PSEG Comments on Proposed 316(b) Rule Appendix A—August 18, 2011

A-22 

### Attachment C

Excerpt from

Salem Generating Station

NJPDES Permit No. NJ0005622

Response to NJPDES Permit Special Conditions G.9:

INTEGRATED FINDINGS REPORT

Attachment 9: Special Study Report

Salem Generating Station

Estimated Latent Impingement Mortality Rates:

Updated Pooled Estimates Using Data from

1995, 1997, 1998, 1999, 2000 and 2003

PSEG Nuclear LLC

Estuary Enhancement Program

November 2004

### Special Study Report

Salem Generating Station

Estimated Latent Impingement Mortality Rates: Updated Pooled Estimates Using Data from 1995, 1997, 1998, 1999, 2000 and 2003

Prepared for

PSEG Services Corp.

Prepared by

AKRF 7250 Parkway Drive, Suite 210
Hanover, MD 21076

June 18, 20041 I. INTRODUCTION

This report contains updated estimates of latent impingement mortality (“LIM”)

rates for the new intake screens at Salem Gene rating Station (“Station”). These LIM rate estimates update the LIM rate estimates pr esented in Appendix L of PSEG’s March 1999 Permit Renewal Application for Salem Genera ting Station (“1999 App lication”), and the LIM rate estimates presented in the Public Service Enterprise Group report entitled “Special Study Report, Salem Generating St ation. Estimated Latent Impingement Mortality Rates: Updated Pooled Estimates Using 1995, 1997, 1998, 1999, and 2000 Data” (prepared by PBS&J, Beltsville, MD, June 2001). The current updates include data on fish examined in LIM studies in 2003, as well as those examined in LIM studies in 1995, 1997, 1998, 1999 and 2000.

II. METHODS

A. Pooled Estimates of LIM Rates

The updated estimates of LIM rates we re computed using the methods for calculating pooled LIM rate estimates that ar e described in Appendix F, Attachment F-2 of the 1999 Application. The pooled estimates of LIM rates for the new intake screens were based on fish collected during two-un it combined sluice operation only. For each species, estimates were computed for months in which at least 30 fish (initially alive) were examined for latent impingement mortality. With 30 fish, the 95% confidence

interval for an estimated LIM rate of 0.5 is roughly 0.3 to 0.7; the 95% confidence

interval for an estimated LIM rate of 0.0 is roughly 0.0 to 0.1; and the 95% confidence

interval for an estimated LIM ra te of 1.0 is roughly 0.9 to 1.0.

B. Predicted LIM Rates from Logistic Regression Analysis

For months in which fewer than 30 fish of a species were examined for latent impingement mortality, a predicted latent im pingement mortality rate was calculated based on the average water temperature and salinity, and the aver age length of fish impinged during the month. The relationship be tween latent impingement mortality rate and the predictor variables (i .e., water temperature, sali nity and fish length) was characterized with a logistic regression model. The logistic regression model gives equal weight to each fish examined in the LIM studie s. The logistic regres sion analysis used all of the data (with reported temperature, salin ity and fish length) from latent impingement mortality studies that were used to compute the pooled LIM rate estimates.

The following logistic regression model wa s used to characterize the relationship between latent impingement mortality rate and the predictor variables:



# ∑

= + = 5

1 , 0 ) ( logit

i k i i k X p β β2 where

⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛

− =

k k
k p p p 1 ln ) ( logit

and

k p = probability of latent impingement mortality during experiment k

0 β = intercept term of the logistic regression model

i β = coefficient of term i in the logistic regression model

X

i,k = value of variable X i (see list below) based on the temperature, salinity and average length of fish in experiment k

X

1 = average length of fish

X

2 = temperature

X

3 = salinity

X

4 = ( X

2,k ) × ( X

1,k ) temperature-length interaction

X

5 = ( X

3,k ) × ( X

1,k ) salinity-length interaction

Variables X 4 and X 5 are interaction variables that allow the effects on the latent impingement mortality rate of temperature and salinity to vary depending on the length of the fish. A preliminary analysis indicated that additional terms (e.g., quadratic terms) would not materially improve the predictive ab ility of the model. A stepwise procedure was used which only retained terms in the model that were statistically significant (pr=0.001) for explaining variability in latent impingement mortality rates.

The predicted latent impingement mortality rate in each month was calculated as

follows:

m Y m e p

ˆ 1 1

~

− + =

where 

# ∑

= + = 5

1 , 0 ˆ ˆ ˆ

i i m i m X Y β β

and

m p ~ = predicted latent impingement mortality rate in month m

i m X

, = the value of variable X i based on the average historical (1977- 2001) temperature, salinity and impinged fish length during

month m

i β ˆ = maximum likelihood estimate of the coefficient for term i of the logistic regression model

The variance of each predicted value wa s estimated using the Taylor series approximation (Kendall, M. and A. Stuart, 1977):3 

# ( ) ( )

m Y Y

m Y

e e p

m m ˆ r a ˆ v 1 ) ~ r( a ˆ v 2

2

ˆ ˆ

⎥ ⎥ ⎦ ⎤

⎢ ⎢ ⎣ ⎡

+ =

− −

where 

# ( ) 

# ( ) ∑∑

= = = 5

0 5

0 , , ˆ

, ˆ v o ˆ c ˆ r a ˆ v

i j j i j m i m m X X Y β β

and 

# ( )

j i β β ˆ

, ˆ v o ˆ c = estimated covariance between
i β ˆ and j β ˆ (from the logistic

regression)

X

m,0 = 1 for all months m

The approximate 95% confidence limits for th e predicted latent impingement mortality

rate in month m were computed as: 

# ( ) ) ˆ r( a ˆ v 96

. 1 ~

m

m p p × ±

C. Confidence Limits for Pooled LIM Rate Estimates

For the purpose of comparing monthly pr edicted values of latent impingement mortality rates (from the logistic regressi on analysis) to pooled monthly estimates of latent impingement mortality rates, confid ence limits were calculated for the pooled

estimates. Confidence limits were calculate d based on the binomial distribution (Beyer, W.H., 1966). For upper confidence limits, the following equation was solved for UCL ρ :



## ( ) α ρ ρ =

− ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ 

## ∑

= − r

x x n

UCL x
UCL x n

0 1

and for lower confidence limits, the following equation was solved for LCL ρ :



## ( ) α ρ ρ =

− ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ 

# ∑

= − n

r x x n

LCL x
LCL x n 1

where

LCL ρ = lower confidence limit for the pooled monthly estimate of the

LIM rate

UCL ρ = upper confidence limit for the pooled monthly estimate of the

LIM rate

n = total number of fish on which th e pooled monthly estimate of the

LIM rate was based4 r = total number of fish (out of n ) that did not survive the LIM experiment

α = probability level for the confidence limits (for 95% confidence limits, α = 0.025)5 III. RESULTS

Estimates of monthly LIM rates ba sed on the pooled estimation method are presented in Table 1. Also presented in Table 1 are predicted LIM rates (from the logistic regression analysis) for months in which fewer than 30 fish of a taxon were examined in the LIM studies. Numbers of fish examined in the LIM studies, by taxon and month, are listed in Table 2. Number s of fish examined in the LIM studies and included in the logistic regres sion analysis (i.e., fish for which length, temperature and salinity were reported) are listed in Table 3.

Monthly predicted LIM rates with 95% conf idence limits are presented in Figures 1 through 7. For comparison, these figures al so depict monthly estimates of LIM rates with 95% confidence limits from the pooled estimation method. These graphs depict monthly LIM rate estimates (based on the pool ed estimation method) for all months that provided any fish that were included in the logi stic regression analysis, not just months in

which at least 30 fish were examined. For the purpose of comparing predicted (from the logistic regression) LIM rates to estima ted (from the pooled estimation method) LIM rates, the estimated LIM rates were computed using only fish included in the logistic regression analysis (i.e., fish for which length, temperatur e and salinity were reported).

Estimated coefficients for the logistic regression model are listed in Table 4.

The logistic regression analysis was not conducted for blue crab because blue crab were only collected for LIM st udies during two days in Se ptember 1998, and temperature was not reported in the data. All hogchoke r examined during LIM studies survived, and therefore a logistic regression anal ysis was not conducted for hogchoker.

IV. LITERATURE CITED

Beyer, W.H. (ed.) 1966. CRC Handbook of Tables for Probability and Statistics. The Chemical Rubber Co. Cleveland, OH.

Kendall, M. and A. Stuart. 1977. The Advanced Theory of Statistics. Vol. 1. Macmillan Publishing Co., Inc. New York, NY.6Table 1. Monthly latent impingement mortality rate estimates for two-unit, combinedsluice operation with the new intake screensystem based on the pooled estimation method(shaded cells) and based on the logistic regression analysis. These estimates arebased on data collected from 1995 through 2003. Estimates for Alosids are for American shad, alewife and blueback herringcombined. Predicted latent impingement mortality rates for weakfish could not be computed for January and February becauseno weakfish were reported in impingement collections in thosemonths. Consequently, the average length of impinged fish (avariable required for the logistic regression analysis) in thosemonths could not be computed.The logistic regression analysiswas not conducted for blue crab orhogchoker due to data limitations.TAXONJAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DECAlosids0.081 0.083 0.1390.2090.512 0.715 0.808 0.813 0.7250.5380.2940.131Atlantic Croaker0.2040.217 0.2180.4330.3020.2820.1060.377 0.1570.0190.0130.076Bay Anchovy0.022 0.024 0.0620.4650.4910.7160.9070.9630.9470.2230.2700.046Spot0.233 0.279 0.450 0.749 0.611 0.469 0.252 0.135 0.090 0.0830.0450.220Striped Bass0.000 0.000 0.001 0.002 0.002 0.0130.3390.1320.1900.0200.0000.011Weakfish. . 0.033 0.147 0.0350.5590.6390.5380.1860.1910.009 0.009White Perch0.0630.007 0.0120.0430.3180.2350.3400.1250.0590.0360.0270.018Blue Crab0.023Hogchoker0.0000.0000.0007Table 2. Total number of fish examined in latent impingementmortality studies (by taxon and month) during two-unit, combinedsluice operation of the new intake screen system.TAXONJAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DECAlosids11 43 7 2 11 20 39 136 21Atlantic Croaker452 180 706 708 47 5 23 212 304 728Bay Anchovy1 303 212 162 43 54 57 260 141 2Spot3 4 22 89 5Striped Bass5 6 1 23 280 317 105 196 53 90Weakfish1239 2439 2170 349 47White Perch32 16 115 44 22 191 551 101 895 1529 1342Blue Crab43Hogchoker120 211 79 158Table 3. Total number of fish examined in latent impingementmortality studies (by taxon and month) during two-unit, combinedsluice operation of the new intake screen system. This table only lists fish from studies in which fish length, water temperatureand salinity were reported, and therefore wereincluded in the logistic regression analysis.TAXONJAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DECAlosids11 43 7 2 11 20 39 127 20Atlantic Croaker434 180 698 696 44 5 23 212 268 728Bay Anchovy1 302 212 151 42 51 57 259 95 2Spot3 4 22 58 5Striped Bass5 6 1 22 280 317 105 196 48 90Weakfish1015 2285 2073 349 47White Perch32 16 115 41 22 191 551 101 895 1363 13429Table 4. Estimated coefficient values from the logistic regression analysis. Missing values indicate the term in the logisticregressionmodel was not statistically significant.TAXON0ˆ β(Intercept)1ˆ β(Length)2ˆ β(Temperature)3ˆ β(Salinity)4ˆ β(TemperatureLengthInteraction)5ˆ β(SalinityLengthInteraction)Alosids-3.0011 . 0.1710 . . .Atlantic Croaker-0.7680 . . -0.1774 . 0.0015Bay Anchovy-4.0239 . 0.2684 . . -0.0017Spot3.8315 . . -0.6959 . .Striped Bass1.3428 -0.1154 . . 0.0022 .Weakfish-1.9848 . 0.1243 . . -0.0036White Perch-5.6016 . 0.1100 . 0.0007 .10 Figure 1. Monthly estimates of latent im pingement mortality rates for Alosids (i.e., American shad, alewife and blueback herri ng). Estimates of latent impingement mortality rate based on the pooled estim ation method (orange dots) with 95% confidence intervals (orange bars), and predicted latent impingement mortality rates based on the logistic regression an alysis (green dots) with 95% confidence intervals (green bars). Ha tched orange bars indicate months in which fewer than 30 fish were examined during the impingeme nt mortality rate studies. The pooled estimates in this figure only include fish from studies in which fish length, water temperature and salinity were reported (i .e., the fish included in the logistic regression analysis). 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

1 Alosids

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecLatent Impingement Mortality Rate11 Figure 2. Monthly estimates of latent impinge ment mortality rates for Atlantic croaker. Estimates of latent impingement mortal ity rate based on the pooled estimation method (orange dots) with 95% confidence intervals (orange bars), and predicted latent impingement mortality rates based on the logistic regression analysis (green dots) with 95% confidence intervals (green bars). Hatched orange bars indicate

months in which fewer than 30 fish were examined during the impingement mortality rate studies. The pooled estimates in this figure only include fish from studies in which fish length, water temper ature and salinity were reported (i.e., the fish included in the logis tic regression analysis). 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

1 Atlantic Croaker

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecLatent Impingement Mortality Rate12 Figure 3. Monthly estimates of latent im pingement mortality rates for bay anchovy. Estimates of latent impingement mortal ity rate based on the pooled estimation method (orange dots) with 95% confidence intervals (orange bars), and predicted latent impingement mortality rates based on the logistic regression analysis (green dots) with 95% confidence intervals (green bars). Hatched orange bars indicate

months in which fewer than 30 fish were examined during the impingement mortality rate studies. The pooled estimates in this figure only include fish from studies in which fish length, water temper ature and salinity were reported (i.e., the fish included in the logis tic regression analysis). 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

1 Bay Anchovy

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecLatent Impingement Mortality Rate13 Figure 4. Monthly estimates of latent impinge ment mortality rates for spot. Estimates of latent impingement mortality rate base d on the pooled estimation method (orange dots) with 95% confidence intervals (o range bars), and predicted latent impingement mortality rates based on the lo gistic regression analysis (green dots) with 95% confidence intervals (green bars). Hatched orange bars indicate months

in which fewer than 30 fish were examin ed during the impingement mortality rate studies. The pooled estimates in this fi gure only include fish from studies in which fish length, water temperature and salinity were reported (i.e., the fish included in the logistic regression analysis). 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

1 Spot

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecLatent Impingement Mortality Rate14 Figure 5. Monthly estimates of latent impingement mortality rates for striped bass. Estimates of latent impingement mortal ity rate based on the pooled estimation method (orange dots) with 95% confidence intervals (orange bars), and predicted latent impingement mortality rates based on the logistic regression analysis (green dots) with 95% confidence intervals (green bars). Hatched orange bars indicate

months in which fewer than 30 fish were examined during the impingement mortality rate studies. The pooled estimates in this figure only include fish from studies in which fish length, water temper ature and salinity were reported (i.e., the fish included in the logis tic regression analysis). 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

1 Striped Bass

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecLatent Impingement Mortality Rate15 Figure 6. Monthly estimates of latent im pingement mortality rates for weakfish. Estimates of latent impingement mortal ity rate based on the pooled estimation method (orange dots) with 95% confidence intervals (orange bars), and predicted latent impingement mortality rates based on the logistic regression analysis (green dots) with 95% confidence intervals (green bars). Predicted latent impingement mortality rates for weakfish could not be computed for January and February because no weakfish were reported in im pingement collections in those months. Consequently, the average length of impi nged fish (a variable required for the logistic regression analysis) in those m onths could not be computed. The pooled estimates in this figure only include fish from studies in which fish length, water temperature and salinity were reported (i .e., the fish included in the logistic regression analysis). 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

1 Weakfish

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecLatent Impingement Mortality Rate16 Figure 7. Monthly estimates of latent impi ngement mortality rates for white perch. Estimates of latent impingement mortal ity rate based on the pooled estimation method (orange dots) with 95% confidence intervals (orange bars), and predicted latent impingement mortality rates based on the logistic regression analysis (green dots) with 95% confidence intervals (green bars). Hatched orange bars indicate

months in which fewer than 30 fish were examined during the impingement mortality rate studies. The pooled estimates in this figure only include fish from studies in which fish length, water temper ature and salinity were reported (i.e., the fish included in the logis tic regression analysis). 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

1 White Perch

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecLatent Impingement Mortality Rate