85 FR 193 pgs. 62679-62686 - Air Plan Approval; ID; 2010 Sulfur Dioxide NAAQS Infrastructure Requirements
Type: PRORULEVolume: 85Number: 193Pages: 62679 - 62686
Pages: 62679, 62680, 62681, 62682, 62683, 62684, 62685, 62686Docket number: [EPA–R10–OAR–2016–0001; FRL–10014–83–Region 10]
FR document: [FR Doc. 2020–21741 Filed 10–2–20; 8:45 am]
Agency: Environmental Protection Agency
Official PDF Version: PDF Version
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R10-OAR-2016-0001; FRL-10014-83-Region 10]
Air Plan Approval; ID; 2010 Sulfur Dioxide NAAQS Infrastructure Requirements
AGENCY:
Environmental Protection Agency (EPA).
ACTION:
Proposed rule.
SUMMARY:
[top] The Environmental Protection Agency (EPA) is proposing to approve a State Implementation Plan (SIP) submission from the State of Idaho (Idaho or the State) that addresses the
DATES:
Written comments must be received on or before November 4, 2020.
ADDRESSES:
Submit your comments, identified by Docket ID No. EPA-R10-OAR-2016-0001 at https://www.regulations.gov. Follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from Regulations.gov. The EPA may publish any comment received to its public docket. Do not electronically submit any information you consider to be Confidential Business Information (CBI) or other information the disclosure of which is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission ( i.e., on the web, cloud, or other file sharing system). For additional submission methods, the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.
FOR FURTHER INFORMATION CONTACT:
Claudia Vaupel at (206) 553-6121, or vaupel.claudia@epa.gov.
SUPPLEMENTARY INFORMATION:
Throughout this document whenever "we," "us," or "our" is used, it is intended to refer to the EPA.
Table of Contents:
I. Background
II. Relevant Factors To Evaluate 2010 SO 2 Interstate Transport SIPs
III. State Submission and EPA Analysis
A. State Submission
B. EPA Analysis
1. The EPA's Prong 1 Evaluation
2. The EPA's Prong 2 Evaluation
IV. Proposed Action
V. Statutory and Executive Order Reviews
I. Background
On June 2, 2010, the EPA established a new primary 1-hour SO 2 NAAQS of 75 parts per billion (ppb), based on a 3-year average of the annual 99th percentile of 1-hour daily maximum concentrations. 1 The CAA requires states to submit, within 3 years after promulgation of a new or revised NAAQS, SIPs meeting the applicable "infrastructure" elements of sections 110(a)(1) and (2). One of these applicable infrastructure elements, CAA section 110(a)(2)(D)(i), requires SIPs to contain "good neighbor" provisions to prohibit certain adverse air quality effects on neighboring states due to interstate transport of pollution.
Footnotes:
1 ?75 FR 35520 (June 22, 2010).
CAA section 110(a)(2)(D)(i) includes four distinct components, commonly referred to as "prongs," that must be addressed in infrastructure SIP submissions. The first two prongs, which are codified in CAA section 110(a)(2)(D)(i)(I), require SIPs to contain adequate provisions that prohibit any source or other type of emissions activity in one state from contributing significantly to nonattainment of the NAAQS in another state (prong 1) and from interfering with maintenance of the NAAQS in another state (prong 2). The third and fourth prongs, which are codified in CAA section 110(a)(2)(D)(i)(II), require SIPs to contain adequate provisions that prohibit emissions activity in one state from interfering with measures required to prevent significant deterioration of air quality in another state (prong 3) or from interfering with measures to protect visibility in another state (prong 4).
In this action, the EPA is proposing to approve the prong 1 and prong 2 portions of the State of Idaho's December 24, 2015 SIP submission because, based on the information available at the time of this rulemaking, the State demonstrated that Idaho will not contribute significantly to nonattainment or interfere with maintenance of the 2010 SO 2 NAAQS in any other state or the Fort Hall Reservation. All other applicable infrastructure SIP requirements for this SIP submission have been addressed in separate actions. See 79 FR 46707 (August 11, 2014).
II. Relevant Factors To Evaluate 2010 SO 2 Interstate Transport SIPs
Although SO 2 is emitted from a similar universe of point and nonpoint sources, interstate transport of SO 2 is unlike the transport of fine particulate matter (PM 2.5 ) or ozone, in that SO 2 is not a regional pollutant and does not commonly contribute to widespread nonattainment over a large (and often multi-state) area. The transport of SO 2 is more analogous to the transport of lead (Pb) because its physical properties result in localized pollutant impacts very near the emissions source. However, ambient concentrations of SO 2 do not decrease as quickly with distance from the source as Pb because of the physical properties and typical release heights of SO 2 . Emissions of SO 2 travel farther and have wider ranging impacts than emissions of Pb but do not travel far enough to be treated in a manner similar to ozone or PM 2.5 . The approaches that the EPA has adopted for ozone or PM 2.5 transport are too regionally focused and the approach for Pb transport is too tightly circumscribed to the source to serve as a model for SO 2 transport. SO 2 transport is therefore a unique case and requires a different approach.
In this proposed rulemaking, as in prior SO 2 transport analyses, the EPA focuses on a 50 km-wide zone because the physical properties of SO 2 result in relatively localized pollutant impacts near an emissions source that drop off with distance. Given the physical properties of SO 2 , the EPA selected the "urban scale"-a spatial scale with dimensions from 4 to 50 kilometers (km) from point sources-given the usefulness of that range in assessing trends in both area-wide air quality and the effectiveness of large-scale pollution control strategies at such point sources. 2 As such, the EPA utilized an assessment up to 50 km from point sources in order to assess trends in area-wide air quality that might impact downwind states.
Footnotes:
2 ?For the definition of spatial scales for SO 2 , see 40 CFR part 58, appendix D, section 4.4 ("Sulfur Dioxide (SO 2 ) Design Criteria"). For further discussion on how the EPA is applying these definitions with respect to interstate transport of SO 2 , see the EPA's proposal on Connecticut's SO 2 transport SIP. 82 FR 21351, 21352, 21354 (May 8, 2017).
As discussed in section III of this this document, the EPA reviewed Idaho's analysis to assess how it evaluated SO 2 transport to other states, the types of information used in the analysis and the conclusions drawn. The EPA then conducted a weight of evidence analysis, reviewing the submission and other available information, including air quality monitor data, emission sources and emission trends within Idaho and in bordering states to which it could potentially contribute or interfere with attainment or maintenance of the 2010 SO 2 NAAQS. 3
Footnotes:
3 ?This proposed approval action is based on the information contained in the administrative record for this action and does not prejudge any other future EPA action that may make other determinations regarding any of the subject state's air quality status. Any such future actions, such as area designations under any NAAQS, will be based on their own administrative records and the EPA's analyses of information that becomes available at those times. Future available information may include, and is not limited to, monitoring data and modeling analyses conducted pursuant to the Data Requirements Rule for the 2010 1-Hour SO 2 NAAQS (80 FR 51052, August 21, 2015) and information submitted to the EPA by states, air agencies, and third party stakeholders such as citizen groups and industry representatives.
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III. State Submission and EPA Analysis
On December 24, 2015, Idaho submitted a SIP revision to the EPA documenting that its SIP contains provisions that address CAA section 110(a)(2)(D)(i)(I) interstate transport requirements for the 2010 SO 2 NAAQS. In this section, we provide an overview of Idaho's 2010 SO 2 interstate transport analysis, as well as the EPA's evaluation of prongs 1 and 2.
A. State Submission
Idaho conducted a weight of evidence analysis to examine whether SO 2 emissions from Idaho will adversely affect attainment or maintenance of the 2010 SO 2 NAAQS in downwind states. In the submission, Idaho identified one 2010 SO 2 nonattainment area in Billings, Montana, within Yellowstone County, which has since been redesignated to attainment. 4 Idaho reviewed 2014 SO 2 emissions data from the largest SO 2 emissions sources in the State and determined that emissions from those sources were hundreds of miles from the SO 2 nonattainment/maintenance areas. Idaho also reviewed 2012-2014 monitoring data from the 3 SO 2 monitoring sites in its monitoring network and from the 14 SO 2 monitoring sites in neighboring states for years 2011-2013. Idaho determined that all design values were below the 2010 SO 2 NAAQS. 5 In addition, Idaho provided 2009-2011 regional-scale modeling for the State and found that areas of increased SO 2 concentrations were localized in nature.
Footnotes:
4 ?The Billings, Montana 2010 SO 2 nonattainment area was redesignated to attainment on May 10, 2016 following the state's SIP submission (81 FR 28718).
5 ?The design value is the annual 99th percentile of the daily maximum 1-hour concentration values, averaged over three consecutive years. (See 75 FR 35520, June 22, 2010).
Based on the weight of evidence analysis, Idaho concluded that emissions within the State will not contribute significantly to nonattainment or interfere with maintenance of the 2010 1-hour SO 2 NAAQS in any other state.
B. EPA Analysis
The EPA proposes to find that Idaho's SIP meets the interstate transport requirements of CAA section 110(a)(2)(D)(i)(I), prong 1 for the 2010 SO 2 NAAQS. We have analyzed the air quality, emission sources and emission trends in Idaho and neighboring states, i.e., Montana, Nevada, Oregon, Utah, Washington, Wyoming, and the Fort Hall Reservation. Based on our analysis, we propose to find that Idaho will not contribute significantly to nonattainment of the 2010 SO 2 NAAQS in any other state or the Fort Hall Reservation.
1. The EPA's Prong 1 Evaluation
The EPA reviewed SO 2 emission data from 2005 to 2017 for Idaho and the six neighboring states. 6 As shown in Table 1 of this document, SO 2 emissions from Idaho and neighboring states have decreased substantially over time, ranging from 37 to 89 percent. Specifically, over this 13-year period, Idaho's statewide SO 2 emissions decreased by 72 percent.
Footnotes:
6 ?We derived the emissions trends information from the EPA's web page https://www.epa.gov/air-emissions-inventories/air-pollutant-emissions-trends-data.
| State | 2005 | 2008 | 2011 | 2014 | 2017 | SO 2 reduction, 2005-2017 (%) |
|---|---|---|---|---|---|---|
| Idaho | 35,452 | 20,149 | 13,791 | 10,062 | 10,007 | 72 |
| Montana | 42,085 | 29,354 | 29,452 | 25,046 | 18,580 | 56 |
| Nevada | 72,474 | 20,951 | 13,578 | 16,178 | 7,793 | 89 |
| Oregon | 37,204 | 25,671 | 30,285 | 23,606 | 19,325 | 48 |
| Utah | 52,999 | 31,609 | 27,839 | 26,964 | 15,442 | 71 |
| Washington | 59,651 | 34,826 | 30,492 | 38,973 | 37,488 | 37 |
| Wyoming | 122,454 | 112,791 | 83,256.1 | 56,772 | 52,354 | 57 |
We also reviewed the most recent certified air quality data available for 1-hour SO 2 design value concentrations at monitors in Idaho and neighboring states. In Table 2 of this document, we have included the most recent 2017-2019 design values for (1) all monitors in Idaho; (2) the monitor with the highest design value in each neighboring state; and (3) the monitor in each neighboring state located closest to the Idaho border. The EPA notes that no neighboring state has an SO 2 monitor within 50 km of the Idaho border. To assess how air quality has changed over time, we also reviewed 2014-2016, 2015-2017, and 2016-2018 SO 2 design values for these monitors, as shown in Table 2.
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| State/area | AQS site ID | Distance to nearest Idaho border (km)?* | Design value | 2014-2016 | 2015-2017 | 2016-2018 | 2017-2019 |
|---|---|---|---|---|---|---|---|
| Idaho/Boise | 160010010 | 55 | 4 | 3 | 3 | 3 | |
| Idaho/Pocatello | 160050004 | 102 | 39 | 38 | 38 | 40 | |
| Idaho/Caribou County | 160290031 | 45 | 26 | 30 | 31 | 35 | |
| Montana/Helena | 300490004 | 180 | 2 | 3 | 5 | 5 | |
| Montana/Billings | 301110066 | 256 | 53 | 33 | 24 | 24 | |
| Nevada/Las Vegas | 320030540 | 644 | 7 | 6 | 6 | 5 | |
| Nevada/Reno | 320310016 | 362 | 5 | 5 | 5 | 4 | |
| Oregon/Portland | 410510080 | 447 | 3 | 3 | 3 | 3 | |
| Washington/Anacortes | 530570011 | 412 | 5 | 4 | 3 | 3 | |
| Wyoming/Casper | 560252601 | 393 | 25 | 20 | 19 | 19 | |
| Wyoming/Rock Springs | 560370300 | 108 | 21 | 21 | 20 | 12 | |
| *?All distances throughout this notice are approximations. | |||||||
We reviewed ambient air quality data in Idaho and neighboring states to see whether there were any monitoring sites, particularly near the Idaho border, with elevated SO 2 concentrations that might warrant further investigation with respect to interstate transport of SO 2 from emission sources near any given monitor. As shown in Table 2 of this document, there are no monitors with violating design values in Idaho or neighboring states. Additionally, the highest monitored 2017-2019 design value in Idaho or neighboring states is 40 ppb, or approximately 54 percent of the level of the 2010 SO 2 NAAQS.
Footnotes:
7 ?Design values are from monitors with sufficient data available in the EPA's Air Quality System (AQS) to produce valid design values. Data retrieved from the EPA's https://www.epa.gov/air-trends/air-quality-design-values#report.
As discussed previously, Idaho analyzed potential impacts to the Billings, Montana area, which was still designated nonattainment at the time of Idaho's submission. The EPA redesignated the former Billings 2010 SO 2 nonattainment area to attainment following the permanent closure of the PPL Corette Plant. See 81 FR 28718 (May 10, 2016). As noted by Idaho, the Billings, Montana area is located far from the nearest Idaho border (256 km). Table 2 of this document also shows that recent monitoring data in the Billings area do not approach the level of the 2010 SO 2 NAAQS. For these reasons, the EPA agrees with Idaho's conclusion that the emissions from Idaho will not contribute significantly to nonattainment in the Billings, Montana area.
The data presented in Table 2 of this document show that 2017-2019 1-hour SO 2 design values in Idaho are between 4 and 54 percent of the 75-ppb level of the NAAQS. The Caribou County SO 2 monitor (AQS Site ID 160290031) is the only Idaho SO 2 monitor that is located within 50 km of a state border-the Idaho-Wyoming border. The 2017-2019 design value at the Caribou County SO 2 monitor is 35 ppb or 47% of the NAAQS. However, these air quality data do not, by themselves, indicate any particular location that would warrant further investigation with respect to SO 2 emission sources in Idaho that might contribute significantly to nonattainment in the bordering states. Because the monitoring network is not necessarily designed to find all locations of high SO 2 concentrations, this observation indicates an absence of evidence of impact at these locations but is not sufficient evidence by itself of an absence of impact at all locations in the neighboring states. We have therefore also conducted a source-oriented analysis.
As noted, the EPA finds that it is appropriate to examine the impacts of emissions from stationary sources in Idaho in distances ranging from 0 km to 50 km from the facility, based on the "urban scale" definition contained in appendix D to 40 CFR part 58, section 4.4. Therefore, we assessed Idaho and neighboring state point sources that emit 100 tons per year (tpy) of SO 2 ? 8 or more that are located up to 50 km from an Idaho border.
Footnotes:
8 ?We have limited our analysis to sources emitting at least 100 tpy of SO 2 because in the absence of special factors, for example the presence of a nearby larger source or unusual physical factors, Idaho sources emitting less than 100 tpy can appropriately be presumed to not be causing or contributing to SO 2 concentrations above the NAAQS.
There are four sources in Idaho that emit 100 tpy of SO 2 or more. These sources are located in southeastern Idaho and are listed in Table 3 of this document. Two of the sources, P4 Production and Itafos Conda, are less than 50 km from the Idaho-Wyoming border, 45 km and 40 km, respectively.
| Idaho SO 2 Source | 2017 Emissions (tpy)? 9 | Distance to nearest state border (km)/state border |
|---|---|---|
| J.R. Simplot Company-Don Siding Pocatello (Pocatello, ID) | 748 | 101/ID-NV. |
| The Amalgamated Sugar Company (Twin Falls, ID) | 635 | 61/ID-NV. |
| P4 Production (Soda Springs, ID) | 488 | 45/ID-WY. |
| Itafos Conda (Conda, ID) | 387 | 40/ID-WY. |
[top] The Naughton Generating Plant in Lincoln, Wyoming, is the closest neighboring state source to P4 Production and Itafos Conda. The EPA has therefore assessed potential SO 2 impacts from these Idaho sources to the Lincoln, Wyoming area. Table 4 of this document shows SO 2 emissions and approximate distances between the sources. The EPA finds that the 131 to 134 km distance between the two Idaho sources and the Wyoming source, more than twice the 50-km distance the EPA has focused on for this analysis, makes it very unlikely that SO 2 emissions from
Footnotes:
9 ?Point source emissions data throughout this document were obtained through the EPA's Emissions Inventory System (EIS) Gateway at https://www.epa.gov/air-emissions-inventories/emissions-inventory-system-eis-gateway.
10 ?In round 3 of 2010 SO 2 designations, the EPA designated Lincoln County in Wyoming as attainment/unclassifiable for the 2010 1-hour SO 2 NAAQS based on modeling of the Naughton source area. See "Technical Support Document: Chapter 45 Final Round 3 Area Designations for the 2010 1-Hour SO 2 Primary National Ambient Air Quality Standard for Wyoming" at https://www.epa.gov/sites/production/files/2017-12/documents/45-wy-so2-rd3-final.pdf. See also "Technical Support Document: Chapter 45 Intended Round 3 Area Designations for the 2010 1-Hour SO 2 Primary National Ambient Air Quality Standard for Wyoming" at https://www.epa.gov/sites/production/files/2017-08/documents/45_wy_so2_rd3-final.pdf.
| Idaho SO 2 source | 2017 SO 2 emissions (tpy) | Distance to nearest neighboring state SO 2 source (km)/source | Neighboring state source 2017 SO 2 emissions (tpy) |
|---|---|---|---|
| Itafos Conda (Conda, Idaho) | 387 | 134/Naughton Generating Plant, Lincoln, WY | 4,048 |
| P4 Production (Soda Springs, Idaho) | 488 | 131/Naughton Generating Plant, Lincoln, WY | 4,048 |
The EPA also reviewed the location of neighboring state sources that emit 100 tpy of SO 2 or more and are located within 50 km of the Idaho border. This is because SO 2 emitted by sources in Idaho are most likely to impact elevated levels of SO 2 in neighboring states near such sources. As shown in Table 5 of this document, there are two sources in neighboring states that are located within 50 km of an Idaho border, the previously mentioned Naughton Generating Plant in Lincoln, Wyoming, located in southeastern Idaho, and EP Minerals in Vale, Oregon, located in southwestern Idaho. The shortest distance between any pair of these sources is 131 km, between the Naughton Generating Plant and P4 Production. As just explained, this distance makes it unlikely that SO 2 emissions from the Idaho source will interact with SO 2 emissions from the Wyoming source. This indicates that there is no location in any neighboring state that would warrant further investigation with respect to Idaho SO 2 emission sources that might contribute to problems with attainment of the 2010 SO 2 NAAQS.
| Neighboring state SO 2 source | 2017 SO 2 emissions (tpy) | Distance to Idaho border (km) | Distance to nearest Idaho SO 2 source (km) | Idaho Source 2017 SO 2 Emissions (tpy) |
|---|---|---|---|---|
| Naughton Generating Station, Lincoln, WY | 4,048 | 46 | 131 (P4 Production, Soda Springs, ID) | 488 |
| EP Minerals, Vale, OR | 182 | 32 | 286/The Amalgamated Sugar Company, Twin Falls, ID | 635 |
The Fort Hall Reservation
On January 19, 2017, the EPA determined that the Shoshone-Bannock Tribes of the Fort Hall Reservation were eligible to be treated in the same manner as an affected downwind state for purposes of CAA sections 110(a)(2)(D) and 126. 11 Idaho submitted the SO 2 interstate transport SIP before this determination and the submission did not analyze SO 2 transport to the Fort Hall Reservation. Therefore, the EPA has conducted the following weight of evidence analysis for potential Idaho SO 2 transport to the Fort Hall Reservation.
Footnotes:
11 ?The EPA's determination that the Shoshone-Bannock Tribes are eligible for treatment in the same manner as a state for CAA sections 110(a)(2)(D) and 126 is available in the docket for this action. See also https://www.epa.gov/tribal/tribes-approved-treatment-state-tas.
The Fort Hall Reservation is located in southeastern Idaho, mostly on the high, flat, cultivated east banks of the Snake River Plain which average around 4,500 feet above sea level. The east portion of the Reservation rests on the northern reaches of the Pocatello range of mountains. The Fort Hall Reservation is bordered on the east and south by the rugged rocky hills of the Pocatello, Chesterfield, and Caribou mountain ranges. These ranges run north-south with peaks rising from 6,000 to 9,000 feet above sea level, generally east and south of the Reservation.
[top] The EPA reviewed ambient air quality data, particularly near the Fort Hall Reservation borders, for any monitoring sites with elevated SO 2 concentrations that might warrant further investigation with respect to interstate transport of SO 2 from Idaho sources. The nearest SO 2 monitor to the Fort Hall Reservation is in Pocatello, Idaho (AQS Site ID 160050004) and is approximately 2 km from the nearest Reservation border. Another SO 2 monitor is located in Caribou County, Idaho (AQS Site ID 160290031) and is approximately 37 km from the southeastern border of the Fort Hall Reservation. Although these monitors are not sited to determine maximum impacts at the Fort Hall Reservation, monitoring data listed in Table 6 of this document, indicate that SO 2 levels in those areas are relatively low. The 2017-2019 design values at the Pocatello and Caribou County monitor
| AQS monitor location (AQS site ID) | Approximate distance to Fort Hall Reservation (km) | Design value | 2012-2014 | 2013-2015 | 2014-2016 | 2015-2017 | 2016-2018 | 2017-2019 |
|---|---|---|---|---|---|---|---|---|
| Pocatello (160050004) | 2 | 51 | 41 | 39 | 38 | 38 | 40 | |
| Caribou County (160290031) | 37 | 30 | 26 | 26 | 30 | 31 | 35 |
These air quality data do not, by themselves, indicate any particular location that would warrant further investigation with respect to SO 2 emission sources that might contribute significantly to nonattainment at the Fort Hall Reservation. However, data from this monitoring network is not necessarily representative of SO 2 levels throughout the Fort Hall Reservation and we have therefore also conducted a source-oriented analysis.
Footnotes:
12 ?Design values are from monitors with sufficient data available in the EPA's Air Quality System (AQS) to produce valid design values. Data retrieved from https://www.epa.gov/air-trends/air-quality-design-values#report.
As discussed previously, the EPA finds that it is appropriate to examine the impacts of emissions from stationary sources in Idaho in distances ranging from 0 km to 50 km from the facility, based on the "urban scale" definition contained in appendix D to 40 CFR part 58, section 4.4. Therefore, we assessed point sources with SO 2 emissions of 100 tpy? 13 or more within 50 km of the Fort Hall Reservation to evaluate trends and SO 2 concentrations in areawide air quality. We identified three such sources, listed in Table 7 of this document. We note that there are no sources within the Fort Hall Reservation that emit more than 2 tpy of SO 2 .
Footnotes:
13 ?We have limited our analysis to Idaho sources emitting at least 100 tpy of SO 2 because in the absence of special factors, for example the presence of a nearby larger source or unusual physical factors, Idaho sources emitting less than 100 tpy can appropriately be presumed to not be causing or contributing to SO 2 concentrations above the NAAQS.
| SO 2 Source? 14?15 | 2017 SO 2 emissions (tpy) | Distance to Fort Hall Reservation (km) | Distance to Pocatello site (AQS site ID 160050004) | Distance to Caribou County site (AQS Site ID 160290031) |
|---|---|---|---|---|
| J.R. Simplot Company-Don Siding Pocatello (Pocatello, ID) | 748 | <1 | 1 | 80 |
| P4 Production (Soda Springs, ID) | 488 | 38 | 80 | 1 |
| Itafos Conda (Conda, ID) | 387 | 38 | 82 | 7 |
J.R. Simplot Company-Don Siding Pocatello
Footnotes:
14 ?The Simplot Don Siding Plant, P4 Production, and Itafos Conda are title V major stationary sources subject to the applicable limits and controls in the Idaho SIP, including Idaho's SIP-approved stationary source Permit to Construct program (IDAPA 58.01.01.200 through 222). The Simplot Don Siding Plant is owned or operated by J.R. Simplot Company, which is a party to a Federal Consent Decree to resolve CAA violations at the company's sulfuric acid plants. (Consent Decree, USA et al. v. J.R. Simplot Company, Case No. 1:15-cv-00562-CWD (Dist. Idaho 2015). On August 19, 2019, the Idaho Department of Environmental Quality issued a revised Permit to Construct to incorporate the consent decree requirements into the Simplot Don Siding Plant's permit. (P-2016-0055 Project 62103 issued pursuant to IDAPA 58.01.01.200 through 222.)
15 ?A schematic map of the sources and their proximity to the Fort Hall Reservation is available in the docket for this action.
The J.R. Simplot Company-Don Siding Pocatello plant (Simplot Don Siding Plant), in Pocatello, Idaho, is the closest SO 2 source to the Fort Hall Reservation and has the highest SO 2 emissions in the area with 748 tpy in 2017. The Simplot Don Siding Plant is approximately 1 km from the boundary of the Fort Hall Reservation and approximately 1 km from the Pocatello SO 2 monitor (AQS Site ID 160050004). The EPA reviewed SO 2 emissions data for the Simplot Don Siding Plant from 2010 through 2017. As shown in Table 8 of this document, SO 2 emissions have decreased considerably over time and are less than half what they were in 2010.
| 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 |
|---|---|---|---|---|---|---|---|
| 1,634 | 1,647 | 1,563 | 803 | 795 | 732 | 735 | 748 |
[top] The EPA reviewed data from the meteorological station at the Pocatello Regional Airport, which is approximately 6 km west of the Simplot Don Siding Plant. Prevailing winds are from the southwest with an average speed of 4.2 meters per second. Given the close distance of the Pocatello SO 2 monitor to the Simplot Don Siding Plant, the low monitored SO 2 concentrations, and the prevalent wind direction, it is likely that SO 2 emissions from the Simplot Don Siding Plant will be sufficiently dispersed before reaching the Fort Hall Reservation.
In addition to reviewing the 2009-2011 regional scale SO 2 modeling in Idaho's submission, the EPA examined more recent regional-scale SO 2 modeling for the Pocatello area using the same tool Idaho used with updated data from July 2014 to June 2017. 16 The highest design concentration identified in the area is about 6.8 ppb, well under the 1-hour SO 2 NAAQS of 75 ppb. On the Fort Hall Reservation, the highest design concentration identified in the area is 6.3 ppb and occurs west of the Simplot Don Siding Plant. This analysis indicates that SO 2 emissions impacts from the Simplot Don Siding Plant to the vicinity and the Fort Hall Reservation are likely minimal. While this regional-scale modeling is not dispositive as to the determination of whether impermissible SO 2 transport is occurring, it provides information that along with other factors may be considered in a weight of evidence evaluation.
Footnotes:
16 ?The EPA used a tool developed and operated by Washington State University as part of the NW-AIRQUEST consortium. The tool estimates design concentrations from a regionally optimized photochemical air pollutant transport grid model that uses meteorological data and computes air pollutant emissions, transport, and chemistry using the EPA's CMAQ photochemical grid model. The model simulates industrial source emissions from point sources, including the Simplot Don Siding Plant, assuming a constant hourly emission rate of air pollutants based on the annual tons-per-year emissions provided in the 2014 National Emissions Inventory. The technical support document in the docket for this action provides additional information on the NW-AIRQUEST consortium's tool and the EPA's analysis.
P4 Production and The Itafos Conda
The EPA also assessed potential SO 2 impacts from other point sources near the Fort Hall Reservation, P4 Production and Itafos Conda, which are approximately 7 km apart. These sources are located in the Soda Springs region on the east side of the high Caribou Valley plain, along the west flanks of the Caribou Range of mountains. The rugged Blackfoot Lava Fields and high, rocky Chesterfield Range of mountains lie between the Fort Hall Reservation and Soda Springs region and rise to peaks exceeding 7,000 feet.
As shown in Table 7 of this document, these sources are approximately 38 km from the Fort Hall Reservation. The closest SO 2 monitor to these sources is the Caribou County monitor (AQS Site ID 160290031), which is 1 km from P4 Production and 7 km from Itafos Conda. The EPA reviewed SO 2 emissions data for P4 Production and Itafos Conda from 2010 to 2017. As shown in Table 9 of this document, SO 2 emissions at P4 Production have decreased by almost half since 2010. At Itafos Conda, SO 2 emissions have not changed substantially since 2010.
| Facility | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 |
|---|---|---|---|---|---|---|---|---|
| P4 Production | 936 | 1169 | 643 | 615 | 456 | 467 | 478 | 488 |
| Itafos Conda | 341 | 302 | 311 | 410 | 332 | 438 | 364 | 387 |
With a 38 km transport distance over complex, rugged terrain, and the low monitored SO 2 concentrations, it is likely that SO 2 emissions from P4 Production and Itafos Conda will be sufficiently dispersed before impacting the Fort Hall Reservation, and that any impacts to the Reservation from these sources would likely be minimal.
The EPA has reviewed SO 2 sources with emissions of 100 tpy or more within 50 km of the Fort Hall Reservation. Based on the available information, the EPA is proposing to find that Idaho will not contribute significantly to nonattainment of the 2010 1-hour SO 2 NAAQS for purposes of CAA section 110(a)(2)(D)(i)(I) in the Fort Hall Reservation.
We are proposing to conclude that, based on our review of the Idaho submission and our supplemental evaluation, Idaho's SIP meets the prong 1 requirements of CAA section 110(a)(2)(D)(i)(I) for purposes of the 2010 SO 2 NAAQS. In summary, for interstate transport prong 1, we reviewed the Idaho submission and conducted a supplemental analysis of ambient SO 2 monitoring data and SO 2 emission sources within Idaho, neighboring states, and the Fort Hall Reservation. Based on this analysis, we propose to determine that Idaho will not contribute significantly to nonattainment of the 2010 SO 2 NAAQS in any other state or the Fort Hall Reservation, per the requirements of CAA section 110(a)(2)(D)(i)(I).
2. The EPA's Prong 2 Evaluation
The EPA has reviewed available information on SO 2 air quality and emission trends to evaluate Idaho's conclusion that emissions from sources in the State will not interfere with maintenance of the 2010 SO 2 NAAQS in any downwind state. The EPA notes that Idaho's analysis does not independently address whether the SIP contains adequate provisions prohibiting emissions that will interfere with maintenance of the 2010 SO 2 NAAQS in any other state, or the Fort Hall Reservation. In remanding the Clean Air Interstate Rule (CAIR) to the EPA in North Carolina v. EPA, the D.C. Circuit explained that the regulating authority must give the "interfere with maintenance" clause of section 110(a)(2)(D)(i)(I) "independent significance" by evaluating the impact of upwind state emissions on downwind areas that, while currently in attainment, are at risk of future nonattainment, considering historic variability. 17 While Idaho did not evaluate the potential impact of its emissions on areas that are currently measuring clean data, but that may have issues maintaining that air quality, the EPA reviewed additional information, which builds on the analysis regarding significant contribution to nonattainment (prong 1) to determine potential impacts on areas that are measuring clean data. Specifically, because of the relatively low monitored ambient concentrations of SO 2 in Idaho and neighboring states, the levels of SO 2 emissions of Idaho sources, and the large distances between cross-state SO 2 sources, the EPA's weight of evidence evaluation shows that SO 2 levels in neighboring states near the Idaho border do not indicate any inability to maintain the SO 2 NAAQS that could be attributed, even in part, to sources in Idaho.
Footnotes:
17 ? North Carolina v. EPA, 531 F.3d 896, 910-11 (D.C. Cir. 2008). The Court held that the EPA must give "independent significance" to each prong of CAA section 110(a)(2)(D)(i)(I). Id.
[top] Based on our review of the EPA's emissions trends data, as shown in Table 1 of this document, SO 2 emissions from Idaho and neighboring states have decreased substantially over time. 18 From 2005 to 2017, total statewide SO 2 emissions decreased by the following
Footnotes:
18 ?Additional emissions trends data are available at: https://www.epa.gov/air-emissions-inventories/air-pollutant-emissions-trends-data.
The EPA notes that existing sources are subject to the control requirements in the Idaho SIP discussed in our prong 1 evaluation, and any future new and modified stationary sources of SO 2 emissions will be subject to Idaho's SIP-approved pre-construction permitting ("new source review" or "NSR") program. 19 The EPA believes that the permitting regulations contained within these programs will help ensure that ambient concentrations of SO 2 in neighboring states will not be exceeded as a result of new facility construction or modification occurring in Idaho.
Footnotes:
19 ?The EPA approved a consolidated pre-construction permitting program, including both major and minor source NSR, into the Idaho SIP on June 23, 1986 (51 FR 22810). Since that time, we have approved revisions to the program as consistent with the CAA and Federal NSR requirements codified at 40 CFR 51.160 through 40 CFR 51.166, most recently on August 20, 2018 (83 FR 42033).
In conclusion, for interstate transport prong 2, the EPA has incorporated additional information into our evaluation of Idaho's submission, which did not include an independent analysis of prong 2. In doing so, we have reviewed information about emission trends, as well as the technical information considered for our interstate transport prong 1 analysis. We find that the combination of low ambient concentrations of SO 2 in Idaho and neighboring states, including near the Fort Hall Reservation, the large distances between cross-state SO 2 sources, the downward trend in SO 2 emissions from Idaho and surrounding states, and SIP-approved control measures designed to limit SO 2 emissions from new and modified stationary sources in Idaho, indicates that Idaho sources will not interfere with maintenance of the 2010 SO 2 NAAQS in any other state or the Fort Hall Reservation. Accordingly, we propose to determine that Idaho SO 2 emission sources will not interfere with maintenance of the 2010 SO 2 NAAQS in any other state or the Fort Hall Reservation, per the requirements of CAA section 110(a)(2)(D)(i)(I).
IV. Proposed Action
The EPA is proposing to approve the December 24, 2015 Idaho SIP as meeting the interstate transport requirements of CAA section 110(a)(2)(D)(i)(I) for the 2010 SO 2 NAAQS. The EPA is proposing this approval based on our review of the information and analysis provided by Idaho, as well as additional analyses conducted by the EPA to verify and supplement the Idaho SIP, which indicates that Idaho will not contribute significantly to nonattainment or interfere with maintenance of the 2010 SO 2 NAAQS in any other state or the Fort Hall Reservation. This action is being taken under section 110 of the CAA.
V. Statutory and Executive Order Reviews
Under the Clean Air Act, the Administrator is required to approve a SIP submission that complies with the provisions of the Act and applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submissions, the EPA's role is to approve state choices, provided that they meet the criteria of the Clean Air Act. Accordingly, this proposed action merely approves state law as meeting Federal requirements and does not impose additional requirements beyond those imposed by state law. For that reason, this proposed action:
• Is not a "significant regulatory action" subject to review by the Office of Management and Budget under Executive Orders 12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
• Is not an Executive Order 13771 (82 FR 9339, February 2, 2017) regulatory action because SIP approvals are exempted under Executive Order 12866;
• Does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq. );
• Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq. );
• Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);
• Does not have federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999);
• Is not an economically significant regulatory action based on health or safety risks subject to Executive Order 13045 (62 FR 19885, April 23, 1997);
• Is not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, May 22, 2001);
• Is not subject to requirements of section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because it does not involve technical standards; and
• Does not provide the EPA with the discretionary authority to address, as appropriate, disproportionate human health or environmental effects, using practicable and legally permissible methods, under Executive Order 12898 (59 FR 7629, February 16, 1994).
The proposed SIP would not be approved to apply on any Indian reservation land or in any other area where the EPA or an Indian tribe has demonstrated that a tribe has jurisdiction. In those areas of Indian country, the proposed rule does not have tribal implications and will not impose substantial direct costs on tribal governments or preempt tribal law as specified by Executive Order 13175 (65 FR 67249, November 9, 2000). Consistent with EPA policy, the EPA provided a consultation opportunity to the Shoshone-Bannock Tribes concerning the EPA's action on this SIP submission in a letter dated March 7, 2018. The EPA did not receive a request for consultation.
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by reference, Intergovernmental relations, Nitrogen dioxide, Particulate Matter, Reporting and recordkeeping requirements, Sulfur dioxide, Volatile organic compounds.
Authority:
42 U.S.C. 7401 et seq.
Dated: September 25, 2020.
Christopher Hladick,
Regional Administrator, Region 10.
[FR Doc. 2020-21741 Filed 10-2-20; 8:45 am]
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