suggested that state-of-the-art models, which they believe are accurate to within 30 percent

at best, are not sufficient to ensure compliance with a standard that allows only three

exceedences over a three-year period.

State participants suggested that a second problem with models was that delegation of

responsibility for applying models to the States provided them with ample opportunities to

cheat in developing their implementation plans, a practice known as “gaming”. States were

able to choose favorable model assumptions and inputs to arrive at the least stringent

predictions of emission reduction requirements.

Many State participants were also concerned that available models do not adequately

account for transport of ozone and its precursors. Finally, State workshop participants

questioned whether NOX emission reductions may have been needed in addition to the VOC

reductions, which EPA has exclusively encouraged.

‘Ibid., p.29

124
In contrast to State and local workshop participants, EPA participants were relatively

comfortable with available air quality models. They suggested that uncertainties in modeling

are no greater than the uncertainties associated with many other steps of devising and

enforcing an ozone control strategy. EPA respondents were also much less concerned than

their State and local counterparts with whether NOX reductions were needed, although they

did suggest that NOX controls might be beneficial in a few areas. However, some EPA

participants, like their State counterparts, were concerned that available models do not

adequately account for transport.

The GAO investigators pointed out the problems that resulted from the use of

modeling with incorrect or inadequate data when preparing SIPS. For example, they pointed

out that Houston’s 1982 SIP indicated that they needed a 41 percent reduction to attain the

standard, but that the analysis relied on some poor quality atmospheric data. When the same

analysis was performed by EPA with more accurate data, a 71 percent reduction was

predicted to be required. 10

States Had Difficult Issuing Stationary Source Relations

Once the magnitude of overall reductions needed has been established, State

regulators must decide which sources or source categories will be required to lower emissions,

and by how much. EPA provides States with technical guidance concerning the availability

and cost of various control measures for new and existing sources. For 29 categories of

existing sources of VOCs, the agency issued Control Technique Guidelines (CTGs) that

presumptively define the level of controls that EPA considers “reasonably available” (the level

of control required for existing sources under the Act). The actual regulations limiting

emissions from both new and existing sources were issued by the States. States were required

to include regulations corresponding to the CTGs in their SIPS, plus any additional

regulations needed to achieve the standard.

State workshop participants pointed out that in many cases reductions due to CTGs

alone were not sufficient to attain the standard. They argued that they were unable to

promulgate the additional regulations necessary to achieve the requisite VOC emission

reductions. First, they suggested that many State regulators face legislative prohibitions or

political pressure not to adopt particular control measures unless they are clearly forced to do

so by EPA. Second, they suggested that State agencies often do not have the resources or

technical expertise needed to develop new regulations on their own. State participants

complained that EPA stopped issuing CTGs in recent years, leaving them without a clear

1°1bid., p.35

125
federal directive to issue particular regulations and without the resources to develop their

own regulations. They also argued that it is more resource efficient for EPA to develop

regulations or CTGs once than for each State to duplicate the activity.

In their own defense, some EPA participants suggested that the agency stopped

issuing CTGs in the face of OMB resistance. One participant suggested that after OMB

reviewed them, the most recent group of CTGs were “so watered down that it may have been

better not to issue them.” Other EPA participants argued that budget limitations were much

more significant than OMB review.

The GAO report provides some specific examples of areas that did not implement all

of the measures they needed to attain the standard. The report states that in Los Angeles,

about half of the stationary source control measures committed to in their SIP were not

implemented as of 1986. GAO concludes that “in general, the measures had not been

implemented either because the control technology was not fully developed or the local air

quality board considered the measures too costly given the expected reductions.”11

Poor Control Over Emissions Growth

In order to meet the air quality standard, nonattainment areas needed to both reduce

existing emissions and ensure that new sources of emissions were offset by additional

reductions from existing sources. EPA respondents most often cited emissions growth as the

most important reason for the widespread failure to attain the ozone standard. As suggested

above, growth in automobile use was seen as particularly problematic. Although many areas

experienced a net decrease in mobile source emissions as a result of more stringent tailpipe

emission standards, the reductions were often less than anticipated due to higher than

expected automobile use. Workshop participants also stressed that the increasing number of

automobiles will eventually reverse the downward trend in mobile source emissions

nationwide unless more stringent tailpipe standards are adopted.

EPA respondents were sharply divided over the effectiveness of regulatory measures

intended to offset new stationary source emissions. Only “major” new sources, those that

emit more than 100 tons per year, have been subject to new source review, which requires

them to obtain emissions reductions from existing sources to offset their emissions, and to

install the most stringent control technology available. New sources larger than 100 tons per

year can avoid new source review by obtaining offsetting reductions to limit the net

emissions increase to less than that of a “major” source, a practice called “netting”. About

llIbid., p.25

126
half of EPA respondents felt that too many sources have been exempt from new source

review. However, others suggested that current new source review adequately counteracts

emissions growth or results in only insignificant emissions increases.

Most State and local workshop participants were dissatisfied with new stationary

source controls. They distrust emissions trading, since they feel that most emissions

reductions used in “netting” or offsets would have occurred anyway. State participants

argued that such reductions should have been “credited toward cleaner air” rather than used

to facilitate new emissions.

Inability To Control “Transported” Ozone and Precursors

State and local participants complained about the difficulty of achieving adequate

emissions reductions when the geographic characteristics of the problem do not correspond to

State boundaries. State and local respondents suggested that many nonattainment areas

monitor high levels of ozone precursors and even nonattainment levels of ozone in air masses

entering their areas. They argued that emissions in upwind attainment and nonattainment

areas contribute significantly to some cities’ air quality problems and to elevated ozone levels

in rural areas. EPA respondents also ranked transport as a serious problem, although they

did not rank it as highly as did State respondents.

Lack of Leadership and Political Will To Solve the Problem

State and local workshop participants complained that EPA has not demonstrated

sufficient leadership and commitment to solve the problem. They suggested that EPA

“dragged its feet” on decisions to issue federal regulations for fuel volatility, automobile

refueling emission controls, and more stringent tailpipe standards. Participants suggested that

EPA’s indecision discouraged States from developing their own regulations for those

particular sources or for other categories that would deliver small benefits in comparison. AS

discussed above, the States argued that they were often unable to promulgate additional

stationary source regulations because EPA stopped issuing CTGs.

In response to these criticisms, EPA respondents suggested several areas in which the

States did not require the measures that they should have, citing inadequate automobile

inspection and maintenance programs and incomplete SIP implementation as examples.

Although they acknowledged that some federal regulations have been delayed, most EPA

respondents suggested that earlier issuance of those regulations would not have had a large

effect on the overall nonattainment problem.

The GAO report concluded that both State implementation and enforcement of

control programs and EPA oversight have not been as effective as they should have been.

From their discussions with State and local officials, the GAO investigators Concluded that at

127
the local level there has been “a general reluctance to implement control measures that will

have a negative impact on economic development or change life-styles.” 12 Agreeing with

comments made by EPA participants at our workshops, GAO pointed out a number of

specific examples of weak implementation, inspection, and enforcement at the State and local

level.

Although the Act delegates primary responsibility for developing SIPS and

promulgating the necessary regulations to the States, EPA is responsible for reviewing SIPS

and overseeing their implementation. The GAO report was critical of EPA’s oversight role.

In two of the three urban areas they studied, EPA did not enforce requirements that the

States stick to their declared schedules of annual emissions reductions. All three areas had

problems with their SIPS. Even though EPA was aware of deficiencies, it did not call for

SIP revisions in two of the areas and waited until July 1987 to disapprove the SIP submitted

by the third area.

EPA participants at our workshops agreed with many of the criticisms of EPA’s

performance, but stated that they faced serious constraints on their ability to administer the

Act. Questionnaire respondents cited inadequate budgets, OMB interference, and lack of

political support. Some suggested that there was never really the “political will” to take the

steps necessary to solve the ozone problem. Although many EPA participants cited “lack of

political will” as a problem, they disagreed over whose will was lacking. Some suggested that

there was an implicit understanding between the States and EPA not to push for more

aggressive control measures since they felt that they had reached the limits of public

acceptability. Others suggested that past efforts were not at all aggressive; administrative

will, not public support, was lacking. Some argued that the change in Administration in

1981 lead to weaker EPA implementation of the Clean Air Act.

Unreasonable Deadlines

Finally, many EPA respondents suggested that the deadlines Congress specified in the

1977 Amendments were simply unreasonable. They argued that widespread failure to attain

the standard by December 31, 1987 does not reflect insufficient progress as much as

unrealistic expectations. While some suggested that the deadline was only unreasonable for

Los Angeles, others felt that it was unrealistic for many areas. Participants at both

workshops argued that unreasonable deadlines were counterproductive. They suggested that

overly stringent deadlines encouraged States to cheat on their SIPS and EPA to play along

with them.

1

2

1 bid., p. 27

128
5. PROPOSALS FOR CHANGE:

S.1894, H.R.3054, AND EPA’S PROPOSAL

The leading proposals that address the ozone nonattainment problem include: 1)

S. 1894, a comprehensive set of amendments to the Clean Air Act reported from the Senate

Committee on Environment and Public Works; 2) H.R.3054, a bill focusing on ozone and

carbon monoxide nonattainment introduced by Congressman Waxman and 39 cosponsors; and

3) EPA’s proposed post- 1987 ozone policy, as published in the Federal Register on November

17, 1987.

In this chapter, we compare the three proposals in several ways. First, we compare

the overall requirements adopted by the three proposals. Under this broad category, we

discuss:

o Deadlines, including schedules

deadlines for the different categories of

for SIP submittals and approvals, and attainment

nonattainment areas established by each proposal.

o Schedules of emissions reductions. In addition to the ultimate requirement to attain

the standard, the proposals include interim schedules of percentage reductions of emissions

and control requirements for specific source categories. We discuss which of these

requirements will, in practice, be the driving force behind VOC reductions for each proposal.

We then compare the percentage reductions in VOC emissions under the three proposals in

1993, 1998 and 2003, assuming that the requirements can be met.

o Penalties in the event of failure, such as sanctions for failing to

SIP, penalties for falling behind the required emission reduction schedule,

not attaining the standard by the specified date.

Next. we compare the details of the emission control requirements

of the proposals. We divide the control requirements into five categories,

overlap:

submit an adequate

and penalties for

included in each

some of which

o State-implemented control requirements, for example, size cutoffs for controls on

major stationary sources and stringency of automobile inspection and maintenance programs.

129
o Federally implemented, nationwide regulation, for example, new automobile

emission standards or limits on gasoline volatility.

o NOX controls. Except for California, the States and EPA have in the past

exclusively relied on controlling VOCs for lowering ozone levels. TWO of the proposals

would require NOX controls in addition to VOC reductions.

o Controls in attainment areas in “transport regions”, for example, in the northeast

corridor, where long-distance transport of ozone or precursors may be significantly

contributing to nonattainment problems in some areas.

o Long-term strategies, i.e., how each proposal addresses new source growth,

maintenance of attainment once it is achieved, and such longer-term control approaches as

widespread use of alternatively fueled motor vehicles.

Throughout this chapter, we include relevant background information about current

implementation of the Clean Air Act, to put the proposals into context.

5.1 Overall Requirements

Attainment Deadlines And Planning Schedules

The 1977 Amendments established two dates by which nonattainment areas were to

attain the ozone standard. Areas with less severe problems were to attain the standard within

5 years, by the end of 1982. Those areas that could not attain the standard by the end of

1982 by adopting all reasonably available control measures were given an additional 5 years

(until December 1987, the deadline that recently passed).

Of the new proposals, H.R.3054 sets the tightest attainment schedules. Nonattainment

areas must meet the standard within 3, 5 and 10 years, depending on the severity of the

problem. EPA’s post- 1987 ozone policy establishes the longest schedules. Rather than

establishing absolute attainment deadlines, EPA sets a schedule for emissions reductions

under which some of the worst areas might take over 20 years to attain the standard. S. 1894

requires areas to attain the standard within 3

problem.

Each of the new proposals establishes

on: 1 ) the date by which the area is expected

to 15 years, depending on the severity of the

several categories of nonattainment areas based

to attain the standard, 2) an area’s “design

value” -- a measure of its peak ozone concentrations, or 3) a combination of the previous

two. Because more stringent control is required in those areas furthest from attainment,

more time is allowed to attain the standard, A list of nonattainment areas and their design

values can be found in Section 2.2.

130
The new proposals also set schedules for submittal and approval of SIPS. Again,

H.R.3054 sets the tightest schedules, calling for completion of the process within 15 months

after enactment. EPA’s proposed policy is the longest, allowing about 3 years.

The next two subsections discuss the deadlines included in each of the proposals in

greater detail. A later section presents OTA’s estimates of the scheduling of emissions

reductions under each of the proposals.

Attainment deadlines (by category of nonattainment area):

The three proposals establish the following categories of nonattainment areas and

attainment deadlines:

S.1894:

The Senate Environment Committee proposal creates five categories of nonattainment

areas, with attainment dates of 1991, 1993, 1998, 2003, and unspecified, depending on the

severity of the problem. More stringent controls are required in each successive category.

1 ) Nonattainment areas with a design value less than 0.14 ppm and that are able to

attain the standard by 1991 have the fewest control requirements.

2) Areas with a design value less than 0.18 ppm are presumed to be able to attain by

1993. However, those areas that declare that they cannot attain by 1993 by

adopting all of the source-specific controls required for such areas under the bill

have until 1998 to attain.

3) All areas with a design value less than 0.27 ppm must attain by 1998.

4) Areas with a design value 0.27 ppm or greater are presumed to be able to attain by

2003.

5) Areas with a design value 0.27 ppm or greater that cannot demonstrate attainment

by 2003 may follow a fixed schedule of emissions reductions and more stringent

source-specific controls, in lieu of a fixed attainment deadline.

Three year extensions are possible if additional control requirements are met. Areas

that receive extensions are to adopt the control requirements of the next highest category,

H. R .3054:

The Waxman bill establishes 3 categories of nonattainment areas with attainment

deadlines of 3, 5, and 10 years. Again, more stringent controls are required in each

successive category.

131
1 ) Nonattainment areas with a design value less than 0.144 ppm must attain the

standard within 3 years of enactment.

2) Areas with a design value between 0.144 and 0.18 ppm must attain within 5 years

of enactment.

3) Areas with a design value 0.18 ppm or greater must attain within 10 years of

enactment.

Areas that cannot attain the standard by the required 3-year or 5-year deadline

become subject to the requirements of 5-year and 10-year areas, respectively.

EPA post-1987 ozone policv:

Unlike the other two proposals, EPA’s post- 1987 ozone policy contains only one

“deadline” -- demonstrating attainment within about 6 years from the time EPA calls for a

SIP revision. The proposed policy does, however, establish several categories of

nonattainment areas based on whether additional controls are needed to attain the standard,

and if so, whether attainment can be demonstrated within the six-year time frame. Rather

than establishing attainment deadlines, the categories determine planning requirements and

whether EPA will impose certain penalties for failure. EPA’s post- 1987 policy establishes

three major categories:

1 ) Nonattainment areas with design values less than 0.16 ppm that can demonstrate

attainment within about 6 years through existing and federally implemented

control measures alone.

2) Areas able to demonstrate attainment within about 6 years by applying additional

control measures.

3) Areas not able to demonstrate attainment within 6 years.

Some rural nonattainment areas that exceed the standard because of transport of

ozone or precursors from outside of the area are classified separately.

Schedules for SIP submittals and approvals:

Under the 1977 Clean Air Amendments, EPA was to identify and list nonattainment

areas by early 1978. The States had to revise plans for each of their nonattainment areas and

submit SIPS to EPA by January 1, 1979, about 16 months after enactment. EPA was

required to approve or disapprove these plans by June 30, 1979, six months after the States

submitted them.

132
EPA and the States did not succeed in meeting many of the deadlines established in

the 1977 Amendments. By April 1980, 15 months after SIPS were due, about 20 percent of

the areas had submitted SIPS, half of which were either incomplete or considered deficient

by EPA.l This failure to have SIPS developed and approved in a timely manner continued

through the 1980s.

Table 5-1 displays the SIP actions required of the States and EPA, and compares the

amount of time allowed by Congress in the 1977 Amendments to complete these actions with

the amount of time it actually took. As the table shows, the time frame specified by the

Clean Air Act for the completion of 1979 SIP submittals WaS substantially exceeded by the

States and EPA. Rather than taking a little under two years from enactment to approval or

disapproval of a SIP, as required under the 1977 Amendments, the entire process took about

three to four and a half years.

The schedules for SIP submittals and approvals under the new proposals follow:

s. 1894:

Under the Senate Environment committee proposal, States must submit revised SIPS

for nonattainment areas before 1990. EPA must approve or disapprove the SIP within 6

months after the revision is submitted (no change from current law).

H. R.3054:

Under the Waxman bill, States must submit revised SIPS within 9 months of

enactment. EPA must approve or disapprove the SIP within 6 months after the revision is

submitted.

EPA post-1987 ozone policy:

SIPS must be submitted within 2 years from the date EPA calls for revisions. EPA

expects to complete review of each SIP within about 1 year after submittal. Nonattainment

areas that will require long-term measures to attain the standard may be granted an

additional 3 years for final SIP submittal, but must still submit an initial SIP in 2 years.

lpES study for NCAQ, 1980~ p“ 4-21-

133
Table 5-1 .

1. Designation of a

State’s attainmen t

status .

2. States’ development

of technical data base .

3. State submission o f

revised SIP (includin g

development of ozon e

control strategy an d

approval of SIP

regulations by State or

local regulator y

agency) .

w

w

& 4. EPA review and

approval or disapprova l

of SIP.

TOTAL TIME

-Time Requirements for S

Required Time

IP Proc eSS Unde r

6 months (from promulgation 8 months

of Amendments)

By January 1, 1979

(10 months from attainment

designation)

the 1977 Clean Air Act Amendments

Actual Tim e Difference

2 months

3 to 6 months minimum;

15 to 24 months maximuml

19 to 33 months 2’

3

’

4

9 to 23 months

Act allows 6 months between 9 to 24 months 3 to 18 months 5

date SIPS were due (1/79)

and date construction ban

was to have been imposed

(6/79)

22 months (1.8 years) 36 to 53 months 14 to 43 months

(3.0 to 4.4 years) (1.2 to 3.6 years)

l~study of the 1979 state Implementation Plan submittals:An Overview of the SIP Review Process at the State

Level and the SIPS for Particulate Matter, sulfur llioxide and ozone,” Pacific Environmental Services, Inc. , for

the National Commission on Air Quality, December 1980.

2PES, 1980.

3T0 Breathe Clean Air , National Commission on Air Quality, Washington, D.C. , March 1981.

kMany States started working on SIP revisions as early as 1975 or 1976, about 12 to 26 months before the 1977

Clean Air Act Amendments. This time was not included in the 19-33 month “actual” timeframe listed for Action #3.

5NCAQ, 1981; PES, 1980; and comments Of participant in OTA “ozone and the Clean Air Act” Workshop, September 30,

1987.
Schedules Of Emission Reductions

In each of the proposals, the driving force behind emissions reductions is one or more

of several types of requirements that must be met by specified dates. These requirements

include: 1 ) source-specific technology or performance standards, 2) area-wide emission

reduction requirements, and 3) attaining the standard.

We first present our subjective judgments about which of the requirements will, in

practice, be the driving force behind emissions reductions in each proposal. Our judgments

are based on two factors: 1 ) the difficulty of achieving each target by the specified date and

2) the severity of the sanctions for not meeting each of the requirements.

estimates of the overall requirements for VOC reductions (as a percentage

emissions) for each of the three proposals by 1993, 1998, and 2003.

Driving forces behind emission reductions

We then present

below 1985

While none of the proposals alters the Act’s ultimate requirement that the standard be

attained, the penalty for not attaining the standard by the specified date varies considerably

among the proposals. Each of the proposals adds interim requirements and specifies

sanctions (again, of varying seriousness) if the requirements are not met by the dates

specified.

All three proposals require some or all areas to achieve a set schedule of emissions

reductions. Though a requirement for regular increments of emissions reductions was a

relatively minor component of the 1977 amendments, it is an important driving force behind

all three new proposals.

Both S. 1894 and H.R.3054 also include source-specific technology or performance

standards, with S. 1894 requiring the most source-specific controls of the two. While both

S. 1984 and H.R.3054 set a series of deadlines for attaining the standard, S.1894’s penalties for

not meeting the deadline are much more stringent.

Discussions of the driving forces behind reductions in each of the new proposals

follow:

s. 1894.”

Under the Senate Environment Committee bill, the driving force behind emissions

reductions varies by the severity of the nonattainment problem. For those nonattainment

areas with low design values (less than about O. 14 ppm), the source-specific control

135
requirements are probably the toughest to meet. For most other areas, the bill’s requirement

for meeting a specified schedule of emissions reductions is probably the most important

driving force.

Though the bill sets 1993 as the attainment deadline for many areas, those areas that

cannot attain the standard by adopting the source-specific control requirements required

under the bill can extend the deadline until 1998. Areas with a 1998 attainment deadline

must meet an interim schedule of emission reductions: 33 percent below 1987 emissions by

1992, 50 percent by 1995, and an additional 15 percent each 3-year period until attainment.

For most areas, if this schedule is met, attainment by the bill’s deadlines is quite possible.

H,R .3054:

The Waxman bill, like S. 1894, is driven by different requirements depending on the

severity of the nonattainment problem. For those nonattainment areas with design values

0.144 ppm or less, the only requirement is to attain the standard within three years of

enactment.

For those nonattainment areas with higher design values, the Waxman bill places its

greatest emphasis on the requirement to meet an annual schedule of emission reductions.

Under the bill, the Administrator is to specify the reductions each area needs to attain the

standard and establish a schedule to achieve the reductions by the attainment deadline. It is

this annual schedule of area-wide emission reduction requirements that is the driving force

in the bill. Though requirements to actually attain the standard by specified deadlines are

included in the bill, penalties for failure to attain the standard are much less severe than the

penalties for falling behind the reduction schedule assigned by EPA.

Less emphasis is placed on source-specific control requirements in H. R.3054 than in

S. 1894. However, the bill specifies a substantial number of source-specific requirements for

the worst nonattainment areas, those with design values 0.18 ppm or higher, and for

nonattainment areas that have not attained the standard within five years after enactment.

EPA post - 1987 ozone policy:

EPA’s post- 1987 policy is driven by the single requirement for areas to follow a

specified area-wide schedule of emissions reductions. Areas must achieve emissions

reductions of 15 percent below 1987 levels by 1993 (not counting reductions from federally

implemented measures or pre - 1987 control requirements) and an additional 9 percent below

136
1987 levels every 3 years thereafter until attainment. Like the Waxman bill, it is this

schedule of area-wide emission reduction requirements that is the driving force in the EPA

policy.

Of the three proposals, the EPA plan includes the fewest source-specific control

requirements. EPA believes that current law does not require them to impose sanctions for

failure to attain the standard and does not plan to do so.

VOC Emissions Reductions Through 2003:

In this section, we present our estimates of the VOC emissions reductions required

under each of the proposals over the next 15 years. In each case, we assume that

nonattainment areas will, if given a choice, choose the set of requirements that imposes the

slowest schedule of emissions reductions possible under the proposal. (Some areas might

choose faster schedules to avoid certain source-specific controls often required as a condition

for the slower schedule, but such cases are difficult to predict.)

Tables 5-2 through 5-4 show our estimates of the VOC reductions required, as a

percent of 1985 emissions, for 1993, 1998, and 2003. These are based on our conclusions

about the driving forces behind each of the proposals presented in the previous section, and

city-specific analyses of control requirements to meet the standard presented in Chapter 3.

Each table includes separate estimates for four design value categories used in the

proposals. (Note, however, that not all categories are used in all proposals. ) Where

appropriate, we present both an average reduction figure, and under it, a range that

corresponds to the variation among all cities in the category. The details of the reduction

requirements are presented in a later section of this chapter. Here we present a rough

estimate of the total reduction requirements.

Table 5-2 shows the VOC reduction targets for 1993. Overall, the Senate Committee

bill requires the highest percentage of VOC emissions reductions by 1993 and the EPA

proposal the lowest. This varies by nonattainment category, however, as can be seen in the

table and discussed briefly below.

For nonattainment cities with the least severe problem (design values in the range of

0.13 to 0.14 ppm), all three proposals require approximately the percentage reductions in

VOC emissions (20 to 40 percent) needed to attain the standard. However, for some areas

with design values of O. 13 ppm, the source-specific requirements of S. 1894 may result in

slightly higher reductions than needed to attain the standard.

137
Table 5-2--VOC Emission Reduction Requirements by 1993 Under

s. 1894, H.R. 3054, and EPA’s Post-1987 Ozone Policy

Note that for some categories, cities are allowed to choose either attainment or a percentage

emission reduction requirement. Both the average reduction requirement and the range is shown.

Potential

EPA reductions from

Design value post-1987 1985 emissions,

category 1985 emissions To attain the S.1894 H.R. 3054 policy based on OTA

(ppm ozone) (1000 tons/yr) standard (%) (%) (%) (%) analysis (%)a

‘J

cm 0.15 - 0.17

0,18 - 0.26

3,600 53

(40-65)

1,100 60

(52-69)

0.27 or higher 770 84

(80-90)

Attainment Attainment

or

z

30

(22-35)

40

40

30 26

(26-35) (23-27)

29

25

22

d ‘l]lis colu[nn S!IOWS the projected !’UC (~mi:,sions r(’ducri~)[l’~ (Cls d pcrcentase of 1985 levels) that each

,TI-OUp of cities cc~n achie~’e bv 1991 if all fid(ii[ior)al rr)obile and stationary source control strategies ,)

‘*’L’ ,~IIc-il>’zed are adop LLId in .ldditio[l :(0 KIIC SEaLU an(t [:PA VOC regulations in place in 1985.
Table 5-3--- VOC Emission Reduction Requirements by 1998 Uncle r

S. 1894, H.R. 3054, and EPA’s Post-1987 Ozone Policy

Design 1985 To attain

value em iss ions the EPA postcategory ( 1000 standar d S. 1894 H.R. 3054 1987 policy

(ppm ozone) tons/year ) (%) (%) (%) (%)

0.13 - 0.14 2,200 31 Attainment Attainment Attainment

(19 -44)

0.15 - 0.17

0.18 - 0.26

0.27 or

highe r

3,600

1,10 0

770

53

(40-65)

60

(52-69 )

84

(80-90 )

Attainment

65

Attainment

Attainment

Attainment

45

(37-51)

4 0

(36-40 )

37

(33-41 )
Table 5-4--VOC Emission Reduction Requirements by 2003 Under

S. 1894, H.R. 3054, and EPA’s Post-1987 Ozone Policy

Note that for some categories, cities are allowed to choose either attainment or a percentage

emission reduction requirement. Both the average reduction requirement and the range is shown.

Design 1985 To attai n

valu e emissions the EPA postcategory (1000 standar d S. 1894 H.R. 3054 1987 policy

(ppm ozone) tons/year) (%) (%) (%) (%)

0.13 - 0.1 4 2,20 0 31 Attainment Attainment Attainment

(19-44)

0.1 5 - 0.1 7

0.1 8 - 0.2 6

0.27 o r

highe r

3,60 0

1,100

770

53

(40-65 )

60

(52-69 )

84

(80-90 )

Attainment

Attainment

Attainment

Attainment

Attainment

Attainment

Attainment

o r

G

(49-62)

51

(48-52 )

49

(48-51 )
For the next group of cities, those with design values between 0.15 and 0.17 ppm,

H.R.3054 requires attainment by 1993. S.1894 presumes attainment by this date, but areas

can opt for a later deadline. We estimate that attainment would require VOC reductions in

the range of 40 to 65 percent -- a level probably not achievable by 1993. In such a situation

S. 1894 specifies a minimum of 40 percent emissions reductions. The EPA proposal requires

the lowest reductions, between about 20 and 35 percent.

For the next category, cities with design values between 0.18 and 0.26 ppm, S. 1894

once again requires VOC reductions of about 40 percent. H.R.3054 requires cities to meet a

schedule assigned by EPA, which we estimate as half the reductions needed to attain the

standard, or about 25 to 35 percent. The EPA proposal would require reductions in these

cities of about 25 percent.

In the cities with the highest ozone concentrations, those with design values above

0.27 ppm, we estimate that both the Senate Committee bill and the Waxman bill require

reductions of about 40 percent by 1993. EPA’s proposal requires reductions of about 25

percent.

The last column in Table 5-2 repeats our estimates of the reductions achievable from

the control strategies we were able to analyze in Chapter 3. Note that by about 1993, all

three proposals require emissions reductions about equal tO or greater than? the amount

obtainable from the near-term control measures that we were able to identify.

Table 5-3 shows the VOC reductions required by 1998. By 1998, the Waxman bill

requires more VOC control in some areas than the Senate committee bill; the EPA proposal

requires the least. Under H.R.3054, all areas are required to attain the standard by 1998 or

earlier. As shown in the third column of the table, this might require VOC reductions in

excess of 80 percent in areas with the highest design values. The Senate Committee bill

requires attainment in most areas or minimum emission reductions of 65 percent below

current levels. The EPA proposal requires the lowest reductions, in the range of 40 percent.

This would bring most cities with design values below about 0.15 ppm into attainment.

Table 5-4 displays the VOC reduction requirements in 2003, 15 years from now.

Again, under H.R.3054, all areas are required to have attained the standard by 1998. S.1894

requires attainment or, at minimum, reductions of 90 percent below current levels. The EPA

proposal requires reductions of about 50 percent, enough to bring most cities in the two

lowest design value categories into attainment.

141
Penalties In The Event Of Failure

Each of the three proposals specifies penalties in the event of failure to meet its

various requirements. All three proposals distinguish between: 1) the failure of a State to

submit an adequate SIP or to implement the required emissions reductions and 2) failure to

attain the standard by a given date. Failure to meet the first set of requirements leads to

serious sanctions in all three proposals. Failure to actually attain the standard by a given

date results in penalties under both the Senate bill and the Waxman bill, with the Senate bill’s

penalties the more severe of the two. The EPA proposal does not include penalties for

failure to attain by a set date, only for failure to adequately plan for attainment.

The Senate and House proposals also include penalties or default provisions in the

event EPA does not issue control technique guideline documents (CTGs) for several

categories of sources. The Senate bill adds a new penalty for owners of stationary sources

that fail to implement reductions required in certain situations.

In this section, we present the penalties included in the proposals for each of the four

situations mentioned above.

Failure to adequately plan or implement reductions

For failure of a State to submit an adequate SIP by the required date, or failure of a

State or local area to adequately implement required emissions reductions, the proposals

include the following penalties:

s. 1894:

1)

2)

3)

Ban on construction or modification of major stationary sources in the

nonattainment area. (The ban applies to new sources emitting more than 25 tons

per year of VOC or NOX

, and modifications larger than 10 tons per year.)

No Federal highway funds other than for safety, mass transit, or transportation

improvement projects related to air quality.

In areas that choose a deadline later than 1993, no sewer hookups to a publicly

owned sewage treatment works unless each ton of VOC emissions from or

associated with the sewage treatment plant is offset by 4 tons of reductions

elsewhere in the nonattainment area.

H.R ,3054:

1)

2)

No Federal highway funds other than for safety, mass transit, or transportation

improvement projects related to air quality.

Each ton of emission increases from new or modified stationary sources must be

offset by 5 tons of reductions from other sources in the nonattainment area.

142
EPA post - 1987 ozone policy:

1)

2)

3)

4)

Failure to

Mandatory ban on construction or modification of major stationary sources in the

nonattainment area. (The ban applies to new sources emitting more than 100 tons

per year of VOC, and modifications larger than 40 tons per year.)2

Discretionary ban on federal highway funds other than for safety, mass transit, or

transportation improvement projects related to air quality.3

Discretionary ban on federal sewage treatment grants.4

Discretionary ban on federal grants to a State’s air pollution control agency.5

attain the standard

For failure to attain the standard by the required date, the proposals include the

following penalties:

S. 1894:

1 ) Ban on construction or modification of major stationary sources in the

nonattainment area.

2) No Federal highway funds other than for safety, mass transit, or transportation

improvement projects related to air quality.

H.R .3054:

1)

2)

Areas with a design value less than 0.144 ppm become subject to the requirements

for areas with a design value between 0.144 and 0.18 ppm,

Areas with a design value between 0.144 and 0.18 ppm become subject to the

requirements for areas with design values greater than 0.18 ppm,

zBased on Section 11 ()(a)(2)(I) of the current Act, which requires the Administrator to prohibit

the construction of major stationary sources in nonattainment areas if a SIP revision is

inadequate.

3Based on Section 176(a) of the current Act, which requires

federal highway funds, except those for safety, mass transit

projects related to air quality. EPA interprets this sanction

the Administrator to withhold

and transportation improvement

to be dependent on a discretionary

finding by the Adminktrator that an area failed to make a reasonable effort to submit a plan -

meeting Part D requirements. EPA’s interpretation was recently upheld in court.

4Based on Section 316 of the current Act, which allows the Administrator discretion to

withhold, condition or restrict federal grants for sewage treatment plant construction.

sBased on Section 176(b) of the current Act, which enables the Administrator tO halt federal air

program grants if a State or local area fails to adequately implement their SIP. EPA has

interpretted this sanction to be discretionary. Others argue that it is mandatory.

143
3) Areas with a design value greater than 0.18 ppm must offset each ton of emissions

increases from new or modified stationary sources with 5 tons of reductions from

other sources in the nonattainment area.

EPA’s post - 1987 ozone policy:

None proposed.6

Failure of EPA to issue required “control technique guidance” documents

If EPA fails to issue required control technique guidance documents (CTGs) by the required

date, the following penalties are proposed:

S. 1894:

Sources in the category

reduce emissions by 90

H.R.3054:

Sources in the category

and NOX emitted.

EPA post - 1987 ozone policy:

Not applicable.

to which the CTG would have applied are required to

percent from uncontrolled levels.

are required to pay an annual fee of $5000 per ton of VOC

Failure of stationary sources to control

For failure of stationary sources to implement required reductions, the following

penalties are proposed:

S. 1894:

In areas with a design value greater than 0.18 ppm, sources that do not reduce

emissions by the percentage required for the nonattainment area as a whole are

required to pay an excess emissions penalty equal to the cost of control, or an

annual penalty of $5000 per ton, whichever is greater.

H.R.3054:

No new penalties proposed.

‘Note that GAO believes that Section 110 requires the Administrator to prohibit the

construction of major stationary sources in this case. EPA has held that this sanction should

apply to areas with approved plans that predicted attainment by the deadline but failed to

actually attain the standard by the deadline.

not

144
EPA post - 1987 ozone policy:

No new penalties proposed.

5.2 Control Requirements

To help compare the control requirements of the three proposals, we have organized

the requirements into five categories. Because air pollution control under the clean Air Act

relies on a partnership between EPA and State and local governments, our first two

categories present: 1 ) controls to be implemented by the States in nonattainment areas and 2)

federally implemented controls that apply nationwide.

Three additional categories are then discussed: 1) controls in areas that are currently

in attainment, but that contribute to nonattainment in other regions through transport of

ozone or the pollutants from which it is formed, 2) controls on nitrogen oxides (previously

applied only in California), and 3) long-term strategies to attain or maintain compliance with

the standard. The first two, if adopted, would be new additions to the Clean Air Act. The

last category is highlighted because of the importance of controlling new sources of emissions

(a problem identified as one of the reasons why the 1977 Amendments were less effective

than anticipated).

Control Requirements To Be Implemented BY States In Nonattainment Areas

In each of the proposals different requirements apply to nonattainment areas

depending on their “design value” -- a measure of peak ozone concentrations -- and the date

by which they are expected to attain the standard. These categories were presented in a

previous section; this section provides details on the controls specified for each category of

nonattainment area in the new proposals and under existing law.

Both S. 1894 and H. R.3054 require EPA to issue new “control technique guidelines”

(CTGs), which establish the level of control considered to be “reasonably available”

(reasonably available control technology or RACT) and thus required for stationary sources

in nonattainment areas. The requirements for new CTGs are also presented in this section.

As background, we first review the requirements of the current Act. The Clean Air

Act Amendments of 1977 created two categories of nonattainment areas. The following

State-implemented controls were required under regulations issued by EPA:

145
1)

2)

Areas that could demonstrate attainment by December 1982:

‘Reasonably available control technology” (RACT) for all stationary sources of

VOC emitting greater than 100 tons per year, for which EPA issued CTGs prior to

1979. 7

Areas that received extensions of the attainment deadline to December 1987

(“extension” areas):

a)

b)

c)

d)

RACT for all stationary sources of VOC for which CTGs have been issued,

including those issued 1979 and later.8

RACT for all stationary sources of VOC emitting greater than 100 tons per

year for which CTGs have not been issued.

Inspection and maintenance (1/M) program for highway vehicles.

“Lowest achievable emission rate” (LAER) of VOC for new stationary

sources emitting more than 100 tons per year or modified stationary sources

emitting more than 40 tons per year.

The new proposals require the following controls to be implemented by the States in

nonattainment areas:

S.1894:

The Senate Environment Committee proposal creates five categories of nonattainment

areas, with the following State-implemented controls required:

Tprior t. 1979, EpA issued the following CTGS, which presumptively determine RACT:

1)

2)

3)

4)

Surface coating regulations, including CTGS for coating cans, coils, paper, fabrics,

autos and light duty trucks, metal furniture, magnet wire, large appliances, flatwood

paneling, and miscellaneous metal parts.

Other solvent-related regulations, including CTGS for graphic arts, metal decreasing,

and drycleaners using perchloroethylene.

Petroleum-related regulations, including CTGS for bulk gasoline plants and terminals,

liquids in fixed- and floating-roof tanks, miscellaneous sources in petroleum

refineries, gasoline tank trucks, and delivery of gasoline to service stations.

Several additional regulations, including rubber tire manufacture, pharmaceutical

manufacture, and cutback asphalt.

8EPA issued the following CTGS 1979 and 1ater:

a)

b)

c)

Regulations for large petroleum drycleaners.

Synthetic organic chemical industry (SOCMI) related regulations, including CTGS for

high density plastic resins, air oxidation processes, volatile organic storage tanks, and

leaks.

Regulations applying to leaks from natural gas and gas processing plants.

146
1)

2)

3)

4)

Areas with a design value less than 0.14 ppm that can attain by 1991:

a)

b)

c)

d)

At least one of the following mobile-source related measures:

1)

2)

3)

RACT

Enhanced inspection and maintenance (1/M) program for highway

vehicles in urban areas with more than 100,000 people.

“Stage II” control devices on gasoline pumps to capture emissions

during refueling.

Use of alternative

vehicles.

for both VOC and

25 tons per year.

LAER for both VOC and

fuels by

N OX o n

NO.. for

than 25 tons per year or modified

tons per year.

centrally-fueled fleets with 50 or more

stationary sources emitting greater than

new stationary sources emitting more

stationary sources emitting more than 10

“Such other measures as may be necessary to provide for attainment”.

Areas that can attain by 1993:

All of the measures listed in 1 ) above, including all three mobile-source related

measures.

Areas that choose a deadline later than 1993:

All of the measures listed in 1) above (including all three mobile-source related

measures), plus:

a) Adoption of “transportation control measures” (TCMs)

vehicle miles traveled (VMT), or emissions associated

VMT.

to offset growth in

with increases in

b) Area-wide emissions reductions (below the 1987 base) of both VOC and

N ox

:

33 percent by 1992,

50 percent by 1995,

65 percent by 1998.

c) Each stationary source emitting more than 25 tons per year of VOC or NOX

must achieve reductions of both pollutants from 1987 levels at least equal

to the area-wide requirement.

Areas with a design value of 0.27 ppm or greater:

All of the measures listed in 3) above, plus, in each 3 year period after 1998 until

attainment, an additional 15 percent area-wide emission reduction (below the 1987

base) of both VOC and NOX

,

147
5) Areas that cannot demonstrate attainment by 2003:

All of the measures listed in 4) above plus:

a) Adoption of transportation control measures to assure that passenger vehicle

occupancy on highways exceeds 1.5 people per vehicle.

b) Emission standards for off-highway vehicles at least as stringent as those in

effect for cars.

c) By 1998, 15 percent, and by 2003, 40 percent, of motor vehicles must be

able to use alternative fuels.

d) Commercial and residential sources of VOC and NOX emitting more than

one ton per year must reduce emissions to the maximum extent possible.

The Senate Environment Committee proposal requires EPA to issue the following

CTGs:

1 ) Within two years of enactment, EPA must issue CTGs for sources emitting more

than 25 tons per year of VOC or NOX

, for the following 11 source categories:

Wood furniture coating; autobody refinishing; metal rolling; synthetic organic

chemical industry (SOCMI) distillation; SOCMI batch process; hazardous waste

treatment, storage, and disposal facilities; bakeries; sewage treatment plants; web

offset lithography; plastic parts coating; and coke oven by-product plants.

2) Within four years of enactment, EPA is to revise all existing CTGs to be consistent

with the bill’s definition of “reasonably available control technology”. These CTGs

are to apply to sources emitting more than 25 tons per year of VOC or NOX

.

H.R.3054:

The Waxman bill creates three distinct categories of nonattainment areas, with the

following State-implemented controls required:

1 ) Areas with a design value less than 0.144 ppm:

Annual percentage reduction in VOC and NOX sufficient to attain the standard

within 3 years, as calculated by EPA.

2) Areas with a design value between 0.144 and 0.18 ppm:

Annual percentage reduction in VOC and NOX sufficient to attain the standard

within 5 years, as calculated by EPA, plus:

a) Enhanced inspection and maintenance (1/M) program for highway vehicles

in urban areas with more than 100,000 people.

b) LAER for both VOC and NOX for new or modified stationary sources

emitting greater than 25 tons per year.

148
3) Areas with a design value greater than 0.18 ppm:

Annual percentage reduction in VOC and NOX sufficient to attain the standard

within 10 years, as calculated by EPA, plus:

a) Enhanced inspection and maintenance (1/M) program for highway vehicles

in urban areas with more than 100,000 people.

b) LAER for both VOC and NOX for new or modified stationary sources

emitting greater than 10 tons per year.

c) Fleets of 15 or more vehicles must be capable of using alternative fuels.

By 1997, 30 percent of new motor vehicles must be able to use alternative

fuels.

d) Catalytic control technology (or technology that achieves equivalent

emission rates) on all oil- and coal-fired boilers.

The Waxman bill requires EPA to issue CTGs for the 12 categories of uncontrolled

stationary sources that make the most significant contribution to ozone formation, in the

judgment of the Administrator. EPA must promulgate 4 CTGs by 1988 and 2 CTGs per

year for succeeding years. The CTGs are to apply to sources emitting more than 25 tons per

year of VOC or NOX

.

EPA post - 1987 ozone policy:

The EPA proposal creates three distinct categories of nonattainment areas, with the

following State-implemented controls required:

1 ) Areas with a design Value less than 0.16 ppm and able to demonstrate attainment

with federally implemented and existing control measures within about 6 years:

No new control requirements

2) Areas able to demonstrate attainment within about 6 years:

a) Enhanced inspection and maintenance (1/M) program for highway vehicles

in urban areas with more than 200,000 people.

b) RACT for all stationary sources of VOC emitting greater than 100 tons per

year (including those for which CTGs have not been issued), unless the

State can convincingly demonstrate that not all controls will be required to

reach attainment.

c) VOC emissions reductions of at least 3 percent per year below 1987 levels,

not counting reductions from 1 ) federally implemented measures or 2)

control requirements imposed prior to 1987.

149
3) Areas not able to demonstrate attainment within 6 years:

All of the measures listed in 2) above, with no exemptions for the

requirement of RACT on major stationary sources.

Federally Implemented. Nationwide Control Requirements

In this section we review the nationwide controls required under current laws and

regulations and summarize the changes and additions under the new proposals.

Current law and regulations include the following controls:

1)

2)

3)

4)

New source performance standards (NSPS) requiring the “best available control

technology” on certain new stationary sources of VOC and NOX

.

9 (Note that the

“lowest achievable emission rate” for VOC required for new sources in

nonattainment areas can be more stringent than the nationwide NSPS controls. )

Tailpipe exhaust standards for passenger cars:

0.41 grams per mile (g/mi) hydrocarbon (HC) and 1.0 g/mi NOX

. Standards must

be met for at least 5 years or 50,000 miles.

Tailpipe exhaust standards for light duty trucks:

a) 0.8 g/mi HC and 1.2 g/mi NOX for trucks with gross vehicle weights up to

3750 lbs.

b) 0.8 g/mi HC and 1.7 g/mi NOX for trucks with gross vehicle weights over

3750 lbs.

Standards must be met for 120,000 miles.

Tailpipe exhaust standards for heavy duty diesel engines:

a) 1.3 grams per brake-horsepower-hour (g/bhp-hr) HC and 10.7 g/bhp-hr

NOX

.

b) 5.0 g/bhp-hr NOX by model year 1991.

Standards must be maintained for 120,000 miles.

‘EPA has

1)

2)

3)

4)

issued NSPS for the following VOC sources:

Surface coating regulations, including NSPS for coating large appliances, metal

furniture, autos and light duty trucks, beverage cans, metal coils, magnetic tape,

pressure sensitive tapes and labels, and flexible vinyl coating.

Petroleum-related regulations, including NSPS for petroleum refining, refinery

wastewater, bulk gasoline terminals, storage vessels, and natural gas production.

Synthetic organic chemical industry (SOCMI) related regulations, including NSPS for

air oxidation equipment, distillation operations, reactors and other equipment.

Others including NSPS for dry cleaning, graphic arts, synthetic fiber production, and

rubber tire manufacture.

150
5) Limits on gasoline evaporation from highway vehicles.

S. 1894:

The Senate Environment Committee proposal includes the following changes and additions to

current laws and regulations:

1)

2)

3)

4)

5)

6)

Tailpipe exhaust standards for passenger cars and trucks under 6000 lbs:

a) 0.25 g/mi HC by model year 1992.

b) 0.4 g/mi NOX by model year 1990.

Pollution control equipment must be able to meet these standards for at least 10

years or 100,000 miles.

Tailpipe exhaust standards for light duty trucks:

a) 0.5

b) 0.5

Light duty

g/mi HC by model year 1990.

g/mi NOX by model year 1990.

trucks are defined as those with gross vehicle weight (gvw) between

6000 and 8500 lbs and curb weight less than 6000 lbs. Trucks less than 6000 gvw

are considered light duty vehicles.

N OX exhaust standards for heavy duty vehicles:

a) 4.0 grams per brake-horsepower-hour (g/bhp-hr) by model year 1991.

b) 1.7 g/bhp-hr by model year 1995.

“Onboard” technology for cars and trucks to control refueling emissions by model

year 1991,

Limit on the volatility (i.e., rate of. evaporation) of gasoline sold during warm

weather months of 9 lbs Reid Vapor Pressure (RVP) beginning in 1990.

Regulations for the following source types, promulgated by EPA within 2 years

after enactment, to achieve the degree of control equivalent to adoption of

reasonably available control technology (RACT): ( 1 ) commercial solvents, (2)

consumer solvents, (3) architectural coatings, (4) pesticide application, (5) trafficmarking coatings, and (6) metal-parts coatings for military applications and

aerospace- industry applications.

H. R.3054:

The Waxman bill includes the following changes and additions to current laws and

regulations:

151
1 ) Tailpipe exhaust standards for passenger vehicles:

a) 0.25 g/mi HC by model year 1992.

b) 0.4 g/mi NOX by model year 1990.

Standards must be maintained for 50,000 miles.

2) Tailpipe exhaust standards for light duty trucks:

a) 0.5 g/mi HC by model year 1990.

b) 0.5 g/mi NOX by model year 1990.

Standards must be maintained for 120,000 miles.

3) NOX exhaust standard for heavy duty trucks of 1.7 grams per brake-horsepowerhour (g/bhp-hr) by model year 1994.

4) “Onboard” technology for cars and trucks to control refueling emissions by model

year 1990.

5) Limit on the volatility (i.e., rate of evaporation) of gasoline sold between May 16

and September 15 of 10.5 lbs Reid Vapor Pressure (RVP) beginning in 1990, 9.0

lbs RVP beginning in 1993.

6) Regulations to achieve the lowest feasible emission rate for the following source

types, promulgated by EPA by 1990: commercial and consumer solvents,

architectural coatings, pesticide application, traffic-marking coatings, and metalsparts coatings in military applications.

EPA post - 1987 ozone policv:

EPA has proposed the following changes and additions to current laws and regulations:

1 ) Tailpipe exhaust standards for light duty trucks:

a) 0.41 g/mi HC for trucks weighing less than 6000 lbs gvw.

b) 0.5 g/mi HC for light duty trucks weighing 6000 lbs gvw or greater.

(Advanced notice of proposed rulemaking published September 1986.)

2) “Onboard” technology for cars and trucks to control refueling emissions by model

year 1990. (Notice of proposed rulemaking published August 1987. )

3) Limits on the volatility (i.e., rate of evaporation) of gasoline sold between May 16

and September 15 of 10.5 lbs Reid Vapor Pressure (RVP) beginning in 1990, and

9.0 lbs RVP beginning in 1993. (Notice of proposed rulemaking published August

1987. )

152
Transport Regions

Both ozone and its precursors, VOC and NOX, can be transported from upwind areas

into nonattainment regions downwind. Thus, some fraction of the ozone found in

nonattainment areas is not subject to local regulatory authority. If the upwind area is also a

nonattainment region, at least some further control will take place to bring the area into

attainment with the standard. However, if the upwind region already meets the standard, no

further control can be expected. Current law does not provide an adequate mechanism to

implement controls in areas that currently attain the standard, but contribute to ozone

nonattainment problems in areas downwind.

To address

transport regions”.

attainment status.

Maine to Virginia;

proposal identifies

this problem, both S. 1894 and H. R.3054 establish multi-state “ozone

Controls are required throughout these multi-state regions, regardless of

Both bills establish a transport region along the Northeast corridor from

S. 1894 establishes a second one in the Midwest. Though the

the Northeast corridor as a region where multi-day transport

additional control requirements are proposed.

Discussions of each of the new proposals follow:

S. 1894:

The bill establishes two “ozone transport regions”: one along the Eastern

EPA

occurs, no

seaboard

from Maine to the northern half of Virginia, plus Vermont, New Hampshire, Pennsylvania

and Ohio; the second, which includes Illinois, Indiana, Michigan, and Wisconsin. The

Administrator may add States to these regions or create additional regions.

The bill requires:

1)

2)

A

Enhanced inspection and maintenance (1/M)

urban areas with more than 125,000 people.

RACT on stationary sources for which EPA

enactment.

commission of Governors and EPA officials

program for highway vehicles in

has published CTG’s prior to

is established to make decisions about

additional controls, which must be adopted by all States in the transport region if voted for

by a majority of the commission.

H.R .3054:

The bill establishes one “ozone transport region” along the Eastern seaboard from

Maine to Virginia, plus Vermont, New Hampshire, and Pennsylvania. The Administrator

153
—

may add States to this region or create additional regions. Individual counties, air

control regions (AQCRs), or States may be exempted from control requirements if

not significantly contribute to other region’s nonattainment problems.

Administrator or a commission of EPA and State air pollution control

areas.

Either the

officials can

quality

they do

exempt

Specific control requirements for ozone transport regions are the same as those

mandated

1)

2)

3)

for areas with design values between 0.144 and 0.18 ppm:

Enhanced inspection and maintenance (1/M) program for highway vehicles in

urban areas with more than 100,000 people.

LAER for both VOC and NOX for new or modified stationary sources emitting

greater than 25 tons per year.

It is unclear whether the Administrator can specify additional reductions in VOC

and NOX

, and if so, whether the Administrator or the commission decides which

source categories are to control emissions.

EPA’s post - 1987 ozone policv:

EPA will require that planning areas cover entire metropolitan areas (MSAs or

CMSAs) to address single-day transport problems. EPA identifies the Northeast corridor as

the only region where multi-day transport is a problem. No special requirements for this

region are proposed.

Controls On Emissions Of Nitrogen Oxides

Ozone is produced via chemical reactions of both VOC and NOX. In the past, EPA

has encouraged exclusive reliance on control of VOC emissions to achieve compliance with

the ambient air quality standard for ozone. Only California has mandated controls of both

VOC and NOX emissions.

In Section 3.1, we discussed the site-specific situations under which NOX controls

would lower ozone concentrations and the situations where NOX controls might be

counterproductive. Combined VOC and NOX controls will result in lower ozone

concentrations than VOC controls alone in many cities. However, in some cities, for

example, Baltimore, Boston, Philadelphia, and Washington, combined controls may lead to

higher ozone concentrations in some locations within the urban area than would VOC

reductions alone. Further complicating the decision about whether to mandate NOX controls

is the expectation that while NOX controls might be counterproductive for some locations

within the urban area, they might lower ozone concentrations in the next city downwind.

154
Each of the three proposals includes NOX controls to some degree, and with varying

degrees of flexibility. The Senate Environment Committee proposal requires NOX reductions

from both existing and new sources in all nonattainment areas. The Waxman bill requires

some NOX control, but not as much as the Senate proposal. Control of new sources of NOX is

required; the extent to which existing sources of NOX must be controlled is left to EPA to

decide. The EPA proposal allows States to supplement VOC controls with NOX controls, and

in some cases substitute NOX controls for VOC, but does not require NOX controls.

Discussions of each of the new proposals follow:

S. 1894:

The Senate Environment Committee proposal applies controls about equally to sources

of both NOX and VOC. Requirements for reasonably available control technology (RACT)

on major stationary sources apply to both VOC and NOX in nonattainment areas (but to VOC

alone in attainment areas in transport regions). Percentage reduction requirements for

nonattainment areas that cannot attain the standard before 1993 are identical for both

pollutants, as are most other requirements of the bill. NOX emission standards for new cars

and trucks are lowered.

In addition, Title II, the portion of the bill that addresses acid deposition, establishes

a Statewide maximum emission rate on NOX from fossil-fuel fired boilers.

H.R .3054:

The Waxman bill deals with NOX control in the following way:

1 ) For all nonattainment areas, the Administrator of EPA must specify the percentage

reduction of both VOC and NOX needed to meet the standard by the assigned

deadline. Thus the decision of whether to rely on VOC controls alone or

combined VOC/NOX control from existing sources is left to EPA.

2) In nonattainment areas with design values greater than 0.144 ppm, new source

controls are required on new and modified stationary sources of NOX above 25

tons per year.

3) In nonattainment areas with design values greater than 0.18 ppm:

a) New source controls are required on new and modified stationary sources

of NOX above 10 tons per year.

b) Catalytic technology for the control of NOX emissions (or a technology that

achieves equivalent emission rates) is required for all oil- and coal-fired

boilers.

4) NOX emission standards for new cars and trucks are lowered.

155
5) EPA must issue control technique guidelines for 12 categories of uncontrolled

stationary sources. The guidelines are to apply to VOC, NOX

, or both, at the

discretion of the Administrator.

EPA’s post-1987 ozone policv:

The EPA proposal requires some nonattainment areas (those with high ratios of VOC

to NOX in the ambient air) to evaluate the effectiveness of NOX reductions. In those

nonattainment areas where a State determines that NOX controls will be beneficial, NOX

controls may be used in addition to VOC controls to satisfy the EPA requirements for

“reasonable progress” towards attainment. However, while NOX controls can supplement VOC

controls, they cannot be used to avoid VOC controls on major stationary sources, unless the

likelihood of attainment is demonstrated by rigorous air quality modeling.

Long-Term Strategies

Even though most of the requirements listed below have already been presented in

earlier sections of this chapter, in this section we highlight the requirements that will help

attain or maintain the standard over the long-term. These include such components as more

stringent emission standards for gasoline- and diesel-fueled motor vehicles, use of

alternatively fueled motor vehicles, and strategies to prevent growth in emissions from

stationary sources.

As discussed in Chapter 3, even after applying all near-term control measures OTA

was able to analyze, many areas will still not attain the standard. Thus, while many areas’

ozone nonattainment problems may be remedied in about five years, for many others, ozone

nonattainment may remain as a chronic problem for at least a decade. For such areas, two

issues must be addressed: 1 ) additional controls must be identified, some of which (like new

motor vehicle controls or use of alternative fuels) may take a decade or more to take effect

and 2) steps must be taken to offset emissions increases due to population and economic

growth.

The proposals include the following long-term strategies to address ozone

nonattainment problems over the next decade or two:

S. 1894:

The Senate Environment Committee proposal requires:

1 ) SIPS must address maintenance of the standard for 20 years after enactment.

156
2)

3)

4)

5)

6)

New stationary sources in nonattainment areas em tting more than 25 tons per yearand modified stationary sources emitting more than 10 tons per year must achieve

the “lowest achievable emission rate” (LAER). The current cutoffs for most

nonattainment areas are 100 tons per year for new sources and 40 tons per year for

modified sources.

Use of alternative fuels for centrally fueled fleets of 50 or more vehicles.

tighter emission standards for cars and trucks.

In areas that choose an attainment deadline past 1993:

a)

b)

Each ton of emissions increases from new or modified major stationary

sources must be offset by 2 tons of reductions from other sources in the

nonattainment area.

Growth in vehicle miles traveled (VMT), or emissions associated with VMT

growth, must be offset.

In areas that cannot demonstrate attainment by 2003:

All of the measures

a)

b)

Adoption of

listed in 5) above plus:

transportation control measures to assure that passenger vehicle

occupancy on highways exceeds 1.5 people per vehicle.

By 1998, 15 percent, and by 2003, 40 percent, of motor vehicles must be

able to use alternative fuels.

H.R.3054:

The Waxman bill requires:

1 ) SIPS to include plans for maintaining the standard.

2) tighter emission standards for cars and trucks.

3) In nonattainment areas with a design value greater than 0.144 ppm, new or

modified stationary sources in nonattainment areas emitting greater than 25 tons

per year are subject to new source control requirements. The current cutoffs for

most nonattainment areas are 100 tons per year for new sources and 40 tons per

year for modified sources. Each ton of emissions increases from new or modified

major stationary sources must be offset by reductions of 1.2 tons from other

sources.

4) In nonattainment areas with design value greater than 0.18 ppm:

a) New or modified stationary sources in nonattainment areas emitting greater

than 10 tons per year are subject to new source control requirements. Each

ton of emissions increases from new or modified major stationary sources

must be offset by reductions of 1.5 tons.

157
.

b)

c)

Fleets of 15 or more vehicles must be capable of using alternative fuels.

By 1997, 30 percent of new motor vehicles must be able to use alternative

fuels.

All new boilers must use catalytic control technology (or equivalent) or

burn natural gas, methanol, or ethanol.

EPA’s post-1987 ozone po!icu:

Under EPA’s proposed ozone policy:

1) To be redesignated as an attainment area, a State must project emissions and detail

control requirements for 10 years after attainment.

2) Under current regulations, new stationary sources in

greater than 100 tons per year and modified stationary sources

nonattainment areas emitting

emitting greater than 40 tons

per year must achieve the “lowest achievable emission rate” (LAER). Emissions must either

be directly offset with decreases at other sources or the State must adopt a strategy to

provide “growth accommodation” by controlling beyond federally prescribed measures and

other measures needed to show “reasonable further progress”.

158
Appendix A. Assumptions Used to Calculate Volatile Organic Compound Emissions Reduction Potential and

Associated Costs of Control

Control COST-EFFECTIVENESS :

b

Control Strategya/ Efficiency Small Medium Large

Source Description Control Technique (%) ($/ton) ($/ton) ($/ton)

RACT:

Solvent metal cleaning: large sourcec

small sourcec

Printing and publishing: large source

small source

Dry cleaning: large source

small source

Fixed roof tanks-crude oil

Fixed roof tanks-gasoline

External floating roof tanks-crude oil

External floating roof tanks-gasoline

Bulk gasoline terminals-splash loading

Bulk gasoline terminals-submerged

loading, balanced service

Bulk gasoline terminals-submerged

loading, not balanced

Service stations-Stage I

Ethylene oxide manufacture

Phenol manufacture

Terephthalic acid manufacture

Acrylonltrile manufacture

SOCMI fugitives

Petroleum refinery fugitives

Cellulose acetate manufacture

Styrene-butadiene rubber manufacture

Polypropylene manufacture

Polyethylene manufacture

Ethylene manufacture

Carbon adsorber 54

Carbon adsorber 83

Carbon adsorber 85

Carbon adsorber 85

Recovery dryers 70

Recovery dryers 70

Internal floating roof 98

Internal floating roof 96

Secondary seal 90

Secondary seal 95

Submerged load, balanced service

carbon absorb, truck test

Carbon adsorb, truck test

Balanced serv, truck test

Vapor balance

Incinerator

Incinerator

Incinerator

Incinerator

Equipnent & ❑ aintenance

Equipment & maintenance

Carbon adsorber

Incinerator

Flare

Flare

Flare

Petroleum refinery wastewater separators Firebox covers

Petroleum refinery vacuum distillation

Vegetable oil processing

Paint and varnish manufacture

Rubber and plastics manufactured

Rubber tire manufacture

Green tire spray

Carbon black manufacture

Automobile surface coating

Beverage can surface coating

General surface coating

Paper surface coating (large source)

(small source)

Miscellaneous surface coating

Misc. (includes: industrial solvent use

and miscellaneous surface coating) d

Firebox piping

Stripper & equipment

Afterburner

Carbon adsorber

Carbon adsorber

Solvent change

Flare

Higher solids coating

Incinerator

Process change

Incinerator

Incinerator

Incinerator

Incinerator

91

87

79

95

98

98

98

98

37

69

72

20

98

98

98

95

100

42

92

83

83

90

90

88

57

70

90

91

90

75

(288)

17

722

(24)

231

3,573

32

(157)

6,222

266

1,639

316

460

14

344

1,735

942

210

355

(28)

6,198

1,647

218

267

57

(139)

53

662

492

566

1,569

4

2,634

5,176

2,348

810

492

4,277

3,549

7,722

(488)

17

270

(24)

(60)

3,573

(113)

(244)

8,762

631

302

(107)

(63)

14

331

1,351

924

193

89

(145)

2,093

454

60

74

36

(153)

15

62

258

566

830

3

1,049

6,648

1,227

602

(58)

4,277

1,837

7,722

(569)

17

26

(24)

(259)

3,573

(172)

(279)

12,025

1,188

(71)

(178)

(241)

14

314

1,122

895

189

24

(191)

(54)

137

18

22

25

(159)

3

(270)

196

566

(45)

2

727

9,146

628

436

(204)

4,277

1,094

7,722

159
Appendix A (continued).

Control COST-EFFECTIVENESS: b

Efficiency Small Medium Large

Category Name Control Technique (X) ($/ton) ($/ton) ($/ton)

New CTG’s:

Plastic parts coating 90 2,000e 2,000 2,000

Wood furniture coating 90 2,000e

2,000 2,000

Coke-oven by-product plants 90 2,000e

2,000 2,000

Automobile refinishing Incinerator 75 7,722 7,722 7,722

Federal Ccmtrols:

Architectural surface coatingd Water-base coating 25 l,000e 1,000 1,000

Commercial and consumer solvent used

90 2,000e 2,000 2,000

Stage I I :

d Vapor balance 86 l,000e 1,000 1,000

(Derived from: Battye et al., Alliance Technologies Corporation, “Cost Assessment of Alternative National

Ambient Air Quality Standards For Ozone, Draft Report,” prepared for the U.S. Environmental Protection

Agency, Office of Air Quality Planning and Standards, Contract No. 68-02-4317, October 1987.)

a Strategy Descriptions

RACT = “Reasonable Available Control Technology” on all existing stationary sources that emit more than 25

tons per year of VOC.

New CTG’s = new Control Technique Guidelines for existing stationary sources that emit more than 25 tons per

year of VOC.

Federal ControIs on selected small stationary sources of VOC (consumer and conmmercial solvents, and

architectural surface coatings).

Stage II control devices on gas pumps to capture gasoline vapor during motor vehicle refueling.

b In our analysis, the cost-effectiveness for sources that emit greater than 50 tons per year of VOC was

assumed to vary with changing source size. For sources emitting less than 50 tons per year, we assumed that

cost-effectiveness does not change with source size. “Small”, “Medium”, and “Large” refers to costeffectiveness for a typical source in these size ranges. Numbers inside parentheses denote a cost savings.

c ‘Large sources” emit more than 50 tons per year of VOC.

“Small sources” emit less than 50 tons per year of VOC.

d Sources that emit less than 50 tons per year of VOC.

e Cost-effectiveness assumed by OTA.

160