UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION III 1650 Arch Street Philadelphia, Pennsylvania 19103

DATE: March 18, 2015

SUBJECT: Technical Support Document Regarding Monitoring Data

– Pennsylvania;

Determination of Attainment of the 2006 24

- hour Fine Particulate Standards for the Liberty

- Clairton Nonattainment Area

FROM: Emlyn Vélez

- Rosa, Environmental Engineer \ s \ 3/17/2015

Office of Air Program Planning

Loretta Hyden, Environmental Engineer \ s \ 3/1 8 /2015 Office of Air Monitoring & Analysis

TO: File

- Part 52 SIP Action

- Docke t ID No. EPA

- R03

- OAR

- 2015

- 0175

THRU: Marilyn Powers, Acting Associate Director \ s \ 3/17/2015

Office of Air Program Planning

I. INTRODUCTION

This document provides a technical review of the air quality monitoring data used to support the Environmental Protection Agency’s (EPA’s) proposed determination that the Liberty

Clairton, PA 24

- hour fine particulate (PM 2.5 ) nonattainment area (the Liberty

- Clairton Area) has attained the 2006 24

- hour PM 2.5 national ambient air quality standard (NAAQS).

I I . BACKGROUND

On July 16, 1997, EPA established an annual PM 2.5 NAAQS at 15.0 micrograms per cubic meter (μg/m 3 ) (hereafter referred to as “the 1 997 annual PM 2.5 NAAQS”), based on a 3

- year average of annual mean PM 2.5 concentrations (62 FR 38652, July 18, 1997). See 40 CFR 50.7. On September 21, 2006, EPA promulgated a new 24

- hour standard of 35 μg/m 3 based on a 3

- year average of the 98th percent ile of 24

- hour concentrations (71 FR 61144, October 17, 2006). The revised 2006 24

- hour PM 2.5 standard (hereafter “the 2006 24

- hour PM 2.5 NAAQS”) became effective on December 18, 2006. See 40 CFR 50.13

.2

The process for designating areas following promulgation of a new or revised NAAQS is contained in 107(d)(1) of the Clean Air Act (CAA). On January 5, 2005 (70 FR 944), EPA published its nonattainment area designations for the 1997 annual PM 2.5 NAAQS base d upon air quality monitoring data for calendar years 2001

- 2003. On November 13, 2009, EPA published designations for the 2006 24

- hour PM 2.5 NAAQS (74 FR 58688), which became effective on December 14, 2009. I n both action s , EPA designated the Liberty

- Cla irton Area as nonattainment for the 1997 annual and 2006 24

- hour PM 2.5 NAAQS , respectively

. The Liberty

- Clairton Area is comprised of the following portion of Allegheny County: the boroughs of Lincoln, Glassport, Liberty, and Port Vue and the City of Cla irton. See 40 CFR 81.339 (Pennsylvania). The Liberty

Clairton Area is surrounded by, but separate and distinct from the Pittsburgh

- Beaver Valley
PM 2.5 nonattainment area.

A nonattainment designation under the CAA triggers additional planning requirement s for states to show attainment of the NAAQS in the nonattainment areas by a statutory attainment date, as specified in the CAA. S ince 2005, EPA had implemented the 1997 and 2006 PM 2.5 NAAQS based on the general implementation provisions of subpart 1 of P art D of Title I of the CAA (subpart 1). On January 4, 2013, in N atural R esources D efense C ouncil v. EPA (NRDC v. EPA)

, the D.C. Circuit determined that EPA should be implementing its PM 2.5 pollution standard under additional CAA requirements than those EPA had been following in subpart 1 and remanded to EPA the “Final Clean Air Fine Particle Implementation Rule” (1997 PM 2.5 Implementation Rule) (72 FR 20586, April 25, 2007) and the “Implementation of the New Source Review (NS R) Program for Particulate Matter Less than 2.5 Micrometers (PM 2.5 )” final rule (2008 NSR PM 2.5 Rule). 1 706 F.3d 428 (D.C. Cir. 2013). The D.C. Circuit found that the EPA erred in implementing the 1997 PM 2.5 NAAQS solely pursuant to subpart 1, without consideration of the particulate matter specific provisions of subpart 4 of Part D of Title I of the CAA (subpart 4).

While the regulatory provisions of EPA’s 1997 PM 2.5 Implementation Rule do not explicitly apply to the 2006 24

- hour PM 2.5 NAAQS, EPA’s underlying statutory interpretation has been the same for both standards. On March 2, 2012, EPA provided implementation guidance for the 2006 24

- hour PM 2.5 NAAQS which reaffirmed and continued the framework and policy approaches of the 1997 Implementation PM 2.5 Rule

. 2 Thus, EPA believes that the statutory provisions of subpart 4 are also applicable to the 2006 24

- hour PM 2.5 NAAQS.

1 EPA’s 2008 NSR PM 2.5 Rule relates to requirements for the NSR permitting program required by parts C and D of title I of the CAA. The details and provisions of the 2008 NSR PM 2.5 Rule are not relevant to this proposed rulemaking.

2 EPA subsequently withdrew the implementa tion guidance on June 6, 2013 subsequent to the D.C. Circuit’s decision in NRDC v. EPA . EPA’s June 6, 2013 withdrawal memorandum is available at http://www.epa.gov/ttn/naaqs/pm/pdfs/implementationguidancewithdrawmemo.pdf

.3

Among other things, subpart 4 require s EPA to classify nonattainment areas for the PM 2.5 NAAQS based on the severity of their pollution problem. O n April 25, 2014, subsequent to the January 4, 2013 Court decision, EPA finalized a rule identifying the classification of all PM 2.5 areas currently designated nonattainment for the 1997 and 200 6 PM 2.5 NAAQS as “Moderate,” consistent with subpart 4 of the CAA. See 79 FR 31566 (June 2, 2014). Consequently, the Liberty

- Clairton Area was classified as Moderate for the 2006 24

- hour PM 2.5 NAAQS.

Under section 188(c)(1) of the CAA, a moderate nonatt ainment area shall attain the PM 2.5 NAAQS as expeditiously as practicable but no later than the end of the sixth calendar year after the area’s designation to nonattainment. Because the designation of nonattainment areas for the
2006 24

- hour PM 2.5 NAAQS became effective on December 14, 2009, the presumptive sixth year attainment date for most moderate nonattainment areas would be no later than December 2015. Under EPA’s longstanding Clean Data Policy interpretation, a determination that a nonattai nment area has attained the NAAQS prior its statutory applicable attainment date suspends the s tate’s obligation to submit attainment

- related planning requirements of the CAA for so long as the area continues to attain the standard

. 3 These include require ments to submit an attainment demonstration, reasonable further progress ( RFP )

, reasonably available control measures ( RACM )

, and contingency measures, because the purpose of these provisions is to help reach attainment, a goal which has already been achie ved. To determine attainment, EPA commonly uses three calendar years of complete air quality monitoring data for the nonattainment area.

I I I. EPA ’s REQUIREMENTS

A. Monitoring Network

An adequate monitoring network for PM 2.5 should satisfy the specific minimum criteria for establishing state and local air monitoring stations for PM 2.5 data collection, as described in 40 CFR part 58, appendix D, section 4.7. Additionally, the monitoring network in place should be consistent with the most recent annual monitoring network plan submitted by the State or local agency and approved by EPA. See 40 CFR 58.10. For comparison with the PM 2.5 NAAQS , o nly air quality data measured by a Federal Reference Method (FRM) , a Federal Equivalent Method

3 For an EPA memorandum discussing interpretation that three years of data showing attainment of a NAAQS suspends requirements to submit certain attainment plan SIP requirements including those in section 172 of the CAA, see Reasonable Further Progress, Atta inment Demonstration, and Related Requirements for Ozone Nonattainment Areas Meeting the Ozone National Ambient Air Quality Standard, EPA Memorandum from John S. Seitz, Director, Office of Air Quality Planning Standards, May 10, 1995 (Seitz Memorandum), lo cated at http://www.epa.gov/ttn/caaa/t1/memoranda/clean15.pdf

.4

(FEM) , or an Approved Regional Method (ARM) , in accordance with 40 CFR part 53 or part 58 shall be used.

B

. Monitoring Data

Under EPA regulations at 40 CFR 50.13(c), the 2006 24

- hour primary and secondary PM 2.5 NAAQS are met when the 98 th percentile 24

- hour concen tration, as determined in accordance with 40 CFR part 50, appendix N, is less than or equal to 35 ug/m 3

. Data handling conventions and computations necessary for determining whether areas have met the PM 2.5 NAAQS, including requirements for data completen ess, are also provided in 40 CFR part 50, appendix N. Specifically, the 2006 24

- hour PM 2.5 NAAQS is met when the 24

- hour design value at each monitoring site is less than or equal to 35 μg/m 3

. The comparison of the 24

- hour design value to the 2006 24

- hour PM 2.5 NAAQS shall be based on 3 consecutive, complete years of air quality data.

Three years of valid annual 98 th percentile PM 2.5 mass concentrations are required to produce a valid 24

- hour PM 2.5 design value. The 9 8 th percentile is defined as the daily value out of a year of PM 2.5 monitoring data below which 98 percent of all daily values fall. A year meets data completeness requirements when at least 75 percent of the scheduled sampling days for each quarter have valid data. Ho wever, years shall be considered valid, notwithstanding quarters with less than complete data (even quarters with less than 11 samples), if the resulting annual 98 th percentile value or resulting 24

- hour standard design value is greater than the level of t he standard. The use of less than complete data is subject to the approval of EPA which may consider factors such as monitoring site closures/moves, monitoring diligence, and nearby concentrations in determining whether to use such data for comparisons to the 2006 24

- hour
PM 2.5 NAAQS.

A ll valid FRM/FEM/ARM PM 2.5 mass concentration data produced by suitable monitors are required to be submitted to EPA’s Air Quality System (AQS) in μg/m 3 and must be used in the design value calculations. Generally, EPA will only use such data if they have been certifie d by the reporting organization. When the data for a particular monitoring si te and year meet the data completeness requirements, the 98th percentile is calculat ed for each monitoring site by following the steps outlined in subsection 4.5 of 40 CFR part 50, appendix N . The 24

- hour design value is then calculat ed by averaging the annual 98 th percentiles for the 3

- year period. For the purposes of comparing the calculated 24

- hour design value to the applicab le level of the NAAQS ( 35 μg/m 3 ) , the final results of the 24

- hour design value calculations are rounded to the nearest 1 μg/m 3 ( that is, decimals 0.5 and greater are rounded up to the nearest whole number, and any decimal lower than 0.5 is rounded down to the nearest whole number). Results for all intermediate calculations must not be rounded.5

IV . EVALUATION OF AIR QUALITY MONITORING DATA

A. Monitoring Network Adequacy

Allegheny County Health Department (ACHD) maintains and operates a total of two PM 2.5 monitoring sites in t he Liberty

- Clairton Area, whose data met the requirements for use in determining attainment of the 2006 24

- hour PM 2.5 NAAQS. EPA has previously determined that the PM 2.5 monitoring network for the Li be rty

- Clairton Area is adequate. As documented, t he two monitors in the Liberty

- Clairton Area measure ambient air quality by following one of EPA’s approved FEM, FRM, or ARM, in accordance with 40 CFR part 53 and part 58. EPA found that the number of mon itors in the Liberty

- Clairton Area continues to meet the minimum regulatory requirements given in 40 CFR part 58, appendix D, section 4.7

. T he monitoring network in place is in accordance with Allegheny County ’s most recent annual monitoring network plan approved by EPA, as required by 40 CFR 58.10. 4

B . Certified Air Quality Monitoring Data , 2012

- 2014

ACHD submitted and certified quality

- assured air quality PM 2.5 monitoring data for the Liberty

Clairton Area into AQS. The 2012

- 2014 data recorded meets the completeness requirements of 40 CFR part 50, appendix N, thus allowing a valid design value calculation for each monitoring site for the 2012

- 2014 period. Attached to this document is a “Design Value Report” from AQS, containing daily PM 2.5 data for the Liberty

- Clairton Area for 2012

- 2014 , as summarized in Table 1

.

Table 1: 2012

- 20 14 Liberty

- Clairton Area Daily PM 2.5 Monitoring Data & Completeness

Monitor Name AQS Site ID Location 98 th Percentile 2012

- 2014 Design Value (μg/m 3 ) Complete

Data? 2012 2013 2014
Liberty 42

- 003

- 0064 Liberty Borough 42.5 31.1 32.2 35 Yes Clairton 42

- 003

- 3007 City of Clairton 19.2 17.1 31.2 23 Yes

Following the computation procedures of 40 CFR part 50, appendix N, t he design values for both monitors in the Liberty

- Clairton Area are 35 and 25 μg/m 3 , respectively, for the 2012

- 2014 monitoring period

. Consistent with EPA’ s requirements of 40 CFR 50, the monitors in the Liberty

- Clairton Area are showing attainment of the 2 006 PM 2.5 NAAQS, based on 2012

- 2014

4 The ACHD’s 2014 annual ambient monitoring network plan was approved by EPA in a November 21 , 2014 letter from Shawn M. Ga rvin, Regional Administrator, EPA Region III, to Jayme Graham

, Program Manager of the Allegheny County Health Department.6

quality

- assured and certified air quality data.

V . CONCLUSION

EPA has reviewed quality

- assured, quality

- controlled, and certified 20 12

- 2014 ambient air quality monitoring data for the Liberty

- Clairton Area. EPA finds that the Liberty

- Clairton A rea has attained the 2006 24

- hour PM 2.5 NAAQS , based on the most recent available PM 2.5 air quality data.

ATTACHMENT

- Appendix A: EPA AQS “ Design Value Report” (AMP480) dated February 3 , 201 5

, containing PM 2.5 air quality data for 20 12

- 201 4 f or the Liberty

- Clairton Area