Enclosure

EPA Response to Petition for Reconsid eration from Devon Energy Corporation

By letter dated July 20, 2012, Sidley Austin LLP, on behalf of Devon Energy Corporation, petitioned the EPA to reconsider the final area designation for Wi se County in the Dallas-Fort Worth (DFW) ozone nonattainment area and to stay the effectiven ess of the designation for Wise County, pending reconsideration. For the reasons discussed below, th e EPA is denying the Petiti on. Therefore, the EPA is also denying the request for stay. For the sake of clarity, we have organized most of this response according to the structure of the July 20, 2012, petition.

I. Concern About Treatment of the Oil and Gas Industry

Issue: The Petitioner claims that the designation of Wise County shoul d be reconsidered because of a perceived bias by Dr. Armendariz against the oil and ga s industry that may have played an undue role in the designation process.

Response: The EPA’s final designa tion decision for the DFW area was based on the EPA’s evaluation of the data and technical information, extensive and thoughtful consideration of input from TCEQ and other interested parties. The EPA’ s national Office of Air and Radia tion works closely with technical staff in the EPA’s regional offices to ensure that d ecisions are based on the fact ual record and consistent across the country. As demonstrated in the T echnical Support Document (TSD) accompanying the EPA’s intended designations issued in December, 2011 and the TSD accompanying the final designation on April 30, 2012, the EPA performed a thorough asse ssment of information relevant to five designations-related factors in determining which ar eas should be included as part of the DFW nonattainment area. The final decision was made by Administrator Lisa Jackson based on the record

before the EPA. We further note that there are other Texas counties where oil and gas production and activity occur that were initially considered for incl usion into a nonattainment ar ea, but were ultimately not included. For example Hood County, Texas a nd Matagorda County, Texas were considered and proposed for inclusion in their resp ective areas. However, following a review of comments from Texas and from public commenters and upon further eval uation of all available data relevant to their contribution to ozone violations, we determined t hose counties should not be included as part of a

nonattainment area. Our record details those decisions.

II. Modeling Analysis

A. Source Apportionment Modeling

Issue: The Petitioner claims that the EPA’s re-analysis of TCEQ’s Source Apportionment Modeling (SAM) is new information and is not a logical outgrowth of the proposal. It was therefore impracticable for Petitioner to raise obj ections to the modeling work and the standard for “contribution” during the publ ic comment period. Such re-ana lysis should therefore undergo public review before final rulemaking.

Response: While we agree that our analysis of the state’s SAM mode ling was not available for comment at the time of proposal, we do not believe this issue warrants reconsideration. Fi rst, in response to the EPA’s 120-day letter notifying it of the intended designations, the state submitted, among other things,the SAM data and results. Our evaluation of the SAM was in response to such submittal and was consistent with the process esta blished by Congress in section 107(d) of the Act. For initial area designations for a new or revised NAAQS, section 107(d)(1) of the CAA sets forth a detailed and specific process between the EPA and the states. This provision provides: (i) th at Governors of states

make the initial recommendations to the EPA for de signations and boundaries; and (ii) that the EPA provide the states with 120 days notice of any intended modifications to the state recommendation prior to finalizing the designation. The 120- day notification process is for the purpose of providing “such State with an opportunity to demonstrate why any proposed modification is inappropriate.” The CAA does not expressly provide a role for any other en tity and, moreover, expressly waives the notice and public comment process of the Administrative Procedur e Act for initial designati ons for new or revised NAAQS. See CAA section 107(d)(2)(B). Although no public comment period is required, the EPA opted to provide such a comment period for the ozone designations for the 2008 ozone NAAQS. We appropriately followed the process specifically c ontemplated by the Act. The EPA’s response to TCEQ’s SAM is detailed in the EPA’s final TSD. See Final DFW TSD at 15-20.

Second, and as a general matter, agencies are not required to provide an additional opportunity for public comment on material supporting a final rule, su ch as responses to comments or on information supporting a response to a comment. Such an appr oach would result in an unworkable endless rulemaking process. See Catawba , 571 F.3d at 50-51 (In rejecting a claim by New York that it should have been allowed additional input into the EPA’s d ecision to rely on a different monitor for evaluating contribution for the final designation th an it did for the intended designa tion the court noted that such an ongoing exchange with the states is inconsistent with the CAA and that “Congress imposed deadlines on the EPA and thus clearly envi sioned an end to the desi gnation process.”) See also International

Fabricare Institute v. EPA , 972 F.2d 384, 399 (D.C. Cir. 1992) (notice and comment is not intended to result in “interminable back-and-forth”) and Community Nutrition Institute v. Block , 749 F.2d 50, 58 (D.C. Cir. 1984) (agency is not requ ired to provide additional opportuni ty to comment on its response to comments).

Issue: The Petitioner claims that as part of the fina l rule the EPA used a new 1% standard in analyzing the source apportionment modeling (SAM), and it did not offer a rational basis for its use or opportunity for comment. Furthermore, the Peti tion claims that the EPA’s use of the 1% standard was inconsistent with other Regions and specifically raises concerns with the EPA’s review and conclusions of SAM analysis for three countie s in the Chicago area.

Response: The EPA considered source apportionmen t modeling (SAM) in its decision making only in areas where it was provided by states or others during the public pr ocess. Since the SAM was provided during the comment period, as discussed above, our ev aluation consequently could not be available for public comment.

SAM results were available for the EPA considerati on in the designation proce ss for only three areas, Dallas, Houston and Chicago, because those were th e only areas where it was developed and submitted to the EPA by states or other enti ties. The EPA does not have specifi c guidance on how to evaluate the impact of emissions from a county on a nearby vi olating monitor in the context of a designation decision. Moreover, in the few instances where SAM was submitted for our consideration, the form and type of the information varied between areas. Th e EPA evaluated each submission of SAM on a caseby-case basis, carefully assessing a number of issues including how the modeling was conducted, model performance, and available data from the analysis in order to derive appropri ate conclusions from the

results.For the SAM submitted for Dallas and Houston, we cons idered other recent modeling work as a guide. Our basis for identifying days w ith a non-trivial impacts is discussed on page 17 of the TSD where we explained, “Often in attainment demonstration modeli ng, controlling of sources is evaluated and results in only a few tenths of a ppb change, therefore we us ed a 1% of the standard cut point for the days

where we would consider Hood or Wise County’s emissions to be si gnificant.” We also note that modeling from TCEQ in a 2007 8-hour Ozone Attainment Demonstration for DFW included multiple analyses of individual control strategies and the resultant impacts on monitors in DFW area, where Texas had chosen controls that provided change s of a few tenths of a part per billion (ppb). 1 In addition,

we note that the EPA concluded in the recent Cross St ate Air Pollution Rule, that a “one percent of the NAAQS” impact result in the source apportionment modeling was appropriate to determine if a state’s emissions significantly impacted a downwind state’s nonattainment or maintenance area. 2 Thus we believe it was reasonable to examine the frequency of a modeled impact of 0.75 ppb, or one percent of the 2008 ozone standard, as a metric to id entify days with a nontrivial impact. 3

In addition, the number of days exce eding the one percent (0.75 ppb) cut point is only one of the metrics

evaluated from the SAM results. In the DFW Final TSD and in supporting files, we discussed all of the metrics used in our assessment of the SAM results, and the unique factors that we weighed in our analysis of SAM results for DFW. Using the deta iled daily information available to the EPA for analyzing SAM for the DFW and Houston areas designations, we evaluated the average impact, maximum impact, as well as the number of mo deled days exceeding 0.075 and 0.070 parts per million (ppm) where the Wise County impact was above 0.75 ppb. These other model output metrics also help explain the impact of Wise County. For example, on some specific modeled days the impact of Wise County was much larger than 0.5 ppb and as much as 5 ppb at the Eagle Mountain Lake Monitor, which

is one of the monitors in DFW that sets the DV for the DFW nonattainment area. 4 Also, it is important to

remember that the SAM results were only one type of information that we considered in our five factor analysis that resulted in our de termination that Wise County contri butes to nonattainment in the DFW

area.

Our decision to use 1% of the NAAQS (0.75 ppb) as a cut point to identify days with a non-trivial impact is supported by our record, an d a count of such days is only one of the metrics we evaluated from the SAM results. As stated in our TSD, the 2008 Emi ssions Inventory for Wise County shows that Wise County’s nitrogen oxide emissions of 11,911 tons per year (tpy) are th e 6th highest of the 19-county DFW Combined Statistical Area (C SA) and the County’s volatile organic compound emissions of 17,609 tpy are the fourth highest of the 19 counties. See TSD pages 6-7. The TSD demonstrates that there are six ozone monitors violating the standard in the two counties adj acent to Wise County (TSD Figure 1, page 3) and notes that Wise County is less than 1⁄2 mile from a viola ting monitor with a design value of 0.085 ppm (TSD 2008 to 2010 data, pages 5 and 23). We also evaluated meteorological transport patterns during exceedances using NOAA’s HYSPLIT model. These patterns indicate that emissions from Wise County are tran sported to the DFW ozone monitors violating the standard based on 2008-2010 data, and we conclude th at the Wise County emissions are large enough that they can

contribute to ozone exceedances on ce rtain days and many of these days are the days that set the DV at the highest monitors in DFW. See TSD pages 14-17, 19, 20, and 23.

1 See the sensitivity runs in TCEQ’s 2007 DFW 1997 8-hour ozone Attainment Demonstration SIP - APPENDIX D: DFW Future Case (2009) Sensitivity Tests.

2 See Cross State Air Pollution Rule and the Technical Support Document for the rule(Docket ID: EPA-HQ-OAR-2009-0491 at www.regulations.gov)

3 TSD page 17, TCEQ’s 2007 DFW 1997 8-hour ozone Attainment Demonstration SIP – Appendix D: DFW Future Case (2009) Sensitivity Tests.

4 TSD page 20Finally, our evaluation of SAM was not inconsistent with actions ta ken by other Regional offices. Again, our record supports our decision on this issue. We considered SAM for the Houston area in the same way we considered it for Dallas because th e SAM submitted for both areas was similar in how it was performed and the type of information provide d. The only other area for which the EPA had SAM results was for the Chicago area. The SAM submitted for the Chicago area was sufficiently different that direct comparisons to the DFW area analysis are not generally appropriate. In the Chicago area SAM, the EPA was provided the average modeled impact leve ls on estimated exceedances for an entire ozone season. Emphasis on the average modeled impact is mo re appropriate when a full ozone season of model

results is available. A full season of modeling results was not availa ble for the DFW area. Indiana had provided SAM that evaluated the im pact of three Indiana counties on a monitor in the greater Chicago area. The reported impacts from two Counties (Lak e and Porter) were about 2 ppb and 4 ppb. The SAM result for the third Indiana County (Jasper) indicated less than 0.5 ppb im pact. In evaluating this result, the EPA was aware that the modeling did not reflect emissions reductions that had been achieved at a large power plant in Jasper Count y, reducing Jasper County’s total NOx emissions by more than 50%. 5
Based on the analysis of all the f actors, including the SAM and addi tional emission reductions, the EPA decided to include Lake and Porter Counties, and not to include Jasper C ounty, Indiana within the

nonattainment area. As with the contribution level evaluated for Wise County, the contribution levels discussed in the Region 5 Chicago Fi nal TSD do not represent a bright line criterion for inclusion or exclusion of a county. Moreover, the inclusion of two counties with an average contribution of 2 and 4 ppb and exclusion of a county with less than 0.5 ppb in the Chicago area is not inconsistent with inclusion of Wise County, which is based in pa rt on a count of days with greater than 0.75 ppb contribution in the Dallas area. As noted above, however, for both the Chicago and Dallas areas, SAM results are simply one element of one of the five f actors the EPA considered in determining whether to include counties as part of the designated nonattainment area.

Issue: The Petitioner claims that the EPA’s analys is of the SAM focused on exceedances of the NAAQS

rather than violations and as such is flawed a nd inconsistent with past practice and guidance. The

Petitioner also indicated that th e EPA’s methodology is inconsistent with past practices because it

focused on absolute rather than relative results. Th ey indicated that for comparison that TCEQ staff had analyzed the SAM in a relative sense and scaled to the observed design values with calculated DVs at each monitoring site. The Petitioner indicated that the EPA’s guidance is to use the model in a relative sense, rather than absolute as was done in CSAPR. The Petitioner indicated that TCEQ had concluded that Wise County only contributed 0.41 ppb and 0.008 ppb to the Eagle Mountain Lake and Keller monitors 2012 future year DVs, and that this is be low any threshold used by the EPA, including the 0.75 ppb in the Final DFW TSD and the threshold for Ja sper County in the Chicago area. The Petitioner

concluded that the EPA was inconsistent with its own guidance and past pract ice in CSAPR, and that TCEQ was in compliance with both.

Response: While our analysis of th e state’s SAM modeling was not available for comment at the time of proposal, we do not believe this issu e warrants reconsideratio n. In addition, we disagree that our analysis

was flawed or inconsistent with our past practice and guidance, and our decision is supported by our

record as stated below.

First, in analyzing possible contributions from emissions in surrounding coun ties using the SAM tool, the EPA only evaluated and considered the amount of modeled impact from Wise County emissions on

5 Region 5 TSD, Original 2008 NOx emissions quantified as 19,788 tons/year and value was footnoted as “... updated emissions data were provided for Jasper County showing 2011 NOx emission levels of 9,791 tons.”monitors that were violating the 2008 ozone standard according to the 2008-2010 data. 6 We focused our assessment on monitors violating th e standard and, in doing so, examin ed contributions on days when there were exceedances at those violating monitors. As a factual matter, it is not possible to separate

“actual violations” from the “exceedances” that result in the violation. Based on the form of the ozone standard, an area is determined to be violating the standard if the th ree consecutive year average of the annual fourth highest daily maximum 8-hour average am bient air quality ozone concentration is greater than the standard (0.075 ppm). Ther efore, all daily maximum 8-hour av erages that exceed 0.075 ppm at a violating monitor (i.e., “exceedances”) are releva nt for purposes of determining whether emissions

contribute to a violation at that monitor. Accordingly, we restri cted our review of available modeling impact results to days with modeled exceedances at violating monitors. 7 As part of this analysis, we evaluated the monitoring data durin g the episode modeled to determin e if exceedances had actually occurred at the monitor on that specific day.

The use of modeled exceedance days for estimating ozone using photochemical gr id models is a longestablished practice for modeled at tainment demonstrations. This approach is recommended by the EPA in “Guidance on the Use of Models and Other Analyses for Demonstrating Attainment of Air Quality Goals for Ozone, PM 2.5 , and Regional Haze” (EPA-454/B-07-002) , and used by the EPA to support

Federal rules such as the Cross-State Air Pollution Rule.

The EPA does not have specific guidance on how to ev aluate the impact of emissions from one county on a nearby violating monitor using SAM. Our evalua tion of the SAM results provided by TCEQ for the DFW area and by LADCO for the Chicago area diffe red according to the nature of the modeling conducted and the results provided to us. In the Chicago case, we eval uated the average impact over the entire ozone season; day-specific impact informa tion was not provided. In evaluating the TCEQ SAM results, we felt it was appropriate to consider day-specific imp acts because, as discussed above, individual exceedance days contribute to the calcul ation of the area’s DV’s. Varying meteorological

conditions can lead to the indivi dual exceedances and as a result can lead to a violation. As the SAM results show, some days Wise County’s impact is much greater than others. This information is masked when only average impacts are consider ed. In addition, as discussed later, we place more weight on dayspecific impacts as compared to average impacts b ecause the Texas modeling did not cover a complete

ozone season.

Since the EPA does not have a specific guidance docu ment on how to evaluate the impact of emissions from one county on a nearby monitor using SAM, the Petitioner’s concern that the EPA did not follow its own guidance by using the model in an absolute sense rather than a relative sense is misplaced. Consideration of day-specific impacts does not as easily lend itself to usin g the model in a relative sense. If, however, the EPA had used a relative reduction factor approach to estimating the day-specific impacts, we believe the modeled impacts from Wise County would have been larger because of the

model’s underestimation bias.

We note that the EPA’s current modeling guidance is directed towards th e overall attainment demonstration test and not towards SAM analysis, but in the past we have evalua ted day-specific results provided in previous DFW atta inment demonstration modeling. 8 The Petitioner is incorrect that TCEQ

did not include absolute modeled values in their comments. TCEQ comments included using the model

6 Final TSD, pages 15-20.

7 Id., pages 15-20.

8 TCEQ 2007 Attainment Demonstration for DFW 1997 8-hour ozone included day specific modeling calculations.in both the relative sense and in the absolute sense. In fact, TCEQ had six different figures with the absolute values and only one figure with relative values. 9

Petitioner points to the TCEQ’s conclusions th at Wise County only contributed 0.41 ppb and 0.008 ppb to two monitors’ 2012 future year DVs, which are below a threshold of 0.75 ppb. Therefore, Petitioner claims Wise County’s contribution is not significant. The EPA notes that this is comparing data in an ‘apples to oranges’ manner. The 0.41 ppb and 0.008 ppb are average values of contribution to any exceedance of 75 ppb predicted at the Eagle Mounta in Lake and Keller monitors, respectively, in 2012 for the episode days modeled. By contrast, the 0.7 5 ppb value was a day-specific cut point to identify days with non-trivial impacts. However, there we re specific modeled days on which the contribution level from Wise County at the Eagle Mountain monito r was predicted to be above 0.75 ppb. As noted in our TSD, we were concerned that the underestimati on bias in the model was underestimating the number of days that exceedances are predic ted compared to the monitored values in 2006. The effects of this underestimation bias is that the 0.41 ppb average impact value is based on fewer days than actually had measured exceedances. In addition, since the modeling was not for a full season it does not capture all of the meteorological conditions that le ad to high ozone in the DFW area. As a result, average values for ozone impacts based on less than a full year of modeling and that are based on a model that

underestimates ozone levels can be misleading and underestimate the im pact of emissions from a source area. Therefore, our analysis placed greater weig ht on modeled daily contri butions than on episode average values, as discussed on pages 15-20 of the Final DFW TSD. As discussed above, the EPA does not have LADCO modeling for Jasper County that is reflective of th e large NOx reductions that have occurred since the modeling was performed, but revi sed modeling would be expected to show a much lower ozone season average contribu tion than 0.41 ppb. Again, this number is not directly comparable to the 0.75 ppb cut point used in the EPA’s evaluati on of the DFW area to identify individual modeled days with non-trivial impacts.

Issue: The Petitioner claims that the EPA did not recognize that the modeling assumed significantly higher annual VOC emissions than has been more recently reported by TCEQ data. Specifically, the

more recent data indicate VOC emissions are 25% lo wer for Wise County than the levels used in the

model. The Petition asserts that the EPA should have ut ilized the newer data in its analysis of modeling.

Response: The Petitioner did pr ovide comments on this issue dur ing the comment period. The EPA responded to those comments, as referenced below. Th erefore, reconsideration is not appropriate here. In addition, TCEQ provided updated 2008 emissions i nventory data in October 2011. On February 29, 2012, Texas submitted source apportionment modeling (S AM) results and indicated that the modeling was not conducted using the new lower VOC emissi on estimates that TCEQ had submitted to the EPA

in October 2011. See page 10 of TCEQ letter.

Although we could not rerun the m odel using the emissions information submitted by TCEQ in October 2011, we did consider the emissions information, in cluding how that inform ation might affect the

modeled results. As noted in our Final TSD and RTC, we revised the Wise County VOC emissions inventory based on comments we r eceived from the State of Texas. 10 We also indicated in the RTC and other supporting materials that DFW is a NOx li mited area and VOC reductions have not shown significant benefit in reducing ozone levels in past modeling conducte d by TCEQ. The Petitioner seems to recognize this point when they note: “TCEQ ha s demonstrated through co mplex modeling that it is NOx, not man-made VOC that drives ozone forma tion in the DFW region.” (See Devon Comment letter

9 Page11-14 of TCEQ attachment to Governor Perry’s comment letter dated February 29, 2012 included Figures 7-11 that had maximum, average and hourly time series absolute values and only Table 3 which had the relative value.

10 Final TSD, page 6; RTC pages 52-56.February 3, 2012, page 4). Furthermor e, in the record we recognized that the VOCs that are potentially overestimated are from oil and gas operations and that these VOC emissions “are relatively nonreactive,” i.e., they are less like ly to result in ozone formation th an VOCs that are more reactive. Accordingly, we did consider the potential impact of the new reported VOC emission levels on our interpretation of the SAM results for Wise, Co unty and concluded that the impacts would be negligible. 11

B. HYPSLIT

Issue: The Petitioner claims that Region 6 errone ously relied on the HYSPLIT model because other Regional Offices relied on prevailing wind direction. Furthermore, they assert that the EPA erroneously relied on the HYSPLIT modeling to include Wise Count y as part of the designa ted nonattainment area because the modeling shows that Wi se County is not contributing to violations of the NAAQS because HYSPLIT provides no information rega rding the formation or transport of ozone and shows that in only the rarest of instances, wind from Wise Count y reaches a monitor exceeding the NAAQS. Finally, Petitioner claims there were only two days in wh ich the HYSPLIT modeling indicates that wind passing over Wise County may have reached an exceeding/violating monitor.

Response: Petitioner raised the HYSPLIT issue du ring the comment period and the EPA adequately responded to those comments. See RTC pages 59, 60. Ther efore, reconsideration is not appropriate. Our record fully supports our decision. The EPA’s record supports that HYSPLIT is a useful tool for determining areas where air origin ates or passes through on the way to a monitored ozone exceedance. We disagree that our evaluation of HYSPLIT mode ling to inform our nonattainment area designation

decisions was incorrect or inconsistent. As we stat ed in the RTC, “[i]n terms of identifying potential local and regional source-receptor patterns, HYPLIT wi nd trajectory or other modeling based tools are excellent tools for determining the frequencies for which areas pot entially contribut e to high ozone levels and are preferred over more basic assessmen ts of wind speed and dir ection at a given point locations (e.g., wind roses, or pollution roses). The ba sic assessments, such as wind roses, are potentially misleading in cases where wind speeds are li ght and the wind dire ction is variable....” 12 The light and variable meteorological regime is one of the classic meteorological type s that results in high ozone in the

DFW area. “While it is true that EPA was unable to use HYSPLIT modeling to inform our decisions for all areas, we believe that it is a valuable tool a nd should not be disregarded where the information is available, even if the information is not available in all areas.” See RTC page 59.

We note that each designation decision is made on a case-by-case basis after weighing information relevant to the five factors (and any other relevant information) as they apply based on the unique

11 Final TSD, pages 6-8; Houston Final TSD, pages 5-7; RTC pages 52-56, including “...the VOC emissions resulting from oil & gas production activities ar e relatively nonreactive in the photochemical generation of ground-level ozone and that additionally the DFW area is NOx-limited such that VOC emissions in general do not contribute as much as NOx emissions to the generation of ground-level ozone.” And “EPA has since reviewed the updated emissions data reported by the TCEQ and notes that the revised numbers do not affect the ranking of the counties for VOC emissions. EPA’s analysis indicates that even with the reduced 2009 VOC emissions data, the emissions from Wise County still contribute to measured violations of the 2008 ozone NAAQS at monitors in neighboring counties. In making our final decision, we considered the reduced emissions and the reduction in drilling activity since 2009.” Th e Governor Perry’s comment letter dated February 29, 2012, pages 17-21, also referred to other TCEQ documents that further support that DFW area is a NOx limited regime and changes to VOC levels do not result in much impact in ozon e levels: TCEQ 2011 DFW 1997 8-hour Ozone Attainment Demonstration SIP – “APPENDIX E: Protocol for the Eight-Hour Ozone Modeling of the Dallas-Fort Worth Area,” and “APPENDIX D: Conceptual Model For The DFW Attainment Demonstration SIP Revision For The 1997 Eight-Hour Ozone

Standard.” 12 See page 59 of the RTC.situation of each area. The HYSPLIT modeling was considered as one component of information for one of the five factors, and was not the sole c onsideration in making our designation decisions.

We conducted HYSPLIT analysis for several monito rs in DFW for purposes of both the Preliminary TSD (December 2011) and the Final TSD (April 2012). In the Final TSD, we noted that “[t]he HYSPLIT model yields an estimate of the path an air mass has traveled before reaching a monitor at a specific location and time. Specifi cally, the model provides the cente rline of the probable path. By knowing where an air mass has traveled before reach ing a monitor where an exceedance has occurred, one can consider what potential areas and emission s ources could have contribu ted to the exceedance.” In the Final TSD at page 14, we stated, “[w]e focu sed on the Keller and Eagle Mountain Lake monitors in Tarrant County and the Parker County monitor becau se the Keller and Eagle Mountain Lake monitors have recorded some of the highest ozone levels in the region, and inclusion of the Parker County monitor provided a good cross-section of the mon itors in the western DFW area that experienced exceedances in the 2006-2010 period.” The EPA included trajectory plot maps for the Keller and Eagle Mountain Lake monitors in both the Preliminary a nd Final TSDs and also made the individual back trajectory files available for review during the comme nt period. Analysis of the plots in the TSDs indicates that 3 trajectory ‘centerlines’ directly traversed Wise County for the Keller monitor, and at least 7 trajectory ‘centerl ines’ traversed Wise County for the Eagl e Mountain Lake monitor. In addition, some other back trajectories that did not directly traverse Wise County had cen terlines near enough to Wise County to suggest a path of upwind influen ce involving Wise County emissions. Accordingly, we

concluded that there are a number of days (not just two) with back tr ajectories that suggest influence from Wise County emissions.

We also note in the record at page 23 of the Fina l DFW TSD that a review of the individual trajectory files shows that several of the days that trajecto ries passed through Wise Count y were also days that made up the 1st to 4th highest monitored values, wh ich are the values used in establishing the design value, at the Eagle Mountain Lake and Keller mon itors during the periods evaluated. These individual trajectory files were included in the supporting materials for the EPA’ s intended and final designations and were made available upon request. In fact, five of the seven back trajectories that traversed Wise County occurred on days that contributed to the Eagle Mountain Lake Design value calculation. 13

Finally, we note that the EPA Regi on 6’s reliance on HYSPLIT modeling was consistent with actions in other Regions. The EPA considered HYSPLIT results fo r 16 designations in five Regions. The fact that HYSPLIT modeling was not availabl e for all areas does not mean th at our consideration of that information, where available, was inconsistent. “While it is true that EPA was unable to use HYSPLIT modeling to inform our decisions fo r all areas, we believe that it is a valuable tool and should not be disregarded where the information is available, even if the information is not av ailable in all areas.” See RTC page 59.

Furthermore, we recognized that HYPLI T modeling is a particularly useful tool in areas such as Dallas. As we stated in the RTC, “[i]n terms of identifying potential local and regiona l source/receptor patterns, HYSPLIT wind trajectory or othe r modeling-based tools are excellent tools for determining the

13 We note that all this data is available in the record. For the Eagle Mountain Lake Monitor, the following days were the 1 st

thru 4 th High values that set the monitor’s DV. Highlighted in BOLD are the days that EPA’s HYSPLIT analysis indicates potential contribution from Wise County emissions. 2006 (6/14 – 107 ppb, 6/9 – 106 ppb, 6/28 – 98 ppb, 7/18 – 98 ppb); 2007 ( 8/14 – 121 ppb , 8/15 – 101 ppb, 10/04 – 86 ppb, 9/22 – 84 ppb , 7/25 – 84 ppb); 2008 (8/04 – 98 ppb, 6/18 – 92 ppb

, 6/23 – 86 ppb, 6/19 – 85 ppb); 2009 ( 6/25 – 100 ppb , 6/5 – 92 ppb, 6/26 – 92 ppb, 8/26 – 91 ppb, 7/2 – 91 ppb ); 2010 (6/4 – 94 ppb, 8/27 – 91 ppb, 8/28 – 83 ppb, 5/29 – 81 ppb). When there was a tie for the fourth high value we looked at trajectories for both days.frequencies for which areas potentiall y contribute to high ozone levels and are preferred over more basic assessments of wind speed and direction at a given point location (e.g., wind roses, or pollution roses). These basic assessments, such as wind roses, are pot entially misleading in cases where wind speeds are light and the wind dire ction is variable....” 14 The light and variable meteorological regime is one of the classic meteorological types that resu lts in high ozone in the DFW area.

Issue: The Petitioner includes additional information in their petition (not previously submitted through comments during the designation pro cess) indicating which specific monitored exceedance days (2006- 2010) had HYSPLIT back trajectories that passed thr ough Wise County’s airshed. Petitioner asserts that the exceedance days that the EPA identified where wind from Wise County re ached the Eagle Mountain

Lake monitor were modest exceedances and not da ys that determine the monitor’s design value.

Response: Petitioner could have submitted such information to the EPA during the public comment period and did not do so. Consideration of this in formation outside the comme nt period is not an appropriate basis for reconsideration. We also not e that the Petitioner did not provide details on how their HYSPLIT analysis was conducted nor what databases were used. Based on the analysis documented in our final TSD, we disagree with the Pe titioner’s character ization that only three days had trajectories through Wise County’s airshed. Without the specifics of the Petitione r’s analysis and their HYSPLIT files, it is not possible for the EPA to more fully discuss the nature and causes of differences with the EPA’s analysis.

III. Condensate Tank Emissions

Issue: The Petitioner claims that a new study by TCEQ indicates that emissions of VOCs from condensate storage tanks are likely much lower than reflected in the emissions estimates that the EPA

used.

Response: This comment was raised during the comment period. While we did not specifically respond to this comment for the DFW area, the comment was c onsidered by the EPA, thus is not appropriate for reconsideration. The emissions inventory (EI) consid ered in the final DFW TS D included revisions to the EI submitted by Texas in October 2011, which update d oil and gas sector pneumatic emissions. See final TSD at pages 6-7. However, Texas did not submit revised emissi ons data for condensate tanks in the oil and gas industry. The EPA based its final designation decisions on the 2008 EI as updated in

October 2011 because it was the most current and accura te data available at th e time of designations.

More generally, we considered the potential overestimation of emissions from condensate storage tanks in Texas in the context of concerns raised by Mata gorda County officials in March/April 2012. At that time, TCEQ did indicate to the EPA they were co nducting a further study that would be available in

draft form in fall 2012. 15 TCEQ indicated to the EPA during thes e discussions in spring 2012 that they did not have any updates to the state default emi ssions estimates currently used in the emission inventory. In October 2012, TCEQ did provide the EPA with a report on condensate tank emission estimates but that report has not ye t been finalized. This new technical information is not an appropriate basis for reconsideration. As noted by the Court in Catawba v. EPA , 571 F.3d 20 at 23, “Congress imposed deadlines on EPA and thus clearly envisione d an end to the designa tion process.” We do not agree that information that was not available in time for the EPA to consider while complying with the procedural requirements of the Act provides an appropriate basis for re considering the de signations. It is

14 See page 59 of the RTC.

15 Final HGB TSD, pages 6-7.important that states are able to rely on the completed designations and to move forward with the planning now required for areas.

While we are not required to consider this info rmation that was not ava ilable at the time of the designation decision, we note, as discussed elsewher e, the DFW area is NOx limited. Thus, additional changes in the VOC inventory would not have been likely to the change the conclusion that Wise County emissions contribute to nonattainment because this conclusion is based more on the relatively high emissions of NOx in Wise County.

IV. Responses to Comments

Issue: Petitioner claims that the EPA did not re spond to all significant comme nts, particularly the detailed examples of inconsistencies provided by the Texas Pipeline Asso ciation (TPA) in their comment letter dated February 2, 2012. The Petitioner incorporates these comments by reference in its

Petition.

Response: While we did not provide responses to certain comments raised during the comment period, and as referenced in your Petition, we do not believe this supports reconsideration. As provided below,

as to the technical concerns raise d, our record supports and fully explai ns our decision. Furthermore,

certain of these issues did not address whether the EPA’s five fa ctor analysis for the identified areas resulted in disparate treatment, but instead made comparisons between countie s in other nonattainment

areas and the three Te xas Counties (Wise, Hood, an d Matagorda Counties) only with regard to one or

two factors out of the five factors the EPA analyzed. Comparing counties from different areas based only on one or two of the factors from the five-factor analyses is not sufficient to support a disparate treatment argument. See Catawba County, North Carolina v. EPA , 571 F.3d 20 (D.C. Cir. 2009) (“petitioners seize upon discrete data points and ignore the very nature of the nine-factor test, which is designed to analyze a wide variety of data on a ‘case-by-case basis.’”)

We also note that unlike most other rulemaking ac tions under the CAA, C ongress did not provide a participatory role for parties other than the states and tribes. For designations, section 107(d) of the CAA sets forth a detailed and specific process between the EPA and the states. This provision provides: (i)

that Governors of states make the initial recomme ndations to the EPA for designations and boundaries; and (ii) that the EPA provide the st ates with 120 days notice of any in tended modifications to the state recommendation prior to finalizing the designation. The 120 day notification process is for the purpose of providing “such state with an opportunity to demonstrate why any proposed modification is inappropriate.” The CAA does not expressly provid e a role for any other entity (including local governments) and, moreover, expressly waives the notice and public comment process of the

Administrative Procedure Act fo r initial designations for new or revised NAAQS. Although no public comment period is required, the EPA opted to provide such a comment period for the 2012 ozone designations.

Specific issues raised by the TPA comments and in corporated by reference into the Petition are

identified below. We note that a number of the co mments raised issues for Wise, Matagorda and Hood Counties. In the final designations, the EPA designa ted Hood and Matagorda Counties as attainment and the present Petition ra ises issues solely with regard to Wise County. Thus, we summarize the issues and present our responses below only with regard to Wise County.Issue: Petitioner incorporates TPA’ s claim that there is no correlati on between increased Barnett Shale exploration and production and increase d ozone. The data illust rate that even with increased production, design values are generally down.

Response: This comment was raised during the comment period. While we did not specifically respond to this comment for the DFW area, the comment was considered by the EPA. T hus it is not appropriate

for reconsideration. The central i ssue is whether emissions from Wi se County contribute to ozone violations in nearby areas. As the record indicates, monitors in the Dallas CSA are violating the ozone standard and the EPA is required to designate areas as nonattainment if they violate the standard or

contribute to a violation in a near by area. As discussed in the RTC a nd TSD, some of the highest days during the 2006-2010 period in cluded transport of Wise County em issions (including any Barnett Shalerelated emissions) to some of the highest ozone exceedances at the Eagle Mountain Lake and Keller monitors, which are two of the DFW area’s monitors with the highest ozone levels. The TCEQ’s SAM also shows that emissions from Wise County (which would include Barnett Sh ale-related emissions) are transported to the violating monitors and that the amount of contributi on could be as high as 50% of the total impact on certain days with high ozone levels. 16

Design values and design value trends are a product of a number of variables, not simply the emissions of one or more types of emissions sources, whic h is why we perform a five-factor analysis in determining whether an area contributes to a violati on of the standard in a nearby area. Decreases in design values over time can occur due to many va riables, including decrea ses in ozone precursor emissions (such as in the DFW Nonattainment area due to federal measures and measures implemented by TCEQ in past ozone attainment de monstration SIPs). The fact that th e design value is lower (i.e., that ozone has not “increased”) does not preclude a determination that emissions from Wise County

contribute to exceedances at violatin g monitors in the DFW CSA.

Issue: Petitioner incorporates TP A’s claim that TCEQ has demonstr ated through complex modeling that it is NOx, not man-made VOCs that drive ozone formation in the DFW ar ea and the DFW NAA is generally NOx limited. Emissions from the Barne tt Shale are primarily VOCs and further the VOC species emitted by oil and gas industry are primarily st raight alkanes, and not the highly reactive alkenes

that are linked to ozone formation.

Response: As discussed in a previous response, we recognize in the TSD and RTC that the DFW Area is

NOx limited and that reductions in man-made VOC emissions only have small effects on ozone levels in the DFW area. We also recognized that VOC emissions from Barnett Shale activities are predominantly

in the form of VOCs that have low reactivit y, but would not classify them as non-reactive. 17 However, contrary to the Petitioner’s assert ion, and as documented in our emissi ons analysis in the preliminary and final TSDs and in TCEQ’s SAM, oil and gas production activity in Wise County does result in significant NOx emissions. It is pr imarily these NOx emissions that supported our determination that Wise County emissions contribute to ozone formation in the DFW area.

Issue: Petitioner incorporates TPA’s claim that wind rose charts demons trate that, on a yearly basis, the winds rarely blow into the DFW area from Wise County. The TCEQ’s findings based on the HYSPLIT model with their endpoint analysis, demonstrate th at “at most 2.87% of the trajectory endpoints from Wise County impact violating monitors.”

16 See the TCEQ source apportionment modeling files, including th e Excel Spreadsheet that was placed in the record during the final action. (Hood-Wise_DVf_Contribution_wPies.xls)

17 DFW Final TSD, pages 6-8; Houston Final TSD, pages 5-7; RTC pages 52-56.Response: Our previous responses in the HYSPLIT s ection of this enclosure address the concern about the trajectory endpoints, and also discuss why HY SPLIT modeling can be a more useful tool than annualized wind patterns esp ecially in an area like DFW that e xperiences light wind speeds and winds from variable directions. While the percentage of days when the wind carried air from Wise County was relatively low overall, our analysis indicated that the days when the air did come from Wise County, the downwind monitors had some of the highest ozone readings during the ti me period evaluated.

Issue: Petitioner incorporates TP A’s claim that other the EPA Regi ons have declined nonattainment designations based simply on prevailing winds. Fo r example, TSDs from various Regions make generalized references to prevai ling wind patterns, 30-year wind hi story, wind roses showing yearly average wind direction, and references to “predominant” wind direction.

Response: These comments did not address whether th e EPA’s five factor anal ysis for the identified areas resulted in disparate treatm ent, but instead focused only on me teorology. Therefore this does not

warrant reconsideration on this issue. Evaluation of certain aspects of only one or two factors is not appropriate because other fact ors have to be considered. As we have explaine d, the designation process involves a five factor analyses that is done case-by-case for each individual area. One cannot look at

differences between elements of one or two of the factors and conclude ther e has been disparate or inconsistent treatment. Many of the specific issues raised by the Petitioner and discussed below focus on only one or two factors, or indi vidual elements of only one or two factors, without a full comparison of how the five factors were applied. EPA will not re peat this full explanation in each instance, but it applies throughout this response.

Issue: Petitioner incorporates by reference TPA’s comments that include a list of 13 counties in other areas that they summarize as bein g upwind of nonattainment countie s and violating monitors over

20% of the time and that were desi gnated as attain ment/unclassifiable. TPA asserts that Wise, Hood, and Matagorda Counties would not be included in a nonattainment area if another EPA region had

made the decision.

Response: TPA’s comments id entify only the percentage of time a county is upwind and they do not

address how this informatio n, when considered as part of a more comprehensive five factor analysis suggests that Wise County was treated inconsisten tly with any other area. Therefore this does not

warrant reconsideration on this issue.

Issue: The Petitioner (while incorporating TP A’s comments) indicates that the EPA Region 6 incorrectly and conclusively re lied on HYSPLIT modeling and us ed it in a selective manner, while

an other Region correctly disregarded HYSPLIT modeling (e .g., the EPA Region 3 in the TSD for the Pittsburgh area) and based meteorological analyses on general historical wind patterns. The Petitioner (while incorporating TPA’s comments) furthe r indicates that the EPA failed to provide record support adequately justifying its conclusion th at HYSPLIT modeling is a proper basis for a nonattainment designation in Wise County. The Pe titioner (while incorpor ating TPA’s comments) indicated that the EPA Region 6 co nducted a ‘nit-picking’ analysis by focusing on only the days with

violations with HYSPLIT instead of using general wind patterns as have been used in other preliminary TSDs. The Petitioner listed preliminary TSDs for th e areas that did not use HYSPLIT to indicate disparate treatment of wind pa tterns by Region 6 in Texas.

Response: We refer generally to our earlier resp onses addressing the use of the HYSPLIT modeling for the DFW area. Wise County was not treated disparat ely by the EPA’s use of HYSPLIT modeling results. HYSPLIT was used in 16 areas where it was either submitted to the EPA or the EPA performed themodeling because we believed it could provide add itional insight into the factors that contribute to

nonattainment. 18 For example, as discussed previously, we explained in our TSD that HYSPLIT modeling is particularly useful for areas, such as Dallas, where wind speeds can be light and wind

direction variable.

Each of our designations decisions were based on a five-factor analysis of the unique circumstances

relevant to each area. The level of detail for meteor ological analysis can vary area-to-area. For example,

in cases where counties did not have significant emissions compared to other counties in a specific area a more general meteorological appro ach may have been sufficient.

With regard to the claim that Region 3 disreg arded HYSPLIT modeling, th is is an incorrect characterization. In the preliminary TSD for Pennsylvania, the EPA stated that:

“Further analysis of backward trajectories co uld prove helpful in re solving the affect of meteorology on this area. Pennsylvania’s March 2009 ozone recommendation did contain some NOAA HYSPLIT model backward trajectory informa tion, but not for monitors in the Pittsburgh area. The supplied information for a monitor in eastern Pennsylvania indicated that HYSPLIT 24-hour period back trajectories were highly va riable based upon the episode in question. Therefore, this information was not useful in determining the impact of meteorology on the Pittsburgh-New Castle CSA.” 19

The EPA only determined that a HYSPLIT run in eas tern Pennsylvania was not useful for evaluating the Pittsburgh area, which is located in the western portion of the state. Subsequently, as part of the analysis for the final designation decision, th e EPA Region 3 used the HYSPLIT model to further understand the meteorological transport conditions within th e region around Pittsburgh and other areas of Pennsylvania. 20

Issue: Petitioner claims (while in corporating TPA’s comments) that the EPA Region 6 incorrectly and inconsistently applied HYSPLIT to justify a nonattainment designation for Wise County. The Petitioner

further claims that HYSPLIT cannot establish a cau sal connection between winds in one area and ozone

formation in another.

Response: We agree that HYSPLIT m odeling has limits and that its prim ary use is in showing where air has traveled before reaching a certain location at a given time, thus giving an indication of what pollution sources may have contributed to the m onitored pollution level. As noted throughout the designation process, however, the EPA analyzes meteorology, includi ng HYSPLIT where available, as one component of the meteorology factor in the five-factor analysis. Th e EPA indicated in the

18 EPA considered HYSPLIT analyses in the following 16 areas for the 2008 ozone designation process: AllentownBethlehem-Easton, PA; Baltimore, MD; Ba ton Rouge, LA; Charlotte-Rock Hill, NC-SC; Chicago-Naperville, IL-IN-WI; Dallas-Fort Worth, TX; Denver-Boulder-Greeley-Ft Collins-L oveland, CO; Houston-Galves ton-Brazoria, TX; Knoxville, TN; Lancaster, PA; Memphis, TN-MS-AR ; Philadelphia-Wilmington-Atlantic C ity, PA-NJ-MD-DE; Pittsburgh-Beaver Valley, PA; Reading, PA; San Luis Obis po (Eastern San Luis Obispo), CA; an d Washington, DC-MD-VA. The TSDs for ozone designation decisions for each of thes e areas can be found in the public dock et and on the EPA’s ozone designations website. Docket No. EPA-HQ-OAR-2008-0476 and http://epa.gov/ozonedesignations/2008standards/tsd.htm.

19 Pennsylvania Preliminary TSD “Pennsylvania Area Design ations for the 2008 Ozone National Ambient Air Quality Standards,” December 2011, page 41 (Docket ID No. EP A-HQ-OAR-2008-0476-0237). We note that Pittsburgh is in Western Pennsylvania and the March 2009 HYSPLIT analysis included in Pennsylvania’s 2009 recommendation was for an ozone episode in Eastern Pennsylvania.

20 Pennsylvania Final TSD “Pennsylvania Area Designations fo r the 2008 Ozone National Ambient Air Quality Standards,” April 2012, pages 10-13, 24-28, 41-45, and 73-79 (Docket ID No. EPA-HQ-OAR-2008-0476-0632).preliminary and Final TSDs for the DFW area that th e combination of back tr ajectories and the close proximity of large emissions of oz one pre-cursors to the monitor suppor ted its decision to include Wise County. TCEQ’s SAM modeling, which is based on a wide array of information, including meteorology and emissions, further confirmed that Wise County emi ssions yield increased ozone levels at monitors in

DFW. 21

Issue: Petitioner incorporates co mments by TPA regarding the EPA Region 6’s approach to performing HYSPLIT analyses. Specifically, Petitioner refers to TPA’s comment that Region 6’s use of

HYSPLIT was inconsistent with other re gions, as detailed below:

Response: We do note that some of the HYSPLIT an alyses were conducted at different times, and the EPA used some slightly different approaches for the different HYSPLIT analyses. For example, we varied start time for the back trajectories depend ent upon when the 8-hour exceedances occurred at the monitor being evaluated. To obtain additional insight, we also separated HYSPLIT runs for several

different hours for some of the monitors th at make up the 8-hour exceedance period since the exceedance period is made up of 8 consecutive 1-hour ozone readings. We noted our methodologies for conducting the HYSPLIT analyses in the TSD and in the individual electronic HYSPLIT output files. The meteorological data on which the EPA based its HYSPLIT model analysis was available to the public. 22 On December 20, 2011 (76 FR 78872), the EPA published a notice in the Federal Register inviting public comment from interested parties other th an states and tribes on th e letters sent to states with the intended designations. Th e notice provided that any comments should be received on or before January 19, 2012, but in response to requests from several parties, including Wise County, the EPA extended the public comment period to Februa ry 3, 2012. (See 77 FR 2678, January 19, 2012). TPA requested a copy of the HYSPLIT data from the EPA on January 17, 2012. The EPA provided a copy of the meteorological and ambient monitoring data on January 19 – 24, 2012, and also posted copies of the data to the rulemaking docket.

County 1 - Issue: (Lebanon Coun ty, PA) Petitioner incorporates TPA’s comment that Lebanon County was considered as part of the Berks Count y (Reading) Pennsylvania area but was designated attainment even though the winds blew from Lebanon County in to Berks County 40 percent of the time during the summer, which was far more often th an prevailing winds blew from Wise County to the violating monitors in the DFW area. TPA recognized that Lebanon County had somewhat lower emissions than Wise County.

County 1 - Response: (Lebanon County, PA) The Peti tioner (by incorporating TPA’s comments) only discusses aspects of two factors, meteorology and emissions, and did not address how the EPA’s five factor analysis resulted in disp arate treatment of Wise County. As to the emission factor, the comment recognizes that emissions in Lebanon County were low and relies solely on the meteorology factor to suggest that Wise County was trea ted differently than Lebanon Count y. With regard to the meteorology, we note two things. First, the 40% of the time fo r wind direction from Lebanon County is a summertime predominant wind analysis and not specific to days on which the violating monitor was experiencing ozone exceedances. Second, based on comments r eceived, the EPA more closely examined the

21 Page 13 of TCEQ attachment to Governor Perry’s comment letter dated February 29, 2012, Source apportionment modeling files provided by TCEQ to EPA demonstrate that Wise County NOx emission impacts at other DFW monitors including Eagle Mountain Lake and Keller monitors is what makes up almost all of the ozone level changes due to Wise County emissions. Electronic files are avai lable in the electronic record for the Final designation. (EPA Document ID: EPAHQ-OAR-2008-0476-0633)

22 The meteorological data on which EPA based its HYSPLIT m odel analysis was accessible to the public at the NCAR FTP site at ftp://arlftp.arlhq.noaa.gov/pub/archives/edas40/.meteorology using HYSPLIT and the analysis results we re included for this area in the Final PA TSD. The EPA concluded that air flow was primarily from the Southerly direction, rather than from the Westerly direction where Lebanon County is located, at times when the monitor was recording ozone

exceedances.

County 2 - Issue: (Lawrence County, PA) TPA su mmarized information fro m the EPA Region 3’s preliminary TSD that Lawrence County had 8,960 tpy NOx a nd 3,814 tpy VOC and is located to the west and northwest of violating monitors in the Pittsburgh area. Although Region 3 noted that ozone winds in the area had strong westerly components, Lawrence County was designated attainment.

County 2 - Response: (Lawrence County, PA) TPA only discusses aspects of two factors, meteorology

and emissions. This is not sufficient to demonstrate how the EPA’s five factor analysis resulted in disparate treatment of Wise County.

County 3 - Issue: (Kent County, DE) TPA summ arized information from the EPA Region 3’s preliminary TSD that winds during ozone season come pr edominantly from the southwest. The

comment also noted that Kent C ounty's ozone design value was 74; that its NOx and VOC tpy figures were 7,667 and 5,381, respectively; that its VMT was 1,565,000; and that its population growth was +28 percent; and that the EPA wa s proposing to designate the county attainment/unclassifiable because it is "unlikely to contribute to downwind violations during most of the ozone season." The comment concluded that the facts supporting nonattainment designation of Kent C ounty were significantly stronger than those supporting the nonattainment designati on of Wise County. Nonetheless, Region 3 concluded that Kent County shoul d be proposed to be designated unclassifiable/attainment. The

comment concluded that there is no doubt that under the Region 6 method of analysis, Kent County would have been designated nonattainment.

County 3 - Response: T PA examined aspects of three of the factors: meteorology based on general wind patterns during the ozone season, emissions/emission rela ted data and air quality monitoring data. As an initial matter, we note the circum stances regarding Kent County rais ed complex issues that are not

relevant for the DFW area. There are only three counties in Delawa re. The northernmost county, New Castle, is part of the Philadelphia- Camden-Vineland, PA-NJ-MD-DE CSA. See Delaware TSD at page 4. The middle county, Kent is the Dover, DE micr opolitan statistical area (MSA) and the southern county, Sussex, is the Seaford MSA. Delaware TS D at page 18. All three Delaware Counties were designated nonattainment as part of the Phila delphia area for the 1997 ozone NAAQS. Thus, for purposes of our analysis, we evaluated all counties within the CSA and the two additional Delaware

Counties that are outside the CSA but were included as part of the Philadelphia nonattainment area for the 1997 ozone NAAQS. In addition, we also evaluate d several counties in New Jersey that are also

outside the CSA but that were in cluded as part of the designated nonattainment area for the 1997 ozone NAAQS. See Delaware TSD at pages 6 & 18.

The five-factor analysis for the counties being cons idered for inclusion in one nonattainment area will always be different than a five-fact or analysis for the counties being c onsidered for inclusion in another area. This is because the facts vary significantly among the areas. For example, the number of counties being considered can vary from one to more than 40. Additionally, the geogra phic extent of an area under consideration can vary greatly as well, with so me CSAs being as large as 100 or more miles from

north to south or east to west or both and some being significantly sma ller. For that reason, it is difficult to draw direct comparisons between two counties in different CSAs with regard to one factor, such as absolute emissions. As noted above, one distinguishi ng factor between Kent C ounty and Wise County is that Kent County is not part of th e Philadelphia CSA. We also identi fy some differences between KentCounty and Wise County below with regard to two of the factors raised in the comment. We emphasize, however, that we do not consider this information conc lusive outside the five f actor analysis. We present it simply to rebut the comment sugge sting that two areas are similar. We evaluated both Wise and Kent County based on whether their emissions were contri buting to a nearby violati on of a monitor, not on whether there was a monitor violating the standard in the county. We note that th e distance to the closest violating monitor is 20 miles for Kent County and 0.5 miles for Wise Count y. See final DFW TSD at page 3 and final Delaware TSD at page 4.

With regard to meteorology, based on comments on the adequacy of general surface wind roses, The EPA conducted HYSPLIT analysis to further ex amine meteorology. The more detailed HYSPLIT analysis indicated a wider range of wind directions for transport to exceedances in the PhiladelphiaWilmington-Atlantic City PA-NJ-DE-MD nonattainment area. The HYSPLIT analysis also showed that the winds are mostly from the south to northwest dire ctions, with the strongest direction being from the southwest during monitored ozone exceedances from 2007-2011. See Delaware TSD at pages 13-17.

With regard to emissions, out of the 19 counties ev aluated in the Philadelphi a area, Kent County ranked 14 for NOx and 17 for VOCs. Kent County ranks 14 out of 19 in VMT. While Kent County did have the highest growth rate of the counties considered, it has a relatively small population base and it had a low proportion of commuters from the county to the Ph iladelphia area. Wise County ranks 6 out of 19 counties in the Dallas CSA for NOx emissions and 4 out of 19 for VOC emissions. Population and VMT rankings are similar between Wise County and Kent County. See final DFW TSD, pages 6-14.

County 4 - Issue: (Roane County, TN) TPA su mmarized information fro m the EPA Region 4’s preliminary TSD that Roane County had emissions of 10,711 tpy NOx and 3,006 tpy VOC and was predominately upwind of nearby violating monitors.

County 4 - Response: (Roane County, TN) TPA only examined aspects of two factors, meteorology

and emissions. This is not sufficient to demonstrate how the EPA’s five factor analysis resulted in disparate treatment of Wise County.

County 5 - Issue: (Pointe Coupee Parish, LA) TPA al so claimed disparate treatment with regard to Pointe Coupee Parish, which was considered for in clusion in the Baton R ouge nonattainment area. TPA notes that Pointe Coupee Parish's NOx a nd VOC emissions tpy figures were 15,733 and 2,560 respectively and that its NOx emi ssions are higher than those for Wise County. TPA also notes that Pointe Coupee Parish's populati on density was roughly equivalent with that of Wise County. TPA points out that Region 6 stated th at "for the five-year 2006-2010 time period only 5 percent of all days with ozone concentrations greater than 75 ppb at the LS U site had wind back trajec tories that went back through Pointe Coupee Parish." The EPA Region 6 proposed a nonattainment determination for Wise County even though the winds blew across Wise County toward violating monitors far less often than the "only 5 percent" figure upon which Region 6 based its propos ed attainment/unclassifiable designation for Pointe Coupee Parish in Louisiana.

County 5 - Response: (Pointe Coupee Parish, LA) TPA examined aspects of three factors, meteorology, air quality and emissions. I n the Final Louisiana TSD, we indicated that the Big Cajun Power Plant (which we noted in our preliminary TSD is already co ntrolled) emitted 12,119 tpy in

2008 and the rest of the Parish’s emissions of ma n-made NOx were only 3,614 tpy. Furthermore, we indicated that for the 5 years of back trajectories for ozone exceedances at the LSU monitor only two back trajectories passed over Po inte Coupee Parish. Of the two back trajecto ries, one of the back trajectories barely went through the southwest corner of Pointe C oupee Parish on the opposite cornerof the Parish from the Big Cajun Power plant in the north east portion of the Parish. Therefore it is unlikely that emissions fro m the main point source in Pointe Coupee Parish c ontributed to the violating monitor for this ozone ex ceedance, leaving only one back traj ectory in 5 year s that indicates potential contribution. In comparison, 7 trajectories in 5 years for the Eagle Mountain Lake monitor in DFW passed through areas with emissions in Wise County, and five of these days were the highest monitored ozone days that helped set the monitor’s DV. We note in the RTC (page 56) that we weighed the combination of emissions and distance to a violating monitor in our evaluation comparing Hood and Wise Counties and placed more weight on contribution fr om Wise County due to Wise County’s larger emissions a nd closer proximity to a vi olating monitor. Similarly, the distance to the only violating monitor in Baton Rouge area (2008-2010 DV of 78 ppb) is approximately 18 miles for Pointe Coupee Parish (26 miles from Big Cajun) in comparis on to Wise County’s distance of 0.5 miles to the Eagle Mountain Lake m onitor (2008-2010 DV of 85 ppb).

County 6 - Issue: (Dutchess, Putnam, Orange, an d Ulster Counties, NY) TPA compared Dutchess, Putnam, Orange and Ulster Counties, which are in the New York – New Jersey – Long Island, NY -NJCT nonattainment area, with Wise County. TPA pointed out that the EPA Region 2’s preliminary TSD

indicated that Dutchess County was upwind 23 percent dur ing the summer; Putnam County 24 percent; Ulster County 29 percent; and Orange County 25 percent.

County 6 - Response: TPA only examined meteorology and did not address how the EPA’s five factor analysis resulted in disparat e treatment of Wise County.

County 7 - Issue: (Stafford Coun ty, VA) TPA also cited Stafford County Virginia, which the EPA evaluated for inclusion as part of the Washington, DC – MD-VA nonattainment area . Specifically, TPA pointed to the EPA Re gion 3’s preliminary TSD for Maryland that indicated Staffo rd County is upwind 22 percent of the time and that Stafford County should be designated atta inment/unclassifiable.

County 7 - Response: TPA generally discussed aspects of only two factors – meteorology and emissions, and did not address how the EPA’s five fact or analysis resulted in disparate treatment of Wise County.

County 8 - Issue: (Cattaraugus Reservation – Se neca Nation) TPA cites to meteorological and

emissions data from the EPA Region 2’s preliminary TSD that indicates that the Cattaraugus Reservation could have a small impact on the Ja mestown, NY nonattainment ar ea. However, the EPA proposed that the Reservation should be designated attainment/unclassifiable.

County 8 - Response: (Cattaraugus Reservation – Seneca Nation) In determining whether a county should be included as part of th e designated nonattainm ent area, we look at whether the county

contributes to nonattainment in the area. Our analys is looks at whether the ar ea’s contribution is at a level to have a significant ef fect on ambient ozone levels. See Catawba v. EPA at 39 (recognizing that “contribute” under section 107(d) is ambiguo us and does not necessarily mean any level of contribution.) In looking at our 5 factors, we note that in the Jamestown Area TSD, we determined that there were no known permitt ed sources on the Reservation an d that the population was sparse.

We also noted that the Re servation is downwind of Jamestown and transport to the non attainment area is likely to be low or nonexistent. Based on our full five-factor analys is, we concluded th at tribal lands are not contributing to the nona ttainment area. See Jamest own TSD at 4, 9 and 12.County 9 - Issue: ( Sussex County, DE ; Berks County, PA; Calvert, Fredrick, Montgomery, Prince George’s and Loudon Counties, Washington DC-MD-VA) TPA summarized information from several of the EPA Region 3’s preliminar y TSDs regarding coun ties that the EPA propos ed to designate as nonattainment and claimed that they show disparate treatmen t for Wise County. 23

County 9 - Response: The issue fo r each of these count ies was not whether the area should be designated as nonattainment but rath er in which nonattainment area the county should be included.

We note that each of th ese counties is located in the northeast U.S. corridor where nonattainment areas frequently adjoin, and the associated CSA and CBSA can incl ude 40 or more counties. Our consideration of which nonattainment area a county s hould be affiliated with raises different issues

than the issue of whethe r an area should be desi gnated nonattainment based on contribution. For example, the jurisdictional factor often plays a more significant role in these cases and, in the absence of a five-factor analysis supporti ng a contrary conclusi on, we generally will defer to the state's

recommendation as to which of the two nonattainment areas should include the county. See e.g., Pennsylvania Department of Environmental Protection v. EPA , 429 F.3d 1125, 1129 (D.C. Cir. 2005).

Our decisions for these counties do not show disparate treatment for Wise.

County 10 - Issue: (Dauphin and Yo rk Counties, PA) TPA generally referred to discussion of the EPA’s meteorology factor in EP A Region 3’s preliminary TSD. The EPA proposed to designate these

counties attainment/unclassifiab le even though meteorology indicates that Lebanon and Dauphin may

contribute to viola tions in Lancaster.

County 10 - Response: (Dauph in and York Counties, PA) TPA only discussed one factor, meteorology, and did not address how the EPA’s five fact or analysis resulted in disparate treatment of Wise County.

County 11 - Issue: (Dorchester, Wicomico, and Worcester Counties, MD) TPA referred to the EPA’s emissions and meteorology factors discussion in the EPA Region 3’s preliminary TSD. The EPA proposed to designate three Maryla nd counties attainment/unclassifia ble even though emissions from

these counties would co ntribute little to violations in downwind Sussex County, Delaware.

County 11 - Response: (Dor chester, Wicomico, and Worcester C ounties, MD) After a review of the EPA’s five factors, the EPA conc luded in the Final TSD “[a]lthough emissions from those counties might contribute to violations in downwind Sussex County, Delaware, the emissions levels from those

counties are so low that l ittle actual contribution is expected.” The EPA determ ined after weighing all

five factors that these countie s do not in fact contribute to ozone at a violating monitor.

County 12 - Issue: (Carroll and Hall Counties, GA) TPA generally discu ssed distances separating emissions sources from the violating monito rs. The EPA Region 4’s preliminary TSD proposed a designation of attainment/unclass ifiable for these counties because their distance from violating monitors limited their impact on such violating monitors.

23 These counties are: (1) Sussex County, Delaware, which was designated as a single county nonattainment area and not included as part of the Philadelphia nonattainment area; (2) Berks County, Pennsylvania, which was designated as a single county nonattainment area and not included as part of the Philadelphia nonattainment area; and (3) Calvert, Fredrick, Montgomery, Prince George’s and Loudon Counties which were included in the Washington DC-MD-VA nonattainment

area and not the Baltimore nonattainment area.County 12 - Response: TPA only discussed one aspect relating to ambient air and distance to a violating monitor, and thus did not address how the EPA’s five factor analysis resulted in disparate treatment of Wise County.

Issue: TPA (page 20 of TPA’s comm ent letter) indicated that TCEQ has already determined, in a study

done in connection with the East Texas Combustion rule, that the imposition of controls on sources in six counties, including Wise and Hood, would have such a negligible effect on conditions in the

DFW nonattainment area that it wa s not justified. Modeling sensi tivity runs were conducted by TCEQ in connection with the East Texas Combustion rule in order to assess the potential benefit of including six counties, including Wise and Hood, in the rule. According to TCEQ, "[t]hese sensitivity

runs indicate that the Dallas-Fort Worth eight-hour ozone nonattainment area would only benefit approximately 0.05 ppb reduction in ozone from incl uding these six counties under the rule." See 32

Texas Register 3303 (June 8, 2007).

Response: S ection 107(d) of the CAA requires the EPA to designate as nona ttainment any area that does not meet the air quality standard or that contributes to a vi olation of the air quality standard in a nearby area. Based on our analysis of contribution in the DFW TSD, we determined that Wise County

contributed to monitored violati ons of the 2008 ozone NAAQS and incl uded Wise County in the ozone

nonattainment area. We further note he re, that in evaluating whether an area is contributing to a current violation of the ozone NAAQS, we do not evaluate how the implementation of individual, specific measures, or the failure to implement such measures , might affect ozone levels within the area. The issue of which measures are appropriate for reducing ozone levels in an area vi olating the standard will be addressed by the states during the post- designation attainment planning process.

We also note that the modeling the TPA cites was in relation to an ol der ozone standard (84 ppb versus the current 75 ppb) and is comprised of an older meteorological episode with fewer days. Additionally, the emission estimates in the modeling do not account for the growth in emissions due to the Oil and Gas developments in north Texas since 2005/6. The modeling TPA discussed is older modeling that was for an older limited number of days episode ( 10 days) that did not have as many meteorological regimes as the more recent SAM modeling provided by TCEQ (with over 30 days) to the EPA as part of their comments for the designations of the 2007 8-hour standard. The older modeling only was conducted for evaluations of potential controls to help the DFW area attain the 1997 8-hour standard (84 ppb) and the conclusions would likely be different if the analysis was d one for the current 75 ppb standard. The modeling did not includ e revised emissions due to the growth of oil and gas emissions in Wise County and other North Texas counties that have seen increased emissions due to oil and gas field developments since 2005/6 when the emission inve ntory for the modeling c ited by the petitioner was developed for the older modeling analysis.Enclosure

EPA Response to Petition for Reconsideration

from the Texas Commission on Environmental Quality

By letter dated July 18, 2012, the Texas Commission on Environmental Quality (TCEQ) petitioned the EPA to reconsider the final area designation for Wise County in the Dallas-Fort Worth (DFW area. For the reasons discussed below, the EPA is denying the Petition. TCEQ also reque sted that the EPA stay

the effective date of the desi gnation for Wise County. Because the EPA is denying Petitioner’s reconsideration request, the EPA is also denying the stay request. Fo r the sake of clarity, we have organized this response according to th e structure of the July 18, 2012 Petition.

I. Analysis of TCEQ’s Sou rce Apportionment Modeling:

Issue: The EPA erred in failing to follow its own guidance. The guidance requires th e agency to use the Source Apportionment Modeling (SAM) re sults in a relative way using a relative respons e factor (RRF) and anchor the analysis on the base year Design Value (DV) at the m onitor, rather than using modeled future-year concentrations dire ctly in a deterministic approa ch (using direct model outputs). The EPA ignored the TCEQ SAM relative res ponse-based predictions and instead cherry-picked direct predictions from TCEQ's SAM (not anchored to any measurements) to declare that Wise County's contribution to the Eagle Mountain Lake monitor's design value wa s significant. The same principles apply where

ozone concentrations at a monitor location are allo cated to a specified set of emission sources, an approach the EPA followed in the modeling conducted for the Cross Stat e Air Pollution Rule (CSAPR).

Response: The EPA fully described the reasons it we ighed some of the model outputs provided by Texas more than others and why we evaluated Te xas’s SAM results using additional metrics. Thus, we do not

believe this issue warrants reconsideration. We note that in Texas’s February 29, 2012 comment letter attachment they included SAM resu lts using the absolute values from the model (average and maximum contributions) and also results using an RRF technique . So the EPA did not cher ry pick the results but used information provided by Texas and further evaluated Texas’s SAM results. 1 In fact, TCEQ had six different figures with the absolute values and only one figure with relative values for the DFW SAM

comments.

As discussed in greater detail in the Technical Support Document (TSD ) and in other Responses in this Petition response, we had concerns with model performance and that the episode was not reflective of the complete suite of conditions that result in ozone exceedances in the DF W area. Because of our concerns we indicated that we were putting more we ight on the day specific (absolute values) and not the average values. The RRF approach averages the impacts over all exceedances , and with a limited set of modeled days we believe this could give a potentia lly misleading assessment. Even in an analysis of the entire ozone season, we would still want to ev aluate the day-specific impacts in addition to the averaged and relative imp acts to determine if imp acts occur often enough from a specific meteorological regime that transports emissions from an area that is not transported toward the monitor in other regimes, which would potentially limit an area’s ability to reach attainment. 2 For example if a regime occurs on average only 20% of the time but drives the overall area’s design value (DV), it could have

1 See Enclosure to Texas’s February 29, 2012 comment letter. Abso lute values SAM analysis included Pages 10-14, Figures 7, 8, 9, 10, 11, 12 for the DFW area and Pages 18-27, Figures 17-32 for the Housto n/Galveston/Brazoria area.

2 In the case of Wise County and DFW we discuss in the TSD and elsewhere that the meteorological regime of Light and

Variable winds with some recirculation of air masses is one of the classic worst-case regime s that often impacts the DFW design value.significant implications for attainment. Because the RRF approach averages the impacts of all the meteorological regimes, it masks to some degree the im pact of the meteorological regime that drives the highest levels. This is of pa rticular concern in evaluati ng SAM for a determination of inclusion/exclusion of a county unde r only one meteorological regime. No te that if the EPA had used a relative reduction factor approach to estimate the day-specific impact s from the TCEQ SAM, we believe the modeled impacts from Wise County would likely have been larger. 3

SAM is a technique to look at culp ability of individual areas or s ource groups on specific area(s) of concern, and it is common to use both direct mode l results and relative modeling results. The EPA’s SAM analysis is consistent with many past SAM analyses that have been conducted by the EPA, RPOs, states, and other researchers. The EPA has never i ssued specific guidance on how SAM analysis should be performed, therefore our analys is does not conflict with the EP A guidance. The EPA has issued guidance for attainment demonstrations indicating that modeling should be analyz ed in a relative sense using the RRF technique for determining whether the emissions reduction measures in an adopted plan will achieve overall attainment/nonattainment, but the EPA has not issued guidance on how SAM should be evaluated or more specif ically how SAM should be performe d when evaluating the impact of a county on a violating monitor in the context of an attainment/nona ttainment designation decision. We

further note that to the extent that the EPA has guidance on m odeling, guidance documents are not binding rules and thus cannot “requir e” any specific action by the EPA, states or any other party. As noted, the EPA fully explained how it interpreted the SAM results in the re cord for this action.

The EPA has used SAM to support national rulemakings such as the CSAPR to assess a state’s impact on downwind receptors of concern (the EPA defined nonattainment or maintena nce receptors). In the context of this designation action, TCEQ submitted and the EPA used SAM to evaluate impacts of a single county’s emissions contribution to a downwind receptor in an adjacent nonattainment area. This is fundamentally a finer scoping of SAM compared to analyses in the EPA’s national rulemakings that

are on the scale of state-to-state impacts, so there is no direct co mparison. As discussed further in addressing other specific issues rais ed in the petition, we think there we re concerns and differences that we documented in our Final TSD that supported our c onsideration of impacts on a daily basis, and we therefore focused on the higher and maximum impact s than on the average impacts that would result from a RRF based analysis. 4 We note, however, that contrary to the suggestion by the Petitioner, when we have used SAM in national rulemakings the EPA has used absolute values as well as relative values.

Issue: TCEQ’s RRF analysis results for Wise County i ndicated the impact from Wise County emissions at the Eagle Mountain Lake monitor was 0.41 parts per billion (ppb). This value is below the EPA’s 1% threshold, therefore Wise County should not have been included in the DFW nonattainment area.

Response: As also discussed elsewhere, the EPA does not have specific guidance on evaluating SAM results nor how to evaluate the impact of emissions from a county on a nearby violating monitor in the context of a designation decision. Th e EPA evaluates each submission of SAM on a case-by-case basis, carefully assessing a number of issues including how the modeling was conducted, model performance, and available data from the analysis in order to derive appropriate conclusi ons from the results.

The EPA used a 1% of the National Ambient Air Quality Standards (NAAQS) (0.75 ppb) cutpoint in evaluating SAM results to identify days with a non- trivial impact. We did not imply that 1% of the NAAQS was a criteria threshold po int for inclusion or exclusion. O ur basis for identifying days with a

3 Electronic SAM files provided by TCEQ included a file “Hood-Wise_Dvf_Contribution_wPies.xls” that included both the absolute values and the RRF based calculated value. The absolute 2012 impacts from Wise County on the Eagle Mountain Lake monitor is 0.58 ppb (mean of 10 days used in the RRF) and the RRF based approach has a value of 0.64 ppb.

4 Final TSD SAM discussion on pages 15-20 and HYSPLIT discussion pages 14-15.non-trivial impact is discussed on page 17 of the TS D where we explained, “[o]ften in attainment demonstration modeling, controlling of sources is ev aluated and results in onl y a few tenths of a ppb change, therefore we used a 1% of the standard thre shold for the days where we would consider Hood or Wise County’s emissions to be significant.” We also note that modeling from TCEQ in a 2007 8-hour Ozone Attainment Demonstration for DFW included multip le analyses of individual control strategies and the resultant impacts on monitors in DFW area, where Texas had chosen c ontrols that provided changes of a few tenths of a ppb. In addition, we considered the recent Cross State Air Pollution Rule, which used a one percent threshold in the source apportionment modeling to determine if a state’s emissions significantly impacted a downwind state’ s nonattainment or mainte nance area. Thus we determined that an impact of 0.75 ppb, or one percen t of the 2008 ozone standa rd, which is higher than that used by the state in determin ing emissions strategies for the DF W area, would be appropriate as a metric to identify days with a nontrivial impact.

It is important to note that the number of days w ith an impact of 0.75 ppb or more is only one of the

metrics evaluated from the SAM results. In the DFW Final TSD and in supporting files, we discussed all

of the metrics used in our assessment of the SAM resu lts, and the unique factors that we weighed in our analysis of SAM results for DFW. Given the detailed daily information available for analyzing SAM for the DFW and Houston areas designations, we evalua ted the average impact, maximum impact, and an additional metric, the number of days where imp acts may be high enough that reductions might be beneficial in development of an attainment demonstration.

Issue: The EPA appears to conclude in the Final TSD that TCEQ’s SAM was not adequate because it

was not inclusive of an entire ozone season in ad dition to underestimating exceedances on many days by underpredicting peak values. To compensate for th ese concerns, the EPA relied on absolute modeled maximum concentrations to predict the potenti al contribution from Wi se County to the DFW nonattainment area. The use of photochemical modeli ng that supports a DFW attainment demonstration is appropriate and relevant eviden ce to determining the potential dow nwind contribution of Wise County to the DFW nonattainment area; it is the best eviden ce possible. It was irrational for the EPA to fail to utilize this evidence, particularly since the EPA had ample opportunity to notify TCEQ of any concerns.

The EPA's rationale for not utilizi ng the TCEQ SAM because it did not include an entire ozone season is based on the fact that the TCEQ SAM should have included days from the August-September period, which typically show higher ozone concentrations th an the June period modele d. This reason ignores the specific facts of the actual monitoring data for 2006, which the EPA does not explain. The EPA also ignored the basis and support prov ided for the June 2006 episode da ys, instead of an entire ozone

season.

TCEQ referred to the Modeling Protocol for the 2011 DFW Ozone Attainment Demonstration, provided to the EPA on October 5, 2010, noted that the 2006 base year was chosen largely because it represents an exceptionally rich set of air quality and mete orological measurements, which satisfies one of the criteria listed in the modeling guid ance for selecting episodes. The prot ocol also explai ned that in 2006, June had the most high- ozone da ys of any month (more than Augus t/September), and that all the meteorological conditions linked to formation of hi gh ozone concentrations were represented, also consistent with the guidance. TC EQ continued that th e EPA modeling guidance recommends relatively long time periods covering multiple synoptic cycles and does not require a full ozone season, so using the May 31 - July 2, 2006 period is entir ely consistent with the guidance. The EPA's explanation does not address why an ep isode based on an entire ozone season would be necessary, given that the more specific period of Ma y 31 - July 2, 2006 had the most high-ozone days of any month in 2006. The EPA's evaluation of the TCEQ SAM ignored both the factual monitoring datafor 2006 and its own guidance to use modeling in a rela tive sense, without explai ning why this deviation from established guidance was appropriate in this case.

Response: The EPA did consider the SAM results pr ovided by TCEQ and our concerns with the SAM are documented on pages15-20 of our Final TSD. 5 The EPA took these concer ns into account in our interpretation of the SAM results for purposes of designations. The EPA recognizes that model episode selection is always a balance of ma ny factors including the availability of data and the time available for completion in addition to considerations as to whet her all important meteorological regimes have been addressed. We would agree that the 2006 episode is a great improve ment over the previous 10- day episode for Dallas from 1999. Because these factors ha ve to be balanced, no model episode is perfect

and the limitations have to be considered. In this case the modeling does not include all of the meteorological regimes that can lead to high ozone and the mode l has an under prediction bias. We also noted that TCEQ’s own DFW conceptual m odel analyses, that has been included in TCEQ’s 2011 DFW Ozone Attainment Demonstration SIP and past Attainment Demonstrations SIPs, also indicated a roughly bimodal distribution of ozone exceedances with highest values in mid- to late-summer (JulySeptember), and that this latter summer period had so me different meteorological regimes than the early summer period that TCEQ included in their modeling. Based on our analysis of HYSPLIT results, the worst days for some of the DFW area monitors that set the Design Value are in the later summer. Later summer is also when the frequency of weak frontal passages are higher where we could see influence from Wise County emissions on DFW nonattainment monitors more often. The fact that not all meteorological regimes are addressed led us to wei gh day-specific impacts and maximum impacts more than average impacts. It is important to note th at since violations of the ozone NAAQS cannot be separated from exceedances, 6 looking at day specific impacts w ould be reasonable even if the model

covered a full ozone season. The fact th at the model has an under-predicti on bias led us to consider that the model was not predicting all of the exceedan ces that had occurred during the episode. We note that

the current 2011 DFW Ozone Attain ment Demonstration modeling of 2012 projected levels indicated

that the DFW area would be well under the 1997 8- hour standard, but based on 2008-10 data at the time and more recent 2011 (DV of 90 ppb) and 2012 prelimin ary data (DV of 87 ppb), the area is still well above the levels projected by the model (2012 DV of 78 ppb). This confirmed our concerns about modeling underprediction bias.

5 EPA Final TSD pp. 15-20 and including this quote on pp. 16, “[e]valuations of the conceptual model for high ozone in DFW by TCEQ, EPA and others indicates that high ozone in DFW is roughly a bimodal distribution with lower peaks in early summer (May-June) and the highest va lues in mid to late-summer (July-September) and that the mid to late summer has some different meteorological/transport regimes than the earl y summer episodes. Th erefore, TCEQ’s SAM does not include a large number of days and does not include all of the meteorology regimes conducive for ozone events in DFW and is missing the events that happen in mid to late-s ummer that often set the DFW area’s DV.”

6 In analyzing possible contributions from emissions in surrounding counties using the SAM tool, the EPA only evaluated and considered the amount of modeled impact from Wise County emissions on monitors that were violating the 2008 ozone standard according to the 2008-2 010 data. We focused our assessment on monito rs violating the standa rd and, in doing so, examined contributions on days when there were exceedances at those violating monitors. As a factual matter, it is not possible to separate “actual viola tions” from the “exceedances” that result in th e violation. Based on the form of the ozone standard, an area is determined to be violating the standard if the three consecutive year averag e of the annual fourth highest daily maximum 8-hour average ambient air quality ozone concentra tion is greater than the standa rd (0.075 ppm). Therefore, all daily maximum 8-hour averages that exceed 0.075 ppm at a violating monitor (i.e., “exceedances”) are relevant for purposes of determining whether emissions contribute to a violation at that monitor. Accordingly, we restricted our review of available modeling impact results to days with modeled exceedan ces at violating monitors. As part of this analysis, we evaluated the monitoring data during the episode modeled to determine if exceedances had actua lly occurred at the monitoron that specific day. The use of modeled exceedance days for estimating ozone using photochemical grid models is a longestablished practice for modeled attainment demonstrations. This approach is recommended by the EPA in “Guidance on the Use of Models and Other Analyses for Demonstrating Attainme nt of Air Quality Goals for Ozone, PM2.5, and Regional Haze” (EPA-454/B-07-002), and used by th e EPA to support Federal rules such as the Cross-State Air Pollution Rule.We also note that while weak frontal passages are one of the conceptual m odel meteorological regimes

for the DFW area for the 1997 8-Hour st andard and would also be expected to be one of the key regimes for the 2008 8-Hour Ozone standard, and there were not many of these in later summer 2006 compared to what occurred in other years. There were a numb er of these specific regimes in 2007 and other years, including one in August 2007 th at resulted in the highest 8-hour read ings monitored in DFW in the last 15 years (121 ppb at two monitors). The EPA’s mode ling guidance is premised upon trying to model the meteorology/emissions of past ozone exceedances such that a modeling system can be developed to accurately assess potential impacts of emission changes and predic t if an area will reach attainment by the required date. Based upon the many competing fact ors, including the amount of time it takes to run computer models and develop modeling that is pe rforming accurately enough for the task at hand the EPA’s guidance is to weigh the mitigating factor s and model enough days to develop a sufficient modeling system. The EPA’s guidance does indicate that at a minimum, areas should model enough days to capture multiple synoptic periods and many areas have been modeling complete ozone seasons to help capture enough days and meteorology combinati ons that perform adequately for use in predicting

future attainment/nonattainment levels. 7

Issue: The EPA also justified its use of the ab solute modeled maximum concentration because the TCEQ modeling under-predicted the peak 8-hour contributions in 2006. The RRF concept was developed precisely to correct fo r situations where the model over- or under-predicts the baseline

concentrations. The EPA failed to explain why the RRF concept, developed by the EPA to address both the possibility of under- and over-pre diction of photochemical models, was not applied for the purpose of evaluating the possible c ontribution of Wise County to the DFW nonattainment area.

The EPA appears to argue that the TCEQ SAM was not adequate because the TCEQ SAM used spatially averaged baseline and future ozone concen trations instead of maxima. However, since the EPA didn't actually use the RRF-based cont ribution to 2012 future de sign values, this argu ment is irrelevant. The primary reason the EPA guidance was developed supporting the use of the maximum value "near" a

monitor is to allow the RRF calculation to account for possible migration of ozone plumes due to implementing controls in an area. Instead of considering an RRF-ba sed approach, the EPA relied on the 2012 daily modeled absolute contributions. 8

Similarly, there is no rational basis for the EPA's use of a 70 ppb threshol d for selecting days to analyze

since the EPA did not use those da ys to calculate an RRF as per the EPA guidance. Instead, the EPA selected days using a 70 ppb threshold from the 2006 baseline and used corres ponding days in 2012 to look for Wise County contributions above 0.75 ppb. On many of those days in 2012, the predicted eighthour ozone concentrations were le ss than 75 or 70 ppb. The EPA should have selected days using a 75 ppb threshold from the future year modeling, but in any event, did not provide a rational basis for its

7 The EPA’s 2007 Modeling Guidance pp.122-23, “Due to increased computer speeds, it is now prudent to recommend modeling relatively long time periods. For 8-hour ozone and 24-hour PM2.5, at a minimum , (emphasis added) modeling episodes which cover full synoptic cycles is desirable. Depending on the area and the time of year, a synoptic cycle may be anywhere from 5-15 days. Modeling even longer time periods of up to a full season may simplify the episode selection process and provide a rich database with which to apply the modeled attainment test.”; pp. 140 “With the advancement in computer technology over the past decade, computer speed and storage issues are no longer an impediment to modeling long time periods. In fact, many groups have recently modeled entire summers and/or full years for ozone, PM2.5, and regional haze (Baker, 2004a) (U.S. EPA, 2005b)”

8 The TCEQ used averages instead of ma xima for its calculation of the future DV contributions because the APCA software reports averages, but notes that using averages does not necessa rily introduce bias in the RRF calculation. In fact, the total DV calculated using the APCA average-based RRF only differed from that calculated using the maximum-based RRF by 0.2 ppb (77.86 ppb vs. 78.06 ppb), so it is extremely unlikely that using spatial maxima would have made any perceptible difference in Wise County's modeled 2012 DV contribution.selection. For example, the EPA notes in the DFW TSD that "This analysis indicated Wise County emissions had even larger impacts of up to 5 ppb on the Eagle Mountain Lake monitor." The EPA refers to the 2012 contribution from Wise County to Eagl e Mountain Lake of 5.03 ppb on June 13th. While in the 2006 baseline modeling the eight-hour ozone maxi mum concentration in the 3x3 grid cell array around the Eagle Mountain Lake monitor on Ju ne 13 was 72.91 ppb, in the 2012 modeling the eighthour ozone maximum concentration in the 3x3 grid cell array around the Eagle Mountain Lake monitor was only 59.74 ppb. Although Wise County may have contributed 5.03 ppb to the 2012 modeled concentration of 59.74 ppb, the to tal 2012 predicted ozone was much less than the 2008 eight-hour ozone standard of 75 ppb. The EPA thus erred in thei r analysis by selecting days to analyze based on comparing the 2006 baseline ozone concentrations to a 70 or 75 ppb threshold. The comparison should have been made to 2012 future year ozone predicted concentrations. Furthermore, the EPA's choice to analyze days with ozone concentrations as low as 70 ppb, was erroneous, since such days could not reasonably be expected to contribute to nonattainment of the 2008 ozone NAAQS.

Response: TCEQ’s comments included both the maxi mum and average impact values for Wise County emissions based on using the absolute SAM result s for 2012 (not using the RRF technique). The RRF calculation approach for DFW was provided in one Table, in add ition to the 6 figures presenting absolute results from direct model output data (w ithout any RRF analysis). As noted above, the EPA placed less weight on the average impact, which in cludes both the average of the days, and the RRF approach which is another way to average the information over all the days above a threshold. The EPA explained our reasoning for considering modeled impact on days with values of less than 75 ppb. In the TSD (page 16) we indicated:

“Therefore, TCEQ’s SAM does not include a large number of days and does not include all of the meteorology regimes conducive for ozone events in DF W and is missing the even ts that happen in mid

to late-summer that often set the DFW area’s DV. As a result, it may be appropriate to place more weight on the maximum estimated impact and the num ber of days with sizeable impacts on violating monitors as compared to averag e impact. Another obser vation is that the evaluation used modeled exceedances for contribution and the modeling is underestimating exceedances on many days and therefore is underestimating the num ber of days of potential contribu tion. Modeling is significantly under predicting peaks by 5-20 ppb at cr itical monitors; therefore we also looked at contribution at lower modeled values (70 ppb).”

We also noted that the RRF approach indicates that a threshold lower th an the standard can be used and

should be used if there are not e nough days with modeling values above the standard in the base (2006 in this case). The EPA’s attainment demonstratio n guidance for the 1997 8-hour standard recommended using thresholds as low as 15 ppb below the standard to obtain e nough days for evaluation, especially when weighing that the base modeling is underestim ating compared to the monitoring data. For the 1997 8-hour ozone standard (84 ppb), our guidance allows basecase (2006 here) modeling days as low as 70 ppb to be used for the RRF evaluation. This supports the use of modeled days w ith thresholds of 70 and 75 ppb in the basecase 2006 modeling instead of onl y evaluating days with modeled exceedances in 2012. Although we have not revised our guidance for the 2008 8-hour ozone standard, we can try applying the same logic to the 75 ppb standard, whic h could result in values as low as 59 ppb to be allowed in RRF calculations. We also note that TCEQ’s own RRF analysis used days with values below 70 ppb and even below 60 ppb in the 2012 model projectio ns and only had 3 days out of 10 with values above 75 ppb in the RRF calculations for the Eagle Mountain Lake monitor. The use of this lower threshold in the guidance is a direct result of taking into account poten tial issues with model underprediction, etc., so the logic to use a threshold of 65 or 70 ppb is within the logic and guidance currently used for RRF analyses in our guidance. Therefore we disagr ee with TCEQ assertion that wehave not validated using a modeling threshold of 70 ppb period, when their own RRF based comments included values as low as 58 ppb in 2012.

TCEQ’s 2012 ozone modeling projecti ons using the RRF technique indica te only four monitors in the DFW area would be above the 75 ppb standard, w ith the highest value of 78.06 ppb at the Eagle Mountain Lake monitor. In contrast, the ac tual 2009-2011 DV was 83 ppb and the preliminary 2010- 2012 DV at Eagle Mountain Lake is 82 ppb. Furthermor e, 80% of the monitors in DFW are exceeding the 75 ppb standard (16 of the 20 mo nitors) and have preliminary 2012 4 th High values above 75 ppb (data ranges from 76 to 92 ppb). The DFW ar ea 2009-2011 DV was 90 ppb and the preliminary 2010- 2012 DV of 87 ppb is still 10 ppb above the standard. The monitoring data demonstrates that the 2006 model predicted levels are below current monitore d values and the modele d 2012 DV projections are underestimated by more than 10 ppb at some monitors. Therefore the 2006 levels seem more appropriate to compare to actual 2011 and preliminary 2012 monitored data.

In photochemical grid modeling the modeling domain is broken up into 4 km x 4 km squares that we call grid cells. In this case when we obtain the mode l value for further evaluation we look at the value for the grid cell the monitor is in and all grid cells immediately touc hing the grid cell with the monitor (similar to a Tic Tac Toe box with the monitor in the center). The EP A guidance is to use the maximum value from the 9 values to represent the model es timate for the monitor and TCEQ used the average value in some of their analysis. TCEQ indicates, based on one example calculation, that the difference between using the average or maximum modeled valu es in the grid cells around a monitor would not result in a perceptible difference in arguing that th eir use of the average value was acceptable. TCEQ’s example calculation was for a Future Design Value calcu lation (based on all emissions in the model) and not for a source apportionment calcu lation (which uses the model estimate for only the emissions from Wise County in this case). We note the EPA’s gui dance recommends using the maximum value of the grid cells in the grid cel l array around a monitor. From one of th e files from TCEQ we were able to evaluate what the differences are when we used the maximum vs. the average value and we did note some differences in source apportionment results. If the SAM had been evaluated using the maximum value, as EPA guidance recommends, th e values may have been larger.

II. Analysis of HYSPLIT Model Results:

Issue: The Petitioner claims that the EPA failed to quantify the number of traj ectories transecting Wise County before crossing either the Ea gle Mountain Lake or the Keller m onitor and also failed to quantify the number of trajectories that passed over other counties before pa ssing through Wise County. In each case those percentages were extremely low for the tr ajectories passing over Wise County. Furthermore, the EPA failed to provide a rationa le for how trajectorie s traversing Wise Count y indicate contribution from Wise County. Since ozone readings at a monito r are cumulative of the su m of the ozone and the ozone precursors along the trajectory path, the EPA’ s failure to quantify th e number of trajectories through other counties was irrational and in error. Furthermore, the EPA failed to explain how much ozone if any would result from the VOCs from Wise County.

Response: The EPA conducted HYSPLIT analysis of several monitors in DF W for purposes of the Preliminary Technical Support Document or TSD (December 2011) and the Final TSD (April 2012). In

the Final TSD we noted that “The HYSPLIT model yields an estimate of the path an air mass has traveled before reaching a monitor at a specific lo cation and time. Specificall y, the model provides the centerline of the probable path. By knowing where an air mass has traveled before reaching a monitor where an exceedance has occurred, one can consider what potential areas and emission sources could

have contributed to the exceedance.” The EPA include d trajectory plot maps for the Keller and EagleMountain Lake monitors in both the Preliminary a nd Final TSDs and also made the individual back trajectory files available for review during the comment period. While the EPA did not specifically state the number of trajectories that tran sect Wise County in text in the TS D, the plots in the TSDs indicate that 3 trajectory ‘centerlines’ di rectly traversed Wise County for th e Keller monitor, and at least 7 trajectory ‘centerlines’ traversed Wise County for th e Eagle Mountain Lake monitor. In addition, some other back trajectories th at did not directly traverse Wise Coun ty had centerlines near enough to Wise County to suggest a path of upwind infl uence involving Wise County emissions.

We note that a review of the individu al trajectory files shows that seve ral of the days that trajectories passed through Wise County were also days that made up the 1st to 4th highest monitored values, which are the values used in establishing the Design Valu e at the Eagle Mountain Lake and Keller monitors during the periods evaluated; these individual trajectory files were incl uded in the supporting materials for the EPA’s intended and final designations. 9

We also considered the amount of emissions in Wise County and the proximity to violating monitors. TCEQ has well established the record that the DFW area ozone levels are NOx limited and we based our analysis on the amount of Wise County NOx emissi ons and their ozone gene ration potential. In the SAM results for Wise County emissions and commen ts that TCEQ provided, there was a specific analysis that indicated that almost all of the ozone increases at mon itors were due to Wise County NOx

emissions. 10 In general the VOCs from Wise County were not considered to contribute to ozone levels very much.

III. Significance of Contribution of Oil and Gas Activity:

Issue: The Petitioner stated that current oil and gas activity levels in Wise County are unlikely to be contributing significantly to nonattainment in the DF W nonattainment area. The Petitioner noted that oil and gas production and drilling in Wise County is star ting to decline and stated that there is no evidence of a correlation between the growth in Barnett Sh ale gas production develo pment activity and ozone production in the DFW area. The Petitioner expressed concerns that the EPA may have inadvertently

9 We note that all this data is available in the record. For th e Eagle Mountain Lake Monitor, the following days were the 1st thru 4th High values that set the monitor’s DV. Highlighted in BOLD is the days that EPA’s HYSPLIT analysis indicates potential contribution from Wise County emissions. 2006 (6/14 – 107 ppb, 6/9 – 106 ppb, 6/28 – 98 ppb, 7/18 – 98 ppb); 2007 ( 8/14 – 121 ppb , 8/15 – 101 ppb, 10/04 – 86 ppb, 9/22 – 84 ppb , 7/25 – 84 ppb); 2008 (8/04 – 98 ppb, 6/18 – 92 ppb

, 6/23 – 86 ppb, 6/19 – 85 ppb); 2009 ( 6/25 – 100 ppb , 6/5 – 92 ppb, 6/26 – 92 ppb, 8/26 – 91 ppb

, 7/2 – 91 ppb ); 2010 (6/4 – 94 ppb, 8/27 – 91 ppb, 8/28 – 83 ppb, 5/29 – 81 ppb). When there was a tie for the fourth high value we looked at trajectories for both days.

10 Governor Perry’s comment letter dated February 29, 2012, pages 13, “[a]t the Weatherford (Parker County) ozone monitor NOx emissions from Hood and Wise Counties created 97-99% of the contributed ozone from these counties, while VOC emissions were only responsible for 1-3% of the contributed ozone from these counties.” See Final TSD, pages 6-8; Houston Final TSD, pages 5-7; RTC pages 52-56, including “...the VOC emissions resulting from oil & gas production activities are relatively nonreactive in the photochemical gene ration of ground-level ozone and that additionally the DFW area is NOx-limited such that VOC emissions in general do not contribute as much as NOx emissions to the generation of ground-level ozone.” And “EPA has since reviewed the updated emissions data reported by the TCEQ and notes that the revised numbers do not affect the ranking of the counties for VOC emissions. EPA’s analysis i ndicates that even with the reduced 2009 VOC emissions data, the emissions from Wise County still contribute to measured violations of the 2008 ozone NAAQS at monitors in neighboring counties. In making our final decision, we considered the reduced emissions and the reduction in drilling activity since 2009.” The Governor Perry’s comment letter dated February 29, 2012, pages 17-21, also referred to other TCEQ documents that further support that DFW area is a NOx limited regime and changes to VOC levels do not result in much impact in ozone levels: TCEQ 2011 DFW 1997 8-hour Ozone Attainment Demonstration SIP – “APPENDIX E: Protocol for the Eight-Hour Ozone Modeling of the Dallas-Fort Worth Area,” and “APPENDIX D: Conceptual Model For The DFW Attainment Demonstration SIP Revision For The 1997 Eight-Hour Ozone Standard.”“double-counted” emissions by summing the emi ssions data from the 2008 National Emissions Inventory with that of TCEQ’s 2009 Speci al Inventory for the Barnett Shale.

Response: This comment was raised during the comment period. While we did not specifically respond to this comment for the DFW area, the comment was considered by the EPA. T hus it is not appropriate for reconsideration. In the final DFW TSD, the EPA provides two emissions inventories (EIs) of nitrogen oxides (NOx) and volatile organic compounds (VOCs), which are ozone precursors (pages 7- 8). The two EIs are: 1) a 2008 EI of all Wise Count y sources and 2) a TCEQ 2009 Barnett Shale special inventory. The 2008 EI included revisions to the EI submitted by TCEQ in October 2011 which updated oil and gas sector pneumatic emi ssions (pages 6-7). The EPA did not add emissions from the Barnett Shale special inventory to the 2008 EI.

The central issue is whether emission s from Wise County contribute to oz one violations in nearby areas. As the record indicates, monitors in the Dallas CS A are violating the ozone standard and the EPA is required to designate areas as nonattainment if they vi olate the standard or cont ribute to a violation in a nearby area. As discussed in the RTC and TSD, so me of the highest days during the 2006-2010 period included transport of Wise County em issions (including any Barnett Shal e-related emissions) to some of the highest ozone exceedances at the Eagle Mountain Lake and Keller monitors, which are two of the DFW area’s monitors with the highest ozone levels. The TCEQ’s SAM also shows that emissions from Wise County (which would include Barnett Shale-re lated emissions) are transported to the violating

monitors and that the amount of c ontribution could be as high as 50% of the total impact on certain days with high ozone levels. 11 TCEQ’s SAM submitted by the Petitioner included the combination of meteorology and emissions from Wise County (i ncluding emissions from oil and gas production activity), and the resultant modeling indicated co ntributions to multiple exceedances of the ozone

standard at several monitor sites.

Design values and design value trends are a product of a number of variables, not simply the emissions of one or more types of emissions sources, whic h is why we perform a five-factor analysis in determining whether an area contributes to a violati on of the standard in a nearby area. Decreases in design values over time can occur due to many va riables, including decrea ses in ozone precursor emissions (such as in the DFW Nonattainment area due to federal measures and measures implemented by TCEQ in past ozone attainment de monstration SIPs). The fact that th e design value is lower (i.e., that ozone has not “increased”) does not preclude a determination that emissions from Wise County

contribute to exceedances at violatin g monitors in the DFW CSA.

11 See the TCEQ source apportionment modeling files, including the Excel Spreadsheet th at was placed in the record during the final action. (Hood-Wise_DVf_Contribution_wPies.xls)Enclosure

EPA Response to Petition for Reconsideration from Gas Processors Association and Texas Pipeline Association

On July 20, 2012, the Gas Processors Association and Texas Pipeline Associati on petitioned the EPA to reconsider the final area designa tion for Wise County in the Dallas- Fort Worth (DFW) area. For the reasons discussed below, the EPA is denying the Petiti on. For the sake of clarity, we have organized this response according to the struct ure of the July 20, 2012 petition.

I. Emissions Trends and Inventories

Issue: The Petition states that the EPA should consider more fully emissions trends and inventories. The Petitioner also claims that a new study by Te xas Commission on Environmental Quality (TCEQ) indicates that volatile organic compounds (VOC) em issions from condensate storage tanks are likely

much lower than reflected in the em issions estimates that the EPA used.

Response: This issue was raised during the commen t period, and we responded to these comments in our Response to Comment (RTC). Thus it is not an appropriate basis for rec onsideration. We did not look at future trends, such as future reductions th at may result from new air regulations, in this designation process because that is not an appr opriate consideration unde r the Clean Air Act. See RTC at page 58 (“[w]e agree that we did not consider the impact of ne w air regulations. The implementation of new and existing regulations should result in lower ozone precursor emissions in the future; however, for purposes of designating areas, we consider whether such areas ar e “currently contributing” (i.e., current activities) to violations of the 2008 ozone National Ambien t Air Quality Standards (NAAQS) and do not assess or pred ict future source emissions”). Our evaluation found that Wise County is currently contributing to violations of the 2008 ozone NAAQS.

To clarify, we do consider past trends such as growth rates and patterns. 1 As an example, we state in the final DFW Technical Support Document (TSD) that “[r]apid growth in population or vehicle miles traveled (VMT) in a county on the urban perimeter si gnifies increasing integrat ion with the core urban area, and indicates that it may be appropriate to include such pe rimeter area(s) as part of the

nonattainment area” See TSD page 9. This information is helpful in the five factor an alysis to determine if an area is contributing to a violation.

With regards to condensate emissions, we considered th e most recent data available at the time that we issued the designations. We consid ered potential overestimation of emissions from condensate storage

tanks in Texas in the context of concerns raised by Matagorda County officials in March/April 2012. At that time, TCEQ indicated to the EPA they were c onducting a further study that would be available in

draft form in Fall 2012. 2 In October 2012, TCEQ provided the EPA with a report on condensate tank emission estimates but that report has not yet been finalized. This new technical information is not an appropriate basis for reconsidera tion. As noted by the Court in Catawba v. EPA , 571 F.3d 20 at 23, “Congress imposed deadlines on the EPA and thus clea rly envisioned an end to the designation process.” We do not agree that information that was not availabl e in time for the EPA to consider while complying

1 See “Factors EPA Plans to Consider in Determining Nonattainment Boundaries in Designations for the 2008 Ozone NAAQS”, Attachment 2 to the December 4, 2008, EPA memorandum “Area Desi gnations for the 2008 Revised Ozone National Ambient Air Quality Standards” from Robert J. Me yers, Principal Deputy Assistant Administrator to Regional Administrators, Regions I-X.

2 Final HGB TSD, pages 6-7.with the procedural requirements of the Clean Air Act (Act or CAA) provides an appropriate basis for reconsidering the designations . It is important that st ates are able to rely on the completed designations and to move forward with the pl anning now required for the area.

Finally, we note, as discussed in the TSD, the DF W area is nitrogen oxide (NOx) limited; thus we believe it is unlikely that changes in the VOC inve ntory would affect EPA’s determination that that Wise County emissions c ontribute to nonattainment.

II. Adequacy of Record

Issue: The Petitioner states that generally Wise County is indistinguishable from Hood County, which was excluded from the nonattainment area, and that the rationale for excluding Hood County should also apply to Wise County.

Response: As documented in the final DFW TSD, Wise County is distinguishabl e from Hood County in several ways. The 2008 Emissions Inventory (EI) with revisions submitted by Texas in October 2011 shows that Wise County has approximately twic e the amount of NOx and VOC emissions. Wise County’s emissions are 11,911 tpy NOx and 17,609 t py VOC. Hood County’s emissions are 5,515 tpy NOx and 8,739 tons per year (tpy) VOC. TSD at 7. Additionally, Hood C ounty is further from violating monitors than Wise County (figure 1, page 3). We also summarized the EPA’s evaluation of the Source Apportionment Modeling (SAM) that indicated significant differences between contributions to ozone from Hood and Wise County in terms of both the maximum impact at a vi olating monitor (2008-2010 Design Value (DV)) and the number days with impacts greater than 0.75 ppb (parts per billion). See TSD at pages 6 – 14 and RTC pages 51 - 61.

III. Response To Comments

Issue: Petitioner claims that the EPA did not re spond to all significant comme nts, particularly the detailed examples of inconsistenc ies provided by them in their comme nt letter dated February 2, 2012.

Response: While we did not provide responses to certain comments raised during the comment period, and as referenced in your Petition, we do not believe this supports reconsideration. As provided below,

as to the technical concerns raise d, our record supports and fully explai ns our decision. Furthermore,

certain of these concerns did not address whether the EPA’s five f actor analysis for the identified areas resulted in disparate treatment, but instead made comparisons between countie s in other nonattainment

areas and the three Te xas Counties (Wise, Hood, an d Matagorda Counties) only with regard to one or

two factors out of the five factors the EPA analyzed. Comparing counties from different areas based only on one or two of the factors from the five-factor analyses is not sufficient to support a disparate treatment argument. See Catawba County, North Carolina v. EPA , 571 F.3d 20 (D.C. Cir. 2009) (“petitioners seize upon discrete data points and ignore the very nature of the nine-factor test, which is designed to analyze a wide variety of data on a ‘case-by-case basis.’”)

We also note that unlike most other rulemaking ac tions under the CAA, C ongress did not provide a participatory role for parties other than the states and tribes. For designations, section 107(d) of the CAA sets forth a detailed and specific process between the EPA and the states. This provision provides: (i)

that Governors of states make the initial recomme ndations to the EPA for designations and boundaries; and (ii) that the EPA provide the st ates with 120 days notice of any in tended modifications to the state recommendation prior to finalizing the designation. The 120 day notification process is for the purpose of providing “such State with an opportunity to demonstrate why any proposed modification isinappropriate.” The CAA does not expressly provid e a role for any other entity (including local governments) and, moreover, expressly waives the notice and public comment process of the

Administrative Procedure Act fo r initial designations for new or revised NAAQS. Although no public comment period is required, the EPA opted to provide such a comment period for the 2012 ozone designations.

Specific issues raised by the Petitioner are identified below. We note that a number of the comments

raised issues about the differences between the way Wise, Matagorda and H ood Counties were treated. In the final designations, the EP A designated Hood and Matagorda Counties as attainment and the present Petition raises issues solely with regard to Wise County. Thus, we summarize the issues and present our responses below only with regard to Wise County.

Issue: Petitioner claims that there is no correlation between in creased Barnett Shale exploration and production and increased ozone. The da ta illustrate that even with increased production, ozone design values are generally down.

Response: This comment was raised during the comment period. While we did not specifically respond to this comment for the DFW area, the comment was considered by the EPA. T hus it is not appropriate

for reconsideration. The central i ssue is whether emissions from Wi se County contribute to ozone violations in nearby areas. As the record indicates, monitors in the Dallas CSA are violating the ozone standard and the EPA is required to designate areas as nonattainment if they violate the standard or

contribute to a violation in a near by area. As discussed in the RTC a nd TSD, some of the highest days during the 2006-2010 period in cluded transport of Wise County em issions (including any Barnett Shalerelated emissions) to some of the highest ozone exceedances at the Eagle Mountain Lake and Keller monitors, which are two of the DFW area’s monitors with the highest ozone levels. The TCEQ’s SAM also shows that emissions from Wise County (which would include Barnett Sh ale-related emissions) are transported to the violating monitors and that the amount of contributi on could be as high as 50% of the total impact on certain days with high ozone levels. 3

Design values and design value trends are a product of a number of variables, not simply the emissions of one or more types of emissions sources, whic h is why we perform a five-factor analysis in determining whether an area contributes to a violati on of the standard in a nearby area. Decreases in design values over time can occur due to many va riables, including decrea ses in ozone precursor emissions (such as in the DFW Nonattainment area due to federal measures and measures implemented by TCEQ in past ozone attainment de monstration SIPs). The fact that th e design value is lower (i.e., that ozone has not “increased”) does not preclude a determination that emissions from Wise County

contribute to exceedances at violatin g monitors in the DFW CSA.

Issue: Petitioner claims that TCEQ has demonstrat ed through complex modeli ng that it is NOx, not manmade VOCs that drive ozone formation in the DF W area and the DFW nonattainment area (NAA) is generally NOx limited. Emissions from the Barne tt Shale are primarily VOCs and further the VOC species emitted by oil and gas industry are primarily st raight alkanes, and not the highly reactive alkenes

that are linked to ozone formation.

Response: As discussed in a previous response, we recognize in the TSD and RTC that the DFW Area is

NOx limited and that reductions in man-made VOC emissions only have small effects on ozone levels in

3 See the TCEQ source apportionment modeling files, including th e Excel Spreadsheet that was placed in the record during the final action. (Hood-Wise_DVf_Contribution_wPies.xls)the DFW area. We also recognized that VOC emissions from Barnett Shale activities are predominantly

in the form of VOCs that have low reactivit y, but would not classify them as non-reactive. 4 However, contrary to the Petitioner’s assert ion, and as documented in our emissi ons analysis in the preliminary and final TSDs and in TCEQ’s SAM, oil and gas production activity in Wise County does result in significant NOx emissions. It is pr imarily these NOx emissions that supported our determination that Wise County emissions contribute to ozone formation in the DFW area.

Issue: Petitioner claims that wind ro se charts demonstrate that, on a year ly basis, the winds rarely blow

into the DFW area from Wise C ounty. The TCEQ’s findings based on the HYSPLIT model with their endpoint analysis, demonstrate that “at most 2.87% of the trajectory endpoints from Wise County impact violating monitors.”

Response: Our response below on the HYSPLIT section of this enclosur e address the concern about the trajectory endpoints, and also di scuss why HYSPLIT modeling can be a more useful tool than annualized wind patterns esp ecially in an area like DFW that e xperiences light wind speeds and winds from variable directions. While the percentage of days when the wind carried air from Wise County was relatively low overall, our analysis indicated that the days when the air did come from Wise County, the downwind monitors had some of the highest ozone readings during the ti me period evaluated.

Issue: Petitioner claims that other EPA Regions ha ve declined nonattainment designations based simply on prevailing winds. For example, TSDs from vari ous Regions make generalized references to prevailing wind patterns, 30-year wi nd history, wind roses showing year ly average wind direction, and references to “predominant” wind direction.

Response: These comments did not address whether th e EPA’s five factor anal ysis for the identified areas resulted in disparate treatm ent, but instead focused only on me teorology. Therefore, this does not

warrant reconsideration on this issu e. As we have explained earlier , the designation process involves a five factor analysis conducted fo r each individual area. We cannot l ook at just one or two factors in

isolation to conclude there has be en disparate or inconsistent trea tment. Many of the specific issues raised by the Petitioner, and discussed below, focus on only one or two factors, without a full comparison of how the five factors were applied. EPA will not repeat this full explanation in each instance, but it applies throughout this response.

Issue: Petitioner’s comments includ e a list of 13 counties in other areas of the country that were designated as attainment/unclass ifiable. Petitioners claim th at these counties are upwind of nonattainment counties and violating monitors over 20% of the time. Petitio ner asserts that Wise, Hood, and Matagorda Counties would not be included in a nonattainment area if another EPA region

had made the decision.

Response: Petitioner’s comments iden tify only the percentage of time a county is upwind and they do not address how this information, when considered as part of a more co mprehensive five factor analysis suggests that EPA trea ted Wise County in a manner incons istent with the way we treated

other areas. Therefore, this does not warrant reconsideration on this issue.

Issue: The Petitioner indicates that the EPA Regi on 6 incorrectly and conclusively relied on HYSPLIT modeling and used it in a selective manner, while an other Region correctly disregarded HYSPLIT modeling (e.g., EPA Region 3 in the TSD for the Pittsburgh area) and based meteorological

4 DFW Final TSD, pages 6-8; Houston Final TSD, pages 5-7; RTC pages 52-56.analyses on general historical wind patterns. The Petitioner further indicates that the EPA failed to provide record support adequately justifying its conclusion that HYSPLIT modeling is a proper basis for a nonattainment designation in Wise County. The Peti tioner indicated that th e EPA Region 6 conducted a ‘nit-picking’ analysis by focusing on only the days with violations with HYSPLIT instead of using general wind patterns as have been used in othe r preliminary TSDs. The Pe titioner listed preliminary

TSDs for the areas that did not use HYSPLIT to indi cate disparate treatment of wind patterns by Region

6 in Texas.

Response: We refer generally to our responses addressing the use of the HYSPLIT modeling for the DFW area. Wise County was not treated disparatel y by the EPA’s use of HY SPLIT modeling results. HYSPLIT was used in 16 areas where it was either submitted to the EPA or the EPA performed the modeling because we believed it could provide add itional insight into the factors that contribute to

nonattainment. 5 For example, we explained in our TSD that HYSPLIT modeling is particularly useful for areas, such as Dallas, where wind speeds can be light and wind dire ction variable.

Each of our designations decisions were based on a five-factor analysis of the unique circumstances

relevant to each area. The level of detail for meteor ological analysis can vary area-to-area. For example,

in cases where counties did not have significant emissions compared to other counties in a specific area a more general meteorological appro ach may have been sufficient.

With regard to the claim that Region 3 disreg arded HYSPLIT modeling, th is is an incorrect characterization. In the preliminary TSD for Pennsylvania, the EPA stated that: “Further analysis of backward trajectories co uld prove helpful in re solving the affect of meteorology on this area. Pennsylvania’s March 2009 ozone recommendation did contain some NOAA HYSPLIT model backward trajectory informa tion, but not for monitors in the Pittsburgh area. The supplied information for a monitor in eastern Pennsylvania indicated that HYSPLIT 24-hour period back trajectories were highly va riable based upon the episode in question. Therefore, this information was not useful in determining the impact of meteorology on the Pittsburgh-New Castle CSA.” 6

EPA only determined that a HYSPLIT run in eastern Pennsylvania was not useful for evaluating the Pittsburgh area, which is located in the western portion of the state. Subsequently, as part of the analysis for the final designation decision, th e EPA Region 3 used the HYSPLIT model to further understand the meteorological transport conditions within th e region around Pittsburgh and other areas of Pennsylvania. 7

5 The EPA considered HYSPLIT analyses in the following 16 areas for the 2008 ozone designation process: AllentownBethlehem-Easton, PA; Baltimore, MD; Ba ton Rouge, LA; Charlotte-Rock Hill, NC-SC; Chicago-Naperville, IL-IN-WI; Dallas-Fort Worth, TX; Denver-Boulder-Greeley-Ft Collins-L oveland, CO; Houston-Galves ton-Brazoria, TX; Knoxville, TN; Lancaster, PA; Memphis, TN-MS-AR ; Philadelphia-Wilmington-Atlantic C ity, PA-NJ-MD-DE; Pittsburgh-Beaver Valley, PA; Reading, PA; San Luis Obis po (Eastern San Luis Obispo), CA; an d Washington, DC-MD-VA. The TSDs for ozone designation decisions for each of thes e areas can be found in the public dock et and on the EPA’s ozone designations website. Docket No. EPA-HQ-OAR-2008-0476 and http://epa.gov/ozonedesignations/2008standards/tsd.htm.

6 Pennsylvania Preliminary TSD “Pennsylvania Area Design ations for the 2008 Ozone National Ambient Air Quality Standards,” December 2011, page 41 (Docket ID No. EP A-HQ-OAR-2008-0476-0237). We note that Pittsburgh is in Western Pennsylvania and the March 2009 HYSPLIT analysis included in Pennsylvania’s 2009 recommendation was for an ozone episode in Eastern Pennsylvania.

7 Pennsylvania Final TSD “Pennsylvania Area Designations fo r the 2008 Ozone National Ambient Air Quality Standards,” April 2012, pages 10-13, 24-28, 41-45, and 73-79 (Docket ID No. EPA-HQ-OAR-2008-0476-0632).Issue: Petitioner claims that th e EPA Region 6 incorrectly and inc onsistently applied HYSPLIT to justify a nonattainment designation for Wise County. The Petitioner further claims that HYSPLIT

cannot establish a causal connection between winds in one area and ozone formation in another.

Response: We agree that HYSPLIT m odeling has limits and that its prim ary use is in showing where air has traveled before reaching a certain location at a given time, thus giving an indication of what pollution sources may have contributed to the m onitored pollution level. As noted throughout the designation process, however, the EPA analyzes meteorology, includi ng HYSPLIT where available, as one component of the meteorology factor in the five-factor analysis. Th e EPA indicated in the preliminary and Final TSDs for the DFW area that th e combination of back tr ajectories and the close proximity of large emissions of ozone precursors to the monitor supported its decision to include Wise County. TCEQ’s SAM modeling, which is based on a wide array of information, including meteorology and emissions, further confirmed that Wise County emi ssions yield increased ozone levels at monitors in

DFW. 8

Issue: Petitioner claims that EPA Region 6’s approach to performing HYSPLIT analyses was inconsistent. Specifically, Petitioner clai ms that Region 6’s use of HYSPLIT was inconsistent with other regions, as detailed below:

Response: We do note that some of the HYSPLIT an alyses were conducted at different times, and the EPA used some slightly different approaches for the different HYSPLIT analyses. For example, we varied start time for the back trajectories depend ent upon when the 8-hour exceedances occurred at the monitor being evaluated. To obtain additional insight, we also separated HYSPLIT runs for several

different hours for some of the monitors th at make up the 8-hour exceedance period since the exceedance period is made up of 8 consecutive 1-hour ozone readings. We noted our methodologies for conducting the HYSPLIT analyses in the TSD and in the individual electronic HYSPLIT output files. The meteorological data on which EP A based its HYSPLIT model analysis was available to the public. 9

On December 20, 2011 (76 FR 78872), the EPA published a notice in the Federal Register inviting public comment from interested parties other than states and tribes on the letters sent to states with the intended designations. The notice provided that any co mments should be received on or before January 19, 2012, but in response to requests from several parties, including Wise County, the EPA extended the public comment period to February 3, 2012. ( See 77 FR 2678, January 19, 2012). TPA requested a copy of the HYSPLIT data from the EPA on January 17, 2012. The EPA provided a copy of the meteorological and ambient monitoring data on January 19 – 24, 2012, and also posted copies of the data to the rulemaking docket.

County 1 - Issue: (Lebanon County , PA) Petitioner claims that Leba non County was considered as part of the Berks County (Reading) Pennsylvania area but was designated attainment even though the winds blew from Lebanon County into Berks C ounty 40 percent of the time during the summer, which was far more often than prev ailing winds blew from Wise Count y to the violating monitors in

the DFW area. TPA recognized that Lebanon County had somewhat lower emissions than Wise County.

8 Page 13 of TCEQ attachment to Governor Perry’s comment letter dated February 29, 2012. Source apportionment modeling files provided by TCEQ to EPA demonstrate that Wise County NOx emission impacts at other DFW monitors including Eagle Mountain Lake and Keller monitors is what makes up almost all of the ozone level changes due to Wise County emissions. Electronic files are avai lable in the electronic record for the Final designation. (EPA Document ID: EPAHQ-OAR-2008-0476-0633)

9 The meteorological data on which EPA based its HYSPLIT m odel analysis was accessible to the public at the NCAR FTP

site at ftp://arlftp.arlhq.noaa.gov/pub/archives/edas40/

.County 1 - Response: (Lebanon County, PA) The Peti tioner only discusses aspects of two factors, meteorology and emissions, and did not address how the EPA’s five factor analys is resulted in disparate treatment of Wise County. As to the emission factor, the comment re cognizes that emissions in Lebanon County were low and relies solely on the meteorology factor to suggest that Wise County was treated differently than Lebanon County. With regard to the meteorology, we note two things. First, the 40% of the time for wind direction from Lebanon County is a summertime predominant wind analysis and not specific to days on which the violating monitor was experiencing ozone exceedances. Second, based on comments received, the EPA more closely examined the meteorology using HYSPLIT and the analysis

results were included for this area in the Final PA TSD. The EPA concluded that air flow was primarily from the Southerly direction, rather than from th e Westerly direction wher e Lebanon County is located, at times when the monitor was recording ozone exceedances.

County 2 - Issue: (Lawrence County, PA) Petitione r summarized information from the EPA Region 3’s preliminary TSD that Lawrence County had 8,960 tpy NOx and 3,814 tpy VOC and is located to the west and northwest of violating monitors in the Pittsburgh area. Although Region 3 noted that winds in the area had strong westerly components, Lawrence County was designated attainment.

County 2 - Response: (Lawrence County, PA) Petitioner only discusses aspects of two factors, meteorology and emissions. This is not sufficient to demonstrate how the EPA’s five factor analysis resulted in disparate treatment of Wise County.

County 3 - Issue: (Kent County, DE) Petitioner su mmarized information fro m the EPA Region 3’s preliminary TSD that winds during ozone season come pr edominantly from the southwest. The

comment also noted that Kent County's ozone design value was 74 ppb; that its NOx and VOC tpy figures were 7,667 and 5,381, respectively; that its VMT was 1,565,000; and that its population growth was +28 percent; and that the EPA was proposing to designate the county attainment/unclassifiable because it is "unlikely to contribu te to downwind violations during most of the ozone season." The

comment concluded that the f acts supporting nonattainment desi gnation of Kent County were significantly stronger than thos e supporting the nonattainment designation of Wise County. Nonetheless, Region 3 concluded that Kent County should be proposed to be designated

unclassifiable/attainment. The co mment concluded that there is no doubt that under the Region 6 method of analysis, Kent County woul d have been designated nonattainment.

County 3 - Response: Petitioner examined aspects of three of the factors: meteorology based on general wind patterns during the ozone seaso n, emissions/emission related data and air quality monitoring data. As an initial matter, we note the circumstances rega rding Kent County raised complex issues that are

not relevant for the DFW area. Th ere are only three counties in De laware. The northernmost county, New Castle, is part of the Philadelphia-Camden-V ineland, PA-NJ-MD-DE CSA. Delaware TSD at page 4. The middle county, Kent is the Dover, DE metr opolitan statistical area a nd the southern county, Sussex, is the Seaford micropolitan st atistical area. See Delaware TSD at page 18. All three Delaware Counties were designated nonattain ment as part of the Philadel phia area for the 1997 ozone NAAQS. Thus, for purposes of our analysis, we evaluated all counties within the CSA and the two additional

Delaware Counties that are outside the CSA but were included as part of the Philadelphia nonattainment area for the 1997 ozone NAAQS. In addition, we also ev aluated several counties in New Jersey that are

also outside the CSA but that we re included as part of the desi gnated nonattainment area for the 1997 ozone NAAQS. See Delaware TSD at pages 6 & 18.The five-factor analysis for the counties being cons idered for inclusion in one nonattainment area will always be different than a five-fact or analysis for the counties being c onsidered for inclusion in another area. This is because the facts vary significantly among the areas. For example, the number of counties being considered can vary from one to more than 40. Additionally, the geogra phic extent of an area under consideration can vary greatly as well, with so me CSAs being as large as 100 or more miles from

north to south or east to west or both and some being significantly sma ller. For that reason, it is difficult to draw direct comparisons between two counties in different CSAs with regard to one factor, such as absolute emissions. As noted above, one distinguishi ng factor between Kent C ounty and Wise County is that Kent County is not part of the Philadelphia CSA while Wise Count y is part of the DFW CSA. We also identify some differences betw een Kent County and Wise County below with regard to two of the factors raised in the comment. We emphasize, howe ver, that we do not consider this information conclusive outside the five factor analysis. We pr esent it simply to rebut th e comment suggesting that

two areas are similar. We evaluated both Wise a nd Kent Counties based on whether their emissions were contributing to a nearby violat ion of a monitor, not on whether there was a monitor violating the standard in the county. We note that the distance to the closest violat ing monitor is 20 miles for Kent County and 0.5 miles for Wise County. See final DFW TSD at page 3 and final Delaware TSD at page

4.

With regard to meteorology, based on comments on the adequacy of general surface wind roses, the EPA conducted HYSPLIT analysis to further ex amine meteorology. The more detailed HYSPLIT analysis indicated a wider range of wind directions for transport to exceedances in the PhiladelphiaWilmington-Atlantic City PA-NJ-DE-MD nonattainment area. The HYSPLIT analysis also showed that the winds are mostly from the south to northwest dire ctions, with the strongest direction being from the southwest during monitored ozone exceedances from 2007-2011. See Delaware TSD at pages 13-17.

With regard to emissions, out of the 19 counties ev aluated in the Philadelphi a area, Kent County ranked 14 for NOx and 17 for VOCs. Kent County ranks 14 out of 19 in VMT. While Kent County did have the highest growth rate of the counties considered, it has a relatively small population base and it had a low proportion of commuters from the county to the Phila delphia area. In comparison, Wise County’s total emissions of NOx and VOC are 11,911 tpy and 17,609 t py, respectively. Wise C ounty ranks 6 out of 19 counties in the Dallas CSA for NOx emissions and 4 out of 19 for VOC emissions. Population and VMT rankings are similar between Wise County and Kent County. See final DFW TSD, pages 6-14.

County 4 - Issue: (Roane County, TN) Petitioner summarized information from the EPA Region 4’s preliminary TSD that Roane County had emissions of 10,711 tpy NOx and 3,006 tpy VOC and was predominately upwind of nearby violating monitors.

County 4 - Response: (Roane County, TN) Petitioner only examined aspects of two factors, meteorology and emissions. This is not sufficient to demonstrate how the EPA’s five factor analysis resulted in disparate treatment of Wise County.

County 5 - Issue: (Pointe Coupee Parish, LA) Petitione r also claimed disparate treatment with regard

to Pointe Coupee Parish, which was considered for inclusion in the Baton Rouge nonattainment area. TPA notes that Pointe Coupee Parish's NOx a nd VOC emissions tpy figures were 15,733 and 2,560 respectively and that its NOx emissi ons are higher than those for Wise County. Petitioner also notes that Pointe Coupee Parish's population density was roughly equivalent with that of Wise County. Petitioner points out that Region 6 stated th at "for the five-year 2006-2010 time period only 5 percent of all days with ozone concentrations greater than 75 ppb at the LS U site had wind back trajec tories that went back through Pointe Coupee Parish." The EPA Region 6 proposed a nonattainment determination for WiseCounty even though the winds blew across Wise County toward violating monitors far less often than the "only 5 percent" figure upon which Region 6 based its propos ed attainment/unclassifiable designation for Pointe Coupee Parish in Louisiana.

County 5 - Response: (Pointe Coupee Parish, LA) Petitioner examined aspects of three factors, meteorology, air quality and emissions. I n the Final Louisiana TSD, we indicated that the Big Cajun Power Plant (which we noted in our preliminary TSD is already co ntrolled) emitted 12,119 tpy in

2008 and the rest of the Parish’s emissions of ma n-made NOx were only 3,614 tpy. Furthermore, we indicated that for the 5 years of back trajectories for ozone exceedances at the LSU monitor only two back trajectories passed over Po inte Coupee Parish. Of the two back trajecto ries, one of the back trajectories barely went through the southwest corner of Pointe C oupee Parish on the opposite corner of the Parish from the Big Cajun Po wer plant in the northeast portion of the Parish. Therefore, it is unlikely that emissions fro m the main point source in Pointe Coupee Parish c ontributed to the violating monitor for this ozone ex ceedance, leaving only one back traj ectory in 5 year s that indicates potential contribution. In comparison, 7 trajectories in 5 years for the Eagle Mountain Lake monitor in DFW passed through areas with emissions in Wise County, and five of these days were the highest monitored ozone days that helped set the monito r’s DV. We note in the RTC (page 56) that we weighed the combination of emissions and distance to a violating monitor in our evaluation comparing Hood and Wise and put more weight on contribution from Wise Count y due to Wise County’s larger emissions and closer proximity to a violating monitor. Similarly, the distance to the only Baton Rouge area violating monitor (2 008-2010 DV of 78 ppb) is approximately 18 miles for Pointe Coupee Parish (26 miles from Big Cajun) in comparison to Wise C ounty’s distance of 0.5 miles to the Eagle Mountain Lake monitor (2008-2010 DV of 85 ppb).

County 6 - Issue: (Dutchess, Putnam, Orange, and Ulster Counties, NY) Pe titioner compared Wise County with Dutchess, Putnam, Orange an d Ulster Counties, which are in the New York – New Jersey – Long Island, NY -NJ-CT nonattainment area. Petitioner pointed out that the EPA Region 2’s preliminary TSD indicated that Dutchess County was upwind 23 pe rcent during the summer; Putnam County 24 percent; Ulster County 29 per cent; and Orange County 25 percent.

County 6 - Response: Petitioner only examined meteorology and did not address how the EPA’s five factor analysis resulted in di sparate treatment of Wise County.

County 7-Issue: (Stafford County, VA) Petitioner also cited Stafford Count y Virginia, which the EPA evaluated for inclusion as part of the Washington, DC-MD-VA nonattainment area . Specifically,

Petitioner pointed to the EPA Region 3’s preliminary TSD for Maryland that indicated Stafford County is upwind 22 percent of the time and th at Stafford County should be designated

attainment/unclassifiable.

County 7 - Response: Petitioner generally discussed aspects of only two factors – meteorology and emissions, and did not address how the EPA’s five fact or analysis resulted in disparate treatment of Wise County.

County 8 - Issue: (Cattaraugus Reservation – Se neca Nation) Petitioner cites meteorological and

emissions data from the EPA Region 2’s preliminary TSD that indicates that the Cattaraugus Reservation could have a small impact on the Ja mestown, NY nonattainment ar ea. However, the EPA proposed that the Reservation should be designated attainment/unclassifiable.County 8 - Response: (Cattaraugus Reservation – Seneca Nation) In determining whether a county should be included as part of th e designated nonattainm ent area, we look at whether the county

contributes to nonattainment in the area. Our analysis looks at whether the area’s contribution is at a level to have a significant ef fect on ambient ozone levels. See Catawba v. EPA at 39 (recognizing that “contribute” under section 107(d) is ambiguo us and does not necessarily mean any level of contribution.) In looking at our 5 f actors, we note that in the Jame stown Area TSD that there were no known permitted sources on the Rese rvation and that the population wa s sparse. We al so noted that

the Reservation is downwind of Jame stown and transport to the nonattainment area is likely to be low

or nonexistent. Based on our full anal ysis of all of the factors, we c oncluded that tribal lands are not contributing to the nonattainment ar ea. Jamestown TSD at 4, 9, 12.

County 9 - Issue: ( Sussex County, DE ; Berks County, PA; Calvert, Fredrick, Montgomery, Prince George’s and Loudon Counties, Washington DC-MD-VA) Petitioner summarized in formation from several of the EPA Region 3’s preliminary TSDs regarding counties that the EPA proposed to designate as nonattainment and claimed that th ey show disparate trea tment for Wise County. 10

County 9 - Response: The issue fo r each of these count ies was not whether the area should be designated as nonattainment but rath er in which nonattainment area the county should be included.

We note that each of th ese counties is located in the northeast U.S. corridor where nonattainment areas frequently adjoin, and the associated CSA and CBSA can incl ude 40 or more counties. Our consideration of which nonattainment area a county shou ld be affiliated raises different issues than the

issue of whether an area should be designated nonattainment based on contribution. For example, the jurisdictional factor often plays a mo re significant role in these cases and, in the absence of a fivefactor analysis supporting a co ntrary conclusion, we generally will defer to the state's

recommendation as to which of the two nonattainment areas should include the county. See e.g., Pennsylvania Department of Environmental Protection v. EPA , 429 F.3d 1125, 1129 (D.C. Cir. 2005).

Our decisions for these counties do not show disparate treatment for Wise.

County 10 - Issue: (Dauphi n and York Counties, PA) Petitioner generally referred to discussion of the EPA’s meteorology factor in the EPA Region 3’s preliminary TSD. The EPA proposed to designate

these counties attainment/uncla ssifiable even though meteorology indicates that Lebanon and Dauphin may contribute to violations in Lancaster.

County 10 - Response: (Dauph in and York Counties, PA) Petitioner only discussed one factor, meteorology, and did not address how the EPA’s five fact or analysis resulted in disparate treatment of Wise County.

County 11 - Issue: (Dorchester, Wi comico, and Worcester Counties, MD) Petitioner generally referred

to the EPA’s emissions an d meteorology factors discussion in the EPA Region 3’s preliminary TSD. The EPA proposed to designate three Maryland counties attainment/unc lassifiable even though

emissions from these counties would contribute little to violations in downwind Sussex County,

Delaware.

10 These counties are: (1) Sussex County, Delaware, which was designated as a single county nonattainment area and not included as part of the Philadelphia nonattainment area; (2) Berks County, Pennsylvania, which was designated as a single county nonattainment area and not included as part of the Philadelphia nonattainment area; and (3) Calvert, Fredrick, Montgomery, Prince George’s and Loudon Counties which were included in the Washington DC-MD-VA nonattainment

area and not the Baltimo re nonattainment area.County 11 - Response: (Dor chester, Wicomico, and Worcester C ounties, MD) After a review of the EPA’s five factors, the EPA conc luded in the Final TSD “[a]lthough emissions from those counties might contribute to violations in downwind Sussex County, Delaware, the emissions levels from those

counties are so low that l ittle actual contribution is expected.” The EPA determ ined after weighing all

five factors that these countie s do not in fact contribute to ozone at a violating monitor.

County 12 - Issue: (Carro ll and Hall Counties, GA) Petitioner generally discussed distances separating emissions sources from the violating monito rs. The EPA Region 4’s preliminary TSD proposed a designation of attainment/ unclassifiable for these counties becau se their distance from violating monitors limited their impact on such violating monitors.

County 12 - Response: Petitioner only discussed one aspect rela ting to ambient air and distance to a violating monitor, and thus did not address how the EPA’s five factor analysis resulted in disparate treatment of Wise County.

Issue: Petitioner (on page 20 of their comment letter) indicated that TCEQ has already determined, in a study done in connection with the Ea st Texas Combustion rule, that the imposition of controls on sources in six counties, including Wise and Hood, would have such a negligible effect on conditions in the DFW nonattainment area; therefore, th e Combustion rule was not justified. Modeling sensitivity runs were conducted by TCEQ in conn ection with the East Texas Combustion rule in order to assess the potential benef it of including six counties, includ ing Wise and Hood, in the rule. According to TCEQ, "[t]hese sensitivity runs indicate that the Dallas-Fort Worth eight-hour ozone nonattainment area would only benefit approximately 0.05 ppb reduction in ozone from including

these six counties under the rule." See 32 Texas Register 3303 (June 8, 2007).

Response: S ection 107(d) of the CAA requires the EPA to designate as nona ttainment any area that does not meet the air quality standard or that contributes to a vi olation of the air quality standard in a nearby area. Based on our analysis of contribution in the DFW TSD, we determined that Wise County

contributed to monitored violati ons of the 2008 ozone NAAQS and incl uded Wise County in the ozone

nonattainment area. We further note he re, that in evaluating whether an area is contributing to a current violation of the ozone NAAQS, we do not evaluate how the implementation of individual, specific measures, or the failure to implement such measures , might affect ozone levels within the area. The issue of which measures are appropriate for reducing ozone levels in an area vi olating the standard will be addressed by the states during the post- designation attainment planning process.

We also note that the modeling the Petitioner cites was in relation to an older ozone standard (85 ppb versus the current 75 ppb) and is comprised of an older meteorological episode with fewer days. Additionally, the emission estimates in the modeling do not account for the growth in emissions due to the Oil and Gas developments in north Texas sin ce 2005/6. The modeling Petitioner discussed is older modeling that was for an older limited number of da ys episode (10 days) that did not have as many meteorological regimes as the more recent SAM m odeling provided by TCEQ (with over 30 days) to the EPA as part of their comments for the designatio ns of the 2007 8-hour standard. The older modeling only was conducted for evaluations of potential controls to help the DFW area attain the 1997 8-hour standard (85 ppb) and the conclusion s would likely be different if the analysis was done for the current 75 ppb standard. The modeling and associated emission inventory cited by the Petitioner did not include revised emissions reflecting the growth of oil and gas emissions in Wise County and other North Texas counties since 2005/6. Since that time, these counties have seen increased emissions due to oil and gas field developments.IV. Analysis of HYSPLIT and Potential Impact of Wise County Emissions

Issue: The Petitioner claims that the EPA’s HYSPL IT analysis was not conclusive and given undue weight. Specifically, the Petition claims that the HYSPLIT modeling gives only an indication of possible contribution to downwind nonattainment. Further, Peti tioner claims that the EP A should provide greater clarity as to how HYSPLIT is app lied and what weight HYSPLIT resu lts are given in making the Wise County designation decision.

Response: Petitioner raised the HYSPLIT issue du ring the comment period and the EPA responded to those comments. See RTC pages 59, 60. Therefore, rec onsideration is not appropriate. Our record fully supports our decision. The EPA’s record explains that HYSPLIT is a useful tool for determining areas where air originates or passes through on the way to a monitored ozone exceedance. As we stated in the RTC, “[i]n terms of identifying potential local a nd regional source-receptor patterns, HYPLIT wind trajectory or other modeling based tools are excellent tools for determining the frequencies for which areas potentially contribute to high ozone levels a nd are preferred over more basic assessments of wind speed and direction at a given point locations (e.g., wind roses, or pollution roses). The basic assessments, such as wind roses, are potentially mi sleading in cases where wind speeds are light and the

wind direction is variable. . .” 11 The light and variable meteorologi cal regime is one of the classic meteorological types that results in high ozone in the DFW area.

We conducted HYSPLIT analysis for several monito rs in DFW for purposes of both the Preliminary TSD (December 2011) and the Final TSD (April 2012). In the Final TSD, we noted that “[t]he HYSPLIT model yields an estimate of the path an air mass has traveled before reaching a monitor at a specific location and time. Specifi cally, the model provides the cente rline of the probable path. By knowing where an air mass has traveled before reach ing a monitor where an exceedance has occurred, one can consider what potential areas and emission s ources could have contribu ted to the exceedance.” In the Final TSD at page 14, we stated, “[w]e focu sed on the Keller and Eagle Mountain Lake monitors in Tarrant County and the Parker County monitor becau se the Keller and Eagle Mountain Lake monitors have recorded some of the highest ozone levels in the region, and inclusion of the Parker County monitor provided a good cross-section of the mon itors in the western DFW area that experienced exceedances in the 2006-2010 period.” The EPA included trajectory plot maps for the Keller and Eagle Mountain Lake monitors in both the Preliminary a nd Final TSDs and also made the individual back trajectory files available for review during the comme nt period. Analysis of the plots in the TSDs indicates that 3 trajectory ‘centerlines’ directly traversed Wise County for the Keller monitor, and at least 7 trajectory ‘centerl ines’ traversed Wise County for the Eagl e Mountain Lake monitor. In addition, some other back trajectories that did not directly traverse Wise County had cen terlines near enough to Wise County to suggest a path of upwind influen ce involving Wise County emissions. Accordingly, we

concluded that there are a number of days (not just two) with back tr ajectories that suggest influence from Wise County emissions.

As provided in the Final DF W TSD, a review of the i ndividual trajectory files s hows that several of the days that trajectories passed through Wise County were also days that made up the 1st to 4th highest monitored values, which are the values used in esta blishing the design value at the Eagle Mountain Lake and Keller monitors during the periods evaluated. In fact, five of the seven back trajectories that traversed Wise County occurred on days that c ontributed the Eagle Moun tain Lake Design value

11 See page 59 of the RTC.calculation. 12 The individual trajectory f iles were included in the suppor ting materials for the EPA’s intended and final designations.

V. Source Apportionment Modeling (SAM) a nd Opportunity for Public Comment:

Issue: The Petitioner claims that the EPA did not provide opportunity for public comments on the use of TCEQ’s SAM modeling. Specifically, the Petition clai ms that the EPA did not present any source apportionment modeling in its proposed designation d ecision, yet relied on such modeling in making the final designation deci sion for Wise County.

Response: While we agree that our analysis of the state’s SAM mode ling was not available for comment at the time of proposal, we do not believe this issue warrants reconsideration. Fi rst, in response to the EPA’s 120-day letter notifying it of the intended designations, the state submitted, among other things, the SAM data and results. Our evaluation of the SAM was in response to such submittal and was consistent with the process esta blished by Congress in section 107(d) of the Act. For initial area designations for a new or revised NAAQS, section 107(d)(1) of the CAA sets forth a detailed and specific process between the EPA and the states. This provision provides: (i) th at Governors of states

make the initial recommendations to the EPA for de signations and boundaries; and (ii) that the EPA provide the states with 120 days notice of any intended modifications to the state recommendation prior to finalizing the designation. The 120-da y notification process is for the purpose of providing “such state with an opportunity to demonstrate why any proposed modification is inappropr iate.” The CAA does not expressly provide a role for any other entity and, moreover, expre ssly waives the notice and public comment process of the Administra tive Procedure Act for initial de signations for new or revised NAAQS. See CAA section 107(d)(2)(B). Although no public comment period is required, the EPA opted to provide such a comment period for the ozone designations for the 2008 ozone NAAQS. We appropriately followed the process specifically c ontemplated by the Act. The EPA’s response to TCEQ’s SAM is detailed in the EPA’s final TSD. See Final DFW TSD at 15-20.

Second, and as a general matter, agencies are not required to provide an additional opportunity for public comment on material supporting a final rule, su ch as responses to comments or on information supporting a response to a comment. Such an appr oach would result in an unworkable endless rulemaking process. See Catawba , 571 F.3d at 50-51 (In rejecting a claim by New York that it should have been allowed additional input into the EPA’s d ecision to rely on a different monitor for evaluating contribution for the final designation th an it did for the intended designa tion the court noted that such an ongoing exchange with the states is inconsistent with the CAA and that “Congress imposed deadlines on EPA and thus clearly envisioned an end to the designation process.”) See also International Fabricare

Institute v. EPA , 972 F.2d 384, 399 (D.C. Cir. 1992) (notice and comment is not intended to result in “interminable back-and-forth”) and Community Nutrition Institute v. Block , 749 F.2d 50, 58 (D.C. Cir. 1984) (agency is not required to provide additional opportunity to comment on its response to comments).

12 We note that all this data is available in the record. For the Eagle Mountain Lake Monitor, the following days were the 1 st

thru 4 th High values that set the monitor’s DV. Highlighted in BOLD are the days that EPA’s HYSPLIT analysis indicates potential contribution from Wise County emissions. 2006 (6/14 – 107 ppb, 6/9 – 106 ppb, 6/28 – 98 ppb, 7/18 – 98 ppb); 2007 ( 8/14 – 121 ppb , 8/15 – 101 ppb, 10/04 – 86 ppb, 9/22 – 84 ppb , 7/25 – 84 ppb); 2008 (8/04 – 98 ppb, 6/18 – 92 ppb

, 6/23 – 86 ppb, 6/19 – 85 ppb); 2009 ( 6/25 – 100 ppb , 6/5 – 92 ppb, 6/26 – 92 ppb, 8/26 – 91 ppb, 7/2 – 91 ppb ); 2010 (6/4 – 94 ppb, 8/27 – 91 ppb, 8/28 – 83 ppb, 5/29 – 81 ppb). When there was a tie for the fourth high value we looked at trajectories for both days.Issue: The Petitioner claims that as part of the fina l rule the EPA used a new 1% standard in analyzing the source apportionment modeling (SAM), and it did not offer a rational basis for its use or opportunity for comment. Furthermore, the Petition claims that EP A was inconsistent in our use of the 1% standard and specifically raises concerns with the EPA’s re view and conclusions of SAM analysis for three counties in the Chicago area.

Response: The EPA considered SAM in its deci sion making only in areas where it was provided by states or others during the public process. Since the SAM was provided during the comment period, as discussed above, our evaluation consequently could not be available for public comment.

SAM results were available for the EPA considerati on in the designation proce ss for only three areas, Dallas, Houston and Chicago, because those were th e only areas where it was developed and submitted by states or other entities. The EP A does not have specific guidance on how to evaluate the impact of emissions from a county on a nearby violating m onitor in the context of a designation decision. Moreover, in the few instances where SAM was subm itted for our consideration, the form and type of

the information varied between areas. The EPA ev aluated each submission of SAM on a case-by-case basis, carefully evaluating a number of issu es including how the modeling was conducted, model performance, and available data from the analysis in order to determine how to appropriately evaluate

the results.

For the SAM submitted for Dallas and Houston, we cons idered other recent modeling work that could serve as a guide. Our basis for iden tifying days with a non-trivial impacts is discussed on page 17 of the TSD where we explained, “Often in attainment demonstration modeling, controlling of sources is evaluated and results in only a few tenths of a ppb ch ange, therefore we used a 1% of the standard cut point for the days where we would consider Hood or Wise County’s emissions to be significant.” We also note that modeling from TCEQ in a 2007 8-h our Ozone Attainment Demonstration for DFW included multiple analyses of individual control stra tegies and the resultant impacts on monitors in DFW area, where Texas had chosen controls that provided changes of a few tenths of a ppb. 13 In addition, we

also note that the EPA concluded in the recent Cross State Air Pollution Rule, that a “one percent of the NAAQS” impact result in the source apportionment modeling was appropriate to determine if a state’s emissions significantly impacted a downwind state’s nonattainment or maintenance area. 14 Thus we believe it was reasonable to examine the frequency of a modeled impact of 0.75 ppb, or one percent of the 2008 ozone standard, as a metric to id entify days with a nontrivial impact. 15

In addition, the number of days exce eding the one percent (0.75 ppb) cut point is only one of the metrics

evaluated from the SAM results. In the DFW Final TSD and in supporting files, we discussed all of the metrics used in our assessment of the SAM results, and the unique factors that we weighed in our analysis of SAM results for DFW. Using the deta iled daily information available to the EPA for analyzing SAM for the DFW and Houston areas designations, we evaluated the average impact, maximum impact, as well as the number of mode led days exceeding 0.75 and 0.70 ppm where the Wise County impact was above 0.75 ppb. These other model out put metrics also help explain the impact of Wise County. For example, on some specific modeled da ys the impact of Wise County was much larger than 0.5 ppb and as much as 5 ppb at the Eagle Mountai n Lake Monitor which is one of the monitors in

13 See the sensitivity runs in TCEQ’s 2007 DFW 1997 8-hour ozone Attainment Demonstration SIP - APPENDIX D: DFW Future Case (2009) Sensitivity Tests.

14 See Cross State Air Pollution Rule an d the Technical Support Document for the rule(Docket ID: EPA-HQ-OAR-2009- 0491 at www.regulations.gov)

15 TSD page 17, TCEQ’s 2007 DFW 1997 8-hour ozone Attainment Demonstration SIP – Appendix D: DFW Future Case (2009) Sensitivity Tests.DFW that sets the DV for the DFW nonattainment area. 16 Also, it is important to remember that the SAM results were only piece of information that we cons idered in our five factor analysis that resulted in our determination that Wise County cont ributes to nonattainment in the DFW area.

Our decision to use 1 % of the NAAQS or 0.75 ppb, as a cut point to identify days with a non-trivial impact is supported by our record and a count of such days is only one of the metrics we evaluated from the SAM results. As stated in our TSD, the 2008 Emi ssions Inventory for Wise County shows that Wise County’s nitrogen oxide emissions of 11,911 tpy are the 6th highest of the 19-county DFW Combined Statistical Area (CSA) and the County’s volatile organic compound emissions of 17,609 tpy are the fourth highest of the 19 counties. See TSD pages 6-7. The TSD demons trates that there are six ozone monitors violating the standard in the two counties adjacent to Wise County (TSD Figure 1, page 3) and notes that Wise County is less than 1⁄2 mile from a violating monitor with a design value of 0.085 parts per million (TSD 2008 to 2010 data, pages 5 and 23). We also evaluated meteorological transport patterns during exceedances using N OAA’s HYSPLIT model. These patter ns indicate that emissions from Wise County are transported to the DFW ozone monitors violating the standard based on 2008- 2010 data, and we conclude that the Wise County emi ssions are large enough that they can contribute to ozone exceedances on certain days. See TSD pages 14-17, 19, 20, and 23.

Finally, the Region 6 evaluation of SAM was not inconsistent with actions taken by other Regional offices. Again, our record supports our decision on this issue. The EPA considered SAM for the Houston area in the same way we considered it for Dallas because the SAM submitted for both areas was similar in how it was performed and the type of information provided. The only other area for which the EPA had SAM results was for the Chicago area. The SAM submitted for the Chicago area was sufficiently different that direct comparis ons to the DFW area analysis are not generally appropriate. In the Chicago area SAM, the EPA wa s provided the average m odeled impact levels on

estimated exceedances for an entire ozone season. Emphasis on the average modeled impact is more appropriate when a full ozone season of model results is available. A full seas on of modeling results was not available for the DFW area. Indiana had provided SAM modeling that evalua ted the impact of three Indiana counties on a monitor in the greater Chi cago area. The reported impacts from two Counties (Lake and Porter) were about 2 ppb and 4 ppb. The SA M result for the third Indiana County (Jasper) indicated less than 0.5 ppb impact. In evaluating th is result, the EPA was aw are that the modeling did

not reflect reductions that had been achieved at a large power plant in Jasper County, reducing the Jasper County total emissions of NOx by more than 50%. 17 Based on the analysis of all the factors, including

the SAM and additional emission redu ctions, the EPA decided to include Lake and Porter counties, and not to include Jasper County, Indi ana within the nonattainment area. As with the contribution level evaluated for Wise County, the contribution levels discussed in the Region 5 Chicago Final TSD do not represent a bright line criterion fo r inclusion or exclusion of a count y. Moreover, the inclusion of two counties with an average contribution of 2 and 4 ppb and exclusion of a county with 0.5 ppb in the Chicago area is not inconsistent w ith inclusion of Wise County based in part on a count of days with greater than 0.75 ppb contribu tion in the Dallas area. As noted above, however, for both the Chicago and Dallas areas, this considerati on was simply one element of one of the five factors the EPA considered in determining whether to include coun ties as part of the desi gnated nonattainment area.

16 TSD page 20

17 Region 5 TSD, Original 2008 NOx emissions quantified as 19,788 tons/year and value was footnoted as “... updated emissions data were provided for Jasper County showing 2011 NOx emission levels of 9,791 tons.”VI. Concern About Treatment of the Oil and Gas Industry

Issue: The Petitioner claims that the designation of Wise County shoul d be reconsidered because of a perceived bias by former Regional Administrator Dr . Armendariz against the oil and gas industry that may have played an undue role in the designa tion process.

Response: The EPA’s final designa tion decision for the DFW area was based on the EPA’s evaluation of the data and technical information, extensive and thoughtful consideration of input from TCEQ and other interested parties. The EPA’ s national Office of Air and Radia tion works closely with technical staff in EPA’s regional offices to ensure that decisi ons are based on the factual record and are consistent across the country. As demonstrated in the TSD acco mpanying the EPA’s intended designations issued in December, 2011 and the TSD accompanying th e final designation on April 30, 2012, the EPA performed a thorough assessment of information rele vant to five designati ons-related factors in determining which areas should be included as part of the DFW nonatta inment area. The final decision was made by Administrator Lisa Jackson based on the re cord before the EPA. We further note that there

are other Texas counties where oil a nd gas production and activity occur that were initially considered for inclusion into a nonattainment area, but were ultimately not included. For example Hood County, Texas and Matagorda County, Texas we re considered and proposed for inclusion in their respective areas. However, following a review of comments from Texas and from public commenters and upon

further evaluation of all available da ta relevant to their contribution to ozone violations, we determined

those counties should not be include d as part of a nonattainment area. Our record details those decisions.