UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

1650 Arch Street

Philadelphia, Pennsylvania 19103

DATE: OCT — 62010

SUBJECT: Technical Support Document Regarding Ozone Monitoring Data — Delaware,

Maryland, Pennsylvania; One-Year Extension for Attaining the 1997 8-Hour

Ozone Standard for the Delaware, Maryland, and Pennsylvania Portions ofthe

Philadelphia-Wilmington-Atlantic City Moderate Nonattainment Area

)fla. .

FROM: Maria A. Pino, Air Quality Planmng Specialist

Office of Air Program Planning

TO: File

THRU: BrianK. Rehn, Acting Associate Director

Office of Air Program Planning

This document provides a technical review ofthe air quality monitoring data used to support the

approval of the attainment date extension requests for the Delaware, Maryland, and Pennsylvania

portions ofthe Philadelphia-Wilmington-Atlantic City nonattainment area (Philadelphia Area),

which is classified as moderate for the 1997 8-hour ozone national ambient air quality standard

(NAAQS).

A. BACKGROUND

The Philadelphia Area consists of Cecil County in Maryland; Bucks, Chester, Delaware,

Montgomery and Philadelphia Counties in Pennsylvania; the entire State of Delaware; and

Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester, Mercer, Ocean, and Salem

Counties in New Jersey. Since this area was classified as a moderate ozone nonattainment area,

the statutory ozone attainment date, as prescribed by section 181(a) ofthe Clean Air Act (CAA),

is June 15, 2010. The Commonwealth of Pennsylvania and the States of Maryland and Delaware

(the States) requested a one-year attainment date extension for the Philadelphia on January 8,

2010, March 12, 2010, and May 18, 2010, respectively. The States’ requested that the

attainment date be extended to June 15, 2011.

Section 1 72(a)(2)(C) of subpart 1 of the CAA provides for EPA to extend the attainment date for

an area by one year ifthe State has complied with all the requirements and commitments

pertaining to the area in the applicable implementation plan and no more than a minimal number

of exceedances ofthe NAAQS has occurred in the attainment year. Up to two one-year

extensions may be issued for a single nonattainmeflt area. Section 181 (a)(5) of subpart 2
contains a similar provision for the ozone NAAQS, but instead of providing for an extension

where there has been a “minimal” number of exceedances, it allows an extension only ifthere is

no more than one exceedance ofthe NAAQS in the year proceeding the extension year.

However, the language in sectiori 181 (a)(5) reflects the form ofthe 1-hour ozone NAAQS and

not the 1997 8-hour ozone NAAQS. In EPA’s Final Rule To Implement the 8-Hour Ozone

National Ambient Air Quality — Phase 1(69 FR 23951), known as the Phase I rule, EPA sets

forth how sections 172(a)(2)(C) and 181(a)(5) apply to an area subject to the 1997 8-hour ozone

NAAQS. These requirements, codified in 40. CFR 51.907, are as follows:

An area will meet the requirement ofsection 1 72(a)(2)(C)(ii) or 181 (a)(5)(B) ofthe CAA

pertaining to 1-year extensions ofthe attainment date if:

(a) For the first 1-year extension, the area’s 4th highest daily 8-hour average in the

attainment year is 0.084 ppm or less.

(b) For the second 1-year extension, the area’s 4th highest daily 8-hour value, averaged

over both the original attainment year and the first extension year, is 0.084 ppm or less.

(c) For purposes of paragraphs (a) and (b) ofthis section, the area’s 4th highest daily 8-

hour average shall be from the monitor with the highest 4th highest daily 8-hour

average of all the monitors that represent that area.

B. EVALUATION OF AIR QUALITY MONITORING DATA

I. Data Requirements

As stated above, for the first 1-year extension, the area’s 4th highest daily 8-hour average in the

attainment year is 0.0 84 ppm or less. In order to determine ifthis criterion has been met, the data

handling conventions of Appendix I of 40 CFR 50 (Appendix I) must be followed. This

appendix sets out the data handling conventions and calculations necessary for determining

whether the 1997 8-hour ozone NAAQS have been met at any given ambient ozone air quality

monitoring site.

For the Philadelphia Area, the ozone season extends from the beginning of April through the end

of October. A complete ozone season consists of 214 monitoring days. According to Appendix

I, at least 75% data capture is required each year. For years where there is less than 75% data

completeness, certain data substitution is allowed.

“When computing whether the minimum data completeness requirements have been met,

meteorological or ambient data may be sufficient to demonstrate that meteorological

conditions on missing days were not conducive to concentrations above the level ofthe

standard. Missing days assumed less than the level of the standard are counted for the

purpose of meeting the data completeness requirement, subject to the approval of the

appropriate Regional Administrator.”

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IL Recorded Air Quality Monitoring Data

The States submitted complete, quality assured air quality monitoring data into the Air Quality

Management System (AQS). EPA then concurred on the States’ data. Attached are two AQS

reports for the 2007-2009 ozone seasons. The first report is for the Delaware, Maryland, and

Pennsylvania portions ofthe Philadelphia Area. The second report is for the New Jersey Portion

ofthe Philadelphia Area. Table 1, below, summarizes those reports.

As shown below in Table 1, all 8-hour ozone

4th maximum air quality monitoring values in the

Philadelphia Area were 0.084 ppm or less in 2009. In fact, the highest 4t1 maximum value in the

Philadelphia in 2009 was .074 ppm.

Table 1. 2007-2009 8-Hour Ozone Air Quality Monitoring Data for the Philadelphia Area

Monitoring City County State Year % Days Valid Days 4th Max

Site ID Observed Measured Value

10-001-0002 Notinacity Kent DE 2007 99 211 .078

2008 100 213 .081

2009 99 211 .066

10-003-1007 Not in a city New Castle DE 2007 99 211 .081

2008 99 212 .078

2009 90 193 .068

10-003-10 10 Not in a city New Castle DE 2007 94 202 .086

2008 95 203 .082

2009 53 113 .068

10-003-1013 Wilmington New Castle DE 2007 100 213 .077

2008 100 214 .077

2009 97 207 .069

10-005-1002 Seaford Sussex DE 2007 98 210 .081

. 2008 99 211 .081

2009 98 209 .067

10-005-1003 Lewes Sussex DE 2007 51 109 .080

2008 100 214 .079

2009 97 207 .069

24-015-0003 Not in a city Cecil MD 2007 98 209 .092

2008 97 207 .088

2009 94 201 .072

42-017-0012 Bristol Bucks PA 2007 80 172 .102

2008 98 210 .089

2009 100 213 .074

42-029-0 100 Not in a city Chester PA 2007 93 200 .081

2008 99 212 .084

2009 98 210 .067

42-045-0002 Chester Delaware PA 2007 99 211 .086

2008 100 214 .081

2009 98 210 .065

3
Monitoring City County State Year % Days Valid Days 4th Max

Site ID Observed Measured Value

42-091-0013 Norristown Montgomery PA 2007 98 209 .084

• 2008 97 207 .084

2009 100 214 .070

42-101-0004 Philadelphia Philadelphia PA 2007 100 213 .073

2008 98 209 .062

, 2009 99 212 .059

42-101-0014 Philadelphia Philadelphia PA 2007 99 211 .081

42-101-0024 Philadelphia Philadelphia PA 2007 100 213 .095

. 2008 100 214 .087

2009 71 152 .072

42-101-0136 Philadelphia Philadelphia PA 2007 82 175 .082

34-001-0005 Galloway Atlantic NJ 2007 92 197 .072

Township

34-001-0006 Not in a city Atlantic NJ 2007 92 196 .078

2008 95 204 .072

2009 94 201 .071

34-007-0003 Camden Camden NJ 2007 97 207 .092

2008 81 174 .083

34-007-1001 Not in a city Camden NJ 2007 92 196 .091

2008 98 210 .082

2009 96 205 .071

3401 1-0007 Vineland Cumberland NJ 2007 98 210 .083

2008 98 210 .079

2009 99 212 .072

34-015-0002 Not in a city Gloucester NJ 2007 86 183 .089

2008 96 206 .089

2009 99 211 .071

34021-0005 Lawrence Mercer NJ 2007 97 207 .094

Township 2008 99 212 .079

2009 97 208 .071

34-029-0006 Not in a city Ocean NJ 2007 95 203 .086

. 2008 100 213 .085

2009 98 210 .071

III. Data Issues

A. Less than 75% data completeness for 2009 data

Philadelphia County

In 2009, monitor 42-101-0024 in Philadelphia County, PA, recorded data for 71% ofthe required

days. Failure of an exhaust fan pump caused the monitor to be out of operation for 42 days, from

September 16, 2009 to October 26, 2009. On April 29, 2010, the Philadelphia Department of

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Public Health Air Management Services (AMS), which runs the air quality monitoring network

in Philadelphia County, submitted a data substitution analysis for this monitor for the 2009 ozone

season. That analysis, dated March 29, 2010, uses the data substitution provisions of Appendix I

to 40 CFR Part 50 to determine that 29 days in that 42-day period of down time had metrological

conditions that were not conducive to ozone formation above the level ofthe 2008 ozone

NAAQS, 0.075 ppm. Based on this analysis, AMS requested that missing monitoring data for

those 29 days be counted in determining data completeness for 2009. EPA Regional

Administrator Shawn M. Garvin approved that request in a letter dated May 17, 2010. AMS’s

data substitution analysis and EPA’s approval letter are attached.

New Castle County

In New Castle County, DE, monitor 10-003-10 10 recorded data on 53% ofthe required days in

2009. The Delaware Department ofNatural Resources and Environmental Control (DNREC)

submitted a data substitution analysis for this monitor for the 2009 ozone season. That analysis,

dated July 19, 2010, uses the data substitution provisions of Appendix Ito 40 CFR Part 50 to

determine that 55 of the days when monitor 10-003-10 10 was down in 2009 had metrological

conditions that were not conducive to ozone formation above the level ofthe 2008 ozone

NAAQS, 0.075 ppm. Based on this analysis, DNREC requested that missing monitoring data for

those 55 days be counted in determining data completeness for 2009. EPA Regional

Administrator Shawn M. Garvin approved that request in a letter dated September 24, 2010.

DNREC’s data substitution analysis and EPA’s approval letter are attached.

B. Monitor Shutdowns

Philadelphia County

In Philadelphia County, monitors 42-101-0014 and 42-101-0136 were shut down in 2007. AMS

had askedEPA if it could discontinue some monitors. EPA advised AMS that monitor 42-101-

0024, located at Northeast Philadelphia Airport, was the high ozone site, and therefore it needed

to stay. The monitor at the AMS laboratory (monitor 42-101-0004) was a Photochemical

Assessment Monitoring Stations (PAMS) site, where ozone monitoring was required. Therefore,

that monitor also needed to remain in place. The Philadelphia Area had more ozOne sites then

what was minimally required. In addition, the ozone design values for both sites considered for

shutdown were below .085 ppm. Therefore, EPA approved the shutdowns of monitors 42-10 1-

0014 and 42-101-0 136 with the approval of AMS’s July 1, 2008 Annual Network Plan.

Atlantic County

New Jersey Department of Environmental Protection (NJDEP) operated a monitoring site (34-

00 1-0005) in Galloway Township, Atlantic County. A new monitoring site at the Visitor Center

ofthe Edwin B. Forsythe National Wildlife Refuge in Brigantine became available and NJDEP

started running an 03 analyzer at this new site (34-001-0006) in April of 2007. NJDEP operated

the site in Galloway Township and in Brigantine for several months to obtain overlapping ozone

data. NJDEP then shut down monitor 34-001-0005 in Galloway Township in mid November

2007 since the two sites were very close to each other and recorded similar values.

5.
Camden County

The NJDEP shut down monitor 34-007-0003 in Camden County in 2008. The Camden Lab

station, which had been in operation since 1968, was unexpectedly discontinued on September

29, 2008 due to lack of security at the station. The NJDEP in coordination with EPA is actively

pursuing the establishment of a new station in Camden.

Attachments:

- EPA AQS Quick Look Report (AMP45O), dated June 22, 2010, containing 2007- 2009

ozone air quality data for the Delaware, Maryland, and Pennsylvania portions of the

Philadelphia Area.

- EPA AQS Data Quality Indicator Report (AMP255), dated August 11, 2010, for 2009 for

the State of Delaware.

- EPA AQS Data Quality Indicator Report (AMP25 5), dated August 11, 2010, for 2009 for

the State of Maryland.

- EPA AQS Data Quality Indicator Report (AMP255), dated August 11, 2010, for 2009 for

the Commonwealth of Pennsylvania.

- EPA AQS Quick Look Report (AMP45O), dated June 28, 2010, containing 2007- 2009

ozone air quality data for the New Jersey portions ofthe Philadelphia Area.

- May 17, 2010 EPA letter to AMS approving AMS ‘s March 29, 2010 Data Substitution

Analysis, submitted to EPA by letter dated April 9, 2010.

- AMS’s March 29, 2010 Data Substitution Analysis for AQS Site ID: 42-101-0024,

submitted via cover letter dated April 9, 2010.

- September 24, 2010 EPA letter to DNREC approving DNREC’s July 15, 2010 Data

Substitution Analysis, submitted to EPA by letter dated July 19, 2010.

- DNREC’s July 15, 2010 Data Substitution Analysis for Brandywine, AQS SitelO-003-1010,

submitted via cover letter dated July 19, 2010.

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