March 18,2009 

Mr. William T. Wisniewski (3RA00) 

Acting Regional Administrator Region I11 U.S. Environmental Protection Agency 

1650 Arch Street 

: Philadelphia, Pennsylvania 19 103-2029 

Dear Administrator Wisniewski: 

On March 12, 2008, the EPA revised the primary and secondary National Ambient Air 

Quality Standards (NAAQS) for ground-level ozone from the current 0.08 parts per million (ppm) 

to a new 0.075 ppm. Section 107(d) of the Clean Air Act (CAA) requires the Governor of each 

State to submit to the EPA a list of all areas (or portions thereof) in the State, designating each as 

nonattainment, attainment, or unclassifiable. This letter fulfills Delaware's obligations under 

Section 107(d) of the CAA. It also recommends the placement of Delaware's counties in nonattainment status under the new 0.075 pprn standard in a non-attainment area. 

Area Description and Attainment/Nonattainment Status 

Delaware is composed of three counties, namely New Castle, Kent and Sussex, laying 

from north to south. The northern portion of New Castle County lies above the Chesapeake and 

Delaware Canal, a waterway that connects the Chesapeake Bay with the Delaware Bay. This 

part of New Castle County is more metropolitan and industrialized than the remainder of 

Delaware. The remainder of Delaware lies south of the Chesapeake and Delaware Canal, and 

comprises the southern portion of New Castle County, and all of Kent and Sussex Counties. All 

three counties share similar air quality problems with respect to ozone, because the problem is 

predominantly caused by ozone and ozone precursor emissions from upwind states. 

Delaware's ozone monitoring network includes ambient ozone monitors in each of its 

counties (three monitors in New Castle, one monitor in Kent, and one monitor in Sussex). Based 

on 2006 through 2008 ozone monitoring data (i.e., the most recent three years), the 8-hour ozone 
Placement of Delaware's Counties in a Large Nonattainment Area 

Ground-level ozone and ozone precursor emissions are pervasive and readily transported. 

Numerous epidemiological studies conducted during the past decade have revealed that 

prolonged (i.e., 8-hour) exposure to ozone is associated with increased mortality and a range of 

serious morbidity health effects, including aggravation of a variety of respiratory symptoms and 

lung impairment, asthma attacks, respiratory hospital admissions and emergency department 

visits, and cardiovascular problems. This level of ozone concentration is also associated with 

adverse public welfare effects, which include impacts on vegetation, and forest ecosystems, and agricultural crop yields. The pervasive nature of ozone, and the serious adverse health and 

welfare effects associated with ozone, non-attainment make non-attainment boundary 

determinations critical. 

Under the 1997 8-hour ozone NAAQS, the EPA included Delaware's three counties 'in 

the Philadelphia-Wilmington-Trenton Nonattainment Area. In establishing this area the EPA 

relied on their policy presumption of using Consolidated Metropolitan Statistical Area (CMSA) 

boundaries and the prior 1-hour nonattainment area (NAA) boundaries as 8-hour nonattainment 

area boundaries, except they also considered the impact of upwind emissions and included Ocean 

County, NJ, despite Ocean County, NJ being part of the New York CMSA. Delaware believes 

that full consideration of upwind contribution when establishing non-attainment boundaries is 

necessary because ozone and ozone precursor emissions are pervasive and readily transported. It 

is important that the emissions that are causing Delaware's ozone problem be subject to the CAA 

non-attainment requirements. 

In its guidance entitled "Area Designation for the 2008 Revised Ozone NAAQS 

(December 4, 2008)," EPA recommends using the Core Based Statistical Area (CBSA) or 

Combined Statistical Area (CSA), similar to the previous CMSA concept, to delineate 

nonattainment boundaries. In the guidance, EPA recognizes that upwind contribution is 

significant, and indicates that "In addition to nearby areas with sources contributing to 

nonattainment, ozone concentrations in a local area may be affected by long-range transport of 

ozone and its precursors (notably nitrogen oxides). In certain parts of the country, such as the 

eastern United States, ozone is a widespread problem." However, in this guidance document 

EPA also indicted that where this is the case, the CAA does not require that all contributing areas 

be designated nonattainment, but only the nearby areas; and that regional strategies, such as 

those employed in the Ozone Transport Region and EPA's NOx SIP Call are needed to address 

the long-range transport component of ozone nonattainment, while the local component must be 

addressed through local planning in and around the designated nonattainment area. The EPAYs 

practice being guided by this interpretation has led to a separation between regional controls and 

local controls, which has been proved to be substantially ineffective in ozone NAAQS strategy 
meet (or that contributes to ambient air quality in a nearby area that does not meet) the national 

primary or secondary, ambient air quality standard for the pollutant." In the context of a regional 

problem like ozone nonattainment, the term "nearby" must be interpreted consistent with the 

scale of the problem and the nature of the pollutant. For the purposes of solving air quality 

problems associated with pollutants like sulfur dioxide and; carbon monoxide, CMSA or 

CBSNCSA scale boundaries have proven adequate. This is because concentrations of these 

pollutants above the standard are generally driven by emission sources that are very close, 

geographically and do not involve complex atmospheric chemistry. However, this is not the case 

with ozone. Over the past 35+ years, and in particular since 1990, Delaware's local sources of 

ozone precursor emissions have all been well controlled, yet Delaware's air quality remains nonattainment relative to ozone. High ozone concentrations in Delaware are not driven by emission 

sources that are geographically close, but rather emissions sources that are many miles away. 

Given this, Delaware believes that it is necessary to consider regional transport of ozone and 

ozone precursor emissions in establishing non-attainment area boundaries. More specific 

reasons for this belief include: 

The CBSNCSA approach is based on census data rather than air-shed monitoring andfor 

analysis data. Census data, in comparison to air-shed data, represents a poor surrogate 

for determining ozone non-attainment boundaries. This is particularly true for areas like 

Delaware that are heavily affected by long-range transport of ozone and ozone precursors. 

Detailed regional air-shed studies have been completed in the past decade or so, such as the Regional Oxidant Modeling (ROM) project covering most of the Ozone Transport 

Region (OTR) states, the Ozone Transport Assessment Group (OTAG) project, the NOx 

SIP Call analysis covering most of the Eastern U.S., and the EPA Clean Air Interstate 

Rule (CAIR) analysis. These studies have demonstrated that the ozone problem is 

transport-driven and regional in scope, rather than localized or confined to the relatively 

small CBSNCSA domains. 

The studies mentioned above have further demonstrated that individual CBSNCSA 

based non-attainment areas do not have the ability to achieve attainment regardless of the 

levels of emission controls they implement within their own jurisdictional boundaries. 

Delaware believes that this conclusion should become the cornerstone of good air quality 

planning and policy, starting with the crucial boundary determinations. 

In many downwind nonattainment areas, including Delaware, the air coming into a 

county is often with ozone concentration greater than 0.075 ppm (i.e., greater than 

NAAQS). Therefore, it becomes impossible for such an area to solve its non-attainment 

problem under its own authority. The CBSNCSA approach has led to situations where 

many downwind areas are struggling with non-cost-effective controls to reduce ambient 

ozone components that come from upwind areas that are not subject to the reasonable 

emission control requirements. As a result, protection of public health in those 
NAAQS, however, the most success toward attainment of ozone NAAQS in the OTR to 

date is attributable to national measures taken by the EPA, and regional measures 

developed and adopted by the Ozone Transport Commission (OTC) member states. The 

area is also facing with having to implement measures that will provide diminishing 

returns. We are revisiting standards for a second or third time for sectors that go ' 

uncontrolled in the contributing upwind states. 

In its December 4, 2008 guidance, EPA recommends nine factors for states to use to 

justify their boundary recommendations. The EPA states its rationale for recommending these 

factors as being that they are similar to the ones'used to establish CBSAs and CSAs. Delaware 

believes, however, using these factors to justify, ozone non-attainment boundaries because they 

are similar to the ones used to establish CBSAs and CSAs is not appropriate. Instead, boundary 

recommendations must be evaluated with consideration given to the pervasive nature of the 

pollutant ozone, and the ozone/precursor transport issue discussed above. 

Based on the above discussion Delaware recommends that EPA include Delaware's three 

counties in a single multi-state regional large nonattainment area (NAA) that includes all 

counties in the states of Maryland, Michigan, New Jersey, New York, North Carolina, .Ohio, 

Pennsylvania, Virginia, and West Virginia. This area encompasses the emissions that are 

causing Delaware's ozone non-attainment problems, and rationale for it is more fully described 

in the CAA Section 126 petition that Delaware submitted to the EPA on December 15, 2008. A 

map that details Delaware's recommended nonattainment area boundaries is attached to this 

letter. 

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Delaware believes that this approach would: 

Reinforce the science-based and wide-accepted fact that ozone non-attainment is a 

"regional problem" and not only a "local problem"; Include all or most of the counties necessary to solve this regional problem, give them a vested interest in solving this regional problem, and foster cooperative development and 

implementation of control strategies that are most effective to solving the wide-spread ozone nonattainment problem; Remove political barriers and level the playing field by setting the consistent baseline of 

control requirements of Subpart 2 of Title I, Part D of the CAA within the region, which 

include New Source Review (NSR), vehicle Inspection and Maintenance, and highly 

cost effective Reasonably Available Control Technology (RACT) requirements; Effectively compliment national and regional rules that address regional transport; 

Greatly simplify and provide equity to the process of implementing the new 8-hour 

NAAQS. 
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Greatly simplify and provide equity to the process of implementing the new 8-hour 

NAAQS. 

Delaware believes that the above large-NAA recommendation represents the most 

effective and economical way to address the pervasive ozone nonattainment problem in the 

northeast region. If, however, the EPA chooses not to embrace the above recommendation (i.e., 

not to fully consider upwind contribution in setting nonattainment boundaries, and not to 

establish a large regional.,ozone non-attainment area), despite our confidence that is a better 

course of action, then ela aware proposes that the EPA establish Delaware as a stand-alone ozone 

nonattainment area (i.e., the geographical boundaries of Delaware constitute Delaware's ozone 

nonattainment boundaries). Delaware suggests this stand-alone alternative not because it is the 

best approach to clean the air, but rather because it is more rationale than a CBSAICSA 

supported designation under the muse that emissions within the CBSAICSA area are causing the 

nonattainment problem. Note that Delaware's ozone nonattainment problems are mainly caused 

by long-range ozonelprecursor transport from upwind sources, and under this approach the EPA 

would need to commit to develop and implement effective regional controls to completely mitigate o~onelprecursor transport in the timeframe of Delaware (and other downwind states) 

attainment schedule according to the CAA. 

Thank you for your consideration of the above recommendations. If you feel you cannot 

support the large non-attainment boundary approach discussed above Delaware would like to 

have an opportunity to continue this discussion before you propose any modification. If you 

have any questions concerning this submittal or would like to discuss it further, please contact 

Mr. Ali Mirzakhalili, the administrator of our air quality management section, at (302)739-9402. 

Jack A. Markell 

Governor 

pc: Dave Small 

Jim Werner Ali Mirzakhalili Judith Katz 
Delaware Recommended 8-hour Ozone Non-attainment Boundaries