P. 1 5.2.1 1 Flatfishe s

Tabl e 5.2.11-4 . Estimate dnumbe r o f adult sandda b (Citharichthys spp. ) female s ( F H ) whos e reproductiv e output wa s equivalent

t o th e numbe

r o f larva e entraine d pe r yea r a t Diabl o Canyon Powe

r Plan t includin g th e standar

d erro r ofth e estimat

e (SE(FH)) an

d90 % confidenc e limit s (CL) . Analysi s Perio d 1 ) Oct 23 , 1996-Sep30 , 199

7 2 ) Oct . I,1997-Sep30 , 199 8 3 ) Jul 1 , 1997-Jun30 , 199 8 FH 42 6 9 2 39 3 SE(FH)

99 6 21 5 91 9 Uppe

r 90 % CL . 19,90 0 4,32 0 18,40 0 Lowe

r 90 % CL . 9 2 8

TENER A E9-055. 0 

# I 5-38 0 Fina l 316(b ) Demonstratio n Marc h 1,200 0P. 2 5.2.1 1 Flatfishe s Tabl e 5.2.11-5 . Sanddab s (Citharichthys spp.) : Sensitivit y analysi s fo

r FH fro mth e thre e analysi s period s recalculate dfo r eac h model inpu

t paramete r (0): E

Adj

_ T ± 1.64 5 SE(0); other parameter s ar

e ff. e ±--645cr0) wher

e CV(0) = 1.

0 or 100% . a ) Analysi s Perio d1 : Octobe r 1 , 1996-September

30 , 1997 Paramete r FH E-Adj-T S larvae ti Eggs/yr Longevit y Maturatio n Estimate

= 42 6 7,160,00 0 0.62 3 15,400 6 2. 5 Minimu

m 35 7 26 5 82. 3

' 15 7 31 4 Recalculate d FH

Maximu m 49 5 2,21 0 2,21 0 85 2 1,49 0 Rang e

13 7 1,94 0 2,13 0 69 5 1,18 0 b ) Analysi s Perio d2 : Octobe r 1,1997-Septembe r

30,199 8 Parameter FH F-Adj-T S larvae ti Eggs/yr Longevit y Maturatio n Estimate

= 9 2 1,540,000 0.62 3 15,400 6 2. 5 Minimu

m 64. 0 57. 1 17. 7 33. 8 67. 6 Recalculate dFH

Maximu m 11 9 47 5 47 5 18 3 32 1 Rang e

55. 4 41 8 45 7 15 0 25 3 c ) Analysi s Perio d3 : Jul y 1 , 1997-Jun e 30 , 199 8

Paramete r FH E ^Adj-T S larvae ti Eggs/y r Longevit y Maturatio n Estimate

= 39 3 6,610,00 0 0.62 3 15,400 6 2. 5 Minimu

m 324 24 5 75. 9 14 5 29 0 Recalculate dFH

Maximu m 46 2 2,04 0 2,04 0 78 7 1,38 0 Rang e

13 8 1,79 0 1,96 0 64 2 1,09 0

TENERA E9-055. 0 5-38 1 Fina l 316(b ) Demonstratio n Marc h 1.200 0P. 3 5.2.1 1 Flatfishe s Tabl e 5.2.11-6 . Estimatednumbe r o f equivalent

sandda b (Citharichthys spp. ) adult s ( AE L ) equa l t o th e numbe

r o f larva e entraine d pe

r yea r a t Diabl o Canyon Powe

r Plan t includin g th e standar

d erro r ofth e estimate (SE(AEL) ) an d 90 % confidenc e limit s (C.L.) . Analysi s Perio d Uppe r Lowe

r AEL SE(AEL) 90 % CL . 90 % CL . 1 ) Oc t 23 , 1996-Sep30 , 199

7 2 ) Octl,1997-Sep30 , 199 8 3 ) Jul I,1997-Jun30 , 199 8 2,37 0 6,71 0 51 1 1,45 0 2,19 0 6,200 249,00 0

54,00 0 18,40 0 2

3

Tabl e 5.2.11-7 . Sandda

b (Citharichthys spp.) : Sensitivit y analysi s fo

r AEL fro mth e thre e analysi s period s recalculate dfo r eac h mode l inpu t paramete r (0): E

Adj

_ T ± 1.64 5 SE(0) ; other parameter s ar

e Qe ±x

MSCy W wher e CV( 0) = 1.

0 or 100% . a ) Analysi s Perio d1 : Octobe r 1 , 1996-September30 , 199 7 Paramete r TEL 

## = E S early larvae S late larvae S early juvenile S juv. I S juv. II S juv. Ill S juv. IV S pre-recruit Estimat e

2,37 2 162,00 0 0.0024 1 0.56 3 0.56 7 0.86 1 0.85 9 0.86 7 0.85 1 0.78 8 Minimu m

1,99 0 45 8 45 8 45 8 45 8 45 8 45 8 45 8 45 8 Recalculate d AEL

Maximu m 2,75 0 12,30 0 4,21 0 4,18 0 2,75 0 2,76 0 2,73 0 2,79 0 3,01 0 Rang e

76 5 11,80 0 3,75 0 3,72 0 2,30 0 2,30 0 2,28 0 2,33 0 2,55 0

TENER A E9-055. 0 5-38 2 Fina l 316(b ) Demonstratio n Marc h 1,200 0P. 4 5.2.1 1 Flatfishe s Tabl e 5.2.11- 7 (continued) . Sandda b (Citharichthys spp.) : Sensitivit y analysi s fo

r AEL fro mth e thre e analysi s period s recalculate d fo r each model inpu

t parameter

(0): E

AdhT ± •1.64 5 SE(0); other

parameter s ar

e 0. e ±l <*W(6) wher

e CV(0) = 1.

0 or 100% . b ) Analysi s Perio d2 : Octobe r 1 , 1997-September

30 , 199 8 Parameter AEL = E-Adj-T S early larvae S late larvae S early juvenile S juv. I S juv. II S juv. Ill S juv. IV S pre-recruit Estimat e 51 1 1,540,00 0 0.0024 1 0.56 3 0.56 7 0.86 1 0.85 9 0.86 7 0.85 1 0.78 8 Minimu

m 35 6 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 Recalculate d AEL

Maximu m 66 5 2,65 0 90 6 90 0 59 3 59 4 58 9 60 0 64 8 Rang e

30 8 2,55 0 80 8 80 1 49 4 49 6 49 0 50 1 55 0

TENERA E9-055. 0 5-38 3 Fina l 316(b ) Demonstratio n Marc h 1,200 0P. 5 5.2.1 1 Flatfishe s Tabl e 5.2.11- 7 (continued) . Sandda b (Citharichthys spp.) : Sensitivit y analysi s fo

r AEL fro mthe thre e analysi s period s recalculated fo r eac h mode l inpu t paramete r (0): E

AdhT ± 1.64 5 SE(9); othe

r parameter s ar

e Q. e ±\(ASCV(6) w her e CV(0) = 1. 0 or 100% . c ) Analysi s Perio d3 : July , 1997-Jun e 30 , 199 8

Paramete r Estimat e AEl =2,19 0 F-Adj-T S early larvae S late larvae S early juvenile S juv. I S juv. II S juv. Ill S juv. IV S pre-recruit 6,610,00 0

0.0024 1 0.56 3 0.56 7 0.86 1 0.85 9 0.86 7 0.85 1 0.78 8 Minimu m

1,81 0 42 3 42 3 42 3 42 3 42 3 42 3 42 3 42 3 Recalculate d AEL

Maximu m 2,57 0 11,30 0 3,89 0 3,86 0 2,54 0 2,55 0 2,52 0 2,57 0 2,58 0 Rang e

76 8 10,90 0 3,46 0 3,44 0 2,12 0 2,13 0 2,10 0 2,15 0 2,36 0

TENER A E9-055. 0 5-38 4 Fina l 316(b ) Demonstratio n Marc h 1,200 0P. 6 5.2.1 1 Flatfishe s Tabl e 5.2.11-8 . Sandda

b (Citharichthys spp.): Monthl y estimate s o f

proportiona

l entrainment ( PE, ) an d annua l proportio n o f

larvae hatche d i

n th e rt h survey perio d (£) an

d associate d standar d error s (SE) used i

n estimatin g entrainment

mortalit y fo r tw o analysi s periods . a ) Analysi s Perio d 3 : Jul y 1 , 1997-Jun e 30 , 199 8 Survey Star

t Dat e Ju l 21 , 1997 Au g 25 , 1997 Se p 29,199 7 Oc t 20 , 199 7 No v 17 , 1997 De c 10 , 1997 Ja n 22 , 199 8 Fe b 26 , 199 8 Ma r 18 , 199 8 Apr 15 , 199 8 Ma y 18 , 199 8 Jun 8 , 199 8 PE,

0.0029 1 0.0010 1 0 0 0 0 0 0 0 0.85 9 0 0 SE(PE,)

0.00075 0 0.0010 7 0 0 0 0 0 0 0 0.91 1 0 0 /

0.64 5 0.19 2 0.023 5 0.0052 8 0.00097 0 0.024 6 0.096 6 0.0025 9 0 0.0089 3 0 0 

### SE(f,)

0.017 2 0.012 7 0.0045 2 0.0020 0 0.00097 0 0.0051 6 0.0096 6 0.0011 6 0 0.0026 9 0 0 b ) Analysi s Perio d 4 : Jul y 1 , 1998-Jun e 30 , 199 9 Survey Star

t Dat e Ju l 21 , 199 8 Au g 26 , 199 8 Se p 16 , 199 8 Oc t 6 , 199 8 No v 11 , 199 8 De c 9 , 199 8 Ja n 12 , 199 9 Feb 3,199 9 Ma r 17 , 199 9 Apr 14 , 199 9 Ma y 24 , 199 9 Ju n 23 , 199 9 PE,

0.0011 5 0.00074 0 0.00054 0 0.0027 1 0 0 0 0 0 0 0.0085 5 0.043 0 ££(/>£, )

0.00084 0 0.00075 0 0.00055 0 0.0027 9 0 0 0 0 0 0 0.0050 2 0.041 6 

## f

0.12 6 0.046 7 0.045 3 0.12 8 0 0 0 0 0 0 0.32 8 0.327 

### SE(f,)

0.018 9 0.011 2 0.010 3 0.016 7 0 0 0 0 0 0 0.027 7 0.038 7

TENER A E9-055. 0 5-38 5 Fina l 316(b ) Demonstratio n Marc h 1,200 0P. 7 5.2.1 1 Flatfishe s Tabl e 5.2.11-9 . Averag e spaw n pe r female Californi ahalibu

t (Paralichthys califomicus). Spawning frequency i s averag e day s betwee n spawning event s fo

r eac h year . Dat

afro m Caddell etal . (1990) . Averag e number Numbe r o f egg s Spawnin g frequenc y Years No . spawn s egg s pe r spawn spawne d pe r yea r (d ) 1985-86 ' 1 2 455,00 0 5,460,000 To 1986-8 7 5 313,00 0 1,565,00 0 7. 2 1987-8 8 1 3 589,00 0 7,657,000 14. 0

Tabl e 5.2.11-10 . Mortalit

y rate s forjuvenil e Californi ahalibut (Paralichthys califomicus) fo

r th e 198 8 year-clas s u

p t o 11 5 d . Dat

afro mKrame r (1990 ) Lengt h clas s (mm ) <=1 0 11-1 5 16-2 0 21-2 5 26-3 0 31-3 5 35^1 0 41^1 5 46-5 0 51-5 5 56-6 0 61-6 5 66-7 0 Ag e clas s (d )

30. 3 43. 3 53. 3 61. 8 69. 3 76. 2 82. 5 88. 4 94. 1 99. 5 104. 8 109. 9 114. 9 (z(tj) )

0.04 4 0.01 6 0.01 5 0.01 3 0.01 3 0.01 3 0.01 1 0.01 4 0.01 2 0.01 1 0.01 3 0.01 2

TENER A E9-055. 0 5-38 6 Fina l 316(b ) Demonstratio n Marc h 1,200 0P. 8 5.2.1 1 Flatfishe s

Tabl e 5.2.11-11 . Estimate d tota l annua l entrainmen t(E T ) an d standar d erro r ( SE(E T

)) fo r Californi a halibu t(Paralichthys califomicus) larva e from th e thre e analysi s periods . Analysi s Perio d E T SE(E T ) 1 ) Oc t23 , 1996-Sep30 , 199 7 2 ) Octl , 1997-Sep30 , 199 8 3 ) Ju l I,1997-Jun30 , 199 8 2,270,00 0 14,300,00 0 14,100,00 0 296,00 0

2,130,00 0 2,130,00 0

Tabl e 5.2.11-12 . Estimate d tota l annua l adjuste d entrainmen t(E Adj

_ T) an d standar d erro r (SE(E Mj

_ T ) ) fo r Califomi a halibu t(Paralichthys califomicus) larva e estimate d fo r th e thre e analysi s periods . Analysi s Perio d E Adi

_ T SE(E AdJ . T ) 1 ) Oc t23 , 1996-Sep30 , 199 7 8,260,00 0 1,080,00 0 2 ) Oc t1 , 1997-Sep30 , 199

8 15,700,00 0 2,340,00 0 3 ) Ju l 1 , 1997-Jun30 , 199 8 15,500,00 0 2,330,00 0

TENERA E9-055. 0 5-38 7 Fina l 316(b ) Demonstratio n Marc h 1.200 0P. 9 5.2.1 1 Flatfishe s Tabl e 5.2.11-13 . Californi ahalibut (Paralichthys califomicus): Monthl y estimate s o f proportiona

l entrainment

(PE, ) an d annua l proportio n o f

larva e hatche d i

n th e rth survey perio d(f) an

dassociate dstandar

d error s (SE) use

d i n estimatin g entrainmen

t mortalit y fo r tw o analysi s periods . a ) Analysi s Perio d3 : Jul y 1 , 1997-Jun e 30 , 199 8 Surve y Star t Dat e PE SE[PE,) 

## f

b ) Analysi s Perio d4 : Jul y 1 , 1998-Jun e 30 , 199 9 Surve y Star t Dat e PE, SE(PE,) 

## f SE(f) Ju l 21 , 199 7 Au g 25 , 199 7 Se p 29 , 199 7 Oc t 20 , 199 7 No v 17 , 199 7 De c 10 , 199 7 Ja n 22,199 8 Fe b 26 , 199 8 Ma r 18 , 199 8 Ap r 15 , 199 8 Ma y18 , 199 8 Ju n 8 , 199 8 0.00070 0

0 0 0 0 0 0.012 7 0 0 0.0014 3 0 0 0.00053 0

0 0 0 0 0 0.015 5 0 0 0.00065 0 0 0 0.018 6

0.042 1 0.0028 3 0 0 0.0042 5 0.011 5 0 0.00085 0 0.76 1 0.15 6 0.0027 3 0.0028 4

0.0058 2 0.0010 7 0 0 0.0012 7 0.0024 0 0 0.00060 0 0.014 6 0.010 9 0.0010 4 SE(f,) Ju l 21 , 199 8 Au g 26 , 199 8 Se p 16 , 199 8 Oc t 6 , 199 8 No v 11 , 199 8 De c 9 , 199 8 Ja n 12 , 199 9 Fe b 3,199 9 Ma r 17 , 199 9 Ap r 14 , 199 9 Ma y24 , 199 9 Ju n 23 , 199 9 0.0013 6

0 0 0 0 0 0 0 0.075 1 0.85 9 0 0 0.00069 0

0 0 0 0 0 0 0 0.037 2 0.91 1 0 0 0.091 0

0.024 9 0 0 0 0 0 0 0.86 1 0.022 7 0 0 0.0098 4

0.0037 6 0 0 0 0 0 0 0.011 2 0.0039 2 0 0

TENER A E9-055. 0 5-38 8 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.1 0 5.2.1 1 Flatfishe s

0.040 - 0.038 - 0.03 6 - ^ 0.03 4 - yj 0.03 2 - y j 0.03 0 ~ , _0.02 8 - + 0.02 6 ~ " 0.02 4 - • 5 0.02 2 7 S - 0.02 0 ~ .& • 0.01 8 7 W 0.01 6 ~ C D 0.01 4 — Q 0.012 - { = 0.010 7 0) 0.00 8 7 2 0.006 - 0.004 - 0.002 7 0.000 -

T designatessurv e 

### s iut,i,i,l l |O|N|O1 J I ,09 6 I ywithdensity= 0 I



### I 

# II I „ Sl 

## J» m 

## „J n 

## lJ»lll l Sanddab s (Citharichthys spp. )



# J Wnn'rl ' i n 1 n? m nimmi t 1 1 1 S 1 . . . |F|M|A|M|J|J|A|S|O|N|D| J |F|M|A|M|J|J|A|S[O|N|D[J| F

1SS 7 | 189 8 |

Surve y Dat e 

# ..l l

|M|A|M]J | los e |

Figur e 5.2.11-1 . Weekl y mea n larva l densit y (#/m 3 + 1 S.E. ) a t th e DCP P intake .

TENERA E9-055. 0 5-38 9 Fina l 316(b ) Demonstratio n Marc h 1,200 0m

z m m C D • o c n c n

w C O o

3 !___ _ w

_._ & _cr 2 °

- * «

- *- * ts ) C D O S. o o O 3 Sanddab s (Citharichtys spp. )

C D 

# E 0.1 6 0.14 0.1 2 0.1 0 0.0 8 0.0 6 0.04 0.02 0.0 0

Dept h Contour

s

— —2 0 meter s «•— • 4 0 meter s ^

—6 0 meter s Poin t Bucho n

DCP P Intak

e

Poin t San Lui s

Jul . 21/9 7 Aug . 25 , "9 7 Sep . 29,'9 7 Oct . 20,'9 7 Nov . 17 , *9 7 Dec . 10 , "9 7 Figur e 5.2. 1 l-2a . Mean larva l density (#/m 3 ) collecte d in th e DCP P study gri d cell s an d a t th e entrainmen t

samplin g location . 0 ) 3 ( A rT (0. il.P.1 2 5.2.1 1 Flatfishe s

Q . Q . W 

# s .C O C O O c n

. O ro T J X J c ro CO ^ ^? § § § § 8



## ,W/ # 

# I • E c 5 £Dep at & "5 E 8 • 

# 1 C O & 1 5 E § • 

# 1 C O s 1 5 E 

### s 1 

# 1 c

o o

_ o O O c

c 0 > c u

U C J • o • c o o 

## £ c u C U 

## u Q c u T 3 (__> rrr o j u " o u

. E

C/ 5 c u • o
c e a r) •a e © «__ > > » • X l I N i « N C U lm s OX ) TENERA E9-055. 0 5-39 1 Fina l 316(b ) Demonstratio n Marc h 1.200 0m

z m m i n b

V 1 C O r o

3 S L w

— 7 a> 

# a i

• * 2 1 t o 3 O s : o o O 3 Sanddab s (Citharichtys spp. )

C O 

# E 0.1 6 0.1 4 0.1 2 0.1 0 0.0 8 0.0 6 0.0 4 0.0 2 0.0 0

Dept h Contours

— —2 0 meter s • —4 0 meter s >^— • 6 0 meter s Poin t Bucho n

DCP P Intake

Poin t Sa n Lui s

Jul . 20 , '9 8 Aug . 25 . '9 8 Sep . 15 , '9 8 Oct . 5 , '9 8 No v10 . '9 8 Dec . 8 , '9 8 Figur e 5.2. 1 l-2 c (continued) . Mea n larva l density (fl/m 1 ) collecte d i n th e DCP P study gri d cell s an d a t th e entrainmen t

samplin g location . c n k >

Vt 3 - » Cf l

'" «m

z m m C O • o c n o i b

V C O C O C O

3 0 ) C O __f c 2 D 

### ir § r * Si t o S O £ : o o O 3 Sanddab s (Citharichtys spp. )

C O 

# E 0.1 6 0.1 4 0.1 2 0.1 0 0.0 8 0.0 6 00 4 0.0 2 0.0 0

Dept h Contour s

— —2 0 meter s

— —4 0 meter s —• —6 0 meter s Point Bucho n

DCP P Intak

e

Poin t San Lui s

Jan . 11.'9 9 Feb . 2.'9 9 Mar . 16. ' Apr . 13.'9 9 Ma

y 23,'9 9 Ju n 22.'9 9 Figur e 5.2.U-2 d (continued) . Mean larva l density (#/m 3 ) collecte d i n th e DCP P stud y gri d cell s an d at th e entrainmen t

samplin g location . c n

0 ) 

### 3 Cf l 3 " C D - vt

•p5.2.1 1 Flatfishe s P.1 5

Sanddab s (Citharichthys spp. ) N=12 6 1 5 —Occurrence0III I III

OFrequencyIIIIIIPercentIIIIII M i r 

# J Media n

1 %



# u b 1 Mea n 9 9 %


# ill ,1 I ' ' ' ' I ' ' • I ' ' • ' I ' 1. 2 1. 7 2. 2 2. 7 3. 2 3. 7 4. 2

c Length Categor y (mm )

i • i i i • i i • i

_ > 2 4 6 8 I O 1 2 1 4

Estimate d ag e (days ) 

# 1 Ivla x

4. 7 *»W , 1 ' II I 1 6 •*•«* . Figure 5.2.11-3 . Lengt

h frequency of

all measure d larva

l fish collecte d i

n th e entrainment samples . Minimum , median , mean , maximum , an d centra l 98 % ofth e larva

l length s ar

e noted . X-axi s scal e i s not

continuou s a

t large r lengths .

TENER A E9-055. 0 5-39 4 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.1 6 5.2.1 1 Flatfishe s

5 5 ~ 5 0 ~ 4 5 ~ 4 0 - 3 5 - 3 0 — 0 ) 25 ~ o c 20 - 0 ^ 1 5 — h » U . 3 10 - o r . 5 — o _ 

## o _ 0 • — o > . c - < U 50 - 3 O " 45 ~ 0) - « - 4 0 — u . 3 5 — *-* " ~ C 3 0 — 'C D ~ O 2 5 — w ~ d) 20 ~ C L 1 5 — 1 0 — 5 — — 0 Sanddab s (Citharichthys spp. ) Entrainment : N= 4 Mediaj J % Mi r Mea n 99 % Max

1. 0 6. 0 11. 0 16. 0 21. 0 26. 0 31. 0 36. 0 41. 0 46. 0 Grid : N=5 2 Med i u 1 Mi n

1 

# 1 1 | i

" o Mea n 99 % Max



### • I I •• • 

### • • • , T , { , , , , | , , . , r , , , r , . , | , , , , | ,,,•!,,, , , , , , . , , , 1. 0 6. 0 11. 0 16. 0 21. 0 26. 0 31. 0 36. 0 41. 0 46. 0

Lengt h Categor y (mm )

Figur e 5.2.11-4 . Lengt

h frequency o f

measure d fish fro

mentrainment

survey s tha

t paire d wit

h gri dsurvey s (bot

h year s combined) . Minimum , median , mean , maximum , an d centra l 98 % ofth e larva l length s ar

e noted . X-axi s scal e i s not

continuou s a

t large r lengths . TENER A E9-055. 0 5-39 5 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.1 7 5.2.1 1 Flatfishe s

a i to+/-MeanDensity(#/m3 0.02 4 —oobbN10O10lllllllll

0.018- r 0.01 6 — 0.01 4 -z. 0.01 2 ~z 0.010- E 0.00 8 - § O.0O 6 - = 0.00 4 ~ i O.O0 2 - = 0.00 0 - r -0.00 2 - E

. -0.00 4 — Sandda b (Citharichthys spp. )

i

• L 

# [ I • •

•

IIIIIIII I 199 0 199 1 199 2 199 3 199 4 199 5 199 6 1997 199 8 Yea r

Figure 5.2.11-5 . Annua

l mea n densit y +/

- 2 standar d error s (vertica

l lines ) an d grand mea

n densit y fo r al l year s combined(horizonta l line ) fo r th e Intak e Cove surfac e plankto n tows . Th e annua l mea n densitie s ar

e base do n seve n consecutiv e month s o f

dat a(Decembe

r throug h June ) excep t fo r 1990 , which ha

donly five month s (Februar y through June) .

TENER A E9-055. 0 5-39 6 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.1 8 5.2.1 1 Flatfishe s

0.40 - o.3e - 0.3 2 - 0.2S - 0.24 - £ 0.2 0 - o.i e - 0.12 - O.OS - 0.0 4 — "

* P s along i



### I

-i—i—|—l— r Sanddab s (Citharichthys spp. ) - mea n duratio n Analysi s Perio

d 3 : Ju l 1997-Ju n 1998 ihor a

i i i i Densit y

Extrapolate d P e 90 % Cl .

^Pu- 0.014 5 -^""^ ^ ^ ^

Pu = 0.0049 3 ±0.043 2 ^^-^^

i—i—i—r-i—i—i—i—r-i—i—i—i—r — 1—i—r—i—|—i—r—i—i—|— r —i—i—i—r 1 O x O k m e x

e r k m l O x

1 7 4 k m I S x

2 6 1 k m 2 O x

3 4 7 k m 2 6 x

4 3 4 k m SO x

S 2 1 k m 3 S x

OO S k m 4 0 x

ee s k m Siz e o r Populatio n Rotativ e t o Stud y Orl d Equivalen t Dlstano a Alongthor a Sanddab s (Citharichthys spp. ) - mea n duratio n Analysi s Perio d 4 : Ju l 1998-Ju n 199 9

Estimat e 90 % Cl . Pu = 0.066 3 Pu- 0.045 9 ±0.12 0

O x O k m S x

8 7 k m 1 0 x

1 7 4 k m 1 S x

2 6 1 k m 2 0 x

3 4 7 k m SO x S 2 1 k m 3 B x

OO S k m 4 0 x

e e s k m Siz e o f Populatio n Relativ e t o Stud y Orl d Equivalen t Distanc e Alongshor e Figur e 5.2.11-6a . Tota

l annua l entrainmentmortalit

y ( ^ ) an

d 90 % confidenc e interva l (C.I. ) a s a functio n ofth e reciprocal ofth e fraction ofth e populatio n a tris k an d containe d i n th e stud y gri d (/£ ) use d t o approximate th e alongshor e exten tofth e stud y gri d populatio n expande d o n th e basi s o f

alongshor e curren

tmovement s an

d di e offshor e extrapolatio n o f study gri d abundanc e extende d alongshor e usin g bot h onshor e an

d alongshor e curren

tmovement s with 90 % CI.' s indicated . TENER A E9-055. 0 5-39 7 Fina l 316(b ) Demonstratio n Marc h 1.200 05.2.1 1 Flatfishe s P.1 9

Sanddab s (Citharichthys spp. ) - maximu m duratio n o.e o O.B 4 0.48 - 0.42 - 0.3 S — £ 0.3 0 —

J 0.24 - 0.1 8 — 0.12 - 0.06 - o.oo Analysi s Perio d 3 : Ju l 1997-Ju n 199 8

P s alongshor e Estimat e 90 % Cl .

-P* f = 0.015 7 Densit y Extrapolate d P s

'Pu = 0.0041 3 ±0.042 1

2 8 x SO x SS x 40 x 4 3 4 k m 62 1 k m OO S k m 69 5 k m Siz e o f Populatio n Relativ e t o Stud y Orl d Equivalen t Distanc e Alongshor a Sanddab s (Citharichthys spp. ) - maximu m duratio n o.oo O.S 4 ' 0.4 8 ' 0.42 - 0.36 ' 0.30 - 0.24 - 0.1 8 ' 0.1 2 " o.oo I

t I I \ \ \ \ \ \ \

!—i—i—r - R » alonoshor e

j /fti = 0.053 7

> * : y 

# ^_L_ _ Analysi s Perio d 4 : Ju l 1998-Ju n 199 9

Densit y Extiapolate d P i 90 % Cl .

/Pu - 0.010 6 ±0.094 3 y -i —i—i—i—i—i—;—r- i—i—i—i—i—i—i—i—i—i— i —i—'— r O x O k m S x

S 7 k m l O x

1 7 4 k m 1 S x

2 S 1 k m 2 0 x

3 4 7 k m 2 S x

4 3 4 k m SO x

S 2 1 k m SS x

OO S k m 4 0 x

OS S k m Siz e o f Populatio n Relativ e t o Stud y Orl d Equivalen t Distanc e Alongshor a Figur e 5.2.11-6b . Tota

l annua l entrainmen

tmortalit y (P^) an

d 90 % confidenc e interva l (CI. ) a s a functio n ofth e reciprocal ofth e fraction ofth e populatio n a tris k an d containe d i n th e study gri d (p" s ) use d t o approximat

e th e alongshor e exten tofth e stud y gri d populatio n expande d o n th e basi s o f alongshor e curren

tmovements an

d th e offshor e extrapolatio n o f study gri d abundance extende d alongshor e usin g bot h onshore an

d alongshor e curren

tmovements with 90 % C.I.' s indicated . TENER A E9-055. 0 5-39 8 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.2 0 5.2.1 1 Flatfishe s

Morr o Ba

y Area Landing s of Sanddab s (Citharichthys spp.) . vSource : PSMFC Database . 4 5 - 4 0 - 3 5 - 3 0 - I 20 - n u 1 5 - 1 0 - 

# • •

199 3 199 4 199 5 199 6 199 7 199 8 199 9 Yea r Figure 5.2.11-7 . Commercia l landing s o f

sandda b specie s (Citharichthys spp. ) i n th e Monr

o Ba y are abetween 199 3 an

d199 9 (Source : PSMF

C Database) .

TENERA E9-055. 0 5-39 9 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.2 1
5.2.1 1 Flatfishe s

Ii i tn + E

C O c C D 

### aMean 0.15 " 0.14 - 0.13 - 0.12 - 0.1 1 - 0.10 - 0.09 - 0.08 - 0.07 - 0.06 - 0.05 - 0.O4 - 0.03 - 0.02 - 0.0 1 - o.oo -

• designatessurve . Californi a halibu t

(Paralichthys

califomicus)

n"mm?i*fT" m ?~»SiVfm'! V »*»?*mnffn»n''t' » i mil* ! inr* m ? m i i i i i • I |O|N|D| J |F|M|A|M|J|J|A|S|O|N|D| J |F|M|A[M|J|J|A|S|O|N|D[J|F|M|A| M | loe e | iss 7 | ise a | Surve y Dat e .wit h density * 0 SS 9 1

1 

# n i

Figur e 5.2.11-8 . Weekl

y mea n larva l densit y (#/m3 + 1 S.E. ) a

t th e DCP P intake .

TENER A E9-055. 0 540 0 Fina l 316(b ) Demonstratio n Marc h 1,200 0m

z m m C O • o O l c n o

2 D

O =r . O O O 3 Californi a halibu t (Paralichthys califomicus)

C O 

# E 0.09 6 0.08 0 0.06 4 0.04 8 0.03 2 0.01 6 0.00 0 Poin t Bucho n

DCP P Intak

eFinal3 g> Dept h Contour s 2 0 meter s

— — • 4 0 meter

s
—••• —6 0 meter

s Poin t San Lui s

Jul . 21 . "9 7 Aug . 25,'9 7 Sep . 29.'9 7 Oct . 20.'9 7 Nov . 17,'9 7 Dec . 10 . "9 7 

### Figur e 5.2. 1 l-9a . Mea

n larva l densit y (ft/m1 

### ) collected i

n the DCP P stud y grid cell s an

d a t th e entrainmen

t sampling location . U l 

### 3 vt 3 " C O c a

r

om

z m 

## £ m C O • o c n c n b

o t o

3 0 ) C O CT ) 2 a » g > 

# § 1

- * c n r o o > o =• . o o o 3 Californi a halibu t (Paralichthys califomicus)

C O 

# E 

# 3 E 0.09 6 0.08 0 0.06 4 0.04 8 0.03 2 0.01 6 0.00 0

Dept h Contour s

• 2 0 meter s

— • » 4 0 meter s

••• " 6 0 meter s Poin t Bucho n

DCPP Intak

e

Poin t San Lui s

Jan . 22.'9 8 Feb . 26.'9 8 Mar . 18.'9 8 Apr . 15,'9 8 Ma y 18.'9 8 Jun . 8.'9 8 Figur e 5.2. 1 l-9 b (continued) . Mean larva l densit y (#/m 3 ) collecte d in th e DCP P study gri d cell s an d at th e entrainmen t

samplin g location . U l

T l D i 

### 3 Vt 3 - C D Vt

r

om

z m m C D i o c n c n

3 C O I T 2 O

3

- k C O

. «^ . t o 3 O SS : O O O 35-403 c

o 

# E % 0.09 6 0.08 0 0.06 4 0.04 8 0.03 2 0.01 6 0.00 0

Dept h Contour

s

— —2 0 meter

s

— ^ 4 0 meter

s • —6 0 meter

s Californi a halibu t (Paralichthys califomicus)

Poin t Bucho n

DCP P Intak

e

Poin t Sa n Lui s

Jul . 20 , '9 8 Aug . 25 , '9 8 Sep . 15 , '9 8 Oct . 5 . '9 8 No v10 , '9 8 Dec . 8 , '9 8 

### 2 1 Figur e 5.2. 1 l-9 c (continued) . Mea n larva l densit y (#/m 3 

### ) collectedi

n the DCP P stud y grid cell s an

d a t th e entrainmen

t sampling location . o r k >

a t -X C O 3 \ C D ( A

r

om

z m m 

## S e n c n

3 92 . c o at C T ? * _ m 0 ) C D

- k C O t o 3 o =r . o o o 3 Californi a halibu t (Paralichthys califomicus)

15-404 C O 

# E * 0.09 6 0.08 0 0.06 4 0.04 8 0.03 2 0.01 6 0.00 0

Dept h Contour s

— —2 0 meter s

• — » 4 0 meter s ^ —6 0 meter s Poin t Bucho n

DCPP Intak

e

Poin t Sa n Lui s

Jan . 11 . '9 9 Feb . 2 , '9 9 Mar . 16 , '9 9 Apr . 13 . '9 9 Ma y 23 . '9 9 Ju n 22 , '9 9 Figur e 5.2. 1 l-9 d (continued) . Mean larva l density (#/m 3 ) collecte d in th e DCP P study gri d cell s an d a t th e entrainmen t

samplin g location . U l r o

u 

### 3 C O 3 " < D (f l

ro

U lP.2 6 5.2.1 1 Flatfishe s

Califomi a halibu t (Paralichthys califomicus) N=26 7

C U u c C D k _ l_ _ 3 o o O «« — o > » u c d ) 3 c r a > w . L L rf<^ c a > u t_ _ a > 

### a . 2 5 —

2 0 — — — ~

_ _

_ _ — i s —

_ — — — — — — i o —

mm. ~

~ ~ —tl11111IIll1 M i n

1 IIII,wwl w ,— M m 

# •JlllJ l 1 . 4 2. 4 3. 4 4. 4 S. 4 6. 4 7. 4 8. 4 9. 4

Lengt h Categor

y (mm )
i—•—•—i—•—•—i—•—•—i—•—•—i—•—•—i—•—'—i—•—•—i—•—•—i—•—•— i O 3 6 S 1 2 1 5 I B 2 1 2 4 2 7

Estimate d age (days

) Figure 5.2.11-9 . Lengt

h frequency o f

al l measure d larva

l fish collecte d i

n the entrainment samples . Minimum , median , mean , maximum , an d centra l 98 % ofth e larva

l length s ar

e noted . X-axi s scal e i s no t

continuou s a

t large r lengths .

TENERA E9-055. 0 5-40 5 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.2 7 5.2.1 1 Flatfishe s
Californi a halibu t (Paralichthys califomicus)

Entrainment : N= 9 35 " 30 " 25 " 20 "

° 15- 1 U c • 10- J

o u O Medii

M i ljan | Mea n % 99 % Ma x

> . ° 35 " c C D 3 30 _ C T C P .Y 25 " I

C C D U i__ . C D 0 . 2 0 — 15 " Mi n 1 % Media n Grid : N=11 5 Mea n I' ' ' ' I ' ' ' ' I ' ' ' ' I ' ' ' ' I ' ' ^ ' I ' ' ' ' I ' ' ' ' 1. 6 2. 6 3. 6 4. 6 5. 6 6. 6 7. 6



# ; 

# , •••llllllll l •••-••III . 99 %



## Jf E Ma

x

I' ' ' ' I ' ' ' ' I ' ' ' • I ' ' ' ' I ' ' ' ' I 1 . 6 2. 6 3. 6 4. 6 5. 6 6. 6 7. 6

Lengt h Categor

y (mm )

Figur e 5.2.11-11 . Lengt

h frequency o f

measured fish fro

m entrainmen

tsurvey s tha

tpaired wit

h grid survey s (bot

h year s combined) . Minimum , median , mean , maximum , an d centra l 98 % ofth e larva l length s ar

e noted . X-axi s scal e i s notcontinuou s a tlarger lengths . TENER A E9-065. 0 5-40 6 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.2 8 5.2.1 1 Flatfishe s

• u J C O E 5§ ,MeanDensity 0.02 4 —

0.02 2 ---• O.O2 0 - r 0.01B~ ^ 0.016 ~ O.014— f 0.01 2 -z 0.010- ^ O.OO S -j. o.ooe - = 0.00 4 -z O.O0 2 ~z O.OO O - : -0.00 2 - = -0.00 4 — Californi a halibu t (Paralichthys califomicus)



## . I 

## i , * i

IIIIII I 199 0 199 1 199 2 199 3 199 4 199 5 199 6 Yea r < 

### I

i 199 7 • I 

### I

I 199 8

Figur e 5.2.11-12 . Annua

l mea n densit y +/

- 2 standar

d error s (vertica

l lines ) an d gran d mea

n densit y fo r all year s combine d(horizonta l line ) fo r th e Intak e Cove surfac e plankto n tows . The annua l mea n densitie s ar

e basedo n seve n consecutiv e month s o f

data(Decembe

r throug h June ) excep t fo r 1990 , which ha

donly five month s (Februar y throug h June) .

TENER A E9-O55. 0 5-40 7 Fina l 316(b ) Demonstratio n Marc h 1,200 05.2.1 1 Flatfishe s P.2 9

i . o — O.C9 - 0.8 - 0.7 - o. e - o f o.s o.4 - 0.3 - 0.2 - 0 . 1 - 0.0 - Californi a halibu t (Paralichthys califomicus)

- mea n duratio n Analysi s Perio d 3 : Ju l 1997-Ju n 199 8 R a alongsho m

-ZA r ^ i 1 •i—i— i —;—r—i — Densit y

Extrapolate d R a Estimat e 90 % Cl .

^Pu - 0.0026 9

- ^ ^^- —Pu

= 0.00083 5 ±0.032 3 ^ —1—i—i—i—i—|—i—i—r—i—i—i—i—i—i—|—i—i—i—i—i—i—i—i—i— | i i—i—i—r 1 O x 6 x lO x 15 X 20 x 2fi x SO x SO x 4b x O k m 8 7 k m 17 4 k m 281k m 347K m 43 4 k m 621k m 0O 8 k m OO S K m Siz e o f Populatio n Relativ e t o Stud y Orl d Equivalen t Distanc e Alongshor e Californi a halibu t (Paralichthys califomicus)

- mea n duratio n

R a alonoalior a Analysi s Perio d 4 : Ju l 1998-Ju n 199 9 Estimat e 90 % Cl .

Pu-- 0.17 5 P * =0.12 3 ±0.18 4

III I

20 x 34 7 k m 2S x

4 3 4 k m SO x

62 1 k m SO x 40 x

eo e k m ee s k m Siz e o f Populatio n Relativ e t o Stua y Orl d Equivalen t Distanc e Alongshor e Figur e 5.2.11-13a . Tota l annua l entrainmen

tmortalit y (P u ) an d 90 % confidenc e interva l (CI. ) a s a functio n ofth e reciprocal ofth e fraction ofth e populatio n a tris k an d containe d i n th e stud y gri d (/ £ ) use d t o approximat e th e alongshor e exten tofth e study gri d populatio n expande d o n th e basi s o f

alongshor e curren

tmovements an

d th e offshore extrapolatio n o f study gri d abundance extende d alongshor e usin g bot h onshor e an

d alongshor e curren

tmovements with 90 % CI.' s indicated . TENERA E9-055. 0 5-40 8 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.3 0 5.2.1 1 Flatfishe s

1.4 0 — 1.26 -

o.e e —

—__ . 0.8 4 £ 0.7 0 ~ 0.8 8 — 0.42~ 1 0.2 8 - i 0.14 H o.oo H Californi a halibu t (Paralichthys califomicus)

- maximu m duratio n Analysi s Perio d 3 : Ju l 1997-Ju n 199 8 R a alonQShor e

^

— i i i i I— i Estimat e 90 % Cl . j Densit y • Extrapolata d R a • y Pu = 0.0044 9 y Pu - 0.00076 3 ±0.032J

—i—i—i—i—i—i—i—i—|—i—i—i—i—]—i—i—i—i—|—r — T — r ' i 'y " T IIII — i — r •T-'T-T 1 O x O k m O x

8 7 k m lO x

17 4 k m 1O x 20 x

2 8 1 krr t 34 7 k m 2S x 4 3 4 k m SO x

5 2 1 k m SO x

eo e k m 4 0 x

ee e k m Siz e o f Populatio n Relativ e t o Stud y Gri d Equivalen t Dlstano * Alongshor e Californi a halibu t (Paralichthys califomicus)

- maximu m duratio n Analysi s Perio d 4 : Ju l 1998-Ju n 199 9 Estimat e 90 % Cl .

Pu-- 0.052 5 ±0.11 8

» o f Populatio n Relativ e t o Stud y Ori d Equivalen t Dlstano * Alongshor e Figur e 5.2.11-13b . Tota l annua l entrainmentmortalit

y (P^) an

d 90 % confidenc e interva l (CI. ) a s a functio n ofth e reciprocal ofth e fraction ofth e populatio n a tris k an d containe d i n th e stud y gri d (p" s ) use d t o approximat

e th e alongshor e exten tofth e study gri d populatio n expande d o n th e basi s o f alongshor e curren

tmovement s an

d th e offshor e extrapolatio n o f study gri d abundanc e extende d alongshor e usin g bot h onshor e an

d alongshor e curren

tmovement s wit h 90 % C.I.' s indicated . TENER A E9-055. 0 5-40 9 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.3 1 5.2.1 1 Flatfishe s

Morro Ba y Area Landing s o

f Californi a Halibu t (Paralichthys califomicus). Source : PSMF C Databas e 6 0

Figure 5.2.11-14 . Commercia l landing s o f

Californi ahalibut

(Paralichthys califomicus) i n th e Morr o Ba y are abetwee

n 199 3 an d 199 9 (Source : PSMF

C Database) .

TENER A E9-055. 0 5-41 0 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.3 2



# Blan k Pag eP.3 3 6. 0 Alternativ

e Intak e Technologie s 

## 6. 0 EVALUATIO N O F ALTERNATIV E INTAK E

TECHNOLOGIE S A numbe r o f coolin g wate

r technologie s ar

e explore d whic

h ar e currently i

n us e elsewher

e o r propose dfo

r us e i n powe r plan t coolin g wate

r system s to minimiz e th e los s o f aquati c organism s du e t o entrainment

an dimpingement . Sectio n 316(b ) ofth e Clea n Wate r Ac t (CWA ) state s tha

t "coolin g wate

r intak e structures " ar

e to "reflect

th e bes t technolog y availabl e fo

r minimizin g advers e environmenta

l impacts. " A s discusse d i

n th e Introductio n (Sectio n 2 ) o f thi s report , USEP A ha s indicate dtha

t assessmen

t o f advers e environmenta

l impact s (AEI ) shoul d b e based A_^ > o n a n evaluatio n o f

population-leve l effects . Thi s repor t show s tha t Diabl o Canyon Powe

r Plan t (DCPP) ha s not

cause dpopulation-level effects an d therefore , w e concluded tha t DCP P ha s not cause dAEI . However , w e provide thi s sectio n o n alternativ e technologie s i n respons e to a requiremen

t b y th e RWQCB . Thi s sectio n ofth e repor t include s adescriptio n o f

potentia l modification s t o th e presen t intak e structur e a t DCPP . Additionally , fo

r informationa

l purposes , thi s sectio n present s discussio n o f possibl e operationa

l an d technologica

l alternative s t o th e current coolin g wate

r syste mtha t ar e not par t ofth e intak

e structur e although consideratio n o f • thes e alternative s i s beyon

dth e scop e ofth e CWA . Thi s sectio n evaluate s th e applicabilit y o f installin g operationa

l an d technologica

l alternative s fo r th e existin g DCP

P coolin g wate

r system . Fo

r thos e applicabl e alternativ e technologies , w e provide additiona

l information relativ e to the potentia l cos t o f implementing th e technolog y an d th e possibl e reductio n o f

biologica l effects . Thes e technologie s includ e (1 ) cooling wate

r syste m alternatives , (2 ) intak

e configuration alternatives , (3 ) behaviora l an d physica l barriers , (4 ) fish collectio n an

dremova l conveyanc e systems , an

d (5 ) intak e maintenanc e an

d operationa

l modifications . 

## 6. 1 Evaluatio n Criteri a A hierarchica

l evaluatio n syste

mwa s use d to asses s whic

h alternativ e intak

e technologie s wer

e initiall y evaluate do

n the basi s ofth e following thre e criteri a(Figur e 6-1) : TENER A E9-055. 0 6- 1 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.3 4 6. 0 Alternative Intak

e Technologie s 1 . The alternativ e technolog y i s availabl e an d proven (i.e. , demonstrate d operabilit y an dreliabilit y a t acoolin g wate

r intak e simila r i n siz e an d environmen

t to th e DCP

P site) . 2 . Implementatio n ofth e alternativ e technolog y migh t result i n areductio n i

n th e los s o f aquati c organism s compare d t o th e present operatin g conditions . 3 . Implementatio n ofth e alternativ e technolog y i s applicabl e a t th e DCP P site , based o n site-specifi c consideration s o f engineering , operations , an d reliability . Fo r thos e alternative s tha

t meet th e thre e criteria , adetaile d evaluatio n o f applicabilit

y an d genera l cos t estimate i s describe di

n Sectio n 6-2 . All technologie s considere d an d th e applicatio n ofth e evaluatio n criteri aare show n i n Tabl e 6-1 . A brie f descriptio n an

djustificatio n fo

r th e alternative s tha

t d o no t mee t Criteri a1,2 , an

d 3 are presente di

n th e attache dAppendices . Appendix L - alternative s no t meetin g Criterio n 1 . Appendix M-alternative s no t meetin g Criterio n 2 . Appendix N-alternative s no t meetin g Criterio n 3 . 

## 6. 2 Applicabilit y Analysi s an d Cos t Estimate s Thi s sectio n discusse s th e applicabilit y o f each alternativ e intak

e technolog y tha

t ha s me t all thre e evaluatio n criteria . It i s divide d int

o tw o subsections : alternative s tha t reduc e impingemen

t an d alternative s tha

t reduc e entrainment . Fo r thos e alternative s presente di n previou s reports , th e cos t figure s presente d her

e represent thos e origina

l estimate s (TER

A 198 2 an d PG& E 1988a ) i n present da y dollar s a s o f

Decembe r 1999 . The annua

l cos t an dth e life-of-plan

t cos t figures presente d i

n thes e earlier

report s each consiste do f

tw o components : 1 ) capital , operation , an d maintenanc e cost s an

d 2 ) los t revenues . Othe r tha n considerin g th e changin g valu e o f labor an d material , th e capital , operation , an d maintenanc e cost s o f

an y ofth e alternative s wa s assume d no t t o hav e changed fro

mpreviou s estimates . To translate origina l cos t estimate s to present

da y values , w e used"representativ e indice s fro mth e Burea

u o f Labor Statistic s fo

r labo r an d material .

TENER A E9-055. 0 6- 2 Fina l 316(b ) Demonstratio n Marc h 1.200 0P.3 5 6. 0 Alternativ

e Intak e Technologie s Due to significan

t change s i n th e pric e of

electricit y sinc e th e origina

l estimates , th e lost

revenu e componen t wa s re-forecas t

usin g th e sam

e assumed los t

generatio n (MWe ) resultin g fro mloa d reductio n (deratings ) an

dlos t production , bu

t valued usin g arealisti c plan t capacit y facto r an d th e Californi aEnergy Commission' s forecas t o f Powe r Exchang e (PX ) pricin g fo

r the pric e o f electricit y fo r the nex t 2 5 yr . Fo r comparativ e purposes , th e cos t o f alternative s i s expresse d i

n ne t presen t valu e (NPV) , which include s th e tota

l capita l cost , th e cos t

ofth e cumulativ e los t

revenue , an

d increased maintenanc e cost s ove r th e lif e ofth e plant . Additionally , fo r th e alternative s tha

t reduc e impingement , th e cos t pe r k g offis h i s derive db

y dividin g th e tota

l NP V b y th e cumulativ e weigh

t (kg ) offis h impinge dfo

r eac h optio n ove

r th e remainin g licensed plan t life , assume d to b

e 2 5 yr . The cos t estimation s ar

e considere d t o b e accurat

e within a n orde r o f magnitude only . Mor

e accurat e estimate s wouldrequir

e detaile d an

d plant-specifi c desig n ofth e variou s technologies . Fo r example , neithe

r TER A (1982 ) no

r PG& E (1988a) considere d th e following costs , whic h wouldsubstantially ad

dt o th e current

estimates :

• Demolitio n an

d relocatio n o f

existin g utilities , syste

mcomponents , plan t facilities , buildings , etc . • Securit

y durin g constructio n an

d effec t o n permanen

t securit y boundary . • Nuclea

r licensin g (Licens e Amendmen t Reques t to the NRC) . • Permittin g (i.e . Californi aCoasta l Commission , RWQCB , etc.) . • Seismi c desig n considerations . Additionally , fo

r coolin g tower

cos t estimations , the following additiona l cost s wer

e no t considere db

y TER A (1982) :

• Tie-in wit

h existin g circulatin g wate

r conduits . • Chang e i

n pumping plan

t location , design , an

d configuration . • New circulatin g wate

r pump s (CWP) an

d syste mcomponents . • Change s i

n th e turbin e an

d condensat

e system s to accommodat

e highe r coolin g wate

r temperatures . • Sal t wate r drif t damag e to existin g plan

t facilitie s o

r structure s an

d t o electrica

l or mechanica

l equipment . TENER A E9-055. 0 6- 3 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.3 6 6. 0 Alternative Intak

e Technologie s

• Sal t wate r drif t damag e to surroundin g lands , terrestria l habita t an d ecology , an

dagricultura

l productivity . Therefore , th e cos t

estimate s provide d i

n thi s repor

t ar e considere d approximate , likely t o b e conservativ e (low ) an

dadequate a s orde

r o f magnitude estimates . 

### 6.2. 1 Alternative s Tha t Reduc e Impingemen t Losse s Onl y The impingemen

t rate a t DCP P i s low , based o

n 1985-8 6 impingemen

t dat aan d ongoin g field observation s (Sectio n 5.1.2) . I n th e 1985-8 6 stud

y (Tener a1998a

) impingemen

t rate s wer e estimate da

t about 0.3 2 t o 0.7 3 kg/day/unit . Diver s observ e fishe s and invertebrate s freel y movin g withi n th e intak

e structure forebay s an

d directl y i

n front ofth e travelin g screen s (Tener a 1997a) . Therefore , modification s t o th e intak e structur e ca n provid e littl e improvemen t i n reducin g th e numbe

r o f impinge dfish. Th e following discussion , however , provide s informatio n o n possibl e alternativ e technologie s to reduc e impingemen t a t DCPP , thei r

estimate d costs , an

d th e compariso n o f

cost s t o potentia

l impingemen

t reductions . 

### 6.2.1. 1 Increase d Are a Intak e Structure A detaile drevie w ofth e intak e velocitie s a

t DCP P (Wyma n 1988) , th e literatur

e o n laborator

y swimmin g performanc e o f

juvenil e fish (reviewe d i

n Tenera1998a) , an

d dive r observation s o f impingemen

t avoidanc e a

t th e DCP P intak e (Behren s an

d Larsso n 1979 ) showed tha t fish impingemen

t shoul db e virtuall y independen t o f intak e approac h velocitie s o f

les s tha n about 0. 8 t o 1. 0 fp s (present

velocit y a t DCPP) . Based o

n studie s a t ContraCostaStea

mPlan t (Ker r 1953 ) impingemen

t i s predicte dt o increas e a

t intak e approach velocitie s greate r tha n 1. 5 fps , particularl y among juvenil e fish tha t ar e les s tha n approximatel y 8 0 m

mi n length . A reductio n i

n approac h velocitie s i s not

expecte dt o substantially reduc e fish impingemen t rate s a t DCPP . However , one approac h t o possibly reduc e impingemen t would b e t o reduc e th e intak e approac h velocity . Th

e approach velocit

y i s inversely proportiona

l t o th e cross-sectiona

l are athrough which the wate

r passes . Therefore , velocitie s enterin g th e intak e structur e ca n b e reduce d b

y increasin g the cross-sectional are aexposed to th e flow . Reductio n i n th e intak e approach velocit y wouldrequire expansio n ofth e intak e structure includin g additiona l travelin g screen s t o

TENER A E9-055. 0 6- 4 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.3 7 6. 0 Alternativ e Intak e Technologie s increas e th e intake' s cros s sectiona l area . A design tha

t halve s the existin g approach velocit y wa s considered . Thi s desig n chang e assume s tha t reduced flo

w velocit y translate s t o reduce d impingement . A leve l o f uncertaint y exist s aroundth e us e o f

asingl e paramete

r suc h a s flow rat

e or velocit y to accuratel y predic t

th e potentia

l fo r reducin g impingement . Taf t (1999 ) compare s severa

l site s wit h simila r intak e design s an

dflow characteristic s tha

t experienc e larg e difference s i n impingement . Highe

r rate s o f flow an d intak e velocit y (through th e travelin g screens ) ar e usually associate dwit

h highe r impingemen

t losses . Taf

t (1999 ) illustrate s fromth e availabl e datatha t neither'velocit

y no r flo w appea r t o b e closely correlate d t o impingemen t rates . H e conclude s tha

t impingemen

t shouldb e viewe da s asite-specifi c even t ma t i s influenced b

y man y parameters . It i s th e combination s o f

environmenta

l condition s an

d specie s lif

e stage s tha

t interac t t o influenc e impingement . Pla n an dsectio n view s ofth e propose d modification t o th e intak e structur e ar e presente d i

n Figure s 6- 2 an

d6-3 . A s indicate di

n thes e figures , th e modification would involv e expandin g th e intak e structur e toward s th e ocea

n side wit h approximately 45 ° flar

e an d deepenin g th e existin g intak e inver t sla b elevatio n to (- ) 46. 0 feet . Constructio n ofth e expande dintak e structur e would result

i n amajo r constructio n effor

t an d requir e installin g acofferda

man ddewaterin g th e existin g intak e structure . Disruptio n associate d wit h constructio n an

ddredgin g activitie s would contribut e t o localize d impact s o

n kelp an d benthi c organism s inhabitin g th e Intak e Cove . Durin g intak

e construction , th e circulatin g wate r flo w require d fo

r th e operatio n o f

Unit s 1 an

d 2 woul db e disrupted , resultin g i n acomplet

e los s o f generatin g capabilit

y fro mbot h unit s fo r a perio do f approximately one year . Operatin g one uni t whil e modifying th e othe

r unit would not chang e th e cumulativ e revenu e los s appreciably , becaus e th e constructio n duratio n fo r eac h unit wouldno t chang e substantially . A majo r challeng e t o an

y constructio n projec t

i n fron t ofth e existin g intak

e structur e wouldb e th e potentia

l fo r stor mcondition s interferin g wit h wor k i n the intak e bays .

TENER A E9-055. 0 6- 5 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.3 8 6. 0 Alternativ e Intak e Technologie s Whil e th e units ar

e shutdown , th e auxiliary saltwate r (ASW ) syste m woul d hav e t o remain operabl e t o preserv e th e functio n o f thos e system s necessar y t o maintain th e planti n a saf e shutdow n mod e an

d protectth e nuclea r fuel . Therefore , a n extensio n ofth e AS W syste m woul d b e required t o provid e continuou s flow t o th e AS W pumps . Sinc e th e AS W syste m i s a nuclea r safety-relate d system , necessar y safety-relate d desig n consideration s such a s seismi c safety , contro l o f

heav y loads , an

d interactio n betwee n safety an d non-safet

y relate d item s woul d hav e t o b e evaluate d a s par

to f intake structur

e desig n an

d modification . Prio r t o finalizin g th e desig n ofth e expande d intake structure , a detaile d engineerin g evaluatio n woul d b e necessar y t o ensur e compatibility betwee n hydrauli c flow patterns , coolin g wate r volumes , an

d pressure regime s associate d wit h th e expande d intake structur e an d th e existin g Unit s 1 an

d 2 condense r system . Licens e amendments required t o accommodate a modificatio n suc h a s thi s hav e no tbee n reviewed . Additionally , othe r environmenta l an d safety desig n consideration s suc h a s th e effect s o f earthquakes , tsunamis , an d probabl e maximum load s woul d require evaluation . Thes e woul d resul tin additional cost s tha thav e notbee n factore d into th e followin g cos testimates . Th e estimate d capital cos tfo r thi s projectwoul d b e o n th e order o f $51,000,000 . I

n addition , th e cumulativ e los trevenu e an d increase d maintenanc e woul d b e approximatel y $590,000)00 0 ove r th e lif e ofth e plant . Th e implementatio n o f thi s technolog y ha s a ne tpresentvalu e (NPV ) o f (- ) $275,000,000 . Thi s results in a cos to f $61,70 0 t o sav e each kilogra m o f impinge d fish, assumin g a 100 % reductio n in impingemen tove r th e remainin g lif e ofth e plant . 

### 6.2.1. 2 Angle d Scree n Intak e Structur e Angle d travelin g scree n intake s ar e designe d wit

h conventiona l screen s se ta ta n angl e t o th e incomin g flow . A fish diversio n syste m i s installe d a tth e downstrea

m end ofth e intake such tha t incomin g fish ar

e directe d alon g th e fac e ofth e screen s t o th e fish diversio n path . Fis h diversio n system s includ e variou s design s o f pivoting , fixed , o r travelin g screens , louvers , associate d wit h traditiona l ba r racks .

TENER A E9-055. 0 6- 6 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.3 9 

# I I

I I 6. 0 Alternativ e Intak e Technologie s Thes e intak

e design s have bee

n utilize d i

n bot h hydroelectri c an

d therma l powe r statio n intake s t o minimiz e impingement . A t Brayton Poin

t Statio n Unit

4 i n Massachusetts , a

n 1 8 m o (Octobe r 1984 t o March 1986 ) biologica l evaluatio n wa s conducte d to determin e th e species , number , an d initia l an dextende dsurviva

l offis h diverte d fro

mth e angled scree

n intak e (Davi s et

al . 1988) . The angle dscreen intak

e syste mha d ahig h diversio n capabilit

y an d demonstrate d effectivenes s fo r mitigatin g fish impingement . Initia l an d extende d surviva

l varie d b y species ; however , a certai n grou

p o f numerically dominan

t tax awa s classifie d b

y th e author s a s "fragile " (primarily , ba y anchovy an

dAtlanti c silverside) . Th

e fragile grou

p ha d acalculate d surviva

l belo w 2 5 percent an da"hardy " group , dominate d b y winte r flounde r an d norther n pipefish , ha

d surviva l value s greater

tha n 6 5 percent . The diversio n efficienc y fo r all specie s combine d wa s 7 6 percent . Nin e ofth e to p 1 2 tax acollecte dha d diversio n efficiencie s greate r tha n 8 3 percent . The diversio n flow collection s resulte d i n a n initia l surviva l rate o f 5 8 percen t fo r all tax a(n = 28,186 ) combined . The initia

l surviva l rat e range d from 6 percen

t fo r ba y anchovy t o nearly 10

0 percen t fo r America n eel . Initia

l surviva l wit h th e exclusio n o f

ba y anchov y wa s 8 3 percent . Extende d surviva l fo r all fish (n=9,209 ) collecte d a t th e diversio n flow wa s 6 3 percent . Extende d surviva l trend s wer e simila r fo r th e majo r specie s involved . Surviva

l ranged fro

malow (ba

y anchovy ) o f 0 percent t o ahigh ove

r 9 9 percen t (tauto g wrasse) . Osweg o Stea

mStation Unit

6 utilize s a

n angle d scree

n diversio n syste

msimila r t o th e syste

ma t Brayto n Poin

t Statio n (LM S 1992) . Biologica l studie s wer

e conducte d t o investigat

e th e effectivenes s ofth e screen s a s systems . Alewif e (herring ) an

d rainbo w smelt

mad e u p 9 0 percen

t ofth e collecte dspecie s (fro mApril 1981-March 1983) . Diversion efficiency wa s 7 9 percen t an d 7 4 percen t fo r alewif e an drainbo w smelt , respectively . Th e combined diversio n efficiency fo r all th e specie s collecte dwa s 7 8 percent , rangin g fro m5 3 percen

t fo r mottle d sculpin t o 9 5 percen t fo r gizzar dshad . Initia

l surviva l ranged fro

malo w o f 4 5 percen t fo r rainbo w smelt

to ahig h o f 87 percen t fo r emeral dshiner . A tota

l o f 34,29 4 individual s fro

mth e seve

n mos t frequentl y collecte dspecie s wer

e examinedfo

r initia l survival , an

d 7,53 4 fish wer

e observe d fo

r laten t survival . Th

e lowest laten t surviva l rat e wa s exhibite d b

y alewif e (2 2 percent) whil e th e highes t wa s mottle dsculpin (9 4 percent) . Overall , th e angled scree n syste mwa s effective i

n divertin g

TENER A E9-055. 0 6- 7 Fina l 316(b ) Demonstratio n Marc h 1,200 06. 0 Alternativ e Intak e Technologie s fish fro m th e primar

y screenwel l throug

h th e secondary screenwel l back into th e lake . Th e degre e o f effectivenes s varie d widel y b y species ; siz e clas s or age , an d conditio n ofth e population . A full-scal e angle d scree n tes tfacility wa s constructe d a tth e Danskamme r Poin tGeneratin g Statio n o n th e Hudso n Rive r in 198 1 (LM S 1985) . Th e angle d scree n facilit y wa s locate d i n th e coolin g wate r intake cana l an d consiste d o f

tw o 3 m (1 0 ft) wid e vertical travelin g screen s se ta t a 2 5 degre e angl e t o th e approac h flow. Th e effectivenes s ofth e syste m wa s evaluate d ove r a thre e yea r tes tperio d (LM S 1985) . Diversio n efficienc y ranged from 9 5 t o 10 0 percent , with a mea n o f 9 9 percent . Specie s include d ba y anchovy , bluebac k herring , whit e perch , spottai l shiner , alewife , Atlanti c tomcod , pumpkinsee d (sunfish ) an d American shad . Overall , syste m efficienc y (diversio n efficienc y time s initial surviva l time s latent[9 6 h ] survival ) ranged fro m 6 8 percent(alewife ) t o 9 9 percent(spottai l shiner ) with a mean o f 8 4 percent(LM S 1985) . Angle d travelin g scree n intake structure s hav e bee n use d in a marine environmen tan d ar e wel l suite d fo r reducin g impingement . Wav e energ y an d debri s loadin g event s tha toccu r a tDCPP wer e probabl y no texperience d a tfacilitie s tha

thav e installe d thes e screens . Angle d scree n intake s d o no tpreven tentrainmento f larva l organisms . On e featur

e o f angle d scree n intake s i s tha tth e velocitie s norma

l t o th e screen s i s quite low , o n th e order o f

0.0 3 m/ s (0. 1 ft/sec ) t o 0.1 5 m/

s (0. 5 ft/sec) (EPR

I 1999) . Implementatio n o f a n angle d scree n intake a

tDCP P woul d requir

e a majo r reconstructio n ofth e intake t o accommodat e additional (atleas ttwic e th e number currently installed ) screen s i n th e angle d configuration . Althoug h a specifi c desig n an d cos testimat e ha s no

tbee n prepare

d fo r thi s configuration , i

ti s judge d tha

tth e cost s woul d b e simila r t o th e cost s associate d wit h th e expande d area intake describe d i n Sectio n 6.2.1.1 . Sinc e thi s alternativ e addresse s onl y impingement , th e cost s compare d t o th e reported impingemen trat e woul d notmake thi s optio n cos teffectiv e fo r implementatio n a tDCPP . 

# I §

TENERA E9-055. 0 6- 8 Fina l 316(b) Demonstratio n Marc h 1,200 06. 0 Alternativ e Intak e Technologie s

6.2.1. 3 Travelin g Scree n Operatin g Cycl e Modification s an d Fis h Conveyanc e System s Operationa

l modification s t o th e vertica l travelin g screens , such a s th e us e o f continuou s screen rotation , screen basket s wit h "fis h buckets" , low-pressur e spraywash , an

d fish retur

n sluiceways , ar e alternative s tha

t hav e bee n proposed b

y the industr

y to increas e th e biologica

l effectivenes s o f conventiona

l vertica l travelin g screens . Typically , all o f thes e element s mus t

b e used togethe

r t o effectivel

y reduc e impingemen

t mortality . Cost s fo

r th e combinatio n o f

modification s ar

e presente di

n th e sectio n o

n Combinations of

Vertical Traveling Screen Modifications (below) . Continuous

Traveling

Screen Rotation Severa l studie s hav e bee

n performed to determin e th e effectivenes s o f continuou s screen rotatio n o n impingemen

t survival . Studie s conducte d a t th e Pittsburg Powe

r Plan t (PG& E 1992) sho w tha t increasin g th e screen rotatio n frequency fro m3 h interval s t o continuou s rotatio n did not result i n consistently improve dimpingemen t surviva l fo r invertebrate s suc

h a s Californi aba

y shrimp , brackish-wate

r crabs , an dorienta l shrimp . I n contrast , mor

e (26-56 % afte

r 9 6 h ) young-of-the-yea

r (YOY ) whit

e perc h (Morone americana) survive dimpingemen t o n continuously operatin g travelin g screen s compare d t o thos e operate d2- 4 h intermittentl y (19-32 % surviva l afte r 9 6 h) . Likewise , stripe d bas s (Morone saxatalis) laten

t surviva l improved (32-62% ) afte

r impingemen

t o n continuously operatin g screen s compare dt o bas s impinge d o n intermittently operate d screen s (26 % afte r 9 6 h ; King et al . 1978) . King e

t al . (1978 ) conclude d continuou s travelin g scree n operatio n allowed maximu m initia l an dlaten t surviva l fo r whit e perc h an d stripe d bas s YOY . Continuou s scree

n rotatio n di dnot

consistently result

i n improved impingemen

t surviva l ofth e marine organism s examine da t the Mos s Landing Powe

r Plan t (PG& E 1988a, Section 4.2) . Amon g impingedfish, hard

y specie s suc

h a s plainfi

n midshipma

n an d crab s ha d ahigh rat

e o f surviva l regardles s o f

screen rotatio n frequency . Increasin g scree n rotatio n frequency a

t th e Mos s Landing Unit s 6 an

d7 intak e did , however , contribut

e t o asubstantia

l increas e i

n impingemen

t surviva l fo r bot h surfperc h an drockfish , whic

h togethe r constitut e abou t 1 1 percen t (b y weight) ofth e fish impingeda

t DCP P (PG& E 1988a, Section 4.2) . TENER A E9-055. 0 6- 9 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.4 2 6. 0 Alternativ e Intak

e Technologie s Th e studie s reference dabov e sho w tha t impingemen

t surviva l varie s fro

msite t o site an

d i s specie s specific . Testin g o f continuou s screen rotatio n a t DCP P would b e require d t o detennin e if areductio n i

n impingemen

t i s achievable . Th e current

debri s remova

l syste ma t DCP P i s designe d t o handl e larg e quantitie s o f kel p an d other debris . The materia

l washe dfromth e screen s i s washe d t o asluicewa y an d directe d t o a larg e sump . Thi s materia

l andwas h wate

r i s pumpe d t o alocatio n approximately 24 4 mnort h o f th e intak e structure a

t th e shor e en dofth e wes t

breakwater . Grinder s ar

e installe d a

t th e entranc e t o th e refus e sum

p t o reduc e th e siz e ofth e kel p an d alga l debri s t o preven

t cloggin g ofth e debri s remova l system . N o impingemen

t surviva l i s expecte d wit

h thi s system . Thi s syste

mi s neede d to suppor t plan t operatio n wit

h th e hig h debri s loads . Increasin g intak e screen rotatio n offer s th e possibilit y o f increasin g surviva

l o f som e impinge d organism s onl y if thi s metho d i s use d i

n conjunctio n wit

h other modification s (such a s agravit y sluicewa

y an d fish basket s t o increas e survival) . Thes e configuration s ar e describe d i

n th e next tw o sections . Gravity Sluiceway

Fish Return and Low Pressure

Spraywash Ther e ar e tw o basi c type s o f

sluiceway s fo

r th e retur n o f impinge d organism s an

d debri s t o th e waterbody : on e use s apum p t o transpor

t collecte d materia

l awa y fromth e intak

e an d on e use s gravit y flow. Basedo

n th e existin g DCP

P intak e design , agravit

y retur n sluicewa y directin g flow to th e sout

h en dofth e intak

e would b e th e leas t

comple x an

d leas t expensiv e option . A s describe di

n th e previou s section , th e current DCP P screenwas h syste

mi s not designe d t o retur n impinge dorganism s to th e receivin g waterbod y intact . The hig

h debri s loadin g experience da

t DCP P require s tha

t thi s syste mfunction i

n awa y tha t make s impingemen

t surviva l unlikely , an

dhenc e no surviva

l o f impinged organism s i s expected . T o increas e impingemen

t surviva l a t DCPP , aseparat

e fish retur

n trough , lo

w pressur e spra y wash , an dfish collectio n basket s a s describe d i n th e nex t sectio n would b e required . Base d o n constructio n estimates , th e implementatio n of alo w pressur e spra y wash an d fish retur

n syste m wouldcos t

about o f $12,000,000 . NP

V analysi s fo

r thi s modificatio n i

n conjunctio n wit

h replacin g screen basket s i s includedi n the nex t section .

TENER A E9-055. 0 6-1 0 Fina l 316(b ) Demonstratio n Marc h 1,200 06. 0 Altemativ e Intak e Technologie s

Combinations

of Vertical Traveling

Screen Modifications Severa l modification s t o conventiona l vertica l travelin g screen s hav e bee n studied i n recen t year s i n a n attemp t t o reduc e th e mortalit

y o f impinged organism s b

y incorporatin g ne

w desig n feature s tha

t improv e th e surviva

l o f impinged organisms . Suc

h state-of-the-ar

t modification s ac t t o enhanc e fish an

dinvertebrat

e surviva l relate d to screen impingemen t an d spraywas h removal . Screen s modifiedi

n thi s manne

r ar e commonl

y calle d "Ristrop h Screens" . Thes e modification s include th e following features : 1 . Hydrodynamically improved , watertigh t fish collectio n bucket s alon g th e bas e o f each screen panel t o provide aholdin g are afo r organism s durin g scree

n rotation ; 2 . Smoot

h wove n mesh (e.g . 1.6 m

mb y 12. 7 m mrectangula

r mesh ) installe d o

n th e screen basket s t o minimiz e abrasion ; 3 . Lighte

r composit e screen basket s which allo w fo r increase d rotationa

l speed ; 4 . A secondsluiceway/fis h retur n syste mwit h combined low pressur

e spra y wash t o transpor t organism s removed fro

mth e screen b y th e low-pressur e spraywas h bac

k t o th e receivin g waterbody ; 5 . Improve dscreen-to-collectio n trough flap sea l design ; an

d 6 . Modification s t o travelin g scree n bearing s an

d motor s t o permit

continuou s rotatio n an dcleaning , minimizin g th e time a n organis mi s impinged o

n th e screen . Studie s ofth e biologica

l effectivenes s using thes e modified Ristoph screen s wa s conducte d a t th e Sale mGeneratin g Statio n o

n Delawar e Ba y i n New Jersey (Ronafalv

y e t al . 1999 ; Heimbuc

h 1999) . A n initia l evaluatio n wa s performed afte r si x ofth e 1 2 existin g travelin g wate r screen s a t th e coolin g wate

r intak e structur e ha d bee n replace d wit

h th e new , improved screens , allowin g a side-by-side compariso n ofth e effectivenes s ofth e old an d ne w screens . Test s wer

e conducte d o n 1 9 separat

e date s betwee

n June 20 an

d Augus t 24 , 1996 . Fish collecte d fro mthe old an

d ne w screen s wer

e heldseparately fo

r observatio n of

4 8 h survival . Th

e onl y specie s occurrin g i

n sufficien t number s to provide astatisticall y vali d dataanalysi s wa s juvenil e weakfish (Cynoscion regalis; n = 108 2 fo

r th e oldscreens , n = 155 9 fo r th e ne w screens) . Overall , statistica l analyse s demonstrate da4 8 h surviva l rat e (uncorrecte d fo

r contro l mortality ) o f

57. 8 percen

t wit h the old screen s an d79. 3 percen

t wit h the ne w screens .

TENER A E9-055. 0 6-1 1 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.4 4 6. 0 Alternativ e Intak e Technologie s A secondserie s o f

impingemen

t surviva l studie s wa s conducte d i

n 199 7 an d 199 8 to provide estimate s o f

impingemen

t surviva l rate s wit h al l 1 2 ofth e modified screen s installe d o n Sale m Unit s 1 an

d2 (EPR I 1999) . Whit

e perch (Morone americana) impingemen t surviva l rate estimate s rangedfro

m9 8 percent

i n Decembe

r to 9 3 percen

t i n April . Estimate s fo

r weakfish range dfro m8 8 percent

i n Septembe

r t o 1 8 percen

t i n July . Fo r ba y anchovy (Anchoa mitchilli), surviva l estimate s range dfro

m7 2 percen

t i n Novembe

r t o 2 0 percent

i n July . Atlanti c croaker (Micropogonias undulatus) surviva l estimate s range d fro

m9 8 percent

i n Novembe

r to 5 8 percent i n April . Th e estimate dsurviva l fo r spo t (Leiostomus xanthurus) wa s 9 3 percent i n Novembe r (Novembe

r wa s th e onl y mont

h i n which asignifican

t numbe r o f spo t wer e collected) . Alosa specie s (herrings ) combine dproduce d surviva l estimate s tha

t range d fro

m8 2 percent

i n Apri l t o 7 8 percent

i n November . Impingement

mortalit y rate s fo r th e modified screen s (199 7 an d 199 8 studies ) wer

e compare d t o mortalit y rate s fo r th e origina

l screen s fro

mth e 197 8 to 198 2 studies . Based o n th e comparisons , intak e modification s wer

e effectiv e i

n improving th e rate s offis h survival . Estimate s o f impingemen

t mortalit y rate s wer

e lowe r fo r th e modified screen s tha

n fo r correspondin g estimate s fro

mth e origina

l screen s fo

r whit e perch , ba

y anchovy , Atlanti c croaker , spot , an d th e Alosa species . Basedo n impingemen

t surviva l dat acollecte d a

t th e Diabl o Canyon an

d Mos s Landin g powe

r plant s an da t other facilities , i

t wa s conclude d tha

t operatio n o f

modified intak

e screen s i n combinatio n wit

h fish retur

n sluiceway s coul d enhanc e impingemen t surviva l o f man y ofth e fish an dmacroinvertebrate s impinge da t DCPP , includin g skate s an d rays , rockfish , sculpin , plainfin midshipman , tubesnouts , roc k crabs , an d se aurchin (PG&E 1988a) . O n th e basi s o f

data collecte di n th e impingemen

t surviva l studie s (PG&E 1988a) , i

t wa s estimate d tha

t losse s o f impinge dfish an

dselecte dmacroinvertebrate s ma y potentiall y b e reduced b

y approximatel y 7 5 percen t unde r condition s o f

intermittent

rotation , assumin g n o incrementa l mortalit y associate d wit h passag e throug h th e fish retur n system . Rotatin g intak

e screen s continuously coul d reduc e impingemen

t losse s offis h an

dselecte d macroinvertebrates , assumin g no incrementa l mortalit y resultin g fro

mpassag e throug h th e fish retur n system . I

n ligh t o f DCPP' s lo

w impingemen

t rate ,
TENER A E9-055. 0 6-1 2 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.4 5 6. 0 Alternativ

e Intak e Technologie s however , thi s percentag e reductio n will not result i n a n appreciabl e biologica

l benefit . Th

e scree n improvement s ar

e not expecte d t o provide an

y reductio n i

n entrainment . Travelin g scree

n modification s to reduc e impingemen t mortalit y mus t b e accompanie d b

y a sluicewa y designedto retur

n organism s t o th e receivin g waterbody . Mos t installation s o f modifiedtravelin g screen s us e adua l sluicewa y retur n system : 1 ) agravit

y sluicewa y retur n syste mfo r impingedorganism s removed fro mth e screen s b

y th e low pressur

e spraywas h an

d 2 ) anothe r sluicewa y fo r debri s remove d by th e high-pressur e spraywash . Thi s typ e o f

syste mwa s selecte dfo r thi s evaluation . Th e estimate dcapita

l cos t fo r thi s projec t

would b e o

n the orde r o f $13,000,000 . I

n addition , th e cumulativ e los t

revenu e an

dincrease d maintenanc e would b e approximately $11,000,00 0 ove r th e lif e ofth e plant . The implementatio n o f thi s technolog y ha s ane

t presen t valu e (NPV ) o f (- ) $11,000,000 . Thi s result s i n acos t o f a t leas t $2,20 0 t o sav e eac

h kilogra mo f impinged fish assumin g a100 % reductio n i n impingemen

t overth e lif

e ofth e powe

r plant . The scop e o f implementin g thi s alternativ e i s expecte d t o extend th e duratio n o f routin e refueling outages , addin g additiona

l cost s tha t hav e no t bee n factored i

n to th e estimates . 

### 6.2. 2 Alternative s Tha t Reduc e Entrainmen t Losse s The majo r focu s o f thi s stud y concern s losse s to fish an d invertebrat

e population s caused b

y withdrawa l of larva l stages . A majorit

y ofth e young larva

e ar e wea k swimmer s an

d cannot escap e eve n ver y lo w entrainment

velocities . I

n orde r to reduc e entrainment , alternative s tha t us e les s coolin g wate

r ar e considered . The following discussio n provide s information o n possibl e altemativ e technologie s to reduc e entrainmen t a t DCP P an d th e estimate d cost s t o install them . 

### 6.2.2. 1 Closed-Cycl e Coolin g Towers Wit h Saltwate r Makeu p Bot h mechanica

l an dnatura l draf t (hyperbolic ) cooling tower s usin g saltwate r makeu p wer e evaluate dfo

r applicabilit

y a t DCP P (TER A 1982) . Operationa

l problem s an

d environmenta

l consideration s (includin g air qualit y impact s fro

mcooling towe

r drif t an d effects o n vegetatio n fromsal t deposition ) have limite d th e applicatio n of closed-cycl e coolin g wher e brackis h wate

r TENER A E9-055. 0 6-1 3 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.4 6 6. 0 Alternative Intak

e Technologie s

o r saltwater i s useda s amake-up source . Th e repor t conclude d tha

t n o operatin g o r

propose d electri c generatin g facilitie s i n th e Unite d State s us e seawate r i n closed-cycl e coolin g systems . Sinc e tha t repor t wa s written , natura

l draf t coolin g tower s wit

h saltwater

makeu p hav e bee n installe dan

doperate da

t Crysta l Rive r unit s 4 an d 5 . Tw o coolin g tower s provide coolin g fo r th e tw o 75 0 M

W coal-fire dunits . Th e tower s ar e operate d wit

h ahigh blowdown rate (10%) , suc h tha t th e total saltwate

r deman dfro

mth e ocea

n i s reduced approximatel y 8 0 percen t compare d t o aonce-throug h system . Therefore , saltwater coolin g towers , either

wit h mechanica

l or natura l draft , hav e bee

n demonstrate do

n th e scal e require d fo

r aclosed-loo p systema

t DCPP . Base do n th e Crysta

l Rive r experience , th e us e o f

closed-loo p coolin g tower s wit h saltwate r makeu p a t DCP P wouldreduc e th e coolin g wate r flow rat e b y 8 0 percent

(fro m1. 6 Mgp

mt o 0.3 2 Mgp mper unit) , reducin g entrainment by asimila

r percentage .

• • . . • .10' . . . • •. . Conceptua l design s anddesig n parameter s fo r bot h mechanica

l draf t (Figur e 6-4 ) an

d natura l draf t coolin g tower s (Figure 6-5 ) hav e advers e environmenta l impact s o

n ai r an d wate r quality , lan d use , an daesthetic s (TER

A 1982) . • Ai r Qualit y —Would produc e 3 7 h/y r o f groun d level fog , visibl e vapo r plume and emi t

ca . 6,080-9,07 0 kg/

d o f sal t drift . • Wate r Qualit y —Would increas e salinit y o f coolin g wate

r discharg e by 1.5 times , wors t

case ; effluen

t limitation s coul d b e exceede d if a treatment systemi s no t

installed . • Lan dUs e —Would requir

e a n additiona

l 1 2 t o 2 2 h

afo r coolin g towers . Additionally , th e terrestria l impact o f salt drif t would b e significant downwind ofth e plan

t site , a s well a s t o th e plan

t facilities . • Aesthetic s —Fo r

ahyperboli c (natura

l draft ) syste mwit h tw o 14 2 mdiameter

x 17 0 mhigh coolin g towers , th e vapor plume s coul d reach 1,000-2,00 0 mhigh . Fo r amechanica

l draf t syste mwit h six 9 4 mdiameter

x 2 2 mhig

h coolin g towers , th e vapor plume s coul d reac h 100-20 0 mhigh . Th e estimate dcapita

l cos t fo r th e hyperboli c syste

malternativ e i s o

n th e orde r o f $658,000,000 . I n addition , th e cumulativ e los t revenu e an

d increase d maintenanc e would b e approximatel y (- ) $454,000,00 0 ove r th e lif e ofth e plant . Th e NP

V o f thi s alternative' s cost s i s (- ) $503,000,000 .

TENER A E9-055. 0 6-1 4 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.4 7 6. 0 Alternativ

e Intak e Technologie s Actua l project cost s woul

db e highe r tha n th e estimat

e a s th e us e of

aclosed-loo p coolin g syste m wouldrequir

e majo r design change s to th e DCP P turbin e plant . Th

e present circulatin g wate

r pump s (CWP ) ar

e to o larg e t o suppl

y acoolin g tower

system , s o ne

w coolin g towe

r makeu p pump s woul db e required . A ne w se t o f coolin g tower

suppl y pump s o f

simila r capacit y to the existin g circulatin g wate

r pump s would hav e t o b e installe d i n ane w pumpin g facility . Suppl

y an d retur n wate r conduit s wouldals o hav e t o b e constructed . Sinc e th e DCP P main condense

r an d turbin e cycl e ar

e designe dt o operat

e wit h coolin g wate

r temperature s between 1 1 an d 14°C , extensiv e redesig n an

dretrofittin g ofth e condense r an d othe r turbin e system s woul d b e require d t o allo w reliabl e plan

t operatio n wit

h closed-loo p coolin g wit

h asuppl y temperature o f

2 6 t o 31°C . Th e cost s o f

thes e modification s ar

e no t included i n thi s estimat

e an d woul d ad

d substantiall y t o th e overall cost . 

### 6.2.2. 2 Closed-Cycl e Coolin g Tower s wit h Freshwate r Makeu p A closed-cycl e coolin g syste musin g freshwater

makeu p i s awel l proven technolog y used a t man y differen t nuclea r an dfossil powe

r plant s o n ascal e simila

r t o tha t require d a

t DCPP . A conceptua l desig n i s outline di

n thi s report . A freshwate

r coolin g towe

r syste mwould requir

e approximately a132,500 m 3 / d (9 2 m

3/min ) makeu p wate r supply . Thi s correspond s to 43-4 9 millio n m 3 of freshwate r pe r year . Ther

e i s no supply o f fres h wate r (includin g sanitar

y treatment

plan t effluent ) within 4 0 k

mo f DCP P availabl e to supply coolin g towe r makeu p (TER A 1982) . A multistag e flas

h distillatio n plan

t coul d supply th e neededfres h water , a s coul d arevers e osmosi s syste mo f simila r capacity . Bot

h flash distillatio n an

drevers e osmosi s system s hav e bee n constructe d o

n ascal e needed t o suppor

t fresh wate

r coolin g tower s a

t DCPP . Environmenta

l impact s ar

e simila r t o thos e describe d fo

r the closed-loop coolin g towe r wit h saltwater makeu p except tha t th e us e o f fres h wate r would reduc e the emissio n o f particulate s to approximately 1,54

0 kg/d . 

# I TENER A E9-055. 0 6-1 5 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.4 8 6. 0 Alternative Intak

e Technologie s Th e us e o f

freshwate r coolin g tower s woul d reduc e th e required saltwate r flow fo r condense r coolin g from ca . 9. 5 millio n m 3 / d (10 1 m 3 /sec ) t o ca . 0. 4 millio n m 3 / d ( 5 m 3 /sec) . Thi s woul d reduc e intake flow b y 9 5 percent , reducin g entrainmentb y a simila r amount . Th e constructio n effor

tinvolve d woul d b e simila r i n cos tt o th e saltwate r system s describe d previously , excep tfo r th e additional cost s fo r a desalinatio n planto f sufficien tcapacity t o suppl y coolin g towe r makeup . Th e estimate d capital cos tfo r thi s alternativ e i s o n th e orde r o f $1,174,000,000 . I

n addition , th e cumulativ e los trevenu e an d increase d maintenanc e woul d b e approximatel y $1,367,000,00 0 ove r th e lif

e ofth e plant . Th e ne tpresentvalu e o f thi s alternative' s cost s i s (- ) $1,072,000,000 . i Th e us e o f

saltwate r o r freshwate r closed-loo p coolin g towe r system s woul d reduc e saltwate r flo w b y 8 0 t o 95% , reducin g entrainmentan d impingemen tb y a simila r amount . Coolin g towe r technolog y i s prove n a

tmany powe r plants , saltwate r coolin g towe r operatio n ha s bee n demonstrated , an

d desalinatio n plants o f

a siz e neede d fo r freshwate r coolin g tower s hav e bee n constructed . Th e implementatio n o f a closed-loo p syste m a

tDCP P woul d require a substantial desig n an d constructio n effort . Th e cost s o f retrofittin g a closed-loo p syste m a tDCPP (whic h rang e in ne tpresentvalu e fro m (- ) $503,000,00 0 t o (- ) $1,072,000,00 0 no tincludin g permittin g challenge s an

d extensiv e plantmodification s t o ensure reliabl e plan toperatio n wit

h coolin g tower s installed ) woul d b e difficul tt o justify , especiall y considerin g m e uncertai n valu e ofth e plant' s electrica l outputa s Californi a deregulate s electri c generation . Althoug h i twoul d b e possibl e t o instal l a closed-loo p coolin g towe r system , i ti s doubtfu

l tha ta n investmen tofth e typ e describe d abov e woul d b e viabl e i n th e curren

to r futur e electrica l generatio n market. 

### 6.2.2. 3 Fin e Mes h Screen s Fine-mes h screening , frequentl y use d i n centerflo w screens , has bee n investigate d i n laborator

y studie s t o determin e its potentia l t o minimiz e entrainmenta tpowe r plantintake s (Maglient e et al . 1978) . Application-specifi c studie s ar e necessar y t o evaluate th e survival offis h egg s an d larvae impinge d o n fine-mes h screens .

TENER A E9-055. 0 6-1 6 Fina l 316(b) Demonstratio n Marc h 1.200 0P.4 9 

# fi I I I fi I V fi I I I I I I f 1 I I 1 6. 0 Alternativ e Intak e Technologie s Information fro

mlaborator

y test s (Tomljanovich et

al . 1978 ) show s tha

t travelin g screen s equippedwit

h 1. 0 m m(0.04 in) scree

n mesh would substantially reduc e entrainment offis h egg s an dlarva e a t DCPP , an dtha t entrainmen

t o f larva l fish an d macroinvertebrate s coul d b e virtuall y eliminate db

y us e o f 0. 5 m m(0.0 2 in ) intak

e screen mesh . Impingemen t surviva l fo r fish larvae , however , i s species-specific : unde r laborator y conditions , th e surviva

l rate s fo r larva e a t 4 8 h afte r a1 6 minut

e impingemen

t o n fine-mesh screen s ranged fro mles s tha n one percen

t fo r stripe dbas s t o 9 6 percen

t fo r bluegill an

d smallmout

h bas s (PG&

E 1988a , Appendix D ; Tomljanovich e

t al . 1978) . Th

e smalle r intak e screen mes

h would increas e impingemen t o f larva l an d juvenil e fish an

dinvertebrate s presently entraine d a t DCPP . The finer

mesh screen would conver t normally entraine dorganism s int o impinged organisms . I n 1980 , Tamp aElectri c Compan y (TECO ) performed apilo t scal e evaluatio n o f

afine-mesh Ristroph screen i

n th e intak e cana l t o it s Bi g Ben

d Station o

n Tamp aBay , Florid a(Taf

t et al . 1981 ; Brueggemeye

r et al . 1988) . TEC O agree d t o evaluat e th e potentia

l effectivenes s o f

finemesh screen s to reduc e losse s ofth e selecte d Representativ e Importan t Species : ba

y anchovy , black drum , silver

perch , spotte dseatrout , scale d sardine , tidewate r silverside , ston e crab , pin

k shrimp , America

n oyster , an

dblu e crab . The screen wa s ofth e No-well design , aduo-flo w screen desig n wit

h th e scree

n attache d directl y t o th e pump . Base d o n th e positiv e result s ofth e prototyp e testing , th e regulator y agencie s determine d tha

t Uni t 4 could b e constructe d wit h a once-through condense

r coolin g syste

mprovide d tha

t fine-mesh screen s wer

e incorporate d int

o th e intak e structure s o f

bot h Unit s 3 an

d 4 . Accordingly , six , 0. 5 m mmes h No-well screen s wer

e installe da t th e statio n an

dstudie s of

thei r biologica l effectivenes s wer

e conducte d i

n 198 5 (Brueggemeye

r et al . 1988) . Initia l an dlaten t mortalit y variedb y specie s an

d lif e stage . Collecte d invertebrate s ha d mortalit y rate s rangin g fro

m1 0 t o 3 5 percent . Engraulida e (primarily ba

y anchovy ) ha

d initia l mortalit y rate s rangin g fro

m4 2 t o 8 4 percen t an d laten t mortalit y rate s ranging fro

m3 2 to 3 5 percent . Ba

y anchovy , Atlanti c tomcod , an dAtlanti c silverside egg s showe d atota l mortalit y of 72. 4 percen

t (unadjuste dfo

r control) . Yolk-sa

c larva e o f mummichog , Atlanti c silverside , Atlanti c tomcod , whit e perch an dwinte r flounder mortalit y ranged from62 to 10

0 percen t wit h th e exceptio n of TENER A E9-055. 0 6-1 7 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.5 0 6. 0 Alternativ

e Intak e Technologie s winte r flounder , whic h ha

daprojecte d mortalit

y 1 1 t o 6 2 percent . Assumed mortalit y fo r post yolk-sac larva

e range dfro

m3 6 t o 10

0 percen t fo r al l specie s i

n thi s lif e stage . Th

e conclusio n o f th e stud y wa s tha t surviva l rate s wer e comparabl e to , an

di n som e case s exceeded , thos e obtaine d durin g th e prototyp e study . Ther e wa s n o significan

t differenc e i

n surviva l rate s between th e tw o sampl e locations .

Retrofittin g th e existin g DCP P through-flo w screen s wit h afine mesh would b e difficult du e t o th e increase dflow resistanc e increasin g th e potentia l fo r screen failur

e unde r high debri s loading . The siz e ofth e existin g DCP P circulatin g wate

r pump s an d th e intak e configuratio n woul d preclude th e retrofittin g o f No-wel l screens . No-wel l screen s would requir e anew , ope

n intak e structure , wit

h ne w circulatin g wate

r pumps . 

# B

I I I 1 1 A t Brayton Poin

t Statio n Unit

4 , biologica

l evaluation s wer

e conducte d t o determin e th e number , species , an dinitia l an dextende dsurviva

l offis h impinge d o

n th e modified intak

e screen s (Davi s e t al . 1988 ; LM S 1987) . Thes e fine-mesh, angle d screen s wer e installe d a

t ane w Unit 4 intak e t o diver t larger , motil e lif

e stage s an

dgently collec t

an d recove r early lif e stages . The lowes t

I surviva l wa s calculate dfo

r ba y anchovy an

d th e highes t

wa s fo r tautog . Initia

l an d extende d surviva l varie db y species ; however , acertai n group o f numerically dominan

t tax awa s classifie d * • b y th e author s a s "fragile " (primarily , ba y anchovy and Atlanti c silverside) . The fragil e group ha dacalculate dsurviva

l belo w 2 5 percen

t whil e a"hardy " group , dominate d b y winter flounde r andnorther

n pipefish , ha

dsurviva l value s greate

r tha n 6 5 percent .

A s par t o f a n evaluatio n o f

screenin g technologie s fo

r DCP P (PG& E 1996) , retrofittin g th e DCP P intak e wit h center flow screen s wit

h curve d basket s an

d afine mesh (2mm) wa s considere da s awa

y t o improv e debri s filtration. The curve d basket s ofth e centerflo w desig n wouldincreas e flow are aan doffse t th e flo w restrictio n cause d by th e fine r mesh . Thes e screen s coul db e equippe dwit

h fine r mesh screen s ( 1 mm

) tha t would potentially allo w screenin g o f larva l organisms . Thes e screen s coul d reduc e entrainment bu t would requir

e asite-specifi c evaluatio n t o determin e th e following parameters : • 1 . The survivabilit

y o f larva l organism s washed fromth e screens . 

# I I I I I fi I I

TENER A E9-055. 0 6-1 8 Fina l 316(b ) Demonstratio n Marc h 1,200 0 

# 1 1P.5 1 6. 0 Alternativ

e Intak e Technologie s



# E 2 . Th e potentia l increas e i

n impingemen

t due t o th e scree

n baske t shap e an d the flows associate dwit

h acenterflo w design . 3 . The abilit

y o f afine mesh scree

n to functio

n unde r hig h debri s loading condition s experience da

t DCPP . 4 . Th e abilit y ofth e refus e handlin g syste mt o proces s debri s wit

h minima l impact to screene dorganisms . The estimate dcos t

fo r thes e screen s i s estimate d $7,000,00 0 (PG&E 1996) . Thi s doe s not include an y modification s to th e debri s handlin g syste mo r potentia l modification s t o th e intak e structur e t o accommodat

e th e new screens . The tota l cos t woul d b e approximately $10,000,000 . Th e ne t presen t valu e o f thi s modificatio n i s (- ) $7,906,000 . Cente r flow screen s hav e amuc

h mor e complex distributio n o f

flow velocities , especially whe n installe di n ascreen well typ e intak

e lik e tha t use d a t DCPP . The entranc e are ato th e center flow scree n i s roughly 60 % a s wid e a s th e existin g travelin g screens , s o th e velocit y a t th e screen entranc e wouldb e about

67 % greater

(1. 3 t o 1. 7 ft/sec). The velocitie s a

t th e screen s ar

e about 70 % comparedt o th e current scree n approach velocity . I

n between , th e flow turn s 9 0 degrees , resultin g i n acomplicate dflo

w pattern . Thes e flow pattern s coul d increas e impingemen t o f juvenile s an

dadults . I n addition , th e basket s fo

r th e propose d center

flow scree

n ar e convex i n cros s section , which coul dincreas e retentio n o f an y fish impinged . Wit

h the mixed survivabilit

y datafo r larva l organism s impinge d o

n fine mesh screens , an

y biologica

l benefi t (or cos t i f there i s a n increas e i

n impingement

) would have to b e evaluate d prior to determinin g th e effectivenes s o f thi s alternative . 6.2.2. 4 Singl e Circulatin g Wate r Pum p Operatio n A reduction i

n the numbe

r o f operatin g CW

P woul d reduc e coolin g wate

r flows , proportionately reducin g th e numbe

r o f organism s entraine d a

t DCPP . The Diabl o Canyo

n Powe r Plan t i s designe d an

d operate d a s abase-loade d plan t wit h relativel y constan t electrica l generatio n fo

r extended period s o f

time . The operationa

l characteristic s o f Unit s 1 an

d2 limi t th e potentia

l effectivenes s of

singl e pum

p operatio n a s a

n alternativ e fo

r reducin g entrainmen

t an dimpingemen

t losses . Thi s would requir

e extended operatio n a

t 50 %

TENER A E9-055. 0 6-1 9 Fina l 316(b ) Demonstratio n Marc h 1,200 06. 0 Alternativ e Intak e Technologie s

power , whic

h lower s plan

t efficiency , reduce s revenue , an d degrade critica

l plan t equipment . A

n optio n to runnin g bot

h unit s a t 50 % power

level s would b e t o ru

n only one unit

a t 100 % power . Th e us e o f asingl e pum

p per unit a t DCP P wit h th e unit s operatin g a

t reduce d loa

d would als o present certai n technica

l operatin g difficulties . The motor s tha t operate th e CW

P ar e larg e (13,00 0 hp ) an

dunderg o substantia

l stres s and wea

r durin g th e startup . I

n order t o achiev e appropriat e performanc e ofth e unit

a t reduce d loa

d (e.g . a t 50 % powe

r o r less ) or t o increas e loa dabov e 50 % i

n respons e t o increase d demand , th e second circulatin g wate r pum p woul d b e neededfro mtim e t o time . Intermittent re-start s ofth e second pum p woul d greatl y increas e th e wear , reduc e pum

p moto r reliability , and increas e th e frequenc y o f maintenance . A seconddifficult

y arise s directl y fro

msingl e pum

p operations . Wit

h on e circulatin g wate

r pum p operating , there i s n o backup on-line . Thus , i f th e operatin g pum

p wer e t o fail , th e uni t woul dunderg o aforce

dshutdown . Ordinarily , wit h tw o circulatin g pump s running , failur e o f on e require s acurtailment

t o onl y 50 % power . Although there i s n o increase d ris k o f a n accident affecting th e healt

h an dsafet y ofth e publi c b

y operatin g wit

h on e circulatin g wate

r pump , plan

t operationa l transient s tha

t forc e auni t

shutdow n are regarde d a s anegativ e indicator b y th e Nuclea r Regulator y Commission . Becaus e ofth e los s o f

reliability , potentia

l equipmen

t degradation , an

d operationa

l inefficiency o f generatin g unit s tha

t woul daccompany operatin g eac h unit wit h one circulatin g wate

r pum p i n service , amor

e likely strateg y woul d b e t o tak e th e optio n o f

shuttin g dow

n one uni t an d bot h of it s pumps , i

f operatio n i

n thi s mode wa s expecte d t o b e fo r along period . Th e NP V of thi s optio n i s extremel y negative , based o n los s o f generation . Th

e los t revenu e an

d NP V fo r thi s optio n are , however , considere d proprietar y information . Thi s optio n ha s anegativ e contributio n t o th e environmen t a s aresult

ofth e nee d fo r th e IS O t o purchas e replacement

power fo r th e 1,10 0 M W reductio n i

n powe r production . It

i s assume d tha

t th e replacemen

t powe r wil l b e generate d b

y gas-fired powe

r plant s constraine d t o th e stat e o f

TENERA E9-055. 0 6-2 0 Fina l 316(b ) Demonstratio n Marc h 1,200 0 

# aP.5 3 6. 0 Alternativ

e Intak e Technologie s Californi aemissio n standards . Th e increase d amoun

t o f emission s fro

manatura

l gas-fired powe

r plan t generatin g 1,10

0 M W wouldb e a s follow s (tons/yr) : NO x C O C0 2 5,50 0 3,70 0 5,900,000 NO x an d C O ar e EP A criteri apollutant s regulate d unde r Titl e V ofth e Clea

n Ai r Act . C0 2 i s a "gree n house " ga s an

di s o f concer n fo r globa l warming . Additiona

l ai r toxic s suc h a s 1, 3 butadiene , acroliene , an

dformaldehyd

e ar e generate d i

n smalle r quantities , but

ca n represen t agreater ris k to th e populatio n an

d environment . Thes e calculation s ar e based upo

n emission s fro ma75 0 MW

e gas-firedpowe

r plan t wit h moderat e amount s o f

emission s controls . Emission s usedwer e 9 5 pp mNO x , 10

0 pp mCO , an d 9.6 % C0 2 . Mas s emission s wer e based upo

n operatio n o f

24 h/d , 36 5 d/yr . Becaus e ofth e los s o f

generatio n tha

t woul d accompan

y reduce d circulatin g wate

r pum p operation , singl e circulatin g wate r pum p operatio n or

singl e unit

operatio n i s no t

considere d a

n alternativ e tha

t coul dreduc e entrainment

a t DCP P i n acos t effective manner . 

### 6.2.2. 5 Variabl e Spee d Circulatin g Wate r Pump s Installatio n o f

variable-spee dmotor s o

n th e circulatin g wate

r pump s represent s one approach t o reducin g coolin g wate

r flows t o th e minimu

mleve l necessar y t o maintai n efficien

t operatio n of th e unit a t aspecifi c generatin g load . For thi s analysis , th e assumptio n i s tha t circulatin g wate

r flow wouldb e reducedto tha t require d fo

r 100 % powe

r operation . The basi s fo

r thi s i s tha t DCP P i s designe dt o operat

e a s abas e loaded plan

t a t 100 % powe

r an d doe s not chang e powe

r output o n adaily o r othe r schedule d basis . The pump s currently i

n us e ar e limited to no-flow or

full-flow operation . Variable-frequenc y drive s coul db e installe dto allo w thes e pump s to operat e a t lowe r speed s (and henc e lowe

r flows) , thereb y reducin g the number s of organism s entrained . Thus , th e circulatin g wate r flo w rat e couldb e adjustedto provide only the flow needed fo r condense r coolin g within operatin g limit s imposedb

y A T an dbac k pressur e operatin g criteria . Th

e magnitude ofth e resultant
TENER A E9-055. 0 6-2 1 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.5 4 6. 0 Alternativ e Intak e Technologie s reduction s i

n entrainmentlosse s woul d depen d o n th e reductio n in coolin g wate r flow an d th e abundanc e o f

organism s a

tth e time s whe n th e circulatin g wate r pump s wer e operate d a treduced flow rates . Th e intento f

variabl e spee d pump s i s t o reduce intake flo w withou timpactin g plan tpowe r operatio n (b y adjustin g circulatin g wate r flow t o tha tneede d t o jus tallo w operatio n withi n therma l limits ) then th e biologica l benefit s o f such a modificatio n woul d b e limite d an d base d o n th e amounto f

flow reduction . DCPP wa s no tdesigne d fo r larg e extreme s i n coolin g wate r ambien ttemperature , s o there i s littl e margin fo r reducin g circulatin g flow. Base d o n calculation s (V RFoster , PG&E , pers . comm . 1999) , th e maximum expecte d flow reductio n woul d b e 2-10 % whe n ocea n wate r temperature s ar e belo w th e averag e (14.4 ° C) . Thes e calculation s allowe d fo r a temperature differential ris e o f 11.1 ° C (t o allo w fo r margi n t o th e temperature limit ) an

d did notconside r th e impacto f condense r fouling . Furthe r decrease s i

n coolin g flow woul d caus e additional heatin g ofth e discharge d circulatin g water . Operatio n ofth e existin g circulatin g wate r pump s i s als o limite d b y th e pumps ' ability t o operat e a treduce d flow s withou tcavitating . Hydrauli c mode l tes tresults fo r th e existin g circulatin g wate r pump s reveale d tha tth e availabl e suctio n hea d i n th e presentinstallatio n restricts operatio n a treduce d speed s withou tsubjectin g th e pump s t o seriou s cavitation . There i s dat a fo r cavitatio n performanc e ofth e circulatin g wate r pump s a t80% , 90% , an

d 100 % o f

rate d speed . Th e dat

a demonstrate s tha

tth e pump s wil l b e mor e susceptibl e t o cavitatio n a s spee d i s reduced . Base d o n existin g data , iti s estimate d tha tth e greates tflow reductio n woul d b e o n th e orde r o f 2 0 t o 30 % (correspondin g t o a spee d reductio n o f 10% ; PG& E Drawin g DC663021-Sht . 29) . Th e present circulatin g wate r pump s ar e no tcapabl e o f

reliabl e servic e a

ta significantl y reduce d speed . Sinc e th e circulatin g wate r pump s ar e embedde d i

n th e concrete intake structure , replacemen tofth e circulatin g wate r pump s wit h pump s designe d fo r variabl e spee d operatio n woul d requir e th e constructio n o f

a ne w intak

e structur e simila r i

n siz e t o th e existin g structure . Variabl e spee d circulatin g wate r pump s ca n allo w substantia

l reduction s i

n case s wher e powe r plants loa d follo w (chang e powe r ove r th e cours e o f a da y o r week ) an

d wher e plants ar

e designe d fo r large variation s i

n hea tsink temperatures . Sinc e DCP P i s a bas e loade d plantdesigne d fo r a relativel y TENERA E9-055. 0 6-2 2 Fina l 316(b ) Demonstratio n Marc h 1,200 0PP"" " 6. 0 Alternativ e Intak e Technologie s
constan t hea t sin k temperature , ther

e i s litti e flow reduction tha t ca n b e expecte d (u

p t o 10%) . Thi s limit s th e biologica

l benefi t o f installin g variabl e speed drive s o n th e existin g pumps . Sinc e variabl e speeddrive s o f

asiz e needed ar

e not normally produced , the cost s fo r thi s modificatio n ar e difficul t t o estimate . Base

do n inpu t fro mone experience d vendor , th e ne t present valu e o f installin g variabl e frequency powe r unit s woul d b e approximately (- ) $7,652,000 . Du e t o th e low reductio n i

n flow an d relativel y hig

h (and uncertain ) cost s t o instal l thes e drives , th e minima

l reductio n i

n entrainmen

t i s no t considere d t o provide asubstantia] biologica l benefit . 6.2.2. 6 Refuelin g Outag e Schedulin g Diabl o Canyon Powe

r Plan t Unit s 1 an

d 2 ar e periodically removed fromservic e fo r refueling an dmaintenance . Th e unit

outage s occu

r a t a n interva l o f approximately 1 8 mo . Futur e outage s ar e expecte dt o las t

approximately 3 0 d . Th e seasona l planned reductio n alternativ e would involv e th e selectiv e schedulin g o f unit outage s to coincide wit

h th e pea k period s o f

abundanc e fo r key larva l tax ai n th e area . Ideally , refuelin g outage s would b e schedule d fo r specifi c time s o f th e yea r whe n densitie s o f

entraine d organism s ar

e greatest . Ove r th e pas t 1 5 year s th e majorit

y ofth e 1 8 refueling outage s have occurre d durin g th e month s o f March-Apri l ( 7 outages ) an dSeptember-October

( 5 to 8 outages) . Fall outage s hav e occurre d regularly durin g thes e months , bu t i n recent year s winte

r outage s starte d earlier , runnin g fro m February-March . Ofthe 1 4 target tax aincludin g subgroups , th e majorit y reproduc e durin g th e sprin g month s o f

March-Jun e (Tabl e 6-2) . Fe w o f thes e tax aar

e vulnerabl e a s larva

e durin g fall . A shif t i n outag e schedulin g to the sprin g would lesse n th e susceptibilit

y o f thes e larva

e t o entrainment . Having bot

h unit s refue

l eac h sprin g i s highly uneconomical . Extendin g eac h unit t o a2 4 m o cycl e wouldallo w fo

r sprin g outages , bu

t i s not possibl e wit

h current fue l design . Durin g th e norma

l operationa

l cycl e about

one-thir d ofth e fue

l i s consumed ove

r a n 18-2 1 m

o perio d befor

e refueling i s required . Thi s limit s th e possibilit y o f modifying outag e schedule s t o a shorte r duration . Withou

t the abilit y to lengthe

n fue l cycles , outage s could no t

b e schedule d onl

y

TENER A E9-055. 0 6-2 3 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.5 6 6. 0 Alternative Intak

e Technologie s durin g th e spring . Withoutthi s flexibility , shortenin g outag e schedule s t o occu r o n 1 2 mont h interval s woul d becom e inefficient . A secon d scenari o o f

reduce d operatio n coul d involve curtailments durin g period s o f greate r larva l density . Monthl y densitie s offis h larva e pea k durin g th e sprin g month s from Marc h throug h June , a s depicte d fo r 199 7 an d 199 8 i n (Figur e 6-6) . Durin g th e month s Marc h -Ma y approximatel y 55 % ofth e fish larva e fo r th e nin e month s endin g in Septembe r ar e a trisk t o entrainment . Thi s nin e mont h perio d wa s use d becaus e plankto n dat a afte r Septembe r 199 8 were analyze d onl y once-per-mont h wit h paired stud y gri d surveys . Durin g bot h years , larva

l densitie s pea k in May eac h yea r whe n 2 3 an d 3 1 percen to f

larvae wer e collected . Thes e strategie s woul d b e protectiv e o f

many specie s includin g KG B rockfis h (Sebastes spp . VJDe) , norther n anchovy , monkeyfac e eel , Pacifi c sardine , norther n lampfish , smoothhea d sculpin , whit e croaker , an d Californi a halibut . Sprin g tim e curtailments , however , woul d notb e protectiv e o f othe r fishe s includin g clini d kelpfish , blackey e goby , blu e rockfis h (Sebastes spp . V) , snubnos e sculpin , an d som e KG B rockfis h (Sebastes spp . VD) . A dua l unitcurtailmen tfo r a thre e mont h perio d eac h sprin g woul d hav e a significantl y negativ e financial impac to n PG&E . Th e NP V o f thi s optio n i s extremel y negative , base d o n los s o f generation . Th e los trevenu e an d NP V fo r thi s optio n are , however , considere d proprietar y information . Replacemen tpowe r obtaine d fro m gas-fire d facilitie s woul d generate aboutone hal f th e EP A criteri a pollutants an

d "gree n house " ga s emission s calculate d in Sectio n 6.2.2. 4 eac h yea r under thi s scenario . 

### 6.2. 3 Conclusio n A hierarchical evaluatio n wa s use d t o asses s whic h alternativ e intake technologie s wer e technicall y feasibl e an

d coul d reduc e impingemen tan d entrainmenta

tDCPP . A reassessmen tofth e 1985-8 6 316(b ) Demonstratio n Stud y (Tenera 1998a ) confirme d tha t estimate d impingemen ta tDCP P i s ver y lo w (0.3 2 t o 0.7 3 kg/d/unit) . Th e curren trepor tfound that , fo r an y typ e o f

modification , ver y littl e improvemen tca n b e mad e t o th e presen tDCPP TENERA E9-055. 0 6-2 4 Fina l 316(b ) Demonstratio n Marc h 1,200 06. 0 Alternativ e Intak e Technologie s intak e configuratio n to reduc e th e numbe r o f impinged fish, withou

t incurrin g substantia

l cost s relativ e to th e benefi

t achieved . Regardless , Sectio n 6- 2 o f thi s repor t studie d th e feasibilit

y o f thre e alternativ e technologies : a n increase d are aintake , angled scree n intake , an

d modified travelin g screen s wit

h enhance dfish handlin g equipment . Increasin g th e cross-sectiona l are aofth e intak

e structur e would decreas e th e wate

r flow rate . But , apparently health

y juvenil e an

d adult fish hav e bee

n observed living an

d swimming inside th e intak e structur e a t DCP P without being impinged . Also , implementing thi s altemativ e would requir e ver y substantia

l disruptio n ofth e intak

e cov e a s acofferda

mwould b e require d t o de

wate r th e cov e whil e dredgin g an d associate d modification s too k place . Th e angled screen intak

e desig n i s judge dt o have simila r cost s an d benefit s a s th e increased are aintake , wit h th e potentia

l fo r increas e fish recovery . The cos t o f implementin g either

th e increase d are aintak

e or th e angled scree

n intak e alternative s i s estimate dt o hav e ane

t presen t valu e o f approximately (-)$275,000,000 . Thi s equate s t o approximately $61,70 0 pe

r kilogra moffis h saved , assumin g the modification coul d completely eliminat e impingement . Due t o th e high cos t

a s wel l a s th e hig

h impact t o th e Intak

e Cove durin g constructio n an d negligibl e reductio n i

n impingement , thes e alternativ e intak e technologie s ar

e no t considere d cos t effectiv e fo

r DCPP . Applicabilit

y ofth e mos t

current intak e screen an

d fish conveyanc e technologie s wer e evaluated . Proposedmodification s t o th e existin g configuratio n includ e the addition o f

angled intak

e screens , watertigh

t fish collectio n buckets , low pressur e spra y .wash , agravit

y sluicewa y t o conve y fish bac k to th e ocean , an

d modification s t o th e screen s to allo w continuou s rotation . None ofth e organism s impingedo n th e screen s a

t DCP P ar e assumed to surviv e becaus e ofth e curren t debri s remova

l configuration . Installatio n o f agravit y sluicewa y an d low pressur

e spra y wash coul dreduc e th e mortalit y rat e o f impinged organisms . Although there i s insufficien t datato perfor

mathorough site-specifi c analysis , modified angle d travelin g screen s wit

h continuou s rotation , low pressur e spra y wash , an d watertigh

t fish

TENER A E9-055. 0 6-2 5 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.5 8 6. 0 Alternativ e Intak e Technologie s collectio n buckets hav e th e potential t o reduc e th e mortalit y o f impinge d organism s a

tDCPP . Implementatio n o f

thi s modificatio n ha s associate d capita l an d maintenanc e cost s resultin g i n a netpresen tvalu e (NPV ) o f (-)$11,000,000 . Th e cos to f savin g impinge d fish wit h thi s modification , assumin g 100 % survival , i s o n th e order o f $2,20 0 per k g o f

impinge d fish assumin g a 100 % reductio n i n impingement . Site-specifi c testin g o f thi s propose d modificatio n woul d b e required t o determin e th e actua l biologica l benefit . Becaus e impingemen ta

tDCP P i s alread y low , modificatio n ofth e curren ttravelin g screen s t o further reduc e impingemen ti s no tconsidere d cos teffectiv e fo r DCPP . For entrainment , five alternativ e technologie s hav e bee n identifie d a s technicall y feasibl e a t DCPP . Th e alternative s ar e closed-cycl e coolin g towers , fine mes h screens , single circulatin g wate r pump operation , variabl e spee d circulatin g wate r pumps , an d change s t o refuelin g outag e scheduling . Tw o type s o f

closed-cycl e coolin g tower s wer e evaluated . Bot h woul d reduce th e coolin g wate r requirement , possibl y a s muc h a s 80-95% , an

d resul ti n entrainmentreductions . However , installatio n an

d operatio n o f

closed-cycl e coolin g tower s hav e negativ e environmental impacts o n air qualit

y (sal tdrift) , increase d salinity ofth e coolin g wate r discharge , terrestria l impacts o f sal tdrift, an

d poo r aesthetic s a s a consequenc e o f hig h coolin g tower s an

d vapo r plumes . Additionally , closed-cycl e coolin g tower s hav e hig h capita l an d maintenanc e costs . Bot h units woul d b e de-rate d t o accommodat e th e ne w coolin g medium . Orde r o f magnitud e estimate d net presentvalue s (NPV ) range fro m (- ) $503,000,00 0 t o (- ) $1,072,000,000 , plu s cost s fo r design , licensing , demolitio n o f

existin g facilities , an

d environmental damag e t o th e land . Becaus e ofth e advers e terrestria

l environmental impacts an d high implementatio n cost s associate d wit h close cycl e coolin g towers , the y ar e no tconsidere d feasibl e a tDCP P Cente r flow screen s wit

h fine mes h ( 1 mm ) baskets coul d b e retrofitted t o th e existin g DCP P intake structur

e t o allo w screenin g o f

larvae . Studie s hav e show n wid e rangin g mortalit y rates fo r impinge d larvae , rangin g fro m 5 % t o nea

r 100% , dependin g o n species . A site-specifi c investigatio n woul d b e neede d t o determin e th e mortalit y for larva

l organism s a

tDCPP . I n addition , there i s a potential tha tth e cente r flow screens , wit h thei r highe r inle tvelocities , TENERA E9-055. 0 6-2 6 Fina l 316(b ) Demonstratio n Marc h 1,200 06. 0 Altemative Intak e Technologie s comple x flow pattern s an

dcurvedbasket s could increas e impingemen t o f juvenil e an

d adult fishes . Bot h survivabilit

y o f larva e an d an y change s t o impingemen

t would hav e t o b e evaluate d prio r t o assessin g abiologica

l benefi t fo r fine mesh basket s o

n center flo w screens . Th e net presen t valu e o f thi s modificatio n i s (- ) $7,906,000 , wit h a n uncertain benefit . Singl e circulatin g wate

r pum p operatio n wa s als o evaluate d a s ametho d to reduc e entrainment . Operatin g only one ofth e tw o CW P runnin g pe

r unit would reduc e the coolin g wate r requiremen

t b y about half , reducin g entrainmen

t b y th e sam e amount . Singl e circulatin g wate r pum p operatio n woul drequir

e tha t bot h unit s a t DCP P b e operate d a

t 50 % powe

r o r les s o r tha t one uni t b e shutdown . The los s o f

revenu e associate d wit

h singl e circulatin g wate

r pum p operatio n doe s no t

mak e thi s afeasibl e alternative . Variabl e spee ddrive s fo

r th e circulatin g wate

r pump s offe

r th e possibilit

y o f reducin g flow t o th e minimu mrequire dflowrate (optimizin g generatio n an d condensat

e depression ) neede d t o suppor t operatio n a

t aspecifi c level o f

plan t output . Sinc e DCP

P i s abas e loaded plant

operatin g a t 100 % powe

r mos t ofth e time , th e potentia

l flow reductio n i s limited t o 2 t o 10 % o f rate d flow, dependin g on ocea

n temperatures . Additiona

l flow reduction s are limite d b y th e capabilitie s o f th e pump s themselves , suc h tha t significan t flo w reduction s (eve

n wit h areductio n i

n powe r ar e limite dt o flow reductio n o f approximately 2 0 to 30%) . The cost s an d limite d potentia

l flow reductio n wit

h thi s alternativ e doe s no t

mak e thi s acos t

effectiv e alternative . The feasibilit

y o f schedulin g refueling outage s t o coincide wit h period s o f

hig h larva l densitie s o f certai n organism s wa s als o evaluated . Durin g refuelin g outages , th e amoun t o f coolin g wate

r require di s reduce dan

dstrategi c schedulin g coul d reduc e th e amoun t o f entrainment . I

t i s possibl e tha

t a t leas t som e ofth e refueling outage s could b e scheduled to coincide wit h period s o f hig h densit y o f certai n larva

l fish or invertebrat

e taxa . Man

y fishes produc e larva

e t o benefi t fro mthe increas e productivit

y associate d wit

h sprin g an

dsumme r months . Conductin g outage s durin g the sprin g coul dreduc e the impact o n nearshor e tax a7-10 % assuming tw o coolin g wate r pump s ar e out o f servic e fo r 3 0 d . Longe r curtailment s o f

coolin g wate

r pum p operation , exclusiv e o f

refueling outage s wer

e als o evaluated . Wate

r flow condition s woul

d b e severely reduce d fo

r one t o thre e month s unde

r thi s TENERA E9-055. 0 6-2 7 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.6 0 6. 0 Alternativ e Intak e Technologie s scenario . Som

e o r al l coolin g wate

r pump s woul d b e shut

dow n whe n amajorit

y ofth e fish larva e ar e present i n th e plankton . Th

e current dat aindicat

e alarg e percentag e ofth e larva l fishe s are vulnerabl e t o entrainment throug h th e sprin g month s March-June . Suspendin g pumpin g operations , excep t

fo r vita l AS W flows, fo

r thre e month s would protec t about hal f o f th e fish larva l densit y fromris k

o f entrainment . Th e cost s o f

thes e measure s are extreme and man y fishe s tha t reproduc e a

t other time s or hav e long-live d larva

l stage s would remain vulnerabl e t o entrainment

durin g th e 9-1 1 month s o f operation .

TENERA E9-055. 0 6-2 8 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.6 1 6. 0 Alternativ

e Intak e Technologie s Tabl e 6-1 . Listin g ofth e alternativ e technologie s evaluate d an d location ofth e evaluatio n i n thi s report . Categor y Intak e Technolog y Meets Criteri a Meets

Criteri a 2 Meet s Criteri a 3 Evaluate d i n note d Sectio n o r Appendi x Cooling Wate

r Syste m

Intak e Configuration

Behaviora l Barrier s

Physica l Barriers

Fis h Collection , Remova l an d Conveyanc e System s Maintenanc e an

d Operationa l Modification s Onc e Throug h Closed-cycl e cooling towe

r (saltwater ) Closed-cycl e cooling towe

r (fres h water ) Closed-cycle Cooling Pon

d o r Cana l Cooling syste

mcomponen

t modificatio

n Offshor e Intak e Locatio n / Velocit y Ca p Altemat e Onshor e Intak e Locatio n Shoreline Recessed IncreasedAreaIntak

e Structur e AngledScree

n Intak e Structur e Ligh t Soun d Bubble scree

n Velocit y gradien t (wate r je t or othe r turbulence) Electrica l barrie r Louvers Chemical s barriers Magneti c fiel

d (barrier ) Chai n an dcable barriers Vertica l traveling scree

n Dru mscree n Centerflow traveling scree

n Fin e Mes h Scree n Medi afilte r Stationar y scree n Horizonta l traveling scree

n InclinedPlan

e screen s Combination s o f

vertica l traveling scree

n modification s Gravit y sluicewa y Maintenanc e Dredgin

g Single circulating wate

r pum p operation Variable Spee

dCirculating Wate

r Pump s Continuou s scree

n rotation Refuelin g outag e schedulin

g N/

A • • •

• • N/ A • • • • • •

N/ A • • •

• • • • • • • N/

A • • •

N/ A

• •

N/ A

•

• •

• • • • N/

A • •

N/ A

• •

N/ A

•

• •

• • • • i n us e a t DCP P Section 6.2.2. 1 Section 6.2.2. 2 App . N App . L App . M App . M i n us e a t DCP P App . M Section 6.2.1. 1 Section 6.2.1. 2 App . M App . M App . M App . L App . L App . L App . L App . L App . L i n us e a t DCP P App . M App . M Sectio n 6.2.2. 3 App . L App . L App . L App . L Section 6.2.1. 3 Section s 6.2.1. 2 an

d 6.2.1. 3 App . M Section 6.2.2.4 . Sectio n 6.2.2. 5 Section 6.2.1. 3 Section 6.2.2. 6 N/A : No t applicabl e TENER A E9-055. 0 6-29 Fina l 316(b ) Demonstratio n Marc h 1.200 0P.6 2 6. 0 Alternativ

e Intak e Technologie s Tabl e 6-2 . Estimate dequivalent adults , month s o f

pea k density , an

d evaluatio n o f susceptibilit

y t o entrainment

fo r targe t cra b an d fish tax acollecte d i

n DCP P entrainment

an dstud y gri dplankto n samples . Commo n Nam e

Cancer crab s Brow n rock cra b Slende r cra b Pacific sardine Northemanchov

y Rockfishe s KG B comple x Blu e comple

x Painted greenlin g Sculpin s Whit e croake r Monkeyfac e prickleback Kelpfishe s Blackey e gob y Flatfishe s Sanddab s Califomi ahalibut Month s of Entrainmen

t Spring Winter-Sprin g Mar-Ma y Dec-Ma y Mar-Ju l Jan-Ma r all year , esp . Mar-Ma

y Apr-Ju l Dec-Ma r Mar-Ju n Jan ; Jun-Au g Mar-No v Jul-Sep t April-Ma y pea k densit y Stud y Grid May-Ju n May-Ju n Mar-Ma y Mar-Ma y Ma y Jan-Fe b May-Ju n Apr-Ju l Dec-Ma y Apr-Ma y Dec-Fe b July-Sep t July-Sep t Apr-May ; Ju

l Estimate

d EquivalentAdult

s (FH an d AEL) 9,100-23,40 0 895-5,46 0 3,170-8,46 0 16,100-120,00 0 497-1,12 0 18-35 3 n d

n d 5,110-15,00 0 n d
n d 10,300-75,40 0 92-2,37 0 n d Reduce

d Entrainmen

t Feb-Ma r & Sep-Oc t mayb e mayb e Ye s Ye s Ye s Ye s Ye s N o Ye s Ye s N o Ye s Ye s No

TENERA E9-055. 0 6-3 0 Fina l 316(b) Demonstratio n Marc h 1,200 0P.6 3 6. 0 Alternativ

e Intak e Technologie s Criteri a 1 I s the alternativ

e technolog

y available an

d prove n (i.e. , demonstrate

d operabilit

y an d reliability ) a

ta coolin g wate

r intak e havin g a siz e an

d environmen

tsimila r to ma tofth e DCP P site ? N O YE S Criteri a 2 (Generi c biologica l evaluation ) Coul d th e implementatio

n ofth e altemativ

e technology resul

ti n a reductio n i n th e los s o f aquati c organism

s fro m th e presen t operatin g conditions ? N O

YE S Criteri a 3 (Sit e specifi c evaluation ) i s implementatio

n ofth e altemative technolog y feasibl e a

tth e DCP P site , base

d o n site-specifi c considerations o f engineering , operations , an

d reliability ? N O

Y E S

__ J Se e Appendix L fo r descriptio

n ofth e technologies excluded b

y Criteri a 1 an d justification .

Se e Appendi x M fo

r descriptio

n ofth e technologies excluded b y Criteri a 2 an d justification . 

# I

Se e Appendix N fo

r description o f

th e technologie s excluded b

y Criteri a 3 an d justification . Se e applicable subsections o f Sectio n 6 fo

r feasibilit y evaluatio

n an d cos testimates .

Figur e 6-1 . Altemativ e intak e technologie s evaluatio n flow chart .

TENER A E9-055. 0 6-3 1 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.6 4 6. 0 Alternativ e Intak e Technologie s

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SECTIO N A' A Figure 6-3 . Sectiona

l vie w ofth e proposed expansio n ofth e intak e a t th e Diablo Canyo

n Powe r Plant .

TENER A E9-055. 0 6-3 3 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.6 6 6. 0 Alternative Intak

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th e Diabl o Canyo n Powe r Plan t site . o _ o C Q 5 ' (f tP.6 8 6. 0 Alternativ e Intake Technologie s

Figur e 6-6 . Monthl

y densit y of all fish larva

e collecte d i

n weekl y entrainmen

t survey s conducte d fro

mOc t 199 6 t o Se p 1998 .

TENER A E9-055. 0 6-3 6 Fina l 316(b ) Demonstratio n Marc h 1,200 07. 0 Discussio n 

## 7. 0 DISCUSSIO N
Th e purpos e o f

thi s stud y wa s t o asses s th e effect s ofth e Diabl o Canyon Powe r Plan t (DCPP ) coolin g wate

r intak e structur e o n population s o f

fishe s an d invertebrates . Effects fro

mth e plant' s coolin g wate

r intak e structur e ca n result fro mimpingemen

t o f organism s o

n the intak e travelin g screen s o r entrainmen

t int o th e plant' s coolin g wate

r intak e structure . Thi s stud

y focuse d o n entrainmen

t effects , becaus e a

n evaluatio n b

y th e Regiona

l Board' s Entrainmen

t Technica l Workgrou p (ETWG) detennine dtha

t impingemen

t effect s wer

e no t significan t (Tenera1998b) . Althoug h man y marine organism s have planktoni c forms tha t could b e entraine d b

y th e powe

r plant , the ETW

G focuse do n th e larva e of fishes , crabs , an

d se aurchins . Althoug

h hundred s of differen t tax awer e entrained , th e ETW

G chos e 1 6 targe t

tax afo r thi s assessmen

t tha t included 14 fishe s an dtw o specie s o f

crabs . Thei

r decisio n wa s based o

n criteri atha

t included th e abundanc e o f ataxon , th e availabilit

y o f suitabl e life-histor

y information t o mee

t assessmen

t mode l requirements , an

dcriteri aoutline di

n USEP A Draf t Guideline s (USEP

A 1977 ) an

d modifie d b y th e ETW G (Tenera1997b) . Th

e ETW G determine d tha

t severa l assessmen

t approache s wouldb e appliedto th e datafo

r eac h taxon wher

e possible . Wher

e we wer e abl e to complet

e tw o or mor e approaches , we comparedresult s to provid e abasi s fo

r determinin g th e accurac y o f ou r assessmen t fo r a n individua

l taxon . 

## 7. 1 Assessmen t Approache s Three assessmen

t approache s developed b

y PG&E , it s consultants , an d othe r member s ofth e ETW G wer e use dt o estimat

e entrainmen

t effects a t DCPP . Estimate s o f

entrainmen

t loss , an d the demographi c dat areporte di n th e scientifi c literature , wer e use d t o parameteriz e tw o demographi c approache s fo

r estimatin g entrainmen

t effects : Fecundit

y Hindcastin g (FH) an

d Adul t Equivalen

t Los s (AEL). Thes e method s ar e simila r except tha t FH use s the numbe

r o f larva e entraine d to hindcas t th e numbe

r o f eggs , an dthe numbe

r o f egg s i s the

n use d to estimat

e the numbe

r o f femal e adult s tha

t wouldhave produced them . Th e AEL metho d forecast s th e numbe r o f adult s tha t woul dhav e survive dfro

mth e estimate d numbe

r of entraine d larvae , a s i

f they ha d survive d entrainment , usin g knowledg e of natura l mortalit y rates . I t ha s bee n assumed throughout

thi s TENER A E9-055. 0 7- 1 Fina l 316(b ) Demonstratio n Marc h 1,200 07. 0 Discussio n

stud y tha t 100 % mortalit

y occur s fo

r al l entraine d larvae . A thir

d method , th e Empirica

l Transpor t Mode l (ETM), estimate s a

n averag e annua

l larva l mortalit y du e to entrainment

P ht pe r individua l taxon , usin g estimate s o f

proportiona

l entrainment

(PE) tha t compar e th e numbe

r o f larva e entraine di

n one da y t o th e numbe

r o f availabl e larva

e i n th e sourc e wate

r body . Larva

l mortalit y i s calculate dafte

r PE i s weighte d b

y th e estimate d fraction ofth e tota l populatio n affectedan

dcompounde dby th e time larva e ar e susceptibl e t o entrainment . Th e thre e approache s combin e demographi c information wit h environmenta

l settin g to mode

l entrainmen

t effect s an dthen , wher

e possible , compare s thes e result s t o corollar y data . The corollar y datausedi

n thi s repor

t include d fisherie s information , datafro mIntak e Cov e plankto n tows , an dsubtida l observation s o f

juvenil e an

d adult fishes . Th e integratio n o f

growth , reproduction , andmortalit

y parameter s i

n th e thre e model s are used i n obtainin g estimate s o f adul t losse s an dentrainment

mortality . Thes e estimate s help u s better understan d populatio n measure s suc

h a s length-frequenc y distribution s an d indice s o f

year-clas s strength . Muc

h ofth e effor t i n compilin g thes e model s i s simila r to th e proces s undertaken b y fisher y scientist s to conduc t stoc k assessment s use

dto gaug e th e healt

h o f fishe d populations . Stoc k assessment s ar

e tool s fisher

y scientist s us e to determin e th e healt h o f afis h population . Thes e assessment s combin e availabl e biologica l an d demographi c datawit

h information o

n fishing effor

t an dlanding s to asses s trend s offis h abundance . Thes e trend s ca n b e assesse d fro

m source s suc

h a s long runnin g observationa l dataset s (e.g. , subtida

l fis h observations , Tener

a 1997c) , annua

l fisher y catch statistics , an

d dat ao n fishing effort . Fisher

y scientist s divide the amoun t o f catch b y th e amoun

t o f time spen t fishing t o creat e a n inde x o f abundanc e calle d 'catch-per-unit-effort. ' Catch dat aalone ar

e a n imperfec t

estimato r o f abundanc e sinc e they ar

e a n indirec t measur e o f th e availabl e fis

h populatio n andma

y als o reflect

biase s towar

d larger , mor

e easil y harvested , or mor e valuabl e fishes . Therefore , fisher y scientist s mus t

combin e biologica

l dat adescribin g th e populatio n unde

r stud y wit h catch datato understand the trend s the y observe . Th e type s o f biologica l datatha t ar e usefu l to hav e are : the ag e structur e ofth e population , ag e a

t firs t entr y int o th e fisher

y (recruitment) , ag e a

t firs t reproduction , estimate s o f longevity , an

d perhap s mos t

TENER A E9-055. 0 7- 2 Fina l 316(b ) Demonstratio n Marc h 1.200 07. 0 Discussio n

importantly , estimate s o f

tota l mortality . Tota

l mortalit y i s th e combinatio n of

mortalit y du e to bot h natura l an danthropogeni c cause s lik

e fishing . Understanding th e effects o f entrainmen

t o n larva l fis h population s require s simila r step s a s thos e take

n to asses s th e healt

h o f adul t populations . Simila r t o th e proces s fisher

y scientist s us e fo

r assessin g fis

h populations , the assessmen t model s fo r DCP P require dsevera

l decision s regardin g th e assumptions , leve l o f complexity , datainputs , an dapplication . Issue s considere d included th e following :

• compensation ;

• entraine deggs ;

• calculatio n o f

larva l duration ; an

d

• applicatio n o f

mode l result s i n a n assessmen

t o f habita t damage . I n addition , al l assessment s wer e based o n th e assumptio n o f

100 % mortalit

y o f all entraine d organisms . 

### 7.1. 1 Compensatio n Sail ae t al . (1987 ) defin

e compensatio n a s "th e abilit y o f afis h populatio n t o offset , i

n whol e or part , reductio n i

n number s cause db

y impact s fro

mnatura l and/or man-induce d stresses , whic h include s fishing. " Postulate dcompensator y mechanism s include growth , competition , predation , cannibalism , siz e a

t maturity , fecundity , disease , an d reproduction . Ricke

r (1975 ) report s tha

t compensator

y mortality , a s afunctio

n o f populatio n size , reduce s th e intrinsi c rat e of population increase . Nisbet

et al . (1996 ) sa

y tha t compensatio n fail s t

o preven t decline s i n adul t stock s i n respons e t o addedmortalit

y o f larva e by powe r plants , except

whe n compensatio n occur s i

n th e lat e immatur e stages , afte

r entrainmen

t bu t before : maturation . Density-dependenc e i s no t confinedto actin g through mortality ; growt h an d fecundit y ma y als o b e density-dependent . Therefore , th e processe s tha t regulat e population s ar

e complex . Som

e entrainmen

t studie s hav e assume dtha

t compensation i s no

t actin g betwee

n entrainmen

t an d the time whe

n adult recruitmen

t woul dhave take

n place , an

d further , tha

t thi s specific assumptio n resulte d i n conservativ e estimate s of

projected adult

losse s (Sail ae

t al . 1997) . Others , suc

h a s Parke r an d DeMartin i (1989) , didno

t includ e compensator

y mortalit y i n estimate s o f

equivalen t adult losse s I TENER A E9-055. 0 7- 3 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.7 2 7. 0 Discussio n becaus e o f alac k o f consensu s o

n ho w t o include i

t i n th e model s and , mor

e importantly , uncertaint y about ho w compensatio n would operate o n th e population s unde

r study . The uncertaint y arise s becaus e th e effect

o f compensatio n o

n th e ultimat

e numbe r o f adult s i s directl y relate dto th e vita

l processe s (fecundity , somati c growth , mortality ) an d affected lif

e stages . I n particular , Nisbet

e t al . (1996 ) showed tha

t neglectin g compensatio n doe s not alway s lea

d to conservativ e long-ter

mestimate s o f

equivalent

adult losses . Density-dependen

t recruitment

___ . . . ._ . .,„ . , . L .I. M I I rr-rrr-*——- " min".i.iji u " ' " " mn . nw.wia.ni . . j miirw i inju r compensatio n i s als o har

dto distinguis h fro

mcompetin g climati c effects . Confoundin g o f environmenta

l anddensity-dependent

effect s i s amajo

r problemtha

t ca n resul t i n spuriou s environmenta

l effect s bein g mistaken a s density-dependent effects(Clar

k e t al . 1999) . The samplin g pla

n an dmodelin g evaluatio n fo

r thes e entrainment

studie s a t DCP P (Tener a1998a

) considere dtha

t populatio n regulatio n coul d include bot h positiv e an

d negativ e compensator

y mechanisms . W

e als o conclude dtha

t i t woul d b e beyon

dth e scop e ofth e current

stud y to include populatio n regulatio n i

n th e model s used t o predic t adult losses . Compensatio n (density-dependence ) i s als o a n importan

t componen

t ofth e fishery managemen t concep t o f surplu s productio n (Ricke r 1975 ; Figure 7-1) . Thi s theoretica l relationshi p describe s th e relationshi p between adult abundanc e an

d th e numbe

r o f progen y they produce . I

n thi s construct , there i s a

n equilibriumpopulatio n leve l a t whic h ther e ar e jus t sufficien t adult s i n th e populatio n to replac e themselves . Productio n abov e an d beyon d thi s leve l i s terme d "surplu s production " tha

t ca n b e harveste dwithout

depletin g th e population . Entrainmen t mortalit y i s analogou s t o harvestin g mortality , excep t tha t i t remove s younge

r animal s fro

mth e population . I

t appear s tha

t fo r man y ofth e target

tax aexamine d a

t DCPP , th e additiona

l mortalit y o n early lif e stage s addedb

y entrainmen

t i n th e coolin g wate

r intak e syste mcould b e attribute d to surplu s productio n sinc e there ar

e no concurren

t decrease s i

n adult o r larva l abundanc e measure d a

t othe r locations . 

### 7.1. 2 Egg s Planktoni c egg s ar

e entraine dalon g wit

h larva e a t DCPP . Earl

y i n the proces s o f

developin g th e presen t study , th e ETW

G decide dno

t t o enumerat

e fis h egg s i n the plankto n sample s collected . Th e reason s fo

r thi s decisio n wer

e that , whil e there ar

e som e description s o f

marin e fis h eggs , TENER A E9-055. 0 7- 4 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.7 3 7. 0 Discussio n their classificatio n i s bot

h difficul t an d time consuming , an

d ultimately , th e initia

l lis t o f possibl e target tax adidno t

include man

y fishe s wit

h pelagi c egg s tha

t would b e subject

t o entrainment . Eg g losse s hav e bee

n quantifiedi

n othe r 316(b ) entrainmen

t studie s (e.g. , Murdoc

h et al . 1989 ; Baile y e t al . 1998 ; Cherr

y an dCurri e 1998 ; Jacobson et al . 1998 ; Richku s 1998) . Lacking th e eg g entrainmen

t data , on e migh

t assum e tha t th e number s o f

adul t equivalen t losse s resultin g fro

m eg g entrainmen

t woul db e equa l to thos e estimate d fro

mlarvae . However , th e actua l situatio n ma y b e mor e complex ; fo

r example , there ar

e difference s i

n dispersio n pattern s betwee n egg s an d larvae , larva

l behavior ma y affec t entrainment , etc . (Laske

r 1981) . Population s ofth e five target tax awit h pelagi c egg s (Pacifi c sardine , norther n anchovy , whit

e croaker , sanddabs , an

dCaliforni ahalibut

) ar e not adversely affected b

y the DCP P intak e indicate db

y generally low t o moderat e estimate s o f

annua l entrainmen

t mortalit y (P SI ), FH , or AEL. Furthermore , thes e tax aar e protecte d agains t

localize d effects b

y having widesprea

d population s or

spawning center s distan

t fro mDCPP . I

n th e cas e o f

Californi ahalibut , wit

h a relativel y high P KI

, bu t low approximate d FH, ver y fe w individual s ar

e entraine d a

t DCP P s o ther e i s no advers e impact

o n their population . Al

l othe r target tax aeithe r broo d their

egg s attache dto thei r

bodie s (Cancer

spp . crabs) , extrude liv e larva e (rockfishes) , or

have demersa

l adhesiv e egg s (greenlings , sculpins , pricklebacks , clini d kelpfishes , an d gobies) . Therefore , eg g losse s ar e not assumedt o b e a

n importan

t facto r i n estimatin g entrainmen

t effects . 

### 7.1. 3 Larva l Duratio n Larva l length s a t entrainmen

t wer e use d to estimat

e ag e a t entrainmen

t fro mgrowt h rate s reporte do r derive dfro

mcurren t scientifi c literature . Thi s method ha s man y assumption s wit

h implication s fo

r th e result s ofth e presen

t study . Primar

y among thes e i s the assumptio n tha t th e poin t estimate s reporte di

n th e literature , ofte

n fro marea s geographically removed fro mth e centra l coas t o f California , ar

e representativ e of

growt h rate s fo r lan'a e i n the are aaround DCPP . Dividing all larva

l length s b y the sam e growt h rat e to obtain estimate d age s assume s tha t growt h i s constan t ove r th e duration s estimated . Variatio n i n growt h rates , mor

e probabl e fo

r large r individuals , couldlea

dto miscalculation s of

larva l age . Examination o f

length-frequency histogram s fo

r th e variou s tax atreate d i

n thi s stud y an d comparison o f

thes e wit h reporte d hatch TENERA E9-055. 0 7- 5 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.7 4 7. 0 Discussio n length s lead s to th e conclusio n tha t there i s muc

h wide r variatio n i

n hatch length s o f

thes e fishe s tha n i s presently reflecte di

n th e literature . Thi s follow s fro mth e observatio n tha

t man y ofth e larva e collecte dan

dmeasure di

n thi s stud y wer e smalle r tha n th e reporte d hatch lengths . I n man y cases , th e averag e length s o f larva e entraine d wer

e les s tha n reporte d hatch lengths . Thi s ma y b e du e i n par t to larva l shrinkag e resultin g fro

mpreservatio n (Theilacker 1980) . The approximately

norma l distribution s observe dfo

r ver y small lengt

h larva e could als o resul t

fro mnatura l random variatio n i n hatch length s an

dcouldexplain th e length s bein g les s tha n thos e reporte d fo

r hatchin g (Matares e et

al . 1989 ; Mose

r 1996) . If th e actua l larva l age s a t entrainment

wer e younge r tha n ou r estimate s th e area s containin g th e affected populatio n would b e smalle r tha n -^PfflMMMttmn

W ~.Jk" thos e estimate dusin g th e present methods . If

th e affected population s are actuall y smaller tha n thos e use di n th e ETM, then P M coul d b e underestimate d 

### 7.1. 4 Applicatio n t o Habitat The conservatio n offis h habita t ha s bee n recognize d b

y scientist s an

d manager s a s a

n essentia l issu e i n fisheries managemen

t a s aresult

o f measure s included i

n th e reauthorizatio n ofth e Magnuson-Steven s Fisher

y Conservatio n an

d Managemen

t Act (Benaka1999) . Thes e measure s emphasiz e th e needt o preserv e essentia l fish habita

t an d integrat e ecosystem-base d concept s int o fisherie s management . The abilit y to quantif

y th e succes s o f

managemen

t practice s fo

r preservin g essentia l habita t i s potentiall y easier

tha n quantifying fish population s tha t ar e mobil e an

d difficul t to sample . I

t i s recognize dtha

t effective managemen

t o f essentia l fish habita

t require s knowledg e of

species-specifi c habita

t requirements , description s ofth e physica l environmen

t an d availabl e habitats , an

destimate s offis h population s i n th e differen

t habitat s (Cobb e

t al . 1999) . The typ e o f

information require dt o conver t P A ; int o somethin g mor

e tangibl e tha

t i s -, representativ e ofth e effectiv e are aor habita t affecte d i s not availabl e fo

r ou r nearshor e targe t Lf v ' , taxa . I

n addition , whil e los s o f

habita t ma y b e logically converte d int

o fish populatio n losses , th e fA • ' , . ") • ,*.-<•' ' conversio n o f entrainment

losse s int o habita t i s les s reasonabl e becaus e there i s no specifi c ".'•'"' " , rr. r ' y <y shorelin e are aassociate dwith , o r degrade d by , entrainment . The conversio n o f entrainmen

t losse s int o habita t losse s als o ignore s th e fac t tha t entrainmen

t onl y affect s one lif

e stage , an d recruitment

an dmigratio n fro

munaffected portion s ofth e populatio n will continu e t o fill TENER A E9-055. 0 7- 6 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.7 5 7. 0 Discussio n 

# I I I I I I availabl e habita t niches . Continuin g long-ter mshift s i n oceanographi c condition s affecting fish habita t qualit y an dproductivit

y als o confound s attempt s to conver t entrainmen

t losse s int o habitat . 

## 7. 2 Assessmen t of Entrainmen t Effect s The following criteri awer

e develope d b

y PG&E , it s consultants , an d other member s ofth e ETW G fo r evaluatin g advers e environmenta l impact s (AEI ) a

t DCPP . Thes e criteri aar

e specifi c t o th e marine environmen

t aroundDiabl o Canyon , i

n mos t case s ar e uniqu e t o marine aquati c organisms , an

dar e directl y applicabl e t o th e presen t 316(b ) entrainment

study :

• environmenta

l trend s (climatologica

l o r oceanographic) ;

• abundanc e trend s (e.g. , Intak e Cov e plankton tows , subtida l fish observations , fisher y catch data) ;

• lif e histor y strategie s (e.g. , longevit

y an d fecundity) ;

• populatio n distribution ; an d

• magnitude o f

effects . Thes e criteri aar

e discusse di

n th e section s tha

t follow . The criteri awer

e considere d o

n ataxon specifi c basi s whe

n tryin g t o determin e th e exten t o f entrainmen

t effect s o n the loca l environmen

t an do n th e populatio n a

t large . Thi s provide s abasi s fo r ou r conclusion s i

n Section 13 fo

r assessin g AE

I using USEP

A guideline s to determine the "relative biological value ofthe source water body zone of

influence for selected species and

determining the potential for damage by the intake structure "

(USEP A 1977) . The USEP

A (1977 ) als o state d tha

t th e biologica

l valu e o f a give n are ato aparticula

r specie s b e base

d o n "principal

spawning (breeding) ground, migratory pathways, nursery or

feeding areas, numbers of individuals present, and

other functions critical during the life history." 

### 7.2. 1 Environmenta l Trend s Change s i n recruitmen

t an dadult abundanc e appea

r to b e periodically accentuate d b y E l Nin o event s observedi

n the DCP P receivin g wate

r monitoring progra

m(RWMP) long-ter

msubtida l juvenil e an

dadul t fish observatio n data . A declin e i n abundanc e i

n th e subtida

l fish observatio n dat afollowing th e 1991-199 3 E l Nin o even

t i s commo n t o man y ofth e target

taxa . I n 1992 — TENER A E9-055. 0 7- 7 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.7 6 7. 0 Discussio n 1993 , nearl y al l tax aexperience dashar p declin e i n abundanc e followed b

y relativel y constant bu t loweredabundanc e t o th e present time . Th e extende dE

l Nin o even

t between 199 1 an

d 199 3 ha dimportan

t implication s fo

r man y ofth e fish tax afoun

d her e (Yoklavich et

al . 1996) . War

m wate r event s ca n hav e ver y larg e detrimenta

l effect s o n rockfish year-clas s strengt h sinc e thes e ar e typicall y specie s wit

h coldwate

r affinitie s (Karpo v et

al . 1995 ; Lenar

z et al . 1995 ; Ralston an dHowar d1995 ; Leaet

al . 1999 ; Lov e et

al . 1999) . Abnormally hig

h wate r temperature s an

d suppressio n o f

annua l upwellin g alon g th e Californi acoas t hav e bee n linked t o large-scal e reduction s i

n th e primar

y prey o f juvenil e and adul t

rockfishe s (Mulli n an

d Convers i 1989) . Reduction s i

n foodsource s ca

n negativel y affect

th e somati c an

d reproductiv e conditio n o f thes e lif e stage s (Lenarz an

dWylli e Echeverri a1986 ; VenTresc aet al . 1995) . Anothe r stron g E l Nin o even

t occurre d alon g th e centra

l Californi acoas t

an d easter n Pacifi c Coas t durin g th e fall , winter , andsprin g season s o f 1997-9 8 (Lyn

n e t al . 1998) . Thi s ma

y explai n th e difference s i

n entrainment

estimate s betwee

n th e year s 1996-9 7 an

d 1997-9 8 fo

r som e ofth e tax a(Tabl e 7-1) . Change s i n distributio n an

d dispersa l pattern s o f

pelagi c larva

e are expecte d durin g anomalou s war

moceanographi c event s (Bailey an d Incz e 1985 ; Brodeu

r e t al . 1985) . Fo

r example , estimate s o f

entrainment , FH

an d AEL fo r bot h Pacific sardin e an

d norther n anchovy increase dmarkedly betwee n th e first an d second yea

r ofth e study . Th

e spawnin g biomas s fo

r bot h o f thes e specie s i s typicall y centere d sout h o f Poin t Conception (Har

t 1973 ; Butle

r e t al . 1987 : PFMC 1998 ; Hill et

al . i n press) , and i

t wa s likely displace d northwar d wit h th e north

flowing E l Nin o current s presen

t i n th e second year . Whit

e croake r FH an d AEL als o appeare d to increas e slightly , whic

h ma y als o b e du e t o additiona

l transpor t northwar d durin g th e E

l Nin o year . Other

specie s appeare dt o b e somewha t les s affected b

y E l Nino-relate d transpor

t sinc e FH an dAEL remaine drelatively constan t or decrease d onl

y slightly betwee

n year s (e.g. , KG

B rockfishes , blu e rockfis h complex , blackey e goby , an d sanddabs) . Thes e fishe s probably hav e mor e localize dspawnin g population s tha t wer e les s affecte

d b y th e E l Nin o event . Coasta l marin e ecosystem s i

n th e Souther

n Californi aBigh

t have experience d reduce d productivit

y associate dwit

h aclimate regim

e shif t toward s warme

r wate r condition s tha

t bega n durin g th e 1976-7 7 E

l Nin o (Holbrook

et al . 1997) . Thes e change s hav e le d t o larg e impact s o

n

TENERA E9-055. 0 7- 8 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.7 7 7. 0 Discussio n populatio n abundance s an

dtrophi c structur

e i n nearshor e benthi c communitie s withi n th e Bight . I n general , they showedtha

t th e diversit

y an d abundanc e o f

fishe s wit h mor e norther n biogeographi c distribution s have decline d i n th e Souther

n Californi aBigh

t sinc e th e adven

t o f thi s warme

r wate r regime . Furthermore , thes e assemblage s have show n ashif t i n th e dominan

t specie s awa

y fro mmor e norther n distribute d tax aan

d towar d mor e southerl y distribute d specie s tha t ar e presumably mor

e toleran t o f war mwater . Simila

r trend s wer

e als o observe d furthe

r nort h a t Sant aCru z Islandwher

e population s o f

surfperches , th e standin g stoc k o f their crustacea n prey , an dth e biomas s o f

understor y macroalga

e all decline d b

y ca . 80% . Holbroo

k et al . (1997 ) hypothesiz e tha

t fish abundanc e decline d a s aresult o f declinin g recruitmen

t tha t becam e insufficien t t o compensat

e fo r losse s o f olde r ag e classes . Thi s ca

n b e terme d "recruitment overfishing " define

db y Gulland(1983 ) a s limitin g th e amoun t o f larva e apopulatio n produce s b y takin g primarily older , mor e fecun d adult s an

d leavin g young , les s fecun d individuals . Thes e recruitmen

t level s fel l mor e tha n one orde r o f magnitude ove

r tw o decade s an

d wer e correlate d among year s wit

h broa dindicator s o f

Bight-wide productivit

y ofth e coasta

l marine ecosystem ; namel y th e biomas s o f

zooplankto n i

n th e Californi aCurren

t (Holbrook

et al . 1997) . 

### 7.2. 2 Abundanc e Trend s Dat acollecte dfo

r thi s 316(b ) stud

y ca n b e compared wit

h othe r corollar y an d long-ter mdataset s t o giv e broade

r tempora l contex t t o the 2- 3 yea

r stud y a t DCPP . Severa

l ofth e target

tax aar e nearshor e specie s tha

t ar e no t take n b y commercia

l or recreationa

l fisheries . Fo

r thes e taxa , data fro mlong-ter mstudie s a

t DCP P o n larval , juvenile , an

d adult fish abundanc e wer

e use d to examine change s i

n abundanc e tha

t ma y b e correlate d wit

h entrainmen

t effects . Decline s i n adult abundance s of

clini d kelpfishe s an

d snubnos e sculpin overth e las t severa l year s wer e detecte di

n DCP P subtida l fis h observatio n datai

n th e contro l are a(Tenera1997c) . Thi s decreas e i n adult abundanc e als o appear s to b e correlate d wit h adecline i

n their larva l abundanc e apparen t fro mIntak e Cove plankton tows . Thes e tax aals o ha d som e ofth e highes t

estimate s o f tota l annua l entrainment

among th e target

taxa . Smoothhea

d sculpin , whil e havin g relativel y hig h tota l annua l entrainment , didnot

sho w simila r decline s i n adul t o r larva l abundance . Thes e an

d

TENER A E9-055. 0 7- 9 Fina l 316(b ) Demonstratio n Marc h 1.200 0P.7 8 7. 0 Discussio n other nearshor e tax aappea

r t o demonstrat

e simila r variatio n t o tha

t observe d i

n previou s year s fro msubtida l fish observation s an

dIntak e Cov e plankto n tows . Intak e Cov e plankto n tow s wer

e collecte d a

t DCP P startin g i

n 1990 . Although samplin g occurre d throughou t

th e year , larva

l densit y estimate s wer

e calculate d fro

monly th e seve

n month s ofth e yea r whe n larva l fishes wer

e mos t abundan t (December-June) . Thes e datawer e use d t o adjus t entrainment

estimate s t o along-ter

maverag e densit

y i n th e Cove . Thi s procedur

e coul d introduc e abia s i n th e adjustedestimate fo

r fishe s whos e larva

e ar e onl y abundan

t i n th e wate r colum n durin g th e other

five month s ofth e yea

r (e.g. , sanddabs) , and fo

r som e tax aa n adjustmen

t wa s no t calculated . Tw o taxa , blackey e gob y an d clini d kelpfishes , wer

e ver y abundan t durin g th e five month s o f

Intak e Cov e sample s tha

t wer e no t processed . They wer

e adjusted t o th e long-ter

m averag e becaus e larva

e fo r thes e tax awer

e presen t i n th e sorte d samples . Trend s i n adul t abundanc e ofth e commercially importan t blu e rockfis h comple x an

d cabezo n als o showeddecline s i

n ou r long-ter mfish observatio n data . The earl y an d mid-1990' s sa

w th e adven t o f live-fis h fishin g alon g th e centra l coas t o f Californi a(Bloese

r 1999 ) tha t could b e relate d to thes e declines . Live-fis h fishing ha s bee n identified a s acaus e o f

"growt h overfishing " (Gullan d1983 ) an

dshar p decline s i

n adult abundanc e (Star

r et al . 1998) . Landing s a

t Morr o Ba y are aport s do not

indicat e long-ter mdecline s i

n th e catch o f

adult cabezon , although a26 % reductio n i

n landing s i

n 199 9 compared t o 199 8 suggest s tha t th e 'live-fish ' fisher

y cannot b e sustaine da

t hig h exploitatio n rate s fo

r long . Fisher

y harves t datad o not

indicat e an y long-ter m declinin g trend s fo

r other commercially o

r recreationall y importan

t specie s als o entraine d a

t DCPP . An y potentia l effect s o f

powe r plan t larva l entrainment

o n catche s o f

harveste d specie s ma y b e maskedb

y change s i

n exploitatio n rate s an

d th e lac k o f credibl e catch-per-un it-effor t data neededt o examine long-ter mtrends . Clearly , othe

r longer-ter mdecline s associate d wit

h aclimate regim e shif t tha t bega n i n th e lat e 1970' s (Holbrook

e t al . 1997 ) mus t

als o b e considered . 

### 7.2. 3 Lif e Histor

y Strategie s Lif e histor y strategie s playe da

n importan

t rol e i n th e thre e assessmen

t approache s w

e use d t o asses s th e magnitude o f

entrainment

effects . Fecundit

y hindcastin g (FH) estimate s of adult losse s relie do n th e numbe

r o f egg s an dfis h or cra b larva e produced durin g thei r

life . Pelagi c tax alik

e TENER A E9-055. 0 7-1 0 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.7 9 

# I I 7. 0 Discussio n

norther n anchov y typicall y produc e numerou s egg s tha t hatc h relativel y under-develope d larvae . Thi s strateg y hedge s agains t hig h eg g an d larva l mortalitie s b

y reducin g th e amoun

t of energ y placedint o an y one progen

y an dassure s tha

t a t leas t afe w will surviv e to adulthood . Anothe r commo n strateg y foun

damon g th e target

fish tax ai s producin g relativel y fewer , demersal , adhesiv e eggs . Mor

e energ y i s expended int

o fewe r egg s tha t hatch mor

e develope d larva

e tha n th e tax awit

h pelagi c eggs . Thi s strateg y i s advantageou s whe n combined wit

h th e demersa

l egg s sinc e thi s latte

r adaptatio n reduce s otherwis e hig h eg g mortalities . Thus , eg g an d larva l surviva l rate s u p to the poin

t of entrainment

ar e directly linke

d to th e reproductiv e strateg y ofth e particula r specie s being assesse dan

d hav e marked effects o

n th e demographi c approache s used fo r estimatin g entrainmen

t effects . Th

e AEL approach depend s o

n surviva l estimate s fro

mth e time o f entrainmen

t to recruitment

o f adult s int o th e fishery . Estimate s o f

survivorship ar

e undocumente dfo

r man y ofth e tax aconsidere d i

n thi s repor

t an d therefor e they ha d to b e estimate do

r substitute dfro

mother relate d taxa . Th

e leve l of uncertaint y associate d wit

h thes e survivorship estimate s i s typicall y unknow n an d ca n contribut

e t o overall uncertaint

y i n th e estimate s fro

mthes e approaches . Thi s als o show s the importanc e o f larva l duratio n i

n the formulation ofth e approaches . Difference s i n lif e historie s an

d adult distribution s wer

e accounte d fo r i n the formulation ofth e ETM among taxa . Fo

r example , pelagi c specie s tha t release d planktoni c egg s ar

e treate ddifferentl

y fro mnearshor

e specie s wit

h demersa l eg g masse s b

y estimatin g th e populatio n o f inferenc e using offshor

e extrapolatio n an

d alongshor

e extensio n of stud y gridabundance . Th e availabilit

y o f lif e histor y information allowed multipl e assessmen t approache s t

o b e use d o n severa l ofth e target

taxa , bu t i n the absenc e of

independen

t populatio n estimate s fo

r thes e taxa , ou r abilit y to asses s effects wa s limited . Fo r example , demographi c datao n eg g an d larva l mortalit y fo r blackey e goby allowe d the applicatio n of multipl e assessmen

t approaches , bu

t i n the absenc e of apopulation assessmen

t o r an y fisher y datafo r thi s specie s we could no

t provid e an y contex t fo r the estimates . The utilit

y of an y modeling techniqu e to yiel d relativ e assessment s of population-level effects depend s o n datadescribin g the siz e ofth e adul t fish population s an

d the abilit y to conver

t FH, AEL, an

dETM estimate s int

o comparabl e unit s of

fishe s i n th e wild .

TENERA E9-055. 0 7-1 1 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.8 0 7. 0 Discussio n Fo r tax awher e all thre e assessment

approache s wer

e completed , compariso n amon g th e result s illustrate th e usefulnes s ofth e multipl e assessment approach . While th e rang e an d varianc e o f

lif e histor y parameter s an

dpopulatio n estimate s ar

e source s o f

uncertaint y i n ou r estimates , w e ca

n determin e ou

r area s o f uncertaint y throug h mode

l comparison . Wher

e bot h FH an d AEL estimate s exist , assumin g a50:5 0 se x rati o and alignin g th e age s o f recruitment

an d maturation , th e model s ca

n b e compareddirectl y usin g th e relationship AEL = 2FH presente d i

n previou s assessment

report s (Tenera1999a , b) . Thi s conversio n require s tha t age s o f AEL an d FH individual s ar

e aligne dan

dequal . Th e result s fro

mth e demographi c approache s ar e i n simila r unit s o f either adult female s (FH) or

adult s (AEL). The FH and AEL mode l estimate s fo

r some ofth e targe t

tax awer e no t i n particularl y clos e agreement (Tabl e 7-lb) . Th e age-aligne d estimate fo r 2FHwas ove

r 4 time s greater

tha n th e initia l AEL estimate fo

r Pacifi c sardine . I

n contrast , th e FH

estimate s fo

r sanddab s wer

e lo w relativ e t o AEL. Whe

n FH estimate s are aligne d fo

r ag e th e estimate s remai n low , relativ e t o AEL. Sensitivit

y analyse s wer

e conducte d t o hel

p determin e th e parameter

estimate s contributin g th e greates t

influenc e o

n th e FH and AEL estimates . The uncertaint

y associate d wit

h man y ofth e parameter s resulte di

n th e us e o f

acoefficien

t o f variatio n o f

100 % t o estimate thei r

variance , i

n accordanc e wit

h ETW G recommendations . Thi s reduced th e usefulnes s ofth e sensitivit y analyse s i n interpretin g mode

l results . Result s fo r target tax atha t wer e i n clos e agreemen

t wit h th e relationship 2FH

= AEL (subjec t to ag e alignment) provide som e assuranc e tha

t th e parameter s use

d i n th e model s wer

e representativ e fo

r th e centra l Californi apopulation s we sampled . The y als o increas e confidenc e tha t th e assessment s o f

effect s o n thes e population s ar

e reasonably accurate . Tw o example s wer e norther n anchovy an

dthe blu e rockfis h complex . I n th e blue rockfish complex , FH an d AEL estimate s wer

e use dto extrapolate populatio n leve l effect s using loca

l fisher y landing s (Sectio n 5.2.4) . Using a

n estimate ofth e weigh

t pe r adult blu e rockfish i

n th e fisher

y o f 0. 5 kg , a n estimate dAEL

o f 34 3 adult s represente d 172 k g o f 3 yr old recruits , ca . 1 % ofth e catch lande d i n th e Morr o Ba y are ai n 1999 , an dvalue d a t approximately $740 . Blue rockfish P XI range i fro

m 0.004-0.02 , bracketin g th e _4£Z.-base d percentag e o f

catch . I t wa s als o relativel y linea

r ove r a n

TENER A E9-055. 0 7-1 2 Fina l 316(b ) Demonstratio n Marc h 1,200 07. 0 Discussio n

extrapolate dare ao f

220-1,10 0 km

- (smalle r mortalit y associate d wit h large r areas) . Despit e th e limitation s an dassumption s ofth e models , th e result s ofth e assessmen t for th e blu e rockfis h comple x provid e assuranc e tha t th e effect s o n thi s taxo n ar e low . Mode l assumption s als o nee d t o b e considere d whe n interpretin g th e larg e FH estimat e fo r

brow n roc k crab s (Tabl e 7-la) . Th e estimate d numbe r o f reproductiv e adult s usin g th e FH mode l wa s extrapolate d t o know n fishery-sizedanimal s usin g estimate s o f adul t mortalit y becaus e female s ar e reproductiv e befor e the y ente r th e fishery . Thi s reduce d th e FH estimat e b y a

n orde r o f magnitude . Therefore , becaus e ofth e additiona l assumption s require d for th e FH estimate , th e estimat e o f

P AI wa s use d i n extrapolatin g fishery effects . I f al l larva l stage s in th e populatio n ar e equall y entrainable , the n th e estimat e o f P AI tha t wa s base d o n megalop s woul d b e representativ e o f al l larva l stages . Thi s assumptio n wa s mad e whe n P KI wa s applie d t o th e catch . Fo r targe t tax awithou t

availabl e lif

e histor y information , measurement s o f larva e fromth e entrainmen t

an d stud y gri d provide d som e insigh t int o thei r

larval lif e histor y an d ecology . Th e lengt h range s fo r

mos t ofth e entraine d targe t

larva l fish tax aindicat e tha t thei r exposur e t o entrainmen t

occur s ove r

arelativel y shor t

tim e perio d durin g thei r development . Th e length

frequencie s for

severa l ofth e targe t

taxa , includin g KG B an d blu e rockfis h comple x larvae , larval painte d greenling , cabezon , an d blackey e goby , appeare d normall y distributed . Averag e length s wer e smal l demonstratin g tha t the y wer e expose d t o entrainmen t for abrie f perio d durin g thei r larva l development . Thi s suppositio n i s supporte d b y anothe r characteristi c commo n t o thes e taxa ; ver y fe w flexion o r post-flexio n larva e wer e entrained . Flexio n an d post-flexio n stag e larva e hav e mor e develope dswimmin g abilitie s tha n younge r individual s an d coul d b e avoidin g th e net s an dpotentiall y entrainment . Th e lac k o f thes e late r

developmenta l stage s i

n ou r sample s ma y als o indicat e tha t

thes e tax ademonstrat e larval behavio r tha t remove s the mfromris k

o f entrainmen t a s the y develo p (e.g. , settlemen t t o benthi c habitat s o r

migration int o deepe r

area s awa y fro mth e intake) . In contrast , th e length-frequenc y distribution s fo r th e tw o targe t

tax awith evidenc e o f localize dentrainmen t

effects , clini d kelpfishe s an d snubnos e sculpin , wer e skewe d an d include d large r individual s tha n othe r

taxa . Thus , i

t appear s tha t

thes e tw o tax aar e expose d t o entrainmen t ove r longe r period s o f

developmen t

tha t includ e flexion an d post-flexio n stag e larvae . A n

TENER A E9-055. 0 7-1 3 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.8 2 7. 0 Discussio n extende dduratio n o f

exposur e t o entrainment

ma y partiall y explai n th e apparen t decline s i n adul t an dlarva l abundanc e fo

r thes e tw o taxa . Paradoxically , th e extende d exposur e to entrainment

tha t apparentl y result s i

n localize deffect s o

n thes e tax ama

y als o insur

e tha t localize d effects d o no

t becom e greate r population-leve l effects . Extende d planktoni c duratio n will allo w fo r larva l transpor t an ddispersa l to occu r ove r amuc h large r area . 

### 7.2. 4 Populatio n Distributio n The assessmen

t considere dtax atha

t occurre d i

n th e entrainment

sample s a t DCPP . Thei

r abundanc e depende do

n tempora l an d spatia l distributio n o f

adult s a s well a s larva

l lif e stages . Th e tax aca n b e describe da s pelagi c (Cancer crabs , Pacifi c sardine , an

d norther n anchovy) , subtida l (rockfishes , painte dgreenling , snubnos e sculpin , cabezon , whit e croaker , blackey e goby , sanddabs , an

dCaliforni ahalibut) , an

d nearshor e subtida l an d intertida l (smoothhea

d sculpin , monkeyfac e prickleback , an dclini dkelpfishes) . Thes e differen t spatia l distribution s contribute d to the ETWG' s decisio n to us e tw o strategie s i n applyin g th e ETM. Nearshor e specie s populatio n siz e wa s assesse dby alongshore extensio n o f stud y gri d abundanc e only ; otherwise , a n offshor e extrapolatio n o f

stud y gri dabundanc e wa s conducte d an d the n extende d alongshore . Thes e expansion s ofth e stud

y gri dabundanc e wer

e based o n measure s o f

curren t speed an d directio n a

t th e DCP P current meter statio n an dconstraine d b

y larva l age s a t entrainment . Th e ETM approach applie dto all target tax arequire d a

n estimat e o f apopulatio n tha

t wa s defined b y extrapolatin g larva

l densit y ove r a n are adelimite d b

y estimate d larva

l duratio n combine d wit

h curren t speedan ddirectio n i

n th e stud y period . Estimate s o f

tota l annua l entrainmen

t mortalit y ( P u ) rely o

n th e estimate s of

P s ( #o f larva e a t risk i n th e stud y grid/ #o f larva e i n the populatio n o f inference) . Th

e result s fo

r target fish tax ai n thi s 316(b ) stud

y indicat e tha t whil e som

e entrainment

effects remain localized , othe r effects ca n b e sprea d ove r wide area s o f

inferenc e (Tabl e 7-2) . Whe n estimate dlarva

l duration s wer

e relativel y shor

t an d th e subsequen

t are acontainin g th e populatio n o f

inferenc e remaine drelatively small , th e extent o f extrapolatio n wa s als o small , base do n th e current

meter data . Unde

r thes e conditions , P s wa s likely amor e precis e estimate , potentiall y les s susceptibl e t o mode l bias , resultin g i

n amor e accurat e estimat e o f entrainment TENER A E9-055. 0 7-1 4 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.8 3 7. 0 Discussio n effects , P S1 . Ther e i s les s confidenc e i n ou r estimate s o f

P s wher e th e extrapolate d area s wer e substantiall y large r

tha n th e stud y grid . Th e varianc e component , resultin g fromdensit y estimate s projecte d offshor e wel l beyon d th e zon e tha t th e measurement s represented , wa s no t include d in ou r varianc e estimate s o f

P M (Appendi x F) . Thus , th e estimate d referenc e populatio n o f fishe s with short

larva l duratio n o f

exposur e (e.g. , cabezo n an d blackey e gobies ) ar e potentiall y mor e precis e than thos e with alon g tim e o f susceptibilit y t o entrainmen t (e.g. , crab s an d Pacifi c sardine) . However , th e situatio n fo r nearshor e specie s i s mor e complex . Fo r example , thos e with longe r time s o f susceptibilit y t o entrainmen t (durations ) ma y dispers e int o th e stud y gri d area , becomin g mor e availabl e t o plankto n samplin g gear , resultin g i n bette r estimate s o f

P KI . I t i s unlikel y tha t

area s o n th e orde r

o f hundred s t o thousand s o f time s greate r

tha n th e stud y gri d ar e representativ e ofth e actua l are aaffecte d b y entrainment . Therefore , whe n P M wa s applie d t o astoc k assessmen t

o r fishery (e.g. , fo r

norther n anchovy) , i t

wa s base d o n aproportio n o f area s (are ao f extrapolatio n /

stoc k assessmen t

area) . In som e cases , thi s proportio n wa s mor e approximat e and , fo r

brow n roc k

crab , relie d upo n a

n estimat e ofth e fishery grounds . Targe t tax atha t ar e no t commerciall y o r

recreationall y harveste d ar e primaril y small , nearshor e fishes . A s migh t

b e expecte d du e t o th e shallo w water , shorelin e locatio n ofth e DCP P intak e structure , severa l o f

thes e tax aar e entraine d i n relativel y hig h numbers , resultin g i n larg e P KI estimate s (Tabl e 7-2) . Fo r example , adul t

kelpfis h occu r

i n rocky , nearshor e habita t an d als o ha d on e ofth e highes t

P KI estimate s (ca . 30-40%) . I f w e us e onl y th e alongshor e estimat e o f P s for calculatin g P

XI t o compar e results , thos e tax awit h nearshor e distributions , includin g smoothhea d sculpin . snubnos e sculpin , an d monkeyfac e prickleback , ha d relativel y larg e P SI estimates . Thei r greates t larva l abundanc e occurre d i n th e stud y gri d cell s closes t t o shore . Thi s distributio n i s consisten t wit h thei r adul t distributions . Confidenc e i n estimate s o f

entrainmen t

mortalit y fo r nearshor e an dintertida l fishe s i s supporte d whe n notin g tha t P u for thes e tax adoe s no t

vary betwee n extreme s o f

larva l age s a

t entrainmen t

whe n extrapolatin g larval abundanc e alongshore . Althoug h entrainmen t

samplin g occurre d at

th e shorelin e intak e wher e thes e nearshor e tax aar e i n greates t abundance , th e stud y gri d samplin g di d no t adequatel y sampl e othe r nearshor e areas . Therefore , modification s wer e mad e t o th e calculation s o f PE t o accoun t

for nearshor e volume s TENER A E9-055. 0 7-1 5 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.8 4 7. 0 Discussio n tha t wer e no t sampled . Whil e th e additio n o f thes e inshor

e volume s ma

y hav e overestimate d P SI fo r som e o f thes e taxa , estimate s fo

r blackey e goby an

d Californi ahalibut , specie s tha t ha d broade r adult distributions , wer

e als o hig h (July 1998-Jun e 199 9 perio d only : Tabl e 7-2) . Blackey e goby larva

e ( P M »20% ) wer

e distribute d throughout

th e stud y gri d an d occur a s adult s fro mth e intertida

l out t o recorde ddepth s o f

ove r 10 0 m(Eschmeye

r et al . 1983) . Th

e relativel y hig h P ht fo r blackey e gob y ma

y b e due , i n part , to the hig

h densit y o f adult s directl y i

n fron t o f th e intak e structure . Entrainment

o f larva e hatche d fro

mdemersa

l egg s withi n Intak

e Cov e ma

y explai n ou r estimate o f

larva l duratio n ( 6 d ) tha

t i s considerably shorter

tha n literature value s (7 5 d) . Therefore , whil e i

t i s likel y tha

t some bia s i s introduce d int o th e estimate s o f

P KI du e t o th e nearshor e area s not

sample db

y th e stud y gri d surveys , th e bia s i s probably specie s dependent an d ma y no t b e relate dsolely t o adult

distributions . I n contras t to specie s wit

h nearshor

e distributions , estimate s o f P M fo r specie s wit

h mor e widespread , pelagi c larva

e (e.g. , Pacifi c sardin e an

d norther n anchovy ) wer

e low , a s expecte d b

y thei r long larva

l duration s andlarg e area s estimate d b y alongshor

e and offshor

e extrapolation . A

n assumptio n ofth e ETM

is tha t larva l distribution s i

n th e nearshor

e stud y gri d ar e representativ e o f densitie s i n the are ause

dfo r calculatin g P s . Whil e thi s assumptio n ma y b e reasonabl e fo

r value s o f P s tha t represent relativel y small area s o f

coastline , densit

y i n th e gri d i s probably no

t representativ e o f

offshor e area s use

d i n calculatin g P s fo

r pelagi c an

d subtida l species . A s a result , applyin g P hl

to stock assessment s o

r fisherie s dat

ama y not accuratel y represen

t entrainment

effect s becaus e densit

y i n th e nearshor

e stud y grid i s probably not

representativ e of averag e densit

y i n th e area s usedfo

r estimatin g standin g stoc

k biomass . However , th e extrapolatio n ofth e larva

l densit y trend s observed i

n the stud y gri d out to water s furthe

r offshor e wa s a n attemp t t o accoun t fo r thi s inaccuracy . Whe

n P s , was applie d t o th e fisher y stoc k assessment

b y proportiona

l area , i n th e cas e of

norther n anchovy , th e biomas s wa s simila r to tha t determine dusin g th e tw o other method s of

estimatin g adult

losses , AEL

an d FH. The clos e correspondenc e i

n result s fo

r th e differen

t model s suggest s tha

t th e methodolog y wa s appropriate , an d give s u s confidenc e i

n th e accurac y ofth e results .

TENER A E9-055. 0 7-1 6 Fina l 316(b ) Demonstratio n Marc h 1.200 0

# I I I I I I 1 I I I I 7. 0 Discussio n



### 7.2. 5 Magnitud e o f Effect s Result s fro mth e presen

t stud y indicat e tha t effect s o n commercially an

d recreationall y harveste d specie s wit

h subtida l or pelagi c distribution s ar

e minimal . Fo

r case s wher

e we wer e abl e to appl

y all thre e assessmen

t approaches , th e effect s detecte d wer e relatively small , appeare d t o b e localized , an

dthu s couldnot

affec t th e overal l adul t

populations . Thes e conclusion s ar e supporte db

y result s fo

r tax asuc h a s KG B rockfishe s wher

e the estimate d lo

w level s o f entrainmen

t effect s wer

e corroborate d b

y th e corollar

y datatha t showe d no consequen

t adult abundanc e o r

larva l productio n decreases . Whil e th e alignmen t o f result s amon g assessmen

t method s fo

r othe r commercially o

r recreationall y importan

t tax awa s les s compelling , i t nevertheles s didnot

indicat e th e potentia

l fo r an y significan

t long-ter mpopulation-leve l effects . Ther e wa s ver y littl e availabl e information describin g th e demograph y o f targe t tax atha t wer e no t commercially or

recreationally importan

t an d thi s limited th e applicabl e assessmen t approache s t o th e ETM. Thes e wer e typicall y tax adistribute d nearshor e a s adults , renderin g their larva e highly susceptibl e t o entrainment . I n fact , thes e tax awer

e included i

n th e targete d lis t

b y the ETW G becaus e of

their hig h abundanc e i

n entrainmen

t samples . Th

e ETM approach showed tha t entrainment

couldremove 10-40 % ofth e annua l larva l production o f

severa l of thes e nearshor e an dintertida l taxa . I n som e o f thes e cases , corollar

y dataindicat

e tha t entrainment

i s " — ' vc f probably only removing surplu s productio n sinc e ther e ar e no apparen

t long-ter mdecline s i

n loca l adult populations . Fo

r thos e nearshor

e tax atha t d o no t displa y decreasin g adult

abundance , i t i s apparen

t fro mthei r length-frequency distribution s tha t they wer e expose d t o entrainmen

t mortalit y fo r abrie f portion o f their early development . I

n contrast , fo

r kelpfishe s an

d snubnos e sculpin , whos e adul

t abundanc e d

o appea r to b e decreasin g (wit

h correspondin g decline s i

n long

ter mplankto n to w index) , the length-frequenc y distribution s indicat e alonge r duratio n o f exposur e to entrainment . Th

e combinatio n of

length-frequency analyse s wit h th e ETM

estimate s offe r suppor t to th e conclusio n tha

t som e nearshor e tax aar e affecte d differentially b

y entrainment . Th

e increasedduratio n o f

exposur e to entrainmen

t fo r kelpfishe s an

d snubnos e sculpin ma

y als o insur

e tha t thes e effects remain localized sinc e extended planktoni c duratio n provide s additiona

l opportunit

y fo r larva l transpor t an d dispersal . TENERA E9-055. 0 7-1 7 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.8 6 7. 0 Discussio n 

## 7. 2 Summar

y Assessmen t I n summary , population s o f fishe s an d crab s do no t

appea r to b e adversely affecte

d bv th e DCP

P coolin g wate

r intak e structure . Som

e ar e commercially importan

t tax awit h pelagi c egg s an

d widesprea dpopulation s (e.g. , norther n anchovy , Pacifi c sardine , white croaker , sanddabs . and Californi ahalibut) . Thei

r assessment s resulte d i

n either low estimate d larva

l mortalitie s or

small number s o f

adult losse s to thei r

populations . Othe

r widesprea

d specie s als o ha

d lo w number s o f estimate dadult

equivalent

losse s t o thei r

population s and lo w estimate d larva l mortality , wit

h population s tha

t ar e distribute dwell beyond th e zon e o f influenc e o f

DCPP . Thes e included commercia

l specie s (rockfishes , crab , an d cabezon) . Fiv e tax a(smoothhea d sculpin , snubnos e sculpin , monkeyfac e prickleback , clini d kelpfishes , and blackey e goby ) ha d larva l mortalitie s tha

t exceede d10 % i

n referenc e t o tha

t par t ofth e populatio n livin g i

n a n are a2- 8 time s th e stud

y gri d area . Fo r mos t o f thes e (excep t

kelpfishe s an

d snubnos e sculpin) , subtida l observation s o f

adult s an dlong-ter mplankto n samplin g o f

larva e showe d n o declin e i

n number s ove

r recent year s i n th e vicinit y o f DCPP . Effect s o

n kelpfishe s an

d snubnos e sculpi n appea

r to b e localize d an

d th e are a affectedi s asmall par

t o f thei r tota l geographi c distribution . The model s usedfo

r entrainment

assessmen

t considere d function s critica l t o th e lif e histor y ofth e 1 6 target taxa . Thes e model s wer

e applie d bot

h a t th e poin t o f entrainmen

t fo r estimatin g th e number s of

individual s entraine dan

d als o i n th e adjacen

t offshor e area s fo r estimatin g th e populatio n o f

inference . W

e als o considere d migratory , pelagi c specie s an d othe r widesprea

d tax a differentl y tha n nearshor

e tax ai n estimatin g the populatio n o f inference . Th

e are aaround DCP

P encompasse s nurser

y an dfeeding area s fo

r man y specie s includin g th e 1 6 target taxa . Thes e area s als o extendwel

l outside th e DCP

P zone o f influenc e an

d i n the case s of

norther n anchovy an dPacifi c sardin e th e center ofth e spawning biomas s i s located sout h o f Poin t Conception . Measurement s o f

larva e indicat e tha t mos t ofth e targe t

tax aar e exposed to entrainment

fo r a relativel y shor

t perio do f tim e durin g their

larva l development

an d thu s wer e produce d locally . Thes e result s indicat

e tha t entrainmen

t effect s appea

r t o b e limited to localize d effect s o n nearshor e species . Therefore , the potentia l fo r damag e du e to entrainmen t o n th e biologica

l valu e ofth e sourc e wate

r bod y i s low . TENER A E9-055. 0 7-1 8 Fina l 316(b ) Demonstratio n Marc h 1,200 0.->- , r 

# I I I I 1 I I I I I I I 

# I 7. 0 Discussio n



## 7. 3 Best Technolog y Availabl e Althoug h n o advers e environmenta l impac t wa s determined , ageneri c revie w o f alternativ e coolin g wate r

technologie s applicabl e t o DCP P wa s evaluate d i n Sectio n 6 . A hierarchica l se t o f thre e criteri awer e applie d t o th e alternative s tha t wer e considered : A revie w o f

alternativ e coolin g wate r technologie s applicabl e t o DCP P wa s evaluate d i n Sectio n 6 , a s require db y th e RWQCB . A hierarchica l se t o f thre e criteri awer e applie d t o th e alternative s an dconsidered :

• availabl e technolog y with demonstrate d operabilit y an d reliabilit y at intake s simila r t o DCPP ;

• areductio n i

n th e los s o f

aquati c organisms ; an d

• applicabilit y a t

DCPP , base d o n engineering , operations , an d reliabilit y considerations . Th e technolog y assessment s examine d modification s tha t ma y affec t

impingemen t

an d entrainmen t

althoug h impingemen t

rate s ar e ver y lo w a t

DCPP . Site-specifi c studie s determine d impingemen t

rate s wer e lo w rangin g betwee n 0. 3 an d 0. 7 k g pe r da y pe r unit , whic h i s equivalen t t o 36 0 kg/y r

fo r bot h units . Compare d t o othe r wes t coas t generatin g station s (Tener a1998a ) tha t imping e betwee n 2,80 0 t o 24,10 0 kg/yr , impingement a t DCP P doe s no t

represen t a h advers e environmenta l impact . Consultatio n with industry authoritie s an d publishe d engineerin g evaluation s o f

demonstrate dtechnologie s applicabl e t o reducin g entrainment , reveale d fe w intak e modification s tha t

migh t reduc e th e densit y offis h larva e at ris k t o entrainmen t

i n acos t effectiv e manner . Althoug h severa l facilitie s hav e reduce d entrainmen t b y modifyin g intak e scree n systems , th e hars h coasta l environmen t at DCP P preclude s applicatio n o f thes e strategie s withou t extensiv e site-specifi c testing . Reductio n o f operatio n t o period s whe n fish densitie s ar e lowe r wa s considere d no t

viabl e i n th e curren t

powe r exchang e pricin g environment . Replacemen t o f th e heat exchang e processe s fromopen-cycl e seawate r coolin g system s t o closed-cycl e coolin g towe r strategie s wa s determine d t o b e economicall y unfeasibl e an d adde d substantia l environmenta l ris k

t o terrestria l communities . A s discusse d i

n th e othe r

section s o f

thi s report , DCP P i s no t

causin g a

n advers e environmenta l impac t (AEI ) an d therefor e n o consideratio n o f alternativ e coolin g wate r intak e structur e TENER A E9-055. 0 7-1 9 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.8 8 7. 0 Discussio n technologie s fo

r minimizin g AE

l i s necessary . However , thi s assessment o f altemativ e technologie s i s include di

n respons e t o arequiremen t b y th e RWQCB . Th e conclusio n based o n thi s assessmen

t i s tha t th e existin g coolin g wate

r intak e structur e i s th e bes t

technolog y availabl e fo r DCPP .

TENER A E9-055. 0 7-2 0 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.8 9 

# I 1 1 I I I 

# I I I I I 

# n w i i i i i i i 7. 0 Discussio n

Tabl e 7-la . Estimate s o f

fecundit y hindcas t adult female s (FH) an

d projecte d equivalen

t adult s ( AEL ) i n number s o f

individual s fo

r Analysi s Period s 1 (Decembe r 1996-Novembe

r 1997 ) an d 3 (July 1997-Jun e 1998 ) fo r th e tw o targe t

cra b tax acollecte d an

d analyze d a

t DCP P wit h their potentia l relativ e value .
Taxo n Brow n roc k

cra b

Slende r cra b Analysi s

Perio d 1 . 3 . 1 . 3 . FH

117,00 0 (11.700) a 91,00 0 (9.100 ) a 27,30 0 (2,730 ) a 8.95 0 (895) a AEL

234,00 0 (23,400 ) b 182.00 0 (18.200 ) b 54.60 0 (5.460 ) b 17,90 0 (1.790 ) b Interprete d Annua l Valu e

(applie d modelin g approach ) $1,09 0 c $2,17 0 c (FH) (AEL) $84 5 c $1,69 0 c (FH) (AEL)

n o fisher y valu e n o fishery valu e $1,76 0

(ETAf) $2,04 0 (ETAf)

•

aEstimat e extrapolate d t o fishery-size d femal e crabs . " Estimat e extrapolate d to fishery-size d crabs , bot h mal e an d female . c Valu e based o n assumptio n o f 10 % vulnerabilit

y t o fisher

y (fro m mark-recaptur

e experiments an

d fisher, recaptur e data : se e Sectio n 5.2.1.1).

TENER A E9-055. 0 7-2 1 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.9 0 7. 0 Discussio n Tabl e 7- 1 b . Estimate s o f

adjustedannua

l entrainment

(E AJhT ), fecundit

y hindcas t adul t female s ( FH ) , an dprojecte dequivalent

adult s (AEL

) i n number s o f

individual s fo

r Analysi s Period s 1 (Octobe r 1996-Septembe

r 1997) , 2 (Octobe

r 1997-September

1998) , an d 3 (July 1997-Jun e 1998 ) fo r th e 1 4 target

fis h tax acollecte d an

d analyze d a

t DCP P wit h their potentia l relativ e value . Whe

n mor e tha n one valuatio n procedur

e wa s used , th e larges t

valu e i s listed . Th e tota

l numbe r of targe t tax aimpingeddurin g Apri l 1985-Marc h 198 6 ar e included fo

r comparison . Taxo n Analysi s

Perio d 'Adj-T FH AEL Pacifi c sardin e

Californi a halibut * Tota l Impinge d 1985-8 6 Interprete d Annua l Valu e

(applicabl e valuatio n method ) 8.470.000 22.600.00 0 22.600.00 0 3.17 0

8.460 8.460 2.63 0

7.00 0 7.00 0 0 $71 0 (ETM modeling applie d t o reductio n an d liv e bai t fisheries ) Norther n anchov y KG B rockfis h comple x Blu e rockfis h comple x Painte d greenlin g Smoothhea d sculpi n Snubnos e sculpi n Cabezo n Whit e croake r Monkeyfac e pricklebac k Clini d kelpfishe s Blackey e gob y Sanddabs * 1 . 2 . 3 . 1 . 2 . 3 . 1 . 2 . 3 . 1 . 2 . 3 . 1 . .2 . 3 . 1 . 2 . 3 . 1 . 2 3 . 1 . 2 . 3 . 1 . 2 . 3 . 1 . 2 . 3 . 1 . 2 . 3 . 1 . 2 , 3 . 136.000.00 0

376.000.00 0 377.000.00 0 275.000.00 0 222.000,00 0 222.000.00 0 84.040.00 0 33.800.00 0 33,900.00 0 24.200.00 0 9.610.00 0 12.100.00 0 57.700.00 0 115.000.00 0 129.000.00 0 110.000.00 0 83.500.00 0 105.000.00 0 51.900.00 0 36.300.00 0 36.300.00 0 305.000.00 0 440.000.00 0 447.000.00 0 83.100.00 0 61.500.00 0 60.200.00 0 181.000.00 0 308.000.00 0 458.000.00 0 128.000.00 0 109.000.00 0 128.000.00 0 7.160.00 0 1.540.00 0 6.610.00 0 16,10 0

44.70 0 44.70 0 61 7 49 7 49 7 4 3 1 8 2 0

5.11 0 7.38 0 7.50 0

12.00 0 10.30 0 12.10 0 42 6 9 2 39 3 43.20 0

120.00 0 120.00 0 1.12 0 90 5 90 6 35 3 16 4 14 2

14.700 t 21.300 t 21.600 t

75.20 0 64.10 0 75.40 0 2.37 0 51 1 2.19 0 1

1 2
8

1 1 0 9 1 0

0
17 . 0 4 $57 6

(AELand ETM modelin g applie d t o non-reductio n wetfis h fishery )

$20,00 0 (ETM modeling applie d t o commercia l live-fis h fishery )

$1,23 0 (ETM modeling applie d t o commercia l fishery ) forag e specie s (n o economi c valuation ) forag e specie s (n o economi c valuation ) forag e specie s (n o economi c valuation ) $9,00 0 (ETM modelin g applie d t o commercia l live-fis h fishery )

$87 2 (AELmodelin g applie d t o commercia l fishery:) n o demographi c o reconomi c data wer e availabl e fo rthi s specie s t o estimat e adul t losses o rfishery valuatio n forag e specie s (n o economi c valuation ) forag e specie s (n o economi c valuation )

$8 2 (ETM modelin g applie d t o commercia l fishery) 8.260.00 0 15.700.00 0 15.500.00 0 $10,06 0 (ETM modelin g applie d t o commercia l fishery )

—= no t estimate d * = entrainmen t

estimate s wer e no t

adjuste d t o th e long-ter m(1990-98 ) Intak e Cov e plankto n to w mea n t = 2FH aligne dt o fishery-ag e adul t equivalent s TENER A E9-055. 0 7-2 2 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.9 1 

# I I 1 1 I I I 1 I I I I 7. 0 Discussio n

Tabl e 7-2a . Tota l annua l entrainmen tmortalit y (P M ) an d zon e o f

extrapolatio n (1 /

P s ) a s a multipl e o f

stud y gri d area s (usin g alongshor e currents ) o r o f stud y gri d populatio n (usin g alongshor e an d offshor e extrapolation ) fo r larva e ofth e tw o targe tcra b tax a fro m Analysi s Period s 3 (Jul y 1997-Jun e 1998 ) an d 4 (Jul y 1998-Jun e 1999 ) estimate d b y usin g 2 method s o f calculatin g P

s usin g maximu m larva l duratio n estimate s throug h th e megalop s stag e atDCP P an d wate r curren tmeasurements . P s calculate

d usin g alongshor

e current s Taxo n Analysi s

Perio d 

# ft brow n roc k cra b slende r cra b 3 .

3 . 4 . 0.0056 3

0.0065 2 0.084 4 0.011 3 8. 3

9. 3 8. 1 7. 9 P

s calculate

d usin g alongshor

e current s an d extrapolatin

g densitie s offshor e 'M 

# ft 0.000018 6 0.00014 6 0.0107 0.00078 4 2.590. 7 417. 6 236. 9 114. 2

TENERA E9-055. 0 7-2 3 Fina l 316(b ) Demonstratio n Marc h 1,200 07. 0 Discussio n

Tabl e 7-2b . Tota

l annua l entrainment

mortalit y (P AI ) an d zon e o f extrapolatio n ( \/P s ) a s a multipl e o f

stud y gri darea s (usin g alongshor e currents ) o r

o f stud y gri d populatio n (usin g alongshor e an doffshor e extrapolation ) fo

r larva e ofth e 1 4 targe t

fis h tax afro mAnalysi s Period s 3 (Jul y 1997-Jun e 1998 ) an d4 (July 1998-Jun e 1999 ) estimate d b y usin g 2 method s o f calculatin g P s usin g bot

h mea n an dmaximu mlarva l duratio n estimate s derive d fro mlength s o f entraine dlarva

e a t DCP P an dwate r current measurements . P s calculate d usin g alongshor e cunent s - P s calculate

d usin g alongshor e current s an d extrapolatin g densitie s offshor e

Taxo n Pacifi c sardin e northe m anchov y KG B rockfishe s blu e rockfis h comple x painte d greenlin g smoothhea d sculpi n snubnos e sculpi n cabezo n whit e croake r monkeyfac e pricklebac k clini d kelpfishe s blackey e gob y sanddab s Califomi a halibu t Analysi s

Perio d 3 . 4 . 3 . 4 . 3 . 4 . 3 . 4 . 3 . 4 . 3 . 4 . 3 . 4 . 3 . 4 . 3 . 4 . 3 . 4 . 3 . 4 . 3 . 4 . 3 . 4 . 3 . 4 . base d o n

mea n duratio n 

# K

—

-

-

• - 0.036 5 0.038 0 0.0033 8 0.047 1 0.049 0 0.031 9 0.10 5 0.14 6 0.10 2 0.20 2 0.024 3 0.014 0 0.019 0 0.036 6 0.16 2 0.10 8 0.31 8 0.29 4 0.19 0 0.17 4 0.014 5 0.066 3 0.0026 9 0.17 5 

# ft

—

-

—

- 2. 8 2. 5 2. 6 2. 0 3. 6 3. 6 2. 8 3. 0 2. 0 1. 5 2. 5 1.4 2. 8 1. 9 3. 0 2. 4 3. 1 2. 7 1. 3 1. 2 2. 4 1. 8 2. 8 2. 3 base d o n max . duratio n 

# K,

—

-

_

- 0.053 2 0.037 6 0.0046 8 0.041 1 0.067 1 0.038 1 0.15 3 0.19 8 0.14 4 0.23 9 0.033 7 0.016 1 0.029 7 0.055 0 0.23 2 0.11 3 0.41 0 0.39 5 0.22 8 0.22 0 0.015 7 0.053 7 0.0044 9 0.25 2 

# ft

_

-

—

- 5. 1 6. 7 4. 1 5. 0 6. 2 7. 3 7. 3 8. 2 4. 3 4. 2 3. 5 2. 5 5. 5 3. 9 6. 9 8. 0 7. 3 6. 2 2. 4 1. 8 3. 2 3. 5 6. 1 5. 4 base d o n mea n duratio n 

# K 0.00028 4 • 0.00057 5 0.0020 5 0.014 6 0.021 8 0.00095 5 0.021 1 0.0087 7 0.011 4

—

- 0.036 1 0.120 6 0.0068 3 0.0083 5 0.0025 5 0.021 1

-

-

-

- 0.13 1 0.16 3 0.0049 3 0.045 9 0.00083 5 0.12 3 

# ft

47. 3 16. 5 7. 9 7. 2 4. 4 9. 3 4. 6 20. 7 10. 3

—

- 7. 0 2. 6 9. 1 2. 4 21. 2 3. 4

-

-

-

- 2. 0 1. 3 11. 7 2. 7 8. 9 3. 5 base d o n

max . duratio n 

# K 0.000066 9 * 0.000078 6 0.00020 1 0.0096 2 0.0047 6 0.00045 6 0.0035 6 0.0091 0 0.0044 4

-

- 0.023 1 0.021 0 0.0056 9 0.0091 9 0.0013 3 0.0070 4

-

-

-

- 0.078 7 0.17 9 0.0041 3 0.010 6 0.00076 3 0.052 5 

# ft

1.078. 1 683. 8 454. 5 29. 5 53. 9 42. 1 60. 0 47. 7 63. 9

-

-39. 3 55. 8 21. 8 4. 4 127. 5 32. 3

-

-

-

- 8. 6 2. 5 22. 4 18. 5 35. 9 32. 8 "-"n o calculation s of

thi s clas s mad

e fo r thi s taxon * No Pacific sardine larva e wer e collecte d i

n paired entrainmen

t an d stud y gri d sample s fo

r thi s period . TENERA E9-055. 0 7-2 4 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.9 3 

# I I 1 I I I I I I I 8 U 

# I I 1 I I I I 7. 0 Discussio n

c O

a> J D E 3 Z C O c "5 > ra 8 > o Equilibriu m Populatio n -

( ^ * * * r^*J*f

pt* r*' * ' !

_. . ___H_

r " . •

- &*•* 

## iffigs&^a ^

. i ^

, 4 » Surplu s Productio n

Increasin g Numbe ro f Adult s

Figur e 7-1 . Surplus productio n model .

TENER A E9-055. 0 7-2 5 Fina l 316(b ) Demonstratio n Marc h 1 , 200 0P.9 4



# Blan k Pag e

# I I I I I 1 I I I I I I I I I 1 I I I 8. 0 Conclusion s 

# 8. 0 Conclusio n Sectio n 316(b ) ofth e Federa l Wate r Pollutio n Contro l Ac t

Amendment s o f

197 2 (Clea n Wate r Act ) require s tha t

th e Diabl o Canyo n Powe r Plan t (DCPP ) coolin g wate r intak e structur e represent s th e bes t

technolog y availabl e (BTA ) t o minimiz e advers e environmenta l impact s (AEI) . A s discusse di n th e Introductio n o f thi s report , th e Unite d State s Environmenta l Protectio n Agenc y (USEPA ) ha s indicate dtha t assessmen t

o f AE I shoul d b e base d o n a n evaluatio n o f population-leve l effects . Th e result s ofth e assessment s o n th e 1 6 targe t tax aselecte d fo r

thi s DCP P 316(b ) stud y b y th e Entrainmen t Technica l Wor k

Grou p (ETWG ) sho w n o populatio n leve l effect s du e t o entrainmen t an d impingement . Consequently , w e conclud e tha t th e DCP P intak e structur e i s no t

causin g AEI . Sinc e DCP P i s no t

causin g population-leve l effects , n o consideratio n o f alternativ e coolin g wate r intak e structur e technologie s fo r minimizin g AE I i s necessary . However , thi s repor t doe s includ e a n assessmen t

o f alternativ e technologie s i n respons e t o arequiremen t b y th e Centra l Coas t RWQCB . Th e conclusio n o f thi s alternativ e technologie s assessmen t i s tha t th e existin g coolin g wate r intak e structur e i s th e bes t technolog y availabl e fo r DCPP . 

### Summar y o f Effect s

• Population s ofth e fiv e targe t tax awit h pelagi c egg s (Pacifi c sardine , norther n anchovy , whit e croaker , sanddabs , an d Californi ahalibut ) ar e no t adversel y impacte d b y th e DCP P intak e indicate d b y generall y lo w t o moderat e estimate s o f P KI , FH , o r AEL. Furthermore , thes e tax aar e protecte d agains t localize d effect s b y havin g *>>-„, / - '•-'•• *

_________— . —• ,.',. , *~ widespread^opulation s o r spawnin g center s distan t fro mDCPP . I n th e cas e o f ,.,. , v ^,-,, . Californi ahalibut , wit h arelativel y hig h P KI , bu t lo w approximate d FH, ver y fe w • "•"'

, !.- ,s <r. K

S ' individual s ar e entraine da t DCP P s o ther e i s n o advers e impac t o n thei r population . ... . iY

• Bot h group s o f

rockfishe s (KG B an d blu e rockfis h complexes ) ha d lo w number s o f estimate dadul t

equivalen t

losse s t o thei r

populations . Cabezo n ha d lo w estimate d larva l mortalit y (<1%) , base d o n extrapolation s usin g th e alongshor e an d onshor e currents . Thi s stud y als o estimate d tha t th e larva l mortalit y o f painte d greenlin g wa s generall y belo w 1% , usin g simila r extrapolations . I n addition , brow n roc k cra b an d TENER A E9-055. 0 8- 1 Fina l 316(b ) Demonstratio n Marc h 1.200 0P.9 6 8. 0 Conclusion s slende r cra b ha dlo w estimate d larva

l mortality . Al

l o f thes e specie s hav e population s tha t ar e distribute dwell beyond th e zon e o f influenc e o f

DCPP .

• The remainin g tax a(smoothhea d sculpin , snubnos e sculpin , monkeyfac e prickleback , clini dkelpfishes , an

dblackey e goby ) ha

d larva l mortalitie s tha

t exceede d 10 % i

n referenc e t o tha

t par t ofth e populatio n livin g i

n a n are a2- 8 time s th e stud

y grid area . However , th e are aaffectedi s only par t o f thes e species ' geographi c range . Therefore , thes e effect s appea r t o localize d and d o no t

constitute population-leve l effects .

• Ofthe five tax awit

h relativel y hig

h estimate d larva

l mortalities , only tw o ha

d corroboratin g evidenc e tha t loca l adult an d juvenil e abundanc e coul d b e affected b y th e DCP P coolin g wate

r intak e system : clini d kelpfishe s an d snubnos e sculpin . Bot

h subtida l observation s o f

adult s an d long ter mplankto n samplin g o f

larva e showed declinin g number s ove

r recen t year s i n th e vicinit

y o f DCPP . I t i s importan

t t o not e tha t th e corroboratin g evidenc e noted abov e fo r clini d kelpfishe s an

d snubnos e sculpin i s basedo n limite d samplin g a

t one loca l subtida l samplin g transec t

fou r time s pe r yea r (a s visibilit

y permits ) an

dweekly plankto n tow s a

t th e mout h ofth e Intak

e Cove . Additionally , there i s som

e evidenc e i

n souther n Californi a(Holbrook

et al . 1996) tha

t th e effect s o f aregim e shif t i n th e Californi aCurren

t toward s warme

r wate r temperature s combined wit h successiv e E

l Nin o event s hav e continue d to caus e genera l populatio n decline s i

n mor e northerly distribute dspecie s (e.g. , rockfishes) . I t shoul d als o b e note d tha

t th e ETM methodolog y wa s originall y develope dan

dadapte dfo

r specie s wit

h larva e disperse d throughout

th e stud y grid are a an dnot fo r nearshor e species . Clini d kelpfishe s an d snubnos e sculpin ar

e nearshor e fishe s an d thu s wer e undersample db

y th e stud y gri d methodology . Bot

h kelpfishe s an

d snubnos e sculpin (a s wel l a s the othe

r nearshor e species ) ar

e foun d i n thes e inshor

e areas , an d thu s their

larva l mortalit y estimate s coul db e overestimated . Th e effect s ofth e coolin g wate r intak e structur e estimate d b

y th e AEL an d FH model s di d not include th e ver

y small losse s du e to impingement . Whe n added to the AEL

an d FH estimates , thes e losse s do not

chang e th e overal l conclusio n tha t entrainment

effect s ofth e plant' s coolin g wate r intak e syste md o not constitut e AE I fo r population s ofth e 1 6 targe t tax afo r which assessment s wer

e made . TENER A E9-055. 0 8- 2 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.9 7 

# I I I I I I I I I I I I 8. 0 Conclusion s

Using criteri asuppliedb

y th e USEP

A (1977 ) fo

r determinin g th e exten

t o f AE I an d supplemente db

y criteri aspecifi c to th e presen t 316(b ) stud

y a t DCPP , estimate s of

entrainmen

t effect s o n the population s ofth e 1 6 target tax apresente d i

n thi s repor

t do not constitut e AEI . Fo r tw o ofth e nearshor

e tax aassesse d (clini d kelpfishe s an d snubnos e sculpin ) ther

e i s som e evidenc e o f

loca l decrease s i

n bot h larva l an d adult abundanc e whic

h ma y b e attributabl e to entrainmen

t of early lif e stage s i n th e DCP P coolin g wate

r intak e system . However , climatologica

l an doceanographi c condition s (e.g. , regim e shifts , E l Nin o events ) ma

y have contribute dt

o thes e loca

l decline s t o a

n unknow n exten t an d should b e considered . 

### Alternativ e Technologie s Alternative s t o th e curren

t coolin g wate

r syste mevaluate d fo

r DCP P included seasona

l refueling outages ; reduction i

n annua l operation ; modification s t o th e travelin g screens ; sluiceway s an d thei r operation ; expansio n ofth e existin g shorelin e intak e structur e an d installatio n o f

modifie d screening ; an

dreduction s i

n coolin g wate

r flo w rates . I n addition , consideratio n wa s give n to transferrin g th e ocea

n hea t sink , open-cycl e coolin g proces s t o land-base d closed-cycl e coolin g towers . Eac

h altemativ e i s expecte d t o offe r som e potentia l fo r reducin g th e losse s of

organism s resultin g fro

mentrainmen

t o r impingement . The judgment

ofth e bes t

technolog y availabl e fo

r the Diabl o Canyon Powe

r Plan t i s base do n a consideratio n ofth e leve

l o f impact caused b y entrainmen

t an d impingemen

t o n th e marine community , demonstrate doperatio n an d reliabilit y of variou s alternativ e technologies , an dthe biologica l effectivenes s o f

thes e technologie s fo

r furthe r reducing entrainmen

t an d impingement , engineerin g an

doperationa

l feasibility , an

d cos t effectivenes s ofth e alternativ e technologies . Base do n th e evaluatio n o f

alternativ e intak

e technologie s fo

r DCP P i t wa s concluded that :

• Ther e i s no reasonabl e alternativ e intak e location tha

t would reduc e entrainmen

t an d impingemen

t losses .

• Behaviora

l barrier s would no

t reduc e the number s offis h exposed to impingemen t or entrainment .

• Medi afilters , barrie

r nets , an d Gunderboomwer

e determine d t o b e not

applicabl e a

t the DCP P sit e due to th e larg e flo

w volumes , hig

h debri s loading , an

d potentia l fo r roug h ocea n conditions . TENERA E9-055. 0 8- 3 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.9 8 8. 0 Conclusion s

• Incline d screens , dru mscreens , an d centerflo w screen s with fin e mesh , woul d no t significantl y reduc e impingemen t losse s an d hav e no t

bee n prove n t o substantiall y reduc e entrainmen t

losses .

• Modification s t o th e intak e screen s an d th e addition o f afis h retur n syste mcoul d reduc e th e losse s du e t o impingement . Becaus e ofth e lo w number s offis h impinge d o n existin g intak e screen s an d th e relativel y hig h cost s involved , installatio n o f modifie d intak e screen s i s disproportionat e t o th e benefit .

• Expansio n ofth e intak e structur e t o achiev e alowe r approac h velocit y o r

t o provid e a n angle dscree n intak e coul d reduc e impingement . Th e cos t o f modification , however , i s disproportionat e t o th e benefit s o f reduce d impingement .

• Variabl e spee d pum p drive s coul d b e provide d t o allo w reduction s i n circulatin g wate r flo w t o minimum s require d fo r plan t operation . Th e desig n margin s ofth e condense r

syste ma t

DCP P coul d allo w a2 t o 1 0 % reductio n i n circulatin g flo w whe n ambien t

seawate r temperature s ar e belo w 14. 4 ° C withou t exceedin g discharg e temperatur e limits . Th e hig h cost , uncertai n reliability , an d lo w biologica l benefi t mak e thi s optio n impractical .

• Seasona l pattern s wer e detecte d fo r entraine d larva l fishe s an d som e benefi t ha s occurre dwhe n coolin g wate r pump s ar e shu t

dow n for refuelin g an d maintenanc e outage s in sprin g an d fall . Fewe r larva l fishe s woul d b e susceptibl e t o entrainmen t i f al l outage s wer e schedule dfo r th e spring . However , schedulin g outage s t o coincid e with th e seasona l distributio n in abundanc e o f aparticula r

fis h o r grou p o f fishe s i s no t economicall y feasible , du e t o th e characteristic s ofth e nuclea r fuel .

• Consideratio n wa s give n t o curtailin g powe r plan t operatio n durin g sprin g month s whe n densit y offis h larva e wa s highest . In th e curren t pricin g structur e practic e for electrica l production , th e losse s associate d wit h nin e mont

h operatio n window s mak e thi s scenari o no t

economicall y feasible . Replacemen t powe r fro mgas-fire d facilitie s woul d als o hav e anegativ e contributio n t o ai r qualit y becaus e ofth e releas e o f emission s tha t

ar e no t generate d b y nuclea r

facilities .

• Closed-cycl e coolin g tower s wer e evaluate d t o reduc e entrainmen t an d impingemen t losses . Coolin g tower s usin g saltwate r woul d impac t

th e lan d an d biot awith thei r TENER A E9-055. 0 8- 4 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.9 9 8. 0 Conclusion s larg e "foot-print, " corrosiv e fogs , vapo r plumes , an

d salt drift . Ther

e i s n o resourc e larg e enoug

h t o provide freshwate

r makeu p fo r coolin g towers , an

d th e additio n o f

a seawate r desalinatio n plan

t of sufficien t capacit y would ad

d considerably t o project costs . Th e cost s t o retrofi t

closed-loop coolin g tower s t o DCPP , which woul d requir e substantia l construction , refitting , an

d redesig n ofth e plant , would not b e viabl e i

n th e current

or futur e powe r generatio n market .

TENER A E9-055. 0 8- 5 Fina l 316(b ) Demonstratio n Marc h 1,200 0P.10 0



# Blan k Pag e