Source: https://www.federalregister.gov/documents/2011/07/13/2011-17467/approval-and-promulgation-of-implementation-plans-mississippi-110a1-and-2-infrastructure
Timestamp: 2017-10-22 12:16:47
Document Index: 613501337

Matched Legal Cases: ['§\u2009110', '§\u2009110', 'art 51', 'art 51', 'art 51', 'art 51', 'art 52', 'art 52', 'art 51', 'art 51', 'art 51', 'art 5', 'art 51', 'art 51', 'art 52', 'art 51', 'art 52', 'art 51', 'art 51']

Federal Register :: Approval and Promulgation of Implementation Plans; Mississippi; 110(a)(1) and (2) Infrastructure Requirements for the 1997 8-Hour Ozone National Ambient Air Quality Standards
76 FR 41123
41123-41135 (13 pages)
EPA-R04-OAR-2010-0722-201125 FRL-9436-6
2011-17467
https://www.federalregister.gov/d/2011-17467 https://www.federalregister.gov/d/2011-17467
EPA is taking final action to approve the December 7, 2007, submission by the State of Mississippi, through the Mississippi Department of Environmental Quality (MDEQ) as demonstrating that the State meets the implementation plan (SIP) requirements of sections 110(a)(1) and (2) of the Clean Air Act (CAA or the Act) for the 1997 8-hour ozone national ambient air quality standards (NAAQS). Section 110(a) of the CAA requires that each state adopt and submit a SIP for the implementation, maintenance, and enforcement of each NAAQS promulgated by the EPA, which is commonly referred to as an “infrastructure” SIP. Mississippi certified that the Mississippi SIP contains provisions that ensure the 1997 8-hour ozone NAAQS is implemented, enforced, and maintained in Mississippi (hereafter referred to as “infrastructure submission”). Mississippi's infrastructure submission, provided to EPA on December 7, 2007, addressed all the required infrastructure elements for the 1997 8-hour ozone NAAQS. Additionally, EPA is responding to adverse comments received on EPA's March 17, 2011, proposed approval of Mississippi's December 7, 2007, infrastructure submission.
EPA has established a docket for this action under Docket Identification No. EPA-R04-OAR-2010-0722. All documents in the docket are listed on the http://www.regulations.gov Web site. Although listed in the index, some information is not publicly available, i.e., Confidential Business Information or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available either electronically through http://www.regulations.gov or in hard copy at the Regulatory Development Section, Air Planning Branch, Air, Pesticides and Toxics Management Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street, SW., Atlanta, Georgia 30303-8960. EPA requests that if at all possible, you contact the person listed in the FOR FURTHER INFORMATION CONTACT section to schedule your inspection. The Regional Office's official hours of business are Monday through Friday, 8:30 to 4:30 excluding Federal holidays.
Upon promulgation of a new or revised NAAQS, sections 110(a)(1) and (2) of the CAA require states to address basic SIP requirements, including emissions inventories, monitoring, and modeling to assure attainment and maintenance for that new NAAQS. On July 18, 1997, EPA promulgated a new NAAQS for ozone based on 8-hour average concentrations, thus states were required to provide submissions to address sections 110(a)(1) and (2) of the CAA for this new NAAQS. Mississippi provided its infrastructure submission for the 1997 8-hour ozone NAAQS on Start Printed Page 41124December 7, 2007. On March 17, 2011, EPA proposed to approve Mississippi's December 7, 2007, infrastructure submission for the 1997 8-hour ozone NAAQS. See 76 FR 14631. A summary of the background for today's final action is provided below. See EPA's March 17, 2011, proposed rulemaking at 76 FR 14631 for more detail.
More specifically, section 110(a)(1) provides the procedural and timing requirements for SIPs. Section 110(a)(2) lists specific elements that states must meet for “infrastructure” SIP requirements related to a newly established or revised NAAQS. As mentioned above, these requirements include SIP infrastructure elements such as modeling, monitoring, and emissions inventories that are designed to assure attainment and maintenance of the NAAQS. The requirements that are the subject of this final rulemaking are listed below [1] and in EPA's October 2, 2007, memorandum entitled “Guidance on SIP Elements Required Under Section 110(a)(1) and (2) for the 1997 8-Hour Ozone and PM2.5 National Ambient Air Quality Standards.”
EPA intended the statements in the proposals concerning these four issues merely to be informational, and to provide general notice of the potential existence of provisions within the existing SIPs of some states that might require future corrective action. EPA did not want states, regulated entities, or members of the public to be under the misconception that the Agency's approval of the infrastructure SIP submission of a given state should be interpreted as a reapproval of certain types of provisions that might exist buried in the larger existing SIP for such state. Thus, for example, EPA explicitly noted that the Agency believes that some states may have existing SIP-approved SSM provisions that are contrary to the CAA and EPA policy, but that “in this rulemaking, EPA is not proposing to approve or disapprove any Start Printed Page 41125existing State provisions with regard to excess emissions during SSM of operations at facilities.” EPA further explained, for informational purposes, that “EPA plans to address such State regulations in the future.” EPA made similar statements, for similar reasons, with respect to the director's discretion, minor source NSR, and NSR Reform issues. EPA's objective was to make clear that approval of an infrastructure SIP for these ozone and PM2.5 NAAQS should not be construed as explicit or implicit reapproval of any existing provisions that relate to these four substantive issues.
Given the potential ambiguity of the statutory language of section 110(a)(1) and (2), EPA believes that it is appropriate for EPA to interpret that language in the context of acting on the infrastructure SIPs for a given NAAQS. Because of the inherent ambiguity of the list of requirements in section 110(a)(2), EPA has adopted an approach in which it reviews infrastructure SIPs against this list of elements “as applicable.” In other words, EPA assumes that Congress could not have intended that each and every SIP submission, regardless of the purpose of the submission or the NAAQS in question, would meet each of the requirements, or meet each of them in the same way. EPA elected to use guidance to make recommendations for infrastructure SIPs for these NAAQS.
EPA believes that this approach to the infrastructure SIP requirement is reasonable, because it would not be feasible to read sections 110(a)(1) and (2) to require a top to bottom, stem to stern, review of each and every provision of an existing SIP for purposes of assuring that the State in question has the basic structural elements for a functioning SIP for a new or revised NAAQS. Because SIPs have grown by accretion over the decades as statutory and regulatory requirements under the CAA have evolved, they may include some outmoded provisions and historical artifacts that, while not fully up to date, nevertheless may not pose a significant problem for the purposes of “implementation, maintenance, and enforcement” of a new or revised NAAQS when EPA considers the overall effectiveness of the SIP. To the contrary, EPA believes that a better approach is for EPA to determine which specific SIP elements from section 110(a)(2) are applicable to an infrastructure SIP for a given NAAQS, and to focus attention on those elements that are most likely to need a specific SIP revision in light of the new or revised NAAQS. Thus, for example, EPA's 2007 Guidance specifically directed states to focus on the requirements of section 110(a)(2)(G) for the 1997 PM2.5 NAAQS because of the absence of underlying EPA regulations for emergency episodes for this NAAQS and an anticipated absence of relevant provisions in existing SIPs.
Finally, EPA believes that its approach is a reasonable reading of sections 110(a)(1) and (2) because the statute provides other avenues and mechanisms to address specific substantive deficiencies in existing SIPs. These other statutory tools allow the Start Printed Page 41127Agency to take appropriate tailored action, depending upon the nature and severity of the alleged SIP deficiency. Section 110(k)(5) authorizes EPA to issue a “SIP call” whenever the Agency determines that a state's SIP is substantially inadequate to attain or maintain the NAAQS, to mitigate interstate transport, or otherwise to comply with the CAA.[15] Section 110(k)(6) authorizes EPA to correct errors in past actions, such as past approvals of SIP submissions.[16] Significantly, EPA's determination that an action on the infrastructure SIP is not the appropriate time and place to address all potential existing SIP problems does not preclude the Agency's subsequent reliance on provisions in section 110(a)(2) as part of the basis for action at a later time. For example, although it may not be appropriate to require a state to eliminate all existing inappropriate director's discretion provisions in the course of acting on the infrastructure SIP, EPA believes that section 110(a)(2)(A) may be among the statutory bases that the Agency cites in the course of addressing the issue in a subsequent action.[17]
EPA is taking final action to approve Mississippi's infrastructure submission as demonstrating that the State meets the applicable requirements of sections 110(a)(1) and (2) of the CAA for the 1997 8-hour ozone NAAQS. Section 110(a) of the CAA requires that each state adopt and submit a SIP for the implementation, maintenance, and enforcement of each NAAQS promulgated by the EPA, which is commonly referred to as an “infrastructure” SIP. Mississippi, through MDEQ, certified that the Mississippi SIP contains provisions that ensure the 1997 8-hour ozone NAAQS is implemented, enforced, and maintained in Mississippi.
Mississippi's infrastructure submission, provided to EPA on December 7, 2007, addressed all the required infrastructure elements for the 1997 8-hour ozone NAAQS. EPA has determined that Mississippi's December 7, 2007, infrastructure submission is consistent with section 110 of the CAA. Additionally, EPA is responding to adverse comments received on EPA's March 17, 2011, proposed approval of Mississippi's December 7, 2007, infrastructure submission. The responses to comments are found in Section IV below.
EPA received one set of comments on the March 17, 2011, proposed rulemaking to approve Mississippi's December 7, 2007, infrastructure submission as meeting the requirements of sections 110(a)(1) and (2) of the CAA for the 1997 8-hour ozone NAAQS. Generally, the Commenter's concerns relate to whether EPA's approval of Mississippi's December 7, 2007, infrastructure submission is in compliance with section 110(l) of the CAA, and whether EPA's approval will interfere with the State's compliance with the CAA's prevention of significant deterioration (PSD) requirements. A full set of the comments provided on behalf of the Kentucky Environmental Foundation (hereinafter referred to as “the Commenter”) is provided in the docket for today's final action. A summary of the comments and EPA's responses are provided below.
Comment 1: Under the header “No Clean Air Act Section 110(l) analysis,” the Commenter states, “Before providing the technical analysis for why finalizing this proposed rule would be contrary to the Clean Air Act, I wish to point out that it is 2011 and EPA has yet to ensure that these areas have plans to meet the 1997 National Ambient Air Quality Standard (NAAQS) for ozone.” The Commenter goes on to state that “EPA acknowledged that the science indicates that the 1997 NAAQS, which is effectively 85 parts per billion (ppb), does not protect people's health or welfare when in 2008, EPA set a new ozone NAAQS at 75 ppb.”
Response 1: As noted in EPA's proposed rulemaking on Mississippi's December 7, 2007, infrastructure submission and in today's final rulemaking, the very action that EPA is undertaking is a determination that Mississippi has a plan to ensure compliance with the 1997 8-hour ozone NAAQS. Mississippi's submission was provided on December 7, 2007, for the 1997 8-hour ozone NAAQS, thus the State's submission predates the release of the revision to the 8-hour ozone NAAQS on March 12, 2008, and is distinct from any plan that Mississippi would have to provide to ensure compliance of the 2008 NAAQS. This action is meant to address, and EPA is approving, the 1997 ozone infrastructure requirements under section 110 of the Act. In today's action EPA is not addressing the 110 infrastructure requirements for the 2008 ozone NAAQS as they will be addressed in a separate rulemaking.
EPA notes that the 1997 8-hour ozone standard as published in a July 18, 1997, final rulemaking notice (62 FR 38856) and effective September 18, 1997, are 0.08 parts per million (ppm), which is effectively 0.084 ppm or 84 ppb due to the rounding convention and not “effectively 85 parts per billion (ppb)” as the Commenter stated. Further, EPA agrees that the Agency has made the determination that the 1997 8-hour ozone NAAQS is not as protective as needed for public health and welfare, and as the Commenter mentioned, the Agency established a new ozone NAAQS at 75 ppb. However, the Agency is currently reconsidering the 2008 8-hour ozone NAAQS, and has not yet designated areas for any subsequent NAAQS.
Finally, while it is not clear which areas the Commenter refers to in stating “EPA has yet to ensure these areas have plans to meet” the 1997 ozone NAAQS, EPA believes this concern is addressed by the requirements under section 172, Part D, Title I of the Act for states with nonattainment areas for the 1997 ozone NAAQS to submit nonattainment plans. As discussed in EPA's notice proposing approval of the Mississippi infrastructure SIP, submissions required by section 110(a)(2)(I) which pertain to the nonattainment planning requirements of part D, Title I of the CAA are outside the scope of this action, as such plans are not due within three years after promulgation of a new or revised NAAQS, but rather are due at the time the nonattainment area plan requirements are due pursuant to section 172.[18]
Start Printed Page 41128
EPA has consistently interpreted section 110(l) as not requiring a new attainment demonstration for every SIP submission. The following actions are examples of where EPA has addressed 110(l) in previous rulemakings: 70 FR 53, 57 (January 3, 2005); 70 FR 17029, 17033 (April 4, 2005); 70 FR 28429, 28431 (May 18, 2005); and 70 FR 58119, 58134 (October 5, 2005). Mississippi's December 7, 2007, infrastructure submission does not revise or remove any existing emissions limit for any NAAQS, or any other existing substantive SIP provisions relevant to the 1997 8-hour ozone NAAQS. Simply put, it does not make any substantive revision that could result in any change in emissions. As a result, the submission does not relax any existing requirements or alter the status quo air quality. Therefore, approval of Mississippi's December 7, 2007, infrastructure submission will not interfere with attainment or maintenance of any NAAQS.
Response 3: Please see Response 2 for a more detailed explanation regarding EPA's response to the Commenter's assertion that EPA's action is not in compliance with section 110(l) of the CAA. EPA does not agree with the Commenter's assertion that EPA's analysis did not consider section 110(l) and so therefore “EPA must approve in part and disapprove in part these action and re-propose to approve the disapproved part with a Clean Air Act § 110(l) analysis.” Every action that EPA takes to approve a SIP revision is subject to section 110(l) and thus EPA's consideration of whether a state's submission “would interfere with any applicable requirement concerning attainment and reasonable further progress * * *, or any other applicable requirement of this chapter” is inherent in EPA's action to approve or disapprove a submission from a state. In the “Proposed Action” section of the March 17, 2011, rulemaking, EPA notes that “EPA is proposing to approve Mississippi's infrastructure submission for the 1997 8-hour ozone NAAQS because this submission is consistent with section 110 of the CAA.” Section 110(l) is a component of section 110, so EPA believes that this provides sufficient notice that EPA considered section 110(l) for the proposed action and concluded that section 110(l) was not violated.
Further, EPA does not agree with the Commenter's assertion that the Agency cannot provide additional clarification in response to a comment concerning section 110(l) and take a final approval action without “providing the public with an opportunity to comment on EPA's Clean Air Act § 110(l) analysis.” Clearly such a broad proposition is incorrect where the final rule is a logical outgrowth of the proposed rule. In fact, the proposition that providing an analysis for the first time in response to a comment on a rulemaking per se violates the public's opportunity to comment has been rejected by the DC Circuit Court of Appeals. See Int'l Harvester Co. v. Ruckelshaus, 478 F.2d 615, 632 n.51 (DC Cir. 1973).
Finally, as previously mentioned, EPA's approval of Mississippi's December 7, 2007, infrastructure submission does not make any substantive revision that could result in any change in emissions, so there is no further “analysis” beyond whether the state has adequate provisions in its SIP to address the infrastructure requirements for the 1997 8-hour ozone NAAQS. EPA's March 17, 2011, proposed rulemaking goes through each of the relevant infrastructure requirements and provides detailed information on how Mississippi's SIP addresses the relevant infrastructure requirements. Beyond making a general statement indicating that Mississippi's submission is not in compliance with section 110(l) of the CAA, the Commenter does not provide comments on EPA's detailed analysis of each infrastructure requirement to indicate that Mississippi's infrastructure submission for the 1997 8-hour ozone NAAQS is deficient in meeting these individual requirements. Therefore, the Commenter has not provided a basis to question the Agency's determination that Mississippi's December 7, 2007, infrastructure submission meets the requirements for the infrastructure submission for the 1997 8-hour ozone NAAQS, including section 110(l) of the CAA.
Response 4: EPA disagrees with the Commenter's statement that EPA's analysis must conclude that this proposed action would be in violation of section 110(l) if finalized. As mentioned above, Mississippi's December 7, 2007, infrastructure submission does not revise or remove any existing emissions limit for any NAAQS, nor does it make any substantive revision that could result in Start Printed Page 41129any change in emissions. EPA has concluded that Mississippi's December 7, 2007, infrastructure submission does not relax any existing requirements or alter the status quo air quality. Therefore, approval of Mississippi's December 7, 2007, infrastructure submission will not interfere with attainment or maintenance of any NAAQS. See Response 2 and Response 3 above for a more detailed discussion.
EPA also disagrees with the specific example provided by the Commenter that the section 110(a)(2)(J) requirement for public notification for the 1997 8-hour ozone NAAQS based on 85 ppb interferes with a public notification program that should exist for a 75 ppb ozone level, and “EPA would be condoning the states providing information that can physical[ly] hurt people.” As noted in Response 1, Mississippi's December 7, 2007, infrastructure submission was provided to address the 1997 8-hour ozone NAAQS and was submitted prior to EPA's promulgation of the 2008 8-hour ozone in March 2008. Thus, Mississippi provided sufficient information at that time to meet the requirement for the 1997 8-hour ozone NAAQS which is the subject of this action.
Finally, EPA notes that members of the public do get information related to the more recent NAAQS via the Air Quality Index (AQI) for ozone. When EPA promulgated the 2008 NAAQS, (73 FR 16436, March 27, 2008) EPA revised the AQI for ozone to show that at the level of the 2008 ozone NAAQS the AQI is set to 100, which indicates unhealthful ozone levels. It is this revised AQI that EPA uses to both forecast ozone levels and to provide notice to the public of current air quality. The EPA AIRNOW system uses the revised AQI as its basis for ozone. In addition, when Mississippi forecasts ozone and provides real-time ozone information to the public, either through the AIRNOW system or through its own Internet based system, the State uses the revised ozone AQI keyed to the 2008 revised ozone NAAQS. EPA believes this should address the Commenter's legitimate assertion.
Response 5: EPA believes that this comment gives no basis for concluding that approval of the Mississippi infrastructure SIP violates the requirements of section 110(l). EPA assumes that the comment refers to the requirement that owners and operators of sources subject to PSD demonstrate that the allowable emissions from the proposed source or emission increases from a proposed modification, in conjunction with all other applicable emissions increases or reductions (including secondary emissions) will not cause or contribute to a violation of any NAAQS. 40 CFR 51.166(k)(1).
EPA further assumes that the Commenter's statement “if a SIP provides an ozone NAAQS of 85 ppb for PSD purposes” refers to a hypothetical SIP-approved PSD program that only requires owners and operators of sources subject to PSD to make the demonstration discussed above for the 1997 ozone NAAQS, and not for the 2008 ozone NAAQS. However, the Commenter gives no indication that Mississippi's SIP-approved PSD program suffers from this alleged defect. EPA has examined the relevant provision in Mississippi's SIP, Regulation APC-S-5—Regulations for the Prevention of Significant Deterioration for Air Quality, and has determined that it satisfies the requirements of 51.166(k)(1) as the State has incorporated by reference 51.166 in its entirety.
Furthermore, as discussed in detail above, the infrastructure SIP makes no substantive change to any provision of Mississippi's SIP-approved PSD program, and therefore does not violate the requirements of section 110(l). Had Mississippi submitted a SIP revision that substantively modified its PSD program to limit the required demonstration to just the 1997 ozone NAAQS, then the comment might have been relevant to a 110(l) analysis of that hypothetical SIP revision. However, in this case, the comment gives no basis for EPA to conclude that the Mississippi infrastructure SIP would interfere with any applicable requirement of the Act.
EPA concludes that approval of Mississippi's December 7, 2007, infrastructure submission will not make the status quo air quality worse and is in fact consistent with the development of an overall plan capable of meeting the Act's requirements. Accordingly, when applying section 110(l) to this submission, EPA finds that approval of Mississippi's December 7, 2007, infrastructure submission is consistent with section 110 (including section 110(l)) of the CAA.
Comment 6: The Commenter provided comments on opposing the proposed approval of the infrastructure submission because it did not identify a specific model to be used to demonstrate that a PSD source will not cause or contribute to a violation of the ozone NAAQS. Specifically, the commenter stated: “[t]he SIP submittals do not comply with Clean Air Act 110(a)(2)(J), (K), and (D)(i)(II) because the SIP submittals do not identify a specific model to use in PSD permitting to demonstrate that a proposed source of modification will not cause or contribute to a violation [or] the ozone NAAQS.”
The commenter asserted that because EPA does not require the use of a specific model, states use no modeling or use deficient modeling to evaluate these impacts. Specifically, the commenter alleged: “Many states abuse this lack of an explicitly named model by claiming that because no model is explicitly named, no modeling is required or use of completely irrelevant modeling (e.g. Kentucky using modeling from Georgia for the J.K. Smith proposed facility) is allowed.”
4. Exhibit 4: Letter from Richard A. Wayland, Director of the Air Quality Start Printed Page 41130Assessment Division, EPA Office Air Quality and Planning Standards to Robert Ukeiley regarding Mr. Ukeiley's Freedom of Information Act (FOIA) request on behalf of the Sierra Club for documents related to EPA development of a modeling protocol for PM2.5 (October 1, 2008);
11. Exhibit 11: Letter from Carl E. Edlund, P.E., Director, EPA, Region 6 Multimedia Planning and Permitting Division to Richard Hyde, P.E. Deputy Director of the Office of Permitting and Registration, Texas Commission on Environmental Quality regarding “White Stallion Energy Center, PSD Permit Nos. PSD-TX-1160, PAL 26, and HAP 28” (February 10, 2010);
Finally, the Commenter stated that “EPA has issued guidance suggesting [that] PSD sources should use the ozone limiting method for NOX modeling.” The Commenter referred to EPA's March 2011 NOX modeling guidance to support this position.[20] The Commenter then asserts that this “ozone modeling” helps sources demonstrate compliance and that sources should also do ozone modeling that may inhibit a source's permission to pollute. The Commenter argued that EPA's guidance supports the view that EPA must require states to require a specific model in their SIPs to demonstrate that proposed PSD sources do not cause or contribute to a violation of the ozone NAAQS.
At the outset, EPA notes that although the Commenter sought to incorporate by reference the prior petition for rulemaking requesting EPA to designate a particular model for use by states for this purpose, the Agency is not required to respond to that petition in the context of acting upon the infrastructure submission. In reviewing the infrastructure submission, EPA is evaluating the state's submission in light of current statutory and regulatory requirements, not in light of potential future requirements that EPA has been requested to establish in a petition. Moreover, the petition arose in a different context, requests different relief, and raises other issues unrelated to those concerning ozone modeling raised by the Commenter in this action. EPA believes that the appropriate place to respond to the issues raised in the petition is in a petition response. Accordingly, EPA is not responding to the July 28, 2010 petition, in this action. The issues raised in that petition are under separate consideration.
These parts of 40 CFR Part 51 and 52 are the umbrella SIP components that states have either adopted by reference or the states have approved or been delegated authority to incorporate the PSD requirements of the CAA. As Start Printed Page 41131discussed above, these CFR part 51 and 52 PSD requirements refer to 40 CFR Part 51, Appendix W for the appropriate model to utilize for the ambient impact assessment. 40 CFR Part 51, Appendix W is the Guideline on Air Quality models and Section 1.0.a. states:
The Guideline recommends air quality modeling techniques that should be applied to State Implementation Plan (SIP) revisions for existing sources and to new source review (NSR), including prevention of significant deterioration (PSD) [footnotes not included]. Applicable only to criteria air pollutants, it is intended for use by EPA Regional Offices in judging the adequacy of modeling analyses performed by EPA, State and local agencies, and by industry * * * The Guideline is not intended to be a compendium of modeling techniques. Rather, it should serve as a common measure of acceptable technical analysis when supported by sound scientific judgment.
Appendix W Section 5.2.1. includes the Guideline recommendations for models to be utilized in assessing ambient air quality impacts for ozone. Specifically, Section 5.2.1.c states: “Estimating the Impact of Individual Sources. Choice of methods used to assess the impact of an individual source depends on the nature of the source and its emissions. Thus, model users should consult with the Regional Office to determine the most suitable approach on a case-by-case basis (subsection 3.2.2).”
Appendix W Section 5.2.1.c provides that the model users (state and local permitting authorities and permitting applicants) should work with the appropriate EPA Regional Office on a case-by-case basis to determine an adequate method for performing an air quality analysis for assessing ozone impacts. Due to the complexity of modeling ozone and the dependency on the regional characteristics of atmospheric conditions, EPA believes this is an appropriate approach rather than specifying one particular preferred model nationwide, which may not be appropriate in all circumstances. Instead, the choice of method “depends on the nature of the source and its emissions. Thus, model users should consult with the Regional Office * * * .” Appendix W Section 5.2.1.c. Therefore, EPA continues to believe it is appropriate for permitting authorities to consult and work with EPA Regional Offices as described in Appendix W, including section 3.0.b and c, 3.2.2, and 3.3, to determine the appropriate approach to assess ozone impacts for each PSD required evaluation.[23 24 25 26] Although EPA has not selected one particular preferred model in Appendix A of Appendix W (Summaries of Preferred Air Quality Models) for conducting ozone impact analyses for individual sources, state/local permitting authorities must comply with the appropriate PSD FIP or SIP requirements with respect to ozone.
The current SIP meets the requirements of 40 CFR 52.21 and 40 CFR 51.166(l)(1). Specifically, the Mississippi SIP states at Regulation APC-S-2 (V) (B)—Air Quality Models:
“1. All estimates of ambient concentrations of air pollutants shall be based on the applicable air quality models, data bases, and other requirements specified in the “Guideline on Air Quality Models (Revised)” 40 CFR, Part 52,[27] Appendix W, which are incorporated herein and adopted by reference.
2. Where an air quality impact model specified in the “Guideline on Air Quality Models (Revised)” 40 CFR, Part 52,[28] Appendix W, is inappropriate, the model may be modified or another model substituted. Such a modification or substitution of a model may be made on a case-by-case basis or, where appropriate, on a generic basis. Written approval of the DEQ and the Administrator of EPA must be obtained for any modification or substitution. In addition, use of a modified or substituted model shall be subject to public notice and opportunity for public comment.”
Additionally, the Mississippi SIP states at Regulation APC-S-5(1):
The purpose of this regulation is to implement a program for the prevention of significant deterioration of air quality as required by 40 CFR 52.21 and 51.166. This regulation supersedes and replaces the previous adoption by reference of 40 CFR 52.21 and 40 CFR 51.166. 40 CFR 52.21 and 51.166 as used in this regulation refer to the federal regulations as amended and promulgated by July 1, 2004 * * *
These statements in the Federally approved Mississippi SIP provide a reference to 40 CFR Part 51, Appendix W. The commitment in Mississippi's SIP to implement and adopt air quality models utilizing 40 CFR part 51, Appendix W as a basis is appropriate and consistent with Federal regulations.
Mississippi requires that PSD permit applications contain an analysis of ozone impacts from the proposed project. As recommended by Appendix W, the methods used for the ozone impacts analysis for individual PSD permit actions are determined on a case-by-case basis. Mississippi consults with EPA Region 4 on a case-by-case basis for evaluating the adequacy of the ozone impact analysis. When appropriate, EPA Region 4 provides input/comments on the analysis. As stated in Section 5.2.1.c. of Appendix W, the “[c]hoice of methods used to assess the impact of an individual source depends on the nature of the source and its emissions.” Therefore, based on an evaluation of the source, its emissions and background ozone concentrations, an ozone impact analysis other than modeling may be required. While in others cases a Start Printed Page 41132complex photochemical grid type modeling analysis, as discussed below, may be warranted. As noted, the appropriate methods are determined in consultation with EPA Region 4 on a case-by-case basis.
As a second point, the Commenter asserted that states abuse this lack of an explicitly named model by claiming that because no model is explicitly named, no modeling is required or the use of completely irrelevant modeling is allowed.
For ozone, a proposed emission source's impacts are dependent upon local meteorology and pollution levels in the surrounding atmosphere. Ozone is formed from chemical reactions in the atmosphere. The impact a new or modified source can have on ozone levels is dependent, in part, upon the existing atmospheric pollutant loading already in the region with which emissions from the new or modified source can react. In addition, meteorological parameters such as wind speed, temperature, wind direction, solar radiation influx, and atmospheric stability are also important factors. The more sophisticated analyses consider meteorology and interactions with emissions from surrounding sources. EPA has not identified an established modeling system that would fit all situations and take into account all of the additional local information about sources and meteorological conditions. The Commenter submitted a number of exhibits (including Exhibits 10, 11, and 13) in which EPA has previously indicated a preference for using a photochemical grid model when appropriate modeling databases exist and when it is acceptable to use the photochemical grid modeling to assess a specific source.
Commenter's Exhibit 13 includes a list of issues to evaluate, which aid in considering if the existing photochemical grid modeling databases are acceptable, and discusses the need for permitting authorities to consult with the EPA Regional Office in determining if photochemical grid modeling would be appropriate for conducting an ozone impacts analysis. In these documents EPA has indicated that photochemical grid modeling (e.g., CAMx or CMAQ) is generally the most sophisticated type of modeling analysis for evaluating ozone impacts, and it is usually conducted by adding a source into an existing modeling system to determine the change in impact from the source. The analysis is done by comparing the photochemical grid modeling results which include the new or modified source under evaluation with the results from the original modeling analysis that does not contain the source. Photochemical grid modeling is often an excellent modeling exercise for evaluating a single source's impacts on an air quality control region when such models are available and appropriate to utilize because they take into account the important parameters and the models have been used in regional modeling for attainment SIPs.
There are also reactive plume models, however, that may also be appropriate. EPA has approved the use of plume models in some instances, but these models are not always appropriate because of the difficulty in obtaining the background information to make an appropriate assessment of the photochemistry and meteorology impacts.
When an existing photochemical modeling system is deemed appropriate, it is an excellent tool to evaluate the ozone impact that a single source's emissions can have on an air quality region in the context of PSD modeling and should be evaluated for potential use. More often now than 10 or 15 years ago, a photochemical modeling system may be available that covers the geographic area of concern. EPA notes that even where photochemical modeling is readily available, it should be evaluated as part of the development of a modeling protocol, in consultation with the Regional Office to determine its appropriateness for conducting an impact analysis for a particular proposed source or modification.[29] Factors to consider when evaluating the appropriateness of a particular photochemical modeling system include, but are not limited to, meteorology, year of emissions projections, model performance issues in the area of concern or in areas that might impact projections in the area of concern. Therefore, even where photochemical modeling systems exist, there may be circumstances where their use is inappropriate for estimating the ozone impacts of a proposed source or modification. Because of these scientific issues and the need for appropriate case-by-case technical considerations, EPA has not designated a single “Preferred Model” for conducting single source impact analyses for ozone in Appendix A or Appendix W.
In summary, the Commenter states that many States abuse this lack of an explicitly named model by claiming that because no model is explicitly named, no modeling is required or use of Start Printed Page 41133completely irrelevant modeling is allowed. For the reasons described in this response to comment, we do not believe that one modeling system is presently appropriate to designate for all situations, yet that does not relieve proposed sources and modifications from the obligation of making the required demonstration under the applicable PSD rules. The Mississippi SIP contains a reference for use of the procedures specified in EPA's “Guideline on Air Quality Models” (40 CFR part 51 Appendix W) for estimating ambient concentrations of criteria pollutants, including ozone (Regulation APC-S-2 (V)(B)—Air Quality Models). As such, Mississippi requires that PSD permit applications contain an analysis of ozone impacts from the proposed project. As recommended by Appendix W, the methods used for the ozone impacts analysis are determined on a case-by-case basis. Mississippi consults with EPA Region 4 on a case-by-case basis for evaluating the adequacy of the ozone impact analysis. When appropriate, EPA Region 4 provides input/comments on the analysis. Because EPA has not designated one particular model as being appropriate in all situations for evaluating single source ozone impacts, EPA Region 4 concurs with Mississippi's proposed approach.
In conclusion, for the reasons stated it is difficult to identify and implement a specific standardized national model for ozone. EPA has had a standard approach in its PSD SIP and FIP rules of not mandating the use of a particular model for all circumstances, instead treating the choice of a particular method for analyzing ozone impacts as circumstance-dependent. EPA then determines whether the State's implementation plan revision submittal meets the PSD SIP requirements. For purposes of review for this infrastructure SIP, Mississippi has an EPA-approved PSD SIP that meets the EPA PSD requirements under 40 CFR 51.166.
Finally, the Commenter argued that EPA's March 2011 guidance concerning modeling for the 1-hour nitrogen dioxide (NO2) NAAQS demonstrates that similar single source modeling could be conducted for sources for purposes of the ozone NAAQS. Specifically, the commenter argued that the model used for other criteria pollutants (AERMOD), incorporates ozone chemistry for modeling NO2 and therefore is modeling ozone chemistry for a single source. The Commenter stated that this guidance suggested that PSD sources should use the ozone limiting method for NOX modeling.[30] Further, the Commenter noted that this technique “is modeling of ozone chemistry for a single source.” and therefore that this modeling with ozone chemistry allows a source to be permitted. The commenter concludes with the assertion that EPA must require the SIPs to include a model to use to demonstrate that proposed PSD sources do not cause or contribute to a violation of an ozone NAAQS.
EPA's recent March 2011 guidance for the NO2 NAAQS does discuss using two different techniques to estimate the amount of conversion of NOX emissions to NO2 ambient NO2 concentrations as part of the NO2 modeling guidance. NOX emissions are composed of NO and NO2 molecules. These two techniques, which have been available for years, are the Ozone Limiting Method (OLM), which was mentioned by the Commenter, and the Plume Volume Molar-Ratio-Method (PVMRM). Both of these techniques are designed and formulated based on the principle of assuming available atmospheric ozone mixes with NO/NO2 emissions from sources. This “mixing” results in ozone molecules reacting with the NO molecules to form NO2 and O2. This is a simple one-direction chemical reaction that is used to determine how much NO is converted to NO2 for modeling of the NO2 standard. Thus, these techniques do not predict ozone concentrations, rather they take ambient ozone data as model inputs to determine the calculation of NO conversion to NO2. These techniques are not designed to calculate the amount of ozone that might be generated as the NOX emissions traverses downwind of the source and potentially reacts with other pollutants in the atmosphere. Rather, these two techniques rely on a one-way calculation based on an ozone molecule (O3) reacting with an NO molecule to generate an NO2 molecule and an O2 molecule.[31 32]
For the reasons discussed above, EPA does not believe that the comments provide a basis for not approving the infrastructure submission. In short, EPA has not modified the Guidelines in Appendix W for ozone impacts analysis for a single source (Appendix W Part 5.2.1.c.) to require use of a specific model as the Commenter requests. EPA finds that the State has the appropriate regulations to operate the PSD program consistent with Federal requirements. Furthermore, we disagree that states are required to designate a specific model in the SIP, because App. W states that state and local agencies should consult with EPA on a case-by-case basis to determine what analysis to require.
As described above, MDEQ has addressed the elements of the CAA 110(a)(1) and (2) SIP requirements pursuant to EPA's October 2, 2007, guidance to ensure that the 1997 8-hour ozone NAAQS are implemented, enforced, and maintained in Mississippi. EPA is taking final action to Start Printed Page 41134approve Mississippi's December 7, 2007, infrastructure submission for the 1997 8-hour ozone NAAQS because this submission is consistent with section 110 of the CAA.
2. Section 52.1270(e) is added to read as follows:
(e) EPA approved Mississippi non-regulatory provisions.
110(a)(1) and (2) Infrastructure Requirements for the 1997 8-Hour Ozone National Ambient Air Quality Standards Mississippi 12/7/2007 7/13/2011 [Insert citation of publication] For the 1997 8-hour ozone NAAQS.
Start Printed Page 41135 End Supplemental Information
1. Two elements identified in section 110(a)(2) are not governed by the three-year submission deadline of section 110(a)(1) because SIPs incorporating necessary local nonattainment area controls are not due within three years after promulgation of a new or revised NAAQS, but rather are due at the time the nonattainment area plan requirements are due pursuant to section 172. These requirements are: (1) Submissions required by section 110(a)(2)(C) to the extent that subsection refers to a permit program as required in part D Title I of the CAA, and (2) submissions required by section 110(a)(2)(I) which pertain to the nonattainment planning requirements of part D, Title I of the CAA. Today's final rulemaking does not address infrastructure elements related to section 110(a)(2)(I) but does provide detail on how Mississippi's SIP addresses 110(a)(2)(C).
3. Today's final rule does not address element 110(a)(2)(D)(i) (Interstate Transport) for the 1997 8-hour ozone NAAQS. Interstate transport requirements were formerly addressed by Mississippi consistent with the Clean Air Interstate Rule (CAIR). On December 23, 2008, CAIR was remanded by the DC Circuit Court of Appeals, without vacatur, back to EPA. See North Carolina v. EPA, 531 F.3d 896 (DC Cir. 2008). Prior to this remand, EPA took final action to approve Mississippi's SIP revision, which was submitted to comply with CAIR. See 72 FR 56268 (October 3, 2007). In so doing, Mississippi's CAIR SIP revision addressed the interstate transport provisions in Section 110(a)(2)(D)(i) for the 1997 8-hour ozone NAAQS. In response to the remand of CAIR, EPA has since proposed a new rule to address the interstate transport of NOX and SOX in the eastern United States. See 75 FR 45210 (Aug. 2, 2010) (“the Transport Rule”). However, because this rule has yet to be finalized, EPA's action on element 110(a)(2)(D)(i) will be addressed in a separate action.
5. See, Comments of Midwest Environmental Defense Center, dated May 31, 2011. Docket #EPA-R05-OAR-2007-1179 (adverse comments on proposals for three states in Region 5). EPA notes that these public comments on another proposal are not relevant to this rulemaking and do not have to be directly addressed in this rulemaking. EPA will respond to these comments in the appropriate rulemaking action to which they apply.
7. For example, section 110(a)(2)(D)(i) requires EPA to ensure that each state's SIP contains adequate provisions to prevent significant contribution to nonattainment of the NAAQS in other states. This provision contains numerous terms that require substantial rulemaking by EPA in order to determine such basic points as what constitutes significant contribution. See, e.g., “Rule To Reduce Interstate Transport of Fine Particulate Matter and Ozone (Clean Air Interstate Rule); Revisions to Acid Rain Program; Revisions to the NOX SIP Call; Final Rule,” 70 FR 25162 (May 12, 2005) (defining, among other things, the phrase “contribute significantly to nonattainment”).
11. See, “Guidance on SIP Elements Required Under Section 110(a)(1) and (2) for the 1997 8-hour Ozone and PM2.5 National Ambient Air Quality Standards,” from William T. Harnett, Director Air Quality Policy Division, to Air Division Directors, Regions I-X, dated October 2, 2007 (the “2007 Guidance”). EPA issued comparable guidance for the 2006 PM2.5 NAAQS entitled “Guidance on SIP Elements Required Under Sections 110(a)(1) and (2) for the 2006 24-Hour Fine Particle (PM2.5) National Ambient Air Quality Standards (NAAQS),” from William T, Harnett, Director Air Quality Policy Division, to Regional Air Division Directors, Regions I-X, dated September 25, 2009 (the “2009 Guidance”).
18. There were no areas in Mississippi designated nonattainment for the 1997 8-hour ozone NAAQS. The entire state was designated Unclassifiable/Attainment. Currently, Mississippi has no areas violating the 1997 8-hour ozone NAAQS and the State does not contain any nonattainment areas for this NAAQS.
20. The Commenter attached an EPA memorandum dated March 1, 2011: “Additional Clarification Regarding Application of Appendix W Modeling Guidance for the 1-hour NO2 National Ambient Air Quality Standard,” from Tyler Fox, Leader, Air Quality Modeling Group, Office of Air Quality Planning and Standards.
25. 40 CFR part 51 Appendix W, Section 3.2.2.a. states: “Determination of acceptability of a model is a Regional Office responsibility. Where the Regional Administrator finds that an alternative model is more appropriate than a preferred model, that model may be used subject to the recommendations of this subsection. This finding will normally result from a determination that (1) a preferred air quality model is not appropriate for the particular application; or (2) a more appropriate model or analytical procedure is available and applicable.”
26. 40 CFR part 51 Appendix W, Section 3.3.a. states: “The Regional Administrator has the authority to select models that are appropriate for use in a given situation. However, there is a need for assistance and guidance in the selection process so that fairness and consistency in modeling decisions is fostered among the various Regional Offices and the States. To satisfy that need, EPA established the Model Clearinghouse and also holds periodic workshops with headquarters, Regional Office, State, and local agency modeling representatives.” Section 3.3.b. states “The Regional Office should always be consulted for information and guidance concerning modeling methods and interpretations of modeling guidance, and to ensure that the air quality model user has available the latest most up-to-date policy and procedures. As appropriate, the Regional Office may request assistance from the Model Clearinghouse after an initial evaluation and decision has been reached concerning the application of a model, analytical technique or data base in a particular regulatory action.” (footnote omitted).
27. This reference to part 52 is a typographical error and should reference part 51.
28. This reference to part 52 is a typographical error and should reference part 51.
29. 40 CFR part 51 Appendix W, Sections 3.0, 3.2., 3.3, 5.2.1.c and commenter Exhibit 13.
30. The Commenter attached EPA memorandum dated March 1, 2011: “Additional Clarification Regarding Application of Appendix W Modeling Guidance for the 1-hour NO2 National Ambient Air Quality Standard,” from Tyler Fox, Leader, Air Quality Modeling Group, Office of Air Quality Planning and Standards.
31. “AERMOD: Model Formulation Document”, http://www.epa.gov/​scram001/​7thconf/​aermod/​aermod_​mfd_​addm_​rev.pdf.
32. Hanrahan, P.L., 1999a. “The plume volume molar ratio method for determining NO2/NOX ratios in modeling. Part I: Methodology,” J. Air & Waste Manage. Assoc., 49, 1324-1331.
[FR Doc. 2011-17467 Filed 7-12-11; 8:45 am]