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SECTION 1 INTRODUCTION AND BACKGROUND

1.1 Summary and Purpose of Document

The Massachusetts Department of Environmental Protection (MassDEP) is submitting this State 

Implementation Plan (SIP) to Demonstrate Attainment of the National Ambient Air Quality 

Standard for Ozone to the U.S. Environmental Protection Agency (EPA) to demonstrate that the 

Eastern Massachusetts nonattainment area (EMA) and the Western Massachusetts nonattainment 

area (WMA)1 will attain the National Ambient Air Quality Standard (NAAQS) for ozone by the 

end of the 2009 ozone season. MassDEP relies on modeling to demonstrate that both areas will 

attain the standard by this date, supplemented by additional evidence that further supports this 

conclusion. MassDEP also demonstrates that by 2008, EMA and WMA will achieve Reasonable 

Further Progress (RFP) towards attainment of the ozone standard. 

This submission includes the 2002 Massachusetts Base Year Emissions Inventory, which 

estimates Massachusetts 2002 in-state emissions of pollutants that contribute to ozone formation. 

The inventory serves as the base year for estimating emissions in 2008 and 2009, as required for 

the RFP and attainment demonstrations. MassDEP has also included 2012 emissions projections 

to demonstrate that emissions from Massachusetts sources will continue to decrease in 

subsequent years. 

To meet RFP and attainment requirements, MassDEP has adopted, or is committing to adopt, 

new control measures to reduce the emissions of volatile organic compounds (VOCs) and 

nitrogen oxides (NOx) that contribute to the formation of ozone. New measures include NOx 

controls on electric generating units and other large boilers under the Massachusetts Clean Air 

Interstate Rule (Mass CAIR) and tighter emission controls for certain sources of VOCs. Existing 

MassDEP and numerous federal measures will also result in continued reductions of these 

pollutants. 

This submittal addresses ozone standard requirements for the adoption of Reasonably Available 

Control Technology (RACT) for sources subject to RACT requirements. MassDEP is adopting 

regulations to tighten its existing RACT standards for certain source sectors. For the Municipal 

Waste Combustor RACT source sector, MassDEP commits to do additional analysis. For other 

RACT sectors, it concludes that existing RACT meets the ozone standard requirements. 

In addition to RACT, MassDEP has reviewed other potential control measures based on EPA’s 

criteria for adoption of Reasonably Available Control Measures (RACM). MassDEP concludes 

that there are no other RACM that could be adopted in Massachusetts that would result in 

attainment in either EMA or WMA earlier than 2009. 

The submittal demonstrates that EMA and WMA have contingency measures in place that will 

result in additional reductions in ozone precursor emissions if, despite the RFP and attainment 

demonstrations that are made in this SIP, either area fails to meet its RFP or attainment 

 

1 The counties in EMA are: Barnstable, Bristol, Dukes, Essex, Middlesex, Nantucket, Worcester, Suffolk, 

Plymouth and Norfolk. The counties in WMA are: Hampden, Hampshire, Berkshire and Franklin. For a 

map of the two areas see Section 5, Attainment Demonstration, page 2, Figure AD1. 
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requirements. The additional reductions will be achieved without further state or federal action, 

as EPA requires. 

This submittal includes on-road mobile source Transportation Conformity Budgets for EMA and 

WMA for the 2008 RFP year and for the 2009 attainment demonstration year. 

1.2 Ozone Formation and Health Impacts 

Ground level (tropospheric) ozone is formed when NOx, VOCs and to a lesser extent, carbon 

monoxide (CO), interact in the presence of sunlight. NOx and VOCs, the primary ozone 

precursors, are emitted into the air from many human activities, including power plants, 

industrial boilers, automobiles, and consumer and industrial products. VOCs are also emitted 

from vegetation. Ozone and ozone precursors are often transported into Massachusetts from 

pollution sources in other states. Variability in weather patterns contributes to yearly differences 

in the magnitude and frequency of ozone concentrations. 

Ozone has adverse effects on human health. It can irritate the respiratory system, causing 

wheezing and coughing, and irritate the eyes and nose. Ozone can affect lung function, reducing 

the amount of air that can be inhaled and limiting the maximum rate of respiration, even in 

healthy individuals. Exposure to ozone can also increase the frequency and severity of asthma 

attacks, resulting in more emergency room visits, medication treatments and lost school or 

workdays. Other possible short-term effects from exposure to high levels of ozone include 

aggravation of symptoms of emphysema, bronchitis and chronic obstructive pulmonary disease 

and increased susceptibility to respiratory infections. Health studies raise the concern that 

repeated short-term exposure to ozone might lead to permanent damage in lung function, 

especially in children. Recent analysis of health research in the U.S. and Europe has also found a 

strong linkage between increases in ozone and risk of premature death. Recent studies also 

indicate that ozone may contribute to cardiac morbidity. These relationships indicate that the 

costs and health consequences of not reducing ozone pollution are far higher than previously 

realized. 

1.3 1-Hour Ozone NAAQS

In 1979, EPA adopted a NAAQS for ozone set at 0.125 parts per million (ppm) averaged over a 

1-hour period (the 1-hour ozone standard). Nonattainment areas were required to adopt programs 

to attain the standard by 1987. Massachusetts violated the 1-hour ozone standard and, as 

required by the Federal Clean Air Act (CAA) and EPA regulations, adopted regulations and 

programs to reduce emissions of ozone-precursors. Despite significant improvement in measured 

ozone levels, Massachusetts (along with many other areas) continued to violate the 1-hour ozone 

standard throughout the 1980s. 

The 1990 CAA Amendments required EPA to classify ozone nonattainment areas as marginal, 

moderate, serious, severe or extreme and imposed new control requirements. EPA classified 

EMA and WMA as “serious” nonattainment areas. (56 FR 56694, November 6, 1991) 

Massachusetts adopted additional measures to reduce emissions of ozone precursors during the 
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1990s and submitted numerous SIP revisions to EPA documenting its progress towards 

attainment. In 1998, MassDEP submitted to EPA a SIP demonstrating that WMA would attain 

the 1-hour ozone standard by the end of 2003. In 2002, it submitted a SIP demonstrating that 

EMA would attain the standard by 2007. 

As of June 15, 2005, EPA revoked the 1-hour standard as part of its implementation of the new 

8-hour ozone standard. Therefore, areas are no longer required to monitor 1-hour ozone levels. 

1.4 8-Hour Ozone NAAQS

In 1997, based on studies that indicated that longer-term exposures to lower ozone 

concentrations cause adverse health effects, EPA issued a new standard set at 0.08 ppm averaged 

over eight hours (the 8-hour ozone standard).2 In 2001, following legal challenges to the new 

standard, the U.S. Supreme Court upheld the standard. In 2004, EPA designated every county in 

the U.S. as attainment, non-attainment or unclassifiable and classified 8-hour ozone standard 

nonattainment areas according to the severity of their ozone violations. EMA and WMA are 

classified as moderate non-attainment areas under the 8-hour standard, based on monitored 

ozone readings for the 2001 – 2003 period. (69 FR 23858, April 15, 2004) 

EPA promulgated implementation rules for the 8-hour ozone Standard in two phases; Phase 1 

was promulgated on April 30, 2004 (the Phase 1 Rule)3and Phase 2 was promulgated on 

November 29, 2005 (the Phase 2 Rule).4 The Phase 2 Rule requires that areas submit to EPA by

June 15, 2007, a SIP demonstrating attainment by the end of the 2009 ozone season (the year 

prior to the June 15, 2010 attainment deadline) and demonstrating emission reductions by 2008 

sufficient to establish that they are making Reasonable Further Progress (RFP) towards 

attainment. The Phase 2 rule also requires that areas submit a SIP addressing 8-hour ozone 

RACT requirements. 

The SIP for moderate nonattainment areas must include the elements listed below. This SIP 

submittal addresses all of the required elements in the Sections noted.

 Reasonable Further Progress (RFP) demonstration of a 15% reduction in in-state VOC 

and/or NOx emissions within 6 years after the baseline year of 2002 (e.g., by 2008). 

(Section 4)

 Attainment demonstration that uses modeling and other technical analyses to demonstrate 

that attainment of the 8-hour NAAQS is projected by the end of the 2009 ozone season. 

(Section 5)

 Reasonably Available Control Technology (RACT) for RACT source sectors and for 

major sources of VOC and NOx . (Section 6)

 Reasonably available control measures (RACM) for all sources. (Section 7)

 

2

 The 8-hour ozone standard is met when the 3-year average of the 4th-highest daily maximum 8-hour 

average does not exceed 0.08 parts per million (ppm) at any one monitor (effectively, 0.084, given accepted 

rounding conventions).

3 Final Rule to Implement the 8-Hour Ozone National Ambient Air Quality Standard - Phase 1, 69 FR 

23951 April 30, 2004. 

4 Final Rule to Implement the 8-Hour Ozone National Ambient Air Quality Standard – Phase 2, 70 FR 

71612, November 29, 2005.
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 Contingency measures to be implemented upon failure to meet RFP or attainment 

milestones. (Section 8) 

 Transportation conformity budgets for RFP milestone and attainment years. (Section 9)

 Inspection and Maintenance (I/M) program for light-duty motor vehicles. (Adopted in 

Massachusetts under the 1-hour ozone standard; see Appendix 3A)

 Stage II vapor recovery for gas stations. (Adopted in Massachusetts under the 1-hour 

ozone standard; see Appendix 3A)

 New Source Review (NSR) program for major sources, including offsets for VOC and 

NOx at a 1.15 to 1 ratio and a permit program for new or modified sources. (Adopted in 

Massachusetts under the 1-hour ozone standard; see Appendix 3A)

In December 2006, the U.S. Court of Appeals for the D.C. Circuit issued a ruling vacating EPA’s 

Phase 1 rule, holding that parts of the rule violated provisions of the CAA. On June 8, 2007, the 

Court clarified its decision stating that it was vacating only parts of the rule, while leaving other 

sections in effect. It urged EPA to promptly promulgate a revised rule. It is unclear how the 

future resolution of this litigation may impact 8-hour ozone SIP requirements. This SIP is based 

on the requirements of the published EPA rule that remain in effect and a memo from EPA 

concerning the implications of the June 15, 2007 opinion of the court.5 Revisions to this SIP may

be required upon resolution of the litigation and/or promulgation by EPA of a revised 

implementation rule. 

1.5 Massachusetts 8-Hour Ozone NAAQS Compliance

In Section 5, Attainment Demonstration, MassDEP has demonstrated through modeling that 

EMA and WMA will attain the 8-hour ozone standard in 2009. The modeling for EMA and 

WMA shows that ozone concentrations will be 0.084 parts per million, or lower, at all monitors 

in 2009 (see Section 5, Table AD 9). MassDEP has provided evidence, in addition to the 

modeling, that further supports its expectation that Massachusetts will attain the standard 

statewide by 2009. 

However, in addition to demonstrating attainment in the attainment year through modeling, 

monitored ozone concentrations in EMA and WMA must actually meet the standard in the 

attainment year. As noted in footnote 2, ozone design values are based on a 3-year average of the 

4

th highest monitored reading. In 2007, Massachusetts (and other Northeast States) had a number 

of days when monitored ozone concentrations exceeded the concentrations recorded in recent 

years. As a consequence, for the 2005–2007 period, two monitors in WMA have 3-year averages 

exceeding the 8-hour standard: Chicopee (0.092 ppm) and Ware (0.087 ppm). In EMA, one 

monitor (Blue Hill - 0.086 ppm) exceeded the standard during the 2005-2007 period. 

When EPA makes its determination whether to approve this SIP, it will consider whether EMA 

and WMA are monitoring ozone concentrations that are consistent with the modeled attainment 

demonstration that forms the basis of Section 5, Attainment Demonstration. EPA will consider 

 

5 U.S. EPA, Memorandum from Robert J. Meyers, Acting Assistant Administrator, June 15, 2007, 

Decision of the U.S. Court of Appeals for the District of Columbia Circuit on our Petition for Rehearing 

of the Phase 1 Rule to Implement the 8-Hour Ozone NAAQS. 
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the most recent 3-years of monitored data that is available, including data for 2007, 2008 and 

possibly 2009, depending on when EPA proposes action concerning this submission. 

MassDEP is confident that the monitors that are only slightly over the standard for the 2005-

2007 period will meet the standard by the 2009 attainment year because of the substantial 

emission reductions that will take place prior to that date. However, the monitor in Chicopee in 

WMA had 4th- high readings of 0.90 ppm in 2006 and 0.98 ppm in 2007. Therefore, there is a 

significant risk that the Chicopee monitor will not monitor attainment in the 2006 – 2008 and 

2007-2009 periods.6 

MassDEP expects that if the Chicopee monitor is not in attainment for the 3-year period on 

which EPA bases its determination, WMA will meet the criteria to be eligible for a 1-year 

extension of the attainment date in 2009.7 Massachusetts, and upwind states, will continue to 

achieve ozone precursor emission reductions after 20098and additional reductions will be 

realized by the 2010 ozone season. Therefore, if WMA does not attain the standard in 2009, the 

likelihood that it will reach attainment in 2010 is high. 

High ozone concentrations in WMA are generally attributable to ozone transport from 

Connecticut and other states directly upwind of the WMA monitors. Ozone transport is 

especially problematic on days when high electricity demand can dramatically increase 

emissions for electric generation (High Electric Demand Days – HEDD). HEDD emissions often 

occur during the meteorological conditions most conducive to producing the highest levels of 

ozone.9

Mindful of the HEDD problem, the states of Connecticut, New York and New Jersey, 

Pennsylvania, Delaware and Maryland entered into an Ozone Transport Commission 

Memorandum of Understanding to address this problem. These states have committed to a 

variety of energy efficiency and other strategies that will reduce HEDD emissions. 

Massachusetts did not enter into that MOU, but MassDEP continues to review the potential for 

HEDD strategies, including energy efficiency and demand response on peak demand days, for 

 

6

 This 4th-highest reading (.098 ppm), which occurred on August 30, was highly unusual for so late in the 

season. As discussed in Section 5, Attainment Demonstration, Subsection 5.19.5, this high concentration 

may be attributable to two factors: an unusual weather pattern and the presence of smoke from distant 

forest fires. 

7 Under EPA’s Phase 1 ozone implementation rule, an area with a 2009 attainment year is eligible for a 

one-year extension of its attainment deadline if, in 2009, its 4th highest ozone reading is 0.084 ppm or 

less. An area that has received the first of the 1-year extensions under the 8-hour standard would be 

eligible for a second extension if the area's 4th highest daily 8-hour value, averaged over both the original 

attainment year and the first extension year, is 0.084 ppm or less. The unusual nature of the high 

concentrations that occurred in WMA in 2007 supports MassDEP’s expectation that the 4th highest 

reading in WMA in 2009 is likely to be less than 0.084 ppm and that WMA will be eligible for an 

extension of its attainment year in 2009. 

8 Modeling conducted for 2012 projects MA ozone concentrations at levels considerably below the 

projected 2009 values. See Section 5.19.4, 2012 Future Year Simulation.

9

For WMA, the most favorable meteorological conditions for ozone production include high 

temperatures on sunny summer days, with lower level transport winds from the southwest and upper level 

transport winds from the west, regions that produce significant emissions from electric generating units
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Massachusetts sources. Given the risk that WMA may fail to attain the standard by 2009, 

MassDEP is participating as an observer in the Connecticut process to review HEDD strategies 

that will reduce emissions that impact WMA on HEDDs. 

1.6 Public Review Process

A proposed version of this SIP was made available for public review and comment more than 30 

days prior to the public hearings that were held in Boston and Springfield on January 18, 2008. 

Comments on the proposed SIP were submitted to MassDEP from U.S. EPA and other interested 

parties. The commenters, a summary of the comments received, and MassDEP’s responses 

thereto, are in the Response To Comments that is being submitted to EPA with the final Ozone 

SIP. EPA will undertake a review of this final Ozone SIP and decide whether to approve it. EPA 

will provide notice and opportunity for public review of any action it proposes to take in this 

regard.