### $/dv) but higher because they would be applied to larger sources. We therefore recomm end against use of capital cost.
We agree that cost per ton and incremental cost per ton are appropriate factors, and note that NDEP determined tha t an average of $3,050 /to n was an acceptable cost for Low-NO x 

### Burners (LNB) and Flue Gas Recircu l ation (FGR) at Tracy Generating Station (TGS) Unit #1 , and that $4,972 per ton was an acceptab l e incremen tal cost for LNB+FGR at TGS Unit #2

. However, we continu e to advise aga inst over -reliance upon incremental cost. First, it is generally understood that the cost/ton of pollu tion control is an expone ntial function with an increasing slope as higher control efficiencie s are approached. Thus, the incremental cost of moving from lower control to higher control wi ll increase a s higher con t r o l effic ienc ies are sought. One way to deal with this problem is to lo ok not at the absolute va lues of the incremental cost, but to the rela tive r a tios of the incremental costs.

The incremental cos t eva luation pr ob lem is apparent at For t Churchill G e nerating Station (FCGS) where the incremental cost ratio of the LNB+FGR s t rategy chosen by NDEP is 2.7 times the next-low est-$ /ton s t r a tegy (LNB). How ever, NDEP rejected the LNB + SCR strategy, even though its relative incrementa l cost ratio was only 2.0.
At RGGS, NDEP rejected any strategy with a relative increm ental cost ratio greater than 1.1.
Although NDEP did not explain how it considered th e importance of actually relating costs to visib i lity improvement for this v i s i bilit y improvement program, we also note that NDEP found that a cos t o

f

$9.8 millio n/dv was acceptable fo r addition o f

LNB plus Selective Non

- Catalytic Reduction (SNCR) at Tracy #3.
Applying this $9.8 million/dv “benchmark” to the Nevada BART sources and using the NDEP data in its T able #1 produces the following conclusions for B ART:

• At Tracy #1, BART is LNB+FGR as proposed by NDEP.

• At Tracy #2, BART is LNB+FGR as proposed by NDEP.

• At Tracy #3, BART is LNB+SNCR as proposed by NDEP.

• At Ft. Churchill #1, BAR T is LNB+FGR as proposed by NDEP.

• At Ft. Churchill #2, BAR T is LNB+FGR as proposed by NDEP.

• At Reid Gardner #1, BART is LNB + S CR.

• At Reid Gardner #2, BART is LNB + S CR.

• At Reid Gardner #3, BART is LNB + S CR.
If we use NDEP’s determina tions that an average of $3,050/ton was an acceptab l e cost for LNB+FGR at TGS Unit #1, and that a cost of $9.8 millio n/dv was acceptable for addition of LNB+SNCR at TGS #3 as our criteri a, we arrive at the same results.
On average cost/ton and cost/dv bases, LNB+SC R is clearly BART at all three RGGS units. Despite NDEP’s assertion that it did not rely so lely upon incremental cost s, it appears that the only way NDEP can justify rejec ting LNB+SCR at RGGS is on t hat basis. NDEP should clearly state the basis for its BA RT determinations, and how it includ ed effects on visibility.

D-61

### NDEP follow-up response: USEPA’s BART guidance 6 

### lists five factors states m u st c onsider in identifying BART, but does not identify any individual factor for greater cons ideration as the FLMs have with the f i fth factor, the degree of visibility improvem e nt which m a y reasonably be anticipated from the use of BART. The BART guidance 7 

### provides direction on selecting the “bes t” a l terna tive inc l uding identificatio n of the average and increm ental co st, consideration of the m o deled visibility im pacts, justification for adopting the technology sele cted as the “best” level of control, and an explanation of the CAA fact ors leading to the B A RT option selected. The guidance 8



### recomm ends two types o f cost-effectiveness ca lcu l ations – average cos teffectiv eness and increm ental cost effectiv eness. NDEP has followed the guidance provided in Appendi x Y in our identification of BART controls for Nevada sources, in spite of the contenti ons to the contrary by the FLM community. However, NDEP did not apply a cap on capital cost, cost per ton, or increm ental cost as im plied by NPS, but evaluated th e cost effectiveness and ca pital cos tfor each facility ind e pend ently (i.e., on a case-by -case b a sis in accordan ce with Appe ndix Y guidance). Acceptable costs for BART controls at one source did not determine acceptab l e BART contro l costs at other sources (i.e., Nevada has not establish e d “benchmarks” th at define acceptable BART cost m e trics. Acceptable costs were d e term ined on a source -b y-source b a s i s.). Althou gh NPS recommends agains t usin g capital cos tin th e BART determ ina tion process, note that ca pita l cost, co upled with contro l efficiency determ ine the control cost (i.e., cost per ton).
As NDEP has stated in previ ous responses to F L M comme nts (see Appendix C, NPS-NW S Comm ent 17 and NDEP Response), Nevada does not agree with the optiona l cost effectiveness

m easure of dollars per d eciview ($/dv) of visibi lity im provem e nt. Neva da notes that $/dv is an optional m e asure of cost effectivenes s as listed in the BART guidance 9 

### and that EPA provides no guidance on the use of this m e tric in the selection of BART controls.

Nevada has evaluated the inherent uncertainty in use of $/dv as a cost effectiv eness m e tric using Oregon DEQ’s cost evaluation for the Boardm a n facility. The annual cost of installing and operating NLNB/MOFA with SDFGD as BART controls f o r the Boardm an f acility is approxim a tely $40M. NDEP has used these cost s and DEQ’s modeled post-BART visibility im prove m e nt at all 14 Class I areas w ithin 300 km of the facility to calculate the cost effectivenes s in m illions of $/dv. The results were used to ev aluate how the num ber and distribution of Class I areas affect $/dv as a cost effectivenes s m e tric.

NDEP calculated the cost effectiveness in $/dv fo r five different groupings of Class I areas, as f o llows:

• All Class I areas within 300 km of t h e Boardm a nfacility (M t. Adam s, Goat Rocks, Mt. Hood, Eagle Cap, Strawberry Mountain, Mt. Ra iner, Mt. Jefferson, Alpine Lakes, Three Sisters, Mt. Washington, He lls Canyon, Glacier Peak, Diam ond Peak, North Cascades),

6 4 0 CFR Part 5 1 Ap pe ndi x Y (I ) (C ) (2 ) 7 4 0 CFR Part 5 1 Ap pe ndi x Y (I V) (E ) (2 ) 8 4 0 CFR Part 5 1 Ap pe ndi x Y (I V) ( D ) ( 4 ) ( b ) 9 4 0 CFR Part 5 1 Ap pe ndi x Y (I V) ( E) ( 1 ) ( 4 )



### D-62

### • The 5 Class I areas clo s est to th e facility (M t. Ad am s, Goat Rocks, Mt. H ood, Eagle Cap, Strawberry Mountain),

• The 5 Class I areas in the m i ddle distance (M t R a iner, Mt. Jefferson, Alpine Lakes, T h ree Sisters, Mt. Washington),

• The 2 closes t and 3 m o st distan t Clas s I areas (M t. Adam s, Goat Rocks, Glacier Peak, Diam ond Peak, North Cascades), and

• The 5 m o st distant Class I areas (Mt. W a shington, Hells Canyon, Glacier Peak, Diamond Peak, North Cascades). The results are presented in Table 1.

TABLE 1. EVAL UATI ON OF $/DV AS C O ST EFFECTIVENESS ME TRIC

Ba s e l i n e Vi s i b i l i t y (d

v ) Ph as e I Vi s i b i l i t y (d

v ) P h as e I Im pr ov em en t (d v) Co s t E f f e ct i v e n es s ( m i l l i o n s $/ dv )

M t

. Ad a m s , Go a t Ro c k s , M t . Ho o d , E a g l e C a p , S t r a wb e r r y

M o u n t

a i

n , M t

. R a i n e r , M t

. J e f f er so n, A l p i ne L a k e s , T h r e e S i st ers , M t

. W a shi ng t o n , H e l l s C a n y on , G l a c i e r Pe ak , D i am o n d P eak , N o r t h C a sc ad es 3 1 .0 9 1 3

. 8 4 1 7 .2 5 2 .3 2

M t

. Ad a m s , Go a t Ro c k s , M t . Ho o d , E ag l e C a p , S t ra w b e r r y

M o u n ta in 1 3 .6 5 6

. 4 1 7 .2 4 5 .5 2

M t

. R a i n er , M t

. J e f f

er s o n , Al p i n e La ke s , Th r e e

S i s t e r s , M t

. W a sh i n g t o n 1 2 .0 0 5

. 2 6 6 .7 4 5 .9 3

M t

. A d a m s , G o at R o ck s , G l ac i e r P e a k , D i am o n d P e a k , N o rt h C a sc ad es 8. 59 3

. 6 6 4. 9 3 8. 1 1

M t

. W a s hi ngt on , H e l l s C a ny o n , G l a c i er P e ak , D i a m on d P e a k , N o r t h C a sc ad es 7. 77 3

. 1 8 4. 5 9 8. 7 1 M o s t Di s t a n t 5 CI A s Al l C I As wi t h i n 3 0 0 k m

C los e s t 5 C I A s

5 CI As i n M i d d l e Di s t a n c e

2 C l o s e s t a n d 3 M o s t D i s t a n t C I A s



### Table 1 shows a considerable range of cost s depending on the num ber and location of the im pacted Class I areas. These costs range fr om $2.32 m illio n to $8.71 mill ion/dv of visibility im prove m e nt depending on the num ber and location of the affected Class I areas. Tab l e 1 shows that the m o re distant the Class I areas the higher the cost of BA RT controls in $/dv, w h ile the closer the Class I areas the lower th e cost in $ / dv . Note that the trad it ional m e asures of cost effectivenes s; total annu alized costs in dollars ; c o st ef f ective n ess indollars per ton; and increm ental cost effectiveness in dollars per ton, rem a in constant . Only the num ber and location of the Class I areas were change d for this evaluation. The resu lts clearly dem onstrate how the location and num b er of Class I areas can influen ce the use of $/dv as a cost effe ctiven ess m e tric.

D-63

### NDEP has utilized capital costs, cost per t on of pollutant removed, and increm ental cost differences in our cost evaluation of BART controls. NDEP does not accept the use of $/dv as an effective m easure of c o st effec tiveness for the reasons stated above.
As Nevada stated in our response to the initial FLM comm ent (Appendix C, Comment 17), NDEP evaluated th e control cos t , increm ental cost , and capital cost in com b ination and used a “leas t-co st envelope” to identify dom inant alterna tive s on a f acility by f acility bas i s. NDEP then evaluated th ese factors with th e estim a ted em issions reductions to determ ine BART for each source individually, as each source has unique char acteristics of cost a nd control efficiency. Nevada used the lim ited visibility modeling pe rform e d by NV Energy in conjunction with the

em issions re ductions to e s tim ate the v i sibilityim provem e nt based on the prem ise of a linear relationship between m o deled visibility and em i ssion ra tes (N PS agrees with th is pr emise in a subsequent comment).

The NPS ha s ignored the rem a inde r of NDEP’s response, which id entifies how capita l cost, cost per ton and increm ental cost in creas e , as well as the lim ited em issions reductions achieved for the next m o st stringent control option at Reid Gar dner. Capital cost increases by m o re than four tim es, cost per ton by m o re than twice, and incr em ental cost by m o re than seven tim e s, while

em issions are reduced by 542 tpy or 41 percent for unit 1. The clear br eaks in these factors support NDEP’s BART determ ination. NDEP’s ot her BART determ inations have sim ilar characteristics when considered on a source-by-source basis.
NPS goes on to advise against over reliance upon in crem ental cost, stating that “the increm ental cost of m oving f r om lower control to higher con t r o l will incr e a se as high e r contro l ef f i cienc i es are sought.” Exam ination of Table 1, “BART NO x 

### Cost Facto r s and Visib i lity Im provem e nt f o r NV Energy Facilities,” included in Appendix C of this SIP, dem onstrates that several m o re stringent control op tions have inc r e m ental costs lower thanthe next less stri ngent control option (e.g., for Tracy unit 1 see LNB w/ SNCR, LNB w/ FGR, and LNB w/ SCR; for Tracy unit 2 see LNB w/ S N CR; for Tracy unit 3 see LNB w/ S N CR and LNB w/ SCR; for Fort Churchill units 1 and 2 see LN B w/ SCR; for Reid Gardner units 1 and 2 see ROFA w/ Rotam i x; and for Reid Gardner unit 3 see LNB w/ OFA and SNCR). Therefore, the NPS pre m ise for not using increm ental cost is flawed.
NPS further proposes use of relative ratios of in crem ental costs and then points out the problem with this approach. However, examination of the problem atic da ta c ited by NPS suggests th ey have m i sinterpreted the data. NPS has apparentlypresented ratios of aver age cost effectiveness (in $/ton) rather than ratios of incremental cost ef fectivenes s for the op tion s they evalu a ted, based on the data presented in Table 1 of ND EP’s response to FLM comm ents. Appendix Y does not m e ntion the use of relative ratios of increm ental costs as a m easure of cost effectivenes s. Nevada is pleased th at N PS has reach ed the sam e conclus i ons regard ing BART control technolog ies as NDEP for the TracyGenerating Station and Fort Church ill Generatin g Station. However, Nevada is confused regarding N PS’ conclusions for BART at Reid Gardner Generating Station, as LN B with SCR was not one of the BART control options considered or

D-64

### presented by NV Energy or NDEP. If NPS m ean s LNB with OFA and S CR is BART for Reid Gardner, then NDEP dis a grees with the NPS assessm ent.
Based on the data in Table 1, refe renced above, installation of RO FA wi th Rotam i x at the Reid Gardner Generating Station has an estim ated capita l cost of nearly $8 m illion per unit, while LNB with OFA and SCR has capital costs of m o r e than $35 m illion per unit, 4.4 times as m u ch. Average cost effectiveness for the S CR option is 2.3 tim es as m u ch for units 1 and 2, and 1.7 tim es as m u ch for unit 3. Increm ental costs for the SCR option are 7.3 tim es as m u c h for unit 1, 6.8 tim es for unit 2, and 2.4 tim es as much for unit 3. Em issions reductions increase between the two options by 41 percent for unit 1, 39 percent fo r unit 2, and 104 percent fo r unit 3. Selection of the SCR option would increase th e facility’s capital cos t s by m o re than $81 m illio n to reduce NO x 

### e m issions by approxim ately 2,000 tons per year . Nevada deem s NDEP’s identification of BART as consistent with the breaks in cost effectiveness and visibility im provem e nt/em i ssions reductions (i.e., cost benefits), as well as the Appendix Y guidance.

To determ ine whether changes resulting from these comm ents regard ing co st and con t rol efficiencies m i ght significantly change NDEP’s conclusions, Nevada evaluated altern ative cost and em ission scenarios in cost analyses. This is notto say N e vada agrees with the values used in the altern ative scenarios cost analyses, but we did want to evaluate how reduced costs m i ght inf l uence N D EP’s BART determ ination f o r Reid Gar dner. T h is exer cis e will be ref e r

r ed to as the alternative cost analyses in the rem a inder of this docum ent.

Altera tive C o st Analys es NDEP included an econ o m i c analys is summary as Table 1 in each of NDEP’s BART determ ination reviews for our subject-to-BART sources. These reviews are included in Nevada’s RH SIP as Appendix B, BART Determination Support Documents 10 

### . Table 1 in NDEP’s econom i c analy s is for Reid Gardner 11 

### , is the basis of the alternativ e cost an alys es. For this exercise, Table 1 was m odi fied to incor por ate the lowe r em ission lim its (in lb/MMBtu) presented by NV Energy for the various proposed NO x 

### BART controls regardless of percent control efficiency (an approach preferred by NPS as noted in their follow-up comment 15) and is presented below as Table 2. Changing these NO x 

### em ission lim its addresses som e of t h e FLM comments directed at the control efficiencies used by NDEP in our original econom ic analyses.
In addition, NDEP evaluated lowe r control costs by reducing NV En ergy’s costs by 30 percent to address FL M comm ent s suggesting NV Energy’s cost s were inflated. S o, the alternative cost analyses for Reid Gardner, presented in Table 2 b e low, incorp orate h i gher percentage control efficiencies with lower em ission rates and lower cost s. Figure 1 presents the le ast co s tenvelop e analyses for Reid Gardner units 1, 2 and 3 based on NDEP’s alterna tive cos tanaly s es. Note that these an alys es are b a sed on baseli ne values determ ined by NDEP and that these values are not the sam e baseline values used by NV Energy.

Exam ination of Table 2 and Figure 1, below, s hows the results of NDEP ’s alternative co st analyses do not change our determ ination of BART for the three Reid Gardner units, even with

10 Available at ht t p : / /ndep

. n v

. g o v / b a qp/ pl anm odel i ng/ rhaze .ht m l

. 11 Nevada Division of Envir o nment a l Pr otection BART Dete rmination Revi ew of NV E n er gy’s Reid Gar d

ner Gene rat i n g St a t i on Uni t s 1, 2 an d 3



### D-65

### the greater em issions reductions and lower cost s suggested by the FLMs. LNB with OFA and SCR costs per ton of NO x 

### rem oved for all three units are 2.25 to 2.5 tim es greater than those for ROFA with Rotam i x. The LNB with OFA and S CR incremental costs per ton for units 1 and 2 are 7.5 to 8 tim e s greater than those for ROFA wi th Rotam i x, while the LN B with OFA and SCR increm ental costs for unit 3 are 2.5 tim e s those for ROFA wit h Rotam i x. The annual reduction in NO x 

### em is sions for LNB with OFA and SCR fr om units 1 and 2 is 56 percent (441 tpy for unit 1 and 472 tpy for unit 2), while the reduction for unit 3 is 65 percent (654 tpy) of the em issions for ROFA with Rotam i x. These factors, based on NDEP’s alternative cost analyses, coupled with a capital cost in crease of m o re than 400 percent for SCR controls, confirm NDEP’s selec tion of ROFA with Rotam i x as SO 2 

### BART for Reid Gardner.

D-66

### TABLE 2. REID GAR DNER ALT E RNATIVE COST ANALYSE S

R e id

- G a r d n e r U n it 1 Cu rr en t O p er a t i o n ( U n co n t ro l l ed

) RO F Aw / S C R LN B w / O F A & S C R RO F A w/ Ro t a mi x LN B w / O F A & SN C R LN B w/ O F A
C a

pi t a l C o s t $ 3 8 , 484 , 9 00 $35 , 0 4 8 , 0 00 $7, 8 8 4, 90 0 $ 6, 945 , 5 0 0 $4 , 4 4 8 , 000 F i r s tY e a r O & M C o s t $1, 31 3, 19 1 $ 1, 029 , 8 0 1 $ 613 , 9 5 2 $ 3 9 6 , 2 4 8 $ 8 0, 000 F i r s tY e a r D e bt S e r v i c e $4, 08 1, 55 5 $ 3, 717 , 0 5 1 $ 836 , 2 4 1 $ 7 3 6 , 6 1 2 $ 471 , 7 37 T o t a l A n n u a l C o s tR e d u c e d 30% $3, 77 6, 32 2 $ 3, 322 , 7 9 6 $1, 0 1 5, 13 5 $ 79 3, 00 2 $ 386 , 2 16

B a s e H e a t I np u t ( M MB t u ) 9 , 8 15, 313 T o ta l H e a t I

np u t a llo w e d( M M B tu ) 1 0 , 6 4 3 , 4 0 0 Ba s e e m i s s i o n s ( to n s ) 2, 26 7 N O x Re m o va l Rate % 8 4

. 8 % 84

. 8 % 6 5. 4 % 50

. 2 % 3 5. 1% N O x Re m o v e d ( T ons ) 0 1 9 23 1923 14 82 113 8 7 95 N O x E m i s s i on R at e ( T ons ) 2 2 6 7 3 44 344 7 8 5 112 9 1 4 7 2 N O x E m i s s i on R at e ( l b / M M B tu ) 0. 46 2 0

. 0 7 0

. 0 7 0

. 1 6 0

. 2 3 0

. 3 0 F i r s t Y e ar C o s t ( $ / ton r e m ove d ) $1 , 9 63 $1, 728 $6 85 $69 7 $ 4 8 6 I n c r e m e n t a l C o s t ( $ / t on ) $ 6 , 2 5 1 $5, 225 $6 47 $1, 18 4 $ 4 8 6

R e id

- G a r d n e r U n it 2 Cu rr en t O p er a t i o n ( U n co n t ro l l ed

) RO F Aw / S C R LN B w / O F A & S C R RO F A w/ Ro t a mi x LN B w / O F A & SN C R LN B w/ O F A
C a

pi t a l C o s t $ 3 8 , 484 , 9 00 $35 , 0 4 8 , 0 00 $7, 8 8 4, 90 0 $ 6, 945 , 5 0 0 $4 , 4 4 8 , 000 F i r s tY e a r O & M C o s t $1, 38 8, 07 1 $ 1, 078 , 5 5 1 $ 661 , 7 6 0 $ 4 1 8 , 6 5 7 $ 8 0, 000 F i r s tY e a r D e bt S e r v i c e $4, 08 1, 55 5 $ 3, 717 , 0 5 1 $ 836 , 2 4 1 $ 7 3 6 , 6 1 2 $ 471 , 7 37 T o t a l A n n u a l C o s tR e d u c e d 30% $3, 82 8, 73 8 $ 3, 356 , 9 2 1 $1, 0 4 8, 60 1 $ 80 8, 68 8 $ 386 , 2 16

B a s e H e a t I np u t ( M MB t u ) 10, 50 1, 7 4 9 T o ta l H e a t I

n p u

ta llo w e d ( MM B t u ) 10, 64 3, 4 0 0 B a s e e m i s s i on s ( t on s ) 2, 44 5 N O x Re m o va l Rate % 8 5

. 0 % 85

. 0 % 6 5. 6 % 50

. 6 % 3 5. 6% N O x Re m o v e d ( T ons ) 0 2 0 78 2078 16 05 123 8 8 70 N O x E m i s s i on R at e ( T ons ) 2 4 4 5 3 68 368 8 4 0 120 8 1 5 7 5 N O x E m is s i o n R ate ( lb/M M B tu ) 0

. 4 6 6 0 .0 7 0

. 0 7 0 .1 6 0

. 2 3 0 .3 0 F i r s t Y e ar C o s t ( $ / ton r e m ove d ) $1 , 8 43 $1, 616 $6 53 $65 3 $ 4 4 4 I n c r e m e n t a l C o s t ( $ / t on ) $ 5 , 8 8 3 $4, 885 $6 53 $1, 14 9 $ 4 4 4

R e id

- G a r d n e r U n it 3 Cu rr en t O p er a t i o n ( U nc o n tr o l l e d) RO F Aw / S C R LN B w / O F A & S C R RO F A w/ Ro t a mi x LN B w / O F A & SN C R LN B w/ O F A
Ca

p i t a l C o s t $ 3 8 , 484 , 9 00 $35 , 0 4 8 , 0 00 $7, 8 8 4, 90 0 $ 6, 945 , 5 0 0 $4 , 4 4 8 , 000 F i r s tY e a r O & M C o s t $1, 32 0, 11 4 $ 1, 000 , 8 9 3 $ 543 , 5 6 8 $ 3 4 5 , 9 7 0 $ 8 0, 000 F i r s tY e a r D e bt S e r v i c e $4, 08 1, 55 5 $ 3, 717 , 0 5 1 $ 836 , 2 4 1 $ 7 3 6 , 6 1 2 $ 471 , 7 37 T o t a l A n n u a l C o s tR e d u c e d 30% $3, 78 1, 16 8 $ 3, 302 , 5 6 1 $ 965 , 8 6 6 $ 7 5 7 , 8 0 7 $ 386 , 2 16

Ba s e H e a t I n p ut ( MMB t u ) 10, 06 3, 8 5 1 T o ta l H e a t I

np u t a llo w e d( M M B tu ) 1 0 , 8 3 6 , 1 2 0 B a s e e m i s s i on s ( t on s ) 2, 26 8 N O x Re m o va l Rate % 8 4

. 5 % 84

. 5 % 5 5. 6 % 49

. 0 % 3 3. 4% N O x Re m o v e d ( T ons ) 0 1 9 16 1916 12 62 111 1 7 59 N O x E m i s s i on R at e ( T ons ) 2 2 6 8 3 52 352 10 06 115 7 1 5 1 0 N O x E m i s s i on R at e ( l b / M M B tu ) 0. 45 1 0

. 0 7 0

. 0 7 0

. 2 0 0

. 2 3 0

. 3 0 F i r s t Y e ar C o s t ( $ / ton r e m ove d ) $1 , 9 73 $1, 724 $7 65 $68 2 $ 5 0 9 I n c r e m e n t a l C o s t ( $ / t on ) $ 4 , 3 0 4 $3, 572 $1 , 3 78 $1, 05 5 $ 5 0 9 NO x C o n t r o l

NO x C o n t r o l

NO x C o n t r o l

N o t e : Sh a d e d C o lum n s R e pr e s e n t B A R T , e m is s i o n r a t

e s f r om N V E n e r g y , a n d N V E n e r g y tota l a n n u a l c o s t s r e d

u c e d b y 30 %

.



### D-67

### FIGURE 1. ALTERNATIVE LEAST COST ENVELOPES FOR REID GAR DNER UNI TS 1, 2 AND 3*

R e i d

- G ar d

n e r U n i t 1 A l t e r n at i v e L e a s t C o s t E n ve l o p e

R

O F A w/ S C R

L N B w/ OF A & S CR

RO F A w / R

o t a m i x

L N B w/ OF A & S N CR LN

B w / O F A $0 $1 , 000 , 0 0 0 $2 , 000 , 0 0 0 $3 , 000 , 0 0 0 $4 , 000 , 0 0 0 $5 , 000 , 0 0 0 $6 , 000 , 0 0 0

0 5 0 0 100 0 150 0 2 000 25 00
To n s Re m ov e dAnnualCosts($)

R e i d

- G a r dn e r U n i t 2 A l t e r n at i v e L e as t C o s t E n ve l o p e

R

O FA w / SCR

L N B

w/ OF A & S CR

RO F A w / Ro t a m i x

L N

B w/ OF A & S N CR L N B w/ OF A $0 $1 , 000 , 0 0 0 $2 , 000 , 0 0 0 $3 , 000 , 0 0 0 $4 , 000 , 0 0 0 $5 , 000 , 0 0 0 $6 , 000 , 0 0 0

0 5 0 0 1 000 150 0 2 000 25 00
To n s R e m

o v

e dAnnualCosts($)

R e i d

- G ar dn e r U n i t 3 Al t e r n at i v e L e as t C o s t E n ve l o p e

RO F A w / S C R LN

B w / O F A & S CR

RO F A w / Ro t a m i x

L N

B w / O F A & S N CR L N

B w/ OF A $0 $ 1 ,0 0 0 ,0 0 0 $ 2 ,0 0 0 ,0 0 0 $ 3 ,0 0 0 ,0 0 0 $ 4 ,0 0 0 ,0 0 0 $ 5 ,0 0 0 ,0 0 0 $ 6 ,0 0 0 ,0 0 0

0 5 0 0 10 00 15 00 2 0 0 0 2 5 0 0
To n s R e m o v

e dAnnualCosts($)

*N OTE: R e vi sed usi n g l o we r N V Ene r gyc ont rol e ffi ci enc i es i n l b / M M B t uan d N V E n e r gyan nual costs reduce d by 30 pe rcent.



### Nevada’s alternative cos t analyses led NDEP to the sam e conclusions regarding the selection of ROFA with Rotam i x as BART controls for Reid Gardner. Nevada has also discussed the FLM’s

D-68

### em phasis on visibility criteria in the BART proc ess thereby dr iving the p r ocess by av ailab l e technology; however NDEP dee m s the BART proce ss a cost-benefit analys is. Finally, Nevada has identified a 2018 reasonable pr ogress goal that exceeds the uniform r a te of progress, indica ting s i gnif i cant p r ogress towar d the nation al vis i bility goal withou t the BART controls and/or lim its recomm ended by the FL Ms at Reid Gardner.
No changes were m a de to Nevada’s RH SIP as a result of these comm ent s

. COMMENT 8 (NPS-FWS p.5-6) NPS follow-up: NDEP shoul d present evidence to support its asse rtion that “ N DEP has c onsistently evaluated the economic factors as part of our evaluati on of proposed BART controls on a unit-by-unit basis...” NDEP explains that it used three fact ors (capital cost, average cost per ton, and incremental cost per ton), but doe s not tell how, or with what cr iteria, it applied them. As we noted in our previous follow-up, it appears that a consistent application of its criteria would have led to very differe nt determina t ions. If NDEP lacked th e modeling a nalyses it needed to produce an informed determination, it should have first obtained that information.
NDEP is correct in noting that the EPA BART Guid elines allow it to “choose not to analyze the other Class I areas any further as additional analyses might be unwarranted.” However, we believe that it is good public policy to at least cons ider the consequences of that choice. If the other Class I areas were so distant as to be essentially unaffected, NDEP’s choice could be justified. However, a sim p le insp ectio n of the mod e ling re sults presented b y NV Energy shows that, by evaluating impacts only at the closest Class I area, N D EP has ignored from 50% to 90% of the cumulative impacts at the Class I areas for which results are presented. Thus, NDEP has also ignored 50% to 90% of the benefits that w ould result from any reduc tions in emissions at thee fa cilities.
NDEP points to the “clear breaks” in the NV Energy Table 5-4 results as proof that the morestringent controls are too expensi ve. As we noted earlier, BART is not necessarily the most-costeffective option. And, as we have shown above, th ose “clear breaks” can be misleading unless placed into the proper perspective. We continue to disagree that this s hould be a determining factor if the more-stringent controls are still reasonably cost-effective.
We agree with NDEP that, “In general, there is a linear relationship between CALPUFF modeled visibility and emission rates. The vi sibility improvement resulting from BART installation is expected to be proportional to the difference in modele d annual emissions and the annual NDEP BART emi ssions.” However, if on e inspec ts th e results in NV Energy’s Table 3-2 for NO x 

### reductions and Table 5-4 for visi bility improvement, it can be seen that, if, for example, a 95 ton per year reduction due to LNBw/OFA at RGGS #3 produces an improvement of 0.407 dv at Grand Canyon, then a reduction of 1,136 tons per year after application of LNBw/OFA+SCR should produce more than th e 0.652 dv improvement presented by NV Energy. 1 

### If NDEP is to use the NV Energy data, it must insure that the data is valid and that it is properly presented and interpreted. It is apparent that the NVE data that NDEP is using requires further explanation, at the very least. (Footnot e 1: Similar inconsistencies can be found throughout the Reid Gardner analyses. For example, the N VE model results indicate that a one

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### ton/yr re duc tion by LNB will improv e visib i lity 7. 5 times as m u ch as a one ton reduc tio n resulting fo r m LNB+SCR.)
NDEP follow-up response: NDEP has c onsistently evaluated the proposedBART controls on a unit-by-unit basis by identifying the clear breaks in cost-benefit ba sed on cost effectiveness and visibility im prove m e nt. Nevada utilized capita l cost, average cost per ton, and increm ental cost per ton as

econom ic fa ctors and m odeled visib ility or em issions redu ctions as vis i bility im provem e nt factors. NDEP does not agree with the use of th e optional cost effectiveness m e tric of $/dv in our determ inations as recommended by the FL M community. This position is based on Nevada’s analyses presented in NDEP’s follow- up response to NPS’ follow-up response to Comm ent 7. Other states have also expressed reservations regarding the use of $/dv as a

m easure of cost effectiveness.
As NDEP stated in Nevada’s initial responses to FLM comments, section 5.6 of Neva da’s RH SIP discusses the visibility im provem e nt resulti ng from BART i m ple m entation in N e vada. In addition, as NDEP noted in Neva da’s initial responses to FLM comments, Chapters 5 of NV Energy’s B A RT determination reports discuss th e dispersion m odeling results as well as presenting tables and figures docum enting visibili ty im provem e nt at all Class I areas within 300 km of the f a cilities. All these da ta w e re considered in NDEP’s BART determ inations. However, Nevada did not rigorous ly utilize $ / dv as a cost effec tiv eness m easure as this comm ent
seem s to suggest we should. NDEP deem s cost bene fit rather than visibility im provem e nt as the determ ining factor for identifying B A RT, contraryto NPS philosophy. This is an area where NDEP and NPS m u st a g ree to disagree.
NPS has apparently m i sinterpreted the data c ited from the NV Energy reports regarding the modeled vis i bility im provem ent resulting from each ton of NO x 

### reduction. NDEP has com p iled and analyzed the cited d a ta, as p r esented in Tab l e 3. W e exam ined the changes from baseline for each control option, as w e ll as the ch anges betwee n options. Our analysis shows the d e ciview im prove m e nt per ton of NO x 

### rem ove d is consistent between the options out to four decim a l places. NDEP deem s these data to b e not only v a li d, bu t als o properly p r esented and interpreted.

TABLE 3. VISIBILITY IMPROVEM ENT PE R TON OF NO X 

### REDUCTION AT REID GAR DNE R

98t h p er c e n til e de l t a d eci v i e w
r e du ct i o n

(d v) v i s i b i l ity ch an ge fr

om ba s e l i n e

(d v) vi s i b i l i t y ch ang e be t w een op t i o n s

(d v) an nu al

em i s si o n s

cha ng e fr

o m ba s e li ne

(t

p y

) an nu al

em i s si o n s

ch ange be t w e e n op t i o n s

(t

py

) v i s i b i li ty i m pr ove m e nt

pe r t

o n
r e m o ve d f r o m ba s e l i n e (d

v / t

o n

) vi s i b i l i t y i m

pr

ov em en t p e r t o n r e m o ve d b et w e e n op t i on s (d

v/

ton )

Ba s e 0. 3 8 6 LN B w / O F A 0

. 4 07 0. 0 2 1 0

. 021 95 95 0

. 00 02 2 0

. 0 0 022 LN B w / O F A an d SN C R 0. 4 8 5 0

. 0 99 0. 078 43 4 3 3 9 0

. 00 02 3 0

. 0 0 023 RO FA w

/ R o t a m i x 0

. 5 14 0. 1 2 8 0

. 029 55 6 1 2 2 0

. 00 02 3 0

. 0 0 024 RO FA w

/ SC R 0

. 6 52 0. 2 6 6 0

. 138 1 1 3 6 58 0 0

. 0 0 0 2 3 0. 00 024 L

N B w / O F A a

n d S C R 0

. 6 5 2 0

. 26 6 0 11 36 0 0

. 0 0 0 23 na



### D-70

### No changes were m a de to the draft RH SIP as a result of these follow-up comments.
COMMENT 9 (NPS-FWS p.6): Comments o n Re id Gardner BART Determ ination, Sulfur Dioxide (S O 2 

### ) NPS follow-up: Reid Gardner is subject to BART, and BART is a federally-enforceabl e emission limit. NDEP should provide the 98 th 

### percentile values on which it bas ed its BART limit. And, because NDEP believes tha t operating conditions an d/or coalqu ality will ch ange, it sho u ld iden tify those changes and include them in its analysis so that those assumptions can be evaluated by others. 2 

### (Footnote 2: NDEP should also explain why su ch changes in operations would not trigger new source review requirements.)
NDEP follow-up response: Please see NDEP’s response to USEPA comm ent 2, above, where NDEP explained that Nevada conducted addition a l ev aluation of NV Energy’s BART Ana l ysis for Reid Gardner Station Unit 1 and the analyses for units 2 and 3, as well as anal ysis of the em issions data collected under the auspices of 40 CFR Part 60. These effo rts lead NDEP to establish a revised SO 2 

### BART lim it f o r Reid Gardner at 0.15 lb/MMBtu. Text, figures and tables in this SIP as described in Nevada’s response to USEPA comment 2, as well as text in NDEP’s BART re view for Reid Gardner were modified to reflect the change in SO 2 

### BART e m i ssion lim its for Reid Gardner and its

ram i f i cation s

. In addition, please see N e vada’s response to NPS follow-up Comm ent 6 above, which discusses the operational challenges presented by the inst allation of retrofit tec hnology at Reid Gardner unit 4.
Operational conditions related to boiler draft balance and/or coal quality are not perm it conditions. As such, m o dification of these ope rational conditions does not trigger new source review requirem e nts. No changes were m a de to Nevada’s draft RH SIP a s a result of this comment.
COMMENT 10 (NPS-FWS p.6) NPS follow-u p : NDEP should duly resolve this during the BART process. [ N O T E : “ T h i s ” r e f e r s t o a nN P S i s s u e with the av e r aging pe rio d s f o r the SO 2 

### BART e m ission lim i t s at Reid-G ardner.]
NDEP follow-up response: NDEP has a ddressed a sim ilar comment in Nevada ’s response to USEPA Comm ent 2 in section 2.2.2.2 of this appendix.
NDEP expects NV Energy will ope r a te th e post- BA RT Reid Gardner Ge nerating Sta t ion m u ch as it h a s his t orica lly and will ach ieve actua l em i ssion ra tes con s isten twith the highly ef f i cien t
recen t operational his t ory of the faci lity, which h a s achieved the low SO 2 

### em ission rates noted by the FLMs. It is im probable that the f acility will have em issions as high as 0.15 lb/MMBtu for extended periods or operate atfull capacity year round.
No changes were m a de to the draft RH SIP as a result of this comment.

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### COMMENT 12 (NPS-FWS p.7) NPS follow-u p : Condensible PM is generally understood to be a significant component of PM emissions from fossil-fuel-fired EGUs, and the CALPUFF mode l us ed by NV Energy to model emissions is capable of, and was used for modeling condensible PM emissions. NDEP is incorrect in its assertion that “there is no post-com bustion technology to directly control condensable particulate emissions.” Wet electrostatic precipitators are co mmonly installe d for this purpose, and reagents have been recently develope d to su ppress the fo rmation of S O 3 

### which leads to emissions of H 2 

### SO 4 

### . NDEP follow-up response: USEPA is c u rrently im plem enting the ne w source review (NSR) program for PM 2. 5 

### . There are a

num b er of outstanding issu es re lated to NSR f o r PM 2. 5 

### . For instance, there is little o r no inform ation on PM 2. 5 

### emissions from stationary sources, re ference test m e thods have not been prom ulgated, and the reference test m e thod that was developed for condensable PM was flawed. Currently th ere is a la ck of necessary tools to estim ate e m issions of PM 2. 5 

### and related precursors. Sim ilar issues exist for condensable PM 10 

### . Until USEPA has determ ined how BACT and LAER, and other as pects of NSR will be ha ndled f o r co ndensables a nd precurso r s, NDEP deem s it unreasonable to consider condensable PM under BART.
Reid Gardner recently installed pul se jet fabric filter as part of an environm ental upgrade project for units 1, 2 and 3 under the conditions of a consent decree between USEPA, NDEP a nd NV Energy. Fabric filt er is BART for PM 10 

### at Reid Gardner. T h e pot ential level of em issions reduction f o r ele c tro s ta tic prec ipitato r s is no t as g r eat as the fabric filter an d was elim inated from further consideration as BA RT for Reid Gardner.
No changes were m a de to Nevada’s draf t RH SIP as a resu lt of this comm ent.
COMMENT 13 (NPS-FWS p.7): Nitrogen Oxides (NO x 

### ) NPS follow-up: While true, the generalities presented by NDE P do not address the question of why a specific boiler (R GGS #3) should be allo wed to emit more NOx

### after installation of similar BART controls than similar boilers at R GGS w ith higher pre-BART emissions and similar BART controls. And, we still do not see h o w the h i gh er emiss i on rates for RGGS Unit 3 are furth e r explained in NDEP’s response to the next USDOI comment.
NDEP follow-up response: NDEP research has id entified incons istencie s between the NV Energy Reid Gardner BART reports and operating perm it regarding the dates of comm ission and when the three B A RT units were placed into operation. Reid Gardner unit 1 was m a nufa c tured in 1965, unit 2 in 1968, and unit 3 was m a nufactured in 1976, based on inform a tion from the perm its. The differences in

m a nufacture date m a y account for som e of the variability in controlled N O x 

### e m ission rates exhibited by the three units.
In addition, based on NV Energy’s experience withinstallation of the R O FA syste mon Reid Gardner unit 4, described in Nevada’s respons e to follow-up comm ent 6 above, NDEP is not certain th at the m a nufacturer’s guarantees are necessarily achi evable. The tuning of ROFA on unit 4 has taken m u ch longer than originally anticipated, and the guaranteed value has been

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### difficult to obtain. The engineering team has ha d to continuously revise their approach to installation of the RO FA, including changing coal burner components and air ducting for the boiler. NV Energy’s operational ex perien ce with ROFA was a fact or in setting the higher BART

em ission lim it for unit 3.
No changes were m a de to Nevada’s draf t RH SIP as a resu lt of this comm ent.
COMMENT 14 (NPS-FWS p.7) NPS follow-u p : We disagree that “...assumptions presented by NV Energy do not vary significantly from engineer ing norms...” Differe nces between 6% and 15% contr o l, and betw een 24% an d 63% control are significant. G ood combustion controls are the foundation for any NO x 

### reduction strategy. If that foundation is not strong, then the add-on controls will be hampered in their effectiveness and their costs will increase.
NDEP follow-up response: This NPS follow-up com m e nt refers to control effi cien cies for com bustion contro ls, sp ecif ica lly LNB with OFA at Reid Gardner. T h e BART control technology identi fied by NDEP for Reid Gardner, ROFA with Rotam i x, combines com bus tion con t ro l with reag ent injection and has control efficiencies twice thos e of LNB with OFA and correspondingly lower em ission rates. This comm e n t appears to be m oot in light of the B A RT control technology selected by NDEP. No changes were m a de to Nevada’s draf t RH SIP as a resu lt of this comm ent.
COMMENT 15 (NPS-FWS p.7) NPS follow-u p : NDEP has based its analyses of the costs of co mbustion controls plus SCR on the assumptions that th is co mbination of controls ca n ac hieve an nual emissio n rates no lo wer than 0.083 – 0.098 lb/mmBtu. It appears that NDEP arrived at these emission rates counter to the approach used by NVE in which NVE estimated the emission rate that was achievable and then calculated the corresponding reduction efficien cies. Although we believe tha t NVE has underestimated the ability of SC R to achieve lower emissions, we agree with its approach and it the approach taken by the overwhelming majority of BART sources across the nation.
Instead, NDEP used the “artificially ” calculated control efficienci es that resulted from NVE’s emission estimates, and then applie d those artificial values to its escalated bas eline emission and heat input scenarios. As a result, not only are the NDEP em iss i on rates higher than the 0.07 lb/mmBtu rate presented by NVE, they are hi gher than the em ission rates demonstrated in practice (as illus t rated b y the updated CAM data we are submitting) and higher than the vendor guarantees. 3 

### NVE and NDEP should re-evaluate SCR on th e basis that it can achieve an annual emission rate of 0.05 lb/mmBtu. (Footnote 3: For example, Minnesota P o wer has stated in its Taconite Ha rbor BART analysis that “The use of an SCR is expected to a c hieve a NO x emission rate of 0.05 lb/mmBtu based on recent emissi on guarantees offered by SCR system suppliers.”)
NDEP follow-up response: NDEP has e v aluated lower em ission rates (i.e., higher control efficiency percentages) and reduced co sts in altern ative cost an alyses of BA RT controls for Reid Gardner, as described in NDEP’s response to NPS follow-up comment to Comm ent 7, above

. The alternative cost analyses led NDEP to the sam e determ ination of BA RT for Reid Gardne r, RO FA with Rotam i x.

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### COMMENT 16 (NPS-FWS p.7-8) NPS follow- up: The Boardman costs rep r esent an un usual situati on in which a $40 millio n capita l cos t would be included for modifica tion of the bo iler to redu ce outlet temperatures to a range that w ould accommodate SCR. 4 

### Unless NVE can show that it would experience unusual costs, then we believe that the cost values cited (and again incl uded) are fair representations of typical SCR costs. (Footnote 4: NDEP can learn more about this at http://www.deq.state.or.us/aq/haze/pge.htm)

NDEP shoul d also recognize that the “average and median total capita l investment of $320 and $301/kW for SCR and $346 to $334/kW for combusti on control plus SCR ” is based almost entirely on data presented by sources that ha ve rejected SCR, and thus have a large financial intere st in c onvincing th eir re gulatory agencies to agree. Wh en we compare those industry estimates to the “real-world” data compiled for the Electric Power Research Institute and the Boardman reports, we suspect that the industry co st data to which NDEP referred is inflated. We hope that N D EP would exercise cau tion in evalu ati ng data from sources with clea r conflicts o f interest. In addition, we suggest that NDEP consider the inform ation presented by Minnesota Power to the Minnesota Public Utilities Commi ssion in which it estimated that addition of SCR would cost $205/kW at is Clay Boswell unit #3.
NDEP follow-up response: NDEP has determ ined BART on a case-by-case basis inconsideration of the f actors lis ted in Part 51 Appendix Y guidance. In addition, NDEP conducte d alternative cost analyses to evaluate whether inflated cos t s an d/or lower achiev able em ission rates would change our BART determ inations for Reid Gardner. T h e alterna tive cost analyses, described above under Comment 7, led NDEP to conclude our initia l BART determination was sound.

Because Nevada determined BART on a case
- by -case b a sis, the cost inform ation presented by NPS is of pa ssing interest. However, NDEP does note NPS has a tendency to present those cost data in supp ort of their p o sition s while dis a vow in g those data that don ’t su pport th eir p o sition s , although the referenced cost data compilation w a s conducted by NPS. The NPS points NDEP directly to cost data for one facility to s upport S CR as BART, while, as they state above, m a ny other facilities have rejected SCR as BART. NDEP asserts th at it does ex ercis e cau tio n in evaluating data from outside sources.
No changes were m a de to Nevada’s RH SIP as a result of this comment.
NPS follow- up: It appears that NDEP has somehow concluded that our “NPS version of corrected OA QPS Cost Manual...” spreadsheets represent some radica l revision of the EPA OAQPS Control Cost manual approach recom m ended by the BART Gu idelin es. Instead, the “corre ction” to which the file’s title refers is in the origi nal version of that work book that used the example problem in the Cost Manual as a check. In the process of deve loping the workbook, it was discovered that some errors had occurred in the Cost Manual’s presen tation of its example, and those errors were corrected (with th e coop eration o f

OAQPS) . We suggest tha t NDEP become more familiar with the methods employed by the Cost Manual and the workbook based upon it. If NDEP then finds that there really is an error or deviation in the workbook, we would be pleased to work with NDEP (and OAQPS) to correct it.

D-74

### We are unaware that the OAQPS Control Cost manual must be “properly vetted through a public pro c ess” in order for NDEP to accept the science inherent in its methods. And, while we have made our workbook available to all as an ai d toward evaluating the costs of SCR
, if NDEP wishes to use a different approach, it is welcome to do so, provid ed that it presents adequate rationales, explanations, and justification.
NDEP follow-up response: NDEP appreciates NPS explaining the changes it m a de to the Cost Manual and the workbook based upon it. This is the first explanation we ha ve seen of how the NPS version of the corrected OAQPS Cos tManual was m odi fied in conjuncti on with OAQPS. Can NPS point NDEP to OAQPS’ announcem ent and docum e n tation of th ese changes for NDEP re view? NDEP is skeptical of utilizing undocum ented resources from outside sources without further evaluation.

NPS concurs with NDEP’s BART t echnology determ inations, as stated in its follow-up to Comm ent 7, for all Nevada’s subject-to-BART sources except Reid Gardner. So these comments are m oot, except for Reid Gardner. NDE P has evaluated how lower costs m i ght affect our BART determ ination f

o r Reid Gardner with alternative cos tanaly s es, d e scrib e d in NDEP’s response to NPS’ follow-up comm ent to Comm e n t 7. The alternative cost analyses confirm NDEP’s determ ination of BART technology for Re id Gardner. No changes were m a de to Nevada’s RH SIP as a result of this comment.
NPS follow-up: The data available to N P S lead us to believe that costs for a typical SCR installation range from $50 – 250/kW. NVE has provided no documentation or justification for its mu ch higher costs. If NVE cannot provide the documentati on and justification to support it s estimates, then it should use the Cost Manual approach to generate estimates that are consistent and transparent. We are simply doing exactly that.
NDEP follow-up response: The Part 51 Appendix Y guidance st ates that BART is a case-by-cas e determ ination. The use of $/kW is an optional m easure of cost effectivene ss not identified in Appendi x Y. In addition, see NDEP’s follow-up response to the NPS follow-up to Comm e n t 7 above, where NDEP references its alternativ e cost an alys es. No changes were m a de to Nevada’s RH SIP as a result of this comment.
NPS follow-up: We believe that BART decisions shou ld be made in the context of other d e cisions made by a particular state, and in the context of decisions made by other states, in much the sam e manner as Best Available Control Technology determinat ions. This promotes th e concept of the “level playing field.” We also encourage states to consider the unique circumstances particular to a given source and its impacts upon Class I areas in its vicinity. At the very le ast, a state should be internally consistent in its determinations, or provide information describing any apparent inconsis tenc ies.
NDEP follow-up response:

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### As NDEP stated in our response to the NPS follow-up comm ent above, NDEP views BART as a case-by-case determ ination, consistent with Appendix Y guidance. NDEP has consistently determ ined BART through identification of clea r breaks in the cost effectiveness m easures identified in Appendix Y guidance and visibi lity improvem e nt /em i ssions reductions at the affected Class I areas. Nevada notes thatNPS concurs with NDEP’s BART technology determ inations for all but one of Neva da’s sub j ect-to -BART facilities.
No changes were m a de to Nevada’s RH SIP as a result of this comment.
COMMENT 17 (NPS-FWS p.8) NPS follow-u p : Although NDEP did not address our comments, it is correct in noting that the EPA BART Guidelines a llow it to “choose not to analyze the other Class I areas any further as ad ditiona l analyses might be unwarranted.” However, we be lieve tha t it is good pu blic po licy to at least consider the consequences of that choice. If th e o ther Class I areas were so distant as to be essentially u naffected, N D EP’s choice could be justified. Ho wever, a sim p le insp ectio n of the modeling re sults presented by NV Energy in T able 5-3 of its s ubmittals sh ows that, by only evaluating impacts at the Grand Canyon, NDEP has ignored half of the cumulative impacts at the five Class I areas for which results are pres ented. Thus, NDEP has also ignored half of the benefits that would result from any reductions in emissions at RGGS.
NDEP follow-up response: This comm e n t duplicates a portion of the NPS follow-up comm ent to Comment 8; see NDEP’s follow-up response to C o mm ent 8.
The origin al FLM Comm ent 17 suggests cos tbe nchm arks based on the $/dv cost effectiveness

m e tric. As NDEP has noted above, BART is a cas e-by-case determ ination and is not determ ined by cost benchm arks at other facilities. NDEP has chosen not to use the optional $/dv cost effectiveness m e tric for the reasons discusse d in our response to NPS follow-up comm ent to Comm ent 7.
In addition, NDEP disagrees with the NPS statement that Nevada did not consider visibility im prove m e nt in its BART determ inations. NDE P discusses visibility im provem e nt resulting from the implem entation of BART at Nevada sources in section 5.6, “V isibility Improvem e nt Due to BART Im ple m entation” of Nevada’s RH SIP. In the cases where lim ited m o deling was perf orm e d, NDEP utiliz ed em issions reductions in li eu of vis i bility im provem ent, since m odeled visibility im provem e nt is proportional to em issi on rates. F i nally, regional visibility m odeling dem onstrates Nevada’s 2018 reasonab le progress goal for Jarbidge is below the uniform rate of progress and that Nevada’s em ission reductions ar e consistent with our share of visibility im pair m e nt at Class I areas in ad jacent states.
No changes were m a de to Nevada’s RH SIP as a result of this comment.
NPS follow-up: We disagree and suggest that NDEP reconsider th e cost information provided by NVE by taking a fresh look at the data we have provided, 5 

### as well as its background. While it is true that it is the role of the states (or EPA when the state fails) to establish BART, that does not preclude DOI

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