Nevada Regional Haze 5-Year Progress Report, November 2014 6-1

6

Chapter Six – Assessment of Changes 

Impeding Visibility Progress 

(40 CFR 51.308(g)(5))

Table of Contents

6.1 Status Summary................................................................................................................ 2

6.2 Significant Emission Changes within Nevada ................................................................. 2

6.3 Non-Nevada Sources Impacting the Jarbidge Wilderness Area ...................................... 4

6.4 Nevada’s Impacts on Nearby Class I Areas..................................................................... 6
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6.1 Status Summary

This chapter evaluates visibility conditions measured at JARB1 from the baseline to the 2008

through 2012 progress period, and triennial NEI years from 2002 to 2011 (and 2012 for Nevada 

point sources) to determine if progress has been impeded by changes in anthropogenic emissions 

within the State. It further considers changes in anthropogenic emissions, or the status of BART,

in neighboring states that could

affect progress at the Jarbidge 

WA. Finally, Nevada’s 

contribution to Class I areas in 

nearby states is reviewed. 

Nevada concludes that progress 

towards achieving its 2018 

visibility conditions goal has not 

been impeded by any significant 

anthropogenic emissions 

changes within or outside the 

State.

6.2 Significant Emission Changes within Nevada

40 CFR 51.308(g)(5) requires “[a]n assessment of any significant changes in anthropogenic 

emissions within or outside the State that have occurred over the past 5 years that have limited or 

impeded progress in reducing pollutant emissions and improving visibility.” Figure 6-1 shows

the baseline and rolling 5-year averages of speciated light extinction at JARB1 for the 20 percent

worst days from 2005 through 2012. Figure 6-2 presents similar information, but for the best

days. For the worst days, the data show a reduction in sulfate and nitrate for the three most 

recent 5-year periods (see also the assessment of visibility conditions at Jarbidge WA in Chapter 

Four). Figure 6-1 also shows very clearly how the worst days data is influenced by natural 

sources from year to year. Note how the most recent rolling 5-year average data is skewed by an 

exceptionally high year of wildfires (particulate organic matter) in 2012, contributing to an 

increase of more than 2.5 Mm-1from the preceding 5-year average (discussed in detail in Chapter 

Four). 

For the best days, there are noticeable reductions in visibility impairment due to sulfate, nitrate, 

particulate organic matter, and elemental carbon from the baseline to the current planning period. 

Light extinction for soil, coarse mass and sea salt remain fairly constant for the best days.

51.308(g) . . . Periodic progress reports 

must contain at a minimum . . .

(5) An assessment of any significant 

changes in anthropogenic emissions 

within or outside the State that have 

occurred over the past 5 years that have 

limited or impeded progress in reducing 

pollutant emissions and improving 

visibility.
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Figure 6-1. Worst Days for Baseline and Rolling 5-Year Averages Speciated Light 

Extinction through Planning Period Measured at JARB1

Figure 6-2. Best Days for Baseline and Rolling 5-Year Averages Speciated Light Extinction

through Planning Period Measured at JARB1
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Table 6-1 presents actual emissions in tons per year for Nevada point sources for SO2, NOx, 

PM10 and VOC for years 2002, 2005, 2008, 2011 and 2012. Years 2002, 2005, 2008 and 2011 

were chosen as they are the most complete inventory years submitted to USEPA for the NEI. 

2012 was the most recent dataset available for Nevada’s point sources. It is noteworthy that for 

all four pollutants, there has been a decrease realized in actual emissions over the ten-year 

period. SO2 decreased by nearly an order of magnitude and NOx decreased almost seven-fold. 

Further reductions are expected as BART is implemented in Nevada. These reductions in 

emissions could only help to assist the progress toward improving visibility, not impede it.

Table 6-1. Actual Emissions (tpy) for Nevada Point Sources 2002, 2005, 2008, 2011, 2012*

Year SO2 NOx PM10 VOC

2002 50,619 55,876 6,868 2,132

2005 54,243 52,087 4,643 1,646

2008 10,497 21,680 3,465 1,600

2011 5,959 10,548 3,331 971

2012 5,278 8,324 2,629 986

*2002 through 2011 data are actual emissions values submitted by the NDEP to the NEI. 2012 data are actual 

emissions values for major and minor point sources from the NDEP permitting database.

6.3 Non-Nevada Sources Impacting the Jarbidge Wilderness Area

Chapter Two discusses the status of implementation of proposed regional haze control measures, 

including Section 2.5.2, which specifically addresses the status of BART implementation in 

states adjacent to Nevada that may impact Jarbidge WA. Because of the location of the Jarbidge 

WA, it is likely more strongly affected by emissions originating from within the Snake River 

Plain than those emitted from within the Great Basin (see Chapter Two). 2018 source 

apportionment modeling, discussed in Chapter 4 of Nevada’s 2009 RH SIP and summarized in 

Table 4-5 of that document, indicates that Idaho is the second largest contributor (contributing 

10.3 percent) to modeled sulfate concentrations at JARB1 on the worst days and Oregon is the 

third (contributing 7.2 percent) (Outside Domain is first at 43.8 percent). Idaho is the highest 

contributor to modeled nitrate concentrations at JARB1 on the worst days (Outside Domain is 

next at 27.5 percent). Therefore, this section discusses the changes to anthropogenic emission 

sources in Idaho and Oregon focusing on the implementation of BART during this first 5-year 

progress period. 

As discussed in Section 2.5.2, two facilities in Idaho were subject to BART: the Monsanto/P4 

Production in Soda Springs and the Amalgamated Sugar Company (aka TASCO Nampa) in 

Nampa. The emissions changes resulting from BART implementation at these facilities are 

detailed below and summarized in Table 6-2.
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Table 6-2. Comparison of Projected 2018 and Actual 2011 Emissions from BART Facilities 

in Idaho and Oregon

Facility

NOx (tpy) SO2 (tpy)

Plan 02d 2011 NEI PRP18a Plan 02d 2011 NEI PRP18a

Monsanto/P4 1,531 2,520 2,231 12,197 1,020 3,397

Amalgamated Sugar 

(TASCO)* 1,101 1,042 944 1,798 1,659 1,235

Boardman** 8,378 4,049 4,960 12,248 13,103 3,235

Totals 11,010 7,611 8,135 26,243 15,782 7,867

* BART compliance required by July 22, 2016.

** BART compliance required by July 1, 2014.

At the Monsanto/P4 facility, no new NOx controls were required for BART, and existing SO2

controls were determined to be BART. Emissions of NOx in the PRP18a inventory were 

predicted to increase by 700 tpy from the Plan 02d inventory, while SO2 emissions were 

predicted to decrease by 8,800 tpy. Emissions reported in the 2011 NEI for NOx are consistent 

with the projected PRP18a inventory, while SO2 emissions are even lower than predicted. 

Annual NOx emissions in the projected 2018 inventory are 2,231 tpy with actual emissions of 

2,520 tpy reported in the 2011 NEI, while annual SO2 emissions were projected to be 3,397 tpy 

with actual emissions of 1,020 tpy reported in the 2011 NEI.

SO2 emissions from the TASCO Nampa facility were predicted to decrease 563 tpy and NOx

emissions by 157 tpy from the Plan02d to PRP18a inventories. Emissions reported in the 2011 

NEI are somewhat greater than those in the projected PRP18a inventory. Projected 2018 annual 

NOx emissions were 944 tpy and actual 2011 emissions were 1,042 tpy; projected 2018 annual 

SO2 emissions were 1,235 tpy and 2011 actual emissions were 1,659 tpy. Thus, the TASCO 

Nampa facility emitted more pollutants in 2011 than projected in the PRP18a inventory. 

However, full compliance with BART is not required until July 22, 2016 and is fully expected. 

Thus, one of Idaho’s BART facilities is currently achieving the emissions reductions which 

Nevada depended on in setting its RPG, while a second BART facility in Idaho is not, yet. 

As discussed in Section 2.5.2, one facility in Oregon was subject to BART: the PGE Boardman 

Power Plant (Boardman). The emissions changes resulting from BART implementation at this 

facility are detailed below and shown in Table 6-2.

SO2 emissions from Boardman were projected to decrease by 9,013 tpy and NOx emissions to 

decrease by 3,418 tpy from the Plan02d to the PRP18a inventory. However, SO2 emissions 

reported in the 2011 NEI are much greater than those in the projected PRP18a inventory. The

projected 2018 annual SO2 emissions are 3,235 tpy, while SO2 emissions reported in the 2011 

NEI are 13,103 tpy. Boardman’s actual NOx emissions are lower than the 2018 projection of 

4,960 tpy at 4,049 tpy reported for 2011. Thus, the Boardman facility emitted more SO2 and less 
Nevada Regional Haze 5-Year Progress Report, November 2014 6-6

NOx in 2011 than projected in the PRP18a inventory. However, compliance with the BART SO2

emission limitation is not required until July 1, 2014, and significant SO2 reductions are 

anticipated when the facility resumes operations in 2014 with the required controls. 

NDEP staff spoke with Doug Walsh, Senior Environmental Engineer with the Oregon 

Department of Environmental Quality Eastern Regional Office in Pendleton, Oregon, regarding 

the status of implementation of SO2 controls (phone conversation with Frank Forsgren, NDEP, 

on August 19, 2014). Mr. Walsh informed the NDEP that the facility had resumed operations 

and was refining operation of the SO2 controls and undergoing testing. At this time there is 

insufficient data to confirm that the Boardman facility is meeting the BART SO2 emission limits.

Table 6-2 presents the 2002 baseline emissions, 2018 projected emissions, and 2011 actual 

emissions for the three subject-to-BART facilities located in Idaho and Oregon. The sum of 

actual 2011 NOx emissions from these facilities is approximately 500 tpy less than the 2018 

projected emissions, while the sum of 2011 actual SO2 emissions is nearly 8,000 tpy greater than 

the 2018 projected emissions. Note that 2011 precedes the compliance dates for TASCO and 

Boardman. 

Because visibility impairment resulting from nitrate and sulfate is trending downward at Jarbidge

WA and emission reductions from BART controls in Idaho and Oregon are either in accordance 

with the projected 2018 inventory or are expected to be before 2018, Nevada concludes that there 

are no significant changes in anthropogenic emissions from outside the State that are impeding 

progress at Jarbidge WA.

6.4 Nevada’s Impacts on Nearby Class I Areas

This section reviews Nevada’s impacts on nearby Class I areas based on particulate source 

apportionment modeling conducted by the WRAP. Analysis of the data demonstrates that 

Nevada is reducing its contributions to neighboring states consistent with its impacts. Section 

4.3.3 of Nevada’s 2009 RH SIP discusses the results of the source apportionment modeling and 

identifies Nevada’s contributions to modeled sulfate (Table 4-3) and nitrate (Table 4-4) at all 

Class I areas in the five states adjacent to Nevada. The tables show Nevada’s extinction 

contribution (as a percentage) for the best and worst days for 2002 and 2018. Nevada’s 

maximum 2018 best days sulfate contribution (7.2 percent, the fourth largest contributor at this 

site) occurs at the Sawtooth Wilderness Area in Idaho and for the worst days at Zion National 

Park in Utah (5.6 percent, the sixth highest contributor). For nitrate, Nevada’s maximum 2018 

best days nitrate contribution (12.4 percent, the fourth largest contributor) occurs at Joshua Tree 

National Park and for the worst days at Bliss State Park (20.0 percent contribution, third highest 

contributor) in California. The Bliss IMPROVE monitor represents the Desolation Wilderness 

Area and Mokelumne Wilderness Area in California. Table 7-6 of the 2009 RH SIP shows 

Nevada’s share of required emissions reductions to achieve reasonable progress goals at nearby 

Class I areas.
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Chapter Five of this document summarizes the changes in emissions from all sources within the 

State resulting from the implementation of Nevada’s 2009 RH SIP. Tables 5-5 through 5-15 

present the 2002 and 2008 emission inventories and the difference between the two for each 

visibility impairing pollutant. Table 5-5 documents a 75 percent reduction in the state-wide 

sulfur dioxide emissions, while Table 5-7 presents similar data for nitrogen oxides and 

documents a 26 percent reduction in state-wide nitrogen oxide emissions. These emissions 

reductions far exceed Nevada’s contribution to visibility impairment in Class I areas in the five 

adjacent states.