# Interstate Transport State Implementation Plan for 2010 NO 2 

# and 2010 SO 2

State of Idaho Department of Environmental Quality

December 2015Printed on recycled paper, DEQ, December 2015

, PID SSIP , CA 81992 . Costs associated with this publication are available from the State of Idaho Department of Environmental Quality in accordance
with Section 60

- 202, Idaho Code.Interstate Transport SIP for 2010 NO 2 and SO 2

iii 

### Table of Contents

Introduction

................................ ................................ ................................ ................................ ..... 1
Background

................................ ................................ ................................ ................................ ..... 1
Nitrogen Dioxide

................................ ................................ ................................ ............................ 1

Sulfur Dioxi de

................................ ................................ ................................ ................................ . 3
Appendix A. Public Comment and Hearing Material

................................ ................................ ..... 8



### List of Tables

Table 1. Areas previously designated nonattainment for SO 2 annual NAAQS and 24

- hour NAAQS.

................................ ................................ ................................ ........................... 4 Table 2 Top 10 SO 2 emitters in Idaho (2014 data).

................................ ................................ ........ 4 Table 3. Design values for Idaho SO 2 monitors, 2014.

................................ ................................ .. 6 Table 4. Design values for Idaho and surrounding states, 2011

– 2013.

................................ .......... 7



### List of Figures

Figure 1. Modeled NO 2 design values, 2009

– 2011.

................................ ................................ ....... 3 Figure 2. Top five SO 2 point sources and current SO 2 monitors in Idaho.

................................ ..... 5 Figure 3 . Modeled background SO 2 background concentrations for Idaho.

................................ ... 6Interstate Transport SIP for 2010 NO 2 and SO 2

iv This page intentionally left blank for correct double

- sided printing.Interstate Transport SIP for 2010 NO 2 and SO 2

1 

## Introduction

The interstate transport provision in the Clean Air Act (CAA) section 110(a)(2)(D)(i) ( i.e

. , the “good neighbor” provision) requires each state to submit a s tate i mplementation p lan (SIP) that prohibits emissions that will have certain adverse air quality effects in other states. This SIP submittal, along with other components of an infrastructure SIP, is due within 3 years of the US Environmental Protection Agency (EPA) promulgat ing a new or revised National Ambient Air Quality Standard (NAAQS). On January 22, 2010

, EPA promulgated a revised NAAQS for nitrogen dioxide (NO 2 ) and on June 3, 2010

, EPA promulgated a revised sulfur dioxide (SO 2 )

standard. Idaho submitted NO 2 and SO 2 i n frastructure SIPs (minus the elements addressed in this submittal) on September 16, 2013. Due to uncertainty surrounding the effect of pending court

cases in other states , Idaho did not include an analysis addressing all interstate transport provisions. Id aho’s NO 2 and SO 2 infrastructure SIPs were approved by EPA on September 10, 2014 (79 FR 46707)

. This SIP submittal addresses Idaho’s remaining infrastructure SIP obligations under section 110(a)(2)(D)(i) for SO 2 and NO 2

.

The SIP was made available for pub lic comment fr om November 20 through December 21,

2015

. A public hearing was held on December 21 and noticed 30 days in advance

. No comments were received during the public involvement process. The legal proof of publication in the

Idaho Statesman , hearing notice, and copy of the Idaho Department of Environmental Quality ’s

news release are provided in Appendix A.



## Background

C A A s ection 110(a)(2)(D)(i) identifies four distinct “prongs” related to the impacts of air pollutants transported across state lines. F or a new or revised NAAQS

, CA A requires each SIP contain adequate provisions prohibiting any source or other type of emissions activity within the state from emitting air pollutants that result in the following:

1. C ontribute significantly to nonattainment of the applicable NAAQS in any other state

. 2. I nterfere with maintenance of the applicable NAAQS in any other state

. 3. I nterfere with measures required to be included in the applicable SIP for any other state to prevent significant deterioration of air quality

. 4. I nterfere with measures required to be included in the applicable SIP for any other state to protect visibility.

Th is analysis focuses on states that are contiguous to Idaho: Washington, Oregon, Nevada, Utah, Wyoming, and Montana. Since both NO 2 and SO 2 will most likely either disperse in the atmosphere or chemically react to form a secondary pollutant within a few miles of a source, impacts beyond the contiguous states are not considered

.



## Nitrogen Dioxide

EPA first set NO 2 standards in 1971 for both a pr imary standard (to protect health) and a secondary standard (to protect the public welfare) at 53 parts per billion (ppb), averaged annually. EPA reviewed the standards in 1985 and 1996 , and after each review, decid ed to retain

the standards

. In 2005, EPA began another review resulting in the January 22, 2010, rulemakingInterstate Transport SIP for 2010 NO 2 and SO 2

2 that establish ed an additional primary NO 2 standard at 100 ppb, averaged over 1 hour (75 FR 6474).

Idaho addressed prongs 3 and 4 in its September 16, 2013

, NO 2 i nfrastructure SIP submittal.

P rong 4 (visibility impairment) was addressed in the Idaho Regional Haze SIP , which was approved by EPA on June 9, 2011 (76 FR 33651)

. This SIP submittal addresses the requirements of CAA section 110(a)(2)(D)(i)(I) for revised 2010 NO 2 NAAQS for the first two prongs listed

above.

On January 20, 2012

, EPA designated all areas of the country as “unclassifiable/attainment” for

the 2010 NO 2 NAAQS (77 FR 9532). The available air quality data show that all monitored

areas in the coun try meet the 2010 NO 2 NAAQS for 2008

– 2010. No state or tribe recommended an area be designated “nonattainment.” A s listed in EPA ’s NO 2 Design Value s r eport ( http://www.epa.gov/airtrends/values.html ), only one maintenance area exists for the prior

annual NO 2 NAAQS (Los Angeles, California ). With no nonattainment or maintenance areas in surrounding states, Idaho does not significantly contribute to nonattainment or maintenance of these NAAQS in any of t h e contiguous states.

As further evidence that Idaho ’s NO 2 emissions do not impact neighboring states, Figure 1

shows the estimated 2009

– 2011 1

- hour NO 2 design value background concentrations for Idaho ( http://lar.wsu.edu/nw

- airquest/lookup _faq.html )

. T he design values are well below the NAAQS,

and areas of increased NO 2 concentrations are localized in nature.

Conclusion

— Based on the information, Idaho has met the CAA requirements for prong s 1 and

4

.Interstate Transport SIP for 2010 NO 2 and SO 2

3 Figure 1

. M ode led NO 2 design values

, 2009

– 2011

.



## Sulfur Dioxide

Primary standards for SO 2 were first set in 1971, at 140 ppb averaged over a 24

- hour period, not to be exceeded more than once per year, and 30

- ppb annual arithmetic mean. In 1996, EPA subsequently reviewed the primary standards

, and after each review, decided to retain the

standards

. More recently, on June 2, 2010, EPA promulgated a revised primary SO 2 standard at 75 ppb, based on a 3

- year average of the annual 99 th percentile of 1

- hour daily maximum

concent rations (75 FR 35520).

For the revised 2010 SO 2 standard, Idaho addressed interstate transport prongs 3 and 4 in its September 16, 2013

, SO 2 i nfrastructure SIP submittal. The Idaho Regional Haze SIP also addressed prong 4

, and the SIP was approved by EPA o n Jun e 9, 2011 (76 FR 33651). The current SIP submittal addresses prongs 1 and 2 of CAA section 110(a)(2)(D)(i)(I) for the revised

2010 SO 2 NAAQS.

Unlike NO 2 , a nonattainment area for the revised SO 2 NAAQS exists in an adjacent state. Billings, Montana

, w as declared nonattainment for the 1

- hour SO 2 standard in 2013 (77 FR 9532). In addition, areas in neighboring states were declared nonattainment for the earlier

SO 2 standards ( Table 1 )

.Interstate Transport SIP for 2010 NO 2 and SO 2

4 Table 1 . Areas previously designated nonattainment for SO 2 annual NAAQS and 24

- hour NAAQS.

Designated Area State Designation Status

East Helena Montana Nonattainment

Laurel Montana Nonattainment

Central Steptoe Valley Nevada Maintenance

Salt Lake County Utah Nonattainment

Tooele County (part) Utah Nonattainment

T o determine whether SO 2 emissions from facilities in Idaho could negatively impact any of these maintenance or nonattainment areas, the largest SO 2 e mission sources were identified from

our 2014 e missions i nventory ( Table 2 ). Since SO 2 will most likely either disperse in the atmosphere or chemically react to form a secondary pollutant within a few miles of the source, only large pollutant sources in proximity to the s tate boundary would be expected to significantly

contribute to or inte rfere with air quality in adjacent states. Only one of the facilities shown in

Table 2 (Clearwater Paper Corp oration ) is within 5 miles of the Idaho border. The Clear water Paper Corp oration’s emissions are relatively small (~42 tons in 2014)

, and the facility is over 400 miles from Billings, Montana

, and hundreds of miles from the older

nonattainment/maintenance areas listed in Table 1

.

Table 2 Top 10 SO 2 emitters in Idaho (2014 data)

.

Facility ID Facility Name Pollutant Emissions (tons)

02700010 Amalgamated Sugar (Tasco

— Nampa) SO 2 1

, 585.9

08300001 Amalgamated Sugar (Tasco

—Twin Falls) SO 2 1

, 081.9

07700006 JR Simplot Company

— Don Siding SO 2 794.9

02900001 P4 Production L LC (T V Facility) SO 2 580.5

02900003 Nu

- West Industries, Inc

. (Agrium Conda Phosphate Operations) SO 2 332.4

06700001 Amalgamated Sugar (Tasco

— Paul) SO 2 248.3

01900025 Busch Ag Resources Inc

. — Malt Plant SO 2 42.6

06900001 Clearwater Paper Corp oration

— P PD & C PD SO 2 42.2

02700009 JR Simplot Co mpany Food Group

— Caldwell SO 2 26.8

Idaho ’s SO 2 monitoring network can also be used to characterize the SO 2 emissions of three of

the four largest SO 2 emitters listed in Table 2 and shown in Figure 2

.Interstate Transport SIP for 2010 NO 2 and SO 2

5 Figure 2

. T op five SO 2 point sources and current SO 2 monitors in Idaho.

I n eastern Idaho (Pocatello and Soda Springs)

, source

- oriented monitors report the highest

ambient SO 2 concentrations surrounding these facilities. The Meridian monitor is more of a background monitor but should reflect any significant emissions from the larges t SO 2 emitter in Idaho (TASCO in Nampa). N ote : TASCO ’s Nampa facility is i n the process of converting a coal boiler to natural gas

, which should result in a significant decrease in SO 2 emissions from this facility. As shown in Table 3 , all of the Idaho monitors have 2014 3

- year design values that are

below the 75

- ppb SO 2 NAAQS.Interstate Transport SIP for 2010 NO 2 and SO 2

6 Table 3 . Design v alue s for Idaho SO 2 monitors , 2014

.

Site County/AIRS ID 99 th Percentile

— Highest Daily Maximum

1

- H our Average (ppb) 3

- Y ear Design Value (ppb) 2012 2013 2014

Pocatello STP Bannock 73 40 38 51

Soda Springs Caribou 35 31 23 30

Meridian
St. Luke’s Ada 6 11 5 7

As further evidence that Idaho ’s SO 2 emissions do not impact neighboring states, Figure 3 shows

the estimated 2009

– 2011 1

- hour SO 2 modeled design value background concentrations for the

state . This map was generated by Washington State University researchers using the AIRPACT3

mod el ( http://lar.wsu.edu/nw

- airquest/lookup_faq.html )

. T he design values are well below the NAAQS value of 75 ppb, and areas of increased SO 2 concentrations are localized in nature.

Figure 3 . Modeled background SO 2 background concentrations for Idaho.

The Idaho Department of Environmental Quality reviewed EPA’s Clean Air Status and Trends

Network ( CASTNET ) monitoring data ( http://epa.gov/castnet/javaweb/index.html )

. CASTNET is a national air quality monitoring network designed to provide data to assess trends in air quality, atmospheric deposition, and ecological effect s due to changes in air pollutant emissions. CASTNET provides long

- term air quality monitoring in rural areas to determine trends in regional atmospheric nitrogen, sulfur, and ozone concentrations and deposition fluxes of sulfur and nitrogen pollutants to evaluate the effectiveness of national and regional air pollution control

programs. The SO 2 data for the w estern United States show low background SO 2 levelsInterstate Transport SIP for 2010 NO 2 and SO 2

7 throughout the year. Both average weekly and seasonal SO 2 concentrations were low (<6 ppb)

indicat ing that the regional SO 2 background concentrations are relatively low, which in turn implies that the bulk of the SO 2 in urban receptor areas is locally generated and not a regional or transport problem.

Finally, as listed in EPA ’s 2013 SO 2 Design Value s r eport ( http://www.epa.gov/airtrends/values.html ), the valid 3

- year design values for SO 2 for 2011

– 2013 indicate that except for Yellowstone County, Montana (area declared nonattainment)

, n o other areas in the surrounding states have significant SO 2 issues ( Table 4 )

.

Table 4

. D esign v alues for Idaho and surrounding states

, 2011

– 2 013

.

State County Valid 3

- Year Design

Value

Idaho Caribou 40

Montana Richland 4

Montana Yellowstone 64

Nevada Clark 8

Nevada Washoe 6

Oregon Multnomah 6

Utah Davis 9

Utah Salt Lake 21

Utah Salt Lake 20

Utah Salt Lake 7

Washington Clallam 1

Wyoming Campbell 38

Wyoming Laramie 6

Wyoming Sweetwater 18

Wyoming Weston 12

Conclusion

— Based on the analysis of monitoring and modeling data provided above, Idaho ’s

SO 2 emissions do not result in the following:

1. C ontribute significantly to nonattainment of the applicable NAAQS in any other state

. 2. I nterfere with maintenance of the applicable NAAQS in any other state

.Interstate Transport SIP for 2010 NO 2 and SO 2

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## Appendix A. Public Comment and Hearing MaterialInterstate Transport SIP for 2010 NO 2 and SO 2

9Interstate Transport SIP for 2010 NO 2 and SO 2

10Interstate Transport SIP for 2010 NO 2 and SO 2

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