Technical Support Document: EPA's Redesignation of the Canton, Ohio Area for the 2008 Lead National Ambient Air Quality Standard February 2023 U.S. Environmental Protection Agency ------- Table of Contents Section 1: Overview Section 2: Definitions S ecti on 3: B ackground 3.1 History of 2008 Pb NAAQS 3.2 History of 2008 Pb NAAQS Area Designations 3.3 History of 2008 Pb NAAQS Violations in Stark County Section 4: Technical Analysis 4.1 General Approach 4.2 Ambient Air Quality Monitors 4.3 Ambient Air Quality Monitoring Data 4.4 Violations based on Ambient Air Quality Monitoring Data in Stark County 4.5 Nonattainment Designation Boundary Determination 4.5.1 Factor 1: Air Quality in Potentially Included Versus Excluded Areas 4.5.2 Factor 2: Emissions in Areas Potentially Included Versus Excluded from the Nonattainment Area 4.5.3 Factor 3: Level of Control of Emissions Sources 4.5.4 Factor 4: Population Density and Degree of Urbanization including Commercial Development in Included Versus Excluded Areas 4.5.5 Factor 5: Expected Growth 4.5.6 Factor 6: Meteorology 4.5.7 Factor 7: Geography/topography 4.5.8 Factor 8: Jurisdictional Boundaries 4.5.9 Additional Information provided by the State 4.6 Summary of EPA's Assessment and Redesignation for the Canton, Ohio Area i ------- Tables Table 1: Summary of Area Monitoring Information, Current Area Designation, and EPA's Area Redesignation Table 2: Ambient Air Quality Monitoring Data for Stark and Columbiana Counties Table 3: Pb Design Values for Stark and Columbiana Counties Table 4 Sources of Pb Air Emissions Greater than 5.0 Pounds/year in Stark County, Ohio for 2016, 2017, 2018, and 2019 Table 5. Facilities Located in Counties Surrounding Stark County, Ohio with Pb Emissions Greater than 0.1 tons/year (200 lb) in 2017 Table 6. Population and Population Density Data for Canton and Stark County, Ohio Table 7. Change in Population and Population Density from 2010 to 2020 for Canton and Stark County, Ohio Figures Figure 1. Canton, Ohio Area showing the Pb Ambient Air Monitoring Site (AQS Site No. 39-151-0024) and Pb Emissions Sources > 0.50 tons per year in Stark County Figure 2: Republic Steel Pb Ambient Air Monitoring Site (AQS Site No. 39-151-0024), Three-Month Rolling Averages (2017 - 2021) Figure 3. Sources of Pb Emissions in Stark County, Ohio Area based on 2017 NEI Figure 4. Locations of Sources of Pb Emissions Greater than 0.1 tons/year in 2017 in Counties Surrounding Stark County, Ohio Figure 5. Wind Rose for North Canton, Stark County, Ohio Figure 6: Pollution Rose for Pb Concentrations from Republic Steel Ambient Air Monitoring Site (AQS Site No. 39-151-0024), Canton, Stark County, Ohio Figure 7. Polar Plot Map of Mean Pb Ambient Air Concentrations (October 2018 - December 2020) Figure 8. Boundaries of the Canton, Ohio Nonattainment Area for the 2008 Pb NAAQS li ------- Technical Support Document OHIO EPA's Redesignation of the Canton, Ohio Area for the 2008 Lead National Ambient Air Quality Standard 1. Overview On November 12, 2008, the EPA revised the National Ambient Air Quality Standard (NAAQS) for lead (Pb) (73 FR 66964). The EPA set the level for the primary (health-based) standard at 0.15 micrograms per cubic meter ((j,g/m3) and set the secondary (welfare-based) standard to be identical in all respects to the primary standard. 73 FR 66964 (November 12, 2008). Pursuant to section 107(d) of the Clean Air Act (CAA), EPA must designate as "nonattainment" those areas that violate the NAAQS and those nearby areas that contribute to violations. Once an area has been designated, the EPA Administrator, under CAA section 107(d)(3), "may at any time" notify a state that a designation should be revised. 42 U.S.C. § 7407(d). EPA designated all areas of the United States as "unclassifiable," "unclassifiable/attainment," or "nonattainment" for the 2008 Pb NAAQS in two rounds. The first round published in the Federal Register on November 16, 2010 (75 FR 71033), and the second round published on November 8, 2011 (76 FR 72097). In the November 8, 2011 action, Stark County, along with the remaining unmonitored areas of Ohio, was designated as unclassifiable/attainment because available information did not indicate that the air quality in this area exceeded the 2008 Pb NAAQS. Based on recent data from an ambient air quality monitoring site and EPA's technical analysis described below, Table 1 identifies portions of one county in Ohio that EPA is redesignating from "unclassifiable/attainment" to "nonattainment" for the 2008 Pb NAAQS. As explained in the technical analysis below, the nonattainment area addresses violations at the Republic Steel plant in Canton, Ohio and is smaller than the presumptive county-wide boundary in the 2008 Pb NAAQS final rule. Table 1. Summary of Area Monitoring Information, Current Area Designation, and EPA's Area Redesignation Area Con illy AQS II) 2019-2021 Design Value (Mg/iii') Current Designation Uedesignalion Canion, Ohio Slark (partial) 39-151-0024 0.40 Lnclassi liable. Attainment Nonallainmenl Figure 1 contains maps of Stark County and the Canton, Ohio area showing the location of the 1 ------- ambient air quality monitoring site with violations of the 2008 Pb NAAQS based on the 2019- 2021 design value and sources of Pb emissions greater than 0.50 tons per year (1,000 pounds per year) in Stark County. Figure 1. Canton, Ohio Area showing the Pb Ambient Air Monitoring Site (AQS Site No. 39-151-0024) and Pb Emissions Sources > 0.50 tons per year in Stark County Legend Violating Pb Monitor 39-151-0024 (2019-2021 Design Value) Perimeter of Pb Sources > 0.5 tons/year (2017 NEI), Republic Steel © Fulton Heights ¦ VASSAM PARK WESTBI ^ — - STARK COUNTY Tff Plain Twp ..t * J .... PLAIN A CITY FAIRMOUNT 'EST NEW HOPE Lynn Center Park "HincolnSti 2 ------- Section 107(d)(3) of the CAA identifies the schedule for the redesignation process. On April 26, 2022, EPA notified the Governor of the State of Ohio regarding our intended redesignation and established a 120-day period for the state to respond according to the provisions found in CAA section 107(d)(3)(B). On May 3, 2022, the EPA notified the public of the intended redesignation decision along with supporting documentation for Stark County, OH (87 FR 26147). At that time, the EPA also announced a 30-day public comment period that closed on June 2, 2022. Three public comments supporting EPA's intended redesignation were submitted to EPA's public docket for this redesignation action, Docket No. EPA-HQ-OAR-2022-0195, located at www.regulations.gov. On August 22, 2022, the Ohio Environmental Protection Agency (Ohio EPA) submitted a response to EPA's April 26, 2022 notification concurring with EPA's intended boundaries for the proposed nonattainment area. The EPA is therefore finalizing the redesignation without modification. The redesignation of the Canton, Ohio area to nonattainment for the 2008 Pb NAAQS imposes certain planning requirements on the State of Ohio to reduce Pb concentrations within this area. These include, but are not limited to, the requirement per CAA section 191(a) to submit, within 18 months of redesignation, a revision to the Ohio state implementation plan (SIP) that provides for attainment of the 2008 Pb NAAQS as expeditiously as practicable, but no later than 5 years after the date of redesignation to nonattainment, consistent with CAA section 192(a). 2. Definitions The following are definitions of important terms used in this document. 1) Designated "nonattainment" area - an area which EPA has determined, based on a state recommendation and/or technical analysis, does not meet the 2008 Pb NAAQS based on the most recent 3 years of quality-assured air quality monitoring data including at least one valid 3-month site mean above the level of the 2008 Pb NAAQS, or that contributes to a violation in a nearby area. 2) Designated "unclassifiable/attainment" area - an area which EPA has determined does not contribute to a violation of the 2008 Pb NAAQS in a nearby area and either: (1) meets the 2008 Pb NAAQS, based on the most recent 3 years of quality-assured air quality monitoring data including 36 consecutive valid 3-month site means, or (2) has no monitors or has incomplete air quality monitoring data but has no violations of the 2008 Pb NAAQS. 3) Designated "unclassifiable" area - an area which EPA has determined cannot be classified on the basis of available information as meeting or violating the 2008 Pb NAAQS, based on the most recent 3 years of quality-assured air quality monitoring data, but for which available monitoring data from the same or a recent period indicate a significant likelihood that the area may be violating the 2008 Pb NAAQS. 4) Violating monitor - an ambient air monitor whose valid design value exceeds 0.15 3 ------- [j,g/m3. As described in Appendix R of part 50 of Title 40 of the Code of Federal Regulations (CFR), a violation can be based on either Pb-TSP or Pb-PMio data, and only 3 months of data are necessary to produce a valid violating design value, where PMio is particulate matter less than 10 microns in diameter. 5) 1978 Pb NAAQS - 1.5 (J,g/m3, National Ambient Air Quality Standard for Pb promulgated in 1978. Based on Pb-TSP indicator and averaged over a calendar quarter. 6) 2008 Pb NAAQS - 0.15 (J,g/m3, National Ambient Air Quality Standard for Pb promulgated in 2008. Based on Pb-TSP indicator and a 3-month rolling average. Pb-PMio data may be used in limited instances, including to show nonattainment. 7) Design value - the site-level metric (i.e., statistic) that is compared to the NAAQS level to determine compliance; the design value for the Pb NAAQS is selected according to the procedures in 40 CFR part 50, Appendix R from among the valid 3-month Pb-TSP and Surrogate Pb-TSP (Pb-PMio) arithmetic mean concentration for the 38-month period consisting of the most recent 3-year calendar period plus two previous months (i.e., 36 3- month periods) using the last month of each 3-month period as the period of report. 3. Background 3.1. History of 2008 Pb NAAQS On October 15, 2008, EPA strengthened the NAAQS for Pb. The revised standard was lowered from the 1.5 [j,g/m3 set in 1978, to a level of 0.15 [j,g/m3 based on a 3-month averaging time. The EPA also established minimum ambient air monitoring requirements for source-oriented and population-oriented sampling for sources with Pb emissions greater than a 1.0 ton per year threshold. 43 FR 46246 (October 5, 1978); 73 FR 66964 (November 12, 2008). On December 14, 2010, EPA revised the Pb emissions threshold for source-oriented monitoring to 0.50 tons per year except for airports. 75 FR 81126 (December 27, 2010). On September 16, 2016, EPA announced its decision to retain, without revision, the 2008 Pb NAAQS, finding that the existing primary (health-based) standard provided health protection for at-risk groups, especially children, and the existing secondary (welfare-based) standard provides protection against adverse effects to public welfare, including harm to aquatic and terrestrial ecosystems. 81 FR 71906 (October 18, 2016). 3.2. History of 2008 Pb NAAQS Area Designations In November 2010, EPA completed an initial round of nonattainment designations for the 2008 Pb NAAQS. 75 FR 71033 (November 22, 2010). On November 8, 2011, EPA designated all remaining areas of the United States as meeting or not meeting the 2008 Pb NAAQS based on data from 2008-2010. In the November 8, 2011 action, Stark County, along with the remaining unmonitored areas of Ohio, was initially designated as unclassifiable/attainment because 4 ------- available information did not indicate that the air quality in this area exceeded the 2008 Pb NAAQS. 76 FR 72097 (November 22, 2011). 3.3 History of 2008 Pb NAAQS Violations in Stark County On June 6, 2017, an ambient air quality monitoring site began operating in Stark County to measure concentrations of Pb. The site is known as the Republic Steel ambient air monitoring site (AQS Site No. 39-151-0024) and is located at 3150 Georgetown Road NE, Canton, Ohio. The most recent certified, quality-assured air quality monitoring data collected at the Republic Steel ambient air monitoring site indicate that the 2019-2021 design value is 0.40 (J,g/m3, which exceeds and violates the 0.15 [j,g/m3 level of the 2008 Pb NAAQS. Ohio EPA's response to EPA's intended redesignation to nonattainment noted ongoing efforts to address violations of the 2008 Pb NAAQS, including pending enforcement actions and a July 2, 2021, Consent Order for Preliminary Injunction in the Stark County Court of Common Pleas, which mandated that Republic Steel facility undertake certain actions to reduce lead emissions. 4. Technical Analysis 4.1 General Approach This technical analysis for the Canton, Ohio area identifies a monitor in Stark County that violates the 2008 Pb NAAQS, evaluates sources and nearby counties contributing to Pb concentrations in the area, and determines the area boundaries for redesignation. To determine whether areas are in violation, the 2008 final rule for the Pb NAAQS adopted guidance (2008 EPA Pb Guidance) for using monitoring data from the 3 most recent calendar years to identify a violation. 73 FR 67033 (November 12, 2008). To determine the boundaries of an area where violations support a nonattainment designation, the 2008 EPA Pb Guidance states that the perimeter of a county containing the violating monitor is the initial presumptive boundary for nonattainment areas. If the boundaries are smaller than the full county, as here, that smaller boundary should be accompanied by a demonstration to show that violations are not occurring in the excluded portions of the county and that the excluded portions are not source areas that contribute to the observed violations. To justify establishing either a larger or smaller area than the presumptive boundary, the 2008 EPA Pb Guidance indicated the following eight factors should be considered (73 FR 67033 (November 12, 2008)): 1) Air quality in potentially included versus excluded areas; 2) Emissions in areas potentially included versus excluded from the nonattainment area; 3) Level of control of emissions sources; 4) Population density and degree of urbanization including commercial development in included versus excluded areas; 5 ------- 5) Expected growth of the population (including extent, pattern, and rate of growth); 6) Meteorology (weather/transport patterns); 7) Geography/topography (mountain ranges or other air basin boundaries); and 8) Jurisdictional boundaries (e.g., counties, air districts, reservations, etc.). In addition to an analysis of the eight factors above, states can choose to recommend Pb nonattainment boundaries by using any one, or a combination of, the following techniques (id.): • Qualitative analysis; • Spatial interpolation of air quality monitoring data; or • Air quality simulation by dispersion modeling. The EPA has looked to the 8 factors provided in the 2008 EPA Pb Guidance in this redesignation to nonattainment. In the technical analysis below, EPA evaluated the violating monitoring site, contributing sources, and area boundaries based on the weight of evidence of the factors listed above. The boundaries of the nonattainment area are smaller than the county boundary, as explained below. 4.2 Ambient Air Quality Monitors On June 6, 2017, an ambient air quality monitoring site was installed and began operating in Stark County to measure concentrations of Pb and other toxic metals. Ohio EPA, through its partnership with the Canton City Board of Health's Air Pollution Control Division,1 installed this special purpose monitor (SPM) to meet the requirements of a state permit2 issued on December 12, 2016, to Republic Steel as part of operational changes made to its plant at 2633 Eighth Street NE, Canton, Ohio 44704-2311 (Republic Steel). Republic Steel manufactures leaded steel and other steel products. The Republic Steel ambient air monitoring site (AQS Site No. 39-151-0024) is located at 3150 Georgetown Road NE, Canton, Ohio, which is near a residential area across the street from and south of the Republic Steel plant. In April 2019, Ohio EPA converted the designated primary Pb sampler at the Republic Steel ambient air monitoring site from an SPM to a State or Local Air Monitoring Station (SLAMS) monitor. The conversion was made as a result of Ohio EPA's 2017 emissions inventory, which indicated that Republic Steel's Pb emissions were at 0.81 tons per year. 40 CFR Part 58 Appendix D, Section 4.5(a) requires ambient air monitoring of Pb emissions around any non- airport facility that reports actual Pb emissions greater than 0.50 tons per year. The EPA requires SLAMS monitors to collect Pb samples at a minimum frequency of l-in-6 days and those data be reported to EPA's Air Quality System (AQS). On March 1, 2021, Ohio EPA began operating a second monitor at the Republic Steel ambient air monitoring site to collect additional Pb samples on a random day sampling schedule.3 Pb data 1 Canton City Board of Health, Air Pollution Control Division. https.V/www. cantonhealth. org/apc/ 2 Ohio EPA Air Pollution Permit-to-Install (PTI), Permit Number: P0121793, Facility ID: 1576050694, Republic Steel, http://wwwapp.epa.ohio.gov/dapc/permits_issued/1499790.pdf 3 2021-2022 Ohio EPA Air Monitoring Network Plan. https://epa. ohio.gov/static/Portals/27/ams/sites/2021-2022_AMNPMain Report_Final.pdf 6 ------- from both of these monitors are combined to calculate the monitoring site level design value for comparison to the NAAQS. Ohio EPA continued to also collect air samples to evaluate air quality specifically during leaded production at the Republic Steel plant. Because these air samplers were operated only during leaded production time periods, typically less than the routine 24-hour air samples required for air monitoring data used for NAAQS comparisons, the data are not reported to EPA's AQS. Ohio EPA posts data from all the Pb monitors on its website.4 The two ambient air quality monitors (Parameter Occurrence Code - POC 1, POC 4) at the Republic Steel monitoring site measure ambient concentrations on a microscale level of 0 to 100 meters with a staggered schedule. POC 1 operates on the EPA sampling schedule of l-in-6 days, and POC 4 operates on a randomized schedule. The POC is used to distinguish different instruments that measure the same parameter at the same monitoring site. The collection method uses Manual Equivalent Method EQL-0170-192: Heated Nitric Acid Block Digestion and Inductively Coupled Plasma / Mass Spectrometry (ICP/MS) Analysis for Lead (Pb) on total suspended particulate matter (TSP) High-Volume Filters. In this method, total suspended particulate matter is collected on glass fiber filters according to 40 CFR Appendix B to part 50, EPA Reference Method for the Determination of Suspended Particulate Matter in the Atmosphere (High-Volume Method), extracted with a solution of nitric acid, heated on a hot block to 95°C for one hour, and brought to a final volume of 50 milliliters (mL). The Pb content of the sample extract is analyzed by Inductively Coupled Plasma / Mass Spectrometry (ICP-MS) based on EPA Method 200.8 and SW-846 Method 6020A. Both POC 1 and POC 4 met quality assurance criteria to be deemed as valid and the requirements of 40 CFR Part 58 Appendix A5 and the Quality Assurance Handbook Volume II, Appendix D, Measurement Quality Objectives and Validation Templates.6 In April 2022, another ambient air quality monitoring site was installed at 719 Marietta Avenue NE, Canton, Ohio, and the Canton City Board of Health's Air Pollution Control Division began collecting data. This new "Republic Community" monitoring SLAMS site (AQS Site No. 39- 151-0025) operates two monitors denoted as POC 1 and 4 on the same schedule and days as the Republic Steel monitoring site (AQS Site No. 39-151-0024). Data are reported to EPA's AQS and are also available on Ohio EPA's website.7 4 Ohio EPA, Air Pollution Control, Reports & Data, Special Sampling Projects. https://epa.ohio.gov/wps/portal/gov/epa/divisions-and-offices/air-pollution-control/reports-and-data/special- sampling-projects 5 40 CFR Part 58, Appendix A, Quality Assurance Requirements for Monitors used in Evaluations of National Ambient Air Quality Standards https://www.ecfr.gov/current/title-40/chapter-I/subchapter-C/part-58/appendix- Appendix%20A%2 Oto % 2 0Part%2058 6 Quality Assurance Handbook Volume II, Appendix D, Measurement Quality Objectives and Validation Templates https://www.epa.gov/sites/default/files/2020- 10/documents/app_d_validation_template_version_03_2017_for_amtic_rev_l.pdf 7 Ohio EPA Special Sampling Projects, Republic Steel, Canton, Stark County. https://epa.ohio.gov/divisions-and-offices/air-pollution-control/reports-and-data/special-sampling-projects 7 ------- 4.3 Ambient Air Quality Monitoring Data Ambient air quality monitoring data for the Republic Steel ambient air monitoring site (AQS Site No. 39-151-0024) are reported in EPA's AQS. Both monitors POC 1 and POC 4 at the site were used in summary statistics of annual max 3-month rolling averages and design value calculations. Figure 2 shows the plot of AQS reported Pb concentrations as 3-month rolling averages at the Republic Steel ambient air monitoring site for 2017-2021 with violations above the 0.15 [j,g/m3 2008 Pb NAAQS noted in red. Figure 2. Republic Steel Pb Ambient Air Monitoring Site (AQS Site No. 39-151-0024), Three-Month Rolling Averages (2017 - 2021) Stark Lead Monitor Three-Month Rolling Averages (2017-2021) 0.45 0.40 a— 0.35 m 0.30 E Until April 2022 when the new Republic Community ambient air monitoring site (AQS Site No. 39-151-0025) was installed, the Republic Steel monitoring site (AQS Site No. 39-151-0024) was the only ambient air monitoring site for Pb in Stark County. The nearest downwind monitors for Pb are approximately 69 kilometers (km) east southeast of the Republic Steel ambient air monitoring site and located in Liverpool, Ohio in adjacent Columbiana County. No other air monitors for Pb are located in the counties adjacent to Stark County besides Columbiana County. Table 2 contains the annual maximum Pb 3-month rolling averages for the ambient air monitors in Stark and Columbiana Counties for 2016-2022. Table 2. Ambient Air Quality Monitoring Data for Stark and Columbiana Counties 8 ------- Con illy Monitor N si mc Monitor AQS II) Monitor l.ocsition Msixiimim PhS-Monlh Rolling Avi'rsigi'" (UU ill') (Number of Complete Months in Parentheses) 2016 2017 20 IS 2019 2020 2021 2022 Stark Republic Steel 39-151- 0024 3150 George- town Road NE, Canton, Ohio N/A 0.11 (5) 0.20 (12) 0.21 (12) 0.13 (12) 0.40 (11) 0.07 (6) Stark Republic Community 39-151- 0025 719 Marietta NE, Canton, Ohio N/A N/A N/A N/A N/A N/A N/A Columbiana Columbiana Port Authority 39-029- 0019 1250 George Street, East Liverpoo 1, Ohio 0.02 (12) 0.02 (12) 0.02 (12) 0.01 (12) 0.01 (8) 0.01 (12) 0.01 (3) Columbiana Eastside Elementary 39-029- 0023 500 Mary lan d Avenue, East Liverpoo 1, Ohio 0.01 (9) 0.01 (12) 0.03 (12) 0.01 (12) 0.01 (8) 0.01 (12) 0.01 (6) Columbiana East Liverpool WTP 39-029- 0020 2220 Michigan Avenue, East Liverpoo 1, Ohio 0.01 (12) 0.01 (12) 0.01 (12) 0.01 (12) 0.01 (8) 0.01 (12) 0.00 (6) * Information on the am )ient air quality monitors and c ata used to calculate t le Pb rolling averages is publicly available at: https://www.epa.gov/aqs The Pb design values for Stark County and surrounding area were calculated based on the most recent quality-assured and certified AQS ambient air quality monitoring data for 2016-2018, 2017-2019, 2018-2020, and 2019-2021 as shown in Table 3. The design values were calculated according to the data handling procedures in 40 CFR part 50, Appendix R, and are valid for comparison to the NAAQS. 9 ------- Table 3. Pb Design Values for Stark and Columbiana Counties Con illy Monitor Name Monitor AQS II) Monitor Location Pb Design \ aliie- (iig/m') 2016- 20 IS 2017- 2019 2018- 2020 2019- 2021 Stark Republic Steel 39-151-0024 3150 Georgetown Road NE, Canton, Ohio 0.20 0.21 0.21 0.40 Stark Republic Community 39-151-0025 719 Marietta NE, Canton, Ohio N/A N/A N/A N/A Columbiana Columbiana Port Authority** 39-029-0019 1250 George Street, East Liverpool, Ohio 0.02 0.02 0.02 0.01 Columbiana Eastside Elementary ** 39-029-0023 500 Maryland Avenue, East Liverpool, Ohio 0.03 0.03 0.03 0.01 Columbiana East Liverpool WTP** 39-029-0020 2220 Michigan Avenue, East Liverpool, Ohio 0.01 0.01 0.01 0.01 Information on the ambient air quality monitors and data used to calculate the Pb design values is publicly available at https://www.epa.gov/aqs. Some Columbiana County design values are incomplete due to site establishment dates and COVID-19 restrictions. 4.4 Violations based on Ambient Air Quality Monitoring Data in Stark County A monitor's design value indicates whether that monitor attains a specified air quality standard. Procedures for using monitored air quality data to determine whether the monitor attains or violates the 2008 Pb NAAQS are given in 40 CFR part 50, Appendix R. The 2008 Pb NAAQS are met at a monitoring site when the identified design value is valid and less than or equal to 0.15 [j,g/m3. A Pb design value that meets the NAAQS is generally considered valid if it encompasses 36 consecutive valid 3-month site means (specifically for a 3-year calendar period and the two previous months). For this purpose, a 3-month site mean is valid if valid data were obtained for at least 75 percent of the scheduled monitoring days in the 3-month period. A Pb design value that does not meet the NAAQS is considered valid if at least one 3-month mean that meets the same 75 percent requirement is above the NAAQS. That is, a site does not have to monitor for 3 full calendar years to have a valid violating design value; a site could monitor just 3 months and still produce a valid (violating) design value. EPA considered the Pb NAAQS design value for the Republic Steel ambient air monitoring site in Stark County (AQS Site No. 39-151-0024) by assessing the most recent 3 consecutive years (i.e., 2019-2021) and two previous months of quality-assured, certified ambient air quality data in EPA's AQS using data from Federal Reference Method and/or Federal Equivalent Method 10 ------- monitors that are sited and operated in accordance with 40 CFR parts 50 and 58. Data collected at the Republic Steel monitoring site (AQS Site No. 39-151-0024) indicate that the 2019-2021 design value representative of the Stark County area is 0.40 [j,g/m3. With a design value of 0.40 (J,g/m3, the Republic Steel ambient air monitoring site shows a violation for 2019- 2021 of the 2008 Pb NAAQS of 0.15 ^g/m3. 4.5 Nonattainment Redesignation Boundary Determination Under CAA section 107(d)(3), the EPA Administrator may at any time notify the Governor of any State that available information—including air quality data, planning and control considerations, and any other air quality-related considerations the Administrator deems appropriate—indicates that the designation of any area or portion of an area within the State should be revised. Air quality data from 2019-2021 indicate that ambient lead concentrations in Stark County do not meet the NAAQS, and, therefore, it is appropriate to redesignate to nonattainment some area in Stark County and possibly additional areas in surrounding counties. The absence of monitors indicating violations in nearby counties is not a sufficient reason to eliminate nearby counties as candidates for nonattainment status. A nonattainment area should contain the area violating the NAAQS (e.g., the area around a violating monitor or encompassing modeled violations), as well as any nearby areas (e.g., counties or portions thereof) that contain emissions sources contributing to the violation. See CAA section 107(d)(1). EPA has also looked to the guidance used in the initial area designations process to inform the boundaries of the new nonattainment area. Accordingly, EPA conducted an evaluation of the eight factors listed above to determine the geographic scope of the nonattainment boundary. In the sections below, we consider the appropriate geographical extent of the nonattainment area. 4.5.1 Factor 1: Air Quality in Potentially Included Versus Excluded Areas This factor considers the Pb design values (in (J,g/m3) for the ambient air quality monitors in Stark County and the surrounding area based on data for the 2019-2021 period. Ambient air quality data are discussed above in section 4.3. The Republic Steel and Republic Community ambient air monitors (AQS Site Nos. 39-151-0024, 39-151-0025) are the only ambient air monitors for Pb in Stark County. The nearest downwind ambient air monitors reporting Pb data to EPA's AQS are approximately 69 km east southeast of the Republic Steel ambient air monitoring site in adjacent Columbiana County, Ohio. The three Columbiana County ambient air monitors are all located in Liverpool, Ohio on the border of West Virginia and Pennsylvania, and 11 km west and upwind of the Lower Beaver Valley, Pennsylvania 2008 Pb Nonattainment Area, which was designated in 2010.8 As shown in Table 3, the 2019-2021 design values for the three Liverpool ambient air monitors meet the 2008 Pb 8 75 FR 71033 (November 22, 2010) https://www.govinfo.gov/content/pkg/FR-2010-ll-22/pdf/2010- 29405.pdfipage=1 11 ------- NAAQS. There are no other ambient air monitors for Pb in the counties surrounding Stark County. The absence of monitors is consistent with emissions reported in the 2017 National Emissions Inventory (NEI) discussed under Section 4.5.2 below, which indicates there are no other sources with actual Pb emissions greater than 0.50 tons per year that warranted a source-oriented monitor under 40 CFR Part 58 Appendix D, Section 4.5(a). See Table 5 below. 4.5.2 Factor 2: Emissions in Areas Potentially Included Versus Excluded from the Nonattainment Area Evidence of Pb emissions sources in the vicinity of a violating monitor is an important factor in determining whether a nearby area is contributing to a monitored violation. For this factor, EPA evaluates county-level emissions data for Pb and growth in Pb emitting activities. Figure 3 is a map of Stark County, Ohio and surrounding areas that shows all sources of Pb emissions listed in the 2017 NEI (January 2021 version). The January 2021 version of the 2017 NEI was the most current version of the national inventory available in 2022 when these data were compiled for the redesignation process. Sources with Pb emissions greater than 5 pounds per year are labeled. 12 ------- Figure 3. Sources of Pb Emissions in Stark County, Ohio Area based on 2017 NEI9 Sources > 5 lb Pb/vear Table 4 lists sources located in Stark County depicted in Figure 3 with emissions of Pb greater than 5 pounds per year for 2016, 2017, 2018, and 2019. Emissions data were derived from the 2017 NEI and Ohio EPA's Emission Inventory System (EIS) for 2016, 2018, and 2019. Table 4. Sources of Pb Air Emissions Greater than 5.0 Pounds/year in Stark County, Ohio for 2016, 2017, 2018, and 2019 Facility Address Facility Type Pb Emissions (pounds) 2016* 2017** 2018* 2019* Republic Steel Plant 2633 Eighth Street ME, Canton, OH Steel Mill 722.4 1620.5 1324.6 1423.6 United Rolls, Inc. 1400 Grace Avenue, NE, Canton, OH 90.0 122.1 123.2 123.8 Barber/Alliance Alliance, OH Airport*** 52.6 Timkensteel Corporation - 1835 Dueber Avenue, SW, Steel Mill 35.4 48.6 39.8 26.4 ® Source: https://enviro.epa.go\t/enviro/nei.htm?pType=FACILITY&pYear=2017&pN/ho=NEI&pState=&pState=39&pP ollutant=&pPolIutant— 743992l&pReport=coimty&pCoimty=&pTier=&pSector= 13 ------- Harrison Steel Canton, OH Plant Marathon 2408 Petroleum 27.0 37.7 33.8 31.2 Petroleum Gambrinus Refinery Company LP - Avenue SW, Canton Canton, OH Refinery Beach City Beach City, OH Airport*** 33.8 Tim ken steel 1835 Dueber Steel Mill 18.4 32.6 36.4 26.4 Corporation - Faircrest Steel Avenue, SW, Canton, OH Plant Minerva Minerva, OH Airport*** 17.2 Sunset Strip Marlboro, OH Airport*** 15.5 Yoder Louisville, OH Airport*** 11.6 Ironrock 1201 Millerton Brick, 7.0 6.6 6.6 7.4 Capital, Inc. Road SE, Canton, OH Structural Clay, or Clay Ceramics Plant ** *** Source: Ohio EPA, Emissions Inventory System, https://epa.ohio.gov/divisions-and- offices air-pollution-control reports-and-data download-eis-data-and-reports Source: 2017 NEI, https://www.epa.gov/air-emissions-inventories/2017-national- emissions-inventory-nei-data Emissions data for airport sources (there are approximately 20,000 airport facilities in the U.S. at which leaded aviation gasoline is consumed) were derived from the 2017 NEI. EPA recognizes that we have no information on emissions changes that may have occurred at airport sources since 2017. Of the sources listed in Table 4, the predominant source, and only source with Pb emissions greater than 0.1 tons per year (i.e., greater than 200 pounds/year), is Republic Steel's plant at 2633 Eighth Street NE, Canton, Ohio 44704-2311. This plant accounted for 80% of the 2017 total Pb emissions from all the sources in Stark County that were reported in the 2017 NEI. To evaluate growth in Pb emitting activities, EPA considered annual emissions from the sources in Table 4 from 2016 to 2020. The Pb air emissions from the Republic Steel plant have increased since 2016 from 722.4 lb to 1423.6 lb in 2019. As noted in Section 4.2 above, on December 12, 2016, Ohio EPA issued a Permit-to-Install to Republic Steel to make operational changes to its plant at 2633 Eighth Street NE, Canton, Ohio. In addition to sources in Stark County, EPA also evaluated potentially contributing sources in counties around Stark County. Table 5 shows sources located in the counties surrounding Stark County that emitted greater than 0.1 tons of Pb based on emissions data derived from the 2017 NEI. As described in EPA's 2008 "Proposed Lead NAAQS Regulatory Impact Analysis," Pb particles in the air tend to deposit rapidly with distance from the source according to their particle size and weight, and lead air concentrations in some cases can display significant 14 ------- gradients with distance from a source-oriented monitor.10 As discussed more fully below in Section 4.5.6, a polar plot centered on the Republic Steel ambient air monitor shows the Pb concentrations reach as low as nearly 0.0 [j,g/m3 within the windspeed variability a few blocks from the Republic Steel parcel, indicating that the majority of Pb detected at the Republic Steel ambient air monitoring site is coming only from the Republic Steel plant. Located several kilometers outside the Republic Steel parcel, the sources in Table 5 are not anticipated to be contributing to violations of the 2008 Pb NAAQS at the Republic Steel ambient air monitoring site. Figure 4 is a map of counties surrounding Stark County and the locations of sources listed in Table 5. Table 5. Facilities Located in Counties Surrounding Stark County, Ohio with Pb Emissions Greater than 0.1 tons/year (200 lbs) in 2017 Cou illy l-'acilitv City l-'acility Type Approximate Distance from Monitoring Site (km) 2017 m:i Pb Kmissions (lbs) Wayne Wayne County Wooster Airport 50 482.4 Mahoning Vallourec Star, LP Youngstown Steel Mill 66 471.8 Medina Weltzien Skypark Wadsworth Airport 42 437.9 Medina Medina Municipal Medina Airport 51 436.6 Tuscarawas Dover Municipal Light Plant Dover Electricity Generation 34 434.0 Summit Kent State University Kent Airport 39 393.7 Summit City of Akron Steam Generating Akron Steam / Heating Facility 35 380 Tuscarawas Harry Clever Field New Philadelphia Airport 37 301.5 Summit Akron-Canton Regional Akron Airport 16 271.5 Mahoning Youngstown Elser Metro Youngstown Airport 58 259.9 10 "Proposed Lead NAAQS Regulatory Impact Analysis" U.S. EPA Office of Air Quality Planning and Standards (June 2008). Section 2.2 Air Quality Modeling on page 2-5 states, "This may be particularly true for Pb as metals tend to deposit rapidly with distance from the source according to their particle size and weight." Section 5.5 Radius Method on page 5-18 states, "[L]ead air concentrations can in some cases display significant gradients with distance from a source-oriented monitor." https://www3.epa.gov/ttnecasl/regdata/RJAs/pb_ria_6-25-08_proposal.pdf 15 ------- Figure 4. Locations of Sources of Pb Emissions Greater than 0.1 tons/year in 2017 in Counties Surrounding Stark County, Ohio Star* County Kent State University Airport Vallourec Star, LP Steel Mill Medina Municipal Airport City of Akron Steam Generating Youngstown Elser Metro Airport Weltzien Skypark Airport Akron-Canton Regional Airport Republic Steel Ambient Air Monitor Wayne County Airport Dover Municipal Light Harry Clever Field Airport Medina County 4.5.3. Factor 3: Level of Control of Emissions Sources Under this factor, EPA considers the existing level of control of emissions sources. The emissions data used by EPA in this technical analysis and provided in Tables 4 and 5 above represent emissions levels taking into account any control strategies implemented on stationary sources in Stark County by 2020 and in the surrounding counties by 2017. The predominant source of Pb emissions in Stark County, the Republic Steel plant (Facility ID 1576050694), operates under a Title V permit (P0101210) and a synthetic minor New Source Review permit specifically for Pb. Emissions at the facility are subject to Ohio EPA rules, regulations, and orders. Emissions controls for Pb include the Continuous Bloom Casting Facility main Ladle Metallurgical Facility baghouse, FlexCast baghouse, and Meltshop baghouse. Emissions include fugitive emissions from the Continuous Bloom Casting Facility, FlexCast Building, and Meltshop Building.11 11 Ohio EPA Director's Final Findings and Orders, May 14, 2019. http:ffedocpub.epa. ohio.gov/pu blicportaM'iewDocument. aspx?docid= 1063293 16 ------- 4.5.4 Factor 4: Population Density and Degree of Urbanization including Commercial Development in Included Versus Excluded Areas The analysis for this factor considered population density for 2010-2020 in the area considered for the redesignation to nonattainment. Table 6 shows the 2010 and 2020 population data for Stark County and Canton, Ohio. These data help assess the extent to which the concentration of human activities in the area and concentration of population-oriented commercial development may indicate emissions-based activity contributing to elevated ambient Pb levels. This may include ambient Pb contributions from activities that would disturb Pb that has been deposited on the ground or on other surfaces. Re-entrainment of historically deposited Pb typically is not reflected in the emissions inventory. The EPA does not believe the population data provided in the analysis of this factor affect the boundary recommendation. Table 6. Population and Population Density Data for Canton and Stark County, Ohio Area 2010 Population* 2020 Population* 2010 Population Density (population / square mile)-- 2020 Population Density (population square mile)-- Stark County, Ohio 375,586 374,853 652.9 651.6 Canton, Ohio 73,007 70,872 2,867.3 2,805.7 Source: U.S. Census Bureau estimates for 2010 and 2020 (ihttps://www.census.gov/quickfacts/fact/table/US/PST045221) Based on 25.26 square miles for Canton, Ohio and 575.27 square miles for Stark County, Ohio. 4.5.5 Factor 5: Expected Growth This factor considers population growth for 2010-2020 in the area evaluated for the redesignation to nonattainment. Table 7 shows the population change for Canton and Stark County, Ohio from 2010 to 2020. Table 7. Change in Population and Population Density from 2010 to 2020 for Canton and Stark County, Ohio Area Population Population % Population Population Change 2010 - Change 2010 - Density Density % 2020 2020 Change (pop/sq mi)- 2010 - 2020 Change 2010 - 2020 Stark County, Ohio -733 -0.2 -1.3 -0.2 Canton, Ohio -2135 -2.9 -61.6 -2.1 * Based on 25.26 square miles for Canton, Ohio and 575.27 square miles br Stark County, 17 ------- Ohio. ** Source: U.S. Census Bureau estimates for 2010 and 2020 (ihttps://www.census.gov/quickfacts/fact/table/US/PST045221) From 2010 to 2020, population in Stark County declined by 0.2%, while population in the City of Canton declined by 2.9%. For the same time period, population density in Stark County declined by 0.2%, while population density in the City of Canton declined by 2.1%. The EPA has considered the growth rate for the population and population density for this area and does not believe that it affects the boundary determination. 4.5.6. Factor 6: Meteorology For this factor, EPA evaluates meteorological data to determine how weather conditions, including wind speed and direction, affect the plumes from sources contributing to the ambient Pb concentrations. Figure 5 below depicts a wind rose covering the 51-year period of meteorological records from 1970 to 2021 from the National Weather Service meteorological station at the Akron-Canton Airport in Akron, Stark County, Ohio near the Republic Steel ambient air monitoring site, 16 kilometers away. These data help depict the potential for Pb emissions sources located near a violating monitor to contribute to ambient Pb levels at the violation location. The wind rose depicts frequency and magnitude of wind speed and direction. The wind rose shows the distribution of wind direction independently from wind speed by dividing the data into 36 wind directions and six wind speed classes in addition to calm conditions. As shown in Figure 5, winds blow predominantly from the southwest 5% of the time at speeds of 16 - 24 kilometers per hour (10 - 15 miles per hour) 1.7% of the time. 18 ------- Figure 5. Wind Rose for North Canton, Stark County, Ohio Wind Speed [mph] ¦¦ 2-5 ¦¦ 5-7 7-10 10-15 ¦ 15-20 ¦¦ 20 + COM MEM'S DATA PERIOD IMAGE GENERATED BY Wind Rose is centered on Akron-Canton Airport, North Canton, Stark County. Ohio. Start Date: 01/01/1970 End Date: 08/09/2021 Iowa State University's Iowa Environmental Mesonet (IEM) https://mesonet. agron. iastate. edu/sites/locate.php Data provided by National Weather Service Data. Summary obs count: 508657 Missing: 5725 Avg Speed: 9.4 mph [CAK] Akron / Canton Windrose Plot Time Bounds: 01 Jan 1970 02:00 AM - 09 Aug 2021 01:51 AM America/New York Calm values are < 2,0 mph Arrows indicate wind direction. Generated: 09 Aug 2021 Evidence of source-receptor relationships between specific emissions sources and high Pb concentrations at violating monitors is another important factor in determining the appropriate contributing areas and the appropriate extent of EPA's nonattainment area. 19 ------- Figures 6 and 7 below, generated by EPA, depict a pollution rose and polar plot centered at the Republic Steel ambient air monitoring site (AQS Site No. 39-151-0024) covering the 3-year design value period from 2018-2020. The pollution rose and polar plot were developed using open-source software in the coding language, R. The graphical user interface, RStudio, was used along with the open-source R packages, openair and openairmaps.12 Figures 6 and 7 are based on data from a local meteorology site, which was only available from October 2018 through December 2020. As shown in Figure 6, the pollution rose illustrates the frequency distribution of wind direction correlated with Pb concentrations. The pollution rose is divided into 24 wind directions and five concentration ranges. Pb concentrations are based on the mean daily readings from the Republic Steel ambient air monitoring site corresponding with the available meteorology data during October 2018-December 2020.13 Of the winds from the east that reach the Republic Steel ambient air monitoring site, Figure 6 shows that approximately 1% of the winds range in Pb concentration from 0.075 to 0.30 (J,g/m3, and 1% of the winds range from 0.15 to 0.30 [j,g/m3. Of the winds from the west northwest, Figure 6 shows that approximately 8% of the winds range in Pb concentration from 0.075 to 0.15 (J,g/m3, 1% of the winds range from 0.15 to 0.30 (J,g/m3, 1% of the winds range from 0.30 to 1.00 (J,g/m3, and 1% of the winds range from 1.00 to 1.87 [j,g/m3. 12 Carslaw DC, Ropkins K (2012). "openair - An R Package for air quality data analysis." Environmental Modeling & Software, 27-28(0), 52-61. ISSN 1364-8152, doi: 10.1016/j.envsoft.2011.09.008. 13 EPA AirData Air Quality Monitors, Daily Data for 2018 - 2020 https://epa.maps. arcgis.com/apps/webappviewer/index. html?id=5f239fd3e72f424J98eJ3 d5deJ547eb5&extent=- 146.2334,13.1913,-46.3896,56.5319 20 ------- Figure 6: Pollution Rose for Pb Concentrations from Republic Steel Ambient Air Monitoring Site (AQS Site No. 39-151-0024), Canton, Stark County, Ohio t I moan - Q.OaeeM odm = 0% Concentration by Frequency 1 to 1.87 0.3 to 1 0.075 to 0.15 Pb {Lig m ) Frequency of counts by wind direction (%) COMMENTS Pollution Rose is centered on the Republic Steel Pb Ambient Air Monitoring Site (AQS Site No. 39-151-0024), 3150 Georgetown Road NE, Canton, Stark County, Ohio. Local meteorological data was obtained from a local meteorology site and was only available from October 2018 through December 2020. This figure only shows concentration data when winds were above calm (>0.45 m s"1) and during the timeframe when meteorology data was available (October 2018 - December 2020). DATA PERIOD Start Date: End Date: 01/01/2018 12/31/2020 CALM WINDS 0% IMAGE GENERATED BY U.S. EPA, Region 5 SOFTWARE R coding language 21 ------- Figure 7 is a polar plot centered around the Republic Steel ambient air monitoring site (AQS Site No. 39-151-0024) and superimposed on a map of the local area. The map also shows an outline of the Republic Steel parcel across the street at 2633 Eighth Street NE in Canton, Ohio. Polar plots are used to visualize mean pollutant concentrations across an area that vary by wind speed and wind direction. The concentric circles in the polar plot show wind speed in 0.5 meters/second (m/s) intervals. Superimposing a polar plot on a map is useful in exploring source directions of atmospheric pollutants. As shown in Figure 7, the polar plot demonstrates that a majority of Pb detected at the Republic Steel ambient air monitoring site is coming from the northwest and is distributed according to the concentration color palette. The highest Pb levels of 0.25 pg/m3 and greater are observed when wind is blowing from the northwest at speeds of 1.25 - 2.5 m/s. Pb concentrations are lower and less than 0.05 ug/nr' when wind is blowing from the south and east. Figure 7. Polar Plot Map of Mean Pb Ambient Air Concentrations (October 2018 - December 2020) N A 1.2 Miles I A * % PRO^ Service Layer Credits: Stark County GIS, Esri, HERE, Garmin, SafeGraph, INCREMENT P, MET1/NASA, USGS, EPA, NPS, US Census Bureau, USDA Pb (na m"1) 22 ------- For this area, winds can be from any direction. Therefore, sources in all directions can have some potential contribution. However, as noted in Section 4.5.2., Pb particles in the air tend to deposit rapidly with distance from the source according to their particle size and weight. The Republic Steel plant is the closest NEI source to the Republic Steel ambient air monitoring site and is the only source in Stark County with Pb emissions greater than 0.1 tons per year, and accounts for 80% of the Pb emissions from all the sources in Stark County that were reported in the 2017 NEI. Based on the Pb concentration frequencies in the pollution rose and polar plot in Figures 6 and 7, the majority of Pb detected at the Republic Steel ambient air monitoring site is coming from the northwest, where the Republic Steel plant is located; this analysis indicates that the Republic Steel plant is the primary contributor to the violations at the monitoring site. With wind directionality potentially affected by building downwash and vehicular traffic, elevated Pb levels at the Republic Steel ambient air monitoring site might also be coming from the north corresponding to the location of the larger emission sources at Republic Steel. 4.5.7 Factor 7: Geography/topography The geography/topography analysis evaluates the physical features of the land that may have an effect on the airshed and, therefore, on the distribution of Pb over the nonattainment area in Stark County. Stark County does not have any geographical or topographical barriers significantly limiting air pollution transport within its airshed. The terrain in Stark County is generally flat, rising in elevation from approximately 1,000 feet above mean sea level in the western portion of the county to 1,200 feet above mean sea level in the eastern portion of the county.14 There are no mountain ranges, basins, or other physical features that may affect distribution of emissions that would define area boundaries. 4.5.8 Factor 8: Jurisdictional Boundaries Existing jurisdictional boundaries may be helpful in determining a boundary for purposes of the redesignation to nonattainment, and for purposes of carrying out the governmental responsibilities of planning for attainment of the Pb NAAQS and implementing control measures. These existing boundaries may include an existing nonattainment or maintenance area boundary, a county or township boundary, a metropolitan area boundary, an air management district, or an urban planning boundary established for coordinating business development or transportation activities. We typically base designations on clearly defined legal boundaries that align with existing administrative boundaries, when reasonable. In accordance with the 2008 Pb NAAQS final rule, the presumptive boundary of the nonattainment area is the entire county with a violating monitor as described above under Section 4.1. The State and/or EPA may conduct additional area-specific analyses that could lead 14 EPA AirData Air Quality Monitors, Topographic Basemap, https://epa.maps. arcgis.com/apps/webappviewer/index. html?id=5f239fd3e72f424J98eJ3 d5deJ547eb5&extent=- 146.2334,13.1913,-46.3896,56.5319 23 ------- to a departure from the presumptive boundary. The Republic Steel plant and violating ambient air Pb monitoring site (AQS Site No. 39-151- 0024) are located within a small portion of the jurisdictional boundary of Stark County, Ohio. Based on the directionality of elevated Pb concentrations depicted in the pollution rose and polar plot in Figures 6 and 7, the absence of other contributing sources, and the consideration of the other seven factors above, EPA's nonattainment area is smaller than the entire county. Rather than jurisdictional boundaries, EPA's nonattainment area is centered around the Republic Steel plant and is bounded by the following major roadways within Canton, Ohio: North: State Route OH-153 (12th Street NE; Mahoning Road) East: Broadway Avenue South: State Route OH-172 (Tuscarawas Street E; Lincoln Street E) West: State Route OH-43 - Northbound (Cherry Avenue NE) EPA's determined nonattainment area includes the area surrounding the violating monitor, the source most likely contributing to the violating monitor, the area where Pb concentrations in the ambient air violate the 2008 Pb NAAQS, and boundaries that are easily recognizable by the public. 4.5.9 Additional Information provided by the State In addition to an analysis of the eight factors above, states can choose to recommend Pb nonattainment boundaries by using any one, or a combination, of the following techniques (73 FR 67033): • Qualitative analysis; • Spatial interpolation of air quality monitoring data; or • Air quality simulation by dispersion modeling. These techniques are more fully described in "Procedures for Estimating Probability of Nonattainment of a PM-10 NAAQS Using Total Suspended Particulate of PM-10 Data," December 1986. See 57 FR 13549. When EPA notified the State of Ohio regarding our intended redesignation on April 26, 2022, EPA provided a 120-day period for the state to respond and encouraged the state to provide additional information relevant to establishing a nonattainment area boundary for this area. On August 22, 2022, Ohio responded by concurring with EPA's intended boundaries for the proposed nonattainment area. 4.6 Summary of EPA's Assessment and Redesignation for the Canton, Ohio Area The Republic Steel ambient air monitoring site in Stark County indicates violations of the 2008 Pb NAAQS based on the 2019-2021 design value. Under CAA section 107(d)(1), following promulgation of a new or revised NAAQS, EPA must designate areas that violate the NAAQS 24 ------- and nearby areas that contribute to the violations as nonattainment areas. Although Stark County was designated as unclassifiable/attainment in 2011, the EPA Administrator may notify the state at any time that a designation should be revised. See CAA section 107(d)(3). After careful evaluation of the information in this TSD, and considering the state's concurrence on EPA's intended redesignation, EPA is redesignating a portion of Stark County, specifically around Canton, Ohio, as nonattainment for the 2008 Pb NAAQS. To determine the geographic extent of the nonattainment area in Stark County, EPA evaluated the eight factors in the 2008 EPA Pb Guidance. The Republic Steel and Republic Community ambient air monitoring sites (AQS Site Nos. 39- 151-0024, 39-151-0025) are the only Pb monitoring sites that report to EPA's AQS in Stark County, and Columbiana County is the only surrounding county with such Pb monitoring sites. Of these monitoring sites, only the Republic Steel monitoring site measured violations of the 2008 Pb NAAQS, with a 2019-2021 design value of 0.40 [j,g/m3. The remaining three monitoring sites with design values, located approximately 69 kilometers southeast in neighboring Columbiana County, are well below the 2008 Pb NAAQS with a 2019-2021 design value of 0.01 [j,g/m3. The Republic Steel plant, located at 2633 Eighth Street NE, Canton, Ohio, is the largest source of Pb emissions located near the violating monitor (AQS Site No. 39-151-0024) and the only source in Stark County with Pb emissions greater than 0.1 tons per year. Other sources of Pb emissions greater than 0.1 tons per year in surrounding counties were more than 15 kilometers away and, as noted in Section 4.5.2., are not anticipated to contribute to violations of the 2008 Pb NAAQS at the Republic Steel ambient air monitoring site. The Pb concentration frequencies depicted in the pollution rose and polar plot in Figures 6 and Figure 7 demonstrate the majority of Pb detected at the Republic Steel ambient air monitoring site is coming from the west northwest, in the direction of the Republic Steel plant. As such, the relevant information indicates the Republic Steel plant is the primary contributor to the violations at the monitoring site for the 2019-2021 design value period. Based on the directionality of elevated Pb concentrations, as depicted in the pollution rose and polar plot in Figures 6 and 7, as well as the absence of other contributing sources and consideration of the eight factors above, EPA's nonattainment area is centered around the Republic Steel plant and is smaller than the presumptive county-wide boundary in the 2008 Pb NAAQS final rule. The technical analysis shows that the excluded portions are not source areas that contribute to the observed violations. After considering the factors above, EPA's revision to the area's designation is to designate the area to nonattainment, and to establish the boundaries of the nonattainment area to encompass the area surrounding the violating monitor (AQS Site No. 39-151-0024), the source most likely contributing to the violating monitor, and the area that does not meet the 2008 Pb NAAQS. Population, expected growth, geography, and topography did not play a significant role in determining the nonattainment boundary. The nonattainment area, bounded by the following major roadways within Canton, Ohio, will 25 ------- have clearly defined boundaries, and we find these boundaries to be a suitable basis for defining the nonattainment area. North: State Route OH-153 (12th Street NE; Mahoning Road) East: Broadway Avenue South: State Route OH-172 (Tuscarawas Street E; Lincoln Street E) West: State Route OH-43 - Northbound (Cherry Avenue NE) Figure 8 shows the boundaries of this designated area. 26 ------- Figure 8. Boundaries of the Canton, Ohio Nonattainment Area for the 2008 Pb NAAQS Center PLAIN * CITY Nimishillen M alone Univerjiiy COLONIAL HEIGHTS Heights COLONIAL HEIGHTS HISTORIC RIDGEWOOD OAK PLACE VASSAR PARK GIBBS AREA Lynn Center Park DOWNTOWN Canton CONCER1 1TIZENS OF 4TH EW HOPE ESTATES Clear View Heights Legend Violating Pb Monitor 39-151-0024 (2019 - 2021 Design Value) ~ Perimeter of Pb Source > 0.5 tons/year (2017 NEI), Republic Steel, 2633 Eighth Street NE, Canton, Ohio, Stark County EPA's Nonattainment Boundary North: State Route OH-153 (12th Street NE, Mahoning Road) East: Broadway Avenue South: State Route OH-172 (Tucarawas Street E, Lincoln Street E) West: State Route OH-43 - Northbound (Cherry Avenue NE) 27 ------- |