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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 Quali ty 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 b y this date, supplemented b y additional evidence that further supports this conclusion. MassDEP also demonstrates that b y 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 pollutant s that contribute to ozone formation. The inventory

serves as the base ye ar 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 y ears. 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 nitr ogen 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 sour ces 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 Reasonabl y 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 anal ys is. For other RACT sectors, it co ncludes 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 Reasonabl y Available Control Measures (RACM). MassDEP concludes that ther e 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 SI P, 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.Final - Section 1 - Page 2 of 6

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) ozon e 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 man y human activities, including power plants, industrial boilers, auto mobiles, 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 y earl y differen ces in the magnitude and frequency of ozone concentrations. Ozone has adverse effects on human health. It can irritate the respiratory s ystem, causing wheezing and coughing, and irritate the ey es and nose. Ozone can affect lung function, reducing the amo unt 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 severit y of asthma attacks, resulting in more emergency room visits, medication treatments and l ost school or workday s. Other possible short - term effects from exposure to high levels of ozone include aggravation of s ymptoms of emphy sema, bronchitis and chronic obstructive pulmonary disease and increased susceptibility to respiratory

infections. Heal th studies raise the concern that repeated short - term exposure to ozone might lead to permanent damage in lung function, especiall y in children. Recent anal ys is 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 b y 1987. Massachusetts violated the 1 - hour ozone standard and, as required b y 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. T he 1990 CAA Amendments required EPA to classify ozone nonattainment areas as marginal, moderate, serious, severe or extreme and imposed new control requi rements. 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 theFinal - Section 1 - Page 3 of 6

1990s and submitted numerous SI P revisions to EPA documenti ng its progress towards attainment. In 1998, MassDEP submitted to EPA a SI P 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 b y 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 u pheld the standard. In 2004, EPA designated every count y in the U.S. as attainment, non - attainment or unclassifiable and classified 8 - hour ozone standard nonattainment areas according to the severit y 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 promulgat ed on April 30, 2004 (the Phase 1 Rule) 3 and 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 SI P demonstrating attainment b y the end of the 2009 ozone season (the ye ar 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 addres sing 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 1 5% reduction in in - state VOC and/or NOx emissions within 6 y ears after the baseline y ear of 2002 (e.g., by 2008). (Section 4)  Attainment demonstration that uses modeling and other technical anal ys es to demonstrate that attainment of the 8 - hour NAAQS is pr ojected by the end of the 2009 ozone season. (Section 5)  Reasonabl y Available Control Technology (RACT) for RACT source sectors and for major sources of VOC and NOx . (Section 6)  Reasonabl y available control measures (RACM) for all sources. (Section 7) 2 The 8 -hour ozone standard is met when the 3 - year av erage of the 4 th

- 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 Standar d - 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.Final - Section 1 - Page 4 of 6

 Contingency

measures to be implemented upon failure to meet RFP or attainment milestones. (Section 8)  Transportation conformity budgets for RFP milestone and attainment ye ars. (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 va cating 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 onl y parts of the rule, while leaving other sections in effect. It urged EPA to prompt ly promulgate a revised rule. It is unclear how the future resolution of this litigation may impact 8 - hour ozone SIP requirements. This SI P is based on the requirements of the published EPA rule that remain in effect and a memo from EPA concerning the impl ications of the June 15, 2007 opinion of the court. 5 Revisions to this SI P may be required upon resolution of the litigation and/or promulgation b y EPA of a revised implementation rule. **1.5 Massachusetts 8**  **- Hour Ozone NAAQS Compliance**  In Section 5, Atta inment 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 b y 2009. However, in addition to demonstrating attainment in the attainment y ear through modeling, monitored ozone concentrations in EMA and WMA must actually meet the standard in the attainment y ear. As noted in footnote 2, ozone design values are based on a 3 - year average of the 4 th highest monitored reading. In 2007, Massa chusetts (and other Northeast States) had a number of day s when monitored ozone concentrations exceeded the concentrations recorded in recent ye ars. As a consequence, for the 2005

–2007 period, two monitors in WMA have 3 - ye ar averages exceeding the 8 - hour s tandard: 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 SI P, it will consider whether EMA and WMA are mon itoring 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, 200 7, 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.Final - Section 1 - Page 5 of 6

the most recent 3 - ye ars 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 slightl y over the standard for the 2005 - 2007 period will meet the standard b y the 2009 attainment y ear becau se of the substantial emission reductions that will take place prior to that date. However, the monitor in Chicopee in WMA had 4 th

- high readings of 0.90 ppm in 2006 and 0.98 ppm in 2007. Therefore, there is a significant risk that the Chicopee monitor wil l 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 - ye ar period on which EPA bases its determination, WMA will meet the criteria to be eligible for a 1 - ye ar exte nsion of the attainment date in 2009. 7 Massachusetts, and upwind states, will continue to achieve ozone precursor emission reductions after 2009 8 and additional reductions will be realized by

the 2010 ozone season. Therefore, if WMA does not attain the st andard 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 directl y upwind of the WMA monitors. Ozone transport is especi all y problematic on days when high electricity demand can dramatically increase emissions for electric generation (High Electric Demand Day s – HEDD). HEDD emissions often occur during the meteorological conditions most conducive to producing the highest le vels 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 committe d to a variet y 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 day s, for 6 This 4 th

- highest reading (.098 ppm), which occurred on August 30, was highly unusual f or so late in the season. As discussed in Section 5, Attainment Demonstration , Subsection 5.19.5, this high concentration ma y be attributable to two factors: an unusual weather pattern and the presence of smoke from distant forest fires. 7 Under EPA’s Ph ase 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 4 th highest ozone reading is 0.084 ppm or less. An area that has received the first of the 1 - year extensio ns 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 4 th 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 201 2 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 summ er 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 unitsFinal - Section 1 - Page 6 of 6

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 SI P was made available for public review and comment more than 30 day s prior to the public hearings that were held in Boston and Springfield on January 18, 2008. Comments on the proposed SI P 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 re view of this final Ozone SIP and decide whether to approve it. EPA will provide notice and opportunity for public review of an y action it proposes to take in this regard.