## Memorandum

To: Docket

From: Jeff Hunt, Air Planning Team, EPA Region 10

Re: Technical Support Document - Washington State Implementation Plan and Interstate Transport Requirements for the 2006 24-hour Fi ne Particulate Matter National Ambient Air Quality Standards

Date: May 13, 2015

Recommendation

Based on the weight of the evidence eval uated in this Technical Support Document (TSD), it is recommended the EPA pr opose approval of the Washington State Implementation Plan (SIP) as adequately addressing the interstate transport requirements of CAA section 110(a)(2)(D)( i)(I) for the 2006 24-hour PM 2.5 National Ambient Air Quality Standards (NAAQS). This section of the CAA requires that the Washington SIP contain adequate provisions prohibiting emissions which will contribute significantly to nonattainment in, or interfere with maintenan ce by, any other state with respect to the

2006 24-hour PM 2.5 NAAQS. The Washington SIP meet s these CAA requirements as

detailed below.

This TSD is organized as follows:

Table of Contents

I. Interstate Transport and Washington A. Summary of Proposed Action B. Summary of Washington Submittal C. Summary of EPA Eval uation and Conclusion

II. Transport Assessment Methodology

A. Discussion of Nonattainment and Maintenance Receptor Selection Methodology B. Factors Considered in Transport Anal ysis for Nonattainment and Maintenance
Receptors

III. Transport Assessment for Nonattainment Receptors

A. Introduction
B. Transport to Western States

1. California2 2. Idaho

3. Montana
4. Oregon

5. Utah
C. Transport to Eastern States

IV. Transport Assessment for Maintenance Receptors

A. Introduction
B. Transport to Western States

1. California

2. Montana

3. Utah
C. Transport to Eastern States

V. Appendix – PM 2.5 IMPROVE Data 1. Overview of IMPROVE Monitoring Network Sites 2. Idaho and Idaho/Oregon Border - IMPROVE Data for the Years 2009-2013

3. Montana - IMPROVE Data for the Years 2009-2013

4. Nevada - IMPROVE Data for the Years 2009-2013

5. Utah - IMPROVE Data for the Years 2009-2013 6. Wyoming - IMPROVE Data for the Years 2009-2013 7. California/Oregon Border - IM PROVE Data for the Years 2009-2013 8. Oregon/Washington Border - IM PROVE Data for the Years 2009-2013

I. Interstate Transport and Washington

I.A. Summary of Proposed Action

Background:

Section 110(a)(1) of the Clean Ai r Act (CAA) requires each state to submit to the Environmental Protection Agency (EPA), within three years (or such shorter period as the Administrator may prescribe) after the promulgation of a primar y or secondary National Ambient Air Quality Standard (NAAQS) or any revision thereof, a State Implementation Plan (SIP) that provides for the “implementation, maintenance, and enforcemen t” of such NAAQS. The EPA refers to these specific submittals as “infrastructure” SIPs because they are intended to address basic structural SIP requirements for new or re vised NAAQS. For the 2006 24-hour PM 2.5 NAAQS, these

infrastructure SIPs were due on September 21, 2009.3 CAA section 110(a)(2) includes a lis t of specific elements that “[ e]ach such plan submission” must meet. The interstate transport provisions in CAA section 110(a)(2)( D)(i) (also called “good neighbor” provisions) require each state to submit a SIP that c ontains adequate provisions prohibiting air emissions that will have certain adverse air quality effects in other states. CAA section 110(a)(2)(D)(i) identifies four distinct el ements related to the impacts of air pollutants transported across state lines. In this action, the EPA is addressing the first two elements of this section, specified at CAA section 110(a)(2)(D )(i)(I) – the requirement that a state SIP:

“contain adequate provisions—

(i) prohibiting, consistent with the provisions of this subchapter, any source or other type of emissions activity within the State from emitting any air pollutant in amounts which

will—

(I) contribute significantly to nonattainment in, or interfere with maintenance by,
any other State with respect to an y such national primary or secondary
ambient air quality standard”

Proposed Action:

In this action, we are proposing to approve the Washi ngton SIP as adequately addressing the requirements of CAA section 110(a )(2)(D)(i)(I) for the 2006 24-hour PM 2.5 NAAQS. We
believe that it is reasonable to co nclude that, based on the weight of the evidence, emissions from sources in Washington do not si gnificantly contribute to nona ttainment or interfere with

maintenance of the 2006 24-hour PM 2.5 NAAQS in any other state.

I.B. Summary of Washington Submittal

On May 11, 2015, the State of Washington submitted a SIP revision to address the requirements of CAA section 110(a)(2)(D)( i)(I) for the 2006 24-hour PM 2.5 NAAQS (Washington 2006 PM 2.5 Interstate Transport submittal). 1 In the submittal, Washington cited the EPA-approved rules codified in 40 CFR 52 Subpart WW and concluded that these ru les contain adequate provisions prohibiting sources or types of em ission activity within the State from emitting any air pollutant in any amounts that will contribute significantly to nonattainment in any ot her state with respect

to the 2006 24-hour PM 2.5 NAAQS. Specifically, the EPA-appr oved regulations at Washington Administrative Code (WAC) 173-400-113, and local clean air agency corollaries, require any owner or operator of a proposed new source, wh ether major or minor, to demonstrate to the satisfaction of the Washington Department of Ecol ogy (Ecology) or a local clean air agency that the proposed source’s projected emissions will not cause or significantly c ontribute to a violation

1 The Washington 2006 PM 2.5 Interstate Transport submittal addresse s only the CAA section 110(a)(2)(D)(i)(I) requirements for the 2006 PM 2.5 NAAQS. The EPA addressed CAA section 110(a)(2)(D)(i)(II) for the 2006 PM 2.5 in a separate action (May 12, 2015, 80 FR 27102). In addition, we previously approved the Washington SIP for 110(a)(2)(D)(i) with respect to the 1997 PM 2.5 NAAQS on January 13, 2009 (74 FR 1591). Finally, Washington intends to address the requirements of CAA section 110(a)(2)(D)(i)(I) with respect to the 2012 PM 2.5 NAAQS in a
future action.4 of any NAAQS. This demonstration is not cons trained to impacts solely in Washington. For example, all estimates of ambient concentratio ns must be based on the requirements of 40 CFR part 51, Appendix W which look to the point of maximum concen tration, not a jurisdictional boundary.

The submittal also pointed to emission inve ntories for Washington State and emissions

inventories used in the Cross State Air Pollution Rule (CSAPR) modeling analysis. 2 The 2005 base case used in the CSAPR analysis included values for nitrogen oxides (NO
x ) and sulfer dioxide (SO 2 ) emissions of 357,674 tons and 57,580 tons, correspondingly. The NO
x and SO 2 values for Washington in 2012 are 268,870 tons a nd 38,581 tons, indicating that Washington’s emissions were reduced by 24.8% and 33%, resp ectively. Washington’s submittal attributes these reductions to Federal engine and fu el regulations, Washington’s inspection and maintenance (I/M) program, initiatives to decreas e diesel exhaust (e.g. exhaust retrofits, Clean Diesel Grants, Northwest Ports Clean Air St rategy), Washington’s Air Operating Permit Program, and Best Available Re trofit Technology (BART) reduc tions from the regional haze

program.

The Washington 2006 PM 2.5 Interstate Transport submittal also analyzed areas thought to be experiencing problems attaining and maintaining the 2006 24-hour PM 2.5 NAAQS in the immediately surrounding states of Idaho and Or egon. Washington concluded that if there were no significant impacts to the immediately borderi ng states of Idaho and Oregon, it was unlikely that Washington would significantly impact more distant western states given the geography and generally low background levels of monitored PM 2.5 . The EPA supported Washington’s analysis for Idaho and Oregon with an independent anal ysis of other western states experiencing problems attaining and maintaining the 2006 24-hour PM 2.5 NAAQS (California, Montana, and Utah) as well as eastern states.

Washington supported their conclusion with in formation from the Western Regional Air Partnership (WRAP) Technical Support System, in cluding Interagency M onitoring of Protected Visual Environments (IMPROVE) data. 3 This IMPROVE data measures impacts at monitors in National Parks and wilderness areas (class I areas) which provide information on background levels helping evaluate whethe r transported emissions from Was hington sources in terfere with

2006 24-hour PM 2.5 NAAQS maintenance efforts in other st ates. Specifically, the submittal asserted that winter-time high pressure systems with weak transport and near calm surface winds

are characteristic of 2006 24-hour PM 2.5 NAAQS exceedances in the west – as evidenced in the Technical Support Documents (TSD s) of surrounding nonattainment areas reviewed as part of

2 See Emissions Inventory Final Rule TSD , Technical Support Document (TSD) for the final Transport Rule, Docket ID No. EPA-HQ-OAR-2009-0491, June 28, 2011, at Tables 7-1 and 7-2

3 The Interagency Monitoring of Protected Visual Environments (IMPROVE) program is a cooperative measurement effort governed by a st eering committee composed of representa tives from Federal and regional-state organizations. The IMPROVE monitoring program was established in 1985 to aid the creation of Federal and State implementation plans for the protection of visibility in class I areas. The objectives of IMPROVE include establishing current aerosol conditions in mandatory class I areas; and identifying chemical species and emission sources responsible for existing man-made visibility impairment.5 the Washington submittal. 4 The submittal stated that for thes e winter-time inversion events that lead to exceedances, transported PM 2.5 and precursors from outside the local cold pool is small to nonexistent and is not generall y a contributing factor to PM 2.5 concentrations in these western exceedances areas. Washington asserted that low winter transport of PM 2.5 and its precursors is supported by the IMPROVE monitoring data. Speci fically, most of the IMPROVE monitors in the areas surrounding Washington show distinct seasonal variation wi th most of monitoring sites

evaluated in the submittal showi ng generally low background levels. 5

The Washington submittal concluded that, based on the weight of the evidence, specifically:

 The low concentrations of daily PM 2.5 measured at IMPROVE monitors surrounding Washington during times that exceedances occur.

 The significant role meteorology and topography play in the conditions that lead to 24-hour PM 2.5 NAAQS violations in surrounding states.

I.C. Summary of EPA Evaluation and Conclusion

To determine whether the CAA section 110(a)(2)(D )(i)(I) requirement is satisfied, the EPA must

determine whether a state’s emissions contribute significantly to nonattainm ent or interfere with maintenance in other states. If this factual finding is in the negative, then CAA section 110(a)(2)(D)(i)(I) does not require an y substantive changes to a st ate’s SIP to impose additional emissions controls to alleviate interstate transpor t. Consistent with the EPA’s approach in the eastern United States (1998 NOx SIP call, the 2005 CAIR, and the 2011 Transport Rule), we are evaluating potential interstate transport from Wash ington to other states with respect to specific monitors identified as having nonattainment and/or maintenance problems, which we refer to as “receptors.” 6

It is important to note that on August 21, 2012, th e U.S. Court of Appeals for the DC Circuit issued a decision to vacate the Transport Rule. See EME Homer City Generation, L.P. v. E.P.A.,
696 F.3d (DC Cir. 2012) cert. granted , 2013 U.S. Lexis 4801 (2013). The DC Circuit also

ordered the EPA to continue implementing CAIR in the interim. However, on April 29, 2014, the U.S. Supreme Court reversed and remanded the D.C. Circuit’s ruling and upheld the EPA’s approach in the Transport Rule. EPA v. EME Homer City Generation, L.P ., 134 S.Ct. 1584 (2014). The Supreme Court generally upheld the EP A’s approach in the Transport Rule for the issues in front of the Supreme Court for revi ew, and on October 23, 2014, the DC Circuit lifted the stay on the Transport Rule. 7

4 Docket # EPA–HQ–OAR–2007–0562 for the 2006 PM 2.5 nonattainment area designations (November 13, 2009, 74 FR 58688) and Docket # EPA–HQ–OAR–2012–0918 for the 2012 PM 2.5 nonattainment area designations (January 15, 2015, 80 FR 2206).

5 Washington 2006 PM 2.5 Interstate Transport Submittal, Appendix A, IMPROVE PM 2.5 data for the period 2009-

2013.

6 See NO

x SIP Call, 63 FR 57371 (October 27, 1998); CAIR, 70 FR 25172 (May 12, 2005); and Transport Rule or Cross-State Air Pollution Rule, 76 FR 48208 (August 8, 2011).

7 USCA Case #11-1302, Document # 1518738, Filed 10/23/2014.6 While our evaluation is consistent with the Tr ansport Rule approach, the State of Washington was not covered by either CAIR or the Transpor t Rule, and the EPA made no determinations in either rule regarding whether emissions from s ources in Washington significantly contribute to

nonattainment or interfere with maintenance of the 2006 24-hour PM 2.5 NAAQS in another state, nor did it attempt to quantify Washington’s obligation. 8

Evaluation:

In this action, we have evaluated the informati on available and have determined that no single piece of information is by itself dispositive of the issue. As region-wide modeling such as exists for the Transport Rule of the 2006 24-hour PM 2.5 NAAQS for the western portion of the United States, including Washington, is no t available for this particular NAAQS, we believe that it is appropriate to evaluate the total weight of all the evidence which, taken together can be used to evaluate whether Washington emissions significan tly contribute to nonattainment or interfere

with maintenance of the 2006 24-hour PM 2.5 NAAQS in any other state. See, Guidance on the Use of Models and Other Analyses for Demonstrating Attainment of Air Quality Goals for Ozone, PM2.5, and Regional Haze, EPA -454/B-07-002, April 2007.

We believe that the Washington 2006 PM 2.5 Interstate Transpor t submittal and other supplemental evidence explained herein provid es important information on the meteorology (including temperature inversi ons, mixing zones, and the like, for example), topography, geography, background levels, and technical analysis of violating areas in surrounding states and that this information genera lly supports a conclusion that emissions from sources in Washington do not significantly contribute to nonattainment or interfere w ith maintenance of the 2006 24-

hour PM 2.5 NAAQS in any other state. In order to reach a proposed conclusion, we believe it is
necessary to supplement the information provided in the Washington 2006 PM 2.5 Interstate Transport submittal with a review of the monitors in other states that are appropriate nonattainment and maintenance receptors.

We also have reviewed monitoring data collected at National Parks and wilderness areas (class I areas) in the west which we believe may be considered re presentative of background (data provided in section V. Appendix to this TSD). In addition, we have reviewed technical documentation produced by the EPA and states du ring the designations and attainment planning processes for the 2006 24-hour PM 2.5 NAAQS under part D, title I of the CAA. This technical documentation addresses atmospheric scien ce, meteorology, topography and sources of PM 2.5 in Washington and surrounding states in the west. While this info rmation was developed for SIPs under part D, title I of the CAA, we believe the information helps inform our evaluation of interstate transport requirements at CAA section 110(a)(2)(D)(i)(I) for the 2006 24-hour PM 2.5 NAAQS.

Conclusion:

Based on the following weight of the evidence, we propose to conc lude that the Washington SIP meets the requirements of CAA section 110(a)(2)(D)(i)(I) fo r the 2006 24-hour PM 2.5 NAAQS:

8 Ibid.7  The evidence in the Washington 2006 PM 2.5 Interstate Transport submittal that shows the significant role meteorology and topography play in the conditions that lead to violations of the

24-hour PM 2.5 NAAQS in Washington and surrounding western states.

 The evidence from monitoring data collected at National Parks and wilderness areas (class I
areas) in the west that indicates th ere are low background levels of PM 2.5 in class I areas located between Washington and identified receptors, a nd in the west in general, at the times when violations in the west typically occur (winter months).

 The evidence from technical support documents pr oduced by the states and the EPA through the designations and attainment pla nning process for the 2006 24-hour PM 2.5 NAAQS that indicates

violations of the 24-hour PM 2.5 standard in the western states are generally driven by wintertime inversion meteorology in areas impacted by major mountain ranges including the Cascade Range, the Wasatch Front, the Sierra Nevada Range, and other significant topography.

II. Transport Assessment Methodology

II.A. Discussion of Nonattainment and Maintenance Receptor Selection Methodology

On September 25, 2009, the EPA issued a guidance memorandum that provides recommendations to states for making submissi ons to meet the requirements of CAA section 110(a)(2)(D)(i) for the 2006 24-hour PM 2.5 standards. See Memorandum from William T. Harnett, Director, Air Quality Policy Division, to Regional Air Di vision Directors, Regions I-X, “Guidance on SIP Elements Required Under S ections 110(a)(1) and (2 ) for the 2006 24-Hour Fine Particle (PM 2.5 ) National Ambient Air Quality St andards (NAAQS),” September 25, 2009 (“2006 24-hour PM 2.5 NAAQS Infrastructure Guidance” or “Guidance” ). 9 The Guidance recommends that each state explain in its SI P submission for section 110(a)(2)(D)(i)(I) SIP

whether or not emissions from sources in the state contribute significan tly to nonattainment or interfere with maintenance of the NAAQS in any ot her state, and to address any such impacts if they exist. See Guidance at 3, 4. The Guidance states as follows:

The state’s conclusion must be supported by an adequate technical analysis. Information to support the state's determination with respect to significant contribution to nonattainment might include, but is not limited to, information concerning emissions in the state, meteorological conditions in the state and the potentially impacted states,

monitored ambient concentrati ons in the state and the poten tially impacted states, the

distance to the nearest area that is not a ttaining the NAAQS in another state, and air quality modeling. The EPA believes that it would be appropriate for states to make this assessment by considering the impact of current or future emissions on nearby nonattainment areas, and evaluating the air quality impact and potential mitigation strategies. 10

9 Available at: http://www.epa.gov/ttn/caaa/t1/mem oranda/20090925_harnett _pm25_sip_110a12.pdf

10 Guidance at 3.8 To determine whether the CAA section 110(a)(2)(D )(i)(I) requirement is satisfied, the EPA must

determine whether a state’s emissions contribute significantly to nonattainm ent or interfere with

maintenance in downwind areas. If this fact ual finding is in the negative, then section 110(a)(2)(D)(i)(I) does not require any changes to a state’s SIP. If, however, the evaluation

reveals that emissions from sources within the state do contribute signific antly to nonattainment or interfere with maintenance in other states, th en the state must adopt substantive provisions to mitigate those emissions. The state could ach ieve any required reductions through traditional command and control programs, or at its own elec tion, through participati on in a cap and trade program. Consistent with the EPA’s approach in the 1998 NOx SIP call, the 2005 CAIR, and the 2011 Transport Rule, 11 the EPA is evaluating these impacts with respect to specific monitors identified as having nonattainment and/or ma intenance problems, which we refer to as “receptors.” 12 The EPA notes that no single piece of info rmation is by itself dispositive of the issue. Instead, the total weight of all the evidence taken together is used to evaluate significant contributions to nonattainment in, or interf erence with maintenan ce of, the 2006 24-hour PM 2.5 NAAQS in another state.

A receptor may be a downwind location that is currently violating the 2006 24-hour PM 2.5 NAAQS, has violated in the past , is projected to violate in the future, or may have trouble maintaining the NAAQS in the future. Nonatta inment and maintenance receptors can be identified using future year mode ling, recent ambient data, or both.

If appropriate future year modeling is not available, 13 nonattainment and maintenance receptors can be identified using recent am bient air quality monitoring data. For this action, we evaluated the three most recent consecutive three-year periods for which complete, quality-assured and certified air quality data were available (cov ering a five-year period) to calculate “design

values” 14 for those period. We evaluated the design values for monitors located in the following western states, which were not included in the modeling domain for the Transport Rule: Arizona, California, Colorado, Idaho, Mont ana, Nevada, New Mexico, Oregon, Utah, Washington and Wyoming. 15

Because the EPA uses the most recent three- year design value period for purposes of promulgating air quality designations and redesignations, it is logi cal to use the most recent 3- year period to identify “nonattainment” receptors . However, previous violations of the NAAQS are indicative of an air quality problem that may retu rn in the future. The y ear to year variability of emissions and/or meteorology may cause an area to have trouble maintaining the NAAQS in the future. Therefore, we have identified “mai ntenance” receptors by examining previous years of data. This methodology is conceptually similar (although not iden tical) to the methodology

11 See NO

x SIP Call, 63 FR 57371 (October 27, 1998); CAIR, 70 FR 25172 (May 12, 2005); and Transport Rule or Cross-State Air Pollution Rule, 76 FR 48208 (August 8, 2011).

12 Air quality designations are not relevant to th e methodology for identif ying these “receptors.”

13 Available modeling data should be evaluated for the inte nded purpose. If modeling data is used to establish nonattainment and/or maintenance receptors, it should be fo r an appropriate future year (within the time frame of downwind attainment dates) and model performance should be shown to be acceptable for the upwind and downwind areas being considered.

14 “Design value” means the “calculated concentration accordi ng to the applicable appendix of [40 CFR part 50] for the highest site in an attainment or nona ttainment area.” 40 CFR 58.1 (definitions).

15 We did not evaluate design values for Alaska or Hawaii.9 that the EPA used in the Transport Rule to identify “nonattainment” and “maintenance”
receptors.

In this action we have a pplied the following methodology:

Similar to the Transport Rule analysis, we ex amined ambient data which spanned a five-year period. This allows examination of year to year variability. The three most recent consecutive three-year design value periods at the tim e of our analysis are 2009-2011, 2010-2012, and 2011-

2013. 16

1) Nonattainment receptors are those sites that are violati ng the NAAQS in the most recent
three-year period (2011-2013). 17

2) Maintenance receptors are those receptors thatshow attainment in the most recent threeyear design value period ( 2011-2013) but violated the NAAQS in at least one of the previous two periods (2 009-2011 and/or 2010-2012).

Ambient data included the three most recent offi cial design value periods available at the time of the analysis. The official design values are posted by the Office of Air Quality Planning and Standards (OAQPS) on the Air Trends website and are available at: http://www.epa.gov/airtrends/values.html. Also informing this list was the EPA’s AirData website: http://www.epa.gov/airquality/airdata/.

The western receptors identified using this met hodology and analyzed in this action are shown in

Table 1 below. Receptors with 24-hour PM 2.5 design values above the 24-hour PM 2.5 standard of 35μg/m 3 for the most recent three-year period (2011-2013) are listed as nonattainment receptors. Receptors with 24-hour PM 2.5 design values at or below the 24-hour PM 2.5 standard of 35μg/m 3 for the most recent three-year period (2011-2013), but above the standard for at least one of the previous three-year periods ( 2009-2011 or 2010-2012), are listed as maintenance receptors.

To evaluate the potential for si gnificant contribution to nonattain ment in other states, the EPA first evaluated potential transport to the wester n states with identified nonattainment receptors: California, Montana, Oregon, and Utah. 18 To evaluate the potential for interference with maintenance in other states, the EPA evaluated po tential transport to the western states with identified maintenance receptors: California, Montana, and Utah. 19

16 As noted above, the EPA can consider data from these years for states in the western United States as such data is not impacted by the remanded CAIR.

17 When evaluating recent design values, it is not necessary to average the desi gn values together to create a fiveyear weighted average. Weighted average data is only necessary when projecting modeling data to the future, since modeled projections are generally based on only a single year (or less) of modeled meteorology.

18 As this analysis focuses on interstate transport, EPA did not evaluate the impact of Washington emissions on receptors within Washington.

19 Using the methodology described, no receptors were identified in Arizona, Colorado, Nevada, New Mexico, Washington, and Wyoming.10 Table 1: List of Western Counties with Daily PM 2.5 Nonattainment or Maintenance Receptors

State County 2006 NAAQS 24-hr

PM 2.5 NAAQS

designated

nonattainment area Site 24-hr standard (μg/m 3 )

2009-

2011 2010-

2012 2011-

2013 Receptor Type

California Fresno San Joaquin Valley 060190011 58 NA 59 NA 62 NA Nonattainment
California Fresno San Joaquin Valley 060195001 54 NA 54 NA 58 NA Nonattainment
California Fresno San Joaquin Valley 060195025 48 NA 53 NA 63 NA Nonattainment

California Imperial 060250005 38 NA 32 A 42 NA Nonattainment
California Inyo 060271003 36 NA 33 A 38 NA Nonattainment
California Kern San Joaquin Valley 060290014 62 NA 58 NA 65 NA Nonattainment
California Kern San Joaquin Valley 060290016 55 NA 47 NA 60 NA Nonattainment
California Kings San Joaquin Valley 060310004 46 NA 43 NA 49 NA Nonattainment
California Kings San Joaquin Valley 060311004 57 NV 54 NA 60 NA Nonattainment

California Los Angeles Los Angeles-South

Coast Air Basin 060370002 36 NA 31 NV 28 A Maintenance

California Madera San Joaquin Valley 060392010 55 NV 51 NA 52 NA Nonattainment
California Merced San Joaquin Valley 060470003 43 NA 41 NA 42 NA Nonattainment
California Merced San Joaquin Valley 060472510 39 NA 40 NA 49 NA Nonattainment

California Riverside Los Angeles-South

Coast Air Basin 060658005 39 NA 37 NA 38 NA Nonattainment

California Sacramento Sacramento 060670006 35 A 31 A 36 NA Nonattainment
California San Joaquin Sa n Joaquin Valley 060771002 38 NA 36 NA 45 NA Nonattainment
California San Joaquin Sa n Joaquin Valley 060772010 41 NV 38 NA 37 NA Nonattainment
California Stanislaus San Joaquin Valley 060990005 50 NA 44 NA 51 NA Nonattainment
California Stanislaus San Joaquin Valley 060990006 51 NA 49 NA 53 NA Nonattainment
California Tulare San Joaquin Valley 061072002 47 NA 47 NA 56 NA Nonattainment

Idaho Ada 160010010 19 A 27 A 53 NA Nonattainment
Idaho Franklin Logan 160410001 50 NA 47 NA 42 NA Nonattainment

Idaho Lemhi 160590004 38 NA 38 NA 38 NA Nonattainment

Idaho Shoshone 160790017 38 NA 38 NA 40 NA Nonattainment

Montana Lewis and

Clark 300490026 37 NA 33 A 29 A Maintenance

Montana Silver Bow 300930005 39 NA 34 A 39 NA Nonattainment
Oregon Crook 410130100 31 A 31 A 39 NA Nonattainment
Oregon Klamath Klamath Falls 410350004 39 NA 35 A 40 NA Nonattainment
Oregon Lake 410370001 36 NA 34 A 56 NA Nonattainment
Oregon Lane Oakridge 410392013 39 NA 38 NA 40 NA Nonattainment
Utah Box Elder Salt Lake City 490030003 40 NA 37 NA 37 NA Nonattainment
Utah Cache Logan 490050004 42 NA 37 NA 46 NA Nonattainment
Utah Davis Salt Lake City 490110004 40 NA 34 A 35 A Maintenance
Utah Salt Lake Salt Lake City 490350003 50 NA Nonattainment
Utah Salt Lake Salt Lake City 490353006 45 NA 38 NA 41 NA Nonattainment
Utah Salt Lake Salt Lake City 490353010 41 NA 35 A 39 NA Nonattainment

Utah Utah Provo 490490002 35 A 29 A 45 NA Nonattainment

Utah Utah Provo 490494001 41 NA 32 NV 44 NA Nonattainment

Utah Utah Provo 490495008 38 NA 41 NV 42 NV Nonattainment

Utah Utah Provo 490495010 42 NA 35 A 46 NA Nonattainment11 State County 2006 NAAQS 24-hr

PM 2.5 NAAQS

designated

nonattainment area Site 24-hr standard (μg/m 3 )

2009-

2011 2010-

2012 2011-

2013 Receptor Type

Utah Weber Salt Lake City 490570002 41 NA 37 NA 40 NA Nonattainment
Utah Weber Salt Lake City 490571003 37 NA 33 A 35 A Maintenance NA = Not attaining; A = attaining; NV = incomplete data; Blank = monitor not operating

Data sources: AirTrends http://www.epa.gov/airtrends/values.html and AirData http://www.epa.gov/airquality/airdata/

Note: receptors with design values (DV) th at would otherwise attain the 24-hour PM 2.5 standard from 2011 to 2013 but for flagged wildfire exceptional events are exclud ed from this list (i.e. Ravalli, Montana DV = 27 μg/m 3 ; Missoula, Montana DV = 24 μg/m 3 ; and Jackson, Oregon DV = 34 μg/m 3 ).

II.B. Factors Considered in Transport Anal ysis for Nonattainment and Maintenance Receptors

Consistent with the recommendations in the Gu idance, the EPA reviewed multiple factors to evaluate the weight of the evidence. The EPA evaluated emission i nventory data, ambient monitoring data, and meteorological conditions within the State of Washington. Emission inventories used in the Transport Rule modeli ng analysis provide the following amounts of NO
x and SO 2 emissions for Washington in 2012: 268,870 tons of NOx and 38,581tons of SO 2

. 20 This is a significant reduction from the 2005 base ye ar emissions inventories of 357,674 tons of NO
x and 57,580 tons of SO 2 , with continuing emission reductions projected in 2014.

In addition, the EPA reviewed PM 2.5 monitoring data at National Parks and wilderness areas in the west that the EPA believes may be consider ed representative of western regional background

levels of PM 2.5 . As explained 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, at 98, April 2007, a weight of eviden ce analysis appropriately considers such additional models and supplemental analyses. Sp ecifically, we reviewed five years of data

collected at the IMPROVE 21 monitoring network at specific National Parks and wilderness areas (class I areas) in Washington and on the Idah o/Oregon border (Craters of the Moon National Monument, Sawtooth Wilderness, Hells Canyon W ilderness, and Starkey), in Utah (Bryce Canyon National Park, Canyonlands, Capitol Reef Nati onal Park, and Zion), in Nevada (Jarbidge Wilderness and Great Basin National Park), at the California-Oregon border (Crater Lake National Park, Lava Beds National Monument, a nd Lassen Volcanic Nationa l Park), and at the Oregon-Washington border (Mount Hood Wilder ness and the Columbia River Gorge). 22

20 See “Emissions Inventory Final Rule TSD,” Technical Support Document (TSD) for the final Transport Rule, Docket ID No. EPA-HQ-OAR-2009-0491, June 28, 2011, at Tables 7-1 and 7-2.

21 The Interagency Monitoring of Protected Visual Environments (IMPROVE) program is a cooperative measurement effort governed by a st eering committee composed of representa tives from Federal and regional-state organizations. The IMPROVE monitoring program was established in 1985 to aid the creation of Federal and State implementation plans for the protection of visibility in class I areas. The objectives of IMPROVE include establishing current aerosol conditions in mandatory class I areas; and identifying chemical species and emission sources responsible for existing man-made visibility impairment. http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx

22 See section V. Appendix to this TSD.12 Ambient PM 2.5 monitoring data, as well as chemical speci es data (ammonium nitrate, ammonium sulfate, elemental carbon, organic carbon, sea sa lt, and soil) is available for each of these monitoring sites. We provide monitored PM 2.5 data from each of these monitoring sites in section V. Appendix to this TSD. The data provided is for the 2009-2013 period for each day

when measurements occurred at these class I mon itors. This provides information about regional background levels of PM 2.5 in the states surrounding Washi ngton, and as discussed below, provides information about levels of PM 2.5 at areas located between Washington and specifically identified nonattainment and maintenance receptors. We note that the chemical composition of

the PM 2.5 in these areas is also avai lable on the IMPROVE website. 23

Most of the elevated levels of PM 2.5 in the western states are meas ured during the winter months. For example, in 2011 and 2012, each exceedance of the 2006 24-hour PM 2.5 NAAQS in Salt Lake City occurred in either December or January of those years. 24 Monitor values are

accessible on the EPA’s AirData website. IMPR OVE monitoring sites evaluated indicate low background PM 2.5 levels during the winter months for each of the years from 2009 through 2013. For example, the PM 2.5 values for January and December of 2010 at Bryce Canyon National Park, Utah are below 3μg/m 3

. See Figure 1 below. While there are variations in the data, including peaks during non-winter mont hs, we believe the data provided in section V. Appendix to this TSD generally indicates that PM 2.5 levels in class I areas, as monitored by the IMPROVE network, are generally low at the times when areas in the west are typically experiencing

elevated 24-hour PM 2.5 levels (winter months).

Figure 1: IMPROVE PM 2.5 Data for Bryce Canyon National Park for the Year 2010

23 http://vista.cira.colo state.edu/TSS/Resu lts/HazePlanning.aspx

24 Monitoring data is accessible on the EPA’s AirData website at http://www.epa.gov/airtrends/values.html 2013 Design Value Report for PM 2.5

.13 In addition, the EPA reviewed technical info rmation, such as meteorological conditions, topography, distance, and monitored ambient data re lated to each of the ar eas with nonattainment and maintenance receptors in the potentially impacted western states to evaluate the factors that

cause or contribute to the elevated PM 2.5 levels at these locations. We discuss our evaluation of the factors with respect to each identified nonattainment and maintenance receptor in the following sections. Please note th at some states contain both id entified nonattainment receptors and maintenance receptors, specifically: Californ ia, Montana, and Utah. Therefore an evaluation for receptors in these states appears in both sections III and IV below.

III. Transport Assessment for Nonattainment Receptors

III.A. Introduction

Based on the methodology for selecting nonattainment receptors described in section II.A above, we evaluated nonattainment receptors in the fo llowing western states: California, Montana, Oregon, and Utah. 25 We have also addressed the nearest eastern receptor evaluated in the Transport Rule modeling domain. 26

III.B. Transport to Western States

III.B.1. California

Eastern California/ Inyo County N onattainment Receptor (Site 060271003)

County Site Name Description

Inyo Keeler This site is affected prim arily is by crustal sources.

Massive erosion from Owens dry lake; in Owens Valley.

The EPA identified a single nonattainment recept or in Inyo County, speci fically the Keeler monitor, which is located adjacen t to the Owens Lake Bed. (See Figures 2 through 4 below).

The Owens Lake Bed is su rrounded by steep terrain.

25 As this analysis focuses on interstate transport, we did not evaluate the impact of Washington emissions on receptors within Washington.

26 Madison County, Illinois. See “Technical Support Document (TSD) for th e final Transport Rule, Docket ID No. EPA-HQ-OAR-2009-0491, June 28, 2011.14 Figure 2: Keeler Dunes 27

The Owens Valley Planning Area (OVPA) is lo cated in Inyo County in eastern-central

California. It is situated at the south end of the deep, long, na rrow Owens Valley with the Sierra Nevada to the west (maximum elevation 14,495 f eet), the Inyo Mountains to the east (maximum elevation 14,246 feet), and the Coso Range to the south (maximum elevation 8,160 feet). The predominantly dry, alkaline Owens Lake bed is approximately eight miles south of the community of Lone Pine on U.S. Highway 395, 60 m iles north of the city of Ridgecrest, and 35 miles west of Death Valley. The bed of Owens Lake is defined as the area below 3,600 feet above mean sea level (all elevations will be give n in feet above mean sea level). The lake bed

extends about seventeen miles north and south and ten miles east and west and covers an area of approximately 110 square miles (70,000 acres).

Owens Lake is the larg est single source of PM 10 in the United States. 28 Water was first diverted from the Owens River to the City of Los Angeles in 1913, and by 1926 Owens Lake was dry. Today, the Owens lakebed produces enormous amounts of windblown dus t in exceedance of federal air pollution standards for particulate matter. Monitoring and research conducted for more than 20 years, as well as three previous State Implementation Plans (SIPs), has determined that wind-blown dust from the dry bed of Owe ns Lake is the dominant cause of NAAQS

27 http://www.gbuapcd.org/owenslake.htm

28 Ibid.15 violations for PM 10 in the area. 29 Based on the above-described information about the proximity of this receptor to the large, eroding dry bed of Owens Lake, the distance from Washington to this receptor ( ≈ 700 miles), and the significant interveni ng terrain, as described above, we

believe it is reasonable to conclude that emissi ons from Washington sources do not significantly

contribute to nonattainment of the 2006 24-hour PM 2.5 NAAQS at this receptor.

Figure 3: Owens Lake Dust ID Network Map

29 Final 2008 Owens Valley PM10 Planning Area Demonstration of Attainment State Implementation Plan, January 28, 2008. http://www.gbuapcd.org/ovpm10sip.htm16 Figure 4: Owens Lake Contour Map17 Southern California/Riverside County Nonatta inment Receptor (Riverside) (Site 060658005)

The high 24-hour PM 2.5 concentrations in the South Coast Air Basin and at the Riverside nonattainment receptor are mainly due to the secondary formation of smaller particulates resulting from mobile, stationary and area sour ce emissions of precursor gases (i.e., NOx, SOx, ammonia (NH 4 ), and VOCs) that are converted to PM in the atmosphere. Speciated PM 2.5 data at the Central Los Angeles Site (CELA) and the Rubi doux site (RIVR) indicate that organic carbon, ammonium nitrate, and ammoni um sulfate constitute the major components at each site . See Figures 5 and 6 below. 24-hour PM 2.5 design value trends show str ong downward trends at all

sites in the South Coast Basin. 30 See Figure 7 below.

Figure 5: Speciated data for the Central Los Angeles Site 31

30 Joe Cassmassi, Scientific, Technical & Modeling Peer Review (STMPR) Advisory Group Meeting, September 22,

2011.

31 STMPR Item # 5 - 2008 PM 2.5 Air Quality Characterization, January 19, 2012. Bong-Mann Kim.18 Figure 6: Speciated data for Roubidoux site at Riverside 32

32 Ibid.19 Figure 7: 24-hour PM 2.5 Design Value Trends

PM 2.5 is essentially a combustion generated polluta nt due to the volume of traffic flow and numbers of sources (both point and area) in the region. It is important to note that the areas with the highest concentrations are directly downw ind of an area with major ammonia sources associated with dairies and poultry farming. 33

The South Coast Air Quality 2012 Air Quality Management Plan 34 air quality projections show that the emission control strategy outlined in the plan will result in air quality improvement at each of the nonattainment receptor s in the plan, and that each of these sites will attain the

standard in 2014 or sooner. See Figure 8 below.

33 Final 2012 Air Quality Management Plan (AQMP), Appendix V – Modeling and Attainment Demonstrations February, 2013.

34 http://www.aqmd.gov/home/l ibrary/clean-air-plans20 Figure 8: Maximum 24-Hour Average PM 2.5 Design Concentrations: 2008 Baseline, 2014,

and 2014 Controlled 35

Based on the air quality trends a nd projections that indicate that the above-referenced emission strategy will be effectiv e in reducing 24-hour PM 2.5 levels at this receptor, the distance from Washington to this receptor ( ≈ 900 miles), and the significant in tervening terrain including the Sierra Nevada ( see Figure 9 below), we believe it is reasonabl e to conclude that emissions from Washington do not significantly contribut e to nonattainment of the 2006 24-hour PM 2.5 NAAQS at the Riverside receptor.

Central California/ Fresno, Kern, Kings, Madera, Merced, San Joaquin, Stanislaus and Tulare Counties Nonattainment Receptors (Sites: see table 2 below)

Table 2: Central California – San Joaquin Valley Nonattainment Receptor Sites

County Nonattainment Receptor Sites Fresno 060190011, 060195001, 060195025 Kern 060290014, 060290016 Kings 060310004, 060311004

Madera 060392010 Merced 060470003, 060472510 San Joaquin 060771002, 060772010 Stanislaus 060990005, 060990006

Tulare 061072002

35 Source: South Coast Air Quality Management District. http://www.aqmd.gov/home /library/clean-air-plans21 PM 2.5 levels in the San Joaquin Valley are generally highest in the months of January, February,

November and December. PM 2.5 builds up in episodes of several days or weeks. See Figure 10 below. These episodes generally occur during pe riods with stagnation, co ol temperatures, high humidity, and low mixing depths. 36 The peak day composition of PM 2.5 at Bakersfield is primarily ammonia nitrate (67 %) and organic carbon (16%). See Figure 11 below.

Figure 9: Map of California 37

36 Nature of PM 2.5 in the San Joaquin Valley, Karen Magliano, California Air Resources Board, Technical Symposium. April 27, 2012.

37 Source: University of Texas. http://www.lib.utexas.edu22 Figure 10: Monthly Average PM 2.5 Concentration in Bakersfield California 38

Figure 11: 2008 – 2010 Peak Day Composition in Bakersfield 39

38 Source: South Coast Air Quality Management District. http://www.aqmd.gov/home /library/clean-air-plans

39 Ibid.23 The primary sources of PM 2.5 in the region are diesel engines (n itrate), gasoline engines (nitrate), and agricultural activities (ammonium) which contribute regionally. Wood smoke (organic carbon) and diesel engines (eleme ntal carbon) contribute to the elevated 24-hour levels of PM 2.5 in urban areas.

Based on the evidence discussed above, that PM 2.5 builds up in episodes of several days or weeks, during periods with stagnation and low mi xing depths, the distance from Washington to these receptors ( ≈ 500 miles), and the significant intervenin g terrain, including the Sierra Nevada Range ( see Figure 9 above), we believe it is reasonabl e to conclude that emissions from Washington do not significan tly contribute to nonattain ment of the 2006 24-hour PM 2.5 NAAQS at these receptors.

California/Mexico Border – Imperial C ounty Nonattainment Receptor (Site 060250005)

Levels of PM 2.5 in Imperial County that exceed the 2006 24-hour PM 2.5 NAAQS are recorded at the Calexico – Ethel Street monitoring site, which is located near the Mexican Border ( see Figure 13 below). The elevated levels of PM 2.5 occur primarily in the wintertime, and seven of the nine values above the level of 35 μg/m 3 in the years 2008-2010 occur in December or January ( See Table 3 below).

Table 3: Calexico-Ethel Street: Dates of PM 2.5 Values Above 35 μg/m 3 (2006 - 2010)

Year Dates 2008 January 4, and December 22, 25 2009 September 4, and December 12, 21, 24 2010 June 28, and December 4

The levels of PM 2.5 measured at the Brawley and El Centro monitoring sites are always lower – usually much lower – than those measured at the Calexico Ethel Street monitor on days when the

PM 2.5 levels at the Calexico Ethe l Street monitor exceed 35 μg/m 3 . See Figures 13 and 14 below. Because these nearby monitors do not show similar increases in monitored values, it appears that

the elevated PM 2.5 is being significantly influenced by a source near the California/Mexico

Border.

Based on the above-described information, distan ce from Washington to this California receptor ( ≈ 1000 miles), and significant in tervening topography, including th e Sierra Nevada Range (see Figure 9 above), we believe it is re asonable to conclude that emissions from Washington do not significantly contribute to nona ttainment of the 24-hour PM 2.5 standard at this receptor.24 Figure 13: PM 2.5 Monitoring Sites in Im perial County California25 Figure 14: PM 2.5 levels (μg/m 3 ) at Imperial PM 2.5 Monitoring Sites, 2006 - 2010, for days of

elevated 24-hour PM 2.5

Northern California – Plumas County Nonattainment Receptor (Site 0600631006)

County Site Description

Plumas Quincy This receptor violated the 2006 24-hour PM 2.5 NAAQS in the most recent design value period (2011-2013) but was in attainment of the

24-hour PM 2.5 NAAQS in the three previous design value periods.

The EPA identified a single nonattainment receptor in Northern California – the Plumas County receptor located in Quincy. While this receptor is located in an area that is designated attainment

for the 2006 24-hour PM 2.5 NAAQS, portions of Plumas County are being considered in the designations process for the 2012 annual PM 2.5 NAAQS. 40 We note that we are not evaluating

40 EPA Technical Support Document for California for the 2012 Primary Annual PM 2.5 NAAQS. http://www.epa.gov/pmdesignations/2012standards/eparesp/09_CA_120TSD_20140818.pdf 0 10 20 30 40 50 60 70 Calexico ‐ Ethel

El Centro

Brawley26 interstate transport requirements for the 2012 annual PM 2.5 NAAQS in this action, however, we believe that the information developed as part of the designations process for the 2012 annual

PM 2.5 NAAQS is informative for our evaluation of this receptor for purposes of interstate transport requirements for the 2006 24-hour PM 2.5 NAAQS. 41

A letter from the Northern Sierra Air Quality Management District, dated June 18, 2014, cites wood burning for residential heating in wood stoves and fireplaces, open burn piles for yard waste disposal, and prescribed burning in near by federal lands performed by the U.S. Forest Service and a railroad switching ya rd as the sources affecting PM 2.5 concentrations in Portola, located in Plumas County, 32 miles from Quincy. 42 Elevated PM 2.5 in the winter months in Portola is generally considered related to emissions from re sidential wood burning. The letter cited the diurnal pattern of PM 2.5 concentrations that peak around the two times people use their wood stoves most: from 5:00 pm to 12:00 am, and from 5:00 am to 8:00 am. With respect to the Quincy receptor, the Northern Sierra Air Qualit y Management District indicated that similar diurnal patterns are found in Quincy, but not to the same degree. The letter stated that “emissions in Quincy are also mainly from wood bur ning appliances (as s upported by diurnal PM 2.5 concentration patterns), alt hough Sierra Pacific Industries maintains a biomass-fired cogeneration facility in Quincy that emitted an 2010-2012 average of 44 tons per year of total particulate matter.” 43

The population of Plumas County is 19,940. 44 The county lies in the northern Sierra Nevada

Mountains near the southern border of the Cas cade Range. The topography of Plumas County is highly variable, including mountain peaks ( ≈ 7,000 ft.) and valleys with extreme slopes and

differences in altitude. 45 This topography affects and directs airflow, causing shallow vertical mixing, and creating areas of high pollutant concentrations by hindering dispersion. 46 Quincy is

located in a small and isolated mountain valley at approximatel y 5000 feet elevation. 47 Prevailing winds in Quincy are from the west, and much of the time there is no measureable wind in Quincy, as indicated by wind roses developed by Northern Sierra Air Quality Management

District. 48

Based on the nature of the PM 2.5 problem in general at this receptor as described above, the distance from Washingt on to this receptor ( ≈ 500 miles), low background levels of PM 2.5 at the time when these exceedances generally occur, 49 and significant interven ing terrain as described

41 EPA Technical Support Document for California for the 2012 Primary Annual PM 2.5 NAAQS. http://www.epa.gov/pmdesignations/2012standards/eparesp/09_CA_120TSD_20140818.pdf

42 2012 Northern Sierra Air Quality Management District letter dated June 18, 2014. http://www.epa.gov/pmdesignations/2012standards/rec/r9carec2.pdf

43 Ibid at page 4.

44 2010 Census.

45 EPA Technical Support Document for California for the 2012 Primary Annual PM 2.5 NAAQS. http://www.epa.gov/pmdesignations/2012standards/eparesp/09_CA_120TSD_20140818.pdf

46 2012 Northern Sierra Air Quality Management District letter dated June 18, 2014. http://www.epa.gov/pmdesignations/2012standards/rec/r9carec2.pdf

47 Ibid. at page 2.

48 Ibid. at Attachment 6, page 13.

49 IMPROVE monitoring data at Jarbidge Wilderness Area, NV, and Lassen Volcanic National Park, CA. See section V. Appendix to this TSD.27 above, we believe it is reasonable to conclude that emissions from Washington do not contribute significantly to nonattainment of the 24-hour PM 2.5 standard at this receptor.

Figure 15: Topographical Map of Plumas County 50

III.B.2 Idaho

Franklin County/Cache County Nonattain ment Receptor (Logan) (Site 490050004)

See discussion of Cache C ounty/Franklin County in section III.B.5. Utah below.

50 EPA Technical Support Document for California for the 2012 Primary Annual PM 2.5 NAAQS. http://www.epa.gov/pmdesignations/2012standards/eparesp/09_CA_120TSD_20140818.pdf28 Shoshone County Nonattainment R eceptor (Pinehurst) (Site 160790017)

The EPA identified a single nonattainment rece ptor in Shoshone County, Idaho, namely the receptor located in Pinehurst. Idaho Department of Environmental Quality identified Pinehurst

as an area of concern for PM 2.5

. 51 A portion of Shoshone County (West Silver Valley) was included as part of the designa tions process for the 2012 annual PM 2.5 NAAQS (80 FR 2206, January 15, 2015). 52 We note that we are not evaluating in terstate transport requirements for the

2012 annual PM 2.5 NAAQS in this action, however, we believe that the information developed as part of the designations process for the 2012 annual PM 2.5 NAAQS is informative for our evaluation of this receptor for purposes of inte rstate transport requirements for the 2006 24-hour

PM 2.5 NAAQS. 53

Shoshone County is a rural county in the northern panhandle of Idaho. The area is sparsely populated and is home to rugged mountainous terra in. Residential wood combustion in the cold, winter months is most responsible for elevated particulate matter in the area, while prescribed burning in the late autumn and in the spring also contributes substantially . Smoke from wildfires

can affect the area in the summer. Smoke from crop residue burning is a minor contributor to

PM 2.5 at this receptor. 54

The Pinehurst monitor measures high values in the winter due to a comb ination of residential wood combustion, low wind speeds, and low mixi ng heights. In the springtime prescribed burning contributes to elevated PM 2.5 . The monitor generally records lower values in the summer except for occasional impacts from wildfires. In the autumn season the monitor is again influenced by prescribed burning. 55

Pinehurst is located in a pa rtially obstructed topographic bowl within the Silver Valley. 56 The Silver Valley is also th e location of the Bunker Hill Superfund site which is a large mining site that has been undergoing remediation since the 1980s. The mining site currently has only minor emissions associated with movement of product from the underground mining sites. The analysis developed for the 2012 annual PM 2.5 NAAQS designations process sup ports a conclusion that the majority of the emissions impacting PM 2.5 levels, in general, are generated from residential wood combustion in close proximity to the Pinehurst m onitor. Secondarily, emi ssions from prescribed burning generated in and around the Silver Valley ar e also expected to co ntribute to elevated

PM 2.5 levels. 57

Topography plays a significant role in channe ling winds along valle ys in particular meteorological situations. See Figure 17 below.

51 https://www.deq.idaho.gov/media/662796-nonattainment_map.pdf

52 EPA Technical Support Document for Idaho for the 2012 Primary Annual PM 2.5 NAAQS. EPA docket # EPAHQ-OAR-2012-0918. http://www.epa.gov/pmdesignations/2012st andards/eparesp/10_ID_120NAATSD.pdf

53 Ibid at page 5.

54 Ibid. at page 5.

55 Ibid. at page 8.

56 Ibid. at page 29.

57 Ibid. at page 29.29 Figure 17: Pinehurst Monitor within West Silver Valley Topography

In West Silver Valley the predominant wind di rections are southweste rly and westerly, but during pollution episodes the wind can also be southerly or northeas terly. During calm, wintertime weather conditions, cold surface temp eratures, low wind speeds, and constrained vertical mixing develop in concert with each other. The deep, narrow mountain valley significantly magnifies this effect relative to other nearby areas. The combination of these meteorological effects and the mountainous terr ain confine the geograp hical area that could contribute emissions to the polluti on episode in West Silver Valle y. It is hypothesized that the particular terrain features around Pinehurst limit mi xing in Pinehurst even more so than the rest of the West Silver Valley. 58

Light westerly winds are often associated with high PM 2.5 at the receptor because the monitor is located on the east side of town. The light west erly winds collect wintertime residential wood

combustion PM 2.5 and carry it to the monitor to the east where it is constrained within the east side of the topographic bowl. At night cold air dr ainage winds follow the stream valleys from the higher terrain around West Silver Valley and into river valley. These winds could bring smoke

58 Ibid. at page 34.30 from smoldering prescribed burns from higher el evation into West Silver Valley. Stronger downvalley northeast winds clear the valley of pollution, while at ot her times weak northeast winds advect pollution to the monitor. 59 During cold stagnant periods when PM 2.5 is the highest, the mountainous terrain strongly limit the ability of the already w eak transport winds to bring pollution from outside areas into the valley. 60

Given the characteristics of the elevated PM 2.5 levels at this receptor, air quality data indicating that regional background levels of PM 2.5 are generally low during the time periods of elevated

PM 2.5 at this receptor 61 and the intervening topography between Washington and this receptor,

we believe it is reasonable to conclude that emissions from Washington sources do not contribute significantly to nonattainment of the 2006 24-hour PM 2.5 NAAQS at this receptor.

Lemhi County Nonattainment Receptor (Salmon) (Site 160590004)

The EPA identified a single nonattainment rece ptor in Lemhi County, Idaho. Lemhi County population is 7,936. The largest city and county seat is Salmon.

The highest point is Bell Mount ain at 11,612 feet above mean sea level (MSL), and the lowest point is the Salmon River at approximately 3,000 feet above MSL. The river cuts through the center of Lemhi County before turning west. Th e county’s eastern border with Beaverhead County, Montana, is the continental divide. See Figure 18 below.

The Salmon area is currently listed by the Idaho De partment of Environmental Quality as an area

of concern for PM 2.5. 62 Information from the State of Ida ho indicates that local emissions, including from woodstoves, contribute to primary PM 2.5 that results in elevated daily PM 2.5 values during stable weather events a ssociated with strong inversions.

The highest values at this receptor were also associated with significant wildfires in 2012. Despite the impacts of wildfire in 2012, Idaho De partment of Environmental Quality recognizes that residential wood burning in combination wi th winter inversions meteorology are impacting the Salmon receptor. The topography of the area is significant. The Salmon receptor is located in a mountain valley surrounding by significant terrai n. The Bitteroot Range, part of the Rocky Mountains, is situated between Washington and th is receptor.

59 Ibid. at page 34.

60 Ibid. at page 36.

61 Craters of the Moon, ID, Sawtooth Na tional Forest, ID, Sula Peak Wilderness Area, MT, Gate of the Mountains Wilderness Area, MT. See section V. Appendix to this TSD and http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx

62 https://www.deq.idaho.gov/media/662796-nonattainment_map.pdf31 Figure 18: Map of Idaho32 Given the characteristics of the elevated PM 2.5 levels at this receptor, air quality data indicating that regional background levels of PM 2.5 are generally low during the time periods of elevated

PM 2.5 at this receptor, 63 and the intervening topography between Washington and this receptor, as described above, we believe it is reasonable to conclude that emi ssions from Washington sources do not contribute significantly to nonattainment of the 2006 24-hour PM 2.5 NAAQS at this receptor.

Ada County Nonattainment Receptor (Boise) (Site 160010010)

Ada County is identified as an area of concern for PM 2.5 by the Idaho Department of Environmental Quality. 64 Ada County is in southwest Ida ho and Boise is the county’s most populace city. This receptor is in the wester n Treasure Valley, a basin with surrounding mountainous topography. The Boise Front, approxi mately 6,000 feet above MSL is located to the north. The Owyhee Mountains are situated to the southwest. Temperature inversions in Ada County occur in the winter months. These stag nation events are cited by Idaho Department of Environmental Quality as impacting the area with respect to particulate matter pollution. 65

Sources of PM 2.5 and precursors are shown in the Table 4 below.

Table 4: Annual Emissions by Source Category—2015 (tons per year) 66

Source Type NOx SO2 VOC PM10 PM2.5 TC

Point 355.6 65.7 268.1 169.1 142.6 68.5 Area 900.0 23.6 14,551.2 21,107.4 3,651.3 7,806.1 On-road 5,856.6 33.4 2,939.7 283.0 193.0 246.0 Non-road 1,979.8 28.2 1,480.7 196.9 185.8 172.7 Biogenic 202.3 0.0 12,802.5 0.0 0.0 0.0 Total 9,294.3 150.9 32,042.2 21,756.4 4,172.7 8,293.3

The design value for the period 2011-2013 at this receptor exceeded the 2006 24-hour PM 2.5 NAAQS, however the previous three design value periods attained the 2006 24-hour PM 2.5 NAAQS. 67 IMPROVE data from the Hells Canyon a nd Starkey class I areas are generally low during the times of elevated 24-hour PM 2.5 levels at the Ada County receptor. 68

Given the characteristics of the elevated PM 2.5 levels at this receptor, air quality data indicating that regional background levels of PM 2.5 are generally low during the time periods of elevated

63 Craters of the Moon, ID, Sawtooth Na tional Forest, ID, Sula Peak Wilderness Area, MT, Gate of the Mountains Wilderness Area, MT. See section V. Appendix to this TSD and http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx

64 https://www.deq.idaho.gov/media/662796-nonattainment_map.pdf

65 See Northern Ada County Carbon Monoxide maintenance Plan and Redesignation Request

66 Source: Idaho Department of Environmental Quality.

67 EPA Airdata.

68 See section V. Appendix to this TSD.33 PM 2.5 at this receptor, 69 and the intervening topography between Washington and this receptor,

we believe it is reasonable to conclude that emissions from Washington sources do not contribute significantly to nonattainment of the 2006 24-hour PM 2.5 NAAQS at this receptor.

III.B.3. Montana

Silver Bow County Nonattainment Receptor (Butte) (Site 300930005)

Elevated levels of PM 2.5 in the Butte area also occur primarily in the winter months. 70 The Butte area is topographically prone to wintertime temperatur e inversions, as it is situated in a mountain valley. The mountains of the Lewis Range a nd the Bitteroot Range, part of the Rocky Mountains, are situated to the west of Butte. See Figure 16 below. The tallest peaks in the Bitteroot Range reach 7,000 to 11,000 feet. Specia tion data indicates that emissions from wood smoke are the primary contributor to exceedances of the PM 2.5 standard in Butte. 71 These factors

indicate that hi gh levels of PM 2.5 in Butte build as emissions become trapped in the mountain valley during wintertime inversions. 72

Given the characteristics of the elevated PM 2.5 levels at this receptor, air quality data indicating that regional background levels of PM 2.5 are generally low during the time periods of elevated

PM 2.5 at this receptor, 73 and the intervening topography between Washington and this receptor, as described above, we believe it is reasonable to conclude that emi ssions from Washington sources do not contribute significantly to nonattainment of the 2006 24-hour PM 2.5 NAAQS at this receptor.

69 Craters of the Moon, ID, Sawtooth Na tional Forest, ID, Sula Peak Wilderness Area, MT, Gate of the Mountains Wilderness Area, MT. See section V. Appendix to this TSD and http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx

70 In 2009 and 2010, the only recent years in wh ich the Butte maintenance r eceptor violated the 2006 PM 2.5 NAAQS, each exceedance of the NAAQS occurred in either December or January. M onitor values are accessible on EPA’s AirData website, http://www.epa.gov/airquality/airdata/

. 71 Ward, T., Lange, T., “The impact of wood smoke on ambient PM 2.5 in northern Rocky Mountain valley communities.” Environmental Pollution 158 (2010) 723–729.

72 Ibid.

73 Craters of the Moon, ID, Sawtooth Na tional Forest, ID, Sula Peak Wilderness Area, MT, Gate of the Mountains Wilderness Area, MT. See section V. Appendix to this TSD and http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx34 Figure 16: Map of Montana 74

III.B.4. Oregon

Crook County Nonattainment Receptor (Site 410130100)

Crook County is located in central Oregon and th e city of Prineville is the county seat - population 9,253. 75 The Cascade Range borders on the west of the region, with high desert to the

east and the Ochoco Mountains to th e northeast. Prineville is marked with a blue triangle near the center of the state as depicted in Figure 17 below.

74 Source: University of Texas. http://www.lib.utexas.edu

75 2010 Census.35 Figure 17: Map of Oregon – Prin eville, Klamath Falls, Lakeview 76

Within Central Oregon, Crook County has a high rate of residential wood burning. 77 PM 2.5 speciation data is not available for th e Prineville receptor, but daily mean PM 2.5 concentration

time series between 2009 and 2013 show that the hi ghest values have typically occurred in the winter months of December and January, indica ting an association with residential wood burning and wintertime inversion meteorology. See Figure 18 below.

76 Source: www.lib.utexas.edu

77 See Oregon 2005 Residential Wood Combustion Emission Inventory , Oregon Department of Environmental Quality.36 Figure 18: Prineville, Oregon Daily Mean PM 2.5 Concentrations

In addition, PM 2.5 levels at IMPROVE monitors in betw een Washington and this receptor are generally low during the winter months (< 5 μg/m 3 ) when exceedances at th e Prineville receptor have typically occurred. 78 The topography of the Cascade Mountains also separates Western Washington (the most significant area of emissions) and this receptor.

Based on the nature of the PM 2.5 problems at this receptor as described above, the distance of this receptor from Washington (approximately 100 miles), low background levels at IMPROVE

monitors in the class I areas between this r eceptor and Washington when wintertime inversionrelated exceedances of the NAAQS generally occur, 79 and the significant terrain between Washington population centers and th is receptor as described above , we believe it is reasonable to conclude that emissions from Washington do not contribute significantly to nonattainment of

the 2006 24-hour PM 2.5 NAAQS at this receptor.

78 IMPROVE monitoring network at Mount Hood Wilderness, OR and Columbia River Gorge, OR. See section V. Appendix to this TSD and http://vista.cira.colostate.ed u/TSS/Results/HazePlanning.aspx

79 Ibid.37 Klamath County Nonattainment Recepto r (Klamath Falls) (Site 410350004)

A portion of Klamath County is desi gnated nonattainment for the 2006 PM 2.5 NAAQS. 80 Klamath Falls is a relatively small urban commun ity located in and suppo rting a vast rural area in south-central Oregon, near the California border. See Figure 17 above. The community lies in a valley at the northern end of the Klamath basin, a broad valley surrounded by mountains. Klamath Falls is at an elevation of approximately 4500 ft. above mean sea level (MSL). Surrounding mountains rise to 5000-6000 ft. MS L. A 2005 emission inventory conducted by Oregon shows that wood stove emissions are the most significant source of emissions. 81

Additional air quality monitoring data provid e supporting evidence that residential wood combustion emissions are a primary contributor to exceedance days. 82 Data shows exceedances occur during winter months, at a time when woods toves are contributing to smoke in the area. Exceedances occurred from December through Ja nuary, corresponding directly with the winter wood heating season and indicate the exceedances are a seasonal occurrence, except flagged

wildfire events. 83

Speciation data analysis indicates most of the PM 2.5 comes from elemental and organic carbon, typical indicators of combustion activities such as wood burning. 84 Meteorological data from Klamath Falls show that low wind speeds dominat e during violating days, and the Klamath Falls area experiences frequent winter-time nocturnal inversions, when PM pollution can build up over

time. Diurnal concentrations of PM 2.5 are observed by hourly light s catter data that correspond closely with night-time use of woodstoves. Ni ght-time inversions coupled with low wind speeds strongly suggest that pollution in the Klamath Falls area builds when trapped by winter, nighttime inversions. EPA R10 factor analysis m odeling identified the fo llowing 5 categories of aerosol contributing to PM 2.5 : Nitrate Rich, Organic Pyrolysi s Rich, Soil, Sulfate Rich, Wood Smoke. EPA R10’s analysis of average factor c ontributions on winter seas on days with elevated

PM 2.5 shows Wood Smoke dominating at 72%.

Based on the above-described information, dist ance from Washington to this receptor ( ≈ 240 miles), low background levels at IM PROVE monitors in class I area s near this receptor at the

time of elevated PM 2.5 , 85 and significant interven ing terrain (as discussed above), we believe it is reasonable to conclude that Washington emi ssions do not significantly contribute to

nonattainment of the 2006 24-hour PM 2.5 NAAQS at this receptor.

80 Technical Support Document, Oregon Area Designations for the 24-Hour Fine Particle National Ambient Air Quality Standards http://www.epa.gov/pmdesignations/2006standards/final/TSD/tsd_4.0_4.10_4.10.3_r10_OR.pdf

81 Ibid.

82 Ibid.

83 Ibid.

84 Ibid.

85 IMPROVE monitoring network at Three Sisters Wild erness, OR and Crater La ke National Park, OR. See V. Appendix to this TSD and http://vista.cira.colostate.ed u/TSS/Results/HazePlanning.aspx38 Lake County Nonattainment Receptor (Lakeview) (Site 410370001)

As seen in Figure 17 above, Lakeview, Oregon is located to the east of Klamath Falls, and is the county seat of Lake County, population 2,294. 86 Lakeview is located in the Goose Lake Valley

at the foot of the Warner Mountains to the east. Lakeview is on the edge of the high desert country of southeastern Oregon. At an elevation of 4,800 feet ( 1,500 m), Lakeview is one of the highest cities in Oregon. 87 The significant topography between Western Washington (the most significant emission sources) and this receptor in cludes over 250 miles of the Cascade Range.

EPA R10 factor analysis modeling identified the following 7 categories of aerosol contributing

to PM 2.5 : Nitrate Rich, Organic Pyrolysis Rich, Potassium Rich, Soil, Sulfate Rich, Urban Unidentified, and Wood Smoke. EPA R10’s analysis of average factor c ontributions on winter season days with elevated PM 2.5 shows Wood Smoke dominating at 67%.

Based on the nature of the PM 2.5 problem in Lakeview described above, low background levels at

IMPROVE monitors in class I areas near this receptor dur ing the winter months when exceedances typically occur, 88 distance from Washington to this receptor (approximately 250 miles), and significant intervening terrain as de scribed above, we believe it is reasonable to conclude that Washington emissi ons do not significantly contribut e to nonattainment of the 2006

24-hour PM 2.5 NAAQS at this receptor.

Lane County Nonattainment Receptor (Oakridge) (Site 410392013)

A portion of Lane County is designated nonattainment for the 2006 PM 2.5 NAAQS (Oakridge NAA). 89 Elevated levels at the Oakridge nonattai nment receptor generally occur during winter stagnation events and the technical analysis developed during the desi gnations process by the State of Oregon and the EPA point s to residential home heati ng using wood burning appliances, as being the main contributor to fi ne particle pollution in the area. 90 The EPA Region 10 factor analysis modeling identified the following se ven categories of aeros ol contributing to PM 2.5 : Gasoline Vehicles, Organic Pyrolysis Rich, Sea Sa lt, Soil, Sulfate Rich, Urban Unidentified, and Wood Smoke. EPA Region 10’s analysis of average factor contributions on winter season days

with elevated PM 2.5 shows Wood Smoke dominating at 72%.

Oakridge, Oregon is a small, isolated mountai n community 35-40 miles east of Eugene, Oregon, surrounded by national forest. It is located in Lane County, whic h stretches from the Pacific Ocean to the mountains of the Cascade Range. Vast areas of Lane County are forested mountains of the Coast Range and Cascade Range. 91 Oakridge lies in an alluvial plain in the foothills at the

86 2010 Census.

87 Oregon topographic map , United States Geological Survey, United States Department of Interior, Reston, Virginia; displayed via ACME mapper, www.acme.com , 19 July 2014.

88 Crater Lake, OR, Lava Beds National Monument, CA, and Starkey, ID. See V. Appendix to this TSD and http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx

89 2006 24-Hour PM 2.5 NAAQS Designations (November 13, 2009; 74 FR 58688).

90 Technical Support Document, Oregon Area Designations for the 24-Hour Fine Particle National Ambient Air Quality Standards http://www.epa.gov/pmdesignations/2006standards/final/TSD/tsd_4.0_4.10_4.10.3_r10_OR.pdf

91 Ibid.39 southern end of the Willamette River valley and is 28 miles west of Willamette Pass, the summit of the Cascade Mountain Range (approximately 5000 feet in elevation). Elevation in the area ranges from 1100 feet at the lower (west) end to 1600 feet with areas of densest population

situated between 1100 feet and 1200 feet. 92 Mountains rise on the nor th and south sides to 1700 feet and 1600 feet, respectively. 93 There is significant topog raphy between Washington and Oakridge, Oregon including the Ca scade Range as depicted in Figure 17 above. This terrain reaches up to 5000 feet at the summit of Willamette Pass.

Based on the above information, the distan ce of this receptor from Washington ( ≈ 150 miles), low background levels at IMPROVE monitors in the class I areas between this receptor and Washington 94 when wintertime inversion-related exceed ances of the NAAQS generally occur, and the significant terrain between Washington and this receptor as described above, we believe

it is reasonable to conclude that emissions fr om Washington do not cont ribute significantly to

nonattainment of the 2006 24-hour PM 2.5 NAAQS at this receptor.

92 Ibid.

93 Ibid.

94 IMPROVE monitoring network at Mount Hood Wilderness, OR

, Columbia River Gorge, OR, and Three Sisters Wilderness, OR

. See section V. Appendix to this TSD and http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx40 III.B.5. Utah

Utah County Nonattainment Receptors (Provo) (Sites 490490002, 490494001, 490495008, 490495008)

A large portion of Utah County is designated as the Provo 2006 24-hour PM 2.5 nonattainment area (Provo NAA). 95 The Provo nonattainment receptors iden tified are situated in the Utah Valley. Like the other low-lying valleys just west of the Wasa tch Front, the topography of the Utah Valley makes it prone to temperature inversions. See Figure 19 below. The Wasatch Mountain Range rises from the valley floor to approximately 7,000 to over 9,000 ft. MSL and

defines the eastern boundaries of both the Salt La ke Valley to the north and the Utah Valley to the south. These valleys are bound on their resp ective western sides by the Oquirrh Mountains which also have heights of 7,000 ft. MSL to we ll over 9,000 ft. MSL. North of Salt Lake County, the Wasatch Mountain Range continues to act as a barrier to the east, while the Great Salt Lake serves as the western boundary. 96

Elevated levels of PM 2.5 at these receptors occur prim arily in the winter months. 97 The levels of

elevated PM 2.5 at these receptors are driven by inversi on meteorology which traps pollutants and leads to exceedances, as noted in th e discussion of these receptors below. 98 During the winter months, levels of PM 2.5 at background monitoring sites locate d north and west of this receptor 99 are very low, generally below 3μg/m 3 , and the vast majority of the PM 2.5 in the urban area is generated within the area and trapped during winter invers ion meteorology.

95 2006 24-Hour PM 2.5 NAAQS Designations (74 FR 58688, November 13, 2009), Technical Support Document,
December 2008. http://www.epa.gov/pmdesignations/2006standard s/final/TSD/tsd_4.0_4.8_4.8.2_r08_UT.pdf

. 96 Ibid. at page 48.

97 For example, in 2011 and 2012, each exceedance of the 2006 PM 2.5 NAAQS in Salt Lake City occurred in either December or January of those years. Monitor va lues are accessible on EPA’s AirData website, http://www.epa.gov/airquality/airdata/

. 98 2006 24-Hour PM 2.5 NAAQS Designations (74 FR 58688, November 13, 2009), Technical Support Document,

December 2008. http://www.epa.gov/pmdesignations/2006standard s/final/TSD/tsd_4.0_4.8_4.8.2_r08_UT.pdf . At page 48.

99 IMPROVE monitoring network at Craters of the Moon, ID, Sawtooth National Forest, ID and Jarbidge Wilderness Area, NV. See section V. Appendix to this TSD and http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx41 Figure 19: Monitoring Network with Counties and Topography 100

During inversions, the Provo NAA features stagnant air masses and calm to light winds. As the airshed is essentially capped, PM 2.5 is formed in-situ (and trapped) via fresh emission sources and

100 Source: Utah Department of Environmental Quality. 2006 24-Hour PM 2.5 NAAQS Designations (74 FR 58688, November 13, 2009), Technical Support Document, December 2008. http://www.epa.gov/pmdesignations/2006standards/final/TSD/tsd_4.0_4.8_4.8.2_r08_UT.pdf . at page 19.42 secondary chemistry. Transport of air masses be tween Salt Lake City and Provo receptors can occur during inversions, as ther e is a 4.75-mile gap in the mount ains separating these airsheds which is below the approximate averag e inversion height for these areas. 101

Speciation data from wintertime PM 2.5 exceedance days from 2004-2006 showed the average composition of PM 2.5 in Provo is 71% ammonium nitrat e, with 21% carbon and organic compounds, 8% ammonium sulfate, and 2% crusta l. Several factors, including significant amounts of emissions from mobile, point and area s ources, contribute to primary and secondarily

formed PM 2.5 that violate the 2006 24-hour PM 2.5 NAAQS during stable weather events associated with strong inversions. 102

Based on the meteorology, topography and characteristics of the PM 2.5 levels during time periods

when the 24-hour PM 2.5 standard is exceeded as described above, as well as the low levels of background PM 2.5 during these time periods at IMPROV E monitors in the class I areas between Washington and these receptors or near these receptors 103 it is reasonable to conclude that emissions from Washington do not significantly c ontribute to nonattainme nt of the 2006 24-hour

PM 2.5 NAAQS at these receptors.

Box Elder, Salt Lake and Weber Counties Nonatt ainment Receptors (Gre ater Salt Lake City) (Sites 490030003, 490350003, 490353006, 490353010, 490570002)

All of Salt Lake county and portions of Box Elde r and Weber counties are designated as part of the Salt Lake City (SLC) 2006 24-hour PM 2.5 nonattainment area (NAA). 104 The EPA identified nonattainment receptors in each of the three counties. The SLC NAA and these nonattainment receptors are situated in a valley borde red on the west by the Stansbury Mountains, 105 Promontory Mountains and Great Salt Lake, and on the east by the Wasatch Front. Like the other low-lying valleys just west of the Wasatc h Front, the topography of the Salt Lake valley makes it prone to temperature inversions. See Figure 19 above.

A western topographic airshed barrier for easte rn Box Elder County involves the Promontory Mountains and North Promontory Mountains. 106 The Promontory Mountains are located approximately 24 miles west of both Brigham City and Ogden and show approximate altitudes of 5,600 ft. (MSL) in the south (extending into the Great Salt Lake), areas of over 6,000 ft. (MSL) in the middle, and 5,000 ft. to the North where they meet the southern end of the North

101 Ibid. at page 41.

102 Ibid. at page 34.

103 IMPROVE monitoring network at Jarbidge Wilderness Area, NV, Crater Lake, OR, and Lava Beds National Monument, CA. See section V. Appendix to this TSD and http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx

104 2006 24-Hour PM 2.5 NAAQS Designations (74 FR 58688, November 13, 2009), Technical Support Document,
December 2008. http://www.epa.gov/pmdesignations/2006standard s/final/TSD/tsd_4.0_4.8_4.8.2_r08_UT.pdf . At page 25.

105 The Quqirrh Mountains lie between the Wasatch Front an d the Stansbury Mountains. However, EPA determined that some area located west of the Quqirrh Mountains should still be considered part of the SLC nonattainment area.

106 2006 24-Hour PM 2.5 NAAQS Designations (74 FR 58688, November 13, 2009), Technical Support Document,

December 2008. http://www.epa.gov/pmdesignations/2006standard s/final/TSD/tsd_4.0_4.8_4.8.2_r08_UT.pdf . At page 48.43 Promontory Mountains. The southern end of the North Promontory Mountains are approximately 5,000 ft. (MSL) and are also approximately 5,000 ft. (MSL) to the north (northwest of Howell, UT.) 107

The Stansbury Mountains are located approxi mately 17 miles west of Tooele City (approximately 43 miles southwest of Salt Lake City) and show approximate altitudes of 8,300 ft. (MSL) in the south, areas 7,000 ft. (MSL) to over 9,500 ft. (MSL) in the middle, and 5,000 ft. (MSL) to the North where they meet the Great Salt Lake. Also, an impediment to airflow in this

area includes the South Mountain ri dge located at the southern e nd of the Tooele Valley. This ridge essentially connects the Stansbury Mount ains to the Oquirrh Mountains and has a maximum height of approximately 6,500 ft. (MSL). Therefore, it is likely that Salt Lake County is contributing to Utah C ounty’s high concentration PM 2.5 violations and that Utah County is contributing to Salt Lake County’s high concentration PM 2.5 violations. 108

During inversions, the SLC NAA becomes a closed airshed (save for potential transport between the Salt Lake City and Provo NAAs) featuring stagnant air masses and light winds which typically oscillate back and forth within the airshed. As the airshed is essentially capped during inversions, PM 2.5 is formed in-situ (and trapped) via fresh emission sources and secondary chemistry. 109 Speciation data from wintertime PM 2.5 exceedance days from 2004-2006 showed the average composition of PM 2.5 in Salt Lake City is 58% a mmonium nitrate, 31% carbon and organic compounds, 8% ammonium sulfate, and 2% crustal. Several factors, including significant amounts of emissions from mobile, point and area sources, cont ribute to primary and secondarily formed PM 2.5 that violate the 2006 24-hour PM 2.5 standard during stable weather events associated with strong inversions. 110

Based on the meteorology, topography and characteristics of the PM 2.5 levels during time periods

when the 24-hour PM 2.5 standard is exceeded, as described ab ove, as well as the low levels of background PM 2.5 during these time periods at IMPROVE mo nitors at class I areas near this
receptor 111 it is reasonable to conclude that emi ssions from Washington do not significantly

contribute to nonattainment of the 2006 24-hour PM 2.5 NAAQS at these receptors.

Cache County/ Franklin County Nonatta inment Receptor (Logan) (Site 490050004)

Portions of Cache County, Utah and Franklin County, Idaho make up the Cache Valley, a mountain valley straddling the Utah-Idaho border. Portions of these two counties are also designated as part of the Logan UT-ID 2006 24-hour PM 2.5 , cross-state nonattainment area (Cache Valley NAA). 112 See Figure 20 below.

107 Ibid. at page 48.

108 Ibid. at page 49.

109 Ibid. at page 34.

110 Ibid. at page 53.

111 IMPROVE monitoring network at Jarbidge Wilderness Area, NV, Crater Lake, OR, and Lava Beds National Monument, CA. See section V. Appendix to this TSD and http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx

112 2006 24-Hour PM 2.5 NAAQS Designations (74 FR 58688, November 13, 2009), Technical Support Document,

December 2008. http://www.epa.gov/pmdesignations/2006standard s/final/TSD/tsd_4.0_4.8_4.8.2_r08_UT.pdf . At page 2.44 Figure 20: Location map showing the Cach e Valley and the boundaries for Franklin County, Idaho, and Cache County, Utah. 113

Limited chemical speciation data indicates the 24-hour PM 2.5 problem is dominated by

ammonium nitrate aerosol similar to nonattainment areas along the Wasatch Front in and near

113 Source Utah Department of Environmental Quality.45 Salt Lake City. 114 The chemical speciation monitor in B ountiful is closest to the Cache Valley and is considered broadly representa tive of conditions in the Cache Valley. 115 The ridge dominated synoptic meteorology during PM 2.5 cold pool episodes features weak transport winds and near calm surface winds. As a result, transport of PM 2.5 and precursors from the rural regions at the domain periphery is limited. In addition, most of the observed Wasatch Front and Cache Valley PM 2.5 is formed in-situ (and trapped) via fresh emission sources and secondary chemistry. 116

Residential heating emissions from woodstoves, emissions from agricultural activities, and

mobile source emissions contribute to primary and secondarily formed PM 2.5 that violate the 24- hour standard during stable weat her events associated with ex tremely strong inversions. These

emissions and the related effects are limited to th e Cache Valley, as they are trapped there due to temperature inversions, low wind, and significant topography. 117

The most prominent topographical features imp acting the Cache Valley as a whole include: (1) the eastern boundary of the valley which is composed of the Wa satch-Cache National Forest, the Bear River Mountain Range, and Monte Cristo Mountain Range, and (2) the western boundary which is composed of the northern section of the Wasatch Mountain Range and the Wellsville Mountain Range. The mountains to the east rise to approximately 8,300 feet MSL and to the

west the mountains rise to a pproximately 9,900 feet MSL. However, the valley floor only ranges in altitude from approximately 4,500 feet MS L to 5,200 feet MSL from south to north respectively. 118

The Wellsville Mountains, Bear River Mountains , and northern Wasatch mountains converge in southern Cache County, Utah to form a topogra phical barrier between the Cache Valley and other adjacent Utah counties such as Box Elder and Weber. As w ith the southern area of the Cache Valley, the mountain ranges of the north ern area of the Cache Valley, bordering the eastern and western portions of Franklin County, effectively meteorologically isolate Franklin County from Bannock, Bear Lake, Cari bou, and Oneida Counties in Idaho. 119

EPA Region 10 Positive Matrix Factor (PMF) receptor modeling identified 11 factors contributing to elevat ed wintertime 24-hour PM 2.5 levels at the Bountif ul monitoring site including nitrate rich (56%), am monium chloride (15%), wood smoke (10%), organic pyrolysis rich (6%), sulfate rich (5%) and smaller cont ributions by other identif ied factors (gasoline vehicles, two soil factors, fireworks, iron rich, and urban unidentified).

Based on the meteorology, topography and characteristics of the PM 2.5 levels during time periods

when the 24-hour PM 2.5 standard is exceeded, as described ab ove, as well as the low levels of background PM 2.5 during these time periods at IMPROVE mo nitors at class I areas near this

114 2006 24-Hour PM 2.5 NAAQS Designations (74 FR 58688, November 13, 2009), Technical Support Document,
December 2008. http://www.epa.gov/pmdesignations/2006standard s/final/TSD/tsd_4.0_4.8_4.8.2_r08_UT.pdf . At page 9.

115 Ibid. at page 14-15.

116 Ibid. at page 14-15.

117 Ibid. at page 17-18.

118 Ibid. at page 17-18.

119 Ibid. at page 7.46 receptor 120 it is reasonable to conclude that emi ssions from Washington do not significantly

contribute to nonattainment of the 2006 24-hour PM 2.5 NAAQS at this receptor.

III.C. Transport to Eastern States

The EPA has also considered potential PM 2.5 transport from Washington emission sources to the nearest potential receptor located in the easter n, midwestern, and southern states within the domain of the modeling analysis for the Transpor t Rule (76 FR 48208). The receptor nearest to Washington evaluated in the Transport Rule mode ling analysis is Madison County, Illinois. We note, the Transport Rule modeling did not anal yze the contribution of Washington sources to Madison County, Illinois. Thus, we have analyzed the magnitude of Washington’s SO 2 and NOx

emissions relative to states found to have emissions that significantly cont ribute to nonattainment at that receptor. The EPA also considered the distance from Washi ngton to Madison County,

Illinois relative to stat es found to significantly contribute there.

We believe that the following factors support a finding that emissions fr om Washington sources do not significantly contribute to nonattainment of the 2006 24-hour PM 2.5 NAAQS at the Madison County, Illinois receptor: (1) the relativ ely small magnitude of the emission inventory

of PM 2.5 precursors (SO 2 and NOx) in Washington as detailed below, combined with (2) the relatively long distance between the Stat e of Washington and this receptor ( ≈ 1400 miles). The EPA believes that these factors also support a fi nding that emissions fr om Washington sources do not significantly contribute to nonattainment of the 2006 24-hour PM 2.5 NAAQS at any of the other Transport Rule re ceptors farther east.

In the Transport Rule analysis , the EPA did not quantify the PM 2.5 contributions from Washington to Illinois or any of the other Ea stern nonattainment and maintenance receptors modeled as part of the Transport Rule. However, we can make a qualitative conclusion about the likely contribution from Washington to Illin ois and points farther east by comparing the Washington emissions to a stat e that was modeled in the Tr ansport Rule. Minnesota was modeled for the Transport Rule, and was found belo w the threshold of significant contribution to

downwind nonattainment and interference with maintenance of the 24-hour PM 2.5 NAAQS for all receptors modeled for the Transport Rule. We have evaluated the relative amounts of PM 2.5 precursor (SO 2 and NOx) emissions in Washington compared to the amounts of PM 2.5 precursor emission in Minnesota, as modeled in th e “2012 Transport Rule Base Case.”

The emission inventories used in the Trans port Rule modeling analysis indicate that SO 2 emissions in Washington are about 35% of SO 2 emissions in Minnesota and NOx emissions in Washington are about 74% of NOx emissions in Minnesota. Specifically, the Transport Rule

2012 Base Case inventories 121 provide the following statewide em issions inventory data for these two states: 38,581 tons of SO 2 and 268,870 tons of NOx from Washington emission sources, compared to 109,940 tons of SO 2 and 364,052 tons of NOx from Minnesota emission sources. Even though the relationship between upw ind emissions and downwind secondary PM 2.5

120 IMPROVE monitoring network at Jarbidge Wilderness Area, NV, Crater Lake, OR, and Lava Beds National Monument, CA. See section V. Appendix to this TSD and http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx

121 See “Emissions Inventory Final Rule TSD,” Technical Support Document (TSD) for the final Transport Rule, Docket ID No. EPA-HQ-OAR-2009-0491, June 28, 2011, at Tables 7-1 and 7-2.47 formation is not linear, we would expect the Washington PM 2.5 contribution to Il linois to be less
than that of Minnesota and well below the 1% thre shold applied in the initial screening stage of the Transport Rule. In addition, Washington is a much greater distance away from Madison County, Illinois than Minnesota ( ≈ 1400 miles vs approximately 300 miles). The distance from Washington to the other eastern re ceptors is even greater, and th erefore, the expected impact

somewhat smaller.

Given all of these factors, the EPA believes it is reasonable to conclude that emissions from Washington sources do not cont ribute significantly to nonattainment of the 2006 24-hour PM 2.5 NAAQS at identified receptor s in any eastern state.

IV. Transport Assessment for Maintenance Receptors

IV.A. Introduction

Based on our methodology for selecting ma intenance receptors described in section II.A above, we have evaluated maintenance receptors in th e following western states : California, Montana,

and Utah. We also evaluated the nearest easte rn receptor evaluated in the Transport Rule modeling domain. 122

IV.B. Transport to Western States

IV.B.1. California

Southern California –Los Angeles Count y Maintenance Receptor (Site 060370002)

The high 24-hour PM 2.5 concentrations in the South Coast Air Basin and at this maintenance receptor are mainly due to the secondary formation of smaller particulates resulting from mobile, stationary and area source em issions of precursor gases (i.e., NOx, SOx, ammonia (NH 4 ), and VOCs) that are converted to PM in the atmosphere. Speciated PM 2.5 data at the Central Los Angeles Site (CELA) and the R ubidoux site (RIVR) indicate th at organic carbon, ammonium nitrate, and ammonium su lfate constitute the majo r components at each site . See Figures 20 and

21 below. 24-hour PM 2.5 design value trends show strong down ward trends at all sites in the

South Coast Basin. 123 See Figure 22 below.

122 Madison County, Illinois. See “Technical Support Document (TSD) for th e final Transport Rule, Docket ID No. EPA-HQ-OAR-2009-0491, June 28, 2011.

123 Joe Cassmassi, Scientific, Technical & Modeling Peer Review (STMPR) Advisory Group Meeting, September 22, 2011.48 Figure 21: Speciated data for the Central Los Angeles Site 124

124 STMPR Item # 5 - 2008 PM2.5 Air Quality Characterization, January 19, 2012. Bong-Mann Kim.49 Figure 22: Speciated data for Roubidoux site at Riverside 125

125 Ibid.50 Figure 23: 24-hour PM 2.5 Design Value Trends

PM 2.5 is essentially a combustion generated polluta nt due to the volume of traffic flow and numbers of sources (both point and area) in the region. It is important to note that the areas with the highest concentrations are directly downw ind of an area with major ammonia sources associated with dairies and poultry farming. 126

The South Coast Air Quality 2012 Air Quality Management Plan 127 air quality projections show that the emission control strategy outlined in the plan will result in air quality improvement at each of the nonattainment receptor s in the plan, and that each of these sites will attain the

standard in 2014 or sooner. See Figure 24: Maximum 24-Hour Average PM 2.5 Design Concentrations: 2008 Baseline, 2014 and 2014 Controlled

.

126 Final 2012 Air Quality Management Plan (AQMP), Appendix V – Modeling and Attainment Demonstrations February, 2013.

127 http://www.aqmd.gov/home/li brary/clean-air-plans51 Figure 24: Maximum 24-Hour Average PM 2.5 Design Concentrations: 2008 Baseline, 2014,

and 2014 Controlled 128

Based on the air quality trends a nd projections that indicate that the above-referenced emission strategy will be effectiv e in reducing 24-hour PM 2.5 levels at these receptors, the distance from Washington to these receptors ( > 800 miles), and the significant intervening terrain including the Sierra Nevada and Cascade Ranges ( See Figure 9 above) we believe it is reasonable to conclude that emissions from Washington do not interfere with maintena nce of the 2006 24-hour

PM 2.5 NAAQS at these receptors.

IV.B.2. Montana

Lewis and Clark County Maintenanc e Receptor (Helena) (Site 300490026)

Elevated levels of PM 2.5 in the Helena area occur primarily in the winter months. 129 The Helena Valley is topographically prone to cold pool inversion conditions during the winter months. 130 The mountains of the Lewis Range and the Bitteroot Range are situated to the west of Helena, between Washington and this receptor. See Figure 25 below. Speciation data indicates that emissions from wood smoke are the primary contributor to exceedances of the PM 2.5 standard in

Helena. 131 In the months when violations of the NAAQS occurred at the Helena receptor, the

128 Source: South Coast Air Quality Management District. http://www.aqmd.gov/home /library/clean-air-plans

129 The maintenance receptor in He lena, MT violated the 2006 PM 2.5 NAAQS only in 2010. Each of the exceedances

of the 2006 PM 2.5 standard at this receptor during 2010 occurred during the winter months, with all but one exceedance occurring in December or January. M onitor values are accessible on EPA’s AirData website, http://www.epa.gov/airquality/airdata/

. 130 Johnson, J. “Case Study of a Persistent Cold Pool in the Helena Valley.” NOAA. November 21, 2000.

131 Ward, T., Lange, T., “The impact of wood smoke on ambient PM 2.5 in northern Rocky Mountain valley communities.” Environmental Pollution 158 (2010) 723–729.52 nearby Gate of the Mountains Wilder ness Area monitor did not exceed 2 μg/m 3

. 132 All of these factors taken together indi cate that high levels of PM 2.5 in Helena build as emissions become trapped during wintertime inversions.

Figure 25: Map of Montana 133

Given the characteristics of the elevated PM 2.5 levels at this receptor, air quality data indicating that regional background levels of PM 2.5 are generally low at IMPR OVE monitors in class I areas near this receptor 134 during the time periods of elevated PM 2.5 , and the intervening topography between Washington and this receptor (the Bitteroot Range, part of the Rocky Mountains) we believe it is reasonable to conc lude that emissions from Washington sources do

not interfere with maintenance of the 2006 24-hour PM 2.5 standards at this receptor location.

IV.B.3. Utah

Davis and Weber Counties Maintenance Recepto rs (Greater Salt Lake City) (Sites 490110004 and 490571003)

We note that the EPA identified both nonattainment and maintenance receptors in Greater Salt Lake City. Therefore, we have incl uded our evaluation in both sections.

132 The Gate of the Mountains IMRPOVE monitor is locat ed roughly 17 miles from Helena, MT. The IMPROVE

monitor data can be found in section V. Appendix to this TSD and http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx

133 Source: University of Texas. http://www.lib.utexas.edu

134 Craters of the Moon, ID, Sawtooth Na tional Forest, ID, Sula Peak Wilderness Area, MT, Gate of the Mountains Wilderness Area, MT. See section V. Appendix to this TSD and http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx53 Portions of Davis and Weber c ounties are designated as part of the Salt Lake City (SLC) 2006

24-hour PM 2.5 nonattainment area (NAA). 135 The EPA identified maintenance receptors in these

two counties. The SLC NAA and these maintenance receptors are situated in a valley bordered on the west by the Stansbury Mountains, 136 Promontory Mountains and Great Salt Lake, and on the east by the Wasatch Front. Like the other low-lying valleys ju st west of the Wasatch Front, the topography of the Salt Lake valley makes it prone to temperature inversions. See Figure 26
below.

A western topographic airshed barrier for eastern Davis C ounty involves the Promontory Mountains and North Promontory Mountains. 137 The Promontory Mountains are located approximately 24 miles west of both Brigham City and Ogden and show approximate altitudes of 5,600 ft. (MSL) in the south (extending into the Great Salt Lake), areas of over 6,000 ft. (MSL) in the middle, and 5,000 ft. to the North where they meet the southern end of the North Promontory Mountains. The southern end of the North Promontory Mountains are approximately 5,000 ft. (MSL) and are also approximately 5,000 ft. (MSL) to the north (northwest of Howell, UT.) 138

The Stansbury Mountains are located approxi mately 17 miles west of Tooele City (approximately 43 miles southwest of Salt Lake City) and show approximate altitudes of 8,300 ft. (MSL) in the south, areas 7,000 ft. (MSL) to over 9,500 ft. (MSL) in the middle, and 5,000 ft. (MSL) to the North where they meet the Great Salt Lake. Also, an impediment to airflow in this

area includes the South Mountain ri dge located at the southern e nd of the Tooele Valley. This ridge essentially connects the Stansbury Mount ains to the Oquirrh Mountains and has a maximum height of approximately 6,500 ft. (MSL). Therefore, it is likely that Salt Lake County is contributing to Utah C ounty’s high concentration PM 2.5 violations and that Utah County is contributing to Salt Lake County’s high concentration PM 2.5 violations. 139

During inversions, the SLC NAA becomes a closed airshed (save for potential transport between the Salt Lake City and Provo NAAs) featuring stagnant air masses and light winds which typically oscillate back and forth within the airshed. As the airshed is essentially capped during inversions, PM 2.5 is formed in-situ (and trapped) via fresh emission sources and secondary chemistry. 140 Speciation data from wintertime PM 2.5 exceedance days from 2004-2006 showed the average composition of PM 2.5 in Salt Lake City is 58% a mmonium nitrate, 31% carbon and organic compounds, 8% ammonium sulfate, and 2% crustal. Several factors, including significant amounts of emissions from mobile, point and area sources, cont ribute to primary and

135 2006 24-Hour PM 2.5 NAAQS Designations (74 FR 58688, November 13, 2009), Technical Support Document,

December 2008. http://www.epa.gov/pmdesignations/2006standard s/final/TSD/tsd_4.0_4.8_4.8.2_r08_UT.pdf

. 136 The Quqirrh Mountains lie between the Wasatch Front an d the Stansbury Mountains. However, EPA determined that some area located west of the Quqirrh Mountains should still be considered part of the SLC nonattainment area.

137 2006 24-Hour PM 2.5 NAAQS Designations (74 FR 58688, November 13, 2009), Technical Support Document,

December 2008. http://www.epa.gov/pmdesignations/2006standard s/final/TSD/tsd_4.0_4.8_4.8.2_r08_UT.pdf

. at page 48.

138 Ibid. at page 48.

139 Ibid. at page 49.

140 Ibid. at page 34.54 secondarily formed PM 2.5 that violate the 2006 24-hour PM 2.5 standard during stable weather events associated with strong inversions. 141

Figure 26: Monitoring Network with Counties and Topography 142

141 Ibid. at page 53.

142 Source: Utah Department of Environmental Quality. 2006 24-Hour PM 2.5 NAAQS Designations (74 FR 58688, November 13, 2009), Technical Support Document, December 2008. http://www.epa.gov/pmdesignations/2006standards/final/TSD/tsd_4.0_4.8_4.8.2_r08_UT.pdf . At page 19.55 Based on the meteorology, topography and characteristics of the PM 2.5 levels during time periods

when the 24-hour PM 2.5 standard is exceeded, as described ab ove, as well as the low levels of background PM 2.5 during these time periods at IMPROVE mo nitors at class I areas near this
receptor 143 we believe it is reasonable to conclude that emissions from Washington do not

interfere with maintena nce of the 2006 24-hour PM 2.5 NAAQS at these receptors.

IV.C. Transport to Eastern States

The EPA has also considered potential PM 2.5 transport from Washington emission sources to the nearest potential receptor located in the easter n, midwestern, and southern states within the domain of the modeling analysis for the Transpor t Rule (76 FR 48208). The receptor nearest to Washington evaluated in the Transport Rule mode ling analysis is Madison County, Illinois. We note, the Transport Rule modeling did not anal yze the contribution of Washington sources to Madison County, Illinois. Thus, we have analyzed the magnitude of Washington’s SO 2 and NOx

emissions relative to states found to have emissions that significantly cont ribute to nonattainment at that receptor. The EPA also considered the distance from Washi ngton to Madison County,

Illinois relative to stat es found to significantly contribute there.

We believe that the following factors support a finding that emissions fr om Washington sources

do not interfere with maintenance of the 2006 24-hour PM 2.5 NAAQS at the Madison County, Illinois receptor: (1) the relatively small magnitude of the emission inventory of PM 2.5 precursors (SO 2 and NOx) in Washington as detailed in the paragraph below, combined with (2) the relatively long distance between the stat e of Washington and this receptor ( ≈ 1500 miles). The EPA believes that these factors also support a fi nding that emissions fr om Washington sources

do not interfere with maintenance of the 2006 24-hour PM 2.5 NAAQS at any of the other Transport Rule receptors farther east.

In the Transport Rule analysis , the EPA did not quantify the PM 2.5 contributions from Washington to Illinois or any of the other Easter n receptors modeled as part of the Transport Rule. However, we can make a qualitative conclusion about the li kely contribution from Washington to Illinois and points farther east by co mparing the Washington emissions to a state that was modeled in the Transport Rule. Minn esota was modeled for the Transport Rule, and was found below the threshold of significan t contribution to downwind nonattainment and

interference with maintenance of the 24-hour PM 2.5 NAAQS for all receptors modeled for the Transport Rule. We have evaluated the relative amounts of PM 2.5 precursor (SO 2 and NOx) emissions in Washington comp ared to the amounts of PM 2.5 precursor emission in Minnesota, as modeled in the “2012 Transport Rule Base Case.”

The emission inventories used in the Trans port Rule modeling analysis indicate that SO 2 emissions in Washington are about 35% of SO 2 emissions in Minnesota and NOx emissions in Washington are about 74% of NOx emissions in Minnesota. Specifically, the Transport Rule

143 IMPROVE monitoring network at Craters of the Moon, ID, Sawtooth National Forest, ID and Jarbidge Wilderness Area, NV. See section V. Appendix to this TSD and http://vista.cira.colo state.edu/TSS/Results/HazePlanning.aspx56 2012 Base Case inventories 144 provide the following statewide em issions inventory data for these two states: 38,581 tons of SO 2 and 268,870 tons of NOx from Washington emission sources, compared to 109,940 tons of SO 2 and 364,052 tons of NOx from Minnesota emission sources. Even though the relationship between upw ind emissions and downwind secondary PM 2.5 formation is not linear, we would expect the Washington PM 2.5 contribution to Il linois to be less
than that of Minnesota and below the 1% threshol d applied in the initial screening stage of the Transport Rule. In addition, Washington is a mu ch greater distance away from Madison County, Illinois than Minnesota ( ≈ 1500 miles vs approximately 300 miles). The distance from Washington to the other eastern re ceptors is even greater, and th erefore, the expected impact

somewhat smaller.

Given all of these factors, the EPA believes it is reasonable to conclude that emissions from Washington sources do not interfere w ith maintenance of the 2006 24-hour PM 2.5 NAAQS at identified receptors in any eastern state.

V. Appendix – PM 2.5 IMPROVE Data

1. Overview and Map of IMPROVE Monitoring Sites

IMPROVE Monitoring Program Overview

The Interagency Monitoring of Protected Visu al Environments (IMP ROVE) program is a cooperative measurement effort governed by a st eering committee composed of representatives from Federal and regional-state organizat ions. The IMPROVE monitoring program was

established in 1985 to aid the creation of Federal and State implementation plans for the protection of visibility in class I areas (156 national parks and wild erness areas) as stipulated in

the 1977 amendments to the Clean Air Act. 145

The objectives of IMPROVE include: (1) establishing current visibili ty and aerosol conditions in mandatory class I areas; and (2) identifying chemical species and emission sources responsible for existing man-made visibility impairment.

The particulate monitoring portion of the IMPROVE program measures the concentration of the fine (PM 2.5 ) particles for mass, optical absorption, major and tr ace elements, organic and elemental carbon, and nitrate and of PM 10 particles for mass. Prior to 2000, IMPROVE sites collect two samples per week, on Wednesday and Saturday. With the implementation of the Regional Haze Rule the IMPROVE program changed to a 1-in-3 day schedule.

IMPROVE Monitoring Data

144 See “Emissions Inventory Final Rule TSD,” Technical Support Document (TSD) for the final Transport Rule, Docket ID No. EPA-HQ-OAR-2009-0491, June 28, 2011, at Tables 7-1 and 7-2.

145 http://vista.cira.colostate.edu/improve/Overview/IMPROVEProgram_files/frame.htm57 The data for this report was obtained from the website http://views.cira.colostate.edu/web/ . The graphs in this report show the PM 2.5 (fine) mass monitor values from 2009 to 2013 at selected IMPROVE monitoring locations.

Additional data, such as the chemical compositi on data in the graph shown below, is also

available as the http://views.cira.colostate.edu/web/ site, using the composition tool.

State National Parks, Monume nts and Wilderness Areas (identifier on IMPROVE Network Map)

Idaho (and Idaho/Oregon Border) Craters of the Moon National Monument (69), Sawtooth Wilderness (70), Hells Canyon Wild erness (77), Starkey (76)

Montana Sula Peak (71), Cabinet Mountai ns Wilderness Area (75), Gate of the Mountains Wilderness Area (74)

Nevada Jarbidge Wilderness Area (68), Great Basin National Park (116)

Utah Bryce Canyon National Park (51) , Canyonlands (50), Capitol Reef National Park (52), Zion (49) Wyoming Bridger Wilderness (65), North Absaroka Wilderness Area (67), Yellowstone National Park 2 (66) California-Oregon Border Crater Lake (86), Lava Beds National Monument (87), Lassen Volcanic National Park (90) Oregon/Washington Border Mount Hood ( 85) , Columbia River Gorge (112)

Source: http://vista.cira.colostate.edu/impr ove/Overview/IMPROVENetworkExp.htm5859 

### 2. Idaho and Idaho/Oregon Border – IMPROVE Data for the Years 2009-

2013

Craters of the Moon National Monument, ID

Sawtooth Wilderness, ID60 Hells Canyon Wilderness, ID

Starkey, OR61 

### 3. Montana - IMPROVE Data for the Years 2009-2013

Sula Peak, MT

Cabinets Mountains Wilderness, MT62 Gates of the Mountains Wilderness, MT



### 4. Nevada- IMPROVE Data for the Years 2009-2013

Jarbidge Wilderness, NV63 Great Basin National Park, NV



### 5. Utah – IMPROVE Data for the Years 2009-2013

Bryce Canyon National Park, UT64 Canyonlands National Park, UT

Capitol Reef National Park, UT65 Zion Canyon, UT



### 6. Wyoming - IMPROVE Data for the Years 2009-2013

Bridger Wilderness, WY66 North Absaroka Wilderness, WY



### Yellowstone National Park 2, WY67 

### 7. California/Oregon Border – IM PROVE Data for the Years 2009-2013

Crater Lake National Park, OR

Lava Beds National Monument, CA68 Lassen Volcanic National Park, CA



### 8. Oregon/Washington Border – IM PROVE Data for the Years 2009-2013

Mount Hood Wilderness, OR69 Columbia River Gorge, OR