Until an area is formally designated with respect to the revised O3 NAAQS, the NSR provisions applicable under that area's current designation for the 2008 O3 NAAQS (including any applicable anti-backsliding requirements) will continue to apply. That is, for areas designated as attainment/unclassifiable for the 2008 O3 NAAQS, PSD will apply for new major stationary sources and major modifications that trigger major source permitting requirements for O3; areas designated nonattainment for the 2008 O3 NAAQS must comply with the NNSR requirements for new major stationary sources and major modifications that trigger major source permitting requirements for O3. When the new designations for the revised O3 NAAQS become effective, under the current rules, those will generally serve to determine whether PSD or NNSR applies. However, the PSD regulations at 40 CFR 51.166(i)(2) and 52.21(i)(2) provide that the substantive PSD requirements do not apply for a particular pollutant if the owner or operator of the new major stationary source or major modification demonstrates that the area in which the source is located is designated nonattainment for that pollutant under CAA section 107. Thus, new major sources and modifications will generally be subject to the PSD program requirements for O3 if they are locating in an area that does not have a current nonattainment designation under CAA section 107 for O3.  These rules further provide that nonattainment designations for revoked NAAQS, as contained in 40 CFR part 81, are not viewed as current designations under CAA section 107 for purposes of determining the applicability of such PSD requirements.
      The EPA's major NSR regulations define the term "regulated NSR pollutant" to include any pollutant for which a NAAQS has been promulgated and any pollutant identified in EPA regulations as a constituent or precursor to such pollutant. Both the PSD and NNSR regulations identify VOC and NOX as precursors to O3. Accordingly, the major NSR programs for O3 are applied to emissions of VOC and NOX, as applicable, as precursors of O3.
2. Prevention of Significant Deterioration (PSD) Program
      The statutory requirements for a PSD permit program set forth under part C (sections 160 through 169 of the CAA) are addressed by the EPA's PSD regulations found at 40 CFR 51.166 (minimum requirements for an approvable PSD SIP) and 40 CFR 52.21 (PSD permitting program for permits issued under the EPA's federal permitting authority). Both sets of regulations already apply for O3 when the area is designated attainment or unclassifiable for O3 and when the new source or modification triggers PSD requirements for O3.
      For PSD, a "major stationary source" is one that emits or has the potential to emit 250 tons per year (tpy) or more of any regulated NSR pollutant, unless the new or modified source is classified under a list of 28 source categories contained in the statutory definition of "major emitting facility" in section 169(1) of the CAA. For those 28 source categories, a "major stationary source" is one that emits or has the potential to emit 100 tpy or more of any regulated NSR pollutant. A "major modification" is a physical change or a change in the method of operation of an existing major stationary source that results first, in a significant emissions increase of a regulated NSR pollutant for the project, and second, in a significant net emissions increase of that pollutant at the source. See 40 CFR 51.166(b)(2)(i), 40 CFR 52.21(b)(2)(i).
      Among other things, the PSD program requires a new major stationary source or a major modification to apply Best Available Control Technology for each applicable regulated NSR pollutant and to conduct an air quality impact analysis to demonstrate that the proposed source or project will not cause or contribute to a violation of any NAAQS or PSD increment (see CAA section 165(a)(3)-(4), 40 CFR 51.166(j)-(k), 40 CFR 52.21(j)-(k)). The PSD requirements may also include, in appropriate cases, an analysis of potential adverse impacts on Class I areas (see CAA sections 162 and 165). The EPA has interpreted the requirement for an air quality impact analysis under CAA section 165(a)(3) and the implementing regulations to include a requirement to demonstrate that emissions from the proposed facility will not cause or contribute to a violation of any NAAQS that is in effect as of the date a PSD permit is issued. See, e.g., 73 FR 28321, 28324, 28340 (May 16, 2008); 78 FR 3253 (Jan. 15, 2013); Memorandum from Stephen D. Page, Director, Office of Air Quality Planning & Standards, "Applicability of the Federal Prevention of Significant Deterioration Permit Requirements to New and Revised National Ambient Air Quality Standards" (April 1, 2010). Consistent with this interpretation, the demonstration required under CAA section 165(a)(3) and 40 CFR 51.166(k) and 52.21(k) will apply to any revised O3 NAAQS when such NAAQS become effective, except to the extent that a pending permit application is subject to a grandfathering provision that the EPA establishes through rulemaking. In addition, the other existing requirements of the PSD program will remain applicable to O3 after the revised O3 NAAQS takes effect.
      Because the complex chemistry of O3 formation in the atmosphere poses significant challenges for the assessing the impacts of individual stationary sources on O3 formation, the EPA's judgment historically has been that it is not technically sound to designate a specific air quality model that must be used in the PSD permitting process to make this demonstration for O3. To address ambient impacts of emissions from proposed individual stationary sources on O3, the EPA proposed amendments to Appendix W to 40 CFR part 51 in July 2015 that would, among other things, revise the Appendix W provisions relating to the analytical techniques for demonstrating that an individual PSD source or modification does not cause or contribute to a violation of the O3 NAAQS (80 FR 45340 July 29, 2015). Until any revisions are finalized and in effect, PSD permit applicants should continue to follow the current provisions in the applicable regulations and Appendix W in order to demonstrate that a proposed source or modification does not cause or contribute to a violation of the O3 NAAQS.
a. What Transition Plan is the EPA Providing for Implementing the PSD Requirements for the Revised O3 NAAQS?
      In this rulemaking, the EPA is amending the PSD regulations at 40 CFR 51.166 and 40 CFR 52.21 to include a grandfathering provision that will allow reviewing authorities to continue to review certain pending PSD permit applications in accordance with the O3 NAAQS that was in effect when a specific permitting milestone was reached, rather than the revised O3 NAAQS. The EPA is finalizing the grandfathering provision as proposed with two trigger dates -- the signature date of the revised O3 NAAQS rule for complete applications and the effective date of the revised O3 NAAQS for a draft permit or preliminary determination. A more detailed discussion of the final provision, comments received and our responses to those comments is provided in section VII of this preamble, which addresses regulatory changes.
b. What Screening and Compliance Demonstration Tools are Used to Implement the PSD Program?
      The EPA has historically allowed the use of screening and compliance demonstration tools to help facilitate the implementation of the NSR program by reducing the source's burden and streamlining the permitting process for circumstances where the emissions or ambient impacts of a particular pollutant could be considered de minimis. For example, the EPA has established significant emission rates, or SERs, that are used as screening tools to determine when a pollutant would be considered to be emitted in a significant amount and, accordingly, when the NSR requirements should be applied to that pollutant. See 40 CFR 51.166(b)(23) and 52.21(b)(23). For O3, the EPA established a SER of 40 tpy for emissions of each O3 precursor -- VOC and NOX. For PSD, the O3 SER applies independently for emissions of VOC and NOX to determine when the proposed major stationary source or major modification must undergo PSD review for that precursor, including complying with BACT.
      The EPA has also used for PSD a significant impact level (SIL) as a compliance demonstration tool. The SIL, expressed as an ambient concentration of a pollutant, is used first to determine the scope of the ambient impact analysis that must be completed for the applicable pollutant to satisfy the air quality demonstration requirement under CAA section 165(a)(3). Its second use is to guide the determination of whether the impact of the source is considered to cause or contribute to a violation of any NAAQS. The EPA has not established a SIL for O3.  The EPA is currently engaged in a rulemaking process to consider development of a SIL for O3. Such a SIL, if finalized, would complement proposed revisions to Appendix W mentioned above (80 FR 45340, July 29, 2015) and would assist in the implementation of the PSD air quality analysis requirement for protection of the O3 NAAQS. However, the EPA is not making such revisions in this rulemaking. Until any rulemaking to amend existing PSD regulations for O3 is completed, permitting decisions should continue to be based on the existing provisions in the applicable regulations.
      Several commenters addressed statements that the EPA made concerning screening tools for O3 in the notice of proposed rulemaking for the revised O3 NAAQS. These statements were not linked to any amendments proposed to be made (or being finalized in this action), to the PSD requirements, for O3. Therefore, the EPA is not responding to those comments at this time.
c. Other PSD Transition Issues
      The EPA anticipates that the existing O3 air quality in some areas will not meet the revised O3 NAAQS upon its effective date and that some of these areas will ultimately be designated "nonattainment" through the formal area designation process set forth under the CAA (see section VIII.B above). However, until the EPA issues such nonattainment designations, proposed new major sources and major modifications situated in any area designated attainment or unclassifiable for the 2008 O3 NAAQS will continue to be required to obtain a PSD permit. As mentioned above, the PSD permitting program requires that proposed new major stationary sources and major modifications must demonstrate that the emissions from the proposed source or modification will not cause or contribute to a violation of any NAAQS. In the notice of proposed rulemaking, the EPA provided information concerning its views on the possibility that some PSD permit applications could satisfy the air quality analysis requirements for O3 by obtaining air quality offsets (called PSD offsets). Several commenters expressed concern that without some transition provisions in the final rule exempting PSD permit applications for sources located in such areas from meeting the air quality analysis requirements for the revised O3 NAAQS, such applications might not be able to satisfy the demonstration requirement, as the current ambient air monitoring data indicate the revised lower standards are not being met. These statements were not linked to any amendments either proposed to be made to the PSD requirements for O3, or being finalized in this action. Therefore, the EPA is not responding to those comments at this time. However, the EPA notes that while it is true that the CAA prohibits a proposed major PSD source or modification from constructing unless it demonstrates that it will not cause or contribute to a violation of any NAAQS, the EPA has historically recognized in regulations and through other actions that sources applying for PSD permits may have the option of utilizing offsets as part of the required PSD demonstration under CAA section 165(a)(3)(B). The EPA is considering issuing additional guidance on how PSD offsets can be implemented.
3. Nonattainment NSR
      This section provides an explanation of some of the key requirements of the nonattainment NSR program as it applies to O3. Part D of title I of the CAA includes preconstruction review and permitting requirements for new major stationary sources and major modifications when they locate in areas designated nonattainment for a particular pollutant. The relevant part D requirements are typically referred to as the NNSR program. The EPA regulations for the NNSR program are contained at 40 CFR 51.165, 52.24 and part 51 Appendix S. The EPA's minimum requirements for a NNSR program to be approvable into a SIP are contained in 40 CFR 51.165. Appendix S to 40 CFR part 51 contains requirements constituting an interim NNSR program. This program governs NNSR permitting in nonattainment areas that lack a SIP-approved NNSR permitting program, and the interim program applies during the time between the date of the relevant nonattainment designation and the date on which the EPA approves into the SIP a NNSR program. This program is commonly known as the Emissions Offset Interpretative Rule, and is applicable to all criteria pollutants, including O3.
      The EPA is not modifying any existing NNSR requirements in this rulemaking. Under the CAA, area designations for new or revised NAAQS are addressed subsequent to the effective date of the new or revised NAAQS. If the EPA determines that any revisions to the existing NNSR requirements, including those in Appendix S, are appropriate, the EPA expects, at a later date contemporaneous with the designation process for the revised O3 NAAQS, to propose those revisions. If any changes are proposed to Appendix S requirements, the EPA anticipates that it would intend for those changes to become effective no later than the effective date of the area designations. This timing would allow air agencies that lack an approved NNSR program for O3 to use the relevant Appendix S provisions to issue NNSR permits for the revised O3 NAAQS on and after the effective date of designations of new nonattainment areas for O3 until such time as a NNSR program for O3 is approved into the SIP.
      For NNSR, "major stationary source" is generally defined as a source that emits or has the potential to emit at least 100 tpy of the pollutant for which the area is designated nonattainment. In some cases, however, the CAA and the NNSR regulations define "major stationary source" for NNSR in terms of a lower threshold, dependent on the pollutant. For O3, a threshold level of 100 tpy applies in areas classified Marginal and Moderate. Lower major source thresholds have been defined for O3 nonattainment areas in higher classifications. The NNSR program requires the review and control of emissions of both VOC and NOx as precursors of O3, and both precursors are reviewed separately in accordance with the applicable major source threshold. See, e.g., 40 CFR 51.165(a)(1)(iv)(A)(1)(i)-(iv) and (a)(1)(iv)(A)(2)(i)-(iv), respectively.
      A major modification is a physical change or change in the method of operation of an existing major stationary source that results in both a significant emissions increase and a significant net emissions increase. To determine whether an emissions increase is significant, the NNSR rules define significant emissions rates or SERs for each applicable pollutant. As noted above O3, the SER for each O3 precursor (VOC and NOx) is 40 tpy. See 40 CFR 51.165(a)(1)(x)(A). It should be noted that there are additional, more stringent SERs that apply in nonattainment areas classified as Serious, Severe or Extreme for O3. See 40 CFR 51.165(a)(1)(x)(B), (C) and (E).
      New major stationary sources and major modifications for O3 must comply with the Lowest Achievable Emission Rate (LAER) requirements as defined in the CAA and NNSR rules, and must perform other analyses and satisfy other requirements under section 173 of the CAA. For example, under CAA section 173(c) emissions reductions, known as emissions offsets, must be secured to offset the increased emissions of the air pollutant (including the relevant precursors) from the new or modified source by an equal or greater reduction, as applicable, of such pollutant. The appropriate emissions offset needed for a particular source will depend upon the classification for the O3 nonattainment area in which the source or modification will locate, such that areas with higher classifications have more stringent offset requirements. The lowest offset ratio is 1.1:1 for areas classified as Marginal, and increases to 1.5:1 for areas classified as Extreme. See, e.g., CAA section 182, 40 CFR 51.165(a)(9) and 40 CFR part 51 Appendix S section IV.G.2.
To facilitate continued economic development in nonattainment areas, many states have established offset banks or registries.  Such banks or registries can help new or modified major stationary source owners meet offset requirements by streamlining identification and access to available emissions reductions. Some states have established offset banks to help ensure a consistent method for generating, validating and transferring NOX and VOC offsets. Offsets in these areas are generated by emissions reductions that meet specific creditability criteria set forth by the SIP consistent with the EPA regulations. See 40 CFR 51.165(a)(3)(ii)(A)-(J) and part 51 Appendix S section IV.C. The EPA received comments expressing concern about the potential lack of offsets in nonattainment areas, as well as the time and resources needed for states to set up offset banks. Since the EPA did not propose, and is not finalizing, any amendments related to the NNSR offset provisions, the EPA is not responding to those comments at this time.
D. Transportation and General Conformity
1. What are Transportation and General Conformity?
Conformity is required under CAA section 176(c) to ensure that federal actions are consistent with ("conform to") the purpose of the SIP. Conformity to the purpose of the SIP means that federal activities will not cause new air quality violations, worsen existing violations, or delay timely attainment of the relevant NAAQS or interim reductions and milestones. Conformity applies to areas that are designated nonattainment, and those nonattainment areas redesignated to attainment with a CAA section 175A maintenance plan after 1990 ("maintenance areas").
The EPA's Transportation Conformity Rule (40 CFR 51.390 and part 93, subpart A) establishes the criteria and procedures for determining whether transportation activities conform to the SIP. These activities include adopting, funding or approving transportation plans, transportation improvement programs (TIPs) and federally supported highway and transit projects. For further information on conformity rulemakings, policy guidance and outreach materials, see the EPA's website at http://www.epa.gov/otaq/stateresources/transconf/index.htm. The EPA may issue future transportation conformity guidance as needed to implement a revised O3 NAAQS.
With regard to general conformity, the EPA first promulgated general conformity regulations in November 1993. (40 CFR part 51, subpart W, 40 CFR part 93, subpart B) Subsequently the EPA finalized revisions to the general conformity regulations on April 5, 2010. (75 FR 17254-17279). Besides ensuring that federal actions not covered by the transportation conformity rule will not interfere with the SIP, the general conformity program also fosters communications between federal agencies and state/local air quality agencies, provides for public notification of and access to federal agency conformity determinations, and allows for air quality review of individual federal actions. More information on the general conformity program is available at http://www.epa.gov/air/genconform/.
2. When Would Transportation and General Conformity Apply to Areas Designated Nonattainment for the Revised O3 NAAQS?
Transportation and general conformity apply one year after the effective date of nonattainment designations for the revised O3 NAAQS. This is because CAA section 176(c)(6) provides a 1-year grace period from the effective date of initial designations for any revised NAAQS before transportation and general conformity apply in areas newly designated nonattainment for a specific pollutant and NAAQS.
3. Impact of a Revised O3 NAAQS on a State's Existing Transportation and/or General Conformity SIP.
In this final rule, the EPA is revising the O3 NAAQS, but is not making specific changes to its transportation or general conformity regulations. Therefore, states should not need to revise their transportation and/or general conformity SIPs. While we are not making any revisions to the general conformity regulations at this time, we recommend, when areas develop SIPs for a revised O3 NAAQS, that state and local air quality agencies work with federal agencies with large facilities and emitting activities that are subject to the general conformity regulations to establish an emissions budget for those facilities and activities in order to facilitate future conformity determinations under the conformity regulations. Because some federal actions may not be included in such budgets in the SIP for the purpose of meeting general conformity requirements, air agencies are encouraged to maintain O3 SIP emissions inventories on an annual basis, at a minimum, to facilitate compliance of federal agencies with CAA section 176(c). Finally, states with existing conformity SIPs and new nonattainment areas may also need to revise their conformity SIPs in order to ensure the state regulations apply in any newly designated areas.
If this is the first time that transportation conformity will apply in a state, such a state is required by the statute and EPA regulations to submit a SIP revision that addresses three specific transportation conformity requirements that address consultation procedures and written commitments to control or mitigation measures associated with conformity determinations for transportation plans, TIPs or projects. (40 CFR 51.390) Additional information and guidance can be found in the EPA's "Guidance for Developing Transportation Conformity State Implementation Plans" (http://www.epa.gov/otaq/stateresources/transconf/policy/420b09001.pdf).
E. Regional and International Pollution Transport
1. Interstate Transport
The CAA contains provisions that specifically address and require regulation of the interstate transport of air pollution that does not otherwise qualify for data exclusion under the Act's exceptional event provisions.
CAA section 110(a)(2)(D)(i)(I), Interstate Transport - CAA section 110(a)(2)(D)(i)(I) requires states to develop and implement a SIP to address the interstate transport of emissions. Specifically, this provision requires the SIP to prohibit "any source or other type of emissions activity within the state" that would "significantly contribute to nonattainment" of any NAAQS in another state, or that would "interfere with maintenance" of any NAAQS in another state. When EPA promulgates or revises a NAAQS, each state is required to submit a SIP addressing this interstate transport provision within 3 years.
CAA section 126, Interstate Transport - CAA section 126(b) provides states and political subdivisions with a mechanism to petition the Administrator for a finding that "any major source or group of stationary sources emits or would emit any air pollution in violation of the prohibition of [CAA section 110(a)(2)(D)(i)(I)]." Where the EPA makes such finding, the source is allowed to operate beyond a 3-month period after such finding only if the EPA establishes emissions limitations and a compliance schedule designated to bring the source into compliance as expeditiously as practicable, but no later than three years after such finding. This mechanism is available to downwind states and political subdivisions, regardless of designation status, that would be affected by emissions from upwind states.
2. International Transport
The agency is active in work to reduce the international transport of O3 and other pollutants that can contribute to "background" O3 levels in the U.S. Under the Convention on Long-Range Transboundary Air Pollution (LRTAP) of the United Nations Economic Commission for Europe, the U.S. has been a party to the Protocol to Abate Acidification, Eutrophication, and Ground-level Ozone (known as the Gothenburg Protocol) since 2005. The U.S. is also active in the LRTAP Task Force for Hemispheric Transport of Air Pollution. The U.S. has worked bilaterally with Canada under the US-Canada Air Quality Agreement to adopt an Ozone Annex to address transboundary O3 impacts and continues to work with China on air quality management activities. This work includes supporting China's efforts to rapidly deploy power plant pollution controls that can achieve NOX reductions of at least 80 to 90%. The U.S. also continues to work bilaterally with Mexico on the Border 2020 program to support efforts to improve environmental conditions in the border region. One of the main goals of the program is to reduce air pollution, including emissions that can cause transboundary O3 impacts.
Clean Air Act section 179B recognizes the possibility that certain nonattainment areas may be heavily impacted by O3 or O3 precursor emissions from international sources beyond the regulatory jurisdiction of the state. The EPA's science review suggests that the influence of international sources on U.S. O3 levels will be largest in locations that are in the immediate vicinity of an international border with Canada or Mexico. The science review also cites two recent studies which indicate that intercontinental transport of pollution, along with other natural sources and local pollutant sources, can affect O3 air quality in the western U.S. under specific conditions. (U.S. EPA 2013, p. 3-140). Section 179B allows states to consider in their attainment demonstrations whether an area might meet the O3 NAAQS by the attainment date "but for" emissions contributing to the area originating outside the U.S. If a state is unable to demonstrate attainment in such an area after adopting all reasonably available control measures (RACM, including RACT, as required by CAA section 182(b)), the EPA can nonetheless approve the CAA-required state attainment plan and demonstration using the authority in section 179B.
When the EPA approves this type of attainment plan, states avoid potential sanctions and FIPs, and there would be no adverse consequence for a finding that the area failed to attain the NAAQS by the relevant attainment date. For example, the area would not be reclassified to the next highest classification or required to implement a section 185 penalty fee program.
Section 179B authority does not allow the EPA to avoid designating an area as nonattainment or for the area to be classified with a lower classification than is indicated by actual air quality. Generally, monitoring data influenced by international transport may not be excluded from regulatory determinations, unless the data are influenced by an excludable exceptional event. Section 179B also does not provide for any relaxation of mandatory emissions control measures (including contingency measures) or the prescribed emissions reductions necessary to achieve periodic emissions reduction progress requirements.
The EPA has used section 179B authority previously to approve attainment plans for Mexican border areas in El Paso, TX (O3, PM10, and CO plans); Nogales, AZ (PM10 plan); and Imperial Valley, CA (PM10 plan). The 1-hour O3 attainment plan for El Paso, TX was approved by EPA as sufficient to demonstrate attainment of the NAAQS by the Moderate classification deadline of November 15, 1996, taking into account "but for" international emissions sources in Ciudad Juárez, Mexico (69 FR 32450, June 10, 2004). States are encouraged to consult with their EPA Regional Office to establish appropriate technical requirements for these analyses.
IX.	Statutory and Executive Order Reviews
Additional information about these statutes and Executive Orders can be found at http://www2.epa.gov/laws-regulations/laws-and-executive-orders.
A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review
This action is an economically significant regulatory action that was submitted to the Office of Management and Budget (OMB) for review. Any changes made in response to OMB recommendations have been documented in the docket. The EPA prepared an analysis of the potential costs and benefits associated with this action. This analysis is contained in the document, Regulatory Impact Analysis of the Final National Ambient Air Quality Standards for Ground-Level Ozone, October 2015. A copy of the analysis is available in the RIA docket (EPA-HQ-OAR-2013-0169) and the analysis is briefly summarized here. The RIA estimates the costs and monetized human health and welfare benefits of attaining three alternative O3 NAAQS nationwide. Specifically, the RIA examines the alternatives of 65 ppb and 70 ppb. The RIA contains illustrative analyses that consider a limited number of emissions control scenarios that states and Regional Planning Organizations might implement to achieve these alternative O3 NAAQS. However, the CAA and judicial decisions make clear that the economic and technical feasibility of attaining ambient standards are not to be considered in setting or revising NAAQS, although such factors may be considered in the development of state plans to implement the standards. Accordingly, although an RIA has been prepared, the results of the RIA have not been considered in issuing this proposed rule.
B. Paperwork Reduction Act
The information collection requirements in this final rule have been submitted for approval to the Office of Management and Budget (OMB) under the Paperwork Reduction Act (PRA). The information collection requirements are not enforceable until OMB approves them. The Information Collection Request (ICR) document prepared by the EPA for these revisions has been assigned EPA ICR #2313.04.
      The information collected and reported under 40 CFR part 58 is needed to determine compliance with the NAAQS, to characterize air quality and associated health and ecosystems impacts, to develop emission control strategies, and to measure progress for the air pollution program. We are extending the length of the required O3 monitoring season in 32 states and the District of Columbia and the revised O3 monitoring seasons will become effective on January 1, 2017. We are also revising the PAMS monitoring requirements to reduce the number of required PAMS sites while improving spatial coverage, and requiring states in moderate or above O3 non-attainment areas and the O3 transport region to develop an enhanced monitoring plan as part of the PAMS requirements. Monitoring agencies will need to comply with the PAMS requirements by June 1, 2019. In addition, we are revising the O3 FRM to establish a new, additional technique for measuring O3 in the ambient air. It will be incorporated into the existing O3 FRM, using the same calibration procedure in Appendix D of 40 CFR part 50. We are also making changes to the procedures for testing performance characteristics and determining comparability between candidate FEMs and reference methods.
      For the purposes of ICR number 2313.04, the burden figures represent the burden estimate based on the requirements contained in this rule. The burden estimates are for the 3-year period from 2016 through 2018. The implementation of the PAMS changes will occur beyond the time frame of this ICR with implementation occurring in 2019. The cost estimates for the PAMS network (including revisions) will be captured in future routine updates to the Ambient Air Quality Surveillance ICR that are required every 3 years by OMB. The addition of a new FRM in 40 CFR part 50 and revisions to the O3 FEM procedures for testing performance characteristics in 40 CFR part 53 does not add any additional information collection requirements.
      The ICR burden estimates are associated with the changes to the O3 seasons in this final rule. This information collection is estimated to involve 158 respondents for a total cost of approximately $24,597,485 (total capital, labor, and operation and maintenance) plus a total burden of 339,930 hours for the support of all operational aspects of the entire O3 monitoring network. The labor costs associated with these hours are $20,209,966. Also included in the total are other costs of operations and maintenance of $2,254,334 and equipment and contract costs of $2,133,185. The actual labor cost increase to expand the O3 monitoring seasons is $2,064,707. In addition to the costs at the state, local, and tribal air quality management agencies, there is a burden to EPA of 41,418 hours and $2,670,360. Burden is defined at 5 CFR 1320.3(b). State, local, and tribal entities are eligible for state assistance grants provided by the federal government under the CAA which can be used for related activities. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB control number. The OMB control numbers for EPA's regulations in 40 CFR are listed in 40 CFR part 9.
C. Regulatory Flexibility Act (RFA)
I certify that this action will not have a significant economic impact on a substantial number of small entities under the RFA. This action will not impose any requirements on small entities. Rather, this rule establishes national standards for allowable concentrations of O3 in ambient air as required by section 109 of the CAA. See also American Trucking Associations v. EPA, 175 F. 3d at 1044-45 (NAAQS do not have significant impacts upon small entities because NAAQS themselves impose no regulations upon small entities). Similarly, the revisions to 40 CFR part 58 address the requirements for states to collect information and report compliance with the NAAQS and will not impose any requirements on small entities. Similarly, the addition of a new FRM in 40 CFR part 50 and revisions to the FEM procedures for testing in 40 CFR part 53 will not impose any requirements on small entities.
D. Unfunded Mandates Reform Act (UMRA)
      This action does not contain any unfunded mandate as described in UMRA, 2 U. S. C. 1531  -  1538, and does not significantly or uniquely affect small governments. Furthermore, as indicated previously, in setting a NAAQS the EPA cannot consider the economic or technological feasibility of attaining ambient air quality standards, although such factors may be considered to a degree in the development of state plans to implement the standards. See also American Trucking Associations v. EPA, 175 F. 3d at 1043 (noting that because the EPA is precluded from considering costs of implementation in establishing NAAQS, preparation of a RIA pursuant to the UMRA would not furnish any information which the court could consider in reviewing the NAAQS).
E. Executive Order 13132: Federalism
This action does not have federalism implications. It will not have substantial direct effects on the states, on the relationship between the national government and the states, or on the distribution of power and responsibilities among the various levels of government.
F. Executive Order 13175: Consultation and Coordination with Indian Tribal Governments
This action does not have tribal implications as specified in Executive Order 13175. It does not have a substantial direct effect on one or more Indian tribes as tribes are not obligated to adopt or implement any NAAQS. In addition, tribes are not obligated to conduct ambient monitoring for O3 or to adopt the ambient monitoring requirements of 40 CFR part 58. Thus, Executive Order 13175 does not apply to this action.
The EPA specifically solicited comment on this rule from tribal officials. The EPA also conducted outreach consistent with the EPA Policy on Consultation and Coordination with Indian Tribes. Outreach to tribal environmental professionals was conducted through participation in the Tribal Air call, which is sponsored by the National Tribal Air Association. Consistent with the EPA Policy on Consultation and Coordination with Indian Tribes, the EPA offered formal consultation to the tribes during the public comment period. Consultation was not requested.
G. Executive Order 13045: Protection of Children from Environmental Health & Safety Risks
This action is subject to Executive Order 13045 because it is an economically significant regulatory action as defined by Executive Order 12866, and the EPA believes that the environmental health risk addressed by this action may have a disproportionate effect on children. The rule will establish uniform NAAQS for O3; these standards are designed to protect public health with an adequate margin of safety, as required by CAA section 109. However, the protection offered by these standards may be especially important for children because children, especially children with asthma, along with other at-risk populations such as all people with lung disease and people active outdoors, are at increased risk for health effects associated with exposure to O3 in ambient air. Because children are considered an at-risk lifestage, we have carefully evaluated the environmental health effects of exposure to O3 pollution among children. Discussions of the results of the evaluation of the scientific evidence, policy considerations, and the exposure and risk assessments pertaining to children are contained in sections II.B and II.C of this preamble.
H. Executive Order 13211: Actions that Significantly Affect Energy Supply, Distribution, or Use
This action is not a "significant energy action" because it is not likely to have a significant adverse effect on the supply, distribution, or use of energy. The purpose of this rule is to establish revised NAAQS for O3, establish an additional FRM, revise FEM procedures for testing, and revises air quality surveillance requirements. The rule does not prescribe specific pollution control strategies by which these ambient standards and monitoring revisions will be met. Such strategies will be developed by states on a case-by-case basis, and the EPA cannot predict whether the control options selected by states will include regulations on energy suppliers, distributors, or users. Thus, the EPA concludes that this rule is not likely to have any adverse energy effects and does not constitute a significant energy action as defined in Executive Order 13211.
I. National Technology Transfer and Advancement Act
This rulemaking involves environmental monitoring and measurement. Consistent with the Agency's Performance Based Measurement System (PBMS), the EPA is not requiring the use of specific, prescribed analytical methods. Rather, the Agency is allowing the use of any method that meets the prescribed performance criteria. Ambient air concentrations of O3 are currently measured by the FRM in 40 CFR part 50, Appendix D (Measurement Principle and Calibration Procedure for the Measurement of Ozone in the Atmosphere) or by FEM that meet the requirements of 40 CFR part 53. Procedures are available in part 53 that allow for the approval of an FEM for O3 that is similar to the FRM. Any method that meets the performance criteria for a candidate equivalent method may be approved for use as an FEM. This approach is consistent with EPA's PBMS. The PBMS approach is intended to be more flexible and cost-effective for the regulated community; it is also intended to encourage innovation in analytical technology and improved data quality. The EPA is not precluding the use of any method, whether it constitutes a voluntary consensus standard or not, as long as it meets the specified performance criteria.
J. Executive Order 12898: Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations
The EPA believes that this action will not have disproportionately high and adverse human health or environmental effects on minority populations, low-income populations or indigenous peoples. The action described in this notice is to strengthen the NAAQS for O3.
The primary NAAQS are established at a level that is requisite to protect public health, including the health of sensitive or at-risk groups, with an adequate margin of safety. The NAAQS decisions are based on an explicit and comprehensive assessment of the current scientific evidence and associated exposure/risk analyses. More specifically, EPA expressly considers the available information regarding health effects among at-risk populations, including that available for low-income populations and minority populations, in decisions on NAAQS.  Where low-income populations or minority populations are among the at-risk populations, the decision on the standard is based on providing protection for these and other at-risk populations and lifestages.  Where such populations are not identified as at-risk populations, a NAAQS that is established to provide protection to the at-risk populations would also be expected to provide protection to all other populations, including low-income populations and minority populations.
The ISA, HREA, and PA for this review, which include identification of populations at risk from O3 health effects, are available in the docket, EPA-HQ-OAR-2008-0699.  The information on at-risk populations for this NAAQS review is summarized and considered earlier in this preamble (see section II.A). This final rule increases the level of environmental protection for all affected populations without having any disproportionately high and adverse human health or environmental effects on any population, including any minority populations, low-income populations or indigenous peoples. This rule establishes uniform national standards for O3 in ambient air that, in the Administrator's judgment, protect public health, including the health of sensitive groups, with an adequate margin of safety.
Although it is part of a separate docket (EPA-HQ-OAR-2013-0169) and is not part of the rulemaking record for this action, EPA has prepared a RIA of this decision.  As part of the RIA, a demographic analysis was conducted. While, as noted in the RIA, the demographic analysis is not a full quantitative, site-specific exposure and risk assessment, that analysis examined demographic characteristics of persons living in areas with poor air quality relative to the proposed standard. Specifically, Chapter 9, section 9.10 (page 9-7) and Appendix 9A of the RIA describe this proximity and socio-demographic analysis. This analysis found that in areas with poor air quality relative to the revised standard, the representation of minority populations was slightly greater than in the U.S. as a whole. Because the air quality in these areas does not currently meet the revised standard, populations in these areas would be expected to benefit from implementation of the strengthened standard, and, thus, would be more affected by strategies to attain the revised standard. This analysis, which evaluates the potential implications for minority populations and low-income populations of future air pollution control actions that state and local agencies may consider in implementing the revised O3 NAAQS described in this decision notice are discussed in Appendix 9A of the RIA. The RIA is available on the Web, through the EPA's Technology Transfer Network website at http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_index.html and in the RIA docket (EPA-HQ-OAR-2013-0169). As noted above, although an RIA has been prepared, the results of the RIA have not been considered in issuing this final rule.
K. Congressional Review Act (CRA)
This action is subject to the CRA, and the EPA will submit a rule report to each House of the Congress and to the Comptroller General of the United States. This action is a "major rule" as defined by 5 U.S.C. 804(2).
References
Adams, WC. (2006). Comparison of chamber 6.6 hour exposures to 0.04-0.08 ppm ozone via square-wave and triangular profiles on pulmonary responses. Inhalation Toxicol. 18: 127-136. http://dx.doi.org/10.1080/08958370500306107.
Adams, WC. (2002). Comparison of chamber and face-mask 6.6-hour exposures to ozone on pulmonary function and symptoms responses. Inhal Toxicol 14: 745-764. http://dx.doi.org/10.1080/08958370290084610.
Akinbami, LJ; Lynch, CD; Parker, JD; Woodruff, TJ. (2010). The association between childhood asthma prevalence and monitored air pollutants in metropolitan areas, United States, 2001-2004. Environ Res 110: 294-301. http://dx.doi.org/10.1016/j.envres.2010.01.001.
Alexis, N; Urch, B; Tarlo, S; Corey, P; Pengelly, D; O'Byrne, P; Silverman, F. (2000). Cyclooxygenase metabolites play a different role in ozone-induced pulmonary function decline in asthmatics compared to normals. Inhal Toxicol 12: 1205-1224.
Andersen, CP; Wilson, R; Plocher, M; Hogsett, WE. (1997). Carry-over effects of ozone on root growth and carbohydrate concentrations of ponderosa pine seedlings. Tree Physiol 17: 805-811.
American Thoracic Society. (2000a). What constitutes an adverse health effect of air pollution? Am. J. Respir. Crit. Care Med. 161: 665-673.
American Thoracic Society. (2000b). Guidelines for methacholine and exercise challenge testing  -  1999. Am. J. Respir. Crit. Care Med. 161: 309-329.
American Thoracic Society. (1985). Guidelines as to what constitutes an adverse respiratory health effect, with special reference to epidemiological studies of air pollution. Am. Rev. Respir. Dis. 131: 666-668.
Basha, MA; Gross, KB; Gwizdala, CJ; Haidar, AH; Popovich, J, Jr. (1994). Bronchoalveolar lavage neutrophilia in asthmatic and healthy volunteers after controlled exposure to ozone and filtered purified air. Chest 106: 1757-1765.
Bell, ML; Peng, RD; Dominici, F. (2006). The exposure-response curve for ozone and risk of mortality and the adequacy of current ozone regulations. Environ Health Perspect 114: 532-536.
Bloom, B; Cohen, RA; Freeman, G. (2011). Summary health statistics for U.S. children: National Health Interview Survey, 2010. National Center for Health Statistics. Vital Health Stat 10 (250). http://www.cdc.gov/nchs/data/series/sr_10/sr10_250.pdf.
Brauer, M; Blair, J; Vedal, S. (1996). Effect of ambient ozone exposure on lung function in farm workers. Am J Respir Crit Care Med 154: 981-987.
Brown, JS; Bateson, TF; McDonnell, WF. (2008). Effects of exposure to 0.06 ppm ozone on FEV1 in humans: A secondary analysis of existing data. Environ Health Perspect 116: 1023-1026. http://dx.doi.org/10.1289/ehp.11396.
Brown, JS. (2007). The effects of ozone on lung function at 0.06 ppm in healthy adults. June 14, 2007. Memo to the Ozone NAAQS Review Docket. EPA-HQ-OAR-2005-0172-0175. http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_td.html
Brunekreef, B; Hoek, G; Breugelmans, O; Leentvaar, M. (1994). Respiratory effects of low-level photochemical air pollution in amateur cyclists. Am J Respir Crit Care Med 150: 962-966.
Cakmak, S; Dales, RE; Judek, S. (2006). Respiratory health effects of air pollution gases: Modification by education and income. Arch Environ Occup Health 61: 5-10. http://dx.doi.org/10.3200/AEOH.61.1.5-10.
Campbell, SJ; Wanek, R; Coulston, JW. (2007). Ozone injury in west coast forests: 6 years of monitoring - Introduction. Portland, OR: U.S. Department of Agriculture.
Cavender, K. (2015). Summary of Final PAMS Network Design. Memorandum to the Ozone NAAQS Review Docket, EPA-HQ-OAR-2008-0699.
Cavender, K. (2014). Network Design Considerations for the PAMS Network: Memorandum to the Ozone NAAQS Review Docket, EPA-HQ-OAR-2008-0699.
Cavender, K. (2013). Revisions to the PAMS Compound Target List: Memorandum to the Ozone NAAQS Review Docket, EPA-HQ-OAR-2008-0699.
Centers for Disease Control and Prevention. (2004). The health consequences of smoking: A report of the Surgeon General. Washington, DC: U.S. Department of Health and Human Services. http://www.surgeongeneral.gov/library/smokingconsequences/
Cordell, HK; Betz, CJ; Fly, M; Mou, S; Green, GT. (2008) How do Americans View Wilderness. A WILDERNESS Research Report in the Internet Research Information Series. National Survey on Recreation and the Environment. This research is a collaborative effort between the U.S. Department of Agriculture Forest Service's Southern Research Station and its Forestry Sciences Laboratory in Athens, Georgia; the University of Georgia in Athens; and the University of Tennessee in Knoxville, Tennessee. http://warnell.forestry.uga.edu/nrrt/nsre/IRISWild/IrisWild1rptR.pdf.
Dales, RE; Cakmak, S; Doiron, MS. (2006). Gaseous air pollutants and hospitalization for respiratory disease in the neonatal period. Environ Health Perspect 114: 1751-1754. http://dx.doi.org/10.1289/ehp.9044.
Darbah, JNT; Kubiske, ME; Nelson, N; Oksanen, E; Vaapavuori, E; Karnosky, DF. (2008). Effects of decadal exposure to interacting elevated CO2 and/or O-3 on paper birch (Betula papyrifera) reproduction. Environ Pollut 155: 446-452. http://dx.doi.org/10.1016/j.envpol.2008.01.033.
Darbah, JNT; Kubiske, ME; Nelson, N; Oksanen, E; Vaapavuori, E; Karnosky, DF. (2007). Impacts of elevated atmospheric CO2 and O3 on paper birch (Betula papyrifera): Reproductive fitness. ScientificWorldJournal 7: 240-246. http://dx.doi.org/10.1100/tsw.2007.42.
Darrow, LA; Klein, M; Sarnat, JA; Mulholland, JA; Strickland, MJ; Sarnat, SE; Russell, AG; Tolbert, PE. (2011a). The use of alternative pollutant metrics in time-series studies of ambient air pollution and respiratory emergency department visits. J Expo Sci Environ Epidemiol 21: 10-19. http://dx.doi.org/10.1038/jes.2009.49.
Eresmaa, N, Karppinen, SM; Joffre, SM; Rasanene, J; Talvitie, H. (2006). Mixing Height Determination by Ceilometer, Atmospheric Chemistry and Physics, 6. 1485-1493.
Franze, T; Weller, MG; Niessner, R; Pöschl, U. (2005). Protein nitration by polluted air. Environ Sci Technol 39: 1673-1678. http://dx.doi.org/10.1021/es0488737.
Frey, HC; Samet, JM. (2012a). Letter from Dr. H. Christopher Frey, Chair and Dr. Jonathan M. Samet, Immediate Past Chair, Clean Air Scientific Advisory Committee, to Administrator Lisa P. Jackson. Re: CASAC Review of the EPA's Policy Assessment for the Review of the Ozone National Ambient Air Quality Standards (First External Review Draft  -  August 2012). EPA-CASAC-13-003. November 26, 2012.
Frey, HC; Samet, JM. (2012b). Letter from Dr. H. Christopher Frey, Chair and Dr. Jonathan M. Samet, Immediate Past Chair, Clean Air Scientific Advisory Committee, to Administrator Lisa P. Jackson. Re: CASAC Review of the EPA's Health Risk and Exposure Assessment for Ozone (First External Review Draft - Updated August 2012) and Welfare Risk and Exposure Assessment for Ozone (First External Review Draft - Updated August 2012). EPA-CASAC-13-002. November 19, 2012.
Frey, HC. (2014a). Letter from Dr. H. Christopher Frey, Chair, Clean Air Scientific Advisory Committee, to Administrator Gina McCarthy. Re: CASAC Review of the EPA's Health Risk and Exposure Assessment for Ozone (Second External Review Draft  -  February, 2014). EPA-CASAC-14-005. July 1, 2014.
Frey, HC. (2014b). Letter from Dr. H. Christopher Frey, Chair, Clean Air Scientific Advisory Committee, to Administrator Gina McCarthy. CASAC Review of the EPA's Welfare Risk and Exposure Assessment for Ozone (Second External Review Draft). EPA-CASAC-14-003. June 18, 2104.
Frey, HC. (2014c). Letter from Dr. H. Christopher Frey, Chair, Clean Air Scientific Advisory Committee, to Administrator Gina McCarthy. CASAC Review of the EPA's Second Draft Policy Assessment for the Review of the Ozone National Ambient Air Quality Standards. EPA-CASAC-14-004. June, 26, 2014.
Gielen, MH; Van Der Zee, SC; Van Wijnen, JH; Van Steen, CJ; Brunekreef, B. (1997). Acute effects of summer air pollution on respiratory health of asthmatic children. Am J Respir Crit Care Med 155: 2105-2108.
Goodman, JE; Prueitt, RL; Chandalia, J; Sax, SN. (2014). Evaluation of adverse human lung function effects in controlled ozone exposure studies. J Appl Toxicol. 34(5):516-524.
Goodman, JE; Prueitt, RL; Sax, SN; Bailey, LI; Rhomberg, LR. (2013). Evaluation of the causal framework used for setting the National Ambient Air Quality Standards, Crit. Rev. Toxicol. 43(10):829-849.
Heck, WW; Cowling, EB. (1997).The need for a long term cumulative secondary ozone standard - An ecological perspective. EM January: 23-33.
Henderson, R. (2008). Letter from Dr. Rogene Henderson, Chair, Clean Air Scientific Advisory Committee, to Administrator Stephen Johnson. Subject: Clean Air Scientific Advisory Committee Recommendations Concerning the Final Rule for the National Ambient Air Quality Standards for Ozone. EPA-CASAC-08-009. April 7, 2008.
Henderson, R. (2006). Letter from Dr. Rogene Henderson, Chair, Clean Air Scientific Advisory Committee, to Administrator Stephen Johnson. Subject: Clean Air Scientific Advisory Committee's (CASAC) Peer Review of the Agency's 2[nd] Draft Ozone Staff Paper. EPA-CASAC-07-001. October 24, 2006.
Hill, AB. (1965). The environment and disease: Association or causation? Proc R Soc Med 58: 295-300.
Hoek, G; Brunekreef, B; Kosterink, P; Van den Berg, R; Hofschreuder, P. (1993). Effect of ambient ozone on peak expiratory flow of exercising children in the Netherlands. Arch Environ Occup Health 48: 27-32. http://dx.doi.org/10.1080/00039896.1993.9938390
Holmes, T; Kramer, R. (1995). "An Independent Sample Test of Yea-Saying and StartingPoint Bias in Dichotomous-Choice Contingent Valuation." Journal of Environmental Economics and Management 28:121-132.
Hoppe, P; Peters, A; Rabe, G; Praml, G; Lindner, J; Jakobi, G; Fruhmann, G; Nowak, D. (2003). Environmental ozone effects in different population subgroups. Int J Hyg Environ Health 206: 505-516. http://dx.doi.org/10.1078/1438-4639-00250.
Horstman, DH; Ball, BA; Brown, J; Gerrity, T; Folinsbee, LJ. (1995). Comparison of pulmonary responses of asthmatic and nonasthmatic subjects performing light exercise while exposed to a low level of ozone. Toxicol Ind Health 11: 369-385.
Howden, LM; Meyer, JA. (2011). U.S. Census Bureau, 2010 Census Briefs, C2010BR-03, Age and Sex Composition: 2010, U.S. Department of Commerce, Economics and Statistics Administration, U.S. Census Bureau, Washington, DC 20233.  http://www.census.gov/prod/cen2010/briefs/c2010br-03.pdf.
Hwang, BF; Lee, YL; Lin, YC; Jaakkola, JJK; Guo, YL. (2005). Traffic related air pollution as a determinant of asthma among Taiwanese school children. Thorax 60: 467-473.
Islam, T; McConnell, R; Gauderman, WJ; Avol, E; Peters, JM; Gilliland, FD. (2008). Ozone, oxidant defense genes and risk of asthma during adolescence. Am J Respir Crit Care Med 177: 388-395. http://dx.doi.org/10.1164/rccm.200706-863OC.
Jerrett, M; Burnett, RT; Pope, CA, III; Ito, K; Thurston, G; Krewski, D; Shi, Y; Calle, E; Thun, M. (2009). Long-term ozone exposure and mortality. N Engl J Med 360: 1085-1095. http://dx.doi.org/10.1056/NEJMoa0803894.
Jorres, R; Nowak, D; Magnussen, H; Speckin, P; Koschyk, S. (1996). The effect of ozone exposure on allergen responsiveness in subjects with asthma or rhinitis. Am J Respir Crit Care Med 153: 56-64.
Katsouyanni, K; Samet, JM; Anderson, HR; Atkinson, R; Le Tertre, A; Medina, S; Samoli, E; Touloumi, G; Burnett, RT; Krewski, D; Ramsay, T; Dominici, F; Peng, RD; Schwartz, J; Zanobetti, A. (2009). Air pollution and health: A European and North American approach (APHENA). (Research Report 142). Boston, MA: Health Effects Institute. http://pubs.healtheffects.org/view.php?id=327.
Kim, CS; Alexis, NE; Rappold, AG; Kehrl, H; Hazucha, MJ; Lay, JC; Schmitt, MT; Case, M; Devlin, RB; Peden, DB; Diaz-Sanchez, D. (2011). Lung function and inflammatory responses in healthy young adults exposed to 0.06 ppm ozone for 6.6 hours. Am J Respir Crit Care Med 183: 1215-1221. http://dx.doi.org/10.1164/rccm.201011-1813OC.
King, JS; Kubiske, ME; Pregitzer, KS; Hendrey, GR; McDonald, EP; Giardina, CP; Quinn, VS; Karnosky, DF. (2005). Tropospheric O3 compromises net primary production in young stands of trembling aspen, paper birch and sugar maple in response to elevated atmospheric CO2. New Phytol 168: 623-635. http://dx.doi.org/10.1111/j.1469-8137.2005.01557.x.
Kohut, R. (2007). Assessing the risk of foliar injury from ozone on vegetation in parks in the U.S. National Park Service's Vital Signs Network. Environ Pollut 149: 348-357.
Kreit, JW; Gross, KB; Moore, TB; Lorenzen, TJ; D'Arcy, J; Eschenbacher, WL. (1989). Ozone-induced changes in pulmonary function and bronchial responsiveness in asthmatics. J Appl Physiol 66: 217-222.
Kubiske, ME; Quinn, VS; Heilman, WE; McDonald, EP; Marquardt, PE; Teclaw, RM; Friend, AL; Karnoskey, DF. (2006). Interannual climatic variation mediates elevated CO2 and O3 effects on forest growth. Global Change Biol 12: 1054-1068. http://dx.doi.org/10.1111/j.1365-2486.2006.01152.x.
Kubiske, ME; Quinn, VS; Marquardt, PE; Karnosky, DF. (2007). Effects of elevated atmospheric CO2 and/or O3 on intra- and interspecific competitive ability of aspen. Plant Biol (Stuttg) 9: 342-355. http://dx.doi.org/10.1055/s-2006-924760.
Lee, EH; Hogsett, WE. (1996). Methodology for calculating inputs for ozone secondary standard benefits analysis: Part II. Research Triangle Park, NC: U.S. Environmental Protection Agency.
Lefohn, AS; Hazucha, MJ; Shadwick, D; Adams, WC. (2010). An alternative form and level of the human health ozone standard. Inhal Toxicol 22: 999-1011. http://dx.doi.org/10.3109/08958378.2010.505253.
Lefohn, AS; Jackson, W; Shadwick, DS; Knudsen, HP. (1997). Effect of surface ozone exposures on vegetation grown in the southern Appalachian Mountains: Identification of possible areas of concern. Atmos Environ 31: 1695-1708. http://dx.doi.org/10.1016/S1352-2310(96)00258-0.
Lin, S; Bell, EM; Liu, W; Walker, RJ; Kim, NK; Hwang, SA. (2008a). Ambient ozone concentration and hospital admissions due to childhood respiratory diseases in New York State, 1991-2001. Environ Res 108: 42-47. http://dx.doi.org/10.1016/j.envres.2008.06.007.
Lin, S; Liu, X; Le, LH; Hwang, SA. (2008b). Chronic exposure to ambient ozone and asthma hospital admissions among children. Environ Health Perspect 116: 1725-1730. http://dx.doi.org/10.1289/ehp.11184.
Mar, TF; Koenig, JQ. (2009). Relationship between visits to emergency departments for asthma and ozone exposure in greater Seattle, Washington. Ann Allergy Asthma Immunol 103: 474-479.
McCarthy, G. (2012). Letter from Gina McCarthy, Assistant Administrator, U.S. Environmental Protection Agency to Robert Ukeiley. January 4, 2012. http://www.epa.gov/scram001/10thmodconf/review_material/Sierra _Club_Petition_OAR-11-002-1093.pdf.
McDonnell, WF; Stewart, PW; Smith, MV; Kim, CS; Schelegle, ES. (2012). Prediction of lung function response for populations exposed to a wide range of ozone conditions. Inhal Toxicol 24: 619-633.
McDonnell, WF; Chapman, RS; Horstman, DH; Leigh, MW; Abdul-Salaam, S. (1985). A comparison of the responses of children and adults to acute ozone exposure.
McLaughlin, SB; Nosal, M; Wullschleger, SD; Sun, G. (2007a). Interactive effects of ozone and climate on tree growth and water use in a southern Appalachian forest in the USA. New Phytol 174: 109-124. http://dx.doi.org/10.1111/j.1469-8137.2007.02018.x.
McLaughlin, SB; Wullschleger, SD; Sun, G; Nosal, M. (2007b). Interactive effects of ozone and climate on water use, soil moisture content and streamflow in a southern Appalachian forest in the USA. New Phytol 174: 125-136. http://dx.doi.org/10.1111/j.1469-8137.2007.01970.x.
Medina-Ramon, M; Zanobetti, A; Schwartz, J. (2006). The effect of ozone and PM10 on hospital admissions for pneumonia and chronic obstructive pulmonary disease: A national multicity study. Am J Epidemiol 163: 579-588. http://dx.doi.org/10.1093/aje/kwj078.
Mortimer, KM; Neas, LM; Dockery, DW; Redline, S; Tager, IB. (2002). The effect of air pollution on inner-city children with asthma. Eur Respir J 19: 699-705. http://dx.doi.org/10.1183/09031936.02.00247102.
Mudway, IS; Kelly, FJ. (2004). An investigation of inhaled ozone dose and the magnitude of airway inflammation in healthy adults. Am J Respir Crit Care Med 169: 1089-1095.
National Academy of Sciences. (1991). Rethinking the Ozone Problem in Urban and Regional Air Pollution, Committee on Tropospheric Ozone, National Resource Council, National Academy Press, Washington, D.C. 20001. ISBN: 0-309-56037-3.
National Institutes of Health, National Heart Lung and Blood Institute. (2007). Expert panel report 3: guidelines for the diagnosis and management of asthma. (07-4051). Bethesda, MD: National Institute of Health.
Nicholich, M. (2007). Some additional statistical analyses of the FEV1 pulmonary response data from the W.C. Adams data (2006). Appendix A. In: ExxonMobil comments, Docket No. EPA-HQ-OAR-2005-0172, October 9, 2007.
National Research Council. (2008). Estimating Mortality Risk Reduction and Economic Benefits from Controlling Ozone Air Pollution. Washington, DC: The National Academies Press.
Page, S. (2010). Memorandum from Stephen D. Page, Director, Office of Air Quality Planning & Standards, U.S. EPA, to Air Division Directors and Deputies, Regions I  -  X. Re:  Applicability of the Federal Prevention of Significant Deterioration Permit Requirements to New and Revised National Ambient Air Quality Standards. April 1, 2010.
Page, S. (2011). Memorandum from Stephen D. Page, Director, Office of Air Quality Planning and Standards, U.S. EPA, to Regional Air Directors, Regions I-X. Re: Guidance to Regions for Working with Tribes during the National Ambient Air Quality Standards (NAAQS) Designations Process. December 20, 2011. http://www.epa.gov/ttn/oarpg/t1/memoranda/20120117naaqsguidance.pdf.
Page, S. (2013). Memorandum from Stephen D. Page, Director, EPA Office of Air Quality Planning and Standards to Regional Air Directors, Regions I-X. Re: Guidance on Infrastructure State Implementation Plan (SIP) Elements under Clean Air Act Sections 110(a)(1) and 110(a)(2). September 13, 2013. http://www.epa.gov/oar/urbanair/sipstatus/infrastructure.html.
Phillips, SJ; Comus, PWA. (2000). Natural History of the Sonoran Desert. University of California Press, 628 pages.
Pope, CA, III; Burnett, RT; Thun, MJ; Calle, EE; Krewski, D; Ito, K; Thurston, GD. (2002). Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution. JAMA 287: 1132-1141.
Rice, J. (2014). Ozone Monitoring Season Analysis. Memorandum to the Ozone NAAQS Review Docket, EPA-HQ-OAR-2008-0699.
Riikonen, J; Kets, K; Darbah, J; Oksanen, E; Sober, A; Vapaavuori, E; Kubiske, ME; Nelson, N; Karnosky, DF. (2008). Carbon gain and bud physiology in Populus tremuloides and Betula papyrifera grown under longterm exposure to elevated concentrations of CO2 and O3. Tree Physiol 28: 243-254. http://dx.doi.org/10.1093/treephys/28.2.243.
RTI International. (2014). Gas Chromatograph (GC) Evaluation Study: Laboratory Evaluation Phase Report. http://www.epa.gov/ttnamti1/files/ambient/pams/labevalreport.pdf
Ryerson, TB; Williams, EJ; Fehsenfeld, FC. (2000). An Efficient Photolysis System for Fast-Response NO2 Measurements, Journal of Geophysical Research, Volume 105, Issue D21.
Salam, MT; Islam, T; Gauderman, WJ; Gilliland, FD. (2009). Roles of arginase variants, atopy, and ozone in childhood asthma. J Allergy Clin Immunol 123: 596-602. http://dx.doi.org/10.1016/j.jaci.2008.12.020.
Samet, JM. (2011). Letter from Dr. Jonathan M. Samet, Chair, Clean Air Scientific Advisory Committee to Administrator Lisa P. Jackson. Re: Clean Air Scientific Advisory Committee (CASAC) Response to Charge Questions on the Reconsideration of the 2008 Ozone National Ambient Air Quality Standards. EPA-CASAC-11-004. March 30, 2011.  http://yosemite.epa.gov/sab/sabproduct.nsf/0/F08BEB48C1139E2A8525785E006909AC/$File/EPA-CASAC-11-004-unsigned+.pdf.
Samet, JM. (2010). Letter from Dr. Jonathan M. Samet, Chair, Clean Air Scientific Advisory Committee to Administrator Lisa P. Jackson. Re: Review of EPA's Proposed Ozone National Ambient Air Quality Standard (Federal Register, Vol. 75, Nov. 11, January 19, 2010). EPA-CASAC-10-007. February 19, 2010. http://yosemite.epa.gov/sab/sabproduct.nsf/264cb1227d55e02c85257402007446a4/610BB57CFAC8A41C852576CF007076BD/$File/EPA-CASAC-10-007-unsigned.pdf.
Samet, JM; Bodurow, CC. (2008). Improving the presumptive disability decision-making process for veterans. In JM Samet; CC Bodurow (Eds.). Washington, DC: National Academies Press. http://www.nap.edu/openbook.php?record_id=11908
Samoli, E; Zanobetti, A; Schwartz, J; Atkinson, R; Le Tertre, A; Schindler, C; Pérez, L; Cadum, E; Pekkanen, J; Paldy, A; Touloumi, G; Katsouyanni, K. (2009). The temporal pattern of mortality responses to ambient ozone in the APHEA project. J Epidemiol Community Health 63: 960-966. http://dx.doi.org/10.1136/jech.2008.084012.
Sasser, E. (2014). Memorandum from Erika Sasser, Acting Director, Health and Environmental Impacts Division, Office of Air Quality Planing and Standards, U.S. EPA, to Holly Stallworth, Designated Federal Office, Clean Air Scientific Advisory Committee. Re:  Request for Revised Ozone HREA Chapter 7 Appendix Tables. May 9, 2014. http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_2008_rea.html.
Scannell, C; Chen, L; Aris, RM; Tager, I; Christian, D; Ferrando, R; Welch, B; Kelly, T; Balmes, JR. (1996). Greater ozone-induced inflammatory responses in subjects with asthma. Am J Respir Crit Care Med 154: 24-29.
Schelegle, ES; Adams, WC; Walby, WF; Marion, MS. (2012). Modelling of individual subject ozone exposure response kinetics. Inhal Toxicol 24: 401-415. http://dx.doi.org/10.3109/08958378.2012.683891.
Schelegle, ES; Morales, CA; Walby, WF; Marion, S; Allen, RP. (2009). 6.6-hour inhalation of ozone concentrations from 60 to 87 parts per billion in healthy humans. Am J Respir Crit Care Med 180: 265-272. http://dx.doi.org/10.1164/rccm.200809-1484OC.
Schiller, JS; Lucas, JW; Ward, BW; Peregoy, JA. (2012). Summary health statistics for U.S. adults: National Health Interview Survey, 2010. National Center for Health Statistics. Vital Health Stat 10(252). http://www.cdc.gov/nchs/data/series/sr_10/sr10_252.pdf.
Silverman, RA; Ito, K. (2010). Age-related association of fine particles and ozone with severe acute asthma in New York City. J Allergy Clin Immunol 125: 367-373. http://dx.doi.org/10.1016/j.jaci.2009.10.061.
Smith, JT. (2015). Additional Observations From WREA Datasets for Visible Foliar Injury. Memorandum to the Ozone NAAQS Review Docket, EPA-HQ-OAR-2008-0699.
Smith, G. (2012). Ambient ozone injury to forest plants in Northeast and North Central USA: 16 years of biomonitoring. Environ Monit Assess 184: 4049-4065. http://dx.doi.org/10.1007/s10661-011-2243-z.
Smith, RL; Xu, B; Switzer, P. (2009). Reassessing the relationship between ozone and short-term mortality in U.S. urban communities. Inhal Toxicol 21: 37-61. http://dx.doi.org/10.1080/08958370903161612.
Stafoggia, M; Forastiere, F; Faustini, A; Biggeri, A; Bisanti, L; Cadum, E; Cernigliaro, A; Mallone, S; Pandolfi, P; Serinelli, M; Tessari, R; Vigotti, MA; Perucci, CA. (2010). Susceptibility factors to ozone-related mortality: A population-based case-crossover analysis. Am J Respir Crit Care Med 182: 376-384. http://dx.doi.org/10.1164/rccm.200908-1269OC.
Stieb, DM; Szyszkowicz, M; Rowe, BH; Leech, JA. (2009). Air pollution and emergency department visits for cardiac and respiratory conditions: A multi-city time-series analysis. Environ Health Global Access Sci Source 8: 25. http://dx.doi.org/10.1186/1476-069X-8-25.
Strickland, MJ; Darrow, LA; Klein, M; Flanders, WD; Sarnat, JA; Waller, LA; Sarnat, SE; Mulholland, JA; Tolbert, PE. (2010). Short-term associations between ambient air pollutants and pediatric asthma emergency department visits. Am J Respir Crit Care Med 182: 307-316. http://dx.doi.org/10.1164/rccm.200908-1201OC.
Tolbert, PE; Klein, M; Peel, JL; Sarnat, SE; Sarnat, JA. (2007). Multipollutant modeling issues in a study of ambient air quality and emergency department visits in Atlanta. J Expo Sci Environ Epidemiol 17: S29-S35. http://dx.doi.org/10.1038/sj.jes.7500625.
Ulmer, C; Kopp, M; Ihorst, G; Frischer, T; Forster, J; Kuehr, J. (1997). Effects of ambient ozone exposures during the spring and summer of 1994 on pulmonary function of schoolchildren. Pediatr Pulmonol 23: 344- 353. http://dx.doi.org/10.1002/(SICI)1099-0496(199705)23:53.0.CO;2-K.
United Nations Environment Programme. (2003). Millennium Ecosystem Assessment: Ecosystems and human well-being: A framework for assessment. Washington, DC: Island Press.
U.S. Department of Agriculture, U.S. Forest Service (2014). Tree basal area data. http://www.fs.fed.us/foresthealth/technology/nidrm2012.shtml.
U.S. Department of Agriculture, National Resources Conservation Service (2014), The PLANTS Database (http://plants.usda.gov, 2014), National Plant Data Center, Baton Rouge, LA.
U.S. Department of Agriculture, Agricultural Research Service. (2012). Effects of Ozone Air Pollution on Plants. http://www.ars.usda.gov/Main/docs.htm?docid=12462.
U.S. Department of Health, Education, and Welfare. (1970). Air Quality Criteria for Photochemical Oxidants. Washington, D.C.: National Air Pollution Control Administration; publication no. AP-63. Available from NTIS, Springfield, VA; PB-190262/BA.
U.S. Environmental Protection Agency. (2015) Climate Change in the United States: Benefits of Global Action. U.S. Environmental Protection Agency. Office of Atmospheric Programs. EPA 430-F-15-001, June 2015. Available at www.epa.gov/cira.
U.S. Environmental Protection Agency. (2014a). Health Risk and Exposure Assessment for Ozone. Office of Air Quality Planning and Standards, Research Triangle Park, NC. EPA-452/P-14-004a. http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_index.html.
U.S. Environmental Protection Agency. (2014b). Welfare Risk and Exposure Assessment for Ozone. Office of Air Quality Planning and Standards, Research Triangle Park, NC. EPA-452/P-14-005a. http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_index.html.
 U.S. Environmental Protection Agency. (2014c). Policy Assessment for Ozone. Office of Air Quality Planning and Standards, Research Triangle Park, NC. EPA-452/R-14-006. http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_index.html.
U.S. Environmental Protection Agency. (2014d) Policy Assessment for Ozone, Second External Review Draft. Office of Air Quality Planning and Standards, Research Triangle Park, NC. EPA-452/P - 14 - 002.
U.S. Environmental Protection Agency (2014e). List of Designated Reference and Equivalent Methods. U.S. Environmental Protection Agency, Office of Research and Development, Research Triangle Park, NC 27711. http://epa.gov/ttn/amtic/files/ambient/criteria/reference-equivalent-methods-list.pdf.
U.S. Environmental Protection Agency (2014f). Performance of the Proposed New Federal Reference Method for Measuring Ozone Concentrations in Ambient Air. U.S. Environmental Protection Agency, Office of Research and Development, Research Triangle Park, NC. EPA/600/R-14/432.
U.S. Environmental Protection Agency (2013). Integrated Science Assessment of Ozone and Related Photochemical Oxidants (Final Report). U.S. Environmental Protection Agency, Washington, DC. EPA/600/R-10/076F. http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_2008_isa.html.
U.S. Environmental Protection Agency (2012). Integrated Science Assessment of Ozone and Related Photochemical Oxidants (Third External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-10/076C, 2012.
U.S. Environmental Protection Agency (2011a). Integrated Review Plan for the Ozone National Ambient Air Quality Standards. U.S. Environmental Protection Agency, National Center for Environmental Assessment and Office of Air Quality Planning and Standards, Research Triangle Park, NC. EPA 452/R-11-006. April 2011. http://www.epa.gov/ttn/naaqs/standards/ozone/data/2011_04_OzoneIRP.pdf
U.S. Environmental Protection Agency (2011b) Integrated Science Assessment for Ozone and Related Photochemical Oxidants: First External Review Draft, U.S. Environmental Protection Agency, Washington, DC. EPA/600/R-10/076A.
U.S. Environmental Protection Agency (2011c). Integrated Science Assessment of Ozone and Related Photochemical Oxidants (Second External Review Draft). U.S. Environmental Protection Agency, Washington, DC. EPA/600/R-10/076B.
U.S. Environmental Protection Agency (2011d). Ozone National Ambient Air Quality Standards:  Scope and Methods Plan for Health Risk and Exposure Assessment. U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Research Triangle Park, NC. EPA-452/P-11-001. April 2011. http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_2008_pd.html.
U.S. Environmental Protection Agency (2011e). Ozone National Ambient Air Quality Standards:  Scope and Methods Plan for Welfare Risk and Exposure Assessment. U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Research Triangle Park, NC. EPA-452/P-11-002. April 2011.  http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_2008_pd.html.
U.S. Environmental Protection Agency (2011f). Review of EPA's Photochemical Assessment Monitoring Stations (PAMS) Network Re-engineering Project. U.S. Environmental Protection Agency, Office of the Administrator, Science Advisory Board, Washington DC. EPA-CASAC-11-010.
U.S. Environmental Protection Agency (2010). Final Assessment: Integrated Science Assessment for Carbon Monoxide. U.S. Environmental Proteciton Agency, Washington, DC, EPA/600/R-09/019F.
U.S. Environmental Protection Agency (2009a). Assessment of the Impacts of Global Change on Regional U.S. Air Quality: A Synthesis of Climate Change Impacts on Ground Level-Ozone. An Interim Report of the U.S. EPA Global Change Research Program. U.S Environmental Protection Agency, Washington, DC. EPA/600/R - 07/094.
U.S. Environmental Protection Agency (2009b). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F, 2009.
U.S. Environmental Protection Agency (2008). Responses to Significant Comments on the 2007 Proposed Rule on the National Ambient Air Quality Standards for Ozone. U.S. Environmental Protection Agency, Washington, DC, March 2008. http://www.epa.gov/ttn/naaqs/standards/ozone/data/2008_03_rtc.pdf
U.S. Environmental Protection Agency (2007). Review of the National Ambient Air Quality Standards for Ozone: Policy Assessment of Scientific and Technical Information, OAQPS Staff Paper. EPA-452/R-07-007.
U.S. Environmental Protection Agency (2006a). Air Quality Criteria for Ozone and Related Photochemical Oxidants (2006 Final). U.S. Environmental Protection Agency, Washington, DC. EPA/600/R-05/004aF-cF. March 2006. http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_cd.html.
U.S. Environmental Protection Agency (2006b). Ecological Benefits Assessment Strategic Plan. EPA-240-R-06-001. Office of Administrator, Washington, DC. http://yosemite.epa.gov/ee/epa/eed.nsf/webpages/ecologbenefitsplan.html.
U.S. Environmental Protection Agency (2005). Guidelines for carcinogen risk assessment. Risk Assessment Forum, U.S. EPA, Washington, DC. EPA/630/P-03/001F. http://www.epa.gov/cancerguidelines/.
U.S. Environmental Protection Agency (1999). Compendium Method TO-11A, Determination of Formaldehyde in Ambient Air using Adsorbent Cartridge Followed by High Performance Liquid Chromatography (HPLC). U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH. EPA/625/R-96/010b.
U.S. Environmental Protection Agency (1998). Technical Assistance Document (TAD) for Sampling and Analysis of Ozone Precursors. U.S. Environmental Protection Agency, Office of Research and Development, Research Triangle Park. EPA/600-R-98/161.
U.S. Environmental Protection Agency (1996a). Air quality criteria for ozone and related photochemical oxidants. U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA/600/P-93/004aF, cF
U.S. Environmental Protection Agency (1996b). Review of national ambient air quality standards for ozone: Assessment of scientific and technical information: OAQPS staff paper. Office of Air Quality Planning and Standards, Research Triangle Park, NC. EPA/452/R-96/007. http://www.ntis.gov/search/product.aspx?ABBR=PB96203435
U.S. Environmental Protection Agency (1992). Summary of selected new information on effects of ozone on health and vegetation: supplement to 1986 air quality criteria for ozone and other photochemical oxidants. Research Triangle Park, NC: Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office; EPA report no. EPA/600/8-88/105F. Available from NTIS, Springfield, VA; PB92-235670.
U.S. Environmental Protection Agency (1989). Review of the National Ambient Air Quality Standards for Ozone: Policy Assessment of Scientific and Technical Information. OAQPS Staff Paper. Office of Air Quality Planning and Standards, Research Triangle Park, NC.
U.S. Environmental Protection Agency (1986). Air quality criteria for ozone and other photochemical oxidants. Research Triangle Park, NC. EPA-600/8-84-020aF - EPA-600/8-84-020eF. http://www.ntis.gov/search/product.aspx?ABBR=PB87142949.
U.S. Environmental Protection Agency (1978). Air quality criteria for ozone and other photochemical oxidants. Washington, DC. EPA/600/8-78/004.
U.S. Forest Service; National Park Service; U.S. Fish and Wildlife Service. (2010). Federal land managers' air quality related values work group (FLAG): phase I report -- revised (2010). Natural Resource Report NPS/NRPC/NRR -- 2010/232. National Park Service, Denver, CO. http://www.nature.nps.gov/air/Pubs/pdf/flag/FLAG_2010.pdf.
U.S. National Park Service. (2003). Ozone Sensitive Plant Species on National Park Service and U.S. Fish and Wildlife Service Lands: Results of a June 24-25, 2003 Workshop. Baltimore, MD. http://www.nature.nps.gov/air/pubs/pdf/baltfinalreport1.pdf.
U.S. National Park Service. (2006). Ozone Sensitive Plant Species, by Park, November 2006.  http://www.nature.nps.gov/air/Permits/ARIS/docs/Ozone_Sensitive_ByPark_3600.pdf.
Ulmer, C; Kopp, M; Ihorst, G; Frischer, T; Forster, J; Kuehr, J. (1997). Effects of ambient ozone exposures during the spring and summer of 1994 on pulmonary function of schoolchildren. Pediatr Pulmonol 23: 344-353. http://dx.doi.org/10.1002/(SICI)1099-0496(199705)23:5<344::AID-PPUL6>3.0.CO;2-K.
Vagaggini, B; Cianchetti, S; Bartoli, M; Ricci, M; Bacci, E; Dente, FL; Di Franco, A; Paggiaro, P. (2007). Prednisone blunts airway neutrophilic inflammatory response due to ozone exposure in asthmatic subjects. Respiration 74: 61-58. http://dx.doi.org/10.1159/000096078.
Vagaggini, B; Taccola, M; Conti, I; Carnevali, S; Cianchetti, S; Bartoli, ML; Bacci, E; Dente, FL; Di Franco, A; Giannini, D; Paggiaro, PL. (2001). Budesonide reduces neutrophilic but not functional airway response to ozone in mild asthmatics. Am J Respir Crit Care Med 164: 2172-2176.
Vedal, S; Brauer, M; White, R; Petkau, J. (2003). Air pollution and daily mortality in a city with low levels of pollution. Environ. Health Perspect. 111: 45 - 51.
Villeneuve, PJ; Chen, L; Rowe, BH; Coates, F. (2007). Outdoor air pollution and emergency department visits for asthma among children and adults: A case-crossover study in northern Alberta, Canada. Environ Health Global Access Sci Source 6: 40. http://dx.doi.org/10.1186/1476-069X-6-40.
Wegman, LN. (2012) Memorandum from Lydia N. Wegman, Director, Health and Environmental Impacts Division, Office of Air Quality Planning and Standards, U.S. EPA, to Holly Stallworth, Designated Federal Officer, Clean Air Scientific Advisory Committee. Re: Updates to Information Presented in the Scope and Methods Plans for the Ozone NAAQS Health and Welfare Risk and Exposure Assessments. May 2, 2012.
Wells, B. (2015a). Memorandum to the Ozone NAAQS Review Docket, EPA-HQ-OAR-2008-0699.
Wells, B. (2015b). Expanded Comparison of Ozone Metrics Considered in Current NAAQS Review. Memorandum to the Ozone NAAQS Review Docket, EPA-HQ-OAR-2008-0699.
Wells, B. (2014a). Comparison of Ozone Metrics Considered in Current NAAQS Review. Memorandum to the Ozone NAAQS Review Docket, EPA-HQ-OAR-2008-0699.
Wells, B. (2014b). Analysis of Overlapping 8-hour Daily Maximum Ozone Concentrations. Memorandum to the Ozone NAAQS Review Docket, EPA-HQ-OAR-2008-0699.
Wittig, VE; Ainsworth, EA; Naidu, SL; Karnosky, DF; Long, SP. (2009). Quantifying the impact of current and future tropospheric ozone on tree biomass, growth, physiology and biochemistry: A quantitative meta-analysis. Global Change Biol 15: 396-424. http://dx.doi.org/10.1111/j.1365-2486.2008.01774.x.
Wittig, VE; Ainsworth, EA; Long, SP. (2007). To what extent do current and projected increases in surface ozone affect photosynthesis and stomatal conductance of trees? A meta-analytic review of the last 3 decades of experiments [Review]. Plant Cell Environ 30: 1150-1162. http://dx.doi.org/10.1111/j.1365-3040.2007.01717.x.
Wolff, GT. (1995). Letter to EPA Administrator Carol Browner: "CASAC Closure on the Primary Standard Portion of the Staff Paper for Ozone," EPA-SAB-CASAC-LTR-96-002, November 30, 1995.
Wong, CM; Vichit-Vadakan, N; Vajanapoom, N; Ostro, B; Thach, TQ; Chau, PY; Chan, EK; Chung, RY; Ou, CQ; Yang, L; Peiris, JS; Thomas, GN; Lam, TH; Wong, TW; Hedley, AJ; Kan, H; Chen, B; Zhao, N; London, SJ; Song, G; Chen, G; Zhang, Y; Jiang, L; Qian, Z; He, Q; Lin, HM; Kong, L; Zhou, D; Liang, S; Zhu, Z; Liao, D; Liu, W; Bentley, CM; Dan, J; Wang, B; Yang, N; Xu, S; Gong, J; Wei, H; Sun, H; Qin, Z. (2010). Part 5. Public health and air pollution in Asia (PAPA): A combined analysis of four studies of air pollution and mortality. In Public Health and Air Pollution in Asia (PAPA): Coordinated Studies of Short-Term Exposure to Air Pollution and Daily Mortality in Four Cities (pp. 377-418). Boston, MA: Health Effects Institute. http://pubs.healtheffects.org/view.php?id=348.
Zanobetti, A; Schwartz, J. (2011). Ozone and survival in four cohorts with potentially predisposing diseases. Am J Respir Crit Care Med 184: 836-841. http://dx.doi.org/10.1164/rccm.201102-0227OC.
Zanobetti, A; Schwartz, J. (2008). Mortality displacement in the association of ozone with mortality: An analysis of 48 cities in the United States. Am J Respir Crit Care Med 177: 184-189. http://dx.doi.org/10.1164/rccm.200706-823OC.
Zanobetti, A; Schwartz, J. (2006). Air pollution and emergency admissions in Boston, MA. J Epidemiol Community Health 60: 890-895. http://dx.doi.org/10.1136/jech.2005.039834.

List of Subjects

40 CFR Part 50

Environmental protection, Air pollution control, Carbon monoxide, Lead, Nitrogen dioxide, Ozone, Particulate matter, Sulfur oxides.
40 CFR Part 51
Environmental protection, Administrative practices and procedures, Air pollution control, Intergovernmental relations.
40 CFR Part 52
Environmental Protection, Administrative practices and procedures, Air pollution control, Incorporation by reference, Intergovernmental relations.
40 CFR Part 53
Environmental protection, Administrative practice and procedure, Air pollution control, Reporting and recordkeeping requirements
40 CFR Part 58
Environmental protection, Administrative practice and procedure, Air pollution control, Intergovernmental relations, Reporting and recordkeeping requirements

________________________________
Dated:

_________________________________
Gina McCarthy,
Administrator.
For the reasons set forth in the preamble, chapter I of title 40 of the Code of Federal Regulations is proposed to be amended as follows:

PART 50  -  NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY STANDARDS
1.	The authority citation for part 50 continues to read as follows:
Authority: 42 U.S.C. 7401 et seq.
2.	Amend §50.14 by:
a. Revising paragraphs (c)(2)(iii), (vi), and (3)(i);
b. Removing and reserving paragraphs (c)(2)(iv), (v), (3)(ii) and (iii);
3. The revisions read as follows:
§ 50.14 Treatment of air quality monitoring data influenced by exceptional events.
* * * * *
(c) ***
(2) ***
(iii) Flags placed on data as being due to an exceptional event together with an initial description of the event shall be submitted to EPA not later than July 1st of the calendar year following the year in which the flagged measurement occurred, except as allowed under paragraph (c)(2)(vi) of this section.
* * * * *
(vi) Table 1 identifies the data submission process for a new or revised NAAQS. This process shall apply to those data that will or may influence the initial designation of areas for any new or revised NAAQS.
Table 1. Schedule for Flagging and Documentation Submission for Data Influenced by Exceptional Events for Use in Initial Area Designations
                    Exceptional Events / Regulatory Action
                    Exceptional Events Deadline Schedule[d]

Flagging and initial event description deadline for data years 1, 2 and 3.[a]
If state and tribal initial designation recommendations for a new/revised NAAQS are due August through January, then the flagging and initial event description deadline will be the July 1 prior to the recommendation deadline. If state and tribal recommendations for a new/revised NAAQS are due February through July, then the flagging and initial event description deadline will be the January 1 prior to the recommendation deadline.
Exceptional events demonstration submittal deadline for data years 1, 2 and 3.[a]
No later than the date that state and tribal recommendations are due to EPA.
Flagging, initial event description and exceptional events demonstration submittal deadline for data year 4[b] and, where applicable, data year 5.[c]
By the last day of the month that is 1 year and 7 months after promulgation of a new/revised NAAQS, unless either option a or b applies.
a.	If the EPA follows a 3-year designation schedule, the deadline is 2 years and 7 months after promulgation of a new/revised NAAQS.
b.	If the EPA notifies the state/tribe that it intends to complete the initial area designations process according to a schedule between 2 and 3 years, the deadline is 5 months prior to the date specified for final designations decisions in such EPA notification.
a Where data years 1, 2, and 3 are those years expected to be considered in state and tribal recommendations.
[b] Where data year 4 is the additional year of data that the EPA may consider when it makes final area designations for a new/revised NAAQS under the standard designations schedule.
c Where data year 5 is the additional year of data that the EPA may consider when it makes final area designations for a new/revised NAAQS under an extended designations schedule.
d The date by which air agencies must certify their ambient air quality monitoring data in AQS is annually on May 1 of the year following the year of data collection as specified in 40 CFR 58.15(a)(2). In some cases, however, air agencies may choose to certify a prior year's data in advance of May 1 of the following year, particularly if the EPA has indicated its intent to promulgate final designations in the first 8 months of the calendar year. Data flagging, initial event description and exceptional events demonstration deadlines for "early certified" data will follow the deadlines for "year 4" and "year 5" data.

 (3) Submission of demonstrations. (i) Except as allowed under paragraph (c)(2)(vi) of this section, a State that has flagged data as being due to an exceptional event and is requesting exclusion of the affected measurement data shall, after notice and opportunity for public comment, submit a demonstration to justify data exclusion to EPA not later than the lesser of 3 years following the end of the calendar quarter in which the flagged concentration was recorded or 12 months prior to the date that a regulatory decision must be made by EPA. A State must submit the public comments it received along with its demonstration to EPA.
* * * * *
4. Section 50.19 is added to read as follows:

§ 50.19 National primary and secondary ambient air quality standards for ozone.

(a) The level of the national 8-hour primary ambient air quality standard for ozone (O3) is 0.070 parts per million (ppm), daily maximum 8-hour average, measured by a reference method based on appendix D to this part and designated in accordance with part 53 of this chapter or an equivalent method designated in accordance with part 53 of this chapter.
(b) The 8-hour primary O3 ambient air quality standard is met at an ambient air quality monitoring site when the 3-year average of the annual fourth-highest daily maximum 8-hour average O3 concentration is less than or equal to 0.070 ppm, as determined in accordance with appendix U to this part.
(c) The level of the national secondary ambient air quality standard for O3 is 0.070 ppm, daily maximum 8-hour average, measured by a reference method based on appendix D to this part and designated in accordance with part 53 of this chapter or an equivalent method designated in accordance with part 53 of this chapter.
(d) The 8-hour secondary O3 ambient air quality standard is met at an ambient air quality monitoring site when the 3-year average of the annual fourth-highest daily maximum 8-hour average O3 concentration is less than or equal to 0.070 ppm, as determined in accordance with appendix U to this part.
5. Revise appendix D to part 50 under subchapter C to read as follows:
      Appendix D to Part 50  --  Reference Measurement Principle and Calibration Procedure for the Measurement of Ozone in the Atmosphere (Chemiluminescence Method)
      1.0 Applicability.
      1.1 This chemiluminescence method provides reference measurements of the concentration of ozone (O3) in ambient air for determining compliance with the national primary and secondary ambient air quality standards for O3 as specified in 40 CFR part 50. This automated method is applicable to the measurement of ambient O3 concentrations using continuous (real-time) sampling and analysis. Additional quality assurance procedures and guidance are provided in 40 CFR part 58, appendix A, and in Reference 14.
      2.0 Measurement Principle.
      2.1 This reference method is based on continuous automated measurement of the intensity of the characteristic chemiluminescence released by the gas phase reaction of O3 in sampled air with either ethylene (C2H4) or nitric oxide (NO) gas. An ambient air sample stream and a specific flowing concentration of either C2H4 (ET-CL method) or NO (NO-CL method) are mixed in a measurement cell, where the resulting chemiluminescence is quantitatively measured by a sensitive photo-detector. References 8-11 describe the chemiluminescence measurement principle.
      2.2 The measurement system is calibrated by referencing the instrumental chemiluminescence measurements to certified O3 standard concentrations generated in a dynamic flow system and assayed by photometry to be traceable to a National Institute of Standards and Technology (NIST) standard reference photometer for O3 (see Section 4, Calibration Procedure, below).
      2.3 An analyzer implementing this measurement principle is shown schematically in Figure 1. Designs implementing this measurement principle must include: an appropriately designed mixing and measurement cell; a suitable quantitative photometric measurement system with adequate sensitivity and wave length specificity for O3; a pump, flow control, and sample conditioning system for sampling the ambient air and moving it into and through the measurement cell; a sample air dryer as necessary to meet the water vapor interference limit requirement specified in subpart B of part 53 of this chapter; a means to supply, meter, and mix a constant, flowing stream of either C2H4 or NO gas of fixed concentration with the sample air flow in the measurement cell; suitable electronic control and measurement processing capability; and other associated apparatus as may be necessary. The analyzer must be designed and constructed to provide accurate, repeatable, and continuous measurements of O3 concentrations in ambient air, with measurement performance that meets the requirements specified in subpart B of part 53 of this chapter.
      2.4 An analyzer implementing this measurement principle and calibration procedure will be considered a federal reference method (FRM) only if it has been designated as a reference method in accordance with part 53 of this chapter.
      2.5 Sampling considerations. The use of a particle filter on the sample inlet line of a chemiluminescence O3 FRM analyzer is required to prevent buildup of particulate matter in the measurement cell and inlet components. This filter must be changed weekly (or at least often as specified in the manufacturer's operation/instruction manual), and the sample inlet system used with the analyzer must be kept clean, to avoid loss of O3 in the O3 sample air prior to the concentration measurement.
      3.0 Interferences.
      3.1 Except as described in 3.2 below, the chemiluminescence measurement system is inherently free of significant interferences from other pollutant substances that may be present in ambient air.
      3.2 A small sensitivity to variations in the humidity of the sample air is minimized by a sample air dryer. Potential loss of O3 in the inlet air filter and in the air sample handling components of the analyzer and associated exterior air sampling components due to buildup of airborne particulate matter is minimized by filter replacement and cleaning of the other inlet components.
      4.0 Calibration Procedure.
      4.1 Principle. The calibration procedure is based on the photometric assay of O3 concentrations in a dynamic flow system. The concentration of O3 in an absorption cell is determined from a measurement of the amount of 254 nm light absorbed by the sample. This determination requires knowledge of (1) the absorption coefficient (α) of O3 at 254 nm, (2) the optical path length (l) through the sample, (3) the transmittance of the sample at a nominal wavelength of 254 nm, and (4) the temperature (T) and pressure (P) of the sample. The transmittance is defined as the ratio I/I0, where I is the intensity of light which passes through the cell and is sensed by the detector when the cell contains an O3 sample, and I0 is the intensity of light which passes through the cell and is sensed by the detector when the cell contains zero air. It is assumed that all conditions of the system, except for the contents of the absorption cell, are identical during measurement of I and I0. The quantities defined above are related by the Beer-Lambert absorption law,
      Transmitance= II0=e -αcl       				 (1)
      where:
      α = absorption coefficient of O3 at 254 nm = 308 +-4 atm−1 cm−1 at 0 °C and 760 torr,[1, 2, 3, 4, 5, 6, 7]
      c = O3 concentration in atmospheres, and
      l = optical path length in cm.
      A stable O3 generator is used to produce O3 concentrations over the required calibration concentration range. Each O3 concentration is determined from the measurement of the transmittance (I/I0) of the sample at 254 nm with a photometer of path length l and calculated from the equation,
      catm=-1αllnII0						(2a)
      or
      cppm=-106αllnII0.					(2b)
      The calculated O3 concentrations must be corrected for O3 losses, which may occur in the photometer, and for the temperature and pressure of the sample.
      4.2 Applicability. This procedure is applicable to the calibration of ambient air O3 analyzers, either directly or by means of a transfer standard certified by this procedure. Transfer standards must meet the requirements and specifications set forth in Reference 12.
      4.3 Apparatus. A complete UV calibration system consists of an O3 generator, an output port or manifold, a photometer, an appropriate source of zero air, and other components as necessary. The configuration must provide a stable O3 concentration at the system output and allow the photometer to accurately assay the output concentration to the precision specified for the photometer (4.3.1). Figure 2 shows a commonly used configuration and serves to illustrate the calibration procedure, which follows. Other configurations may require appropriate variations in the procedural steps. All connections between components in the calibration system downstream of the O3 generator must be of glass, Teflon, or other relatively inert materials. Additional information regarding the assembly of a UV photometric calibration apparatus is given in Reference 13. For certification of transfer standards which provide their own source of O3, the transfer standard may replace the O3 generator and possibly other components shown in Figure 2; see Reference 12 for guidance.
      4.3.1 UV photometer. The photometer consists of a low-pressure mercury discharge lamp, (optional) collimation optics, an absorption cell, a detector, and signal-processing electronics, as illustrated in Figure 2. It must be capable of measuring the transmittance, I/I0, at a wavelength of 254 nm with sufficient precision such that the standard deviation of the concentration measurements does not exceed the greater of 0.005 ppm or 3% of the concentration. Because the low-pressure mercury lamp radiates at several wavelengths, the photometer must incorporate suitable means to assure that no O3 is generated in the cell by the lamp, and that at least 99.5% of the radiation sensed by the detector is 254 nm radiation. (This can be readily achieved by prudent selection of optical filter and detector response characteristics.) The length of the light path through the absorption cell must be known with an accuracy of at least 99.5%. In addition, the cell and associated plumbing must be designed to minimize loss of O3 from contact with cell walls and gas handling components. See Reference 13 for additional information.
      4.3.2 Air flow controllers. Air flow controllers are devices capable of regulating air flows as necessary to meet the output stability and photometer precision requirements.
      4.3.3 Ozone generator. The ozone generator used must be capable of generating stable levels of O3 over the required concentration range.
      4.3.4 Output manifold. The output manifold must be constructed of glass, Teflon, or other relatively inert material, and should be of sufficient diameter to insure a negligible pressure drop at the photometer connection and other output ports. The system must have a vent designed to insure atmospheric pressure in the manifold and to prevent ambient air from entering the manifold.
      4.3.5 Two-way valve. A manual or automatic two-way valve, or other means is used to switch the photometer flow between zero air and the O3 concentration.
      4.3.6 Temperature indicator. A device to indicate temperature must be used that is accurate to +-1 °C.
      4.3.7 Barometer or pressure indicator. A device to indicate barometric pressure must be used that is accurate to +-2 torr.
      4.4 Reagents.
      4.4.1 Zero air. The zero air must be free of contaminants which would cause a detectable response from the O3 analyzer, and it must be free of NO, C2H4, and other species which react with O3. A procedure for generating suitable zero air is given in Reference 13. As shown in Figure 2, the zero air supplied to the photometer cell for the I0 reference measurement must be derived from the same source as the zero air used for generation of the O3 concentration to be assayed (I measurement). When using the photometer to certify a transfer standard having its own source of O3, see Reference 12 for guidance on meeting this requirement.
      4.5 Procedure.
      4.5.1 General operation. The calibration photometer must be dedicated exclusively to use as a calibration standard. It must always be used with clean, filtered calibration gases, and never used for ambient air sampling. A number of advantages are realized by locating the calibration photometer in a clean laboratory where it can be stationary, protected from the physical shock of transportation, operated by a responsible analyst, and used as a common standard for all field calibrations via transfer standards.
      4.5.2 Preparation. Proper operation of the photometer is of critical importance to the accuracy of this procedure. Upon initial operation of the photometer, the following steps must be carried out with all quantitative results or indications recorded in a chronological record, either in tabular form or plotted on a graphical chart. As the performance and stability record of the photometer is established, the frequency of these steps may be reduced to be consistent with the documented stability of the photometer and the guidance provided in Reference 12.
      <IP_ADDRESS> Instruction manual. Carry out all set up and adjustment procedures or checks as described in the operation or instruction manual associated with the photometer.
      <IP_ADDRESS> System check. Check the photometer system for integrity, leaks, cleanliness, proper flow rates, etc. Service or replace filters and zero air scrubbers or other consumable materials, as necessary.
      <IP_ADDRESS> Linearity. Verify that the photometer manufacturer has adequately established that the linearity error of the photometer is less than 3%, or test the linearity by dilution as follows: Generate and assay an O3 concentration near the upper range limit of the system or appropriate calibration scale for the instrument, then accurately dilute that concentration with zero air and re-assay it. Repeat at several different dilution ratios. Compare the assay of the original concentration with the assay of the diluted concentration divided by the dilution ratio, as follows
      E= A1- A2/RA1 x100%					(3)
      where:
      E = linearity error, percent
      A1 = assay of the original concentration
      A2 = assay of the diluted concentration
      R = dilution ratio = flow of original concentration divided by the total flow
      The linearity error must be less than 5%. Since the accuracy of the measured flow-rates will affect the linearity error as measured this way, the test is not necessarily conclusive. Additional information on verifying linearity is contained in Reference 13.
      <IP_ADDRESS> Inter-comparison. The photometer must be inter-compared annually, either directly or via transfer standards, with a NIST standard reference photometer (SRP) or calibration photometers used by other agencies or laboratories.
      <IP_ADDRESS> Ozone losses. Some portion of the O3 may be lost upon contact with the photometer cell walls and gas handling components. The magnitude of this loss must be determined and used to correct the calculated O3 concentration. This loss must not exceed 5%. Some guidelines for quantitatively determining this loss are discussed in Reference 13.
      4.5.3 Assay of O3 concentrations. The operator must carry out the following steps to properly assay O3 concentrations.
      <IP_ADDRESS> Allow the photometer system to warm up and stabilize.
      <IP_ADDRESS> Verify that the flow rate through the photometer absorption cell, F, allows the cell to be flushed in a reasonably short period of time (2 liter/min is a typical flow). The precision of the measurements is inversely related to the time required for flushing, since the photometer drift error increases with time.
      <IP_ADDRESS> Ensure that the flow rate into the output manifold is at least 1 liter/min greater than the total flow rate required by the photometer and any other flow demand connected to the manifold.
      <IP_ADDRESS> Ensure that the flow rate of zero air, Fz, is at least 1 liter/min greater than the flow rate required by the photometer.
      <IP_ADDRESS> With zero air flowing in the output manifold, actuate the two-way valve to allow the photometer to sample first the manifold zero air, then Fz. The two photometer readings must be equal (I = I0).
      Note: In some commercially available photometers, the operation of the two-way valve and various other operations in section 4.5.3 may be carried out automatically by the photometer.
      <IP_ADDRESS> Adjust the O3 generator to produce an O3 concentration as needed.
      <IP_ADDRESS> Actuate the two-way valve to allow the photometer to sample zero air until the absorption cell is thoroughly flushed and record the stable measured value of Io.
      <IP_ADDRESS> Actuate the two-way valve to allow the photometer to sample the O3 concentration until the absorption cell is thoroughly flushed and record the stable measured value of I.
      <IP_ADDRESS> Record the temperature and pressure of the sample in the photometer absorption cell. (See Reference 13 for guidance.)
      <IP_ADDRESS> Calculate the O3 concentration from equation 4. An average of several determinations will provide better precision.
      [O3]OUT= -1αllnII0T273760Px106L 				(4)
      where:
      [O3]OUT = O3 concentration, ppm
      α = absorption coefficient of O3 at 254 nm = 308 atm−1 cm−1 at 0° C and 760 torr
      l = optical path length, cm
      T = sample temperature, K
      P = sample pressure, torr
      L = correction factor for O3 losses from <IP_ADDRESS> = (1−fraction of O3 lost).
      Note: Some commercial photometers may automatically evaluate all or part of equation 4. It is the operator's responsibility to verify that all of the information required for equation 4 is obtained, either automatically by the photometer or manually. For "automatic" photometers which evaluate the first term of equation 4 based on a linear approximation, a manual correction may be required, particularly at higher O3 levels. See the photometer instruction manual and Reference 13 for guidance.
      <IP_ADDRESS> Obtain additional O3 concentration standards as necessary by repeating steps <IP_ADDRESS> to <IP_ADDRESS> or by Option 1.
      4.5.4 Certification of transfer standards. A transfer standard is certified by relating the output of the transfer standard to one or more O3 calibration standards as determined according to section 4.5.3. The exact procedure varies depending on the nature and design of the transfer standard. Consult Reference 12 for guidance.
      4.5.5 Calibration of ozone analyzers. Ozone analyzers must be calibrated as follows, using O3 standards obtained directly according to section 4.5.3 or by means of a certified transfer standard.
      <IP_ADDRESS> Allow sufficient time for the O3 analyzer and the photometer or transfer standard to warm-up and stabilize.
      <IP_ADDRESS> Allow the O3 analyzer to sample zero air until a stable response is obtained and then adjust the O3 analyzer's zero control. Offsetting the analyzer's zero adjustment to +5% of scale is recommended to facilitate observing negative zero drift (if any). Record the stable zero air response as "Z".
      <IP_ADDRESS> Generate an O3 concentration standard of approximately 80% of the desired upper range limit (URL) of the O3 analyzer. Allow the O3 analyzer to sample this O3 concentration standard until a stable response is obtained.
      <IP_ADDRESS> Adjust the O3 analyzer's span control to obtain the desired response equivalent to the calculated standard concentration. Record the O3 concentration and the corresponding analyzer response. If substantial adjustment of the span control is necessary, recheck the zero and span adjustments by repeating steps <IP_ADDRESS> to <IP_ADDRESS>.
      <IP_ADDRESS> Generate additional O3 concentration standards (a minimum of 5 are recommended) over the calibration scale of the O3 analyzer by adjusting the O3 source or by Option 1. For each O3 concentration standard, record the O3 concentration and the corresponding analyzer response.
      <IP_ADDRESS> Plot the O3 analyzer responses (vertical or Y-axis) versus the corresponding O3 standard concentrations (horizontal or X-axis). Compute the linear regression slope and intercept and plot the regression line to verify that no point deviates from this line by more than 2 percent of the maximum concentration tested.
      <IP_ADDRESS> Option 1: The various O3 concentrations required in steps <IP_ADDRESS> and <IP_ADDRESS> may be obtained by dilution of the O3 concentration generated in steps <IP_ADDRESS> and <IP_ADDRESS>. With this option, accurate flow measurements are required. The dynamic calibration system may be modified as shown in Figure 3 to allow for dilution air to be metered in downstream of the O3 generator. A mixing chamber between the O3 generator and the output manifold is also required. The flow rate through the O3 generator (Fo) and the dilution air flow rate (FD) are measured with a flow or volume standard that is traceable to a NIST flow or volume calibration standard. Each O3 concentration generated by dilution is calculated from:
      [O3]'OUT=[O3]OUT FOFO+FD					(5)
      where:
      [O3]′OUT = diluted O3 concentration, ppm
      FO = flow rate through the O3 generator, liter/min
      FD = diluent air flow rate, liter/min
      Note: Additional information on calibration and pollutant standards is provided in Section 12 of Reference 14.
      5.0 Frequency of Calibration.
      5.1 The frequency of calibration, as well as the number of points necessary to establish the calibration curve, and the frequency of other performance checking will vary by analyzer; however, the minimum frequency, acceptance criteria, and subsequent actions are specified in Appendix D of Reference 14: Measurement Quality Objectives and Validation Templates. The user's quality control program shall provide guidelines for initial establishment of these variables and for subsequent alteration as operational experience is accumulated. Manufacturers of analyzers should include in their instruction/operation manuals information and guidance as to these variables and on other matters of operation, calibration, routine maintenance, and quality control.
6.0 References.
      1. E.C.Y. Inn and Y. Tanaka, "Absorption coefficient of Ozone in the Ultraviolet and Visible Regions", J. Opt. Soc. Am., 43, 870 (1953).
      2. A. G. Hearn, "Absorption of Ozone in the Ultraviolet and Visible Regions of the Spectrum", Proc. Phys. Soc. (London), 78, 932 (1961).
      3. W. B. DeMore and O. Raper, "Hartley Band Extinction Coefficients of Ozone in the Gas Phase and in Liquid Nitrogen, Carbon Monoxide, and Argon", J. Phys. Chem., 68, 412 (1964).
      4. M. Griggs, "Absorption Coefficients of Ozone in the Ultraviolet and Visible Regions", J. Chem. Phys., 49, 857 (1968).
      5. K. H. Becker, U. Schurath, and H. Seitz, "Ozone Olefin Reactions in the Gas Phase. 1. Rate Constants and Activation Energies", Int'l Jour. of Chem. Kinetics, VI, 725 (1974).
      6. M. A. A. Clyne and J. A. Coxom, "Kinetic Studies of Oxy-halogen Radical Systems", Proc. Roy. Soc., A303, 207 (1968).
      7. J. W. Simons, R. J. Paur, H. A. Webster, and E. J. Bair, "Ozone Ultraviolet Photolysis. VI. The Ultraviolet Spectrum", J. Chem. Phys., 59, 1203 (1973).
      8. Ollison, W.M.; Crow, W.; Spicer, C.W. "Field testing of new-technology ambient air ozone monitors." J. Air Waste Manage. Assoc., 63 (7), 855-863 (2013).
      9. Parrish, D.D.; Fehsenfeld, F.C. "Methods for gas-phase measurements of ozone, ozone precursors and aerosol precursors." Atmos. Environ., 34 (12-14), 1921-1957(2000).
      10. Ridley, B.A.; Grahek, F.E.; Walega, J.G. "A small, high-sensitivity, medium-response ozone detector suitable for measurements from light aircraft." J. Atmos. Oceanic Technol., 9 (2), 142-148(1992).
      11. Boylan, P., Helmig, D., and Park, J.H. "Characterization and mitigation of water vapor effects in the measurement of ozone by chemiluminescence with nitric oxide." Atmos. Meas. Tech. 7, 1231-1244 (2014).
      12. Transfer Standards for Calibration of Ambient Air Monitoring Analyzers for Ozone, EPA publication number EPA-454/B-13-004, October 2013. EPA, Office of Air Quality Planning and Standards, Research Triangle Park, NC 27711. [Available at www.epa.gov/ttnamti1/files/ambient/qaqc/OzoneTransferStandardGuidance.pdf.]
      13. Technical Assistance Document for the Calibration of Ambient Ozone Monitors, EPA publication number EPA-600/4-79-057, September, 1979. [Available at www.epa.gov/ttnamti1/files/ambient/criteria/4-79-057.pdf.]
      14. QA Handbook for Air Pollution Measurement Systems -- Volume II. Ambient Air Quality Monitoring Program. EPA-454/B-13-003, May 2013. [Available at http://www.epa.gov/ttnamti1/files/ambient/pm25/qa/QA-Handbook-Vol-II.pdf.]

Figure 1. Gas-phase chemiluminescence analyzer schematic diagram, where PMT means photomultiplier tube.

Figure 2. Schematic diagram of a typical UV photometric calibration system.

Figure 3. Schematic diagram of a typical UV photometric calibration system (Option 1).

6. Add appendix U to Part 50 under subchapter C to read as follows:
Appendix U to Part 50--Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone

                                  1. General
(a) This appendix explains the data handling conventions and computations necessary for determining whether the primary and secondary national ambient air quality standards (NAAQS) for ozone (O3) specified in § 50.19 are met at an ambient O3 air quality monitoring site. Data reporting, data handling, and computation procedures to be used in making comparisons between reported O3 concentrations and the levels of the O3 NAAQS are specified in the following sections.
(b) Whether to exclude or retain the data affected by exceptional events is determined by the requirements under §§ 50.1, 50.14 and 51.930.
(c) The terms used in this appendix are defined as follows:
8-hour average refers to the moving average of eight consecutive hourly O3 concentrations measured at a site, as explained in section 3 of this appendix.
Annual fourth-highest daily maximum refers to the fourth highest value measured at a site during a year.
Collocated monitors refers to the instance of two or more O3 monitors operating at the same physical location.
Daily maximum 8-hour average O3 concentration refers to the maximum calculated 8-hour average value measured at a site on a particular day, as explained in section 3 of this appendix.
Design value refers to the metric (i.e., statistic) that is used to compare ambient O3 concentration data measured at a site to the NAAQS in order to determine compliance, as explained in section 4 of this appendix.
Minimum data completeness requirements refer to the amount of data that a site is required to collect in order to make a valid determination that the site is meeting the NAAQS.
Monitor refers to a physical instrument used to measure ambient O3 concentrations.
O3 monitoring season refers to the span of time within a year when individual states are required to measure ambient O3 concentrations, as listed in Appendix D to part 58 of this chapter.
Site refers to an ambient O3 air quality monitoring site.
Site data record refers to the set of hourly O3 concentration data collected at a site for use in comparisons with the NAAQS.
Year refers to calendar year.
2. Selection of Data for use in Comparisons with the Primary and Secondary Ozone NAAQS
(a) All valid hourly O3 concentration data collected using a federal reference method specified in Appendix D to this part, or an equivalent method designated in accordance with part 53 of this chapter, meeting all applicable requirements in part 58 of this chapter, and submitted to EPA's Air Quality System (AQS) database or otherwise available to EPA, shall be used in design value calculations.
(b) All design value calculations shall be implemented on a site-level basis. If data are reported to EPA from collocated monitors, those data shall be combined into a single site data record as follows:
      (i) The monitoring agency shall designate one monitor as the primary monitor for the site.
      (ii) Hourly O3 concentration data from a secondary monitor shall be substituted into the site data record whenever a valid hourly O3 concentration is not obtained from the primary monitor. In the event that hourly O3 concentration data are available for more than one secondary monitor, the hourly concentration values from the secondary monitors shall be averaged and substituted into the site data record.
(c) In certain circumstances, including but not limited to site closures or relocations, data from two nearby sites may be combined into a single site data record for the purpose of calculating a valid design value. The appropriate Regional Administrator may approve such combinations after taking into consideration factors such as distance between sites, spatial and temporal patterns in air quality, local emissions and meteorology, jurisdictional boundaries, and terrain features.
               3. Data Reporting and Data Handling Conventions
(a) Hourly average O3 concentrations shall be reported in parts per million (ppm) to the third decimal place, with additional digits to the right of the third decimal place truncated. Each hour shall be identified using local standard time (LST).
(b) Moving 8-hour averages shall be computed from the hourly O3 concentration data for each hour of the year and shall be stored in the first, or start, hour of the 8-hour period. An 8-hour average shall be considered valid if at least 6 of the hourly concentrations for the 8-hour period are available. In the event that only 6 or 7 hourly concentrations are available, the 8-hour average shall be computed on the basis of the hours available, using 6 or 7, respectively, as the divisor. In addition, in the event that 5 or fewer hourly concentrations are available, the 8-hour average shall be considered valid if, after substituting zero for the missing hourly concentrations, the resulting 8-hour average is greater than the level of the NAAQS, or equivalently, if the sum of the available hourly concentrations is greater than 0.567 ppm. The 8-hour averages shall be reported to three decimal places, with additional digits to the right of the third decimal place truncated. Hourly O3 concentrations that have been approved under §50.14 as having been affected by exceptional events shall be counted as missing or unavailable in the calculation of 8-hour averages.
(c) The daily maximum 8-hour average O3 concentration for a given day is the highest of the 17 consecutive 8-hour averages beginning with the 8-hour period from 7:00 a.m. to 3:00 p.m. and ending with the 8-hour period from 11:00 p.m. to 7:00 a.m. the following day (i.e., the 8-hour averages for 7:00 a.m. to 11:00 p.m.). Daily maximum 8-hour average O3 concentrations shall be determined for each day with ambient O3 monitoring data, including days outside the O3 monitoring season if those data are available.
(d) A daily maximum 8-hour average O3 concentration shall be considered valid if valid 8-hour averages are available for at least 13 of the 17 consecutive 8-hour periods starting from 7:00 a.m. to 11:00 p.m. In addition, in the event that fewer than 13 valid 8-hour averages are available, a daily maximum 8-hour average O3 concentration shall also be considered valid if it is greater than the level of the NAAQS. Hourly O3 concentrations that have been approved under § 50.14 as having been affected by exceptional events shall be included when determining whether these criteria have been met.
(e) The primary and secondary O3 design value statistic is the annual fourth-highest daily maximum 8-hour O3 concentration, averaged over three years, expressed in ppm. The fourth-highest daily maximum 8-hour O3 concentration for each year shall be determined based only on days meeting the validity criteria in 3(d). The 3-year average shall be computed using the three most recent, consecutive years of ambient O3 monitoring data. Design values shall be reported in ppm to three decimal places, with additional digits to the right of the third decimal place truncated.
          4. Comparisons with the Primary and Secondary Ozone NAAQS
(a) The primary and secondary national ambient air quality standards for O3 are met at an ambient air quality monitoring site when the 3-year average of the annual fourth-highest daily maximum 8-hour average O3 concentration (i.e., the design value) is less than or equal to 0.070 ppm.
(b) A design value greater than the level of the NAAQS is always considered to be valid. A design value less than or equal to the level of the NAAQS must meet minimum data completeness requirements in order to be considered valid. These requirements are met for a 3-year period at a site if valid daily maximum 8-hour average O3 concentrations are available for at least 90% of the days within the O3 monitoring season, on average, for the 3-year period, with a minimum of at least 75% of the days within the O3 monitoring season in any one year.
(c) When computing whether the minimum data completeness requirements have been met, meteorological or ambient data may be sufficient to demonstrate that meteorological conditions on missing days were not conducive to concentrations above the level of the NAAQS. Missing days assumed less than the level of the NAAQS are counted for the purpose of meeting the minimum data completeness requirements, subject to the approval of the appropriate Regional Administrator.
(d) Comparisons with the primary and secondary O3 NAAQS are demonstrated by examples 1 and 2 as follows:
          Example 1: Site Meeting the Primary and Secondary O3 NAAQS
                                     Year
      Percent valid days within O3 monitoring season (Data completeness)
                     1st highest daily max 8-hour O3 (ppm)
                     2nd highest daily max 8-hour O3 (ppm)
                     3rd highest daily max 8-hour O3 (ppm)
                     4th highest daily max 8-hour O3 (ppm)
                     5th highest daily max 8-hour O3 (ppm)
                                     2014
                                      100
                                     0.082
                                     0.080
                                     0.075
                                     0.069
                                     0.068
                                     2015
                                      96
                                     0.074
                                     0.073
                                     0.065
                                     0.062
                                     0.060
                                     2016
                                      98
                                     0.070
                                     0.069
                                     0.067
                                     0.066
                                     0.060
                                    Average
                                      98

                                     0.065

As shown in Example 1, this site meets the primary and secondary O3 NAAQS because the 3-year average of the annual fourth-highest daily maximum 8-hour average O3 concentrations (i.e., 0.065666 ppm, truncated to 0.065 ppm) is less than or equal to 0.070 ppm. The minimum data completeness requirements are also met (i.e., design value is considered valid) because the average percent of days within the O3 monitoring season with valid ambient monitoring data is greater than 90%, and no single year has less than 75% data completeness.
    Example 2: Site Failing to Meet the Primary and Secondary O3 O3 NAAQS
                                     Year
      Percent valid days within O3 monitoring season (Data completeness)
                     1st highest daily max 8-hour O3 (ppm)
                     2nd highest daily max 8-hour O3 (ppm)
                     3rd highest daily max 8-hour O3 (ppm)
                     4th highest daily max 8-hour O3 (ppm)
                     5th highest daily max 8-hour O3 (ppm)
                                     2014
                                      96
                                     0.085
                                     0.080
                                     0.079
                                     0.074
                                     0.072
                                     2015
                                      74
                                     0.084
                                     0.083
                                     0.072
                                     0.071
                                     0.068
                                     2016
                                      98
                                     0.083
                                     0.081
                                     0.081
                                     0.075
                                     0.074
                                    Average
                                      89

                                     0.073

As shown in Example 2, this site fails to meet the primary and secondary O3 NAAQS because the 3-year average of the annual fourth-highest daily maximum 8-hour average O3 concentrations (i.e., 0.073333 ppm, truncated to 0.073 ppm) is greater than 0.070 ppm, even though the annual data completeness is less than 75% in one year and the 3-year average data completeness is less than 90% (i.e., design value would not otherwise be considered valid).
PART 51 -- REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS
7. The authority citation for part 51 continues to read as follows:
      Authority: 23 U.S.C. 101; 42 U.S.C. 7401-7671q.
Subpart I -  -- Review of New Sources and Modifications
8. Amend § 51.166 by adding paragraph (i)(11) to read as follows:
§ 51.166 Prevention of significant deterioration of air quality.
* * * * *
(i) * * *
(11) The plan may provide that the requirements of paragraph (k)(1) of this section shall not apply to a stationary source or modification with respect to the national ambient air quality standards for ozone in effect on [Insert date 60 days after date of publication in the Federal Register] if:
      (i) The reviewing authority has determined a permit application subject to this section to be complete on or before [Insert signature date of this final rule]. Instead, the requirements in paragraph (k)(1) of this section shall apply with respect to the national ambient air quality standards for ozone in effect at the time the reviewing authority determined the permit application to be complete; or