# Evaluating Ozone Contr ol Pr ograms in the Easter n United States:
Focus on the NO x Budget T rading Program, 2004United States Environment al Protection Agency Of

fice of Air and Radiation Of

fice of Air Quality Planning and Standards Of

fice of Atmospheric Programs (6204J) 1200 Pennsylvania A ve, NW Washington, DC 20460 www .ep a.gov/airtrends www .ep a.gov/airmarkets
EP A454-K-05-001 August 2005

# Contents

EXECUTIVE SUMMARY ...................................................................................................ii INTRODUCTION
............................................................................................................. iv CHAPTER 1 : Ozone and Major Contr ol Pr ograms .......................................................... 1
• Ozone Formation and Effects

................................................................................................... .............................. 1 • Reducing Ozone Pollution: Major Control Programs for NO x and VOCs

.................................................................... 2

– Mobile Sources

................................................................................................................ .............................. 3

– Industrial Processes

.......................................................................................................... ............................. 3

– The Power Industry

............................................................................................................ ............................ 4 

### CHAPTER 2 : Contr ol Pr ogram Eff ectiveness: Changes in Emissions
............................. 7
• Annual NO x and VOC Emissions in the Eastern United States

................................................................................. . 7 • Ozone Season NO x Emissions: Largest Reductions Occurred after 2002

................................................................ 7 • Focus on the NO x SIP Call: Emissions under the NO x Budget T rading Program

....................................................... 8

– Ozone Season Emission Reductions Across the Region

............................................................................ ........ 8

– Reductions in the OTC and Non-OTC States

....................................................................................... ............. 9

– Reductions from Industrial Sources

........................................................................................... ................... 10

– Reductions at the State Level

................................................................................................. ...................... 10

– Daily Emission T rends

........................................................................................................ ......................... 11 • Ozone Season Emission Reductions from All Sources

............................................................................. .............. 12 • Location of Largest Emission Reductions

....................................................................................... ...................... 12 

### CHAPTER 3 : Contr ol Pr ogram Eff ectiveness: Changes in Ozone
................................. 15
• General T rends: Changes in Ozone Concentrations since 1997

..................................................................... ........ 15 • Role of Meteorology

........................................................................................................... ................................. 16 • Focus on the NO x SIP Call: Changes in Ozone

...................................................................................................... 16

– Comparison of Power Industry NO x Emission Reductions and Ozone Changes

............................................... 19

– T rends in Ambient NO x Concentrations

.......................................................................................................... 19

– Comparison of NOx SIP Call Results to Program Design

........................................................................... ...... 21 

### CHAPTER 4 : NO x Budget T rading Pr ogram Compliance , Market Activity , and Banking
....................................................................................... 23
• 2004 Compliance Results

....................................................................................................... ............................ 23 • N O x Allowance T rading in 2004

...................................................................................................... ..................... 24 • Banking in 2004 and Flow Control Next Season

.................................................................................. ................. 25 • Continuous Emissions Monitoring System (CEMS) Results

......................................................................... ............ 26 • Compliance Options

........................................................................................................... ................................ 27 • Emission Reductions from Coal-fired Units since 2003

.......................................................................... ............... 28 

### CHAPTER 5 : Futur e NO x Reductions and Ozone Impr o vements
.................................. 31
i

# Evaluating Ozone Contr ol Pr ograms in the Eastern United States: Evaluating Ozone Contr ol Pr ograms in the Eastern United States: Focus on the NO x Budget T rading Pr ogram, 2004 

# Executive Summary

Emission Reductions

• E P Ahas developed more than a dozen programs since 1990 to limit ozone formation by reducing emissions of its key precursors: nitrogen oxides (NO x ) and volatile organic compounds (V O Cs). These programs complement state and local efforts to attain the National Ambient Air Quality Standards for ozone.

• Emission trends reflect implementation of these control programs, which began in the mid-1990s. In the eastern United States, NO x emissions decreased by 25 percent, and V O C emissions dropped by 21 percent, from 1997 to 2004.

• Control programs successfully reduced NO x emissions during the warm summer months, generally referred to as the ozone season. The most recent of those programs was the NO x SIP Call, EP A

’s regulation to reduce the regional transport of NO x and ground-level ozone in the eastern United States.

– All affected states chose to comply with the NO x SIP Call by participating in the EP A-administered NO x Budget T rading Program (NBP).

– In response to the NO x SIP Call, emissions of NO x from the power industry (one of the largest NO x sources in the country) dropped significantly after 2002. Other sources did not show this significant drop in emissions.

– After implementation of the NO x SIP Call in 2004, ozone season power industry NO x emissions were about:

› 30 percent lower than in 2003, when a limited number of states were subject to NO x SIP Call requirements;

› 50 percent lower than in 2000, before the NO x SIP Call was implemented; and

› 70 percent lower than in 1990, before implementation of the Clean Air Act Amendments.

– These reductions occurred despite a shorter-than-normal control perio d for states participating in the NBP for the first time in 2004 and despite the use of compliance supplement pool allowances—additional allowances issued to help states phase in compliance during the first two years of the NBP

. 

### Changes in Ozone

• In most of the eastern United States, reductions in ozone concentrations (adjusted for weather) more than doubled after the NO x SIP Call was implemented, beginning in 2003.

• Ozone concentrations declined where EPA expected they would. Areas with the greatest decline in ozone concentrations are near, and downwind of, areas with greatest reductions in NO x emissions.

• Because weather conditions can vary from year to year, ozone levels could be higher in years when weather is conducive to ozone formation-even when current emission control programs are working as expected. T o get a truer picture of ozone from year to year, EP A adjusts ozone levels to account for the influence of weather

. ii

### Compliance with the NO x Budget T rading Pr ogram (NBP)

• Sources choose from a variety of compliance options to meet the emission reduction targets of the NBP , including reducing generation from certain units, mo difying or optimizing the combustion process to reduce NO x formation, using add-on controls, or purchasing additional emission allowances from sources reducing below their allocations.

• In 2004, there was close to 100 percent compliance. Of the more than 2,500 units covered by the NBP in 2004, nearly all held sufficient allowances to cover their emissions. Just two units at one facility were out of compliance and subject to an automatic penalty deduction (three allowances for each excess ton of emissions).

• Overall trading activity remained robust in 2004, and allowance prices were lower and more stable than in 2003.

• The level of “banked” (i.e., saved) allowances increased significantly in 2004 as a result of additional sources participating in the NBP and the addition of compliance supplement pool allowances to states’ budgets.

• Sources in the NBP are required to use consistent rigorous monitoring procedures to measure their emissions. In 2004, both electric generating units and industrial bo ilers passed more than 98 percent of their required quality
assurance tests. 

### New Regulations, Additional Impr o vements

• While ozone remains a significant problem in many areas of the United States, EP A anticipates additional improvements, including emission reductions from:

– Continued implementation of the NO x SIP Call;

– Mobile source regulations (new passenger vehicles, heavy-duty diesel engines, and other mobile sources);

– EP A's Clean Air Interstate Rule (CAIR), which will build on the ozone season emission reductions from the NO x SIP Call. In 2015, CAIR, the NO x SIP Call, and other programs in the CAIR region will reduce power industry ozone season NO x emissions by about 50 percent and annual NO x emissions by about 60 percent from 2003 levels. CAIR will ensure that Americans continue to breathe cleaner air by dramatically reducing air pollution that moves across state boundaries in 28 eastern states and W ashington, D.C.

– State Implementation Plans to address ozone nonattainment.

iii

# Intr oduction

For more than three decades, the U.S. Environmental Protection Agency (EP A) has worked with state, local, and tribal agencies to reduce emissions that contribute to the formation of ground-level ozone. This pervasive pollutant is responsible for a number of serious health and ecological effects in many areas of the United States. Early ozone management policies focused on reducing ozone by reducing emissions of one of its key precursors, volatile organic compounds (V O Cs). V O Cs contribute to ground-level ozone formation by reacting with nitrogen oxides (NO x ) in the presence of sunlight. While ozone levels have decreased substantially since 1980, the downward trend began to slow in the early 1990s. About that time, emerging science indicated that NO x controls, in addition to V O C controls, would reduce ozone levels more effectively across large regions of the United States.
EP A responded by developing programs to reduce NO x emissions, including the NO x State Implementation Plan (SIP) Call, designed to reduce the regional transport of ozone and ozone-forming pollutants in the eastern half of the United States. All states chose to meet mandatory NO x SIP Call reductions through participation in the NO x Budget T rading Program (NBP), a market-based cap and trade program for electric generating and large industrial units. For this report, EP A analyzed the effectiveness of NO x and V O C control programs designed to reduce precursor emissions and improve ozone air quality . This report focuses specifically on progress made in reducing emissions in the eastern United States under the NO x SIP Call. Analyses of emissions in this report do not include emissions from natural sources. This report:

• Briefly describes ozone formation and its health and environmental effects, and provides an overview of the major programs designed to reduce ozone since 1990.

• Evaluates the effectiveness of the major control programs by reviewing emission reductions and comparing changes in emissions to changes in ozone concentrations.

• Compares actual changes in NO x emissions and ozone concentrations to those predicted to occur under the NO x SIP Call.

• Examines progress and compliance under the NO x Budget T rading Program, including market activity , allowance banking in 2004, and progressive flow control in 2005.

• Looks at future NO x emission reductions under programs such as mobile source controls and the Clean Air Interstate Rule (CAIR).

iv

# Chapter 1: Ozone and Major Contr ol Pr ograms

Ozone Formation and Effects Ground-level ozone pollution is common in many parts of the United States. While ozone levels in urban areas can be high because of concentrated local sources of ozone-forming pollutants, ozone levels in both urban andrural areas are affected by regional transport—the movement of ozone and/or its precursors by the wind. Because of transport, ozone levels can also be elevated in rural areas with few local emission sources. EP A revised its national air quality standards for ozone in 1997, establishing an 8-hour standard to better protectpublic health. The 8-hour standard is 0.08 parts per million (ppm). An area meets the standard if the 3-year average of the annual fourth highest daily maximum 8­ hour average concentration is less than or equal to 0.08 ppm. In April 2004, EP A designated 126 areas in the United States as nonattainment for the 8-hour ozone standard, 

### About Ground-Level Ozone
Location & Formation: Beneficial ozone occurs naturally in Earth’ s upper atmosphere (the stratosphere), where it shields the planet from the sun’ s harmful ultraviolet rays. At ground level, harmful ozone pollution forms when emissions of NO x and VOCs react in sunlight. Because ground-level ozone is highest when sunlight is most intense, the warm summer months (May 1 to September 30) are generally referred to as the “ozone season.” Health Effects: Ozone can aggravate respiratory diseases, such as asthma, emphysema, and bronchitis, and can reduce the respiratory system’ s ability to fight off bacterial infections. Even healthy people can have symptoms related to ozone exposure. Over time, ozone reduces lung function. And recent research suggests that acute exposure to ozone likely contributes to premature death. T

ransport: Wind can affect both the location and concentration of ozone pollution. NO x and VOC emissions can travel hundreds of miles on air currents, forming ozone far from the original emission sources. Ozone also can travel long distances, affecting areas far downwind. High winds tend to disperse pollutants and can dilute ozone concentrations. Light winds, on the other hand, allow pollution levels to build up and become more concentrated. Ecological Impacts: Ground-level ozone damages vegetation and ecosystems, leading to reduced agricultural crop and commercial forest yields, and increased plant susceptibility to diseases, pests, and other stresses, such as harsh weather

. Ozone also damages the foliage of trees and other plants, adversely affecting the landscape of cities and national parks, forests, and recreation areas. T

olearn more about ozone and its health impacts, please visit the AIRNow Web site at <www .airnow .gov>. For information on the health and ecological effects of ozone, go to <http://cfpub.epa.gov/ncea/cfm/ recordisplay.cfm?deid=114523>. For more about the relationship between emissions and ozone formation, visit <www .epa.gov/airtrends>.

1

### Figur e 1: 8-hour Ozone Nonattainment Ar eas based on ozone levels from 2001-2003 (see Figure 1). The vast majority of these are in the East (404 countiesor partial counties) and are home to more than onethird of all Americans. 

## Reducing Ozone Pollution: Major Control Programs for NO x and V OCs The majority of NO x and V O C emissions in the eastern United States come from three types of sources: mobile sources, industrial processes, and the electric power industry . Mobile sources and the electric power industry were responsible for 78 percent of annual NO x emissions in 2004 (see Figure 2). That same year, 99 percent of V O C emissions came from industrial processes (including solvents) and mobile sources. Emissions from natural sources, such as trees, may comprise a significant portion of total V O C emissions, especially during the ozone season. Figure 2 does not include these emissions.
EP A has developed more than a dozen control programs since 1990 to reduce ozone by decreasing emissions of NO x and V O Cs (see Table 1). These programs complement state and local efforts to improve ozone air quality and meet national standards. Nonattainment areas
Sour ce: EP A Notes:
• Map includes partial counties.

• Nonattainment ar eas as of of Apr il 2004



### Figur e 2: Sour ces of NO x and V OC Annual Emissions in the Eastern United States, 2004
NO x V OCs

Sour ce: EP A Notes:
• Emissions ar e fr om the follo wing states: Minnesota, Io wa, Missour i, Arkansas, Louisiana, W isconsin, Illinois,

T ennessee , Mississippi, Michigan, Indiana, Kentucky , A labama, Flor ida, Geor gia, South Car olina, North Car olina, Vir ginia, W est Vir ginia, Ohio , Pennsylvania, Delawar e , Maryland, Distr ict of Columbia, New Jer se y , Connecticut, Rhode Island, Massachusetts, New Hampshir e , New Y ork, Vermont, and Maine
. • The Other category for NO x emissions includes some industr ial boiler s and smaller sour ces such as r esidential fuel combustion.

• Emissions ar e pr ojected fr om EP A’s pr eliminary 2002 National Emissions In ventory (NEI).
2

### T able 1: Major EP A NOx and V OC Emission Contr ol Pr ograms since 1990

Sour ce: EP A
Notes:
• Y ears highlighted indicate implementation or compliance dates.

• Early r eductions occur pr ior to compliance date
. • In many cases, engine standar ds ar e phased in o ver multiple model year s. In some cases the time per iods o verlap.

• For fuel standar ds, year indicates when the fuel was made available
. Mobile Sour ces Emission control programs established for mobilesources in the 1990s include regulations for new vehicles and for fuels. Benefits from vehicle engine standards increase mo destly each year as older, more-polluting vehicles are replaced with newer, cleaner mo dels. Intime, these programs yield substantial emission reductions. Benefits from fuel programs generally begin as soon as a new fuel is available.
As T able 1 shows, many of the mobile source controls required since the mid-1990s apply to onroad vehicles, such as cars and trucks. EPA also has established programs to reduce emissions from nonroad mobile sources, including the Clean Air Nonroad Diesel Rule of 2004. This rule includes new engine standards that will reduce NO x emissions and particle pollution by 90 percent from nonroad diesel engines used to power equipment such as backhoes, tractors, material heavy forklifts, and airport service vehicles. The rule’s particle pollution controls will also yield V O C reductions. Industr ial Pr ocesses Large V O C reductions from industrial processes during the 1990s primarily resulted from solvent controls. These emission reductions typically occur where and when the solvent is used, such as during commercial and residential painting. In some cases, states are required to adopt Reasonably A vailable Control T

echnology (RACT) for major industrial sources of NO x and V O Cs. Implemented in the late 1990s, RACT is expected to achieve an average of 30 to 50 percent

3NO x reduction per major N O x emission source. EP A

’s New Source Review Program (not shown in T able 1) requires new industrial facilities or existing facilities making major mo difications to install Best A vailable Control T echnology to limit emissions. In addition, EP A

’s rule that controls hazardous air pollutants (commonly referred to as the “HON”) is expected to reduce emissions of V O Cs generated by the synthetic organic chemical manufacturing industry and several other processes by 1 million tons per year from 1999 levels. The Po wer Industry The power industry is one of the largest emitters of NO x in the United States. Power industry emission sources include large electric generating units and some large industrial bo ilers and turbines. There are three major control programs that affect the power industry: EP A

’s Acid Rain Program, the Ozone T ransport Commission’s NO x Budget Program, and EP A

’s NO x SIP Call. The Acid Rain NO x Reduction Pr ogram Congress established the Acid Rain Program as part of the Clean Air Act Amendments of 1990. This national program reduces sulfur dioxide (SO 2 ) and NO x emissions from coal-fired electric generating units greater than 25 megawatts (MW). The Acid Rain Program’s NO x Reduction Program is not a cap and trade program. Instead, affected sources must meet certain NO x emission rates established for different coal-fired bo iler types (emission rates are the amount of NO x emittedper unit of heat input). Companies can develop emissions averaging plans that provide compliance flexibility . The program began in 1996 for the largest NO x emitters among coal-fired electric generating units; a second phase to reduce NO x emissions from the remaining coal-fired generating units began in 2000. The OTC NO x Reduction Pr ograms The Ozone Transport Commission (OTC) was established under the Clean Air Act to help reduce summertime ground-level ozone in the Northeast and mid-Atlantic regions. In 1995, the OTC required existing stationary sources to reduce NO x emissions to meet RACT limits. From 1999 to 2002, most of the states in the OTC region implemented the OTC NO x Budget Program. This program achieved reductions in NO x fromfossil fuel-fired electric generating units and large industrial bo ilers and turbines through an ozone season (May 1through September 30) cap and trade program. The second phase of the OTC NO x Budget Program was slated to begin on May 1, 2003, but was superseded by EP A

’s NO x SIP Call. The OTC states include: Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey , New Y ork, Pennsylvania, Rho de Island, V ermont, Virginia, and W ashington, D.C. 1 The NO x SIP Call In 1995, EP A and the Environmental Council of the States formed the Ozone T ransport Assessment Group to begin addressing the problem of ozone transport in the eastern United States. In 1998, based on the group’s 

### What Is Cap and T rade? Cap and trade is a policy tool for reducing emissions from a group of sources over a broad geographic region. This approach first sets an overall cap, or maximum amount of emissions per compliance period, for all sources under the program. Authorizations to emit, known as emission allowances, are then allocated to affected sources. The total number of allowances allocated cannot exceed the cap. Under an emissions cap and trade program, sources have flexibility to choose how to meet the emission reduction requirements. A source may either limit emissions to meet the number of allowances it receives each compliance period, or it may purchase additional allowances. Sources with emissions below their limits may sell excess allowances or save (“bank”) them for future use. Sources must accurately measure and routinely report all emissions to guarantee that the overall emissions cap is achieved. Rigorous emissions monitoring ensures credibility of trading programs. For more on emissions cap and trade programs, visit <www .epa.gov/airmarkets>.

1 Maine, V ermont, and Virginia did not jo in the OTC trading program. New Hampshire is not subject to requirements of the NO x SIP Call.
4

### Figur e 3: NO x SIP Call Region, Pr ogram Implementation

Compliance Deadline May 2003 May 2004 May 2007

Sour ce: EP A
findings and other technical analyses, EPA issued a regulation to reduce the regional transport of ground-level ozone. This rule, commonly called the NO x SIP Call, requires states to reduce ozone season NO x emissions that contribute to ozone nonattainment in other states. Compliance with the NO x SIP Call was scheduled to begin in 2003. The OTC states adopted the original compliance date of May 1, 2003, in transitioning to the NO x SIP Call. In states outside the OTC region, however, litigation delayed the initial deadline until May 31, 2004. For those states, the first compliance perio d (2004) was for a shorter-than-normal ozone season (see Figure 3). In addition, litigation delayed the start date for portions of Georgia and Missouri until 2007. EP A has proposed to stay the NO x SIP Call requirements for Georgia while it responds to a petition to reconsider Georgia’s inclusion in the NO x SIP Call. The NO x SIP Call did not mandate which sources must reduce emissions; rather, it required states to meet an overall emissions budget and gave them flexibility to develop control strategies to meet that budget. All affected states chose to meet their NO x SIP Call requirements by participating in the NO x Budget T

rading Program (NBP). The NO x Budget T rading Pr ogram More than 2,500 units were affected under the NBP in 2004. These include electric generating units, which are large bo ilers, turbines, and combined cycle units used togenerate electricity for sale. As shown in Figure 4, electric generating units constitute more than 85 percent of all regulated units. The program also applies to large industrial units that pro duce electricity and/or steam, primarily for internal use. Examples of these units are bo ilers and turbines at heavy manufacturing facilities, such as paper mills, petroleum refineries, and iron and steel pro duction facilities. These units also can includesteam plants at institutional settings, such as large uni

### Key Components of the NOx Budget T

rading Program

• The NBP is a cap and trade program for electric generating units and large industrial boilers and turbines.

• The emissions budget sets a cap on emissions at a level chosen to help states meet their air quality goals.

• The NO x emissions market allows sources to trade (buy and sell) allowances throughout the year

. • At the end of every ozone season, each source must surrender sufficient allowances (each allowance represents one ton of emissions) to cover its ozone season NO x emissions. This process is called annual reconciliation. • If a source does not have enough allowances to cover its emissions, EP A will automatically deduct allowances from the following year’ s allocation at a 3:1 ratio.

• If a source has excess allowances because it reduced emissions beyond required levels, it can sell the unused allowances or “bank” (i.e., save) them for use in a future ozone season.
• T o accurately monitor emissions, sources use continuous emissions monitoring systems (CEMS) or other approved monitoring methods under EP A’ s stringent monitoring requirements (40 CFR Part 75).

5versities. Some states have included other types of units, such as petroleum refinery process heaters and cement kilns.
T

wo criteria are part of determining whether a unit is affected under the NBP: the unit must be fossil fuel-firedand must meet specific size thresholds. For electric generating units, the program generally applies to any unit connected to a generator with a nameplate capacity (the power output in MW that the machine is designed to pro duce) greater than 25 MW. Some OTC states, however, include units connected to generators with at least 15 MW capacity . For industrial units, the NBP applies to units with a maximum design heat input capacity greater than 250 million British thermal units per hour (mmBtu per hr). 

### Figur e 4: Number of Units in the NO x Budget T

rading Pr ogram by T ype , 2004

Sour ce: EP A
Note: T otal aff ected units in 2004 = 2,570



### State T rading Budgets, Allowance Allocations, and Compliance Supplement Pool (CSP) Allowances

EP

A provided broad discretion to states as to how they could allocate allowances from their trading budget to affected sources. One option was to allocate allowances based on each source’ s share of statewide ozone season heat input (i.e., fuel use). Another option was based on each source’ s share of ozone season output (e.g., generation) to reward sources that generate more energy with less fuel input. States could also set-aside allowances for new sources or as incentives for energy efficiency and renewable energy programs. In addition to their NO x budgets, states received additional allowances to distribute from the Compliance Supplement Pool (CSP). EP A created the CSP allowances to address concerns that initial efforts to comply with the NO x emissions cap could have too many primary electric generating units out of operation at the same time to install pollution control retrofits, which could have adversely affected electricity supply reliability

. The CSP allowances help states to phase-in compliance during the first two years of the trading program and allow sources to limit units out of service at critical times during the year

. States were allowed to distribute their CSP allowances based on early reductions in NO x emissions, on the basis of demonstrated need, or on some combination of the two methods. The CSP allocation was a one-time, up-front allocation. For the states that began to comply with the NO x SIP Call in 2003 (states that had been a part of the OTC trading program), all CSP allowances were distributed as vintage year 2003 allowances and replaced existing banked OTC allowances. The non-OTC states distributed CSP allowances as vintage year 2004 allowances. The vintage is the first year an allowance can be used for compliance (i.e., deducted to cover emissions). For example, almost all 2004 vintage allowances may be used for compliance beginning in 2004, or for any year thereafter

. The only exception is the 2004 CSP allowances, which may only be used for compliance through the 2005 ozone season.

6

# Chapter 2: Contr ol Pr ogram Eff ectiveness: Changes in Emissions

Figur e 5: Annual Emissions in the Eastern United States, 1990-1995 and 1997-2004

Sour ce: EP A Notes:
• Emissions ar e fr om Minnesota, Io wa, Missour i, Arkansas, Louisiana,

and states east.

• The emissions data used in this r eport ar e measur ed or estimated values fr om EP A’s National Emissions In ventory (NEI). Starting in 1997, the NEI incorporated po wer industry data measur ed by the Continuous Emissions Monitor ing System (CEMS). For 2002, the pr eliminary version of the NEI was used, which includes the 2002 CEMS data, but does not include 2002 data for other sour ces submitted by state , local, and tr ibal air agencies. For this analysis, EP A used CEMS data for the po wer industry for 2003 and 2004. Emissions for other sour ces for that per iod wer e estimated by interpolating between the 2002 pr eliminary NEI data and a pr ojected 2010 emission in ventory developed to support the Clean Air Inter state Rule
. • 1996 is not r epr esented in the graphs because ther e was a change in

the method used to collect and estimate emissions, particularly fo r NO x emissions fr om stationary sour ces such as the po wer industry
. pared annual and ozone season emission trends for all NO x and V O C sources from 1997 through 2004. For all emission categories, except power industry N O x , the ozone season trend is similar to the annual trend. Figure 6 shows a comparison of annual and ozone season N O x emissions from the power industry . From 1997 to 2002, the trend in ozone season emissions is similar to the annual trend. However, in 2003 and 2004, ozone season NO x emissions show a greater reduction. These larger EPA and state, local, and tribal agencies have implemented several programs that reduce N O x and V O C emissions. In order to assess the effectiveness of major control programs, EP A examined trends in N O x and V O C emissions since 1990, looked at when and where the reductions occurred, and then focused on progress made under the NO x SIP Call in 2004. 

## Annual NO x and V OC Emissions in the Eastern United States Figure 5 shows trends in annual N O x and V O C emissions for two time perio ds: 1990 to 1995 and 1997 to 2004. In the first perio d, control programs for mobile sources and industrial processes gradually reduced both NO x and V O C emissions, with N O x emissions decreasing by 9 percent and V O C emissions decreasing by 7 percent. The second perio d reflects implementation of many control programs mandated by the 1990 Clean Air Act Amendments. The results of these programs are evident in emission trends from 1997 to 2004: N O x emissions decreased by 25 percent and V O C emissions decreased by 21 percent. It is important to note that a significant portion of total V O C emissions can come from natural sources, such as trees, especially during the ozone season. For example, EPA estimates that nearly 60 percent of total ozone season V O C emissions in 2001 were from natural sources. These emissions are not shown in Figure 5. 

## Ozone Season NO x Reductions, 2003 and 2004 Because ozone levels are highest during the summer months, it is important to evaluate N O x and V O C emission reductions during that time perio d. EPA com7

### Figur e 6: Po wer Industry NO x Emissions in the Eastern United States, Annual and Ozone Season, 1997–2004

Sour ce: EP A Note: Emissions ar e fr om Minnesota, Io wa, Missour i, Arkansas, Louisiana, and states east.
reductions are attributable to N O x SIP Call controls which were applied in the summers of 2003 and 2004. (For details about the types of controls used, see Chapter 4, Compliance and Market Activity , page 23.) 

## Focus on the NO x SIP Call: Emissions under the NO x Budget T rading Program This section assesses progress under the N O x Budget T

rading Program (N BP) by comparing N O x emission levels in 2004 (the second year of the NBP) to levels in 1990, 2000 (baseline years), and 2003. Therefore, these results include emissions from affected sources in states included in the N O x SIP Call in 2004 (see figure 3). 2 In 2003, all affected sources in the NBP region conducted ozone season emissions monitoring, but only the states previously in the OTC NO x Budget Program were subject to the emission reduction requirements of the program. 3 All sources subject to the NO x SIP Call in 2004 were required to have enough allowances to cover emissions during the 2004 ozone season. Sources in the OTC states were required to comply for the full ozone season (May 1 to September 30) in 2004. The compliance perio d did not begin until May 31 in the non-OTC states. Ozone Season Emission Reductions Acr oss the Region Figure 7 shows the total ozone season NO x emissions for the NBP region in 2004 compared to 1990, 2000, and 2003. In 2004, NBP sources emitted about 593,000 tons of NO x , reducing emissions by nearly 30 percent from 2003, 50 percent from 2000, and nearly 70 percent from 1990. Many of the NO x reductions since 1990 are a result of programs implemented under the Clean Air Act such as the Acid Rain NO x Reduction Program, and other state, local, and federal programs. The significant decrease in NO x emissions after 2000 reflects additional reductions that show the impacts of the NO x SIP Call.



### Figur e 7: Ozone Season Emissions under the NO x Budget T rading Pr ogram

Sour ce: EP A

2 For further information on estimating baseline emissions, refer to the NO x Budget T rading Program 2003 Progress Report at

www .epa.gov/airmarkets/fednox

3 In 2003, North Carolina sources were not required to monitor, although many sources did so voluntarily . The lack of 2003 data f or certain North Carolina sources has a negligible effect on the results in this report.

8Emission Reductions in the OT C and Non-OTC States In light of the different control perio ds in 2004, it isuseful to look at total NBP emissions as well as a breakdown of emissions by the two groups of states (OTC and non-OTC states). States that began compliance for the first time in 2004 (non-OTC states) received compliance supplement pool (CSP) allowances. Figure 8 presents the sum of the 2004 trading budgets (OTC states) and the trading budget with CSP allowances (non-OTC states). The budgets also reflect some allowances provided to opt-in 4 units in New Y ork, Ohio, and W est Virginia. For a more thorough description of trading budgets and allowance allocations, see page 6. As Figure 8 shows, the CSP allowances increase the trading budget significantly in the non-OTC states. Thetrading budget levels for the OTC states show no difference, because the OTC states received all of their CSP allowances in 2003. Figure 8 also presents the 2004 ozone season results both for the full ozone season (OTC states) and the shortened control perio d for the non-OTC states. 

### Baseline Y ears for Measuring Progress Under the NOx Budget T rading Program One measure of progress under the NBP is whetheremissions under the program meet the emission budgets established for the states. Also, it is helpful to understand how emissions under the program compare to emissions prior to the program. EP A has chosen two baseline years for measuring progress under the NBP:
• 1990, which represents emission levels before the implementation of the 1990 Clean Air Act Amendments.

• 2000, because most of the reductions required under the 1990 Clean Air Act Amendments had already occurred by this time, but sources were not yet implementing the NBP

.

During the OTC N O x Budget Program, emissions were less than allocated allowances in every year of the program (1999 to 2002). That trend has continued under the NBP in both 2003and 2004. In 2004, ozone season N O x emissions in theOTC states were approximately 132,000 tons, about 10 percent less than the sum of the 2004 trading budget for those states, and more than 30 percent less than their 2002 emissions. 

### Figur e 8: NO x Budget T rading Pr ogram: 1990, 2000, 2003, and 2004 Ozone Season Emissions, and the 2004 T rading Budgets

Sour ce: EP A

Note: 2004 allo wances include 2004 T rading Budgets and 2004 Compliance Supplement Pool (CSP) allo wances.

4 An opt-in unit is a unit not covered by the applicability provisions of a program that requests to voluntarily enter the progra m and, because it meets specific program requirements (e.g., continuous emission monitoring capability), is approved to participate.

9

### Figur e 9: Compar ison of A verage Monthly NO x Emission Rates, OTC and Non-OTC States, 2004

Sour ce: EP A Note: A verage monthly emission rates ar e based on total r eported NOx mass emissions and heat input for each applicable month for all participating units.
EP A anticipated that the states outside the OTC region would achieve only mo dest reductions in 2004, because of the shorter control perio d and the CSP allowances distributed that year. However, the sum of emissions in these states for the full ozone season were more than 30 percent below 2003 levels. In addition, emissions for the 2004 control perio d (May 31 to September 30) were below the sum of their 2004 trading budgets (the budgets without CSP allowances). Figure 9 shows that, on average, the non-OTC states reduced their N O x emission rates to nearly the same level as the OTC states. Their average emissions rate in May (prior to the control perio d) was considerably higher. These results indicate that the non-OTC states made significant progress toward installing adequate controls to meet their trading budget levels in 2005. Emission Reductions fr om Industr ial Sour ces Collectively, affected NBP industrial units reduced emissions approximately 25 percent from 2003 to 2004, despite the shorter 2004 control perio d. Emissions from these sources in the full 2004 ozone season were about40,000 tons, compared to 53,000 tons for the same perio din 2003. Although industrial units have achieved reductions, they are much less likely than electric generating units to use add-on control devices, such as selective catalytic reduction (SCR). As a result, these units tended to have higher ozone season N O x emission rates in 2004 than the full population of affected units (about 0.25 lb per mmBtu compared to 0.21 lb per mmBtu). However, the 2004 average ozone season N O x emissions rate (0.25 lb per mmBtu) among industrial units decreased from the 2003 rate of approximately 0.38 lb per mmBtu. Emission Reductions at the State Level T

wo non-OTC states—Alabama and Michigan—had control perio d emissions that exceeded their trading budgets in 2004. However, all non-OTC states had 2004 control perio d emissions below their 2004 trading budgets when CSP allowances were included (see Figure 10).Although the ozone season emissions in most of the individual OTC states were below their trading budgets in 2004 (see Figure 10), emissions in Pennsylvania and Maryland were higher . For Pennsylvania (emissions exceeded allocations by 1,300 tons), the amount reflects about 3 percent of the state’s total budget. This type of variability can be expected in a regional trading program and can reflect a number of different factors, including company-specific compliance decisions. Emissions in Maryland exceeded allocations by 4,500 tons (about 30 percent greater than budget levels) andincreased slightly from 2003 to 2004. These results indicate a clear decision to purchase a significant number of allowances in 2004 as opposed to controlling emissions close to budget levels. In future years, the situation in Maryland likely will change as the result of a federal consent decree. 5

5 By 2008, under a federal consent decree, one of the companies with affected units in Maryland will be required to cap emissions from three Maryland

plants and one Virginia plant to 6,000 tons per ozone season. The three Maryland plants alone emitted more than 13,000 tons in the 2004 ozone season. The emissions cap in this consent decree should reduce emissions from existing plants in Maryland well below budget levels.
10

### Figur e 10: Ozone Season NO x Emissions: 1990, 2000, and 2004 Emissions and T rading Budgets

Sour ce: EP A

Notes:
• The Non-OTC states ar e shaded.

• In 2004, the contr ol per iod for non-OTC States was fr om May 31 thr ough September 30.
Daily Emission T r ends Studies indicate that many of the health effects associat- 

### Figur e 11: ed with ozone are linked to daily exposures. The 8-hour 

### Daily Emissions Under the 

### NO x Budget ozone standard was developed to protect against such 

### T rading Pr ogram, 2003 and 2004 exposures. Although the NBP ensures significant regional N O x reductions throughout the course of the ozone season, there have been concerns that a seasonal cap would not sufficiently reduce short-term, peak N O x emissions that can occur on hot, high electricity demand days when ozone formation is often a concern. Figure 11 compares daily NO x emissions for 2003 versus 2004 for the NBP region. The results show that the NBP significantly reduced both the average and highest daily emission levels. Average emissions during the control perio d in 2004 (May 31 to September 30), decreased nearly 35 percent from the same perio d in Source: EP A 2003. The highest daily emissions in the 2004 control

11perio d were more than 30 percent lower than the highest daily emissions during the same perio d in 2003.The NBP has had a significant impact on daily emissions (see Figure 11). The highest total daily emissions in 2004 rarely exceeded the lowest total daily emissions in 2003 except from May 1 to May 30, when the 2004 control perio d was not in effect for non-OTC states. These results show that, while reducing total emissions in 2004, the trading program also reduced peak daily emission levels. 

## Ozone Season Emission Reductions from All Sources In response to the N O x SIP Call, the power industry dramatically reduced ozone season N O x emissions after 2002. Other major N O x and V O C source categories do not show this significant drop in emissions. As Figure 12 shows, ozone season N O x emissions from the power industry dropped 6 percent per ozone season, on average, from 1997 to 2002. Reductions were much greater after 2002—an average of 19 percent per ozone season from 2002 to 2004. Onroad mobile and other categories show continuing N O x emission reductions; however, those reductions are not as dramatic after 2002 as the reductions from power industry sources. Similarly , V O C emissions dropped somewhat between 1997 and 2002, but there were few additional reductions after 2002 (Figure 13). V O C emissions from onroad mobile sources, for example, dropped an average of 5 percent per ozone season for both time perio ds. 

## Location of Largest Emission Reductions Knowing the location of N O x and V O C emission reductions also helps EP A understand the effectiveness of emission control programs. Figure 14 shows ozone season N O x emission reductions between 1997 and 2004. The largest reductions occurred in the central portion of the eastern United States.
W ithin this region, Illino is, Kentucky , North Carolina, Ohio, Pennsylvania, and T ennessee each experienced NO x emission reductions greater than 110,000 tons. Following close behind were Alabama, Indiana, Michigan, New Y o rk, and W est Virginia—all of which had reductions greater than 73,000 tons.



### Figur e 13: Ozone Season V OC Emissions in the Eastern United States by Category , 1997, 2002, 2004

Sour ce: EP A 

### Figur e 12: Ozone Season NO x Emissions in the Eastern United States by Category , 1997, 2002, 2004

Sour ce: EP A
Note: Other includes emissions fr om nonr oad, industr ial pr ocesses, and small po wer industry sour ces. Note: Other includes emissions from nonroad, po wer industry , and nonsolvent industr ial processes.

12Figure 15 shows the location of ozone season N O x reductions for the power industry and onroad mobile 

### Figur e 14: sources. Overall, power industry sources accounted for 

### Ozone Season NO x Emissions Reduced, larger N O x emission reductions than did onroad mobile 

### 1997 vs. 2004 sources. Note the following:

• States along the Ohio River V alley from Pennsylvania to Tennessee generally experienced the largest reductions in power industry NO x emissions. Emissions dropped the most in Ohio (153,000 tons), Illino is (111,000 tons), and Kentucky (104,000 tons).Pennsylvania achieved similar reductions by implementing control measures prior to 1997.

• Emission reductions from onroad mobile sources were smaller than from the power industry and occurred primarily in states with large urban areas.

• No state realized reductions greater than 42,000 tons from onroad mobile sources. Sour ce: EP A
Note: Darker states sho w lar ger NOx r eductions. 

### Figur e 15: Ozone Season NO x Emissions Reduced, Po wer Industry and Mobile Sour ces, 1997 vs. 2004

Sour ce: EP A Notes:
• Due to earlier r eductions pr ior to 1997, Pennsylvania r educed its emissions by the same magnitude as Ohio
. • Darker states sho w lar ger NO x r eductions.

• Vermont sho wed an incr ease of about 45 tons of NO x fr om po wer industry sour ces.

13Figure 16 shows where reductions in ozone season V O C emissions occurred between 1997 and 2004. Reductions in V O C emissions were neither as large (in tons) as reductions in N O x emissions between the two years, nor were they concentrated in the same states (see Figure 14). The largest reductions occurred in New Y ork (99,000 tons), Illino is (97,000 tons), and Ohio (88,000 tons).



### Figur e 16: Ozone Season V OC Emissions Reduced, 1997 vs. 2004 Natural Sources of VOCs Emissions generated by human activity account for only a portion of total VOC emissions. VOCs also come from trees and other vegetation. In many parts of the world, VOC emissions from natural sources are larger than manmade VOC emissions. In the eastern United States, for example, nearly 60 percent of the total 2001 ozone season VOC emissions came from natural sources. VOC emissions from natural sources are higher on warm sunny days, which also provide the best conditions for ozone formation. While VOCs from naturalsources do contribute to ground-level ozone formation, it is difficult to assess the impact changes these emissions have on ozone concentrations. EP

A did not analyze VOC emissions from natural sources for this report, as the amount of data available was too limited. As more data become available in the future, EP A will analyze the effects of natural VOC emissions on ozone formation.

Sour ce: EP A
Notes:
• Rhode Island sho wed an incr ease of about 872 tons.

• Figur e does not include emissions fr om natural sour ces.
• Darker states sho w lar ger V OC r eductions.

14

# Chapter 3: Contr ol Pr ogram Eff ectiveness: Changes in Ozone

Ozone Monitoring Networks For this report, EP A assembled data for 29 urban areas from the Air Quality System (A QS) and 34 rural sites from the Clean Air Status and Trends Network (CASTNET) to provide a more complete picture of the nation’ s air quality than would be otherwise possible. Sufficient ambient and meteorological data for these sites were available to perform detailed analyses of air quality changes over time. Air Quality System (AQS) A QS is EP A’ s repository for state and local data from monitoring networks specifically designed to assess air quality trends and to support regulatory programs, such as nonattainment area designations and development of State Implementation Plans. These networks include the State and Local Air Monitoring Stations (SLAMS) and National Air Monitoring Stations (NAMS). There are more than 700 SLAMS/NAMS monitoring sites in the eastern United States. For more information, see <www .epa.gov/ttn/airs/airsaqs>. Clean Air Status and T r ends Netw ork (CASTNET) CASTNET is a national network of rural monitoring sites, with more than 50 sites in the eastern United States. EP A established the network primarily to provide data needed to track and evaluate national and regional air pollution control programs. These data provide information necessary to study and investigate the effects of atmospheric pollution on sensitive ecosystems, particularly those effects caused by long-range transport of emissions from regional sources. Data gathered from the network are compiled in a central database and made available on EP A’ s CASTNET W eb site at <www .epa.gov/castnet>. 

### Urban and Rural Locations

Sour ce: EP A Urban ar ea (A QS) Rural site (CASTNET)

Note: Urban ar eas r epr esent multiple monitor ing sites. Rural ar eas r epr esent single monitor ing sites. T

o better understand how major control programs affect ozone, EP A looked at overall changes since 1997, and then focused on ozone improvements after 2002 (after implementation of the NO x SIP Call). These analyses also consider the impact of weather, because variationsin weather conditions play an important role in determining ozone levels. This chapter examines the results of these analyses in relation to the original N O x SIP Call program design by comparing the anticipated changes in emissions and ozone to actual changes. 

## General T rends: Changes in Ozone Concentrations since 1997 Like N O x and V O C emissions, ozone concentrations in urban and rural areas have decreased between 1997 and 2004 in response to control programs. Figure 18 shows the percent reductions (adjusted for weather conditions) in seasonal ozone. Seasonal ozone was calculated as the average of daily maximum 8-hour ozone concentrations from May 1 through September 30. Ozone reductions

15were greater than 10 percent across a broad geographic region; the average reduction was 14 percent. 

## Role of Meteorology
V

ariations in weather conditions play an important role in determining ozone levels. Daily temperature, relative humidity, and wind speed can affect ozone levels. In general, warm dry weather is more conducive to ozone formation than cool wet weather . EP A uses a statistical

mo del to account for the impact of weather on ozone concentrations. Because weather varies over space and time, this adjustment provides a better estimate of the underlying ozone trend and the impact of emission changes (see “Meteorology Matters” on page 17).
T

o illustrate the overall impact of weather on ozone levels in outdoor air, EP A compared changes in ozone before and after adjusting for weather, as Figures 17 and 18 show. Adjusting for weather made only a small difference (1 percent) in overall ozone change in the eastern United States—an average reduction of 13 percentbefore adjustment, compared to 14 percent after adjust

### Figur e 17: Per cent Reduction in Seasonal 8-Hour Ozone , 1997 vs. 2004 (Not Adjusted for Meteor ology)

Sour ce: EP A ment. Some states showed notable differences. For example, adjusting for weather at sites in North Carolina, Virginia, and eastern T ennessee resulted in significantly smaller reductions, while adjustments in Ohio, Pennsylvania, and W est Virginia showed larger ozone reductions. 

## Focus on the NO x SIP Call: Changes in Ozone
EP A examined geographic patterns and ozone behavior before and after the N O x SIP Call, and then compared EP A

’s projections to what actually occurred.
T

oanalyze ozone changes, EP A selected two baseline years—1997 and 2002. These two years were selected to

co incide with the perio d of NO x reductions attributable to the Acid Rain Program and the OTC NO x Budget Program (1997 through 2002) and the implementation of the NO x SIP Call (2002 through 2004). Ozone improvements were larger after implementation of the N O x SIP Call. The average reduction in ozone 

### Figur e 18: Per cent Reduction in Seasonal 8-Hour Ozone , 1997 vs. 2004

(Adjusted for Meteor ology)

Sour ce: EP A

Note: Mar gin of err or is ± 5 per cent. Note: Mar gin of err or is ± 5 per cent.

16

### Meteorology Matters Meteorology plays a major role in both the formation and transport of ozone. For example, the photochemical reactions that transform emissions of NO x and VOCs into ozone are complex and require warm temperatures and dry conditions. These graphics illustrate how the summers of 1997, 2002, and 2004 compare with historical records ( a 30-year average using data from 1971 to 2000) for temperature and precipitation in the eastern United States. Note: Meteorology can vary significantly from one site to the next.

Sour ces: National Oceanic and Atmospher ic Administration (NOAA), EP A

17

### Figur e 19: Percent Reduction in Seasonal 8-Hour Ozone Per Y ear , 1997-2002 (Adjusted for Meteorology)

Sour ce: EP A 

### Figur e 20: Percent Reduction in Seasonal 8-Hour Ozone Per Y ear , 2002-2004 (Adjusted for Meteorology)

Sour ce: EP A
Notes:
• Mar gin of err or is ± 2 per cent.
Note: Mar gin of err or is ± 1 per cent. between 1997 and 2002 was about 4 percent (adjusted for weather), compared with more than 10 percent between 2002 and 2004. Meteorological adjustment wasespecially important for this analysis because of the significant difference in the ozone-forming potential between 2002 and 2004. The difference in ozone levels between 2002 and 2004 was about 17 percent before adjusting for weather, compared with about 10 percent after adjustment.Figures 19 and 20 illustrate how reductions in ozone levels changed before and after the N O x SIP Call (afteradjusting for weather). These figures show average percent changes per ozone season between two time perio ds: 1997 through 2002 (the five-year perio d before the N O x SIP Call) and 2002 through 2004 (the twoyear perio d after the NOx SIP Call). This analysis of emissions and ozone shows that the N O x SIP Call achieved an additional 4 percent reduction per ozone season. Before the N O x SIP Call was in place, ozone declined about 1 percent per ozone season in most areas • Locations with ozone changes gr eater than 3 per cent per ozone season ar e highlighted in r ed. in the East, although some states (Kentucky and Florida) realized average reductions as large as 3 percent per ozone season (see Figure 19). After implementation of the N O x SIP Call (see Figure 20), the ozone reduction was larger—5 percent per ozone season on average—with many areas exceeding 5 percent.
EP A expects that N O x and V O C emissions will continue to decrease in 2005. Despite these improvements, ozone levels in 2005 could be higher than in 2004, depending on weather conditions. (W eather conditions in 2004 were not conducive to ozone formation.) T o accurately estimate trends in ozone air quality, meteorological effects must be taken into account.

18

### Figur e 21: Reductions in Ozone Season Po wer Industry NO x Emissions and 8-Hour Ozone , 2002 vs. 2004

Mar gin of err or is + 5 per cent.
Sour ce: EP A Notes:
• Darker states sho w lar ger NO x r eductions.

• Arkansas (268 tons), New Hampshir e (611 tons), and Vermont (16 tons) sho w small incr eases in ozone season emissions fr om 2002 to 2004.
Compar ison of Po wer Industry NO x Emission Reductions and Ozone Changes Figure 21 shows the relationship between reductions in power industry N O x emissions and reductions in ozone after implementation of the N O x SIP Call. Generally , there is a strong association between areas with the greatest N O x emission reductions (such as the Midwest)and downwind sites exhibiting the greatest improvement in ozone. This suggests that the effect of N O x transport has been reduced in the eastern United States. While this report does not attribute all ozone reductions after 2002 to the N O x SIP Call, it does show that the NO x SIP Call played a major role in reducing ozone concentrations. T r ends in Ambient NO x Concentrations Ambient concentrations of N O x gases have fallen as NO x emissions have declined. EP A examined data from both urban and rural monitoring sites, looking at N O x from air quality monitors in the AQS network and total nitrate measurements from CASTNET sites. The results indicate that ambient concentrations of ozone-forming gases and total particulate nitrates have decreased over the past seven years, further evidence that N O x emissions have been reduced.

19

### Ozone Reduction in Rural Areas Shows Regional Improvements The primary goal of the NO x SIP Call is to reduce regional transport of ozone across state boundaries by reducing NO x . EP

A’ s Clean Air Status and Trends Network (CASTNET) provides long-term data on ozone air quality at more than 50 monitoring sites in rural areas across the eastern United States. The monitoring information collected at rural sites is a good indicator of background ozone concentrations, because rural areas are not as influenced by local emissions sources. The rural network is particularly relevant to assessing progress under the NO x SIP Call, because it represents levels of ozone and precursor gases that are being transported from one area to another

. Due to changing weather conditions, air quality trends often show high year to year variability over time. Some of this variability can be overcome through the use of consistent and continuous long-term monitoring data. The results presented here show the variability over time in actual observed ozone concentrations at rural sites on a regional level. The figure below shows a gradual decline in seasonal average 8-hour daily maximum ozone levels from 1997 to 2004 for all four eastern regions. The largest improvements occurred after 1998 and again after 2002. The downward trend is especially evident in the Southeast, which has experienced a steady decline in ozone in rural areas since 1998. These results have not been adjusted for weather; however, the overall downward trend is consistent with trends that have been adjusted for the influences of weather

.


### Rural Seasonal A verage 8-hour Daily Maximum Ozone by Region, 1997-2004

Sour ce: EP A

Note: Ozone concentrations ar e in parts per billion (ppb)

20

### Figur e 22: Ozone Season Po wer Industry NO x Emissions Reduced, Anticipated and Actual

Sour ce: EP A
Notes:
• Darker states sho w lar ger NO x r eductions.

• Per cent of total NO x emissions r educed is an individual state’s emissions r educed, divided by total r eductions acr oss all states (in tons).

• Anticipated r esults ar e the estimated diff er ence in po wer industry emissions between the 2007 base case and 2007 with the NOx SIP Call for the days modeled, which r epr esent the ozone season.

• Actual r esults ar e the diff er ence in state total ozone season po wer industry emissions between 2002 and 2004, as r e ported to EP A. Compar ison of NO x SIP Call Results to Pr ogram Design EP A uses air quality mo dels to help predict the impacts of new or proposed programs (see “Estimating the Impact of Proposed Control Programs” on page 22). For the N O x SIP Call, EP A used mo dels to estimate changes in N O x emissions and their effects on ozone levels. Figure 22 shows the state-by-state percentage of total N O x emission reductions anticipated from the NO x SIP Call and the actual reductions achieved by the power industry between 2002 and 2004. Because the majority of the states subject to the N O x SIP Call were required to meet their emission caps by 2004, EP Aexpects few additional reductions after 2004 as the compliance supplement pool is used up, and in response togrowth in fossil fuel generation to meet increasing electric demand. Figure 22 shows that actual N O x emission reductions occurred where anticipated. The largest reductions took place in states along the Ohio River V alley . States are color-co ded based on the percent of total emissions reduced, which is calculated as an individual state’s emission reductions, divided by total reductions across all states (in tons). Anticipated reductions are based on tons reduced across days mo deled, which represent the ozone season. Actual reductions are based on tons reduced across ozone season days.

21

### Figur e 23: Per cent Reductions in Seasonal 8-Hour Ozone , Anticipated and Actual

Sour ce: EP A <5 5 - 9.9 10 - 14.9
> 15

Notes:
• E P Aused pr ojections of 2007 emissions—both with and without the NO x SIP Call—to evaluate the rule’s impact on ozone concentrations. Although EP

A’s modeling used 2007 as a base year , the r egulation r e quir ed the major ity of these r eductions to be implemented pr ior to May31, 2004 (in all aff ected states, except portions of Missour i and Geor gia).

• For this r eport, EP A compar ed model-pr edicted changes in seasonal average 8-hour ozone to actual ambient changes, befor e and aft er the NO x SIP Call. Similarly , Figure 23 illustrates where ozone reductions the ozone season. As with N O x emissions, the anticiwere anticipated and where actual ozone reductions pated and actual changes in ozone generally are similar were achieved. Both maps use average daily maximum (e.g., both show largest reductions along the Ohio River 8-hour ozone concentrations. Anticipated improve- V alley), indicating that the N O x SIP Call appears to ments are based on mo del predictions, and actual have achieved its goal of reducing ozone in the eastern improvements are based on measurements taken during United States. 

### Estimating the Impact of Proposed Control Programs

EP

A uses air quality models to predict how emissions from a specific source or combination of sources will contribute to ozone concentrations at downwind sites. Using estimates of hourly emissions and meteorology , t hese models simulate the physical and chemical processes that contribute to ozone formation and transport. These models allow EP A to testhypotheses about how ozone levels will respond to reductions in VOC and NO x emissions resulting from an individual control program or combination of control programs. Photochemical gr id models simulate atmospher ic chemistry and transport thr oughout the geographic ar ea of inter est.

22

# Chapter 4: NO x Budget T rading Pr ogram Compliance , Market Activity ,

window after the end of the control perio d to moveallowances between accounts (and to buy or sell additional allowances) to ensure their emissions do not exceed allowances held. After the two-month perio d, allowances may not be transferred into or out of these accounts while EP A reconciles emissions with allowance holdings for program compliance. Nearly all of the NBP sources that participated in 2004—both electric generating units and industrialunits—held sufficient allowances to cover their emissions at the time.
EP A performed reconciliation and identified a single facility with two units that had an allowance deficiency of nine allowances. In cases where the source does nothold enough allowances to cover its emissions, the program requires an automatic penalty deduction (three allowances for each excess ton of emissions) from the 

# and Banking

A review of the second year of cap and trade under the NO x Budget T rading Program (NBP) shows that the market continues to mature. In 2004, for the first time, a substantial number of sources in 11 states began to comply with the emission reduction requirements underthe program. Many of these sources had to make significant reductions to achieve compliance, and the market appears to have played a significant role as participants determined what control strategies to pursue and on what timetable. At the same time, a number of units added controls to meet emission reduction requirements in the non-OTC states between the end of the 2003 and the beginning of the 2004 ozone season. This chapter examines compliance under the NBP in 2004 and examines trends in this maturing market, including those in allowance pricing and transactions. It also addresses how the high level of banking in 2004 will affect future restrictions on the use of banked allowances for compliance. In addition, this chapter reviews the monitoring and control metho ds employed by sources to meet program requirements. 

## 2004 Compliance Results Under the NBP , sources must hold sufficient allowances to cover their ozone season emissions each year. Sources can maintain the allowances in compliance accounts (established for each unit) or in an overdraft account (established for each facility with more than one unit).The overdraft account allows greater flexibility in “bubbling” between units, managing banked allowances from previous years, managing transferred allowances from other sites, and managing allowances purchased from other NBP participants. The sources have a two-month

23source’s allocations for the next control perio d. T able 2 summarizes the allowance reconciliation process for 2004. 

## NO x Allo wance T rading in 2004 Allowance trading generally comprises three main types of transfers:
1. Transfers within a company or between related entities (e.g., holding company transfers to a small operating subsidiary).
2. T ransfers between separate economic entities. These transfers are categorized broadly as “economically significant trades.”
3. Transfers from or to the state as allowance allocations or allowance surrenders. In 2004, economically significant trades represented approximately 40 percent of the total transfers between entities other than a state. The economically significant trades provide the strongest indicator of true market activity , because they represent an actual exchange of assets between unaffiliated participants. There were more than 230,000 allowances involved in economically significant trades in 2004, slightly lower than in 2003. However, overall trading activityremained robust. As in the earlier OTC trading program, industrial sources have actively traded allowances.These sources traded more than in 2003 and participated in approximately 13 percent of the economically significant trade volume.



### T

able 2: NO x Allo wance Reconciliation Summary—2004

T o t a l A l l o w a n c e s H e l d f o r R e c o n c i l i at i o n 6 7 6 , 5 7 4
Allowances Held in Compliance and Overdraft Accounts Allowances Held in Other Accounts* 609,249 67,325

Allowances Deducted for 2004 Emissions T

ermination of 2003 Early Reduction Credit (or Compliance Supplement Pool) Allowances** 468,824

125
B a n ke d A l l o w a n c e s Allowances Held in Compliance and Overdraft Accounts Allowances Held in Other Accounts*** 2 0 7 , 6 2 5 133,857 73,768
P e n a l ty A l l o w a n c e s D e d u c t e d * * * * ( f r o m f u t u r e y e a r a l l o w a n c e s) 2 7

Sour ce: EP A

* Other Accounts r e f e rs to general accounts in the NO x Allo wance T racking System (NA TS) that can be held by any sour ce , individual, or other or ganization, as well as state accounts. ** Compliance Supplement Pool (CSP) allo wances can only be used for tw o year s. In the OT C states, CSP allo wances not used for r econciliation in 2003 or 2004 have been r etir ed permanently
. *** T otal includes 6,477 new unit allo wances r eturned to state holding accounts. **** These penalty deductions ar e made fr om futur e vintage year allo wances, not 2004 allo wances.

24During certain perio ds, the price for N O x allowances can reflect market uncertainties as companies evaluate ongo ing trends in controlinstallations, energy demand, and other external factors that affect the overall costs of control. In addition, program elements such as progressive flow control and the retirement of compliance supplement pool allowances enter into transfer decisions, as do questions about the integration of the NBP with the recently finalized (March 2005) Clean Air Interstate Rule (CAIR). Despite these uncertainties, allowance prices stabilized in 2004 and are down appreciably from early 2003 (see Figure 25), which is one indication that the cap and trade market has matured. 

## Banking in 2004 and Flo w Control Next Season Under the NBP , banking provisions allow companies to decrease emissions more than what was required early in the program, and then save unused allowances for futureuse. Banking results in environmental and health benefits earlier than required by the NBP and provides a pool of allowances available to address unexpected events or smooth the transition into deeper emission reductions. 

### Figur e 24: Economically Signif icant T rades

Sour ce: EP A If sources use a large number of banked allowances in one year, the elevated emissions could potentially reduce the environmental effectiveness of the NBP . The NBP’s progressive flow control provisions were designed to discourage extensive use of banked allowances in a particular ozone season. Flow control is triggered when the total number of allowances banked for all sources exceeds 10 percent of the total regional budget for the next year. When this occurs, EP A calculates the flow


### Figur e 25: Vintage Y ear NO x Allo wance Pr ices by Month of Sale

Sour ce: Evolution Markets, LLC and Cantor En vir onmental Br okerage

25control ratio by dividing 10 percent of the total trading budget by the number of banked allowances (a larger bank will result in a smaller flow control ratio). The resulting flow control ratio indicates the percentage of banked allowances that can be deducted from a source’s account in a ratio of one allowance per ton of emissions. The remaining percentage of banked allowances, if used, must be deducted at a rate of two allowances per one ton of emissions.
W ith a large number of additional sources in 2004 and the addition of Compliance Supplement Pool (CSP) allowances to states’ budgets, the level of banked allowances in the NBP increased to nearly 208,000, well beyond the previous year’s total of more than 28,000. These banked allowances represent 40 percent of the total allocations for the 2005 ozone season. Because this ratio exceeds 10 percent, flow control will be triggered in 2005. 

## Continuous Emissions Monitor ing System Results In order for N O x allowances to be accurately tracked and traded, NBP sources must use consistent monitoring procedures to determine their emissions. Accurate and consistent monitoring ensures that all allowances in the NBP have the same value (i.e., a ton of N O x emissions from one NBP source is equal to a ton of N O x emissions from any other source in the program). Analysis of the continuous emissions monitoring data reported by NBP sources in 2004 convincingly demonstrates the high quality of the data (see Figure 26). Industrial sources, many of which have been monitoring under EP A

’s detailed monitoring procedures (40 CF R Part 75) only since 2003, were able to perform at nearly the same level as electric generating units, most of which have been monitoring under Part 75 for about a decade. In 2004, both the electric generating units andindustrial units passed more than 98 percent of the quality assurance tests required of their monitoring systems. These tests included:

• Daily calibration error tests, which use referencegases of known concentrations, or (for flow monitors) reference signals with known values, to test a monitor at a zero po int and an upscale po int.

• Quarterly linearity checks (for gas monitors, only), which are similar to the daily calibration procedurebut performed at three intermediate gas concentrations across the range of the analyzer

.



### Flow Control Will Apply in 2005—How Will It Affect Sources?

• 2005 Regional Budget: 516,245 allowances
• Banked Allowances after 2004: 207,625 allowances
• Flow Control T rigger: 207,625/516,245 > 10 percent, triggering flow control for 2005

• The flow control ratio will be 0.25 (determined by dividing 10 percent of the total trading program budget by the total number of banked allowances, or 51,625/207,625).

• The flow control ratio is applied to banked allowances in each source’ s compliance and overdraft allowance accounts at the time of compliance reconciliation.

– For example, if a source holds 1,000 banked allowances at the end of 2005, it will be able to use 250 of them on a 1-for-1 basis, but will have to use the remaining 750, if necessary , on a 2-for-1 basis for compliance.
• If the source used all of its 1,000 banked allowances for 2005 compliance, the banked allowances could be used to cover only 625 tons of NO x emissions (250 + 750/2).

26• Semiannual or annual relative accuracy test audits which compare data from the monitoring system to concurrent measurements of the stack emissions with an EP A reference test metho d. NBP sources also reported quality-assured emissions data for more than 99 percent of their operating hours in 2004 (see Figure 26). Part 75 requires conservatively high substitute data values to be reported for missing data perio ds, but substitute data were used less than 1 percent of the time in 2004 and therefore had little impact on the cumulative N O x mass emissions reported by the NBP sources. 

## Compliance Options under the NOx Budget T rading Program In a way that best fits their own circumstances, sources can choose from a variety of compliance options to meet the emissions reduction targets of the NBP . These include decreasing generation from certain units (such as units with high N O x emissions), mo difying or optimizing the basic combustion process to control the formation of N O x , using add-on controls, or purchasing additional allowances from other market participants. Many electric generating units installed combustion controls to meet the N O x emission limits of the Acid Rain Program. In addition, some industrial units added combustion controls to meet state N O x emission limits. For bo ilers, furnaces, and heaters, these controls include low N O x burner and overfire air technologies, which

mo dify the combustion process to reduce formation of NO x from nitrogen present in the combustion air andfuel. Advances in combustion control technologies continue to provide cost-effective options to reduce emissions even further for some units. Add-on control technologies, such as selective catalytic reduction (SCR) or selective non-catalytic reduction (SNCR), are frequently applied for N O x control. SNCR and SCR are control technologies that achieve N O x reductions by injecting ammonia, urea, or another N O xreducing chemical into the flue gas within or downstream of the combustion unit to react with N O x , forming nitrogen and water. SCR adds a catalyst to allow this reaction to occur in a lower temperature 

### Figur e 26: 2004 NO x Budget T rading Pr ogram Quality Assurance Performance of Continuous Emissions Monitors, Electr ic Generating and Industr ial Units

Sour ce: EP A
Note: These r esults include appr o ximately 1,300 electr ic generating and 275 industr ial units that r eported under the NBP using CEMS in 2004.



### What Monitoring Options Can Sources Use?
EP

A has developed detailed procedures (40 CFR Part 75) to ensure that sources monitor and report emissions with a high degree of precision, accuracy, reliability, and consistency

. Coal-fired units are required to use continuous emission monitoring systems (CEMS) for NO x and stack gas flow rate (and if needed, CO 2 or O 2 and moisture), to measure and record their NO x mass emissions. Oil and gas-fired units may alternatively use a NO x CEMS in conjunction with a fuel flowmeter to determine NO x mass emissions. For oil and gas-fired units that are either operated infrequently to provide power during periods of peak demand or that have very low NO x emissions, Part 75 provides low-cost alternatives to estimate NO x mass emissions. Figure 26 presents only the results for units that use CEMS.

27range. While SNCR is mainly applicable to bo ilers, furnaces, heaters, and kilns, SCR can be used for a wider range of electric generating and industrial units. Sourcesreport pollution control information, including installation dates, in monitoring plans submitted to EP A.Figure 27 shows the breakdown of how electric generating sources have employed emission controls as of the 2004 ozone season, by both number of units and the percent of total ozone season generation. In the 2004 ozone season, there were about 2,200 electric generating units affected under the NBP. Coal-fired electric generating units with combustion controls (about 400 units) represented 43 percent of total generation during the ozone season. Coal-fired electric generating units with SCR (122 units) constituted about 5 percent of electric generating units, but represented more than 30 percent of the total ozone season generation. In contrast, o iland gas-fired electric generating units (over 1,500 units) constituted nearly 70 percent of all electric generating units but accounted for less than 15 percent of total ozone season generation. Figure 28 shows similar information for industrial units,but based on steam output rather than electric generation. In the 2004 ozone season, there were 340 industrial units affected under the NBP . Most industrialunits either identify combustion controls in their monitoring plans or do not identify any type of add-on controls. There are only a few exceptions where SCR or SNCR is employed. There are no cases where coalfired industrial units employ SCR. Except for turbines that can use a relatively simple form of SCR, the use ofSCR is typically limited to larger coal-fired electric generating units that can achieve significant emission reductions in a highly cost effective way

. In addition to adding controls, decreasing generation from certain units (e.g., those with high NO x emissions)and making operational or fuel changes are other metho ds sources can use to achieve emission reductions. T able 3 shows that the total heat input for all NBP sources increased slightly (less than 2 percent) from 2003 to 

### Figur e 27: Per cent of T otal 2004 Ozone Season Electr ic Generation by Fuel and Contr ol T ype

Sour ce: EP A
* In 2004, only 14 oil/gas units had SNCR, making up less than 1 percent of ozone season generation. 2004. The heat input from coal-fired units decreased a small amount, while the heat input from gas-fired units increased. Although there were small differencesbetween fuel types, the overall heat input change suggests that there was no substantial shift from coal-fired units to lower emitting o il- or gas-fired units in 2004. 

## Coal-f ired Units Account for Nearly All Emission Reductions since 2003
T

able 3 indicates that coal-fired units accounted for nearly all of the 226,000 tons of emission reductions achieved by NBP units from 2003 to 2004. This analysis first examines emission reductions from units that added new controls in 2004 and then focuses on those units that achieved emission reductions with no reported change in controls. By the end of the 2004 ozone season, 122 coal-fired units reported using SCR controls to meet the NBP requirements, an increase of more than 30 units since the end of the 2003 ozone season. Seven units reported

28adding SNCR systems during this perio d, and 17 units reported the installation of new or upgraded combustion controls. Overall, units that installed new controls(since the end of the 2003 ozone season) reduced emissions by about 91,000 tons from 2003 levels. Additional reductions were achieved by units that installed add-oncontrols in the 2003 ozone season or earlier but operated those controls more in the 2004 ozone season. Theseunits (primarily units with SCR controls) reduced emissions by about 28,000 tons in the 2004 ozone season.Coal-fired units with no add-on controls and no reported change in their control status after the 2003 ozone season were nonetheless able to reduce mass emissionsby more than 100,000 tons from 2003 ozone season levels. T o assess how those reductions may have occurred, EP A analyzed these units based on 2003 N O x rates, ordered by highest to lowest emitters. This analysis excludes coal-fired units in OTC states because those units already had to meet trading program budgetrequirements in 2003 and did not reduce emissions significantly from 2003 to 2004. In 2004, units with the highest 2003 N O x emission rates (the top 25 percent)decreased total ozone season heat input by about 15 percent from 2003 levels. The remaining units had only a

mo derate decrease in heat input (generation), approximately 2 percent. Mass emission reductions were also attributable to emission rate reductions. For example, the units with the highest 2003 emission rates (the top25 percent) experienced a median emission rate reduction of about 0.12 lb/mmBtu. The remaining units realized a more mo derate N O x rate reduction (themedian reduction was about 0.05 lb/mmBtu). While discrepancies in the reported information on types of N O x controls installed likely explain rate reductions for some of these units, these types of rate reductions also can occur as a result of operational changes or fine-tuning of the existing combustion controls, which sources do not report to EP A. 

### Figur e 28: Per cent of T otal 2004 Ozone Season Steam Output for Industr ial Units by Fuel and Contr ol T ype

Sour ce: EP A
Note: Industr ial units generally pr o vide generation data as steam output load. Some industr ial units pr o vide electr ical output data because the y pr o vide electr ical ener gy for on-site use
. T hat electr ical load data was con verted to a steam equivalent (1,000 pounds per hour) to allo w consistent compar ison of data.

Heat input is the heat derived from the combustion of fuel in a unit. It is a simple way to track utilization of affected units. The overall heat input levels from affected sources in the NBP states increased slightlybetween 2003 and 2004 without the addition of a significant number of sources. This indicates that, on a systemwide basis, sources in the region were able to maintain their preexisting generation levels while still complying with the NBP

.

29

### T able 3: Compar ison of 2003 and 2004 Ozone Season NO x Mass Emissions, Heat Input, and NO x Emission Rates in the NO x Budget T rading Pr ogram

Units by Fuel T ype Ozone Season NO x Mass Emissions (tons) Ozone Season Heat Input (mmBtu) Ozone Season NO x Emissions Rate

(lb/mmBtu)
2003 2004 2003 2004 2003 2004
Coal 770,000 (94%) 548,000 (93%) 4.7 billion (84%) 4.7 billion (83%) 0.33 0.23
Oil 25,000 (3%) 25,000 (4%) 260 million (5%) 260 million (5%) 0.19 0.19
Gas 24,000 (3%) 20,000 (3%) 590 million (11%) 690 million (12%) 0.08 0.06
T

otal 819,000 593,000 5.57 billion 5.65 billion 0.29 0.21

Sour ce: EP A

Notes:
• T ons r ounded to the near est 1,000 tons. T otals may not equal the sum of the values for each fuel type due to r ounding. The dat a pr esented her e ar e for the ozone season May 1-September 30.

• The A verage emission rate is based on dividing total r eported ozone season NOx mass emissions for each fuel category by the total ozone season heat input r eported for that category
. The average emission rate expr essed for the “T otal” is the heat input weighted average for the thr ee fuel categor ies.

30Despite improvements in ozone air quality in many areas of the country , ozone continues to be a pervasive air pollution problem. More than 100 million people inthe eastern United States are still living in nonattainment areas that do not meet the 8-hour ozone standard. Continued reductions anticipated under the NO x SIP Call will help reduce emissions of NO x and improve air quality . Recent national mobile source regulations will help reduce ozone by reducing NO x and V O Cs from new passenger vehicles, heavy-duty diesel engines, and other mobile sources. In addition, EP A

’s Clean Air Interstate Rule (CAIR)will help further reduce ozone in the East. This landmark rule, issued March 10, 2005, will permanently cap power industry emissions of sulfur dioxide (SO 2 ) and NO x in the eastern United States, achieving large reductions of these pollutants. CAIR will build on the ozone season emission reductions from the NO x SIP Call. In 2015, CAIR, the NO x SIP Call, and other programs in the CAIR region will reduce power industry ozone season NO x emissions by about 50 percent and 

# Chapter 5: Futur e NO x Reductions and Ozone Impr o vements

How Does the Clean Air Interstate Rule (CAIR) Affect NOx Budget T rading Program States?
The NO x SIP Call requirements will remain in place, but in 2009, EP A will stop administering the existing regional ozone season NO x trading programs. States can meet their NO x SIP Call obligations using the CAIR’ s ozone season NO x trading program. CAIR allows states to include all of their NO x SIP Call trading sources in the CAIR ozone season trading program. If a state includes industrial units, the trading budget for those units remains the same as the NOx SIP Call. The 2009 CAIR ozone season NO x electric generating unit budgets are at least as stringent as the NO x SIP Call budgets, and in some states are tighter

. In 2015, the ozone season emission cap will be further reduced. In addition, because CAIR allows sources to use pre-2009 NO x SIP Call allowances for compliance on a 1:1 basis with the CAIR ozone season NO x program (i.e., the allowances can be banked and carried into the CAIR), NO x Budget T rading Program (NBP) sources have an incentive to begin reducing their emissions now

. Also, as with the NO x SIP Call, the CAIR annual NO x program includes a compliance supplement pool to provide incentives for sources to reduce non-ozone season NO x emissions prior to CAIR. For more information, visit <www .epa.gov/cair>.

31

### Figure 29: States Covered by the Clean Air Interstate Rule (CAIR)

particles only ozone only ozone and particles

Source: EP A
Note: EP A pr oposed in Mar ch 2005 to add Delawar e and New Jer se y to the states in CAIR co ver ed for f ine particles.

annual NO x emissions by about 60 percent from 2003 levels. In addition by 2015, CAIR and other existing airprograms will reduce the number of 8-hour ozone nonattainment areas, and will bring remaining areas closer to attainment. In 2015, EPA predicts that with CAIR and existing federal and state programs, only six ozone nonattainment areas will remain in the East: Chicago; Houston; Philadelphia, New Y ork City; Baltimore and Washington, D.C. States are working to identify and implement local controls to move these remaining six areas toward attainment. CAIR is similar to the NO x SIP Call in that it requiresstates to submit SIPs and meet a budget to reduce emissions. CAIR reduces NO x through two budgets: ozone season NO x budgets in 25 states and W ashington, D.C., and annual budgets to reduce fine particle pollution (PM 2.5) in 23 states and W ashington, D.C. In March 2005, EP A proposed to add Delaware and New Jersey to the states in CAIR covered for fine particles. Many states are affected by CAIR for both ozone season NO x and annual NO x and SO 2 (see Figure 29). Like the NO x SIP Call, CAIR establishes EP A-administered, interstate cap and trade programs that states can choose to use to obtain the required emission reductions. EP A anticipates that most, if not all, affected states will jo in these trading programs.

32

### Ozone and Particle Pollution in the Future
The Clean Air Interstate Rule (CAIR), T ogether With Other Clean Air Programs, Will Bring Cleaner Air to Areas in the East

. On March 10, 2005, EP A issued CAIR. This rule will achieve the greatest air quality improvement, and the deepest cut in emissions of SO 2 and NO x in more than a decade. Key compliance dates are 2009 (Phase I cap on NO x ), 2010 (Phase I cap on SO 2) and 2015 (Phase II cap on NO x and SO 2).

Ozone and Fine Par ticle Nonattainment Projected Nonattainment Areas in 2010 Projected Nonattainment Areas in 2015 Areas (April 2005) after Reductions from CAIR and after Reductions from CAIR and Existing Clean Air Act Programs Existing Clean Air Act Programs

Nonattainment areas for both 8-hour ozone and fine par ticle pollution Nonattainment areas for fine par ticle pollution only Nonattainment areas for 8-hour ozone only

Sour ce: EP A
Note: Pr ojections concerning futur e levels of air pollution in specif ic geographic locations wer e estimated using the best scien tif ic models available
. The y ar e estimations, ho wever . Actual r esults may vary signif icantly if any of the factor s that influence air quality diff er fr om the assu med values used in the pr ojections sho wn her e .

33

# Online Resour ces

General Information:
• O ff i c e o f A i r a n d R a d i at i o n : www .epa.gov/oar

– O ff i c e o f A i r Q u a l i ty P l a n n i n g a n d S t a n d a r d s : www .epa.gov/oar/oaqps

– O ff i c e o f At m o s p h e r i c P r o g r a m s : www .epa.gov/air/oap.html • N at i o n a l Ac a d e m i e s : www4.nationalacademies.org/nas/nashome.nsf • M o b i l e S o u r c e s : www .epa.gov/otaq • C a p a n d T r a d e a n d R e l at e d P r o g r a m s : www .epa.gov/airmarkt/index.html 

### NO x Contr ol Pr ograms:
• Ac i d R a i n P r o g r a m : www .epa.gov/airmarkets/arp/index.html • O z o n e T r a n s p o rt C o m m i s s i o n ( O T C) N O x B u d g e t P r o g r a m : www .epa.gov/airmarkets/otc/index.html • N O x B u d g e t T r a d i n g P r o g r a m : www .epa.gov/airmarkets/fednox/index.html • C l e a n A i r I n t e r s t at e R u l e ( CA I R) : www .epa.gov/cair/index.html 

### Ozone Information:
• F o r m at i o n o f O z o n e : www .epa.gov/air/urbanair/ozone/what.html • H e a l t h a n d E c o l o g i c a l E ff e c t s : www .epa.gov/air/urbanair/ozone/hlth.html • O z o n e D e p l e t i o n : www .epa.gov/ozone • 8

- h o u r a n d 1

- h o u r O z o n e T r e n d s a n d F a c t b o o k : www .epa.gov/airtrends 

### Emissions Data and Monitor ing Information:
• N at i o n a l E m i s s i o n s I n v e n t o ry ( N E I ) : www .epa.gov/ttn/chief/net/ • E m i s s i o n s D at a f o r t h e P o w e r I n d u s t ry : http://cfpub.epa.gov/gdm • E m i s s i o n s D e v e l o p m e n t : www .epa.gov/ttn/chief/trends/procedures/neiproc_99.pdf • N O x a n d V O C L i m i t at i o n : www .cgenv .com/Narsto/american.chem.council.html 

### Ozone Monitor ing Netw orks and Data:
• C l e a n A i r S t at u s a n d T r e n d s N e tw o r k ( CAS T N E T ) : www .epa.gov/castnet • A i r Q u a l i ty S y s t e m ( A Q S) : www .epa.gov/ttn/airs/airsaqs 

### Other Emissions and Air Quality Resour ces:
• G e n e r a l I n f o r m at i o n o n E P A A i r Q u a l i ty M o n i t o r i n g N e tw o r ks : www .epa.gov/ttn/amtic • C l e a n A i r M a p p i n g a n d A n a l y s i s P r o g r a m ( C

- M A P) : www .epa.gov/airmarkets/cmap/index.html • T h e E m i s s i o n s a n d G e n e r at i o n R e s o u r c e I n t e g r at e d D at a b a s e (e G R I D ) : www .epa.gov/cleanenergy/egrid/index.html • A I R N o w : www .epa.gov/airnow

34United St ates Environment al Protection Agency Of

fice of Air and Radiation Of

fice of Air Quality Planning and Standards Of

fice of Atmospheric Programs (6204J) 1200 Pennsylvania A ve, NW Washington, DC 20460 www .ep a.gov/airtrends www .ep a.gov/airmarkets
EP A454-K-05-001 August 2005

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