USDA United States

Department of

Agriculture,

Forest

Service

Rucky

Mountain

Region

740 Simmf; Strcnt

Golden, CO 80401

Voice: 303-275-5350

TDD: 303-275-5367

David A. Finley

Air Quality Administrator

Wyoming Department ofEnviromuental Quality

122 West 25th St. .

Cheyenne, WY 82002

These BART determinations are a key part ofthe regional haze plan the State ofWyoming is

preparing. This plan will demonstrate how Wyoming will make reasonable progress toward

meeting the national goal ofpreventing any future, and remedying any existing, impairment of

visibility in mandatory Class I areas. The regulations describing what these plans should contain

are found at 40 CFR 51.300 through 309. As the Federal Land Manager (FLM) for the North

Absaroka, Washakie, Teton, Fitzpatrick, Bridger, Savage Run, Mount Zirkel, Rawah, Flat Tops,

and Eagles Nest Class I Wildernesses, we are very interested in these BART dete=inations and

the Wyoming Regional Haze Plan as a whole.

The regional haze regulations at 40 CFR 5l.308(i) require consultation between the FLMs and

the State. Specifically, the FLM is to receive 60 days to review and comment on any plan or

plan revision. The State must also include a description ofhow it addressed the FLM comments

ifthey are received in the specified timeframe.

As you Imow, the BART determination must consider the "best system of continuous emissions

control technology" taking into account the following factors: "the technology available, the

costs ofcompliance, the energy and non air quality environmental impacts ofcompliance, any

pollution cOlltrol equipment in use at the source, the remaining usejUllife ofthe source, and the

degree ofimprovement in visibility," 40 CFR Section 51.308(e)(I)(ii)(A).

Our review ofthe five statutory factors leads us to the conclusion that selective catalytic

reduction (SCR) should be BART for nitrogen oxides (NOx) for all units at both the Jim Bridger

and Naughton power plants. We applaud the State ofWyoming for proposing to install SCR at

the 4 units at the Jim Bridger EGD. The FS believes the installation timeframe for SCR should

be within the 2015-2016 tirneframe for all four units at the facility.

·It's Cool to Be Safe Printed on Recycled Paper
David A. Finley, WDEQ

The FS believes that the already-pennitted installation ofwet flue gas desulfurization (FGD)

equipment for the Jim Bridger Power Plant Units 1-4 should be BART. Similarly, the FS

believes that the installation ofwet FGD equipment for the Naughton Power Plant Units 1-3

should be BART.

2

HARV FORSGREN

Regional Forester

Intennountain Region

The United States Forest Service compliments you on your hard work and dedication to

significant improvement in our nation's air quality values and visibility. Cooperative efforts

such as these ensure that, together, we will continue to malce progress toward the Clean Air Act's

goal of natural visibility conditions at our Class I wilderness areas and parks. We appreciate the

opportunity to continue to work closely with your agency as you develop final BART

detenninations for these facilities. If you have questions or comments, please contact Jeff

Sorkin, at (303)-275-5759.

Sincerely,

.tD ~-IIa_ ~Sr~ CKD. CABLE "-/

Regional Forester

Rocky Mountain Region

Enclosures

cc: .JeffA Sorkin, Ann Acheson, Trent R Wickman, Terry Sva1berg, Scott A Copeland, Bruce

Polkowsky, Don Shepherd, Dean Gillam
United States Forest Service Technical Comments

Wyoming BART determinations for Jim Bridger and Naughton Power Plants

The units under consideration are four 530 MW units (numbered 1 through 4) at the Jim Bridger

power plant and 3 units at the Naughton power plant; 160,210,330 MW respectively for units 1

through 3. "

Overall Comments:

The FS commends PacifiCorp and the Wyoming DEQ for the strong NOx controls proposed for

BART and reasonable progress. We believe the proposed controls will significantly improve air

quality in the many Class I areas surrounding the facilities. While we do not agree with every

conclusion, tlle BART documents are thorough and well written.

Demonstration ofthe Extent of Visibility Impacts:

PacifiCorp modeled visibility improvements from proposed BART and reasonable progress

controls. The FS feels it is important to document visibility impacts to Class I areas as

completely as possible in order to place in context the total benefit derived from controls. Then,

the cost of each BART alternative should be divided by the sum ofthe deciview improvement at

all impacted Class I areas to detemrine the cost per deciview. This may result in acceptarlce of a

previously discarded control alternative due to the showing of a reasonable cost ofvisibility

improvement.

As such, the 'FS would like to see visibility benefit modeling for all Class I areas within 300km.

(see maps attached.) Additionally, since there are Class I areas just beyond 300km, if any

modeling ah-eady exists showing visibility improvement benefits greater than 0.5dv beyond

300km, the FS requests that information be included as welL

The State ofWyoming has determined that the Savage Run Wildemess Area will be marlaged as

a Class I airshed. Therefore, tlle FS would like the Savage Run Wilderness Area to be treated as

such in all Regional Haze planning including this BART review.

Pages ES-5 and 5-10 ofthe PacifiCorp BART Analysis discuss "Just-noticeable difference in

atnlospheric haze" indicating that minimal, if any, observable visibility improvements at the

Class I areas would be expected under any ofthe control scemuios. It is incorrect to dismiss a

control strategy on the basis that the resulting improvement is not perceptible or significant. EPA

states in the preamble to its BART Guidelines:

"Even though the visibility improvementji-om an individual source may not be

perceptible, it should still be considered in setting BART because the contribution to haze

may be significant relative to other sow'ce contributions in, the Class I areas. Thus, we

disagree that the degree ofimpainnent should be contingent upon perceptibility. Failing

to consider less-than-perceptible contributions to visibility impairment would igiwre the

CAA '.I intent to have BART requirements apply to sources that contribute to, as well as

h · . t,,3 cause, suc zmpamnen. ,
Five Factor Analysis for BART Selection:

In the BART detennination the State ofWyoming discusses the applicability ofpresumptive

BART to units at the Jim Bridger and Naughton power plants. EPA's view ofpresumptive limits

for 802 and NOx for EGUs are that they are "highly cost effective." EPA goes on to say:

"States, as a general matter, must require owners and operators ofgreater than 750 MW

powerplants to meet these BART emission limits. We are establishing these r-equirements

based on the consideration ofcertain factors discussed below. Although we believe that

these requirements are extremely likely to be appropriate for all greater than 750 MrV

power plants subject to BART, a State may establish different requirements ifthe State

. can demonstrate that an alternative determination isjustified based on a con.~ideration of

the jive statutory factors.,,4 .

So although the presumptive requirements are "extremely likely to be appropriate" a State can

demonstrate otherWise based on the five statutory factors. The FS believes that the 8..c'lalysis of

coal composition is not only flawed in its conclusions, more principally, it does not meet the

requirement for a demonstration ofwhy presumptive limits cannot be reached.

NOx Controls:

The FS sees the infonnation presented as supporting SCR as BART for all units at both Jim

Bridger and Naughton power plants.

The State ofWyoming lists the following reasons for not installing SCR as BART on the 4 units

at the Jim Bridger power plant and units I and 2 at the Naughton power plant:

1) "The cost ofcompliance for installillg SCR on each unit is significantly higher than LNB with

separated OFA."

2) "Combustion control using LNB with separated OFAdoes not require non-air quality

environmental mitigation for the use ofchemical reagents (i. e., ammonia or urea) and there

is a minimal energy impact."

However, the FS believes SCR is BART for all units at both facilities. The State ofWyoming

appears to concur with this finding because, in the detennination, the State says "The cost

effectiveness and incremental cost effectiveness ofthe four proposed BART technologiesfor NOx

are all reasonable". hl addition, FS is confused as to why Wyoming determines SCR as BART

at unit 3 at the Naughton Power Plant at $2830/ton but for unclear reasons not at the other six

units with costs from $2258 - 2848/ton.

The FS would like to point ont that SCR is a mature tec1mology. We are unaware of any

enviromnental degradation due to a properly operated SCR. Furthennore, our inspection ofthe

cost analysis leads us to believe the energy impact associated with operating SCR is included in

the cost analysis, which makes this point raised by the State moot.
FOI·the Jim Bridger Power Plant units, the State ofWyoming indicates:

"The'eumulative 3-year averaged visibility improvementji-om Post-Control Scenario A

across the three Class I areas achieved with Post-Control Scenario B was 0.627 Lldv per

unitji-om Units 1-3 and 0.635 Lldvji-om Unit 4."

This statement makes the case that SCR would result in a significant improvement in visibility.

Each unit by itselfimproves visibility by an amount that results in "contribution" to visibility

impai=ent i.e. it exceeds 0.5 dv. The total benefit of SCR on the four units (~2.5dv) easily

exceeds the threshold for "causing" visibility impai=ent, l.Odv.

Similarly, for the Naughton Power Plant units, the State ofWyoming indicates:

"The cumulative 3-year averaged 98th percentile visibility improvementfrom PostControl Scenario A across both Class I areas achieved 11Jith Post-Control Scenario B was

0.405 Lldv ji-om Unit I and 0.506 Lldv ji-om Unit 2_"

Again, the FS sees this fact as making the case that this is a significant improvement in visibility_

Each unit by itselfimproves visibility by an amount that results in, or approaches, a

"contribution" to visibility impai=ent. The total impact of SCR on the two units approaches the

threshold for "causing" impairnlent.

Regarding SCR in the BART phase ofthe analysis, Table 7 ofthe Wyoming BART Application

Analysis shows a removal efficiency of 84.4 percent for LNB/OFA/SCR to reach 0.07

lblMMBtu. PacifiCorp and Wyoming have underestimated the ability ofmodem NOx control

systems. SCRhas been retrofitted to many eastern pulverized coal boilers that are now

achieving 0.05 lblMMBtu on a 30-day rolling average basis. It is likely that many ofthese

EOUs are burning eastern bituminous coals with higher fuel-bound nitrogen than that burned at

the Jim Bridger Power Plant. Because "fUel nitrogen can accountfor up to 80 percent oftotal

NOxfrom coal combustion" it should be easier for PacifiCorp to achieve lower NOx emissions

than an BOU burning coal with higher fuel-bound nitrogen. IfSCR is capable ofreducing

emissions below PacifiCorp's target, then the amount ofthe reductions and consequent visibility

improvements will increase. These greater efficiencies should be factored into the cost and

visibility analyses.

Reasonable Progress Controls:

The FS requests clarification as to why units 1 & 2 at the Naughton Power Plant are not required

to install SCR as part ofreasonable progress like the other five units.

S02 Controls:

The FS believes that the already-pennitted installation ofwet FOD equipment for the Jim

Bridger Power Plant Units 1-4 should beconsidered BART. Similarly, the FS believes that the
installation ofwet FGD equipment for the Naughton Power Plant Units 1-3 should be considered

BART.

There appears to be an error in the analysis for unit 3 at Naughton. The perfo=ance ofthe wet

FGD was stated to be 0.10 lb/MMBtu (Table 18) but the cost effectiveness analysis was done

based on 0.15lb/MMBtu (Table 24). The cost per ton for S02 reduction should be calculated

using 0.10 lb/MMBtu, ifthat is the correct value.

The FS understands the role ofsection 309 in exempting the State ofWyoming from BART and

reasonable progress controls for S02 based on the demonstration in WRAP Techniclll Support

Document! that the S02 emissions reductions benefits under section 309 exceed those that would

have resulted from BART. Further we understand that the State ofWyoming has met it targets

under the 309 program. The FS would like to know ifthe controls in place at the Naughton and

Jim Bridger Power Plants are at least equivalent to the control scenario used in the demonstration

report. In other words, are the existing S02 controls actually as needed to accomplish the "better

than BART" demonstration?

The FS also notes that the 309 program sunsets in 2018, and that additional S02 controls maybe

appropriate for reasonable progress at that time.

Visibility Impairment:

US EPA BART guidelines2 state that 0.5dv "contributes" to impai=ent, and l.Odv "causes"

impai=ent. The discussion from Ronald Henry is irrelevant and used in an improper context.

References:

1. WRAP Technical Oversight Committee, Regional Technical Support Documentfor the

Requirements of§309 ofthe Regional Haze Rule, 5/2008.

2. 40 CFR Part 51, Appendix Y. U.S. Environmental Protection Agency, "Guidelines for

BART Determinations Under the Regional Haze Rule.", July 6, :;1005, See FR Vol 70, No

128, page3916l.

3. See 40 CFR Part 51, Appendix Y. The U.S. Environmental Protection Agency finalized

it's BART Guidelines on June 15, 2005, and published the preamble and final rule text in

the Federal Register on July 6, 2005. The rulemaking action added Appendix. Y to Part

51, titled "Guidelines for BART Determinations Under the Regional Haze Rule." See

Preamble, 70FR30129, middle colunm.

4. Federal Register, 7/6/05, p.39131
Class I Areas within 300km of Jim Bridger PP

• JIm Bridger PP

Class I Units

CJ NPS

III USFS

I\WiilI FWS
Class I Areas within 300km of Naughton PP

:' 0 Naughton Distance

J • Naughton PP

:' Class I Units

NPS

USFS

FWS