2020-07143. Air Plan Approval; Missouri and Kansas; Determination of Attainment for the Jackson County, Missouri 1-Hour Sulfur Dioxide Nonattainment Area and Redesignation of the Wyandotte County, Kansas Unclassifiable Area to Attainment/...

AGENCY:

Environmental Protection Agency.

ACTION:

Proposed rule.

SUMMARY:

The Environmental Protection Agency (EPA) is proposing to determine that the Jackson County, Missouri 1-hour (1-hr) Sulfur Dioxide (SO₂) National Ambient Air Quality Standard (NAAQS) Nonattainment Area has attained the NAAQS and to redesignate the Wyandotte County, Kansas 1-hr SO₂ NAAQS Unclassifiable Area as Attainment/Unclassifiable. Both proposed decisions are based on air quality monitoring and modeling data.

DATES:

Comments must be received on or before May 15, 2020.

ADDRESSES:

You may send comments, identified by Docket ID No. EPA-R07-OAR-2020-0155 to https://www.regulations.gov. Follow the online instructions for submitting comments.

Instructions: All submissions received must include the Docket ID No. for this rulemaking. Comments received will be posted without change to https://www.regulations.gov/​,, including any personal information provided. For detailed instructions on sending comments and additional information on the rulemaking process, see the “Written Comments” heading of the SUPPLEMENTARY INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT:

Tracey Casburn, Environmental Protection Agency, Region 7 Office, Air Quality Planning Branch, 11201 Renner Boulevard, Lenexa, Kansas 66219; telephone number [phone]; email address [e-mail].

SUPPLEMENTARY INFORMATION:

Throughout this document “we,” “us,” and “our” refer to the EPA.

Table of Contents

I. Written Comments

II. What action is the EPA proposing?

III. What is the background of this action?

A. Designations

B. Clean Data Policy

C. How does a nonattainment area achieve “Clean Data” for the 2010 1-hr primary SO₂ NAAQS?

D. What are the criteria to be redesignated from unclassifiable to attainment/unclassifiable?

E. What information did Missouri provide to the EPA to demonstrate that the jackson county area has attained the NAAQS?

F. What information did Kansas provide to the EPA to demonstrate that the Wyandotte County area should be redesignated from unclassifiable to attainment/unclassifiable?

G. What is the EPA's rationale for proposing this action?

i. Jackson County, Missouri

ii. Wyandotte County, Kansas

IV. What is the EPA's analysis of the air quality monitoring and modeling data?

A. Monitoring Data

B. Jackson County Clean Data Modeling

i. Meteorological Data

ii. Background Concentration

iii. Source Characteristics

iv. Emissions Data

v. Results

C. Wyandotte County Redesignation Modeling

i. Meteorological Data

ii. Background Concentration

iii. Source Characteristics

iv. Emissions Data

v. Connection to the Jackson County Clean Data Modeling

vi. Results

V. When promulgated, what are the effects of this action?

A. Jackson County, Missouri

B. Wyandotte County, Kansas

VI. Statutory and Executive Order Reviews

I. Written Comments

Submit your comments, identified by Docket ID No. EPA-R07-OAR-2020-0155, at https://www.regulations.gov. Once submitted, comments cannot be edited or removed from Regulations.gov. The EPA may publish any comment received to its public docket. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission (i.e. on the web, cloud, or other file sharing system). For additional submission methods, the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit https://www.epa.gov/​dockets/​commenting-epa-dockets.

II. What action is the EPA proposing?

The EPA is proposing to determine that the Jackson County 2010 1-hr primary SO₂ nonattainment area (hereby referred to as the “Jackson County area”), in Missouri, has attained the 2010 1-hr primary SO₂ NAAQS.^[1] This proposed determination of attainment is based on a May 2018 request (later supplemented) from the Missouri Department of Natural Resources (MoDNR) asking the EPA to consider complete, quality assured, and certified ambient air monitoring data from the 2015-2017 monitoring period and make a determination that the area has attained the 2010 1-hr primary SO₂ NAAQS.^[2 3]

The EPA is also proposing to redesignate the Wyandotte County, Kansas 1-hr SO₂ NAAQS unclassifiable area (hereinafter referred to as the “Wyandotte County area”) to attainment/unclassifiable based on a January 2017 request from the Kansas Department of Health and Environment (KDHE).^[4] The EPA's proposed redesignation of the Wyandotte County area is based on air quality dispersion modeling submitted by the KDHE and supplemented by modeling analysis from the MoDNR for the Jackson County area. The relationship between the MoDNR's modeling analysis and the Wyandotte County area is explained in more detail in the “What is the EPA's Analysis of the Information Submitted by the States?” and “Connection to the Jackson County Clean Data Modeling” sections of this document.

The EPA has made the monitoring and modeling data available in the docket to this rulemaking through www.regulations.gov.

III. What is the background of this action?

A. Designations

On June 2, 2010, the EPA established a health-based 1-hour primary SO₂ NAAQS at 75 ppb.^[5] Upon promulgation of a new or revised NAAQS, section 107(d) of the Clean Air Act (CAA) requires the EPA to designate any area that does not meet (or that contributes to ambient air quality in a nearby area that does not meet) the NAAQS as nonattainment.

In our final designations published on August 5, 2013, also known as Round 1 of the 2010 1-hr SO₂ NAAQS designations process, the EPA designated a portion of Jackson County, Missouri, as nonattainment for the 2010 1-hr primary SO₂ NAAQS, effective October 4, 2013.^[6 7] The designation was based on 2009-2011 monitoring data from the Troost monitor in Kansas City, Missouri, which monitored violations of the standard (see section IV. of this document for additional monitoring information). The effective date of the nonattainment designation was October 4, 2013. The CAA establishes that areas designated as nonattainment must attain the standard no later than five years from the date of designation (i.e., by October 4, 2018). The MoDNR was also required to submit a State Implementation Plan (SIP) for the nonattainment area to the EPA that meets the requirements of CAA sections 110, 172(c) and 191-192 within 18 months following the October 4, 2013, effective date of designation (i.e., by April 4, 2015). The MoDNR submitted the “Nonattainment Area Plan for the 2010 1-Hour Sulfur Dioxide National Ambient Air Quality Standard—Jackson County Sulfur Dioxide Nonattainment Area” on October 16, 2015. The MoDNR withdrew the attainment plan, except for the baseline emissions inventory, from the EPA's consideration and review for action on June 6, 2018.^[8]

In our final designations published on July 12, 2016, also known as Round 2 of the 2010 1-hr SO₂ NAAQS designations process, the EPA designated the Wyandotte County area as unclassifiable. The unclassifiable designation was based on information the KDHE provided to the EPA. The KDHE air dispersion modeling analyses indicated modeled compliance with the NAAQS. However, the modeling analyses included emission rates for sources in Missouri that weren't reflective of actual emissions or the sources' federally enforceable allowable emissions at the time of designation.^[9] Based on this information, the EPA determined that it did not have enough information demonstrating whether the Wyandotte County Area was or was not meeting the 2010 1-hr SO₂ NAAQS or its impacts on the Jackson County area.

B. Clean Data Policy

Where states request a clean data determination of a designated SO₂ NAAQS nonattainment area, the EPA will determine whether an area has attained the NAAQS based on air quality monitoring data (when available) and air quality dispersion modeling information for the affected area as necessary. The EPA issued “Clean Data” policy memoranda for SO₂ and other NAAQS describing suspended attainment planning requirements for nonattainment areas that are attaining the NAAQS, but have not yet been redesignated to attainment.^10 11Additionally, the EPA has issued national rulemakings that have codified this policy for ozone and fine particulate matter (PM_2.5) NAAQS.^[12] Under the Clean Data Policy, the EPA interprets the requirements of the CAA that are specifically designed to help an area achieve attainment, such as attainment demonstrations and implementation of reasonably available control measures (including reasonably available control technology), reasonable further progress (RFP) demonstrations, and contingency measures, to be suspended as long as air quality continues to meet the standard.

In the memorandum of April 23, 2014, from Steve Page, Director, EPA Office of Air Quality Planning and Standards to the EPA Air Division Directors “Guidance for 1-hr SO₂ Nonattainment Area SIP Submissions” (2014 SO₂ Guidance), the EPA explained its intention to extend the Clean Data Policy to 1-hour SO₂ nonattainment areas that attained the standard. As noted therein, the legal bases set forth in the various guidance documents and regulations establishing the Clean Data Policy for other pollutants are equally pertinent to all NAAQS.^[13] This proposed rule is also consistent with prior actions of the EPA applying the Clean Data Policy to two other nonattainment areas under the 2010 1-hr SO₂ NAAQS.^[14]

Clean data determinations are not redesignations from nonattainment to attainment. For the EPA to redesignate a nonattainment area to attainment, a state must submit and receive full approval of a redesignation request that satisfies all of the statutory criteria for redesignation to attainment, including a demonstration that the improvement in the area's air quality is due to permanent and enforceable reductions; have a fully approved SIP that meets all of the applicable requirements under CAA section 110 and CAA part D; and have a fully approved maintenance plan.

C. How does a nonattainment area achieve “Clean Data” for the 2010 1-hr primary SO ₂ NAAQS?

Generally, the EPA relies on ambient air quality monitoring data alone in order to make determinations of attainment for areas designated nonattainment for a NAAQS. However, given the Agency's historical approach toward SO₂, the source-specific nature of SO₂ emissions, and the localized effect of those emissions, in the preamble to the 2010 1-hr primary SO₂ NAAQS rulemaking, the EPA stated that it did not expect to rely solely on monitored air quality data in all areas when determining if an area has attained the 2010 1-hr primary SO₂ NAAQS (75 FR 35551, June 22, 2010). As the EPA noted in the preamble, in order for the EPA to determine that an area is attaining the 2010 1-hr primary SO₂ NAAQS, dispersion modeling may be needed to show that there are no violating receptors even if a monitoring site showed no violations.^[15] This was because, as the EPA explained in the preamble, the Agency did not expect that most existing SO₂ monitors were well sited to record maximum 1-hour ambient SO₂ concentrations under the new NAAQS. The 2014 SO₂ Guidance states that, for a nonattainment area that was designated based on air quality monitoring data to be determined as attaining the NAAQS, the state would need to meet a series of criteria. First, the state would need to demonstrate that the area is meeting the standard based on three consecutive calendar years of air quality monitoring that is complete and quality-assured (consistent with 40 CFR part 58 requirements). Second, the state would need to either (1) provide modeling of the most recent three years of actual emissions for the area or (2) provide a demonstration that the affected monitor(s) is or are in the area of maximum concentration. As explained in more detail in section (d) below, the EPA finds that it is permissible to substitute current source-specific federally enforceable and in effect allowable emissions for actual emissions for the purpose of demonstrating (1) above as long as certain requirements are met.

If a demonstration shows that the monitor(s) is or are in the area of maximum concentration, the EPA finds that it may be appropriate to determine that the nonattainment area is attaining the standard based on monitoring data alone.

The 2014 SO₂ Guidance states that, when air agencies provide monitoring and/or modeling to support clean data determinations, the monitoring data provided by the state should follow the EPA's “SO₂ NAAQS Designations Source-Oriented Monitoring Technical Assistance Document” (SO₂ Monitoring TAD) and the modeling provided by the state should follow the EPA's “SO₂ NAAQS Designations Modeling Technical Assistance Document” (SO₂ Modeling TAD).^[16] The SO₂ Modeling TAD outlines modeling approaches for characterizing air quality under the 2010 SO₂ NAAQS for designations. In the SO₂ Modeling TAD, the EPA recommends using a minimum of the most recent three years of actual emissions data, and concurrent meteorological data, so that the modeling better simulates what an ambient air monitor would observe.

D. What are the criteria to be redesignated from unclassifiable to attainment/unclassifiable?

Section 107(d)(3) of the CAA provides the framework for changing the area designations for any NAAQS pollutant. Section 107(d)(3)(A) provides that the Administrator may notify the Governor of any state that the designation of an area should be revised “on the basis of air quality data, planning and control considerations, or any other air quality-related considerations the Administrator deems appropriate.” The Act further provides in section 107(d)(3)(D) that even if the Administrator has not notified a state Governor that a designation should be revised, the Governor of any state may, on the Governor's own motion, submit a request to revise the designation of any area, and the Administrator must approve or deny the request.

When approving or denying a request to redesignate an area, the EPA bases its decision on the air quality data for the area as well as the considerations provided under section 107(d)(3)(A).^[17] In keeping with section 107(d)(1)(A), areas that are redesignated to attainment/unclassifiable must meet the requirements for attainment areas and thus must meet the relevant NAAQS. In addition, the area must not contribute to ambient air quality in a nearby area that does not meet the NAAQS.

For designations, the SO₂ Modeling TAD indicates that it is acceptable to use federally enforceable and in effect allowable emission rates instead of actual emission rates. Although past actual emissions could have been higher than those under the most recent allowable rate, the SO₂ Modeling TAD reflects the EPA's belief that it is reasonable to account for any lower allowable limits currently federally enforceable and in effect when determining if an area is attaining the NAAQS. In addition, the SO₂ Modeling TAD indicates that, where an allowable emissions limit has been lowered during the relevant three-year period (such as through the implementation of emissions controls), the air agency may rely on the new federally enforceable and in effect limit in demonstrating that the modeled limit assures attainment. In this fashion, the most recent permitted or potential to emit rate should be used along with a minimum of the most recent three years of meteorological data.^[18]

The EPA finds that modeling a mix of current allowable emissions and actual emissions would be consistent with the SO₂ Modeling TAD for designations if the same type of emissions is used for each source for all three years. For instance, if a state decided to use current federally enforceable and in effect allowables for a facility in a modeling analysis, the state would need to use current allowables for all three years of the analysis for that facility. The state would not necessarily need to use current allowables for the other sources in the analysis (i.e., actuals would be permissible for all three years for other sources in the area). The EPA finds this kind of analysis is sufficient for clean data determinations, which, similar to designations, use the analysis to determine whether the area is currently meeting the NAAQS. We also believe that this analysis can be used for purposes of a redesignation of an area from unclassifiable to attainment/unclassifiable, where the inquiry is also whether the area is factually attaining the NAAQS. Such redesignations are functionally similar to initial designations and are not subject to the requirements of CAA section 107(d)(3)(E), which require attainment to be due to permanent and enforceable measures and which require a demonstration that the area will maintain the NAAQS for ten years. Per the 2014 SO₂ Guidance, in redesignations of nonattainment areas to attainment, which are subject to the requirements of CAA section 107(d)(3)(E), states will be expected to use federally enforceable and in effect allowable emissions in air quality modeling.

The EPA recognizes that its 2014 SO₂ Guidance does not on its face suggest that modeling allowable emissions or a mix of allowable and actual emissions would be an acceptable alternative to modeling actual emissions in the clean data determination or redesignation of an area from unclassifiable to attainment/unclassifiable contexts. However, the Agency considers it to have been an oversight on its part not to have addressed this alternative possibility in the 2014 SO₂ Guidance, as the Agency clearly has endorsed the use of both actual emissions and allowable emissions in the SO₂ Modeling TAD in general and in the recent rounds of area designations under the SO₂ NAAQS, in contexts where, as here, the Agency is making a factual judgment about whether an area has attained the NAAQS. Moreover, the 2014 guidance also suggests that modeling of allowable emissions, combined with other information, could also be used to determine whether, after the attainment deadline has passed, areas in fact timely attained the NAAQS under CAA section 179. Therefore, although the SO₂ Nonattainment Area Guidance was silent on using allowable emissions in the clean data determination and redesignations of an area from unclassifiable to attainment/unclassifiable contexts, the EPA finds that it is not inconsistent with the guidance to endorse that practice now, provided the allowables-based modeling is conducted appropriately pursuant to the SO₂ Modeling TAD and the code of federal regulations at 40 CFR part 51, appendix W—Guideline on Air Quality Models (hereafter referred to as “appendix W”) and regulations governing stack heights and dispersion techniques at 40 CFR 51.100 and 40 CFR 51.118 when applicable.

E. What information did Missouri provide to the EPA to demonstrate that the Jackson County area has attained the NAAQS?

On May 4, 2018, the MoDNR submitted a request asking the EPA to determine that the nonattainment area attained the 2010 1-hr SO₂ NAAQS per the EPA's Clean Data Policy. The request included three years of complete, quality assured, and certified ambient air monitoring data from the 2015-2017 monitoring period; the design value (dv) for 2015-2017 was 57 ppb. In a response letter, dated November 13, 2018, the EPA stated that, because the request did not include a modeling demonstration showing attainment utilizing the most recent three years of actual emissions or a demonstration that the monitor was located in the area of maximum concentration for the nonattainment area, the state's request did not contain the necessary supporting information as outlined in the EPA's 2014 SO₂ Guidance. In an emailed letter dated March 1, 2019, the state provided modeling of the most recent three years of actual emissions (2016-2018) for the nonattainment area. However, the EPA verbally expressed concern to the MoDNR regarding data used to derive the background concentration in the modeling analysis.^[19] The MoDNR responded via email with an update to its modeling analysis.^[20] On April 24, 2019, via email, the MoDNR submitted an explanation of its interpretations of regulations and guidance, in particular its interpretations of appendix W and guidance in regard to determining background concentrations and which sources needed to be included in the clean data determination modeling analysis. The EPA continued to provide guidance to the MoDNR regarding background concentration analysis and sources to include in the model. On June 19, 2019, via email, the MoDNR submitted a revised modeling demonstration (hereafter referred to as the Jackson County clean data determination modeling) to support its request that the EPA determine the Jackson County area has attained the 2010 1-hr SO₂ NAAQS. In the Jackson County clean data determination modeling, the State adjusted its background concentration and included additional sources outside of the area in the model using actual emissions. The MoDNR submitted a correction to its June 19, 2019 modeling files on February 26, 2020. The correction ensured that the modeling files were reflective of the narrative description of how the MoDNR calculated and modeled hourly emission rates for sources that did not have Continuous Emissions Monitoring Systems (CEMS).^[21] The EPA is proposing to determine that the Jackson County area has attained the NAAQS based on its review of the MoDNR's June 19, 2019, Jackson County clean data determination modeling submittal and the February 2020 correction along with the monitored ambient air data.

F. What information did Kansas provide to the EPA to demonstrate that the Wyandotte County area should be redesignated from unclassifiable to attainment/unclassifiable?

On September 17, 2015, the KDHE provided an air dispersion modeling analysis that demonstrated that the Wyandotte County Area was in attainment of the 2010 1-hr SO₂ NAAQS as part of its area designation recommendations for the Round 2 designations process.^[22 23] During the public comment period for the proposed designations, the EPA received revised modeling from Kansas City Board of Public Utilities (BPU) (hereinafter referred to as the “BPU March 2016 modeling”) for the Wyandotte County area.^[24] In its January 2017 Round 3 designations boundary recommendation submittal, the KDHE recommended that the EPA designate the Wyandotte County area as “unclassifiable/attainment” (we have already discussed the change in classification to “attainment/unclassifiable” in the “What Action is the EPA Proposing?” section of this document). Because the area was already designated in Round 2, the EPA had no obligation to consider the KDHE's recommendation for the Wyandotte County area at that time and instead said that it would consider the KDHE's request for redesignation in a separate action.^[25] The KDHE resubmitted the BPU March 2016 modeling to the EPA in January 2017 as part of its redesignation request for the Wyandotte County area. The EPA is proposing to redesignate the Wyandotte County area based on the BPU March 2016 modeling and the MoDNR's Jackson County area clean data determination modeling (with the February 2020 correction). The BPU March 2016 modeling and the MoDNR's June 19, 2019, Jackson County clean data determination modeling (and the February 2020 correction) are described in more detail in “What is the EPA's Rationale for Proposing this Action?” section of this document.

G. What is the EPA's rationale for proposing this action?

i. Jackson County, Missouri

The EPA is proposing to issue a determination of attainment for the Jackson County area based on the area's 2016-2018 monitoring data at the Troost monitor and the MoDNR's June 19, 2019 updated modeling demonstration (with the February 2020 correction).^[26] The 2014 SO₂ Guidance recommends that states, at a minimum, model the most recent three years of actual emissions data and concurrent meteorological data, for the modeling to simulate what a monitor would observe.

The state modeled actual emissions for all sources inside of, and 20 kilometers (km) from, the nonattainment area.^[27] The modeled 3-year DV in the clean data determination modeling analysis is 113.9 μg/m^[3] , or 43.5 ppb, which meets the 1-hour standard of 75 ppb.^[28] The model results satisfy the criteria for determinations of attainment according to the EPA's guidance and policy. See section IV.b. “Jackson County Clean Data Modeling” for more information regarding the EPA's analysis of the modeling submitted by the MoDNR.

ii. Wyandotte County, Kansas

The unclassifiable designation for the Wyandotte County area was based on modeling information the KDHE and the BPU provided to the EPA in 2015 and 2016. Although both air dispersion modeling analyses demonstrated that the Wyandotte County area would be in attainment with the 2010 1-hr SO₂ NAAQS based on the emissions rates used in the modeling, the EPA was not able to rely upon the analyses to designate the Wyandotte County Area as attainment/unclassifiable.

In our February 16, 2016, notice of intended designations, the EPA stated that it was not able to rely upon the September 2015 modeling analysis provided by KDHE because: Certain emission rates included in the model did not represent either the most recent three years of actual emissions or the federally enforceable and in effect allowable emission limits from sources in Missouri; a source of SO₂ emissions in Missouri was excluded—Independence Power and Light (IPL)-Blue Valley; concerns with the modeling receptor grid; and the inclusion of a stack at the BPU-Nearman facility as a building structure.^[29] Specifically, the emission rates used in the modeling analysis submitted by KDHE in September 2015 for the following emission points (EP) were at issue (e.g., State only limits): Veolia EP1, EP2, and EP3; IPL-Missouri City EP5 and EP6; Kansas City Power and Light (KCPL)-Sibley EP5A, EP5B and EP5C; KCPL-Hawthorn EP6 (Unit 5); and IPL-Blue Valley EP3, EP4, and EP5.^[30]

During the public comment period, the EPA received revised modeling from BPU (the “BPU March 2016” modeling) for the Wyandotte County area.^[31] Although the BPU March 2016 modeling submittal expanded the modeled receptor grid to include portions of Platte, Clay and Jackson counties in Missouri, added IPL-Blue Valley, removed the stack as a building structure, and included several Missouri sources at their actual emission rates instead of State only limits, the modeling continued to rely on emission rates for Veolia that were based on State only limits.^[32 33] The BPU March 2016 modeling utilized: 2013 Actual emission data for IPL-Missouri City EP5 and EP6; and IPL-Blue Valley EP3, EP4 and EP5; 3-years of CEMS data (2012-2014) for KCPL-Sibley EP5A, EP5B and EP5C and KCPL-Hawthorn EP6 (Unit 5). The KDHE resubmitted the BPU March 2016 modeling to the EPA in January 2017 as part of its redesignation request for the Wyandotte County area.

As already noted, the BPU March 2016 modeling utilized emission rates that were neither representative of the federally enforceable and in effect emission rates nor the most recent three years of actual emissions for Veolia. However, subsequent to the Round 2 designations, Missouri issued air construction permit #122016-009, effective on December 21, 2016, to Veolia limiting EP1 and EP2 to natural gas only, removing the permitted ability for EP1 to also burn fuel oil as a back-up and removing the permitted ability for EP2 to burn coal and fuel oil as a back-up.^[34 35] A title V operating permit, permit #OP2018-006, was issued in 2018. The title V operating permit included a requirement that the facility burn natural gas only in EP3-removing fuel oil as a back-up.^{[36 37 38]}

With the issuance of the Veolia 2016 construction and 2018 operating permits, the emission rates used in the BPU March 2016 modeling are now conservative (i.e. overestimating the emission rates) in relation to the federally enforceable and in effect emission rates for that source. That is, the allowable facility-wide emissions rate used in the BPU March 2016 modeling, based on state only limits, was 352.8 pounds per hour. With the issuance of the 2016 construction permit and the 2018 operating permit, EP1, EP2 and EP3 are now limited to natural gas combustion only. The estimation of the facility-wide maximum emissions based on natural gas is 1.06 pounds per hour.^[39] In the Jackson County clean data determination modeling, discussed in more detail in sections IV.b and IV.c.v of this document, Veolia was modeled using the most recent three years (2016-2018) of actual emissions which include a mixture of EP2 burning coal on some days in 2016 and 2017 and natural gas only in 2018. See table 5 in section IV.c.v. for a comparison of the BPU March 2016 model emission rates and the Jackson County clean data determination model emission rates.

Further, in the BPU March 2016 modeling, 2013 actual emissions for IPL-Blue Valley Units EP3, EP4 and EP5 were used in each of the three years modeled (2012-2014). These actual emissions reflect coal combustion, and the possibility to burn fuel oil as a back-up. In 2015, IPL-Blue Valley switched to natural gas with fuel oil as back-up.^[40] The EPA proposes to find that the BPU March 2016 modeling emissions rates, based on coal (and the possibility to burn fuel oil as a back-up), are either representative of actual emissions before the switch to natural gas or conservative compared to the actual emissions from current natural gas operations (and the ability to burn fuel oil as a back-up) for the most recent three years of actual emissions and can therefore be relied upon in the analysis.^[41] In the Jackson County clean data determination modeling, discussed in more detail in sections IV.b and IV.c.v of this document, IPL-Blue Valley was modeled using the most recent three years (2016-2018) of actual emissions. See table 5 in section IV.c.v. for a comparison of the BPU March 2016 model emission rates and the Jackson County clean data determination model emission rates.

The EPA also notes that it is unlikely that IPL-Blue Valley's actual emissions will increase significntly as the operating permit clearly limits the fuel for EP3, EP4 and EP5 to natural gas only with limited fuel oil backup. All of the emission units in the permit that supported coal combustion (such as coal handling equipment) have been removed from permit OP2017-27, effectively eliminating coal combustion as a fuel option at the facility.^[42] In addition, the basis for the non-applicability of 40 CFR part 63, subpart UUUUU in the permit is the fact that the emission units are not coal-fired or oil-fired electric utility steam generating units. As discussed in the Statement of Basis to OP2017-27, the facility submitted a construction permit application in 2014 to cease firing coal in EP5. Missouri ultimately determined that a construction permit was not required, presumably because the project did not result in an increase in emissions that were greater than Missouri's minor New Source Review permitting thresholds, but the application signaled IPL's intent to cease burning coal for EP5. With the issuance of OP2017-27, IPL's intent to cease burning coal became memorialized in the facility's federally enforceable title V air permit.

Regarding the potential to combust fuel oil as a back-up, the source is limited to a period of less than 48-hours annually to combust fuel oil. Additionally, although noted under a requirement for particulate matter (10 10 CSR 10-6.405, Restriction of Particulate Matter Emissions from Fuel Burning Equipment Used for Indirect Heating), the permit states that because the source is limited to burning natural gas or fuel oil with less than 1.2 percent sulfur content, the source is in compliance with the MoDNR's particulate matter regulation. Given how few hours the facility is permitted to burn fuel oil, the facility when burning fuel oil may be treated as an intermittent source that, in accordance with EPA's intermittent source policy, need not be explicitly modeled.

Additionally, in the 2016 BPU modeling analysis IPL-Missouri City emission rates were based on actual emissions from 2013. In September 2015, the IPL-Missouri City units ceased power generation and are in the process of being demolished. Since the two IPL-Missouri City units are no longer able to operate, the EPA proposes to find that the emission rates used in BPU's modeling based on 2013 actual emissions are conservative compared to the most recent three years of actual emissions rates, and notes that actual emissions rates are likely to remain zero given that the source has ceased operation.^[43] In the Jackson County clean data determination modeling, discussed in more detail in sections IV.b and IV.c.v of this document, IPL-Missouri City was modeled using the most recent three years (2016-2018) of emissions which were zero. See table 5 in section IV.c.v. for a comparison of the BPU March 2016 model emission rates and the Jackson County clean data determination model emission rates.

Therefore, the EPA is proposing that because the 2016 BPU modeling now represents the Missouri emission points—Veolia EP1, EP2, and EP3; IPL Missouri City EP5 and EP6; KCPL Sibley EP5A, EP5B and EP5C; KCPL Hawthorn EP6; and IPL Blue Valley EP3, EP4, and EP5—at either their 2013 actual emission rate (KCPL-Sibley and Hawthorn), a rate that is higher than a federally enforceable and in effect facility wide maximum emission rate or most recent three years of actual emissions, depending on the emissions unit (Veolia), or emission rates that are higher than the sources' most recent three years of actual emission rates (IPL-Blue Valley and Missouri City), in addition to the Missouri June 19, 2019 clean data determination modeling (with the February 2020 correction) clearly showing that when considering 2016-2018 actual emissions the Wyandotte County sources are not causing or contributing to a modeled violation of the NAAQS, it can now consider the BPU March 2016 modeling to redesignate the Wyandotte County Area to attainment/unclassifiable. The EPA acknowledges that the BPU March 2016 modeling was developed using an earlier version of the Modeling TAD, however, the EPA proposes to find that the changes at issue in the update to the TAD should not impact reliability of the modeling.^[44] The EPA's analysis of the BPU March 2016 modeling is provided in the “What is the EPA's Analysis of the Air Quality Monitoring and Modeling Data?” section of this document.

IV. What is the EPA's analysis of the air quality monitoring and modeling data?

A. Monitoring Data

According to the 2014 SO₂ Guidance, to support a clean data determination based on monitoring, the State needs to demonstrate that the area is meeting the standard based on three consecutive calendar years of complete and quality-assured air quality monitoring data (consistent with 40 CFR part 58 requirements) at an air quality monitor that is demonstrated to be in the area of maximum concentration. The EPA has determined that three complete consecutive calendar years of quality-assured air quality monitoring data from the Troost (Jackson County, Missouri) and JFK (Wyandotte County, Kansas) monitors have been recorded in the EPA's Air Quality System (AQS), and the data meets the requirements of appendix T to 40 CFR part 50 and 40 CFR part 58. This data suggests improved air quality in both areas. As shown below in table 1, the 99th percentile 1-hour average (in ppb) and 3-year dv at the Troost and JFK monitors has decreased since 2013 and do not show violations of the 2010 1-hr primary SO₂ NAAQS. The certified 3-year 2016-2018 dv for the Jackson County area is 11 ppb; the certified 3-year 2016-2018 dv for the Wyandotte County area is 7 ppb.

However, MoDNR did not submit a demonstration showing that the Troost monitor is in the area of maximum concentration. Thus, the monitoring data on its own is not enough to support a clean data determination in this case, and, as such, the MoDNR submitted modeling to support the clean data determination.

Table 1—99th Percentile 1-Hour Average in Parts Per Billion (ppb) and 3-Year Design Value at the Troost and JFK Monitors

[2013-2018]

Monitor	Site name	2013	2014	2015	2016	2017	2018	2016-2018 design value
29-095-0034	Troost	156	125.2	142	9.4	18.4	6.1	11
20-209-0021	JFK	45	55.1	37.6	9.6	5.5	6.1	7

B. Jackson County Clean Data Modeling

As noted earlier, the 2014 SO₂ Guidance states that, for the EPA to make a clean data determination, the State may need to submit information in addition to monitoring data if the area was designated nonattainment based on air quality monitoring data. In June 2019, the MoDNR submitted the Jackson County clean data determination modeling and updated the modeling information in February 2020.^[45] The EPA reviewed the modeling data to determine consistency with the EPA's Clean Data Policy, the 2014 SO₂ Guidance, and the August 2016 SO₂ Modeling TAD. The EPA reviewed the submittal to determine if the appropriate meteorological data, background concentration, building downwash data, source characteristics, and emissions data were utilized.

i. Meteorological Data

The MoDNR elected to use the most recent three-year period (2016-2018) of meteorological data as measured at a spatially and temporally representative National Weather Service airport site. The MoDNR utilized the Kansas City Downtown Airport (KC Airport), which is located less than 1 kilometer to the north of the nonattainment area and provides similar land-use and meteorological characteristics for surface data, and the Topeka Regional Airport (Topeka Airport) site for upper air data. The meteorological data from the time period of 2016-2018 was processed using AERMET (version 18081), with the ADJ_U* option, and paired with the emissions data as discussed below using the AERMOD modeling system.^[46 47] Although appendix W and the 2014 SO₂ Guidance suggest that a state use five years of meteorological data from an NWS site, the August 2016 Modeling TAD suggests that at a minimum a state should utilize three years of meteorological data. Because a clean data determination for the 1-hr SO₂ NAAQS would look at monitoring data over a 3-year timeframe, the EPA is proposing to determine that the utilization of three years of meteorological data from these sites was sufficient for the clean data determination modeling demonstration.

ii. Background Concentration

The MoDNR used 2016-2018 SO₂ monitoring data from the JFK air quality monitor paired with wind direction data from the KC Airport to determine the appropriate background concentration. The MoDNR utilized the Openair package within the R-software to plot monitored 1-hr SO₂ emissions paired with temporally matching 1-hr wind direction data. The MoDNR determined that the 180 to 260-degree sector of the JFK monitor, represents the area that is the least impacted by emission sources that were explicitly modeled.^[48] The MoDNR obtained all hourly SO₂ monitoring data when winds were blowing from this sector and calculated the 99th percentile of hourly concentrations for each year. However, the State did not use the 99th percentile of yearly maximum hourly daily concentrations in its background sector analysis. The EPA corrected the State's background analysis to fit the form of the 1-hr standard (e.g., 3-yr year average of the 99th percentile of the annual maximum 1-hr daily concentration) and determined that the sector base background would be 3.2 ppb. Table 2 provides the results from this analysis.

Table 2—JFK Monitor's 99th Percentile SO₂ Concentration Within 180-260 Degrees Wind Sectors

Year	180-260 degrees wind sectors 99th percentile concentration (ppb)
2016	4.1
2017	2.9
2018	2.7
Average	3.2

The average of the three-year 99th percentiles (3.2 ppb) was determined to be the appropriate background value. The EPA proposes to determine that the background value of 3.2 ppb is appropriate and comports with appendix W and the 2014 SO₂ Guidance.

iii. Source Characteristics

The EPA reviewed the MoDNR's source characterization used in its modeling demonstration, including source types, stack heights, and stack exit temperatures and velocities. The EPA is proposing to determine MoDNR's source characterization was consistent with the recommendations of appendix W and the 2014 SO₂ Guidance. The State modeled all stacks at their actual stack heights, following the 2014 SO₂ Guidance, which states, “Consistent with previous SO₂ modeling guidance (U.S. EPA, 1994) and section 6.2.2 of appendix W, for stacks with heights that are within the limits of Good Engineering Practice (GEP), actual heights should be used in modeling.” ^[49]

iv. Emissions Data

The MoDNR modeled the 2016-2018 SO₂ emissions for every permitted source of emissions located inside the nonattainment area and within 20 km of the nonattainment area. The MoDNR also modeled a source (KCPL Sibley) located within 50 km of the nonattainment area because its SO₂ emissions were over 1,000 tons/year.

The MoDNR characterized the emissions from the sources in the modeling inventory in three ways: (1) Veolia burning coal or natural gas; (2) sources with CEMS data, and (3) sources without CEMS (other than Veolia).

For the Veolia facility, the MoDNR performed an analysis to temporally allocate its actual emissions during the 2016 and 2017 modeling periods.^[50] The MoDNR asserted that this was necessary to capture the effect of switching from coal to natural gas on EP2, as required by the current operating permit (MO OP2018-006) and a 2016 construction permit (MO 122016-009). The emission inventory questionnaire (EIQ) submitted to the MoDNR by Veolia showed that it was still burning coal in EP2 during a few days in 2016 and 2017, with all other days burning natural gas.^[51] Since the EIQ did not specify the dates when the facility was still burning coal, the MoDNR contacted the facility to obtain those dates with coal usage. The MoDNR temporalized the coal annual emissions to hourly emissions based on those days. For example, during 2017, EP2 operated using coal on nine days and the MoDNR assumed coal combustion on each hour for the nine days (216 hours). The MoDNR divided the 2017 annual emissions (173.90 tons) by 216 hours and multiplied the result by 2,000 to obtain the hourly emissions in pounds per hour (1,610.15 lbs./hour). The MoDNR then created an hourly emission file to account for the coal emissions where each of the 216 hours of 2017 emission year was assigned 202.88 grams per second (grams/sec) and the remaining 8,544 hours were assigned zero grams/sec. In addition, the remaining 8,544 hours of operation for EP2 in 2017 were modeled assuming natural gas combustion (0.30 lb/hr).

For all sources that have CEMS installed, the MoDNR obtained the actual hourly varying SO₂ emissions from EPA's Clean Air Market's Division (CAMD) and modeled those emissions.

For sources without CEMS data, with the exception of Veolia, the MoDNR determined each sources' highest actual annual emissions during years 2016, 2017 and 2018. The MoDNR used the highest annual emissions in the AERMOD input files for years 2016-2018. The MoDNR determined the hourly emissions for each of the modeled source facilities by dividing its highest annual emissions by the number of actual operational hours to determine a representative operational emission rate. The MoDNR then used this operational hourly emission rate as the emission input for all hours of the year for the three-year period.^[52] Thus, the State modeled an hourly emission rate even for hours where there were no actual operations. As explained further below, this approach likely models slightly higher total annual emissions than the actual annual emissions.

The EPA is proposing to determine that the modeled source inventory was both created and characterized in accordance with the 2014 SO₂ Guidance and the 2016 SO₂ Modeling TAD. The August 2016 Modeling TAD recommends utilizing hourly CEMS data in modeling analyses for the purpose of designations or clean data determinations. The MoDNR has done this for sources with CEMS. The August 2016 Modeling TAD says that in the absence of CEMS data, simply dividing the annual emissions by the number of hours in the year (8,760) is not an accurate representation of actual emissions for sources that experience emissions rate variability throughout the year and should not be used. The EPA is proposing to determine that by using the highest annual emissions from 2016-2018 for the sources without CEMS, other than Veolia, and then dividing that number by the number of operational hours the hourly emissions input is acceptable. The EPA is proposing that the MoDNR adequately assessed the 2016 and 2017 Veolia emissions on the few days when burning coal and that the characterization of Veolia's 2016-2018 emissions is acceptable. Also, as mentioned above in the “What Are the Criteria to be Redesignated from Unclassifiable to Attainment/Unclassifiable?” section of this document, the EPA has determined that it is appropriate to model a mix of allowable and actual emissions.

v. Results

The maximum modeled impact from the June 19, 2019 Jackson County clean data determination modeling (with the February 2020 correction) was 113.9 μg/m^[3] , or 43.5 ppb.^[53] The modeling scenario with the EPA's adjusted background is 115.1 μg/m³ or 44 ppb, which meets the 1-hour standard of 75 ppb. The maximum modeled impact was located to the southeast of Veolia, caused on the modeled days when coal was combusted at Veolia.

The EPA proposes that the model results, along with monitored values below the NAAQS at the Troost Street monitor for the same time period, satisfies the criteria for clean data according to the EPA's guidance. Certified and quality assured 2018 air quality monitoring data is indicative of a substantial improvement in SO₂ air quality in the nonattainment area; the design value for 2016-2018 is 11 ppb. The MoDNR's monitoring data, technical modeling analysis and supplemental information all support EPA's proposed determination, consistent with its Clean Data Policy, that the nonattainment area has clean data and warrants a determination of attainment.

C. Wyandotte County Redesignation Modeling

As previously noted, the KDHE submitted the BPU March 2016 modeling as an appendix to its January 2017 Round 3 designations submittal. Because the Wyandotte County area was already designated in Round 2, the EPA had no obligation to consider the KDHE's recommendation during Round 3 and instead stated that it would consider the KDHE's request for redesignation in a separate action. This section describes the EPA's review of the BPU March 2016 modeling data submitted to the EPA by the KDHE in January 2017 and the EPA's reasoning for proposing to determine that the Wyandotte County area is attaining the 1-hour SO₂ NAAQS and to redesignate the Wyandotte County area to attainment/unclassifiable. Also as previously noted, the BPU March 2016 modeling was completed in accordance with the December 2013 Modeling TAD.^[54 55]

i.^. Meteorological Data

The BPU March 2016 modeling used AERMOD's meteorological data preprocessor AERMET (version 14134) with 2012-2014 surface meteorological data from the KC Airport (referred to as the Charles B. Wheeler Downtown Airport in the modeling document) and upper air meteorological data from the NWS upper-air balloon station, located in Topeka, Kansas. Although appendix W, the 2014 SO₂ Guidance and the December 2013 Modeling TAD (as well as the August 2016 Modeling TAD) suggest that a state use 5 years of meteorological data from a NWS site (or at least one year of on-site meteorological data) for SIP development, this redesignation is not a redesignation from nonattainment to attainment, therefore no SIP was required from the KDHE for maintenance. The Modeling TAD indicates that for designations a minimum of three years of meteorological data should be used. Redesignations from unclassifiable to attainment/unclassifiable are a factual determination of whether the area is attaining the NAAQS, much like an initial designation. As such, the EPA believes utilization of 3 years of meteorological data from these sites is sufficient for this analysis.

ii. Background Concentration

Upon request from the KDHE, the BPU March 2016 modeling used a 1-hour SO₂ background concentration of 13 ppb. At the time of the BPU model's development, the MoDNR adopted an attainment plan for the Jackson County area (subsequently withdrawn from the EPA). In the now-withdrawn attainment SIP, the MoDNR described its background concentration analysis which it shared with the KDHE. In its background concentration analysis, the MoDNR obtained 2010-2012 monitoring data from the JFK monitor. The MoDNR ran back trajectories using a HYSPLIT model for monitored values above 10 ppb, 15 ppb, and 20 ppb. From the back-trajectory analysis, a sector with little to no influence from Missouri or Kansas SO₂ sources was chosen to represent background concentrations; the sector with the least source influence was at 180-200 degrees. Once a representative sector was a chosen, the highest monitoring values from that sector were evaluated. The 2010-2012 fourth high hourly monitored SO₂ value in the representative sector was 13 ppb. Therefore, a SO₂ concentration of 13 ppb was used as the modeled background concentration for the MoDNR's Jackson County SO₂ area planning purposes, was shared with the KDHE, and used in the BPU March 2016 modeling. A discussion of the background concentrations used in the Jackson County CDD modeling and the BPU March 2016 modeling is provided in the “Connection to the Jackson County Clean Data Modeling” section of this document.

The EPA proposes to determine that the background value of 13.0 ppb is appropriate and comports with appendix W, the 2014 SO₂ Guidance and the Modeling TAD.

iii. Source Characteristics

The EPA reviewed the BPU March 2016 source characterization used in its modeling demonstration, including source types, stack heights, and stack exit temperatures and velocities. The EPA is proposing to determine BPU's source characterization was consistent with the recommendations of appendix W and the 2014 SO₂ Guidance. BPU modeled all stacks at their actual stack heights, following the 2014 SO₂ Guidance, which says, “Consistent with previous SO₂ modeling guidance (U.S. EPA, 1994) and section 6.2.2 of Appendix W, for stacks with heights that are within the limits of Good Engineering Practice (GEP), actual heights should be used in modeling.”

iv. Emissions Data

In the BPU March 2016 model, BPU-Nearman, KCP&L-Sibley EP5A, EP5B and EP5C, and KCP&L-Hawthorn Unit 5 (EP6) were included using 2012-2014 CEMS data. Each of the IPL (Missouri City and Blue Valley) emission points were modeled using their 2013 actual emissions. These 2013 actual emissions reflect coal combustion at IPL-Blue Valley and IPL-Missouri City, and since IPL-Missouri City has shut down and IPL-Blue Valley has switched to natural gas, the EPA proposes to find that the modeled emissions rates based on coal is conservative compared to the most recent three years of actual emissions from natural gas operations and shutdown and can therefore be relied upon in the analysis.

Table 3 provides annual SO₂ emissions for the major point sources in the area. Actual emissions have been reduced in 2018 at every major source compared to the 2012-2014 timeframe used in the BPU 2016 modeling. SO₂ emissions at these major point sources are down 83 percent from the highest emission year of 2013 (28,241 tons per year) to 2018 (4,738 tons per year). In addition, 2013 actual emissions used for modeled emissions at IPL-Blue Valley and IPL-Missouri City are the highest annual emissions at these two sources in the 2012-2018 timeframe. These two sources reported zero SO₂ emissions in 2018. Thus, EPA finds the modeled emissions from 2012-2014 for BPU-Nearman, KCP&L-Sibley EP5A, EP5B and EP5C, KCP&L-Hawthorn EP6 (Unit 5), and the 2013 emissions assuming coal combustion for IPL-Blue Valley and shutdown of IPL-Missouri City acceptable.

In the BPU March 2016 modeling, Veolia emission points EP1, EP2 and EP3 were modeled at 0.50, 351.8 and 0.50 lbs/hr of SO₂, respectively. The modeled Veolia rates are conservative to the permitted requirement to burn natural gas, and the 2016-2018 actual emissions modeled in the Jackson County clean data determination modeling. The EPA is proposing to determine that the emission rates used in the BPU March 2016 modeling comport with the Modeling TAD.

Table 3—Major Individual Point Source SO₂ Emissions (tons per year) in Wyandotte County, Kansas, Jackson County, Missouri and Clay County, Missouri

	2012	2013	2014	2015	2016	2017	2018
Veolia	6,702	7,934	7,782	7,343	25	175	1
Nearman	4,612	4,928	5,333	4,763	2,439	904	1,023
Blue Valley	1,295	1,487	998	229	1	0	0
Sibley	6,095	6,218	4,847	7,630	3,604	4,162	2,616
Hawthorn	1,577	1,728	1,441	1,368	1,043	1,180	1,089
Quindaro	2,758	2,905	3,684	853	27	1	8
Missouri City	684	741	0	723

v. Connection to the Jackson County Clean Data Modeling

A background value of 13 ppb was utilized in the BPU March 2016 modeling and an adjusted background value of 3.2 ppb was used in the Jackson County CDD modeling. Although the background concentrations were determined using the same analysis method (i.e., sector exclusion analysis) the numbers are significantly different. The EPA has found this is likely due to the difference in years used in the analysis, 2012-2014 in the BPU March 2016 modeling vs. 2016-2018 in the Jackson County CDD modeling. The 2016-2018 years reflect a significant reduction in SO₂ emissions in both the Wyandotte and Jackson County areas since 2012. Table 4 shows the total point source SO₂ emission reductions from 2012-2018.

Table 4—Point Source SO₂ Emissions (tons per year) Wyandotte County, Kansas and Jackson County, Missouri

State	County	2012	2013	2014	2015	2016	2017	2018
KS	Wyandotte	7,401	7,860	9,038	5,634	2,481	922	1,051
MO	Jackson	19,115	19,762	16,307	19,673	4,832	5,686	4,282
Total		26,516	27,622	25,345	25,308	7,313	6,608	5,333

The BPU March 2016 model had a receptor grid that included the Jackson County area, as well as portions of Platte and Clay counties in Missouri in addition to Wyandotte County, Kansas.

The BPU March 2016 modeling included all the large SO₂ emitters in Missouri, except for Veolia, at their actual emissions. In some cases, these emissions were much higher than the more recent actual emissions used by the MoDNR in its Jackson County clean data determination modeling. For example, the BPU March 2016 modeling included the IPL-Missouri City emission points at their 2013 actual emissions, however that source has since shut down and, as such, they were not included in the Jackson County clean data determination modeling. BPU-Nearman was included in the BPU March 2016 modeling at its 2012-2014 CEMS rate but was included at a much lower rate, 2016-2018 CEMS rate, in the Jackson County clean data determination modeling.

As previously discussed in this document, during the Round 2 designations, the EPA found that because the BPU March 2016 modeling included Veolia at emission rates that were neither federally enforceable and in effect nor reflective of the facility's most recent three years of actual emissions, it could not rely on the modeling to designate the Wyandotte County area. Subsequently, Missouri issued construction and operating permits to Veolia that limit the emission points to burning natural gas. Therefore, the Veolia emission rates used in the BPU March 2016 modeling are now higher than the maximum emission rates of natural gas combustion and higher than the 2016-2018 actual emission modeled in the Jackson County clean data determination modeling. These actual emissions included periods of time when Veolia was still burning coal—a practice that is no longer permitted. A comparison of the BPU March 2016 modeled emission rates and the Jackson County clean data determination modeled emission rates is given in table 5.

Table 5—Model Input Comparison

Model input	BPU March 2016 model	Jackson County CDD model
AERMOD Version	15181	18081
Meteorological Data	2012-2014	2016-2018
Background concentration	13 ppb	3.2 ppb.
BPU-Nearman	2012-2014 CEMS	2016-2018 CEMS.
Veolia
EP1	0.5 lb/hr	= <0.12 lb/h.
EP2	351.8 lb/hr	= <0.30 lb/hr 1.
EP3	0.5 lb/hr	= <0.30 lb/hr.
IPL Missouri City
EP5	2013 actual 220.4 lb/hr	Shutdown.
EP6	2013 actual 0.1 lb/hr	Shutdown.
IPL Blue Valley
EP3	2013 actual 193.4 lb/hr	0.006 lb/hr.
EP4	2013 actual 224.6 lb/hr	0.004 lb/hr.
EP5	2013 actual 340.3 lb/hr	0.009 lb/hr.
KCP&L Sibley
EP5A	2012-2014 CEMS	2016-2018 CEMS.
EP5B	2012-2014 CEMS	2016-2018 CEMS.
EP5C	2012-2014 CEMS	2016-2018 CEMS.
Hawthorn
EP6	2012-2014 CEMS	2016-2018 CEMS.
Modeling Results	49.24 ppb	43.47 ppb.
1 In addition to this modeled actual SO2 emissions from natural gas, EP2 was also modeled with actual SO2 emissions for the days Boiler 8 burned coal.

With a higher background concentration, higher modeled emissions from both Kansas and Missouri sources, the BPU March 2016 modeling demonstrates that the Wyandotte County area is attaining the standard. The BPU March 2016 modeling also demonstrates that the Wyandotte County area is not contributing to a modeled violation of the NAAQS in the nearby Jackson County area, which, as explained in III.g. “What is the EPA's Rationale for Proposing This Action?”, the EPA is proposing to determine the Jackson County area is currently attaining the standard based on Missouri's June 2019 clean data determination modeling including the Veolia emission points at actual emissions from 2016-2018.

vi. Results

The maximum modeled impact from the BPU March 2016 model scenario, with the 34 μg/m³ (13 ppb) background included, is 163 μg/m³ or 62 ppb which complies with the 1-hour standard of 75 ppb. This maximum modeled concentration is located to the southeast of BPU-Nearman in Wyandotte County, Kansas. The BPU March 2016 modeling as well as the KDHE's monitoring data for the JFK monitoring location, the MoDNR's monitoring data for the Troost monitoring location and the MoDNR's Jackson County clean data determination modeling support the EPA's proposed determination that the area does not contribute to a violation of the NAAQS in the Jackson County area (which the MoDNR has demonstrated is monitoring and modeling attainment of the standard) and warrants a redesignation from unclassifiable to attainment/unclassifiable.

Note: Due to their large size, some or all modeling data files may not be available in the docket (please contact the person identified in the FOR FURTHER INFORMATION CONTACT section of this preamble for more information).

V. When promulgated, what are the effects of this action?

A. Jackson County, Missouri

If the proposed determination is made final, the requirements for the MoDNR to submit an attainment demonstration, a reasonable further progress plan, contingency measures, and other planning SIP revisions related to attainment of the 2010 1-hr primary SO₂ NAAQS in Jackson County shall be suspended until such time, if any, that the EPA subsequently determines, after notice-and-comment rulemaking in the Federal Register, that the area has violated the 2010 1-hr primary SO₂ NAAQS. If this were to occur, the basis for the suspension of the specific SIP requirements would no longer exist, and the State would thereafter have to address the pertinent requirements. If finalized, this determination of attainment would not shield the area from other required actions, such as provisions to address pollution transport, which could require emission reductions at sources or other types of emission activities contributing significantly to nonattainment in other areas or states or interfering with maintenance in those areas. The EPA has the authority to require emissions reductions as necessary and appropriate to deal with transported air pollution situations. See CAA sections 110(a)(2)(D), 110(a)(2)(A), and 126.

If, after considering any comments received on this proposal, the EPA finalizes a clean data determination for this area, the MoDNR would need to continue to monitor and/or model air quality to verify continued attainment. The MoDNR would be expected to continue to operate an appropriate air quality monitoring network in the affected area, in accordance with the EPA regulations, to verify the attainment status of the area (see 40 CFR part 58).

This proposed clean data determination is limited to a determination that the Jackson County area attained the 2010 1-hr primary SO₂ NAAQS as evidenced by the MoDNR's monitoring data and modeling analysis; this proposed determination, if finalized, would not constitute a redesignation to attainment under section 107(d)(3) of the CAA. The designation status of the Jackson County area will remain nonattainment for the 2010 1-hr primary SO₂ NAAQS until such time as the MoDNR submits an approvable redesignation request and maintenance plan, and the EPA takes final rulemaking action to determine that such submission meets the CAA requirements for redesignation to attainment.

B. Wyandotte County, Kansas

If finalized, approval of the redesignation request would change the legal designation of Wyandotte County, found at 40 CFR part 81, from unclassifiable to attainment/unclassifiable for the 2010 1-hr SO₂ NAAQS. The KDHE's SIP obligations are unaffected by this redesignation.

VI. Statutory and Executive Order Reviews

This action proposes to make a determination based on air quality monitoring data and modeling and would, if finalized, result in the suspension of certain Federal requirements and would not impose any additional requirements.

With regard to the redesignation portion of this action, under the CAA, redesignation of an area to attainment/unclassifiable is an action that affects the air quality designation status of geographical areas and does not impose any regulatory requirements. For these reasons, this proposed action:

• Is not a significant regulatory action subject to review by the Office of Management and Budget under Executive Orders 12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
• Is not an Executive Order 13771 (82 FR 9339, February 2, 2017) regulatory action because it is not a significant regulatory action under Executive Order 12866.
• Does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
• Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.);
• Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);
• Does not have Federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999);
• Is not an economically significant regulatory action based on health or safety risks subject to Executive Order 13045 (62 FR 19885, April 23, 1997);
• Is not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, May 22, 2001);
• Is not subject to requirements of the National Technology Transfer and Advancement Act (NTTA) because this rulemaking does not involve technical standards; and
• Does not provide EPA with the discretionary authority to address, as appropriate, disproportionate human health or environmental effects, using practicable and legally permissible methods, under Executive Order 12898 (59 FR 7629, February 16, 1994).

This action does not apply on any Indian reservation land or in any other area where EPA or an Indian tribe has demonstrated that a tribe has jurisdiction. In those areas of Indian country, the action does not have tribal implications and will not impose substantial direct costs on tribal governments or preempt tribal law as specified by Executive Order 13175 (65 FR 67249, November 9, 2000).

List of Subjects

40 CFR Part 52

• Environmental protection
• Air pollution control
• Clean data determination
• Determination of attainment
• Incorporation by reference
• Redesignation
• Reporting and recordkeeping requirements
• Sulfur Dioxide

40 CFR Part 81

• Environmental protection
• Air pollution control

Dated: March 31, 2020.

James Gulliford,

Regional Administrator, Region 7.

For the reasons stated in the preamble, the EPA proposes to amend 40 CFR parts 52 and 81 as set forth below:

PART 52—APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

1. The authority citation for part 52 continues to read as follows:

Authority: 42 U.S.C. 7401 et seq.

Subpart—AA Missouri

2. In § 52.1343, revise paragraph (b) to read as follows:

§ 52.1343

Control strategy: Sulfur dioxide.

* * * * *

(b) Determination of attainment. EPA has determined, as of [date of publication of the final rule in the Federal Register], that the Jackson County 2010 SO₂ nonattainment has attained the 2010 SO₂ 1-hr NAAQS. This determination suspends the requirements for this area to submit an attainment demonstration, associated reasonably available control measures, reasonable further progress, contingency measures, and other plan elements related to attainment of the standards for as long as the area continues to meet the 2010 SO₂ 1-hr NAAQS.

PART 81—DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES

3. The authority citation for part 81 continues to read as follows:

Authority: 42 U.S.C. 7401, et seq.

Subpart C—Section 107 Attainment Status Designations

4. In § 81.317, the table titled “Kansas—2010 Sulfur Dioxide NAAQS [Primary]” is amended by revising the entry “Wyandotte County, KS” to read as follows:

§ 81.317

Kansas.

* * * * *

Kansas—2010 Sulfur Dioxide NAAQS

[Primary]

Designated area 1	Designation
	Date 2	Type
*         *         *         *         *         *         *
Wyandotte County, KS	[Date of publication of the final rule in the Federal Register], [Federal Register citation of the final rule]	Attainment/Unclassifiable.
*         *         *         *         *         *         *
1 Includes any Indian country in each county or area, unless otherwise specified. EPA is not determining the boundaries of any area of Indian country in this table, including any area of Indian country located in the larger designation area. The inclusion of any Indian country in the designation area is not a determination that the state has regulatory authority under the Clean Air Act for such Indian country.
2 This date is April 9, 2018, unless otherwise noted.

* * * * *

Footnotes

1.  In accordance with appendix T to 40 CFR part 50, the 1-hour primary SO₂ NAAQS is met at an ambient air quality monitoring site when the valid 1-hour primary standard design value is less than or equal to 75 parts per billion (ppb). 40 CFR 50.17(b).

2.  In accordance with appendix T to 40 CFR part 50, a 1-hour primary SO₂ NAAQS design value is valid if it encompasses three consecutive calendar years of complete data. A year meets data completeness requirements when all 4 quarters are complete. A quarter is complete when at least 75 percent of the sampling days for each quarter have complete data. A sampling day has complete data if 75 percent of the hourly concentration values, including state-flagged data affected by exceptional events which have been approved for exclusion by the Administrator, are reported.

3.  Monitoring data must be reported, quality assured, and certified in accordance with the requirements set forth in 40 CFR part 58.

4.  Designations for the 2010 1-hr SO₂ NAAQS occurred/will occur in four phases, often referred to as “Rounds”. During Round 2 of the designations process, the EPA used the designation category “unclassifiable/attainment” for areas with air quality monitoring or modeling data demonstrating attainment and for areas for which such data weren't available but for which the EPA had reason to believe the areas were likely attainment and had not been determined to be contributing to nearby violations (see 81 FR 45039, July 12, 2016, page 45041 footnote 3). For Round 3 of the designations process the EPA used the designations category of “attainment/unclassifiable” instead of “unclassifiable/attainment”. The EPA noted that the inversion of the order of the words “attainment” and “unclassifiable” in the amended term “attainment/unclassifiable” had no consequence itself, and that there were no regulatory consequences of the change in, or clarified interpretation of, the terminology applied to the areas to which the terms are applied. For consistency, the EPA also inverted the order of “attainment” and “unclassifiable” for areas previously designated in Round 2 (81 FR 45039, July 12, 2016, and 81 FR 89870, December 13, 2016). The re-ordering of the terms had no regulatory consequence and did not revisit the determinations made in Round 2 for these areas. The EPA found the change was consistent with Congress' definition of “attainment area” in CAA section 107(d)(1)(A)(ii) (see 83 FR 1098, January 9, 2018, page 1099).

5.  See 75 FR 35520, June 22, 2010.

6.  See 78 FR 47191, August 5, 2013, codified at 40 CFR 81.326.

7.  There are four rounds of designations for the 2010 1-hr SO₂ NAAQS. Round 1 was completed in August 2013. Round 2 was completed in July and December 2016. Round 3 was completed in January 2018. Round 4 is to be signed by the Administrator no later than December 31, 2020.

8.  See 84 FR 3703 (February 13, 2019). The EPA published a fnal rulemaking in the Federal Register approving the MoDNR's 172(c)(3) baseline year inventory for the Jackson County area.

9.  The submittal also indicated that a previously significant source of SO₂, the Kansas Board of Public Utilities-Quindaro location, did not need to be included in the supporting modeling because the facility switched to natural gas combustion in its boilers in 2015. The operating permit for the Quindaro facility is provided in the docket to this rulemaking.

10.  See, e.g., Memorandum of December 14, 2004, from Steve Page, Director, EPA Office of Air Quality Planning and Standards to the EPA Air Division Directors, “Clean Data Policy for the Fine Particle National Ambient Air Quality Standards.” This document is available at: http://www.epa.gov/​pmdesignations/​guidance.htm.

11.  The memorandum of April 23, 2014, from Steve Page, Director, EPA Office of Air Quality Planning and Standards to the EPA Air Division Directors “Guidance for 1-hr SO₂ Nonattainment Area SIP Submissions” provides guidance for the application of the clean data policy to the 2010 1-hr primary SO₂ NAAQS. This document is available at https://www.epa.gov/​sites/​production/​files/​2016-06/​documents/​20140423guidance_​nonattainment_​sip.pdf.

12.  See, e.g., 81 FR 58010, 81 FR 58127-81 FR 58129 (August 24, 2016) (promulgating 40 CFR 51.1015); 80 FR 12264, 80 FR 12296 (promulgating 51.1118). See also 70 FR 71612, 70 FR 71664-70 FR 71646 (November 29, 2005); 72 FR 20585, 72 FR 20603-72 FR 20605 (April 25, 2007).

13.  See court cases upholding legal basis for the EPA's Clean Data Determination Policy, NRDC v. EPA, 571 F.3d at 1258-61 (D.C. Cir. 2009); Sierra Club v. EPA, 99 F.3d 1551 (10th Cir. 1996); Latino Issues Forum v. EPA, 315 Fed. App. 651, 652 (9th Cir. 2009).

14.  82 FR 13227 (March 10, 2016) and 81 FR 28718 (May 10, 2016).

15.  As noted in the preamble to the 2010 1-hr primary SO₂ NAAQS (75 FR 35551, June 22 2010), this has been the EPA's general position throughout the history of implementation of the SO₂ NAAQS program. See, e.g., “Air Quality Control Regions, Criteria, and Control techniques; Attainment Status Designations,” 43 FR 40412, 43 FR 40415-43 FR 40416 (September 11, 1978); “Air Quality Control Regions, Criteria, and Control Techniques,” 43 FR 45993, 43 FR 46000-43 FR 46002 (October 5, 1978); “Air Quality Implementation Plans: State Implementation Plans; General Preamble,” 57 FR 13498, 57 FR 13545, 57 FR 13547-57 FR 13557, 57 FR 13548 (April 16, 1992); “Approval and Promulgation of State Implementation Plans; Call for Sulfur Dioxide SIP Revisions for Billings/Laurel, MT,” 58 FR 41430 (August 4, 1993); “Designation of Areas for Air Quality Planning Purposes; Ohio,” 59 FR 12886, 59 FR 12887 (March 18, 1994); “Ambient Air Quality Standards, National and Implementation Plans for Sulfur Oxides (Sulfur Dioxide),” 60 FR 12492, 60 FR 12494-60 FR 12495 (March 7, 1995); “Air Quality Implementation Plans; Approval and Promulgation: Various States: Montana,” 67 FR 22167, 67 FR 22170-67 FR 22171, 67 FR 22183-67 FR 22887 (May 2, 2002).

16.  The EPA released earlier versions, December and May 2013, of both the modeling and monitoring TADs, as well as an earlier February 2016 version of the modeling TAD. The February 2016 version of the “SO₂ NAAQS Designations Source-Oriented Monitoring Draft Technical Assistance Document, Office of Air Quality Planning and Standards, Air Quality Assessment Division”, can be found at https://www.epa.gov/​sites/​production/​files/​2016-06/​documents/​so2monitoringtad.pdf. The August 2016 version of the “SO₂ NAAQS Designations Modeling Technical Assistance Document, Office of Air Quality Planning and Standards, Air Quality Assessment Division”, can be found at https://www.epa.gov/​sites/​production/​files/​2016-06/​documents/​so2modelingtad.pdf. The December 2013 versions of the documents can be found in the docket to this rulemaking.

17.  While CAA section 107(d)(3)(E) also lists specific requirements for redesignations, those requirements apply to redesignations of nonattainment areas to attainment and, therefore, are not applicable here.

18.  See page 10 of the August 2016 SO₂ Modeling TAD.

19.  Essentially, the MoDNR estimated days in 2016 and 2017 when a primary facility in the nonattainment area (Veolia) was burning coal in conjunction with monitored values at the design value monitor (Troost) instead of providing the actual days when the facility was burning coal. Additionally, the EPA had concerns with the background concentration of 13 parts per billion as described in the analysis and the list of sources included with actual emissions.

20.  The MoDNR updated the background concentration analysis to include actual days (not estimated days) that Veolia was burning coal in 2016 and 2017.

21.  As previously mentioned, the MoDNR submitted modeling on February 24, 2020 to correct the modeled actual emissions at three sources (Audubon Materials, Blue River Treatment Plant and KCPL Northeast Station). The February 24, 2020 modeling did not change the maximum modeled results from the June 19, 2019 modeling submittal. The February 2020 correction modeling data is included in the docket to this rulemaking.

22.  The modeling was performed by Trinity Consultants for the Board of Public Utilities utilizing the December 2013 version of the Modeling TAD.

23.  The highest modeled concentration of SO₂ was 160 μg/m3. (61 ppb).

24.  Trinity Consultants prepared the revised modeling BPU March 2016 modeling utilizing the December 2013 Modeling TAD.

25.  The EPA's TSD for its Round 3 designations can be found at: https://www.epa.gov/​sites/​production/​files/​2017-08/​documents/​1_​2_​rd3-final.pdf.

26.  The EPA is utilizing the most current ambient monitoring data at the Troost monitor to support this action. The State's request was based on 2015-2017 data.

27.  The MoDNR also included KCP&L-Sibley, a source that is 50 km from the area, in the modeling at its most recent three years of actual emissions because it is a source of SO₂ emissions that may impact concentration gradients in the area.

28.  See section IV.b. Jackson County Clean Data Determination for more information regarding the EPA's adjusted background concentration value and impacts to the modeled maximum impact results.

29.  See 81 FR 10563, February 16, 2016.

30.  There are several discrepancies in reference to which emission points (EPs) were modeled. A comparison of the EPs in the September 2015 modeling, the BPU March 2016 modeling, the comments submitted by BPU during the Round 2 designations process and the EPA's Round 2 final designations TSD and MoDNR permits don't all match. For example, the modeling protocol (appendix A) for the September 2015 modeling indicates that EPs at IPL Blue Valley would be included in the model but the modeling results (appendix B) don't include those EPs. Appendix A indicates Veolia EP2 (Boilers 6 and 8) only would be modeled, but appendix B indicates EP1 (Boiler 1A), EP2 (Boilers 6 and 8) and EP3 (Boiler 7) were modeled. Also, Hawthorn's Unit 5 (EP6) was referred to as Unit 6 in the EPA's Round 2 designations proposal TSD. This is believed to be a typographical error and the TSD should have referred to Unit 5 instead. Additionally, Unit 5 (EP6) is referred to as EU0010 in Hawthorn's 2017 title V operating permit.

31.  Trinity Consultants prepared the revised modeling BPU March 2016 modeling utilizing the December 2013 Modeling TAD.

32.  The BPU March 2016 modeling indicates that Veolia EP1, EP2 and EP3 were modeled at “federally enforceable SIP limits.” Trinity Consultants got the limits from a 2015 state rule—10 CSR 10-6.261 Control of Sulfur Dioxide Emissions, but that rule was not SIP approved when the modeling was submitted to the EPA. However, a 2013 operating permit, operating permit# OP2012-050, required EP1 and EP3 to burn natural gas with fuel oil as a back-up and limited EP2 to burn coal, natural gas and fuel oil as a back-up. A 2016 construction permit, construction permit# 122016-09, removed fuel oil as a back-up for EP1 and required EP2 to burn natural gas only as well. The “Project Description/Emissions Calculations” section of the construction permit states that the “entire installation” had not burned fuel oil since 2001. In 2018, the MoDNR issued Veolia a revised operating permit, operating permit# OP2018-06, which included EP3's removal of fuel-oil as a back-up, stating that the unit was to burn natural gas exclusively.

33.  In 2015, Missouri's rule included limits for Veolia EP1, EP2 and E3. The State submitted 10 CSR 10-6.261 to the EPA for approval into the SIP in October 2015, then withdrew the rule in April 2018 and revised it, removing Veolia (and limits for other sources) from the rule. The state resubmitted the rule for the EPA's approval in 2019. At the time of this document, the EPA has not acted on the State's request to approve the revised rule into the SIP.

34.  https://dnr.mo.gov/​env/​apcp/​permits/​docs/​veolia-kc2016cp.pdf.

35.  The MoDNR reviewed Veolia's combustion of coal in 2016 and 2017 for compliance with the December 2016 construction permit. The permit effective date was December 21, 2016, however, it's unclear from the permit if the requirement to burn natural gas only came into effect on the effective date of the permit or the date the work specified in the permit was complete, which was January 2018. In addition, the MoDNR gave Veolia a one-year extension of the compliance date with the Boiler MACT which allowed them to burn coal until the end of January 2017. The record indicates that no coal was burned after January of 2017.

36.  https://dnr.mo.gov/​env/​apcp/​permits/​docs/​veolia-kc2018op.pdf.

37.  It should be noted that construction permit #122016-06 indicates that fuel oil had not been burned installation wide since 2011.

38.  As noted in the “Connection to the Jackson County Clean Data Modeling” secion of this document, in the BPU 2016 modeling, the emissions from EP3 were modeled conservatively compared to the most recent three years of actual emissions (i.e. at a higher emissions rate), at a rate of 0.5 lb/hr. The Jackson County clean data determination modeling included EP3 at its actual emissions, which corresponded to modeling rates of 0.3 lb/hr, 0.3 lb/hr, and 0.1 lb/hr for 2016, 2017, and 2018, respectively. Thus, EPA can rely on the 2016 BPU modeling to determine that the Wyandotte County area is meeting the NAAQS since the BPU modeling used an hourly modeled rate greater than the hourly rate based on actual emissions from the three most recent years.

39.  With the required burning of natural gas, Veolia' facility wide potential to emit is 4.66 tons per year of SO₂.

40.  IPL-Blue Valley Station ceased coal combustion in EP5 (Unit 3) as of 4/15/2015 and in EP3 (Unit 1) and EP4 (Unit 2) as of 9/9/2015.

41.  MoDNR issued Title V operating permit number OP2017-27 (hereinafter referred to as “OP2017-27”) to IPL-Blue Valley on March 28, 2017. The permit limits the fuel to natural gas only with fuel oil backup for EP3, EP4 and EP5.

42.  In a letter dated December 24, 2014, the MoDNR told IPL-Blue Valley that it recommended the coal handling equipment be dismantled or otherwise permanently disabled upon the cease firing of coal, such that coal cannot be fired. The installation should report the nature and extent of the actions performed and their date. The letter states that even if coal handling equipment was not rendered inoperable, a construction permit would be required prior to firing coal. The installation's coal delivery contract expires December 31, 2014 and there are no plans to renew it.

43.  The title V Operating Permit for IPL-Missouri City was terminated on January 31, 2018. In the event IPL-Missouri were to try and start operation, they would need to submit a major New Source Review permit application.

44.  The 2016 TAD update addressed receptor exclusion and clarified that, at minimum, 3 years of meteorological data and emissions data need to be modeled. Both these changes do not affect the BPU modeling.

45.  The MoDNR's submittal included 2016-2018 emissions data. The submittal includes tables of the sources included in the model and the emission rates used in the model. This information is provided in the docket.

46.  The MoDNR used AERMOD version 18081, the most recent version of AERMOD with ADJ_U*, which is a regulatory option for version 18081.

47.  See the state's modeling demonstration, provided in the docket to this action, for model selection information (i.e., receptor grid selection).

48.  Given the locations/distribution of the sources that were explicitly modeled, 180-260 is an acceptable range to ensure the monitor is least impacted by the modeled sources. A 90-degree sector is used to determine the area of impact on a source. Given the location of BPU-Nearman to the NE of the JFK monitor and numerous sources to the SE of the monitor, the 180-260 sector to determine background is appropriate.

49.  U.S. EPA, 1994: SO₂ Guideline Document. EPA-452/R-95-008. U.S. Environmental Protection Agency, Research Triangle Park, NC 27711.

50.  Veolia is not required to operate a CEMS.

51.  As previously mentioned, the MoDNR reviewed Veolia's combustion of coal in 2016 and 2017 for compliance with the December 2016 construction permit. The permit effective date was December 21, 2016, however, it's unclear from the permit if the requirement to burn natural gas only came into effect on the effective date of the permit or the date the work specified in the permit was complete, which was January 2018. In addition, the MoDNR gave Veolia a one-year extension of the compliance date with the Boiler MACT which allowed them to burn coal until the end of January 2017. The record indicates that no coal was burned after January of 2017.

52.  During the EPA's review of modeling files submitted with the June 19, 2019 Jackson County clean data determination submittal, it noticed that the files did not reflect the State's narrative of using the highest annual emissions from 2016-2018. In February 2020, the State submitted corrected emissions files. The June 2019 and the February 2020 emission files are available in the docket to this rulemaking.

53.  MoDNR submitted modeling on February 24, 2020 to correct the modeled actual emissions at threes sources (Audubon Materials, Blue River Treatment Plant and KCPL Northeast Station). The February 24, 2020 modeling did not change the maximum modeled results from the June 19, 2019 modeling submittal.

54.  A side-by-side comparison of the December 2013 and August 2016 Modeling TADs is available in the docket to this rulemaking. The August 2016 version identifies that the Data Requirements Rule was finalized, and that the EPA proposed to revise Appendix W, among other changes.

55.  The BPU March 2016 modeling was performed using AERMOD version 15181 which was the most recent version of AERMOD when the state initited the modeling analysis during Round 2. The EPA has issued three updated versions of AERMOD (version 19191 is the latest), but the model bug fixes and enhancements since the 15181 version are not expected to change the results of the modeling conducted with AERMOD version 15181.