i

Proposal for Information Collection  

San Onofre Nuclear Generating Station

Southern California Edison

Submitted In Compliance with  

316(b) Phase II Regulatory Requirements

October 2005

Prepared by: 

Dave Bailey, Associate Director 

EPRI Solutions, Inc 

dbailey@eprisolutions.com
ii

List of Acronyms 

BTA Best Technology Available 

CCC California Coastal Commission 

CDS Comprehensive Demonstration Study 

CRWQCB California Regional Water Quality Control Board, San Diego Region 

CWIS Cooling Water Intake Structure 

EPA Environmental Protection Agency 

FRS Fish Return System 

IM Impingement Mortality 

IM&E Impingement Mortality and Entrainment 

SCE Southern California Edison 

MSL Mean Sea Level 

MOU Memorandum of Understanding 

MRC Marine Review Committee 

NPDES National Pollutant Discharge Elimination System 

PIC Proposal for Information Collection 

PSIG Pounds per Square Inch Gauge 

SONGS San Onofre Nuclear Generating Station 
iii

Table of Contents 

Executive Summary............................................................ v

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

2 Description Of Facility .................................................... 4

3 Compliance Alternatives to Be Evaluated ....................... 6

4 Biological studies........................................................... 14

5 Summary of consultations with agencies....................... 15

6 Schedule for Information Collection ............................. 16

ATTACHMENTS 

A: Summary of Existing Biological Information and Sampling Plan for IM&E 

 Study 

B: Proposed Method for Evaluation of Environmental Benefits 

C: Written Fish and Wildlife and Other Regulatory Agency Correspondence 

 
iv

List of Figures 

Figure 1 - Schematic of SONGS submerged offshore intake and velocity cap.............................. 5 

Figure 2 - Top view of SONGS on shore cooling water intake structure and fish return system . 5 

Figure 3 – Illustration of cylindrical wedgewire screens (compliments of US Filter and Johnson)

................................................................................................................................................. 8 

Figure 4 – An estimated 49 modules slightly smaller than the sized shown in the photograph 

would be required for SONGS (photo compliments of US Filter and Johnson). ................... 9 

Figure 5 – Illustration of Ristroph fish collection bucket............................................................. 10 

Figure 6 – Photograph of fine mesh screen panels on a screen test device .................................. 11 
v

EXECUTIVE SUMMARY 

This Proposal for Information Collection (PIC) is submitted in compliance with the final 316(b) 

Phase II Rule (the Rule) for existing electric generating stations published in the Federal Register 

on July 9, 2004. This PIC provides the California Regional Water Quality Control Board, San 

Diego Region (CRWQCB-SD) with Southern California Edison’s (SCE’s) plans for: 

• conducting necessary biological studies, 

• evaluating alternative fish protection technologies, and 

• evaluating the Rule’s compliance alternatives. 

It is SCE’s intention to evaluate use of the full range of compliance alternatives based on the 

results of an impingement and entrainment study proposed for initiation in the spring of 2006. 

Based on the results of this study, a quantitative assessment of compliance alternatives will be 

conducted in 2007 to select the compliance alternative(s) to meet the Rule’s applicable 

performance standards. Additional studies will be conducted as necessary to gather the 

information to prepare the Comprehensive Demonstration Study for submittal to SWRCB on or 

before January 7, 2008. 

Receiving agency comments on the entirety of this PIC is important to SCE, but we recognize 

that agency resources are limited. A critical component of our 316(b) process is to conduct an 

Impingement Mortality and Entrainment Characterization (IM&E) study. Much of the rest of 

our evaluation of alternatives depends on the results obtained in the IM&E study, and sampling 

needs to be initiated as early as practical to ensure full evaluation of entrainment during a full 

fish spawning season (Pacific Ocean in the vicinity of San Onofre Nuclear Generating Station). 

Therefore, SCE specifically requests that CRWQCB-SD review and comment on the new study 

proposed and detailed in Section 4 and Appendix C of this PIC within the 60 day review period 

the Rule encourages for State’s to provide PIC comments to facilities. SCE is anxious to obtain 

feedback on other aspects of the PIC, but since they are not as time sensitive, discussion on 

those aspects can wait until the spring of 2006.
1

1 INTRODUCTION 

EPA signed into regulation new requirements for existing electric power generating 

facilities for compliance with Section 316(b) of the Clean Water Act on July 9, 2004 (the 

Rule). These regulations became effective on September 7, 2004 and are based on 

numeric performance standards1

. The Rule at 125.94(a) (1-5) provides facilities with five 

compliance alternatives as follows: 

1. A facility can demonstrate it has or will reduce cooling water flow commensurate 

with wet closed-cycle cooling and be determined to be in compliance with all 

applicable performance standards. A facility can also demonstrate it has or will 

reduce the maximum design through-screen velocity to less than 0.5 ft/s in which 

case it is deemed in compliance with the impingement mortality (IM) performance 

standard (the entrainment standard still applies). 

2. A facility can demonstrate that it has in place technologies and/or operational 

measures and/or restoration measures in place that will meet the applicable 

performance standards. 

3. A facility can propose to install new technologies and/or operational measures 

and/or restoration measures to meet applicable performance standards. 

4. A facility can propose to install, operate and maintain an approved design and 

construction technology. 

5. A facility can request a site-specific determination of BTA by demonstrating that 

either the cost of installing technologies and/or operational measures and/or 

restoration measures are significantly greater than the cost for the facility listed 

in Appendix A of the rule or that the cost is significantly greater than the benefits 

of complying with the applicable performance standards. 

All facilities that use compliance alternatives 2, 3 and 4 are required to demonstrate a 

minimum reduction in impingement mortality (IM) of 80% (125.94(b) (1)). Facilities 

with a capacity factor that is greater than 15% that are located on oceans, estuaries or the 

Great Lakes or on rivers and have a design intake flow that exceeds more than 5% of the 

mean annual flow must also reduce entrainment by a minimum of 60% (125.94(b)(2)). 

The Rule further requires that facilities using compliance alternatives 2, 3, and 5 prepare 

a Comprehensive Demonstration Study (CDS) as described at 125.95(b) of the Rule. 

There are seven components of the CDS and all facilities are required to submit 

components 1 (PIC), 2 (Source Waterbody Information if facility is on a river or 

reservoir), 3 (IM&E Characterization Study) and 7 (Verification Monitoring Plan). 

 

1

 Performance standards are found at 125.94(b) 
2

Facilities using compliance alternative 1 are not required to submit a CDS and those 

using compliance alternative 4 are only required to submit the Technology Installation 

and Operation Plan (TIOP) and Verification Monitoring Plan. All facilities that use 

compliance alternatives 2, 3 and 5 are required to prepare and submit components 1, 2, 3 

and 7 but depending on the compliance alternative(s) selected will submit either 

component 4 ( Design and Construction Technology Plan and Technology Installation 

and Operation Plan), 5 (Restoration Plan) or 6 (information to support site specific BTA 

determination). The first component required for submittal is the “Proposal for 

Information Collection” (PIC), the first component of the CDS. The Rule at 125.95(b) 

(1) requires that the PIC include: 

 

1. A description of the proposed and/or implemented technologies, operational 

measures, and/or restoration measures to be evaluated in the Study. 

2. A list and description of any historical studies characterizing impingement 

mortality and entrainment (IM&E) and/or the physical and biological conditions 

in the vicinity of the cooling water intake structures (CWIS) and their relevance to 

this proposed Study. If you propose to use existing data, you must demonstrate 

the extent to which the data are representative of current conditions and that the 

data were collected using appropriate quality assurance/quality control 

procedures. 

3. A summary of any past or ongoing consultations with appropriate Federal, State, 

and Tribal fish and wildlife agencies that are relevant to this Study and a copy of 

written comments received as a result of each consultation. 

4. A sampling plan for any new studies you plan to conduct in order to ensure that 

you have sufficient data to develop a scientifically valid estimate of IM&E at your 

site. The sampling plan must document all methods and quality assurance/quality 

control procedures for sampling and data analysis. The sampling and data 

analysis methods you propose must be appropriate for a quantitative survey and 

include consideration of the methods used in other studies performed in the 

source waterbody. The sampling plan must include a description of the study 

area (including the area of influence of the CWIS(s)), and provide a taxonomic 

identification of the sampled or evaluated biological assemblages (including all 

life stages of fish and shellfish). 

An important feature of the Rule is use of the calculation baseline. The calculation 

baseline is defined as follows: 

Calculation baseline means an estimate of impingement mortality and entrainment that 

would occur at your site assuming that: the cooling water system has been designed as a 

once-through system; the opening of the cooling water intake structure is located at, and 

the face of the standard 3/8-inch mesh traveling screen is oriented parallel to, the 

shoreline near the surface of the source waterbody; and the baseline practices, 

procedures, and structural configuration are those that your facility would maintain in 

the absence of any structural or operational controls, including flow or velocity 

reductions, implemented in whole or in part for the purposes of reducing impingement 
3

mortality and entrainment. You may also choose to use the current level of impingement 

mortality and entrainment as the calculation baseline. The calculation baseline may be 

estimated using: historical impingement mortality and entrainment data from our facility 

or another facility with comparable design, operational, and environmental conditions; 

current biological data collected in the waterbody in the vicinity of your cooling water 

intake structure; or current impingement mortality and entrainment data collected at 

your facility. You may request that the calculation baseline be modified to be based on a 

location of the opening of the cooling water intake structure at a depth other than at or 

near the surface if you can demonstrate to the Director that the other depth would 

correspond to a higher baseline level of impingement mortality and/or entrainment. 

This definition allows existing facilities with a variety of study options to take credit for 

facility features that deviate from the calculation baseline and provide the benefit of fish 

protection. Facilities can also simply develop the baseline by documenting IM&E. 
4

2 DESCRIPTION OF FACILITY 

San Onofre Nuclear Generating Station (SONGS) is located on the Pacific Ocean 

approximately 2.5 miles southeast of San Clemente California along the Southern 

California Bight in north San Diego County. The facility currently consists of two 

nuclear fueled generating units (Unit 2 & Unit 3) each rated at 1,087 MWe. SONGS is 

considered a baseloaded facility and in 2003, the average capacity factor for the entire 

facility was 96.9%. 

The design of the Cooling Water Intake Structure (CWIS) deviates significantly from the 

Rule’s calculation baseline. Deviations that provide the benefit of fish protection include 

use of an offshore submerged intake and velocity cap in combination with a fish 

collection and return system (FRS). Figure 1 shows the offshore intake and velocity cap 

while Figure 2 provides a plan view of the on shore CWIS and FRS. Units 2 and 3 each 

have submerged intakes located 3,183 ft offshore with the cooling water intake located at 

a depth of 32 ft. Condenser cooling water for each Unit flows through an 18 ft internal 

diameter submerged pipe to where the rest of the CWIS is located on shore within the 

facility. On shore the cooling water passes through a series of vanes and louvers located 

in front of the traveling screens. The louvers also function as bar racks designed to 

prevent large debris from entering the CWIS. The louvers and vanes are designed to 

encourage fish based on pressure differentials to move to a quiet water area at the end of 

the intake where the fish return system (FRS) is located. In addition to the louvers, a 

”fish chase” procedure using elevated temperatures is used to further force fish into the 

FRS collection area prior to heat treatments2. The cooling water for each of the two 

Units, after passing through the bar racks, passes through six traveling screens located in 

parallel. It then is pumped through each Unit’s four 202,750 gpm circulating water 

pumps where it flows to the condensers. The through-screen water velocity of the 

traveling screens is 3.0 fps. 

Because SONGS is located on the Pacific Ocean with a capacity factor in excess of 15% 

it is subject to both the impingement and entrainment performance standards. 

 

2

 Heat treatments are conducted approximately every 6 weeks at each unit to control the growth of fouling 

organisms such as mussels and barnacles. Water temperatures in the screenwell reach approximately 

105°F. during the heat treatment. Prior to the heat treatment, a “fish chase” is performed to get as many 

fish out of the system as possible. During the fish chase the water is heated to a sub-lethal temperature that 

agitates the fish enough to make them move to the fish return elevator for return to the ocean. 
5

Figure 1 - Schematic of SONGS submerged offshore intake and velocity cap 

Figure 2 - Top view of SONGS on shore cooling water intake structure and fish 

return system 
6

3 COMPLIANCE ALTERNATIVES TO BE 

EVALUATED 

In the strategic compliance plan submitted to the RWQCB, SCE expressed its preferred 

compliance alternatives for preparation of the Comprehensive Demonstration Study 

(CDS). Each of the Rule’s options and compliance alternatives to be evaluated for use at 

SONGS and some of the issues currently identified with these alternatives are discussed 

below. 

3.1 Existing Use of an Offshore Intake with a Velocity Cap combined with 

FRS under Compliance Alternative 2 to meet the IM Performance Standard 

The Rule specifically entitles facilities to take credit for deviations from the calculation 

baseline defined in Section 1 above that provide the benefit of fish protection. As 

discussed in Section 2, SONGS has a number of CWIS design and operational deviations 

specifically used to provide fish protection. These systems include: 

• Use of an offshore intake with a velocity cap 

• Fish guidance system using louvers and vanes 

• Fish heat chase operational procedures (guide fish to collection point) 

• Fish collection and return system (i.e. FRS) 

The effectiveness of these systems have been previously documented in NOAA 

Technical Report NMFS 76 (April 1989) and in “Review of Southern California Edison, 

San Onofre Nuclear Generating Station (SONGS) 316(b) Demonstration” (June, 1994). 

These reports indicate that the installed design features used in combination with 

operational features are achieving a high level of protection to impingeable organisms 

that are expected to meet the 80% - 95% IM reduction performance standard. 

SCE believes that the systems listed above may also provide some benefit to entrainable 

life stages. First, observations of the FRS indicated that in addition to impingeable life 

stages (defined in the Rule as species of fish and shellfish that cannot pass through 3/8 in 

mesh traveling screens) numerous larger entrainable life stages (defined in the Rule as 

species of fish and shellfish that will pass through 3/8 inch mesh traveling screens) are 

collected in the fish collection tray and transported offshore. SCE plans to collect data to 

quantify the species and life stage of these fish to determine the potential for credit 

against the entrainment performance standard. The proposed study is discussed in 

Section 4 of the PIC below. Secondly, SCE believes that due to the behavior of larger 

entrainable species such as anchovies (one of the dominant species entrained) 

entrainment may be reduced due to the location of the intake in the water column. This 
7

deviation of SONGS from the Rule’s calculation baseline will also be evaluated for 

potential credit. 

3.2 Use of Restoration under Compliance Alternative 3 to Meet the 

Entrainment Reduction Performance Standard 

The EPA final Phase II Rule provides that applicants may use restoration measures in 

addition to, or in lieu of, technology measures to meet performance standards or in 

establishing best technology available (BTA) on a site-specific basis. The basic 

philosophy of restoration is mitigation of fish losses at a CWIS by either direct 

supplementation (stocking) of a “species of concern” potentially impacted by the CWIS, 

or provision, protection and restoration of habitat that “produces” fish and thereby 

replaces those lost due to IM&E. 

SCE has negotiated with the California Coastal Commission (CCC) construction of a 

wetland restoration project to mitigate the entrainment impacts at SONGS. The 

agreement includes restoration of 150 acres of wetland restoration as part of the overall 

San Dieguito River Valley Regional Open Space Park project. Consistent with 

requirements for use of restoration the agreement includes funding of monitoring to 

ensure that the project goals are attained. Additionally, the project includes partial 

funding of a white sea bass fish hatchery that will provide additional restoration benefits. 

The planned coastal restoration project was designed to offset losses of mid-water fish 

species based on an IM&E analysis conducted in the 1980’s. SCE in conformance with 

the Rule is proposing to conduct new IM&E studies to establish the calculation baseline 

based on current data (see Section 4). Based on the new data SCE will verify that the 

planned restoration project in combination with the fish hatchery will be adequate to meet 

the performance standards, supplemented by the currently installed fish protection 

technologies and operational measures previously discussed3

. 

 

3.3 Use of Fish Protection Technologies and/or Operational Measures under 

Compliance Alternatives 3 and 4 

In conjunction with other state and federal agencies, SCE has evaluated use of additional 

fish protection technologies and operational measures. The last technologies evaluated 

were use of light and sound behavioral devices that act as fish deterrents to impingeable 

organisms. In October 2000 the CCC concluded that these devices were not effective and 

testing was no longer necessary. In the event that use of restoration measures is not 

 

3

 SCE is aware that use of restoration is currently the subject of Phase II Rule litigation. The Second 

Circuit Court ruled that restoration could not be used for compliance with the 316(b) Phase I Rule. Based 

on the Phase I litigation decision, EPA added significant text to the Phase II Rule to support its use in Phase 

II. SCE plans to monitor litigation developments in 2005 and early 2006. It is SCE’s current 

understanding that the Phase II Rule litigation decision should be rendered in spring 2006, approximately 

the same time that results of the proposed IM&E sampling data will become available. When both the 

IM&E study data necessary for restoration scaling and results of the litigation are available, SCE can 

quantitatively verify that the amount of restoration in the current agreement is adequate to meet the 

entrainment reduction standard. 
8

available for compliance to offset entrainment losses, SCE plans to continue to evaluate 

use of additional technologies, including use of narrow slot wedgewire screens and fine 

mesh Ristroph screens. Each is discussed as follows: 

Narrow-slot cylindrical wedgewire screens have the potential to reduce both 

IM&E. These screens would replace the existing velocity caps. Cooling water for 

each unit would be conveyed through 49 separate cylindrical wedgewire screens, each 

84-in. diameter, submerged, and mounted on intake pipes connected to the existing 

intakes (Figure 3 and Figure 4). Wedgewire screen are typically designed to meet the 

entrainment standard by using 0.5 mm slots. Depending upon the size of entrained 

organisms (determined from the results of the IM&E study or from historical 

entrainment sampling), larger slots may be as effective in reducing entrainment at a 

substantially lower cost. In addition, the industry standard design for wedgewire 

screens is a maximum slot velocity of 0.5 ft/sec which meets the IM standard using 

compliance alternative 1. The screens, as designed, have the potential to decrease the 

entrainment of fish eggs and larvae, but the degree of protection will vary by species 

and life stage and no testing has been conducted for species in the vicinity of SONGS. 

Figure 3 – Illustration of cylindrical wedgewire screens (compliments of US Filter 

and Johnson) 
9

Figure 4 – An estimated 49 modules slightly smaller than the sized shown in the 

photograph would be required for SONGS (photo compliments of US Filter and 

Johnson). 

The orientation of the screens relative to the existing pipes will depend on the 

currents in the area. The screens should be positioned parallel to the predominant 

current to lessen the affects of debris buildup and to facilitate cleaning. The spacing 

between screens and the length of the new pipe will depend on the screen orientation. 

An air backwash system, complete with necessary air compressors and controls, 

would be installed to clean the wedgewire screens. The air backwash system could 

be an effective method for maintaining the wedgewire screens in a clean condition. 

Local currents, resulting from tide changes and coastal currents in the area should be 

sufficient to transport debris and organisms away from the screens. Periodic manual 

cleaning for removal of biofouling agents would likely be necessary. However, it is 

important to note that these screens have yet to be deployed in a marine environment 

and demonstrating the ability of the air backwash system will be critical for a nuclear 

facility such as SONGS. 

Approach velocities at the wedgewire screens would be similar to tidal or other 

ambient currents. The maximum through-slot velocity would not exceed 0.5 ft/sec. 

Head losses through the screens should not exceed 1 ft (assuming biofouling would 

not be a significant problem). Except for the slightly lower water level, flow 

characteristics in the intake pipe leading to the screenbay would not be any different 

than the existing intake. Flow patterns to the pumps would not change from the 

existing conditions. 
10

The existing traveling screens would not be necessary and could be removed with 

narrow-slot wedgewire screens. The fish return system would also no longer be 

required. Because of the low through-screen velocity, wedgewire would 

automatically meet the IM standard via Compliance Alternative 1 (0.5 ft/sec throughscreen design velocity criterion). 

Install Fine-mesh Ristroph Traveling Water Screens. SCE will also evaluate 

replacing the existing 3/8 in. traveling water screens for both units 2 and 3 with new 

0.5 mm fine-mesh Ristroph screens (Figure 5 and Figure 6). Fine-mesh screens are 

typically designed with an approach velocity of 0.5 ft/sec to increase the survival of 

fish eggs and larvae. This velocity is about one-fourth the velocity approaching the 

existing traveling water screens. Due to exceeding the velocity criteria it will be 

critical to perform laboratory and/or field studies to verify that the survival of 

entrainable organisms is higher than the existing survival through the condenser 

system. If impingement survival of entrainable organisms is low, the screenhouse 

would need to be expanded to accommodate nine additional screens necessary to 

reduce the approach velocity. Such an expansion would require each unit to be 

shutdown for a substantial amount of time and would require considerable site work. 

For these reasons, expansion of the intake and installing more Ristroph screens is not 

considered to be a cost-effective solution. 

Figure 5 – Illustration of Ristroph fish collection bucket
11

Figure 6 – Photograph of fine mesh screen panels on a screen test device

Impinged organism would be removed from the fine-mesh Ristroph screens via a 

low-pressure spray wash (~10 psi) and washed into a fish return trough. This fish 

return trough could be tied into the existing fish return system. 

Northern anchovy eggs are broadcast throughout the water column and are typically 

found floating near the surface and therefore may be entrained in reduced numbers 

through the velocity cap. However, northern anchovy eggs should be large enough to 

be physically prevented from passage through fine-mesh screens. Larval length of 

northern anchovy at hatching is between 2.5 and 3.0 mm; therefore, the majority of 

larvae should be prevented from being entrained. A second factor to consider with 

fine mesh screens is that such screens result in the impingement of fish that were 

previously entrained. Use of fine mesh screens is a tradeoff. Some species and life 

stages benefit, but others might experience greater mortality than under existing 

conditions. These screens are beneficial from an organism protection viewpoint only 

if impingement survival for abundant species is relatively high and exceeds 

entrainment survival levels. Past studies show that anchovy have relatively low 

survival following impingement on fine mesh screens. Immediate survival of 

anchovy larvae was reported to be 31 to 66% when adjusted for control survival 

(depending upon velocity and duration of impingement) (Edwards et al. 1981). Postimpingement survival of bay anchovy (Anchoa mitchilli), which is in the same family 
12

as northern anchovy, has ranged from 0 to 37% (Brueggemeyer 1988; LMS 1987). 

Therefore, this technology may not be effective for reducing entrainment mortality 

for species entrained at SONGS. 

Use of an Approved Technology under Compliance Alternative 4. Currently use 

of wedge wire screens in rivers that meet certain criteria is the only named EPA preapproved technology. However the Rule provides a process that allows additional 

technologies to become listed pre-approved technologies. New technologies can be 

so designated by providing information to demonstrate that if installed in the 

waterbody type the technology would have little trouble meeting performance 

standard for which they are pre-approved. 

When results of the proposed IM&E sampling are available in 2006, if use of restoration 

measures are not available and SCE decides to comply using one or a combination of 

technology and/or operational measures, it may propose pilot studies in the 2006/2007 

time frame to verify performance. 

Now that the final 316(b) Rule is in place, a good deal of interest has been generated in 

developing new fish protection technologies. SCE plans to monitor the development and 

testing of new technologies for potential use. If other technologies more effective in 

terms of fish protection efficacy and cost-effectiveness become available, SCE will 

inform CRWQCB-SD that the new technology may be added to the PIC for evaluation at 

SONGS. 

3.4 Use of Site Specific Standards under Compliance Alternative 5 

SCE plans to evaluate potential use of both the cost-cost and cost-benefit tests under 

compliance alternative 5. Use of these alternatives are provided so that facilities are not 

required to pay costs that would be considered significantly greater than either the costs 

estimated by EPA for facilities or the economic value of the site specific environmental 

benefits that will be achieved. Should the evaluation of the current impingement 

reduction technologies and operational measures determine that the IM performance 

standard is not met or use of restoration for offsetting entrainment losses is not available 

these tests will be used to evaluate the cost of technologies. 

EPA, in developing the national cost of implementing the Rule, considered the cost for 

each Phase II facility to comply. If the actual cost estimated for a facility to meet the 

performance standard, based on a site specific analysis, is determined to be significantly 

greater than the cost estimated by EPA for the facility to comply, the facility can apply 

for a site specific standard under the cost-cost test. The site specific standard would be 

that achieved by the use of the best performing technology (i.e. achieve the highest level 

of protection) or operational measure that would pass the cost-cost test. 

The economic value of the environmental benefit of meeting the performance standards 

will also be evaluated under the cost-benefit test. This analysis cannot be conducted until 
13

the proposed 2005/2006 IM&E study is completed, since those data, in combination with 

previously collected IM&E study data, will serve as the basis for the environmental 

benefit quantification. A description of the method to be utilized for the cost-benefit test 

is provided in Attachment B. 
14

4 BIOLOGICAL STUDIES 

The Rule requires that a summary of historical IM&E studies and/or physical and 

biological studies conducted in the vicinity of the CWIS be provided, as well as, study 

plans for any new IM&E studies. IM&E studies were previously conducted at SONGS. 

Entrainment sampling was conducted at Unit 1 over a one year period that started in 

August 1979 and concluded at the end of July 1980. Units 2 and 3 were extensively 

studied from 1979 through 1986 by the Marine Review Committee to estimate 

entrainment losses due to operation of the SONGS. Weekly impingement sampling was 

conducted from 1983 – 1994 then frequency was reduced to monthly sampling from 1994 

– 1998 and was reduced again to quarterly sampling since 1999. Due to the age of 

entrainment studies, a new study is proposed to be initiated in 2006 and sampling will be 

conducted on a bi-weekly basis. Also, due to the reduced impingement sampling in recent 

years, SCE plans to conduct a year of impingement sampling at a biweekly sampling 

frequency. Proposed sampling will also include quantification of later entrainable stages 

collected in the FRS in order to establish credit towards the calculation baseline for 

entrainment reduction. The historical IM&E studies, other biological information and 

proposed new studies are fully described in Attachment A. 
15

5 SUMMARY OF CONSULTATIONS WITH 

AGENCIES 

The Rule requires that “a summary of any past or ongoing consultations with appropriate 

Federal, State, and Tribal fish and wildlife agencies that are relevant to the CDS and a 

copy of written comments received as a result of such consultations be provided”. The 

California Coastal Commission (CCC) has a long standing involvement in the evaluation 

of the effects of the SONG’s CWIS on local fish and shellfish. This involvement 

includes negotiating the currently planned restoration projects designed to mitigate 

effects of the CWIS to mid-water fish not addressed by the installed fish protection 

technologies and operational measures. There are numerous documents in the public 

record regarding these negotiations that have already been provided to the CRWQCBSD. Attachment C provides a copy of the most recent progress report. 
16

6 SCHEDULE FOR INFORMATION COLLECTION

The Rule allows facilities with NPDES permits that expire within four years of the date 

of publication of the Rule in the Federal Register (July 9, 2004) up to three and a half 

years to submit the fully completed CDS (125.95(2) (ii)). SCE considers this to be a very 

short timeframe and believes the full three and a half years will be required to complete 

all required elements of the CDS for SONGS. The Rule also requires a PIC to be 

submitted to the SWRCB prior to initiating new 316(b) studies. While the Rule allows 

facilities to initiate studies after PIC submittal, SCE realizes it prudent and reasonable to 

provide time for SWRCB to review and comment on the IM&E study plan. The Rule 

encourages that SWRCB provide comments within 60 days of PIC submittal to allow 

SCE time to make any necessary modifications prior to initiating the IM&E studies. 

In order to make a final compliance alternative(s) determination for SONGS, it will be 

necessary to evaluate the results of the one year 2005/2006 IM&E samples, along with 

the previously collected historical impingement and entrainment data. It is anticipated 

that after the conclusion of the one year of proposed IM&E data collection, it is likely to 

take a minimum of 4-6 months to complete the processing of collected entrainment data, 

input results into a database, review QA/QC information, and analyze the data for use in 

compliance decision-making. This should allow SCE to quantitatively evaluate the 

various compliance alternatives discussed in Section 3 of the PIC. Also, it is anticipated 

that within this time frame, the Court will issue a decision on the on-going Phase II 

litigation, so that any impact of that decision on the currently available compliance 

alternatives and compliance options can be considered in making SCE’s final compliance 

decision. If restoration is still available, SCE will verify based on the IM&E study results 

that the current restoration project in combination with the existing fish protection 

technologies and operational measures are adequate to meet the IM&E performance 

standards. The IM&E analysis also will allow quantification of the economic benefits in 

order to evaluate potential use of the compliance alternative 5 cost-benefit test based on 

technology and operational cost estimates developed in 2005 if necessary. Finally, the 

IM&E study results also may also be used to evaluate the feasibility, efficacy or cost of 

the alternative technologies and/or operational measures being evaluated. 

SCE then plans to use the remainder of 2006 and the early part of 2007 to conduct the 

necessary work to develop the information needed to complete the CDS. If restoration is 

to be used for compliance, a Restoration Plan will be prepared in conformance with the 

Rule based on the currently planned restoration projects. In addition, a Design and 

Construction Technology Plan and Technology Installation and Operation Plan will be 

prepared based on the currently employed fish protection technologies and operational 

measures, as well as a Verification Monitoring Plan. If use of site-specific standards is 
17

used for compliance, work on the necessary documents, including the Comprehensive 

Cost Evaluation Study, Benefits Valuation (if the Cost-Benefit Test is used) and SiteSpecific Technology Plan, would be prepared during this 2006-2007 period. 

The Rule recognizes that the CDS studies are an iterative process4

 and allows facilities to 

modify the PIC based on new information. SCE may request SWRCB approval of an 

amendment to this PIC, based on new information relative to technologies and 

operational measures, use of restoration measures, Phase II Rule litigation or subsequent 

Agency guidance. 

 

4

 See Rule preamble first column pg 41235 of Federal Register/Vol. 69, No. 131/Fri 7/9/04. 
 Appendix

A SUMMARY OF EXISTING BIOLOGICAL 

INFORMATION AND SAMPLING PLAN FOR IM&E 

STUDY 

See following pages. 
SUMMARY OF EXISTING BIOLOGICAL INFORMATION AND 

SAMPLING PLAN FOR 

THE IMPINGEMENT MORTALITY AND ENTRAINMENT 

CHARACTERIZATION STUDY AT 

THE SAN ONOFRE NUCLEAR GENERATING STATION 

Prepared for: 

Southern California Edison 

Prepared by: 

ASA Analysis & Communication, Inc. 

90 East Main Street, P.O. Box 57 

Washingtonville, NY 10992 

October 2005 
SAN ONOFRE IM&E SAMPLING PLAN 

A -i

SAMPLING PLAN SUMMARY 

An impingement and entrainment sampling plan is proposed for the San Onofre Nuclear 

Generating Station (SONGS or the “Station”), a 2,174-MW facility located in San Diego 

County, California on the Pacific Ocean. The station is subject to the Clean Water Act 

§316(b) Phase II Rule for its NPDES permit, which requires that impingement mortality be 

reduced by 80 to 95 percent and that entrainment be reduced by 60 to 90 percent, 

compared to a baseline level specifically determined for the facility. To comply with this 

Rule, the proposed sampling plan will provide information required to complete an 

Impingement Mortality and Entrainment Characterization Study. This sampling plan: 1) 

identifies existing data on the fish community in the vicinity of the cooling water intake and 

on impingement and entrainment occurring at the intake; 2) evaluates the sufficiency of 

these data to characterize current fish abundance, distribution, impingement, and 

entrainment at the intake; and 3) describes a work scope for impingement and entrainment 

monitoring. 

SONGS has a long history of extensive studies on the effects of its operation on the aquatic 

community and the performance of its cooling water intake system (CWIS) in reducing 

impingement losses. The Station’s CWIS differs from the hypothetical shoreline intake 

defined by the Phase II Rule for use as the “calculation baseline”. For example, SONGS 

has an offshore intake and incorporates fish protection measures, including a velocity cap 

and fish diversion and return system (FRS). Southern California Edison (SCE) has 

submitted assessments of entrainment and impingement impacts in prior §316(b) 

demonstrations for SONGS and numerous technical reports. These studies and 

assessments have been subject to extensive regulatory review which concludes that the 

intake is best technology available for reducing impingement impacts (SAIC 1994). 

Impingement abundance monitoring has been conducted every year since 1983, while 

entrainment abundance monitoring was conducted at Unit 1 in 1979 and 1980 and at Units 2 

and 3 from 1982 through 1986. 

Because there are no recent data on entrainment at SONGS, entrainment abundance 

monitoring is proposed to update the existing data to reflect present conditions in the 

SONGS study area and current operation of the station. In contrast, the impingement 

abundance monitoring data at SONGS is extensive. However, since recent impingement 

monitoring has been relatively infrequent (monthly or quarterly since 1994), additional 

impingement abundance monitoring is proposed to provide a current and comparable data 

set on both entrainment and impingement that adequately accounts for temporal variations 

throughout the year. Special studies on effectiveness of the fish diversion and return 

system are also proposed to update prior studies, and investigate the potential effectiveness 

of the FRS in reducing entrainment of late larval and juvenile fish. Data produced by the 

entrainment abundance monitoring will define the species and life stages currently being 

entrained, as well as their numbers and length distributions on a time (daily and annual) and 

per-volume-pumped (million gallons (MG) of cooling water) basis. Data produced by the 

FRS effectiveness studies will provide additional information to characterize FRS-related 

reductions in impingement and entrainment relative to the calculation baseline. 

The table below summarizes the proposed features of the impingement and entrainment 

sampling programs. 
SAN ONOFRE IM&E SAMPLING PLAN 

A -ii

SAN ONOFRE NUCLEAR GENERATING STATION SAMPLING PROGRAM SUMMARY

Program Duration Sampling Frequency Data Collected 

Impingement 

Monitoring 

1 year Biweekly – One 24-hour 

sample every two weeks, 

year-round plus heat 

treatments. 

Counts and biomass by species 

and life stage, length frequency, 

scale/otolith samples, specimen 

condition, collection efficiency, 

ancillary environmental and 

operation data 

Fish Chase 1 year Concurrent with all heat 

treatment operations at both 

Units 2 and 3. 

Estimated count and biomass of 

all identifiable fish and target 

invertebrates. 

Entrainment 

Monitoring 

1 year Approximately biweekly for 

one year; plankton net 

samples taken from intake 

screenwellTP

1

PT– 4 samples at 6-hr 

intervals covering a 24-hour 

period, year-round. Sample 

schedule may vary depending 

on heat treatment and 

maintenance outage 

schedules. 

Counts and densities (#/volume) 

by species and life stage, length 

frequency of target taxa, ancillary 

environmental and operation 

data 

Source Water 

Plankton 

Monitoring 

1 year Monthly at 6-hour intervals 

over 24-hour period, 

coinciding, when possible, with 

in-plant entrainment 

monitoring. 

Counts and densities of fish 

larvae and targeted invertebrate 

larvae by species and life stage, 

length frequency of target taxa, 

ancillary environmental and 

operational data. 

FRS Studies 

(impingement 

& 

entrainment) 

1-year Bi-weekly, concurrent with 

impingement samples. 

Samples netted from fish 

return elevator. 4 samples at 

12-hr intervals covering 24-hr 

period. 

Counts and biomass by species 

and life stage, length frequency 

of target taxa, and condition (i.e., 

any indication of impaired 

swimming ability in elevator. 

 

TP

1

PT A pilot study will be conducted to compare plankton net samples, taken as close as possible to the 

offshore intake, to samples taken in-plant at the circulating water pump inlet to determine the best 

sampling procedure. 
SAN ONOFRE IM&E SAMPLING PLAN 

A -iii

TABLE OF CONTENTS 

TU1.UT TUINTRODUCTIONUT ..........................................................................................................1-1

TU1.1UT TUPhase II §316(b) RequirementsUT ...........................................................................1-1

TU1.2UT TUIM&E Characterization StudyUT ...............................................................................1-2

TU1.3UT TUSampling Plan Objectives and OrganizationUT ........................................................1-3

TU2.UT TUBACKGROUND INFORMATIONUT..................................................................................2-1

TU2.1UT TUSource WaterbodYUT ...............................................................................................2-1

TU2.2UT TUIntake Design and OperationUT................................................................................2-1

TU2.3UT TUHistorical DataUT ......................................................................................................2-2

TU2.3.1UT TUImpingement StudiesUT........................................................................................2-2

TU2.3.2UT TUEntrainment StudiesUT .........................................................................................2-3

TU2.3.3UT TUFish Return System StudiesUT.............................................................................2-4

TU2.3.4UT TUFish Chase OperationsUT.....................................................................................2-5

TU2.3.5UT TUVelocity CapUT .....................................................................................................2-6

TU2.4UT TUSufficiency of Existing Information for IM&E Characterization StudyUT ...............2-7

TU3.UT TUFISH COMMUNITYUT.......................................................................................................3-1

TU3.1UT TUAquatic HabitatUT.....................................................................................................3-1

TU3.1.1UT TUIntertidalUT............................................................................................................3-1

TU3.1.2UT TUSubtidal SandUT ...................................................................................................3-1

TU3.1.3UT TUKelp BedsUT .........................................................................................................3-2

TU3.2UT TUCommunity CompositionUT ......................................................................................3-3

TU3.2.1UT TUProtected SpeciesUT ............................................................................................3-3

TU3.3UT TURepresentative Indicator SpeciesUT.........................................................................3-4

TU3.3.1UT TUNorthern AnchovyUT.............................................................................................3-4

TU3.3.2UT TUQueenfishUT .........................................................................................................3-5

TU3.3.3UT TUPacific SardineUT..................................................................................................3-5

TU3.3.4UT TUWhite CroakerUT...................................................................................................3-6

TU3.3.5UT TUKelp/Sand BassUT................................................................................................3-6

TU3.3.6UT TUSpiny LobsterUT....................................................................................................3-7

TU4.UT TUPROPOSED IMPINGEMENT MONITORINGUT...............................................................4-1

TU4.1UT TUImpingement SamplingUT.........................................................................................4-1

TU4.1.1UT TUImpingement Sampling Gear and DeploymentUT.................................................4-2

TU4.1.2UT TUImpingement Sample ProcessingUT.....................................................................4-2

TU4.2UT TUFish Return System SamplingUT..............................................................................4-2

TU4.3UT TUFish Chase Effectiveness SamplingUT.....................................................................4-3

TU4.4UT TURelevant Ancillary InformationUT..............................................................................4-4

TU4.5UT TUData AnalysisUT .......................................................................................................4-4

TU5.UT TUPROPOSED ENTRAINMENT MONITORINGUT ..............................................................5-1

TU5.1UT TUEntrainment and Source Water Sampling DesignUT................................................5-1

TU5.1.1UT TUEntrainment Sampling Gear and DeploymentUT..................................................5-1

TU5.1.2UT TUSource Water Sampling Gear and DeploymentUT ...............................................5-2

TU5.1.3UT TUSample ProcessingUT...........................................................................................5-2

TU5.2UT TUFish Return System studiesUT .................................................................................5-2

TU5.3UT TURelevant Ancillary InformationUT..............................................................................5-3

TU5.4UT TUData AnalysisUT .......................................................................................................5-3

TU6.UT TUQUALITY ASSURANCEUT ...............................................................................................6-1

TU6.1UT TUProgram ManagementUT..........................................................................................6-1

TU6.2UT TUData Generation and AcquisitionUT..........................................................................6-1

TU6.3UT TUAssessment and OversightUT ..................................................................................6-2

TU6.4UT TUData Verification, Validation and UsabilityUT............................................................6-3

TU7.UT TULITERATURE CITEDUT....................................................................................................7-1
SAN ONOFRE IM&E SAMPLING PLAN 

A -iv

LIST OF FIGURES 

TUFigure 2-1. Location of the San Onofre Nuclear Generating Station.UT .................................2-8

TUFigure 2-2. Aerial view of San Onofre Nuclear Generating Station.UT....................................2-9

TUFigure 2-3. SONGS Impingement 1983-2003.UT..................................................................2-10

TUFigure 4-1. Conceptual model for estimating baseline impingement losses at the San 

Onofre Nuclear Generating Station (proposed field studies shown in bolded boxes).UT..4-6

TUFigure 5-1. Location of In-Plant Entrainment Sampler.UT.......................................................5-5

TUFigure 5-2. Conceptual model for estimating baseline entrainment losses at the San Onofre 

Nuclear Generating Station (proposed field studies shown in bolded boxes).UT..............5-6
SAN ONOFRE IM&E SAMPLING PLAN 

A -v

LIST OF TABLES 

TUTable 1-1 EPA’s Comprehensive Demonstration Study (CDS) RequirementsUT...................1-4

TUTable 2-1 Estimated Number of Fish Impinged at San Onofre Nuclear Generating Station, 

2003UT............................................................................................................................2-11

TUTable 2-2 Estimated Monthly Impingement Based on Quarterly Sampling at San Onofre 

Nuclear Generating Station, 2003UT...............................................................................2-12

TUTable 2-3 Historical Summary of Plankton Studies at SONGSUT.........................................2-13

TUTable 2-4 Estimated Number of Fish Collected in Entrainment Samples at San Onofre 

Nuclear Generating Station, 1979-1980. Estimated Daily Entrainment (No. x 10UP

6

UP

) (SCE 

1983)UT...........................................................................................................................2-14

TUTable 2-5 Estimated Fish Entrainment At San Onofre Nuclear Generating Station, 1979-

1980. Daily Entrainment (No. X 10UP

6

UP

) From Monthly Samples (SCE 1983)UT ................2-15
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A1-1 Introduction 

1. INTRODUCTION 

ASA Analysis & Communication, Inc. has prepared this Impingement and Entrainment 

Sampling Plan for Southern California Edison as groundwork for compliance with SCE’s 

Clean Water Act Section 316(b) compliance obligations with the California Regional Water 

Quality Control Board, San Diego Region (CRWQCB) for the San Onofre Nuclear 

Generating Station (SONGS). SONGS is located on the Southern California coastline 

between San Clemente and Oceanside, CA. Under the Clean Water Act §316(b), an 

NPDES permit applicant must demonstrate that the location, design, construction and 

capacity of its cooling water intake structure represents Best Technology Available (BTA) for 

minimizing adverse environmental impact. The primary impacts of concern under §316(b) 

are entrainment of smaller aquatic organisms into the cooling water system and 

impingement of larger organisms onto traveling screens in the cooling water intake. 

However, other impacts associated with various technology or operating alternatives also 

are considered in reaching a BTA decision. 

1.1 PHASE II §316(b) REQUIREMENTS 

On July 9, 2004, the United States Environmental Protection Agency (EPA) published its 

final Phase II Rule promulgating regulations to implement CWA §316(b). The Phase II Rule 

applies to existing electric generating facilities (construction commenced prior to January 17, 

2002) that have cooling water intake structures (CWIS) with a design capacity of 50 million 

gallons per day (MGD), withdraw water from waters of the U.S., and use 25 percent or more 

of the water withdrawn for cooling purposes. SONGS fits this definition for a Phase II 

facility. Compliance with the Phase II Rule is based on achieving performance standards for 

reduction of impingement mortality and entrainment set by the EPA on the basis of facility 

location. The Rule requires that impingement mortality be reduced by 80 to 95 percent and 

entrainment be reduced by 60 to 80 percent, compared to a baseline level (i.e., the 

calculation baseline) specifically determined for the facility. As a result of being located on 

the Pacific Ocean and having a capacity utilization rate of greater than 15 percent, SONGS 

is subject to entrainment reduction performance standards, as well as impingement mortality 

reduction standards. 

The calculation baseline is a hypothetical condition representing an intake structure located 

at the surface and along the shoreline of the source waterbody. The hypothetical intake 

would have the screen face parallel to the shoreline and traveling screens with the standard 

3/8-inch mesh. The hypothetical intake would not have design elements or operational 

measures employed for the purpose of reducing impingement mortality or 

entrainment. 

Besides other documents required with the submission of a permit application, the Rule 

requires development of a Comprehensive Demonstration Study (CDS), unless the 

applicant can demonstrate that the facility’s intake cooling water flow is commensurate with 

a closed-cycle recirculating system (EPA Compliance Alternative #1). The CDS has several 

components, as outlined in Table 1-1. One component is a Proposal for Information 

Collection, which includes a sampling plan for any proposed field studies necessary to 

supplement existing information about the source waterbody, its fish and shellfish 

community, or current impingement mortality and entrainment rates. If it is determined that 

existing information might not accurately represent current impingement mortality and 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A1-2 Introduction 

entrainment rates, the sampling plan will address proposed sampling for the Impingement 

Mortality and Entrainment (IM&E) Characterization Study, a required component of the CDS. 

This Impingement and Entrainment Sampling Plan fulfills this requirement for SONGS. 

Additional biological monitoring might be desirable depending on the specific compliance 

approach being used. The existing intake design and operation at SONGS differs from the 

calculation baseline and incorporates extensive fish protection technology. Therefore, 

additional studies will be conducted and integrated with existing information to estimate the 

effectiveness of the SONGS intake for reducing impingement mortality and entrainment and, 

by inference, the impingement and entrainment for the calculation baseline. 

1.2 IM&E CHARACTERIZATION STUDY 

The IM&E Characterization Study is an integral part of the CDS and the overall 

determination of BTA compliance. The IM&E Characterization Study provides information 

needed for development of all subsequent parts of the CDS, including the Design and 

Construction Technology Plan, the Technology Installation and Operation Plan, the 

Restoration Plan (optional), a site-specific determination of BTA (if justified), and ultimately 

the Verification Monitoring Plan (Table 1-1). The IM&E Characterization Study provides 

data on the rates of impingement mortality (and entrainment, when applicable) currently 

occurring at the plant, as well as a foundation for estimating the calculation baseline, 

needed for determining the levels of impingement mortality (and entrainment) reduction 

being achieved at the plant, presently and in the future. The Rule requires that the IM&E 

Characterization Study provide: 

1. Taxonomic identifications of all life stages of fish, shellfish, and protected species in 

the vicinity of the CWIS and susceptible to impingement and entrainment; 

2. A characterization of these species and life stages in terms of their abundance and 

their spatial and temporal distribution, sufficient to characterize the annual, seasonal 

and diel variations in impingement mortality and entrainment; and 

3. Documentation of current impingement mortality and entrainment of these species 

and life stages. 

In addition to these basic requirements, the IM&E Characterization Study may provide 

information necessary for SCE to choose the appropriate Rule compliance alternative, such 

as applying for a site-specific determination of BTA. To justify this alternative, the results of 

the IM&E Characterization Study are needed to evaluate the benefits of implementing 

technology, operational, or restoration measures, in terms of the numbers or biomass of fish 

and shellfish potentially saved or replaced by their implementation. 

The EPA regulations allow impingement mortality and entrainment to be quantified either for 

all taxa or through the use of Representative Species (RS) as part of the compliance 

assessment. RS could be species most frequently observed in impingement and 

entrainment collections; species for which technology, operational modifications or 

restoration measures are directed; or species deemed to be most important because of their 

economic value (e.g., commercially or recreationally exploited species), value to the 

ecosystem (e.g., abundant prey species), or societal value (e.g., threatened or endangered 

species). RS also can be chosen as surrogates for other species not selected for detailed 

biological study. Since biological information necessary to complete analyses for the CDS 

are not available for all species, it is both more practical and more technically defensible to 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A1-3 Introduction 

base all analyses on RS. In this sampling plan, we address the selection of RS that could 

be used for SONGS. 

1.3 SAMPLING PLAN OBJECTIVES AND ORGANIZATION 

This Impingement and Entrainment Sampling Plan has been prepared to meet the following 

objectives: 

1. To identify and summarize existing data on the fish and shellfish community in the 

vicinity of the station’s CWIS; 

2. To identify and summarize existing data on fish and shellfish impingement and 

entrainment within the station’s CWIS; 

3. To evaluate the sufficiency of existing data to describe the current fish abundance 

and spatial and temporal distribution of fish in the vicinity of the station’s CWIS, and 

the current rates of impingement and entrainment; 

4. To make an initial selection of Representative Species; and 

5. To prepare a work scope for monitoring and testing programs required to supplement 

existing information on impingement and entrainment at SONGS. 

This sampling plan will be submitted to the CRWQCB as part of SCE’s Proposal for 

Information Collection (PIC) for SONGS. 

This sampling plan is organized to first present background information on the station, 

including the source waterbody (Section 2.1), the cooling water intake design and operation 

(Section 2.2), historical biological data (Section 2.3), and a discussion of the need for 

supplemental data for the IM&E Characterization Study (Section 2.4). Section 3 then 

describes the aquatic habitat and fish community in the vicinity of the station’s CWIS, using 

available historical data. Sections 4 and 5 describe the recommended sampling scope for 

impingement monitoring and entrainment monitoring, respectively. These program work 

scopes describe the recommended sampling design, sampling gear and its deployment, 

sample processing procedures, collection of any required ancillary information, and data 

analysis. Section 6 describes a quality assurance program that will address data quality 

concerns. 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A1-4 Introduction 

Table 1-1 EPA’s Comprehensive Demonstration Study (CDS) Requirements 

Requirement 

Proposal for Information Collection 

A description of the selected combination of intake technologies, operational measures, and/or 

restoration measures being evaluated 

A list and description of previous impingement/entrainment studies and/or studies on the physical or 

biological conditions in the vicinity of the CWIS and their relevance to the study 

A summary of past or on-going consultations with federal, state, or tribal fish and wildlife agencies 

and a copy of written comments 

A sampling plan for any new field studies proposed and documenting: 

• methods proposed and those used in similar studies in the same source water body 

• quality assurance/quality control procedures 

• description of the study area (including the zone of influence of the CWIS) 

• taxonomic identification of the sampled or evaluated biological assemblages 

(including all life stages of fish and shellfish) 

Impingement Mortality and Entrainment Characterization Study 

Taxonomic identification of the species and life stages of fish and shellfish in the vicinity of the CWIS 

that are most susceptible to impingement and entrainment 

A characterization of the species most susceptible to impingement and entrainment including the 

abundance and temporal/spatial characteristics 

If new information is needed to characterize IM&E, studies must be “of a sufficient number of 

years...to characterize annual, seasonal, and diel variations.” 

Samples used to support calculations of reduction of impingement mortality and entrainment; 

calculation of benefits must be conducted during periods of representative operational flows and flows 

must be documented 

Documentation may include historical data that are representative of the current operation and 

biological conditions 

Identification of threatened or endangered species protected under Federal, State or Tribal law 

Design and Construction Technology Plan 

Capacity and utilization rate of the facility and supporting documentation including: 

• average annual net generation of the facility over a 5 year period (if available) of 

representative operating conditions 

• total net capacity of the facility 

• calculations 

Explanation of the technologies and operational measures being used or to be employed to meet § 

125.94 

A narrative description of the design and operation of all design construction technologies or 

operational measures necessary to meet national performance standards, and information that 

documents the efficacy for application with the species and life stages expected to be most 

susceptible to impingement and entrainment (include all design calculations, drawings, and estimates 

to support descriptions) 

Calculations of the reduction of impingement mortality and entrainment of all life stages of fish and 

shellfish that would be achieved with the technologies or operational measures being adopted based 

on the Impingement Mortality and Entrainment Characterization Study described above (include all 

design calculations, drawings, and estimates to support descriptions) 

Documents demonstrating that the location, design, construction and capacity of the CWIS 

technologies reflect BTA 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A1-5 Introduction 

Table 1.1 (continued)

Technology Installation and Operation Plan 

A schedule for installation and maintenance of any new design and construction technologies 

A list of operational parameters that will be monitored, including location and monitoring frequency 

A list of activities to ensure the efficacy of the installed design and construction technologies and 

operational measures, to the degree practicable, and the implementation schedule 

Schedule and methodology for assessing efficacy of the measures in achieving applicable 

performance standards, including an adaptive management plan for revisions if the standards are not 

being met 

For pre-approved technologies (Compliance Alternative 4), documentation that appropriate site 

conditions exist for the technologies 

Information to Support Restoration Measures 

Explanation of why restoration measures would be more feasible, cost-effective, or environmentally 

desirable than by meeting performance standards or site-specific requirements wholly through use of 

design and construction technologies, and/or operational measures 

A list and narrative description of the restoration measures in place or proposed for implementation, 

including species targeted 

Quantification of the ecological benefits (production of fish and shellfish) from existing and/or 

proposed restoration measures, as well as a discussion of the nature and magnitude of uncertainty 

associated with the restoration measures and a discussion of the time frame for accrual of these 

benefits 

Design calculations, drawings, and estimates documenting that the restoration measures, alone or in 

combination with technology or operational measures, will meet the requirements for production of 

fish and shellfish 

An adaptive management plan to include: 

• a monitoring plan listing parameters that will be monitored, and describing the frequency of 

monitoring and criteria for determining success 

• list of activities to ensure efficacy of the restoration measures, the linkages between these 

activities and items in the monitoring plan, and an implementation schedule for the activities 

• a process for revising the plan if new information becomes available or if standards or sitespecific requirements are not being met 

A summary of past or on-going consultations with Federal, State, or Tribal fish and wildlife agencies 

and a copy of written comments 

If requested, a peer review of items to be submitted as part of the restoration plan 

A description of information to be included in a biannual status report 

Information to Support Site-Specific Determination of BTA

Comprehensive Cost Evaluation – including detailed engineering cost estimates of the technological 

or operational modifications proposed in the Design and Construction Plan above

Valuation of the Monetized Benefits of Reducing Impingement and Entrainment (if the site-specific 

determination is being sought because the costs are significantly greater than the benefits) 

containing: 

• description of methodology used 

• the basis for any assumptions and quantitative estimates 

• analysis of the effects of significant sources of uncertainty on the results
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A1-6 Introduction 

Table 1.1 (continued)

Site-Specific Technology Plan containing: 

• a narrative description of the technologies, operational measures, and restoration measures 

that you have selected and information that demonstrates the efficacy of the technology for 

species in the vicinity of the CWIS and supporting design calculations, drawings, and 

estimates 

• engineering estimate of the efficacy of the technological or operational measures for reducing 

impingement and entrainment – include site-specific evaluation of the suitability of the 

technologies or operational measures for reducing IM&E based on representative studies 

and/or prototype studies and supporting design calculations, drawings, and estimates 

• documentation that demonstrates the technologies, operational measures, or restoration 

measures selected would satisfy §125.94 (establishment of BTA) 

Most of this information will be developed in the Design and Construction Technology Report

Verification Monitoring Plan – two years of monitoring to verify full-scale performance of 

technologies, operational measures, or restoration)

Plan must include: 

• frequency of monitoring 

• duration of monitoring 

• description of yearly status report to be submitted to the Director 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A2-1 Background Information 

2. BACKGROUND INFORMATION 

This section provides a summary of available information on the San Onofre Nuclear 

Generating Station regarding its source waterbody (Southern California Bight), the design 

and operation of the facility, and previous biological studies at the station and in the source 

waterbody. 

2.1 SOURCE WATERBODY 

The San Onofre Nuclear Generating Station is located on the Southern California coastline 

between San Clemente and Oceanside, CA (Figure 2-1). The station is located south of 

Point Conception in the Southern California Bight. The coastal waters are influenced by a 

variety of oceanographic, biological, and meteorological components. Movements of the 

source water body are greatly affected by winds, tides, and currents. 

The climate of southern California is Mediterranean with short, mild winters and warm, dry 

summers. Annual rainfall amounts average 46 cm, with most precipitation falling between 

November and April. The summer winds are characterized by sea breezes which combine 

with prevailing northwesterly winds to produced strong onshore winds. Southeast coastal 

winds are produced during late fall and winter. 

There are two major oceanic currents that affect the Station: the California Current and the 

Davidson Current. The California Current flows southward along the California coastline to 

a point south of Tanner and Cortes Banks in which the current begins to flow easterly 

toward land and then turns into a northward flowing current known as the Southern 

California Countercurrent. The surface water circulation in the region is driven by a complex 

combination of predominant southerly flow, a northerly flowing countercurrent, coastal 

geometry, and bottom topography. 

Coastal upwelling occurs when strong westerly or northwesterly winds driven by storms or 

pressure systems begin blowing and cause coastal water to move offshore which forces 

cooler water to rise from the bottom. Although occurrences have been infrequent, short 

periods of upwelling have been observed at SONGS as a result of strong west-northwest 

winds (SCE 1983). 

2.2 INTAKE DESIGN AND OPERATION 

SONGS consists of three units with a current, combined rated capacity of 2,174 MWe-net. 

Unit 1 began commercial operation in 1968 and stopped generating electricity in 1992. Unit 

1 was a baseload plant and had an operating capacity of 436 MW. Unit 2 began low-power 

testing in 1982 and Unit 3 began start-up testing in 1982. Unit 2 became commercially 

operational in 1983, while Unit 3 became commercially operational in 1984. Units 2 and 3 

each have an operating capacity of 1,087 MW. Units 2 and 3 utilize once-through cooling 

with a total design intake capacity of 2,390 MGD. The units generate power using 

pressurized water nuclear reactors. The reactors boil freshwater contained in a closed loop 

system with the resulting steam driving turbines which are then cooled in condensers by 

seawater. Seawater is brought into the condenser through a single intake, heat is absorbed, 

and the seawater is discharged into the ocean. 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A2-2 Background Information 

Units 2 and 3 each have a single offshore intake which extends 970.2 meters (3,183 feet) 

from shore and is set in water 9.8 meters (32 feet) deep. Each intake is equipped with a 

velocity cap which extends 5.5 meters (18 feet) above the ocean bottom. Each Unit has 

four circulating water pumps which bring cooling water to the plant, even when a Unit is not 

producing power. The pumps are shut down during scheduled maintenance when the 

cooling water system is dewatered (approximately every 18 months), and may be shut down 

for unscheduled maintenance activities. Debris and entrapped organisms are removed from 

the screenwells via bar racks and 3/8-inch mesh traveling screens. The trash bars have one 

inch opening and are operated using a drive mechanism to periodically remove coarse 

debris. The trash bars and traveling screens (7 at each unit) are angled to the inlet flow so 

as to guide fish to elevator baskets, which then return the fish to the ocean through a 

submerged fish return conduit. 

A “heat treatment” procedure is used to control biofouling by mussels and barnacles at 

SONGS. During this procedure, two thirds of the normal discharge is diverted back through 

the condenser to heat the water in the screenwell to 105oF. Water flow through the intake 

and discharge conduits are “swapped” by opening and closing valves in such a way that 

water temporarily enters through the discharge ports and discharges through the intake 

structure. In this way the intake conduit and velocity cap are treated with water up to 

125° F. 

2.3 HISTORICAL DATA 

Southern California Edison conducted studies to assess entrainment and to evaluate the 

fish return system from 1978 through 1986. The Unit 1 §316(b) demonstration study report 

was submitted to the RWQCB in 1982 and demonstration study reports were submitted for 

Units 2 and 3 in 1988 (SCE 1998). Impingement studies have been conducted at SONGS 

Units 2 and 3 since 1983. Entrainment monitoring was conducted at SONGS Unit 1 in 1979 

and 1980. Extensive studies were conducted to determine entrainment impacts at Units 2 

and 3 from 1979 (preoperational period) through 1986. These studies used near-field 

sampling, rather than in-plant sampling, to estimate entrainment losses. These studies are 

available as a source of information for predicting the current levels of impingement and 

entrainment at SONGS and the fish species that would be involved. 

2.3.1 Impingement Studies 

Impingement sampling was conducted at SONGS weekly from 1983 to 1994, monthly from 

1994 to 1998, and quarterly since 1999. 

Fish enter the Station via an offshore cooling water intake which guides fish through the 

screenwell to the fish return system. Those specimens which do not enter the fish return 

system are impinged on traveling screens and are then collected in containers. 

Impingement sampling at SONGS was conducted once per quarter in 2003 (Jan-Mar; AprJun; Jul-Sep; Oct-Dec). Prior to the 24-hour sampling period, all screens were run and 

cleared of all marine life and debris. Over the following 24 hours, screens were run as 

required for normal plant operation, however all marine life and debris was collected in large 

containers. At the end of the 24-hour period all screens were run a final time and any 

additional marine life and debris was added to the collection. Impinged fish were then 

separated from the debris, sorted by species, weighed, measured and examined for gender 

and evidence of disease. 
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Fish loss during heat treatments was also monitored and added to estimated total 

impingement losses. Fish which do not move into the fish return system during fish chase 

procedures, are killed by the elevated temperatures. Dead fish are removed on screens and 

are identified and sorted by species, counted, weighed, and sub-samples are measured and 

sexed. 

Combined fish impingement at SONGS Units 2 and 3 from 1983 through 2003 has ranged 

from 3,672 kilograms in 1983 to 42,612 kilograms in 1995 (Figure 2-1). Species 

composition has been relatively consistent over the years and is represented by the 2003 

survey. 

The 2003 monitoring estimated annual impingement for Unit 2 was 995,396 fish 

representing 62 species (Table 2-1) (SCE 2003). Estimates were based on four quarterly 

impingement samples and nine heat treatment samples. Northern anchovy (Engraulis 

mordax) and queenfish (Seriphus politus) were the most abundant species representing 

over 88 and 8 percent of the total specimens collected, respectively. In addition, northern 

anchovy represented 61 percent of the total weight, while queenfish represented 19 percent 

of the total biomass. 

The annual impingement for Unit 3 was considerably higher than Unit 2 in 2003, as an 

estimated 2,569,037 fish representing 60 species were impinged (Table 2-1) (SCE 2003). 

Northern anchovy was the most abundant species impinged, representing almost 89 percent 

of the total impingement and almost 61 percent of the biomass. Similar to Unit 2, queenfish 

were second in abundance, representing over 7 percent of the total collection and almost 18 

percent of the total biomass. 

Overall, SONGS impinged an estimated 3,564,433 fish in 2003 (Table 2-1). Northern 

anchovy and queenfish comprised 88 and 7 percent of the total 2003 impingement. Peak 

impingement occurred in July, August, and September mainly as a result of an increase in 

catch of northern anchovy (Table 2-2). Impingement counts also increased for queenfish, 

Pacific sardine (Sardinops sagax), and Pacific pompano (Peprillus simillimus) during this 

period. Overall, impingement totals during the July through September period accounted for 

more than 86 percent of the total yearly impingement at the Station. 

Northern anchovy and queenfish have consistently made up the majority of fish numbers at 

SONGS, but in recent years Pacific sardines have become increasingly prevalent. 

2.3.2 Entrainment Studies 

Table 2-3 summarizes plankton studies completed at SONGS. 

SCE conducted entrainment monitoring at SONGS Unit 1 from August 1979 through July 

1980. Sampling was conducted monthly at the Unit 1 intake riser. Samples were pumped 

from within the offshore intake riser of the CWIS. Four replicate samples were collected 

during each of six periods over 24 hours. 

Northern anchovy were the most commonly collected species, as they comprised 45.2% of 

the total entrainment in 1979-1980 (Table 2-4) (SCE 1983). Queenfish and white croaker 

(Genyonemus lineatus) were also abundant in entrainment samples, comprising 10.4 and 

10.1 percent of the total respectively. Other species identified as target species were 

infrequently collected, as these species comprised only 1.9% of the total entrainment. 
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Peak entrainment occurred in spring from March through May and again in fall from 

September through October (Table 2-5). The largest number of northern anchovy (33.94 x 

10P

6

P

) and white croaker (7.44 x 10P

6

P

) were entrained in March, while queenfish were most 

abundant in May (8.78 x 10P

6

P

). Several croaker species were listed as target species, 

including spotfin croaker (Roncador stearnsii), which was collected primarily in the month of 

September (2.04 x 10P

6

P

), black croaker (Cheilotrema saturnum), which were most abundant 

in summer months, and yellowfin croaker (Umbrina roncador), which were not collected in 

the 1979-1980 surveys. Several nontarget species were also occasionally collected in high 

numbers, including cheekspot goby (Ilypnus gilberti) in October (4.64 x 10P

6

P

), bay goby 

(Lepidogobius lepidus) in January (6.15 x 10P

6

P

), and California corbina (Menticirrhus 

undulatus) in September (3.10 x 10P

6

P

). 

Extensive studies were conducted at SONGS by the Marine Review Committee (MRC) at 

the request of the California Coastal Commission (CCC). These studies included sampling 

designed to estimate losses due to entrainment at Units 2 and 3. (MRC 1989). Rather than 

directly measuring entrainment at the intake, these studies used a Before-After-ControlImpact (BACI) analysis to determine impacts on plankton by the SONGS intakes. 

It was concluded that the effects detected were of relatively minor importance during the 

1983-1986 monitoring period for the following reasons: (1) no general large-scale reduction 

of plankton abundance was detected; (2) although there were suggestions of relatively 

uniform patterns of change within some subsets of the ichthyoplankton and 

macrozooplankton, there was no evidence of an overall uniform pattern of change in the 

plankton community; (3) in many cases where significant changes were detected, plausible 

alternative explanations for those changes could be postulated; and (4) for the 

ichthyoplankton, significant test results tended to reflect changes in the more numerous 

younger larvae, which are less important than the older larvae in terms of adult equivalents 

(MEC 1987). 

2.3.3 Fish Return System Studies 

SONGS utilizes a fish return system (FRS) which is normally operated to return 

accumulated fish to the ocean at least twice a day by station operators. The system uses a 

series of vanes and louvers to create a pressure differential and velocity changes which are 

detected by fish, causing them to swim along the louvers and into a quiet bypass area 

(Schuler and Larson 1975). The bypass area measures 4.9 x 4 m and is equipped with a 

watertight elevator basket. Fish congregating in the bypass area are transported via an 

elevator basket to a sluiceway which returns the fish back to the ocean. 

Studies of the FRS were conducted from 1984 through 1994 and again in 1999. These 

studies were conducted at SONGS to evaluate the diversion effectiveness of the fish return 

system and the survival of fish following transport through the return system to the 

waterbody (SCE 1988; Love et al. 1989; SCE 2003). The fish returned back to the ocean 

were identified and counted as they were lifted in the elevator basket. Biomass and 

numbers of species too numerous to make visual counts were estimated by sub-sampling 

the elevator with nets. Efficiency ratings were estimated from these studies based on the 

number of fish returned to the ocean alive compared to the number of fish impinged during 

normal operation. These ratings are a measure of the reduction in impingement mortality 

achieved by the FRS. Overall efficiency ratings across all species have varied among study 

years and between units, with the highest rating of 96.5% for Unit 2 in 1984 and a low of 

36.6% for Unit 3 in 1990. The 1999 results indicate 72 percent efficiency for Unit 2 and 68 
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percent for Unit 3 (SCE 2003). The efficiency of the fish return system likely depends both 

on environmental and water quality conditions, and on species specific survival and 

behavior. 

Return rates for the most abundant species, northern anchovy and queenfish, were high 

with 99.3 and 87.7 percent efficiency, respectively (Love et al. 1989). In addition, the 

system was efficient for strong swimming species and many commercially and sport 

important species such as jacksmelt (Atherinopsis californiensis), salema (Xenistius 

californiensis), topsmelt (Atherinops affinis), kelp bass (Paralabrax clathratus), yellowfin 

croaker, California corbina (Menticirrhus undulatus), and California halibut (Paralichthys 

californicus). The system was not as effective in diverting weak swimming species such as 

plainfin midshipman (Porichthys notatus), pipefish (Syngnathus spp.), and giant kelpfish 

(Heterostichus rostratus). 

Survival studies were conducted in 1984 and 1985 to evaluate fish survival following 

passage through the fish return system. Ninety-six hour in-situ survivorship studies were 

conducted by holding fish in holding nets at the end of the return system. Survival rates for 

most species were high (>90 percent), with northern anchovy, salema, and yellowfin croaker 

exhibiting very little mortality (Love et al. 1989). Survival of queenfish was not as favorable, 

as 31.6 and 54.1 percent of the specimens survived the 96-hour holding experiments for 

Units 2 and 3 respectively. In addition, survival of white croaker was 49.5 percent and 25 

percent at Units 2 and 3, respectively, and no slough anchovies (Anchoa delicatissima) 

survived the experiment. 

Uncertainty in the estimates of FRS efficiencies was high for smaller size categories of fish 

(e.g., less than about 50 mm) in the prior studies since the sampling design did not attempt 

to account for very small or larval fish that are assumed to pass through the station 

(entrained). That is, the ratio of fish returned to fish impinged may have underestimated 

FRS efficiency in returning small juvenile and larval fish that passed through sampling nets. 

Return of larvae and entrainable-sized juveniles by the FRS has been qualitatively observed 

in these prior studies. Therefore, the FRS undoubtedly has some, as yet unquantified, 

effectiveness for reducing entrainment, as well as impingement, relative to intake systems 

without this fish protection technology. 

2.3.4 Fish Chase Operations 

Prior to heat treatments, a fish chase procedure is used to guide fish out of the circulating 

water system and into the fish return system. The fish chase procedure is used to minimize 

mortality to fish residing in the circulating water system intake or screenwell areas, which 

would otherwise die during heat treatments. 

Many fish will reside in the habitats created around the gate slots and other structures of the 

cooling water system. These fish are guided toward the fish return by manipulating crossover gates in the screenwell which slowly warms the water and creates eddy currents to 

dislodge fish residing in low flow habitats. A target temperature of 83oF is typically used 

during fish chase operations, however higher temperatures are sometimes needed to 

dislodge warm water species such as yellowfin croaker, sargo (Anisotremus davidsonii), and 

zebra perch (Hermosilla azurea) (SCE 2003). The process dislodges the fish and causes 

them to move toward the fish return system. The operation is monitored by fisheries 

biologists to ensure fish are not being overly stressed. The number of fish impinged during 

heat treatment operations and the number of fish released back to the ocean during fish 
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chase procedures is recorded along with data on fish condition, species composition, 

operational status, and water temperatures. 

Overall in 2003, fish chase operations successfully released over 46% of all fish by number 

and over 56% of the biomass of fish that would have otherwise been killed during the heat 

treatment (SCE 2003). A total of 9 fish chase operations were performed for Unit 2 and 7 

for Unit 3 which resulted in the release of 25,633 and 50,312 fish back into the ocean, 

respectively. Fish were released in good condition, as maximum water temperatures ranged 

from 80 to 87oF and biologists monitoring the procedure terminated the temperature rise 

when indications of fish stress were observed. 

Analysis of commonly impinged species revealed limited effectiveness of fish chase 

procedures for several species. Queenfish, the second most frequently impinged species 

exhibited a 23 percent release as a result of fish chase operations, and several species 

including shiner perch (Cymatogaster aggregata) and deep body anchovy (Anchoa 

compressa) exhibited a zero percent return. Fish chase operations were 53 percent 

effective in returning northern anchovy, the most frequently impinged species, back to the 

ocean prior to heat treatments. 

2.3.5 Velocity Cap 

SONGS utilizes an intake velocity cap on both Units 2 and 3 intakes as a means of reducing 

fish entrapment. The effectiveness of a velocity cap is dependent on the ability of species to 

avoid the horizontal flow created by a velocity cap. Early studies on the effectiveness of 

velocity caps indicated a 95% reduction in annual fish entrapment at the El Segundo 

Generating Station in 1956 and 1957 (Weight 1958). However, fish entrapment is 

potentially density-dependent, which was an aspect not considered in the Weight study. 

Laboratory studies indicate 85 to 90 percent reductions in anchovy entrapment may be 

expected using a velocity cap (Schuler and Larson 1975). 

Velocity cap studies performed at Ormond Beach Generating Station (OBGS) and 

Huntington Beach Generating Station (HBGS) in 1979 and 1980 indicated an overall 

reduction in fish entrapment as a result of a velocity cap, with generally higher effectiveness 

during daylight hours (Thomas et al. 1980a). Entrapment rates for queenfish were higher 

from samples collected with a velocity cap during night sampling at HBGS (1979) and OBGS 

(1980). The velocity cap was effective in reducing entrapment of northern anchovy, the 

most frequently impinged species at SONGS, in the studies conducted at HBGS in 1979 

and 1980. In addition, laboratory studies indicate anchovy were better adapted to resist the 

horizontal flow of a velocity cap than the vertical downward flow of an uncapped intake 

(Schuler and Larson 1975). 

The use of velocity caps as a technology for reducing impingement is widely accepted. 

Although it is impractical to perform site-specific studies at SONGS that would provide 

additional estimates of velocity cap effectiveness, substantial information is available from 

laboratory design studies and prior field studies elsewhere. These data can be used to 

estimate a reasonable range of effectiveness of the SONGS velocity cap for reducing 

impingement to be incorporated into baseline impingement estimates. Possible day-night 

differences in velocity cap efficiencies have been suggested in the literature, but it is unclear 

whether measured differences in entrapment are caused by diel changes in fish densities 

near the intakes or changes in velocity cap effectiveness, or both. 
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2.4 Sufficiency of Existing Information for IM&E Characterization Study 

As described in Section 1.2, the IM&E Characterization Study requires biological data on the 

following: 

1. Identification of fish and shellfish life stages and species in the vicinity of the 

CWIS and susceptible to impingement and entrainment; 

2. Their abundance and spatial/temporal distribution, sufficient to characterize the 

annual, seasonal and diel variations in impingement mortality and entrainment; 

and 

3. Documentation of current impingement mortality and entrainment of these species 

and life stages. 

USEPA criteria for using historical data are that the data must: (1) reflect current conditions 

and, (2) have been collected using appropriate QA/QC measures. 

As discussed above and in Section 3, there is information currently available on the fish 

community in the vicinity of the SONGS that might satisfy the first two requirements. 

However, there are no current data on entrainment at SONGS, since the most recent 

monitoring studies were conducted over 19 years ago. In addition, sampling frequent 

enough to account for short-term temporal variations in impingement has not been 

conducted since quarterly monitoring began in 1999. 

In terms of the fish community and its relationship to impingement and entrainment at 

SONGS (the first two items above), sustained trends in annual abundance resulting from 

changes in predominant currents and climate trends such as El Niño may cause some 

species or life stages to become more or less abundant in the vicinity of the intake. 

The third item listed above as information required for the IM&E Characterization Study, i.e., 

documentation of current impingement mortality and entrainment, would not be satisfied by 

using available data. Therefore, the remaining sections of this sampling plan are devoted to 

describing the aquatic habitat and fish community for the purpose of a preliminary selection 

of representative species, and outlining a recommended sampling scope for monitoring 

impingement and entrainment. 
Copyrighted page/s removed. Copyrighted 

material is not available in Regulations.gov since 

it may not be reproduced without consent of the 

copyright holder. 

Please contact the EPA Docket Center, Public 

Reading Room to view this document. 

Address: 1301 Constitution Ave, NW 

Room 3334 

Washington, DC 20004 

Telephone: 202-566-1744 

Fax: 202-566-9744 

Email: docket-customerservice@epa.gov
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Figure 2-2. Aerial view of San Onofre Nuclear Generating Station. 
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ASA ANALYSIS & COMMUNICATION, INC. A2-10 

 SONGS Impingement 1983-2003

0

5000

1000015000200002500030000350004000045000

1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 20

Year

Kilograms

Unit 3Unit 2

Figure 2-3. SONGS Impingement 1983-2003. 
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Table 2-1 Estimated Number of Fish Impinged at San Onofre Nuclear Generating Station, 2003 

Common Name 

Unit 2 

Abundance

Unit 3 

Abundance

Total 

Impingement

% of 

Total 

Biomass 

(kg) 

Northern Anchovy 883,575 2,281,516 3,165,091 88.80% 13,347.78

Queenfish 81,746 191,879 273,625 7.68% 3,999.22 

Pacific Sardine 12,742 50,597 63,339 1.78% 2,328.69 

Pacific Pompano 4,419 22,162 26,581 0.75% 566.00 

Jacksmelt 2,077 5,672 7,749 0.22% 341.62 

White Seaperch 372 3,624 3,996 0.11% 27.62 

Walleye Surfperch 1,551 1,877 3,428 0.10% 48.07 

Shiner Perch 1,401 1,836 3,237 0.09% 22.62 

White Croaker 727 2,026 2,753 0.08% 57.62 

Bocaccio 762 1,661 2,423 0.07% 7.78 

Jack Mackerel 830 492 1,322 0.04% 66.27 

Salema 1,004 266 1,270 0.04% 77.38 

Sargo 326 864 1,190 0.03% 324.59 

Yellowfin Croaker 526 416 942 0.03% 233.60 

Specklefin Midshipman 73 823 896 0.03% 100.12 

Black Perch 199 607 806 0.02% 11.37 

California Grunion 372 369 741 0.02% 11.97 

Topsmelt 603 119 722 0.02% 34.20 

Cabezon 480 158 638 0.02% 5.77 

Deep Body Anchovy 56 488 544 0.02% 6.06 

Others 1,555 1,585 3,140 0.09% 304.65 

Impingement Totals 995,396 2,569,037 3,564,433 100.00% 21,922.98
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ASA ANALYSIS & COMMUNICATION, INC. A2-12 

Table 2-2 Estimated Monthly Impingement Based on Quarterly Sampling at San Onofre Nuclear Generating Station, 20

Common Name Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov 

Northern Anchovy 4,403 8,845 15,166 57,568 61,618 62,747 1,104,021 1,106,421 708,691 23,193 8,284 

Queenfish 7,507 16,571 27,937 5,274 6,425 6,639 32,110 33,264 20,751 24,557 44,62

Pacific Sardine 1,729 3,616 5,962 153 156 171 14,385 14,390 11,932 5,379 2,678 

Pacific Pompano 4 - 57 2 6 4 9,462 9,463 7,538 24 16 

Jacksmelt 786 475 1,189 704 223 194 183 125 49 1,016 1,431 

White Seaperch 6 - 6 1,232 1,298 1,261 58 55 67 9 2 

Walleye Surfperch 59 - 16 706 716 748 380 324 298 20 48 

Shiner Perch 42 - 5 543 660 611 500 463 104 151 129 

White Croaker 40 56 111 327 374 383 339 604 347 50 51 

Bocaccio - - - 780 806 789 30 12 6 - - 

Jack Mackerel 95 56 70 2 1 6 131 126 160 89 350 

Salema 31 - 2 5 5 33 41 116 302 558 79 

Sargo 2 - 2 - - 89 241 648 154 42 10 

Yellowfin Croaker 8 - 4 4 - 45 119 166 167 361 68 

Specklefin Midshipman 20 56 93 90 93 94 158 159 127 3 3 

Black Perch - - 6 212 262 267 17 6 22 12 2 

California Grunion 63 56 62 150 161 153 - - 1 31 33 

Topsmelt 53 - 1 - - 83 164 126 31 64 164 

Cabezon - - 1 153 193 261 20 5 3 1 - 

Deep Body Anchovy 55 93 156 - - - - - - 35 105 

Others 120 93 192 230 295 405 344 331 288 137 397 

Total 15,023 29,917 51,038 68,135 73,292 74,983 1,162,703 1,166,804 751,038 55,732 58,47
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Table 2-3 Historical Summary of Plankton Studies at SONGS 

STUDY Date Description Frequency 

SONGS Unit 1 316(b) 

entrainment studies 

8/79-

7/80 

Pumped from intake Monthly; 6 samples, 4 reps 

each; over 24-hr period 

SONGS 2&3 PreOperational 8/79-

11/81 

Manta, bongo and 

Auriga nets; 

400 m3; As close as 

possible to intakes and 

at Control 

Approx. weekly during peak 

months. 

38 sample days 

SONGS 2&3 Interim 

Period 

3/82-

6/83 

Manta, bongo and 

Auriga nets; 

400 m3; As close as 

possible to intakes and 

at Control 

Monthly during peak 

months. 

5 sample days 

SONGS 2&3 

Operational Period 

7/83-

9/86 

Manta, bongo and 

Auriga nets; 

400 m3; As close as 

possible to intakes and 

at Control 

Monthly during peak 

months. 

27 sample days. 

SONGS 2&3 Intake 

Loss Surveys 

10/85-

1/86 

Manta, bongo and 

Auriga nets; 

400 m3; As close as 

possible to intakes and 

at Control 

Tri-weekly; 6 survey days 
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Table 2-4 Estimated Number of Fish Collected in Entrainment Samples at San Onofre Nuclear 

Generating Station, 1979-1980. Estimated Daily Entrainment (No. x 10P

6

P

) (SCE 1983) 

Common Name Daily Entrainment % of Total 

Northern Anchovy 6.5 45.2% 

White Croaker 1.46 10.1% 

Queenfish 1.5 10.4% 

Pacific Butterfish 0.01 0.1% 

Kelp Bass 0.05 0.3% 

Barred Sand Bass <0.01 <0.1 

Sargo 0.01 0.1% 

Spotfin Croaker 0.17 1.2% 

Bocaccio - - 

Black Croaker 0.02 0.1% 

Yellowfin Croaker - - 

Cheekspot Goby 0.77 5.4% 

Bay Goby 0.61 4.2% 

Blenny 0.58 4.0% 

California Corbina 0.33 2.3% 

Kelpfish 0.23 1.6% 

Unidentified Larvae 1.17 8.1% 

Others 0.97 6.7% 

Totals 14.38 100.0% 
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ASA ANALYSIS & COMMUNICATION, INC. A2-15 

Table 2-5 Estimated Fish Entrainment At San Onofre Nuclear Generating Station, 1979-1980. Daily Entrainment (N

Monthly Samples (SCE 1983) 

Common Name Aug Sep Oct Nov Dec Jan Feb Mar Apr May 

Northern Anchovy 2.30 5.00 5.53 0.09 0.81 1.20 4.49 33.94 14.14 9.64 

White Croaker 0.05 0.06 0.12 - 2.33 0.67 1.46 7.44 2.85 2.28 

Queenfish 0.65 0.96 0.12 - - - - 1.37 4.70 8.78 

Pacific Butterfish - - - - - - - 0.07 0.04 - 

Kelp Bass 0.28 0.17 0.09 - - - - 0.01 - - 

Barred Sand 

Bass - <0.01 - - - - - - - - 

Sargo 0.08 0.01 - - - - - - - - 

Spotfin Croaker - 2.04 - - - - - - - - 

Bocaccio - - - - - - - - - - 

Black Croaker 0.04 0.07 - - - - - 0.02 0.01 0.05 

Yellowfin Croaker - - - - - - - - - - 

Cheekspot Goby 0.07 0.92 4.64 0.02 0.05 2.64 0.36 0.05 0.19 0.12 

Bay Goby 0.02 0.07 0.09 - 0.03 6.15 0.67 0.14 0.01 0.04 

Blenny 1.94 0.81 0.15 0.05 0.05 0.02 0.01 0.07 0.14 1.16 

California Corbina 0.85 3.10 - - - - - - - - 

Kelpfish 0.06 0.26 0.50 0.01 0.57 0.63 0.52 0.01 0.04 0.10 

Unidentified 

Larvae 1.70 2.77 0.35 0.03 0.43 0.40 3.86 3.27 0.53 0.68 

Others 1.46 2.87 0.84 0.10 0.34 2.35 1.05 0.47 0.97 0.29 

Totals 9.50 19.11 12.43 0.30 4.61 14.06 12.42 46.86 23.62 23.14 
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ASA ANALYSIS & COMMUNICATION, INC. A3-1 Fish Community 

3. FISH COMMUNITY 

This section describes the aquatic habitat and the fish community in the vicinity of the San 

Onofre Nuclear Generating Station and proposes representative species for detailed study. 

3.1 AQUATIC HABITAT 

SONGS withdraws its cooling water from the Southern California Bight, an open embayment 

of the Pacific Ocean that extends from Point Conception, California to the north, southward 

to Cabo Colnett, Baja California. The water in the vicinity of SONGS is dominated by the 

California Current that flows southeast along the coast and changes to a Southern California 

counter currents which sometimes exhibits upwelling. The temperature of the water follows 

a normal seasonal cycle with a summer high water temperature around 68P

°

P

F in August and 

a winter low water temperature around 57P

°

P

F (SAIC 1994). There can be some changes to 

the normal seasonal cycles from upwelling of colder waters in localized events. This 

generally happens when winds cause surface currents that flow offshore and result in a 

breakdown of thermal stratification bringing the colder water to surface. 

The nearshore oceanic habitats in the vicinity of the Station may be divided into intertidal 

habitat, subtidal habitat and kelp beds for purposes of discussion. 

3.1.1 Intertidal 

The wave-swept, sandy beaches in the vicinity of the plant provide one of the most hostile of 

marine environments being subject to intense wave-induced energies, exposure to air and 

sun during low tides, and the constant reworking and major seasonal movements of the 

substrate. In addition, periodic beach replenishment activities can lead to burial of existing 

habitats. As a result, these habitats have a relatively sparse and patchily-distributed aquatic 

community. Typical year-round inhabitants include the air-breathing pill bug (Alloniscus 

perconvexus), an isopod (Tylos punctatus), the beach hopper (Orchestoidea californiana), 

the mole crab (Emerita analoga), an opossum shrimp (Archaemysis maculata), polychaete 

worm (Euzonus mucronata), the bean clam (Donax gouldi), and the Pismo clam (Tivela 

stultorum). In addition, California grunion (Leuesthes tenuis) utilize the beach areas as 

spawning habitat during the warmer part of the year. 

3.1.2 Subtidal Sand 

The majority of habitat in the vicinity of SONGS is comprised of soft subtidal sediments 

(coarse to fine sand) with few hard substrates. The shallow nearshore benthic environment 

is subject to frequent disturbance due to wave action. The frequency of this disturbance 

declines further offshore as the water deepens. In addition, seasonal movement of beach 

sand inshore during summer months and offshore during the winter can result in burial of 

existing habitat and associated fauna. The unstable nature of this habitat leads to a 

heterogeneous assemblage of organisms, both spatially and temporally, which occupy this 

type of habitat. 

Common benthic macroinvertebrate species which are found in this habitat include the 

polychaete worm (Apoprionospio pygmaeus), the proboscis worm (Carinoma mutabilis), a 
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ASA ANALYSIS & COMMUNICATION, INC. A3-2 Fish Community 

sea spider (Callipallene californiensis), and crustaceans such as Megaluropus sp. and 

Leptocuma forsmani. Overall, poychaete worms are the most abundant and common group 

in this habitat, followed by amphipods and other arthropods. Fish which can be common on 

this habitat include flatfish, such as the speckled sanddab (Citharichthys stigmaeus), the 

hornyhead turbot (Pleuronichthys verticalis), and the California halibut (Paralichthys 

californicus). In the water above this habitat, various planktonic invertebrates, such as the 

calanoid copepod, Acartia tonsa, and pelagic fishes, such as the northern anchovy 

(Engraulis mordax), the deepbody anchovy (Anchoa compressa), and the topsmelt 

(Atherinops affinis), can all be common. 

3.1.3 Kelp Beds 

The kelp beds are one of the most conspicuous habitats visible along the southern coast of 

California. These kelp beds form in areas were suitable rocky substrate is available in the 

appropriate depths of water. In the vicinity of SONGS there are three recognized distinct 

kelp stands. The nearest bed is the San Onofre Kelp Bed (SOK) which is about 0.5 km 

south of the Units 2 and 3 discharge diffusers. The second is the San Mateo Kelp Bed 

(SMK) which is about 4.5 km north and the farthest is the Barn Kelp Bed (BK). The area 

extent of each of these kelp stands varies both seasonally with normal growth patterns of 

the kelp and across the years as a result of varying meteorological conditions and the 

amount of rock substrate exposed from the sand bottom. 

These kelp beds consist of dense stands of giant kelp (Macrocystis pyrifera) and related 

algae which serve as habitat for a variety of plant and animal species. Mature giant kelp 

plants can reach a length of 50-150 ft extending upwards from a root-like holdfast which 

attaches the plant to the rocky substrate. Many of the individual plants often grow together 

forming an underwater “forest” which is the kelp bed. Each plant consists of one or more 

fronds which form a dense canopy that can shade the entire bed. Beneath the giant kelp 

canopy resides an understory of smaller macroalgal species such as Eisenia aborea, 

Egregia laevigata, Laminaria farlowii, and Cystoseira osmundacea. The density of this 

subcanopy component also varies both seasonally and across the years along with the giant 

kelp. Finally, nearest to the substrate is a turf component consisting of a variety of smaller 

red and brown algae such as Rhodymenia californica. 

The combination of the three components of the vegetative community, together with the 

rocky substrate, provide habitat for a variety of invertebrate and vertebrate species. 

Common invertebrates within the turf component include a sea fan (Muricea californica), 

tubeworms (e.g., Diopatra ornata), tunicates (e.g., Styela montereyensis), and whelks (e.g., 

Kelletia kelletii), along with a variety of smaller species (bryozoans, sponges, tunicates, 

hydrozoans, etc.). Invertebrate species of commercial and recreational value that utilize 

kelp bed habitat include, abalone, sea urchins, and spiny lobster. The kelp beds also serve 

as important habitat for a variety of fish species. Common fish inhabitants include the kelp 

bass (Paralabrax clathratus), the barred sand bass (Paralabrax nebulifer), the black perch 

(Embiotoca jacksoni), the kelp surfperch (Brachyistius frenatus), the white seaperch 

(Phanerodon furcatus), and the California sheephead (Semicossyphus pulcher). Much of 

the recreational fishing in the nearshore waters occurs in and immediately adjacent to kelp 

beds similar to those described herein. 
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3.2 COMMUNITY COMPOSITION 

The fish community in the vicinity of the SONGS intake can be characterized from a number 

of fish surveys that were conducted both before and after Units 2 and 3 began operation in 

the early 1980’s, as well as from impingement sampling at the SONGS intake. These 

surveys cumulatively have documented the occurrence of at least 40 kelp related species, 

66 pelagic or midwater species (live in the water column), and 68 benthic species (live on or 

near sandy bottom) (MRC 1989). The majority of the kelp-related species are also 

associated with reefs in general. 

Of the 10 most common pelagic species, only the northern anchovy is a major commercial 

resource. Pacific mackerel, Pacific barracuda and the white croaker are sport fish (MRC 

1989). Most of the abundant pelagic fish are typically small schooling species that are 

important as food for larger sport and commercial species. The most abundant species of 

midwater fish are northern anchovy, young queenfish, young white croaker, and three 

species of silversides. Queenfish and white croaker are common at all depths in the 

nearshore water column. However, larger pelagic predatory fish, such as Pacific mackerel 

and jack mackerel, become relatively common only in the deeper water. 

Bottom fish in the vicinity of SONGS include the larger bottom-oriented individuals of white 

croaker and queenfish, as well as species with sport or commercial value such as longfin 

sanddab, speckled sanddab, hornyhead turbot and halibut (MRC 1989). 

As a result of habitat preferences, ability to avoid the cooling water intake, other life history 

characteristics, and the design of the SONGS intake, only a fraction of the species 

comprising the community of the Southern California Bight in the SONGS’ vicinity is 

susceptible to impingement and entrainment. Northern anchovy and queenfish are by far 

the most abundant species impinged at SONGS. For example, these two species 

comprised over 96 percent of the 60 species of fish impinged at SONGS during 2003 (Table 

2-1). Most species were impinged in low numbers—four species accounting for more than 

99 percent of the fish impinged. Entrainment sampling at Unit 1 during 1979-80 indicated 

that Northern anchovy, together with queenfish and white croaker, comprised about 66 

percent of total fish entrained at SONGS, and a total of 15 species accounted for at least 85 

percent of the fish entrained. 

3.2.1 Protected Species 

Federally protected fish and shellfish species that may occur near SONGS include the 

Southern California steelhead (Onchorhynchus mykiss), tidewater goby (Eucyclogobius 

newberryi), and white abalone (Haliotis sorenseni). California state protected species that 

may occur near SONGS include giant sea bass (Sterolepis gigas), broomtail grouper 

(Mycteroperca xenarcha), gulf grouper (Mycteroperca jordani) and garibaldi (Hypsypops 

rubicundus). There are also several species that are not protected but are of special 

concern including cabezon (Scorpaenichthys marmoratus) and bocaccio (Sebastes 

paucispinis) (SCE 2003). 

 Protected fish species are infrequently impinged at SONGS. For example, no protected 

fish species were collected in impingement monitoring during 2003, although a total of 15 

giant sea bass were entrapped and returned to the ocean by the FRS. Two species 

categorized by the State as of special concern, cabezon and bocaccio, are impinged in low 

numbers at SONGS (e.g., Table 2-1). 
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Of the federally protected species, the tidewater goby, Southern California steelhead, and 

white abalone have never been observed near SONGS. The tidewater goby is normally 

found in brackish water of streams but may come into coastal water after heavy rain (SCE 

2004). The Southern California steelhead is thought to be in San Mateo Creek which is just 

north of SONGS (SCE 2004). White abalone adults live on the bottom and in kelp beds and 

reefs in deep waters and thus are not generally vulnerable to impingement at the SONGS 

intake, although as larvae they may be entrained (SCE 2004). 

3.3 REPRESENTATIVE INDICATOR SPECIES 

Proposed additional entrainment and impingement monitoring (Sections 4 and 5) will identify 

all fish and selected important shellfish to the lowest practical taxonomic level. However, for 

several reasons it is beneficial to focus the proposed FRS studies and subsequent 

assessments of compliance on a subset of representative species. The following are 

proposed as representative indicator species for the SONGS compliance assessment: 

Common Name Scientific Name 

Northern anchovy Engraulis mordax 

Queenfish Seriphus politus 

White croaker Genyonemus lineatus 

Pacific sardine Sardinops sagax 

Kelp/Sand Bass Paralabrax spp. 

Spiny Lobster Panulirus interruptus 

These species account for approximately 98% of impinged fish and 84% of historical 

entrainment, are representative of a range of FRS effectiveness observed in prior studies, 

include both pelagic and bottom oriented species, and have available life history information 

needed for calculating Lost Yield and Production Foregone. These are two measures of 

equivalent loss that are useful for expressing entrainment and impingement reductions on 

an equivalent basis and essential for estimating economic benefits from existing or 

proposed fish protection measures. At present, few, if any, of the other species occurring in 

impingement and entrainment at SONGS have well described age and growth 

characteristics adequate for equivalent loss estimates 

3.3.1 Northern Anchovy 

Northern anchovy is one of four species of Engraulidae (anchovies) reported from the 

California coast. The northern anchovy is an important commercial species and one of the 

more abundant fish occurring near SONGS. Northern anchovy are harvested for human 

consumption, live or dead bait, and other commercial uses, and have become especially 

important to commercial fisheries with the decline of the Pacific sardine populations (McCrae 

1994). Northern anchovy are also important for prey for many predator fish, sea birds, and 

marine mammals. 

Northern anchovy are frequently the dominant species impinged at SONGS, for example, 

comprising over 88 percent of the estimated impingement during 2003 (Table 2-1). 

Northern anchovy were also the most abundant fish species entrained at SONGS during the 

1979 studies (Table 2-3). Northern anchovy abundance along the southern California coast 

may fluctuate widely from year to year depending on climatological conditions, including El 

Niño events. 
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The northern anchovy is a broadcast spawner. Females can lay upwards of 30,000 eggs a 

year over multiple times. In southern California, northern anchovy spawn throughout the 

year with peaks from winter to spring (Love 1996). Eggs and larvae are planktonic, larvae 

begin schooling at 11-12 mm and transition to juveniles at 35-40 mm at about 70 days posthatch (Kucas 1986). Many of the anchovies will mature before the year is up but the rest 

will mature by their second year of life (Kucas 1986). They can live up to 7 years with a size 

near 9 inches. 

Northern Anchovies will usually migrate offshore during the winter and come back inshore in 

the spring. These movements may alter their seasonal susceptibility to impingement at 

SONGS with low impingement during late fall and winter than at other times of year. 

3.3.2 Queenfish 

Queenfish are members of the croaker family (Sciaenidae) and are commonly caught by 

pier anglers. In addition, queenfish are common in coastal trawl surveys in the Southern 

California Bight (MBC 1995a). Queenfish were the most abundant species collected in 6.1 

meter isobath trawl surveys in Santa Monica Bay between 1982 and 1984 (MBC 1997). 

Queenfish are found from Baja California to Yaquina Bay, Oregon, although they are rare 

north of Monterey, California. They are a schooling species which inhabit shallow water 

near pilings and sandy bottoms in summer (Love 1991). Queenfish typically inhabit depths 

from 4 to 27 feet, but can often be found at depths up to 180 feet. They congregate near 

inshore areas during the day and move offshore at night to feed on crustaceans and 

plankton (Herbinson et al. 2001). 

Queenfish spawn from March to April with females maturing at 100-105 mm SL (DeMartini 

and Fountain 1981). The eggs are free floating. Larval queenfish less than an inch begin 

appearing in late summer and fall at depths of 20 to 30 feet. Immature queenfish continue 

moving shoreward until reaching the surf zone at 1 to 3 inches in length. 

Queenfish were the second most abundant species collected in impingement samples in 

2003 and entrainment samples collected in 1979-1980 (SCE 2003; SCE 1983). Queenfish 

impingement abundance at SONGS has fluctuated, and, as in 1998 (SCE 1998), they are 

sometimes the most numerous species impinged. Queenfish abundance fluctuates in the 

Southern California Bight as a result of El Niño. Queenfish populations exhibited sharp 

declines during several strong El Niño periods including the following years: 1982-1983, 

1986-1987, and 1997-1998 (Herbinson et al. 2001). 

3.3.3 Pacific Sardine 

Pacific sardine is a member of the family Clupeidae (herrings). Until the population declined 

sharply in the mid-1940’s, leading to its eventual complete collapse in the early 1960’s due 

to overfishing (McCrae 1994), Pacific sardine was an extremely important commercial fish. 

In recent years it has been recovering in numbers, leading the California Department of Fish 

and Game to indicate that the Pacific sardine resource has fully recovered (CDF&G press 

release). The directed fishery harvests for the potentially growing sardine industry in 

southern California are mostly canned for human consumption overseas, with a small 

proportion sold fresh for human consumption or animal food. Pacific sardine are also 

important prey for a wide selection of fish, seabirds, and marine mammals. 
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The Southern California coast is the main spawning ground for Pacific sardines. Pacific 

sardine spawn pelagic eggs and larvae year round with a fall and winter minimum and a 

spring and summer maximum. The females may lay upwards of 200,000 eggs in a season, 

which hatch in about three days. They will mature between 7 and 9.5 inches sometimes 

within their first year. They can live up to 25 years and grow to a maximum size of about 16 

inches (McCrae 1994). Pacific sardines conduct annual migrations northward early in 

summer and return southward in fall, migrating farther with each year of life. 

In the 2003 impingement, Pacific sardines were the third most abundant species with an 

estimated 63,339 individuals impinged for the year (table). This made up 1.8 percent of the 

total impingment for 2003 (Table 2-1). Over 70 percent of the Pacific sardine impingement 

occurred from July to October (Table 2-2). 

3.3.4 White Croaker 

The white croaker is one of eight species of the family Sciaenidae (drums/croaker) found 

along the California coast. The white croaker is an important commercial and sport fish in 

California. The majority of the fish are sold at fresh fish markets under the name kingfish 

and there is also a small market for use as bait fish. White croaker are found from Baja 

California to British Columbia, usually at depths of 6 to 75 m within bays and estuaries that 

have sandy bottoms (Wang 2001). 

White croaker may spawn throughout the year, but the majority of spawning takes place 

from January to March in southern California (Gregory 2001). Females can spawn up to 24 

times in a season producing a maximum of 37,200 eggs per spawning (Gregory 2001). The 

eggs hatch in about one week. Eggs and larvae are pelagic, and post-flexion larvae settle 

to the bottom as they develop (Love 1984). Juveniles are found near the bottom in 3-6 m of 

water, then migrate to deeper water as they mature. Both sexes mature between one to 

four years with a size range of 5.5 to 7.5 inches (Gregory 2001). The maximum recorded 

length of a white croaker is 16.3 inches, but most fish will generally grow to about 12 inches. 

Impingement monitoring at SONGS indicates an overall decline in white croaker 

impingement until 1999, after which impinged numbers of this species increased (SCE 

2003). In the 1979-1980 entrainment monitoring program, white croaker were the second 

most abundant species entrained. 

3.3.5 Kelp/Sand Bass 

Kelp bass (Paralabrax clathratus), sand bass (P. nebulifer) and spotted sand bass (P. 

maculatofasciatus) are members of the family Serranidae (sea basses and groupers). All 

three species are popular with southern California recreational fishermen. Kelp bass and 

sand bass are frequently caught by commercial passenger fishing vessels (CPFVs) and 

private boaters in the vicinity of the San Onofre Nuclear Generating Station. Spotted sand 

bass are typically restricted to sandy or muddy bottom habitat within shallow bays, harbors, 

and coastal lagoons (Hovey and Allen 2001) and are found infrequently near SONGS. Early 

records of the commercial catch of these three similar species were grouped as “rock bass”. 

A steady decline in the catch of rock bass following World War II prompted conservation 

measures, which in 1953 made commercial fishing for rock bass illegal in California waters. 

Kelp bass are typically found in shallow water from the surface to 150 feet (46 m) closely 

associated with high relief structures, including kelp. They range throughout the water 
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column, but seem to concentrate between eight and 70 feet (2.4 and 21.3 m.) In general 

they live solitary lives but form assemblies to spawn and to feed on small schooling fish 

including anchovies, sardines, surfperch and queenfish. They also eat squid, octopus, 

crabs, shrimps and amphipods. Spawning occurs primarily around the full moon from April 

through November peaking in the summer months. Kelp bass produce pelagic eggs 0.04 

inches (0.1 cm) in diameter (Allen and Hovey 2001). Larvae remain in the plankton for 28 

to 30 days at which time they settle out in shallow water in attached as well as drift algae 

including kelps. 

Barred sand bass form large breeding aggregations over sandy bottoms at depths of 60 to 

120 feet in the summer months. Spawning occurs from April through November, usually 

peaking in July. Barred sand bass produce a large number of small pelagic eggs that enter 

the plankton in coastal waters. Young of the year sand bass begin appearing in shallow, 

nearshore waters in the early fall. (Allen and Hovey 2001) 

Spotted sand bass spawn in the warm summer months, from late May to early September 

and the multiple sized oocytes in gravid females indicates that this a multiple spawning 

species. They grow rapidly during their first two years. Some may reach as much as 8.8 

inches (22.4 cm) at the end of their first year. (Hovey and Allen 2001) 

Kelp bass and barred sand bass are common in fish impingement samples at SONGS and 

eggs and larvae of this genus have been common in plankton samples taken in the vicinity 

of SONGS. 

3.3.6 Spiny Lobster 

The California spiny lobster ranges from Monterey Bay, California to Manzanillo Mexico and 

a small part of the Gulf of California. The majority of the population is found between Point 

Conception, California and Magdalena Bay, Baja California. Adult lobsters usually inhabit 

rocky areas from the intertidal zone to depths of 240 feet or more. 

Spiny lobsters mate from November through May. Fertilized eggs are attached to the 

underside of the female’s tail primarily in May and June. “Berried“ females are generally in 

water less than 30 feet (9.1 m) deep and carry their eggs for about 10 weeks. Sampled 

females carried between 120,000 and 680,000 eggs, depending on the size of the female. 

Spiny lobster eggs hatch into tiny, transparent larvae known as phyllosomas that go through 

12 molts. They drift with the prevailing currents feeding on other planktonic animals. They 

may drift offshore out to 350 miles (563 km), and may be found from the surface to a depth 

of over 400 feet (122 m). After five to nine months, the phyllosoma transforms into the 

puerulus or juvenile stage which actively swims inshore where it settles to the bottom in 

shallow water and starts to grow if the habitat is suitable. (Barsky 2001) 

Spiny lobsters are important to the commercial fisheries and sport diving community of 

southern California. From 1989 through 1999 commercial landings ranged from 600,000 to 

950,000 pounds (272,155 to 430,912 kg) per year in California. (Barsky 2001). Spiny 

lobsters are occasionally observed during fish impingement sampling at SONGS and are 

frequently released by the FRS during fish return and “Fish Chase” procedures. 
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4. PROPOSED IMPINGEMENT MONITORING 

As discussed in Sections 2.3.1 and 2.4, there is a substantial amount of data on 

impingement at SONGS over the life of the units, limited only in that sampling has been 

conducted only quarterly since 1999. One year of additional sampling is proposed to 

provide current impingement data, reflecting current conditions in the Southern California 

Bight near the Station and accounting for temporal variations in impingement by sampling at 

increased (biweekly) frequency (SCE 2003). 

Data produced by this monitoring program will define the species and life stages impinged, 

as well as their numbers and biomass on a time (biweekly and annual) and per-volumepumped (MG of cooling water) basis for each of the two intakes. The results will be 

incorporated into the IM&E Characterization Study, as described in Section 1.2. 

This section addresses the proposed sampling plan, sampling gear and the method for its 

deployment, sample processing procedures, collection of relevant ancillary information, and 

data analysis. A quality assurance program for the impingement monitoring program is 

described in Section 6. 

4.1 IMPINGEMENT SAMPLING 

The impingement monitoring program is recommended to span at least one year (12 

months) and to include both units 2 and 3. A second year of monitoring should not be 

necessary given that interannual variations can be characterized based on many years of 

impingement monitoring at the Station. 

Impingement will be sampled over one continuous 24-hour period every other week 

throughout the year, and all operating screens will be sampled at the same time. Sampling 

will be scheduled to begin on the same day (e.g., Tuesday). If none of the units is 

scheduled to operate during the specified day of sampling, an alternate sample day during 

the same bi-weekly period will be selected in order to get representative fish density 

(number of impinged fish per flow volume) measurements. Biweekly sampling should be 

sufficient to describe seasonal patterns in impingement, as requested in the Phase II Rule, 

and data from the additional year of monitoring can be used together with biweekly 

monitoring results from years prior to 1999 to account for interannual variation in 

impingement. 

Sampling to detect diel variations in impingement is not possible given the existing 

regulatory water quality objectives. This is because most impingable fish entering the 

SONGS CWIS are able to resist impingement by swimming away from the screens or 

finding quiescent areas where they can temporarily reside. These fish may reside for days 

or weeks before being impinged. Sampling impingement every six hours, for instance, 

would not accurately depict which fish entered the intake during the past six hours unless a 

toxicant was added to the water to sweep the screenwell clean every six hours. Instead, the 

SONGS Comprehensive Demonstration Study will depend on historical studies dealing with 

diel variations in impingement. Diel variations in entrainment of larvae will be possible to 

measure because these organisms are unable to resist the flow velocities found in the 

SONGS screenwell. 
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4.1.1 Impingement Sampling Gear and Deployment 

Sampling gear and deployment for these studies will be the same as used in prior 

impingement monitoring at SONGS. Prior to sampling, the traveling screens will be rotated 

for at least one full cycle to remove fish and debris accumulated prior to the sampling 

interval. Once this cleaning process has been accomplished, sampling will be initiated by 

placing the collection basket at the outfall of the screen wash troughs for Units 2 and 3. The 

collection baskets or nets will have 3/8-inch mesh. 

The collection baskets will be removed and their contents will be emptied into a receiving bin 

allocated for that collection interval, and subsequently processed. The collection baskets 

are sufficiently sized at SONGS, and will be emptied frequently enough, to prevent overflow 

caused by debris buildup during the collection interval. Fish and debris can be removed 

from the collection baskets or nets anytime during the 24-hour period if there is any risk of 

them becoming too full and overflowing. However, overflow drains surrounding the 

collection bins at SONGS re-circulate any overflow back to the collection bin. 

This sampling process will be repeated during each of the 24-hour sampling periods. 

4.1.2 Impingement Sample Processing 

Samples from the two screen wash troughs (Unit 2 and Unit 3) will be kept separate during 

processing. Each sample will be processed by counting and identifying all fish to the lowest 

practicable taxonomic level. Individuals that cannot be identified to species in the field will 

be preserved for future identification by a taxonomy expert (see Section 6). 

Fish in the sample will be sorted by species and counted. Following sorting, each fish will 

be measured to the nearest mm, standard length (SL), except elasmobranches which will be 

measured by total length (TL). If the number of specimens in the sample for a particular 

species is large, the species count can be estimated by subsampling. A subsample of 100 

individuals of each species will be weighed and the total sample will be weighed. The 

number of individuals in the whole sample will be estimated from the ratio of the total sample 

weight to the subsample weight total and the count within the subsample. Lengths will be 

measured for 100 individuals in the subsample, or all of them if less than 100 occur. 

The general condition of impinged organisms will be observed as they are processed. 

Unusual condition, such as signs of disease, parasites or injury, will be noted. Samples may 

be frozen at the completion of processing and saved for possible inclusion in quality control 

(QC) testing. Once it is determined that a sample is no longer needed for QC purposes, it 

will be disposed of in an approved manner. QC of sample processing is discussed in 

Section 6. 

4.2 FISH RETURN SYSTEM SAMPLING 

The fish return system (FRS) monitoring program is recommended for one year (12 months) 

and to include both Units 2 and 3. The duration of the monitoring program will ensure 

efficiency data is collected during peak impingement and bypass periods and over the range 

of life stages and sizes representative of entrapment at the Station. The purpose of the 

monitoring program is to verify the FRS performance efficiency estimates from prior studies 

and attempt to provide unbiased estimates of FRS performance for fish <50 mm in length 

(see Section 5.2). The FRS monitoring program shall be conducted in conjunction with 
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impingement sampling, to determine the diversion efficiency of the fish return system. 

Samples will be collected from the fish elevator at 12 hour intervals over two 24-hr periods 

each month using gear and methods described in the prior FRS studies (Love et al 1989), 

modified to also sample larval fish. The sample will coincide with the 24-hour impingement 

sample. All four circulating water pumps will be operated during the sample. If any pumps 

are out of service, the FRS sample and the impingement sample will be rescheduled during 

the same biweekly impingement period. During each sampling interval, the contents of the 

elevator basket will be sampled using two 15-inch diameter nets (on of 3/8” mesh, one of 0.5 

mm mesh) to collect juvenile and older fish as well as larvae. The first net will use 3/8” 

mesh to catch impingeable fish. The second net will use 0.5 mm mesh to retain entrainable 

larvae. Mesh sizes may be adjusted, if necessary, to improve sampling efficiency. Any 

changes in equipment or procedures used in this sampling will be requested in advance of 

the CRWQCB. As fish are poured into the sluiceway, two aliquot samples are taken with the 

intent to sample at least one tenth of the fish collected (Love et al 1989). This process is 

repeated until fish are no longer present in the elevator basket. 

Prior to sampling with nets, any fish in the return elevator that are stunned or dead will be 

recorded by species, estimated length, and condition. Fish in the net samples will be sorted 

by species and counted. Following sorting, each fish will be measured to the nearest mm 

standard length (SL). If the number of specimens in the sample for a particular species is 

large, the species count can be estimated by subsampling. A subsample of 100 individuals 

will be weighed and the total sample will be weighed. The number of individuals in the 

whole sample will be estimated from the ratio of the total sample weight to the subsample 

weight total and the count within the subsample. Lengths will be measured for 50 

individuals in the subsample. Individuals that cannot be identified to species in the field will 

be preserved for future identification by a taxonomy expert (see Section 6). 

The general condition of netted organisms will be observed as they are processed. Unusual 

condition, such as signs of disease, parasites or injury, will be noted. Samples may be 

frozen at the completion of processing and saved for possible inclusion in quality control 

(QC) testing. Once it is determined that a sample is no longer needed for QC purposes, it 

will be disposed of in an approved manner. QC of sample processing is discussed in 

Section 6. 

4.3 FISH CHASE EFFECTIVENESS SAMPLING 

The fish chase monitoring program is recommended for one year and to include all heat 

treatments at Units 2 and 3. The fish chase and subsequent heat treatment operations are 

typically conducted on an as-required basis depending on the amount of biofouling in the 

intake conduit; a total of nine heat treatments were conducted for Unit 2 and seven for Unit 3 

in 2003. 

The fish chase monitoring program will follow sampling procedures used in previous 

monitoring studies. Water temperatures will be elevated slowly to agitate fish residing in the 

CWIS. These fish are guided toward the fish return by manipulating cross-over gates in the 

screenwell which slowly warms the water and creates eddy currents to dislodge fish residing 

in low flow habitats. A target temperature of 83oF will be used during fish chase operations, 

however higher temperatures are sometimes needed to dislodge warm water species such 

as yellowfin croaker, sargo, and zebra perch (SCE 2003). The process dislodges fish and 

causes them to move toward the fish return system. The operation shall be monitored by 

fisheries biologists to ensure fish are not being overly stressed. The number of fish 
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ASA ANALYSIS & COMMUNICATION, INC. A4-4 Proposed Impingement Monitoring 

impinged during heat treatment operations and the number of fish released back to the 

ocean during fish chase procedures will be recorded along with data on fish condition, 

species composition, operational status, and water temperatures. 

Each sample will be processed, as is currently done, by counting and identifying all fish 

visually to the lowest practicable taxonomic level. In order to save as many fish as possible 

and work within the critical time/temperature path, no sampling is possible. 

4.4 RELEVANT ANCILLARY INFORMATION 

There is ancillary information that will be recorded that is relevant to environmental 

conditions at the time of impingement monitoring, as well as plant operation data needed to 

estimate total impingement. Environmental data relevant to each sample will be recorded 

on an accompanying field data sheet. In addition to date and sample start/end time 

recordings, these data will include operation parameters for the intake (identify screens and 

pumps operating); tidal stage; and water temperature and water clarity all recorded at the 

beginning of each collection. A unique sample identification number will be assigned to 

each sample. Other relevant observations to be recorded include air temperature, wind 

speed, cloud cover, and precipitation. 

Plant operation records must be available to determine the operation regime during the 

sampled and unsampled days in each month. Data required include hourly pumping rates 

(or volumes) for each unit, generation output (MWh), and discharge water temperature. 

Pumping rate or volume data will allow impingement estimates to be based on per unit 

volume pumped. 

4.5 DATA ANALYSIS 

The objectives of the impingement data analysis will be to: 

1. define the fish species impinged; 

2. estimate impingement rates expressed as density per million gallons (MG) of cooling 

water pumped on a daily, biweekly, and annual basis; 

3. estimate total numbers and biomass by species on a biweekly and annual basis for 

the year of sampling; 

4. characterize impinged fish in terms of size and age distribution by species; 

5. estimate effectiveness of the fish return system; and 

6. estimate the effectiveness of fish chase operations. 

The results of the proposed new studies will be used in conjunction with available 

information from prior studies at SONGS, as well as information from studies at other power 

plants and the general literature, to estimate the effectiveness of the existing fish protection 

features of the SONGS intake for reducing impingement mortality (Figure 4-1). As shown in 

figure 4-1, historical information that will be used includes, but is not limited to: 

• Annual impingement monitoring conducted at SONGS since 1983; 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A4-5 Proposed Impingement Monitoring 

• Velocity cap studies conducted by the University of Washington, Fisheries Research 

Institute at Huntington Beach and Ormond Beach Generating Stations; 

• Previous 316(b) studies conducted at SONGS Unit 1; 

• Prior FRS studies conducted at SONGS; 

• Prior fish chase monitoring conducted at SONGS; 

• Impact analyses completed by the Marine Review Committee for the California 

Coastal Commission, and 

• Other existing and future available information relevant to the evaluation of 

impingement and the effectiveness of the existing SONGS fish protection 

technologies, including laboratory studies and studies conducted at other cooling 

water intake systems. 

Estimates of the individual effectiveness of the velocity cap, FRS, and fish chase procedure 

will be made based on all available information and combined to yield an estimate of the 

total percent reduction in impingement mortality from the fish protection technologies and 

operations existing at SONGS. The results will also be used to estimate the annual 

impingement mortality for the Calculation Baseline (Figure 4-1). Results of the proposed 

additional year of impingement monitoring and prior monitoring studies at SONGS will be 

used to characterize interannual variation in impingement rates., 

Impingement rates characteristic of SONGS, expressed as density per million gallons (MG) 

of cooling water pumped and adjusted to reflect the impingement rates for the Calculation 

Baseline (i.e., in the absence of SONGS’ fish protection controls), will also be used to 

estimate reductions in impingement mortality associated with scheduled outages occurring 

over a 5-year period of forecasted Station operations. 

Study results will be incorporated into the IM&E Characterization Study and submitted as 

part of the CDS, as discussed in Section 1.2. 
SAN ONOFRE 

ASA ANALYSIS & COMMUNICATION, INC. A4-6 Proposed 

Impingement

Densities

SONGS

Impingement

Monitoring

Adjusted

Impingement

Densities

Velocity Cap

Effectiveness

SONGS FRS

Effectiveness

Fish Chase

Effectiveness

Prior Imp Monitoring - Quarterly, Heat Treatme

New Imp Mon - Biweekly, Heat Treatme

'84-'94, '99 - SONGS FRS Studies

New FRS Studies - peak periods(screens, el

Prior Studies - Fish Chase Monitoring

New - Fish Chase Monitoring [Heat Treatme

HBGS, OBGS Studies ('84-'85), Lab Study, Litera

Impingement

Baseline Losses

Projected Flows Over 5-year

Period (with scheduled outages)

METRIC DATA TYPE DATA SOURCE STUDIES

Rated Flows - Entire Year

HBGS, OBGS, RBGS imp. monitoring, if availa

Figure 4-1. Conceptual model for estimating baseline impingement losses at the San Onofre Nuclear Generating S

studies shown in bolded boxes). 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A5-1 Proposed Entrainment Monitoring 

5. PROPOSED ENTRAINMENT MONITORING 

As discussed in Section 2.3.2, entrainment monitoring was conducted at the San Onofre 

Nuclear Generating Station during 1979 and 1980 at Unit 1 (prior to construction of Units 2 

and 3). Additional studies, focusing on Units 2 and 3, ran from August 1979 through 

September 1986. These studies included pre- and post-operational periods so that a 

Before-After-Control-Impact (BACI) analysis could be utilized to estimate entrainment 

losses. This monitoring provides useful, but dated entrainment information for SONGS, as 

the data was collected over 19 years ago.. The proposed entrainment monitoring will 

supplement the previous studies and will document the current entrainment rates and 

species and life stage composition in entrainment samples. The following sections describe 

the sampling design, equipment and methodology. One full year of entrainment monitoring 

will be conducted. 

5.1 ENTRAINMENT AND SOURCE WATER SAMPLING DESIGN 

Entrainment monitoring will be done biweekly for one year. This sampling frequency has 

been widely used as the standard for entrainment sampling at other facilities, including 

recent studies in California, and considered adequate to describe seasonal patterns in 

entrainment, as requested in the Phase II rule (EPRI 2005). 

Sampling will occur over a full 24-hour period for each sampling event. Sampling will be 

scheduled to begin on the same day of the week (e.g., Tuesday). One sample will be taken 

every 6 hours according to the following time intervals: 0-0600, 0600-1200, 1200-1800 and 

1800-2400 hours). Exact sampling dates may fluctuate depending on required nuclear 

maintenance outages and heat treatment schedules. 

5.1.1 Entrainment Sampling Gear and Deployment 

Samples will be collected within the CWIS intake screenwell in front of the traveling bar 

racks. Samples will be collected by use of standard plankton nets. Final sampling protocol 

will be selected in consultation with the CRWQCB, considering representativeness of actual 

entrainment, temporal coverage of sampling, sampling accuracy and precision, and 

constraints imposed by operational and safety requirements at SONGS. As part of an 

overall evaluation of the best practicable sampling location and gear for entrainment 

monitoring at SONGS, a pilot study will be conducted to compare ichthyoplankton densities 

collected in standard plankton tows at the SONGS intake (Source Water samples) with 

densities obtained using plankton nets within the station’s cooling water system. A series of 

at least ten concurrent samples will be collected during the same time period at the 

beginning of the sampling program. 

In-plant entrainment samples will be collected from the well mixed area at the cooling water 

intake screenwell within the station site (Figure 5-1). Sampling will be performed using a 

standard plankton net with a 60-cm diameter net ring with 333-μm Nitex© nylon mesh. Each 

net will be equipped with a calibrated flowmeter, allowing the calculation of total flow 

volume. Each sample will sample a minimum of 30 mP

3

P

 of water. Larger samples will be 

obtained if feasible. Clogging of the plankton nets may limit sample volume because of 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A5-2 Proposed Entrainment Monitoring 

SONGS’ location adjacent to kelp forests. Netting will be of sufficient size and surface area 

to reduce the likelihood of net extrusion of smaller larvae and net overflow 

5.1.2 Source Water Sampling Gear and Deployment 

Samples will be collected as close as practicable to the intake. These samples are 

designed to characterize the larvae of target species occurring in the vicinity of the intake 

and provide a comparison to historical data. Samples will be collected by use of standard 

plankton nets. Samples will be collected monthly at 6-hour intervals over 24-hour period, 

coinciding, when possible, with in-plant entrainment monitoring. Netting will be of sufficient 

size and surface area to reduce the likelihood of net extrusion of smaller larvae and net 

overflow 

The offshore net samples will be collected with equipment similar or equal to that used inplant, a bongo frame fitted with 60-cm diameter net rings with plankton nets constructed of 

333-μm Nitex© nylon mesh. Each net will be equipped with a calibrated flowmeter, allowing 

the calculation of total flow volume. 

Each sample will process a minimum of 30 mP

3

P

 of water. Larger samples will be obtained if 

feasible. Clogging of the plankton nets may limit sample volume because of the proximity of 

the SONGS intake to adjacent kelp forests. 

5.1.3 Sample Processing 

At the conclusion of the samples, the nets will be washed down to concentrate captured 

organisms and detritus in the collection cup attached to the net. The concentrated sample 

will be preserved in a 4-percent buffered formalin-seawater solution, then, after 

approximately 72-hours, will be transferred to 70% ethanol solution. Further processing of 

the sample will occur in the laboratory. 

In the laboratory, fish larvae, juveniles and targeted invertebrate larvae will be sorted and 

removed from the sample. If the sample contains a large number of specimens or a large 

amount of detritus, subsampling will be performed using a Folsom splitter or other 

appropriate sample volume splitting device. If subsampling becomes necessary, 

subsamples will be processed until a minimum of 200 identifiable specimens are found, but 

counts for individual subsamples will be maintained. Fish eggs will not be sorted or 

identified because a full assessment of their abundance would require different sampling 

techniques and they cannot be identified to the same taxonomic levels as fish larvae. 

Technicians trained in taxonomy will identify the specimens to life stage and the lowest 

practicable taxon. Counts will be made by species (taxon) and life stage. Up to 30 

specimens per species and life stage will be measured to the nearest 0.1 mm. 

5.2 FISH RETURN SYSTEM STUDIES 

The fish return system (FRS) monitoring program is proposed for one year (12 months) at 

both Units 2 and 3. The monitoring program shall be conducted monthly in conjunction with 

the impingement studies discussed in Section 4.2, with the objective to quantify the 

diversion efficiency of the FRS for small fish (<50 mm), including larvae and early juveniles, 

that may otherwise be entrained at an intake without this fish protection technology. 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A5-3 Proposed Entrainment Monitoring 

In conjunction with impingement and entrainment sampling, 24-hour fish elevator samples 

will be collected once per month. All four circulating water pumps will be operated for the 

unit to be sampled. For each interval, the contents of the elevator basket will be subsampled using two 15-inch wide “double” nets equipped with both large (approximately 5 

mm) mesh to catch larger fish and debris followed by a second net of approximately 1-2 mm 

mesh, sufficient to collect larger larvae and early juveniles. Based on initial testing, the 

process will be adjusted to sample a portion of the elevator volume sufficient to yield at least 

200 fish per sample (number of organisms). This process is repeated until fish are no longer 

present in the elevator basket. 

If the number of specimens in the sample for a particular species is large, the count and 

condition may be taken on a subsample. 

In the laboratory, all fish larvae and juveniles will be sorted and removed from the sample. If 

the sample contains a large number of specimens, subsampling will be performed using a 

Folsom splitter or other appropriate sample volume splitting device. If subsampling 

becomes necessary, subsamples will be processed until a minimum of 200 identifiable 

specimens are found, but counts for individual subsamples will be maintained. Technicians 

trained in taxonomy will identify the specimens to life stage and the lowest practicable taxon. 

Counts will be made by species (taxon) and life stage. Up to 30 specimens per species and 

life stage will be measured to the nearest 0.1 mm. 

5.3 RELEVANT ANCILLARY INFORMATION 

There is ancillary information that must be recorded relevant to environmental conditions at 

the time of entrainment monitoring, as well as plant operation data needed to estimate total 

entrainment. Environmental data relevant to each sample will be recorded on an 

accompanying field data sheet at the start of each 6-hour entrainment sampling period or 

24-hour impingement and FRS sampling period. In addition to date and sample start/end 

time recordings, these data will include operation parameters for the intake (identify pumps 

operating); tidal stage; and water temperature, and water clarity, all recorded at the 

beginning of each collection. A unique sample identification number will be assigned to 

each sample. Other relevant observations will be recorded, such as air temperature, wind 

speed, cloud cover, and precipitation. 

Plant operation records will be obtained to determine the operation regime during the 

sampled and unsampled days in each month. Data required include hourly pumping rates 

(or volumes) for each unit, generation output (MWh) and discharge water temperature. 

5.4 DATA ANALYSIS 

The objectives of the entrainment data analysis will be to: 

1. define the fish species and life stages entrained; 

2. estimate entrainment rates expressed as density per million gallons (MG) of cooling 

water pumped on a daily, biweekly, and annual basis; 

3. estimate total numbers entrained by species on an hourly (for diel variability), 

biweekly (for seasonal variability), and annual basis for the year of sampling; 

4. characterize the life stage and size distribution of entrained organisms; and 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A5-4 Proposed Entrainment Monitoring 

5. estimate the effectiveness of the fish return system for reducing entrainment of larval 

and juvenile fish. 

The results of the proposed new studies will be used in conjunction with available 

information from prior studies at SONGS, as well as information from studies at other power 

plants and the general literature, to estimate the effectiveness of the existing fish protection 

features of the SONGS intake for reducing impingement mortality. As shown in Figure 5-2, 

historical information that will be used includes, but is not limited to: 

• Prior entrainment and near-field ichthyoplankton monitoring conducted at SONGS; 

• Prior FRS studies conducted at SONGS; 

• Other existing and future available information relevant to the evaluation of 

entrainment and the effectiveness of the existing SONGS fish protection 

technologies, including laboratory studies and studies conducted at other cooling 

water intake systems. 

Estimates of the effectiveness of the FRS will be made based on all available information 

and used to calculate a percent reduction in entrainment from this fish protection 

technology. The results will also be used to estimate the annual entrainment for the 

Calculation Baseline (Figure 5-2). Results of the proposed additional year of entrainment 

monitoring and prior entrainment (1979-80) and nearfield ichthyoplankton (1982-86) 

monitoring studies at SONGS will be used to characterize interannual variation in 

entrainment rates, 

Entrainment rates characteristic of SONGS, expressed as density per million gallons (MG) 

of cooling water pumped and adjusted to reflect the entrainment rates for the Calculation 

Baseline (i.e., in the absence of SONGS’ fish protection controls), will also be used to 

estimate reductions in entrainment associated with scheduled outages occurring over a 5-

year period of forecasted Station operations. 

Study results will be incorporated into the IM&E Characterization Study and submitted as 

part of the CDS, as discussed in Section 1.2. 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A5-5 Proposed Entrainment Monitoring 

Figure 5-1. Location of In-Plant Entrainment Sampler. 
SAN ONOFRE 

ASA ANALYSIS & COMMUNICATION, INC. A5-6 Proposed 

Entrainment

Densities

SONGS Entrainment

Monitoring

Adjusted

Impingement

Densities

SONGS FRS

Effectiveness

Prior Ent. Monitoring - ['79 

Prior Ichthyoplankton Monitoring 

New Ent. Mon. - Weekly-Biw

Entrainment

Baseline Losses

Projected Flows Over 5-year

Period (with scheduled outages)

METRIC DATA TYPE DATA SOURCE STUDIES

Rated Flows - Entire Year

New FRS Studies - Monthly with Imp

(Discharge, Elevator, Fish <50 

Ent Length Frequency Data at Shorelin

Figure 5-2. Conceptual model for estimating baseline entrainment losses at the San Onofre Nuclear Generating St

studies shown in bolded boxes). 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A6-1 Quality Assurance 

6. QUALITY ASSURANCE 

An essential part of the proposed monitoring programs will be a quality assurance plan 

instituted to ensure that the data generated by the programs meet an acceptable standard of 

quality. Quality assurance (QA) is defined as an integrated system involving quality 

planning, quality control, quality assessment, quality reporting, and quality improvement to 

ensure that a product or service meets defined standards of quality with a stated level of 

confidence. The USEPA has published guidance documents (e.g., USEPA, 1995, USEPA 

2000; USEPA 2002a, USEPA 2002b) for preparing and implementing project-specific quality 

assurance plans for their staff and for contractors funded by their organizations to follow, 

known as Quality Assurance Project Plans (QAPPs). These documents will be used to 

prepare a QAPP that fits the needs of the proposed impingement and entrainment programs 

prior to the initiation of sampling. 

A QAPP has four basic element groups: project management, data generation and 

acquisition, assessment and oversight, and data validation and usability. Within these four 

groups there can be as many as 24 elements. Rather than address each of these elements, 

the following highlights aspects that are particularly relevant to the execution of these 

programs. 

6.1 PROGRAM MANAGEMENT 

This Impingement and Entrainment Sampling Plan provides many of the elements 

necessary for the program management functions of a QAPP, such as problem definition 

and background, and project and task descriptions. Other program management functions 

of a QAPP that are provided in the Plan include presentation of the project objectives and 

the interrelationships among the project tasks that direct the course of studies and identify 

information endpoints. An important element is the project organization, which identifies the 

roles and responsibilities of project personnel. A project organization chart identifies project 

personnel, whose qualifications (e.g., experience and specialized training) can be reviewed, 

as well as lines of communication and authority. The project organization chart will show 

individuals whose responsibility is to conduct various aspects of the quality assurance 

program. 

The QAPP will set data quality objectives and criteria. Methods will be specified to ensure 

the desired level of precision, comparability, and completeness. In terms of impingement 

mortality and entrainment quantification, the USEPA has not set standards for precision of 

estimates, so the sampling design proposed in this Plan conforms to sampling effort and 

precision levels that currently are standard practice. If the USEPA publishes guidance on 

sampling methods in the future, including QA standards and desired or required levels of 

precision, the program design and methodology will address these standards. 

6.2 DATA GENERATION AND ACQUISITION 

This component of the QA program is the heart of the field and laboratory tasks undertaken 

to generate data on current impingement and entrainment rates at SONGS. Elements 

include sampling design, sampling methods, sample handling and custody, analytical 

methods, instrument maintenance and calibration, and quality control. Quality control is 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A6-2 Quality Assurance 

defined as activities whose purpose is to measure and control the quality of a procedure so 

that it meets the needs of its user. Quality control (QC) activities monitor the outgoing 

quality of the data and can lead to response actions to bring the data within control limits 

through various actions, such as retraining of personnel, repair or recalibration of 

equipment, or other similar actions. 

Sampling methods will be standardized so that they are repeatable and produce data that 

are comparable through time. This will be accomplished by preparing detailed Standard 

Operating Procedures (SOPs) for all activities, including sampling location and frequency, 

sampling gear and deployment, sample processing, data coding and recording, database 

entry, and to some degree, data analysis. The SOPs can be reviewed by all parties to reach 

consensus on their applicability, and will be adhered to by all project personnel. SOPs will 

provide a description of procedures to follow if obstacles to sampling or completion of all 

sampling activities are met, so that the acquisition of quality data can be maximized. The 

SOPs will describe procedures for sample handling and custody, including required 

signatures and blank forms for associated labels and logs. Also included will be projectspecific data sheets, variable definitions and coding instructions. Equipment and instrument 

specifications will be described, including levels of precision and calibration methods for 

ensuring accuracy. 

Systematic QC procedures will be instituted to verify recorded data. The primary area 

where these QC procedures will be used is sample processing, e.g., sorting of eggs and 

larvae from detritus in entrainment collections, impingement fish counts, species 

identification, and length and weight measurements. Processed impingement and 

entrainment samples may be subjected to a statistically-based QC procedure, such as 

continuous sampling plans (CSP) or MIL-STD 105 methodology derived from a 

manufacturing environment and applied to environmental monitoring programs (Young et al. 

1992). The sampling plans implemented under these procedures have a specified average 

outgoing quality limit (AOQL), which represents the maximum fraction of all items (e.g., 

measurements, taxonomic identifications or counts) or lots (e.g., whole samples) that could 

be defective as a worst case. A defective item could be a measurement or count that falls 

outside of a specified tolerance limit (e.g., plus or minus 1 to 10 percent). In practice, the 

average outgoing quality (AOQ) is typically much better than the AOQL. 

6.3 ASSESSMENT AND OVERSIGHT 

Assessment and oversight is the process of determining whether the QA plan is being 

implemented as designed. For the proposed programs, this will be accomplished primarily 

by conducting technical audits or surveillance of field, laboratory and data management 

activities. Experienced senior staff, designated by the organization chart, will accompany 

field personnel during a set number of sampling events to observe sampling activities and to 

verify that SOPs are being followed properly. These auditors also will observe laboratory 

and data management personnel during their activities on specified occasions. Variances 

from approved procedures will be documented and corrected, either by modifying SOPs to 

address any systematic problems or by testing and/or retraining staff, as necessary. Prior to 

the first scheduled sampling, a readiness review will be conducted to ensure that trained 

personnel, required equipment, and procedural controls (e.g., SOPs) are in place. A 

technical audit will be scheduled for the first month of sampling (or very soon thereafter) so 

that any necessary corrections can be made before significant data losses occur. Follow-up 

audits will be scheduled (e.g., quarterly) to monitor progress and address changing 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A6-3 Quality Assurance 

conditions, such as recruitment of new life stages or species, entrainment or impingement 

abundances, river stage or flow, new personnel, or plant operations. 

Another QC aspect for oversight is the maintenance of a voucher specimen collection and 

library of taxonomic keys and references to assist personnel with taxonomic identification. 

The voucher specimen collection will consist of preserved specimens that have been 

positively identified by a qualified taxonomist. Oversight also will be provided by procedures 

requiring that specimens that are not positively identifiable by field or lab personnel will be 

preserved and given to a qualified taxonomist for identification. 

6.4 DATA VERIFICATION, VALIDATION AND USABILITY 

Data verification and validation will be conducted by qualified biologists (e.g., QA manager 

or field/lab supervisors) during the course of the project to ensure that the resulting data will 

be suitable for use as intended. Project records, including field sampling logs, raw data 

sheets, sample chain-of-custody forms and instrument calibration logs, will be reviewed to 

verify that data were collected according to the QAPP. Data will be validated first by a 

review of datasheets and data files to find whether data are incomplete or appear to be 

inappropriate or out of a reasonable range of values. Data entry into the database also will 

undergo a 100 percent visual QC comparison to the data on the corresponding data sheets. 

Finally, data files will be subjected to error checking programs to detect outlying values 

either to investigate further or to eliminate if shown to be spurious. This investigation will 

require tracing the data to raw data sheets and consulting with field or lab personnel who 

recorded the data. All raw data sheets, log books and data files will be maintained for future 

reference. All computer files will be backed up on a daily basis while any data entry or 

editing procedures are ongoing. 
SAN ONOFRE IM&E SAMPLING PLAN 

ASA ANALYSIS & COMMUNICATION, INC. A7-1 Literature Cited 

7. LITERATURE CITED 

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DeMartini, E. E. and R. K. Fountain. 1981. Ovarian cycling frequency and batch fecundity 

in the queenfish, Seriphus politus; attributes representative of serial spawning fishes. 

Fish. Bull., U. S.i 79(3):547-560. 

Downs, D. I. and K. R. Meddock. 1974. Design of fish conserving intake system. Journal of 

the Power Division, Proceedings of the American Society of Engineers. 100, PO2. 

EFH Core Team for West Coast Groundfish. 1998. Essential fish habitat: west coast 

groundfish. 

Electric Power Research Institute (EPRI). 2005. Entrainment Abundance Monitoring 

Technical Support Document. EPRI Report 1011280. Palo Alto, CA. 

Foster, M. S. and D. R. Schiel. 1985. The ecology of giant kelp forests in California: a 

community profile. U. S. Fish and Wildlife Service. Biological Report 85(7.2). 152 pp. 

Gregory, P. A. 2001. California’s marine living resource: a status report. California 

Department of Fish and Game. 

Herbinson, K. T. , M. J. Allen, and S. L. Moore 2001. Historical trends in nearshore croaker 

(family Sciaenidae) populations in southern California from 1977 through 1998. pp. 253-

264 in S.B. Weisberg and D. Hallock (eds.), Southern California Coastal Water Research 

Project Annual Report 1999-2000, SCCWRP, Westminister, CA. 

Kucas, S. T., Jr. 1986. Species profiles: life histories and environmental requirements of 

coastal fishes and invertebrates (Pacific Southwest) – northern anchovy. U.S. Fish Wildl. 

Serv. Biol. Rep. 82(11.50). U.S. Army Corps of Engineers, TR EL-82-4. 11pp. 

Love, M. S., M. Sandhu, J. Stein, K. T. Herbinson, R. H. Moore, M. Mullin, J. S. Stephens, 

Jr. 1989. Analysis of fish diversion efficiency and survivorship in the Fish Return System 

at San Onofre Nuclear Generating Station. NOAA Technical Report NMFS 76. 16 pp. 

Love, R. M. 1991. Probably more than you want to know about the fishes of the Pacific 

Coast. Really Big Press. Santa Barbara, California. 

MacCall, A. and X. He. 2002. Status review of the southern stock of Bocaccio (Sebastes 

paucispinis). National Marine Fisheries Service. SCL Contribution #366. 

MBC Applied Sciences. 1995a. National Pollution Discharge Elimination System Joint 1995 

receiving water monitoring report for Mandalay Generating Station, Ormond Beach 

Generating Station, Scattergood and El Segundo Generating Stations, Harbor Generating 

Station, Long Beach Generating Station, Haynes and Alamitos Generating Stations. 1995 

survey. Combined report prepared for Southern California Edison and Los Angeles 

Department of Water and Power. 96-RD-001. 110pp. 
SAN ONOFRE IM&E SAMPLING PLAN 

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MBC Applied Sciences. 1997. 316(b) document for Scattergood, Haynes, and Harbor 

Generating Stations. Prepared for Los Angeles Department of Water and Power. 

McCrae, J. 1994. Oregon development species northern anchovy, Engaulis mordax. 

Oregon Department of Fish and Wildlife. 

MEC. 1987. MEC Biological Project. San Onofre Nuclear Generating Station. Monitoring 

Studies on Ichthyoplankton and Zooplankton. Final Report. 

MRC. 1989. Final report of the Marine Review Committee to the California Coastal 

Commission. MRC Document No. 89-02. 

SAIC. 1994. Review of Southern California Edison San Onofre Nuclear Generating Station 

316(b) Demonstration. Prepared for USEPA. 

Schuler, V. J. and L. E. Larson. 1975. Improved fish protection at intake systems. J. 

Eniron. Engr. Div., ASCE Vol. 101, No. EE6, Proc. Pap. 11756. Pp. 897-910. 

Southern California Edison Company (SCE). 1983. San Onofre Nuclear Generating Station 

Unit 1 316(b) Demonstration. Submitted to the California Regional Water Quality Control 

Board. 82-RD-95. 

Southern California Edison Company (SCE). 1988. San Onofre Nuclear Generating Station 

1987 Annual Analysis Report. Prepared by WESTEC Services, Inc.; Tekmarine, Inc.; 

Natural History Museum of Los Angels County; W. J. North; and Occidental College. 88-

RD-35. 

Southern California Edison Company (SCE). 1998. San Onofre Nuclear Generating Station 

Annual marine environmental analysis and interpretation. Prepared by SONGS 

Environmental Protection Group. 

Southern California Edison Company (SCE). 2004. San Onofre Nuclear Generating Station 

2003 Annual Analysis Report. Prepared by SONGS Environmental Protection Group. 

Stupka, R. C. and R. K. Sharma. 1977. Survey of fish impingement at power plants in the 

United States. Vol. III. Estuaries and Coastal Waters. ARGONNE National Laboratory, 

III. 310 pp. 

Thomas, G.L., L. Johnson, R. E. Thorne, W. C. Acker, 1979. Techniques for Assessing the 

Response of Fish Assemblages to Offshore Cooling Water Intake Systems. University of 

Washington, Fisheries Research Institute. FRI-UW-7927 

Thomas, G. L., R. E. Thorne, W. C. Acker, T. B. Stables, and A. S. Kolok. 1980a. The 

effectiveness of a velocity cap and decreased flow in reducing entrapment. University of 

Washington, Fisheries Research Institute. FRI-UW-8027. 

Thomas, G.L., L. Johnson, R. E. Thorne, W. C. Acker, 1980b. A Comparison of Fish 

Entrapment at Four Southern California Edison Company Water Intake Systems. 

University of Washington, Fisheries Research Institute. FRI-UW-8023. 
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Thorne, R. E., G. L. Thomas, W. C. Acker, L. Johnson, 1979. Two Applications of 

Hydroacoustic Techniques to the Study of Fish Behavior Around Coastal Power Generating 

Stations. Washington Sea Grant Program, University of Washington, WSG 79-2. 

U.S. Environmental Protection Agency (USEPA). 1995. Generic Quality Assurance Project 

Plan Guidance for Programs Using Community Level Biological Assessment in Wadeable 

Streams and Rivers. Office of Water. EPA 841-B-95-004. July, 1995. 

U.S. Environmental Protection Agency (USEPA). 2000. Guidance for Technical Audits and 

Related Assessments for Environmental Data Operations. (G-7). EPA/600/R-99/080, 

January 2000. 

U.S. Environmental Protection Agency (USEPA). 2002a. Guidance for Quality Assurance 

Project Plans. (G-5). Office of Environmental Information. EPA/240/R-02/009. December 

2002. 

U.S. Environmental Protection Agency (USEPA). 2002b. Guidance on Environmental Data 

Verification and Validation. (G-8). Office of Environmental Information. EPA/240/R-02/009. 

December 2002. 

Wang, J. C. S. 1986. Fishes of the Sacramento-San Joaquin Estuary and adjacent waters, 

California: a guide to the early like histories. Technical Report 9 (FS/B10-4ATR 86-9). 

Weight, R. H. 1958. Ocean cooling water systems for 800 MW power station. J. Power. 

Div. Proc. Amer. Soc. Civil Engr. Paper No. 1888. 22 pp. 

Young, J.R., R.G. Keppel, and R.J. Klauda. 1992. Quality assurance and quality control 

aspects of the Hudson River Utilities Environmental Studies. In: Smith, C.L.. Estuarine 

research in the 1980’s: Proceedings of the Seventh Symposium of the Hudson River 

Environmental Society. pp. 303-322.
 Appendix

B PROPOSED METHOD FOR EVALUATION OF 

ENVIRONMENTAL BENEFITS 

See following pages.
B-1

Deriving Economic Benefits of Reduced Impingement and Entrainment at SCE’s 

San Onofre Nuclear Generating Station 

Background 

For use of the Cost-Benefit test under the site-specific standards, Southern California 

Edison is required to have a Benefits Valuation Study prepared. The final 316(b) Phase 

II Final Rule (herein after referred to as the Rule) requires use of a comprehensive 

methodology to value fully the impacts of impingement and entrainment mortality at the 

San Onofre Nuclear Generating Station (SONGS). Other requirements for use of the test 

include: 

• A description of the methodology(ies) used to value commercial, recreational, 

and ecological benefits (including non-use benefits, if applicable); 

• Documentation of the basis for any assumptions and quantitative estimates. If 

the valuation includes use of an entrainment survival rate other than zero, a 

determination of entrainment survival at the facility based on a study approved 

by the NPDES permitting authority must be submitted; 

• An analysis of the effects of significant sources of uncertainty on the results of 

the study; 

• If requested by the NPDES permitting authority, a peer review of the items you 

submit in the Benefits Valuation Study. You must choose the peer reviewers in 

consultation with the Director who may consult with EPA and Federal, State, and 

Tribal fish and wildlife management agencies with responsibility for fish and 

wildlife potentially affected by your cooling water intake structure. Peer 

reviewers must have appropriate qualifications depending upon the materials to 

be reviewed. 

• A narrative description of any non-monetized benefits that would be realized at 

your site if you were to meet the applicable performance standards and a 

qualitative assessment of their magnitude and significance. 

All benefits, whether expressed qualitatively or quantitatively, should be addressed in the 

Benefits Valuation Study and considered by the NPDES permitting authority and in 

determining whether compliance costs significantly exceed benefits. 

The benefits assessment begins with an impingement and entrainment (IM&E) mortality 

study that quantifies both the baseline mortality as well as the expected change from rule 

compliance. Based on the information generated by the IM&E mortality studies, the 

benefits assessment includes a qualitative and/or quantitative description of the benefits 

that would be produced by compliance with the applicable performance standards at the 

facility site. To the extent feasible, dollar estimates of all significant benefits categories 

would be made using well-established and generally accepted valuation methodologies. 

In order to have the appropriate information if the benefit/cost option is chosen, we 

propose a strategy for the collection and analysis of economic information. The strategy 

is based on information obtained during the development of the Strategic Compliance 
B-2

Plan. It should be noted that one particular benefit category, benefits accruing to 

individuals even if they have no plans ever to use resources associated with SONGS 

(non-use benefits), are to be estimated only 

“In cases where the impingement or entrainment study identifies substantial harm

to a threatened or endangered species, to the sustainability of populations of 

important species of fish, shellfish or wildlife, or to the maintenance of community 

structure and function in a facility’s water body or watershed .“ (Final Rule, Federal 

Register page 41648). 

 

“Substantial harm” is a stringent requirement to necessitate estimation of non-use values 

and thus non-use values usually would not be included in the final analysis. However, 

because the Final Rule does raise the potential for estimation of non-use values, we do 

provide some contingency for their estimation. 

Description of Methodologies to Determine Benefits 

The 316(b) rule defines a performance standard that the EPA has established for all 

existing power plant facilities to meet. The SONGS station is located on the Pacific 

Ocean and therefore, it is subject to the impingement mortality (IM) performance 

standard (requiring a reduction in IM of 80% to 95%) and the entrainment (E) reduction 

performance standard (requiring a reduction in E of 60% to 90%). Recently, 

EPRIsolutions (2005) identified the lowest cost technology that would meet both the 

impingement and entrainment mortality performance standard. However, the Final Rule 

states that facilities do not have to meet the IM and E performance standard if it can be 

shown that the costs of achieving the performance standard are significantly greater than 

the benefits. Therefore we are providing a plan to collect information in case it is 

necessary to determine whether the benefits of the identified technology are significantly 

less than costs. 

Extensive long-term impingement studies, including impingement survival studies have 

been conducted at SONGS. Entrainment studies were conducted in 1979 and 1980. 

Based on the Strategic Plan, the potentially representative commercial and recreational 

species (RS) with impingement and entrainment mortality are likely white croaker, 

anchovy, and queenfish. If additional impingement and entrainment studies are done and 

these species continue to the RS, then there may be both commercial and recreational 

fisheries that benefit from reduced mortalities. It is also possible that non-use values will 

need to be addressed. 

The EPA examined a technology (closed-cycle cooling) to achieve a national standard for 

entrainment and impingement mortality. In determining benefits at a national level, EPA 

used certain economic concepts of benefits associated with using the assets that cooling 

water adversely effects and methodologies to estimate the benefits (U.S. EPA, 2004a; 

U.S. EPA 2004b; U.S. EPA 2004c). In order to make the benefits comparable to costs, 

they presented benefits in a monetary unit, dollars. Their benefit estimates reflected the 

willingness to pay of individuals to go from the current environmental status to one 
B-3

associated with an identified technology. All of the methods proposed in this PIC were 

also used in EPA’s national analysis. 

More specifically, this benefit analysis will seek to provide a unit value per fish caught 

($/fish) for recreational and commercial species affected by the new technology. With 

this information, total recreational and commercial benefits can be determined by 

multiplying the unit value times the expected increase in recreational and commercial 

catch arising from the identified technology. In addition, some information will be 

provided with respect to non-use values. 

Recreational Angling 

For the recreational anglers, there are two potential ways to proceed: 

1.) Benefit Transfer- the application of benefit estimates provided in other studies 

to the SONGS situation; 

2.) Primary research- collection and/or assemblage of data on recreational fishing 

on the Southern California area and using the data to derive an estimate of the 

value per fish for the important species. 

While the two approaches initially will be discussed independently, there is a sound 

reason to consider them in concert with one another. That is, the benefit transfer 

information provides a reality check for any values derived in the primary research. Any 

primary research effort should contain a thorough literature review, a component that 

would have information very similar in nature to the benefits transfer analysis. Also, the 

benefit transfer approach may provide a fallback position if the primary research is 

unsuccessful in providing benefit estimates. After both have been discussed 

independently, a strategy that integrates them will be offered. 

A Benefit Transfer Approach 

The use of benefit transfers requires finding a previous economic study (or studies) that 

considers a comparable situation to fishing near SONGS and contains dollar values per 

unit fish caught. Particularly important would be having species similar to the effected 

species and a fishing population similar to the SONGS situation. Although there are 

numerous other aspects of the fishing situation that might be important, these two are the 

most critical. 

In order to identify an appropriate study or studies, it would be essential to visit the site to 

examine first-hand the type of recreational fishing that is occurring. At the same time, 

contact with key people in the area will be made to determine if any relevant studies do 

exist (see references for some articles). We would consider it essential that the following 

sources be contacted or examined: 

1. State or Federal Hearings on previous SONGS station’s license renewal. 

2. State or Federal Hearings on previous power plant facilities in the general 

southern California area. 
B-4

3. Authors of EPA “in-house” studies associated with the Final Rule. In particular, 

EPA’s RUM analysis of the California region (U. S. EPA. 2004d) should be 

considered. 

4. Personnel from the National Marine Fisheries Service in La Jolla and California 

Fish and Game. 

5. Key Informants at universities or other research facilities 

a. University of California, San Diego 

Dr. Richard Carson (Department of Economics) is an expert in contingent 

valuation 

b. University of California, Berkeley 

Dr. Michael Hanneman (Department of Agricultural and Resource 

Economics) is an expert in economic valuation and has studied sportfishing in 

southern California 

c. University of California, Los Angeles 

Dr. Trudy Cameron is an expert in econometrics and has studied sportfishing 

in California. 

d. Southwest Fisheries Science Center, National Marine Fisheries Service 

Drs. Dale Squires and Sam Herrick are experts in fisheries economics and 

management. 

e. Local Consulting firms. Jones and Stokes Inc. (particularly Thomas Wegge) 

of Sacramento completed numerous sportfishing studies in California. 

6. Existing bibliography sources available by internet 

a. National Marine Fisheries Service, Southeast Fisheries Center 

b. Sportfishing Values Database 

c. Environmental Valuation Reference Inventory (EVRI): Canadian based. 

d. Beneficial Use Values Database (BUVD) 

e. Regulatory Economic Analysis Inventory, (REAI) maintained by the U.S. 

EPA 

f. ENVALUE, an environmental value database maintained in Australia. 

7. Investigation and Valuation of Fish Kills (American Fisheries Society, 1992) 

Excerpt: “Chapter 4 ("Monetary and Economic Valuation of Fish Kills") dates 

back to the Pollution Committee's Monetary Values of Fish booklets of 1970 and 

1975, which dealt with southern U.S. species. In 1978, the AFS North Central 

Division's Monetary Values of Fish Committee published Reimbursement Values 

for Fish, addressing species in 12 northern states and 2 Canadian provinces. To 

integrate these and other regional values, a special AFS Monetary Values of 

Freshwater Fish Committee collected values from 135 federal, state, provincial, 

and private agencies and hatcheries. These data were published in 1982 as Part I 

of AFS Special Publication 13. For the present book, the Socioeconomics Section 

has repeated the earlier survey to update replacement costs for killed fish and 

summarized procedures for estimating the broader economic losses resulting from 

a fish kill.” 

 

These potential sources will be used to obtain “off-the-shelf” values that could possibly 

be relevant to the effected species at the SONGS station. In addition, some of these 

contacts may be useful as researchers, data sources, and/or witnesses for any hearings 
B-5

that evolve. They may also be useful as peer reviewers or as sources to identify peer 

reviewers. 

Primary Research 

There are several other methodologies that could be used to obtain economic values for 

the species considered, but they will require some level of primary research. 

Data and programs could be obtained from the U.S. EPA and examined to see if the 

results reported in USEPA (2004d) are defensible. If they are not, a new RUM model 

could be estimated with the data. The major changes introduced in the research would be 

to consider:: 

1.) the RS species rather than in a grouping1

; 

2.) the San Onofre sites would be delineated rather that using Southern California 

counties as sites. 

The analysis would also update the angling activity and possible generalized the RUM 

model in ways that current research is including. 

 

Strategy to Obtain Recreational Unit Values per Fish Caught 

The initial portion of the study would be to complete a benefits transfer analysis and 

determine whether or not the values obtained were reasonable for the purposes of the 

decisions to be made. That is, if the mitigation strategy returned recreational benefits of 

$100,00 per year and the corresponding costs were $70,000, it would probably be unwise 

and inefficient to move onto primary research because in all likelihood the estimate of 

costs would not be significantly larger than the benefits. If however, the benefit transfer 

method suggested that the benefits were to be small relative to costs, it may be useful to 

do one of the primary research plans suggested in the previous section. The quality of 

existing studies would also be a determinant. 

Discussions with key informants in the benefit transfer work would determine the 

availability and reliability of data from the previous studies of recreational fishing. In 

addition, some notion of the potential improvement in estimates from using new data and 

a new model would be obtained. 

 

With this information and a better understanding on the costs of doing the primary 

research studies, decisions regarding what combination of benefit transfer and primary 

research would be most advantageous. The primary research would in all likelihood 

provide better estimates of value but may be more costly. Given the present information, 

it is likely that the analysis performed by the U.S. EPA in 2004 could be used. Additional 

effort would be devoted to determining whether the aggregation of sites and species 

could cause the estimated values to be biased. 

 

1

 For example, queenfish is considered in the category “bottomfish” in previous studies. If there were 

sufficient anglers targeting queenfish, then a category queenfish could be designated. 
B-6

Commercial Fishing 

The first determination would be whether commercial fishing is affected by reduced 

mortality to effected species. The National Marine Fisheries Service would be consulted 

regarding species that the impingement and entrainment studies identified. Both 

producers and consumers could gain from increases in commercial catch, but the 

assessment would likely only estimate the gains to direct producers, i.e. commercial 

fishermen. This is based on the expectation that relatively small changes in commercial 

landings result from reduced IM&E mortalities. This is the approach that EPA took in the 

2004 study. 

The approach that EPA uses for assessing commercial benefits to producers bases the 

unit value on the ex-vessel price (sometimes referred to as dockside price) of the species 

under consideration. The logic of the approach begins with an assumption that harvest 

increases do not induce effort (inputs used in harvesting) to increase following reductions 

of entrained and/or impinged organisms. If this were entirely true, then the ex-vessel 

price times the increase in quantity harvested would represent producers surplus. 

However, EPA appreciates that this would not likely be true and that effort and costs 

would undoubtedly increase in the long run in response to increased commercial profits 

(i.e. producer surplus). In the absence of property rights to the harvest, one would expect 

the producer surplus to be eliminated. Recognizing this and allowing for uncertainty in 

effort response, the EPA proposes using a range of 0-40% of the ex-vessel price times the 

increase in harvest as a measure of the increase in producers’ surplus. 

In the unlikely event that the change in landings would be relatively large and cause a 

change in commercial fisheries prices, we would need to collect information on 

commercial harvests and prices. There is not a good way to use benefit transfer methods 

for the consumers’ surplus although EPA is exploring one proposed by Bishop and Holt 

(2003). This approach at present does not look that promising. 

However, existing data from the National Marine Fisheries Service should be sufficient 

to estimate an inverse, general equilibrium demand curve (see Just, et al. for a 

description) for the species in question. With these estimates, the benefits to consumers 

could be calculated. 

Non-use Valuation 

Subsequent study by biologists will determine whether there is a necessity to assess nonuse values. Based on current knowledge, it does not appear necessary to estimate them. 

But, in the unlikely event that non-use values will have to be estimated, we would look to 

using a benefit transfer approach or doing primary research for SONGS. Based on the 

draft Strategic Compliance Plan, we do not believe that the magnitude of the non-use 

values would justify undertaking a primary research study for non-use values associated 

with the Potomac River station. 

Thus, if non-use values were needed, we would suggest using a benefit transfer method in 

all likelihood. There have not been any studies of non-use values associated with power 
B-7

plant activities per se. People have had to rely on studies associated with other types of 

activities. For example, EPA used a benefit transfers approach in their Proposal for the 

316(b) regulations and in the NODA. EPA (Tudor et al., 2003) reviewed numerous 

studies of use and nonuse values that were associated with surface water improvements 

(their Appendix A). Of those shown, only three address both changes in fish populations 

and non-use values associated with them (Huang, et al. 1997; Whitehead and Groothuis, 

1992; Olsen, et al. 1991). 

We propose considering these three studies in addition to doing a review of the recent 

literature. The recent literature may be important because EPA has placed some emphasis 

on this ecological valuation recently. For example, there is a meeting entitled “Improving 

the Valuation of Ecological Benefits, a STAR Progress Review Workshop” that was held 

in Washington in October, 2004. The papers presented at that workshop are now 

available on the internet. One of them is directly related to California. 

The results of this activity would likely be the development of a relationship (specifically 

a ratio) between use values and non-use values. For years, EPA used the 50% rule, a 

practice that implied that nonuse values were 50% of use values. Our approach, just like 

some of their 316(b) efforts (Tudor 2003), would be to refine this ratio for situations 

more akin to the changes associated with power plant operations. 

 

References 

Bishop, R. and M. Holt. 2003. “Estimating Post-Harvest Benefits from Increases in 

Commerciql Fish Catches with Implication for Remediation of Impingement and 

Entrainment Losses at Power Plants”. Unpublished Xerox. U. of Wisconsin-Madison. 10 

pp. 

EPRIsolutions. 2004. “San Onofre NuclearGenerating Station 316(b) Strategic 

Compliance Plan”, Draft Report, Palo Alto, CA. 55 pp. 

Hanemann, W. M., T. Wegge, and I. Strand. 1989. Development and Application of a 

Predictive Model to Analyze the Economic Effects of Species Availability. National 

Marine Fisheries Service, Southwest Region, Terminal Island CA. Admin. Rpt. SWR 89-

02. June. 

Huang, J. T. Haab, and J. Whitehead. 1997. “Willingness to Pay for Quality 

Improvements: Should Revealed and Stated Preference Data Be Combined?”, Journal of 

Environmental Economics and Management 34: 240-255. 

Just, R.E., D.L. Hueth, and A. Schmitz. 1984. “Applied Welfare Economics and Public 

Policy.” Englewood Cliffs, N.J.: Prentice-Hall, Inc. 

Kling, C. and C. Thomson. 1996. The Implications of Model Specification for Welfare 

Estimation in Nested Logit Models. Am. J. Agr. Econ. 78 (February):103-114. 
B-8

McConnell, K.E., Q. Weninger and I. Strand. "Joint Estimation of Contingent Valuation and 

Truncated Recreation Demands," Chapter in Valuing the Environment Using Recreation 

Demand Models (Eds. Kling and Herriges).Edward Elgar Publishers, Cheltenham, UK. 199-

216. 1999. 

Olsen, D., J. Richards, and R. Scott. 1991. “Existence and Sport Values for Doubling the 

Size of Columbia River Basin Salmon and Steelhead Runs”, Rivers 2(1): 44-51 

Thomson, C. and S. Crooke 1991. Results of the Southern California Economic 

Sportfishing Survey. NOAA Technical Memorandum, NMFS, Southwest Fisheries 

Center, August. 

Tudor, L., R. Wardwell, E.Besedin, and R. Johnston. 2003. Comparison of Non-use and 

Use Values from Surface Water Valuation Studies. Memo to the 316 (b) Record. Office 

of Water, USEPA. Washington, D.C. 

U. S. EPA. 2004a. “§316(b) Phase II Final Rule, Regional Studies, Part A: Evaluation 

Methods, Chapter A9: Benefit Categories and Valuation”. 

http://www.epa.gov/waterscience/316b/econbenefits/final.htm. 

U. S. EPA. 2004b. “§316(b) Phase II Final Rule, Regional Studies, Part A: Evaluation 

Methods, Chapter A10: Methods for Estimating Commercial Fishing Benefits”, 

http://www.epa.gov/waterscience/316b/econbenefits/final.htm. 

U. S. EPA. 2004c. “§316(b) Phase II Final Rule, Regional Studies, Part A: Evaluation 

Methods, Chapter A11:Estimating Benefits with a Random Utility Model”. 

http://www.epa.gov/waterscience/316b/econbenefits/final.htm. 

U. S. EPA. 2004d. “§316(b) Phase II Final Rule, Regional Studies, Part B: California 

Region, Chapter D4: RUM Analysis” 

http://www.epa.gov/waterscience/316b/econbenefits/final.htm. 

U. S. EPA. 2004e. “§316(b) Phase II Final Rule, Regional Studies, Part B: California 

Region, Chapter B3: Commercial Fishing Analysis” 

http://www.epa.gov/waterscience/316b/econbenefits/final.htm. 

Whitehead, J. and P. Groothuis. 1992. “Economic Benefits of Improved Water Quality: A 

Case Study of North Carolina’s Tar-Pamlico River”, River 3(3): 170-178. 

 
 Appendix

C WRITTEN FISH AND WILDLIFE AND OTHER 

REGULATORY AGENCY CORRESPONDENCE 

See following pages.