Off-shore, Mid Depth Velocity Cap

Best Technology Available for Impingement Control

December 2011 December 2011
V l it C D fi iti

Agenda

• Velocity Cap Definition

• U.S. Facilities with Velocity Caps• Summary of Velocity Summary of Velocity Cap Effectiveness ap Effectiveness

• NextEra Energy Seabrook Nuclear• Florida Power & Light Co. St. Lucie Plant• Conclusions

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Velocity Caps Represent BTA for Impingement R

Intake Velocity Cap Definition

A velocity cap is a device that is placed over vertical inleoffshore intakes. This cover converts vertical flow into hflow at the entrance into the intake. The device works opremise that fish will avoid rapid changes in horizontal fpremise that fish will avoid rapid changes in horizontal f

Source: Section 316 (b) EPA TDD for New facilities, Chapter 51. Velocity cap(s) must be designed to ensure that fish a

subjected to horizontal rather then vertical flow from thsubjected to horizontal rather then vertical flow from th

structure.

2. Velocity cap intake flow should be at least 0.5 fps or g

ensure that fish detect the horizontal flow in time to es

3. The velocity cap must be placed in an optimum locat

offshore and in the middle of the water column to reduimpingement and entrainment of aquatic organisms.

4. D t i ti f ti l ti d fl h t 

D

e

termination o

f optimum location an

d flow c

harac

ter

should be determined by the permitting director.

Velocity caps have been deemed BTA by EPA, court proceedi

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Velocity caps have been deemed BTA by EPA, court proceedi

state regulators throughout the U.S.
Velocity Cap Diagram

Velocity cap(s) are designed to ensure that fish are subjected horizontal rather than vertical flow

4

Source: Chapter 6: Technologies and Control Measures § 316(b) Existing Facilities

Proposed Rule ‐ TDD
Velocity Caps Installation at Seabrook Genera

Station 

( ,) Seabrook, NH

)

Off-shore mid-depth velocity caps have been successfully usthroughout the U S

5

throughout the

U.S. 

Source: EPA Proposed Rule, TDD Chapter 6: Technologies and Control Measures § 316(b)

Existing Facilities
U.S. Power Plants with Velocity Caps

Distance Water

Plant State Water Body

From

Shore (ft)

Water

Depth

(ft)

Top of Cap

Depth (ft) Owner Fuel 

San Onofre Units

2

& 3 CA Pacific 3,183 32 SCE Nuclear 

El Se

gundo

3‐4 CA

Santa Monica

g Ba

y

2,611 29 11 NRG Gas 

Huntington Beach 1‐4 CA Pacific Ocean 1,500 17 AES Gas Redondo Beach

5‐8 CA Pacific Ocean 3,000 AES Gas 

Scattergood 1‐3 CA

Santa MonicaBay 1,600 29 11 LA DWP Gas

m

Ormond Beach CA Pacific Ocean 1,950 35 Reliant Gas St. Lucie 1 &

2 FL Atlantic Ocean 1,200 23 12 NEE Nuclear 

Seabrook NH Atlantic Ocean 7,000 60 NEE Nuclear 1

Presque Isle MI Lake Superior 90

0 20 We Energies Coal 

Oswego Steam

5

&

6 NY Lake Ontario NRG Oil 

Nine Mile Point 1 NY Lake Ontario 85

0 Constellation Nuclear 

Nine Mile Point 2* NY Lake Ontario 1,000 Constellation Nuclear 

Kintigh (Somerset) NY Lake Ontario AES Coal 

Ginna NY Lake Ontario 3,100 Constellation Nuclear Edgewater ‐ Unit 5 WI Lake Michigan Alliant Coal 

* 2 velocity caps. Flow 0.5 fpsplus has angled screens to guide fish to bypass the system

9 f th f iliti ith V l it C i C lif i d N 

6

9 o

f the 

facilities with

Velocity 

Caps are in 

C

alifornia an

d

N
Range of Velocity Cap Characteristics

U.S. Facilities with Velocity Caps

g yp

• Velocity Caps are located 900 to 7000 feet from th

plant intakes

• All of the existing velocity caps are located in oce

bays adjacent to oceans, or Great Lakes

– 6 in the Pacific Ocean– 2 in the Atlantic Ocean– 3 in Lake Ontario– 2 in Lake Michigan 2 in Lake Michigan

• Various fuel types are represented

– 3 Nuclear Plants– 5 Gas-fired Plants

– 2 Coal-fired Plants

– 1 Oil-fired Plants

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Summary of Velocity Cap Effectiveness

• Velocity cap studies at the Huntington Beach and El S

Velocity cap studies at the Huntington Beach and El S

Generating Stations in California showed overall reducentrapment (equated to impingement mortality losses) 90 percent

• Two studies at the Scattergood Generating Station inc

measurements conducted pre

‐ and post-installation of 

caps as well as more recent flow reversal studies (EP

LADWP 2007) R lt f th S tt d t d h LADWP 2007). Results 

from the 

Scattergoo

d s

t

u

dy s

h

an overall reduction of 83 percent. 

• Studies at Ormond Generating Station conducted 

concurrently with the Huntington Beach studies democoncurrently with the Huntington Beach studies demo

overall reductions in entrapment of 61 percent during and 87 percent during the day.

In several cases, the reductions in impingement mortality asswith velocity caps were substantial and met or exceeded the impingement mortality performance standard in the proposed rule.

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Studies Show Impingement Reduction of 68 

Summary of Velocity Cap Effectiveness

Plant

Year (s) of

Study

Percent Reduction

‐ Impingement Source of data Com

Seabrook 1990‐98 68% EPA (2002) ‐ Technical Development Document Compared off‐shore v

Seabrook with shorel

Seabrook 2002‐2006 83% NextEra Energy (2008) ‐ Response to EPA Region 1 308 Letter Compared off‐shore v

Seabrook with shorel

83% reduction under 

El Segundo 3‐4 1956‐58 94.5% LADWP ‐ Scattergood Velocity Cap Effectiveness Study; Page 7‐1 Compared pre‐velocit

data

Huntington Beach 1‐4 1979‐80

1979 Day ‐ 90%1979 Night ‐ 53%1979 Aver. ‐ 72%1980 Day ‐ 99%

1980 Night ‐ 87%1980 ‐ Ave. ‐ 93%Overall ‐ 82%

LADWP  ‐ Scattergood Velocity Cap

Effectiveness Study; Page 7‐2,3,4

Comprehensive study 

Results are conservatas silversides, which wreverse operations, w

impingement reducti

effectiveness would h

Scattergood 1‐3 1970‐74 83% LADWP ‐ Scattergood Velocity Cap Effectiveness Study; Page 7‐1. Effectiveness based o

to cooling water flow 

procedures.

Scattergood 1‐3 2006‐07 97.6% in abundance 9 3% i bi LADWP ‐ Scattergood Velocity Cap ff i S d i S

Abundance reduction 

reduction was not du

l hi h bi 

Scattergood 1 3 2006 07 95.3% in biomass Effectiveness Study ‐ Executive Smarmy several high‐biomass 

accounted for 94.2% 

Ormond Beach 1979‐80 87% Daytime 61% Nighttime LADWP ‐ Scattergood Velocity Cap Effectiveness Study

Conducted concurrenStudy ‐ also by U. of W

conservative (effectiv

schools were remove

9

schools were remove

silversides at Hunting
Summary of Velocity Cap Effectiveness

• Seabrook velocity caps approved as BTA following F

NextEra Energy Seabrook Station: Seabrook, New 

Seabrook velocity caps approved as BTA following F

Circuit Court of Appeals Ruling and Regional AdminisApproval.

• Intake located 7,000 feet offshore in 60 feet of water.

• Costs to construct today is likely exceed $250 million 

dollars)–includes velocity caps and intake tunnel whicbored in bedrock 240’ below the ocean floor. 

• Seabrook velocity cap intake averages 0.8 fps appro

rate, allowing fish to detect and avoid the higher horizflow.

• According to the Section 316 (b) Case Studies, Part G

comparing the offshore velocity caps of Seabrook to shore intake for the Pilgrim Plant, Seabrook significa

reduced number of entrained and impinged organism

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reduced number of entrained and impinged organism
Estimated Annual Entrainment and Impingement of Eq

Adult Commercial and Recreational Species 

Seabrook Station, 2002-2006

Species Egg Entrainment Larval Entrainment

Juvenile and Adult

Impingement Total

American lobster 0 0 6 

American plaice 243 233 < 1 47

Hake spp. 122 10 4 13

Silver hake 637 32 60 72

Windowpane 25 8 1,013 1,04Witch flounder 16 32 0 4

Yellowtail flounder <1 <1 2 

Rainbow smelt 0 7,647 1,122 8,76Atlantic cod 73 78 11 16

Atlantic mackerel 408 61 2 47

Haddock <1 <1 <1 Pollock 12 9 121 14Winter flounder <1 1,861 1,327 3,18

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Summary of Velocity Cap Effectivenes

Pl t b ilt H t hi I l d b i i l d

NextEra Energy St. Lucie Nuclear Plant: St. Lucie 

• Plan

t was 

b

uilt on 

H

u

t

chinson Islan

d, a 

barrier islan

d

• Original intake design withdrew water from Big Mud C

the Indian River Lagoon side of the island.

• Further analysis identified optimum option as offshore 

with velocity caps in Atlantic Ocean.

• Final 1973 desi

g yp n included 2 velocit

y ca

ps with 12’ d

pipes (a third pipe, 16’ in diameter was added when Uwas built in 1983). Estimated total cost was $114 MM dollars.

• P i i l fi h S i h k l ki P

rimary commercial fi

s

hes are 

Spanis

h mac

kerel, kin

mackerel, and bluefish. In 1976-1980, only 5 Spanismackerel, 10 king mackerel, and 24 bluefish were co

the intake canal by gillnetting.

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the intake canal by gillnetting.
Summary of Velocity Cap Effectivenes

• Sea turtles entrained in the intake canal are captured

NextEra Energy St. Lucie Nuclear Plant: St. Lucie C

Sea turtles entrained in the intake canal are captured

rehabilitated, if necessary, and returned to the sea.

• EPA deemed Velocity Caps as BTA--“Ecology Branc

staff has been assessin

gp p p 

power 

plant im

pacts over th

decade. There is nothing in the monitoring informatioreviewed that, in our opinion, warrants a detailed 316 study nor the continued monitoring of the intake for fiinvertebrates The design capacity and location of thinvertebrates. The design, capacity and location of th

intake structure of the St. Lucie Plant reflects, in our oBTA for minimizing adverse impacts upon these orga

• The current PSL NPDES permit requires monitoring o

The current PSL NPDES permit requires monitoring o

entrapment in the St. Lucie intake canal. NextEra is to capture and quickly return organisms without caus

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Conclusions

• V l it h hi t i ll b d d BTA 

Velocity caps have historically been deemed BTA 

impingement and entrainment under 316 (b).

• Historical data indicates that velocity caps reduce 

impingement by 68 to 99 percent impingement by 68 to 99 percent.

• EPA has typically agreed that properly placed vel

caps result in reduced entrainment and impingem

• Velocity caps should be considered as a pre-app

Best Technology Available for impingement mortcontrol under EPA’s final 316 (b) rule. 

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