1 **UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION III**  **1650 Arch Street Philadelphia, Pennsylvania 19103**  **DATE:** November 3, 2011 **SUBJECT:** Technical Support Document for Notice of Proposed Rulemaking

– Approval and

Promulgation of Air Quality Implementation Plans; Maryland; Baltimore Nonattainment Area Determinations of Attainment of the 1997 Annual Fine Particulate Standard /s/ **FROM:** Ruth Knapp , E nvironmental P rotection S pecialist

Office of Air Program Planning **TO:** File

/s/ **THRU:** Cristina Fernandez

Director , Office of Air Program Planning

**A. BACKGROUND** On July 18, 1997 (62 FR 36852), EP A established a health - based fine particulate matter ( PM 2.5 ) National Ambient Air Quality Standard (NAAQS) at 15.0 micrograms per cubic meter (μg/m 3 ) based on a 3 - ye ar average of annual mean PM 2.5 concentrations, and a 24 - hour standard of 65 μg/m 3 based on a 3 - ye ar average of the 98 th percentile of 24 - hour concentrations. EPA established the standards based on significant evidence and numerous health studies demonstrating that serious health effects are associated with exposures to particulate matter. The process for designating areas following promulgation of a new or revised NAAQS is contained in 107(d)(1) of the C lean Air Act (C AA ) . EPA and s tate air quality agencies initiated monitoring for the 1997 PM 2.5 NAAQS in 1999 . On January 5, 2005 (70 FR 944) , EPA published its air quality designations and classifications for the 1997 PM 2.5 NAAQS based upon air quality monitoring data from those monitors for calendar years 2001 - 2003. These designations became effective on April 5, 2005. The Baltimore , Maryland area was designated nonattainment for the 1997 annual PM 2.5 NAAQS (see 40 CFR P art 81 .321 ).2

**B. EPA REQUIREMENTS PM**  **2.5 Attainment Requirements**  These designations triggered the C AA’s requirements under 172(c), which requires the submission of an attainment plan for each designated nonattainment area. EPA’s PM 2.5 implementation rule, published on April 25, 2007 (72 FR 20586) specifies that states must submit attainment plans for their nonattainment areas to EPA by no later than three years from the effective date of designation, that is, by April 5, 2008. EPA’s PM 2.5 implementation rule outlines the SIP requirements for the attainment plan, which includes among other things, the submission of an attainment demonstration showing the air quality i mprovements expected to result from national and local control measures, an analysis of reasonably available control measures (RACM), including all reasonably available control technology (RACT), reasonable further progress plan (RFP) , and contingency meas ures. EPA’s implementation rule also sets the attainment date in these areas as April 5, 2010, and the determination would be based on data from 2007 - 2009 (72 FR 20600). The s tate of Maryland is subject to these requirements since several counties are lo cated in PM 2.5 nonattainment area s . The Baltimore fine partic u l at e matter (PM 2.5 ) nonattainment area (hereafter referred to as “the Baltimore Area” or “Area” ) is composed of Anne Arundel County , Baltimore County , Harford County

, Howard County

, and the City of Baltimore . **D eterminations of Attainment**  Under EPA regulations at 40 CFR 50.7 , the annual primary and secondary

PM 2.5 standards are met when the annual arithmetic mean concentration, as determined in accordance with 40 CFR 50, a ppendix N, is less th an or equal to 15.0 ug/m 3

. D ata handling conventions and computations necessary for determining whether areas have met the PM 2.5 NAAQS, including requirements for data completeness, are listed in a ppendix N of 40 CFR 50. A year meets data completeness re quirements when at least 75 percent of the scheduled sampling day s for each quarter have valid data. The use of less than complete data is subject to the approval of EPA, which may consider f actors such as monitoring site closures/moves, monitoring dilige nce, and nearby concentrations in determining whether to use such data. If these proposed determinations of attainment are made final, the requirements for Mary land to submit an attainment demonstration and associated RACM, a RFP plan, contingency measures, and any other planning SIPs related to attainment of the 1997 annual PM 2.5 NAAQS within the Baltimore Area would be suspended until such time as: a) the Area is redesignated to attainment, at which time the requirements would no longer apply ; or, b) E PA determines that the Area has violated the annual PM 2.5 NAAQS, at which time, the Area would be required to submit such plans. See , 40 CFR 51.1004(c). Additionally , EPA will have met its statutory obligation3

pursuant to 179(c)(1) of the CAA to make a d etermination based on the Area’s air quality data as of the attainment date whether the Area attained the standard by that date. A determination of attainment does not shield an area from other required actions such as New Source Review (NSR), conformity and emission inventory requirements, and provisions to address pollution transport, which would require emission reductions at sources or other ty pes of emission activities contributing significantly to nonattainment in other areas or states, or interfering with maintenance in those areas. Determinations as to whether individual areas have attained the PM 2.5 standards and thus qualify for the application of a determination of attainment are being made in the context of rulemakings for individual areas. This Technical Support Document (TSD) provides an explanation of EPA’s analy sis used to determine whether the Baltimore Area has attained the annual PM 2.5 standard and whether it attained the standard by the applicable attainment date. **C. MONITORING**  **NETWORK** The Baltimore Area currently has seven monitors which can be used for comparison to the 1997 PM 2.5 annual NAAQS. The data from these monitors is discussed below in section D . One monitor located in the Area with site ID 24 - 510 - 0040 does not me et the criteria ( 40 CFR 58 subpart D 58.30) to be used for comparison to the annual standard and is therefore not included in this assessment. This area also has some co l located monitors which also are not comparable to the annual standard , but their data may be used to substitute for missing data at a primary monitor in some situations (See , 40 CFR 50 a ppendix N) . Finally , the monitor with site ID 24 - 510 - 0035 which was sometimes referred to as the FMC monitor had to be shut down in August 2008 due to demo lition occurring at the monitoring site. Based upon information provided by the Maryland Department of the Environment (MDE), EPA agreed with MDE that the remaining monitoring network adequately

reflects air quality

in the Area. T he monitoring site that was demolished was not the site of the maximum design value for the Area. Additional technical support explaining why data from this site is not needed to assess the attainment status of this area can be found in two documents provided by MDE to EPA. See the attached e - mail correspondence to this TSD for this information . **D . EPA’S ANALYSIS OF MONITORED DATA**  **Monitoring Data 2008**  **- 2010**  Inorder to demonstrate that the Area is attaining the annual 1997 PM 2.5 NAAQS and has clean data for purposes o f 40 CFR 5 1.1004(c) , air quality data from EPA’s Air Quality Sy stem (AQS) from calendar years 2008 - 2010 was reviewed. EPA’s determination that the Baltimore nonattainment area attains the annual 1997 PM 2.5 NAAQS is based upon quality- assured, qualityco ntrolled and state certified ambient air monitoring data for the 2008

–2010 period, as measured4

by Federal Reference Method (FRM), Federal Equivalent Method (FEM), or Approved Regional Method (ARM) monitors described in 40 CFR Part 50 Appendix N. The primary monitors used to determine the design value for the Baltimore, MD nonattainment area are listed in Table 1. The design value (DV) for each monitor is the 3 - ye ar average of annual mean PM 2.5 concentrations at the monitor , and is the value that would be compared to the 1997 PM 2.5 annual NAAQS. The DV for the area is the highest 3 - ye ar average of the annual means measured at all the monitors in the Area that meet the criteria to be used for comparison to the NAAQS. **Table 1. Baltimore Area 2008**  **- 201**  **0 PM**  **2.5 Data**  **( in**  **μg/m 3**  **)** City Site ID 200 8 Annual Mean 200 9 Annual

Mean 20 10 Annual

Mean 2008 - 2010

Design Value Glen Burnie 24 - 003 - 1003 12. 6 11.1 11.0 11.6 Padonia 24 - 005 - 1007 11.9 10.2 10. 4 10.8 Essex 24 - 005 - 3001 12.6 1 1 . 0 11. 6 11.7 Edgewood 24 - 025 - 1 001 11. 3 9. 6 9.5 10.1 Baltimore 24 - 510 - 0006 12. 2 10. 1 10. 1 10.8 Baltimore 24 - 510 - 0007 12. 4 10.3 10. 3 11.0 Baltimore 24 - 510 - 0008 12. 7 11. 1 11.0 11.6 According to AQS, monitoring site ID 24 - 003 - 0008 had some missing data for one quarter of 2010 . Howeve r, data from a collocated monitor was substituted for the missing data in accordance with 40 CFR 50 appendix N (Interpretation of National Ambient Air Quality Standards For PM 2.5 ). S ee , section 3.0 of the “ Guideline on Data Handling Conventions for the PM NAAQS”, EPA - 454/R - 99 - 008 ( April 1999 ) . A copy of th is guid e line is included as one of the attachments to this TSD along with the AQS data report. The values from the collocated monitor are reflected in the annual 2010 mean value provided in AQS. The DV for the Baltimore Area for 2008 - 2010 is 11.7 ug/m 3 and is below 15.0 ug/m 3 . Therefore, the Area is attaining the annual PM 2.5 NAAQS based on the most recent complete, qualityassured and state certified data available. **Monitoring Data 200 7**  **- 200**  **9** Inorder to determine that the Baltimore Ar ea attained the annual 1997 PM 2.5 NAAQS by its attainment date of April 5, 2010 , quality- assured, quality- controlled and state certified ambient air monitoring data for the 200 7

–2 00 9 period, as measured by FRM, FE M, or ARM monitors described in 40 CFR 50 a ppendix N was reviewed. This data is in Table 2. **Table 2**  **. Baltimore**  **Area 2007**  **- 2009**  **PM 2.5**  **Data (**  **in μg/m**  **3 )**  City Site ID 200 7 Annual Mean 200 8 Annual

Mean 20 09 Annual

Mean 2007 - 2009

Design Value Glen Burnie 24 - 003 - 1003 13.4 12. 6 11.1 12.45

Padonia 24 - 005 - 1007 13. 3 11.9 10.2 11.8 Essex 24 - 005 - 3001 14.0 12.6 1 1 . 0 12.6 Edgewood 24 - 025 - 1001 12. 2 11. 3 9. 6 11.0 Baltimore 24 - 510 - 0035 14.1 * * * Baltimore 24 - 510 - 0006 13. 1 12. 2 10. 1 11.8 Baltimore 24 - 510 - 0007 13 . 4 12. 4 10.3 12.0 Baltimore 24 - 510 - 0008 1 5 . 0 12. 7 11. 1 12.9 *Monitor Site ID 24 - 510 - 0035 shut down in August 2008 due to demoli ti on of the monitoring site. Air Quality

Data from site ID 24 - 003 - 1003 had some missing data for one quarter in 2007 . In ord er to assess if this monitor attained the standard, the max imum quarter substitution test as explained in the “Guideline on Data Handling Conventions for the PM NAAQS”, EPA - 454/R 99 - 008 ( April 1999 ) was applied. Basically , the test requires replacing the m issing data with the maximum concentration recorded at the site during the same quarter over the 3 - ye ar period in question, provided that the following criteria are met. The site must have valid data for at least 50 percent of the scheduled number of samp les for each quarter for all three years, and the emissions and meteorology for the quarters to be substituted must be comparable to the emissions and meteorology for the quarters in question. Air quality data from site ID 24 - 003 - 1003 met the criteria and the site also attained the standard for 2007 - 2009 using this test. The DV for the Baltimore Area for 200 7 - 20 09 is 1 2 . 9 ug/m 3 and is below 15.0 ug/m 3 . Therefore, the Area attained the annual PM 2 .5 NAAQS by its applicable attainment date based on quali tyassured and state certified data. **Preliminary Monitoring Data for 2011** Preliminary

data available to date for 2011 when considered in conjunction with data from 2009 and 2010 indicates that the Baltimore Area continues to attain the standard. The 2011 data is not complete and has not yet been quality- assured or certified but is provided below . **Table 3.**  **Baltimore Area**  **Preliminary 2011 PM**  **2.5 Data**  **( in**  **μg/m 3**  **)** City Site ID 20 11 Preliminary Annual Mean Glen Burnie 24 - 003 - 1003 10.5 Padonia 24 - 005 - 1007 9.9 Essex 24 - 005 - 3001 10.6 Edgewood 24 - 025 - 1001 9.3 Baltimore 24 - 510 - 0006 9.9 Baltimore 24 - 510 - 0007 9.5 Baltimore 24 - 510 - 0008 10.86

**RECOMMENDED AGENCY ACTION** Based on quality- assured, quality- controlled, and state certified ambient air monitoring data from 2008 - 2010 from the Baltimore Area, EPA is making the determination that the Area attains the annual 1997 PM 2.5 NAAQS. Preliminary data from 2011 indicates that the Area continues to attain the NAAQS. Therefore , EPA is suspending the attainment - related SIP requirements for the annual 1997 PM 2.5 NAAQS pursuant to 40 CFR 51.1004(c) . Also, b ased on the qualityassured, quality- controlled, and state certified ambient air monitoring data from 2007 - 2009 for the Baltimore Area, EPA is makin g the determination that the Are a attained the annual 1997 PM 2.5 standard by

its attainment date of April 5, 2010. The following four attachments are included with this TSD: EPA AQS Quick L ook Report (AMP480) dated October 20, 2011 Guideline on Data Handling Conventions for the PM NAAQS, EPA - 454/R - 99 - 008 (April 1999) E - mail Correspondence from MDE to EPA dated 8/14/2008 Notification of Closing of FMC Site E - mail Correspondence from MDE to EPA dated 8/18/2008 Network Analy sis of FMC Closure