F I N A L R E P O R T

ADDENDUM TO

EVALUATION OF THE HARBOR

GENERATING STATION WITH RESPECT TO

THE CLEAN WATER ACT

SECTION 316(b) REQUIREMENTS

PROVIDING A CURRENT ASSESSMENT OF

ALTERNATIVE TECHNOLOGIES AND

OPERATIONAL MEASURES

Prepared by

Alden Research Laboratory, Inc.

EPRI

MBC Applied Environmental Sciences

Tenera Environmental, Inc.

URS Corporation

for

City of Los Angeles Department of Water and Power

111 N. Hope Street

Los Angeles, California 90012-2607

May 3, 2007
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

i

TABLE OF CONTENTS

SECTION PAGE

1.0 Introduction ....................................................................................... 1-1

2.0 Additional Information Currently Available ................................... 2-1

2.1 ADDITIONAL TECHNOLOGIES.................................................................................2-1

2.2 IMPINGEMENT MORTALITY AND ENTRAINMENT CHARACTERIZATION ...................2-2

2.3 COSTS ...................................................................................................................2-2

2.4 SECOND CIRCUIT COURT DECISION .......................................................................2-3

3.0 Entrainment Reduction Options....................................................... 3-1

3.1 FINE-MESH MODIFIED TRAVELING SCREENS..........................................................3-1

3.2 RETROFIT INTAKE WITH 0.5 MM WEDGEWIRE SCREENS .........................................3-3

3.3 FLOW REDUCTION .................................................................................................3-3

3.4 CLOSED-CYCLE COOLING ......................................................................................3-4

3.5 ADDITIONAL TECHNOLOGIES.................................................................................3-4

4.0 Impingement Mortality Reduction Options..................................... 4-1

4.1 COARSE-MESH MODIFIED TRAVELING SCREENS ....................................................4-1

4.2 WIDE-SLOT CYLINDRICAL WEDGEWIRE SCREENS..................................................4-1

4.3 FLOW REDUCTION .................................................................................................4-2

4.4 CLOSED-CYCLE COOLING......................................................................................4-2

4.5 ADDITIONAL IMPINGEMENT REDUCING TECHNOLOGIES ........................................4-2

5.0 Cost Update........................................................................................ 5-1

6.0 Data Gaps and Uncertainties ............................................................ 6-1

7.0 Conclusions ........................................................................................ 7-1

LIST OF TABLES

TABLE 2-1. PERTINENT PROJECT DATA (REVISED TABLE 2-1 FROM THE INITIAL

REPORT)................................................................................................................................2-5

TABLE 2-2. REVISED TABLE 2-3 FROM THE INITIAL EVALUATION –

COMPARISON OF PERCENT COMPOSITION OF ENTRAINED LARVAE

LENGTHS COLLECTED AT HGS ........................................................................................2-7

TABLE 2-3. INITIAL SCREENING OF FISH PROTECTION ALTERNATIVES AT HGS

(REVISED TABLE 3-1 FROM THE INITIAL EVALUATION).............................................2-8

TABLE 3-1. PREDICTED HEAD CAPSULE DEPTH (HCD) FOR LARVAE COLLECTED

AT HGS.................................................................................................................................3-1

TABLE 5-1.ALDEN’SAPPRAISAL LEVEL COSTS OF EVALUATED ALTERNATIVES......5-2

TABLE 6-1. ALTERNATIVE DATA GAPS AND UNCERTAINTIES ........................................6-1

TABLE B-1. QUALITATIVE RANKING, WITH 1 BEING LOWEST AND 5 BEING

HIGHEST, OF POTENTIAL RESTORATION PROJECTS FOR OFFSETTING

HARBOR GENERATING STATION IM&E LOSSES. ...........................................................12
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

ii

LIST OF ATTACHMENTS

ATTACHMENT A - SUMMARY OF 2004 EVALUATION OF HGS

ATTACHMENT B - LADWP RESTORATION OPTIONS

ATTACHMENT C - VELOCITY CALCULATIONS

ATTACHMENT D - FISH MORPHOMETRY AND SCREEN MESH HEADLOSS

ATTACHMENT E - POTENTIAL FISH RETURN CLEANING SYSTEMS
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

iii

LIST OF ACRONYMS

AFB Aquatic Filter Barrier

BTA Best Technology Available

cfs cubic feet per second

CWIS cooling water intake system

DOC Debris and Organism Collection

EPA U.S. Environmental Protection Agency

EPRI Electric Power Research Institute

ft/sec feet per second

FPS Fish Protection System

gpm gallons per minute

HCD head capsule depth

HGS Harbor Generating Station

ILAH Inner Los Angeles Harbor

IM&E Impingement Mortality and Entrainment

LADWP Los Angeles Department of Water and Power

MIS Modular Inclined Screens

mm millimeter

MW megawatts

MWh megawatt hour

NOAA National Oceanic and Atmospheric Administration

O&M Operating and Maintenance

VSD Variable Speed Drives
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

1-1

1.0 INTRODUCTION

In December 2004, Alden Research Laboratory, Inc. (Alden), under contract to the Electric Power

Research Institute (EPRI), developedareportentitled“EvaluationoftheHarborGeneratingStation

withrespecttotheEnvironmentalProtectionAgency’s316(b)RulesforExistingFacilities”forthe

Los Angeles Department of Water and Power (LADWP). This report provided an assessment of the

universe of technologies available for consideration for fish protection at steam generating stations

and resulted in a limited number of technologies and operational measures that were considered

appropriate for the Harbor Generating Station (HGS). A summary of the results of the 2004

evaluation is provided in Attachment A.

HGS is subject to both the impingement mortality and entrainment (IM&E) reduction performance

standards. However, only technologies that would reduce both IM&E were evaluated for this

addendum. Technologies that would only reduce impingement were not evaluated as the layout of

the HGS Cooling Water Intake System (CWIS) is such that the cost of impingement mortality only

technologies would be similar to IM&E technologies.

The technologies evaluated in the initial detailed investigation fall into four categories: physical

barriers; collection systems; diversion systems; and, behavioral barriers. Diversion systems and

behavioral barriers require the ability of the organisms to swim away. Entrainable organisms lack the

sustained swimming ability to respond effectively to these systems; therefore, they were eliminated

from consideration to meet the entrainment reduction standard. Two technologies (i.e. fine-mesh

Ristroph traveling screens and cylindrical wedgewire screens) were considered as entrainment and

entrainment/impingement reducing options at HGS.

As discussed below, more current information allows for re-consideration of the previously evaluated

technologies and operational measures, and the consideration of technologies whose status has

changed since the 2004 report. This report will serve as an addendum to the 2004 report. An update

to the restoration evaluation is provided in Attachment B. To develop this addendum, Alden

consulted with EPRI, MBC Applied Environmental (MBC), Tenera Environmental, Inc. (Tenera) and

URS Corporation (URS).
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-1

2.0 ADDITIONAL INFORMATION CURRENTLY AVAILABLE

The following new informationhasbeenassessedasitrelatestoAlden’soriginalevaluation:

 Additional technologies have become available;

 LADWP has completed a one-year IM&E study;

 Costs can be updated to 2006 values; and

 The Second Circuit Court (Court) issued a decision (Decision) on various components of

the Phase II Rule.

Table 2-1 is a revised and updated version of Table 2-1 in the initial report. This table reflects

updated knowledge of the facility. Also, velocity calculations are provided in Attachment C.

A discussion of the impacts of these new data on the alternatives previously evaluated and additional

alternatives that are available for HGS is presented in the following sections.

2.1 ADDITIONAL TECHNOLOGIES

In the 2004 report, there were four technologies characterizedas“emergingtechnologies”:

 Beaudrey’sFishProtectionSystem(FPS);

 Filtrex Filter Candles;

 Debris and Organism Collector (DOC); and

 Geiger’sMulti-Disc Screening System.

Currently, the Filtrex Filter Candles have not been tested and research on the DOC was discontinued

after limited laboratory testing. The original FPS has also not been tested. However, a variation of

the original system, whichutilizescircularrotatingscreenswithafish“scoop,”hasbeeninstalledat

one facility and is currently being tested. Therefore, there is no new information to assess the

feasibility, cost, or effectiveness of these three technologies at this time.

The multi-disc screens with fish protection features (for impingement) have been installed at two

facilities. The first installation was at the Potomac Generating Station and was the subject of a oneyear EPRI study. The preliminary results have been positive and it appears this technology has the

potential to match the impingement mortality reduction results from Ristroph screens. In addition,

this technology provides the benefit of eliminating carryover. The second installation was in late

2006 at the Salem Generating Station on the Delaware River and no data are available at this time.

Another emerging technology with fish protection features, not available in 2004, is a plastic belt

screen manufactured by Hydrolox. These screens are lighter and potentially less costly to install and

operate than other traveling screens. The plastic belt screens are new and do not have any long-term

operational data, but pilot studies currently planned at one estuarine site on Long Island, NY should

provide useful information on biological efficacy and operational issues. Because of the material

used and way that the screen is constructed, the smallest mesh size available is 1.75 millimeters (mm

)atthistime.Thus,thistechnologyhasthesame“limitation”astheModularInclinedScreensystem

(MIS) in excluding only larger entrained organisms and, therefore, would not meet entrainment

performance standards for HGS.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-2

Two new currently available screening technologies (i.e. Hydrolox and Geiger screens) can be

consideredinthesamecategoryasRistrophscreens.Bothofthesesystemsfunctiononthe“trapand

transfer”concept and require the same type of fish and debris returns as Ristroph screens. The

modified traveling water screen discussions in Sections 3 and 4 apply to all three of these

technologies.

Currently, an EPRI-funded laboratory study is under way to determine the survival of entrainablesized organisms impinged on fine-mesh traveling screens.

The testing is being conducted in the recently refurbished large, fish testing facility at Alden.

Modifications to this facility were made to allow for installation of three test screens the Geiger

Multi-Disc Screen (0.5 mm), a Brackett-Green through-flow screen (0.5 mm), and a Hydrolox screen

(1.0 mm).

Parameters to be evaluated include:

 Two approach velocities (0.5 and 1.0 ft/sec)

 Two durations of impingement (4 and 8 minutes)

 Two freshwater species with divergent morphologies, which allows them to be tested at the

same time.

 Three length classes

 Three treatment replicates and two handling control replicates run on each testing day.

2.2 IMPINGEMENT MORTALITY AND ENTRAINMENT CHARACTERIZATION

The relative contribution of the most abundant species impinged has varied greatly from 1978/1979 to

2006. Prominent species impinged in 2006, but not in 1978/1979, include round stingray, black

perch, barred sand bass, giant kelpfish, spotted kelpfish, and white seaperch. These impingement data

donotchangeAlden’sselectionofappropriatetechnologies for consideration at HGS.

As expected, the entrainment data showed similar results. Gobies, blennies, silversides, white

croaker, and northern anchovy are abundant species entrained. Of most interest were the results of

the entrainment life history characterization. The 2006 results confirmed the 1978/1979 results and

documented that 97-100% (depending on species) of entrainedorganismswere“pre-transformation”

stage. That is, the vast majority of entrained fish were less than 12 mm in length. The lengths of

larvae collected in 2006 are provided in Table 2-2. This table replaces Table 2-8 in the initial

evaluation.

These resultsdonotalterAlden’sselectionofappropriatetechnologiesforconsideration in reducing

entrainment at HGS. As discussed in Section 3, the overall efficacy of any entrainment reduction

technology is mitigated by the predominance of such early life history stages.

2.3 COSTS

Alden has revised and included in Section 5 of this Addendum Table 5-1 (i.e., Table 6-3 from 2004

report) to reflect current (2006) costs of appropriate technologies. An adjustment factor of 1.121 was

used to account for inflation and the price per megawatt hour (MWh) was increased from $40/MWh

1 Based on consumer price index from 2002 through 2006.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-3

to $50/MWh2. For technologies that were evaluated further in this Addendum, the costs presented in

Table 5-1 have been modified to reflect the updated evaluations.

2.4 SECOND CIRCUIT COURT DECISION

The Court issued its Decision on the Phase II Rule on January 27, 2007. This Decision had

significant impacts on the compliance alternatives and options discussed in the 2004 Report. The

major components of the Decision are:

 The Court determined that two options, use of Restoration Measures and the Cost-Benefit

Test, are unlawful and cannot be used for compliance;

 The Court remanded to U.S. Environmental Protection Agency (EPA) the determination of

Best Technology Available (BTA); and

 The Court also remanded to EPA the Cost-Cost Test and Technology Installation and

OperationPlanduetoEPA’sfailuretoprovideadequateopportunityforpublicreviewand

comment for these two provisions.

The remand of the BTA determination introduces some uncertainty in the analysis, since the nature of

the technologies and performance standards could change as a result of EPA revisions to the Rule.

One of the key issues EPA is required to address is whether or not use of wet or dry closed-cycle

cooling is BTA. The Court said EPA could consider three factors in this evaluation. The first is cost,

but only in a limited manner. To reject closed-cycle cooling from a cost standpoint, EPA must

determine that the industry cannot reasonably bear the cost of a national retrofit with these

technologies. The two other factors EPA may consider are adverse environmental impacts associated

with closed-cycle cooling and impacts to energy production and efficiency.

A second major component of the Decision is a requirement to usethe“bestperforming”technology.

TheCourtdeterminedthatifEPAchosetouseperformancestandardranges,afacility’sdecision

could no longer be based on which technology was most cost-effective. Rather,the“best

performing”technologyintheappropriate performance standard range must be used. The Court did

saythatalesscostlytechnologythanthe“bestperforming”technologycouldbeusedifitworksas

leastaswellasthelowendoftheperformancerangeofthe“bestperformer.”

The result of the Decision is that HGS will be limited to use of technologies and/or operational

measures for compliance. Use of the Cost-Cost Test may be available if it is proposed for public

review and comment. However, there is some risk that EPA could alter Appendix A costs and/or

implementation provisions in the revised Rule.

Subsequent to the Decision, EPA has suspended the Rule. EPA did not budget for a major 316(b)

rulemaking in 2007, so it is not clear when a revised Phase II Rule would become effective. The

result is uncertainty as to when compliance will be required. EPA has reverted to issuing §316(b)

requirementson“BestProfessionalJudgment”(BPJ)basis.ThiswastheapproachEPAusedpriorto

promulgation of the Phase II Rule. Given California’sadvocacyon316(b)issues,thishaslittleeffect

onLADWP’sfacilities.Thesuspensionofthescheduleallowsadditionaltimetoconductpilot

studiestoidentifythe“bestperforming”technologyforHGS.

2 Based on average annual day ahead prices for 2006 using SP-15 CAISO real-time data.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-4

As in 2004, fish protection technologies were considered to have potential for application at HGS if:

 The technology has proven biological effectiveness;

 The technology is available and does not require further engineering development; and

 The technology has engineering and/or biological advantages over the other technologies we

evaluated.

Table 2-3 is a revision to Table 3-1 from the initial evaluation.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-5

TABLE 2-1. PERTINENT PROJECT DATA (REVISED TABLE 2-1 FROM THE INITIAL REPORT)

Location

161 Island Ave, Wilmington CA, 90774

Latitude: 33.7672° N

Longitude: 118.2661° W

Waterbody: Inner Los Angeles Harbor (ILAH)

Waterbody Type: Embayment

EPA ID #: DUT1138

NPDES ID #: CA0000361

Permit Expiration Date: June 10, 2008

Estimated project intake flow

Maximum: 167 cfs (75,000 gpm)

Minimum: 83.5 cfs (37,500 gpm)

Plant Design: 167 cfs (75,000 gpm)

Intake velocities: (approach)

One Pump

Trash racks: 0.2 ft/sec

Traveling water screen: 0.4 ft/sec (2 screens in operation)

Traveling water screen: 0.2 ft/sec (4 screens in operation)

Two Pumps

Trash racks: 0.3 ft/sec

Traveling water screen: 0.8 ft/sec (2 screens in operation)

Traveling water screen: 0.4 ft/sec (4 screens in operation)

Water Level

Elevations

HWL: El. 7.5 ft

MLLW: El. 0.0 ft

LWL: El. -1.7 ft

MSL: El. 2.9 ft

Water Depths

In front of CWIS

Maximum: 42.5ft

Minimum: 33.3ft

MMLW: 35 ft

MLS: 37.9 ft

Other information: all elevations refer to mean sea level

Project Structures

CWIS

Location: Slip 5 L.A. Harbor

Configuration: along shoreline

Length: 56 ft

Invert at face: El. -21.0 ft.

Top: El: -11.0 ft

Trash rack location: face of intake

Trash rack material: 3/8 in. x 3 in. bars

Trash rack spacing: 4.5 in. on-center

Trash rack cleaning: weekly or when needed
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-6

Table 2-1. Continued

Intake Pipes

Number: 2

Length: 1,095 ft

Inner diameter: 8 ft

Invert: El. -20.0 ft (CWIS)

Invert: El. -16.0 ft ( screenhouse)

Screenhouse

Location: about 33.5 ft downstream of intake pipes

Number of bays: 6

Bay width: 7.9 ft

Invert: El. -16.0 ft

Top of structure: El. 12.0 ft

Other info: 2 bays permanently blocked, 2 bays are temporarily blocked and 2 bays are

used during normal operations.

Traveling water screens

Location: screenhouse

Number: 4 (only 2 operational)

Width: 6.2 ft

Mesh material: bronze

Mesh size and geometry: 3/8 in. up to 5/8 in. sq. mesh

Spray nozzle configuration: back wash

Spray pressure: 70 psig

Spray volume: 800 gpm (2 pumps at 400 gpm)

Operation: rotated for 30 minutes every 8 hour shift

Debris/fish return: rectangular trough

Trough discharge: back into the ILAH

Circulating water pumps

Number of pumps: 2

Types of pumps: vertical, single-speed, mixed-flow

Pump inlet: El. -14.5 ft

Invert: -19.0 ft

Rating: 305 hp @ 514 rpm

Flow per pump: 83.5 cfs (37,500 gpm)

Flow with both pumps operating: 167 cfs (75,000 gpm)

Cooling water discharge

Location of discharge: cooling water is transported through a 1,393 ft long pipe to the

dischargestructureinL.A.Harbor’sWestBasin,preventingrecirculation.

Power Generation

Fuel type: gas

Facility output

Units 1&2: 80 MW (each)

Unit 5: 75 MW

Unit 10-14: 43 MW (each)

Facility total: 450 MW

Operating mode: peaking

Plant capacity factor:

Unit 5: 23% (2001-2005)

Average annual energy: 144,998 MWh (net) (2001-2005) (Unit 5)
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-7

TABLE 2-2. REVISED TABLE 2-3 FROM THE INITIAL EVALUATION –COMPARISON OF PERCENT

COMPOSITION OF ENTRAINED LARVAE LENGTHS COLLECTED AT HGS

Percent Composition*

Species

2006

Entrainment 0-5mm 5-10mm 10-15mm >15mm

anchovy 1% 19% / 3% 28%/ 25% 33% / 42% 20% / 30%

gobies 81% 86% / 83% 7% / 17% 7% / -- <1% / --

blenny 3% 100% / 100% <1% / <1% -- / -- -- / --

white

croaker 13% 97% / 96% 2% / 4% 1% / -- -- / --

* (1981 / 2007)

References: Intersea Research Corporation (IRG), Harbor Generating Station Cooling Water

Intake Study 316(b) Demonstration Program 1978-1979. (1981) Tenera Environmental, IM&E

Characterization Study Preliminary Results 2006, unpublished. (2007)
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-8

TABLE 2-3. INITIAL SCREENING OF FISH PROTECTION ALTERNATIVES AT HGS (REVISED TABLE 3-1 FROM THE INITIAL EVALUATION)

Concept

Biological

Effectiveness

Proven

Engineering

Alternative

Available

Advantages

over Other

Concepts

Potential for

Application

at HGS

Comments

Behavioral Barriers

Sound yes yes no no The focus of recent fish protection studies

involving underwater sound technologies has

been on the use of new types of low and high

frequency acoustic systems that have not

previously been available for commercial use.

Sound devices are not appropriate for

entrainment reduction as the early life stages

have not yet developed hearing capabilities or

have insufficient swimming capability to avoid

entrainment.

Infrasound no yes yes no There was a general belief in the scientific

community that infrasound could represent an

effective fish repellent since there was a

physiological basis for understanding the

response of fish to particle motion. Sound

devices are not appropriate for entrainment

reduction as the early life stages have not yet

developed hearing capabilities or have

insufficient swimming capability to avoid

entrainment.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-9

TABLE 2-3. INITIAL SCREENING OF FISH PROTECTION ALTERNATIVES AT HGS (REVISED TABLE 3-1 FROM THE INITIAL EVALUATION)

Concept

Biological

Effectiveness

Proven

Engineering

Alternative

Available

Advantages

over Other

Concepts

Potential for

Application

at HGS

Comments

Strobe lights yes yes no no Although many studies have evaluated strobe

lights as a primary barrier system, strobes are

often evaluated as part of an integrated fish

protection and passage system that includes

other devices such as screens, narrow-spaced

bar racks, bypasses, and/or other behavioral

systems. As a secondary system, strobe lights

have the potential to incrementally increase fish

protection effectiveness. However, they are not

effective with larval fish that have little or no

motility.

Mercury lights no yes yes no Response to mercury light has been shown to

be species-specific; some fish species are

attracted, others repelled, and others have

demonstrated no obvious response. However,

they are not effective with larval fish that have

little or no motility.

Chemicals no no no no Use of chemicals has been suggested, and in

some cases evaluated, as fish protection

measures. However, no practical application of

these devices has been developed, and they are

not considered available technologies for

application at CWISs.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-10

TABLE 2-3. INITIAL SCREENING OF FISH PROTECTION ALTERNATIVES AT HGS (REVISED TABLE 3-1 FROM THE INITIAL EVALUATION)

Concept

Biological

Effectiveness

Proven

Engineering

Alternative

Available

Advantages

over Other

Concepts

Potential for

Application

at HGS

Comments

Electric screens no yes no no Electric barriers have been shown to effectively

prevent the upstream passage of fish. However,

attempts to divert or deter the downstream

movement of fish have met with limited success.

Consequently, past evaluations have not led to

permanent applications. The potential

effectiveness of these barriers for application at

CWISs is unknown. Given their past

ineffectiveness and hazard potential, electric

screens are not considered a viable technology

for application at CWISs. As with other

behavioral barriers, electric barriers would not be

effective with larval fish that have little or no

motility.

Air bubble curtain yes yes no no These curtains generally have been ineffective

in blocking or diverting fish in a variety of field

applications. Air bubble curtains have been

evaluated at number of sites on the Great Lakes

with a variety of species. All air bubble curtains

at these sites have been removed from service.

Air bubble curtains would not be effective with

larval fish that have little or no motility.

Water jet curtain no yes no no Devices such as water jet curtains have been

suggested, and in some cases evaluated, as fish

protection measures. However, no practical

application of these devices has been

developed, and they are not considered

available technologies for application at CWISs.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-11

TABLE 2-3. INITIAL SCREENING OF FISH PROTECTION ALTERNATIVES AT HGS (REVISED TABLE 3-1 FROM THE INITIAL EVALUATION)

Concept

Biological

Effectiveness

Proven

Engineering

Alternative

Available

Advantages

over Other

Concepts

Potential for

Application

at HGS

Comments

Hanging chains no yes no no Devices such as hanging chains have been

suggested, and in some cases evaluated, as fish

protection measures. However, no practical

application of these devices has been

developed, and they are not considered

available technologies for application at CWISs.

In addition, they are not effective with larval fish

that have little or no motility.

Visual keys no yes no no Visual cues have been suggested, and in some

cases evaluated, as fish protection measures.

However, no practical application of these

devices has been developed, and they are not

considered available technologies for application

at CWISs.

Hybrid barriers (e.g.,

strobe light /air bubble

curtain)

no no no no No practical application of these devices has

been developed, and they are not considered

available technologies for application at CWISs.

In addition, they are not effective with larval fish

that have little or no motility.

Physical Barriers

Fixed screens yes yes no no As a barrier device, a fixed screen can only be

effective if there is a low through-screen velocity

and a way for fish to escape the CWIS. Finemesh devices would be required for entrainment

reduction. These early life history stages have

limited motility which further reduces the

potential for protection for this technology.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-12

TABLE 2-3. INITIAL SCREENING OF FISH PROTECTION ALTERNATIVES AT HGS (REVISED TABLE 3-1 FROM THE INITIAL EVALUATION)

Concept

Biological

Effectiveness

Proven

Engineering

Alternative

Available

Advantages

over Other

Concepts

Potential for

Application

at HGS

Comments

Conventional traveling

water screens

yes yes no no As barrier devices, traveling screens cannot be

considered for protection of early life stages or

aquatic organisms that have little or no motility.

Rotary drum screens yes yes no no Installation of rotary drum screens would require

a much larger area than conventional traveling

screens because of the lower design velocity.

Barrier net yes yes no no Barrier nets can be considered a viable option

for protecting adult fish provided that relatively

low velocities (generally less than 1 feet/sec)

can be achieved and debris loading is light.

They would be ineffective with early life history

stages that have little or no motility.

Bar rack barrier yes yes no no Bar rack barriers are typically designed to have

spacing greater than 1 inch and would not

effectively prevent the entrainment of early life

stages. They may, however, effectively reduce

impingement.

Infiltration intakes yes yes no no Radial wells and artificial filter beds have been

successfully used to supply small quantities of

water. While such systems have little if any

biological impact, they have not been developed

for screening large flow volumes or for CWIS

application.

Porous dike yes yes no no Rock structures such as rock cribs and porous

dikes allow water to pass while preventing

passage of juvenile and adult fish. Their

effectiveness with larval fish is unknown.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-13

TABLE 2-3. INITIAL SCREENING OF FISH PROTECTION ALTERNATIVES AT HGS (REVISED TABLE 3-1 FROM THE INITIAL EVALUATION)

Concept

Biological

Effectiveness

Proven

Engineering

Alternative

Available

Advantages

over Other

Concepts

Potential for

Application

at HGS

Comments

Aquatic filter barrier

(AFB)

yes yes no no At this time, the AFB system is considered to be

experimental despite its potential biological

effectiveness. In addition, the space required for

installation of this technology is not available at

HGS.

Cylindrical wedgewire

screen intakes

yes yes yes yes Wedgewire screens have the potential to reduce

both entrainment and impingement at water

intakes. Effectiveness is based on the slot size,

through-slot velocity, and presence of an

ambient cross-current to carry organisms and

debris away.

Collection Systems

Modified traveling

(Ristroph-type)

screens (coarse- and

fine-mesh) with fish

protection features

yes yes yes yes Modified traveling water screens continue to be

an available technology that can reduce fish

losses due to impingement and entrainment.

The primary concern with fine-mesh screens is

that they function by impinging early organism

life stages that are entrained through coarsemesh screens. Depending on species and life

stage, mortality from impingement can exceed

entrainment mortality. Biofouling potential must

also be considered.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-14

TABLE 2-3. INITIAL SCREENING OF FISH PROTECTION ALTERNATIVES AT HGS (REVISED TABLE 3-1 FROM THE INITIAL EVALUATION)

Concept

Biological

Effectiveness

Proven

Engineering

Alternative

Available

Advantages

over Other

Concepts

Potential for

Application

at HGS

Comments

Fish pumps yes yes no no Hidrostal and Archimedes screw pumps have

demonstrated an ability to transfer adult fish with

little or no mortality. These pumps by

themselves do not represent a technology for

protecting fish. However, when coupled with fish

bypass systems such as angled screens and

louvers, fish pumps are biologically effective.

The effect of the pumps on larval fish would

need to be evaluated.

Diversion Systems

Louvers / angled bar

racks

yes yes no no Due to the large spacing of the louver slats,

louver systems do not protect early life stages of

fish.

Angled screens (fixed

or traveling)

yes yes no no Angled screens can be considered a viable

option for protecting juvenile and adult life

stages provided that proper hydraulic conditions

can be maintained and debris can be effectively

removed. Fish eggs, larvae, and small

invertebrates would not be protected by angled

screens unless fine-mesh screening was used.

Also, as the length of screen increases the

survival of larvae decreases. Guidance

efficiency improves as fish grow.

Angled rotary drum

screens

yes yes no no Installation of angled rotary drum screens would

require an even larger area than “conventional”

rotary drum screens.

Inclined plane screens no yes no no No advantage over MIS at HGS.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-15

TABLE 2-3. INITIAL SCREENING OF FISH PROTECTION ALTERNATIVES AT HGS (REVISED TABLE 3-1 FROM THE INITIAL EVALUATION)

Concept

Biological

Effectiveness

Proven

Engineering

Alternative

Available

Advantages

over Other

Concepts

Potential for

Application

at HGS

Comments

Eicher screen yes yes no no While biologically effective, the Eicher screen

was designed for penstock and pipes. There is

no advantage over an MIS at HGS.

Modular inclined

screens (MIS)

yes yes no no The combined results of laboratory and field

evaluations of the MIS have demonstrated that

this screen is an effective fish diversion device

that has the potential for protecting fish at water

intakes. Any consideration of the MIS for CWIS

application should be based on future largescale, prototype evaluations. Due to the slot

size (2.0 mm) some reduction in entrainment

can be expected.

Submerged traveling

screens

no yes no no Designed for partial screening of hydroelectric

project intakes. Not applicable to HGS.

Modifications to Reduce Intake Flow

Modified pump

operation

yes yes no no Reducing flow will reduce impingement and

entrainment. Flow reduction could be

accomplished by either turning pumps on and off

or with the installation of VSDs to follow the load

(see below). HGS has only one unit that uses

once-through cooling. This unit operated off the

waste heat from two other units, therefore

reducing the output of Unit 5 would reduce the

output of the two associated units.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2-16

TABLE 2-3. INITIAL SCREENING OF FISH PROTECTION ALTERNATIVES AT HGS (REVISED TABLE 3-1 FROM THE INITIAL EVALUATION)

Concept

Biological

Effectiveness

Proven

Engineering

Alternative

Available

Advantages

over Other

Concepts

Potential for

Application

at HGS

Comments

Install VSDs yes yes no no Due to the existing low velocities within the HGS

CWIS, VSDs would not provide any additional

benefit by reducing the intake velocity. Some

reduction in entrainment could be achieved with

VFDs as a result of reduced intake volume.

Install closed-cycle

cooling system

(mechanical, natural

draft and dry cooling

towers)

yes yes yes yes Closed-cycle cooling will reduce flow

significantly. Depending on the type of closedcycle system installed and the maximum number

of cycles-of-concentration, circulating water flow

in salt water could be reduced 73-98 percent.

Impingement and entrainment would be reduced

accordingly.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

3-1

3.0 ENTRAINMENT REDUCTION OPTIONS

As stated previously, compliance with EPA’sentrainmentreductionperformancestandardswillbe

difficult for marine facilities. Closed-cycle cooling or dramatic reductions in cooling water flow by

limiting station operations are extreme and costly measures. There are limited technologies that can

be considered for reducing entrainment and even more limited information of the efficacy of these

technologies with West Coast marine or estuarine species.

Fine-mesh traveling screens (e.g., Ristroph-type, Hydrolox, or Geiger) have potential for application

at HGS. There are currently no additional data available on the effectiveness of these screens in

reducing mortality of entrainable organisms.

3.1 FINE-MESH MODIFIED TRAVELING SCREENS

Alden’soriginalevaluationreflectedanapproachvelocityof0.2feet per second (ft/sec). The actual

velocity is about 0.8 ft/sec as only two of the six screenbays are in operation. With 4 traveling water

screens in operation, this velocity is reduced to about 0.4 ft/sec. This velocity falls within the range

that Alden uses to design fine-mesh fish protection screens, therefore the fine-mesh Ristroph screen

option as described in the 2004 evaluation will not change.

Due to the layout of the screenbays and the location of the circulating water pumps, there may not be

balanced flow through the fine-mesh screens. This could lead to excessive fouling of the higher

velocity screens and result in lower survival of entrained organisms. To reduce this potential,

LADWP should consider having a hydraulic model developed.

Having reviewed the 2006 entrainment characterization study results for HGS, Alden now believes

that survival of the earliest life history stages of fish entrained at HGS will be negligible. These life

stages dominate the entrainment numbers and, therefore, this technology would probably not meet the

entrainment reduction standard. However, Alden recommends that pilot studies be conducted if

LADWP wants to consider this technology further. The pilot study proposed for HGS would identify

where survival of previously entrained organisms starts to occur.

LADWP has requested a prediction of the size mesh required to effectively exclude larval fish at

HGS. The key factor in exclusion of aquatic organisms is the maximum dimension of the organism.

Typically, head capsule depth (HCD) is selected as it is the earliest-developed, non-compressible

body part. Unfortunately, Alden could not find adequate data on the West Coast species of interest at

HGS to develop the necessary analyses. However, adequate data have been developed for East Coast

species. Based on discussions among Alden and MBC staff, the following surrogates were used for

this assessment:

TABLE 3-1. PREDICTED HEAD CAPSULE DEPTH (HCD) FOR LARVAE COLLECTED AT HGS

West Coast Species Length at hatch

(mm) East Coast Species Predicted HCD(mm)

Gobiidae 2.7-3.2 Naked goby 0.56

Hypsoblennius 2.0 Atlantic menhaden 0.83

California halibut 1.6-2.1 Bay anchovy 0.30

White croaker 2.2-2.8 Bay anchovy 0.37

Northern anchovy 2.5-3.0 Bay anchovy 0.34
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

3-2

The data used for this assessment are provided in Attachment D. Based on the above information, a

nominal mesh size of 0.3 mm would be required to exclude California halibut yolk-sac larvae.

However, to be conservative, a 0.2 mm mesh screen was selected to exclude larvae found at HGS.

Based on information provided by screen manufacturers, a screen with a mesh/slot size of 0.2 mm can

be provided. Engineering data on the various meshes are provided in Attachment A. The following

design considerations are associated with the replacement of the existing 9.5 mm mesh screens with

0.2 mm screens:

 Increase head loss –Head loss will increase from 0.2 to 5 inches in a clean condition, and 2 to

24 inches at 50% blocked with debris.

 Screen rotation speed –Screens should be designed to operate continuously with a high

rotation speed to remove debris quickly. The debris loading will increase from current

conditions due to the smaller opening.

 Screen mesh –A 0.2 mm screen mesh will require a 1-inch backup mesh for added strength.

The wire diameter of a 0.2 mm square mesh screen is only 0.2 mm and could easily be

damaged by large debris. More frequent screen replacement is expected.

 Pre-screening –Pre-screening devices are recommended to reduce potential damage and to

reduce the debris loading at the screens. A fine-bar rack or bar screen with a 1⁄2- to 1-inch

spacing and/or a 3/8-inch traveling water screen may be required upstream of the fine-mesh

screen installation.

To prevent reimpingement of the fish and debris, the return would need to be routed along the discharge

pipe. As a result, organisms collected from the screens will have to be transported about 1,400 feet

through a return pipe. In addition, fish and shellfish species and their associated life stages tend to

vary considerably in terms of their ability to tolerate the collection and handling associated with this

option, which emphasizes the need for species and life stage specific testing to verify survival rates.

Alden believes that there are methods for maintaining a clean fish return system. A review and

comparison of two potential fish return cleaning systems is provided in Attachment E.

Finally, concern has been expressed with biofouling of the exposed (above water surface) screening

components during continuous operation of the screen. Although this may be a valid concern, an

assessment could easily be performed during a pilot study. Development of a fouling control

technology could be a component of the pilot study. However, rather than confound the biological

assessment component of the study, it may be desirable to conduct a small-scale, focused study for

evaluating biofouling conditions. Costs for this component of a pilot study have not been developed.

Conclusion

Fine-mesh traveling screens are technicallyan“exclusiontechnology”thatutilizesa“trapand

transfer”concept.Theprocessofcollectingorganismstoassesssurvivalimpartssomelevelof

mortality, which is difficult to ascertain in the field. Consequently, the projected efficacy of this

technology will be less than that for other exclusion technologies that do not collect the organisms.

The life stages that dominate the entrainment numbers at HGS are such that this technology would

probably not meet the entrainment reduction standard.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

3-3

3.2 RETROFIT INTAKE WITH 0.5 MM WEDGEWIRE SCREENS

Narrow-slot cylindrical wedgewire screens could be installed to reduce fish entrainment and

impingement. Cooling water would be conveyed through submerged, cylindrical wedgewire screens

mounted on a bulkhead wall in front of the existing CWIS. The bulkhead would be constructed to

form a common plenum in front of the existing intakes. Thirty T-36 screens would be mounted on

this wall in three rows of 10 screens.

An air backwash system was originally included to clean the wedgewire screens. The effectiveness

of this cleaning method is contingent on the local tidal currents ability to transport debris flushed

away from the screens. Based on further research, the tidal flow in the ILAH is not expected to be

sufficient to transport fish and debris from the screens. As a result, alternative methods of cleaning

the screens would be necessary. One method to reduce biofouling is to use JohnsonScreen’sZ-alloy,

a nickel-copper alloy material. This would require nine additional screens and would more than

double the cost per screen. In addition to the new material, a method for removing debris from the

screens would be necessary. This could be done by removing and cleaning the fouled screens on the

CWIS deck or manual cleaning of the screens by divers.

Conclusion

If the screens could be maintained, the efficacy of this technology would be high and has potential to

significantly reduce entrainment and meet the entrainment reduction performance standards.

3.3 FLOW REDUCTION

Using Variable Speed Drives (VSDs) would be an effective method to reduce flow. The VSDs would

allow much finer control of flow reductions, while ensuring adequate flow to meet heat rate and

generation needs. The level of the reduction achievable with VSDs, without effecting generation,

would vary depending on load and inlet water temperature. The maximum reduction associated with

VSDs would be about 40 percent. A flow reduction of 40% would not meet either the impingement

or entrainment standard, but could be used to in conjunction with another technology to meet the

standards.

If LADWP were to install VSDs on the circulating water pumps a detailed, design review of

condensers, circulating water pumps, motors, and piping would need to be conducted to identify

potential issues associated with VSDs. Some key operational issues that would need to be addressed

are: unbalanced pump operation if a VSD is placed on only one pump, loss of pressure in the

condenser waterboxes, vibration of the pumps at lower speeds, and potential to burn out the existing

motors. This review will further identify the limitations that may exist and provide recommendations

for each unit upgrade. The cost to install VSDs on all the circulating water pumps is included in the

cost section. The following upgrades are not included in our cost estimate; but would be required

prior to installing VSDs:

 Installation of a back-pressure valve on the condenser discharge;

 Installation of pump discharge valves;

 New circulating water pumps; and

 New pump motors.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

3-4

HGS currently has only one unit, Unit 5, operating with once-through cooling. Unit 5 operates off of

waste heat from Units 1 and 2. Units 3 and 4 have been retired and Units 10-14 are simple-cycle

turbines with cooling towers. If credit can be taken for designing Units 1, 2 and 10-14 without oncethrough cooling the entrainment reduction standard will be met.

Conclusion

Consideration of flow reduction remains a possible alternative. Typically, flow reductions, if they

affect generation, would need to be discussed with Corporate Power Supply. Assessment of general

trends in load demand can predict periods where running at reduced loads or placing a unit(s) on

standby would not affect reliability of the plant. These flow reductions would result in some flow

reduction credit. Due to the already low intake velocities at HGS, VFDs would not provide any

additional benefits associated with reducing the velocity. During periods of high demand and high

water temperatures, reducing flow may result in the need to de-rate the unit(s) to maintain thermal

discharge limits. Use of VSDs could be considered to better control flow reductions and minimize

lost generation. Costs for VSDs have been included in this Addendum. Regardless, this option by

itself would not likely meet the entrainment reduction standard.

3.4 CLOSED-CYCLE COOLING

Closed-cycle cooling was assessed on a cursory level in the 2004 report. LADWP is participating in

the closed-cycle cooling retrofit cost evaluation study. The results of this evaluation will identify the

economic penalties associated with this option. It is also important to consider several options for use

of closed-cycle cooling. There is the potential that, when considering revisions to the Rule, EPA

could determine that use of wet or dry closed-cycle cooling is BTA. There are significant arguments

to be made that the cost of a national retrofit cannot be borne by industry. However, if EPA identified

closed-cycle cooling as BTA, it would be consideredthe“bestperforming”technology.Underthis

scenario the Cost-Cost test (after re-proposal for review and comment) could still determine that

closed-cycle cooling has a cost significantly greater than the cost estimated by EPA.

Conclusion

Closed-cycle cooling will meet all performance standards, but whether or not closed-cycle cooling

will be required to meet the standard is not know at this time. Cooling towers would have the highest

overall capital and operating and maintenance (O&M) cost of all of the alternatives

3.5 ADDITIONAL TECHNOLOGIES

Originally, the MIS was proposed as a technology to reduce impingement mortality by virtue of a 2

mm slot size (the only size for which data are available). However, in reconsidering entrainment

reduction alternatives, Alden proposed consideration of the MIS for reducing entrainment of larger

entrainable organisms. Results of species-specific survival from pilot studies of both the fine-mesh

traveling screens and the MIS could be compared to develop overall efficacy.

All the ancillary issues, such as transport to a safe location in the source waterbody, associated with

fine-mesh screens apply to the MIS. Additionally, the traveling water screens would need to be left in

place and operational to collect debris from the screen when it is rotated for cleaning. Biofouling of

the screen mesh may also be an issue. Therefore, the Z-alloy as described in the narrow-slot,

wedgewire section could be used to prevent bio-fouling of the screens. Alden recommends a pilot

study to determine the biologic effectiveness and gage the biofouling if MIS are to be considered for

full-scale application at HGS. MIS units have not been tested with slot sizes smaller than 2.0 mm;

however, the design of the MIS could be modified to accept a smaller slot size. Any changes in mesh
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

3-5

size would need to be tested prior to full-scale application. If the MIS proved effective, and

biofouling issues were resolved during the pilot tests, then the MIS could be a good option at HGS.

Conclusion

As with the fine-mesh screen alternative, the projected efficacy of this technology will be less than

that for narrow-slot wedgewire screens. However, depending on the ultimate efficacy for the finemesh screens, this alternative may be as effective as the other fine-mesh screen options. Alden does

not believe that MIS with 2.0 mm slot size will meet the entrainment reduction standard; however, an

MIS with a smaller slot size may be able to meet the standard. The results of the pilot study will

remove this uncertainty. The ultimate cost of the systems would dictate the technology selection.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

4-1

4.0 IMPINGEMENT MORTALITY REDUCTION OPTIONS

Asstatedpreviously,technologiesconsideredforcompliancewithEPA’sentrainmentreduction

performance standards would also be applicable for the impingement mortality reduction standards.

Technologies that would reduce only impingement were not evaluated in the 2004 evaluation for HGS.

However, after reconsideing options for HGS, there are several technologies that could be used to reduce

impingement mortailty.

4.1 COARSE-MESH MODIFIED TRAVELING SCREENS

Coarse-mesh modified traveling screens could be used at HGS to reduce impingement mortality. The

existing screen approach velocity with two screenbays in operation and at mean low water level is

about 0.8 ft/sec at full flow. For many species, this velocity is within the range of velocities that has

demonstrated good survival with traveling screens that been modified for fish protection at other

facilities (Ristroph screensinAlden’soriginalreport).Limitedsurvivaldataexistforspecies

impinged at HGS. Therefore, Alden still recommends conducting pilot studies before any further

consideration of full-scale installation. A pilot study proposed for HGS would identify where

survival of previously entrained organisms starts to occur.

To prevent reimpingement of the fish and debris, the return would need to be routed along the

discharge pipe. As a result, organisms collected from the screens would have to be transported about

1,400 feet through a return pipe. In addition, fish and shellfish species and their associated life stages

tend to vary considerably in terms of their ability to tolerate the collection and handling associated

with this option, which emphasizes the need for species and life stage specific testing to verify

survival rates. Alden believes that there are methods for maintaining a clean fish return system. A

review and comparison of two potential fish return cleaning systems is provided in Attachment E.

Conclusion

Coarse-mesh modified traveling screens are a viable alternative for impingement mortality reduction.

Alden is uncertain if this standard could be met with the species present at HGS and, therefore,

recommends that a pilot study be conducted if this alternative is considered further.

4.2 WIDE-SLOT CYLINDRICAL WEDGEWIRE SCREENS

LADWP could install a wide-slot cylindrical wedge wire screen intake at HGS to reduce fish

impingement. Two stainless steel, T-84 screens with 9.5 mm slot openings would be required to

accommodate the total facility flow. These screens would be mounted onto a bulkhead wall similar to

the narrow-slot option. The design through slot velocity would be about 0.5 ft/sec with clean screens.

The screens would be angled so that they were parallel to the predominant currents in the area.

The effectiveness of an air backwash system to clean wedgewire screens is contingent on the presence

of local tidal currents to transport debris flushed away from the screens. Based on available

information, the tidal flow in the ILAH is not expected to be sufficient to serve this purpose. As a

result, alternative methods of cleaning the screens would be necessary. Installing an extra screen at

HGS would allow LADWP to sequentially remove each wedgewire screens for cleaning without

increasing the through mesh velocity above 0.5 ft/sec. A second method to reduce biofouling is to

useJohnsonScreen’sZ-alloy, a nickel-copper alloy material. This approach would not require any

additional screens but would more than double the cost per screen.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

4-2

Conclusions

Wide-slot cylindrical wedgewire screens would meet impingement standard via Compliance

Alternative 1. Since an air backwash system is not expected to be effective at HGS, Alden has

included costs for a third screen to allow for manual cleaning.

4.3 FLOW REDUCTION

PriortotheCourt’sDecision,EPAwasconsideringissuingguidancerelativetotherelationshipof

impingement and flow. EPA indicated they were considering guidance that would allow facilities to

assume proportionality between flow and impingement. As with entrainment, flow reduction remains

an alternative but can only be considered in conjunction with another technology. That is, the

curtailment in generation required to meet the remanded impingement mortality reduction standard of

80-95% using flow reduction alone is not practicable or cost-effective.

Conclusion

Consideration of flow reduction remains a possible alternative. Typically, flow reductions need to be

discussed with Corporate Power Supply. Assessment of general trends in load demand can predict

periods where placing Unit 5 on stand-by would result in some flow reduction credit. Shutting off

pumps during high periods of impingement would result in the need to de-rate the unit to maintain

thermal discharge limits. Use of variable speed drives could be considered to better control flow

reductions and minimize lost generation. Costs for variable speed drives have been included in this

addendum. Regardless, neither option would likely meet the impingement mortality reduction

standard.

4.4 CLOSED-CYCLE COOLING

Closed-cycle cooling was assessed on a cursory level in the 2004 report. LADWP is participating in

the closed-cycle cooling retrofit cost evaluation study. The results of this evaluation will identify the

economic penalties associated with this option.

Conclusion

Closed-cycle cooling will meet all performance standards. However, Alden does not believe it is

reasonable to consider it for impingement only.

4.5 ADDITIONAL IMPINGEMENT REDUCING TECHNOLOGIES

As with consideration of additional entrainment reduction alternatives, there are other impingement

reduction alternatives that have been suggested to be considered.

Passive screening (e.g. coarse-mesh barrier nets) requires low through-net velocities to exclude fish.

This type of technology would have to be placed in the ILAHC where it could interfere with other

commercial activities. Therefore, Alden does not consider a passive screening system to be a viable

alternative for HGS.

Conclusion

Although impingement-only alternatives are available, Alden does not recommend further

consideration of impingement-only options in light of the Second Circuit Court Decision.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

5-1

5.0 COST UPDATE

The revised costs presented in Table 5-1 are an update of the estimated costs provided in Table 6-3 of

the original report. The update includes an escalation from 2002 dollars to 2006 dollars, as well as

changes in the site-specific factors that impact the installation and O&M of the compliance

alternatives. Estimated costs for installing a MIS, VSDs and impingement only technologies at HGS

have been added to this table. These costs were calculated using the same costing methodology as

used in the 2004 evaluation.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

5-2

TABLE 5-1. ALDEN’S APPRAISAL LEVEL COSTS OF EVALUATED ALTERNATIVES

Estimated from Alden Database

Alternative Construction

Costs

(2006 $)

Replacement

Power During

Shutdown

(MWh)

Total

Capital

Cost

(2006 $)1

O&M

Costs

(2006 $)

Lost

Generation

(MWh) 2

Annualized

Capital

Costs

(2006 $)

3

Incremental

Annualized

O&M Costs

(2006 $)1, 2

Total

Incremental

Annualized

Costs

(2006 $)

Retrofit Screenhouse with

Fine-mesh Ristroph Screens $1,859,000 0 $1,859,000 $235,000 1,051 $265,000 $274,000 $539,000

Install Narrow-slot

Wedgewire in front of the

Existing CWIS

$2,397,000 0 $2,397,000 $549,000 0 $341,000 $535,000 $876,000

Modular Inclined Screen in

the Existing Intake $2,486,000 0 $2,486,000 $19,000 270 $354,000 $33,000 $387,000

Install VSDs on the

Circulating Water Pumps $652,000 0 $652,000 $0 0 $93,000 $0 $93,000

Retrofit Screenhouse with

Coarse-mesh Ristroph

Screens

$1,080,000 0 $1,080,000 $120,000 526 $154,000 $132,000 $286,000

Install Wide-slot Wedgewire

in front of the Existing CWIS $1,387,000 0 $1,387,000 $289,000 0 $197,000 $275,000 $472,000

Existing Operations $0 0 $0 $0 0 $0 $0 $0

Retrofit Plant with Closedcycle Cooling System4 $16,800,000 105,000 $22,050,000 $336,000 4,610 $2,815,000 $553,000 $3,368,000

1. Based on a cost for lost generation of $50 per MWh.

2. Includes costs as a result of any power penalties associated with the technology.

3. Alden assumed a discount rate of 7%, and an amortization rate of 10 years for the capital costs and 30 years for the pilot study and downtime costs.

4. Cooling tower costs based on EPRI study (EPRI 2002a).
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

6-1

6.0 DATA GAPS AND UNCERTAINTIES

As with any assessment of alternatives, there are a number of data gaps and/or uncertainties

associated with individual facility location, design, and operation for specific options. These

uncertainties are further exacerbated by the variability of the biological community characteristics

(e.g. diel/seasonal abundance, life stage, species) at the site.

Table 6-1 provides a summary of these uncertainty considerations for each of the alternatives

considered in 2004 and in this document for HGS.

TABLE 6-1. ALTERNATIVE DATA GAPS AND UNCERTAINTIES

Alternative Data Gaps Uncertainties

Fine-mesh Traveling Screens Length and species-specific

survival data from the screen

and fish return line; and

Biofouling impacts;

Near shore return survival.

Effective mesh size;

Effective approach velocity; and

Annual variability in species

composition.

Narrow-slot Wedgewire

Screens

Length and species-specific

exclusion data; and

Biofouling impacts.

Effective mesh size;

Effective“sweeping”velocity;

Annual variability in species

composition;

Biofouling; and

Effective cleaning method.

Modular Inclined Screens Length and species-specific

survival data from the screen

and fish return line; and

Biofouling impacts;

Near shore return survival;

Only 2.0 mm slot width has

been tested.

Effective mesh size;

Effective approach velocity; and

Annual variability in species

composition.

Flow Reduction Reasons for installing

combined cycle units

Seasonal species distribution

and relative abundance.

CalEPA acceptance of preexisting flow reduction

Coarse-mesh Traveling

Screens

Length and species-specific

survival data from the screen

and fish return line.

Biofouling impacts; and

Plant-side return survival.

Annual variability in species

composition.

Wide-slot Wedgewire Screens Biofouling impacts. Effective“sweeping”velocity;

Effective cleaning method; and

Annual variability in species

composition.

Closed-cycle Cooling Unit-specific retrofit; and

Available space.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

6-2

The data gaps that exist with species composition, survival, and diel/seasonal presence and variability

can only be reduced by extended abundance sampling (IM&E studies) or alternative/componentspecific pilot studies. Each technology will have a different efficacy for reduction in station effects.

The pilot studies proposed for HGS (fine-mesh traveling screens) and Haynes Generating Station

(HnGS) (MIS) will provide data on length-related, species-specific survival. Macrofouling on the

continuously operating screens can be determined during the pilot studies, as well as debris handling

capabilities. Macrofouling and subsequent predation on entrained organisms could be assessed

during a pilot study. However, a more prudent approach would be to develop an effective return line

treatment technique based on actual plant operating data.

Pilot studies could also reduce the uncertainties of the effects of mesh size and approach velocities on

organism survival. These issues, however, would probably be best determined after results from the

above studies were available.

The uncertainties associated with annual variability in species abundance and composition as they

relate to the ability to meet performance standards cannot be reduced by pilot studies. It is anticipated

thatsurvivalamong“hearty”and“fragile’specieswill vary, and a change in composition towards

“fragile”specieswilljeopardizecompliancepotential.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

7-1

7.0 CONCLUSIONS

This assessment indicates that:

 Replacing the original once-through units at HGS with combined-cycle units results in a

theoretical flow reduction of 68 percent. If LADWP can document that the decision to use

combined- cycle units was done in part for ecological reasons then they may be able to take

credit for dramatically reducing impingement and entrainment.

 The two new technologies currently available (i.e., Hydrolox and Geiger screens) can be

considered in the same category as modified Ristroph screens. Both of these systems

functiononthe“trapandtransfer”conceptandrequirethesametypeoffishanddebris

returns as Ristroph screens. The potential use of either of these technologies does not change

Alden’spreviousassessment.

 The2006impingementandentrainmentdatadonotalterAlden’sselectionofappropriate

technologies for consideration in reducing entrainment at HGS. The overall efficacy of any

entrainment reduction technology is mitigated by the predominance of very early life history

stages.

 The Court’sDecisionto remand restoration and the cost-benefit test severely limits

LADWP’soptions,butdo notaffectAlden’stechnology and operationalmeasures

assessments.

 BasedonEPA’sposition,itisanticipatedthatascheduleextensionwillbeprovidedto

accommodate the rulemaking process. That time can be used to pursue pilot studies and

continue to consider additional options.

 Conclusions for entrainment:

 Closed-cycle cooling is the only option identified that will meet all performance

standards. The ultimate reduction in flow associated with a marine installation was not

determined.

 Fine-meshtravelingscreensaretechnicallyan“exclusiontechnology.”However, unlike

narrow-slot wedgewire screens that depend on an air-burst cleaning system, coupled with

ambientcurrentsto“carry”impingedfishanddebrisawayfrom theCWIS,this

technologyutilizesa“trapandtransfer”concept.Theprocessofcollectingorganismsto

assess survival imparts some level of mortality, which is difficult to ascertain in the field.

Consequently, the projected efficacy of this technology will be less than that for narrowslot wedgewire screens.

 As with the fine-mesh traveling screens, the projected efficacy of MIS will be less than

that for narrow-slot wedgewire screens. However, depending on the ultimate efficacy for

the fine-mesh screens, this alternative may be as effective as the other fine-mesh screen

options.

 Effective methods to clean the narrow-slot wedgewire screens would need to be

determined prior to any full-scale application.

 If EPA does not designate closed-cycle cooling as BTA, pilot studies would be necessary

todeterminethe“bestperforming”entrainmentreductiontechnology.
Addendum To The 316(B) Evaluation Of The Harbor Generating Station

7-2

 Conclusions for impingement only:

 Coarse-mesh traveling screens are still a viable alternative for impingement mortality

reduction.

 Wide-slot wedgewire screens would meet the impingement mortality standard; however

an effective method of cleaning the screens would be needed prior to consideration for

full scale application.

 Consideration of flow reduction remains a possible impingement mortality reduction

alternative. The same comments previously discussed for entrainment reduction apply to

this alternative.

 Although impingement-only alternatives are available, Alden does not recommend

further consideration of impingement-onlyoptionsinlightoftheCourt’sDecision.
Attachment A Addendum To The 316(B) Evaluation Of The Harbor Generating Station

1

ATTACHMENT A -

SUMMARY OF 2004 EVALUATION OF HGS

The following provides a summary of the “EvaluationoftheHarbor Generating Stations with respect

totheEnvironmentalProtectionAgency’s316(b)RulesforExistingFacilities”,December2004,

prepared by Alden Research Laboratory, Inc. (Alden) and EPRI.

Scope of the Analysis

In response to the Rule, Electric Power Research Institute (EPRI) and Alden conducted a strategic

assessment for Los Angeles Department of Water and Power (LADWP) Harbor Generating Station

(HGS). This assessment evaluated the impact of the Rule on HGS, including potential cost-effective

compliance alternatives, additional information collection needs, and relative budget impacts as a

result of studies and compliance alternatives.

The major component of this analysis was a preliminary evaluation of alternative fish protection

technologies to meet the applicable performance standards for HGS and discussion of approximate

costs for the feasible alternatives. As part of this alternatives analysis, Alden reviewed operational

options for meeting the applicable performance standards.

This report addressed technologies, operational changes, and restoration measures that LADWP could

implement to meet the Rule. The U.S. Environmental ProtectionAgency’s(EPA’s) favored approach

was to reduce total fish losses, which did not address AEI at the population and ecosystem levels.

Therefore, traditional measures of population and ecosystem health, such as species diversity and

richness, were not addressed. Further, EPA did not consider factors that influence populations such

as compensatory mechanisms, species fecundity, and natural mortality. Therefore, these factors were

not considered.

Technologies and Operational Measures

The preliminary evaluation of alternative technologies and operational measures that could be

considered by LADWP to meet the impingement mortality and entrainment (IM&E) standards at

HGS was presented in the report.

Alden’spreliminaryjudgmentonhowlikelythesealternatives were to actually meet these standards

was summarized as follows:

Alternative

Will It Meet the Impingement

Mortality Reduction

Standard?

Will It Meet the

Entrainment Reduction

Standard?

Fine-mesh Ristroph Screens

Yes, provided that impingement

survival of key species is at least

80 percent.

Yes

Narrow-slot Wedgewire Screens Yes Yes

Existing Facility Operations Yes, the through screen velocity is

less than 0.5 ft/sec.

Yes, if the existing operations

provide a flow reduction of

greater than 60% from a

hypothetical baseline flow.

Closed-cycle Cooling Yes Yes
Attachment A Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2

The annualized costs of these alternatives as compared with the costs EPA used in developing the

Rule were:

Alternative Alden’sAnnualized

Cost(2002 $)

EPA’sAnnualizedCosts

(2002 $)

Fine-mesh Ristroph Screens $486,000

Narrow-slot Wedgewire Screens $470,000

Existing Facility Operations $0

Closed-cycle Cooling $3,206,000

$130,007

Key findings of our preliminary (2004) analysis were:

 The design and operation of Units 1 and 2, 5 and 10-14 may provide HGS with an 84%

reduction in flow from a theoretical baseline if all eight units were designed and operated as

once-through units. If only Units 1, 2, and 5 are considered, then the existing operations

would result in a flow reduction of 68 percent. Because flow and entrainment are directly

proportional (assuming equal distribution of organisms), this flow reduction should reduce

entrainment by greater than the 60% required by the Rule.

 The existing through-screen velocity at the traveling water screens is less than 0.5 ft/sec

during normal plant operations. HGS should automatically meet the impingement mortality

reduction standard via Compliance Alternative 1due to this low velocity.

 Two technologies (i.e., fine-mesh Ristroph screens and narrow-slot wedgewire screens) and

two operational options (i.e., existing operations and closed-cycle cooling) were considered

to have potential for meeting the IM&E reduction standards and were deemed practicable

from an engineering standpoint. As the existing CWIS should already meet the impingement

mortality reduction standard, technologies that reduce only impingement mortality were not

evaluated.

 Of the four options that could meet the entrainment reduction standard, Alden estimates the

annualized costs range from $0 for to maintain current operations to $3,206,000 for closedcycle cooling.

 If the existing operations at HGS do not meet the IM&E standard, replacing the existing

screens with fine-mesh Ristroph screens or narrow-slot wedgewire screens have the greatest

potential to meet the standards. The annualized costs for these technologies are $486,000 for

fine-mesh Ristroph screen and $470,000 for narrow-slot wedgewire screens.

The following general considerations were used to develop conceptual designs of alternative fish

protection technologies for application at HGS. Alden used the criteria to evaluate the relative

advantages and disadvantages of each option and to select for consideration those technologies with

the greatest potential to meet the performance standards at HGS. The criteria were:

 Alternatives should be designed to reduce impingement mortality by 80–95% from the

“calculationbaseline.”

 Alternatives should be designed to reduce entrainment by 60–90% from the“calculation

baseline.”
Attachment A Addendum To The 316(B) Evaluation Of The Harbor Generating Station

3

 Alternatives should provide protection for species that are potentially susceptible to IM&E at

HGS.

 The period of protection is year-round for impingement and nine months for entrainment.

 Alternatives should take into consideration current project design features, as summarized in

Table 2-1 in the Addendum3.

 Alternative designs should have suitable conditions for fish protection over the full range of

intake flows and water depths at the CWIS.

 Alternatives should provide effective protection throughout the entire water column such that

they are effective with all species potentially susceptible to IM&E.

 Alternatives should function under expected debris loading and hydraulic conditions in the

harbor (i.e., reasonable cleaning techniques are available and demonstrated).

 Alternatives should preserve, to the extent possible, the existing civil/structural features.

 Alternatives should meet worker and public safety requirements.

 Alternatives should not adversely impact navigation.

 Alternatives should be compatible with the other aesthetic and recreational features of the

region.

The screening process was as objective as possible. However, in assessing the potential for

application of fish protection schemes under physical, hydraulic, and in environmental conditions that

they have never been applied, the Team had to use best professional judgment based upon experience.

The Team deemed a technology to have proven biological effectiveness if test data (preferably from

full-scale application) were available that documentedatechnology’seffectivenesswithoneormore

of the species present at that site. If engineering data exist in sufficient detail to develop a conceptual

design, and/or if the technology has been constructed at another site, it was judged it to be an

available technology. Each technology was qualitatively assessed to identify whether it had biological

and/or engineering advantages over the other alternatives. For example, an intake technology that has

been proven effective at reducing losses for many species and under a variety of intake conditions has

a biological advantage over one that has been proven effective with a few species or under limited

intake conditions. From an engineering perspective, one technology may hold an advantage over

another if the civil/structural requirements for its installation are substantially less.

Behavioral barriers to protect juvenile and adult fish have been the subject of extensive research. The

use of strobe lights to elicit a behavioral response is supported by the results of laboratory and cage

test studies that have demonstrated strong avoidance by several fish species to strobe lights. Strobe

lights have been evaluated for repelling or guiding juvenile and adult fish away from water intakes

(EPRI 1994, 1999) and, in many cases, toward bypasses for transport to a safe release location. There

is some evidence that combining strobe lights with an air bubble curtain can provide effective fish

deterrence. However, results have been species- and site-specific.

3

See Table 2-1 (Revised) for updated assessment.
Attachment A Addendum To The 316(B) Evaluation Of The Harbor Generating Station

4

The focus of recent studies involving underwater sound technologies has been on the use of low- and

high-frequency acoustic systems that were not available for commercial use until the 1990s. Highfrequency (120 kHz) sound has been shown to effectively and repeatedly repel members of the genus

Alosa (American shad, alewife and blueback herring) at sites throughout the U.S. (Ploskey et al.

1995; Dunning 1995; Consolidated Edison 1994). Other studies have not shown sound to be

consistently effective in repelling species such as largemouth bass, smallmouth bass, yellow perch,

walleye, rainbow trout (EPRI 1998), gizzard shad, Atlantic herring, and bay anchovy (Consolidated

Edison 1994).

Based on the results of behavioral barrier studies conducted over the past 30 years, a hybrid barrier

consisting of light, sound, and air bubbles would be most effective on Alosids. Little or no

information is available on the potential effectiveness of a hybrid barrier with several of the

numerically dominant species at HGS. Given that Alosids are absent from the fish assemblage

impinged at HGS, a hybrid barrier would not reduce impingement to a level that meets the

impingement mortality reduction standard and, thus, these types of barriers were removed from

further consideration at HGS.

The existing intake at HGS incorporates 3/8 in. square mesh traveling water screens that would be

relatively easy to modify for installation of Ristroph screens. Ristroph screens are very similar to

conventional traveling water screens, except they are designed with extra features to collect and

transport impinged organisms safely back to the waterbody. Fine-mesh Ristroph screens have the

potential to meet both standards, while coarse-mesh Ristroph screens may meet only the impingement

mortality standard. In addition, Ristroph screens are designed for continuous operation to minimize

impingement duration. Continuous rotation along with the associated spray washes provides Ristroph

screens with an automatic screen-cleaning feature. This gives them an engineering advantage over

fixed screens, barrier nets, and bar rack barriers, all of which would require an additional cleaning

system. Fine mesh Ristroph screens can be considered a viable alternative for reducing both IM&E.

If only the entrainment standard needs to be met at HGS, fine mesh screen overlays could be used.

These screens would be more cost effective than Ristroph screens, as they would use the existing

traveling water screens modified to accept a fine mesh screen material. However, these screens

would not include the Ristroph fish handling and return components. Fine mesh traveling screens

would meet the word of the Rule by significantly reducing entrainment numbers. Impingement

mortality of entrainable organisms off of fine mesh traveling screens, however, is expected to be near

100% and would, therefore, have no net benefit. The Team does not expect Environmental Protection

Agency would accept changing an entrainment issue into an impingement issue. As a result, fine

mesh traveling screens are not considered a viable option for HGS.

Modification of the screenhouse to incorporate physical barriers or other diversion systems to prevent

entrainment and impingement mortality would be difficult. Rotary drum screens and porous dikes

require a much larger area than conventional traveling screens because of the lower design velocity.

Rotary drum screens are typically installed in channels where water elevations are relatively constant

and water depths are less than 12 feet, which is less than the water depth near the HGS intake. Bar

rack barriers are typically designed to have spacing greater than 1 in. and would not be effective in

preventing the entrainment of early life stages. They may, however, be effective at reducing

impingement.

The Modular Inclined Screen (MIS) and Eicher screen have a biological and engineering advantage

over louvers, angled bar racks, and angled screens in preventing impingement. Both screens offer the

potential to effectively divert most species by using smaller structures than the other screen concepts.

The MIS, for example, is designed to operate at velocities up to 10 ft/sec. However, the MIS has not
Attachment A Addendum To The 316(B) Evaluation Of The Harbor Generating Station

5

been shown to protect larval fish, and the Eicher screen is designed for installation in hydroelectric

project penstocks. Therefore, these diversion technologies are not applicable to HGS where

impingement and entrainment are both of concern.

The existing intake could be modified to incorporate cylindrical wedgewire screens, thus providing

this technology with an engineering advantage over the porous dike, infiltration intake, and bar rack

barriers (Table 2-3 in Addendum). Wedgewire screens also have cleaning features that give them an

advantage over other fixed screens and barrier nets that are more difficult to maintain. This cleaning

feature requires the presence of a sweeping current to be effective. Cylindrical wedgewire screens

have a biological advantage in that they can exclude more life stages from intake water than

conventional screens and bar racks. For this reason, wedgewire screens have been included in the

preliminary evaluation for HGS.

Aquatic filter barriers (AFBs) could perform a similar function to fine mesh traveling water screens.

The AFB has an engineering advantage over barrier nets relative to cleaning (Table 2-3 in

Addendum). An AFB has two layers of material with an air purge system installed between the layers

to permit automatic cleaning of accumulated silt and debris. This cleaning system can also free

impinged fish larvae and other non-motile life stages. The flow approaching an AFB is currently

limited to10 gpm/ft2. HGS would require about 7,500 ft2of AFB to achieve this velocity. An AFB at

HGS would have to be approximately 225 feet long, assuming a 33 foot average low water depth in

front of the intake structure. Placing an AFB in the Inner Los Angeles Harbor (ILAH) would

interfere with shipping activities. Therefore, an AFB is not considered a viable alternative for

preliminary evaluation for HGS.

Fine mesh barrier nets (<0.5 mm) are easily fouled by silt and algae, require labor-intensive cleaning,

and are considered experimental for reducing entrainment at this time. However, coarse mesh nets

could reduce impingement if they were installed in a low velocity zone and periodically cleaned to

remove debris accumulation and biofouling growth. A barrier net at HGS, however, would have to be

installed in the ILAH and would interfere with shipping in the channel. Additionally, the design

through-screen velocity of the existing traveling water screens appears to be less than 0.5 ft/sec,

therefore automatically meeting the impingement mortality performance standard via Compliance

Alternative 1. A barrier net is therefore not considered a viable alternative for preliminary evaluation

at HGS.

The preliminary screening of intake technologies available for fish protection (Table 2-3 in

Addendum) indicates that two intake alternatives have the greatest potential for application to reduce

fish IM&E at HGS:

 Expanded intakes with fine mesh4 Ristroph screens; and

 Wedgewire screens with 0.5 mm openings.

Two flow reduction options were identified to reduce entrainment and, to a lesser extent,

impingement:

 Existing reduced flow operation; and

 Install an additional closed-loop cooling system.

4 Theterm“finemesh,”asusedinthisdocument,refersto0.5mm(0.02in.)squarewovenmesh.
Attachment A Addendum To The 316(B) Evaluation Of The Harbor Generating Station

6

HGS currently has only one unit, Unit 5 operating, with once-through cooling. Unit 5 operates off of

waste heat from Units 1 and 2. Units 3 and 4 have been retired and Units 10-14 are simple cycle

turbines with cooling towers. Designing Units 1, 2 and 10-14 without once-through cooling may

already result in a reduction in flow from a hypothetical baseline with all units operating as oncethrough that will meet the entrainment reduction standard. However, closed-cycle cooling could

provide an even greater reduction in entrainment than the current plant design.

Mechanical or natural draft wet towers would require less modification to the existing circulating

water system piping and less real estate than dry cooling towers. The costs for construction of a wet

mechanical cooling tower are about 60% less than the natural wet cooling tower. Natural wet cooling

towers require less energy to operate and have lower annual costs than a wet mechanical draft tower.

However, wet mechanical draft towers generally have less aesthetic and air quality impacts than

natural draft wet towers. The area surrounding HGS is heavily industrialized and would probably not

be affected by compromised air quality. The site is, however, located near the city of Los Angeles.

Since aesthetics and air quality issues would probably be greater for natural draft towers than for

mechanical draft towers, wet mechanical draft towers were chosen as the closed-cycle cooling system

option for preliminary evaluation.
Attachment B Addendum To The 316(B) Evaluation Of The Harbor Generating Station

1

ATTACHMENT B -

LADWP RESTORATION OPTIONS

1.0 INTRODUCTION

In 2004, Alden Research Laboratory, Inc. (Alden) and the Electric Power Research Institute (EPRI)

conducteda316(b)strategicassessmentfortheLosAngelesDepartmentofWaterandPower’s

(LADWP) Generating Stations: Harbor Generating Station (HGS), Haynes Generating Station

(HnGS), and Scattergood Generating Station (SGS). As part of that assessment, the use of restoration

as a 316(b) compliance alternative was evaluated. That evaluation analyzed restoration project

categories, and included summaries of nationwide restoration projects.

The purpose of this attachment is to update the Alden and EPRI evaluation, provide information on

specific projects applicable to offsetting entrainment and/or impingement losses at the LADWP

Generating Stations, summarize the process of implementing restoration projects, and identify data

gaps that are required to be addressed prior to developing a 316(b) Restoration Plan for inclusion in

the Comprehensive Demonstration Study for each Generating Station.

2.0 SUMMARY OF 2004 ALDEN/EPRI RESTORATION EVALUATION

2.1 TYPES OF RESTORATION APPLICABLE TO 316(B)

The 2004 Alden/EPRI evaluation identified several categories of restoration projects that have been

used at other facilities nation-wide. These included:

 Wetlands restoration;

 Fish stocking;

 Submerged aquatic vegetation (giant kelp) restoration;

 Provision of fish passage;

 Contribution to a restoration fund; and

 Water quality improvements.

The two general requirements for the use of restoration are (1) a demonstration that the use of

technologies and/or operational measures was evaluated, and the use of restoration measures is

appropriate because meeting the performance standards through implementation of technologies

and/or operational measures is less feasible, less cost-effective, or less environmentally desirable than

meeting the performance standards in whole or in part through the use of restoration, and (2) a

demonstration that the use of restoration will produce ecological benefits (production of fish and

shellfish) at a level that is substantially similar to that which would be achieved through

implementation of technologies, operational measures, and/or alternative site-specific requirements.

2.2 SPECIFIC RESTORATION EXAMPLES FOR HGS, HNGS, AND SGS

Alden/EPRIprovidedseveralexamplesofpotentialrestorationprojectsapplicabletoLADWP’s

coastal generating stations. These examples are summarized below.
Attachment B Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2

Fish Stocking

Stocking of fish would provide direct replacement of affected species. Examples included stocking of

lake sturgeon (Coosa River, Georgia/Alabama), Atlantic Sturgeon (Patuxent River, Maryland),

American shad (Susquehanna River, Maryland/Pennsylvania), and white seabass (southern

California).

Habitat Protection Programs

Habitat restoration, and particularly wetland restoration, has become increasingly popular due to the

decline of various habitats with time. Participation in a restoration program would also provide the

benefit of fish production. Examples included the San Dieguito Lagoon restoration (SCE San

Onfore), the Morro Bay Habitat Enhancement Program (Duke Energy Morro Bay), the Delaware Bay

Estuary Enhancement Program (PSEG), and the Santa Monica Bay Restoration Commission (Los

Angeles, California). Other examples were provided related to restoration-related groups that might

assist in the facilitation of restoration projects, including the National Centers for Coastal Ocean

Science, the National Estuaries Restoration Inventory, the NOAA Community-based Restoration

Program,theU.S.FishandWildlifeServicePartnershipforFishandWildlife,andCoastalAmerica’s

Corporate Wetlands Restoration Partnership.

Dam Removal or Fishway Construction

The U.S. Fish and Wildlife National Fish Passage Program is designed to restore native fish and other

aquatic species to self-sustaining levels by reconnecting habitat that has been fragmented by barriers,

where such reconnection would not result in a net negative ecological effect. Examples included

installation of fishways (Delaware Bay), and a potential dam removal project (Rindge Dam, Malibu

Creek).

Alternative Restoration Projects

Other potential restoration projects could include runoff abatement programs and removal of

contaminated sediments to improve water/sediment quality and habitat.

2.3 316(B) RESTORATION IMPLEMENTATION PROCESS

The use of restoration as a compliance alternative will require coordination and agreements among a

number of regulatory agencies and stakeholder groups. If LADWP decides to implement a project

that it would fund and manage in cooperation with federal, state, and local resource agencies, the

process could include the following at a minimum:

 Identify projects with involvement of resource agencies and stakeholder groups.

 Scale project to meet desired goals for offsetting losses attributable to impingement mortality

and entrainment (IM&E).

 Develop implementation plan for restoration with input from resource agencies and

stakeholder groups including:

 Setting goals for project,

 Defining milestones that can be used to measure performance,

 Conducting initial biological and engineering data for plan,

 Developing a verification monitoring plan to ensure that milestones are being met and the

goals for offsetting IM&E losses are achieved, and
Attachment B Addendum To The 316(B) Evaluation Of The Harbor Generating Station

3

 Ensuring that the plan incorporates adaptive management so that restoration activities and

monitoring can be modified to ensure that the final goals of the project are achieved.

 Prepare information for permitting

 May require preparation of Environmental Impact Report and responding to comments

from reviewers that will result in modifications to the project and changes to the

implementation and monitoring plans.

 Use implementation plan to develop requests for proposals for engineering and construction.

 Review proposals and select contractors for management, construction, and monitoring.

 Implement verification monitoring and schedule periodic updates on progress and continue

reviews involving resource agencies and stakeholders.

Due to the complexity, cost, and time involved in this process, another option is to fund an existing

project. LADWP could contribute money to the project and ensure that the existing verification

monitoring plan will supply the necessary information to ensure that the goals of the restoration are

being achieved. Additional funding may be necessary to ensure that verification monitoring is

adequate. An example of the successful implementation of this approach is the funding provided from

the Moss Landing Power Plant (MLPP) to the Elkhorn Slough Foundation (ESF) for their programs

related to the preservation and enhancement of the Elkhorn Slough National Estuarine Research

Reserve (see attached). The success of this program has been widely recognized, and is largely due to

the maturity of the management plan for the slough that was developed by the ESF. The ESF has been

able to leverage the money provided by MLPP many times over to accomplish much more than could

ever be achieved from a single restoration project. The successful implementation of this approach

requires identifying an existing entity like the ESF that has a proven track record with implementing

restoration programs.

3.0 SPECIFIC RESTORATION PROJECTS APPLICABLE TO HARBOR

GENERATING STATION

The purpose of this section is to identify specific, local restoration projects that are potentially

applicable to the HGS, and identify data necessary if each project were to be selected for

implementation. Potential restoration projects should be considered based on their ability to offset

entrainment and/or impingement at HGS.

Any specific conservation, enhancement, or restoration project that is to be used for this purpose

should have a nexus (i.e., offset) to the IM&E effects of the power plants. The projects that were

evaluated to offset potential IM&E losses fell into three basic categories:

 Projects that would directly restore or enhance habitat in the vicinity of HGS (Los Angeles

and Orange counties);

 Projects that enhance habitat through watershed management; and

 Projects that enhance the nearshore coastal environment in the vicinity of HGS (Santa

Monica Bay and San Pedro Bay).

Projects that result in removal of accumulated sediment from coastal wetlands would increase the

coastal salt marsh habitat, which would, in turn, increase their biological productivity. Projects that

restore the tidal flow between the ocean and the wetlands to historic levels would have a similar effect

on productivity. Other projects that involve watershed management could reduce wetland
Attachment B Addendum To The 316(B) Evaluation Of The Harbor Generating Station

4

sedimentation and thus preserve existing wetland habitat. Projects that enhance the biological

productivity of Santa Monica and San Pedro bays could directly offset the loss of productivity in the

same waterbody that occurs as a result of IM&E losses at the three power plants.

The“value”oftheecologicalservicesorbenefitsthatwillresultfromimplementationofanyofthese

restoration projects will be assessed using various habitat models to demonstrate that the ecological

“credits”gainedthroughrestorationwilloutweightheecological“debits”causedbytheIM&E

losses.

Using local environmental planning documents and resource agency recovery plans as references,

three major categories of projects have been identified that are appropriate for inclusion as restoration

alternatives to offset IM&E losses. These projects have the potential to create, restore and preserve

habitat equivalent to the amount of habitat that produced the estimated numbers of impinged and

entrained species of fishes and target invertebrates, as well as the other ecological and environmental

effects of IM&E. Restoration projects are presented that offset potential population effects of IM&E

on specific species and at the same time contribute to the overall health of nearshore/coastal habitats.

3.1 COASTAL WETLAND PROJECTS

At one time, coastal lagoons, salt marshes, and other wetlands created by the merging of creeks and

rivers with the Pacific Ocean characterized the shoreline of Santa Monica Bay, Los Angeles and Long

Beach Harbors, and shoreline areas further south. As these coastal areas became more densely

populated and more highly developed, most of the marshes were filled and the creeks and rivers were

channeled into concrete waterways to eliminate the periodic flooding that plagued these low-lying

areas. In recent years, public sentiment has turned to the task of preserving the remaining wetlands in

this area and, where possible, to restoring those wetlands to a state that more closely resembles

historic conditions.

This category of projects includes actions taken directly within the boundaries of these wetlands to

restore and/or enhance habitats that serve as spawning grounds for fish and other aquatic species.

Projects in this category include the restoration of historic sediment elevations, the redirecting of

freshwater streams into the channels that historically fed these areas, and the reopening of channels to

the ocean that allow tidal flow into and out of the wetlands.

The anticipated results of restoring and protecting the wetland habitats will be used to forecast the

project’squalitativeandquantitativebenefitsrelativetobaselineIM&Elosses.Projectsconsidered

for evaluation include several within Santa Monica Bay, as well as projects in nearby Orange County.

Project summaries are presented in order of coastwise location (upcoast to downcoast)

3.1.1 Zuma Wetlands

Zuma Wetlands is a small, 6-acre, freshwater marsh and creek situated about 38 miles upcoast of the

HGS. The wetlands have historically served as a wildlife corridor and nesting site for a variety of

birds and small mammals. By the early 1990s, periodic dumping of surplus construction and road

building material had heavily impacted the wetlands and surrounding uplands. The existing wetlands

were greatly reduced and, in many areas, native species were completely replaced by exotic

ornamental trees, annual grasses, fennel, mustards, and thistles. High visitation at Zuma Beach has

also impacted the site.

Wetland restoration efforts commenced in 1998 and include the excavation of construction fill,

recontouring of upland habitats, removal of exotic plant species, planting of more than 5,000 native
Attachment B Addendum To The 316(B) Evaluation Of The Harbor Generating Station

5

plants, and the re-creation of an additional 21⁄2 acres of freshwater wetland/dune/riparian habitat.

Restoration of this wetland is an ongoing process, which continues at this time.

3.1.2 Malibu Lagoon

Located approximately 33 miles upcoast of the HGS, Malibu Lagoon is a coastal lagoon and salt

marsh fed by Malibu Creek and its associated watershed. During much of the rainy season (winter

and spring) the lagoon opens into the northern end of Santa Monica Bay. During the summer and fall,

reduced flow from the creek and seasonal rebuilding of the beach area dams the lagoon and cuts off

its connection with the ocean, except during periods of extreme high tide and/or large ocean swells.

Lacking a connection to the ocean, the lagoon becomes a brackish water body whose salinity

fluctuates with freshwater input and evaporation. Several habitat restoration or enhancement projects

are in existence that affect the Malibu Creek and Lagoon directly, or indirectly, due to their influence

on creeks that are tributaries of Malibu Creek.

3.1.3 Topanga Lagoon and Creek

Historically, the Topanga Lagoon covered more than 30 acres, but has now been reduced to only 2

acres (mostly due to the deposition of 800,000 cubic feet of fill into the lagoon during the 1934

realignment of the Pacific Coast Highway). Located approximately 30 miles upcoast of the HGS, the

lagoon is fed by Topanga Creek and its associated watershed. Over the years, development in the area

has increased sedimentation rates, which constrain the channel and impede fish migration by species

that include the endangered Steelhead trout. Upper Topanga Creek is listed on the State 303(d) list of

impaired waterbodies. The Santa Monica Bay Restoration Commission, in conjunction with other

agencies, has conducted a comprehensive Topanga Creek Watershed and Lagoon Restoration

Feasibility Study to identify ways to restore these resources. The California Department of Parks and

Recreation recently purchased 1,659 acres of lower Topanga Canyon, including the current and

historic lagoon sites.

3.1.4 Ballona Wetlands

Located about 20 miles upcoast of the HGS, the Ballona Wetlands contains saltwater marsh,

freshwater marsh, coastal bluff, and dune habitats. The area, at one time, covered approximately

2,000 acres, but due to human encroachment and development, the wetland has been greatly reduced

over the last 100 years. In recent years, about 340 acres of the wetland has been preserved due to the

efforts of numerous organizations that are dedicated to the preservation and restoration of the

wetland. These organizations include Friends of Ballona Wetlands, the Ballona Wetlands Foundation,

and Heal The Bay. Portions of the wetland include tidally influenced marsh areas that act as a nursery

for Santa Monica Bay marine species. Restoration plans for this portion of the wetland are still being

developed. Ballona is the only remaining large coastal wetland in Los Angeles County.

3.1.5 Los Cerritos Wetlands

The Los Cerritos Wetlands is located about 12 miles downcoast of the HGS. The wetland straddles

the Los Angeles-Orange County border. It currently consists of about 130 wetland acres, with nearly

800 acres of degraded habitat proposed for restoration. Historically, it consisted of about 2,400 acres

and included what is now Alamitos Bay. Since much of the site was modified due to former oil

development activities, most of the land was privately held. In 2006, the California Coastal

Conservancy was one of several agencies that purchased 66 acres of the wetlands, and hopes to

acquire more. The Los Cerritos Wetlands Land Trust of Long Beach and Seal Beach is one

organization committed to restoration of the wetlands. A conceptual restoration plan includes full

tidal restoration (inland to Westminster Avenue) via connection to the lower San Gabriel River.

While the proximity of the Los Cerritos Wetlands to the HGS makes it an attractive restoration

option, other considerations associated with the project make it less than ideal. The recently submitted
Attachment B Addendum To The 316(B) Evaluation Of The Harbor Generating Station

6

final report of the City of Long Beach, Los Cerritos Wetlands Study Group (available as a

downloadable pdf file at http://www.longbeach.gov/plan/pb/cpd/los_cerritos.asp) cited several

pressing issues that need to be dealt with in order to proceed with any of the proposed restoration

projects. Two of these issues are the numerous and varied zoning and jurisdictional concerns related

totheareaoftheformerwetlands,andthearea’shistoryofuseasahazardouswastedisposalsite.

These concerns are reflected in the ranking of this restoration option.

3.1.6 Bolsa Chica Lowlands

The Bolsa Chica Lowlands Restoration Project is located about 17 miles downcoast from the HGS

adjacent to the City of Huntington Beach. The purpose of the project is to restore portions of the

wetland ecosystem of the Bolsa Chica lowlands. The project area covers about 1,247 acres, and has

restored tidal influence from the Pacific Ocean to about one-half of this area to reinvigorate the

wetland ecosystem. To achieve the biological benefits of tidal restoration, a direct connection to the

Pacific Ocean was reestablished through the creation of a new tidal inlet that cut through Bolsa Chica

State Beach and crossed the Pacific Coast Highway near the Huntington Mesa. Construction is

currently underway and is anticipated to span a total of 2.5 to 3 years, in order to avoid or minimize

impacts to fish and wildlife resources, coastal traffic, and beach recreation.

3.1.7 Huntington Beach Wetlands

The Huntington Beach Wetlands are located about 23 miles downcoast from the HGS, adjacent to the

Huntington Beach Generating Station. The total area of the wetlands is about 180 acres. Over the

years, the wetlands have been divided into a number of smaller parcels by the development of the

Huntington Beach area. The Huntington Beach Wetlands Conservancy plans to acquire the entire 180

acres and restore it in accordance with a comprehensive wetlands restoration plan that they are

currently preparing. Restoration will include the improvement or re-establishment of tidal circulation

within the wetlands. This will provide additional habitat for local fish and invertebrate species. In fall

2006, AES Huntington Beach was required to restore 66.8 acres of the Huntington Beach Wetlands to

offset entrainment losses for Units 3 and 4.

3.1.8 Upper Newport Bay Ecological Reserve

Newport Bay is located approximately 27 miles downcoast from the HGS. The Upper Newport Bay

Ecological Reserve was created in 1975 as result of the purchase of 527 acres of land in and around

the bay from the Irvine Company and the transfer of 214 acres of tidal wetlands from the County of

Orange to the state. An additional 11 acres of land in Big Canyon were added in 1982, bringing the

total acreage of the Ecological Reserve to 752 acres. It is managed by the California Department of

Fish and Game. There are currently a number of restoration projects within Upper Newport Bay. The

largest is the dredging of 2.1 million cubic yards of sediment. The project will restore and maintain

tidal movement within much of the Bay. Much of the dredging project still needs funding, as well as

post-project monitoring and maintenance. Dredging will provide additional habitat for fish species

already present in Upper Newport Bay.

3.2 COASTAL WATERSHED PROJECTS

Projects that control or reduce sediment transport into coastal wetlands may include erosion control

projects along upland watercourses; construction of catchment basins, swales, and other sediment

containment features; land acquisition for purposes of creating conservation easements; minimizing

runoff from development activities; restoration of floodplain habitat; and other Best Management

Practices. The implementation of watershed management projects as part of the restoration plan is

based on the nexus between the loss of wetland area and its associated reduction of biologically

productive habitat with the infilling of the wetlands by sediments eroded from its watershed.
Attachment B Addendum To The 316(B) Evaluation Of The Harbor Generating Station

7

3.2.1 Las Virgenes Creek Restoration Project

Las Virgenes Creek is an important tributary of Malibu Creek and Lagoon. Las Virgenes joins Malibu

Creek approximately 5.5 miles from the coast (Malibu Lagoon). The City of Calabasas plans to

remove over 250 linear feet of a concrete-lined portion of the creek to help restore the natural flow

and reduce sedimentation in the lower creek, and Malibu Creek and Lagoon. Stream banks will be

stabilized using a bio-engineered revetment and replanted with native vegetation.

3.3 PROJECTS TO ERADICATE NON-NATIVE PLANTS FROM WETLANDS

A number of projects have been proposed, or are underway, to eradicate non-native/invasive plants

from several of the creeks that feed the wetlands along the shore of Santa Monica Bay and areas to

the south. Plants like the Giant Reed (Arundo donax) clog waterways, increase sedimentation, and

consume large quantities of water. Removal of these plants can help restore flow within these coastal

creeks and marshes to historic levels. Non-native plant eradication programs are currently underway

in lower Topanga Creek, Malibu Creek, and Solstice Creek (a tributary of Malibu Creek).

3.4 NEARSHORE COASTAL PROJECTS

Projects for enhancing nearshore coastal areas include restoring degraded habitat such as kelp beds

and rocky intertidal areas, and projects that establish new habitat such as the construction of artificial

reefs. The increased biological productivity resulting from these projects can be weighed against the

IM&E losses associated with the operation of coastal generating stations.

3.4.1 Restoration of Natural Resources in Rocky Intertidal Habitats in

Santa Monica Bay

The UCLA Institute of the Environment currently has funding from the Santa Monica Bay

Restoration Commission (as part of the Santa Monica Bay Restoration Plan) for a project to identify

the causes of degradation of the intertidal habitats in Santa Monica Bay. The project will identify,

evaluate, and recommend practical restoration techniques for these habitats.

3.4.2 Kelp Restoration

Santa Monica Bay Keeper has an ongoing kelp bed restoration project that has been partially funded

as part of the Santa Monica Bay Restoration Plan. Historically, the rocky northern (Malibu area) and

southern (Palos Verde peninsula only about 10 miles upcoast of the HGS) portions of the bay were

once covered by dense kelp forests. Over the last 50 years the acreage of these beds has been greatly

reduced. Several kelp restoration projects, including the efforts of Santa Monica Bay Keeper, have

attempted, with some success, to return the kelp beds to their original extent. The techniques

employed include the removal of grazing herbivores (primarily sea urchins) and the introduction of

laboratory-reared kelp plants into areas where kelp coverage has declined. Kelp beds provide habitat

for numerous species of fish, invertebrates, and marine mammals. Increasing the size of the kelp beds

in Santa Monica Bay or the Palos Verde peninsula to the west of HGS, and the associated increase in

biomass that would accompany the restoration, could help offset IM&E losses due to operation of

coastal generating stations.

3.4.3 Artificial Reef

Several artificial reefs have been constructed along the coast of California, most notably the San

Clemente Artificial Reef (SCAR) that was built as part of the mitigation for the San Onofre Nuclear

Generating Station (SONGS) thermal discharge. SCAR was established in 1999 and its performance

has been monitored since that time. The artificial reef modules have provided new substrate for giant

kelp and other algae. The reef and its associated kelp canopy have, in turn, provided new habitat for

fish and invertebrates. Because of the location of the HGS in the LA-Long Beach Harbor Complex,
Attachment B Addendum To The 316(B) Evaluation Of The Harbor Generating Station

8

an artificial reef in the immediate vicinity of the facility is not an option. Construction of an artificial

reef outside of the immediate area of HGS is, however, worthy of consideration.

3.4.4 Restocking of Affected Fish Species

Hubbs-Seaworld Research Institute (HSWRI) operates aquaculture research facilities in southern

California and Florida. Since 1983, the HSWRI has bred, tagged, and released over 650,000 white

seabass into southern California waters. The institute has also bred and released other fish species,

and is assessing the feasibility of breeding rockfish. The technology developed by the institute, as part

of their Ocean Resources Enhancement Hatchery Program, could potentially be used to restock

species, although the 316(b) regulations discourage a hatchery replacement approach.

3.5 PRELIMINARY RANKING/EVALUATION OF RESTORATION PROJECTS

A set of selection criteria was developed for ranking the prospective habitat restoration projects

previously described, or any other comparable projects that might be considered for implementation.

They include:

Location Cost effectiveness

Nexus to IM&E effects Ability to measure performance

Basic need or justification for project Success of comparable restoration projects

Nature and extent of ecological benefits Time before benefits accrue

Stakeholder acceptance Technical feasibility

Administrative considerations Opportunities for leveraging of

funds/Availability of matching funds

Consistency with ongoing resource agency

work and environmental planning

Legal hurdles (e.g., permits, legal access)

Implementation costs Duration of benefits

Depending upon the nature of a particular project, the relative importance and weighing of these

criteria may vary. As a general proposition, however, projects will be selected so as to maximize the

offset of IM&E effects for compliance with 316(b), and secondarily to optimize ecological benefits to

Santa Monica Bay/San Pedro Bay, or adjacent offshore areas within the Southern California Bight.

This process will ensure that the most effective projects are assigned the highest priority.

A description of each of the criteria is provided below.

Location

Ideally, the location of the project is in the same source water/ receiving water bodies that are affected

by the operation of the facility. Scores decrease as the distance between the project area and those

waterbodies increases. Projects that involve waterbodies and watershed areas that feed into the

affected areas can have a high ranking, but are not ideal.

Nexustofacility’sIM&E effects

A project that enhances or replaces the species affected by the facility, in the waterbodies affected by

the facility would have the ideal nexus. As the project moves away from those species and locales, its

ranking decreases. The nexus is the relationship between the environmental impacts resulting from

the operation of the facility and the environmental benefits of the proposed project.
Attachment B Addendum To The 316(B) Evaluation Of The Harbor Generating Station

9

Basic need or justification for project

This category requires an evaluation of the need or justification for a proposed project. Restoration

projects that return wetland areas to their historic extent and replenish historic species that have been

depleted may be easily justified (high score). However, if the project requires that several blocks of

commercial property be razed to accommodate the project, it may require considerably more

justification. Other projects, like the establishment of artificial reefs where none formerly existed,

may be worthwhile, but will require some justification for their adoption (lowered score).

Technical feasibility

Is the technology or methodology utilized by the proposed project proven and effective? Has it, or

something similar, been used under similar conditions? Proven track record, or pie in the sky?

Stakeholder acceptance

Is the proposed project likely to have the support and approval of the regulatory agencies involved,

the owners and operators of the facility, and the local citizenry?

Nature and extent of ecological benefits

This is a category of magnitude. Does the project have a relatively narrow and limited ecological

benefit, such as increasing the population of a single species within a limited spatial context, or does

it benefit a large number of species (directly and indirectly) over an extensive area (higher ranking)?

Time before benefits accrue

If the proposed project is enacted, how much time will elapse before the benefits of the project

become evident? Projects that will demonstrate their resultant benefits in a short period of time will

rank higher in this category. However, projects that will have a large ecological benefit, but will

require an extended period of time to come to fruition, will offset their lower ranking in this category

with a higher ranking in the previous (nature and extent of ecological benefits) category.

Duration of benefits

Projects with environmental benefits that continue over a long period of time will receive a higher

ranking than those with short-term, transient, benefits. This category works in conjunction with the

two previous categories.

Success of comparable restoration projects

Thiscategoryissimilartothe“TechnicalFeasibility”category,butgoesastepbeyondfeasibilityto

the question of the success or failure of comparable projects. High rankings are given to projects that

are comparable to successful projects, low rankings are given to projects comparable with failed

efforts, and neutral rankings are given to projects lacking comparable examples (return to the question

of feasibility).

Consistency with ongoing resource agency work and environmental planning

Does the proposed project conflict with any ongoing resource agency work or environmental

planning? Projects without conflicts, that mesh well with ongoing projects and policy, will receive the

highest rankings. Projects that are inconsistent with current environment policy and ongoing projects

willreceivealowerranking(seealso“Basicneedorjustificationforproject”and“Legalhurdles”).
Attachment B Addendum To The 316(B) Evaluation Of The Harbor Generating Station

10

Legal hurdles (permitting, etc.)

In this category, projects that face significant legal hurdles, such as those that require extensive

permitting for their implementation, will receive lower ranking than those projects not hindered by

such requirements. The cost of overcoming these hurdles (time and money) should also be

incorporatedintotheevaluationoftheprojectinothercategories(“Implementationcost,”“Time

before benefits accrue,”and“Basicneedorjustificationforproject”).Providingadditionalfunding

for an ongoing project that has already passed these hurdles, would also receive a high ranking.

Implementation costs

This category is fairly straightforward, but requires some additional information about the magnitude

of the IM&E impacts to be offset for a proper evaluation of any potential project. The environmental

benefits accrued by a given project need to be weighed against the impacts that need to be offset

(“Cost/Benefit”).

Funding opportunities (matching funds, leveraging of funds, etc.)

Ongoing projects will do well in this category since they are already receiving at least some funding.

Many potential restoration projects have popular support, which can help with additional funding as

wellaslendingsupportincategorieslike“Basicneedorjustificationfortheproject,”“Stakeholder

support,”andeven“Legal hurdles.”Newer,moreinnovative,projectsmayhavefewerfunding

opportunities and would rank lower.

Ability to measure performance

Can the beneficial environmental effects of the proposed project be measured in some fashion that

relates to offsetting the impacts of the operation of the facility in question? Projects with more

qualitative, less tangible benefits would score lower in this ranking. Certain projects lend themselves

more easily to this category than others. The restocking of an area with fish can readily be assessed by

noting the number of fish introduced, the number surviving, the number reproducing, etc. Artificial

reefs and restored kelp beds can be surveyed to record species recruitment and the associated increase

in biomass. Restored wetlands may be more difficult to assess because of their complexity, including

terrestrial and aquatic habitats, nursery areas, birds, mammals, fish, and invertebrates, transient

species, etc. The performance of projects that restore watershed areas is even more difficult to assess

because of the indirect nature of many of their benefits to the areas directly impacted by IM&E

losses.

Cost / Benefit

How much bang-for-the-buck can be hard to gauge for many projects. The cost may be relatively easy

to calculate, but how do you measure all of the benefits of a project like the restoration of a historic

wetland(see“Abilitytomeasureperformance”)?Rankinginthiscategorymaybesomewhat

subjective with both the cost and benefits of a project placed somewhere along a gradient that ranges

from small to large.

Administrative considerations

How large are the administrative needs of a potential project. This includes taking the project through

any required approval/permitting process, implementing the project, and administering it through to

completion. Projects with limited need for oversight would score higher than projects requiring a

large administrative infrastructure.
Attachment B Addendum To The 316(B) Evaluation Of The Harbor Generating Station

11

Using a five point ranking system, each of the projects described in Section 3 was scored for the

criteria listed above. A ranking of 1 represents a very poor fit in any category; 5 an excellent fit. As

an example, a project located in Alamitos Bay, in very close proximity to HGS, would be ranked 5 for

its Location, but if it faced significant issues concerning regulatory permitting for the project, it might

rank a 2 for Legal Hurdles.

Rankings for the individual projects are shown in Table B-1. No rankings are provided for

Implementation Costs or Cost Effectiveness at this time, since the magnitude and duration of the

projects will be dependent upon the results of the LADWP IM&E studies.

An additionalaspectnotconsidered in the criterion of‘Opportunitiesforleveraging of

funds/Availabilityofmatchingfunds’isthepotentialforrestoration costs to be shared among the

power generating facilities located on the coast in Santa Monica Bay or in the larger Los Angeles

Basin coastal area. This would increase the scores for wetland projects in Orange County area that

are closer to the power generating facilities located in the Los Angeles/Long Beach Harbor Area and

facilities further south.

3.5.1 Results of Initial Rankings

The results of the initial ranking of projects indicate that the larger wetlands restoration, kelp bed

restoration, and artificial reef projects would be the most suitable for further evaluation. The projects

with the highest ranking were the Ballona Wetlands, upper Newport Bay, the Bolsa Chica Lowlands,

and the Huntington Beach Wetlands projects. Located about 20 miles upcoast from HGS, the Ballona

Wetlands project also scored highly because it is located only 4 miles upcoast of another LADWP

power plant, SGS, and is the only remaining large coastal wetland in Los Angeles County. In

contrast, the Los Cerritos Wetlands, located only 12 miles downcoast of the HGS, did not score as

high because of multiple zoning issues and the presence of large quantities of hazardous materials that

were disposed in the area in the past. These projects, or other wetland projects, could be combined

with one of the open coastal projects such as the establishment of an artificial reef to provide

restoration credits for both estuarine and coastal species.
Attachment B Addendum To The 316(B) Evaluation Of The Harbor Generating Station

12

TABLE B-1.

QUALITATIVE RANKING, WITH 1 BEING LOWEST AND 5 BEING HIGHEST, OF POTENTIAL RESTORATION PROJECTS FOR OFFSETTING

HARBOR GENERATING STATION IM&E LOSSES.

RESTORATION PROJECT ZUMA

WETLANDS

MALIBU

LAGOON

TOPANGA

LAGOON AND

CREEK

BALLONA

WETLANDS

LOS

CERRITOS

WETLANDS

BOLSA CHICA

LOWLANDS

HUNTINGTON

BEACH

WETLANDS

UPPER

NEWPORT

BAY

LAS

VIRGENES

CREEK

NON-NATIVE

PLANT

ERADICATION

SANTA MONICA

BAY ROCKY

INTERTIDAL

SANTA MONICA

BAY KELP BEDS

ARTIFICIAL

REEF

EVALUATION CRITERIA

Location 3 3 3 3 4 4 4 3 2 2 3 3 3

Nexus to HGS Impacts 3 3 3 4 4 4 4 4 3 3 3 3 3

Basic Need or Justification For

Project 2 4 3 5 4 4 4 5 3 3 3 4 3

Nature and Extent of Ecological

Benefits 2 3 2 5 4 3 3 4 2 2 3 5 5

Stakeholder Acceptance 5 5 5 5 5 5 5 5 5 5 5 5 4

Administrative Considerations 4 4 4 4 3 4 4 4 4 4 2 3 2

Consistency With Ongoing

Resource Agency Work and

Environmental Planning 5 5 5 5 5 5 5 5 5 5 4 5 4

Implementation Costs No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data

Cost Effectiveness No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data

Ability to Measure Performance 3 3 3 4 4 4 4 4 2 2 2 3 5

Success of Comparable Projects 3 3 3 4 4 4 4 4 3 3 2 3 5

Time Before Benefits Accrue 3 3 3 3 3 3 3 3 2 2 2 4 4

Technical Feasibility 3 3 3 4 3 4 4 4 3 3 2 3 5

Funding Opportunities

(matching funds, leveraging of

funds) 4 4 4 4 4 4 4 4 4 4 4 4 3

Legal Hurdles (permitting, etc.) 4 4 4 4 3 4 4 4 4 4 3 4 2

Duration of Benefits 3 3 3 5 5 5 5 5 3 3 3 3 5

TOTAL 47 50 48 59 55 57 57 58 45 45 41 52 53
Attachment B Addendum To The 316(B) Evaluation Of The Harbor Generating Station

13

4.0 CONCLUSIONS AND RECOMMENDATIONS

An initial screening of potential projects in the vicinity of the LADWP power plants using the set of

criteria described in this report was used to determine that wetlands restoration, kelp bed restoration,

and artificial reef projects would be the most suitable for further evaluation. Restoration projects

associated with the Ballona Wetlands, Bolsa Chica Lowlands and Huntington Beach Wetlands

received the highest rankings using the criteria previously described. Although located almost 20

miles upcoast of HGS, the Ballona Wetlands scored highly because they are located only 4 miles

upcoast from another LADWP facility, SGS, and they are the only remaining large coastal wetlands

in Los Angeles County. There are active groups involved with the preservation of the wetlands and

acquisition of additional lands to expand the wetlands to its historical boundaries. These groups and

projects associated with the Ballona Wetlands provide opportunities for funding similar to the

approach used at Elkhorn Slough for the Moss Landing Power Plant, where money was transferred to

the Elkhorn Slough Foundation for the expansion and preservation of wetland habitat that offset

entrainment losses from the power plant.

The proposed restoration of the Los Cerritos Wetlands, 12 miles downcoast of the HGS, has the

potential to be a viable restoration option for any or all of the LADWP facilities. However, as cited in

the final report of the City of Long Beach, Los Cerritos Wetlands Study Group (available as a

downloadable pdf file at http://www.longbeach.gov/plan/pb/cpd/los_cerritos.asp), there are several

pressing issues that need to be dealt with prior to proceeding with any of the proposed restoration

projects. These issues include the numerous and varied zoning and jurisdictional concerns related to

theareaoftheformerwetlands,andthearea’shistoryofuseasahazardous waste disposal site. These

concerns were reflected in the lower ranking of this restoration option in comparison with the Ballona

Wetlands.

A major wetlands restoration project at a location like the Ballona Wetlands could be supplemented

with a coastal project to compensate for losses to marine coastal fishes. The projects that received the

highest ranking using the criteria in this report were kelp ked restoration and artificial reefs. The

SONGS is using an artificial reef as mitigation for the effects of the thermal discharge on kelp beds

and associated communities. Studies at a pilot-scale artificial reef being used in the design of the final

full-scale project show that the artificial reef is performing similar to natural reefs in the area.

Development of giant kelp (Macrocystis spp.) on an artificial reef would provide the added benefit of

increasing the area of kelp habitat, an important habitat-forming community in the nearshore areas at

the north and south headlands of Santa Monica Bay. Kelp beds provide habitat for a wide variety of

invertebrates and fishes. An artificial reef project in Santa Monica Bay benefits from all of the work

that has been completed for the SONGS reef project. It is also relatively easy to demonstrate the

benefits from an artificial reef, since the SONGS project has shown that communities develop fairly

rapidly on the new habitat.
Attachment C Addendum To The 316(B) Evaluation Of The Harbor Generating Station

1

ATTACHMENT C -

VELOCITY CALCULATIONS

The following is a summary of HGS velocity calculations.

DATA:

Flow (Q): 167 cfs

Water Elevation: El. 0.0 ft

Trash Rack Width: 56 ft

Trash Rack Invert: El. -21.5 ft

Top of Trash Rack: El. -11.0 ft

Intake Pipe Internal Diameter: 8.0 ft

Intake Pipe Area: 50.2 ft2

Number of Intake Pipes: 2

Number of Bays: 4

Screen Width: 6.2 ft

Screenhouse Invert: El. -16.0 ft

FORMULA USED:

( )

( )

( )

A area

Q flow V velocity 

CALCULATIONS:

0.3 /sec

56* ( 11.5 21.5 )

167 ( ) ft

ft ft

cfs V trashrack 

 



1.7 /sec

2 *50.2

167 ( )

2

ft

ft

cfs V Intakepipes  

0.8 /sec

2 * 6.2 * (0.0 16.0 )

167 (2 ) ft

ft ft ft

cfs V screens 





0.4 /sec

4 * 6.2 * (0.0 16.0 )

167 (4 ) ft

ft ft ft

cfs V screens 




Attachment D Addendum To The 316(B) Evaluation Of The Harbor Generating Station

1

ATTACHMENT D -

FISH MORPHOMETRY AND SCREEN MESH HEADLOSS

The following information on fish morphometry was developed by LMS as part of a NJPDES Permit

specialconditionforPSEGServicesCorporation’sSalemGeneratingStation5.

This study was designed to use physical measurements from preserved ichthyoplankton to compute

the expected size of larval fish retained by plankton nets of various mesh sizes. “...Expectations of

the size of organisms to be retained by a given mesh size can be developed from the physical

dimensions of the organism. This may be done by first relating the greatest cross-sectional dimension

(such as skull width or other measures of body girth) to overall fish length. Then, the greatest mesh

dimension is computed, typically the mesh diagonal. Smith et al. (1968) found that the maximum

cross-sectional diameter of the organism must be greater than the mesh diagonal if it is to be fully

retained. For a given cross-sectional diameter and associated standard deviation, the percentage

retained and excluded is calculated by integration under a normal curve. Examples of this type of

analysis may be seen in Vannucci (1968), Lenarz (1972), Colton et al. (1980), Turnpenny (1981),

Schneeberger and Jude (1981) among others. Results of this analysis may then be used to develop

working guidelines for the minimum size necessary for retention of each species....”The only

exception is the data for naked goby, which were developed from scale-drawings by Alden using the

LMS model. The reported entrainment and impingement probabilities are for 0.5 mm mesh screens

and are provided as an illustration of the effect of length/head capsule depth (HCD) on entrainment

and impingement. The reported HCD at body length was used to predict the HCD for HGS species.

The series 3 and 4 categories refer to entrainment and impingement, respectively.

The screen mesh/headloss assessment was prepared by Alden with data provided by Johnson Screens

and Siemens Screens.

5

Public Service Enterprise Group. (2002). Salem Generating Station, NJPDES Permit #NJ0005622,

Custom Requirement G.9.b.ii, Entrainment Extrusion Study, Task #1, Morphometric Analysis.
Attachment D Addendum To The 316(B) Evaluation Of The Harbor Generating Station

2

Atlantic Silverside

Eggs:

Probability Probability

Entrainment Impingement

0.00000000 1.00000000

Larvae

length ln(length) ln(HCD) HCD Probability Probability

(mm) (mm) Entrainment Impingement

1 0 -2.17238 0.113907 1 0

2 0.6931472 -1.47022 0.229876 1 1.9867E-12

3 1.0986123 -1.05948 0.346636 0.99946385 0.00053615

4 1.3862944 -0.76806 0.463913 0.74820565 0.25179435

5 1.6094379 -0.54201 0.581576 0.08860428 0.91139572

6 1.7917595 -0.35732 0.699547 0.00135686 0.99864314

7 1.9459101 -0.20117 0.817775 5.5983E-06 0.9999944

8 2.0794415 -0.0659 0.936224 1.0692E-08 0.99999999

9 2.1972246 0.053413 1.054866 1.3169E-11 1

10 2.3025851 0.160144 1.17368 1.2815E-14 1

11 2.3978953 0.256693 1.292648 1.1191E-17 1
Attachment D Addendum To The 316(B) Evaluation Of The Harbor Generating Station

3

Atlantic croaker

Eggs:

Probability Probability

Entrainment Impingement

0.00354797 0.99645203

Larvae

length ln(length) ln(HCD) HCD Probability Probability

(mm) (mm) Entrainment Impingement

1 0 -1.9015 0.149345 1 0

2 0.6931472 -1.1023 0.332107 1 4.5773E-12

3 1.0986123 -0.6348 0.530043 0.16540446 0.83459554

4 1.3862944 -0.3031 0.738525 3.9953E-11 1
Attachment D Addendum To The 316(B) Evaluation Of The Harbor Generating Station

4

Bay anchovy

Eggs:

Probability Probability

Entrainment Impingement

0.00007334 0.99992666

Larvae

length ln(length) ln(HCD) HCD Probability Probability

(mm) (mm) Entrainment Impingement

1 0 -1.69755 0.183132 1 3.5926E-10

2 0.6931472 -1.2165 0.296265 0.99933809 0.00066191

3 1.0986123 -0.93511 0.392543 0.9311524 0.0688476

4 1.3862944 -0.73546 0.479286 0.60240373 0.39759627

5 1.6094379 -0.5806 0.559565 0.24494069 0.75505931

6 1.7917595 -0.45406 0.635041 0.07122037 0.92877963

7 1.9459101 -0.34708 0.706746 0.01687337 0.98312663

8 2.0794415 -0.25441 0.775371 0.00355533 0.99644467

9 2.1972246 -0.17267 0.841413 0.00070377 0.99929623

10 2.3025851 -0.09955 0.905243 0.00013543 0.99986457

11 2.3978953 -0.03341 0.967145 2.5885E-05 0.99997411

12 2.4849066 0.026979 1.027346 4.982E-06 0.99999502

13 2.5649494 0.152558 1.16481 1.0607E-07 0.99999989

14 2.6390573 0.281506 1.325124 1.1194E-09 1

15 2.7080502 0.401553 1.494144 9.342E-12 1

16 2.7725887 0.51385 1.671716 6.5628E-14 1

17 2.8332133 0.619337 1.857696 4.0709E-16 1

18 2.8903718 0.718793 2.051955 2.3135E-18 1
Attachment D Addendum To The 316(B) Evaluation Of The Harbor Generating Station

5

Atlantic menhaden

Eggs:

Probability Probability

Entrainment Impingement

0.00000000 1.00000000

Larvae

length ln(length) ln(HCD) HCD Probability Probability

(mm) (mm) Entrainment Impingement

1 0 -0.46918 0.625518 0.03208407 0.96791593

2 0.6931472 -0.18776 0.828816 1.4783E-05 0.99998522

3 1.0986123 -0.02314 0.977127 1.5362E-08 0.99999998

4 1.3862944 0.093661 1.098187 3.9487E-11 1

5 1.6094379 0.184257 1.202325 2.0644E-13 1

6 1.7917595 0.258279 1.2947 1.8748E-15 1

7 1.9459101 0.320865 1.378319 2.6405E-17 1
Attachment D Addendum To The 316(B) Evaluation Of The Harbor Generating Station

6

Naked goby

Eggs:

Probability Probability

Entrainment Impingement

0.00000000 1.00000000

Larvae

length ln(length) ln(HCD) HCD Probability Probability

(mm) (mm) Entrainment Impingement

1 0 -1.40758 0.244734 1 1.5477E-13

2 0.6931472 -0.82465 0.43839 0.9101756 0.0898244

3 1.0986123 -0.48365 0.616528 0.01626992 0.98373008

4 1.3862944 -0.24171 0.785284 2.0475E-06 0.99999795

5 1.6094379 -0.05405 0.947388 3.4819E-11 1

6 1.7917595 0.099286 1.104382 3.0815E-16 1

7 1.9459101 0.228926 1.25725 2.5064E-21 1
Attachment D Addendum To The 316(B) Evaluation Of The Harbor Generating Station

7

Wire-mesh screen head loss characteristics

Assumptions for head loss calculations:

Screen approach velocity at 1 feet/sec

Through-flow screen (two screen mesh baskets in flow path)

Head loss coefficients from M. Papworth 1972

Screen characteristics:

Screen

Mesh

Wire

spacing

(in)

Wire

dia.

(in)

Wire

dia.

(mm)

opening

(mm)

Open

area

Backup

screen

(1"

mesh)

combined

open area

with 1" backup screen

3/8" mesh 0.444 0.08 2.0 9.3 67% no 67%

10 mesh 0.100 0.025 0.64 1.9 56% yes 45%

18 mesh 0.056 0.017 0.43 1.0 48% yes 39%

30 mesh 0.033 0.012 0.30 0.5 41% yes 33%

50 mesh 0.020 0.009 0.23 0.3 30% yes 24%

70 mesh 0.014 0.0065 0.17 0.2 30% yes 24%
Attachment D Addendum To The 316(B) Evaluation Of The Harbor Generating Station

8

LITERATURE CITED

Colton, J.B., Jr., J.R. Green, R.R. Byron, and J.L. Frisella. 1980. Bongo net retention rates as

effected by towing speed and mesh size. Can. J. Fish. Aquat. Sci. 37:606-623.

Lenarz, W.H. 1972. Mesh retention of Sardinops caerulea and Engraulis mordax by plankton nets.

Fish. Bull. U.S. 70:839-848.

Schneeberger, P.J. and D. J. Jude. 1981. Use of fish larva morphometry to predict exclusion

capabilities of small-mesh screens at cooling-water intakes. Trans. Amer. Fish. Soc. 110:246-252.

Smith, P.E., R.C. Counts, and R.I. Clutter. 1968. Changes in filtering efficiency of plankton nets

due to clogging under tow. J. Cons. perm. int. Explor. Mer.32: 232-248.

Turnpenny, A.W.H. 1981. An analysis of mesh sizes required for screening fishes at water intakes.

Estuaries, 4(4):363-368.

Vannucci, M. 1968. Loss of organisms through the meshes. In D.J. Tranter (ed.), Part I, Review on

zooplankton sampling methods, p. 77-86. UNESCO Monograph. Oceanography. Methodology. 2,

Zooplankton Sampling
Attachment E Addendum To The 316(B) Evaluation Of The Harbor Generating Station

9

ATTACHMENT E -

POTENTIAL FISH RETURN CLEANING SYSTEMS

Fish and debris removed from fine-mesh traveling water screens with fish protection or MIS modules

would have to be conveyed back to the harbor. To prevent re-impingement, the return line will have

totransportfishanddebristotheL.A.Harbor’sWestBasinviaa 1,400-foot-long return pipe. This

return location was selected as returning fish to the discharge pipe, the current procedure, is expected

to increase mortality due to thermal stress. Once removed from the screens, fish and debris would

flow into a pipe that would parallel the existing warm water return line. Additional water would need

to be added to the return line to provide the fish removed from the screens a 6 inch water cushion. A

pipe was selected as the area surrounding HGS is heavily industrialized and the pipe would most

likely have to be buried.

Cleaning of the trough both near the screens and within the tidal area would be fairly easy and could

be conducted by plant personal using either brushes or a high-pressure spray. Alden has identified

two options for cleaning the pipe portion. These options are: a heat treatment or two return pipes

which would be used on an alternating basis to allow drying of the pipes. The constraints and

benefits of each option are listed in the following table.

Criteria Heat Treatment Two Pipes

Construction Concerns The existing discharge lines

would need to be tapped. A

pump would be required to

transport water to the return

line.

Twice as much pipe with

isolation valves.

Construction Impacts on Plant

Operation

Would require a unit to be

shutdown while the discharge is

tapped. Could be completed

during a scheduled outage.

None.

Impacts on Plant Operation Heat treatments would need to

be timed to coincide when units

are operating at maximum inlet

temperature and plant output.

None.

Impacts on Screen Operation None. None.

Impacts on Survival No survival during heat

treatment.

None.

Reliability If return pipe or hot water line

fails there is no redundancy.

If one return pipe fails, the

second one can be brought into

operation rapidly.

Installation Cost1$278,000 $337,000

O&M Costs1$18,000 $19,000

1. Costs are in 2006 and are based on the same assumptions as the costs in the cost section of this

Addendum

The same methods used to clean the fish return for the modified traveling screen options would be

applicable to the fish return required for Modular Included Screens. The fish return pipe for the MIS

would be the same length as the traveling screen return but would require a larger piper, to

accommodate the required bypass flow. The preceding table is valid for MIS return, except for the

costs. For the MIS return system the cost for both cleaning options would be very similar but higher

than those in the table.