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-- 

NUREG/CR -2220 

Volume 11 

ORNt/NUREG/TM-385/V2

Distribution Category-RE 

-. Contract No. W-7405-eng-26 

THE IMPACT OF ENTRAINMENT AND IMPINGEMENT ON 

FISH POPULATIONS IN THE HUDSON RIVER ESTUARY 

VOLUME 11 

' Impingement Impact Ana.lyses, Evaluations of Aqternative Screening

-Devices, and Critiques of Utility Testimony Relating tu DensityDependent Growth, the Age-Composition of the Striped Bass .. Spawning Stock, and the LMS Real-Time Life Cycle Model 

1. W, Barnthouse, W. Van Idjnkle, 3. Golumbek,l G. F. Cada, 

C. P. Goodyear,2 S. ki. Christensen, J. 8. Cannon,3 and 0, bl. Lee3 

ENVIRONMENTAL SCIENCES DIVISION 

Publication No. 1791 

lEnergy and Thermal Wastes Section; Water Division, U.S. Environmental 

Protection Agency, Region 11, New York 10278. 

ZNationa? Fisheries Center -- Leetown, U.S. Fish and Wildlife 

Service, Route 3, P.O. Box 41, Kearneysville, West Virginia 25430. 

3Energy Divi sian, Oak Ridge National Laboratory. 

Manuscript Completed - September 1981 

Date Published - April 1982 

Prepared for 

Office of Nuclear Regulatory Research 

U.S. Nuclear Regulatory Commission 

Washington, D.C 20555 

-,)der Interagency Agreement No. DOE 40-550-75 

MRC FIM 80165 

TASK: Methods to Assess Impacts on Hudson River Striped Bass 

OAK RIDGE NATIONAL LABORATORY 

Oak Ridge, Tennessee 37830 

operated by

UNION CARBIDE CORPORATION 

for the. 

DEPARTMENT OF ENERGY 

REPRODUCED BY 

US. DEPARTNlENTOF COMMERCE 

NATIONALTECHNICAL 

1NFORMATIOIdSERVICE 

SPRINGFIELD, YA 22161 
-- 

335 US. NUCLEAR REGULATORY COMMISSION 1. REPORT NUMCER IAsngneaby DDCI 

NUREG/CR-2220, YO^. I1 

BlBLlOGRAPHfC DATA SHEET ORNL/NUREG/TM-385/V2 

AND SUBTITLE [Add Vafurne No.. sf wprwrtarel 2. Leave blsnk) 

P

ULATIONS IN THE HUDSON RIYER ESTUARY 3. RECIPIENTS ACCESSION NO. 

'THOR 4sJ 5. DATE REPORT COMPLETED

d. Barnthouse, W. Van Winkle, J. Golurnbek, G.F. Cada, MONTH YEAR

Goodyear, S.W. Christensen, J.B. Cannon, D.M. Lee March 1982 

RMlNG ORGANIZATION NAME AND MAlllNG ADDRESS Ilnclude Zro Code) DATE REPORT ISSUED 

Oak Ridge National Laboratory MONTH May YEAR 1982 Oak Ridge, TN 37830 

6 Leave blanki 

8. (Leave blank I 

I 

'WSORlNG ORGANIZATNON NAME AND MAILING ADDRESS ilnclude ZJP Coaeef 

10 PR0JECT:TASKIWORK UNIT NO.

U.S. Nuclear Regulatory Commission 

Office of Nuclear Regulatory Research 1 Washington, DC 20555 FIN No. BO165 

PE AI00 COVE RED Nnclustve dares1 I OF 

I 

PPLEMENTARY NOTES 1 4 1Leave ddn I I 

RACT (200 words or teul 

i

urpose of this three-volume report is to publish the individual pieces of testiinvolving ORNL staff in a three-year adjudicatory hearing on the effects of 

ric power generation on the Hudson River. Volume I1 contains four exhibits reing to impingement impacts and three critiques of certain aspects of the utilities' 

The first exhibit is a quantitative evaluation of four sources of bias (colIon efficiency, reimpingejnent, impingement on inoperative screens, and impinget survival) affecting estimates of the number of fish killed at Hudson River power 

S. The following two contain, respectively, a detailed assessment of the impact

pingement on the Hudson River white perch population and estimates of conditional 

mortality rates for seven Hudson River fish populations. The fourth exit is an evaluation of the engineering feasibility qnd potential biological effectss of several: types of modified intake struttures proposed as alternatives t o 1ng towers for reducing Impingement impacts. This volume' also consists of critical 

luations of the utilities' empirical evidence for the existence of density-dependent

rowth in young-of-the-year striped bass and white perch, the estimate of age-comion of striped bass spawning stock in the Hudson River, and their use of the Lawler,

isky, and Ske'lly (ttjS) Real-Time Life Cycle Model to estimate the impact of entrainand impingement on the Hudson River striped bass population. 

ORDS AND DOCUMENT ANALYSIS 1 ?a DESCRIPTORS 

cTIFJEAS;OPEN-ENDED TERMS 

ASlLlTY STATEMENT repom 21 NO.OF PAGES 

Unl imi ted 20 SECURITY CLAsS (This oaw, 22 PRICE 

Unclassi f I ed S 
I ACKNOWLEDGEMENTS 

I 

The authors thank S. M. Adarns, J. Boreman, T. Fikslin,

S. G. Hildebrand, J. M. Loar, and D. S. Vaughan for their critical 

reviews of this work. We also thank the Environmental Sciences 

Division Word Processing Center for the editing and make-up needed to 

combine seven pieces of testimony into one technical report. 

1 

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1 

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1 

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iii 
FOREWORD 

On December 19, 1980,with the signing of an out-of-court 

settlement agreement, a three-year adjudicatory hearing on the effects 

of electric power geileration on the Hudson River was ended. The 

purpose of this hearing had been to determine whether six cooling 

towers, required by the various Environmental Protection Agency (EPA)

permits, should be built at three power plants on the Hudson River in 

New York .in order to mitigate the impacts of entrainment and 

impingement on estuarine fish populations. In addition to terminating

the �PA hearings, the settlement resolved regulatory disputes between 

the utility companies and several other federal agencies, including the 

U.S. Nuclear Regulatory Commission (NRC). 

Staff of the Environmental Sciences Division at Oak Ridge National 

Laboratory (ORNL) were asked to participate in the EPA hearings because 

of previous work on entrainment and impingement performed for AEC, NRC,

ERDA, and DOE in connection with the licensing of Indian Point Units 2 

and 3, the largest generating units on the Hudson River. ORNL Staff 

prepared and submitted, in May '8979, numerous individual pieces of 

written direct testimony for EPA as part of these hearings. Some of 

these pieces of testimony were coauthored with individuals from the 

National Power P1ant.Team of the U. S. Fish and Wildlife Service and. 

from EPA. The purpose of this three-volume report is to publish these . - individual pi.eces of tes,timony inv.olv-ingWNL -st&ff in-a manner -that 

will assure a broader distribution to the scientific community,

government agencies, and other interested parties. 

Volume I is concerned with the estimation of the direct (or

annual) entrainment impact of the power plants on populations of 

striped bt3ss, white perch, Alosa spp. (blueback herring and alewife),

American shad, Atlantic tomcod, and bay anchovy in the Hudson River. 

Entrainment impact results from the killing of fish eggs, larvae, and 

young juvreniles that are contained in the cooling water cycled through 

a power plant. An "Empirical Transport Model" is presented as the 

means of obtaining a conditional entrainment mortality rate (which 

represents the fraction of a year class which would be killed due to 

entrainment in the absence of density-dependent mortality). Most of 

Volume I .is concerned with the estimation of several parameters

required Iby the model: physical input parameters (e.g., power-plant

withdrawal flow rates); the longitudinal distribution of 

ichthyoplankton in time and space; the duration of susceptibility of 

the vulnerable organisms;-the "W-factors," which express the ratios of 

densities of organisms in power plant intakes to densities in the 

river; and the entrainment mortality factors, which express the - probability that an organism will be killed if it is entrained. Once 

these values are obtained, the model is used to estimate entrainment 

impact for both historical conditions and projected conditions. 

Preceding page.-Mank v 
Volume I1 contains four exhibits relating to impingement impacts

and three critiques of certain aspects of the utilities' case. The 

first exhibit is a quantitative evaluation of four sources of bias 

(co: lection efficiency, reimpingement, impingement on inoperative 

screens, and impingement survival) affecting estimates of the number of 

fish killed at Hudson River power plants. The two following exhibits 

contain, respectively, a detailed assessment of the impact of 

impingement on the Hudson River white perch population and estimates of 

conditional impingement mortality rates for seven Hudson River fish 

populations. The fourth exhibit is an evaluation of the engineering

feasibility and potential biological effectiveness of several types of 

modified intake structures proposed as alternatives to cooling towers 

for reducing impingement impacts. The remainder of Volume II consists 

of critical evaluations of the utilities' empirical evidence for the 

existence of density-dependent growth in young-of-the-year striped bass 

and white perch, of their estimate of the age-composition of the 

striped bass spawning stock in the ffudson River, and of their use of 

the Lawler, Matusky, and Skelly (LMS) Real-Time Life Cycle Model to 

estimate the impact of entrainment and impingement on the Hudson River 

striped bass population. 

Volume I11 addresses the validity of the utilities' use of the 

Ricker stock-recruitment model to extrapolate the combined . 

entrainment-impingement losses of young fish to reductions in the 

equilibrium population size of adult fish. In our testimony, a 

methodology was developed and applied to address a single fundamental 

question: if the Ricker model really did apply to the Hudson River 

striped bass population, could the utilities' estimates, based on 

curve-fitting, of the parameter alpha (which'controls the impact) be 

considered reliable? The present Volume 111 includes, in addition, an 

analysis of the efficacy of an alternative means of estimating alpha,

termed the technique of prior estimation of beta (used by the utilities 

in a report prepared for regulatory hearings on the Cornwall Pumped

Storage Project). Our validaticn methodology should also be useful in 

evaluating inferences drawn in the literature from fits of 

stock-recruitment models to data obtained from other fish stocks. 

_­

vi 
ABSTRACT 

BARNTHOUSE, L. W., W. VAN WINKLE, J. GOLUMBEK, G. F. CADA,

C. P. GOODYEAR, S. W. CHRISTENSEN, 3. B. CANNON, and 

D. W. LEE. 1982. Impingement impact analyses,

evaluations of alternative screening devices, and 

critiques of Utility testimony relating to 

density-dependent growth, the age-composition of the 

striped bass spawning stock, and the LMS Real-Time Life 

Cycle Model. Volume 11. IN The Impact of Entrainment 

and Impingement on Fish Populations in the Hudson River 

Estuary. ORNL/NUREG/TM-385/VZ\ and NUREG/CR-2220. Oak 

Ridge National Laboratory, Oak Ridge, Tennessee. 

This volume includes a series of four exhibits relating to impacts

of impingement on fish populations, together with a collection of 

critical evaluations of testimony prepared for the uitlities by their 

consultants. The first exhibit is a quantitative evaluation of four 

sources of bias (collection efficiency, reimpingement, impingement on 

inoperative screens, and impingement survival) affecting estimates of 

the number of fish killed at Hudson River power plants. The two 

following (exhibits contain, respectively, a detailed assessment of the 

impact of impingement on the Hudson River white perch population and 

estimates (of conditional ,impingement mortality rates for seven Hudson 

River fish populations. The fourth exhibit is an evaluation of the 

engineering feasibility and potential biological effectiveness of 

several types of modified intake structures proposed as alternatives to 

cooling towers for reducing impingement impacts. The remainder of 

Volume I1 consists of critical evaluations of the utilities' empirical

evidence for the existence of density-dependent growth in 

young-of-the-year striped bass and white perch, of their estimate of 

the age-composition of the striped bass spawning stock in the Hudson 

River, and of their use of the Lawler, Matusky, and Skelly (LMS)

Real-Time Life Cycle Model to estimate the impact of entrainment and 

impingement on the Hudson River striped bass popu?ation. 

vi i 
I 

I 

8 SUMMARY 

The first four chapters in this volume relate to impacts of 

impingement on Hudson River fish populations. In Chapter I, the 

utilities' estimates of the numbers of fish impinged at the Bowline,

Lovett, Iridian Point, Roseton, and Danskammer generating stations are 

evaluated. The methods used to compute the number of fish killed by

impingement at each of these plants are described, and four sources of 

bias that can affect impingement estimates (collection efficiency,

reimpingement, impingement on inoperative travelling screens, and 

impingement survival) are discussed. Wherever possible, the magnitude

of each b.ias is estimated. Finally, plant and species-specific

adjustment factors that can be used to scale the impingement estimates 

up or down tolaccount for these biases are presented. 

Chapter I1 presents two independent lines of evidence evaluating

impingement losses of white perch at the power plants on the Hudson 

River. The first line of evidence involves analyzing the variation in 

collection rates among years over the period 1972-1977. These rates 

provide estimates of year-class strength on a relative scale. The 

second line of evidence involves estimating the conditional mortality 

rate (or equivalently, the percent reduction in year-class strength in 

the absence of compensation) due to impingement for the 1974 and 1975 

white perch year classes. 

Chapiter I11 presents estimates of conditional impingement

mortality rates for the 1974 year classes of white perch, striped bass,

alewife, blueback herring, American shad, and Atlantic tomcod, and for 

the 1975 year classes of white perch, striped bass, American shad, and 

the Atlantic tomcod. Exploitation rates for the total impingeable bay

anchovy population (adults + juveniles) residing above river mile 12 

are presented for each month from May through October 1974 and 1975. 

Rather than single "conservative" estimates of impact, realistic ranges

of probable impacts for each species and year class are developed. The 

highest impingement impact estimates obtained are for white perch, the 

lowest foir American shad. In addition to estimates of actual 

historical impacts, estimates of the impacts that would have occurred 

had closed-cycle cooling systems been installed at one or more of the 

three platits (Bowline, Indian Point, and Roseton) at issue in the 

hearings, are presented. It was found that greatly reduced impacts on 

white perch, Atlantic tomcod, and striped bass would have occurred had 

closed-cycle cooling systems been operating either at all three plants 

or only at Bowline and Indian Point. Closed-cycle cooling at Indian 

Point alone would have substantially reduced the impact of impingement 

on white perch and Atlantic tomcod, and would have moderately reduced 

the impact on striped bass. 

Chapter IV presents evaluations of the degree to which impingement

and entrainment mortality at the intake screenwells of Indian Point 

Units 2 and 3, Bowline, and Roseton, can be potentially reduced by 

Preceding page blank ix 
backfitting them with alternative screening devices. Both physical and 

behavioral screening barriers are considered. The physical screening

barriers considered are (1) conventional vertical traveling screens 

(VTS) with modifications, (2) center-flow traveling screens, 

(3) f lush-mounted horizontal traveling screens (HTS), (4)cylindrical

wedge-wire screens, and (5) radial well intakes. The behavorial 

screening barriers $onsidered are angled HTS and louver and angled 

screen diversion systems. It is concluded that there are alternative 

devices available that could potentially reduce impingement and, to a 

lesser extent, extrainment mortality at power plant cooling-water

intakes. The extent of reduction achievable in practice however, is 

site specific and can best be determined from in situ studies during

plant operation. 

Chapter W presents a critical evaluation of empirical "evidence" 

for the existence of density-dependent growth in the Hudson River 

striped bass and white perch populations. Consultants for the 

utilities have, on several occasions, reported finding inverse 

correlations between growth and abundance in juvenile striped bass and 

white perch, and have cited these results as evidence that 

density-dependent growth, a compensatory mechanism capable of partially

offsetting the impact of power plant entrainment and impingement, may

be operating in the ffudson River striped bass and white perch

populations. An evaluation of the data and methods of analysis used by

the utilities' consultants shows that it is not possible to demonstrate 

the existence or non-existence of density-dependent growth from 

existing data. It is further argued that, even if the existence of 

density-dependent growth could be proved, knowledge of its existence 

would be useless to the decision-maker because its compensatory effects 

cannot be quantified. 

Chapter VI presents a critical analysis of the utilities' estimate 

of the age-composition of the striped bass spawning stock in the Hudson 

River. Estimates of the contribution of each age-class to each year's

production are used by the utilities to develop lag times that 

determine the pairing of indices of stock and recruitment in their 

Ricker stock-recruitment curve-fitting exercise (Volume 111). The 

estimates of long-term power plant impact obtained from the 

curve-fitting exercise are highly sensitive to the choice of lag time. 

It is concluded that the utilities greatly underestimated the 

contribution of age seven and older striped bass to the spawning stock,

thereby underestimating the proper lag time for the stock-recruitment 

analysis. 

Chapter VI1 presents an evaluation of the utilities' use of the 

LMS Real-Time Life Cycle Model to estimate reductions in-year-class

abundance of striped bass caused by entrainment and impingement. It is 

concluded that the Real-Time Life Cycle Model is not a reliable tool 

for making sound fisheries management decisions. 

X 
TABLE OF CONTENTS 

Chapter Page 

FOREWORD.. .......................... V 

ABSTRACT.. .......................... vi i 

SUMMARY ............................ ix 1 

I An Analysis of Factors That.Inf1uence Impingement

Estimates at Hudson River Power Plants 

(L. W. Barnthouse) ................... 1-1 

I 11 Evaluation of Impingement Losses of White Perch 

at Hudson River Power Plants (W. Van Winkle and 

L. W. Barnthouse) .................... 11-1 

1 I I I Impingement Impact Estimates for Seven Hudson 

River Fish Species (L. #. Barnthouse and 

W. Van Winkle) ..................... 111-1 

I IV Alternative Screening Devices at Indian Point 

Units 2 and 3, Bowline Point, and Rosgton

Generating Stations (G. F. Cada, J. B. Cannon,

and D. W. Lee) ...................... IV-1 I 

V Density-Dependent Growth: A Critique of the 

i Utilities' "Empirical Evidence" (L. W. Barnthouse) . . e V-1 

VI A Critical Review of the Utilities' Age Composition

Analysis of the Hudson River Striped Bass Population

(3. Golumbek and S. W. Christensen) ........... VI-; a 

WII A Critical Evaluation of the Lawler, Matusky

and Skelly Two-Dimensional, Real-Time, Life-Cycle

Model of the Hudson River Striped Bass Population

(J. Golumbek, W. Van Winkle, and C. P. Goodyear) .... VII-1 

I 

I 

I 

I xi 

I 
CHAPTER I 

AN ANALYSIS OF FACTORS THAT INFLUENCE IMPINGEMENT ESTIMATES 

AT HUDSON RIVER POWER PLANTS 

TESTIMONY OF 

LAWRENCE W. BARNTHOUSE, Pb.D. 

ENVIRONMENTAL SCIENCES DIVISION 

OAK RIDGE NATIONAL LABORATORY 

OAK RIDGE, TENNESSEE 

Environmental Sciences Division 

Publicaton No. 1931 

PREPARED FOR THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION 11 

MAY 1979 

.--
SUMMARY 

In this testimony I evaluate the utilities' estimates of the numbers of 

ish impinged ai: the Bowline, Lovett, Indian Point, Roseton, and Danskamner 

enerating statlons. I describe the methods used to compute the number of 

ish killed by impingement at each of these plants and discuss four sources 

t

f bias that can affect impingement estimates: collection efficiency, 

impingement, impingement on inoperative travelling screens, and impingement 

urvival. Wherever possible I estimate the magnitude of each bias. Finally,

I present plant and species-specific adjustment factors that can be used to 

cale the impingement estimates up or down to account for these biases. 

I 

b 

I Preceding page Hank I-iii 

.. 
TABLE OF CONTENTS

1 Section Page 

SUMMARY.. ,. ............................. I-iii I 

1. Introduction ........................... 1 

1.1 How Impingement Estimates are Calculated .......... 1 

1.2 Biases that Influence Impingement Estimates ......... 2 

1.2.1 Collection Efficiency ................ 2 

1.2.2 Reimpingement .................... 3 

1.2.3 Impingement on Inoperative Screens .......... 4 

1.2.4 Impingement Survival ................. 4

I 2. Evaluation of Utility Estimates 

of the Number of Fish Impinged .................. 5 

2.i Co'llection Efficiency .................... 5 

2.11.1 Indian Point Unit 2 ................. 5

I 2.1.2 Indian Point Unit 3 ................. 6 

2.1.3 Bowline. ....................... 6 

2.jt.4 Roseton ....................... 8

I 2.2 Reimpingement ........................ 8 

2.2.1 Indian Point Units 2 and 3 .............. 8 

2.i!.2 Bowline ....................... 8 

2.2.3 Roseton and Danskamer ................ 11 1 2.3 Impingement on Inoperative Travelling Screens ........ 11 

2.3.1 Indian Point Units 2 and 3 .............. 12 

2.3.2 Bowline ................... -.... 12 

2.3.3 Roseton ....................... 15 

2.4 Impingement Survival .................... 15 

2.4.1 Experimental Methods ................. 16 

2.4.2 Results of the Impingement Survival Studies ..... 18 

2.4.2.1 Atlantic Tomcod ................ 18 

2.4.2.2 Clupeids ................... - 23

2.4.2.3 White Perch and Striped Bass ......... 23 

2.5 Comparison Between Impingement Survival and Collection Efficiency . . . . . . - 43 

31. Conclusions ............................ 45 

I 4. References ............................ 48 

. - I -v 

Preceding page blank 
LIST OF TABLES 

!able Page 

Estimation of collection efficiency 11 at the Bowline Point Generating Station . . . . . . . . . . . 1-9 

Inoperative screen adjustment factors, calculated 1* for 1 to-5 inoperative screens out of a total of 6 . . . . . e . 14 

3 Normal operating procedures for travel 1ing 

screens at five Hudson Rrver power plants . . . . . . . . . . . 17 

4 Sumnary of Atlantic tomcod impingement survival data . . . . . . 19

15 Sumnary of clupeid impingement survival data . . . . . . . . . . 24 

Sumnary of white perch impingement survival data . . . . . . . . 26 

Sumnary of striped bass impingement survival data . . . . . . . . 35 

8 Comparisoin of observed percent survival of white perch

and striped bass under identical experimental conditions,

Bowline Point Generating Station (from Tables 6 and 7j . . . . . 38 . 

~ I 9 Adjustment factors derived for impingement estimates at 

Hudson River power plants . . . . - . . . . . . . . . . . . . . . 46 

.- ... -

Preceding page blank I-vii 
1. INTRODUCTION 

In order to facilitate understanding of my assessment of this aspect of 

he utilities' case, I begin with a brief outline of the data, methods, and Fiases involved in computing the number of fish impinged and killed by a 

pwer plant. I describe each component of the computational procedure and 

k

identify those components in which there is a substantive disagreement 

etween my position and that taken by the utilities and their consultants. 

hese disagreements are discussed in detail in Section 2. 

At first glance it seems that there should be no substantive 

isagreements iis to the number of fish that are impinged at Hudson River 

power plants. All one has to do is collect and count the fish that are 

washed off the travelling screens. However, the problem is not quite that 1s imp 1e . Only at Indian Point are attempts made to collect and count all 

fish that are washed off the screensI At all other plants the screenwash is 

sampled once or twice a week (usually for 24 hours), and the resulting counts 

are scaled up to arrive at weekly and/or monthly estimates of the numbers of 

D fish impinged. Moreover, the raw counts of fish impinged at any plant are 

subject to several sorts of biases that can lead to overestimates or 

nderestimates of the true number of fish killed by impingement. First, not 

all impinged fish are actually collected. A certain percentage, highly variable from plant to plant, are washed off the screens back out into the Iriver, or are ctaten by scavengers. Since these fish are not collected, they 

are not included in the impingement counts. Second, at plants where impinged

fish are sampled only periodically, the same fish may be impinged more than 

once, inflating the impingement counts. Third, at some plants fish may be 

impinged on inoperative travelling screens and thus not collected or counted. 

Finally, for some species at some plants, a substantial fraction of impinged

fish may survive impingement if they are promptly returned to the river. 

All of these potential biases must be considered in order t:, assess the 

re 1i ab i 1ity of impi ngement estimates and in order to determi ne whether ( and 

'by how much) these estimates must be adjusted. 

Since I believe that the impingement totals used in calculating

conditional impingement mortality rates should reflect impingement at all 

plants, not just at those that are the subject of these proceedings, Ievaluate the impingement estimates for Lovett, Danskamer, and Albany along 

with those for Bowline, Indian Point, and Roseton. 

11. P HOW IMPINGEMENT ESTIMATES ARE CALCULATED 

At Indian Point Units 1, 2, and 3, all (or nearly all) screenwashes are 

monitored and attempts are made to collect, identify, and count all imenged

Bfish. At all other plants the screenwashes are monitored for 24 hours once 

or twice a week. These sample collections are scaled up to monthly totals 

in the following way (Exhibit UT-6, p. 10.2-6): E 

I 

r -1 I 

1 
1-2 

Impingement samples were used to estimate the total number of 

selected species impinged monthly and annually at Roseton. Each 

month was divided into four time intervals: day 1 to 7, day 8 to 

14, day 15 to 21, day 22 to last day of the month. For each time 

interval the total number of fish collected was divided by the 

total flow in million gallons for all samples within that interval, 

to produce an impingement rate. The impingement rate (number of 

fish per million gallons) for the four time intervals was averaged 

to produce a mean monthly impingement rate. When there was no 

sample taken within one of the four time intervals, the remaining intervals were averaged to obtain the monthly rate. The mean 

monthly impingement rate was then multiplied by the total monthly

plant flow in million gallons to produce an estimated total number 

of fish impinged per month. The monthly totals were sumed to 

obtain an annual total. 

An equivalent paragraph can be found on p. 10.2-6 of Exhibit UT-7. Sirnila 

methods have been used at Lovett (Lawler, Matusky, and Skelly 1976a),

Oanskamner (Lawler, Matusky, and Skelly 1974), and Albany (Lawler, Matusky

and Skelly 1975). This method of scaling up impingement samples is 

critically dependent on the assumption that the number of fish impinged

during any period is directly proportional to the total intake flow during

that period. The utilities' consultants and I agree that in reality this 

not always the case (Transcript pp. 4333-37). Texas Instruments (1974), f 

example, did not find a strong correlation between impingement counts and 

volumetric flow rates at Indian Point Units 1 and 2. Although the failure 

of this assumption necessarily reduces the precision of the resulting

impingement estimates, I do not believe that it introduces a bias toward 

either underestimating or overestimating the number of fish impinged per

month. 

1.2 BIASES THAT INFLUENCE IMPINGEMENT ESTIMATES 

Although the questionable assumption that impingement is proportional 

to pawer plant intake flow probably does not introduce biases into the 

monthly and annual impingement estimates, four phenomena that do introduce 

such biases have been identified. The utilities have assumed (Exhibit UT-: 

Sections 2-VI and 2-VII) that, with the exception of Indian Point Units 2 

and 3, these biases offset one another and no adjustments of the impingemer

estimates are necessary. I believe that for some species at some plants tt 

biases clearly do not offset one another, and therefore, some adjustments 

are necessary. 

c

1.2.1 Collection Efficiency 

Not all impinged fish are actually collected and counted during screenwash monitoring, for reasons that are not completely understood. SOP 

fish are probably washed back into the river by tidal action. Some may sli 

through gaps between screens or may not be removed from the screens by the 
1-3 

screenwash spray. Others are probably scavenged from the screens by gulls,

crabs, and eels. Utility consultants have conducted studies at Indian Point, 

Bowline, and Roseton in order to estimate the fraction of impinged fish that 

are actually collected and counted, In Exhibit UT-7 (Table 10.2-4) the 

utilities estimate collection efficiency at Bowline to be about 90%. Recent 

data collected by LMS have convinced me that in reality collection efficiency 

at i3owline is considerably lower, less than 80%. No collection efficiency

studies at Roseton were reported in Exhibit UT-6, but studies performed after 

tnis exhibit was filed indicate that collection efficiency at this plant 

averages 'no higher than 75% and is lower for the small fish (< 13 cm in 

length) that dominate impingement collections. 

For purposes of impact assessment the utilities have assumed 

(Exhibit UIT-3, Sections 2-VI and 2-VII) that collection efficiency at 

Indian Point Unit 3 is 80%. Although this figure is consistent with 

preliminary collection efficiency studies performed by Texas Instruments 

(1977a), more recent studies (Section 2) indicate a somewhat lower value 

(approximately 70%). Collection efficiency at Indian Point Unit 2 is 

extremely low, The utilities have used a value of 15% in their impact 

assessments (Exhibit UT-3, Sections 2-VI and 2-VII); more recent studies 

confirm the accuracy of this value. 

i.2.2 mmpinqement 

On days when impinged fish are not sampled, impinged fish are returned 

to the river. If the point of return is relatively close to the intake 

structure, some of these fish may be drawn back into the intake and 

reimpingedl. On days when impinged fish are sampled, the fish collected Will 

include all fisk impinged for the first time on that day (subject to 

adjustments for collection efficiency), and also some fish that have been 

impinged one or more times previously. 

Ideally, the impingement count over 24 hours should include only (but

all) those fish impinged for the first time. Such a count is an estimate of 

the total number impinged one or more times [if they had not been collected, 

a fraction of them would have been subsequently reimpinged). Including

reimpinged fish in effect double-counts reimpinged fish and inflates 

estimates of the total number of fish that are impinged. 

Studies conducted at Bowline by Ecological Analysts (Exhibit UT-7,

Sections 10.3.2.2 and 10.3.3.2) indicate that with the sampling methods now 

employed at Bowline, approximately 10%of the fish collected have been 

previously impinged. On the basis of studies at Roseion and Danskamer 

(Exhibit UT-6), I believe that reimpingement is negligible at all other 

- p 1ants. 
1-4 

1.2.3 Impingement on Inoperative Screens 

At i3wline and Roseton the two generating units share a conanon intake 

bay containing hll circulator pumps and travelling screens. Thus, when a 

screen is inoperative and cannot be rotated and washed, it continues to 

impinge fish. By my calculations (based on results reported in 

Section 10.2.3.1.4 of Exhibit UT-71, a screen that is inoperative for 1 to 

5 days impinges about 11%as many fish as does a normally operating screen 

during the same period. According to Exhibit UT-7 (p. 10.2-12), such 

breakdowns occurred “on many occasions from 1974 through 1976” at Bowline. 

1.2.4 fmpingement Survival 

Results reported in Exhibits UT-6 and UT-7 indicate that not all 

impinged fish are killed as a direct result of the impingement experience.

Although the magnitude of indirect impingement mortality (e.g., increased 

susceptibility to disease or vulnerability to predators due to the stress c 

impingement) has not been estimated, it appears that under certain operatir

conditions the survival of several species (most notably Atlantic tomcod) 

can be substantial. Assuming that all impinged fish are killed will, in tiabsence of offsetting biases, tend to inflate estimates of impingement

impact. 
1-5 

2. EVALUATION OF UTILITY ESTIMATES OF THE NUMBER OF FISH IMPINGED 

I believe that the utilities have underestimated the monthly and annual 

numbers of white perch, striped bass, and clupeids killed by impingement at 

Hudson River power plants. My two specific points of disagreement are: 

(1) The utilities do not include fish impinged at Danskamner, Lovett, 

or A! bany. 

(2) Utility estimates of collection efficiency at Indian Point 

Unit 3, Bowline, and Roseton are too high. 

Fish killed at Lovett, Danskamner, or Albany are just as dead as those killed 

at Indian Point, Bowline, or Roseton. The impact of impingement at the three 

plants at issue in these proceedings is an incremental impact added to the 

preexisting impacts caused by impingement at Lovett, Danskamner, and Albany. 

Neither the significance to Hudson River fish populations of the additional 

losses caused by impingement at Indian Point, Bowline, and Roseton, nor the 

reduction in impact that would result from the installation of mitigating 

measures (e.g., closed-cycle cooling), can be understood unless the impacts 

of all six plants are considered. 

With reference to the second point of disagreement, whether the 

impingement estimates calculated by the utilities must be scaled up to 

account for lower estimates of collection efficiency depends upon the 

magnitude of any offsetting biases. Of the three sources of bias (in 

addition to collection efficiency) described in Section 1.2, impingement 

survival is undoubtedly the most important. My analysis of the utilities' 

impingement survival studies indicates that the survival of impinged white 

perch and striped bass at Bowline, Roseton, Danskamner, and Albany is 

probably high enough to offset the bias due to collection efficiency. 

Atlantic tomcod survival during the fall, winter, and early spring at these 

plants appears to be high enough so that impingement estimates for this 

species, for these seasons, should be scaled down. Survival of clupeids at 

all plants, and survival of all species at Indian Point (where no fish are 

returned to the river) and Lovett appears to be negligible. 

The remainder of th% section consists of my assessments of the 

magnitude of each of the four biases discussed in Section 1.2 and how they 

vary amng plants and fish species. 

2.1 COLLECTION EFFICIENCY 

2-1.1 Indian Point Unit 2 

The results of all collection efficiency tests carried out to date at 

Indian Point Unit 2 are sumnarized in Exhibit UT-105, Tests were first 

performed at this unit in 1974 and 1975. The results of these tests 
1-6 

indicated that with the air curtain operating, only about 15%of the impin

fish were being collected and counted (Texas Instruments 1975, 1976). It 

appeared from preliminary tests in 1974 and 1975 that collection efficienc. 

increased to about 50L when the air curtain was turned off (Texas

Instruments 1976). In 1977, after air curtain operation was permanently 

d isconti nued, new tests were conducted, Surpr isi ngly, the 1977 resu 1ts we' 

no different from those obtained earlier with the air curtain operating. t 

1500 test fish released in May and June of 1977, only 224 (14.9%) were 

recovered (Exhibit EPA-94). No explanation has been offered as to why the 

1977 results differ so greatly from those obtained in the e'arlier tests withe air curtain off. 

The 1977 experiments involved more release dates (9 vs 3) and more fir 

(1500 vs 1000) than did those performed in 1974-75. Until the cause of tht 

discrepancy is discovered, I believe that the results of the more extensivt 

1977 experiments should form the basis for an estimate of collection 

efficiency at Indian Point Unit 2. These results support the value (15%)

used by the utilities in Exhibit UT-3, 

2.1.2 Indian Point Unit 3 

The estimate of collection efficiency at Indian Point Unit 3 used in 

the utilities' calculations of conditional impingement mortality rates . (Exhibit UT-3, Sections 2-VI and 2-VII; Exhibit UT-6, Section 10.4; 

Exhibit UT-7, Section 10.4) is based on the results of tests conducted in 

1976 (Exhibit UT-105, Table 1, part e). Seven separate experimental releas 

of marked fish were conducted during June, July, and August of 1976. The 

percent recovery of the released fish ranged from 75% to 86%, with a mean c 

79.9%. More extensive tests were conducted during 1977 (Exhibit UT-105,

Table 1, part e). These new tests involved 32 separate experimental releas 

carried out on 11 days between March and September. The percent recoveries 

observed during the 1977 tests were more variable and, on the average,

substantially lower than those observed in 1976. Overall, 68.9% (1323 out 

of 1919) of the fish released in 1977 were recovered. Pooling all the data 

from both years yields a percent recovery of 71.2% (1758 out of 2469). I 

believe that a collection efficiency of 70% is an appropriate adjustment

factor for the impingement estimates at Indian Point Unit 3. 

2.1.3 Bowline 

Results of experiments designed to measure collection efficiency at 

iJowline are presented in Table 10.2-4 of Exhibit UT-7. The data reported i 

this table were derived from eight experimental releases-conducted during

the period January 31-March 21, 1977. The percent recaptures from these 

releases were all very high, ranging from 81%to 98%, with a mean of 89%. 

' However, this prefiled testimony reflects incomplete data. More complete data covering the period October 1976-lUlayy 1978 indicates that collection . 
I 

t 1-7 

I efficiency at Bowline is probably less than 80%. Exhibit EPA-36 contains 

the results obtained from 30 releases conducted by LMS between October 27,

1976 and June 29, 1977. Exhibits UT-113, UT-114, and UT-115 contain the 

results Gf 88 experiments spanning the period October 26, 1976-Ray 29, 1378. 

These results include all of the results contained in Exhibits UT-7 and B EPA-96.

I LMS did not use the 1976-78 data to calculate an overall estimate of 

collection efficiency at Bowline, Instead, Exhibit UT-115 contains two 

separate estimates of collection efficiency for each month, calculated in 

two different ways. The first estimate for each month was obtained by

computing the percent recoveries for each experimental release during that 

month, and then averaging these percent recoveries. Reslrl ts obtained from 

releases involving fewer than 50 fish, as we11 as results obtained from the 

purportedly aberrant release of May 2, 1977, were deleted from these 

estimates. The second estimate for each month was obtained by pooling the 

data collected during that month. That is, the percent recovery was computed

by dividing the total number of fist? recovered from all experimental releases 

during that month by the total number of fish released. 

I 

S 

1 

I 

I prefer the second method of computation. I have no quarrel with the 

exclusion of data on the grounds of insufficient sample size. However, I am 

not convinced that it is legitimate to exclude data simply because the 

sampling conditions were unusual. The particular experimental release at 

issue here is that conducted on May 2, 1977. In Exhibit EPA-96 (p. 1) LMS 

stated: t 

& 

The malfunction of the screenwash pumps combined with heavy debris 

provided for a non-quantitative estimate of recovery efficiency. 

1 

On transcript pp. 4426-27 Mr. Dew of LMS elaborated. He explairled that the 

travellicg screen onto which the fish had been released on May 2 could not 

be completely cleaned because of unusually low screenwash prssure combined 

with high debris load. Many fish apparently became entangled in debris that 

could not be washed off the screen. Consequently, only 2 of 100 released 

fish were recovered. I 

I 

It seems likely that "unt!sual" conditions, such as those described by

Mr. Dew, must occur occasionally on days when impingement collections are 

made. In fact, May 2, 1977 was an impingement collecticn date, according to 

Mr. Dew (transcript p. 4426)TAlthough the collection efficiency data for 

May 2 were deleted by LMS, the impingement collection itself was considered 

valid and was used to estimate impingement rates for the 8owline plant

(testimony of Mr. Dew, transcript p. 4426). I believe that collection 

efficiency studies should be conducted under the same range of conditions 

that prevai 7 during ordinary impingement co llections. Co 11ection-eff ic iency data generated under abnormal conditions should not be discarded unless 

impingement collections made under the same conditions are also discarded. 

I have calculated a collection efficiency for Bowline by summing ti?e releases 

and recaptures for all of the experiments, including that of May 2, 1977. 

ff 

i 

8 

T 

I 
1-8 

This computational method allows data from all the experiments to be used! 

not just from those in which 50 or more fish were released. With this met 

the results obtained from each experiment are, in effect, weighted by the 

number of fish released. The results of my computations are. presented in 

Table 1, The calculated collection efficiency is 75,7%. If the May 2, 15 

results are excluded, this va?ue increases only slightly, to 76.8%. I 

conclude on the basis of the LMS studies that collection efficiency at 

Bowline is between 75% and 80%, or more than IO% lower than is reported ir 

Exh ib it UT-7. 

2.1.4 Roseton 

Although no collection efficiency studies are reported in Exhibit UTsuch studies were conducted at Roseton in 1978. Results covering the peri

January-March are contained in Exhibit EPA-97. Of 606 marked fish release 

on 12 separate release dates, 458 were recaptured, yielding a recovery 

percentage of 75.6%. Interestingly, Exhibit EPA-97 contains a breakdown c 

the release/recovery data by size-class. Table 2 of Exhibit EPA-97 shows 

that collection efficiency is strongly affected by the size of impinged fi 

It is particularly noteworthy that the collection efficiency for fish less 

than 13 cm. in length was only 53.5% The vast majority of impinged white 

perch, striped bass, Atlantic tomcod, alewife, blueback herring, American 

shad, and bay anchovy are less than 13 cm long. Thus, collection efficier 

for the species of interest in these proceedings may be ws11 below 75%. 1. 

fish larger than 25 cm length are removed from the computations (very few 

impinged fish belonging to the species of interest are that large), the 

percent recovery of the remaining fish is 71.6%. I conclude on the basis 

the data in Exhibit EPA-97 that collection efficiency at Roseton, for fist 

of species and size that are of principal interest to these proceedings, i 

probably no higher than 70%, and may be considerably lower. 

2.2 REIMPINGEMENT 

2.2.1 Indian Point Units 2 and 3 

Reimpingement is not a source of bias at Indian Point because impinge

fish are not returned to the river, 

2.2.2 Bowline 

. Section 10.3.3.2 of Exhibit UT-7 contains results of some rather eleg experiments conducted by Ecological Analysts (EA) in or3er to estimate the 

reimpingement rate at Bowline. Of particular interest are the results of 

the "long-term survey" (Section 10.3.3.2.2), as these results can be used 

calculate the fraction of fish collected on a typical impingement sampling day that have been previously impinged. The experiment involved: 
1-9 

Table 1. Estimation of collection efficiency at the Bowline Point Generating

St at i on 

Dates Number re-leaseda Number recaptureda X Recaptured 

All release dates 6582 4981 75.7 

Excluding May 2, 1977 6482 4979 76.8 

aTota1 number of releases and recaptures from 88 experiments conducted 

between October 1976 and May 1978 (from Exhibit UT-114). 
1-10 

(a) marking all white perch impinged during a 24-hour release period, 

(5) releasing these marked fish, and 

(c) monitoring screenwashes on subsequent days and calculating the 

fraction of marked fish in each day's collection of white perch. 

EA released marked fish on five consecutive days, using a different 

color mark for each release period. Tne results of EA'S April 1976 

experiment are tabulated in Table 10.3-22 of Exhibit UT-7. 

Table 10.3-22 indicates that the probability of an impinged and releas1 

fish being reimpinged is at a maximum during the first 24 hours after relea 

and declines steadily with time to 1%or less by four days after initial 

. impingement. EA used the data in Table 10.3-22 to derive an equation

expressing the probability of reimpingement as a function of time since 

in itiit impingement: 

where t = time in days since initial impingement. 

Normally, impingement sampling is conducted over one 24-hour period

each week at Bowline. In order to reduce the effects of reimpingement on 

the impingement counts, fish impinged during the 24 hours prior to the 

beginning of the sanpling period are not returned to Bowline Pond. Thus, 

fish collected during an impingement sample can include reimpinged fish thal 

were first impinged between 1 end 6 days prior to sampling. EA used the 

decay rate (-0.83) from Eq. (I) and ar! estimate of the fraction of each day'

catch composed of fish also impinged during the previous 24 hours (from

Table 10.3-22) to calculate the contribution of reimpinged fish to a typica; impingement sample (8.1%). I obtained a different and slightly higher

[lC.6%) estimate by integrating Eq. (1) from t=lto t=6. 

In Table 10.3-23 of Exhibit UT-7, EA presents data obtained from a 

simi jar experiment conducted in January, 1977. Although no calculations 

based on these data are included in Exhibit UT-7, less reimpingement was 

observed during this experiment than during the April, 1976 experiment.

have used the data in Table 10.3-23 of Exhibit UT-7 to develop an equation

for the January experiment similar to Eq. (1): 

Pr(t) = 7.2e-0.62i -

Integrating Eq. (2) from t=lto t=6 yields a value of 6.0% as the 

contribution of reimpinged fssh to a typical impingement sample. 

I 
1-1 1 

In my opinion, EA'S experiments generally support the conclusion, stated 

on p. 10.2-10 of Exhibit UT-?, that approximately 10%of the fish collected 

during a typical impingement sample at Bowline have been previously impinged.

However, the results of the January, 1977 experiment indicate that 

reimpingement may be a few percent lower during the winter. This observation 

is important because, as is shown in Tables 10.2-12 and 10.2-17 of Exhibit 

UT-7, impingement rates for white perch and striped bass are high at Bowline 

during the winter. 

2.2.3 -Roseton and Danskammer 

The impingement sampling procedures employed at Roseton and Danskamner 

are similar to that at Bowline: the travelling screens are washed prior to 

the beginning of each 24-hour collection period. The fish collected during

this prewash are retained rather than returned to the river. In an 

experiment designed to measure the reimpingement rate of white perch at 

Roseton (Exhibit UT-6, Section 10.3.3.2.1), it was found that virtually all 

reimpingemertt occurred within a few hours after release. The total 

reimpingement rate of the white perch released in this experiment was fairly

high. I have calculated, using data presented in Table 10.3-9 of Exhibit 

UT-6, that of 914 live and dead white perch released, 163 (17.8%) were 

reimpinged. However, only 3 were reimpinged more than five hours after 

release and only one was reimpinged more than 10 hours after release. The 

impingement sampling procedure employed at Roseton reduces the potential for 

reimpingement to a very low level (Exhibit UT-6, Section 10.2.3.1.2). It is 

interesting that nearly all the reimpinged fish were released alive. 

Whereas 23.3% (158 out of 679) of the live fish were reimpinged, only 2.1% 

(5 out of 235) of the dead releases were recovered. 

Experiments conducted at Danskamner, sumnarized in Section 10.2.3.1.2 

of Exhibit UT-6, indicate that reimpingement at this plant is as low as that 

observed at Roseton. Unlike Bowline, where fish are returned to Bowline 

Pond, fish impinged at Roseton, Danskamner, and at all other Hudson River 

power plants (except Indian Point, where none are returned), are returned 

directly to the river. Fish (especially dead fish) returned to the river 

can be swept away from the vicinity of the plant by tidal flushing. Tidal 

flushing is undoubtedly much weaker in Bowline Pond, and may not occur at 

all when the plant is operating and impinging fish. I believe that this 

accounts for the difference observed between reimpingement at Bowline and 

reimpingement at Roseton and Danskamer. Reimpingement at other plants is 

likely to be more simi lar to Roseton and Danskamner (i.e., virtually no 

reimpingement) than to Bowline. 

- 2.3 IMPINGEMENT ON INOPERATIVE TRAVELLING SCREENS 

At some plants, notably at Bowline, fish can be impinged on inoperative travelling screens. Since these fish cannot be collected and counted,

impingement counts for days on which one or more travelling screens are 

inoperative will be underestimates of the true number of fish impinged. 
1-12 

2.3.1 Indian Point Units 2 and 3 

Since each travelling screen at Indian Point is located in a separate forebay, the circulator pump located in a forebay containing an inoperative 

screen must be shut off to prevent the clogging and eventual collapse of thk 

screen. For this reason, impingement on inoperative screens is not a sourcf 

of bias at the Indian Point Plant. 

2.3.2 Bowline 

Both generating units at Bowline draw water from a common intake bay

containing six travelling screens. Section 10.2.3.1.4 of Exhibit UT-7 

describes some experiments that were conducted at Bowline in order to 

estimate the magnitude of the bias associated with impingement on inoperatit 

screens. The procedure is described on p. 10.2-14 of Exhibit UT-7: 

From 29 November 1976 to 19 January 1977, the cleaning procedure

of travelling screens at the Bowline Point intake was controlled 

to simulate the condition of a non-operating screen. One of the 

three screens at Unit 2 remained stationary for 1, 2, 3, and 5 day periods while the other two screens were cleaned every four hours. 

After remaining stationary for the designated number of days, the 

test screen was cleaned and the total number collected was compared

with the total collected from all screens at Unit 2 during the test 

interval (Table 10.2-5). 

The results of the experiment are sumnarized in Table 10.2-5 of Exhibit 

UT-7. When one of the three screens at Bowline Unit 2 was inoperative, between 5 and 7% of the total number of fish impinged at Unit 2 were not 

recovered. The number of days of down-time did not appear to influence the 

fraction of the Unit 2 total impingement that was impinged on the inoperati\ 

screen. The inoperative screen accounted for about the same fraction of the 

total impingement collection (7%) after five days of down-time as after onlj 

one day. 

The bias estimated from Table 10.2-5 (5 to 7%) is strictly applicable

only if one third of the six travelling screens at Bowline are inoperative.

If only one of the six is inoperative, the bias will be smaller than that 

calculated in Exhibit UT-7; if more than two are inoperative, the bias will 

be larger. I have used the data in Table 10.2-5 to estimate the magnitude of the bias for any number of inoperative screens, up to 5 - The numbers in 

the column headed "NUMBER COLLECTED ON NORMAL SCREENS" are the total number 

of fish collected from two operating screens. Oividing the values in this 

column by two yields an estimate of the number impinged by a single operatir 

screen. It is possible to derive estimates of a "relative collection rate 

constant" (k) by calculating the ratio of the number of fish impinged on an 

inoperative screen to the number impinged on a normally operating screen. 

For example, on December 8-9, 6784 fish were collected from the two operatir 

screens and 220 were collected from the inoperative screen. On that date 
1-13 

the inoperative screen impinged 5.5% [lo0 x (220/3392)3 as many fish as did 

each operating screen. Therefore, our estimate of k for December 8-9 

is 0.065. 

I computed an overall estimate of k by sumning all of the normal screen 

collections and test screen collections in Table 10.2-5 of Exhibit UT-7. 

Since results obtained from the 2-, 3-, and 5-day studies were similar to . 

those obtained from tne 1-day studies, I saw no reason to calculate k 

separately for each data set. My overall estimate of k, calculated by the 

same procedure used in the above example, is 0.117. 

If one or more screens are inoperative, the number of fish impinged on 

these screens is equal to the number impinged per operating screen mcrltipled

by k times the number of inoperative screens: 

where 

Io = total number of fish collected from operating screens, 

Ii = total number of fish impinged on inoperative screens, 

no = number of operating screens, 

ni = number of inoperative screens, 

k = relative collection rate constant. 

The total number of fish impinged on all screens can be calculated from the 

f o 11owi ng equation : 

where 

IT = estimated total impingement on all screens. -

The term in parenthese (1 + kni/no) is an adjustment factor similar to 

the factors calculated for collection efficiency. Table 2 contains my inoperative screen adjustment factors, Calculated for 1-5 inoperative 

screens. 
1-14 

Table' 2. Inoperative screen adjustment factors, calculated for 1 to 5 

inoperative screens out of a total of 5. 

-

- Number of inoperative screens 

1 2 3 4 5 

Adjustment factor 1.023 

(= 1 + kni/noP 

1.059 1.117 1.234 1.585 

ani = number of inoperative screens 

no = number of operating screens 

k= relative impingement rate constant (ca lcul ated from Table 10.2-5 of 

Exhibit UT-7) = 0.117. 

F 
-- 

S 

I 1-15 

1 It can be seen from Table 2 that unless more than two screens are 

inoperative, the bias in impingement estimates will be 6% or less for each 

day of down-time. Unless multiple screens are inoperative for extended 

period of time (i-e., weeks or months), biases due to the impingement of 

fish on inoperative screens will be negligible in comparison to the effects 

of reimpingement or collection efficiency at Bowline. Moreover, it seems 

likely that during an extended outage, an inoperative screen would eventually

clog completely with debris and cease impinging fish altogether. I 

tentatively- conclude that impingement on inoperative screens is 'a re1 atively

unimportant source of bias in the Bowline impingement estimates. 

I 

# 

It is possible that I have underestimated the magnitude of this bias,

for the following reason. Substantial numbers of fish may be scavenged from 

an inoperative screen by crabs and eels, especially if the screen is not 

cleaned for several days; This scavenging would result in the collection 

efficiency {of an inoperative screen being lower than that of an operating 

screen (frelquent washing reduces the opportunity for scavenging). This 

difference in collection efficiencies would, in turn, bias the results of 

the experiments described in this section by causing the contribution of the 

inoperative screen to the. total impingement count to be Underestimated. 

2.3.3 Roseton 

Like Blowline, the two units at Roseton share a common intake bay, and 

thus it is possible for fish to be impinged on inoperative screens. The 

longest screen outage at Roseton during 1974 was 48 hours (Huggins 1977).

Outages longer than two weeks in duration occurred three times in 1975 and 

four times in 1976. Three screens (out of eight) were out of service between 

October 13 and November il, 1976. All of the other extended outages involved 

single screlens. With the possible exception of the October-November 1976 

outage, I believe that impingement on inoperative screens has had a 

negligible effect on the accuracy of Central Hudson's estimates of 

impingement at Roseton. 

2.4 I MP INGEMENT SURVIVAL 

In their impact assessments the uti 1ities have assumed that all impinged

fish are killed. If this is in fact the case, then the impingement estimates 

presented by the utilities for Bowline and Roseton (and also those for 

Lovett, Danskamner, and Albany} must be scaled up to account for biases due 

to collection efficiency. However, if survival is substantial, then no 

adjustment of these estimates may be necessary. If survival is very high,

the impingement estimates may have to be scaled down. -

Impingement survival studies have been conducted at Bowline, Roseton,

Danskamner, and Indian Point Unit 3. As fish impinged at Indian Point were 

not returned to the river during any of the years for which impingement data 

aye available, the studies there are not relevant to estimating the impact 
1-16 

of impingement during those years and are not discussed here. Studies 

conducted at the other three plants have indicated that under some operatin

conditions survival of some species may be fairly high. Experiments at all 

three plants have shown that impingement survival is highest when travellin 

screens are rotated and washed continuously. However, under current 

operating procedures travelling screens at all plants are operated

intermittently rather than continuously {operation at Albany is almost 

continuous). In fact, it is apparently not possible to operate the 

travelling screens continuously for e-xtended periods of time. On transcrip 

pp. 4465-68 Mr. Hutchison describes the serious problems encountyed at 

Bowline because of extended operation in the continuous mode. Because 

the travelling screens at Bowline were not designed for continuous rotation 

breakdowns have been frequent. Each of the six screens has been rebuilt 

twice. Current practice, according to Mr. Hutchison (transcript 

pp. 5099-100), is to rotate the screens continuously only when impingement

exceeds 1000 fish per day. Table 3 sumnarizes the current screenwash 

procedures at Bowline, Lovett, Roseton, Danskamner, and Albany. 

In the following sections I discuss the design of the impingement

swvival experiments conducted at Bowline, Roseton, and Danskamer and the 

results obtained for Atlantic tomcod, clupeids, white perch, and striped

bass. 

2.4.1 Experimental Nethods 

Sections 10.3.2 of Exhibits UT-6 and UT-7 contain descriptions of the 

methods used in impingement survival studies conducted by Ecological

Analysts (EA) at Roseton and at Bowline. Although no description of the 

methods used at Danskamner is included in Exhibit UT-6, EA'S 1977 Progress

Report to Central Hudson (Ecological Analysts 1977) indicates that they are 

virtually identical to the procedures at Roseton. 

In most of the studies at Bowline impinged fish are collected in a nylc

mesh bag suspended in the impingement collection pit. In some of the 

experiments at Bowline, fish have been collected at the end of the screenwa: 

discharge pipe in an effort to assess whether the screenwash discharge systc

imposes stresses in addition to those caused by the impingement experience - itself. At Roseton and Danskamer fish are collected in a basket that float 

in the river at the end of the discharge pipe. 

After collection the fish are sorted immediately by species and are 

classified as live, dead, or stunned. The live and stunned fish are then 

transferred to a holding facility and observed for latent rnortdlity. The 

holding period at Bowline is 96 hours; at Roseton and Damkamner it is 

84 hours. The use of control fish has been an important element in all the 

impingement survival studies. In the first such studies (conducted at 

Roseton and Danskamner in 19751, control fish were exposed only to the 

holding facilities. Subsequently, control fish have been exposed to the 

entire process of collection, holding, and observation. 
1-17 

Table 3. Normal operating procedures for travelling screens operating at 

five Hudson River power plants 

P1 ant 

Bowline 

Lovett 

Roseton 

Dansk amner 

A1b any 

Screenwash Source of 

Mode pressure (psi ) i nf ormat ion 

Intermittent ;

&hour holda 

Intermittent;

8-hour holdc 

Intermittent;

2-hour ho 1dd 

1ntermi.ttent;

vari ab1e 

depending on 

debris load 

Screens washed 

automat i cally for 

3 minutes every

15 minutes 

30/60b Exhibit 7, pp. 2.2-10,

2.2-11; transcript pp.

5099-100 

100 Attachment 2 to letter 

from K. Marcellus of 

Consolidated Edison to H. 

Gluckstern of EPA, dated 

November 30, 1977;

Transcript p. 5098 

100 Letter from T. Huggins 

of Central Hudson to 

H. Gluckstern of EPA,

dated November 29, 1977;

Transcript p. 5098 

55-65 Letter from T. Huggins of Central iiudson to 

H. Gluckstern of EPA,

dated November 29, 1977; 

EA 1977 Progress Report to 

Central Hudson, fable 4-26 

a4 Attachment 2 to letter 

from I(. Marcellus of 

consolidated Edison to 

H. Eluckstern of �PA,

dated November 30, 1977 

aOperated in continuous mode when impingement exceeds 1000 fish per day. 

bLow pressure (30 psi) wash system mounted below high pressure (60 psi) 

system. F 

%perated in continuous mode during periods of high debris loading. 

doperated in continuous mode during periods of high debris loading and 

icing (such conditions generally occur between October and April). 
-- 

1-18 

2.4.2 Results,of the Impingement Survival Studies 

The results of the impingement survival experiments conducted at . 

Bowline by LMS in 1974 and 1975 and by EA in 1976 and 1977 are described ir 

Section 10.3.3.1 of Exhibit UT-7. Section 10.3.3.1 of Exhibit UT-6 contaii 

results of similar experiments conducted by EA at Roseton in 1975-76. 

Additional results from EA's 1977 studies at Roseton, as well as results 

obtained by EA at Danskammer during 1975-77, are described in EA's 1977 

Progress Report to Central Hudson (Ecological Analysts 1977). Many of the! 

results are inconclusive and/or inconsistent. However, two general

conclusions emerge: 

(1 1 Survival is highly variable among.species. Survival of adult 

Atlantic tomcod is uniformly high during the fall and winter, anc 

that of clupeids (primarily Alosa SPP.) is uniformly low during

all seasons. Survival of white perch and striped bass is 

intermediate. 

(2) Survivzl of white perch and striped bass is related to screenwasfprocedures. Highest survival is observed when screens are rotate 

and washed continuously. Lowest survival occurs when operation i 

intermittent. 

2.4.2.1 Atlantic tomcod 

Results of the Atlantic tomcod survival studies at Bowline, Roseton,

and Danskammer are summarized in Table 4. With the exception of 45 juvenil

tomcod collected at Bowline in 1974 by LMS (discussed below), all tomcod 

survival studies have involved adult fish impinged during the fall, winter, 

or early spring. Survival of these fish has been high under virtually all 

operating conditions at all three plants. Low survival was reported in 

sever31 experiments at Roseton and Danskammer involving a four-hour 

screenwash cycle. Few fish (at most 6) were tested in these experiments,

and thus, the reliability of the results is low. High survival was observe 

at Bowline under the same conditions. Survival percentages of adult tomcod 

appear to be consistently higher at Bowline than at Roseton. This result 

may be partially due to differences in screenwash pressure (Table 3). At 

Bowline the highest pressure used in any of the experiments is 60 psi. In 

contrast, high pressure at Roseton means 10G psi, the normai operating 

pressure at that plant. Low pressures used at Bowline range from 10 to 

30 psi, while at Roseton the lowest pressure used is 50 psi. 

Survival of impinged juvenile Atlantic tomcod may be less than that of 

adults. These cold-adapted fish (Exhibit EPA-198) are impinged primarily

during the sumner (transcript p. 10,8031, when they may already be stressed 

because of high water temperatures (Texas Instruments 1977b, p. V-75). The 

additional stress of impingement may be sufficient to cause substantial 

mortality. The meager evidence available to date supports this hypothesis.

Of the 45 impinged juveniles collected by LMS in June, 1974, only 43% 

survived for 96 hours in the holding facility. Unfortunately, no control 

fish were collected, and therefore, it is not possible to say with certaint, 
f 

1 1-19 

Table 4. Sumary of Atlantic tomcod impingement survival data 

Period Collection point 

BOWL1NE 

November- Co 1 1ection 

December 1976 pit 

December 1976 Discharge 

pipe 

June 1974 Co1 1 ection 

pit 

ROSETON 

January-March Collection 

1976 basket 

Operating mode and 

screenwash pressure 

Continuous, high 

pressure 

Continuous, low 

pressure 

Intermittent,

h i gh pressure 

Intermittent,

low pressure 

Continuous, h Igh 

pressure 

Continuous, low 

pressure 

Intermittent,

high pressure 

Intermittent, low pressure 

Unknown 

Conti nuou s high 

pressure 

Intermittents 

2-hr hold, high 

pressure 

Mumber of 

fish tested X Survivala Source 

3 100 Exhibit 7 

Table 10.3-4 

46b 100 

6b 100 

3b 100 

1 100 Exhibit 7 

Table 10.3-6 

1 100 

2 100 

3 100 

45 43 Exhibit UT-7 

Table 10.3-14 

92b 85 Ex hi b it UT-6 

Table 10.3-1 

43 77 
1-20 

Table 4. (continued) 

Operating mode and Number of 

Period Collection point screenwash pressure fish tested % Survivala Source 

ROSETON _. 

Fall 1975 Co1 1ection 

basket 

November- Co1 1 ecti on 

December . basket 

1976 

January- Co 1 1 ection 

March 1977 basket 

Continuous, high 

pressure 

Intermittent,

2-hr hold, high 

pressure 

Intermittent,

4-hr hold, high 

p ressure 

Continuous, 

low pressure 

Continuous 

high pressure 

Intermittent,

2-hr hold,

low pressure 

Intermittent,

2-hr hold,

high pressure 

Intermittent, 

4- hr ho 1d,

low pressure 

Intermittent,

4-hr ho1d,

high pressure 

Continuous,

low pressure 

Continuous , high pressure 

4 0 Exhibit UT-6 

Table 10.3-3 

13 8 

2 0 

19 84 Exhibit UT-6 

Table 10.3-5 

67 97 

13 69 

20 90 

2 100 

1 0 

108 83 EA 1977c 

Table 4-13 

120 63 
March 

1 Table 4. (continued) 

Period Collection point 

a January- Co11ection ROSETON1977 bask et 

4 D MSKAMMER 

Fall 1975 Co11ect i on 

bask et 

& November- Co11ect on 

December basket 

1976 

E January- Collect on 

March 1977 basket 

1-21 

Operating mode and Number of 

screenwash pressure fish tested X Survivala Source 

intermittent,

2-hr hold,

low pressure 

Intermittent, 

2-hr hold, 

high pressure 

intermittent,d

4-hr hold 

Continuous 

lntermittent, 

2-hr hold 

Continuous 

Intermittent,

2-hr hold 

73 66 EA 1977C 

Table 4-13 

111 70 J 

6 0 EA 1977 

Table 4-25 

36 75 EA 1977 

Table 4-27 

29 72 

242 83 EA 1977 

Table 4-31 

716 87 

-SURVIVAL OF CONTROLS EXPOSED ONLY TO COLLECTION AND HOLDING PROCEDURE I BOWLINE 

November- Co11ection 3 100 Exhib t UT-7 

pit -' Table 10.3-5 

c 

Ir 

c 

0 

s 
I, 

1-22 

Table 4. (continued) 

Operating mode and Number o f Period Collection point screenwash pressure fish tested % Survival a Source 

-~ 

ROSETON 

November- Co 11ection 20 1 100. Exhibit UT-6 

December basket Table 10.3-6 

1976 

JanuaryMarch 1977 

208 98 EA 1977 

page 4-25 

=Percent alive at end of observation period (96 hours at Bowline, EM hours at Roseton and 

Danskamner). 

BData collected under the same conditions (sampling point, operating mode, and screenwash 

pressure) are pooled. 

CEcological Analysts 1977 Progress Report to Central Hudson. 

dscreenwash pressure for all impingement survival studies at Danskamner is 55-65 psi. 
1-23 

whether it was the stress of impingement . - or the stress of collection and .

observation that was responsible for the mortality. 

E 2.4.2.2 Clupeids 

There have been relatively few studies relating to the survival of 

impinged clupeids (alewife, blueback herring, American shad, and gizzard

shad). What data do exist show that these fish are extremely sensitive t o 3. stress. As can be seen from Table 5, virtually none of the impinged clupeids collected and held for observation at Bowline, Roseton, and Danskamner have 

survived to the end of the holding period. I do riot believe that more than 4 negligible survival of these fish occurs at any plant under current modes of 

travelling screen operation. 

f 2.4.2.3 -White Perch and Striped Bass 

Results of latent survival studies involving white perch (Table 6) and 

striped bass (Table 7) have shown that these species are intermediate between 

'the mre hardy Atlantic tomcod and the highly sensitive clupeids with respect

to their resistance to the stress of impingement. Because of the high

variability of these results, it is not possible to estimate the fractior?.al 1 survival of impinged white perch and striped bass with the same accuracy and 

precision possible for estimates of collection efficiency or impingement.

It is, however, possible to make qualitative assessments of seasonal 

variations in survival and of the effects of screenwash procedures on 

survival. 

My assessments of these effects will apply to both species, even though f in many cases the only available data relate to white perch. A priori, one 

would expect the responses to stress of these two closely relaTed species to 

be similar. Experiments conducted at Bowline between 1974 and 1976, the 

only series of experiments that involved substantial numbers of striped bass, 

support this intuitive judgment. 1 have used the data in Tables 6 and 7 to 

compare the percent survivals of impinged white perch and striped bass 

collected at Bowline under the same conditions (Table 8). The correlation 

between the two sets of numbers (r = 0.64) is statistically significant zt 

the 1%level. Moreover, neither species exhibited consistently higher

survival over all experimental conditions; observed white perch survival was 

higher than that of striped bass in five of the fifteen comparisons, and was 

tower i n seven. 

e Even a superficial inspection of Table 8 shows that for both white perch

and striped bass, survival is considerably higher when the travelling screens 

at Bowline are operated in the continuous mode than when the intermitent 

mode is employed. However, Table 6 shows that this pattern has not been 

c:onsistently observed for white perch impinged at Roseton and Danskamer. 

The highest survival of white perch at both of these plants has been obtained 

cluring continuous operation: eight out of nine observations of 40% latent 

a 

f 

e 

I 
1-24 

Table 5. Sumnary of clupeid impingement 'survival data 

Operating mode and Number of 

Period Collection point screenwash pressure fish tested % Survivala -Source 

BOWL1N E 

November- Co 11e c tion 

December pit 

1976 

November- Discharge

December pipe 1976 

November Col1ect i on 

1974 pit 

Diseharge 

Pipe 

ROSETON 

Fall 1975 Co 11ection 

basket 

Continuous, 

high pressure 

Continuous, 

low pressure 

Intermittent, 

high pressure 

Intermittent,

low pressure 

Continuou s, high pressure 

Continuous,

low pressure 

Intermittent,

high pressure 

Intermittent,

low pressure 

Unknown 

Unknown 

Continuous, 

high pressure 

Intermittent,

2-hr hold, 

high pressure 

89b 10 Exhib it UT-7 

Table 10.3-4 

51 0 

28 0 

22 0 

1 0 Exhibit UT-7 

Table 10.3-6 

9 

1 

2b 

60 --. 0 Exhi bit UT-7 

Table 10.3-14 

93 0 

24C 0 Exhibit UT-6 

Table 10.3-3 

5995c -0 
1-2s 

8.Tab’le 5. (contirwed) 

Operating mode and Number of 

Period Collection point screenwash pressure fish tested % Survivala Source 

ROSETON 

Fall 1975 .I : Collection Intermittent, . 381c 0 Exhibit UT-6 

hasket 4-hr hold. Table 10.3-3 

high pressure

I, Intermittent, 4645= 0 

6-hr hold,

high pressure &>DANSKAMMER 

Co11 ection Continuou sd 107C 1 EA 1977e 

blasket Table 4-25 

Intermittent,

2-hr ho 1 d 

16°C 0 

Intermittent,

4-hr hold 

314C 0 

Intermittent,

6-hr hcld , 2436c 0 

SURVIVAL OF CONTROL FISH EXPOSED ONLY TO COLLECTION AND HOLDING PROCEDURE 

s 

BOWLINE -

November Co1 1 ection . 40 0 Exhib it UT-7 

pit Table 10.3-5 

1976

aPercent alive at end of observation period (96 hours at Bowline, 84 hours at Roseton and 

Danskamner). tbData collected under the same conditions (sampling point, operating mode, and screenwash 

pressure) are pooled. 

CData for all clupeid species are pooled. I

cif dscrcenwash pressure for all impingement survival studies at Danskamner is 55-65 psi. 

eEcologica1 Analysts 1977 Progress Report to Central Hudson. 

I 
1-26 

Table 6. Sunary of white perch impingement survival data 

Operating mode and Number of 

Period Collection point screenwash pressure fish testeda % Survivalb Source 

BOILI NE 

January- Co 11ection 

December pit

1976 

Discharge

pipe 

Janu ary- Co 11ection 

February pit 1977 

Discharge 

Pipe 

Continuous,

high pressure 

Continu ou s,

low pressure 

Intermittent, 

high pressure 

Intermittent,

low pressure 

Continuous, 

high pressure 

Cont inu ou s, 

low pressure 

Intermittent, 

high pressure 

Intermittent,

low pressure 

Cont i nu ou s, 

high pressure 

Cont inuou s, 

low pressure 

Cont i nuou s, 

h fgh pressure 

Continuous,

low pressure 

2483C 61 Ex h ib it UT-7 

Table 10.3-4 

3701C 49 

1339C 26 

1281C 23 

39OC 20 Exh ib it UT-7 

Table 10.3-6 

274c 17 

609.C 10 . 

366C 9 

958C 28 Exhibit UT-7 

Table 10.3-9 

988C 21 

25 29 

28 0 

-
@Table 6. (continued) 

Period Collection point 

BOWL1 N E tNovember- Co 1 1 ection 

December pit

E”’4 

January Co 1 1 ection 

pit 

April 1975 Co1 1 ection 

pit 

November- Discharge 

Pipe 

Pi’ -.March- Discharge 

Pipe 

1975 

Discharge 

*March 1975 Pipe 

Ir 

,March- D.ischarge

ril 1975 p,ipe 

ROSETON 

Fall 1975 CoI 1ection 

basket 

1-27 

Operating mode and 

screenwash pressure 

Conti nuous,

high pressure 

Conti nuous, high pressure 

Continuous. 

h igh pressure 

Continuous,

high pressure 

Continuous,

high pressure 

Intermittent, 

2- hr ho 1d , high pressure 

Intermittent,

4-hr hold,

high pressure 

Continuous,

high pressure 

Intermittent, 

2- hr ho1d , high pressure 

Intermittent, 

4- hr ho1d , high pressure 

Number of 

fish testeda % Survival Source 

837C 26 Exhib it UT-7 

Table 10.3-10 

678C 7 Exhib t UT-7 

Tab1e 10.3-10 

55c 35 Exhib t UT-7 

Table 10.3-10 

807c 23 Exhibit UT-7 

Table 10.3-11 

543c 7 Exhibit UT-7 

Table 10.3-11 

51 5 Exhibit UT-7 

Table 10.3-11 

Exh 1 it bUT-7 

Table 10.3-11 

201 Exhibit UT-6 

Table 10.3-3 

667 

239 
1-28 

Table 6. (continued) 

Operating mode and Number of 

Period Collection point screenwash pressure fish testeda % Survivalb Source 

ROSETON 

April- Co11ecti on 

June 1976 bask et 

April- Co1 1 ection 

June 1976 basket 

November- Co1 1 ection 

December basket 

1976 

Intermittent,

6-hr hold,

high pressure 

684 0 

Continuous, high pressure 

275 

(yearling

and adult) 

16 Exhibit UT-6 

Table 10.3-2 

Intermittent,

2-hr hold,

high pressure 

96 

(year1 i ng

and adult) 

9 Exhibit UT-6 

Table 10.3-2 

Intermittent,

4-hr hold,

high pressure 

(year1 ing

and adult) 

66 0 

Continuous,

low pressure 

285 44 Exhibit UT-6 

Table 10.3-4 

Continuous,

high pressure 

707 4 

Intermittent,

2-hr ho 1d,

low pressure 

389 8 

Intermittent,

2-hr hold,

high pressure 

344 5 

Intermittent,

4-hr ho1d , low pressure 

25 16 

Intermittent,

4-hr ho1d, high pressure 

70 0 
1-29 

8Table 6. (continued) -

Operating mode and 

eriod Collection point screenwash pressure 

Continuous, 

low pressure 

Continuous, 

high pressure 

Intermittent,

2-hr ho 1d , , low pressure 

' November - Co 11ecti on intermittent, hDecember bask et 2-hr hold, 1976 high pressure 

Intermittent,

2-hr hold, 

low pressure 

1. Intermittent, 

2-hr hold,

high pressure 

E)anuary- Co 11ect ion Con t inu ous , March 1977 basket low pressure 

Continuous, 

high pressure 

Intermittent, 

2 -hr ho 1d,

low pressure 

Intermittent, 

2-hr hold,

high pressure 

I 

I 

Number of 

fish tested" % Survivalb Source 

- 10 40 - -

(year 

9 0 

(Year 

22 14 

(yearling) 

9 11 Exhibit UT-6 

(yearling) Table 10.3-4 

7 (adult) 14 

4 (adult) 25 

15 0 EA 1977d 

Table 4-14 

49 0 

16 0 

39 0 
1-30 

Table 5. (continued) 

Period Collection point 

ROSETON 

Apri1 - Collecti on 

May 1977 basket 

April- Collection 

May 1977 basket 

1977 

Operating mode and 

screenwash pressure 

Continuous,

low pressure 

Continuous,

high pressure 

Intermittent,

2-hr hold,

low pressure 

Intermittent,

2-hr hold,

high pressure 

Intermittent,

4-hr ho1 d , low pressure 

Intermittent,

4-hr hold,

high pressure 

Continuous, 

low pressure 

Continuous,

high pressure 

Intermittent,

2-hr hold,

low pressure 

Intermittent,

2-hr hold,

high pressure 

Intermittent,

4-hr hold,

high pressure 

Number of 

fish testeda % Survivalb Source 

229 20 EA 1977 

Table 4-17 

378 51 

74 20 

68 23 

144 25 EA 1977 

Table 4-17 

231 10 

153 6 

(year1 ing) 

171 2 

(year1 ing) 

46 22 

{yearling) 

74 4 

(yearling) 

26 4 

(yearling) 
1-31 

Table 6. (continued) 

Operating mode and Number of 

Period Collection point screenwash pressure fish testeda % Survival Source 

ROSETON 

AprilMay 1977 

DANSKAMMER 

Fall 1975 

Continuous, . 89 (adult)

low pressure 

Continuous, 53 (adult)

high pressure 

Intermittent, 20 (adult)

2-hr hold,

low pressure 

Intermittent, 56 (adult)

2-hr hold,

high pressure 

Co11 ection Intermittent, 2 (adult)

basket 4- hr ho1 d,

low pressure 

Intermittent, 15 (adult)

4-hr ho 1d,

high pressure 

Collection Continuous? 268 

basket 

Intermittent, 

2-hr hold 

236 

Intermittent,

4-hr hold 

924 

Intermittent,

6-hr hold 

137 

11 

0 

15 

0 EA 1977 

Table 4-17 

18 

3 EA 1977. 

Table 4-25 

3 

0 

0 
Table 6, (continued) 

Period Collection point 

DAN SKAMMER 

kpril- Co1 1 ection 

May 1976 basket 

November- Co 11ection 

December basket 

1976 

DANSKAMMER 

April- Co 11ection 

May 1977 basket 

1-32 

Operating mode and screenwash pressure 

" Continuous 

Intermittent,

2-hr ho 1d 

Intermittent,

4-hr hold 

Continuous 

Intermittent,

2-hr hold 

Continuous 

Intermittent,

2-hr ho 1 d 

Continuous 

Conti nuous 

Intermittent,

2-hr hold 

Intermittent,

4-hr hold 

Continuous 

Number of b fish testeda % Survival Source 

99 

(yearling

and adult) 

71 

(year1 ing

and adult) 

41 

(year1 i ng

and adult) 

201 

258 

17 

(yearling) 

17 

(year1ing ) 

2 (adult) 

122 

29 

158 

248 

(year1ing ) 

21 EA 1977 

Table 4-26 

21 

0 

24 EA 1977 

Table 4-27 

9 

53 

6 

100 

43 EA 1977 

Table 4-34 

25 

6 

33 
1-33 

Table 6. (continued) 

Operating mode and Number of 

Period Collection point screenwash pressure fish testeda X Survival Source 

DANSKMER 

Intermittent,

2-hr hold 

162 

(yearling) 

40 

Intermittent,

4-hr hold 

62 

(yearling) 

0 

Continuous 347 (adult) 45 

Intermittent,

2-hr hold 

223 (adult) 28 

Intermittent,

4-hr hold 

137 (adult) 3 

SIJRY IVAL OF CONTROLS EXPOSED ONLY TO COLLECTION AND HOLDING PROCEDURE 

BOWLINE 

November- Co11ection 28 86 Exhibit UT-7 

December pit (year1 ing Table 10.3-5 

1976 and adult) 

302 32 

Discharge 134 14 Exhibit UT-7 

pipe Table 10.3-7 

ROSETON 

November- Co 11 ection 53 68 Exhibit UT-6 

December basket Table 10.3-6 

1976 

28 100 

(yearling) 

1 (adult) 100 
Table 6. (continued) 

Period Collection point 

ROSETON 

Apri 1 - Co1 1ection 

May 1977 basket 

DANSKAPWER 

November- Co 1 1 ection 

December basket 

1976 

April- Collection 

May 1977 basket ­

1-34 

Operating mode and Number of 

screenwash pressure fish testeda % Survival Source 

26 46 EA 1977 

Table 4-18 

22 59 

(yearling) 

230 (adult) 89 

11 91 EA 1977 

Table 4-28 

5 (adult) 100 

53 81 EA 1977 

Table 4-35 

38 79 

(year1ing ) 

159 (adult) 84 

aYoung-of-the-year unless otherwise noted. 

bPercent alive at end of observation period (96 hours at Bowline, 84 hours at Roseton and 

Danskanmer). 

CData collected under the same conditions (sampling point, operating mode, and screenwash 

pressure) are pooled. 

dEcological Analysts 1977 Progress Report to Central Hudson. 

eScreenwash pressure for all impingement survival studies at Danskamner is 55-65 psi. 
1-35 

Table 7. Sumnary of striped bass impingement survival data 

Operating mode and Number of 

Period Collection point screenwash pressure fish tested % Survivala Source 8 

BOWL1 NE 

January- Col 1ecti on 

December pit

1976 

November- Discharge

December Pipe sg7, 

November- Co 11ect ion 

k;;mber p'it 

Coll ect i on 

pit 

Co 11ecti on 

pit 

Conti nuou s , high pressure 

Conti nuou s,

low.pressure 

Intermittent, 

high pressure 

Intermittent, 

low pressure 

Conti nuou s , high pressure 

.Continuous, 

low pressure 

Intermittent, 

high pressure 

Intermittent, 

low pressure 

Continuous , high pressure 

Continuous,

high pressure 

Continuous, 

high pressure 

181b 62 Exhibit UT-7 

Table 10.3-4 

282b 49 

105b 32 

164b 14 

25b 40 Exhibit UT-7 

Table 10.3-6 

7b 14 

65b 24 

107b 6 

123b 11 Exhibit UT-7 

Table 10.3-12 

577b 9 Exhibit UT- 7 

Table 10.3-12 

158b 71 Ex hi b it UT-7 

Table 10.3-12 
3 -36 

Table 7. (continued) 

Operating mode and Number of 

Period Collection point screenwash pressure fish tested % Survivala Source 

BOWL1N E 

November- Discharge

December pipe

1974 

Apri 1 - Discharge

May 1975 Pipe 

March 1975 Discharge 

Pipe 

March- Di scharge 

April 1975 Pipe 

ROSETON 

Fall 1975 Co1 1ection 

basket 

Fall 1975 Co 1 1 ection 

basket 

Continuous,

high pressure 

Conti nuous,

high pressure 

Intermittent,

2-hr hold,

high pressure 

Intermittent,

4-hr hold,

high pressure 

Conti nuous,

high pressure 

Intermittent,

2-hr ho1d,

high pressure 

Intermittent, 

4-hr ho 1 d,

high pressure 

Intermittent,

6-hr hold,

high pressure 

Continuousc 

Intermittent,

2-hr hold 

Intermittent,

4-hr hold 

86b 19 Exhibit UT- 7 

Table 10.3-13 

192b 61 Exhibit UT-7 

Table 10.3-13 

50 5 Exhibit UT-7 

Table 10.3-13 

98b 0 Exhibit UT-7 

Tab1e 10.3-13 

4 25 Exhibit UT-6 

Table 10.3-3 

11 0 

5 0 

6 0 

3 0 EA 19774 

Table 4-25 

12 17 

26 0 
1-37 

Table 7. (continued) 

I 

Operating mode and Number of 

Period Collection point screenwash pressure fish tested % Survival" Source 

DANSKAMMER 

I .. lntermittent, 2 I - 0 .. . 

6-hr hold 

I SURVIVAL OF CONTROLS EXPOSED ONLY TO THE COLLECTION AND HOLDING PROCEDURE 

BOWLINE 

November- Co 1 1ection 35b 20 Exhibit UT-7 

[ Decernber pit Table 10.3-5 1976 

aPercent alive at end of observation period (96 hours at Bowline, 94 hours at Roseton and 1 Danskamner ). 

B 

bData collected under the same conditions (sampling point, operating, mode, and screenwash 

pressure) are poo 1 ed. 

CScreenwash pressure for all impingement survival studies at Danskamner is 55-65 psi. 

dEcoIogica1 Anislysts 1977 Progress Report to Central Hudson. 

- . 
1-38 

Table 8. Comparison of observed percent survival of white perch and striped bass under 

identical experimental conditions, Bow line Point Generating Station (from

Tables 6 and 71 

Period 

Co 11ecti on 

point 

Operating mode and 

screenwash pressure 

% Survival of 

white perch 

% Survival of 

str iped bass 

JanuaryDecember 

1976 

Collection pit Continuous,

high pressure 

61 62 

Continuous,

low pressure 

49 49 

Intermittent, 26 32 

high pressure 

Intermittent,

low pressure 

23 14 

Discharge pipe Continuous, 

high pressure 

20 40 

Cont inu ou s , low pressure 

17 14 

Intermittent, 10 24 

high pressure 

Intermittent,

low pressure 

9 6 

NovetnberDecember 

1974 

Collection pit Cont inuou s,

high pressure 

26 11 

January 1975 Collection pit Conti nu ou s , high pressure 

7 9 

April 1975 Collection pit Continuous,

high pressure 

35 71 
Table 8. (continued) 

Co 1 1 ection 

Period point I 

November - Discharge pipe Continuous,

h i gh pressure I Oe~:er 1974 

March- Discharge pipe Continuou5, 

high pressure IMay 1975 

March 1975 Discharge pipe Intermittent,

2-hr ho 1 d , high pressure I 

Discharge pipe Intermittent, 

4- hr ho1 d , high pressure 

1-39 

Operating mode and 

screenwash pressure 

% Survival of % Survival of 

white perch striped bass 

23 19 

61 

5 

0 0 

I Student's t (13 df) = 3.02 P < 0.01 

I 

I 

I 

I 

I 

I 

I 

I 

1 

.I 
-- 

1-40 

survival or high2r. But in many of the experiments, in particular in the 

April -1vlay 1977 experiments at Roseton, survival of white perch impinged

during intermittent operation viith a two-hour wash cycle has Seen as high a 

w higher than that of fish impinged during continuous operation. The lowe 

white perch survival at both Roseton and Danskamer has been observed durin 

intermittent operation with a four-hour cycle. 

The results of tests designed to measure the effect of screenwash 

pressure on survival have also differed from plant to plant. As was noted 

in ow discussion of Atlantic tomcod survival, "low'' pressure at Roseton 

i30 psi) is nearly as high as "high" pressure at Bowfin? (50 to 60 psi). Most of the t2sts at Roseton have indicated that under'both continuous and 

intermittent operation white perch survival is higher at 50 psi screenwash 

pressure than at 100 psi. EA has stated this conclusion both in Exhibit 

UT-6 (p. 10.3-35) and in the 1977 Progress Report to Central Hudson 

(Ecological Analysts 1977, p. 5-1). 8ased on the data in Table 6, I agree

with this conclusion. 

At Bowline, no increase in survival has been noted when screenwash 

pressure is reduced from the normal 60 psi to 20 psi or less. EA found no 

significant gffxt of pressure on survival under either continuous or 

intwnittent travelling screen operation. EA offered two possible

explanations (Exhibit UT-7, pp. 10.3-26-28): 

... The absence of. an apparent effect of screenwash pressure has at least two possible interpretations. First, the damage

incurred by th2 white perch from being washed off the screens 

may be negligible at screenwash pressures of 50-60 psi and 

below. Second, the spray from the low pressure system may have 

been insufficient to remove fish from the screens. As a 

result, the fish may have been exposed to the high pressure nozzles located just above the low pressure system. In this 

case pressure exposures would have been similar in both the low 

and high pressure wash tests. 

A1 shx~gbEA found no statistically significant difference, the 

Jan2ary-December 1976 survival percentages in Table 8 suggest that the 

1w-pressure screenmsh system may actually reduce the survival of white 

aerch and striped bass. In eight cases in which it is possible to compare

r-esul ts obtained under conditions that :vere identical except for screenwash 

pressclre (i.e., same collecting location, screenwash schedule, and species), 

h:gna- survival vias observid in every case among fish exposed only to the 

hign 9ress.m spray. If screenwash pressure has no effect on survival, ther 

the pcobability of this result is the same as the probability of tossing a 

coin eight times and observing eigh "heads." Such a result would be 

expected by chance only 0.4% f= 0.5 Ej ) of the time. 

Xeitnsr LA nor Lt4S nas evw reported designing or conducting experiment 

in order to determine ðer the survival of impinged white perch and 

striped b3;s v,arizs seasonally. Nonetheless, the data in Tables 6 and 7 

sqgest that such variation does exist. In tests performed during the winte 
1-41 

of 1977 (January-March), EA observed 100%mortality of jilvenile white perch

under all operating conditions- EA'S explanation (Ecological Analysts 1377, 

p. 4-25) was that these fish are more susceptible to handling and holding 

stresses wlhen water temperatures are near freezing. I agree that since young Nhite perch already are under stress because of low temperatures, they should 

be more vulnerable to the additional stress of handling and observation. 

However, for the exact same reason, they should also be more susceptible to 

the stress of impingement. Survival of white perch impinged at i3owline 

during this same period was also low (Table 6). Nearly 2000 impinged white 

perch were sampled at the Bowline collection pit during January-February

1977. All were obtained while the screens were operating in the corltinuous 

mode, i.e., the mode under which the highest survival is obtained. Only 23% 

of the fish collected when the high pressure spray was used, and mly 21% of 

the fish Collected when the low pressure spray was used, survived for as 

long as 96 hours after collection. Relatively 3igh survival was observed 

among white perch collected at the Bowline discharge pipe (high pressure

spray), but the sample size here was low, only 25 fish. Few impinged striped

bass have been collected and observed during the winter. Table 10.3-4 Df 

Exhibit UT-7 lists 35 striped bass as having been collectsd in Jancrary and 

February of 1976. O~ly4 of these (11%)survived for 96 hours. Of 158 

striped bass collected by LMS in January 1975, 71% survived for a similar 

period. The results for striped bass are contradictory and no reasonable 

conclusions can be drawn from them. The results for white perch suggest, although they are not conclusive, that survival is lower during the winter 

than during other seasons. 

It is now time to address the thorny question of the reliability of the 

data sumnarized in Tables 6-8 as estimates of the survival of those white 

perch and striped bass that are impinged, washed off the screens, and 

returned to the river .rather than collected and observed. It is not possiJle 

to reproduce in the laboratory the conditions faced by these fish in their 

natural habitat. A stunned or otherwise weakened fish is more vulnerable to 

predators, and these predators may congregate in the vicinity of the 

screenwash discharge because it provides an abundant supply of prey.

Congregations of predators 'nave, in fact, been observed at fish return sites 

in the Sacramento-San Joaquin estuary (Skinner 1972, Cal iforni a Department

of Fish and Game et al. 1978). Noreover, analyses of the stoiaach contents 

of these predators indicate that they feed heavily on released fish (Skinner

1972, California Department of Fish and Game et al. 1978). A fish that 

survives these predators may develop fungal or bactsri a1 infections bzcause 

of wounds and/or lost scales caused by impingement. Such infections may 

not be observable in the holding facility because they take longer than 96 

hours to develop, or because they are suppressed by biocides (according to 

p. 10.3-6 of Exhibit UT-6, water used at the Roseion holding facility has 

occassionally been treated with potassium permanganate in order toreduce 

the i nci deiice of inf ecti ons ) . 

On the other hand, the collection and holding procedure imposes stresss 

of its own that the impinged fish does not suffer if it is returned directly 

to the river. It is for this reason that EA has attempted to measure the 
1-42 

mortality of control fish, exposed only to collection and holding, at all 

three plants. The cofitrol survival data for striped bass and white perch 

are sumarized, respectively, in Tables 6 and 7. 

EA's results indicate that for both of these species handling mortality

is substantial. The survival of vhite perch and striped bass controls at 

Bowline has been no better than that of the comparable impinged fish. 

Survival of impinged striped bass sampled at the collection pit in 1976 

ranged from �4 to 62%- Survival of the corresponding control fish was 32%. 

Survival of yearling and adult Aite perch controls was high (86%), but ther 

are no impinged fish with which they can be compared. White perch survival 

at the Bowline discharge pipe in 1976 ranged from 9 to 20%. The corresponding control survival was 14%. White perch controls at Roseton and 

Danskamer have fared better, although mortality has been fairly high among

young-of-the-year controls. In only one case (Roseton, April-May 1977,

young-of -tr?e-year, continuous high-pressure screenwash) has mortal ity among

impinged fish been higher than that of control fish. 

Is it possible that all of the observed mortality among impinged fish 

is caused by collection and handling? I do not believe so. If all mortalit 

were due to collection and handling, then no effects of screenwash procedure 

on survival could be observed. If, as appears to be the case, collection 

and holding cause substantial mortality, then EA's prccedure ensures that 

control fish will suffer more of this mortality than will impinged fish. 

According to p. 10.3-18 of Exhibit UT-?, control fish are held for at least 

72 hours before use in impingement survival experiments. If the holding 

system stresses fish, thetl controls are exposed to this stress for much - longer than are impinged fish. It may, however, be the collection process . itself that imposes the stress. Dr. Jinks stated (transcript p. 4599) that 

the length of time spent in the collection basket influences the survival of 

ccntrof fish. At all three plants control fish are inserted into the 

coliection device at the beginning of the sampling period and left there for 

the entire sampling period (transcript pp. 4598-99). If impinged fish arriv 

in the net more or less continuously throughout the sampling period, then . . each control fish is exposed to the stress of collection for twice as long 

as the average impinged fish. In addition, control fish suffer a stress 

that is not imposed at all on impinged fish: stress due to marking. TI has 

found (trdnscript, pp. 4597-98) that marking does induce mortality. TI'S 

mark/recapture population estimates are adjusted to account for this 

mortality. EA has net attempted to measure the effect of marking on the 

survival of control fish used in impingement survival studies. 

Because control fish suffer more collection, handling (including rriarking), and holding stress than do impinged fish, I do not believe that 

the mortality of the control fish is a reliable measure sf the true 

sampling/observation mortality suffered by impinged fish. The control 

survival percentages should not be used to compute adjusted impingement survival percentages (e-g., as is done in Table 10.3-7 of Exhibit UT-6). It 

may be concluded that the results tabulated in Tables 6-8 represent overestimates of the actual fraction of impinged white perch and striped bass 

6 
1-43 

that die as a direct result of being impinged. However, an additional 

fraction, one that cannot be estimated at this time, probably die indirectly

because of increased vulnerabi 1ity to predators or pathogens. 

2.5 COMPARISON BETWEEN IMPIMGEMENI SURVIVAL AND COLLECTION EFFICIENCY 

Is the percent survival of Atlantic tomcod, clupeids, white perch, or 

striped bass impinged and returned to the river under normal operating

conditions high enough to offset the effects of collection efficiency? I 

believe that for Atlantic tomcod impinged at Bowline, Roseton, and 

Danskamner, the answer to this question is "yes." For clupeids the answer 

is definitely "no," and for white perch and striped bass it is "probably 

yes. 'I 

Survival of adult Atlantic tomcod impinged during the fall and winter 

is clearly high enough to offset the effects of collection efficiency.

Except for the anomalously low survival observed at Roseton and Danskamner 

in 1975, the survival of these fish has been very high. In experiments in 

which 10 or more fish have been collected, at least 70% have survived to the 

end of the observation period. Fall and winter impingement estimates for 

this species must be scaled down to account for this high survival. Based 

on the scant evidence available to date, the survival of juveni-le Atlantic 

tomcod impinged at Bowline, Roseton, and Danskamner during the sumner months 

appears to be high enough to offset collection efficiency, but not so high

that downward adjustments are judged to be required. 

The survival of impinged clupeids at the three plants discussed in this 

section appears to be virtually zero, and thus, collection efficiency is not 

at all offset. 

For wlhite perch and striped bass my conclusions are more uncertain. 

The highest survivals of these species at all three plants have been obtained 

under continuous travelling screen rotation and, at least at Roseton, low 

screenwash pressure. These are' not the standard operating conditions at any

of these plants (Table 3). At Roseton and Danskamner, the most relevant 

results in Tables 6-8 are those obtained from experiments conducted under 

intermitteint screenwash with the high-pressure spray. Survival percentages

under these conditions have ranged from 0 to 25% at Roseton and from 0 to 

40% at Danskamner. During conditions of high debris loading or icing, the 

travelling screens at Roseton are rotated continuously and washed with the 

high pressure spray. The survival percentages obtained under this operating

mode have ranged from 0-51%. At Bowline, both intermittent and continuous 

rotation have been employed during normal operation. Survival percentages ranging from 0 to 71% have been obtained from the collection pit experiments,

with most of the observations fallins between 10 and 40%. The qenerally

lower survivals obtained at the Bowlrne discharge p pe are 1argGly a function 

of sampling mortality, as evidenced by the relative y poor surviva of the 

discharge pipe controls. 
r -44 

Given that a substantial fraction of the mortality observed among whi 

perch and striped bass is caused by collection and/or observation, it is 

conceivable that as many as 40% may survive the imnediate effects of 

impingement if returned directly to the river. At all three plants

impingement abundance collections are made at least once a week. On these 

days no fish are returned to the river. Moreover, it is normal procedure

Bowline to hold all fish impinged during the 24 hours preceding an 

impingement sample. If, on the average, 40% of the fish returned to the 

river.survive, then about 29% (40% x 5/7) of all white perch and striped bass impinged at Bowline during a week would survive. At Roseton and 

Danskamner, about 34% (40% x 6/71 would survive. These survival percentag 

are enough to offset the effects of collection efficiency (70 to 75%) so 

that no adjustments of the white perch and striped bass impingement totals 

need be made. 

The possibility remains that survival of impinged striped bass and wh 

perch may be lower during the winter, a season of high impingement at Bowl 

and Indian Point and of low impingement at Roseton and Danskamer. It is 

also possible that, due to the effects of sampling mortality, the survival 

of these species may be higher than is indicated by the results of the 

experiments. However, bi ases i ntroduced i nto the direct impact assessment 

by underestimating or overestimating the survival of impinged white perch and striped bass at Bowline, Roseton, and Danskamner are likely to be smal 

in comparison to biases introduced by errors in the estimates of populatio

size and total mortality. 

It can be seen from Table 3 that travelling screen operating conditio 

at Albany are similar to those at Bowline, Roseton, and Danskamer. 

Therefore, it seems reasonable to assume that the survival of impinged fis 

at this plant is probably similar to that observed at the three plants whe 

studies have been conducted. At Lovett, however, the screens are rotated 

only once every eight hours. Since reduced survival has been observed at 

other plants when a four-hour screenwash cycle is employed, it is reasonab 

to suppose that survival would be even lower with an eight-hour cycle. In 

the absence of data relating to the mortality of impinged fish at Lovett, 

assume zero survival of all species at this plant, and thus, collection 

efficiency is not at a1 1 offset. 
1-45 

3, CONCLUSIONS 

I conclude, on the basis of an analysis of the four potential biases 

discussed in Section 2, that the impingement estimates for some species at 

some plants require adjustment. Table 9 summarizes my estimates by plant and species of the magnitude of biases associated with collection efficiency, reimpingement, impingement on inoperative screens, and impingement survival. 

Any adjustment factors that I believe are necessary are also presented in 

Table 9. Since the various biases, in particular those due to impingement

survival, cannot be measured precisely, I have chosen to adjust the 

impingement totals only in cases where there is a clear imbalance between 

those biases that cause underestimates (collection efficiency and impingement 

on inoperative screens) and those that cause overestimates (reimpingement

and impingement survival). I have applied adjustment fdctors only if a 

change of 20% or more in the impingement estimates would result. Adjusting

these estimates by smaller amounts is, in my opinion, attributing greater 

accuracy and precision to the bias measurements than they actually possess. 

No estimates of collection efficiency are available for Danskamner, and 

no estimates of any of the biases are available for Lovett or Albany. In 

these cases I have estimated the magnitude of the biases from the data 

obtained at other plants, primarily Roseton and Indian Point Unit 3. Like 

Roseton and Indian Point (and unlike Bowline), Danskamner, Lovett, and Albany withdraw cooling water directly from the river. As it seems most probable that the slightly higher collection efficiency and reimpingement observed at 

Bowline are related to the unique intake configuration of that plant, we 

have assumed that the estimates of collection efficiency at Roseton and 

Indian Point Unit 3 (both about 70%) and of reimpingement at Roseton 

(essentially zero) are applicable to these other three plants. The low 

collection efficiency at Indian Point Unit 2 is undoubtedly caused by the 

presence of fixed screens in front of the travelling screens, a configuration

that exists at no other plant on the Hudson River (except for Indian Point 

Unit 1, which is not presently operating). 

Travelling screen operating procedures at Albany appear to be simi lar 

to those at Bowline, Roseton, and Danskamner; therefore, I assume that the 

same estimates of impingement survival are applicable. At Lovett the screens 

are rotated only once every eight hours. On the basis of the observed 

inverse relationship between impingement survival and travel ling screen 

holding time, I assume that no fish survive impingement at Lovett. Since 

fish impinged at Indian Point are not returned to the river, no survival is 

poss i b 1e. 

I believe that upward adjustment is required for clupeid impingement estimates at all plants and for impingement estimates for all specierat Lovett and Indian Point. My adjustment factor for Indian Point Unit 3 is 

slightly higher than that used by the utilities because my estimate of 

collection efficiency is lower. My adjustment factor for Indian Point 

Unit 2 is identical to that of the utilities. I believe that estimates of 
-- 

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-- 

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1-46 

Table 9. Adjustment factors derived for impingement estimates at Hudson River power plants 

Impinqement survival Adjustment factora,b 

Co 11ection May- September- May- September- Plant efficiency Reimpingement August Apri 1 August Apri 1 

ATLANTIC TOMCOD . 

Bonline 0.75 0.1 0.4 0.7 0.6 

Lovett 0.70 0 0 0 1.4 1.4 

IP unit 2 0.15 0 0 0 6.7 6.7 

IP unit 3 0.70 0 0 0 1.4 1.4 

Aoseton 0.70 0 0.4 0.7 . 0.6 

Danskamner 0.70 0 0.4 0.7 00 0.6 

Albany

(1974- 75) 0.70 0 0.4 0.7 0.7 

Albany

(I975- 76) 0.70 0 0.4 0.7 0.5 

CLU PE1DS 

Bwline 0.75 0.1 0 

Lovett 0.70 0 0 1.4 

IP unit 2 0.15 . 0 0 6.7 

IP unit 3 0.70 0 0 1.4 

Roseton 0.70 0 0 1.4 

Danskamner 0.70 0 0 1.4 . 

Albany 0.70 0 0 1.4 

WHITE PERCH AND STRIPED BASS 

Bowline 0.75 0.1 0.4 

Lovett 0.70 0 0 1.4 

IP unit 2 0.15 0 0 6.7 

IP unit 3 0.70 0 0 1.4 

Roseton 0.70 0 0.4 

Danskamner 0.70 0 0.4 

Albany 0.70 0 0.4 

aAdjustment factor = (I/coIlection efficiency) x (I - reimpingement) x (1 - impin ement 

survival x the fraction of days on which impinged fish are returned to the riverq. For 

Bowline this fraction is equal to 5/7, since impinged fish are collected and held for 24 

hours prior to each weekly impingement collection (Exhibit UT-7). For Roseton and 

Danskemner, it is equal to 6/7, since there is no 24 hour prewash prior to each week's 

sampling (Exhibit UT-6). For Albany, this fraction is equal to 5/7 for the period April

1974-March 1975, sirice impingement collections were made tw.ice per week. For the period

April 1975-March 1976, it is equal to 13/14, since impingement collectinns were made only 

once every bo weeks (Lawler et al. 1976b). 

bAdjustment factors are actually applied to the impingement estimates only if a change of 

20% or more would result, that is only adjustment factors less than or equal to 0.80 or 

greater than or equal to 1.20 are applied. 
1-47 

1 fa71 and winter impingement of Atlantic tomcod at Bowline, Roseton,

Danskamner, and Albany require downward adjustment because of high

survival. Survival of younger tomcod impinged during the warmer months is 

apparently 'lower, and therefore, I apply no adjustment to impingement estimates for the months of May-August. 8 
1-48 

4. REFERENCES 

California Department of Fish and Game, Cafifornia Department of Water 

Resources, U.S. Fish and Wildlife Service, and U.S. Bureau of 

Reclamation. 1978. Interagency Ecological Study Program for the 

Sacramento-San Joaquin Estuary. Sixth Annual Report (1976). 

Ecological Analysts, Inc. 197.7. Impingement survival studies at the 

Roseton and Danskammer Point generating stations. Progress report

prepared for Central Hudson Gas and Electric Corporation. 

Exhibit EPA-96. Response by Orange and Rockland entitled "Attachment F,

Impingement, Bowline Question I. Screen collection efficiency

studies. Bowline Point Generating Station, October 1976-June 1977." 

Exhibit EPA-97. Response by Central Hudson entitled "Set A-15 impingement

collection efficiency results for the Roseton facility for the period

January-March 1978." 

Exhibit EPA-198. Boreman, J. 1979. Life-histories of seven fish species

that inhabit the Hudson River estuary. Testimony before the U.S. 

Environmental Protection Agency, Region 11. 

Exhibit UT-3. Supplement I to influence of Indian Point Unit 2 and other 

steam electric generating plants on the Hudson River estuary, with 

emphasis on striped bass and other fish populations. Edited by J. T. 

McFadden and J. P. Lawler. Submitted to Consolidated Edison Company of 

New York, Inc, July 1977. 

Exhibit UT-6. Roseton Generating Station. Near-field effects of 

once-through cooling system operation on Hudson River biota. Central 

Hudson Gas and Electric Corporation. July 1977. 

Exhibit UT-7. Bowline Point Generating Station. Near-field effects of 

once-through cooling system operation on Hudson River biota. Orange

and Rockland Utilities, Inc. July 1977. 

Exhibit UT-105. 'Summary of collection efficiency tests and related 

95 percent confidence intervals at Indian Point Units 2 and 3. 

Exhibit UT-113. Impingement collection efficiency, Bowline Point Generating

Station, 1936 through 1978. 

Exhibit UT-114. Recovery rate of tagged fish by unit and -travelling scree,

Bowline Point Generating Station, 1976-1978. 

Exhibit UT-115. Summary of collection efficiency studies, Bowline Point 

Generating Station, 1976-3978. 

Huggins, T. 1977 (pers. comm.). Letter to H. Gluckstern of EPA, dated 

November 29, 1977. 
1-49 

Lawler, Matusky, and Skelly (LMS). 1974. 1973 tludson River aquatic

ecology studies at Roseton and Danskammer Point. Prepared for Central 

Hudson Gas and Electric Corporation. 

Lawler, Matusky, and Skelly (LMS). 1975. Albany steam electric generating

station impingement survey (April 1974-March 1975). Prepared for 

Niagra Mohawk Power Corporation. 

Lawler, Matusky, and Skelly (LMS). 1976a. 1975 Hudson River aquatic ecology

studies - Bowline Point and Lovett Generating Stations. Prepared for 

Orange and Rockland Utilities, Inc. 

Lawler, Matusky, and Skelly (LMS). 1976b. Albany Steam Electric Generating

Station, 316(a) Demonstration Submission, NPDES Permit NY 0005959. 

Prepared for Niagra Mohawk Power Corporation. 

Marcellus, K. 1977 (pers. corn.), Letter to H. Gluckstern of EPA,

dated November 30, 1977. 

Skinner, J. E. 1972. Fish protective facilities. Chapter 11 in Ecological

Studies of the Sacramento-San Joaquin Estuary. Decennial Report

1961-1971. California Department of Fish and Game. 

Texas Instruments. 1974. Indian Point impingement study report for the 

period 15 June 1972 through 31 December 1973. Prepared for 

Consolidated Edison,Companyof New York, Inc. 

Texas Instruments. 1975. Indian Point impingement study report for the 

periold 1 January 1974 through 31 December 1974. Prepared for 

Consolidated Edison Company of New York, Inc. 

Texas Instruments. 1976. Indian Point impingement study report for the 

period 1 January 1975 through 31 December 1975. Prepared for 

Consolidated Edison Company of New York, Inc. 

Texas Instruments. 1977a. Hudson River ecological study in the area of 

Indian Point. 1976 Annual Report. Prepared for Consolidated Edison 

Company of New York, Inc. 

Texas Instruments. 1977b. 1974 year-class report for the multiplant impact

study of the Hudson River estuary. Prepared for Consolidated Edison 

Company of New York, Inc. 

c 
CHAPTER I1 

EVALUATION OF IMPINGEMENT LOSSES OF WHITE PERCH 

AT HUDSON RIVEft POWER PLANTS 

TESTIMONY OF 

'I W. VAN WINKLE, Ph.D. 

HEAD, AQUATIC ECOLOGY SECTION 

1 and 

I L. W. BARNTHOUSE, Pil.D. 

1 

ENVIRONMENTAL SCIENCES DIVISION 

OAK RIDGE NATIONAL LABORATORY 

OAK RIDGE, TENNESSEE 

I 

Environmental Sciences Division I Publicaton No. 1932

I 

8 

I 

I 

I 

I' 

PREPARED FOR THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION I1 

I 
SUMMARY AND CONCLUSIONS 

This testimony pres ts two independent lines f evidence evaluating

impingement losses-of white perch at the power plants on the Hudson River. 

The first l'lne of evidence involves analyzing the variation in collection 

rate among years over the period 1972 - 1977, The second line of evidence 

involves estimating the conditional mortality rate (or equivalently, the 

percent reduction in year-class strength in the absence of compensation) due 

to impingement for the 1974 and 1975 year classes. 

The collection rates provide estimates of year-class strength on a 

relative scale. As such, they reflect the effect of entrainment and 

impingement losses during the preceding months, as well as the effect of any 

compensatory mechanisms which might alter survival during the preceding

months. Regression analyses on collection rates of impinged

young-of-the-year white perch among years suggest that there has been no 

systematic change in the size of the white perch population during the 

period 1972 - 1977. In particular, there is little evidence of a 

statisticallly significant downward trend. However, given the large variability in collection rates used in these regressions, the time series 

are relatively short (i.e., 5 to 6 years), and thus, the statistical power

of the test for a trend is not high. In addition, because of the age of 

sexual maturity for females and the multiple age-class composition of the 

spawning population of females, and because impingement mortality increased 

appreciably starting in 1973 and 1974, a systematic decrease in year-class

strength due to impingement mortality would only start to manifest itself 

with the 197'7 (or 1978) and subsequent year classes. 

Our estimates of percent reduction in year-class strength due to 

iinpi ngeinent indicate that the 1eve1 of impingement impact was probably 

greater than 20% for the 1974 year class and was probably greater than 15% 

for the 19751year class. These estimates do not include consideration of 

entrainment, so that the total power plant conditional mortality rate is 

obviously greater than the values presented in this testimony for impingement

only. Given the information presently available, it is our judgment that 

this level of impingement impact is not acceptable from the point of view of 

the white perch population. 

In terms of the comparability of assumptions and values for input 

parameters used in the utilities' methodology and in ORNL's methodology, the 

utilities' estimate of percent reduction due to impingement for the 1974 

year class of 11.3% is best compared to ORNL's estimate of 25,5%, Five 

reasons for this more than factor-of-two difference are discussed. The 

utilities' choice at every one of these five "decision points" affects the 

results in the same direction, namely, to lower the estimate of percent

reduction. ORNL's choice at each of these five decision points is 

scientifically more sound and defensible. 

I 

Preceding page blank1 11-iii 

- .._ ._ 
CONTENTS 

1 Page

PUMMARY AND Corw-usIoMs ...................... 11-iii 

1. Introduction ....................... f 

2 . White Perch Impingement Data .... ...... ......... 2 

A . Description of data base ............... B . \lariation in collection rate among years ....... C. Variation in collection rate among months ...... D . Variation in collection rate among power plants ... 8 3 . White Perch Abundance and Mortality ............ 9 

A . Abundance ...................... 9 

B . Mortality ...................... 12 

a 4. Estimation of Conditional Mortality Rate and 

Exploitation Rate Due to Impingement ........... 15 

5. Discussion ......................... 21 

A . Comparison with utilities' results .......... 21 

B . I[s there a problem? ................. 23

I 6. References ........................ 25 

Impingement Data Base .................. 2 7 liippendix. 

. 

Preceding page bfank 11-v 

..... 
-- 

LIST OF TABLES 

Mble 

17 

8 

0 

Page 

Summary of results from regression analyses to examine the 

time series of collection rates for trends in the Hudson 

River young-of-the-yearwhite perch population ........ 11-4 

Variation in mean collection,rate of young-of-the-year ,_ 

white perch among months and among power plants ....... 6 

Variation in mean collection rate of yearling and older 

white perch among months and among power plants ....... 7 

Estimates of white perch juvenile-abundancein the 

Hudson River .......................... 10 

Catch-curve estimates of white perch mortality based on 

bottom trawl data from the Bowfine Point vicinity,

1971-1976 .......................... 13 

Initial population sizes and mortality estimates used in 

the empirical model of impingement impact to estimate the 

conditional mortality rate and exploitation rate due to 

impingement for the Hudson River white perch population . . 16 

Month1.y estimates of the number of white perch impinged 

at all the Hudson River power plants combined for the 

1974 and 1975 year classes .................. 17 

Estimates of conditional mortality rate and exploitation 

rate (in parentheses) due to impingement for the 1974 and 

1975 year classes of the Hudson River white perch population for combinations of estimates and assumptions

involving initial population size, natural mortality,

and number of years of vulnerability ............. 19 

Relevant parts of Table 2-WfH-1 in Exhibit UT-3 ....... 22 

White perch impingement data for the Albany Steam 

Electric Generating Station ................. 29 

White perch impingement data for the Astoria Generating 

Station (Ref. 1) ....................... 33 - White perch impingement data for the Bowline Point 

Generating Station ...................... 36 

Preceding page blank II-vii . 
Table Page 

A-4 klhite perch impingement dhta for the Danskammer Point 

Generating Station . . . . . . . . . . . . . . . . . . . . . 39 

A-5, White perch impingement data for Indian Point Units 1, 

6817 2,and3 ........................... 43 

A- 8 White perch impingement data for the Lovett Generating

Station . . , -. . . , . . . . . . . . . . . . . . . . . . . 50 

A-9 White perch impingement data for the Roseton Generating

Station . . . . . *. . . . . . . :. . . . . . . . . . . . . 53 

A-10 "DIVISION" criteria specified by Texas Instruments as the 

cut-off length between young-of-the-year and yearling

white perch . ' . . . . . . . . . . . . . . . . . . . . . . . 57 

11-viii 
-- 

1. INTRODUCTION 

Oak Ridge National Laboratory (ORNL) performed a preliminary evaluation 

of impingement losses of white perch at the Indian Point Nuclear Station and 

other Hudson River power plants in preparing the Final Environmental 

Statement for Indian Point 3 (USNRC 1975). In that evaluation we stated 

A 1973 field-tagging study by a consultant for the applicant

indicates that the September-October population estimates to be 

used for planning purposes should be 23 million white perch for 

the entire Hudson River. This population estimate includes all 

age groups and not just young-of-the-year,but the young-of-theyear account for the majority of the white perch impinged. This 

populaition estimate is tentative, it may vary by an order of 

magnitude from year to year, and it is based on 1973 data (whereas

the impingement estimates are based on 1971-1972 data);

nevertheless, the staff feels that impingement may have a 

significant impact on the white perch population. For example,

the projected total impingement loss at all plants with 

once-through cooling at the three Indian Point Units is 4.1 

million white perch per year. If the assumptions are made that 

these are all young-of-the-year and that 80% of the total white 

perch population of 23 million are young-of-the-year, then 20% to 

25% of' these young-of-the-year white perch will be impinged.

(p. V-61) 

In response to the above concern, the Office of Nuclear Regulatory

Research, W. S. Nuclear Regulatory Commission, funded research at ORNL 

starting in May 1978 with the following objectives: To determine the 

significance of impingement losses on the white perch population at the 

Indian Point Nuclear Station (all units). To collect, compile, and analyze

data and information on white perch impingement losses in the Hudson River. 

To estimate the impingement exploitation rate by power stations and the 

conditional rate of mortality due to impingement for the Hudson River white 

perch population. To document in a final report the results -ofthe analysis

and to make! a determination whether the impingement losses are having a 

potentially adverse impact on populations of white perch in the Hudson River. 

This report is organized as follows: Section 2 deals with the white 

perch impingement data per se, including a description of the data base and 

the analyses of variations in the collection rates among years, months, and 

power plants. Section I11 deals with white perch population data, including

estimates of population size and monthlyxnatural mortality rates. Section IV 

integrates the results from Sections 2 and 3 to estimate the conditional 

mortality rate and exploitation rate due to impingement, using the GRNL 

empirical impingement model. Section 5 is a discussion of our results in 

light of the utilities' results and concludes with consideration of whether 

impingement of white perch at Hudson River power plants is a problem. 

11-1 
11-2 

2. WHITE PERCH IMPINGEMENT DATA 

In this section, we first present a brief description of the data base 

on number of white perch impinged (collected) and on the collection rates at 

each power plant. Then, we present the results of our analyses of these 

coliection rates, focusing on the pattern of variation among years, months,

and power plants. Our analysis of the variation in collection rate of 

young-of-the-year white perch among years addresses the question of whether 

there has been a statistically significant and systematic trend in the size 

of year classes during the period 1972 - 1977. Our analysis of the 

variation in collection rate among months focuses on how these variations 

depend on location of the power plant and age of the white perch. Finally, 

our analysis of the variation in collection rate among power plants focuses 

on identifying which power plants have the highest and lowest collection 

rates and how the rankings of power plants depend on the age of the white 

perch impinged. 

A. Description of the Data Base 

Data on number collected and collection rate have been compiled for 

white perch by month for all years for which data were obtainable for each 

of the following power plants (moving downriver): Albany, Danskammer,

Roseton, Indian Point Units 1, 2, and 3, Lovett, Bowline, and Astoria. 

These data are presented in the Appendix, Tables A-1 through A-9. 

Collection rate is defined as the number of impinged white perch counted 

(Indian Point) or estimated (all other power plants) to be impinged at the 

intake per unit intake flow. Except for Indian Point, where collection 

rates were adjusted upward to correct for less than 100% collection 

efficiency, collection rate is assumed to be approximately equivalent to 

impingement rate, which is defined as the number of white perch killed at 

the intake per unit intake flow. A detailed analysis of factors that 

influence impingement estimates at Hudson River power plants is given in 

Exhibit EPA-205, including adjustment factors. We designated May 31 - June 

1 (a one-day interval) as the dividing line between 12-month old 

young-of-the-year and 13-month old yearlings. 

B. Variation in Collection Rate Among Years 

Collection-rate data are available on a monthly basis for a period of 

4-6 years for Bowline, Lovett, Indian Point 2, Roseton, and Danskamer. We 

have treated collection rate, which is equivalent to a catch per unit effort 

(CPUE), as an approximate index of population size. In order for a CPUE 

index to serve as an accurate index of popu’lation size, there must be some 

assurance that actual variations in effort are measured. We believe that 

data on power plant intake flow (= effort) satisfies this condition, since 

the uncertainty associated with estimates of intake flow is relatively

small. Given this assumption, we have examined the time series of 

collection rates over years for trends in population size. The regression 
11-3 

model used was Y = a + bX, where Y is the collection rate for young-of-theyear (yoy) white perch (RATE0 in Appendix), X is year, a is the Y-axis 

intercept, and is the slope. A slope (b) significantiy greater than 0.0 

(P < 0.10) suggests an increasing trend over years in population size, while 

a s'iope significantly less than 0.0 suggests a decreasing trend in population size. A slope not significantly different from 0.0 indicates that, although

year-class strength may have varied, there was no systematic trend in 

year-class strength over the period 1972 (or 1973) - 1977. The regression analysis was performed for each of the above five power plants and for all 

five power plants combined for each month separately. The reason for 

performing individual regressions for each power plant and month was to 

examine the possibility that there might be consistent patterns of variation 

at a power plant for certain months which were masked by averaging over power plants or over months. The regression analysis was also performed using the 

mean annual collection rate, which was calculated as the average of the 

twelve monthly collection rates for each year. In all, 78 regressions were 

performed. Because the twelve monthly collection rates are used to calculate 

the mean annual collection rate for each year, however, this set of 

regressions cannot be treated rigorously as a set of 78 statistically independent regressions. 

The results of these regression analyses are presented in Table 1. 

Of the 78 regressions, the slope (b) differs significantly (P < 0.10) from 

0.0 in only 8 cases. Of these 8 czses, the slope is significantly greater

than 0.0 seven times and less than 0.0 only once (Lovett, in March). In our 

judgment the mean annual collection rates for each of the five power plants

and for all five plants combined are likely to be more reliable indices of 

population size than the monthly collection rates, which are more subject to 

variation from year to year due to temperature or salinity differences, and 

consequently, to differences in the spatial distribution of yoy white perch

in the Hudson River, rather than due to real differences in year-class strength. None of the slopes for the six "annual" regressions differs 

significantly from zero. Thus, the collection rate data from these five 

power plants suggest that there has been no systematic change in the size of 

the white perch population during the period 1973 - 1977 (1972 - 1977 for 

Danskamner). 

Becausle of the age of sexual maturity for females and the multiple

age-class composition of the spawning population of females, and because 

impingement mortality increased appreciably starting in 1973 and 1974, a 

systematic decrease in year-class strength due to impingement mortality

would only start to manifest itself with the 1977 (or 1978) and subsequent 

year classes. Female white perch collected in the Indian Point region in 

May 1973 inldicated 24% sexual maturity at age 2, 96% at age 3, 92% at age 4,

and 10% at age 5 and older (Texas Instruments, 1975a, p. HI-22). The 

!arge increases in power plant intake flow occurred during 1973-1975 

(Christensen et al. 1976, Fig. 6). Thus, the year classes spawned &ring

these years were spawned by year classes that were not themselves subjected

to the increased levels of impingement mortality. Assuming a median age of 

reproduction of 4 years, only starting in 1977 or 1978 would the compounding 
--- 

-- 

-- 

11-4 

Table 1. Summary of results from regression analyses to examine the time series 

of collection rates for trends in the Hudson River young-of-the-year 

white perch populationa 

Month N r2 b P N r' b, p N r .b P 2 

__----- . _:, _I_--

Bowl ine Lovett Indian Point 2 

January 5 0.06 -84.5 0.68 5 0.60 208. 0.12 5 0.53 5810. 0.16 

February 5 0.17 -95.1 0.49 5 0.27 95.7 0.37 5 0.44 11539. 0.22 

March 5 0.21 -80.6 0.44 4 0.88 -29.8 0.06" 5 0.12 -565. 0.57 

Apri 1 5 0.11 -75.7 0.58 5 0.11 -39.5 0.59 5 0.02 349. 0.82 

May 5 0.53 -24.0 0.16 5 0.37 -23.1 0.27 4 0.21 -462. 0.54 

June 5 0.00 0.00 - 5 0.00 0.00 - 5 0.00 0.00 - July 5 0.05 -1 -00 0.71 5 0.00 -0.02 0.99 4 0.63 8.49 0.21 

August 5 0.26 13.2 0.38 5 0.25 -8.09 0.39 4 0.14 93.2 0.63 

September 5 0.03 0.52 0.79 5 0.02 -0.65 0.82 5 0.04 28.5 0.75 

October 5 0.26 7.42 0.39 5 0.35 33.3 0.29 5 0.81 534. 0.04* 

November ~ 5 0.16 65.2 0.51 5 0.71 93.6. 0.07* 5 0.59 1795. 0.13 

December 5 0.06 81.1 0.70 5 0.15 45.8 0.52 4 0.63 5625. 0.20 

Annual 5 0.05 -16.1 0.72 4 0.67 29.9 0.18 4 0.74 2335. 0.14 

Roseton Dans kammer All Five Plants 

January 4 0.83 4.65 0.09* 6 0.25 2.23 0.31 5 0.52 1149. 0.17 

February 4 0.24 4.05 0.51 6 0.27 2.26 0.29* 5 0.42 2261. 0.24 

March 4 0.88 12.7 0.06~ 6 0.54 t3.0 0.10 5 0.21 -21 6. 0.44 

Apri 1 4 0.21 55.7 0.54 6 0.48 121. 0.13 5 0.01 33-5 0.90 

May 4 0.37 77.1 0.39 6 0.08 36.0 0.58 5 0.21 -96.9 0.43 

June 4 0.00 0.00 - 6 0.00 0.00 - 5 0.00 0.00 - July 5 0.01 0.033 0.85 6 0.44 -2.82 0.15 5 0.00 -0.247 0.91 

August 5 0.26 17.8 0.38 6 0.36 -14.8 0.21 5 0.06 13.4 0.68 

September 5 0.42 -59.8 0.23 6 0.19 -8.83 0.39 5 0.06 -7.05 0.70 

October 5 0.34 -80.8 0.30 6 0.10 25.2 0.54 5 0.84 108. 0.03" - November 5 0.04 23.7 0.76 6 0.26 109. 0.30 5 0.79 419. 0.04" 

December 5 0.01 -1.67 0.87 6 0.03 -4.01 0.73 5 0.05 255. 0.. 73 

Annual 4 0.49 14.8 0.30 6 0.40 23.2 0.18 4 0.45 402. 0.33 

aThe regression model used was Y = a + bX, where Y is collection rate for yoy whi 

r$eperch and X is year. M is the number of data points (i.e., number of years). 

is the coefficient of determination (i:e., the fraction of variability in Y values 

accounted for by XI. b is the slope of the straight line. .P is *he probability of obtaining a slope this steep (either positive or negative) if .the true slope is 

0.0. P values I 0.10 are .indicated by an asteriak (*). 
I 

It 11-5 

i 

effect of entrainment and impingement mortality have an opportunity to 

manifest itself in reducing year-class strength. 

I 

The variability in the collection rate data already available can be 

used as a guideline to estimate how much of a reduction in population size 

(and for how many years) would be required in order to detect it 

statistically (i.e. , statistical power of the test). However, assuming that 

a statistically significant decrease did occur, independent evidence 

indicating the same result would be required to demonstrate conclusively

that such cl decrease was related to "overfishing" by the power plants (Christensen et a1, 1976). 

1 

C. Variation in Collection Rate Among Months 

Variat:ions in mean collection rate among months are high!ighted in 

Table 2 for young-of-the-year white perch and in Tab e 3 for yearling and 

older white perch, The pattern among months depends quite noticeability on 

location. In particular, at the downriver plants (Astoria, Bowline, Lovett,

and Indian Point), collection rates of white perch of all ages are highest

during the months of December, January, and February, with the months of 

November, March, and April also being quite high an occasion. In contrast, 

at the upriiver plants (Roseton, Danskmer, and Albany) collection rates of 

white perch of all ages indicate two peaks, one in April and Fay and a 

second in September, October, and November. Collection rates of yearling

and older white perch also tend to be relatively high at a number of the 

power plants in June (Table 3), which in part is an artifsct due to 

designating May 31 - June 1 (a one-day interval) as the dividing line 

between 12-month old young-of-the-year and 13-month old yearlings. 

D. .

Variation in Collection Rate Among Power Plants 

Variation among power plants in the mean annual collection rate is 

surprisingly great (Tables 2 and 3, last column). Although data are 

available for only one year at Astoria, and there is no way to estimate from 

the data reported the collection rates for yoy and older white perch separately, it is evident that relatively few white perch are impinged at 

Astoria. At the other geographical extreme, it is evident that impingement of yoy white perch is relatively low at Albany compared to the other plants (Table Z), but Albany ranks third out of eight power plants with respect to 

the impingement of yearling and older white perch (Table 3). In fact, at 

Albany the impingement of yearling and older white perch is appreciably higher in absolute numbers than for yoy white perch. 

For Bowline, Lovett, Indian Point, Roseton, and Danskamer, impingement of yoy white perch is higher in absolute numbers than impingement of older 

white perch. The values for Indian Point Unit 2 are appreciably higher than 

those for any other plant (see Table 2). Although the values for Indian 

Point Unit 1 are also high, impingement of fish at Unit 1 is not presently 
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11-8 

of major concern, since the unit is not presently generating electricity. 

The circulating pumps are generally only operated for experimental purpose 

(e.g., testing of fine-mesh screens). Impingement of yoy white perch is 

higher at Bowline and Lovett than at Roseton and Danskamner (Table Z), but 

the rankings are reversed for impingement of yearling and older white perc 

(Table 3). 

c 
11-9 

3. WHITE PERCH ABUNDANCE AND MORTALITY 

A. AbundanceNo estimates have been made of the absolute abundance of yearling and 

older white perch in the Hudson, and none of the existing data are adequate

for this purpose. However, two independent estimates of the abundance of 

white perch juveniles are available. The first, or combined gear estimate, 

is derived from a combination of data from the Texas Instruments (TI)

longitudinal1 ichthyoplankton survey, fall shoals survey, and riverwide beach 

seine survey. Descriptions of these surveys can be found in the Multiplant

Report (TI 1975b) and the Final Research Report (FRR) (Exhibit UT-4 and 

revisions arid errata). A detailed description of the method used to 

calculate abundances from these data was provided through 

a response dated February 27, 1978 to an EPA information request dated 

December 27, 1977. According to that response, Texas Instruments has 

calculated on a weekly basis the combined gear population estimates for the 

months of July through December 1974 and on a biweekly basis the estimates 

for the months of July through December 1975. These data also were provided

in the response dated February 27, 1978 to the information request of 

December 27, 1977. 

The second estimate is derived from a mark/recapture program conducted 

by Texas Instruments. Descriptions of the methods used in data collection 

and analysis can be found 'in the Multiplant Report and the FRR. 

Mark/recaptwre estimates of white perch juvenile abundance in October 1974 

and in October 1975 are presented in a supplement to the FRR (Exhibit UT-3 

and revisions and errata). A comparison of the two sets of estimates 

reveals substantial discrepancies for both years (Table 4). The 

mark/recaptwre estimates are far larger than the corresponding combined gear

estimates, 14 times as high in 1974 and 6 times as high in 1975. We believe 

that the mark/recapture estimates are the more reliable of the two sets for 

reasons discussed below. 

The combined gear estimates undoubtedly underestimate the true 

abundance of white perch, since TI made no corrections for gear efficiency

(Exhibit UT-4, Sections 7.9.1.2, 7.9.1.3, and 7.9.1.4). In effect, they

assumed that all of the gears (beach seine, epibenthic sled, and Tucker 

trawl) catch 100% of the fish in their path. In reality, no gear captures

100% of the organisms in its path. Even the smallest larval fishes possess 

a limited ability to evade capture. Recent tests conducted by Texas 

Instruments (1978) indicate that the efficiency of the 100-foot beach seine 

at catching juvenile white perch probably ranges between 7 and 25%. The 

epibenthic sled and Tucker trawl were designed primarily as ichthyogbankton 

gear. Since the majority of juvenile white perch are well in excess of 50 

mm in length by early August, the efficiency of these gears during the 

period of interest here (August-December) is probably very low. Although no 

attempts have been made to quantify the efficiency of the epibenthic sled 

and Tucker trawl, Kjelson and Johnson (1978) have recently reported that the 

6.1-m Otter trawl, which, because of its larger size, is probably more 
11-10 

Table 4. Estimates of white perch juvenile abundance in the 

Hudson Rivera 

Oc tober , 1974 October, 1975 

Combined gear est irnateb 1.5 x 106 5.0 x 106 

Mark/recap ture est irnatec 21 x 106 30 x 106 

aRegions included in the combined gear estimates were 

RM 24-61 (KM 38-98) in 1974 and RM 14-76 (KM 22-122) in 

1975. The region included in the markhecapture estimates 

was RM 12-152 (KM 19-243) during both years. 

bBased on extrapolation from beach seine and epibenthic

sled data. Value for 1974 is mean of five weekly estimates. 

Value for 1975 is mean of 3 biweekly estimates. 

CBased on fish released in the fall and recaptured the 

fo 1lowi ng spring. 
11-11 

efficient thaa either of the above gears at catching juvenile fish, is only

about 30-50% efficient. 

An additional source of error in the combined gear estimates for white 

perch is the design of the sampling program itself. As described in the 

Multiplant Report (Section 3), the longitudinal river survey, fall shoals 

survey9 and the riverwide beach seine survey are all designed for optima?

sampling of striped bass. A common result of this design has been the 

collection of large numbers of samples in regions that contain low densities 

of white perch, and the collection of few samples in regions containing high

densities of white perch. For example, during the period August 19-22, 1974,

34 epibenthic sled tows were conducted in the Tappan Zee region. No white 

perch were caught. Virtually all of the white perch collected during this 

period (58 out of 64) came from five tows collected from the shoal stratum 

of the Cornwall region. 

By comparison, the mark/recapture estimates seem to be more free of 

major biases- Population estimates calculated from mark/recapture data are 

subject to several sorts of biases (Ricker 1975). Three that seem 

potentially important in this application, although probably only as minor 

biases, are: differential mortality of marked and unmarked fish,

nonhomogeneous distribution of marked and unmarked fish, and the natural 

occurrence of "marked" fish. 

If marked fish suffer more mortality than unmarked fish, either from 

the stress imposed by handling and marking or because marked fish are more 

vulnerable to predators or disease than are unmarked fish, then an 

overestimate of ?he true population size can result. TI addressed this 

problem with experiments conducted in 1973 (described in the Multiplant

Report) iInd derived correction factors to account for short-term (54 days)

handiing mortality of marked white perch. The possibility that long-term

survival of marked white perch under natural conditions may be lower than 

that of unmarked fish has not been evaluated by TI. 

The Peterson method of ,estimating pow1 ation size from mark/recapture

data, the method chosen by TI, requires that marked fish mix completely with 

the unmarked population prior to recapture. If this mixing does not occur, 

a bias clan be introduced into the results. In particular, if sampling during

the recapture period is concentrated in regions where marked fish are 

relatively abundant in comparison to their true proportion fn the population,

then the true population size will be underestimated. In the N.lw;tip'lant

Report, TI cited insufficient mixing as a reason for discarding estimates of 

the number of juvenile white perch in the Hudson in the fall of 1973. In 

this case fish were both marked and recaptured in the fall. Insufficient 

mixing is probably not a problem with the fall 1974 and 1975 estiaates,

because fish were released in the fall and recaptured during the following

spring. From the distributional data presented in Exhibit UT-4 

(Section 6.1 ) and from the seasonal patterns of impingement discussed in 

Section 11 of this report, it is evident that white perch juveniles migrate

downstream to Haverstraw Bay and the Tappan Zee in the late fall and 

i 

1 
11-12 

overwinter there before returning upstream in the spring. These migration!

would appear to provide ample opportunity for mixing. 

TI uses finclips to mark juvenile white perch and striped bass. Natur' 

loss of fins is not uncommon, and the mistaking of fish that have lost fin: 

for marked fish can cause underestimates of population size. TI has 

discovered several such "fin anomalies." According to the Multiplant Repor

in 1974 it was discovered that about 0.3% of unmarked juvenile white perch 

were missing one or both pelvic fins. This finding necessitated the 

recalculation (by excluding fish marked with single or double pelvic

fincl ips) of mark/recapture estimates for the 1973 year-class.

Mark/recapture estimates of the August-September, 1975 abundance of white 

perch juveniles (Exhibits UT-3, UT-4) were discarded after it was discover� 

that a mark type (anal finclip) used in the August-September, 1975 release 

also occurs among unmarked fish. To this date no fin anomalies have been 

noted that involve any of the finclip types (six marks were used; five of 

these were double finclips) used in the October-November, 1974 and October, 

1975 releases. We presently believe that the Peterson mark/recapture

estimates of white perch juvenile abundance in October of 7974 and 1975 arc 

the best available estimates of the abundance of the 1974 and 1975 

year-classes. It is these estimates that are used in the direct impact 

assessment contained in Section IV. 

B. Mortality 

Dew (1978) has used the catch-curve method to calculate an average

annual mortality rate for age zero and older white perch (Table 5)*. His 

results are derived from bottom trawl data collected in the vicinity of thc 

Bowline Point Generating Station between 1977 and 1976. We believe, howeve 

that age zero fish shoufd not have been used in this analysis, since their 

mortality is probably higher than that of yearling and older fish. We also 

believe that Dew's method of analysis was not the most appropriate

application of the catch-curve methodology. Dew estimated the annual 

fractional mortality separately for each age-class, grouping together all 

fish of age 5 and older. He then averaged the individual estimates (value

for A of 0.53 in Table 5). Robson and Chapman (1961)have described an 

entirely different method of calculating average annual mortality when all 

fish older than a certain age are grouped together. As Robson and Chapman'

method has been proven to be unbiased (whereas Dew's method has not) under 

the assumptions of the catch-curve method, and since its statistical 

properties are known (which is not the case with Dew's method), we believe 

that it is superior to Dew's method. Therefore, we have redone Dew's 

analysis, excluding the age zero fish and using the method of Robson and 

Chapman (1961), to calculate an annual mortality rate fw- yearling and 

older white perch of approximately 50% (value for A of 0.49 in Table 5).

This value is undoubtedly in error to some extent, since the catch-curve 

method is sensitive to fluctuations in year-class strength (Robson and 

Chapman, 1961). However, it is in good agreement with values obtained by 
a 

T 11-13 

Y. 

Table 5. Catch-curve estimates of white perch mortality based on 

bottom trawl data from the Bowline Point vicinity, 1971-1976 

Original valuesa 

(ages 0 through 5+) 

Recalculated valuesb 

(ages 1 through 5+) 

acalculatled by Oew, 1978. 

bRecalculated by excluding

Robson and Chapman, 1961. 

Annual fractional 

mortal ity 

(A) 

0.5349 

0.4854 

Annual instantaneous 

mortality rate 

(Z) 

0.7655 

0.6644 

age 0 fish and using the method of 
11-14 

Wallace (1971) for age I-IV white perch in the Delaware River: 54% for 

males and 58% for females, We believe at this time that 50% is a reasonat 

estimate, and this is the value used in our direct impact assessment. 

None of the available data appears adequate for deriving reliable 

estimates of total mortality in impingeabJe young-of-the year white perch,

Using the method employed by TI to estimate mortality in juvenile striped

bass, we attempted to calculate a mortality rate using TI'S weekly combinr 

gear estimates of white perch abundance. The method involves regressing t 

natural logarithm of the population estimate against time (in days) from t 

end of July to mid-December. The slope of the regression line is an 

estimate of the daily instantaneous mortality rate. Using this method we 

obtained no useful results, because there was no discernible decline in tt 

combined gear estimates- between early August and mid-December. We perforn 

a similar analysis using data from only a single gear, the epibenthic slec 

and a single sampling program, the fall shoals survey, in the hope of 

eliminating variation due to pooling different gears and different samplir 

programs. Although the epibenthic sled samples during the fall shoals 

survey seemed like the best single source of data from which to derive 

estimates of total mortality, this analysis was even less successful: 

population estimates based on epibenthic sled data alone increased betweer 

August and December, both in 1974 and in 1975. 

We have, therefore, used a range of values for young-of-the-year

mortality in our direct impact assessment. As a high estimate we have USE 

the value of 80% assumed in Exhibit UT-3. Given the absence of a seasonadecline in the combined gear and epibenthic sled abundance estimates, this 

value may be too high. Alternatively, we have assumed that the mortality 

among impingeable young-of-the-year is identical to that among yearling ar 

older fish, i.e., that the annual fractional mortality of young-of-the-ye:

white perch is about 50%. Since, because of their smaller size,

young-of-the-year should be more vulnerable to predators than are older 

white perch, this value may be too low, 
11-15 

4. ESTIMATION OF CONDITIONAL MORTALITY RATE 

AND EXPLOITATION RATE DUE TO IMPINGEMENT 

The empirical model of impingement impact used to estimate the 

conditional mortality rate and exploitation rate due to impingement for the 

Hudson River white perch population is described in Barnthouse et al. 

(1979). The model requires: (1) estimates of the initial number of 

young-of-the-year in the Hudson River white perch population at the time 

they first become vulnerable to impingement, (2) estimates of the rate of 

either total or natural mortality during the period of vulnerabi 1 ity to 

impingement, and (3) monthly estimates of the number of white perch impinged

by year class. 

For the purpose of comparing alternative assumptions about the age of 

impinged fish, it is desirable to formulate the model in terms of natural 

rather than total mortality, even though in practice only total mortality 

can be directly estimated from field data. This is not a major problem,

however, since it is possible to calculate the conditional natural mortality

rate, given the total mortality rate and the impingement exploitation rate 

(Barnthousle et al. 1979). In addition, when natural mortality is high

relative to impingement mortality, total mortality and natural mortality are 

nearly num~ericallyidentical. For example, the natural conditional 

mortality rate calculated by Barnthouse et al. (1979)for impingeable

young-of-the-year striped bass was 0.79, only slightly smaller than the 

total mortality rate of 0.8. Similarly, we believe that it is reasonable to 

use the same value (0.5) as an approximation of both the natural conditional 

mortality rate and total mortality rate in yearling and older white perch. 

The estimates of initial population size and natural mortality rates 

are given 'in Table 6, and the bases for these estimates are discussed in the 

preceding section of this report (Section 3). Monthly estimates of the 

number of white perch impinged by year class are given in Table 7. These 

estimates 'includewhite perch impinged at all the power plants discussed in 

Section 2 and in the Appendix, except Astoria, Although impingement data 

ape not available for the Albany power plant except for the period April

1974 - March 1976, Albany was operating continuously during the period June 

1974 through December 1977, which is the period considered in this report in 

estimating conditional mortality rates and exploitation rates due to 

impingement for the 1974 and 1975 year classes. Consequently, the number of 

young-of-the-year and older white perch collected at Albany was approximated

for each month from April 1976 - December 1977, as described in Table A-1 of 

the Appendnx. 

Tho value of a sexually immature fish to a population increases with 

its age, because its probability of surviving to sexual maturity inclreases. 

For this reason the impact to the population of killing a sexually immature 

fish increases with its age. If, as the utilities assume, the total 

mortality of juvenile white perch between July of year 0 and July of year 1 

is 80%, then a single yearling impinged in July is worth five juvenils 
11-16 

Table 6. Initial population sizes and mortality estimates used in the 

empirical model of impingement impact to estimate the conditional mortality rate and exploitation rate due to impingement for the Hudson River white perch population 

Year class 

Natural 

Initial population sizea mort a1 ityb 1974 1975 

POctober IC LB 12 21 

BE 

(x 106) UB 

21 30 

39 45 

PJuIy l6d LB 

(x 106) 

BE 

Low 

High 

Low 

13.9 24.3 

16.8 29.4 

24.3 34.7 

High 29.4 41.9 

UB Low 45.1 52.0 

High 54.5 62.9 

aBE denotes'the best estimate of initial population size. LB and UB 

denote the lower and upper bounds, respectively, of the 95% confidence 

interval about the best estimate. 

bLow natural mortality: rn = 0.001899 per day for the entire period

of vulnerability to impinqement. ." This instantaneous natural mortality

rate correspond; to an annual li.e., 365 days) conditional mortality " 

rate due to all causes of mortality other than impingement of 0.5. 

High natural mortality: rn = 0.004409 per day from July 16 as youngof-the-year to May 31 of the following year just as they become 

yearlings. This instantaneous natural mortality rate corresponds to 

an annual (i.e., 365 days) conditional mortality rate due to all causes 

other than impingemeet of 0.8. rn = 0.001899 per day from June 1 as 

yearlings until the end of the period of vulnerability. 

CPOctober 1 denotes the size of the Hudson River young-of-the-year

white perch population on October 1, as estimated by Texas Instruments 

using mark-recapture techniques (Exhibit UT-3, p. 2-VII-2, as modified 

by errata). 

dPjuly 16 denotes the size of the Hudson River young-of-tk-year

white perch population on July 16. It is calculated using the equation 

where values for POctober 1 and rn are given elsewhere in this 

table and 76 is the number of days between July 16 and October 1. 
.. 

139; 751 130; 26 i 

609,090 11 1,820 

91,910 90,151 

11-17 

Table 7. Monthly estimates of the number of white perch impinged at 

all the Hudson River power plants combined for the 1974 and 

1975 year classesa 

Year class 

1974 1975 

Number of years Number of years

of vulnerability of vulnerabi lfty . .. 

(years) - Month 2 3 2 3 

0 '6 0 0 

7 3,486 8,898 

8 14,887 97,910 

9 '. 26.239 83,980 

10 112;957 93.888 

11 245.492 239,150 

12 607;434 348,596 

1 415,724 589,206 

2 

3 

4 

270.751 

139; 751 

609,090 

182.891 

130; 26i 

111,820 

5 91,910 90,151 

1 6 37,242 18,621 27,014 13,507 

7 22,126 11,063 13,835 6,918 

8 14,122 7,061 6.770 3.385 

9 19,924 9,962 13,791 6,896 

10 19.534 9,767 25,676 12,838 

11 28,005 14,002 12,552 6,276 

12 7,803 3,902 48.102 24,051 

1 38,078 19.039 143,010 71.505 

2 

3 

9,293 

12,444 

4,646 

6,222 

43,558 

49,579 

21,779 

24,790 

4 14,103 7,052 38.692 19.346 

5 7,612 3,806 56,365 28.182 

2 6 13,507 35,710 

7 6,918 8, BO5 

8 3,385 12,662 

9 6,896 8.736 

10 12.838 17,362 

11 6,276 19,145 

12 

1 

24.051 

71,505 

10,890 

2 21.779 

3 24,790 

4 19,346 

5 28,182 

Age 

Q 

t 

1. aMonthly vafues for number of yoy white perch impinged Were calculated 

by sumning the NUMBER0 values in Tables A-1, and A-3 through A-9 in 

Appendix A over pwer plants for the appropriate month and year.

3 nonthly values for number of yearling white perch impinged were calculated either by sumning the NUMBER1 values over pwer plants for the 

appropriate month and year (2 years of vulnerability, corresponding to 

the assumption that 100% of the yearling and older white perch impinged

I were yearlings) or by suming the NUMBER1 values over power plants and - dividing by 2 (3 years of vulnerability, corresponding to the assumption that 50%of the yearling and older white perch impinged are yearlings). 

t Monthly values for number of 2-year-old white perch impinged were calculated by sumning the NUMBER1 values over power plants, dividing by 2. 

and tabulating the result for the given month, but one year later 

(3-years of vulnerability only, corresponding to the assumption that 

5oX of the yearling and older white perch impinged are 2-year olds). 3 

t 
11-18 

impinged 12 months earlier. If mortality between year 1 and year 2 is 50%,

then each 2-year-old white perch is worth two yearlings or ten young-of-theyear. Even though the number of yearlin9 and older white perch impinged

each year constitutes only about 10% of the total white perch impingement,

the impact of killing these fish is quite substantial, 

As indicated in Table 7, two alternative assumptions were made 

concerning the age of impinged yearling and older white perch, For one case 

it was assumed that all wnite perch impinged that are yearlings and older 

are yearlings, resulting in two years of vulnerability to impingement. For 

the other case, it was assumed that of the yearling and older white perch

impinged, 50% were yearlings and 50% were 2-year olds, resulting in three 

years of vulnerability to impingement. It is our judgment, based on lengthfrequency data of impinged white perch at Bowline, Indian Point, and Rosetor 

(see Appendix, Tables A-3, A-5, 6 & 7, and A-9), that the true age

composition of yearling and older white perch impinged (which includes some 

white perch older than 2 years), results in an effective split between 

yearlings and 2-year olds that is between the two assumptions just given,

that is, between 100% yearlings - 0% 2-year olds and 50% yearlings - 50% 

2-year olds. Because of the lack of 1978 impingement data for January - May, no model estimates of impingement impact assuming three years of 

vulnerability are given for the 1975 year class. 

Edith this exception, estimates of conditional mortality rate and 

exploitation rate due to impingement are given in Table 8 for the 1974 and 

1975 year classes for combinations of estimates and assumptions involving

initial population size (low, best estimate, and high), natural mortality

(low and high), and number of years of vulnerability (2 and 3 years). 

Estimates of the conditional mortality rate due to impingement are 

especiaily relevant in assessing the effects of power plant impingement,

sixe they are equivalent to estimates of the fractional (or perceilt) reductim in the size of a year class due to impingement, assuining no compensation (see Barnthouse et a1 1973). As indicated by the values in Table 8, 

percent reduction values (obtained by multiplying by 100) are greater (1)

the smaller the initial population size, (2) with high natural mortality 

rates as opposed to low, and (3) assuming three years of vuinerabi?ity instead of two. Furthermore, assuming approximately comparable degrees of 

uncertainty in the choices of low and high estimates of initial population

size, natural mortality, and number of years of vulnerability, it appears

that the estimates of percent reduction are most sensitive to (ioeopvary 

most wideiy depending on) estimates of initial population size, ieast 

sensitive to the number of years of vulnerability assumed, and intermediate1 

sensitive to estimates of natural mortality. 

The percent reduction values range from 9.5 - 45% for the 1974 year

class and from 7.7 - 24% for the 1975 year class, assumiKg only two years of 

vulnerability. Assuming three years of vulnerability, the percent reductior 

values range from 1249% for the 1974 year class. For the 1975 year class, 

percent reduction values cannot be calculated because 1978 impingement data 

ax not presently available. 
9 

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11-20 

Exploitation rates show the same pattern of variation as the 

conditional mrtality rates with respect to values used for initial 

population size, natural mortality, and number of years of vulnerability

{Table 8). The exploitation rates range from 5.1 - 20.0% for the 1974 year

class and from 3.8 - 9.9% for the 1975 year class, assuming only two years 

of vulnerability. Assuming three years of vulnerability, the exploitation 

rates range from 5.3 - 20.9% for the 1974 year class, and, although they 

cannot be calculated at this time, they would be expected to be lower for 

the 1975 year class. As discussad in Barnthouse et al. (1979), because 

there are competing sources of mortality and each an organism can die only 

once, an exploitation rate is always lower than the corresponding conditio: 

mortality rate. However, as stated above, it is the conditional mortality 

rate due to impingement that is equivalent to percent reduction in the sin 

of the year class. Because of this equivalence, the conditional mortality 

rate is a more meaningful measure of impact than is the exploitation rate. 
11-21 

5. DISCUSSION 

A. Comparison With Utilities' Results 

The utilities have estimated the Conditional mortality rate and 

exploitation rate due to impingement of white perch for the 1974 year class 

(Table 9). 

Impingement impact for the 1974 year class was estimated assuming

that 90% of the July 1974-June 1975 impingement consisted of the 

1974 year class. Exploitation of this year class was calculated 

to be 4.4% at Indian Point Unit 2 and 5.9% for the multiplant case 

(Table 2-VII-1). These exploitation rates are equivalent to 

conditional mortality rates of 8.5% for Indian Point and 11.2% for 

multiplant with an assumed total mortality rate of 80%. 

(Exhibit UT-3, p. 2-VII-3) 

In terms of the Comparability of assumptions and input values used in 

the utilities' methodology and our methodology, the utilities' conditional 

mortality rate of 11.3% and exploitation rate of 5.9% in Table 9 for the 

multiplant case-canbe compared with our estimates in Table 8 (two years of 

vulnerability, best estimate of initial population size, and high natural 

mortality) of a conditional mortality rate of 25.5% and an exploitation rate 

of 11.4%. The two sets of estimates differ by approximately a factor of 2 

for several reasons (we have not attempted to estimate how much of the 

two-fold difference is due to each of the following reasons): 

(1) We included the Albany, Danskammer, and Lovett Steam Electric 

Generating Stations, while they did not. These three plants were 

operating during the years 1974 - 1977 and were impinging white 

perch. Thus, they should be included in any evaluation of the 

impact of impingement on the Hudson River white perch population. 

(2) We included Indian Point Unit 1, which operated continuously (at

least the circulating water pumps) from June 1974 through August

1975, while they did not. Since this unit was operating during 

part of the period of interest and was impinging white perch, it 

also should be included in any evaluation of the impact of 

impingement on the Hudson River.whiteperch population. 

(3) Our values reflect two years of vulnerability to impingement,

while their values reflect only one year of vulnerability (i.e.,

they ignored impingement of yearling and older white perch from 

the 1974 year class past June 1975). Since yearling and alder 

white perch, in fact, are impinged in appreciable numbers, they

must be considered as such in any credible evaluation of the 

impact of impingement on the Hudson River white perch population.

There is no scientifically, justifiable methodological reason or 

biological reason for not including these yearling and older white 

perch in such an evaluation. 
11-22 

Table 9. Relevant parts of Table 2-VII-1 in Exhibit UT-3 

Power p 1 ant 

Number 

imp ingeda 

Exploitation 

rate (u) 

Conditional 

mortality (m) 

~ ~-

Bowline 473,043 0.0137 0.0273 

Roseton !2,025 0.0015 0.0030 

Indian Point 

Unit 2 1,520,317h 0.0441 0.0849 

Mu1 tipl ant 2,045,385 0.0594 0.1126 

aTotal impingement, of which 90% are assumed to be 1974 year

class. 

bIncludes 948 impinged at Indian Point Unit 3. 
11-23 

(4) We used available data to estimate on a monthly and plant-specific 

basis the percent of white perch impinged from June 1974 - June 

1975 that were from the 1974 year class, whereas they assumed 90%. 

As the PERCENT0 values in Tables A-1, and A-3 through A-9 indicate, 

their assumption of 90%young-of-the-year may be justified for 

Lovett and for the three Indian Point units. However, the 

utilities' assumption of 90% young-of-the-year is clearly too high 

for Albany, Bowline, Oanskammer, and Roseton. 

(5) We used the methodology presented in Barnthouse et al. (1979),

which permitted us to take into account monthly variations in 

collection rates, whereas the utilities' methodology implicitly 

assumes a constant vulnerability. In reality, as discussed in 

Section 11, the collection rate fluctuates appreciably on a monthly 

basis, with rates being substantially higher from December - May 

than from June - November (Tables 2 and 3). (Also see Table 3 and 

associated text in Barnthouse et al. (1979) for'a comparison using 

constant versus variable collection rates to estimate the 

conditional mortality rate due to impingement.) 

The utilities' choices at every -one of the above five "decision points"

affect the results in the same direction, namely, to lower the estimates of 

impingement impact. Yet, given that the purpose of the utilities' analysis 

and of our own analysis ought to be to realistically and objectively estimate 

the percent reduction in the strength of the 1974 year class of white perch 

in the Hudson River due to impingement at power plants, our choices at each 

of the five decision points is scientifically more sound and defens ble for 

the reasoris we have given. 

B. Is there a problem? 

This testimony presents two independent lines of evidence evaluating 

the impingement losses of white perch at the power plants on the Hudson 

River. The first line of evidence, the analysis of the variation in 

collection rate among years (Section 2.B), suggests that there is not yet an 

obvious problem, but that it is too soon to be sure. The second line of 

evidence, the estimates of conditional mortality rate due to impingement 

(Section 4), suggests th'at the level of impingement impact cannot be 

assessed as acceptable from the point of view of the white perch population. 

These two lines of evidence are briefly elaborated on in the following two 

paragraphs. 

The collection rates provide estimates of year-class strength on a 

relative scale. As such, they reflect the effect of entrainment azd 

impingement losses during the preceding months, as well as the effect of any 

compensatory mechanisms which might alter survival during the preceding 

months. Regression analyses on collection rates of impinged young-of-theyear white perch suggest that there has been no systematic change in the 

size of the white perch population during the period 1972 - 1977 

(Section 2.B). In particular, there is little evidence of a statistically 
11-24 

significant downward trend. However, given the large variability in 

collection rates used in these regressions, the time series are relatively

short (i.e., 5-5 years), and thus, the statistica? power of the test for a 

trend is not high. In addition, because of the age of sexual maturity for 

females and the multiple age-class composition of the spawning population 0. 

females, and because impingement mortality increased appreciably starting i 

1973 and 1974, a systematic decrease fn year-class strength due to 

impingement mortality would only start to manifest itself with the 1977 

(or 1978) and subsequent year classes. 

The estimates of percent reduction in year-class strength due to 

impingement that are presented in Table 8 cover a broad range, as discussed 

in Section 4. Our analysis shows that the level of impingement impact was 

probably greater than 20% for the 1974 year class and was probably greater

than 15% for the 1975 year class. These estimates do not include 

consideration of entrainment, so that the total power plant conditional 

mortality rate is obviously greater than the values given here for 

impingement only. Given the information presently available, it is our 

judgment that this level of impingement impact is not acceptable from the 

point of view of the white perch population. 
1 

1 

1 

1 

E 

II 

b 

Y5 

11-25 

VI. REFERENCES 

Barnthouse, L. W., D. L. DeAngelis, and S. W. Christensen. 1979. An 

empirical model of impingement impact. ORNL/NUREG/TM-290. Oak Ridge

National Laboratory, Oak Ridge, Tennessee. 

Christensen, S. W., W. Van Winkle, and J. S. Mattice. 1976. Defining

and determining the significance of impacts: concepts and methods. 

pp. 191-219. IN R. K: Sharma, J. D. Buffington, and 3. 5. McFadden 

(eds.:), Proceedings of the workshop on the biological significance of 

environmental impacts. NR-COMF-002. 

Dew, C. 6. 1978. Age, growth, and mortality of Hudson River white perch

perch (Morone americana) and the use of these parameters in evaluating

the exploitation rate represented by impingement at power plant

intakes. Paper presented at the Northeast Fish and Wildlife 

Conference, Greenbriar, West Virginia. February 28, 1978. 

Exhibit �PA-205. Barnthouse, L. k’. 1979. An analysis of factors that 

influence impingement estimates at Hudson River power plants.

Testimony prepared for the U.S. Environmental Protection Agency,

Region 11. 

Exhibit UT-3. Supplement I to influence of Indian Point Unit 2 and other 

steam electric generating plants on the Hudson River estuary, with 

emphasis on striped bass and other fish poulations. Edited by J. T. 

McFadclen and J. P. Lawler. Submitted to Consolidated Edison Company of 

New York, Inc. July 1977. Errata correcting the estimates of the size 

of the Hudson River young-of-the-yearwhite perch population on October 

1, originally given on p. 2-VII-2of this reference, are contained in 

Utilities‘ Exhibits UT-3E-2 and UT-3E-5. 

Exhibit UT-4. Influence of Indian Point Unit 2 and other other steam 

electric generating plants on the Hudson River estuary, with emphasis ,’ on striped bass and other fish populations. Edited by J. T. McFadden. 

Prepared for Consolidated Edison Company of New York, Inc. 1977-

Kjelson, M,, A,, and G. N.,Johnson. 1978. Catch efficiencies of a 6.1-meter 

ottor trawl for estuarine fish populations. Trans. Am. Fish. SOC. 

107 :246-254. 

Ricker, W. E. 1975. Computation and interpretation of biological statistics 

of fish populations. Fish. Res. Board. Can., Bull. 191. 382 p. 

Robson, D. S., and D. G. Chapman. 1961. Catch curves and mortality rates. 

Trans. Am. Fish. SOC. 90:181-189. 
11-26 

Texas Instruments, Inc* 1975a. Hudson River ecological study in the area 

Indian Point. 1974 Annual Report. Prepared for Consolidated Edison 

Company of New York, Inc. 

Texas Instruments, Inc. 1975b. First annual report for the multiplant impact study of the Hudson River, Yol. I, July, 1975. Prepared for 

Consolidated Edison Company of New York, Inc. 

. 1978. Catch efficiency of 100-ft (30-m) beach seines 

for estimating density of young-of-the-year striped bass and white 

perch in the shore zone of the Hudson River estuary, Prepared for 

Consolidated Edison Company of New York, Inc. 

USNRC (U. S. Nuclear Regulatory Commission). 1975. Final environmental 

statement related to operation of Indian Point Nuclear Generating Plar 

Unit No. 3, Consolidated Edison Company of New York, Inc. NUREG-75/0( 

Wallace, 0. C. 1971. Age, growth, year class strength, and survival rates 

of the white perch, Morone americana (Gmelin) in the Delaware River ir 

the vicinity of Artificial Island. Chesapeake Science 12:205-218. 
11-27 

APPENDIX 

IMPINGEMENT DATA BASE 

The data base is presented by power plant, 

arranged in alphabetical order 
I 1-29 

TABLE A-1 

WHITE PERCH IMPINGEMENT DATA FOR THE 

ALBANY STEAM ELECTRIC GENERATING STATION 

April 1974 - March 1975: Ref. (1) 

RATE (collection rate) :1 calculated from monthly data on 

average observed number of fish of all species collected per

million gallons of intake flow at all units (from Table 3,

Column 6, Plant Av.), and monthly data on percentage

composition by species of the fish collected (from Table 4), 

NUMBER (number collected): calculated fron monthly data on 

estimated number of fish of all species collected at all 

units (from Table 2, Column D, Total) and monthly data on 

percentage composition by species of the fisk collected (from

Table 4). 

PERC ENTO (percent of the white perch collected that were young-ofthe-year): calculated with the aid of graph paper and a 

dissecting microscope from the monthly plots in Fig. 10 of 

frequency versus length intervals of white perch collected at 

the Albany Steam Electric Generating Station for each month 

April through November 1974. The "DIVISION" criteria 

specified by Texas Instruments were used as the cut-off 

1ength between young-of -the-year and yearling white perch (see Table A-10 in this appendix). 

April 1975 - i4arch 1976: Ref. (2) 

RATE (collection rate) :1 calculated from monthly data on 

average observed number of fish of all species collected per

million gallons of intake flow at all units (from

Table IVC-16) and monthly data on percentage composition by species of the fish collected (from Table IVC-14). 

NUMBER (number collected): calculated from the monthly collection 

rates (RATE) described immediately above and monthly values 

of average daily plant flow for all units in millions of 

gallons per day times the number of days in the particular

month. 

Preceding page Mank .-. 
11-30 

TABLE A- 1 (continued) 

PERCENTO (percent of the white perch collected that were young-ofthe-year): calculated with the aid of graph paper and a 

dissecting microscope from the plots in Fig. IVC-6 of 

relative frequency versus length intervals of white perch

collected at the Albany Steam Electric Generating Station fc 

each month May through November 1975. The “DIVISION44 

criteria specified by Texas Instruments were used as the 

cut-off point between young-of-the-year and yearling white 

perch (see Table A-10 in this appendix). 

RATE, NUMBER, and PERCENTO values were approximated as follows for eac 

month during 1974 through 1977 for which estimates were not directly

available from Refs. (1) and (2). These approximations were necessary in 

order to have a complete data set with which to estimate exploitation rates 

and the conditional rates of mortality due to impingement (see Section 4). 

RATE and NUMBER: approximations for each month were calculated as the 

average of the two monthly estimates available from the period April 1974 

through March 1976. These approximations were used for January-March 1974 

and April 1976 - December 1977. 

PERCENTO: for May through November approximations were calculated as 

just described for RATE and NUMBER. The approximation for November was als 

used for the months of December and January of all years. The April 1974 

value (no estimate for April 1975 was available) was used as the 

approximation for April 1975, 1976, and 1977 and for the months of February

and March of all years. 

RATEO = PERCENTO RATE/100 and RATEl = RATE - RATEO. 

NUMBERO = PERCENTO NUMBER/100 and NUMBER1 = NUMBER - NUMBERO. 

RATE, NUMBER, and PERCENTO are defined above. RATEO and RATEl are the 

collection rates for young-of-the-year and for yearling and older white 

perch, respectively. NUMBERO and NUMBER1 are number collected for 

young-of-the-year and for yearling and older white perch, respectively. 

1All collection rates were converted from number of white perch

collected per million gallons to number of white perch allected per

million cubic meters by multiplying by 264.17 gallons per cubic meter. 

Collection rates were assumed to equal impingement mortslity rates. 
E 

E 11-31 

TABLE A-1 (continued) 

IEAR llONTR R1l’E JOYBE3 PER28 RTO RLTEO RArEl 13ne em 801 BEE 1 

?974 t 0.000 3.5 10.70 0.0000 0.133 0.31 3. t 

197G 2 0.528 15.5 19.63 0.1036 0.425 3.08 12.5 

197G 3 6.668 260.5 19.60 1.3162 3.522 51.35 209. U 

1979 4 77.738 3323.3 19.60 15.1190 62.019 768.91 315U.l 

9970 S 95.10 t 5518. 0 35.50 33.7509 51.3U3 1958.93 3559.1 

1970 5 133.930 1717.3 0.30 0.0000 133.934 0.00 7717.3 

9970 ? 211.072 12516.0 0.00 0.3300 211.172 0.33 1251 8.0 

0570 e 105.932 5234.3 5.88 6.2288 99.703 370.09 5923.9 

1970 9 178.051 9868.0 2.00 a.3si3 173.706 2UO. 13 96 27.2 

1374 10 305.391 ?7325.3 1.79 5.4663 299.9 1 P 310.12 1701 P .9 

197U 19 61.023 3516.0 9.u3 5.7355 55.253 331.56 3 ma. it 

1974 72 0.25U 21.3 10.70 @.07E3 0.236 2.25 18.0 

t975 B 0.000 7.0 10.70 0.30~0 0.133 0.75 6.3 

1975 2 0.193 31.3 19.60 0.1553 0.537 6 -00 211.9 

1975 3 0.26U 10.0 19-60 O.Cj18 3.212 1.96 8.0 

1975 c 1.057 05. 3 19.63 0.237 1 0.050 8.82 36.7 

1975 5 285.568 11711.0 6-58 ia.7900 L55.777 770.98 109Q6.0 

1975 6 ?18.034 5393.3 0.30 0.0000 118.084 0.00 5583 * 0 

1975 7 212.921 6336.0 0.00 0.0300 212.321 0.33 8336.4 

1975 8 29.951 1157.3 6.12 1.8769 28.02U 89.78 1377.2 

1975 9 299.833 lb71U.O 12.UO 37.! 103 ?.52.55@ 1820. 5Q 32889.5 

1975 10 133.036 5335.3 7.52 19.0;21 ‘23.37‘1 153.91 55E2.1 

1975 l? 69.213 29C6.0 11-90 8.2363 50.375 395.01 2560.2 

1975 12 0.250 15.3 10.70 0.Oib3 0.236 1.71 lU.3 

1976 I 0.000 O.@ 10.7G 0.3300 3.333 0.33 0.0 

1975 3 13,208 511.0 19-60 2,5889 13.523 133.15 a io. B 

f956 4 39.397 133U.J 19.60 7-6630 31.43a 388-86 1595.1 

1976 5 190.202 6617.5 21.00 39.9%25 130.253 1609.63 6857. 8 

1976 6 126.009 3126. 5 0.30 0.0000 126.009 0.00 6026.5 

1976 1 211. 660 10~27.0 0.00 0.9030 211.36U 1.33 10027.0 

5976 6 67.392 3393.5 6.00 U.0735 63.816 232.63 3647.7 

1976 9 236.810 12291.0 7.U2 17.73 97 221.333 911.93 11379.0 

1976 10 219.261 11593.5 4.66 10.2 1 76 23 9.0 4 0 544: 31 11136-2 

1576 2 0.330 3: 3 19.60 0.0300 0.000 0.00 0.3 

1976 -

1976 12 0.266 16.5 10.70 0.0283 0.236 1.98 16.5 

1977 1 0.000 3.5 10.70 0.0UBU 0,333 0.37 3.1 

1971 2 0.528 15.5 19.60 0.1036 0.425 3 .OW 92.5 

I957 3 6.868 260.5 19.60 1.30G2 5.522 51.35 209. U 

1975 

1917 

1973 

4 

5

-

6 

39,097 

190.202 

126.009 

1330.3 

66 17.5 

9326.5 

19.60 

21.00 

0.30 

7.66 3C 

39.3%23 

0.0000 

3 1.U34 

150.259 

:26.009 

386.86 

1809.68 

0.00 

‘3595.1 

6807.0 

8026.5 

1971 21 1. 66s lOU27.0 0.00 0.OOOP 21 1.35a 3.33 10Q27.0 

1977 8 67.992 3333.5 6.00 4.0735 63.01Q 232-83 36U7.7 

1977 9 238. a10 12291.3 7.42 17.7197 221.393 911.99 11379.0 

1977 10 219.261 115S3.5 6. 66 10.2176 209.349 SOU .31 11136.2 

1957 19 6U. 986 3291.0 50. 70 6.9535 53.332 303. sa 2867. U 

T977 12 0.264 19; 5 10.70 0.0263 0.236 1.96 16.5 

12 60.986 3211.0 10.10 6.9535 jS.132; 343.58 2867.9 

t 

1. 
11-32 

REFERENCES FOR TABLE A-1 

1. Lawler, Matusky 81 Skelly Engineers. Albany Steam Electric Generating

Station Impingement Survey (April 1974 - March 1975). LMS Project No. 

191-027, prepared for Niagara Mohawk Power Corporation, June 1975. 

2. Lawler, Matusky & Skelly Engineers. Albany Steam Electric Generating

Station, 316(a) Demonstration Submission, NPDES Permit NY 0005959. 

Prepared for Niagara Mohawk Power Corporation, 1976. 
11-33 

TABLE A-2 

WHITE PERCH IMPINGEMENT DATA 

FOR THE ASTORIA GENERATING STATION (Ref. 1) 

RATE (collection rate):l calculated from monthly data on 

observed number of fish and crustaceans of all species

collected per million gallons of intake flow at Units 1-5 

(from Table 12) and monthly data on the percent of the total 

number of fish and crustaceans collected that were white 

perch (calculated from data in Table 4). 

NUMBER (number collected): calculated from the collection rate 

(RATE) described immediately above and the value for full 

flow through Units 1-6 in gallons per minute (from Table 1 j

times the number of minutes in the particular month. 

Data with whsch to calculate RATE and NUMBER values were available only

for the period January 1972 - December 1972. No data were available from 

which to estimate PERCENTO, the,percent of the white perch collected at 

Astoria that were young-of-the-year. The white perch impingement data for 

Astoria have been used only in Section 2.B on seasonal variations in 

collection rates among the different power plants. 

lAll collection rates were converted from number of white perch

collected per million gallons to number of white perch collected per

million cubic meters by multiplying by 264.17 gallons per cubic meter. 

Collection rates were assumed to equal impingement mortality rates. 
11-34 

TABLE A-2 (continued) 

1912 s 1.03 611 25 1 

$972 2 0.62297 1ou 1 

1972 3 t.60067 339 

2972 I 3.13570 7s7 

1912 5 2.09223 522 

1972 6 0. BUS34 20u 

1972 7 0.97490 213 

is72 3 0.00000 0 

1992 9 0.03060 3 

1972 10 0.00000 0 

1972 It 0.00003 9 

1972 12 6.90 767 1733 
11-35 

REFERENCE FOR TABLE A-2 

I 1. Quirk, Lawler and Matusky Engineers. A Study of Impinged Organisms at 

the Astoria Generating Station. QL&M Project No. 125-16, prepared for 

Consolidated Edison Company of New York, Inc., September 1973. 
11-36 

TABLE A-3 

WHITE PERCH IMPINGEMEHT DATA FOR THE 

BOWLINE POINT GENERATING STATION 

January 1973 - December 1976: Ref. (1)-

Values for RATE (collection rate)l and NUMBER (number collected) were 

taken directly from data sheets in Ref. (1). -%. 

January 1977 - December 1977: Ref. (2) 

Values for RATE (collection rate)l and NUMBER (number collected) were 

taken directly from data sheets in Ref. (2). 

PERCENTO (percent of the white perch collected that were young-of-the

year) : 

January 1975 - December 1976: Calculated from monthly data on 

length-frequency in 1-centimeter length intervals of white perch in 

impingement collections [frurn Tables 10.2-13 and 10.2-14 in Ref. (3)).

Tne "DIVISION" criteria specified by Texas Instruments were used as the 

cut-off length between youn -of-the-year and yearling white perch (see

Table A-10 in this appendix4 . 

January 1973 - December 1974 and January 1977 - December 1977: in the 

absence of monthly values during these two periods, estimates were 

calculated as the average of the 1975 and 1976 PERCENTO values for eact 

month. 

RATE0 = PERCENTO 0 RATE/100 and RATE1 = RATE - RATEO. 

NUMBERO = PERCENTO NUMBER/100 and NUMBER1 = NUMSER - NUMSERO. 

RATE, NUMBER, and PERCENTO are defined above. RATEO and RATE1 are the 

collection rates for young-of-the-year and for yeaTling and older white 

perch, respectively. NUMBERO and NUMBER1 are number collected for 

young-of-the-year and for yezling and older white perch, respectively. 

lAI1 collection rates were converted from number of white perch collected 

per million gallons to number of white perch collected Fer million cubic 

meters by multiplying by 264.17 gallons per cubic meter. Collection rates 

were assumed to equal impingement mortality rates. 
PUB 

1973 

1973 

1973 

1973 

197 3 

1973 

197 3 

1973 

197 3 

1973 

197, 

1973 

RONrA 

1 

2 

3 

4 

5 

6 

7 

a 

eArE 

296.13 

353.99 

288.7U 

462.56 

235.90 

19.55 

13.7U 

6s.a~ 

0.76 

s.92 

9.51 

373.31 

1092.87 

1213t34 

968.98 

922.08 

91.a0 

19-99 

5.20 

3-33 

0, u9 

29.32 

b97.17 

845.00 

1899.59 

92.21 

303.00 

1350. 10 

173.82 

15.06 ' 19.28 

0.23 

1-85 

2.3A 

20.34 

622.38 

61 -55 

97.94 

261.00 

607.9C 

22.98 

9.25 

2.91 

113.96 

15.32 

1.06 

610.50 

171%.33 

295.2 9 

306.57 

lU7.9 1 

81.73 

91.35 

24.57 

5.26 

66.36 

1.90 

59.17 

298.47 

359.03 

Pe3:ESTO 

82.6 

78.8 

LUJBEB 

17021 

15194 

U016 

23333 

lU739 

939 

692 

272'4 

285 

326 

500 

13363 

58025 

91003 

91689 

55937 

2901 

1423 

533 

312 

529 

3697 

a3360 

33395 

176382 

7359 

2U651 

113539 

9088 

1229 

1809 

9B5 

190 

133 

1351 

5U906 

2336 

333s 

33906 

57731 

1996 

912 

308 

RATE3 

2'40.5 1 

278.9P 

2411. 95 

392.25 

162-77 

BATE1 

51.527 

75.045 

13.839 

wa ~BEB~ 

lUO59 

12753 

3795 

20270 

10173 

0 

313 

21 30 

233 

302 

u 83 

17753 

48259 

37042 

63832 

90257 

2332 

0 

239 

291 

(I 32 

3423 

D 1625 

80563 

122u03 

5001 

17693 

e1953 

won BEE1 

2961.7 

3S31.0 

680. a 

3633.3 

0569. i 

809.0 

382.0 

593.8 

52.0 

26.1 

20.0 

307.0 

10166.0 

9965.7 

7856.7 

860 9.9 

899.3 

1423.0 

290-2 

81.1 

91.3 

273.6 

173U.Q 

1531.6 

53972.9 

2353.3 

6951.6 

31555.5 

5873- 1 

1228-0 

189.9 

108.5 

07.5 

19.7 

36.79 

8U.8 

94-8 

69.0 

0.0 

UQ.8 

78.2 

81.6 

92.6 

96.0 

90.3 

82.6 

78.8 

8U.6 

04.8 

69.0 

0.0 

40.0 

78.2 

81.6 

92.6 

96.0 

. 38.3 

69.0 

68.0 

71.0 

72.2 

38.1 

0.0 

89.5 

66.7 

75.0 

95.2 

96.5 

99.1 

35.7 

89.7 

97.7 

91;5 

100.0 

0.3 

70.309 

73.133 

19.549 

7.593 

9.905 

3.915 

0.371 

3,333 

6.3US 

l?>. 153 

258.627 

137.230 

180. 217 

13.333 

le. 992 

2,315 

0.799 

3.925 

2.17@ 

13.932 

tu. 366 

563.959 

31.109 

35.117 

375.495 

107.597 

15.058 

2.325 

1.937 

0. h52 

. 0.352 

0.1119 

5.5915 

2.6467 

S. 7682 

5.0335 

i7.1975 

0.3333 

9.21159 

2.3059 

1t 7273 

1.9333 

0.0000 

23.3329 

42.7757 

51.3833 

64.9927 

22.0921 

12.0236 

29. 3135 

2U. 5678 

2-3313 

10. U664 

0.3533 

4.3709 

11.7733 

6.1103 

0. ao 

6-15 

35.53 

3.98 

9.65 

9.13 

36s; 67 

902; 71 

961.31 

621.59 

782.26 

63. Of 

0.00 

2.37 

2.69 

3,b6 

27.15 

U77.28 

830-7 1 

t 317.62 

66. I1 

217.56 

975.21 

66- 23 

0.00 

17.26 

2.82 

1-39 

2-03 

19.63 

616.78 

59-90 

85.07 

255.00 

9 

10 

11 

12 

1 

a 

3 

4 

5 

6 

7 

8 

P 

10 

11 

12 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

1 

2 

3 

s 

5 

6 

7 

8 

9 

10 

11 

12 

1 

2 

3 

0 

5 

6 

7 

8 

9 

10 

11 

12 

i37a 

1979 

'1971 

197b 

1979 

I974 

197e 

197U 

1970 

1574, 

1970 

7974 

1975 

1975 

1975 

1975 

1975 

1975 

1375 

1975 

1975 

1915 

1975 

1975 

1976 

1976 

1976 

1976 

1975 

3976 

1976 

1976 

1976 

1976 

1976 

1376 

7377 

7 977 

1977 

1577 

1377 

1977 

1977 

7977 

197 7 

1977 

1977 

1977 

3615 

0 

16 19 

2 97 

IS3 

113 

1014 

5UU 12 

2810 

3413 

13586 

55703 

1996 

0 

3 

9758 

133U 

49 

31115, 

145637 

20717 

18952 

10767 

5994 

5879 

0 

151 

6117 

131, 

5669 

2 3765 

30528 

ow. 15 

126-25 

391.92 

3 19. ea 

1428.28 

0.00 

812.00 

308.00 

1120.113 

ima2 

0..00 

15 16. Uti 

373U.28 

U 360.09 

5 098. 81 

1929. 90 

1076.34 

26Ql. 20 

1 952 .OO 

186.58 

1705.20 

30.18 

-453.03 

990.20 

.521.95 

670, ro 

22.98 

0.00 

0-00 

102.13 

13:51 

1.06 

582. C 1 

1668.25 

203.91 

2s 1.58 

12s. h 3 

69.3 1 

63.03 

0.00 

2.36 

51.89 

1.55 

54-80 

0.0 

1337~ 99.7 

88.2 

130.0 

95.0 

97.5 

82.6 

78.8 

1512 

83 

32966 

143371 

25081 

28351 

12697 

1063 

8520 

1952 

338 

1922 

161 

5122 

2U756 

31356 

eo.8 

84.8 

69-0 

0.0 

QU.8 

10.2 

81.6 

92.6 

96.0 

38-3 

282-59 

353- 32 
11-38 

REFERENCES FOR TABLE A-3 

I. Letter dated March 3, 1978, from William J. Cahill, Jr. of Consolidatec 

Edison Company of New York, Inc. (Con Ed) to Robert P. Geckler of the 

U. S, Nuclear Regulatory Comnission (US NRC), including a response to 

Question X.l, which is the identification number for a question in 

Enclosure 2 of a letter dated July 26, 1977, from George tl, Knighton

(US NRC) to- - Milliam Cahill, Jr. (Con Ed). 

2. Letter dated May 5, 1978, from Edward G. Kelleher of Consolidated 

Edison Company of New York, Inc, {Con Ed) to Henry Gluckstern of the 

U. S. Environmental Protection Agency (US EPA), including a response tc 

Question A-4, which is the identification number for a question in the 

enclosure of a letter dated March 23, 1978, from Henry Gluckstern 

(US �PA) to Kenneth L. Marcellus (Con Ed). 

3. Ecological Analysts, Inc. Bowline Point Generating Station. Near-fie' 

Effects of Once-through CoDling System Operation on Hudson River 

Biota. Prepared for Orange and Rockland Utilities, Inc., July 1977 

(Exhibit UT-7). 
11-39 

TABLE A-4 

WHIT� PERCH IMPINGEMENT DATA FOR 

TH E DANSKANMER POINT GENERATING STATION 

RATE (collection rate :1 

- January 1372 - December 1976: averaqe of the daily collection 

rates for each month were copied directly from data sheets in 

Ref. (1). 

January 1977 - December 1977: average of the daily collection 

rates for each month were copied dirctly from data sheets in 

Ref. (2). 

NUMBER (number co 11ec ted) : 

January 1972 - December 1977: calculated from the mnthly collection rates (RATE) described imediatcly above and monthly

values of actual total plant intake flow in millions of gallons

for the particular month, from data sheets in Ref. (3) for 1972 ­ 1976 and from data sheets provided by the U. S. Environmental 

Protection Agency, Region 11, New York, New York for 1977. 

PERCENTO (percent of the white perch collected that were young-of-theyear) : 

No estimates of PERCENTO were available for Danskamner. Consequently,

all monthly values for PERCENTO were approximated based on data from 

Rosetan, which is adjacent to Danskamner. (See Table A-9 in this 

appendix. Monthly PERCENTO values tabulated for Danskamer are exactly

the same as those tabulated for Roseton for July 1973 - December 1377;

monthly PERCENTO values for January 1972 - June 1973 were calculated as 

the average of the 1975 and 1976 Koseton values for each month.) 

RATEO = PERCENTO RATE/100 and RATE1 = RATE - RATEO. 

NUMBERO = PERCENTO 9 iJUMBERj100 and NUMBER1 = NUMBER - NUMBERO. 

- 1All collection rates were converted from number of white perch collected per million gallons to number of white perch collected per

million cubic meters by multiplying by 264.17 gallons per cubic meter,

Collection rates were assumed to eqclal impingement mortality rates. 
11-40 

RATE, NUMBER, and PERCEIUTO are dzfined above. RATE0 and RATE1 are the 

collection rates for young-of-the-year and for yearling and older white 

perch, respectively. NUMBER0 and NUMBER1 are number collected for 

young-of-the-year and for yearling and older white perch, respectively. 
I 

I 

I 

1 

I 

I 

I 

I 

1 

I 

I 

I 

I 

1 

I 

'I 

I 

I 

I 

TEAR 

1972 

197 2 

1972 

1972 

1972 

1972 

1972 

1972 

1972 

1972 

1972 

1972 

1973 

1973 

1973 

1973 

1973 

1973 

1973 

197 3 

1973 

1973 

1973 

1973 

1971 

1970 

197U 

1974 

1970 

1974 

1970 

1974 

1979 

1974 

1970 

NOWTRI 

1 

2 

3 

U 

5 

6 

7 

8 

9 

10 

11 

12 

1 

2 

3 

0 

5 

6 

7 

8 

9 

10 

11 

12 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

1 

2 

3 

RRTE 

22-67 

11.23 

29.45 

137.32 

74U.57 

5U6. OU 

205.74 

253.3u 

172.82 

477.65 

273.37 

110. a5 

9.39 

3.22 

21.22 

203. 89 

352. 80 

167. 06 

485.17 

88.76 

171.21 

505.11 

U51. 36 

77.24 

20.3u 

1.29 

5.02 

669.35 

393.96 

381.57 

135. 89 

119.36 

53.18 

133.46 

137.7U 

203.51 

31.78 

15.01 

15.93 

253.95 

139.98 

321.57 

103. 5 

181.11 

150.26 

592.51 

667. US 

79.34 

u3.35 

32.76 

56.35 

1069.18 

250.5 1 

232.91 

ai?. 87 

25.05 

106.67 

553.73 

1329.25 

lU3.01 

21.77 

15.00 

152.08 

1135.41 

1205.75 

227.79 

66.07 

125.31 

117.20 

535.58 

067.00 

51.96 

lUl8ER 

703 

318 

763 

h5UU 

23669 

23235 

3596 

12723 

71U3 

19732 

11339 

3775 

29 1 

78 

719 

6 959 

15330 

7931 

25639 

726 

8631 

21 155 

17855 

2203 

625 

31 

153 

13511 

15508 

12326 

6 273 

'3959 

2302 

5577 

5857 

3525 

1006 

3uu 

22u 

3335 

3937 

10827 

U621 

3993 

6861 

25315 

26385 

2175 

122u 

755 

'1uuo 

25733 

88h5 

3363 

1387 

972 

U719 

13989 

39827 

'1589 

668 

363 

U263 

3517U 

U8386 

5309 

2725 

5323 

QUO8 

13326 

13191 1u93 

PERCENT0 RATE0 RkTE1 IlUlBERl 

66.0 14.959 7.736 259.3 

53.0 5.950 5.277 1u9.5 

59.3 17.378 12.077 31 U- 9 

UU.0 60.119 75.397 25Uk 6 

58.3 431.908 312.761 12 OUO. 6 

0.0 0.000 516.039 * 23235.0 

4.8 9.923 196.816 9230.6 

64.2 162.6UU 91.535 r55u. 8 

96.5 1U9.989 23.331 961.3 

88.6 Q23.191 51.052 22'49. 4 

35.3 232.931 40.142 1631.4 

73.8 81,512 23.939 989.1 

66.0 5.998 3.090 95.5 

53.0 1.708 1.515 36.1 

59.0 lU.292 9.932 29U.8 

UU.0 89.710 111.176 3897.0 

58.3 201.623 148.176 64UU.S 

0.0 0.300 157.U91 7931.0 

4.8 23.288 461.886 29378.8 

6U.2 56.985 31.715 1691.9 

86.5 109.10 23.113 1165.2 

98.6 448.68 57.731 22.98. 8 

85.3 385.01 55,351 262U. 7 

73.8 57.01 20.238 589.0 

66.0 13.33 5.915 212.5 

53.3 0.69 0.608 17.4 

59.0 2.95 2.353 62.7 

uu.0 294.07 374.276 10926.2 

58.0 228.29 165.152 6513.U 

3.3 0.00 381.567 12926.0 

4.8 6.52 123. 355 537 1.9 

64.2 77.01 U2.946 2133.0 

86.5 U6.00 7.179 310.8 

98.6 119.13 15.329 749.8 

85.3 117.119 2). 2Y8 861.0 

73.8 147.97 52.532 2233.6 

59.9 19.00 12.72U 110 3. U 

35.6 5.70 10.310 221.5 

38.5 6.13 3.737 137.8 

7.0 17.78 236.170 3659.6 

17.2 2U.08 115.935 3259.8 

3.0 0.00 321.57P 11827.0 

2.8 2.90 113.552 UU91.6 

39.7 71.92 109.2UU 5366.1 

77.7 116.75 33.539 1530.0 

79.7 472.3 1 120- 300 5078.0 

76.2 508.5 0 153.851 6279.6 

66.0 52.17 26.873 739.5 

72.0 31.21 12.139 3U2.7 

70.4 23.06 9.696 226.7 

79.6 04. 95 11. $35 293.8 

91.0 861.99 202.195 U88U.7 

98.7 207-26 3. 257 115.0 

0.3 0.00 232.813 8363.0 

6.9 2.92 33.337 1291.3 

68.8 23.13 2.917 108.9 

95.3 101-65 5.010 221- 8 

97.5 539.88 13.603 497.2 

9u.a 125U.81 7>.138 2230.3 

81.5 11u.11 25.902 8U8.8 

66.0 lU.33 7.333 227.1 

53.3 7.95 7.052 170.6 

59.0 89.73 52. 35U 17U7.8 

44.3 500.02 636- 388 20257.U 

58.0 699.3U 505.315 20322.1 

3.0 0.00 227.741 5808.0 

U.8 3.17 52.939 2594.2 

64.2 80.25 UU. 752 1907.8 

86.5 101.31 15.827 595.1 

98.6 479-52 61.056 2055.0 

85.3 398.35 53.513 1939.1 

73.8 38.35 13.61U 390.4 

NU0 BE8 0 

493.7 

168.5 

453.1 

1399.4 

16627.0 

3.) 

465.U 

9 168. 2 

6178.7 

17U52.6 

9966.6 

2785.9 

185.5 

Ul. 3 

42u.2 

3362.3 

8899 I5 

3-3 

1229.2 

33 3c. 1 

7U65.9 

17866.2 

15230.3 

1659.0 

U 12.5 

19.6 

90.3 

8584 I8 

8Y9U. 5 

0.0 

301.1 

3825.0 

1991.2 

5827.2 

0996.3 

6291 -4 

602.5 

122.5 

86.2 

275.U 

677.2 

0.0 

129. U 

3532.9 

5331.3 

19937.0 

23105.4 

1435.5 

981.3 

539.3 

1146.2 

20826.3 

9730.3 

0.0 

95.7 

863.1 

uu97.2 

i939o.a 

37596.7 

3739.2 

auo. 3 

192.4 

2515.2 

15916.6 

28363.9 

0.0 

133.9 

3421.2 

3812-9 

15971.0 

11251-3 

1099.6 

1970 

1975 

1975 

1975 

1975 

1975 

1975 

1975 

1975 

1975 

1975 

1975 

1975 

1576 

1976 

1976 

1976 

1976 

1976 

1976 

1976 

1976 

1976 

1976 

1976 

1977 

1977 

1977 

1977 

1977 

1971 

1977 

1977 

1977 

1977 

1971 

1977 

U 

5 

6 

7 

8 

9 

10 

11 

12 

1 

2 

3 

U 

5 

6 

7 

8 

9 

10 

11 

12 
11-42 

REFERENCES FOR TABLE A-4 

1. Letter dated March 3, 1978, from William J. Cahill, Jr. of Consolida 

Edison Company of New york, Znc. (Con Ed) to Robert P. Geckler of th 

U. S. Nuclear Regulatory Comnission (US NRC), including a response t 

Question IX.l, which is the identification number for a question in 

Enclosure 2 of a letter dated July 26, 1977, from George W. Knighton 

(US dRG) to William Cahill, Jr..,(Con Ed). .-, 

2. Letter dated April 14, 1978, fro@Kenneth L. Marcellus of Consolidat 

Edison Company of New York, Inc. {Con Ed) to Henry Gluckstern of the 

U. S. Environmental Protection Agency (US EPA), including a response

Question A-5, which is the identification number for a question in t 

enclosure of a letter dated March 23, 1978, from Henry Gluckstern 

{US �PA) to Kenneth L. Marcellus (Con Ed). 

3. Letter dated October 31, 1977, from Kenneth 1. Marcellus of 

Consolidated Edison Company of New York, Inc. to Henry Gluckstern of 

the U. S. Environmental Protection Agency, including in Attachment 2 

response to Question 7 (9/27/77) of Attachment C which accompanied t 

October 12, 1977 EPA “Motion to Specify Area of Requestors’ Testimon 

To Be Cross-Examined During Initial Phase of Hearing.” 
I 1-43 

TABLES A-5, A-6, A-7 

WHITE PERCH IMPINGEMENT DATA FOR 

INDIAN POINT UNITS 1, 2, AND 3 

RATE (collection rate) :1 

June 1972 - December 1975: Copied directly from data-sheets 

provided in Ref. (I). 

January 1976 - December 1977: Copied directly from data 

sheets provided in Ref. (2). 

NUMBER (number co 11ected) : 

Maly 1972 - December 1976: Copied directly from appendix

taibles in Refs. (3) - (6). However, if a NUMBER value in 

these Texas Instruments (TI) appendix tables was lower than 

thle corresponding NUMBER value in Refs. (1) and (2), then the 

updated NUMBER value in Refs. (1) and (2) was used. For 

example, such substitutions were made for Indian Point Unit 2 

(Table A-6 in this appendix) for all months of 1973. In 

general, the NUMBER values prssented in the TI appendix

tables are the same as or higher than the NUMBER values 

presented in Refs. (1) and (2), for the reason discussed by Caln Edison in their response to Question VI.2 in Ref. 1. 

Thus, the substituted, higher values from Refs. (1) and (2) 

can still be low, because they were selected by TI to include 

only data that represented known flow volumes and associated 

impingement collections. 

January 1977 - December 1977: Copied directly from data 

sheets proveded in Refs. (7) and (8). 

PERCENTO (percent of the white perch collected that were young-of-theyear) : 

June 1975 - December 1976: Calculated from data on magnetic 

tapes provided by Consolidated Edison. The two tapes used 

were Texas Instruments 1975 Impingement Data (Record Type D )

arid Texas Instruments 1976 Impingement Data (Record Type 0).

Mainthly estimates of PERCENTO were calculated for each unit 

fctr which there were white perch impingement data as follows: -

E Number of impinged white perch in Lenqth Class 1 . Total number of impinged white perch , 
I 1-44 

where the bounds on Length Class 1 are 0 m to DIVISION, where 

DIVISION is the seasonally-varying, total body length in 

millimeters which is used as the cut-off length between 

young-of-the-year and yearling white perch (see Table A-10 of tl 

appendix). 

RATEO =’PERCENT0 RATE/100 and RATEl = RATE - RATEO. 

NUMBERO = PERCENTO NUMSER/100 and NUMBER1 = NUFIBER - NUMBERO. 

RATE, NUMBER, and PERCENTO are defined above. RATEO and RATEl are the 

collection rates for young-of-the-year and for yearling and older white 

perch, respectively. NUMBERO and NUMBER1 are number collected for 

young-of-the-year and for yearling and older white perch, respectively. 

IAll RATE values are given in the original sources in units of number 

of white perch collected per million cubic meters, and thus multiplication by 264.17 was not necessary. 

Collection rates were not assumed to equal impingement mortality rates. 

Rather, the collection rates were adjusted upward to account for the 

calculated efficiencies of less than 100%- For Units 1 and 2, RATE = 

RATE/O.15 (i.e., 15%efficiency) and for Unit 3, RATE = RATE/0.70

(i.e., 70% efficiency). These efficiency estimates are based on data 

presented in Ref. (9) for Units 2 and 3; Unit 1 was assumed to have the 

same collection efficiency as Unit 2, since Units 1 and 2 have similar 

intake structures. 
11-45 

TABLE A- 5 (conti nued) 

PELR nONTH BnrE NU!IBER PEBCESFO RATE0 BATE1 N UlBE R 0 IIURBER1 

197 2 S 1927 94.4 1819 iai.9 

197 2 6 65.80 11 320 0-0 0: 00 55. 310 3 11 320.0 

1912 7 52.70 2127 45. 1 23.6 3 213.768 9 59 1167.5 

1972 B 232.9 3 10560 81. e 197.53 35.836 e955 1605.1 

1972 9 380.37 12337 89.5 321.16 58.910 . "'16213 1873.0 

1972 10 2236.00 e4607 9u.o 2ioi.e~ 131.153 79533 5076. 4 

1972 11 1705.50 35333 36.7 1649.32 56.285 347U0 1185.0 

1972 12 8U0.20 11U20 96.4 ei3.ei 33.331 16793 627.1 

1973 1 62.40 7333 94.0 58.66 3.740 7957 U76.0 

1973 2 6U 540 97.3 62197 1192.6 

1973 3 20su33 91.1 1 88030 18369.6 

1973 163253 97.8 159662 3S91.6 

1913 5 ess:so 21533 94.4 836. o 1 09.594 i947e 1155.5 

197 3 6 186.27 US27 0.0 0.00 1%. 257 3 4526.7 

1973 7 2543 45. 1 llS6 1399.5 

1973 5 11- 53 15367 ea. e 9.79 1.153 -13331 2335.7 

1973 9 1963 84.5 1239 226.3 

1973 10 287 9U.O 269 17.2 

1973 11 4273 96.7 4132 141.0 

1973 12 i2ie7 96.4 11793 438.7 

1974 1 3798.37 32137 34.3 3 570.1 B 227.684 301 BO 1926.9 

1979 2 1661.33 @US67 97.3 1616.88 41.856 03363 1203.3 

1914 3 1680.33 33213 91.1 1530. 7e 149.550 39367 3er6.0 

191a 

1974 

u 

5 

1826.13 

591.57 

S6220 

15593 

97.6 

94.4 

1785.96 

56 1.37 

43.175 

33.301 

suge3

1 4e02 

1236. e 

87e.i 

191u 

1974 

6 

7 

161.20 

35.73 

76U7 

1513 

0.0 

45.1 

0.00 

16.12 

161.2)3

i9.6ie 

3 

110 

7646.1 

863.8 

1910 e 22.60 1140 84.0 19.16 3.u35 967 173.3 

1974 9 6'5.20 2973 94.5 so. e7 9.331 2512 560.9 

1979 10 631. e7 30227 9u.o 593.95 31.912 28113 181 3.6 

1979 11 e95. 00 15733 36.7 866.43 29.568 ;5214 519.2 

19111 12 62U1. 47 iu3e67 96.4 6016-71 22%. 593 i3e687 5 179.2 

1975 1 9255.13 62037 99.3 3999. e3 255.308 58286 3720.0 

1975 2 6960.67 t02U~f 97.3 6776.52 193.316 99681 2766.1 

1975 3 2463.07 33213 91.1 2241.12 218.946 35723 3490.0 

1975 9 0757.2 0 lU073 97.8 U652.59 13r.653 72uuu 1629.6 

1975 5 471.73 5193 94. 4 US5.32 26.917 4890 290-1 

191s 6 5B. 27 827 0.0 0.00 59.257 3 826,. 7 

1975 7 -63.97 437 66.0 92.15 21.115 z6e 130.3 

1975 8 63.13 287 90.9 57-39 3. 735 26 1 26.1 
11-46 

TABLE A-6 (continued) 

YEAR UONrtt arr E 10~818 PER Z E R T3 R4 TEO RAlEl NIlaBER3 WOK BER' 

1972 

1972 

6 

9 

42. 0 

34.3 

960 

1347 

0.0 

84.5 

0.0 

29.0 

$2. 43 

5. 31 

3 

1138 

96( 

20s 

1972 10 135. 1 1687 9b. 0 127.0 3.11 1595 10' 

1973 1 3869.1 7933 94.0 363 6 .,0 23 2.09 7457 U75 

1973 2 U578.3 6 3593 97.3 U4 jS.7. 123.62 61970 1721 

1973 3 4280.1 2)1547 91. 1 3899.2 380.93 183609 1793E 

1973 1 U696.1 117680 97.8 U592.8 133. 31 11503 1 2585 

1973 5 1136.1 23563 94.4 1072.4 6 3.62 19409 li51 

1973 6 97.9 4527 0.0 0.0 37.33 3 a521 

1973 7 38.6 2513 4s. 1 17.4 21.19 1146 1391 

1973 8 187.0 15180 8U.8 158.5 29-12 12873 230; 

1973 9 31.3 lS53 84.5 26.9 4. a5 1228 225 

1973 10 5.3 287 9U.O 5.3 3. 32 25 9 li 

1973 1% 273.3 9233 96.7 264.3 9.02 4061 134 

1973 12 1260.1 12187 96.U 1218.6 35.51 117U9 431 

1974 1 12811.7 197813 94.0 12095.8 768.88 138945 8865 

1970 2 12823- 3 153027 97.3 12U77.1 305.23 108835 013; 

1974 3 9218.7 259980 91.1 8398.2 820.46 236842 23135 

1970 (I 8378.7 U71607 97.8 8190.3 19u. 33 U61270 1037t 

1974 5 4351.4 395843 94.4 U107.7 24 3.68 373673 22163 

197u 6 u2o. 5 09560 0.0 0.0 a23.53 3 u9561 

1974 7 92.3 0753 us. 1 19.1 23. 2U 2194 261i 

1970 8 69.7 8160 84.8 59.1 11-53 6923 12uc 

1970 9 206.0 23363 84.5 174.1 31.93 19739 3621 

1970 10 805.3 75780 9u.o 757.0 18-32 71233 05u; 

1974 11 1897.3 165967 96.7 1825.1 62.28 161157 5511 

1970 12 6787.3 370153 96.0 65U3.0 204. 34 356828 1332f 

1975 1 4416.0 212397 94.0 Ul51.0 264.96 199643 1274: 

1975 

1975 

2 

3 

3U96.1 

3171.2 

165833 

3 3973 

97.3 

91.1 

3001.7 

2889.0 

9u. 33 

282.24 

16 1356 

81966 

407[ 

800E 

1975 6 5900.1 U51100 97. 8 5770.3 129.91 441176 9921 

1975 5 837.0 33373 94. 4 761.8 US. 19 787011 4665 

1975 6 90. s 12207 0.0 0.0 93. u7 I 1220-

1975 7 92.7 11713 56.4 52.3 40.90 6 606 510; 

1975 8 1030. 1 89720 98.5 ioia.7 is. as 8837'4 1391 

1975 9 600.0 73693 95.0 608.0 32.00 70009 3 685 

1975 10 657.5 07720 95.8 629.9 27.61 45716 2001 

1975 11 1729.9 173343 95.2 1695-9 82.99 170732 860t 

1975 12 2807. 1 290000 97.9 2787.3 59.73 287826 6171 

1976 1 9597.3 610213 94.0 9021.5 575.84 573626 36612 

1976 2 3731.8 180087 95.6 3557.6 158. 23 172163 7921 

1976 3 1563.0 123327 91.1 1423.9 139.11 112077 109UI 

1976 0 245.0 287 97.7 239.U 5. 64 293 

1976 6 36.9 493 0.0 0.0 36.93 0 49: 

1976 9 290.3 8227 90.7 263.3 27.33 7U6 2 761 

1976 10 2332. 7 256333 95. 4 2225.4 107.30 244587 11791 

1976 11 lU32.5 20900 98.3 lU09.~ 20.35 20545 35! 

1976 12 22551.3 530523 94.1 21220.8 1330.53 649779 4074' 

1977 1 36380.7 2 16 0 710 9u.o 30197.8 2132. 9U 21 3U856 129881 

1977 2 681t53.3 1251797 97.3 66605.1 18U8.21 1227718 3r106L 

1977 3 5005.5 ~S~UFJO 91.1 1560.0 ins. $9 U17675 uo 80: 

1977 U 10519.3 2373U7 97.8 10317.2 232.09 232125 522; 

1977 5 339- 73 25353 94. 4 320.7 1 19.025 2U59U 1U59.( 

1977 6 299.87 37567 0.0 0.33 293.957 3 37566.. 

1977 

1977 

7 

8 

101.47 

U63.07 

947 

43U60 

45. 1 

W.8 

47-11 

392.59 

57. 352 

71.335 

U27 

36854 

519.-

6605. ' 

1977 9 lU6.87 22323 34.5 12u. 10 22.764 19367 3552.t 

1977 10 206U. 00 322080 94 .O 19U9.16 123333 333131 193U8.1 

1977 11 917 3 -6 7 333973 36.7 9 U40.2 3 322.432 9oe95~ 31019.' 

1977 12 543500 96.0 323373 19567.1 
11-47 

TABLE A-7 (continued) 

TEIR uowrH SATE NOJBBR P ERZE#TO RITE0 BkTEl YO n BEU~ UlfIElEUl 

1970 3 38.93 6 91.1 35.36 3.055 5 0.5 

1979 9 993.84 1371 97.8 977.95 21.997 4275 96.2 

197~ 5 058.90 677 94.0 u33.20 25.638 633 37.9 

1970 6 89 -73 1433 0.3 0.30 89.729 0 1030.0 

1970 # 7 5.71 20 U5.l 2.58 3.137 3 11.0 

19711 8 3.53 3 98.8 0.53 0.096 2 0-4 

197u 9 2.20 13 80-5 1.96 1.331 11 2-0 

1970 10 13.13 93 94.0 17.98 1.108 85 5.9 

1976 2 006.86 3970 99.0 u02.39 X.Uj9 3935 39.7 

1976 4 333.39 0550 97.8 326.0 5 7.330 445u 100.2 

1976 

1976 

5 

6 

105.57 

25.51 

7373 

225% 

98.0 

3.0 

99.5 6 

0.00 

5.312 

26.514 

6963 

0 

U12-9 

2250.3 

1976 7 16.81 1509 13.0 2.19 19.523 196 1312.5 

1976 8 05.r3 ai73 64.9 29.08 15.905 2706 1463~7 

1976 9 39.27 3199 67.8 26.53 12.605 2169 1029.9 

1976 10 221- 57 21355 90.9 201.41 20.163 19876 1989.8 

1976 11 1332.03 118093 96.6 1286.7U as.239 llUU6U 0028.6 

1976 12 819.24 56426 97.2 796.30 22.939 54946 1579.9 

1977 1 1953. 03 92889 98.0 I836.22 111.236 97315 5573.3 

1977 2 56% 7 1 121396 97.3 5503.98 152.731 123956 3939.7 

1977 3 352. 0 7 29318 91.1 321.10 31.310 26705 2609.0 

1977 4 559-00 35913 97.8 506.70 12.298 55569 1250.0 

1977 5 3U6. 0 1 62640 90.0 327.02 13.339 59132 3507.8 

1977 6 87.86 11373 0.3 0.00 84.857 0 11370.0 

$977 7 32.23 0 756 05.1 14.50 17.633 2105 2610.9 

i977 8 9P.36 13193 84.8 19.76 14.297 11179 2003-8 

1977 9 00-06 5931 8U.5 33.195 5.213 50 12 919.0 

1977 10 119.64 031) 94.0 112. 96 7.179 3769 290.6 

1977 12 510.26 1812u 96.u U95.78 19.513 17072 652.5 
I 1-48 

REFERENCES FOR TABLES A-5, A-6, AND A-7 

1. Letter dated March 3, 1978, from William J. Cahill, Jr. of 

Consolidated Edison Company of New York, Inc. (Con Ed) to Robert 

P. Geckler of the U, S. Nuclear Regulatory Conmission (US NRC), 

including a response to Question VI.3, which is the identification 

number for a question in Enclosure 2 of a letter dated July 26, 

1977, from George We Knighton (US NRC) to William Cahill, Jr. (Con 

Ed), 

2. Letter dated May 3, 1978, from Kenneth L. Marcellus of Consolidated 

Edison Company of New York, Inc. (Con Ed) to Henry Gluckstern of 

the U. S. Environmental Protection Agency (US EPA), including a 

response to Question A-3, which is the identification number for a 

question in the enclosure of a letter dated March 23, 1978, from 

Henry Gfuckstern (US EPA) to Kenneth L. Marcellus (Con Ed). 

3. Texas Instruments, Inc, Indian Point Impingement Study Report for 

the Period 15 June 1972 through 31 December 1973. Prepared for 

Consolidated Edison Company of New York, Inc., December 1974. 

(Tables A-1.5 through A-1.8). 

4, Texas Instruments, Inc. Indian Point Impingement Study Report for 

the Period 1 January 1974 through 31 December 1974. Prepared for 

Consolidated Edison Company of New York, Inc., November 1975. 

(Tables B-2 through B-4). 

5. Texas Instruments, Inc. Indian Point Impingement Study.'Report for 

the Period 1 January 1975 through 31 December 1975. Prepared for 

Consolidated Edison Company of New York, Inc., November 1976. 

(Tables A-4 and A-5). 

0, Texas Instruments, Inc. Hudson 8iver Ecological Study in the Area 

of Indian Point, 1976 Annual Report. Prepared for Consolidated 

Edison Company of New York, Inc., December 1977. (Tables A-2 and 

A-3 ). 

7. Monthly letters from Eugene R. McGrath of Consolidated Edison 

Company of New York, Inc. to Peter A. A. Berle of the New York 

State Department of Environmental Conservation, which are sent as 

specified in Section 401 Certification and which include data 

sheets giving daily fish counts by species for each unit at Indian 

Point. 

8. Monthly letters from William J. Cahill, Jr. of consolidated Edison 

Company of New York, Inc. to James P. O'Reilly of the U. S. 

Nuclear Regulatory Conmission, which are sent as specified in 

Appendix B of Unit Nos. 1, 2 and 3 Technical Specification5 and 

which include data sheets giving daily fish counts by species for 

each unit at Indian Point, 

c 
11-49 

Exhibit UT-105. Table 1. Sumnary of Collection Efficiency Tests and 

Related 95% Confidence Intervals at Indian Point Units 2 and 3,

1974-1977. U. S. Environmental Protection Agency, Region 11,

Adjudicatory Hearing, Docket No. C/II-WP-77-01, introduced into 

evidence on June 6, 1978; 
11-50 

TABLE P.-8 

WHITE PERCH IMPINGEMENT DATA FOR THE 

LOVETT GENERATING STATION 

January 1973 - December 1976: Ref. (1) 

Values for RATE (collection rate)l and NUMBER (number collected) 

were taken directly from data sheets in Ref. (1). 

January 1977 - December 1977: Ref. (2) 

Values for RATE (collection rate)l and NUMBER (number collected) 

were taken directly from data sheets in Ref. (2). 

PERCENTO (percent of the white perch collected that were young-of-theyear) : 

No estimates of PERCENTO were available for Lovett. Consequently, al' 

monthly values for PERCENTO were approximated based on data from Indi, 

Point, which is located only 1% miles upriver and across the river frt 

Lovett . 

June 1975 - December 1976 

Used the average of the observed monthly values for the units at 

Indian Point for the corresponding month and year (see Tables A-! 

to A-7 in this appendix). 

January 1973 - May 1975 and January 1977 - December 1977 

Used the monthly approximations calculated for Indian Point (samr

for all units at Indian Point) (see Tables A-5 to A-7 in this 

appendix) . 

RATEO = PERCENTO RATE/100 and RATEl = RATE - RATEO. 

NUMBER0 = PERCENTO NUMBER/100 and NUMBER1 = NUMBER - NUMBERO. 

RATE, NUMBER, and PERCENTO are defined above. RATEO and RATEl are the 

collection rates for young-of-the-year and for yearling and older white 

perch, respectively. NUMBERO and NUMBER1 are number collected for 

young-of-the-year and for yearling and older white perch, respectively. 

1Al1 collection rates were converted from number of white perch collected per million gallons to number of white perch collected per

million cubic meters by multiplying by 264.17 gallons per cubic meter. 

Collection rates were assumed to equal impingement mortality rates. 
1 

2 

3 

4 

5 

6 

7 

1 

2 

3 

4 

5 

6 

7 

11-51 

TABLE A-8 { conti nued) 

YElR nowra B&TE NOgBER P ER Z E H TO BLTEO RATE1 W31BER3 aG6BEB1 

1973 70, 60 3536 94.0 66.55 Y.2U9 3323.6 212.16 

1973 81.53 3595 97.3 79, U2 2.234 3468.2 SS. 90 

1973 222.a3 11055 91 -1 202.6 3 13.735 13371.1 563.50 

1973 195.511 3559 97.8 192.22 4.324 6380.5 168.52 

197 3 66.0U 2703 9u.u 62.3U 3.535 2551.6 151.37 

1973 u3.uo 2231 5.3 0.09 u9.400 0-0 22U7.03 

197 3 16.38 817 05.1 7.39 3.932 368.5 UU8. 53 

1973 6 65.36 3411 6U. 8 72.61 13.050 3745.6 673.36 

197 3 9 13.71 600 68.5 11.51 2.123 507.3 93.00 

1973 10 2-64 93 3U.O 2. 48 3.159 87 .a 5.56 

1973 11 182.12 6037 96.7 137. X3 1. 633 5637.8 199.22 

1973 12 399.55 17232 36.4 375.62 14.321 16669.5 622.51 

197'4 1 use. 33 20058 90.0 U30.33 27.533 1935U.5 1203. &8 

:974 2 399.16 12695 97.3 388-36 10.777 12352.2 342.75 

597U U 522.26 18635 97.6 510-77 11. U39 16U23.6 uia. 37 

1974 5 163.26 5293 9u.u 15U- 11 9.142 5893.4 3U9.6; 

'1970 6 U0.68 1519 0.0 0.30 U3.632 0.3 1519.00 

1974 7 5.98 1SU us. 1 4.05 U.931 83 .O 101.02 

197U 6 12.15 a92 6U.6 10.33 1.371 u 17- 2 711.78 

197U 9 13.57 396 9u. 5 8.93 1.636 334.6 61.38 

1911 10 108.80 2921 9u.o 102.31 5.533 21U5.7 175. 25 

197U 11 302.74 11753 96.7 292.75 9.990 11365.2 367.85 

1970 12 311.72 12071 96.0 300.50 11.222 11536.0 U34.56 

1975 1 853.36 35153 9u-3 799.39 51.022 33998.9 2170.14 

1975 2 121.52 a325 97.3 118.2U 3.231 U238.2 116-78 

1975 3 163.80 a213 31.1 153.78 15.02U 3870. 6 376.16 

1975 U SU6.3@ 1186U 97.8 53u. 28 12.319 11633.3 261.01 

1915 5 25.15 786 34.4 2U. 69 1. U65 742.0 uu.02 

1975 6 26.68 958 0.0 0.00 25.53 1 0.3 956.00 

1975 7 7.70 273 6 1-2 u. 53 2.670 167.1 105.92 

1975 6 U2.80 16U2 9u.7 U0.53 2. 259 1555.0 87.03 

1975 9 2V.30 612 35.3 23.09 1.215 609.9 32.10 

1975 13 30.38 977 95.6 29.10 1.276 9 36.3 U1.03 

197s 11 543.39 15522 95.2 514.55 25.90U 15824.1 797.66 

1975 12 143.97 a058 97.9 1UO. 95 3.323 U36U.U 93.62 

1976 1 362.71 11976 34.0 3UO. 94 21.762 11163.4 712.56 

1916 

1976 

2 

3 

u2.21 

93 - ou 

1265 

2532 

97.3 

91.1 

u 1. 13 

85.67 

1.131 

8.370 

1239.9 

2452.4 

3U. 16 

239.59 

1976 U 166.50 a765 97.8 182.UO 1.133 U660.2 1OU. 63 ' 

1976 5 3.19 93 3u. 4 7.73 0.459 85.0 5.01 

1916 6 26.68 610 0.0 0.03 25.531 0.3 6 10.00 

1976 7 15.30 221 13.3 1-34 8.963 28.7 192.27 

1976 8 17.70 55u 6U.9 11.39 5.212 359.5 194. us 1916 9 22.19 51u - 79.2 17.57 9.616 1107.1 105.91 

1976 10 12. u2 167 93.2 11.57 3.31u 155.5 11.35 

1976 11 570-08 13233 97.4 555.26 10.822 9930 .E 265.20 

1976 12 53u. 90 13166 95.6 511.11 23.538 12586.7 579. 30 

1977 1225.33 33633 9u.o 1152.28 73.553 37307.7 2391.34 

1977 751.96 13633 97.3 731.56 23.333 1326U. 3 .368.09 

1977 105.U6 1719 91.1 96.99 9. u75 1566.0 152.99 

1977 162.62 2783 97.8 159.05 3 - 578 2721.5 61- 23 

1977 21.24 370 34.9 20.05 1.169 349.3 20.72 

1977 209.355 4732 3.3 0.000 209.355 0-00 4732 -00 

1977 19.179 576 a5.1 8.550 13.523 259.78 316. 22 

1917 s 37,333 1338 su. 8 31.7U3 5.690 1193.95 2lU.02 

1977 9 u. 755 121 8U.5 lr.313 3.737 132.2u 18.76 

1977 

1977 

10 

11 

227.8U7 

U90. U05 

Si19 

9767 

3U.3 

96.7 

219.176 

U 70 - 22 2 

13.67 1 

15.133 

5187.66 

931111.69 

331.14 

-322.31 

1917 12 U2.716 569 96. B 41- 179 1.539 643.95 2U. 05 
11-52 

REFEREKES FOR TABLE A-8 

1. Letter dated March 3, 1978, from William 3. Cahill, 3r. of Consolidate 

Edison Company of New York, Inc. (Con Ed) to Robert P. Geckler of the 

U. S. Nuclear Regulatory Comnission (US NRC), including a response to 

Question X.l, which is the identification number for a question in 

Enclosure 2 of a letter dated July 26, 1977 from George W. Knighton

(US NRC) to William Cahill, Jr. (&on Ed). 

2. Letter dated May 5, 1978 from Edward G. Kelleher of Consolidated Ediso 

Company of Hew York, Inc. (Con Ed) to Henry Gluckstern of the U. S. 

Environmental Protection Agency (US EPA), including a response to 

Question A-4, which is the identification number for a question in the 

enclosure of a letter dated March 23, 1978 from Henry Gluckstern 

(US EPA) to Kenneth L. Marc2llus (Con Ed). 
1 

I 11-53 

1 TABLE A-9 

WHITE PERCH IMPINGEMENT DATA FOR ME . ROSETON GENERATING STATION

1 

RATE (collection rate) :1 

1 July 1973 - December 1976: average of the daily collection rates 

for each month were copied directly from data sheets in Ref. (1). 

January 1977 - December 1977: average of the daily collection i rates for each month were copied directly from data sheets in 

Ref. (2).

I NUMBER (number collected): 

I July-1973 - December 1976: copied directly from Table 10.2-14 of 

Ref. (3). 

January 1977 - December 1977: calculated from the monthly

collection rates (RATE) described imediately above and monthly 1 values of actual total plant intake flow in millions of gallons

foir the particular month (from data sheets provided by the U. S. 

Environmental Protection Agency, Region 11, New York, New York). 1 

PERCENTO (percent of the wh i te perch co 1lected that were young-of -theyear ) :

I January 1975 - December 1976: Calculated from monthly data on 

length-frequency in 1-centimeter length intervals of white perch

in impingement collections [from Tables 10.2-15 and 10.2-16 in 

Re,f. (3)j. The "DIVISION11criteria specified by Texas Instruments 

were used as the cut-off length between young-of-the-year and 

yearling white perch (see Table A-10 in this appendix). 

I 

'I July 1973 - Decenber 1974 and January 1977 - December 1977: 

calculated as the average of the -1975 and 1976 PERCENTO values for 

each month. I 

I RATE0 = PERCENTO RATE/100 and RATE1 = RATE - RATEO. 

NUMBERO = PERCENTO NtlMBER/100 and NUMBER1 = NUMBER - NUMBERO. -

I 

1 :lA11 collection rates were converted from number of white perch

collected per million gallons to number of white perch collected per

million cubic meters by multiplying by 264.17 gallons per cubic meter. 

Collection rates were assumed to equal impingement mortality rates. 

I 

8 
11-54 

TABLE A-9 ( continued) 

RATE, NUMBER, and PERCENT0 are defined above. RATE0 and RATE1 are the 

collection rates for young-of-the-year and for yearling and older white 

perch, respectively. NUMBER0 and NUMBER1 are number collected for 

young-of -the-year and for yearling and older white perch, respectively. 

.. 
11-55 

TABLE A-9 (continued) 

I 

I 

1 

I 

I 

1 

I 

1 

I 

1 

I 

I 

II 

TEAR UORTU RATE 83 CLBER 

NWBB E R1 

1973 7 9.272 31 77.1 

1973 8 98.030 980 350.8 

1973 9 U28.008 1390 147.7 

197 3 

1913 

$0 

11 

654. 270 

197.83 7 

4522 

1396 

515- 5 

293.4 

1973 12 27.521 rea 126-8 

197Q 

1911 

1 

2 

1.162 

0.000 

5 

0 

1.7 

0.0 

1974 3 0.923 5 2.1 

1970 P 108. 70 1 re97 2762.3 

1914 5 413.537 5272 2634.2 

1970 6 106.566 1105 1105.0 

1974 1 0.687 13 9.5 

1970 8 54.023 3263 1168.2 

1974 9 23.617 1131 152.7 

191u 

10 113.007 1038 118.3 

1979 111 188.829 12313 1810.0 

191U 'I2 lOU.030 7351 1926.0 

1975 1 18.228 1337 52U-1 

1975 2 1U. 31 6 1059 682.0 

1915 3 14.926 1307 643.9 

1975 P 340.092 23288 21657.8 

1975 5 764.314 ?US33 12088.0 

1975 6 19.707 1613 1613.0 

1915 7 42.928 3355 3156.8 

1975 8 128. U13 957 1 577 1.3 

1975 9 118.348 7934 1790.3 

1915 XI 142.960 33501 6808- 8 

1975 11 615.727 10351 9722.5 

1975 12 21.107 8UU 287.0 

1916 1 19.575 1333 282.2 

1916 2 39-71 2 2287 677- 0 

1916 3 17.719 1129 230;3 

1976 U 463.513 31 1193 598 3.7 

1916 5 202.719 23331 270.9 

1976 6 75.07 0 6455 6455.0 

1916 7 3.108 325 303.5 

1976 8 22.69 2 2100 235.2 

1976 9 28.927 23U6 110.3 

'1976 10 1 u0. 45 9 3921 288.2 

1976 11 563.316 23006 1288.3 

1976 12 63.976 3258 692.7 

1977 1 23.036 1696 576.6 

1977 2 13.31U 951 400.0 

1917 3 67.178 5183 2125.0 

1977 4 303.95U 15U96 9232-2 

1977 5 735.106 51 uua 21606. S 

1977 6 20.552 135U 1964.0 

1977 7 10.62 0 1000 955.8 

1977 8 2U8.326 25338 9239.3 

1977 9 78.2U7 72U8 978.5 

1977 10 lU2.493 13176 1160.1 

1577 11 119.U8U 7834 1151.6 

1977 12 32.342 2296 631.6 

PERCENT0 

u. 8 

6U.Z 

86.5 

88.6 . 

95.3 

73-8 

66.0 

53.0 

59.3 

uu.0 

59.3 

0.0 

4.8 

6U.2 

86.5 

86.6 

95.3 

73.8 

59.9 

35.6 

38.5 

1.0 

17. 2 

0.0 

2. 8 

39.7 

71.7 

79.7 

76.2 

66.0 

72.0 

10.4 

79.6 

81.0 

98.7 

0.0 

6.9 

88.8 

75.3 

97.5 

RZlFEO 

0.4U5 

63.192 

370.227 

579.593 

168.755 

U4PE1 

8.827 

35.238 

57.781 

70.537 

29.082 

7.212 

0,395 

3.333 

0.173 

33.273 

173.728 

136.556 

0.654 

13.313 

NUBBERO 

3.9 

529.2 

946.3 

0306.5 

1702.6 

357.2 

3.3 

0.3 

2.9 

21W.7 

3637.8 

0.3 

0.5 

239b. 6 

978.3 

319.7 

10503.0 

5025.3 

782.9 

20.315 

0.767 

0.000 

0.249 

65.129 

239.910 

0,300 

0.033 

39.583 

20.429 

38.103 

161.071 

76.770 

10.918 

5.097 

5.786 

23.806 

28.262 

0.033 

1.202 

50.980 

91.957 

353.039 

469.184 

13.931 

1u.094 

20.237 

14.152 

3.188 

1.933 

27.758 

27.256 

7.309 

3.221 

9.179 

315,296 

136.052 

13.737 

41.726 

17.033 

26.392 

93.921 

tU6.5U3 

7.116 

5.481 

13.275 

3.627 

33.157 

3.155 

75.610 

3.173 

2.5'12 

1.360 

3.51 1 

31.516 

11.817 

7.332 

6.258 

27. Sa3 

170.214 

303.71U 

20.552 

13.113 

88 

- 908 

13.553 

16.244 

17.552 

8.631 

377.3 

U03.1 

16 30.2 

2511.0 

0.3 

108.2 

3799.7 

6063.7 

267 32.2 

31128.5 

557.0 

725.8 

16 13.3 

698.7 

25509.3 

20570.1 

0.3 

22.5 

1864. 8 

2235.7 

9678.8 

21717.7 

2655.3 

1119.U 

451 .O 

3056.3 

7253.8 

29837-5 

0.0 

. ua.2 

16568.7 

6269.5 

9015.9 

5582.U 

169U.4 

375.1 a5 

239.564 

0.330 

0.235 

20.151 

27.567 

1 36.94 8 

531.770 

52.059 

15.209 

7.057 

39.635 

133.740 

526-35 1 

0.000 

0.510 

159.438 

67.59U 

126.249 

101.320 

2U. 31 1 

911.0 

81.5 

66.0 

53.0 

59.0 

04.0 

58.0 

0.3 

U.8 

64.2 

86.5 

98.6 

85.3 

13.8 

-
I 1-56 

REFERENCES FOR TABLE A-9 

1. Letter dated March 3, 1978, from William J. Cahill, Jr. of Consolidat 

Edison Company of New York, Inc., (Con Ed) to Robert P. Geckier of th 

U. S. Nuclear Regulatory Comnission (US NRC), including a response to 

Question IX.1, which is the identification number for a question in 

Enclosure 2 of a letter dated July 26, 1977, from George W. Knighton

(US NRC) to William Cahill, Jr. (Con Ed). 

2. Letter dated April 14, 1978, from Kenneth L. Marcellus of Consolidate 

Edison Company of New York, Inc. (Con Ed) to Henry Gluckstern of the 

U. S. Environmental Protection Agency (US EPA), including a response

Question A-5, which is the ideptification number for a question in th 

enclosure of a letter dated March 23, 1978, from Henry 'Gluckstern 

(US EPA) to Kenneth L. ivlarcellus (Con Ed). 

3. Ecological Analysts, Inc. Roseton Generating Station. Near-field 

Effects of Once-through Cooling System Operation on Hudson River Biot 

Prepared for Central Hudson Gas & Electric Corporation, .July 1977. 
11-57' 

TABLE A-10. "DIVISION" CRITERIA SPECIFIED BY TEXAS INSTRUFIENTS 

AS THE CUT-OFF LENGTH SETWEEN YOUNG-OF-THE-YEAR AND 

YEARLING LIHITE PERCH1 

DATE' (m) (m) 

750101 

750101 

95 

95 

1973-1974 ,. 760105 

760119 

105 

105 

1974-1975 

750116 95 760202 105 

750116 95 760216 105 

750201 95 760301 105 

750201 95 760315 105 

750215 95 760405 105 

750215 95 760419 105 

750301 

750301 

95 

!35 

760419 

760503 

105 

105 

750315 !35 760577 105 

750315 95 760607 50 1975-1976 

750401 

750401 

750415 

135 

95 

95 

760607 

700621 

760705 

50 

50 

50 

750415 95 760719 60 

750501 95 760802 60 

750501 95 760816 85 

750515 95 760816 85 

750515 -95 760830 100 

750601 29 1974-1975 760830 100 

750601 29 760913 100 

750615 50 760913 100 

750615 50 760927 100 

750701 50 760927 100 

750701 50 761011 100 

750715 60 761011 100 

750715 60 761025 100 

750805 a5 761025 100 

750805 85 761108 100 

750818 95 761108 100 

750901 

750915 

95 

100 

761122 

761206 

100 

100 

751006 105 761206 100 

751020 

751103 

105 

105 I 

761220 

761220 

100 

100 

751117 

751201 

751215 

105 

105 

105 i 

DIV I[ SION3 

YEAR CLASSES4 DATE^ DIV IS I ON3 YEAR CLASSES4 

- 'Obtained from computer data tapes entitled Texas Instruments 1975 Impingement

Data (Record Type E) and Texas Instruments 1976 Impingement Data (Record Type E). 

*The format for DATE is year-month-day. 

3The seasonally-varying,total body length which is used to discriminate between 

young-of-the-yearand yearling white perch. 

4The two year classes separated by DIVISIOI4.