vvEPA
United States
Environmental Protection
Agency
Technical Development
Document for the
Final Section 316(b) Existing
Rule
EPA-821-R-14-002
May 2014
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U.S. Environmental Protection Agency
Office of Water (4303T)
1200 Pennsylvania Avenue, NW
Washington, DC 20460
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Acknowledgements and Disclaimer
This document was prepared by Office of Water staff. The following contractors provided
assistance in performing the analyses supporting the conclusions detailed in this document.
Tetra Tech, Inc.
Office of Water staff have reviewed and approved this document for publication. Neither the
United States Government nor any of its employees, contractors, subcontractors, or their
employees makes any warranty, expressed or implied, or assumes any legal liability or
responsibility for any third party' s use of or the results of such use of any information, apparatus,
product, or process discussed in this document, or represents that its use by such a party would
not infringe on privately owned rights.
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§ 316(b) Existing Facilities Final Rule - TDD Contents
Contents
Chapter 1: Background 1-1
1.0 Introduction 1-1
1.1 Purpose of Technical Development Document and Final Regulation 1-1
1.2 Background 1-2
Chapter 2: Summary of Data Collection Activities 2-1
2.0 Introduction 2-1
2.1 Primary Data Sourced from Previous 316(b) Rulemakings 2-1
2.1.1 Survey Questionnaires 2-1
2.1.2 Technology Efficacy Data 2-2
2.1.3 Existing Data Sources 2-2
2.1.4 Public Participation Activities 2-2
2.2 New Data Collected 2-3
2.2.1 Site Visits 2-3
2.2.2 Data Provided to EPA by Industrial, Trade, Consulting, Scientific or
Environmental Organizations or by the General Public 2-8
2.2.3 Updated Technology Information 2-10
2.2.4 Other Resources 2-11
2.2.5 Implementation Experience 2-15
2.2.6 New or Revised Analyses 2-18
Chapter 3: Scope/Applicability of Final Rule 3-1
3.0 Introduction 3-1
3.1 General Applicability 3-2
3.1.1 What is an "Existing Facility" for Purposes of the Final Rule? 3-3
3.1.2 What is "Cooling Water" and What is a "Cooling Water Intake
Structure?" 3-4
3.1.3 Would My Facility Be Covered Only if it is a Point Source
Discharger? 3-4
3.1.4 Would My Facility Be Covered if it Withdraws Water From Waters of
the United States? What if My Facility Obtains Cooling Water from
an Independent Supplier? 3-5
3.1.5 What Intake Flow Thresholds Result in an Existing Facility Being
Subject to the Final Rule? 3-7
3.1.6 Existing Offshore Oil and Gas Facilities, Seafood Processing Vessels
or LNG Import Terminals BTA Requirements Under the Final Rule 3-10
3.1.7 What is a "New Unit" and How Are New Units Addressed Under the
Final Rule? 3-10
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Contents § 316(b) Existing Facilities Final Rule - TDD
Chapter 4: Industry Description 4-1
4.0 Introduction 4-1
4.1 Industry Overview 4-2
4.1.1 Major Industry Sectors 4-2
4.1.2 Number of Facilities and Design Intake Flow Characteristics 4-3
4.1.3 Source Waterbodies 4-6
4.1.4 Cooling Water System Configurations 4-8
4.1.5 Design and Operation of Cooling Water Intake Structures 4-11
4.1.6 Existing Intake Technologies 4-14
4.1.7 Age of Facilities 4-14
4.1.8 Water Reduction Measures at Manufacturers 4-15
4.1.9 Land-based Liquefied Natural Gas Facilities 4-19
4.2 Electricity Industry 4-19
4.2.1 Domestic Production 4-20
4.2.2 Prime Movers 4-21
4.2.3 Steam Electric Generators 4-24
4.3 Manufacturers 4-26
4.3.1 Electric Generation at Manufacturers 4-26
4.4 Glossary 4-26
4.5 References 4-29
Chapter 5: Subcategorization 5-1
5.0 Introduction 5-1
5.1 Methodology and Factors Considered for Basis of Subcategorization 5-1
5.2 Age of the Equipment and Facilities 5-1
5.3 Processes Employed 5-2
5.3.1 Electric Generators 5-2
5.3.2 Manufacturers 5-5
5.4 Existing Intake Type 5-6
5.5 Application of Impingement and Entrainment Reduction Technologies 5-7
5.6 Geographic Location (including waterbody category) 5-8
5.7 Facility Size 5-10
5.7.1 Intake Flow 5-10
5.7.2 Intake Flow and Impacts 5-15
5.7.3 Intake Flow and Business Size 5-21
5.7.4 Intake Flow and Cost 5-24
5.7.5 Generating Capacity 5-26
5.8 Non-Water Quality Environmental Impacts 5-27
5.9 Other Factors 5-28
5.9.1 Capacity Utilization 5-28
5.9.2 CUR Versus DIF 5-32
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§ 316(b) Existing Facilities Final Rule - TDD Contents
5.9.3 Low Capacity Utilization Compared With Spawning Seasonality 5-33
5.9.4 Fish Swim Speed 5-35
5.9.5 Water Use Efficiency 5-36
5.9.6 Land Availability 5-38
5.9.7 Fish Species 5-39
5.9.8 Other Factors 5-40
5.10 Conclusion 5-40
Chapter 6: Technologies and Control Measures 6-1
6.0 Introduction 6-1
6.1 Flow Reduction Technologies and Control Measures 6-2
6.1.1 Closed-Cycle Recirculating Systems 6-2
6.1.2 Variable Speed Pumps/Variable Frequency Drives 6-13
6.1.3 Seasonal Flow Reductions 6-17
6.1.4 Water Reuse 6-18
6.1.5 Alternate Cooling Water Sources 6-19
6.2 Screening Technologies 6-19
6.2.1 Conventional Traveling Screens 6-23
6.2.2 Modified Coarse Mesh Traveling Screens 6-24
6.2.3 Geiger screens 6-36
6.2.4 Hydrolox screens 6-38
6.2.5 Beaudrey W Intake Protection (WIP) Screen 6-39
6.2.6 Coarse Mesh Cylindrical Wedgewire 6-41
6.2.7 Fine Mesh Screens 6-44
6.2.8 Drum Screens 6-52
6.3 Barrier nets 6-53
6.3.1 Technology Performance 6-53
6.3.2 Facility Examples 6-53
6.4 Aquatic Filter Barrier 6-55
6.4.1 Technology Performance 6-56
6.4.2 Facilities Examples 6-56
6.5 Offshore Intakes 6-56
6.5.1 Intake Location 6-57
6.5.2 Velocity Cap 6-59
6.5.3 Technology Performance 6-60
6.5.4 Facility Examples 6-63
6.6 Other Technologies and Operational Measures 6-65
6.6.1 Physical Design 6-65
6.6.2 Reduce Intake Velocity 6-66
6.6.3 Substratum Intakes 6-67
6.6.4 Louvers 6-68
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Contents § 316(b) Existing Facilities Final Rule - TDD
6.6.5 Behavioral Technologies 6-68
6.7 Summary of Technology Performance 6-69
6.8 References 6-71
Chapter 7: Regulatory Options 7-1
7.0 Introduction 7-1
7.1 Technology Basis Considered for the Proposed Regulation 7-1
7.1.1 Impingement Mortality Standards for Existing Facilities 7-2
7.1.2 Entrainment Standards for Existing Units 7-3
7.1.3 Impingement and Entrainment Standards for New Units at Existing
Facilities 7-4
7.2 Options Considered 7-4
7.2.1 Final Rule 7-4
7.2.2 Other Options Considered 7-6
7.2.3 Existing offshore oil and gas extraction facilities and seafood
processing vessels 7-11
Chapter 8: Costing Methodology 8-1
8.0 Introduction 8-1
8.1 Compliance Costs Developed for the Final Rule 8-2
8.1.1 Model Facility Approach 8-2
8.2 Impingement Mortality Compliance Costs 8-3
8.2.1 Select!on of Technology to Address EVI 8-4
8.2.2 EPA's Cost Tool 8-5
8.2.3 Identifying Intakes That Are Already Compliant With Impingement
Mortality Requirements 8-16
8.2.4 Development of Cost Tool Input Data 8-16
8.3 Entrainment Mortality Compliance Costs 8-21
8.3.1 Capital Costs 8-23
8.3.2 O&M Costs 8-29
8.3.3 Energy Penalty 8-31
8.3.4 Construction Downtime 8-32
8.3.5 Identifying Intakes That Are Already Compliant With Entrainment
Mortality Requirements 8-36
8.4 Compliance Costs for New Units 8-37
8.4.1 Compliance Costs for New Power Generation Units 8-37
8.4.2 Compliance Costs for New Manufacturing Units 8-42
8.5 Impingement Mortality Costs at Intakes with Cooling Systems Required to
Install Closed-Cycle Cooling 8-44
8.6 Costs for Each Regulatory Alternative 8-45
8.7 Compliance Costs Developed for Analysis of National Economic Impacts.... 8-45
8.7.1 Selection of DIP as the Primary Scaling Factor for Power Plants 8-46
8.7.2 Development of EVI&EM Control Costs for IPM Model 8-47
IV
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§ 316(b) Existing Facilities Final Rule - TDD Contents
8.7.3 Development of Closed-Cycle Cooling Tower Costs for IPM Model 8-49
8.7.4 Cost to Comply with Streamlined Compliance and Alternative
Provisions Option 8-49
Chapter 9: Impingement Mortality and Entrainment Mortality Reduction
Estimates 9-1
9.0 Introduction 9-1
9.1 Technology Reduction Estimates 9-1
9.1.1 Screens 9-1
9.1.2 Low Intake Velocity 9-1
9.1.3 Existing Offshore Velocity Cap 9-2
9.1.4 Flow Reduction Commensurate with Closed-Cycle Cooling 9-2
9.2 Assigning a Reduction to Each Model Facility 9-3
9.2.1 Entrainment Mortality 9-5
9.2.2 In-Place Technologies 9-5
9.2.3 Summary of Options 9-5
Chapter 10: Non-water Quality Impacts 10-1
10.0 Introduction 10-1
10.1 Air Emissions Increases 10-1
10.1.1 Incremental Emissions Increases 10-2
10.1.2 GIS Analysis 10-6
10.2 Vapor Plumes 10-7
10.3 Displacement of Wetlands or Other Land Habitats 10-8
10.4 Salt or Mineral Drift 10-8
10.5 Noise 10-9
10.6 Solid Waste Generation 10-10
10.7 Evaporative Consumption of Water 10-10
10.8 Thermal Effluent 10-11
10.9 References 10-12
Appendix to Chapter 10: Non-water Quality Impacts 10A-1
Chapter 11: 12 Month Percent Impingement Mortality Standard: Data and
Calculation 11-1
11.0 Introduction 11-1
11.1 Overview of Available Impingement Data 11-1
11.2 Data Acceptance Criteria 11-2
11.3 Facility Data Used As Basis of 12 month Percent Impingement Mortality
Standard 11-5
11.4 Statistical Basis of 12 Month Percent Impingement Mortality Standard 11-8
11.5 Biological and Engineering Reviews of 12 Month Percent Impingement
Mortality Performance Standard 11-10
11.6 Alternative Provision Calculations 11-14
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Contents § 316(b) Existing Facilities Final Rule - TDD
Appendix A to Chapter 11: Impingement Mortality Studies 11A-1
Appendix B to Chapter 11: "Non-Fragile" Species 11B-1
Chapter 12: Analysis of Uncertainty 12-1
12.0 Introduction 12-1
12.1 Uncertainty in Technical Analysis of Impingement Mortality 12-1
12.1.1 Technology in Place and Related Model Facility Data 12-1
12.1.2 Costs of Additional Impingement Mortality Controls 12-1
12.1.3 Cost Drivers for Impingement Mortality Controls 12-3
12.1.4 Analysis of a "De Minimis" Provision 12-3
12.2 Uncertainty in Technical Analysis of Entrainment Mortality 12-4
12.2.1 Intake Location 12-4
12.2.2 Space Constraints 12-6
12.2.3 Development of Cooling Tower Costs 12-7
12.3 Uncertainty in Benefits of I&E Controls 12-8
12.3.1 Reductions in Impingement and Entrainment by Region 12-8
12.3.2 Air Emissions Associated with Closed-Cycle 12-10
12.4 Uncertainty in Model Facility Approach 12-13
12.5 References 12-14
VI
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§ 316(b) Existing Facilities Final Rule - TDD Contents
Exhibits
Exhibit 2-1. Facilities visited by EPA 2-4
Exhibit 2-2. Facilities that provided data to EPA 2-5
Exhibit 2-3. Site visit locations and locations of other site-specific data collected 2-6
Exhibit 2-4. Methods used to address Section 316(a) requirements by EPA
Region 2-21
Exhibit 2-5. Methods used to address Section 316(b) requirements by EPA
Region 2-22
Exhibit 3-1. Applicability by phase of the 316(b) rules 3-1
Exhibit 3-2. Applicable requirements of today's rule for existing facilities 3-1
Exhibit 3-3. Plot of Cumulative AIF in MOD 3-9
Exhibit 3-4. Examples of new and existing units at electric generators 3-11
Exhibit 3-5. Examples of new and existing units at manufacturers 3-13
Exhibit 4-1. Cooling water use in surveyed industries 4-4
Exhibit 4-2. Map of facilities subject to 316(b) 4-4
Exhibit 4-3. Distribution of facilities by Design Intake Flow 4-5
Exhibit 4-4. Relative volumes of Design Intake Flow and Average Intake Flow 4-5
Exhibit 4-5. Design Intake Flow by industry type 4-6
Exhibit 4-6. Distribution of source waterbodies for existing facilities 4-6
Exhibit 4-7. Facility intake flows as a percentage of mean annual flow 4-7
Exhibit 4-8. Distribution of cooling water system configurations 4-8
Exhibit 4-9. Distribution of facilities by cooling water system and waterbody type 4-8
Exhibit 4-10. Distribution of cooling water system configurations at nuclear
facilities by waterbody type 4-9
Exhibit 4-11. Distribution of cooling water intake structure arrangements 4-9
Exhibit 4-12. Estimated distribution of cooling water system configurations as a
function of age 4-10
Exhibit 4-13. Estimated distribution of in-scope facilities by the number of
cooling water systems 4-11
Exhibit 4-14. Estimated distribution of in-scope facilities by the number of
cooling water intake structures 4-11
Exhibit 4-15. Electric generators with multiple CWISs 4-12
Exhibit 4-16. Estimated distribution of screen mesh size 4-12
Exhibit 4-17. Distribution of cooling water intake structure design
through-screen velocities 4-13
Exhibit 4-18. Estimated distribution of intakes by average of CWIS operating
days 4-13
VII
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Contents § 316(b) Existing Facilities Final Rule - TDD
Exhibit 4-19. Distribution of intake technologies 4-14
Exhibit 4-20. Age of electric generating units by fuel type 4-15
Exhibit 4-21. Flow reduction at sites visited by EPA 4-16
Exhibit 4-22. Existing generating capacity by energy source (2000 to 2009) 4-21
Exhibit 4-23. Number of existing utility and nonutility facilities by prime mover,
2007 4-23
Exhibit 4-24. Summary of 316(b) electric power facility data 4-24
Exhibit 4-25. Number of 316(b) regulated facilities 4-25
Exhibit 4-26. 316(b) electric power facilities by plant type and prime mover 4-25
Exhibit 4-27. Manufacturers with coal-fired generation 4-26
Exhibit 5-1. Generating efficiency by fuel type 5-2
Exhibit 5-2. Distribution of intake flows for all non-nuclear electric generators 5-3
Exhibit 5-3. Distribution of intake flows for all nuclear electric generators 5-4
Exhibit 5-4. Distribution of nuclear and non-nuclear facilities by waterbody type 5-4
Exhibit 5-5. Distribution of nuclear and non-nuclear facilities by cooling system
type 5-5
Exhibit 5-6. Example of local reliability concerns 5-9
Exhibit 5-7. Normalized DIP at Phase II and III electric generating facilities 5-11
Exhibit 5-8. Distribution of intake flows for all electric generators 5-12
Exhibit 5-9. Distribution of normalized DIP for all electric generators 5-12
Exhibit 5-10. Distribution of DIP (non-normalized) for all electric generators 5-13
Exhibit 5-11. Distribution of normalized AIF for all electric generators 5-13
Exhibit 5-12. Distribution of AIF (non-normalized) for all electric generators 5-14
Exhibit 5-13. Electric generators and flow addressed by various flow thresholds 5-14
Exhibit 5-14. Manufacturers and flow addressed by various flow thresholds 5-15
Exhibit 5-15. Facilities and flow addressed by various flow thresholds 5-15
Exhibit 5-16. Facility Design Intake Flows as a percentage of mean annual flow
for all facilities on rivers/streams and those with DIP < 50 MGD 5-16
Exhibit 5-17. Facility Design Intake Flows as a percentage of mean annual flow
for all facilities and those with DIF < 50 MGD 5-17
Exhibit 5-18. Number of surveyed facilities located on the same river or stream as
other facilities and number contributing to cumulative withdrawals
greater than five percent and 50 percent of mean annual flow 5-18
Exhibit 5-19. Location of facilities in eastern half of United States 5-19
Exhibit 5-20. Representation of facility location proximity in the Eastern US 5-20
Exhibit 5-21. Proportion of facilities with known location one or more other
facilities within each buffer distance 5-21
Exhibit 5-22. Distribution of small businesses by DIF 5-21
VIII
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§ 316(b) Existing Facilities Final Rule - TDD Contents
Exhibit 5-23. Summary of number of small businesses and all businesses with a
DIP less than 50 MGD that are deemed already compliant with the IM
BTA standard 5-22
Exhibit 5-24. Representation of facility location proximity in the eastern US
showing small businesses on rivers and streams with AIF< 50 MGD 5-23
Exhibit 5-25. Total annualized pretax compliance costs above DIP threshold 5-24
Exhibit 5-26. Total annualized pretax compliance costs above DIP thresholds of 2
to 100 MGD 5-24
Exhibit 5-27. Total annualized pretax closed-cycle cooling compliance capital
and O&M above DIP threshold 5-25
Exhibit 5-28. Distribution of nameplate generating capacity 5-26
Exhibit 5-29. Distribution of nameplate generating capacity 5-27
Exhibit 5-30. Cumulative distribution of Phase II Facility year 2000 generating
unit capacity factors by primary fuel type 5-28
Exhibit 5-31. Distribution of Phase II Facility year 2000 generating unit capacity
factors by generating unit prime mover 5-29
Exhibit 5-32. Phase II Facility year 2000 generating unit capacity factors versus
nameplate generating unit capacity 5-30
Exhibit 5-33. Phase II Facility generating unit year 2000 capacity factor versus
year generating unit came online 5-30
Exhibit 5-34. Distribution of Phase II Facility year 2000 total plant capacity
factors by primary fuel type 5-31
Exhibit 5-35. Distribution of Phase II Facility year 2000 total plant capacity
factors by intake waterbody type 5-31
Exhibit 5-36. Phase II Facility year 2000 total plant capacity factor versus total
generating capacity 5-32
Exhibit 5-37. Distribution of capacity utilization 5-33
Exhibit 5-38. Facilities with CUR less than 10 percent 5-34
Exhibit 5-39. Swim speed versus fish length 5-36
Exhibit 5-40. Design Intake Flow (gpm) / MW steam capacity for once-through
power plants over 50 MGD 5-37
Exhibit 5-41. Median water efficiency (water use per MW generated) of power
plants (including CCRS) 5-38
Exhibit 6-1. List of technologies considered 6-2
Exhibit 6-2. Natural draft cooling towers at Chalk Point Generating Station,
Aquasco, MD 6-4
Exhibit 6-3. Mechanical draft cooling towers at Logan Generating Plant,
Swedesboro, NJ 6-5
Exhibit 6-4. Modular cooling tower (image from Phoenix Equipment) 6-6
Exhibit 6-5. Dry cooling tower (image from GEM Equipment) 6-8
IX
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Contents § 316(b) Existing Facilities Final Rule - TDD
Exhibit 6-6. Percent reduction in flow for various cooling system delta Ts 6-9
Exhibit 6-7. Flow reduction at Millstone 6-17
Exhibit 6-8. Examples of seasonal flow reductions 6-18
Exhibit 6-9. Generic CWIS with traveling screens 6-20
Exhibit 6-10. Traveling screen at Eddystone Generating Station, Eddystone, PA 6-21
Exhibit 6-11. Traveling screen diagram 6-21
Exhibit 6-12. Cylindrical wedgewire screen 6-22
Exhibit 6-13. Ristroph and Fletcher basket designs 6-26
Exhibit 6-14. Geiger screen (image from EPRI2007) 6-37
Exhibit 6-15. Hydrolox screen (image from DCN 10-6831) 6-39
Exhibit 6-16. WTP screen (image from Beaudrey) 6-40
Exhibit 6-17. Illustration of fine mesh screen operation and "converts" 6-47
Exhibit 6-18. Gunderboom at Lovett Generating Station (image from
Gunderboom) 6-55
Exhibit 6-19. Velocity cap diagram 6-60
Exhibit 6-20. Velocity caps prior to installation at Seabrook Generating Station
(Seabrook, NH) 6-60
Exhibit 6-21. Graph of Swim Speed versus Body Length 6-67
Exhibit 6-22. Relative Technology Performance for Impingement Mortality
Reduction 6-69
Exhibit 6-23. Relative Technology Performance for Entrainment Reduction 6-70
Exhibit 8-1. Flow Chart for Determining Impingement Mortality Compliant
Intakes Based on Meeting Performance of Modified Ristroph Traveling
Screens 8-7
Exhibit 8-2. Flow Chart for Assigning Technology Cost Modules Based on
Meeting Performance of Modified Ristroph Traveling Screens 8-8
Exhibit 8-3. Number of Model Facility Intakes Assigned Each Compliance
Module 8-10
Exhibit 8-4. Net Construction Downtime for Impingement Mortality Compliance
Technologies 8-12
Exhibit 8-5. Input Data Sources and Assumptions 8-17
Exhibit 8-6. Assumed Height of Traveling Screen Deck Above Mean Water Level.... 8-19
Exhibit 8-7. Cooling Tower Costs for Average Difficulty Retrofit 8-25
Exhibit 8-8. Capital and O&M Cost Factors for Average Difficulty Cooling
Tower Retrofit with 25 percent Plume Abatement 8-25
Exhibit 8-9. Cooling Tower Costs for Difficult Retrofit 8-26
Exhibit 8-10. Ratio of Non-Contact Cooling Water Flow to Total Facility Flow
for Evaluated Manufacturing Facilities With DIF > 100 MGD 8-28
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§ 316(b) Existing Facilities Final Rule - TDD Contents
Exhibit 8-11. Net Construction Downtime for Closed-cycle Retrofit 8-34
Exhibit 8-12. Number of Model Facilities/CWISs Classified as Closed-Cycle 8-37
Exhibit 8-13. Costs Factors for Estimating New Unit Capacity Values 8-39
Exhibit 8-14. Annual New Capacity Potentially Subject to New Unit
Requirement by Cost Category 8-39
Exhibit 8-15. Costs for New Units Based on GPM 8-41
Exhibit 8-16. Costs for New Units Based on Generating Capacity 8-41
Exhibit 8-17. Estimation of DIP Where No DIP Data Exists 8-46
Exhibit 8-18. Cost Equations for Estimating Model Facility Costs of
Impingement Mortality Controls for the IPM Analysis 8-47
Exhibit 8-19. Estimated Technology Service Life 8-48
Exhibit 8-20. Technology Downtime and Service Life for Model Facility Costs of
Impingement Mortality Controls for the IPM Analysis 8-49
Exhibit 8-21. Intakes Costed for Modified Traveling Screens that Include New
Barrier Nets or Existing Other IM Reduction Technologies 8-50
Exhibit 9-1. Reductions in Impingement Mortality and Entrainment Mortality 9-4
Exhibit 9-2. Summary of Primary Options 9-5
Exhibit 10-1. Phase II facilities in non-attainment areas (by pollutant) 10-7
Exhibit 10-2. Phase II facilities in non-attainment areas (by EPA Region) 10-7
Exhibit 11-1. Technologies With Data Considered as Basis of the 12 Month
Percent Impingement Mortality Standard 11-2
Exhibit 11-2. Species Classified as Fragile in Data Otherwise Meeting Data
Selection Criteria 11-3
Exhibit 11-2. Compliant Technologies Not Considered as Candidate for Basis of
12 Month Percent Impingement Mortality Standard 11-5
Exhibit 11-3. Facilities and Data Selected as the Basis of the Impingement
Mortality Standard 11-6
Exhibit 11-4. Geographic Distribution of Facilities Used as the Basis of the
Impingement Mortality Standard 11-7
Exhibit 11-5. Impingement Mortality Data Used As a Basis for the Impingement
Mortality Standard 11-9
Exhibit 11-6. Characteristics of Facilities Used As Basis for Impingement
Mortality Standard 11-11
Exhibit 12-1. Compliance Assessment of Randomly Selected De Minimis Intakes 12-4
Exhibit 12-2. Average Densities (N/m3) of eggs and ichthyoplankton sampled at
a given maximum depth intervals in the Gulf of Mexico 12-5
Exhibit 12-3. Cost Comparison for a 350 MW Plant with Cooling Flow of
200,000 gpm (288 MGD) 12-8
Exhibit 12-4. Impingement and Entrainment Losses Per Unit Flow 12-9
XI
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Contents § 316(b) Existing Facilities Final Rule - TDD
Exhibit 12-5. Changes in Baseline Impingement and Entrainment 12-9
Exhibit 12-6. Map of Non-Attainment Areas for PM10 12-11
Exhibit 12-7. Examples of PM-10 Emissions Estimates Calculations 12-13
XII
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 1: Background
Chapter 1: Background
1.0 Introduction
This chapter provides background information on the development of 316(b) regulations
including the final existing facilities rule. This chapter describes the goal of the final
existing facilities rule and provides an overview of the legislative background, prior
316(b) rulemakings, and associated litigation history leading up to the rulemaking. This
document builds on and updates record support compiled for the Phase I rule, the
remanded 2004 Phase II rule, the Phase III rule, and the proposed existing facilities rule,
including the Technical Development Documents (TDD) for each.
1.1 Purpose of Technical Development Document and Final
Regulation
The purpose of this TDD is to provide record support for the final existing facilities rule
and to describe the methods used by EPA to analyze various options. The goal of the
regulation is to establish national requirements for cooling water intake structures at
existing facilities that implement section 316(b) of the CWA. Section 316(b) of the CWA
provides that any standard established pursuant to section 301 or 306 of the CWA and
applicable to a point source must require that the location, design, construction, and
capacity of cooling water intake structures reflect the best technology available (BTA) for
minimizing adverse environmental impact.
EPA first promulgated regulations to implement section 316(b) in 1976. The U.S. Court
of Appeals for the Fourth Circuit remanded these regulations to EPA which withdrew
them, leaving in place a provision not remanded that directed permitting authorities to
determine BTA for each facility on a case-by-case basis. In 1995, EPA entered into a
consent decree establishing a schedule for taking final action on regulations to implement
section 316(b). Pursuant to a schedule in the amended decree providing for final action
on regulations in three phases, in 2001, EPA published a Phase I rule governing new
facilities. The U.S. Court of Appeals for the Second Circuit, while generally upholding
the rule, rejected the provisions allowing restoration to be used to meet the requirements
of the rule. Riverkeeper, Inc. v. U.S. EPA, 358 F. 3d 174, 181 (2d Cir.2004)
("Riverkeeper I").
In 2004, EPA published the Phase II rule applicable to existing power plants. Following
challenge, the Second Circuit remanded numerous aspects of the rule to the Agency,
including the Agency's decision to reject closed-cycle cooling as BTA. The Agency
made this determination, in part, based on a consideration of incremental costs and
benefits. The Second Circuit concluded that a comparison of the costs and benefits of
closed-cycle cooling was not a proper factor to consider in determining BTA.
Riverkeeper, Inc. v. U.S.EPA, 475 F. 3d 83 (2d Cir. 2007) ("Riverkeeper II"). In 2008, the
U.S, Supreme Court agreed to review the Riverkeeper II decision limited to a single
issue: whether section 316(b) authorizes EPA to balance costs and benefits in 316(b)
rulemaking. In April 2009, in Entergy Corp. v. Riverkeeper Inc., 129 S. Ct. 1498, 68 ERC
1-1
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Chapter 1: Background § 316(b) Existing Facilities Final Rule - TDD
1001 (2009) (40 ER 770, 4/3/09), the Supreme Court ruled that it is permissible under
section 316(b) to consider costs and benefits in determining the best technology available
to minimize adverse environmental impacts. The court left it to EPA's discretion to
decide whether and how to consider costs and benefits in 316(b) actions, including
rulemaking and BPJ determinations. The Supreme Court remanded the rule to the Second
Circuit. Subsequently, EPA asked the Second Circuit to return the rule to the Agency for
further review.
In 2006, EPA published the Phase III rule. The Phase III rule establishes 316(b)
requirements for certain new offshore oil and gas extraction facilities. In addition, EPA
determined that, in the case of electric generators with a design intake flow of less than
50 mgd and existing manufacturing facilities, 316(b) requirements should be established
by NPDES permit Directors on a case-by-case basis using their best professional
judgment. In July 2010, the U. S. Court of Appeals for the Fifth Circuit issued a decision
upholding EPA's rule for new offshore oil and gas extraction facilities. Further, the court
granted the request of EPA and environmental petitioners in the case to remand the
existing facility portion of the rule back to the Agency for further rulemaking.
On April 20, 2011, EPA published the proposed rule for existing facilities, which was in
response to the remand of the Phase II rule and the remand of the existing facilities
portion of the Phase III rule. In addition, EPA also responded to the decision in
Riverkeeper I by proposing to remove from the Phase I new facility rule the restoration-
based compliance alternative and the associated monitoring and demonstration
requirements. On June 11* and 12*, EPA also published two Notices of Data Availability
(NOD A). Today's final rule incorporates all of EPA's experience, with a focus on the
existing facilities rule as the most current and most comprehensive. See Section 1.2
below for a more detailed discussion of the history of EPA's actions to address standards
for cooling water intake structures.
The final rule's requirements reflect the best technology available for minimizing adverse
environmental impact, applicable to the location, design, construction, and capacity of
cooling water intake structures for existing facilities. EPA is addressing existing power
generating facilities and existing manufacturing and industrial facilities in one
proceeding. This final rule applies to all existing power generating facilities and existing
manufacturing and industrial facilities that have the design capacity to withdraw more
than two million gallons per day of cooling water from waters of the United States and
use at least twenty-five (25) percent of the water they withdraw exclusively for cooling
purposes.
1.2 Background
The Federal Water Pollution Control Act, also known as the Clean Water Act (CWA), 33
U.S.C. 1251 et seq., seeks to "restore and maintain the chemical, physical, and biological
integrity of the nation's waters." 33 U.S.C. § 1251(a). Among the goals of the Act is
"wherever attainable, an interim goal of water quality which provides for
the protection and propagation offish, shellfish, and wildlife and provides
for recreation in and on the water..." 33 U.S.C. § 1251(a)(2).
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 1: Background
In furtherance of these objectives, the CWA establishes a comprehensive regulatory
program, key elements of which are (1) a prohibition on the discharge of pollutants from
point sources to waters of the United States, except in compliance with the statute; (2)
authority for EPA or authorized States or Tribes to issue National Pollutant Discharge
Elimination System (NPDES) permits that authorize and regulate the discharge of
pollutants; and (3) requirements for effluent limitations and other conditions in NPDES
permits to implement applicable technology-based effluent limitations guidelines and
standards and applicable State water quality standards.
Section 402 of the CWA authorizes EPA (or an authorized State or Tribe) to issue an
NPDES permit to any person discharging any pollutant or combination of pollutants from
a point source into waters of the United States. Forty-six States and one U.S. territory are
authorized under section 402(b) to administer the NPDES permitting program. NPDES
permits restrict the types and amounts of pollutants, including heat that may be
discharged from various industrial, commercial, and other sources of wastewater. These
permits control the discharge of pollutants by requiring dischargers to meet technology-
based effluent limitations guidelines (ELGs) or new source performance standards
(NSPS) established pursuant to section 301 or section 306. Where such nationally
applicable ELGs or NSPS exist, permit authorities must incorporate them into permit
requirements. Where they do not exist, permit authorities establish effluent limitations
and conditions, reflecting the appropriate level of control (depending on the type of
pollutant) based on the best professional judgment of the permit writer. Limitations based
on these guidelines, standards, or on best professional judgment are known as
technology-based effluent limits. Where technology-based effluent limits are inadequate
to meet applicable State water quality standards, section 301(b)(l)(C) of the Clean Water
Act requires permits to include more stringent limits to meet applicable water quality
standards. NPDES permits also routinely include standard conditions applicable to all
permits, special conditions, and monitoring and reporting requirements. In addition to
these requirements, NPDES permits must contain conditions to implement the
requirements of section 316(b).
Section 510 of the Clean Water Act provides, that except as provided in the Clean Water
Act, nothing shall preclude or deny the right of any State (or political subdivision thereof)
to adopt or enforce any requirement respecting control or abatement of pollution; except
that if a limitation, prohibition or standard of performance is in effect under the Clean
Water Act, such State may not adopt any other limitation, prohibition, or standard of
performance which is less stringent than the limitation, prohibition, or standard of
performance under the Act. EPA interprets this to reserve for the States authority to
implement requirements that are more stringent than the Federal requirements under state
law. PUD No. 1 of Jefferson County v. Washington Dep't of Ecology, 511 U. S. 700, 705
(1994).
Sections 301, 304, and 306 of the CWA require that EPA develop technology-based
effluent limitations guidelines and new source performance standards that are used as the
basis for discharge requirements in wastewater discharge permits. EPA develops these
effluent limitations guidelines and standards for categories of industrial dischargers based
on the pollutants of concern discharged by the industry, the degree of control that can be
attained using various levels of pollution control technology, consideration of various
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Chapter 1: Background § 316(b) Existing Facilities Final Rule - TDD
economic tests appropriate to each level of control, and other factors identified in sections
304 and 306 of the CWA (such as non-water quality environmental impacts including
energy impacts). EPA has promulgated regulations setting effluent limitations guidelines
and standards under sections 301, 304, and 306 of the CWA for more than 56 industries.
See 40 CFR parts 405 through 471. EPA has established effluent limitations guidelines
and standards that apply to most of the industry categories that use cooling water intake
structures (e.g., steam electric power generation, paper and allied products, petroleum
refining, iron and steel manufacturing, and chemicals and allied products).
Section 316(b) states, in full:
Any standard established pursuant to Section 301 or Section 306 of [the
Clean Water] Act and applicable to a point source shall require that the
location, design, construction, and capacity of cooling water intake
structures reflect the best technology available for minimizing adverse
environmental impact.
Section 316(b) addresses the adverse environmental impact caused specifically by the
intake of cooling water, rather than discharges into water. Despite this special focus, the
requirements of section 316(b) remain closely linked to several of the core elements of
the NPDES permit program established under section 402 of the CWA to control
discharges of pollutants into navigable waters. Thus, while effluent limitations apply to
the discharge of pollutants by NPDES-permitted point sources to waters of the United
States, section 316(b) applies to facilities subject to NPDES requirements that also
withdraw water from a water of the United States for cooling and that use a cooling water
intake structure to do so.
The CWA does not describe the factors to be considered in establishing section 316(b)
substantive performance requirements that reflect the "best technology available for
minimizing adverse environmental impact." The most recent guidance in interpreting
316(b) comes from the U.S. Supreme Court's decision in Entergy Corp. v. Riverkeeper,
Inc. As noted, the decision was limited to the single question of whether section 316(b) of
the Clean Water Act authorizes EPA to compare costs and benefits of various
technologies when setting national performance standards for cooling water intake
structures under section 316(b) of the Clean Water Act. In Riverkeeper II, the Second
Circuit rejected EPA's determination that closed-cycle cooling was not BTA because it
could not determine whether EPA had improperly considered costs and benefits in its
316(b) rulemaking. The Supreme Court reversed and remanded the Second Circuit ruling
in a 6-3 opinion authored by Justice Scalia. The Court held that it is reasonable for EPA
to conduct a cost-benefit analysis in setting national performance standards for cooling
water intake structures under section 316(b). The Court held that EPA has the discretion
to consider costs and benefits under section 316(b) but is not required to consider costs
and benefits. The Court's discussion of the language of section 316(b) - section 316(b) is
"unencumbered by specified statutory factors" — and its critique of the Second Circuit's
decision affirms EPA's broader discretion to consider a number of factors in standard
setting under section 316(b). While the Supreme Court's decision is limited to whether or
not EPA may consider one factor (cost/benefit analysis) under section 316(b), the
language also suggests that EPA has wide discretion in considering factors relevant to
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 1: Background
316(b) standard setting. ("It is eminently reasonable to conclude that § 1326V?, silence is
meant to convey nothing more than a refusal to tie the agency's hands as to whether cost-
benefit analysis should be used, and if so to what decree." (emphasis supplied), 129 S.Ct.
1498, 1508 (2009).
Regarding the other factors EPA may consider, section 316(b) cross references sections
301 and 306 of the CWA by requiring that any standards established pursuant to those
sections also must require that the location, design, construction and capacity of intake
structures reflect BTA. Thus, among the factors EPA may use to determine BTA, EPA
may look to similar phrases used elsewhere in the CWA. See Riverkeeper v. EPA, (2nd
Cir. Feb. 3, 2004). Section 306 directs EPA to establish performance standards for new
sources based on the "best available demonstrated control technology" (BADT). 33
U.S.C. 1316(a)(l). In establishing BADT, EPA "shall take into consideration the cost of
achieving such effluent reduction, and any non-water quality environmental impact and
energy requirements." 33 U.S.C. 1316(b)(2)(B). The specific cross-reference in CWA
section 316(b) to CWA section 306 "is an invitation to look to section 306 for guidance
in discerning what factors Congress intended the EPA to consider in determining the
'best technology available'" for new sources.
Similarly, section 301 of the CWA requires EPA to establish standards known as
"effluent limitations" for existing point source discharges in two phases. In the first
phase, applicable to all pollutants, EPA must establish effluent limitations based on the
"best practicable control technology currently available" (BPT). 33 U.S.C.
131 l(b)(l)(A). In establishing BPT, the CWA directs EPA to consider the total cost of
application of technology in relation to the effluent reduction benefits to be achieved
from such application, and shall also take into account the age of the equipment and
facilities involved, the process employed, the engineering aspects of the application of
various types of control techniques, process changes, non-water quality environmental
impact (including energy requirements), and such other factors as [EPA] deems
appropriate. 33 U.S.C. 1314(b)(l)(b).
In the second phase, EPA must establish effluent limitations for conventional pollutants
based on the "best conventional pollution control technology" (BCT), and for toxic
pollutants based on the "best available technology economically achievable" (BAT). 33
U.S.C. 1311(b)(2)(A), (E).
In determining BCT, EPA must consider, among other factors,
"the relationship between the costs of attaining a reduction in effluents and
the effluent reduction benefits derived, and the comparison of the cost and
level of reduction of such pollutants from the discharge from publicly
owned treatment works to the cost and level of reduction of such
pollutants from a class or category of industry source.... and the age of
equipment and facilities involved, the process employed, the engineering
aspects .... of various types of control techniques, process changes, the
cost of achieving such effluent reduction, non-water quality environmental
impacts (including energy requirements), and such other factors as [EPA]
deems appropriate." 33 U.S.C. 1314(b)(4)(B).
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Chapter 1: Background § 316(b) Existing Facilities Final Rule - TDD
In determining BAT, the CWA directs EPA to consider "the age of equipment and
facilities involved, the process employed, the engineering aspects .... of various types of
control techniques, process changes, the cost of achieving such effluent reduction, non-
water quality environmental impacts (including energy requirements), and such other
factors as [EPA] deems appropriate." 33 U.S.C. 1314(b)(2)(B).
Section 316(b) expressly refers to section 301, and the phrase "best technology available"
is very similar to the phrases "best available technology economically achievable " and
"best practicable control technology currently available" in that section. Thus, Section
316(b), section 301(b)(l)(A) -- the BPT provision-- and section 301(b)(l)(B) - the BAT
provision - all include the terms "best," "technology," and "available," but neither BPT
nor BAT goes on to consider minimizing adverse environmental impacts, as BTA does.
See 33 U.S.C. 131 l(b)(l)(A) and (2)(A). These facts, coupled with the brevity of section
316(b) itself, prompts EPA to look to section 301 and, ultimately, section 304 for further
guidance in determining the "best technology available to minimize adverse
environmental impact" of cooling water intake structures for existing facilities.
By the same token, however, there are significant differences between section 316(b) and
sections 301 and 304. See River'keeper, Inc. v. United States Environmental Protection
Agency (2nd Cir. Feb. 3, 2004) ("not every statutory directive contained [in Sections 301
and 306] is applicable" to a section 316(b) rulemaking). Moreover, as the Supreme Court
recognized, while the provisions governing the discharge of toxic pollutants must require
the elimination of discharges if technically and economically achievable, section 316(b)
has the less ambitious goal of "minimizing adverse environmental impact." 129 S.Ct.
1498, 1506. In contrast to the effluent limitations provisions, the object of the "best
technology available" is explicitly articulated by reference to the receiving water: to
minimize adverse environmental impact in the waters from which cooling water is
withdrawn. This difference is reflected in EPA's past practices in implementing sections
301, 304, and 316(b). EPA has established BPT and BAT effluent limitations guidelines
and NSPS based on the efficacy of one or more technologies to reduce pollutants in
wastewater in relation to their costs without necessarily considering the impact on the
receiving waters. This contrasts to 316(b) requirements, where EPA has previously
considered the costs of technologies in relation to the benefits of minimizing adverse
environmental impact in establishing 316(b) limits, which historically has been done on a
case-by case basis. In Re Public Service Co. of New Hampshire, 10 ERC 1257 (June 17,
1977); In Re Public Service Co. of New Hampshire, 1 EAD 455 (Aug. 4, 1978); Seacoast
Anti-Pollution League v. Costle, 597 F. 2d 306 (1st Cir. 1979) EPA concluded that,
because both section 301 and 306 are expressly cross-referenced in section 316(b), EPA
reasonably interpreted section 316(b) as authorizing consideration of the same factors,
including costs, as in those sections. EPA interpreted "best technology available" to mean
the best technology available at an "economically practicable" cost. This approach
squared with the limited legislative history of section 316(b) which suggested the BTA
was to be based on technology whose costs were "economically practicable." In debate
on section 316(b), one legislator explained that "[t]he reference here to 'best technology
available' is intended to be interpreted to mean the best technology available
commercially at an economically practicable cost." 118 Cong. Rec. 33,762 (1972)
(statement of Rep. Clausen) (emphasis added).
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 1: Background
For EPA's initial Phase II rulemaking, as it had during 30 years of BPJ section 316(b)
permitting, EPA therefore interpreted CWA section 316(b) as authorizing EPA to
consider not only the costs of technologies but also their effects on the water from which
the cooling water is withdrawn.
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 2: Summary of Data Collection
Chapter 2: Summary of Data Collection Activities
2.0 Introduction
In developing the final rule, EPA used previously collected data from the Phase I, 2004
Phase II, and Phase III rulemakings in combination with newly collected data and
information. This chapter first provides information on major data collection activities
from the previous rulemakings and then provides summaries of information obtained
through more recent data collection activities.
2.1 Primary Data Sourced from Previous 316(b) Rulemakings
This section summarizes the major data collection activities conducted during
development of the Phase I, 2004 Phase II, and Phase III rulemakings that EPA also
considered in developing this final rule. For additional, more detailed information on
these previous activities, see the Phase I proposed rule (65 FR 49070), Phase INODA
(66 FR 28853), Phase II proposal (67 FR 17131), Phase II NODA (68 FR 13524), Phase
III proposal (69 FR 68457), Phase III NODA (70 FR 71057), Phase III final (71 FR
35018), and Phase III final TDD (Chapter 3). Also see the proposed rule for existing
facilities (76 FR 22174), the two NOD As (77 FR 34315 and 77 FR 34927), and the
existing facility rule proposed TDD.
2.1.1 Survey Questionnaires
Industry characterization data, including facility-specific technical and financial
information, for the existing facility rule and EPA's Phase I, 2004 Phase II, and Phase III
rulemakings was collected through an industry-wide survey conducted in 2000.l This
information was fundamental to EPA's development of its previous rulemakings and is
similarly fundamental to the existing facilities rule. EPA has relied on the previously
collected technical (e.g., cooling water system data and cooling water intake
configuration specifications and intake flow rates) and financial information.2'3
Two types of surveys were issued: detailed questionnaires (DQ) and short technical
questionnaires (STQ). Detailed questionnaires were longer and requested more specific
information about technologies, plant operations, and other characteristics. Short
technical questionnaires were developed as a way to statistically sample a larger number
of facilities while maintaining a manageable burden on the industry respondents; these
surveys contained far less detailed information.
1 For the Phase III rule, EPA also issued industry questionnaires to offshore industries (see 69 FR 68458).
2 Specific details about the questions are found in EPA's Information Collection Request (DCN 3- 3084-
R2 in Docket W-00-03) and in the questionnaires (see DCN 3-0030 and 3- 0031 in Docket W-00-03 and
the Docket for the proposed existing facilities rule); these documents are also available on EPA's web site
(http ://water. epa. gov/lawsre gs/laws guidance/cwa/316b/index.cfm)
3 EPA did update some of the financial information. For a discussion of financial data used, see the EA.
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Chapter 2: Summary of Data Collection § 316(b) Existing Facilities Final Rule - TDD
2.1.2 Technology Efficacy Data
For the Phase II rule, EPA compiled a database of cooling water intake structure
technology performance information otherwise known as the Technology Efficacy
Database (TED) (DCN 6-5000 and FDMS Document ID EPA-HQ-OW-2002-0049-
1595). The Technology Efficacy Database was the result of an extensive literature search
supplemented by information obtained through discussions with State and EPA regional
staff, and meetings with nongovernmental organizations that had conducted national or
regional data collection efforts (e.g., Electric Power Research Institute (EPRI) and
Tennessee Valley Authority). EPA's goal in developing this database was to collect
information and data to evaluate the performance of various impingement and
entrainment control technologies. The resulting database contains over 150 records from
over 90 documents that include narrative descriptions of biological sampling information
and efficacies for a range of impingement and entrainment minimization technologies.
See Chapter 4 of the TDD for the 2004 Phase II Final rule for a complete description of
this database. As described in Section 2.2.3 below, EPA updated and supplemented this
database with new information and new analyses for today's final rule.
2.1.3 Existing Data Sources
In developing 316(b) regulations, EPA used existing data sources, where available and
applicable. This includes information collected by other Federal agencies as well as data
compiled by private companies. Additional details are found in the 2002 proposed Phase
II rule at 67 FR17131, but the sources contacted include:
• Federal Energy Regulatory Commission (FERC);
• Energy Information Administration (EIA);
• Rural Utility Service (RUS);
• U.S. Nuclear Regulatory Commission (NRC);
• Utility Data Institute;
• NEWGen database;
• Electric Power Research Institute (EPRI); and
• Edison Electric Institute (EEI).
2.1.4 Public Participation Activities
Historically, EPA has worked extensively with stakeholders from industry, public interest
groups, State agencies, and other Federal agencies in the development of previous 316(b)
rulemakings, including numerous meetings with individual stakeholder groups. These
public participation activities focused on various section 316(b) issues including biology,
technology, and implementation issues. For example, EPA has conducted public
meetings focused on technology, cost and mitigation issues, a technical symposium
sponsored by EPRI and a symposium on cooling water intake structure technologies. See
the 2002 proposed Phase II rule (68 FR 17127) for a discussion of these and other public
participation activities.
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 2: Summary of Data Collection
EPA has also issued twelve Federal Register notices regarding the 316(b) regulation
development process.4 As a result, EPA has received over 1750 public comments from
environmental groups, industry associations, facility owners, State and Federal agencies,
and private citizens.
See below and the preamble to the final rule for more information on data provided by
stakeholders and EPA's outreach efforts.
2.2 New Data Collected
For the existing facilities rule, EPA supplemented its previous data collection activities.
EPA collected updated information on various aspects of the rulemaking. However, in an
effort to better inform its BTA determination, EPA's main focus was on the performance
of impingement and entrainment technologies.
2.2.1 Site Visits
As documented in the 2004 Phase II rule, EPA conducted site visits to 22 power plants in
developing the 2004 rule. See 67 FR 17134. Since 2007, EPA has conducted over 50 site
visits to power plants and manufacturing sites. The purpose of these visits was to: gather
information on the intake technologies and cooling water systems in place at a wide
variety existing facilities; better understand how the site-specific characteristics of each
facility affect the selection and performance of these systems; gather data on the
performance of technologies and affected biological resources; and to solicit perspectives
from industry representatives.
While visiting certain sites, EPA also collected information on 7 additional facilities that
staff did not physically visit; usually, these were other facilities that were owned by the
parent company of a site visited by EPA. EPA further met with representatives of other
companies or owners of specific power plant or manufacturing sites at EPA Headquarters
in Washington DC.
In general, EPA visited a wide variety of sites representative of the industries and
facilities subject to the existing facility rule. Copies of the site visit reports (which
provide an overall facility description as well as detailed information on electricity
generation, the facility's cooling water intake structure and associated fish protection
and/or flow reduction technologies, impingement and/or entrainment sampling and
associated data, and a discussion of the possible application of cooling towers) for each
site were provided in the docket for the proposed existing facility rule (one was also
provided in the June 12, 2012 NODA record). Where possible, EPA also made these
reports publicly available well before publication of the proposed rule. A list of the
facilities visited by EPA is provided in Exhibit 2-1 below; Exhibits 2-2 and 2-3 show the
other facilities for which EPA was provided site-specific data and a geographic
4 See 65 FR 49060, 66 FR 28853, 66 FR 65256, 67 FR 17122, 68 FR 13522, 69 FR 41576, 69 FR 68444,
70 FR 71057, 71 FR 35006, 76 FR 22174, 77 FR 34315, and 77 FR 34927. Also see the EA and BA for a
discussion of the Federal Register notices for economics-related issues.
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Chapter 2: Summary of Data Collection
§ 316(b) Existing Facilities Final Rule - TDD
representation of facilities visited by EPA as well as facilities for which EPA collected
site-specific technical and engineering information.
Exhibit 2-1. Facilities visited by EPA
Facility Name
El Segundo
Haynes
San Onofre
Scattergood
Valero (Delaware City)
Big Bend
St. Lucie
Harlee Branch
McDonough
Council Bluffs
Crawford
Arcelor Mittal (Indiana Harbor)
Cargill (Hammond)
US Steel (Gary)
Nearman Creek
Quindaro
Dow (Louisiana Operations/Plaquemine)
Dow (St Charles)
Chalk Point
Labadie
Lake Road
Meramec
Brunswick
Nebraska City
North Omaha
Seabrook
Linden
Logan
Mercer
Salem
Beaver Falls
Danskammer
East River
Ginna
Nine Mile Point
Oswego
Wheelabrator Westchester
Eddystone
Sunoco (Marcus Hook)
Sunoco (Philadelphia)
Canadys
Wateree
Williams
Barney Davis
Birchwood
Chesterfield
North Anna
Possum Point
Potomac
Surry
State
CA
CA
CA
CA
DE
FL
FL
GA
GA
IA
IL
IN
IN
IN
KS
KS
LA
LA
MD
MO
MO
MO
NC
NE
NE
NH
NJ
NJ
NJ
NJ
NY
NY
NY
NY
NY
NY
NY
PA
PA
PA
SC
SC
SC
TX
VA
VA
VA
VA
VA
VA
Industry
Generator
Generator
Generator
Generator
Manufacturer
Generator
Generator
Generator
Generator
Generator
Generator
Manufacturer
Manufacturer
Manufacturer
Generator
Generator
Manufacturer
Manufacturer
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Manufacturer
Manufacturer
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Date Of Visit
9/1/2009
9/2/2009
9/2/2009
8/31/2009
7/15/2009
3/27/2008
3/26/2008
2/11/2009
2/11/2009
3/2/2009
8/4/2009
8/3/2009
8/3/2009
8/4/2009
3/3/2009
3/3/2009
1/12/2010
1/13/2010
12/3/2007
3/4/2009
3/3/2009
3/4/2009
1/28/2008
3/2/2009
3/2/2009
4/17/2008
5/26/2010
1/22/2008
5/26/2010
1/22/2008
4/1/2008
4/16/2008
4/15/2008
4/3/2008
4/2/2008
4/2/2008
4/16/2008
1/23/2008
7/14/2009
7/14/2009
2/10/2009
2/10/2009
2/9/2009
3/3/2008
7/28/2011
3/10/2009
4/28/2009
3/10/2009
12/3/2007
1/28/2008
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 2: Summary of Data Collection
Exhibit 2-2. Facilities that provided data to EPA
Facility Name
Alamitos
Contra Costa
Diablo Canyon
Diablo Canyon
Encina
Harbor
Huntington Beach
Mandalay
Morro Bay
Moss Landing
Ormond Beach
Pittsburg
Potrero
Redondo Beach
South Bay
Yates
Fisk
Winnetka
Brayton Point
General Electric (Lynn)
Callaway
Hawthorn
latan
Sibley
Sioux
Georgia Pacific
Cooper
Fort Calhoun
Hope Creek
Oyster Creek
Brooklyn Navy Yard
Indian Point
Elm Road
Oak Creek
State
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
CA
GA
IL
IL
MA
MA
MO
MO
MO
MO
MO
multiple
NE
NE
NJ
NJ
NY
NY
Wl
Wl
Industry
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Manufacturer
Generator
Generator
Generator
Generator
Generator
Manufacturer
Generator
Generator
Generator
Generator
Generator
Generator
Generator
Generator
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Chapter 2: Summary of Data Collection
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 2-3. Site visit locations and locations of other site-specific data collected
Legend
• EPA Site Visit
• Other data collection
• Secondary site data collected during site visits
EPA used a wide variety of criteria in selecting the sites to visit, including the following
factors:
• Industry sector: In 2007, EPA met with several trade associations to discuss data
and information sources that would be useful to EPA as it updated analyses. EPA
solicited industry recommendations for criteria for selecting sites, as well as
suggestions for specific sites. Among generators, EPA visited facilities owned by
utilities, non-utilities, and municipalities. For manufacturers, EPA visited steel
mills, petroleum refineries, chemical manufacturers, and a food processing
facility.5
• Facility location: EPA visited facilities in 8 EPA Regions and 20 States.
Facilities were located on all types of waterbodies (ocean, estuary/tidal river,
lake/reservoir, Great Lake and freshwater river). EPA also visited facilities on
major waterbodies, such as the Missouri/Mississippi Rivers, the Gulf of Mexico,
the Chesapeake Bay, and both the Pacific and Atlantic Oceans.
• Intake technology: Selected sites employed a wide range of intake technologies,
including coarse and fine mesh traveling screens, Ristroph traveling screens,
coarse and fine mesh wedgewire screens, offshore velocity caps, and barrier nets.
5 EPA was unable to schedule a visit to a pulp and paper facility, but based on the Agency's experience
with other regulatory activities (including the Pulp and Paper Effluent Limitations Guideline) has found
that this industry sector is not remarkably different from other manufacturers in terms of cooling water
intake structures. EPA also met with Georgia Pacific and the American Pulp and Paper Association to
better understand the use of cooling water and cooling water intake structures for this industry sector.
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 2: Summary of Data Collection
Sites also employed a variety of intake configurations, including shoreline,
offshore, and intake canals.
• Cooling system technology: Most facilities visited employ once-through cooling,
but EPA also visited multiple sites with closed-cycle cooling systems. Some
facilities were designed and constructed as closed-cycle systems, while other sites
retrofitted to closed-cycle cooling; some sites used combination cooling systems.
EPA also visited sites with helper cooling towers.
• Logistics: Proximity to EPA Headquarters was a cost-effective way for multiple
EPA staff to attend site visits. For non-local travel, proximity of sites to one
another enabled clustered site visits, reducing travel costs and maximizing staff
time onsite.
• Biological data: Most facilities were selected because they had conducted some
form of performance study (impingement or entrainment) in recent years.
• Fuel or generation type: Selected sites used a variety of fuel types (coal, natural
gas, nuclear, municipal waste). Most generated power through steam generation,
but EPA also visited several combined cycle facilities.
• Facility size: EPA visited sites of all sizes, with a wide range of generating
capacity (MW), intake flow (mgd), and land area. Additionally, EPA visited sites
in rural areas, industrial areas, and in highly urbanized environments.
In summary, EPA learned the following from the site visits:
• A majority of facilities use coarse mesh screens. However, the screens are
principally used to protect the facility from debris; as such facilities do not always
optimize operation of the screens to protect fish;
• Costs are paramount to facility owners, as any costs could potentially impact
planning and business decisions;
• While site-specific characteristics may set some facilities apart, most facilities
(including manufacturers) were found to be very similar in how they use cooling
water, how the intake technologies were selected and constructed, and challenges
facilities faced in operating CWIS technologies;
• Long-term planning is important to facilities to maintain reliable energy supplies
(issues such as repowering, air rules, increased energy demand, control of
greenhouse gas (GHG) emissions, and local transmission issues have long-term
implications);
• Closed-cycle cooling, while potentially expensive for some sites, is technically
feasible at most sites;
• Some manufacturing facilities may use cooling water for contact cooling (such as
quench water). Contact cooling is rarely observed at power plants.
• Manufacturers have different opportunities to reduce and reuse cooling water. In
some cases, manufacturers have conducted water and energy audits that reduced
total water withdrawals by more than half.
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During the site visits, EPA collected current facility information including power
generation, capacity, and fuel source; permit status; cooling water usage; and cooling
water intake structure and IM&E technologies and controls (including design, operation,
and installation and operational cost information, where available). Through the site
visits, EPA gained a more thorough understanding of the operation of the various EVI&E
technologies and controls including challenges, or lack thereof, and efficacy. EPA also
gained more detailed information on any EVI&E performance studies at each site, and,
ultimately, the performance data. EPA additionally obtained information on the
application of the suspended Phase II rulemaking. For example, EPA requested
information on how each facility planned to comply with the suspended 2004 rule, and
what challenges might have resulted from implementation of the suspended rule at each
facility. Finally, EPA also gained a better understanding of the possible application of
closed-cycle cooling at each facility. As a result of these site visits, EPA gained valuable
information covering a wide range of topics. Several facilities provided National
Pollutant Discharge Elimination System (NPDES) permit application data originally
intended for submission under the 2004 Phase II rule. These studies typically included
Proposals for Information Collection as well as portions of Comprehensive
Demonstration Studies. Several facilities also provided technology efficacy data or
impingement and entrainment data. Some provided EVI&E feasibility studies as well.
Following each visit, EPA prepared a site visit report. These reports document the
information EPA collected through each site visit and its discussions with facility
representatives. Each facility was given the opportunity to review and comment on these
reports. Where the information is not claimed to be confidential, these reports are
available in the record.
EPA also visited Alden Laboratories in Holden, Massachusetts.
2.2.2 Data Provided to EPA by Industrial, Trade, Consulting,
Scientific or Environmental Organizations or by the General Public
EPA has continued to work with various stakeholders in developing the existing facilities
rule. Through these interactions, EPA has received additional data and information
including, but not limited to, the following: technology efficacy data, operating
information, cost information, feasibility, and non-water quality related impact
information.
2.2.2.1 EPRI and Industry
EPA met with representatives from EPRI and industry on topics ranging from the
feasibility and cost of installing cooling towers at certain facilities, current studies of
impingement on the Ohio River, and the latest advancements in fish protection
technologies for traveling screens. Alden Laboratories also participated in some of these
meetings and provided a status report on the latest advancements in fish protection at
cooling water intake structures. EPA reviewed over 40 EPRI or EPRI-funded studies
dated between 1985-2008, and multiple studies since the publication of the 2004 Phase II
rule, including:
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• Fish Protection at Cooling Water Intakes: A Technical Reference Manual (2007)
(DCN 10-6813)
• Net Environmental and Social Effects of Retrofitting Power Plants with Once-
Through Cooling to Closed-Cycle Cooling (2008) (DCN 10-6927)
• Beaudrey Water Intake Protection (WIP) Screen Pilot-Scale Impingement
Survival Study (2009) (DCN 10-6810)
• Comparison of Alternate Cooling Technologies for U.S. Power Plants: Economic,
Environmental, and Other Tradeoffs (2004) (DCN 10-6961)
• Laboratory Evaluation of an Aquatic Filter Barrier for Protecting Early Life
Stages of Fish (2004) (DCN 10-6815)
• Field evaluation of wedgewire screens for protecting early life stages at cooling
water intake structures: Chesapeake Bay studies (2006) (DCN 10-6806)
• Laboratory evaluation of modified Ristroph traveling screens for protecting fish at
cooling water intakes (2006) (DCN 10-6801)
• Design considerations and specifications for fish barrier net deployment at
cooling water intake structures (2006) (DCN 10-6804)
• Laboratory evaluation of fine-mesh traveling water screens for protecting early
life stages offish at cooling water intakes (2008) (DCN 10-6802)
• Latent impingement mortality assessment of the Geiger Multi-Disc screening
system at Potomac River Generating Station (2007) (DCN 10-6814)
• The role of temperature and nutritional status in impingement of clupeid fish
species (2008) (DCN 10-6970)
• Cooling Water Intake Structure Area-of-Influence Evaluations for Ohio River
Ecological Research Program Facilities (2007) (DCN 10-6971)
• Closed-Cycle Cooling System Retrofit Study: Capital and Performance Cost
Estimates (2011) (DCN 12-6807 )
• Seasonal Patterns of Fish Entrainment for Regional U.S. Electric Generating
Facilities (2011) (DCN 12-6892)
• Fish Life History Parameter Values for Equivalent Adult and Production
Foregone Models: Comprehensive Update (2012) (DCN 12-6981)
• Effects of Fouling and Debris on Larval Fish within a Fish Return System (2012)
(DCN 12-6801)
• Field Evaluation of Debris Handling and Sediment Clogging of 2.0 mm Fine-
mesh Traveling Water Screen at the Hawthorn Power Plant, Missouri River,
Kansas City, MO (2012) (DCN 12-6825)
• Full-Time/Seasonal Closed-cycle Cooling: Cost and Performance Comparisons
(2012)(12-6945)
Materials from some of these meetings (e.g., PowerPoint presentations and demonstration
movies) are available at DCNs 10-6816 to 10-6828.
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2.2.2.2 Vendors
EPA also contacted cooling water intake structure technology vendors to investigate the
use of several new technologies for potential application at existing facilities. EPA
contacted or received detailed data from the following technology vendors:
• Beaudrey screens (DCN 10-6606)
• Hydrolox screens (DCN 10-6807)
• Passavant (Geiger) screens (DCNs 10-6601A and B)
• Hendricks screens (DCNs 10-6601C and D)
• EEVICO screens
• Agreco (modular cooling towers) (DCNs 10-6647 and 6677)
• Blue Stream Services (modular cooling towers) (DCN 10-6677)
• EEA (substratum intakes) (DCN 10-6609)
• Gunderboom
• Sontek (acoustic velocimeters)
Vendors provided information on design, operation, and efficacy of these technologies as
well as capital and O&M costs. See the record for the existing facilities rule for this
information.
2.2.3 Updated Technology Information
As discussed in Section 2.1.2 and in the 2002 proposed Phase II rule (68 FR 13538-
13539), EPA previously developed a Technology Efficacy Database in an effort to
document and assess the performance of various technologies and operational measures
(other than closed-cycle cooling6) designed to minimize the impacts of cooling water
withdrawals (see DCN 6-5000 in the docket for the 2004 Phase II rule). EPA has since
created an updated performance database for modified traveling screens. In creating the
updated database, EPA's objective was to review the methods used to generate data in
these studies and to combine relevant data across studies in order to produce statistical
estimates of the overall performance of the technology. See DCN 12-5400 in the final
rule record for this database.
In developing the updated database, EPA considered data from over 473 documents. This
includes documents previously contained in EPA's 316(b) rulemaking records as well as
new documents obtained during development of the existing facilities rule. Some of the
documents are compilations of multiple studies, such as, EPRI's 2007 Fish Protection at
Cooling Water Intakes: A Technical Reference Manual (DCN 10-6813), which includes
results of over 100 studies. Others are facility-specific studies, or describe the results of
research laboratory experiments conducted in a controlled setting. These documents
contain information on the operation or performance of various forms and applications of
6 EPA developed this database to evaluate possible BTA limitations for intake-based technologies. EPA did
not include closed-cycle cooling in this database because that technology operates through a reduction in
flow, creating a different set of evaluation criteria.
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these technologies, typically at a specific facility or controlled setting. The studies
presented in these documents were performed by owners of facilities with cooling water
intake structures, organizations that represent utilities and the electric power industry, and
other research organizations.
To address EPA's objectives of bringing information from these documents together to
better assess technology performance across different technology categories, EPA
obtained and reviewed these documents for the presence of relevant data. Not all
documents fulfilled this objective. While a document might present data that were
acceptable for use in meeting the document's original objectives, this does not
necessarily imply that these data will meet EPA's current objective to combine data
across multiple sources to better assess performance of the different technology
categories. Thus, it was necessary to establish some general criteria for accepting data
from the documents:
• The data must be associated with technologies for minimizing impingement
mortality or entrainment that are currently viable (as recognized by EPA) for use
by industries with cooling water intake structures that are (or will be) subject to
section 316(b) regulation.
• The data must represent a quantitative measure (e.g., counts, densities, or
percentages) that is related to the impingement mortality or entrainment of some
life form of aquatic organisms within cooling water intake structures under the
given technology.
For studies meeting the above criteria, EPA populated an Excel database. Within this
database, each document was distinguished by a unique document ID. The performance
study database consisted of two primary data tables:
• A table containing specific information on a particular study, such as the
document and study IDs, facility name, date of study, data classification -
(e.g., impingement mortality, entrainment), technology category, technology
description, survival holding times, and other test conditions when specified (e.g.,
mesh size, intake velocity, conditions when the technology is in place).
• A table containing the reported performance data for a given study. Each entry in
this table contains one or more performance measures for a particular species
along with other factors when they were specified (e.g., dates or seasons of data
collection, elapsed time to mortality, number impinged, number or percent dead).
EPA used this database to develop performance estimates for certain intake technologies,
and to compare the national performance levels for various impingement mortality and
entrainment technologies. The screening criteria, methodology, and subsequent statistical
analyses conducted to develop national performance standards are discussed in detail in
Chapter 11 of this TDD.
2.2.4 Other Resources
EPA also collected information on cooling water system and cooling water intake
structure-related topics from a variety of other sources.
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2.2.4.1 State Cooling Water Policies
In recent years, several states have developed policies or regulations regarding cooling
water use. EPA did not participate directly in the development of any of these state
activities, but did closely monitor their progress. These State programs are summarized
below.
California
California's Ocean Protection Council (OPC) adopted the April 20, 2006 resolution
called Regarding the Use of Once-Through Cooling Technologies in Coastal Waters
(2006 Resolution, DCN 10-6963) which urged State agencies to "implement the most
protective controls to achieve a 90-95 percent reduction in [impingement and
entrainment] impacts" and analyze the costs and constraints involved with the conversion
of once-through cooling systems to an alternative technology. In February 2008, OPC
completed a study entitled, California's Coastal Power Plants: Alternative Cooling
System Analysis, (DCN 10-6964) which evaluates the feasibility of retrofitting coastal
facilities to closed-cycle cooling towers to mitigate impingement and entrainment
impacts at these sites. EPA reviewed this study to identify site-specific considerations
involved in cooling tower retrofits.
California adopted its final Policy on the Use of Coastal and Estuarine Waters for Power
Plant Cooling on May 4, 2010. (See
http://www.waterboards.ca.gov/water_issues/programs/ocean/cwa316/ for more
information). Per the State website, the Policy "establishes technology-based standards to
implement Federal Clean Water Act section 316(b) and reduce the harmful effects
associated with cooling water intake structures on marine and estuarine life. The Policy
will apply to the 19 existing power plants (including two nuclear plants) that currently
have the ability to withdraw over 15 billion gallons per day from the State's coastal and
estuarine waters using a single-pass system, also known as once-through cooling." The
Policy requires that existing facilities reduce their intake flow to a level commensurate
with a wet closed-cycle system; California established a 93 percent reduction in design
flow as the minimum flow reduction, in addition to limiting intake velocities to 0.5 feet
per second (fps).7
California also proposed an amendment to the final Policy to extend the implementation
schedule for certain facilities that are planning to undergo repowering projects. The State
solicited comments, held public meetings, and adopted the amended policy on July 19,
2011. The State is also considering additional minor amendments to the policy, as
described at their June 18, 2013 meeting.
7 The Policy also contains a Track 2 that permits facilities to demonstrate that compliance with Track 1
(described above) is not feasible; these facilities must reduce impingement mortality and entrainment to at
least 90 percent of the level achievable by compliance with Track 1.
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Delaware
In March 2009, Delaware's House of Representatives introduced House Concurrent
o
Resolution No. 7 (HCR 7) ; the resolution urges the Delaware Department of Natural
Resources and Environmental Control (DNREC) to "declare that "Closed-cycle" cooling
systems constitute the best technology available for water cooling intake structures" and
"to require that all facilities that operate in Delaware waters and that use cooling water
intake structures to adopt "Closed-cycle" cooling systems as quickly as possible." The
resolution also notes the biological impacts associated with once-through cooling. The
resolution was adopted (as amended) by the State Senate and the State House in June
2009. At the time of publication of the final rule, Delaware had not yet enacted a State
regulation, but several facilities had made strides in reducing cooling water flows. A
DNREC permit fact sheet9 noted that the State's largest power plant (Indian River,
located in Millsboro) is closing all three generating units that employ once-through
cooling,10 leaving Indian River with only a closed-cycle cooling system for Unit 4.
During EPA's site visit to the Valero refinery in Delaware City, facility representatives
noted that their upcoming NPDES permit would require a substantial flow reduction.n
New York
In July 10, 2011 New York issued a policy that would require a reduction in impingement
and entrainment mortality to a level equivalent to closed-cycle cooling at all existing
facilities.12 The policy does not specifically require a reduction in cooling water flow,
however, noting that flow is but one of several alternatives. New York also requires all
new power plants to employ dry cooling systems, which reduce water withdrawals even
further than wet cooling towers.
2.2.4.2 Individual NPDES Permit Renewals
In addition to state-wide cooling water policies, some recent individual NPDES permits
have incorporated requirements for significant reductions in cooling water flow. The
best-known example is Brayton Point in Somerset, Massachusetts. EPA Region I (which
develops NPDES permits for several non-delegated New England states) issued a final
NPDES permit in October 2003 that required a reduction in cooling water intake flow
8 See
http://legis.delaware.gov/LIS/LIS145.NSF/93487d394bc01014882569a4007a4cb7/674b902d7832ddd7852
57583005af947?OpenDocument.
9 See http://www.wr.dnrec.delaware.gov/SiteCollectionDocuments/IRGS%20FactSheet 20100908.pdf.
10 In December 2004, EPA Region III developed a Total Maximum Daily Load (TMDL) for temperature in
the Indian River. The Indian River power plant is the only significant discharger to the receiving stream.
See http://www.epa.gov/waters/tmdldocs/IndianRiveEstablish.pdf and
http://www.epa.gov/waters/tmdldocs/DE/IndianRiverEstablish Report.pdf.
11 See DCN 10-6553. The facility closed soon after the site visit, but was purchased by another firm and has
since reopened. As an NPDES condition for the renewed operations at the facility, DNREC has included a
requirement to reduce its intake flow by 33 percent by the end of 2013. See
http://www.dnrec.delaware.gov/News/Pages/DNREC-issues-air-permit-to-restart-cooling-tower-at-
Delaware-City-Refinery-.aspx.
12 NYDEC Policy CP-#52 / Best Technology Available (BTA) for Cooling Water Intake Structures. See:
http://www.dec.nv.gov/docs/fish marine pdf/btapolicvfinal.pdf
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and thermal discharges of approximately 95 percent.13 Following several years of appeals
and litigation, the facility agreed in December 2007 to implement the requirements of the
permit and is currently constructing two natural draft cooling towers at the facility.
EPA also visited a number of sites that had retrofitted to closed-cycle cooling for reasons
other than solely section 316(b) requirements:
• McDonough (GA), Yates (GA), Canadys (SC) and Wateree (SC) converted all
generating units to closed-cycle cooling primarily to reduce thermal discharges.
(SeeDCNs 10-6536, 10-6538, 10-6535, and 10-6534, respectively.)
• Nearman Creek (KS) converted its generating units to reduce the need for cooling
water at times of the year when the source water level is low. (See DCN 10-
6524.)
• Linden (NJ) constructed several new combined cycle units to replace retiring
fossil units and uses grey water from a nearby treatment plant for its makeup
water. (See DCN 10-6557.)
While the reasoning for some retrofits may not explicitly include consideration of 316(b),
flow reduction is clearly an issue in the forefront of permitting and operational decisions
at many facilities. Even in cases where 316(b) was not a consideration, the benefits to
aquatic communities are realized nonetheless.
2.2.4.3 International Cooling Water Policy
EPA sought information on how other nations address the impacts from cooling water
withdrawals. (See, e.g., DCNs 10-6620 and 6621.) In general, EPA found that many
countries lack an overarching regulatory structure analogous to section 316(b), so efforts
to address impacts from cooling water intake structures tend to be somewhat inconsistent.
Some countries address the issue on a facility-by-facility basis, while others may make
broader conclusions based on facility location. EPA's research did indicate a distribution
of once-through and closed-cycle cooling systems similar to that found in the U.S. Lastly,
EPA collected a European Union policy on cooling systems (see DCN 10-6846), which
generally advocated that plant efficiency should be the primary decision criterion in
determining the proper cooling system.
2.2.4.4 EPA's 1974 Steam Electric Effluent Limitation Guideline
EPA also reviewed its 1974 ELG for steam electric generators, as this was the Agency's
first attempt at regulating cooling water withdrawals. In the 1974 final ELG (see 39 FR
36186), any existing electric generator built after 1970 with a capacity greater than 500
MW or any generating unit built after 1974 would have been required to retrofit to
closed-cycle cooling; all new units were to be subject to the same standard. EPA's
rationale at the time was that these facilities were relatively new, operated as baseload
facilities, and would be in service for an extended period, thereby justifying the costs to
retrofit. EPA considered many of the same factors in the ELG that it did in developing
13 See http://www.epa.gov/ne/bravtonpoint/index.html.
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the existing facilities rule. The rule was remanded on administrative grounds and the
subsequent revised ELG (see 47 FR 52290) was silent on cooling water withdrawals and
cooling system types.
2.2.5 Implementation Experience
Following promulgation of the 2004 Phase II rule, States and EPA Regions began to
implement the rule. During that time, EPA worked to assist States in understanding the
rule, develop guidance materials, and support the review of the documentation of the new
requirements. As a result, EPA became aware of certain elements of the 2004 rule that
had become particularly troublesome to implement; as a result, EPA has considered these
challenges and crafted a regulatory framework that the Agency concludes is simpler for
all stakeholders to understand and implement.
2.2.5.1 Calculation Baseline
The 2004 Phase II rule required that facilities reduce impingement mortality and
entrainment from the calculation baseline. The calculation baseline was intended to
represent a "typical" Phase II facility and outlined a configuration for a typical CWIS
(see 69 FR 41590). EPA defined the calculation baseline as follows:
"an estimate of impingement mortality and entrainment that would occur
at your site assuming that: the cooling water system has been designed as
a once-through system; the opening of the cooling water intake structure is
located at, and the face of the standard 3/8 inch mesh traveling screen is
oriented parallel to, the shoreline near the surface of the source waterbody;
and the baseline practices, procedures, and structural configuration are
those that [a] facility would maintain in the absence of any structural or
operational controls, including flow or velocity reductions, implemented
in whole or in part for the purposes or reducing impingement mortality
and entrainment."
In doing so, a facility that had undertaken efforts to reduce impingement and entrainment
impacts (e.g., by installing a fine mesh screen or reducing intake flow) would be able to
"take credit" for its past efforts and only be required to incrementally reduce
impingement mortality or entrainment to meet the performance standards.
In practice, both permittees and regulatory agencies encountered difficulty with the
calculation baseline, specifically how a facility should determine what the baseline
represented and how a particular facility's site-specific configuration or operations
compared to the calculation baseline. For facilities whose site configuration conforms to
the calculation baseline, it was relatively easy to determine impingement mortality and
entrainment at the conditions representing calculation baseline. However, for facilities
that have a different configuration, estimating a hypothetical calculation baseline could
be difficult. For example, facilities with intake configuration that differed significantly
from the calculation baseline (e.g., a submerged offshore intake) were unsure as to how
to translate their biological and technological data to represent a shoreline CWIS.
Oftentimes facilities encountered difficulty in determining the appropriate location for
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monitoring to take place. Other facilities were unsure as to how to take credit for retired
generating units and other flow reductions practices. In site visits, EPA learned that
facilities with little or no historical biological data encountered a particularly difficult and
time-intensive task of collecting appropriate data and developing the calculation baseline.
As a result, EPA has developed a new approach to the technology-based requirements
that does not require a calculation baseline.
2.2.5.2 Entrainment Exclusion Versus Entrainment Survival
As EPA worked towards revising the existing facility rules, EPA discovered a nuance to
the performance based requirements of the 2004 Phase II rule: entrainment exclusion
versus entrainment survival. As discussed in Section III.C in the proposed rule preamble,
EPA re-reviewed the data on the performance of intake technologies and conducted
statistical analysis of the data. From this analysis, it became apparent that the 2004 Phase
II rule did not fully consider the true performance of intake technologies in affecting
"entrainable" organisms.
By definition, entrainment is the incorporation of aquatic organisms into the intake flow,
which passes through the facility and is then discharged. In order to pass through the
technologies located at the CWIS (e.g., intake screens, nets, etc.), the organisms must be
smaller than the smallest mesh size.l For coarse mesh screens (3/8" mesh size), most
"entrainables" simply pass through the mesh (and through the facility) with only some
contact with the screen.15 In this situation the mortality of organisms passing through the
facility was assumed to be 100 percent, although some facilities have since collected data
showing survival of certain hardier species and lifestages of aquatic organisms. However,
as mesh sizes are reduced,16 more and more entrainables will actually become impinged
on the screens (i.e., "converted" from entrainable to impingeable) and would then be
subjected to spray washes and return along with larger impinged organisms as well as
debris from the screens. Under the 2004 Phase II rule, these "converts" would be
classified as a reduction in entrainment, since the entrainment performance standard
simply required a reduction in the number (or mass) of entrained organisms entering the
cooling system. However, for some facilities, the low survival rate of converts would
have resulted in the facility have difficulty complying with the impingement mortality
performance standards. By comparison, the performance standard for impingement was
measured as impingement mortality. Organisms that were impinged (i.e., excluded) from
the CWIS were typically washed into a return system and sent back to the source water.
In this case, impingement mortality is an appropriate measure of the biological
performance of the technology.
14 In the case of many soft-bodied organisms such as eggs and larvae, the force of the intake flow can be
sufficient to bend organisms that are actually larger than the screen mesh and pull them into the cooling
system.
15 Eggs are generally smaller than 2 millimeters in diameter, while larvae head capsids are much more
variable in size, increasing as they mature to the juvenile stage.
16 Fine mesh screens were considered to be one technology that could be used to meet the entrainment
performance standards under the 2004 Phase II rule. EPA also reviewed performance data for screens with
mesh sizes as small as 0.5 mm, as described in section III.C.
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Through EPA's review of control technologies, the Agency found that the survival of
"converts" on fine mesh screens was very poor, and in some extreme cases comparable to
the extremely low survival of entrained organisms that are allowed to pass entirely
through the facility.1? More specifically, EPA found that most eggs were entrained unless
the mesh slot size was 2.0 mm or less, and mortality of eggs "converted" to impingement
approached 20 to 30 percent. More telling, the mortality of larvae off a fine mesh screen
was rarely less than 80 percent. As a result, a facility with entrainment exclusion
technologies such as fine mesh screens could approach 90 percent performance, but the
subsequent survival of these organisms overall ranged from 0 to 52 percent, and the
facility's impingement mortality rates increased. In other words, a facility that simply
excluded entrainable organisms (with no attention being paid to whether they survive or
not) could be deemed to have met its entrainment requirements under the 2004 Phase II
rule, when in fact it may be causing the same level of mortality as a facility with no
entrainment controls at all.
2.2.5.3 Cost-Cost Test
In the 2004 Phase II rule, EPA developed facility-specific cost estimates, and published
those costs in Appendix A (69 FR 41669). The 2004 Phase II rule also included a cost-
cost test (see 69 FR 41644) where a facility could demonstrate that its costs to comply
with the 2004 rule were significantly greater than those that EPA had considered. Since
initial implementation of the July 9, 2004 316(b) Phase II rule, EPA has identified several
concerns with the facility-specific cost as well as the use of that cost in Appendix A.
First, EPA has identified numerous inconsistencies between facility permit applications,
responses in the facility's 316(b) survey, and overall plant capacity as reported in the
most recent EIA database. These inconsistencies resulted in Appendix A costs that were
not comparable to many facility's own compliance cost estimates.
In addition, as described more fully in Chapter 8, EPA does not have available technical
data for all existing facilities. EPA obtained the technical data for facilities through
industry questionnaires. In order to decrease burden associated with these questionnaires,
EPA requested detailed information from a sample, rather than a census, of facilities.
EPA has concluded that the costs provided in Appendix A are not appropriate for use in a
facility-level cost-cost test. As a result, EPA is not providing a framework similar to
Appendix A in the existing facilities rule. (See the final rule preamble and Chapter 8 of
the TDD for more information about how EPA developed compliance costs.) The
impingement mortality requirements of the existing facilities rule are economically
achievable,18 and the low variability in the costs of EVI controls at a facility makes such a
provision ineffectual. Furthermore, the existing facilities rule requirements for
entrainment mortality requires facilities to submit facility-specific compliance cost
estimates. The determination of whether the cost of specific entrainment mortality
17 Through-plant entrainment survival has been studied extensively, with EPRFs Review of Entrainment
Survival Studies being amongst the most comprehensive. See DCN 2-017A-R7 from the Phase I docket.
18 The Phase II rule found impingement mortality (plus entrainment on certain waterbodies) was
economically achievable; EPA has not identified any reason this revising this conclusion. See Response to
Comment 316bEFR.330.009 in the Phase II Response to Comment Document (DCN 6-5049).
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technologies is too high is made by the Director on a site-specific basis; accordingly a
cost-cost provision is unnecessary.
2.2.6 New or Revised Analyses
In addition to collecting new information, EPA has re-evaluated some existing data and
analyses.
2.2.6.1 Review of Study Data/New Performance Database
The standards of the 2004 Phase II regulation required impingement mortality reduction
for all life stages offish and shellfish of 80 to 95 percent from the calculation baseline
(for all Phase II facilities) and entrainment reduction requirements of 60 to 90 percent
(for certain Phase II facilities). EPA based these performance requirements on a suite of
technologies and compliance alternatives.
For the existing facilities rule, EPA reanalyzed BTA. This includes, but is not limited to,
a re-analysis of candidate BTA technologies, their effectiveness, their costs, and their
application. This section highlights some of the major changes resulting from this re-
analysis. See the preamble for today's final rule for a thorough discussion of EPA's
updated BTA analysis and determination.
New Performance Database
As described above, in its section 316(b) rule development efforts to date, EPA has
gathered industry documents and research publications with information from studies
which evaluated the performance of a range of technologies for minimizing impingement
or entrainment.
EPA subsequently used this database to develop impingement mortality and entrainment
performance standards. However, as described in the preamble, the performance data for
screens and other intake technologies did not indicate that those technologies were nearly
as effective at minimizing impingement and entrainment as closed-cycle cooling.
Impingement Mortality and Entrainment Technology Performance Estimates
To evaluate the effectiveness of different control technologies and the extent to which the
various regulatory options considered for the existing facilities rule minimize adverse
environmental impacts associated with cooling water intake structures, EPA used the data
collected in the new analysis to develop impingement mortality and entrainment
reduction estimates. For some technologies, the existing facilities rule reflects updated
information or a different methodology for estimating effectiveness.
2.2.6.2 Cooling Towers
In the 2004 Phase II rule, EPA estimated facilities employing freshwater cooling towers
and saltwater cooling towers would achieve flow reductions, and therefore associated
entrainment and impingement mortality reductions, of 98 percent and 70-96 percent,
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 2: Summary of Data Collection
respectively.19 At that time, EPA's record demonstrated that saltwater cooling towers
typically operated at 1.1-2.0 cycles of concentration. However, more recent information
demonstrates that, as a result of advances in design and operation, saltwater cooling
towers typically operate at 1.5 cycles of concentration (COC) or more. This equates to a
94.9 percent reduction in flow over a once-through cooling system. To better reflect the
advances in cooling tower design, EPA now estimates that freshwater cooling towers and
saltwater cooling towers reduce impingement mortality and entrainment by 97.5 percent
(based on a COC of 3.0) and 94.9 percent, respectively.20
2.2.6.3 Exclusion Technologies
As discussed in Chapter 6, screens and other technologies operate using a principle of
excluding organisms from entering the cooling system. For technologies other than
cooling towers, EPA generally calculated their efficacy as the mean percent efficacy of
the available data. Because EPA has sufficient data to evaluate impingement mortality, its
impingement mortality technology efficacy calculations account for mortality. However,
because EPA has data on entrainment exclusion but lack sufficient entrainment mortality
data to calculate exclusion technology entrainment mortality efficacy, EPA's calculated
mean entrainment percent efficacy does not account for mortality. In reality, whether or
not an organism is excluded from the cooling water intake does not minimize
entrainment-related environmental impacts unless the excluded organisms survive and
ultimately are returned back to the waterbody. Available data on the technology basis
demonstrate that entrainment reductions associated with fine mesh technologies vary
depending on life stage and mesh size.
In the 2004 Phase II rule, EPA made the assumption that any organism entrained died
(i.e., 100 percent mortality for organisms passing through the facility) and any organism
not entrained survived. In other words, if a technology reduced entrainment by 60
percent, then EPA estimated 40 percent of the organisms present in the intake water
would die in comparison to 100 percent in the absence of any entrainment reduction. As
explained in this section EPA has received new data on this issue, and found that some
sites could demonstrate entrainment survival of select hardier species under certain
conditions. However, the overall entrainment survival is still extremely low. As such,
EPA has not altered its conclusion that, for purposes of national level estimates,
entrainment leads to 100 percent mortality of entrainable organisms.
EPA analyzed the limited data on the survivability of organisms that are "converted"
from entrained to impinged on fine mesh screens. These data show that under most
operational conditions, many, if not all, larvae may die as a result of the impact on fine
mesh screens. In the case of eggs, the data indicate that some species may die, while
others may survive. The data also demonstrate that if the organisms can withstand the
19 As discussed in the preamble, impingement mortality and entrainment reductions are proportional to flow
reductions.
20 Note that, in the final rule, EPA is not including explicit requirements for cooling towers to achieve a
specific percent reduction or COC. EPA provided these COC values as indicative of cooling towers that are
being properly operated to minimize makeup and blowdown flows.
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Chapter 2: Summary of Data Collection § 316(b) Existing Facilities Final Rule - TDD
initial impingement on the fine mesh screen, the majority of organisms survive after
passing through a fish return and returning to the source water.
2.2.6.4 Compliance Cost Methodology
To assess the economic impact of various regulatory control options, EPA estimates the
costs associated with regulatory compliance. These costs of compliance may include
initial fixed and capital costs, annual operating and maintenance costs, downtime costs,
recordkeeping, monitoring, studies, and reporting costs. The costs estimates reflect the
incremental costs attributed only to the existing facilities rule.
For the purposes of estimating incremental compliance costs attributable to regulatory
requirements, EPA traditionally develops either facility-specific or model facility costs.
Facility-specific compliance costs require detailed process information, including
production, capacity, water use, overall management, monitoring data, geographic
location, financial conditions, and other industry-specific data for each facility. When
facility-specific data are not available, EPA develops model facilities to provide a
reasonable representation of the industry.
As discussed in the preamble and the TDD, model facility costs were developed for
facilities that completed a detailed industry questionnaire (and therefore the facilities for
which EPA had the best and most detailed information) and national costs were estimated
by multiplying model facility costs by a weighting factor.
EPA has also adopted a new methodology for estimating costs for retrofitting to closed-
cycle cooling. EPRI developed a cost model that incorporates facility-specific data and
reflects state-of-the-art cooling tower design. This model was based on a number of site-
specific engineering design studies at facilities across the U.S. and incorporates a wide
variety of site conditions and facility characteristics. The model is also capable of
incorporating design features such as plume abatement.
EPA also made other changes to its costing assumptions and approaches. For a summary
discussion of these revisions, see the preamble and Chapter 8 of the TDD.
2.2.6.5 Case Studies (Environmental Impacts, Thermal Impacts)
EPA conducted a brief review of NPDES 316(a) and (b) conditions in NPDES permits.
Addressing Section 316(a) Permit Provisions
The various methods used to address relevant CWA section 316(a) provisions in permit
91
limitations for thermal discharges are compared in Exhibit 2-4. Of the 103 permits
reviewed, approximately half (53 percent) had some form of effluent temperature
limitations. These were divided between facility permits with some form of an EPA-
approved 316(a) variance (33 percent) and those with temperature limits based on either
State temperature standards or a State-approved model or mixing zone study (20 percent).
21 For a description of the entire analysis, see DCN 10-6623.
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 2: Summary of Data Collection
Exhibit 2-4. Methods used to address Section 316(a) requirements by EPA Region
EPA
Region1
2
3
4
5
6
7
9
10
Total
Permits
8
15
23
20
19
5
5
8
103
None
Given
(Towers
in place)
1
3
1
5
(7%)
(16%)
(20%)
(5%)
Not
Specified
2
3
5
(11%)
(38%)
(5%)
No Temp.
Limits/ No
Monitoring
1
3
5
1
10
(7%)
(13%)
(26%)
(13%)
(10%)
Temp.
Guidance/
Monitoring
Only
2
3
6
10
3
3
1
28
(25%)
(20%)
(26%)
(50%)
(16%)
(60%)
(13%)
(27%)
Application of
State Temp.
Limits/ Mixing
Zone (No
316(a) Req.)
3
2
4
3
6
1
2
21
(38%)
(13%)
(17%)
(15%)
(32%)
(20%)
(25%)
(20%)
316(a)
Variance
Study
3
8
10
7
1
4
1
34
(38%)
(53%)
(43%)
(35%)
(20%)
(80%)
(13%)
(33%)
1 No permits from Regions 1 or 8 were included in the permit review
For the 47 percent of the facilities with no temperature limits in their permit;
approximately 27 percent had temperature monitoring and reporting requirements. The
remaining 20 percent of the facilities had no permit-based temperature limitations (this
included 5 percent with existing cooling towers).
Of the 34 permits with approved 316(a) variances, 17 were approved with historic
evaluation studies that were typically 15-25 years old or of indeterminate vintage
(i.e., insufficient evidence to date effort), with two of these scheduled for a re-evaluation
during the next permit cycle. For 10 of the 13 permits with historic variance studies, the
regional permit quality review (PQR) material indicated that documentation of the study
was not available as part of the permit package. Seventeen facilities had updated 316(a)
studies that had been completed within the last five years.
A comparison was made of the section 316(a) permit provisions between electrical power
generating plants and manufacturers nationwide. The large majority (77 percent) of the
twenty-two manufacturing facilities had either no effluent temperature limitations or
monitoring and reporting requirements. None of manufacturers had an approved 316(a)
variance study whereas 42 percent of the power plants did.
Addressing Section 316(b) Permit Provisions
The various methods used to address relevant section 316(b) provisions in permit
limitations are compared in Exhibit 2-5. A breakdown of the compliance categories
indicates that 51 percent of the facilities' permit conditions contained little or no
references to 316(b) regulations. Further analysis of the 316(b) provision status
nationwide indicates that none of the manufacturing facilities had 316(b) requirements
specified in their permits, while 36 percent of the generators had none.
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Chapter 2: Summary of Data Collection
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 2-5. Methods used to address Section 316(b) requirements by EPA Region
EPA
Region
2
3
4
5
6
7
9
10
Total
Permits
8
15
23
20
19
5
5
8
103
Not
Specified
4
3
15
5
13
2
8
50
(50%)
(20%)
(65%)
(25%)
(68%)
(40%)
(100%)
(49%)
None
2
2
(11%)
(2%)
CDS3, not
initiated
1
4
2
3
3
4
17
(13%)
(27%)
(9%)
(15%)
(60%)
(80%)
(17%)
CDS,
ongoing
3
4
2
9
(20%)
(20%)
(11%)
(9%)
Approved permit
conditions
Historic
Evaluations
1
3
4
8
(7%)
(13%)
(20%)
(8%)
Current Re-
evaluation
3
2
4
2
11
(38%)
(9%)
(20%)
(11%)
(11%)
New
Facility
(subject
to
Phase I)
2
2
(13%)
(2%)
None
Given
(Tower in
place)
2
1
1
4
(13%)
(4%)
(20%)
(4%)
l:"CDS" refers to Comprehensive Demonstration Study
Approximately 19 percent of the facilities had an approved 316(b) demonstration; which
included 11 percent that were scheduled for a re-evaluation during the next permit cycle.
Nine percent of the facilities reportedly had initiated a CDS investigation while 17
percent were required to conduct the CDS within the current 5-year permit cycle but had
not started at the time of permit issuance. The current status of these CDS activities is
uncertain due to the remand of the Phase II facility 316(b) regulations in midst of the
current permit cycle. Specifically, on July 9, 2007 (72 FR 37107), EPA suspended the
bulk of the Phase II 316(b) regulation and announced that, pending further rulemaking
(currently ongoing), permit requirements for cooling water intake structures at Phase II
facilities should be established on a site-specific, best professional judgment (BPJ) basis.
Of the 103 facilities reviewed, eleven facilities had cooling towers already installed with
an additional six facilities in the process of installing cooling towers.
Overview of New or Revised Analyses
A review of 103 NPDES permits, together with corresponding factsheets and relevant
EPA PQR documents, identified permit effluent limitations and/or operating conditions
pertaining to how generation and manufacturing facilities dealt with potential sections
316(a) and 316(b) permit provisions. Based on this review:
• Of the permits reviewed, 53 percent had effluent temperature limitations either
based on EPA-approved 316(a) variance (33 percent of all facilities) or State-
approved models or mixing zone studies (20 percent). The remaining facilities
either had no temperature limits (20 percent) or monitoring only (27 percent);
• For facilities with approved 316(a) variances, about half were based on historic
studies or required re-evaluation the following permit cycle, while half were
based on updated 316(a) studies conducted within the last five years;
• Permit temperature limitations for maximum temperature varied widely between
states and environmental settings. Permit limits for allowable deviation from
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 2: Summary of Data Collection
ambient conditions generally adhered to States water quality temperature
standards;
• Over half (51 percent) of the NPDES permits reviewed did not contain any
reference to section 316(b) requirements. However, inclusion of 316(b)
compliance requirements varied widely between permits for manufacturing
facilities (0 percent included 316(b) requirements) and generators (64 percent);
and
• Cooling towers were installed in 11 and were scheduled to be installed at six of
the 103, or 16 percent of all, facilities considered.
2.2.6.6 Closed-cycle Cooling
EPA considered a wide variety of technical aspects associated with retrofitting cooling
towers, including (but not limited to) the availability of land, noise and plume effects,
evaporative losses, and nuclear safety concerns.
As discussed in Chapter 10 of the TDD, EPA had previously conducted analyses for
these effects; Chapter 10 provides the updated analyses.
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§ 316(b) Existing Facilities Final Rule - TDD Chapters: Scope/Applicability of Final Rule
Chapter 3: Scope/Applicability of Final Rule
3.0 Introduction
The final rule includes all existing facilities with a DIP of more than 2 mgd. EPA
estimates that a total of 1,065 facilities will be subject to the final rule, including 544
Electric Generators, 509 Manufacturers in six Primary Manufacturing Industries, and 12
Manufacturers in Other Industries. The rule also clarifies the definition and requirements
for new units at existing facilities. The applicable requirements are summarized in
Exhibits 3-1 and 3-2.
Exhibit 3-1. Applicability by phase of the 316(b) rules
Facility characteristic Applicable rule
New power-generating or manufacturing facility Phase I rule
New offshore oil and gas facility Phase III rule
New unit at an existing power-generating or manufacturing facility This rule
Existing power-generating or manufacturing facility This rule
Existing offshore oil and gas facility and seafood processing facilities This rule (site-specific, BPJ)
Exhibit 3-2. Applicable requirements of today's rule for existing facilities
Facility characteristic Applicable requirements
Existing facility with a DIP greater than 2 mgd and Impingement mortality requirements at 40
an AIF (actual intake flow) greater than 125 mgd CFR125.94(c) (categorical rule) and Director
determination of BTA for entrainment based on
characterization and study requirements at 40
CFR125.94(d)
Existing facility with a DIP greater than 2 mgd but Impingement mortality standards at 40 CFR
AIF not greater than 125 mgd 125.94(c)and Director determination of BTA for
entrainment requirements under 40 CFR125.94(d)
New unit at an existing facility where the facility has New unit entrainment standards at 40
a DIP greater than 2 mgd CFR125.94(e) (categorical rule)
Other existing facility with a DIP of 2 mgd or smaller Site-specific, BPJ
or that has an intake structure that withdraws less
than 25 percent of the water for cooling purposes on
an actual intake flow basis
At an early stage in the development of section 316(b) requirements, EPA divided its
rulemaking effort into three phases. The first addressed new facilities, the second, large
existing electricity utility facilities and the third, the remaining electric generating
facilities not addressed in the earlier phases as well as existing manufacturing operations.
As EPA's analysis progressed, however, it became clear that it could address in one
rulemaking cooling water intake structures at both steam electric and manufacturing
facilities. From a biological perspective, the effect of intake structures on impingement
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Chapters: Scope/Applicability of Final Rule § 316(b) Existing Facilities Final Rule - TDD
99
and entrainment does not differ depending on whether an intake structure is associated
with a power plant or a manufacturer. EPA has here consolidated the universe of
potentially regulated facilities from the remanded 2004 Phase II rule with the existing
facilities in the remanded 2006 Phase III rule for establishing requirements in a single
proceeding.
3.1 General Applicability
This rule applies to owners and operators of existing facilities23 that meet all following
criteria:
• The facility is a point source that uses or, in the case of a new unit at an existing
facility, proposes to use cooling water from one or more cooling water intake
structures, including a cooling water intake structure operated by an independent
supplier not otherwise subject to 316(b) requirements that withdraws water from
waters of the United States and provides cooling water to the facility by any sort
of contract or other arrangement;
• The facility-wide DIP for all cooling water intake structures at the facility is
greater than 2 mgd;
• The cooling water intake structure withdraws cooling water from waters of the
United States; and
• At least 25 percent of the water actually withdrawn — actual intake flow (AIF) —
is used exclusively for cooling purposes.
A facility may choose to demonstrate compliance with the final rule for the entire facility,
or for each individual cooling water intake structure.
EPA is adopting provisions that promote the reuse of certain water for cooling and that
ensure that the rule does not discourage the reuse of cooling water for other uses such as
process water. The final rule at 40 CFR 125.91(c) specifies that obtaining cooling water
from a public water system, using reclaimed water from wastewater treatment facilities or
desalination plants, or recycling treated process wastewater effluent (such as wastewater
treatment plant "gray" water) does not constitute use of a cooling water intake structure
for purposes of this rule. In addition, the definition of cooling water at 40 CFR 125.92
provides that cooling water obtained from a public water system, reclaimed water from
wastewater treatment facilities or desalination plants, treated effluent from a
manufacturing facility, or cooling water used in a manufacturing process either before or
after it is used for cooling is considered process water for the purposes of calculating the
percentage of a facility's intake flow that is used for cooling purposes. Therefore, water
used for both cooling and non-cooling purposes does not count toward the 25 percent
22 Throughout the preamble and support documents, the terms "entrainment" and "entrainment mortality"
may be used interchangeably. The record shows that, in most instances, entrainment mortality is 100
percent, leaving little distinction between the two terms.
23 Throughout the preamble and supporting documents, the terms "owner or operator of a facility" and
"facility" may be used interchangeably. In cases where the document may state that a facility is required to
do a given activity, it should be interpreted as the owner or operator of the facility is required to do the
activity.
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§ 316(b) Existing Facilities Final Rule - TDD Chapters: Scope/Applicability of Final Rule
threshold. Examples of water withdrawn for non-cooling purposes includes water
withdrawn for warming by LNG (liquefied natural gas) facilities and water withdrawn for
public water systems by desalinization facilities.
Today's rule focuses on those facilities that are significant users of cooling water. The
rule provides that only those facilities that use more than 25 percent of the water
withdrawn exclusively for cooling purposes (on an actual intake flow basis) are subject to
the rule. Because power-generating facilities typically use far more than 25 percent of the
water they withdraw exclusively for cooling purposes, the 25 percent threshold will
ensure that intake structures accounting for nearly all cooling water used by the power
sector are addressed by today's rule requirements. While manufacturing facilities often
withdraw water for more purposes than cooling, the majority of the water is withdrawn
from a single intake structure. Once water passes through the intake, water can be
apportioned to any desired use, including uses that are not related to cooling. However, as
long as at least 25 percent of the water is used exclusively for cooling purposes, the
intake is subject to the requirements of today's rule. EPA estimates that approximately
68 percent of manufacturers and 93 percent of power-generating facilities that meet the
first three criteria for applicability also use more than 25 percent of intake water for
cooling and thus are subject to today's rule. (See 66 FR 65288, December 18, 2001.)
For facilities that are below any of the applicability thresholds in today's rule, for
example a facility that withdraws less than 25 percent of the intake flow for cooling
purposes, the Director must set appropriate requirements on a site-specific basis, using
best professional judgment (BPJ), based on 40 CFR 125.90(b). Today's rule is not
intended to constrain permit writers at the Federal, State, or Tribal level, from addressing
such cooling water intake structures. Also, EPA decided to adopt for the final rule the
proposed provision that requires the owners and operators for certain categories of
facilities (existing offshore oil and gas facilities, existing offshore seafood processing
facilities and offshore LNG terminals) to meet site-specific BTA impingement and
entrainment requirements, established by the Director. Such facilities are subject to
permit conditions implementing CWA section 316(b) if the facility is a point source that
uses a cooling water intake structure and has, or is required to have, an NPDES permit.
3.1.1 What is an "Existing Facility" for Purposes of the Final Rule?
In today's rule, EPA is defining the term "existing facility" to include any facility that is
not a "new facility" as defined in 40 CFR 125.83.
A point source discharger would be subject to Phase I or today's rule even if the cooling
water intake structure it uses is not located at the facility24. In addition, modifications or
additions to the cooling water intake structure (or even the total replacement of an
existing cooling water intake structure with a new one) does not convert an otherwise
unchanged existing facility into a new facility, regardless of the purpose of such changes
(e.g., to comply with today's rule or to increase capacity). Rather, the determination as to
24 For example, a facility might purchase its cooling water from a nearby facility that owns and operates a
cooling water intake structure.
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Chapters: Scope/Applicability of Final Rule § 316(b) Existing Facilities Final Rule - TDD
whether a facility is new or existing focuses on whether it is a greenfield or stand-alone
facility and whether there are changes to the cooling water intake to accommodate it.
3.1.2 What is "Cooling Water" and What is a "Cooling Water Intake
Structure?"
EPA has not revised the definition of cooling water intake structure from proposal for
today's rule. A cooling water intake structure is defined as the total physical structure and
any associated constructed waterways used to withdraw cooling water from waters of the
United States. Under the definition in today's rule, the cooling water intake structure
extends from the point at which water is withdrawn from the surface water source up to,
and including, the intake pumps. The final rule at 40 CFR 125.91(c) also specifies that
obtaining cooling water from a public water system, using reclaimed water from
wastewater treatment facilities or desalination plants, or recycling treated effluent (such
as wastewater treatment plant "gray" water) does not constitute use of a cooling water
intake structure for purposes of this rule.
Today's rule adopts the new facility rule's definition of cooling water as water used for
contact or non-contact cooling, including water used for equipment cooling, evaporative
cooling tower makeup, and dilution of effluent heat content. The definition specifies that
the intended use of cooling water is to absorb waste heat not being efficiently used or
recaptured for production and thus rejected from the processes used or auxiliary
operations on the facility's premises. The definition also indicates that cooling water
obtained from a public water system, reclaimed water from wastewater treatment
facilities or desalination plants, treated effluent from a manufacturing facility that is used
in a manufacturing process either before or after it is used for cooling, or is process water
would not be considered cooling water for purposes of determining whether 25 percent or
more of the actual intake flow is cooling water. This clarification is necessary because
cooling water intake structures typically bring water into a facility for numerous
purposes, including industrial processes; use as circulating water, service water, or
evaporative cooling tower makeup water; dilution of effluent heat content; equipment
cooling; and air conditioning. Note, however, that all intake water (including cooling and
non-cooling process) is included in the determination as to whether the 2-mgd DIP
threshold for covered intake structures is met.
3.1.3 Would My Facility Be Covered Only if it is a Point Source
Discharger?
Today's rule applies only to facilities that have an NPDES permit or are required to
obtain one. This is the same requirement EPA included in the Phase I new facility rule at
40 CFR 125.81(a)(l). Requirements for complying with CWA section 316(b) will
continue to be applied through NPDES permits.
On the basis of the Agency's review of potential existing facilities that employ cooling
water intake structures, the Agency anticipates that most facilities will control the intake
structure that supplies them with cooling water, and discharge some combination of their
cooling water, wastewater, or stormwater to a water of the United States through a point
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§ 316(b) Existing Facilities Final Rule - TDD Chapters: Scope/Applicability of Final Rule
source regulated by an NPDES permit. In such cases, the facility's NPDES permit must
include the requirements for the cooling water intake structure. If an existing facility's
only NPDES permit is a general permit for stormwater discharges, the Agency anticipates
that the Director would write an individual NPDES permit containing requirements for
the facility's cooling water intake structure. Alternatively, requirements applicable to
cooling water intake structures could be incorporated into general permits. If
requirements are placed into a general permit, they must meet the requirements set out at
40 CFR 122.28.
As EPA stated in the preamble to the final Phase I rule (66 FR 65256, December 18,
2001), the Agency encourages the Director to closely examine scenarios in which a
facility withdraws significant amounts of cooling water from waters of the United States
but is not required to obtain an NPDES permit. As appropriate, the Director must apply
other legal requirements, where applicable, such as CWA sections 401 or 404, the
Coastal Zone Management Act, the National Environmental Policy Act, the Endangered
Species Act, or similar State or Tribal authorities to address adverse environmental
impact caused by cooling water intake structures at those facilities.
3.1.4 Would My Facility Be Covered if it Withdraws Water From
Waters of the United States? What if My Facility Obtains Cooling
Water from an Independent Supplier?
The requirements in today's rule apply to cooling water intake structures that have the
design capacity to withdraw more than 2 mgd from waters of the United States. Waters of
the United States include the broad range of surface waters that meet the regulatory
definition at 40 CFR 122.2, which includes lakes, ponds, reservoirs, nontidal rivers or
streams, tidal rivers, estuaries, fjords, oceans, bays, and coves. These potential sources of
cooling water can be adversely affected by impingement and entrainment.
Some facilities use an impoundment such as a man-made pond or reservoir as part of
their cooling system. Cooling water is withdrawn from the pond or reservoir at one point
and heated water is discharged to a different point, using mixing and evaporative
processes. These impoundments can be closed-cycle recirculating systems if the pond or
reservoir was not constructed by impounding a water of the U.S., and therefore might
already comply with some of or all the technology-based requirements in today's rule. In
other cases, the impoundment was lawfully created from a water of the U.S. as part of a
cooling system. Facilities that withdraw cooling water from impoundments that are
waters of the United States and that meet the other criteria for coverage (including the
requirement that the facility has or will be required to obtain an NPDES permit) are
subject to today's rule. In many cases, EPA expects that such makeup water withdrawals
are commensurate with the flows of a closed-cycle cooling tower, and again the facility
might already comply with requirements to reduce its intake flow under the rule. In those
cases where the withdrawals of makeup water come from a water of the United States,
and the facility otherwise meets today's criteria for coverage (including a DIP of greater
than 2 mgd), the facility would be subject to today's rule requirements. Some of these
impoundments may qualify for the waste treatment exclusion found in the definition of a
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Chapters: Scope/Applicability of Final Rule § 316(b) Existing Facilities Final Rule - TDD
waste treatment system at 40 CFR 122.2, and this rule does not affect the applicability of
that exclusion.
EPA does not intend for this rule to change the regulatory status of impoundments.
Impoundments are neither categorically included nor categorically excluded from the
definition of waters of the United States at 40 CFR 122.2. The determination whether an
impoundment is a water of the United States is to be made by the Director on a site-
specific basis. The EPA and the U.S. Army Corps of Engineers have jointly issued
jurisdictional guidance concerning the term waters of the United States in light of the
Supreme Court's decision in Solid Waste Agency of Northern Cook County v. U.S. Army
Corps of Engineers, 531 U.S. 159 (2001) (SWANCC). A copy of that guidance was
published as an Appendix to an Advanced Notice of Proposed Rulemaking on the
definition of the phrase waters of the United States, see 68 FR 1991, January 15, 2003,
which is at http://www.epa.gov/owow/wetlands/pdf/ANPRM-FR.pdf The agencies
additionally published guidance in 2008 regarding the term waters of the United States in
light of both the SWANCC and subsequent Rapanos case (Rapanos v. United States, 547
U.S. 715 (2006)).
EPA recognizes that some impoundments may be man-made waterbodies that support
artificially managed and stocked fish populations. As a result, EPA has included a
provision in today's final rule to allow the Director to waive certain permit application
requirements for such facilities. Note, however, that these facilities are still subject to the
final rule.
EPA acknowledges that the point of compliance for facilities located on impoundments
may also vary depending on whether the facility withdraws from a water of the United
States. As such, the Director may impose requirements at the facility's main cooling
water intake structure or at its makeup water withdrawal intake.
The Agency recognizes that some facilities that have or are required to have an NPDES
permit might not own and operate the intake structure that supplies their facility with
cooling water. In addressing facilities that have or are required to have an NPDES permit
that do not directly control the intake structure that supplies their facility with cooling
water, revised 40 CFR 125.91 provides (similar to the new facility rule) that facilities that
obtain cooling water from a public water system, use reclaimed water from a wastewater
treatment facility or desalinization plant, or use treated effluent are not deemed to be
using a cooling water intake structure for purposes of this rule. However, obtaining water
from another entity that is withdrawing water from a water of the United States would be
counted as using a cooling water intake structure for purposes of determining whether an
entity meets the threshold requirements of the rule. For example, facilities operated by
separate entities might be located on the same, adjacent, or nearby property. One of these
facilities might take in cooling water and then transfer it to other facilities that discharge
to a water of the United States. Section 125.91(b) specifies that use of a cooling water
intake structure includes obtaining cooling water by any sort of contract or arrangement
with one or more independent suppliers of cooling water if the supplier or suppliers
withdraw water from waters of the United States but that is not itself a new or existing
facility subject to CWA section 316(b), except if it is a public water system, a wastewater
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§ 316(b) Existing Facilities Final Rule - TDD Chapters: Scope/Applicability of Final Rule
treatment facility or desalination plant providing reclaimed water, or a facility providing
treated effluent for reuse as cooling water pursuant to 125.91(c).
As a practical matter, existing facilities are the largest users of cooling water and
typically require enough cooling water to warrant owning the cooling water intake
structures. In some cases, such as at nuclear power plants or critical baseload facilities,
the need for cooling water includes safety and reliability reasons that would likely
preclude any independent supplier arrangements. Therefore, EPA expects this provision
will have only limited applicability. EPA is nevertheless retaining the provision to
prevent facilities from circumventing the requirements of today's rule by creating
arrangements to receive cooling water from an entity that is not itself subject to today's
rule and that is not explicitly exempt from today's rule (such as drinking water or
treatment plant discharges reused as cooling water).
3.1.5 What Intake Flow Thresholds Result in an Existing Facility
Being Subject to the Final Rule?
EPA determines the cooling water flow at a facility in two ways. The first way is based
on the DIP, which reflects the maximum intake flow the facility is capable of
withdrawing. While this normally is limited by the capacity of the cooling water intake
pumps, other parts of the cooling water intake system could impose physical limitations
on the maximum intake flow the facility is capable of withdrawing. The second way is
based on the AIF, which reflects the actual volume of water withdrawn by the facility.
EPA has defined AIF to be the average water withdrawn each year over the preceding
three calendar years25. Both of these definitions are used in today's rule.
In this rule, EPA considered requirements based on the intake flow at the existing facility.
Today's final rule applies to facilities that have a total design intake capacity of greater
than 2 mgd (see §40 CFR 125.91).26 Above 2 mgd, 99.7 percent of the total water
withdrawals by utilities and other industrial sources could be covered (if the other criteria
for coverage are met), including 70 percent of the manufacturing facilities and 87 percent
of electric generating facilities. EPA also chose the greater than 2-mgd threshold to be
consistent with the applicability criteria in the Phase I rule.27 EPA has concluded that this
threshold ensures that the users of cooling water causing the most adverse environmental
impact will be subject to the rule.
EPA is continuing to base applicability on DIP as opposed to AIF for several reasons. In
contrast to AIF, DIP is a fixed value based on the design of the facility's operating
system and the capacity of the circulating and other water intake pumps. This provides
clarity because the DIF does not vary with facility operations, except in limited
circumstances, such as when a facility undergoes major modifications. On the other hand,
25 For permit terms subsequent to the first permit issued under today's rule, the rule defines AIF as the
average flows over the 5 years in the previous permit term
26 The 2004 Phase II rule would have applied to existing power-generating facilities with a design intake
flow of 50 mgd or greater. Facilities potentially in scope of the Phase III rule had a DIF of greater than
2 mgd.
27 For more information, see 66 FR 65288, December 18, 2001.
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actual flows can vary significantly over sometimes short periods. For example, a peaking
power plant might have an AIF close to the DIP during times of full energy production,
but an AIF of zero during lengthy periods of standby. Use of DIP provides clarity as to
regulatory status, is indicative of the potential magnitude of environmental impact, and
avoids the need for monitoring to confirm a facility's status. For more information about
these thresholds, see 69 FR 41611, July 9, 2004.
Under this rule, all facilities with a DIP of greater than 2 mgd must submit basic
information describing the facility, source water physical data, source water biological
characterization data, and cooling water intake system data. In addition, these facilities
must submit additional facility-specific information including the selected impingement
compliance option and operational status of each of the facility's units.28 Certain facilities
withdrawing the largest volumes of water for cooling purposes have additional
information and study requirements such as relevant biological survival studies and the
Entrainment Characterization Study as described below.
The final rule uses AIF rather than DIP for purposes of determining which facilities must
provide the information required in 40 CFR 122.21(r)(9)-(13), including an Entrainment
Characterization Study. Thus, the rule provides that any facility subject to the rule with
actual flows in excess of 125 mgd must provide an Entrainment Characterization Study
with its permit application. Adverse environmental impacts from entrainment result from
actual water withdrawals, and not the maximum designed level of withdrawal. Further,
using actual flow might encourage some facilities to adopt operational practices to reduce
their flows to avoid collecting supplemental data and submitting the additional
entrainment characterization study. Furthermore, any facility that has DIP greater than 2
mgd is required to submit basic information that will allow the Director to verify its
determination of whether it meets the 125-mgd AIF threshold.
EPA has selected a threshold of 125-mgd AIF for submission of the Entrainment
Characterization Study (as well as studies described at 40 CFR 122.21(r)((7) and
(10)-(13)) because this threshold will capture 90 percent of the actual flows but will apply
only to 30 percent of existing facilities. EPA concluded that this threshold struck the
appropriate balance between the goal of capturing the greatest portion of intake flow
while minimizing the study requirements for smaller facilities. Exhibit 3-3 presents a plot
of cumulative AIF for facilities with AIF sorted from low to high with a marker
illustrating the location of the largest facility that would fall below a threshold of
125 mgd. While there is no obvious break point or change in slope at this particular data
point, it is a reasonable approximation of where the curve begins to flatten out. The
selected threshold would significantly limit facility burden at more than two-thirds of the
potentially in-scope facilities while focusing the Director on major cooling water
withdrawals. Contrary to a number of public comments, however, EPA is not implying or
concluding that the 125-mgd threshold is an indicator that facilities withdrawing less than
125-mgd are (1) not causing any adverse impacts or (2) automatically qualify as
employing BTA. In other words, the threshold, while justified on a technical basis, does
not result in exemptions from the rule. Instead, EPA is making a policy decision on
28 The final rule contains streamlined information submission requirements for facilities that already
employ closed-cycle cooling.
30
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 3: Scope/Applicability of Final Rule
which facilities must provide a certain level and type of information. The Director, of
course, will retain the discretion to require reasonable information to make informed
decisions at the smaller facilities. The 125-mgd threshold is simply an administrative
cutoff that focuses on the facilities with the highest intake flows and the highest
likelihood of causing adverse impacts; it is not an indicator that facilities under that
threshold are no longer of concern in the final rule.
Exhibit 3-3. Plot of Cumulative AIF in MGD
250,000
200,000
150,000
100,000
50,000
In today's rule, EPA seeks to clarify that for some facilities, the DIF is not necessarily the
maximum flow associated with the intake pumps. For example, a power plant might have
redundant circulating pumps, or might have pumps with a name plate rating that exceeds
the maximum water throughput of the associated piping. EPA intends for the DIF to
reflect the maximum rate at which a facility can physically withdraw water from a source
waterbody (usually normalized to a daily rate in mgd). This also means that a facility that
has permanently taken a pump out of service should be able to consider such constraints
when reporting its DIF, as the facility's capacity to withdraw water has fundamentally
changed. Additionally, if a facility's flow is limited by constrictions in the piping or other
physical limitations (e.g., a given portion of its cooling system that can only safely handle
a given amount of flow) and that flow is lower than the DIF for the pumps, the facility
should be able to consider such constraints when reporting its DIF, because it is not
capable of withdrawing its full DIF without compromising the cooling system.
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3.1.6 Existing Offshore Oil and Gas Facilities, Seafood Processing
Vessels or LNG Import Terminals BTA Requirements Under the Final
Rule
Under today's rule, existing offshore oil and gas facilities, seafood processing facilities
and LNG import terminals would be subject to 316(b) requirements on a BPJ basis. In the
Phase III rule, EPA studied offshore oil and gas facilities and seafood processing
facilities29 and could not identify any technologies (beyond the protective screens already
in use) that are technically feasible for reducing impingement or entrainment in such
existing facilities.30 As discussed in the Phase III rule, known technologies that could
further reduce impingement or entrainment would result in unacceptable changes in the
envelope of existing platforms, drilling rigs, mobile offshore drilling units, offshore
seafood processing vessels, and similar facilities as the technologies would project out
from the hull, potentially decrease the seaworthiness, and potentially interfere with
structural components of the hull. It is also EPA's view that for many of these facilities,
the cooling water withdrawals are most substantial when the facilities are operating far
out at sea and, therefore, not withdrawing from a water of the United States. EPA is
aware that LNG facilities may withdraw hundreds of million gallons per day of seawater
for warming (re-gasification). However, some existing LNG facilities might still
withdraw water where 25 percent or more of the water is used for cooling purposes. EPA
has not identified a uniformly applicable and available technology for minimizing
impingement mortality and entrainment at these facilities. However, technologies might
be available for some existing LNG facilities. LNG facilities that withdraw any volume
of water for cooling purposes would be subject to site-specific, BPJ BTA determinations.
EPA has not identified any new data or approaches that would result in a different
determination. Therefore, EPA has adopted the approach of the proposed rule and is
requiring that NPDES permit Directors, on a site-specific basis using BPJ, determine
BTA for existing offshore oil and gas extraction facilities and offshore seafood
processing facilities..
3.1.7 What is a "New Unit" and How Are New Units Addressed Under
the Final Rule?
Today's rule establishes requirements for new units at an existing facility that are
different than the requirements that otherwise apply to existing units at an existing
facility. The requirements for new units at existing facilities are modeled after the
requirements for a new facility in the Phase I rule. Under today's rule, a new unit means
the addition of a newly built, stand-alone unit. EPA is also clarifying that while Phase I
definition of new facility does not include newly constructed units for the same general
29 EPA studied naval vessels and cruise ships as part of its developing a general NPDES permit for
discharges from oceangoing vessels. (For more information, see
http://cfpub.epa.gov/npdes/home.cfm7program id=350.') EPA studied offshore seafood processing vessels
and oil and gas exploration facilities in the 316(b) Phase III rule.
30 As discussed in today's preamble, requirements for new offshore facilities set forth in the Phase III rule
remain in effect.
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industrial activity, such units are new units at an existing facility and are subject to
today's final rule.
On the basis of the public comments received on how to define new units, EPA has
sought to provide a clear definition for this term in the final rule. In EPA's view, these
definitions for a new unit at an existing facility establish a clear regulatory framework for
both affected facilities and Directors. It captures facilities that are undergoing major
construction projects, while not discouraging upgrades or the construction of replacement
units. For example, a nuclear facility conducting a measurement uncertainty capture or a
stretch power uprate (a Type I or Type II uprate) or a fossil-fuel plant repowering the
existing generating units would not be considered a new unit. As another example, under
this definition placing an offshore facility into a dry dock for maintenance or repair does
not result in either the offshore facility or the dry dock as being defined as a new unit.
Electric Generators
The final rule defines a new unit at an existing facility as a newly built, stand-alone unit
that is constructed at an existing facility and that does not meet the definition of a new
facility. An existing unit that is repowered or undergoes significant modifications (such
as where the turbine and condenser are replaced) is not considered a new unit. Exhibit 1-3
below provides several examples and whether these hypothetical units will be defined as
new or existing units.
Exhibit 3-4. Examples of new and existing units at electric generators
Examples of new units at an existing facility Examples of existing units
A unit that is constructed at a stand-alone location An existing unit is retired and demolished, with a
at an existing facility (either adjacent to existing new unit constructed in the former unit's location as
units or on newly acquired or developed property) a replacement (regardless of the change in
generating capacity, the change in cooling water
intake flow, or the use of an existing intake
structure)
A unit where a new boiler or fuel type is employed
(e.g., a new heat recovery steam generator and
combustion turbine is connected to an existing
steam turbine and condenser)
Manufacturers
At the numerous manufacturing facilities that generate electricity onsite, the previous
discussion of electric generators applies. Some manufacturers employ different industrial
processes than an electric generator and therefore have different industrial equipment
(including cooling systems). In particular, manufacturers may not use a steam condenser
or steam turbine for their industrial processes, making the definition for "repowering"
above inappropriate for manufacturing facilities. However, manufacturers do have
opportunities to reuse cooling water that power plants may not, and in site visits, EPA
found many manufacturers have conducted energy and water audits resulting in
significant reductions in water withdrawals. The final rule provides for manufacturers to
receive credit for such reductions in fresh water withdrawals.
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A similar conceptual approach for defining manufacturing units with a new or replaced
cooling system is not as easily defined since waste heat can be generated from a variety
of sources including exothermic processes, product heating and cooling, and the
processing, handling, treating, or disposal of feed streams, waste streams, by-products,
and recycled components. Sources may include direct cooling transferred across an inert
material (e.g., heat exchanger, steam condenser), indirect cooling using a working fluid
(e.g., chillers, refrigeration), or contact cooling where cooling water comes into direct
contact with a product or process stream.31 Unlike electric generators where the majority
of cooling water comes from a single process source (the steam condenser),
manufacturing units may include many separate non-contact or contact cooling water
sources dispersed throughout the production processes and the facility. Thus, a definition
for manufacturing units with a new or replaced cooling system must take into
consideration a broader category of cooling water sources.
Thus for power generators, the term "generating unit" is quite clear since there is only
one product (electricity), the non-contact cooling water predominantly comes from one
source, and the application of the term is well-understood in the industry. But for some
manufacturing facilities, it may be unclear what constitutes a "unit" since manufacturing
processes can involve numerous vertically integrated processes or production steps that
may involve intermediate products. For example, a unit could encompass an entire series
of production steps (start to finish) or simply the individual steps. Also, there may be
ancillary support equipment that serves various functions and it is not clear whether this
will be considered a unit or part of a unit. For example, a petroleum refiner will typically
include various processes such as distillation, cracking, hydrotreating, coking, reforming,
and different types of various products. Various intermediate products from these
processes may be directly transported (piped) from one process to another or stored and
some may be sold. And because various intermediate and final process products may be
blended into different products, differentiating units on a product or intermediate product
basis may not provide clear distinctions.
For these reasons EPA has defined new unit to simply mean a new stand-alone unit or
process. A new unit may include distinct production lines that are added to increase
product output and operate parallel and independently of existing production equipment.
A new unit does not include the replacement or rebuilding of production lines or distinct
processes where the majority of the waste heat producing equipment that serve as sources
of non-contact cooling water and the majority of the heat exchanging equipment that
contributes heat to the non-contact cooling water are replaced. Such modifications do not
lead to considering the unit as a new unit, thereby continuing to treat the unit as an
existing unit. In such cases, the existing unit is regulated under the existing unit
provisions of this rule, and the unit is not subject to new unit requirements.
This definition therefore does not impose any disincentives for the replacement/upgrade
of individual components or ancillary equipment alone.
31Note that EPA did not include contact cooling category as part of its analysis of possible closed-cycle
cooling system requirements but contact cooling water does nonetheless fall within the definition of
cooling water at 40 CFR 125.92.
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Chapters: Scope/Applicability of Final Rule
Exhibit 1-4 below provides several examples and whether these hypothetical units are
defined as new or existing units. As noted above, the Director has broad discretion to
assess the scope of any modifications at the manufacturing facility and to determine
whether the new construction comprises a stand-alone unit. For the purposes of today's
final rule, the Director does not need to address whether the stand-alone unit is for the
same general industrial purposes, or whether the new unit is a replacement unit. The key
factors in assessing whether a unit will be defined as new lies with whether the
construction results in a stand-alone unit.
Exhibit 3-5. Examples of new and existing units at manufacturers
Examples of new units at an existing facility
Examples of existing units
A unit that is constructed at a stand-alone location
at an existing facility (either adjacent to existing
units or on newly acquired or developed property)
A unit where only the waste heat generating
process equipment or the cooling system equipment
is replaced, but not both
A unit that is constructed adjacent to an existing unit
for the same industrial activity (such as expanding
the production output by building a second unit as a
stand-alone unit next to the existing unit)
A unit where modifications are made to the waste
heat generating process equipment or the cooling
system (e.g., optimization, repairs, upgrades to
operational elements up to, but not including full
replacement)
An existing unit is retired before or after a new unit
is constructed as a replacement (regardless of the
change in production capacity, the change in
cooling water intake flow, or the use of an existing
intake structure)
An existing unit is retired and demolished, with a
new unit constructed in the former unit's location as
a replacement (regardless of the change in
production capacity, the change in cooling water
intake flow, or the use of an existing intake
structure)
Replacement or upgrade of ancillary equipment
(e.g., pumps, motors, HVAC, etc.)
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 4: Industry Description
Chapter 4: Industry Description
4.0 Introduction
This chapter presents a profile of the facilities potentially regulated under the existing
facilities rule. The rule would apply national requirements to existing facilities that use
cooling water intake structures to withdraw water for cooling from waters of the U.S.
Specifically, the final rule would apply to owners and operators of existing facilities that
meet all of the following criteria:
• The facility is a point source that uses or proposes to use one or more cooling
water intake structures, including a cooling water intake structure operated by an
independent supplier that withdraws water from waters of the United States and
provides cooling water to the facility by any sort of contract or other arrangement;
• The total design intake flow of the cooling water intake structure(s) is more than 2
mgd; and
• The cooling water intake structure(s) withdraw(s) cooling water from waters of
the United States and at least twenty-five (25) percent of the water withdrawn is
used exclusively for cooling purposes measured on an average annual basis for
each calendar year.
The existing facilities rule would apply to all existing power plants and all existing
manufacturing facilities that meet the above criteria. This chapter presents information
characterizing the categories of facilities subject to the rule.
Much of the information presented in this chapter is based on data from the U.S.
Department of Energy's (DOE) "Annual Electric Generator Report" (Form EIA-860) and
"Annual Electric Power Industry Report" (Form EIA-861), and EPA's Section 316(b)
2000 Industry Surveys (the Industry Short Technical Questionnaire [STQ] and the
Detailed Industry Questionnaire [DQ] for Phase II Cooling Water Intake Structures). For
more information on aspects of the industry that may influence the nature and magnitude
of economic impacts of the existing facilities rule, see the Economic Analysis for the
Final Section 316(b) Existing Facilities Rule (EA).
The electric power industry and the other industries subject to the existing facilities rule
are studied extensively by many organizations and government agencies. DOE's Energy
Information Administration (EIA), among others, publishes a multitude of reports,
documents, and studies on an annual basis. This chapter profile is not intended to
duplicate those efforts. Rather, this profile compiles, summarizes, and presents those
industry data that are important in the context of the technical analysis for the existing
facilities rule. For more information on general concepts, trends, and developments in the
electric power industry and other industries affected by the proposal, see the
"References," section of this chapter.
EPA first described the electricity industry in its April 2002 Phase II Proposed Rule (see
67 FR 17135-17136). A profile of other industries and existing manufacturers was
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Chapter 4: Industry Description § 316(b) Existing Facilities Final Rule - TDD
developed to support the proposed Phase III Rule (see Phase III Proposed Rule TDD;
EPA-821-R-04-015, DCN 7-0004 in the Phase III docket, available at EPA-HQ-OW-
2004-0002-0025 to -0029). While these general descriptions still apply, EPA has updated
some of its earlier estimates to reflect a more current and comprehensive industry profile
for facilities subject to the existing facilities rule.
The glossary located at the end of this chapter provides definitions for all terms that are
bolded and italicized throughout this chapter.
4.1 Industry Overview
This section provides a brief overview of the industry, including descriptions of major
industry sectors and types of generating facilities.
4.1.1 Major Industry Sectors
In 1997, EPA estimated that over 400,000 facilities could potentially be subject to a
cooling water intake regulation. Given the large number of facilities potentially subject to
regulation, EPA decided to focus its data collection efforts on six industrial categories
that, as a whole, are estimated to account for over 99 percent of all cooling water
withdrawals. These six sectors are: Utility Steam Electric, Nonutility Steam Electric,
Chemicals & Allied Products, Primary Metals Industries, Petroleum & Coal Products,
and Paper & Allied Products. EPA's data collection efforts (via the 1998 industry
questionnaire) focused on the electric generators (both utility and nonutility steam
electric) and the four manufacturing industry groups that were identified as significant
users of cooling water. These industries are presented below, as described by the
Standard Industrial Classification (SIC) system, and are intended to represent all electric
generators and manufacturers with a DIP greater than 2 mgd.
Electric Services
This industry sector is classified under SIC Major Group 49. This major group includes
establishments engaged in the generation, transmission, and/or distribution of electricity
or gas or steam. A detailed discussion of the electricity industry is provided in Section 4.2
of this chapter.
Chemical and Allied Products
This industry sector is classified under SIC Major Group 28. This major group includes
establishments producing basic chemicals and establishments manufacturing products by
predominantly chemical processes. Establishments classified in this major group
manufacture three general classes of products: (1) basic chemicals, such as acids,
alkalies, salts, and organic chemicals; (2) chemical products to be used in further
manufacture, such as synthetic fibers, plastics materials, dry colors, and pigments; and
(3) finished chemical products to be used for ultimate consumption, such as drugs,
cosmetics, and soaps; or to be used as materials or supplies in other industries, such as
paints, fertilizers, and explosives.
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 4: Industry Description
Primary Metals Industries
This industry sector is classified under SIC Major Group 33. This major group includes
establishments engaged in smelting and refining ferrous and nonferrous metals from ore,
pig, or scrap; in rolling, drawing, and alloying metals; in manufacturing castings and
other basic metal products; and in manufacturing nails, spikes, and insulated wire and
cable.
Paper and Allied Products
This industry sector is classified under SIC Major Group 26. This major group includes
establishments primarily engaged in the manufacture of pulps from wood and other
cellulose fibers, the manufacture of paper and paperboard, and the manufacture of paper
and paperboard into converted products.
Petroleum and Coal Products
This industry sector is classified under SIC Major Group 29. This major group includes
establishments primarily engaged in petroleum refining, manufacturing paving and
roofing materials, and compounding lubricating oils and greases from purchased
materials.
Other Industries
EPA sent industry questionnaires to individual facilities from a number of other
industries outside of the four listed above and incorporated that data into the analysis for
the existing facilities rule. In 2004, EPA also collected information on land-based
liquefied natural gas (LNG) facilities.
The following sections describe the electricity industry and the other manufacturing
sectors and describe how cooling water is withdrawn and used at these facilities. In many
cases, the facility data has been aggregated into two major groups; Electric Generators
(Electric Services) and Manufacturing Facilities. The Manufacturing Facilities group
includes all industrial facilities described above that are not classified as Electric
Generators (i.e., Chemical and Allied Products, Primary Metals Industries, Paper and
Allied Products, Petroleum and Coal Products, and Other Industries).
4.1.2 Number of Facilities and Design Intake Flow Characteristics
Based on the technical survey, EPA estimates that approximately 1,263 facilities in the
major industrial categories would be subject to regulation under the existing facilities
rule. These facilities combine to account for a design intake flow of over 409 billion
gallons per day of cooling water from approximately 1,836 cooling water intake
structures. See Exhibit 4-1 below.
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Chapter 4: Industry Description
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 4-1. Cooling water use in surveyed industries
Facilities potentially regulated
under existing facilities rule (all
existing facilities that withdraw
more than 2 mgd)
Existing electric generators
Existing manufacturers
Estimated
number of
facilities
1,263
671
592
Percent of total
number of
facilities
100
53
47
Estimated total
Design Intake
Flow (mgd)
409,600
370,126
39,473
Percent of
total Design
Intake Flow
100
90
10
Source: Survey Data from Detailed and Short Technical Industry Questionnaires: Phase II Cooling Water Intake
Structures (DON 4-0016F-CBI).
Note: All values are weighted and include facilities identified as baseline closures. Design intake flow for Short Technical
Survey Facilities was imputed from average intake flow.
Exhibit 4-2 shows the geographic distribution of the estimated facilities subject to 316(b).
For illustrative purposes, manufacturers and electric generators are distinctly shown.
Exhibit 4-2. Map of facilities subject to 316(b)
t. x ; jf/o •« <
t «i* : r #T
Legend
• Manufacturer
• Generator
Exhibit 4-3 illustrates the range and distribution of the number of facilities by design
intake flows (DIP).
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 4: Industry Description
Exhibit 4-3. Distribution of facilities by Design Intake Flow
Design Intake
Flow (mgd)
2-10
10-20
20-50
50-100
100-200
200 - 500
500-1,000
> 1,000
Total
Electric generators
Estimated
number of
facilities
37
29
51
56
90
152
145
112
671
Percent of
number of
facilities
5
4
8
8
13
23
22
17
100
Manufacturers
Estimated
number of
facilities
139
95
196
84
44
23
7
3
592
Percent of number
of facilities
24
16
33
14
7
4
1
0.5
100
Source: Survey Data from Detailed and Short Technical Industry Questionnaires: Phase II Cooling Water Intake
Structures (DON 4-0016F-CBI).
Note: All values are weighted and include those facilities identified as baseline closures. Design intake flow for Short
Technical Survey Facilities was imputed from average intake flow.
Exhibit 4-3 shows that the majority of electric generator facilities have a DIF >100 mgd
while the majority of manufacturers have a DIF in the 2 to 50 mgd range.
Exhibit 4-4 shows the estimated total DIF and average intake flow (AIF) for each flow
range shown in Exhibit 4-2. The percent AIF/DIF shows the relative volume of AIF to
DIF for each flow range.
Exhibit 4-4. Relative volumes of Design Intake Flow and Average Intake Flow
Design Intake Flow
(mgd)
2-10
10-20
20-50
50-100
100-200
200 - 500
500-1,000
> 1,000
Total
Electric generators
Total
weighted
DIF (mgd)
178
449
1,745
4,087
12,464
49,946
103,672
197,586
370,126
Total
weighted
AIF (mgd)
71
175
830
2,010
6,042
26,501
61,995
118,970
216,593
Percent
AIF/DIF
40%
39%
48%
49%
48%
53%
60%
60%
59%
Manufacturers
Total
weighted
DIF (mgd)
719
1,322
6,217
5,887
6,355
7,883
4,606
6,484
39,473
Total
weighted
AIF (mgd)
321
667
3,158
3,341
3,043
4,247
2,767
3,696
21,239
Percent
AIF/DIF
45%
50%
51%
57%
48%
54%
60%
57%
54%
Source: Survey Data from Detailed and Short Technical Industry Questionnaires: Phase II Cooling Water Intake
Structures (DON 4-0016F-CBI).
Exhibit 4-4 shows that facilities with larger design flows tend to withdraw a higher
proportion of their design flow on a daily basis and the trend is more pronounced for
electric generators.
Exhibit 4-5 shows design intake flow values by industry type.
4-5
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Chapter 4: Industry Description
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 4-5. Design Intake Flow by industry type
Industry Type
Chemical and
allied products
Primary metals
Paper and allied
products
Petroleum and
coal products
Food products
Other
manufacturing
Total
manufacturers
Electric
generators
Total
Estimated number
of facilities
185
95
227
39
38
7
592
671
1,262
Total Design
Intake Flow (mgd)
12,400
9,444
11,944
3,259
2,073
353
39,473
370,126
409,600
Percent of total
Design Intake Flow
of all facilities
3
2
3
1
0.5
0.1
10
90
100
Average Design
Intake Flow
(mgd)a
126
131
69
96
52
81
95
555
434
a Average based on surveyed facilities. May not be reflective of actual industry-wide average design intake flows.
Source: Survey Data from Detailed and Short Technical Industry Questionnaires: Phase II Cooling Water Intake
Structures (DON 4-0016F-CBI).
Note: All values are weighted and include facilities identified as baseline closures. Design intake flow for Short Technical
Survey Facilities was imputed from average intake flow.
4.1.3 Source Waterbodies
Facilities potentially regulated under the existing facilities rule can be found on all
waterbody types, but are predominantly located on freshwater rivers and streams. Exhibit
4-6 below illustrates the distribution of facilities by waterbody type.
Exhibit 4-6. Distribution of source waterbodies for existing facilities
Source of surface water
Freshwater river or stream
Lake or reservoir
Great Lakes
Estuary or tidal river
Ocean
Total
Electric generators
Estimated
number of
facilities
349
134
48
117
22
671
Percent of
facilities
52
20
7
17
3
100
Manufacturers
Estimated
number of
facilities
454
42
46
39
11
592
Percent of
facilities
77
7
8
7
2
100
Source: Survey Data from Detailed and Short Technical Industry Questionnaires: Phase II Cooling Water Intake
Structures (DON 4-0016F-CBI).
Note: All values are weighted and include those facilities identified as baseline closures.
4-6
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 4: Industry Description
Exhibit 4-7 focuses on facilities located on freshwater rivers and streams. In the 2004
Phase II rule, any freshwater facility whose DIP exceeded 5 percent of its source river's
mean annual flow (MAP) would have been subject to both impingement mortality and
entrainment requirements.32 The exhibit shows the withdrawal volumes for all facilities
that completed a detailed technical questionnaire.
Exhibit 4-7. Facility intake flows as a percentage of mean annual flow
Electric generators
Manufacturers
Intake flow as
a % of MAP
No data
1-5%
5-10%
10-20%
20-40%
40-60%
60-80%
80-100%
>100%
Total > 5%
Total with Data
Intake flow as
a % of MAP
No data
1-5%
5-10%
10-20%
20-40%
40-60%
60-80%
80-100%
>100%
Total > 5%
Total with Data
DIP
No. of
facilities
8
81
24
27
10
3
0
4
8
76
157
% of no.
of fac.
with data
-
51.6%
15.3%
17.2%
6.4%
1.9%
0.0%
2.5%
5.1%
48.4%
100%
No. of
wgtd.
fac.
16
190
58
67
24
7
0
8
16
181
371
% of no.
of wgtd.
fac. with
data
-
51.3%
15.7%
18.1%
6.6%
1.9%
0.0%
2.1%
4.4%
48.7%
100%
DIP
No. of
facilities
4
141
9
9
7
1
2
2
3
33
174
% of no.
of fac.
with data
-
89.8%
5.7%
5.7%
4.5%
0.6%
1.3%
1.3%
1.9%
21.0%
111%
No. of
wgtd.
fac.
10
368
25
23
14
1
3
3
7
76
444
% of no.
of wgtd.
fac. with
data
-
99.1%
6.6%
6.2%
3.7%
0.3%
0.9%
0.9%
2.0%
20.6%
120%
AIF
No. of
facilities
8
112
23
7
4
3
4
0
4
45
157
% of no.
of fac.
with data
-
71.3%
14.6%
4.5%
2.5%
1.9%
2.5%
0.0%
2.5%
28.7%
100%
No. of
wgtd. fac.
16
263
58
17
10
6
8
0
8
108
371
% of no.
of wgtd.
fac. with
data
-
71.0%
15.7%
4.6%
2.7%
1 .6%
2.2%
0.0%
2.2%
29.0%
100%
AIF
No. of
facilities
4
153
7
7
2
3
0
2
0
21
174
% of no.
of fac.
with data
-
97.5%
4.5%
4.5%
1.3%
1.9%
0.0%
1.3%
0.0%
13.4%
111%
No. of
wgtd. fac.
10
400
17
15
4
5
0
3
0
45
444
% of no.
of wgtd.
fac. with
data
-
107.7%
4.6%
4.2%
1 .2%
1.3%
0.0%
0.8%
0.0%
12.0%
120%
Source: Survey Data from Detailed and Short Technical Industry Questionnaires: Phase II Cooling Water Intake Structures
(DON 4-0016F-CBI).
Note: "Wgtd. Fac." and "Wgtd" refers to facility counts or distribution based on estimates using weighting factors
Note: All values are weighted and include those facilities identified as baseline closures.
Note: Extremely large withdrawal percentages may reflect flawed data or may represent facilities that withdraw as much as 100
percent of the waterbody's flow (see, for example, the discussion on Monroe Power Plant in the Case Study Analysis [DCN 4-
0003] in the Phase II docket).
Today's final rule does not include such a requirement, but this analysis shows the relative scale of
withdrawals.
4-7
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Chapter 4: Industry Description
§ 316(b) Existing Facilities Final Rule - TDD
4.1.4 Cooling Water System Configurations
Facilities potentially regulated under the existing facilities rule employ a variety of
cooling water system (CWS) types. Exhibit 4-8 shows the distribution of cooling water
system configurations.
Exhibit 4-8. Distribution of cooling water system configurations
CWS configuration
Once-through
Once-through with
non-recirculating
impoundment
Once-through with
non-recirculating
tower
Recirculating with
tower
Recirculating with
impoundment
Combination
Other
Total
All facilities
Estimated
number of
cwsa
1049
127
44
406
119
167
156
1,704
Percent of
total CWS
62
8
3
24
7
10
9
100
Electric generators
Estimated
number of
CWS
599
67
30
182
64
70
35
912
Percent of
total CWS
66
7
3
20
7
8
4
100
Manufacturers
Estimated
number of
CWS
450
60
14
224
55
97
121
793
Percent of
total CWS
57
8
2
28
7
12
15
100
a Some facilities have more than one cooling water system. Some cooling systems have more than one type of CWS
configuration.
Source: Survey Data from Detailed and Short Technical Industry Questionnaires: Phase II Cooling Water Intake
Structures (DON 4-0016F-CBI).
Note: All values are weighted and include facilities identified as baseline closures.
Exhibit 4-9 shows the distribution of cooling water systems and the waterbody type from
which they withdraw.
Exhibit 4-9. Distribution of facilities by cooling water system and waterbody type
Waterbody
type
Freshwater
stream or river
Lake or
reservoir
Estuary or tidal
river
Ocean
Great Lake
Total
Recirculating
Number
226.7
47
6.1
0
4
284
%of
total
80%
17%
2%
0%
1%
100%
Once-through
Number
461.8
109.3
124.3
33.1
74.4
802
%of
total
58%
14%
16%
4%
9%
100%
Combination
Number
114
19.6
26.3
0
15.9
176
%of
total
65%
11%
15%
0%
9%
100%
Total
Number
803
176
156
33
94
1262
%of
total
64%
14%
12%
3%
7%
100%
Source: Survey Data from Detailed and Short Technical Industry Questionnaires: Phase II Cooling Water Intake
Structures (DCN 4-0016F-CBI).
4-8
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 4: Industry Description
Exhibit 4-10 shows the distribution of cooling water system types at nuclear facilities.
Exhibit 4-10. Distribution of cooling water system configurations at nuclear facilities
by waterbody type
CWS type
Combination
Closed-cycle
Once-through
Waterbody type
Ocean
Estuary or tidal river
Great Lake
Freshwater river
Lake or reservoir
Ocean
Estuary or tidal river
Great Lake
Freshwater river
Lake or reservoir
Ocean
Estuary or tidal river
Great Lake
Freshwater river
Lake or reservoir
Number of facilities
0
0
1
3
4
0
2
3
14
4
5
8
6
5
7
Exhibit 4-10 shows that nuclear facilities (which are virtually always baseload
generators) with closed-cycle or combination cooling systems are most frequently located
on freshwater rivers and lakes. Also, there are no nuclear facilities with closed-cycle
cooling that withdraw from an ocean.
Exhibit 4-11 illustrates the intake structure arrangements for facilities potentially
regulated under the rule.
Exhibit 4-11. Distribution of cooling water intake structure arrangements
Intake arrangement
Canal or channel intake
Bay or cove intake
Submerged shoreline intake
Surface shoreline intake
Submerged offshore intake
Total
Electric generators
Estimated
number of
facilities
185
59
216
212
105
671
Percent of
arrangements
28
9
32
32
16
100
Manufacturers
Estimated
number of
facilities
112
43
179
128
186
592
Percent of
arrangements
19
7
30
22
32
100
Source: Survey Data from Detailed and Short Technical Industry Questionnaires: Phase II Cooling Water Intake
Structures (DON 4-0016F-CBI).
Note: The sum of facilities for each arrangement exceeds the total since some facilities employ multiple intake
arrangements.
Note: All values are weighted and include facilities identified as baseline closures.
4-9
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Chapter 4: Industry Description
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 4-12 illustrates the distribution of cooling water system configurations as a
function of facility age.
Exhibit 4-12. Estimated distribution of cooling water system configurations as a
function of age
CWS age
(Years)
< 10
1 0 to 20
20 to 40
>40
All
CWS
Configuration
Once-through
Recirculating
Combination
Other
Total
Once-through
Recirculating
Combination
Other
Total
Once-through
Recirculating
Combination
Other
Total
Once-through
Recirculating
Combination
Other
Total
Once-through
Recirculating
Combination
Other
Total
Electric generators
Estimated
number of
CWSs
4
9
4
0
17
21
24
1
0
47
224
63
29
3
319
332
21
37
5
396
581
117
71
9
779
Percent of
CWSs
0.5%
1%
1%
0%
2%
3%
3%
0.1%
0%
6%
29%
8%
4%
0.4%
41%
43%
3%
5%
0.7%
51%
75%
15%
9%
1%
100%
Manufacturers
Estimated
number of
CWSs
18
10
16
0
44
27
41
31
3
102
82
36
53
12
183
221
60
101
49
431
348
147
201
64
760
Percent of
CWSs
2%
1%
2%
0%
6%
4%
5%
4%
0.4%
13%
11%
5%
7%
2%
24%
29%
8%
13%
6%
57%
46%
19%
26%
8%
100%
Source: Survey Data from Detailed and Short Technical Industry Questionnaire: (DON 4-0016F-CBI).
Note: Based on detailed technical survey data. Numbers are estimated using weighting factors. Estimated total CWSs do
not match those in Exhibit 1-6 which are based on weighted detailed and short technical survey responses.
Exhibit 4-13 presents the distribution of in-scope facilities by the number of separate
cooling water systems at each facility.
4-10
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 4: Industry Description
Exhibit 4-13. Estimated distribution of in-scope facilities by the number of cooling
water systems
Number of cooling
water systems
1
2
3
4
5 or more*
Total
Electric Generators
Estimated
number of
facilities
506
115
33
12
5
671
Percent of
facilities
75%
17%
5%
2%
1%
100%
Manufacturers
Estimated
number of
facilities
463
103
4
9
12
592
Percent of
facilities
78%
17%
1%
1%
2%
100%
* The largest number of cooling water systems was 7.
Source: Survey Data from Detailed and Short Technical Industry Questionnaire: (DON 4-0016F-CBI).
Exhibit 4-13 shows that both electric generators and manufacturers have a similar
distribution of number of cooling water systems and that the majority use a single CWS.
4.1.5 Design and Operation of Cooling Water Intake Structures
Each CWS may be serviced by more than one cooling water intake structure (CWIS).
Exhibit 4-14 provides an estimate of the number and percent of facilities that have
multiple CWISs.
Exhibit 4-14. Estimated distribution of in-scope facilities by the number of cooling
water intake structures
Number of cooling
water intake
structures
1
2
3
4
5 or more*
Total
Electric generators
Estimated
number of
facilities
450
146
45
16
14
671
Percent of
facilities
67%
22%
7%
2%
2%
100%
Manufacturers
Estimated
number of
facilities
452
101
18
9
12
592
Percent of
facilities
76%
17%
3%
2%
2%
100%
* The largest number of cooling water intake structures was 8.
Source: Survey Data from Detailed and Short Technical Industry Questionnaire: (DON 4-0016F-CBI).
Exhibit 4-14 shows that both electric generators and manufacturers have a similar
distribution of number of CWISs and that the majority of both use a single CWIS.
For those power generators with multiple intake structures, Exhibit 4-15 illustrates the
number of facilities that utilize closed-cycle cooling for at least some portion of the
facility's cooling system (i.e., a "combination" CWS).
4-11
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Chapter 4: Industry Description
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 4-15. Electric generators with multiple CWISs
CWS type
Once-through only
Once-through only
Once-through only
Closed-cycle + once-through
Closed-cycle + once-through
Closed-cycle + once-through
Flow range
< 50 mgd
50-250 mgd
> 250 mgd
< 50 mgd
50-250 mgd
> 250 mgd
Number of facilities
7
35
150
0
2
5
Source: Survey Data from Detailed and Short Technical Industry Questionnaire: (DON 4-0016F-CBI).
Both mesh size and intake velocity affect impingement and entrainment reductions. In
particular, screen mesh size is an important factor affecting impingement and entrainment
rates. Exhibit 4-16 provides a national estimate of the number and percentage of facilities
utilizing different mesh size screens.
Exhibit 4-16. Estimated distribution of screen mesh size
Mesh size (mm)
<5 mm (1/5 in)
> 9. 5-1 9 mm (3/8 -3/4 in)
Other/missing data
Total
Electric generators
Estimated
number of
CWISs
21
885
97
1002
Percent of
CWISs
2%
88%
10%
100%
Manufacturers
Estimated
number of
CWISs
115
347
171
633
Percent of
CWISs
18%
55%
27%
100%
Source: Survey Data from Detailed and Short Technical Industry Questionnaire: (DON 4-0016F-CBI).
Note: Includes data for multiple CWISs and multiple screens at many facilities.
Note: Assumes "other" and "missing" is > 9.
These data show that at the time the technical survey was conducted, only a small
percentage of electric generators utilized fine mesh screens. EPA is aware that since then,
additional facilities have installed fine mesh screens.
Exhibit 4-17 below illustrates the wide range of design intake velocities at facilities
potentially regulated under this rule.
4-12
-------
§ 316(b) Existing Facilities Final Rule - TDD
Chapter 4: Industry Description
Exhibit 4-17. Distribution of cooling water intake structure design through-screen
velocities
Velocity (feet per
second)
0-0.5
0.5-1
1 -2
2-3
3-5
5-7
>7
Total
Average (fps, unweighted)
Median (fps, unweighted)
Electric generators
Estimated
number of
CWIS
148
200
316
162
35
10
23
893
1.9
1.4
Percent of
CWIS
17
22
35
18
4
1
3
100
Manufacturers
Estimated
number of
CWIS
165
85
84
57
27
6
13
436
1.6
1.0
Percent of
CWIS
38
20
19
13
6
1
3
100
Source: Survey Data from Detailed and Short Technical Industry Questionnaire: (DON 4-0016F-CBI).
Note: Based on survey responses that provided data.
Note: The average design through-screen velocity for all surveyed cooling water intake structures (unweighted) is 1.8 feet
per second. The median design through-screen velocity for all surveyed facilities is 1.3 feet per second.
Note: All values are weighted and include those facilities identified as baseline closures.
Exhibit 4-18 provides a national estimate of the number and percentage of cooling water
intake structures by average number of days operating for all intakes for which data was
reported. Data provided is based on a "typical" year for short technical survey facilities
and the year 1998 for the detailed technical survey facilities.
Exhibit 4-18. Estimated distribution of intakes by average of CWIS operating days
Average intake
operating days
< 60 days
60-180 days
180 -270 days
> 270 days
Unknown
Total
Electric generators
Estimated number of
facilities
81
113
81
684
58
1,017
Percent of
facilities
8.0%
11.1%
8.0%
67.2%
5.7%
100.0%
Manufacturers
Estimated number
of facilities
37
23
26
676
56
819
Percent of
facilities
4.6%
2.9%
3.2%
82.6%
6.8%
100.0%
Source: Survey Data from Detailed and Short Technical Industry Questionnaires.
Exhibit 4-18 shows that the intakes for manufacturers tend to operate more days per year
than electric generators. Nearly 75 percent of both types of facilities operate more than
270 days per year. For electric generators, the number of operating days is a component
of the capacity utilization rate (CUR); the other component is the proportion of the total
generating capacity actually generated during the operating period. The number of
operating days also gives an indication of the general amount of operational downtime
4-13
-------
Chapter 4: Industry Description
§ 316(b) Existing Facilities Final Rule - TDD
that may be available to help defray costs of compliance technology construction
downtime.
4.1.6 Existing Intake Technologies
Most facilities potentially regulated under the existing facilities rule have intake
technologies already in place. Exhibit 4-19 illustrates the number of existing facilities
utilizing different types of intake technologies. EPA notes that not all intake technologies
may be sufficient to meet the performance standards or the requirements of the rule.
While not using an intake technology per se, facilities with cooling towers have also been
included in this table to demonstrate the usage of flow reduction as a method to reduce
impingement mortality and entrainment.
Exhibit 4-19. Distribution of intake technologies
Intake technology type
Bar rack or trash rack
Screening technologies
Passive intake technologies
Fish diversion or avoidance system
Fish handling or return system
No Intake technologies
Cooling tower
Total
Electric generators
Estimated
number of
technologies
281
623
130
44
145
6
191
671
Percent of
facilities
42
93
19
7
22
1
28
100
Manufacturers
Estimated
number of
technologies
403
431
205
36
23
14
209
592
Percent of
facilities
68
73
35
6
4
2
35
100
Source: Survey Data from Detailed Industry Questionnaire: Phase II Cooling Water Intake Structures (DON 4-0016F-CBI).
Note: The total number of technologies exceeds the total number of facilities, since many facilities employ multiple intake
technologies.
Note: All values are weighted and include those facilities identified as baseline closures.
4.1.7 Age of Facilities
Exhibit 4-20 shows the age of existing generating units. As discussed in Chapter 5, this
data may not be entirely representative of the actual age of equipment used, as power
plants and manufacturers tend to be long-lived facilities that commonly add new units or
replace existing units.33
As a result, the age of the facility as a whole may not be representative of the age of its units; original
units may have been retired or replaced.
4-14
-------
§ 316(b) Existing Facilities Final Rule - TDD
Chapter 4: Industry Description
Exhibit 4-20. Age of electric generating units by fuel type
Unit age
(years)
>60
51-60
41-50
31-40
11-30
<10
Total
Coal
Units
22
275
271
218
167
9
962
%
2
29
28
23
17
1
Natural gas
Units
11
119
137
276
121
180
844
%
1
14
16
33
14
21
Nuclear
Units
0
0
0
49
49
0
98
%
0
0
0
50
50
0
Oil
Units
8
27
123
241
41
16
456
%
2
6
27
53
9
4
Other
Units
0
6
1
0
13
3
23
%
0
26
4
0
57
13
Source: El A Form 860 Database, year 2008 data.
Note: Data was not available for approximately 34 facilities.
As shown in Exhibit 4-20, over eighty percent of the coal-fired units are at least 30 years
of age and more than 31 percent of coal units are at least 50 years of age. Natural gas
facilities tend to be much newer and most nuclear powered units continue to operate
under a recently renewed 20 year operating license or are in the process of seeking such
renewals.34
4.1.8 Water Reduction Measures at Manufacturers
During EPA's site visits to manufacturing facilities, EPA noted many flow reduction
and/or water reuse practices being employed. Flow reductions were demonstrated
through process innovations, internal audits and leak checks, reengineering to capture lost
resources (e.g., water, heat), water reuse or conservation initiatives, process changes as a
result of effluent limitations guideline (ELG) requirements, and other similar activities.
EPA also reviewed specific ELG requirements and other incentive programs to identify
water reduction requirements and approaches. A summary of the findings is presented
below.
Site Visits
An overview of flow reduction information from the manufacturing site visits is provided
in Exhibit 4-21 below.35
34 As discussed in DCN 10-6876, there are indications that some nuclear units may operate well beyond the
initial projections for useful life.
35 For a complete discussion of EPA's site visits, see Chapter 2 of this TDD.
4-15
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Chapter 4: Industry Description
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 4-21. Flow reduction at sites visited by EPA
Manufacturing site
ArcelorMittal — Indiana Harbor
Cargill — Hammond
Dow Chemical — Louisiana
Operations (Plaquemine)
Dow Chemical — St. Charles
Operations (SCO)
Sunoco — Marcus Hook
Sunoco — Philadelphia
US Steel— Gary
Valero — Delaware City
Notes on intake flow reductions
East side recirculates an estimated 569 mgd via underground
tunnel system and also has extensive cooling tower usage. West
side uses a mix of once-through and CCRS, with power plant using
most of once-through flow.
Reuses 1 0-1 5 percent of cooling water as process water. Other
Cargill sites reuse higher percentages. Cargill formed a corporate
water reduction team and has a company-wide goal of reducing
water use by 5% by 2012.
60 percent of the heat load is processed through cooling towers,
leading to a commensurate reduction in flow.
4 percent of the heat load is processed through cooling towers.
Historical intake capacity (DIP) is 134 mgd, permitted limit (from
DRBC) is 43 mgd, and AIF is 1 7 mgd. Significant use of cooling
towers.
Converted several process lines to CCRS in the 1980s and has
significant water reuse and use of cooling towers. Actual flow
reductions not available, but AIF is very low.
A cooling tower recirculates approximately 148 mgd. Blast furnaces
and steel shop also converted to CCRS.
Added dry and wet cooling systems to new process lines.
Withdrawals are limited by DRBC; added towers in 1990s to
expand production without increasing heat load.
Effluent Limitations Guidelines (ELGs)
In addition to conducting site visits to observe water reduction practices, EPA also
researched ELGs to identify incentives and requirements for water reduction. ELGs are
technology-based regulations and are intended to represent the greatest pollutant
reductions that are economically achievable for a particular industrial category. As part of
the regulatory development process that EPA uses in developing technology-based ELGs
for industrial categories, EPA first gathers extensive information and data on the
industry's processes, discharge characteristics, technologies and practices used to treat,
minimize, or prevent wastewater discharges, as well as economic information.
Pollution prevention, management, and minimization practices have become a greater
focus in the ELG development process, especially since EPA has been establishing ELGs
for industrial categories and facilities that are not typical production facilities (i.e., airport
deicing, construction and development, and concentrated aquatic animal production
(aquaculture) facilities among others). EPA is also required by the CWA to reexamine
existing ELGs to ensure they are still representative of the industrial category and meet
the current levels of treatment technology (BAT, BCT, BPT, NSPS, PSES, and PSNS).
For those industrial categories whose ELGs are being revised, new pollution prevention
practices are thoroughly examined in addition to the traditional end-of-pipe treatment
technologies.
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 4: Industry Description
As part of developing ELGs for various industry sectors, EPA typically assesses water
use, technologies in place, and industry trends. The documents developed by EPA as part
of this process provide the most accurate description of historic changes in water
withdrawals on an industry or process/subcategory level.
For example, the factors used in developing the subcategories for the revised iron and
steel ELG included:
• Age of equipment and facilities;
• Location;
• Size of the site;
• Manufacturing processes employed;
• Wastewater characteristics; and
• Non-water quality environmental impacts
Of the areas mentioned above, EPA determined that manufacturing processes and the
resultant wastewater characteristics were the most significant factors for possible
subcategorization of the industry. Detailed discussions of water use, pollutants generated,
and production-normalized flow rates are found throughout the TDD for the iron and
steel ELG. As part of the iron and steel regulatory development effort, EPA examined the
following:
• In-process technologies and process modifications;
• Process water recycle technologies;
• Process water discharge flow rates;
• End-of-pipe wastewater treatment technologies; and
• Treated process wastewater effluent quality
Section 8 of the iron and steel TDD provides examples of wastewater minimization
technologies.36 For example, high-rate recycling can recycle approximately 95 percent or
more from a process for reuse. As with other metal processes, countercurrent cascade
rinsing can reduce water use by up to 90 percent while other discussions demonstrate
process modifications that can result in the reduction of process water volumes by either
extending the amount of time water can be utilized within a process or reducing the
volume of process water required.
In the metal products and machinery ELG, a section of the TDD discusses pollution
prevention practices and wastewater reduction technologies.37 EPA estimated in the
TDD, Section 8, that the use of flow reduction technologies can reduce water use by as
much as 50 to 90 percent at applicable facilities.
36 Iron and Steel Manufacturing Point Source Category Final Rule: Development Document. EPA 821-R-
02-004. Available at http://water.epa.gov/scitech/wastetech/guide/ironsteel/index.cfm.
37 Effluent Guidelines, Metal Products and Machinery: Final Rule Development Document. EPA-821-B-
03-001. Available at http://water.epa.gov/scitech/wastetech/guide/mpm/tdd index.cfm.
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Chapter 4: Industry Description § 316(b) Existing Facilities Final Rule - TDD
In the organic chemicals, plastics, and synthetic fibers TDD, water conservation and
reuse technologies are described although no estimates in reducing flow volumes are
presented.38
Economic considerations play a large role in the efficient utilization of water within
many industrial sectors. Recovering chemicals from waste streams can lower chemical
costs but can also greatly reduce treatment expenses for wastewater discharges. In
addition, efficient use of water within processes, cooling water for example, can improve
process efficiencies throughout the rest of the facility (heated water can then be utilized
by other processes in the facility). Leaks and spills at industrial facilities not only present
productivity issues, but can possibly lead to health and safety issues.
Incentive Programs
EPA has also developed voluntary incentive programs for facilities that wish to go
beyond the minimum regulatory requirements established in the applicable ELG. An
example is the Voluntary Advanced Technology Incentives Program (VATIP)
established as part of the revised National Emissions Standards for Hazardous Air
Pollutants for Source Category: Pulp and Paper Production; Effluent Limitations
Guidelines, Pretreatment Standards, and New Source Performance Standards: Pulp,
Paper, and Paperboards (also known as the Pulp and Paper Cluster Rule). EPA
established the VATIP to encourage facilities subject to the Bleached Papergrade Kraft
and Soda Subcategory to achieve greater pollutant reductions by implementing pollution
prevention controls. Pulp and paper mills that enroll in the VATIP receive additional time
to comply with the regulation and have reduced monitoring requirements, among other
incentives.
The VATIP comprises three tiers that represent increasingly more effective levels of
environmental protection. Mills enrolled in the program have extended compliance dates
in which to meet the requirements for each tier. Facilities that enter in to VATIP are
required to prepare a milestone plan that reflects how the mill will achieve the limitations
for their selected tier. This milestone plan can assist permitting authorities in developing
interim limitations and requirements in NPDES permits. EPA established three phases to
measure a facility's progress in complying with permit requirements and to ensure
compliance with the tier limitations. The three phases include:
• Initial limitations;
• Intermediate milestones; and
• Ultimate limitations
The initial limitations must reflect either the existing effluent quality or the current
technology-based limits in the mill's current permit, whichever is more stringent. This is
for those pollutants (or flows) that are part of the VATIP. Under the Clean Water Act
(CWA), facilities must comply with best available technology economically achievable
(BAT) effluent limitations promulgated after March 31, 1989 immediately (CWA 40
38 Development Document for 1987 Effluent Limitations Guidelines and Standards for OCPSF. EPA 440-
1-87-009. Available at http://water.epa.gov/scitech/wastetech/guide/ocpsf/index.cfm.
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 4: Industry Description
CFR 301(b)(2)). Under the VATIP, the limitations for the various tiers eventually
become the BAT limits for those facilities. The pulp and paper ELG requires immediate
compliance with ELG limits, but only if they have become enforceable BAT limits.
The intermediate milestones include the establishment of intermediate BAT limitations
and the possible inclusion of interim milestones reflective of the facility moving forward
to achieve the required limitations for the respective tier.
The ultimate limitations require the facility to meet the final effluent limitations for the
applicable tier no later than the date specified in the regulation.
In addition to the time to allow participating facilities to meet the more stringent effluent
limits, facilities participating in the VATIP is the reduction in monitoring requirements.
Based on the tier chosen, monitoring frequencies are reduced once the facility has
demonstrated it has reached the intermediate milestones (stage 2).
4.1.9 Land-based Liquefied Natural Gas Facilities
EPA's research also indicates that there are five existing land-based liquefied natural gas
(LNG) facilities in the United States, all on the East coast. LNG facilities may withdraw
hundreds of mgd of seawater for warming (re-gasification). Some existing LNG facilities
may withdraw water and use 25 percent or more for cooling purposes. As discussed in the
preamble, EPA has not identified a uniformly applicable and available technology for
minimizing impingement and entrainment mortality at these facilities. However,
technologies may be available for some existing LNG facilities. LNG facilities that
withdraw any volume of water for cooling purposes would be subject to site-specific, best
professional judgment BTA determinations under the proposed rule.
4.2 Electricity Industry
The electricity industry is made up of three major functional service components or
sectors: generation, transmission, and distribution. Each of these terms is defined as
follows (Beamon, 1998; Joskow, 1997):
• The generation sector includes power plants that produce, or "generate,"
electricity.39 Electric energy is produced using a specific generating technology,
for example, internal combustion engines and turbines. Turbines can be driven by
wind, moving water (hydroelectric), or steam from fossil fuel-fired boilers or
nuclear reactions. Other methods of power generation include geothermal or
photovoltaic (solar) technologies.
• The transmission sector can be thought of as the interstate highway system of the
business - the large, high-voltage power lines that deliver electricity from power
plants to distribution centers using a complex system. Transmission requires:
interconnecting and integrating a number of generating facilities into a stable,
synchronized, alternating current (AC) network; scheduling and dispatching all
connected plants to balance the demand and supply of electricity in real time; and
39 The terms "plant" and "facility" are used interchangeably throughout this profile and document.
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Chapter 4: Industry Description § 316(b) Existing Facilities Final Rule - TDD
managing the system for equipment failures, network constraints, and interaction
with other transmission networks.
• The distribution sector can be thought of as the local delivery system - the
relatively low-voltage power lines that take power from a distribution center and
bring it to homes and businesses. Electricity distribution relies on a system of
wires and transformers along streets and underground to provide electricity to the
ultimate end user: residential, commercial, and industrial consumers. The
distribution system involves both the provision of the hardware (for example,
lines, poles, transformers) and a set of retailing functions, such as metering,
billing, and various demand management services.
Of the three industry sectors, only electricity generation uses cooling water and is,
therefore, subject to section 316(b) regulations.
4.2.1 Domestic Production
This section presents an overview of U.S. generating capacity and electricity generation
for the year 2007.40 The rating of a generating unit is a measure of its ability to produce
electricity.41 Generator ratings are expressed in megawatts (MW). Nameplate capacity
and net capability are the two common measurements (U.S. DOE, 2000a) and are defined
as follows:
Nameplate capacity is the full-load continuous output rating of the generating unit under
specified conditions, as designated by the manufacturer.
Net capability is the steady hourly output that the generating unit is expected to supply to
the system load, as demonstrated by test procedures. The capability of the generating unit
in the summer is generally less than in the winter due to higher ambient-air and cooling-
water temperatures, which cause generating units to operate less efficiently. The
nameplate capacity of a generating unit is generally greater than its net capability.
Exhibit 4-22 shows the net US generating capacity from 2000 to 2011 by fuel type.
40 The most recent analysis was for data from 2007. EPA has updated this information since the 2002
proposed Phase II rule, which used data from 1999.
41 The numbers presented in this section are capability for utility facilities and capacity for nonutilities. For
convenience purposes, this section will refer to both measures as "capacity."
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 4: Industry Description
Exhibit 4-22. Existing generating capacity by energy source (2000 to 2009)
Net Summer Generating Capacity by Fuel Type
±i
TO 200,000
Q.
3
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
^Coal ^^^Petroleum —fr^Natural Gas
^Hydroelectric I Wind Other
Source: DOE 2013. Table 1.2.
Note 1: Data reflects summer month capacity, during peak consumption.
Note 2: "Other" is a combination of the following: other gases (e.g., blast furnace gas, propane gas); solar; wood; and
other renewables.
Exhibit 4-22 shows that the majority of capacity increases over the past 10 years have
been fueled by natural gas, with a minor increase in wind power in recent years.
4.2.2 Prime Movers
Electric power plants use a variety of prime movers to generate electricity. The type of
prime mover used at a given facility is determined based on the type of load the facility is
designed to serve, the availability of fuels, and energy requirements. Most prime movers
use fossil fuels (coal, petroleum, and natural gas) as an energy source and employ some
type of turbine to produce electricity. The six most common prime movers are (U.S.
DOE, 2000a):
• Steam Turbine: Steam turbine or "steam electric" units require a fuel source to
boil water and produce steam that drives the turbine. Either the burning of fossil
fuels or a nuclear reaction can be used to produce the heat and steam necessary to
generate electricity. These units are often baseload units that are run continuously
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Chapter 4: Industry Description § 316(b) Existing Facilities Final Rule - TDD
to serve the constant load required by the system. Steam electric units generate the
majority of electricity produced at power plants in the U.S.42
Gas Combustion Turbine: Gas turbine units burn a combination of natural gas
and distillate oil in a high pressure chamber to produce hot gases that are passed
directly through the turbine. Units with this prime mover are generally less than
100 megawatts in size, less efficient than steam turbines, and used forpeakload
operation serving the highest daily, weekly, or seasonal loads. Gas turbine units
have quick startup times and can be installed at a variety of site locations, making
them ideal for peak, emergency, and reserve-power requirements. These units do
not use a steam loop and do not use cooling water; waste heat is discharged to the
atmosphere.
Combined Cycle Turbine: Combined cycle units utilize both steam and gas
turbine prime mover technologies to increase the efficiency of the gas turbine
system. After combusting natural gas in gas turbine units, the hot gases from the
turbines are transported to a waste-heat recovery steam boiler where water is
heated to produce steam for a second steam turbine.3 The steam may be produced
solely by recovery of gas turbine exhaust or with additional fuel input to the steam
boiler. The combination of a gas turbine and steam turbine process results in a
generating system that is much more efficient than either alone. Combined cycle
generating units have generally been used for intermediate loads but may be used
as baseload units when natural gas prices are favorable. These units use a steam
loop in the steam turbine portion of the process and use cooling water to convert
the steam back to water and use much less cooling water per MW generated that
steam turbine units.
Internal Combustion Engines: Internal combustion engines contain one or more
cylinders in which fuel is combusted to drive a generator. These units are
generally about 5 megawatts in size, can be installed on short notice, and can
begin producing electricity almost instantaneously. Like gas turbines, internal
combustion units are generally used only for peak loads. These units do not use a
steam loop and do not use cooling water; waste heat is discharged to the
atmosphere.
Water Turbine: Units with water turbines, or "hydroelectric units," use either
falling water or the force of a natural river current to spin turbines and produce
electricity. These units are used for all types of loads. These units do not use a
steam loop and do not use cooling water, as they typically do not generate excess
waste heat.
Other Prime Movers: Other types of prime movers include binary cycle turbine
(geothermal), photovoltaic (solar), wind turbine, and fuel cell prime movers. The
contribution of these prime movers is small relative to total power production in
the U.S., but the role of these prime movers may expand in the future because
recent legislation includes incentives for their use. Generally, with the exception
42 The steam is contained in a steam loop that is separate from the cooling water system and is, therefore,
not the focus of this rule. Cooling water is used to convert steam back to water.
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 4: Industry Description
of binary cycle turbines, these movers do not generate excess waste heat. Binary
cycle turbines generally use cooling towers to dissipate waste heat.
Exhibit 4-23, which is based on DOE's Form EIA-860, provides data on existing power
generating plants by prime mover. This exhibit includes all facilities in the electric power
industry (i.e., not just facilities subject to 316(b)) that have at least one non-retired unit
and that submitted Form EIA-860 (Annual Electric Generator Report) in 2007.43 For this
analysis, EPA classified facilities as "steam turbine" or "combined cycle" if they had at
least one generating unit of that type; facilities with both steam turbine- and combined
cycle-based capacity were classified by the largest capacity generating unit. Facilities that
had no steam electric units were classified under the prime mover of the largest capacity
generating unit.
Section 316(b) is only relevant for electric generators that use cooling water. However, not
all prime movers require cooling water. Only prime movers with a steam-electric
generating cycle use large enough amounts of cooling water to fall under the scope of the
proposed rule. EPA identified the two types of prime movers (steam turbine and combined
cycle steam turbine) that constitute the steam electric prime movers of interest.
44
Using this list of steam electric prime movers and DOE's Annual Electric Generator
Report (which collects data to create an annual inventory of utilities and operating status
of units), EPA identified the facilities that have at least one generating unit with a steam
electric prime mover. The rest of this profile will focus on the generating plants with a
steam electric prime mover (i.e., steam turbine or combined cycle).
Exhibit 4-23. Number of existing utility and nonutility facilities by
prime mover, 2007
Prime mover
Steam turbine
Combined cycle
Gas turbine
Internal combustion
Hydroelectric
Other
Total
Number of facilities
1,349
453
834
1,005
1,368
365
5,374
B Facilities are listed as steam electric if they have at least one steam electric generating unit.
b Facility counts are weighted estimates generated using the original 316(b) survey weights.
Sources: U.S. EPA, 2000; U.S. DOE, 2007.
43 Note that EPA's technology assessments and compliance cost estimates are based upon data that EPA
collected through industry questionnaires. This technology data represents the year 2000. Since EPA has
not collected any new information on intake technologies, intake flows, etc. for the existing facilities
proposed rule, EPA is continuing to use the 2000 questionnaire data for some analyses as it reflects the best
information available. However, because more recent information was available through existing sources,
EPA conducted the analysis using 2007 data to more accurately account for possible impacts. As a result,
some of the information presented in this chapter reflects the year 2000 while other reflects the year 2007.
44 EIA identifies 11 other categories of prime mover, but these categories are not subject to 316(b).
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Chapter 4: Industry Description
§ 316(b) Existing Facilities Final Rule - TDD
4.2.3 Steam Electric Generators
Exhibit 4-24 provides summary data concerning the number of utilities/operators, number
of plants, generating units, and total nameplate capacity. The table provides information
for the industry as a whole, for the steam electric part of the industry, and for the part of
the industry potentially subject to the existing facilities rule.
Exhibit 4-24. Summary of 316(b) electric power facility data
Utilities or operators11
Plantsd
Units8
Nameplate capacity (MW)
Total'
2,537
5,374
17,250
1,072,497
Steam electric'
Number
1,158
1,805
4,828
790,690
% of Total
46%
34%
28%
74%
316(b)b'c
Number
233
559
2,132
480,388
% of Total
9%
10%
12%
45%
a Data are for regulated and non-regulated entities.
b Number of units and capacity include steam and non-steam units and capacity, respectively, at 316(b) electric power
facilities.
0 Number of plants, number of units, and capacity are weighted estimates and are generated using the original 316(b)
survey weights.
d Utilities/operators and plants are listed as steam electric if they have at least one non-retired steam electric unit.
e Total number of units includes non-steam generating units at facilities previously considered for the 316(b) regulation
that have retired all of their steam generating units. Because these facilities no longer have steam operations they are
excluded from the currently analyzed 316(b) universe.
f Estimates exclude facilities that have retired all of their operations - steam and non-steam - according to the 2010 base-
case IPM run.
From the universe of facilities with a steam electric prime mover and based on data
collected from EPA's industry technical questionnaires and the compliance requirements
for the final rule, EPA has identified 544 facilities to which the proposed rule is expected
to apply.45 All of these facilities are in the set of 554 facilities that were expected to
comply with the suspended 2004 Phase II Final Rule and 117 electric generators with
design intake flow between 2 and 50 mgd excluded from the 2006 Phase III Final Rule;
however, based on 2007 EIA data and IPM data, a total of 93 of the 671 Phase II and
Phase III facilities will have retired by 2012.46 In addition, 19 coastal facilities are subject
to the California "Policy on the Use of Coastal and Estuarine Waters for Power Plant
Cooling" And 36 facilities located in the State of New York where requirements are at
least as stringent the final rule47 Exhibit 4-25 provides a summary of the estimated
45 EPA developed the estimates of the number and characteristics of facilities expected to be within the
scope of the rule using the facility sample weights that were developed for the suspended 2004 Phase II
rule and the 2006 Phase III Rule. These weights provide comprehensive estimates of the total number of in-
scope facilities based on the full set of facilities sampled in EPA's industry questionnaires. This estimate
includes baseline closures. See the preamble and the EA for further discussion of the sample weights used
in this analysis.
46 Individual values do not sum to reported totals due to rounding as the result of the application of
statistical weights.
47 As described in the EA, these 19 California and 36 New York facilities were not included in the
economic analysis for the rule, as they are subject to requirements under each state's cooling water policy,
which contains similar or more stringent requirements to the final rule.
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 4: Industry Description
number of facilities considered in the economic analysis under previous and current
316(b) regulation development.
Exhibit 4-25. Number of 316(b) regulated facilities
Phase ll/lll
EIA-Retiredb'c
IPM-Retiredb
Coastal CA
New York
Currently Analyzed
Unweighted
Phase II
543
41
31
17
29
454
Phase III
113
11
8
0
4
94
Total
656
52
39
17
33
548
Weighted3
Phase II
554
43
31
19
31
461
Phase III
117
11
8
0
4
98
Total
671
54
39
19
36
559
a Facility counts generated using the original 316(b) survey weights.
b A facility is considered retired if it no longer has any steam operations even though it may still operate non-steam units.
0 Includes facilities that have already retired and those that will do so before 2012 (i.e., the rule promulgation).
Sources: U.S. EPA, 2000; U.S. DOE, 2007 (GenY07); U.S. EPA Analysis, 2010.
Exhibit 4-26 presents the estimated number of 316(b) facilities by fuel type and prime
mover category.
Facilities have multiple generating units and each unit uses only one type of prime
mover. However, many facilities operate units with different types of prime movers. EPA
estimates that 12 of the 525 steam turbine facilities also operate combined cycle
generating units and that 10 of the 33 combined cycle facilities also operate steam turbine
generating units. The data shown in Exhibit 4-24 are based on total capacity by prime
mover type and do not necessarily indicate which prime mover type predominates with
regard to annual power generation.
Exhibit 4-26. 316(b) electric power facilities by plant type and prime mover
Plant type3
Coal steam
Gas
Nuclear
Oil
Other steam
Total steam
Combined cycle
Total
Prime mover
Steam turbine
Steam turbine
Steam turbine
Steam turbine
Steam turbine
Steam turbine
Combined cycle
Number of 316(b) electric
generators'3'0
342
73
56
29
25
525
33
559
a Facilities are listed as steam electric if they have at least one steam electric generating unit.
b Facility counts are weighted estimates generated using the original 316(b) survey weights.
0 Individual values do not sum to reported total due to rounding as the result the application of statistical weights.
Sources: U.S. EPA, 2000; U.S. DOE, 2007 (GenY07); U.S. EPA Analysis, 2010
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Chapter 4: Industry Description
§ 316(b) Existing Facilities Final Rule - TDD
4.3 Manufacturers
4.3.1 Electric Generation at Manufacturers
Some manufacturing facilities also produce electricity (cogeneration). According to data
from the 316(b) questionnaire, 164 manufacturing facilities responded that they had
produced electricity in 1996, 1997, or 1998.48 One hundred eleven (111) facilities
responded that they did not generate electricity during the survey period. Twelve (12)
facilities did not respond to the question.
Exhibit 4-27 shows the proportion of the 38 manufacturers that use coal as their primary
fuel source.
Exhibit 4-27. Manufacturers with coal-fired generation
Total facility coal-fired generation
capacity (MW)
0-25
25-50
50-100
100-200
>200
Total
Number of facilities
15
8
9
4
2
38
The six largest manufacturers (i.e., those with a generating capacity above 100MW) came
from 5 industry sectors: steel works (SIC 3312), iron ore (1011), electric services/non-
ferrous metals (4911/3339), chemical (2800), and sanitary paper (2676).
4.4 Glossary
Baseload: The minimum amount of electric power delivered or required over a given
period of time at a steady rate.
Baseload Generating Unit: A baseload generating unit is normally used to satisfy all or
part of the minimum or base load of the system and, as a consequence, produces
electricity at an essentially constant rate and runs continuously. Baseload units are
generally the newest, largest, and most efficient of the three types of units.
(http://www.eia.doe.gov/cneaf/electricitv/page/prim2/chapter2.html)
Capacity Utilization Rate: The ratio between the average annual net generation of power
by the facility (in MWh) and the total net capability of the facility to generate power (in
MW) multiplied by the number of hours during a year.
48 Answered yes to Question 15(a) of the 3 l(6)b detailed industry questionnaire for manufacturers, which
requested information on whether the facility generated electricity during the time period covered by the
survey.
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 4: Industry Description
Combined cycle: An electric generating technology in which electricity is produced from
otherwise lost waste heat exiting from one or more gas (combustion) turbines. The
exiting heat is routed to a conventional boiler or to heat recovery steam generator for
utilization by a steam turbine in the production of electricity. This process increases the
efficiency of the electric generating unit.
Combined cycle Unit: An electric generating unit that consists of one or more
combustion turbines and one or more boilers with all or a portion of the required energy
input to the boiler(s) provided by the exhaust gas of the combustion turbine(s).
Distribution: The delivery of energy to retail customers (including homes, businesses,
etc.).
Distribution System: The portion of an electric system that is dedicated to delivering
electric energy to an end user.
EIA: The Energy Information Administration (EIA), created by Congress in 1977, is a
statistical agency of the U.S. Department of Energy.
Electricity Available to Consumers: Power available for sale to customers.
Approximately 8 to 9 percent of net generation is lost during the transmission and
distribution process.
Gas Turbine Plant: A plant in which the prime mover is a gas turbine. A gas turbine
typically consisting of an axial-flow air compressor and one or more combustion
chambers, where liquid or gaseous fuel is burned and the hot gases are passed to the
turbine and where hot gases expand to drive the generator and are then used to run the
compressor.
Generation: The process of producing electric energy or the amount of electric energy
produced by transforming other forms of energy, commonly expressed in kilowatt-hours
(kWh) or megawatt-hours (MWh).
Gross Generation: The total amount of electric energy produced by the generating units
at a generating station or stations, measured at the generator terminals.
Internal Combustion Plant: A plant in which the prime mover is an internal combustion
engine. An internal combustion engine has one or more cylinders in which the process of
combustion takes place, converting energy released from the rapid burning of a fuel-air
mixture into mechanical energy. Diesel or gas-fired engines are the principal fuel types
used in these generators. The plant is usually operated during periods of high demand for
electricity.
Kilowatt (kW): One thousand watts (W).
Kilowatt-hour (kWh): One thousand watt-hours (Wh).
Megawatt (MW): One thousand kilowatts (kW).
Megawatt-hour (MWh): One thousand kilowatt-hours (kWh)
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Chapter 4: Industry Description § 316(b) Existing Facilities Final Rule - TDD
Nameplate Capacity: The amount of electric power delivered or required for which a
generator, turbine, transformer, transmission circuit, station, or system is rated by the
manufacturer.
Net Capacity (Capability): The amount of electric power delivered or required for which
a generator, turbine, transformer, transmission circuit, station, or system is rated by the
manufacturer, exclusive of station use, and unspecified conditions for given time interval.
Net Generation: Gross generation minus plant use from all electric utility owned plants.
The energy required for pumping at a pump storage plant is regarded as plant use and
must be deducted from the gross equation.
Nonutility Power Producer: A corporation, person, agency, authority, or other legal
entity or instrumentality that owns electric generating capacity and is not an electric
utility. Nonutility power producers include qualifying cogenerators, qualifying small
power producers, and other nonutility generators (including independent power
producers) without a designated franchised service area that do not file forms listed in the
Code of Federal Regulations, Title 18, Part 141.
(http://www.eia.doe.gov/emeu/iea/glossary.html)
Peakload: The maximum load during a specified time period.
Peakload Generating Unit: A peakload generating unit, normally the least efficient of
the three unit types, is used to meet requirements during the periods of greatest, or peak,
load on the system, (http://www.eia.doe.gov/cneaf/electricity/page/prim2/chapter2.html)
Prime Movers: The engine, turbine, water wheel or similar machine that drives an
electric generator; or, for reporting purposes, a device that directly converts energy to
electricity directly (e.g., photovoltaic solar, and fuel cell(s)).
Regulated Entity: For the purpose of EIA's data collection efforts, entities that either
provide electricity within a designated franchised service area and/or file forms listed in
the Code of Federal Regulations, Title 18, Part 141 are considered regulated entities. This
includes investor-owned electric utilities that are subject to rate regulation, municipal
utilities, Federal and State power authorities, and rural electric cooperatives. Facilities
that qualify as cogenerators or small power producers under the Public Utility Regulatory
Power Act (PURPA) are not considered regulated entities.
Reliability: Electric system reliability has two components: adequacy and security.
Adequacy is the ability of the electric system to supply customers at all times, taking into
account scheduled and unscheduled outages of system facilities. Security is the ability of
the electric system to withstand sudden disturbances, such as electric short circuits or
unanticipated loss of system facilities. The degree of reliability maybe measured by the
frequency, duration, and magnitude of adverse effects on consumer services.
(http://www.eia.gov/cneaf/electricity/page/glossary.html)
Steam Electric Power Plant: A plant in which the prime mover is a steam turbine. The
steam used to drive the turbine is produced in a boiler where fossil fuels are burned.
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 4: Industry Description
Transmission: The movement or transfer of electric energy over an interconnected group
of lines and associated equipment between points of supply and points at which it is
transformed for delivery to consumers, or is delivered to other electric systems.
Transmission is considered to end when the energy is transformed for distribution to the
consumer
Utility: A corporation, person, agency, authority, or other legal entity or instrumentality
that owns and/or operates facilities within the United States, its territories, or Puerto Rico
for the generation, transmission, distribution, or sale of electric energy primarily for use
by the public, with a dedicated service area, and files forms listed in the Code of Federal
Regulations, Title 18, Part 141. Facilities that qualify as cogenerators or small power
producers under the Public Utility Regulatory Policies Act (PURPA) are not considered
electric utilities, (http://www.eia.doe.gov/emeu/iea/glossary.html)
Water Turbine: A unit in which the turbine generator is driven by falling water.
4.5 References
Beamon, J.A. 1998. Competitive Electricity Prices: An Update. From the Phase I Rule
Record. DCN 1-2110-EA.
Joskow, P. L. 1997. Restructuring, Competition and Regulatory Reform in the U.S.
Electricity Sector. DCN1-2118-EA.
U.S. Department of Energy (U. S. DOE). 2012. Energy Information Administration
(EIA). Electric Power Annual 2011. Released: January 2013. Table 1.2 at:
http://www.eia.gov/electricity/annual/
U.S. Department of Energy (U.S. DOE). 2007. Form EIA-860 (2007). Annual Electric
Generator Report.
U.S. Department of Energy (U.S. DOE). 2002. Energy Information Administration
(EIA). Status of State Electric Industry Restructuring Activity as of March 2002.
At: http://www.eia.gov/electricity/policies/restructuring/restructure elect.html.
U.S. Department of Energy (U.S. DOE). 2001. Energy Information Administration
(EIA). Annual Energy Outlook 2002 With Projections to 2020. DOE/EIA-
0383(2002). December 2001.
U.S. Department of Energy (U.S. DOE). 2000a. Energy Information Administration
(EIA). Electric Power Industry Overview. At:
http://www.eia.doe.gov/cneaf/electricity/page/prim2/toc2.html.
U.S. Department of Energy (U. S. DOE). 2000b. Energy Information Administration
(EIA). Electric Power Annual 1999 Volume I. DOE/EIA-0348(99)/1.
U.S. Department of Energy (U. S. DOE). 2000c. Energy Information Administration
(EIA). Electric Power Annual 1999 Volume II. DOE/EIA-0348(99)/2.
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Chapter 4: Industry Description § 316(b) Existing Facilities Final Rule - TDD
U.S. Department of Energy (U.S. DOE). 1999a. Form EIA-860A (1999). Annual Electric
Generator Report - Utility.
U.S. Department of Energy (U.S. DOE). 1999b. Form EIA-860B (1999). Annual Electric
Generator Report - Nonutility.
U.S. Department of Energy (U.S. DOE). 1999c. Form EIA-861 (1999). Annual Electric
Utility Data.
U.S. Department of Energy (U.S. DOE). 1999d. Form EIA-759 (1999). Monthly Power
Plant Report.
U.S. Department of Energy (U.S. DOE). 1998a. Energy Information Administration
(EIA). Electric Power Annual 1997 Volume I. DOE/EIA-0348(97/1).
U.S. Department of Energy (U.S. DOE). 1998b. Energy Information Administration
(EIA). Electric Power Annual 1997 Volume II. DOE/EIA-0348(97/1).
U.S. Department of Energy (U.S. DOE). 1998c. Form EIA-861 (1998). Annual Electric
Utility Data.
U.S. Department of Energy (U.S. DOE). 1996a. Energy Information Administration
(EIA). Electric Power Annual 1995 Volume I. DOE/EIA-0348(95)/1.
U.S. Department of Energy (U.S. DOE). 1996b. Energy Information Administration
(EIA). Electric Power Annual 1995 Volume II. DOE/EIA-0348(95)/2.
U.S. Department of Energy (U. S. DOE). 1996c. Energy Information Administration
(EIA). Impacts of Electric Power Industry Restructuring on the Coal Industry. At:
http://www.eia.doe.gov/cneaf/electricity/chg str fuel/html/chapterl.html.
U.S. Department of Energy (U.S. DOE). 1995a. Energy Information Administration
(EIA). Electric Power Annual 1994 Volume I. DOE/EIA-0348(94/1).
U.S. Department of Energy (U.S. DOE). 1995b. Energy Information Administration
(EIA). Electric Power Annual 1994 Volume II. DOE/EIA-0348(94/1).
U.S. Environmental Protection Agency (U.S. EPA). 2000. Section 316(b) Industry
Survey. Detailed Industry Questionnaire: Phase II Cooling Water Intake Structures
and Industry Short Technical Questionnaire: Phase II Cooling Water Intake
Structures, January, 2000 (OMB Control Number 2040-0213). Industry Screener
Questionnaire: Phase I Cooling Water Intake Structures, January, 1999 (OMB
Control Number 2040-0203).
U.S. Geological Survey (USGS). 1995. Estimated Use of Water in the United States in
1995. At: http://pubs.er.usgs.gov/publication/cirl200.
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§ 316(b) Existing Facilities Final Rule - TDD Chapters: Subcategorization
Chapter 5: Subcategorization
5.0 Introduction
This section describes EPA's consideration of sub categories for the final rule. Section 5.1
discusses the methodology and factors considered when evaluating potential subcategories
for the rule. The remainder of the chapter discusses EPA's analysis of each factor.
5.1 Methodology and Factors Considered for Basis of
Subcategorization
In the development of other technology-based CWA regulations such as effluent
limitations guidelines, EPA considers a number of different factors. Among others, these
include the age of the equipment and facilities in the category, manufacturing processes
employed, types of treatment technology to reduce effluent discharges, and the cost of
effluent reductions (section 304(b)(2)(b) of the CWA, 33 U.S.C. 1314(b)(2)(B)). The
statute also authorizes EPA to take into account other factors that the Administrator
deems appropriate.
While the 316(b) language does not specifically require EPA to consider subcategories,
EPA concludes it is reasonable to do so because section 316(b) cross references sections
301 and 306.
EPA considered a number of factors as a basis of Subcategorization in determining best
technology available. The major factors EPA considered are:
• the age of facility or unit;
• electricity generation or manufacturing process;
• existing intake type;
• application of various impingement and entrainment reduction technologies;
• geographical location;
• facility size;
• non-water quality environmental impacts (including energy requirements)
• the potential for adverse environmental impact; and
• the cost of achieving impingement and entrainment reductions.
The following sections discuss EPA's consideration of these factors with the exception of
the cost of achieving impingement and entrainment reductions. See the EA for those
analyses.
5.2 Age of the Equipment and Facilities
As discussed in Chapter 4, many power plants and manufacturers have been in operation
for many years. Existing units may operate for decades before being replaced by new or
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Chapter 5: Subcategorization § 316(b) Existing Facilities Final Rule - TDD
more efficient units or retired altogether. EPA considered the age of equipment as a
Subcategorization basis. EPA concluded this is not an appropriate basis because power
plants and manufacturing facilities tend to be long-lived facilities and have regular
maintenance, equipment upgrades, plant expansions, and other activities. Equipment such
as intake technologies is generally included in the scheduled maintenance. Factors such
as the waterbody type, debris loading, and other site-specific factors will dictate how
frequently a facility needs to replace this equipment. EPA did not find that the age of
facilities or equipment changed the need of such facilities for cooling water (since gains
in efficiency have typically been used to maintain or increase power production or
productivity), or the impacts associated with cooling water use. Nor did EPA identify
significantly different CWIS technologies based on facility age. For example, nuclear
power facilities receive 30 or 40 year licensing, with license renewals of 10 or 20 years.
In site visits, EPA found this period of licensing did not correlate with individual facility
uprates, equipment replacement, or upgrades.
Using information collected through the industry questionnaire, site visits, and
conversations with industry representatives, EPA also evaluated age of the existing
facility as a possible basis for Subcategorization. EPA determined that the age of a facility
is not an appropriate measure for Subcategorization. Electric generators often add new
generating units and may then retire older, less-efficient units. As such, the date at which
the facility began operations may not be reflective of a facility's current operations.
However, EPA does recognize that many existing power plants and manufacturing
facilities operate older units; as noted in Chapter 4, over 31 percent of coal-fired
generating units are more than 50 years old. As a result, it may be undesirable to retrofit
some older facilities to closed-cycle cooling, as these facilities may be approaching the
end of their useful life.
5.3 Processes Employed
5.3.1 Electric Generators
The major difference between power plants in terms of "process" is the fuel source. As
illustrated in Chapter 4 of the TDD, power plants use a variety of fuels to generate
electricity.
Exhibit 5-1 shows the typical generating efficiencies for each fuel type.
Exhibit 5-1. Generating efficiency by fuel type
Fuel type
Coal
Natural gas
Natural gas (combined cycle)
Nuclear
Typical plant efficiency (%)
32-42
32-38
50-60
33
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
In general, the type of fuel used at a facility does not affect the design or operation of the
facility's CWIS. The type of fuel may affect the volume of water needed, additional
design considerations (e.g., emergency backup withdrawal capabilities), or other
elements of the facility's operation, but these elements generally do not impact the
selection or operation of intake technologies.
49
EPA also explored the thermal (fuel) efficiency of different fuel types as a basis. While
many reviews identify nuclear as far less efficient than coal, these comparisons do not
factor in the significant heat losses from the stack of coal-fired units. When this source of
heat is accounted for, there is no significant difference in thermal efficiency by fuel type
for generating units using steam only as it relates to waste heat passing through the
cooling system.
Based on discussions with industry during site visits, one of the main differences related
to fuel type is intake flow for nuclear facilities. In order to more fully explore the
assertion that nuclear facilities exhibit different trends in the utilization of cooling water,
EPA plotted the cumulative intake flow for nuclear and non-nuclear facilities. Exhibits
5-2 and 5-3 below illustrate the flow data by non-nuclear facilities and nuclear facilities,
respectively.
Exhibit 5-2. Distribution of intake flows for all non-nuclear electric generators
100%
90%
80%
70% -
^ 60% -
c
0)
o 50% -
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Chapter 5: Subcategorization
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 5-3. Distribution of intake flows for all nuclear electric generators
34567
DIP Threshold (BGD)
These exhibits show that nuclear electric generator facilities on average have a larger
flow than non-nuclear electric generators, which affects the size of the cooling system.
However, EPA did not identify significant differences in CWIS technologies between
nuclear and non-nuclear facilities and, therefore, this was not determined to be an
appropriate basis for Subcategorization.
EPA data also indicate that the distribution of nuclear facilities versus non-nuclear
facilities does not differ significantly by waterbody type (see Exhibit 5-4).
Exhibit 5-4. Distribution of nuclear and non-nuclear facilities by waterbody type
Waterbody type
Freshwater river or stream
Tidal river or estuary
Lake or reservoir
Great Lake
Ocean
Percent of nuclear facilities
39.7
15.5
22.4
13.8
8.6
Percent of non-nuclear
facilities
48.7
20.2
20.9
6.8
3.3
EPA data do indicate that a somewhat larger percentage of nuclear facilities use closed-
cycle cooling than non-nuclear facilities (see Exhibit 5-5). However, because the
percentage of nuclear facilities using closed-cycle cooling remains limited and the
majority of applications of closed-cycle cooling are newly built units (i.e., Palisades is the
only nuclear facility that has retrofitted to closed-cycle—see DCN 10-6888), this was not
determined to be an appropriate basis for Subcategorization.
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§ 316(b) Existing Facilities Final Rule - TDD Chapters: Subcategorization
Exhibit 5-5. Distribution of nuclear and non-nuclear facilities by cooling system type
Cooling water system type
Once-through
Closed-cycle
Combination or other
Percent of nuclear facilities
50.0
37.9
12.1
Percent of non-nuclear facilities
78.3
12.0
9.7
5.3.2 Manufacturers
In general, manufacturers use cooling water in much the same way as electric generators.
While the end product may vary (e.g., paper products versus electricity), the cooling
water is often used for similar industrial processes. As noted in Chapter 4, 164 (60
percent) of the 275 manufacturers surveyed indicated that they generated electricity
onsite as part of their operation and some even sold electricity and steam. An analysis of
water use survey data for cooling water intakes indicated that 47 percent of
manufacturing facility cooling water intakes used at least a portion of the cooling water
for electricity generation and that 9 percent of manufacturing facility intakes used greater
than 90 percent of cooling water for power generation.50 Where manufacturers differ is in
their use of contact cooling water and process water, which are typically also withdrawn
from the same intake structure as non-contact cooling water.51 Contact cooling water
comes into direct contact with the product, such as quench water for a steel mill and may
acquire certain contaminants. Process water is used within the process to create the end
product itself, such as water used in producing beverages. These two categories of water
withdrawals are distinct from non-contact withdrawals in that they are much more
difficult to reduce or eliminate without having a material effect on the end product. In
other words, flow reduction (such as the use of closed-cycle cooling) is less likely to be a
viable alternative for contact cooling or process flows, as the concentration of pollutants
through evaporation would adversely affect the facility's production. As a result, Options
2 and 3 (see Chapter 7 or the preamble for the proposed rule) excluded contact and
process flows from flow reduction requirements. As discussed in Chapter 8, EPA
adjusted its cost methodology for manufacturers to account for this difference; intake
flow rates (the basis for cooling tower costs) at manufacturing facilities were adjusted by
as much as 47 percent. As discussed in Chapter 3, intakes where less than 25 percent of
intake volume is used exclusively for contact or non-contact cooling purposes are not
subject to this rule.
Additionally, as shown in Chapter 4, manufacturers use essentially the same intake
technologies and cooling system types as electric generators. There is no indication that
cooling water withdrawal by manufacturers is any different than at generators and, as
50 The portion of manufacturing facility intakes (47 percent) that reported using cooling water for power
generation is smaller than the portion of facilities that generate electricity (60 percent). This may be due to
the fact that some manufacturers may generate electricity without using cooling water (e.g., cogeneration)
and that many manufacturers have multiple intakes but may only use one for power generation (see DCN
12-6630).
51 Electric generators use non-contact cooling water almost exclusively. As a result, no analysis of contact
or process water is required for power plants.
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Chapter 5: Subcategorization § 316(b) Existing Facilities Final Rule - TDD
noted above, a significant number of manufacturers use cooling water for similar purpose
as generators.52 EPA's observations during the site visits confirmed that most facilities
(including both manufacturers and generators) were found to be very similar in how they
use cooling water, how the intake technologies were selected and constructed, and the
types of challenges facilities faced in operating CWIS technologies. As a result, there is
no data suggesting that manufacturers should be addressed separately on the basis of
intake or cooling system technologies.
5.4 Existing Intake Type
As illustrated in Chapter 4, existing facilities use a variety of intake locations, designs,
and technologies for withdrawing cooling water. While a facility's site-specific
characteristics will have a significant impact on the facility's choice for its intake location
(e.g., shoreline, offshore, etc.) and the selection, design, and operation of the facility's
intake technology, generally any of the possible intake locations will be able to supply
sufficient cooling water to a facility. In addition, the various types of intake
configurations (e.g., canal, surface, sub-surface, infiltration, sequenced intakes such as an
intake emptying into a forebay) were not, by themselves, found to affect BTA. As such,
EPA determined that it could not establish any appropriate subcategories based on the
existing intake type. EPA did research the performance of existing far offshore intakes
and associated velocity caps (see DCN 12-6601). Based on available performance data
EPA concluded that the performance of neither the far offshore submerged intake
location nor the velocity cap technology alone could be relied upon to meet the BTA
impingement technology standard. However, the data indicated when used in
combination and provided they met certain criteria that the performance was equivalent
to the BTA impingement technology. Based on this analysis, EPA has deemed that
existing far offshore intakes with velocity caps that met certain criteria are compliant
with the BTA impingement requirement. See Chapter 6 for a more detailed discussion of
velocity caps and offshore intakes.
In general, the intake type does not affect a facility's ability to retrofit closed-cycle
cooling; the existing intake structure will have more than enough capacity to sustain the
reduced level of water withdrawals. Therefore, EPA did not consider intake type as a
factor in studying entrainment mortality requirements. Intake type may, however, affect
impingement mortality requirements. Where appropriate, EPA's compliance costs reflect
the existing intake location and the presence of existing intake technologies. As discussed
in Chapter 8, facilities with technologies deemed to be compliant with the impingement
mortality requirements of the rule are not assigned any compliance costs. Technologies
are, in part, assigned based on intake location, in order to facilitate the most cost-effective
compliance solution. Other facilities will be required to upgrade, as reflected in the
assigned technology costs.
52 With regards to IM&E, there is no indication that fish and shellfish differentiate for what purpose the
intake structure supplies cooling water.
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§ 316(b) Existing Facilities Final Rule - TDD Chapters: Subcategorization
5.5 Application of Impingement and Entrainment Reduction
Technologies
The final rule and record identifies several impingement and entrainment reduction
technologies in various categories, including flow reduction, closed-cycle cooling,
screens, diversions, barriers, fish returns, behavioral systems, velocity reduction, physical
configurations, and location. However, except for flow reduction, EPA has not identified
data that indicate that a specific impingement and entrainment reduction technology is
most effective for a particular segment of facilities. Rather, the data indicate that effective
technologies can be applied in a variety of settings and that facilities typically use these
technologies based on an appropriate configuration for the relevant facility. Thus, the
available data does not support Subcategorization based on particular impingement and
entrainment reduction technologies already in place or the technology availability.
EPA evaluated the possibility of Subcategorization based on flow reduction through
closed-cycle cooling. Since closed-cycle cooling is deemed a compliant technology,
facility intakes with existing closed-cycle cooling are considered compliant and require
no additional technology or further designation. For those not currently employing
closed-cycle cooling, EPA evaluated several facility attributes that could be considered as
potential criteria for subcategorizing facilities based on the relative availability of closed-
cycle cooling. These included factors such as land availability, energy reliability, air
emissions, and remaining plant useful life.
As discussed in section 5.9.6 below, land requirements and land availability vary from
site to site and EPA could not identify a specific metric such as a specific Gigawatt/acre
threshold that could reliably assess land availability. EPA looked at local population
densities as a proxy for land availability and the potential for additional requirements to
provide for plume abatement and to control emissions associated with drift for tower
exhaust air. While EPA concluded that roughly 25 percent of facilities may face such
requirements, EPA could find no specific attribute that could reliably be used to identify
and subcategorize them. EPA's evaluation of air emissions is discussed in TDD Chapter
10. A GIS analysis of increased power plant emissions due to closed-cycle cooling
indicated that a significant number of facilities are located in nonattainment areas for
PM2.5 and ozone. EPA concluded that the regional air pollutant non-attainment
designation is not a suitable criterion for Subcategorization as a proxy for availability of
closed-cycle cooling due to air permitting issues since the permitting considerations will
be subject to many site-specific factors.
As discussed in section 5.6 below, EPA conducted an analysis to evaluate energy
reliability issues due to construction downtime and increased power requirements for
closed-cycle auxiliary power and turbine efficiency reduction. Based on this analysis,
EPA concluded that while there may be some reliability concerns in certain locations, the
effects of closed-cycle cooling on national energy reliability would be minimal and that
energy reliability is not a suitable criterion for Subcategorization. EPA did find several
examples of local situations in the Washington, DC, Los Angeles, and Chicago areas
where limited grid connectivity might impact closed-cycle cooling availability as a result
of energy reliability concerns (e.g., loss of voltage support) but concluded these instances
are limited and are best addressed on a site-specific basis. See discussion and example in
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Chapter 5: Subcategorization § 316(b) Existing Facilities Final Rule - TDD
section 5.6 and site visit reports for Potomac (DCN 10-6512), Scattergood (DCN 10-
6545), Haynes (DCN 10-6547), Fisk (DCN 10-6543), and Crawford (DCN 10-6544).
EPA found that remaining useful life of a plant as it relates to closed-cycle cooling is
difficult to quantify since useful life may vary for different plant components and
infrastructure including cooling systems. An aging generating unit with an apparent short
useful life may be completely or partially repowered and may continue to use existing
infrastructure such as cooling towers. Remaining useful life is subject to many economic
considerations that make it difficult to quantify and thus unsuitable for consideration as a
criterion for Subcategorization.
As discussed in section 5.6 below, EPA also examined waterbody type as it related to the
availability of closed-cycle cooling since water characteristics such as total dissolved
solids (IDS) content can affect closed-cycle cooling system design and operating
conditions. For example, EPA recognizes that closed-cycle systems that use makeup
water with high TDS (such as from ocean and estuarine waterbodies) may need to operate
at different cycles of concentration which may affect the degree of flow reduction and
materials of construction, but concluded that while these considerations may affect costs
and performance to some degree, they do not affect the availability of the technology (see
section 6.1).
EPA also considered water consumption in the context of the availability of cooling
water or makeup water in regions where water resources may be limited. EPA found that
in such regions, the availability of evaporative closed-cycle cooling systems may be
limited but that these limitations also extend to other cooling system types such as once-
through cooling. Further, EPA found that, in many of these situations, existing facilities
use alternative cooling systems such as dry cooling rather than once-through or
evaporative closed-cycle cooling. EPA examined other factors in addition to those
discussed above and could not identify any that could potentially serve as a criterion for
Subcategorization based on availability of closed-cycle cooling.
5.6 Geographic Location (including waterbody category)
Existing facilities are located throughout the United States (see Exhibit 4-2 in Chapter 4),
operate in a variety of climatic, geologic, and hydrologic regimes, and are located in a
range of populated areas from urban to rural. While the local conditions may affect how
often a facility operates, its operational requirements, and the maintenance procedures
necessary to operate efficiently, facilities are well-accustomed to these site-specific
conditions and have incorporated these factors into their daily operations.
Geographic location can affect the physical and biological setting of a CWIS, but EPA
has not identified general trends that would allow the agency to use geographic location
as a basis for Subcategorization. EPA specifically identified reservoirs and manmade
impoundments with artificially managed fish populations as a possible candidate for
different requirements, but did not identify locational factors that affect the efficacy or
availability of the primary technologies that may comprise BTA. Rather, the data indicate
that effective technologies can be applied in a variety of settings and that facilities
typically use these technologies based on an appropriate configuration for the relevant
5-8
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
facility. EPA notes that it has included "regional cost factors" that adjusts model facility
costs based on the model facility's location to account for local conditions.53
As discussed in the preamble and EA, EPA has also analyzed the impacts of the final rule
on the reliability of regional power production. As an example of localized reliability
concerns, see Exhibit 5-6 below (taken from DCN 12-6840). This graphic illustrates the
concept of localized reliability zones, which may limit a facility's ability to import power
during downtime.
Exhibit 5-6. Example of local reliability concerns
Los Angeles Basin and San Diego local capacity areas
Big Creek/
entura
Mandalay
Ormond Beach
Los Angeles Basin
El Segundo
Redondo Beach
Alamitos
Huntinqton Beach ,- . Q
Enema'
O Power Plant
Local Reliability Areas
(generalized)
Caveat
The San Onofre Nuclear Generating Station is currently
subject to an extended outage.
Map does not reflect 2,200 MW of OTC capacity in LADWP's
balancing authority area.
San Diego
California ISO
EPA also considered waterbody category as a possible basis for Subcategorization. As
illustrated in Chapter 4 of the TDD, facilities are located on a variety of waterbody types.
In the Phase I rule, certain waterbody types were required to meet design and operational
criteria.54 In the 2004 Phase II rule, EPA established different performance requirements
based in part on a facility's location on different waterbody categories.55 That approach
was based on the general characteristics of the waterbody categories and of groups of
aquatic organisms. However, in the final rule, EPA is not differentiating between
53 For example, facilities located near the Great Lakes are allotted an increased cost for managing zebra
mussels.
54 For example, facilities are not permitted to withdraw more than 1 percent of the tidal excursion. See 40
CRR 125.84(b)(3)(iii).
55 Facilities located on estuaries, tidal rivers, Great Lakes, and oceans were subject to more stringent
requirements. See 69 FR 41590 (July 9, 2004).
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Chapter 5: Subcategorization § 316(b) Existing Facilities Final Rule - TDD
waterbody types; all facilities are required to meet the same impingement mortality and
entrainment mortality requirements. This approach is based on the study data being used
to establish BTA and the fact that these data do not reflect as clear a distinction between
waterbody categories as was used in 2004. Specifically, the characterization data show
the range of organism densities between waterbody types overlap. (See DCN 10-6701 for
more information.)
Further, the density of organisms may not be a key factor in assessing adverse
environmental impact. For example, some organisms are broadcast spawners and others
are nest-builders. 6 A single egg in a freshwater system may be more important to that
ecosystem than a single egg in a marine system.
In the absence of actual data that clearly establishes distinctions among waterbody
categories, EPA has determined that it could not establish any appropriate subcategories
based on waterbody type and that it is prudent to provide a consistent level of protection
to aquatic organisms affected by CWISs.
5.7 Facility Size
EPA evaluated multiple metrics in analyzing facility size for existing facilities: electricity
output, intake flow distribution, and the relationship of flow to compliance costs, small
business designation, and environmental impacts.
5.7.1 Intake Flow
EPA examined the universe of electric generators and manufacturers for trends in intake
flows. EPA recognizes that intake flow volume is an important element in determining
impingement and entrainment and it is, therefore, logical to examine intake flow as a
means for Subcategorization.
Industry uses multiple metrics for intake flow: design intake flow (DIP), actual intake
flow (AIF), and nameplate capacity. Design intake flow reflects the value assigned during
the cooling water intake structure design to the maximum volume of water the cooling
water intake system is capable of withdrawing from a source waterbody over a specific
period of time. Actual intake flow is the average flow actually used over a specific period
of time. Nameplate capacity is the amount of electric power delivered or required for
which a generator, turbine, transformer, transmission circuit, station of system is rated by
a manufacturer (this capacity is then correlated with required flow). EPA compiled DIP
information from the industry questionnaires for all electric generators in ascending order
and calculated the percent of flow captured by various flow thresholds (see Exhibits 5-7
through 5-11). To allow for the inclusion of closed-cycle facilities in this analysis, EPA
first needed to normalize the design intake flow (DIP) for each facility with closed-cycle
cooling to a comparable DIP that would be utilized by the facility if it employed a once-
through cooling system. For facilities that utilize a combination cooling system (i.e., part
56 Often, marine organisms are broadcast spawners while freshwater organisms are nest-builders or deposit
eggs in specific locations.
5-10
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
once-through and part closed-cycle), EPA reviewed the industry surveys to determine the
proportion of the DIP that would be converted.57
Exhibit 5-7 shows all electric generators plotted in ascending order by normalized DIP.
Exhibit 5-7. Normalized DIF at Phase II and III electric generating facilities
9,000,000,000
8,000,000,000
7,000,000,000
6,000,000,000
£ 5,000,000,000
o
LJT 4,000,000,000
Q
3,000,000,000
2,000,000,000
1,000,000,000
100
200 300 400 500 600 700
Facility Count in Ascending Order
800
900
1000
As shown by this plot, over 80 percent of these facilities have DIFs less than 1 BGD and
approximately 95 percent of facilities have DIFs less than 2BGD.
Exhibits 5-8 through 5-12 present the distribution of DIP and AIF (normalized and non-
normalized) flows across several criteria, as well as the distribution of nameplate
generating capacity across normalized DIP. The percent captured values shown are the
percent below each threshold.
• Exhibit 5-8 presents the percent of normalized DIP, normalized AIF, non-
normalized DIF, non-normalized AIF and total facilities captured relative to DIF
in billion gallons per day;
• Exhibits 5-9 through 5-12 present the percent of normalized and non-normalized
DIF and AIF across waterbody categories (FWR - freshwater rivers and streams;
TR&E - tidal rivers and estuaries; Oceans; GL - Great Lakes; and all facilities)
relative to DIF in billion gallons per day.
In some cases, facilities use helper cooling towers, cooling lakes, or other configurations that are, for the
purposes of this analysis, essentially once-through cooling. EPA did not adjust these flows.
5-11
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Chapter 5: Subcategorization
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 5-8. Distribution of intake flows for all electric generators
100%
90%
34567
DIP Flow Threshold (BGD)
- Normalized
DIP Captured
- Normalized
AIF Captured
-DIP Captured
-AIF Captured
-Total Facilities
Captured
The exhibit above shows that at thresholds below 3-4 BGD the distribution of flow is
such that a higher percentage of facilities are captured relative to overall flow
(normalized or non-normalized).
Exhibit 5-9. Distribution of normalized DIF for all electric generators
456789
DIF Flow Threshold (BGD)
• FWR normalized
DIF
-TR&E normalized
DIF
- Ocean
normalized DIF
• L&R normalized
DIF
-GL normalized
DIF
-All facilities
normalized DIF
5-12
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
Exhibit 5-10. Distribution of DIF (non-normalized) for all electric generators
100%
456789
DIF Flow Threshold (BGD)
-TR&EDIF
-Ocean DIF
-L&RDIF
-GLDIF
-All facilities DIF
These exhibits show that the distribution of flow and facilities are generally similar
across waterbody categories, although ocean facilities appear to use somewhat larger
flows. The non-normalized data also reflect greater variation than the normalized data
although the general distributions are similar.
Exhibit 5-11. Distribution of normalized AIF for all electric generators
100%
456789
DIF Flow Threshold (BGD)
- FWR normalized
AIF
-TR&E normalized
AIF
- Ocean
normalized AIF
- L&R normalized
AIF
-GL normalized
AIF
-All facilities
normalized AIF
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Chapter 5: Subcategorization
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 5-12. Distribution of AIF (non-normalized) for all electric generators
100%
456789
DIP Flow Threshold (BGD)
-L&R AIF
-GLAIF
-All facilities AIF
The AIF data do not show dramatic variation when compared with the DIP data for these
plots. One difference is that 90 percent or greater of AIF is captured at a lower facility
DIP threshold.
Exhibits 5-13 through 5-15 show the percentage of facilities (electric generator and
manufacturer separately, and then all facilities) and the total DIP and AIF that would be
addressed by various flow thresholds.
Exhibit 5-13. Electric generators and flow addressed by various flow thresholds
01
Q.
50
80 100 150 250 500 1000 2000
DIP Threshold (MGD)
• Generators
Above Threshold
• Generator DIP
Below Threshold
• Generator AIF
Below Threshold
5-14
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
Exhibit 5-14. Manufacturers and flow addressed by various flow thresholds
50
80 100 150 250 500 1000 2000
DIP Threshold (MGD)
• Manufacturers
Above Threshold
• Manufacturer DIP
Below Threshold
• Manufacturer AIF
Below Threshold
Exhibit 5-15. Facilities and flow addressed by various flow thresholds
20 50 80 100 150 250
DIP Threshold (MGD)
500 1000 2000
• Percent of Facilities
Above Threshold
• Percent of DIP
Below Threshold
• Percent of AIF
Below Threshold
5.7.2 Intake Flow and Impacts
EPA considered subcategorizing between large and small facilities, such as the 50 mgd
design flow threshold that separated Phase II facilities from Phase III facilities. A
common perception is that individual facilities with a smaller DIP will tend to have lower
5-15
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Chapters: Subcategorization
§ 316(b) Existing Facilities Final Rule - TDD
impingement and entrainment impacts since smaller volumes may affect fewer fish. This
may be true for some on an individual basis, particularly when smaller facilities withdraw
water from large waterbodies. But in other cases, the impacts may be significant since a
facility can withdraw large portions of water from small waterbodies or may be
contributing to a sizeable aggregate withdrawal between multiple facilities. A simple
measure of this is the percent of a facility's total DIP to the waterbody mean annual flow
(MAP) for facilities withdrawing from rivers and streams.58 Exhibit 5-16 shows the
distribution of surveyed facilities with data by percent DIF/MAF for all facilities
compared to those with a DIP less than 50 mgd. Exhibit 5-17 shows this same
distribution separately for generators and manufacturers for facilities with DIP less than
50 mgd. The data in these tables show that by themselves nearly 1/3 (32 percent) of all
facilities withdrawing from rivers and streams withdraw more than 5 percent59 of mean
annual flow. For facilities with a DIP less than 50 mgd, at least 19 known manufacturers
(16 percent) and 19 known generators (24 percent) withdraw more than 5 percent of the
mean annual flow cooling water from freshwater rivers and streams.60 Thus, even by
themselves, many manufacturers and generators with smaller DIP volumes have the
potential for significant impacts on freshwater rivers and streams.
Exhibit 5-16. Facility Design Intake Flows as a percentage of mean annual flow for
all facilities on rivers/streams and those with DIF < 50 MGD
Manufacturers and Generators
Combined
Intake flow as a
% of MAP
No data
1-5%
5-10%
10-20%
20-40%
40-60%
60-80%
80-100%
>100%
Total > 5%
Total with Data
DIP
All with DIP > 2 MGD
No. of
facilities
12
222
33
36
17
4
2
6
11
109
331
% of no. of
fac. with data
-
67.1%
10.0%
10.9%
5.1%
1.2%
0.6%
1.8%
3.3%
32.9%
100.0%
DIP > 2 MGD and < 50 MGD
No. of
facilities
13
160
15
11
4
1
1
2
4
38
198
% of no. of
fac. with data
-
80.8%
7.6%
5.6%
2.0%
0.5%
0.5%
1.0%
2.0%
19.2%
100.0%
Note: All values are unweighted
58 As shown in Chapter 4, an estimated 52 percent of generators and 77 percent of manufacturers withdraw
cooling water from freshwater rivers and streams as opposed to other waterbody types. Therefore, this
metric is relevant to the majority of facilities.
59 As discussed in Chapter 4, a 5 percent threshold was included in the 2004 Phase II rule to identify
facilities subject to impingement mortality and entrainment requirements. While not included in this rule,
this threshold may be indicative of the potential for significant impact.
60 These numbers include only those facilities that completed the technical survey and since only a sample
of manufacturers received a survey, the actual number of facilities may be much greater. For example, the
19 known manufacturers are estimated to represent 55 facilities.
5-16
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
Exhibit 5-17. Facility Design Intake Flows as a percentage of mean annual flow for
all facilities and those with DIF < 50 MGD
Q
o
5
o
w
V
•o
03
Q
O
5
CM
A
LL.
Q
Intake flow as a
% of MAP
No data
1-5%
5-10%
10-20%
20-40%
40-60%
60-80%
80-100%
>100%
Total > 5%
Total with Data
DIF
Generators
No. of
facilities
9
59
8
5
1
1
0
1
3
19
78
% of no. of
fac. with data
-
75.6%
10.3%
6.4%
1.3%
1.3%
0.0%
1.3%
3.8%
24.4%
100.0%
Manufacturers
No. of
facilities
4
101
7
6
3
0
1
1
1
19
120
% of no. of
fac. with data
-
84.2%
5.8%
5.0%
2.5%
0.0%
0.8%
0.8%
0.8%
15.8%
100.0%
Note: All values are unweighted
Another important consideration with regard to the potential impacts is that smaller flow
facilities are often co-located on the same waterbody as other facilities (both large and
small) with each contributing to the aggregate volume of cooling water withdrawn and
the resulting cumulative impingement and entrainment impacts. In fact, EPA found that
for all surveyed facilities that withdrew cooling water from a freshwater river or stream,
72 percent of all facilities (representing 78 percent of the total design flow) withdrew
cooling water from a waterbody that had at least one, and often many, other facilities that
were also withdrawing water from the same waterbody. For facilities with a DIF less than
50 mgd, 63 percent of facilities (representing 70 percent of total design flow) withdrew
water from a freshwater river or stream that had at least one other facility withdrawing
water from the same river/stream. Exhibit 5-18 presents a summary of the number of
surveyed facilities that are located on the same river or stream and the number that are on
rivers and streams where the cumulative DIF was greater than 5 and 50 percent of mean
annual flow (MAP). These data show that for manufacturers and generators with a DIF
less than 50 mgd, 57 percent are located on rivers and streams where they contribute to a
cumulative withdrawal that is greater than 5 percent of the MAP of the waterbody and
9 percent are located on rivers and streams where they contribute to a cumulative
withdrawal that is greater than 50 percent. This demonstrates that while the individual
withdrawal may be small for some facilities, many (nearly two thirds) of the smaller flow
facilities contribute to cumulative withdrawals on freshwater rivers and streams and that
nearly one tenth contribute to potentially significant withdrawals with withdrawals of
greater than 50 percent of mean annual flow.
5-17
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Chapter 5: Subcategorization
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 5-18. Number of surveyed facilities located on the same river or stream as
other facilities and number contributing to cumulative withdrawals greater than
five percent and 50 percent of mean annual flow
•o
CM
A
LL.
Q
•o
U)
§
V
•o
03
•o
CM
£
a
Number of Facilities Located on the Same
River/Stream as Other Facilities (Co-located)
Number of Facilities Co-located on River/
Stream where Cum Withdrawals of all Facilities
on the Waterbody Exceed > 5% of MAF
Total Number of Facilities on River/Stream
where Cum Withdrawals Exceed > 5% of MAFa
Total Number of Facilities on a River/Stream
where Cum Withdrawals of all Facilities on the
Waterbody Exceed > 50% of MAFa
Total Facilities on River/Stream
Number of Facilities Located on the Same
River/Stream as Other Facilities (Co-located)
Number of Facilities Co-located on
River/Stream where Cum Withdrawals of all
Facilities on the Waterbody Exceed > 5% of
MAF
Total Number of Facilities on River/Stream
where Cum Withdrawals Exceed > 5% of MAFa
Total Number of Facilities on a River/Stream
where Cum Withdrawals of all Facilities on the
Waterbody Exceed > 50% of MAFa
Total Facilities on River/Stream
Generators
Count
257
229
263
51
343
55
38
52
10
87
%of
Total
75%
67%
77%
15%
100%
63%
44%
60%
11%
100%
Manufacturers
Count
117
95
115
18
178
77
57
68
9
124
%of
Total
66%
53%
65%
10%
100%
62%
46%
55%
7%
100%
Both
Count
374
324
378
69
521
132
95
120
19
211
%of
Total
72%
62%
73%
13%
100%
63%
45%
57%
9%
100%
a Includes data for waterbodies with only one facility
Note: All values are unweighted
As can be seen in Exhibit 4-2 in the previous chapter, the majority of facilities that use
cooling water are located in the eastern portion of the United States. Exhibit 5-19
presents a map of the eastern half of the United States showing facility location for
generators and known manufacturers.61 The map shows that while facilities are located
throughout the region, many are concentrated on the same waterbodies often in close
proximity to one another. This proximity is better illustrated in Exhibit 5-20 which
presents a graphical representation that shows the relative proximity of facilities by
including for each facility five mile radius buffer zones for distances of 5, 10, 15, and
20 miles. Exhibit 5-21 presents the proportion of facilities that have one or more other
facilities within the each buffer distance of 5, 10, 15, and 20 miles. As can be seen, a
majority (69 percent) of the known facilities are located within a distance of 20 miles or
less from other facilities and nearly half are within 10 miles or less. The actual
proportions are likely larger since many manufacturing facilities locations (approximately
300) are not known and therefore are not included in this analysis. Certain regions show
61 Only those facilities that completed a technical survey are shown in Exhibits 5-19 and 5-20. While most
generators completed either a short or detailed survey and thus their presence is shown, EPA estimates that
there around 300 additional manufacturing facilities that are not represented in the graphics.
5-18
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
high concentrations of multiple facilities on the same waterway as shown by the
considerable amount of overlap of buffer zones.
Exhibit 5-19. Location of facilities in eastern half of United States
Legend
Manufacturer
• Generator
316(b) Facilities
5-19
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Chapter 5: Subcategorization
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 5-20. Representation of facility location proximity in the Eastern US
Legend
316(b) Facilities
Design Intake Flow
O > 50 MGD
• < 50 MGD
Facility Buffers
Buffer Distance (mi)
^•1 5
10
15
20
316(b) Facility Proximity
5-20
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
Exhibit 5-21. Proportion of facilities with known location one or more other
facilities within each buffer distance
within 5
miles
30%
within 10
miles
47%
within 15
miles
62%
within 20
miles
69%
Not within 20 miles of
another facility
31%
5.7.3 Intake Flow and Business Size
EPA considered flow thresholds of 50 mgd or less as possible thresholds for a
subcategory that would be representative of most small businesses but found that facility
DIP does not correlate well with the small business designation. Exhibit 5-22 shows the
distribution of all facilities and small businesses and the corresponding total DIP by
subgroups in the 2 to 50 mgd range. These data show that while roughly half of small
business facilities had a DIP less than 20 mgd, 35 facilities (28 percent) had a DIP greater
than 50 mgd. Also, there were many non-small businesses distributed throughout the less
than 50 mgd subgroups. Thus, a subcategory based on low DIP flow would not capture a
significant portion of small businesses and would include many large businesses.
Exhibit 5-22. Distribution of small businesses by DIF
All Facilities
DIF Total (MGD)
Small Business Fac.
DIF Total (MGD)
DIF 2-10
172
921
34
169
DIF 10-20
119
1,778
29
391
DIF 20-30
111
2,811
8
204
DIF 30-40
73
2,525
14
472
DIF 40-50
56
2,519
6
274
DIF > 50
651
336,577
35
12,624
EPA has found that many facilities have a DIF less than 50 mgd because they already
employ closed-cycle cooling. Fifty one percent of all facilities with a DIF less than 50
mgd employ closed-cycle cooling and 33 percent of manufacturers with a DIF less than
50 mgd employ closed-cycle cooling. Since closed-cycle cooling is generally compliant
with BTA requirements, the permitting requirements are streamlined for many of the
facilities in the less than 50 mgd subcategory. Exhibit 5-23 presents a summary of the
number of small businesses (and those with a DIF less than 50 mgd) and all businesses
with a DIF less than 50 mgd that were deemed to be compliant with the EVI BTA
standard. This data show that the proportion of facilities that are deemed EVI compliant is
high for all three groups. For the subset of small businesses with a DIP less than 50 mgd
the proportion deemed EVI compliant is higher. For facilities less than 50 mgd, small
businesses are comparable but somewhat less compliant than all businesses. Thus, the
overall financial burden is reduced for both small businesses and all businesses with a
DIP less than 50 mgd, indicating that overall financial burden may not be a factor that
supports Subcategorization based on flow volume or business size.
5-21
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Chapter 5: Subcategorization
§316(b) Existing Facilities Final Rule-TDD
Exhibit 5-23. Summary of number of small businesses and all businesses with a DIF
less than 50 MGD that are deemed already compliant with the IM BTA standard
Number of
Intakes
(weighted)
Number that
already meet
the IM standard
(weighted)
Number with no
technologies in
place
(weighted)
Small Businesses
EG
43
14
5
MN
102
38
1
Total
145
53
6
Small Businesses <50 MGD
EG
13
6
5
MN
87
34
1
Total
100
40
6
All Businesses <50 MGD
EG
129
101
8
MN
466
220
14
Total
595
321
22
EPA also examined the potential impact of the group of facilities that are small
businesses with an AIF less than 50 mgd 62 with respect to whether the majority of those
located on rivers and streams have the potential to contribute to cumulative impingement
and entrainment impacts if they are included in the scope of the EVI requirements. Exhibit
5-24 presents a graphical illustration showing the location and proximity of 15 of the 22
small businesses with known locations63 that have an AIF less than 50 mgd and are
located on rivers and streams. Only those that do not already employ closed-cycle cooling
or do not withdraw greater than 5 percent of mean annual flow are identified separately
from all of the other facilities.64 As can be seen, nearly all of the facilities in this group
are in fairly close proximity to other facilities and are likely to contribute to cumulative
impingement and entrainment impacts. Therefore, EPA did not consider low flow and
small business designation as a factor that supports Subcategorization.
62 In this subset of small businesses, the flow criteria AIF less than 50 mgd is used instead of DIF greater
than 50 mgd which represents a larger group of small businesses than those facilities greater than 50 mgd
shown in Exhibit 5-24.
63 Only 15 of the 22 facilities are located in the eastern half of the US. The additional 7 are located mostly
in Washington State with 5 of the 7 being located in close proximity to other facilities.
64 The IM requirements will have no impact on those that employ closed-cycle cooling and those with an
AIF greater than 5 percent of MAP have a significant impact regardless of proximity to other facilities.
5-22
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
Exhibit 5-24. Representation of facility location proximity in the eastern US showing
small businesses on rivers and streams with AIF< 50 MGD
** ObVSr* '<&
Q •' P l °%0
Q 0 I
f \ - •** IfciWW?
**" f «° *v °,
V &'
o °o « 1
V o oj
o> , ^
Small Business (AIF <50 MGD)
All Other Facilities
^ O P / All Other Fac
\ ^ ' Facility Buffers
5^ i^! __J^ Buffer Distance (mi
316(b) Facility Proximity
5-23
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Chapter 5: Subcategorization
§ 316(b) Existing Facilities Final Rule - TDD
5.7.4 Intake Flow and Cost
Exhibit 5-25 shows the estimated total annual pretax compliance costs for all facilities
with a DIP above the DIF threshold.
Exhibit 5-25. Total annualized pretax compliance costs above DIF threshold
500
1,000 1,500 2,000 2,500
DIF Threshold (MGD)
3,000
3,500
EPA examined total annual compliance costs for flow thresholds of 50 mgd or less to see
if there were any noticeable differences between total costs below and above the
threshold. Exhibit 5-26 shows that as would be expected total costs increase as of DIF
threshold values decrease and the curve shows minor differences at about 12 mgd and 58
mgd but statistically significance along the curve does not support selecting any specific
DIF value for Subcategorization.
Exhibit 5-26. Total annualized pretax compliance costs above DIF thresholds of 2 to
100 MGD
$200
10
20
30 40 50 60
DIF Threshold (MGD)
70
80
90
100
5-24
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
EPA considered the possibility of establishing a flow threshold above which closed-cycle
cooling would be required. EPA examined total entrainment compliance cost of requiring
closed-cycle cooling at all facilities not currently employing closed-cycle for different flow
threshold values. Preliminary estimates of facility level closed-cycle cooling capital and
O&M cost were derived using the approach described in section 8.3. Variable O&M costs
assume a technology utilization rate of 85 percent and auxiliary energy costs are based on a
wholesale rate of $65/MWh. Capital costs are amortized at 3 percent over 30 years. The
cost evaluated does not include downtime or heat rate efficiency loss. Exhibit 5-27 presents
a plot of total annual cost above the DIP threshold. This plot generally shows a steady
change in total costs at most thresholds as evidenced by the steady slope. Breaks in the
curve at various thresholds greater than 1,000 mgd represent flow ranges that include fewer
facilities. Thus, except for thresholds at the higher end of the range there does not appear to
be any discernable difference based on costs and regardless of the threshold, the reasons for
rejecting closed-cycle cooling as BTA remained the same. EPA also, examined flow
threshold as it relates to closed-cycle costs for certain facility subsets, such as different fuel
types and manufacturers as a group. EPA generally found similar cumulative cost curves
for each subset with some exceptions. For nuclear plants, there were zero facilities with
closed-cycle costs with a DIP less than 500 mgd and for manufacturers there were few
facilities with a DIP greater than 700 mgd. These relatively high thresholds reflect design
flow distributions for these subsets. EPA also considered requiring closed-cycle cooling for
nuclear facilities that could have included a flow threshold. Annual costs were estimated to
be approximately $1 billion dollars annually but would provide a high reduction for
impingement and entrainment given that these facilities tend to have large flows and
operate as baseload generators. However, long downtime and reliability are also concerns.
Based on these data, EPA concluded that flow threshold as it relates closed-cycle cost does
not support selecting any specific DIP value for Subcategorization.
Exhibit 5-27. Total annualized pretax closed-cycle cooling compliance capital and
O&M above DIF threshold
$6,000
$5,000
$2
as
"5
Q
$4,000
$3,000
$2,000
$1,000
500
1,000 1,500 2,000 2,500
DIF Threshold (MGD)
3,000
3,500
5-25
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Chapter 5: Subcategorization
§316(b) Existing Facilities Final Rule-TDD
5.7.5 Generating Capacity
Exhibit 5-28 presents the distribution of nameplate generating capacity across normalized
DIP."
65
Exhibit 5-28. Distribution of nameplate generating capacity
2000
1500
1000
*
» 7
mz
Ascending Normalized DIP
Exhibit 5-28 shows a general and somewhat variable correlation between DIP and
electrical power output, and also indicates that some facilities, most likely more efficient
operations, are able to produce a range of power at a lower DIP. However, such
production is not necessarily correlated with CWIS technologies and the rule includes
provisions that promote reductions in cooling water intake flow.
EPA also considered generating capacity as an aspect of facility size. Exhibit 5-28 above
presents generating capacity plotted against normalized DIP and Exhibit 5-29 below
presents generating capacity plotted against non-normalized DIP.66
65 Recall that normalized DIP as described earlier converts DIP for closed-cycle facilities to the equivalent
once-through DIP.
66 Non-normalized DIP is the actual reported design intake flow.
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
Exhibit 5-29. Distribution of nameplate generating capacity
4000
3000
2500
2000
1500
1000
500
V
Ascending DIP
Exhibit 5-29 shows a similar pattern to Exhibit 5-28, with greater scatter of facilities,
which suggests that closed-cycle cooling provides a range of flow reduction that is
dependent on numerous factors.
As illustrated by the exhibits above, there are no clear trends for electric generating
facilities based on intake flow relative to waterbody type, cumulative impacts, costs or
generating capacity. As such, EPA determined that it could not establish any appropriate
subcategories based on any of those categories.
5.8 Non-Water Quality Environmental Impacts
New or additional intake technologies will not lead to unusual non-water quality
impacts.67 Many of the technologies discussed in the rule are already in use at many
facilities and do not fundamentally change the operation of intake technologies as a
whole. EPA recognizes that requiring facilities to retrofit to closed-cycle cooling may
incur additional non-water quality impacts that are not insignificant. These impacts are
part of the reason that EPA did not identify closed-cycle cooling as the basis for BTA for
this national rule. EPA did not identify any other significant non-water quality
environmental impacts resulting from the engineering aspects of control technologies that
provide a basis for establishing appropriate subcategories.
3 See Chapter 10 for a complete discussion of the non-water quality impacts.
5-27
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Chapter 5: Subcategorization
§316(b) Existing Facilities Final Rule-TDD
5.9 Other Factors
EPA conducted a series of additional analyses of existing facilities in order to attempt to
determine if any additional subcategories were appropriate.
5.9.1 Capacity Utilization
-^^ /:Q
EPA reviewed data on the capacity utilization rate (CUR) for Phase II facilities using
information from EPA's E-GRID database.69 In order to best match the technology data
from EPA's industry survey, EPA used the CUR data from the year 2000. Specifically,
EPA compared the CUR data against data for fuel type (by individual generating unit and
by facility), prime mover, total generating capacity (by individual generating unit and by
facility), facility age, and waterbody type. As shown in Exhibits 5-30 to 5-36 below, there
are no clear trends in any of these analyses that indicate that BTA should be different
based on low usage. As such, EPA determined that it could not establish any appropriate
subcategories based on capacity utilization.
Exhibit 5-30. Cumulative distribution of Phase II Facility year 2000 generating unit
capacity factors by primary fuel type
5% 10% 15% 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100%
68 The analysis was not repeated to incorporate Phase III facilities, as the distribution of facilities among
capacity utilization rate, fuel type, and waterbody type is relatively consistent between the two groups.
69 CUR was a factor in the 2004 rule and was considered in developing the final rule.
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
Exhibit 5-31. Distribution of Phase II Facility year 2000 generating unit capacity
factors by generating unit prime mover
10% 15% 20% 25% 30% 35% 40% 45% 50% 60% 70% 80% 90% 100%
Capacity Factor
Steam (1 268)
Gas Turbine (79)
Combined cycle steam turbine with supplementary firing (19)
I nternal Combustion (1 2)
Combined cycle combustion turbine (38)
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Chapter 5: Subcategorization
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 5-32. Phase II Facility year 2000 generating unit capacity factors versus
nameplate generating unit capacity
Generating Capacity (MW)
Exhibit 5-33. Phase II Facility generating unit year 2000 capacity factor versus year
generating unit came online
Year Generating Unit Online
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
Exhibit 5-34. Distribution of Phase II Facility year 2000 total plant capacity factors
by primary fuel type
COAL (306)
GAS (129)
NUCLEAR (58)
OIL (39)
SOLID WASTE (8)
ALL (541)
5% 10% 15% 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75%
Capacity Factor
85% 90% 95% 100%
Exhibit 5-35. Distribution of Phase II Facility year 2000 total plant capacity factors
by intake waterbody type
Ocean (21)
Estuary (108)
Great Lake (43)
Freshwater River (253)
Lake/Reservoir (114)
01
a.
5% 10% 15% 20% 25% 30% 35% 40% 45% 50% 55% 60% 65% 70% 75%
85% 90% 95% 100%
Capacity Factor
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Chapter 5: Subcategorization
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 5-36. Phase II Facility year 2000 total plant capacity factor versus total
generating capacity
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ctn% -
yn% -
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5.9.2 CUR Versus DIP
EPA also examined the relationship between the design intake flow (adjusted for closed-
cycle cooling, as described above) and the CUR for Phase II facilities. As shown in
Exhibit 5-37 below, there is no clear relationship between a facility's size (i.e., DIP) and
it's frequency of operation. As such, EPA determined that it could not establish any
appropriate subcategories based on the relationship of CUR and DIP.
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
Exhibit 5-37. Distribution of capacity utilization
100%
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5 40%
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5.9.3 Low Capacity Utilization Compared With Spawning Seasonality
In the 2004 Phase II rule, facilities with a CUR below 15 percent were not required to
meet entrainment requirements. As discussed in the preamble for the 2002 proposed rule
(see 67 FR 17141, March 19, 2003), EPA found (at that time) that the reduced level of
operations at these facilities would provide ample protection for aquatic organisms due to
a substantial reduction in intake flows on an annual basis.
This final rule does not employ this same approach. This rule establishes IM standards,
and EPA did not find that costs for low CUR facilities posed national level impacts. EPA
has adopted this approach because low CUR facilities, while they do offer reduced flows
on an annualized basis, typically operate at or near their full design capacity when they
are in operation. If these periods of activity coincide with periods of high biological value
(such as a spawning period), then these low CUR facilities may be having as much
impact on aquatic organisms as a facility that operates more frequently. Furthermore,
these low CUR units serve an important function for local energy reliability. Therefore
the final rule allows that facilities with intakes that serve generating units with a CUR
less than 8 percent over a contiguous 24 month period may request that the Director
establish less stringent BTA standards for impingement mortality based on BTA. EPA
adopted the 8 percent CUR cutoff to be consistent with the definitions of low CUR
facilities in other programs, such as EPA's air regulatory efforts.
EPA reviewed the group of facilities with a CUR below 10 percent (38 facilities70) listed
in Exhibit 5-38 below and compared the operational periods of these facilities71 to key
biological periods for fish species in the source waterbodies for these facilities. As
70 These 38 facilities represent approximately 5.4 percent of the total DIP of Phase II facilities.
71 Derived from monthly flow data from the industry questionnaire.
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Chapter 5: Subcategorization
§ 316(b) Existing Facilities Final Rule - TDD
expected, low CUR facilities are most active in the summer and winter, when electricity
demand is generally highest.
Exhibit 5-38. Facilities with CUR less than 10 percent
Facility name
Conners Creek
Marysville
Oswego
Edgewater
Honolulu
Zuni
Atkinson
Plant Crisp
Collins
Peru
Kaw
Monroe
Austin DT
Fox Lake
M L Hibbard
Hawthorn
Burlington
Piqua
Delaware
Schuylkill
Lake Pauline
North Texas
Sam Rayburn
Blackhawk
Menasha
Rock River
Riverside
Kearny
Linden
Sayreville
Sewaren
Indian Point
Hookers Point
Mason Steam
Henry D King
Indian River Plant
McManus
Riverside
State
Ml
Ml
NY
OH
HI
CO
GA
GA
IL
IN
KS
LA
MN
MN
MN
MO
NJ
OH
PA
PA
TX
TX
TX
Wl
Wl
Wl
MD
NJ
NJ
NJ
NJ
NY
FL
ME
FL
FL
GA
GA
Waterbody region1
Great Lakes
Great Lakes
Great Lakes
Great Lakes
Hawaii
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Inland
Mid-Atlantic
Mid-Atlantic
Mid-Atlantic
Mid-Atlantic
Mid-Atlantic
Mid-Atlantic
Gulf of Mexico
North Atlantic
South Atlantic
South Atlantic
South Atlantic
South Atlantic
Waterbody type2
Great Lakes
Great Lakes
Great Lakes
Great Lakes
Ocean
Freshwater river or stream
Freshwater river or stream
Lake or reservoir
Freshwater river or stream
Freshwater river or stream
Freshwater river or stream
Freshwater river or stream
Lake or reservoir
Lake or reservoir
Freshwater river or stream
Freshwater river or stream
Freshwater river or stream
Freshwater river or stream
Freshwater river or stream
Freshwater river or stream
Lake or reservoir
Lake or reservoir
Freshwater river or stream
Freshwater river or stream
Lake or reservoir
Freshwater river or stream
Estuary or tidal River
Estuary or tidal River
Estuary or tidal River
Estuary or tidal River
Estuary or tidal River
Estuary or tidal River
Estuary or tidal River
Estuary or tidal River
Estuary or tidal River
Estuary or tidal River
Estuary or tidal River
Estuary or tidal River
1 In this context, "region" is defined as the fisheries region used in the national benefits analysis in the Benefits Analysis
for the Final Section 316(b) Existing Facilities Rule (BA).
2 Waterbody type is a regulatory classification under the 2004 Phase II rule.
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§ 316(b) Existing Facilities Final Rule - TDD Chapters: Subcategorization
EPA then examined the spawning periods of common fish species in each region of the
country. (See DCN 10-6702.) Since the facilities with a low CUR do not show any
regional or geographic trends (i.e., no one region has disproportionately more low CUR
facilities), it is reasonable to conclude that a broader review offish species by region will
adequately address the correlation between spawning season and CUR. Two conclusions
are apparent:
• For many waterbodies, there are few periods in the year when there is an absence
of spawning activity, indicating that facility operations at any time of the year
could have an impact on aquatic organisms.
• The operational periods of many low CUR facilities coincide with spawning
periods of nearby fish species.
As such, EPA determined that low CUR facilities should not be categorically exempted
from entrainment requirements but recognizing that the biological densities and timing
will vary from facility to facility EPA provided the Director the flexibility to establish
BTA impingement mortality standards for intakes serving generating units with a CUR
less than 8 percent.
5.9.4 Fish Swim Speed
The swimming ability offish is one key component in reducing impingement (and therefore
impingement mortality). EPA reviewed data from an Electric Power Research Institute
(EPRI) study on fish swim speeds (see DCN 2-028 A) to determine if there was any
difference in the swimming abilities offish in different waterbodies. As shown in Exhibit 5-
39, assemblages offish in the various waterbodies did not demonstrate any clear superiority
in swimming ability. As such, EPA determined that it could not establish any appropriate
waterbody-based subcategories based on the fish swim speed in those waterbodies.
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Chapter 5: Subcategorization
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 5-39. Swim speed versus fish length
10 20 30 40 50 60 70
Fish Length (cm)
5.9.5 Water Use Efficiency
EPA also analyzed power generating facilities' cooling water withdrawals and electricity
generated as a measure of how efficient a given facility is in its use of cooling water.
Initially, EPA examined the design intake flow for facilities above 50 mgd and compared
it to their steam generating capacity as a way to identify the least efficient facilities.
Exhibit 5-40 shows the results of this analysis, with cooling impoundment sites identified
separately.
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§ 316(b) Existing Facilities Final Rule - TDD
Chapters: Subcategorization
Exhibit 5-40. Design Intake Flow (gpm) / MW steam capacity for once-through
power plants over 50 MGD
Design Flow GPMJMW Steam Capacity Versus DIP for Once-through Power Plants >50
MGD
4000 -
3500 -
€
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1000 -
500 -
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• Old DUT1275
Pond Facilities
0 500 1 pOO 1,500 2,000 2,500 3,000 3500
DIP (GPU)
EPA expanded upon this analysis by using data from the industry surveys (actual intake
flow) and compared it to the electricity generation from the corresponding period.
Facilities were then sorted based on the calculated ratio of water use per megawatt
generated. Exhibit 5-40 shows the median ratio for facilities with various cooling system
types (once-through, closed-cycle, combination, and combined cycle72). EPA examined a
range of analyses for water use efficiency, including variants that excluded facilities that
utilize closed-cycle cooling, as these facilities clearly withdraw less water per megawatt
than once-through facilities. Exhibit 5-41 shows the median efficiency for each type of
facility, with a variety of horizontal lines that represent various thresholds; for example,
the top 10 percent most efficient power plants (including closed-cycle) have
approximately the same efficiency as closed-cycle systems, while the same ratio drops
significantly when closed-cycle systems are excluded. See Chapter 7 for more discussion
of how EPA considered this information.
The increased generating efficiencies of combined cycle plants warranted their separation into a different
grouping.
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Chapter 5: Subcategorization
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 5-41. Median water efficiency (water use per MW generated) of power
plants (including CCRS)
500
450
400
350
Median Water Efficiency (Water Use per M W Generated) of Power Plants
Top 10% of all plants
(including CTs)
Top quartile of all plants
Top and bottom quartile of
Once-through Natural Gas Combined Combination Cooling Closed-cycle Recirculating
Cycle System /Cooling Towers
5.9.6 Land Availability
While EPA has concluded that the vast majority of facilities have adequate available land
for placement of cooling towers,73 some facilities may have legitimate feasibility
constraints. Based on site visits, EPA has found several facilities have been able to
engineer solutions when faced with limited available land. EPA attempted to determine a
threshold of land (one option explored a threshold of approximately 160 acres per
gigawatt) below which a facility could not feasibly install cooling towers.74 Based on
such an approach, EPA projected an upper bound of 25 percent of facilities that may have
insufficient space to retrofit to cooling towers. While EPA estimated that some facilities
would not have enough space, EPA found some facilities with a small parcel of land were
still able to install closed-cycle cooling by engineering creative solutions.75 On the other
hand, EPA found that some facilities with large acres still could not feasibly install
cooling towers due to, for example, protected wetlands. While EPA was able to account
for space constraints in its estimated compliance costs (see Chapter 8), there was not
enough data to make a site-specific assessment of available land. As a result of the large
uncertainty surrounding EPA's data and analysis of available space, EPA rejected land
availability as a potential subcategory.
73 In the case of fossil fuel plants, scrubber controls may also be newly required to comply with air rules
and standards.
74 See DCNs 10-6671 and 10-6672.
75 Facilities could also build cooling towers in elevated locations, such as building roofs but this is more
expensive and is not feasible for many facilities.
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§ 316(b) Existing Facilities Final Rule - TDD Chapters: Subcategorization
5.9.7 Fish Species
EPA considered Subcategorization based on different groups offish species or species
attributes. In an analysis of possible grouping strategies for fish species, EPA identified
1,279 of the 3,694 species in and around North America that could reasonably be
expected to occur in the U.S. in the vicinity of CWISs and be exposed to IM&E related to
those CWISs.76 (See DCNs 10-6704 and 10-6704A.) After considering different
taxonomic levels of classification for grouping similar species, EPA concluded that
grouping by family classification (which resulted in 72 family groups) struck a good
balance between the need to be general enough to minimize number of groups while
specific enough to capture meaningful morphological and habitat-specific differences
among the various species. EPA concluded that this grouping scheme would need further
refinement as some families with similar characteristics could be grouped together while
other more diverse families may require division. EPA considered conducting further
investigation into habitat preferences, geographic ranges, and swim speed analyses in
order to identify group characteristics but concluded that the analysis would be complex
and the approach would be difficult to implement since it required consideration of
multiple characteristics and possible development of separate standards for a large
number of groups.
After careful consideration, EPA abandoned the fish species grouping approach and
instead adapted a more simplified approach that grouped species by relative degree of
fragility related to susceptibility to injury and death resulting from impingement. EPA
initially identified species from the impingement mortality database list and divided them
into three categories, fragile, somewhat fragile and hardy (see DCN 12-6700). This
approach was consistent with stakeholder suggestions that EPA should establish different
limitations for fish species with different degrees of potential for impingement survival.
EPA compared the results of this analysis with an estimate of relative impingement
survival for fish families provided by industry representatives (see DCN 12-6808) and
found the two lists to be in general agreement with regard to fragile species (see DCN 12-
6700). Since EPA was unable to identify any technology that reduces impingement
mortality for fragile species that was widely available nationally,77 EPA concluded that a
separate impingement mortality standard for fragile species was unworkable.
EPA did incorporate grouping by species hardiness in the BTA requirements by grouping
offish into two hardiness classifications in the development and application of the percent
impingement mortality standard. EPA was concerned that mortality data from fragile
species might, in large part, reflect conditions other than technology performance and
concluded that the EVI performance of modified traveling screens is relatively predictable
with respect to non-fragile species. As a result, EPA developed the 12 month percent
impingement mortality standard based on the performance with respect to fragile species
only and specified that the standard only applies to fragile species (see Chapter 11).
76 The difference includes species that do not occur in the U.S. (e.g., only in Canada or Mexico) and those
that are unlikely to occur in near-shore waters.
77 EPA did identify technologies that might be effective for fragile species (such as low velocity for
salmonids or behavioral avoidance tailored for certain fragile species) but concluded that neither of these or
other potential technologies are widely available.
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Chapter 5: Subcategorization § 316(b) Existing Facilities Final Rule - TDD
EPA determined that additional regulatory requirements to document further distinction
between species would be an unnecessary burden, as it would result in unnecessary
complications and expense for facilities in monitoring and evaluating impinged fish
species. In fact, EPA does not expect that many facilities will elect to comply with the
impingement mortality BTA standard via 40 CFR 125.94(c)(7) due to the added
monitoring burden. As illustrated in the discussion above, EPA evaluated
Subcategorization based on fish species or species attributes and concluded that separate
standards based on fish species would be complex, burdensome, and likely unworkable.
5.9.8 Other Factors
EPA also explored (in varying degrees of depth) and ultimately rejected a number of
other potential approaches to subcategories. These analyses included an evaluation of
creating subcategories based on the following:
• Spawning period (see DCN 10-6702)
• Combined cycle (see DCN 10-6631)
• Cogeneration (see DCN 10-6630)
• Dry cooling (see DCN 10-6679)
• 7Q10 of the source waterbody
• Flue gas desulphurization (see DCN 10-6681)
Because these factors were only applicable to a limited number of facilities, EPA found
these factors would not improve setting and implementing national standards.
5.10 Conclusion
As shown in the analyses above, EPA has examined numerous aspects of existing
facilities, including both production-related and CWIS-related characteristics, and has
determined that although these facilities exhibit a range of characteristics, these
characteristics do not differ to the extent that different technologies are most effective or
uniquely available to distinct subcategories of facilities. EPA's analysis demonstrates that
several CWIS technologies are effective for existing facilities and that these technologies
do not differ significantly across the various subcategory criteria considered. Therefore,
EPA is not establishing any subcategories for the final rule.
Although no subcategories were identified, the rule does reflect the key factors and
variability that are relevant to CWIS impacts. The rule establishes basic standards for the
reduction of impingement mortality and entrainment. It also provides several compliance
alternatives that reflect technologies that can be used to minimize adverse impacts and
that are to be implemented on a site-specific basis in accordance with the characteristics
of a specific facility (e.g., location, size, existing technologies, etc.). In this way, the
structure of the rule is consistent with the data identified for existing facilities.
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 6: Technologies and Control Measures
Chapter 6: Technologies and Control Measures
6.0 Introduction
In developing the 2004 Phase II rule and 2006 Phase III rule, EPA conducted a
comprehensive review of technologies that reduce impingement and entrainment (I&E) at
cooling water intake structures.78 For the existing facility rule, EPA reconsidered existing
information on these technologies, identified new technologies, and updated efficacy
information based on new study data.79 This chapter describes the primary technologies
and operational measures considered in developing requirements for the existing facility
rule. Each section provides an overview of the technology, a discussion of performance
in reducing impingement and/or entrainment, and examples of facilities and/or laboratory
studies that employ the technology.
In general, technologies and control measures can be divided into two major groups: flow
reduction and screening or exclusion. Flow reduction is the clearest way to reduce
impingement mortality and entrainment mortality, as lower intake flows will impinge and
entrain fewer organisms, generally in proportion to the amount of flow reduction. Screens
act to exclude organisms from the intake structure and return them to the source
waterbody. Exhibit 6-1 lists the technologies and control measures discussed in this
chapter.
In addition to this chapter, the Electric Power Research Institute's (EPRI) 2007 Fish
Protection at Cooling Water Intakes: A Technical Reference Manual (DCN 10-6813) is a
compilation of studies conducted at various sites throughout the country and serves as a
comprehensive reference for cooling water intake technology performance. For additional
discussion of cooling towers, see Chapter 8 of EPRI (2007) and the California Ocean
Protection Council's California's Coastal Power Plants: Alternate Cooling System
Analysis (DCN 10-6964).
In general, all of the technologies presented in this chapter can be effective at a given site
and are equally available at both power plants and manufacturers, as well as for existing
facilities (including new units at existing facilities) and new facilities. A cooling water
intake structure is a technical apparatus that is designed to supply water; the end use of
the water is of little importance when evaluating the CWIS's effectiveness or the
feasibility of a given technology. There will certainly be site-specific factors that weigh
heavily in evaluating technologies but the type of "downstream" user of cooling water is
generally not relevant. In the case of manufacturers, there are also greater opportunities
for flow reduction and reuse of cooling water.
78 See Chapter 3 of the 2002 Phase II proposed rule (DCN 4-0004), Chapter 4 of the 2004 Phase II final
rule TDD (DCN 6-0004), and Chapter 8 of the proposed Phase III rule (DCN 7-0004).
79
See Chapter 2 of the TDD for a discussion of data collection efforts.
6-1
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Chapter 6: Technologies and Control Measures
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 6-1. List of technologies considered
Flow reduction technologies and control measures
Closed-cycle recirculating systems
Wet cooling systems
Dry cooling systems
Variable speed pumps/variable frequency drives
Seasonal flow reductions
Water reuse
Alternate cooling water sources
Screening technologies
Conventional traveling screen
Modified coarse mesh traveling screen
Geiger screen
Hydrolox screen
Beaudrey W Intake Protection (WIP) screen
Coarse mesh cylindrical wedgewire screen
Fine mesh traveling screen
Fine mesh wedgewire screen
Barrier net
Aquatic filter barrier
Offshore intakes
• Intake location
• Velocity cap
Other technologies and operational measures
• Physical design
• Reduced intake velocity
• Substratum intakes
• Louvers
6.1 Flow Reduction Technologies and Control Measures
This section describes technologies and control measures used to reduce cooling water
intake flows. By reducing the intake flow, a facility can reduce its I&E; impingement is
related to intake flow (among other variables) and entrainment is directly proportional to
flow. The largest reductions are usually realized by installing (or retrofitting) a closed-
cycle recirculating cooling system but facilities may also employ variable speed pumps,
seasonal flow reductions, water reuse, or use of alternate sources of cooling water.
6.1.1 Closed-Cycle Recirculating Systems
Closed-cycle cooling systems transfer a facility's waste heat to the environment and
recycle the cooled water back to the condensers to be used again. These recirculating
systems enable a facility to withdraw significantly smaller quantities of (or in some cases
no) surface water. Closed-cycle cooling systems include cooling towers and cooling
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 6: Technologies and Control Measures
lakes/ponds.80 Cooling towers are structures that recirculate water within the cooling
system, while providing for the exhaust of excess heat. Towers are generally of two
designs: mechanical draft, in which heated water is exposed to air currents driven by
electrical fans, or natural draft, in which heated water is allowed to interact with naturally
induced drafts within the tower. In both cases, water within the cooling system is cooled
and sent back to the condenser to be used again. Approximately 28 percent of existing
power producers and 35 percent of existing manufacturers use cooling towers.
Due to the evaporative processes involved (and the subsequent buildup of dissolved
solids), cooling towers require that a certain portion of the circulating water be
discharged (as "blowdown") and replaced (makeup water).81
Cooling ponds (called "impoundments" in the final rule) are surface waterbodies that
serve as both a source of cooling water and a heat sink. As with cooling towers, cooling
ponds rely on evaporative cooling to dissipate the waste heat. Depending on local
hydrology, cooling ponds may also require makeup water from another waterbody (the
level of makeup water depends on numerous site-specific factors including size, inflow
and outflow, and evaporation; EPA has not identified a source of data that describes
cooling pond makeup flows). At many facilities, cooling ponds have evolved to be more
than part of an industrial waste treatment process, as recreational fishing and other
designated uses have been established. This has created some confusion as to whether
they should be considered as part of a closed-cycle cooling system or as a source water.
See the preamble for more discussion on this topic.
There are two main types of cooling towers, wet cooling and dry cooling. Each of these
technologies is described below.
6.1.1.1 Wet Cooling Systems
In a wet cooling system, waste heat is primarily transferred through evaporation of some
of the heated water into the surrounding air.82 This process enables a facility to re-use the
remaining water, thereby reducing the quantity of water that must be withdrawn from a
waterbody. While the amount of water withdrawn from the water source is greatly
reduced, it is not eliminated completely because makeup water is required to replace
water lost through evaporation and blowdown. There are two main types of wet cooling
systems: natural draft and mechanical.
A natural draft cooling tower is tall (up to 500 feet or more) and has a hyperbolic shape
which resembles a wide, curved smoke stack (see Exhibit 6-2). The height of these
towers creates a temperature differential between the top and bottom of the tower,
creating a natural chimney effect. Because of this effect, natural draft towers do not need
Note that the term "cooling pond" (or "impoundment" as stated in the final rule) is often used or defined
broadly, but under the final rule, not all cooling ponds are considered to employ closed-cycle cooling. See
the preamble to the final rule for additional discussion.
81 The frequency at which blowdown occurs depends on the source waterbody; fresh water requires less
frequent blowdown than brackish water.
82 In addition, a smaller portion of the heat is also removed through direct contact between the warm water
and the cooler surroundings.
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Chapter 6: Technologies and Control Measures
§ 316(b) Existing Facilities Final Rule - TDD
fans in order to operate efficiently and, while they tend to cost more to build than
mechanical draft towers, natural draft towers cost less to operate due to reduced energy
requirements. Unlike natural draft towers, mechanical cooling towers rely on motorized
fans to draw air through the tower and into contact with the heated water. These towers
may be much shorter than natural draft cooling towers, typically ranging from 30 to
75 feet in height (see Exhibit 6-3), but may require more land area and reduce a facility's
net generating output due to the electricity required to operate the fans.
Inside both types of towers, cooling water is sprayed from nozzles and then passes
through fill media that enhances contact between the air and water. In natural draft
towers, the nozzles are located partway up the tower while in mechanical draft towers the
nozzles are located near the top. Both natural draft and mechanical cooling towers can
operate in freshwater or saltwater environments. Evaporation of cooling water in the
towers results in an increased concentration of dissolved solids in the makeup water. The
concentration in the recirculating water is controlled by constantly removing a portion as
blowdown. As a result of higher dissolved salt concentration, saltwater applications
typically require more blowdown and makeup water than freshwater applications, making
them less efficient in reducing water withdrawals.
Exhibit 6-2. Natural draft cooling towers at Chalk Point Generating Station,
Aquasco, MD
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 6: Technologies and Control Measures
Exhibit 6-3. Mechanical draft cooling towers at Logan Generating Plant,
Swedesboro, NJ
Alternative Configurations
Modular cooling tower units provide an additional cooling tower alternative. Modular
cooling towers resemble mechanical cooling towers, but are portable, typically rented for
short-term periods and quickly assembled (see Exhibit 6-4). Modular cooling tower units
have been used as temporary replacements for existing cooling tower systems that need
major repairs, for facilities that are subject to interruptions in the ability to withdraw
sufficient quantities of cooling water, and for facilities that require supplemental cooling
or flow reduction for only a portion of the year. EPA has determined that the use of
modular towers (on a temporary basis) could substantially reduce the effects of downtime
from retrofitting intake technologies at some facilities (see DCN 10-6677). Facilities that
would be able to install the modular towers may actually face no downtime at all, which
would eliminate a significant component of the costs of the rule and replace it with the
smaller, temporary cost of modular tower rentals. (See the EA for a discussion of the role
of downtime costs in EPA's estimation of national economic impacts.) Because EPA was
not able to estimate how many facilities would be able to employ these modular towers,
however, the Agency has not attempted to estimate the overall cost savings of using
them. As a result, EPA did not adjust its national cost estimates to include the use of
modular cooling towers.
Facilities also often utilize a "combination" cooling system, in which some portion of the
cooling system uses closed-cycle cooling.83 For example, a facility might have one unit
83 Approximately 8 percent of electric generators and 12 percent of manufacturers use combination
systems.
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operating with a once-through system and a second unit has a cooling tower. For the
purposes of costing and consideration of cooling tower retrofits, EPA considered these
facilities along with facilities that are fully once-through.
Exhibit 6-4. Modular cooling tower (image from Phoenix Equipment)
84
Facilities that face significant challenges in meeting thermal discharge limits may operate
"helper" cooling towers.85 These are typically mechanical draft towers that are not
associated with the cooling system itself; they simply withdraw heated effluent that is
discharged by the facility, evaporate heat, and return the water to the discharge point.
These systems do not reduce the overall intake flow. Harllee Branch is an example of
such a facility. (See DCN 10-6537 for EPA's site visit report to this facility.)
6.1.1.2 Dry Cooling Systems
Dry cooling systems completely eliminate the need for cooling water withdrawals. Unlike
wet cooling systems, in dry cooling systems, waste heat is transferred completely through
convection and radiation rather than evaporation. Dry cooling systems are in use at a
number of facilities in the United States and worldwide. (See DCNs 4-4023H, 10-6679
84 http://www.phxequip.com/equipment.4366/15-000-gpm-cooling-tower.aspx
85 See DCN 10-6676 for a detailed discussion of helper towers.
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 6: Technologies and Control Measures
and 10-6943.) Since 1990, dry cooling has been installed in at least one facility in every
EPA Region, with many being installed in the northeast (states with historically more
stringent regulatory regimes) and the west, where water resources (for once-through or
wet towers) are more limited. In the 1990s, most of the facilities that installed dry cooling
were small (less than 100MW for the dry-cooled unit). But in the past decade, dry
cooling has become more prevalent at much larger facilities, with virtually all dry-cooled
units being over 100MW and many 250MW and larger. According to data provided by
vendors (see DCN 10-6680), Mystic (MA) and Midlothian (TX) are among the largest
known dry-cooled units, at 500MW each (out of a pi ant-wide capacity of 1600MW and
1650 MW, respectively). Many inland facilities in California use dry cooling. The State
of New York issued a cooling water policy (CP-#52 - Best Technology Available (BTA)
for Cooling Water Intake Structures) in July 10, 2011 that sets dry cooling as the
performance goal for all new industrial facilities sited in the marine and coastal district
and along the Hudson River. Astoria II, a 575 MW combined cycle facility using dry
cooling built was recently built along the Hudson. Additionally, many new facilities are
being built with dry cooling, including the Warren County (VA) facility, a 1329 MW
combined cycle facility.
There are two main types of dry cooling systems: direct and indirect. Direct systems
function similar to a radiator in a car; the turbine exhaust steam passes to a fin tube array
where air is drawn across and heat is rejected, ultimately producing a condensate that is
returned for reuse in the turbine. The system is completely closed to the atmosphere and
there is no contact between the outside air and the steam or the resulting condensate (see
Exhibit 6-5). Indirect dry cooling requires a cooling tower but a surface condenser is
placed between the turbine exhaust and the tower. Heat is transferred to the circulating
medium in the condenser and dispersed to the atmosphere through the tower. However,
the difference between indirect dry cooling and a wet tower is that the water is not
exposed to the outside air.86
Dry cooling systems tend to be much more costly than wet cooling systems and
experience higher turbine efficiency losses during periods of high dry bulb temperatures.
Previous EPA estimates have put the relative capital costs of dry cooling at 5X to 10X
that of mechanical wet cooling systems. Recent data indicates that these costs may be
closer to the lower end of this range. A comparison of cost data for the Astoria II project
to EPA estimates indicate that costs for the dry tower component alone are about 4X
those for an equivalent wet cooling system.87
For the Phase II Rule, EPA estimated that the turbine efficiency loss penalty for dry
cooling versus wet cooling could range from an annual average of about 4 percent to a
summer maximum of 16 percent based on the increase in steam condensing temperatures.
Also, steam turbines have a maximum turbine steam exhaust backpressure limit which
should not be exceeded to prevent damage to the turbine blades. Most existing steam
Indirect dry cooling systems are substantially less efficient in rejecting heat than direct units; however,
most facilities that would choose to retrofit dry cooling would select an indirect system, as it would be able
to tie into the existing condenser at the facility.
87 A comparison of the reported cost to construct and erect the Astoria II air-cooled condensers of 38
Million Euros to the costs of a comparably sized wet cooling system using the EPA estimate unit cost for
the wet tower alone of $80/gpm results in a factor of approximately 4X.
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turbines are designed for the expected maximum operating condensing temperature of the
existing cooling system (e.g., once-through using surface water). During periods of high
dry bulb temperatures, the turbine exhaust back pressure of a retrofitted dry cooling
system would likely exceed the design value for existing turbines designed for once-
through cooling. When this happens the operator must reduce the amount of power being
generated to prevent damage. Such forced reductions in generating capacity (aka derate)
can increase the amount of power generation loss toi levels higher than the maximum
turbine efficiency losses described above which are based on differences in condensing
temperatures alone. This problem may also occur in retrofitted wet cooling system but is
much more pronounced for dry cooling. Replacement or upgrade of the steam turbines to
a design with a higher maximum exhaust backpressure is necessary to minimize such
generating capacity reductions.
Exhibit 6-5. Dry cooling tower (image from GEM Equipment)88
6.1.1.3 Performance of Cooling Towers
The use of cooling towers significantly reduces the withdrawals of cooling water, but
some makeup water is still withdrawn in wet cooling tower systems. In the 2004 Phase II
rule, EPA estimated facilities employing freshwater cooling towers and saltwater cooling
88
http://www.gemindia.com/products/dct h.png
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Chapter 6: Technologies and Control Measures
towers would achieve flow reductions, and therefore associated entrainment and
impingement mortality reductions, of 98 percent and 70-96 percent, respectively.89
Facilities can also optimize the reduction in flow by also minimizing the makeup flow
withdrawals. The most common concept used to describe the level of optimization is
cycles of concentration (COC). This represents the ratio of dissolved solids in the
recirculated water versus that in the makeup water. Operating at a higher COC usually
requires additional O&M, such as an increased use of chemicals. In the 2004 Phase II
rule, EPA's record demonstrated saltwater cooling towers typically operated at 1.1-2.0
cycles of concentration.
However, more recent information demonstrates that, as a result of advances in design
and operation, saltwater cooling towers typically operate at 1.5 cycles of concentration
and 3.0 cycles for freshwater towers. See DCN 10-6964. These levels correspond to flow
reductions of 94.9 percent and 97.5 percent respectively (at a delta T of 20°F, which is
common for power plants and is in the center of the range observed by EPA).90 Exhibit
6-6 shows the reductions in flow for various waterbody types, cooling system
configurations and COCs; the vertical lines represent the two COCs used by EPA in its
analyses. See DCNs 10-6673 and 10-6674 for a detailed discussion of cooling tower
optimization.
Exhibit 6-6. Percent reduction in flow for various cooling system delta Ts
c
o
"•5
O
3
a>
S
a>
a.
100%
95%
90%
85% -
80%
75% -
70%
Delta T= 10 F
Delta T= 15 F
Delta T = 20 F
Delta T = 25 F
Delta T = 30 F
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0
Cycles of Concentration
89 As discussed in the preamble to the rule, impingement mortality and entrainment reductions are
proportional to flow reductions.
90 In the final rule, EPA did not include explicit requirements for COC or for a percent flow reduction, but
EPA continues to believe that these thresholds represent a properly operated and maintained cooling tower.
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6.1.1.4 Retrofit Applications
EPA estimated retrofit costs as described in Chapter 8 of this TDD and in the preamble.
Engineering factors affecting the retrofit from once-through systems to cooling towers
include the following:
• Availability of space nearby;
• Need to remove or demolish existing structures;
• Whether the tower site elevation is higher than the existing cooling system intake
bay so cold water can flow by gravity to the intake bay;
• Whether there are underground interferences in the path of the new circulating
water lines or at the location of the hot water sump and new circulating water
pumps;
• Whether the tower site has overhead interferences, including transmissions lines;
• Whether the tower design may have to work around excluded areas where
activities that may not be moved or blocked occur (e.g., hazardous materials
storage, large vehicle turn-around areas, and security areas);
• The degree of construction work needed to convert the existing intake to handle
the much lower intake flow volume needed for makeup water;
• How difficult it will be to tie-in the towers to the existing cooling system;
• Whether the site has unfavorable soil or geological conditions;
• Whether the site has contamination that might require remediation;
• Nuclear safety concerns;91
• Effects to manufacturing processes;
• Potential for increased water treatment and effects on facility's effluent; and
• Land use or zoning conflicts.
Net construction downtimes for retrofitting to cooling towers are estimated to be
approximately four weeks for non-nuclear plants and seven months for nuclear plants
(68 FR 13526). These estimates assume that the construction tie-in would be scheduled to
coincide with the facility's routinely scheduled maintenance (typically a four week
outage), thereby reducing the total length of the downtime for tie-in. See Chapter 8 for a
detailed discussion of how downtime is calculated and incorporated into the analysis of
cost.
91 While nuclear safety remains a paramount concern, it is less clear that retrofitting a cooling tower would
actually have any impact on the safety of the facility. Documentation submitted to the Atomic Energy
Commission from Palisades Plant (the lone nuclear facility to undergo a closed-cycle retrofit) indicates that
"[t]he existing cooling water system [...] has no safety related functions and the modified system will
likewise have no safety related functions." See DCN 10-6888B.
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The operation of cooling towers also leads to an energy penalty; an auxiliary power
requirement due to operating the cooling fans and additional pumping requirements92 and
a turbine efficiency penalty based on the incremental loss of performance due to a change
in the pressure of the steam produced within the generating unit.
As described in Chapter 10 of this TDD, non water-quality impacts may also result from
the installation of cooling towers. These impacts may include noise, plume, and salt drift.
See Chapter 10 for a discussion of these potential impacts.
EPRI has also released a document which quantifies environmental and social effects of
conversions to closed-cycle for 24 facilities along with national estimates based on data
for the 24 facilities and a questionnaire issued to the industry , Net Environmental and
Social Effects of Retrofitting Power Plants with Once-Through Cooling to Closed-Cycle
Cooling. EPRI Technical Report 1022760, July 2011 (DCN 12-6942)
Dry cooling towers (and the accompanying equipment) will generally occupy the same or
greater footprint as wet towers, potentially exacerbating any issues with available space.
Additionally, existing facilities might need to upgrade or modify existing turbines,
condensers, and/or cooling water conduit systems, which are tasks that are typically not
required for wet tower retrofits. As with wet towers, retrofitting a dry cooling tower at an
existing facility would require extensive shutdown periods during which the facility
would lose both production and revenues, and decrease the thermal efficiency of an
electric generating facility. As stated in the preamble to the 2004 Phase II rule,93 EPA
does not believe that dry cooling is a viable alternative for reducing impingement and
entrainment at a national scale; dry cooling offers substantial reductions in impingement
and entrainment (exceeding the performance of wet cooling in that regard) but with a
significantly higher cost and penalty to performance.
Factors To Consider In A Closed-Cycle Retrofit
As described in the preamble to the final rule, EPA is not requiring closed-cycle cooling
on a national scale; in part, this is due to the impact of three factors: land availability, air
increased air emissions, and remaining useful life of the facility. These factors, plus other
considerations (including effects to reliability) affecting this determination, are discussed
in detail in the preamble.
Land Availability: While the majority of facilities report what appears to be adequate
available land for placement of cooling towers, some facilities may have legitimate
feasibility constraints due to small sites, existing equipment, buildings, transmission
yards, rail lines, challenging topography or other factors. Based on site visits, EPA has
seen several facilities that have been able to engineer solutions when faced with limited
available land. On the other hand, EPA found that some facilities with large sites that still
could not feasibly install cooling towers due to, for example, protected wetlands. As
described in Chapter 5, EPA attempted to numerically analyze land availability but lacks
92 Power plants already use a considerable amount of electrical energy for auxiliary purposes. The
additional power required for cooling tower fans and pumping is equal to roughly 20 percent of the existing
auxiliary power use.
93 See 69 FR 41608.
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adequate data to better analyze how land constraints can be accommodated at existing
facilities.
Increased Air Emissions: Retrofitting to closed-cycle cooling results in an energy
penalty, which in turn leads to increased air emissions. Fossil-fueled facilities may need
to burn additional fuel (thereby emitting additional CC>2, SC>2, NOx, and Hg) for two
reasons: 1) to compensate for energy required to operate cooling towers, and 2) the
slightly lower generating efficiency attributed to higher turbine back pressure. At new
units, these impacts are much less, as the design of a new cooling system accounts for
these issues. U.S. fleet efficiency will likely increase over the long term, resulting in
lower base emissions on a per watt basis, and the turbine back pressure penalty will be
further reduced resulting in lower incremental emissions. EPA is also aware that nuclear
facilities would also need to compensate for energy required to operate cooling towers
and for the turbine back pressure energy penalty. The impact of the increased emissions
varies based on the local circumstances. For example, EPA's analysis suggests that
increased emissions of PM2 5 may result in difficulty in obtaining air permits in those
localities designated as non-attainment areas. For PMio, see DCN 10-6954, which states
that emissions would be approximately 60 tons per year if all drift is PMi0. This
document also noted minor drift management issues onsite at facilities using salt water
cooling towers and no negative consequences off-site. See Chapter 10 of the TDD for
more information.
Remaining Useful Life of the Facility: As described in the preamble, many existing
facilities have been operating for 30 to 50 years or longer. Making major structural and
operational changes (such as retrofitting to closed-cycle cooling) may not be an
appropriate response for a facility or unit that will not be operating in the near future. The
remaining useful life of many of these units is uncertain, as this relationship is not based
solely on plant age, because plant age alone does not discern those facilities that have
completed an uprate, recently repowered, or completed other major facility modifications
to individual units.
6.1.1.5 Examples of Cooling Towers
An estimated 374 existing facilities currently employ either a fully or partially
recirculating cooling system using wet cooling towers. EPA has identified a number of
power plants that have converted to closed-cycle recirculating wet cooling tower systems.
Many of these facilities (including Palisades Nuclear Plant in Michigan, Jefferies
Generating Station and Canadys Station in South Carolina, McDonough and Yates in
Georgia) converted from once-through to closed-cycle wet cooling tower systems after
significant periods of operation utilizing the once-through system. Another facility,
Pittsburg Unit 7, converted from a recirculating spray-canal system to a closed-cycle wet
cooling tower system. In this case, the conversion occurred after approximately four
years of operation utilizing the original design. Detailed case studies of these retrofit
efforts are found in Chapter 4 of the TDD for the 2002 proposed Phase II rule (DCN
4-0004) and in the site visit reports available in the docket for the existing facility rule.
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Additionally, Brayton Point Generating Station in Somerset MA completed construction
of two natural draft cooling towers as part of its retrofit from once-through cooling to
closed-cycle cooling.94 The towers began operations in 2011 and 2012.
As discussed in DCN 3-3029-R6 from the Phase I docket, the data from the industry
survey indicates that newer facilities and units are trending towards the use of closed-
cycle cooling.
6.1.2 Variable Speed Pumps/Variable Frequency Drives
At their design maximum, a facility with variable speed pumps (VSPs) or variable
frequency drives (VFDs) can withdraw the same volume of water as a conventional
circulating water pump. However, unlike a conventional (i.e., single speed) circulating
water pump, VSPs and VFDs allow a facility to reduce the volume of water being
withdrawn for certain time periods. The pump speed can be adjusted to tailor water
withdrawals to suit the cooling water needs for a specific time.95 See DCN 10-6602 for
more information.
A reduced flow volume will result in reduced O&M costs as a result of the reduction in
pump energy requirements. Depending on site-specific conditions, this reduction may
allow the facility to recover the initial capital investment sooner and produce savings
thereafter. In fact, VSPs are often employed in industrial systems solely for their
economic benefit. In the case of water intakes, the reduction in flow volume has the
added benefit of reducing impingement and entrainment impacts.
VSPs can be used to reduce flow volume even during periods of peak power generation,
but there are operational limitations and consequences associated with this flow reduction
technology. These limitations include:
• Inherent limits of the technology that, based on system characteristics, may
restrict pump operation to a specified flow range to prevent damage to the pump.
The system hydraulic characteristics will also affect the amount of savings in
pump energy cost;
• Limits in flow reduction associated with NPDES permit thermal discharge limits,
since a decrease in flow will result in an increase in the temperature of the
effluent; and
• Economic consequences of reduced plant generation output resulting from
reduced turbine efficiency associated with higher condenser temperatures.
94 See http://www.epa.gov/ne/bravtonpoint/index.html for details.
95 Cooling systems are designed to enable the facility to meet its cooling needs at maximum operations
under adverse environmental conditions (such as a warm source waterbody). The amount of heat the
facility needs to reject is a known value; depending on several factors, the facility actually may not need to
operate its pumps at full speed; there may be an intermediate flow rate that is sufficient to remove the heat
being generated. Facilities with multiple pumps could also choose to operate fewer than normal pumps,
perhaps reducing the value of VSPs.
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The latter two limitations are more of a concern during periods when the source water is
warmer, and will also tend to limit flow reduction during periods when the system is
operating at peak capacity.
Retrofit Applications
A VSP retrofit involves replacing fixed speed intake pumps with variable speed pumps.
At a minimum, this involves the installation of a variable frequency drive (VFD) and
replacement of the pump motor, switches, and controller. In many cases, this may be all
that is needed. A variable frequency drive is an electronic device that varies the pump
motor speed by varying the electrical frequency of the AC power delivered to the pump
motor. In some cases, the existing motor may not be designed to handle the added
harmonic electric currents associated with this type of system. In such cases, the pump
motor may need to be derated (the maximum power output and flow rate is reduced) or
the motor will need to be replaced. Additionally, the pump itself may require replacement
if the existing pump hydraulic characteristics place too many limitations on the amount of
flow reduction that can be obtained. If multiple pumps are operated simultaneously and in
parallel, it is best to retrofit all of the pumps.
The use of VFDs allows the flow through the pumps to be controlled over a range of flow
volumes, thus allowing the flow volume to be tailored to the plant operating conditions.
With proper control, the effect on turbine efficiency can be minimized and the effluent
temperature can be maintained within the NPDES permit temperature limits. This allows
the facility full flexibility to effect both small and moderate flow volume reductions when
conditions allow.
During the winter months, use of flow reduction can actually result in an increase in
turbine efficiency by eliminating subcooling in the condensers. Subcooling occurs when
the steam condensate in the condenser is cooled excessively, resulting in the system's
consumption of additional heat to bring the condensate back up to the boiling temperature
when it is recycled back to the boilers. Excessive subcooling can also result in the
formation of condensed water droplets within the last stage of the turbine, which can
damage the turbine blades. Measures to control excessive subcooling include the flow
reduction methods described above for fixed speed pumps, as well as piping
configurations that can bypass a portion of the flow around the condensers and piping
configurations that can recirculate condenser outflow back to the pump inlet. In the latter
case, some flow reduction is already occurring but pumping energy requirements are not
reduced. The control of subcooling, especially slight to moderate subcooling that might
otherwise be tolerated, provides another economic benefit for VSP retrofits through
increased plant power output.
6.1.2.1 Performance and Operational Limitations
There are technical limitations to the amount of volume reduction that can be achieved
with VSPs. For any pump, as the speed is reduced, there is a point reached where the
pump's output head is equal to the system's static head, resulting in zero flow.
Continuous operation at such a condition must be avoided because the impeller will
continue to spin and the water will recirculate within the pump casing, resulting in
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damage to the pump. The flow volume response to varying speed is unique for every
combination of pump and system hydraulics, and thus the minimum safe speed must be
calculated for each application to avoid operation at or even near the shutoff head.
System controls are set such that the minimum pump speed will be well above that which
produces zero flow conditions. Two power plants in California (Pittsburg and Contra
Costa) have installed VSPs and documentation indicated that as much as a 50 percent
reduction in flow was attainable. However, this level of flow reduction is usually high
and typical flow reduction rates are from 8-15 percent, with some variability depending
on whether the facility is baseload or load following.
One important system characteristic that affects the performance of VSPs is whether the
total pumping head is predominantly the result of losses from friction or to static head.
Where the pumping head is predominantly from friction losses, the flow reduction
capability of VSPs is greater and overall system efficiency at reduced flows will be
greater. An example of a system where friction losses are a large component of the
pumping head would be a system that uses an inverted siphon configuration. Inverted
siphon configurations are often used in once-through systems where the condenser
elevation is close to the water surface, because they are well worth the savings in pump
energy requirements associated with the siphon configuration. Such systems require
vacuum pumps to remove the gases that collect in the high points. To prevent water vapor
from forming under the vacuum conditions that form within the siphon, the height of the
inverted siphon is limited. If the condenser elevation is above the maximum siphon
height, then the siphon height is shortened by exposing the downstream end to the air at
an elevation above that of the source water in a structure called a seal pit. Facilities where
the condensers are located well above the water surface will have higher static
components of the pumping head even when inverted siphons are used. Thus, the
condenser elevation and piping configuration will affect the performance of VSPs.
In systems where the pumping head is predominantly static head, as the pump speed is
reduced a point is soon reached where small changes in speed can result in large changes
in flow rate, especially as the pumping head approaches the system static head as
described above. Thus, the available range of flow reduction is much lower than in
systems where the pumping head is mostly friction losses. Also, in systems where the
pumping head is predominantly static head, the pump efficiency drops substantially with
reduced speed. Such systems will experience much less power usage savings. Thus, use
of VSPs in such systems is less advantageous. In these high static head systems, the
pump and system hydraulic characteristics must be carefully evaluated before deciding
whether the available benefits outweigh the costs.
When the turbine system is operating at a given generation rate (i.e., a constant steam
load), a reduction of the cooling water flow volume will result in a proportional increase
in the condenser temperatures. This will result in an increase in the difference in cooling
water temperature between the condenser inlet and the condenser outlet (AT). Many
facilities have NPDES permit conditions that set a maximum limit for the AT value. This
effectively places a practical limit on the amount of flow reduction that can be achieved.
During warmer months, the increase in condenser temperature will also result in a higher
turbine exhaust pressure, resulting in a reduction in turbine efficiency. Thus, there is a
competing economic incentive to maintain higher flow levels.
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Many facilities have NPDES permit conditions that set a maximum effluent temperature,
which may put additional limitations on the availability of flow reduction through
variable speed pumping, especially during summer months, regardless of the economic
considerations. In fact, under extreme summer conditions, some facilities may be
required to maintain the cooling water flow at full capacity while having to reduce power
output (derate) in order to meet temperature limits.
VSPs can reduce the facility's intake flow, which is one of the most effective ways to
reduce impingement and entrainment. However, as described above, the amount of flow
reduction that can be achieved has both operational and seasonal limitations. In general,
opportunities for flow reduction are greater during cooler months and thus the benefits of
I&E reductions may be enhanced or reduced depending on the timing of the seasonal
variations in the presence and behavior of the various life stages of the affected aquatic
organisms.
Applicability
Flow reduction through the use of VSPs alone may not be sufficient to result in sufficient
I&E reductions. Because of the economic benefit associated with reduced pumping
energy requirements, VSPs may be useful even when the other technologies are fully
capable of meeting the I&E requirements alone and when the presence of sensitive
organisms coincides with the period when the source water is warmest.
The capital costs of VSP retrofit will be dependent on which components of the pumps
need to be replaced; it should be assumed, at a minimum, that a retrofit will include
replacement of the pump motors. Given the savings in pump energy costs associated with
VSPs, the net operating costs should be negative in most applications (i.e., savings in
pump energy costs will exceed any maintenance costs). Actual savings will be highly
variable depending on the system hydraulic conditions, the plant operating schedule, and
the degree of flow reduction attained. If conditions are favorable, the net operating
savings will offset capital costs (i.e., the technology will pay for itself). However, if flow
volume reduction is aggressively sought, then pump energy savings will be offset by
reduced plant output associated with a reduction in turbine efficiency.
VSPs will be most effective when:
• Facility capacity utilization rates are not very high;
• Cooling pump head is predominantly from friction losses and not static head; or
• They are combined with other I&E reduction technologies.
Technologies that could benefit from being paired with VSPs may include:
• Traveling screens
• Fish barrier net
• Velocity cap
Since reduced flow volume will result in a reduction in the approach and through-screen
velocities, VSPs will likely result in improved performance of velocity caps and traveling
screens, particularly those with high approach velocities.
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Chapter 6: Technologies and Control Measures
6.1.2.2 Examples of Variable Speed Pumps
Millstone Nuclear Plant
The Millstone Nuclear Plant on Long Island Sound in Connecticut has installed VFDs on
its circulating pumps. The goal is to reduce impingement and entrainment of winter
flounder which are present in greatest abundance in April and May (their spawning
season). The plant agreed to reduce their 2.2 BGD flow by 40 percent during this period.
Flow reduction is required from April 4 to June 5 or until the source water reaches 52°F
(whichever happens first). To facilitate this, the facility's NPDES permit96 allows for
increase in discharge AT for this period (see Exhibit 6-7 below) while retaining the limit
of 4°F increase outside mixing zone.
This example is noteworthy for several reasons: first, the facility is a nuclear plant and
second, it is a baseload facility. As discussed in the preamble, nuclear facilities may have
additional safety considerations when assessing technologies to minimize impingement
and entrainment, but VSPs appear to not trigger any concern. Second, baseload plants are
arguably the least able to reduce flow using VFD technology, as they are typically
operating continuously and have relatively constant demands for heat rejection. However,
Millstone appears to be able to capitalize on the cooler source water temperatures in these
months and balance the needs of heat rejection and impingement and entrainment.
Exhibit 6-7 shows the revisions in permit's AT limits. Calculated reductions were
supplemented with data from PCS (the reported actual monthly max AT during Apr-May
period was in the low-mid 20s). Using a AT value of 24 compared to 41 results in a 41
percent reduction, assuming the facility is able to tailor their intake flow to operate close
to the seasonal temperature limit.
Exhibit 6-7. Flow reduction at Millstone
Millstone Nuclear
Unit 2 Condenser
Unit 3 Condenser
Combined discharge
Typical seasonal max from PCS
Normal AT limit
Deg F
32
28
32
24
Seasonal VFD AT
limit
Deg F
46
38
41
41
Calculated
reduction in
intake flow
30%
26%
22%
41%
6.1.3 Seasonal Flow Reductions
Seasonal flow reduction refers to the reduction or elimination of a quantity of water being
withdrawn during certain biologically important time periods. Most facilities that practice
seasonal flow reductions do so in order to reduce entrainment because entrainment often
peaks during specific times of the year (i.e., during spawning season). Typically, this
means that a facility produces less energy or no energy for some portion of the year
1 See http://www.epa.gov/regionl/npdes/permits/2010/finalct0003263permit.pdf.
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thereby reducing or eliminating the volume of cooling water it requires. This may be
accomplished through a variable speed drive or pump or shutting down some portion or
all of the pumping system (and unit).
See DCN 10-6702 for specific examples of spawning periods at existing facilities. In
these examples, there are often organisms that have some degree of spawning at all times
of the year but peak spawning periods can be identified. If only certain species are
examined, the spawning period analysis may appear very different than a broader
analysis of all species present.
Additionally, the specific timing and abundance of organisms present may affect how
seasonal flow reductions are achieved. As an example, Exhibit 6-8 below presents two
possible scenarios that might be addressed differently under a seasonal flow reduction
approach.
Exhibit 6-8. Examples of seasonal flow reductions
-Speciesl
-Species2
Total Entrainables
-Speciesl
-Species2
Total Entrainables
Because of the difficulty in projecting, on a national scale, which facilities might employ
seasonal flow reductions (due to the species present, seasonal utilization rates, percentage
of flow reduced and other factors); EPA did not include seasonal flow reductions in any
formal analysis of compliance costs.
6.1.4 Water Reuse
EPA encourages any reduction in water withdrawals or water usage in general (see "EPA
2012 Guidelines for Water Reuse" DCN 12-6848). Throughout the 316(b) rulemaking
process, EPA has included provisions for water reuse whereby a facility that uses water
withdrawn for another purpose (e.g., contact cooling or process water) as cooling water,
then said volume would not be considered in determining whether a facility is subject to
the regulation.97
For power plants, water reuse (outside of closed-cycle cooling) is typically not an
available option, as there is very little water that is used for purposes other than non-
contact cooling; the "credit" would be extremely small. EPA has seen examples where
cooling water is reused in air pollution control processes.
97
See, e.g., 40 CFR 125.83 (definition of cooling water).
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 6: Technologies and Control Measures
Manufacturers, on the other hand, may realize substantial benefits from water reuse. As
discussed above, a facility may avoid national 316(b) requirements if it reuses a
significant portion of its cooling water and does not meet the 25 percent threshold.
Additionally, the final rule provides that entrainment requirements at new units at an
existing facility do not apply to cooling water that is reused for another purpose. See the
preamble for the final rule for more information on how EPA considered water reuse in
the regulatory framework.98
6.1.5 Alternate Cooling Water Sources
Cooling water need not be withdrawn from a surface waterbody. Groundwater, grey
water (i.e., POTW effluent) or other sources of water may be used for once-through
cooling or as makeup water for a closed-cycle system. EPA supports the use of
alternative sources since they can often be used to displace (reduce) all or a portion of the
requirement to withdraw surface water. Unfortunately, many facilities have cooling needs
that substantially outpace the volume of water available to them from alternate sources,
especially for once-through cooling systems. In the California's Coastal Power Plants:
Alternate Cooling System Analysis., OPC analyzed alternate sources as cooling tower
makeup water but concluded that even for power plants located in densely populated
areas of southern California (where infrastructure to facilitate alternate sources such as
grey water may already exist), alternate sources of cooling water were not a viable option
for most, if not all, facilities (see DCN 6631). Similarly, EPA did not consider any
regulatory analyses or alternatives that relied on alternative cooling water sources.
6.2 Screening Technologies
Screening technologies have been used on cooling water intake structures for more than
75 years to prevent debris and aquatic organisms from entering the condensers. These
technologies include both traveling screens and passive screens. Over 93 percent of
power plants and 73 percent of manufacturers use some sort of screening technology (see
Chapter 4 of this TDD).
Exhibit 6-9 provides a generic diagram of a cooling water intake structure that employs
traveling screens, with the power plant operations and cooling water discharge also
shown.
98 Also see Chapter 8 of the TDD for information on how EPA considered the relationship between non-
contact cooling water, contact cooling water, and process water flows in developing compliance costs.
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Exhibit 6-9. Generic CWIS with traveling screens
Traveling Screens
Fixed Bar Racks
Power Plant
Traveling screens (see Exhibits 6-10 and 6-11) are used at most cooling water intake
structures. These screens were originally designed for debris control, but also serve to
prevent some fish and shellfish from entering the cooling system. Traveling screens have
been installed in numerous environmental conditions: salt water, brackish water, fresh
water, and icy water. There are many types of traveling screens (e.g., through-flow, dual-
flow, center-flow). The most common design in the US is the through-flow system. The
screens are typically installed behind bar racks (trash racks) but in front of the water
circulation pumps. The screens rotate up and out of the water where debris (including
impinged organisms) is removed from the screen surface by a high pressure spray wash.
Screenwash cycles are triggered manually, on a timer, or by a certain level of head loss
across the screen (indicating clogging). By design, this technology works by collecting
(i.e., impinging) fish and shellfish on the screen.
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Chapter 6: Technologies and Control Measures
Exhibit 6-10. Traveling screen at Eddystone Generating Station, Eddystone, PA
<•' J
Exhibit 6-11. Traveling screen diagram
LOW PRESSURE
FISH WASHING
SYSTEM
DEFLECTOR
PUTE
NEOPRENE
DEFLECTOR
FISH
SLUICE
TROUGH
CONVENTIONAL
HIGH PRESSURE
SPRAY
SIDE ELEVATION
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Passive screens are non-moving fixed screens that use physical exclusion and
hydrodynamics to minimize debris and fish from entering the condensers and to prevent
the buildup of debris and screen loading leading to head loss. Passive screens include
wedgewire screens, perforated pipes, and porous dikes/leaky dam systems. Wedgewire
screens are the most common type of passive screen and the most effective passive screen
at minimizing impingement and entrainment (see Exhibit 6-12). Wedgewire screens are
discussed in more detail later in this chapter.
Perforated pipes are pipes with holes bored in them, allowing water withdrawals to occur
along the length of the pipe instead of at the open end. This technology is not common, as
it may be prone to clogging. Due to the uncommon usage, EPA did not examine this
technology in detail nor study its performance. See Chapter 4 of the 2004 Phase II TDD
for more information.
Porous dikes and leaky dams are structures (such as a weir or jetty made of riprap) that
physically separate the intake from the source water. Intake flow is drawn through the
dike into a forebay or lagoon, where standard traveling screens or other technologies are
used. This technology is not common, in large part due to the limited volume of water
that can be drawn through the dike and the space required to build such a structure in the
source water. Due to the uncommon usage, EPA did not examine this technology in detail
nor study its performance. See Chapter 4 of the 2004 Phase II TDD for more information.
Exhibit 6-12. Cylindrical wedgewire screen
Traveling screens and passive screens are further defined by screen mesh size as coarse
mesh or fine mesh. Coarse mesh screens usually have mesh sizes of 3/8" (about 9.5 mm)
and fine mesh screens have mesh sizes typically ranging from about 0.5 mm to 3 mm,
depending on the organisms to be protected. Coarse mesh screens are generally not
protective of smaller organisms (such as eggs and larvae) that may become entrained by
passing through the screen openings and into the cooling system. Coarse mesh systems
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 6: Technologies and Control Measures
may also cause mortality of impinged fish due to impact, stress, descaling, and
suffocation against the screen. Fine mesh screens may prevent entrainment, but may also
lead to increased mortality of impinged organisms (specifically eggs and larvae that
would otherwise have been entrained).
The sections below discuss each screen type in greater detail.
6.2.1 Conventional Traveling Screens
Conventional traveling screens, also called coarse mesh traveling screens, are a common
component of virtually all cooling water intake structures and provide essential debris
and fouling control for pumps and condensers; over 83 percent of all existing facilities
already employ this type of screen." The screens are mounted on fixed-loop chains or
belts that rotate through the water column and remove debris from the intake stream,
preventing the entrainment of debris through the intake system where they can damage
sensitive pumps and condensers. Objects collected on the screen are typically removed
with a high-pressure spray (greater than 60 pounds per square inch [psi]) and deposited in
a dumpster or debris return trough for disposal. Screens are rotated and washed
periodically based on a set time interval or when the pressure differential between the
upstream and downstream faces exceeds a set value. Intermittent rotation minimizes
operational wear and tear and keeps maintenance costs relatively low. In the U.S.,
facilities employ multiple traveling screen types, including dual-, center-, and through-
flow designs. The through-flow type—the most common at U.S. facilities—removes
debris and screenings from the water on the upstream (ascending) side.
Conventional traveling screens were not originally designed with the intention of
protecting fish and aquatic organisms that become entrapped against them. Marine life
may become impinged against the screens from high intake velocities that prevent their
escape. Insufficiently hardy species or life stages may suffocate after prolonged contact
with the screens. Exposure to high pressure sprays and other screening debris may cause
significant injuries that result in latent mortality, or increase the susceptibility to
predation or reimpingement. Organisms that do survive initial impingement and removal
are not typically provided with a specifically-designed mechanism to return them to the
waterbody and are handled in the same fashion as other screening debris. These screens
do not address organism entrainment, as eggs and larvae are typically swept through the
screen and into the condensers.
Dual Flow Traveling Screens
Dual flow traveling screens, also known as double-entry single-exit screens, are a
variation of conventional through-flow traveling screens that are positioned such that the
screen face is parallel to the general direction of flow. Water enters through the outside
and exits through the center. These screens function in a similar manner to conventional
99 The percentage is based on responses to the industry questionnaire. Upon further review of facilities that
did not identify a traveling screen, EPA found that most of these facilities did in fact have traveling screens.
As a result, EPA assumes that virtually all existing facilities have a traveling screen at some point in their
cooling water intake system. The screen may be located in the forebay instead of at the cooling water intake
structure, but some form of screening is almost always necessary.
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traveling screens but have the advantage of screening water through the descending and
ascending screen faces which prevents any debris from carrying over to the downstream
side. Through-flow traveling screens can be replaced with dual-flow traveling screens
and if sufficient space is available in front of the screens can result in an overall increase
in screen area. Center-flow traveling screens, also known as single-entry double-exit
traveling screens, are similar to dual flow screens except that water enters through the
center and exists through the outside.
6.2.1.1 Technology Performance
Conventional screens are not used to mitigate the impacts of impingement and/or
entrainment.
6.2.1.2 Facility Examples
Conventional screens are used at a large number of existing facilities.
6.2.2 Modified Coarse Mesh Traveling Screens
Following the 1972 Clean Water Act's requirement to use technology-based solutions to
minimize adverse environmental impacts, some conventional coarse mesh traveling
screen systems were modified to reduce impingement mortality by removing fish trapped
against the screen and returning them to the receiving water with as few injuries as
possible. The modified screens, also known as "Ristroph" screens or modified Ristroph
screens, feature capture and release modifications that include a fish collection bucket or
trough, a low pressure spray, and a fish return system. In the simplest sense, these screens
are fitted with troughs (also referred to as buckets) containing water that catch the
organisms as they are sprayed off of the screen. The return component consists of a
gentle mechanism to remove impinged fish from the collection buckets, such as a low-
pressure spray. The buckets empty into a collection trough that returns fish to a suitable
area in the source waterbody. These modified "Ristroph" screens have shown significant
improvements in reducing impingement mortality compared with unmodified screen
systems. Of the 766 existing facility intakes that were reported in the detailed
questionnaires, 9 intakes specifically reported "Ristroph" traveling screens, 16 additional
intakes may qualify as having "Ristroph-type" traveling screens, 50 intakes reported
having "Fish Buckets, Baskets, or Trays," and 130 intakes reported an inlet or through-
screen screen velocity of < 0.5 fps.
The first Ristroph screens, named for the lead engineer who developed the initial
prototype, were installed at Dominion Power's Surry Station in Virginia in 1977. The
existing screen panels were fitted with water-retaining collection buckets at the base of
each panel that lifted impinged fish out of the main stream flow as the screens rotated. At
the top of the screen assembly, buckets emptied into a collection trough that returned fish
to a suitable area in the source waterbody. The initial survival rate for the modified screen
at Surry Station, averaged across all species, was 93.3 percent (EPRI 1999). Bay anchovy
had the lowest initial survival at 83 percent (White and Brehmer 1977, Pagano and Smith
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 6: Technologies and Control Measures
1977). Notably, these survival rates did not account for latent mortality that may have
resulted from injuries sustained during the collection and removal process.
Data from early applications of the "Ristroph" screen design showed that while initial
survival rates might be high at some installations, latent mortality rates were higher than
anticipated, indicating significant injuries could be sustained during the impingement and
return process that were not immediately fatal. Many of these flaws were identified in an
analysis of a modified screen design proposed for the Indian Point facility in New York
by Fletcher (1990; see DCN 5-4387). This analysis identified points in the
collection/removal process where latent injuries might be sustained, including poor debris
removal, which became entangled with impinged fish and prevented their safe return;
rough or corroded screen basket materials that increased descaling; and fish
reimpingement occurring when fish escaped the ascending buckets by jumping over the
outer bucket lip just prior to the bucket breaking the surface.
Most significantly, Fletcher identified a principal cause for many of the injuries sustained
by impinged fish. Screen panels retrofitted with water-retaining buckets induced a
secondary flow pattern in the bucket while it remained below the water line, creating
turbulent conditions in the bucket that repeatedly buffeted any fish against the screen and
bucket materials. Fletcher observed that fish caught in this flow pattern suffered far more
significant injuries than those which only came in contact with the screen mesh.
Several critical modifications were proposed following this analysis, many of which have
been adopted by other facilities, including:
• Redesign of collection buckets to address hydraulic buffeting with a new shape
and inclusion of a flow spoiler on the outer bucket edge. These modifications
minimize turbulence within the bucket area and prevent significant injuries during
capture and retention.
• Addition of a fish guard rail/barrier to prevent fish from escaping the collection
bucket and increasing their total impingement time. The fish guard rails extend
above the water surface before the main bucket as the screens are rotated.
• Reordered fish and debris removal. At Indian Point, filamentous debris collecting
on the screen panels was originally removed after impinged fish. This debris
blocked the screen panels, however, and prevented the fish removal spray system
from functioning properly. The modified design included a high pressure spray to
remove debris on the ascending side prior to removing impinged fish.
• Replaced screen panel materials with smooth woven mesh. Significant descaling
was observed with more abrasive screen designs such as crimped or welded wire.
A schematic comparison of each basket design type is shown in Exhibit 6-13.
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Chapter 6: Technologies and Control Measures § 316(b) Existing Facilities Final Rule - TDD
Exhibit 6-13. Ristroph and Fletcher basket designs
l, Screen \ Screen
\ Panel ^ Water Line >• \ Panel
\ \
' . / ' ' '. ' '-•. '' • /\. ''"': '• \ ^'./" . ' ^./" :
Auxiliary J* \ \
Screen V) \
x\. )
Bucket Spoiler ^~^^ Bucket
Original Ristroph Design Fletcher Modifications
The Fletcher study also evaluated impingement durations up to 30 minutes. Impingement
durations of 10 minutes or less did not significantly affect survival, with mortality rates
increasing with longer impingement times. Likewise, sufficient water retention in the
buckets was shown to be essential. Exposure to the air and temperature extremes, even
for a short duration, could negatively impact fish survival. These findings support the
general assumption that modified Ristroph screens must be continually rotated instead of
the periodic rotation schedule common with conventional screen systems.
6.2.2.1 Screen Design Elements
The collection portion of a modified Ristroph system comprises all CWIS elements
geared towards fish protection up to the point where fish are removed from the
screens/buckets. The collection system's key function is to capture entrapped fish that
cannot escape the intake screens and remove them from the intake flow for safe return to
the source waterbody. This must be accomplished by sustaining all captured fish with
sufficient water and minimizing potential injuries from screen interactions and
turbulence. While the cooling water intake structure location and orientation may play a
significant role in determining how many fish and shellfish are susceptible to
impingement before coming in contact with the screens, this subsection focuses on the
screens and fish return systems. EPA notes that a comprehensive design approach that
carefully considers the cooling water intake location and orientation prior to installing a
modified traveling screen system may yield significant benefits. At existing facilities,
however, many of these modifications are more problematic due to space constraints and
interference with existing systems, and may not be practical options given their cost and
complexity.
Screen Type/Design
The screen itself is the first point at which any fish will come in contact with a physical
element. When a conventional traveling screen is modified to include Ristroph and
Fletcher modifications, many of the system's existing elements may need to be upgraded
to incorporate newer, more fish-friendly materials, or with more robust mechanical
components that are better suited to the new operating conditions. New components like
fish buckets or rails also require careful consideration to maximize the desired level of
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 6: Technologies and Control Measures
protection. All of these factors must be evaluated against the specific demands at a
particular site such as water quality, intake velocity, and species composition and
abundance. In some cases, it may be more economical, and ultimately more efficient, to
replace the entire screen assembly rather than retrofit existing components. A
comprehensive retrofit may mitigate other effects and better enable all components to
work more efficiently with one another. 10°
Screen Mesh Material
The primary design focus for existing conventional traveling screen systems is the
removal of smaller debris (i.e., debris not screened by a trash rack) that may clog or
damage sensitive intake equipment like pumps and condensers. The screen panel material
is selected to serve this function while remaining durable and functional with the lowest
possible maintenance costs. Screen materials must be able to resist corrosion and
degradation while being alternately immersed in water and exposed to air. They must also
withstand potentially high debris loads that might compromise weaker materials and
damage the intake system. Stainless steel is among the most common screen material
used for traveling screen, although copper alloys are also used where screen fouling from
colonial organisms is a concern. Likewise, advances in engineered polymer coatings have
proven effective in resisting corrosion and degradation.
For a modified traveling screen system, materials and configurations that are smooth by
design and can maintain a near-design condition will assist in minimizing any contact
injuries sustained by impinged fish. Smoother configurations and materials, such as
woven wire mesh (as opposed to punched or welded mesh) and SmoothTex flat wire, will
also aid fish removal and limit descaling during transfer to the return system.
EPA is aware that some traveling screens utilize flat-panel wedgewire as the screen
material, as opposed to woven wire mesh or other materials. This configuration is
uncommon, however, and EPA did not examine this technology in detail nor study its
performance.
Through-screen Area and Mesh Size
As noted above, many existing conventional screening systems were initially designed to
remove debris from the intake stream to prevent damage to other equipment. The optimal
mesh size prevents entrainment of any debris large enough to clog the condenser tubes
while maximizing the through-screen area, and allows the facility to optimize its intake
velocity-to-screen area ratio and install a properly sized system. Because many condenser
tubes used in power plants are 3/4 or 7/8 inches in diameter, a 3/8-inch mesh size
(i.e., coarse mesh) is found at a majority of facilities employing traveling screens.
The percentage of the screen mesh that is open (aka percent open area) is a function of
both the size of the mesh openings and the area taken up by the mesh material. The mesh
percent open area and the total screen size are key factors in determining the CWIS's
intake velocity, which, in turn, influences the impingement mortality rate. Maintaining an
100 EPA's cost methodology for the existing facilities rule included full replacement costs for all screen
components.
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intake velocity as low as possible is critical to reducing the overall probability of
impingement. See Section 6.6.2 for more details.
Retrofitting existing traveling screens to operate with a fish collection system may
decrease the total through-screen area by blocking a portion of the screen face with fish
bucket or rail. Any impact on intake velocities, however, will depend on the original
screen design and the modifications made to incorporate new equipment. Advances in
screen design, materials, and fabrication methods enable newer screen systems that have
been designed with the fish protection measures to achieve comparable, and sometimes
greater, through-screen areas than older equipment that is retrofitted. In some cases, it
may be more advantageous to replace the entire screen assembly rather than retrofit the
existing traveling screen (Gathright 2008).
Collection Buckets
One of the more critical elements, collection buckets incorporate several design elements
to maximize safe capture of impinged fish. Buckets should extend across the screen
panel's full length to prevent gaps where fish may fall through and be deep enough to
hold sufficient water for the expected number and size of species impinged. Depending
on screen's size and rotation interval, captured fish may held in these buckets for several
minutes, often with other fish. Close proximity with other fish in a confined space,
particularly with those of another species, may create stress and behaviors that result in
additional injury. The selected bucket size and depth should reflect the target species and
allow for sufficient space and water coverage to sustain them during transfer to the return
system.
The design of pre-Fletcher collection buckets were found to cause significant turbulence
within the buckets, leading to high mortality rates as fish were buffeted against the screen
elements. The modifications described by Fletcher to minimize flow-induced turbulence
in the collection bucket have become common practice for this system type. The bucket's
shape was redesigned to include an additional lip or flow spoiler attached to the bucket's
leading edge. Further, modifications to prevent fish from escaping the rising bucket as it
nears the surface may also be necessary. A rail or guard that extends above the water
surface before the rest of the bucket keeps capture fish in the bucket and prevents their re-
impingement (Exhibit 6-13).
6.2.2.2 Removal and Return System Design Elements
The removal and return portion of the modified system comprises all elements that aid in
the removal offish from the screens and buckets and returns them to a safe location in the
source waterbody.
Debris and Fish Removal
Traveling screen systems without specific measures to reduce impacts to aquatic
organisms will collect impinged fish and debris without making a distinction between the
two. One of the major advances associated with the Ristroph design is the inclusion of a
separate fish removal system and return trough that sought to segregate aquatic species
from other debris. Unavoidably, some debris will end up with fish return trough and, vice
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 6: Technologies and Control Measures
versa; the key is designing the system to separate the two as much as possible. Separate
spray removal systems—a low pressure spray for removing fish and a high pressure spray
for debris—are typically included as part of a two-stage removal process that sorts most
fish and debris to their own dedicated troughs.
Using a low pressure spray (less than 20 pounds per square inch) is based on the
assumption that fish will not become attached or entangled with the screen panels and
thus require only a "gentle removal" from the screens and buckets. Removal in this
manner is also aided by smooth materials and structural components that eliminate
protrusions, sharp angles and rough surfaces that prevent fish release. Depending on the
spray head's position relative to the screen panel, it may be advantageous to remove
debris before fish. Heavy debris loads might clog screen panels and block the low-
pressure spray from functioning properly if the spray head is located behind the screen, as
described in the Indian Point analysis (Fletcher 1990). In this instance, a high pressure
spray (60 to 80 psi) placed ahead of the low pressure spray forcibly removes debris that
has become attached to the screen panels and may increase fish removal efficiency. When
low pressure spray heads are placed lateral to the screen instead of behind, it may be
more effective to remove debris after any impinged fish. As noted above, deciding the
order of low and high pressure spray must be carefully considered to optimize fish
protection.
Fish Return
Mortality-inducing injuries are more likely to occur during the collection and removal
portion of a modified traveling screen system. The return system, however, plays an
important role in the overall effectiveness and has many critical design elements that
must be considered to ensure safe return of healthy fish. Most criteria are universally
applicable to any modified traveling screen system, and include:
• Construction materials. Structural components should be constructed using
materials that minimize rough surfaces and protrusions that may cause abrasions,
contusions, descaling, or more serious physical injury during the return process.
Fiberglass-reinforced plastic, PVC, and stainless steel share this characteristic
while also being resistant to biofouling. Joints between pipe sections should also
be as smooth as possible.
• Size and capacity. As with the collection buckets themselves, the return trough
should be able to accommodate the largest species in the maximum estimated
number without overcrowding.
• Transport velocity. The water velocity in the return trough must be strong enough
to overcome the swimming capacity of the strongest species and ensure their
return to the water. A gravity return system will require a sufficient slope and
water volume to induce the necessary flushing action. Pump-aided returns can
adjust the return pressure accordingly.
• Flow disruptions. Where possible, the return should avoid sharp angles and short
bend radius turns to reduce flow disruption and redirection. At all points, care
should be taken to ensure a smooth, consistent return flow free from hydraulic
jumps and flow separation areas.
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• Exposure. Fish confined in a return trough have limited avenues of escape and,
depending on the length of the return, may have long transit times back to the
source waterbody. Because an open trough may unnecessarily expose these fish to
predation from birds or other animals, the preference in most cases is to enclose
the system entirely until fish are returned to the water. This has the added benefit
of reducing exposure to air temperature extremes. In cold weather climates, even
brief exposure to sub-freezing temperatures can increase mortality.
• Flushing cycle. Adequate flow must be maintained in the trough to clear all
transported fish from the return trough and drain completely following the cycle's
completion to prevent backflow and biofouling/deoxygenation. A consistent flow
may also be maintained in lieu of draining the trough.101
• Return Location. The final return point in the waterbody must be located outside
of the intake's radius of influence to prevent reimpingement. The final transition
to the waterbody (i.e., the point of discharge from the return system) should be
smooth and free of any significant hydraulic jump or located at a reasonable
height.102 Water quality and temperature should be comparable to conditions at
the intake to prevent any contact shock upon return. Preferably, organisms are
returned to the water quickly (i.e., to a nearby location) as longer exposure to the
return system may cause descaling or other injuries. An ideal location will also
avoid areas where predators congregate or attract increased predation.
Fish return systems may occasionally employ a fish pump, which transports organisms
from one area of the intake structure (e.g., a well that impinged fish are washed into) to a
discharge location. See DCN 10-6500 for an example. Fish pumps are not common, but
may be used when return distances are long or can't rely on gravity. Due to the
uncommon usage, EPA did not examine this technology in detail nor study its
performance.
EPRI has conducted at least two studies on the survival of organisms within a fish return
system. In a report published in 2010, EPRI studied the survival of organisms based on
organism size, return flume velocity, drop height, and the length of the fish return. Except
for early larval stages offish, most tests showed very high survival regardless of the
variable tested. In a recent technical update (see DCN 12-6801), EPRI's laboratory-based
research suggested that survival for hardy species is usually exceedingly high within the
return system and that the presence of debris in the return does not appear to have any
effect on survival for these hardy species.
101 Facilities usually withdraw screenwash water from within the intake structure (i.e., after it has passed
through the intake screens) or from a separate pump in the area of the intake structure. In either case, EPA
envisions that any increase in flow to accommodate improved flushing of the return system would be small
compared to the cooling water flow but nonetheless should generally not be included in calculating a
facility's cooling water withdrawals (for calculating DIP or the percent of water withdrawn for cooling
purposes).
102 EPRI's "Evaluation of Factors Affecting Juvenile and Larval Fish Survival in Fish Return Systems at
Cooling Water Intakes" (December 2010, Report No. 1021372) found that fish survival for a return system
that discharged below the water's surface was virtually the same as survival of fish dropped from a height
of up to 6 feet. See DCN 12-6822.
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6.2.2.3 Operation and Maintenance
Routine maintenance and operating protocols enacted for each modified traveling screen
installation also play a key role in determining the system's overall effectiveness. While
some parameters are widely applicable (e.g., rotation interval), others are tailored to meet
the specific needs at a particular location and may vary significantly from one facility to
another. These parameters include:
• Rotation interval. Evaluations at many different facilities over the last 30 years
have generally shown that impingement mortality rates are lowest when traveling
screens are rotated continuously at a fixed speed instead of the intermittent
rotation schedule more common with conventional traveling screens. Continuous
rotation ensures that any impinged fish will be caught on the screens for a
minimum time period, but in some cases may not be necessary, at least for all
seasons. Periodic full rotation cycles may be sufficient (i.e., some number of
complete rotations per hour) when impingement is dramatically lower or non-
existent during certain times of the year (e.g., seasonal migrations may limit the
critical time period to a few weeks or months of the year). Additionally, new
designs use composite materials to frame the traveling screens which weigh less
and reduce wear on chains and drives.
• Rotation speed. The longer a fish is impinged against a screen, the higher its
probability for suffering significant injury. Continuously rotated screens should
travel fast enough to minimize the impingement durations but be slow enough to
prevent higher maintenance costs associated with a faster screen rotation. The
rotation speed should also minimize the amount of time the fish are out of the
water.
• Preventative maintenance. Modified screens that are rotated continuously will
incur higher operating and maintenance costs than a conventional traveling screen
that is cycled intermittently. Mechanical equipment may require more robust
components to accommodate the increased rotation frequency and higher rotation
speeds necessary to minimize the impingement duration. Likewise, the screen
panels may require more intensive maintenance that minimizes corrosion and
biofouling, which may increase mortality rates by creating a rougher or more
unforgiving contact surface.
Retrofit/Downtime issues
Modified traveling screens with fish handling systems are among the oldest technologies
developed specifically to address impingement and have been widely deployed and
studied throughout the United States. Because so many existing facilities already use
conventional traveling screens, modified traveling screens are broadly applicable and
may not require significant changes to the CWIS to achieve high levels of performance.
A successful installation is generally independent of factors such as waterbody type,
climate zone, age, fuel type, or intake flow. In other words, a facility that has previously
used a conventional traveling screen (nearly all facilities, operating under a wide variety
of conditions) should also be able to employ a modified traveling screen.
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Compared with other impingement design and construction technologies used as retrofit
options, modified traveling screens are relatively easy to install and operate. Changes to
the screens themselves are relatively straightforward and, in all but the most unique
instances, do not require substantial modification or expansion of the screen houses and
can be completed during normal maintenance outages without affecting the facility's
generating schedule. Likewise, because this technology does not alter the cooling water
Row per se, the facility's generating output is unaffected; no energy penalty is incurred
save for the small increase in electrical usage due to continual or more frequent screen
rotation.
6.2.2.4 Technology Performance
Conventional traveling screens that have been modified to include a fish collection and
return system based on Ristroph and Fletcher designs have an extensive record of
performance at numerous facilities. Data shows impingement survival values greater than
90 percent for many species. However, the actual performance of modified traveling
screens is typically less than 90 percent when holding times are considered; in most
cases, the longer an organism is held under observation after impingement, the less likely
it is to survive. Additionally, larval impingement on fine mesh screens must also be
addressed when reviewing technology performance. See Chapter 11 of the TDD and the
preamble to the final rule for more information about how EPA assessed these data.
EPA also found that in many cases, only a few species comprise a large percentage of the
impinged organisms. For example, at the Arthur Kill Station, Atlantic herring, blueback
herring and bay anchovy composed over 90 percent of the impinged species during the
course of the study as described below. In addition, some of the impinged species may
not be typically considered highly valued commercial or recreational species or listed
species. Examples include gizzard shad and bay anchovy as commonly impinged
organisms reflected in study data. See TDD Chapter 11 for discussion of fragile species
and naturally moribund species.
6.2.2.5 Facility Examples
Salem Generating Station
Salem Generating Station, on the Delaware Bay estuary in New Jersey, converted 6 of its
12 conventional traveling screen assemblies to a modified design that incorporated
improved fish buckets constructed of a lighter composite material (which improved
screen rotation efficiency), smooth-woven mesh material, an improved spray wash
system (both low and high pressure), and flap seals to improve the delivery of impinged
fish from the fish buckets to the fish return trough (EPRI 2007). The initial study period
consisted of 19 separate collection events during mid-summer 1996. The configuration of
the facility at the time of the study (half of the screens had been modified) allowed for a
direct comparison of the effectiveness of the modified and unmodified screens on
impingement mortality rates. The limited sampling timeframe enabled the analysis of
only the species present in numbers sufficient to support any statistical conclusions. 1,082
juvenile weakfish were collected from the unmodified screens while 1,559 were collected
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from the modified structure. Analysts held each sample group separately for 48 hours to
assess overall mortality due to impingement on the screens. Results showed that use of
the modified screens had increased overall survival by as much as 20 percent over the use
of the unmodified screens. Approximately 58 percent of the weakfish impinged on the
unmodified screens survived, whereas the new screens had a survival rate approaching 80
percent. Both rates were based on 48-hour survival and not adjusted for the mortality of
control samples.
Water temperature and fish length are two independent factors cited in the study as
affecting overall survival. Researchers noted that survival rates decreased somewhat as
the water temperature increased, possibly as a result of lower levels of dissolved oxygen.
Survival rates decreased to a low of 56 percent for the modified screens when the water
temperature reached its maximum of 80°F. At the same temperature, the survival rate on
the unmodified screens was 35 percent. Differences in survival rates were also
attributable to the size of the fish impinged. In general, small fish (less than 50 mm) fared
better on both the modified and unmodified screens than large fish (greater than 50 mm).
The survival rates of the two size categories did not differ significantly for the modified
screens (85 percent survival for small, 82 percent for large), although a more pronounced
difference was evident on the unmodified screens (74 percent survival for small, 58
percent for large).
Salem Generating Station conducted a second series of impingement sampling from 1997
to 1998. By that time, all screen assemblies had been modified to include Ristroph/post-
Fletcher fish buckets and a fish return system. Additional modifications to the system
sought to enhance the chances of survival offish impinged against the screens. One
modification altered the fish return slide to reduce the stress on fish being delivered to the
collection pool. Flap seals were improved to better seal gaps between the fish return and
debris trough, thus preventing debris from affecting returning fish. Researchers used a
smaller mesh screen in the collection pools during the 1997-1998 sampling events than
had been used during the 1995 studies. The study notes that the larger mesh used in 1995
might have enabled smaller fish to escape the collection pool. Since smaller fish typically
have a higher mortality rate due to physical stress than larger fish, the actual mortality
rates may have been greater than those found in the 1995 study. The second impingement
survival study analyzed samples collected from October through December 1997 and
April through September 1998. Samples were collected twice per week and analyzed for
survival at 24- and 48-hour intervals. Six principal species were identified as constituting
the majority of the impinged fish during the sampling periods: weakfish, white perch, bay
anchovy, Atlantic croaker, spot, andAlosa spp. Fish were sorted by species and size,
classified by their condition, and placed in holding tanks. For most species, survival rates
varied noticeably depending on the season. For white perch, survival was above 90
percent throughout the sample period (as high as 98 percent in December). Survival rates
for weakfish varied from a low of 18 percent in July to a high of 88 percent in September.
Although the number of weakfish collected in September was approximately one-fifth of
the number collected in July, a possible explanation for the variation in survival rates is
the modifications to the collection system described above, which were implemented
during the study period. Similarly, bay anchovy fared worst during the warmer months,
dropping to a 20 percent survival rate in July while achieving a 72 percent rate during
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November. Rates for Atlantic croaker varied from 58 percent in April to 98 percent in
November. Spot were collected in only one month (November) and had a survival rate of
93 percent. The survival rate for theAlosa spp. (alewife, blueback herring, and American
shad) remained relatively consistent, ranging from 82 percent in April to 78 percent in
November. For all species in the study, with the exception of weakfish, survival rates
improved markedly with the use of the modified screen system when compared to data
from 1978-1982, when the unmodified system was still in use.
EPA conducted a site visit to Salem in January 2008. See DCN 10-6513.
Arthur Kill Station
The Arthur Kill Station is located on the Arthur Kill estuary in New York. To fulfill the
terms of a consent order, Consolidated Edison modified two of the station's dual-flow
intake screens to include smooth mesh panels, fish-retention buckets, flap seals to prevent
fish from falling between screen panels, a low-pressure spray wash system (10 psi), and a
separate fish return sluiceway (EPRI 2007). One of the modified screens had mesh of
1/8-inch by 1/2-inch while the other had 1/4-inch by 1/2-inch while the six unmodified
screens all had 1/8-inch by 1/8-inch mesh. Screens were continuously rotated at 20 ft/min
during the sampling events. The sampling period lasted from September 1991 to
September 1992. Weekly samples were collected simultaneously from all screens, with
the exception of 2 weeks when the facility was shut down. Each screen sample was held
separately in a collection tank where initial mortality was observed. A 24-hour survival
rate was calculated based on the percentage offish alive after 24 hours versus the total
number collected. Because a control study was not performed, final survival rates have
not been adjusted for any water quality or collection factors. The study did not evaluate
latent survival beyond the 24-hour period. Atlantic herring, blueback herring and bay
anchovy typically composed the majority (greater than 90 percent) of impinged species
during the course of the study period. Bay anchovy alone accounted for more than 72
percent of the sample population. Overall performance numbers for the modified screens
are greatly influenced by the survival rates for these three species. In general, the
unmodified screens demonstrated a substantially lower impingement survival rate when
compared to the modified screens. The average 24-hour survival for fish impinged on the
unmodified screens was 15 percent. Fish impinged on the larger mesh (1/4") and smaller
mesh (1/8") modified screens had survival average 24-hour survival rates of 92 percent
and 79 percent, respectively. Most species with low survival rates on the unmodified
screens showed a marked improvement on the modified screens. Bay anchovy showed a
24-hour survival rate increase from 1 percent on the unmodified screens to 50 percent on
the modified screens. The study period at the Arthur Kill station offered a unique
opportunity to conduct a side-by-side evaluation of modified and unmodified intake
structures. The results for 24-hour post-impingement survival clearly show a marked
improvement for all species that had fared poorly on the conventional screens. The study
notes that lower survival rates for fragile species such as Atlantic herring might have
been adversely affected by the collection tanks and protocols. Larger holding tanks
appeared to improve the survival of these species, suggesting that the reported survival
rates may under-represent the rate that would be achieved under normal (unobserved)
conditions, though by how much is unclear.
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Dunkirk Steam Station
Dunkirk Steam Station is located on the southern shore of Lake Erie in New York. In
1998 a modified dual-flow traveling screen system was installed on Unit 1 for an
impingement mortality reduction study (EPRI 2007). The new system incorporated an
improved fish bucket design to minimize turbulence caused by flow through the screen
face, as well as a nose cone on the upstream wall of the screen assembly. The nose cone
was installed to reduce the flow and velocity variations that had been observed across the
screen face. Samples were collected during the winter months of 1998/1999 and
evaluated for 24-hour survival. Four species (emerald shiner, juvenile gizzard shad,
rainbow smelt, and spottail shiner) compose nearly 95 percent of the sample population
during this period. All species exhibited high 24-hour survival rates; rainbow smelt fared
worst at 83 percent. The other three species had survival rates of better than 94 percent.
Other species were collected during the sampling period but were not present in numbers
significant enough to warrant a statistical analysis. The results presented above represent
one season of impingement sampling. Species not in abundance during cooler months
might be affected differently by the intake structure. Sampling continued beyond the
winter months, but data has not yet been reviewed by EPA.
Huntley Steam Station
Huntley Steam Station is located on the Niagara River in New York. The facility replaced
four older conventional traveling screens with modified Ristroph screens on Units 67 and
68 (EPRI 2007). The modified screens are fitted with smoothly woven coarse mesh
panels on a rotating belt. A fish collection basket is attached to the screen face of each
screen panel. Bucket contents are removed by low-pressure spray nozzles into a fish
return trough. High-pressure sprays remove remaining fish and debris into a separate
debris trough. The study does not contain the rotation interval of the screen or the screen
speed at the time of the study. Samples were collected over five nights in January 1999
from the modified-screen fish return troughs. All collected fish were sorted according to
initial mortality. Four targeted species (rainbow smelt, emerald shiner, gizzard shad, and
alewife) were sorted according to species and size and held to evaluate 24-hour survival
rates. Together, the target species accounted for less than 50 percent of all fish impinged
on the screens. (An additional 6,364 fish were not held for latent survival evaluation.) Of
the target species, rainbow smelt and emerald shiners composed the greatest percentage
with 57 and 37 percent, respectively. Overall, the 24-hour survival rate for rainbow smelt
was 84 percent; some variation was evident for juveniles (74 percent) and adults (94
percent). Emerald shiner were present in the same general life stage and had a 24-hour
survival rate of 98 percent. Gizzard shad, both juvenile and adult, fared poorly, with an
overall survival of 5 percent for juveniles and 0 percent for adults. Alewife were not
present in large numbers (n = 30) and had an overall survival rate of 0 percent. The study
notes the low survival rates for alewife and gizzard shad and posits the low water
temperature as the principal factor. At the Huntley facility, both species are near the
northern extreme of their natural ranges and are more susceptible to stresses associated
with extremes in water conditions. The water temperatures at the time of collection were
among the coldest of the year. Laboratory evaluations conducted on these species at the
same temperatures showed high degrees of impairment that would likely adversely affect
post-impingement survival. A control evaluation was performed to determine whether
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mortality rates from the screens would need to be adjusted for waterbody or collection
and handling factors. No discrepancies were observed, and therefore no corrections were
made to the final results. Also of note in the study is the inclusion of a spray wash
collection efficiency evaluation. The spray wash and fish return system were evaluated to
determine the proportion of impinged fish that were removed from the buckets and
deposited in the fish trough instead of the debris trough. All species had suitable removal
efficiencies.
6.2.3 Geiger screens
Geiger screens are a relatively new type of traveling screen made up of a series of curved
screen panels that rotate along the face of the intake screen along an oval path, much like
a luggage carousel at an airport (see Exhibit 6-14). This configuration serves to virtually
eliminate debris carryover. Geiger screens may be coarse mesh or fine mesh. The
standard design is to use stainless steel for the construction, using different grades for
freshwater and saltwater. As a result, capital costs for multi-disc screens may be higher
for freshwater systems than conventional screens but comparable for saltwater systems.
Standard screens have two drive chains and difficulty in maintaining equal tensioning on
both often results in sprocket failure. O&M costs should be lower for multi-disc screens,
as they only have one drive chain. Elimination of debris carryover can save on condenser
cleaning O&M. In addition, because water passes through the screens only once, head
loss across the screen is lower as compared to other types of screens.
The sickle-shaped screen panels can be fitted with different types of screen materials
such as drilled plastic, nylon or metal screen mesh. One manufacturer has designed a fine
mesh screen material that provides added strength for fine mesh by weaving in larger
wire stands - about one every inch - among the finer strands to give strength while
helping maintain a lower percent open area that using finer strands provides. Other
manufacturers use screen backings instead.
EPA is aware of two facilities in the U.S. that have installed Geiger screens, but has
found that the use of Geiger screens is more widespread in Europe. European Geiger
screens often use screen mesh sizes in the 1 mm to 3 mm range, with some as low as
0.5 mm and very few exceeding 4 mm. Many are installed on large industrial rivers like
the Rhine, which should have similar sediment and debris characteristics as large U.S.
rivers. European intake designs, however, are somewhat different from U.S. designs in
that they often use center-flow type screens and may have a three step screening
process.
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Exhibit 6-14. Geiger screen (image from EPRI 2007)
6.2.3.1 Technology Performance
Due to the relatively recent deployment of this technology, little performance data is
available. Preliminary results from the Mirant Potomac Generating Station have shown
impingement survival ranging from 0-100 percent depending on species. The most
numerous species included bluegill, channel catfish, spottail shiner, and white perch.
Representatives from EPRI and Mirant noted during the site visit at Potomac Generating
Station that testing of a fine mesh Geiger screen was underway. EPRI also completed a
laboratory study of the Multi-Disc screen in February 2013.
6.2.3.2 Facility/Laboratory Examples
Mirant Potomac Generating Station
Mirant Potomac is located on the Potomac River in Virginia. The facility previously used
single-entry, single-exit traveling screens and installed Geiger screens on each of its
cooling water intake structures in 2004 to reduce the debris carryover experienced by
some of the vertical traveling screens. The new screens (mesh size of 3/8") have virtually
eliminated debris clogging in the condenser. However, due to high suspended sediment
loads in the source water, the facility still regularly shuts down to remove sediment
buildup in the condenser tubes. The Geiger screen for Unit 1 is also equipped with fish
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buckets, a low pressure spray wash, and the ability to add a fish return trough. Data
generated in 2005 and 2006 showed mixed results. Bluegill impingement survival ranged
from 95-100 percent; channel catfish ranged from 50-94 percent; spottail shiner ranged
from 54-95 percent; and white perch ranged from 30-56 percent. The facility noted that
major runoff events may have compromised some of the sampling and that additional
data would need to be collected. (See DCN 10-6814.)
EPA conducted a site visit to Potomac in December 2007. See DCN 10-6512. The facility
closed permanently on October 1, 2012.
Donald C. Cook Nuclear Power Plant
Donald C. Cook Nuclear Power Plant is located in Michigan on Lake Michigan. From
October 1, 2003 through the first week of January 2004, the facility conducted a pilot
test of the Geiger Multidisc screens, using a drilled polyethylene disk, to minimize
debris carryover. (See DCN 10-6811.) The plant tested the screens in two of 14 screens.
The screens functioned well and were able to be maintained at the deck level as
opposed to being transported off-site. Installation required about one week per screen
and the retrofit could be completed without downtime. No fish protection data was
available.
6.2.4 Hydrolox screens
The Hydrolox screen is a hinged vertical traveling screen made of an engineered polymer
and consists of interconnected modules assembled in a bricklayed pattern for strength.
(See Figure 6-15.) The Hydrolox screen has a smooth polymer surface and minimizes
impingement mortality through the use offish scoops," similar to fish buckets used in
Ristroph screens. Debris carryover is reduced by using "flights" which may be
interchanged with the fish scoops. Screen slot sizes are about Vi" or 6-7 mm. The
Hydrolox screen fits into existing areas made for traditional vertical traveling screens.
The modular components allow maintenance to be performed on-site without having to
replace the entire screen. The engineered polymer is light, non-corrosive, and minimizes
biofouling. This is a relatively new technology that underwent laboratory testing by
Alden Laboratories in December of 2006 and full scale testing at Barrett Station, NY in
2007-2008.
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Chapter 6: Technologies and Control Measures
Exhibit 6-15. Hydrolox screen (image from DCN 10-6831)
6.2.4.1 Technology Performance
Results of laboratory testing conducted in 2006 show over 90 percent impingement
survival of golden shiner, common carp, bluegill, and channel catfish. (See DCN 10-6807.)
6.2.4.2 Facility Examples
Alden Laboratories Flume Testing
Alden Laboratories conducted impingement tests using a Hydrolox screen from July-
August 2006. Flume tests were conducted using a 4 ft wide by 12 ft high Hydrolox screen
installed perpendicular to the flow. The screening material was made of molded plastic
with slot openings of 0.25 in. by 0.30 in. Five freshwater species were used in the
experiment including the following: golden shiner, common carp, bluegill, striped bass,
and channel catfish. The screen was rotated at either 5 ft/min or 10 ft/min with water flow
velocities of 1 fps or 2 fps. Mortality rates were less than 10 percent for four of five
species (golden shiner, common carp, bluegill, and channel catfish), and injury and scale
loss were under 5 percent. Striped bass results seemed to be impacted by handling issues
as mortality rates for both the test group and the control group were higher but did not
seem to be caused by the Hydrolox screen (Alden 2006).
6.2.5 Beaudrey W Intake Protection (WIP) Screen
The Beaudrey W Intake Protection (WIP) screen is a screen wheel that faces the
incoming flow, screening both debris and organisms into a backwash pump that
transports debris and organisms back to the source water. (See Exhibit 6-16.) The WIP
screen is installed in front of the recirculating water pumps and is easily retrofitted into
existing traveling screen openings and guides. All components are mounted either on the
deck plate or the WIP module itself. The WIP module can easily be raised for
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§ 316(b) Existing Facilities Final Rule - TDD
maintenance or inspection without disassembling the screen (see DCN 10-6810 and
10-6606). This reduces costs and no downtime is necessary.
Exhibit 6-16. WIP screen (image from Beaudrey)
103
Beaudrey's Fish Protection System (FPS) works as part of the WIP and includes a
Hidrostal® fish pump and backwash screens. The FPS also works with fine mesh screens
and can be installed at the same time as the screens or added/retrofitted later. Fish are
impinged for a maximum of 30 seconds, as the FPS operates at two revolutions per
minute. With the FPS/WIP screen combination (rotating screening wheel with no chains
103
See DCN 10-6810A.
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or sprocket teeth), there is no carry-over of debris or fish. The system works well for
high, low, and mid-range water levels. The FPS/WIP screen is being tested at one site in
the US, but is not in widespread use. The FPS system can be used in conjunction with
other types of screens such as drum screens and traveling screens. There are multiple
installations of the FPS system in Europe.
6.2.5.1 Technology Performance
System operational tests of the Beaudrey FPSiM have shown strong capabilities to reduce
impingement mortality; tests have demonstrated mean survival rates in excess of 90
percent across a range offish species (see DCN 10-6810 and 10-6606). Preliminary
impingement survival sampling results from May 2008, for bluegill, fathead minnow, and
channel catfish ranged from 79.3 percent to 99.0 percent. A holding time of 48 hours was
used for the study.
6.2.5.2 Facility/Laboratory Examples
Omaha Public Power District - North Omaha Power Station, Nebraska
The North Omaha Power Station is located in North Omaha, Nebraska. The facility
completed a two-year pilot study (in coordination with EPRI) of the WTP/FPS screen in
2008 to study impingement mortality. Initial efforts were abandoned as researchers
discovered that the number offish normally impinged at the facility was too low to
provide meaningful data. The study then shifted to introduce fish directly in front of the
screen and study the subsequent impingement event. Hatchery fish representative of the
species found in the Missouri River were used, as well as "wild" fish caught in a seine net
near the facility. The study results showed impingement survival rates of 79 percent to
over 90 percent, with no statistically significant difference between fish exposed to the
screen versus the control group that was not exposed to any screens.
EPA conducted a site visit to North Omaha in March 2009. See DCN 10-6521.
Alden Laboratories Flume Testing
Alden Laboratories conducted impingement tests using a fine mesh Beaudrey WIP screen
in 2011. The testing was intended to explore mesh size, approach velocity and spray wash
pressure on the impingement survival of several species offish. Survival ranged from 4.7
percent to 86 percent when intake velocity was varied. See DCN 12-6800.
6.2.6 Coarse Mesh Cylindrical Wedge wire
Cylindrical wedgewire screens, also called "V" screens or profile screens, unlike
traveling screens, are a passive intake system. Their performance is largely dictated by
conditions that are independent of the source waterbody's biological composition. 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. When appropriate conditions are met, these screens exploit physical
and hydraulic exclusion mechanisms to achieve consistently high reductions in
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impingement (and as a result, impingement mortality). Significant entrainment reductions
may also be observed when the screen slot size is small enough to exclude egg and larval
life stages (see below for a discussion of fine mesh wedgewire screens). Of the 766
existing facility intakes that were reported in the detailed questionnaires, 60 intakes used
wedgewire screens.
Slot sizes for conventional traveling screens typically refer to a square opening (3/8" x
3/8") that is punched or woven into the screen face.104 Wedgewire screens are
constructed differently, however, with the slot size referring to the maximum distance
between longitudinally adjacent wires. These screens are designed to have a low, uniform
through-slot velocity (less than 0.5 feet per second) and typically have smaller slot sizes
than a coarse mesh traveling screen. The intake velocity quickly dissipates away from the
screen due to the cylindrical shape, thus creating a relatively small flow field in the
waterbody. This small flow field, together with optimal screen orientation, results in a
small system profile and minimizes the potential for contact between the screen and any
susceptible organisms that may come under the intake's hydraulic influence. In addition,
the ambient current crossflow (i.e., to maximize the sweeping velocity provided by the
waterbody) carries most free-floating organisms and debris past the screen, removing
organisms that are temporarily in contact with or pinned against the screen.105 As such,
screen orientation is also an important component of this technology's overall
performance. The low through-slot velocity in combination with the screen orientation
and cross current flow carries organisms away from the screen allowing them to avoid or
escape the intake current. Wedgewire screens may also employ cleaning and de-icing
systems, such as air-burst sparging or may be constructed with nickel or copper alloys to
discourage biofouling.
EPA believes that cylindrical wedgewire screens can be successfully employed by large
intake facilities under certain circumstances. Although many of the current installations
of this technology have been at smaller-capacity facilities, large water withdrawals can be
accommodated by multiple screen assemblies in the source waterbody. The limiting
factor for a larger facility may be the availability of sufficient accessible space near the
facility itself because additional screen assemblies consume more space on the waterbody
floor and might interfere with navigation or other uses of the waterbody. Consideration of
the impacts in terms of space and placement must be evaluated before selecting
wedgewire screens for deployment.
As with any intake structure, the presence of large debris poses a risk of damage to the
structure if not properly managed. Cylindrical wedgewire screens, because of their need
to be submerged in the water current away from shore, might be more susceptible to
debris interaction than other onshore technologies. Vendor engineers and facility
representatives indicated that large debris has been a concern at several of their existing
installations, but the risk associated with it has been effectively minimized by selecting
the optimal site and constructing debris diversion structures. Significant damage to a
104 See DCN 10-6604 for additional discussion on wedgewire slot sizes.
105 Preliminary hydrodynamic studies suggest that at a through-slot velocity of 0.5 fps, the sweeping flow is
dominant over the intake flow and when intakes are properly oriented with each other can even reduce the
number of organisms entrained.
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wedgewire screen is most likely to occur from fast-moving submerged debris. Because
wedgewire screens do not need to be sited in the area with the fastest current, a less
damage-prone area closer to shore or in a cove or constructed embayment can be
selected, provided it maintains a minimum ambient current around the screen assembly.
If placement in the main channel is unavoidable, deflecting structures can be employed to
prevent free-floating debris from contacting the screen assembly. Typical installations of
cylindrical wedgewire place them roughly parallel to the direction of the current,
exposing only the upstream nose to direct impacts with debris traveling downstream.
EPA has noted several installations where debris-deflecting nose cones have been
installed to effectively eliminate the damage risk associated with most debris. Apart from
the damage that large debris can cause, smaller debris, such as household trash or organic
matter, can build up on the screen surface, altering the through-slot velocity of the screen
face and increasing the risk of entrainment and/or impingement of target organisms.
Again, selection of the optimal location in the waterbody might be able to reduce the
collection of debris on the structure. Ideally, cylindrical wedgewire is located away from
areas with high levels of submerged aquatic vegetation (SAV) and out of known debris
channels. Proper placement alone may achieve the desired effect, although technological
solutions also exist to physically remove small debris and silt. Automated air-burst
systems can be built into the screen assembly and set to deliver a short burst of air from
inside and below the structure. Debris is removed from the screen face by the air burst
and carried downstream and away from the influence of the intake structure.
Improvements to the air burst system have eliminated the timed cleaning cycle and
replaced it with one tied to a pressure differential monitoring system.
Wedgewire screens are more likely to be placed closer to navigation channels than other
onshore technologies, thereby increasing the possibility of damage to the structure itself
or to a passing commercial ship or recreational boat. Because cylindrical wedgewire
screens need to be submerged at all times during operation, they are typically installed
closer to the waterbody floor than the surface. In a waterbody of sufficient depth, direct
contact with recreational or commercial vessels is unlikely. EPA notes that other
submerged structures (e.g., pipes, transmission lines) are preset in many waterbodies and
are properly delineated with acceptable navigational markers to prevent accidents
associated with trawling, dropping anchor, and similar activities. Such precautions would
likely be taken for a submerged wedgewire screen as well.
6.2.6.1 Technology Performance
Cylindrical wedgewire screens have not been used extensively as an impingement control
technology at facilities with large intake flows, but data describing their performance at
several installations, as well as laboratory evaluations, suggest a strong potential to
reduce impingement impacts when certain design and construction criteria are satisfied.
Data from some studies have shown reductions in impingement of near 100 percent.
Other factors also influence this technology's overall performance and must be
considered during the system's design phase. Some data suggest that orienting the
screens perpendicular to the ambient flow can minimize contact injuries by reducing
screen-organism contact times, but at the expense of increasing the screen's profile. A
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parallel orientation offers the smallest possible profile but may raise screen-organism
contact times as the organism has to travel the full length of the screen before returning to
the waterbody. The optimal orientation may be further influenced by the sensitivity and
abundance of the target species, as well as the probability for high debris loads in the
waterbody or the potential for frazil/sheet ice buildup.106
6.2.6.2 Facility/Laboratory Examples
JH Campbell
JH Campbell is located on Lake Michigan in Michigan, with the intake for Unit 3 located
approximately 1,000 meters from shore at a depth of 10.7 meters. The cylindrical intake
structure has 9.5 mm mesh wedgewire screens and withdraws approximately 400 mgd.
Raw impingement data are not available, and EPA is not aware of a comprehensive study
evaluating the impingement reduction associated with the wedgewire screen system.
Comparative analyses using the impingement rates at the two other intake structures
(onshore intakes with conventional traveling screens) have shown that impingement of
emerald shiner, gizzard shad, smelt, yellow perch, and alewife associated with the
wedgewire screen intake has been effectively reduced to insignificant levels.
Maintenance issues have not been shown to be problematic at JH Campbell because of
the far offshore location in deep water and the periodic manual cleaning using water jets
to reduce biofouling.
Eddystone Generating Station
Eddystone Generating Station is located on the tidal portion of the Delaware River in
Pennsylvania. Units 1 and 2 were retrofitted to include wide-mesh wedgewire screens
and currently withdraw approximately 500 mgd from the Delaware River. Pre-
deployment data showed that over 3 million fish were impinged on the unmodified intake
structures during a single 20-month period. An automatic air burst system has been
installed to prevent biofouling and debris clogging from affecting the performance of the
screens. EPA has not been able to obtain biological data for the Eddystone wedgewire
screens but EPRI (2007) indicates that fish impingement has been eliminated.
EPA conducted a site visit to Eddystone in January 2008. See DCN 10-6507. Unit 1 was
retired in 2011 and Unit 2 was retired in 2012.
6.2.7 Fine Mesh Screens
Both traveling screens and wedgewire screens can be designed to incorporate a fine
screen mesh to reduce entrainment.
106 In the 2004 Phase II rule, use of a wedgewire screen (under certain parameters) was deemed to be a pre-
approved technology for impingement requirements. This designation is no longer specifically included
under the existing facilities rule, as installation of a wedgewire screen presumably already meets the intake
velocity criteria at 40 CFR 125.94(c)(2).
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6.2.7.1 Fine Mesh Traveling Screens
Fine mesh screens (mesh size of 5 mm or less107) are typically mounted on conventional
traveling screen systems and are used to exclude eggs, larvae, and juvenile forms offish
from intakes.108 Successful use of fine mesh screens is contingent on the application of
satisfactory handling and return systems to allow the safe return of impinged organisms
to the aquatic environment. Of the 766 existing facility intakes that were reported in the
detailed questionnaires, 43 intakes reported using fine mesh screens with a mesh size of 5
mm or less.
A retrofit with fine mesh screens is more complicated than one with coarse mesh because
the total through screen area will be decreased as a result of smaller screen slot sizes
(assuming the same intake structure size). Because the intake volume remains unchanged,
through-screen velocity will increase, perhaps significantly, unless the total intake
structure area is also increased. The former is generally undesirable, as intake velocity is
an important criterion in reducing impingement. The latter could result in a longer
downtime period than for retrofitting to modified coarse mesh traveling screens. For
example, replacing coarse mesh screens with a 68 percent open area with fine mesh
screens of the same size with a 44 percent open area will increase the through-screen
velocity by a factor of 1.55. If the retrofit analysis estimated that the total screen area
required is greater than what is available at the existing intake (i.e., the compliance screen
area factor is greater than 1.0), a new intake with a larger screen area would be needed.
EPA assumed the new larger intake would have a through-screen velocity of 0.5 fps
when estimating the screen area factor and technology costs for a new larger intake.109
The size and cost of this new screen technology are directly related to the required screen
surface area.uo Velocity increases beyond a certain range would be unacceptable because
they might increase impingement of other organisms and would increase the mortality of
eggs and larvae captured on the fine mesh screen panels.
Fouling and clogging concerns may be more pronounced with fine mesh screens as well.
With a smaller screen open area, the effects of fouling on through-screen velocity (and
flow volume provided for cooling) may be affected.
As the desired mesh size decreases (i.e., as the screen compliance factor increases), the
potential for problems associated with the availability of space to construct a larger intake
increases. This is especially true for shore-based intake technologies, since water depth is
generally relatively shallow, thereby requiring any screen expansion to cover a
proportionally longer length of shoreline. The availability of additional shore space at
many existing intakes may be limited due to existing structures and other
107 There is no widely accepted definition of "fine mesh." EPA's industrial surveys in 2000 used 5mm as
the maximum spacing of fine mesh. Since that time, new data shows that fine mesh screens must be less
than 2 mm to have a significant effect on total entrainment.
108 Fine mesh screen overlays can also be used to attach to a coarse mesh screen.
109 At proposal, EPA used a design through-screen velocity of 1.0 fps for new expanded intakes. For the
final rule, this was changed to 0.5 fps; refer to Chapter 8 for more information.
110 See Chapter 8 of the TDD, which describes the costing model used for the final rule. Module 3 contains
the costs for expanding an existing intake structure.
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considerations.111 See DCN 10-6601 for further information on fine mesh screen
feasibility, particularly with respect to debris handling and screen expansion.
EPA analyzed several options for fine mesh screens (see Chapter 7 and the preamble to
the proposed rule) but ultimately did not adopt them as the technology basis. In its
analysis, EPA found that many model facilities would be required to significantly expand
their intake structures to accommodate the fine mesh screens and maintain a 0.5 fps
through-screen velocity; in some cases, as many as 68 percent of facilities would need to
expand the size of their intake by more than five times, leading EPA to believe that fine
mesh screens would not be an available technology at those sites.
6.2.7.1.1 Technology Performance
Fine mesh traveling screens designed to reduce entrainment impacts have been used at a
few large intake facilities, but data describing their performance is limited. Data
demonstrates that entrainment typically decreases as mesh size decreases, particularly for
eggs. In an August 2008 presentation to EPA, EPRI stated that field deployment of fine
mesh traveling screens with favorable screen operating performance (i.e., can properly
handle debris loading) included eight power plant sites in the US (Dixon 2008; DCN
10-6818).112 These facilities represent various waterbody types, flows, fuel types,
configurations, and locations throughout the country. The wide variety of operating
conditions at facilities with fine mesh traveling screens suggests that with proper design
and operation, these screens are technically feasible at most facilities.113
For the 2004 Phase II rule, EPA assumed that the mortality of entrained organisms would
be 100 percent114. However, as mesh sizes are reduced to prevent entrainment, more and
more entrainables become impinged on the screens (i.e., "converted" from entrainable to
impingeable) and subjected to spray washes and return along with larger impinged
organisms as well as debris from the screens. Under the 2004 Phase II rule, these
"converts" would be classified as a reduction in entrainment, since the entrainment
performance standard simply required a reduction in the number (or mass) of entrained
organisms entering the cooling system. However, for some facilities the low survival rate
of converts resulted in the facility have difficulty complying with the impingement
mortality standards. By comparison, the performance standard for impingement was
measured as impingement mortality. Organisms that were impinged (i.e., excluded) from
the cooling water intake structure were typically washed into a return system and sent
back to the source water. In this case, impingement mortality is an appropriate measure of
the biological performance of the technology.
111 Examples might include limited ownership of shoreline property or conflicting uses of the shoreline.
112 The facilities listed were Hanford Generating Project, Barney Davis, Indian Point, Big Bend,
Brunswick, Somerset, Dunkirk, and Prairie Island.
113 Further, the technology vendors stated that the distribution of fine mesh traveling screens has been
limited due to the fact that few facilities have been required to install fine mesh screens. EPRI also
concluded that the potential for future use of fine mesh screens is favorable, as handling procedures and
screen designs have continued to improve (Dixon 2008).
114 Fine mesh screens were considered to be one technology that could be used to meet the entrainment
performance standards under the 2004 Phase II rule
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Chapter 6: Technologies and Control Measures
Through EPA's review of control technologies, the Agency found that the survival of
"converts" on fine mesh screens was very poor, and in some extreme cases comparable to
the extremely low survival of entrained organisms that are allowed to pass entirely
through the facility.115 More specifically, 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. More tellingly, the mortality
of larvae collected from a fine mesh screen was usually greater than 80 percent. As a
result, a facility with entrainment exclusion technologies such as fine mesh screens could
approach 90 percent performance, but the subsequent survival of these organisms ranged
from 0 to 52 percent (mean value of 12 percent survival) depending on life stage and
species, and the facility's impingement mortality rates increased.
Exhibit 6-17 illustrates this concept. Organisms of all sizes are exposed to the screen
face. Larger organisms (i.e., those that would be impinged by any mesh size) are
impinged and sent to the fish return. "Converts" (i.e., those that would pass through a
coarse mesh screen) are also impinged and sent to the fish return.116 Small organisms and
eggs that would not be impinged by any mesh size pass through the screen and are
entrained.
Exhibit 6-17. Illustration of fine mesh screen operation and "converts'
Pumps
Through-plant entrainment survival has been studied extensively, with EPRFs Review of Entrainment
Survival Studies being amongst the most comprehensive. See DCN 2-017A-R7 from the Phase I docket.
116 Exhibit 6-17 also shows a screen applied to the fish return. Consistent with EPA's definition of
impingement in the final rule, this symbolizes that impingement standards would be applied to those fish
that would have been impinged by a 3/8" screen (i.e., a graphic representation of the "hypothetical net").
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So, a facility that simply excluded entrainable organisms (with no attention being paid to
whether they survive or not) could be deemed to have met its entrainment requirements
under the 2004 Phase II rule, when in fact it may be causing the same level of mortality
as a facility with no entrainment controls at all. EPA's current review of entrainment and
entrainment mortality shows the same trends identified in the research reviews by EPRI
(see DCNs 10-6802 and 6-5004B). For fine mesh traveling screens, impingement of
converts increases as mesh size is reduced, with survival of the converts being dependent
upon species and intake velocity. For fine mesh wedgewire screens, entrainment
decreases with increasing larval length, increased sweeping flow, decreasing slot (intake)
velocity, and decreasing slot width; minimal impingement of converts was observed.
A representative for Eimco (a traveling screen vendor) stated that 0.5 mm fine mesh
requires low screen velocities (i.e., approximately 0.5 fps) and that retrofitting a high
velocity traveling screen with 0.5 mm mesh would be very difficult on large rivers such
as the Mississippi and Missouri Rivers (Gathright 2008). The Missouri River is known
for having high levels of suspended sediment, which can create problems in "blinding" of
the intake screens. Blinding of the screens occurs when the sediment and debris
accumulate on the screens at a rapid rate. If increased screen rotation and backwashing is
not sufficient to remove the sediment, then the desired cooling pumping rate may not be
sustained, which would force the facility to reduce the pumping rate or cease
withdrawals, leading to a reduction (or cessation) of power generation. Typically, the
problem of screen blinding in rivers with high sediment loading diminishes as the screen
mesh size approaches 1.0 mm and does not present a problem if 2.0 mm screens are used
(Gathright 2008).
The primary reason for the difference in performance of screens with different mesh sizes
is due to the typical distribution of sand particle size in the river water. In a study of sand
grain size distribution from the Fraser River Port in British Columbia, 90 percent of the
sand particles were less than 0.5 mm in size, with the percent content increasing rapidly
below 0.5 mm (see DCN 10-6601). The particle size distribution graph shows that 0.5
mm was somewhat of an inflection point where grain size content diminished more
gradually as the size increased, approaching 0 percent at 2 mm. Thus, a screen with a
mesh size of 0.5 mm would capture a significant portion of the suspended material, while
a screen with a mesh size near 2.0 mm would capture very little of it.
Problems with larger, less-dense debris particles such as leaves will not be affected as
much by mesh size, since such debris particles will be captured on the screen regardless
of mesh size and, therefore, no changes in operation would be expected with finer mesh.
EPA recognizes that high sediment waterbodies pose a challenge for fine mesh screens.
However, a mesh size of 2.0 mm has been shown to be effective in handling the high
sediment loads. EPA also acknowledges that facilities located on high sediment rivers
face constant challenges related to sediment regardless of screen mesh size, as existing
intake screens may become clogged or suffer premature failure or condenser tubes may
require more frequent cleaning.
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6.2.7.1.2 Facility Examples
Big Bend
The most significant example of long-term use of fine-mesh screens has been at the Big
Bend Power Plant in the Tampa Bay area. The facility has an intake canal leading to a
shoreline intake with 0.5 mm mesh Ristroph screens that are used seasonally on the
intakes for Units 3 and 4. During the mid-1980s when the screens were initially installed,
their efficiency in reducing I&E mortality was highly variable (EPRI 2007). The
operator, Florida Power & Light (FPL) evaluated different approach velocities and screen
rotational speeds. In addition, FPL recognized that frequent maintenance (manual
cleaning) was necessary to avoid biofouling. By 1988, system performance had improved
greatly. The system's efficiency in screening fish eggs (primary species are drum and bay
anchovy) exceeded 95 percent,117 with 80 percent latent survival for drum and 93 percent
for bay anchovy. For larvae (primary species are drum, bay anchovy, blennies, and
gobies), screening efficiency was 86 percent,118 with 65 percent latent survival for drum
and 66 percent for bay anchovy. Note that latent survival in control samples was also
approximately 60 percent. Although more recent data are generally not available, the
screens continue to operate successfully at Big Bend in an estuarine environment with
proper maintenance.
EPA conducted a site visit to Big Bend in March 2008. See DCN 10-6502.
Other Facilities
Although egg and larvae entrainment performance data are not available, fine mesh
(0.5 mm) Passavant screens (single entry/double exit) have been used successfully in a
marine environment at the Barney Davis Station in Corpus Christi, Texas. Impingement
data for this facility show an overall 86 percent initial survival rate for bay anchovy,
menhaden, Atlantic croaker, killfish, spot, silverside, and shrimp. EPA conducted a site
visit to Barney Davis in March 2008. See DCN 10-6500.
Additional full-scale performance data for fine-mesh screens at large power stations are
generally not available. However, some data are available from limited use or study at
several sites and from laboratory and pilot-scale tests. Seasonal use of fine mesh on two
of four screens at the Brunswick Power Plant in North Carolina has shown 84 percent
reduction in entrainment compared to the conventional screen systems. Similar results
were obtained during pilot testing of 1 mm screens at the Chalk Point Generating Station
in Maryland.119 At the Kintigh Generating Station in New Jersey, pilot testing indicated
that 1 mm screens provided 2 to 35 times the reduction in entrainment over conventional
9.5 mm screens. Finally, Tennessee Valley Authority (TVA) pilot-scale studies
performed in the 1970s showed reductions in striped bass larvae entrainment of up to
99 percent for a 0.5 mm screen and 75 and 70 percent for 0.97 mm and 1.3 mm screens,
117 The 95 percent value reflects the exclusion rate, the percentage of organisms prevented from entering
the cooling water system and does not address entrainment mortality.
118
119
118 As above, this value is a an exclusion rate.
EPA conducted site visits to Brunswick and Chalk Point in January 2008 and December 2007,
respectively. See DCNs 10-6559 and 10-6504.
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respectively. A full-scale test by TVA at the John Sevier Plant showed less than half as
many larvae entrained with a 0.5 mm screen than with 1- and 2 mm screens combined.
Alden Laboratories Flume Testing
Alden Laboratories conducted impingement tests using a fine mesh traveling screen in
2011. The testing was intended to explore mesh size, approach velocity and spray wash
pressure on the impingement survival of several species offish. Survival ranged from 4.7
percent to 86 percent when intake velocity was varied. See DCN 12-6800.
6.2.7.2 Fine Mesh Wedgewire Screens
Fine mesh wedgewire functions in the same way as coarse mesh wedgewire, but due to
the reduced slot size also acts to exclude smaller organisms (including larvae and eggs),
reducing entrainment. Physical exclusion is accomplished by designing the screens with a
slot size that will prevent the entrainment of the smallest target taxa or life stage. In
general, a smaller slot size will translate into larger or more numerous screen assemblies
in order to maintain the desired through-slot velocity. Furthermore, small slots increase
the debris clogging potential and associated maintenance needs.
6.2.7.2.1 Technology Performance
Fine-mesh applications (those designed to target eggs and larvae) have shown high
potential to reduce entrainment if intake velocities are maintained. Reductions in
entrainment exclusion of approximately 90 percent have been demonstrated. Due to
difficulty in collecting entrainables from a fine mesh wedgewire screen, entrainment
survival is not known.
6.2.7.2.2 Facility Examples
Laboratory Evaluation
EPRI published (May 2003; see DCN 6-5004B) the results of a laboratory evaluation of
wedgewire screens under controlled conditions in the Alden Research Laboratory Fish
Testing Facility. A principal aim of the study was to identify the important factors that
influence the relative rates of impingement and entrainment associated with wedgewire
screens. The study evaluated characteristics such as slot size, through-slot velocity, and
the velocity of ambient currents that could best carry organisms and debris past the
screen. When each of the characteristics was optimized, wedgewire screen use became
increasingly effective as an impingement reduction technology; in certain circumstances
it could be used to reduce the entrainment of eggs and larvae. EPRI notes that large
reductions in impingement and entrainment might occur even when all characteristics are
not optimized. Localized conditions unique to a particular facility, which were not
represented in laboratory testing, might also enable successful deployment. The study
cautions that the available data are not sufficient to determine the biological and
engineering factors that would need to be optimized, and in what manner, for future
applications of wedgewire screens.
Slot sizes of 0.5, 1.0, and 2.0 mm were each evaluated at two different through-slot
velocities (0.15 and 0.30 m/s) and three different channel velocities (0.08, 0.15, and
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0.30 m/s, corresponding to 0.25, 0.5, and 1.0 fps) to determine the impingement and
entrainment rates offish eggs and larvae. Screen open area increased from 24.7 percent
for the 0.5 mm screens to 56.8 percent for 2.0 mm screens. The study evaluated eight
species (striped bass, winter flounder, yellow perch, rainbow smelt, common carp, white
sucker, alewife, and bluegill) because of their presence in a variety of waterbody types
and their history of entrainment and impingement at many facilities. Larvae were studied
for all species except alewife, while eggs were studied for striped bass, white sucker, and
alewife. (Surrogate, or artificial, eggs of a similar size and buoyancy substituted for live
striped bass eggs.) Individual tests followed a rigorous protocol to count and label all fish
eggs and larvae prior to their introduction into the testing facility. Approach and through-
screen velocities in the flume were verified, and the collection nets used to recapture
organisms that bypassed the structure or were entrained were cleaned and secured. Fish
and eggs were released at a point upstream of the wedgewire screen selected to deliver
the organisms at the centerline of the screens, which maximized the exposure of the eggs
and larvae to the influence of the screen. The number of entrained organisms was
estimated by counting all eggs and larvae captured on the entrainment collection net.
Impinged organisms were counted by way of a plexiglass window and video camera
setup.
In addition to the evaluations conducted with biological samples, Alden Laboratories
developed a Computational Fluid Dynamics (CFD) model to evaluate the hydrodynamic
characteristics associated with wedgewire screens. The CFD model analyzed the effects
of approach velocity and through-screen velocities on the velocity distributions around
the screen assemblies. Using the data gathered from the CFD evaluation, engineers were
able to approximate the "zone of influence" around the wedgewire screen assembly under
different flow conditions and estimate any influence on flow patterns exerted by multiple
screen assemblies located in close proximity to each other.
The results of both the biological evaluation and the CFD model evaluation support many
of the conclusions reached by other wedgewire screen studies, as well as in situ anecdotal
evidence. In general, the lower impingement rates were achieved with larger slot sizes
(1.0 to 2.0 mm), lower through-screen velocities, and higher channel velocities.
Similarly, the lowest entrainment rates were seen with low through-screen velocities and
higher channel velocities, although the lowest entrainment rates were achieved with
smaller slot sizes (0.5 mm). Overall impingement reductions reached as high as 100
percent under optimal conditions, and entrainment reductions approached 90 percent. It
should be noted that the highest reductions for impingement and entrainment were not
achieved under the same conditions. Results from the biological evaluation generally
agree with the predictions from the CFD model: the higher channel velocities, when
coupled with lower through-screen velocities, would result in the highest rate of
protection for the target organisms.
Other Facilities
Other facilities with lower intake flows have also installed wedgewire screens, but there
are limited biological performance data for these facilities. Unit 1 at the Cope Generating
Station in South Carolina is a closed-cycle unit that withdraws about 6 mgd through a
2 mm wedgewire screen; however, no biological data are available. Westchester RESCO
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(design flow of 55 mgd) uses a wedgewire screen with 2.0mm slot size; however, no
studies relating to reductions in impingement and entrainment have been conducted. The
Logan Generating Station in New Jersey withdraws 19 mgd from the Delaware River
through a 1 mm wedgewire screen. Entrainment data show 90 percent less entrainment of
larvae and eggs than conventional screens. No impingement data are available. 12°
Wedgewire screens have been considered or tested for several other large facilities. In
situ testing of 1 and 2mm wedgewire screens was performed in the St. John River for the
Seminole Generating Station Units 1 and 2 in Florida in the late 1970s. This testing
showed virtually no impingement and 99 and 62 percent reductions in larvae entrainment
for the 1 mm and 2 mm screens, respectively, over conventional screen (9.5 mm)
systems. In 1982 and 1983, the State of Maryland conducted testing using 1, 2, and 3 mm
wedgewire screens at the Chalk Point Generating Station, which withdraws water from
the Patuxent River in Maryland. The 1 mm wedgewire screens were found to reduce
entrainment by 80 percent. No impingement data were available. Some biofouling and
clogging were observed during the tests. In the late 1970s, Delmarva Power and Light
conducted laboratory testing of fine-mesh wedgewire screens for the proposed 1,540 MW
Summit Power Plant. This testing showed that entrainment offish eggs (including striped
bass eggs) could effectively be prevented with slot widths of 1 mm or less, while
impingement mortality was expected to be less than 5 percent. Actual field testing in the
brackish water of the proposed intake canal required the screens to be removed and
cleaned as often as once every 3 weeks.
6.2.8 Drum Screens
Drum screens are a horizontally-oriented screen that rotate a cylindrical screen (the drum)
along a shaft, with part of the screen exposed above the water's surface. Much like
vertical traveling screens, a spray wash cleans the screen when the screen is rotated above
the water.
6.2.8.1 Technology Performance
Drum screens are not commonly used in the U.S., but are more common in Europe.
Performance has been shown to range from 0 percent to 100 percent survival after 24
hours, depending on the hardiness of the impinged species. Much like screen systems in
the U.S., facilities and screen vendors have worked over the years to improve the design
and performance of these screens, including testing on spray wash systems, fish
collection devices, filtration, and other aspects.
6.2.8.2 Facility Examples
Summary Study
EPRI conducted a review of the drum screen and its performance at several facilities in
France over the past decades, including an assessment of impingement survival,
120 EPA conducted site visits to Westchester RESCO and Logan in April 2008 and January 2008,
respectively. See DCN 10-6517 andDCN 10-6509.
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improvements to the screens, and applicability for cooling water intakes in the U.S. See
DCN 12-6803.
6.3 Barrier nets
Barrier nets are nets that encircle the point of water withdrawal from the bottom of the
water column to the surface that prevent fish and shellfish from coming in contact with
the intake structure and screens. Of the 766 existing facility intakes that were reported in
the detailed questionnaires, at least eight intakes employ a barrier net. Barrier net mesh
sizes vary depending on the intake configuration, level of debris loading, species to be
protected, and other factors such as the waterbody, velocity and tides, and typically range
from 4 mm to 32 mm (EPRI 1999). Relatively low through-technology velocities are
usually maintained through the nets because the area through which the water can flow is
usually large. Most barrier nets are designed to prevent impingement and do not prevent
entrainment due to the large mesh size. Barrier nets are especially helpful in controlling
impingement during seasonal migrations offish and other organisms and to prevent
impingement of shellfish on the intake traveling screen. Shellfish pose a unique challenge
to the operation of traveling screens because they affix themselves to the screen; spray
wash pressure is not able to remove them from the screen.121 Barrier nets are often
removed from the water in winter to prevent damage from ice and to make any necessary
repairs. In some cases, the use of barrier nets might be further limited by the physical
constraints and other uses of the waterbody, such as navigation.
6.3.1 Technology Performance
Barrier nets have clearly proven performance for controlling impingement (i.e., more
than 80 percent reductions over conventional screens without nets) in areas with limited
debris flows. High debris flows can cause significant damage to net systems. Biofouling
can also be a concern but may be addressed through adequate maintenance.
6.3.2 Facility Examples
JP Pulliam Station
The JP Pulliam Station is located on the Fox River in Wisconsin. Two separate nets with
6 mm mesh are deployed on opposite sides of a steel grid supporting structure. The
operation of a dual net system facilitates the cleaning and maintenance of the nets without
affecting the overall performance of the system. Under normal operations, nets are
rotated at least two times per week to facilitate cleaning and repair. The nets are typically
deployed when the ambient temperature of the intake canal exceeds 37°F. This usually
occurs between April 1 and December 1.
121 In the proposed rule, EPA proposed requirements for marine facilities to install a barrier net to address
shellfish impingement. However, upon further study of the available impingement data for shellfish, EPA
has concluded that a separate set of requirements for shellfish is not necessary. See the preamble for more
information.
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Studies undertaken during the first 2 years after deployment showed an overall net
deterrence rate of 36 percent for targeted species (noted only as commercially or
recreationally important, or forage species). Improvements to the system in subsequent
years consisted of a new bulkhead to ensure a better seal along the vertical edge of the net
and additional riprap along the base of the net to maintain the integrity of the seal along
the bottom of the net. The improvements resulted in a deterrence rate of 98 percent for
some species; no species performed at less than 85 percent. The overall effectiveness for
game species was better than 90 percent while forage species were deterred at a rate of 97
percent or better.
JR Whiting Plant
The JR Whiting Plant is located on Maumee Bay of Lake Erie in Michigan. A 3/8-inch
mesh barrier net was deployed in 1980 as part of a best technology available
determination by the Michigan Water Resources Commission. Estimates of impingement
reductions were based on counts offish impinged on the traveling screens inside the
barrier net. Counts in years after the deployment were compared to data from the year
immediately prior to the installation of the net when over 17 million fish were impinged.
Four years after deployment, annual impingement totals had fallen by 98 percent.
Bowline Point
Bowline Point is located on the Hudson River in New York. A 150-foot long, 0.95-cm
mesh net has been deployed in a V-shaped configuration around the intake pump house.
The area of the river in which the intake is located has currents that are relatively stagnant,
thus limiting the stresses to which the net might be subjected. Relatively low through-net
velocities (0.5 fps) have been maintained across a large portion of the net because of low
debris loadings. Debris loads directly affecting the net were reduced by including a debris
boom outside the main net. An air bubbler was also added to the system to reduce the
buildup of ice during cold months. The facility has attempted to evaluate the reduction in
the rate of impingement by conducting various studies of the fish populations inside and
outside the barrier net. Initial data were used to compare impingement rates from before
and after deployment of the net and showed a deterrence of 91 percent for targeted species
(white perch, striped bass, rainbow smelt, alewife, blueback herring, and American shad).
In 1982 a population estimate determined that approximately 230,000 striped bass were
present in the embayment outside the net area. A temporary mesh net was deployed across
the embayment to prevent fish from leaving the area. A 9-day study found that only 1.6
percent of the estimated 230,000 fish were ultimately impinged on the traveling screens. A
mark-recapture study that released individual fish inside and outside the barrier net showed
similar results, with more than 99 percent offish inside the net impinged and less than 3
percent offish outside the net impinged. Gill net capture studies sought to estimate the
relative population densities offish species inside and outside the net. The results agreed
with those of previous studies, showing that the net was maintaining a relatively low
density offish inside the net as compared to the outside.
Chalk Point
Chalk Point is located on the Patuxent River in Aquasco, Maryland. The facility began
using barrier nets in 1982 to address problems with blue crab impingement. Initially, a
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single net was used, but a second net was later added to improve performance. Currently,
the outer net has a 1.25 inch square mesh and the inner net has a 0.75 inch square mesh.
Facility studies estimate a reduction in impingement of over 82 percent.
EPA conducted a site visit to Chalk Point in December 2007. See DCN 10-6504.
Dallman
Dallman is located on Lake Springfield in Springfield, Illinois. Since 1981, the facility
has used a barrier net at the mouth of its intake canal to reduce impingement at the
traveling screens. A study has shown a 90 percent reduction in impingement mortality.
6.4 Aquatic Filter Barrier
Aquatic Filter (or microfiltration) Barriers (AFBs), also known under the trade name
"Gunderboom," are similar to barrier nets in that they extend throughout the area of water
withdrawal from the bottom of the water column to the surface (see Exhibit 6-18).
However, AFBs consists of fabric panels with very small pores (less than 20 microns or
0.02 mm) manufactured as a matting of minute unwoven fibers. The full water-depth filter
curtain is suspended by flotation billets at the surface of the water and anchored to the
substrate below. Gunderboom systems also employ an automated "air burst" system to
periodically shake the material and pass air bubbles through the curtain system to clean off
sediment buildup and release any other material back into the water column. AFBs reduce
both impingement and entrainment because they present a physical barrier to all life stages.
These systems can be floating, flexible, or fixed. Because these systems usually have such
a large surface area, the velocities maintained at the face of the permeable curtain are very
low. EPA was aware of one facility that uses an AFB, but notes that this facility recently
ceased operations (for reasons unrelated to its use of its AFB).
Exhibit 6-18. Gunderboom at Lovett Generating Station
(image from Gunderboom)122
22 http://www.gunderboom.com/images/lovett.ipg
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6.4.1 Technology Performance
To date, the only facility where the Gunderboom was used at a full-scale level is the
Lovett Generating Station along the Hudson River in New York, where pilot testing
began in the mid-1990s. Initial testing at that facility showed significant potential for
reducing entrainment. Entrainment reductions of up to 82 percent were observed for eggs
and larvae, and these levels were maintained for extended month-to-month periods from
1999 through 2001. At Lovett, some operational difficulties affected long-term
performance. These difficulties, including tearing, overtopping, and plugging/clogging,
were addressed, to a large extent, through subsequent design modifications. Gunderboom,
Inc. specifically has designed and installed a microburst cleaning system to remove
particulates. As noted above, the Lovett Generating Station recently ceased operations.
Each of the challenges encountered at Lovett could be of significant concern at marine
sites, as these have higher wave action and debris flows. Gunderboom systems have been
successfully deployed in marine conditions to prevent migration of particulates and
bacteria, including in areas with waves up to 5 feet. The Gunderboom system is being
tested for potential use at the Contra Costa Plant along the San Joaquin River (a tidal
river) in northern California. An additional question related to the utility of the
Gunderboom and other microfiltration systems is sizing and the physical limitations and
other uses of the source waterbody. With a 20-micron mesh, 144 mgd and 288 mgd
intakes would require filter systems 500 and 1,000 feet long (assuming a 20-foot depth).
In some locations, this may preclude the successful deployment of the system because of
space limitations or conflicts with other waterbody uses.
AFBs have been installed at other sites for sediment control and exclusion of small
debris. More recent improvements to AFBs have reduced the effect of wave action and
debris (see DCN 10-6830).
6.4.2 Facilities Examples
As described above, the technology was installed at the Lovett Generating Station which
has ceased operations. EPA is not aware of any other existing industrial facilities
employing an AFB.
6.5 Offshore Intakes
The location of an intake inlet is important because those fish that are in close proximity
to the inlet are the most likely to be impinged and entrained. And since within
waterbodies the densities offish may vary with location, the location can have an impact
on impingement and entrainment. Intakes at a submerged offshore location can utilize
various inlet designs including open pipe, perforated pipe, cribs, wedgewire screens, and
velocity caps. Of these, only velocity caps and wedgewire screens are designed to reduce
impingement. By design, velocity cap technology is limited to application at submerged
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intakes and is often used to enhance the performance of submerged intakes.123 See
Sections 6.2.6 and 6.2.7.2 for discussions of wedgewire screens.
6.5.1 Intake Location
There are certain areas within every waterbody with increased biological productivity,
and therefore where the potential for I&E of organisms is higher. In large lakes and
reservoirs, the littoral zone (the shore zone areas where light penetrates to the bottom)
serves as the principal spawning and nursery area for most species of freshwater fish and
is considered one of the most productive areas of the waterbody. Fish of this zone
typically follow a spawning strategy wherein eggs are deposited in prepared nests, on the
bottom, or are attached to submerged substrates where they incubate and hatch. As the
larvae mature, some species disperse to the open water regions, whereas many others
complete their life cycle in the littoral zone. Clearly, the impact potential for intakes
located in the littoral zone of lakes and reservoirs is high. The profundal zone of lakes
and reservoirs is the deeper, colder area of the waterbody. Rooted plants are absent
because of insufficient light, and for the same reason, primary productivity is minimal. A
well-oxygenated profundal zone can support benthic macroinvertebrates and cold-water
fish; however, most of the fish species seek shallower areas to spawn (either in littoral
areas or in adjacent streams and rivers). Use of the deepest open water region of a lake or
reservoir (e.g., within the profundal zone) as a source of cooling water typically offers
lower I&E impact potential than use of littoral zone waters.
As with lakes and reservoirs, rivers are managed for numerous benefits, which may
include sustainable and robust fisheries. Unlike lakes and reservoirs, the hydrodynamics
of rivers typically result in a mixed water column and overall unidirectional flow. There
are many similarities in the reproductive strategies of shoreline fish populations in rivers
and the reproductive strategies offish within the littoral zone of lakes and reservoirs.
Planktonic movement of eggs, larvae, post larvae, and early juvenile organisms along the
shore zone is generally limited to relatively short distances. As a result, the shore zone
placement of CWISs in rivers might potentially impact local spawning populations of
fish. The impact potential associated with entrainment might be diminished if the main
source of cooling water is recruited from near the bottom strata of the open water channel
region of the river. With such an intake configuration, entrainment of shore zone eggs
and larvae, as well as the near-surface drift community of ichthyoplankton, is minimized.
Impacts could also be minimized by controlling the timing and frequency of withdrawals
from rivers. In temperate regions, the number of entrainable or impingeable organisms of
rivers increases during spring and summer (when many riverine fishes reproduce). The
number of eggs and larvae peak at that time, whereas entrainment potential during the
remainder of the year can be minimal.
In estuaries, species distribution and abundance are determined by a number of physical
and chemical attributes, including geographic location, estuary origin (or type), salinity,
temperature, oxygen, circulation (currents), and substrate. These factors, in conjunction
123 See below for the interaction of an offshore location and the use of a velocity cap. EPA has included a
provision in the final rule that deems some facilities with these criteria as employing BTA for
impingement.
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with the degree of vertical and horizontal stratification (mixing) in the estuary, help
dictate the spatial distribution and movement of estuarine organisms. With local
knowledge of these characteristics, however, the entrainment effects of a CWIS could be
minimized by adjusting the intake design to areas (e.g., depths) least likely to affect
concentrated numbers and species of organisms. In oceans, nearshore coastal waters are
typically the most biologically productive areas. The euphotic zone (zone light available
for photosynthesis) typically does not extend beyond the first 100 meters (328 feet) of
depth. Therefore, inshore waters are generally more productive due to photosynthetic
activity and due to the input from estuaries and runoff of nutrients from land.
During the development of the Phase III rule, EPA obtained data on densities of
ichthyoplankton in the Gulf of Mexico from the Southeast Area Monitoring and
Assessment Program (SEAMAP). This long-term sampling program collects information
on the density of fish larvae and eggs throughout the Gulf of Mexico.m EPA's analysis
showed that in general, ichthyoplankton densities are highest at sampling stations in the
shallower regions of the Gulf and lowest at sampling stations in the deepest regions. Over
600 different fish taxa were identified in the SEAMAP samples, including species of
commercial and recreational value.
In the proposed Phase I rule, EPA examined the possibility of limiting intakes being
located in the littoral zone as a regulatory approach.125 The Office of Naval Research
defines the littoral zone (for oceans) to extend 600 feet from shore.126 Other organizations
also recognize the value of locating an intake in less productive waters.127
There are only limited published data, however, quantifying the locational differences in
I&E rates at individual power plants. Some information, however, is available for
selected sites. For example:
• For the St. Lucie plant in Florida, EPA Region 4 permitted the use of a once
through cooling system instead of closed-cycle cooling by locating the outfall
1,200 feet offshore (with a velocity cap) in the Atlantic Ocean. This approach
avoided impacts on the biologically sensitive Indian River estuary.
• In Entrainment of Fish Larvae and Eggs on the Great Lakes, with Special
Reference to the D.C. Cook Nuclear Plant, Southeastern Lake Michigan (1976)
(DCN 8-5249), researchers noted that larval abundance is greatest within the area
from the 12.2-m (40-ft) contour to shore in Lake Michigan and that the abundance
of larvae tends to decrease as one proceeds deeper and farther offshore. This
finding led to the suggestion of locating CWISs in deep waters.
• During biological studies near the Fort Calhoun Power Station along the Missouri
River, results of transect studies indicated significantly higher fish larvae densities
124 EPA analyzed SEAMAP data in considering requirements for offshore facilities in the Phase III rule.
While this data is not directly relevant to existing facilities subject to the existing facility rule, it does offer
similar insights to the importance of intake location. See 71 FR 35013.
125 See 65 FR 49116 (August 10, 2000) for the proposed definition; generally speaking, the littoral zone is
regarded as a highly productive area in fresh and marine waters.
126 See http://www.onr.naw.mil/focus/ocean/regions/littoralzonel.htm.
127 See http://www.watereuse.org/sites/default/files/u8/IE White Paper.pdf. DCN 12-6848.
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along the cutting bank of the river, adjacent to the station's intake structure.
Densities were generally were lowest in the middle of the channel.
• Wisconsin Energy's Elm Road facility was recently constructed with a submerged
intake 1.5 miles offshore at a depth of 43 feet. The facility is using coarse mesh
cylindrical wedgewire screens with a through-slot velocity of 0.5 fps.
As discussed above, intake location can play an important role in determining the
potential for impingement and entrainment. However, for existing facilities, changing the
intake location is very limited in practice; many facilities simply do not have the option
available to them and when available, intake relocation tends to be among the most
expensive alternatives. Selecting an appropriate intake location is best considered when
siting a new intake or new facility.
6.5.2 Velocity Cap
Many offshore intakes are fitted with a velocity cap, a physical structure rising vertically
from the sea bottom and placed over the top of the intake pipe. Intake water is withdrawn
horizontally through openings in the velocity cap, converting the flow from a vertical
direction to a horizontal one at the entrance to the intake (see Exhibits 6-19 and 6-20).
The horizontal flow provides a physiological trigger in fish to induce an avoidance
response thereby reducing impingement mortality. Velocity caps are also configured with
supports and bar spacing designed to prevent larger aquatic organisms from entering the
intake pipe and swimming to the forebay. Of the 766 existing facility intakes that were
reported in the detailed questionnaires, velocity caps are used by at least 14 facilities.
Velocity caps are sometimes used in combination with other technologies to optimize
performance; often, the offshore intake will send water to a forebay at the shoreline,
where a second CWIS with traditional traveling screens will further screen the cooling
water. Because velocity caps operate under the principle that the organisms can escape
the current, velocity caps alone do not offer a reduction in entrainment.
However, velocity caps also work to minimize impingement and entrainment by virtue of
their location far offshore.128 In some waterbodies, shoreline locations are thought to
have the potential for greater environmental impact because the water is withdrawn from
the most biologically productive areas. As such, some facilities elect to employ an
offshore intake to withdraw from less productive areas in an effort to minimize
impingement and entrainment. Depth of the offshore intake is also a consideration as
deeper waters are often less biologically productive. Distance offshore and depth are very
site-specific variables and must be carefully evaluated prior to siting the offshore
intake.129 When compared with a shoreline intake, an offshore location may reduce
overall impingement and entrainment rates but may also alter the impingement and
entrainment species profile.
128 Refer to DCN 12-6601 and the preamble for a discussion of how EPA concluded that existing velocity
caps that meet certain criteria were determined to meet the impingement requirements of the final rule,
including an analysis of data for offshore locations, velocity caps, and the combination of the two
technologies.
129 The section on intake location previously in this chapter discusses these factors.
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§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 6-19. Velocity cap diagram
1.5H
VELOCITY CAP
•HP-U ,
HORIZONTAL INFLOW
V-0.5-I.Sfp«
Exhibit 6-20. Velocity caps prior to installation at Seabrook Generating Station
(Seabrook, NH)
6.5.3 Technology Performance
Relocating an intake from a shoreline location to a submerged offshore location can
result in lower impingement and entrainment depending on the site-specific biological
characteristics of the source waterbody. Impingement and entrainment reductions
associated with location alone are difficult to establish because they require either the
presence of both a shoreline intake and a submerged offshore intake without a velocity
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cap at the same facility or the collection offish density data within the water at separate
locations. Impingeable fish data was available from two facilities. One was for intakes
located 850 ft. offshore in 22 ft. deep water in Lake Ontario and the other was located
1,200 ft. offshore in the Atlantic Ocean in 24 ft. deep water. Two estimates are provided
for the second location. In both instances, the impingement reduction estimates are
developed by comparing fish density data from gill net sampling conducted close to shore
and close to the submerged intake. These limited data suggest that location alone can
account for 60 percent to 73 percent reduction in impingement. However, it is not clear
how this data relates to other waterbodies. These data suggest that impingement
reductions associated with a submerged offshore location alone may not be sufficient to
meet impingement standards.
Velocity caps reduce the number offish drawn into intakes based on the concept that fish
tend to avoid rapid changes in horizontal flow. This technology does not reduce
entrainment of free-floating eggs and larvae, which are unable to distinguish flow
characteristics or have sufficient swimming ability to avoid them. Estimates of the
performance of the velocity cap alone involve comparing the performance of separate
intakes located in the same general area or comparing the performance of the same intake
with and without the velocity cap. Seven sets of impingement performance data for the
velocity cap alone were available. For three of the intakes located in the Pacific Ocean in
California, performance was evaluated by reversing the flow between the intake and the
heated water discharge pipes, which are also located submerged far offshore and are open
pipes (i.e., have no screening technology). For two intakes, data were collected before
and after velocity caps were installed or replaced. For two intakes, data were collected for
separate intakes located in the same general area. The summary data indicate that velocity
caps alone can reduce impingement by 50 percent to 97 percent with an average of 78
percent and median of 82 percent. This data suggests that in more than half of the
velocity caps evaluated the velocity caps alone may provide sufficient impingement
reduction to meet the impingement reduction standard; however, for some intakes, the
velocity cap alone may not be sufficient.
At Huntington Beach and El Segundo in California, velocity caps have been found to
provide 80 to 90 percent reductions in fish entrapment.130 (See DCN 10-6603 for more
information.) At Seabrook Station in New Hampshire, the velocity cap on the offshore
intake has minimized the number of pelagic fish entrapped except for Pollock with an
estimated reduction for location and velocity cap combined of 76 percent based on
comparison to the Pilgrim plant located 65 miles away. Two facilities in England each
have velocity caps on one of two intakes. At the Sizewell Power Station, intake B has a
velocity cap, which reduces impingement about 50 percent compared to intake A.
Similarly, at the Dungeness Power Station, intake B has a velocity cap, which reduces
impingement about by 62 percent compared to intake A.
Impingement reductions observed at velocity cap facilities along the southern California
Bight have been generally been significant, with overall reductions ranging from 65 to
95 percent. These reduction values must be qualified, however, based on the methods
130 Entrapment refers to the number of impingeable fish drawn into the velocity cap. Under most
circumstances, these organisms will eventually be impinged on the traveling screens at the facility.
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used to collect and analyze the samples as well as the species on which the reduction is
calculated. Earlier studies, such as the 1985 El Segundo report, tended to focus on
commercially and recreationally important species only, leaving aside forage species that
were presumed to be of little value at the time.
Velocity cap performance may vary significantly based on temporal or local factors.
Significant diurnal fluctuations in impingement rates have been observed with nighttime
performance often well below daytime values. At Huntington Beach Generating Station,
for example, observed impingement rates were 12 to 37 percent higher during nighttime
collection.
In addition, there are several factors that may influence velocity cap effectiveness and
may be unique to southern California's facilities:
• It is worth nothing that coastal waters along the southern California Bight are
subject to short and long-term periodic shifts in ocean temperatures that can affect
the number and composition of species potentially affected by the intake. Two
major climatic factors, the Pacific Decadal Oscillation (PDO) and the El Nino
Southern Oscillation (ENSO), can significantly raise or lower water temperatures
compared with long-term averages. During the El Nino phase of the ENSO,
warmer waters from the south generally replace the cooler water of the California
Current along the bight. During the La Nina phase, the pattern may shift and
result in colder than normal temperatures. Each shift has the potential to alter the
species mix in the vicinity of the intake, with El Nino cycles driving cold water
species further from shore and into areas where they may be affected by the
intakes. Effects of El Nino/La Nina events may be magnified or moderated
depending on the concurring phase of the PDO, which may take 20-30 years to
complete a full cycle. Temperatures may fluctuate by 2.5° F or more during the
event peaks. Comparisons between historical and current information do show
differences in species abundance, although a direct correlation is difficult.
• Benefits of offshore intakes with respect to entrainment have not been studied in
as much detail as impingement, although recent sampling efforts by several
facilities offer a substantial data set from which entrainment reductions may be
calculated.
• At least one of southern California's coastal facilities with offshore intakes is
located in areas with rocky substrates that support giant kelp forests. These kelp
forests support larger nursery and spawning areas offshore than are generally
found off the Atlantic coast.
The impingement reduction performance of intakes submerged far offshore with velocity
caps is dependent on site-specific conditions. The available data suggests that locating an
intake far offshore alone may not result in compliance with the impingement reduction
standard. The available data also suggests that velocity caps alone may result in
compliance but not in all cases. However, the data strongly supports an assumption that
the combination of locating an intake far offshore (i.e., a minimum distance of 850 feet)
in combination with use of a velocity cap will result in compliance with the impingement
standard, especially in instances where an there is an expectation that the selected
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offshore location will result in reduced impingement compared to an intake located on
the shore line. See the preamble and DCN12-6601for more information.
6.5.4 Facility Examples
Huntington Beach Generating Station
Huntington Beach has one intake (equipped with a velocity cap) located 1,500 feet from
shore in Pacific Ocean. The intake is approximately 18 feet below Mean Lower Low
Water (MLLW) and 5 feet above intake riser. The initial study was conducted by the
University of Washington from 1978 through 1979. Velocity cap performance was
calculated by comparing the relative impingement rates of a capped versus uncapped
intake. This was done by reversing the intake and discharge locations, both of which are
located offshore in the same general area. Results from the comparative tests showed the
velocity cap was effective in reducing impingement by as much as 99 percent during the
day but as low as 53 percent at night. Overall effectiveness averaged 82 percent for all
sampling events regardless of time. As part of its NPDES permit requirements, the
facility has continued impingement monitoring during all heat treatments and
representative operating periods.
Entrainment analyses were not conducted at Huntington Beach in the late 1970s. Rather,
data collected at two other SCE facilities (Ormond Beach and SONGS) were used to
extrapolate Huntington Beach entrainment rates based on local conditions. Entrainment
performance was not calculated because source water references were not developed on
which any reduction could be based.
Huntington Beach conducted additional entrainment sampling in 2003 and 2004 as part
of its relicensing agreement with the State. These samples included source water
abundance monitoring at several reference monitoring stations located near the intake and
along the shoreline. Because these data were considered representative of current
conditions, Huntington Beach did not collect additional data in order to comply with
requirements for the Comprehensive Demonstration Study (CDS) under the 2004 Phase
II rule.
Various models were used to estimate entrainment impacts relative to the source water.
Several models were used to assess entrainment data, including adult equivalent loss
(AEL) model, fecundity hindcasting (FH), and empirical transport model (ETM); the
latter was used to estimate the percent mortality, which, in turn, provided the basis for
acres of production foregone (APF) estimates. Huntington Beach proposed to use this
method to determine the calculation baseline and any existing design credits under the
2004 Phase II rule.
Huntington Beach concluded that I&E impacts were not significant. Presumably, data
collected in 2003 and 2004 would be able to show entrainment rates relative to the source
waterbody abundance. Huntington Beach also conducted an entrainment survival study
(through condenser) in 2004.
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Scattergood Generating Station
Scattergood has one velocity cap located 1,600 feet from shore in Santa Monica Bay,
approximately 17 feet below MLLW. Site-specific evaluations of the velocity cap's
impingement performance were first conducted in the early 1970s when a storm damaged
the original velocity cap. The cap was removed and, at the request of California
Department of Fish and Game, left off so as to allow a comparison of impingement rates
between the capped and uncapped intake. The facility estimated the velocity cap's
impingement reduction effectiveness at 83 percent compared with the uncapped intake.
As part of its NPDES permit requirements, the facility has continued impingement
monitoring during all heat treatments and representative operating periods. A 2006 study
again compared the performance of a capped versus uncapped intake by reversing the
operating flows; effectiveness was calculated at 95 percent using a biomass metric and
more than 97 percent based on abundance.
Entrainment analyses at Scattergood were first conducted in 1978 and sampled
commercially and recreationally important species, as well as several forage species. The
study also examined the entrainment of invertebrate zooplankton. As part of its 2004
Phase II CDS compliance requirement, Scattergood conducted additional entrainment
monitoring in 2006. Samples were collected from several reference stations along the
shoreline and in the vicinity of the intake structure. In contrast to the 1978 efforts, all taxa
were identified as accurately as possible.
Various models were used to estimate entrainment impacts relative to the source water.
Several models were used to assess entrainment data, including adult equivalent loss
(AEL) model, fecundity hindcasting (FH), and empirical transport model (ETM); the
latter was used to estimate the percent mortality, which, in turn, provided the basis for
acres of production foregone (APF) estimates. Scattergood proposed to use this method
to determine the calculation baseline and any existing design credits under the 2004
Phase II rule. An aggregate "percent reduction" value is not explicitly presented in the
final report, although raw data are available from both the intake and reference stations
that would enable such a determination.
Scattergood bases its discussion of entrainment impacts on guidelines set forth in EPA's
1977 guidance document, which categorizes AEI as significant or insignificant relative to
the known source populations. Scattergood concludes that the current intake's impacts
are insignificant.
EPA conducted a site visit to Scattergood in August 2009. See DCN 10-6545.
El Segundo Generating Station
El Segundo has two intakes with velocity caps, located 2,600 feet from shore in Santa
Monica Bay, but only one is currently operational. The velocity caps are approximately
15 feet below MLLW.
The original velocity cap effectiveness study at El Segundo was conducted in 1958 and
consisted of a full year of impingement monitoring before and after the velocity cap was
installed, showing an impingement reduction of 95 percent.
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Entrainment analyses were not conducted at El Segundo in the late 1970s. Rather, data
collected at Ormond Beach were used to extrapolate El Segundo's entrainment rates
based on local conditions. These data are not considered reliable for El Segundo because
of the distance separating the two facilities (60 miles) and the sample collection and
analysis methods used that the time. Entrainment performance was not calculated because
source water references were not developed on which a reduction could be based.
El Segundo did conduct additional entrainment monitoring as part of its 2004 Phase II
CDS. Samples were collected at several reference monitoring stations along the
shoreline, further offshore, and in the vicinity of the intake. 131 Total entrainment values
were estimated based on actual and design flows.
Various models were used to estimate entrainment impacts relative to the source water.
Several models were used to assess entrainment data, including adult equivalent loss
(AEL) model, fecundity hindcasting (FH), and empirical transport model (ETM); the
latter was used to estimate the percent mortality, which, in turn, provided the basis for
acres of production foregone (APF) estimates. El Segundo proposed to use this method to
determine the calculation baseline and any existing design credits under the 2004 Phase II
rule.
El Segundo bases its discussion of entrainment impacts on guidelines set forth in EPA's
1977 guidance document, which categorizes AEI as significant or insignificant relative to
the known source populations. El Segundo concludes that the current intake's impacts are
insignificant.
EPA conducted a site visit to El Segundo in September 2009. See DCN 10-6552.
6.6 Other Technologies and Operational Measures
6.6.1 Physical Design
Several factors that are not directly related to the actual screen may play a significant role
in determining how many fish and shellfish are susceptible to impingement before
coming in contact with the screens. A comprehensive design approach that carefully
considers these factors prior to installing a screen system may yield significant benefits.
At existing facilities, however, many of these modifications are more problematic due to
space constraints and interference with existing systems, and may not be practical options
given their cost and complexity. One such factor, intake location, is discussed separately
under Section 6.5.1.
6.6.1.1 Intake Screen Orientation
An intake screen's orientation, specifically the angle at which it is offset from the
prevailing intake current, has been shown to aid motile fish from avoiding intake screens
131 The velocity cap transports water from offshore to a forebay, which is an area of water storage from
which conventional intake technologies (such as traveling screens and circulating water pumps) withdraw
cooling water for use in the facility.
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Chapter 6: Technologies and Control Measures § 316(b) Existing Facilities Final Rule - TDD
altogether. Together with man-made guiding structures or diversions, angled screens
minimize the initial impingement potential by diverting fish away from the screens to an
escape area or removal system such as a fish elevator or pump. Angled screening systems
have been effective in reducing impingement at SONGS, Oswego Harbor, and Brayton
Point, and can be modified to include modified Ristroph traveling screen design elements
to further reduce impingement mortality. These systems are not common, however, and
EPA did not examine this technology in detail nor study its performance.
6.6.1.2 Behavioral Triggers and Obstacles
A CWIS's initial design and configuration may unintentionally create artificial localized
environments that trigger behavioral responses in fish and may disorient or physically
affect them such that they become more susceptible to impingement. The CWIS's
induced flow may create shifting currents or quiescent zones leading to fish congregation
in critical areas. Man-made structures such as submerged conduits or artificial coves may
remove natural signals that allow fish to navigate and escape the intake flow.
At Moss Landing Power Plant in California, traveling screens were located at the end of a
300-foot submerged conduit, leaving many fish disoriented in total darkness and unable
to escape despite their physical ability to outswim the current. Many of these fish
ultimately tired and died on the traveling screens. The traveling screens were moved to
the upstream entrance eliminating the potential for entrapment in the dark conduit. The
facility reported a substantial decrease in the number offish impinged on the screens.
6.6.2 Reduce Intake Velocity
Intake velocity may be categorized into two types: approach and through-screen. The
approach velocity is generally defined as the localized velocity component perpendicular to
the screen face measured at a distance from the screen (often three inches) or if the intake
does not have a screen; it may be measured at the opening of the intake. Through-screen
velocity, as the term implies, is the velocity of water passing through the screen mesh
openings. This is difficult to measure in the field, but a reasonable velocity estimate can be
calculated by dividing the intake structure's flow rate by the total screen open area
submerged in the water column. Changes to either the water depth (tidal cycles or seasonal
flooding) or screen open area (from fouling or clogging) affects both velocity values if the
same intake flow is maintained. Likewise, sedimentation in front of the screens or intake
structure constricts the flow channel and increases the approach velocity.
The relationship between intake velocity and impingement is well-established since EPA's
Phase I rule (66 FR 65256). Impingement mortality can be greatly reduced by reducing the
through-screen velocity in any screen. EPA compiled fish swimming speed data as it varies
with the length of the tested fish and with water temperature into the graph presented in
Exhibit 6-21132. These data show that a 1.0 fps velocity standard would protect 78 percent
of the tested fish, and a 0.5 fps velocity would protect 96 percent of these fish.133 For some
132 This graph was originally developed in support of 316(b) Phase I and was presented in DCN 2-029 in
the Phase I Docket)
133 66 FR 28864 (May 25, 2001).
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 6: Technologies and Control Measures
species, a velocity less than 0.5 fps is necessary, e.g., the State of Alaska requires a velocity
limit of 0.1 fps to protect salmonids.134 Since screen fouling can increase the velocity in the
screen areas that remain open, EPA concluded that a through-screen velocity of 1.0 fps
may not be protective under the expected range of operating conditions and that a through-
screen velocity of 0.5 fps would provide a reasonable safety margin. (See DCN 2-028A
EPRI Technical Evaluation of the Utility of Intake Approach Velocity as an Indicator of
Potential Adverse Environmental Impact Under Clean Water Act 316(b).) As a result,
many existing facilities have designed and operate their modified traveling screens or
wedgewire screens so as not to exceed a through-screen velocity of 0.5 fps. Reducing the
intake velocity generally does not similarly reduce entrainment.
Exhibit 6-21. Graph of Swim Speed versus Body Length
Swim Speed Data
(Sources: EPRI, Riverkeeper/Turnpenny, Smith and Carpenter)
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6.6.3 Substratum Intakes
Studies and pilot projects are being conducted to investigate the viability of subsurface or
substratum cooling water intake structures, also known as filter beds. Historically,
substratum intakes have only been seriously considered for low flow facilities, smaller
than 1 mgd. Desalination drinking water facilities appear to be the predominant industry
utilizing substratum intakes in their operations. While extant in the United States,
operation of desalination facilities has so far been concentrated in Europe, North Africa,
and the Middle East. Some non-desalination drinking water facilities also use substratum
134
See DCN 1-5015-PR in the Phase I docket.
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Chapter 6: Technologies and Control Measures § 316(b) Existing Facilities Final Rule - TDD
water intakes. These facilities most commonly make use of vertical or horizontal beach
wells, which are shallow shoreline intake wells that use the overlying rock or sand layers
as a filter medium. Early investigations for use as cooling water intake structures have
yielded positive results, including 100 percent reduction of impingement and
entrainment. See DCN 10-6609 for more information.
A pilot study using a substratum intake was planned for 2008 for a site in New York to
withdraw about 245 mgd to operate a 400 MW power plant. The substratum intake was
expected to eliminate impingement and entrainment, and offer other benefits by reducing
operations and maintenance costs, requiring minimal downtime at installation, and
reducing fuel use in the summer. No information about the progress or results of this pilot
study is currently available.
6.6.4 Louvers
Louver systems are comprised of a series of vertical panels placed at an angle to the
direction of the flow (typically 15 to 20 degrees). Each panel is placed at an angle of
90 degrees to the direction of the flow (Hadderingh 1979). The louver panels provide an
abrupt change in both the flow direction and velocity. This creates a barrier that fish can
sense and avoid. Once the change in flow/velocity is sensed by fish, they typically align
with the direction of the current and move away laterally from the turbulence. This
behavior further guides fish into a current created by the system, which is parallel to the
face of the louvers. This current pulls the fish along the line of the louvers until they enter
a fish bypass or other fish handling device at the end of the louver line. The louvers may
be either fixed or rotated similar to a traveling screen. Flow straighteners are frequently
placed behind the louver systems.
In its 2007 Fish Protection at Cooling Water Intake Structures: A Technical Reference
Manual, EPRI concluded that the technology has produced variable results, but that well-
performing louvers can divert over 80 percent offish to a bypass. Louvers have also not
been widely employed at power plant intakes; most installations are at hydroelectric or
irrigation facilities.
While showing some promise for diverting fish (thereby reducing impingement), louvers
have not been widely used at power plants and have a very limited history of successful
deployment. Therefore, EPA has determined that this technology is unlikely to be utilized
by many existing facilities.
6.6.5 Behavioral Technologies
This category encompasses a wide range of technologies that utilize behavioral responses
in fish to induce an avoidance response and prevent the organism from entering the intake
structure. There are numerous examples: sound barriers, air bubbles curtains, strobe or
colored lights, chain link walls, and electric barriers. See Chapter 4 of the 2004 Phase II
TDD for additional information.
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 6: Technologies and Control Measures
Generally speaking, behavioral technologies have shown some ability to reduce
impingement. (These technologies are not effective for entrainment.) EPA analyzed data
from a number of studies in developing the impingement mortality standards; see Chapter
11 of this TDD. However, the performance tends to be species-specific; for example,
certain frequencies of sound are most effective for a certain fish species. This
characteristic makes these technologies difficult to employ on a wide scale, given that the
goal of the final rule is to reduce impingement of all species. Additionally, behavioral
technologies are not widely used. As a result, EPA did not study this class of
technologies any further.
6.7 Summary of Technology Performance
Exhibit 6-22 presents a qualitative graphical representation of the relative impingement
mortality reduction performance of many of the technologies described above that are
capable of reducing impingement mortality. The values shown are representative of the
median value and range of typical performance for properly-designed and well-operated
systems. Some performance studies are estimates only, and care should be taken not to
use this plot as a rigorous analysis of performance, but rather as a tool to show relative
performance. As can be seen, many technologies exhibited similar or better performance
than modified traveling screens (the selected BTA technology) but may be subject to
differences in availability.
Exhibit 6-22. Relative Technology Performance for Impingement Mortality
Reduction
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Chapter 6: Technologies and Control Measures
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 6-23 presents a similar graphical representation of the relative entrainment
reduction performance of many of the technologies described above that are capable of
reducing entrainment. Flow reduction via dry or wet cooling is clearly effective at
reducing entrainment. Submerged offshore intakes can also provide moderate reductions
in entrainment but the effectiveness and availability has limitations and the range of
reductions shown in Exhibit 6-23 is limited to sites with favorable conditions such as
relatively deep water applications in oceans and Great Lakes. Exhibit 6-23 shows that
there are fewer high performing technologies that reliably reduce entrainment and all are
subject to varying degrees of availability. Fine mesh screens are somewhat different from
the other technologies shown in Exhibit 6-23, as entrainment exclusion may approach
90 percent, but entrainment survival may approach 0 percent. As discussed earlier in this
chapter, the mean entrainment survival for 2 mm fine mesh is 12 percent, and therefore in
most cases this would not be considered a high performing technology.
Exhibit 6-23. Relative Technology Performance for Entrainment Reduction
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 6: Technologies and Control Measures
6.8 References
California Ocean Protection Council. 2008. California's Coastal Power Plants: Alternate
Cooling System Analysis. Available at
http://www.opc.ca.gov/webmaster/ftp/proiect_pages/OTC/engineering%20study/C
A_Power_Plant_Analysis_Complete.pdf Accessed March 2011.
Dixon, D. and J. Black. 2008. Fine-mesh Traveling Screens. Presentation for EPRI-EPA
Meeting. August 26, 2008.
EEA, Inc. 2005. Keyspan Generation LLC studies the substratum intake system: An
Innovative water intake system for power generation facilities. Environmental
Consulting Insights Newsletter. Spring, 2005.
Electric Power Research Institute. 2009. Beaudrey Water Intake Protection (WIP) Screen
Pilot-Scale Impingement Survival Study.
Electric Power Research Institute. 2008. Net Environmental Effects of Retrofitting Power
Plants with Once-Through Cooling to Closed-Cycle Cooling, May 2008
Electric Power Research Institute. 2007. Fish Protection at Cooling Water Intakes: A
Technical Reference Manual.
Electric Power Research Institute. 1999. Fish Protection at Cooling Water Intakes: Status
Report. TR-114013. EPRI, Palo Alto, CA.
Fletcher, I. R. 1990. Flow Dynamics and Fish Recovery Experiments: Water Intake
Systems. Transactions of the American Fisheries Society 119: 393-415
Gathright, Trent (EEVICO). 2008. Email to John Sunda, SAIC. Re: Question about
Traveling screen mesh area and fish buckets. August 22, 2008.
Hadderingh, R.H. 1979. Fish Intake Mortality at Power Stations, the Problem and its
Remedy. N.V. Kema, Arnheem, Netherlands. HydrologicalBulletin 13(2-3):
83-93.
Pagano, R. and W.H.B. Smith. 1977. Recent Developments in Techniques to Protect
Aquatic Organisms at the Intakes Steam-Electric Power Plants. MITRE Technical
Report 7671. November 1977.
U.S. Environmental Protection Agency (EPA). 2002. Technical Development Document
for the Proposed Section 316(b) Phase II Existing Facilities Rule. EPA-R-02-003.
U.S. Environmental Protection Agency, Washington, DC.
Voutchkov, N. 2005. SWRO desalination process: on the beach - seawater intakes.
Filtration & Separation 42(8):24-27, October 2005.
White, J.C. andM.L. Brehmer. 1976. "Eighteen-Month Evaluation of theRistroph
Traveling Fish Screens." In Third National Workshop on Entrainment and
Impingement. L.D. Jensen (Editor). Ecological Analysts, Inc., Melville, N.Y.
1976.
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Chapter 6: Technologies and Control Measures § 316(b) Existing Facilities Final Rule - TDD
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§ 316(b) Existing Facilities Final Rule - TDD Chapter 7: Regulatory Options
Chapter 7: Regulatory Options
7.0 Introduction
This chapter briefly discusses the technology bases and regulatory options EPA
considered for impingement and entrainment reduction controls. In the proposed rule,
EPA discussed four primary options. EPA also described additional options being
considered for impingement mortality controls to provide facilities greater flexibility in
achieving a BTA impingement mortality standard in its June 11, 2012 NOD A
(77 FR 34317). After a careful review of these proposed options, additional data, and
public comments on both the proposed rule and the two NOD As, EPA has opted to
promulgate BTA standards for the final rule that are similar to, but a modification of,
Proposal Option 1. The rule establishes the following BTA standards for Impingement
Mortality and Entrainment: Uniform Impingement Mortality Controls at All Existing
Facilities that withdraw over 2 mgd DIF; an Entrainment Standard based on Site-Specific
Entrainment Controls determined by the EPA or the State NPDES permitting authority
for Existing Facilities (other than New Units) that withdraw over 2 mgd DIF; Uniform
Impingement Mortality and Entrainment Controls for All New Units at Existing
Facilities. Refer to the preamble for a discussion of how the final rule varies from
Proposal Option 1, as well as EPA's rationale for selecting this option for the final rule.
Other options considered are described here.
7.1 Technology Basis Considered for the Proposed Regulation
As described in the preamble, EPA examined the full range of technologies that reduce
impingement or entrainment or both, and evaluated these technologies on the basis of
their efficacy in reducing impingement and entrainment, and their availability, which
includes feasibility and cost. From an assessment of these factors, EPA identified two
best performing technologies as the basis for today's final rule: modified traveling
screens with a fish-friendly fish return for impingement at existing facilities, and
mechanical draft wet cooling system for impingement and entrainment at new units.135
EPA did not identify any single technology or group of technology controls that it
concluded were available and feasible as the basis for establishing the national
performance standard for entrainment at existing facilities. Instead, EPA's national BTA
entrainment standard puts in place a framework for establishing entrainment requirements
on a site-specific basis. The framework includes the factors that must be considered in the
Director's determination of the appropriate BTA controls as well as the standard for
determining when an otherwise affordable control technology may be rejected as the
basis for the BTA standard. As described in the preamble, other technologies are
135 EPA identified a number of other technologies that can also be effective (e.g., reduced velocity, offshore
velocity cap) and has acknowledged this performance in creating several new compliance options in the
final rule. However, these technologies are not widely available or feasible at most sites, and therefore are
not part of the technology basis for the final rule.
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Chapter 7: Regulatory Options § 316(b) Existing Facilities Final Rule - TDD
demonstrated, but they are neither the best performing nor available technologies for the
industry as a whole.
7.1.1 Impingement Mortality Standards for Existing Facilities
EPA has concluded that modified traveling screens, such as modified Ristroph screens
and equivalent modified traveling screens with fish-friendly fish returns, are a best
performing technology for impingement mortality. EPA based the BTA impingement
mortality standard for existing units on the performance of traveling screens because EPA
concluded that this technology is effective, widely available, feasible, and does not lead
to unacceptable non-water quality impacts. These screens use 3/8 inch, or similar, mesh
with collection buckets designed to minimize turbulence, a fish guard rail/barrier to
prevent fish from escaping the collection bucket; "fish-friendly," smooth, woven or
synthetic mesh; and a low-pressure wash to remove fish before any high-pressure spray
to remove debris. The fish removal spray must be of lower pressure, and the fish return
must be fish friendly, such as providing sufficient water and minimizing turbulence, as
well as return to the source water body in a manner that does not promote predation or re-
impingement. Modified traveling screens generally must be rotated continually, which
minimizes aquatic exposure to impingement or to the air, and thus obtains the best
survival rates (correspondingly the highest reductions in impingement mortality).
Under one compliance option for impingement in the final rule, a facility may choose any
technology and then must conduct biological compliance monitoring to demonstrate the
12 month percent impingement mortality performance standard is achieved. As discussed
in Chapter 11 (see, for example, Exhibits 11-1 and 11-3), EPA based the impingement
mortality standard at 40 CFR 125.94(c) on data from facilities with traveling screens
modified with features to improve the post-impingement survival of organisms such as
smooth mesh, continuous or near-continuous rotation of the screens, buckets with guard
rails, low pressure sprays for collecting fish, and fish return systems. The statistical basis
for the impingement mortality standard includes 22 annual averages across 17 facilities
demonstrating average impingement mortality rates ranging from 1.6 to 48.8 percent
under conditions of 18 to 96 hour holding times. EPA established the 12 month percent
impingement mortality performance standard as 24 percent which is the arithmetic
average of the impingement mortality rates from the 17 facilities. (This is consistent with
EPA's proposed rule use of expected value of the beta distribution which can be
calculated as the arithmetic average.) EPA has occasionally used average annual
limitations in the effluent guidelines program, most recently for the pulp and paper
industry category (40 CFR 430, promulgated in 1998). In such instances, EPA has
defined the annual average limitations to be the average level demonstrated by the
technology. Thus, EPA's approach to calculating the 12 month standard for impingement
mortality is consistent with past practice.
EPA recognizes that variability in the technology performance occurs due to changes in
seasons, differing intake locations, higher mortality of certain species, and speciation
found in different water bodies. EPA has incorporated variability into the 12 month
average impingement mortality standard by basing its value on the actual data from
17 facilities which collectively performed more than 1,500 sampling events beginning as
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§ 316(b) Existing Facilities Final Rule - TDD Chapter?: Regulatory Options
early as 1977. EPA notes that seven facilities had mortality rates less than 10 percent
which provides evidence that facilities can, and have, maintained and operated their
systems in a manner consistent with the standard. Another four facilities demonstrated
impingement mortality rates significantly greater than the standard of 24 percent,
however, EPA notes these facilities were not required to optimize their technology
performance as part of their study, and data collection was not required to achieve a
certain level of performance.136 In each study, EPA has identified elements of the
technology operation that a facility could modify to achieve the impingement mortality
standard. By using the average annual performance, EPA has ensured that the resulting
standard reflects the widest range of potential conditions present in EPA's database. In
addition to those studies meeting the criteria for use in the 12 month standard
calculations, there are further studies in EPA's record that provide additional
performance data showing facilities can, and have, maintained and operated their systems
in a manner consistent with the standard. EPA's record includes approximately 250 total
studies related to impingement (see TDD Exhibit 11 A-l).
As explained in more detail in the preamble, the BTA technology for impingement does
not minimize adverse environmental impacts associated with entrainment.
7.1.2 Entrainment Standards for Existing Units
As discussed in Chapter 6 EPA's analysis of technology performance data identified
three technologies that performed well enough to serve as potential candidate best
performing technologies for establishing BTA entrainment standards: dry cooling; wet
closed-cycle cooling; and far offshore intake. As discussed in the preamble, EPA is not
basing BTA for entrainment at existing units (that is, excluding new units at existing
facilities) on a single technology such as closed-cycle recirculating cooling systems, the
best performing technology, because this technology is not available nationally. Although
EPA's record shows numerous instances of existing units that have performed a retrofit
to closed-cycle, EPA has not identified it as BTA. The availability of dry cooling is even
more restricted than wet closed-cycle cooling due to higher costs, higher turbine
efficiency penalties, and technical limitations (see Chapter 6). EPA also has not identified
any other available and demonstrated candidate technology for entrainment reduction that
is available nationally. For other entrainment technologies that might be available on a
site-specific basis, see the preamble and Chapter 6 of the TDD. EPA did not select the
other flow-reduction technologies (such as variable-speed drives and seasonal flow
reductions) as the technology basis for entrainment control measures because these
technologies are not uniformly best performing and are not broadly available for most
facilities. Further, EPA has not identified a basis for subcategorizing existing units at
which flow reduction technologies are feasible. The availability and utility to a given
facility of flow reduction methods depends on site-specific geographical and biological
conditions as well as operations of the facility. For example, this is the reason that EPA
136 For example, the Indian Point study states "Because of the preliminary nature of this study, the
effectiveness of the continuously operating fine mesh traveling screen has not been fully evaluated. Further
studies incorporating controls for survival testing, regulation of spray wash pressures, collection efficiency
tests, sampling during peak impingement periods for all important species, and better holding facilities, will
provide more conclusive results."
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Chapter?: Regulatory Options § 316(b) Existing Facilities Final Rule - TDD
did not select relocation of a shoreline intake to far offshore as a technology basis for the
BTA entrainment standard because this technology is not widely available for most
facilities.
7.1.3 Impingement and Entrainment Standards for New Units at
Existing Facilities
In contrast to existing units, installing a closed-cycle cooling system at a new unit is far
less complex. The technology is also highly effective, as mechanical draft (wet) cooling
towers achieve flow reductions of 97.5 percent for freshwater and 94.9 percent for
saltwater sources by operating the towers at a minimum of 3.0 and 1.5 COC, respectively.
These reductions in flow (and the concurrent reductions in impingement and entrainment
impacts) are among the highest reductions in impact possible at an intake structure.
As described in the preamble, EPA has concluded that new units, in contrast to existing
units, have much greater flexibility in terms of cooling system design, construction
scheduling, and other factors that help minimize many of the negative aspects associated
with closed-cycle cooling.
On the basis of the high levels (greater than 95 percent on average) of flow reduction
obtained by optimized cooling tower operation and the availability, feasibility and
affordability of closed-cycle cooling at new units, EPA has identified wet cooling
systems as the best performing technology for both impingement mortality and
entrainment for new units at existing facilities.
7.2 Options Considered
EPA has promulgated a modified version of Proposal Option 1, as described in the
proposed rule and modified by elements described in the NOD As. Refer to the preamble
for additional discussion.
7.2.1 Final Rule
7.2.1.1 Impingement Mortality Requirements
The final rule requires that existing facilities and new units subject to this rule must
comply with one of the following seven alternatives identified in the national BTA
standard for impingement mortality at 40 CFR 125.94(c) (hereafter, impingement
mortality standards):
(1) operate a closed-cycle recirculating system as defined at 40 CFR 125.92;
(2) operate a cooling water intake structure that has a maximum through-screen
design intake velocity of 0.5 fps;
(3) operate a cooling water intake structure that has a maximum through-screen
intake velocity of 0.5 fps;
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§ 316(b) Existing Facilities Final Rule - TDD Chapter?: Regulatory Options
(4) operate an offshore velocity cap as defined at 40 CFR 125.92 that is installed
before the promulgation date of the final rule;
(5) operate a modified traveling screen that the Director determines meets the
definition at 40 CFR 125.92 and that the Director determines is the best
technology available for impingement reduction;
(6) operate any other combination of technologies, management practices and
operational measures that the Director determines is the best technology available
for impingement reduction; or
(7) achieve the specified impingement mortality performance standard.
Options (1), (2) and (4) above are essentially "pre-approved technologies" requiring no
demonstration and minimal compliance monitoring to show that the flow reduction and
control measures are functioning as EPA envisioned. Options (3), (5) and (6) require
more detailed information be submitted to the Director before the Director may specify it
as the requirement to control impingement mortality. Because the technology basis for
these three alternatives includes technologies known to be high performing technologies,
these compliance alternatives are "streamlined" in that once the technology is installed
and its performance optimized, there is little or no biological compliance monitoring
required. The impingement mortality performance standard in Option (7) requires that a
facility must achieve a 12 month impingement mortality performance for all life stages of
fish and shellfish of no more than 24 percent mortality, including latent mortality, for all
non-fragile species that are collected or retained in a sieve with maximum opening
dimension of 0.56 inches and kept for a holding period of 18 to 96 hours.
7.2.1.2 Entrainment Requirements
The final rule establishes the national BTA standard for entrainment at existing facilities
at 40 CFR 125.94(d) (hereafter, entrainment standards) for both existing units and new
units at existing facilities. In the case of existing units, the rule does not prescribe a single
nationally applicable entrainment reduction technology but instead requires that the
Director must establish the BTA entrainment requirement for a facility on a site-specific
basis. The requirements must reflect the Director's determination of the maximum
reduction in entrainment warranted after consideration of all factors relevant to the BTA
determination at the site and must include consideration of the specific factors spelled out
in 40 CFR 125.98(f). Facilities that withdraw greater than 125 mgd AIF must develop
and submit an Entrainment Characterization Study (40 CFR 122.21(r)(9), as well as
provide other information required at 40 CFR 122.2l(r)(7) and (10), (12), (13) and,
unless waived by the Director, (11)) that must include specified data pertinent to
consideration of several of the factors identified in 40 CFR 125.98(f).
The owner or operator of a new unit at an existing facility must achieve one of two
alternatives under the national BTA standards for entrainment for new units at existing
facilities at 40 CFR 125.94(e) (hereafter, new units entrainment standards).13? Under the
137 New units are also subject to impingement requirements at 40 CFR 125.94(b) but EPA expects that all
new units will comply with these requirements through the installation of a closed-cycle cooling system,
which is one of the compliant technologies identified in the final rule for impingement mortality.
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Chapter?: Regulatory Options § 316(b) Existing Facilities Final Rule - TDD
first alternative new unit entrainment standard, the owner or operator of a facility must
reduce AIF at the new unit, at a minimum, to a level commensurate with that which can
be attained by the use of a closed-cycle recirculating system. The owner or operator of a
facility with a cooling water intake structure that supplies cooling water exclusively for
operation of a wet or dry cooling tower(s) and that meets the definition of closed-cycle
recirculating system at 40 CFR 125.92 meets this new units entrainment standard. Under
the second alternative new units entrainment standard, the owner or operator of a facility
must demonstrate to the Director that it has installed, and will operate and maintain,
technological or other control measures for each intake at the new unit that achieves a
prescribed reduction in entrainment mortality of all stages offish and shellfish that pass
through a sieve with a maximum opening dimension of 0.56 inches. Like the Track II
requirement in the earlier Phase I rule, the owner or operator of a facility must
demonstrate entrainment mortality reductions that are equivalent to 90 percent or greater
of the reduction that could be achieved through compliance with the first alternative
entrainment standard for new units.
7.2.2 Other Options Considered
EPA considered several other options in developing today's final rule, but ultimately
rejected them. This section includes a discussion of these options, as well as some
technologies that EPA considered, but did not include as alternatives to the impingement
mortality standards. Refer to the preamble for additional discussion.
1. Closed-Cycle Recirculating Systems as National BTA to Address Impingement
and Entrainment
As previously explained, EPA assessed a number of different technologies that reduce
impingement mortality and entrainment as the possible basis for section 316(b)
requirements. EPA concluded that closed-cycle recirculating systems (based on wet
cooling towers) are a best performing technology for reducing impingement mortality
and entrainment.
Notwithstanding that conclusion, EPA has decided not to establish a performance
standard for entrainment based on closed-cycle recirculating systems. Closed-cycle
cooling is not the "best technology available for minimizing adverse environmental
impact" required by section 316(b). Closed-cycle cooling is indisputably the most
effective technology at reducing entrainment given the direct relation between
entrainment and flow. Closed-cycle reduces flows by 96 percent (on average) and
consequently impingement mortality and entrainment are similarly highly reduced.
Because of concerns over technical feasibility, EPA has rejected closed-cycle
recirculating systems as the basis for national entrainment controls. Though closed-cycle
cooling is effective and a high performing technology, it is neither widely available nor
feasible, and has unacceptable non-water quality impacts in some instances. While EPA
cannot identify with precision the extent of these limitations on installing closed-cycle
cooling systems nationwide, the record indicates that the circumstances are neither
isolated nor insignificant. EPA estimates that 25 percent of existing facilities may face
some geographical constraints on retrofitting closed-cycle cooling. EPA also considered
other forms of flow reduction including variable speed drives and seasonal outages. EPA
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found that these were not available and not BTA. Further, EPA has decided that 316(b)
requirements should reflect consideration of costs and benefits.
EPA rejected a variant option of requiring uniform entrainment controls based on closed-
cycle cooling, with the opportunity for individual facilities to show why such controls are
not feasible. EPA's decision not to establish closed-cycle cooling as BTA with "off
ramps" is broader than its consideration of a land threshold. Because of a combination of
concerns over land availability, air emissions, and remaining useful life of the facility,
EPA has rejected closed-cycle recirculating systems as the basis for national
impingement and/or entrainment requirements. Nor is EPA able to identify a subcategory
for which these concerns no longer apply. Moreover, the complex interaction of all of
these factors at individual sites does not lend itself to other regulatory options that would
require closed-cycle recirculating systems with an "off ramp" if any of the factors were
shown to result in unacceptable impacts because this would create a presumption for
closed-cycle cooling rather than an equal balancing of all relevant factors. EPA decided
not to put its thumb on the site-specific scale by establishing any presumptive BTA
entrainment outcome. EPA finds the entrainment standards framework in today's final
rule will provide a consistent, more efficient, and more effective approach than standards
with an "off ramp."
2. Proposal Option 3—Impingement Mortality Controls at All Existing Facilities
that Withdraw over 2 mgd DIP; Require Flow Reduction Commensurate with
Closed-Cycle Cooling at All Existing Facilities over 2 mgd DIP
Proposal Option 3 was, in many ways, the same as requiring closed-cycle cooling at all
existing facilities. As described above, the rationale for rejecting closed-cycle cooling as
BTA for entrainment would apply with equal force for Proposal Option 3. As a result,
EPA has concluded Proposal Option 3, similarly, is not available at the national level as
BTA for entrainment. EPA is not reporting in the preamble or support documents on any
updates since proposal to the analysis of this option.
3. Proposal Option 2—Impingement Mortality Controls Similar to Final Rule at All
Existing Facilities that Withdraw over 2 mgd DIP; Require Flow Reduction
Commensurate with Closed-cycle Cooling by Facilities greater than 125 mgd DIF
and Uniform Impingement Mortality and Entrainment Controls for All New Units
at Existing Facilities
As described above, the rationale for rejecting closed-cycle cooling as BTA for
entrainment would also apply in the case of Proposal Option 2, despite the smaller
number of facilities that would be subject to a requirement to retrofit. As a result, EPA
concluded that Proposal Option 2 is not available at a national scale as BTA for
entrainment.
4. Proposal Option 4—Impingement Mortality Controls Similar to Final Rule at
Existing Facilities with DIF of 50 mgd or more; BPJ Permits for Existing
Facilities with Design Intake Flow between 2 mgd and 50 mgd; Uniform
Impingement Mortality and Entrainment Controls for All New Units at Existing
Facilities Similar to Final Rule
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EPA ultimately rejected Proposal Option 4 because EPA found that the final rule is
available, feasible, and demonstrated for all regulated facilities on a national basis.
Moreover, EPA's analysis showed that the difference in the total compliance costs for the
two options was nominal. Additionally, many facilities with a DIP under 50 mgd already
use closed-cycle cooling and would have minimal burden under this approach. These
facilities would have no difficulty complying with either the final rule or Proposal Option
4. Proposal Option 4, by not distinguishing between those facilities under 50 mgd that
have already minimized adverse environmental impacts from those that have not, masks
the actions that would have to be taken by the latter group to comply with today' final
rule. In addition, the flexibilities introduced in the June 11, 2012 NOD A and included in
today's final rule are applied to all facilities, not just the facilities withdrawing smaller
volumes of cooling water addressed by Proposal Option 4. EPA also concluded that the
data collection activities required under the final rule will be more protective of
threatened and endangered species because it provides information on a larger number of
facilities than Proposal Option 4 for consideration by the Director in permitting decisions.
Lastly, EPA acknowledges that Proposal Option 4 is more burdensome to permitting
authorities than is the final rule, as it requires more site-specific decision-making,
including site-specific determinations regarding permit application study requirements,
monitoring requirements, and case-by-case decisions of BTA for impingement mortality.
Under Phase III, EPA co-proposed three options where requirements similar to those
under Phase II would apply to all facilities with a DIP greater than 50 mgd (option 5),
greater than 200 mgd (option 8), and greater than 100 mgd (Option 9)138. Requirements
for all other facilities would be established on a case-by-case best professional judgment
basis. EPA evaluated other alternative options under Phase III including Option 6 which
expanded the coverage of regulatory requirements to include all facilities with a DIP
greater than 2 mgd. While the subset of facilities subject to specific EVI and E
requirements in proposed Phase III option 5 (greater than 50 mgd) is similar to those
subject to EVI requirements under this rule's Option 4, the Phase III option 5 is not the
same in that the requirements are different and, as a result, the compliance costs and
burden to the facilities are lower. These differences under this rule include site-specific
entrainment requirements, reduced biological monitoring requirements and flexibilities in
selecting compliance alternatives for complying with BTA impingement mortality
requirements. The difference in estimated total annualized costs for the two Phase III
options (Option 5 and Option 6) of $69 million139 (in 2013 dollars) is representative of
what the Phase III requirement costs would have been for facilities in the 2 to 50 mgd
subset. The comparable estimate for the impingement mortality requirements for
2-50 mgd facilities under this final rule is $25 million in 2013 dollars. Thus, EPA
estimates that the changes in requirements considered in the proposed Phase III options to
those in today's rule have reduced the potential for imposed financial stress on the 2 to
50 mgd facilities by an estimated $44 million dollars ($69 million minus $25 million).
138IM and E requirements for Phase III option 9 (greater than 100 mgd) was limited to facilities located on
oceans, estuaries and Great Lakes.
139 $69 million is the inflation adjusted difference of $49.2 million between Phase III option 6 annualized
cost of $94 million minus the Phase III option 5 (greater than 50 mgd) cost of $44.8 million adjusted to
2013 using ENR CCI. Option 6 costs are for an estimated 603 affected facilities including 91 small
businesses.
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§ 316(b) Existing Facilities Final Rule - TDD Chapter?: Regulatory Options
The resulting estimated financial impact under today's rule results in no facilities with a
cost-to-revenue ratio of 3 percent or greater (versus 13 facilities for Phase III Option 6),
and four facilities with a cost-to-revenue ratio exceeding 1 percent (versus 23 facilities
for Phase III option 6); further the analysis for today's rule assumes zero cost pass-
through to the consumer. See the EA for further details. Thus, EPA's conclusions under
Phase III regarding costs are not relevant to EPA's rejection of Option 4. EPA has
concluded that it does not have a rationale for excluding facilities in the 2 to 50 mgd
range from the national uniform requirements because there are affordable, available, and
feasible technologies for reducing impingement mortality.
5. Proposal Option 2 Variant
EPA also considered a variation of Proposal Option 2 that would have used 125 mgd AIF
rather than 125 mgd DIP as the threshold. However, as described above, EPA rejected
Proposal Option 2 and, for the same reasons, rejected this variant of Option 2.
6. Site-Specific Approach to Addressing Impingement
EPA considered a site-specific approach to addressing impingement mortality, similar to
that employed for entrainment. Similarly, EPA considered an approach that would have
established both impingement mortality and entrainment requirements fully on a site-
specific basis taking into account for the particular facility, among other factors, those
previously described as pertinent to EPA's 316(b) BTA determination. EPA rejected a
fully site-specific approach for impingement controls principally because low-cost
technologies for impingement mortality are available, feasible, and demonstrated for
facilities nationally, and because a fully site-specific approach would place unnecessary
burden on state permitting resources. Moreover, the final impingement mortality standard
includes several alternatives that allow site-specific demonstration that a particular
technology performs at a level representing the best technology available for the site.
EPA is instead promulgating a modified version of the proposed rule, adding several
elements of flexibility, and thus directly addressing many of the concerns raised by these
commenters.
7. Closed-Cycle Cooling to Address Impingement Mortality
EPA did not select flow reduction commensurate with closed-cycle cooling as the
technology basis for impingement mortality because, despite the incremental
improvement in reducing impingement, the cost of closed-cycle cooling is more than
10 times that of modified traveling screens with a fish return system. As a result,
modified traveling screens with a fish return system are more cost-effective than flow
reduction commensurate with closed-cycle cooling at preventing impingement mortality.
8. Pre-approved Technologies
EPA considered an approach based on "pre-approved" technologies that, once installed,
would obviate the need for extensive regulatory conditions such as biological monitoring.
This is similar to the approach taken for cylindrical wedgewire screens in the remanded
2004 Phase II rule (see 40 CFR 125.99(a)). EPA has included several streamlined
compliance alternatives in the form of technologies that may be approved following a
demonstration of required performance, so long as the facility shows that its alternative
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technology is operating in a manner that minimizes adverse environmental impacts. As
an option for achieving the impingement mortality standards, a facility may install and
operate specified impingement controls that EPA has determined will comply with the
numeric impingement mortality performance standard.
9. Barrier Nets
For estuaries and oceans, EPA proposed seasonal deployment of barrier nets on marine
waters to address impingement mortality of shellfish (crustaceans). Following EPA's
analysis of additional data described in the June 11, 2012 NOD A, EPA has incorporated
data regarding shellfish impingement survival rates into the numeric impingement
mortality performance standard in the final rule, thereby eliminating the need to require
barrier nets. However, EPA does recognize that barrier nets may be an appropriate
measure for the protection of shellfish at some facilities and therefore has included a
provision that gives the Director discretion to require additional measure for the
protection of shellfish.
10. Cylindrical Wedgewire Screens
EPA did not select wedgewire screens as the technology basis for impingement mortality
controls because wedgewire screens are not available and feasible for all existing
facilities. EPA also did not need to include wedgewire screens as a pre-approved
compliance alternative for impingement controls because wedgewire screens are typically
designed with an intake velocity of 0.5 fps and therefore, can demonstrate compliance
with the impingement mortality standard under the intake velocity compliance
alternative. This approach results in wedgewire screens as potentially being approved in
situations where the Phase II rule would not, such as in lakes or oceans or locations
where the currents are not counter and perpendicular to the wedgewire screens.
11. No rule.
EPA considered a "no regulatory action" option. EPA determined that "no action" is
inappropriate in this case because there are technologies that are available, demonstrated,
feasible, and affordable for all facilities, and EPA has found the costs of such controls are
justified by the benefits. EPA found this rule to be necessary to minimize AEI based on
the record, noting the mortality of hundreds of billions of aquatic organisms that are
impinged and entrained at cooling water intakes that withdraw water from waters of the
United States each year.
12. Intake velocity
EPA considered an option based on intake velocity of 0.5 feet per second. The 0.5 fps
velocity is based on the analysis offish burst swim speeds, and is therefore based on the
thousands of intake structures where such fish and shellfish may be located. However,
this is not BTA because it is not available. See Chapter 6 regarding availability of this
technology.
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13. Cost-cost option
The inclusion of a cost-cost variance as a rule option was considered to avoid the
irrational result of requiring a facility to install a technology where that facility has
unique, site-specific characteristics that cause individual compliance costs to be many
times greater than those compliance costs considered by EPA. EPA found that the cost-
cost test it had adopted in the Phase II rule would have proved difficult to implement in
part because the Appendix to the Phase II rule discussing how to apply the test was prone
to uncertainty and error. EPA notes that the Phase II rule included requirements for
entrainment reductions, and the final Phase II rule was more costly than today's rule even
though it only addressed existing large flow electric generating facilities.
While not required to do so, the final rule includes sufficient flexibility to allow facilities
to avoid exceptional costs. EPA accomplished this by structuring the final rule to allow
facilities to choose from multiple impingement mortality compliance alternatives
presenting facilities with a range of different costs associated with each alternative. Thus,
facilities are free to choose the lowest cost alternative. These include streamlined
alternatives based on modified traveling screens or a system of technologies that are
intended to result in reduced long-term costs by reducing future monitoring requirements.
Also the final rule allows the Director to conclude based on site-specific data that
impingement mortality at the site is de minimis and therefore no additional controls are
warranted to meet the BTA impingement mortality standard. EPA has determined that the
available compliance alternatives provide sufficient flexibility, and that the costs of such
controls is sufficiently low such that no facility will experience an exceptional level of
cost and need a cost variance.
7.2.3 Existing offshore oil and gas extraction facilities and seafood
processing vessels
There are three main technologies applicable to the control of impingement and
entrainment of aquatic organisms for cooling water intakes at offshore industry sectors
evaluated for this rulemaking: passive intake screens, velocity caps, and modification of
an intake location. EPA did not identify any technologies that are demonstrated and
feasible for the industry. Thus EPA did not develop options for these categories. See
DCN 12-6621 and the Phase III rule TDD for more information.
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§ 316(b) Existing Facilities Final Rule -TDD Chapters: Costing Methodology
Chapter 8: Costing Methodology
8.0 Introduction
This section describes the methodology and assumptions used to derive the technology
compliance costs for facilities required to meet the final rule. For existing facilities, the
Agency developed costs for 723 intakes at 519 model plants and these were then used in
the economic analysis to scale to the total universe of in-scope facilities140. For new units
subject to impingement mortality and entrainment mortality reduction requirements, the
Agency derived estimates of new unit capacity and cooling water requirements and
derived estimated annual compliance costs. In many ways, EPA used a similar,
standardized approach to what was used in the previous 316(b) rules. For regulatory
options where facilities were required to meet impingement mortality requirements (for
which the technical basis is modified Ristroph screens) or make intake technology
upgrades, EPA used a revised version of the cost tool developed in the Phase III
regulation (and largely based on the cost modules developed for the 2004 Phase II rule).
For regulatory options where facilities were required to meet entrainment mortality
requirements (for which the technical basis is wet cooling towers), EPA used a cost
model developed by the Electric Power Research Institute (EPRI) to develop costs for
retrofitting wet cooling towers. EPA used facility-specific data from each facility that
completed a detailed technical questionnaire (DQ) to create model facilities. By
providing facility-specific data as an input to the cost models, EPA determined model
facility compliance costs for each intake structure based on data from each DQ.
EPA diverged from the cost methodology in the 2004 Phase II rule in one key respect: the
costs derived for the final rule use a model facility approach.141 In contrast, the 2004
Phase II rule used a facility-specific costing approach where compliance costs attributed
to every facility were calculated. For reasons discussed below, EPA determined that a
model facility approach (where costs for a set of model facilities are calculated and then
scaled to a national level) was more appropriate in determining the compliance costs for
the final rule. By costing each DQ facility as a model facility, and by using the survey
weights developed for the DQ,142 EPA is able to estimate total national costs.
EPA also developed costs for manufacturers and small power plants (formerly addressed
under the Phase III rule), which are subject to the same requirements as large power
plants under the final rule. The general process of developing costs for these facilities
was the same as that for large power plants, with some differences as discussed below.
140 These totals include intakes at facilities determined to be baseline closures in the economic analysis.
141 Model facilities are statistical representations of existing facilities (or fractions of existing facilities);
only those facilities that completed a DQ in EPA's survey effort in 2000 were included in cost
development.
142 The weighting factors were statistically derived from the industry questionnaire data using survey
sample sizes. Weights range from 1 to 8.7. By weighting each model facility, the traits of the model facility
(e.g., flow, technology type, capital costs) are extrapolated to represent the entire universe of facilities.
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EPA analyzed the compliance costs on two levels. First, as described in Chapter 7, EPA
analyzed several regulatory options to address impingement mortality (EVI) and
entrainment mortality (EM), including intake screens and flow reduction commensurate
with closed-cycle cooling. Second, EPA assessed the national economic impacts of each
regulatory option. The sections below describe these costs further.
8.1 Compliance Costs Developed for the Final Rule
The final rule requires that all existing facilities must meet impingement mortality
requirements. Entrainment requirements for existing units may be established on a best
professional judgment basis by the Director. For new units not subject to Phase I, the
final rule requires intake flow reduction commensurate with closed-cycle cooling. The
cost methodology used to estimate compliance costs for new units is described in Section
8.4 below. EPA also considered two other options involving closed-cycle cooling: one
where all existing facilities would be required to reduce their intake flow to that
commensurate with closed-cycle cooling; and one where all existing facilities with an
average intake flow (AIF) above 125 million gallons per day (mgd) would be required to
reduce their intake flow to that commensurate with closed-cycle cooling. As described in
the preamble to the final rule, the technology basis for these requirements is jointly based
on the performance of modified traveling screens (for impingement mortality) and the
performance of closed-cycle wet cooling towers (for entrainment mortality).
To develop appropriate compliance costs, EPA assigned costs for both sets of facilities.
For facilities that are required to upgrade their screens, EPA used an updated version of
the cost tool developed in the Phase III rule. For the facilities that are required to reduce
their intake flow, EPA used a cost model developed by EPRI to develop capital and
operation and maintenance (O&M) costs for retrofitting cooling towers at each model
facility.143
8.1.1 Model Facility Approach
The model facility approach used in this effort involved calculating compliance costs for
individual facilities for which EPA had detailed technical data regarding the intake design
and technology. Specifically, these are the in-scope facilities that completed the year
2000 DQ survey. For facilities with screen upgrades, where facilities reported data for
separate cooling water intake structures (CWISs), compliance costs were derived using
the design intake flow for each intake and then these intake costs were summed to obtain
total costs for each facility. For facilities required to reduce their flow, the EPRI model
was applied to the maximum intake flow reported for each intake over the period 1996 to
1998. The facility's total costs were then multiplied by a weighting factor specific to each
facility to obtain industry-wide costs for the national economic impacts analyses by
extrapolating the impacts of the DQ facilities to all existing facilities.
143 In some cases, a facility may have been assigned costs for both cooling towers and screen upgrades; if a
facility's characteristics suggested that, even after reducing flow, its intake velocity would still exceed
0.5 ft/sec, costs for Ristroph screens were also included. See Section 5 below.
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§ 316(b) Existing Facilities Final Rule -TDD Chapters: Costing Methodology
The reasons for using a model facility approach include the following:
• Technical data for non-DQ facilities144 was limited; specifically:
o Design intake flow (DIP) volume was not requested, and values used
previously by EPA were estimated on the basis of reported average flow.
o Available intake technology data was generalized, and EPA could not be
certain how reported technologies were distributed among multiple intakes.
o Available intake technology data was not detailed enough to reliably ascertain
whether the technology design met compliance requirements.
• EPA's industry questionnaire conducted a census of power plants expected to be
within the scope of the regulations, but conducted a stratified sampling of
manufacturers. As a result, EPA's survey data only encompasses a representative
sample of manufacturers; information on unsurveyed facilities is not available.
• The survey sample frame did not include facilities in U.S. territories such as
Puerto Rico and Guam, and the model facility approach allowed their inclusion
using the weighting factors.
• Implementation of the 2004 Phase II rule revealed inconsistencies and errors in
the costs for non-DQ facilities.
8.2 Impingement Mortality Compliance Costs
Compliance with EVI requirements was based on the performance of an upgraded
traveling screen technology—a modified Ristroph-type traveling screen or equivalent,
plus a fish-friendly fish return system. Facilities may also comply with EVI requirements
by demonstrating that their design intake velocity is 0.5 feet per second or less; that the
cooling water system meets the definition of closed-cycle cooling; or that they meet the
definition of existing offshore velocity cap.
For both power generation and manufacturing facility intakes, EVI reduction compliance
technology costs were estimated on a per-intake basis using data from the model
facilities' DQs in the cost tool. Other input data were derived primarily from the
information used to develop the Phase II cost modules. As much as possible, EPA used
similar input data and cost calculation methodologies as were used in the 2004 Phase II
rule in developing the estimated compliance costs for assigned compliance technology
modules.
Using the model facility's input data, the cost tool assigns a compliance intake
technology to each facility (or intake). A detailed discussion of how the cost tool makes
technology assignments is provided below. EPA notes that the assigned technology for
each model facility intake in the final rule may be different than that assigned for the
144 Facilities were sent either a DQ or an abbreviated short technical questionnaire (STQ). The STQ
requested much less detailed information about the facility, its CWIS, and its operations. Of the
approximately 1,200 surveys that EPA sent to electric generators, approximately 62 percent were STQs. All
surveys sent to manufacturers were DQ surveys. For more information, see DCN 3-3077 (Statistical
Summary for the Cooling Water Intake Structure Surveys).
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2004 Phase II Rule, because EPA made a number of revisions to the cost tool.145 Through
the cost tool, EPA also accounts for any model facilities that have already installed
technologies that meet the performance requirements in the final rule.146 These facilities
are assigned no compliance costs.
The cost tool output includes capital costs, O&M costs, pilot study costs, and the duration
of facility downtime.
8.2.1 Selection of Technology to Address IM
Since the 2004 Phase II rule, EPA has revised and simplified the method for selecting EVI
reduction compliance technology. The EVI technology used for estimating compliance
cost was selected for each facility intake based on criteria such as existing through-screen
velocity, presence of traveling screens, intake location, water depth, and total intake flow.
Since the compliance standard is based on the performance of modified Ristroph
traveling screens or on a through-screen velocity of 0.5 fps, for the purpose of estimating
compliance technology costs, EPA limited the applied technology options to the
following:
• Replacement of existing traveling screen(s) with (coarse-mesh) modified Ristroph
traveling screen(s) with fish return
• Installation of near-shore coarse-mesh wedgewire screen(s) with a design
through-screen velocity of 0.5 fps
• Installation of larger intake with modified Ristroph traveling screen(s) with a
design through-screen velocity of 0.5 fps
• Installation of variable speed cooling water pumps for intakes with screen
velocities close to 0.5 fps.
• Installation of fish barrier net(s) in addition to traveling screen(s) in certain
marine environments.
The application of Ristroph screens is consistent with the levels of performance used to
calculate the performance standard for EVI. The Ristroph screen technology costs are
based on the replacement/upgrade of existing traveling screens and, therefore, are only
applied to intakes that currently employ traveling screens147. The other technologies
(coarse mesh wedgewire and larger intakes) were not included in the calculations for the
performance standard, but by design are capable of consistently meeting the alternative
standard for intake velocity. Barrier nets are intended to provide additional protection
with regard to impingement.
145 Revisions included adding more flexibility in assigning technology modules and revising some modules
to reflect EPA's final regulatory framework.
146 For example, a facility might already employ closed-cycle cooling or a technology that EPA deemed
would meet the performance requirements.
147 Under Phase III and at proposal, the application of this technology was not limited to intakes with
existing traveling screens and was revised for the final rule due to the fact that the cost module does not
include costs for modifications to the intake to accommodate traveling screens where none already exists.
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At proposal, EPA applied velocity caps to certain existing submerged offshore intakes
and, based on the Phase II record, assumed they would be compliant. Performance data
showed that velocity caps alone did not consistently achieve a level of performance
comparable to BTA. The performance of newly installed velocity caps would be highly
dependent on location and other site-specific conditions, and therefore EPA did not
assign velocity caps as a compliance technology.
8.2.2 EPA's Cost Tool
For the Phase III rule, EPA developed a cost tool to model the general methodology used
in developing the compliance costs in the 2004 Phase II rule. For the final rule, this cost
tool was further modified to mimic the 2004 Phase II rule cost methodology as much as
possible, as well as to increase its versatility. The modified cost tool used for the final
rule costs each intake structure independently, which could result in somewhat higher
costs; facilities installing a technology at multiple intake structures would likely realize
some economies of scale or other cost reductions. Also, while the cost tool accounts for
existing intake technology that individually would meet the impingement mortality
standard, technologies employed that provide partial reduction or may currently meet the
standard when evaluated in combination are not accounted for. Since the final rule allows
for facilities to take credit for the combined effect of multiple technologies, these costs
estimate may result in an overestimation on costs since those already proving partial
reductions may require a less costly technology than was assigned by EPA. For example,
and existing intake may require only a fish barrier net, fish avoidance technology, or an
upgrade to the intake screens to meet the standards rather than completely replacing the
existing traveling screens.
The cost tool was used to develop costs for both power plants and manufacturers. The
following modifications were made to the Phase III cost tool:
• The methodology for assigning compliance technology cost modules was
modified (see below for more details).
• A model input value for Selected Technology Module was added to allow the user
to specify which cost module(s) are applied.
• A model input value for Selected Engineering News-Record (ENR) Construction
Cost Index (CCI) was added to allow the user to adjust costs for inflation.
• A model input value for Regional Cost Factor was added to allow specific
regional cost factors to be used. Default values are average values for the state.
• Model inputs values for Total Plant Design Intake Design Flow and Total Plant
Average Intake Flow were added to facilitate technology selection.
• Cost Modules 10, 10.1, and 10.2 were created to represent the costs for adding
fish barrier nets (Module 5) to Modules 2, 2a, and 3 (combinations of fine mesh
traveling screens and expanded intake structures). (See Exhibit 8-1 for a
description of each module.)
• The same waterbody-specific default distances offshore were applied for
relocating intakes to submerged offshore for all types of intake locations.
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• The technology service life was added to the output.
• The input page was revised to allow selection of the Module 3 compliance screen
velocity.
• An existing impingement technology code was added for wedgewire screens.
• The cost modules for new larger intakes (Module 3) and wedgewire screens
(Modules 4, 7, and 9) were based on a design including fine mesh screens.
However, compliance with the IM reduction technology requirements requires
only coarse mesh. As a result, Module 3 was modified so that the traveling
screens were sized based on a through-screen velocity of 0.5 fps and coarse
(3/8-in) mesh instead of fine mesh screens. The cost for wedgewire screens,
however, was not modified. Since smaller mesh sizes require larger screens due to
the lower percent open area, the associated capital costs for Modules 4, 7 and 9
represent a conservative overestimate. Module 1 (replacing existing screens with
modified Ristroph traveling screens and adding a fish return) always assumed use
of coarse mesh and did not change.
• The capital costs for Ristroph traveling screens and fish returns (Module 1) was
increased and a high cost traveling screen component was added to be applied
under specific conditions.
A cost module for upgrading the existing once-through cooling water pumps from fixed
speed to variable speed (Module 15) was added. A very important modification of the
cost tool was the change to the methodology for selecting the compliance cost module for
each model facility/intake. As noted above, facilities/intakes determined to already be in
compliance were assigned no compliance technology costs. The methodology used to
determine which facilities already met the compliance requirements is described below.
All model facility intake structures determined to not be in compliance were assigned
technology compliance modules as described below.
The addition of barrier nets to some technologies (e.g., Modules 10, 10.1, and 10.2)
involved simply calculating the sum of the individual component cost modules. Because
each cost module has a different O&M fixed factor, the fixed factor used in the combined
modules was calculated as a weighted average using the gross compliance O&M for each
component.
8.2.2.1 Compliance Technology Selection
Exhibit 8-1 presents a decision flow chart that shows how the IM compliance cost
modules were assigned to each facility/intake structure by the cost tool. Exhibit 8-2
presents a decision flow chart that shows how the technology costs modules were
assigned to each facility/intake structure by the cost tool. The subsequent text describes
the decision points in the flowcharts (e.g., screen velocity) and other assumptions.
Intakes determined to already be compliant with impingement mortality standards are not
assigned technology upgrade costs. Details regarding the method for making this
determination are provided in Section 8.2.3.
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Chapters: Costing Methodology
Exhibit 8-1. Flow Chart for Determining Impingement Mortality Compliant Intakes
Based on Meeting Performance of Modified Ristroph Traveling Screens
Closed-cycle
Cooling System?
NO
Intake Velocity
<0.5 fps?
NO
Modified Ristroph
Traveling
Screens?
NO
Velocity Cap?
NO
Continued on
Exhibit 8-2
YES
No Upgrade
Required
YES
No Upgrade
Required
YES
No Upgrade
Required
YES
Velocity Cap
IM Compliant?
NO
Module 15
(Variable
Speed Pumps)
YES
No Upgrade
Required
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Chapters: Costing Methodology
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 8-2. Flow Chart for Assigning Technology Cost Modules Based on Meeting
Performance of Modified Ristroph Traveling Screens
From Exhibit 8-1
NO
Existing
Velocity L
0.61
NO ,
Existing Trav
and Velocity
3.0 f
NO
1
Plant Design
<10mgdor
at Intake
NO
i
[
Screen YES
ps?
;
[ 1 YES
eling Screen
3S?1
Intake Flow YES
Afator Ropth ^_^_
>20 ft?
r
1 Reported velocity is adjusted to reflect
maximum reported flow or adjusted flow i
closed-cycle retrofit for Closed-cycle Opti
2 Add high cost fish return if intake is
submerged offshore >500 ft or intake has
canal length >5,000 ft.
3 Larger intakes are sized using design s<
velocity of 0.5 fps and 9.5 mm screen me
Site Conditions
Suggest Difficult or YES
Pn^tlv Fkh RAtiirn72 •-
Mn T ^
Cost Module Legend
Waterbodv Assianed Module
All 15
Same as Below with High Cost Fish
Return
Waterbody Assigned Module
Ocean 10.3
Estuary/Tidal River 10.3
Great Lakes 1
Freshwater Rivers 1
Lake/Reservoir 1
Waterbodv Assianed Module
Ocean 10.23
Estuary/Tidal River 4
Great Lakes 4
Freshwater Rivers 4
Lake/Reservoir 32
Waterbodv Assianed Module
Ocean 10.23
Estuary/Tidal River 10.23
Great Lakes 3**
Freshwater Rivers 3**
Lake/Reservoir 3**
Module Technology Description
ifter
on. 1 Add Fish Handling and Return System (includes screen replacement)
3 Add New Larger Intake Structure with Fish Handling and Return
4 Relocate Intake to Submerged Near-shore (20 M) with passive wedgewire screen.
5 Add Fish Barrier Net
10.2 Module 3 plus Module 5
10.3 Module 1 plus Module 5
;reen 1 5 Variable Speed Cooling Water Pumps
sh.
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§ 316(b) Existing Facilities Final Rule -TDD Chapters: Costing Methodology
The determination of whether an intake with velocity a cap where the inlet velocity is
greater than 0.5 fps is EVI compliant would require consideration of site-specific
conditions. EPA determined that existing velocity caps located at least 800 ft from shore
met the impingement mortality standard and thus were determined to be already
compliant (see Section 8.2.3). The few that were not determined to be compliant for other
reasons were assigned variable speed pumps (module 15). This is based on the
assumption that the presence of velocity caps already provides a partial reduction and that
the addition of variable speed pumps would provide the incremental reduction necessary
for full compliance.
EPA concluded that facilities would chose to comply with EVI requirements by way of the
velocity standard wherever possible. The installation of variable speed pumps is an
available option for intakes with fixed speed cooling water pumps that currently operate
at flow rates that produce screen velocities slightly higher than the 0.5 fps standard. This
technology option was selected for intakes that reported intake velocities close to but did
not already meet the 0.5 fps standard. A threshold of 0.6 fps was selected for this
technology option because it would result in a flow reduction of 17 percent or less which
should be attainable by variable speed pumps under many circumstances. Since many
intakes already operate at flow rates well under the design intake flow rates, this
threshold was applied to the estimated actual screen velocity based on the "maximum
1 AR
reported intake flow rate" (new design intake flow) rather than the design intake flow
Non-EVI compliant intakes with traveling screens and an acceptable screen velocity are
assigned upgraded modified Ristroph traveling screens with fish returns (Modules 1 and
10.3). Intakes with high screen velocities (greater than 3.0 fps) are assumed to be unable
to meet EVI requirement with Ristroph traveling screens alone and are assigned either new
larger intakes or wedgewire screens.149 The estimated actual screen velocity based on the
"maximum reported intake flow rate" was used as the basis for this decision.
Recognizing that fish returns may be very costly to install at certain intakes, but lacking
detailed data upon which to base decisions regarding costs offish returns at specific
locations, a small subset of intake assigned upgraded modified Ristroph traveling screens
(about 3-4 percent) were assigned additional high-cost fish return capital cost
components. Rather than randomly assigning these costs, intakes with very long intake
canals (greater than 5,000 ft) and those with intakes submerged far offshore (greater than
500 ft) were selected as indicative of difficult and expensive installations. See Section
8.2.2 below for further discussion.
Intakes that are assumed to be unable to meet the IM requirements through the velocity
requirements or with the use of Ristroph traveling screens alone and are assigned either
new larger intakes or wedgewire screens based on total plant DEF, intake water depth,
and/or waterbody type. Intakes at plants where the total plant DEF is less than 10 mgd or
water depth greater than 20 ft and do not withdraw water from oceans or lakes/reservoirs
148 Screen velocities reported in the technical surveys are based on the design flow. Intakes that operate at
lower flow rates will have proportionally lower screen velocities if flow is distributed across all screen
surfaces. The installation of variable speed pumps should allow for the distribution of the reduced flow.
149 This threshold value was revised from 2.5 fps at proposal to 3.0 fps in the final rule. See discussion for
cost tool input 31.
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Chapters: Costing Methodology
§ 316(b) Existing Facilities Final Rule - TDD
are considered good candidates for submerged nearshore traveling screens and are
assigned module 4. All other intakes are assigned new larger intakes. EPA recognizes
that these technologies may not be the least cost, ideal, or most appropriate in each
circumstance. However, these technologies, especially larger intakes, represent the most
costly of the suite of technologies considered by EPA and therefore the costs are expected
to be equal to or greater than the costs of the technology that may ultimately be selected
by a facility. Exhibit 8-3 presents the number of model intakes assigned each technology
module. These values are weighted totals.
Capital and O&M Costs
The modified cost tool provides individual facility/intake cost values for capital costs,
fixed and variable O&M costs (baseline, gross, and net), estimated net construction
downtime, and technology service life. The cost tool provides an inflation cost
adjustment from the year 2002 dollars which were the basis for the 2004 Phase II rule.
The data presented in this chapter are adjusted using the ENR CCI. Cost data presented
are adjusted for inflation using the February 2009 ENR CCI (8532.75).
Exhibit 8-3. Number of Model Facility Intakes Assigned Each Compliance Module
Module
ID
0
1
3
4
5
10.2
10.3
15
Description
No Upgrade Required
Add Modified Traveling Screen with Fish
Handling and Return System (includes
screen replacement)
Add New Larger Intake Structure with Fish
Handling and Return
Relocate Intake to Submerged Near-shore
(20 M) with passive wedgewire screen.
Add Fish Barrier Net Only**
Module 3 plus Module 5
Module 1 plus Module 5
Variable Speed Cooling Water Pumps
Total
Generator
316
295
26
9
0
19
73
30
768
Manufacturer
254
164
108
45
0
10
19
50
650
All
570
459
134
53
0
29
92
80
1417
Note: All values are weighted totals and exclude baseline closures
** Shown to enable comparison to proposed rule where barrier nets were required for shellfish.
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§ 316(b) Existing Facilities Final Rule -TDD Chapters: Costing Methodology
Pilot Study Costs
Pilot study costs were estimated in a similar manner as was done for the 2004 Phase II
rule. Each technology is assigned a pilot study cost factor of either 0 or 0.1. The capital
cost is multiplied by the pilot study cost factor to derive the estimated pilot study cost for
the facility/intake. 15° A minimum pilot study cost of $150,000 in 2002 dollars was
assigned if the calculated pilot study cost in 2002 dollars was lower than the minimum.
For facilities with multiple intakes assigned the same technology, it was assumed that a
pilot study would be performed at only one of the intakes and thus the highest individual
intake pilot study cost was assigned to the facility.
For the final rule, few facilities were assigned pilot study costs. As described above, the
process for assigning compliance technologies led many facilities to be projected to
install Ristroph screens. This is a well-developed technology and typically does not
require a pilot study. Note a pilot study is different from a technology optimization study,
which was costed in the final analysis.Facilities that were projected to install Cost
Module 4 (relocate the intake to an offshore location with a fine mesh passive screen)
were assigned pilot study costs, as this is a significant shift in operations and may be
well-served by conducting a pilot study.
Construction Downtime
Construction downtime estimates are based on the estimated total downtime defined for
each technology cost module in the 2004 Phase II Technical Development Document. It
is assumed that the construction downtime will be scheduled to coincide with the
normally scheduled facility maintenance downtime. Net downtime values for generators
are equal to the total estimated downtime minus the estimated average duration of the
normally scheduled maintenance downtime period of 4 weeks.
The 2004 Phase II and Phase III downtime estimates generally focused on facilities with
large intake flows, with the Phase II estimates being for facilities with DIP greater than
50 mgd. For manufacturers, these values were then adjusted downward based on
structural, process, and operational differences but not necessarily size. Similarly, a
design flow in the 2 to 10 mgd range would tend to involve smaller structures with pipes
in the 10-in to 22-in diameter range, rather than the 4-ft to 6-ft or more range for the
larger systems. Thus, the scope of these intake construction projects is much smaller and
the duration of each task should be correspondingly smaller as well. Accordingly, the net
construction downtime for wedgewire screens for design flows of 2 to 10 mgd was
assumed to be 3 weeks based on BPJ. Exhibit 8-4 presents the downtime estimates used
for the assigned compliance technology cost modules.
150 Typically, facilities with calculated capital costs below $500,000 (in 2002 dollars) are not assigned pilot
study costs, because EPA assumes that facilities incurring smaller capital costs were unlikely to conduct a
pilot study.
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§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 8-4. Net Construction Downtime for Impingement Mortality Compliance
Technologies
Cost
Module
Number1
1
3
4
5
8
10.2
(3&5)
10.3
(1 &5)
15
Power Generators (Weeks)
Flow<
6,944
gpm
0
2
3
0
0
0
0
0
Flow
6,944 to
400,000
gpm
0
2
9
0
0
2
0
0
Flow
400,000
to
800,000
gpm
0
3
10
0
0
3
0
0
Flow>
800,000
gpm
0
4
11
0
0
4
0
0
Manufacturers (Weeks)
Flow<
6,944
gpm
0
0
3
0
0
0
0
0
Flow
6,944 to
400,000
gpm
0
0
7
0
0
0
0
0
Flow
400,000
to
800,000
gpm
0
1
8
0
0
1
0
0
Flow>
800,000
gpm
0
2
9
0
0
2
0
0
1See Exhibit 8-1 for key to module numbers.
8.2.2.2 Changes to Cost Module Costs
Traveling Screen Costs
The cost modules for modified traveling screens were developed for the Phase II Rule
and are described as including costs for the following components:
• Spray systems
• Fish trough
• Housings and transitions
• Continuous operating features
• Drive unit
• Frame seals
• Engineering
• Freshwater versus saltwater environments
The capital costs derived from vendor supplied costs in 2002 also included a separate
installation cost component. Since the engineering and contractor overhead costs were
included in the equipment costs and these costs were higher than the inflation adjusted
equipment costs derived for the Phase I Rule 2, EPA did not include any other indirect
costs. However, these costs are based on the assumption that the screen replacement will
not require any substantial modification of the screen house and support structure. A
review of the cost data suggests that these costs represent easier situations and that there
may be additional costs such as electrical/instrumentation and instances where
modification to the screen house and other infrastructure may be necessary. To account
for this the traveling screen capital costs have been increased by adding a
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§ 316(b) Existing Facilities Final Rule -TDD Chapters: Costing Methodology
contingency/allowance component equal to 20 percent. This cost component is applied to
the total capital costs which include the installed traveling screens, installed fish return,
and installed fish return pumps.
The traveling screen costs were derived using a range of different screen sizes including
screens as small as 2 ft wide. Therefore the costs account for the economies of scale for
smaller systems. Since the smallest screen used in the development of the cost curves for
traveling screens was 2 ft wide, the cost tool was revised such that the minimum screen
width that could be assigned was 2 ft.
Fish Return Costs
Fish returns comprise half of the function of the traveling screen technology and their
ability to function properly is just as important as the Ristroph features on the traveling
screen itself. Industry representatives have cited the following site-specific difficulties
that may be encountered:
• Very long return lengths;
• Difficult access to the source water where submerged offshore intakes are used;
• Space constraints in the screen house;
• Obstructions in the path to a suitable release location;
• Interference from debris and debris discharge restrictions; or
• Access to a suitable release location capable of preventing re-impingement or
preventing stress caused by releasing fish into the plant's thermal effluent.
Many of these problems can be resolved with engineering solutions. The Phase II
traveling screen cost modules included costs for a simple 300-ft fish return for all intakes
plus additional costs for a simple return that was equal to the length of the intake canal
for intakes with canals. The 300 ft. length in the Phase II cost module is intended to
account for the need to transport fish to a location far enough away from the intake to
minimize re-impingement. The fish return flume component included an indirect cost
component equal to 30 percent (10 percent each for engineering, allowance, and
sitework). The traveling screen costs obtained from the vendors stated that it included the
fish return flume but it was not clear what this included. As such, the cost module
assumed that the flume started at the exit from the building. The costs of a fish return will
vary with the degree of difficulty which will range from the low difficulty return design
which is likely already included in the cost estimates to a more difficult return that may
require engineering solutions associated with some of the potential problems described
above. Since the average facility intake will include both easy and difficult return
systems, the applied costs should fall somewhere in between the extremes.
The traveling screen modules also included costs fish return costs for the flume spray
water pumps which included the installed cost of properly sized pumps plus 10 percent
for allowance and 20 percent for intake modifications. Pump engineering costs were
already included. As with traveling screens these costs do not appear to include necessary
electrical or instrumentation components which may add 10 percent to 20 percent to the
equipment costs.
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Chapters: Costing Methodology § 316(b) Existing Facilities Final Rule - TDD
The addition of the 20 percent contingency/allowance factor to the total traveling screen
capital cost applies to the fish return system components as well and accounts for some of
the added costs but since a new fish return requires construction of a new structure and
not just the replacement and modification of existing equipment, EPA concluded that an
additional cost adjustment was warranted.
Since site-specific conditions are unique at each intake location EPA decided to take a
conservative approach to account for the range of difficulties that may be encountered.
This approach involved adding an additional component equal to 100 percent of the fish
return components already embedded in the traveling screen cost modules
This fish return cost increase component is derived using the following equation derived
from costs data presented in Table 2-6 of the Phase 2 TDD:
Fish Return System Cost Increase (in 2002 Dollars) = -3.1538*W2 + 1407*W +24303
Where: "W" = total calculated traveling screen width in feet.
Difficult Fish Returns
EPA decided to include costs for a subset of intakes where site-specific conditions
warrant even greater fish return system costs than those covered by the 100 percent
increase in the return system costs. Two intake attributes that are identified as being more
likely to be associated with conditions that would present greater engineering challenges
and costs are those with remote inlet locations such as longer intake canals and intake
submerged far offshore.
The design for the added length for intakes with canals assumes piling lengths of 15 ft. is
on the low side and should be doubled for these longer returns. Also the indirect cost
component of 30 percent of equipment costs is low and has been increased to 50 percent
to account for transitions and other components. The result of these modifications is an
increase in the cost per foot added length by a factor of 50 percent. Those intakes with
very long canals however, may incur additional costs due to the possible need for fish
pumps to provide sufficient gradient and/or increased costs for structural support beyond
that described above.
Facilities with submerged offshore intakes, particularly those where the intake may have
been built by tunneling to the offshore location, may have screen/pump houses that are
located away from the waterbody. The screen and pump houses of cooling water systems
that are originally built with submerged offshore do not need to be located directly
adjacent to the source water or intake channel. In fact, location the screen and pump
house some distance from the shoreline may be advantageous since the structure can be
set in a location more protected from flooding and storm events. Because of this there is a
greater likelihood that obstructions may be present in the most direct pathway from the
screen house to a suitable fish return release locations. Thus, such intakes may require
longer fish returns that may need to cross an obstruction (e.g., a roadway or public
beach). Intakes submerged relatively short distances offshore are likely to have screen
houses that are close to the shore as well. A review of the physical layout of several
power plants with submerged offshore intakes suggest that a typical distance from the
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§ 316(b) Existing Facilities Final Rule -TDD Chapters: Costing Methodology
shore to the intake screens would be about 500 ft. For the purpose of assigning additional
costs, those intakes with submerged intakes greater than 500 ft. offshore are assumed to
incur additional costs equal to the combined cost for initial fish return flume (300 ft.) and
spray water pump component.
The longest existing fish return identified by EPA is the 4,600 ft. return at the Brunswick
Plant in North Carolina. This return transports fish from the elevated screen house deck
along the shore of the intake canal to the discharge location using gravity alone. EPA
assumes this is representative of an unusually lengthy fish return. For the purpose of
assigning additional costs, those intakes with canals longer than 5,000 feet were assumed
to incur additional costs equal to the combined cost for initial fish return flume (300 ft.)
and spray water pump component.
Summary of Fish Return Cost Adjustments
• All fish return costs including those described below are increased by 20 percent
to provide an additional contingency/allowance component;
• Combined cost for fish return flume (300 ft.) and spray water pumps was
increased by a factor of 100 percent to account for a wider range of site-specific
conditions and difficult and to account for electrical and instrumentation costs;
• The per foot cost of added fish return associated with intakes with canals was
increased by a factor of 50 percent;
• An additional cost component equal to 100 percent of the initial combined cost
for fish return flume (300 ft.) and spray water pumps was added to the costs of
intakes with very long canal and intakes submerged far offshore to account for the
added technology costs associated with solutions such as fish pumps, longer
returns, and obstructions
Variable Speed Pump Costs
Cost module 15 for replacing existing fixed speed cooling water pumps with variable
speed pumps was added as a compliance option. This module involves installing variable
frequency drives for all cooling water pumps at an intake. In some cases, the pump
motors and pumps may need replacement as well. Capital costs are estimated using cost
factor of $15/gpm (in 2009 dollars). This value is based on the median unit value ($/gpm)
of the total costs for several actual and estimated projects. For more details, see the
Variable Speed Pump Memo (2012 update). For systems smaller than 10,000 gpm, a
minimum cost of $150,000 was assigned. Net O&M costs are assumed to be zero due to
the fact that the only new O&M requirements will be for maintenance of the variable
frequency drives while O&M for the pumps may actually be reduced due to lower start-
up stress on pumps and motors. Energy savings from reduced pumping energy
requirements will likely more than offset any energy penalty since the module is applied
only to intakes where the required flow reduction is low. The module is applied to intakes
where flow reduction needed to meet the velocity requirement is estimated to be less than
20 percent. Thus, only capital costs are applied as part of this module. Service life is
estimated to be 20 yrs.
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Chapters: Costing Methodology § 316(b) Existing Facilities Final Rule - TDD
New Larger Intake
The design through-screen velocity has been changed from 1.0 fps used at Proposal to 0.5
fps so that the new intake will be compliant with IM requirements based on velocity
alone. As a result, the intake will not be required to include a fish handling and return
system or the full suite of modified Ristroph traveling screen features. Therefore, the
additional cost components for fish returns associated with traveling screen upgrades are
not included in this cost module. The cost for the 300 ft simple fish return embedded in
the traveling screen component is still included.
8.2.3 Identifying Intakes That Are Already Compliant With
Impingement Mortality Requirements
Existing intakes that were considered to be EVI compliant included those that:
• Employed modified Ristroph Traveling screens or equivalent151 with a fish return
• Employed a closed-cycle cooling system for all cooling water
• Reported a through-screen or through-technology velocity of < 0.5 fps
• Employed existing velocity caps with an intake located greater than or equal to
800 ft submerged offshore
• Employed wedgewire screens with a through-screen velocity of < 0.5 fps.152
• Intakes located in the State of New York
Intakes located in the coastal region of California Data from the 2000 DQ survey were
used to determine intake compliance. Velocity caps were not assumed to be EVI compliant
unless the inlet velocity was < 0.5 fps or the location was >800 ft submerged offshore.
EPA excluded Electric Generators located in the State of New York and those in
California that use coastal and estuarine waters for power plant cooling. These facilities
are already required by the States of New York and California to comply with standards
at least as stringent as the final rule and thus are not expected to incur any compliance
technology costs.
8.2.4 Development of Cost Tool Input Data
This section describes the development of the data input file for calculating technology
upgrade compliance costs using the modified version of the Phase III cost tool. Where
available, the same data used to develop the compliance technology upgrade costs for the
2004 Phase II rule were used as the basis for this effort. It is important to note that, in the
2004 Phase II rule, separate costs were derived for different CWISs at the same facility
where such detailed data were reported. Such data was available for facilities that
151 Traveling screens were considered as equivalent to modified Ristroph if the survey reported use of a fish
return, fish buckets, and low pressure spray, regardless of whether they were specifically identified as
Ristroph in the survey.
152 If wedgewire screen velocity data was not reported, the wedgewire screens were assumed to be
compliant; EPA's experience has been that wedgewire screens are typically designed with a through-screen
velocity of 0.5 fps.
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§ 316(b) Existing Facilities Final Rule -TDD
Chapters: Costing Methodology
completed the DQ surveys. The use of multiple CWISs for costing has been retained in
the final rule. Therefore, for the DQ survey facilities, multiple intakes were included in
the cost data input list, and separate costs were derived for each intake structure. For
power generation facilities, separate cost estimates were derived for 406 intakes at 284
facilities. For manufacturers, separate cost estimates were derived for 317 intakes at 235
facilities.
Data Sources and Assumptions
Exhibit 8-5 below describes the source data and assumptions used in deriving the data
value for each cost tool input variable.153 Data from the DQ surveys is generally denoted
as being derived from Question Qxx, which corresponds to the question on the survey
instrument.154 The assumptions and analysis of several inputs are more complex than the
others and are further discussed immediately following the table. Exhibit 8-5 includes a
list of all input parameters evaluated and includes some that were not deemed appropriate
for use in the final rule.
Exhibit 8-5. Input Data Sources and Assumptions
Input #
1
2
3
4
5
6
7
8
9
Description
Facility type
Cooling system type
State
Waterbody type
Fuel type
Capacity utilization percent
Input (intake) location
Distance offshore, ft
Canal length, ft
Assumptions/Discussion
All power generation facility/intakes are assigned Code 2 and
manufacturers are assigned Code 3.
Based on response to DQ question Q1d. Assigned Code 1 (Full
Recirculation) if the only items checked are recirculating cooling systems.
System consisting of recirculating impoundments were assigned Code 2.
All else Code 0.
Data from Phase II and III Master.*
Data from Phase II and III Master. Data was compared to survey data.
Three facilities had portions of multiple intakes reassigned due to
different waterbody types for different intakes.
Data from 2004 Phase II costing and confirmed with survey database.
Primarily used to distinguish nuclear from non-nuclear facilities. Field not
applicable to manufacturers.
Steam Capacity Utilization Rate (CUR) from Phase II Master with
updates for facilities previously assigned CUR of 0 and with missing
values. Updates are based on year 1999 EIA data. Field not applicable to
manufacturers.
Coded using survey data. If multiple intake types were reported, then
assigned codes using the following hierarchy: Submerged Offshore
(Codes 4 or 5); Intake Canal; Embayment Bay, or Cove; Shoreline Intake
(Codes 1 or 6). Two facilities did not report intake type and were
assigned Shoreline Intake (Code 1).
Used survey data for DQ facilities with data in survey. Cost tool will
assign defaults on the basis of the waterbody type if the survey value is
zero or blank.
Used survey data for DQ facilities with data in survey. Cost tool will
assign defaults on the basis of the waterbody type if the survey value is
zero or blank.
1 See DCN 12-6651 for a blank cost tool with the input page.
' See http://water.epa.gOv/lawsregs/lawsguidance/cwa/316b/index.cfm for blank copies of the surveys.
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§ 316(b) Existing Facilities Final Rule - TDD
Input #
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
Description
Waterbody use/ navigation
Mean intake depth, ft
Intake well depth, ft
Exceeds 5 percent mean
annual stream flow
(1=Yes)
Design intake flow, gpm
New design intake flow,
gpm
Average intake flow, gpm
Design screen velocity
(fps)
Through-screen velocity
flow basis
Water type
(1=marine, 0=fresh)
Debris loading
(1=high, 0 = typical)
Impingement tech in-place
Qualified impingement?
Entrainment tech in-place
Qualified entrainment?
Avg annual Generation
MWh (95-99)
Selected technology
module
Regional Cost Factor
Construction Cost Index
Compliance Screen Mesh
(mm)
Screen Velocity for Module
3 (fps)
Maximum Acceptable
Screen Velocity (fps)
Total Plant Design Intake
Flow(mgd)
Assumptions/Discussion
This field was not used for the final rule.
Used data from 2004 Phase II Rule and Phase III Rule cost development
spreadsheets and survey data. Default value is 1 8 ft for power
generators and 19 ft for manufacturers.
See detailed description below.
This field was not used for the final rule.
DIP data taken from Phase II and III Master. For facilities with multiple
intakes, individual intake flow was obtained from survey database.
Confirmed that sum was equal to total in Phase II and III Master.
Used to estimate costs for Modules 3, 4, 7, 12, and 14. Set equal to
maximum reported intake flow in DQ Question 25. Set equal to reduced
intake flow if Closed-cycle cooling technology is applied.
Average Intake Flow (AIF) data taken from Phase II and III Master. For
facilities with multiple intakes, individual intake flow was taken from
survey database. Confirmed that sum was equal to total in Phase II and
III Master.
Values taken from 2004 Phase II Rule and Phase II Rule cost
development spreadsheet and survey data. Default value is 1.5 fps for
power generators and 1.2 fps for manufacturers.
Survey requested design through-screen velocity. Therefore, Code 1
(Existing Equipment Design Intake Flow) was assigned to all.
Code assigned according to waterbody type. Assumed Ocean and
Estuary/Tidal River are marine. All others are fresh.
Values taken from 2004 Phase II and Phase III Rule costing. Blanks in
spreadsheet were not assigned codes.
See detailed description below.
See detailed description below.
This field was not used for the final rule.
This field was not used for the final rule.
This field was not used in the final rule.
This field is used for specifying a compliance module for which costs are
desired; if filled in, it will override the cost tool technology assignment.
Factors were developed from ENR data for Phase II. Default values
based on Statewide averages are applied to Phase III intakes
ENR Construction Cost Index can be selected to adjust costs for inflation
Selected screen mesh size determining screen percent open area and
screen size for module 3. Coarse mesh (9.5 mm) was assumed.
Design screen velocity can be selected for module 3. A design velocity of
0.5 fps was assumed.
Ristroph traveling screen upgrades (Modules 1 and 10.3 are not
available for existing traveling screens with velocities greater than the
selected value. A value of 3.0 fps was assumed.
Used for technology module selections based on total plant design intake
flow.
The Phase II and III Master files are confidential business information (CBI) files containing the most recent information
for data fields that have been revised, such as DIP or a facility's being subject to the rule. Other data fields (such as intake
location, facility state, and so on) are unlikely to change and are maintained in the original survey database.
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Screen Well Depth (Input #12)
Compliance modules involving replacement or modifications of existing traveling
screens (including the baseline O&M costs) require a cost input value for the total height
of the traveling screens from the base to the deck, which is referred to as the screen well
depth. This data was not reported in the technical surveys and the previous estimates
were derived using the sum of the distances between top and bottom of the intake
opening and the mean water level, which was not necessarily a correct interpretation of
the data, especially for submerged intakes.
In this revised approach, EPA reviewed available screen well design data including data
from facilities that were visited. Waterbody type appeared to be an important factor, since
screen decks are generally situated at elevations that exceed expected extreme high water
levels and the degree of variation in water levels tends to be similar among similar
waterbody types. The data indicated that the difference between extreme high and mean
water levels tended to be greater for rivers and streams and lower for tidal applications.
Exhibit 8-6 presents the assumed distance from the mean water surface to the screen deck
that was derived from trends in the available data. The estimated screen well depth of
each traveling screen was derived by adding the distances shown in Exhibit 8-6 to the
mean intake water depth (Input #11). The resulting values in most cases resulted in
greater assumed well depths than those that were used to derive the previous compliance
cost estimates for the Phase II and Phase III Rules. This resulted in generally higher cost
estimates for cost modules involving replacement or upgrade of existing traveling screens
and for new larger intakes with traveling screens.
Exhibit 8-6. Assumed Height of Traveling Screen Deck Above Mean Water Level
Waterbody
Ocean
Estuaries/Tidal Rivers
Great Lakes
Rivers and Streams
Lakes/Reservoirs
Assumed Distance from Mean Water
Surface to Screen Deck (ft)
15
15
15
30
20
New Design Intake Flow (Input #15)
Depending on the selected compliance technology, the design flow used to estimate
compliance technology costs was either the design intake flow for each intake (DIP) or
the New Design Intake Flow. The New Design Intake Flow (NDIF) was set equal to the
maximum flow volume that was reported for the years 1996 through 1998 in question 25
of the detailed survey or the DIF if no detailed flow data were reported. This maximum
reported intake flow (MRTF) is assumed to be the maximum flow volume required for
cooling and other purposes. For most intakes, the MRTF is smaller than the DIF because
the reported DIF often included excess pump capacity that is either no longer needed or
serves as backup. When calculating intake technology costs for compliance options that
required closed-cycle cooling, the New Design Intake Flow was calculated by reducing
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the DIP by 93 percent of the non-contact cooling flow volume used to estimate the
closed-cycle cooling system costs.
The DIP was used to estimate IM compliance if the selected compliance technology
involved modification/replacement of the existing intake traveling screens (e.g., replace
existing traveling screens with modified Ristroph traveling screens). The NDIF was used
to estimate EVI compliance if the selected compliance technology could be sized
independently of the existing intake technology (e.g., wedgewire screens or a new
intake).
In the current approach, the cost for Module 5 (barrier net) was developed as a
technology for each separate intake. In the 2004 Phase II rule, the barrier net costs were
developed using the combined flow of multiple intakes at the same facility. This is based
on the assumption that the multiple intakes are close enough together that they can be
protected by a single barrier net.
Impingement Technology In-place (Input # 21)
The following criteria were used to assign impingement technology codes:
• Assigned Code 1 (Traveling Screens) if answered Yes to Q19c Traveling Screen
Codes El, E2, E3, E4, E5, E6, F (Other) if description qualified.
• Assigned Code 5 (Wedgewire Screen) if answered Yes to Q21b Passive Intake
Code G.
• Assigned Code 2 (Passive Intake) if answered Yes to Q21b Passive Intake Codes
H, I, J, K.
• Assigned Code 3 (Barrier Net) if reported Fish Barrier Net Code P in Q22b.
• Assigned Code 4 (Fish Diversion or Avoidance System) if answered Yes to Q22
Fish Diversion or Avoidance System Codes M, N, O, Q, R, S, T, U, V.
Qualified Impingement? (Input # 22)
As described above, some intakes utilize technologies that were considered to already
meet the performance standard for impingement mortality. The following criteria were
used to make this assessment:
• Assigned Code 1 (qualified) if design screen velocity was < 0.5 fps.
• Assigned Code 1 (qualified) if survey indicated there was a combination of
technology components associated with a Ristroph-type, fish-friendly traveling
screen, including a separate fish return trough present. Included only intakes
answering Yes to Q20a (are screens used to reduce impingement and
entrainment?) and reporting several of the following:
o Q20b (I&E Reduction System-Spray Wash/Fish Spray);
o Q20b2 (I&E Reduction System-Fish/Debris Troughs);
o Q20b4 (I&E Reduction System-Fish Buckets/Baskets/Trays);
o Q23b Code W (Fish Pump);
o Q23b Code X (Fish Conveyance Systems);
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o Q23b Code Y Fish Elevators/Lift Baskets);
o Q23b Code AA (Fish Holding Tank);
o Q23b Code BB (Other) provided description qualified.
• Assigned Code 1 (qualified) if there was a qualifying Fish Diversion or
Avoidance System intake technology reported in Q22b including:
o Code M (Velocity Cap) if intake was located far offshore155.
• Assigned Code 1 (qualified) if there was a qualifying Passive Intake System
intake technology reported in Q 21b including:
o Code G (Wedgewire Screen); and
o The design intake velocity of the technology is 0.5 ft/sec or less.
If a technology applied to only a portion of parallel equipment (e.g., Ristroph screens on
only a portion of screens), it was assumed that the lesser qualified technology was present
on all equipment (i.e., the entire intake was designated as not qualified).
Maximum Acceptable Screen Velocity (Input 31)
EPA was concerned that some intakes with traveling screens may include design
parameters that are outside the range typically employed or may have difficulty
employing effective fish returns and therefore may not perform as well as the systems
evaluated by EPA. While EPA expects the required optimization study would ensure
appropriate operating parameters, it is also possible that existing traveling screens may
need other modifications to meet the definition in the rule. EPA decided that a high
through-screen velocity may be an example of such a situation and used a threshold
through-screen velocity of greater than 3.0 fps as a criterion for identifying intakes with
traveling screens under such conditions. EPA recognizes that such traveling screens
(when upgraded) may perform satisfactorily, but to be certain the selected technology
response would meet the performance standards for EVI, EPA select a higher cost
technology options for this subset of model facilities. EPA notes that at proposal this
value was set at 2.5 fps based on recommendations from a technology vendor (see DCN
12-6657). However, a re-evaluation showed that this threshold was more applicable to
fine mesh screens. EPA notes this velocity threshold is significantly higher than the upper
end of the range of values for facilities used in the development of the numeric
impingement standard. EPA increased the proposed value of 2.5 fps to a value of 3.0 fps.
8.3 Entrainment Mortality Compliance Costs
To estimate costs of entrainment mortality (EM) controls using flow reduction, EPA
developed an option that would retrofit facilities with once-through cooling systems to
closed-cycle recirculating systems in the form of mechanical draft wet cooling towers.
Costs were derived for cooling systems associated with individual intakes.
In September 2007, EPA obtained an Excel spreadsheet from EPRI that contained a set of
calculations for estimating cooling tower retrofit costs at existing steam power plants.
155 Only velocity caps with distance offshore greater than 800 ft. See DCN 12-6601
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EPA compared the EPRI model to the methodology used in the Phase IINODA and
found that the two methods produced similar costs. Because these methods produced
similar costs and the EPRI method was simpler and more flexible, the EPRI methodology
was chosen to develop the model facility cost equations for the final rule. In a 2011
technical report "Closed-Cycle Cooling System Retrofit Study - Capital and Performance
Cost Estimates" (Technical Report #1022491), EPRI provided a closed-cycle cost
estimate for electric generators with a design intake flow greater than 50 mgd. The basic
methodology used in this more recent EPRI estimate was similar to the 2007
methodology but included a more detailed approach utilizing site-specific data not
available to EPA. A comparison of the EPRI cost estimate to similar EPA estimates
indicated that the cost methodology EPA adapted from the EPRI 2007 cost methodology
produced comparable results. See TDD Chapter 12 for a more detailed discussion. The
EPRI 2007 methodology distinguishes between three separate capital cost values related
to the degree of difficulty associated with the cooling tower retrofit. The costs are
representative of an easy (lowest cost), average (intermediate cost) or difficult (highest
cost) retrofit. EPA derived model facility capital costs equations for both the average and
difficult retrofit scenarios for use in the applicable cost analyses.156 These different levels
of costs were applied differently to power generators and manufacturers.
EPRI lists the factors that affect the selection of the degree of difficulty rating for capital
costs as:
• Availability of tower space nearby
• Need to remove or demolish existing structures
• Whether the tower site elevation is higher than the existing cooling system intake
bay so cold water can flow by gravity to the intake bay
• Whether there are underground interferences in the path of the new circulating
water lines or at the location of the hot water sump and new circulating water
pumps
• Whether the tower site has overhead interferences, including transmission lines
• Whether the tower design might have to work around excluded areas where
activities that cannot not be moved or blocked occur (e.g., hazardous materials
storage, vehicle turn-around areas, and security areas)
• The degree of construction work needed to convert the existing intake to handle
the lower intake flow volume needed for makeup water
• How difficult it will be to tie the towers in to the existing cooling system
• Whether the site has unfavorable soil or geological conditions
• Whether the site has contamination that might require remediation
156 EPA used the average scenario for the power generator compliance cost scenarios that include closed-
cycle cooling, because the costs were derived from power generation applications and are representative of
costs on a national scale (i.e., some facilities might face a difficult scenario, but others will have an easy
scenario, balancing costs on a national scale). For some IPM analyses, EPA used the difficult scenario
because it represented the highest cost scenario and would provide an indication of worst case economic
impacts. For more information, see the BA.
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EPRI states that there is no simple way to determine how consideration of each of these
items will translate into assigning the project into the easy, average, or difficult
categories. If none of the items presents any obvious problems, an easy retrofit might be
expected. If two or three do, average is probably appropriate. If more than three, then
difficult is appropriate (DCN 10-6930).
EPA's costs for closed-cycle cooling include capital costs, O&M costs including
auxiliary power requirements, heat rate penalty losses, and downtime costs.157 EPA also
included additional costs to account for noise and plume abatement, which will be
required at some sites. Cooling tower costs were derived in a different manner than the
intake technology costs (see below for more information). In the case of the intake
technology costs, technologies were assigned to individual model facilities and the
associated costs were calculated and scaled upward (using survey weights) to determine
the national model facility costs. For the cooling tower costs, preliminary costs for
individual DQ facilities were derived using the EPRI spreadsheet and then aggregated to
generate cost equations representing the national average. The preliminary costs
calculated for each intake using the EPRI calculation worksheet were then adjusted using
the regional cost factor derived for that plant in the 2004 Phase II rule.158 The model
facility costs were then generated using these equations. As in the case of the intake
technology costs, the model facility cooling tower costs were then multiplied by a
weighting factor specific to each facility to obtain national model facility costs.
8.3.1 Capital Costs
Power Generators
Since the EPRI costs were derived from cooling tower retrofit costs for power generation
systems, it is reasonable to select the "average" difficulty costs as the basis for the
compliance costs for cooling towers for power generation cooling systems. It was
assumed that the recirculating flow rate of the cooling tower would be equal to the MRIF
of the existing cooling system. Intake-specific costs were derived for the facilities with
once-through cooling water systems that provided design flow data in the 2000 detailed
surveys. Facilities were included in this portion of the analysis regardless of the capacity
utilization rate (CUR), as this rate does not affect the DIF.
The ratio of capital cost to DIF (dollars/gpm) was then calculated for each plant. Various
methods for using this data to estimate costs were evaluated, including using cost curve
trend lines that varied with flow derived using Excel (which uses a least squares method)
and a linear approach using the between-facility average or median of the dollars/gpm
ratios. So as not to make assumptions that would lead to underestimating costs, EPA
assumed that a simple linear equation using the overall between-facility average of the
individual facility capital cost to DIF ratios (dollars/gpm) represented a reasonable
estimate for the national model facility costs.
157 There are no pilot study costs for cooling towers (i.e., pilot study factor = 0). These technologies are
well studied, and the performance can be predicted using meteorological and other site-specific data.
158 EPRI's cost methodology did not account for facility location. Construction costs do vary regionally, so
EPA applied the regional cost factor.
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EPA also evaluated whether applying the facility weighting factors to the calculation of
the average had any effect on the resulting average ratio of dollars/gpm and found that
the value changed by less than 1 percent. The same was true for the O&M cost
components as well.
EPA also recognizes that some generators are situated in locations that may require
plume and/or noise abatement. It is not clear from the EPRI tower calculation support
documentation whether the mix of retrofit projects from which the "average" difficulty
costs were derived are representative of the universe of facilities that would be required
to install closed-cycle cooling under the final rule. One concern is that the compliance
universe under an option that would require closed-cycle of all facilities will include a
larger proportion of facilities requiring additional costs for requirements such as plume
abatement, noise abatement, and space constraints.
EPA adopted a conservative approach to account for this possibility by modifying the
cost for closed-cycle cooling systems at power generators. An analysis determined that
approximately 25 percent of existing power generators may require additional costs
associated with plume and/or noise abatement and space constraints. (See DCN 10-6671.)
Rather than attempt to assign specific technology upgrade additional costs to specific
facilities,159 EPA spread these added costs throughout the entire universe of facilities that
would be required to undergo closed-cycle cooling retrofits since the existing plant
database did not contain sufficient detailed data to make a reliable determination
regarding which specific facilities would be subject to these requirements. These added
costs were spread across all facilities by adding the equivalent of 25 percent of the
estimated additional costs for plume abatement technology to the cost assessed for all
facilities. The estimated additional costs for plume abatement were considered as
representative of the mix of costs associated with plume abatement, noise abatement,
and/or space constraints. (See DCNs 10-6652 and 10-6653.)
Exhibit 8-7 presents the capital and O&M cooling tower cost formulas for the "average"
difficulty cooling tower retrofit. Exhibit 8-8 presents the adjusted "average" retrofit cost
factors modified to account for 25 percent plume abatement costs. The cost equations in
Exhibit 8-7 were also used to estimate compliance costs for manufacturers where non-
contact cooling water (NCCW) was used primarily for power generation purposes. 16° The
cost equation factors in Exhibit 8-8 were used to estimate costs for power generating
facilities.
159 EPA's concluded that the estimated costs of plume abatement was close to the capital cost of the EPRI
"difficult" scenario and should be representative of the cost of the mix of additional abatement
technologies.
160 The NCCW flow was considered as being primarily for power generation if the answer to question 4a
and 4b in the DQ survey indicated that greater than 85 percent of the cooling water was used for power
generation purposes.
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Chapters: Costing Methodology
Exhibit 8-7. Cooling Tower Costs for Average Difficulty Retrofit
Costs and Generating Output Reduction
Capital Cost (CC)
Fixed O&M Cost (OMF)
Variable O&M - Chemicals (OMC)
Variable O&M - Pump & Fan Power (OMV)
Energy Penalty -Heat Rate (EP) Non-nuclear
Energy Penalty -Heat Rate (EP) Nuclear
Equation
CC = MRIF(gpm) x Constant
OMF = MRIF(gpm) x Constant
OMC= MRIF(gpm) x Constant
OMV= MRIF(gpm) x Constant
EP=MWSa x Constant
EP=MWS x Constant
Constant (2009)
$263
$1.27
$1.25
0.0000237
0.015
0.025
a MWS is the total steam generating capacity in MW.
Exhibit 8-8. Capital and O&M Cost Factors for Average Difficulty Cooling Tower
Retrofit with 25 percent Plume Abatement
Average Retrofit
Add for Plume Abatement
at a Single Facility
Average Increase if
Applied to 25 percent of
Facilities
Adjusted Constant
Capital Cost
(2009 Dollars)
Dollars/gpm
$263
$120
$30
$293
Fixed O&M
(2009 Dollars)
Dollars/gpm
$1.27
$1.00
$0.25
$1.52
Variable O&M -
Chemicals3
(2009 Dollars)
Dollars/gpm
$1.25
$0.00
$0.00
$1.25
Variable O&M -
Pump & Fan
Power
MW/gpm
0.0000237
0.0000031
0.0000008
0.0000245
a Non-power variable O&M costs are for additional treatment chemical for optimized tower operation at higher cycles of
concentration
Manufacturing Facilities
For manufacturing facilities, EPA recognizes that cooling tower retrofits will need to be
integrated into the existing manufacturing processes at different locations within the plant
and it is expected that in many instances difficulties will be encountered to a greater
degree and frequency than at power generators. Such difficulties may involve space
constraints, reconfiguration of process piping, long piping runs, conflicts with existing
piping and infrastructure, and utilities. These are some of the factors that EPRI cited as
contributing to a "difficult" designation for a cooling tower retrofit. In addition, the
cooling towers are likely to be installed as smaller units serving individual processes
throughout the plant, thus reducing the opportunity for savings from economies of scale
that may be achievable at power generators.
As a result of these considerations, EPA applied the "difficult" retrofit capital costs to any
closed-cycle cooling system retrofit at a manufacturer, with the exception of instances
where cooling water was used primarily for power generation purposes, as described
above. In such cases, the "average" difficulty costs shown in Exhibit 8-7 were applied.
Exhibit 8-9 presents the "difficult" retrofit cost equations utilized for estimating closed-
cycle cooling system costs for manufacturing facilities. Like power plants, the costs for
manufacturers are also based on the MRIF; however, as described below, manufacturers
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have some key differences that were incorporated into determining the appropriate flow
for designing a cooling tower system.
Exhibit 8-9. Cooling Tower Costs for Difficult Retrofit
Costs and Generating Output Reduction
Capital Cost (CC)
Fixed O&M Cost (OMF)
Variable O&M - Chemicals (OMC)
Variable O&M - Pump & Fan Power (OMV)
Equation
CC = MRIF(gpm) x Constant
OMF = MRIF(gpm) x Constant
OMC= MRIF(gpm) x Constant
OMV= MRIF(gpm) x Constant
Constant (2009)
$411
$1.27
$1.25
0.0000237
Units
Dollars
Dollars
Dollars
MW
a MWS is the total steam generating capacity in MW.
Intake Flow Used To Estimate Costs
Aside from the difficulty of installation and retrofit, there is generally little difference in
the operation of cooling water intake structures and cooling systems between power
plants and manufacturers. Both types of facilities use cooling water in similar ways.
However, manufacturers have one notable difference—they tend to use more process
water and contact cooling water. This results in opportunities for manufacturers to reuse
process water as cooling water, to use cooling water later in the process, and ultimately to
reduce overall withdraws. The cost analysis does not include the potential for cost
savings due to these reuse opportunities. In many cases, process water is withdrawn via
the same intake structure as cooling water, creating a more complicated water balance
diagram.
161
Cooling water can consist of both non-contact cooling water (NCCW) and process
contact cooling water (CCW). Contact cooling water which comes into direct contact
with process chemicals and materials can pick up contaminants during the cooling
process and may require treatment to remove contaminants if it is to be recirculated
through a cooling tower and reused in the process. In some cases (e.g., certain steel-
making processes), the required treatment process may be minimal (e.g., settling), but in
others, flow reduction is not possible without materially affecting the facility's operations
or products since the water quality requirements for the contact cooling water may render
recirculation of CCW impractical since manufactured product quality and/or process
performance may suffer without costly treatment. For this reason, EPA did not consider
flow reduction using closed-cycle cooling as a readily available technology option for
CCW or combined flows that included CCW or process water that could not be
segregated. Therefore, closed-cycle cooling was only applied to the estimated NCCW
component of the intake flow for manufacturers.
As a result, EPA reviewed a number of flow balance diagrams from the DQ industry
questionnaires for facilities in multiple industrial sectors and developed an estimated
proportion of total intake flow that is dedicated to cooling.
At power generators, the majority of intake water is used as non-contact cooling water for
condensing steam and equipment cooling (service water). Only a small portion is used for
Reuse of cooling water as process water also presents a regulatory challenge, as these flows are no
longer considered cooling water.
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process water or contact cooling. Therefore, for cost estimation purposes, the NCCW
flow was assumed to be the entire intake flow. For power plants that provided intake flow
data in question 25 of the technical survey, the MRIF was used as the cooling tower
design flow. Otherwise, the DIP was used.
For manufacturing facilities, the proportion of intake water used for process, NCCW, and
CCW purposes varied widely between industry types and facilities within each industry.
In order to determine water use trends at manufacturers, EPA examined data reported in
the 2000 detailed technical surveys for the large flow facilities with DIP greater than 100
mgd. The detailed technical survey requested information concerning percent of cooling
water flow used for: 1) electric generation; 2) air conditioning; and 3) contact or non-
contact process cooling. Unfortunately the survey did not distinguish between contact and
non-contact process cooling water, so schematic flow diagrams were also examined since
they often contained additional data concerning flow volumes and specific water uses.
All available data concerning the following items from both the survey responses and the
schematic flow diagrams were then summarized in a database with the following
components:
• Plant ID
• Design intake flow (DIP)
• Maximum reported intake flow (MRIF)
• Average intake flow (AIF)
• Cooling system type
• Industry type
• Non-contact cooling flow (NCCW)
• Non-contact cooling flow used mostly for electricity generation
• Process and/or contact cooling flow
• Answer to survey question 4a or 4b (percent cooling water used for electricity
generation)
• Answer to survey question 3h (estimated percent of design capacity used for
cooling)
• Detailed notes
"Type of cooling water use" and "flow volume" data was available in only a portion of
the schematic diagrams. However, enough data was available to estimate NCCW flow for
four or more facilities that could be categorized into one of the following industrial
groups:
• Chemicals
• Paper
• Petroleum
• Metals
• Other
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With NCCW flow data now available for this subset of facilities, a methodology was
derived to estimate NCCW flows for other facilities in the database. In order to simplify
the approach, it was assumed that the general mix of process water, NCCW, and CCW
use would be somewhat similar within each of these major industry groups.
The NCCW flow for each facility was then compared to available flow data representing
total flow. Three factors based on the total NCCW flow were then evaluated to see if they
would be suitable for estimating the NCCW component at facilities where detailed data
were not available. For each factor, the total NCCW flow value taken from the schematic
diagrams was divided by the total process and cooling flow from the diagrams, the DIP
and the MRIF. Facilities with low NCCW flow values that employed cooling systems
other than once-through or where the total flow (from the flow diagram in the survey)
was much lower than the AIF were not included in the analysis, since the NCCW flow
data for these facilities may not have included the volume of recirculating cooling water.
The remaining ratios were then averaged for all facilities with such data in each industry
group. Exhibit 8-10 presents the results of this analysis.
Exhibit 8-10. Ratio of Non-Contact Cooling Water Flow to Total Facility Flow for
Evaluated Manufacturing Facilities With DIF >100 MGD
Plant Type
Chemicals
Other
Paper
Petroleum
Metals
NCCW
/Diagram
Total (%)
80.2%
96.0%
77.6%
81.6%
83.8%
Number
with Data
5
5
3
4
7
NCCW
/MRIF (%)
70.5%
75.5%
64.0%
82.4%
46.3%
Number
with Data
2
3
1
3
2
NCCW
/DIF (%)
50.2%
65.4%
33.9%
31.6%
53.5%
Number
with Data
5
5
4
4
6
Value
Selected
for
Estimation
70.5%
75.5%
64.0%
82.4%
53.5%
As can be seen from Exhibit 8-10, the trend is for the ratio of "NCCW/Diagram Total" to
be greater than the ratio of "NCCW/MRJF' which is greater than the ratio of "NCCW/
DIF." EPA concluded that the ratios of "NCCW/Diagram Total" were less suitable for
extrapolating to other facilities since the values were on the high side and corresponding
diagram totals would not be available for the majority of facilities that were not
evaluated. The ratio of NCCW/DIF tended to be lower than the ratio of NCCW/MRTF
due to the fact that the MRIF was often lower, since the DIF often included intake
capacity that was seldom, if ever, actually utilized. Therefore, with the exception of the
metals category, the average ratio of NCCW/MRTF was selected as the factor to be used
in estimating NCCW flows using MRIF data. In the case of the metals category, the ratio
of NCCW/DIF was greater and was selected as the factor to be used in estimating NCCW
flows since it was the median of the three values and was based on a larger number of
data points.
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The selected factors were then used to estimate the total NCCW flow for each
manufacturing facility in their respective categories by multiplying the factor times the
MRIF. In cases where MRIF data were not available, the DIP was used which may result
in some overestimation of the NCCW flow volume. For those facilities used to derive
these factors where actual NCCW data were derived from the flow schematics, the actual
NCCW value was used instead.
8.3.2 O&M Costs
The EPRI Tower Calculation Worksheet also produces a general O&M cost on the basis
of the facility's DIP. This cost is assumed to be a fixed O&M cost component consisting
primarily of labor and materials. The general fixed O&M cost was then adjusted using
the regional cost factor. Unlike the O&M costs calculated for intake technologies, the
O&M costs for the baseline intake technology were not deducted (except as noted below
under pumping height) for facilities converting to cooling towers. The use of a closed-
cycle cooling system will still require an intake system for makeup water. Although the
intake volume will be substantially smaller (at least 90 percent less volume), it will
require O&M costs, which are assumed to be more than offset by the existing intake
O&M costs.
The EPRI worksheet also generates an O&M cost associated with pump and fan energy
requirements. This is assumed to be a variable cost component that would vary with the
operation of the generating units. The value derived here is associated with generating
units operating at full capacity. Unlike the fixed O&M cost, this component was not
adjusted using the regional factor because it is expressed in units of power consumption,
which is not dependent on the facility's region.16
As with the capital costs, the fixed O&M to DIP ratio (dollars/gpm) and variable O&M to
DIP ratio (MW/gpm) were calculated. The Excel trend lines for the O&M costs and
power requirements were plotted against DIP, and average and median ratios of costs and
power requirements versus DIP were then compared. As with the capital costs, the
average of the facility ratios of fixed O&M to DIP (dollars/gpm) and variable O&M to
DIP (MW/gpm) represented reasonable estimates for the national model facility costs.
The EPRI worksheet contains numerous assumptions and default values that can be
modified using site-specific data. Specific relevant assumptions and default values are
listed below:
• Tower configuration was in-line rather than back-to-back, meaning towers are
oriented in single rows rather than rows of two towers side by side.
162 The EPRI worksheet can also derive pump and fan energy costs in dollars using heat rate and fuel cost
data, but this feature was not used. The input value for the national economic impacts analysis O&M pump
and fan energy component is the electric energy requirement in MW, not the cost in dollars. The MW value
derived from the equation represents the maximum energy requirement at full-capacity operation and is
expected to be reduced when the plant is operating at less than full capacity.
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• AH1 (Elevation rise from sump level to pump level) was set at 0 ft.163
• AH2 (Elevation rise from pump to tower site) was set at 0 ft.
• AH3 (Height of tower hot water distribution deck) was set at 25 ft.
• Recirculating water pipe flow velocity was set at 8 fps.
• Tower loading rate was 10,000 gpm/cell
The EPRI cost worksheet also assumes that O&M costs are the same for cooling towers
with different retrofit difficulties. Thus, the same O&M costs were applied to all cooling
tower retrofits, regardless of the difficulty of the retrofit. EPA assumed the EPRI O&M
costs were based on current operating methods employed at power generators, which
often involved minimal use of chemical treatment and operation at lower cycles of
concentration. As described below, further adjustments to O&M costs were made for
plume abatement and for optimized operation with regards to flow reduction.
Plume Abatement Costs
Adjustments to O&M for cooling towers with plume abatement technology included an
increase in energy requirements and fixed O&M costs. The increase in energy
requirements was based on an assumed 8 ft increase in pumping head and a 10 percent
increase in fan energy to account for additional demands created by addition of the dry
section coils. The increase in the fixed O&M component was based on an assumed 80
percent increase in O&M costs for the additional maintenance associated with the dry
cooling section equipment. A more detailed discussion can be found in the "Cooling
Tower Noise Abatement and Plume Abatement Costs." (See DCN 10-6652.) These costs
are shown as the cost adjustment factors in Exhibit 8-8 above.
Optimization Costs
EPA found that current practice regarding chemical treatment of circulating water at
power generators mostly involved treatment with biocides such as chlorine, and that there
was often no incentive to optimize (reduce) makeup flows by operating at higher cycles
of concentration. Operating a closed-cycle cooling system at higher makeup and
blowdown volumes results in higher intake flow volumes and lower cycles of
concentration. Lower cycles of concentration generally reduce the need for careful
operational control and chemical treatment for scale formation or suspended solids
deposition. EPA assumed that compliance with the regulatory options for flow reduction
would include the operation of closed-cycle systems in an optimized manner, which may
include operating at higher cycles of concentration.164
163 Although the default values of AH1 and AH2 were 5 ft and 10 ft, respectively (15 ft total), they were set
equal to 0 in EPA's cost estimates to offset a portion of the baseline once-through surface water intake
pumping energy requirement that would no longer be needed (i.e., the facility's intake structure will be
withdrawing less water and will require less energy; these savings were recouped by using different
assumptions for AH1 and AH2).
164 As noted in the preamble, EPA assumed target optimal cycles of concentration of 3.0 and 1.5 for fresh
and marine waters, respectively.
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To account for this, EPA increased the O&M cost estimates derived from the EPRI
model by adding another variable cost component to cover increased use of chemical
treatment. This component included additional costs for both increased chemical
treatment and added labor (see "Water Balance, Flow Reduction, and Optimization of
Recirculating Wet Cooling Towers," DCN 10-6673). Capital costs were not adjusted,
since the estimated cost of flow monitoring and chemical feed systems was very small—
equal to about 0.2 percent of the "average" difficulty retrofit cost. These costs are shown
as the chemical treatment cost component equations and factors in Exhibits 8-7 and 8-9
above.
8.3.3 Energy Penalty
The term "energy penalty" as associated with conversion to closed-cycle cooling has two
components. One is the extra power required to operate cooling tower fans and additional
pumping requirements, referred to as the auxiliary power requirement penalty. The other
is the lost power output due to the reduction in steam turbine efficiency due to an increase
in cooling water temperature, referred to as the turbine efficiency penalty.
Auxiliary Power Requirement
The auxiliary fan and pump energy requirement is included as a separate component in
the O&M costs described above and was applied in all cases. The auxiliary power
requirement was estimated as MW of power required, which was then converted to costs
in the economic model.
Turbine Efficiency Loss
The energy penalty associated with turbine efficiency loss due to the conversion from
once-through to recirculating cooling towers is best expressed as a percentage of power
generation.165 To offset the efficiency loss, a facility can increase its fuel consumption if
the steam boilers are operating below full capacity or it could experience a reduction in
electricity generated if the steam boilers are operating at full capacity and are unable to
increase steam output.
The turbine efficiency penalty is typically expressed as a percentage of power output. In
the Phase I Rule, EPA estimated an annual average energy penalty of 1.7 percent for
nuclear and fossil-fuel plants and 0.4 percent for combined cycle plants. The estimated
maximum summer penalty was 1.9 percent. The EPRI supporting documentation for the
2007 methodology (DCN 10-6930) estimated the energy penalty to range between 1.5
percent and 2.0 percent. In their more recent cost estimate (Technical Report #1022491),
EPRI performed a detailed analysis of turbine design and conditions for seven different
regions that resulted in a time-weighted averages ranging from -0.2 percent to 2.3 percent
for hot days assumed to occur for 10 percent of the year. In the analysis EPRI used a hot
day penalty of 2 percent. The time-weighted annual average ranged from 0.6 percent to
165 Typically, cooling towers do not cool the circulating water to the same temperature as surface water
used in once-through cooling. As a result, the steam is not cooled as effectively leading to a higher steam
turbine backpressure and a loss of generating efficiency.
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1.4 percent. In the analysis EPRI used an annual average of 1.0 percent for the remainder
of the year.
To reflect the differences in steam pressure for facilities using different fuels,166 EPA
distinguished between nuclear and fossil plants. Fossil plants experience a lower turbine
efficiency loss due to the higher system pressures, while nuclear plants would realize a
higher efficiency loss. As a result, EPA selected a turbine efficiency loss value of 1.5
percent for fossil plants and 2.5 percent for nuclear facilities, which given the more recent
EPRI estimates are representative of the upper end of the range of values that can be
expected throughout the nation. These values apply directly to the generation rate of the
steam generating units, and thus the cost will vary with the amount of electricity being
generated. (See "Cooling Tower Energy Penalties" [DCN 10-6670] for a more detailed
discussion.)
For closed-cycle cooling retrofits at manufacturing facilities or intakes that do not
primarily generate electricity, no turbine efficiency energy penalty was assigned since no
power is being generated. For manufacturing power generation systems, the energy
penalty for turbine efficiency loss for non-nuclear power plants (i.e., 1.5 percent) was
applied.
8.3.4 Construction Downtime
Power Generators
In addition to the costs described above, a facility might also incur downtime costs. In the
Phase II NOD A, EPA assumed net construction downtimes of 4 weeks for non-nuclear
plants and 7 months for nuclear plants. These net values assume that the construction tie-
in would be scheduled to coincide with the plant's routine scheduled maintenance event.
Thus, the net value includes a deduction of the estimated maintenance downtime period
(4 weeks for non-nuclear facilities) from the total estimated downtime. EPA asked for
comments in the Phase IINODA regarding these assumptions but then did not make any
conclusions regarding the comments because the cooling tower option was not included
as part of the basis for the 2004 final rule. Therefore, at proposal EPA assumed net
construction downtimes of 4 weeks for non-nuclear plants and 7 months for nuclear
plants.
EPA considered revised downtime estimates for the final rule based on comments and
new data. EPA notes that at the Canadys Station and Jefferies Station sites, the closed-
cycle system hook-up was completed within the scheduled plant outage period. EPA
found that net downtime may be zero, which is further supported by an estimate of zero
net downtime for "easy" to "average" retrofits in a report attached to EPRIs comment to
the proposed rule (Comment 2200 - Technical Report No 1022491). However, the single
value used by EPA represents a national average and thus should be representative of the
full range of downtime values that would occur. The EPRI estimated net downtime
166 Steam turbines at nuclear facilities tend to operate at lower steam temperatures and pressures; therefore
the energy penalty associated with turbine efficiency is expected to be higher for nuclear power facilities
than for fossil-fuel facilities.
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duration ranged from 0 to 6 months depending on difficulty. The weighted average of the
EPRI net downtime estimates which represent the full range of difficulties was 1.5
months (if the much longer estimates for re-optimization are excluded167). Also, EPA has
obtained new data that supports the 2 month total (one moth net) estimate. During the site
visits EPA learned that both the Me Donough and Yates Plants in GA, experienced a tie-
in outage for the cooling tower retrofit of 6-8 weeks (see DCN10-6536 McDonough and
DCN 10-6537 Harllee Branch). These projects would be classified as average to difficult
retrofits. This new information supports EPAs estimate used in the cost analysis of 4
weeks net (8 weeks minus the assumed 4 weeks of scheduled maintenance). Since there
is a limited number of examples to draw from, EPA's estimate falls between the values,
and the new data supports these assumptions, EPA concludes that its estimate is
reasonable. The assumed net downtime for non-nuclear power plants remains 4 weeks.
Upon evaluation of additional data for nuclear facilities, EPA has revised the downtime
estimates for closed-cycle retrofits that reduces the overall downtime estimate. In the
revised approach, facilities are divided into two groups: those that have conducted or are
currently planning to conduct an extended capacity uprate (ECU) and those that have not.
An important characteristic of an ECU is that it involves considerably more construction
activities compared to simple refueling outages (including replacement of portions of the
generating system) and therefore involves outages much longer than those for refueling.
These projects provide an ideal opportunity to further reduce downtime if the closed-
cycle retrofit is performed concurrently. Data regarding ECU scheduling was readily
available. The final rule gives the Director greater flexibility in establishing compliance
schedules for entrainment requirements that would allow for scheduling of the closed-
cycle retrofit to occur concurrently with an ECU. For those facilities where ECUs are
unlikely to occur in the future (i.e., facilities where an ECU has been performed or is
currently planned), EPA took an approach similar proposal but with the duration adjusted
downward to a level consistent with this new information. For the final rule estimate,
EPA evaluated the EPRI net downtime estimate of 6 months used in their cost estimate
provided as an attachment to EPRI's comment (see comment 2200 - Technical Report No
1022491). In support of the 6 month estimate, EPRI cited engineering estimates for four
nuclear plants that ranged from 5 to 22 months and noted that the expected downtime was
difficult to predict since there was a great degree of uncertainty given the lack of actual
data. A closed-cycle retrofit for these facilities that will not conduct an ECU would likely
occur concurrently with a refueling outage which now typically takes about 4 to 6 weeks
(see DCN 12-6876). Thus, the EPRI net downtime estimate of 6 months or 24 weeks
would be consistent with a total retrofit downtime of about 28 weeks. EPA notes that this
28 week value is consistent with the duration of the first steam generator replacement
project for SONGs Unit 2 and while this outage length is the higher of the two similar
projects at SONGS, the difference demonstrates that complex projects for which
contractors and engineers have little previous experience will tend to take longer. The
actual duration of the outage required for a nuclear closed-cycle retrofit is still unknown
167 EPRI assumed in their analysis that a certain portion of plants would re-optimize the cooling system
which includes replacement of steam condensers and reduction in cooling tower capital and operating costs.
Over the long term these cost reductions tend to offset the lost generation costs associated with longer
downtime. Since EPA did not include re-optimization in the economic analysis, a comparison to the EPRI
estimate excluding re-optimization is more appropriate.
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and will be influenced by site-specific factors. EPA determined that a 24 week estimate
was reasonable and applied this value in the economic analysis.
For the remainder of facilities that are likely to conduct an ECU in the future, EPA
estimates that under favorable conditions, ECUs typically have a duration of two to four
months (see DCN 12-6875) but can also take much longer. For this analysis, EPA
assumed that facilities performing an ECU would be capable of completing the retrofit
concurrently with the ECU and that the scope of the ECU would be extensive enough to
push the duration toward the longer end of the 2 to 4 month or longer range. For these
projects, EPA assumed zero downtime. See the Economic Analysis for Final 316(b)
Existing Facilities Rule for more details regarding the application. See also DCN 12-
6656. Based on data from the NRC, EPA estimates that roughly one-third of existing
nuclear generating units have already performed or have applied for an ECU and
therefore are assumed the a 24 week downtime. As a result, the equivalent average net
downtime across all nuclear units should be about 8 weeks (2 months).
Besides the type of plant, another factor investigated for consideration in estimating
construction downtime was CUR. Presumably facilities with low CUR values would have
greater opportunity to schedule cooling tower tie-in construction activities such that they
coincide with downtime periods of greater duration than the 4-week scheduled
maintenance period assumed in the 2004 Phase II rule. A review of monthly flow data
reported in the surveys for a sample of facilities with year 2000 CUR values in the 15
percent to 30 percent range was conducted. The data indicated that the cooling water
systems at most of these facilities operated at least a portion of every month during each
of the three years reported in the survey (1996, 1997, and 1998). While it is not clear
whether these facilities produced power each month, EPA assumed these facilities need
to be available for power generation. Since these facilities cannot accurately predict when
they would be dispatched, EPA did not presume additional downtime could be
guaranteed. CUR was not considered further as an indicator of available downtime for
these facilities.
Exhibit 8-11 below summarizes the net downtime estimates.
Exhibit 8-11. Net Construction Downtime for Closed-cycle Retrofit
Fuel type
Nuclear- ECU already
completed prior to retrofit a
Nuclear- Retrofit
concurrent with ECU
Non-nuclear
Net Downtime
(Weeks)
24
0
4
a Units that have already conducted an ECU or are currently
planning to conduct an ECU
Manufacturers
At proposal, EPA assumed that, unlike generating facilities, there would be no downtime
costs for closed-cycle cooling retrofits at manufacturing facilities due to the fact that
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manufacturers are often more segmented in their production and use of cooling water and
are more likely to be able to shut down individual intakes or process lines without
interrupting the production of the entire facility. Given that the Phase III rule did not
consider regulatory options requiring closed-cycle cooling, EPA has not previously
developed estimates for downtime at manufacturers for cooling tower retrofits.
At some facilities, generating systems provide electricity or electricity and steam
(cogeneration) to many processes within the plant and that interruption of the cooling
water source and thus the operation of generating/cogenerating system could impact plant
production. In response to comments received and an evaluation of new information,
EPA has revised the compliance cost methodology used in evaluating closed-cycle
cooling costs under proposal options 2 and 3 to include downtime costs for
manufacturing facilities. The methodology employed uses the same approach that was
employed for entrainment technology downtime, which assumes that the overall
manufacturing process will not suffer significant production losses and that the effect of
downtime is primarily associated with the effect on the generation system. These costs
are assessed as the equivalent cost of replacement electricity and lost revenue for offsite
sales of excess generation. For closed-cycle retrofits at manufacturing facilities, EPA
derived a closed-cycle retrofit downtime duration of 4 weeks which is similar to that for
non-nuclear generating facilities. This value was derived using a different basis.
At generating facilities, most of the power generated is distributed offsite and lost power
due to downtime is replaced by other generating units and plants via the grid. Whereas,
most of the power/steam generated onsite at manufacturing facilities is used onsite and
this configuration requires that interruptions to the operation of the generating system
must be accounted for using various contingencies including: offsite replacement sources
(e.g., utility grid connections); redundant (spare) generating capacity; temporary
replacement generating units; or temporary replacement cooling water sources. The
availability of these various contingencies varies by plant type and location and
insufficient data was available to enable EPA to assess availability of different
contingency methods. Thus it was not possible to divide facilities into groups where costs
could be assessed based on different contingency methods. Rather, EPA derived a single
approach that represents the average cost. Since generating units, whether they are
located at power generating facilities or at manufacturing plants, will require periodic
maintenance, it is reasonable to assume that manufacturing facilities will have included
within their design and operating schedule consideration of this contingency by including
sufficient spare generating capacity, access to replacement power through utility
connections, planned outages, that would allow for rotating maintenance downtimes for
individual generating units at least during periods of reduced demand. At many of these
facilities, the downtime costs will be minimal since the closed-cycle retrofit (which EPA
estimates may take up to 8 weeks) can be performed on individual generating units in a
manner that avoids interruption of the supply of electricity and steam. EPA expects that a
large portion of manufacturing facilities fall within this category. For those facilities that
rely upon replacement electric power from the grid, the costs would be for replacement
power for the generating unit downtime duration that exceeds the normal downtime for
generating unit maintenance which is estimated to be 4 weeks for power generating units
and is expected to be similar for these facilities.
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EPA recognizes that for those facilities that cannot rely upon multiple generating units
and excess capacity or replacement power from offsite, that costs for replacement of
electricity and steam generation capacity or replacement cooling water for the estimated 8
week retrofit duration may be necessary. While the cost of these temporary solutions may
exceed the costs for replacement electricity EPA, concluded based on site visit data and
the comments that such facilities are in the minority. The aggregate costs when balanced
against those facilities where EPA expects the cost will be zero should result in an overall
facility cost (average across all facilities) that is similar in magnitude to the 4 week
electricity replacement costs. Since EPA was unable to distinguish which facilities would
utilize the different types of contingency methods described here, EPA applied the 4
week electricity replacement downtime costs to all manufacturing facilities when
evaluating compliance options that involved a closed-cycle cooling retrofit.
8.3.5 Identifying Intakes That Are Already Compliant With
Entrainment Mortality Requirements
Existing intakes that were considered to be EM compliant included those that:
• Reported using a closed-cycle cooling system using towers only (i.e., not in
conjunction with any other type of cooling system)
Data from the 2000 detailed technical survey were used to determine intake compliance.
Existing intakes for systems that employed closed-cycle cooling were not assumed to be
IM-compliant and thus were assigned EVI compliance technology costs unless the intake
technologies also met the criteria for EVI compliance.
Combination Cooling Systems
Intakes for cooling systems that reported using a combination of cooling system types
(e.g., one intake is used to supply a once-through unit and a closed-cycle unit) were
treated as if all cooling water flow was once-through. Intakes that reported closed-cycle
cooling systems using impoundments were treated as if all cooling water flow was
closed-cycle. This was done because there was insufficient data available to determine
which portion of the intake water was used for once-through and which as makeup for
existing closed-cycle cooling. This approach is expected to produce conservative cost
estimates for these mixed cooling system facilities, since a portion of the flow may be
makeup water and not amenable to application of closed-cycle cooling technology.
Exhibit 8-12 below summarizes the number of facilities and intakes that were determined
to supply cooling water to closed-cycle cooling systems
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Chapters: Costing Methodology
Exhibit 8-12. Number of Model Facilities/CWISs Classified as Closed-Cycle
Intakes with full or partial once-
through in-place
Intakes with impoundment cooling
system
Intakes with full closed-cycle
recirculation in-place
Facilities with both full closed-
cycle and full once-through
intakes
Total facilities or intakes
Electric Generators
Number of
Model
Facilities
221
12
51
7
284
Number of
Model Intakes
with Separate
Cost Data
319
26
61
8*
406
Manufacturers
Number of
Model
Facilities
186
7
42
0
235
Number of
Model Intakes
with Separate
Cost Data
267
7
43
0
317
* Number of closed-cycle intakes.
8.4 Compliance Costs for New Units
Power generation and manufacturing units that meet the definition of a "new unit" will be
required to meet impingement mortality and entrainment mortality reduction
requirements. The costs for complying with the impingement mortality reduction
requirements are assumed to be zero since these costs are included in the cost for
complying with the entrainment mortality requirement (closed-cycle cooling or
equivalent) or were already expended in the past as part of the cost estimate for the
existing intake to comply with the existing facility impingement mortality requirements.
In order to comply with the entrainment mortality requirements, closed-cycle cooling or
an equivalent reduction in entrainment for the cooling water component of the intake
flow based on the design intake flow (DIP) will be required for new units. The estimates
for compliance costs for such new units should be based on the net difference in costs
between what cooling system technologies would have been built under the current
regulatory structure and what will be built given the change in requirements imposed by
the Final Regulation. Compliance costs are derived using estimates of the generating
capacity that will be subject to the requirement.
Based on this definition of new unit, EPA expects that for manufacturers, net compliance
costs associated with new unit will be negligible. A discussion of the rationale is
provided in Section 8.4.2 below. The following section describes cost development for
the new unit provision for Electric Generators only.
8.4.1 Compliance Costs for New Power Generation Units
New generating capacity at existing facilities can result from new units added adjacent to
existing units, repowering/replacement and major upgrades of existing units, and minor
increases in system efficiency and output. While a small portion of this new capacity may
result from minor improvements in plant efficiency and output, this analysis assumes all
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new capacity will be associated with either new units, repowered units, or major unit
rebuild/upgrades.
New Generating Unit Costs
The term "new units" consists of newly built units adjacent to existing units (aka stand-
alone). In nearly all cases, the repowering of an existing unit will result in an increase in
the generating capacity so the portion of new capacity associated with repowering must
be accounted for. For the purpose of this analysis, the estimate of new capacity is divided
into two categories: the stand-alone new unit capacity and the incremental increase in
capacity of the repowered units. Thus, this cost methodology requires the development of
annual estimates of the generating capacities for:
• Newly built unit capacity not subject to phase I (new stand-alone unit capacity)
• Increase in capacity for repowered units (new repowered capacity)
The analysis also considers the fuel type of new generating capacity. Generators that use
different fuels types each have a different thermal efficiency and therefore different
cooling water requirements in relation to generating capacity. Therefore, in order to use
generating capacity as the input variable for costs and flow reduction, separate estimates
are developed for each fuel type. For simplicity, the estimated generating capacities are
divided into three fuel types: coal, combined cycle, and nuclear, with coal being broadly
viewed as including all single cycle fossil and biomass generating systems. While nuclear
new units were initially considered by EPA is the analysis, EPA concluded that nuclear
new units would likely be compliant in the baseline 100 percent of the time and therefore
are excluded from the analysis since compliance costs would be zero dollars.
Basic Assumptions
The following assumptions are described in the Proposed Rule TDD Section 8.4 and are
retained for this analysis. The rationale for each is described in the TDD.
• Annual estimates of total new capacity (including both new stand-alone units and
new repowered capacity) for each fuel type are developed using the IPM model.
• 70 percent of newly built unit capacity will occur at new facilities and will be
subject to the 316(b) Phase I requirements.
• 10 percent of new coal and 85 percent of new combined cycle capacity will occur
as additional capacity at repowered units (new repowered capacity).
• Cooling water requirements for new units are 390 gpm/MW and 200 gpm/MW
for coal and combined cycle respectively.
The following additional assumptions were used in sizing a "typical" new unit:
• Average project size is 600 MW.
• Capacity utilization is 80 percent.
• 90 percent of stand-alone capacity at existing sites will be compliant in the
baseline (i.e., will install closed-cycle cooling regardless of the Existing Facility
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rule requirements). The exception is nuclear capacity which is assumed to be 100
percent compliant in the baseline.
Combining the two fuel types and three capacity estimate categories results in the
following compliance technology cost components:
1. New stand-alone unit coal capacity
2. New stand-alone unit combined cycle capacity
Exhibit 8-13 presents the factors that will be used to derive the estimated generating
capacity for each component.
Exhibit 8-13. Costs Factors for Estimating New Unit Capacity Values
Cost Component
1. New stand-alone unit
coal capacity
2. New stand-alone unit
combined cycle
capacity
New Capacity
% Not
Phase I
30%
30%
%
Greenfield
vs
Repowered
90%
15%
% Non-
comp. in
Baseline
10%
10%
% of Total.
New
Capacity
Non-comp.
2.7%
0.5%
Factors (1) and (2) are applied to estimated values of annual new capacity for each fuel
type.
For each new unit that requires closed-cycle cooling, the estimated generating capacity
serves as the basis for the compliance technology costs for each relevant component.
Exhibit 8-14 presents the estimated annual capacity values for each cost category based
on the assumptions described above.
Exhibit 8-14. Annual New Capacity Potentially Subject to New Unit Requirement by
Cost Category
Fuel Type
Fossil Fuel
Combined Cycle
Total
Total Including
Phase 1
New Capacity
MW
295
3,264
3,559
Existing Facility
New Units Only
Stand-alone
MW
80
147
227
Existing Facilities
Non-compliant
Only3
Stand-alone
MW
8
15
23
1 Capacity estimated to be subject to closed-cycle requirement
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Baseline Compliance
1 f\%.
New units will either use once-through, closed-cycle, or dry cooling systems . For the
baseline condition, an estimate is needed for the occurrence of each type of system that
would have been utilized if there were no change in the regulatory requirements for new
units. The occurrence of each type in existing cooling systems can serve as a guide since
both new and replaced units will, at a minimum, use a similar technology. EPA analyzed
trends in use of cooling system type from Energy Information Administration data and
determined that the trend in the 1990s was that 83 percent of new cooling systems
installed closed-cycle cooling systems and that the current and future trend was that
approximately 98 percent of new cooling systems would install a closed-cycle cooling
system (see DCN12-6672). Considering only 30 percent of new unit capacity would
occur at existing facilities, EPA concluded that a baseline closed-cycle compliance rate of
90 percent was reasonable.
Compliance Cost Estimation
Compliance costs were considered for new stand-alone units only. For new unit capacity,
costs are derived using the new unit capacity in MW as the input variable. Compliance
costs for new units use the EPA estimates for retrofitting a closed-cycle cooling system at
existing facilities as the starting point. For the existing facility closed-cycle retrofit costs
EPA used existing flow data and cost equations based on cooling flow in gpm. The cost
equations for new units are instead based on capacity in MW, with costs derived using
assumed cooling water requirements in gpm/MW. These cooling water requirements
assume that the typical new unit once-through system is designed with a condenser
temperature rise (AT) of 15 °F, and that the closed-cycle cooling system that replaces a
once-though system will be optimized using a AT of 20 °F. The cooling water flow
estimates are based on a AT of 20 °F and waste heat generation is based on plant
efficiency values of 42 percent for coal (which is the average of values for super-critical
and ultra-critical steam), and 57 percent for combined cycle.
Capital Costs
EPA has found that the total estimated capital costs for a once-through cooling system
including a new intake are comparable to the capital costs of a closed-cycle cooling
system. Therefore, the compliance capital costs are assumed to be $0 for new added
units.
O&M Costs
The O&M costs include costs associated with the assumption that 25 percent of facilities
will require plume abatement. Fixed and variable O&M costs are adjusted by deducting
the O&M costs estimated for the traveling screens that would have been used in the
baseline once-through system. The baseline O&M cost estimate is based on the cost tool
output for gross O&M for once-through traveling screens (Cost Module 1) using design
input values of: DIP = 132,500 gpm, screen velocity = 0.5 fps; well depth = 25 ft;
freshwater. The resulting gross O&M cost was equivalent to $1.6/gpm, which was then
Dry cooling is generally used in only a small portion of facilities in locations where water resources are
limited. Estimates of closed-cycle cooling are assumed to include dry cooling.
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reduced by 10 percent to account for the new makeup system O&M and then divided into
fixed and variable components using a fixed factor of 0.4.
Energy costs are also adjusted to account for the reduced pumping volume associated
with changing the AT from 15 °F to 20 °F and to account for an estimated increase in
pumping head of 25 ft for closed-cycle versus once-through operation.
Exhibit 8-15 presents the new unit costs on a $/gpm basis. Exhibit 8-16 presents the
equations used for estimating costs based on unit generating capacity derived from
Exhibit 8-15 data using the gpm/MW values shown.
Exhibit 8-15. Costs for New Units Based on GPM
Costs and Generating
Output Reduction
Capital Cost- New
Unit with Intake (CC)
Fixed O&M Cost
(OMF)
Variable O&M -
Chemicals (OMC)
Variable O&M - Pump
& Fan Power (OMV)
Energy Penalty - Heat
Rate (EP)
Equation
CC = DIF(gpm)x
Constant
OMF = DIF(gpm)x
Constant
OMC=DIF(gpm)x
Constant
OMV=DIF(gpm)x
Constant
EP=MWS x
Constant
Constant
Adjusted for
Optimization
(2009)
$0
$1.27
$1.25
0.00001 90b
0.000
Add for 25%
Plume
Abatement
$0
$0.25
$0.00
0.00000078
0
Baseline O&M
Adjustment3
-$0.58
-$0.86
Total Adjusted
Net Cost
$0
$0.94
$0.39
0.0000198
0
a Adjustment reflects deduction of O&M costs associated with traveling screens that would have been installed in the
baseline once-through system.
b Net pump energy includes deduction of once-through pumping energy
Costs are in 2009 dollars
Exhibit 8-16. Costs for New Units Based on Generating Capacity
Costs and Generating Output
Reduction
Capital Cost - New Unit with
New Intake (CC)
Fixed O&M Cost (OMF)
Variable O&M - Chemicals
(OMC)
Variable O&M - Pump & Fan
Power (OMV)
Energy Penalty -Heat Rate
(EP)
Equation
CC = MWS x Constant
OMF = MWS x Constant
OMC= MWS x Constant
OMV= MWS x Constant
EP=MWS x Constant
Units
GPM/MW
Dollars
Dollars
Dollars
MW
MW
Coal (42%
Efficient)
390
$0
$366
$151
0.0077
0
Combined
Cycle (57%
Efficient)
200
$0
$188
$77
0.0040
0
Costs are in 2009 Dollars
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Downtime
Stand-alone units by definition are constructed somewhat independently of existing
generating and manufacturing units which will tend to limit interference with the
operation of existing production units. Some construction downtime may occur when
new units must be integrated with existing production units, shared ancillary systems,
utilities, and cooling water intake systems. However many of the construction activities
resulting in downtime would occur regardless of the cooling system requirements.
Further, as a new unit is defined as a stand-alone unit, by this definition EPA expects
minimal integration and sharing resources will occur. EPA has concluded that requiring
closed-cycle cooling should result in no net increase in downtime for the existing units.
Thus, no downtime costs are assessed for new unit compliance.
Energy Penalty
Energy penalty costs associated with net changes in auxiliary power requirements
between once-through and closed-cycle cooling are included in the O&M cost estimates
shown in Exhibit 8-18. For the heat rate penalty, new unit construction will involve new
steam turbines, condensers, and cooling towers using an optimized design. As such, the
system design can be tuned such that heat rate penalty that would otherwise be associated
with replacing the once-through system with a closed-cycle cooling system at an existing
facility is assumed to be minimal. Thus, no costs are assessed for the heat rate penalty.
8.4.2 Compliance Costs for New Manufacturing Units
The projected baseline manufacturing unit process design and cooling water technology
would be based on an estimate of the response to the permitting authorities' application
of existing requirements including 316(b), applicable industrial water use and discharge
standards (e.g., categorical standards), and BPJ. Also, it has become standard practice for
industries to adopt water use reduction and reuse practices wherever practical. The
construction of a new unit provides a perfect opportunity to employ such measures to an
extent that would not be possible for existing units. In many cases, it is likely that the
existing regulatory requirements and practices would have resulted in a further reduction
in the cooling flow than for similar but older units. Thus, the baseline cooling AIF for
"new units" at manufacturers should, in most cases, be much smaller than the AIF for a
comparable existing unit.
For new units in general, EPA has noted the following differences in costs between a
closed-cycle cooling retrofit at an existing facility compared to closed-cycle cooling at a
"new unit:"
• New units can incorporate closed-cycle cooling in a more cost-effective manner.
• The duration of new unit construction is sufficiently long that there would be, in
nearly all circumstances, no net increase in "construction downtime."
• Stand-alone unit would need minimal is any integration with existing processes.
• Where new intakes or major components of the existing once-through intake and
cooling system must be constructed/upgraded, the capital costs of closed-cycle
cooling for new units are comparable to the capital costs of once-through cooling.
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• The cooling system costs usually comprise less than 1 percent of the total costs of
a new unit.
• New construction allows the use of an optimized cooling system design that can
minimize any system efficiency losses associated with conversion to closed-cycle.
• The fact that a large proportion of intake flow is used for process water and other
non-cooling purposes greatly increases the opportunity to design and incorporate
cooling water reuse strategies within the new unit.
• Where the new unit is not substantially larger than the existing plant, cooling
water reduction may be accomplished through reuse at other units within the
plant.
• The modular nature of closed-cycle cooling allows for the limited application of
closed-cycle cooling only to the portion of cooling flow necessary to meet any
additional reductions not accounted for by any other reuse/reduction strategies
employed.
• The modular nature of closed-cycle cooling allows for the use of cooling system
designs specifically tailored to process requirements and vice versa.
• The modular nature of closed-cycle cooling and the flexibility inherent in building
a new process system allows for more optimum placement of cooling tower units,
thus minimizing piping costs.
• New unit construction provides a lower cost opportunity to install variable speed
pumps and other system controls in cooling system applications. Flow reductions
associated with the use of variable speed pumps and other controls can result in
benefits associated with reduced flow and pumping energy costs and better
process control.
For power generation facilities that use once-through cooling, process water typically
constitutes a few percent or less of the total intake volume and the majority of the intake
flow is used for non-contact cooling purposes. A review of the responses to the detailed
technical survey showed that the median and average values for the percent of design
intake flow used for cooling purposes reported for each separate cooling water intake at
power generation facilities were 100 percent and 85 percent, respectively.
In contrast, most industrial manufacturing operations utilize a substantial portion of
intake water for non-cooling purposes and the same median and average values for
manufacturing facilities were 50 percent and 52 percent, respectively. In addition, the
cooling flow component at manufacturers will in many instances include contact cooling
water which would not be subject to the "new unit" requirements, thus decreasing the
proportion of cooling flow subject to the "new unit" requirements. This is consistent with
the NCCW/DIF ratios shown in Exhibit 8-10 ranging from 32 percent to 65 percent.
Given this, it is reasonable to assume a "typical" manufacturing unit may use less than 50
percent of flow for cooling purposes of the type that may be subject to the "new unit"
requirements. Theoretically, this "typical" facility should be able to reuse 100 percent of
the cooling water in place of the process component. Thus, the "typical" manufacturing
facility should be capable of designing a "new" process that could meet the "new unit"
requirements through water reuse alone. EPA observed extensive use of innovation and
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water reuse during site visits at some manufacturing facilities. Such reuse opportunities
may be limited at facilities that use brackish or saltwater for cooling, but based on intake
location EPA estimates that at most 7 percent of manufacturing plants do so.
Since this 50 percent value is the median of all reported manufacturing cooling water
intake systems, at least half of manufacturing cooling water systems have the potential to
meet the "new unit" requirements simply by reusing non-contact cooling water as process
water. For the remainder, modifications to the process that reduce cooling water use (e.g.,
use of variable speed pumps) may provide additional reduction. For some, there may be a
need to install cooling towers for the cooling flow component that cannot be reused. This,
however, will in most instances be a small portion of the total intake flow. Also, in most
cases the "new unit" will comprise only a portion of the entire manufacturing facility and
there may be other process units and plant operations nearby that could reuse the cooling
water in order to meet the flow reduction requirements.
For new units that would require building or rebuilding a once-through intake, EPA has
found that the capital costs of the new intake and screen technology which may require
additional costs to meet impingement mortality requirements such as a larger intake with
deeper and wider pump and intake wells to accommodate source water depth variations
will be comparable and possibly higher than the capital costs for closed-cycle technology.
In these cases, closed-cycle may have slightly higher O&M costs for pump and fan
energy, but these costs may be offset by other cost savings such as reductions in water
treatment costs.
The definition of new manufacturing units limits the applicability of closed-cycle
requirements to new units that involve construction of stand-alone units. As such, it is
assumed that the construction activities involving any substantial downtime periods
would be of similar or more likely greater duration than required for construction and tie-
in activities associated with the closed-cycle cooling technology alone.
Given all of this, EPA concluded that only a small portion of new units would need to
meet new unit flow reduction requirements through increased use of closed-cycle cooling
over what would have been built under existing regulatory requirements. As a result,
EPA concluded that the net (incremental) compliance costs would, on average, be zero.
8.5 Impingement Mortality Costs at Intakes with Cooling
Systems Required to Install Closed-Cycle Cooling
EPA has deemed closed-cycle cooling technology as being compliant with the
impingement mortality standard. This is based on the assumption that a flow reduction of
greater than 90 percent would in nearly all cases meet the BTA impingement mortality
standard of 24 percent. This would certainly be true for power plants with once-through
cooling systems where the majority of the intake water is used as non-contact cooling
water (NCCW). The same is true for most manufacturing facilities since as shown in
Exhibit 8-10, the average NCCW component of most of the manufacturing facilities
evaluated was greater than 77 percent of flow based on schematic flow diagrams. In most
cases for those facilities that employ closed-cycle cooling for their NCCW flow
component of greater than 77 percent should have little problem meeting the
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impingement mortality standard. These estimated NCCW component values are averages
and it is expected that some facilities with lower NCCW components might not meet the
impingement requirement based on flow reduction alone. However, in most cases the
flow reduction associated with closed-cycle cooling for the NCCW component should
allow them to meet the impingement mortality standard by either meeting the velocity
standard as a result of the reduced flow or by the combined reduction of multiple
technologies employed.
8.6 Costs for Each Regulatory Alternative
As described in the preamble, EPA evaluated four primary regulatory options during the
analysis for the final rule. One option would require only impingement mortality at all
facilities (i.e., modified Ristroph screens everywhere), a second would require
impingement mortality and entrainment mortality at all facilities (i.e., wet cooling towers
everywhere), a third would require impingement mortality at all facilities and entrainment
mortality at facilities with a design intake flow greater than 125 mgd, and a fourth would
require impingement mortality at facilities with a design intake flow greater than 50 mgd
and site-specific BPJ for those less than 50 mgd. In addition, entrainment reduction is
required for all "new units" as defined in the preamble.
The sections above describe how facility-level costs were derived for each set of
requirements (either impingement mortality or entrainment mortality). To calculate the
total cost for a regulatory alternative, the facility-level costs for the applicable
requirements were simply summed. For example, for the option where cooling towers are
required at each facility with a DIP greater than 125 mgd, EPA used facility-specific data
to identify model facilities that fell above and below the flow threshold and used the cost
that corresponded to the appropriate compliance response. These facility-level costs are
then used to calculate national level economic impacts, as described below.
8.7 Compliance Costs Developed for Analysis of National
Economic Impacts
To assess the national economic impacts of its regulatory options, EPA conducted several
analyses; these are documented in the EA. As part of these analyses, EPA conducted a
modeling analysis using the Integrated Planning Model (IPM) to develop a worst-case
impact analysis for power generators.169 EPA can conclude that if no national economic
impacts were observed as a result of the worst-case option, then less costly regulatory
options would also have no national economic impacts. This section describes the technical
data used in developing the IPM modeling; for more information, see the EA.
In contrast to the model facility costing approach, the IPM model requires an estimate of
facility-level costs for all existing facilities (including those facilities that completed an
STQ). 17° Facility-level costs were calculated by first estimating costs for the same subset
169
170
For a detailed discussion of the IPM analysis, see the EA.
The DIP for facilities that completed the short technical questionnaire was estimated on the basis of the
average daily flow as described in the preamble to the 2004 Phase II final rule. See 69 FR 41650.
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of facilities used in the model facility approach described above. To derive costs for STQ
facilities, EPA then aggregated the data to derive cost equations that were used to
calculate STQ facility-level costs using DIP as a scaling factor.
8.7.1 Selection of DIP as the Primary Scaling Factor for Power Plants
Several power plant attributes related to facility size were evaluated to determine which
would best serve as input values for the IPM model cost equations. The use of plant
generating capacity was evaluated by comparing the year 2000 steam generating capacity
to the DIP reported in the detailed year 2000 surveys for plants with once-through
cooling systems. It was concluded that there was insufficient correlation between steam
generating capacity and the DIP to use the generating capacity as the sole basis for
estimating cooling system size and costs.1?1
Because the cost derivation methodologies used by EPA in the past and by EPRI for
developing cooling tower retrofit costs used the design cooling water flow rate (i.e., the
DIP), the DIP was selected as the basis for estimating model facility costs. Where such
data were not available, the DIP was estimated using the average ratio of DIP to steam
generating capacity (gpm/MW) for those facilities with once-through cooling systems.
The cost data used to derive the national average technology cost equations relied on data
only from facilities that reported design cooling water intake flow volumes in the detailed
surveys. Exhibit 8-17 below shows the equation used to estimate DIP on the basis of
steam generating capacity for facilities where insufficient design or actual flow data were
available to estimate the DIP. This equation was used only for facilities that did not
complete a technical questionnaire (short or detailed) and was estimated using a formula
based on the overall average DIF/MW ratio for power generators with once-through
cooling systems with DIP greater than 50 mgd.
Exhibit 8-17. Estimation of DIF Where No DIF Data Exists
Design Intake Flow (DIF)
Equation
DIF = MWS x constant
Constant
707
Units
gpm
MWS = Megawatts of steam = Total facility steam electric generating capacity.
The reported or estimated DIP volumes are used as input values in the cost-estimating
equations so that the average national technology costs can be scaled to account for
differences in plant/intake size.
171 Theoretically, for once-through cooling systems, cooling water flow should have correlated well with
steam generating capacity, but it did not. The following are likely reasons for the lack of good correlation:
the fact that the temperature rise across the condenser (AT) can vary between plants, the fact that even those
plants considered as once-through can use varying amounts of closed-cycle cooling for some of the
generating capacity, and the fact that reported design intake flow might include substantial volumes of
water used for other purposes.
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Chapters: Costing Methodology
8.7.2 Development of IM&EM Control Costs for IPM Model
The IPM Model facility cost equations for IM&EM controls were derived using the
intake technology cost data described above for each model facility intake. As described
above, cost modules were assigned as shown in Exhibits 8-1 and 8-2.
The first step to derive the IPM model facility cost equations was to derive a single value
for each cost item for each facility. Total costs for each facility were derived by summing
the capital, O&M, and pilot study costs of each intake. For most facilities, the cost
module was the same for all intakes, so single facility-level values were assigned for the
net downtime and the service life on the basis of the most common cost module assigned
to the intakes.
Various methods for using this data to estimate costs were evaluated, including using the
between-facility average or median of the $/gpm ratios, and using trend lines derived by
Excel (which uses a least squares method). It was concluded that a simple straight-line
equation with Y-intercept equal to "0" using the overall between-facility average of the
individual facility cost to DIP ratios ($/gpm) represented a reasonable estimate for the
national model facility costs.
After deriving the facility-level costs, weighted averages of the cost to DIP ratio ($/gpm)
were calculated for all facilities that had compliance costs (i.e., facilities with zero costs
were not included). The same facility weights described above were used. Weighted
average values for the facility net construction downtime and technology service life
were also calculated. The net O&M fixed component was calculated as a portion of the
net O&M costs using a factor derived from the weighted average of the ratio of fixed
gross technology O&M to the total gross technology O&M. Exhibit 8-18 below present
the model facility cost equations for EVI reduction technology based on modified Ristroph
traveling screens or. Exhibits 8-19 and 8-20 present the service life and calculated
technology net construction downtime.
Exhibit 8-18. Cost Equations for Estimating Model Facility Costs of Impingement
Mortality Controls for the IPM Analysis
Cost Item
Capital Cost (CC)
Pilot Study costs (PC)
Net O&M Cost (OM)
Fixed Net O&M Cost (OMF)a
Variable Net O&M (OMV)
Equation
CC = DIF(gpm) x Constant
PC = DIF(gpm) x Constant
OM = DIF(gpm) x Constant
OMF = DIF(gpm) x Constant
OMV = DIF(gpm) x Constant
Constant
$20
$0
$0.62
$0.31
$0.31
Output Units
2009 Dollars
2009 Dollars
2009 Dollars
2009 Dollars
2009 Dollars
a Fixed O&M component based on values for compliance gross O&M
Technology Service Life
Estimates of technology service life were also required for the economic models. In the
2004 Phase II economic analysis, EPA assumed a useful life of 10 years for nearly all of
the compliance technologies, with the exceptions that a useful life of 30 years was used
for cooling towers and a useful life of 20 years was used for condenser upgrades
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associated with the cooling tower retrofit. Also, one-time costs such as initial permitting
and connection downtime were annualized over a 30-year period, which was the
maximum time period for the technology cost analysis.
EPA has re-evaluated the estimated service life of each compliance technology based on
various sources of information and BPJ. Exhibit 8-19 presents the revised service life
estimates for all of the compliance technology modules used or considered for use in the
economic analyses.
Exhibit 8-19. Estimated Technology Service Life
Module No.
-
1
2
2a
3
4
5
6
7
8
9
10
10.1
10.2
10.3
11
12
13
14
Module Description
Cooling Towers
Replace Screen with Coarse Mesh Ristroph Traveling Screen
with Fish Handling and Return System
Replace Screen with Fine Mesh Ristroph Traveling Screen with
Fish Handling and Return System
Add Fine Mesh Overlay Screens Only
Add New Larger Intake Structure with Coarse Mesh Ristroph
Traveling Screen and Fish Handling and Return
Relocate Intake to Submerged Near-shore (20 M) with Passive
Screen (1.75 mm mesh)
Add Fish Barrier Net
Aquatic Fish Barrier (Gunderboom)
Relocate Intake to Submerged Offshore with passive screen
(1.75 mm mesh)
Add Velocity Cap at Inlet
Add Passive Fine Mesh Screen (1.75 mm mesh) at Existing Inlet
of Offshore Submerged
Module 2 plus Module 5
Module 2a plus Module 5
Module 3 plus Module 5
Module 1 plus Module 5
Add Double-Entry, Single-Exit with Fine Mesh, Handling and
Return
Relocate Intake to Submerged Near-shore (20 M) with Passive
Fine Mesh Screen (0.75 mm mesh)
Add 0.75 mm Passive Fine Mesh Screen at Existing Inlet of
Offshore Submerged
Relocate Intake to Submerged Offshore with 0.75 mm Passive
Screen
Service Life (Years)
30
20
20
20
25
30
30
30
30
30
30
20
20
25
20
20
30
30
30
Exhibit 8-20 presents the model facility technology net construction downtime and
service life.
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Exhibit 8-20. Technology Downtime and Service Life for Model Facility Costs of
Impingement Mortality Controls for the IPM Analysis
Net Construction Downtime
Service Life
Units
Weeks
Years
All Facilities
0.3
20a
a Actual calculated values were 20.7 years for 510 mgd and 27.5 years for less than 10 mgd. Values were revised to
obtain conservative rounded values more amenable to use with IPM model.
8.7.3 Development of Closed-Cycle Cooling Tower Costs for IPM
Model
For the IPM analysis, the model facility costs for closed-cycle cooling have already been
derived; they are the same equations from Exhibit 8-9. The difficult cooling tower retrofit
capital costs were used to further reflect worst-case conditions. The net construction
downtime estimates used to derive the IPM model costs are shown in Exhibit 8-11.
8.7.4 Cost to Comply with Streamlined Compliance and Alternative
Provisions Option
The impingement mortality data presented in Chapter 11 indicate that nearly half of
facilities employing modified traveling screens may have difficulty consistently
complying with the impingement mortality BTA standards based on the performance of
the modified traveling screens alone. While many of these facilities may be capable of
making improvements to the operating conditions and screen design such that screen
alone would meet the Director's assessment of BTA compliance without additional
capital outlay. Some may choose to rely upon the combined performance of a system of
technologies such as traveling screens plus additional technologies and operational
measures such as flow reduction, reduced facility operations other than maintenance
outages, louvers, behavioral and avoidance technologies tuned for select species of
concern, barrier nets, offshore intake location, seasonally based technologies or
operational measures. To account for these costs, EPA included costs for the addition of
barrier nets at all (unmodified) traveling screens at intakes located on oceans, estuaries
and tidal rivers. As shown in Exhibit 8.21, 18 percent of intakes assigned upgraded
traveling screens were also assigned barrier net costs. EPA assumed that the annualized
barrier net costs are comparable or greater than the costs of the range of technologies that
might actually be selected.
In some cases, additional EVI reducing technologies may already be included in the
existing technology suite and thus, their impact will be factored into the compliance
determination. Exhibit 8-21 presents an estimate of the proportion of exiting intakes
assigned costs for upgraded modified traveling screens that were assigned barrier nets or
already employ additional technologies that may result in a further reduction in the
impingement mortality rate beyond that of the traveling screen alone. As can be seen
nearly 40 percent of intakes costed for traveling screen upgrades were either assigned or
already employed an additional EVI reduction technology that should provide an
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additional IM rate reduction sufficient to ensure the "system of technologies" meets the
BTA IM standards.
Exhibit 8-21. Intakes Costed for Modified Traveling Screens that Include New
Barrier Nets or Existing Other IM Reduction Technologies
Assigned and Existing Technologies
Costed for Traveling Screens (1 & 10.3)
Costed for Traveling Screens & Barrier Nets (10.3)
Costed for Traveling Screens Only (1 )
Costed for Traveling Screens Only with Existing Fish Avoidance
Costed for Traveling Screens Only with Existing >500 ft Offshore Intake
Costed for Traveling Screens Only with Existing Combination Cooling
(Partial Closed-cycle Cooling)
Costed for Traveling Screens Only with at Least One Existing IM
Reduction Tech
Costed for Traveling with New Barrier Net or Traveling Screen with
Existing IM Reduction Tech
Intake Count
551
92
459
17
21
86
110
202
% of Total
100%
17%
83%
3%
4%
16%
20%
37%
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Chapter 9: Impingement Mortality and
§ 316(b) Existing Facilities Final Rule - TDD Entrainment Reduction Estimates
Chapter 9: Impingement Mortality and Entrainment
Mortality Reduction Estimates
9.0 Introduction
This chapter presents impingement mortality and entrainment mortality reduction
estimates associated with each of the regulatory options EPA considered in developing
the Existing Facilities rule. EPA estimated impingement mortality and entrainment
mortality reductions to evaluate the effectiveness of different treatment technologies.
EPA also used this information in analyzing potential benefits associated with the final
rule. See the BA for more details on these analyses.
9.1 Technology Reduction Estimates
EPA's regulatory options (see the preamble for discussion of the options) are based on
the following technologies:
• Modified Ristroph traveling screens with a fish return or equivalent
• Low intake velocity
• Existing offshore velocity cap
• Flow reduction as achieved by wet mechanical draft cooling towers
EPA's methodology for estimating impingement mortality and entrainment reduction for
these technologies varies depending on available data.
9.1.1 Screens
As explained in Chapters 2 and 11 of this document, EPA developed a performance
database that analyzed quantitative data on the efficacy and impingement mortality and
entrainment reduction associated with various technologies. This analysis formed the
basis for establishing the performance standard for impingement mortality at 76 percent
survival.
Since the proposed rule, EPA has also identified data that characterizes shellfish
mortality reductions and has included them in developing the impingement mortality
standards. As a result, EPA has eliminated the regulatory requirement for barrier nets at
marine facilities.
9.1.2 Low Intake Velocity
A facility that reduces its intake velocity to 0.5 ft/sec or below is assumed to meet the
performance standard for impingement mortality. Data collected by EPA (see DCN 10-
6705) shows that 96 percent of studied fish can avoid an intake structure when the intake
velocity is 0.5 ft/sec or less.
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Entrainment Reduction Estimates § 316(b) Existing Facilities Final Rule - TDD
9.1.3 Existing Offshore Velocity Cap
A facility with an existing intake velocity cap that meets the definition of offshore
velocity cap (i.e., a minimum distance of 850 feet) is assumed to meet the performance
standard for impingement mortality. Data collected by EPA (see DCN 12-6601) shows
that velocity caps in combination with a far offshore location are capable of meeting the
performance standard for impingement mortality at 76 percent survival. Two studies
identified a far offshore intake location alone as reducing impingement by 60 to 68
percent. Offshore intakes not meeting the minimum distance of 850 feet demonstrate
considerably less reductions in impingement, some performing as low as 7 percent
survival (see SEAMAP data). Eight studies at facilities with velocity caps showed the
velocity caps alone provided anywhere from 50 to 95 percent reductions in impingement
mortality. One additional study specifically identified the combined effects of location
and velocity cap as 76 percent performance. Therefore, the data in the record concerning
the 11 existing facilities with velocity caps show that a velocity cap alone is insufficient
to achieve the BTA standard, but that a velocity cap in combination with a far offshore
intake would perform equal or better than EPA's BTA performance standard. EPA
provides for newly constructed offshore velocity caps the opportunity to make a
demonstration that the facility specific performance of an offshore velocity cap would
meet the performance standard using the combination of technologies approach at 40
CFR 125.94(c)(6).) The offshore component likely makes the velocity cap technology
unavailable except to facilities in marine waters and certain Great Lakes locations;
therefore, the technology is not BTA. Further, since location is an important aspect of
velocity cap performance, and since the performance with respect to intake location and
distance offshore could not be reliably predicted, EPA did not assign new retrofit velocity
caps as a compliance technology.
9.1.4 Flow Reduction Commensurate with Closed-Cycle Cooling
As explained in Chapter 6, both entrainment and impingement (and associated mortality)
at a site are generally proportional to the intake flow. In other words, if a facility reduces
its intake flow by 50 percent, it similarly reduces the amount of organisms subject to
impingement and entrainment by 50 percent. For the traditional steam electric utility
industry, available data172 demonstrate that facilities located in freshwater areas that have
closed-cycle, recirculating cooling water systems can, depending on the quality of the
makeup water, reduce water use by up to 97.5 percent from the amount they would use if
they had once-through cooling water systems. Similarly, steam electric generating
facilities that have closed-cycle, recirculating cooling systems using salt water can reduce
water usage by up to 94.9 percent when makeup and blowdown flows are minimized.173
On average, closed-cycle cooling employed across the nation would reduce intake flows
by 96 percent.
172 See Chapter 6 of the TDD.
173 See Chapter 2 of the TDD for additional discussion of how these flow reduction values were derived.
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§ 316(b) Existing Facilities Final Rule - TDD Entrainment Reduction Estimates
Accordingly, a facility that is required to reduce its flow commensurate with closed-cycle
cooling would realize a significant reduction in its impingement and entrainment impacts.
For purposes of calculating reductions in impingement mortality and entrainment, EPA
correlates flow reductions to I&E reductions in a linear fashion. EPA applied the same
approach to I&E reductions as a result of flow reduction provided such flow reductions
are obtained throughout the year and represent an annual average basis. For example,
variable speed drives reducing annual intake flows by an average of 7 percent would
assume to result in a 7 percent reduction in annual I&E. On the other hand, seasonal flow
reductions such as plant shutdown for 12 weeks in the late summer equating to a 25
percent annual flow reduction is not assumed to result in a 25 percent reduction in annual
I&E. This is because the density of organisms and their susceptibility to I and E may vary
over the year.
9.2 Assigning a Reduction to Each Model Facility
As explained in Chapter 8 of this document, EPA estimated costs for each model facility
to comply with the regulatory options it considered for the final rule. In general, to
develop model facility costs, EPA reviewed the impingement mortality and entrainment
mortality requirements for a particular option and determined if each model facility
would be able comply with the requirements based on their existing technologies (e.g.,
has existing intake technologies that serve as the basis for the option or exhibit equivalent
performance). For each model facility that EPA projected would not be able comply with
the regulatory option requirements, EPA estimated costs to install and operate additional
impingement mortality and entrainment mortality minimization technologies. EPA's
assignment of costs to model facilities is relevant to its impingement mortality and
entrainment mortality reduction estimates because EPA only assigns reduction estimates
to model facilities that incur compliance costs.
For example, if a facility is subject to impingement mortality requirements but has only a
conventional coarse mesh traveling screen, it would have been assigned costs to replace
the screen with a modified Ristroph screen (or similar technology). Accordingly, a
reduction in impingement mortality of 75 percent was assigned to this facility to reflect
the improved performance of the new screens.174
Once EPA determined a compliance response for each model facility under a given
regulatory option, EPA similarly assigned impingement mortality and entrainment
reductions, as applicable. EPA assigned impingement mortality and entrainment
mortality reductions as illustrated in Exhibit 9-1 below.
174 Note that this does not imply an 75 percent improvement over conventional screens; it simply represents
the improved survival of organisms.
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Chapter 9: Impingement Mortality and
Entrainment Reduction Estimates
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 9-1. Reductions in Impingement Mortality and Entrainment Mortality
Control Technology Assigned
Modified Ristroph Screens or
equivalent
Reduced Intake Velocity
Closed-cycle cooling (fresh
water)
Closed-cycle cooling (salt water)
Reduced Intake Velocity via
Variable Speed Pumps
Impingement Mortality
Reduction
75%175
96%
97.5%
94.9%
96%
Entrainment Mortality
Reduction
0%
0%
97.5%
94.9%
20%
A facility may be subject to one or both requirements, as shown in the examples below:
• a facility that does not have compliant impingement mortality technologies (e.g.,
intake velocity of 0.5 ft./sec, qualified modified traveling screens, combination of
technologies that meet the impingement mortality standard, or existing far
offshore intakes) would reduce impingement mortality by retrofitting one or more
technologies that comply with one or more of the impingement mortality
requirements176
• under Proposal Option 2,17? a facility with a design intake flow over 125 mgd
with no flow-reduction technologies would be subject to both impingement
mortality and entrainment mortality requirements
A large number of existing facilities use multiple intake structures. To account for this
configuration, a flow-weighted average was used across each intake. As before,
reductions are based on the engineering costs and compliance response for each intake;
intakes that are assigned a new technology were also assigned a reduction. For example,
if a facility has two intakes with equal design intake flows but one uses a modified
Ristroph screen and one does not, the impingement mortality reduction would be 37.5
percent—the flow-weighted result of having one compliant intake and one non-compliant
intake.
As such, there are a wide variety of compliance responses among the model facilities.
Facilities may also exhibit partial compliance; for example, some facilities have a partial
(or combination) closed-cycle system, where some units utilize a closed-cycle system and
others use once-through cooling. Other facilities may have one intake with a modified
175 For the final rule, EPA calculated a revised 12 month impingement mortality performance standard of
24 percent; see Chapter 11. EPA did not revise the I&E reductions, instead noting that the change from
proposal from 25 percent to 24 percent mortality is such a small change and a small source of uncertainty
that it did not warrant a complete recalculation of the I&E reductions.
176 Facilities can either reduce screen velocity to less than or equal to 0.5 fps, install modified traveling
screens that are deemed equivalent to BTA by the Director, or employ a combination of technologies or
operating conditions that together reduce impingement mortality rates to levels equivalent to or greater than
the impingement mortality standard. Such technology combinations are assumed to have impingement
mortality rate reductions equivalent to modified traveling screens.
177 Proposal Option 2 which was considered but rejected in the final rule requires facilities with a design
intake flow greater than 125 mgd to conduct an entrainment
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 9: Impingement Mortality and
Entrainment Reduction Estimates
Ristroph screen and another without. In these cases, EPA assumed that those intakes
using the compliant technology would be considered as complying with impingement
mortality or entrainment mortality requirements and calculated impingement and
entrainment reductions using a flow-weighted average across all of the facility's intakes.
9.2.1 Entrainment Mortality
In the 2004 Phase II rule, EPA made the assumption that any entrained organism died
(i.e., 100 percent mortality for organisms passing through the facility) and any organism
not entrained survived. In other words, if a technology reduced entrainment by 60
percent, then EPA estimated 40 percent of the organisms present in the intake water
would die in comparison to 100 percent in the absence of any entrainment reduction. As
discussed in the preamble, EPA views entrainment (i.e., exclusion) and entrainment
mortality as the same. The reductions discussed in this chapter reflect those changes.
9.2.2 In-Place Technologies
If a facility has already installed a technology that is compliant with the applicable EVI or
EM standards, it is not assigned a technology (i.e., it is not assigned technology costs)
and therefore is not assigned a reduction in EVI or EM. In all other cases, the full
reduction for EVI or EM is applied to that intake structure. See Exhibits 8-1 and 8-2 for a
decision tree of how compliance technologies were assigned.
9.2.3 Summary of Options
Exhibit 9-2 summarizes the percent of flow and environmental impacts addressed by each
option considered under the final rule.
Exhibit 9-2. Summary of Primary Options
Option
Final Rule
Proposal Option 2 (IM for All, EM for
AIF>125MGD)
Proposal Option 3 (IM for All, EM for All)
Proposal Option 4 (IM For All, IM for DIF
>50 MGD)
Percent of Design Flow
Covered (%)
Impingement
Mortality
100%
100%
100%
100%
Entrainment
Mortality
0%
87%
100%
0%
Applies To
Impingement
Mortality
X
X
X
X
Entrainment
Mortality
X
X
Each of the model facilities used in costing (see Chapter 8) is then assigned a percent
reduction corresponding to the technology assignment made to that model facility. For
example, as discussed in 9.2.2 a facility that already has closed-cycle does not get
assigned any reductions. These model facility level percent reductions for I and E are
then matched with a baseline count of organisms depending on the "benefit region" in
which the model facility intake is located; see the BA for methodology and results.
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§ 316(b) Existing Facilities Final Rule -TDD Chapter 10: Non-water Quality Impacts
Chapter 10: Non-water Quality Impacts
10.0 Introduction
For the 2004 Phase II rule, EPA conducted an analysis of non-water quality impacts
resulting from the conversion of some facilities to recirculating wet cooling towers.
These impacts include increased air emissions due to energy penalties, vapor plumes,
noise, salt or mineral drift, water consumption through evaporation, and solid waste
generation due to wastewater treatment of tower blowdown (see the 2002 proposed rule
TDD Chapter 6, DCN 4-0004). For the Proposed Existing Facility rule, EPA reviewed
these impacts and supplemented the air emissions, vapor plumes, noise, and evaporative
consumption analyses as described in the following sections. EPA also briefly reviewed
the data available on non-water quality impacts of thermal effluent discharges. Since the
options involving closed-cycle cooling considered under the final rule are similar to those
considered in the proposed rule, EPA concluded that no significant changes in the
estimated non-water quality impacts is expected and therefore has not updated the
analysis.
10.1 Air Emissions Increases
In developing the 2002 proposed Phase II rule, EPA estimated the incremental increases
in emissions for 59 model power plants expected to retrofit from once-through cooling to
recirculating wet cooling towers under the preferred alternative (see the 2002 proposed
rule TDD Chapter 6, DCN 4-0004).178 These model facilities included nuclear, combined
cycle and fossil fuel-fired power plants. As described in the 2002 proposed rule TDD and
in the BA for the Existing Facility rule, facilities retrofitting to recirculating wet cooling
towers incur an energy penalty due to the increased electricity generation needed to
compensate for the loss of efficiency caused by the retrofitted cooling towers. This results
in a slight increase in emissions from the increased burning of fuel.179'180 Note that the
current emissions rate calculations discussed below do not reflect full implementation of
the most recent air rule requirements. For today's rule, EPA used facility-specific power
plant emissions (annual average) data to estimate increased emissions under the options
presented in the preamble to the final rule. EPA also conducted a geographical
information system (GIS) analysis of non-attainment areas and Phase II power plant
locations to identify areas of potential increased impact.
178 The preferred alternative (Option 1) required facilities to meet performance standards based on
waterbody type and proportion of flow withdrawn for cooling. Under this option, 59 facilities were
estimated to comply through the installation of cooling towers.
179 See Table 6-1 from the TDD for the 2002 Phase II proposal for the estimated incremental increase in
emissions under the 2002 preferred alternative.
180 Increased emissions are not caused by the recirculating wet cooling tower itself, but by the fuel deficit
created by the additional energy needed for operation of the towers and a loss of turbine efficiency.
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Chapter 10: Non-water Quality Impacts § 316(b) Existing Facilities Final Rule - TDD
10.1.1 Incremental Emissions Increases
Facilities that retrofit to a cooling tower will experience a reduction in efficiency, as there
is a loss of efficiency in the turbine due to the higher temperature condenser water within
the cooling water system. The fans inside the tower also require electricity to operate.
Collectively, these inefficiencies are known as the auxiliary power requirement. To
compensate for the loss of electricity generation, a facility could either operate more
frequently (if it is not already a baseload plant) or it could burn additional fuel. Both
scenarios would lead to an increase in the emission of air pollutants from the combustion
of fossil fuels.
For today's rule, EPA used a methodology similar to the one used in the 2002 proposed
rule and TDD to estimate incremental increases in emissions under each of the options
considered. The data source for the Agency's air emissions estimates of CO2, SO2, NOX,
and Hg is the EPA-developed database titled E-GRTD 2005. This database is a
compendium of reported air emissions, plant characteristics, and industry profiles for the
entire US electricity generation industry in the years 1996 through 2005. The database
relies on information from power plant emissions reporting data from the Energy
Information Administration of the Department of Energy. E-GRTD compiles information
on every major power plant in the United States and includes statistics such as plant
operating capacity, air emissions, electricity generated, and fuel consumed. This database
provided ample data for the Agency to conduct air emissions increases analyses for the
final rule. The emissions reported in the database are for the power plants' actual
emissions to the atmosphere and represent emissions after the influence of any existing
air pollution control devices.
E-GRTD, however, does not provide information on emissions of particulate matter (PM).
The data source for historic emissions rates of PM 2.5 and PM 10 is the EPA-developed
database titled National Emission Trends (NET). The NET database is an emission
inventory that contains data on stationary and mobile sources that emit criteria air
pollutants and their precursors. The NET is released every three years (e.g., 1996 and
1999) and includes emission estimates for all 50 States, the District of Columbia, Puerto
Rico, and the Virgin Islands. The database compiles information from EPA air programs
and the Department of Energy, and the information it contains for other parameters was
found to be consistent with the information found in E-GRTD 2005.
The model facility universe for each regulatory option represents those power plants that
are in scope for each option, for which some E-GRTD and/or NET data is available for
the desired parameters of CO2, SO2, NOX, Hg, PM 2.5, and PM 10. Although
manufacturing facilities are included in the universe of the final rule, there is no readily
available data on air emissions from manufacturing facilities. In addition, nuclear power
plants and facilities that already have closed-cycle cooling towers are excluded from the
model universe, as they would not retrofit to cooling towers. Furthermore, facilities that
did not have readily available air emissions data were also excluded from the model
universe. Therefore, the model facility universe for this evaluation only encompasses
those power plants for which air emissions data is available that do not already employ
cooling towers, making it a subset of the total facilities expected to be affected by the
final rule.
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§ 316(b) Existing Facilities Final Rule -TDD Chapter 10: Non-water Quality Impacts
Site-specific models for calculating air emissions increases are not appropriate for
estimating the national impact of the final rule and were not used in this analysis. In
addition, some studies have suggested that certain methods (e.g., EPA's AP-42 method
for estimating PM emissions from cooling towers) may overstate air emissions from
recirculating wet cooling towers (SWRCB 2010). One approach to generating an upper
bound estimate of air emissions increases at facilities included in the model universe
under each option is presented in Tables 10A-1 (Proposal Option 2) and 10A-2 (Proposal
Option 3) in the Appendix to this chapter. These tables represent facility-specific air
emissions increases and are based on the estimated energy penalty for each facility, the
facility's historic average electricity generation level, and its average historic emission
rates.181 The estimated incremental increases in emissions are not reported for facilities
already employing (or partially employing) cooling towers, nuclear and retired facilities,
and those facilities for which data is not available. Note that the discussions below on
greenhouse gases do not reflect recent or proposed regulations for limiting greenhouse
gas emissions, as the data is reported for 2005 and thus reflects operations prior to 2004.
These data predate the implementation of recent air rules; therefore, EPA expects that, in
most cases, these data do not reflect emissions after installation of scrubbers and other air
pollution control equipment.
Carbon dioxide
Carbon dioxide is not a criteria pollutant under the National Ambient Air Quality
Standards (NAAQS). Carbon dioxide is, however, a pollutant of concern on a global
scale, as it is a greenhouse gas. In March 2012, EPA proposed a regulation that would
limit carbon dioxide emissions from new power plants to 1,000 pounds per megawatt-
hour. Several states, including California, Oregon, Washington, Montana and Illinois,
currently have rules for limiting carbon dioxide emissions from electric generators. Nine
The nine Northeastern states, Connecticut, Delaware, Maine, Maryland, Massachusetts,
New Hampshire, New York, Rhode Island, and Vermont are currently participating in the
Regional Greenhouse Gas Initiative which is a regional cap-and-trade program that limits
carbon dioxide emissions from electric generators. Similar systems are in development in
the West and Midwest. The cap and trade programs ensure that total emissions from all
covered entities fall below a cap that typically declines over time; however, it does not
mandate limits for individual entities, as is the case for performance standards (Pew
Article 2010).
Sulfur Dioxide
Sulfur dioxide is one of the most regulated pollutants in the U.S. and is one of the criteria
pollutants under NAAQS. Electricity generation is the highest-contributing source of
sulfur dioxide emissions in the United States. Regional monitoring levels are generally
below NAAQS threshold levels, except for events at three monitoring sites in Hawaii that
have been suggested to be attributed to volcanic activity and therefore, as exceptional
events, are not considered for regulatory purposes. Annual average ambient sulfur
dioxide concentrations, as measured at area-wide monitors, have decreased by more than
181 Historic generation rates were obtained from E-GRID 2005. Historic emissions rates were obtained from
E-GRID 2005 and NET.
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Chapter 10: Non-water Quality Impacts § 316(b) Existing Facilities Final Rule - TDD
70 percent since 1980. Currently, the annual average sulfur dioxide concentrations range
from approximately 1-6 parts per billion, which is well below the quantities expected to
affect human health (EPA 2010a).
Nitrogen dioxide
Nitrogen dioxide is one of the most regulated pollutants in the U.S. and is one of the
criteria pollutants under NAAQS. Although electricity generation is the third-highest
contributor to nitrogen dioxide emissions in the Unites States, regional monitoring levels
have been well below NAAQS threshold levels, so no U.S. counties (as of the summary
data collected at the national level through 2008) have been considered to be out of
attainment in the past decade for this parameter (EPA 201 Ob). Annual average ambient
nitrogen dioxide concentrations, as measured at area-wide monitors, have decreased by
more than 40 percent since 1980. Currently, the annual average nitrogen dioxide
concentrations range from approximately 10-20 parts per billion (ppb), which is not
considered to be a sufficient quantity to affect human health (EPA 2010c).
EPA expects nitrogen dioxide concentrations will continue to decrease in the future as a
result of a number of mobile source (the highest contributing source of nitrogen dioxide
emissions in the United States) regulations that are taking effect in the past few years.
Nitrogen dioxide is, however, one of the two molecules (with volatile organic compounds
[VOCs] being the other) that facilitates the formation of ground level ozone, which is
also a criteria pollutant and often exceeds the NAAQS criteria.182 Therefore, in ground-
level ozone non-attainment areas, point sources of nitrogen dioxide and VOCs are tightly
controlled. In addition, more stringent controls for nitrogen dioxide and VOCs are
expected in the future (Lavalee 2008).
Mercury
Mercury is not one of the criteria pollutants under NAAQS, but is known to cause human
health impairments. However, mercury is typically not a pollutant that is sampled by the
regional monitoring equipment in each Air Quality Control Region. Many states have
begun efforts to inventory sources of mercury but have yet to set limits. Some states have
emissions limits, but most are sufficiently high that they are not exceeded (Lavalee
2008).
Particulate Matter
PM is one of the criteria pollutants regulated under NAAQS. It is measured as PM 2.5,
particles that are 2.5 micrometers in diameter and smaller, and PM 10, particles that are
10 micrometers in diameter or smaller. These are regulated pollutants because particles
smaller than 10 micrometers can, once inhaled, enter the lungs and cause serious health
effects. Electricity generation is the fourth highest-contributing source of PM in the
United States, both at the PM 2.5 and PM 10 levels (EPA 2010d).
Regional monitoring levels for PM 10 have generally been below NAAQS threshold
levels; PM 2.5 monitoring, however, has consistently indicated many areas of periodic
182 Seethe maps in Appendix 10A-3; ozone is the pollutant with the largest number of non-attainment
areas.
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§ 316(b) Existing Facilities Final Rule -TDD Chapter 10: Non-water Quality Impacts
nonattainment of NAAQS standards since national regional monitoring began in 1999.
Even though annual average ambient PM has been steadily decreasing across the country,
PM remains as a potentially significant environmental and human health concern (EPA
2010d).
As discussed in DCN 10-6954, increased emissions would be approximately 60 tons per
year if all drift is PMio. This document also noted minor drift management issues onsite
at facilities using salt water cooling towers and no negative consequences off-site.
Total Emissions Increases
Emission increases consist of: (1) stack emissions from increased burning of fuel as a
result of the energy penalty for retrofitting to a cooling tower (the turbine backpressure
penalty); (2) stack emissions from increased burning of fuel as a result of the auxiliary
power requirement for operating the cooling tower; (3) cooling tower emissions including
water vapor (drift) and PM. For the options under which no facilities are required to
retrofit to wet cooling towers (Proposed Options 1 and 4), there would be no incremental
increase in air emissions. For those options under which EPA assumes a subset of
facilities would retrofit to wet cooling towers, EPA expects an increase in the total air
emissions. This increase excludes those facilities already employing cooling towers. As
seen in Appendix A to this chapter, the estimated energy penalty for each facility would
result in an increase over each facility's historic emissions rates for average electricity
generation levels.
Cooling tower paniculate emissions can be mitigated through the use of drift
eliminators—shaped materials that collect small water droplets as they exit the tower.
Drift eliminators are capable of reducing drift to 0.0005 percent of the circulating water
volume, or approximately 0.5 gallons per 100,000 gallons of flow (OPC 2008). EPA
included capital costs for drift eliminators for all facilities expected to retrofit to wet
cooling towers.
In addition, some number of fossil fuel-burning power plants might close due to the
additional regulatory burden imposed the Existing Facility rule. See the EA for more
information. Those facilities projected to close are (in general) the oldest, least efficient,
and highest air emissions-producing sources. Therefore, the estimate of increased air
emissions associated with the retrofit to wet cooling towers reflects an upper bound
estimate.
Total Emissions Reductions
EPA believes projected total emissions from retrofits to cooling towers using currently
available data (Appendix A) reflect an upper bound estimate for several reasons. The
IPM modeling used in EPA's economic analysis indicates baseload generating units and
units forecast to continue production are generally comprised of the most efficient (and
therefore the lowest emitting) units, resulting in a potential reduction in total air
emissions. For example, the baseline closures are coal-fired units that are among the top
50 highest SC>2 emitting plants (Sourcewatch, DCN 10-6857). In addition, the current
emissions rate calculations do not reflect full implementation of the most recent air rules
or pending actions on greenhouse gases and global climate change. For example, the
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Chapter 10: Non-water Quality Impacts § 316(b) Existing Facilities Final Rule - TDD
2005 Clean Air Interstate Rule (CAIR) will reduce 2003 NOx level by 53 percent in 2009
and 61 percent in 2015. Similarly, 2003 SOx levels would be reduced by 45 percent in
2010 and 57 percent in 2015. The Utility Maximum Achievable Control Technology rule
would require utilities to install controls to reduce mercury emissions by 91 percent.
Since the actual emissions data used in EPA's analysis does not reflect full
implementation of these air rules, and since in many cases technologies to reduce
emissions have yet to be installed, both the baseline and any potential increase in
emissions are overstated. Finally, the latest tower fill materials and other cooling tower
technology improvements provide increases in cooling capacity. In some cases, cooling
towers provide cooling water at lower temperatures than available from the source water,
particularly during the summer months, resulting in lower turbine back pressure in the
summer when maximum power generation is desired. Despite these conservative
estimates, EPA concludes there is the potential for an increase in total emissions. At this
time, EPA lacks adequate data to conduct a more precise analysis of incremental
emissions.
10.1.2 CIS Analysis
As part of its review of the analyses of increased emissions, EPA conducted a GIS
analysis of expected pollutants from potentially affected facilities. Specifically, EPA
created maps with the locations of all power plants that would have been covered under
the 2004 Phase II rule overlaid with maps of non-attainment area designations for 2010
1 81
for the various criteria air pollutants. At the time of the analysis, EPA did not have
national data for manufacturers; therefore, manufacturers were excluded from this
analysis.
EPA created maps to identify non-attainment areas for the following pollutants:
• Carbon monoxide (CO)
• Lead (Pb)
• Particulate matter (PM10 and PM2.5)
• Ozone
• Sulphur dioxide (802)
Maps for each pollutant are found in Appendix 10A-3. For most pollutants, Phase II
power plants are generally located in areas that meet the NAAQS standards (i.e., are in
attainment).184 There are, however, a significant number of facilities are located in
nonattainment areas for PM2.5 and Ozone. Exhibits 10-1 and 10-2 show the data from
the maps in a tabular format.
183 EPA used data layers from the EPA Office of Air and Radiation's AQS Database. These data layers
reflect attainment status for criteria pollutants under NAAQS. Generally, concentrations of air pollutants
are monitored in the ambient air, usually on a county-by-county level. Areas that exceed the pollutant
levels specified by NAAQS can be classified by EPA as non-attainment. See www.epa.gov/air/criteria.html
for more details.
184 Facilities in Alaska and Hawaii are not shown; these states are in attainment for all criteria pollutants.
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§ 316(b) Existing Facilities Final Rule -TDD
Chapter 10: Non-water Quality Impacts
Exhibit 10-1. Phase II facilities in non-attainment areas (by pollutant)
Pollutant
Carbon monoxide (CO)
Lead
PM10
PM2.5
Ozone (8 hr)
Sulphur dioxide (SO2)
Number of facilities
0
1
7
145
174
2
Exhibit 10-2. Phase II facilities in non-attainment areas (by EPA Region)
Pollutant
Carbon monoxide (CO)
Lead
PM10
PM2.5
Ozone (8 hr)
Sulphur dioxide (SO2)
Number of facilities by EPA Region
I
0
0
0
4
23
0
II
0
0
0
22
33
0
III
0
0
0
37
28
1
IV
0
0
0
18
11
0
V
0
0
0
53
40
0
VI
0
0
0
0
20
0
VII
0
1
0
4
0
0
VII
0
0
0
0
3
1
IX
0
0
7
7
16
0
X
0
0
0
0
0
0
The geographic analysis shows that there not many Phase II power plants for which
nonattainment of carbon monoxide, lead, PM 10, and sulphur dioxide NAAQS standards
is likely to be a concern. There are some areas, however, where additional emissions of
PM 2.5 and ozone (8-hr) could be a concern, particularly for facilities several in EPA
Regions where there are significant numbers of Phase II facilities in non-attainment
areas.
10.2 Vapor Plumes
In 2002, EPA's assessment of vapor plumes resulting from a retrofit from once-through
cooling to recirculating wet cooling towers showed that these plumes have the potential
for exacerbated fogging and icing. High levels of fogging and icing have the potential to
create dangerous conditions for local roads and for air and water navigation. There are
some cases of wet cooling towers being built in close proximity to airports and highways
that could be susceptible to fogging and icing problems. In these cases, however, the
potential for dangerous conditions were mitigated by the installation of plume abatement
technologies during the construction of the cooling towers.
Plume abatement might also be necessary at certain types of locations, including
situations in which local residents or governments object to the visible plume, as it may
detract from a view that is valued by the community, or if the plume might create safety
problems such as reduced visibility on nearby roadways or icing on roads and bridges.
EPA included plume abatement technologies in its cost estimates for one-fourth of the
facilities expected to retrofit to wet cooling towers. For adding plume abatement
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technology to a conventional mechanical draft cooling tower, the total cost of the tower
component is estimated to increase by a factor of 2.0-3.5 with a 10 percent increase in the
energy requirement and a 50 percent to 100 percent increase in non-energy O&M (see
DCN 10-6652). A number of site-specific factors come into play to determine the
selection of technology, but appropriate assumptions for estimating national-level
compliance costs can be made regarding the impacts of these abatement technologies to
the overall cost of the retrofit. A full discussion of the costing methodology and
assumptions used for the Existing Facility rule is presented in Chapter 8 of this TDD.
10.3 Displacement of Wetlands or Other Land Habitats
As described in the 2002 proposed Phase II TDD, mechanical draft cooling towers can
require land areas of up to 1.5 acres for an average-sized new cooling tower.185 In 2002,
the Agency concluded that existing Clean Water Act section 404 programs would more
than adequately protect wetlands and habitats for these land uses. EPA also determined
that the displacement of wetlands on an industrial site such as a large existing power
plant is not a probable outcome of cooling tower construction at most facilities. EPA does
not expect habitat displacement to be a significant problem for most facilities. EPA
believes for the final rule that existing Federal, State, and local programs for maintaining
and restoring wetlands are adequate to protect wetlands and no new analyses were
conducted.
10.4 Salt or Mineral Drift
As described in the 2002 proposed Phase II TDD, the operation of cooling towers in
either brackish or salt water environments can release water droplets containing soluble
salts, including sodium, calcium, chloride, and sulfate ions. Salt drift may also occur in
freshwater systems that operate recirculating systems at very high levels of concentration,
but based on EPA's site visits and the higher O&M costs of operating at the highest
cycles of concentration, EPA expects this is unlikely to occur at most facilities. Salt drift
from towers may be carried by prevailing winds and settle onto soil, vegetation, and
waterbodies. Under normal conditions drift does not carry very far from the originating
source and would require sustained high winds and high humidity to reach distances of
several hundred feet in any significant quantity (SWRCB 2010). In addition, drift-
reducing technologies called drift eliminators are often used to minimize salt and mineral
drift. (Also see the above discussion of parti culate matter and EPA's assignment of drift
eliminators.) A review of GIS mapping of nuclear facilities shows the safety perimeter
and setback distances at nuclear facilities are large enough that drift reaching and settling
on neighboring properties is highly unlikely. Additional site-specific studies at Chalk
Point and St. Johns (Maulbetsch) suggest the impacts of drift are limited to the facility
property. As such, EPA does not expect drift to be a significant problem for most
facilities under any of the cooling tower options.
185 Size of "average" cooling tower is based on technology and cost assumptions used in developing the
2002 proposed Phase II rule.
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§ 316(b) Existing Facilities Final Rule -TDD Chapter 10: Non-water Quality Impacts
10.5 Noise
Noise from mechanical draft cooling towers is generated by falling water inside the
towers plus fan or motor noise or both. However, power plant sites generally do not result
in off-site levels of noise more than 10 dB(A) above background (NRC 1996). The
amount of noise abatement required is a function of both the local community noise code
and the distance from the tower to the nearest sound receptor that must meet the specified
noise code. Noise abatement costs will be highest if a tower must be located near areas
with highly restrictive noise codes, such as residential areas.
Noise abatement features are an integral and inexpensive component of modern cooling
tower designs. (See the 2002 proposed TDD, Appendix B, Charts 2-1 through 2-6 for a
comparison of low-noise tower costs and other types of tower modifiers.) Facilities that
make use of cooling towers might expect the typical noise level to be approximately 70
dB within 50 feet of the tower (SPX 2009).186 Because sound levels diminish
approximately 5 dB per doubling of distance, and 55 dB falls between the sound level of
rainfall and normal conversation (and therefore would not be considered noise pollution),
a buffer of 400 feet would suffice for noise abatement at most sites. In addition, EPA's
"Protective Noise Levels" guidance found that ambient noise levels of 55 dB was
sufficient to protect public health and welfare and, in most cases, did not create an
annoyance (EPA 1978). As for noise pollution at the site itself, the New York State
Department of Environmental Conservation's "Assessing and Mitigating Noise Impacts"
policy states that 60-70 dB is the beginning of the threshold for annoyance in non-
industrial sites and that noise can exceed 65 dB (and up to 79 dB) in commercial or
industrial sites. A common goal is to keep new noise sources from increasing the overall
noise levels by 5-10 dB. Given that noise is measured on a logarithmic scale, adding a
cooling tower that operates with a sound level of approximately70 dB will be unlikely to
add a significant level of noise to an already noisy industrial site (NYDEC 2000). Given
that noise appears to dissipate relatively quickly (and the fact that many industrial sites
are large and a 400 foot buffer would not be a significant limitation), effects from noise
are not expected to be significant at most sites. There will certainly be some sites that
require noise mitigation, but the number of sites is likely to already be represented by the
site analyses for plume and population density. In addition, this issue is often a matter of
adverse public reactions to the noise and not environmental or human health (i.e.,
hearing) impacts. The NRC adds further, "[njatural-draft and mechanical-draft cooling
towers emit noise of a broadband nature...Because of the broadband character of the
cooling towers, the noise associated with them is largely indistinguishable and less
obtrusive than transformer noise or loudspeaker noise."
The cost contribution of low noise fans comprises a very small portion of the total
installed capital cost of a retrofitted cooling system (on the same order as drift
elimination technologies). Where noise abatement materials maintenance costs are higher
(such as for larger towers), O&M costs should be commensurately reduced. Thus, the net
effect of this noise abatement technology design on cooling tower O&M costs is expected
to be minimal. In order to account for the potential increased in costs, EPA assumed that
25 percent of cooling towers would require increased costs to account for noise and
186 For additional technical discussion of noise mitigation, please see DCN 10-6652.
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Chapter 10: Non-water Quality Impacts § 316(b) Existing Facilities Final Rule - TDD
plume abatement. EPA included additional costs for noise abatement at approximately 25
percent of existing facilities; see Chapter 8 of the TDD and DCNs 10-6671 and 6672.
EPA found the costs of such controls to be nominal, therefore EPA concludes that the
issue of noise abatement is not critical to the evaluation of the environmental side effects
of cooling towers. As such, EPA does not expect noise abatement to be a significant
problem for most facilities.
10.6 Solid Waste Generation
Recirculation of cooling water increases the volume of solid wastes generated because
some facilities (including most manufacturers) treat the cooling tower blowdown in a
wastewater treatment system before discharge, and the concentrated pollutants removed
from the blowdown add to the amount of wastewater sludge generated by the facility. For
facilities operating cooling towers in brackish or saline waters, the concentration of salts
within the tower and blowdown are a primary design factor. As such, these systems can
have elevated salt concentrations. However, the concentration of salts is generally a
treatable condition for blowdown from towers. In general, manufacturers tend to have
systems in place for treating this type of solid. EPA does not expect the impacts of solids
waste disposal to be a significant problem and did not further evaluate impacts from
solids waste disposal for the Existing Facility rule.18?
10.7 Evaporative Consumption of Water
Cooling tower operation is designed to result in a measurable evaporation of water drawn
from the source water. Depending on the size and flow conditions of the affected
waterbody, evaporative water loss can affect the quality of aquatic habitat and
recreational fishing. According to NUREG-1437 (NRC 1996), "water lost by evaporation
from the heated discharge of once-through cooling is about 60 percent of that which is
lost through cooling towers." NUREG-1437 goes on to further state that "with once-
through cooling systems, evaporative losses... occur externally in the adjacent body of
water instead of in the closed-cycle system." Therefore, evaporation does occur due to
heating of water in once-through cooling systems, even though the majority of this loss
happens downstream of the plant in the receiving waterbody due to the evaporation in the
heated effluent plume.
EPA acknowledges that evaporative losses from closed-cycle cooling towers are likely
greater than those from once-through cooling systems for a given site. Withdrawal and
subsequent return of once-through cooling water to a large waterbody such as an ocean is
likely to show the least amount of downstream evaporation. On the other hand,
withdrawal of a majority of a river and the subsequent return of heated water can be
expected to approach the same evaporative losses as a cooling tower sized for the same
heat load. Cumulative effects such as multiple users of the waterbody will amplify the
187 EPA assumed no incremental costs for treatment of blowdown, as the issue is expected to be minor for
most facilities. For example, facilities on brackish waters are already discharging to waters with elevated
TSS. Additionally, many facilities (particularly manufacturers) already have wastewater treatment
capabilities in place.
10-10
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§ 316(b) Existing Facilities Final Rule -TDD Chapter 10: Non-water Quality Impacts
effect. When considered at the national level, EPA concludes the average rate of
evaporation can increase by a factor of 1.5 to 2 in closed-cycle systems. This conclusion
is consistent with research conducted by NUREG-1437 and the Electric Power Research
Institute (EPRI) that concluded that losses in closed-cycle systems are approximately 60-
80 percent greater (EPRI 2002).
The differences in evaporative losses are minimal in terms of gallons lost and in most
cases are minor compared to river flow. In areas where water resources are limited (e.g.,
the desert southwest or the recently drought-stricken southeast), once-through cooling
may not be a prudent option for new facilities and it may be a liability for existing
facilities. Some facilities would not be able to withdraw sufficient volumes of water for
once through cooling. These same facilities could withdraw sufficient makeup water for a
cooling tower. EPA found this in site visits where several facilities retrofitted to closed-
cycle cooling in spite of drought conditions (see, e.g., the site visit report for
McDonough). Similarly, for facilities located on smaller waterbodies, evaporative losses
from once-through cooling will be higher since the effluent comprises a larger percentage
of the receiving stream, won't mix as quickly, and will remain heated longer, leading to
additional evaporation. Smaller receiving streams are also more likely to be affected by
thermal discharges from the perspective of 316(a), which requires that the discharge not
affect the "balanced indigenous population."
Dry cooling and hybrid (wet/dry) cooling are available technologies that reduce
evaporative losses. Dry cooling systems require virtually no water withdrawals and
hybrid systems consume about 15 percent less water through evaporation. EPA's record
shows these systems for reducing evaporative losses have been available and
demonstrated for over 30 years.
While EPA did not attempt to identify or quantify the meteorological effects, the water
vapor in the evaporative plumes does not simply disappear; it will be incorporated into
the atmosphere and may return to the original watershed in the form of precipitation.
Finally, cooling water withdrawals are a very small component of consumptive uses
nationwide. As noted in EPA's Closed-cycle Cooling Systems for Steam-electric Power
Plants: A State-of-the-art Manual (DCN 10-6845F), consumptive water uses by the steam
electric sector was 1.2 percent of consumptive uses nationwide in 1975; agriculture was
85 percent, drinking water was 7 percent and mining was 7 percent. The Nuclear Energy
Institute presented similar data, noting that a closed-cycle power plant typically consumes
23 gallons of water per day per household served with electricity, while the same average
household uses 94 gallons per day for domestic uses.
10.8 Thermal Effluent
EPA notes that section 316(a) of the CWA provides EPA the authority to deal with
thermal effects and that technologies used to meet 316(b) standards may have impacts
and/or benefits for meeting 316(a) requirements. Given the lack of specific data on the
impact of thermal effects, EPA did not conduct a formal analysis or quantify the impacts
of thermal effluent discharges, although the conversion to cooling towers clearly presents
a significant reduction in the discharge of heat, a regulated pollutant. EPA did conduct an
10-11
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Chapter 10: Non-water Quality Impacts § 316(b) Existing Facilities Final Rule - TDD
overview of thermal discharge data for a sampling of electric generator facilities in the
Permit Compliance System, but excluded data from facilities that already use closed-
cycle cooling. EPA has calculated that mechanical draft evaporative cooling towers are
an effective technology for reducing the volume of surface water withdrawn for cooling
and can reduce once-through intake flows by 93 percent to 99 percent depending on
operating conditions such as the temperature rise and the cycles of concentration.
10.9 References
California Ocean Protection Council (OPC). 2008. California's Coastal Power Plants:
Alternative Cooling System Analysis. Available at
http://www.opc.ca.gov/webmaster/ftp/project_pages/OTC/engineering%20studv/C
A_Power_Plant_Analysis_Complete.pdf.
California State Water Resources Control Board and California Environmental Protection
Agency (SWRCB). 2010. Water Quality Control Policy on the Use of Coastal and
Estuarine Waters for Power Plant Cooling Final Substitute Environmental
Document. SeeDCN 10-6860.
Electric Power Research Institute (EPRI). 2002. Water & Sustainability (Volume 3): U.S.
Water Consumption for Power Production—The Next Half Century. EPRI, Palo
Alto, CA: 2002. 1006786.
Energy Information Administration. 2011. Annual Energy outlook 2011.
Environmental Protection Agency (EPA). 2010a. Sulfur Dioxide. Available at
http://www.epa.gov/air/sulfurdioxide/.
Environmental Protection Agency. 201 Ob. Nitrogen Dioxide Information. Available at
http://www.epa.gov/oaqps001/greenbk/nindex.html.
Environmental Protection Agency. 2010c. Nitrogen Dioxide. Available at
http://www.epa.gov/airquality/nitrogenoxides/.
Environmental Protection Agency. 2010d. Particulate Matter. Available at
http://www.epa.gov/air/particlepollution/.
Environmental Protection Agency. 1978. Protective Noise Levels. EPA 550/9-79-100
November 1978.
Lavalee, Tim. 2008. Personal communication with Kelly Meadows, Tetra Tech.
September 16, 2008.
New York Department of Environmental Conservation (NYDEC). 2000. Assessing and
Mitigating Noise Impacts. Available at
http://www.dec.ny.gov/docs/permits ei operations pdf/noise2000.pdf
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§ 316(b) Existing Facilities Final Rule -TDD Chapter 10: Non-water Quality Impacts
Nuclear Energy Institute (NET). 2010. Water Use and Nuclear Power Plants. May 2010.
See DCN 10-6874.
Nuclear Regulatory Commission (NRC). 1996. Generic Environmental Impact Statement
for License Renewal of Nuclear Plants. NUREG-1437 Vol. 1. Available
at http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/srl437/
SPX Cooling Technologies (SPX). 2009. Cooling Tower Fundamentals. Ed. John
Hensley. SPX Cooling Technologies, Overland Park, Kansas. Available at
http://spxcooling.com/pdf/Cooling-Tower-Fundamentals.pdf
10-13
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10-14
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§ 316(b) Existing Facilities Final Rule -TDD
Chapter 10: Appendix
Appendix to Chapter 10: Non-water Quality Impacts
10A.O Air Emissions Data for Proposal Option 2
EPA assumed that the 136 power plants withdrawing 125 mgd or more for which air emissions
data is available would retrofit to recirculating wet cooling towers (not including those facilities
already employing cooling towers). This table represents facility-specific increases; the data are
based on the estimated energy penalty for each facility, the facility's historic average electricity
generation level, and its average historic emission rates.
Unit
1
2
3
4
5
6
1
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
Total increase in
Annual CO2(tons)
47,062.09
25,758.85
309.09
17,646.79
-
14,022.39
26,508.32
37,197.49
17,547.14
5,114.76
3,427.09
45,620.40
127.92
9,982.55
5,883.26
214,619.09
16,853.90
24,876.82
41,790.45
38,635.50
15,647.31
112,328.50
2,957.93
41,808.74
9,977.82
15,885.15
89,591.31
41,438.63
5,627.19
148.85
6,955.23
51,350.22
6,312.31
551.25
98,796.63
128,643.03
104,088.03
3,316.93
29,456.81
Total increase
in Annual SC>2
(tons)
462.89
182.78
0.07
174.67
-
72.49
0.15
66.09
120.60
0.27
44.84
181.72
0.16
8.94
1.17
41.72
232.41
106.21
349.91
551.81
256.38
273.52
0.32
542.94
2.22
11.59
106.55
107.78
0.03
0.18
15.62
238.61
0.03
0.03
209.09
664.68
451.36
0.04
152.77
Total increase
in Annual NOX
(tons)
103.63
90.66
1.23
47.89
-
38.80
7.26
92.44
33.08
13.03
7.85
83.39
0.20
15.78
4.81
64.54
50.84
40.74
163.05
149.18
55.88
51.91
1.53
97.13
4.40
25.09
82.10
66.59
3.91
0.23
12.49
128.75
1.20
0.47
276.70
209.76
456.50
3.72
57.76
Total
increase in
Annual Hg
(Ibs)
2.71
1.93
0.70
0.52
1.12
1.38
0.17
0.92
0.20
1.21
4.89
0.58
14.10
1.92
3.80
2.41
1.25
2.31
5.53
2.28
0.87
Total increase
in Annual
PM2.5
(tons)
21.68
28.65
12.49
5.10
0.04
8.29
2.26
9.87
-
1.08
27.71
-
-
-
-
17.41
3.88
5.96
10.84
21.15
33.78
2.30
10.45
6.75
0.32
-
0.93
11.88
0.25
0.22
13.93
24.91
0.32
4.31
Total increase
in
AnnualPMIO
(tons)
26.24
32.96
15.62
6.39
0.04
23.12
2.26
5.49
13.32
-
1.36
28.22
-
-
-
-
19.21
4.42
7.86
12.31
27.82
38.56
2.37
17.70
8.98
0.32
-
1.22
16.62
0.25
0.22
18.60
30.44
3.02
0.32
5.03
10A-1
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Chapter 10: Appendix
§ 316(b) Existing Facilities Final Rule - TDD
Unit
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
Total increase in
Annual CO2(tons)
125,430.47
24,843.22
100,889.85
28,645.06
46,639.02
94,162.18
43,849.02
215,723.35
26,284.78
83,873.34
64,350.01
149,318.10
54,419.06
-
73,506.91
33,331.51
14,929.32
13,141.93
71,845.14
465,996.64
126,653.35
112,406.67
84,840.09
120,257.80
109,150.28
31.63
86,409.28
29,407.30
73,475.45
172,555.52
82,741.51
154,976.34
47,713.04
151,309.02
21,922.20
11,196.38
41,876.76
14,759.60
55,712.41
179,421.18
212,738.66
189,651.05
65,809.54
36,324.07
15,718.64
191,789.22
20,216.39
239,320.63
13,326.31
1.64
232,197.58
247,340.42
Total increase
in Annual SC>2
(tons)
1,212.29
122.04
387.50
571.47
353.01
558.07
179.11
1,736.65
0.17
398.21
445.24
697.85
13.21
-
461.34
209.74
0.09
4.91
501.61
1,351.75
126,653.35
2,034.33
135.58
169.46
495.24
-
396.89
50.62
589.60
1,356.09
996.05
508.53
106.61
972.71
0.11
1.80
0.23
23.50
149.93
1,251.65
420.00
1,470.08
378.27
0.30
0.04
857.49
0.11
646.69
1.13
-
2,787.33
658.21
Total increase
in Annual NOX
(tons)
180.61
139.03
117.70
55.81
63.12
171.88
75.57
475.96
8.25
129.19
143.20
287.80
32.41
-
129.32
100.16
6.66
14.04
93.99
557.28
208.98
190.48
277.76
442.70
326.70
0.01
118.42
36.82
156.50
240.19
104.63
243.02
71.76
123.17
26.27
22.64
11.94
18.14
57.41
234.68
172.87
333.25
156.37
3.55
0.87
448.65
15.36
278.35
19.61
-
415.09
521.08
Total
increase in
Annual Hg
(Ibs)
0.69
5.34
1.51
5.06
0.69
13.13
3.63
2.66
4.18
-
4.77
2.07
3.47
8.93
11.26
4.89
2.39
6.48
4.34
4.77
9.37
9.32
9.37
6.75
8.64
33.94
5.63
6.89
7.72
8.33
13.43
Total increase
in Annual
PM2.5
(tons)
65.05
3.95
36.94
25.13
4.56
6.68
5.78
42.76
-
15.54
18.85
22.37
1.33
25.35
11.34
1.33
1.54
25.92
53.92
109.14
88.06
19.21
7.14
0.04
17.30
7.25
16.59
104.11
33.03
16.33
8.22
8.33
2.51
1.83
1.40
1.08
8.36
59.34
37.44
56.97
-
3.91
16.62
1.97
13.14
0.86
0.39
82.10
22.80
Total increase
in
AnnualPMIO
(tons)
71.23
3.95
62.39
26.31
6.14
15.33
10.05
46.92
-
30.98
23.37
23.30
1.33
29.76
14.04
1.33
1.54
29.26
72.16
109.21
91.90
8.69
28.00
7.65
0.04
17.91
7.25
21.11
150.21
38.34
21.76
10.45
8.33
2.51
1.83
1.40
1.26
11.74
66.27
46.02
58.66
-
3.91
31.56
1.97
22.08
0.86
1.22
91.51
29.51
10A-2
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§ 316(b) Existing Facilities Final Rule -TDD
Chapter 10: Appendix
Unit
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
TOTAL
Total increase in
Annual CO2(tons)
133,651.85
181,036.27
3,492.64
318,582.91
323,849.40
193,434.16
150,672.13
40,719.17
223,448.67
8,555.80
299,311.78
176,410.50
74,228.78
188,729.21
10,802.33
72,148.92
141,882.58
17,576.18
430,167.67
303,341.43
11,130.96
492,439.33
298,837.98
133,838.18
318,262.91
552,928.93
137,532.97
280,145.79
361,319.89
279,371.93
620,697.97
319,700.75
510,476.19
49,502.38
102,624.92
934,864.48
395,263.14
2,957.39
17,817.23
236,556.23
627,946.34
650,275.69
743,242.36
606,115.85
154,739.88
18,360,926.72
Total increase
in Annual SC>2
(tons)
1,528.41
1,093.83
0.32
932.07
3,755.21
2,397.29
79.21
84.37
1,630.73
0.04
755.68
503.87
355.64
437.10
0.05
115.46
860.39
0.09
1,048.36
3,017.74
0.06
1,926.14
2,685.20
1,154.35
1,397.99
3,825.75
748.11
1,444.56
408.45
1,167.42
1,992.54
2,680.25
3,475.57
0.25
1.38
2,975.95
1,234.25
0.01
0.09
463.21
2,861.15
3,959.99
1,985.06
627.29
1,181.66
214,741.34
Total increase
in Annual NOX
(tons)
413.44
345.40
2.92
198.31
500.13
323.89
25.52
65.79
298.85
1.20
181.28
247.99
224.72
166.01
0.79
168.23
315.13
4.39
245.26
464.77
13.98
691.02
437.93
265.87
586.15
903.42
317.88
393.03
857.18
382.51
342.07
812.09
733.05
13.41
251.19
651.78
651.74
3.52
29.71
166.69
507.50
1,270.78
178.47
975.98
356.45
26,591.23
Total
increase in
Annual Hg
(Ibs)
9.32
8.97
21.10
20.83
7.39
9.66
12.00
9.53
27.27
1.89
5.79
27.63
36.96
18.58
23.38
4.79
14.88
22.55
7.66
5.65
9.55
32.76
18.87
19.32
56.86
16.94
10.06
77.30
45.12
20.97
9.47
873.51
Total increase
in Annual
PM2.5
(tons)
74.03
3.95
0.14
28.43
168.05
100.77
7.04
6.00
54.21
10.77
22.33
16.48
17.77
3.91
19.96
65.19
1.69
44.05
98.33
4.38
90.54
75.71
77.87
103.57
232.81
57.19
62.47
53.17
35.43
25.49
177.96
5.89
14.25
90.00
88.53
-
1.08
11.99
105.22
101.06
94.78
3,653.08
Total increase
in
AnnualPMIO
(tons)
74.82
7.83
0.18
34.54
219.49
108.27
7.43
6.79
63.36
10.95
27.97
22.55
28.86
3.95
38.41
87.74
1.72
80.74
117.18
4.38
107.48
80.85
80.20
115.13
258.30
58.05
91.04
60.81
62.29
36.94
205.31
5.89
14.25
102.28
113.80
-
1.08
12.28
171.57
108.63
129.49
4,495.65
10A-3
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Chapter 10: Appendix
§ 316(b) Existing Facilities Final Rule - TDD
10A. 1 Air Emissions Data for Proposal Option 3
EPA assumed that all 167 power plants for which data is readily available would retrofit to
recirculating wet cooling towers. This table represents facility-specific increases; the data are
based on the estimated energy penalty for each facility, the facility's historic average electricity
generation level, and its average historic emission rates.
Unit
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
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
Total increase
in Annual CO2
(tons)
9,603.30
-
2,188.80
-
289,758.55
91.61
-
-
5,488.98
121,821.75
20,355.14
28,787.97
1,496.18
5,718.97
-
39,262.67
321.24
15,690.00
15,871.58
11,470.36
3,891.51
2,842.32
16,719.07
277.81
25,010.72
24,760.44
39,923.88
-
6,312.31
2,136.46
2,974.80
47,062.09
25,758.85
309.09
17,646.79
-
14,022.39
26,508.32
37,197.49
17,547.14
5,114.76
Total increase
in Annual SO2
(tons)
89.47
-
30.98
-
936.94
-
-
-
0.05
382.08
23.25
397.72
0.41
0.03
-
0.60
0.01
110.42
333.43
235.69
16.56
14.14
97.23
0.01
156.42
85.60
191.76
0.01
0.03
30.26
7.91
462.89
182.78
0.07
174.67
-
72.49
0.15
66.09
120.60
0.27
Total increase
in Annual NOX
(tons)
41.47
37.27
9.56
-
210.06
0.02
25.95
23.40
1.45
495.89
26.52
53.05
2.84
4.17
0.11
2.43
0.52
29.83
39.55
25.22
7.37
4.19
56.40
0.45
52.03
43.78
85.00
33.98
1.20
6.25
4.96
103.63
90.66
1.23
47.89
-
38.80
7.26
92.44
33.08
13.03
Total increase
in Annual Hg
(Ibs)
8.21
2.63
12.83
2.32
5.06
3.33
0.62
1.85
0.23
0.71
1.69
0.63
0.71
1.55
1.80
0.76
2.71
1.93
0.70
0.52
1.12
1.38
Total increase
in Annual
PM2.5
(tons)
-
-
0.07
18.92
-
-
-
0.86
14.93
1.01
30.98
-
19.49
-
-
-
-
19.57
0.65
-
-
3.23
8.26
11.34
-
0.04
-
0.25
21.68
28.65
12.49
5.10
0.04
8.29
2.26
9.87
-
Total increase
in Annual
PM10
(tons)
0.04
-
0.25
0.22
22.08
-
-
-
0.86
14.93
1.33
33.03
-
22.04
-
-
-
-
20.10
0.65
-
-
5.85
14.75
14.11
-
0.04
-
0.32
26.24
32.96
15.62
6.39
0.04
23.12
2.26
5.49
13.32
-
10A-4
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§ 316(b) Existing Facilities Final Rule -TDD
Chapter 10: Appendix
Unit
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
Total increase
in Annual CO2
(tons)
3,427.09
45,620.40
127.92
9,982.55
5,883.26
214,619.09
16,853.90
24,876.82
41,790.45
38,635.50
15,647.31
112,328.50
2,957.93
41,808.74
9,977.82
15,885.15
89,591.31
41,438.63
5,627.19
148.85
6,955.23
51,350.22
6,312.31
551.25
98,796.63
128,643.03
104,088.03
3,316.93
29,456.81
125,430.47
24,843.22
100,889.85
28,645.06
46,639.02
94,162.18
43,849.02
215,723.35
26,284.78
83,873.34
64,350.01
149,318.10
54,419.06
-
73,506.91
33,331.51
14,929.32
13,141.93
71,845.14
465,996.64
Total increase
in Annual SO2
(tons)
44.84
181.72
0.16
8.94
1.17
41.72
232.41
106.21
349.91
551.81
256.38
273.52
0.32
542.94
2.22
11.59
106.55
107.78
0.03
0.18
15.62
238.61
0.03
0.03
209.09
664.68
451.36
0.04
152.77
1,212.29
122.04
387.50
571.47
353.01
558.07
179.11
1,736.65
0.17
398.21
445.24
697.85
13.21
-
461.34
209.74
0.09
4.91
501.61
1,351.75
Total increase
in Annual NOX
(tons)
7.85
83.39
0.20
15.78
4.81
64.54
50.84
40.74
163.05
149.18
55.88
51.91
1.53
97.13
4.40
25.09
82.10
66.59
3.91
0.23
12.49
128.75
1.20
0.47
276.70
209.76
456.50
3.72
57.76
180.61
139.03
117.70
55.81
63.12
171.88
75.57
475.96
8.25
129.19
143.20
287.80
32.41
-
129.32
100.16
6.66
14.04
93.99
557.28
Total increase
in Annual Hg
(Ibs)
0.17
0.92
0.20
1.21
4.89
0.58
14.10
1.92
3.80
2.41
1.25
2.31
5.53
2.28
0.87
0.69
5.34
1.51
5.06
0.69
13.13
3.63
2.66
4.18
-
4.77
2.07
3.47
8.93
Total increase
in Annual
PM2.5
(tons)
1.08
27.71
-
-
-
-
17.41
3.88
5.96
10.84
21.15
33.78
2.30
10.45
6.75
0.32
-
0.93
11.88
0.25
0.22
13.93
24.91
0.32
4.31
65.05
3.95
36.94
25.13
4.56
6.68
5.78
42.76
-
15.54
18.85
22.37
1.33
25.35
11.34
1.33
1.54
25.92
53.92
Total increase
in Annual
PM10
(tons)
1.36
28.22
-
-
-
-
19.21
4.42
7.86
12.31
27.82
38.56
2.37
17.70
8.98
0.32
-
1.22
16.62
0.25
0.22
18.60
30.44
3.02
0.32
5.03
71.23
3.95
62.39
26.31
6.14
15.33
10.05
46.92
-
30.98
23.37
23.30
1.33
29.76
14.04
1.33
1.54
29.26
72.16
10A-5
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Chapter 10: Appendix
§ 316(b) Existing Facilities Final Rule - TDD
Unit
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
Total increase
in Annual CO2
(tons)
126,653.35
112,406.67
84,840.09
120,257.80
109,150.28
31.63
86,409.28
29,407.30
73,475.45
172,555.52
82,741.51
154,976.34
47,713.04
151,309.02
21,922.20
11,196.38
41,876.76
14,759.60
55,712.41
179,421.18
212,738.66
189,651.05
65,809.54
36,324.07
15,718.64
191,789.22
20,216.39
239,320.63
13,326.31
1.64
232,197.58
247,340.42
133,651.85
181,036.27
3,492.64
318,582.91
323,849.40
193,434.16
150,672.13
40,719.17
223,448.67
8,555.80
299,311.78
176,410.50
74,228.78
188,729.21
10,802.33
72,148.92
141,882.58
Total increase
in Annual SO2
(tons)
126,653.35
2,034.33
135.58
169.46
495.24
-
396.89
50.62
589.60
1,356.09
996.05
508.53
106.61
972.71
0.11
1.80
0.23
23.50
149.93
1,251.65
420.00
1,470.08
378.27
0.30
0.04
857.49
0.11
646.69
1.13
-
2,787.33
658.21
1,528.41
1,093.83
0.32
932.07
3,755.21
2,397.29
79.21
84.37
1,630.73
0.04
755.68
503.87
355.64
437.10
0.05
115.46
860.39
Total increase
in Annual NOX
(tons)
208.98
190.48
277.76
442.70
326.70
0.01
118.42
36.82
156.50
240.19
104.63
243.02
71.76
123.17
26.27
22.64
11.94
18.14
57.41
234.68
172.87
333.25
156.37
3.55
0.87
448.65
15.36
278.35
19.61
-
415.09
521.08
413.44
345.40
2.92
198.31
500.13
323.89
25.52
65.79
298.85
1.20
181.28
247.99
224.72
166.01
0.79
168.23
315.13
Total increase
in Annual Hg
(Ibs)
11.26
4.89
2.39
6.48
4.34
4.77
9.37
9.32
9.37
6.75
8.64
33.94
5.63
6.89
7.72
8.33
13.43
9.32
8.97
21.10
20.83
7.39
9.66
12.00
9.53
27.27
1.89
5.79
Total increase
in Annual
PM2.5
(tons)
109.14
88.06
19.21
7.14
0.04
17.30
7.25
16.59
104.11
33.03
16.33
8.22
8.33
2.51
1.83
1.40
1.08
8.36
59.34
37.44
56.97
-
3.91
16.62
1.97
13.14
0.86
0.39
82.10
22.80
74.03
3.95
0.14
28.43
168.05
100.77
7.04
6.00
54.21
10.77
22.33
16.48
17.77
3.91
19.96
65.19
Total increase
in Annual
PM10
(tons)
109.21
91.90
8.69
28.00
7.65
0.04
17.91
7.25
21.11
150.21
38.34
21.76
10.45
8.33
2.51
1.83
1.40
1.26
11.74
66.27
46.02
58.66
-
3.91
31.56
1.97
22.08
0.86
1.22
91.51
29.51
74.82
7.83
0.18
34.54
219.49
108.27
7.43
6.79
63.36
10.95
27.97
22.55
28.86
3.95
38.41
87.74
10A-6
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§ 316(b) Existing Facilities Final Rule -TDD
Chapter 10: Appendix
Unit
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
TOTAL
Total increase
in Annual CO2
(tons)
17,576.18
430,167.67
303,341.43
11,130.96
492,439.33
298,837.98
133,838.18
318,262.91
552,928.93
137,532.97
280,145.79
361,319.89
279,371.93
620,697.97
319,700.75
510,476.19
49,502.38
102,624.92
934,864.48
395,263.14
2,957.39
17,817.23
236,556.23
627,946.34
650,275.69
743,242.36
606,115.85
154,739.88
19,053,703.14
Total increase
in Annual SO2
(tons)
0.09
1,048.36
3,017.74
0.06
1,926.14
2,685.20
1,154.35
1,397.99
3,825.75
748.11
1,444.56
408.45
1,167.42
1,992.54
2,680.25
3,475.57
0.25
1.38
2,975.95
1,234.25
0.01
0.09
463.21
2,861.15
3,959.99
1,985.06
627.29
1,181.66
217,882.36
Total increase
in Annual NOX
(tons)
4.39
245.26
464.77
13.98
691.02
437.93
265.87
586.15
903.42
317.88
393.03
857.18
382.51
342.07
812.09
733.05
13.41
251.19
651.78
651.74
3.52
29.71
166.69
507.50
1,270.78
178.47
975.98
356.45
27,916.17
Total increase
in Annual Hg
(Ibs)
27.63
36.96
18.58
23.38
4.79
14.88
22.55
7.66
5.65
9.55
32.76
18.87
19.32
56.86
16.94
10.06
77.30
45.12
20.97
9.47
918.43
Total increase
in Annual
PM2.5
(tons)
1.69
44.05
98.33
4.38
90.54
75.71
77.87
103.57
232.81
57.19
62.47
53.17
35.43
25.49
177.96
5.89
14.25
90.00
88.53
-
1.08
11.99
105.22
101.06
94.78
3,782.68
Total increase
in Annual
PM10
(tons)
1.72
80.74
117.18
4.38
107.48
80.85
80.20
115.13
258.30
58.05
91.04
60.81
62.29
36.94
205.31
5.89
14.25
102.28
113.80
-
1.08
12.28
171.57
108.63
129.49
4,646.25
10A.2 GIS Analyses of Expected Pollutants from Potentially Affected
Facilities
EPA created maps with the locations of all Phase II facilities (excluding manufacturers) overlaid
with maps of non-attainment areas for the various criteria air pollutants:
• Carbon monoxide (CO)
• Lead (Pb)
• Parti culate matter (PM2.5)
• Parti culate matter (PM10)
• Ozone
• Sulphur dioxide (802)
These maps present non-attainment areas designated by EPA in 2010.
10A-7
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Chapter 10: Appendix
§ 316(b) Existing Facilities Final Rule - TDD
CO Nonattainment Areas
A
Legend
• Plant_Locations
CO Nonattainment counties
Source US EPA Office of Air and Radiation, AQS Database
10A-8
-------
§ 316(b) Existing Facilities Final Rule -TDD
Chapter 10: Appendix
Pb Nonattainment Areas
A
Legend
• Plant_Locations
I Lead Nonattainmont counties Source: U.S. EPA Office of Air and Radiation, AQS Database.
10A-9
-------
Chapter 10: Appendix
§ 316(b) Existing Facilities Final Rule - TDD
PM2.5 Nonattainment Areas
A
Legend
Plant_Locations
PM2.5 Nonattainment counties Source: US EPA Office of Air and Radiation, AQS Database.
10A-10
-------
§ 316(b) Existing Facilities Final Rule -TDD
Chapter 10: Appendix
PM10 Nonattainment Areas
A
Legend
Plant_Locations
PM10 Nonattainment counties Source: U.S. EPA Office of Air and Radiation, AQS Database.
10A-11
-------
Chapter 10: Appendix
§ 316(b) Existing Facilities Final Rule - TDD
Ozone Nonattainment Areas
A
Legend
• Plant_Locations
I OzoneShr Nonattainment counties Source: U.S. EPA Office of Air and Radiation, AQS Database.
10A-12
-------
§ 316(b) Existing Facilities Final Rule -TDD
Chapter 10: Appendix
SO2 Nonattainment Areas
A
Legend
• Plant_Locations
"1 SulfurDioxide Nonattainmen! counties Source: U.S EPA Office of Air and Radiation, AQS Database
10A-13
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Chapter 10: Appendix § 316(b) Existing Facilities Final Rule - TDD
This page is intentionally left blank.
10A-14
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§ 316(b) Existing Facilities Final Rule-TDD Chapter 11: Impingement Mortality Standard
Chapter 11: 12 Month Percent Impingement Mortality
Standard: Data and Calculation
11.0 Introduction
This section describes the data selection and calculations used by EPA in establishing the
12 month percent impingement mortality standard for fish and shellfish. As explained in
the preamble to the rule, the impingement mortality standard applies only to certain
facilities. For other facilities (e.g., facilities using compliant technologies), the value of
the standard may be useful as a performance target to optimize impingement controls.
Chapter 6 describes impingement control technologies in further detail.
Sections 11.1 and 11.2 provide an overview of the available impingement data and the
data acceptance criteria. Section 11.3 identifies the facilities with data that met the
criteria. Section 11.4 describes the data and the statistical methodology used as the basis
for the impingement mortality standard. Section 11.5 provides the biological and
engineering evaluation of the standard and facility characteristics used as the basis of the
standard. Sections 11.6 and 11.7 describe alternative provision calculations and
compliance monitoring.
11.1 Overview of A vailable Impingement Data
In its evaluations of impingement, EPA considered data from research studies,
technology evaluations, and facility 316(b) demonstrations that spanned the past 40
years. While many of the documents had been collected during the Phase II rulemaking,
EPA reviewed documents that were published up to 2011. The primary objective of the
document review was to identify relevant information about the performance of different
technologies in minimizing impingement of aquatic organisms.
This chapter uses the term "study" to refer to the collection of performance data at a
single facility (or location) under a given set of testing conditions. For example, different
studies may correspond to different screen mesh sizes or approach velocities that were
tested at the same facility. A document can report performance data for one or more
studies at one or more facilities. EPA focused on studies that provided specific
performance metrics such as percent impingement mortality. It also obtained information
about the facilities themselves, including operating conditions, species of organisms
present in the intake, and time periods when the studies were conducted. Appendix A lists
the 207 documents that EPA reviewed, notes those data that were selected for the
calculations described in this section, and describes the reasons for excluding certain
documents or studies from consideration.
11-1
-------
Chapter 11: Impingement Mortality Standard
§ 316(b) Existing Facilities Final Rule-TDD
11.2 Data Acceptance Criteria
In determining whether data were acceptable for the impingement analyses described in
this chapter, EPA used the following criteria:
1. The data must provide information about one of the technologies shown in
Exhibit 11-1.
The list is more comprehensive than those identified for the proposed rule. Because the
list of technologies is more inclusive, more data were selected as the basis of the final
standard than had been used as the basis of the proposed standards.
Exhibit 11-1. Technologies With Data Considered as Basis of the 12 Month Percent
Impingement Mortality Standard
Technology
Modified Traveling
Screens3
Rotary (WIP) screens.
Variation
Through-flow screen configuration
Through-flow screen configuration combined with submerged
offshore intake.
Dual flow (double-entry single-exit) screen configuration. See
TDD Chapter 6.2.1 for a detailed description.
Geiger multi-disc traveling screen. See TDD Chapter 6.2.3 for a
detailed description
Fine-mesh screen where impingeable fish were sub-sampled"
Hydrolox screen. See TDD Chapter 6.2.4 for a detailed
description
Angled through-flow screen component offish bypass system.
See TDD Chapter 6.2.5 for a detailed description
Used in IM
Standard
Yes
Yes
Yes
Yes
Yesb
No
No
Yes
B Includes fish protection features, which at a minimum include fish baskets, low pressure wash to remove fish prior to any
high pressure spray to remove debris and a fish handling and return system with sufficient water flow to return the fish to
the source water.
b A separate sub-sample of the impingeable fish were separated from smaller fish impinged on fine-mesh screens by
passing collected fish through a 3/8 in mesh screen.
2. The reported data values must be actual measurements (e.g., fish counts) rather than
estimates or model-based predictions.
3. The data must relate to impingement mortality offish and/or shellfish. This criterion
requires documents to report impingement mortality as numbers offish or a
percentage of impinged fish that were killed. EPA extracted impingement data in one
of four different ways, depending on the type of impingement data reported in the
documents. These four approaches are as follows, in decreasing order of application:
a. Total number of impinged fish, along with numbers of impinged fish that
were killed.
b. Impingement survival counts and numbers of impinged fish.
c. Percentage of impinged fish that were killed.
d. Percentage of impinged fish that survived.
11-2
-------
§ 316(b) Existing Facilities Final Rule-TDD Chapter 11: Impingement Mortality Standard
4. The data must reflect technology performance that is representative of conditions
that may exist under actual facility operations. As a consequence of this criterion,
EPA:
a. Included data from studies conducted on existing structures at facilities;
b. Included data from field tests conducted near intake locations (e.g., from a test
barge). Before full-scale installation, facilities often test the suitability of
technologies in conditions that they consider to mimic (or represent) typical
facility conditions.
c. Included data from facilities that ceased operations after the study was
conducted, as long as the data met the other criteria.
d. Excluded data from tests performed under controlled laboratory conditions. In
contrast to the facility and field studies that generally are designed to represent
normal conditions and operations, laboratory studies generally studied how
impingement was affected by varying different components of the technology.
In such studies, the laboratories sometimes operate the technologies with the
intention of increasing impingement occurrences. As a consequence, data
from these studies may not be representative of the types offish typically
impinged and the technology performance.
5. The impingement data must be for fish and shellfish species that are not classified as
fragile. This criterion is less restrictive than the proposal's requirement for the data
to include only fish species that were typical, and prevalent, at the facility location.
EPA modified three parts of the criterion as follows:
a. EPA excluded data for fragile species, because the observed mortality data
from fragile species might, in large part, reflect conditions other than
technology performance. Of the data that otherwise met the criteria in this
section, Exhibit 11-2 lists the species that EPA classified as fragile and
excluded as the basis of the standard.188 Appendix B lists the non-fragile
species that ultimately served as the basis of the standard.
Exhibit 11-2. Species Classified as Fragile in Data Otherwise Meeting Data Selection
Criteria"
alewife
alosa spp.
american shad
atlantic herring
atlantic long-finned squid
atlantic menhaden
bay anchovy
blueback herring
bluefish
butterfish
gizzard shad
gray snapper
hickory shad
menhaden
rainbow smelt
round herring
silver anchovy
"Refer to DON 12-6700 and 12-6808 for details on the derivation of this table.
188 EPA compared its own BPJ designation of fragile species to species in families designated by EPRI as
having low impingement survival and found the two lists to be in general agreement. EPRI based the
designations upon apparent survival from prior studies. Where the lists conflicted, EPA chose the EPRI
designation.
11-3
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Chapter 11: Impingement Mortality Standard § 316(b) Existing Facilities Final Rule-TDD
b. EPA eliminated a proposed requirement that the species were typically
observed and predominant at the facility location. EPA made this change
because technology performance does not depend on whether a species is
typically observed or predominant in a particular location.
c. EPA expanded the list of proposed species subject to the rule to include
shellfish because the compliant technologies have demonstrated that they also
control shellfish impingement.
6. The study must have measured total mortality from 18 to 96 hours following
impingement. This criterion extends the proposal's restriction that data must be no
later than 48 hours to 96 hours following impingement, because EPA received
information that demonstrated that mortality rates were comparable to the proposed
48 hour holding time. See DCN 12-6703 for more details. As a consequence of this
criterion, EPA excluded:
a. Studies that reported only instantaneous mortality ("zero holding times") or
holding times less than 18 hours. As it noted in the proposal, EPA considers
that such counts may be understated because they only measure immediate
deaths and not those organisms that were mortally harmed as a result of
impingement. They also might reflect already injured, nearly dead, or already
dead fish ("naturally moribund") that were impinged by the screen.
b. Data associated with mortality that occurred in excess of 96 hours following
impingement. Such counts may be overstated because these longer holding
times may cause mortality for reasons not directly reflective of technology
performance, such as conditions that do not adequately reflect the organisms'
natural habitats.
7. Because compliance with the standard will be evaluated on a 12 month basis, EPA
eliminated any data that did not represent a full year. In some instances, EPA was
able to include data that covered representative impingement periods of
approximately one year even if the data was not continuously collected over the 12
month period. For example, the study may have identified that during portions of the
year insufficient organisms could be collected to conduct statistically valid
monitoring. Such studies were not rejected because they still represent a full year of
performance. This criterion does eliminate those data that covered only a few
months, such as data representing a single season, and which therefore cannot be
used to determine 12 month performance. This criterion also eliminates certain data
that covered substantially more than a 12 month period if the dates of data collection
were not sufficiently documented to determine which data coincides with a 12
month period. In such cases, EPA attempted to include data representing one year's
worth of performance, but did not include the data for additional periods beyond one
year. Further, this criterion eliminated data for which the collection period was
unknown or the study documentation presented contradictory information about the
collection period.
Criterion 1 indicates the screen technologies considered in the impingement mortality
standard data set. Exhibit 11-2 presents a list of technologies that are likely compliant
with today's impingement mortality requirements but were not included in the
11-4
-------
§ 316(b) Existing Facilities Final Rule-TDD
Chapter 11: Impingement Mortality Standard
development of the impingement mortality standard. Performance data for these
technologies were not used because they did not meet the above specified criteria for
development of impingement mortality standard. Primary reasons for rejecting associated
data are identified in the table.
Exhibit 11-2. Compliant Technologies Not Considered as Candidate for Basis of 12
Month Percent Impingement Mortality Standard
Technology
Fine Mesh Modified Traveling
Screens
Existing Velocity Cap at Offshore
Intake
Cylindrical Wedgewire Screens
Screen velocity <0.5 fps
Closed-Cycle Cooling
Reason
Could not estimate mortality for just those
impinged fish that are retained on a 3/8 inch
square mesh
Fish diversion difficult to measure and generally
not quantified; no distinction made between
reduced impingement by virtue of offshore
location and reduced IM of the velocity cap
Fish diversion difficult to measure and
impingement mortality difficult to sample;
performance data from barges or labs did not
meet criteria for acceptance
Fish diversion difficult to measure; distinction
between impinged fish retained on a 3/8 inch
square mesh and entrainable fish not made
Species and counts data not collected by most
facilities; reported reductions in flow could not be
extrapolated to counts by species and age group
Used in IM
Standard
No
No
No
No
No
11.3 Facility Data Used As Basis of 12 month Percent
Impingement Mortality Standard
Of the studies listed in Appendix A, impingement mortality data from 17 facilities met
the criteria and thus were used as the basis of the impingement mortality standard.
Exhibit 11-3 lists the facilities and the study identification number used in Appendix A.
As shown in Exhibit 11-4, the facilities are geographically located throughout the Eastern
seaboard and the Midwest. All waterbody types (oceans, lakes, rivers, and estuarine
waters) are represented by the data. EPA notes that data for Arthur Kill (which had been
included at proposal) and some (but not all) data for Salem are excluded because while
the data was collected for one or more seasons, the data was not fully representative of
time periods of approximately one year. The impingement mortality data used as the
basis of the 12 month percent impingement mortality standard can be found in DCN 12-
5400.
11-5
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Chapter 11: Impingement Mortality Standard
§ 316(b) Existing Facilities Final Rule-TDD
Exhibit 11-3. Facilities and Data Selected as the Basis of the Impingement Mortality
Standard
Facility
Barrett
Brunswick
Danskammer
Point
Dunkirk
Huntley
Indian Point
JP Madgett
Manchester
Street
Millstone
Mystic Station
North Omaha
Northside
Oyster Creek
Potomac
Prairie Island
Roseton
Salem
Somerset
(Kintigh)
Location
Island Park, NY
Southport, NC
Newburgh, NY
Dunkirk, NY
Tonawanda, NY
Buchanan, NY
Alma, Wl
Providence, Rl
Waterford, CT
Everett, MA
North Omaha, NE
Jacksonville, FL
Lacey Township,
NJ
Alexandria, VA
Red Wing, MN
Newburgh, NY
Lower Alloways
Creek Township,
NJ
Somerset, NY
Time Period
Oct. 2007- Jun. 2008
Apr. 1984 -Apr. 1985
Winter/Spring 1980
Dec. 1998 - Nov.
1999
Jan. 1999 -Oct. 1999
June 1977 - Dec.
1977
Jan. 1985- Dec.
1985
May 1980 - Dec.
1980
Jan. 1996 -Feb. 1997
May 1986 -Apr. 1987
Jan. 1993- Dec.
1993
Oct. 1980- June
1981
Apr. 2008 -Aug. 2008
Mar. 1998 -Jan. 1999
Feb. 1985 -Dec.
1985
Nov. 2005 - Dec.
2006
Apr. 1988 -Aug. 1988
May 1990 - Nov.
1990
May 1994 - Nov,
1994
Oct. 1997 -Sep. 1998
1985
1986
May 1989 - Dec.
1989
Number of
Sampling
Events3
27
34
16-32
(2 seasons)
32
10
(2 seasons)
17
(3 seasons)
-115
35
NS
32
25
31
(3 seasons)
2 months
(2 seasons)
Quarterly
48
73
63
(2 seasons)
815
(3 seasons)
67
(3 seasons)
-78
(3 seasons)
NS
NS
17
(3 seasons)
Holding
Times
48 hr.
96 hr.
84 hr.
24 hr.
24 hr.
84 hr.
96 hr.
96 hr.
48 hr.
24 hr.
24 hr.
24 hr.,
96 hr.
48 hr.
48 hr.
96 hr.
48 hr.
48 hr.
96 hr.
48 hr.
18hr.
96 hr.
96 hr.
96 hr.
Documen
t ID(s)b
221
193,201,
208
239
44
51
205-A
193,201,
240, 241
242
228
245
246
143
238
249
248
193,201,
196
193,201
193,201
247
193,201
64
64
243
Study
ID(s)c
254
165, 166
270
8
1
282
163, 271
274
284
268
269
88, 89,
90, 283
281
276
277
91
160
70
278
161
5
5
273
a NS = not specified. The sampling events are assumed to represent all four seasons unless specified in parentheses.
b See Appendix A for document titles and authors.
0 See DON 12-5400.
11-6
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§ 316(b) Existing Facilities Final Rule-TDD
Chapter 11: Impingement Mortality Standard
Exhibit 11-4. Geographic Distribution of Facilities Used as the Basis of the
Impingement Mortality Standard
Mystic Station
Manchester Street
0 150 300 GOO
^^^^•J^^^^^^^^^^^^^^B Kilometers
11-7
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Chapter 11: Impingement Mortality Standard § 316(b) Existing Facilities Final Rule-TDD
11.4 Statistical Basis of 12 Month Percent Impingement
Mortality Standard
EPA applied statistical methods to develop the 12 month percent impingement mortality
standard. Statistical methods are appropriate for dealing with impingement data because
the mortality rates, even in well-operated systems, are subject to a certain amount of
random fluctuation or uncertainty. Statistics is the science of dealing with uncertainty in a
logical and consistent manner. Statistical methods, therefore, provide a logical and
consistent framework for analyzing a set of impingement data and determining values
from the data that form a reasonable basis for the impingement mortality standard. The
following discussion describes the steps that EPA used to calculate the 12 month
averages, apply the statistical methodology, and statistically evaluate the resulting
standard value.
First, EPA used the data that met the criteria in Section 11.2 to calculate 12 month
averages. Using each facility's data, EPA summed across sampling events as necessary to
obtain the total number offish that were impinged and the total number that were killed
for each approximately 12-month period. The fourth and fifth columns in Exhibit 11-5
provide the total number killed and the number impinged that resulted from EPA's
evaluation of the facility data. If the studies reported the number offish that survived,
then the number in the fourth column (number killed) was calculated by subtracting the
number that survived from the total number impinged (fifth column) as shown in the
equation below:
total number killed = total number impinged — total number survived
Second, EPA calculated the 12 month average percent impingement mortality (EVI) as the
ratio of the total number offish killed to the total number offish impinged. This
calculation is shown in the following equation and the results presented in the sixth
column of Exhibit 11-5:
, „ , total number killed , „„
annual average percent 1M = x 100
total number impinged
For one facility (Prairie Island) that reported its data as %IM for each species instead of
the numbers offish, the sixth column (average %IM) of Exhibit 11-5 is the average of the
%IM for the non-fragile species.
The sixth column of Exhibit 11-5 shows that there are 26 12 month averages across 17
different facilities. Brunswick, Indian Point, Millstone, Roseton, and Somerset have
multiple 12 month values as their impingement data span multiple 12 month periods.
Third, to avoid giving any one facility more influence than others in developing the
standard,189 EPA calculated the facility average %IM by averaging the facility 12 month
189 EPA believes that it is inappropriate to assign undue weight to facilities simply because they provided
more data (i.e., data for multiple 12-month periods). Such an approach would allow facilities with the most
data points to have an excessive influence on overall regulatory values.
11-8
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§ 316(b) Existing Facilities Final Rule-TDD
Chapter 11: Impingement Mortality Standard
averages. When only one 12 month value was associated with a given facility, the 12
month %EVI is the same as the facility 12 month %IM. Exhibit 11-5 provides the facility
averages in the last (seventh) column.
Exhibit 11-5. Impingement Mortality Data Used As a Basis for the Impingement
Mortality Standard
Facility
Barrett
Brunswick
Danskammer
Point
Dunkirk
Huntley
Indian Point
JP Madgett
Manchester Street
Millstone
Mystic Station
North Omaha
Northside
Oyster Creek
Potomac
Prairie Island
Roseton
Salem
Somerset (Kintigh)
Location
Island Park, NY
Newburgh, NY
Dunkirk, NY
Tonawanda, NY
Buchanan, NY
Alma, Wl
Providence, Rl
Waterford, CT
Everett, MA
North Omaha, NE
Jacksonville, FL
Lacey Township,
NJ
Alexandria, VA
Red Wing, MN
Newburgh, NY
Lower Alloways
Creek Township,
NJ
Somerset, NY
Time Period
Oct. 2007- Jun. 2008
1984 (to Jan. 1985)
Winter/Spring 1980
Dec. 1998 -Nov. 1999
Jan. 1999 -Oct. 1999
June 1977 -Dec. 1977
Jan. 1985 - Dec. 1985
May 1980 -Dec. 1980
Jan. 1996 -Feb. 1997
May 1986 -Apr. 1987
Jan. 1993 - Dec. 1993
Oct. 1980 -June 1981
Apr. 2008 -Aug. 2008
Mar. 1998 -Jan. 1999
Feb. 1985 -Dec. 1985
Nov. 2005 - Dec. 2006
Apr. 1988 -Aug. 1988
May 1990 -Nov. 1990
1994
Oct. 1997 -Sep. 1998
1985
1986
1989
Total
Impinged
Mortality
654
179,396
116
352
56
29
3,373
153
161
205
146
60
91
63
532
1,054
-
4,639
1,133
2,840
56
9
14
Total
Impinged
Fish
2,732
898,914
378
14,699
3,540
41
12,514
615
654
983
580
349
1,133
185
6,065
2,925
-
8,645
7,289
7,543
1,291
169
48
12
Month
Average
% IMa
23.9
20.0
30.7
2.4
1.6
70.7
27.0
24.9
24.6
20.9
25.2
17.2
8.0
34.1
8.8
36.0
47.7
53.7
15.5
37.7
4.3
5.3
29.2
Facility
Average
%IM
23.9
20.0
30.7
2.4
1.6
48.8
24.9
24.6
23.0
17.2
8.0
34.1
8.8
36.0
47.7
34.6
37.7
12.9
a EPA recognizes that these data indicate that several of the intakes as configured and operated at the time of sampling
would not meet the standard. However, EPA believes that these facilities would be able to modify and optimize the
traveling screens in a manner that would allow them to be deemed compliant with the impingement mortality BTA
standard as discussed in Section 11.5. EPA has included additional costs for this in the compliance cost estimates. See
TDD Section 8.3.4 for a detailed discussion.
Fourth, EPA modeled the distribution of the 17 facility average %IM values. As it had for
the proposed standards, EPA selected the beta family of statistical distributions as the
basis to model the values, because the distributions are continuous and bounded by 0 and
1. This is equivalent to the range of impingement mortality percentages between 0 and
100. By applying the beta distribution to the data in the last column of Exhibit 11-5, EPA
calculated the statistical expected value of the distribution. Under the beta distribution,
the expected value is the equal to the arithmetic average. As a result of applying the
11-9
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Chapter 11: Impingement Mortality Standard § 316(b) Existing Facilities Final Rule-TDD
statistical methodology, EPA established the 12 month impingement mortality standard
as 25 percent impingement mortality after rounding up from 24.3 percent.
Fifth, as an important step in evaluating the statistical methodology, EPA compared the
standard to the data used to derive it. EPA performs this comparison to ensure that the
statistical model is appropriate and that it used appropriate distributional assumptions for
the data used to develop the standard (i.e., whether the curves EPA used provide a
reasonable "fit" to the actual data). If the distribution were appropriate for the data, EPA
would expect roughly half of the 12 month average values to be above 25 percent and
half to be below; and the mean and median to be approximately equal. This is roughly
what is observed. Seven of the facility values in Exhibit 11-5 are greater than the standard
of 25%IM; and two values of 24.6 percent and 24.9 percent are relatively close to the
standard. The observed median value is 24.6 percent. As a result of this comparison, EPA
determined that the distributional assumptions appear to be appropriate for these data.
11.5 Biological and Engineering Reviews of 12 Month Percent
Impingement Mortality Performance Standard
In conjunction with the statistical methods, EPA performed engineering and biological
reviews which are yet another important step in verifying that the standard is reasonable
based upon the design and expected operation of the technologies and the site conditions.
As part of those reviews, EPA examines the technology and site description to ensure that
the technology tested included important basic components of a modified traveling screen
or its equivalent. EPA only included data from technologies where the mesh size was
roughly equivalent to 3/8 inch coarse mesh which included 1/8 inch x l/2 inch and 1A by l/2
inch mesh since the diagonal dimensions are within -3 percent to 5 percent of 3/8 inch
mesh. EPA also included data from screens with a smaller (finer) mesh if the
impingement data indicated that the data could be separated by life stage, and therefore
EPA could approximate the categories offish that would be impinged on a 3/8 inch
screen versus impinged on the finer mesh screen. EPA also included data where a facility
screened all impinged organisms with a 3/8 inch mesh to count only those organisms that
would be impinged on a 3/8 inch mesh screen (i.e., the "hypothetical net"). Operating
information was also examined to ensure that operating conditions (e.g., intermittent
screen operation), did not degrade performance compared to a more optimum condition.
Data for technologies that did not meet minimum design criteria were excluded from the
standard calculation.
As part of the biological review, EPA reviewed the list offish species contained in the
data sets and evaluated them independently on the basis of fragility since the observed
mortality data from fragile species might, in large part, reflect conditions other than
technology performance. See DCN 12-6700 for a detailed discussion of the criteria used.
EPA also examined whether the data reflected only fish that entered the intake directly
from the source water and not those that were introduced190. EPA also evaluated the data
190 In some studies impingement rates were low and fish either captured from the waterway or obtained
from another source (e.g., a fish hatchery) were introduced into the intake forebay in order to ensure the
impingement sample size was large enough to evaluate screen performance.
11-10
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§ 316(b) Existing Facilities Final Rule-TDD
Chapter 11: Impingement Mortality Standard
to ensure that fish that were clearly dead or moribund prior to impinging on the screen
were not counted in the impingement mortality totals.
Exhibit 11-6 illustrates the characteristics of the facility intakes and technologies selected
for impingement mortality standard development.
Exhibit 11-6. Characteristics of Facilities Used As Basis for Impingement Mortality Standard
Facility
Name
Brunswick
Danskammer
Point
Dunkirk
Huntley
Indian Point
JP Madgett
Kintigh
(Somerset)
Manchester
Street
$
OJ
4-1
w
NC
NY
NY
NY
NY
NY
Wl
NY
Rl
Waterbody
Type
Estuary
Bay
Great
Lakes
Fresh-
water
River
River
River
River
Great
Lakes
River
Predominant
Species
atlantic croaker,
spot, bay anchovy,
shrimp, blue crab
white perch,
atlantic tomcod,
alewife, blueback
herring, american
shad, gizzard shad,
spottail shiner
alewife, shiners,
rainbow smelt,
white bass, white
perch, yellow perch
alewife, gizzard
shad, rainbow
smelt, emerald
shiner
catfish, smelts,
gizzard shad
white perch,
weakfish, atlantic
tomcod, blueback
herring
gizzard shad,
bluegill, logperch,
flathead catfish,
freshwater drum
alewife, gizzard
shad, rainbow
smelt, spottail
shiner
atlantic menhaden,
winter flounder,
atlantic silversides,
white perch,
threespine
stickleback,
northern pipefish
Study
Period
1984; 1985;
1986; 1987;
2008
Winter/
Spring 1980
Each
season from
December
1998 to
November
1999.
January and
October
1999
June 1977-
Dec. 1977
Jan. 1985 -
Dec. 1985
May 1980-
Dec. 1980
1985; 1986;
1989
Jan. 1996 -
Feb. 1997
Generating
Units/CWISs
2 generating
units
4 generating
units
Screenhouse
#1, including
Units 1 and 2
Units 67 and
68
Unitl
Unit 2, 6
intake bays
(#21-26)
5 pumps
Design
Intake Flow
596 mgd
(Dec-Mar);
710 mgd
(Apr-Nov)
92.2 mgd
82.8 mgd
201 mgd
201 mgd
281 mgd
Technology
3/8 in mesh diversion
structure with traveling
screens one half 3/8 in and
one half 1 mm with fish
return (2 of 4 intakes use
fine mesh screens)
3/8 in conventional front
wash traveling screens that
have been retrofitted with
fish collection trough (with
water) and low pressure
spray
1/8 x 1/2 inch prototype
modified traveling screen
1/8 x 1/2 inch prototype
modified traveling screen
2.5 mm fine mesh modified
Ristroph traveling screen
Modified traveling screens,
3/8" mesh, low pressure
wash, fish protection and
collection features
Modified traveling screens
with fish trays and
sluiceways. Low pressure
wash
Fine mesh (1 mm) traveling
screens with fish trays and
return, low pressure spray,
sluice trough. Includes 2000
feet off shore velocity cap
intake.
3/8 in Ristroph-type
traveling screens
continuous operation and
separate fish return.
11-11
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Chapter 11: Impingement Mortality Standard
§ 316(b) Existing Facilities Final Rule-TDD
Facility
Name
Millstone
Mystic
North Omaha
Northside
Oyster Creek
Potomac
Prairie Island
Roseton
Salem
$
2
V)
CT
CT
MA
NE
FL
NJ
VA
MN
NY
NY
NJ
Waterbody
Type
Bay/ Long
Island
Sound
Bay/ Long
Island
Sound
River
River
River
Bay
River
River
River
River
River/
estuary
Predominant
Species
pipefish, butterfish,
bay anchovy,
atlantic menhaden,
rock crab
winter flounder
smelt, alewives,
blueback herring,
winter flounder
hatchery fish trial
(bluegill, catfish,
fathead minnow);
native fish trial
(shiners)
drum family
(spotted and gray
seatrout, spot,
silver perch, red
drum.star drum,
and Atlantic
croaker)
bay anchovy,
atlantic menhaden,
spot, atlantic
silverside,
smallmouth
flounder, striped
searobin
white perch,
bluegill, spottail
shiner
freshwater drum,
channel catfish,
gizzard shad
blueback herring,
bay anchovy,
american shad,
alewife
blueback herring,
alewife, bay
anchovy, brown
bullhead, striped
bass, white perch,
american shad
weakfish, white
perch, bay
anchovy, atlantic
croaker, blue crab
Study
Period
May 1986-
Apr. 1987
Jan. 1993-
Dec. 1993
Oct. 1980-
June 1981
Apr. 2008 -
Aug. 2008
Mar. 1998-
Jan. 1999
Feb. 1985-
Dec. 1985
Nov. 2005 -
Dec. 2006
Apr. 1988-
Aug. 1988
May 1990-
Nov. 1990
May 1994-
December
1994
Oct. 1997-
Sep. 1998
Generating
Units/CWISs
Unit 3 fish
return
Units 1, 2, and
3
Unit 7
Intake No. 3
Units
5 generating
units, 10
pumps
2 generating
units
2 generating
units
2 dual-flow
screens
Units 1 and 2
Design
Intake Flow
1355 mgd
2817mgd
(all 3)
730.4 mgd
827 mgd
659 mgd
438 mgd
970 mgd
922 mgd
1598 mgd
Technology
3/8 in traveling screen with
fish return spray pressure of
85 psi. Screen rotates
based on pressure
differential, or once every 8
hours.
3/8 in traveling screen with
fish return
Coarse mesh traveling
screen; fish buckets, low-
pressure spray, fish return
Rotary screen (WIP screen)
Traveling screens with low
pressure spray, fish pans
spaced 4 ft
Conventional screens
replaced with Ristroph
traveling screens with low
pressure spray, fish buckets
GeigerTS, 9.5-mm plastic
screening, fish buckets, 5
psi fish spray, fish return
0.5mm fine mesh vertical
traveling screens
9.5-mm dual-flow TS; low
pressure spray, collection
buckets, and return trough
9.5-mm dual-flow TS
(modified); low pressure
spray, collection buckets,
and return trough
Modified Ristroph with
improved baskets, 1/4x1/2
in smooth mesh, continuous
operation, low pressure
spray, separate smooth
fiberglass return trough.
11-12
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§ 316(b) Existing Facilities Final Rule-TDD Chapter 11: Impingement Mortality Standard
The facility distribution in the map in Exhibit 11-4 and data in Exhibit 11-6 above show
that the data included in the standard development are representative of the wide range of
waterbodies and fish species that might be expected to occur nationwide. Upon initial
review of the data in Exhibit 11-5, the impingement mortality data represent performance
ranging from 1.6 percent to 48.6 percent. The performance metric is comprised of
biological elements (i.e., the behavior offish) as opposed to the more certain performance
and measurements of a physical or chemical system (e.g., concentration of copper). As is
the case with any varied system performance, those facilities operating in the lower end
of the spectrum of performance may require some changes to operation or upgrades in
their existing technology in order to meet the standard that is based on the 12 month
performance. The available data suggests that in the case of traveling screens this can be
managed by optimized operation of the technology. Under the final rule, a facility is
required to conduct 2 years of monthly impingement monitoring, during which the
facility will seek to optimize the technology performance to minimize impingement
mortality. This study is intended to determine the optimal configuration and operating
conditions of modified traveling screens for that intake to be consistently protective of
aquatic organisms. During the course of the study, EPA expects that a facility will
evaluate the interim results and make changes to the technology or operating conditions
as needed to identify the most appropriate set of operational characteristics to ensure
long-term success. For example, a facility could adjust the spray wash pressure, adjust the
rotating speed of the screens, rotate the screens more frequently, re-angle the fish sluicing
sprays, ensure adequate water in the return flume, design the fish return to avoid avian
and animal predation on the aquatic organisms, and locate the fish return in such a way to
avoid predation. EPA notes that the EVI data representing the lower end of performance
can be identified as missing one or more of these operational characteristics during the
periods of lowest performance. Further, many studies seek to assess current operations,
and are not intended to optimize operation. EPA expects that when a facility actively
seeks to optimize operation of the technology, it would achieve better long term
performance. EPA's record includes numerous performance studies that compare specific
operational conditions as examples of the improvements EPA anticipates upon
completion of an optimization study. Other studies in EPA's record, while not meeting
the criteria for use in calculating the standard, demonstrate the technology performs in a
manner consistent with EPA's calculated 12 month percent impingement mortality
standard. The final rule requires the 2 year optimization study, and further requires that
the Director impose permit conditions that reflect optimized operation. EPA expects
implementation of these provisions will result in the best possible performance for each
facility.
In addition to contingency cost factors and the incremental O&M costs described in
Chapter 8, EPA further notes that the compliance costs consider added costs that may be
incurred by facilities that perform below the average. These additional costs may be
incurred by some facilities where the performance of technology with respect to biology
(i.e. behavior offish) may be insufficient, and thus the rule would impose additional
compliance costs due to uncertainty or factors not adequately represented by currently
available data. These costs include O&M costs such as adjustments and modifications to
the design of the traveling screens, fish handling and returns, and operating conditions. In
a worst-case scenario, EPA expects additional low-cost technologies such as barrier nets
11-13
-------
Chapter 11: Impingement Mortality Standard § 316(b) Existing Facilities Final Rule-TDD
could be employed which would allow the facility to meet the impingement mortality
BTA standard. Approximately 15 percent of facilities are assessed costs for barrier nets,
consisting of predominantly marine intakes as they are the most likely intakes for higher
rates of impingement. Facilities would not be required to use barrier nets, rather the costs
of barrier nets may be considered a cost "allowance" for installing additional
technologies. Finally, a facility could use supplemental technologies and practices, such
as variable frequency drives and behavioral deterrents, which are combined to form a
"systems" of technologies. The "systems" approach is discussed in Section 11.6 below.
See TDD Chapter 8.7.4 for a more detailed cost discussion.
In conclusion, as a result of the combined statistical modeling (Section 11.4) and
engineering/biological reviews (this section) used in developing the standard, each
facility with the technologies is expected, on average, over a period of time, generally
one year, to be capable of designing and operating their systems to meet the impingement
mortality BTA standard. This conclusion is supported in part by the fact that several
facilities with entrainment mortality data that was not used in the limitations development
demonstrated compliance.191
11.6 Alternative Provision Calculations
One alternative for compliance allows a facility to use a system of technologies and/or
operational measures to achieve the BTA standard for impingement mortality
requirements. This system of technologies might employ screening technologies that can
be directly monitored for impingement mortality plus other technologies and operational
measures for which indirect methods of estimating impingement reduction may be used
(e.g., fish avoidance technologies, intake location, and flow reduction). If the technology
reduces impingement, the alternative provision calculations would increase the number of
the observed impinged fish by the estimated number that would have been impinged
without the technology. The facility then would compare the observed number of killed
fish to the larger total number of impinged fish (i.e., the sum of observed and estimated
number reduced by technology). This comparison would result in a lower impingement
mortality rate than the unadjusted, observed value.
The following example from the Notice of Data Availability (77 FR 34323) illustrates
how the alternative provisions would adjust for flow, location, and other technologies
demonstrating that the facility's performance is consistent with the impingement
mortality standard. To demonstrate the application of the adjustments, the example is
repeated below.
The example uses values that simplify the calculations to better illustrate the adjustments,
and are not intended to reflect values that EPA expects at any facility. To simplify the
example further, the facility has only fish and does not have shellfish in its source waters.
191 EPA identified three facilities employing modified traveling screens where latent mortality data
presented in studies resulted in calculated mortality rates that would be compliant with the 12-month
percent impingement mortality standard. The data from these facilities was not used in the standard
development because it did not meet all of the data acceptance criteria. These facilities include Arthur Kill
(DCN 10-5442), Brayton Point (DCN 4-1682, and Hudson (DCN 11-5530).
11-14
-------
§ 316(b) Existing Facilities Final Rule-TDD Chapter 11: Impingement Mortality Standard
EPA also recognizes that facilities often examine the combined effect of two or more
technologies (e.g., deterrents and offshore location) within a single study. In applying the
alternative provision, the facility could use the outcomes associated with the combined
performance of multiple technologies. However, for a more complete example, EPA has
chosen a hypothetical facility that examined each change in a separate study.
The hypothetical facility is located at an offshore location, has a velocity cap, and
installed variable speed drives. For the purposes of this example, assume its permit
requires that it collect samples once a week, evaluate the impinged fish after 24 hours,
and report on a monthly basis. The facility has just completed sampling at the forebay
each week during June, and has identified the counts of the facility-specific species of
concern as follows. The four samples had 1,500, 1,000, 500, and 1,000 impinged fish, for
a total of 4,000 impinged fish. During the 24-hour holding period, 450, 250, 150, and 350
fish died, for a total of 1,200 dead fish. The facility then calculated the forebay's
impingement mortality (EVI) as 30 percent, using the equation provided in the proposed
rule preamble (76 FR 22174, Section IX.F.l) as follows:
total number killed
annual average percent IM = x 100
total number impinged
= (1,200/4,000) x 100
= 30%
To adjust the observed percent impingement mortality for its offshore location and
velocity cap, the facility first extracts information from its previously conducted studies
related to performance and calculation baseline. For the offshore location adjustment, fish
density and flow data show the offshore location reduces the rate of impingement for all
species of concern by 30,000 fish annually, or, on average, 2,500 each month (i.e.,
calculated as 30,000 fish divided by!2 months). For the velocity cap, performance data
show the velocity cap reduces impingement offish and shellfish by 42,000 organisms
annually, or a monthly average of 3,500 organisms. Therefore, the facility has reduced
impingement of all species of concern, on average each month, by 6,000 organisms
(i.e., sum of 2,500 for offshore location and 3,500 for velocity cap). The facility then
applies the reduction to the denominator of the percent EVI calculations as follows:
= (impinged fish that are killed)
x 100
(total number impinged + reductions in fish impinged due to other technologies)
= ((1,200 / (4,000 + 6,000)) x 100
= 12%
In summary, calculating percent impingement mortality at the forebay yields a 30 percent
EVI, and then applying the alternative provisions for other technologies shows the
effective percent EVI is 12. Next, to adjust for the variable speed drives, the facility has
determined from engineering and design calculations that the volume of cooling water
flow has been reduced by 10 percent. The volume of reduced flow multiplied by the
density offish near the intake is calculated, and the facility projects that the reduced flow
11-15
-------
Chapter 11: Impingement Mortality Standard § 316(b) Existing Facilities Final Rule-TDD
excludes, on average for each month, an additional 1,100 fish from impingement. Then
the facility would apply the reduction in impinged fish to the denominator, as follows:
= (impinged fish that are killed)
x 100
(total number impinged + reductions in fish impinged due to other technologies)
= ((1,200) / (4,000 + 6,000 + 1,100)) x 100
= 11%
This example is intended to illustrate how facilities would obtain credit for existing
technologies. While this example includes a velocity cap, it does not imply that a velocity
cap is the appropriate technology for all facilities. EPA's data shows in most cases, a
properly located velocity cap alone may be sufficient to achieve the impingement
mortality BTA standard. In the case where a velocity cap (or any other technology) alone
would not be sufficient to meet the BTA standard, EPA expects that each facility would
identify and install a suite of cost effective technologies to achieve the EVI requirements
(i.e., variable speed drives in this example).
In summary, the hypothetical facility would observe a 30 percent EVI rate for June; which
would then be adjusted downward to 12 percent for its offshore location and velocity cap;
and then further adjusted downward to 11 percent for its flow reduction. The value that the
facility would report for compliance purposes would be the 11 percent value. At the end of
the 12-month monitoring period, the facility also would use the 11 percent value for that
month with the other 11 adjusted monthly values to calculate the 12 month average EVI rate.
11-16
-------
§ 316(b) Existing Facilities Final Rule -TDD Chapter 11: Appendix A
Appendix A to Chapter 11: Impingement Mortality
Studies
The table in this appendix provides information about the studies and data evaluated for
Chapter 11.
Exhibit 11 A-l identifies the documents and whether they:
• Included impingement data (i.e., counts or percentages)
• Were used to develop the impingement mortality standard, and reasons for using
or not using the data
• Are included in the performance database (DCN 12-5400).
11A-1
-------
Exhibit 11A-1. List of Documents Reviewed for Data on Impingement For Use in Preparing Impingement Mortality Standard
o
ID
4
5
8
16
17
150
18
38
39
40
41
DCN
DON 5-4053
DCN 1-301 9-
BE
DCN 4-4002B
DCN 5-4397
DCN 5-431 3
DCN 5-441 4
DCN 5-4391
DCN 5-4389
DCN 5-441 7
DCN 5-4322
Authors
CCI Environmental
Services
US EPA Region IV
EPRI
Lawler Matusky &
Skelly Engineers
AWH Turnpenny, R
Wood, and KP
Thatcher
Ecological Analysts
Inc.
JB Hutchinson and
JA Matousek
J Homa, M Stafford-
Glase, and ME
Connors;
Ichthyological
Associates, Inc.
Lawler, Matusky, &
Skelly Engineers
LLP
Lawler, Matusky, &
Skelly Engineers
LLP
Title
Zooplankton Entrainment Survival
at the Anclote Power Plant Near
Tarpon Springs, Florida
In the Matter of Florida Power
Corporation, Crystal River Power
Plant, Units 1 , 2 and 3, Citrus
County Florida, NPDES Permit No.
FL0000159, Findings and
Determinations, per 33 USC 1326
Fish Protection at Cooling Water
Intakes: Status Report
Intake Research Facilities Manual
Fish Deterrent Field Trials at
Hinkley Point Power Station,
Somerset, 1993-1994
Potrero Power Plant CWIS 316(b)
Demonstration
Evaluation of a Barrier Net Used to
Mitigate Fish Impingement at a
Hudson River Power Plant Intake
An Evaluation of the Effectiveness
of the Strobe Light Deterrent
System at Milliken Station on
Cayuga Lake, Tompkins County,
New York
Lovett Generating Station
Gunderboom System Evaluation
Program
Lovett Generating Station
Gunderboom Deployment
Program, 2000
Date"
1994
1988
1999
1985
1994
1980
1988
1994
1998
2001
Impingement Data
Data
Pre-
sent?
No
Yes
Yes
No
Yes*
Yes*
Yes*
No
No
No
Used?
No
No
No
No
No
Reasons for Use/Non-Use
No impingement data
Brief mention of total annual impingement of two shrimp and crab
species is given in tons. No impingement mortality data reported.
Limited information available on technology, which is not modified
traveling screens.
Summary report containing data from various studies and facilities.
Some acceptable impingement mortality data identified in this report
were instead obtained from their original source or from a later
update (2007) of this report instead.
No impingement data. (Report contains only detailed descriptions of
intake testing facilities.)
Study offish diversion using non-BTA technology (sound generating
system)
Used course mesh traveling screens missing modified features to
make it BTA.
Data for barrier net, did not use modified traveling screen technology.
No impingement data.
No impingement data.
No impingement data.
D
D
-------
ID
42
43
44
45
46
47
48
49
50
51
52
DCN
DON 5-4388
DCN 5-4394
DCN 5-4327
DCN 5-441 9
DCN 4-4002V-
R12
DCN 10-5435
DCN 5-431 4
DCN 5-4396
Comment 1.32
inNFR
DCN 5-4325
DCN 5-4371
Authors
Stone and Webster
Engineering
Corporation
Roberto Pagano and
Wade H.B. Smith -
Mitre Corporation
Beak Consultants
Incorporated
Tennessee Valley
Authority
Lawler, Matusky &
Skelly Engineers
Stone and Webster
Environmental
Technology and
Services
AWH Turnpenny,
JM Fleming, KP
Thatcher & R Wood
(Fawley Aquatic
Research
Laboratories, Ltd.)
David E. Bailey,
Jules J. Loos, Elgin
S. Perry
Drs. P. A. Henderson
and R.M. Seaby
Beak Consultants,
Inc.
Mote Marine
Laboratory
Title
Evaluation of the Eicher Screen at
Elwha Dam: Spring 1990 Test
Results
Recent Developments in
Techniques to Protect Aquatic
Organisms at the Water Intakes of
Steam-Electric Power Plants
Post-Impingement Fish Survival at
Dunkirk Steam Station 1998-1999
A State-of-the-Art Report on Intake
Technologies
Intake Technologies: Research
Status
Evaluation of the Modular Inclined
Screen at the Green Island
Hydroelectric Project: 1995 Test
Results
Trials of an Acoustic Fish Deterrent
System at Hartlepool Power Station
Studies of Cooling Water Intake
Structure Effects at Potomac
Electric Power Company
Generating Stations
Technical Evaluation of USEPA's
Proposed Cooling Water Intake
Regulations for New Facilities
Post-Impingement Fish Survival at
Huntley Steam Station (Winter and
Fall, 1999)
Fine Mesh Screen (FMS)
Optimization Study
Date"
1991
1977
2000
1976
1989
1996
1995
Unk.
2000
2000
1987
Impingement Data
Data
Pre-
sent?
No
Yes*
Yes*
Yes
Yes*
No
Yes
Yes*
Yes
Yes*
No
Used?
No
Yes
No
No
No
No
No
Yes
Reasons for Use/Non-Use
No impingement data. Data represent fish diversion associated with
a prototype installation operated under highly controlled conditions.
Impingement data from Surry and Barney Davis Power Stations
represent fish bucket screens and double-exit traveling screens,
respectively but the holding time was too short since data only
represent mortality immediately following impingement.
Mortality data were reported at 24-hour post-impingement for
Ristroph-type dual flow traveling screens.
Data represent laboratory studies and do not represent traveling
screens with BTA features.
Summary report of impingement mortality data from various facilities.
Typically, only immediate impingement mortality is provided, or
technologies were not traveling screens with BTA features.
Potentially useful data was duplicative of other study data.
No impingement data.
Study measured how fish impingement rate (rather than mortality) is
reduced when a non-BTA technology (acoustic deterrent system) is
in place.
Impingement counts, but not mortality, are reported for several
facilities. Technologies were not fully documented (but were clearly
not traveling screens with BTA features).
Only estimated annual fish impingement reported to assess impact of
pumping rate on impingement at various plants. Technologies not
fully documented to verify use of BTA.
Mortality data were reported at 24-hour post-impingement for
Ristroph-type dual flow traveling screens.
No impingement data.
to
-------
ID
53
54
209
55
56
66
57
58
97
59
60
61
DCN
DON 5-4378
DCN 10-5442
DCN 2-01 3L-
R1
DCN 5-4006
DCN 6-2074
DCN 2-01 7A-
R7
DCN 5-4337
DCN 5-4354
(also DCN 5-
4003)
DCN 10-5448
DCN 5-4343
Authors
John S. Stevens, Jr.,
and Milton S. Love
Consolidated Edison
Company of New
York
American Electric
Power Service
Corporation
TG Ringger,
Baltimore Gas &
Electric
EPRI
Delta Fish Facilities
Technical
Coordination
Committee
E.S. Fritz
Latvaitis et al.
Edited by Loren
Jensen
Department of Fish
and Game and the
Department of
Water Resources
Title
Chapter 1 0: San Onofre Units 2
and 3 316(b) Demonstration, The
Effectiveness of the Fish Return
System
Arthur Kill Generating Station
Diagnostic Study and Post-
Impingement Viability Substudy
Report
Cardinal Plant Demonstration
Document
Investigations of Impingement of
Aquatic Organisms at the Calvert
Cliffs Nuclear Power Plant, 1975-
1995
Review of Entrainment Survival
Studies: 1970-2000
Preliminary Design Criteria for the
Peripheral Canal Intake Fish
Facilities
Cooling Water Intake Screening
Devices Used to Reduce
Entrainment and Impingement
Third National Workshop on
Entrainment and Impingement -
Impingement Studies at Quad-
Cities Station, Mississippi River
Memorandum Report on the
Peripheral Canal Fish Return
Facilities
Date"
Unk.
1996
1981
2000
2000
1981
1980
1976
1971
Impingement Data
Data
Pre-
sent?
Yes
Yes*
Yes
Yes*
No
No
No
Yes*
No
Used?
No
No
No
No
No
Reasons for Use/Non-Use
Impingement mortality measured at 96 hours. Technology involved
louvers and bypass angled screens. Fish survival evaluation was for
all fish in bypass system with only a small portion being returned from
screens. Technology is not BTA.
Arthur Kill mortality data were collected at 24-hour post-impingement
at Screens No. 24 and 31 which featured Ristroph-type dual flow
traveling screens but data was not fully representative of time periods
of approximately one year Mortality data reported in a chapter
comparing performance at Arthur Kill and Indian Point plants were
limited.
Impingement data consist solely of impinged fish, with no mortality
information. Traveling screens were not modified.
Annual impingement counts and mortality are estimated. Traveling
screens were not modified.
No impingement data.
No impingement data.
No impingement data.
Losses of standing crop to impingement are reported rather than
impingement mortality. Data are estimated. Traveling screens were
not modified.
No impingement data.
-------
ID
62
63
64
65
69
70
71
73
74
DCN
DON 10-5448
DCN 5-4381
DCN 5-4334
DCN 10-5453
DCN 5-4346
DCN 5-4347
DCN 5-4374
DCN 5-4301
DCN 5-4330
Authors
Thomas & Miller.
Edited by Loren
Jensen
Ronald Raschke -
US EPA
James B. McLaren
Richard Horwitz
Q.E. Ross; D.J.
Dunning; J.K.
Meneszees;
M.J.Kenn Jr.;
G.Tiller
Q.E. Ross; D.J.
Dunning; J.K.
Meneszees;
M.J.Kenn Jr.;
G.Tiller
N.J. Thurberand
D.J Jude, Great
Lakes and Marine
Waters Center,
University of
Michigan
A.W.H. Turnpenny
Rob Brown
Title
Third National Workshop on
Entrainment and Impingement -
Impingement Studies at Oyster
Creek Generating Station, Forked
River, New Jersey, from Sept. to
Dec. 1975
Finding of Fact for Biological and
Environmental 316 Demonstration
Studies
Fish Survival on Fine Mesh
Travelling Screens
Lecture Notes on Coastal and
Estuarine Studies - Ecological
Studies in the Middle Reach of the
Chesapeake Bay - Impingement
Studies
Reducing Impingement of Alewives
with High Energy Frequency Sound
at a Power Plant Intake in Lake
Ontario
Response of Alewives to High
Frequency Sound at a Power Plant
Intake on lake Ontario
Impingement Losses at the DC
Cook Nuclear Power Plant During
1975-1982 With a Discussion of
Factors Responsible and Possible
Impact on Local Populations
Fish Return at Cooling Water
Intakes
The potential of strobe lighting as a
cost-effective means for reducing
impingement and entrainment
Date"
1976
1983
2000
1987
1996
1993
1985
1992
2000
Impingement Data
Data
Pre-
sent?
Yes*
Yes
Yes*
Yes*
Yes
Yes
Yes
Yes*
No
Used?
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
Traveling screens were not modified. Reported impingement
mortality data appear to represent only immediate mortality, although
report notes delayed mortality was examined.
Only total annual impingement counts were reported for selected
species, and not impingement mortality. No information given to
verify use of BTA.
Potentially useful data was duplicative of other study data
Traveling screens were not modified with BTA features. Only
immediate mortality following impingement appears to be reported in
most cases.
Study used non-BTA technology (sound generating system)
Study used non-BTA technology (sound generating system)
Estimated annual impingement totals without noting mortality. Used
non-BTA technology (traveling screens with no modification).
Only ranges of impingement mortality are presented for one facility,
for each of five levels offish resistance/sensitivity. Insufficient
information was available to assess BTA use.
No impingement data. Study used non-BTA technology (strobe
lighting system)
1
-------
ID
75
76
77
78
79
80
81
82
84
85
86
DCN
DON 5-4302
DCN 5-4303
DCN 5-4304
DCN 5-4300
DCN 5-4357
DCN 5-4307
DCN 10-5465
DCN 10-5466
DCN 5-4335
DCN 5-4333
DCN 6-5068
Authors
A.W.H. Turnpenny
A.W.H. Turnpenny
A. Turnpenny, J.
Nedwell
A.W.H. Turnpenny,
C.J.L Taylor
Fish and Wildlife
Service - US
Department of the
Interior
H.H. Reading
D.T. Michaud, E.P.
Taft
E.R. Guilfoos, R.W.
Williams, T.E.
Rourke, P.B.
Latvaitis, J.A.
Gulvas, R.H. Reider
C. Ehrler, C.
Raifsnider
John P. Ronafalvy,
R. Roy Cheesman,
William M. Matejek
Lawler, Matusky,
and Skelly
Title
Exclusion of Salmonid Fish From
Water Intakes
Bubble Curtain Fish Exclusion
Trials at Heyshaam 2 Power
Station
Fish Behaving Badly
An Assessment of the Effect of the
Sizewell Power Stations on Fish
Populations
Impacts of Power Plant Intake
Velocities on Fish
Retention of Juvenile White
Sturgeon, Acipenser
Transmontanus, by Perforated
Plate and Wedgewire Screen
Materials
Recent Evaluations of Physical and
Behavioral Barriers for Reducing
Fish Entrainment at Hydroelectric
Plants in the Upper Midwest
Six Years of Monitoring the
Effectiveness of a Barrier Net at the
Ludington Pumped Storage Plants
on Lake Michigan (Waterpower 95)
Evaluation of the Effectiveness of
Intake Wedgewire Screens
Circulating water traveling screen
modifications to improve impinged
fish survival and debris handling at
Salem Generating Station
Lovett Generating Station
Gunderboom Evaluation Program
Date"
1988
1993
2002
2000
1977
1982
2000
1995
2000
2000
1996
Impingement Data
Data
Pre-
sent?
No
Yes*
No
Yes*
No
No
No
No
No
Yes*
Yes
Used?
No
No
No
No
Reasons for Use/Non-Use
No impingement data.
Data correspond to "fish catch on screens." Study assessed non-
BTA technology (bubble curtain, with no information on screens
used).
No impingement data.
Impingement data expressed as "losses to the fishery" as biomass
rather than mortality. Facility does not appear to use BTA.
No impingement data.
Laboratory study that did not collect impingement mortality data.
No impingement data.
No impingement data.
No impingement data.
Impingement data for only one species (weakfish) were available.
Data was not representative of one year.
No mortality data. No information on type of traveling screens used
(focus is on Gunderboom evaluation).
D
D
-------
ID
94
95
96
98
99
100
101
102
103
DCN
DON 5-4344
DCN 5-4332
DCN 5-4331
DCN 5-4338
DCN 5-4339
DCN 5-4340
DCN 5-4341
DCN 5-4342
DCN 5-4360
Authors
KeySpan
Corporation
Andrew E. Jahn,
Kevin T. Herbinson
David R. Sager,
Charles H. Hocutt,
Jay R. Stauffer Jr.
Delta Fish Facilities
Technical
Coordinating
Committee
Delta Fish Facilities
Technical
Coordinating
Committee
Delta Fish Facilities
Technical
Coordinating
Committee
Delta Fish Facilities
Technical
Coordinating
Committee
Delta Fish Facilities
Technical
Coordinating
Committee
CD Goodyear, Great
Lakes Fishery
Laboratory
Title
Screenwash return water
modification study, Glennwood and
Port Jefferson Power Stations
Designing a light-meditated
behavioral barrier to fish
impingement and a monitoring
program to test its effectiveness at
a coastal power station
Avoidance behavior of Morone
americana, Leiostomus xanthurus
and Brevooritia tyrannus to strobe
light as a method of impingement
mitigation
Justification for Abandonment of
Further Consideration of the Louver
Fish Screen for an Intake Facility
for the Peripheral Canal
Horizontal Traveling Fish Screen
Status
Justification for Abandonment of
Further Consideration of the
Filtration Concept for an Intake
Facility for the Peripheral Canal
Justification for Eliminating from
Further Consideration the
Horizontal Rotary Drum Screen for
the Peripheral Canal
Justification for Proceeding with an
"Off-River" Intake Concept for the
Peripheral Canal
Evaluation of 31 6(b)
Demonstration: Detroit Edison's
Monroe Power Plant
Date"
2002
2000
2000
1981
1980
1979
1979
1979
1978
Impingement Data
Data
Pre-
sent?
Yes
No
No
No
Yes
No
No
No
Yes*
Used?
No
No
No
Reasons for Use/Non-Use
Only monthly totals reported. No information given on type of
technology. No mortality data.
No impingement data. Study used non-BTA technology (light used
as stimulus for attracting fish to bypass).
No impingement data. Laboratory study that used non-BTA
technology (strobe light and bubble curtain deterrents).
No impingement data
Laboratory study. No mortality data or information given on whether
traveling screens were modified.
No impingement data
No impingement data
No impingement data
No mortality data. No indication that traveling screens were modified.
Data appear to be estimates.
-------
ID
104
105
106
107
108
109
110
111
112
113
DCN
DON 5-4362
DCN 5-4376
DCN 6-5037
DCN 6-5046O
DCN 5-4409
DCN 5-441 8
DCN 5-4305
DCN 5-441 1
DCN 5-4336
DCN 4-1 326
Authors
LW Barnthouse et
al, Oak Ridge
National Laboratory
JH Balletto and HW
Brown, American
Electric Power
Stone & Webster
Engineering
John Young, William
Dey, Steven Jinks,
Nancy Decker,
Martin Daley, John
Carnright
Consumers Power
Company
Tennessee Valley
Authority, Division of
Water Resources
New York Power
Authority
Southern Energy
California
California
Departments of Fish
and Game and
Water Resources
American Electric
Power
Title
The Impact of Entrainment and
Impingement on Fish Populations
in the Hudson River Estuary
(Volume II)
Kammer Plant Demonstration
Document for PL 92-500 Section
316(b)
Biological and Engineering
Evaluation of a Fine-Mesh Screen
Intake for Big Bend Station Unit 4
Evaluation of Variable Pumping
Rates as a Means to Reduce
Entrainment Mortalities
1991 Annual Report Describing
Performance of Deterrent Net
System at JR Whiting
A Biological Evaluation of Fish
Handling Components of a Water
Intake Screen Designed to Protect
Larval Fish
Conditional Entrainment Mortality
Rates for Seven Taxa of Fish at
Water Intakes on the Hudson River
Best Technology Available 1999
Technical Report for the Pittsburg
and Contra Costa Power Plants
A Fish Protection Facility for the
Proposed Peripheral Canal
Philip Sporn Plant Demonstration
Project for PL 92-500 Section
316(b)
Date"
1982
1980
1980
2003
1992
1979
1998
2000
1981
1980
Impingement Data
Data
Pre-
sent?
Yes
Yes
Yes*
No
Yes*
No
No
No
No
Yes
Used?
No
No
No
No
No
Reasons for Use/Non-Use
Only estimated monthly data provided. No specific technology data
provided.
Only estimated total impingement counts were reported, with no
mortality data. Traveling screens were not modified to include BTA
features.
Interim report of data originating from a controlled study involving a
prototype. While technology involved dual flow traveling screens with
baskets and mortality data were reported at 0 and 48 hours post-
impingement, the fine mesh screen technology is not BTA. It is also
not clear whether the 48-hour data correspond to the same
organisms as evaluated at 0 hours.
No impingement data
No mortality data. Technology is not modified traveling screens.
No impingement data
No impingement data
No impingement data
No impingement data
No mortality data. Technology is not modified traveling screens.
-------
ID
114
115
116
118
119
122
123
124
125
126
127
DCN
DON 5-4306
DCN 5-4008
DCN 10-5491
DCN 10-5492
DCN 10-5493
DCN 5-4404
DCN 6-5050
DCN 4-1 51 6
DCN 6-5046E
DCN 6-5046F
Authors
Bay-Delta Fishery
Project
Stephen B.
Weisburg, William
H. Burton, Eric A.
Ross, Fred Jacobs
HDR/LMS
Edward Taft,
Thomas Horst, and
John Dowling -
Stone and Webster
Engineering
Corporation
E. P. Taft - Stone
and Webster
Environmental
Services
Versar, Inc.
U.S. NRC, Office of
Standards
Development
NJ DEP; Prepared
by ESSA
Technologies
David Baily, Jules
Loos, Ann
Wearmouth, Pat
Langley, Elgin Perry
Steven M. Jinks,
Nancy Decker,
William Dey, John
Young, Douglas
Dixon
Title
Roaring River Slough Fish Screen
Evaluation, 1984
The Effects of Screen Slot Size,
Screen Diameter, and Through-Slot
Velocity on Entrainment of
Estuarine Ichthyoplankton through
Wedgewire Screens
Salem NJPDES Permit Renewal
Application February 2006
Biological Evaluation of a Fine-
Mesh Traveling Screen for
Protecting Organisms
Evaluation of Strobe Lights for Fish
Diversion at the York Haven
Hydroelectric project
Evaluation of the 316 Status of
Delaware Facilities with Cooling
Water Discharges
U.S. Nuclear Regulatory
Commission Regulatory Guide
Review of Portions of NJPDES
Renewal Application for the
PSE&G Salem Generating Station
Effectiveness, Operation and
Maintenance, and Costs of a
Barrier Net System for
Impingement Reduction at the
Chalk Point Generating Station
A Review of Impingement Survival
Studies at Steam-Electric Power
Stations
Date"
1984
1984
2006
1981
1992
1990
1975
2000
2003
Unk.
Impingement Data
Data
Pre-
sent?
No
No
No
Yes*
No
No
No
Yes*
Yes*
Yes
Used?
No
No
No
No
Reasons for Use/Non-Use
No impingement data
No impingement data
No impingement data
Data originate from a controlled study involving a prototype. While
technology involved dual flow traveling screens with baskets the fine
mesh screen technology is not BTA. Also, mortality data were
reported at 0 and 48 hours post-impingement, it is not clear whether
the 48-hour data correspond to the same organisms as evaluated at
0 hours.
No impingement data. (Technology focuses on avoidance/deterrence
involving strobe lights, sound.)
No impingement data
No impingement data
Non-BTA technology used (sound deterrent)
No mortality data. Focus is on evaluating barrier net effectiveness.
Summary report. Studies/facilities and corresponding data not clearly
identified.
-------
ID
128
129
130
131
132
133
134
135
DCN
DON 6-5043
DCN 6-5046D
DCN 5-4361
DCN 5-4384
DCN 5-4358
DCN 5-4386
DCN 5-4399
DCN 5-4400
Authors
David Bruzek,
Selvakumaran
Mahadevan, Mote
Marine Laboratory
Mark F. Strickland,
James E. Mudge
J. Boreman, L.W.
Barnthouse, D.S.
Vaughan, C.P.
Goodyear, S.W.
Christensen, K.D.
Kumar, B.L. Kirk, W.
Van Winkle
Dr. Y.G. Mussalli et
al (Stone &
Webster), M.P.
McNamera et al
(NUSCO)
Douglas Hjorth, Fred
Winchell, John
Downing, Don
Cochran, Rose
Perry (Stone &
Webster)
Lawler Matusky &
Skeller Engineers
Tenera
Environmental
Services
Tenera
Environmental
Services
Title
Fine Mesh Screen Survivability
Study Big Bend Unit 4 Tampa Bay
Electric Company
Selection and Design of Wedge
Wire Screens and a Fixed-Panel
Aquatic Filter Barrier System to
Reduce Impingement and
Entrainment at a Cooling Water
Intake Structure on the Hudson
River
The Impact of Entrainment and
Impingement on Fish Populations
in the Hudson River Estuary for Six
Fish Populations Inhabiting the
Hudson River Estuary
Feasibility Study of Cooling Water
System Alternatives to Reduce
Winter Flounder Larval Entrainment
at Millstone Units 1, 2, and 3
Preliminary Assessment of Fish
Entrainment at Hydropower
Projects - A Report on Studies and
Protective Measures
Field Testing of Behavioral Barriers
for Fish Exclusion at Cooling-Water
Intake Systems
Moss Landing Power Plant
Modernization Project 316(b)
Resource Assessment
Diablo Canyon Power Plant 316(b)
Demonstration Report
Date"
1986
2003
1982
1993
1995
1988
2000
2000
Impingement Data
Data
Pre-
sent?
Yes
No
No
No
No
Yes
Yes
No
Used?
No
No
No
Reasons for Use/Non-Use
Non-BTA technology (fine mesh traveling screens)
No impingement data
No impingement data
No impingement data
No impingement data
No mortality data. Technology is non-BTA (various behavioral
barriers).
Mortality considered only for 4 minutes holding time. Data given for
one species (striped bass).
While impingement is noted in the report, no impingement data are
summarized in tables. Traveling screens were not modified.
-------
ID
136
137
138
139
140
141
142
143
144
145
DCN
DON 5-431 7
DCN 6-501 6
DCN 6-5046H
DCN 6-5046P
DCN 6-5046Q
DCN 5-4363
DCN 5-4366
DCN 5-4369
DCN 5-4370
DCN 5-4372
Authors
Lawler, Matusky &
Skelly Engineers
Marine Resource
Advisory Council
Isabel C. Johnson
and Steve Moser
J R Nedwell, AWH
Turnpenny, and D
Lambert
E. P. Taft, Thomas
C. Cook, Jonathan
L. Black, Nathaniel
Olkien
R. H. Gray, T. L.
Page, E. G. Wolf, M.
J. Schneider
(Batelle)
Thomas J. Edwards,
William H. Hunt,
Larry E. Miller,
James J. Sevic
Stone & Webster
Engineering
Corporation
United Engineers &
Constructors
Florida Power &
Light Company
Title
Intake Debris Screen
Postimpingement Survival
Evaluation Study: Roseton
Generating Station 1990
(Portion of Chapter 3 and selected
tables from Chapter 5)
Effects of Power Plants on Hudson
River Fish
Fish Return System Efficacy and
Impingement Monitoring Studies for
JEA's Northside Generating
System
Objective Design of Acoustic Fish
Deterrent Systems
Fish Protection Technologies for
Existing Cooling Water Intake
Structures and their Costs
A Study of Fish Impingement and
Screen Passage at Hanford
Generation Project - A Progress
Report
An Evaluation of the Impingement
of Fishes at Four Duke Power
Company Steam Generating
Facilities
Final Report: Biological Evaluation
of a Modified Traveling Screen
Mystic Station - Unit No. 7
Edgar Energy Park Clean Water
Act Sections 316(a) & 316(b)
Demonstration
Assessment of the Impacts of the
St Lucie Nuclear Generating Plant
on Sea Turtle Species Found in the
Inshore Waters of Florida
Date"
1991
2000
Unk.
2003
2003
1975
1976
1981
1990
1995
Impingement Data
Data
Pre-
sent?
Yes*
No
Yes*
No
No
Yes*
Yes
Yes*
No
No
Used?
No
No
No
No
Yes
Reasons for Use/Non-Use
While impingement mortality was reported up to 48 hours post-
impingement for dual-flow traveling screens with screen baskets,
data is not representative of one year.
No impingement data
Impingement mortality data presented in summary form only.
No impingement data
No impingement data
No impingement mortality data reported. Traveling screens are not
modified.
No impingement mortality data reported. Traveling screens are not
modified.
Modified traveling screens. Mortality data reported for multiple
holding times
No impingement data
No impingement data. (Only turtle species were considered.)
-------
ID
146
147
148
149
151
152
153
154
155
156
157
158
159
DCN
DON 6-5057
DCN 5-4308
DCN 5-4309
DCN 5-4310
DCN 5-431 5
DCN 5-431 6
DCN 10-5523
DCN 10-5524
DCN 10-5525
DCN 10-5526
DCN 10-5527
DCN 10-5528
DCN 10-5529
Authors
American Society of
Civil Engineers
Ronald J. Decoto
Brian D. Quevlog
Randall L. Brown,
Dan B. Odenweller
AWH Turnpenny,
PA Henderson
AWH Turnpenny, K
P Thatcher, R
Wood, P H
Loeffelman
Tom M. Pankratz
Stone & Webster
Engineering
Corporation
Malcolm E. Brown
Lawrence W. Smith,
David E. Ferguson
T. E. Crumlish
W. S. Lifton
Brian N. Hanson
Title
Design of Water Intake Structures
for Fish Protection
1974 Evaluation of the Glenn-
Colusa Irrigation District Fish
Screen
An Inventory of Selected Fish
Screens in California
A Fish Protection Facility for the
Proposed Peripheral Canal
Design and Testing Specification
for a Deterrent Bubble Barrier for
Heysham Power Stations 1 & 2
Experiments on the Use of Sound
as a Fish Deterrent
Screening Equipment Handbook
Assessment of Downstream
Migrant Fish Protection
Technologies for Hydroelectric
Application
Progress Report on Profile Wire
Intake Screen Testing Forked
River, New Jersey
Cleaning and Clogging Tests of
Passive Screens in the
Sacramento River, California
Extended Abstract - Engineering
Aspects of Screen Testing on the
St. Johns River, Palatka, Fla.
Extended Abstract - Biological
Aspects of the Screen Testing of
the St Johns River, Palatka, Fla.
Studies of Three Cylindrical Profile-
wire Screens Mounted Parallel to
Flow Direction
Date"
1982
1978
1981
1981
1992
1993
1995
1986
1979
1979
1979
1979
1979
Impingement Data
Data
Pre-
sent?
Yes*
No
No
No
No
No
No
No
No
No
No
No
No
Used?
No
Reasons for Use/Non-Use
Impingement mortality data present but information on technology
used is insufficient to verify BTA.
No impingement data (bypass data were reported instead).
No impingement data
No impingement data
No impingement data
No impingement data
No impingement data
No impingement data.
No impingement data.
No impingement data.
No impingement data.
No impingement data.
No impingement data
D
D
-------
CO
ID
160
162
163
164
165
166
167
168
169
206-
A
170
171
DCN
DON 10-5530
DCN 10-5531
DCN 10-5532
DCN 10-5533
DCN 10-5534
DCN 10-5535
DCN 10-5536
DCN 5-4379
DCN 5-4379
DCN 5-4379
DCN 5-4379
Authors
James M.
Wiersema, Dorothy
Hogg, and Lowell J.
Eck
R. W. Crippen
Lawrence R. King,
Jay B. Hutchison Jr.,
Thomas G. Huggins
Thomas R.
Thathom, David L.
Thomas, Gerald J.
Miller
T. L. Page, D. A.
Neitzel, R. H. Gray
Yusuf G. Mussalli,
Edward P. Taft,
Peter Hoffman
Brian N. Hanson,
Wiliam H. Bason,
Barry E. Beitz, Kevin
E. Charles
L.S. Murray and T.S.
Jinnette
D.A. Tomljanovich,
J.H. Heuer, and
C.W. Voigtlander
J.H. Heuer and D.A.
Tomljanovich
B.N.Hanson, W.H.
Bason, B.E. Beitz,
and K.E. Charles
Title
Biofouling Studies in Gaslveston
Bay - Biological Aspects - Abstract
Impacts of Three Types of Power
Generating Discharge Systems on
Entrained Plankton
Impingement Survival Studies on
White Perch, Striped Bass, and
Atlantic Tomcod at Three Hudson
River Power Plants
Survival of Fishes and
Macroinvertibrates Impinged at
Oyster Creek Generating Station
Comparative Fish Impingement at
Two Adjacent Water Intakes on the
Mid-Columbia River
Engineering Implications of New
Fish Screening Concepts
A Practical Intake Screen which
Substantially Reduces the
Entrainment and Impingement of
Early Life Stages of Fish
Survival of Dominant Estuarine
Organisms Impinged on Fine-Mesh
Traveling Screens at the Barney M.
Davis Power Station
Investigations on the Protection of
Fish Larvae at Water Intakes Using
Fine-Mesh Screening
A Study on the Protection of Fish
Larvae at Water Intakes Using
Wedge-Wire Screens
Practicality of Profile-Wire Screen
in Reducing Entrainment and
Impingement
Date"
1979
1977
1977
1977
1977
1977
1977
1977
1977
1987
1977
Impingement Data
Data
Pre-
sent?
No
No
Yes*
Yes*
Yes
No
Yes
Yes*
Yes*
No
Yes*
Used?
No
No
No
No
No
No
No
Reasons for Use/Non-Use
No impingement data.
No impingement data.
Technology description did not mention modified screen features.
Technology is not BTA. Traveling screens are not modified.
Technology is not BTA. Traveling screens are not modified.
No impingement data.
Laboratory study
Holding time is too short. Only immediate mortality was observed (for
up to 10-15 minutes post-impingement).
While percent impingement mortality was documented, this is a
laboratory study that did not involve evaluation of modified traveling
screens.
Laboratory study. "Bypassed" data are reported rather than
impingement data.
Laboratory study.
-------
ID
173
174
175
176
177
178
179
180
181
182
183
184
185
DCN
DON 5-4350
DCN 7-4561
DCN 10-5543
DCN 10-5544
DCN 10-5545
DCN 10-5546
DCN 10-5547
DCN 10-5548
DCN 8-4501
DCN 10-5550
DCN 10-5551
DCN 7-4507
Authors
EA Science and
Technology
Acres International
Corporation
Dames and Moore
Alliant Energy
B.D. GieseandK.N.
Mueller
Tennessee Valley
Authority
Tennessee Valley
Authority
Tennessee Valley
Authority
Normandeau
Associates, Inc.
Industrial Bio-Test
Laboratories, Inc.
Carolina Power &
Light Company
Wisconsin Electric
Power Company
Title
Results of entrainment and
impingement monitoring studies at
the Westchester RESCO facility,
Peekskill, New York
Report on fish entrainment study:
November 1993 to November
1994, Glens Falls
Seminole Plant Units 1&2 31 6b
Study Report
Final Environmental Impact
Statement: Ottumwa Generating
Station
Section III Prairie Island Nuclear
Generating Plant Environmental
Monitoring Report - 2002 Annual
Report
Biological Effects of Intake Browns
Ferry Nuclear Vol 1 Summary of
the Evaluation of the Browns Ferry
Nuclear Plant Intake Structure
316(a) and 316(b) Demonstration
Cumberland Steam Plant - Volume
5
316(a) and 316)b) Demonstration:
John Sevier Steam Plant
Impingement and Entrainment at
the Cooling Water Intake Structure
of the Delaware City Refinery, April
1998-March2000
A Baseline/Predictive
Environmental Investigation of
Lake Wylie
Brunswick Steam Electric Plant
Cape Fear Studies Interpretive
Report
Oak Creek Power Plant Final
Report Intake Monitoring Studies
Date"
1987
1995
1979
1978
2002
1978
1977
1977
2000
1974
1985
1976
Impingement Data
Data
Pre-
sent?
Yes
No
Yes
No
Yes
No
No
No
Yes
No
Yes
Yes
Used?
No
No
No
No
No
No
Reasons for Use/Non-Use
Only percentages of impinged data represented by certain species,
and total fish impinged, were reported. No impingement mortality
reported.
No impingement data
Technology involved fixed screens rather than traveling screens. No
impingement mortality data reported.
No impingement data.
No impingement mortality data. Traveling screens are not modified.
No impingement data.
No impingement data
No impingement data
No impingement mortality data. Traveling screens are not modified.
No impingement data.
Potentially useful data was duplicative of other study data
No impingement mortality data. Traveling screens are not modified.
-------
ID
186
187
188
189
190
191
192
193
201
194
DCN
DON 7-4508
DCN 10-5554
DCN 7-451 2
DCN 7-451 3
DCN 10-5557
DCN 10-6806
DCN 10-6801
DCN 10-6813
DCN 10-6804
Authors
Wisconsin Electric
Power Company
Delmarva Power &
Light Company
Applied Biology, Inc.
Geo-Marine, Inc.
Equitable
Environmental
Health, Inc.
EPRI
EPRI
EPRI
EPRI
Title
Port Washington Power Plant Final
Report Intake Monitoring Studies
Vienna Power Station Prediction of
Aquatic Impacts of the Proposed
Cooling Water Intake A Section
316(b) Demonstration
Impingement Monitoring Program
South Carolina Public Service
Authority Winyah Plant Final
Report
316b Demonstration Report for the
Arkansas Eastman Plant on the
White River
Meramec Power Plant Entrainment
and Impingement Effects on
Biological Populations of the
Mississippi River
Field evaluation of wedgewire
screens for protecting early life
stages at cooling water intake
structures: Chesapeake Bay
studies
Laboratory evaluation of modified
Ristroph traveling screens for
protecting fish at cooling water
intakes
Fish Protection at Cooling Water
Intake Structures: A Technical
Reference Manual
Design considerations and
specifications for fish barrier net
deployment at cooling water intake
structures
Date"
1976
1982
1977
1981
1976
2006
2006
2007
2006
Impingement Data
Data
Pre-
sent?
Yes
No
Yes
No
Yes
No
Yes*
Yes*
No
Used?
No
No
No
No
Yes
Reasons for Use/Non-Use
No impingement mortality data. Traveling screens are not modified.
No impingement data.
No impingement mortality data. Traveling screens are not modified.
No impingement count or mortality data reported. Limited information
is given on technology used.
No impingement mortality data. Traveling screens are not modified.
No impingement data
Laboratory study
This is a summary report of data from multiple studies. Chapter 2
contains impingement data, some of which originate from other
reviewed reports. Data appear from Brunswick, Indian Point,
Potomac, Prairie Island, Roseton, Dunkirk and Huntley that were
utilized in the impingement mortality limitations. Impingement
mortality data from other sources were not used due to non-BTA
technology or corresponding to 0 hours post-impingement.
No impingement data.
Oi
-------
ID
195
196
197
198
199
200
202
203
204
205
DCN
DON 10-6802
DCN 10-6814
DCN 10-6970
DCN 10-6971
DCN 4-1 682
DCN 10-5567
DCN 10-5568
DCN 10-5569
DCN 10-5570
DCN 10-5571
Authors
EPRI
EPRI
EPRI
EPRI
Robert W. Davis,
John A. Matousek,
Michael J. Skelly,
and Milton R.
Anderson
Applied Science
Associates
S.L Blanton, D.A.
Neitzel, and C.S.
Abernethy
W. Bengeyfield
M.D. Bowen, S.M.
Siegfried, C.R.
Listen, A.J. Hess
and C.A. Karp
D.L.Breitburg and
T.A.Thoman
Title
Laboratory evaluation of fine-mesh
traveling water screens for
protecting early life stages offish at
cooling water intakes
Latent impingement mortality
assessment of the Geiger Multi-
Disc screening system at Potomac
River Generating Station
The role of temperature and
nutritional status in impingement of
clupeid fish species
Cooling Water Intake Structure
Area-of-lnfluence Evaluations for
Ohio River Ecological Research
Program Facilities
Biological Evaluation of Brayton
Point Station Unit 4, Angled Screen
Intake
Ichthyoplankton Monitoring Study
Deployment of a Gunderboom
System at Lovett Generating
Station Units, 1998
Washington Phase II Fish
Diversion Screen Evaluations in the
Yakima River Basin, 1997
Evaluation of a Temporary Screen
to Divert Fish at Puntledge
Generating Station
Fish Collections and Secondary
Louver Efficiency at the Tracy Fish
Collection Facility
Calvert Cliffs Nuclear Power Plant
Finfish Survival Study
Date"
2008
2007
2008
2007
1988
1999
1998
1992
1998
1986
Impingement Data
Data
Pre-
sent?
Yes*
Yes*
No
No
Yes
No
No
No
No
Yes*
Used?
No
No
No
No
Reasons for Use/Non-Use
Laboratory study
Potentially useful data was duplicative of other study data
No impingement data.
No impingement data.
Impingement survival data is reported as total for 18 month period.
Data covers a period substantially more than 12 months and
therefore not representative of one year.
No impingement data.
No impingement data. Non-BTA screen technology used to promote
fish diversion.
No impingement data. Evaluation of temporary barrier net.
No impingement data.
Assessed technologies included dual-speed, Beauderey, and control
traveling screens. Impingement mortality data appear to represent
only immediate post-impingement. Holding time is too short.
D
D
-------
ID
206
207
208
210
211
212
213
214
215
216
217
DCN
DON 10-5572
DCN 10-5573
DCN 10-5574
DCN 7-4504
DCN 9-4664
DCN 10-5577
DCN 10-5578
DCN 10-5579
DCN 7-451 1
DCN 7-0009
DCN 7-4520
Authors
V. Brueggemeyer,
D.Cowdrick, K.
Durrell, S.
Mahadevan and D.
Bruzek
Beak Consultants
Incorporated
Carolina Power and
Light Company
NALCO
Environmental
Sciences
Wapora Inc
Hugh Barwick
J. P. Buchanan, D.L.
Dycus, H.R.
Gwinner, and J.M.
Roberts, Jr.
Stone and Webster
Engineering
Corporation, Boston,
MA
Wapora
Tetra Tech
Western Illinois
Power Cooperative
Title
Full-scale Operational
Demonstration of Fine Mesh
Screens at Power Plant Intakes
Dunkirk Station Biological Studies
Brunswick Steam Electric Plant:
1984 Biological Monitoring Report
Dean H Mitchell Station 316(b)
Demonstration
Studies of screen impingement and
egg and fry entrainment at the
Joppa Illinois Electric Generating
Station
Fish Impingement at Oconee
Nuclear Station
Aquatic Environmental Conditions
in Chickamauga Reservoir During
Operation of Sequoyah Nuclear
Plant, Sixth Annual Report
Studies to Alleviate Potential Fish
Entrapment Problems (Volume 1 of
2)
316 (a) and (b) Studies on the
Grand River
Small facility ichthyoplankton
entrainment sampling for the
development of the 31 6(b) Phase
III Rule for cooling water intake
structures
Fish impingement studies at Pearl
Station-February 1977-January
1978
Date"
1998
1988
1985
1976
1976
1990
1987
1977
1977
2004
1978
Impingement Data
Data
Pre-
sent?
Yes*
Yes*
Yes*
Yes
Yes
Yes
No
No
Yes
No
Yes
Used?
No
No
Yes
No
No
No
No
No
Reasons for Use/Non-Use
Mortality data are reported only immediately following impingement.
Technology does not appear to be BTA.
Impingement mortality data correspond to Beaudrey traveling
screens with no modified features or fish return system.
.3/8 in mesh fixed diversion screen at inlet; Impingement survival
data includes fish fry captured on modified fine mesh screens
Impingement mortality not reported. Traveling screen technology not
modified.
Impingement mortality not reported. Traveling screen technology not
modified.
Impingement mortality not reported. Modified traveling screens not
used.
No impingement data.
No impingement data associated with field studies.
No impingement mortality data reported. No information given on
technology used at the specified plants.
No impingement data.
Impingement mortality was not assessed. No information given on
the technology used.
-------
00
ID
218
219
220
221
200-
A
201-
A
202-
A
203-
A
204-
A
205-
A
DCN
DON 7-4505
DCN 7-451 6
DCN 7-4557
DCN 10-5586
DCN 11 -5522
DCN 10-5588
DCN 10-5589
DCN 10-5590
DCN 10-5591
DCN 10-5592
Authors
Foster Wheeler
Environmental
Corporation
Carolina Power and
Light
EA Science
Alden Research
Laboratory and
Stone & Webster
Engineering
Corporation
Stone & Webster
Engineering
Corporation
Donald E. Clark and
Douglas P. Cramer
D.P. Cramer
P.M Cumbieand
J.B. Banks
Stone & Webster
Environmental
Services
Texas Instruments
Incorporated
Title
Comanche Peak Steam Electric
Station Units 1 and 2 31 6 (b)
Demonstration
HB Robinson Steam Electric Plant
316 Demonstration Study
Bayway Refinery impingement and
entrainment study for 316(b) of the
Clean Water Act
Laboratory Evaluation of Fish
Protective Devices at Intakes
Alternative Intake Designs for
Reducing Fish Losses, Mystic
Station - Unit 7
Evaluation of the Downstream
Migrant Bypass System - T.W.
Sullivan Plant, Willamette Falls
Evaluation of a Louver Guidance
System and Eicher Screen for Fish
Protection at the T.W. Sullivan
Plant in Oregon
Protection of Aquatic Life in Design
and Operation of the Cope Station
Water Intake and Discharge
Structures
Proposal for Services to Perform
1992 Blueback Herring
Environmental Studies at the Little
Falls Hydroelectric Project, Little
Falls, New York
Initial and Extended Survival of
Fish Collected from a Fine Mesh
Continuously Operating Traveling
Screen at the Indian Point
Generating Station
Date"
1995
1976
1995
1981
1979
1993
1997
1997
1991
1978
Impingement Data
Data
Pre-
sent?
Yes
Yes
Yes
No
Yes
No
No
No
No
Yes
Used?
No
No
No
No
Yes
Reasons for Use/Non-Use
Traveling screens are not modified. No impingement mortality results
reported.
Traveling screens are not modified. No impingement mortality results
reported.
Traveling screens are not modified. No impingement mortality results
reported.
No impingement data. Several technologies were evaluated under
laboratory conditions, including fish diversion and bypass, and
behavioral barriers, but not modified traveling screens. For angled
screens, mortality associated with diversion was reported only at 96
hours.
While this report documents the findings of several studies assessing
impingement mortality associated with traveling screens. Screens
utilized low pressure spray wash but used trash lips rather than fish
buckets. Technology is not BTA
No impingement data - mortality data (>48 hour holding time) were
associated with negotiating a downstream migrant bypass system
rather than screen impingement.
No impingement data - 48-hour mortality data were associated with
negotiating a downstream migrant bypass system rather than screen
impingement.
No impingement data.
No impingement data.
Impingement mortality associated with Ristroph traveling screens are
reported.
-------
ID
207-
A
208-
A
209-
A
210-
A
221
222
223
224
225
226
227
DCN
DON 10-5593
DCN 10-5594
DCN 10-5595
DCN 10-5596
DCN 6-5004B
DCN 11 -5453
DCN 11 -5440
DCN 11 -5441
DCN 11 -5442
DCN 11 -5443
DCN 11-5444
DCN 11 -5530
Authors
Larry E. Week,
Victor C. Bird, and
R. Eugene Geary
Michael Wert
Fred Winchell, Ned
Taft, Tom Cook and
Charles Sullivan
Thomas Plante,
Michael Feldhausen,
Dennis Olsen and
David Michaud
EPRI
ASA Analysis &
Communication, Inc.
Carolina Power and
Light Company
Carolina Power and
Light Company
Carolina Power and
Light Company
Progress Energy
Carolinas, Inc
Progress Energy
Carolinas, Inc
ASA
Title
Effects of Passing Juvenile
Steelhead, Chinook Salmon, and
Coho Salmon Through an
Archimedes' Screw Pump
Hydraulic Model Evaluation of the
Eicher Passive Pressure Screen
Fish Bypass System
Research Update on the Eicher
Screen at Elwha Dam
Maintenance Requirements of a
Fish Barrier Net System
Laboratory Evaluation of
Wedgewire Screens for Protecting
Early Life Stages of Fish at Cooling
Water Intakes
Evaluation of Impingement Survival
on the HydroloxTM Traveling Water
Screen at the E.F. Barrett
Generating Station October 2007 -
June 2008 (2008)
Brunswick Steam Electric Plant
1985 Biological Monitoring Report
Brunswick Steam Electric Plant
1986 Biological Monitoring Report
Brunswick Steam Electric Plant
1987 Biological Monitoring Report
Brunswick Steam Electric Plant
2008 Biological Monitoring Report
Brunswick Steam Electric Plant
2009 Biological Monitoring Report
Hudson Generating Station 316(b)
Study Report 2009-201 1
Date"
1989
1988
1993
1997
2003
2008
1986
1987
1988
2009
2011
2011
Impingement Data
Data
Pre-
sent?
No
Yes
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Used?
No
No
Yes
No
No
No
No
No
No
Reasons for Use/Non-Use
No impingement data. This report documents the outcome of
controlled experiments of screw pump pass-through.
Laboratory study of Eicher screens rather than modified traveling
screens.
"Passage survival" after 96 hours was reported rather than screen
impingement survival or mortality.
No impingement data. Focus was on assessing the functionality and
performance (biofouling) of a prototype barrier net system.
Laboratory study. No impingement mortality data reported.
Hydrolox traveling water screen, 0.25" x 0.3" smooth plastic screen
with modified screen features
Survival data not representative of one year and 1985 data reported
for selected species only
Survival data not representative of one year and 1986 data reported
for selected species only.
Survival data not representative of one year and 1987 data reported
for selected species only.
Survival estimates based on previous study results.
Survival estimates based on previous study results
Timeframe of latent survival data is not be representative of one year
CO
-------
IV)
o
ID
228
229
230
231
232
233
234
235
236
237
238
239
240
DCN
DON 11 -5449
DCN 11 -5450
DCN 11 -5451
DCN 11-5532
DCN 6-5038
DCN 6-5039
DCN 6-5040
DCN 6-5041
DCN 6-5042
DCN 11 -5531
DCN 11 -5533
DCN 11 -5476
DCN 11 -5507
Authors
Marine Research
Inc.
Normandeau
Associates, Inc.
Normandeau
Associates, Inc.
PSEG/AKRF
Carolina Power and
Light Company
Carolina Power and
Light Company
Carolina Power and
Light Company
Carolina Power and
Light Company
Carolina Power and
Light Company
New York State Gas
and Electric
(NYSEG)
D.L Bigbee, R.G.
King, and K.M.
Dixon
Ecological Analysts,
Inc.
Consolidated Edison
Company of New
York, Inc.
Title
Post-impingement Survival Study
Manchester Street Station January
1 996 p February 1997
Impingement Monitoring at
Manchester Street Station 2005
Impingement Monitoring at
Manchester Street Station 2006
Special Study Report-Salem
Generating Station Estimated
Latent Impingement Mortality
Rates: Updated Pooled Estimates
Using Data from 1995, 1997, 1998,
1999, 2000 and 2003
Brunswick Steam Electric Plant
2000 Biological Monitoring Report
Brunswick Steam Electric Plant
1999 Biological Monitoring Report
Brunswick Steam Electric Plant
1998 Biological Monitoring Report
Brunswick Steam Electric Plant
1997 Biological Monitoring Report
Brunswick Steam Electric Plant
1996 Biological Monitoring Report
Somerset Coal-Fired Power Station
Aquatic Ecology Monitoring
Program
Survival of Fish Impinged on a
Rotary Disk Screen
A Biological Evaluation of Modified
Vertical Traveling Screens.
Biological Evaluation of a Ristroph
Screen at Indian Point Unit 2
Date"
1997
2006
2007
2011
2001
2000
1999
1998
1997
1981
2010
1982
1985
Impingement Data
Data
Pre-
sent?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Used?
Yes
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Reasons for Use/Non-Use
3/8 in Ristroph-type traveling screens with fish buckets, low pressure
spray continuous operation and separate fish return.
Impingement data only. No latent survival data presented
Impingement data only. No latent survival data presented
Modified Ristroph screens, 1/4 x 1/2 mesh, smooth screens,
baskets, etc. Aggregated data not representative of one year period.
Survival data not representative of one year and 2000 data reported
for selected species only
Survival data not representative of one year and 1999 data reported
for selected species only.
Survival data not representative of one year and 1998 data reported
for selected species only.
Survival data not representative of one year and 1997 data reported
for selected species only.
Survival data not representative of one year and 1996 data reported
for selected species only.
Report is a description of future study plans
Rotary screen (WIP screen)
3/8" front wash traveling screens that have been retrofitted with fish
collection trough (with water) and low- and high-pressure wash
systems.
Modified traveling screens, 3/8" mesh, low pressure wash, fish
protection and collection features.
D
D
-------
ID
241
242
243
244
245
246
247
248
249
DCN
DON 11 -5508
DCN 11 -5499
DCN 11 -5482
DCN 5-4334
DCN 11 -5463
DCN 11 -5500
DCN 11 -5490
DCN 11 -5461
DCN 11 -5529
Authors
Consolidated Edison
Company of New
Ynrk Inn
Goeman, T J
New York State
Electric and Gas
Corporation, Stone
& WphQtpr
Engineering
Corporation, and
Auld Environmental
Associates.
McClaren, J.B. and
L.R. Tuttle
Northeast Utilities
Service Company
Northeast Utilities
Service Company
Normandeau
Associates, Inc.
EA Engineering,
Science, and
Technology, Inc.
Colder Associates,
Inc.
Title
Survival of Fish Impinged on a
Ristroph-type Traveling Screen at
the Indian Point Generating
Station, Summer and Fall, 1985
Fish survival at a cooling water
intake designed to minimize
mortality
Kintigh/Somerset Aquatic
Monitoring Program 1989 Annual
Report.
Fish Survival on Fine Mesh
Traveling Screens
The Effectiveness of the Millstone
Unit 3 Fish Return System
Progress Report on the MNPS Fish
Return Systems
Roseton Generating Station 1 994
Evaluation of Post Impingement
Survival and Impingement
Entrainment and Impingement
Studies at Oyster Creek Nuclear
Generating Station
Fish Return System Optimization
Study: Summary of Results and
Discussion, Considerations, and
Recommendations
Date"
1986
1984
1990
1999
1987
1994
1995
1986
1999
Impingement Data
Data
Pre-
sent?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Used?
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Reasons for Use/Non-Use
Modified traveling screens, 3/8" mesh, low pressure wash, fish
protection and collection features.
Modified traveling screens with fish trays and sluiceways. Low
pressure wash, followed by high pressure.
Fine mesh (1 mm) traveling screens with fish trays and return, low
pressure spray, sluice trough. Includes 2000 feet offshore velocity
cap intake.
Summary of 1985, 1986, and 1989 studies. Potentially useful data
was duplicative of other study data.
Fine mesh (3/16"), fish trays, low and high pressure spray, fish
sluiceway return
"Fine" mesh (3/8"), fish trays, low and high pressure spray, fish
sluiceway return. New screens and re-angled fish sprayers (per
improvements made after 1986 study).
Dual flow traveling screens replaced 2 (2C & 2D) of 8 conventional
screens in 1990. In April 1993 dual flow screen 2D was replaced
with a dual flow screen modified to reduce impingement and
increase survival. Dual flow screens are described as having low &
high pressure spray; 3.2 x 12.7 mm smoothtex mesh, vortex
suppressing fish buckets. The only difference described is the shape
of the baffles that guide water to the screen surface
Conventional screens replaced with Ristroph traveling screens with
low and high pressure spray, fish buckets, in 1983-4
Traveling screens with high and low pressure spray, fish pans
spaced 4ft, continuous screen operation tested
IV)
-------
^
IV)
ID
DCN
DON 11 -5400
DCN 11 -5401
DCN 11 -5402
DCN 11 -5403
DCN 11 -5404
DCN 11 -5405
DCN 11 -5406
DCN 11 -5407
DCN 11 -5409
DCN 11-
5409B
DCN 11 -5410
Authors
Burns & McDonnell
Engineering
Company, Inc
Burns & McDonnell
Engineering
Company, Inc.
Burns & McDonnell
Engineering
Company, Inc.
Burns & McDonnell
Engineering
Company, Inc.
Burns & McDonnell
Engineering
Company, Inc.
Burns & McDonnell
Engineering
Company, Inc.
Burns & McDonnell
Engineering
Company, Inc.
Burns & McDonnell
Engineering
Company, Inc.
ENSR Corporation
Basin Electric Power
Cooperative
ENSR Corporation
Title
Section 316(b) Impingement
Mortality Characterization Study for
the Burlington Generating Station
Section 316(b) Impingement
Mortality Characterization Study for
the Dubuque Generating Station
Section 316(B) Impingement
Mortality And Entrainment
Characterization Study For The
Edgewater Generating Station
Section 316(b) Impingement
Mortality Characterization Study for
the Fox Lake Generating Station
Section 316(b) Impingement
Mortality Characterization Study for
the Lansing Generating Station
Section 316(B) Impingement
Mortality Characterization Study
For The M.L. Kapp Generating
Station
Section 316(b) Impingement
Mortality Characterization Study for
the Nelson Dewey Generating
Station
Section 316(B) Impingement
Mortality And Entrainment
Characterization Study For The
Prairie Creek Generating Station
Impingement Mortality and
Entrainment Characterization Study
(IMECS) Basin Electric - Leland
Olds Station, ND
Spreadsheet: "Basin_Database
Missouri River CWISs (3)"
Basin Electric Power Cooperative
Bismarck, North Dakota - 316(b)
Proposal for Information Collection
Leland Olds Station
Date"
2007
2007
2007
2009
2007
2007
2007
2007
2008
2006
2005
Impingement Data
Data
Pre-
sent?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Used?
No
No
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
-------
ID
DCN
DON 11 -5411
DCN 11 -541 2
DCN 11 -541 3
DCN 11 -541 6
DCN 11 -541 7
DCN 11 -541 8
DCN 11 -541 9
DCN 11 -5420
DCN 11 -5421
Authors
Shaw
Environmental, Inc.
Shaw Environmental
& Infrastructure, Inc
ARCADIS
Colder Associates
Inc.
EPRI- ASA Analysis
& Communication,
Inc.
EPRI -ASA Analysis
& Communication,
Inc.
EPRI -ASA Analysis
& Communication,
Inc.
EPRI -ASA Analysis
& Communication,
Inc. - Alden
Randall B. Lewis,
Greg Seegert
Title
LPDES SECTION 316(B)
SUBMITTAL -Teche Power Station,
237 Newman Street Baldwin, St.
Mary Parish, Louisiana 70514
LPDES SECTION 316(B)
SUBMITTAL - Coughlin (Formally
Evangeline) Power Station, 2180
St. Landry Highway, St. Landry,
Evangeline Parish, Louisiana
Consumers Energy Company
Comprehensive Demonstration
Study - J.H. Campbell Generating
Complex
Source Water And Cooling Water
Data And Impingement Mortality
And Entrainment Characterization
For Belle River Power Plant
Belews Creek Steam Station -
2006-2007 Impingement Study And
Assessment Of Adverse
Environmental Impact
McGuire Nuclear Station - 2006-
2007 Impingement Study and
Assessment of Adverse
Environmental Impact
Marshall Steam Station - 2006-
2007 Impingement Study and
Assessment of Adverse
Environmental Impact
Information Submitted for Best
Professional Judgment §316(b)
Decision-making for Duke Energy's
Oconee Nuclear Station
Entrainment and impingement
studies at two power plants on the
Wabash River in Indiana
Date"
2009
2010
2008
2008
2009
2010
2009
2008
2000
Impingement Data
Data
Pre-
sent?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Used?
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
IV)
CO
-------
^
IV)
ID
DCN
DON 11 -5422
DCN 11 -5423
DCN 11 -5424
DCN 11 -5426
DCN 11 -5425
DCN 11 -5427
DCN 11 -5429
DCN 11 -5430
DCN 11 -5431
Authors
Georgia Power
Georgia Power
Georgia Power
Georgia Power
Georgia Power
Georgia Power
ENSR Corporation
Burns & McDonnell
Engineering
Company, Inc.
Burns & McDonnell
Engineering
Company, Inc.
Title
Spreadsheet "Preliminary summary
of impinged organisms at Georgia
Power - Plant Hammond, 19-20
October 2004 through the 6-7
October 2005 sampling event."
Spreadsheet "GA Power
Impingement data - Ga Power -
Harllee Branch 2004"
Spreadsheet "GA Power
Impingement data - Ga Power -
Kraft 2005"
Spreadsheet "GA Power
Impingement data - Ga power -
McManus 2004"
Spreadsheet "GA Power
Impingement data - Ga power -
Mclntosh 2005"
Spreadsheet "GA Power
Impingement data - Ga power -
Mitchell 2004 "
Fish Impinged at Basin Electric
Leland Olds Station, GRE Stanton
Station, and Minnkota M.R. Young
Missouri River Station, Cooling
Water Intake Structures - Final
Data Summary (June 2005 to June
2006)
Section 316(b) Impingement
Mortality Characterization Study for
the Carl E. Bailey Generating
Station
Section 316(b) Impingement
Mortality Characterization Study for
the John L. McClellan Generating
Station
Date"
2005
2004
2006
2005
2005
2006
2006
2007
2007
Impingement Data
Data
Pre-
sent?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Used?
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
No holding time
Does not evaluate BTA technology
D
D
-------
IV)
01
ID
DCN
DON 11 -5432
DCN 11 -5433
DCN 11 -5434
DCN 11 -5435
DCN 11 -5436
DCN 11 -5446
DCN 11 -5447
DCN 11 -5448
Authors
Burns & McDonnell
Engineering
Company, Inc.
EA Engineering,
Science, and
Technology
EA Engineering,
Science, and
Technology
HDR Engineering
Swanson
Environmental, Inc.
Mike Godfrey,
Alabama Power
Burns & McDonnell
Engineering
Company, Inc.
PBS&J and Texas
Municipal Power
Agency
Title
Section 316(b) Impingement
Mortality Characterization Study for
the Thomas B. Fitzhugh
Generating Station
Seminole Generating Station
Konawa Lake 31 6(B) Assessment
Seminole Generating Station
Konawa, Oklahoma - Phase II
316(B) Impingement Mortality
Characterization Study
Information Collection Data Report
in Compliance with Section 316(b)
Phase Il-Requirements of the
Clean Water Act For Hoot Lake
Plant Otter Tail Power Company
Cooling Water Intake Monitoring
Program - January 1976 -
December 1976 - Otter Tail Power
Company - Hoot Lake Generating
Station
Letter from Mike Godfrey, Alabama
Power, to Lisa A. Biddle, USEPA.
Re: Proposed National Pollutant
Discharge Elimination System Rule
for Cooling Water Intake Structures
at Existing Facilities and Phase I
Facilities, Docket ID No. EPA-HQ-
OW-2008-0667; Dated October 2,
2011
Section 316(b) Impingement
Mortality Characterization Study for
the Sunbury Generation Station
TPDES 02120 For Texas Municipal
Power Agency's Gibbons Creek
Steam Electric Station
Supplemental Information For
316(B) Determination Of Best
Technology Available
Date"
2007
2010
2007
2006
1977
2011
2008
2006
Impingement Data
Data
Pre-
sent?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Used?
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
No impingement data
Does not evaluate BTA technology
Does not evaluate BTA technology
-------
ID
DCN
DON 11 -5456
DCN 11 -5457
DCN 11 -5452
DCN 11 -5408
DCN 11 -5474
DCN 11 -5465
DCN 11 -5466
DCN 11 -5467
DCN 11 -5468
DCN 11 -5469
DCN 11 -551 6
Authors
Jacobs Engineering
UK Ltd
Kinectrics North
America Inc.
Shaw
Environmental, Inc.
ENSR Corporation
Horwitz, R. J.
Public Service
Electric and Gas
Company
Public Service
Electric and Gas
Company
Public Service
Electric and Gas
Company
Public Service
Electric and Gas
Company
Public Service
Electric and Gas
Company
White, J.C. and M.L
Brehmer
Title
UK Best Practice fish screening
trials study
Valley Power Plant: Impingement
Mortality And Entrainment
Characterization Study Report
2006-2007 Impingement &
Entrainment Study NRG Huntley
Power, LLC. Huntley Steam Station
CWA§316(b) Impingement
Mortality and Entrainment
Characterization Study (IMECS):
Astoria Generating Station
Impingement Studies (Chapter 8)
In: Lecture Notes on Coastal and
Estuarine Studies. Ecological
Studies in the Middle Reach of the
Chesapeake Bay: Calvert Cliffs.
1999 Annual Report
1995 Annual Report
1996 Annual Report
1997 Annual Report
1998 Annual Report
Third National Workshop on
Entrainment and Impingement —
Eighteen-Month Evaluation of the
Ristroph Traveling Fish Screens
Date"
Unk.
2008
2007
2007
1987
2000
1996
1997
1998
1999
1977
Impingement Data
Data
Pre-
sent?
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Used?
No
No
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
No impingement data
Does not evaluate BTA technology
No holding time
No holding time
Does not evaluate BTA technology
No holding time
No holding time
No holding time
No holding time
No holding time
No holding time
D
D
-------
ID
DCN
EPA-HQ-OW-
2008-0667-
2989
DCN 11 -551 3
DCN 11 -5504
DCN 11 -5455
DCN 11 -551 2
DCN 11 -5488
DCN 11 -5528
DCN 11 -5477
DCN 11 -5458
EPA-HQ-OW-
2008-0667-
2955
Authors
Gulf Power
Freshwater
Physicians, Inc.
Dominion Nuclear
Connecticut, Inc.
Kinectrics Inc.
Lawler, Matusky &
Skelly Engineers
Texas Instruments
Incorporated
Ecological Services
Environmental
Science and
Engineering, Inc.
Environmental
Consulting Services,
Inc and Lawler,
Matusky, and Skelly,
Inc
First Energy
Alabama Power
Company
Title
Plant Scholz 316(b) Impingement
Mortality Characterization Study
Belle River Power Plant Fish
Entrainment and Impingement
Study, 1990-1991
Millstone Power Station Survival
Study Results for the Aquatic
Organism Sluiceway at Unit 2
Bay Shore Power Plant Fish
Entrainment And Impingement
Study Report
Brayton Point Station Unit No. 4
Aquatic Biological Monitoring
Program Angled Screen Intake
Evaluation, First Annual Interim
Report
Collection Efficiency and Survival
Estimates of Fish Impingement on
a Fine Mesh Continuously
Operating Traveling Screen at the
Indian Point Generating Station for
the Period 8 August to November
1978
An Assessment of the Fish Return
System at the Jacksonville Electric
Authority Northside Generating
Station, Jacksonville, Florida
1995 Supplemental Impingement
Studies with an Assessment of
Intake-Related Losses at Salem
Generating Station.
Impingement and Entrainment Data
from Bay Shore
316(b) Impingement and
Survivability Study: Plant Gorgas
Date"
2009
1991
2001
2007
1985
1979
1985
1996
2008
2012
Impingement Data
Data
Pre-
sent?
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Used?
No
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Duplicative of study already in the data
Limited Impingement Data
Limited Data
Data not representative of one year
Does not evaluate BTA technology
Draft report and limited data
-------
IV)
00
ID
DCN
DON 11 -5521
DCN 11 -5464
DCN 11 -5487
DCN 5-4329
DCN 11 -5471
DCN 11 -551 7
DCN 11 -5481
DCN 11 -551 8
DCN 11 -5525
DCN 11 -5486
Authors
Anderson, R.D.
Northeast Utilities
Service Company
Ecological Analysts,
Inc.
Tom Thompson
Ecological Analysts,
Inc.
Ecological Analysts,
Inc.
Lawler, Matusky &
Skelly Engineers
Love, M.S., M.
Shandhu, J. Stein,
K. Herbinson, R.H.
Moore, M. Mullins,
and J.S. Stephens
D.M. Chase
Ecological Analysts,
Inc
Title
Impingement of Organisms at
Pilgrim Nuclear Power Station
The effectiveness of the Millstone
Unit 1 Sluiceway in Returning
Impinged Organisms to Long Island
Sound
Impingement survival studies at the
Roseton and Danskammer Point
Generating Stations: progress
report. August 1978
Intake modifications to reduce
entrainment and impingement at
Carolina Power & Light Company's
Brunswick Steam Electric Plant
Southport NC
Bowline Point Generating Station
Entrainment and Impingement
Studies
Moss Landing Power Plant Cooling
Water Intake Structures 316(b)
Demonstration
Intake Technology Review Oswego
Steam Station Units 1 -6.
Analysis of Fish Diversion
Efficiency and Survivorship in the
Fish Return System at San Onofre
Nuclear Generating Station
Survival Rates of Fishes and
Macroinvertebrates Impinged on
the Vertically Revolving Intake
Screens of a Power Plant on
Galveston Bay, Texas
Bowline Point Generating Station
entrainment abundance and
impingement survival studies, 1981
annual report
Date"
1985
1986
1978
2000
1976
1983
1992
1989
1978
1982
Impingement Data
Data
Pre-
sent?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Used?
No
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Duplicative of study already in the data
Holding time exceeded 96 hr
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Holding time exceeded 96 hr
D
D
-------
ID
DCN
DON 11 -5491
DCN 11 -5462
DCN 12-5457
DCN 11 -5520
DCN 11 -5495
EPA-HQ-OW-
2008-0667-
2955
DCN 11 -541 4
DCN 11 -541 5
DCN 11 -5428
Authors
Ecological Analysts,
Inc.
Tatham, T. R.,
Danila, D. J.,
Thomas, D. L.
Consolidated Edison
Company of New
York, Inc.
Reider, R.H.
Ecological Analysts,
Inc.
Alabama Power
Company
Consumer Power
Company
Consumers Energy
Company - The
Detroit Edison
Company
ENSR Corporation
Title
Bowline Point Impingement
Survival Studies 1975-1978
Overview Report
Ecological Studies for the Oyster
Creek Generating Station Progress
Report for the Period September
1975- August 1976 Volume One
Preliminary Investigations into the
Use of a Continuously Operating
Fine Mesh Traveling Screen to
Reduce Ichthyoplankton
Entrainment at Indian Point
Generating Station
Alternative Screen Wash Survival
Study at the Monroe Power Plant
April-September, 1983
Impingement Survival Studies at
Roseton and Danskammer Point
Generating Station Progress
Report December 1977
Biological Information Collection
Results: Plant Gadsden Steam
Electric Generating Company
An Evaluation of Cylindrical
Wedge-wire Screens at Cooling
Water Intakes in Lake Michigan
Consumers Energy Company and
The Detroit Edison Company -
Ludington Pumped Storage
Project; Project No. 2680 - Annual
Report of Barrier Net Operation for
2010
Proposal for Information Collection
Stanton Station
Date"
1979
1977
1977
1984
1977
2008
1979
2010
2006
Impingement Data
Data
Pre-
sent?
Yes
Yes
Yes
Yes
Yes
No
No
No
No
Used?
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
Holding time exceeded 96 hr
Does not evaluate BTA technology
Duplicative of study already in the data
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
No impingement data
Does not evaluate BTA technology
Does not evaluate BTA technology
IV)
CO
-------
CO
o
ID
DCN
DON 11 -5438
DCN 11 -5492
DCN 11 -551 9
DCN 11 -5496
DCN 11 -5485
DCN 11 -5511
DCN 11 -5503
DCN 11 -5478
DCN 11 -5501
Authors
Tom Thompson
Ecological Analysts,
Inc.
Lawler, Matusky, &
Skelly Engineers
Ecological Analysts,
Inc.
Muessig, P. H.;
Hutchison, J. B. Jr.;
King, L. R.; Ligotino,
R. J., and Daley, M
Ecological Analysts,
Inc.
Ecological Analysts,
Inc.
Foster, J. R. and T.
J. Wheaton
Stone & Webster
Corp.
Title
Intake Technologies Used at the
Brunswick Steam Electric Plant to
Achieve a Reduction in
Impingement Mortality to a Level
Similar to Closed Cycle Cooling
Comprehensive Study of the
Survival of Fishes Commonly
Impinged at the Bowline Point
Electrical Generating Station
Hudson River, New York
Danskammer Point Angled Screen
Facility: Evaluation
Estimates of Impingement Mortality
for Selected Fish Species at the
Danskammer Point Generating
Station 1975-1980
Survival of fishes after
impingement on traveling screens
at Hudson River power plants. IN:
Science, Law, and Hudson River
Power Plants: A Case Study in
Environmental Impact Assessment.
American Fisheries Society
Evaluation of the Effectiveness of a
Continuously Operating Fine Mesh
Traveling Screen for Reducing
Ichthyoplankton Entrainment at the
Indian Point Generating Station
Impact of the Cooling Water Intake
at the Indian River Power Plant: A
316 (b) Evaluation
Losses of Juvenile and Adult
Fishes at the Nanticoke Thermal
Generating Station due to
Entrapment, Impingement and
Entrainment.
Larval Impingement Survival Study,
Prairie Island Nuclear Generating
Plant
Date"
2011
1982
1986
1982
1988
1979
1978
1981
1980
Impingement Data
Data
Pre-
sent?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Used?
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
Duplicative of study already in the data
Duplicative of study already in the data
No impingement data
No impingement data
No impingement data
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
No impingement data
-------
ID
DCN
DON 11 -5480
DCN 11 -5470
DCN 11 -5524
EPA-HQ-OW-
2008-0667-
2256
EPA-HQ-OW-
2008-0667-
2243
EPA-HQ-OW-
2008-0667-
2229
EPA-HQ-OW-
2008-0667-
2140
DCN 12-5414
DCN 4-1 327
DCN 12-5436
DCN 11 -5480
Authors
Kuhl and Mueller
Heimbuch, D.G.
D.L. Breitburg and
D.A. Reiner
MACTEC
Engineering and
Consulting
Tenera
Environmental
Services
ENSR
Corporation/AECOM
Tenera
Environmental
Services
Donald R.
Dummermuth
John Balletto and
Sheldon Zabel
Loos, J.L.
Kuhl and Mueller
Title
Annual Report on Fine Mesh
Vertical Traveling Screens
Impingement Survival Study.
Clean Water Act §31 6 (b)
Demonstration; Appendix F and
Appendix G
Finfish and Blue Crab Impingement
and Survival at the H.A. Wagner
Generating Station for Baltimore
Gas and Electric Company, Final
Report
Impingement Monitoring, Eastman
Chemical Company (Kingsport,
Tennessee)
Open Coastal Power Plants Using
Once-Through Cooling
Impingement Mortality and
Entrainment Characterization Study
(IMECS) Montana Dakota Utilities -
RM Heskett
CWA§316(b) Impingement
Mortality and Entrainment
Characterization Study: 2009-2010
Summary Report (Year 4)
A Report on the Environmental
Impact of the Cooling Water Intake
Structure at the Dover Municipal
Light Plant
Clifty Creek Station Demonstration
Document
Evaluation of Benefits to PEPCO of
Improvements in the Barrier Net
and Intake Screens at Chalk Point
Station Between 1984 and 1985
Fine Mesh Vertical Traveling
Screens Impingement Survival
Study
Date"
1988
1999
1988
2011
2011
2008
2011
1989
1978
1986
1988
Impingement Data
Data
Pre-
sent?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Used?
No
No
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
Not a representative study
Duplicative of study already in the data
No impingement data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
Does not evaluate BTA technology
Duplicative of study already in the data
-------
^
IV)
ID
DCN
DCN 2-01 3L-
R10
DCN 5-4379
DCN 9-4668
DCN 7-451 5
DCN 10-5448
EPA-HQ-OW-
2008-0667-
2140
EPA-HQ-OW-
2008-0667-
3080
EPA-HQ-OW-
2008-0667-
3080
EPA-HQ-OW-
2008-0667-
3080
EPA-HQ-OW-
2008-0667-
3080
DCN 7-4522
DCN 12-5431
Authors
Energy Impact
Associates, Inc.
Sharma, R.K. and
J.B. Palmer
Tenera
Environmental
Services
Krueger, J.F., J.O.
Rice, and R.G. Otto
Loren D, Jensen
Tenera
Environmental
Services
Oklahoma Gas &
Electric Company
Oklahoma Gas &
Electric Company
Oklahoma Gas &
Electric Company
Oklahoma Gas &
Electric Company
Bruce, D.
Commonwealth
Edison Company
Title
Fish Impingement and Entrainment
Studies at Tanners Creek Power
Plant
Larval Exclusions for Power Plant
Cooling Water Intakes
Logan Generation Plant Intake
Screen Performance Entrainment
Study
Screen Monitoring at Allen Station
Third National Workshop on
Entrainment and Impingement
Section 316(b) Research and
Compliance
CWA§316(b) Impingement
Mortality and Entrainment
Characterization Study: 2010-2011
Summary Report (Year 5)
Horseshoe Lake Generating
Station 2006 Phase 1 1 31 6(b)
Impingement Mortality
Characterization Study
Muskogee Generating Station 2006
Phase II 316(b) Impingement
Mortality Characterization Study
Seminole Generating Station 2006
Phase II 316(b) Impingement
Mortality Characterization Study &
Assessment
Sooner Generating Station 2006
Phase II 316(b) Impingement
Mortality Characterization Study
1986 Newton Lake Impingement
Monitoring: Progress Report
316(b) Demonstration La Salle
Generating Station Makeup Water
Intake System
Date"
1978
1978
1996
1974
1976
2011
2007
2007
2007
2007
1986
1976
Impingement Data
Data
Pre-
sent?
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Used?
No
No
No
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
No impingement mortality data
Contains impingement mortality data (from other studies)
No impingement mortality data
Does not evaluate BTA technology
Duplicative of study already in the data
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
No impingement mortality data
No impingement mortality data
-------
ID
DCN
DON 7-4529
DCN 7-4523
DCN 12-5423
DCN 12-5446
DCN 12-5430
DCN 12-5445
DCN 5-4349
DCN 12-5444
DCN 7-4527
DCN 12-5443
DCN 12-5442
DCN 8-4504
DCN 12-5411
Authors
NUS Corporation
EA Engineering
Roy F. Weston, Inc.
R. Goosney
Geo-Marine, Inc.
Taft, E.P. and Y.G.
Mussalli
Sunset Energy Fleet
LLC
Ott, R.F. et al
Alabama Power
Company
Heimbuch, D.G.
Stone & Webster
Engineering
Corporation
Parsons
Engineering Science
South Carolina
Public Service
Authority
Title
316(b) Demonstration for the
Sherburne County Generating
Plant Units 1 and 2 on the
Mississippi River Near Becker,
Minnesota
316(b) Monitoring at Newton Power
Station, 1983-84
An Ecological Study of the Effects
of the Brunner Island SES Cooling
Water Intakes
An Efficient Diversion/Bypass
System for Atlantic Salmon (Salmo
Salar) Smolt and Kelt in Power
Canals
An Impingement Study at Kentucky
Utilities' Pineville Electric
Generating Station on the
Cumberland River
Angled Screens and Louvers for
Diverting Fish at Power Plants
Application for Certification of a
Major Electric Generating Facility
Arbuckle Mountain Hydro Vertical-
Axis Fish Screens
Barry Steam Electric Generating
Plant 316(b) Demonstration
Biological Efficacy of Intake
Structure Modifications
Biological Evaluation of a Modular
Inclined Screen for Protecting Fish
at Water Intakes
Cooling Water Biofouling Control
Study at Pfizer Inc. - Groton,
Connecticut
Cross Generating Station Cooling
Water Intake Structure 316(b)
Demonstration
Date"
1976
1984
1977
1997
1975
1978
2000
1988
1977
1999
1994
1998
1980
Impingement Data
Data
Pre-
sent?
Yes
Yes
Yes
No
Yes
No
No
No
Yes
Yes
Yes
No
No
Used?
No
No
No
No
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
Duplicative of study already in the data
No impingement mortality data
No impingement mortality data
No impingement mortality data
-------
^
to
ID
DCN
DON 12-5429
DCN 12-5440
DCN 12-5441
DCN 12-5438
DCN 5-4393
DCN 12-5439
DCN 12-5435
DCN 7-4510
DCN 12-5437
Authors
PBS&J
Lawler, Matusky,
and Skelly
Lawler, Matusky,
and Skelly
Northeast Utilities
service Company
Martin Marietta
Environmental
Systems
Mclninch, S.P. and
C.H. Hocutt
Normandeau
Associates, Inc.
Ecological Analysts,
Inc.
Neitzel, D.A., T.J.
Clune, and C.S.
Abernathy
Title
Draft Interim Report Barney M.
Davis Power Station Impingement
and Entrainment Nueces County,
Texas
Effectiveness Evaluation of a Fine
Mesh Barrier Net Located at the
Cooling Water Intake of the
Bowline Point Generating Station
Effectiveness Evaluation of a Fine
Mesh Barrier Net Located at the
Cooling Water Intake of the
Bowline Point Generating Station
1994 Barrier Net
Effectiveness of a Louver Bypass
System for Downstream Passage
of Atlantic Salmon, Smolts, and
Juvenile Clupeids in the Holyoke
Canal, Connecticut River, Holyoke,
MA
Effects of Screen Slot Size, Screen
Diameter, and Through-Slot
Velocity on Entrainment of
Estuarine Ichthyoplankton Through
Wedge-Wire Screens
Effects of Turbidity on Estuarine
Fish Response to Strobe Lights
Efficiency of the Louver System to
Facilitate Passage of Emigrating
Atlantic Salmon Smolts at Vernon
Hydroelectric Station, Spring 1995
Elrama Power Station Entrainment
and Impingement Data Report
Evaluation of Rotary Drum Screens
Used to Project Juvenile Salmonids
in the Yakima River Basin,
Washington, USA
Date"
2007
1994
1996
1997
1984
1987
1996
1978
1990
Impingement Data
Data
Pre-
sent?
Yes
No
No
No
No
No
No
Yes
No
Used?
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
D
D
-------
ID
DCN
DON 12-5432
DCN 12-5410
DCN 12-5412
DCN 12-5413
DCN 12-5428
DCN 12-5419
DCN 1-3075-
BE
DCN 7-4503
DCN 12-5417
DCN 8-4510
DCN 12-5422
DCN 12-5425
DCN 12-5424
DCN 2-01 SI-
RS
DCN 1-3022-
BE
Authors
Patrick, P.M. and
R.S. McKinley
U.S. DOI Fish and
Wildlife Service
USDA Rural
Electrification
Administration
USNRC
Frey, P.J
Dames and Moore
Taft, E.P.
Texas Instruments
Inc.
Rittenhous, R.C.
Union Electric Co.
NALCO
Environmental
Sciences
WAPORA, Inc.
Tampa Electric Co.
The Cincinnati Gas
and Electric Co.
Geo-Marine, Inc.
Title
Field Evaluation of a Hidrostal
Pump for Live Transfer of American
Eels at a Hydroelectric Facility
Final Biological Opinion on
Colorado-Ute Electric Association's
Nuclear Station Upgrade
Final Environmental Impact
Statement Related to the Proposed
Clover Project
Final Environmental Statement
Related to the Operation of River
Bend Station
Finding of Fact for Widows Creek
and Colbert Stream Stations
Fish Entrainment Studies Final
Report
Fish Protection Technologies: A
Status Report
316(b) Demonstration at Bailly
Station Units 7 and 8
Power Plant Cooling Systems:
Trends and Challenges
Callaway Plant Evaluation of
Cooling Water Intake Impacts on
the Missouri River
The Evaluation of Thermal Effects
in the Missouri River Near Cooper
Nuclear Station 31 6 A and B
316(b) Studies at E.D Edwards
Station Final Report
Big Bend Station 31 6
Demonstration
316(b) Demonstration Walter C.
Beckjord and Miami Fort Power
Stations
316(b) Demonstration for the W.H.
Sammis Generating Station
Date"
1987
1992
2004
1985
1976
1993
2000
1976
1979
1986
1975
1981
1977
1979
1978
Impingement Data
Data
Pre-
sent?
No
No
No
No
No
No
No
Yes
No
Yes
No
Yes
No
No
No
Used?
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
-------
ID
DCN
DCN 2-01 3L-
R4
DCN 1-301 6-
BE
DCN 2-01 3L-
R2
DCN 7-4528
DCN 12-5433
DCN 12-5434
DCN 12-5427
DCN 12-5460
DCN 7-4560
DCN 7-451 9
DCN 10-5428
DCN 10-5469
Authors
American Electric
Power Service
Corporation
EA Science and
Technology
JH Balletto,
American Electric
Power
Alabama Power
Company
Donald P. Jarrett
Schuler, V.J., and
I.E. Larson
Chas T. Main, Inc.
McNabb, C.D., C.R.
Listen, and S.M.
Borthwick
Equitable
Environmental
Health, Inc.
Burton, W.H.
Lawler, Matusky,
and Skelly
Lawler, Matusky,
and Skelly
Title
Kyger Creek Station Demonstration
Document
Final Report: Clifty Creek Station
Impingement Study and Impact
Assessment
Tanners Creek Plant
Demonstration Document
Gorgas Steam Electric Generating
Plant 316(b) Demonstration
Hydraulic Evaluation of Traveling
Belt Fish Screens at Weeks Falls
Improved Fish Protection at Intake
Systems
Informational Package on Water
Use, Intake, and Discharge
In-Plant Biological Evaluation of the
Red Bluff Research Pumping Plant
on the Sacramento River in
Northern California: 1 995 and 1 996
Labadie Power Plant Entrainment
and Impingement Effects on
Biological Populations of the
Missouri River
Larval Fish Entrainment at the Fort
Drum HTW Cogeneration Facility,
Fort Drum, New York
Lovett Generating Station
Gunderboom Evaluation Program -
1998
Lovett Generating Station
Gunderboom Evaluation Program -
1996
Date"
1981
1987
1978
1975
1989
1975
1986
1998
1976
1993
1998
1997
Impingement Data
Data
Pre-
sent?
Yes
No
No
Yes
No
No
No
No
Yes
No
No
No
Used?
No
No
No
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
D
D
-------
ID
DCN
DON 12-5421
DCN 2-031 A
DCN 5-4373
DCN 5-4321
DCN 5-4348
DCN 5-4328
DCN 5-4323
DCN 5-431 9
DCN 5-431 8
DCN 5-4320
DCN 5-4359
DCN 5-4356
DCN 7-4556
Authors
MBC Applied
Environmental
Sciences
Mussalli, Y.G..E.P.
Taft III, and J.
Larsen
Hicks, D.B.
Consolidated Edison
Company of New
York, Inc.
Normandeau
Associates, Inc.
Aronsson, Per Olof
Barfuss, S.L. and B.
Savage
Lawler, Matusky,
and Skelly
Normandeau
Associates, Inc.
Lawler, Matusky,
and Skelly
Dycus, DL
Neitzel, D.A., M.A.
Simmons, and D.H.
McKenzie
Reserve Mining
Company
Title
NPDES 1999 Receiving Water
Monitoring Report Haynes and
AES Alamitos LLC Generating
Stations
Offshore Water Intakes Designed
to Protect Fish
Finding of Fact: Green River Steam
Electric Station
Ravenswood Impingement and
Entrainment Report
Bowline Point Generating Station
1998 Impingement Studies
Environmental Effects of Cooling
Water From Ringhals Nuclear
Power Plant
Hydraulic Model Study of Dual-
Flow and Thru-Flow Screens
Arthur Kill Impingement and
Entrainment Report - September
1991 -September 1992
East River Generating Station
Impingement and Entrainment
Report, January Through
December 1993
Astoria Impingement and
Entrainment Studies January 1993-
December 1993
Effects of Various Intake Designs
on Zooplankton Entrainment
A Guidance Manual for the Input of
Biological Information to Water
Intake Structure Design
One-Year Study for 316(b)
Biological Monitoring Final Report
Date"
1999
1980
1976
1993
1999
1993
1998
1993
1993
1994
1983
1981
1982
Impingement Data
Data
Pre-
sent?
No
No
No
Yes
Yes
No
No
Yes
Yes
Yes
No
No
Yes
Used?
No
No
No
No
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
-------
ID
DCN
DON 12-5455
DCN 12-5452
DCN 12-5454
DCN 4-1 488
DCN 10-5553
DCN 12-5426
DCN 10-5591
DCN 12-5456
DCN 8-4567
DCN 7-451 8
DCN 12-5458
DCN 12-5459
Authors
Hugh Smith
Federal Energy
Regulation
Commission
Kynard, B. and C.
Buerkett
Ecological Analysts,
Inc.
Wisconsin Electric
Power Company
Alden Research
Laboratory, Inc.
Stone & Webster
Environmental
Services
Haider, T.R. and
P.H. Nelson
Applied Biology, Inc.
D.T. Turner
Northeast Utilities
service Company
Northeast Utilities
service Company
Title
Operating History of the Puntledge
River Eicher Screen Facility
Order Approving Downstream Fish
Passage
Passage and Behavior of Adult
American Shad in an Experimental
Louver Bypass System
Port Jefferson Generating Station
Entrainment Survival Study
Port Washington Power Plant Final
Report Intake Monitoring Studies
Potential Alternative Fish
Protection Options for the R.E.
Ginna Nuclear Power Plant with
Respect to 31 6(b) BPJ Compliance
Proposal for Services to Perform
1992 Blueback Herring
Environmental Studies at the Little
Falls Hydroelectric Project, Little
Falls, New York
Protection of Juvenile Anadromous
Fish
Report on Studies Conducted in
Compliance with Condition 21 of
the Putnam Plant Site Certification
Report on the Results of
Impingement and Entrainment
Monitoring of Fishes and Fish
Larvae at the Dexter Cogeneration
Facility Windsor Locks, CT
Response of Atlantic Salmon
Smolts to Louvers in the Holyoke
Canal, Spring 1992
Response of Atlantic Salmon
Smolts to Louvers in the Holyoke
Canal, Fall 1992
Date"
1997
1997
1997
1978
1981
2008
1991
1987
1979
1991
1992
1993
Impingement Data
Data
Pre-
sent?
No
No
No
No
Yes
Yes
No
No
No
Yes
No
No
Used?
No
No
No
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
-------
ID
DCN
DON 12-5447
DCN 12-5448
DCN 12-5449
DCN 7-4506
DCN 12-5461
DCN 12-5450
DCN 12-5451
DCN 10-5420
DCN 7-4555
DCN 12-5420
DCN 12-5416
DCN 7-4554
DCN 12-5453
Authors
Patrick, P.M. and
A.E Christie
P.M. Patrick
Normandeau
Associates, Inc.
Energy Impact
Associates, Inc.
American Society of
Civil Engineers
Dorratcaque, D., W.
Porter, and L.
Swenson
McMillen, M.D. and
W. Porter
CCI Environmental
Services
Energy Impact
Associates, Inc.
Northern
Environmental
Services Division
Paul Frey and
Charles Kaplan,
EPA
Wisconsin Electric
Power Company
J. Craig Johnson
and Robert Ettema
Title
Responses of Fish to a Strobe
Light/Air-Bubble Barrier
Responses of Gizzard Shad
(dorosoma cepedianum) to
Different Flash Characteristics of
Strobe Light
The Vernon Bypass Fishtube:
Evaluation of Survival and Injuries
of Atlantic Salmon Smolts
U.S. Steel Corporation Gary Works
Fish Impingement-Entrainment
Study Summary Data Report
Waterpower '95 Proceedings of the
International Conference on
Hydropower
White River Fish Screen Project -
Hydraulic Modeling
White River Fish Screen Project -
Planning and Design
Zooplankton Entrainment Survival
Study - Anclote Power Plant Pasco
County, Florida
Fish Impingement and Entrainment
at West Penn Power Company's
Hatfield Ferry Power Station
Kammer Plant: Fish Impingement
and Entrainment studies
Finding of Fact for Allen Steam
Station
Pleasant Prairie Power Plant: Final
Report on Intake Monitoring
Studies 1980-1981
Passive Intake System for Shallow
Sand-Bed River
Date"
1985
1982
1996
1978
1995
1996
1996
1996
1980
1979
1978
1981
1988
Impingement Data
Data
Pre-
sent?
No
No
No
Yes
No
No
No
No
Yes
No
Yes
Yes
No
Used?
No
No
No
No
No
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No mortality data, only passage survival data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
No impingement mortality data
-------
^
o
ID
DCN
EPA-HQ-OW-
2008-0667-
2391
EPA-HQ-OW-
2008-0667-
2391
DCN 11 -5473
DCN 11 -5498
DCN 11 -5497
DCN 11 -5493
DCN 11 -5494
DCN 11 -5459
Authors
Kinetrics
Mayer, Christine
Serven, J. T. and
Barbour, M. T.
Ecological Analysts,
Inc.
Ecological Analysts,
Inc.
EA Science and
Technology
Ecological Analysts,
Inc.
Ecological Analysts,
Inc.
Title
Bay Shore Power Plant Cooling
Water Intake Structure Information
and I&E Sampling Data
Effects of Bayshore Power Plant on
Ecosystem Function in Maumee
Bay, Western Lake Erie, Annual
Progress Report to NOAA
C. P. Crane Power Plant:
Impingement Abundance and
Viability Studies Final Report
January - December 1980
Danskammer Point Generating
Station Impingement and
Entrainment Survival Studies, 1975
Annual Report
Danskammer Point Generating
Station Impingement Survival
Studies 1976 Annual Report
Estimates of Impingement Mortality
for Selected Fish Species at the
Roseton Generating Station 1 975-
1977
Roseton Generating Station
Impingement and Entrainment
Survival Studies 1975 Annual
Report
Roseton Generating Station: Near-
Field Effects of Once-Through
Cooling System Operation on
Hudson River Biota
Date"
2008
2011
1981
1976
1977
1985
1976
1977
Impingement Data
Data
Pre-
sent?
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Used?
No
No
No
No
No
No
No
No
Reasons for Use/Non-Use
Does not evaluate BTA technology
No impingement data
Technologies not fully documented to verify use of BTA.
Does not evaluate BTA technology.
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
Does not evaluate BTA technology
* Some of the impingement or entrainment data reported in this document (counts and/or mortality percentages) were entered in EPA's performance study database and were
summarized within a meta-analysis.
a Unknown (not specified)
"Data Present?" = Yes if impingement data appear in the document.
"Used?" = Yes if the data were used by EPA to establish the impingement mortality standard.
-------
§ 316(b) Existing Facilities Final Rule-TDD Chapter 11: Appendix B
Appendix B to Chapter 11: "Non-Fragile" Species
The table in this appendix provides information about the organisms evaluated for
Chapter 11.
Exhibit 11B-1 identifies the species of organisms that are not considered "fragile" and
were included in the data used to develop the impingement mortality limitation.
11B-1
-------
Chapter 11: Appendix B
§ 316(b) Existing Facilities Final Rule-TDD
Exhibit 11B-1. Fish Species Classified as "Non-Fragile" in Data Selected as the Basis of
the Impingement Mortality Limitation
american eel
american lobster
american sand lance
atlantic cod
atlantic croaker
atlantic silverside
atlantic tomcod
banded killifish
black crappie
black sea bass
blackcheek tonguefish
blackspotted stickleback
blue crab
bluegill
bluntnose minnow
brook silverside
brown bullhead
brown shrimp
buffalos
bullhead minnow
callinectes spp. (common/lesser)
carp
catostomidae
channel catfish
chub mackerel
codfish
conger eel
croaker
crystal darter
cunner
cyprinidae (carps)
darters
emerald shiner
fathead minnow
flathead carfish
flounder
fourbeard rockling
fourspine stickleback
freshwater drum
golden redhorse
golden shiners
goldeye
goldfish
goosefish
green crab
grubby
hardback shrimp
hogchoker
johnny darter
lady crab
largemouth bass
lepomis spp.
log perch
longnose dace
lookdown
lumpfish
mottled sculpin
mud crab
mud darter
mummichog
naked goby
northern pipefish
northern puffer
northern searobin
orange filefish
orangespotted sunfish
oyster toadfish
pagarus longicarpus
pagurus pollicaris
pea crab
penaeid shrimp
penaeus
penaeus spp. (pink and white)
percidae (perches)
plains minnow
planehead filefish
pollock
pomoxis
pumpkinseed
quilback sucker
rainbow trout
red hake
red shiner
redhorse sucker
river darter
river shiner
rock bass
rock crab
rock gunnel
rough scad
round goby
sand lance
sand shiner
sand shrimp
sauger
sculpin spp.
sea trout
searobin
shorthead redhorse
shrimp
shrimp spp. (pink and white)
silver chub
silver hake
silver perch
silver redhorse
smallmouth bass
smallmouth flounder
spider crab
spot
spotfin shiner
spottail shiner
spotted hake
star drum
stonecat
striped bass
striped cusk-eel
striped mullet
striped searobin
summer flounder
tautog (blackfish)
tesselated darter
three spine stickleback
trout perch
walleye
weakfish
white bass
white catfish
white crappie
white hake
white perch
white sucker
windowpane flounder
winter flounder
yellow perch
11B-2
-------
§ 316(b) Existing Facilities Final Rule - TDD Chapter 12: Analysis of Uncertainty
Chapter 12: Analysis of Uncertainty
12.0 Introduction
Any scientific analysis contains some degree of uncertainty. Data used to develop the
analysis may have inherent flaws, assumptions may not be entirely accurate, or outside
factors may unexpectedly influence the outcome. In many cases, uncertainty can be
reduced by conducting parallel analyses or verifying conclusions via alternate pathways
or data sources. This chapter presents EPA's efforts to identify sources of uncertainty,
evaluate how those uncertainties might affect the analyses, and consequently minimize
the effects of uncertainty associated with its analyses.
12.1 Uncertainty in Technical Analysis of Impingement Mortality
12.1.1 Technology in Place and Related Model Facility Data
The detailed technical questionnaires were conducted more than 10 years prior to this
final rule. Changes may have occurred at individual facilities that would affect the cost
and reductions analyses such as number of intakes, intake flow, operational status, and
current technology in place. (EPA did collect more current financial information to
update and revise the economic analysis; see EA for more information.) Based on site
visits and discussions with industry, EPA believes the technical data is still sufficiently
representative of industry operations and can be used to estimate national level costs and
reductions of various regulatory approaches. However, during the past 10 years some
facilities have installed impingement and entrainment technologies as a result of the
Phase II rule initial implementation, state policies, or other local requirements, and these
may not be accounted for in the database. EPA did attempt to incorporate newly installed
technologies that have or will be installed as a result of state policy requirements for
California and New York. However, requirements imposed in other states during the past
10 years are not accounted for and as a result the costs and reductions of the technologies
considered in the final rule are potentially overstated.
12.1.2 Costs of Additional Impingement Mortality Controls
The economic analysis presented in the EA contains estimated compliance costs for
impingement mortality technologies and, for one final rule option, entrainment mortality
technologies. One uncertainty EPA identified in basing compliance costs on the industry
detailed technical questionnaire is how many facilities already use modified traveling
screens, other technologies, or a system of technologies that are compliant or nearly-
compliant with the impingement mortality standard. Similar to 12.1.1, EPA expects
facilities that have installed additional technologies will have lower compliance costs
than those estimated by EPA.
Another uncertainty EPA identified is whether the intake velocities reported in the
technical survey are representative of the actual measured velocity at the screen face that
12-1
-------
Chapter 12: Analysis of Uncertainty § 316(b) Existing Facilities Final Rule - TDD
will determine compliance with the velocity standard. EPA expects that where facilities
inaccurately or inadvertently measured velocity at a different location would provide a
velocity that is slightly lower than the screen face. Where the velocity is sufficiently close
to 0.5 fps, EPA expects variable speed drives provide a low cost method to reduce flow,
and thus velocity (see Chapter 8). Thus such facilities will be able to use either the 0.5 fps
compliance alternative or the system of technologies alternative.
Fish Handling and Return System Costs
The final rule requires that all facilities meet one of seven compliance alternatives that
perform comparably or better than the 12 month impingement mortality standard
calculated from modified traveling screens with a fish return and handling system.
Facilities choosing modified traveling screens or a system of technologies that includes
traveling screens incur costs to install new fish handling and return systems assuming all
of these facilities employed existing traveling screen. EPA finds this to be a reasonable
assumption given the predominance of unmodified traveling screen use; see Chapter 4 for
more information.
However, EPA does not have current data on the number of traveling screens that would
be deemed "modified" screens, such as Ristroph screens or post-Fletcher modifications.
For example, EPA does not have data on the number of large power plants that have
already modified their intakes as a result of the 2004 Phase II rule. As a result of this
uncertainty, EPA conducted a sensitivity analysis on total costs by revising estimated
costs to include fish handling and return systems (as well as new modified Ristroph
screens192) to all facilities employing conventional traveling screens that were deemed to
have met the 0.5 fps threshold.193 In other words, EPA assumed zero facilities have
modified screens with a fish return. Under this conservative assumption, EPA estimates
the manufacturing sector as a whole would be assigned an additional $12.3 million and
electric generators as a whole would be assigned an additional $50.7 million. Therefore,
EPA estimates the total rule costs with the revised assumption that no facility has a
modified traveling screen in place would be approximately 13 percent higher. Based on
site visits and performance studies showing some facilities do in fact have a fish handling
and return, EPA concludes the final rule approach is a more reasonable cost estimate.
Facilities that have modified screens but do not have a fish return system would incur
considerably less costs, and facilities that already have a fish return would incur no
incremental costs as a result of this requirement. This is further likely a conservative
estimate of costs because the rule does not preclude the use of different technologies to
meet the requirements; for example, dual-flow screens and WIP screens would meet the
rule definition of "modified traveling screens." Where these technologies are feasible,
vendor data and pilot studies suggest such technologies are less costly than a retrofit of
existing traveling screens; however, these types of screens are not included in the cost
methodology. See Chapter 6 for more information.
192Technology module 1 was assigned; it includes both the screen replacement costs and costs for a new
fish handling and return system.
193
No additional costs would be assigned to facilities that met the velocity threshold with: modified
Ristroph screens, an offshore intake location (velocity cap or wedgewire), perforated pipe, filter bed, or
porous dike.
12-2
-------
§ 316(b) Existing Facilities Final Rule - TDD Chapter 12: Analysis of Uncertainty
Capital Costs Influence on Annualized Costs
For those technologies with a 20 year lifespan, the annualized costs for any capital
investment (or one time up-front cost) reflect 9.3 percent of the costs (at 7 percent
interest) to 10.8 percent (at 9 percent interest). In other words, a 10 percent increase in
the total capital costs of a compliance technology will result in a 1 percent increase in
annualized costs. Many of the compliance technologies have a useful life greater than 20
years, or would require repair and upgrade versus total replacement. In these cases,
EPA's costs are likely overstated. EPA's costs include a 10 percent contingency factor
for the fish handling and return, and a 20 percent combined total cost contingency factor.
Therefore the total annual costs are not heavily influenced by the uncertainty in the
capital costs for compliance technology. See Section 12.4 for further discussion of annual
cost components such as monitoring and reporting.
12.1.3 Cost Drivers for Impingement Mortality Controls
As part of its review of the compliance costs for impingement mortality, EPA also
examined the cost drivers for impingement mortality. EPA identified several aspects of
the cost methodology that are highly sensitive to variations in frequency of employment
and/or their installation costs. None of the identified factors would have a significant
impact on compliance costs, therefore EPA did not update the cost model further. See
DCN 12-6652 for additional information.
12.1.4 Analysis of a "De Minimis" Provision
EPA has included a provision in the final rule that permits the Director to conclude that a
site-specific determination of BTA for impingement mortality is warranted at sites with
exceptionally low rates of impingement. While EPA has not included this provision in its
final estimate for compliance costs, EPA did conduct a brief analysis to examine the cost
implications of such a provision.
EPA intends that this provision would not be utilized often. EPA randomly selected 5
percent of the model facilities. This subset of facilities represents the facilities that either
impinge an exceptionally low number of organisms or are located on a waterbody that
has exceptionally low levels of impingeable organisms. With an even distribution of
facilities, EPA would expect this provision would result in lower total rule compliance
costs of approximately 5 percent. Because these same facilities have exceptionally low
rates of impingement, this provision would have minimal effect on the estimated
reductions in IE resulting from the rule requirements. This random method of
classification is independent of operational and technological characteristics of the
facility; as a result, some of the facilities identified as "compliant" under this hypothetical
scenario were already compliant using some other compliance mechanism (e.g., intake
velocity below, 0.5 fps, closed-cycle cooling, etc.). Exhibit 12-1 illustrates the breakdown
of facilities.
12-3
-------
Chapter 12: Analysis of Uncertainty
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 12-1. Compliance Assessment of Randomly Selected De Minimis Intakes
Generators
Manufacturers
Total
Number De minimis
Intakes
21
18
39
Number De minimis
Intakes IM Non-
Compliant
11
8
19
Number De minimis
Intakes IM Compliant
10
10
20
As seen in the table, in the random sample analyzed, approximately half of the facilities
selected as compliant under a de minimis scenario were already compliant under a
different compliance alternative. This analysis serves to suggest that EPA's cost estimates
for impingement mortality is likely overstated by 2 to 5 percent as some facilities may
achieve compliance under the de minimis provision.
12.2 Uncertainty In Technical Analysis of Entralnment Mortality
12.2.1 Intake Location
The ability of a facility to locate an intake structure to significantly reduce entrainment,
and to a lesser extent impingement, depends on waterbody and species found at that site.
Of particular interest is the relationship of ichthyoplankton density to water depth as a
potential technology for reducing impingement and entrainment mortality. EPA used a
Southeast Area Monitoring and Assessment Program (SEAMAP) database to
characterize ichthyoplankton (fish eggs and larvae) presence, composition, and density
within the Gulf (see DCN 9-5200; FDMS ID EPA-HQ-OW-2004-0002-1956). A plot of
average ichthyoplankton densities against depth at 10 meter intervals (see Exhibit 12-2
below) shows general trends were similar between egg and larval fish densities. The
densities of both declined most rapidly from 0 to 60 meters in depth. As depth increased
past 60 meters, the decline in ichthyoplankton and egg densities was less pronounced.
This is consistent with the understanding that the euphotic zone (zone light available for
photosynthesis) does not extend beyond the first 100 meters (328 feet) of depth.
12-4
-------
§ 316(b) Existing Facilities Final Rule - TDD
Chapter 12: Analysis of Uncertainty
Exhibit 12-2. Average Densities (N/m3) of eggs and ichthyoplankton
sampled at a given maximum depth intervals in the Gulf of Mexico
-*.-- Ichthyoplankton Density
-«—Egg Density
85555555555,633333'*'
00 O ^CNCJ^iOfflr^-Q.! Oi O *~ CN rt ^
Maximum Sampling Depth (m)
The findings of the SEAMAP analysis for the Gulf of Mexico are generally supported by
the cited papers from the Pacific and British coasts and the data from the Gulf of Maine,
i.e., that ichthyoplankton densities increase as depth and distance from shore decrease,
and that abundance is greatest at depths less than 100 meters. These data did not show
consistent I and E reductions, or in many cases did not result in a high level of EVI and E
performance as a result of intake location. Further, as a result of these analyses, EPA has
determined only intakes far offshore in the ocean or Great Lakes could achieve such
distances and depths, therefore the technology is not available for most facilities. Other
facility data shows that substantial decreases in density are not observed even far
offshore. Therefore, EPA did not further consider intake location as a high performing
technology and thus did not consider location as a candidate technology for national
standards. This analysis supports EPA's decision to consider existing offshore velocity
caps at least 800 feet offshore; the performance data for these existing facilities shows
equal or better performance than the BTA EVI performance standard. This analysis also
supports EPA's decision to require newly installed velocity caps to demonstrate the
velocity cap in combination with the intake location meets or exceeds the BTA EVI
performance standard. EPA anticipates for some facilities, an intermediate
distance/depth/density where an order of magnitude decrease in density would occur, and
allows for such a site-specific demonstration under the "systems of technologies"
compliance alternative.
12-5
-------
Chapter 12: Analysis of Uncertainty § 316(b) Existing Facilities Final Rule - TDD
12.2.2 Space Constraints
Chapter 10 discusses EPA's approach to estimating the number of facilities that would
face space constraints (as well as constraints for noise and tower plume). At some facility
sites, EPA believes retrofitting to closed-cycle cooling is extremely difficult or perhaps
infeasible due to a lack of space for the cooling tower. Space constraints, in particular
water-front acres, may preclude expanding an existing intake structure such as to reduce
intake velocity by adding intake bays or due to fine mesh installations. In the majority of
cases, EPA found dense urban locations simply have no space available on the site to
locate a cooling tower of sufficient size. In many cases, the surrounding land is occupied,
making it impossible (or prohibitively expensive) to acquire additional land. EPA did not
assess the costs of additional land purchases in its analysis, because EPA does not have
adequate data on which to predict the number of facilities with space constraints, their
locations, and the availability and costs of neighboring land.
Based on site visits, permits, and other reports, EPA assumed an upper bound of one in
four, or 25 percent, of facilities would face space constraints. EPA based this assumption
on the observation that approximately 95 percent of the 47 known sites with a ratio of
160 acres per 1000 megawatt (MW) and above would have sufficient acreage to retrofit
mechanical draft cooling towers. For the 25 observed sites with a ratio less than 160 acres
per 1000 MW, as many as 20 percent of the facilities would likely be space constrained.
Another GIS-based approach EPA conducted (instead of the population density method
presented in Chapter 10) was to use a data layer from the National Atlas that identified
"urban" areas. Similar to the population density approach, this data layer would identify
areas that are likely to have high densities of populated space and would be the most
likely to face significant challenges in siting a retrofit cooling tower.
The urban GIS layer identified a similar profile for land availability. For example, it
identified approximately 30 percent of facilities as located in an urban area (as examined
by the number of facilities, percentage of total flow, and percentage of total cost).194
Electric generators were identified as urban slightly less often and manufacturers were
identified slightly more often. Small businesses were much less likely to be identified as
urban.
The primary drawback of this data was that it was not clear how the urban identification
had been designated. Given the similarities in the two approaches and their projected
outcomes, EPA opted to use the population density approach, as it provides a better
defined and more reliable algorithm.
EPRI reported at least 6 percent of sites (7 out of the 125 evaluated) were deemed
"infeasible" on the basis that no space was available on which to locate a cooling tower
(see DCN 10-6951, EPRI Technical Report 1023452). The 125 sites are not statistically
representative, and it is impossible to ascertain any skew that may be present in the
evaluated sites (for example, whether smaller sites or rural sites are overrepresented).
194
EPA also examined the universe of facilities by waterbody type, state, cooling system type, capacity
utilization, fuel type, and manufacturing sector. In each case, there were no significant trends that would
affect the broader assumption that approximately 30 percent of facilities are in an urban location.
12-6
-------
§ 316(b) Existing Facilities Final Rule - TDD Chapter 12: Analysis of Uncertainty
Further, EPA does not have access to the facility level data, and is therefore unable to
conduct further analysis of the 125 sites. Nevertheless, EPRI's report supports EPA's
assertion that some sites have space constraints, and that there is significant uncertainty
around the frequency with which space constraints for facilities would preclude installing
or retrofit to closed-cycle cooling.
12.2.3 Development of Cooling Tower Costs
In the Phase I and 2004 Phase II rules, EPA used a cost estimation approach that it
developed to calculate estimated costs for closed-cycle cooling. This approach was
derived from cost modules that specify the necessary activities, materials, and
contingencies that comprise the total cost.
In 2007, EPRI provided a new cost estimation tool to EPA. The EPRI tool calculated
costs based on documentation for over 50 closed-cycle retrofits and/or detailed feasibility
studies. EPA also used cooling tower engineering assessments conducted for California
as part of the Policy on the Use of Coastal and Estuarine Waters for Power Plant Cooling.
These detailed assessments were conducted on 19 existing coastal plants. Maulbetsch and
others have documented cooling tower assessments and presented such findings in
symposiums and proceedings; for example see "Issues Associated with Retrofitting
Coastal Power Plants" (DCN 10-6955) and "Water Conserving Cooling Status and
Needs" Energy-Water Needs" (DCN 10-6953).
Exhibit 12-3 provides a comparison of the cooling tower compliance costs derived using
the EPRI Tower Calculation Worksheet to compliance costs derived using the EPA
Methodology used in 2004 Phase II for an option where cooling towers were retrofitted to
facilities on estuaries and oceans. For purposes of this sensitivity analysis, the costs
shown are for a 350 MW facility with a cooling water flow of 200,000 gallons per minute
(gpm) (288 million gallons per day [mgd]). The 2004 EPA costs are adjusted to 2009
dollars. It is assumed that the costs shown contain comparable structural components
although it is not known whether the EPRI costs include condenser upgrades so this
element of the 2004 EPA costs is shown separately (not all cooling tower retrofits require
condenser upgrades therefore EPA's costs would not apply condenser upgrade costs to all
facilities). The 2004 EPA costs shown do not include any intake modification costs. EPA
operations and maintenance (O&M) costs are for gross O&M meaning they do not
include reductions for baseline technology O&M such as once through pumping energy
costs. Therefore EPA's O&M are potentially overstated.
Exhibit 12-3 shows that the two costing methodologies produce similar results. While the
2004 EPA non-nuclear and nuclear facility capital costs are comparable to the EPRI
"easy" and "average" costs, the EPA's O&M cost are higher for nuclear facilities. The
highest and lowest total annualized costs (based on 20-year service life and discount rate
of 5 percent) cover a similar span for both methodologies especially if condenser
upgrades are included. Thus, use of either method should produce comparable national
costs.
12-7
-------
Chapter 12: Analysis of Uncertainty
§ 316(b) Existing Facilities Final Rule - TDD
Exhibit 12-3. Cost Comparison for a 350 MW Plant with Cooling Flow of 200,000
gpm (288 MGD)
EPA
Phase
II
EPRI
Costs
Tower
Type
Redwood
Tower
Redwood
Tower -
Nuclear
Easy
Average
Difficult
Capital Costs -
Tower and
Piping
$27,000,000
$49,000,000
$32,000,000
$53,000,000
$83,000,000
Condenser
Upgrade1
$5,200,000
$9,400,000
-
-
-
O&M
Included in
O&M Total
Included in
O&M Total
$260,000
$260,000
$260,000
Tower
Electricity
Usage
(Pumps &
Fans)
Included in
O&M Total
Included in
O&M Total
$2,600,000
$2,600,000
$2,600,000
O&M Total2
$2,900,000
$4,200,000
$2,860,000
$2,860,000
$2,860,000
Annualized
Capital Not
Including
Condenser
Upgrade
$2,200,000
$3,900,000
$2,600,000
$4,200,000
$6,600,000
Annualized
Condenser
Upgrade
$400,000
$800,000
-
-
-
Total
Annualized
Cost Not
Including
Condenser
Uosrade
$5,100,000
$8,100,000
$5,460,000
$7,060,000
$9,460,000
Annual
Heat Rate
Penalty4
7
7
$1,040,000
$1,040,000
$1,040,000
EPA did not include full condenser upgrade costs at all facilities. Not sure If EPRI included them
O&M shown does not include deduction for baseline O&M pumping energy
3 Annualized Capital Cost Factor (20 yr at 5%) = 0.08
Heat rate penalty not included in O&M total or Total Annualized Cost
The advantages of using the EPRI costing approach include:
• It can produce a range of capital costs (i.e., the ability to use easy, average and
difficult settings);
• The underlying data is based on actual retrofits, and is likely a more robust
representation of costs;
• The EPRI worksheet can be readily modified to generate facility costs while the
EPA method is more complex and would require considerable spreadsheet
development;
• Input variables can be readily generated; and
• The methodology generates all costs including the energy penalty costs.
12.3 Uncertainty in Benefits ofl&E Controls
12.3.1 Reductions in Impingement and Entrainment by Region
EPA's analysis of reductions used data from studies across several EPA Benefits Regions
(see the BA for further information). There are four major kinds of uncertainty that may
lead to imprecision and bias in EPA's I&E mortality analysis: data, structural, statistical,
and engineering uncertainty. These are discussed in detail in Section 1.1 of the BA. In
response to these potential limitations, EPA conducted a sensitivity analysis exploring the
extent to which baseline impingement and entrainment (I&E), and therefore the
corresponding potential reductions in I&E attributable to installation of compliance
technology, changes as a result of combining or isolating studies in the various benefits
regions. The studies I and E losses on a per unit flow (mgd) basis are presented in terms
of Age-1 Equivalents in Exhibit 12-4. The sensitivity analysis is based on the regions,
studies, and methodology used for the proposal.
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 12: Analysis of Uncertainty
Exhibit 12-4. Impingement and Entrainment Losses Per Unit Flow
Region
(Freshwater Regions)
Inland (all)
Great Lakes
subtotal
(Marine Regions)
California Coastal
Mid-Atlantic
North Atlantic
Gulf of Mexico
South Atlantic
subtotal
Total for all regions3
Studies
44
11
55
18
12
6
3
2
41
96
AIF
139,178
19,047
158,225
12,300
28,165
7,037
13,246
7,462
68,210
226,435
Average
Study I
losses in
AlEper
MGD
4,457
2,489
4,063
514
4,532
113
8,073
7,064
2,504
4,249
Average
Study E
losses in
AlEper
MGD
1,924
569
1,653
23,242
33,697
11,919
9,722
735
22,558
7,648
a Average Study I losses in A1E per mgd for all regions are flow weighted.
It appears impingement dominates the total A1E in freshwater systems, and entrainment
dominates the marine regions. Due to the limited number of studies in certain regions,
EPA next combined studies in those regions and recalculated the national baseline I&E.
Due to most studies being conducted on waterbodies in the inland region, EPA also
combined all studies by salinity, i.e., a freshwater region and a marine region. Finally,
EPA combined all studies into one national region. In each case, the weight of the study
(based on the actual flows reported in each study) was kept the same. In all scenarios,
EPA found the change in baseline I&E increased as shown Exhibit 12-5.
Exhibit 12-5. Changes in Baseline Impingement and Entrainment
Method of combining studies
without changing the weight of each
study
7 regions (current approach)
5 regions: CA, MA, INL, GL, GoM
2 regions, AIF wtd avg
all regions total value
2 regions, freshwater and marine,
study average
6 regions (GoM and SA combined)
5 regions (GoM + SA, NA+MA
combined)
National
baseline 1
(A1E)
9.49E+08
1.01E+09
8.56E+08
1.01E+09
8.56E+08
9.56E+08
1.00E+09
National
baseline E
(A1E)
1.52E+09
2.21 E+09
1.86E+09
1.82E+09
1.86E+09
1.58E+09
1.80E+09
National
baseline I&E
combined
(A1E)
2.47E+09
3.23E+09
2.71 E+09
2.83E+09
2.72E+09
2.54E+09
2.81 E+09
% change in
national
baseline over
current
approach
—
+31%
+ 10%
+ 15%
+ 10%
+3%
+ 14%
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Chapter 12: Analysis of Uncertainty § 316(b) Existing Facilities Final Rule - TDD
This uncertainty analysis suggests potential bias is accentuated when combining studies
from different waterbodies. In particular, the extremely small number of studies in the
Gulf of Mexico and the South Atlantic regions, and the significantly lower I&E attributed
to those regions, is highlighted. Studies in other waterbodies show higher I&E baseline
estimates, suggesting the national baseline could be as much as one-third higher than the
currently used approach to regional benefits analysis. Further, there is considerable
variability observed in I, E, and I&E combined (as measured in A1E).
To reduce this uncertainty, EPA collected additional studies in all regions, solicited data
in the proposed rule, and considered revising the baseline I&E calculations. EPA did
receive additional studies, but found that the studies reported baseline I&E rates
consistent with the averages EPA already reported in the proposed rule. As EPA already
found the costs justify the benefits of the final rule, EPA determined no revision to the
national baseline approach was warranted. However, based on this sensitivity analysis the
I and E reductions of the final rule are most likely an underestimate because EPA is using
the most conservative grouping of studies out of the seven approaches identified.
12.3.2 Air Emissions Associated with Closed-Cycle
Fossil-fueled facilities may need to burn additional fuel (thereby emitting additional CC>2,
SC>2, NOx, and Hg) for two reasons: 1) to compensate for energy required to operate
cooling towers, and 2) slightly lower generating efficiency attributed to higher turbine
back pressure. In general, EPA expects national level emissions may increase in the short
term, 95 but decrease over the long term as facilities upgrade the oldest units by replacing
condensers and boilers. U.S. fleet efficiency will likely increase over the long term,
resulting in lower base emissions on a per watt basis, and the turbine back pressure
penalty will be further reduced resulting in lower incremental emissions.
EPA's projected emissions due to cooling tower energy penalties include several sources
of uncertainty. EPA's economic analysis of a cooling towers based rule indicates that
some units and a few facilities may close as a result of the rule. The IPM modeling used
in EPA's economic analysis indicates any closures of generating units are generally
comprised of the oldest and least efficient (and therefore the highest emitting) units,
resulting in a potential reduction in total air emissions as a result of these closures; see the
EA for more information on this specific assessment. Additional capacity brought online
to replace these facility closures will be more efficient units. In addition, the current
emissions rate calculations do not reflect full implementation of the most recent air rules.
For example, the 2005 Clean Air Interstate Rule (CAIR) will reduce 2003 NOx level by 53
percent in 2009 and 61 percent in 2015. Similarly, 2003 SOX levels would be reduced by
45 percent in 2010 and 57 percent in 2015. The Utility Maximum Achievable Control
Technology mercury rule would require utilities to install controls to reduce mercury
emissions by 91 percent. Since the actual emissions data used in EPA's analysis does not
reflect full implementation of these air rules, and since in some cases technologies to
195 In its comments on the Phase II rule (see DCN 6-5049, authors 316bEFR.211 and 316bEFR.214), the
Department of Energy (DOE) predicts energy penalties ranging from 2.4 to 4.0 percent for conversion to
wet cooling towers by Phase II facilities, i.e., electric generators with a DIP of greater than 50 mgd. DOE
applied these penalties to case study regions and projected less than 1 percent emissions increases.
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 12: Analysis of Uncertainty
reduce emissions have yet to be installed, both the baseline and any potential increase in
emissions are overstated. Finally, the latest tower fill materials and other cooling tower
technology improvements provide increases in cooling capacity. In some cases cooling
towers provide cooling water at lower temperatures than available from the source water,
resulting in lower turbine back pressure in the summer when maximum power generation is
desired.
EPA's emissions estimates also include emissions (drift) from the cooling towers
themselves. Drift consists of water droplets exiting the cooling tower. Drift can result in
formation of particulate matter (primarily PMio) when the droplets evaporate before hitting
the ground. Current cooling tower designs minimize drift to less than 0.1 percent of the
circulation flow. Sustained winds and high humidity must be present for drift to reach
distances of several hundred feet, therefore most power plants will not have any adverse
impacts due to drift. The options considered include costs for drift eliminators - additional
technology installed on the top of the cooling tower to further reduce drift to 0.0005 percent
of the circulating flow. EPA has reviewed non-attainment areas for PMio and has found
many power plants in these areas are using dry cooling, which avoids any issues with drift.
Exhibit 12-6. Map of Non-Attainment Areas for PMIO
A
Legend
• Plant_Locations
I PM10_Nonattainment_counties Source. U.S. EPA Office of Air and Radiation, AQS Database.
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Chapter 12: Analysis of Uncertainty § 316(b) Existing Facilities Final Rule - TDD
Chapter 10 discusses the methodology to estimate incremental increases in such air
pollutant emissions from retrofitting cooling towers. The approach used a generic
modeling of particulate matter emissions from the cooling towers, but more site-specific
analyses often use air quality modeling method AP-42. For example, Chapter 8 of EPA's
"Emission Estimation Protocol for Petroleum Refineries" specifies ranked approaches to
estimating losses from cooling towers. Methodology Rank 5 for cooling towers uses the
total liquid drift emission factor given in AP-42 (U.S. EPA, 1995) of 1.7 Ib of drift per
1,000 gallons of water (lb/103 gal) for induced draft cooling towers and the total
dissolved solids (TDS) weight fraction to estimate PM-10 emissions. This is a
conservative PM-10 emission factor in that it assumes that all TDS are in the PM-10 size
range. Peer review of EPA's Office of Air Quality has further identified the method AP-
42 frequently overestimates emissions.196 The site-specific TDS fraction in the cooling
water should be used when available, the site-specific TDS fraction can be estimated
from the TDS of the makeup water and the cycles of concentration ratio (ratio of the
measured parameter for the cooling tower water such as conductivity, calcium, chlorides,
or phosphate, to the measured parameter for the makeup water), when these data are
available. The following two examples of PM-10 emissions estimates calculations (DCN
10-6905) provide an additional method by which EPA can quantify an upper bound of
PM emissions from cooling towers (see Exhibit 12-7 below).
In addition to the uncertainty over annual baseline emissions generated and the
uncertainty over incremental increases in emissions, there is uncertainty over the
environmental impacts of emissions. Four of the 15 largest users of cooling water obtain
cooling water from a freshwater source; more than half of all existing facilities withdraw
water from an inland fresh water river, stream, or lake. The potential for drift formation is
highest where cooling water withdrawals are obtained from a saltwater environment.
Further, sustained winds and high humidity must be present for drift to reach distances of
several hundred feet. A review of EPA's technical questionnaires shows that 10 of the 15
largest users of cooling water (representing more than 12 percent of the total national
potential withdraws) are nuclear facilities. Nuclear facilities tend to have setbacks,
security perimeters, and other boundaries that are significantly distant from the
generating facility that drift is unlikely to land beyond the facility property lines.
However, due to the uncertainty of these site-specific factors, EPA is unable to conclude
that drift will not result in an environmental impact.
196 See DCN 10-6905.
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§ 316(b) Existing Facilities Final Rule - TDD
Chapter 12: Analysis of Uncertainty
Exhibit 12-7. Examples of PM-10 Emissions Estimates Calculations
Example 8-6: Calculation for Methodology Rank 5 for Cooling Towers
Given: For PM-10 emissions from a cooling tower with a water recirculation rate of 25,000 gal/min, that
is servicing a heat exchanger cooling a gasoline stream, and that is in service all year. Using the
default average TDS weight fraction of 0.0206 (or 20,600 ppmw), the following equation should be
used to calculate the annual emissions of PM-10, EPM10:
'"M1° " 10s gal "' Jb drift'" nil hr °" yr 2000 Ib ~~ ' yr
Example 8-7: Calculation for Annual Emissions from Cooling Towers
Given: For PM-10 emissions from a cooling tower with a water recirculation rate of 25,000 gal/min and
that is sampled monthly for TDS. Using the site-specific TDS fraction and the operating hours between
measurements, equation (Eq. 8-9) should be used to calculate the annual emissions of PM-10, EPMW.
Date
Jan 10 (startup Jan 1)
February 4
March 4
April 4
May 4
June 4
July 4
August 4
September 4
October 4
November 4
December (shutdown Dec
1 - not operating in
December)
Total
TDS Concentration
(ppmw)
360
520
780
1,100
1,260
2,300
3,500
5,500
4,600
1,700
2,100
(2,100- Use value
from previous month)
Hours
96
600
672
720
720
744
720
744
744
720
744
(648)
7,872
Emissions
(ton/month)
0.044
0.398
0.668
1.01
1.16
2.18
3.21
5.22
4.36
1.56
1.99
1.73
24 ton/yr
Source: DON 10-6905
12.4 Uncertainty in Model Facility Approach
Accompanying the detailed questionnaire data is a survey weight, a value that has been
updated since the original survey to continue to reflect national level facility counts.
Accordingly, the weights are not necessarily reflective (statistically) where subsets of the
facilities less than the national level are used. EPA has updated the model facility
weighting factors based on known unit and facility closures (see EA for more information
on weighting factors). For example, if the total in-scope universe of affected facilities
decreased from 1292 facilities down to 1265 facilities, the weighting factors changed by
less than 1 percent. EPA notes this new weighting factor has no effect on individual
facility costs or impacts, it merely adjusts (reduces slightly) the total national rule costs
and total national rule benefits. Further, the facility weights for power plants are
sufficiently close to a value of 1.0 that any variations in weight are expected to have a
minimal impact on any analysis. In the case of manufacturing facilities, weights
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Chapter 12: Analysis of Uncertainty § 316(b) Existing Facilities Final Rule - TDD
calculated for a given facility may be as high as 4, but are usually less than 2. As EPA's
model facility approach is applied over such a large universe (several hundred model
facilities), EPA again expects a minimal effect on any national level analysis. For
transparency, this TDD identifies where facility counts and other related technical data
based on the survey are provided as unweighted or weighted values.
12.5 References
Electric Power Research Institute (EPRI). 2007. Fish Protection at Cooling Water
Intakes: A Technical Reference Manual.
U.S. EPA (Environmental Protection Agency). 1995. Compilation of Air Pollutant
Emission Factors. Volume 1: Stationary Point and Area Sources. AP-42, Fifth
Edition. Office of Air Quality Planning and Standards, Research Triangle Park,
NC.
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