Comprehensive Technical Feasibility and Cost Evaluation Study · Comprehensive Technical Feasibility and Cost Evaluation Study Alcoa Power Generating Inc., a subsidiary of Alcoa Corporation

Comprehensive Technical Feasibility and Cost Evaluation

Study

Alcoa Power Generating Inc., a subsidiary of Alcoa Corporation

Alcoa Warrick Power Plant

Project No. 85014

Final 1/31/2018

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Comprehensive Technical Feasibility and Cost Evaluation

Study

prepared for

Alcoa Power Generating Inc., a subsidiary of Alcoa Corporation

Alcoa Warrick Power Plant Newburgh, Indiana

Project No. 85014

Final 1/31/2018

prepared by

Burns & McDonnell Engineering Company, Inc. Kansas City, Missouri

COPYRIGHT © 2018 BURNS & McDONNELL ENGINEERING COMPANY, INC.

Technical Feasibility and Cost Study Final Table of Contents

Alcoa Warrick Power Plant TOC-1 Burns & McDonnell

TABLE OF CONTENTS

Page No.

1.0 INTRODUCTION ............................................................................................... 1-1 1.1 Final Rule Requirements...................................................................................... 1-2 1.2 Report Organization ............................................................................................. 1-3

2.0 CLOSED CYCLE RECIRCULATING SYSTEMS .............................................. 2-1 2.1 Technical Feasibility ............................................................................................ 2-1

2.1.1 Description of the Technologies Considered ........................................ 2-1 2.1.2 Discussion of Land Availability ........................................................... 2-7 2.1.3 Discussion of Other Available Water Sources ...................................... 2-9 2.1.4 Factors That Make the Technology Impractical or Infeasible ............ 2-14

2.2 Cost Evaluation .................................................................................................. 2-15 2.2.1 Cooling Tower Cost Estimate Methodology ...................................... 2-15 2.2.2 Cooling Tower Cost Estimate Basis ................................................... 2-16 2.2.3 Compliance Costs ............................................................................... 2-18 2.2.4 Social Costs ......................................................................................... 2-19

3.0 FINE MESH MODIFIED TRAVELING SCREENS ............................................. 3-1 3.1 Technical Feasibility ............................................................................................ 3-1

3.1.1 Description of the Technologies Considered ........................................ 3-1 3.1.2 Discussion of Land Availability ........................................................... 3-5 3.1.3 Discussion of Other Available Water Sources ...................................... 3-5 3.1.4 Factors That Make the Technology Impractical or Infeasible .............. 3-6

3.2 Cost Evaluation .................................................................................................. 3-18 3.2.1 Cost Estimate Methodology ................................................................ 3-18 3.2.2 Cost Estimate Basis............................................................................. 3-18 3.2.3 Compliance Costs ............................................................................... 3-20 3.2.4 Social Costs ......................................................................................... 3-21

4.0 FINE MESH CYLINDRICAL WEDGEWIRE SCREENS .................................... 4-1 4.1 Technical Feasibility ............................................................................................ 4-1

4.1.1 Description of the Technologies Considered ........................................ 4-1 4.1.2 Discussion of Land Availability ........................................................... 4-3 4.1.3 Discussion of Other Available Water Sources ...................................... 4-3 4.1.4 Factors That Make the Technology Impractical or Infeasible .............. 4-4

4.2 Cost Evaluation .................................................................................................. 4-10 4.2.1 Cost Estimate Methodology ................................................................ 4-10 4.2.2 Cost Estimate Basis............................................................................. 4-10 4.2.3 Compliance Costs ............................................................................... 4-12 4.2.4 Social Costs ......................................................................................... 4-13

5.0 WATER REUSE AND ALTERNATE SOURCES OF COOLING WATER ........ 5-1



5.1 Technical Feasibility ............................................................................................ 5-1 5.1.1 Description of the Operational Measure ............................................... 5-1 5.1.2 Discussion of Land Availability ........................................................... 5-1 5.1.3 Discussion of Other Available Water Sources ...................................... 5-2 5.1.4 Factors That Make the Technology Impractical or Infeasible .............. 5-2

5.2 Cost Evaluations .................................................................................................. 5-2

6.0 SUMMARY ........................................................................................................ 6-1

7.0 LITERATURE CITED ........................................................................................ 7-1

- COOLING TOWER SKETCH - SOCIAL COST STUDY - MODIFIED TRAVELING SCREEN SKETCHES - CYLINDRICAL WEDGEWIRE SCREEN SKETCH



LIST OF TABLES

Page No.

Table 1-1: Report Organization ............................................................................................... 1-3 Table 2-1: Comparison of Cooling Tower Types and Screening Level Evaluation ................ 2-3 Table 2-2: Cooling Tower Design Basis Summary ................................................................. 2-5 Table 2-3: Municipal Wastewater Sources in the Vicinity of the Alcoa Warrick

Power Plant .......................................................................................................... 2-13 Table 2-4: Estimated Project Costs for Mechanical Draft Cooling Towers .......................... 2-18 Table 2-5: Estimated Cooling Tower Project O&M .............................................................. 2-19 Table 2-6: Total Project Life Cycle Costs ............................................................................. 2-19 Table 2-7: Total Compliance and Social Costs for Mechanical Draft Cooling Towers ........ 2-21 Table 3-1: Estimated Entrainment Reduction using 0.5-mm Fine Mesh Modified

Traveling Screens at AWPP ................................................................................. 3-15 Table 3-2: Estimated Entrainment Reduction using 1.0-mm Fine Mesh Modified

Traveling Screens at AWPP ................................................................................. 3-16 Table 3-3: Estimated Entrainment Reduction using 2.0-mm Fine Mesh Modified

Traveling Screens at AWPP ................................................................................. 3-17 Table 3-4: Estimated Project Costs for Replacement of Existing Screens with

Modified Traveling Screens with a Fish Handling and Return System ............... 3-20 Table 3-5: Total Compliance and Social Costs for Fine Mesh Modified Traveling

Screens ................................................................................................................. 3-21 Table 4-1: Vendor Sizing for Cylindrical Wedgewire Screens ................................................... 4-2 Table 4-2: Field and Laboratory Egg and Larvae Exclusion Rates Using Wedgewire

Screens ................................................................................................................... 4-6 Table 4-3: Mean Density and Standard Deviation of Eggs Collected in Ambient,

Control, and Test Samples ..................................................................................... 4-7 Table 4-4: Mean Density and Standard Deviation of Freshwater Fish Larvae

Collected in Ambient, Control, and Test Samples ................................................. 4-8 Table 4-5: Estimated Entrainment Reduction using 2.0-mm Fine Mesh Cylindrical

Wedgewire Screens at AWPP .............................................................................. 4-10 Table 4-6: Estimated Project Costs for Fine Mesh Cylindrical Wedgewire Screens ............ 4-12 Table 4-7: Estimated O&M for Fine Mesh Cylindrical Wedgewire Screen ............................. 4-13 Table 4-8: Total Project Life Cycle Costs for Fine Mesh Cylindrical Wedgewire

Screens ................................................................................................................. 4-13 Table 4-9: Total Compliance and Social Costs for Fine Mesh Cylindrical Wedgewire

Screens ................................................................................................................. 4-15



LIST OF FIGURES

Page No.

Figure 2-1: Potential Locations for the Mechanical Draft Cooling Towers ............................. 2-8 Figure 3-1: Through-Screen Velocities under Various Debris Loading Conditions ................ 3-7 Figure 3-2: Head Losses under Various Debris Loading Conditions ....................................... 3-8 Figure 3-3: Probability of Retention of Freshwater Drum Larvae on Fine Mesh

Screens at AWPP ................................................................................................. 3-11 Figure 3-4: Probability of Retention of Carpsucker/Buffalo Larvae on Fine Mesh

Screens at AWPP ................................................................................................. 3-12 Figure 3-5: Probability of Retention of Herring Larvae on Fine Mesh Screens at

AWPP ................................................................................................................... 3-12

Technical Feasibility and Cost Study Final List of Abbreviations

Alcoa Warrick Power Plant i Burns & McDonnell

LIST OF ABBREVIATIONS

Abbreviation Term/Phrase/Name

°F degrees Fahrenheit

§ Section

AACE Association for the Advancement of Cost Engineering

ACC air cooled condensers

AIF actual intake flow

APGI Alcoa Power Generating Inc.

ASHRAE American Society of Heating, Refrigeration, and Air Conditioning Engineers

AWPP Alcoa Warrick Power Plant

BOD Biological Oxygen Demand

BTA best technology available

CCRS closed-cycle recirculating system

COD Chemical Oxygen Demand

CWA Clean Water Act

CWIS cooling water intake structures

DCS distributed control system

DIF design intake flow

EM entrainment mortality

EPA U.S. Environmental Protection Agency

EPRI Electric Power Research Institute

FEMA Federal Emergency Management Agency

fps feet per second


Alcoa Warrick Power Plant ii Burns & McDonnell


FRP fiber reinforced plastic

ft feet

gpm gallons per minute

HCD head capsule depth

hp horsepower

HCW horizontal collector well

HVAC heating, ventilation, and air conditioning

IDEM Indiana Department of Environmental Management

IDNR Indiana Department of Natural Resources

IM impingement mortality

in. inches

MGD million gallons per day

mm millimeters

MW megawatt

NPV net present value

NPDES National Pollutant Discharge Elimination System

O&M operation and maintenance

OSHA Occupational Safety and Health Administration

PVC polyvinyl chloride

psig pounds per square inch

TDH total dynamic head

TL total length


Alcoa Warrick Power Plant iii Burns & McDonnell


TSS total suspended solids

USACE U.S. Army Corps of Engineers

WWTP wastewater treatment plants

Technical Feasibility and Cost Study Final Introduction

Alcoa Warrick Power Plant 1-1 Burns & McDonnell

1.0 INTRODUCTION

On August 15, 2014, the U.S. Environmental Protection Agency (EPA) published in the Federal Register

the National Pollutant Discharge Elimination System – Final Regulations to Establish Requirements for

Cooling Water Intake Structures at Existing Facilities and Amend Requirements at Phase I Facilities

(EPA, 2014a). The Final Rule establishes requirements under Section (§) 316(b) of the Clean Water Act

(CWA) to ensure that location, design, construction, and capacity of cooling water intake structures

(CWIS) reflect the best technology available (BTA) for minimizing adverse environmental impacts. The

purpose of this action is to reduce impingement and entrainment of fish and other aquatic organisms at

CWIS used by power generation and manufacturing facilities to withdraw cooling water. The regulations

apply to facilities that use CWIS to withdraw water from waters of the U.S. and have or require a

National Pollutant Discharge Elimination System (NPDES) permit. The Final Rule establishes

requirements for facilities that are designed to withdraw more than 2 million gallons per day (MGD) of

water from waters of the U.S. and use at least 25 percent or more of the water withdrawn exclusively for

cooling purposes.

The Alcoa Warrick Power Plant (AWPP) is a division of Alcoa Power Generating Inc. (APGI), a wholly-

owned subsidiary of Alcoa Corporation. AWPP is a four-unit, 823-megawatt (MW), coal-fueled, steam-

electric power station located in Newburgh, Indiana. The facility uses once-through (open-cycle)

condenser cooling with the Ohio River as the source and receiver of cooling water. APGI wholly owns

three of the four generating stations, which were placed into service in the early 1960s. The largest unit,

Unit 4, is jointly owned by APGI and Vectren Inc., a utility company.

AWPP is a base-load station that generates a continuous supply of electricity throughout the year to

power the Alcoa Warrick Operations manufacturing facility. In addition to electrical power, the power

plant also provides potable water, steam, and high temperature water across the plant. These services are

critical to the various production processes throughout the Warrick Operations manufacturing facility.

The Final Rule applies to AWPP due to the following:

• AWPP has a NPDES permit and is a point source for industrial discharge of wastewater. The

NPDES permit effective date is August 31, 2013, and the permit expiration date is July 31, 2018.

• AWPP uses one CWIS in a once-through cooling water system. The Ohio River is the source and

receiver of the once-through cooling water system. The total DIF at AWPP is 400,000 gallons per

minute (gpm) or 576 MGD. The design intake flow (DIF) of 576 MGD at AWPP is therefore

greater than the 2 MGD criteria. The actual intake flow (AIF) is 518.0 MGD based on data from



January 1, 2010, to December 31, 2014. This time period was selected because it is most

representative of intake flows when the smelter is in operation.

• AWPP uses approximately 91 percent of the water withdrawn from the Ohio River for cooling

water purposes; therefore, the percentage of flow withdrawn from the Ohio River is used

exclusively for cooling purposes is greater than 25 percent criteria.

Because AWPP is subject to the Final Rule, has a DIF that is greater than 2 MGD, and an AIF greater

than 125 MGD, AWPP is required to prepare permit application requirements § 122.21(r)(2) through (13)

for submittal to the Indiana Department of Environmental Management (IDEM).

1.1 Final Rule Requirements The Final Rule under Section (§) 122.21(r)(10), Comprehensive Technical Feasibility and Cost

Evaluation Study, requires the submittal of an engineering study of the technical feasibility and

incremental costs of candidate entrainment mortality (EM) control technologies to support the

determination of site-specific BTA for entrainment (EPA, 2014a). The Final Rule requires that the

evaluation includes the technical feasibility of closed-cycle recirculating systems (CCRS), fine mesh

screens with a mesh size of 2 millimeters (mm) or smaller at the CWIS, and water reuse or alternate

sources of cooling water.

Per the Final Rule at §122.21(r)(10)(i), the technical feasibility of each candidate EM control technology

is to include the following:

(A) A description of all technologies and operational measures considered (including alternative designs of closed-cycle recirculating systems such as natural draft cooling towers, mechanical draft cooling towers, hybrid designs, and compact or multi-cell arrangements).

(B) A discussion of land availability, including an evaluation of adjacent land and acres potentially available due to generating unit retirements, production unit retirements, other buildings and equipment retirements, and potential for repurposing of areas devoted to ponds, coal piles, rail yards, transmission yards, and parking lots.

(C) A discussion of available sources of process water, grey water, waste water, reclaimed water, or other waters of appropriate quantity and quality for use as some or all of the cooling water needs of the facility.

(D) Documentation of factors other than cost that may make a candidate technology impractical or infeasible for further evaluation.

Per the Final Rule at §122.21(r)(10)(iii), facility costs must be adjusted to estimate social costs. Costs

must be presented as the net present value (NPV) and the corresponding annual value, and costs must be

clearly labeled as compliance costs or social costs. The applicant must separately discuss facility level

compliance costs and social costs, and provide documentation as follows:



(A) Compliance costs are calculated as after-tax, while social costs are calculated as pre-tax. Compliance costs include the facility’s administrative costs, including costs of permit application, while the social cost adjustment includes the Director’s administrative costs. Any outages, downtime, or other impacts to facility net revenue, are included in compliance costs, while only that portion of lost net revenue that does not accrue to other producers can be included in social costs. Social costs must also be discounted using social discount rates of 3 percent and 7 percent. Assumptions regarding depreciation schedules, tax rates, interest rates, discount rates and related assumptions must be identified.

(B) Costs and explanation of any additional facility modifications necessary to support construction and operation of technologies considered, including but not limited to relocation of existing buildings or equipment, reinforcement or upgrading of existing equipment, and additional construction and operating permits. Assumptions regarding depreciation schedules, interest rates, discount rates, useful life of the technology considered, and any related assumptions must be identified.

(C) Costs and explanation for addressing any non-water quality environmental and other impacts. The cost evaluation must include a discussion of all reasonable attempts to mitigate each of these impacts.

1.2 Report Organization This report provides the NPDES permit application requirements in the Final Rule under §122.21(r)(10),

Comprehensive Technical Feasibility and Cost Evaluation Study. The report provides a comprehensive

technical feasibility study and cost evaluations for a CCRS, fine mesh traveling screens, fine mesh

cylindrical wedgewire screens, and alternate water sources. A chapter has been devoted for each

candidate EM reduction technology that provides the technical feasibility and cost evaluation of that

technology. Table 1-1 shows the organization of this report.

Table 1-1: Report Organization

Chapter Relevant

Permit Requirement Report Chapter Title 2 §122.21(r)(10)(i) and (ii) Closed Cycle Recirculating Systems 3 §122.21(r)(10)(i) and (ii) Fine Mesh Traveling Screens 4 §122.21(r)(10)(i) and (ii) Fine Mesh Cylindrical Wedgewire Screens 5 §122.21(r)(10)(i) and (ii) Water Reuse and Alternate Sources of Cooling Water 6 N/A Summary 7 N/A Literature Cited

Technical Feasibility and Cost Study Final Closed Cycle Recirculating Systems


2.0 CLOSED CYCLE RECIRCULATING SYSTEMS

The following provides a comprehensive technical feasibility study and cost evaluation of CCRS.

2.1 Technical Feasibility As required in the Final Rule under §°122.21(r)(10)(i), the following provides an evaluation of the

technical feasibility of this technology.

2.1.1 Description of the Technologies Considered Cooling towers are used to reduce the temperature of a water stream by extracting heat from the water and

emitting it to the atmosphere. Evaporating cooling and dry cooling systems are proven technologies that

reduce the amount of intake flow, thereby reducing entrainment and impingement. Closed-cycle cooling

via cooling towers uses 3 to 5 percent of the volume of intake water necessary to operate once-through

cooling systems by recycling the cooling water through the tower and ejecting waste heat to the

atmosphere (EPA, 2014a). EPA estimates that freshwater cooling towers reduce impingement mortality

(IM) and entrainment by 94.9 percent (EPA, 2014a). The actual entrainment reduction is dependent upon

the cooling tower specifications (including the cycles of concentration).

A variety of cooling tower designs may be used to retrofit facilities that currently utilize once-through

cooling systems. These cooling towers may be grouped by several factors (Electric Power Research

Institute [EPRI], 2011a), including:

• Air flow method: natural draft, mechanical forced draft, or mechanical induced draft

• Method of heat transfer: wet, dry, or wet/dry (hybrid) towers

• Air flow direction: counter- or cross-flow

• Arrangement: rectilinear (in-line or back-to-back) or round

Mechanical draft towers use fans to force or draw air through the circulated water. The water falls over

fill surfaces, which helps increase the contact time between the water and the air, maximizing heat

transfer between the two. A portion of the water evaporates, which cools the remainder of the water.

Cooling rates of mechanical draft towers depend upon various parameters, such as fan diameter and speed

of operation and fills for system resistance.

Mechanical draft towers are typically categorized as either forced or induced draft. In a forced draft

tower, the fan is located in the ambient air stream entering the tower, and the air is blown through. Forced

draft towers are characterized by high air entrance velocities and low exit velocities. In an induced draft



tower, the fan is located in the exiting air stream and draws air through the tower. Mechanical draft towers

are available in a large range of capacities and can be grouped together in assemblies of two or more

individual cooling towers or “cells.” Multiple-cell towers can be linear, square, or round depending upon

the shape of the individual cells and whether the air inlets are located on the sides or bottoms of the cells.

Mechanical draft plume-abated towers have very similar designs and operations to non-plume-abated

mechanical draft cooling towers. However, they reduce or eliminate visual plumes by reducing the

exhaust air relative humidity. Plume abatement can be done various ways, specific to each supplier. Some

methods include using coils to cool a portion of the water by a dry method to reduce overall evaporation

and moisture in the exhaust air. Other methods include mixing dry ambient air with the wet air leaving the

tower fill to reduce the moisture in the exhaust air.

Natural draft or hyperbolic cooling towers make use of the difference in temperature between the ambient

air and the hotter air inside the cooling tower. Air flow through this type of tower is produced by the

density differential that exists between the heated (less dense) air inside the tower and the relatively cool

(more dense) ambient air outside the tower (SPX Cooling Technologies, Inc., 2009). Typically, these

towers tend to be quite large (250,000 gallons per minute [gpm] and greater), and occasionally in excess

of 500 feet (ft) in height (SPX Cooling Technologies, Inc., 2009). As hot air moves upwards through the

tower, cooler ambient air is drawn into the tower through an air inlet at the bottom. There are two main

types of natural draft towers (also options for mechanical draft towers):

1. Crossflow tower: air flows horizontally, across the downward fall of water

2. Counterflow tower: air moves vertically upward through the fill, counter to the downward fall of

water (although design depends on specific site conditions).

Crossflow towers require a lower pump head and less maintenance than counterflow towers because of

their simple water distribution system. Operating costs for a crossflow tower are lower than that for a

counterflow tower. However, crossflow towers are less efficient than counterflow towers at rejecting heat

from the water; therefore, crossflow towers are typically larger to compensate for less efficient cooling.

There are two main dry cooling options: direct cooling and indirect cooling. Direct cooling systems,

known as air cooled condensers (ACC), directly transfer heat from the steam to the atmosphere and

condense the steam inside tubes. Indirect cooling systems, sometimes considered air cooled heat

exchangers, transfer heat from the circulating water (inside tubes) to the atmosphere. Both options utilize

fans to increase air flow and heat transfer. Dry cooling performance is based on ambient dry bulb



temperature, while wet cooling tower performance is based on ambient wet bulb temperature.

Consequently, wet cooling typically results in better cooling performance.

A comparison of the cooling tower types is provided in Table 2-1.

Table 2-1: Comparison of Cooling Tower Types and Screening Level Evaluation

Attribute

Cooling Tower Typea Mechanical-

draft Evaporative

Cooling Towers (Base

Case) Mechanical-draft

Plume Abated Wet Natural

Draft Dry Air Cooled

Hybrid (Wet/Dry)

Footprint Area Arranged in one or more rows of single or back-to-back cells or in circles

Arranged in one or more rows of single or back-to-back cells or in circles

Could be larger or smaller depending on separation of mechanical-draft evaporative cooling tower rows.

Largest (2-4 times larger than base case) due to wider air- cooled section; arrangement limited to in-line

Larger (1-3 times larger than base case) due to wider air- cooled section; arrangement limited to in-line

Height Typically 40-60 ft plus 9 ft for fan stack

Typically 40-70 ft plus 9 ft for fan stack

Can approach 500 ft or more

Approx. 2-3 times higher than base case

Approx. 1.5 times higher than base case

Visible Vapor Plume

Lower elevation plume; fogging / icing can occur

Minimal to no visible plume

Higher visible plume; minimal, if any, fogging / icing

None Minimal to no visible plume

Particulate Matter Emission

Base case-depends on TDS, cycles of concentration, and drift eliminator efficiency

Similar to base case


None Less than base case depending on frequency of use for dry portion of tower

Water Consumption

8 to 12 gpm/MW

8 to 12 gpm/MW (could be reduced slightly when plume abatement in operation depending upon manufacturer)


None 1.5 to 12 gpm/MW



Attribute

Cooling Tower Typea Mechanical-

draft Evaporative

Cooling Towers (Base

Case) Mechanical-draft

Plume Abated Wet Natural

Draft Dry Air Cooled

Hybrid (Wet/Dry)

Noise Emission

Base case-fan and cascading water noise


No fan noise; similar water noise to base case

Greatest fan noise; no water noise

Greater fan noise than base case; less water noise

Solid Waste (Sediment)

Base case-depends on water/air quality, basin size, use of dispersing agents



None Similar to or less than base case

Cycle Efficiency

Base case Equal to base case, but reduced when plume abatement in operation

Equal to base case

Lowest; lowest summer output

Lower than base case; lower summer output

Energy Penaltyb

Base case Similar to base case

Less than base case

Higher than base case (highest)

Higher than base case

Capital Cost Base case Higher than base case (approx. 1.5-2 times more)

Higher than base case (approx. 3-5 times more)

Highest (approx. 5-7 times base case)

Higher than base case (approx. 3-5 times more)

Installation Cost/Difficulty

Base case Similar to base case




Operating Cost Base case Similar to but can be slightly higher than base case, depending upon manufacturer

Lower than base case

Highest Higher than base case

Source: EPRI 2011a (a) gpm/MW = gallons per minute per megawatt (b) Energy penalty includes both loss of generation capacity associated with decreased efficiency, and additional power loads associated with operating the modified cooling system (i.e., parasitic loads).

Based on efficiency, economics, and environmental factors, a mechanical-draft evaporative cooling tower

would be the preferred alternative for retrofitting a once-through cooling facility to closed-cycle cooling

at the Alcoa Warrick Power Plant (AWPP). Other types of towers were also considered, but not carried

forward for additional analysis. Circular towers were considered but eliminated because they provided no

apparent additional advantage. Local height ordinances may prevent natural draft towers at this site, and



available space limits their use. Additionally, natural draft towers cost substantially more than

mechanical-draft evaporative cooling towers, but do not provide proportional benefits in other areas,

particularly for power generating stations the size of AWPP. Dry towers are larger, and there may be

insufficient space onsite for these towers. Also, dry towers cost substantially more for procurement and

installation, and result in additional loss of plant performance. The use of hybrid towers, if mandated,

would require a larger footprint than mechanical draft cooling towers, but available space at the site could

preclude use of hybrid towers. Plume-abated towers cost substantially more for procurement than

mechanical draft towers and because of the distance from the conceptual cooling towers to the plant, other

industrial facilities, highway, and residences, plume impacts to these areas are expected to be minimal to

non-existent. Therefore, a mechanical draft cooling tower is the preferred alternative at AWPP, and the

feasibility of a mechanical draft cooling tower is evaluated in the following subsections.

The preliminary design for a mechanical draft cooling tower retrofit at AWPP would include the

installation of two new, back-to-back cooling towers, one with 12 cells and the other with 16 cells. The

conceptual cooling towers (Alternative 1) would be located northwest of the power plants on top of

existing landfills (Figure 2-1). A conceptual sketch is provided in Appendix A. Both cooling towers are

oriented in a northeast direction to be parallel with respect to predominant summer wind, for optimal

performance. The cooling tower design basis for a mechanical draft cooling tower at AWPP is

summarized in Table 2-2. The design wet-bulb temperature used for AWPP is 78.2 °F.

Table 2-2: Cooling Tower Design Basis Summary

Itema Descriptionb Cooling Tower Type Wet cooling, counterflow, mechanical draft cooling tower without plume

abatement. Towers are FRP material with induced fans. Fans

Drives Single speed drives on all fans Horsepower rating 250 hp

Number of cells Units 1 and 3 Tower: 12 cells; Units 2 and 4 Tower: 16 cells Tower dimensions Units 1 and 3 Tower: 350 feet by 110 feet (length x width)

Units 2 and 4 Tower: 475 feet by 110 feet (length x width) Design conditions

Design dry bulb 88.1 °F Design wet bulb 78.2 °F (ASHRAE 1% wet bulb)

Tower design Approach 7 °F



Itema Descriptionb Recirculation allowance

2 °F

Range Units 1 and 3 Tower: 18.6°F; Units 2 and 4 Tower: 20.2°F Water flow rate Units 1 and 3 Tower: 171,100 gpm; Units 2 and 4 Tower: 234,700 gpm Drift 0.0005% Plume abatement Not included Fire protection Not included Lightning protection

Included

Freeze protection Hot water bypass to the basin will be included as well as isolation of individual cells (though not recommended).

Condensers Modifications Install new condenser modules (bundles) for all four unit condensers,

including tubes, tubesheets, waterboxes and structural support. All will be designed for increased system pressure.

Circulating Water Pipe Modifications Reinforce portions of existing pipe near and underneath plant. New pipe

installed elsewhere. Two pipelines, one for each tower. Type C301 Largest diameter 96 inches (U2 and U4) Other Notable Scope Circulating water pumps

Decommission existing circulating water pumps. Install 3 x 50% pumps in Units 1 and 3 tower pump pit. Install 4 x 33% pumps in Units 2 and 4 tower pump pit.

Design flow rate (per pump)

Units 1 and 3 system: 85,600 GPM; Units 2 and 4 system: 78,300 GPM.

Design head (TDH)

>85 ft

Auxiliary cooling system

Replace auxiliary cooling heat exchangers because of increased circulating water temperature and pressure (assumed)

Water treatment Clarification and/or filtration included. Service water tanks included. Wastewater treatment excluded (blowdown routed directly to river).

Raw water source New collector well with redundant supply pumps (if aquifer pump testing confirms feasibility).

Electrical Transformers and associated equipment to feed additional auxiliary loads (a) TDH = total dynamic head (b) FRP = fiber reinforced plastic; hp = horsepower; °F = degrees Fahrenheit; ASHRAE = American Society of Heating, Refrigeration, and Air Conditioning Engineers; gpm = gallons per minute



2.1.2 Discussion of Land Availability Three alternate cooling tower locations were considered for this site (Figure 2-1).

• Alternative 1: Northwest of power plant on existing landfills

• Alternative 2: North of selected area, between laydown and Route 66

• Alternative 3: East of process plant on existing landfill

Alternative 2 was eliminated as a potential location due to its distance from the units and the associated

challenges to route circulating water pipe to and from this location. This location would incur substantial

costs for the circulating water pipe route because of underground utilities and would also place the towers

near the highway, which could result in potential fogging and icing impacts on Route 66.

Alternative 3 was eliminated as a potential location because this area is actively used for storage (clean

fill) of dirt, gravel, and concrete for ongoing construction projects and the placement of a cooling tower

here would require the relocation of this storage. However, there are no other onsite areas for the storage

to be relocated. Additionally, the circulating water pipe route would encounter major obstructions for this

location, which adds costs and risk. This location would also present potential plume impacts on Route

66.

Alternative 1, which was selected as the basis location for this study, presents its own challenges

including its distance from the power plant and the requirement to remove landfill material. However, this

circulating water pipe route would be more feasible than Alternative 3. Existing infrastructure and

underground utilities would need to be relocated or demolished, as appropriate, to accommodate potential

cooling towers and associated piping (Appendix A). Also of important note, a topographical survey of the

proposed area would need to be completed to determine if the existing landfills and proposed location is

within the floodplain. Survey data indicated that this area was above the floodplain. However, the current

FEMA maps indicate the existing landfills are within the one percent floodplain. FEMA maps may not be

indicative of the actual elevations of the site and the proposed location may not actually be in the

floodplain. If the proposed cooling tower location is determined to be within the floodplain, additional fill

will be required.

COPYRIGHT © 2017 BURNS & McDONNELL ENGINEERING COMPANY, INC.

Source: Esri, and Burns & McDonnell Engineering Company, Inc. Issued: 7/14/2017

Path: Z:\Clients\ENS\Alcoa\85014_316b\Studies\Site_Invest\GIS\DataFiles\ArcDocs\Warrick_Plant_DataReview_Sites.mxd kdboatright 7/14/2017Service Layer Credits: Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN, and the GIS User Community

NORTH

1,000 0 1,000500

Scale in Feet

Figure 2-1Potential Locations for the Mechanical Draft

Cooling TowersAlcoa Warrick Power Plant

Alcoa Power Generating, Inc.Warrick County, Indiana

ST66 ST61

GG400

GG350

Arnold Rd

Darl ington Rd

W State Route 66

Alternative 1

Alternative 2

Alternative 3

Alternative SiteU1/U3U2/U4



2.1.3 Discussion of Other Available Water Sources The use of alternative water sources such as process water, gray water, wastewater, and reclaimed water,

could potentially reduce or eliminate surface water withdrawals from the Ohio River, thereby reducing or

eliminating impingement and entrainment at AWPP. Other potential alternative water sources could

include groundwater, agricultural irrigation drainage, mine drainage, and produced water from oil and gas

or mining operations.

Alternative water sources are generally considered potentially feasible as sources of make-up water to

closed-cycle cooling systems such as cooling towers, but typically cannot provide a sufficient quantity for

once-through cooling. The use of an alternative water source also typically requires the installation of

long-distance supply pipelines from the alternate source water location to the power plant and

pretreatment of the water to reduce corrosion, fouling, or scaling problems or to address issues of

wastewater disposal.

Several factors are critical in determining the feasibility of using an alternative water source:

• Source water quantity

• Source water quality and pretreatment

• Distance from the facility

• Land uses and neighborhood characteristics through which the supply and return lines would

have to be installed

• Local regulations

These factors can substantially add to the difficulty and overall cost of the closed-cycle cooling tower

retrofit project.

Alternate water sources to supply makeup water to the cooling tower at AWPP were identified and

evaluated based on the aforementioned critical factors. A new cooling tower at AWPP would require

approximately 9,070 gpm of makeup water supply. Irrigation drainage, produced water, and mine

drainage are not available to the plant. Groundwater and effluent from wastewater treatment plants

(WWTP) are potential alternate water sources for cooling tower makeup and are evaluated below.

2.1.3.1 Groundwater The Ohio River alluvial aquifer underlies the AWPP with the Ohio River in close proximity. Based on the

geologic logs obtained from the Indiana Department of Natural Resources (IDNR), there is substantial

available aquifer thickness with depths to bedrock of approximately 120 feet. Geologic logs of the wells



in the area indicate that the aquifer is primarily medium to coarse sand and gravel. Review of available

information on groundwater wells in the area indicates that yields of 2,500 to 3,000 gpm are common.

Two typical well types are vertical wells or horizontal collector wells. The well logs available near the

AWPP were vertical wells constructed in the Ohio River alluvium. The following provides a brief

description and analysis of each.

Vertical wells are constructed in a borehole drilled vertically through the aquifer to penetrate the water-

bearing portions of the formation. Typically, the lower portion of the well is made of slotted or wire-

wrapped stainless steel screen to allow water to flow into the well. The upper section of the well is steel

or polyvinyl chloride (PVC) casing to contain the pumping equipment. Drawdown occurs when a well is

pumped, and is cumulative between wells. Therefore, appropriate spacing between wells would be

necessary to avoid interference drawdown, which would limit the yield of the wells. The appropriate well

spacing is determined by conducting a pumping test and calculating the conductivity and storativity of the

aquifer. An initial estimate for the required distance at AWPP is 500 feet between wells to keep

drawdown interference below 10 percent of the total drawdown. Four to five vertical wells would be

required to achieve the desired yield of 9,070 gpm and have redundancy for operations and maintenance.

Construction of these wells would require a 36- to 42-inch borehole drilled to bedrock, and installation of

a 24- to 30-inch diameter screen and casing. Each of these wells would require power, pumps, meter

valves, and piping to connect to the cooling tower.

Horizontal collector wells (HCW) utilize a caisson extending to bedrock and slotted or wire wrapped

screens extending horizontally out from the caisson like spokes on a wheel. HCW’s have the advantage of

producing significantly higher volumes of water from a single installation. A single installation minimizes

piping runs to connect the wells, infrastructure associated with multiple well locations, and well

interference concerns. With the available aquifer thickness at the site and transmissive aquifer material

indicated by the well logs, it is likely that a single HCW could yield the required volume of 9,070 gpm for

the cooling tower makeup flow. Redundancy would be achieved by the installation of three, 50 percent

capacity pumps installed in the well (as assumed in the cooling tower design basis). Therefore, a HCW is

recommended at AWPP to provide makeup water to the cooling tower because it minimizes the

infrastructure and operation and maintenance (O&M) requirements for the raw water supply.

2.1.3.2 Wastewater The following provides discussion on the feasibility of using industrial and municipal wastewater at the

Alcoa Warrick Operations facility as potential alternate water sources at AWPP.



Industrial Wastewater

The Alcoa Warrick Operations facility discharges wastewater from the aluminum manufacturing plant.

Based on the uncertainty of the industrial wastewater quality, the treatment requirements and feasibility

for use of this waste stream can greatly vary. If the wastewater source is high in suspended solids or

metals, clarification and filtration are likely required before any use within the cooling tower system.

Another possible issue with this wastewater source is the possibility of high ammonia concentrations.

Conversion of this ammonia by chlorination is needed based on cooling tower limitations. Ammonia in

the wastewater would require significant chlorine feed, and the amount of chlorine fed would increase the

chloride concentration of the water, which could impact the circulating water system materials of

construction and cooling tower cycles of concentration, therefore increasing overall water use. As such,

the use of the industrial wastewater from the aluminum manufacturing plant is not considered feasible due

to the significant amount of treatment that would be required.

Municipal Wastewater

Five municipal wastewater treatment plants are located within 20 miles of the AWPP (Table 2-3).

However, four of these facilities are located 8 to 16 miles away from AWPP. The distance of these

facilities from the AWPP, the industrial and residential neighborhoods through which the supply and

return lines would have to be installed, the dense underground utilities, and the regulations affecting the

project would make their use as alternate water sources very difficult and expensive, particularly as

compared to using groundwater.

The closest municipal wastewater treatment facility is the Newburgh WWTP, located approximately 1.8

miles northwest of AWPP. The Newburgh WWTP design flow is 4.6 MGD. Using this alternate water

source would reduce AWPP’s intake flow by 35 percent; however, several issues with using wastewater

supply exist. Wastewater treatment supplies can be secondary or tertiary treated water. Secondary treated

wastewater is aerated for Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD)

reduction and clarified. Tertiary treatment includes filtration and disinfection following secondary

treatment. If the wastewater source is from a secondary treatment system, then tertiary treatment must be

included at AWPP prior to cooling tower use. Typical filters used for tertiary treatment include

continuously backwashed upflow filters, disc filters, or compressible filters to remove total suspended

solids (TSS) prior to being utilized for cooling tower makeup. Another issue with a wastewater treatment

supply is the possibility of high ammonia concentrations. Conversion of this ammonia by chlorination is

needed based on cooling tower limitations. Ammonia in the wastewater would require significant chlorine

feed, and the amount of chlorine fed would increase the chloride concentration of the water, which could



impact the circulating water system materials of construction and cooling tower cycles of concentration,

therefore increasing overall water use.

Given that the Newburgh WWTP cannot provide 100 percent of the required makeup flow, secondary or

tertiary treatment would need to be completed at AWPP, and several environmental clearances and

road/utility permits and agreements would need to be obtained, groundwater using a single HCW is the

most promising alternate water source for the cooling tower makeup.



Table 2-3: Municipal Wastewater Sources in the Vicinity of the Alcoa Warrick Power Plant

Municipal Wastewater

Plant

Quantity Available

(MGD)

Distance from Plant

(miles) Land Use from Facility to

Source Regulations Affecting Project

Percent Reduction in Cooling

Tower Makeup

Boonville Municipal WWTP

2.9 9.7 Cultivated crops Archeological, wetland, and threatened and endangered species clearances; road and utility permits/agreements

22.2

Chandler Municipal WWTP

8.3 8.0 Industrial, cultivated crops, and residential neighborhoods

Archeological, wetland, and threatened and endangered species clearances; road and utility permits/agreements

63.5

Evansville Eastside WWTP

18.0 13.2 Industrial, cultivated crops, wetlands, and residential neighborhoods


> 100

Evansville Westside WWTP

21.7 16.1 Industrial, cultivated crops, wetlands, and residential neighborhoods


> 100

Newburgh WWTP

4.6 1.8 Industrial, and cultivated crops


35.2



2.1.4 Factors That Make the Technology Impractical or Infeasible In addition to the space requirements associated with the installation of cooling towers, other engineering

factors were considered in the assessment of whether a closed-cycle cooling retrofit is feasible. An EPRI

research program included an independent evaluation of the degree of retrofit difficulty for approximately

125 facilities, and qualitatively categorized whether the retrofit would be relatively “easy, moderate, or

difficult” using the following list of primary factors (EPRI, 2011b):

• Distance between the cooling tower and the main facility and difficulty of tie-ins to existing

structures and components, including auxiliary power for new loads

• Interference from existing underground and overhead utilities

• Suitability of site geology and topography

• Need to reinforce condensers or water supply tunnels

• Need for plume abatement

• Drift deposition on- or off-site

• Need for noise reduction

• Need to bring in alternate sources of makeup water

• Requirements to modify balance-of-plant equipment

• Need to re-optimize the cooling water system

Based on the above factors, a cooling tower retrofit at AWPP is considered difficult. Site-specific

engineering considerations and factors associated with locating cooling towers at AWPP are listed below:

• The significant distance between the proposed cooling tower locations and main plant area would

require long runs of pipe to be installed, which would require shoring and impact potential

unknown underground obstructions.

• Surface material from the landfills and clean fill storage would have to be removed and backfilled

with soil to install the cooling towers. Finding a suitable location for the required quantity of

landfill material would be challenging and expensive. There are no known suitable locations for

the clean fill storage material.

• Due to the increased head/pressure of the system, the circulating water pipe must be replaced or

reinforced with a lining/wrap system. Both options are labor intensive and costly. Furthermore,

reinforcing or replacing the pipe underneath the plant will be difficult because of pipe turns,

unknown undergrounds, and lack of accessibility.



• The proposed cooling tower location (Alternative 1) may be in or encroach on the floodplain.

Prior surveys indicated that the proposed cooling tower location was not in the floodplain.

However, the current Federal Emergency Management Agency (FEMA) maps indicate the

existing landfill is within the one percent floodplain. The FEMA maps may not be indicative of

the actual elevations of the site and the proposed location may not actually be in the floodplain. If

the proposed cooling tower location is determined to be within the floodplain additional fill will

be required. Additional permits may also be required including the Town of Newburgh

Floodplain Development Permit, which could also potentially include hydraulic river modeling

that shows a no-rise to the floodplain elevation. If no-rise is unable to be shown, additional

mitigation options may be required such as additional grading. If the proposed cooling tower

location is determined to be outside or above the one percent floodplain a Letter of Map

Amendment or Letter of Map Revision to FEMA.

Detailed discussions of the following non-water quality environmental and other impacts associated with

retrofitting to a CCRS are discussed in the Non-water Quality Environmental and Other Impacts Study:

• Changes in energy consumption

• Air pollutant emissions

• Human health impacts

• Environmental impacts

• Changes in noise

• Impacts to safety

• Facility reliability

• Changes in water consumption

2.2 Cost Evaluation As required in the Final Rule under §°122.21(r)(10)(iii), the following provides the compliance and social

costs associated with this technology.

2.2.1 Cooling Tower Cost Estimate Methodology An indicative screening level cost estimate (Association for the Advancement of Cost Engineering

[AACE] Class 4) was developed for the conversion of the once-through cooling system to a CCRS. The

estimate was mostly developed based on a parametric model using previous projects and quotes as

reference. Major design parameters (i.e. circulating water flowrate and total steam turbine output)

representing the application at AWPP were utilized to adjust cost factors based on established cost



relationships and functions. Some of the design parameters used to develop the cost estimate are

summarized in Table 2-2. The specific design parameters were not just used to scale or adjust total project

cost. Instead, cost scale factors were applied to all major equipment and major discipline specific

activities to adjust cost groups based on site specific design parameters. Costs were also captured for

differences in scope. All cost groups were combined to develop screening level total direct costs. Area

specific labor rates were considered to adjust associated costs.

Indirect and other costs were determined based on recent similar projects, utilizing percentages as

described in the following sections.

2.2.2 Cooling Tower Cost Estimate Basis The following sections provide the basis for the cooling tower project estimate. The purpose of the

estimate basis is to describe the major scope of the cost items shown in the estimate summaries. The

estimate is based on a multiple-subcontract approach.

2.2.2.1 Direct Costs Total direct costs account for equipment, material, and labor costs for the project. The following provides

the cost estimate basis for each category summarized in Table 2-4.

Equipment

The equipment supply includes the procurement of all major equipment required for conversion of the

once-through cooling system to a CCRS. Table 2-2 summarizes the design basis and major equipment

scope. The following additional minor equipment scope (not included in Table 2-2) is included in the

costs:

• Compressed air

• Chemical feed for cooling tower

• Blowdown pumps and associated equipment

Costs for all equipment were adjusted from reference projects based on equipment specific design

parameters.

Installation Costs and Balance of Plant Modifications

This cost group includes all labor, rental, receiving, and material costs associated with the installation of

the equipment and balance of plant modifications. Local labor rates were used to adjust costs from recent



Burns & McDonnell projects, while several other design parameters were used to adjust costs associated

with quantities and labor productivity. The major plant systems included in the scope of these costs are

summarized in Table 2-2. The scope of these costs includes the following:

• Civil

• Concrete and Deep Foundations

• Piping

• Structural Steel

• Architectural/Buildings

• Electrical

• Instrumentation and Controls

• Demolition

• Miscellaneous

2.2.2.2 Indirect Costs, Contingency, and Owner Costs Indirect Costs

Indirect costs include estimated costs for the following:

• Construction management (including managing of multi-sub contracts) based on size of the

project and recent Burns & McDonnell projects (4.5 percent of direct costs)

• Engineering based on size of the project and recent Burns & McDonnell projects (6 percent of

direct costs)

• Start-up management and materials, based on project size and application

All sales taxes, financing fees, and escalation are excluded from the estimate.

Project Contingency

Project contingency (15 percent of total direct and indirect costs) was included to cover accuracy of

pricing, commodity estimates, and omissions from the defined project scope. This contingency is not

intended to cover changes in the general project scope (i.e. addition of buildings, addition of redundant

equipment, addition of systems, etc.) nor major shifts in market conditions that could result in significant

increases in contractor margins, major shortages of qualified labor, significant increases in escalation, or

major changes in the cost of money (interest rate on loans).



Owner Costs and Contingency

Costs have been included for traditional Owner’s costs (5 percent of total direct costs, indirect costs, and

project contingency) such as project support staff, additional operators, outage time, financing,

permitting, etc. This allowance is based on project experience and size and not based on a specific

buildup of expected Owner costs for this project. Owner contingency was also included as 5 percent of

the total project cost in order to cover potential change orders that could occur over the project duration.

2.2.3 Compliance Costs The following provides the compliance costs associated with this technology.

2.2.3.1 Capital Costs The screening level capital cost for the mechanical draft cooling tower at AWPP is $247 million (Table

2-4). The estimated capital cost is shown in 2017 dollars and represents an indicative screening level cost

estimate, with minimal engineering effort to develop the project design basis. This estimated cost should

not be used for budget planning purposes.

Table 2-4: Estimated Project Costs for Mechanical Draft Cooling Towers

Item Description Cost (2017 Dollars) Total Direct Cost $174,400,000 Equipment $48,800,000 Cooling towers $17,200,000 Installation costs and balance of plant modifications $125,700,000 Total Indirect Cost $20,100,000 Total Direct and Indirect Costs $194,500,000 Project contingency (15%) $29,200,000 Owner cost (5%) $11,200,000 Owner cost contingency (5%) $11,700,000 Total Project Cost $246,600,000

2.2.3.2 Operation and Maintenance Costs Additional annual O&M costs were estimated for the mechanical draft cooling tower at AWPP. The

O&M costs are comprised of two main categories: fixed O&M costs and variable O&M costs. O&M

costs are not inclusive of the entire plant O&M, but are representative of the additional O&M costs for the

operation of added equipment. The O&M impact from the removal of existing equipment (i.e., intake

screens, existing pumps) are not included.



Fixed O&M costs include additional staffing and general maintenance costs, which are estimated as a

percentage of the capital costs and generally include items such as: electronics; controls; electrical

maintenance and replacements; lighting; heating, ventilation, and air conditioning (HVAC); preventative

maintenance for pumps, valves, and any other equipment; and equipment inspections.

Variable O&M costs include water consumption and chemical treatment for collector well water makeup

to the cooling tower and are based on a 90 percent capacity factor. Additional annual fixed and variable

O&M costs are shown in Table 2-5. O&M costs exclude wastewater treatment and escalation.

Table 2-5: Estimated Cooling Tower Project O&M

O&M Cost Type Cost (2017 Dollars) Additional annual fixed O&M costs $2,746,000 Additional annual variable O&M costs $3,246,000

2.2.3.3 Net Present Value Costs The overall life-cycle (net present value [NPV]) project costs were estimated to be $291 million, based on

7 percent rate of return, a 20-year operation life cycle (after project completion), and 3 percent escalation

for capital and O&M (Table 2-6). The NPV cost is based on capital expenditure occurring in 2020 and

operation after project completion starting 2022. These costs do not include estimated lost energy costs

associated with a reduction in generating capacity resulting from the use of a CCRS system and

construction downtime (assumed six-week outage).

Table 2-6: Total Project Life Cycle Costs

Item Description Cost (2017 Cost) Present value of project capital cost $220,000,000 Present value of annual O&M cost adder $70,600,000 Total Life Cycle Project Cost $290,600,000

2.2.4 Social Costs EPA defines social costs as the “opportunity cost to society of employing scarce resources to prevent the

environmental damage otherwise occurring except for the design and operation of compliance technology

(79 Fed. Reg. 158, 48387).” Social costs can be further be delineated as each of the following:

• Real-Resource Compliance Costs—direct purchase, installation, and operation

• Government Regulatory Costs—monitoring, administration, and enforcement



• Environmental Externalities—increased fuel cost impacts from energy penalty and proposed

outages and property value, recreation, human health, and increased water consumption impacts.

Real-resource compliance costs result from purchasing, installing, and operating technologies at AWPP.

As the rule notes, “Any outages, downtime, or other impacts to facility net revenue, are included in

compliance costs, while only that portion of lost net revenue that does not accrue to other producers can

be included in social costs (p. 48,428).” Given AWPP’s expected future market conditions, the analysis

specifies that any entrainment reduction technology will be paid for by retained earnings resulting in lost

net revenues (i.e., producer surplus) that are passed on to shareholders as decreased returns. Shareholders

will experience a consumer surplus loss from their decreased returns which the analysis presents as the

quantified metric of social costs resulting from compliance expenditures. The analysis also quantifies the

increased fuel costs from installing and operating the technology. The analysis does not include estimates

of the lost utility associated with the decreased returns because the shareholders no longer have that

money to spend, nor does it estimate the utility loss from the economic impacts resulting from those

decreased expenditures. Therefore, this component of the analysis underestimates social costs.

Government Regulatory Costs are developed from EPA’s estimates in the Final Rule. As presented in the

EPRI’S report titled An Introduction to Social Costs and Resources for 316(b) Entrainment Evaluations

(EPRI 2015, Product Id: 3002006306), there are numerous social costs from environmental externalities

that can result from implementing and operating entrainment technologies. Deciding which of these to

quantify depends on which are relevant for an individual site and the time and resources available to study

them. For this analysis, based on the site’s characteristics and compliance schedule, the environmental

externalities determined to study were the offsite emissions resulting from conversion-based outages and

operation efficiency losses (evaluated in Veritas’ Power System Capacity Loss and Offsite Emissions

Study).

Social costs were estimated for the installation and operation of the two, mechanical draft cooling towers

at AWPP. The social costs include the expected balance sheet cash reserve decrease, the additional,

system-level fuel costs that would be incurred, and the permitting costs. Capital, O&M, and fuel costs

were treated as pre-tax, and total social costs were estimated as the NPV over the time period using

discount rates of 3 and 7 percent.

The estimated social costs for a CCRS retrofit range from $166.9 to 273.0 million depending on the

discount rate used (Table 2-7). The fourth column of Table 2-7 presents the consumer surplus losses from

passing on decreases in balance sheet cash reserves to shareholders as decreased returns. The fifth column



of Table 2-7 presents increased fuel costs that will be passed on to shareholders as decreased returns.

Appendix B provides the detailed methods and results of the social costs study at AWPP.

Table 2-7: Total Compliance and Social Costs for Mechanical Draft Cooling Towers

Discount Rate

Design, Construction, & Installation

Costsa,b O&M

Costsa,b

Balance Sheet Cash

Reserve Decreasea

Fuel Costsa,b

Permitting Costsb

Total Social

Costsa,b

Annualized Social Costsa

3% $246.6M $6.0M $242.2M $46.6M $75,000 $273.0M $13.7M 7% $246.6M $6.0M $148.1M $46.6M $75,000 $166.9M $8.3M

(a) M = million (b) The engineering, permitting, and fuel costs are undiscounted and in 2017 dollars. The social costs are discounted at

3 and 7 percent.

Technical Feasibility and Cost Study Final Fine Mesh Modified Traveling Screens


3.0 FINE MESH MODIFIED TRAVELING SCREENS

The following provides a comprehensive technical feasibility study and cost evaluations of fine mesh

modified traveling screens.



3.1.1 Description of the Technologies Considered Modified traveling screens are a commercially successful fish collection, handling, and return technology.

Modified traveling screens collect and return impinged organisms to the source waterbody, but they do

not reduce the number of organisms impinged. Modified traveling screens with 3/8-inch mesh do not

reduce entrainment. However, the use of fine mesh screens (< 2-mm) have demonstrated reductions in

entrainment by physically excluding some fish eggs and larvae from being entrained. It should be noted

that organisms that were previously entrained are now physically excluded and impinged on the fine mesh

screens.

This alternative would include the installation of six new traveling screens with a fish handling and return

system at the CWIS. New traveling screens would need to be installed since the existing traveling screens

(six in total) are not suited for retrofitting with buckets. The new screens would be equipped with a

modified bucket system and a low-pressure spray that would gently wash the collected fish out of the

buckets into a separate fish return trough. The return trough would be routed away from the CWIS to

prevent secondary flow circulation and re-impingement. The proposed fish trough discharge could

potentially be located west of the CWIS as shown in Appendix C.

Several features would be considered during the preliminary design of the modified traveling screens and

fish handling and return system, including the following (EPRI, 2015):

• Design flow – Spray wash flow should not be used as the design flow for a fish return because a

large portion of that water may be directed away from the trough. The design flow should be

based on the amount of spray wash flow that is expected in the trough (manufacturer provided)

and any auxiliary flow needed to provide proper hydraulic conditions.

• Combined or separate fish and debris trough – No discernible difference in survival between

combined or separate troughs has been observed. Combined troughs may reduce or eliminate the

need for supplemental flow to increase transport velocity or water depth.



• Open channel or closed conduit – Open channels are recommended to aid in inspection and

maintenance of the fish return. Covers or grating can be used to cover the return trough if

predation by birds or mammals is a concern. Closed conduit pipes may be needed for part or all

of a return, depending on site-specific conditions.

• Pressurized systems – Open channel flow is recommended when feasible. When a pressurized

fish return is needed, fish-friendly pumps should be used, and rapid pressure changes should be

avoided.

• Flow depth – Water depth in the return should be sufficient to totally immerse organisms. A

minimum water depth of 4 to 6 inches [in.]) should be sufficient for most impingeable-sized

organisms (e.g., juvenile fish).

• Water velocity – Water velocities in the return should be higher than the sustained cruising speed

of the conveyed fish to discourage them from residing in the return system. In general, velocities

between 2 and 12 feet per second (fps) should be sufficient, although the ultimate velocity within

the return system will depend on the target species and site constraints. Site characteristics may

require velocities outside of this range. If velocities exceed 12 fps, special attention to pipe and

joint smoothness must be demonstrated by the design. With velocities less than 2 fps, silt and

sand accumulation could potentially become an issue. Velocities greater than 6.6 fps should be

used to reduce the colonization of veligers (mussel larvae) on piping or return line surfaces.

• Slope – The slope should be sufficient to maintain the desired flow and water depth. Steep

downward slopes and long slopes should be avoided. Small vertical drops (less than 4 feet) are

recommended rather than steep downward slopes. Splash shields are recommended at drop

locations to contain water and small fish.

• Shape and width – A minimum return width of 10 in. and freeboard of 6 in. are recommended for

reducing debris plugging and overtopping. Additional freeboard may be needed at curves or

locations of hydraulic jumps or waves.

• Turn radius – When space allows, long radius turns should be used to encourage smooth passage

of debris; however, laboratory studies have demonstrated no adverse effects of tight radii on fish

survival.

• Materials and coatings – The material selected for the fish return should be as smooth as possible

to reduce potential abrasion of organisms. Suitable materials include fiberglass, wood, plastics,

metal, or coated concrete. However, the design should include an allowance for biofouling

(higher surface roughness coefficient) while maintaining adequate water volume and velocities

within the return system. Covers should be used outdoors to reduce biofouling and predation.



• Joints and in-trough structures – The inside of the fish return should be smooth with no sharp

edges or protuberances.

• Discharge location – The discharge location should be selected to return organisms back to the

source waterbody under all expected water levels, prevent re-impingement, and prevent

entrainment in the thermal plume.

• Discharge arrangement – Surface, submerged, and free fall discharges can all provide a safe

return. For free fall discharges, the water depth should be 3 feet or 25 percent of the height of the

drop, whichever is greater.

• Obstructions such as baffles, walls, grates, and rocks should not be placed within the area of the

fish return discharge.

• Debris screening – Installation of any debris screening in the fish return could trap collected

organisms and should be avoided. Screening of the debris return line before combining with the

fish return would not be an issue.

• Temperature – The fish return should be designed to prevent icing or excessive heating. Materials

with low thermal conductivity, insulation, or shading can be used to reduce thermal effects.

• Biofouling control – Where attached biofouling organisms are an issue, redundant return lines

provide a fish-friendly means for biofouling control.

The following is a description of the fish handling and return system that would be installed at AWPP.

Appendix C provides example figures of a typical modified traveling screen and the fish handling and

return system at AWPP.

• Each traveling water screen consists of a continuous series of screen baskets fitted with a smooth

top wire mesh screen deck.

• As the baskets are lifted out of the water, floating and suspended debris are collected on the face

of the wire mesh, while aquatic life are directed into the basket’s trough utilizing a fish catching

system. The smooth, flush mounting of the mesh assists with discharge and encourages

deposition of aquatic life in the basket trough.

• As baskets pass over the head shaft assembly, aquatic organisms are gently discharged from the

basket trough into the fish return system with the aid of gentle, low-pressure sprays. The fish

return system consists of a fiberglass trough which returns aquatic life to the downstream side of

the water source. The trough is designed to maintain a minimum of 6 in. of water while the

screens operate. Following removal of the fish, a high-pressure front spray system cleans the

debris from the face of the wire mesh. A rear seal reduces the potential for debris carry-over.



• The capture mechanism is comprised of unique aquatic life survival baskets; these special

purpose baskets are designed solely for capture and retention of aquatic life without degrading

flows and hydraulics in the intake. Baskets with a deep trough enhance survival potential, and the

shape of this trough assists with capture and discharge. The utilization of smooth-top, slotted

opening mesh provides for increased open areas and reduced velocities, and discourages stapling.

• The release mechanism is comprised of the fish sprays and basket-mesh design. The release

mechanism is primarily the large amount of water in the basket trough that spills out at discharge,

providing a smooth unobstructed slide for aquatic life release. The fish spray is low pressure (10-

15 pounds per square inch gage [psig]) and consists of an outside and an inside spray. The outside

spray acts primarily as a sluicing device, keeping the release path inundated with water. The

inside spray aids in removing the aquatic life off the mesh surface, with the use of gravity, and

discharging the aquatic life into the return mechanism.

• The return mechanism consists of a deep trough system designed to return the aquatic life to the

water source. The trough is typically fabricated from fiberglass and has rounded corners. The

trough is sloped to allow for a minimum of 6 in. of water to remain in the trough during

operation. For preliminary design, it was assumed the return trough is 12 in. wide with a slope of

approximately 0.09 ft./ft. The trough will be above grade with tray supports at 10-ft. spacing.

Covers will be installed on the trough where needed to prevent the removal of aquatic life by

outside predators, such as birds or small mammals. The wetland area adjacent to the fish trough

will be rough graded and a gravel roadway will be installed to allow access to the trough for

routine maintenance and inspection. This return location and access roads will cause both

temporary and permanent impacts to the forested areas and adjacent wetland.

• The modified traveling screens would be continually rotated while the plant is in operation, which

represents a change in historical operation of this equipment. Some evaluation on design life

expectancy should be completed prior to selecting the new screen equipment.

If this technology is selected, a more detailed evaluation of the design criteria will be conducted during

the design phase. Design criteria that will be evaluated in more detail will include:

• Overall return dimensions (length, width, slope)

• Radius of turns in the return trough between the AWPP and the point of discharge

• Planned construction materials including types of covers that will be provided

• Expected rate of water flow in the trough

• Depth of water at the point of discharge



• Height above the water surface for the discharge from the return; including potential extremes in

water elevation (i.e., during floods or extended dry period/drought conditions)

• Proximity to the thermal discharge

• Inspection, cleaning, and monitoring requirements

3.1.2 Discussion of Land Availability Modified traveling screens would be installed in the existing CWIS. Therefore, land availability for the

screens is not an issue. It is assumed the new fish trough will discharge west of the intake structure (see

Appendix C for the potential location). The proposed location of the return discharge considered the

hydraulic zone of influence and thermal discharge as well as selecting a fish return length that minimizes

transport mortality. The return discharge location will be evaluated in further detail during the design

phase (if this technology is selected).

3.1.3 Discussion of Other Available Water Sources Other potential cooling water sources were evaluated in Section 2.1.3. In general, other available water

sources are typically not applicable to the evaluation of fine mesh modified traveling screens because a

once-through cooling water system would continue to be used and the cooling water requirements of

400,000 gpm or 576 MGD would remain the same.

Based on the available aquifer thickness at the site and transmissive aquifer material indicated by the well

logs, a total of 150 vertical wells (producing 3,000 gpm each), or 39 HCWs (producing 15 MGD each)

could yield the required design intake flow requirements of 576 MGD. However, appropriate spacing

between vertical wells to avoid interference drawdown is estimated to be approximately 500 feet and

appropriate spacing between HCWs is estimated to be approximately a quarter mile. This indicates that

appropriately spacing wells through the area will require approximately 9.5 miles of riverbank for the

HCWs and 14.5 miles of riverbank for the vertical wells. Property acquisition and easements for the wells

and associated piping and electrical would be required throughout this area. In addition, due to the

substantial amount of pumping, negative impacts on the pumping levels of surrounding water wells and a

significant water level decline in the aquifer could occur. Given the number of wells required, negative

impacts on surrounding wells and in the aquifer, need for property acquisition or easements, and the

number of environmental clearances and road/utility permits and agreements that would need to be

obtained, the use of wells as an alternate water source for the screening systems that would continue to

use once-through cooling would be excessively expensive to implement, and is considered infeasible.



WWTPs near AWPP do not provide sufficient quantity for once-through cooling. Based on the design

intake flow of 576 MGD at AWPP, the amount of flow reduction using the Newburgh WWTP (4.6 MGD)

would be 0.8 percent. This very low percentage does not warrant the use of this water source and is

considered infeasible.

3.1.4 Factors That Make the Technology Impractical or Infeasible Several factors are necessary to consider in the assessment of whether fine mesh screens are feasible. The

following provides an evaluation of three primary factors (intake flow velocity, head loss, and biological

effectiveness) that influence the feasibility or the ease/difficulty of implementing and operating fine mesh

modified traveling screens. Three screen mesh sizes were evaluated: 0.5, 1.0, and 2.0 mm.

3.1.4.1 Intake Flow Velocity and Head Loss Flow velocity through the screen is an important design consideration for intake screening systems (EPA,

2004). While the approach velocity is more critical to fish impingement, the through-screen velocity is

important in determining how difficult it is for fish to remove themselves from the screen once impinged.

Intake velocity is important because fish formerly entrained will now be impinged on the screens.

Head loss is caused by friction between and constriction of the water flowing through the screens and the

screening material and debris on the screens. For a given pumping rate and overall screen area, reducing

the screen open area as a result of employing a finer mesh or clogging by debris will increase through-

screen velocity, and head loss will increase because friction is proportional to the square of velocity.

Large head losses can lower the water surface elevation at the circulating water pump suction piping to

the point at which pump vortexing and cavitation can occur or even to where the plant can be tripped

offline. Head losses also create hydrostatic forces against the screens which could result in screen failure

when the forces exceed design limits.

Decreasing screen mesh size reduces the effective open area of the mesh because the screen material

occupies an increasing proportion of the screen area. High debris loading and screen clogging, which is

very likely with fine mesh screens at AWPP if not continually rotated, further reduces effective open area

and can have a substantial effect on the through-screen velocities and head loss. The through-screen

velocity and head loss was estimated for the screen mesh sizes of 0.5, 1.0, and 2.0-mm and the existing

mesh size at 0, 25, 50, and 75 percent clogging (Figure 3-1; Figure 3-2). For the purposes of this study, it

was assumed all screens are 10 ft. wide and submerged 31.46 ft. at low water level to match the existing

conditions.



As effective open area decreased from the 2-mm screen to the 0.5-mm mesh, through-screen velocity

increased. The fine mesh screens would increase the through screen velocities as compared to the existing

screens and are higher than the IM reduction standard (0.5 fps), ranging from 1.1 fps for 2-mm screens to

1.7 fps for 0.5-mm screens at 25 percent clogging (Figure 3-1). It is possible to increase the screen

footprint for smaller mesh sizes in order to reduce through-screen velocities; however, significant

modifications to the existing intake structure would be required which leads to additional costs and outage

time for installation, and reduces the feasibility of the option. Furthermore, the Final Rule does not

require that fine mesh traveling screens meet the 0.5 fps criteria for entrainment mortality.

Figure 3-1: Through-Screen Velocities under Various Debris Loading Conditions

As through-screen velocity increases, so does head loss. The new screens are designed for a static head of

3 feet with a maximum deflection of ¼ inch. Based on existing drawings, the current screen frames have

enough capacity to withstand the additional forces generated by using a finer mesh screen. Over the range

0.0

1.0

2.0

3.0

4.0

5.0

6.0

0% 25% 50% 75%

Velo

city

(fps

)

Percent Clogged

0.5 X 0.5 mm1 X 1 mm2 X 2 mmExisting ScreenEPA Standard



of clogging evaluated, none of the mesh sizes would exceed the 3-foot static head design limit (Figure

3-2).

Figure 3-2: Head Losses under Various Debris Loading Conditions

Based on the through-screen velocity and head loss calculations, installing the 0.5, 1, or 2 mm fine mesh

screens at AWPP is technically feasible; however, the clean screen, through-screen velocities are higher

than the EPA 0.5 fps criterion and the existing intake screens. The increase in the through-screen

velocities will likely increase IM at AWPP.

3.1.4.2 Biological Effectiveness As mesh sizes are reduced to prevent entrainment, organisms previously entrained become impinged on

the screens (i.e., “converted” from entrainable to impingeable) and are subjected to spray washes and

return along with larger impinged organisms and debris from the screens (EPA, 2014b). The biological

effectiveness of fine mesh modified traveling water screens for reducing IM and entrainment is dependent

upon: 1) the ability of the screens to physically exclude fish eggs and larvae from entering the cooling

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

0.0% 25.0% 50.0% 75.0%

Head

Los

s (in

ches

)

Percent Clogged

0.5 X 0.5 mm1 X 1 mm2 X 2 mmExisting ScreenDesign Limit



water system; and 2) the post-collection transfer survival of those impinged fish eggs and larvae.

Entrainment reductions from physical exclusion (or retention) and survival on the modified traveling

screens and in the handling and return systems is a function of the species, life stage, and organism size

and could be dependent on several other factors including screen and return system material, screen

rotation speed and frequency, through-screen velocity, return flume velocity, drop height, length of the

fish return, and water quality (EPA, 2014b). In general, fragile life stages and species have higher

mortality than more robust life stages and species. For fine mesh modified traveling screens, the survival

of each species/life stage must be evaluated against the survival that would result if that organism instead

passed through coarse-mesh screens and the circulating water system. For some species/life stages,

impingement on fine-mesh screens can result in higher mortality than if the organism were entrained

through the circulating water system (EPRI, 2012). Two steps were conducted to estimate the biological

effectiveness of fine mesh modified traveling screens at AWPP:

1. Estimate entrainment reductions through retention (the number of fish eggs and larvae

physically excluded by the traveling screens and retained on the screen)

2. Estimate the post-collection survival of those retained fish eggs and larvae

The following discusses the methods used during to estimate retention and post collection survival to

estimate overall biological effectiveness of fine mesh modified traveling screens.

3.1.4.2.1 Entrainment Reductions Through Retention In general, retention of eggs and larvae increases with decreasing screen mesh size and increasing fish

egg width and larval length (EPRI, 2010). Limited data existing on the retention of fish eggs and larvae

on fine mesh modified traveling screens. In lieu of empirical data, the estimated retention of fish eggs and

larvae was assessed using egg diameters and the ratio of larval total length (TL) to head capsule depth

(HCD). Although most of the body parts of fish larvae are soft and easily compressible at the early larval

stages of development when they are susceptible to entrainment, the head capsule has harder cartilage and

bone that is not compressible (Tenera Environmental, 2013). As such, the HCD can be used to represent

the minimum size that larvae could pass through a fine-mesh screen opening. Uncertainty is associated

with this method, however, because the orientation of larvae at the time of contact with the screen may

result in the exclusion of an organism that could physically fit through the mesh (EPRI, 2014b).

Furthermore, this method does not account for the behavioral response to the screens or the swimming

capabilities of the late larval and juvenile life stages. Thus, the HCD method tends to under estimate

retention and overall biological effectiveness.



As discussed in the Entrainment Characterization Study at AWPP, the most abundant and susceptible

species of fish at AWPP are freshwater drum, Asian carp, carpsucker/buffalo, and herring (Clupeidae

including gizzard shad). Asian carp were excluded from this estimate because it is a non-native, invasive

species. Eggs collected as part of the Entrainment Characterization Study were identified as either

freshwater drum or unidentifiable. Based on the morphometric data on eggs, egg width ranged from 1.0 to

2.0-mm. Therefore, a screen mesh size of 0.5 mm and 1.0-mm would physically exclude 100 percent of

the freshwater drum and unidentifiable eggs. A 2.0-mm screen would physically exclude less than 2

percent of the eggs.

Morphometric data collected for these three taxa collected during AWPP’s Entrainment Characterization

Study and the EPRI (2014) HCD method were used to estimate the retention of larvae using 0.5-, 1.0-,

and 2.0-mm mesh sizes. Linear regressions were determined using the relationship of observed TL to

HCD and then used to interpolate HCDs for fish larvae of a given length. Probabilities of exclusion were

then derived by integrating estimated HCDs and the associated standard deviations under a normal curve.

Probabilities were calculated over a size range (for example 1.0 to 1.9 mm) up to 25 mm in length. The

results of the HCD method are provided in Figures 10-4 to 10-6 for freshwater drum, carpsucker/buffalo,

and herring larvae.

The results of the HCD method indicate the following:

• The 0.5-mm mesh would physically exclude freshwater drum greater than or equal to 3 mm in

length (Figure 3-3). Based on the available morphometric data, 99 percent of the freshwater

larvae would be retained. Carpsucker/buffalo larvae greater than or equal to 7 mm in length

would be physically excluded, or 100 percent (Figure 3-4). Herring larvae greater than or equal to

9 mm in length would be physically excluded, or 100 percent (Figure 3-5).

• The 1.0-mm mesh would physically exclude freshwater drum larvae greater than or equal to 6

mm in length (Figure 3-3). Based on the available morphometric data, greater than 86 percent of

the freshwater drum larvae would be retained. Using the larval data at AWPP, the HCD method

indicates that carpsucker/buffalo larvae less than 10-mm and herring larvae less than 11-mm in

length would not be physically excluded by 1.0-mm mesh screens (Figure 3-4 and Figure 3-5).

Carpsucker/buffalo larvae entrained at AWPP ranged from 7.0- to 8.5-mm in length and herring

larvae ranged from 9.8- to 10.0-mm in length indicating that carpsucker/buffalo and herring

larvae at AWPP would not be excluded using 1.0-mm mesh screens. However, as mentioned, the

HCD method tends to under estimate retention. To be conservative, it is assumed that 40 percent

of carpsucker/buffalo and herring larvae will be retained.



• The 2-mm mesh would physically exclude freshwater drum greater than or equal to12 mm in

length (Figure 3-3). Based on the available morphometric data, greater than 36 percent of the

freshwater drum larvae would be retained. Based on the available morphometric data, no

freshwater drum were collected that were greater than 12-mm. Using the larval data at AWPP, the

HCD method indicates that carpsucker/buffalo larvae less than 17-mm and herring larvae less

than 16-mm in length would not be physically excluded by 2.0-mm mesh screens (Figure 3-4 and

Figure 3-5). Carpsucker/buffalo larvae entrained at AWPP ranged from 7.0- to 8.5-mm in length

and herring larvae ranged from 9.8- to 10.0-mm in length indicating that carpsucker/buffalo and

herring larvae at AWPP would not be excluded using 2.0-mm mesh screens. However, as

mentioned, the HCD method tends to under estimate retention. To be conservative, it is assumed

that 20 percent of carpsucker/buffalo and herring larvae will be retained.

Therefore, the smaller the mesh size, the higher probability of retention and thus a higher reduction in

entrainment. However, the survival rate of the those previously entrained that are now impinged is

important in evaluating the overall effectiveness of the fine mesh modified traveling screens, as discussed

in the next section below.

Figure 3-3: Probability of Retention of Freshwater Drum Larvae on Fine Mesh Screens at AWPP

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Prob

abili

ty o

f Ret

entio

n

Larval Length (mm)

Probability of Retention (0.5-mm)





Figure 3-4: Probability of Retention of Carpsucker/Buffalo Larvae on Fine Mesh Screens at AWPP

Figure 3-5: Probability of Retention of Herring Larvae on Fine Mesh Screens at AWPP

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Prob

abili

ty o

f Ret

entio

n

Larval Length (mm)

Probability of Retention (0.5-mm)Probability of Retention (1.0-mm)Probability of Retention (2.0-mm)

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Prob

abili

ty o

f Ret

entio

n

Larval Length (mm)

Probability of Retention (0.5-mm)Probability of Retention (1.0-mm)Probability of Retention (2.0-mm)



3.1.4.2.2 Post Collection Survival and Overall Biological Effectiveness The post collection survival of fish eggs and larvae off 0.5-, 1.0-, and 2.0-mm fine mesh screens was

assessed using the mean annual entrainment estimate at AWPP, egg mortality rates from EPA (2004),

larval entrainment survival rates on fine mesh traveling screens by EPRI (2009; 2010), and impingement

survival of juveniles and adults on conventional modified traveling screens by EPRI (2003).

• Egg mortality was assumed to be 100 percent for entrained eggs and 20 percent for those that

were converted from entrained to impinged. EPA found that nearly 100 percent of eggs were

entrained unless the mesh slot size was less than 2 mm, and mortality of eggs “converted” to

impingement ranged from 20 to 30 percent (2004).

• Larval survival on fine mesh screens was estimated using larval lengths measured during the 2-

year entrainment characterization study at AWPP and survival rates from EPRI (2009, 2010). An

evaluation of fine mesh traveling screens was completed by EPRI at Alden Research Laboratory

from 2007 to 2009. In the EPRI study, the 48-hour post-collection survival of the larvae

converted to impingement off the 0.5 and 1.0-mm fine mesh screens was extremely poor

(generally less than 30 percent regardless of screen type). All of the larvae converted to

impingement were assumed to have the highest survival rate of 30 percent.

• In the EPRI study, the 48-hour post-collection survival of the larvae converted to impingement

off the 2.0-mm ranged from 0 to approximately 60 percent when larval length was less than 12.0

mm and exceeded 90 percent when size exceeded approximately 12.0 mm. Survival of larvae

greater than 12 mm collected off the 2.0-mm screens was likely higher because the larvae

impinged and subsequently collected off the 2.0-mm mesh size were larger and had developed

musculature and some scales, decreasing their sensitivity to impingement and handling stress.

Analyzing the larval length data from the 2-year entrainment characterization study determined

that 96.1 percent of the larvae were less than 12-mm and 3.9 percent of the larvae were greater

than 12-mm. Therefore, all of the larvae converted to impingement were assumed to have the

highest survival rate of 60 percent.

• Juveniles and adults that were formerly entrained will all be impinged. Impingement mortality

was estimated based on species and family specific, extended survival rates on conventional

traveling screens (EPRI, 2003).



Using the estimated egg and larval retention and mortality assumptions, the overall effectiveness

(reduction in EM) of the 0.5, 1.0, and 2.0-mm fine mesh traveling screens at AWPP is estimated to be 50,

25, and 20 percent, respectively (Table 3-1; Table 3-2; Table 3-3).



Table 3-1: Estimated Entrainment Reduction using 0.5-mm Fine Mesh Modified Traveling Screens at AWPP

Life Stage / Taxa Size (mm) Exclusion

Point (mm)a

Average Entrainment (2015-2016)

Fraction Physically Excluded

Estimated Annual

Entrainment Converted to Impingement

Estimated Entrainment

Survival


Mortality

Estimated Impingement

Survival


Mortality Effectiveness

(Percent) Eggs

Freshwater drum 1.25 - 1.5 0.5 2,825,798 1.00 0 2,825,798 0.0 0 0.80b 565,160 80.0

Unidentified eggs 1.25 - 2.0 0.5 2,772,142 1.00 0 2,772,142 0.0 0 0.80 b 554,428 80.0 Subtotal

5,597,940

0 5,597,940

0

1,119,588 80.0

Larvae

Freshwater drum 4.0 - 12.0 >3 159,546,946 0.99 1,595,469 157,951,477 0.0 1,595,469 0.30 c 110,566,034 29.7

Carpsucker/Buffalo 7.0 - 9.0 >7 28,283,322 1.00 0 28,283,322 0.0 0 0.30 c 19,798,326 30.0

Clupeidae (incl. gizzard shad) 7.0 - 12.0 >9 19,339,024 1.00 0 19,339,024 0.0 0 0.30 c 13,537,317 30.0

Other 5.0 - 12.0

60,771,883 1.00 0 60,771,883 0.0 0 0.30 c 42,540,318 30.0 Subtotal

267,941,175

266,345,705

1,595,469

130,364,359 50.8

Juveniles

Catfish

82,961 1.00 0 82,961 0.0 0 0.56 d 36,503 56.0

Cyprinidae (including Notropis, and emerald shiner)

1,749,774 1.00 0 1,749,774 0.0 0 0.67 e 577,425 67.0

Freshwater drum

3,000,316 1.00 0 3,000,316 0.0 0 0.66 f 1,035,109 65.5

Gizzard shad

6,562,810 1.00 0 6,562,810 0.0 0 0.13 g 5,683,393 13.4

Herrings (including Clupeidae and skipjack herring)

8,696,554 1.00 0 8,696,554 0.0 0 0.13 g 7,531,215 13.4

Temperate bass (including striped bass)

498,721 1.00 0 498,721 0.0 0 0.34 h 328,657 34.1

Suckers

20,480 1.00 0 20,480 0.0 0 0.67 i 6,799 66.8

Sunfish/bluegill

21,237 1.00 0 21,237 0.0 0 0.71 j 6,137 71.1

Subtotal

20,632,852

0 20,632,852

0.0

15,205,240 26.3 Total

294,171,967

0 292,576,498

1,595,469

146,689,187 49.6

(a) The exclusion point for eggs is assumed to be the mesh size. The exclusion point for are total length, derived based on an analysis of head capsule depth (HCD) to total length measurements (b) Estimated egg survival in EPA (2004) (c) Estimated larval survival in EPRI (2009, 2010) (d) Average extended survival for Ictaluridae in EPRI (2003) (e) Average extended survival for Cyprinidae EPRI (2003) (f) Average extended survival for Sciaenidae in EPRI (2003) (g) Average extended survival for Clupeidae in EPRI (2003) (h) Average extended survival for Percichthyidae in EPRI (2003) (i) Average extended survival for Catostomidae in EPRI (2003) (j) Average extended survival for Centrarchidae in EPRI (2003)





Point (mm)a



Estimated Annual Entrainment

Converted to Impingement


Survival


Mortality


Survival



(Percent) Eggs Freshwater drum 1.25 - 1.5 1.0 2,825,798 1.00 0 2,825,798 0.0 0 0.80b 565,160 80.0 Unidentified eggs 1.25 - 2.0 1.0 2,772,142 1.00 0 2,772,142 0.0 0 0.80 b 554,428 80.0

Subtotal 5,597,940 0 5,597,940 0 1,119,588 80.0 Larvae Freshwater drum 4.0 - 12.0 >6 159,546,946 0.86 22,336,572 137,210,374 0.0 22,336,572 0.30 c 96,047,262 25.8

Carpsucker/Buffalo 7.0 - 9.0 >10 28,283,322 0.40 16,969,993 11,313,329 0.0 16,969,993 0.30 c 7,919,330 12.0 Clupeidae (including gizzard shad) 7.0 - 12.0 >12 19,339,024 0.40 11,603,414 7,735,610 0.0 11,603,414 0.30 c 5,414,927 12.0

Other 5.0 - 12.0 60,771,883 0.40 36,463,130 24,308,753 0.0 36,463,130 0.30 c 17,016,127 12.0 Subtotal 187,830,268 148,523,703 39,306,566 103,966,592 23.7

Juveniles Catfish 82,961 1.00 0 82,961 0.0 0 0.56 d 36,503 56.0

Cyprinidae (including Notropis, and emerald shiner) 1,749,774 1.00 0 1,749,774 0.0 0 0.67 e 577,425 67.0

Freshwater drum 3,000,316 1.00 0 3,000,316 0.0 0 0.66 f 1,035,109 65.5

Gizzard shad 6,562,810 1.00 0 6,562,810 0.0 0 0.13 g 5,683,393 13.4 Herrings (including Clupeidae and skipjack herring) 8,696,554 1.00 0 8,696,554 0.0 0 0.13 g 7,531,215 13.4

Temperate bass (including striped bass) 498,721 1.00 0 498,721 0.0 0 0.34 h 328,657 34.1

Suckers 20,480 1.00 0 20,480 0.0 0 0.67 i 6,799 66.8

Sunfish/bluegill 21,237 1.00 0 21,237 0.0 0 0.71 j 6,137 71.1

Subtotal 20,632,852 0 20,632,852 0.0 15,205,240 26.3 Total 214,061,061 0 174,754,495 39,306,566 120,291,420 25.4






Point (mm)a



Estimated Annual Entrainment

Converted to Impingement


Survival


Mortality


Survival



(Percent) Eggs Freshwater drum 1.25 - 1.5 2.0 2,825,798 0.00 2,825,798 0 0.0 2,825,798 0.80 0 0.0

Unidentified eggs 1.25 - 2.0 2.0 2,772,142 0.02 2,716,699 55,443 0.0 2,716,699 0.80 11,089 1.6

Subtotal 5,597,940

5,542,497 55,443

5,542,497

11,089 0.8 Larvae Freshwater drum 4.0 - 12.0 >12 159,546,946 0.36 102,110,046 57,436,901 0.0 102,110,046 0.60 c 22,974,760 0

Carpsucker/Buffalo 7.0 - 9.0 >10 28,283,322 0.20 22,626,658 5,656,664 0.0 22,626,658 0.60 c 2,262,666 0

Clupeidae (incl. gizzard shad) 7.0 - 12.0 >16 19,339,024 0.20 15,471,219 3,867,805 0.0 15,471,219 0.60 c 1,547,122 0

Other 5.0 - 12.0 60,771,883 0.20 48,617,506 12,154,377 0.0 48,617,506 0.60 c 4,861,751 0 Subtotal 187,830,268 63,093,565 124,736,703 25,237,426 20.2

Juveniles Catfish 82,961 1.00 0 82,961 0.0 0 0.56 d 36,503 56.0

Cyprinidae (including Notropis, and emerald shiner) 1,749,774 1.00 0 1,749,774 0.0 0 0.67 e 577,425 67.0

Freshwater drum 3,000,316 1.00 0 3,000,316 0.0 0 0.66 f 1,035,109 65.5

Gizzard shad 6,562,810 1.00 0 6,562,810 0.0 0 0.13 g 5,683,393 13.4

Herrings (including Clupeidae and skipjack herring) 8,696,554 1.00 0 8,696,554 0.0 0 0.13 g 7,531,215 13.4

Temperate bass (including striped bass) 498,721 1.00 0 498,721 0.0 0 0.34 h 328,657 34.1

Suckers 20,480 1.00 0 20,480 0.0 0 0.67 i 6,799 66.8

Sunfish/bluegill 21,237 1.00 0 21,237 0.0 0 0.71 j 6,137 71.1

Subtotal 20,632,852 0 20,632,852

0.0

15,205,240 26.3 Total 214,061,061 5,542,497 83,781,860

130,279,200

40,453,755 20.2




3.2 Cost Evaluation As required in the Final Rule under §122.21(r)(10)(iii), the following provides the compliance and social


3.2.1 Cost Estimate Methodology An indicative screening level cost estimate (AACE Class 4) was developed for replacing the existing

traveling screens with fine mesh modified traveling screens. The estimate was developed using vendor

quotes for major equipment (i.e. screens) and using data from previous projects for the installation and

balance of plant modifications. Indirect and other costs were determined based on recent similar projects,

utilizing percentages as described in the following sections.

3.2.2 Cost Estimate Basis The following sections provide the basis for the fine mesh modified traveling screen cost estimate. The

purpose of the cost estimate basis is to describe the major scope of the cost items shown in the estimate

summaries.



Equipment

The equipment supply includes the procurement of all major equipment required for replacing the existing

traveling screens, which includes:

• Six, fine mesh modified traveling screens (10 ft. basket width, 71 ft. well depth)

• High pressure spray pump (one debris removal spray header per screen) and associated

equipment

• Low pressure spray pump (two spray headers per screen – one to spray fish as they pass over the

head sprocket and one to transfer fish from the basket to the return trough) and associated

equipment

• Vertical turbine pumps (2 x 100 percent; 2,500 gpm) to supply makeup water to the fish return

trough

There was not a significant difference in screen equipment pricing for the varying fine mesh sizes of this

magnitude; however, should APGI choose to replace the existing coarse-mesh traveling screens with fine-

mesh screens, there are certain performance and operational impacts that should be considered. For



example, as mesh size decreases, the available open area also decreases (assuming the footprint of the

intake is not altered) which leads to an increase in through-screen velocity which will likely increase

impingement rates at AWPP.




Burns & McDonnell projects, while other design parameters were used to adjust costs associated with

quantities and labor productivity. The scope of these costs includes the following:

• Setting/removing stop logs (six bays)

• Installing the fish return trough (approximately 300 linear feet and includes site prep, supports

(above-grade), concrete and deep foundations)

• Demolishing existing trash screens (six total) and debris trough

• Installing piping associated with spray wash and fish return pumps

• Electrical

• Instrumentation and controls

• Miscellaneous

It was assumed that the existing wiring and controls at the intake will be compatible with the new

equipment and that no modification or repair to the existing traveling screen frames would be required.

3.2.2.2 Indirect Costs, Contingency, and Owner Costs The following sections describe indirect costs, project contingency, and Owner costs and contingency for

the fine mesh modified traveling screens.

Indirect Costs


• Construction management based on size of the project and recent Burns & McDonnell projects (8

percent of direct costs)


direct costs)

• Start-up management and materials (2 percent of direct costs)

All sales taxes and financing fees are excluded from the estimate.



Project Contingency



intended to cover changes in the general project scope nor major shifts in market conditions that could

result in significant increases in contractor margins, major shortages of qualified labor, significant

increases in escalation, or major changes in the cost of money (interest rate on loans).


Costs have been included for traditional Owner’s costs (5 percent of total direct and indirect costs) such

as project support staff, additional operators, outage time, financing, permitting, etc. Owner contingency

(5 percent of total direct and indirect costs) was also included to cover potential change orders that could

occur over the project duration.


3.2.3.1 Capital Costs The estimated capital cost for replacing the existing traveling screens with six, fine mesh modified

traveling screens is $9.0 million (Table 3-4). All costs are provided in 2017 dollars.

Table 3-4: Estimated Project Costs for Replacement of Existing Screens with Modified Traveling Screens with a Fish Handling and Return System

Item Description Cost (2017 Dollars) Total Direct Cost $5,472,000

Equipment cost $2,595,000 Installation costs and balance of plant modifications $2,877,000

Total Indirect Cost $1,204,000 Total Direct and Indirect Costs $6,676,000 Contingency (25%) $1,670,000 Owner Cost (5%) $340,000 Owner Contingency (5%) $340,000 Total Project Cost $9,026,000

3.2.3.2 Operation and Maintenance Costs O&M costs will vary for each mesh size based on the debris loading and other site-specific conditions.

O&M costs assumed one screen replacement every five years and 2 percent of the direct costs for routine



maintenance for the screens and the fish return system. Annual O&M costs for routine maintenance were

estimated to be approximately $250,000 for each screen mesh size.

3.2.3.3 Net Present Value Costs The overall life cycle (NPV) project costs were estimated to be $10.4 million (2017 dollars), based on 7

percent rate of return, a 20-year operation life cycle (after project completion), 3 percent escalation for

capital, and 3 percent escalation for O&M. For the purposes of this estimate, it was assumed the work can

occur during a typical plant outage, and therefore no outage revenue losses are included in the NPV cost.

The NPV cost is based on capital expenditures occurring in 2020 and operation after project completion

starting in 2020.

3.2.4 Social Costs Social costs were estimated for the installation and operation of fine mesh traveling screens at AWPP.

The social costs include the expected balance sheet cash reserve decrease, the additional, system-level

fuel costs that would be incurred, and the permitting costs. Capital, O&M, and fuel costs were treated as

pre-tax, and total social costs were estimated as the NPV over the time period using discount rates of 3

and 7 percent.

The estimated total social costs for the installation and operation of fine mesh modified traveling screens

at AWPP range from $6.2 to $9.7 million depending upon the discount rate used (Table 3-5). Appendix B

provides the detailed methods and results of the social costs study at AWPP.

Table 3-5: Total Compliance and Social Costs for Fine Mesh Modified Traveling Screens

Discount Rate

Design, Construction, &

Installation Costsa,b

O&M Costsb

Balance Sheet Cash

Reserve Decreasea

Fuel Costsb

Permitting Costsb

Total Social

Costsa,b

Annualized Social Costsb

3% $9.0M $250,000 $9.7M $191,000 $15,000 $9.7M $484,400 7% $9.2M $250,000 $6.1M $191,000 $15,000 $6.2M $308,000

(a) M = million (b) The engineering, permitting, and fuel costs are undiscounted and in 2017 dollars. The social costs are discounted at

3 and 7 percent.

Technical Feasibility and Cost Study Final Fine Mesh Cylindrical Wedgewire Screens


4.0 FINE MESH CYLINDRICAL WEDGEWIRE SCREENS

The following provides a comprehensive technical feasibility study and cost evaluations of fine mesh

cylindrical wedgewire screens.



4.1.1 Description of the Technologies Considered Cylindrical wedgewire screens are a passive intake system. To achieve the optimal reduction in

impingement and entrainment, the slot size must be small enough to physically exclude the entrainment of

the organisms. Also, a low through-slot velocity should be maintained, and a sufficient ambient current

must be present to aid organisms in bypassing the structure and to remove other debris from the screen

face (EPA, 2004). When appropriate conditions are met, these screens exploit physical and hydraulic

exclusion mechanisms to achieve consistent reductions in impingement (and, as a result, IM) and

entrainment (EPA, 2014b). The typical design consists of wedge-shaped wires or bars welded to an

internal cylindrical frame that is mounted on a central intake pipe, with the entire structure submerged in

the source waterbody.

In general, two alternatives are available to retrofit the existing CWIS to cylindrical wedgewire screens:

1. Mount cylindrical wedgewire screens on collector pipes on the bottom of the waterbody. The

collector pipes are routed back to the CWIS. A wall is constructed at the face of the CWIS, and

the collector pipes would penetrate the wall to transfer water to the existing pumps through the

existing intake bays.

2. Construct a bulkhead wall in the waterbody in front of the existing CWIS, with wedgewire

screens mounted on individual pipes penetrating the wall to transfer water to the impoundment in

front of the existing CWIS, which remains unmodified except for the removal of the screens. This

alternative was not considered further. River data for the Newburgh Lock and Dam indicates that

flood stage is approximately 368 ft. with historic crests above 380 ft. If a bulkhead wall is

constructed, it would need to be built above the historical flood levels in order to prevent aquatic

life and debris from entering the intake system, in addition to modifying the existing concrete

cells which have a top elevation of 365 ft. Based on this information, this alternative was

determined not to be cost effective for AWPP.



The size and number, and thus, feasibility for the cylindrical wedgewire screen arrangement are directly

related to the intake flow requirements, slot size, and desired through slot velocity. In addition, the size of

the screens would be limited by the available water depth outside the intake canal. Based on the intake

rate and available water depth at AWPP, a screen vendor has recommended the use of 96-inch diameter

screens for the fine mesh option. Vendor sizing for various mesh sizes is as provided in Table 4-1. For

fine mesh screens, the number of screens (and therefore total screen length) is increased in order to meet

the velocity requirements for the AWPP intake rate. For this analysis, 0.5, 1.0 and 2.0 mm mesh were

evaluated. The wedgewire screen array at AWPP was designed to have a maximum through-screen design

intake velocity of less than 0.5 fps, thereby minimizing impingement and complying with IM Option 2.

Table 4-1: Vendor Sizing for Cylindrical Wedgewire Screens

Item Description 2-mm Fine

Mesh 1-mm Fine

Mesh 0.5-mm Fine

Mesh Screen diameter (inches) 96 96 96 Screen length (feet) 26.42 27.25 28.00 Number of screens 9 13 20 Total screen length (feet) 237.75 354.25 560.00

The 2-mm mesh cylindrical screens would provide the smallest footprint in the Ohio River. A total of 9

screens are required to meet the intake flow requirements for 2.0 mm slot size and achieve 0.5 fps

through-screen velocity at low river flow (see conceptual sketch in Appendix D). Each screen would be

96 inches in diameter and a length of 26.42 feet. These screens will be connected to a header pipe and two

collector pipes, all of which will be supported by piles. The two collector pipes will be fitted to a steel

plate at the CWIS. An airburst system would be provided to assist in cleaning the screen surfaces. The

airburst system would include an accumulator, distributor system, control systems, and air compressor.

Cleaning cycles would be initiated automatically with a timer or differential head sensor. In addition, the

wedgewire screens would include a coating or alloy material to inhibit biofouling.

If this technology is selected for further consideration at AWPP, APGI will need to contact the U.S. Army

Corps of Engineers (USACE) and U.S. Coast Guard to discuss the feasibility of permitting this

installation. These agencies may not allow the installation of this submerged CWIS on the Ohio River

because of conflicts with navigation and recreational boating, or may have additional requirements that

could impact the CWIS design.



4.1.2 Discussion of Land Availability Land availability for fine mesh cylindrical wedgewire screens is not typically an issue because the major

equipment, such as the screens, are located in the source water body. The only land-based equipment

includes the air backwash system controls, compressors and air receivers, which are sometimes housed in

an individual equipment building. At AWPP, the equipment would likely be housed inside the

maintenance building located behind the CWIS (Appendix D).

4.1.3 Discussion of Other Available Water Sources Other potential cooling water sources were evaluated in Section 2.1.3 and 3.1.3. In general, other

available water sources are typically not applicable to the evaluation of cylindrical wedgewire screens at

AWPP because a once-through cooling water system would continue to be used. The cooling water

requirements of 400,000 gpm or 576 MGD of water would remain the same.

Based on the available aquifer thickness at the site and transmissive aquifer material indicated by the well

logs, a total of 150 vertical wells (producing 3,000 gpm each), or 39 HCWs (producing 15 MGD each)

could yield the required design intake flow requirements of 576 MGD. However, appropriate spacing

between vertical wells to avoid interference drawdown is estimated to be approximately 500 feet and

appropriate spacing between HCWs is estimated to be approximately a quarter mile. This indicates that

appropriately spacing wells through the area will require approximately 9.5 miles of riverbank for the

HCWs and 14.5 miles of riverbank for the vertical wells. Property acquisition and easements for the wells

and associated piping and electrical would be required throughout this area. In addition, due to the

substantial amount of pumping, negative impacts on the pumping levels of surrounding water wells and a

significant water level decline in the aquifer could occur. Given the number of wells required, negative

impacts on surrounding wells and in the aquifer, need for property acquisition or easements, and the

number of environmental clearances and road/utility permits and agreements that would need to be

obtained, the use of wells as alternate water source for the required volume would be excessively

expensive to implement, and is considered infeasible.

WWTPs near AWPP do not provide sufficient quantity for once-through cooling. Based on the design

intake flow of 576 MGD at AWPP, the amount of flow reduction using the Newburgh WWTP (4.6 MGD)

would be 0.8 percent. This very low percentage does not warrant the use of this water source and is




4.1.4 Factors That Make the Technology Impractical or Infeasible Several factors were considered in the assessment of whether fine mesh cylindrical wedgewire screens are

feasible. The following are primary factors that would influence the feasibility or the ease/difficulty of

implementing and operating fine mesh cylindrical wedgewire screens:

4.1.4.1 Engineering and Operational Challenges The number of screens required and the location of the screen array on the collector pipes pose numerous

engineering and operational challenges.

• Navigational hazards to commercial and recreational boating.

• Screen damage from commercial vessels would require screen replacement at unknown intervals.

• Screen damage from commercial vessels could occur, thereby impacting the ability to obtain

sufficient cooling water.

• Significant permitting difficulties would need to be overcome.

• Debris loading and biofouling would clog screens and increase slot velocity, reducing screen

effectiveness in reducing IM and EM.

• Construction of the wedgewire screens would impact AWPP operations and processes and

shutdown AWPP for an estimated 3 weeks. A substantial shutdown period would be required

even if the construction coincided with a scheduled shutdown.

• Extensive site preparation (potential dredging).

• Maintenance would be highly problematic due to debris loading, biofouling, and winter icing.

• Impacts to the Ohio River bottomlands would occur.

The significant footprint of the screens in the Ohio River and associated permitting are the most critical

factors at AWPP. The screens, located outside the existing canal, will pose navigational hazards to

commercial and recreational boating, and would require a USACE nationwide permit and include

USACE’s and U.S. Coast Guard’s review and approval. The 0.5-, and 1.0-mm mesh sizes are considered

to be infeasible because the they require too large of a footprint in the Ohio River, encroach on the

navigation channel and interfere with commercial boating, and would likely not be permitted by the

USACE. The number of screens required to have a maximum through-screen velocity of 0.5 fps was 13

for 1.0-mm slot width, and 20 for 0.5-mm slot width. It is likely that only the 2.0-mm slot width would

potentially be feasible but even that size required 9 screens. Also, the USACE would be very unlikely to

agree to the installation of a bulkhead wall, or permanent construction of these screens beyond the face of

the existing CWIS due to concerns with interference with navigation, and future channel dredging

operations.



Although an air backwash system would be provided in an attempt to clean the screen surfaces, and the

wedgewire screens would include a coating or alloy material to inhibit biofouling, the backwash system

and coating is not expected to eliminate the debris loading at AWPP; therefore, debris loading could be

problematic and inhibit the wedgewire screens from operating properly. Debris at the AWPP consists of

driftwood, plastic trash, tires, corn stalks, and grass and occurs during flooding. Currently, the trash rake

is operated during flooding when large amounts of drift wood are pulled into the intake. The existing

traveling screens are protected by the trash rake; however, the cylindrical wedgewire screens would be

susceptible damage by this large debris because they will be located outside the canal. Also, any reduction

in the effective open area of the screens would increase through-slot velocities and potentially increase

impingement and entrainment from clean conditions.

4.1.4.2 Estimated Biological Effectiveness When appropriate conditions are met, cylindrical wedgewire screens exploit physical and hydraulic

exclusion mechanisms to achieve reductions in impingement (and, as a result, IM) and entrainment (EPA,

2014b). Cylindrical wedgewire performance data from several installations, as well as laboratory

evaluations, suggest a strong potential to reduce impingement impacts when certain design and

construction criteria are satisfied (EPA, 2014b). Data from some studies have shown reductions in

impingement of near 100 percent. In-situ observations have shown that impingement is virtually

eliminated using wedgewire screens (Hanson, 1981; Lifton, 1979; Browne et al., 1981).

Several field and laboratory studies of fine slot width cylindrical wedgewire screens have been completed

to evaluate their effectiveness in reducing entrainment (Table 4-2). The overall effectiveness of

wedgewire screens varied depending on biological (species, morphology, size) and engineering (slot

width and velocities) parameters. The following are general conclusions based on the observed

differences between ichthyoplankton densities entrained through an open (control) port and the test

screens:

• Entrainment densities decreased with a smaller slot width.

• Slot velocities tested (0.5 and 1.0 fps) did not have a significant effect on entrainment density.

• Larval entrainment densities in both control (no intake screen) and test (with screen) conditions

typically increased as ambient velocity increased, whereas egg entrainment densities were

unaffected by ambient velocity.

• Larval entrainment density decreased with larval length.

• For species with larger head widths, the difference between control and test entrainment densities

was greater.



Table 4-2: Field and Laboratory Egg and Larvae Exclusion Rates Using Wedgewire Screens

Facility and Location

Wedgewire Slot Size

(mm)

Percentage of Egg Exclusion

(all species)

Percentage of Larval Exclusion

(all species) Referencea Test Facility, Gwynns Island, VA 0.5 19 – 87 58 – 72 EPRI, 2006b Test Facility, Sakonnet River, RI 0.5 92 – 99 72 – 82 EPRI, 2005 Test Facility, Portage River, OH 0.5 93 – 98 NA EPRI, 2005 Test Facility, Brooklyn, NY 0.5 91 NA Henderson et

al., 2003 Test Facility, Gwynns Island, VA 1.0 12 36 – 53 EPRI, 2006b Test Facility, Sakonnet River, RI 1.0 8 – 27 9 – 18 EPRI, 2005 Test Facility, Portage River, OH 1.0 17 – 96 NA EPRI, 2005 Chalk Point Steam Electric Station, Aquasco, MD

1.0 NA 80 Weisberg et al., 1987

Carrol County Station, Mississippi River, IL

1.0 77 74 Otto et al., 1981

Oyster Creek Nuclear Generating Station, Forked River, NJ

1.0 93 93 Browne et al., 1981

Seminole Generating Station, St. John River, FL

1.0 NA 99 EPA, 2004

Laboratory Study 1.0 NA 65 Hanson, 1981 Laboratory Study 1.0 98 96 Hanson et al.,

1977 Oyster Creek Nuclear Generating Station, Forked River, NJ

2.0 92 92 Browne et al., 1981

J. H. Campbell Plant Units 1 and 2, Lake Michigan, MI

2.0 67 84 Zeitoun et al., 1981

Chalk Point Steam Electric Station, Aquasco, MD


Seminole Generating Station, St. John River, FL

2.0 NA 62 EPA, 2004

Chalk Point Steam Electric Station, Aquasco, MD


(a) Full references available in the Literature Cited chapter of this document.

EPRI conducted field evaluations of fine slot width wedgewire screens to examine entrainment rates of

naturally occurring fish species and life stages at three sites with unique hydraulic and environmental

conditions (EPRI, 2005; EPRI, 2006b). A field evaluation was completed at the mouth of the Portage

River (EPRI, 2005). This site was considered representative for AWPP because the freshwater river

species used in the study were similar to, or the same as those entrained at AWPP, including freshwater



drum and shad (Clupeidae spp.). Testing was conducted daily in May and June 2004. For eggs, control

entrainment densities were 93 percent greater than test entrainment densities for all test conditions except

for the slot width of 1.0 mm and slot velocity of 1.0 fps (Table 4-3). The 0.5-mm screen significantly

reduced the entrainment of eggs by 98 percent at slot velocities of 0.5 fps and 93 percent at slot velocities

of 1.0 fps. The difference among these test conditions was likely the result of extrusion of eggs through

the larger slots at a higher velocity. A 96 percent reduction at 0.5 fps with the 1.0-mm screen was

observed; however, the reduction of egg entrainment at 1.0 fps with the 1.0-mm screen was only 17

percent.

Table 4-3: Mean Density and Standard Deviation of Eggs Collected in Ambient, Control, and Test Samples

Slot Width (mm)

Slot Velocity

(fps)

Mean Number of Eggs Entrained per 100 m3 (Standard Deviation)

Control-Treatment

Percent Differencea Ambient Control Test

0.5 0.5 72.3 (130.2) 45.1 (81.5) 1.1 (3.1) 97.5 (7)b 1.0 91.5 (199.8) 42.0 (81.0) 2.8 (4.3) 93.2 (10)b

1 0.5 74 (118.5) 102.9 (200.0) 4.5 (5.8) 95.7 (10)c 1.0 737.7 (1,806.4) 117.2 (224.1) 97.1 (195.5) 17.1 (9)

Source: EPRI, 2005 (a) Calculated as [(control density minus test density) divided by control density]. Positive values indicate lower densities in test samples. (b) Indicates a statistically significant difference between test and control densities (p < 0.05). (c) p = 0.06

The results for larval exclusion were highly variable, depending upon slot size, slot velocity, and

morphology. For carp (Cyprinus spp.), a significant difference between test and control densities was

found for the 1.0 mm screen at a slot velocity of 1.0 fps. No significant differences between test and

control densities were observed in any of the other test conditions. For shad larvae (including gizzard

shad and alewife), a 98 percent reduction in entrainment was observed for the 0.5-mm screen at a slot

velocity of 0.5 fps for fish between 7 and 9 mm long (Table 4-4). The 1.0-mm screen with a slot velocity

of 1.0 fps only produced a 47 percent reduction in entrainment of shad larvae between 4 and 6 mm long.

For freshwater drum, there were no significant reductions in entrainment for any test conditions despite

the large differences between the treatment and control densities. At a slot velocity of 0.5 and 1.0 fps, a

96 percent reduction in entrainment was observed for a slot size of 0.5 mm. A 72 percent reduction was

observed for a slot size of 1.0 mm at a slot velocity of 1.0 fps. For temperate basses (Morone spp.), the

percent difference between test and control densities was greater than 65 percent for all test conditions.



Table 4-4: Mean Density and Standard Deviation of Freshwater Fish Larvae Collected in Ambient, Control, and Test Samples

Slot Width (mm)

Slot Velocity

(fps)

Larval Length (mm)

Mean Number of Larvae Entrained per 100 m3 Control-Treatment

Percent Differencea

(Standard Deviation) Ambient Control Test

Carp (Cyprinus spp.) 0.5 0.5 NA 0.3 (0.9) 2.2 (5.6) 2.7 (7.2) -22.1 (7)

1 NA 0.0 (0.0) 1.5 (2.9) 1.1 (1.5) 22.3 (6) 1 0.5 NA 3.6 (7.4) 1.3 (2.5) 2.1 (3.7) -65.5 (6)

1 NA 12.4 (25.2) 6.0 (9.3) 2.7 (5.1) 54.3 (7)b Freshwater drum

0.5 0.5 NA 1.6 (4.2) 2.5 (5.5) 0.1 (0.2) 96.4 (4) 1 NA 43.1 (131.5) 14.2 (36.4) 0.6 (1.6) 95.9 (4)

1 0.5 NA 19.7 (52.0) 0.0 (0.0) 0.1 (0.3) N/Ac 1 NA 199.3 (549.6) 9.9 (19.9) 2.8 (5.5) 71.7 (2)

Shad (Clupeidae spp.) 0.5 0.5 ≤ 3 46.4 (83.5) 51.6 (91.6) 59.6 (127.2) -15.5 (9)

4 – 6 662.5 (884.2) 88.2 (62.4) 57.1 (94.4) 35.2 (8) 7 – 9 535.1 (1,017.7) 8.4 (9.5) 0.1 (0.4) 98.2 (5)b ≥ 10 28.4 (69.5) 0.0 (0) 0.0 (0) N/Ac All 1,272.6 (1,931.4) 148.2 (148.6) 116.9 (220.3) 21.1 (9)

1 ≤ 3 182.3 (357.5) 72.7 (98.8) 63.9 (90.6) 12.1 (10) 4 – 6 822.3 (1,591.5) 138.4 (122.2) 53.1 (50.4) 61.6 (10)b 7 – 9 373 (790.9) 28.8 (51.6) 6.3 (9.9) 78.1 (6) ≥10 10.6 (24.9) 4.5 (11.2) 0 (0) 100 (2) All 1,388.3 (2,365.2) 244.4 (182.4) 123.3 (125.3) 49.5 (10)b

1 0.5 ≤ 3 83.4 (139.2) 97.2 (92.4) 54.4 (75.9) 44.0 (7) 4 – 6 1,902.5 (3,036.2) 497 (1,061.2) 455.9 (1,119.4) 8.3 (7) 7 – 9 237.1 (323.2) 20.7 (39.2) 0.8 (1.5) 96.1 (5) ≥ 10 3.9 (9.3) 0.0 (0) 0.0 (0) N/Ac All 2,226.9 (3,304) 614.9 (1,109.7) 511.1 (1,097.7) 16.9 (7)

1 ≤ 3 158.7 (158.6) 283.9 (371.9) 382.4 (574.5) 34.7 (9) 4 – 6 937.9 (1,367.7) 269.8 (230.9) 142.9 (168.9) 47 (9)b 7 – 9 56.3 (56.4) 17.6 (26.1) 5.6 (11.2) 68 (4) ≥ 10 4.2 (8.4) 0.0 (0) 0.0 (0) N/Ac All 1,157.2 (1,320.3) 571.3 (533.5) 530.9 (628.3) 7.1 (9)



Slot Width (mm)

Slot Velocity

(fps)

Larval Length (mm)

Mean Number of Larvae Entrained per 100 m3 Control-Treatment

Percent Differencea

(Standard Deviation) Ambient Control Test

Temperate basses (Morone spp.) 0.5 0.5 NA 15.3 (25.6) 1.6 (2.3) 0.5 (1.1) 67.7 (6)

1 NA 15.2 (40.3) 0.7 (1.5) 0.2 (0.5) 65.7 (4) 1 0.5 NA 38.2 (83.9) 0.4 (1.2) 0.0 (0.0) N/Ac

1 NA 21.6 (35.9) 0.4 (0.8) 0.0 (0.0) 100.0 (2) Source: EPRI, 2005 (a) Calculated as [(control density minus test density) divided by control density]. Positive values indicate lower densities in test samples. (b) Indicates a statistically significant difference between test and control densities (p < 0.05). (c) Insufficient data for meaningful comparison.

Based on the highly variable laboratory and in-situ results for the fish species, the estimated effectiveness

of 0.5-, 1.0-, and 2.0-mm fine slot width screens at AWPP is uncertain. In general, the smaller the mesh

size, the higher the probability to physically exclude the eggs and larvae which results in higher

effectiveness. The benefit of the cylindrical wedgewire screens over the modified traveling screens is that

the eggs and larvae formerly entrained that are now impinged could potentially be removed off the

screens by the ambient river sweeping velocity or blown off by the airburst system.

The use of 0.5-mm mesh cylindrical wedgewire screens at a design through-screen velocity of 0.5 fps at

AWPP would reduce entrainment more than the other two screen slot sizes. Based on the results from

EPRI (2005), the use of 0.5-mm mesh cylindrical wedgewire screens could potentially reduce egg and

larval entrainment by 98 and 96 percent, respectively. The use of 1.0-mm fine mesh at a design through-

screen velocity of 0.5 fps at AWPP would reduce egg and larval entrainment by 96 and 72 percent,

respectively. The biological effectiveness of using 2.0-mm fine mesh at a design through-screen velocity

of 0.5 fps at AWPP is even more difficult to estimate because of the lack of recent effectiveness data and

data on the potential for eggs and larvae to be extruded through the larger slot width. Based on

morphometric data collected as part of the 2-year Entrainment Characterization Study (not accounting for

hydraulic mechanisms of cylindrical wedgewire screens), the 2-mm mesh would not physically exclude

freshwater drum eggs and freshwater drum larvae less than 17 mm in length (Figure 3-3), and

carpsucker/buffalo and herring larvae less than 12-mm in length (Figure 3-5; Figure 3-5). However, data

on 2-0-mm fine mesh cylindrical wedgewire screens indicate egg entrainment reductions from 67 to 92

percent and larval entrainment reductions from 62 to 84 percent (see Table 4-2). Given the size of the fish

eggs and larvae at AWPP, entrainment reductions using 2.0-mm fine mesh screens is anticipated to be on

the lower side of these ranges (67 percent for eggs and 64 percent for larvae). Using the mean entrainment



estimates at AWPP (excluding Asian carp) and the aforementioned egg and larval reductions, the overall

entrainment reduction at AWPP using 2.0-mm fine mesh cylindrical wedgewire screens is 65 percent

(Table 4-5).

Table 4-5: Estimated Entrainment Reduction using 2.0-mm Fine Mesh Cylindrical Wedgewire Screens at AWPP

Life Stage Mean Annual Entrainment

Estimated Percent

Reduction

Estimated New

Entrainment Eggs 5,597,940 67a 1,847,320 Larvae 241,737,797 62b 91,860,363

Juveniles 20,605,438 100c 0 Adults 0 100c 0 Total 267,941,175 93,707,683 Percent Entrainment Reduction 65.0

(a) Estimated egg exclusion in Zeitoun et al. (1981) (b) Estimated larval exclusion in EPA (2004) (c) Assumed all juveniles and adults would be physically excluded based on size.

4.2 Cost Evaluation As required in the Final Rule under §°122.21(r)(10)(iii), the following provides the compliance and social


4.2.1 Cost Estimate Methodology An indicative screening level cost estimate (AACE Class 4) was developed for replacing the existing

traveling screens with fine mesh cylindrical wedgewire screens. The estimate was developed using vendor

quotes for major equipment (i.e. screens) and using data from previous projects for the installation and

balance of plant modifications. Indirect and other costs were determined based on recent similar projects,

utilizing percentages as described in the following sections.

4.2.2 Cost Estimate Basis The following sections provide the basis for the cylindrical screen estimate. The purpose of the estimate

basis is to describe the major scope of the cost items shown in the estimate summaries.





Equipment

The equipment supply includes the procurement of all major equipment required for replacing the existing

traveling screens, which includes:

• Cylindrical wedgewire screens and support structure

• Airburst system (includes accumulator, distributor system, control systems, air compressor and

piping to each screen drum)




Burns & McDonnell projects, while several other design parameters were used to adjust costs associated

with quantities and labor productivity. The scope of these costs includes the following:

• Setting stop logs (six bays)

• Demolishing existing bar screen (six total)

• Supplying/installing buoys

• Installing piles for intake pipes

• Installing blanking plate for intake structure

• Installing piping associated with intake, airburst system, and warm water line

• Electrical

• Instrumentation and controls

• Miscellaneous

It was assumed that the existing wiring and controls at the intake will be compatible with the new

equipment.

4.2.2.2 Indirect Costs, Contingency, and Owner Costs The following summarizes the indirect costs, contingency, and owner costs for fine mesh cylindrical

wedgewire screens.

Indirect Costs


• Construction management based on size of the project and recent Burns & McDonnell projects (8

percent of direct costs)




direct costs)

• Start-up management and materials (2 percent of direct costs)

All sales taxes and financing fees are excluded from the estimate.

Project Contingency



intended to cover changes in the general project scope nor major shifts in market conditions that could

result in significant increases in contractor margins, major shortages of qualified labor, significant

increases in escalation, or major changes in the cost of money (interest rate on loans).


Costs have been included for traditional Owner’s costs (5 percent of total direct and indirect costs) such

as project support staff, additional operators, outage time, financing, permitting, etc. Owner contingency

(5 percent of total direct and indirect costs) was also included to cover potential change orders that could

occur over the project duration.


4.2.3.1 Capital Costs The estimated capital cost for the fine slot width cylindrical wedgewire screens ranged from $16.5 to

$35.8 million (Table 4-6). All costs are provided in 2017 dollars. A conceptual design was prepared for

the 2-mm screen estimate and was used as a base to build up costs for the 1-mm and 0.5-mm options.

This cost represents an indicative screening level cost estimate, with minimal engineering effort to

develop the project design basis, and this cost should not be used for budget planning purposes.

Table 4-6: Estimated Project Costs for Fine Mesh Cylindrical Wedgewire Screens

Item Description Cost (2017 Dollars)

0.5-mm 1-mm 2-mm Total Direct Cost $21,760,000 $14,400,000 $10,010,000

Equipment cost $10,270,000 $6,540,000 $4,470,000 Installation costs and balance of plant modifications $11,490,000 $7,860,000 $5,540,000

Total Indirect Cost $4,788,000 $3,168,000 $2,203,000 Total Direct and Indirect Costs $26,548,000 $17,568,000 $12,213,000



Item Description Cost (2017 Dollars)

0.5-mm 1-mm 2-mm Contingency (25%) $6,640,000 $4,400,000 $3,060,000 Owner Cost (5%) $1,330,000 $880,000 $620,000 Owner Contingency (5%) $1,330,000 $880,000 $620,000 Total Project Cost $35,848,000 $23,728,000 $16,513,000

4.2.3.2 Operation and Maintenance Costs O&M costs will vary for each mesh size based on the debris loading and other site-specific conditions.

Annual O&M costs for routine maintenance (including annual diver inspections) were estimated to be as

follows assuming one screen replacement every five years and 0.25 percent of the equipment costs for

routine maintenance. O&M costs are estimated to range from $170,000 to $210,000 (Table 4-7).

Table 4-7: Estimated O&M for Fine Mesh Cylindrical Wedgewire Screen

Item Description Cost (2017 dollars)

0.5-mm 1-mm 2-mm Annual O&M $210,000 $190,000 $170,000

4.2.3.3 Net Present Value Costs The overall life-cycle (NPV) project costs is estimated to range from $15.9 to $32.6 million (Table 4-8).

NPV costs were estimated based on 7 percent rate of return, a 20-year operation life cycle (after project

completion), 3 percent escalation for capital, and 3 percent escalation for O&M. For the purposes of this

estimate, it was assumed the work can occur during a 3-week outage, and therefore outage revenue losses

are included in the NPV cost. The NPV cost is based on capital expenditures occurring in 2020 and

operation after project completion starting in 2020.

Table 4-8: Total Project Life Cycle Costs for Fine Mesh Cylindrical Wedgewire Screens

Item Description Cost (2017 dollars)

0.5-mm 1-mm 2-mm Net present value (NPV) 32,590,000 22,190,000 15,840,000

4.2.4 Social Costs Social costs were estimated for the installation and operation of fine mesh cylindrical wedgewire screens

at AWPP. The social costs include the expected balance sheet cash reserve decrease, the additional,

system-level fuel costs that would be incurred, and the permitting costs. Capital, O&M, and fuel costs



were treated as pre-tax, and total social costs were estimated as the NPV over the time period using

discount rates of 3 and 7 percent.

The estimated total social costs for the installation and operation of fine mesh cylindrical wedgewire

screens at AWPP range from $8.7 to $27.4 million depending on the wedgewire slot size as well as the

discount rate used (Table 4-9). Appendix B provides the detailed methods and results of the social costs

study at AWPP.



Table 4-9: Total Compliance and Social Costs for Fine Mesh Cylindrical Wedgewire Screens

Discount Rate

Screen Mesh Size

Design, Construction, &

Installation Costsa,b

O&M Costsb

Balance Sheet Cash

Reserve Decreasea

Fuel Costsb

Permitting Costsb

Total Social Costsa,b

Annualized Social Costsb

3% 0.5-mm $35.8M $210,000 $27.8M $191,000 $35,000 $27.4M $1.4M 1.0-mm $23.7M $190,000 $19.1M $191,000 $35,000 $18.9M $945,000 2.0-mm $16.5M $170,000 $13.8M $191,000 $35,000 $13.7M $685,000

7% 0.5-mm $35.8M $210,000 $17.6M $191,000 $35,000 $17.4M $871,000 1.0-mm $23.7M $190,000 $12.1M $191,000 $35,000 $8.9M $444,000 2.0-mm $16.5M $170,000 $8.7M $191,000 $35,000 $8.7M $435,000

(a) M = million (b) The engineering, permitting, and fuel costs are undiscounted and in 2017 dollars. The social costs are discounted at 3 and 7 percent.

Technical Feasibility and Cost Study Final Water Reuse and Alternate Sources of Cooling Water


5.0 WATER REUSE AND ALTERNATE SOURCES OF COOLING WATER

The following provides a comprehensive technical feasibility study and cost evaluations of water reuse

and alternate sources of cooling water.



5.1.1 Description of the Operational Measure Water resource and alternate sources for cooling water were evaluated in Section 2.1.3, 3.1.3, and 4.1.3.

Groundwater was identified as a potential alternate water source for makeup water to the cooling tower.

Groundwater and WWTPs were not feasible for technologies that will continue to use a once-through

cooling water system, such as fine mesh traveling screens and cylindrical wedgewire screens. Based on

the available aquifer thickness at the site and transmissive aquifer material indicated by the well logs, a

total of 150 vertical wells (producing 3,000 gpm each), or 39 HCWs (producing 15 MGD each) could

yield the required design intake flow requirements of 576 MGD and require approximately 9.5 miles of

riverbank for the HCWs and 14.5 miles of riverbank for the vertical wells. Given the number of wells

required, negative impacts on surrounding wells and in the aquifer, need for property acquisition or

easements, and the number of environmental clearances and road/utility permits and agreements that

would need to be obtained, the use of wells as an alternate water source for the screening systems that

would continue to use once-through cooling would be excessively expensive to implement, and is


WWTPs near AWPP do not provide sufficient quantity for once-through cooling. The amount of flow

reduction using the closest WWTP (Newburgh WWTP (4.6 MGD)) would be 0.8 percent. This very low

percentage does not warrant the use of this water source, and is considered infeasible.

5.1.2 Discussion of Land Availability Land availability to utilize other available water resources is dependent upon the distance between the

facility to the source, the characteristics and land use in which the supply and return lines are routed, and

the density of existing underground and above-grade utilities. The use of groundwater or WWTPs for a

once through cooling system is impractical and expensive, given required area of 9.5 to 14.5 miles of

riverbank. The use of groundwater or WWTPs for a once through cooling system is impractical and

expensive given the relatively small volume of water that could be used for cooling purposes.

Technical Feasibility and Cost Study Final Water Reuse and Alternate Sources of Cooling Water


5.1.3 Discussion of Other Available Water Sources Other available water sources in the vicinity of AWPP were discussed in Sections 2.1.3, 3.1.3, and 4.1.3.

5.1.4 Factors That Make the Technology Impractical or Infeasible Factors that make water reuse and alternate sources of cooling water impractical or infeasible were

discussed in Sections 2.1.3, 3.1.3, and 4.1.3. Groundwater was identified as a potential alternate water

source for makeup water to the cooling tower. Groundwater and WWTPs were not feasible for

technologies that will continue to use a once-through cooling water system, such as fine mesh traveling

screens and cylindrical wedgewire screens.

5.2 Cost Evaluations Compliance costs and social costs were not prepared since this operational measure was considered

infeasible.

Technical Feasibility and Cost Study Final Summary


6.0 SUMMARY

Per the Final Rule requirements, the technical feasibility of CCRS, fine mesh screens with a mesh size of

2 mm or smaller, and water reuse or alternate sources of cooling water were evaluated at AWPP.

Mechanical draft cooling towers, fine mesh traveling screens, fine mesh cylindrical wedgewire screens,

and the use of groundwater for cooling tower makeup are technically feasible at AWPP from a purely

engineering design standpoint.

Based on efficiency, economics, and environmental factors, a mechanical-draft evaporative cooling tower

would be the most promising alternative for retrofitting a once-through cooling facility to closed-cycle

cooling at AWPP. The preliminary concept for a mechanical draft cooling tower retrofit at AWPP would

include the installation of two new, back-to-back cooling towers, one with 12 cells and the other with 16

cells. The proposed cooling towers would be located northwest of the power plants, on top of existing

landfills (Figure 2-1; Appendix A). Based on preliminary analysis, the use of groundwater as an alternate

water source to provide makeup water to the mechanical draft cooling towers is feasible. Site-specific

engineering considerations and factors associated with locating cooling towers at AWPP are: the

significant distance between the proposed cooling tower location and the plant; surface material from the

landfills would have to be removed and backfilled; finding a suitable location for the required quantity of

landfill material; the condensers must be upgraded; and the circulating water pipe must be replaced or

repaired with a lining/wrap system. All of these factors make the CCRS retrofit challenging and

expensive at AWPP. While the overall effectiveness in reducing entrainment is expected to be

approximately 95 percent, the overall life cycle (NPV) project costs were estimated to be $290.6 million

in 2017 dollars (Table 2-6). The social costs were estimated to range from $166.9 to $273.0 million in

2017 dollars, depending upon the discount rate used (Table 2-7).

Fine mesh modified traveling screens (0.5, 1.0, and 2.0 mm) with a fish handling and return system were

also evaluated at AWPP. Intake flow velocity, head loss, and biological effectiveness were primary

factors discussed that influence the feasibility or the ease/difficulty of implementing and operating fine

mesh modified traveling screens. While head loss does not appear to be problematic, the fine mesh

screens would increase the through-screen velocity as compared to the existing screens and is higher than

the 0.5 fps criterion, ranging from 1.1 fps for 2-mm screens to 1.7 fps for 0.5-mm screens at 25 percent

clogging. The most concerning factor using fine mesh traveling screens is that the biological effectiveness

of safely returning the now impinged eggs and larvae is uncertain. The mesh size that would be most

effective in physically excluding the species most susceptible to entrainment at AWPP (freshwater drum

and gizzard shad) would be 0.5-mm mesh, followed by 1.0 and 2.0-mm mesh. However, several studies



evaluating the use of fine mesh demonstrate considerable variability in survival, depending upon species,

especially with the earliest life stages, and relatively poor survival for early life stages because they are

extremely fragile and, therefore, more sensitive to impingement stresses. An evaluation of fine mesh

traveling screens was completed by EPRI showed the 48-hour post-collection survival of the larvae

converted to impingement off the 0.5 and 1.0-mm fine mesh screens was extremely poor (generally less

than 30 percent regardless of screen type and the 48-hour post-collection survival of the larvae converted

to impingement off the 2.0-mm ranged from 0 to approximately 60 percent when larval length was less

than 12.0 mm and exceeded 90 percent when size exceeded approximately 12.0 mm. Based on a site-

specific evaluation, the overall effectiveness (reduction in EM) of the 0.5, 1.0, and 2.0-mm fine mesh

traveling screens at AWPP is estimated to be 50, 25, and 20 percent, respectively. The actual mesh size

used would need to be evaluated further if this technology is selected. The overall life cycle (NPV)

project costs were estimated to be $10.4 million in 2017 dollars (Table 3-4). The social costs were

estimated to range from $6.2 to $9.7 million in 2017 dollars, depending upon the discount rate used

(Table 3-5).

Fine mesh cylindrical wedgewire screens with a slot width of 0.5, 1.0, and 2.0 mm were evaluated at

AWPP. Based on the intake rate and available water depth at AWPP, the use of 96-inch diameter screens

is recommended. The number of screens required to have a maximum through-screen velocity of 0.5 fps

was nine for 2.0-mm slot width, 13 for 1.0-mm slot width, and 20 for 0.5-mm slot width. Site-specific

engineering considerations and factors associated with cylindrical wedgewire screens at AWPP are:

navigational hazards to commercial and recreational boating, screen damage from commercial vessels and

debris would require screen replacement at unknown intervals, significant permitting difficulties would

need to be overcome, and debris loading and biofouling would clog screens and increase slot velocity, and

IM. It is likely that only the 2.0-mm slot width would potentially be feasible because the other mesh sizes

would require too large of a footprint in the Ohio River, encroach on the navigation channel and interfere

with commercial boating, and would likely not be permitted by the USACE. If 2.0-mm wedgewire

screens are selected for further consideration at AWPP, APGI will need to contact the USACE and U.S.

Coast Guard to discuss the feasibility of permitting this installation. In addition to the engineering

constraints, the biological effectiveness of 2.0-mm mesh at a design through-screen velocity of 0.5 fps at

AWPP is uncertain. Based on morphometric data collected as part of the 2-year Entrainment

Characterization Study (not accounting for hydraulic mechanisms of cylindrical wedgewire screens), the

2-mm mesh would not physically exclude freshwater drum eggs and freshwater drum larvae less than 17

mm in length (Figure 3-3), and carpsucker/buffalo and herring larvae less than 12-mm in length (Figure

3-5; Figure 3-5). However, data on 2-0-mm fine mesh cylindrical wedgewire screens indicate egg



entrainment reductions from 67 to 92 percent and larval entrainment reductions from 62 to 84 percent (see

Table 4-2). Given the size of the fish eggs and larvae at AWPP, entrainment reductions using 2.0-mm fine

mesh screens is anticipated to be on the lower side of these ranges (67 percent for eggs and 64 percent for

larvae). Using these reductions, the overall entrainment reduction at AWPP using 2.0-mm fine mesh

cylindrical wedgewire screens is 65 percent. The overall life cycle (NPV) project costs were estimated to

range from $15.9 to $32.6 million in 2017 dollars (Table 4-8). The social costs were estimated to range

from $8.7 to $27.4 million in 2017 dollars, depending upon wedgewire slot size and the discount rate

used (Table 4-9).

Water resource and alternate sources for cooling water, including groundwater wells, and wastewater

were evaluated at AWPP. Groundwater was identified as a potential alternate water source for makeup

water to the cooling tower. Groundwater and WWTPs were not feasible for technologies that will

continue to use a once-through cooling water system, such as fine mesh traveling screens and cylindrical

wedgewire screens. Based on the available aquifer thickness at the site and transmissive aquifer material

indicated by the well logs, a total of 150 vertical wells (producing 3,000 gpm each), or 39 HCWs

(producing 15 MGD each) could yield the required design intake flow requirements of 576 MGD and

require approximately 9.5 miles of riverbank for the HCWs and 14.5 miles of riverbank for the vertical

wells. Given the number of wells required, negative impacts on surrounding wells and in the aquifer, need

for property acquisition or easements, and the number of environmental clearances and road/utility

permits and agreements that would need to be obtained, the use of wells as an alternate water source for

the screening systems that would continue to use once-through cooling would be excessively expensive to

implement, and is considered infeasible. Based on the analysis of available water sources, WWTPs near

AWPP do not provide sufficient quantity for once-through cooling. The amount of flow reduction using

the closest WWTP (Newburgh WWTP (4.6 MGD)) would be 0.8 percent. This very low percentage does

not warrant the use of this water source. Given these factors, compliance and social costs were not

prepared for water reuse and alternate sources for cooling water.

Technical Feasibility and Cost Study Final Literature Cited


7.0 LITERATURE CITED

Beak Consultants, Inc. (2000a). Post-Impingement Fish Survival Dunkirk Steam Station, Winter, Spring, Summer, and Fall 1998–1999. Prepared for NRG Dunkirk Power LLC.

Beak Consultants, Inc. (2000b). Post-Impingement Fish Survival at Huntley Steam Station, Winter and Fall 1999. Final Report. Prepared for Niagara Mohawk Power Corporation.

Browne, M.E., L.B. Glover, D.W. Moore, and D.W. Ballengee. (1981, April 22-24). In-Situ Biological and Engineering Evaluation of Fine Mesh Profile-Wire Cylinders at Powerplant Intake Screens. In P.B. Dorn and Johnson (Eds.), Advanced Intake Technology for Power Plant Cooling Water Systems (pg. 36-46). Proceedings of the Workshop of Advanced Intake Technology held at the Sheraton-Harbor Island Hotel San Diego, California, April 22-24.

Brueggemeyer, V. D., D. Cowdrick, and K. Durell. (1988). Full-Scale Operational Demonstration of Fine-Mesh Screens at Power Plant Intakes. In Fish Protection at Steam and Hydroelectric Power Plants, San Francisco, California, October 28–31, 1987. Sponsored by Electric Power Research Institute (EPRI). CS/EA/AP-5663-SR.

Carolina Power & Light Company. (1985a). Brunswick Steam Electric Plant 1984 Biological Monitoring Report. Biology Unit Environmental Services Section.

Carolina Power & Light Company. (1985b). Brunswick Steam Electric Plant Cape Fear Studies Interpretive Report. Biology Unit Environmental Services Section.

Electric Power Research Institute (EPRI). (2005). Field Evaluation of Wedge Wire Screens for Protecting Early Life Stages of Fish at Cooling Water Intakes. Technical Report 1010112. Palo Alto, California: EPRI.

Electric Power Research Institute (EPRI). (2006a). Laboratory Evaluation of Modified Ristroph Traveling Screens for Protecting Fish at Cooling Water Intakes. Technical Report 1013238. Palo Alto, CA: EPRI.

Electric Power Research Institute (EPRI). (2006b). Field Evaluation of Wedge Wire Screens for Protecting Early Life Stages of Fish at Cooling Water Intake Structures, Chesapeake Bay Studies. EPRI Report Summary for EPRI Report 1012542. Section 316(a) and 316(b) Fish Protection Issues Program. Palo Alto, CA: EPRI.

Electric Power Research Institute (EPRI). (2009). Laboratory Evaluation of Fine-mesh Traveling Water Screens for Protecting Early Life Stages of Fish at Cooling Water Intakes: Research Progress Update Through 2008. Technical Report 1015578. Palo Alto, CA: EPRI.

Electric Power Research Institute (EPRI). (2010). Laboratory Evaluation of Fine-mesh Traveling Water Screens. Technical Report 1019027. Palo Alto, CA: EPRI.

Electric Power Research Institute (EPRI). (2011a). Net Environmental and Social Effects of Retrofitting Power Plants with Once-through Cooling to Closed-cycle Cooling. Technical Report 1022760. Palo Alto, CA: EPRI.

Electric Power Research Institute (EPRI). (2011b). Closed-Cycle Cooling System Retrofit Study. Capital and Performance Cost Estimates. Technical Report 1022491. Palo Alto, CA: EPRI.



Electric Power Research Institute (EPRI). (2012). Fish Protection at Cooling Water Intake Structures: A Technical Reference Manual – 2012 Update. Technical Report 3002000231. Palo Alto, CA: EPRI.

Electric Power Research Institute (EPRI). (2015). Design of Fish Return Systems and Operations/Maintenance Guidelines. Technical Report 3002001422. Palo Alto, CA: EPRI.

Hanson, B. N. (1981). Studies of Larval Striped Bass (Morone saxatilis) and Yellow Perch (Perca flavescens) Exposed to a 1 mm Slot Profile-Wire Screen Model Intake. In P. B. Dorn and J. T. Larson (Eds.), Proceedings of the Workshop on Advanced Intake Technology. San Diego, California.

Hanson, B.N., W.H. Bason, B.E. Beiz, and K.E. Charles. (1977). A Practical Intake Screen which Substantially Reduces Entrainment. Fourth Nation Workshop on Entrainment and Impingement. Chicago, Illinois. Sponsored by Ecological Analysts, Inc.

Henderson, P.A., R. M. H. Seaby, and J. R. Somes. (2003). A Comparison of Ecological Impacts of Power Plant Once-Through, Evaporative and Dry Cooling Systems on Fish Impingement and Entrainment. Pisces Conservation Ltd.

Kuhl, G. H. and K. N. Mueller. (1988). Prairie Island Nuclear Generating Plant Environmental Monitoring Program 1988 Annual Report Fine Mesh Vertical Traveling Screens Impingement Survival Study. Northern States Power Company.

Lifton, W.S. (1979). Biological Aspects of Screen Testing on the St. Johns River, Palatka, Florida. In Passive Screen Intake Workshop. St. Paul, MN: Johnson Division UOP Inc.

McLaren, J. B. and L. R. Tuttle Jr. (2000). Fish Survival on Fine Mesh Traveling Screens. Environmental Science and Policy 3: S369-S374.

Otto, R.G., T.I. Hiebert, and V.R. Kranz. (1981). The Effectiveness of a Remote Profile-Wire Screen Intake Module in Reducing the Entrainment of Fish Eggs and Larvae. In P. B. Dorn and J. T. Larson (Eds.), Proceedings of the Workshop on Advanced Intake Technology. San Diego, California.

SPX Cooling Technologies, Inc. (2009). Cooling Tower Fundamentals. Second Edition. Overland Park, Kansas, USA.

Taft, E. P., T. J. Horst, and J. K. Downing. (1981). Biological Evaluation of a Fine-Mesh Traveling Screen for Protecting Organisms. In Workshop on Advanced Intake Technology, San Diego, California, April 22–24.

Tenera Environmental. (2013). Length-Specific Probabilities of Screen Entrainment of Larval Fishes Based on Head Capsule Measurements. In Support of the California State Water Resources Control Board Once-Through Cooling Policy Nuclear-Fueled Power Plant (NFPP) Special Studies.

Thompson, T. (2000). Intake Modifications to Reduce Entrainment and Impingement at Carolina Power and Light Company’s Brunswick Steam Electric Plant, Southport, North Carolina. Environmental Science and Policy, 3, S417-S424.



U.S. Environmental Protection Agency (EPA). (2004). Technical Development Document for the Final Section 316(b) Phase II Existing Facilities Rule. Office of Water. EPA 821-R-04-007.

U.S. Environmental Protection Agency (EPA). (2014a). National Pollutant Discharge Elimination System—Final Regulations to Establish Requirements for Cooling Water Intake Structures at Existing Facilities and Amend Requirements at Phase I Facilities; Final Rule. 40 CFR Parts 122 and 125. August 15, 2014. EPA–HQ–OW–2008–0667, FRL–9817–3.

U.S. Environmental Protection Agency (EPA). (2014b). Technical Development Document for the Final Section 316(b) Existing Facilities Rule. Office of Water. EPA-821-R-14-002. May.

Weisberg, S.B., W.H. Burton, F. Jacobs, and E.A. Ross. (1987). Reductions in Ichthyoplankton Entrainment with Fine Mesh, Wedge Wire Screens. North American Journal of Fisheries Management, 7, 386-393.

Zeitoun, I.H., J.A. Gulvas, J.Z. Reynolds. (1981). Effectiveness of Small Mesh Cylindrical Wedge Wire Screens in Reducing Fish Larvae Entrainment at an Offshore and an Onshore Location of Lake Michigan. In: P.B. Dorn and Johnson (eds.), Advanced Intake Technology for Power Plant Cooling Water Systems (pg. 57-64). Proceedings of the Workshop of Advanced Intake Technology held at the Sheraton-Harbor Island Hotel San Diego, California. April 22-24.

- COOLING TOWER SKETCH

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EXISTING LANDFILL

- SOCIAL COST STUDY

Social Costs of Purchasing and Installing Entrainment Reduction Technologies: Alcoa Warrick Power Plant Prepared for: Alcoa Corporation Prepared by: Veritas Economics January 2018

Office: 919.677.8787 Economic Consulting Fax: 919.677.8331 VeritasEconomics.com

Veritas1851 Evans RoadCary, NC 27513

Social Costs Study: Alcoa Warrick January 2018

i Economic Consulting

Veritas

Table of Contents

Section Page

1. The Social Costs of Purchasing and Installing Technologies ........................... 1

1.2 Financial and Regulatory Environment......................... Error! Bookmark not defined. 1.3 Market Environment .................................................................................................... 8 1.4 Social Costs of Compliance ........................................................................................ 8

2. References ........................................................................................................... 12

Appendix A Power System and Off-Site Emissions Study for Alcoa Warrick Power Plant ...................................................................................................................... 14

Power System Overview .................................................... Error! Bookmark not defined.

Social Cost Study: Alcoa Warrick January 2018

1 Economic Consulting

Veritas

1. The Social Costs of Purchasing and Installing Technologies Reducing entrainment can generally be accomplished by altering operations; closing the

facility; or by purchasing, installing, and operating entrainment reduction technologies. These

activities lead to a number of physical changes and financial effects that can produce social costs.

The Environmental Protection Agency (EPA) defines social costs as the “opportunity cost to

society of employing scarce resources to prevent the environmental damage otherwise occurring

except for the design and operation of compliance technology” (79 Fed. Reg. 158, 48387). These

are further delineated as each of the following:

• Real-Resource Compliance Costs—direct purchase, installation, and operation

• Government Regulatory Costs—monitoring, administration, and enforcement

• Environmental Externalities—increased fuel cost impacts from energy penalty and proposed outages and property value, recreation, human health, and increased water consumption impacts.

This report covers each of these social cost categories. Real-Resource Compliance Costs result

from purchasing and installing technologies at the Alcoa Warrick Power Plant (AWPP).

Government Regulatory Costs are developed from EPA’s estimates in the national rule (79 Fed.

Reg. 158, 48300–48439). The social costs of environmental externalities are developed from the

Power System Capacity Loss and Offsite Emissions Study. Appendix A presents the methods

and results of this evaluation.

Figure 1 depicts how expenditures on entrainment reduction technologies would have

implications for Alcoa Corporation’s (Alcoa) balance sheet and construction activities. As the

figure depicts, construction generates nearby economic activity, which can lead to good social

outcomes such as more jobs. These economic impacts can be studied via economic input-output

analysis techniques. As related local outcomes are typically considered good, they are not

measured under social costs and not considered further here.



Veritas

Figure 1: Social Costs Associated with Technology Expenditures

Balance sheet implications are transmitted through financial, electricity, and regulatory

markets to register as social costs to shareholders, ratepayers, and the general population. How

these are realized as social costs depends upon the regulatory and market environments.

1.1 Entrainment Reduction Technology Options The Alcoa Warrick Power Plant (AWPP) is a coal-fueled, steam-electric generating station

located on the Ohio River in Newburgh, Indiana approximately 13 miles southeast of Evansville,

Indiana. Operational since the early 1960’s, Units 1, 2, 3, and 4 collectively produce 750MW of

electricity primarily for the Alcoa Warrick Operations manufacturing facility. The generating

station also provides potable water, steam, and high temperature water for the manufacturing

facility. Unit 4 is co-owned by Vectren Energy Delivery of Indiana – South (Vectren South), an

electric and natural gas utility subsidiary of Vectren Corporation (Vectren). Vectren South

operates in Indiana and west central Ohio.

The current, once-through cooling water system at AWPP has a total daily intake flow

(DIF) of 576 million gallons per day (MGD) with an actual intake flow (AIF) of 518 MGD and 91%

of the withdrawn water is used for cooling purposes. Burns & McDonnell have considered several

alternative screen, water reuse, and closed-cycle cooling technologies (Burns and McDonnell

2017) and have evaluated the following options for AWPP:

Veritas-0117

Technology Expenditures

Balance Sheet Implications

Construction Activities

Nearby Jobs, Taxes

Shareholders

RatepayersElectricity Market

Physical Change System Effects Social Cost Categories (r)(10)

Economic Impacts (Jobs, Taxes)

(r)(10)(iii)Compliance Cost

(r)(10)(iii)



Veritas

• Closed-cycle cooling tower

• Fine mesh traveling screens (FMS) with 0.5mm, 1.0mm, and 2.0mm mesh size

• Cylindrical wedge wire screens with 0.5mm, 1.0mm, and 2.0mm mesh sizes

Table 1 summarizes the estimated capital costs for each technology.

Table 1 Capital Cost Estimates for Feasible Alternatives at AWPP

Technology Capital Cost

Estimate Closed-cycle cooling $246.6M

Fine mesh traveling screens – 2.0, 1.0, and 0.5mm mesh sizea $9.0M

Wedge wire screens 0.5mm mesh size $35.8M Wedge wire screens 1.0mm mesh size $23.7M

Wedge wire screens 2.0mm mesh size $16.5M a The capital and operation and maintenance costs are the same for 2.0, 1.0, and 0.5mm fine mesh

traveling screens.

Balance sheet implications would accompany the purchase, installation and operation of

any of these entrainment reduction technologies. Costs vary from lower cost fine mesh traveling

screen technology options to higher cost closed-cycle cooling retrofit options. Detailed costs of

the feasible options are presented in Section 1.4 of this report.

1.2 Financial and Regulatory Environment AWPP is operated by Alcoa Power Generating Incorporated (APGI), a division of Alcoa.

Headquartered in Pittsburgh, Pennsylvania. Alcoa is a global aluminum company comprised of

bauxite mining, alumina refining, aluminum production (smelting, casting and rolling), and energy

generation (Alcoa 2017a). With 14,000 employees in ten countries, Alcoa is the world’s 6th largest

aluminum producer and the world’s largest bauxite miner and refiner of alumina (Alcoa 2016b).

Products include primary aluminum, sheet aluminum, and rolled aluminum. In addition, electricity

is generated for use during the manufacturing process with excess capacity sold into the

competitive open market. The production of aluminum is an energy intensive process requiring

between 13MW and 17MW of electricity for one metric ton (MT) of aluminum output. Alcoa’s eight

worldwide energy facilities have a combined capacity of 1,685MW. This meets the electricity

needs of approximately 14% of smelter operations with the remainder being supplied through

long-term power contracts (Alcoa 2016b).

AWPP uses cooling water for both industrial processes and on-site power generation

through the operation of 4 coal-fired generators with a combined generating capacity of 750MW.

Units 1-3 and half of Unit 4 (600MW in total) produce electricity for the adjacent Alcoa Warrick



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Operations manufacturing facility. The facility currently operates a casthouse and rolling mill to

produce aluminum sheet that is used primarily in the aluminum can packaging end use market.

In March 2016, the facilities’ smelter operation was closed which resulted in approximately 36%

of Alcoa’s portion of AWPP’s electric generating capacity being sold into the open market (Alcoa

2016b). The Company plans to restart 3 of the 5 smelter pot lines in the first quarter of 2018 to

supply the rolling mill with molten metal to meet expected increases in demand for aluminum

sheet. With the smelter restarting, the amount of excess electricity sold into the open market will

be reduced.

AWPP also produces electricity to serve the needs of Vectren South’s 144,000 electric

customers in seven southwest Indiana counties. Fifty percent of the 300MW generated by AWPP

Unit 4 (150MW in total) is provided to Vectren South for use by their electric customers. With a

system generating capacity of nearly 1,300MW, the AWPP plant provides approximately 12% of

Vectren South’s total generation portfolio (Vectren 2017). Figure 2 presents the Vectren South

electric service territory and location of the AWPP and Alcoa Warrick Operations manufacturing

facility.

With respect to social costs, the cost of purchasing, installing, and operating entrainment-

reduction technologies are Real-Resource Compliance Costs. As a co-owner of Unit 4, Vectren

South will be responsible for a portion of these costs. Vectren is potentially eligible to recover all

or part of their share of the costs of installing entrainment reduction technologies at AWPP. A

traditional, rate-based electric utility generating plant is built by a regulated utility specifically to

serve that utility’s customers. Through the ratemaking process, customers are required to pay

for the plant’s construction, operation, and maintenance costs. Investors in the utility are then

allowed a fair financial return on the capital investment. Electric utilities operating in Indiana can

file a rate request with the Indiana Utility Regulatory Commission (IURC) for recovery of costs

and establishment of a fair rate of return. The IURC holds hearings and based on the facts can

approve a settlement agreement authorizing cost recovery (IURC 2017). Procedures involved in

rate request hearings include allowing intervener comments and Vectren South rebuttals. This

process, along with the permitting itself, results in costs to the government, which are Government

Regulatory Costs.



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Figure 2: Vectren South Service Territory and Generation Assets

Blackfoot Clean Energy Facility

WarrickF.B. Culley

A.B. Brown

Kentucky

Alcoa Warrick Operations

Legend Vectren South Service Territory and

Generation Assets

Vectren South Service TerritoryFuel Source

A.B. Brown Coal & Natural GasF.B. Culley CoalWarrick* CoalBlackfoot Clean Energy Facility Renewable EnergyBenton County Wind Farms Renewable Energy* Vectren owns 50% of Warrick Unit 4

Illinois Indiana

Benton County Wind Farms



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Since installing entrainment-reducing technologies is a regulatory environmental

compliance requirement (as opposed to typical operations and maintenance), these costs are

typically included in a future rate case filing and passed on to customers in the form of higher

electric rates. However, Vectren has stated their intent to exit joint operations with Alcoa at AWPP

Unit 4 in mid-2020. Vectren’s 2016 Integrated Resource Plan (Vectren 2016) outlines a twenty-

year plan to transition to an energy portfolio that includes increases in natural gas and solar

generation and decreases in coal generation. Given Vectren’s plan to discontinue co-ownership

of AWPP Unit 4 during the compliance timeframe, it is unlikely that any costs of compliance at

AWPP will be passed onto Vectren South’s electric customers. For purposes of this analysis, it

is therefore assumed that 100% of the compliance costs at AWPP will be the responsibility of

Alcoa.

With respect to social costs then, the Real-Resource Compliance Costs would have to be

passed onto Alcoa’s shareholders as an additional cost of operating AWPP. These costs could

result in lower returns for investors depending on future market conditions. Lower returns could

make Alcoa’s stock less attractive for investors which could put downward pressure on the stock

price negatively impacting Alcoa’s ability to raise capital for operations. Alcoa’s recent financial

performance is instructive with respect to the implications of increased costs on the balance sheet.

The ability to absorb these costs without significant negative financial impacts is dependent in

large part on the financial health of the overall company.

As the inventor of the creation of aluminum through electrolysis, Alcoa is a global leader

in the production of bauxite, alumina, and aluminum. The aluminum industry is a highly

competitive global industry with price and production costs critical to the success and profitability

of producers. The London Metal Exchange (LME) primary aluminum price reflects the market

price for one ton of aluminum. For every $100 per ton decline in LME aluminum price, Alcoa net

earnings decline approximately $190 million (Yahoo Finance 2015). Supply and demand is the

main driver for LME aluminum prices. Producers like Alcoa adjust manufacturing capacity

(supply) to meet market demand at the prevailing LME market price. Demand for aluminum is

highly correlated to global economic growth as demand is greatest in highly cyclical end-use

markets such as the commercial construction, transportation, automotive, and aerospace

industries. The slowdown of global economies coupled with a global oversupply resulted in weak

alumina and aluminum prices which caused parent company Alcoa Incorporated to post losses

from 2014 to 2016 (Alcoa 2016a). Significant write-downs of almost $3 billion have been taken

to idle, close, or sell manufacturing plants to reduce operating costs and excess capacity (Alcoa

2016b). In the fourth quarter of 2016, due to persistent market pressures, Alcoa Incorporated



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split into two companies: Alcoa and Arconic to streamline the organization and shore up the

balance sheet of the core aluminum business (mining/refining/smelting) retained under the Alcoa

nameplate.

Efforts to strengthen their operations and balance sheet are starting to pay off. Alcoa has

rightsized their commodity aluminum business and reduced their position on the aluminum

manufacturing cost curve from the 51st to the 38th percentile (Alcoa 2016a). At the same time,

LME aluminum prices have rebounded. After declining 43% from 2011 to 2016, prices are up

25% this year (LME 2017, Macrotrends 2017). The outlook for global demand is improving as

well. China has implemented stricter environmental policies and closed heavy polluting smelters

representing approximately 10% of their aluminum capacity which equates to 6% of global supply.

At the same time, China’s economic stimulus plan will result in additional infrastructure projects

and increased demand for aluminum. With China consuming more aluminum while producing

less, Alcoa is well positioned to meet both the increased demand by China and the global demand

they previously supplied. Alcoa increased its aluminum demand forecast by 0.25% to reflect an

improved market outlook (Alcoa 2017c, Motley Fool 2017b).

Market improvements have translated to stronger financials as Alcoa’s balance sheet has

experienced increased revenues and earnings over the first three quarters of 2017. The stock

price is up 15% through November, slightly below the S&P 500 Index performance (Morningstar

2017). In June, Alcoa’s credit rating was upgraded from “stable” to “positive” while maintaining a

BB- non-investment grade rating (S&P Global Platts 2017). While not yet large enough to pay a

dividend, cash flows have improved. After averaging $13 million in cash flow per year from 2013-

2016, Alcoa ended third quarter 2017 with $1.1 billion in cash on hand (Alcoa 2017c, Motley Fool

2017a). While still subject to volatile market forces, Alcoa expects continued financial

performance improvements in the coming years.

In addition to 316(b) compliance costs, Alcoa needs to invest in AWPP to be compliant

with EPA’s 2015 rules for effluent limitations guidelines (ELG) for water discharges and coal

combustion residuals (CCR) for operation of coal ash ponds. AWPP’s ELG and CCR non-

compliance was another factor in Vectren’s decision to terminate co-ownership of Unit 4 as

opposed to sharing in these forthcoming compliance costs (Vectren 2016). These costs will make

AWPP more expensive to run and with Vectren no longer sharing in a portion of the post-2020

operational costs, the overall operations at AWPP will become costlier over the long term.

Installing entrainment reducing technologies at AWPP to comply with EPA’s 316(b) Final

Rule represents an additional financial and operational challenge to Alcoa. The economics of

operating the plant will likely be re-evaluated with this regulatory requirement. Compliance costs



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would have to be paid out of Alcoa’s cash balance which is in the process of being built back up

after years of market pressures and financial struggles. This could put downward pressure on

the stock price which could negatively impact Alcoa’s ability to raise additional investment monies

for operations.

1.3 Market Environment AWPP currently supplies critically needed electricity to the Alcoa Warrick Operations

casthouse and rolling mill. The significance of the generating plant on Alcoa’s operations will be

even higher with the Q1 2018 planned restart of smelter operations. Any construction downtime

that takes the plant offline will effectively halt production at the smelters, casthouse, and rolling

mill and will significantly impact Alcoa’s operating profits. The ability to secure replacement power

in the open market will be critical in maintaining manufacturing operations at the facility.

AWPP is geographically located within Zone 6 of the Midcontinent Independent System

Operator (MISO) regional transmission organization. Headquartered in Carmel, Indiana, MISO

provides electric reliability and coordination services in nine geographically defined local resource

zones across fifteen states and Manitoba, Canada. Excess generation at AWPP is bid into the

MISO power market and dispatched at least cost to participating members. To maintain regional

reliability, MISO establishes planning reserve margins by zone where member utilities are

required to meet a minimum capacity reserve margin. Electric utilities are required to maintain

adequate reserve margins which would enable them to meet high demand during peak periods,

extreme weather events, planned plant outages for maintenance, inspections, refueling, and for

any unplanned outage that may occur. Given the existence of zone specific reserve margins,

Alcoa could potentially buy capacity from MISO during construction downtime for installation of

entrainment reducing technologies. However, according to the 2016 Resource Adequacy Survey

results, Zone 6 is projected to have an 800MW shortfall by 2018 at the earliest (Vectren 2016).

Consequently, the availability of replacement capacity from the MISO market is uncertain. If

capacity is available, higher cost generating units would need to be dispatched to replace the

power previously produced by AWPP. The Power System Capacity Loss and Offsite Emissions

study presented in Appendix A discusses this scenario and associated impacts in more detail.

1.4 Social Costs of Compliance The first step in estimating the social costs of compliance is to determine whether the

entrainment reducing technology costs result in the plant becoming uneconomic to operate. A

premature shutdown of the plant would have social costs related to job loss, loss of income and

expenditures, tax base loss, increased electricity costs due to generation being dispatched at a

higher price from less efficient plants, and increased infrastructure costs to maintain grid reliability.



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Alcoa’s tenuous financial standing and volatile market environment coupled with the plants’

increased costs of operation with the ELG and CCR compliance costs and expected loss of

Vectren as a contributor to the costs of operating Unit 4 present a potentially difficult future for

AWPP’s long-term viability. However, as the only electric supplier powering Alcoa Warrick’s

operations of the casthouse, rolling mill, and smelters that are set to be restarted next year, AWPP

is invaluable suggesting that only an extraordinarily expensive conversion requirement would lead

to premature closure. Therefore, this analysis specifies Alcoa will incur the entrainment reducing

compliance costs and continue to operate the Warrick plant. Table 2 summarizes the results of

this evaluation and its implication for social costs.

Following the requirements of the rule, Table 2 evaluates social costs under two discount

rates: 3 and 7 percent (79 Fed. Reg. 158, p. 48428). As the first column of Table 2 shows, the

top half of the table presents the present value of social costs discounted at 3 percent, and the

bottom half presents the social costs discounted at 7 percent. The next column of the table

presents each of the feasible technologies evaluated at AWPP. The third and fourth columns

present the engineering costs estimated for each feasible technology. The third column presents

the estimated design, construction, and installation costs, and the fourth column presents the

annual operation and maintenance (O&M) costs for each feasible technology.

The remaining columns in the table present the individual categories of social costs

developed for this analysis: balance sheet cash reserve decrease, fuel costs, externality costs,

and permitting costs. The analysis discounts the future stream of each of these social costs at

the relevant discount rate and sums them over the years they are specified to occur to develop

the Total Present Value Social Cost estimate presented in the penultimate column. The table

concludes by presenting the Annual Social Cost estimate for each technology. The annual

estimate divides the Total Social Cost by the number of years the analysis is conducted over.

Engineering costs are specified as occurring over a twenty-year time period. Fuel costs

are specified to occur during construction, based on outage impacts, and during operation, based

on efficiency and auxiliary load impacts. Regulatory documents will be submitted in 2018 and the

timing for activities related to installation are dependent on the technology being installed. Table

3 reflects the timing specifications for each of the three alternatives.

Social Costs Study: Alcoa Warrick January 2018


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Table 2 Total Engineering & Social Costs of Feasible Technology Options at AWPP

Engineeringa Social Costs

Discount Rate Technology Type

Total Design, Construction, &

Installation Costs Annual

O&M Costs

Balance Sheet Cash Reserve

Decrease Fuel

Costsa Externality

Costsb Permitting

Costsa

Total Present Value of

Social Costs

Annual Social Costs

3% Closed-cycle cooling $246.6M $6.0M $242.2M $46.6M - $75k $273.0M $13.7M

Fine mesh traveling screens 2mm, 1mm, & 0.5mmc $9.0M $250k $9.7M $191k - $15k $9.7M $484.4k

Wedge wire screens 0.5mm $35.8M $210k $27.8M $191k - $35k $27.4M $1.4M

Wedge wire screens 1mm $23.7M $190k $19.1M $191k - $35k $18.9M $945k


7% Closed-cycle cooling $246.6M $6.0M $148.1M $46.6M - $75k $166.9M $8.3M

Fine mesh traveling screens 2mm, 1mm, & 0.5mmc $9.0M $250k $6.1M $191k - $15k $6.2M $308k

Wedge wire screens 0.5mm $35.8M $210k $17.6M $191k - $35k $17.4M $871k



a The engineering, fuel, and permitting costs are undiscounted and in 2017 dollars. The social costs associated with each technology are discounted at 3 and 7 percent using the specifications outlined in Table 3.

b Externality costs include decreases in social wellbeing resulting from property value, recreation, human health, reliability, and water consumption impacts. These categories of social costs were beyond the scope of this analysis and are not quantified in this evaluation.

c The capital and operation and maintenance costs are the same for 2, 1, and 0.5mm fine mesh traveling screens, so we present them together on one row.



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Table 3 Timing Specified for Feasible Technologies at AWPP

Entrainment Reducing Technology

Regulatory Documents Submitted

Permitting, Design,

Construction & Installation

O&M Costs Begin

Years of Operation

Closed-cycle cooling 2018 2018-2021 2022 20 Fine mesh traveling screens 0.5mm, 1.0mm, or 2.0mm

2018 2018-2020 2021 20

Wedge Wire Screens 0.5mm, 1.0mm, or 2.0mm

2018 2018-2020 2021 20

The social costs of each technology include the expected balance sheet cash reserve

decrease associated with each technology, the additional, system-level fuel costs that would be

incurred with each technology, and the permitting costs. As previously noted, the analysis

specifies that all the engineering costs are paid for with Alcoa’s cash reserves. To develop the

cash reserve decrease, the design, construction, and installation costs are allocated over the

specified construction and installation time period presented in Table 3. Operation and

maintenance costs are then added for each year the technology is operational, and the future

stream of those costs are discounted by 3 and 7 percent to develop the present value estimate

for each discount rate.

Fuel costs represent the additional power needed to operate the new technologies and

the additional fuel needed from running less efficient units during installation construction outages.

The fuel costs are developed from evaluating backpressure and auxiliary load effects, capacity

losses from each of the technologies with estimated outage times, and electricity consumption

associated with each technology. Details of the fuel cost estimates are presented in Appendix A.

Permitting costs include the total costs associated with permitting, monitoring,

administering, and enforcing the technology selection and installation. Costs are incurred by the

government as the permitting and review process is undertaken. These vary with the type of

technology, as certain technologies require substantially more permitting. Those with more

significant environmental effects would have higher permitting costs. These costs are initially

borne by the government, but ultimately paid by taxpayers. Permitting costs are developed from

EPA’s estimates in the national rule (79 Fed. Reg. 158, 48300-48439) and are specified to be 2%

of direct capital costs.



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2. References Burns and McDonnell. 2017. Cost Estimates for Alcoa Warrick Power Plant.

Alcoa. 2016a. “Annual Report for 2016”. March 17, 2017. Available at http://investors.alcoa.com/financial-reports/annual-reports-and-proxy-information. Retrieved on October 31, 2017.

Alcoa. 2016b. “Form 10-K Report for the Fiscal Year Ended December 31, 2016. Available at https://www.sec.gov/Archives/edgar/data/4281/000119312517062657/d293282d10k.htm. Retrieved on October 31, 2017.

Alcoa. 2017a. “Company Website. Available at https://www.alcoa.com/global/en/home.asp. Retrieved on October 31, 2017.

Alcoa. 2017b. “Alcoa Corporation Plans Partial Restart of Aluminum Smelter at Warrick Operations”. July 11, 2017. Available at http://investors.alcoa.com/news-releases/2017/07-11-2017-210502599. Retrieved on November 14, 207.

Alcoa. 2017c. “Alcoa Corporation Reports Third Quarter 2017 Results”. October 18, 2017. Available at http://investors.alcoa.com/news-releases/2017/10-18-2017-210950457. Retrieved on November 14, 2017.

IURC. 2017. “About the IURC”. Available at http://www.in.gov/iurc/2451.htm. Retrieved on November 16, 2017.

LME. 2017. “LME Aluminum”. Available at https://www.lme.com/Metals/Non-ferrous/Aluminium#tabIndex=0. Retrieved on November 9, 2017.

Macrotrends. 2017. “Aluminum Prices Interactive Historical Chart”. Available at http://www.macrotrends.net/2539/aluminum-prices-historical-chart-data. Retrieved on November 14, 2017.

Morningstar. 2017. “Alcoa Corp. AA”. Available at http://www.morningstar.com/stocks/XNYS/AA/quote.html. Retrieved on November 11, 2017.

Motley Fool. 2017a. “Alcoa Stock Upgraded: What You Need to Know”. January 25, 2017. Available at https://www.fool.com/investing/2017/01/25/alcoa-stock-upgraded-3-things-you-need-to-know.aspx. Retrieved on November 14, 2017.

Motley Fool. 2017b. “Here’s Why Alcoa Gained 20.6% in August”. September 8, 2017. Available at https://www.fool.com/investing/2017/09/08/heres-why-alcoa-gained-206-in-august.aspx. Retrieved on November 14, 2017.

S&P Global Platts. 2017. “S&P Upgrades Alcoa’s Rating Outlook on Margins Boost”. June 21, 2017. Available at https://www.platts.com/latest-news/metals/sydney/sampp-upgrades-alcoas-rating-outlook-on-margins-26756742. Retrieved on November 16, 2017.

Vectren. 2016. “2016 Integrated Resource Plan”. December 2016. Available at https://www.vectren.com/assets/downloads/planning/irp/IRP-2016-vol1.pdf. Retrieved on November 16, 2017.



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Vectren. 2017. “About Vectren Corporation”. Available at https://www.vectren.com/assets/downloads/corporate/vectren-factsheet.pdf. Retrieved on November 14, 2017.

Yahoo Finance. 2015. “LME Aluminum is Trading at 17-month Low on Weak Macros”. June 19, 2015. Available at https://finance.yahoo.com/news/lme-aluminum-trading-17-month-132136854.html. Retrieved on November 9, 2017.



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Appendix A Power System and Off-Site Emissions Study for Alcoa Warrick

Power Plant

Hourly Energy Penalty, Power System Capacity Loss and Off-Site Emissions Study for Alcoa Warrick Power Plant FINAL Prepared for: Alcoa Prepared by: Veritas Economics January 2018

Office: 919.677.8787 FINAL Economic Consulting Fax: 919.677.8331 VeritasEconomics.com

Veritas1851 Evans RoadCary, NC 27513

Power System and Off-Site Emissions Study: Warrick January 2018

FINAL 16 Economic Consulting

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Table of Contents

Section Page

Power System Outage, Equipment Load, and Backpressure ................................. 19

Outages ............................................................................................................................ 19 Backpressure and Equipment Load .................................................................................. 20 Power System ................................................................................................................... 22 Power System Simulation ................................................................................................. 24

Quantitative Evaluation .............................................................................................. 26

Estimate Hourly Energy Penalty ........................................................................................ 26 Energy Penalty Study Approach ............................................................................... 27 Step 1—Source Water and Wet Bulb Data ............................................................... 31 Step 2—Calculate Cooling Tower Circulating Temperatures ..................................... 33 Step 3—Calculate Cooling Tower Circulating Temps ................................................ 33 Step 4—Estimate the Water Temperature to Heat Rate Curve ................................. 34 Step 5—Determine Efficiency/Capacity Impacts ....................................................... 35

Specify Hourly Load for Upper Midwest ............................................................................ 36 Operate Model Under Baseline Conditions ....................................................................... 36 Create Scenarios Representing Warrick Conversion and Ongoing Operations ................. 38 Run Simulations to Create Counterfactual Dispatch .......................................................... 38 Calculate Net Differences in Fuel Consumption, Costs, and Emissions ............................ 39

References ................................................................................................................... 41



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Power System Outage, Equipment Load, and Backpressure Many important physical and economic effects of reducing entrainment are transmitted

through the power system. These arise from outages for technology installation, electricity

consumption, and generation efficiency changes from cooling water temperature differentials.

This report studies these effects to develop information for (r)(10), (r)(12), and the 125.98(f) Must

and May factors.

Outages Extended outage times during technology installation are effectively temporary capacity

reductions. As depicted in Figure 1, these construction outages lead to system-level efficiency

and capacity changes. Significant capacity reductions can affect system reliability, which can

have social costs. Electrical system reliability effects are a factor that Directors may consider in

determinations (May 4—Reliability Impacts). These effects are unlikely with planned outages and

are not evaluated in this study.

Figure 1: Effects of Construction Outage Time

Outages always lead to less efficient dispatch and changes in energy consumption. These

are to be assessed under (r)(12)(i)—Energy Consumption. Changes in energy consumption will

impact electricity production costs, leading to social costs that must be quantified in (r)(10)(iii)—

Outages Other. Also, the re-dispatch associated with system-level efficiency changes leads to

stack emissions changes which are to be studied under (r)(12)(ii)—Emissions Health and

Physical Change System Effects Social Cost Categories(r)(10)

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Environmental Impacts

Health Impacts

ConstructionOutage Time

(12)(i)—Energy Consumption

Shareholders

Ratepayers

Economic Impacts (Jobs, Taxes)System Efficiency

& Capacity Changes

Stack Emission Changes

Electricity Price & Output Changes

12(iii)—Emissions Health and Environment

May 4—Reliability Impacts

Must 2—Pollutant Impacts

(10)(iii)—Outages and Other



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Environment. These emissions are a factor that Directors are required to consider (Must 2—

Pollutant Impacts).

Outages for equipment installation occur when facilities are unable to access cooling

water. This is the case during certain undertakings such as expanding an existing intake or

connecting wedgewire screens or cooling towers. Much of the time required for installing cooling

towers can occur with the units on line. Connecting supply and return lines to the towers would

require that the units be off-line. The engineering evaluation indicates that five weeks of off-line

time would be required. This outage time is specified to occur from March through April to avoid

working on the tie-in through the peak of winter.

The effect of an outage for equipment installation is evaluated by modeling the outage

within the context of the relevant power and economic systems. This is accomplished by

developing a counterfactual “With Construction Outage” specification. Unit capacity is set at zero

over the specified outage period. With capacity adjusted in this manner, a power system

simulation model (Environmental Policy Simulation Model [EPSM]) is operated and differences in

operations across Baseline and With Construction Outage conditions are evaluated (Veritas

Economics 2011).

Backpressure and Equipment Load Certain other effects become important once entrainment reduction is underway. These

are most pronounced with cooling towers. As depicted in the figure below, cooling towers require

electricity to operate. This leads to net electrical generation efficiency/capacity effects and energy

consumption that must be identified under (r)(12), (12)(i)—Energy Consumption. As with outages,

these energy consumption changes have social costs and lead to stack emission changes. The

Rule requires assessing related effects under (r)(12), (12)(i)—Energy Consumption, (12)(ii)—

Emissions Health and Environment, and these are a factor Directors must consider (Must 2—

Pollutant Impacts). Moreover, there is significant discussion in the preamble of the Final Rule

indicating the importance of related effects.1,2

1 “… the social cost of the energy penalty is the cost of generating the electricity that would otherwise be available for

consumption except for the energy penalty. Again, an assessment of these costs would be determined under the §122.21(r)(10) demonstration” (79 Fed. Reg. 158, p. 48370).

2 “EPA’s review of emissions data … suggests that impacts from these pollutant discharges could be significant. These include the human health and welfare and global climate change effects—all associated with a variety of pollutants that are emitted from fossil fuel combustion” (79 Fed. Reg. 158, p. 48341).



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Figure 2: Effects of Operating Cooling Towers—Backpressure, Pumps Operation,

and Fans Operation

When there are important efficiency effects, these lead to variable hourly unit-level

efficiency changes and system-level cost and emission impacts. The evaluated cooling tower

retrofits are specified to operate with the existing condenser and turbine configuration. The

implication is that there will be the potential for important backpressure effects. Based on cooling

tower and condenser parameters, water temperatures to unit performance, local meteorological

data (wet bulb), and estimated inlet water temperatures, estimates of hourly capacity impacts

have been developed in the hourly energy penalty study.

As the hourly energy penalty evaluation describes, differences between once-through

water temperatures and closed-cycle temperatures lead to capacity/output losses in nearly all

hours of the year. Pump and fan requirements add an additional load. Subtracting these from

the capacity identified with backpressure changes reveals the capacity available when operating

cooling towers.

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System & Unit Efficiency &

Capacity Changes

Backpressure

Pumps Operation

Fans Operation

Environmental Impacts (Acid Rain)

Health Impacts (COPD)

Physical Change System Effects Social Cost/Benefit Categories (r)(10)

Property ValuesIncreased Decibels

(12)(i)—Energy Consumption

(12)(iii)—Emissions Health and Environment

(12)(iv)—Noise Changes

Noise

Shareholders

Ratepayers

Economic Impacts (Jobs, Taxes)

Electricity Price & Output Changes

Must 2

(10)(iii)—Outages and Other

Stack Emission Changes—Pollutant

Emissions



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Power System The outage and operational implications described previously are initial physical effects.

These physical effects would be registered in the power system as increases in the costs of

meeting load—i.e., social costs. Accordingly, understanding how these physical effects would

ultimately be reflected as social costs requires considering the relevant power system and

AWPP’s operations.

The outage and operational implications described previously are initial physical effects.

These costs would be reflected in the power system as social costs. Understanding how these

physical effects would ultimately be reflected as social costs requires considering the relevant

power system vis-a-vis AWPP owners.

AWPP is geographically located within Zone 6 of the Midcontinent Independent System

Operator (MISO) regional transmission organization. Headquartered in Carmel, Indiana, MISO

provides electric reliability and coordination services in nine geographically defined local resource

zones across fifteen states and Manitoba, Canada. Excess generation at AWPP is bid into Zone

6 and dispatched at least cost to participating members. Figure 3 presents MISO and Zone 6.



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Figure 3: MISO and Zone 6



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Power System Simulation Power system effects from capacity losses are identified by specifying relevant Baseline

and Counterfactual conditions and then simulating outcomes using the MISO Zone 6 module of

Veritas’ 316(b)-focused power system model—the Environmental Policy Simulation Model

(EPSM) (Veritas Economics 2011). Figures 4 and 5 provide a conceptual illustration of EPSM’s

modeling process. In these figures, the vertical bars represent generating units. The height of

each bar represents each unit’s marginal cost and the width represents its capacity. The figures

represent an individual hour out of the 8,760 hours in a year. System electrical load for that hour

is represented by the green line.

Figure 4 represents market outcomes under Baseline conditions. The market clearing

price is set where load intersects the dispatch order (slightly below $50 per MWh). The dispatched

units (in grey) all produce electricity at this price or less. The units that are not dispatched (in

white) are all more expensive to operate. The total cost of meeting load is represented by the

area of the shaded units. An operating unit (or equivalently an amount of generating capacity)

that is to be taken off-line is identified.

Figure 4: Electricity Market Under Baseline Conditions

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80

Generating Units

10

Cos

t per

Hou

r (D

olla

rs)

70

60

50

40

30

20

0

Market supplyMarket demand

Legend:

90

Unit to be Removed

Less Expensive to Operate More Expensive to Operate



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Figure 5 depicts the power system outcomes when this previously operating capacity is

no longer available. As this figure indicates, when a previously operating generation capacity is

removed from the stack, previously more expensive units “shift” to the left. Additional capacity

must operate to meet the existing load (which is fixed in this one-hour example). During other

time periods (not pictured), load moves in and out. Power is more expensive to generate at all

load levels above the generation cost of the previously operating unit (slightly under $40 in Figure

4). Additional outcomes include changes in fuel consumption and emissions as different units

operate.

Figure 5: Electricity Market Under With-Regulation Conditions that Reduce Capacity

Veritas-0134

Baseline supplyWith regulation supply

Legend:

80

10

Cos

t per

Hou

r (D

olla

rs)

70

60

50

40

30

20

0

90

Less Expensive to Operate More Expensive to Operate

Generating Units

Demand

The circled area is an input to social costing (r)(10)(iii)

Changes in energy consumption (r)(12)(i) and emissions (r)(12)(iii) and Must 2 come from this effect, as well



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Quantitative Evaluation The conceptual process described in Section 1 is implemented for AWPP by carrying out

the following steps within EPSM’s Zone 6 power system module:

1. Estimate hourly energy penalty

2. Specify total 2015 hourly load for Zone 6.

3. Calibrate Zone 6 module consistent with 2015 load and 2015 AWPP operations.

4. Create scenarios representing AWPP conversion and ongoing operations.

5. Run EPSM to identify counterfactual dispatch.

6. Calculate differences in fuel consumption and costs.

These steps are implemented as follows.

Estimate Hourly Energy Penalty The energy penalty evaluation is an important input to a number of studies necessary for

the 122.21(r)(12) report and also social costs that must be studied under 122.21(r)(10). Energy

penalties arise from “slightly lower generating efficiency attributed to higher turbine backpressure

when the condenser is not replaced with one optimized for closed cycle operation when retrofitting

existing units” (79 Fed. Reg. 158, 48341). Studying energy penalty effects is important because:

(1) They relate directly to energy consumption, which must be studied under (r)(12)(i).

“The study must include the following: Estimates of changes to energy consumption, including but not limited to auxiliary power consumption and turbine backpressure energy penalty” (§122.21(r)(12), 79 Fed. Reg. 158, page 48428).

(2) They produce indirect and direct social costs, which must be studied under (r)(10).

“EPA is using energy penalty to mean only the opportunity costs associated with reduced power production due to derating (turbine backpressure)” (79 Fed. Reg. 158, 48370).

“… the social cost of the energy penalty is the cost of generating the electricity that would otherwise be available for consumption except for the energy penalty. Again, an assessment of these costs would be determined under the §122.21(r)(10) demonstration” (79 Fed. Reg. 158, 48370).

(3) They affect air emissions, which must be studied under (r)(12)(iii).

“…increased air emissions … due to the energy penalty” (79 Fed. Reg. 158, 48341)



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“The study must include the following: … Estimates of air pollutant emissions and of the human health and environmental impacts associated with such emissions. (79 Fed. Reg. 158, 48428)

(4) These air emissions lead to environmental, health, and social cost (welfare effects),

which must be studied under §122.21(r)(12)(iii) and (r)(10):

“…due to the energy penalty when retrofitting to cooling towers” related to “human health, welfare, and global climate” (79 Fed. Reg. 158, 48341).

“Estimates of air pollutant emissions and of the human health and environmental impacts associated with such emissions” (79 Fed. Reg. 158, 48428).

The required studies under (r)(12) are described as “a detailed, facility-specific

discussion.” Both (r)(10) and (r)(12) reports are subject to peer review (79 Fed. Reg. 158, 48368).

Energy efficiency impacts result in important social costs and can also be an important

determinant in their own right. For example, decision-makers looking ahead to greenhouse gas

requirements may find these effects and their costs more important than comparable capital costs.

Unlike losses from operating pumps and fans, the energy penalty effect is difficult to

generalize. Energy penalties on the hottest days of summer can be higher (EPRI 2011; U.S.

Department of Energy Office of Electricity Delivery and Energy Reliability 2008). The U.S.

Department of Energy estimates that the energy penalty associated with wet cooling towers, for

a fossil plant in the Great Lakes Region, is about 1.5 percent for the annual average temperature

conditions and about 3.1 percent for the hottest months of the year.

Energy Penalty Study Approach The temperature of cooling water affects turbine performance. Colder cooling water

improves unit efficiency (EPRI 2011). Energy penalty effects are due to the different cooling water

temperature of cooling towers compared with that of once-through waterbody temperature. With

once-through cooling, the cooling water is the temperature of the source waterbody. With closed-

cycle cooling, the cooling water temperature is related to cooling tower design characteristics and

atmospheric conditions, in particular wet-bulb temperatures.

As wet-bulb temperatures increase, units cooled by closed-cycle recirculating systems

become less efficient. As noted by EPA, “the cost may be incurred by the facility … or by another

generating unit” (79 Fed. Reg. 158, 48370). Fossil facilities are able to “over-fire” to compensate

for efficiency impacts. Depending upon operational considerations, these facilities may



Veritas

experience increased fuel costs and less dramatic capacity reductions.3 Generally speaking,

capacity reductions are experienced when fuel input is at the boiler rated maximum and/or unit

backpressure at the highest tolerated point. At this point, fossil units cannot increase btu input,

and therefore experience capacity reductions. Nuclear units cannot vary fuel input. In both cases,

costs (and environmental effects) of providing lost electricity are incurred by other units.4

Figure 6 depicts the generalized approach for identifying efficiency effects from a closed-

cycle conversion. The approach uses the baseline and counterfactual structure recommended in

EPA (1991) Guidelines for Preparing Regulatory Impact Analysis. The baseline (red) input-output

curve has output limited by line 1 and input (in BTUs) limited at line 2 (number of BTUs per kilowatt

hour.) With an energy penalty from operating the cooling tower, the new input-output curve is

represented by the blue line. If the unit cannot over-fire, the output is limited to where line 2

intersects the blue curve as indicated by line 3. Auxiliary load increases as cooling tower fans

are operated. This is modeled as the shift in capacity to line 4. The original fuel input is maintained

to serve the parasitic load. The resulting input-output curve (5) represents reduced efficiency and

lost net capacity.

3 An important consideration is that both electricity prices and cooling tower performance are correlated with wet-bulb

temperatures. 4 When cooling towers result in lower cooling water temperatures, the opposite occurs.



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Figure 6: Potential for Efficiency Effects from Closed-Cycle Cooling

Because atmospheric conditions vary hourly, these curves move up and down. Figure 7

depicts the energy penalty effect for time periods when the source water body water is cooler than

the cooling tower water. As depicted in the figure, the magnitude of the energy penalty depends

upon fixed (time invariant) technical factors including the slope of the turbine back pressure curve

and cooling tower design parameters. The energy penalty also depends upon factors that vary

somewhat predictably over the course of a year including source waterbody temperatures and

wet bulb temperatures. To evaluate this effect, these are combined in baseline and counterfactual

simulations.

500 MW Output

5,000

00

\

BTU/hr Input

2

1

3

4

Baseline

5

With Cooling Tower(does not over-fire)

With Cooling Tower(does over-fire)

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Does not over-fire

Does over-fire



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Figure 7: Technical Parameters and Ambient Conditions Underlie Efficiency Effects

500 MW Output

5,000

0

BTU / kWh

Exhaust Pressure: In. Hg. Abs.

10.0

3.02.01.00.0−1.0

0 0.5 1.0 3.0 3.5 4.54.0 5

9.08.07.06.05.04.0

1.5 2.52.0

% Increase in Heat Rate

Turbine Backpressure Curve Heat RateVeritas-0151

Condenser Design

Parameters

Cooling Tower Design

ParametersWet Bulb

Temperature

Exhaust Pressure

Once-Through Condensing Temperature

Closed-Cycle Condensing Temperature

Closed-Cycle Cooling Water Temperature

Once-Through Cooling Water Temperature



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Because this effect exhibits a good deal of nonlinear variability, we characterize it on an

hourly basis.5 Details for doing so (including equations) are presented in EPRI (2011). The

approach follows these general steps:

• Step 1—Collect and compile hourly ambient conditions data.

• Step 2—Calculate approach.

• Step 3—Calculate cooling tower circulating temps.

• Step 4—Estimate the water temperature to heat rate curve

• Step 5—Determine efficiency impacts.

This results in an estimated hourly energy penalty effect that is specific to the atmospheric, water

temperature and operating characteristics of the unit and tower and is relative to baseline

conditions.

Step 1—Source Water and Wet Bulb Data Information requirements for hourly ambient conditions include open-cycle source water

temperatures and wet-bulb temperatures. Ideal information is hourly inlet temperatures measured

at each intake which is not available for this draft report. The nearest available public data are

from the USGS National Water Information System for the Ohio River (USGS 03612600 Ohio

River at Olmstead, IL).6 Figure 8 depicts the data employed for this study.

5 Turbine backpressure curves are steepest and electricity prices are often highest when wet bulb temperatures are

high. 6https://nwis.waterdata.usgs.gov/nwis/uv?cb_00010=on&format=html&site_no=03612600&period=&begin_date=2015

-01-01&end_date=2015-12-31

https://nwis.waterdata.usgs.gov/nwis/uv?cb_00010=on&format=html&site_no=03612600&period=&begin_date=2015-01-01&end_date=2015-12-31

https://nwis.waterdata.usgs.gov/nwis/uv?cb_00010=on&format=html&site_no=03612600&period=&begin_date=2015-01-01&end_date=2015-12-31



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Figure 8: Hourly Once-Through Source Water Temperature

Wet bulb data is available from the National Oceanic & Atmospheric Administration’s

(NOAA) National Environmental Satellite, Data, and Information Service. The nearest publicly

available readings are from the Evansville Regional Airport in Evansville, Indiana.7 Hourly wet-

bulb temperatures were developed by collapsing continuous wet-bulb data to hourly data (by

averaging within-hour readings) and are presented in Figure 9.

Figure 9: Hourly Wet Bulb Temperature Data for AWPP

7 The source for this data is available from the following url: https://www.ncdc.noaa.gov/cdo-web/datasets/LCD/stations/WBAN:93817/detail

https://www.ncdc.noaa.gov/cdo-web/datasets/LCD/stations/WBAN:93817/detail



Veritas

Step 2—Calculate Cooling Tower Circulating Temperatures For the cooling tower, the approach is calculated using the following equation (EPRI

2009):

CT Approach = 0.5 * CT Wet Bulb Design + CT Design Approach - 0.5 * Hourly Wet Bulb

where

CT = Cooling Tower CT Wet Bulb Design = 74.7 CT Design Approach = 7 (1)

Cooling tower hourly approaches are depicted in Figure 10.

Figure 10: Hourly Approach Temperatures for AWPP

Step 3—Calculate Cooling Tower Circulating Temps Having information on cooling tower hourly approach and hourly wet bulb, circulating water

temperatures for cooling towers are calculated following EPRI (2009) as:

ThCooling = Th

Wet Bulb + Approachh (2)

where

ThCooling = Hourly cooling tower circulating water temperature

ThWet Bulb = Hourly wet bulb temperature

Approachh = Hourly cooling tower approach temperature.



Veritas

Figure 11 depicts cooling water temperatures for once-through cooling (red curve) and closed-

cycle cooling (blue curve).

Figure 11: Cooling Water Temperatures for Once-Through and Closed-Cycle Cooling

for AWPP

Step 4—Estimate the Water Temperature to Heat Rate Curve For fossil plants such as AWPP, plant fuel input varies. Unit output and heat rate varies

with each units’ operational state (e.g., startup versus running) and with cooling water

temperatures and fuel input. For most units, hourly output (in kw) and fuel input (in mmBtu/hr) is

available from the continuous emissions monitoring data (CEMS) collected by EPA’s Air Markets

Program.8 With this information, the relationship between cooling water temperatures and heat rate

can identified by solving for hourly heat rate as Btu/kW-hr and then statistically fitting to water

temperatures.9 Although data for AWPP is not publicly available such evaluations have been

conducted for similar size and age coal units. Statistical modeling for these units consistently

return high levels of statistical significance and water temperature to heat rate relationships similar

to those depicted below.

Heat Rate = 9.10 + 0.010 * Water Temperature

8 Data are located at http://ampd.epa.gov/ampd/. 9 Data preparation procedures include certain validation and cleaning activities, such as eliminating data that appears

to come during ramping periods.

http://ampd.epa.gov/ampd/



Veritas

This equation is depicted graphically depicted below.

Figure 12: Specified Relationship between Water Temperature and Heat Rate

Step 5—Determine Efficiency/ Capacity Impacts Having the hourly cooling water temperatures and the equations that relate cooling-water

temperature to output, these are used to identify heat rate under baseline and with cooling towers

conditions. Figure 13 depicts heat rate for once-through and closed-cycle cooling.

Figure 13: Hourly Heat Rate for AWPP

The red line represents baseline heat rate and the blue line represents the heat rate using

closed-cycle cooling water. As the figures indicate, when using this warmer water, there is a loss



Veritas

in efficiency for every hour. Whereas once-through efficiencies relate to source water

temperatures, closed-cycle efficiencies are related to atmospheric heat and humidity (that is, wet

bulb temperatures). This leads to the more variable hourly effect evident in blue.

Specify Hourly Load for Zone 6 Because electricity production costs vary hourly and because important cooling tower

effects are hourly, modeling power system effects at the hourly level is useful. Modeled hourly

load is specified as MISO Zone 6 load for the 8,760 hours of 2015 (Figure 14).

Figure 14: MISO Zone 6 2015 Hourly Load

Operate Model Under Baseline Conditions Under Baseline conditions, operations are consistent with typical operating practices. The

relationship between output and fuel consumption includes variation in cooling water temperature

which lead to an hourly varying heat rate as depicted in Figure 15.



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Figure 15: AWPP Baseline Heat Rate

Under baseline conditions maximum capacity also varies by hour. Operating the model

under these Baseline conditions should produce results that are consistent with historical

operations. Figure 16 depicts Baseline simulated output. This is similar to capacity factors in the

engineering evaluation of 90 percent.

Figure 16: Model Simulated AWPP Output



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Create Scenarios Representing AWPP Conversion and Ongoing Operations Counterfactual scenarios are created for two years. These reflect the physical implications

of an outage for conversation and ongoing operations at AWPP. For the year of the outage, Burns

and McDonnell identified a five-week outage for conversion purposes. This was specified to begin

in mid-March (at hour 1800) and end in late April (at hour 2640). Post-conversion operations

reflect net efficiency reductions from backpressure effects and auxiliary load.

Net output reductions were estimated by Burns and McDonnell as 11.8 MW in the summer

and 9.7 MW in the winter. Gross output reductions were estimated at 2.3 MW in the summer and

0 in the winter. Summer is the warmest 60 percent of hours and winter is the colder remaining

40 percent. Net reductions are attributed to auxiliary load with the expectation that the 2.1 MW

represents reductions in fan power.

Run Simulations to Create Counterfactual Dispatch With the counterfactual conditions set, the model is simulated to identify the counterfactual

outcomes. These counterfactual outcomes are similar to those depicted in Figure 17. As Figure

17 indicates, additional units are dispatched to make up for lost net generation. Under a least cost

dispatch approach, this leads to equal or higher hourly costs. Figure 17 depicts the change in

costs that occur when there is an outage for a conversion followed by the operation of a cooling

tower.

Figure 17: MISO Region 6 Incremental Hourly Costs in Conversion Year



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As Figure 17 indicates, there is no change in costs up until hour 1800 when the outage

occurs. At this point, offsetting lost generation from AWPP goes up to over $2,000 per hour. After

the plant with cooling tower is back on line (at hour 2641), ongoing incremental costs of over $200

per hour cost are incurred because of auxiliary load and backpressure effects.

A typical year with cooling tower operation has costs like those of the post-conversion

period depicted in Figure 17. However, these effects occur over the entire year as depicted in

Figure 18. As Figure 18 indicates, ongoing costs reach up to $350 per hour.

Figure 18: MISO Zone 6 Incremental Hourly Costs in Typical Year

Calculate Net Differences in Fuel Consumption, Costs, and Emissions The changes in dispatch that lead to cost increases are also associated with changes in

fuel consumption and emissions. Table 1 summarizes these fuel and fuel cost increases as well

as the associated increase in emissions.



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Table 1: Incremental Costs, Fuel Consumption, and Emissions

Technology Metric Conversion

Year Typical Year

Closed-Cycle Cooling Fuel Costs $2.823M $2.304M

Fuel (MMbtu) 690.1K 672.2K

CO2 (tons) 60.1K 52.4K

SO2 (tons) 6.2 5.4

NOx (tons) 25.2 21.1

Fine Mesh Traveling Screens 2.0mm

Fuel Costs $6.8K $9.7K

Fuel (MMbtu) 1.9K 2.8K

CO2 (tons) 154.8 221.5

SO2 (tons) 0.01 0.02

NOx (tons) 0.07 0.09 Cylindrical Wedgewire Screens 2.0mm

Fuel Costs $6.8K $9.7K

Fuel (MMbtu) 2.0K 2.8K CO2 (tons) 154.8 221.5 SO2 (tons) 0.02 0.02 NOx (tons) 0.06 0.09



Veritas

References EIA. 2017. U.S. Energy Information Administration, Independent Statistics & Analysis: “Coal

Explained: Coal and the Environment”. Available at https://www.eia.gov/energyexplained/?page=coal_environment. Retrieved on November 15, 2016.

Electric Power Research Institute. 2009. Entrainment Survival: Status of Technical Issues and Role in Best Technology Available (BTA) Selection. Product ID 1019025. Palo Alto, CA: EPRI.

Electric Power Research Institute. 2011. Full-Time/Seasonal Closed-Cycle Cooling: Cost and Performance Comparisons. 1023100. Palo Alto, CA: Electric Power Research Institute. Principal Investigators: Maulbetsch Consulting, DiFilippo Consulting, and Veritas Economic Consulting, LLC.

UCS. 2017. Union of Concerned Scientists: Environmental Impacts of Coal Power: Air Pollution”. Available at http://www.ucsusa.org/clean-energy/coal-and-other-fossil-fuels/coal-air-pollution#.WcEncWwiyUm. Retrieved on November 15, 2016.

U.S. Department of Energy Office of Electricity Delivery and Energy Reliability. 2008. Electricity Reliability Impacts of a Mandatory Cooling Tower Rule for Existing Steam Generation Units. Available at http://www.netl.doe.gov/energy-analyses/pubs/Cooling_Tower_Report.pdf. Retrieved on September 15, 2015.

U.S. Environmental Protection Agency. 1991. Guidelines for Preparing Regulatory Impact Analysis. Available at http://yosemite.epa.gov/ee/epa/eerm.nsf/vwAN/EE-0228A-1.pdf/$file/EE-0228A-1.pdf. Retrieved on August 5, 2014.

Veritas Economic Consulting. 2011. “Veritas Economics Environmental Policy Simulation Model (EPSM).” Working Paper 2011-01. Cary, NC: Veritas Economic Consulting, LLC. Available at http://www.veritaseconomics.com/Working%20Papers/EPSM_201101.pdf.

- MODIFIED TRAVELING SCREEN SKETCHES

Figure C-1: Example of Four Post Thru-Flow Traveling Water Screen

Source: Atlas, 2017

Figure C-2: Example of Typical Basket Assembly

Source: Atlas, 2017

Figure C-3: Example of Typical Spray Wash Assemblies

Source: Atlas, 2017

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EXISTING INTAKE

POTENTIAL FISH RETURN LOCATION

RETURN LOCATION

POTENTIAL FISH

3/3/17

FISH TROUGH

SCALE IN FEET

30' 60'0

- CYLINDRICAL WEDGEWIRE SCREEN SKETCH

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WA-SK03

STRUCTURE

INTAKE

ASECTION

SCALE IN FEET

50' 100'0

SCALE IN FEET

25' 50'0

VERTICAL:

HORIZONTAL:

WARRICK GENERATING STATION

SCALE IN FEET

50' 100'0

N

NOTES:

4.

3.

2.

1.

STRUCTUREEXISTING INTAKE

FOR HYDROBURST SYSTEMPROPOSED LOCATION

EL 324'

(SEE NOTE 3)

BLANKING PLATE

EL 395.5'

A

(SEE NOTE 2)

RIVER BOTTOM EL = 324

BUOY (TYP)

AIR LINE

WARM WATER RECIRC

DURING DESIGN PHASE.

SUPPORTED BY PIPE PILES. DETAILS WILL NEED TO BE COORDINATED WITH USACE

NEW SCREENS AND PIPING WILL LIKELY BE MOUNTED ON A STEEL FRAME AND

STRUCTURE.

BLANKING PLATE TO BE SUPPORTED FROM EXISTING BAR SCREEN SUPPORT

IMPROVEMENTS. BATHYMETRY OUTSIDE OF INTAKE CHANNEL IS UNKNOWN.

BATHYMETRY BASED ON DWG A-105721-PE CIRCULATING WATER INTAKE CHANNEL

SCREEN SIZE BASED ON 400,000 GPM INTAKE CAPACITY.

LOW WATER EL = 357.46

6' DIA PIPE

10' DIA INTAKE PIPE

(96" DIA x 317" LENGTH, TYP)

CYLINDRICAL SCREEN

2-MM MESH

Burns & McDonnell World Headquarters 9400 Ward Parkway

Kansas City, MO 64114 O 816-333-9400 F 816-333-3690

www.burnsmcd.com

http://www.burnsmcd.com/