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S U B J E C T: C l a r i f

i c a t i o n o f C h o ll a a n d C o r o n a do E mi ss i o n R a t e s U s e d

F R O M: S c o tt B o h n i n g

A i r D i v i s i o n

, A I R

- 7

E P A R e g i o n 9

T O: A

r i z o n a R e g i o n a l H aze F I P D o c k e t E P A

- R 09

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- 2012

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T h i s m e m o r a n d u m d o c u m

e n t s a c o n f

e r e n c e c a ll b e t w ee n

E P A R e g i o n 9 a n d A E C O M

, a

c o n s u l t i n g f i r m

, c o n ce r n i ng e mi ss i o n s d a t a r e li e d up o n b y E P A i n p r o p o s i n g a F e d e r a l

I m p l e m e n t a t i o n P l a n f

o r B e s t A v a i l a b l e R e t r o f

it T ec h n o l og y ( B A R T ) u n d e r t h e R e g i o n a l H aze

R u l e f o r s e v e r a l f

a c i l i t i e s i n A

r i z o n a . T h e c a l l o c c u rr e d a t n o o n P D T o n

T h u r s d a y

, J u l y 26

, 2012

. A t t e n d i n g f

r o m E P A w e r e S c o tt B o h n i ng a nd E ug e n e C h e n

. A E C O M w a s r e p r e s e n t e d b y

R o b e r t P a i n e a n d S e e m a n t i n i D e s h p a n d e

. A E C O M h a d e

- m a il e d qu e s t i o n s a b o u t t h e s o u r c e o f

b a s e l i n e e mi ss i o n r a t e s f

o r C h o ll a P o w e r P l a n t a n d C o r o n a d o G e n e r a t i n g S t a t i o n

, a s u s e d f o r a i r

qu a l i t y m o d e l i ng a n d i n ce r t a i n c o s t c a l c u l a t i o n s . E P A d i s c u s s e d t h e d a t a s o u r ce s r e li e d up o n

a n d t h e s e l ec t i o n o f p a r t i c u l a r e m i s s i o n r a t e s

, a n d a l s o w h e r e c l a r i f i ca t i o n o f t h i s i ss u e s c o u l d b e

f ou n d i n E x c e l s p r ea d s h ee t s c o n t a i n e d i n t h e d o c k e t f o r t h e p r o p o s a l

.

A E C O M ’ s e

- m a i l q u e s t i o n s

, a n d E P A ’ s e

- m a i l e d r e s p o n s e s a r e c o n t a i n e d i n a n a tt ac h m e n t t o

t h i s m e m o r a n d u m

.R E : que s t i on s abou t ba s e li ne e m i ss i on r a t es

Sc o tt B ohn i ng t

o: P a i ne

, B ob 08 / 03 / 2012 01 : 27 PM

C c: E ugene C hen

, "D e s hpande

, S ee m an t i n i"

B ob

-

I m ean t t o ge t t h i s r e s pon s e t

o y ou ea r l y i n t

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o r no t ge tt

i ng t h i s done be f

o r e now

. I n

an y c a s e

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h i n k t h i s c o v e rs p r

e tt y m u c h t he s a m e c l a r i f

i c a t i on s a s ou r c on f

e r en c e c a ll on J u l y 27 t

h

, s o

hope f u ll y y ou go t wha t y ou needed t hen

. T h i s r

e s pon s e ha s m o r

e s pe c i f i cs on l o c a t

i on s i n s o m e

s p r ead s hee t

s i n t he do ck e t f

o r ou r Ar i z ona r

eg i ona l ha z e FI P p r

opo s a l.

> Co r onado

... M

ode l ed B a s e li ne Em i ss i ons

>

> F o r Un i t 1

,... W e f

ound t ha t a h i ghe r da il y N O x e m i ss i on r a t e

> ( 35

, 276 l b /

da y) o cc u rr

ed on 6 / 11 / 2009.

EPA r e s pon s e : A ll o f t

he s e C AM D e m i ss i on s da t a a r e c on t a i ned i n t

he s p r ead s hee t " A Z M

a x Em i ss i on

Da t e s

. x l sx "

, a v a il ab l e i n t

he do ck e t. G ene r

a ll y EPA a v o i ded da t

a t ha t we r e w i t h i n a f ew m on t h s o f t he

i n s t a ll a t i on o f c on t

r o l equ i p m en t, be c au s e ad j u s t m en t s o f p l an t ope r

a t i on a r e needed t

o a cc o mm oda t

e t he

new equ i p m en t, and t

e m po r a r il y t he r e c an be ano m a l ou s l y h i gh e m i ss i on s f o r s ho r t pe r i od s

. T he r

e i s

s o m e p r o f e ss i ona l j udg m en t i n v o l v ed i n t h i s c ho i c e

. W h il e EPA ag r ee s t ha t e m i ss i on s on 6

/ 11 / 2009 we r

e

t he m a x i m u m N O x e m i ss i on s po s t

- i n s t a ll a t i on

, t h i s wa s du r i ng an ano m a l ou s l y h i gh e m i ss i on pe r i od

. T h i s c an be s een f

r o m t he e m i ss i on s i n t

he s p r ead s hee t du r i ng t

ha t f i rs t m on t h ; e m i ss i on s v a ry w

i de l y

. EPA a l s o a v o i ded i nd i v i dua l da ys t ha t appea r

ed t o be " s p i k e s " o f h i gh e m i ss i on s

, s i n c e t he y m a y no t

r ep r e s en t t y p i c a l ope r

a t i on s

. T he c ho s en da y i s t he 5 t h h i ghe s t po s t

- i n s t a ll a t i on

, and i s nea r t

he l e v e l o f

o t he r h i gh s s een du r i ng t he po s t

- i n s t a ll a t i on pe r i od

.

> Cho lla

>

> Un i t 1 M

ode l ed B a s e li ne Em i ss i on s

... W e f ound t ha t h i ghe r da il y

> N O x e m i ss i on s ( 9

, 428 l b / da y) o cc u rr

ed on 1 / 30 / 2010.

>

> Un i t 2 M

ode l ed B a s e li ne Em i ss i on s

... W e f ound t ha t h i ghe r da il y

> N O x e m i ss i on s ( 31

, 454 l b / da y) o cc u rr

ed on 6 / 14 / 2008.

>

> Un i t 3 M

ode l ed B a s e li ne Em i ss i on s

... W e f ound t ha t h i ghe r da il y

> N O x e m i ss i on s ( 26

, 226 l b / da y) o cc u rr

ed on 7 / 2 / 2009.

EPA r e s pon s e : C AM D da t

a f o r Cho ll a a r

e a v a il ab l e i n t

he do ck e t; t

he y a r e s o r t ed f r o m h i ghe s t t

o l owe s t,

w i t h t he t op t en i nd i c a t

ed i n g r een

, and t

he da y s e l e c t

ed f o r m ode li ng s hown i n r

ed

. F o r a ll f

ou r un i t s

, EPA c ho s e t

he h i ghe s t da y po s t

- LN B i n s t

a ll a t i on t ha t d i d no t appea r t

o be an ano m a l ou s l y h i gh s p i k e da y

.

F o r un i t 1

, EPA r

e j e c t ed 1 / 30 / 2010 and 10

/ 11 / 2008 a s be i ng i s o l a t

ed s p i k e s

, l ea v i ng 1 /

26 / 2010 a s t

he

h i ghe s t e m i ss i on da y ( " U113 " t ab o f s p r

ead s hee t " A Z

_ BA R T

_ s ou rc e s

_ a ll

- T a sk 7

- 8

_ 2012

- 06

- 10

. x l s " ).

F o r un i t 2

, EPA r

e j e c t ed 6 / 13 / 2008 and 9

/ 6 / 2008 a s be i ng i s o l a t

ed s p i k e s

, l ea v i ng 6

/ 29 / 2009 a s t

he

h i ghe s t e m i ss i on da y ( " Cho ll a

_ N O x po s t -c on t r o l s o r t " t ab o f " A Z M

a x Em i ss i on Da t

e s

. x l sx ")

F o r un i t 3

, t

he LN B i n s t

a ll a t i on da t e wa s 5 / 14 / 2009

, a cc o r

d i ng t o C AM D ; e m i ss i on s v a r i ed e rr a t i c a ll y f o r

s o m e t wo m on t h s a ft e r t h i s da t e

, and we r

e e xc l uded b y EPA

. A l s o e xc l uded we r e 2 / 11 / 2010 and

2 / 12 / 2010 a s be i ng pa r

t o f an ano m a l ou s s p i k e

. T h i s l e ft 11 / 24 / 2010 a s t

he h i ghe s t, a v a l ue t

ha t o cc u rr

ed

du r i ng a pe r i od o f gene r a ll y h i gh e m i ss i on s du r i ng No v e m be r 2010.> Un i t 2 Co s t A na l ys i s

... we c a l c u l a t e t he a v e r age annua l N O x e m i ss i on r a te

> f r o m Un i t 2 t

o be 0

. 2905 l b / MMB tu

>

> Un i t 3 Co s t A na l ys i s

... we c a l c u l a t e t he a v e r age annua l N O x e m i ss i on r a te

> f r o m Un i t 3 t

o be 0

. 2551 l b / MMB t u.

>

> Un i t 4 Co s t A na l ys i s

... we c a l c u l a t e t he a v e r age annua l N O x e m i ss i on r a te

> f r o m Un i t 4 t

o be 0

. 262 l b / MMB t u.

EPA r e s pon s e : B a s e li ne e m i ss i on f a c t o rs i n N O x l b /

MMB t u we r e t a k en d i r e c t l y f r o m C AM D r

epo r t s o f

annua l e m i ss i on s

, r

a t he r t han f r o m a v e r ag i ng da il y C AM D da t

a

. B e c au s e EPA f

o c u ss ed on t

he pe r i od

when LN B wa s f

u ll y i n p l a c e a t Cho ll a

, 2011 v a l ue s we r e u s ed

. F o r Cho ll a un i t s 2

, 3

, and 4

, t

he C AM D

annua l v a l ue s a r

e 0

. 295

, 0

. 254

, and 0

. 260 l b / MMB t u N O x

, r e s pe c t i v e l y.

Le t E ugene o r m e k now i f y ou need an y t h i ng e l s e.

- Sc o tt B ohn i ng

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=+=+=+=+=+=+=+=+=+=+=+=+=+=+=

" Sc o tt B ohn i ng " < bohn i ng

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. go v>

U

. S

. EPA Reg i on 9

, A I R -7

415 / 947

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a x- 3579

F r o m: " P a i ne

, B ob " <bob

. pa i ne @ ae c o m

. c o m>

T o: E ugene C hen / R 9 / U SEPA / U S @ EPA

, S c o tt B ohn i ng / R 9 / U SEPA / U S @ EPA

C c: "D e s hpande

, S ee m an t i n i " < S ee m an t

i n i

. D e s hpande @ ae c o m

. c o m>

D a t e: 07 /

26 / 2012 11 : 19 AM

S ub j e c t: R E : que s t i on s abou t

ba s e li ne e m i ss i on r

a t es

E ugene and S c o tt, he r e a r e t he que s t i on s t ha t w e w an t t o c o v e r i n ou r c a ll t oda y.

C o r on a do

M od e l e d B a s e li n e E m i ss i ons

F o r U n i t 1

, EPA u s ed a ba s e li ne pe r i od f r o m M a y 16

, 2009

– D e c 31

, 2010 s i n c e t he un i t w a s

r e t r o f i tt ed wi t h l o w N O x bu r ne r s ( L N B s ) t ha t be c a m e ope r a t i ona l on M a y 16

, 2009

. F o r

ba s e li ne m ode li ng

, EPA u s ed m a x i m u m da il y N O x e m i ss i on s ( 33

, 208 ) f r o m U n i t 1 t ha t

o cc u rr ed on 11 / 3 / 2010

. W e f ound t ha t a h i ghe r da il y N O x e m i ss i on r a t e ( 35

, 276 l b / da y )

o cc u rr ed on 6 / 11 / 2009

.

B y t he w a y

, w e ag r ee wi t h EPA ’ s ba s e li ne e m i ss i on s f o r C o r onado U n it 2

, ba s ed upon t he

m a x i m u m ba s e li ne hea t i npu t o f 106

, 706

. 7 MM B t u / da y t o o cc u r on 9 / 5 / 2008.

C ho lla

U n i t 1 M od e l e d B a s e li n e E m i ss i ons

F o r U n i t 1

, EPA u s ed a ba s e li ne pe r i od f r o m J an 1

, 2008

– D e c 31

, 2010

. F o r ba s e li ne

m ode li ng

, EPA u s ed m a x i m u m da il y N O x e m i ss i on s ( 8

, 392 l b / da y ) f r o m U n i t 1 t ha t o cc u rr ed on

2 / 7 / 2008

. W e f ound t ha t h i ghe r da il y N O x e m i ss i on s ( 9

, 428 l b / da y ) o cc u rr ed on 1 / 30 / 2010

.U n i t 2 M od e l e d B a s e li n e E m i ss i ons

U n i t 2 w a s r e t r o f i tt ed wi t h L N B s i n ea r ly 2008

. T he r e f o r e

, EPA u s ed a ba s e li ne pe r i od f r o m

2 / 29 / 2008

- 12 / 31 / 2010 , t o i n c l ude t he pe r i od w hen t he L N B s w e r e ope r a t i ona l

. F o r U n i t 2 ’ s

ba s e li ne e m i ss i on s f o r m ode li ng

, EPA u s ed t he m a x i m u m da il y N O x e m i ss i on s ( 27

, 636 l b / da y )

t ha t o cc u rr ed on 6 / 29 / 2009

. W e f ound t ha t h i ghe r da il y N O x e m i ss i on s ( 31

, 454 l b / da y )

o cc u rr ed on 6 / 14 / 2008.

U n i t 3 M od e l e d B a s e li n e E m i ss i ons

U n i t 3 w a s r e t r o f i tt ed wi t h L N B s i n m id 2009

. T he r e f o r e

, EPA u s ed a ba s e li ne pe r i od f r o m

5 / 14 / 2009

- 12 / 31 / 2010 , t o i n c l ude t he pe r i od w hen t he L N B s w e r e ope r a t i ona l

. F o r U n i t 3 ’ s

ba s e li ne e m i ss i on s f o r m ode li ng

, EPA u s ed t he m a x i m u m da il y N O x e m i ss i on s ( 23

, 156 l b / da y )

t ha t o cc u rr ed on 11 / 24 / 2010

. W e f ound t ha t h i ghe r da il y N O x e m i ss i on s ( 26

, 226 l b / da y )

o cc u rr ed on 7 / 2 / 2009.

U n i t 4 M od e l e d B a s e li n e E m i ss i ons

U n i t 4 w a s r e t r o f i tt ed wi t h L N B s i n ea r ly 2008

. T he r e f o r e

, EPA u s ed a ba s e li ne pe r i od f r o m

4 / 1 / 2008

- 12 / 31 / 2010 , t o i n c l ude t he pe r i od w hen t he L N B s w e r e ope r a t i ona l

. F o r U n i t 4 ’ s

ba s e li ne e m i ss i on s f o r m ode li ng

, EPA u s ed t he m a x i m u m da il y N O x e m i ss i on s ( 28

, 842 l b / da y )

t ha t o cc u rr ed on 11 / 28 / 2010

, w h i c h w e ag r ee wi th

.

U n i t 2 C o s t A n a l ys is

F o r t he c o s t ana l ys i s

, EPA u s ed a ba s e li ne e m i ss i on r a t e o f 0

. 295 l b / MM B t u w h i c h

, a cc o r d i ng

t o EPA

, i s ba s ed on t he 2011 a v e r age e m i ss i on r a t e o f U n i t 2

. H o w e v e r

, w e c a l c u l a t e t he

a v e r age annua l N O x e m i ss i on r a t e f r o m U n i t 2 t o be 0

. 2905 l b / MM B t u

. M a y be t he m e t hod o f

a v e r ag i ng i s d i ff e r en t and w e need t o unde r s t and i t.

U n i t 3 C o s t A n a l ys is

F o r t he c o s t ana l ys i s

, EPA u s ed a ba s e li ne e m i ss i on r a t e o f 0

. 254 l b / MM B t u w h i c h

, a cc o r d i ng

t o EPA

, i s ba s ed on t he 2011 a v e r age e m i ss i on r a t e o f U n i t 3

. H o w e v e r

, w e c a l c u l a t e t he

a v e r age annua l N O x e m i ss i on r a t e f r o m U n i t 3 t o be 0

. 2551 l b / MM B t u.

U n i t 4 C o s t A n a l ys is

F o r t he c o s t ana l ys i s

, EPA u s ed a ba s e li ne e m i ss i on r a t e o f 0

. 260 l b / MM B t u w h i c h

, a cc o r d i ng

t o EPA

, i s ba s ed on t he 2011 a v e r age e m i ss i on r a t e o f U n i t 4

. H o w e v e r

, w e c a l c u l a t e t he

a v e r age annua l N O x e m i ss i on r a t e f r o m U n i t 4 t o be 0

. 262 l b / MM B t u.

B ob