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American Fisheries Society 141st Annual Meeting

Symposium

Protecting Fish at Power Plant Cooling Water Intakes:

New Developments and Science on Clean Water Act §316(b)

September 5-6, 2011

Summary

This symposium was conducted over a two day period during the 141st American Fisheries 

Society (AFS) Meeting in Seattle, Washington. The symposium was sponsored by the AFS 

Bioengineering Section. The Monday, 5 September session started at 1:15 PM with an 

introduction and presentation by Doug Dixon (EPRI) on the draft 316(b) rule for existing 

facilities. The first session ended at 5:15 PM, and the symposium resumed at 8:00 AM on 

Tuesday and continued until 3:00 PM. There were a total of 37 platform presentations. 

Although it is somewhat difficult to categorize all presentations, the majority focused on intake 

technologies, impingement/entrainment surveys, source water surveys, and economic benefits. 

Most speakers were representing engineering/consulting firms or utilities. All presentation 

abstracts are provided below, as are summaries of topics and speakers.

Presentation Topic Summary

Topic Number of 

Presentations

Technologies (fish protection/return) 16

Impingement/Entrainment Surveys (local or cumulative) 5

Source Water Surveys 4

Economic Benefits (or cost-benefit) 4

Draft 316(b) Rule 3

Closed Cycle Cooling Perspectives 2

Entrainment Survival 1

Adverse Environmental Impact 1

Climate Change 1

Speaker Summary

Speaker Number of 

Presentations

Consulting or Engineering Firms 24

Utility Companies 7

Electric Power Research Institute 2

Alden Research Laboratory 2

Government Agencies (Nuclear Regulatory Commission) 1

Legal Firms 1
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Protecting Fish at Power Plant Cooling Water Intakes:

New Developments and Science on Clean Water Act §316(b),

Part 1

Introduction

The U.S. Environmental Protection Agency (EPA) on April 20, 2011 released a proposed rule 

for public comment implementing technology-based standards for fish protection at existing 

power plants and other facilities that use cooling water in accordance with the requirements of 

§316(b) of the Clean Water Act. This regulatory action affects almost 1,300 facilities (power 

plants, pulp and paper mills, iron mills, chemical plants) around the U.S. that use cooling water. 

These industries, federal and state regulatory and resource agencies, non-governmental 

organizations and the public will all need the latest information on technologies and related 

information for protecting fish and shellfish at cooling water intakes – this includes traveling and 

fixed screens, barrier nets, behavioral systems, closed cycle cooling systems, and other 

methods for reducing, excluding or collecting and returning fish and shellfish to source water 

bodies. Information will also be needed on methods for characterizing impingement and 

entrainment and for determining the performance of technologies. Methods for economic 

analysis to determine the cost-benefit for compliance activities may also be needed. This 

symposium will gather practitioners with expertise in fish protection/bioengineering at cooling 

water intakes to present and discuss the latest scientific developments in this field. 

Overview of Draft EPA 316(b) Rule for Existing Facilities 

Monday, September 5, 2011: 1:15 PM

Douglas A. Dixon, Electric Power Research Institute, Gloucester Point, VA 

David Bailey, Electric Power Research Institute, Springfield, VA 

The U.S. Environmental Protection Agency (EPA) is developing a revised regulation to 

implement the fish and shellfish protection requirements of Section 316(b) of the Clean Water 

Act. The regulation will specify technology-based performance standards for existing facilities 

that use surface water for cooling. This will primarily affect the electric power industry; however, 

pulp and paper, iron and steel and other manufacturing operations that utilize surface water for 

some level of cooling will also be affected. A draft Rule for public review and comment is 

expected March 14, 2011 (after posting of this abstract) and the final rule July 27, 2012.

Technology-based performance standards will be issued for reducing impingement (entrapment 

of fish and shellfish on intake screens) and entrainment (passage of eggs, larvae, and juvenile 

fish and shellfish through cooling systems). The standards may be applicable according to 

several factors including but not limited to the water flow volume withdrawn, plant capacity 

utilization, and plant location on sensitive water bodies. The standards will require in-scope 

facilities to install technologies to attain the fish protection requirements. Applicable 

technologies can exclude organisms, reduce their number, or collect and safely return them to 

the source water body. Example technologies include behavioral systems, barrier nets, 

traveling water screens, cylindrical wedge wire screens and, the most expensive approach, 

retrofits of closed cycle cooling systems (cooling towers. This presentation will review the full 

scope of the regulation that is proposed by EPA in March 2011.
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Installation, Operation, and Performance of the Gunderboom® Marine Life Exclusion 

System at Cooling Water Intakes 

Monday, September 5, 2011: 1:30 PM

Thomas L. Englert, Ferm, HDR Engineering Inc., Pearl River, NY 

Andrew J. McCusker , Gunderboom, Inc., Scarborough, ME 

William D. Saksen , Ferm, HDR Engineering Inc., Pearl River, NY 

John A.D. Burnett , Ferm, HDR Engineering Inc., Park City, UT

Electric utilities and other industries that withdraw water for cooling purposes are under 

increasing pressure from state and federal regulatory agencies to reduce losses of fish due to 

entrainment and impingement. New draft regulations from USEPA scheduled to be published in 

March 2011 may require reductions in losses of 80% or more. The Gunderboom Marine Life 

Exclusion SystemTM (MLESTM), a full-water-depth filter barrier that effectively limits aquatic biota 

from entering cooling water intake structures may provide such reductions. The technology was 

developed during a six year (1995-2001) research and development program conducted at the 

Lovett Generating Station, having a once-through flow of 465 MGD and located on the lower 

Hudson River. Seasonal deployments, scheduled to coincide with the presence of fish eggs 

and larvae, were used to develop and improve the technology. Resulting design changes 

increased the flow- through capacity of the fabric, and incorporated an automated Air-BurstTM 

cleaning system, and improved anchor system that allowed operation of the MLESTM under 

extreme flow and weather conditions. Ichthyoplankton monitoring was conducted during the 

program to measure the system’s effectiveness at reducing entrainment. Paired samples were 

collected at protected (i.e. within the MLESTM) and unprotected intakes during 1995, 1998, 2000 

and 2004 through 2007. Results from the ichthyoplankton monitoring program indicate that the 

Gunderboom MLESTM was greater than 80% effective at reducing entrainment. Results of the 

monitoring studies are discussed along with some specialized studies to measure the potential 

for impingement of organisms on the filter fabric. These studies have potential implications for 

other technologies as well, such as fine slot wedgewire and travelling screens. Effectiveness of 

the filter fabric technology is compared to other technologies and a current installation of the 

MLESTM on the Taunton River in MA, in its fourth year of operation, is described. 

Evaluation of an Angled Intake Structure at a Once-Through Cooled Power Plant 

Monday, September 5, 2011: 1:45 PM

Robert H. Reider, DTE Energy, Detroit, MI 

Matthew Thomas, Golder Associates Inc., Tampa, FL 

Darlene Ager, Kinectrics Inc., Toronto, ON, Canada

The Belle River Power Plant (BRPP) is a 1270 MW, two-unit, base-load, coal-fired facility 

located on the west side of the St. Clair River approximately 46 miles north of Detroit in St. Clair 

County, MI. The plant utilizes a once-through cooling water system with a shoreline intake 

structure. The design of the cooling water intake structure was based on a review of available 

fish protection technologies at facilities located on flowing water and on hydraulic modeling 

studies with the objective of minimizing fish entrapment. Features include an intake structure 

angled 20 degrees relative to the river flow, flush mounted traveling screens to eliminate 

embayments, guide vanes to enhance parallel water flow and a design approach velocity of 

15.2 cm/s. Impingement and entrainment sampling was conducted in 2005-2006 at BRPP and 
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at an adjacent facility that could be considered a calculation baseline facility (CBF) per USEPA 

316(b) Phase II Rule criteria. In comparing the sampling results at the two facilities there were 

reductions in fish impingement of 96.9% in total number and 99.4% in total biomass at BRPP 

when compared with the CBF. In terms of impingement density (number per unit volume of 

water pumped by plant) the reduction was 97.7%. Total entrainment of larval and juvenile fish 

showed a 96.4% reduction at BRPP when compared with the CBF. In terms of larval and 

juvenile density the reduction was 97.8%. These reductions in impingement and entrainment 

exceed the performance standards identified in the 2004 316(b) Phase II rule. 

Integrated Fish Protection System to Address Entrainment and Impingement 

Monday, September 5, 2011: 2:00 PM

Paul Patrick, Kinectrics Inc., Toronto, ON, Canada

Extensive research has been conducted on various fish protection systems in an attempt to 

reduce both entrainment and impingement. Since the technology for impingement reduction is 

often different from entrainment technologies, integrated systems are often used as retrofit 

designs to address the different life history stages of fish, notably larvae, juvenile and adult fish. 

The proposed system at BayShore involves a unique “reversed” louver array to address 

impingement and debris (and to a lesser extent entrainment), fine mesh screens in the 

pumphouse to address entrainment and residual impingement, and a fish return system 

involving fish pumps and a transport system. The “reversed” louver array is critical as the initial 

component of the proposed fish diversion system and includes specific design features such as 

frame angle, slat angle, slat length, slat spacing and a bottom overlay. The primary function of 

the louver is to divert juvenile and adult fish which may eventually become impinged on the 

traveling screens. Another function of the louver is to divert or minimize debris so that less 

material ends up on the traveling screens. Fine mesh screens are another critical component of 

the integrated system at BayShore. It’s main function is to divert organisms which include eggs 

and larvae unharmed towards the transport system. The final component of the integrated 

system is a fish pump and transport system. Factors considered important include location, type 

of pump, size, impeller speed, expected fish densities, sweep velocity along louver to pump, 

attraction velocity (if required), and quantity of flow. A pilot project was carried out in the field 

from April to October 2010 on the louver array, and a fine mesh screen component. Results on 

entrainment, impingement and biofouling will be presented including a discussion of how the 

proposed unique system will operate at the BayShore Plant. 

The Use of a Porous Dike Structure for Reducing Fish Impingement at a Power Plant 

Employing Once-Through Cooling 

Monday, September 5, 2011: 2:15 PM

David T. Michaud, We Energies, WI

In 2000, We Energies announced its intent to repower its Port Washington Power Plant site. 

The historic 380 MW coal-fueled plant was to be replaced with a two unit, natural gas-fueled 

combined cycle plant. Both the historic and new plant would have similar cooling water supply 

needs (814 MGD, or 565,000 gpm). Following a rigorous review of alternatives, the company 

selected, based on previous successful use at a now decommissioned station, a porous dike to 

enclose the existing intake channel to reduce impingement of trout and salmon. Engineering 
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and hydraulic testing studies were conducted to assure that the proposed structure could both 

supply the required cooling water flow and withstand waves generated by storm events. 

Construction was initiated in May, 2008 and was completed by the end of September, 2008. A 

two-year biological (impingement and entrainment monitoring) and operational performance 

evaluation study commenced in January, 2009 and was completed in December, 2010. 

Performance thus far, has been excellent. Initial operational / biological observations, to date, 

suggest that: (1) dislodged Cladophora, which caused forced outages in the past, has been 

substantially reduced; no forced outages have occurred since the dike was placed into service; 

(2) cooling water supply has not been impacted by winter icing conditions; (3) approach velocity 

measurements near the face of the dike confirm predictions (e.g., near ambient lake conditions; 

(4) winter impingement of gizzard shad has been virtually eliminated; summer impingement of 

alewife has also been substantially (e.g. greater than 90%) reduced; and (5) results of 

entrainment monitoring have not yet been concluded. 

AquaSweepTM Separator Inertial Separation – An Alternative to Screening of Aquatic 

Life and Closed Loop Cooling Tower Retrofit to Meet 316(b) Requirements 

Monday, September 5, 2011: 2:30 PM

Brian R. Murphy, C-Water Technologies, Inc., Evergreen, CO

The protection of aquatic life from impingement and entrainment (IM&E) by power plant cooling 

water intake structures (CWIS) has been a topic of study and implementation for several 

decades. A wide array of screening techniques have been employed with varying degrees of 

success. While IM&E reductions approaching 90% for “large” aquatic organisms such as adult 

fish have been successfully demonstrated by a number of technologies – IM&E reductions for 

small aquatic organism such as eggs and larvae in an economical and maintainable fashion has 

been more elusive. 

Section 316(b) final draft regulation by the EPA is schedule for publication in March 2011 with 

enactment in July 2012. This regulation is anticipated to have a significant impact on the power 

generation industry by requiring reductions in IM&E of once through cooling (OTC) intakes to 

levels that have only been demonstrated by closed cycle cooling towers (CCCT). The cost of 

converting existing U.S. power plants which use OTC to CCCT has been estimated at more 

than $100 billion. 

The AquaSweep Separator is based on the principle of inertial separation – not screening – to 

separate small aquatic life from the CWIS. By definition, screening requires the largest “hole” in 

the screen to be smaller than the smallest aquatic organism being excluded. Inertial separation 

relies on the inertia of the aquatic life to guide it away from the water flow entering the CWIS. By 

employing inertia, the largest “hole” in the AquaSweep Separator can be larger than the 

smallest aquatic life being excluded. A direct benefit is a smaller cross sectional area of active 

separator face when compared to the active screen face required for other technologies. In 

addition to AquaSweep’s benefits of a smaller footprint, its larger “holes” are less likely to clog 

with debris and are easier to clean given their linear geometry. 

This presentation will show the footprint, conversion cost, and maintenance benefits of the 

AquaSweep separator when compared with screening technologies and CCCT conversion. 

Computational fluid dynamics modeling by CH2M Hill and aquatic life studies performed by 

Alden Research Laboratory results will also be presented. 
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Velocity Cap Effectiveness at Scattergood Generating Station (Los Angeles, CA) 

Monday, September 5, 2011: 2:45 PM

D. Shane Beck, MBC Applied Environmental Sciences, Costa Mesa, CA 

Eric Miller, MBC Applied Environmental Sciences, Costa Mesa, CA 

John Hedgepeth, Tenera Environmental, San Luis Obispo, CA 

John R. Steinbeck, Tenera Environmental, San Luis Obispo, CA

Velocity caps are used at many coastal power plants in southern California to reduce the 

amount of fish entrained into cooling water intake systems. Historical laboratory and field 

studies indicated velocity caps reduced fish entrapment by >80%. Field studies were conducted 

at the Los Angeles Department of Water and Power’s Scattergood Generating Station in 2006-7 

to estimate the entrapment reduction resulting from use of the velocity cap. To determine 

velocity cap effectiveness, impingement samples were collected during periods with the 

generating station operating in normal flow, where cooling water was withdrawn from the intake 

structure with the velocity cap, and in reverse flow, where cooling water was withdrawn from the 

discharge structure without the velocity cap. Hydroacoustic surveys were conducted during day 

and night in both normal and reverse flow conditions to determine if there were any significant 

differences in nearshore fish densities between the intake and discharge structures. The 

Scattergood velocity cap reduced fish impingement abundance by 97.6%, and fish impingement 

biomass by 95.3%. No significant differences in fish densities were detected between the intake 

and discharge structures, indicating differences were attributable to the use of the velocity cap. 

NEPTUN: The Electronic Barrier That Effectively Repels Fish From Surface Water 

Intakes and Manages Fish Movement in a Down and Upstream Waterway 

Monday, September 5, 2011: 3:30 PM

Piotr Parasiewicz, Fishways Global, LLC, Livonia, MI 

The protection of fish communities at man-made facilities and barriers has a long history of 

significant expenditure of scientific and monetary resources. Beyond creating fishways, 

considerable investment is made to protect fish by blocking their access to turbines, water 

intakes, and directing them to less risky areas. The anticipated success of electrical fish barriers 

and guidance structures has been limited due to current design limitations. However, a device 

with a fundamentally new design feature has been successfully deployed in Poland. The device 

is called "NEPTUN." NEPTUN is an electric-electronic 3-phase barrier, producing a smooth nonuniform pulsed electric field of low voltage. It uses arrays of positive and negative electrodes 

and gradually increases the intensity of the electric field between the electrodes from positive to 

negative. Unlike other devices NEPTUN does not stun fish, but affects their neuromuscular 

system at the informational level, allowing them to escape from the area of the electric field. The 

basic field installation consists of steel electrodes attached to the river bottom so that they can 

move from the vertical to an angle of + / - 90 degrees. A buoy attached at the end of the 

electrode keeps it in an upright position. Groups of electrodes are powered by remotely 

controlled generators. Specialized software controls the parameters of the electric field, creates 

statistically-mastered changes, and controls the switching of each group of electrodes. The 

system supports sensors for monitoring temperature and conductivity of the water which can be 

used to automatically adjust the properties of the electric field. With an average power input of 
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0.43 to 0.45 kWh and electricity consumption of 0.0018 kW/m2, "NEPTUN" has a low operating 

cost. Additionally, the system maintenance is minimal. 

Laboratory Evaluations of Fine-mesh Traveling Screens – 5 Years of Research 

Monday, September 5, 2011: 3:45 PM

Jonathan Black, Alden Research Laboratory, Inc., Holden, MA 

Daniel Giza, Alden Research Laboratory, Inc., Holden, MA 

Brian McMahon, Alden Research Laboratory, Inc., Holden, MA 

Douglas A. Dixon, Electric Power Research Institute, Gloucester Point, VA 

Biological performance – primarily the 48-hour survival of collected larvae – was evaluated in 

the laboratory with fine-mesh traveling screens. The first year of testing used small acrylic, 

tabletop, flumes to evaluate the effects of approach velocity, duration of impingement, and fish 

length on the survival of six species of freshwater fish. These data were used to select 

variables for further evaluation with fully-operational fine-mesh traveling screens in a large 

flume. In Years 2-4, survival of larvae was assessed with screens from three different 

manufacturers using 0.5 to 2.0 mm screen meshes. Test variables included approach velocity 

(0.5 to 2.0 ft/s), duration of impingement (2 to 8 minutes), and fish length (5-28 mm) with eight 

species (bigmouth buffalo, bluegill, common carp, golden shiner, white sucker, channel catfish, 

hybrid striped bass, and rainbow smelt). There was considerable variability in survival 

depending upon species, especially with the earliest life stages. In general, smaller fish (<12 

mm) had poor survival while larger fish (>12 mm) had good survival. This increase in survival 

appears to coincide with development of scales and increased musculature. In general, there 

was a trend toward decreasing survival as duration of impingement or velocity was increased, 

but these relationships were not always significant. Duration of impingement was rarely a 

significant predictor of survival. In a fifth year of testing, a screen that removes organisms 

directly from the screen panel with a fish-friendly pump was evaluated. The variables tested 

included velocity (0.5 to 4.0 ft/s) and fish length (11-52 mm). Fish species tested included: 

bigmouth buffalo, bluegill, common carp, and white sucker. Survival with this screen exceeded 

65% and for two species survival was greater than 89% for all conditions tested. A similar 

pattern of increasing survival as fish grew larger was observed with this screen as with the 

previously tested screens. 

Biological Testing of Geiger MultiDiscTM Rotary Screens at Salem Generating Station 

Monday, September 5, 2011: 4:00 PM

Ken Strait, PSEG Power Sustainability, Public Service Enterprise Group, PSEG Power, LLC, 

Hancocks Bridge, NJ 

PSEG Nuclear, LLC installed a Geiger MultiDiscTM rotary screen with a fish collection and return 

system in the Salem Generating Station intake structure in 2006 and conducted biological 

testing of the pilot installation through November 2010. The modifications were intended to 

improve the capabilities of the cooling system to handle the high detrital load present in the 

Delaware Estuary during certain periods of the year. Latent impingement mortality (“LIM”) and 

entrainment length-frequency data for the rotary screen were collected for comparison to the 

existing long-term data on impingement/entrainment mortality of the other eleven Ristrophmodified traveling screens (6.35 x 12.7-mm woven wire mesh). Biological testing was conducted 
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with both 8.0-mm and 9.5-mm drilled plastic plate panels on the MultiDiscTM rotary screen. 

Results for the 8.0-mm mesh indicated higher LIM values than for the Ristroph screens. In order 

to estimate expected entrainment losses associated with the rotary screen, transfer factors were 

computed for each species/length class using the ratio of concentrations behind the rotary 

screen to concentrations behind a Ristroph screen. By applying these transfer factors to 

entrainment concentrations measured behind the Ristroph screens, and applying the measured 

rotary screen LIM values to impinged organisms, PSEG was able to estimate the combined 

impingement and entrainment losses for an overall comparison of a Ristroph screen to the 

rotary screen. The estimated impingement/entrainment losses were converted to biomass using 

a Production Foregone Model to determine that the average combined biomass loss (with 

entrainment survival) through the 8.0-mm mesh rotary screen would be slightly less than 

through a Ristroph-modified screen. The LIM and entrainment length-frequency data from 

biological testing of the 9.5-mm mesh are currently being analyzed and these results, including 

an estimate of combined impingement and entrainment losses using a Production Foregone 

Model, will be presented for an overall comparison of biological effects. 

Intake Technologies used at the Brunswick Steam Electric Plant to Achieve a Reduction 

in Impingement Mortality to a Level Similar to that of Closed Cycle 

Monday, September 5, 2011: 4:15 PM

Tom Thompson, Progress Energy Carolinas, Inc., Raleigh, NC 

The Brunswick Steam Electric Plant (BSEP) is located near the mouth of the Cape Fear River 

Estuary in North Carolina. The BSEP consist of two nuclear units. Once-through cooling water 

is withdrawn from the estuary and discharged to the Atlantic Ocean. To reduce impingement 

mortality, a fish diversion structure was built across the mouth of the intake canal in 1982 and a 

fish return system including traveling screens, spray wash, and return flume was completed in 

1983. Although reduced in scope and frequency in recent years, impingement monitoring has 

been conducted since the units came on line in 1977. Survival studies of impinged organisms 

were conducted from 1984 to 1987. Long-term data can be compared to baseline annual 

impingement to assess the effectiveness of the diversion structure in reducing impingement. 

Survival results provide additional insight regarding the overall effectiveness of the diversion 

structure and return system together in reducing annual impingement mortality. Reductions in 

the annual number of the historically dominant species impinged compared to baseline due to 

the fish diversion structure ranged from 55 % to 99 % depending on species. When survival 

study results are included the reduction in annual impingement mortality due to both the fish 

diversion structure and return system ranges from 77 % to 99% depending on species. Annual 

variability in the effectiveness of these mitigation technologies was evident. However, mean 

annual reductions in impingement mortality ranged from 94 % to 99% for the historically 

dominant species. Installation of the fish diversion structured resulted in a shift in species 

composition from primarily larger fin-fish to penaeid shrimp and blue crab (taxa exhibiting > 90% 

survival in the fish return system). Use of these mitigation technologies can be used to achieve 

reductions in impingement mortality approaching that of closed cycle cooling for many species. 
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Larval Avoidance Enhances the Entrainment Reduction Performance of Cylindrical 

Wedgewire Screens 

Monday, September 5, 2011: 4:30 PM

Mark Mattson, Normandeau Associates Inc., Portsmouth, NH 

A laboratory study was conducted in 2010 to estimate parameters of an avoidance/exclusion 

model that addresses three distinct mechanisms by which cylindrical wedgewire (CWW) 

screens can reduce entrainment: hydraulic bypass, avoidance, and mechanical exclusion. 

CWW screens with slot widths of 2, 3, 6, and 9 mm were tested at flume velocities of 0.08, 

0.15, and 0.30 m/sec, with through-slot velocities of 0.08 and 0.15 m/sec. Tests were 

conducted by releasing neutrally buoyant beads, fish eggs of approximately 1 and 3 mm 

diameter, and fish larvae with robust (Atlantic tomcod, striped bass) and slender (white sucker) 

body forms at a location of known high probability of entrainment immediately upstream of the 

test screen. The length, body depth, and number of the test subjects carried past, entrained 

through, or excluded and retained on the CWW screen was recorded. Tests were done with 

both live and dead larvae, and under ambient daylight and nighttime conditions. Avoidance 

curves, expressing the relationship of probability of avoidance with fish length, and exclusion 

curves, expressing the relationship of probability of exclusion with greatest body depth, were fit 

to data for each set of test conditions using nonlinear regression. Avoidance was typically 

higher during the day, for the smaller slot sizes, for the lower through-slot velocity, and at higher 

ratios of flume/slot velocity. Exclusion of live larvae was reduced as slot velocity increased on 2 

mm CWW screens. Exclusion of white sucker eggs (3.3 mm diameter) by 2 mm CWW screens 

was nearly 100% at either through-slot velocity, but was somewhat lower (70%-95%) with 3 mm 

CWW screens. The probability of being swept off, if excluded, was higher for the white sucker 

eggs than for fish larvae, was higher for the low slot velocity (0.08 m/sec), and increased with 

increasing flume velocity. The 2010 laboratory study confirmed that avoidance of the CWW 

screens tested occurs for fish larvae, and that expected avoidance capability has an 

exponentially increasing relationship with length. The performance of CWW screens for 

reducing entrainment was a combination of the potential for bypass, avoidance and exclusion.

Selection of an optimal slot width CWW screen should account for these three performance 

components. 

Laboratory Evaluations of Fish Return Systems – What Designs Work 

Monday, September 5, 2011: 4:45 PM

Ray Tuttle, Alden Research Laboratory, Inc., Holden, MA 

Daniel Giza, Alden Research Laboratory, Inc., Holden, MA 

Brian McMahon, Alden Research Laboratory, Inc., Holden, MA 

Guidelines for fish conveyances and other fish handling systems have been developed by 

federal, state and professional organizations. These guidelines were developed through an 

understanding of the hydraulic conditions likely to produce injury and mortality to adult fish. 

However, little information exists on the effects of fish return systems on larval or early juvenile 

survival. The Electric Power Research Institute (EPRI) funded laboratory studies on factors 

affecting larval fish survival through a fish return system. Initially, the effects velocity and height 

of discharge were evaluated. Two 21.6 m (71 ft) pipes were pitched such that a velocity of 0.6 

m/sec (2 ft/sec) and 1.8 m/sec (6 ft/sec) could be achieved. Discharge heights evaluated were 
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sub-surface, 0.6 m (2ft), and 1.2 m (4 ft). The system was modified to a length of 131 m (430 ft) 

and several 90 degree drops, a sweeping curve, and a serpentine section were added. The test 

velocity was 1.8 m/sec (6 ft/sec) with a sub-surface discharge. Testing also included three 

replicates (50 fish) with each combination of species (6), lifestage, and release locations plus 

controls. A summary of the results is as follows: 

 Survival (48-hr) for all species was poor (20-60%) during the transition from yolk-sac to 

post-yolk-sac larvae. Survival ranged from 70-100% after the fish were approximately 

12 mm in length.

 Velocity had no effect on survival within length groups. 

 Except for common carp, discharge height [subsurface to ≤1.2 m (4 ft)] had no effect on 

survival within length groups among species. 

 Increasing the length and adding drops and bends did not affect survival within length 

groups. 

Based on these results, transit of fish ~12 mm through a well-maintained fish return system 

should not result in increased mortality. The influence of debris and roughness were not 

assessed. 

Selecting BTA in the Real World 

Monday, September 5, 2011: 5:00 PM

James McLaren, ASA Analysis & Communication, Inc, Washingtonville, NY 

Bill Dey, ASA Analysis & Communication, Inc, Washingtonville, NY 

Although the National Rulemaking for Section 316(b) has yet to be finalized, several state 

regulatory agencies have been moving ahead to establish BTA for existing cooling water intakes 

within their jurisdiction. One of these regulatory agencies is the New York State Department of 

Environmental Conservation (NYSDEC), and one of the early facilities to have completed the 

BTA selection process is located on Long Island. Entrainment and impingement at this facility is 

dominated by common inshore marine species of Long Island Sound, including tautog, cunner, 

and Atlantic menhaden. The selection of BTA began with a screening of all reasonable intake 

and operational alternatives to determine those feasible at this facility that also will reduce 

current levels of entrainment and impingement. One key factor in selecting BTA at this facility is 

the load-following (cycling) operation during the warmer months when entrainment is expected 

to be highest and low anticipated operation during the colder months when impingement is 

expected to be highest. This operating mode opens the door for considerable reductions in 

cooling water flow when generating load is low. A detailed review of the potential for both 

entrainment and impingement survival also was conducted to include in the evaluation process.

Analysis of the potential benefits of each of the feasible alternatives revealed that variablespeed drives (VSDs) on the existing cooling water pumps and continuous screen operation, 

coupled with entrainment and impingement survival, would reduce entrainment to more than 90 

percent of the level of cooling towers and impingement to a level equivalent to cooling towers.

Further, when taking into account installation times, VSDs actually would provide greater 

reduction in entrainment than cooling towers for more than 40 years into the future. 
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Protecting Fish At Power Plant Cooling Water Intakes:

New Developments and Science on Clean Water Act §316(b),

Part 2

Sponsored By: AFS Bioengineering Section 

Introduction

The U.S. Environmental Protection Agency (EPA) on April 20, 2011 released a proposed rule 

for public comment implementing technology-based standards for fish protection at existing 

power plants and other facilities that use cooling water in accordance with the requirements of 

§316(b) of the Clean Water Act. This regulatory action affects almost 1,300 facilities (power 

plants, pulp and paper mills, iron mills, chemical plants) around the U.S. that use cooling water. 

These industries, federal and state regulatory and resource agencies, non-governmental 

organizations and the public will all need the latest information on technologies and related 

information for protecting fish and shellfish at cooling water intakes – this includes traveling and 

fixed screens, barrier nets, behavioral systems, closed cycle cooling systems, and other 

methods for reducing, excluding or collecting and returning fish and shellfish to source water 

bodies. Information will also be needed on methods for characterizing impingement and 

entrainment and for determining the performance of technologies. Methods for economic 

analysis to determine the cost-benefit for compliance activities may also be needed. This 

symposium will gather practitioners with expertise in fish protection/bioengineering at cooling 

water intakes to present and discuss the latest scientific developments in this field. 

Hydrolox Fish Friendly Polymer Screens - Designed for Compliance with 316(b) 

Tuesday, September 6, 2011: 8:00 AM

Tim Woodrow, Intralox Inc., New Orleans, LA 

This presentation willdocument the results of numerous independent laboratory and in-field 

tests, and highlight the value that Hydrolox screens have consistently provided for many 

companies and organizations, all while providing a platform for 316(b) compliance. Hydrolox 

determinedly researched and tested existing steel mesh screens in order to understand how 

cooling water intakes might be made more effective. It then challenged its engineers and 

designers to come up with a design that could both protect aquatic life and radically reduce 

operational and maintenance costs. The result is a strong, modular screen with superior 

resistance to abrasion, bio-fouling and impact that also saves a high percentage of aquatic life. 

To validate the ability of the polymer screening technology to protect aquatic life, several studies 

on impingement and or entrainment have been conducted. The presentation will cover 

impingement results from Alden Laboratory and from an independent environmental testing 

company at a NY power station, the results of an entrainment study by Alden Laboratory under 

the sponsorship of EPRI, and the results from a 2 year study on impingement and entrainment 

on the River Thames in England. These studies demonstrate that Hydrolox screens provide a 

high survivability rate across a diverse range of species in a variety of challenging 

environments. 
12

Fish Deterrent and Protection Using Non-Physical Barriers & Special Intake Screens 

Tuesday, September 6, 2011: 8:07 AM

Kaveh Someah, OVIVO Water Inc., Salt Lake City, UT 

With today’s new legislation of 316 (b) regarding the reduction in mortality of juvenile fish, there 

are numerous ways to increase survivability with proven technology. This paper will discuss two 

(2) of those methods; a) Fish Guidance and b) Fish Recovery. The first method of “Fish 

Guidance” utilizes years of research followed by a number of successful and proven 

installations of “guiding” or deterring fish via the proper combination of stimuli. Fish will respond 

to certain queues yet over time, seemed too have acclimated and ignored what was previously 

a nuisance to them. This was primarily due to only one type of stimuli or a set frequency being 

utilized. The proper combination sound, air and light have been successfully employed to deter 

populations of fish from a particular destination. The use of a Sound Projection Array (SPA), 

which utilizes an altering frequency of sound to repel fish and warn them of impending danger 

causes them to steer away from paths such as circulating water intakes, thus reducing the 

quantity of fish drawn into the cooling water system. Other methods include a BioAcoustic Fish 

Fence (BAFF), which utilizes an SPA combined with a bubble curtain, which captures the sound 

thus increases the dispersion to the surface and can guide migratory fish around an intake 

structure. Other installation may also use strobe lights to provide a visual queue or warning of 

the approaching deterrent system. Certain installations require the use of all three to properly 

guide various species past structures. Levels as high 73-95% deflection have been attained in 

many installations. The second method of “fish recovery” uses specifically designed cooling 

water intake traveling screens to recover fish drawn into the intake system and release them 

virtually unharmed away from the intake. Traveling screens are used to prevent debris from 

clogging a plants condenser. Fish normally impinged against the mesh and would otherwise find 

themselves in the debris washed from the screens are now captured in a hydraulically stabilized 

“fish bucket” which provides both shelter and a quick, safe removal from the screens. The 

stabilized shape literally draws the fish into the bucket vs. impingement via exhaustion against 

the mesh. As the screen rotates, low pressure fish sprays remove fish from the screens, placing 

them into a dedicated fish return trough. Survival rates vary by species but for many installations 

have been as high as 85-90%. 

Fine Slot and Mesh Size Screen Alternatives for Protecting Fish Eggs and Larvae at 

Cooling Water Intakes 

Tuesday, September 6, 2011: 8:15 AM

John A.D. Burnett, Power and Energy, HDR Engineering Inc., Park City, UT

Thomas Englert, Ferm, HDR Engineering Inc., Pearl River, NY

Stephen McKelvie, Ferm, HDR Engineering Inc., Boston, MA

State and Federal regulators are in the process of implementing major changes to the 

regulations that apply to existing cooling water intake systems with the goal of further reducing 

injury to fish at these facilities. These regulatory changes have been met with increased 

interested in fish protection technologies, other than very costly cooling towers, that can achieve 

the required reductions. Facility owners face many challenges as they work to determine 

exactly which technologies and/or operational measures to implement at their facilities. An 
13

important area of compliance alternative selection is estimation of the site-specific fish 

protection performance that can be achieved by each alternative technology being considered. 

This paper compares and contrasts two potential retrofit technologies – narrow slot wedgewire 

and fine mesh travelling screens – that have the potential to meet the anticipated performance 

standards for entrainment and impingement reductions. Because of the small size of eggs and 

larvae, the slot size/mesh size of the screens must be on the order of 2.0 mm or smaller in order 

to meet the targeted reductions in entrainment. Innovative approaches to estimating preinstallation entrainment and impingement reduction performance were developed to make 

predictions about each technology’s potential to meet the standards. Similarly, screening 

technology design, configuration, operation and maintenance solutions were developed along 

with cost estimates as a part of the technology selection process. Trade-offs in terms of fish 

protection, operational reliability, and costs are examined. 

Role of Entrainment Survival in the BTA Selection Process 

Tuesday, September 6, 2011: 8:30 AM

John Young, ASA Analysis & Communication, Inc, Washingtonville, NY

That some fish eggs, larvae, and early juveniles can survive passage through the cooling water 

systems of steam electric facilities has been known for more than 30 years. The studies leading 

to this reveal that survival varies with species-, size, and temperature exposure, with survival 

estimates ranging from near zero for newly hatched delicate species to almost 100 percent for 

hardier species and life stages. In this paper, we review key developments in the evolution of 

sampling gear, study designs, and analytical techniques that led to reliable estimates of 

entrainment survival. Despite the past successes, some skepticism remains about the role of 

entrainment survival in the BTA selection process. We demonstrate that failure to consider 

entrainment survival where it exists may 1) overestimate of the potential for adverse 

environmental impact and, hence, the benefits (both biological and economic) of alternative 

intake technologies designed to reduce entrainment losses, and 2) lead to the selection of 

intake alternatives that actually increase the impacts to individual fish populations. This 

phenomenon will be illustrated for fine-mesh traveling screens, a technology gaining some 

interest as potential BTA. Consideration of entrainment survival in the BTA selection process is 

receiving increasing acceptance within at least one regulatory agency (New York State 

Department of Environment Conservation) and necessitated site-specific confirmatory studies 

which were conducted this summer. Preliminary results of this effort will be described. 

Evaluation of Cooling Water Intake Technology Alternatives with Consideration of 

Engineering, Costs, and Biological Efficacy on a Narrow, Sediment-Laden, and BargeHeavy River 

Tuesday, September 6, 2011: 8:45 AM

Lorin K. Hatch, HDR Inc., Minneapolis, MN

John Larson, HDR Inc., Minneapolis, MN

Compliance with the Clean Water Act Section 316(b) Phase II Rule and also meeting the fullypermitted cooling intake capacity at a riverside power plant in Minnesota has presented unique 

challenges. The existing traveling screens (3/8" slot size) at the screenhouse are several 

decades old and are not adequate for meeting the Phase II Rule requirements, while the size of 
14

the eight existing bays within the screenhouse limit the number and size of wedgewire screens 

that could be placed within each bay. There are also space limitations in the area outside the 

screenhouse, which is located on a 300 to 500 feet wide river bend that experiences barge 

traffic during the open water season. Barges have been noted to come within several feet of the 

screenhouse sheet piling, and tugboat motors generate a large amount of turbulence (and 

hence sediment) when driving the barge around the river bend near the screenhouse when 

heading upstream. Given these conditions, HDR conducted a study to determine the feasibility 

of locating wedgewire screen units at the existing screenhouse. Options considered included 1) 

placement of all screen units inside of the screen house, 2) placement of all screen units outside 

of the screen house in the area between the log boom and the screen house wall, and 3) a 

hybrid in which screen units were placed both inside and outside of the screen house. 

Considerations also included 2.0 vs. 0.5 mm slot sizes, debris removal, and fish recovery. 

Abundance and Composition of Fish and Shellfish Impinged and Entrained at Power 

Plant Intakes Based on a Survey of Over 220 Power Plants 

Tuesday, September 6, 2011: 9:00 AM

Greg Seegert, EA Engineering, Deerfield, IL

In response to EPA’s 2004 Phase II 316(b) Rule, most of the nation’s once-through power 

plants conducted impingement and, where required, entrainment studies, hereafter referred to 

as IM&E. EPRI determined that the data collected during these studies represented a unique 

opportunity to characterize IM&E at the nation’s power plants. A web-based survey was used to 

collect information including plant location and operating characteristics, sampling methodology 

and, most importantly, IM&E results. Responses were received from 240 plants representing 

approximately 56% of the in-scope facilities. Results were stratified by both geographic area 

and waterbody type (e.g., estuaries, oceans, large/small rivers, the Great Lakes, reservoirs).

Initial compilation of the data indicates that IM&E vary widely. Estimated annual impingement 

losses ranged from less than 1000 fish to approximately 70 million fish. Estimated entrainment 

losses ranged from zero eggs and larvae per year to approximately 36 billion organisms per 

year. It was found that clupeids (threadfin shad in the southeast and the southwest and gizzard 

shad elsewhere) dominated impingement at most freshwater plants. Impingement results 

differed greatly among East Coast plants, those on the Gulf Coast, and those in California. 

White perch, blue crab, Atlantic croaker, and bay anchovy were the most commonly impinged 

organisms at coastal areas, except the West Coast. Entrainment results also differed widely 

depending on region and waterbody type. Few threatened or endangered species were 

collected in impingement or entrainment samples. It was found that only a small percentage of 

these plants have any fish protection devices in place. There were little or only 

weak relationships between IM&E rates and plant size, which is a reasonable surrogate for 

pumping rate. We concluded that both IM&E rates and composition are determined by 

unknown site-specific or, at most, region-specific factors. 

Coastal Fish Populations Fluctuate Independent of Once-Through-Cooling Water Use in 

Southern California: The SONGS Case 

Tuesday, September 6, 2011: 9:15 AM

Eric Miller, MBC Applied Environmental Sciences, Costa Mesa, CA

D. Shane Beck, MBC Applied Environmental Sciences, Costa Mesa, CA
15

Kim Anthony, Southern California Edison, Rosemead, CA

Power plant once-through-cooling has been a contentious issue since the 1972 passage of the 

Federal Clean Water Act. The greatest debate centers around the impacts of impingement and 

entrainment of marine life, especially fishes, on the natural environment and source populations. 

Considerable work has been done to document the impingement and entrainment at a specific 

or suite of power plants using statistical modeling and often temporally brief studies. Few 

monitoring programs, however, have been maintained over extensive periods to document longterm (decadal or greater) trends in both impingement and entrainment, but also natural variation 

in the source populations and the environment. Of studies that meet these criteria, few 

encompass substantial changes in cooling water flow volumes. Southern California is unique in 

the presence of an extensive time series of juvenile/adult fish entrapment monitoring at local 

power plants and an independently executed ichthyoplankton sampling program. Both of these 

time series overlap the commercial startup of the San Onofre Nuclear Generating Station’s 

(SONGS) Units 2 (1983) and 3 (1984), which resulted in an additional 2400 million gallons of 

daily cooling water circulation without an immediate reduction in the remaining facilities with 

offshore intakes in southern California. By utilizing ichthyoplankton data from the extensive 

California Cooperative Oceanic Fisheries Investigations (CalCOFI) nearshore station sampling 

(1950-2009) and brief (1978-1986) sampling directly offshore of SONGS, we derived the longterm patterns in the 16 most common species occurring in both time series. Comparisons of 

these trends with long-term cooling water flow volumes resulted in clear evidence of no 

relationship between ichthyoplankton densities and cooling water flow volumes. Extrapolating 

the larval densities recorded at the CalCOFI nearshore stations in 2006 indicates ~ 9 trillion 

larvae were along the southern California coast. We chose 2006 as this was the year that the 

majority of studies were completed from which the State Water Resources Control Board 

compiled an overall statewide estimate of 19 billion larvae entrained by once-through-cooling. 

Based on these estimates, ~0.08% of the source larvae was entrained by southern California’s 

offshore once-through-cooling intakes. 

Relationships Between Entrainment and Larval Drift At a Large-River Power Plant 

Based on 2600 Samples Collected During a 2-Year Period 

Tuesday, September 6, 2011: 9:30 AM

John Thiel, Dairyland Power Cooperative, La Crosse, WI 

Greg Seegert, EA Engineering, Deerfield, IL 

From April through August 2002 and again during this same period in 2003, larval samples were 

collected from the Mississippi River and the intake to the Madgett Power Plant to assess 

possible impacts associated with possibly adding another unit to the plant. Samples from the 

river were collected using paired 0.5 m diameter, 500 micron plankton nets from transects 

upstream and downstream of the intake. Samples were stratified by depth and position across 

the river and collected on a diel basis. In addition to the collections along the transects, a 

location within the intake’s zone of influence was also sampled. Seventeen sampling periods 

were established each year and concurrent with each one, a 24 hr entrainment sample was also 

collected. Ultimately, about 2600 samples were collected. Larval densities peaked both years 

the second week of June. The drift was dominated by freshwater drum, gizzard shad, and 

emerald shiner “types”. Drum and shad were also common in the entrainment samples.

However, the study showed that a number of other species that were common in adult fish 

collections we made during this same period were not well represented in the entrainment 
16

samples, probably because of life history characteristics of these species. For example, walleye 

and smallmouth bass, which are the two most popular sport fish in this area, were common as 

adults in the river but were rare to uncommon in the drift and the entrainment samples. In 2002, 

we estimated that about 19.9 billion eggs and larvae drifted past the plant’s intake but < 1% of 

these were entrained, a biologically inconsequential number. 

Using CODAR Data on Surface Currents to Estimate the Source Water Area for Fish 

Larvae Potentially Subject to Entrainment by the Diablo Canyon Power Plant Along the 

Coast of Central California 

Tuesday, September 6, 2011: 10:15 AM

John R. Steinbeck, Tenera Environmental, San Luis Obispo, CA 

John Hedgepeth, Tenera Environmental, San Luis Obispo, CA 

Brian Zelenk , Center for Coastal Marine Sciences, California Polytechnic University, San Luis 

Obispo, San Luis Obispo, CA

The standard approach for evaluating the effects of power plant and desalination plant intake 

systems in California is a modified Empirical Transport Model (ETM). The fundamental inputs to 

this model are estimates of mortality based on the ratio of the estimated number of organisms 

entrained to the estimated number in the portion of the source water being sampled. The 

estimates of mortality are then extrapolated to the larger source water along the coast using 

data on coastal currents and the period of time that the organisms are in the water column and 

exposed to entrainment. Extrapolating the actual source areas for the larvae has recently been 

facilitated by the availability of data on surface currents from high frequency radar installations 

(CODAR) sites along the California coast. This presentation describes the use of this approach 

in a recent study on the effects of entrainment at the Diablo Canyon Power Plant in central 

California. The study also incorporated two acoustic Doppler profilers (ADCP) that were used to 

adjust the speed and direction of the surface currents measured by the CODAR to values being 

measured in the water column by the ADCPs. The resulting extrapolated source water areas 

were consistent with general knowledge on the ocean currents in the area, including the 

presence of eddies north and south of the headland where the plant is located. The recent 

policy on once-through cooling adopted by the State of California requires that plants mitigate 

for impacts for the period between the date they are required to comply with the Policy and the 

actual date of compliance. The preferred approach for scaling mitigation in the Policy is based 

on the estimates of mortality and source water areas from ETM, which are greatly improved 

through the use of CODAR. 

Selectivity of Impingement at Power Plants along the Ohio River 

Tuesday, September 6, 2011: 10:30 AM

Ron King, EA Engineering, Atlanta, GA 

Greg Seegert, EA Engineering, Atlanta, GA 

Joe Vondruska, EA Engineering, Atlanta, GA

Impingement abundance monitoring and standardized fish sampling in 2005 and 2006 near 15 

Ohio River power plants as part of the Ohio River Ecological Research Program suggested 

impingement of fishes at intake structures was selective and did not necessarily provide a 

representative characterization of assemblages in the source water. We compared species 
17

composition and relative abundance from the two data sets to evaluate potential explanations 

for the presence, absence, or disproportionate occurrence of fishes in the impingement samples 

relative to their abundance in the river as measured by seasonal electrofishing and seining 

collections. The impingement study demonstrated similarities in species composition among 

power plants over nearly 1,400 river kilometers of the Ohio River, whereas the river surveys 

showed that the abundance of some species varied considerably over the course of the river. 

As expected, clupeids dominated the impingement collections, but at much higher levels than 

suggested by the river surveys, while other forage species, especially emerald shiner and 

channel shiner, were under represented in the impingement collections. During the two-year 

study, 32 species collected during the river surveys were not impinged whereas 13 species 

were impinged that were not collected during the river surveys. The impingement study showed 

that many species in the Ohio River are not particularly susceptible to impingement because 

their behavior, habitat preferences, or low population levels reduce the likelihood of them being 

impinged. This was especially evident for cyprinid, darters, and redhorse. The opposite was true 

of the abundant, pelagic schooling clupeids that were occasionally impinged at very high rates, 

often during periods with declining water temperatures. Freshwater drum and channel catfish 

were also impinged at much higher rates than would be predicted based on their abundance in 

the river collections. 

Entrainment Abundance and Composition Differ from Source Water Ichthyoplankton at 

Plant Vogtle, Savannah River, GA 

Tuesday, September 6, 2011: 10:45 AM

Tony Dodd, Georgia Power Company, Atlanta, GA

GPC biologists performed an entrainment assessment at Plant Vogtle’s make-up water intake 

structure in 2008. Intake entrainment was compared to ichthyoplankton samples from Savannah 

River source water. Semi-monthly sampling was conducted at a mid-depth intake location and 

an upstream source water transect location during March – July. Source water was sampled 

with a double 0.5 m plankton net rig equipped with 500-micron mesh nets at 1-m depth intervals 

on 6-hr nodes over 24 hours. Entrainment sampling consisted of a submersible pump system 

(4.6 l/s capacity) sampling at a mid-depth intake canal location about 46 m from the intake 

screens. Intake waters were sampled through the same net rig used for source water mounted 

inside the mouths of tandem 208-l plastic drums located beside the intake canal. Substantial 

differences in abundance, species composition, and life stage composition were observed 

between source water and entrainment. Dominant species and life stages in source water 

differed from entrainment. Source water eggs and larvae were 36.4 times more numerous than 

entrainment. Source water samples yielded 23 species compared to only seven taxa in 

entrainment. Eggs were most abundant in source water compared to no eggs in entrainment. 

Intake pumping was consistent during the sampling. No significant relationships were found 

between entrainment rate and environmental variables or river discharge. GPC’s 1970s desktop 

studies concluded that minimal entrainment would result at Plant Vogtle. Disparity between 

source water and entrainment abundance and composition in this applied study is conjectured 

as likely due to a combination of physical and hydraulic characteristics of the intake site and 

structure. 
18

EPA's New 316(b) Rule: Do Biologists Have a Role? 

Tuesday, September 6, 2011: 11:00 AM

James N. Christman, Hunton & Williams, Washington, DC 

Kristy A. N. Bulleit, Hunton & Williams, Washington, DC 

In March 2011 EPA published its latest, and possibly last, proposed rule on minimizing 

impingement of fish and entrainment of eggs and larvae by cooling water intake structures such 

as those at power generating stations. Before this latest rule, EPA's preference, partly for ease 

of administration, was to measure "adverse environmental impact" by how many fish, eggs, and 

larvae are lost to the aquatic community. The new rule raises, once again, the question of how 

much EPA's requirements for cooling water withdrawals should take into account the knowledge 

fisheries biologists have accumulated about aquatic communities. The fundamental question is 

whether there are situations in which the sacrifice of fish (or eggs or larvae) does essentially no 

harm to the "environment" and whether EPA’s regulations should recognize them. Conceptually 

there are at least two ways to go beyond a simple fish-count approach and consider the loss of 

organisms in the context of “environment.” One is to estimate the “value” of fish, eggs, and 

larvae and then compare that estimate to the cost of preventing losses (that is, some form of 

cost-benefit analysis). Here EPA proposes to use a public opinion survey to measure how 

much value the public assigns to changes in fish populations; there is some role for biologists in 

designing the survey instrument, but the data gathered are the lay opinions of the public. The 

second approach is to consider the overall health of the aquatic community in the waterbody 

and whether it will be materially harmed by entrainment and impingement. This cannot be done 

without an informed use of fisheries science, bearing on the questions what constitutes a 

“healthy” aquatic community?; how do aquatic communities react to stresses such as 

entrainment and impingement?; and how much loss can a community sustain without serious 

harm in the long run? 

Adverse Impacts of Cooling Water Withdrawals on Populations and Ecosystems: 

Separating Fact From Conjecture 

Tuesday, September 6, 2011: 11:15 AM

Larry Barnthouse, LWB Environmental LLC, Hamilton, OH

Impacts of entrainment and impingement (I&E) at cooling water intake structures have been a 

topic of controversy for nearly 40 years. It has been argued that cooling water withdrawals at 

large thermal power plants have contributed to the depletion of valued marine and freshwater 

fish populations, and that these withdrawals may also disrupt aquatic food webs through indirect 

impacts on lower trophic levels. It has also been argued that the mortality caused by I&E is 

small compared to natural and fishing mortality, and that indirect impacts of cooling water 

withdrawals are small or non-existent. What is usually missing in this discussion is an 

evaluation of historical evidence concerning these impacts from the four decades of fish stock 

assessment, environmental monitoring, and scientific research that have occurred since I&E 

first became a significant regulatory issue. This presentation will address the issue of adverse 

impacts through a review of published scientific literature relating to the causes of adverse 

changes in marine and freshwater ecosystems. The reviewed literature will include (1) peerreviewed papers and agency stock assessment reports documenting the causes of declines in 
19

marine and freshwater fish populations, (2) “blue-ribbon” commission reports and relevant 

National Academy of Sciences Reports that discuss causes of fish population decline 

ecosystem degradation, and (3) scientific literature relevant to evaluation of the indirect impacts 

of I&E on the services provided by freshwater and marine ecosystems. 

Investigations into the Relationships between Fish Impingement and Fish Health 

Tuesday, September 6, 2011: 11:30 AM

Bill Garrett, Alabama Power Co., Birmingham, AL

Various 316(b) research projects, sponsored by Alabama Power Company (APC), were initiated 

in 2004 to investigate the relationship between fish impingement and fish health. These 

projects used fish health assessments, Acoustic Doppler Current Profiling (ADCP) and 

hydroacoustic technologies. Most of these studies were conducted at Plant Barry which is 

located on the lower Mobile River. While the scope of these projects varied, initial sampling 

indicated the species impinged with greatest frequency and mitigation value were threadfin 

shad, freshwater drum, blue catfish, and channel catfish. Therefore, these species were chosen 

for further fish health examination to test the hypothesis that impingement may select for 

unhealthy individuals from the natural environment. Fish health examinations included 

necropsies for prevalence of bacterial and parasitic infections. Impinged fish were compared to 

open-water fish obtained from within 2.4 km of the vicinity of the cooling water intake structure 

(CWIS) and to fish collected from inside the CWIS (screen pit). Results of this study support the 

general hypothesis that impingement may select for unhealthy fish. However, the high biomass 

and high density of relatively healthy fish found in the screen pit supports the hypothesis that 

impingement may select for “naturally” unhealthy individuals from the hydraulic zone of 

influence (HZI). Another investigation into the relationship between the volume of the HZI, the 

through-screen velocity and the amount of impingement at various power plants suggests a 

potential confounding effect between the HZI and through-screen velocities. Furthermore, 

studies using hydroacoustics to monitor fish movement inside the CWIS also suggest that free 

movement exists for many fish in and out of the CWIS on a diurnal basis. Results of these 

studies indicate that the cause and effect relationships concerning fish impingement requires 

further study and may be justified due to the expense and questionable results of various 

mitigation options. 

Nearshore Biological Baseline and Fisheries Assessment at Marine Corps Base Camp 

Pendleton; A Regional Data Source to Supplement Site-Specific Impingement and 

Entrainment Assessments 

Tuesday, September 6, 2011: 11:45 AM

Brian Dresser, Tetra Tech, Inc., Manchester, NH 

One of the more challenging components of any fisheries impact assessment is collecting the 

appropriate level of data to accurately characterize existing baseline conditions. Site-specific 

data are usually preferred to capture the unique conditions present at most facilities. However, 

other local or regional data may act as a useful supplement to help assess the “calculation 

baseline” characterization of impingement and entrainment impacts. Such data are particularly 

useful in demonstrating how the placement or design of an intake structure (location, depth, 

velocity cap, etc.) may reduce impacts from the baseline condition. Regional data also provide 
20

regulatory agencies an opportunity to compare site-specific conditions to the larger marine 

ecosystem. The cooling water intake structure of the San Onofre Nuclear Generating Station 

(SONGS) is located offshore of Marine Corps Base Camp Pendleton (MCBCP), in southern 

California. Site-specific impingement and entrainment data have been collected at SONGS 

almost continuously since 1979. Recently, in an unrelated effort, MCBP conducted a habitat 

characterization and biological survey of the nearshore area along MCBCP’s 17 miles of 

coastline out to a distance of approximately 3 miles. The assessment included finfish, 

invertebrate, and kelp bed habitat surveys as well as bathymetric and sediment surveys; all 

within the vicinity of SONGS intake/discharge location. The nearshore area along the coast of 

MCBCP is a critical amphibious beach training and operational area; yet, prior to this survey, 

little baseline data exist for the marine resources associated with MCBCP. This presentation 

will provide an overview of the findings from this survey, framed within the larger context of a 

regional perspective of the Southern California Bight. A discussion of how the facilities that 

withdraw water from offshore intakes in the region might use such data in characterizing 

baseline conditions. It is reasonable to expect, given MCBCP and SONGS proximity to one 

another, that these regional data are complementary and could be used to supplement sitespecific data. In this manner, the MCBCP survey provides a regional perspective for SONGS, a 

proposed desalination plant, and other Southern California generating stations with offshore 

intakes regulated by the California Regional Water Quality Control Boards. 

Climate Change: 316 to the Future 

Tuesday, September 6, 2011: 11:52 AM

John Balletto, ARCADIS U.S., Inc., Cranbury, NJ 

Focus on large-scale and long-term effects of climate change can sometimes obscure more 

immediate, operational concerns that are important and warrant anticipation and planning. The 

electric power industry, already dealing with demand-side impacts of global warming, will soon 

experience increasingly intense supply-side exigencies. In this presentation we identify and 

discuss a suite of environmental parameters potentially impacted by climate change. Examples 

include potential withdrawal excursions necessary to meet thermal limits in regionally warming 

receiving waters, changes in species involved with cooling systems, qualitative and quantitative 

changes in biofouling communities, and efficacy of antifouling technologies, hardware limits 

such as corrosion potentially affecting fouling, directional changes in waterway biota not 

anticipated in design or permit specifications, infrastructure inundation and storm effects on 

screens and sluices, and others. We present a bracketing series of systems planning scenarios, 

summarizing data useful for anticipating nature and intensity of effects, scope for responses, 

and threshold constraints. 

Models for Assessing the Cumulative Impacts on Larval Fishes Due to Entrainment 

From Multiple Power Plant Intakes in the Southern California Bight 

Tuesday, September 6, 2011: 1:15 PM

John Hedgepeth, Tenera Environmental, San Luis Obispo, CA

John R. Steinbeck, Tenera Environmental Inc., San Luis Obispo, CA

James M. Strampe, Tenera Environmental Inc., San Luis Obispo, CA

Brian Zelenke, Center for Coastal Marine Sciences, California Polytechnic University, San Luis 

Obispo, San Luis Obispo, CA
21

The cumulative impacts of multiple power plant intakes have been a concern of resource 

agencies and other stakeholder groups in California and in other locations in the United States. 

Cumulative impacts are also required to be addressed under permitting done in compliance with 

the California Environmental Quality Act (CEQA). As a result, the California Energy Commission 

required that cumulative impacts were addressed in the documentation submitted as part of the 

permitting process for the repowering of the Huntington Beach Generating Station in southern 

California. A 2004 workshop on the issue resulted in the development of a first-order model that 

could be expanded as additional data became available. This model evaluated the potential 

effects of entrainment by the twelve power plants in the Southern California Bight, the area from 

point Conception to just south of the U.S.-Mexico border, that withdraw a total average of 

24.0x109 l of seawater daily. Since data on larval fish entrainment were not available from all 

twelve plants at that time, a volumetric approach was used to estimate entrainment mortality. 

This approach assumed that, on average, the larvae were uniformly distributed in the nearshore 

areas where the intakes are located. This was shown to be a reasonable assumption for 

locations such as Huntington Beach, where the offshore intake is located along fairly 

homogeneous stretch of sandy beach. This simple model showed that power plant intakes 

accounted for additional mortality of 0.11 to 0.84 percent which varied depending on the period 

of time that the larvae were exposed to entrainment. The model was expanded to account for 

different rates of water movement once data on nearshore currents were available from a 

number of locations. These simple models of cumulative impacts can be expanded to include 

more detailed current patterns using high resolution CODAR surface current data that are now 

available for nearshore areas in California. 

Economic and Biologic Benefits of Cooling Tower Retrofits 

Tuesday, September 6, 2011: 1:30 PM

Bill Dey, ASA Analysis & Communication, Inc, Washingtonville, NY 

One possible outcome of the ongoing 316(b) regulatory process could be a requirement to 

install cooling towers at all existing Phase II facilities nationwide. Such a regulatory requirement 

would substantially reduce current levels of entrainment and impingement but would do so as at 

considerable costs and potentially produce other environmental impacts. As part of a large 

project to evaluate the environmental and economic trade-offs resulting from such a regulatory 

outcome, we estimated the benefits of cooling tower retrofits resulting from expected reductions 

in entrainment and impingement. These benefits were defined in both biologic (fishery yield and 

biomass production) and economic terms. This estimation process began with determining 

benefits of cooling tower installation at 50 representative facilities nationwide. These benefits 

were estimated based on recent entrainment and impingement monitoring data using standard 

population modeling and resource economics techniques. In addition to the most probable 

estimates, both sensitivity and Monte Carlo techniques were used to evaluate the uncertainty in 

these results. The results from this estimation process were combined with estimates of biologic 

and economic benefits developed for other facilities to project the biologic and economic 

benefits on a national basis. The results of this effort will provide a sound basis for comparing 

the costs to the benefits of national cooling tower retrofits on both an environmental and an 

economic basis. This paper will provide an overview of the process used as well as examples 

of results and a discussion on the factors contributing to the wide range in benefits projected to 

occur across the individual facilities. 
22

Evaluating the Role of Nonuse Values in Estimating the Benefits of a National ClosedCycle-Cooling Retrofit Requirement 

Tuesday, September 6, 2011: 1:45 PM

Jason Kinnell, Veritas Economics, Cary, NC 

Matthew F. Bingham, Veritas Economics, Cary, NC

A national closed-cycle-cooling-retrofit (retrofit) requirement will affect fish that are both caught 

and uncaught. Uncaught fish do not have a traditional use value and are therefore categorized 

as having potential nonuse values. Nonuse values are the values that people may hold for a 

resource independent of their use (i.e., some people may benefit simply from knowing the 

resource exists—either because they want it to be available for people to use in the future or 

because they believe the resource has some inherent right to exist).

Currently, the only methods available for estimating nonuse values are survey-based 

techniques that ask respondents to value, choose, rate, or rank natural resource services in a 

hypothetical context. Because these methods rely on respondents stated intentions and not 

their actual choices, the reliability of this approach for providing meaningful estimates for policy 

decisions is questionable. The relevant literature has long noted and thoroughly documented 

the difference between people’s stated intentions and actual behaviors. With respect to 

evaluating the benefits of a national retrofit requirement, preliminary investigations suggest 

extreme sensitivity of aggregate benefits to relatively small changes in willingness-to-pay (WTP) 

estimates (WTP is the metric used to develop nonuse values). The corresponding imprecision 

in aggregated nonuse-value estimates may be the difference between a national rule that is 

justified on a benefit-cost basis and one that is not. The causes of imprecision can be 

categorized in the following three general areas: 

1. Survey Instrument and Sampling Approach 

2. Incorporating Statistical Uncertainty into the Experimental Design 

3. Weighting and Extrapolation of Survey Results

This presentation discusses the potential causes and implication of imprecision in each of these 

areas and identifies ways that they can be addressed to improve the potential validity of national 

estimates. 

Economic and Financial Impacts of a National Retrofit of Closed-Cycle Cooling Systems 

for Fish Protection 

Tuesday, September 6, 2011: 2:00 PM

Matthew F. Bingham, Veritas Economics, Cary, NC 

This presentation describes the economic components of EPRI’s integrated assessment that 

estimates the costs and the economic, reliability, and environmental impacts of a regulation that 

requires converting existing electricity generating units that use once-through cooling to closedcycle cooling. Such a regulation would alter the technology and economics of existing facilities 

that currently use once-through cooling. Some owners would decide to prematurely retire their 

units rather than retrofit, while others would retrofit and operate in the post-regulation 
23

marketplace. The outcomes associated with these compliance and operational decisions 

ultimately register in the financial performance of the electricity industry; the industry’s 

environmental footprint; and the economic welfare of electricity industry employees, consumers, 

and shareholders. Results of the economic assessment including price impacts and unit 

closures are presented for five U.S. electricity markets: Pennsylvania New Jersey Maryland 

Interconnection (PJM), Electric Reliability Council of Texas (ERCOT), Independent System 

Operator-New England (ISO-NE), Midwest Independent System Operator (Midwest ISO), and 

the New York Independent System Operator (NYISO). These results arise from application of 

an economic simulation of these electricity markets. The simulation model employs a 

mathematical representation of economic conditions and behavior. In the model’s market 

simulation, owners of once-through facilities elect to install the new cooling systems if they 

expect the present value of the future stream of profits with closed-cycle cooling to exceed the 

costs of installing and operating the closed-cycle system. 

The Role of Cost-Benefit Analysis in 316(b) BTA Determinations: The Road Ahead 

Tuesday, September 6, 2011: 2:15 PM

David Harrison Jr., NERA Economic Consulting,, Boston, MA

Andrew Foss, NERA Economic Consulting,, Boston, MA

The U.S. Supreme Court ruled in April 2009 that EPA may use (but was not required to use) 

cost-benefit analysis in setting standards and issuing permits under Section 316(b) of the Clean 

Water Act. EPA currently is under a court obligation to issue a proposed 316(b) rule by March 

14, 2011 and a final rule by July 27, 2012. This paper/presentation will consider the future role 

of cost-benefit analysis in making individual Best Technology Available (BTA) determinations, 

taking into account the forthcoming EPA proposal, experience under the prior “wholly 

disproportionate” and “significantly greater” tests as well as relevant developments in California 

and New York. The presentation will consider the following issues: 

 Importance of site-specific considerations for costs and benefits as revealed in detailed 

site-specific assessments; 

 Implications of experience under prior EPA and state implementation of 316(b) costbenefit analysis; 

 Implications of the California and New York policies; 

 Implications of the willingness-to-pay survey that EPA is intending to develop to assess 

potential use and non-use benefits; and 

 Key issues that arise in implementing cost-benefit analysis in 316(b) BTA 

determinations. 

The Use of Closed-Cycle Cooling at New Nuclear Power Stations and Its Potential 

Impact on the Aquatic Environment 

Tuesday, September 6, 2011: 2:30 PM

Michael Masnik, Office of New Reactors, Nuclear Regulatory Commission, Washington, DC

Lance Vail, Hydrology Group, Pacific Northwest National Laboratory, Richland, WA

On December 18, 2001 U.S. EPA published regulations implementing new requirements under 

section 316(b) of the Clean Water Act for large new thermo-electric power facilities. The 
24

regulations establish proportional flow requirements and implement design technologies to 

minimize impingement and entrainment of fish and shellfish. Most importantly the regulation 

has resulted in the adoption of closed-cycle wet cooling systems for almost all proposed thermoelectric power plants including all new nuclear facilities. The effect of this regulation on new 

nuclear station design is discussed. Employing closed-cycle cooling at new facilities and its 

effect on the fishery is considered with an emphasis on the impact of withdrawal and the 

consumptive use of water resulting from the use of evaporative closed-cycle cooling systems.

Because of the significant consumption of water associated with this cooling technology areas 

of the U.S. with high water demand and/or limited supply have experienced difficulty the siting of 

new nuclear facilities. The loss of water results in a loss or alteration of aquatic habitat. This 

and other sources of impact to the fishery due to close-cycle cooling such as impingement, 

entrainment, and thermal effects need to be considered when assessing impact. Opportunities 

for research and monitoring at new power stations are also discussed. 

Results of EPRI's Closed-Cycle Cooling Research Program on Retrofit Costs, Financial 

Impacts, Energy Production, Environmental and Social Impacts and Retrofit 

Environmental Benefits 

Tuesday, September 6, 2011: 2:45 PM

David Bailey, Electric Power Research Institute, Springfield, VA

The Electric Power Research Institute (EPRI) completed a large scale research program to 

inform EPA’s 316(b) Rulemaking on the implications of establishing best technology available 

(BTA) standards based on closed-cycle cooling. The research provides information on five 

issues that include: cost of closed-cycle cooling retrofits, financial impacts, adverse 

environmental and social impacts associated with cooling towers, electric system impacts and 

the benefits of closed-cycle cooling to fish and aquatic life. The closed-cycle cooling retrofit cost 

estimates include capital costs as well as estimates of lost revenue associated with extended 

outages, closed-cycle cooling energy requirements (fans and pumps) and reduced condenser 

cooling efficiency. The financial impacts study estimates the MWs that may be lost as a result 

of premature unit retirements for economic reasons, while the electric system impacts study 

estimates the magnitude and cost of transmission system upgrades that may be necessary to 

avoid localized overloads and voltage violations due to premature unit retirements and energy 

inefficiencies. The research also quantifies environmental and social impacts associated with 

mechanical draft cooling towers and for some parameters estimates the willingness to pay to 

avoid impacts. The results of these studies are then compared to impingement and entrainment 

reduction benefits that are both quantified and monetized.