2012-14267. Approval and Promulgation of Implementation Plans; Mississippi; 110(a)(1) and (2) Infrastructure Requirements for the 1997 and 2006 Fine Particulate Matter National Ambient Air Quality Standards

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

EPA is proposing to approve the State Implementation Plan (SIP), submitted by the State of Mississippi, through the Mississippi Department of Environmental Quality (DEQ), as meeting certain requirements of sections 110(a)(1) and (2) of the Clean Air Act (CAA or the Act) for the 1997 annual and 2006 24-hour fine particulate matter (PM_2.5) 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 that the 1997 annual and 2006 24-hour PM_2.5 NAAQS are implemented, enforced, and maintained in Mississippi (hereafter referred to as “infrastructure submission”). EPA is proposing to determine that Mississippi's infrastructure submissions, provided to EPA on December 7, 2007, and on October 6, 2009, addressed all the required infrastructure elements for the 1997 annual and 2006 24-hour PM_2.5 NAAQS with the exception of sections 110(a)(2)(E)(ii) and 110(a)(2)(G), both of which will be addressed in a separate action.

DATES:

Written comments must be received on or before July 12, 2012.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-R04-OAR-2012-0402, by one of the following methods:

1. www.regulations.gov: Follow the on-line instructions for submitting comments.

2. Email: [e-mail].

3. Fax: [phone].

4. Mail: “EPA-R04-OAR-2012-0402,” 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.

5. Hand Delivery or Courier: Lynorae Benjamin, 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. Such deliveries are only accepted during the Regional Office's normal hours of operation. The Regional Office's official hours of business are Monday through Friday, 8:30 to 4:30, excluding federal holidays.

Instructions: Direct your comments to Docket ID No. EPA-R04-OAR-2012-0402. EPA's policy is that all comments received will be included in the public docket without change and may be made available online at www.regulations.gov,, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit through www.regulations.gov or email, information that you consider to be CBI or otherwise protected. The www.regulations.gov Web site is an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an email comment directly to EPA without going through www.regulations.gov,, your email address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses. For additional information about EPA's public docket visit the EPA Docket Center homepage at http://www.epa.gov/​epahome/​dockets.htm.

Docket: All documents in the electronic docket are listed in the www.regulations.gov index. Although listed in the index, some information is not publicly available, i.e., CBI 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 in 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.

FOR FURTHER INFORMATION CONTACT:

Sean Lakeman, 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. The telephone number is [phone]. Mr. Lakeman can be reached via electronic mail at [e-mail].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Background

II. What elements are required under sections 110(a)(1) and (2)?

III. Scope of Infrastructure SIPs

IV. What is EPA's analysis of how Mississippi addressed the elements of sections 110(a)(1) and (2) “infrastructure” provisions?

V. Proposed Action

VI. Statutory and Executive Order Reviews

I. Background

On July 18, 1997 (62 FR 36852), EPA established an annual PM_2.5 NAAQS at 15.0 micrograms per cubic meter (μg/m³) based on a 3-year average of annual mean PM_2.5 concentrations. At that time, EPA also established a 24-hour NAAQS of 65 μg/m³. See 40 CFR 50.7. On October 17, 2006 (71 FR 61144), EPA retained the 1997 annual PM_2.5 NAAQS at 15.0 μg/m³ based on a 3-year average of annual mean PM_2.5 concentrations, and promulgated a new 24-hour NAAQS of 35 μg/m³ based on a 3-year average of the 98th percentile of 24-hour concentrations. By statute, SIPs meeting the requirements of sections 110(a)(1) and (2) are to be submitted by states within three years after promulgation of a new or revised NAAQS. Sections 110(a)(1) and (2) require states to address basic SIP requirements, including emissions inventories, monitoring, and modeling to assure attainment and maintenance of the NAAQS. States were required to submit such SIPs to EPA no later than July 2000 for the 1997 annual PM_2.5 NAAQS, no later than October 2009 for the 2006 24-hour PM_2.5 NAAQS.

On March 4, 2004, Earthjustice submitted a notice of intent to sue related to EPA's failure to issue findings of failure to submit related to the “infrastructure” requirements for the 1997 annual PM_2.5 NAAQS. On March 10, 2005, EPA entered into a consent decree with Earthjustice which required EPA, among other things, to complete a Federal Register notice announcing EPA's determinations pursuant to section 110(k)(1)(B) as to whether each state had made complete submissions to meet the requirements of section 110(a)(2) for the 1997 PM_2.5 NAAQS by October 5, 2008. In accordance with the consent decree, EPA made completeness findings for each state based upon what the Agency received from each state for the 1997 PM_2.5 NAAQS as of October 3, 2008.

On October 22, 2008, EPA published a final rulemaking entitled, “Completeness Findings for Section 110(a) State Implementation Plans Pertaining to the Fine Particulate Matter (PM_2.5) NAAQS” making a finding that each state had submitted or failed to submit a complete SIP that provided the basic program elements of section 110(a)(2) necessary to implement the 1997 PM_2.5 NAAQS (See 73 FR 62902). For those states that did receive findings, the findings of failure to submit for all or a portion of a state's implementation plan established a 24-month deadline for EPA to promulgate a Federal Implementation Plan (FIP) to address the outstanding SIP elements unless, prior to that time, the affected states submitted, and EPA approved, the required SIPs.

The findings that all or portions of a state's submission are complete established a 12-month deadline for EPA to take action upon the complete SIP elements in accordance with section 110(k). Mississippi's infrastructure submissions were received by EPA on December 7, 2007, for the 1997 annual PM_2.5 NAAQS and on October 6, 2009, for the 2006 24-hour PM_2.5 NAAQS. The submissions were determined to be complete on June 7, 2008, and April 6, 2010, respectively. Mississippi was among other states that did not receive findings of failure to submit because it had provided a complete submission to EPA to address the infrastructure elements for the 1997 PM_2.5 NAAQS by October 3, 2008.

On July 6, 2011, WildEarth Guardians and Sierra Club filed an amended complaint related to EPA's failure to take action on the SIP submittal related to the “infrastructure” requirements for the 2006 24-hour PM_2.5 NAAQS. On October 20, 2011, EPA entered into a consent decree with WildEarth Guardians and Sierra Club which required EPA, among other things, to complete a Federal Register notice of the Agency's final action either approving, disapproving, or approving in part and disapproving in part the Mississippi 2006 24-hour PM_2.5 NAAQS Infrastructure SIP submittal addressing the applicable requirements of sections 110(a)(2)(A)-(H), (J)-(M), except for section 110(a)(2)(C) the nonattainment area requirements and section 110(a)(2)(D)(i) interstate transport requirements, by September 30, 2012.

Today's action is proposing to approve Mississippi's infrastructure submission for the 1997 annual and 2006 24-hour PM_2.5 NAAQS for sections 110(a)(2)(A)-(H), (J)-(M), except for sections 110(a)(2)(C) nonattainment area requirements, 110(a)(2)(D)(i) interstate transport requirements, 110(a)(2)(E)(ii) state board requirements, and 110(a)(2)(G) emergency power requirements. Section 110(a)(2)(E)(ii) and (G) will be addressed in a separate action.^[1] This action is not approving any specific rule, but rather proposing that Mississippi's already approved SIP meets certain CAA requirements.

II. What elements are required under sections 110(a)(1) and (2)?

Section 110(a) of the CAA requires states to submit SIPs to provide for the implementation, maintenance, and enforcement of a new or revised NAAQS within three years following the promulgation of such NAAQS, or within such shorter period as EPA may prescribe. Section 110(a) imposes the obligation upon states to make a SIP submission to EPA for a new or revised NAAQS, but the contents of that submission may vary depending upon the facts and circumstances. In particular, the data and analytical tools available at the time the state develops and submits the SIP for a new or revised NAAQS affects the content of the submission. The contents of such SIP submissions may also vary depending upon what provisions the state's existing SIP already contains. In the case of the 1997 annual and 2006 24-hour PM_2.5 NAAQS, some states may need to adopt language specific to the PM_2.5 NAAQS to ensure that they have adequate SIP provisions to implement the PM_2.5 NAAQS.

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 proposed rulemaking are listed below ^[2] 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 PM_2.5 National Ambient Air Quality Standards” and September 25, 2009, memorandum entitled “Guidance on SIP Elements Required Under Section 110(a)(1) and (2) for the 2006 24-Hour Fine Particle (PM_2.5) National Ambient Air Quality Standards.”

• 110(a)(2)(A): Emission limits and other control measures.
• 110(a)(2)(B): Ambient air quality monitoring/data system.
• 110(a)(2)(C): Program for enforcement of control measures.^[3]

• 110(a)(2)(D): Interstate transport.^[4]

• 110(a)(2)(E): Adequate resources.
• 110(a)(2)(F): Stationary source monitoring system.
• 110(a)(2)(G): Emergency power.
• 110(a)(2)(H): Future SIP revisions.
• 110(a)(2)(I): Areas designated nonattainment and meet the applicable requirements of part D.^[5]

• 110(a)(2)(J): Consultation with government officials; public notification; and PSD and visibility protection.
• 110(a)(2)(K): Air quality modeling/data.
• 110(a)(2)(L): Permitting fees.
• 110(a)(2)(M): Consultation/participation by affected local entities.

III. Scope of Infrastructure SIPs

EPA is currently acting upon SIPs that address the infrastructure requirements of CAA section 110(a)(1) and (2) for ozone and PM_2.5 NAAQS for various states across the country. Commenters on EPA's recent proposals for some states raised concerns about EPA statements that it was not addressing certain substantive issues in the context of acting on those infrastructure SIP submissions.^[6] Those Commenters specifically raised concerns involving provisions in existing SIPs and with EPA's statements in other proposals that it would address two issues separately and not as part of actions on the infrastructure SIP submissions: (i) Existing provisions related to excess emissions during periods of start-up, shutdown, or malfunction at sources (SSM), that may be contrary to the CAA and EPA's policies addressing such excess emissions; and (ii) existing provisions related to “director's variance” or “director's discretion” that purport to permit revisions to SIP approved emissions limits with limited public process or without requiring further approval by EPA, that may be contrary to the CAA (director's discretion). EPA notes that there are two other substantive issues for which EPA likewise stated in other proposals that it would address separately: (i) Existing provisions for minor source new source review (NSR) programs that may be inconsistent with the requirements of the CAA and EPA's regulations that pertain to such programs (minor source NSR); and (ii) existing provisions for Prevention of Significant Deterioration (PSD) programs that may be inconsistent with current requirements of EPA's “Final NSR Improvement Rule,” 67 FR 80186 (December 31, 2002), as amended by 72 FR 32526 (June 13, 2007) (NSR Reform). In light of the comments, EPA believes that its statements in various proposed actions on infrastructure SIPs with respect to these four individual issues should be explained in greater depth. It is important to emphasize that EPA is taking the same position with respect to these four substantive issues in this action on the infrastructure SIPs for the 1997 and 2006 PM_2.5 NAAQS from Mississippi.

EPA intended the statements in the other 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 re-approval 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 existing 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 PM_2.5 NAAQS should not be construed as explicit or implicit re-approval of any existing provisions that relate to these four substantive issues. EPA is reiterating that position in this action on the infrastructure SIP for Mississippi.

Unfortunately, the Commenters and others evidently interpreted these statements to mean that EPA considered action upon the SSM provisions and the other three substantive issues to be integral parts of acting on an infrastructure SIP submission, and therefore that EPA was merely postponing taking final action on the issues in the context of the infrastructure SIPs. This was not EPA's intention. To the contrary, EPA only meant to convey its awareness of the potential for certain types of deficiencies in existing SIPs and to prevent any misunderstanding that it was reapproving any such existing provisions. EPA's intention was to convey its position that the statute does not require that infrastructure SIPs address these specific substantive issues in existing SIPs and that these issues may be dealt with separately, outside the context of acting on the infrastructure SIP submission of a state. To be clear, EPA did not mean to imply that it was not taking a full final agency action on the infrastructure SIP submission with respect to any substantive issue that EPA considers to be a required part of acting on such submissions under section 110(k) or under section 110(c). Given the confusion evidently resulting from EPA's statements in those other proposals, however, we want to explain more fully the Agency's reasons for concluding that these four potential substantive issues in existing SIPs may be addressed separately from actions on infrastructure SIP submissions.

The requirement for the SIP submissions at issue arises out of CAA section 110(a)(1). That provision requires that states must make a SIP submission “within 3 years (or such shorter period as the Administrator may prescribe) after the promulgation of a national primary ambient air quality standard (or any revision thereof)” and that these SIPs are to provide for the “implementation, maintenance, and enforcement” of such NAAQS. Section 110(a)(2) includes a list of specific elements that “[e]ach such plan” submission must meet. EPA has historically referred to these particular submissions that states must make after the promulgation of a new or revised NAAQS as “infrastructure SIPs.” This specific term does not appear in the statute, but EPA uses the term to distinguish this particular type of SIP submission designed to address basic structural requirements of a SIP from other types of SIP submissions designed to address other different requirements, such as “nonattainment SIP” submissions required to address the nonattainment planning requirements of part D, “regional haze SIP” submissions required to address the visibility protection requirements of CAA section 169A, NSR permitting program submissions required to address the requirements of part D, and a host of other specific types of SIP submissions that address other specific matters.

Although section 110(a)(1) addresses the timing and general requirements for these infrastructure SIPs, and section 110(a)(2) provides more details concerning the required contents of these infrastructure SIPs, EPA believes that many of the specific statutory provisions are facially ambiguous. In particular, the list of required elements provided in section 110(a)(2) contains a wide variety of disparate provisions, some of which pertain to required legal authority, some of which pertain to required substantive provisions, and some of which pertain to requirements for both authority and substantive provisions.^[7] Some of the elements of section 110(a)(2) are relatively straightforward, but others clearly require interpretation by EPA through rulemaking, or recommendations through guidance, in order to give specific meaning for a particular NAAQS.^[8]

Notwithstanding that section 110(a)(2) provides that “each” SIP submission must meet the list of requirements therein, EPA has long noted that this literal reading of the statute is internally inconsistent, insofar as section 110(a)(2)(I) pertains to nonattainment SIP requirements that could not be met on the schedule provided for these SIP submissions in section 110(a)(1).^[9] This illustrates that EPA must determine which provisions of section 110(a)(2) may be applicable for a given infrastructure SIP submission. Similarly, EPA has previously decided that it could take action on different parts of the larger, general “infrastructure SIP” for a given NAAQS without concurrent action on all subsections, such as section 110(a)(2)(D)(i), because the Agency bifurcated the action on these latter “interstate transport” provisions within section 110(a)(2) and worked with states to address each of the four prongs of section 110(a)(2)(D)(i) with substantive administrative actions proceeding on different tracks with different schedules.^[10] This illustrates that EPA may conclude that subdividing the applicable requirements of section 110(a)(2) into separate SIP actions may sometimes be appropriate for a given NAAQS where a specific substantive action is necessitated, beyond a mere submission addressing basic structural aspects of the state's implementation plans. Finally, EPA notes that not every element of section 110(a)(2) would be relevant, or as relevant, or relevant in the same way, for each new or revised NAAQS and the attendant infrastructure SIP submission for that NAAQS. For example, the monitoring requirements that might be necessary for purposes of section 110(a)(2)(B) for one NAAQS could be very different than what might be necessary for a different pollutant. Thus, the content of an infrastructure SIP submission to meet this element from a state might be very different for an entirely new NAAQS, versus a minor revision to an existing NAAQS.^[11]

Similarly, EPA notes that other types of SIP submissions required under the statute also must meet the requirements of section 110(a)(2), and this also demonstrates the need to identify the applicable elements for other SIP submissions. For example, nonattainment SIPs required by part D likewise have to meet the relevant subsections of section 110(a)(2) such as section 110(a)(2)(A) or (E). By contrast, it is clear that nonattainment SIPs would not need to meet the portion of section 110(a)(2)(C) that pertains to part C, i.e., the PSD requirements applicable in attainment areas. Nonattainment SIPs required by part D also would not need to address the requirements of section 110(a)(2)(G) with respect to emergency episodes, as such requirements would not be limited to nonattainment areas. As this example illustrates, each type of SIP submission may implicate some subsections of section 110(a)(2) and not others.

Given the potential for 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 ozone and PM_2.5 NAAQS.

On October 2, 2007, EPA issued guidance making recommendations for the infrastructure SIP submissions for both the 1997 8-hour ozone NAAQS and the 1997 PM_2.5 NAAQS.^[12] Within this guidance document, EPA described the duty of states to make these submissions to meet what the Agency characterized as the “infrastructure” elements for SIPs, which it further described as the “basic SIP requirements, including emissions inventories, monitoring, and modeling to assure attainment and maintenance of the standards.” ^[13] As further identification of these basic structural SIP requirements, “attachment A” to the guidance document included a short description of the various elements of section 110(a)(2) and additional information about the types of issues that EPA considered germane in the context of such infrastructure SIPs. EPA emphasized that the description of the basic requirements listed on attachment A was not intended “to constitute an interpretation of” the requirements, and was merely a “brief description of the required elements.” ^[14] EPA also stated its belief that with one exception, these requirements were “relatively self explanatory, and past experience with SIPs for other NAAQS should enable States to meet these requirements with assistance from EPA Regions.” ^[15] However, for the one exception to that general assumption (i.e., how states should proceed with respect to the requirements of section 110(a)(2)(G) for the 1997 PM_2.5 NAAQS), EPA gave much more specific recommendations. But for other infrastructure SIP submittals, and for certain elements of the submittals for the 1997 PM_2.5 NAAQS, EPA assumed that each state would work with its corresponding EPA regional office to refine the scope of a state's submittal based on an assessment of how the requirements of section 110(a)(2) should reasonably apply to the basic structure of the state's implementation plans for the NAAQS in question.

On September 25, 2009, EPA issued guidance to make recommendations to states with respect to the infrastructure SIPs for the 2006 PM_2.5 NAAQS.^[16] In the 2009 Guidance, EPA addressed a number of additional issues that were not germane to the infrastructure SIPs for the 1997 8-hour ozone and 1997 PM_2.5 NAAQS, but were germane to these SIP submissions for the 2006 PM_2.5 NAAQS (e.g., the requirements of section 110(a)(2)(D)(i) that EPA had bifurcated from the other infrastructure elements for those specific 1997 ozone and PM_2.5 NAAQS). Significantly, neither the 2007 Guidance nor the 2009 Guidance explicitly referred to the SSM, director's discretion, minor source NSR, or NSR Reform issues as among specific substantive issues EPA expected states to address in the context of the infrastructure SIPs, nor did EPA give any more specific recommendations with respect to how states might address such issues even if they elected to do so. The SSM and director's discretion issues implicate section 110(a)(2)(A), and the minor source NSR and NSR Reform issues implicate section 110(a)(2)(C). In the 2007 Guidance and the 2009 Guidance, however, EPA did not indicate to states that it intended to interpret these provisions as requiring a substantive submission to address these specific issues in existing SIP provisions in the context of the infrastructure SIPs for these NAAQS. Instead, EPA's 2007 Guidance merely indicated its belief that the states should make submissions in which they established that they have the basic SIP structure necessary to implement, maintain, and enforce the NAAQS. EPA believes that states can establish that they have the basic SIP structure, notwithstanding that there may be potential deficiencies within the existing SIP. Thus, EPA's proposals for other states mentioned these issues not because the Agency considers them issues that must be addressed in the context of an infrastructure SIP as required by section 110(a)(1) and (2), but rather because EPA wanted to be clear that it considers these potential existing SIP problems as separate from the pending infrastructure SIP actions. The same holds true for this action on the infrastructure SIPs for Mississippi.

EPA believes that this approach to the infrastructure SIP requirement is reasonable because it would not be feasible to read section 110(a)(1) and (2) to require a top to bottom, stem to stern, review of each and every provision of an existing SIP merely 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 PM_2.5 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 section 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 Agency 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.^[17] Section 110(k)(6) authorizes EPA to correct errors in past actions, such as past approvals of SIP submissions.^[18] 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.^[19]

IV. What is EPA's analysis of how Mississippi addressed the elements of sections 110(a)(1) and (2) “infrastructure” provisions?

Mississippi's infrastructure submissions address the provisions of sections 110(a)(1) and (2) as described below.

1. 110(a)(2)(A): Emission limits and other control measures: Mississippi's infrastructure submissions provide an overview of the provisions of the Mississippi Air Pollution Control (APC) Regulations relevant to air quality control. The regulations described below have been federally approved into the Mississippi SIP and include enforceable emission limitations and other control measures. Mississippi SIP Regulations APC-S-1—Air Emission Regulations for the Prevention, Abatement, and Control of Air Contaminants, and APC-S-3—Regulations for the Prevention of Air Pollution Emergency Episodes, generally authorizes DEQ to adopt rules for the control of air pollution, including those necessary to obtain EPA approval under section 110 of the CAA. The most recent federally approved revision in this regulation was on October 3, 2007 (72 FR 56268). EPA has made the preliminary determination that the provisions contained in these regulations and Mississippi's practices are adequate to protect the PM_2.5 annual and 24-hour NAAQS in the State.

In this action, EPA is not proposing to approve or disapprove any existing state provisions with regard to excess emissions during SSM of operations at a facility. EPA believes that a number of states have SSM provisions which are contrary to the CAA and existing EPA guidance, “State Implementation Plans: Policy Regarding Excess Emissions During Malfunctions, Startup, and Shutdown” (September 20, 1999), and the Agency plans to address such state regulations in the future. In the meantime, EPA encourages any state having deficient SSM provisions to take steps to correct it as soon as possible.

Additionally, in this action, EPA is not proposing to approve or disapprove any existing state rules with regard to director's discretion or variance provisions. EPA believes that a number of states have such provisions which are contrary to the CAA and existing EPA guidance (52 FR 45109 (November 24, 1987)), and the Agency plans to take action in the future to address such state regulations. In the meantime, EPA encourages any state having a director's discretion or variance provision which is contrary to the CAA and EPA guidance to take steps to correct the deficiency as soon as possible.

2. 110(a)(2)(B) Ambient air quality monitoring/data system: Mississippi's infrastructure submissions cite SIP Regulation APC-S-1—Air Emission Regulations for the Prevention, Abatement, and Control of Air Contaminants, with regard to the monitoring program within the State. Annually, EPA approves the ambient air monitoring network plan for the state agencies. On October 6, 2011, EPA approved Mississippi's 2011 monitoring network plan. Mississippi's approved monitoring network plan can be accessed at www.regulations.gov using Docket ID No. EPA-R04-OAR-2012-0402. EPA has made the preliminary determination that Mississippi's SIP and practices are adequate for the ambient air quality monitoring and data systems related to the 1997 annual and 2006 24-hour PM_2.5 NAAQS.

3. 110(a)(2)(C) Program for enforcement of control measures including review of proposed new sources: Mississippi's authority to regulate new and modified sources so as to provide for the protection of air quality in nonattainment, attainment or unclassifiable areas is established in the Mississippi SIP Regulations APC-S-1—Air Emission Regulations for the Prevention, Abatement, and Control of Air Contaminants, APC-S-2—Permit Regulations for the Construction and/or Operation of Air Emissions Equipment, and APC-S-5—Regulations for the Prevention of Significant Deterioration of Air Quality. Mississippi's regulations provide the permitting requirements for new major sources or major modifications of existing sources in areas classified as attainment or unclassifiable under section 107(d)(1)(A)(ii) or (iii) of the CAA. This permitting program is designed to ensure that sources in areas attaining the NAAQS at the time of designations prevent any significant deterioration in air quality. Additionally, on May 18, 2011, Mississippi submitted a SIP revision to its NSR/PSD and Nonattainment New Source Review (NNSR) programs. Mississippi's May 18, 2011, SIP submittal would incorporate by reference the federal NSR provisions for fine particulate matter (also known as PM_2.5) as amended in EPA's 2008 NSR PM_2.5 Implementation Rule (hereafter referred to as the “NSR PM_2.5 Rule”) into the Mississippi SIP at APC-S-5—Regulations for the Prevention of Significant Deterioration of Air Quality. In the May 18, 2011, SIP revision, Mississippi includes revisions to rules that address the infrastructure requirements (C) and (J). As such, today's proposed approval of Mississippi's SIP respecting infrastructure element 110(a)(2)(C) is contingent upon EPA first taking final action to approve the May 18, 2011, NSR PM_2.5 Rule revision into the State's SIP. EPA will propose approval of Mississippi's May 18, 2011, NSR PM_2.5 Rule revision in a rulemaking separate from today's action.

In this action, EPA is proposing to approve Mississippi's infrastructure SIP for the 1997 annual and 2006 24-hour PM_2.5 NAAQS with respect to the general requirement in section 110(a)(2)(C) to include a program in the SIP that regulates the modification and construction of any stationary source as necessary to assure that the NAAQS are achieved. EPA is not proposing to approve or disapprove the State's existing minor NSR program itself to the extent that it is inconsistent with EPA's regulations governing this program. EPA believes that a number of states may have minor NSR provisions that are contrary to the existing EPA regulations for this program. EPA intends to work with states to reconcile state minor NSR programs with EPA's regulatory provisions for the program. The statutory requirements of section 110(a)(2)(C) provide for considerable flexibility in designing minor NSR programs, and EPA believes it may be time to revisit the regulatory requirements for this program to give the states an appropriate level of flexibility to design a program that meets their particular air quality concerns, while assuring reasonable consistency across the country in protecting the NAAQS with respect to new and modified minor sources.

EPA has made the preliminary determination that Mississippi's SIP and practices are adequate for program enforcement of control measures including review of proposed new sources related to the 1997 annual and 2006 24-hour PM_2.5 NAAQS. As discussed above, final approval of this rule is contingent upon the Agency first taking final action to approve Mississippi's May 18, 2011, PM_2.5 NSR Update.

4. 110(a)(2)(D)(ii) Interstate and International transport provisions: In Regulation APC-S-2—Permit Regulations For The Construction and/or Operation of Air Emissions Equipment, Mississippi provides how it will notify neighboring states of potential impacts from new or modified sources. The most recent federally approved revision in this regulation was on July 10, 2006 (71 FR 38773). Mississippi does not have any pending obligation under section 115 and 126 of the CAA. EPA has made the preliminary determination that Mississippi's SIP and practices are adequate for insuring compliance with the applicable requirements relating to interstate and international pollution abatement for the 1997 annual and 2006 24-hour PM_2.5 NAAQS.

5. 110(a)(2)(E) Adequate resources: Section 110(a)(2)(E) requires that each implementation plan provide (i) necessary assurances that the State will have adequate personnel, funding, and authority under state law to carry out its implementation plan, (ii) that the State comply with the requirements respecting State Boards pursuant to section 128 of the Act, and (iii) necessary assurances that, where the State has relied on a local or regional government, agency, or instrumentality for the implementation of any plan provision, the State has responsibility for ensuring adequate implementation of such plan provisions. As with the remainder of the infrastructure elements addressed by this notice, EPA is proposing to approve Mississippi's SIP as meeting the requirements of sub-elements 110(a)(2)(E)(i) and (iii). With respect to 110(a)(2)(E)(ii) (regarding state boards), EPA is not taking action on this sub-element today, and will instead address this requirement in a separate action. EPA's rationale for today's proposals respecting sub-element 110(a)(2)(E)(i) and (iii) is described in turn below.

In support of EPA's proposal to approve sub-elements 110(a)(2)(E)(i) and (iii), DEQ is responsible for promulgating rules and regulations for the NAAQS, emissions standards general policies, a system of permits, fee schedules for the review of plans, and other planning needs. As evidence of the adequacy of DEQ's resources with respect to sub-elements (i) and (iii), EPA submitted a letter to Mississippi on March 8, 2012, outlining 105 grant commitments and the current status of these commitments for fiscal year 2011. The letter EPA submitted to Mississippi can be accessed at www.regulations.gov using Docket ID No. EPA-R04-OAR-2012-0402. Annually, states update these grant commitments based on current SIP requirements, air quality planning, and applicable requirements related to the NAAQS. Mississippi satisfactorily met all commitments agreed to in the Air Planning Agreement for fiscal year 2011, therefore Mississippi's grants were finalized and closed out. EPA has made the preliminary determination that Mississippi has adequate resources for implementation of the 1997 annual and 2006 24-hour PM_2.5 NAAQS. In addition, the requirements of 110(a)(2)(E)(i) and (iii) are met when EPA performs a completeness determination for each SIP submittal. This determination ensures that each submittal provides evidence that adequate personnel, funding, and legal authority under state law has been used to carry out the state's implementation plan and related issues. Mississippi's authority is included in all prehearings and final SIP submittal packages for approval by EPA. EPA has made the preliminary determination that Mississippi has adequate resources for implementation of the 1997 annual and 2006 24-hour PM_2.5 NAAQS.

6. 110(a)(2)(F) Stationary source monitoring system : Regulation APC-S-2—Permit Regulations for the Construction and/or Operation of Air Emissions Equipment, of the Mississippi SIP establishes requirements for emissions compliance testing utilizing emissions sampling and analysis. It further describes how the State ensures the quality of its data through observing emissions and monitoring operations. Mississippi DEQ uses these data to track progress towards maintaining the NAAQS, develop control and maintenance strategies, identify sources and general emission levels, and determine compliance with emission regulations and additional EPA requirements.

Additionally, Mississippi is required to submit emissions data to EPA for purposes of the National Emissions Inventory (NEI). The NEI is EPA's central repository for air emissions data. EPA published the Air Emissions Reporting Rule (AERR) on December 5, 2008, which modified the requirements for collecting and reporting air emissions data (73 FR 76539). The AERR shortened the time states had to report emissions data from 17 to 12 months, giving states one calendar year to submit emissions data. All states are required to submit a comprehensive emissions inventory every three years and report emissions for certain larger sources annually through EPA's online Emissions Inventory System (EIS). States report emissions data for the six criteria pollutants and the precursors that form them—nitrogen oxides, sulfur dioxide, ammonia, lead, carbon monoxide, particulate matter, and volatile organic compounds. Many states also voluntarily report emissions of hazardous air pollutants. Mississippi made its latest update to the NEI on December 30, 2011. EPA compiles the emissions data, supplementing it where necessary, and releases it to the general public through the Web site http://www.epa.gov/​ttn/​chief/​eiinformation.html. EPA has made the preliminary determination that Mississippi's SIP and practices are adequate for the stationary source monitoring systems related to the 1997 annual and 2006 24-hour PM_2.5 NAAQS.

7. 110(a)(2)(G) Emergency power: Section 110(a)(2)(G) requires states to provide for authority to address activities causing imminent and substantial endangerment to public health, including contingency plans to implement the emergency episode provisions in their SIPs. Today, EPA is not proposing any action with respect to element 110(a)(2)(G). This element will be addressed in a separate action.

8. 110(a)(2)(H) Future SIP revisions: DEQ is responsible for adopting air quality rules and revising SIPs as needed to attain or maintain the NAAQS in Mississippi. DEQ has the ability and authority to respond to calls for SIP revisions, and has provided a number of SIP revisions over the years for implementation of the NAAQS. Mississippi does not have any nonattainment areas for the 1997 annual or 2006 24-hour PM_2.5 standard but has submitted an infrastructure submission for these standards, which is the subject of this rulemaking. EPA has made the preliminary determination that Mississippi's SIP and practices adequately demonstrate a commitment to provide future SIP revisions related to the 1997 annual and 2006 24-hour PM_2.5 NAAQS when necessary.

9. 110(a)(2)(J) (121 consultation) Consultation with government officials: Mississippi Code Annotated Regulation 49-17-3, as well as Mississippi's Regional Haze Implementation Plan (which allows for consultation between appropriate state, local, and tribal air pollution control agencies as well as the corresponding Federal Land Managers), provide for consultation with government officials whose jurisdictions might be affected by SIP development activities. EPA has made the preliminary determination that Mississippi's SIP and practices adequately demonstrate consultation with government officials related to the 1997 annual and 2006 24-hour PM_2.5 NAAQS when necessary.

10. 110(a)(2)(J) (127 public notification) Public notification: APC-S-3—Regulations for the Prevention of Air Pollution Emergency Episodes, of the Mississippi SIP requires that DEQ notify the public of any air pollution episode or NAAQS violation. DEQ's has public notice mechanisms in place to notify the public of PM and other pollutant forecasting, including an air quality monitoring Web site providing ground level ozone alerts, http://opc.deq.state.ms.us/​aqi/​ specifically for the Jackson Metropolitan Area, DeSoto County, and the Mississippi Gulf Coast. EPA has made the preliminary determination that Mississippi's SIP and practices adequately demonstrate the State's ability to provide public notification related to the 1997 annual and 2006 24-hour PM_2.5 NAAQS when necessary.

11. 110(a)(2)(J) (PSD) PSD and visibility protection: Mississippi demonstrates its authority to regulate new and modified sources of PM to assist in the protection of air quality in Regulation APC-S-5—Regulations for the Prevention of Significant Deterioration for Air Quality. Mississippi's SIP provides the permitting requirements for new major sources or major modifications of existing sources in areas classified as attainment or unclassifiable under section 107(d)(1)(A)(ii) or (iii) of the CAA. These provisions are designed to prevent significant deterioration of air quality in areas that are in attainment of the NAAQS at the time of designations. As with infrastructure element 110(a)(2)(C), infrastructure element 110(a)(2)(J) also requires compliance with applicable provisions of the PSD program described in part C of the Act. Accordingly, final action to approve the May 18, 2011, NSR PM_2.5 Rule SIP revision, is a prerequisite to today's proposed action to approve the State's infrastructure element 110(a)(2)(J). See the discussion for element 110(a)(2)(C) above for a description of the submitted NSR PM_2.5 Rule SIP revision to the Mississippi SIP. EPA will not take final action to approve Mississippi's SIP as meeting the requirements infrastructure element 110(a)(2)(J) prior to taking final action to approve the State's May 10, 2011, NSR PM_2.5 Rule SIP revision

With regard to the applicable requirements for visibility protection, EPA recognizes that states are subject to visibility and regional haze program requirements under part C of the Act (which includes sections 169A and 169B). In the event of the establishment of a new NAAQS, however, the visibility and regional haze program requirements under part C do not change. Thus, EPA finds that there is no new visibility obligation “triggered” under section 110(a)(2)(J) when a new NAAQS becomes effective. This would be the case even in the event a secondary PM_2.5 NAAQS for visibility is established, because that NAAQS would not affect visibility requirements under part C. EPA has made the preliminary determination that Mississippi's SIP and practices adequately demonstrate the State's ability to implement PSD programs and to provide for visibility protection related to the 1997 annual and 2006 24-hour PM_2.5 NAAQS when necessary. As noted above, final approval of this element is contingent upon the Agency first taking final action to approve Mississippi's May 18, 2011, PM_2.5 NSR Update submittal.

12. 110(a)(2)(K) Air quality and modeling/data: DEQ has authority pursuant to Mississippi SIP Regulation APC-S-5—Regulations for the Prevention of Significant Deterioration for Air Quality, (which incorporates 40 CFR part 51.21 by reference) to conduct air quality modeling and report the results of such modeling to EPA. Additionally, Mississippi supports a regional effort to coordinate the development of emissions inventories and conduct regional modeling for several NAAQS, including the 1997 annual and 2006 24-hour PM_2.5 NAAQS, for the Southeastern states. Taken as a whole, Mississippi's air quality regulations demonstrate that DEQ has the authority to provide relevant data for the purpose of predicting the effect on ambient air quality of the 1997 annual and 2006 24-hour PM_2.5 NAAQS. EPA has made the preliminary determination that Mississippi's SIP and practices adequately demonstrate the State's ability to provide for air quality and modeling (including analysis of the associated data) related to the 1997 annual and 2006 24-hour PM_2.5 NAAQS when necessary.

13. 110(a)(2)(L) Permitting fees: Mississippi addresses the review of construction permits as previously discussed in 110(a)(2)(C) above. Permitting fees are collected through the State's title V fees program, which has been federally approved. EPA has made the preliminary determination that Mississippi's SIP and practices adequately provide for permitting fees related to the 1997 annual and 2006 24-hour PM_2.5 NAAQS when necessary.

14. 110(a)(2)(M) Consultation/participation by affected local entities: DEQ coordinates with local governments affected by the SIP. Specifically, as described in Section IV of Regulation APC-S-2, Public Participation and Public Availability Of Information, Mississippi requires that State and local air pollution control agencies be notified of modifications to stationary sources or the construction of new sources within their region of jurisdiction. Furthermore, DEQ has demonstrated consultation with, and participation by, affected local entities through its work with local political subdivisions during the developing of its Regional Haze Implementation Plan. EPA has made the preliminary determination that Mississippi's SIP and practices adequately demonstrate consultation with affected local entities related to the 1997 annual and 2006 24-hour PM_2.5 NAAQS when necessary.

V. Proposed Action

EPA is proposing to approve that DEQ's CAA 110(a)(1) and (2) infrastructure SIP submissions for the 1997 annual and 2006 24-hour PM_2.5 NAAQS meet the above described infrastructure SIP requirements consistent with EPA's October 2, 2007, and September 25, 2009, guidance. Mississippi's infrastructure submissions, which are the subject of today's proposed rulemaking, were submitted on December 7, 2007, for purposes of the 1997 annual PM_2.5 NAAQS, and on October 6, 2009, for purposes of the 2006 24-hour annual PM_2.5 NAAQS. This proposed approval, however, does not include infrastructure elements 110(a)(2)(E)(ii) and 110(a)(2)(G) for either the 1997 annual or 2006 24-hour PM_2.5 NAAQS. These elements will be addressed by EPA in a separate action. In addition, final approval of the infrastructure elements 110(a)(2)(C) and (J) proposed for approval today is contingent upon the Agency first taking final action to approve Mississippi's May 18, 2011, PM_2.5 NSR Update.

VI. Statutory and Executive Order Reviews

Under the CAA, the Administrator is required to approve a SIP submission that complies with the provisions of the Act and applicable Federal regulations. See 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submissions, EPA's role is to approve state choices, provided that they meet the criteria of the CAA. Accordingly, this proposed action merely approves state law as meeting Federal requirements and does not impose additional requirements beyond those imposed by state law. For that reason, this proposed action:

• Is not a “significant regulatory action” subject to review by the Office of Management and Budget under Executive Order 12866 (58 FR 51735, October 4, 1993);
• 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 Section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requirements would be inconsistent with the CAA; 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).

In addition, this rule does not have tribal implications as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), because the SIP is not approved to apply in Indian country located in the state, and EPA notes that it will not impose substantial direct costs on tribal governments or preempt tribal law.

List of Subjects in 40 CFR Part 52

• Air pollution control
• Environmental protection
• Intergovernmental relations
• Nitrogen dioxide
• Particulate matter
• Reporting and recordkeeping requirements
• Volatile organic compounds

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

Dated: June 1, 2012.

A. Stanley Meiburg,

Acting Regional Administrator, Region 4.

Footnotes

1.  As described further below in Section II, EPA is not taking on action on sections 110(a)(2)(C) nonattainment area requirements and 110(a)(2)(D)(i) interstate transport requirements.

2.  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 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 proposed 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.  This rulemaking only addresses requirements for this element as they relate to attainment areas.

4.  Today's proposed rule does not address element 110(a)(2)(D)(i) (Interstate Transport) for the 1997 and 2006 PM_2.5 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 SIP revision, which was submitted to comply with CAIR. See 72 FR 56268 (October 3, 2007). In so doing, Mississippi CAIR SIP revision addressed the interstate transport provisions in section 110(a)(2)(D)(i) for the 1997 and 2006 PM_2.5 NAAQS. In response to the remand of CAIR, EPA has recently finalized a new rule to address the interstate transport of nitrogen oxides and sulfur oxides in the eastern United States. See 76 FR 48208 (August 8, 2011) (“the Transport Rule”). That rule was recently stayed by the DC Circuit Court of Appeals. EPA's action on element 110(a)(2)(D)(i) will be addressed in a separate action.

5.  This requirement was inadvertently omitted from 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 PM_2.5 National Ambient Air Quality Standards,” and the September 25, 2009, memorandum entitled “Guidance on SIP Elements Required Under Section 110(a)(1) and (2) for the 2006 Fine Particle (PM_2.5) National Ambient Air Quality Standards,” but as mentioned above is not relevant to today's proposed rulemaking.

6.  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)(E) provides that states must provide assurances that they have adequate legal authority under state and local law to carry out the SIP; section 110(a)(2)(C) provides that states must have a substantive program to address certain sources as required by part C of the CAA; section 110(a)(2)(G) provides that states must have both legal authority to address emergencies and substantive contingency plans in the event of such an emergency.

8.  For example, section 110(a)(2)(D)(i) requires EPA to be sure 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 “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”).

9.  See Id., 70 FR 25162, at 63—65 (May 12, 2005) (explaining relationship between timing requirement of section 110(a)(2)(D) versus section 110(a)(2)(I)).

10.  EPA issued separate guidance to states with respect to SIP submissions to meet section 110(a)(2)(D)(i) for the 1997 ozone and 1997 PM_2.5 NAAQS. See “Guidance for State Implementation Plan (SIP) Submissions to Meet Current Outstanding Obligations Under Section 110(a)(2)(D)(i) for the 8-Hour Ozone and PM_2.5 National Ambient Air Quality Standards,” from William T. Harnett, Director Air Quality Policy Division OAQPS, to Regional Air Division Director, Regions I-X, dated August 15, 2006.

11.  For example, implementation of the 1997 PM_2.5 NAAQS required the deployment of a system of new monitors to measure ambient levels of that new indicator species for the new NAAQS.

12.  See “Guidance on SIP Elements Required Under Section 110(a)(1) and (2) for the 1997 8-hour Ozone and PM_2.5 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”).

13.  Id., at page 2.

14.  Id., at attachment A, page 1.

15.  Id., at page 4. In retrospect, the concerns raised by commenters with respect to EPA's approach to some substantive issues indicates that the statute is not so “self explanatory,” and indeed is sufficiently ambiguous that EPA needs to interpret it in order to explain why these substantive issues do not need to be addressed in the context of infrastructure SIPs and may be addressed at other times and by other means.

16.  See “Guidance on SIP Elements Required Under Sections 110(a)(1) and (2) for the 2006 24-Hour Fine Particle (PM_2.5) 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”).

17.  EPA has recently issued a SIP call to rectify a specific SIP deficiency related to the SSM issue. See, “Finding of Substantial Inadequacy of Implementation Plan; Call for Utah State Implementation Plan Revision,” 74 FR 21639 (April 18, 2011).

18.  EPA has recently utilized this authority to correct errors in past actions on SIP submissions related to PSD programs. See “Limitation of Approval of Prevention of Significant Deterioration Provisions Concerning Greenhouse Gas Emitting-Sources in State Implementation Plans; Final Rule,” 75 FR 82536 (December 30, 2010). EPA has previously used its authority under CAA 110(k)(6) to remove numerous other SIP provisions that the Agency determined it had approved in error. See 61 FR 38664 (July 25, 1996) and 62 FR 34641 (June 27, 1997) (corrections to American Samoa, Arizona, California, Hawaii, and Nevada SIPs); 69 FR 67062 (November 16, 2004) (corrections to California SIP); and 74 FR 57051 (November 3, 2009) (corrections to Arizona and Nevada SIPs).

19.  EPA has recently disapproved a SIP submission from Colorado on the grounds that it would have included a director's discretion provision inconsistent with CAA requirements, including section 110(a)(2)(A). See 75 FR 42342, 42344 (July 21, 2010) (proposed disapproval of director's discretion provisions); 76 FR 4540 (January 26, 2011) (final disapproval of such provisions).