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Technical Support Document for 2008 Ozone NAAQS Designations

EPA Region 2

New Jersey

Area Designations for the 

2008 Ozone National Ambient Air Quality Standards

Note: New Jersey recommended that EPA designate the entire State as part of a large multi-state 

nonattainment area including all or portions of eleven states. Section 107(d) of the CAA requires EPA 

to designate as nonattainment all areas violating the ozone NAAQS and any nearby areas that are 

contributing to a violation in another area. Under the designation provision, only "nearby" areas that 

contribute to the violation must be included as part of the nonattainment area. There are other 

provisions of the CAA that address longer range transport of ozone pollutions, such as sections 

110(a)(2)(D), 126, and 184. The phenomenon of ozone transport must be balanced against the need to 

have smaller areas that can focus on local control measures. We note that most of the States that New 

Jersey seeks to include as part of this large nonattainment area did not make a similar request. While a 

few other states did request that EPA designate a broad area in the eastern part of the United States as 

nonattainment, each of those recommendations varied from the others. In the absence of broad 

agreement among a large group of states to create such a large nonattainment area, demonstrating a 

commitment to work together to address both long-range and local transport of emissions, we do not

intend to designate a large nonattainment area as suggested by New Jersey. The rest of this TSD will 

evaluate New Jersey’s request for designations within its state only.

The table below identifies the areas and associated counties or parts of counties in the State of New 

Jersey that EPA intends to designate as nonattainment for the 2008 ozone national ambient air quality 

standards (2008 NAAQS). In accordance with section 107(d) of the Clean Air Act, EPA must designate 

an area (county part of a county) “nonattainment” if it is violating the 2008 ozone NAAQS or if it is 

contributing to a violation of the 2008 ozone NAAQS in a nearby area. The technical analyses 

supporting the boundaries for the individual nonattainment areas are provided below.

Table 1. Intended Nonattainment Areas in New Jersey

Area 

New Jersey’s Recommended 

Nonattainment Counties

EPA’s Intended Nonattainment 

Counties

New York – Northern New 

Jersey – Long Island, NY- NJCT Area* (NJ portion)

Bergen, Essex, Hudson, 

Hunterdon, Middlesex, 

Monmouth, Morris, Passaic, 

Somerset, Sussex, Union, and 

Warren

Bergen, Essex, Hudson, 

Hunterdon, Middlesex, 

Monmouth, Morris, Passaic, 

Somerset, Sussex, Union, and 

Warren

Philadelphia-WilmingtonAtlantic City, PA-NJ-DE-MD

Area* (NJ portion)

Atlantic, Burlington, Camden, 

Cape May, Cumberland, 

Gloucester, Mercer, Ocean, and 

Salem

Atlantic, Burlington, Camden, 

Cape May, Cumberland, 

Gloucester, Mercer, Ocean, and 

Salem

*This nonattainment area is a multi-state nonattainment area. 
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These proposed nonattainment areas in New Jersey, which EPA intends to designate as nonattainment,

include all of the counties in New Jersey. Therefore, at New Jersey’s request, no counties in New Jersey 

will be classified as “unclassifiable/attainment” for the 2008 ozone NAAQS. 

The analysis below provides the technical basis for intended nonattainment area boundaries. It is based 

on an evaluation of which nearby areas are contributing to violations at monitors in New Jersey, 

particularly, Mercer and Ocean Counties. EPA has evaluated the boundaries proposed by New Jersey 

based on a weight of evidence analysis considering the factors identified below. EPA issued guidance 

on December 4, 2008 that identified these factors as ones EPA would consider in determining 

nonattainment area boundaries and recommended that states consider these factors in making their 

designations recommendations to EPA.

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1. Air quality data (including the design value calculated for each FRM or FEM monitor in the 

area);

2. Emissions and emissions-related data (including location of sources and population, amount of 

emissions and emissions controls, and urban growth patterns);

3. Meteorology (weather/transport patterns);

4. Geography and topography (mountain ranges or other basin boundaries);

5. Jurisdictional boundaries (e.g., counties, air districts, existing nonattainment areas, Indian 

country, metropolitan planning organizations (MPOs))

Ground-level ozone is not emitted directly into the air, but is created by chemical reactions between 

oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Because 

NOx and VOC emissions from a broad range of sources over a wide area typically contribute to 

violations of the ozone standards, EPA believes it is important to consider whether there are contributing 

emissions from a broad geographic area. Accordingly, EPA chose to examine five factors with respect 

to the larger of the Combined Statistical Area (CSA) or Core Based Statistical Area (CBSA) associated 

with the violating monitor(s).

2 All data and information used by EPA in this evaluation are the latest 

available to EPA and/or provided to EPA by states or tribes. 

In New Jersey’s case, the State of New Jersey has asked EPA to use boundaries corresponding to the 

existing nonattainment areas for the 1997 eight-hour ozone NAAQS, as designated in 2004. EPA will 

focus its analysis on whether the boundaries for New Jersey’s proposed nonattainment areas for the 

2008 eight-hour ozone NAAQS are still supported by available data. EPA intends to approve New 

Jersey’s request to use the previous 1997 eight-hour ozone standard’s nonattainment area boundaries 

unless more recent information changes the preponderance of evidence that Ocean and Mercer Counties 

are properly affiliated with the Philadelphia-Wilmington-Atlantic City (PA-NJ-DE-MD) nonattainment 

area for ozone.

 

1 The December 4, 2008 guidance memorandum “Area Designations for the 2008 Revised Ozone National Ambient Air 

Quality Standards” refers to 9 factors. In this technical support document we have grouped the emissions-related factors 

together under the heading of “Emissions and Emissions-Related Data,” which results in 5 categories of factors.

2 Lists of CBSAs and CSAs and their geographic components are provided at 

www.census.gov/population/www/metroareas/metrodef.html . The lists are periodically updated by the Office of 

Management and Budget. EPA used the most recent update, based on 2008 population estimates, issued on December 1, 

2009 (OMB Bulletin No. 10-02).
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Technical Analysis for Philadelphia-Wilmington-Atlantic City (PA-NJ-DE-MD) Area and the New 

York – Northern New Jersey – Long Island (NY, NJ, CT) Area

Figure 1 

Figure 1 is a map of the Philadelphia-Wilmington-Vineland CSA and surrounding areas, with the 

Philadelphia-Wilmington-Atlantic City (PA-NJ-DE-MD) intended nonattainment area marked in blue. 

The map provides other relevant information including the locations and design values of air quality 

monitors, county and other jurisdictional boundaries. 

The metropolitan area boundary is smaller than the nonattainment area proposed by New Jersey, which 

has requested that EPA continue with the boundaries approved for the New Jersey portion of the 

existing1997 ozone NAAQS nonattainment area. New Jersey has not proposed any counties in New 

Jersey as attainment, so there will be no factor analysis for attaining counties. EPA believes the factors 

still support New Jersey’s recommendation for which counties should be affiliated with the New York 

City or Philadelphia nonattainment areas. There are no recognized tribal lands in New Jersey for the 

purposes of air quality designations. 

New Jersey’s recommendation for boundaries for its nonattainment areas was submitted to EPA in its 

April 1, 2009 letter to EPA. Neither the New York City or Philadelphia areas were attaining the 2008 
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ozone NAAQS based on air quality data used in New Jersey’s letter or the most recent data from 2008-

2010. These data are from Federal Reference Method (FRM) monitors sited and operated in accordance 

with 40 CFR Part 58, in a network designed to be representative of ozone concentrations across the State 

and approved by EPA for this purpose. 

After considering these recommendations and based on EPA's technical analysis described below, EPA 

intends to designate the counties listed in Table 1, above as “nonattainment” for the 2008 ozone 

NAAQS.

Figure 2
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Figure 2 is a map of the New York-Northern New Jersey-Long Island (NJ-NY-CT-PA) CSA and 

surrounding areas, with the New York-Northern New Jersey-Long Island (NY-NJ-CT) intended 

nonattainment area marked in blue. The map provides other relevant information including the locations 

and design values of air quality monitors, county and other jurisdictional boundaries. 

The nonattainment area proposed by New Jersey is different from the metropolitan area boundaries. 

New Jersey has requested that EPA continue with the boundaries approved for the New Jersey portion of 

the existing1997 ozone NAAQS nonattainment area. New Jersey has not proposed any counties in New 

Jersey as attainment, so there will be no factor analysis for attaining counties. EPA believes the factors 

still support New Jersey’s recommendation for which counties should be affiliated with the New York 

City or Philadelphia nonattainment areas. There are no recognized tribal lands in New Jersey for the 

purposes of air quality designations. 

New Jersey’s recommendation for boundaries for its nonattainment areas was submitted to EPA in its 

April 1, 2009 letter to EPA. Neither the New York City or Philadelphia areas were attaining the 2008 

ozone NAAQS based on air quality data used in New Jersey’s letter or the most recent data from 2008-

2010. These data are from Federal Reference Method (FRM) monitors sited and operated in accordance 

with 40 CFR Part 58, in a network designed to be representative of ozone concentrations across the State 

and approved by EPA for this purpose. 

After considering these recommendations and based on EPA's technical analysis described below, EPA 

intends to designate the counties listed in Table 1, above as “nonattainment” for the 2008 ozone 

NAAQS.

Factor Assessment For the Philadelphia-Wilmington-Atlantic City Area and the New York CityNorthern New Jersey-Long Island Area

Since New Jersey proposes that the entire state be designated as nonattainment for the 2008 ozone 

NAAQS, the only issue for a factor analysis is the location of the boundary line between the New York 

City and Philadelphia nonattainment areas. 

Here are the factors that EPA considers when determining the boundaries of a nonattainment area:

1. Air quality data (including the design value calculated for each FRM or FEM monitor in the 

area); 

Both Ocean and Mercer Counties violate the air quality standard; with Ocean County having a 

higher design value than any monitors further downwind of Ocean County, except the peak 

monitors downwind of New York City. 

2. Emissions and emissions-related data (including location of sources and population, amount of 

emissions and emissions controls, and urban growth patterns);

This factor has a limited relevance to this issue, as the issue is whether the Ocean and Mercer 

Counties are more affected by the Philadelphia nonattainment area than the New York City area. 

However, one factor from the 2004 analysis noted that more commuters stay in Ocean County or 

go to the Philadelphia area than go to the New York City area.3

3. Meteorology (weather/transport patterns);

The 2004 analyses of the evaluation of boundaries for the 1997 ozone NAAQSishow that Ocean 

County is much more likely to be impacted by winds from the Philadelphia area than winds from 

 

3

 This factor uses Census Bureau data from 2000, which will be updated if newer data are available.
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the New York City area. It is unlikely that more recent data would show a reversal of this wind 

pattern. However, more recent wind rose data will be evaluated to see if supports those analyses 

and continues to support Mercer and Ocean County as part of the Philadelphia area.

4. Geography and topography (mountain ranges or other basin boundaries);

Not much of a factor, since there are no major topographic features affecting conclusions from

the wind flow analyses.

5. Jurisdictional boundaries (e.g., counties, air districts, existing nonattainment areas, Indian 

country, metropolitan planning organizations (MPOs)) 

Ocean County is part of the NYC transportation planning area and Mercer County is part of the 

Philadelphia planning area. However, Ocean and Mercer Counties have been in the Philadelphia 

nonattainment area since 2004. New Jersey’s desire to continue to include Ocean and Mercer 

Counties in the Philadelphia area will tend to prevail, since New Jersey has to deal with any 

inconveniences due to transportation planning areas that are different from the nonattainment 

areas.

EPA finds that only some of the factors are relevant to determining if the boundaries of the New York 

City and Philadelphia areas in the State of New Jersey are approvable. The following sections provide 

additional information, as available and relevant.

Factor 1: Air Quality Data 

Air quality data is based on the 8-hour ozone design values (in ppb) for air quality monitors in New 

Jersey, based on data for the 2008-2010 period (i.e., the 2010 design value, or DV). These are the most 

recent years with fully-certified air quality data. A monitor’s DV is the metric or statistic that indicates 

whether that monitor attains a specified air quality standard. The 2008 ozone NAAQS are met when the 

annual fourth-highest daily maximum 8-hour average concentration, averaged over 3 years is 0.075 ppm 

(75ppb) or less. A DV is only valid if minimum data completeness criteria are met. See 40 CFR part 50 

Appendix P. Where several monitors are located in a county (or a designated nonattainment area or 

maintenance area), the DV for the county or area is determined by the monitor with the highest level.
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The 2010 DVs for the ozone NAAQS for counties in the Philadelphia-Wilmington-Atlantic City area 

and the New York – Northern New Jersey – Long Island, NY, NJ, CT nearby surrounding area are 

shown in Table 2.

Table 2. Air Quality Data.

The highest design value in NJ is 81ppb in Ocean and Gloucester Counties. The highest design value in 

the intended Philadelphia nonattainment area is 83ppb in Bucks Co., PA. The highest design value in 

the intended New York City nonattainment area is 84 ppb in Suffolk County, Long Island, NY

2010 NJ O3 DV.pdf

As shown in Figures 1 and 2, design values decrease further north and east from Ocean County, until the

next set of peak design values occur downwind of New York City on Long Island and in Connecticut. 

This is an indication that Ocean County is affected strongly and mostly by sources to the south and west, 

which includes the Philadelphia area. This is typical of the northeastern United States, since most of 

peak ozone design values are found north and east of the centers of major urban areas.
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Factor 2: Emissions and Emissions-Related Data

How does this factor support New Jersey’s request for Ocean and Mercer Counties to be included in the 

prospective Philadelphia nonattainment area? 

Emissions Data

Not evaluated because: There are no counties proposed to be attainment in New Jersey.

The only issue, whether Mercer and Ocean Counties should continue to be included with the 

Philadelphia area as opposed to the New York area, does not use this factor as a deciding factor. The 

question that needs a multi-factor analysis is about whose emissions affect Ocean and Mercer Counties 

the most. 

Population density and degree of urbanization

Not evaluated since the question is the impact of urban ozone on Ocean and Mercer County and less so 

about whether Ocean and Mercer Counties affect other areas. 

Traffic and commuting patterns

EPA evaluated the commuting patterns of residents in the area. A neighboring county with high VMT 

and/or a high number of commuters coming into the county with a violating monitor is generally an 

integral part of an urban area and indicates the presence of motor vehicle emissions that may contribute 

to ozone formation. Rapid population or VMT growth in a county on the urban perimeter signifies 

increasing integration with the core urban area, and indicates that the associated area source and mobile 

source emissions may be appropriate to include in the nonattainment area. The attached spreadsheet 

shows traffic and commuting pattern data, including total 2008 VMT* and 10-year VMT growth, 

number of commuters in each county who drive to another county within the area, the percent of total 

commuters in each county who commute to other counties within the area**, and the total vehicle miles 

traveled (VMT) for each county.

* MOBILE model VMTs are those inputs into the NEI version 1.5. 

** U.S. Census Bureau estimates for 2000 County-to-County Worker Flow 

http://www.census.gov/hhes/commuting/data/commuting.html.

The County-to-County Worker Flow data from 2000 was used in the previous 2004 analysis for the 

1997 ozone standard. More up-to-date data will be used in the final analysis as available.

Based on 2000 data, the 2004 analysis noted that more commuters either stay in Ocean County or go to 

the Philadelphia area than go to the New York City area.

Factor 3: Meteorology (weather/transport patterns)

EPA evaluated any available meteorological data to help determine how meteorological conditions, such 

as weather, transport patterns and stagnation conditions, would affect the fate and transport of precursor 

emissions contributing to ozone formation. 
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Wind rose for 1988-1992

.

The 1997 designation assessment showed, via wind roses (see above), trajectory analysis and 

contribution assessments, that Ocean County (and by extension, Mercer County) are downwind of the 

Philadelphia metropolitan area and are not as strongly affected by emissions from the New York City 

metropolitan area. EPA is evaluating more recent data and believes that wind patterns have not changed 

substantially enough to reverse the wind patterns in the northeastern United States. 

Factor 4: Geography/topography (mountain ranges or other air basin boundaries)

New Jersey’s division of its nonattainment areas into two areas is not based on topographic barriers. 
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Factor 5: Jurisdictional boundaries

Once the general areas to be included in the nonattainment area were determined, EPA considered

existing jurisdictional boundaries for the purposes of providing a clearly defined legal boundary and 

carrying out the air quality planning and enforcement functions for nonattainment areas. Examples of 

jurisdictional boundaries include existing/prior nonattainment areas for ozone or other urban-scale 

pollutants, counties, air districts, townships, metropolitan planning organizations, state lines, 

Reservations, urban growth boundary, etc. Where existing jurisdictional boundaries are not adequate to 

describe the nonattainment area, other clearly defined and permanent landmarks or geographic 

coordinates were considered.

EPA approved the inclusion of Ocean and Mercer Counties into the Philadelphia nonattainment area for 

the 2004 ozone nonattainment designations. 

Ocean County is in the New York City metropolitan transportation planning organization. Mercer 

County is in the Philadelphia metropolitan transportation planning organization. Since 2004, New 

Jersey has worked with Ocean County being within the Philadelphia nonattainment area and in the New 

York City-centered transportation planning organization. If New Jersey requests that Ocean County 

should be included with the Philadelphia nonattainment area despite the possible difficulties of this 

situation, this factor should not be a reason for declining New Jersey’s request. 

New Jersey’s nonattainment areas do not include Indian county for the purposes of this analysis. As 

defined at 18 U.S.C. 1151, “Indian country” refers to: “(a) all land within the limits of any Indian 

reservation under the jurisdiction of the United States Government, notwithstanding the issuance of any 

patent, and, including rights-of-way running through the reservation, (b) all dependent Indian 

communities within the borders of the United States whether within the original or subsequently 

acquired territory thereof, and whether within or without the limits of a state, and (c) all Indian 

allotments, the Indian titles to which have not been extinguished, including rights-of-way running 

through the same.” EPA recognizes the sovereignty of tribal governments, and has attempted to take the 

desires of the tribes into account in establishing appropriate nonattainment area boundaries.

Conclusion

EPA will continue to evaluate updated information as to why Mercer and Ocean Counties should be in 

the Philadelphia ozone nonattainment area as it was for the previous 1997 eight-hour ozone standard. 

EPA’s preliminary determination is to have the entire State of New Jersey designated as nonattainment 

for the 2008 eight-hour ozone NAAQS.

 

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http://www.epa.gov/ozonedesignations/1997standards/documents/tsd/ch3.pdf