# MDE MARYLAND DEPARTMENT OF THE ENVIRONMENT

1800 Washington Boulevard. Baltimore MD 21230
410-537-3000 • 1-800-633-6101. www.mde.state.md.us

Martin O'Malley

Governor Robert M

. Summers, Ph

. D. Secretary

Anthony G

. Brown

Lieutenant Governor

. '
March 7,2012 ;.

Mr. Shawn M. Garvin Regional Administrator
USEP A Region III (3RAOO)
1650 Arch Street Philadelphia PA 19103-2029

Dear Mr. Garvin:

The purpose of this letter is to provide supporting documentation for Governor O'Malley's designation
recommendations for Maryland. The Department is eager to work with you to achieve a final decision
that we both find acceptable

. Our primary concern is that the final EP A decision must address transport
in a manner that provides Maryland with a reasonable chance of attaining the new standard by 2015 or 2018. EPA ' s preliminary response to Governor O'Malley's March 10, 2009 letter on air quality designations indicates an intention to continue designating small nonattainment areas based almost exclusively on county delineations or Metropolitan Statistical Areas

, not even Combined Statistical
Areas (CSAs). The Department believes this additional documentation and analysis may have a bearing on your final decision.

Governor O'Malley's December 1

, 2011 letter provided updated recommendations on air quality designations for Maryland and included a more urgent request for EP A to consider establishing a large
multi-state nonattainment area to better address the significant impact that transported air pollution has

on Maryland's ability to attain the National Ambient Air Quality Standard (NAAQS).1 EP A's

response letter of December 9,2012 vaguely suggests that other Clean Air Act (CAA) provisions
would provide better relief from long-range transport. In justifying its position, EP A suggests that Maryland ' s recommendation for a large multi-state nonattainment area does not comport with a plain reading of the CAA § 107(d), authorizing nonattainment designations for "nearby" areas which
contribute to a nonattainment area. To the contrary, today's science shows that an elevated reservoir of

ozone forms daily and is trapped at about 2

, 000 feet above the Earth's surface by a nocturnal inversion.
This elevated reservoir adds different background levels of ozone over a large geographic area. Maryland's 20 year ozone research program clearly shows through measured (not modeled) monitoring data, that ozone is being transported into Maryland from upwind states at levels often
above the 75 ppb ozone standard. EPA's decision on the large nonattainment area seems tied to its

1 Maryland currently has areas that are still not attaining the 0.08 ppm ozone standard. According to the Cross State Air
Pollution Rule, this nonattainment is due in significant part to the interstate transport of ozone

.

~ Recycled Paper www.mde

. state

. md.us TTY Users 1-800-735-2258

Via Maryland Relay ServiceMr. Shawn M. Garvin

Page 2

assertion that ' an upwind state, whose daily emissions are transported overnight and cause an ozone exceedance in Maryland the following morning, is not "nearby" within the context of § 107.

Despite the objections to the large nonattainment area EPA raises in its letter, EPA does not dispute
that Maryland is significantly impacted by transport and that these states do in fact significantly
contribute to Maryland ' s nonattainment problem. The largenonattainment area recommended by
Governor O'Malley would be a fair and equitable way to clean the air while minimizing cost and maximizing economic recovery. Without a Ia t ge multi

- state nonattainment area, upwind areas are not
incenti v ized to help achieve attainment in a · downwind air as expeditiously as po

- ssible. To the
contrary

, they are incentivized to maintain current disparities in pollution controls, which provide them

a competitive advantage through lowered industrial costs to upwind businesses and residents.

Absent the large multi

- state nonattainment area to force a compr e hensive SIP addressing
nonattainment at each monitor in the area , subjecting everyone to the same potential sanctions
for failure to attain in the time frames mandated by the CAA, it seems clear that Maryland will not be
able to meet the ozone NAAQS by the mandated deadlines. In the alternative

, the Department finds
substantial evidence that

, at a minimum

, the Baltimore-Washington consolidated statistical area should
be designated as one nonattainment area rather than several, as EP A has recommended. EP A's
recommendation to exclude Washington D.C. from the Baltimore nonattainment area is inconsistent
with EPA's current interpretation of ' nearby' contributing areas, and would serve to only further
isolate the Baltimore nonattainment area and reduce its ability to timely attain the ozone NAAQS. The designation of a single nonattainment area combining the Baltimore and Washington regions is clearly supported by EPA ' s 5 factor technical analysis that shows monitors in the Baltimore region consistently monitoring the same ozone levels as design v alue monitors in the Virginia area.

We want clean air for the citizens of Maryland

. After a 30 year struggle

, we feel we have empirical
data

, sound scientific evidence and a clear path to that goal

. Success

, however

, will require EP A's help. We are anxious to work in partnership with EP A to attain the public health protection we all are working to achieve. We have major concerns that EPA's current policy on nonattainment boundaries
will not allow Maryland to meet CAA public health protection deadlines. Equally important are our

concerns over how EPA's decision may have a negative impact on Maryland's economic recovery efforts

. As always

, we are willing to work with EP A to find a collaborative solution to our problem.

Sincerel y, 

# /jV/Ym

Robert M. Summers, Ph.D. Secretary

Enclosure

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Via Maryland Rela y Se r v i c eMARYLAND DEPARTMENT OF THE ENVIRONMENT 120 DAY LETTER RESPONSE

The State of Maryland through the Department of the Environment submits this response to EPA’s proposed ozone nonattainment designat ions for the 75 ppb ozone standard for Maryland, which were transmitted in Regional Ad ministrator Garvin’s December 9, 2011 letter and which EPA published notice on December 20, 2011 in 75 Fed. Reg. 78872. The Department supports the implementation of the 75 ppb ozone standard as quickly as possible but believes that the designation process s hould still afford Maryland an opportunity to negotiate regarding designations as intended und er § 107 of the Clean Air Act (CAA). EPA’s official proposal seems to indicate the designations are a fait accompli and further communications would not lead to any changes whatsoever. We hope that this is not the case.

The Department continues to pursue the reco mmendation from Governor O’Malley’s March 10, 2009 letter for a large multi-state nonattainme nt area as the best option for Maryland designations. This document will provide further details explaining why a proper 5-factor (or 9 factor) analysis should result in such a designation. If EPA c ontinues to designate smaller nonattainment areas, the Department does not und erstand why, at a minimum, EPA has failed to propose for designation the Baltimore Washi ngton Combined Statisti cal Area (CSA) as a single nonattainment area using its nine (or five ) factor analysis. The Department would like to discuss this as a second option. Furt her supporting documentation follows recommending that option also.

Preferred Option

The Department believes that EPA should de signate areas as init ially recommended by Governor O’Malley by letter dated March 10, 2009 and more recently by letter dated December 1, 2011. Expressly, EPA should design ate a large multi-state ozone nonattainment area consisting of the following 16 states and th e District of Columbia: Maryland, Delaware, New Jersey, New York, Pennsylvania, Virgin ia, West Virginia, Ohio, North Carolina, Tennessee, Missouri, Illinois, Indiana, Kentucky, Michigan and Wisconsin. These are the states that EPA has identified as significantly contributing to Maryland ’s ozone problem. A 5- factor analysis supporting such a designation is found in Appendix A.

EPA has raised three principal ob jections to the designation of a large nonattainment area: 1) it is “not in keeping with a pl ain reading of CAA § 107(d)” as it relates to contributions from “nearby areas; 2) the CAA offers other solu tions to the transport problem and 3) large nonattainment areas are unworkable. Notably, these objections do not dispute that Maryland is significantly impacted by transport and that these states do in fact signifi cantly contribute to Maryland’s nonattainment problem.

Not in keeping with a plain reading of CAA § 107(d) In a letter to Governor O’Malley da ted December 9, 2011on the subject of ozone nonattainment area designations, EPA expressed its view that a large multi-state nonattainment area like the one suggested by Maryland, is “not in keeping with a plain reading of CAA § 107(d)” as it relates to contribu tions from “nearby areas.” We disagree. The United States Court of Appeals for the Distri ct of Columbia Circuit, in its November 29, 2005 decision inCommonwealth of Pennsylvania v. EPA, did not find that Delaware’s request for a large multistate nonattainment area ranging from Virginia to Maine was prohibited by a plain reading of

1the Clean Air Act. Rather, the court states th at while Delaware’s construction of “nearby” maywell be sensible, it would defer to EPA's interpretation that the term “nearby” meant locallybased nonattainment areas within the context of § 107. The Court’s deference to EPA’s expert decision regarding the application of § 107 was again on display in that same case, where the court upheld EPA’s designation of a multi-state nonattainment ar ea consisting of portions of New Jersey, Pennsylvania and Delaware; an apparent expansion of EPA’s limited interpretation of “nearby” previ ously applied in that case. In this regard, we question EPA’s judgment and understanding of the science in re jecting the designation of a large multi-state nonattainment area comprised of states that significantly contribute to nonattainment in Maryland and other Ea st Coast states.

EPA’s assertion that larger nonattainment areas do not coincide with a plain reading of the CAA § 107 is called into question by recent pol icy decisions on air quality designations for
Indian lands 1 . This policy memo refers to Indian trib al lands and adjacent state lands that are much larger than the state of Maryland. For example, the Navajo Nation is nearly the same size as the state of West Virginia 2 , yet this policy memo uses the words “contributing to nonattainment in the adjacent area” when referring to tribal lands’ emissions . Further, the State of Delaware’s February 2, 2012 comment letter to EPA on the proposed designations for the 75 ppb ozone NAAQS, mentions that the word “nearby” must be interpreted as consistent with the scale of ozone transport 3 . The Delaware letter makes a valid observation that EPA’s interpretation of the word “nearby” does not adequately address the impacts of transported ozone pollution on downwind states. Virginia, Pennsylvania and West Virginia are clearly nearby states.

The CAA offers other solutions to the transport problem EPA generalized that the CAA has other solutions to the transport prob lem. We agree, Sections 110(a)(2)(D), § 126, and § 176 and 184 o ffer solutions to transported pollution, if implemented in a timely manner. However, these provisions have not eliminated the significant contribution to Maryland nonattainme nt because these provisions are seldom implemented, or are not adequately implemented to eliminate significant contribution in a timely manner. EPA should exercise its responsibility under § 110(a)(2)(D) to ensure that each upwind state has an approved State Implementati on Plan (SIP) that promptly implements full compliance with § 110(a)(2)(D), or implement a Federal Implementation Plan (FIP) which satisfies that requirement. Yet, even as EP A proposes revocation of the 0.08 ppm ozone, not a single state has a fully approved § 110(a)(2)(D) SIP. State in frastructure and interstate transport SIPs to achieve the new 75 ppb NAAQS for ozone were due by March 20, 2011— nearly one year ago. EPA’s September 22, 2011 guidance memo on designations for the 75 ppb standard acknowledges that “deadlines for some state submissions have already passed, including the infrastructure SIPs and interstate transport SIPs.” The guidance also states that EPA does not intend to penalize states for late submittal of the SIPs. We understand the reasons for EPA’s delay in the process and suppo rted reconsideration of the ozone standard.
The reconsideration issue has b een resolved and we believe th at EPA should move forward to fulfill all of its statutory obligations as quickly as reasonable and avoid further delay.

1 20 Dec 2011 EPA Memorandum, Policy for Establishing Separate Air Quality Designations for Areas of Indian Country

2 http://en.wikipedia.org/wiki/Navajo_Nation

3 State of Delaware, Department of Natural Resources an d Environmental Control, Division of Air Quality, letter to EPA Air Docket dated February 2, 2012

2Notwithstanding the need to promptly implemen t § 110(a)(2)(D) requirements, EPA’s delayed implementation of this remedy leaves Maryland ’s recommendation for the large nonattainment area as the more immediate and timely solution.

Large nonattainment areas are unworkable One of EPA’s chief objections to large nonatt ainment areas is that they are unworkable because it would be too difficult to coordinate the air quality and transportation conformity processes between different stat es and metropolitan planning orga nizations (MPOs) within the large area. We believe that it would be very easy for areas in the large nonattainment area to follow the existing coordination process used in the Philadelphia-W ilmington-Trenton ozone nonattainment area and manage to successfully complete the appropriate CAA requirements and reach attainment. This process uses s ub-regional coordination processes for both air quality planning and transportation conformity.

The Philadelphia-Wilmington-Tren ton ozone nonattainment area that includes four states, two EPA regions, and at least two MPOs, is an exam ple of a larger nonattainment area where the various jurisdictions have a positive record of working together to achieve good air quality. Each state submits a separate SIP selecting the reduction strategies it pr efers. Photochemical modeling, inventories an d attainment demonstrations ar e completed thro ugh an existing regional process that involves multiple states.

Sub regional mobile source emission budgets are utilized to keep MPOs and transportation planning regions intact. EPA Re gions II and III have shown that this arrangement still permits sanctions to be levied agains t a particular state for failure to complete CAA requirements without harm to the other states involved. An example from the Philadelphia-WilmingtonTrenton ozone nonattainment area would be when sanctions were levied against New Jersey for a lapse in their enhanced inspection and ma intenance program without consequence to any other state. While requiring a significant amounted coordinati on, the process in general has worked smoothly. Each state in the nonattain ment area has achieved compliance with the ozone standard in effect at the time by the atta inment deadlines. The important point is that each state would have remained designated as nona ttainment if any of the other states could not achieve attainment. As such, all included states worked toge ther to ensure attainment throughout the multi-state nonattainment area.

Maryland has participated in this process for ove r 20 years and believes that it could easily and seamlessly be implemented in a large nonattainme nt area to successfully comply with the requirements of the CAA while maintaini ng the existing CSA-based air quality and transportation confor mity processes.

Benefits of large nonattainment areas Twenty years of ozone research and air quality monitoring have clearly established the impact of ozone transport on air quality in Maryla nd. At Maryland’s we stern and southern boundaries, we routinely use airplanes, ball oons and mountaintop monitors to measure incoming ozone from upwind states at levels we ll above the current 75 ppb ozone standard. Our sources are already subject to pollution control requirem ents that are among the most stringent in the nation. Implemen tation of even the most robust additional local controls will not solve our air quality problems and bring us into attainment by the statutorily required deadlines. Recent modeling, included in Appendi x C, shows that Maryland does not attain the

375 ppb standard when all “in-state” emissions ar e zeroed out. Establishment of a large multistate ozone nonattainment area is an im portant step to address transport.

Maryland advocates for a large nonattainment area as a way to adequately address transport. As stated above, interstate tr ansport has significantly affect ed Maryland for quite some time and we have invested considerable funds to provide valid scientific data to demonstrate this fact. A large nonattainment area will help Maryland in several ways. A nonattainment designation imposes a number of requirements on an area, including requirements for emission controls. At a minimum, it imposes a requireme nt to add state of th e art controls on new sources instead of maintaining the advantage of allowing new sources into greenfield areas without controls. A number of new power pl ants have located just outside Maryland nonattainment areas to avoid this requiremen t. Enlarging the nona ttainment area would prevent such occurrences, pr ovide a more level economic playing field, and minimize additional upwind emissions.

A large nonattainment area also forces the entire area to rema in designated as nonattainment
until each monitor in the nonattainme nt area can comply with federal air quality standards. This ties the source of transported emissions to the affected monitor, and thus provides the incentive for each state in the nonattainment ar ea to fulfill its 110(a) (2)(d) responsibilities promptly. EPA’s policy of reviewing air quality data by beginning with the violating monitor and geographically ending the nonattainment area when monitors measuring attainment are found does not have much justification when one considers what is known about long range transport.

Under EPA’s current designation proposal, the Baltimore Nonattainment Area would be the
lone moderate nonattainment area on the East coas t. We alone would be required to implement more controls at generally more than 4 to 8 tim es the cost of controls EPA plans to impose on states under the Cross-State Air Pollution Rule (CSAPR), a rule which only addresses the 0.08 ppm standard. Modeling for CSAPR indicates that 10 or more ppb of an average ozone concentration in Maryland co mes from states contiguous to Maryland. Surely those “contiguous” areas should satisfy a plain read ing of the word nearby under § 107. In addition, a large nonattainment area including “contiguous” states would ha ve the practical effect of reducing emissions from more than just power plants. The 10 ppb transported into Maryland are not simply attributable to power plant em issions but to emissions from other sectors especially the mobile sector. A large nonattainment area would require each area in that designated nonattainment area to adopt controls for multiple sectors, a result which EPA indicates will be needed to achieve the 0.08 ppm ozone NAAQS in the CSAPR preamble.

Maryland has adopted a broad spec trum of controls, many of them statewide, in a quest for good air quality. These controls have come at gr eat expense to its citizens. As noted above, Maryland’s industrial sour ces are already subject to stringent air pollution control requirements and have been for many years. For example, Maryland’s Healthy Air Act (HAA) is among the most stringent, if not the most stringent, coal -fired power plant control program in the East. Since 2008, Maryland utilities have invested almo st $3 billion to clean Maryland’s air. Maryland has adopted the Californi a Car Program, and we continue to implement a centralized motor vehicle inspection and maintenance progra m. Maryland has worked closely with the other states that are part of the Ozone Tr ansport Commission (OTC) and the EPA Regional

4Offices who are members of the OTC technica l committees, to identify and implement all potential additional control programs that can m eaningfully reduce ozone concentrations. Over the past 30 years, we have adopted hundreds of air pollution regulations that reduce emissions from every feasible category ranging from pow er plants to perfume manufacturers. The average cost of ozone precurs or pollution controls in Maryland is between $2,000 and $3,000 dollars per ton of pollution redu ced. Some of our control e fforts approach the $5,000 to $6,000 per ton range. These relatively expensive control programs improve ozone air quality by only a very small amount, and they place Maryland sources at a significant economic disadvantage in relation to their competitors in upwind st ates that are significantly contributing to nonattainment in Maryland, but are not subject to these kinds of controls. Widespread lower cost regional control programs are significantly more cost-effective and have been shown to drive very large reduc tions in ozone concentrations. Mo st recently, for example, the CSAPR used a $500 per ton ceiling to define required controls. Establishing larger multi-state nonattainment areas would help level the econom ic playing field by re quiring lower-cost controls of the type already implemented in Maryland throughout the la rge nonattainment area.

In your December 9, 2012 letter and other EPA letters you imply that EPA’s current efforts to address transport throug h rules like the CSAPR and other prov isions of the CAA can be used to address transport and provide the promise of clean air in the timeframe mandated in the Act. Our science shows us that, with no uncertaint y, it will be impossible for Maryland as well as other states to attain the 75 ppb standard on ti me. We believe the only way to achieve our public health protection goal is to establish the large nonatt ainment area we recommended as this will require all contributing areas to work as hard as Maryland to reduce emissions or face the penalties and sanctions that only a pply to nonattainment areas under the CAA.

We are anxious to work in partnership with EPA to achieve our shared public health goals. We believe, however, that EPA’s current policy on nonattainment boundaries will not allow Maryland to meet CAA public heal th protection deadlines. Equally important are our concerns over how EPA’s approach may adversely impact on Maryland’s economic recovery efforts. The small nonattainment area would drive Maryla nd to adopt minimally effective, extremely expensive control programs wit hout insuring that the highly effective, much more costeffective control programs in upwind, contributi ng states are required. This does not make environmental or economic sense.

Marginal Areas Unlikely to Attain By 2015 Due to Lack of Reductions EPA has delivered many control programs, especial ly in sectors that the CAA prohibits states from regulating. These sectors include on and off road vehicles. States can expect continuing reductions from several of these regulations . EPA has announced intentions to propose additional tailpipe regulati ons, Tier 3, for light duty vehicles. These national rules are fair and very cost-effective and we encourage EPA to conti nue this practice. Due to their nature, some regulations unfortunately will not deliver suffi cient reductions in the timeframes needed to
reach attainment.

Maryland believes that EPA’s proposed designations unduly penalize the Baltimore nonattainment area. EPA professes that marginal nonattainment areas will ease into attainment over the next 3 years. Attainment monitoring must begin in 2013. The following analysis of rules that might provide enforceable measures to achieve attainment s hows that few emissions reductions will take place in this timeframe. Preliminary modeling shows that deep reductions

5are needed to achieve the 75 ppb ozone standa rd. Even EPA’s CSAP R modeling shows many
areas fall short of attainment with the currently adopted suite of reduction strategies. This problem is compounded by the fact that areas classified as marginal nonattainment are not required to implement specific reduction m easures under the CAA. Without ensuring emissions reductions from upwind areas by linking their attainment status to those areas to which they are significantly contributing, EPA is minimizing those same upwind reductions needed for downwind nonattainment areas to achieve the NAAQS.

The National Association of Clean Air Agencies (NACAA) 4 , including Maryland, has developed a list of the top seven source categories for federal air pollution emissions controls. The list focuses on the source categories that are most important to control to help nonattainment areas with attainment of the national air qual ity standards. These seven categories represent 85% of the NO
x , 75% of the SO2 and 75% of the Hg left to regulate.

1. On-road vehicles 2. Electric generating units (EGUs) 3. Industrial, commercial & institutional (ICI) boilers 4. Cement kilns 5. Locomotive engines 6. Marine engines
7. Aircraft

EPA has promulgated a number of strong national regulations regarding these seven source categories, to try to improve ai r quality across the country. These programs control stationary and mobile sources nationwide. In doing so, they reduce not only in-state pollution but also pollution that crosses state borders and contri butes to violations of national air quality standards in downwind areas. At the same time that these rules are highly beneficial, they fall short for the following reasons:

• Many measures do little or nothing in time for nonattainment areas to achieve clean data starting in 2013 for “marginal” areas and 2015 for “moderate” areas. Maryland fully supports these rules, but they simply provide reductions that are too late to help states with the 75 ppb ozone standard:

 On-Road Vehicles (Tier 3)

 EGUs, ICI Boilers and cement kilns (CSAPR II)

 Locomotives Engines (small engine rule)

 Marine Engines (small and large engine rules)

 Aircraft (Tier 8 standard and nonroa d rule regarding ground equipment).

• Some recently implemented regulations on th e aforementioned categories offer few, if any, NO
x emission reductions. They miss an ozone precursor that is crucial to ozone
emissions reductions:

 EGUs (Mercury and Air Toxics Standards)

 ICI Boilers (Maximum Achi evable Control Technology)

 Cement Kilns (New Source Performance Standards and MACT)

4 Resolution 10-01 of the Ozone Transport Commission Ca lling on the US Environmental Protection Agency to Adopt and Implement Additional National Rules to Re duce Ozone Transport and Protect Public Health

6• One key measure, in the works for more th an a decade, was never designed to address the 75 ppb ozone standard, and, at this point, it is mired in the courts with its future completely uncertain:

 EGUs (Cross-State Air Pollution Rule, and prior Clean Air Interstate Rule)

An easier approach to addressing the transport of pollution is to designate large, multi-state
nonattainment areas. The benefits of this approach include the following:

• Upwind areas implement effective lower cost programs that have likely already been developed, tested, implemented, a nd refined in downwind areas.

• Upwind areas of concern are included in multi-state efforts to attain air quality standards in downwind areas that are not able to reach attainment on their own, thereby focusing limited resources where they are most needed.

• Upwind and downwind areas implement the same controls, creating equity for
businesses in different locations and equity in their work.

In summary, while Maryland applauds EPA’s great efforts on national rules, we urge EPA to designate large, multi-state nonattainment areas. Maryland will not be able to attain the 75 ppb ozone standard with the federal measures alone.

Below are details on the timing of federal meas ures pertaining to the top seven source categories.

1. On-road vehicles

We expect to see significant reductions from on-road vehicles if EPA, as expected, goesthrough with developing proposals for Tier 3 vehicle requirements and low sulfur fuel for onroad vehicles. A notice of proposed rulemaking (NPRM) for Tier 3 for light-duty vehicles is expected in approximately March 2012, with a fina l rule due in mid to late 2012. In the white paper, “ Cleaner Cars, Cleaner Fuel, Cl eaner Air: The Need for and Be nefits of Tier 3 Vehicle and Fuel Regulations, ” October 31, 2011, NACAA estimates that the Tier 3/ low sulfur fuel regulations, including both the Tier 3 program and the low sulfur fuel program, will reduce
NO
x emissions by 8 percent by 2017 nationally for on-road light duty vehi cles and 29 percent by 2030, and it will reduce VOC levels 3 percent by 2017 and 26 percent by 2030.

NESCUM, in the presentation “Benefits and Cost s of Tier 3 Low Sulfur Gasoline Program,” Arthur Marin, CT DEEP SIPRAC Meeting, January 12, 2012, estimates higher emissions
reductions benefits than NACAA and provides more deta il on the proportion of NO
x and VOC emissions reductions from the Tier 3 portion of the rule compared with the low sulfur fuel portion of the rule. Specifically, the NE SCAUM presentation indicates Tier 3 NO
x emissions reductions of 16 percent in 2017 and 59 percent in 2030, and VOC reductions at 4 percent in 2017 and 32 percent in 2030. NESCAUM estimates the low sulfur fuel NO
x emissions reductions at 25 percent, or 177,500 tons, if th e Northeast and Mid-Atlantic States, the Midwest (eight states), and th e Southeast (ten states) were included. NACAA indicates that these latter NO
x benefits, from reducing the sulfur in fuel would be immediate.

7Maryland is glad to see EPA working to implem ent Tier 3 and low sulfur fuel, and urges EPA to propose and finalize this rule on sche dule, in 2012. The lo w sulfur fuel’s NO
x emissions reductions would be immediate, although the re ductions from Tier 3 would be too late, 2017 and 2030, to help marginal areas show clean mo nitoring data starting in 2013 and moderate areas starting in 2015.

2. Electric generating units (EGUs)

EPA has been moving ahead with regional contro l programs such as the final Cross-State Air Pollution Rule, published in the Federal Regi ster in August 2011. On December 30, 2011, however, the U.S. Court of Appeals issued a temporary stay of CSAP R and ordered EPA to continue to administer the Clean Air Interstate Rule (CAIR) during CS APR’s stay. CAIR is only in place temporarily until CSAPR is resolved and restored as CAIR’s replacement rule. This makes the status of both CAIR and CSAPR very tentative. It also means that the implementation of CSAPR will be further delayed, resulting in additional delays in the control of emissions from sources upwind of Maryland and great difficulty in Maryland’s efforts to achieve clean data starting in 2013 and 2015.

CSAPR II, the rule that was to fo llow CSAPR and provide additional NO
x reductions in accordance with states meeting the 75 ppb ozone st andard is now also extremely uncertain. Prior to the court stay on CSAPR, CSAPR II had a suggested proposal date in the 2013 timeframe. In order to have clean monitoring data starting in 2015, if not 2013, in addition to nonattainment areas needing CSAPR implemented this year, nonattainment areas need CSAPR II proposed in 2012 and finalized in 2013.

Also, EPA has proposed national standards, particularly the EGU MACT known as the “Mercury and Air Toxics Standards” (MATS) , published in the Federal Register on May 3, 2011. The final rule was released in unoffici al copy on December 16, 2011 and is expected to be published in the Federal Register on Februa ry 16, 2012. While the EGU MACT is expected to result in substantial reductions in SO 2 from gas scrubbers installed to remove toxic air pollutants, particularly HCl and acid gases, SO 2 is not an ozone precursor, and the rule does not reduce emissions of the ozone precursor, NO
x . Nonattainment areas need additional NO
x reductions from EGUs across the country, by 2013 or 2015.

3. Industrial, commercial and institutional (ICI) boilers

The ICI Boilers MACT, “National Emission Sta ndards for Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and Instituti onal Boilers and Process Heaters” finalized on March 21, 2011, dramatically reduces SO 2 and toxic pollutants; however, it does not reduce
NO
x emissions. As with the case of EGUs, we need additional NO
x reductions from ICI boilers. States have asked EPA to include this in CSAPR II, but as noted above, CSAPR II is, in effect, not even on the radar screen for EPA. In order to have clean monitoring data starting in 2013 or 2015, states urge EPA to propose CS APR II in 2012 and finalize it in 2013. It is essential to include NO
x reductions from ICI boilers.

84. Cement kilns

On August 6, 2010, EPA issued amendments to the NSPS and MACT requirements for Portland Cement Plants. These rule revi sions will provide small reductions in NO
x but significant reductions in VOCs and other pollutant s. EPA estimates that when these programs are fully implemented in 2013, that VOCs (total hydrocarbons) will be reduced 83 percent and
NO
x 5 percent. Overall, more NO
x reductions are needed from this source category. EPA agreed to consider including cement kiln NO
x reductions in CSAPR II, but as noted above, CSAPR II is, in effect, not even on the radar screen for EPA. In order to have clean monitoring data starting in 2013 or 2015, states need CSAPR II proposed in 2012 and finalized in 2013. It is essential to include NO
x reductions from cement kilns.

5. Locomotive engines

The 2008 rule, “Locomotive Engines and Marine Compression-Ignition Engines Less Than 30 Liters per Cylinder,” provides dramatic reductions in NO
x and diesel PM emissions from newly built and remanufactured locomotive engine s. Unfortunately, these emission reductions will occur too late to help nonattainment areas achieve clean monitoring data by 2013 or 2015.

As noted under “Marine engines,” below, EPA es timates that by 2030, with fleet turnover, this rule, including both the locomotive and marine engine standards, will result in NO
x reductions of 80 percent, or 800,000 tons, and PM reduction s of 90 percent, or 27,000 tons, from newly built engines that meet the Tier 4 standards in th is rule compared with engines that do not (see 73 FR 37096). These same reductions are cite d again below, under “marine engines.”

The standards for remanufacturing of locomotive e ngines were scheduled to take effect as early as 2008, as soon as certified remanufacture systems were available, according to the EPA rule “Control of Emissions of Air Pollution FromLocomotive Engines and Marine CompressionIgnition Engines Less Than 30 Liters per Cylinde r; Republication,” (73 FR 37096). Near-term, Tier 3, standards began to phase in starting in 2009, and the Tier 4 standards begin to take effect in 2015 for locomotives.

While these NO
x reductions are significant, they do not address the legacy fleet. These standards, going into effect in the 2008-2015 tim eframe, will be slow to show an impact on
NO
x emissions due to the low turnover of the existing fleet.

Another rule should have a slightly sooner impact on NO
x from engines in the existing fleet of locomotives: The Non-Road Diesel Rule finaliz ed in May 2004, decreases sulfur levels in non-road diesel fuel that will help prevent da mage to the emission-control systems and that will reduce NO
x and particulate matter from engines in the existing fleet of locomotives, while reducing engine maintenance cost. This rule wa s to reduce sulfur levels from about 3,000 parts per million (ppm) to 500 ppm in 2007 and is to reduce sulfur levels further, to 15 ppm, when fully implemented in 2012. This constitutes a reduc tion of sulfur in fuel of greater than 99 percent from the baseline value.

Overall, EPA projects that this ru le will result in 738,000 tons of NO
x reductions and 129,000 tons of particulate matter reductions by 2030. EP A is not clear what proportion of these NO
x reductions are from the lower sulfur levels in the fuel. EPA analyses for this rule do not

9address this question. Cleaner en gine standards are al so included in the rule, and while they are expected to substantially reduce NO
x , they are not applicable to the locomotive engines. Only the low sulfur fuel standard is applicable to locomotives.

Overall, it remains to be seen if the low sulfur fuel program in the Non-Road Diesel Rule may have some benefits for NO
x reductions in locomotives. If it does provide these benefits, though, the program’s 2007-2012 implementation sche dule means that the benefits would be seen by the time states need clean monitoring data, in 2013 or 2015.

6. Marine engines

The 2010 rule, “Control of Emissions from New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder,” esta blishes two additional tiers of NO
x standards for newly built Category 3 (very large) marine diesel e ngines in the U.S.: Tier 2, which began in 2011 and is expected to result in a 15 to 25 percent reduction in NO
x compared with Tier 1 levels; and Tier 3, which will apply beginning in 2016.

The 2010 rule above also establishes emissions standards for VOCs and CO; provisions to allow for the production and sale of fuel cont aining 1,000 ppm sulfur for use in Category 3 marine vessels, which will also help reduce NO
x emissions; and an emissions control area (ECA) up to 200 nautical miles off U.S. coasts, whic h will reduce global levels of sulfur in fuel and thereby also reduce NO
x emissions. The 1,000 ppm sulfur in fuel standard will enter into force in January 2015.

In addition, in this rule, EPA is adopting engi ne and fuel standards from the international MARPOL Annex VI treaty. These standards will apply to both U.S. and foreign-flagged ships in U.S. ports and internal waters.

Overall, according to the EP A’s “Regulatory Announcement: EPA Finalizes More Stringent Standards for Control of Emissions from New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder,” EPA 420-F-09-068, dated December 2009,” by 2030, when the above marine engine strategy included in the 2010 rule is fully implemented, it is expected to reduce NO
x emission rates by 80 percent, or 1.2 m illion tons, and PM emission rates by 85 percent, or 143,000 tons, “compared to the cu rrent limits applicable to these engines.”

While these NO
x reductions are significant, they do not address the legacy fleet. These standards will be slow to show an impact on NO
x emissions due to the low turnover of the existing fleet. This is reflected in the expectation that the full NO
x emissions reductions of the marine engine strategy will not be realized until 2030. As a result, th is rule will provide little if any assistance to states that need cl ean monitoring data starting in 2013 or 2015.

The 2008 rule regarding smaller engines, “L ocomotive Engines and Marine CompressionIgnition Engines Less Than 30 Liters per Cylinde r,” also provides dramatic reductions in NO
x and diesel PM emissions from small and medium sized, Category 1 and 2, newly manufactured marine diesel engines and remanufactured large marine diesel engines. Unfortunately, these emission reductions will occur too late to help nonattainment areas achieve clean monitoring data starting in 2013 or 2015.

10As noted under “Locomotive engines,” above, EPA estimates that by 2030, this rule, including both the locomotive and marine engine standards, will result in NO
x reductions of 80 percent, or 800,000 tons, and PM reductions of 90 percen t, or 27,000 tons, from newly built engines
that meet the Tier 4 standards in this rule compared with engines that do not (see 73 FR 37096).

The standards for remanufacturing of marine engine s were scheduled to take effect as early as 2008, as soon as certified remanufacture systems were available, according to the EPA rule “Control of Emissions of Air Pollution FromLocomotive Engines and Marine CompressionIgnition Engines Less Than 30 Liters per Cylinde r; Republication,” (73 FR 37096). Near-term, Tier 3, standards began to phase in starting in 2009, and the Tier 4 standards begin to take effect in 2014 for marine diesel engines.

While these NO
x reductions are significant, they do not address the legacy fleet. These standards, going into effect in the 2008-2014 tim eframe, will be slow to show an impact on
NO
x emissions due to the low turnover of the existi ng fleet. As a result, this rule will provide little if any assistance to st ates that need clean monito ring data starting in 2013 or 2015.

Another rule should have a slightly sooner impact on NO
x from engines in the existing fleet of marine engines, same as with the locomotives: The Non-Road Diesel Rule finalized in May 2004, decreases sulfur levels in non-road di esel fuel, and in doing so, reduces NO
x and particulate matter from engines in the existing fl eet of marine engines (particularly C-1 and C2). This rule was to reduce sulfur levels from about 3,000 parts per million (ppm) to 500 ppm in 2007 and is to reduce sulfur levels further, to 15 ppm, when fully implemented in 2012.
This constitutes a reduction of sulfur in fuel of greater than 99 percent from the baseline value.

Overall, EPA projects that this ru le will result in 738,000 tons of NO
x reductions and 129,000 tons of particulate matter reductions by 2030. EP A is not clear what proportion of these NO
x reductions are from the lower sulfur levels in the fuel. EPA analyses for this rule do not address this question. Cleaner en gine standards are al so included in the rule, and while they are expected to substantially reduce NO
x , they are not applicable to the marine engines, as they were not applicable to locomotive engines, abov e. Only the lower sulfur fuel standard is applicable.

Overall, it remains to be seen if the low sulfur fuel program in the Non-Road Diesel Rule may have some benefits for NO
x reductions in marine engines. If it does provide these benefits, though, the program’s 2007-2012 implementation sche dule means that the benefits would be seen by the time states need clean monitoring data, in 2013 or 2015.

7. Aircraft

In 2005, EPA adopted a more stringent round of standards from the United Nations International Civil Aviation Orga nization (ICAO), for some gas tu rbine engines. In July 2011, EPA released a draft rule establishing more stringent Tier 6 and Tier 8 NO
x emissions

11standards for newly-certified 5 and newly-manufactured airc raft engines, making their emissions consistent with ICAO 2010 NO
x standards. As of early February 2012, EPA expected to finalize this rule by the summer of 2012.

The Tier 6 NO
x standards for newly-certified gas turb ine engines with ra ted thrusts of 89 kilonewtons (kN) or more vary from an 8 pe rcent to a 12 percent reduction from Tier 4 standards. The Tier 6 NO
x standards for newly-certified gas tu rbine engines with rated thrusts greater than 26.7 kN and less th an 89.0 kN vary from a 0 percent to a 12 percent reduction from Tier 4 levels, dependent on both the pres sure ratio and rated thrust of the engine.

Tier 8 NO
x standards for newly-certified turbofan e ngines with rated thrusts of 89 N or more are considered 15 percent more stri ngent than the proposed Tier 6 NO
x standards at a pressure ratio of 30, the standard point of comparison. Tier 8 NO
x standards for newly-certified gas turbine engines with ra ted thrusts greater than 26.7 kN but less than 89.0 kN vary from a 5 percent to a 23 percent reduction fr om Tier 6 standards. EPA notes that since the effective date of the Tier 6 NO
x standard was January 1, 2008, and “n early all in-production engines currently meet this standard,” EPA focused their discussion in the rule (76 FR 45041) to engines that needed to comply with the Tier 8 NO
x standard.

Accordingly, EPA found that th e landing and takeoff (LTO) NO
x reductions from Tier 8 would be approximately 5.5 percent worldwide in 2026 and 7 percent worldwide in 2036 relative to the baseline. In the U.S., this would be e quivalent to approximately 5,200 tons in 2020 and 8,700 tons in 2030. Cumulative reductions from the implementation of Tier 8 in 2014 to 2030 are projected to be approximately 100,000 tons of NO
x [see 76 FR 45041 and related citations from various working and analysis groups of the ICAO Council’s Committee on Aviation Environmental Protection (CAEP)].

With regard to newly manufactured engines, 6 only Tier 6 standards a pply at this time, although EPA states that, depending upon ICAO actions, they may later consider requiring these engines to comply with Tier 8 standards (76 FR 45034).

Newly manufactured engines that we re originally certified “prior to the effective date of the... rule may continue production without mee ting the proposed Tier 6 standards through December 31, 2012. After that date, these engi nes must comply with the proposed Tier 6 standards” or cease production (“EPA Proposed NO
x Emission Standards for Aircraft Gas Turbine Engines,” EPA, Office of Transpor tation and Air Quality, EPA-420-F-11-019, July 2011, page 1).

Overall, due to the long timeframe, 2014-2030, for implementation of Tier 8 and realization of the emissions reductions from Tier 8, the aircraft standards will not help nonattainment areas meet their 2013 and 2015 clean monitoring data n eeds. Maryland urges EPA to provide much more support toward nonattainment areas’ attainment of the 75 ppb ozone standard.

5 5 According to EPA (76 FR 45021), “the ICAO standards describe newly certified engines as ‘...engines of a type or model for which the date of manufacture of the first individual production model was after...’ the effective date of the emission standards.

6 “Newly manufactured engines” are “those that have be en previously certified and manufactured in compliance with preexisting standards, and will continue to be produced after the effective date of a new applicable standard.” (76 FR 45021)

12Besides aircraft emissions standards, EPA ha s promulgated rules controlling emissions from airport equipment. EPA established and phased in emissions standards for new nonroad diesel engines, including certain aircraft ground support equipment, from 1994-2008. Tier I standards reduced NO
x emissions by 30 percent from engines greater than 37 kilowatts. Tier 2 emissions standards covered all en gine sizes and further reduced NO
x , hydrocarbons, and PM. Tier 3 standards, for engines of 37-560 kW, fu rther reduce nonroad diesel engine emissions by 60 percent for NO
x and 40 percent for PM, compared to Tier 1.

New nonroad spark ignition (SI) engines above 19 kW, which includes some airport equipment, have been required since 2007 to incl ude optimized engines. These engines must include new diagnostic systems, in order to m eet more stringent stan dards calling for a 90- percent reduction in NO
x , HC, and CO emissions. According to EPA’s “Final Regulatory Support Document: Control of Emissions from Unregulated Nonroad Engines,” EPA420-R-02- 022, September 2002, the industrial spark-igniti on nonroad engines greater than 19 kW covered in EPA’s 2002 rule, “Control of Emi ssions From Nonroad Large Spark-Ignition Engines, and Recreational Engines (Marine and Land-Based),” are projected to achieve the following in 2020: VOC reductions of 89%, or 284,000 tons, and NO
x reductions of 91%, or 429,000 tons. Note that these projection emissi ons reductions include airport equipment as well as other nonroad large spark-ignition engines.

While these standards for airport equipment have already gone into effect and should start to help nonattainment areas in their efforts to ach ieve clean monitoring data starting in 2013 and 2015, the full benefits of this ru le will not be realized until at least 2020. Nonattainment areas need additional support from EPA toward attainment of the 75 ppb ozone standard.

13

## APPENDIX A 5 (9) – FACTOR ANALYS IS FOR THE 16 STATE NONATTAINMENT AREA

Since the 1990 Clean Air Act Amendments (CAAA) passed, EPA has used a 9 factor analysis
to determine the boundaries of nonattainment areas. In the early 1990s this methodology supported the CAAA enlargement of nonattainment areas to have boundaries coincident with
the boundaries of consolidated metr opolitan statistical areas. It was also in keeping with the theory at that time that transport was short range , mostly from large metropolitan area to large metropolitan area. This theory formed the basis for creating the Northeast Ozone Transport Region.

During the Ozone Transport Assessment Group delib erations just before the turn of the century, scientific evidence came to light that l ong range transport had a similar if not larger affect on ozone levels in the east. EPA promulgated the NO
x SIP Call, the first long range transport rule, as a result of these findings. EPA utilized the same 9-factor methodology in designating areas for the 1997 0.08 ppm ozone standard in 2004. However, designations for the 1997 PM2.5 standard appeared to consider th e sources of pollution more heavily in the designation process and, of late, SO2 and NO2 desi gnations also seem to consider the nature of the pollutant more and adapt the designation proce ss to the particular pollutant. Yet, despite a better understanding of the science of transport and its role in produc ing high ozone levels, EPA still employs the same 9 factor analysis, currently condensed into 5 factors. EPA evaluates the factors in the same way as before with no apparent cons ideration of long range transport or current scientific evidence. EPA ha s not been able to promulgate a regulation to control long range transport so that controls ar e in place to provide improved air quality prior
to attainment deadlines. EPA has the disc retion to modify the evaluation criteria for designating area boundaries to account for long ra nge transport. The designation process
should include such a factor in designating nonattainment areas now and in the future as it is the responsibility of a state to control significant pollution co ntribution to other areas.



### Air quality data EPA reviews the design values for ozone monito rs to locate violating monitors. EPA then
establishes nonattainment area s around those monitors expand ing outward and geographically ending the nonattainment area when monitors m easuring attainment are found. Certainly this technique is a good foundation but fa lls far short of examining othe r air quality data that should factor into designations, especia lly in light of what is known about long range transport.

Our 20 year ozone research program shows cl early that the number one contributor to Maryland’s high ozone level is an elevated reservoir of high transported ozone that forms and collects in the middle of the night . This elevated reservoir is trapped at about 2000 feet above the earth’s surface by a nocturnal inversion and can be pushed by elevated nighttime winds for hundreds of miles in a single night. Maryland ha s hard, measured (not modeled) data, from airplanes, balloons, mountaintop monitors, wind pr ofilers and other measuring equipment that confirm the above conclusions. Our monitors show that as the nocturnal inversion begins to

14break up, the aloft ozone, routinely measured at levels above 75 ppb, slowly mixes down to earth. The elevated reservoi r is created by emissions from nearby, upwind states.

We also have empirical evidence of emissions transported by the nocturnal low level jet (NLLJ). This is a strong southwest wind along easte rn side of the Appalachian Mountains that runs very close to the ground. It begins at sundo wn and can last until dawn. It can start as far south as North Carolina and can reach as far north as New Jersey, Massachusetts, and Connecticut. Given an average speed of 30 mph, a NLLJ that runs for 7 hours carries gases and particulates 210 miles. Data collected simulta neously from wind profilers and ozonesondes has revealed that ozone is transported via the low le vel jet. Lidar data reveals similar transport for particulate matter.

This air quality data is more difficult to find and evaluate but does lend proof those areas of
influence should be included in the areas of nonattainment they affect. EPA claims o ne natural reading of Section 107 is that an area must be designated nonattainment if it “contributes to nonattainment” in a “nearby area” at the time EPA promulgates the final designations pursuant to section 107. The areas Maryland recommended for inclusion in a nonattainment area with Maryland do contribute to our nonattainment at this time.



### Emissions and emissions-related data Once an independent factor, EPA now combines emissions related data with the emissions
factor. EPA interprets emissions-related data to include actual and estimated emissions of VOC
and NO
x from sources, such as the data available in the latest National Emissions Inventory available, and to include the latest information and trends for Vehicle Miles Traveled (VMT) and commuting, and population characteristics and trends of the area (growth factors). Population, VMT and commuting patterns and growth fact ors were once independent factors. Traffic and commuting patterns- loca tion of non point source emissions

Controlling transported pollution is very im portant in attaining the ozone NAAQS to downwind states such as Maryland. In some areas of Maryland we need controls in place beginning in 2012 to meet 2015 attainment dead lines for the 75 ppb ozone NAAQS. In other
areas such as the Baltimore se rious nonattainment area, additional transport reductions are needed immediately to prevent this area from becoming classified as severe by the end of 2014. Judgments regarding air quality complian ce with the 0.08 ppm standard are on-going. EPA modeling from the CSAPR shows that 5-10 ppb of Baltimore’s design value are attributable to transport. Subtracting 10 ppb from Baltimore’s current design value of 92 ppb would allow Baltimore to attain the 0.08 ppm st andard and be at the same starting point, nonattainment for the 75 ppb standard only, as other states in the eastern U.S.

Transport becomes central to attainment in more and more states with every lowering of the NAAQS. Specifically, with ev ery decrease in the NAAQS, the proportion of the NAAQS represented by transported polluti on in these states increases. Meteorologists and atmospheric chemistry researchers at Howard University, th e University of Maryland, and other institutions have documented the impact that meteorology and air transport pr ocesses such as the nocturnal low level jet (NLLJ) and the elevated ozone reservoir have on local emissions levels.

Local measures in Maryland have been all but exhausted. Maryland fully agrees that in the past many local emission reductions were n ecessary. Maryland developed and implemented

15necessary regulations with the involvement of our state’s industry leaders. These regulations have resulted in large reduc tions in Maryland emissions. For example, Maryland has implemented the state’s Healthy Air Act, which is reducing NO
x levels from electric generating units (EGUs) by approximately 75% from 2002 levels, in addition to significant reductions in SO 2 and mercury. Emissions from mob ile sources, including onroad, nonroad, marine, air, and rail, also conti nue to contribute significantly to NO
x and VOC emissions levels, but the setting of mobile emissions standa rds is outside the authority of most states to regulate. Very deep, additional regional reductions of NO
x will be needed for Maryland to attain the new ozone standard.

Many of the states Maryland proposed includi ng in the large nonatt ainment area meet the criteria EPA says it uses to include a n earby area in a nonattainment designation. NO
x emissions for these states are quadruple the NO
x emissions from Maryland. Some of these sources are controlled but many are not and modeli ng shows they have an effect on Maryland’s air quality. Emissions per capita in these states are greater than emissions per capita in Maryland. Many of these states export power in to Maryland and other states and do so in a regulated environment where control costs are pa ssed on to the consumer. Not including them in the nonattainment area is a direct disadvant age to Maryland sources which are deregulated and operate in a merchant situat ion. This encourages growth in emissions in these states as most plants are not yet oper ating at maximum capacity.

State Population (2010 census) 2010 NO
x lbs (EPA CAMD) 2010 Per Capita NO
x Emissions (lbs/per person)
MD 5,773,552.00 37144200 6.43
PA 12,702,379.00 250972400 19.76
VA 8,001,024.00 66169600 8.27
WV 1,852,994.00 102785600 55.47
IN 6,483,402.00 241848000 37.30
KY 4,339,367.00 183648600 42.32
NY 19,378,102.00 47421800 2.45
NC 9,535,483.00 99222400 10.41
TN 6,346,105.00 61979200 9.77

MI 9,883,640.00 152260000 15.41

There is no doubt that Maryland is highly urbanized containing a large city and half the suburbs of the nation’s capital. Its small geographic size accentuates that density. Many of the states we requested as part of the large nonattai nment area are much larger in square miles and though they have major cities, th eir population density is diluted with the additional geographic area. These cities are experiencing growth just as Maryland is, yet they are not required to offset the growth in emissions that accompan ies growth in population the way Maryland will
be as the lone moderate nonattainment area in the east.

Growth in emissions includes growth in VMT, growth in area sources and growth in nonroad sources as well as growth in point sources and EGU capacity. Most, if not all, of these areas

16will do infrastructure planning w ith no mobile source emissions budget-only the build/no build test which supports growth in mobile source emissions. The large geographic areas of these states encourage growth in VMT. Mary land has taken numerous steps to both reduce emissions through technological measures and to encourage reductions in VMT. We are currently waiting to implement our Clean Cars program and are implementing aspirational conformity goals. These are difficult steps to take when they are not echoed in surrounding states and they do little to improve air quality in your own state.



### Meteorology The next factor is Meteorology, which includes weather and tran sport patterns. The EPA uses 30-year average summer surface- level wind directions to help identify ozone nonattainment
boundaries.

a. Local Transport MDE agrees with the EPA finding that the mete orological data does not provide a basis for separating the Baltimore and Washington, DC nona ttainment areas. In fact, “[s]everal Maryland counties in the current Washingt on DC-MD-VA nonattainment area are most frequently upwind of and most proximate to a violating monitor in the current Baltimore
nonattainment area.”

b. Regional Transport However, climatological surface wind direction only tells part of the meteorological story. Surface wind roses do not represent the three-dime nsional flow of air in the atmosphere. Transport patterns based solely on surface wind speed and direction ignores aloft winds and regular vertical mixing such as occurs in the da ily cycle of the planetar y boundary layer (PBL). Objective, hierarchical clusters based on three- dimensional wind fields provide a more realistic representation of the origins of air during oz one exceedance days (see, e.g., Hains et al., 2008 and Taubman et al., 2006).

Chemical lifetimes are longer and transport fast er in the lower free troposphere than at the surface and, as a result, ozone and ozone precu rsors are commonly carri ed hundreds of miles from their sources. Following transport, air in the lower free troposphere mixes down to the surface as the nocturnal inversion breaks down due to solar heating in the mornings of ozone exceedance days. The relevant mixing layer for pollutants can vary in depth during a 24-hour period from less than 100 m at night to more than 1,000 m on a warm and sunny day.

Due to interstate transport, Maryland’s ozone is essentially a regional rather than a local problem. Frequently, during the morning hours of an ozone exceedance day, a large reservoir
of ozone that has been trans ported into Maryland from other states via the stronger winds above the boundary layer sits over Maryland a nd the Mid-Atlantic area waiting to mix down (see Figure 3-1). Based on ozone data collected at mountain top monitoring stations (aircraft and ozonesondes too), ozone levels in the rese rvoir can routinely reach 60 to 100 ppb during the late night and early morning hours. In cont rast during the morning hours, ozone levels at the surface are very low. Normally, around 10:00 or 11:00 AM, the nocturnal inversion breaks down and ozone in the reservoir mixes down to the surface and significantly degrades air quality. Since the air that mixe s down has ozone levels at or near the 8-hour ozone NAAQS, no amount of local controls will help preven t an ozone exceedance day from occurring.

17Figure 3-1. Timing of the mixing down of the aloft ozone reservoir from mountain top measurements on June 8, 2011, from MDE.

c. Scientific Evidence There is an extensive body of scientific findings proving th at regional transport plays a significant role in urban high ozone episode s in Maryland. During the summer ozone season, scientists from the University of Maryland College Park (UMD), Howard University (HU), University of Maryland Baltimore County (U MBC) and others have used aircraft, ozonesondes, and remote sensing techniques to show that both ozone and its precursors are transported from nearby upwind states into Maryland.

More than 15 years of aircraft measurements by the UMD, have proven that aloft air coming into Maryland contains ozone concentrations be tween 60 – 100 ppb as the result of sources in the nearby states; including Ohio, West Virginia, Pennsylvania, and Virginia. Each of these
states contributes subs tantially to Maryland's air quality problems. Taubman et al . (2006) compared measured ozone profiles upwind and downwind of the Baltimore area, and determined that when the greatest cluster traj ectory density lay over the Ohio River Valley (~59% of the profiles), transport accounted for 69–82% of the afternoon boundary layer ozone in Maryland. Under stagnant conditions (~27% of the profiles) , transport accounted for 58% of the afternoon boundary laye r ozone in Maryland.

Based on aircraft measurements made during a nine year period (1996-2004) by scientists at the UMD, morning ozone profiles show the highest aloft median ozone concentrations of about 70 ppb at approximately 1,000 meters above the su rface (see Figure 3-2). Once the nocturnal boundary layer breaks down this ozone (plus ozone precursors) are poised to mix to the surface and cause Maryland to experience another ozone exceedance day.

18

### ) Median Ozone (ppb)

Figure 3-2. UMD Aircraft Data - All Morning Ozone Profiles (1996 -2004)

During a flight that took place on July 21, 2011, UM D scientists flew a vertical profile over rural Luray, VA at 11 AM. Aircraft measuremen ts made during this morning flight, showed that approximately 80 ppb of ozone was aloft wa iting to mix down to the surface (see Figure 3- 3). 24-hour back trajectories showed that winds on this day were from the Ohio/West Virginia region.

Ozone concentrations well above the 75 ppb NAAQS have been measured repeatedly over the western (climatologically upwind) boundaries of Maryland. These consistently high concentrations of ozone and ozone precurs ors along with wind patterns (based on back trajectories) make a compelling case that ozone is being trans ported into Maryland from areas outside the State.

190 3,000 6,000 9,000

0 20 40 60 80 100 120 Ozone (ppb)Height (ft)

Figure 3-3. Vertical Profile of Ozone at Luray, VA on July 21, 2011 at 11 AM

MDE started contracting with HU in 2005 to launch ozonesondes during the late night and early morning hours in an effort to measure ozone concentrations in the aloft ozone reservoir and within the nocturnal low level jet (NLLJ).

Figure 3-4 shows 10:30 p.m. and 2:30 a.m. ozonesonde launches on July 12 th and 13 th , 2008 at Beltsville, Maryland. During the 10:30 p.m. la unch the highest ozone concentration of approximately 80 ppb was measured at about 600 m, and during the 2:30 a.m. launch approximately 95 ppb was measured at about 800 m. Both launches captured high ozone concentrations being transported from the sout h to the north within the NLLJ. These high ozone concentrations within the NLLJ are already well above the 75 ppb NAAQS and have been measured repeatedly by ozonesondes launche d from Beltsville, MD. These consistently high concentrations of ozone (and ozone precu rsors) measured within NLLJ (based on ozonesondes and wind profiler measurements) ma ke a compelling case that ozone is being transported into Maryland from areas outside the State.

20Jul y 12 | Jul y 13 ,

Mid Nigh t (EDT )



### (22+ mph for 14+ hours) Î Air T raveled 300+ 10:30 PM

Figure 3-4. Ozone profiles from Ho ward University ozoneso ndes launched at 10:30 p.m

. and
2:30 a.m

. during a NLLJ event on July 12-13, 2008.

MDE started contracting with UMBC scientists in 2002 to make aloft m easurem ents using LIDAR (Lidar Detection And Ranging) technolog y. The LIDAR is used to m easure vertical profiles of atmospheric particles conc entra tions in a tim e serie s . Based on Figure 3-5, there is a high concentration of aerosols aloft in th e early morning hours. At around 10:00 a.m. the nocturnal inversion breaks down and these partic ulates m i x down to the surface and increase the concentrations of ground leve l pollutants. This data support s sim ilar dynam i cs that allow
ozone and o z one precu rs ors to m i x down to the s u rface and com b ined with local po llu tants. 2:30 AM



## N L L J

21Figure 3-5. Particle profile time series from UMBC Lidar in Baltimore, MD on July 28, 2007.

In July 2011, NASA led a major air quality field campaign over Maryland. The project is called DISCOVER-AQ, which stands for Derivi ng Information on Surface conditions from Column and Vertically Resolved Observati ons Relevant to Air Quality. Among the core objectives of this campaign were to measure pollu tant altitude profiles to better correlate those concentrations with surface values, as well as to determine the origins of tropospheric ozone and PM over the Baltimore-Washington area. Preliminary results of the DISCOVER-AQ campaign, exhibited in dozens of presentations at the 2011 American Geophysical Union Fall Meeting, indicate substantial con centrations of ozone and ozone precursors are tr ansported into the Maryland area via the free troposphere and then mix down to the surface.

The success of regional NO
x controls in reducing ozone in Maryland is also well-documented. The implementation of significant local contro ls from 1997 to 2003 in Maryland was able to reduce ozone by about 1 ppb/year. Under the NO
x SIP Call, 75% of the EGU controls were put in place from 2003 to 2007. From 2003 to 2008, Maryland ozone was reduced by 2 ppb/year
— double the rate under local controls alone.

d. The “Meteorologically-Challenged” State Maryland is a meteorologically-challenged state due to its geography, topography and location, as discussed in more detail in the geography se ction. It is located we st of the Ohio River

22Valley, which has a large concentration of power plants. The Chesapeake Bay breeze stops ozone and its precursors from being blown out to sea and instead funnels dirty air along the I95 corridor. The Appalachian M ountains are responsible for bo th the “leeside trough” and “nocturnal low level jet” that speed th e transport of pollution toward Maryland.

e. Significant Contributions from Other States New scientific analysis from the UMD determined the most common transport routes for Maryland ozone exceedance days. Using back traj ectories, this research identified five meteorological regimes associated high ozone days (see Figure 3-6). Th e largest cluster is westerly transport through Ohio and Pennsylva nia. The second largest cluster is northwest transport through Pennsylvania. The third largest cluster is southwest transport from Virginia and West Virginia. Two smaller local clusters were also identifi ed: recirculation and stagnation.

Cluster 1: OH/PA Cluster 2: PA Cluster 3: WV/VA

Figure 3-6. HYSPLIT 48 hr back-trajectory (1000 m)

Only approximately one-third of Maryland’s ai r pollution is from local anthropogenic sources. Approximately half is from interstate transport. This data comes from the EPA’s modeling for the Cross-State Air Pollution Ru le (CSAPR), also known as th e Transport Rule. Table 3-1 summarizes the contributions in ppb (percentage s) of projected 2012 ozone design values for the 15 Maryland monitors included in the sour ce apportionment modeling runs with CAMx. (Note that the four states with the largest contributions match the four states identified in the UMD cluster analysis shown in Figure 3-6.)

23Table 3-1: Contribution to 2012 Ozone Design Values ±

State Maximum Contribution ppb (%) Average Contribution ppb (%) Range (ppb)

Biogenic / BC 21 (29%) 18 (24%) 15 – 21
Maryland 35 (43%) 27 (35%) 17 – 35
Virginia 14 (19%) 9 (12%) 6 – 14
Pennsylvania 8 (11%) 6 (7%) 3 – 8

Ohio 5 (8%) 3 (5%) 1 – 5
West Virginia 5 (7%) 3 (4%) 1 – 5

Other OTR 5 (6%) 2 (3%) 1 – 5

Other Outside OTR 13 (17%) 8 (11%) 4 – 13

± calculations based on final Transport Ru le (aka CSAPR) modeling data from Average and maximum design values by monitoring site for 8-hour ozone, annual PM2.5, and 24-hour PM2.5 for the 2003-2007 base period, the 2012 base case, and the 20 14 base and CSAPR control scenario. (Excel 354 KB) and Contributions of 8-hour ozone, annual PM2.5, and 24-hour PM2.5 from each state to each monitoring site. (Excel 1.38 MB) downloaded from http://www.epa.gov/airtransport/techinfo.html on 8-2-11
While the CSAPR modeling used an 85 ppb standa rd, the release of th e contribution modeling results along with the established 1% significan t contribution threshold allows states like Maryland to identify significant contributors und er the 75 ppb standard. These states, in order of the magnitude of their contribution to Mary land, are: Virginia, Penns ylvania, Ohio, West Virginia, Kentucky, Indiana, Michigan, New Yor k, North Carolina, Tennessee, Illinois, and New Jersey (See Figure 3-6).

Figure 3-6. Significant Contribut ors to Maryland using a 75 ppb Ozone NAAQS, prepared by NESCAUM from EPA CSAPR modeling results.

24The EPA analysis for ozone nonattainment area boundaries and CSAPR bot h have the goal of identifying “linkages” and “significant cont ributions” to an area’s ozone problem. For consistency, the EPA should use the same standa rd as laid out in CSAPR federal regulations, which have gone through the public comment process, should have priority over the interpretation of ozone nonattainment area boundary criteria, which only appear in EPA memoranda to the states. In addition, the CSAP R approach to identifying meteorology-based linkages is consistent with the science of oz one formation and more importantly transport. Therefore, the meteorology factor supports an ozone nonattainment area boundary of a large
multistate area.

f. Resources Castellanos, P., et al. (2011) , Ozone, oxides of nitrogen, and carbon monoxide during pollution events over the eastern United States: An ev aluation of emissions and vertical mixing, Journal of Geophysical Research-Atmospheres , 116. Cooper, O. R., et al. (2010), Increasing springtime ozone mixing ratios in the free troposphere over western North America, Nature , 463(7279), 344-348. Dickerson, R. R., et al. (2007) , Aircraft observations of dus t and pollutants over northeast China: Insight into the meteorological mechanisms of transport , Journal of Geophysical Research-Atmospheres , 112(D24). Gego, E., P. S. Porter, A. Gilliland, and S. T. Rao (2007), Observation-based assessment of the impact of nitrogen oxides emissions reductions on ozone air quality over the eastern United States, Journal of Applied Meteorology and Climatology , 46(7), 994-1008. Hains, J. C. (2007), Measurements and Models of Pollu tants over the Mid Atlantic: A Chemical Climatology , Ph.D. thesis, The University of Maryland, College Park. Hains, J. C., et al. (2008), Origins of chemical pollution derived from Mid-Atlantic aircraft profiles using a clus tering technique, Atmospheric Environment , 42(8), 1727-1741. Hu, X. M., D. C. Doughty, K. J. Sanchez, E. Joseph, and J. D. Fuentes (2012), Ozone variability in the atmospheric boundary layer in Maryland and its implic ations for vertical transport model, Atmospheric Environment , 46, 354-364. Liu, S. C., et al. (1987), Ozone production in the rural troposphe re and the implications for regional and global oz one distributions, Journal of Geophysical Research-Atmospheres

, 92(4), 4191-4207. Logan, J. A. (1989), Ozone in rural areas of the United States, Journal of Geophysical Research-Atmospheres , 94(6), 8511-8532. McDonald-Buller, E. C., et al. (2011), Establishing policy relevant background (PRB) ozone concentrations in the United States, Environmental Science & Technology , 45(22), 9484- 9497. Moy, L. A., R. R. Dickerson, and W. F. Ryan (1994), Relationship between back trajectories and tropospheric trace gas concen trations in rural Virginia, Atmospheric Environment

, 28(17), 2789-2800. NASA, DISCOVER-AQ, Preliminary results can be found at the AGU websites: http://m.coreapps.com/agu2011/events/47861d67ddbb4c56c416d7f61f5dca2a and at the NASA website: http://acmg.seas.harvar d.edu/aqast/index.html

. Ryan, W. F., et al. (1998), Polluta nt transport during a regional O 3 episode in the Mid-Atlantic
states, Journal of the Air & Wast e Management Association , 48(9), 786-797.

25Taubman, B. F., et al. (2006), Ai rcraft vertical profiles of tr ace gas and aerosol pollution over the Mid-Atlantic United States: Statis tics and meteorological cluster analysis, Journal of Geophysical Research-Atmospheres , 111(D10). Yorks, J. E., A. M. Thompson, E. Joseph, and S. K. Miller (2009), The variability of free tropospheric ozone over Beltsville, Maryla nd (39N, 77W) in the summers 2004-2007, Atmospheric Environment , 43(11), 1827-1838. Zhang, J., and S. T. Rao (1999), The role of ve rtical mixing in the temporal evolution of ground-level ozone concentrations, Journal of Applied Meteorology , 38, 1674-1691.



### Geography/topography (mountain ranges or other air basin boundaries)

The next factor is geography and topography including mountain ranges or other air basin
boundaries.

a. No Intrastate Barriers MDE agrees with the EPA conclusion that th e Washington-Baltimore-Northern Virginia CSA generally does not have any ba rriers appreciably limiting air po llution within its air shed. The Appalachian Mountains are a barrie r to surface transport but not to aloft transport of ozone and

ozone precursors.

b. Chesapeake Bay Breeze There is an important air ba sin boundary not addressed by the EPA analysis: the Chesapeake Bay. The “bay breeze” plays a significant role in preventing pollution from blowing out to sea and channeling it back toward Washington, DC, and Baltimore.

As show in Figure 4-1, the air over the Bay remains cooler during the day than the land, creating a breeze that flows from the east. As ozone is usually blown in from the west, the breeze creates a “wall” that allows the pollution to build up on the west side of the Bay, where Washington, DC, and Baltimore (and the Edge wood monitor) are located (Landry 2011). This barrier also channels pollution in a northeas t direction, up toward Pe nnsylvania, New Jersey, and New York.

Figure 4-1: Chesapeake Bay Breeze as an Air Basin Barrier, from MDE

26c. Leeside Trough The position of the Appalachian Mountain s enables formation of a meteorological phenomenon called a “leeside trough.” According to the American Meteorological Association Glossary (2010), a leeside trough is “a pressure trough formed on th e lee side [opposite the wind] of a mountain range in situations where the wind is blowing with a substantial component across the mountain ri dge; often seen on United Stat es weather maps east of the Rocky Mountains, and sometimes east of the Appal achians." This shift in pressure along the trough (the orange dashed line in Figure 4-2) results in westerly to northwesterly flow on the
left side and southerl y flow on the right side. Since th e leeside trough usually develops over Maryland, this phenomenon results in pollutants fr om the Ohio River Valley and Western PA veering (or turning northward) into Maryland an d at the same time allows ozone and ozone precursors to be transported from Virgin ia and North Carolina into Maryland too.

Figure 4-2. August 10, 2010 12z Surface Analysis from the Hydrometeorological Prediction Center (HPC)

On August 10, 2010 a lee side trough formed ove r Maryland and the result was an ozone exceedance day, which included pockets of unhealthy air quality (refer to Figure 4-3).

27Figure 4-3. August 10, 2010 EPA AQI Map

d. Nocturnal Low Level Jet Another meteorological phenomenon that resu lts from the location of the Appalachian Mountains to the west and the A tlantic Ocean to the east is the nocturnal low level jet (NLLJ). The NNLJ is a fast moving stream of air that is typically observed be tween the Appalachian Mountains and the Atlantic Ocean during the late night and early morning hours. This fast moving stream of air can reach sp eeds of 40 mph and stretches fr om NC to MD to NJ to MA (refer to Figure 4-4).

In an effort to measure ozone concentrations in the NLLJ, MDE started contracting with the scientists at HU in 2005 to launch ozonesondes during the late night and early morning hours (see the factor 3 Meteorology se ction). Based on these ozonesonde measurements, ozone in excess of 90 ppb has been measured on several o ccasions within the NLLJ (refer to Figure 4- 5).

28Figure 4-4. Extent of the Nocturnal Low Level Jet 

### W i n d S p e e d a n d W i n d D i r e c t i o n

B e l t s v i l l e 

### p 

### August 25, 2008

Satellite Ima

Figure 4-5. Ozone Concentrations W ith in the Nocturnal L o w Level Jet , M D N e w B r u n s w i c k , N J S t o w , M A g e

R a l e i g h , N C

8 PM 11 PM 2 A M 5 A M 8 A M 11 A M NLLJ

So u r ce s: NASA, NOAA



### 2:30 AM

29e. True Air Shed Size? The “air shed” that is relevant to the ozone nonattainment area boundary is the same as the “air shed” for the Chesapeake Bay, since both seek to delineate sources of nitrogen oxides (NO
x ) that contribute to federally -regulated pollution (Dennis 1997).

Figure 4-6: States in the Chesapeake Bay Air Shed, from Chesapeake Bay Foundation, http://www.cbf.org/page.aspx?pid=577 , retrieved 2/1/12

As shown in Figure 4-6, the Chesapeake Bay ai r shed includes Maryland, Delaware, Virginia, Pennsylvania, West Virginia, North Carolina, Ohio, most of New Yor k, New Jersey, Kentucky and South Carolina, and parts of Indiana, Te nnessee, Michigan, and Vermont. Therefore, the geography factor supports a large mu ltistate nonattainment area boundary.

d. Resources Civerolo, K. L., H. T. Mao, and S. T. Rao ( 2003), The airshed for ozone and fine particulate pollution in the eastern United States , Pure Appl. Geophys ., 160(1-2), 81-105. Dennis R.L., 1997. Using the regional acid deposition model to determine the nitrogen deposition airshed of the Chesapeake Bay watershed. In: Baker, J., ed., Atmospheric

30Deposition to the Great Lakes and Coastal Wate rs. Society of Environmental Toxicology and Chemistry : Pensacola, FL; pp. 393-413. Fischer, E. V., R. W. Talbot , J. E. Dibb, J. L. Moody, and G. L. Murray (2004), Summertime ozone at Mount Washington: Meteorological cont rols at the highest peak in the northeast, Journal of Geophysical Research-Atmospheres , 109(D24). Godowitch, J.M., Gilliam, R.C., and Rao, T.S. (2011), Diagnostic evaluation of ozone production and horizontal transport in a regional photoche mical air quality modeling system, Atmospheric Environment , 45, 3977–3987 [NLLJ]. Lai, T.-L., Talbot, R., and Mao, H. (2012), An investigation of two highest ozone episodes during the last decade in New England, Atmospheres , 3, 59–86 [Leeside Troughs and NLLJ] Landry, L. (2011), The influence of the Chesapeake Bay breeze on Maryland air quality, MARAMA Data Analysis Workshop , College Park, MD, January 20–21. Kleinman, L. I., et al. (2004), An ozone ep isode in the Philadelphia metropolitan area, Journal of Geophysical Research-Atmospheres , 109(D20). Loughner, C. P., D. J. Allen, K. E. Pickering, D. L. Zhang, Y. X. Shou, and R. R. Dickerson (2011), Impact of fair-weather cumulus clouds and the Chesapeake Bay breeze on pollutant transport and transformation, Atmospheric Environment , 45(24), 4060-4072. Yorks, J. E., A. M. Thompson, E. Joseph, and S. K. Miller (2009), The variability of free tropospheric ozone over Beltsville, Maryla nd (39N, 77W) in the summers 2004-2007, Atmospheric Environment , 43(11), 1827-1838 [NLLJ] Zhang, D.-L., S. Zhang, and S. J. Weaver (2006), Low-level jets over th e Mid-Atlantic states: Warm-season climatology and a case study, Journal of Applied Meteorology and Climatology , 45, 194–209



### Jurisdictional boundaries The proposed large nonattainment area has cl early defined legal boundaries within the nonattainment area. The air quality planning f unctions, transportation planning functions and enforcement functions can work as described earlier for the Philade lphia region, with the additional of more sub regions.

31

## APPENDIX B 5 (9) – FACTOR ANAL YSIS FOR BALTIMOREWASHINGTON CSA NONATTAINMENT AREA

Since the 1990 Clean Air Act Amendments (CAAA) passed, EPA has used a 9 factor analysis to determine the boundaries of nonattainment areas (c urrently condensed into 5 factors). In the early 1990s this methodology supported the CAAA enlargement of nonattainment areas to have boundaries coincident with the boundaries of consolidated metropolitan statistical areas. It was also in keeping with the theory at that time that transport was short range, mostly from large metropolitan area to large metropolitan ar ea. This theory formed the basis for creating the Northeast Ozone Transport Region.

The 1990 Census was the first census to combine the Baltimore and Washington metropolitan statistical areas into a consolidated metropolitan statistical area. The publication of the census findings was too late to create a combined nonattainment area for Baltimore and Washington, DC under the one hour ozone standard. As designations progressed for the 1997 eight hour ozone standard, both Baltimore and Washington, DC were designated and classified as moderate subjecting them to the same require ments. EPA’s proposed designations for the 2008 eight hour ozone standard classify Baltimore as moderate and Washington, DC as marginal, creating a significant disparity in the requirements each area must meet.

MDE has investigated the Edge wood monitor responsible for the moderate classification proposed for the Baltimore nonattainment area. The monitor is directly influenced by emissions from the Washington, DC area. We be lieve that this influence will increase if the Washington region is classified as marginal a nd maintained as a sepa rate nonattainment area from the Baltimore region. The two metropolitan areas are separated by less than 30 miles from center to center. We believe that EPA should designate the Combined Statistical Area (CSA) as one nonattainment area and classify the area as appropriate. Th e following analysis supports this recommendation. The area would probably retain the sub regional boundaries now in place but the area as a whol e would be classified uniformly.



### Summary of the 5-Factor Analysis

1. Air Quality Data EPA carefully examines the air quality data for ea ch county in the combined statistical area to determine whether the county contains a violatin g monitor. If it does EPA looks at contiguous
counties for cause or contributi on. In proposing to separate Baltimore and Washington, DC, EPA did not look at the CSA as a whole. Throughout almost th e entire CSA, monitoring data is relatively uniform with the exception of fringe outer counti es and the Edgewood monitor. EPA actually comments that the Anne Arundel Count y monitor tracks well with values at the Virginia design value monitor. This is because the overall air quality of the CSA is fairly uniform and emissions from the region as a whole generate ozone uniformly throughout the region. This is an indication that the Baltimore region is affected strongly and mostly by sources to the south and west, which includes the Washington, DC area. EPA states in analyses from other states that this is typical of the northeastern United States, since most of peak ozone design values

32are found north and east of the centers of major urban areas. We believe this uniformity demonstrates that the two regions should be de signated as one nonattainment area. In support of this belief, Maryland has micro scale modeli ng that shows the influence of the Chesapeake Bay and the bay breeze effect on the transpor ted emissions from the Washington, DC region which helps explain the abnormally high readings at the E dgewood monitor.

2. Emissions and Emissions-Related Data Emissions throughout the CSA are fairly uniform . EPA has used 2008 emissions data which excludes the reductions from the Maryland Hea lthy Air Act. Most of the counties with exceptionally high NO
x emissions contain power plants which supply most of the power for the Washington DC area. If EPA used current da ta that captures the re ductions made by the Healthy Air Act the Maryland NO
x data would be lower as shown in Table 8 revised from EPA’s analysis. Additionall y, three quarters of the 495 Belt way which serves the CSA lies within Maryland. The NO
x emissions from traffic on this portion of the beltway are attributed to Maryland even though Virginia commuters regularly utilize this highway. Table 8 shows
that mobile emissions are the dominant factor in the Washington region. Growth factors in Virginia far outpace growth factors for count ies in Maryland implying additional non-point source emissions in the region.

3. Meteorology Through research, MDE has found the existence of a localized phenomena referred to as the Chesapeake Bay breeze. The Chesapeake Bay br eeze is caused by the sharp gradient between land and water temperatures which causes the air over the warmer land to rise and be replaced at the surface by cooler air from atop the Bay wate rs. This sharp gradient effectively creates a
microclimate akin to a mini-cold front that inhi bits pollution transport across the Chesapeake Bay, and instead transports pollution towards th e western side of the bay where the Edgewood monitor is located. Scientists from the Univ ersity of Maryland College Park (UMD) have performed high resolution (0.5 km do main) WRF (meteorological) and CMAQ (photochemical) modeling that illustrates how ea rly morning stagnation over the Chesapeake Bay allows high pollution concentrations at the bay breeze convergen ce zone to buildup and then be lofted and transported downwind. Th e high resolution photochemical modeling shows that pollution transported from the Baltimor e and Washington, DC regions is directed northwestward towards the Edgewood monito r. This high resolution CMAQ modeling generates ozone concentrations that are closer to the observed concentrations.

4. Geography The topography and geography of the Baltimore and Washington, DC regions are similar. As stated in the meteorology section, the Chesapeake Bay is a barrier to the east of both regions.
Monitors on the eastern shore of Maryland are attaining the sta ndard in the absence of other urban areas. However, the western shore of the Bay is influenced by the Chesapeake Bay breeze which effectively creates a microclimate akin to a mini-cold front that inhibits pollution transport across the Chesapeake Bay, and instead transports pollution towards the western side of the bay where the Edgewood monitor is loca ted and concentrates emissions along its edge.

5. Jurisdictional Boundaries The CSA has county boundaries even though it cro sses state lines. It would have within it three or more functional sub regions currently performing both air quali ty and transportation planning. While it may be possible to exclude so me of the outer ring co unties, the fact that

33these counties are included as part of the CS A indicates their forming ties to the core urban

area.



### Air quality data EPA reviews the design values for ozone monito rs to locate violating monitors. EPA then
establishes nonattainment area s around those monitors expand ing outward and geographically ending the nonattainment area when monitors measuring attainment are found. The inclusion of the Baltimore and Washington, DC regions in a single nonattainment area is consistent with this technique.

Plotting the design values for each county on a map shows that most of the Baltimore and Washington, DC region have similar design valu es with few exceptions. The exceptions are Baltimore City, one of the two monitors in Harford County, and the outer ring counties in Virginia and Maryland. It seems rather ar bitrary to separate the two areas based on Metropolitan Statistical Area (MSA) boundaries.

EPA actually comments that the Anne Arundel Count y monitor tracks well with values at the Virginia design value monitor. This is because the overall air quality of the CSA is fairly uniform and emissions from the region as a whole generate ozone uniformly throughout the region. This is an indication that the Baltimore region is affected strongly and mostly by sources to the south and west, which includes the Washington DC area. EPA states in analyses from other states that this is typical of the northeastern United States, since most of the peak ozone design values are found north and east of the centers of major urban areas. We believe this uniformity demonstrates that the two regions should be designated as one nonattainment area.

In support of this belief, Maryland has micro s cale modeling that shows the influence of the Chesapeake Bay on the transported emissions fr om the Washington, DC region and explains the abnormally high readings at the Edgewood m onitor (further discu ssed in the meteorology section). The other monitor in Harford County tracks well with other design values in the region, most of which are within a couple percent of the standard.

We have empirical evidence of emissions tran sported by the nocturnal low level jet (NLLJ). This is a strong southwest wind along eastern side of the Appalachian Mount ains that runs very close to the ground. It begins at sundown and can last until dawn. It can start as far south as North Carolina and can reach as far north as New Jersey, Massachusetts, and Connecticut. Given an average speed of 30 m ph, a NLLJ that runs for 7 hours carries gases and particulates 210 miles. Data collected simultaneously from wind profilers and ozonesondes has revealed that ozone is transported via the low level je t. Lidar data reveals similar transport for particulate matter.



### Emissions and emissions-related data Once an independent factor, EPA now combines emissions related data with the emissions
factor. EPA interprets emissions-related data to include actual and estimated emissions of VOC
and NO
x from sources, including data available in th e latest National Emissions Inventory, the latest information and trends for Vehicle Miles Traveled (VMT) and commuting, and population characteristics and trends of the area (growth factors). Population, VMT and commuting

34patterns, and growth factors were once indepe ndent factors. Traffic and commuting patterns
indicate the location of non point source emissions.

Transport becomes central to attainment in more and more states with every lowering of the NAAQS. In Maryland’s case, this includes transport from nearby areas, such as the other half of the CSA. Estimates of the time needed to form ozone correspond with the time it takes emissions from the Washington, DC region to travel over the Baltimore region.

Emissions throughout the CSA are fairly uniform . In making its propo sed designations, EPA has used 2008 emissions data, which excludes the reductions from the Maryland Healthy Air Act. Most of Maryland’s counties with exceptionally high NO
x emissions contain power plants. If EPA used current da ta that captures the reductions made by the Healthy Air Act the Maryland NO
x data would be lower as shown in the revision to Table 8 from EPA’s 5-factor analysis for Maryland. Maryland ’s actual emission rates for th e Baltimore region versus its real world monitoring data support the conclusion that the Baltimore region is significantly impacted from transported emissions, includi ng those from the Washington, DC region.

Despite the substantial reductions in point s ource emissions from the Healthy Air Act, NO
x emissions remain high for the Maryland counties in the Washington CSA. This is because emissions in the Washington metropolitan area ar e predominantly from mobile sources. Three quarters of the 495 Beltway which serves the CSA lies within Maryland. The NO
x emissions from traffic on this portion of the beltway ar e attributed to Maryla nd even though Virginia commuters regularly utilize this highway. Grow th factors in Virginia far outpace growth factors for counties in Maryland implying growth in additional non-point source emissions in the region.

EPA’s Table 8 7 is reproduced here, reflecting the reduc tions produced by the Healthy Air Act. These reductions help equalize emissions in between the Baltimore and Washington DC regions. Power plants in Maryland are the major suppliers of electricity to the Baltimore and Washington DC regions. Tabl e 8 shows emissions of NO
x and VOC given in tons per year (tpy) for violating and potentially contributing counties in the current Baltimore MD and Washington DC-MD-VA nonattainment areas and other portions of the WashingtonBaltimore-NV CSA.

Table 8.
Total 2008 NO
x and VOC Emissions with 2012 Healthy Air Act Caps Applied

County/City State Recommended
Nonattainment? NO
x (tpy) VOC (tpy)

Current Baltimore MD Nonattainment Area:

Anne Arundel County Co., MD Yes 22,110 14,423 Baltimore City, MD Yes 18,621 11,397

7 MARYLAND Area Designations for the 2008 Ozone Na tional Ambient Air Quality Standards, pp 33-35.

35Table 8.
Total 2008 NO
x and VOC Emissions with 2012 Healthy Air Act Caps Applied

County/City State Recommended
Nonattainment? NO
x (tpy) VOC (tpy)

Carroll County, MD Yes 6,617 3,948 Harford County, MD Yes 5,854 6,396 Howard County, MD Yes 9,219 7,848 Baltimore County, MD Yes 25,736 16,807

Baltimore Subtotal: 88,157 60,819

County/City State Recommended
Nonattainment? NO
x (tpy) VOC (tpy)

Current Washington DC-MD-VA Nonattainment Area:

District of Columbia, DC Yes 11,332 11,362 Calvert County, MD Yes 2,797 2,406 Charles County, MD Yes 5,823 3,939 Frederick County, MD Yes 9,389 6,460 Montgomery County, MD Yes 18,415 20,426 Prince George's County, MD Yes 19,793 18,882 Arlington County, VA Yes 5,264 4,329 Fairfax County, VA Yes 21,403 25,603 Loudoun County, VA Yes 6,948 7,331 Prince William County, VA Yes 7,698 8,603 Alexandria City, VA Yes 3,349 2,625 Fairfax City, VA Yes 326 794 Falls Church City, VA Yes 138 324 Manassas City, VA Yes 553 1,020 Manassas Park City, VA Yes 92 285 Washington DC-MD-VA Subtotal: 113,321 114,389

Fredericksburg, VA Area: Spotsylvania County, VA No 3,539 4,226 Stafford County, VA No 3,377 3,516 Fredericksburg City, VA No 859 1,007 Fredericksburg, VA Subtotal: 7,775 8,749

Frederick County, VA Area:

36Table 8.
Total 2008 NO
x and VOC Emissions with 2012 Healthy Air Act Caps Applied

County/City State Recommended
Nonattainment? NO
x (tpy) VOC (tpy)

Frederick County, VA No 2,838 4,714 Winchester City, VA No 508 1,006 Frederick Co., VA Area Subtotal: 3,346 5,720

Other counties: Queen Anne's County, MD No 2,725 2,402 St. Mary's County, MD No 3,475 4,038 Clarke County, VA No 941 949 Culpeper County, VA No 1,726 2,109 Fauquier County, VA No 3,383 3,389 Warren County, VA No 1,463 1,773 Hampshire County, WV No 734 2,078 Jefferson County, WV No 1,566 1,481

All other counties subtotal: 16,013 18,219

CSA Total: 228,612 207,896

Growth rates are not uniform throughout the CSA. Growth rates indicate growth in emissions including growth in VMT, growth in area source s, growth in point sources, and growth in nonroad sources. The higher growth rates in some Virginia counties will result in additional emissions impacts to the Baltimore region due to tr ansport. The impacts of this growth would be shared if EPA designated th e CSA as one nonattainment area.

Maryland has taken numerous steps to both reduce emissions through technological measures and to encourage reductions in VMT. We are currently waiting to implement our Clean Cars program and are implementing aspirational conform ity goals. These are difficult steps to take when they provide greater air quality bene fits to downwind states than to Maryland, particularly where similar programs are not implemented in surrounding states.



### Meteorology The next factor, meteorology, includes weather and transport patterns. The EPA uses 30-year average summer surface-level wind directi ons to help identify ozone nonattainment boundaries.

a. Local Transport MDE agrees with the EPA finding that meteorol ogical data does not provide a basis for separating the Baltimore and Washington, DC nona ttainment areas. In fact, “[s]everal Maryland counties in the current Washingt on DC-MD-VA nonattainment area are most

37frequently upwind of and most proximate to a violating monitor in the current Baltimore
nonattainment area. 8 ”

In addition, MDE has found the existence of a localized phenomena referred to as the Chesapeake Bay breeze and based on research conducted by the University of Maryland College Park (UMD), have determined that the bay breeze acts to adversely affect the Edgewood monitor causing it to repo rt ozone concentrations that are consistently a bit higher
than other area ozone monitors.

The Chesapeake Bay breeze is caused by the sharp gradient between land and water temperatures which causes the air over the warmer land to rise and be replaced at the surface by cooler air from atop the Bay waters. This sh arp gradient effectively creates a microclimate akin to a mini-cold front that inhibits po llution transport across the Chesapeake Bay, and instead transports pollution towards the wester n side of the bay where the Edgewood monitor is located. Refer to Figure 3-2 for a schematic of the bay breeze.

Figure 3-2: Chesapeake Bay Breeze as an Air Basin Barrier, from MDE

Scientists from the UMD have performe d high resolution (0.5 km domain) WRF (meteorological) and CMAQ (photochemical) mode ling in an effort to learn how the bay breeze dynamics work and if pollution from the Washington area is transported towards the Edgewood monitor. This high resolution mete orological modeling shows westerly winds transport ozone and ozone precursors from the Washington region to over the bay starting in the early morning hours (7 AM). Refer to Figure 3-3 for these meteorological modeling results. Later in the morning, at around 9 AM (EST) meteorological modeling shows winds over the bay become northerly and sta gnation in the northern end of the Chesapeake Bay causes pollutants to accumulate. Refer to Figure 3-4 for these meteorological modeling results. High resolution CMAQ modeling illustra tes how early morning stagnation over the Chesapeake Bay

8 MARYLAND Area Designations for the 2008 Ozone National Ambient Air Quality Standards, p.59.

38allows high pollution concentrations at the ba y breeze convergence zone to buildup and then be lofted and transported downwind towards the E dgewood monitor. Base d on the comparison of
monitored data and modeled data it can be seen that this high resolution CMAQ modeling generates ozone concentrations th at are closer to the observed concentrations. Refer to Figure 3-5 for the CMAQ modeling results.

Figure 3-3 WRF-UCM Temperature and 10-me ter Wind Speed at 7 AM on July 9, 2007 (Loughner, High Resolution WRF-UCM a nd CMAQ Modeling, UMD-MDE RAMMPP Quarterly Meeting, April 25, 2011)

39Figure 3-4 WRF-UCM Temperature and 10-me ter Wind Speed at 9 AM on July 9, 2007 (Loughner, High Resolution WRF-UCM a nd CMAQ Modeling, UMD-MDE RAMMPP Quarterly Meeting, April 25, 2011)

40Figure 3-5 Ozone Concentrations at 2 PM on July 9, 2007 (Loughner, High Resolution WRFUCM and CMAQ Modeling, UMD-MDE RAMMPP Quarterly Meeting, April 25, 2011)

Based on the high resolution modeling completed by the UMD and that the largest source of
NO
x emissions (post Maryland’s Healthy Air Ac t (HAA)) in the region are from mobile sources; where the split between the Baltimore and Washington areas is approximately 40%

41a nd 60%, respectively. It can be concluded, th at Edgewood always having a bit higher ozone
linke d to Washington area mobile NO
x emissions.

. rs based on three- dimensional wind fields provide a more realistic presentation of the origins of air during oz one exceedance days (see, e.g., Hains et al., 2008 06).

MBC) and others have used aircraft, ozones ondes, and remote sensing techniques to show

in
these

of the afternoon boundary layer ozone in Maryland. Under stagnant conditions (~27% of the profiles) , transport accounted for 58%

ately 80 ppb of ozone was aloft wa iting to mix down to the surface (see Figure 3- ). 24-hour back trajectories showed that winds on this day were from the Ohio/West Virginia

er the

one and ozone precurs ors along with wind patterns (based on back ajectories) make a compelling case that ozone is being trans ported into Maryland from areas outside the State. concentration is directly

b. Regional Transport However, climatological surface wind direction only tells part of the meteorological story. Surface wind roses do not represent the three-dime nsional flow of air in the atmosphere. Transport patterns based solely on surface wind speed and direction ignores aloft winds and regular vertical mixing such as occurs in the da ily cycle of the planetar y boundary layer (PBL) Objective, hierarchical cluste

re and Taubman et al., 20

c. Scientific Evidence There is an extensive body of scientific findings proving th at regional transport plays a significant role in urban high ozone episode s in Maryland. During the summer ozone season, scientists from UMD, Howard University ( HU), University of Maryland Baltimore County (U that both ozone and its precursors are transp orted from nearby upwind states into Maryland.

More than 15 years of aircraft measurements by the UMD, have proven that aloft air coming into Maryland contains ozone concentrations be tween 60 – 100 ppb as the result of sources the nearby states; including Ohio, West Virginia, Pennsylvania, and Virginia. Each of
states contributes subs tantially to Maryland's air quality problems. Taubman et al . (2006) compared measured ozone profiles upwind and downwind of the Baltimore area, and determined that when the greatest cluster traj ectory density lay over the Ohio River Valley (~59% of the profiles), transport accounted for 69–82%

of the afternoon boundary laye r ozone in Maryland.

During a flight that took place on July 21, 2011, UM D scientists flew a vertical profile over rural Luray, VA at 11 AM. Aircraft measuremen ts made during this morning flight, showed that approxim
6 region.

Ozone concentrations well above the 75 ppb NAAQS have been measured repeatedly ov western (climatologically upwind) boundaries of Maryland. These consistently high
concentrations of oz

tr

420 3,000 6,000 9,000

0 20 40 60 80 100 120 Ozone (ppb)Height (ft)

Figure 3-6. Vertical Profile of Ozone at Luray, VA on July 21, 2011 at 11 AM

MDE started contracting with HU in 2005 to launch ozonesondes during the late night and early morning hours in an effort to measure ozone concentrations in the aloft ozone reservoir and within the nocturnal low level jet (NLLJ).

Figure 3-7 shows 10:30 p.m. and 2:30 a.m. ozonesonde launches on July 12 th and 13 th , 2008 at Beltsville, Maryland. During the 10:30 p.m. la unch the highest ozone concentration of approximately 80 ppb was measured at about 600 m, and during the 2:30 a.m. launch approximately 95 ppb was measured at about 800 m. Both launches captured high ozone concentrations being transported from the sout h to the north within the NLLJ. These high ozone concentrations within the NLLJ are already well above the 75 ppb NAAQS and have been measured repeatedly by ozonesondes launche d from Beltsville, MD. These consistently high concentrations of ozone (and ozone precu rsors) measured within NLLJ (based on ozonesondes and wind profiler measurements) ma ke a compelling case that ozone is being transported into Maryland from areas outside the State.

43Jul y 12 | Jul y 13 ,

Mid Nigh t (EDT )



### (22+ mph for 14+ hours) Î Air T raveled 300+

Figure 3-7. Ozone profiles from Ho ward University ozoneso ndes launched at 10:30 p.m

. and
2:30 a.m

. during a NLLJ event on July 12-13, 2008.

In July 2011, NASA led a m a jor air quality fiel d cam p aign over Maryland. The project is called DISCOVER-AQ, which stands for Derivi ng Inform ation on Surface conditions from Colum n and Vertically Resolved Observati ons Relevant to Air Quality. Am ong the core objectives of this cam paign were to m easure pollu tan t altitud e prof iles to better correlate tho s e concentratio ns with surf ace valu es, as well as to determ ine th e orig ins of tropospheric ozone and PM over the Baltim ore-W a shington area. Prelim inary results of th e DISCOVER-AQ

cam paign, exhibited in dozens of presentations at the 2011 Am erican Geophysical Union Fall Meeting, indicate substantial con centrations of ozone and ozone precursors are tr ansported into the Mary lan d area v i a th e free tropo s phere and th en m i x down to the su rface.

The success of regional NO
x controls in reducing ozone in Maryland is also well-docum ented.
The im ple m entation of significant local contro ls from 1997 to 2003 in Maryland was able to reduce ozone by about 1 ppb/year. U nder the NO
x SIP Call, 75% of the EGU controls were put in place from 2003 to 2007. From 2003 to 2008, Maryland ozone was reduced by 2 ppb/year
— double the rate under local controls alone.

d. The “Meteorologically-Challeng ed” State Maryland is a m e teorologically-challenged state due to its geography, topography and location,
as discussed in m o re detail in the geography se ction. It is located we st of the Ohio River Valley, which has a large concentration of pow er plants. The Chesapeake Bay breeze s t ops ozone and its precursors from being blown out to sea and instead funnels dirty air along the I10:30 PM



## N L L J 2:30 AM

4495 corridor. The Appalachian M ountains are responsible for both the “leeside trough” and “nocturnal low level jet” that speed th e transport of pollution toward Maryland.

e. Significant Contributions from Other States New scientific analysis from the UMD determined the most common transport routes for Maryland ozone exceedance days. Using back traj ectories, this research identified five meteorological regimes associated high ozone days (see Figure 3-8). Th e largest cluster is westerly transport through Ohio and Pennsylva nia. The second largest cluster is northwest transport through Pennsylvania. The third largest cluster is southwest transport from Virginia and West Virginia. Two smaller local clusters were also identifi ed: recirculation and stagnation.

Cluster 1: OH/PA Cluster 2: PA Cluster 3: WV/VA

Figure 3-8. HYSPLIT 48 hr back-trajectory (1000 m)

Only approximately one-third of Maryland’s ai r pollution is from local anthropogenic sources. Approximately half is from interstate transport. This data comes from the EPA’s modeling for the Cross-State Air Pollution Ru le (CSAPR), also known as th e Transport Rule. Table 3-1 summarizes the contributions in ppb (percentage s) of projected 2012 ozone design values for the 15 Maryland monitors included in the sour ce apportionment modeling runs with CAMx. (Note that the four states with the largest contributions match the four states identified in the UMD cluster analysis shown in Figure 3-8.)

45Table 3-1: Contribution to 2012 Ozone Design Values ±

State Maximum Contribution ppb (%) Average Contribution ppb (%) Range (ppb)

Biogenic / BC 21 (29%) 18 (24%) 15 – 21
Maryland 35 (43%) 27 (35%) 17 – 35
Virginia 14 (19%) 9 (12%) 6 – 14
Pennsylvania 8 (11%) 6 (7%) 3 – 8

Ohio 5 (8%) 3 (5%) 1 – 5
West Virginia 5 (7%) 3 (4%) 1 – 5

Other OTR 5 (6%) 2 (3%) 1 – 5

Other Outside OTR 13 (17%) 8 (11%) 4 – 13

± calculations based on final Transport Ru le (aka CSAPR) modeling data from Average and maximum design values by monitoring site for 8-hour ozone, annual PM2.5, and 24-hour PM2.5 for the 2003-2007 base period, the 2012 base case, and the 20 14 base and CSAPR control scenario. (Excel 354 KB) and Contributions of 8-hour ozone, annual PM2.5, and 24-hour PM2.5 from each state to each monitoring site. (Excel 1.38 MB) downloaded from http://www.epa.gov/airtransport/techinfo.html on 8-2-11

f. Resources Castellanos, P., et al. (2011) , Ozone, oxides of nitrogen, and carbon monoxide during pollution events over the eastern United States: An ev aluation of emissions and vertical mixing, Journal of Geophysical Research-Atmospheres , 116. Cooper, O. R., et al. (2010), Increasing springtime ozone mixing ratios in the free troposphere over western North America, Nature , 463(7279), 344-348. Dickerson, R. R., et al. (2007) , Aircraft observations of dus t and pollutants over northeast China: Insight into the meteorological mechanisms of transport , Journal of Geophysical Research-Atmospheres , 112(D24). Gego, E., P. S. Porter, A. Gilliland, and S. T. Rao (2007), Observation-based assessment of the impact of nitrogen oxides emissions reductions on ozone air quality over the eastern United States, Journal of Applied Meteorology and Climatology , 46(7), 994-1008. Hains, J. C. (2007), Measurements and Models of Pollu tants over the Mid Atlantic: A Chemical Climatology , Ph.D. thesis, The University of Maryland, College Park. Hains, J. C., et al. (2008), Origins of chemical pollution derived from Mid-Atlantic aircraft profiles using a clus tering technique, Atmospheric Environment , 42(8), 1727-1741. Hu, X. M., D. C. Doughty, K. J. Sanchez, E. Joseph, and J. D. Fuentes (2012), Ozone variability in the atmospheric boundary layer in Maryland and its implic ations for vertical transport model, Atmospheric Environment , 46, 354-364. Liu, S. C., et al. (1987), Ozone production in the rural troposphe re and the implications for regional and global oz one distributions, Journal of Geophysical Research-Atmospheres

, 92(4), 4191-4207. Logan, J. A. (1989), Ozone in rural areas of the United States, Journal of Geophysical Research-Atmospheres , 94(6), 8511-8532.

46McDonald-Buller, E. C., et al. (2011), Establishing policy relevant background (PRB) ozone concentrations in the United States, Environmental Science & Technology , 45(22), 9484- 9497. Moy, L. A., R. R. Dickerson, and W. F. Ryan (1994), Relationship between back trajectories and tropospheric trace gas concen trations in rural Virginia, Atmospheric Environment

, 28(17), 2789-2800. NASA, DISCOVER-AQ, Preliminary results can be found at the AGU websites: http://m.coreapps.com/agu2011/events/47861d67ddbb4c56c416d7f61f5dca2a and at the NASA website: http://acmg.seas.harvar d.edu/aqast/index.html

. Ryan, W. F., et al. (1998), Polluta nt transport during a regional O 3 episode in the Mid-Atlantic
states, Journal of the Air & Wast e Management Association , 48(9), 786-797. Taubman, B. F., et al. (2006), Ai rcraft vertical profiles of tr ace gas and aerosol pollution over the Mid-Atlantic United States: Statis tics and meteorological cluster analysis, Journal of Geophysical Research-Atmospheres , 111(D10). Yorks, J. E., A. M. Thompson, E. Joseph, and S. K. Miller (2009), The variability of free tropospheric ozone over Beltsville, Maryla nd (39N, 77W) in the summers 2004-2007, Atmospheric Environment , 43(11), 1827-1838. Zhang, J., and S. T. Rao (1999), The role of ve rtical mixing in the temporal evolution of ground-level ozone concentrations, Journal of Applied Meteorology , 38, 1674-1691.



### Geography/topography (mountain ranges or other air basin boundaries) The next factor is geography and topography, including mountain range s or other air basin
boundaries.

a. No Intrastate Barriers MDE agrees with the EPA conclusion that th e Washington-Baltimore-Northern Virginia CSA generally does not have any ba rriers appreciably limiting air po llution within its air shed. The Appalachian Mountains are a barrie r to surface transport but not to aloft transport of ozone and

ozone precursors.

b. Chesapeake Bay Breeze As discussed previously in the meteorology se ction, the Chesapeake Bay is an important air basin boundary not addressed by the EPA analysis. The Chesapeake Bay “breeze” plays a significant role in preventing pollution from blow ing out to sea and channeling it back toward the Baltimore area, and more specially Edgewood.

c. Leeside Trough The position of the Appalachian Mountain s enables formation of a meteorological phenomenon called a “leeside trough.” According to the American Meteorological Association Glossary (2010), a leeside trough is “a pressure trough formed on th e lee side [opposite the wind] of a mountain range in situations where the wind is blowing with a substantial component across the mountain ri dge; often seen on United Stat es weather maps east of the Rocky Mountains, and sometimes east of the Appal achians." This shift in pressure along the trough (the orange dashed line in Figure 4-1) results in westerly to northwesterly flow on the
left side and southerl y flow on the right side. Since th e leeside trough usually develops over Maryland, this phenomenon results in pollutants from the Ohio River Valley and Western

47Pennsylvania, veering (or turning northward) into Mary land and at the same time allows ozone and ozone precursors to be transported from Virginia and North Carolina into Maryland.

Figure 4-1. August 10, 2010 12z Surface Analysis from the Hydrometeorological Prediction Center (HPC)

On August 10, 2010 a lee side trough formed ove r Maryland and the result was an ozone exceedance day, which included pockets of unhealthy air quality (refer to Figure 4-2).

48Figure 4-2. August 10, 2010 EPA AQI Map

d. Nocturnal Low Level Jet Another meteorological phenomenon that resu lts from the location of the Appalachian Mountains to the west and the A tlantic Ocean to the east is the nocturnal low level jet (NLLJ). The NNLJ is a fast moving stream of air that is typically observed be tween the Appalachian Mountains and the Atlantic Ocean during the late night and early morning hours. This fast moving stream of air can reach sp eeds of 40 mph and stretches fr om NC to MD to NJ to MA (refer to Figure 4-3).

In an effort to measure ozone concentrations in the NLLJ, MDE started contracting with the scientists at HU in 2005 to launch ozonesondes during the late night and early morning hours (see the factor 3 Meteorology se ction). Based on these ozonesonde measurements, ozone in excess of 90 ppb has been measured on several o ccasions within the NLLJ (refer to Figure 4- 4).

49Figure 4-3. Extent of the Nocturnal Low Level Jet

Figure 4-4. Ozone Concentrations With in the Nocturnal Low Level Jet 

### W i n d S p e e d a n d W i n d D i r e c t i o n 

### August 25, 2008

Satellite Ima

B e l t s v i l l e , M D N e w B r u n s w i c k , N J S t o w , M A g e

R a l e i g h , N C

8 PM 11 PM 2 A M 5 A M 8 A M 11 A M NLLJ

So u r ce s: NASA, NOAA



### 2:30 AM

50e. True Air Shed Size? The “air shed” that is relevant to the ozone nonattainment area boundary is the same as the “air shed” for the Chesapeake Bay, since both seek to delineate sources of nitrogen oxides (NO
x ) that contribute to federally -regulated pollution (Dennis 1997).

Figure 4-5: States in the Chesapeake Bay Air Shed, from Chesapeake Bay Foundation, http://www.cbf.org/page.aspx?pid=577 , retrieved 2/1/12

As shown in Figure 4-5, the Chesapeake Bay ai r shed includes Maryland, Delaware, Virginia, Pennsylvania, West Virginia, North Carolina, Ohio, most of New Yor k, New Jersey, Kentucky and South Carolina, and parts of Indiana, Te nnessee, Michigan, and Vermont. Therefore, the geography factor supports a nonattainment area at least as large as the entire CSA.

d. Resources Civerolo, K. L., H. T. Mao, and S. T. Rao ( 2003), The airshed for ozone and fine particulate pollution in the eastern United States , Pure Appl. Geophys ., 160(1-2), 81-105.

51Dennis R.L., 1997. Using the regional acid deposition model to determine the nitrogen deposition airshed of the Chesapeake Bay watershed. In: Baker, J., ed., Atmospheric Deposition to the Great Lakes and Coastal Wate rs. Society of Environmental Toxicology and Chemistry : Pensacola, FL; pp. 393-413. Fischer, E. V., R. W. Talbot , J. E. Dibb, J. L. Moody, and G. L. Murray (2004), Summertime ozone at Mount Washington: Meteorological cont rols at the highest peak in the northeast, Journal of Geophysical Research-Atmospheres , 109(D24). Godowitch, J.M., Gilliam, R.C., and Rao, T.S. (2011), Diagnostic evaluation of ozone production and horizontal transport in a regional photoche mical air quality modeling system, Atmospheric Environment , 45, 3977–3987 [NLLJ]. Lai, T.-L., Talbot, R., and Mao, H. (2012), An investigation of two highest ozone episodes during the last decade in New England, Atmospheres , 3, 59–86 [Leeside Troughs and NLLJ] Landry, L. (2011), The influence of the Chesapeake Bay breeze on Maryland air quality, MARAMA Data Analysis Workshop , College Park, MD, January 20–21. Kleinman, L. I., et al. (2004), An ozone ep isode in the Philadelphia metropolitan area, Journal of Geophysical Research-Atmospheres , 109(D20). Loughner, C. P., D. J. Allen, K. E. Pickering, D. L. Zhang, Y. X. Shou, and R. R. Dickerson (2011), Impact of fair-weather cumulus clouds and the Chesapeake Bay breeze on pollutant transport and transformation, Atmospheric Environment , 45(24), 4060-4072. Yorks, J. E., A. M. Thompson, E. Joseph, and S. K. Miller (2009), The variability of free tropospheric ozone over Beltsville, Maryla nd (39N, 77W) in the summers 2004-2007, Atmospheric Environment , 43(11), 1827-1838 [NLLJ] Zhang, D.-L., S. Zhang, and S. J. Weaver (2006), Low-level jets over th e Mid-Atlantic states: Warm-season climatology and a case study, Journal of Applied Meteorology and Climatology , 45, 194–209



### Jurisdictional boundaries The CSA has county boundaries even though it crosses state lines. A nonattainment designation corresponding with th e CSA would have three or more functional sub regions currently performing both air quali ty and transportation planning. While it may be possible to exclude some of the outer ring counties, the fact that these counties are included as part of the CSA indicates their forming ties to the core urban area.

52

### APPENDIX C ZERO OUT MODELING RUNS

Modeling Analysis Results

In effort to determine the regional effect on Maryland’s local air qualit y, a series of zero-out (only anthropogenic emissions were zeroed ou t) CMAQ modeling runs were completed by modelers at the University of Ma ryland College Park (UMD).

The base case modeling used a MARAMA Vers ion 2 2007 emissions inventory and the time period, July 25 – August 17, 2007 was utilized for th is modeling analysis. This particular time period was chosen due to both local and transport driven events being account for. The end of July dates were used for model spin up, so th is analysis focused on the days in August.

Baltimore Zero-Out Modeling Analysis

The Baltimore zero-out modeling analysis was conduc ted to determine, if all emissions in the Baltimore Nonattainment Area (NAA) (Baltimore , Carroll, Howard, An ne Arundel, Harford Counties and Baltimore City) were zeroed out, would all areas in Maryland demonstrate compliance with the 8-hour ozone 75 ppb NAA QS during both local pollution and transport driven events?

After comparing Baltimore NAA no emissions scen arios with those of the base case during local pollution event days it was determined th at certain specific areas in Maryland saw a decrease in ozone, but there were still areas of Maryland which exceeded the 8-hour ozone 75 ppb NAAQS. Refer to Figure 1.

After comparing Baltimore NAA no emissions scen arios with those of the base case during regional pollution event days it was once again determined that certain specific areas in Maryland saw a decrease in ozone, but there were still areas of Maryland which exceeded the 8-hour ozone 75 ppb NAAQS. Refer to Figure 2.

Maryland Zero-Out Modeling Analysis

This modeling analysis was conducted to determin e if all emissions in Maryland were zeroed out, would all areas in Maryland demonstrat e compliance with the 8-hour ozone 75 ppb NAAQS during both local pollution a nd transport driven events?

After comparing Maryland no emi ssions scenarios with those of the base case during local pollution event days it was determined that certai n specific areas in Maryland saw a decrease in ozone, but there were still areas of Ma ryland which exceeded the 8-hour ozone 75 ppb NAAQS. Refer to Figure 3.

After comparing Maryland no emissi ons scenarios with those of the base case during regional pollution event days it was once again determined that certain specific areas in Maryland saw a

53decrease in ozone, but there were still areas of Maryland which exceeded the 8-hour ozone 75 ppb NAAQS. Refer to Figure 4.

Conclusion

Based on this modeling analysis, even if there were no sources of emissions in either the Baltimore NAA or all of Maryland, the State would still not be able to demonstrate compliance with the 8-hour ozone 75 ppb NAAQS.

This modeling analysis clearly demonstrates keeping Maryland as a small nonattainment area will force Maryland to adopt minimally effectiv e and extremely expensive control programs that will not help Maryland a ttain the 8-hour ozone 75 ppb NAAQS. A better course of action would be for other states that contribute to Maryland’s nonattainment problem to implement much more cost-effective control programs that would help slash their pollutant contribution to Maryland and help the State demonstrate co mpliance with the 8-hour ozone 75 ppb NAAQS. This particular approach makes more environmental and economic sense.

54Figure 1. Baltimore NAA Zero-Out Runs - Local Pollutant Events

55Figure 2. Baltimore NAA Zero-Out Runs - Regional Pollutant Events

56Figure 3. Maryland Zero-Out Runs - Local Pollutant Events

5758 Figure 4. Maryland Zero-Out Runs - Regional Pollutant Events