Final Programmatic Environmental Impact
Statement
USMCA Mitigation of Contaminated Transboundary
Flows Project
November 2, 2022
Lead Agencies:
&EPA
U.S. Environmental Protection Agency
Office of Wastewater Management
1200 Pennsylvania Avenue, NW
Washington DC 20460
International Boundary and Water Commission
United States Section
4191 N Mesa Street
El Paso TX 79902
Abstract:
The U.S. Environmental Protection Agency and the U.S. International Boundary and Water Commission, as
joint lead agencies, are proposing to fund and implement the United States-Mexico-Canada Agreement
Mitigation of Contaminated Transboundary Flows Project (the Proposed Action) to reduce transboundary
flows from Tijuana that cause adverse public health and environmental impacts in the Tijuana River
watershed and adjacent coastal areas. This Final Programmatic Environmental Impact Statement (PEIS] sets
forth a tiered framework for future funding decisions and reviews the environmental impacts of the
Proposed Action, which is located in San Diego County, California and Tijuana, Mexico. The Final PEIS
includes two alternatives to address the purpose and need—a limited funding approach for implementing the
Proposed Action and a more comprehensive solution for implementing the Proposed Action—and a third
alternative of no disbursement of funding and continuation of current wastewater management practices.
The comprehensive solution is the preferred alternative. The public and any interested party are invited to
review and comment on this Final PEIS before issuance of the Record of Decision, which would identify the
decision on the Proposed Action by selecting an alternative for implementation.
Further Information:
Steven Smith
75 Hawthorne Street
San Francisco CA 94105
415-972-3752
Prepared by:
Eastern Research Group, Inc. (ERG)
Subcontractors to ERG:
ASM Affiliates
PG Environmental
Stillwater Sciences
Tenera Environmental
Estimated Total Cost to
Prepare Draft PEIS and
Final PEIS (EPA, USIBWC,
contractor, and
subcontractor costs):
$1,990,000
Work Performed Under EPA Contract No. 68HERH19D0033
Task Order No. 53
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Contents
CONTENTS
Contents i
List of Tables viii
List of Figures xii
Abbreviations, Acronyms, and Symbols xvi
Executive Summary xxi
1. INTRODUCTION 1-1
1.1 Background 1-1
1.2 Existing Diversion and Treatment Infrastructure 1-5
1.3 Causes and Impacts of Contaminated Transboundary Flows from Tijuana 1-12
1.3.1 Causes of Contaminated Transboundary Flows 1-12
1.3.2 Impacts of Contaminated Transboundary Flows 1-15
1.4 Purpose and Need for Action 1-17
1.5 Purpose and Scope of the Programmatic EIS 1-18
2. DESCRIPTION OF ALTERNATIVES CONSIDERED 2-1
2.1 Formulation of Alternatives 2-1
2.1.1 Identification of Projects to Undergo Feasibility Analysis 2-1
2.1.2 Project Feasibility Analysis 2-2
2.1.3 Alternatives Analysis 2-3
2.2 Proposed Action and Range of Alternatives Evaluated in This PEIS 2-3
2.3 No-Action Alternative 2-5
2.4 Alternative 1: Core Projects 2-6
2.4.1 Projects A, B, and C: Improve Collection and Treatment of
Wastewater 2-6
2.4.1.1 Project A: Expanded ITP 2-6
2.4.1.2 ProjectB: Tijuana Canyon Flows to ITP 2-12
2.4.1.3 Project C: Tijuana Sewer Repairs 2-18
2.4.2 Project D: APTP Phase 1 2-21
2.5 Alternative 2: Core and Supplemental Projects 2-28
2.5.1 Core Projects 2-28
2.5.2 Supplemental Projects 2-28
2.5.2.1 Project E: APTP Phase 2 2-29
2.5.2.2 ProjectF: U.S.-side River Diversion to APTP 2-31
2.5.2.3 Project G: New SABTP 2-33
2.5.2.4 Project H: Tijuana WWTP Treated Effluent Reuse 2-36
2.5.2.5 Project I: ITP Treated Effluent Reuse 2-37
2.5.2.6 Project J: Trash Boom(s) 2-39
2.6 Identification of Preferred Alternative and Environmentally Preferable
Alternative 2-41
2.7 Alternatives Eliminated from Evaluation in This PEIS 2-41
2.7.1 Projects and Sub-projects from EPA's Initial Set of 10 Projects 2-41
2.7.2 Alternatives Other Than the Comprehensive Infrastructure Solution 2-44
2.7.3 Other Projects Identified Based on Public Scoping Comments 2-45
2.7.4 Other Projects Identified Based on Public Comments on the Draft
PEIS 2-47
2.8 Funding Sources and Binational Agreement 2-48
2.9 Related Projects 2-52
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project Contents
(Continued)
3. AFFECTED ENVIRONMENT 3-1
3.1 Freshwater and Estuarine Resources 3-1
3.1.1 Hydrology 3-1
3.1.1.1 Tijuana River in Mexico (Upstream of U.S.-Mexico Border) 3-1
3.1.1.2 Tijuana River in U.S. (Downstream of U.S.-Mexico Border) 3-2
3.1.1.3 Tijuana River Estuary 3-5
3.1.1.4 Tributary Flows in the Tijuana River Valley 3-6
3.1.1.5 Wetlands and Delineated Aquatic Resources 3-6
3.1.2 Surface Water Quality 3-16
3.1.2.1 Sediment 3-17
3.1.2.2 Bacteria 3-18
3.1.2.3 Trash 3-19
3.1.2.4 Other Pollutants 3-19
3.1.3 Stormwater Management 3-20
3.1.4 Groundwater and Drinking Water 3-21
3.1.5 Recreational and Commercial Uses 3-22
3.2 Marine Waters 3-22
3.2.1 Physical Oceanography of Southern California 3-22
3.2.2 Marine Water Quality 3-23
3.2.3 Recreational and Commercial Uses 3-26
3.3 Floodplains 3-26
3.4 Inland Biological Resources 3-31
3.4.1 Botanical Resources 3-31
3.4.2 Wildlife and Inland Fish Resources 3-40
3.5 Marine Biological Resources 3-52
3.6 Geological Resources 3-58
3.6.1 Geology, Soils, and Topography 3-58
3.6.2 Seismic Hazards 3-61
3.7 Cultural Resources 3-64
3.7.1 Summary of Regional Context 3-64
3.7.2 Resources in the Tijuana River Valley 3-65
3.8 Visual Resources 3-67
3.9 Land Use 3-68
3.10 Coastal Zone 3-72
3.11 Air Quality and Odor 3-74
3.12 Climate 3-77
3.13 Solid and Hazardous Waste 3-79
3.14 Energy 3-81
3.15 Public Services and Utilities 3-82
3.16 Public Health and Safety 3-84
3.17 Transportation 3-85
3.18 Noise 3-88
3.19 Socioeconomics 3-92
3.20 Environmental Justice 3-98
4. ENVIRONMENTAL CONSEQUENCES 4-1
4.1 Freshwater and Estuarine Resources 4-2
4.1.1 Standards of Significance 4-2
4.1.2 No-Action Alternative 4-2
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project Contents
(Continued)
4.1.3 Alternative 1: Core Projects 4-2
4.1.4 Alternative 2: Core and Supplemental Projects 4-11
4.1.5 Comparative Analysis of the Alternatives 4-15
4.2 Marine Waters 4-17
4.2.1 Standards of Significance 4-17
4.2.2 No-Action Alternative 4-17
4.2.3 Alternative 1: Core Projects 4-17
4.2.4 Alternative 2: Core and Supplemental Projects 4-29
4.2.5 Comparative Analysis of the Alternatives 4-34
4.3 Floodplains 4-35
4.3.1 Standards of Significance 4-35
4.3.2 No-Action Alternative 4-35
4.3.3 Alternative 1: Core Projects 4-35
4.3.4 Alternative 2: Core and Supplemental Projects 4-35
4.3.5 Comparative Analysis of the Alternatives 4-36
4.4 Inland Biological Resources 4-37
4.4.1 Standards of Significance 4-37
4.4.2 No-Action Alternative 4-37
4.4.3 Alternative 1: Core Projects 4-38
4.4.4 Alternative 2: Core and Supplemental Projects 4-44
4.4.5 Comparative Analysis of the Alternatives 4-47
4.5 Marine Biological Resources 4-49
4.5.1 Standards of Significance 4-49
4.5.2 No-Action Alternative 4-49
4.5.3 Alternative 1: Core Projects 4-49
4.5.4 Alternative 2: Core and Supplemental Projects 4-53
4.5.5 Comparative Analysis of the Alternatives 4-54
4.6 Geological Resources 4-55
4.6.1 Standards of Significance 4-55
4.6.2 No-Action Alternative 4-55
4.6.3 Alternative 1: Core Projects 4-55
4.6.4 Alternative 2: Core and Supplemental Projects 4-57
4.6.5 Comparative Analysis of the Alternatives 4-58
4.7 Cultural Resources 4-59
4.7.1 Standards of Significance 4-59
4.7.2 No-Action Alternative 4-59
4.7.3 Alternative 1: Core Projects 4-59
4.7.4 Alternative 2: Core and Supplemental Projects 4-60
4.7.5 Comparative Analysis of the Alternatives 4-61
4.8 Visual Resources 4-61
4.8.1 Standards of Significance 4-61
4.8.2 No-Action Alternative 4-62
4.8.3 Alternative 1: Core Projects 4-62
4.8.4 Alternative 2: Core and Supplemental Projects 4-63
4.8.5 Comparative Analysis of the Alternatives 4-65
4.9 Land Use 4-67
4.9.1 Standards of Significance 4-67
4.9.2 No-Action Alternative 4-67
4.9.3 Alternative 1: Core Projects 4-67
iii
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project Contents
(Continued)
4.9.4 Alternative 2: Core and Supplemental Projects 4-68
4.9.5 Comparative Analysis of the Alternatives 4-69
4.10 Coastal Zone 4-69
4.10.1 Standards of Significance 4-69
4.10.2 No-Action Alternative 4-69
4.10.3 Alternative 1: Core Projects 4-70
4.10.4 Alternative 2: Core and Supplemental Projects 4-70
4.10.5 Comparative Analysis of the Alternatives 4-70
4.11 Air Quality and Odor 4-71
4.11.1 Standards of Significance 4-71
4.11.2 No-Action Alternative 4-71
4.11.3 Alternative 1: Core Projects 4-71
4.11.4 Alternative 2: Core and Supplemental Projects 4-74
4.11.5 Comparative Analysis of the Alternatives 4-76
4.12 Climate 4-77
4.12.1 Standards of Significance 4-77
4.12.2 No-Action Alternative 4-77
4.12.3 Alternative 1: Core Projects 4-78
4.12.4 Alternative 2: Core and Supplemental Projects 4-78
4.12.5 Comparative Analysis of the Alternatives 4-79
4.13 Solid and Hazardous Waste 4-80
4.13.1 Standards of Significance 4-80
4.13.2 No-Action Alternative 4-80
4.13.3 Alternative 1: Core Projects 4-80
4.13.4 Alternative 2: Core and Supplemental Projects 4-82
4.13.5 Comparative Analysis of the Alternatives 4-83
4.14 Energy 4-84
4.14.1 Standards of Significance 4-84
4.14.2 No-Action Alternative 4-84
4.14.3 Alternative 1: Core Projects 4-84
4.14.4 Alternative 2: Core and Supplemental Projects 4-86
4.14.5 Comparative Analysis of the Alternatives 4-87
4.15 Public Services and Utilities 4-88
4.15.1 Standards of Significance 4-88
4.15.2 No-Action Alternative 4-89
4.15.3 Alternative 1: Core Projects 4-89
4.15.4 Alternative 2: Core and Supplemental Projects 4-90
4.15.5 Comparative Analysis of the Alternatives 4-92
4.16 Public Health and Safety 4-93
4.16.1 Standards of Significance 4-93
4.16.2 No-Action Alternative 4-94
4.16.3 Alternative 1: Core Projects 4-94
4.16.4 Alternative 2: Core and Supplemental Projects 4-95
4.16.5 Comparative Analysis of the Alternatives 4-95
4.17 Transportation 4-96
4.17.1 Standards of Significance 4-96
4.17.2 No-Action Alternative 4-96
4.17.3 Alternative 1: Core Projects 4-97
4.17.4 Alternative 2: Core and Supplemental Projects 4-103
iv
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project Contents
(Continued)
4.17.5 Comparative Analysis of the Alternatives 4-104
4.18 Noise 4-105
4.18.1 Standards of Significance 4-105
4.18.2 No-Action Alternative 4-105
4.18.3 Alternative 1: Core Projects 4-105
4.18.4 Alternative 2: Core and Supplemental Projects 4-108
4.18.5 Comparative Analysis of the Alternatives 4-109
4.19 Socioeconomics 4-111
4.19.1 Standards of Significance 4-111
4.19.2 No-Action Alternative 4-111
4.19.3 Alternative 1: Core Projects 4-111
4.19.4 Alternative 2: Core and Supplemental Projects 4-112
4.19.5 Comparative Analysis of the Alternatives 4-113
4.20 Environmental Justice 4-114
4.20.1 Standards of Significance 4-114
4.20.2 No-Action Alternative 4-115
4.20.3 Alternative 1: Core Projects 4-115
4.20.4 Alternative 2: Core and Supplemental Projects 4-117
4.20.5 Comparative Analysis of the Alternatives 4-120
4.21 Other Sections Required by NEPAand CEQA 4-122
4.21.1 Unavoidable Adverse Effects 4-122
4.21.2 Relationship Between Short-Term Uses ofthe Environment and
Maintenance and Enhancement of Long-Term Productivity 4-122
4.21.3 Irreversible and Irretrievable Commitment of Resources 4-122
4.21.4 Growth-Inducing Impacts 4-124
4.21.5 Cumulative Effects 4-125
4.21.5.1 Past, Present, and Reasonably Foreseeable Actions within
Geographic Scope of Analysis 4-125
4.21.5.2 Cumulative Effects Analysis 4-129
5. MITIGATION MEASURES AND PERFORMANCE MONITORING 5-1
5.1 Summary of Significant Impacts and Mitigation 5-1
5.2 Mitigation Monitoring 5-20
5.3 Performance Monitoring of Project Effectiveness 5-20
6. COMPLIANCE WITH APPLICABLE ENVIRONMENTAL REGULATIONS 6-1
6.1 United States Regulations and Permits 6-1
6.1.1 Summary of Federal Cross-Cutting Authorities 6-1
6.1.2 Freshwater and Estuarine Resources 6-2
6.1.3 Marine Waters 6-6
6.1.4 Floodplains 6-7
6.1.5 Inland Biological Resources 6-8
6.1.6 Marine Biological Resources 6-11
6.1.7 Cultural Resources 6-13
6.1.8 Visual Resources 6-15
6.1.9 Coastal Zone 6-15
6.1.10 Air Quality and Odor 6-17
6.1.11 Climate 6-18
6.1.12 Solid and Hazardous Waste 6-19
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project Contents
(Continued)
6.1.13 Noise 6-20
6.1.14 Environmental Justice 6-20
6.2 Mexican Regulations and Permits 6-21
7. PUBLIC AND INTERAGENCY COORDINATION 7-1
7.1 Interagency Stakeholder Coordination Prior to Draft PEIS Development 7-1
7.1.1 Eligible Public Entities Coordinating Group 7-1
7.1.2 Technical Expert Consultation Process (TECP) 7-2
7.1.3 Natural Resources Workshop 7-5
7.2 Regulatory Consultation 7-5
7.2.1 Endangered Species Act Section 7 Consultation 7-5
7.2.2 Magnuson-Stevens Fishery Conservation and Management Act
Consultation (Essential Fish Habitat) 7-7
7.2.3 National Historic Preservation Act Section 106 Consultation 7-8
7.2.4 Government-to-Government Consultation with Native American
Tribes 7-8
7.3 Public Engagement and Review 7-9
7.3.1 Public Information Meetings 7-9
7.3.2 USIBWC Citizens Forum Meetings 7-10
7.3.3 South County Environmental Justice Taskforce 7-10
7.3.4 NEPA Public Scoping 7-11
7.3.4.1 Public Notification and Scoping Meeting 7-11
7.3.4.2 Summary of Scoping Comments 7-11
7.3.4.3 Summary of Submitted Alternatives, Information, and
Analyses 7-12
7.3.5 Public Review of Draft PEIS 7-12
7.3.5.1 Public Notification and Meetings 7-12
7.3.5.2 Summary of Public Comments 7-13
7.3.5.3 Summary of Submitted Alternatives, Information, and
Analyses 7-14
7.3.5.4 Summary of Changes Since the Draft PEIS 7-14
8. LIST OF PREPARERS AND REVIEWERS 8-1
9. REFERENCES CITED 9-1
APPENDIX A: Response to Comments on Draft Programmatic Environmental Impact Statement
APPENDIX B: Aquatic Resources Delineation Report
APPENDIX C: Class III Cultural Resource Inventory (Public Version)
APPENDIX D: USFWS Biological Assessment
APPENDIX E: Database Query Results for Special-status Species and Sensitive Natural
Communities
APPENDIX F: NMFS Biological Assessment
vi
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project Contents
(Continued)
APPENDIX G: NMFS Essential Fish Habitat Assessment
APPENDIX H: Coastal Consistency Determination
APPENDIX I: Supplemental Data for Environmental Justice Analysis
APPENDIX J: South Bay Ocean Outfall Plume Transport Modeling
APPENDIX K: Interpolation of Modeled Beach Impacts
APPENDIX L: Emissions Calculations
APPENDIX M: NHPA Section 106 Correspondence
APPENDIX N: Tribal Outreach Correspondence
APPENDIX 0: Distribution List
vii
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project List of Tables
LIST OF TABLES
Table ES-1. Significant Impacts to be Mitigated xxiii
Table 2-1. Projects Constituting Alternatives 1 and 2 2-5
Table 2-2. Comparison of Project A Options 2-11
Table 2-3. Tijuana Sewer Collectors Included in Project C for Rehabilitation or Replacement 2-19
Table 2-4. Comparison of Projects in the PEIS Proposed Action and Corresponding Projects
in Treaty Minute No. 328 2-50
Table 2-5. Related Projects to Mitigate Contaminated Transboundary Flows in the Tijuana
Area 2-53
Table 3-1. Average Annual Distribution of Transboundary Flows in the Tijuana River 3-4
Table 3-2. Precipitation and Flow Correlation for the Tijuana River 3-4
Table 3-3. Wetlands Mapped Within the Evaluated Areas 3-16
Table 3-4. Vegetation Types Mapped Within the Alternative 1 and 2 Areas 3-35
Table 3-5. Special-status Plant Species with the Potential to Occur Within the Evaluated
Area of Each Alternative 3-37
Table 3-6. Special-status Wildlife Species with Low, Moderate, or High Potential to Occur 3-43
Table 3-7. Species Listed Under the ESAor CESA with Medium to High Likelihood of
Occurrence in the Evaluated Area 3-56
Table 3-8. Marine Mammal Species with a Medium or High Likelihood of Occurrence in the
Evaluated Area and are Not Listed Under ESAor CESA 3-57
Table 3-9. Summary of Cultural Resources Intersecting the Project Area 3-66
Table 3-10. Federal and California Ambient Air Quality Standards 3-75
Table 3-11. Summary of Weather Data for Brown Field Municipal Airport 3-77
Table 3-12. Regional Disposal Facility Information 3-81
Table 3-13. AADT Counts for Selected Roads Within and Near the Tijuana River Valley 3-87
Table 3-14. Perception of Typical Noise Levels 3-88
Table 3-15. San Diego County and San Diego City Sound Level Limits 3-89
Table 3-16. Noise-Sensitive Receptors in the Vicinity of Project Areas 3-90
viii
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project List of Tables
(Continued)
Table 3-17. Currentand Projected Population of U.S. Communities in Vicinity ofProposed
Action 3-92
Table 3-18. Racial Demographics of U.S. Communities in Vicinity of Proposed Action, 2020 3-93
Table 3-19. Currentand Projected Employment of U.S. Communities in Vicinity ofProposed
Action 3-94
Table 3-20. Median Household Income ofU.S. Communities in Vicinity ofProposed Action 3-94
Table 3-21. Total Current Housing Units ofU.S. Communities in Vicinity of Proposed Action,
2020 3-95
Table 3-22. Communities in the EJ Study Area with Potential Environmental Justice
Concerns Based on EJScreen 2.0 Data 3-107
Table 3-23. Communities in the EJ Study Area with Potential Environmental Justice
Concerns Based on CalEnviroScreen 4.0 Data 3-109
Table 4-1. Summary of Potential Transboundary Effects Under the Proposed Action 4-1
Table 4-2. Impacts on Transboundary Flows in the Tijuana River - Alternative 1 4-4
Table 4-3. Impacts on Transboundary Flows in the Tijuana River, by Portion of Rainfall Year
(Annual Averages, Based on Data for 2016 Through 2019 Rainfall Years) -
Alternative 1 4-6
Table 4-4. Impacts on Transboundary Flows in the Tijuana River - Alternative 2 4-13
Table 4-5. Comparative Analysis of Effects - Freshwater and Estuarine Resources 4-16
Table 4-6. Impacts on Discharges to the Pacific Ocean via SAB Creek (Initial Operations) -
Alternative 1 4-19
Table 4-7. Impacts on Discharges to the Pacific Ocean via SAB Creek (Projected 2050
Conditions) - Alternative 1 4-20
Table 4-8. Impacts on Discharges to the Pacific Ocean via the SBOO (Initial Operations) -
Alternative 1 4-22
Table 4-9. Impacts on Discharges to the Pacific Ocean via the SBOO (Projected 2050
Conditions) - Alternative 1 4-24
Table 4-10. Impacts on Tourist (Dry) Season Nm at Imperial Beach (Initial Operations) -
Alternative 1 4-28
Table 4-11. Impacts on Tourist (Dry) Season Beach Impact Fraction (Initial Operations) -
Alternative 1 4-29
Table 4-12. Impacts on Discharges to the Pacific Ocean via SAB Creek - Alternative 2 4-30
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project List of Tables
(Continued)
Table 4-13. Impacts on Discharges to the Pacific Ocean via the SBOO (Initial Operations) -
Alternative 2 4-32
Table 4-14. Impacts on Discharges to the Pacific Ocean via the SBOO (Projected 2050
Conditions) - Alternative 2 4-33
Table 4-15. Comparative Analysis of Effects - Marine Waters 4-34
Table 4-16. Comparative Analysis of Effects - Floodplains 4-37
Table 4-17. Comparative Analysis of Effects - Inland Biological Resources 4-48
Table 4-18. Comparative Analysis of Effects - Marine Biological Resources 4-54
Table 4-19. Temporary Ground Disturbance in the U.S 4-56
Table 4-20. Comparative Analysis of Effects - Geological Resources 4-59
Table 4-21. Comparative Analysis of Effects - Cultural Resources 4-61
Table 4-22. Comparative Analysis of Effects - Visual Resources 4-66
Table 4-23. Comparative Analysis of Effects - Land Use 4-69
Table 4-24. Comparative Analysis of Effects - Coastal Zone 4-71
Table 4-25. Summary of Estimated Criteria Pollutant Emissions in the U.S. (Construction
and Operation) - Alternative 1 4-72
Table 4-26. Comparative Analysis of Effects - Air Quality and Odor 4-77
Table 4-27. Comparative Analysis of Effects - Climate 4-79
Table 4-28. Summary of Estimated Changes in Wastewater Process Solids Production under
Alternative 1 4-82
Table 4-29. Comparative Analysis of Effects - Solid and Hazardous Waste 4-84
Table 4-30. Summary of Estimated Increases in Electricity Demand for Core Projects 4-86
Table 4-31. Comparative Analysis of Effects - Energy 4-88
Table 4-32. Comparative Analysis of Effects - Public Services and Utilities 4-93
Table 4-33. Comparative Analysis of Effects - Public Health and Safety 4-96
Table 4-34. Summary of Estimated Changes inTruckloads and VMT for Solids Waste
Disposal 4-100
Table 4-35. Comparative Analysis of Effects - Transportation 4-104
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project List of Tables
(Continued)
Table 4-36. Comparative Analysis of Effects - Noise 4-110
Table 4-37. Comparative Analysis of Effects - Socioeconomics 4-114
Table 4-38. Comparative Analysis of Effects - Environmental Justice 4-121
Table 4-39. Past, Present, and Reasonably Foreseeable Actions Considered for Cumulative
Effects 4-126
Table 4-40. Cumulative Effects Analysis Scope and Project Matrix 4-130
Table 5-1. Significant Impacts to be Mitigated 5-2
Table 5-2. Summary of Mitigation Measures by Alternative and Project 5-5
Table 6-1. Summary of Applicability of Federal Cross-cutting Authorities by Alternative and
Project 6-2
Table 6-2. De Minimis Emissions Thresholds for General Conformity Applicability 6-18
Table 8-1. List of Preparers and Reviewers 8-1
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project List of Figures
LIST OF FIGURES
Figure 1-1. Overview of Tijuana River Valley 1-2
Figure 1-2. Overview of ITP Canyon Collector System 1-6
Figure 1-3. Photographs of Canyon Flow Diversion Structures 1-7
Figure 1-4. Overview of Existing Diversion and Treatment Infrastructure in Tijuana 1-10
Figure 1-5. Schematic of Existing Wastewater Diversion and Treatment System 1-11
Figure 1-6. Dry-Weather Transboundary Tijuana River Flow Days per Rainfall Year (2000-
2020) 1-14
Figure 1-7. Locations of Coastal Communities and U.S. Navy Facilities in the South Bay Area 1-16
Figure 1-8. Annual Beach Closures in Southern San Diego County (2003-2021) 1-17
Figure 2-1. Project A (Expanded ITP) - Schematic of Expanded ITP Treatment Train 2-8
Figure 2-2. Project A (Expanded ITP) - Locations of Project Components 2-9
Figure 2-3. Project A (Expanded ITP) - Conceptual Site Plan of Proposed Facilities 2-10
Figure 2-4. Project B (Tijuana Canyon Flows to ITP), Option B1 - Locations of Project
Components 2-15
Figure 2-5. Project B (Tijuana Canyon Flows to ITP), Option B2 - Locations of Project
Components 2-16
Figure 2-6. Project B (Tijuana Canyon Flows to ITP), Option B3 - Locations of Project
Components 2-17
Figure 2-7. Project C (Tijuana Sewer Repairs) - Schematic of Tijuana Sewer Collectors for
Rehabilitation or Replacement 2-20
Figure 2-8. ProjectD (APTP Phase 1) - Schematic of APTP Treatment Train 2-21
Figure 2-9. Ballasted Flocculation Process Flow Schematic 2-23
Figure 2-10. ProjectD (APTP Phase 1) - Locations of Project Components (1 of 2) 2-25
Figure 2-11. ProjectD (APTP Phase 1) - Locations of Project Components (2 of 2) 2-26
Figure 2-12. ProjectD (APTP Phase 1) - Conceptual Site Plan of Proposed Facilities 2-27
Figure 2-13. Projects E (APTP Phase 2) and F (U.S.-side River Diversion to APTP) -
Conceptual Locations of Project Components 2-30
Figure 2-14. Project G (New SABTP) - Conceptual Locations of Project Components 2-35
xii
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project List of Figures
(Continued)
Figure 2-15. Project I (ITP Treated Effluent Reuse) - Conceptual Locations of Project
Components 2-38
Figure 2-16. Project J (Trash Boom[s]) - Conceptual Locations of Project Components 2-40
Figure 3-1. Tijuana River Watershed 3-1
Figure 3-2. Annual Precipitation and Transboundary River Flow Days (by Daily Flow Rate),
2000-2020 Rainfall Years 3-3
Figure 3-3. Aquatic Resources Near the Proposed Action in the U.S. (1 of 7) 3-9
Figure 3-4. Aquatic Resources Near the Proposed Action in the U.S. (2 of 7) 3-10
Figure 3-5. Aquatic Resources Near the Proposed Action in the U.S. (3 of 7) 3-11
Figure 3-6. Aquatic Resources Near the Proposed Action in the U.S. (4 of 7) 3-12
Figure 3-7. Aquatic Resources Near the Proposed Action in the U.S. (5 of 7) 3-13
Figure 3-8. Aquatic Resources Near the Proposed Action in the U.S. (6 of 7) 3-14
Figure 3-9. Aquatic Resources Near the Proposed Action in the U.S. (7 of 7) 3-15
Figure 3-10. Floodplains in the Tijuana River Valley (FEMA) 3-29
Figure 3-11. 500-year Floodplain in the Tijuana River Valley (USACE Model) 3-30
Figure 3-12. Vegetation Types in the Evaluated Area for the Proposed Action (Upstream of
Dairy Mart Road Bridge) 3-32
Figure 3-13. Vegetation Types in the Evaluated Area for the Proposed Action (Detail of ITP
Parcel) 3-33
Figure 3-14. Vegetation Types in the Evaluated Area for the Proposed Action (Smuggler's
Gulch and Monument Road) 3-34
Figure 3-15. USFWS Critical Habitat in the Tijuana River Valley 3-48
Figure 3-16. Evaluated Area for Potential Project Effects Under the Proposed Action 3-53
Figure 3-17. Soil Map Units in the Tijuana River Valley 3-60
Figure 3-18. Geohazards in the Tijuana River Valley 3-63
Figure 3-19. Land Ownership in the Tijuana River Valley 3-71
Figure 3-20. Coastal Zone Boundary and LCP Jurisdictions in the Tijuana River Valley 3-73
Figure 3-21. General Locations of Noise-Sensitive Receptors in the Vicinity of Project Areas 3-91
xiii
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project List of Figures
(Continued)
Figure 3-22. Minority Percent of Population for Census Block Groups in San Diego County,
Based on EJScreen 2.0 Data 3-96
Figure 3-23. Low-Income Percent of Population for Census Block Groups in San Diego
County, Based on EJScreen 2.0 Data 3-97
Figure 3-24. Boundaries of the EJ Study Area for the Proposed Action 3-101
Figure 3-25. Minority Percentile (County) for Block Groups in EJ Study Area, Based on
EJScreen 2.0 Data 3-110
Figure 3-26. Low-Income Percentile (County) for Block Groups in EJ Study Area, Based on
EJScreen 2.0 Data 3-111
Figure 3-27. Unemployment Percentile (County) for Block Groups in EJ Study Area, Based
on EJScreen 2.0 Data 3-112
Figure 3-28. Air Toxics Cancer Risk Percentile (County) for Block Groups in EJ Study Area,
Based on EJScreen 2.0 Data 3-113
Figure 3-29. Traffic Proximity Percentile (County) for Block Groups in EJ Study Area, Based
on EJScreen 2.0 Data 3-114
Figure 3-30. Wastewater Discharge Percentile (County) for Block Groups in EJ Study Area,
Based on EJScreen 2.0 Data 3-115
Figure 3-31. PM2.5 Percentile (County) for Census Tracts in EJ Study Area, Based on
CalEnviroScreen 4.0 Data 3-116
Figure 3-32. Diesel PM Percentile (County) for Census Tracts in EJ Study Area, Based on
CalEnviroScreen 4.0 Data 3-117
Figure 3-33. Toxic Air Chemical Releases Percentile (County) for Census Tracts in EJ Study
Area, Based on CalEnviroScreen 4.0 Data 3-118
Figure 3-34. SB 535 DACs 3-119
Figure 4-1. Transboundary Flow Days in the Tijuana River per Rainfall Year (2000-2020)
and Portion Targeted by Alternative 1 4-7
Figure 4-2. Transboundary Flow Volume in the Tijuana River per Rainfall Year (2000-2020)
and Portion Targeted by Alternative 1 4-8
Figure 4-3. Dry-Weather Transboundary Flow Days and Volume in the Tijuana River per
Rainfall Year (2000-2020) and Portion Targeted by Alternative 1 4-9
Figure 4-4. Truck Routes Between ITP Parcel and Candidate Fill Source Locations 4-98
Figure 4-5. Truck Routes Between ITP Parcel and Candidate Regional Disposal Facilities (1
of 2) 4-101
xiv
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project List of Figures
(Continued)
Figure 4-6. Truck Routes Between ITP Parcel and Candidate Regional Disposal Facilities (2
of 2) 4-102
xv
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Abbreviations, Acronyms, and Symbols
ABBREVIATIONS, ACRONYMS, AND SYMBOLS
AADT
annual average daily traffic
AB
Assembly Bill
ac-ft/year
acre-feet per year
ACS
American Community Survey
APE
Area of Potential Effect
APTP
Advanced Primary Treatment Plant
AQIA
Air Quality Impact Assessment
ARPA
Archaeological Resources Protection Act
BACT
best available control technology
BFE
Base Flood Elevation
BGEPA
Bald and Golden Eagle Protection Act
bgs
below ground surface
BGY
billion gallons per year
BIF
beach impact fraction
BMP
best management practice
BODs
biochemical oxygen demand over a five-day period
BWIP
Border Water Infrastructure Program
CAAQS
California ambient air quality standards
CAH&SC
California Health and Safety Code
CalEPA
California Environmental Protection Agency
Cal trans
California Department of Transportation
CAPP
Community Air Protection Program
CARB
California Air Resources Board
CBP
United States Customs and Border Protection
CCA
California Coastal Act
CCC
California Coastal Commission
CCMP
California Coastal Management Program
CCR
California Code of Regulations
CDFW
California Department of Fish and Wildlife
CDP
Coastal Development Permit
CDPR
California Department of Parks and Recreation
CEQ
Council on Environmental Quality
CEQA
California Environmental Quality Act
CESA
California Endangered Species Act
CESPT
Comision Estatal de Servicios Publicos de Tijuana
CFR
Code of Federal Regulations
cfs
cubic feet per second
ch4
methane
c2h3ci
vinyl chloride
CILA
Comision International de Limites y Aguas
CNDDB
California Natural Diversity Database
CNPS
California Native Plant Society
CO
carbon monoxide
C02
carbon dioxide
C02e
carbon dioxide equivalent
CONAGUA
Comision Nacional del Agua
CPS
Coastal Pelagic Species
xvi
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Abbreviations, Acronyms, and Symbols
(Continued)
CRHR
California Register of Historical Resources
CRPR
California Rare Plant Rank
CWA
Clean Water Act
CZMA
Coastal Zone Management Act
DAC
disadvantaged communities
DAF
dissolved air flotation
dB
decibels
dBA
A-weighted decibels
ddPCR
digital droplet polymerase chain reaction
DPS
Distinct Population Segment
EFH
Essential Fish Habitat
EID
Environmental Information Document
EIS
Environmental Impact Statement
EISA
Energy Independence and Security Act
EJ
environmental justice
EO
Executive Order
EPA
United States Environmental Protection Agency
EPECG
Eligible Public Entities Coordinating Group
ESA
Endangered Species Act
FEM
Field Environmental Monitor
FEMA
Federal Emergency Management Agency
FIB
fecal indicator bacteria
FMP
Fishery Management Plans
FR
Federal Register
FT A
Federal Transit Administration
FWCA
Fish and Wildlife Coordination Act
GCR
General Conformity Rule
GHG
greenhouse gases
GWh
gigawatt-hours
GWh/yr
gigawatt-hours per year
H2S
hydrogen sulfide
HAB
harmful algal blooms
HAP
hazardous air pollutants
HAPC
Habitat Areas of Particular Concern
HDPE
high-density polyethylene
hp
horsepower
HPI
Healthy Places Index
HMS
Highly Migratory Species
hp
horsepower
IBC
International Boundary Commission
IBWC
International Boundary and Water Commission
IPaC
Information for Planning and Conservation
ITP
South Bay International Wastewater Treatment Plant
IWG
Interagency Working Group
JB-1
Junction Box 1
LCP
Local Coastal Program
lps
liters per second
LSA
Lake and Streambed Alteration
MACT
Maximum Achievable Control Technology
xvii
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Abbreviations, Acronyms, and Symbols
(Continued)
ME CAP LAN Mecanismo de Planeacion
MBTA Migratory Bird Treaty Act
Mcf/day million cubic feet per day
mg million gallons
mg/L milligrams per liter
MGD million gallons per day
MHPA Multi-Habitat Planning Area
MIA Manifestacion de Impacto Ambiental
MMPA Marine Mammal Protection Act
MPA Marine Protected Area
MRZ Mineral Resource Zones
MS4 municipal separate storm sewer system
MSCP Multiple Species Conservation Program
MSL mean sea level
NAAQS National Ambient Air Quality Standards
NADBank North American Development Bank
NAFTA North American Free Trade Agreement
NAGPRA Native American Graves Protection and Repatriation Act
NAHC Native American Heritage Commission
NAMPAN North American Marine Protected Area Network
NEPA National Environmental Policy Act
NESHAP National Emission Standards for Hazardous Air Pollutants
NHPA National Historic Preservation Act
Nm number of ill swimmers
NMFS National Marine Fisheries Service
NNL National Natural Landmark
NO2 nitrogen dioxide
N2O nitrous oxide
NOA Notice of Availability
NOAA National Oceanic and Atmospheric Administration
NOI Notice of Intent
NOx nitrogen oxides
NPDES National Pollutant Discharge Elimination System
NPPA Native Plant Protection Act
NRCS Natural Resources Conservation Service
NRHP National Register of Historic Places
NRWQC National Recommended Water Quality Criteria
NSR New Source Review
NWR National Wildlife Refuge
O3 ozone
OEHHA California Office of Environmental Health Hazard Assessment
OHP Office of Historic Preservation
OHWM ordinary high water mark
O&M operations and maintenance
PB1-A Pump Station 1A
PB1-B Pump Station IB
PB-CILA Planta de Bombeo CILA
PCG Pacific Coast Groundfish
PCS Pacific Coast Salmon
xviii
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Abbreviations, Acronyms, and Symbols
(Continued)
PEIS
Programmatic Environmental Impact Statement
PEM
palustrine emergent
PLOO
Point Loma Ocean Outfall
PM
particulate matter
PM2.5
fine particulate matter
PMio
respirable particulate matter
PRC
Public Resources Code
PSP
paralytic shellfish poisoning
PSS
palustrine scrub-shrub
PTE
potential-to-emit
PVC
polyvinyl chloride
RCD
Resource Conservation District
ROD
Record of Decision
ROV
remotely operated vehicle
RWQCB
Regional Water Quality Control Board
SAB
San Antonio de los Buenos
SABTP
San Antonio de los Buenos Wastewater Treatment Plant
SANDAG
San Diego Association of Governments
SB
Senate Bill
SBLO
South Bay Land Outfall
SBOO
South Bay Ocean Outfall
SBWRP
South Bay Water Reclamation Plant
SCB
Southern California Bight
SCEJTF
South County Environmental Justice Taskforce
SCIC
South Coastal Information Center
SDAPCD
San Diego County Air Pollution Control District
SDG&E
San Diego Gas & Electric
SDRWQCB
San Diego Regional Water Quality Control Board
SDWA
Safe Drinking Water Act
SEMARNAT
Secretaria de Relaciones Exteriores
SF
square feet
SFEI
San Francisco Estuary Institute
SFHA
Special Flood Hazard Area
SHPO
State Historic Preservation Officer
SMCA
State Marine Conservation Area
SMR
State Marine Reserve
S02
sulfur dioxide
SOI
Statement of Intent
SSC
Species of Special Concern
SWPPP
Stormwater Pollution Prevention Plan
SWRCB
State Water Resources Control Board
T-BACT
best available control technology for toxics
TBEL
technology-based effluent limitations
TDS
total dissolved solids
TECP
Technical Expert Consultation Process
TMDL
Total Maximum Daily Load
TNW
Traditional Navigable Water
tons/yr
tons per year
TRNERR
Tijuana River National Estuarine Research Reserve
xix
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Abbreviations, Acronyms, and Symbols
(Continued)
TSS
total suspended solids
U.S.
United States
USACE
United States Army Corps of Engineers
USD A
United States Department of Agriculture
USFS
United States Forest Service
USFWS
United States Fish and Wildlife Service
USGCRP
United States Global Change Research Program
USGS
United States Geological Survey
USIBWC
United States Section of the International Boundary and Water Commission
USMCA
United States-Mexico-Canada Agreement
VegCamp
Vegetation Classification and Mapping Program
VMT
vehicle miles traveled
VOC
volatile organic compounds
WHO
World Health Organization
WOS
Waters of the State
WOTUS
Waters of the United States
WQBEL
water quality-based effluent limitations
WWTP
wastewater treatment plant
xx
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Executive Summary
EXECUTIVE SUMMARY
The United States (U.S.) Environmental Protection Agency (EPA) and the U.S. International
Boundary and Water Commission (USIBWC), as joint lead agencies, are proposing to fund and
implement the United States-Mexico-Canada Agreement (USMCA) Mitigation of Contaminated
Transboundary Flows Project (the Proposed Action) to reduce transboundary flows from Tijuana
that cause adverse public health and environmental impacts in the Tijuana River watershed and
adjacent coastal areas. In accordance with the requirements of the National Environmental Policy
Act (NEPA) (42 U.S.C. 4321-4347), Council on Environmental Quality (CEQ) NEPA Implementing
Regulations (40 Code of Federal Regulations [CFR] Parts 1500-1508 [2022]), EPA Procedures for
Implementing NEPA (40 CFR Part 6), USIBWC NEPA Implementing Procedures (48 FR 44083), and
Executive Order 12114 (44 FR 1957), this Programmatic Environmental Impact Statement (PEIS)
supports an informed decision-making process, sets forth a tiered framework for future funding
decisions, considers reasonable alternatives, and reviews the environmental impacts of the
Proposed Action.
The San Diego-Tijuana region has faced persistent transboundary flows of contaminated
wastewater originating in Mexico for many years. The three primary entryways of these
transboundary flows into the U.S. are in coastal waters of the Pacific Ocean, the Tijuana River, and
tributaries flowing north through canyons to the Tijuana River Valley and Estuary. Seasonal marine
currents cause coastal discharges of largely untreated wastewater (sewage) from the Tijuana area
to migrate north along the Pacific Ocean coast into the U.S. These discharges impact southern San
Diego County beaches, especially during the summer. Additionally, transboundary flows in the
Tijuana River and its canyon tributaries routinely reach the U.S., bringing untreated wastewater
(sewage), trash, and sediment into the U.S. These contaminated flows can reach the Pacific Ocean
through the Tijuana River Valley and Estuary and migrate north along the coast, compounding the
impacts of coastal discharges from the Tijuana area. Collectively, these polluted transboundary
flows impact the environment and public health in communities along the border and the coast,
public access to beaches and recreational opportunities in southern California, and the personnel
and activities of U.S. Customs and Border Protection and the U.S. Navy.
The USMCA Implementation Act, signed in January 2020, appropriated funds to EPA for
implementation of wastewater infrastructure projects at the U.S.-Mexico border and authorized
EPA, in coordination with eligible public entities, to plan, design, and construct wastewater
(including stormwater) treatment projects in the Tijuana River area. EPA established the Eligible
Public Entities Coordinating Group (EPECG), consisting of federal, state, and local stakeholders, and
solicited their input on the set of project options to be considered for evaluation. EPA's Border
Water Infrastructure Program would also be utilized to fund and carry out certain activities under
this action.
EPA and USIBWC have identified two alternatives to address the purpose and need: a limited
funding approach for implementing the Proposed Action (Alternative 1) and a more comprehensive
solution for implementing the Proposed Action (Alternative 2), as well as a third alternative of no
disbursement of funding and continuation of current wastewater management practices (No-Action
Alternative). Both Alternative 1 and Alternative 2 are expected to have beneficial impacts to public
safety and water quality in the Tijuana River watershed and adjacent coastal areas. EPA and
USIBWC have identified Alternative 2 as the preferred alternative for the reasons described in
Section 2.6 (Identification of Preferred Alternative and Environmentally Preferable Alternative).
The alternatives cover a large geographic area and impact a broad range of resource areas,
including water resources, geologic resources, the coastal zone, air quality, climate, biological
xx i
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Executive Summary
resources, cultural resources, land use, visual resources, solid and hazardous waste, energy, public
services and utilities, public health and safety, transportation, noise, socioeconomics, and
environmental justice. The impacts to these resources under each alternative are analyzed in this
PEIS. A summary of significant and potentially significant impacts is provided in Table ES-1. In this
PEIS, EPA and USIBWC have identified mitigation measures to address these impacts as presented
in Section 5 (Mitigation Measures and Performance Monitoring).
Implementation of the Proposed Action would likely require federal authorizations and permits
pursuant to the Endangered Species Act, Clean Water Act, National Historic Preservation Act, and
Coastal Zone Management Act EPA has engaged and coordinated with federal agencies such as the
U.S. Fish and Wildlife Service, National Marine Fisheries Service, and U.S. Army Corps of Engineers,
and continuously works with other binational, state, and local agencies and stakeholders.
xxii
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Executive Summary
Table ES-1. Significant Impacts to be Mitigated
Significant Impact
No-Action
Alternative
Alternative 1
(Core Projects)
Alternative 2
(Comprehensive
Solution)
Freshwater and Estuarine Resources
Continuation of impacts to freshwater and estuarine resources and water quality degradation
X
Potential impacts to potential jurisdictional water of the U.S. for construction of U.S.-side river diversion
and trash boom(s) in Tijuana River main channel and floodplain
©
Potential permanent reduction in acreage of potential jurisdictional water resources in the Tijuana River
floodplain for the U.S.-side river diversion and trash boom[s] requiring an individual CWA 404 permit
©
Marine Waters
Continuation, and worsening over time, of existing marine water quality impacts
X
Substantial increase in pollutant loadings to Pacific Ocean via the SBOO
¦
¦ ©
Floodplains
[None identified]
Inland Biological Resources
Continuation of negative effects on inland biological resources resulting from contaminated transboundary
flows
X
Potential short-term substantial disturbances of special-status wildlife and fish species during construction
in Tijuana River main channel and floodplain, depending on the locations of the proposed river diversion
and trash boom(s)
©
Potential long-term substantial disturbances of special-status plant and wildlife species associated with
downstream riparian habitat due to reduced wet-weather transboundary flows
©
Potential long-term reduction in special-status fish migration ability and/or estuarine rearing conditions
due to reduced wet-weather transboundary flows
©
Marine Biological Resources
[None identified]
Geological Resources
[None identified]
Cultural Resources
[None identified]
Visual Resources
Potential detraction from the visual character or quality of the localized area due to introduction of
physical structures, land conversion, and O&M associated with the U.S.-side river diversion and trash
boom(s)
©
xxiii
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Executive Summary
Table ES-1. Significant Impacts to be Mitigated
Significant Impact
No-Action
Alternative
Alternative 1
(Core Projects)
Alternative 2
(Comprehensive
Solution)
Potential disproportionately high and adverse effect due to visual intrusions from U.S.-side river diversion
and/or trash boom(s)*
©
Land Use
[None identified]
Coastal Zone
[None identified]
Air Quality and Odor
Potential objectionable odor emissions from UP anaerobic digestion process
¦
¦ ©
Potential objectionable odors and/or impacts to sensitive receptors due to trash boom operations
©
Disproportionately high and adverse effect due to minor increase in PM2.5 and diesel PM emissions (due to
construction, operations, and/or commuting) in areas that currently experience extremely high
overburdens from PM2.5 and diesel PM*
¦
¦ ©
Disproportionately high and adverse effect due to objectionable odor emissions from UP anaerobic
digestion process*
¦
¦ ©
Potential for cumulative daily PM10 emissions (from the Proposed Action and concurrent restoration
activities at the nearby Nelson Sloan Quarry) to exceed AQIA trigger levels and result in disproportionately
high and adverse effect*
¦
¦ ©
Climate
Inconsistent with the City of San Diego Climate Action Plan due to an increase in GHG emissions
¦
¦ ©
Solid and Hazardous Waste
[None identified]
Energy
[None identified]
Public Services and Utilities
Potential impedance to CBP operations due to U.S.-side river diversion and trash boom(s)
©
Public Health and Safety
Exacerbation of unsafe field conditions for CBP personnel
X
Exacerbation of water quality issues at public beaches
X
Increase in unsafe field conditions for CBP personnel due to trash boom(s)
©
Introduction of breeding areas for disease-spreading vectors due to U.S.-side river diversion and trash
boom(s)
©
xxiv
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project Executive Summary
Table ES-1. Significant Impacts to be Mitigated
Significant Impact
No-Action
Alternative
Alternative 1
(Core Projects)
Alternative 2
(Comprehensive
Solution)
Potential disproportionately high and adverse effect due to proximity to disease vectors from U.S.-side
river diversion and/or trash boom(s)*
©
Transportation
Potential substantial localized increases in traffic volumes and congestion from Project J, depending on
frequency of trash hauling
©
Disproportionately high and adverse effects due to minor increases in traffic associated with operations,
commuting, and waste hauling in areas currently experiencing extremely high overburdens from traffic
impacts and/or traffic proximity*
¦
¦ ©
Noise
Potential localized, short-term exceedances of city and county noise levels during construction
¦
¦ ©
Potential for substantial, short-term increases in noise levels during construction in specific areas near
noise-sensitive receptors (e.g., protected species habitat and recreational areas in Smuggler's Gulch;
residences immediately adjacent to portions of Monument Rd)
¦
¦ ©
Potential long-term impacts from increase in noise due to continuous (or near-continuous) operation of
biogas-fired engine and electrical generator
¦
¦ ©
Socioeconomics
[None identified]
Environmental Justice
[See disproportionately high and adverse effects identified with an asterisk (*) listed in Visual Resources, Air
Quality and Odor, Public Health and Safety, and Transportation sections above in this table.]
* Indicates a disproportionately high and adverse effect that was identified in the environmental justice analysis (see Section 4.20 [Environmental Justice]) or
the environmental justice portion of the cumulative effects analysis (see Section 4.21.5 [Cumulative Effects]).
Symbol key:
X Significant impact is a result of the No-Action Alternative.
¦ Significant impact is a result of a Core Project(s).
© Significant impact is a result of a Supplemental Project(s).
¦ © Significant impact is a result of both a Core and Supplemental Project(s).
xxv
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Introduction
1. INTRODUCTION
1.1 Background
The Tijuana River watershed is a 1,750-square-mile watershed that includes portions of San Diego
County in California and northern Baja California in Mexico. Approximately three-quarters of the
watershed is in Mexico, including the cities of Tijuana and Tecate. The remaining quarter is in the
United States (U.S.), including portions of the cities of San Diego and Imperial Beach. The Tijuana
River originates in Mexico and flows northwest, crossing into the U.S. before ultimately discharging
to the Pacific Ocean via the Tijuana River Estuary (see Figure 1-1).
Deficiencies in the treatment, piping, and pump station network in Tijuana contribute to
contaminated transboundary flows entering the U.S. via coastal waters of the Pacific Ocean, the
Tijuana River, and tributaries that flow north through canyons to the Tijuana River Valley and
Estuary. Polluted transboundary maritime flows threaten the health of communities along the
border and the coast, impact marine and estuarine ecosystems, damage agricultural resources,
negatively impact the economy, and have the potential to affect training flexibility for U.S. military
activities, as there are U.S. Navy facilities within the affected area. Transboundary flows in the
Tijuana River and its canyon tributaries routinely reach the U.S., bringing untreated wastewater,
trash, and sediment into the U.S. These contaminated flows negatively impact U.S. Customs and
Border Protection (CBP) personnel and can reach the Pacific Ocean through the Tijuana River
Valley and Estuary and migrate north along the coast, compounding the impacts of coastal
discharges from the Tijuana area described above. Untreated wastewater contributes to high
bacterial concentrations in the Tijuana River and tributaries, creates health risks for recreational
users, and introduces other pollutants of concern that have led to the Tijuana River being listed as
an impaired water body under Section 303 of the Clean Water Act (CWA).
In 1889, the International Boundary Commission (IBC) was established by the U.S. and Mexico to
address concerns related to land jurisdiction and river boundaries. Transboundary flows crossing
into the U.S. from Mexico have raised water quality and human health concerns since at least the
1930s. The U.S. and Mexico have relied on binational collaborative efforts to address pollution near
the border of Tijuana and San Diego, as summarized below:
• 1944: The Treaty of February 3,1944 created a joint commission to address issues related
to the ownership of waters, sanitation, water quality, and flood control. The Treaty renamed
the previously existing IBC to the International Boundary and Water Commission (IBWC).
The U.S. is represented on the IBWC by the U.S. International Boundary and Water
Commission (USIBWC) and Mexico by the Comision International de Limites y Aguas (CILA),
Seccion Mexicana.
• 1965: The IBWC signed Treaty Minute No. 222, allowing for emergency sewer connection of
the City of Tijuana to the City of San Diego.
• 1972: The CWA was created, giving federal authority to the U.S. Environmental Protection
Agency (EPA) to regulate discharges into U.S. waters to improve water quality.
1-1
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Introduction
TIJUANA RIVER
ESTUARY
Pilot channel
gfrftrrnif-Tt'if)
PACIFIC
OCEAN
ffltaTTTTTiraTftn#! ,
'
Tijuana River Valley
Tijuana Slough National Wildlife Refuge
Tijuana River Valley Regional Park
Border Field State Park
South Bay Land Outfall (SBLO)
South Bay Ocean Outfall (SBOO)
y' CTYOF/.,
IMPERIAL* BEACH
NAVAL OUTLYING
LANDING F(ELD
IMPERIAL BEACH
SANvYSIDR O'
South Bay Water
Reclamation
Plant (SBWRP)
South Bay
International
Wastewater
Treatment
Plant (ITP)
Smuggler's
Gulch
UN,TtDtsT*TES
^MEXICO/;.
Goat
Canyon
I PB-CILA diversion '
.. D O W N TO W N
'" TIJUANA - .
Matadero Canyon
(Mexico side of
Smuggler's Gulch)
Los Laureles Canyon
(Mexico side of Goat Canyon)
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Figure 1-1. Overview of Tijuana River Valley
1-2
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Introduction
• 1983: Through the 1983 La Paz Agreement, the U.S. and Mexico agreed to protect and
enhance the environment surrounding the U.S.-Mexico border. The La Paz Agreement set
the framework to give joint authority to EPA and Mexico's Secretariat of Environment and
Natural Resources (Secretaria de Relaciones Exteriores, or SEMARNAT) for addressing
border pollution.
• 1985: IBWC signed Treaty Minute No. 270, providing recommendations for first-stage
treatment in Tijuana.
• 1990: USIBWC and CILA adopted Treaty Minute No. 283, which stipulates that "the
Government of Mexico will assure that there are no discharges of treated or untreated
domestic or industrial wastewaters into waters of the Tijuana River that cross the
international boundary."
• 1994: Through the North American Free Trade Agreement (NAFTA), the U.S. and Mexico
agreed to collaborate to develop joint environmental infrastructure projects, leading to the
creation of the Border Environment Cooperation Commission and the North American
Development Bank (NADBank), which help implement and finance water and wastewater
treatment projects along the U.S.-Mexico border.
• 1997: USIBWC and CILA collaborated to construct the South Bay International Wastewater
Treatment Plant (ITP) in the U.S. in response to a noticeable increase in transboundary
flows occurring due to population growth in Mexico throughout the 1980s and 1990s. The
project was completed in 1997, with advanced primary treated effluent discharged to the
Pacific Ocean via the Point Loma outfall. Upon completion of the project, untreated
wastewater that would enter the river was diverted to the new treatment plant, resulting in
improved water quality in the Tijuana River.
• 1999: USIBWC began discharging treated ITP effluent to the Pacific Ocean via the newly
constructed South Bay Ocean Outfall (SBOO) instead of the Point Loma outfall.
• 2000: The Tijuana River Valley Estuary and Beach Sewage Cleanup Act of 2000 (Public Law
106-457) was passed.
• 2005: USIBWC finalized the Supplemental Environmental Impact Statement (EIS) for CWA
compliance at the ITP and issued a Record of Decision (ROD) for an advanced primary
facility with secondary treatment in Mexico. In 2008, USIBWC rescinded the previous ROD
and issued a Revised ROD to upgrade the ITP under the Activated Sludge with Expanded
Capacity Alternative.
• 2013: The binational Border 2020 program was established in 2013 in accordance with the
1983 La Paz Agreement EPA and SEMARNAT identified the reduction of bacteria, sediment,
and trash into the Tijuana River Estuary as a top priority in the eight-year binational
program. EPA has since engaged with agencies, elected officials, and stakeholder groups in
both the U.S. and Mexico to help identify solutions to the persistent water quality issues in
the San Diego-Tijuana region.
• 2015: IBWC adopted Treaty Minute No. 320, which aims to reduce bacteria, sediment, and
trash in the Tijuana River watershed through binational collaboration. Recent deterioration
of infrastructure in Mexico—including many critical collection lines and pumps and the San
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Antonio de los Buenos Wastewater Treatment Plant (SABTP)—led to increased frequency of
poor water quality events (HDR, 2020a).
• 2018: The U.S. signed the United States-Mexico-Canada Agreement (USMCA), a trade
agreement that renegotiated and replaced NAFTA.
• 2020: In January 2020, Congress passed the USMCA Implementation Act, which
appropriated $300 million to EPA under Title IX of the Act for architectural, engineering,
planning, design, construction, and related activities in connection with the construction of
high-priority wastewater facilities in the U.S.-Mexico border area. Subtitle B, Section 821 of
the Act authorized EPA to plan, design, and construct wastewater (including stormwater)
treatment projects in the Tijuana River area. Based on that direction, EPA began
coordinating an interagency and binational effort to plan, design, and construct
infrastructure to reduce transboundary flows of untreated wastewater (sewage), trash, and
sediment that routinely enter the U.S. from Mexico via the Tijuana River, its tributaries, and
across the maritime boundary along the San Diego County coast The projects identified
through this effort form the basis of the alternatives evaluated in this PEIS.
• 2022: IBWC adopted Treaty Minute No. 328, which designates sanitation projects for
immediate implementation in San Diego and Tijuana as well as projects for future
consideration and negotiation. The treaty minute also identifies funding commitments from
the U.S. and Mexico for each of the immediate projects. See Section 2.8 (Funding Sources
and Binational Agreement) for additional information regarding this treaty minute.
On April 5, 2021, EPA published a Notice of Intent (NOI) to prepare an EIS (86 Federal Register [FR]
17595) for the Proposed Action pursuant to the requirements of the National Environmental Policy
Act (NEPA) (42 United States Code [U.S.C.] 4321-4347). Since the NOI was issued, EPA decided to
prepare a Programmatic EIS (PEIS) for the USMCA Mitigation of Contaminated Transboundary
Flows Project, which sets forth a framework for tiered decision making. USIBWC is a joint lead
agency for preparation of the PEIS. On June 17, 2022, EPA and USIBWC published a Notice of
Availability (NOA) for the Draft PEIS (87 FR 36487). Section 7.3.5.4 (Summary of Changes Since the
Draft PEIS) summarizes EPA and USIBWC's revisions to this document since release of the Draft
PEIS. The Proposed Action in this PEIS includes projects that address the purpose and need
described in Section 1.4 (Purpose and Need for Action) by achieving one or more of the following:
• Reducing the generation and/or discharge of contaminated flows from point and nonpoint
sources of pollution in the Tijuana region.
• Improving the collection and/or treatment of contaminated flows in the Tijuana region
before they reach the U.S.-Mexico border.
• Improving the collection and/or treatment of contaminated transboundary flows in the U.S.
This PEIS evaluates three alternatives: the No-Action Alternative, Alternative 1, and Alternative
2.EPA and USIBWC have identified Alternative 2 as the preferred alternative. This PEIS is prepared
in accordance with the Council on Environmental Quality (CEQ) NEPA Implementing Regulations
(40 Code of Federal Regulations [CFR] Parts 1500-1508 [2022]), EPA Procedures for Implementing
NEPA (40 CFR Part 6), USIBWC NEPA Implementing Procedures (48 FR 44083), and Executive
Order (EO) 12114 (44 FR 1957).
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1.2 Existing Diversion and Treatment Infrastructure
Existing treatment facilities and associated infrastructure in the U.S. include the South Bay
International Wastewater Treatment Plant, the South Bay Water Reclamation Plant, the South Bay
Land Outfall, the South Bay Ocean Outfall, and the canyon collector system, which are described as
follows (PG Environmental, 2021g) and identified in Figure 1-1, Figure 1-2, and Figure 1-3:
• The South Bay International Wastewater Treatment Plant (ITP) is located
approximately 1.3 miles west of where the Tijuana River enters the U.S., and about one-half
mile south of where Dairy Mart Road crosses over the Tijuana River. The existing plant is a
primary and secondary treatment system designed to treat an average daily flow of 25
million gallons per day (MGD) of wastewater from the International Collector in Mexico
(including diverted Tijuana River flows), as well as dry-weather flows from the canyon
collector system. The ITP began operation in 1997 with advanced primary treatment, was
expanded in 2011 to include secondary treatment, and was further expanded in 2018 to
include additional secondary sedimentation tanks to improve activated sludge process
performance. The ITP is owned by USIBWC and operated by a contract operator, Veolia.
• The South Bay Water Reclamation Plant (SBWRP) was constructed in 2002 by the City of
San Diego on a 22-acre site adjacent to the ITP and currently treats wastewater collected
from U.S. communities only. The existing SBWRP is designed to treat an average daily flow
of 15 MGD and apeak daily flow of 35 MGD. The treatment process consists of preliminary,
primary, and secondary treatment for discharged effluent, plus tertiary treatment and
disinfection of effluent for beneficial reuse.
• The South Bay Land Outfall (SBLO) is a tunnel extending from the effluent distribution
vault near the ITP and SBWRP to a point near the coastline and then discharges to the
South Bay Ocean Outfall (SBOO). The SBOO is a pipe, designed to handle an average flow
of 174 MGD, with a wye diffuser system atthe end that extends 3.5 miles offshore to
discharge treated effluent from both the ITP and the SBWRP into the Pacific Ocean.
• The canyon collector system (Figure 1-2 and Figure 1-3) consists of canyon flow diversion
structures1 in Goat Canyon, Smuggler's Gulch, Canon del Sol, Silva Drain, and Stewart's
Drain in the U.S., which are designed to capture transboundary dry-weather flows from
Mexico and convey them through canyon collector pipelines to the ITP for treatment and
discharge to the Pacific Ocean through the SBOO. The average design flow rates of the
diversion structures are 2.33 MGD at Goat Canyon, 4.67 MGD at Smuggler's Gulch, 0.67 MGD
at Canon del Sol, 0.33 MGD at Silva Drain, and 1.67 MGD at Stewart's Drain (Arcadis, 2019).
Actual flows from the canyon collector system to the ITP average approximately 0.6 MGD in
total (PG Environmental, 2021g).
1 The canyon flow diversion structures along the U.S.-Mexico border consist of culverts, concrete approach
pads, and grated intakes that drain to the ITP headworks via subsurface gravity piping. These are also
referred to as "canyon collectors" in HDR (HDR, 2020a).
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Final Programmatic EIS: USMCA Mitigation of
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Canyon collector pipeline (generalized)
[SaturnlBlycl]
Pump
station
South Bay
International
Wastewater
Treatment
Plant (UP)
Pump
station
Smuggler's Gulch
diversion
Goat Canyon
diversion
[unitedj
Stewart's Drain
diversion
Silva Drain
diversion
Canon del Sol
diversion
MATADERO
SAN
DIEGO
CANYON'
f LOS LAURELES \
/ \
/ CANYON
IMPERIAL
BEACH.
CHULA
VISTA
Figure 1-2. Overview of UP Canyon Collector System
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Final Programmatic EIS: USMCA Mitigation of
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Smuggler's Gulch
4.67 MGD design flow
Canon del Sol
0.67 MGD design flow
Silva Drain
0.33 MGD design flow
Stewart's Drain
1.67 MGD design flow
Goat Canyon
2.33 MGD design flow
Figure 1-3. Photographs of Canyon Flow Diversion Structures
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Tijuana has a complex piping and pumping network to transfer both wastewater and wet-weather
flows from a series of sources for treatment. Figure 1-4 shows the locations of key components of
the system in Tijuana. Figure 1-5 provides a schematic illustration of the existing river and
wastewater diversion system in Tijuana and its connection to the ITP. The existing infrastructure is
described as follows (PG Environmental, 2021g, 2021j):
• Diverted river water and wastewater from the Tijuana River, and wastewater from the
International Collector (the portion that is not conveyed to the ITP), are pumped to the San
Antonio de los Buenos Wastewater Treatment Plant (SABTP), which discharges into the
Pacific Ocean via San Antonio de los Buenos (SAB) Creek at Punta Bandera. The SABTP
began operation in 1987 as an aerated lagoon system with a design flow rate of 750 liters
per second (lps) (17 MGD). It was expanded in 2003 with surface aerators to treat a flow
rate of 1,100 lps (25 MGD). By the original design, the SABTP is intended to treat
wastewater received from the International Collector via Pump Station IB (PB1-B);
however, as discussed in Section 1.3.1 (Causes of Contaminated Transboundary Flows),
current operations at the SABTP do not effectively improve water quality prior to discharge.
• The La Morita Wastewater Treatment Plant (WWTP) is the easternmost WWTP in
Tijuana, serving communities in the far southeast portion of the city and surrounding areas
beyond the city boundary. The plant is designed for a capacity of 5.8 MGD. The Arturo
Herrera WWTP is also located in eastern Tijuana, about 2 miles downstream from the La
Morita WWTP and serving communities in southeast Tijuana. The plant is designed for a
capacity of 10.5 MGD. Both plants' effluent is discharged, with reportedly high water quality
(biochemical oxygen demand over a five-day period [BODs] under 10 milligrams per liter
[mg/L]) (IBWC, 2020), to the Tijuana River upstream of the diversion.
• The Planta de Bombeo CILA pump station (PB-CILA) is located along the Tijuana River
channel just south of the U.S.-Mexico border and is owned and operated by CILA. When the
PB-CILA river diversion system is functioning properly, all dry-weather flow (up to 23
MGD) in the Tijuana River is diverted before transboundary flows occur. The diverted flow
is routed to Pump Station 1A (PB1-A) or into the International Collector. The PB-CILA river
diversion system was upgraded in 2021 with a new river intake, new bar screens, a new
vortex desander, and new pumps to improve reliability and provide the capability to divert
up to 35 MGD of river flows.2
• The International Collector is located in the north area of Tijuana near the Tijuana River
and the international border. It consists of about 1.5 miles of 72-inch reinforced concrete
pipe with a design flow capacity of about 103 MGD. The International Collector receives
untreated wastewater collected in downtown Tijuana and the portion of diverted river
water from PB-CILA that is not sent to PB1-A. The mixture of untreated wastewater and
river water flows by gravity in the International Collector from east to west At the west end
2 The recent PB-CILA capacity upgrade to 35 MGD is not, on its own, sufficient to allow diversion and
treatment of more than 23 MGD unless supplemented by operational protocol changes (specifically, a new
treaty minute to require diversion of 35 MGD) and modifications to address other failing components of the
diversion and pumping system (specifically, PB1-A).
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Final Programmatic EIS: USMCA Mitigation of
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of the conveyance, a diversion box directs about 25 MGD to the ITP with the remainder
being pumped to the SABTP by PB1-B.
• The Tijuana metropolitan area wastewater collection system collects wastewater from
about 89 percent of city residents and, when functioning properly, conveys it to the ITP,
SABTP, La Morita WWTP, or Arturo Herrera WWTP. The remaining 11 percent of Tijuana's
current population does not have access to sanitary service (Arcadis, 2019). The population
of Tijuana is projected to increase by nearly 40 percent from 2020 to 2050 (NADBank et al.,
2020; PG Environmental, 2021g), resulting in significant additional volumes of domestic
wastewater that require collection and conveyance to treatment facilities.
• Pump Station 1A (PB1-A) is a sanitary sewer pump station in Tijuana that receives flow
from PB-CILA. It is operated by the Comision Estatal de Servicios Publicos de Tijuana (State
Public Service Commission of Tijuana [CESPT]), the Mexican public utility responsible for
supplying drinking water and sewage services to Tijuana. PB1-A has a single operational
parallel pump train consisting of a dual set of pumps in series. Under proper operating
conditions, PB1-A receives diverted river water from PB-CILA and conveys these flows via
one of two 10-mile pipelines (the "parallel conveyance pipelines") to an outfall into SAB
Creek as shown in Figure 1-4. PBl-A's current pumping capacity of about 11.5 MGD (500
lps) is considered to be the limiting factor that prevents PB-CILA from diverting more flow
from the Tijuana River. When PB1-A is not operating properly (often due to mechanical or
electrical challenges), PB-CILA either pumps diverted river water into the International
Collector or shuts off and allows transboundary flows to occur in the Tijuana River main
channel.
• Pump Station IB (PB1-B) is a sanitary sewer pump station in Tijuana operated by CESPT
that receives flow from the International Collector. PB1-B has two parallel pump trains,
each with a dual set of pumps in series. Flows from PB1-B are pumped south to the SABTP
and SAB Creek via the parallel conveyance pipelines. PBl-B's total station pumping capacity
is 23 MGD (1,000 lps). When PB1-B is operating at a reduced capacity (e.g., due to
insufficient power availability), the ITP must receive a higher proportion of the flows in the
International Collector, even if this results in exceeding the plant's design average daily flow
capacity of 25 MGD.
• The Mexico-side canyon pump stations include the Matadero Pump Station in Matadero
Canyon (i.e., the portion of Smuggler's Gulch in Mexico) and the Los Laureles 1 and Los
Laureles 2 Pump Stations in Los Laureles Canyon (i.e., the portion of Goat Canyon in
Mexico). When the pump stations are operating properly, approximately 6.3 MGD of dry-
weather wastewater flows in the canyons are conveyed via the Tijuana sanitary sewer
system to the SABTP, along with approximately 2.2 MGD of wastewater flows from the
Playas Pump Station serving the Playas de Tijuana neighborhood. The canyon pump
stations do not convey any "disconnected" flows that drain directly into the canyons.
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Final Programmatic EIS: USMCA Mitigation of
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Existing pump stations
Existing International Collector
South Bay Land Outfall (SBLO)
South Bay Ocean Outfall (SBOO)
SBOO
.UNITED
[MEXICO
Los Laureles 1
Matadero
Los Laureles 2
Arturo Herrera WWTP
f ] La Morita WWTP
San Antonio ^
de los Buenos m
WWTP
Rodriguez Dam
Impoundment
SAN
DIEGO
SAB Creek
Tijuana
River
RODRIGUEZ DAM AND WWTPS
SAB WWTP AND SAB CREEK
Service Layer Credits: Esri, HERE, Garmin, (c) OpenStreetMap contributors, and the GIS user community
Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographies, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN,
and the GIS User Community
Figure 1-4. Overview of Existing Diversion and Treatment Infrastructure in Tijuana
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City of Imperial Beach
San Diego
Note: Figure is not to scale.
Not shown (see Figure 1-3):
- La Morita WastewaterTreatment Plant
- Arturo Herrera WastewaterTreatment Plant
- Rodriguez Dam Impoundment
UNITED STATES
MEXICO
San Antonio de
los Buenos
Wastewater
Treatment Plant
(SABTP)
San Antonio de los
Buenos Creek
(SAB Creek)
Figure 1-5. Schematic of Existing Wastewater Diversion and Treatment System
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Final Programmatic EIS: USMCA Mitigation of
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Rodriguez Dam, while not a component of the wastewater diversion and treatment system, controls
flows from approximately 56 percent of the Tijuana River watershed (City of San Diego, 2012) and
greatly influences flows in the Tijuana River and therefore the operation of the diversion system.
The dam, located approximately 11 miles upstream from where the Tijuana River crosses the U.S.-
Mexico border, impounds flows from the Rio de las Palmas, creating the Rodriguez Dam
impoundment. The watercourse downstream of the dam is identified as the Tijuana River. With
construction completed in 1936, the Rodriguez Dam impoundment was originally intended to
satisfy the water needs of Tijuana, a small city at that time (City of San Diego, 2012). However, the
impoundment can no longer satisfy the current water demand of Tijuana. The Rodriguez Dam has a
capacity of 76,210 acre-feet at the spillway crest and 111,070 acre-feet at the top of the spillway
gates (IBWC, 1966). During the 2021 calendar year, the Rodriguez Dam had an average total
storage of approximately 11,620 acre-feet. The dam only releases water to the Tijuana River during
extreme runoff events. The water in the Rodriguez Dam impoundment falls under the jurisdiction of
Comision Nacional del Agua (CONAGUA) (PG Environmental, 202 If).
1.3 Causes and Impacts of Contaminated Transboundary Flows from Tijuana
1.3.1 Causes of Contaminated Transboundary Flows
Deficiencies in the treatment, piping, and pump station network in Tijuana described in Section 1.2
(Existing Diversion and Treatment Infrastructure) contribute to contaminated transboundary flows
entering the U.S. via coastal waters of the Pacific Ocean, the Tijuana River, and tributaries that flow
north through canyons to the Tijuana River Valley and Estuary. Specific deficiencies, as summarized
below, are described in further detail in the Feasibility Analysis memoranda for each project option
and the Baseline Conditions Summary (PG Environmental, 2021d, 2021a, 2021b, 2021c, 2021e,
2021f, 2021g, 2021h, 2021j, 2021i, 2021k, 20211, 2021m).
• Conveyance of untreated wastewater and diverted river water to SABTP, and inability
to treat these flows prior to coastal discharge via SAB Creek. A variety of operational
and capacity issues have necessitated that untreated wastewater flows from PB1-B be
mixed with the river diversion flows from PB1-A, resulting in mixed Tijuana River water
and wastewater being conveyed through the parallel conveyance pipelines to the SABTP or
directly to SAB Creek. The SABTP in its current condition does not improve the water
quality of the effluent. Additionally, river flows from PB1-A are designed to bypass the
SABTP and are conveyed directly to SAB Creek. As a result of these two factors,
approximately 35.5 MGD of mixed Tijuana River water and wastewater is discharged from
the parallel conveyance pipelines to the Pacific Ocean via SAB Creek, approximately 28.2
MGD of which is untreated wastewater. These dry-weather flows can vary depending on a
variety of factors, including PB-CILA operations, spills, and time of day. Seasonal marine
currents cause these coastal discharges of largely untreated wastewater (sewage) to
migrate north along the Pacific Ocean coast into the U.S.
• Inconsistent diversion of dry-weather river and canyon flows. Transboundary flows via
the river and canyons along the border can occur at any time of the year when the diversion
and pumping system is not functioning as designed. Breakdowns or power outages at the
river diversion or canyon pump stations or physical blocking of the diversion inlets by trash
frequently result in dry-weather flows crossing the border, bringing untreated wastewater,
sediment, and trash into the U.S. Figure 1-6 shows a graphical representation of the number
of days per year in which dry-weather transboundary river flows entered the U.S. during
each rainfall year from 2000 to 2020. This figure shows significant increases in the
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occurrence of dry-weather transboundary flows during the 2017 and 2020 rainfall years,
corresponding with extended periods where PB-CILA was shut down. As noted earlier in
this section, the recent PB-CILA capacity upgrade to 35 MGD will not prevent these dry-
weather river flows unless supplemented by further infrastructure and protocol
modifications.
• Inability to divert wet-weather river and canyon flows. While dry-weather flows from
the Tijuana River are intended to be diverted in Tijuana before reaching the U.S., the
amount of river flow that occurs during and after rain events generally exceeds the capacity
of the Tijuana diversion system. In such instances, to protect the pumps from sediment and
trash, the river diversion and PB-CILA shut down (typically for a multi-day period), and
flows cross the border into the U.S. instead. The flow rate in the river can reach several
billion gallons per day during large rain events. Operators in Mexico reengage PB-CILA once
river flows have subsided to within the pump's operating capacity, a period that can range
from a few days to weeks. Additionally, transboundary wet-weather flows in the canyons
occasionally exceed the capacity of U.S.-side drainage systems, resulting in localized
flooding and persistent road closures.
• Deteriorating infrastructure in Mexico. Other existing infrastructure in Mexico is in poor
condition or is not properly maintained and contributes to transboundary flows of
untreated wastewater. An average of approximately 10 MGD (based on 2016-2019 data) of
wastewater escapes the Tijuana metropolitan area wastewater collection system and flows
into the Tijuana River, primarily because of sewer system deterioration and pump station
mechanical failures. Sanitary wastewater generated by the unsewered 11 percent of
Tijuana's current population appears to flow directly to the Tijuana River. In Goat Canyon,
transboundary wastewater flows during dry weather have increased in the last two years,
possibly due to increased leaks from the wastewater collection system in Los Laureles
Canyon in Tijuana. This further exacerbates the impacts of the canyon flow diversion
failures described above. Additionally, the International Collector requires rehabilitation to
prevent untreated wastewater from spilling into the Tijuana River and Stewart's Drain.
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Note: For purposes of this analysis, "dry-weather" conditions indicate that the flow occurred at least five days after
the most recent precipitation registered at San Diego International Airport, and the flow rate did not exceed 23
MGD. A select few flow events that exceeded the 23-MGD threshold were considered dry-weather due to either
the time of year they occurred with no registered precipitation, or they varied only slightly above 23 MGD during a
period that was predominantly dry-weather.
Figure 1-6. Dry-Weather Transboundary Tijuana River Flow Days per Rainfall Year (2000-2020)
Mechanical issues at the ITP can occasionally contribute to these transboundary flows. For example,
a mechanical failure at Junction Box 1 (JB-1) in January 2022 restricted influent flow to the ITP,
thus increasing back pressure and resulting in leakage through a deteriorated section of the
International Collector in Mexico. This leak flowed through Stewart's Drain, exceeding the diversion
capacity and reaching the Tijuana River in the U.S. for a period of approximately one week.
Dry-weather flows in the main channel of the Tijuana River south of the border (i.e., upstream)
typically range between 20 to 30 MGD, including approximately 10 MGD of treated effluent from La
Morita WWTP and Arturo Herrera WWTP and 4 to 5 MGD of flows from the Alamar River. The
remainder consists of untreated wastewater and "urban drool" (i.e., unnatural, unpermitted, non-
exempted dry-weather flows) (PG Environmental, 202 lg). If wastewater production and discharges
to the Tijuana River continue to increase from population growth and/or urbanization, future dry-
weather flows will increasingly stress the operational capabilities of the diversion and pumping
system in Tijuana, and the frequency, volume, and impact of transboundary river flows on the U.S.
side could increase.
Uncontrolled trash, waste tires, and sedimentation are ongoing issues in the Tijuana River
watershed. Uncontained trash and solid waste from Tijuana cause damage and increase operations
and maintenance (O&M) requirements at the conveyance and treatment systems designed to
mitigate transboundary flows. Unpaved roads, channel erosion, broken water mains, and erosion of
disturbed areas contribute to transboundary flows of sediment via the Tijuana River and tributary
canyons.
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1.3.2 Impacts of Contaminated Transboundary Flows
The three primary entryways of contaminated transboundary flows from Tijuana into the U.S. are
in coastal waters of the Pacific Ocean, in the Tijuana River, and in tributaries that flow north
through the canyons to the Tijuana River Valley and Estuary.
Polluted transboundary maritime flows threaten the health of communities along the border and
the coast, impact marine and estuarine ecosystems, damage agricultural resources, negatively
impact the economy, and have the potential to limit training flexibility for U.S. military activities.
See Figure 1-7 for locations of coastal communities and U.S. Navy facilities in the South Bay area.
Poor coastal water quality, driven by both maritime and riverine transboundary flows, has caused
frequent beach closures in southern San Diego County, particularly for the beaches closest to the
U.S.-Mexico border. The beaches at Imperial Beach Pier and Border Field State Park have averaged
66 and 170 closure days per year since 2003, respectively, with even more frequent closures at
Border Field State Park in recentyears (averaging 262 closure days per year since 2019). Figure
1-8 depicts the annual number of beach closure days at Border Field State Park, Imperial Beach
Pier, and Silver Strand State Beach from 2003 to 2021. Additionally, as discussed in Section 3.2.2
(Marine Water Quality), beach closures and warning days in southern San Diego County have
significantly increased since May 2022, when the county implemented a new and more sensitive
water quality monitoring method for bacteria (Elmer, 2022a). Recent ocean modeling simulations
indicate that transboundary maritime flows of untreated wastewater discharged via SAB Creek at
Punta Bandera pose a substantial health risk to swimmers at beaches in southern San Diego County
during the dry (tourist) season (Feddersen et al., 2021). Eliminating or dramatically reducing these
inflows would strongly benefit water quality and public health at beaches in the City of Imperial
Beach, Silver Strand State Beach, and the City of Coronado. Poor coastal water quality also
contributes to the relocation, rescheduling, and cancellation of in-water Navy training and activities
(Navy Region Southwest, 2022).
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Introduction
PACIFIC
OCEAN
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Tijuana River Valley
South Bay Land Outfall (SBLO)
South Bay Ocean Outfall (SBOO)
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SAN
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Figure 1-7. Locations of Coastal Communities and U.S. Navy Facilities in the South Bay Area
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Final Programmatic EIS: USMCA Mitigation of
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Introduction
300
250
Border Field State Park Imperial Beach Pier ¦ Silver Strand State Beach
o 200
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50
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2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
Calendar Year
Source: (City of Imperial Beach, 2022).
Figure 1-8. Annual Beach Closures in Southern San Diego County (2003-2021)
In addition to the transboundary maritime flows described above, transboundary flows in the
Tijuana River and its canyon tributaries routinely bring untreated wastewater, trash, and sediment
into the U.S. These contaminated flows negatively impact CBP personnel and can reach the Pacific
Ocean through the Tijuana River Valley and Estuary and migrate north along the coast,
compounding the impacts of coastal discharges from the Tijuana area described above.
Contaminated flows from the Tijuana River, when they reach coastal areas, cause numerous beach
closures, and recent ocean modeling simulations indicate that these flows pose a substantial health
risk to swimmers at beaches in southern San Diego County during the wet (non-tourist) season
(Feddersen etal., 2021). Untreated wastewater contributes to high bacterial concentrations in the
Tijuana River and tributaries, creating health risks for recreational users, and introduces other
pollutants of concern (see Section 3.1.2 [Surface Water Quality]) that have led to the Tijuana River
being listed as an impaired water body under Section 303 of the CWA. Trash accumulation presents
human health concerns by way of exposures to toxic substances and ponding that can encourage
spread of disease vectors, diminish aesthetics, and contribute to odor issues. Sediment deposition
reduces the flow capacity of the river and tidal flow exchange in the estuary. Despite repeated
efforts to mitigate transboundary wastewater flows, the Tijuana River remains the most polluted
river in the San Diego region (HDR, 2020a).
1.4 Purpose and Need for Action
The Proposed Action, as summarized in Section 2.2 (Proposed Action and Range of Alternatives
Evaluated in This PEIS), is the funding and implementation of water infrastructure projects using
U.S. appropriations, including but not limited to USMCA Implementation Act appropriations. In
accordance with the CWA and the USMCA Implementation Act, the purpose and need of the
Proposed Action is to reduce transboundary flows from Tijuana that convey pollutants, sewage,
and/or trash into the U.S. and cause adverse public health and environmental impacts in the
Tijuana River watershed and adjacent coastal areas as described in Section 1.3 (Causes and Impacts
of Contaminated Transboundary Flows from Tijuana).
1-17
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Introduction
1.5 Purpose and Scope of the Programmatic EIS
EPA and USIBWC are joint lead agencies, in accordance with 40 CFR § 1501.7, for preparation of
this PEIS. On May 26, 2021, USIBWC sent a letter to EPA requesting to be joint lead agencies.
Previously, USIBWC had been intricately involved through various other interagency coordination
efforts, such as the Eligible Public Entities Coordinating Group (EPECG). On October 28, 2021, EPA
replied with a letter formalizing the agreement to be joint lead agencies. USIBWC contributed to
prepare and develop this PEIS and participated in public outreach efforts. In the arrangement, EPA
serves as the final authority on issues to be resolved between the agencies.
Jointly, EPA and USIBWC have prepared this PEIS to support an informed decision-making process,
consider reasonable alternatives to and review the environmental impacts of the Proposed Action,
and identify and support applicable consultations. The PEIS was based, in part, on preliminary
research and analysis in the Environmental Information Document (EID) USMCA Mitigation of
Contaminated Transboundary Flows Project, an EPA-prepared document that was finalized in
December 2021. The EID supported the Proposed Action by providing EPA and USIBWC with
existing conditions and baseline information to inform the PEIS.
The PEIS is a Programmatic NEPA document, meaning it addresses an initial programmatic decision
to be made and establishes a tiering process for subsequent decisions to be made that are
supported, in part, by the analysis detailed in the Programmatic NEPA document. The initial
programmatic decision to be made involves which approach EPA and USIBWC should take in
funding and implementing water infrastructure projects: no disbursement of funding and
continuation of current wastewater management practices (No-Action Alternative), a limited
approach (Alternative 1), or a more comprehensive solution (Alternative 2). The Core Projects
found in Alternative 1 are sufficiently evolved to be ready for decision making and, after completing
the NEPA process, would be considered analyzed in sufficient detail for action to be taken
immediately. In contrast, the comprehensive solution (Alternative 2) includes a larger range of
projects known as the Supplemental Projects, several of which are not yet ready for decision
making. These Supplemental Projects require additional consideration in subsequent tiered NEPA
documents before a decision can be made and action can be taken (for additional information on
tiering, see 40 CFR § 1501.11). Only the specific Supplemental Projects identified in this PEIS shall
be covered under this programmatic framework; no additional projects would be added after the
fact (i.e., after a decision has been made) unless addressed by a supplement to this PEIS. By
establishing this tiering framework, EPA and USIBWC aim to accomplish the following:
• Make a broad programmatic decision about which funding approach to take.
• Provide a comprehensive baseline analysis from which subsequent site-specific proposals
(Supplemental Projects) can be tiered.
• Efficiently analyze and make decisions on funds for Core Projects that are more evolved in
planning and design than Supplemental Projects and thus ready for decision making.
• Avoid repetition by using the PEIS as a foundation for the environmental review in
subsequent tiered NEPA documents.
• Streamline the later environmental review processes of Supplemental Projects so that they
may move forward as soon as they are sufficiently evolved for decision making and action.
1-18
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Introduction
Following completion of this PEIS, EPA and USIBWC intend to issue and sign a joint ROD that
identifies the decision on the Proposed Action by selecting an alternative. The joint ROD will
include committed mitigation measures and will establish the framework for completing additional
subsequent NEPA reviews to be tiered to the PEIS, if applicable.
The scope of the PEIS consists of a description of the alternatives to address transboundary
wastewater flows, a description of the affected environment, a discussion of the environmental
consequences of the Proposed Action, an analysis of the cumulative effects of the Proposed Action, a
discussion of compliance with applicable environmental regulations, a list of possible measures to
mitigate the environmental consequences of the Proposed Action, and a summary of public and
interagency coordination.
The PEIS covers the resource areas listed below.
• Water resources
• Geological resources
• The coastal zone
• Air quality
• Climate
• Biological resources
• Cultural resources
• Land use
• Visual resources
• Solid and hazardous
waste
• Energy
• Public services and
utilities
Public health and
safety
Transportation
Noise
Socioeconomics
Environmental justice
Although this environmental review focuses on impacts in the U.S. resulting from projects with
components located in the U.S., transboundary impacts (i.e., those occurring in one country because
of an action in a different country) were considered to the extent appropriate and consistent with
applicable guidance. For projects located in the U.S., this analysis includes consideration of those
transboundary impacts extending into Mexico that are reasonably foreseeable, consistent with CEQ
Guidance on NEPA Analyses for Transboundary Impacts (CEQ, 1997a). For projects located entirely
in Mexico, this analysis includes consideration of reasonably foreseeable impacts that would affect
the U.S. For projects located entirely in Mexico, resulting impacts located entirely in Mexico were
not included for consideration in this PEIS. This approach is consistent with the following EPA
guidance memoranda for border infrastructure grant programs: Guidance for EPA Environmental
Review ofNADBank Projects (EPA, 1997) and National Environmental Policy Act (NEPA) Application
to Mexican Border Infrastructure Grants Program (EPA, 1997). Mexico authorities would be
responsible for preparing environmental impact analyses for actions in Mexico pursuant to Mexican
laws and authorities. Additional information may become available during public review and after
stakeholder coordination that pertains to transboundary effects and may be included in a later
environmental analysis of the Proposed Action. EPA has relied on reasonably available information
to date to determine transboundary impacts. The environmental review for Supplemental Projects
receiving U.S. funds that are located entirely in Mexico should, at a minimum, include discussion of
effects on the U.S. and should include effects in Mexico as appropriate. The subsequent tiered NEPA
analyses for these projects should re-evaluate transboundary effects as necessary.
1-19
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
2. DESCRIPTION OF ALTERNATIVES CONSIDERED
2.1 Formulation of Alternatives
2.1.1 Identification of Projects to Undergo Feasibility Analysis
EPA's technical evaluation began with the identification of an initial set of 10 projects with potential
to address the public health and environmental concerns caused by transboundary flows into the
U.S. from the Tijuana River and Pacific Ocean. These 10 projects would then undergo the feasibility
analysis summarized in Section 2.1.2 (Project Feasibility Analysis).
Over the past decades, various parties and stakeholders have gathered data and prepared studies to
further characterize the nature and causes of contaminated transboundary flows in the Tijuana
River watershed and propose conceptual solutions. In particular, the following recent key studies
presented project concepts and other data that informed EPA's identification of this initial set of 10
projects:
• NADBank is a binational financial institution established by the U.S. and Mexican
governments to provide financing in support of infrastructure projects and technical
assistance for environmental protection for both countries. NADBank contracted Arcadis to
prepare a Tijuana River Diversion Study (Arcadis, 2019), analyzing various diversion
management capabilities for northbound flows in the Tijuana River watershed. The study
included a transboundary flow analysis, a diagnostic evaluation of diversion infrastructure
and operations, and an assessment of potential infrastructure investment alternatives in
Mexico and the U.S. to address transboundary flows. EPA relied on this study to provide
diagnostic information for diversion infrastructure including the International Collector, the
Tijuana River diversion structure, and pump stations including PB-CILA. This information
was further used to define and evaluate components of several projects to undergo
feasibility analysis.
• USIBWC contracted Stantec to develop a feasibility study (Stantec, 2020a, 2020b) focusing
on sediment basin project concepts in the Tijuana River immediately downstream of the
border. The project concepts regarding river restoration, sedimentation basins, and trash
booms served as the basis for components of one project to undergo feasibility analysis.
• The County of San Diego utilized grant funding under Senate Bill (SB) 507 (enacted by the
State of California) to contract HDR to prepare a Needs and Opportunities Assessment
(HDR, 2020c), which builtupon the Arcadis (Arcadis, 2019) and Stantec (Stantec, 2020a,
2020b) studies to identify U.S.-based project concepts to address transboundary flows into
the Tijuana River Valley. The project concepts in the Needs and Opportunities Assessment
served as the basis for components of two projects to undergo feasibility analysis.
Based on these studies and other available information, EPA identified a set of seven projects and
presented these projects for consideration and discussion via the EPECG in the fall of 2020.
Additionally, during this period, the Scripps Institution of Oceanography released the draft results
of a modeling study that provided additional clarity on the relationship between coastal discharges
of untreated wastewater via SAB Creek at Punta Bandera, Mexico, and the resultant impacts to
beaches in southern San Diego County (Feddersen etal., 2020). EPA also learned of the potential
availability of the City of San Diego-owned SBWRP parcel and facilities as siting options to be
considered for providing additional wastewater treatment capacity. Based on this new information
2-1
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
and stakeholder input, EPA adjusted the scopes of the initial seven project options and identified
three additional project options to be further evaluated.
This process resulted in the following set of 10 projects to undergo feasibility analysis, many of
which include multiple components and sub-projects:
• Project 1: New Tijuana River Diversion System in the U.S. and Treatment in the U.S.
• Project 2: Expand and Upgrade Tijuana River Diversion System in Mexico and Provide
Treatment in the U.S.
• Project 3: Treat Wastewater from the International Collector at the ITP.
• Project 4: Shift Wastewater Treatment of Canyon Flows to U.S. (via Expanded ITP or
SBWRP) to Reduce Flows to the SABTP.
• Project 5: Enhance Mexico Wastewater Collection System to Reduce Flows into the Tijuana
River.
• Project 6: Construct New Infrastructure to Address Trash and Sediment.
• Project 7: Divert or Reuse Treated Wastewater from Existing Wastewater Treatment Plants
in Mexico to Reduce Flows into the Tijuana River.
• Project 8: Upgrade the SABTP to Reduce Untreated Wastewater to Coast.
• Project 9: Treat Wastewater from the International Collector at the SBWRP.
• ProjectlO: Sediment and Trash Source Control.
Fact sheets, maps, and links to the feasibility analysis (with more detailed project descriptions) for
each of these 10 projects are available on EPA's website.3 These 10 projects constituted the
Proposed Action identified in EPA's NOI to prepare an EIS, which initiated the public scoping period
for this PEIS as discussed in Sections 1.5 (Purpose and Scope of the Programmatic EIS) and 7.3.4
(NEPA Public Scoping).
2.1.2 Project Feasibility Analysis
Building on past studies and consultation with stakeholders, EPA evaluated each of the 10 projects
identified in Section 2.1.1 (Identification of Projects to Undergo Feasibility Analysis) for technical,
economic, and environmental feasibility. The feasibility analyses also documented engineering,
regulatory, and implementation issues and presented capital and 40-year life cycle cost estimates.
The results of the feasibility analysis, which EPA documented in a series of 10 memoranda and
related addenda (PG Environmental, 2021a, 2021b, 2021c, 2021d, 2021e, 2021h, 2021 i, 202lj,
2021k, 20211, 2021m), were then used to inform the creation of several alternatives to proceed
through an alternatives analysis, as described in the next section.
3 See https://www.epa.gov/sustainable-water-infrastructure/tijuana-river-watershed-technical-evaluation-
infrastructure.
2-2
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
2.1.3 Alternatives Analysis
After completing the project feasibility analysis, EPA defined a set of alternatives—each consisting
of an assemblage of projects and their individual components and sub-projects—based on
individual project purposes, impacts, environmental benefits, capital costs, and O&M costs. Next,
they were scored using a systematic, replicable, and transparent evaluation tool developed by EPA
called the Augmented Alternatives Analysis. This analysis considered each alternative's feasibility;
cost of construction and O&M; and social, environmental, and economic benefits.
As a result of the alternatives analysis, EPA announced in November 2021 that it had selected the
Comprehensive Infrastructure Solution (Alternative 1-2) to move forward through the NEPA
process. This highest-scoring alternative, while exceeding the budget provided by USMCA
Implementation Act appropriations ($300 million), represents the most comprehensive solution to
both transboundary river wastewater flows and coastal wastewater flows. The alternatives analysis
and scopes of the evaluated alternatives, including the Comprehensive Infrastructure Solution, are
described in more detail in the Water Infrastructure Alternatives Analysis report (PG
Environmental, 202If) and on EPA's website.4
The projects constituting the Comprehensive Infrastructure Solution formed the basis for the
alternatives evaluated in this PEIS, as described in Section 2.2 (Proposed Action and Range of
Alternatives Evaluated in this PEIS).
2.2 Proposed Action and Range of Alternatives Evaluated in This PEIS
EPA's Proposed Action evaluated in this PEIS is the issuance of U.S. appropriations (including but
not limited to USMCA Implementation Act appropriations) for implementation of projects to
address impacts from transboundary flows in the Tijuana River watershed and adjacent coastal
areas. USIBWC's Proposed Action evaluated in this PEIS is the implementation (i.e., design and
construction) of water infrastructure projects funded by EPA in accordance with the strategy
developed5 in this PEIS and selected in the ROD. Because of the programmatic nature of the
decisions to be made, only certain projects would be able to be implemented by USIBWC at the
completion of this NEPA process. Other projects would require additional tiered review before
USIBWC would be able to implement them. Capital costs for project implementation would be
funded through a combination of USMCA Implementation Act appropriations ($300 million);
existing programs such as EPA's Border Water Infrastructure Program (BWIP); additional funds
from Mexico; and (if necessary) additional not-yet-identified federal, state, and/or local
appropriations (see Section 2.8 [Funding Sources and Binational Agreement]).
4 See https://www.epa.gov/sustainable-water-infrastructure/tijuana-river-watershed-technical-evaluation-
infrastructure.
5 EPA would not fund and USIBWC would not implement projects outside their federal jurisdictions, which is
to be determined by binational negotiations.
2-3
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
This PEIS evaluates a No-Action Alternative and two alternatives for implementing the Proposed
Action:
• No-Action Alternative. See Section 2.3. This alternative would not implement the Proposed
Action. NEPA requires that a No-Action Alternative be analyzed to determine the
environmental consequences of not undertaking the Proposed Action, and thereby provides
a baseline against which the potential beneficial and adverse environmental impacts of
action alternatives can be evaluated and compared.
• Alternative 1: Core Projects. See Section 2.4. Under this alternative, EPA would use U.S.
appropriations to fund (and USIBWC would implement) some components of the
Comprehensive Infrastructure Solution that are the responsibility of the U.S., per the terms
of the final cost sharing agreement between the U.S. and Mexico. This approach would fund
and implement only those projects that are sufficiently evolved to be ready for decision
making. The USMCA Implementation Act appropriations and funds from existing programs
such as EPA's BWIP are expected to fund the majority of this scope.
• Alternative 2: Core and Supplemental Projects. See Section 2.5. Under this alternative,
EPA would use U.S. appropriations to fund (and USIBWC would implement) all components
of the Comprehensive Infrastructure Solution that are the responsibility of the U.S., per the
terms of the final cost sharing agreement between the U.S. and Mexico. The USMCA
Implementation Act appropriations and funds from existing programs such as EPA's BWIP
would not be able to fund the majority of this more comprehensive approach, which is
expected to require substantial additional U.S. appropriations. See Section 2.8 (Funding
Sources and Binational Agreement).
Table 2-1 identifies the projects that constitute Alternatives 1 and 2. See Sections 2.4 and 2.5 for
detailed descriptions and figures.
Section 2.7 (Alternatives Eliminated from Evaluation in This PEIS) summarizes additional projects
and alternatives that were considered but eliminated from further analysis in this PEIS.
2-4
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
Table 2-1. Projects Constituting Alternatives 1 and 2
Alternative
Project Title
Project Location
tn
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o
i_
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A. Expanded UP
Option Al: Expand to 40 MGD
Option A2: Expand to 50 MGD
Option A3: Expand to 60 MGD
U.S. only
i—
O
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rH
(D
>
03
Q_
"nj
+-»
c
(D
E
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B. Tijuana Canyon Flows to ITP
Option Bl: Trenching via Smuggler's Gulch and Monument Rd
Option B2: Trenchless Installation via Smuggler's Gulch and Under Mesa
Option B3: Connect to Existing Canyon Collector System
U.S. and Mexico
I—
(D
4->
Q.
3
on
C. Tijuana Sewer Repairs
Mexico only
<
+
(D
D. APTP Phase 1
U.S. and Mexico
O
u
E. APTP Phase 2
U.S. only
r\j
(D
F. U.S.-side River Diversion to APTP
U.S. only
>
G. New SABTP
Mexico only
(D
H. Tijuana WWTP Treated Effluent Reuse
Mexico only
<
1. ITP Treated Effluent Reuse
U.S. and Mexico
J. Trash Boom(s)
U.S. only
2.3 No-Action Alternative
The PEIS must include "No Action" as an alternative to the Proposed Action (40 CFR § 1502.14(c)).
Although the No-Action Alternative does not meet the purpose and need of the Proposed Action, it
is carried forward in this PEIS to provide a means by which to compare the potential environmental
impacts of not proceeding with the Proposed Action to the effects of the other action alternatives.
Thus, under the No-Action Alternative, EPA would not issue USMCA Implementation Act
appropriations and other U.S. appropriations to fund components of the Comprehensive
Infrastructure Solution.
The river diversion and wastewater treatment operations described in Sections 1.2 (Existing
Diversion and Treatment Infrastructure) would continue as-is unless modified through separate,
less-comprehensive projects and funding mechanisms that may prove insufficient to address the
existing and projected deficiencies. The impacts described in Section 1.3 (Causes and Impacts of
Contaminated Transboundary Flows from Tijuana) would persist unabated and would worsen over
time as wastewater infrastructure in Tijuana continues to deteriorate and the population continues
to grow without access to adequate wastewater treatment infrastructure.
The No-Action Alternative would not allow EPA to meet the goals and objectives of the USMCA
Implementation Act Specifically, EPA would not be in compliance with Section 821 of the Act,
which gives authority and direction to the EPA Administrator to "carry out the planning, design,
construction, and operation and maintenance of high priority treatment works in the covered area
to treat wastewater (including stormwater), nonpoint sources of pollution, and related matters
resulting from international transboundary water flows originating in Mexico."
2-5
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
2.4 Alternative 1: Core Projects
For consideration in the environmental review, EPA and USIBWC have developed a solution to
address transboundary flows that consists of four Core Projects identified as Projects A, B, C, and D.
These four projects, in total, constitute Alternative 1 and are analyzed in detail in this PEIS. For the
Core Projects, implementation would also include the mitigation and monitoring measures
described in Section 5 (Mitigation Measures and Performance Monitoring).
Some components of Alternative 1 would take place in Mexico. As described in Section 2.8 (Funding
Sources and Binational Agreement), binational negotiations are underway regarding the scope,
funding, and implementation of projects in Mexico being contemplated as part of the USMCA
Mitigation of Contaminated Transboundary Flows Project EPA and USIBWC would move forward
with funding and/or implementing projects in Mexico only if such projects have support and
funding contributions from appropriate Mexican authorities.
2.4.1 Projects A, B, and C: Improve Collection and Treatment of Wastewater
Alternative 1 includes three Core Projects (Projects A, B, and C) that are intended to improve
collection and treatment of wastewater from Tijuana. Project A involves expanding wastewater
treatment capacity at an existing facility in the U.S. (the ITP). Projects B and C are focused on
modifying and improving wastewater collection systems to ensure that more wastewater is
conveyed to treatment, rather than released directly to the Tijuana River or the Pacific Ocean
without treatment.
2.4.1.1 Project A: Expanded ITP
Project A includes the expansion of the 25-MGD ITP for secondary treatment of wastewater atone
of three different average daily flow capacity options, 40 MGD (Option Al), 50 MGD (Option A2), or
60 MGD (Option A3); construction of a new solids processing facility; installation of other new
supporting facilities; and associated site modifications. The primary purpose of expanding the ITP
is to reduce impacts to the U.S. coast by treating wastewater from the International Collector that
otherwise would be discharged to the Pacific Ocean via SAB Creek without adequate treatment, or
any treatment at all. The expanded ITP may also reduce untreated wastewater overflows from the
sanitary sewer to the Tijuana River caused by mechanical failures at PB1-B. Depending on the
proposed capacity of the plant, the expanded ITP may also provide treatment for sewage collected
in the canyons (Project B), as well as for additional sewage flows produced by the future population
of Tijuana. Project A construction is estimated to be completed by no later than 2027.
The proposed new and expanded facilities and processes for Project A are described below.
Additionally, USIBWC is in the process of initiating a plant-wide condition assessment of existing
ITP components, the results of which could identify additional upgrades necessary to support
expanded operations (e.g., rehabilitation of valves, junction boxes, and piping).
• Preliminary treatment. Upgrades would include replacing and/or installing new raw
wastewater pumps to increase capacity, replacing influent screens at the ITP headworks,
and renovating the existing grit chamber. Renovations to the grit chamber, depending on
final design, could include installation of a more advanced automatic pump sequencing
system, upgrading the grit pumps, and expanding the grit basin itself.
2-6
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
• Primary treatment. Upgrades would include installing new primary clarifiers, contiguous
with and west of the existing primary clarifiers. The new clarifiers would be built to the
same dimensions as the existing ones.
• Secondary treatment. Upgrades would include adding new biological reactors south of the
seven existing reactors; constructing a new, centrally located blower building with new
centrifugal blowers and decommissioning equipment in the existing blower building;
installing new sludge storage tanks immediately west of the two existing sludge storage
tanks; and installing new rectangular secondary sedimentation tanks south of the existing
secondary settling tanks, with new pumps to support operations.
• Discharge. The capacity of the effluent metering pipe would increase, and treated effluent
would continue to be discharged through the SBLO, which then discharges into the SBOO
and then into the Pacific Ocean. Modifications to the wye diffuser array on the SBOO could
be necessary to promote dispersal of the increased loadings (e.g., opening ports on existing
capped risers and/or installing new diffuser heads and ports to existing closed, blind
flanged risers).
• Solids processing. Upgrades would include new equipment to process the increased
amount of solids produced by primary and secondary wastewater treatment. This would
include new dissolved air flotation (DAF) units to thicken sludge from secondary treatment,
new belt filter presses for additional dewatering of waste solids, expansion of the existing
dewatering building to accommodate new equipment, and expansion or replacement of
solids handling facilities. Project A would also incorporate anaerobic digestion of primary
and secondary sludge to substantially reduce the amount of waste solids produced per
gallon of wastewater treated at the ITP. Reducing solids is necessary due to anticipated
logistical challenges with securing enough trucks and drivers to transport sludge offsite for
disposal; however, incorporating anaerobic digestion increases the complexity of plant
operations and necessitates the installation of air pollution control equipment. This could
include, among other controls, installation of an electric generator to combust biogas
emissions and produce electricity to offset a portion of the ITP's energy demand.
• Other improvements. The ITP expansion would include auxiliary facilities to provide
support functions such as office space, a control room, and restrooms. This would involve
constructing at least one new building and/or renovating the existing office building used
by contract staff. Other improvements would include additional roads and parking within
the ITP parcel; new utility connections, such as electrical (including a backup electrical
generator) and communications; and expanded security fencing and lighting around the
ITP.
EPA and USIBWC estimate that the treatment process at the expanded ITP would have similar
removal efficiencies to those of the existing ITP—approximately 96 percent for BOD5,6 68 percent
for total nitrogen, 71 percent for total phosphorus, 97 percent for total suspended solids (TSS), and
99 percent for fecal coliform.
6 BODs is an indicator of the amount of organic pollution in wastewater.
2-7
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
Site modifications would be necessary to accommodate the new and expanded facilities. This would
include providing fill material to create a level foundation for the proposed secondary reactors and
clarifiers, as the areas southwest of Dairy Mart Road are approximately 10 feet lower in elevation
than the rest of the ITP parcel. Fill material would be sourced from elsewhere within the Tijuana
River Valley such as the transboundary sediment deposits in Goat Canyon or Smuggler's Gulch.
Other site modifications would include relocating the portion of Dairy Mart Road that crosses
through the ITP parcel by demolishing it and paving a replacement road along the western
boundary of the ITP parcel, and enclosing or relocating the stormwater swale that runs alongside
this portion of Dairy Mart Road. Construction activities would also potentially involve temporary
work (e.g., material/equipment staging and stormwater management) throughout the undeveloped
25-acre southwest quadrant of the ITP parcel and in portions of the 4-acre parcel northwest of the
ITP.
The infrastructure at the expanded ITP would require regular and ongoing O&M activities to ensure
operational reliability and efficiency. Additional staff members would also be required to
accommodate the anticipated increase in O&M needs. As part an agreement between the U.S. and
Mexico (Treaty Minute No. 283), long-term recurring operations would include hauling of sludge
produced by the treatment process to Mexico for disposal. The pumps and equipment supporting
the ITP would also require regular and ongoing O&M activities such as rehabilitation and
replacement at varying time intervals.
Figure 2-1 provides a schematic of the proposed treatment train at the expanded ITP. Figure 2-2
depicts the anticipated general locations of project elements and construction activities for Project
A. Figure 2-3 provides an example conceptual site plan of the individual facilities that would be
constructed for Project A.
FeCI,
Mixed liquor return
DAF: Dissolved air flotation
FeCI3: Ferric chloride
RAS: Return activated sludge
WAS: Waste activated sludge
Raw
Grit
Screens
wastewater
removal
Advanced
primary settling
Biological
Secondary
reactors
settling
RAS
WAS
Primary sludge
Effluent
to SBOO
DAF
m
Sludge
m
Anaerobic
9
Belt press
H
Solids
thickening
m
storage
mm
digestion
m
dewatering
m
loading
Disposal
Figure 2-1. Project A (Expanded ITP) - Schematic of Expanded ITP Treatment Train
2-8
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
Project A: Expanded UP
[l__|| Construct new/expanded facilities
|[ ll Renovate existing facilities
— — Estimated maximum limit of site improvements
and disturbance
Existing pipelines
International Collector and drain to ITP (approximate)
a *= South Bay Land Outfall (pipeline to SBOO)
POTENTIAL/
STAGING J
i AREA ,
Blower
building
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mm
Stewart's
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handling
Contractor
office building
SAN
DIEGO
BBrrcnpTATiEbj
IMPERIAL
BEACH.
CHULA
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Tijuana
River -
Valley
Figure 2-2. Project A (Expanded ITP) - Locations of Project Components
2-9
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
Project A: Expanded UP
Option A1 (40 MGD) footprint
Option A2 (50 MGD) additional footprint
Option A3 (60 MGD) additional footprint
Approximate area requiring fill
111 II Other new structures
New parking
j^itliia'juana^r
Auxiliary facilities
(offices, labs, etc.)
New blower
building
New and
relocated
generators
Secondary
clarifiers
Primary
clarifiers
Secondary
reactors
units
Anaerobic
digesters
Sludge
dewatering
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storage
tanks
SAN
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River -
Valley
Figure 2-3. Project A (Expanded ITP) - Conceptual Site Plan of Proposed Facilities
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
Project A includes three proposed average daily flow capacity options for the proposed ITP
expansion from the current 25-MGD capacity: Options Al, A2, and A3. The differences between the
three options are summarized below and in Table 2-2.
• Option Al: Expand to 40 MGD. Expanding the ITP to a design treatment capacity of 40
MGD (average daily flow) would enable the plant to treat all wastewater in the International
Collector and wastewater that would be collected by the rehabilitated sewer collectors in
Tijuana (see Project C). However, the 40-MGD option would have minimal if any reserve
capacity for future population growth.
• Option A2: Expand to 50 MGD. Expanding the ITP to a design treatment capacity of 50
MGD (average daily flow) would provide the same treatment capabilities as the 40-MGD
option (see Option Al) while also accommodating wastewater collected in the canyons in
Mexico (see Project B) and providing capacity for current and projected wastewater flows
through 2030.
• Option A3: Expand to 60 MGD. Expanding the ITP to a design treatment capacity of 60
MGD (average daily flow) would provide the same treatment capabilities as the 50-MGD
option (see Option A2) while providing capacity for current and projected wastewater flows
through 2050.
The estimated capital costs for each option are shown in Table 2-2. In addition to capital costs for
construction, operation of the expanded ITP would require additional recurring O&M funds. Annual
O&M is funded through appropriations to USIBWC. For an expanded ITP, USIBWC would request
additional resources needed for increased O&M activities as part of its annual request to the Office
of Management and Budget through the Department of State.
Table 2-2. Comparison of Project A Options
Componenta
Option Al
Option A2
Option A3
ITP treatment capacity (average daily flow)
40 MGD
50 MGD
60 MGD
ITP treatment capacity (peak daily flow)
100 MGD
100 MGD
100 MGD
New primary clarifiers (#)
5
8
8
New secondary reactors (#)
5
7
10
New centrifugal blowers (#)
5
5
6
New secondary clarifiers (#)
7
12
12
New DAF units (#)
4
5
6
New anaerobic digestors (#)
5
6
6
New sludge storage tanks (#)
2
2
3
New facility footprint, total (approximate)
400,000 SF
475,000 SF
530,000 SF
New ITP employees (#)
30
40
50
Estimated capital cost for construction b c
$227 million
$299 million
$372 million
a - All scope estimates presented in this PEIS are based on feasibility-level engineering and are subject to
refinement during the design process.
b - Cost estimates do not include renovations to the existing grit chambers and solids handling facilities,
c-All cost estimates were developed with an estimated accuracy of +50%/-25% for U.S.-side projects and +100%/-
50% for Mexico-side projects. See Section B.7 of the Water Infrastructure Alternatives Analysis (PG Environmental,
2021f) for more information on how the cost estimates were developed.
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
2.4.1.2 Project B: Tijuana Canyon Flows to ITP
Project B includes the installation of a wastewater conveyance system from Matadero Canyon and
Los Laureles Canyon in Mexico to the expanded ITP for treatment (see Project A for details on the
ITP expansion) and associated temporary construction activities. Following treatment, these flows
would be discharged to the Pacific Ocean through the SBLO/SBOO as described for Project A. Three
configurations and/or installation methods of the conveyance line are being considered: trenching
through Smuggler's Gulch and Monument Rd (Project Bl), trenchless installation in Smuggler's
Gulch and under the mesa (Project B2), and connection to the existing canyon collector system
(Project B3). The primary purpose of the proposed conveyance system is to reduce the amount of
dry-weather wastewater flows that are currently discharged with little to no treatment to the
Pacific Ocean via SAB Creek. As a secondary benefit, Project B would potentially reduce the volume
and frequency of dry-weather transboundary flows in Goat Canyon and Smuggler's Gulch by
eliminating the reliance on pump stations whose mechanical issues may cause occasional
wastewater overflows into the canyons in Mexico (see Section 1.3 [Causes and Impacts of
Contaminated Transboundary Flows from Tijuana]).
Up to 12.7 MGD (peak daily) of wastewater from the canyons would be collected by the new
conveyances and transported to the ITP for treatment. The current wastewater flow from the
canyons is 6.3 MGD, so the new conveyances would have available capacity to accommodate flow
increases over time.
The new wastewater conveyance system would include new pipelines (Reaches 1-4) in Mexico that
use gravity to convey wastewater to the U.S., which would eliminate reliance on the existing pump
stations in the canyons—specifically, the Matadero pump station in Matadero Canyon and the Los
Laureles 1 and Los Laureles 2 pump stations in Los Laureles Canyon.7 The new Reach 5 pipeline in
the U.S. is described later in this section. The new conveyance lines in Mexico would consist of the
following:
• Reach 1: A 15-inch nominal diameter gravity sewer that would flow directly east from the
Los Laureles 2 pump station and connect to Reach 2. Reach 1 would be approximately 2,000
feet long, would pass underneath the high ground between the two canyons, and would be
installed using directional drilling.
• Reach 2: A 15-inch nominal diameter gravity sewer that would flow generally north from
the eastern end of Reach 1 to the Matadero pump station. Reach 2 would be approximately
1,700 feet long and would be installed using conventional open-cut trenching methods.
• Reach 3: A 21-inch nominal diameter gravity sewer that would flow generally north along
Matadero Canyon from the Matadero pump station until it intersects Reach 4 approximately
150 feet south of the border. Reach 3 would be about 3,500 feet long and would be installed
using conventional open-cut trenching methods (except for approximately 700 feet passing
beneath the International Highway, which would be installed using micro-tunneling).
• Reach 4: A 15-inch nominal diameter gravity sewer that would flow generally east from the
Los Laureles 1 pump station until it intersects with Reach 3. Reach 4 would be
7 These three pump stations would remain in place as backup to pump flows from the canyons to SABTP or
SAB Creek in the unlikely case of failure of a Project B pipeline in the U.S.
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
approximately 4,000 feet long, would pass beneath the high ground between the canyons,
and would be installed using directional drilling.
The sections of the proposed conveyance line that would be installed using open-cut trenching
(Reach 2 and a part of Reach 3) would occur in undeveloped areas in Matadero Canyon and would
require temporary land disturbance and lighting along the proposed route during construction, as
well as for staging areas. The sections of the proposed conveyance line that would be installed using
micro-tunnelling or directional drilling (Reach 1, 4, and part of Reach 3) would require temporary
pits at each end of the micro-tunnel or drilling location with construction staging areas to feed the
pipe sections underground. The construction areas on each side of the micro-tunnel or drilling
operation would require temporary fencing, lighting, a truck-mounted generator to run equipment,
and other construction equipment. The pipes would have shallow installation, so dirt would be
backfilled following installation.
In the U.S., Project B includes three proposed configurations of Reach 5 to convey flows from the
end of Reach 4 to the expanded ITP: Options Bl, B2, and B3. The differences between the three
options are summarized below.
• Reach 5, Option Bl: Trenching via Smuggler's Gulch and Monument Road. Option Bl
includes installing Reach 5 using open-cut trenching methods through Smuggler's Gulch and
along Monument Road. Reach 5 would consist of a 24-inch nominal diameter force main
that would run from 150 feet south of the border in Matadero Canyon to the headworks of
the ITP. This sewer would run north beneath the border for approximately 1,000 feet; north
under the Smuggler's Gulch access road for approximately 1,300 feet; east under Monument
Road for approximately 6,100 feet; and east/southeast adjacent to Clearwater Way and
WestTia Juana Street for approximately 3,600 feet before reaching the headworks of the
ITP.
Reach 5 would be installed using conventional open-cut trenching methods except for the
section beneath the U.S.-Mexico border, which would be installed using micro-tunneling.
Temporary pits would be required at each end of the micro-tunnel section and may require
additional security during construction due to their proximity to the border. Depending on
the results of utility surveys, open-cut trenching would be confined to the existing roadway
in Smuggler's Gulch and along Monument Road and would be confined to the undeveloped
strip of land adjacent to Clearwater Way and WestTia Juana Street. Unvegetated areas
would be used for construction staging activities, as necessary.
• Reach 5, Option B2: Trenchless Installation via Smuggler's Gulch and Under Mesa.
Option B2 includes installing Reach 5 using a combination of open-cut trenching and
trenchless methods to avoid or minimize disturbances within Smuggler's Gulch and along
Monument Road. Reach 5 would be a 24-inch nominal diameter polyvinyl chloride (PVC)
force main that starts 150 feet south of the border and runs approximately 1,000 feet north
into Smuggler's Gulch; east underneath the mesa for approximately 5,000 feet; and
east/southeast along Dairy Mart Road, Clearwater Way, and West Tia Juana Street for
approximately 4,500 feet before reaching the headworks of the ITP.
The sections of Reach 5 underneath the border, Smuggler's Gulch, and the mesa between
Smuggler's Gulch and the ITP would be installed using directional drilling. These sections
would require three temporary pits: one located 150 feet south of border in Smuggler's
Gulch, one located approximately 900 feet north of the border in Smuggler's Gulch (adjacent
to the canyon flow diversion structure), and one located near the intersection of Dairy Mart
Road and Monument Road. The temporary construction pits in Smuggler's Gulch may
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
require additional security during construction due to their proximity to the border. Open-
cut trenching would be used for the final section to the ITP headworks (identical to that for
Option Bl).
• Reach 5, Option B3: Connect to Existing Canyon Collector System. Option B3 includes
installation of Reach 5 beneath the border to connect to the existing canyon collector
pipeline in Smuggler's Gulch (part of the existing canyon collector system described in
Section 1.2 [Existing Diversion and Treatment Infrastructure]) for conveyance to the ITP.
This option would minimize disturbances and leverage existing infrastructure. Reach 5
would be a 24-inch nominal diameter high-density polyethylene (HDPE) gravity pipe that
runs north beneath the border for approximately 1,000 feet and connects to the existing 30-
inch gravity sewer ("canyon collector") that currently conveys flows from the Smuggler's
Gulch canyon flow diversion structure to the Hollister Street pump station. The existing
equipment at the pump station would be used to pump these combined flows (from Reach 5
and the U.S.-side canyon flow diversion structures) to the ITP using the existing 16-inch and
30-inch force mains.8
Reach 5 would be installed using micro-tunnelling underneath the border. The U.S.-side
micro-tunnelling pit would also be used to connect Reach 5 to the existing canyon collector.
Temporary pits would be required at each end of the micro-tunnel section and may require
additional security during construction due to their proximity to the border.
The estimated capital costs for Project B are $30.8 million, $44.7 million, and $22.3 million for
Options Bl, B2, and B3, respectively. Project B construction activities, including components in
Mexico, are projected to take approximately two years to complete following mobilization but the
specific schedule for starting and completing construction is not known at this time.
The infrastructure proposed for Project B would be expected to require regular and ongoing O&M
activities to ensure operational reliability and efficiency. Maintenance on the U.S. side would
generally consist of inspecting the ground along the sections of pipe installed using open-cut
trenching to look for potential leaks. The new conveyance pipelines would use gravity to transport
wastewater; therefore, minimal mechanics would be involved, reducing the overall maintenance
requirements. Maintenance of the new gravity pipelines in Mexico would generally consist of
routine CCTV inspections, cleaning, and leak repairs. Binational negotiations regarding O&M
responsibilities and funding for Project B are ongoing.
Figure 2-4, Figure 2-5, and Figure 2-6 depict the anticipated general locations of project elements
and construction activities for Options Bl, B2, and B3, respectively, of Project B.
8 Depending on the results of the USIBWC condition assessment of existing ITP components, the scope of
Option B3 could also include rehabilitation of the Hollister Street pump station and associated force mains.
However, this PEIS does not evaluate impacts of extensive rehabilitation of the force mains (e.g., impacts of
open-trench rehabilitation or replacement of the force mains). If EPA and USIBWC select Option B3 and
determine that extensive rehabilitation of the force mains is necessary, resulting in impacts that could be
significant and that are not documented in this PEIS, this would require a supplemental NEPA review (and
associated public engagement) to assess impacts to the properties that would be affected by rehabilitation
activities.
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
Mdnump,
S^rAr-H|5g
loBTjlONlBll
Los Laureles 1-
pump^tation
pump station
Project B: Tijuana Canyon Flows to UP k»
* I Decommission existing pump stations
0s &
r ' — » install pipeline (via trenchless methods) j
§
h ' Install pipeline (via open-cut trenching) J,;,
* ' ¦*' '
¦ Los Laureles 2
v- • '
pump station
mmM&u. m .
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Tijuana
River -
Valley
0 500 1,000 1,500 2,000 2,500
TIJUANA
Figure 2-4. Project B (Tijuana Canyon Flows to ITP), Option B1 - Locations of Project Components
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
Mdnump,
MEXICO V ,
tB Vd u fx+M* 9
Los Laureles^!-
pump station
Matadero
pump station
l°±L
Project B: Tijuana Canyon Flows to UP
H Decommission existing pump stations
1 — » Install pipeline (via trenchless methods)
¦ Install pipeline (via open-cut trenching)
jtggf' f •>-*«
¦ Los Laureles 2
v- • '
pump station
m .
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Tijuana
River -
Valley
0 500 1,000 1,500 2,000 2,500
TIJUANA
Figure 2-5. Project B (Tijuana Canyon Flows to ITP), Option B2 - Locations of Project Components
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
mSoTTm,
Hollister St
pump station
, - a*er Way/iv
[CpTEDlST^Lt^
" .'MEXICO' ,'
pump station -
Matadero
pump station
Project B: Tijuana Canyon Flows to UP
| Decommission existing pump stations
1 — » Install pipeline (via trenchless methods)
1 Install pipeline (via open-cut trenching)
— — Convey flow via existing canyon collector pipeline
- *
. ¦
rpump station
Eni iii rfi i im—¦
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Tijuana
River -
Valley
0 500 1,000 1,500 2,000 2,500
TIJUANA
Figure 2-6. Project B (Tijuana Canyon Flows to ITP), Option B3 - Locations of Project Components
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
2.4.1.3 Project C: Tijuana Sewer Repairs
Project C includes rehabilitating or replacing targeted sewer collectors in the Tijuana metropolitan
area in order to reduce the amount of untreated wastewater that currently leaks from the sanitary
sewer system in Tijuana and enters the Tijuana River. By reducing wastewater leaks to the river in
Tijuana, Project C would improve downstream water quality in the Tijuana River Valley and
Estuary by both 1) reducing overall river flow volumes, and thus reducing the frequency of dry-
weather transboundary flows caused by river flow rates that exceed the PB-CILA diversion
capacity, and 2) ensuring that more wastewater in the Tijuana sewer system is successfully
conveyed to the expanded ITP for treatment (see Project A) rather than entering the U.S. as a
transboundary flow.
CESPT and CONAGUA, with concurrence from EPA and USIBWC, have identified seven sewer
collectors to be rehabilitated or replaced using USMCA, BWIP, and/or Mexico funds as a Core
Project under this PEIS. Most of the improvements would include replacement of old concrete pipes
with new pipes made from more durable material (e.g., PVC or HDPE) to prevent the risk of leaks
and collapses. Most of these collector rehabilitation and replacement projects, listed in Table 2-3,
were selected with the goal of reducing existing wastewater leaks to the Tijuana River down to 5
MGD.9 One project (Force Main Antiguo, project #7) was selected with the goal of reducing
transboundary wastewater leaks that reach the U.S. and the Tijuana River via Los Laureles Canyon
and Matadero Canyon. Figure 2-7 depicts a schematic of the wastewater collection system in
Tijuana and the project locations.
Construction activities for rehabilitation or replacement of these sewer collectors would include the
use of heavy construction equipment and open-cut trenching in most locations. In some cases (e.g.,
when sections of pipelines are particularly deep or would cross busy roadways), trenchless
methods would be used. The targeted sewers are located in urban, developed areas predominantly
within existing streets.
The estimated capital costs are $59 million for the targeted collector repairs. Project C construction
activities are projected to take approximately one to three years to complete (per individual
project) following mobilization but the specific schedule for starting and completing construction
for all collector repairs is not known at this time. See Section 2.8 (Funding Sources and Binational
Agreement) for more information about funding sources and O&M responsibilities for this project
The sewer collector repair projects listed in Table 2-3 include current projects having priority for
rehabilitation or repairs. While Mexico has the prerogative to modify the list to prioritize other
repair projects, any such modifications to the list of projects would preserve the overall goal of
reducing existing wastewater leaks to the Tijuana River down to 5 MGD. This would ensure that the
transboundary impacts and improvements are similar to those of the projects listed in Table 2-3.
9 In addition to the projects identified in Table 2-2, EPA is planning to provide BWIP funding for separate
efforts (pursuant to separate NEPA reviews) that also would perform priority repairs to sewer infrastructure
in Tijuana. See Section 2.9 (Related Projects).
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
Table 2-3. Tijuana Sewer Collectors Included in Project C for Rehabilitation or Replacement
ID
Number
Name
Description
Length to Be
Rehabilitated (feet)
Existing Pipe
Proposed Pipe
Projects to Reduce Wastewater Leaks to Tijuana River in Mexico
1
International Collector
(Phase 2)a
Rehabilitate International Collector piping using
trenchless methods due to location along a major
highway.
8,200
72-inch concrete
72-inch PVCSPR
(PVC spiral inside
concrete pipe)
2
Rehabilitation of Insurgentes
Collector
Replace Insurgentes Collector piping.
18,400
36-inch concrete
36-inch PVC
3
Rehabilitation of Poniente
Collector (missing sections in
col. 20 de Noviembre)
Rehabilitate Poniente Interceptor pipeline, which is
old, at risk of collapse, and causes major spills and
wastewater discharges to the Tijuana River.
2,300
42-inch concrete
42-inch and 48-
inch PVC
4
Rehabilitation of Collector
Carranza
Replace Carranza Collector piping in Colonia Carranza.
9,200
36-inch concrete
36-inch PVC
5
Rehabilitation of Interceptor
Replace the Oriente Collector in the eastern section of
22,800
42- and 48-inch
42-inch and 48-
Oriente
the Tijuana River.
concrete
inch PVC
6
Tijuana River Gates
Replace piping along the Alamar and Tijuana River
wastewater collection system to reduce untreated
wastewater discharges to the Tijuana River.
23,300
8- to 60-inch
concrete
8-inch to 60-inch
PVC
Project to Reduce Wastewater Leaks to Los Laureles Canyon and Matadero Canyon in Mexico
7
Force Main Antiguo
Rehabilitate the force main section of the old
conveyance from PB1 to SABTP.
14,400
42-inch steel core
concrete
42-inch steel or
PVC pipe
a - Phase 1 of the International Collector repairs, which includes construction of new alternative piping through the streets of Tijuana using 60-inch PVC, is
being funded through BWIP and received a Categorical Exclusion in March 2022 to complete its NEPA review.
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
Segments of the wastewater collection system shown in red are those in need of repair.
Rodriguez Dam
Impoundment
Sewer collector repair ID numbers and approximate locations are indicated in yellow. Note that
collector repair ID #6 (Tijuana River Gates) consists of repairs in multiple locations along the
Alamar and Tijuana Rivers and is therefore not included in the figure.
SABTP
Figure 2-7. Project C (Tijuana Sewer Repairs) - Schematic of Tijuana Sewer Collectors for Rehabilitation or Replacement
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
2.4.2 Project D: APTP Phase 1
Project D includes the construction and operation of a 35-MGD Advanced Primary Treatment Plant
(APTP) for advanced primary treatment of diverted water from the existing PB-CILA diversion in
Mexico, rehabilitation and extension of the existing force main from PB-CILA to the new APTP,
installation of other new supporting facilities, and associated site modifications. The primary
purpose of Phase 1 of the proposed APTP is to reduce impacts to the U.S. coast by treating diverted
river water that otherwise would be discharged to the Pacific Ocean via SAB Creek without
adequate treatment, or any treatment at all. This project would also reduce the frequency of
transboundary river flows by eliminating the use of a pump station (PB1-A) whose mechanical
issues indirectly cause occasional shutdowns of the PB-CILA diversion (see Section 1.2 [Existing
Diversion and Treatment Infrastructure]).
The APTP would operate independently of the existing ITP and would consist of the following
treatment processes: screening, aerated grit removal, grit dewatering, a ballasted flocculation
process, and sludge handling. Figure 2-8 provides a schematic of the treatment train at the
proposed APTP.
River
Water
Screens
Grit
Removal
Ballasted
Flocculation
Primary Sludge
1
Gravity
¦¦
Sludge
Belt Press
Solids
Thickening
~
Storage
Dewatering
Loading
Effluent
to SBOO
Disposal
Figure 2-8. Project D (APTP Phase 1)-Schematic of APTP Treatment Train
The proposed 35-MGD APTP for Project D, which represents Phase 1, would be designed and
constructed to allow for potential expansion under Phase 2. For example, concrete pads
constructed under Phase 1 for ballasted flocculation, sludge storage, and other process units would
be large enough to accommodate the potential installation of additional process units under Phase
2, and piping and stub-outs to convey flows between the units would be sized to accommodate the
flow rates of a 60-MGD plant. While these expanded pads would not specifically support operation
of the 35-MGD plant, this approach is necessary to ensure soil and foundation stability for the
overall plant and to ensure that the siting of Phase 1 infrastructure does not inadvertently prevent
potential future expansion under Phase 2. See Section 2.5.2.1 (Project E: APTP Phase 2) for
additional information on the proposed Phase 2.
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
The proposed new facilities and processes for Project D are described below.
• Preliminary treatment. The preliminary treatment process would include conveying
influent from the headworks through self-cleaning bar screens and an aerated grit removal
tank. The screening process would protect the advanced primary treatment process from
large solid waste, and the grit chambers would remove approximately 25 percent of the
suspended solids from river water.
• Primary treatment. The APTP would include a ballasted flocculation treatment process.
Ballasted flocculation is a physical chemical treatment process that uses recycled media,
coagulants, and polymers to improve the settling properties of suspended solids. Two
ballasted flocculation treatment trains would be constructed, each with a 25-MGD design
capacity. A flow schematic of the ballasted flocculation process is shown in Figure 2-9.
• Discharge. Treated effluent from the ballasted flocculation process would be conveyed
through a new 300-foot pipeline located within the ITP parcel to tie into the existing ITP
effluent structure and then discharged through the SBLO, which then discharges into the
SBOO and then into the Pacific Ocean. Modifications to the wye diffuser array on the SBOO
could be necessary to promote dispersal of the increased loadings (e.g., opening ports on
existing capped risers and/or installing new diffuser heads and ports to existing closed,
blind flanged risers).
• Solids processing. The APTP would include solids handling facilities to process the grit and
sludge removed from the river water. The sludge handling process would include gravity
thickening, sludge storage, and dewatering units. The sludge loading facilities would include
conveyors and hoppers to load the sludge onto trucks to be hauled offsite for disposal.
• Other improvements. The new APTP would include facilities for offices, a control room,
and restrooms to support operations. These facilities would potentially be co-located with
similar proposed support facilities at the expanded ITP (Project A). The existing blower
building at the ITP would be repurposed to house the controls for the APTP process.
Electrical upgrades to the current system, including additional backup power, would
support the pumps and equipment for the proposed APTP. The APTP site is enclosed by the
existing ITP fence, but additional or upgraded lighting would potentially be required.
EPA and USIBWC estimate that the treatment process at the APTP would have removal efficiencies
of approximately 50 percent for BODs, 13 percent for total nitrogen, 85 percent for total
phosphorus, 89 percent for TSS, and 95 percent for fecal coliform.
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
Hydrocyclone
Sludge Handling Ifci
*—¥
Polymer '
Coagulant
Influent Water from
Grit Chamber
Microsand and Sludge to Hydrocyclone
Microsand
Clarified Water
Cxjx]
Cxixi
0=0
t
>o<]
Injection Maturation
1
Inclined Plate Settler with
Scraper
Source: (EPA, 2003).
Figure 2-9. Ballasted Flocculation Process Flow Schematic
Site modifications for the proposed APTP would be necessary and would include grading and land
disturbance for siting of the proposed APTP (shown in Figure 2-10) on the northern edge of the ITP
property and for construction staging areas within the ITP parcel. The proposed APTP would be
constructed in the north area of the ITP parcel, immediately north of the ITP secondary treatment
units and south of WestTia Juana Street Construction activities would also potentially involve
temporary work (e.g., material/equipment staging and stormwater management) throughout the
undeveloped 25-acre southwest quadrant of the ITP parcel.
In order to convey river water to the new APTP, the existing PB-CILA diversion in Mexico (which
would operate when the instantaneous river flow rate is 35 MGD or less) would convey diverted
river flows through an existing force main across the border to the APTP headworks. Project D
would include the rehabilitation and extension of this existing force main from PB-CILA in Mexico
to the new APTP in the U.S. PB-CILA currently conveys diverted river water to PB1-A through a 42-
inch force main. This line would be rehabilitated and extended to direct flows from PB-CILA to the
headworks of the new APTP, thus bypassing PB1-A. The section of the line proposed for
rehabilitation runs from PB-CILA to Avenue M in Tijuana and is approximately 7,200 feet long.
Rehabilitation of this section of existing pipe would involve installing mechanical joint restraints
and applying corrosion protection. A new section of 42-inch HDPE force main, approximately 800
feet in total length, would be installed (using micro-tunneling) under the border from the PB1-A
site in Mexico to a location west of Stewart's Drain on ITP property in the U.S. Finally, open-cut
trenching in the U.S. would be used to construct an approximately 1,800-foot section of new 42-
inch HDPE force main north to West Tia Juana Street and then to the headworks of the new APTP.
Rehabilitating and extending the existing force main line would involve temporary land disturbance
during construction in both Tijuana and in the U.S. within the ITP parcel. In Tijuana, temporary
pumps would re-route flow between PB-CILA and PB1-A while this portion of the force main is
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
rehabilitated, and temporary fencing and lighting would be constructed to increase security and
support operations. Micro-tunneling under the U.S.-Mexico border would require temporary pits at
both ends, and open-cut trenching would involve land disturbance and additional lighting. A
temporary shutdown of PB-CILA or bypass of the force main (e.g., by sending diverted river flows to
the International Collector) would be necessary to allow for connection of the rehabilitated and
new force main sections.
The proposed APTP would require regular and ongoing O&M activities to ensure operational
reliability and efficiency. Approximately 30 additional staff members would be required to
accommodate the anticipated increase in O&M needs. Long-term recurring operations would
include hauling of solids produced by the treatment process to a local solid waste disposal site. The
pumps and equipment supporting the APTP would also require regular and ongoing O&M activities
such as rehabilitation and replacement at varying time intervals.
The estimated capital costs are $76.6 million for the 35-MGD APTP and $11.5 million for the force
main rehabilitation and extension. Project D construction activities, including components in
Mexico, are projected to take approximately two years to complete following mobilization but the
specific schedule for starting and completing construction is not known at this time. Binational
negotiations regarding O&M responsibilities and funding for Project D are ongoing.
Figure 2-10 and Figure 2-11 depict the anticipated general locations of project elements and
construction activities for Project D. Figure 2-12 provides an example conceptual site plan of the
individual facilities that would be constructed for Project D.
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
Project D: APTP Phase 1
inn Construct primary treatment and sludge handling facilities
IW1 Construct auxiliary facilities
EZ3 Renovate existing blower building
' 1 1 ' Rehabilitate existing pipeline from PB-CILA
1 Install force main to APTP
«=¦ ¦=« Install treated effluent pipeline
Existing pipelines
•=• «= South Bay Land Outfall (pipeline to SBOO)
SOUTH BAY
¦¦WATER
IkecuA'wiation
fcsmaij
BBSQUJjH.BAY.
jlNiTjE RNA ' [WNADI
¦^VIewati'e'kiI
llTREAT^ENTill
Stewart's
Drain
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Tijuana
River -
Valley
Figure 2-10. Project D (APTP Phase 1) - Locations of Project Components (1 of 2)
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
Project D: APTP Phase 1
Construct primary treatment and sludge handling facilities
IW1 Construct auxiliary facilities
EZ3 Renovate existing blower building
' 1 1 ' Rehabilitate existing pipeline from PB-CILA
1 Install force main to APTP
«=¦ ¦=» Install treated effluent pipeline
^a7fflrfo?Se?iafPtl aTa]
River
diversion
¦DOWNTOWN'
^TjuanaI
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Tijuana
River -
Valley
TIJUANA
Figure 2-11. Project D (APTP Phase 1) - Locations of Project Components (2 of 2)
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
Project D: APTP Phase 1
II I 11 New process units
yjjj Other new structures
• Install force main to APTP
a 0 Install treated effluent pipeline
Sludge
loading
Sludge
dewatering
Sludge
thickening
Headworks
structure and
screening
Ballasted
flocculation
Grit
removal
!¦¦¦¦»: h 1
HKfllBBil A:
Auxiliary facilities
(offices, labs, etc.)
Conveyor
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Tijuana
River -
Valley
Figure 2-12. Project D (APTP Phase 1) - Conceptual Site Plan of Proposed Facilities
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
2.5 Alternative 2: Core and Supplemental Projects
For consideration in the environmental review, EPA and USIBWC have developed a comprehensive
solution to address transboundary flows which consists of the four Core Projects described above
and six Supplemental Projects that would also meet EPA's purpose and need for action. These 10
projects, in total, constitute Alternative 2 and the full scope of the Comprehensive Infrastructure
Solution that EPA and USIBWC identified through the process described in Section 2.1 (Formulation
of Alternatives).
As with Alternative 1, some components of Alternative 2 would take place in Mexico. As described
in Section 2.8 (Funding Sources and Binational Agreement), binational negotiations are underway
regarding the scope, funding, and implementation of projects in Mexico being contemplated as part
of the USMCA Mitigation of Contaminated Transboundary Flows Project EPA and USIBWC would
move forward with funding and/or implementing projects in Mexico only if such projects have
support and funding contributions from appropriate Mexican authorities. For all projects in
Alternative 2, implementation would also include the mitigation and monitoring measures
described in Section 5 (Mitigation Measures and Performance Monitoring).
2.5.1 Core Projects
Alternative 2 includes the four Core Projects (Projects A, B, C, and D) considered as part of
Alternative 1 that are described in Section 2.4 (Alternative 1: Core Projects). Alternative 2 does not
include any changes to the Core Projects.
2.5.2 Supplemental Projects
In addition to the Core Projects, Alternative 2 includes six Supplemental Projects (Projects E, F, G, H,
I, and J) that are intended to provide a more comprehensive solution for reducing contaminated
transboundary flows. The Supplemental Projects are still early in their planning phase and are not
yet ready for detailed environmental review for the following reasons:
• Further studies and/or federal and binational coordination are needed to refine the scopes
(including construction and long-term O&M) of the Supplemental Projects, which will allow
for a meaningful review and consideration of each project's potential impacts.
• The need for certain components of the Supplemental Projects is still being assessed and
may be dependent on the effectiveness of other recent and proposed upgrades.
• Complex and significant environmental impacts that could require intensive analyses,
studies, and consultations could delay Core Projects that are further along in the planning
process.
Therefore, these Supplemental Projects are included in this PEIS at a programmatic level and are
intended to be analyzed further in subsequent tiered NEPA analyses. See Section 1.5 (Purpose and
Scope of the Programmatic EIS).
The timing to begin and complete construction for Supplemental Projects is unknown at this time.
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
2.5.2.1 Project E: APTP Phase 2
Project E includes the expansion of the 35-MGD APTP (Phase 1; see Project D) to an average daily
flow capacity of up to 60-MGD capacity (Phase 2). As described in Section 2.4.2 (Project D: APTP
Phase 1), Phase 1 would include the design and construction of concrete pads for both phases to
ensure soil and foundation stability for the overall plant These pads would be large enough to
accommodate Phase 2 process units, and piping and stub-outs between the treatment units would
be sized to accommodate the flow rates of a 60-MGD plant Depending on operating conditions at
the existing 35-MGD PB-CILA river diversion in Mexico, the expanded APTP would treat river water
from PB-CILA (during dry-weather flows) and/or a new river diversion farther downstream in the
U.S. (see Project F). The primary purpose of Phase 2 of the proposed APTP is to reduce downstream
impacts in the Tijuana River and Estuary by providing additional capacity to treat contaminated
river water.
Project E would include installing additional facilities and equipment (bar screens, grit removal,
ballasted flocculation units, sludge storage units, screens, and belt filter presses) to expand the
capacity of the treatment train illustrated in Figure 2-8 and Figure 2-9. New units would be
installed between and immediately adjacent to units constructed under Phase 1 (see Figure 2-12).
Treated effluent from the APTP would continue to be discharged through the SBLO/SBOO to the
Pacific Ocean, though modifications to the wye diffuser array on the SBOO could be necessary to
promote dispersal of the increased loadings (e.g., opening ports on existing capped risers and/or
installing new diffuser heads and ports to existing closed, blind flanged risers). Some minor interior
modifications to the APTP would potentially be required.
Concrete work, earthwork, and mobilization of construction equipment would be minimal, and the
majority of construction activities would take place within the APTP facility and immediately
adjacent areas.
The expanded APTP would require regular and ongoing O&M activities to ensure operational
reliability and efficiency, similar to those required for Phase 1. However, the expanded APTP would
produce more solids than Phase 1, resulting in greater long-term recurring truck hauling needs for
disposal. Up to approximately 20 additional staff members would be required to accommodate the
anticipated increase in O&M needs. Binational negotiations regarding O&M responsibilities and
funding for Project E are ongoing.
Figure 2-13 depicts the anticipated general locations of project elements and construction activities
for Project E.
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
mum MnJ
jMWi. ''
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
2.5.2.2 Project F: U.S.-side River Diversion to APTP
Project F includes construction of a U.S.-side diversion system in the Tijuana River to convey
transboundary river flows10 to the APTP for treatment. The primary purpose of Project F is to
improve water quality in the Tijuana River Valley, the Tijuana River Estuary, and coastal
communities in southern San Diego County by diverting transboundary river flows from the
Tijuana River in the U.S. The capacity and operation of the river diversion, and thus the degree and
extent of downstream water quality improvements, would depend on the capacity of the APTP that
receives and treats the diverted flows. Specifically:
• If the U.S.-side river diversion is designed to divert 35 MGD to a 35-MGD APTP (Project D,
i.e., Phase 1), the system would divert primarily dry-weather transboundary river flows
(e.g., those that occur due to a PB-CILA diversion system shutdown in Mexico or a release
via Stewart's Drain) and a portion of smaller wet-weather11 transboundary river flows.
• If the U.S.-side river diversion is designed to divert 60 MGD to a 60-MGD APTP (Project E,
i.e., Phase 2), the system would be capable of operating more frequently and diverting a
larger portion of wet-weather transboundary river flows in addition to dry-weather flows.
The U.S.-side Tijuana River diversion would not operate during all wet-weather flow conditions to
reduce the risk of system damage and avoid unnecessary O&M expenditures that do not result in
significant environmental benefit. The 35-MGD diversion would shut off when the instantaneous
flow rate exceeds approximately 60 MGD, and the 60-MGD diversion would shut off when the
instantaneous flow rate exceeds approximately 120 MGD.1213
While potential alternative locations for the diversion structure have not been identified, it would
be located within the "area under consideration" that extends approximately 8,300 feet
downstream of the U.S.-Mexico border as shown on Figure 2-13. Identifying an optimal location and
design concept for the diversion structure requires additional engineering, hydrological, and
environmental analyses and interagency consultation and coordination. The location and design
should appropriately consider various performance and impact factors, which include but are not
limited to the following:
• The ability to reliably intercept transboundary flows from a river channel whose position
downstream of the energy dissipator is known to shift and bifurcate.
10 While Project F would not prevent river flows from entering the U.S., it would divert at least a portion of
these river flows immediately downstream of the border for treatment and thus reduce contaminated flows
affecting the Tijuana River Valley and downstream areas. Therefore, for purposes of this PEIS, diversion of
these flows in the U.S. is considered to be a reduction in transboundary river flows.
11 Wet weather is defined as 72 hours following a rainfall event of 0.1 inches or greater. See (PG
Environmental, 2021g] for additional information.
12 Implementing thresholds that are based on instantaneous flow rates (rather than average daily flow rates)
would require real-time flow gauging.
13 These thresholds were determined based on a feasibility-level engineering analysis of environmental
benefits attained from continuing to operate at times of high flow. Actual operating procedures would be
subject to refinement during both design and process optimization once the system is operational and may
differ from the thresholds used in analyses supporting this PEIS.
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
• The potential benefits of placing the diversion structure downstream of Stewart's Drain (to
capture additional transboundary flows) and the trash boom(s) proposed in Project J.
• The susceptibility of the river basin upstream of Dairy Mart Road to significant erosion and
sedimentation during high-flow events.
• The potential for the diversion structure to affect the performance of existing flood
protection structures.
• The potential for the diversion structure to interfere with CBP operations.
• The potential impacts to nearby residential areas.
• The potential environmental impacts from construction and operation.
• The projected capital and O&M costs.
The size of the diversion structure would likely depend on the location in future conceptual designs.
For example, if necessary to prevent scouring around the diversion structure and ensure capture of
bifurcated flows, the diversion structure would potentially incorporate a broad shotcrete apron
that spans a substantial portion of the floodplain. This apron, if necessary, would cover an area of
up to approximately 8 acres, depending on factors including the width of the river channel at the
selected location. Diverted river flows would be conveyed to an intake channel that would be
designed to promote separation of trash and sediment from the APTP influent, then through a
combination of screw pumps and gravity pipelines to the APTP headworks.
Construction of the diversion system would require excavation, vegetation removal, grubbing, the
use of temporary staging areas and access roads, and temporary damming and flow diversion of the
river. The project would require connection to existing utilities, including electrical with backup
generators for the pumps and communications.
The infrastructure proposed for Project F would be expected to require regular and ongoing O&M
activities to ensure operational reliability and efficiency (e.g., rehabilitation and replacement of
pump equipment, regular cleaning, and sediment removal from the intake structure). Up to
approximately five additional staff members would be required to accommodate the anticipated
increase in O&M needs. Binational negotiations regarding O&M responsibilities and funding for
Project F are ongoing.
Figure 2-13 depicts the anticipated general locations of project elements and construction activities
for Project F.
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Final Programmatic EIS: USMCA Mitigation of
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Description of Alternatives Considered
2.5.2.3 Project G: New SABTP
Project G includes the construction of a new 5-MGD conventional activated sludge plant14 at the
existing SABTP site in Mexico for secondary treatment of untreated wastewater that is currently
discharged to the Pacific Ocean via SAB Creek. The primary purpose of Project G is to improve the
quality of wastewater discharged from SAB Creek and reduce the associated water quality impacts
along the Pacific Ocean coastline near the international border. The proposed plant would be
designed to produce a final effluent with BOD5 and TSS less than 30 mg/L (monthly average).
The proposed new and expanded facilities and processes for Project G are described below.
• Preliminary treatment. Preliminary treatment would consist of mechanically cleaned
coarse bar screens and vortex grit removal.
• Primary treatment. Primary treatment would consist of two rectangular primary settling
tanks designed to remove approximately 50 percent of the influent BOD5 loading and 30
percent of the influent TSS loading. Each primary tank would be approximately 20 feet
wide, 120 feet long, and 15 feet deep.
• Secondary treatment. The new plant would include a step-feed activated sludge process
consisting of two aeration tanks (reactors) and three rectangular secondary clarifiers. This
process is estimated to achieve TSS and BOD5 removals of 95 percent and would have the
flexibility to adapt to different operating conditions. The step-feed process can be operated
in three modes:
- Plug flow activated sludge. If all influent is directed to the front of the aeration tanks, the
process would operate in plug-flow activated sludge mode. This mode would provide
the greatest BODs removal efficiency if influent loadings are relatively consistent.
- Step-feed activated sludge. If influent is distributed along the length of the reactor, it
would operate in the step-feed mode. The main advantage of this mode is that it tends to
even out the oxygen demand along the length of the reactor, enabling more efficient
aeration.
- Contact stabilization activated sludge. If high flows occur, all influent flows can be
directed to the last of four quadrants in the reactor. This mode would prevent biomass
washout when influent flow rates are high.
• Disinfection and discharge. Following secondary treatment, effluent would be disinfected
(e.g., using ultraviolet light or chlorination) as the final step before discharge to the Pacific
Ocean via SAB Creek.
14 Following implementation of Projects A, B, and D, all influent sources of wastewater to the SABTP would be
eliminated other than approximately 2.2 MGD of wastewater from the Playas de Tijuana neighborhood, which
is currently collected at the Playas Pump Station before conveyance to the SABTP. A 5-MGD plant at the
SABTP site would provide more than sufficient capacity to accommodate population growth in this
neighborhood through 2050, when flows are projected to be 2.6 MGD (PG Environmental, 2021f).
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
• Solids processing. The new plant would also have onsite solids processing facilities,
starting with a gravity thickening process. The thickened sludge would be stored in onsite
sludge storage tanks before being pumped to belt filter presses in a dewatering building.
The dewatered solids would be loaded into trucks for offsite disposal using a solids
conveyor and loading bay.
• Other improvements. The project would require connections to utilities, including
electricity with backup power and communications to support the pumps and equipment
for the proposed treatment system. The existing lighting and fencing for security would be
expanded around the proposed system.
EPA and USIBWC estimate that the treatment process at the new SABTP would have removal
efficiencies of approximately 96 percent for BOD5, 68 percent for total nitrogen, 71.4 percent for
total phosphorus, 96 percent for TSS, and greater than 99 percent for fecal coliform (with
disinfection).
Site modifications to accommodate construction of the new plant would include draining the
existing lagoons and decommissioning the existing SABTP. Project G would also involve temporary
land disturbance, including excavation and use of temporary staging areas, dredge pads, and access
roads. Temporary pumping support and additional electrical supply would re-route wastewater
during construction activities.
The proposed plant would require similar O&M activities to the ones described for Project D,
including removal, processing, and disposal of sediment, sludge, and trash, as well as occasional
rehabilitation and replacement of the force main, pumps, and equipment at the plant It is unknown
how many staff the Mexican entities operating the new plant would need to accommodate the
anticipated increase in O&M needs. Under Treaty Minute No. 328, Mexico would be responsible for
the construction costs for a similar but larger project at the SABTP. See Section 2.8 (Funding
Sources and Binational Agreement) for more information about the project in Treaty Minute No.
328 that corresponds to Project G.
Figure 2-14 depicts the anticipated general locations of project elements and construction activities
for Project G.
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
Project G: New SABTP
17771 Preliminary and primary treatment
~ Secondary reactors
~ Secondary clarifiers and disinfection
~ Solids processing
SAN
DIEGO
Tijuana
River
Figure 2-14. Project G (New SABTP) - Conceptual Locations of Project Components
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
2.5.2.4 Project H: Tijuana WWTP Treated Effluent Reuse
Project H includes installation of conveyance pipelines to route between 10.3 and 16.2 MGD of
treated effluent from the Arturo Herrera and La Morita WWTPs (which currently discharge to the
Tijuana River) in Mexico to the Rodriguez Dam impoundment. The primary purpose of Project H is
to improve water quality in the Tijuana River Valley and Estuary by reducing the frequency of dry-
weather transboundary flows caused by river flow rates that exceed the PB-CILA diversion
capacity. Project H would effectively increase the available pumping and treatment capacity of the
existing system by reducing the amount of treated effluent in the Tijuana River, thus reducing
overall river flow volumes and enabling the downstream system to divert and treat a higher
proportion of the remaining flow.
Treated effluent would be conveyed either directly to the Rodriguez Dam impoundment or to a
location upstream of the impoundment To route treated effluent directly to the impoundment,
Project H would include the following (details would change if the effluent were instead to be
conveyed upstream of the impoundment):
• Installation of a new pipeline from the Arturo Herrera WWTP to the Rodriguez Dam
impoundment (approximately 5,900 feet of new force main) and a new 10.5-MGD pump
station.
• Either of the following approaches for treated effluent from the La Morita WWTP:
- Installation of an entirely new pipeline from the La Morita WWTP to the Rodriguez Dam
impoundment (approximately 16,500 feet of new force main) and a new 5.8-MGD pump
station.
- Installation of a new pipeline from the La Morita WWTP (approximately 1,500 feet of
new force main) to connect to an existing, unutilized 15,000-foot pipeline to the
Rodriguez Dam impoundment, and a new 5.8-MGD pump station.
Further studies are needed to better define the scope of Project H, and EPA and USIBWC are
engaged in binational discussions related to the specifics and limitations of this project There are
currently several unknowns about the scope, such as the conditions and need for structural analysis
of the Rodriguez Dam impoundment, infiltration rates upstream of the impoundment, and
opportunities for beneficial reuse of the effluent A BWIP-funded study is planned to address these
unknown factors. The optimum location of the discharge (i.e., directly into the impoundment or
somewhere upstream of it) would be analyzed in a subsequent tiered NEPA analysis.
Installation of new pipelines and construction of the new pump stations would involve temporary
land disturbance, including earth disturbance during trenching and construction activities. The
sediment removed during pipeline installation would be backfilled, requiring temporary erosion
control and staging areas around the active construction site. Most of the project construction area
would be accessed using existing roadways, but new temporary, minor access roads would likely be
required in some areas. Other improvements would include ancillary utilities such as electrical
connections to provide power to the pump stations, backup generators, as well as fencing and
lighting.
Project H is expected to require up to approximately two additional staff to support O&M of the
proposed pipelines and pump stations. However, since Project H would involve separating the
WWTP effluent from the Tijuana River, O&M requirements and pumping and treatment
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
requirements downstream would be reduced in the Tijuana River diversion system (i.e., PB-CILA,
PB1-A, PB1-B, and either the SABTP or the ITP). As established by Treaty Minute No. 328, the U.S.
and Mexico would split construction costs for this project Binational negotiations regarding O&M
responsibilities and funding for Project H are ongoing.
2.5.2.5 Project I: ITP Treated Effluent Reuse
The purpose of Project I is to convey treated effluent from the ITP to Mexico for potential beneficial
reuse.15 This project involves constructing a new pump station in the northwest corner of the ITP
parcel and a 42-inch diameter, 3,700-foot force main from the pump station to PB1-B in Mexico.
The pump station would be designed to pump no greater than an average daily flow rate of 40 MGD,
due to PBl-B's capacity limitations. Therefore, daily ITP effluent flow rates above 40 MGD would
continue to be discharged to the Pacific Ocean via the SBOO.
The Project I feasibility analysis was limited to conveying the ITP's effluent to PB1-B. For the ITP
effluent to be beneficially reused in Mexico, additional treatment and conveyance facilities may be
necessary, depending on how and where the water will be reused. Further research and
coordination are necessary to identify the specific beneficial reuse opportunities in Mexico that this
project would enable, and to define the infrastructure upgrades in Mexico that are necessary to
convey treated effluent to the appropriate destination. Examples of necessary upgrades in Mexico
could include cleaning and rehabilitating pipelines (e.g., the parallel conveyance pipelines that
currently convey flows from PB1-A and PB1-B to the SABTP and SAB Creek), rehabilitating the PB1-
B pump station, and constructing new pipelines.
The force main would be installed via open-cut trenching in the U.S. and micro-tunneling under the
U.S.-Mexico border. The force main would be fitted with intermediate pressure release valves to
prevent pipe collapse and to enable preventative maintenance.
Binational negotiations regarding O&M responsibilities and funding for Project I are ongoing.
Figure 2-15 depicts the anticipated general locations of project elements and construction activities
for Project I.
15 Conveying treated effluent to Mexico for reuse, rather than keeping the effluent in the U.S. for reuse, is in
accordance with the terms of Treaty Minute No. 283, which states that "both Governments reserve the right
to return for reuse in their respective territories part or all of the [ITP] effluent corresponding to each
country's sewage inflows."
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
Project I: UP Treated Effluent Reuse
[3 Construct new pump station
Install new treated effluent pipeline
Existing pipelines
1 Parallel conveyance (approximate)
SOUTH BAY
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Figure 2-15. Project I (UP Treated Effluent Reuse) - Conceptual Locations of Project Components
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
2.5.2.6 Project J: Trash Boom(s)
Project J includes the installation of one or more trash booms in the Tijuana River channel in the
U.S., similar to those currently installed in Smuggler's Gulch and Goat Canyon, to capture trash and
allow for its removal from the river. The purpose of the project is to reduce downstream trash-
related impacts in the Tijuana River Valley and Estuary, particularly due to wet-weather transport
of trash to downstream areas. The trash boom(s) would be installed in the river main channel
between the U.S.-Mexico border and Dairy Mart Road and would be designed to float on the surface
and capture floatable trash, such as plastics. Based on the performance of the boom in Goat Canyon,
a trash boom in the river would be expected to capture approximately 75 percent of trash loads in
transboundary river flows, with potentially higher capture efficiency if multiple booms are used in
series.
The trash boom(s) would be located within the area shown in Figure 2-16, between approximately
3,200 and 8,300 feet downstream of the U.S.-Mexico border. The trash booms would likely be
constructed downstream of the energy dissipation section of the channelized river (due to expected
greater effectiveness in slower-flowing waters) and upstream of the river diversion system
proposed in Project F (to reduce trash interference with the river intake). Depending on the
location, a trash boom would cross a span of between approximately 700 and 870 feet Potential
trash processing area(s), if necessary, would be located either in the narrow parcel south of the
south levee (and between the primary and secondary border fences) or in a narrow parcel outside
the floodplain along the south boundary of the USIBWC-owned sod farm. Access to the processing
area would be provided via existing access ramps and gates in the secondary border fence;
depending on the location of the trash boom, new access ramps and gates may need to be built
instead. Dump trucks would likely use existing paved and dirt roads to access the processing area
and haul away trash for disposal.
Construction activities would require limited vegetation removal, grubbing, and grading in the main
channel to promote contact between the trash boom and the river surface. Construction would also
require localized excavation to construct the concrete footings that secure the ends of the trash
boom.
Once the trash boom is constructed, it would require occasional maintenance to extract the
captured trash (using equipment such as a bulldozer or front-end loader). Trash would accumulate
upstream of the trash boom until conditions allow extraction to occur. The timing and frequency of
trash extraction would depend on factors including site conditions, current and forecasted flow
conditions, and equipment availability, but ideally extraction would take place shortly after wet-
weather events that result in substantial trash capture. Extracted trash would potentially require
temporary staging in a processing area until being loaded onto dump trucks and hauled to a local
solid waste disposal site. The timing and frequency of trash hauling would depend on factors
including availability of trucks and hauling crews, but ideally hauling would take place as soon as
possible after trash is extracted from the river.
Binational negotiations regarding O&M responsibilities and funding for Project J are ongoing. The
California State Water Quality Control Board voted on July 19, 2022 to approve $4 million in funds
for a trash boom pilot study, the results of which will help refine the scope, effectiveness estimates,
and understanding of the operational impacts of this project
Figure 2-16 depicts the anticipated general locations of project elements and construction activities
for Project J.
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Description of Alternatives Considered
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Project J: Trash Boom(s)
| | Area under consideration for trash boom(s)
Potential trash processing area(s)
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Tijuana
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TIJUANA
Figure 2-16. Project J (Trash Boom[s]) - Conceptual Locations of Project Components
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2.6 Identification of Preferred Alternative and Environmentally Preferable Alternative
EPA and USIBWC did not identify a preferred alternative in the Draft PEIS but have done so in this
Final PEIS after thorough review of all comments on the Draft PEIS and all applicable information.
The preferred alternative is Alternative 2 (Core and Supplemental Projects) because it would best
fulfill the purpose and need for action as it is the comprehensive solution. EPA and USIBWC
determined this after considering a variety of factors (e.g., economic, environmental, and technical).
The Supplemental Projects listed in Alternative 2 are necessary components to effectively address
public health concerns that stem from poor water quality and trash flows. Alternative 2 would be
the most effective alternative for addressing numerous water quality, trash, public health, climate
change, and environmental justice concerns and would further efforts to achieve water quality
standards in coastal waters and in the Tijuana River and Estuary. As described in Section 4.2
(Marine Waters), EPA and USIBWC estimate that full implementation of Alternative 2 would nearly
eliminate tourist (dry) season beach impacts in southern San Diego County resulting from exposure
to norovirus pathogens in untreated wastewater discharges.
When issuing the ROD, EPA and USIBWC will also identify the environmentally preferred alternative,
which may or may not be the same as the preferred alternative (40 CFR § 1505.2).
Within Alternative 2, Projects A (Expanded ITP) and B (Tijuana Canyon Flows to ITP) have multiple
proposed sub-options. EPA and USIBWC have determined that Project A, Option A3 (Expand to 60
MGD) and Project B, Option B1 (Trenching via Smuggler's Gulch and Monument Road) are the
preferred sub-options for Alternative 2. Project A, Option A3 is preferred because it would provide
capacity to accommodate flows from the International Collector and the canyons, as well as
capacity for current and projected wastewater flows through 2050. Project B, Option B1 is
preferred because it would be considerably less expensive than Option B2 (Trenchless Installation
via Smuggler's Gulch and Under Mesa) and has considerably more certainty in its engineering and
operational feasibility than Option B3 (Connect to Existing Canyon Collector System) since the ITP
condition assessment is not yet complete.
It is anticipated that the Proposed Action would be subject to review pursuant to the California
Environmental Quality Act (CEQA), which requires the identification of the environmentally superior
alternative. EPA and USIBWC would expect the environmentally preferred alternative to also be the
environmentally superior alternative.
2.7 Alternatives Eliminated from Evaluation in This PEIS
2.7.1 Projects and Sub-projects from EPA's Initial Set of 10 Projects
As discussed in Section 2.1 (Formulation of Alternatives), EPA began with an initial set of 10
projects—identified as Projects 1 through 10 in Section 2.1.1 (Identification of Projects to Undergo
Feasibility Analysis)—that were evaluated for technical, economic, and environmental feasibility.
EPA then defined a set of alternatives, each consisting of an assemblage of projects and their
individual components and sub-projects, and applied the Augmented Alternatives Analysis scoring
process to eliminate alternatives based on consideration of their scores, estimated costs and
benefits, and cost constraint assumptions (PG Environmental, 2 02 If).
As a result of this process, several individual projects or sub-projects from the initial set of 10
projects were not among the projects constituting the highest-scoring alternative, the
Comprehensive Infrastructure Solution (Alternative 1-2). See Section 2.1.3 (Alternatives Analysis),
the Water Infrastructure Alternatives Analysis report (PG Environmental, 2021f), and EPA's
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website16 for additional information. These projects and sub-projects were therefore eliminated
from detailed study in this PEIS and are not represented in any of the evaluated alternatives.
Additionally, based on further deliberation during the scoping phase of this PEIS, one sub-project in
the Comprehensive Infrastructure Solution (Project 4, sub-project 2) was eliminated from detailed
study in this PEIS. Each eliminated project and sub-project, and the reasons for elimination, are
briefly summarized below:
• Project 1 (New Tijuana River Diversion System in the U.S. and Treatment in the U.S.):
- Sub-project 1 (Tijuana River diversion system) and sub-project 3 (new APTP)—
specifically, the 100-MGD and 163-MGD capacity options—were determined to be
technically feasible but were eliminated from detailed study because of high expected
O&M costs and limited benefits over the 35-MGD and 60-MGD sized diversions and
treatment plants (PG Environmental, 2021a).
- Sub-project 2 (82-MG off-channel storage basin) was eliminated from detailed study
because EPA determined it to be technically feasible but not practical, and various
implementation and regulatory issues would delay, complicate, and potentially prevent
its implementation (PG Environmental, 2021a). Stakeholder opposition and comments
received during the public scoping period also contributed to the decision to eliminate
this sub-project from detailed study.
• Project 3 (Treat Wastewater from the International Collector at the ITP), sub-project 3
(replace International Collector with a new pipeline in the U.S.) was eliminated from
detailed study because CESPT is moving forward with a separate BWIP-funded effort to
install a new redundant International Collector pipeline in Mexico to reduce the risk of line
failures; see Section 2.9 (Related Projects). Rehabilitation of the existing International
Collector pipeline in Mexico is part of the Proposed Action under Project C (Tijuana Sewer
Repairs).
• Project 4 (Shift Wastewater Treatment of Canyon Flows to U.S. [via Expanded ITP or
SBWRP] to Reduce Flows to the SABTP), sub-project 2 (upgrading the canyon flow
diversion structures in Smuggler's Gulch and Goat Canyon) was eliminated from detailed
study because, based on further coordination with USIBWC and CBP, EPA determined that
the scope defined in the feasibility memorandum would result in operational impacts to the
diversion and treatment processes. Specifically, modifying the diversion structure to
prevent pooling of wastewater would reduce the settling of pollutants out of the pooled
wastewater and potentially result in damage to the piping and pumping system. EPA is
continuing to work with USIBWC and CBP to identify viable solutions, to be funded and
implemented through a separate effort, to reduce CBP safety risks in these areas.
• Project 5 (Enhance Mexico Wastewater Collection System to Reduce Flows into the Tijuana
River), sub-projects 2 through 6 involved extending wastewater collection facilities into
developed butunsewered areas; rehabilitating or replacing existing local pump stations;
rehabilitating or replacing the existing local sanitary sewer system; expanding the Tijuana
16 See https://www.epa.gov/sustainable-water-infrastructure/tijuana-river-watershed-technical-evaluation-
infrastructure.
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sanitary sewer system to account for future growth; and renovating and expanding
treatment capacity in Tijuana to treat the wastewater captured by the sanitary system to
accepted pollutant removal standards. These sub-projects were eliminated from detailed
study because, while they are technically feasible, implementation would collectively take
decades to implement and would likely cost several billion dollars. Therefore, extending,
rehabilitating, and upgrading the system is not feasible within the scope or current level of
funding provided by the USMCA, although these upgrades should occur as part of the long-
term infrastructure renewal plan for the City of Tijuana (PG Environmental, 2021j).
• Project 6 (Construct New Infrastructure to Address Trash and Sediment):
- Sub-project 1 (restoration of the Tijuana River main channel to its original 1977 design
configuration) was eliminated from detailed study because, while technically feasible to
construct, the sediment disposal requirements may adversely impact the sub-project's
overall feasibility. Specifically, annual cleaning of the channel would involve very high
annual O&M costs and 40-year life cycle costs. Removing sediment from the restored
channel would require a very high volume of truck traffic and thus present the logistical
challenge of identifying a partner that could truck such a large volume of material (PG
Environmental, 202Id).
- Sub-project 2 (U.S.-side sediment basin in Smuggler's Gulch immediately north of the
border) was eliminated from detailed study because the County of San Diego is moving
forward under a California Coastal Conservancy grant to fund design and construction
of this project, including a trash boom, on an accelerated schedule; see Section 2.9
(Related Projects).
- Sub-project 3 (Mexico-side, in-channel sediment basin in Smuggler's Gulch immediately
south of the border) was eliminated from detailed study because this project would be
redundant with a recently constructed basin in Mexico, located upstream of the
proposed location of this sub-project, that is likely to be effective at reducing sediment
loads in flows through the canyon (PG Environmental, 2021d).
- Sub-project 4 (U.S.-side pilot channel in Yogurt Canyon and north of Monument Road)
was eliminated from detailed study because EPA determined that the pilot channel
would be ineffective at preventing flooding along Monument Road and, based on
discussions with California State Parks, constructing the full pilot channel is unlikely to
receive regulatory approval (PG Environmental, 2021d).
- Sub-project 5 (U.S.-side sub-project to raise Monument Road downstream of Yogurt
Canyon) was eliminated from detailed study because EPA determined that California
State Parks is planning to implement a similar project under a separate effort (PG
Environmental, 202Id).
• Project 7 (Divert or Reuse Treated Wastewater from Existing Wastewater Treatment Plants
in Mexico to Reduce Flows into the Tijuana River), sub-project 2 (piping of La Morita and
Arturo Herrera WWTP treated effluent directly to the SBOO) was eliminated from detailed
study due to its higher capital cost, potential challenges with U.S.-side permitting
requirements, and uncertainty regarding treated effluent quality (PG Environmental,
2021k). Additionally, this sub-project would notprovide potential for reuse ofthe treated
effluent
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• Project 8 (Upgrade the SABTP to Reduce Untreated Wastewater to Coast) construction of a
new 10-MGD or 40-MGD plant at the existing SABTP site was eliminated from detailed
study because EPA determined that a 5-MGD conventional activated sludge plant would be
sufficient to provide the level of treatment needed to treat flows from coastal communities
in Mexico through the year 2050 (PG Environmental, 2021f). This assumes that wastewater
flows from the International Collector, Los Laureles Canyon, and Matadero Canyon would
be conveyed to the U.S. for treatment rather than to this new plant at the SABTP site.
• Project 9 (Treat Wastewater from the International Collector at the SBWRP) was eliminated
from detailed study because the City of San Diego determined it was not economically
feasible to sell the plant due to of the cost of modifying existing infrastructure to reroute the
city's wastewater to the Point Loma WWTP for treatment (PG Environmental, 202 If], An
existing "emergency connection" pipeline from the border area to the Point Loma WWTP
exists and was historically used for sending ITP treated effluent to the Point Loma outfall,
but this pipeline has not been in operation for many years and could require extensive
rehabilitation or reconstruction to reliably convey wastewater or treated effluent.
• Project 10 (Sediment and Trash Source Control) included source control best management
practices (BMPs) in Mexico—specifically, road paving; trash and tire collection, processing,
and disposal; public education, outreach, and participation programs; land stabilization;
and "green infrastructure" to reduce erosion and sedimentation. After further
consideration, this project was eliminated from detailed study because funding and
implementation of these types of source control practices may not be consistent with EPA's
authority to implement "high priority treatment works"17 pursuant to the USMCA
Implementation Act and "municipal drinking water and wastewater infrastructure
project[s]" under BWIP. These types of source control projects have been, and may continue
to be, funded under other EPA programs such as Border 2025.
2.7.2 Alternatives Other Than the Comprehensive Infrastructure Solution
As discussed in Section 2.1.3 (Alternatives Analysis) and the Water Infrastructure Alternatives
Analysis report (PG Environmental, 202 If), EPA defined an initial set of 39 alternatives, with each
alternative consisting of an assemblage of projects and their individual components and sub-
projects. EPA eliminated alternatives that scored poorly based on evaluation of four environmental
performance metrics (BODs load reduction to the Tijuana River, BOD5 load reduction to SAB Creek,
sediment load reduction in the Tijuana River, and reduction of days with transboundary flows in
the Tijuana River) and eliminated alternatives with redundant projects or incompatible elements
(e.g., exceedance of the SBOO discharge capacity). Finally, EPA applied the Augmented Alternatives
Analysis scoring process and eliminated alternatives based on consideration of their scores,
17 Section 821 of the USMCA Implementation Act gives authority and direction to the EPA Administrator to
"carry out the planning, design, construction, and operation and maintenance of high priority treatment
works in the covered area to treat wastewater (including stormwater), nonpoint sources of pollution, and
related matters resulting from international transboundary water flows originating in Mexico."
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estimated costs and benefits, and cost constraint assumptions, as documented in the Water
Infrastructure Alternatives Analysis report (PG Environmental, 2021f).18
As a result of this process, EPA identified a highest-scoring alternative—the Comprehensive
Infrastructure Solution (Alternative 1-2)—and used the individual projects and sub-projects
constituting the Comprehensive Infrastructure Solution to form the basis for the alternatives
evaluated in this PEIS. All other alternatives defined during this process (i.e., all other combinations
of individual projects and sub-projects) were therefore eliminated from detailed study in this PEIS,
even if they do not include any of the individual eliminated projects and sub-projects identified in
Section 2.7.1 (Projects and Sub-projects from EPA's Initial Set of 10 Projects). See the Water
Infrastructure Alternatives Analysis report (PG Environmental, 2021f) for documentation of the
alternatives development and scoring process.
2.7.3 Other Projects Identified Based on Public Scoping Comments
During the NEPA public scoping period for this PEIS, EPA and USIBWC received scoping comments
from public citizens, federal and tribal representatives, non-governmental organizations, and a
variety of other stakeholders. Some of these comments suggested projects to be considered as part
of the range of alternatives evaluated in the PEIS. As summarized below, EPA and USIBWC
considered all submitted projects but eliminated each from detailed study in the PEIS.
EPA and USIBWC determined that the following projects suggested by commenters during the PEIS
scoping period are reasonable but decided to eliminate them from further study for the reasons
stated below, in accordance with 40 CFR§ 1502.14(a):
• EPA and USIBWC considered incorporating projects that would implement the reuse of ITP-
and/or APTP-treated effluent in the U.S. (e.g., for aquifer replenishment or reintroduction
into the riparian environment), in addition to the two projects (Supplemental Projects H
and I) that would promote reuse of treated effluent in Mexico. EPA and USIBWC considered
this as a reasonable alternative within the context of binational negotiations. However,
reuse of ITP-treated effluent in the U.S. was eliminated from detailed study because, per
Treaty Minute No. 283, Mexico reserves the right to return for reuse part or all of treated
effluent from the ITP. Reuse of APTP-treated effluent in the U.S. was eliminated from
detailed study because, at this time, EPA and USIBWC are not aware of suitable reuse
opportunities for advanced primary treated effluent However, the Proposed Action would
not prevent the future implementation of water reuse projects for APTP-treated effluent,
should a suitable reuse opportunity be identified in the future.
• EPA and USIBWC considered 1) incorporating secondary treatment of diverted Tijuana
River water, in addition to advanced primary treatment that is part of the Proposed Action
under Projects D and E, and 2) incorporating tertiary treatment (with disinfection) of
wastewater from Mexico, in addition to secondary treatment that is part of the Proposed
Action under Project A. EPA and USIBWC eliminated both approaches from detailed study
18 For example: Alternative G was one of the initial set of 39 alternatives identified by EPA. This alternative
consisted of a 35-MGD APTP; expansion of the ITP to 60 MGD; and reuse of treated effluent from the Arturo
Herrera and La Morita WWTPs. This specific combination of projects and sub-projects was eliminated
following Round 1 of the Augmented Alternatives Analysis scoring process due to its relatively low score of
204 points as compared to 287 points for the highest-scoring alternative in Round 1 (Alternative I).
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for the following reasons—however, the Proposed Action would not prevent the eventual
expansion of the ITP to include tertiary treatment, should sufficient funding and suitable
reuse opportunities be identified in the future:
- Based on preliminary capital cost estimates, incorporation of secondary treatment for
diverted river water would cost an additional $375 million (35-MGD capacity) to $600
million (60-MGD capacity), and incorporation of tertiary treatment of wastewater
would cost an additional $800 million (50-MGD capacity). These prohibitive costs would
prevent USMCA and BWIP funds from being used for a larger range of reasonable
alternatives that successfully reduce contaminated transboundary flows and would
therefore hinder the ability to fully address the purpose and need for action.
- EPA and USIBWC estimate that water quality-based effluent limits for the anticipated
National Pollutant Discharge Elimination System (NPDES) permits for the APTP and the
expanded ITP could readily be met with primary and secondary treatment, respectively.
Investing in additional treatment for either plant would not further the purpose and
need for action (i.e., would not further reduce transboundary flows from Tijuana that
convey pollutants, sewage, and/or trash into the U.S.).
- The intermittent flow rate of wastewater and Tijuana River water, particularly during
low-flow periods in dry-weather conditions, presents technical challenges with
secondary treatment as biological processes used to separate and break down organic
matter, TSS, and other pollutants operate best under constant flow. During low-flow
conditions, the microorganisms breaking down effluent may not receive enough supply
to sustain their populations, thus increasing O&M costs (due to the need to replenish
microorganism populations) and lowering treatment efficiency.
• EPA and USIBWC considered whether maintenance and operation of the PB-CILA river
diversion could be shifted to the responsibility of the U.S. with the goal of improving
operational reliability during dry-weather conditions. This was eliminated from detailed
study because it would represent a significant shift in binational responsibilities under
Treaty Minute No. 283 to prevent transboundary flows. However, as part of binational
negotiations for the USMCA Mitigation of Contaminated Transboundary Flows Project, EPA
and USIBWC are exploring other options to increase U.S. financial support for O&M
activities in Mexico and thus improve the reliability of the river diversion system.
• EPA and USIBWC considered incorporating a project to install a trash boom in the Tijuana
River in Mexico (i.e., upstream of the border) to intercept trash in wet-weather flows before
it enters the U.S. This was eliminated from detailed study due to concerns about limited
effectiveness due to high flow rates in the concrete-lined channel, security of this
infrastructure (e.g., risk of vandalism or theft), and inability to identify an agency in Mexico
whose responsibilities would include O&M of a trash boom.
EPA and USIBWC determined that the following projects suggested by commenters are potentially
technically and/or economically feasible but do not meet the purpose and need for action, may not
be consistent with EPA's authority to implement "high priority treatment works" pursuant to the
USMCA Implementation Act and "municipal drinking water and wastewater infrastructure
project[s]" under BWIP, and/or involve broad, system-wide interventions that would take decades
to implement and thus would not provide a timely solution for addressing contaminated
transboundary flows. Therefore, these projects were not considered to be reasonable alternatives
per 40 CFR § 1508.1(z) (2022) and were eliminated from detailed study. However, this assessment
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is based on limited information about the suggested projects and did not involve a detailed
feasibility assessment
• Separation of the storm water and sewage systems in T ijuana.
• Utilization of a treatment plant in Mexico for reclamation and reuse of untreated
wastewater and/or treated effluent.
• Installation of micro-treatment systems in Tijuana.
• Promotion of home (domestic) water reuse in Tijuana.
• Establishment of a recycling program in Tijuana to prevent solvents, detergents, and
chemicals from entering the waste stream.
• Remediation and restoration of the Tijuana River Valley to its historical environmental
conditions.
• Extension of the SBOO to deeper offshore waters.
EPA and USIBWC determined that the following projects suggested by commenters are not
technically and/or economically feasible, do not meet the purpose and need for action, and may not
be consistent with EPA's authority to implement "high priority treatment works" under the USMCA
Implementation Act and "municipal drinking water and wastewater infrastructure project[s]"
under BWIP. Therefore, these projects were not considered to be reasonable alternatives per 40
CFR § 1508.1(z) (2022) and were eliminated from detailed study. However, this assessment is
based on very limited information about the suggested projects and did not involve a detailed
feasibility assessment:
• Introduction of a continuous flow of water into the upper Alamar River in Mexico to allow
stagnant pools of untreated wastewater to be conveyed downstream to the PB-CILA river
diversion.
• Installation of 1,000-foot-long rock jetties at the U.S.-Mexico border to redirect
contaminated longshore currents away from the U.S. shoreline.
2.7.4 Other Projects Identified Based on Public Comments on the Draft PEIS
During the NEPA public comment period for the Draft PEIS, EPA and USIBWC received comments
from community members, federal representatives, non-governmental organizations, and a variety
of other stakeholders. Some of these comments suggested adjustments to the projects described in
the Draft PEIS.
EPA determined that the following projects suggested by commenters during the Draft PEIS
comment period were not reasonable alternatives in accordance with 40 CFR§ 1508.1(z):
• EPA and USIBWC considered the possibility of discharging a portion of the secondary-
treated effluent from Project A (Expanded ITP) to the Tijuana River in the U.S. upstream of
Dairy Mart Road Bridge. This was eliminated from detailed study for the following reasons:
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- The discharge would likely be unable to meet the water quality-based effluent
limitations required for a NPDES permit—due, in part, to the lack of dilution in the river,
particularly during dry-weather days.
- This alternative would not meet the purpose and need for action because it would not
"reduce transboundary flows from Tijuana." Under current conditions, untreated
wastewater reaches the Tijuana River through transboundary river flows and
occasional flows through the canyons. Returning treated effluent to the river would
introduce, rather than eliminate, a source of pollutant loadings to the river, resulting in
a net increase in pollutant loadings to the Tijuana River on days when transboundary
river and canyon flows do not occur. This discharge would contribute to continued
water quality exceedances in the river, estuary, and nearshore coastal waters for
numerous pollutants including nutrients, indicator bacteria, and trace elements (e.g.,
selenium) and would be inconsistent with Treaty Minute No. 320 regarding binational
efforts to improve water quality in the Tijuana River Basin.
- Discharge of ITP treated effluent to the Tijuana River would potentially be inconsistent
with Treaty Minute No. 283, which states that Mexico reserves the right to return part
or all of the treated effluent from the ITP for reuse.
• EPA and USIBWC considered the possibility of discharging primary-treated effluent from
Projects D and E (APTP Phases 1 and 2) to the Tijuana River in the U.S. upstream of Dairy
Mart Road Bridge. Similar to the above, this was eliminated from detailed study because of
1) the inability to meet water quality-based effluent limitations required for a NPDES
permit and 2) inconsistency with the purpose and need for action because it would
introduce, rather than eliminate, a source of pollutant loadings to the river on days when
the APTP treats diverted river flows.
EPA and USIBWC considered extending the wastewater collection system around coastal areas in
Mexico, eliminating all discharges from the SABTP, temporarily treating flows at Punta Bandera,
and implementing safety improvements to the southern Hollister Street Bridge, which were
suggested by commenters. See Appendix A (Response to Comments on Draft Programmatic
Environmental Impact Statement) for reasonings as to why these projects were not included in this
Final PEIS.
2.8 Funding Sources and Binational Agreement
The U.S. and Mexico have recently negotiated two agreements: the first being a Statement of Intent
(SOI) signed between EPA and CONAGUA on July 1, 2022, and the second being a treaty minute
signed by two sections of the IBWC on July 19, 2022 and entered into force on August 18, 2022.
These agreements include a prioritized list of sanitation infrastructure projects in parallel with this
NEPA process. Both agreements outlined capital cost sharing, and the SOI identified a combination
of funding sources, including:
• USMCA Implementation Act appropriations ($300 million).
• BWIP funds from EPA and managed by NADBank, a binational financial institution that
assists with project development and oversight during project implementation, including
evaluating infrastructure investment needs, managing BWIP grant funds and requirements,
and monitoring construction management.
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• Cost share agreements with Mexico such as those defined under Treaty Minute No. 328.
• Additional not-yet-identified federal, state, and/or local appropriations authorized by the
respective authorities and laws of each country. Examples of other potential federal funding
sources that could be used to support the Proposed Action include Mexico's Planning
Mechanism (Mecanismo de Planeacion, or MECAPLAN) and the National Infrastructure
Fund. Additionally, the California legislature recently allocated $35 million for border water
quality improvement projects in the 2021 and 2022 Budget Acts.
IBWC Treaty Minute No. 328 "Sanitation Infrastructure Projects in San Diego, California — Tijuana,
Baja California for Immediate Implementation and for Future Development" designates projects for
immediate implementation (i.e., operational by 2027), projects for future consideration in
negotiations, and O&M responsibilities. Several of the projects specified in the treaty minute are the
same as, or similar to, those evaluated in this PEIS. Table 2-4 compares the projects in this
Proposed Action to the corresponding projects in Treaty Minute No. 328.
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Table 2-4. Comparison of Projects in the PEIS Proposed Action and Corresponding Projects in Treaty Minute No. 328
PEIS Proposed Action
Corresponding Projects in Treaty Minute No. 328
Project
Description
Category
Description
CategoryJ
A: Expanded ITP
Expand ITP to 40 MGD, 50 MGD, or 60 MGD
Core Project
Expand ITP to 50 MGD
Immediate
Further expansion of ITP
Future
B: Tijuana Canyon
Flows to ITP
Install pipelines to convey flows from Los Laureles
and Matadero Canyons by gravity to ITP (via one of
three options for pipeline route in U.S.)
Core Project
Convey flows from Los Laureles and Matadero
Canyons by gravity to ITP
Future
C: Tijuana Sewer
Repairs
Implement repairs for seven sewer
rehabilitation/replacement subprojects in Tijuana
Core Project
Implement repairs for the same seven
subprojects listed in PEIS
Immediate
D: APTP Phase 1
Construct 35-MGD APTP
Core Project
Construct APTP (capacity not specified)
adjacent to ITP to treat flows from the Tijuana
River
Future
E: APTP Phase 2
Expand APTP to up to 60 MGD
Supplemental
Project
F: U.S.-side River
Diversion to APTP
Divert Tijuana River to convey transboundary flows
to APTP for treatment
Supplemental
Project
Divert Tijuana River to convey transboundary
flows to APTP for treatment
Future
G: New SABTP
Construct 5-MGD SABTP with secondary treatment
(conventional activated sludge) and disinfection
Supplemental
Project
Construct 18-MGD SABTP with secondary
treatment (oxidation ditch process) and new
656-foot ocean outfallb
Immediate
H: Tijuana WWTP
Treated Effluent
Reuse
Install 5,900-foot pipeline from Arturo Herrera
WWTP to Rodriguez Dam impoundment and new
10.5-MGD pump station; convey effluent from La
Morita WWTP to Rodriguez Dam impoundment by
either installing a 16,500-foot pipeline and 5.8-MGD
pump station or installing 1,500-foot pipeline to
connect to existing 15,000-foot pipeline and a 5.8-
MGD pump station
Supplemental
Project
Phase 1: Install 23,400-foot pipeline and two
new pump stations to convey effluent from
Arturo Herrera and La Morita WWTPs to
Rodriguez Dam impoundment
Immediate
Phase II: Construct conveyance facilities and
associated infrastructure to permit use of
Arturo Herrera and La Morita WWTP treated
effluent in Valle de las Palmas b
Future
1: ITP Treated
Effluent Reuse
Construct new pump station at ITP and 3,700-foot
force main from pump station to PB1-B in Mexico
Supplemental
Project
Construct return line for treated flows from
ITP in U.S. to PB-1 in Mexico
Future
J: Trash Boom(s)
Install one or more trash booms in Tijuana River
channel in U.S. to capture trash
Supplemental
Project
Install trash boom in Tijuana River to capture
trash
Future
a - "Immediate" projects are to be constructed and in operation by 2027. "Future" projects are preliminary and subject to modification or deletion,
b -The scopes of these two Treaty Minute No. 328 projects (18-MGD SABTP and Phase II Arturo Herrera and La Morita WWTP treated effluent reuse) are
similar in type and purpose but different in size and complexity from the corresponding projects in the Proposed Action (Projects G and H). EPA and USIBWC
therefore identified these as "Related Projects" in Section 2.9 (Related Projects) and considered their potential impacts in Section 4.21.5 (Cumulative Effects).
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Treaty Minute No. 328 identifies four projects for immediate implementation that have
corresponding projects in this Proposed Action, and specifies cost sharing provisions for these four
projects as follows:
• Project A (Expanded ITP): The treaty minute identifies expansion to 50 MGD as a project
for immediate implementation. The U.S. would be responsible for all the capital costs of the
expanded ITP. O&M costs for the expanded ITP would be split between the U.S. and Mexico
and would shift over time. From 2023 to 2032, Mexico would pay a pre-determined and
gradually increasing monetary amount per cubic meter of wastewater treated at the ITP.
During this time period, the U.S. would then cover the remaining O&M costs (estimated to
be approximately 80 percent of the total). Responsibilities for O&M costs starting in 2033
would be defined in a future treaty minute. Mexico would continue to be responsible for
disposal of sludge from the expanded ITP in accordance with Treaty Minute No. 283.
• Project C (Tijuana Sewer Repairs): Construction costs for the seven sewer collector
repair projects would be either split evenly between the U.S. and Mexico (Projects 1 and 6)
or fully funded by Mexico (Projects 2, 3, 4, 5, and 7). Mexico would be responsible for
implementation of and costs for O&M.
• Project G (New SABTP): Mexico would be fully responsible for construction costs. Mexico
would be responsible for implementation of and costs for O&M. (See the discussion below
regarding the scope of this project.)
• Project H (Tijuana WWTP Treated Effluent Reuse): Construction costs would be split
evenly between the U.S. and Mexico. Mexico would be responsible for implementation of
and costs of O&M.
Treaty Minute No. 328 identifies other projects for future consideration that have corresponding
projects in this Proposed Action—specifically, Projects B (Tijuana Canyon Flows to ITP), D (APTP
Phase 1), E (APTP Phase 2), F (U.S.-side River Diversion to APTP), I (ITP Treated Effluent Reuse),
and J (Trash Boom[s]). Responsibilities for funding construction and O&M for these projects would
be determined in future agreements.
Project G (New SABTP) of the Proposed Action and its corresponding project in Treaty Minute No.
328 are similar in type and purpose but different in size and complexity. Specifically, Project G
includes construction of a 5-MGD plant at the SABTP site to provide secondary treatment via
conventional activated sludge, followed by disinfection. EPA and USIBWC estimate that this 5-MGD
plant would provide sufficient capacity to treat the only influent wastewater to the SABTP site that
would remain after implementing Projects A, B, and D (wastewater from the Playas de Tijuana
neighborhood). However, negotiations for Treaty Minute No. 328 resulted in the inclusion of a
larger, 18-MGD plant at the SABTP site to provide secondary treatment via an oxidation ditch
process, followed by discharge via a new 656-foot ocean outfall.19 Construction costs for this plant
and outfall would be fully covered by Mexico. While the specific basis for the 18-MGD capacity is not
currently well understood by EPA and USIBWC, it may reflect a desire to 1) provide temporary
capacity to treat flows that may eventually be redirected to the U.S. for treatment under Proposed
19 While the project description in Treaty Minute No. 328 does not specify disinfection prior to discharge, EPA
and USIBWC anticipate that disinfection will be necessary for the effluent to meet water quality standards.
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Action Projects A, B, and D, and 2) accommodate long-term population growth. These two projects
are therefore based on substantially different assumptions regarding which wastewater flows
would continue to require treatment in Mexico and eventual discharge via SAB Creek, rather than
being conveyed to the U.S. for treatment and eventual discharge via the SBOO.
For this Final PEIS, EPA and USIBWC have elected to retain the Project G scope in this analysis as
described in the Draft PEIS (a 5-MGD plantwith no new ocean outfall). While Treaty Minute No. 328
defines priorities and identifies responsibilities for funding, project implementation, and O&M, it
also acknowledges that projects are contingent upon successful completion of the appropriate
environmental regulations for both countries (e.g., the decision-making process required by NEPA
for projects with a federal nexus). In other words, Treaty Minute No. 328 does not commit EPA and
USIBWC to funding or implementing the 18-MGD version of the SABTP plant described in the treaty
minute. Rather, the 18-MGD SABTP is to be funded and implemented entirely by Mexico. If
subsequent binational discussions were to contemplate funding from EPA, then there would be a
federal nexus and EPA would conduct an appropriate NEPA review in the form of a tiered NEPA
analysis, which would address any deviations from the scope presented in Project G of this PEIS.
2.9 Related Projects
The issues surrounding transboundary flows in the San Diego-Tijuana region, especially those
related to untreated wastewater, trash, and sediment in the Tijuana River Valley, have the attention
of various agencies and stakeholders in addition to EPA. Other international, federal, state, and local
entities have proposed or recently implemented projects to improve the management of
transboundary flows.
In 2009, various Tijuana River Valley agencies and interested parties convened to form the Tijuana
River Valley Recovery Team. The team developed the Tijuana River Valley Recovery Team Recovery
Strategy: Living with the Water, which identified 27 actions to clean up and restore the valley
(Tijuana River Valley Recovery Team, 2012). Following the recovery strategy, the team developed a
five-year action plan in 2015 containing 10 projects to move forward into implementation (Tijuana
River Valley Recovery Team, 2015). Some of the projects in the five-year action plan have been
implemented or are currently in progress and are considered here or in Section 4.21.5 (Cumulative
Effects) as appropriate (i.e., reclamation of the Nelson Sloan Quarry, targeted sediment and trash
removal projects, source reduction of sediment and trash).
Table 2-5 summarizes the projects in the area that are related to the Proposed Action in either
purpose or need and provides information on their current implementation status. These projects
and others are also discussed in Section 4.21.5 (Cumulative Effects).
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Table 2-5. Related Projects to Mitigate Contaminated Transboundary Flows in the Tijuana Area
Project
Proponent
Description
Status
Related Projects Included in Treaty Minute No. 328
1. Tijuana River
CONAGUA,
Immediate Project Bl: Rehabilitated pump station PB-CILA
Ongoing
diversion
CESPT, CILA,
and constructed a new Tijuana River intake (already
rehabilitation
EPA
completed as part of cost-sharing agreement with Mexico);
rehabilitate PBl-Aand PB1-B.
2. Rehabilitation of
CONAGUA,
Immediate Project B2: Rehabilitate the Buena Vista section of
Ongoing
the Collector Oriente
CESPT, EPA
the Collector Oriente sewer main and install 4,416 feet of
pipelines in Tijuana to reduce the risk of line failures and
untreated wastewater discharges that could affect the
Tijuana River.
3. Rehabilitation of
CONAGUA,
Immediate Project B3: Install a redundant line in Mexico to
Planned
the International
CESPT, EPA
reduce the risk of line failures and untreated wastewater
Collector (Phase 1)
discharges that could affect the Tijuana River.
4. Rehabilitation of
CESPT
Immediate Project B4: Rehabilitate a portion of the pipeline
Planned
line from PBl-Ato
in the segment that conveys flows by gravity from PB1-A to
SABTP.
SABTP by replacing 13,225 feet of pipeline.
5. Closing of the open
CESPT
Immediate Project B6: Encase approximately 19,685 feet of
Planned
gravity channel from
the open gravity channel from PB1-A to the SABTP with a
PB1-A to SABTP
pipeline to close that section of the channel.
6. Conveyance of
CESPT
Immediate Project B12: Lift station and force main to convey
Planned
wastewater from
wastewater from Sainz Canyon to the Arturo Herrera WWTP
Sainz Canyon to
by constructing a pump station and 5,577 feet of pipe with a
Arturo Herrera
capacity of 3.4 MGD.
WWTP
7. Rehabilitation of
CESPT
Immediate Project B13: Rehabilitate Matadero and Laureles 1
Planned
Matadero and
and 2 pump stations by replacing pumps, installing a new
Laureles 1 and 2
Motor Control Center at each station, and installing a new
pump stations
preliminary treatment system in each station's lift station.
8. Construction of 18-
CESPT
Immediate Project B14: Construct a new 18-MGD capacity
Planned
MGD SABTP
WWTP at SAB using an oxidation ditch process and
constructing a 656-foot ocean outfall.
9. Construction of
CONAGUA,
Immediate Project B16: Construct a backup power supply
Planned
PB-1 backup power
CESPT, EPA
system for the PB-1 electrical substation.
supply system
10. Reuse of effluent
CESPT
Future Project Bl: Construct new conveyance facilities and
Planned
from La Morita and
associated infrastructure to permit use of Arturo Herrera and
Arturo Herrera
La Morita WWTP treated effluent in Valle de las Palmas.
WWTPs (Phase II)
Other Related Projects
11. Smuggler's Gulch
County of San
Installed trash booms across the drainage swale in
Completed
trash booms
Diego
Smuggler's Gulch, downstream of the existing collector
structure.
12. Trash fence in
CESPT
Installed a trash wall/fence in Matadero Canyon roughly
Completed
Matadero Canyon
2,000 feet south of the border to screen trash before it
crosses the border into the U.S.
13. Rehabilitation of
CESPT
Installed approximately 1.2 miles of pipelines and
Completed
Collector Poniente
rehabilitated the Canon del Sainz-Los Reyes connection in
Segment 1A
Tijuana to reduce the risk of line failures and untreated
wastewater discharges to the Tijuana River.
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Table 2-5. Related Projects to Mitigate Contaminated Transboundary Flows in the Tijuana Area
Project
Proponent
Description
Status
14. Sediment
City of San
Dredging and excavation of sediment from the Smuggler's
Ongoing
excavation in
Diego
Gulch channel, downstream from Smuggler's Gulch to the
Smuggler's Gulch and
pilot channel, and in portions of the Tijuana River.
the Tijuana River
15. Trash boom in
Wildcoast
Installed a trash boom in Los Laureles Canyon approximately
Completed
Los Laureles Canyon
and City of
Tijuana
1.2 miles south of the border.
16. Repair ITP
USIBWC
Repair JB-1 to restore gates and flow control for influent
Planned
junction box 1 (JB-1)
from the International Collector to the ITP.
17. Smuggler's Gulch
County of San
Install a sediment capture basin and trash boom in
Planned
sediment and trash
Diego
Smuggler's Gulch to trap large trash/sediment flows and
capture facility
reduce downstream impacts. Widen existing culvert under
Monument Road to reduce flooding.
18. Monument Road
CA State
Improve Monument Road downstream of Yogurt Canyon to
Planned
Improvements at
Parks
ameliorate flooding.
Yogurt Canyon
19. Continued
USIBWC and
Continued wastewater treatment operations at the ITP and
Ongoing
operation of ITP and
City of San
SBWRP and discharge to the Pacific Ocean via the SBOO, in
SBWRP
Diego
addition to any added capacity under the USMCA project.
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3. AFFECTED ENVIRONMENT
3.1 Freshwater and Estuarine Resources
3.1.1 Hydrology
3.1.1.1 Tijuana River in Mexico (Upstream of U.S.-Mexico Border)
The Tijuana River originates in Mexico, formed by its major tributaries the Rio de las Palmas and
the Cottonwood-Alamar system before crossing into the U.S. The watershed, shown in Figure 3-1, is
bounded by the Laguna Mountains in the northeast, the Sierra Juarez Mountains in the south, and
the Pacific Ocean to the west and covers approximately 1,750 square miles, approximately three-
quarters of which are in Mexico. Nearly the entire length of the river in Tijuana is channelized in
concrete downstream of the Rodriguez Dam.
Five dams regulate flow in the Tijuana River tributaries, including Barrett Dam and Morena Dam on
Cottonwood Creek in the U.S. and Rodriguez Dam, Las Auras Dam, and El Carrizo Dam in Mexico.
The Rodriguez Dam has the most significant influence on the volume in the Tijuana River, as it
controls flows from approximately 56 percent of the watershed. There is no clear information on
the frequency with which upstream dams reach capacity (USACE, 2018, 2020],
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3.1.1.2 Tijuana River in U.S. (Downstream of U.S.-Mexico Border)
Downstream of the border, the Tijuana River flows through a concrete-lined trapezoidal channel
and levee system followed by an earthen-bottom channel with buried grouted riprap side slopes
(PG Environmental, 2022). This energy dissipation structure was constructed in the late 1970s to
reduce flow velocity, limit flooding, and promote sedimentation upstream of Dairy Mart Road. The
river, along with any inflows from Stewart's Drain, then flows into a natural earthen-bottom
braided alluvial channel system within a wide floodplain upstream of Dairy Mart Road and north of
the ITP. Since the energy dissipator was constructed, deep sediment deposits—up to 6 to 8 feet
deep in the main river channel—have accumulated in this section of the river and continue to
accumulate (Stantec, 2020a). See Section 3.1.1.5 (Wetlands and Delineated Aquatic Resources) for
more details on this section of the river. Downstream of Dairy Mart Road, the river flows generally
northwest through dense riparian habitat in the Tijuana River Valley Regional Park and eventually
to tidally influenced areas in the Tijuana Slough National Wildlife Refuge (NWR) and the Tijuana
River National Estuarine Research Reserve (TRNERR).
Over the past 150 years, the river channel has experienced numerous, and occasionally dramatic,
avulsions (i.e., changes in course) in response to high-flow events. As recently as 1993, a flooding
event resulted in the river establishing a new northern course downstream of Hollister Street (SFEI,
2017). The new river course exposes residents in the northern part of the Tijuana River Valley to
heightened flooding risk and the contaminants in the Tijuana River. The 1993 flood event
significantly damaged and destroyed bridges, roads, homes, and farms (Schoenherr, 2015). In the
early 1990s, a pilot channel stretching west from where the Tijuana River crosses under Hollister
Street was created to help direct storm flows away from northern areas of the valley (see Figure
1-1).
The U.S. portion of the Tijuana River was historically intermittent, but transboundary flows have
included more non-stormwater sources as the City of Tijuana has grown (City of Imperial Beach et
al., 2016). In 1979, the river became perennial due to urban runoff and untreated wastewater
releases occurring after the completion of the Tijuana River Flood Control Project, which
channelized flows through Mexico (SFEI, 2017). The river became intermittent again in the early
1990s with the implementation of wastewater treatment and management (SFEI, 2017).
Specifically, the PB-CILA diversion system located immediately upstream of the U.S.-Mexico border
conveys all dry-weather river flows to PB1-A or to the International Collector, so transboundary
river flows occur only during wet weather and during dry-weather shutdowns or malfunctions of
the PB-CILA diversion system (see Figure 1-6 regarding the frequency of these dry-weather
transboundary flows).
In the U.S., flows in the Tijuana River mainly occur during the rainy season, which begins as early as
October and ends as late as April. During this period, intermittent but very large flows occur
following storm events that typically result in a surge of peak flow that flushes through the estuary
and out to the ocean, followed by days with sustained and subsiding flow. Based on USIBWC flow
gage data collected just downstream of the U.S.-Mexico border since 2000, an average wet season
has featured approximately 96 days with river flows (i.e., approximately 53 percent of wet-season
days have flows) and approximately 9,000 million gallons (MG) of total flow over the course of the
season. However, flows fluctuate greatly from season to season, with wet-season flows since 2000
ranging from less than 1,000 MG to greater than 25,000 MG. The two-, five-, and 10-year flood
events are estimated to have peak flows of approximately 1,300; 5,400; and 11,000 cubic feet per
second (cfs), respectively (PG Environmental, 2022).
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However, for most of the year, conditions in the Tijuana River in the U.S. are characterized by
prolonged dry periods of very low to zero surface water flows—particularly during the dry season
commonly defined as spanning from Memorial Day to Labor Day. A typical dry season features
fewer than 10 days with river flows (i.e., less than 10 percent of dry-season days have flows) and
less than 100 MG of total flow over the course of the season. However, failures of the river diversion
system in Tijuana can result in extended periods of flow, such as in 2020 when transboundary river
flows occurred on nearly every day of the dry season.
Figure 3-2 depicts annual precipitation and the number of transboundary river flow days per year,
with the flow days further categorized based on the flow rate per day (i.e., number of days with
small flows versus large storm-driven flows). Table 3-1 shows the distribution of average days per
year with transboundary flows of varying flow rates. This table shows that most cumulative river
flows over a typical year occur during the small number of days with very high flow rates (i.e., while
only 13 percent of flow days have flows exceeding 165 MGD, flows on these days these contribute
75 percentofthe total annual flowvolume). Table 3-2 shows rainfall measurements from Brown
Field Municipal Airport with flow in the Tijuana River main channel. These exhibits are based on
flow data from the US1BWC Tijuana River flow gage covering the four-year period from January 1,
2016, to December 31, 2019.
a - Precipitation measurements collected at San Diego International Airport.
Figure 3-2. Annual Precipitation and Transboundary River Flow Days (by Daily Flow Rate), 2000-2020
Rainfall Years
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Table 3-1. Average Annual Distribution of Transboundary Flows in the Tijuana
River
Transboundary Flow Rate
(Average Daily, MGD)
Average Number of Days
Per Year
% of Total Annual Flow
0
212
0%
0.1-15.0
57
0.9%
15.1-30.0
19
2.5%
30.1-45.0
15
3.2%
45.1-60.0
16
4.9%
60.1-75.0
10
3.8%
75.1-90.0
5
2.4%
90.1-105.0
4
2.5%
105.1-120.0
1
0.6%
120.1-135.0
3
1.8%
135.1-150.0
2
0.6%
150.1-165.0
1
0.7%
>165.0
20
75%
Source: (PG Environmental, 2021g).
Table 3-2. Precipitation and Flow Correlation for the Tijuana River
Precipitation
(Inches)
Days of Flow
Total Flow (Million
Gallons)
Peak Instantaneous
Flow (cfs)
0.1
1.5
33
296
0.25
2.7
107
747
0.33
3.3
159
993
0.5
4.7
298
1,526
0.66
6.0
465
2,041
0.75
6.7
574
2,336
1
8.7
933
3,176
1.25
10.7
1,376
4,048
1.33
11.3
1,535
4,332
1.5
12.7
1,902
4,950
1.75
14.6
2,513
5,883
2
16.6
3,208
6,848
2.25
18.6
3,986
7,843
2.5
20.6
4,849
8,869
2.75
22.6
5,795
9,926
3
24.6
6,826
11,013
3.25
26.6
7,940
12,132
3.5
28.6
9,138
13,283
3.75
30.5
10,420
14,464
4
32.5
11,786
15,675
Source: (PG Environmental, 2021g).
Semi-arid riverine environments such as the Tijuana River Valley can be defined by high variability
in flow characteristics that may be influenced yearly seasonally or even daily. The Tijuana River
experiences extreme annual variability that is driven in part by climate cycles such as the El Nino-
Southern Oscillation and the Pacific Decadal Oscillation (SFEI, 2017). For example, gage data
collected between 1937 and 2010 show that peak annual discharge has ranged from 0 to 30,088 cfs
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and that the river contains 630 times more water during wet years than dry years (SFEI, 2017).
Mean peak annual discharge during thattime was 2,407 cfs (SFEI, 2017). The largest flood on
record occurred in January 1916 and had an estimated peak flow rate of 75,000 cfs, twice the flow
rate of any flood since (SFEI, 2017). Seasonal variability in river flows is also significant The river
can experience very high flows during the wet season, and periods with low to no flows during the
summer. Storm events in the watershed typically result in a surge of peak flow followed by days
with sustained and subsiding flow. The flood control structures upstream of Dairy Mart Road,
which are managed by USIBWC, can contain a 500-year flood event of up to 135,000 cfs (HDR,
2020a, 2020d). See Section 3.3 (Floodplains) for more information on flood control.
The United States Army Corps of Engineers (USACE) recently completed a hydrologic and hydraulic
study of the Tijuana River watershed using sources including data from four stream gages, physical
and operational data for four dams, and precipitation data, and calibrated the models to five storm
events. The resulting hydrographs are expected to be more accurate than other recent studies of
the watershed, although some uncertainty remains regarding the influence of the reservoirs during
significant storm events (USACE, 2020).
The volume and downstream extent of flows within the Tijuana River Valley are driven by complex
interactions with underlying geology, groundwater, vegetation, and climate. In general, surface
flows can percolate into the ground quickly in sandy substrates (SFEI, 2017). Under certain lower
flow conditions, the entire river flow infiltrates the ground before reaching the estuary.
Additionally, there is an unconfined aquifer in the alluvial fill below the river valley, which is
primarily refilled by direct rainfall, surface inflow, and intermittent flood events (CDPR, 2008).
When the aquifer is full or overflowing, groundwater seeps into the Tijuana River and sustains flow,
even during periods of low rain (USIBWC, 2008). Evapotranspiration, which is influenced by
climate (e.g., humidity, solar radiation, temperature fluctuations), can influence the horizontal
extent of stream flows in intermittent alluvial systems on a daily basis. This small-scale variability is
likely tied to short-term fluctuations in groundwater that are influenced by evapotranspiration
rates of groundwater-dependent vegetation (SFEI, 2017).
There are still several data gaps regarding the flow of the Tijuana River and the frequency with
which the river discharges through the estuary to the Pacific Ocean. The range of flow rates that
result in the Tijuana River passing through the estuary to the Pacific Ocean, the relative
contributions of water from the river and the canyons to these instances, and the frequency with
which this occurs are not well understood. Efforts to understand flow dynamics in the river are
complicated by the annual and seasonal variability and the introduction of treated and untreated
wastewater contributions as described earlier in this section. Furthermore, the river is diverted
upstream of the U.S.-Mexico border for treatment, and there is a lack of in situ data on the U.S. side
where there is currently only one stream flow gage, which has data from as early as 1962 (USACE,
2018). Some research suggests that precipitation and runoff are not well correlated in the river
(Tijuana River Recovery Project, 2010), which also makes itmore difficultto model expected flows.
3.1.1.3 Tijuana River Estuary
The Tijuana River Estuary is influenced by streamflow, tidal flux, wave action, and sediment flux.
The Tijuana River main channel enters the estuarine environment in the northern portion of the
valley along what is called the Tijuana River Slough. Various other "sloughs" are present in the
estuary that were formed from abandoned river channels or from tidal channels. Sediment
transport into and out of the estuary occurs near the ocean in the flood tidal deltas and from
upstream river flows, especially as a result of flood events. Tidal influence historically extended
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inland as far as 1.5 miles. However, the tidal prism volume (volumetric difference between the
mean high tide and the mean low tide) and the area of tidal influence has decreased in the late 20th
century due to a number of factors, including sediment deposition from the Tijuana River and
tributaries. The estuary transitions to upland and riparian habitat along ecological transition zones,
which predominantly consist of Alkali Meadow Complex/High Marsh vegetation zones. These
transition zones generally occur in areas to the south of the Naval Outlying Landing Field Imperial
Beach and not any farther east (SFEI, 2017). See Section 3.1.1.5 (Wetlands and Delineated Aquatic
Resources) for more background regarding the estuary.
3.1.1.4 Tributary Flows in the Tijuana River Valley
Smuggler's Gulch is west of the ITP and is referred to as Matadero Canyon south of the U.S.-Mexico
border. It has a subwatershed area of 3,762 acres, including the portions in Mexico (HDR, 2020a).
The ephemeral wash system that flows through Smuggler's Gulch collects stormwater and
wastewater flows from parts of the City of Tijuana and receives drainage from the surrounding
mesas. The canyon flow diversion structure (see Section 1.2 [Existing Diversion and Treatment
Infrastructure]) intercepts dry-weather transboundary flows and conveys them to the ITP. During
wet-weather flow conditions, the pump diversion is turned off and transboundary flows instead
continue north through a natural channel and a culvert under Monument Road, ultimately
discharging into the Tijuana River pilot channel.
Goat Canyon is located to the west of Smuggler's Gulch and is referred to as Los Laureles Canyon
south of the U.S.-Mexico border. It has a subwatershed area of 2,941 acres, including the portions in
Mexico, and is formed from Goat Canyon Creek, which is fed predominantly by runoff and other
water sources in Mexico. The canyon flow diversion structure intercepts dry-weather
transboundary flows and conveys them to the ITP. Wet-weather flows bypass the diversion
structure and continue northwest into two sediment basins, which capture sediment and trash and
are also intended to reduce flooding in downstream areas, including Monument Road (HDR,
2020d). Outflow from the sediment basins enters the Tijuana River Estuary.
Transboundary flows also occur at Canon del Sol, Silva Drain, and Stewart's Drain, located along the
border immediately south of the SBWRP and ITP (see Figure 1-2). Dry-weather flows at these
locations are intercepted by the canyon flow diversion structures. Wet-weather flows from Canon
del Sol are conveyed to the Tijuana River via underground piping with an outfall located
immediately northwest of the ITP. Wet-weather flows from Silva Drain flow overland into Stewart's
Drain, which discharges to the Tijuana River immediately east of the ITP.
3.1.1.5 Wetlands and Delineated Aquatic Resources
The Tijuana River Valley contains numerous freshwater and estuarine wetlands—most notably the
extensive, tidally flushed coastal salt marsh and saltpan habitat in the Tijuana River Estuary. In
1973, the Secretary of the Interior designated the Tijuana River Estuary as a National Natural
Landmark (NNL) to highlight the site's importance as an endangered species habitat and as one of
the finest saltwater marshes on the California coastline (National Park Service, 2020). In 2005, the
TRNERR was further designated a Ramsar "Wetland of International Importance" for several
criteria, including its value to supporting vulnerable and endangered species and critical habitats
(Ramsar Sites Information Service, 2022). Over recent decades, increased sediment deposition and
freshwater influence from the Tijuana River have affected wetlands in the estuary by decreasing
salinity, burying tidal channels, and causing the salt marsh to transition to upland habitat (Nordby,
2018). However, the California Department of Parks and Recreation (CDPR) and United States Fish
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and Wildlife Service (USFWS) are currently implementing a multi-phased program to restore tidal
exchange and wetland habitats in the estuary (TRNERR, 2022).
Other wetlands in the Tijuana River Valley include vernal pools, which form in topographic
depressions above poorly draining soils and are seasonally inundated for a few weeks to several
months by precipitation and/or overland flow. Vernal pools can provide habitat for a variety of
endemic species, including protected specialist species such as the federally listed San Diego fairy
shrimp (Branchinecta sandiegonesis), which is found in vernal pools in the TRNERR (CDPR, USFWS,
& NOAA, 2010). Additionally, historical sand and gravel extraction from the river valley—
particularly near Dairy Mart Road—impacted streamflow, sediment transport, and habitat mosaics,
creating residual burrow pits that now support perennial ponds (SFEI, 2017). Freshwater ponds,
wetlands, and riparian habitats in the Tijuana River Valley provide habitat for special-status20
wildlife species, including the least Bell's vireo (Vireo bellii pusillus) and light-footed Ridgway's rail
[Rallus longirostris levipes) (USIBWC, 2008).
PG Environmental performed a field delineation of wetlands and non-wetland waters within the
project area on November 3 and 4, 2021, following the guidelines in the 1987 U.S. Army Corps of
Engineers Wetland Delineation Manual (Environmental Laboratory, 1987), the Arid West Regional
Supplement (USACE, 2008), and the U.S. Army Corps of Engineers Field Guide to the Identification of
the Ordinary High Water Mark in the Arid West Region of the Western United States ("OHWM Field
Guide") (Lichvar & McColley, 2008). Wetlands and non-wetland waters were further classified by
hydrogeomorphic class (Brinson, 1993) and Cowardin classification (Cowardin etal., 1979). The
results of the field delineation are provided in Appendix B (Aquatic Resources Delineation Report),
shown in Figure 3-3 through Figure 3-9, and summarized in Table 3-3. Based on the field
investigations and supporting desktop analyses, PG Environmental ecologists identified 11 non-
wetland waters (covering 122.09 acres and 12,431 linear feet), seven wetland features (8.56 acres),
and 0.05 acres of other features in the surveyed area. These features may be subject to several
jurisdictions (and their authorities) including: USACE (CWA Section 404); Regional Water Quality
Control Board (RWQCB) (CWA Section 401 and the Porter-Cologne Water Quality Control Act);
California Department of Fish and Wildlife (CDFW) (California Fish and Game Code Section 1600);
and/or California Coastal Commission (CCC) (California Coastal Act [CCA]). Of the wetlands, all are
potentially jurisdictional wetland waters per CCC jurisdiction but only a portion meet the USACE
and state definitions as Waters of the United States (WOTUS) and Waters of the State (WOS),
respectively. Non-wetland waters within the project area generally include intermittent and
ephemeral streams and minor drainages, including the Tijuana River, Smuggler's Gulch, Goat
Canyon Creek, and multiple unnamed tributary channels. Further, potentially jurisdictional non-
wetland WOTUS and WOS are those that meet USACE definitions; all waters and other isolated
waters may also fall under CCC and state jurisdictions.
Within the project area, the variable hydrologic regime of the Tijuana River (characterized by
periods of no flow, minor baseflows, and larger flashy flows) influences the channel morphology
within the Tijuana River floodplain. Baseflows are primarily contained within a main low-flow
channel, while larger magnitude discharges frequently inundate most of the surrounding
20 Special-status wildlife species are defined as those species listed, proposed, or under review as endangered
or threatened under the federal Endangered Species Act (ESA) or the California Endangered Species Act
(CESA); designated by the CDFW as a Species of Special Concern or Fully Protected; or protected under the
federal Bald and Golden Eagle Protection Act (BGEPA).
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Final Programmatic EIS: USMCA Mitigation of
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floodplain, resulting in highly unstable channels that migrate within the boundaries of the active
floodplain. The limits of the active floodplain, as defined by field indicators and hydrologic
modeling, are potentially subject to jurisdiction under several federal and state agencies.
Freshwater emergent wetlands within the Tijuana River floodplain are highly temporal and
typically limited to low terraces within the main low-flow channel, which are subject to frequent
sedimentation and erosion. Mature riparian forest and scrub-shrub communities near Dairy Mart
Road Bridge are potentially subject to state jurisdictions as wetlands.
At the time of PG Environmental's site evaluation, wetland vegetation was present on alluvial
deposits in Smuggler's Gulch at varying cover densities throughout the channel bed and was
classified as a scrub-shrub wetland. In Goat Canyon, a short segment of incised channel on the
downstream end of the debris flow area was mapped as USACE WOTUS and non-wetland WOS
based on presence of a bed and bank.
Other aquatic features in the project area include several small ephemeral drainages that cross
under Dairy Mart Road and Monument Road and convey overland flows toward the Tijuana River
Valley, erosional features/swales near the Tijuana River border, and V-shaped concrete ditches that
convey roadside or surface runoff to stormwater capture systems.
See Section 6.1.2 (Freshwater and Estuarine Resources) for additional information on water
resources permits and regulations.
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Final Programmatic EIS: USMCA Mitigation of
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w
I.J I • .
Kv!waw2wwII
'i'i'i'1'i'1'1'i'1'i'i i i'1'i i i
M»-|IT %
Vi^lr<^lrVV^»V¥W<*WAV*V4*VW"*P*V* a '• » 4 4w4V4V<
*?*5iA3uSiiX*X&iXiXiSi3i3tiEiXaXiXiXiSi^m^^a^^tM
Tijuana River Floodplain
Aquatic Resources
Legend
Delineation Area
Jurisdiction
Waters WOTUS WOS CCC
Wetland WOTUS WOS CCC
500
1,000
I Feet
150
1 inch = 417 feet
300
HI Meters
'%.;?<¦
1 .": »-J JB«K &*?£
' m' rJWli' .^BBOfei J.*"'
rasa * K
I 9nH
Spatial Reference
PCS: NAD 1983 2011 StatePlane California VI FIPS 0406
GCS: GCS NAD 1983 2011
Datum: NAD 1983 2011
Imagery source: Digital Globe G-EGD
Imagery date: 11/05/2021
Data Source: PG Environmental, November, 2021
PEM = Palustrine emergent, TRF = Tijuana River floodplain
Figure 3-3. Aquatic Resources Near the Proposed Action in the U.S. (1 of 7)
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Final Programmatic EIS: USMCA Mitigation of
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Tijuana River Floodplain
Aquatic Resources
Legend
Delineation Area
Jurisdiction
Waters WOTUS WOS CCC
Wetland CCC
500
1,000
I Feet
150
300
HI Meters
1 inch = 417 feet
Spatial Reference
PCS: NAD 1983 2011 StatePlane California VI FIPS 0406
GCS: GCS NAD 1983 2011
Datum: NAD 1983 2011
Imagery source: Digital Globe G-EGD
Imagery date: 11/05/2021
Data Source: PG Environmental, November, 2021
PEM = Palustrine emergent, TRF = Tijuana River floodplain
Figure 3-4. Aquatic Resources Near the Proposed Action in the U.S. (2 of 7)
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Final Programmatic EIS: USMCA Mitigation of
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Tijuana River Floodplain
Aquatic Resources
£#X*X*X*X*X*X#X*X*X#XwX*X#X*X*Xv
iiX'X'XwXwX^XvXwXwXw
feflfrX+X+X+X+X*X+X+X+X+X*X+X+X+X
^^~x*x*x*x*x*x*x*x*x*x*x*x*
IKvX*X*X*X*X*X»XvX*XvXv
>X»XwXwXwX\?X*X*Xv<
HMMM
Legend
Delineation Area
Jurisdiction
Waters WOTUS WOS CCC
Wetland CCC
500
1,000
I Feet
150
300
HI Meters
1 inch = 417 feet
¦Jpttggi
vWf?-:
<: * h."
•'v-
•5*-. u>4.
issss ii a«i i
SlbaiSali Ifeilt M
Spatial Reference
PCS: NAD 1983 2011 StatePlane California VI FIPS 0406
GCS: GCS NAD 1983 2011
Datum: NAD 1983 2011
Imagery source: Digital Globe G-EGD
Imagery date: 11/05/2021
Data Source: PG Environmental, November, 2021
PFO = Palustririe forested, PSS = Palustrine scrub-shrub, TRF = Tijuana River floodplain
Figure 3-5. Aquatic Resources Near the Proposed Action in the U.S. (3 of 7)
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Final Programmatic EIS: USMCA Mitigation of
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Legend
Delineation Area
Jurisdiction
R88I Waters WOTUS WOS CCC
fTTTTT' Waters WOS CCC
Wetland CCC
2-foot Concrete Channel*
0 500 1,000
^ I Feet
150 300
I Meters
1 inch = 417 feet
Spatial Reference
PCS: NAD 1983 2011 StatePlane California VI FIPS 0406
GCS: GCS NAD 1983 2011
Datum: NAD 1983 2011
Imagery source: Digital Globe G-EGD
Imagery date: 11/05/2021
Data Source: PG Environmental, November, 2021
Border Swale/Clearwater
Road Aquatic Resources
N
s
BS = border swale, PEM = Palustrine emergent, PSS = Palustrine scrub-shrub, TRF = Tijuana River floodplain
Figure 3-6. Aquatic Resources Near the Proposed Action in the U.S. (4 of 7)
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Final Programmatic EIS: USMCA Mitigation of
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Legend
Delineation Area
Jurisdiction
Waters WOTUS WOS CCC
2-foot Concrete Channel
Monument Road/Dairy
Mart Road Aquatic
Resources
N
500 1,000
M I Feet
150 300
M i Meters
1 inch = 417 feet
Spatial Reference
PCS: NAD 1983 2011 StatePlane California VI FIPS 0406
GCS: GCS NAD 1983 2011
Datum: NAD 1983 2011
Imagery source: Digital Globe G-EGD
Imagery date: 11/05/2021
Data Source: PG Environmental, November, 2021
MR = Monument Road
Figure 3-7. Aquatic Resources Near the Proposed Action in the U.S. (5 of 7)
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Legend
Delineation Area
Jurisdiction
Waters WOTUS WOS CCC
Wetland WOTUS WOS CCC
Smuggler's Gulch
Aquatic Resources
N
S
500 1,000
M I Feet
150 300
M i Meters
1 inch = 417 feet
Spatial Reference
PCS: NAD 1983 2011 StatePlane California VI FIPS 0406
GCS: GCS NAD 1983 2011
Datum: NAD 1983 2011
Imagery source: Digital Globe G-EGD
Imagery date: 11/05/2021
Data Source: PG Environmental, November, 2021
SG = Smuggler's Gulch
Figure 3-8. Aquatic Resources Near the Proposed Action in the U.S. (6 of 7)
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Final Programmatic EIS: USMCA Mitigation of
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Legend
Delineation Area
Jurisdiction
Waters WOTUS WOS CCC
Goat Canyon Aquatic
Resources
N
W^E
S
500 1,000
M I Feet
150 300
M i Meters
1 inch = 417 feet
Spatial Reference
PCS: NAD 1983 2011 StatePlane California VI FIPS 0406
GCS: GCS NAD 1983 2011
Datum: NAD 1983 2011
Imagery source: Digital Globe G-EGD
Imagery date: 11/05/2021
Data Source: PG Environmental, November, 2021
GC = Goat Canyon
Figure 3-9. Aquatic Resources Near the Proposed Action in the U.S. (7 of 7)
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Table 3-3. Wetlands Mapped Within the Evaluated Areas
Namea
Cowardin Classification
Size
(acres)
Length
(linear
feet)
Average
Width
(feet)
Jurisdiction
Wetland Waters
PEM Wetland 1
Palustrine Emergent
1.00
N/A
N/A
USACE, state, CCC
PSS Wetland 2
Palustrine Scrub-Shrub
1.58
N/A
N/A
CCC
PFO Wetland 3
Palustrine Forested
2.56
N/A
N/A
CCC
PSS Wetland 4
Palustrine Scrub-Shrub
2.14
N/A
N/A
CCC
PEM Wetland 5
Palustrine Emergent
0.23
N/A
N/A
CCC
PSS Wetland 6
Palustrine Scrub-Shrub
0.07
N/A
N/A
CCC
SG Wetland
Palustrine Scrub-Shrub
0.98
N/A
N/A
USACE, state, CCC
Total Wetlands
8.56
N/A
N/A
Non-Wetland Waters and Other Waters
TRF
Riverine-Intermittent (R4)
117.85
7,899
444.8
USACE, state, CCC
Stewart's Drain
Riverine-Intermittent (R4)
1.63
609
177.3
USACE, state, CCC
SG Waters
Riverine-Intermittent (R4)
1.40
1,342
44.0
USACE, state, CCC
GC Main
Riverine-Intermittent (R4)
0.73
694
50.2
USACE, state, CCC
GCTrib 1
Riverine-Intermittent (R4)
0.01
32
3.0
USACE, state, CCC
MRTrib 1
Riverine-Intermittent (R4)
0.01
27
3.5
USACE, state, CCC
MRTrib 2
Riverine-Intermittent (R4)
0.01
26
7.5
USACE, state, CCC
Clearwater Swale 1
Riverine-Intermittent (R4)
0.08
213
15.8
USACE, state, CCC
Clearwater Ditch 1
Riverine-Intermittent (R4)
0.01
23
6.5
State, CCC
BS Ditch 1
Riverine-Intermittent (R4)
0.34
152
18.8
State, CCC
BS Ditch 2
Riverine-Intermittent (R4)
0.02
880
4.5
State, CCC
Total Waters
122.09
11,897
Other Features
Concrete channels
N/A
0.05
N/A
2
N/A
Total Other Features
0.05
a - PEM = Palustrine emergent, PSS = Palustrine scrub-shrub, PFO = Palustrine forested, TRF = Tijuana River
floodplain, GC = Goat Canyon, SG = Smuggler's Gulch, MR = Monument Road, BS = border swale.
3.1.2 Surface Water Quality
Water quality in the Tijuana River is regulated by the federal government under the CWA and by
the state government under the Porter-Cologne Act, which are described in more detail in Section
6.1.2 (Surface Water Quality).
The San Diego Regional Water Quality Control Board (SDRWQCB, or San Diego Water Board) has
published a Basin Plan that establishes five points of its water quality management policy, which
include goals for identifying and maintaining water quality objectives and beneficial uses. One of
these policies specifies that "point sources and nonpoint sources of pollution shall be controlled to
protect designated beneficial uses of water." Municipal and industrial point sources are required to
meet treatment levels at least as stringent as those defined in the CWA, and nonpoint sources are
required to be controlled in accordance with the CWA and the Coastal Zone Act Reauthorization
Amendments (SDRWQCB, 2016). Beneficial uses are defined as water uses necessary for the
survival or well-being of humans, plants, and wildlife (SDRWQCB, 2016). The Tijuana River
watershed has the following beneficial uses:
• Tijuana Estuary Natural Preserve, the TRNERR, and the Tijuana Slough NWR have beneficial
uses for the preservation of biological habitats of special significance.
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• Smuggler's Gulch and Goat Canyon have beneficial uses of non-contact water recreation,
warm freshwater habitat, and wildlife habitat.
• The main channel of the Tijuana River in the project area has beneficial uses of non-contact
water recreation; preservation of biological habitats of special significance; warm
freshwater habitat; wildlife habitat; and rare, threatened, or endangered species.
• The Tijuana River Estuary has beneficial uses of contact water recreation; non-contact
water recreation; commercial and sport fishing; preservation of biological habitats of
special significance; estuarine habitat; wildlife habitat; rare, threatened, or endangered
species; marine habitat; migration of aquatic organisms; spawning, reproduction, and/or
early development; and shellfish harvesting (SDRWQCB, 2016).
The Tijuana River is a CWA Section 303(d) impaired water body for the following: trash; solids;
sedimentation/siltation; nutrient-related issues (specifically ammonia as Nitrogen, total nitrogen as
N, phosphorus, low dissolved oxygen, and eutrophication); benthic community effects; indicator
bacteria; toxicity; pesticides (e.g., chlorpyrifos, diazinon, malathion); surfactants; synthetic
organics; and trace elements (e.g., cadmium, selenium) (SWRCB, 2018). The Tijuana River Estuary
is a CWA Section 303(d) impaired water body for the following: trash, turbidity, nutrient-related
issues (specifically, low dissolved oxygen and eutrophication), indicator bacteria, toxicity,
pesticides, lead, nickel, and thallium (SWRCB, 2018). Total Maximum Daily Load (TMDL) is a
management tool used to identify and regulate pollutant loads to impaired waters. The San Diego
Water Board has initiated efforts to establish a TMDL for indicator bacteria and trash in the Tijuana
River and Estuary, with adoption expected in early 2023 (SWRCB, 2022).
Dry-weather flows in the main channel of the Tijuana River south of the border (i.e., upstream)
typically range between 20 to 30 MGD, including approximately 10 MGD of treated effluent from La
Morita WWTP and Arturo Herrera WWTP and 4 to 5 MGD of flows from the Alamar River that
mostly consist of treated effluent from Tecate. The remainder consists of urban runoff into storm
drains and untreated wastewater that escapes the City of Tijuana's sanitary collection system. IBWC
conducted a water quality study with samples collected from December 2018 to November 2019 at
eight sites in the Tijuana River and its tributary canyons and drains and analyzed for a wide range
of parameters. Based on the available data, current dry-weather transboundary flows in the Tijuana
River are estimated to contain 100 mg/L BODs on average and to convey an average of 1,590 tons
per year (tons/yr) of BOD5 into the U.S. (PG Environmental, 202 lg).
3.1.2.1 Sediment
The Tijuana River watershed experiences substantial erosion during storm events, resulting in
elevated sediment concentrations in the river and extensive sediment deposition within the Tijuana
River Valley in the U.S. The combination of rapid urbanization in Tijuana and persistent soil
exposure on steep slopes results in erosion that produces large volumes of sediment, which are
transported into the watershed stream network (Nordby, 2018; URS, 2010; USACE, 2020). The
upstream dams collectively help to reduce sediment loading in downstream portions of the river.
Additional factors include sediment contributions from dirt roads and walking and horse trails. As
the City of Tijuana develops, its roadways often remain unpaved, and they may erode and be
repaired every year, contributing substantial volumes of sediment to the river in the process (Biggs
et al., 2010; TRNERR, 2014). There are also several informal trails north of the U.S.-Mexico border
used by CBP, although their use is discouraged for restoration purposes (Nordby, 2018). Dirt roads
within the TRNERR could also contribute to sediment loading (TRNERR, 2014).
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Much of this transboundary sediment in the river is deposited before it reaches the mouth of the
Tijuana River Estuary. The most substantial sediment deposition occurs in the USACE-constructed
basin between the U.S.-Mexico border and Dairy Mart Road Bridge; downstream of this section,
sediment scouring and erosion are more prominent until discharge via the estuary to the Pacific
Ocean (Stantec, 2020a; USACE, 2018). The amount of sediment ultimately discharged into the
Pacific Ocean is likely more related to the river's ability to scour the lower portions of the estuary,
rather than to the watershed sedimentyield (USACE, 2018). Sediment deposition spikes in months
with the most precipitation (USACE, 2018).
A substantial proportion of sediment in the river is deposited along the floodplain in the estuary
due to its flatter surface, width, and dense vegetation that can restrict sediment movement. The
accumulated sediment reduces the flow capacity of the river and promotes the establishment of
more vegetation, which combine to cause additional flooding and deposition of sediment and trash
in the estuary (Tijuana River Valley Recovery Team, 2012). The majority of sediment transported
by the river is carried during storm and flood events; moderate flood events can deposit sediment
in the portions of the estuary such as mudflats, raising elevations and reducing intertidal areas,
while the largest flood events can scour out mudflats and tidal channels and carry sediment all the
way to the ocean (SFEI, 2017). During a 100-year storm event, the sediment flow capacity in the
river immediately downstream of the U.S.-Mexico border can be as high as 1,821,000 tons per day,
and as much as 73 percent of the sediment load to the Tijuana River is deposited in its overbank
(HDR, 2020b; USACE, 2018). Based on available data on sediment concentrations, river flow rates,
and precipitation, the sediment load in transboundary river flows during the four-year period
between 2016 and 2019, including large storm events, is estimated to be 187,000 tons/yr (PG
Environmental, 202 If; USACE, 2020). On average, an estimated 49,000 tons/yr of this sediment is
deposited within the Tijuana River Valley, primarily upstream of Hollister Street (PG
Environmental, 2021d; USACE, 2020).
Transboundary flows in the canyon tributaries along the U.S.-Mexico border also convey substantial
amounts of sediment to the Tijuana River Valley and Estuary. Smuggler's Gulch frequently
experiences high sedimentation rates during storms due to erosion and trash accumulation in its
subwatershed. The City of San Diego periodically clears out sediment that accumulates in the
Smuggler's Gulch channel and the downstream Tijuana River pilot channel, both of which require
sediment removal for the other to work properly (HDR, 2020c). In late 2020, CESPT constructed a
basin and weir to detain stormwater and trap sediment and trash in Matadero Canyon; this
structure is reportedly effective at reducing trash in transboundary stormwater flows into
Smuggler's Gulch. California State Parks maintains sediment basins in Goat Canyon to prevent
sediment deposition in wetlands of the Tijuana River Valley and Estuary. The basins have been
reported to catch the first flush of sediment during a wet-weather event (HDR, 2020b). In
November 2004, the basins were filled and breached during a storm event before construction was
completed, and up to 2 feet of sediment was discharged across approximately 2 0 acres of wetland
west of Monument Road (Nordby, 2018).
3.1.2.2 Bacteria
Bacterial contamination is also a concern in the Tijuana River, although most studies have focused
on bacterial concentrations in the estuary and coastline and the related beach closures as discussed
in Section 3.2 (Marine Waters). High concentrations of bacteria can be indicative of pathogens that
are harmful to human health, so water quality monitoring may attempt to quantify indicator
bacteria such as total coliforms, fecal coliforms, Enterococci, and E. coli (IBWC, 2020).
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Some studies have documented high concentrations of fecal indicator bacteria (FIB) in the Tijuana
River Valley. CBP conducted a six-month monitoring program in the main channel of the Tijuana
River near the U.S.-Mexico border and in the canyon flow diversion structures at Smuggler's Gulch
and Goat Canyon. CBP identified elevated levels of FIB, indicating that transboundary flows include
untreated domestic discharges (HDR, 2020a). IBWC measured high concentrations of FIB at the
same locations and concluded that the presence of coliform bacteria in particular was likely due to
non-point source pollution from the City of Tijuana's sewage system (IBWC, 2020). In another
study, researchers found that Goat Canyon sediment contained concentrations of Enterococcus that
exceeded acceptable public health standards (Nordby, 2018).
3.1.2.3 Trash
Trash in the Tijuana River Valley tends to accumulate along channels and in areas with vegetation
or other physical barricades, where it can contribute to human health concerns and diminish
aesthetics (HDR, 2020c; URS, 2010). See Section 3.13 (Solid and Hazardous Waste) for discussion of
trash accumulation in the river and project areas and Section 3.16 (Public Health and Safety) for
discussion of the public health implications of trash in the river.
3.1.2.4 Other Pollutants
As described earlier in this section, the Tijuana River and the Tijuana River Estuary are CWA
Section 303 (d)-impaired water bodies for additional parameters of concern that could have
harmful impacts on wildlife and human health. Pollutants contributing to these impairments
include nutrients (e.g., nitrogen, phosphorus), pesticides (e.g., chlorpyrifos, diazinon, malathion),
surfactants, synthetic organics, cadmium, lead, nickel, selenium, and thallium. These pollutants may
be introduced by untreated wastewater from the City of Tijuana, non-point source storm water
runoff throughout the watershed, or from agricultural activities in upstream portions of the Tijuana
River watershed (HDR, 2020a).
Other pollutants of concern in the Tijuana River can have various deleterious impacts on wildlife
and human health, as described below:
• Excessive nutrient concentrations (such as nitrate, ammonium as nitrogen, and
phosphate) can cause eutrophication, which is an enrichment of nutrients that promotes
excessive algal growth. Eutrophication can lead to hypoxia in the water column when algae
die and decompose, possibly resulting in a fish kill, and contribute to formation of harmful
algal blooms (HABs) that can sicken wildlife and humans (NOAA, 2021b).
• Pesticides (a type of synthetic organic compound) can have a range of human health
impacts, depending on the type of pesticide. They may irritate skin or eyes, affect the
nervous or endocrine systems, or act as carcinogens (EPA, 2017).
• Surfactants (including detergents and foaming agents) can be toxic for aquatic species and
may form persistent degradation products (EPA, 2021c).
• Cadmium can readily bioaccumulate in aquatic organisms, especially mollusks, soil
invertebrates, and microorganisms (WHO, 1992). Cadmium contamination can lead to
skeletal malformations in fish (WHO, 1992), and cadmium is a probable human carcinogen
(ATSDR, 2012).
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Final Programmatic EIS: USMCA Mitigation of
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• Lead contamination can delay embryonic development; suppress reproduction; and inhibit
growth in fish, crab, and several other aquatic organisms (EPA, 1984). Lead is also a potent
neurotoxin in humans (EPA, 2014; National Toxicology Program, 2012).
• Nickel can inhibit the growth of microorganisms (e.g., bacteria, protozoans) and algae
(Eisler, 1998; EPA, 1986). Nickel toxicity can reduce fish growth and adversely impact the
immune system, muscles, gills, and liver in fish and gastropods (Eisler, 1998; EPA, 1986;
Min et al., 2015). In humans, nickel can have adverse effects on the blood and kidneys
(ATSDR, 2005).
• Selenium bioaccumulates in the food web. High concentrations in fish may lead to
reproductive impairments and larval mortality (EPA, 2016a). In humans, chronic oral
exposure can lead to selenosis, which produces hair loss and neurological abnormalities
(ATSDR, 2003). Acute exposure to elemental selenium via inhalation or oral consumption
can adversely impact the respiratory, cardiovascular, gastrointestinal, and neurological
systems (ATSDR, 2003; EPA, 2000). Selenium maybe carcinogenic (Vinceti etal., 2017).
• Thallium bioaccumulates in aquatic organisms, possibly presenting a hazard for organisms
at higher trophic levels (EPA, 2011). Thallium can lead to deleterious effects on the nervous
system, lungs, heart, liver, and kidneys in humans from short-term exposure to high doses.
Ingestion of as little as 1 gram of thallium can be lethal to humans (ATSDR, 2015). There is
no definitive conclusion on long-term effects of thallium exposure in humans (ATSDR,
2015).
3.1.3 Stormwater Management
Stormwater discharges are regulated at the federal level under the CWA Section 402 NPDES
program and the Energy Independence and Security Act (EISA); at the state level under several
permitting requirements; at the regional level under the Regional Municipal Separate Storm Sewer
System (MS4) Permit (NPDES NO. CAS0109266); and at the county level under the County of San
Diego's Watershed Protection, Stormwater Management, and Discharge Control Ordinance. The
County of San Diego BMP Design Manual provides guidance for land development and
improvement projects to comply with the Regional MS4 Permit and with the county's Watershed
Protection, Stormwater Management, and Discharge Control Ordinance. Specifically, this manual
provides guidance on compliance with project design requirements and post-construction
requirements (County of San Diego, 2020c). In the City of San Diego, the Stormwater Standards
Manual provides stormwater guidance for development projects (City of San Diego, 2018b). See
Section 6.1.2 (Stormwater Management) for additional discussion of regulatory and permitting
requirements.
The City of San Diego's MS4 runs throughout the city and includes drains, pipes, and engineered
channels (City of San Diego, 2020d). As described in Section 3.2 (Marine Waters), previous studies
have found that MS4 discharges are not a notable source of contamination in the Tijuana River.
Runoff from the ITP is conveyed via stormwater drains to the river. Runoff in the undeveloped
southwest quadrant of the ITP parcel flows toward the river through a swale that runs generally
northwest alongside the developed portion of the ITP parcel and through an outfall to the river.
See Section 3.1.1 (Hydrology) above for discussion of transboundary stormwater flows and related
infrastructure in the Tijuana River and tributary canyons.
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Final Programmatic EIS: USMCA Mitigation of
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3.1.4 Groundwater and Drinking Water
The Tijuana Groundwater Basin, also known as the Lower Tijuana River Valley Basin, overlies a
portion of the broader Coastal Plain of San Diego confined aquifer and is roughly coterminous with
the Tijuana River Valley (City of San Diego, 2016b). The basin is managed by the San Diego County
Water Authority and the California American Water Company but is not currently used as a
drinking water source. The Tijuana Groundwater Basin has multiple barriers to use, including
saltwater intrusion, exceedances of maximum contaminant levels for multiple pollutants, and
contamination from sewage and untreated industrial discharges to the river (City of San Diego,
2016b). The Tijuana Groundwater Basin is not considered to be a major source of recharge to the
San Diego coastal plain aquifer, the source of public water supply for the San Diego area. Rather,
recharge occurs in regions of the San Diego basin to the east of the Tijuana River Valley that have
higher elevation and more consolidated rock types (Flint et al., 2012). Groundwater from the
Tijuana Groundwater Basin may be a source to surface flows in the Tijuana River (HDR, 2020a).
Discussion of groundwater interactions with surface flows can be found in Section 3.1.1
(Hydrology).
Historically, groundwater in the valley was high in the estuarine areas and supported an extensive
alkali meadow complex habitat Perennial pools were formed from groundwater in areas carved out
by scouring from floods. However, groundwater extraction in the Tijuana River Valley increased
during periods of agricultural development, most recently peaking in the mid-2 0th century. By
1960, groundwater levels had dropped below sea level, leading to saltwater intrusion and increases
in groundwater salinity. The increased salinity resulted in shutdown of most of the agricultural
activity in the Tijuana River Valley, leading to a gradual recovery of groundwater levels. By the
1970s, the water table in the valley generally had recovered to close to historical levels (SFEI,
2017). Groundwater from the Tijuana Groundwater Basin continues to be used for irrigation of the
USIBWC-owned sod farm at a rate of approximately 360 to 480 acre-feetper year (ac-ft/year) (M.
Williams [West Coast Turf], personal communication, January 4, 2022), but it is unknown whether
any other irrigation practices in the Tijuana River Valley continue to rely on this groundwater
source.
Groundwater data found in the USGS National Water Information System Mapper shows that most
wells in the Tijuana River Valley have been inactive for several decades. However, two shallow
wells of 90 and 142 feet deep (site names: 019S002W03E001S and 019S002W03E002S,
respectively) immediately east of Hollister Street and approximately 350 feet south of the pilot
channel, report groundwater level data from 2010 to 2019. The USGS well data show a general
trend of drawdown from 2010 to 2014, followed by slight recovery and significant seasonal
variation, including significant recoveries during the 2010 to 2011, 2016 to 2017, and 2018 to 2019
wet seasons (USGS, 2022).
Examination of natural groundwater inflows and outflows provides the basis for estimating the
Natural Safe Yield of the Tijuana Groundwater Basin. Natural Safe Yield is defined as the amount of
groundwater that can be used from an aquifer without long-term effects on the volume of
groundwater and groundwater levels in the aquifer. In support of permitting for the ITP, the
USIBWC estimated the Natural Safe Yield to be 5,500 to 6,000 ac-ft/year (USIBWC, 1976). A more
recent study estimated the Natural Safe Yield to be 5,000 to 6,800 ac-ft/year (Metropolitan Water
District of Southern California, 2007). If this water is not extracted, it will eventually flow into the
Pacific Ocean through a combination of surface flow via the Tijuana River and subsurface flow. The
substantial increase in dry-weather transboundary flows in the Tijuana River in recent years (see
Figure 1-6) would be expected to provide additional recharge to the alluvial aquifer, suggesting that
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the current Natural Safe Yield of the Tijuana Groundwater Basin could be greater than the estimates
shown above.
Depths to groundwater can be influenced by rainfall, topography, geological stratification, flooding,
and groundwater removal (Stantec, 2019). During field excavation in the sediment basin along the
main stem of the Tijuana River upstream of Dairy Mart Road, groundwater was encountered at 6
feet below ground surface (bgs), equivalentto 33 feet above mean sea level (MSL) (Stantec, 2019).
In another excavation in the same area, groundwater was first encountered between approximately
6 and 15 feet bgs (URS, 2010). Within the ITP parcel, a geotechnical study for the recently
constructed equalization tanks encountered groundwater at 28.5 feet bgs, equivalentto 26 feet
above MSL, while previous explorations at the site encountered groundwater at elevations ranging
between 29 and 37 feet above MSL (URS, 2015).
The City of San Diego purchases the majority of its water from the Colorado River and northern
California (City of San Diego, 2020c). Based on available information, there is no evidence that the
Tijuana River is currently used as a drinking water resource. No sole source aquifers or drinking
water wells exist in the area. In 2021, the city launched the Pure Water San Diego project, a multi-
year water infrastructure capital improvement program to increase local water supply and reduce
dependence on imported water. The program aims to provide nearly half of the city's drinking
water by 2035 through water reuse and recycle (City of San Diego Public Utilities, 2022).
Recent archeological investigations in Smuggler's Gulch identified a capped artesian well and debris
from a spring water bottling company that operated in the 1900s (see Appendix C). The Goat
Canyon area may have had an artesian well that provided drinking water, according to a historical
ecology study summarizing conditions in the estuary from 1976 to 2016 (Nordby, 2018). In other
parts of the watershed, potable water may have been drawn from Moreno Reservoir and Barrett
Lake, which are much farther upstream in the watershed. However, it appears that this may have
ceased due to ongoing drought in recent years (City of San Diego, 2020d).
3.1.5 Recreational and Commercial Uses
The TRNERR, Tijuana Slough NWR, Tijuana River Valley Regional Park, and Border Field State Park
offer recreational opportunities surrounding the river and estuary. Fishing is not allowed in the
NWR, and Border Field State Park recommends against swimming or wading in the ocean due to
hazardous conditions offshore (CDPR, USFWS, &NOAA, 2010).
The Tijuana River Estuary has been used for recreational shell fisheries and commercial bait
fisheries in the past, but fishing is no longer allowed in the TRNERR. Fisheries within the NWR are
located on state tidal lands and operate under California State Land Commission Lease No. Public
Resources Code (PRC) 5938.9 (CDPR, USFWS, & NOAA, 2010).
3.2 Marine Waters
3.2.1 Physical Oceanography of Southern California
Along the Pacific Ocean coast in southern California, the southward California Current is the
dominant oceanic circulation pattern. It flows adjacent to the continental shelf and moves eastward
toward the coast near San Diego (Dailey et al., 1993). Seasonal countercurrents flow northward
inshore of the California Current during the summer, fall, and winter (Kaplan et al., 2010).
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The physical oceanography of coastal waters influences the transport and dispersion of Tijuana
River discharges to the ocean. Depending on environmental conditions, a large area of
counterclockwise circulation (eddy) extends south from Point Loma. According to radar
measurements, this eddy is frequently located to the west of the SBOO or centered near the outfall.
There may also be a smaller counterclockwise eddy south of Point Loma. These circulations are
dependent on tides and diurnal (i.e., day-night) wind patterns (Largier et al., 2004). Water
movement in the shallower nearshore regions is affected by the circulation patterns farther
offshore, as well as tidal- and wave-driven currents (Largier et al., 2004). The flow rate of discharge
from the Tijuana River is expected to determine whether the outflow is entrained in the nearshore
region or pass through to areas farther offshore (Largier etal., 2004).
The San Diego region experiences a mixed semidiurnal tide consisting of two high and two low
tides of different magnitudes (Jay & Largier, 2003). The water column is typically stratified to a
depth of approximately 20 meters from May to October (Dailey et al., 1993). Seasonal upwelling
along the California coast from March to July also impacts water quality conditions, although
upwelling has been less pronounced in recent decades as the water temperature has increased.
Upwelling occurs in response to currents and wind and causes deep, cold water, typically with more
nutrients and less dissolved oxygen, to move to the surface (Kaplan et al., 2010).
3.2.2 Marine Water Quality
Physical and chemical water quality conditions in the ocean offshore of San Diego have been
established through previous monitoring. Surface water temperatures are generally 19 °C from July
to September, decreasing to approximately 14.5 °C in winter (Dailey etal., 1993). Temperature
decreases deeper in the water column, to as low as approximately 10 °C in the winter (City of San
Diego, 2020a). Nearshore salinity is between 33 and 34 parts per thousand, with slightly lower
salinity in the spring (Dailey et al., 1993). Dissolved oxygen varies from approximately 3 to 12
mg/L, with higher values in the spring and summer, while pH values range from approximately 7.7
to 8.4 (City of San Diego, 2020a).
The Pacific Ocean along the Tijuana River Valley coastline receives flow from the Tijuana River
itself, as well as discharges from point sources including the SABTP (and related discharges) to SAB
Creek in Mexico, the SBOO near the international border, and the Point Loma Ocean Outfall (PLOO)
near the Port of San Diego. Each of these sources has the potential to influence marine water
quality. In Mexico, the approximately 35.5 MGD of mixed Tijuana River water and wastewater are
discharged into the Pacific Ocean via SAB Creek at Punta Bandera. Shoreline sampling, dye studies,
and models have demonstrated that nearshore currents can transport contaminants in these
discharges up to 20 kilometers northward (Feddersen etal., 2021). The SBOO, operated and
maintained by the City of San Diego, discharges treated effluent from the ITP and SBWRP to the
Pacific Ocean at a distance of 3.5 miles offshore at 90 feet below sea level. Discharge from the ITP
has been sent to the SBOO since 1999 (City of San Diego, 2020a).
Beaches in the County of San Diego are regularly required to close due to untreated wastewater
discharges to the Pacific Ocean via SAB Creek and the Tijuana River. As discussed in Section 1.3.2
(Impacts of Contaminated Transboundary Flows), poor coastal water quality has contributed to
frequent beach closures in southern San Diego County. The City of Imperial Beach routinely
struggles with elevated bacteria levels that result in beach closures. The beaches at Imperial Beach
Pier and Border Field State Park have averaged 66 and 170 closure days per year since 2003,
respectively, with even more frequent closures at Border Field State Park in recent years
(averaging 262 closure days per year since 2019) (City of Imperial Beach, 2022). The County of San
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Diego monitors the ocean water for FIB and closes beaches if the FIB concentration exceeds the
threshold estimated to result in 32 illnesses per 1,000 primary contact recreators (known as the
EPA beach action value). In May 2022, the County of San Diego became the first community in the
U.S. to begin using a digital droplet polymerase chain reaction (ddPCR) method for routine water
quality monitoring of bacteria at beaches (SCCWRP, 2022). This new method provides same-day
results in as little as three hours, significantly faster than traditional culture-based methods which
typically took 24 to 72 hours for results (SCCWRP, 2022). As a more sensitive and efficient method
than culture-based methods, ddPCR testing revealed higher bacteria concentrations than previous
testing, resulting in more beach closures or posted signage warning beachgoers of potential water
contamination (Dias, 2022; Elmer, 2022a, 2022b). Unlike culture-based testing, ddPCR testing can
detect damaged and dead bacteria, both of which can still make people ill (Dias, 2022).
During wet-weather conditions, high flows in the Tijuana River transport polluted water and trash
to the Imperial Beach shoreline (City of Imperial Beach, 2019). Segments of the Pacific Ocean
shoreline near the mouth of the Tijuana River are impaired for bacteria and other microbes, per
CWA Section 303(d) listings from 2016 (EPA, 2021a). According to a multi-year study of the Tijuana
River watershed, 99 percent of the indicator bacteria entering the Pacific Ocean from the watershed
during wet weather originate from Mexico, rather than from other sources such as municipal
stormwater discharges in the U.S. (Weston Solutions, Inc, 2012). A recent modeling study by the
Scripps Institution of Oceanography indicated that, while discharges via the Tijuana River and SAB
Creek are contributors, discharges via SAB Creek are the predominant cause of modeled beach
impacts21 at Imperial Beach during the tourist (dry) season (Feddersen etal., 2021).
Additionally, nutrient loadings from the Tijuana River watershed could contribute to the formation
of HABs along the coastline. In California, HAB events are often related to large-scale oceanographic
forcing, although studies have shown that local nutrient inputs are important when cells reach the
shore. Effluent and riverine discharges may contribute more than 82 percent of the annual nitrogen
input in the San Diego area (Howard etal., 2014). Howard etal. (2014) evaluated the sources of
nitrogen loadings to nearshore coastal ecosystems in highly urbanized areas of southern California.
They reported that wastewater discharges contribute similar amounts of nitrogen as wind-driven
up welling events, with wastewater contributions in the Tijuana River coastal area being nearly an
order of magnitude higher than inputs from upwelling. Howard et al. (2014) estimate that
upwelling contributes approximately 2,700 tons/yr of nitrogen in the San Diego area and that
effluent, riverine runoff and atmospheric deposition contribute approximately 15,500 tons/yr of
nitrogen. It is unclear if Howard etal. (2014) included an estimate of nitrogen flux to the area from
SAB Creek. SAB Creek contributes approximately 4,000 tons of nutrients to the Pacific Ocean under
current conditions Table 4-6, although this discharge does not reach the California coast unless
south swell conditions drive the plume northward. However, the magnitude of nitrogen enrichment
suggests it is a substantial source of nitrogen to the marine environment in the region and therefore
may be contributing to increased HABs. It is unclear whether SBOO discharges influence the
frequency or magnitude of HABs in the San Diego area. However, it seems highly likely that
contributions of coastally trapped raw effluent discharged from SAB Creek do contribute to an
21 The cited study by the Scripps Institution of Oceanography estimates the "beach impact fraction" at four
beach locations, including Imperial Beach, under varying discharge scenarios from the Tijuana River and SAB
Creek. In this study, beach impact fraction is defined as the fraction of time that the modeled mean (expected)
probability of swimmer illness exceeds 0.0036 (i.e., 36 per 1,000) due to exposure to norovirus pathogens in
untreated wastewater discharges.
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increased likelihood of HAB events. Based on satellite imagery and water quality data, the presence
of HAB events offshore of San Diego often seems to correlate with Tijuana River discharges (Ocean
Imaging, 2021).
Through analyzing remote sensing data, researchers have found that satellite data can be used to
characterize stormwater and wastewater plumes in the Tijuana River Estuary and along the coast
(Ayad et al., 2020). These researchers noted that stormwater has higher turbidity than wastewater,
and that flow rates were highest for stormwater and lower for wastewater. It may be possible to
use specific statistical analyses to discern the two types of plumes, increasing the chances that
researchers can identify plume behavior and better predict the influence of discharges from the
river in the future (Ayad et al., 2020).
Limits on discharges to marine receiving waters are regulated under the CWA Section 402 NPDES
program and are informed by the National Recommended Water Quality Criteria (NRWQC). See
Section 6.1.3 (Marine Waters) for details about regulatory requirements for discharges.
The State Water Resources Control Board (SWRCB), part of the California Environmental Protection
Agency (CalEPA), publishes water quality standards and methods for selecting assessment
thresholds in a document entitled A Compilation of Water Quality Goals. This document references
the NRWQCs as a metric that can be used to establish aquatic life protective numeric thresholds for
toxicity in ocean waters (SWRCB, 2016).
The California Ocean Plan has been adopted by the SWRCB as part of its Water Quality Control Plan.
The California Ocean Plan is intended to protect the quality of ocean waters for public use and
enjoyment by controlling discharge of waste to ocean waters and intake of seawater. The California
Ocean Plan therefore regulates discharges to the ocean from point source discharges such as the
SBOO (SWRCB, 2019). The California Ocean Plan identifies water quality objectives, which include
standards for bacterial, physical, chemical, and biological characteristics, as well as radioactivity. It
also provides water quality objectives for protection of marine aquatic life (based on six-month
median, daily maximum, and instantaneous maximum limiting concentrations) and protection of
human health from carcinogens and non-carcinogens (based on 30-day average limiting
concentrations).
RWQCBs develop Water Quality Control Plans to establish water quality standards for certain
bodies of water and their tributaries (SWRCB, 2016). The Water Quality Control Plan of the San
Diego Basin provides water quality objectives for dissolved oxygen and pH in ocean water
(SDRWQCB, 2016).
The NPDES permits for SBOO discharges from the SBWRP (CA0109045) and the ITP (CA0108928)
include both technology-based effluent limitations (TBELs) and water quality-based effluent
limitations (WQBELs). WQBELs are in place for non-conventional and toxic pollutants, as listed in
the California Ocean Plan (SWRCB, 2019). The NPDES permits were written to comply with the
California Ocean Plan and the Water Quality Control Plan of the San Diego Basin.
Both USIBWC and the City of San Diego conduct monitoring pursuant to the terms of the SBOO
NPDES permits. USIBWC monitors water quality along the Pacific Ocean coastline to comply with its
NPDES permit for the ITP. As part of its monitoring program for the SBOO and PLOO, the City of San
Diego Public Utilities monitors water quality, benthic characteristics, demersal fishes and
invertebrates, and bioaccumulation of contaminants in fishes. They assess 60 locations for the
SBOO and 82 for the PLOO, located along the shore to offshore at depths of approximately 200 feet
(City of San Diego, 2020a). Water quality conditions at their testing sites are expected to be
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influenced by oceanographic currents, as well as point and non-point source pollution. Recent
monitoring results show no evidence that treated effluent plumes from the SBOO and the PLOO are
reaching nearshore waters (City of San Diego, 2020a). The City of San Diego Public Utilities also
participates in a periodic regional monitoring program that measures a broader suite of
parameters, such as habitats. Based on plume dispersion monitoring, there was no evidence that
effluent from either outfall impacted shoreline water quality. The PLOO and SBOO generally
complied with the California Ocean Plan based on monitoring at shoreline, kelp forest, or offshore
locations (City of San Diego, 2020a).
3.2.3 Recreational and Commercial Uses
The State of California established the Tijuana River Mouth State Marine Conservation Area
(SMCA), which is a type of Marine Protected Area (MPA), located along the coast of Border Field
State Park, in January 2012 (City of Imperial Beach, 2019). MPAs are intended to protect marine
ecosystems and conserve biodiversity (City of Imperial Beach, 2019). The Tijuana River Mouth
SMCA is approximately 3 square miles and comprises 2.37 miles of shoreline (CDFW, 2016). Within
the Tijuana River Mouth SMCA, fishing is limited to Coastal Pelagic Species (CPS) (except market
squid) with additional restrictions (i.e., recreational fishing is limited to hand-held dip nets only and
commercial fishing is limited to round haul nets only).
The coastal communities near the Tijuana River Valley contain numerous recreational
opportunities in the Pacific Ocean. Visitors seek out the marine recreational resources along the
coastlines of San Diego and Imperial Beach, contributing to ecotourism in the area (City of Imperial
Beach, 2019). The City of Imperial Beach is popular for surfing and hosts surfing competitions and
festivals, such as the Dempsey Holder Ocean Festival and Surf Contest, which attracted over 200
contestants in 2019 (WILDCOAST, 2021). Imperial Beach alone has over 400,000 beachgoers
annually, many of whom engage in aquatic recreation activities such as surfing (City of Imperial
Beach, 2019). Despite surfing's popularity, beach closures prevent surfers from enjoying the sport
and negatively impact related businesses, such as local surf shops (Solis, 2018). See Section 3.2.2
(Marine Water Quality) regarding beach closures caused by poor water quality.
Sea kayaking and stand-up paddle boarding are popular along the coast (San Diego Tourism
Authority, 2021). Boating is popular on San Diego Bay, which supports related businesses, such as
fuel docks, boat repair, and waterfront restaurants. Local businesses rent and charter fishing boats
and yachts and rent personal watercraft such as jet skis. Recreational fishers can fish from offshore
boats or ocean piers for species such as bluefin, yellowtail, mahi-mahi, and mako. Companies offer
tours for seasonal blue whale watching, and scuba diving and snorkeling are popular near Point
Loma (San Diego Tourism Authority, 2021).
3.3 Floodplains
Flooding in the Tijuana River Valley regularly results in changes to the floodplain, topographic
features, and the hydrology surrounding the river. The valley floor is relatively flat with low
riverbanks, and therefore a rise in water level of a matter of feet can cause widespread flooding
(SFEI, 2017). Flood events in the valley influence sediment transport and groundwater
replenishment and also contribute to channel avulsions, or rapid lateral movements of the river
channel, within the 100-year floodplain (SFEI, 2017). Large flood events, by clearing and scouring
vegetation, also have impacts on habitat characteristics. For example, the flood events in early 1980
cleared the way for the establishment of current willow forest habitat marking a transition in valley
habitats from riparian scrub to riparian forests (SFEI, 2017).
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Federal Emergency Management Agency (FEMA) Flood Insurance Rate Maps designate a large
portion of the Tijuana River Valley as a Special Flood Hazard Area (SFHA)—also known as the 100-
year floodplain (Zone A and Zone AE)—which indicates areas that would be inundated by the flood
event having a 1 percent chance of being equaled or exceeded in any given year. The majority of the
100-year floodplain is also designated as a regulatory floodway, meaning the river and adjacent
land must be able to discharge the base flood without cumulatively increasing the water surface
elevation more than a designated height (FEMA, 2020b).22 FEMA-designated 500-year floodplains
(Zone X, 0.2 percent Annual Chance Flood Hazard), which have a 0.2 percent chance of being
equaled or exceeded in any given year, are present along the valley perimeter. Areas outside the
500-year floodplain (Zone X, Area of Minimal Flood Hazard) occur on the mesa landforms along the
southern edge of the valley (FEMA, 2020a). The ITP parcel is partially within the mapped 500-year
floodplain with the remaining portion in an area of minimal flood hazard. Smuggler's Gulch and
Goat Canyon are predominantly mapped as an area of minimal flood hazard. See Figure 3-10 for
FEMA flood zone information in the project areas.
The USACE Los Angeles District also studied the Tijuana River floodplain and prepared a sediment
transport model and associated floodplain inundation maps for the Tijuana River in the area of the
Proposed Action (USACE, 2018). The model incorporates flood hydrograph calculations and site
conditions to predict floodplains in the study area using a combination of one-dimensional (ID) and
two-dimensional (2D) unsteady-state hydraulic models. ID modeling applies to upstream regions
with bridges and channelized flow while the 2D model region projects multi-directional flow and
incorporates the hydraulic properties of the terrain using a computational grid (USACE, 2018). The
USACE study presents a 500-year inundation map that shows similar results to the FEMA 500-year
floodplain with the exception of less predicted flooding in areas that would be protected by the
levee system. For example, per this study, the ITP Parcel is not within the 500-year floodplain due
to protection provided by the south levee. See Figure 3-11 for USACE's 500-year inundation map.
Since 1980, large flood events have ranged between 17,500 and 30,000 cfs, none of which exceed
the estimated discharge of 67,100 cfs necessary to be considered a 100-year flood (SFEI, 2017;
USACE, 2018). The only documented flood event that had the capacity to exceed the 100-year
floodplain was the 1916 flood, which produced an estimated 75,000 cfs peak discharge (SFEI,
2017).
Flood control structures in the Tijuana River Valley include the north levee (approximately 2 miles)
that extends to the north of the river and curves around the adjacent sod farm, and the south levee
(approximately 1.9 miles) that parallels the U.S.-Mexico border and then curves along the northern
boundary of the ITP parcel, ending at Dairy Mart Road. The levees, which were constructed in 1978,
are maintained by CBP in accordance with a 1980 Memorandum of Understanding with USIBWC
and are designed to protect adjacent properties from the 100-year flood (USIBWC, 2008). To
protect the ITP, the south levee was enhanced along the border of the ITP parcel to protect the site
from a 333-year flood elevation level and is designed with more than 3 feet of freeboard (IBWC,
2011, p. 7.1-13; Stantec, 2020b). Starting atthe border, the river is contained in an approximately
1,200-foot-long concrete channel leading to a 3,700-foot-long energy dissipater constructed by
USACE in 1978 (USIBWC, 2016). Recent hydraulic models show that the north levee near Dairy
Mart Road would be overtopped during a 100-year flood event and fails to maintain the required
22 The main channel has a Base Flood Elevation (BFE) ranging from 40 feet near Dairy Mart Road Bridge to 56
feet near the border.
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minimum freeboard of 3 feet above the 100-year water surface elevation at three other locations
(Stantec, 2020b). A USIBWC project to enhance the north levee and associated flood control
structures to better withstand the 100-year flood is currently undergoing design (C. Cadillo,
personal communication, April 4, 2022).
Federal, state, and county requirements are placed on actions occurring within floodplains, as
described in Section 6.1.4 (Floodplains).
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3.4 Inland Biological Resources
3.4.1 Botanical Resources
Vegetation Communities Including Sensitive Natural Communities
A wide variety of vegetation communities occur in the Tijuana River Valley and provide habitat to
many special-status species.23 Figure 3-12, Figure 3-13, and Figure 3-14 display the vegetation
communities, including sensitive natural communities,24 that are present in the Tijuana River
Valley near the Proposed Action, based on the Vegetation Classification and Mapping Program
(VegCamp) data from 2016 (CDFW, 2021e); the Vegetation Classification Manual for Western San
Diego County (SANDAG, 2012); and reconnaissance surveys conducted by Stillwater Sciences in
April 2021 (see Appendix D) and February 2022 (a subsequent site visit with USFWS was
conducted, in which these vegetation datasets were further refined to better match available aerial
imagery).25 Table 3-4 summarizes the mapped vegetation types that overlap with the evaluated
areas.26 The developed portion of the ITP parcel contains maintained and landscaped areas, and the
undeveloped portion contains previously disturbed upland habitat that is partially revegetated;
these areas were categorized as disturbed/non-native grassland or Mulefat scrub where
appropriate. CBP conducts mechanical removal of vegetation along the Tijuana River Channel,
though vegetation removal is restricted in areas that provide least Bell's vireo habitat (CBP, 2017).
All other project areas are relatively undeveloped.
Based on the mapping efforts, the most common upland habitat types within the evaluated area are
agriculture, disturbed non-native or planted grasslands, and California sagebrush-California
Buckwheat Alliance. The most common wetland type is Naturalized Warm-Temperate Riparian and
Wetland Semi-Natural Stands, which is dominated by non-native species. Lemonade berry Scrub
and Gooding's willow-red willow Riparian Woodland and Forest are the only sensitive natural
communities documented in the evaluated area (Table 3-4).
23 Special-status plant species are defined as those species listed, proposed, or under review as endangered or
threatened under the federal ESA or the CESA; listed as rare under the California Native Plant Protection Act;
and/or included on CDFW's most recent Special Vascular Plants, Bryophytes, and Lichens List with a California
Rare Plant Rank (CRPR) of 1, 2, 3, or 4 (CDFW, 2020c).
24 Sensitive natural communities are defined as those natural community types with a state ranking of SI
(critically imperiled), S2 (imperiled), or S3 (vulnerable) as listed in the most recent California Natural
Community List (CDFW, 2020a).
25 Stillwater Sciences conducted a reconnaissance survey on April 14-16, 2021, to review the evaluated area.
During this effort, the vegetation mapping was adjusted in some areas; special-status plant and wildlife
species that were incidentally observed were noted (with forms subsequently submitted to CNDDB); and
notes were taken regarding potential habitat for all species (plants, wildlife, and fish).
26 Habitat types excluded from the table include developed, graded/scraped/maintained, and open water.
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Evaluated Area
| j Estimated maximum limit of
disturbance for Core Projects
Other land cover types
Agriculture
Ornamental
Water
Vegetation alliances
Artemisia californica-Eriogonum
fasciculatum Alliance
Atriplex canescens Shrubland Alliance
¦ Baccharis salicifolia
¦ Baccharis sarothroides Association
Glebionis coronaria Semi-IMatural
Stands
Glebionis coronaria Semi-Natural
Stands
Mediterranean California Naturalized
Z/! Annual and Perennial Grassland Semi-
Natural Stands
Naturalized Warm-Temperate Riparian
and Wetland Semi-Natural Stands
¦i Salix gooddingii Alliance
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Figure 3-12. Vegetation Types in the Evaluated Area for the Proposed Action (Upstream of Dairy Mart Road Bridge)
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Evaluated Area
| j Estimated maximum limit of disturbance
for Core Projects
Other land cover types
Agriculture
Ornamental
Water
Vegetation alliances
Artemisia californica-Eriogonum
fasciculatum Alliance
Atriplex canescens Shrubland Alliance
U Baccharis pilularis Alliance
¦ Baccharis salicifolia
¦ Baccharis salicifolia Shrubland Alliance
¦I Baccharis sarothroides Association
x Eucalyptus (globulus, camaldulensis)
Semi-Natural Stands
Glebionis coronaria Semi-Natural Stands
Glebionis coronaria Semi-Natural Stands
Naturalized Warm-Temperate Riparian
and Wetland Semi-Natural Stands
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Figure 3-13. Vegetation Types in the Evaluated Area for the Proposed Action (Detail of ITP Parcel)
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Evaluated Area
| j Estimated maximum limit of
disturbance for Core Projects
Other land cover types
Ornamental
Vegetation alliances
Artemisia californica-Eriogonum
fasciculatum Alliance
/ Baccharis pilularis Alliance
¦ Baccharis salicifolia Shrubland Alliance
Eucalyptus (globulus, camaldulensis)
Semi-Natural Stands
Mediterranean California Naturalized
Annual and Perennial Grassland Semi-
Natural Stands
¦ Rhus integrifolia Alliance
¦ Salix gooddingii Alliance
¦¦Tamarix spp. Semi-Natural Stands
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Figure 3-14, Vegetation Types in the Evaluated Area for the Proposed Action (Smuggler's Gulch and Monument Road)
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Table 3-4. Vegetation Types Mapped Within the Alternative 1 and 2 Areas
Vegetation Typesa'b
Corresponding Holland Type d
Total
Acrese
Alternative Areas
Alternative 1
Alternative 2
Upland types
Agriculture
None
18.79
California sagebrush-California buckwheat Alliance
(Artemisia californica-Eriogonum fasciculatum-Opuntia
littoralis/Dudleya (edulis) Association)c
Maritime Succulent Scrub
7.40
V
V
Coyote brush scrub (Baccharis pilularis Alliance)
Diegan Coastal Sage Scrub:
Baccharis-Dominated
1.42
V
Crown daisy (Glebionis coronaria) Semi-Natural Stands
Disturbed Habitat
5.71
V
V
Disturbed, non-native grassland
None
14.07
V
V
Disturbed, planted grass
None
13.80
V
V
Broom baccharis scrub (Baccharis sarothroides Provisional Alliance
None
1.23
V
V
Eucalyptus (globulus, camaldulensis) Semi-Natural Stands
Eucalyptus Woodland
2.82
V
Fourwing saltbush scrub (Atriplex canescens Shrubland Alliance)
Interior Coast Range Saltbush
Scrub
0.74
V
V
Lemonade berry scrub (Rhus integrifolia Alliance)
Diegan Coastal Sage Scrub
6.48
V
V
Mediterranean California Naturalized Annual and Perennial
Grassland Semi-Natural Stands
Non-Native Grassland
4.81
V
V
Wetland types
Gooding's willow-red willow Riparian Woodland and Forest (Salix
gooddingii-Sa\\x laevigata Forest and Woodland Alliance)
Southern Riparian Woodland
4.44
•/
Mulefat scrub (Baccharis salicifolia Alliance)
Mule Fat Scrub
3.21
V
V
Naturalized Warm-Temperate Riparian and Wetland Semi-Natural
Stands
Non-Native Riparian
148.54
V
Tamarisk thickets (Tamarix spp. Semi-Natural Stands)
Non-Native Riparian
4.58
V
V
a - Based on a combination of VegCamp data (CDFW, 2021e), where available; the Vegetation Classification Manual for Western San Diego County (SANDAG,
2012); and reconnaissance surveys conducted by Stillwater Sciences in April 2021.
b - Bolded alliances are sensitive natural communities with a rank of S3 or higher.
c - The association is listed because it corresponds to a different Holland type (Maritime Succulent Scrub) than the alliance (Diegan Coastal Sage Scrub); the
association correspondence is more accurate in this case,
d-(Holland, 1986).
e - Some portions of the project areas were not mapped.
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Special-status plants
Lists of the special-status plant species and sensitive natural communities potentially occurring in
the Alternative 1 and 2 areas were developed by querying the following resources:
• USFWS Information for Planning and Conservation (IPaC) portal for federally listed and
proposed endangered, threatened, and candidate species (USFWS, 2022).
• CDFW's California Natural Diversity Database (CNDDB) (CDFW, 2022).
• California Native Plant Society's (CNPS's) online Inventory of Rare and Endangered Vascular
Plants of California (CNPS, 2022).
• VegCamp data from 2016 (CDFW, 2021e).
The CNDDB and CNPS queries were based on a search of the U.S. Geological Survey 7.5-minute
quadrangle in which the Project is located (Imperial Beach) and the surrounding four quadrangles27
(Point Loma, National City, Jamul Mountains, and Otay Mesa). Table E-l in Appendix E (Database
Query Results for Special-status Species and Sensitive Natural Communities) provides a summary
of all special-status plant species that may have the potential to be present within the evaluated
area, which includes 16 federally listed and 14 state-listed species. Table 3-5 provides a summary
of special-status plant species with the potential to occur, including those species documented
within the boundaries or in the vicinity (i.e., within 200 feet) of the evaluated area. Of the eight
special-status species documented within or adjacent to the evaluated area, three (San Diego sand
aster, slender cottonheads, and bottle liverwort) are documented within the Core Project Areas.
Appendix E, Table E-2 provides a summary of all sensitive natural communities documented in
CNDDB; Table 3-4 above summarizes vegetation types, including sensitive natural communities
documented in the evaluated area.
27 IPaC, CNDDB, and CNPS databases do not contain data for areas outside California and/or the U.S.
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Table 3-5. Special-status Plant Species with the Potential to Occur Within the Evaluated Area of Each Alternative
Statusa
Scientific Name
Common Name
Federal/State/
CRPR/MSCP
Alternative 1
Alternative 2
Acanthomintha ilicifolia
San Diego thorn-mint
FT/CE/1B.1/MSCP
-
-
Acmispon prostratus
Nuttall's acmispon
-/-/1B.1/-
-
-
Adolphia californica
California adolphia
-/-/2B.1/-
-
-
Agave shawii var. shawii
Shaw's agave
-/-/2B.1/MSCP
-
-
Ambrosia chenopodiifolia
San Diego bur-sage
-/-/2B.1/-
-
-
Ambrosia monogyra
Singlewhorl burrobrush
-/-/2B.2/-
-
A
Ambrosia pumila
San Diego ambrosia
FE/-/1B.1/MSCP
-
-
Aphanisma blitoides
Aphanisma
-/-/1B.2/MSCP
-
-
Artemisia palmeri
San Diego sagewort
-/-/4.2/-
-
-
Atriplex coulteri
Coulter's saltbush
-/-/1B.2/-
-
-
Atriplex pacifica
South Coast saltscale
-/-/1B.2/-
-
-
Bergerocactus emoryi
Golden-spined cereus
-/-/2B.2/-
-
-
Bloomeria clevelandii
San Diego goldenstar
-/-/1B.1/MSCP
-
-
Brodiaea filifolia
Thread-leaved brodiaea
FE/CE/1B.1/MSCP
-
-
Brodiaea orcuttii
Orcutt's brodiaea
-/-/ 1B.1/MSCP
-
-
Calandrinia breweri
Brewer's calandrinia
-/-/4.2/-
-
-
Camissoniopsis lewisii
Lewis' evening-primrose
-
-
Chorizanthe orcuttiana
Orcutt's spineflower
FE/CE/1B.1/MSCP
-
-
Chorizanthe polygonoides var. longispina
Long-spined spineflower
-/-/1B.2/-
-
-
Cistanthe maritima
Seaside cistanthe
-/-/4.2/-
-
-
Convolvulus simulans
Small-flowered morning-glory
-/-/4.2/-
-
-
Corethrogyne filaginifolia var. incana
San Diego sand aster
-/-/1B.1/-
Wb
Wb
Cylindropuntia californica var. californica
Snake cholla
-/-/1B.1/MSCP
-
-
Deinandra conjugens
Otay tarplant
FT/CE/1B.1/MSCP
-
-
Deinandra paniculata
Paniculate tarplant
-/-/4.2/-
-
-
Dichondra occidentalis
Western dichondra
-/-/4.2/-
-
-
Dicranostegia orcuttiana
Orcutt's bird's-beak
-/-/2B.1/MSCP
-
-
Dud ley a attenuata ssp. attenuata
Orcutt's dudleya
-/-/2B.1/-
-
-
Dudleya blochmaniae ssp. blochmaniae
Blochman's dudleya
-/-/1B.1/-
-
-
Dudleya brevifolia
Short-leaved dudleya
-/CE/1B.1/MSCP
-
-
Dudleya variegata
Variegated dudleya
-/-/1B.2/MSCP
-
-
Dudleya viscida
Sticky dudleya
-/-/1B.2/MSCP
-
-
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Table 3-5. Special-status Plant Species with the Potential to Occur Within the Evaluated Area of Each Alternative
Statusa
Scientific Name
Common Name
Federal/State/
CRPR/MSCP
Alternative 1
Alternative 2
Ericameria palmeri var. palmeri
Palmer's goldenbush
-/-/1B.1/-
-
-
Eryngium aristulatum var. parishii
San Diego button-celery
FE/CE/1B.1/MSCP
-
-
Erysimum ammophilum
Sand-loving wallflower
-/-/1B.2/-
-
-
Euphorbia misera
Cliff spurge
-/-/2B.2/-
-
-
Ferocactus viridescens
San Diego barrel cactus
-/-/2B.1/MSCP
A
A
Harpagonella palmeri
Palmer's grapplinghook
-/-/4.2/-
-
-
Hesperevax caulescens
Hogwallow starfish
-/-/4.2/-
-
-
Heterotheca sessiliflora subsp. sessiliflora
Beach goldenaster
-/-/1B.1/-
-
W
Hordeum intercedens
Vernal barley
-/-/3.2/-
-
-
Isocoma menziesii var. decumbens
Decumbent goldenbush
-/-/1B.2/-
-
-
Iva hayesiana
San Diego marsh-elder
-/-/2B.2/-
A
wb
Juglans californica
Southern California black walnut
-/-/4.2/-
-
-
Lasthenia glabrata subsp. coulteri
Coulter's goldfields
-/-/1B.1/-
-
-
Lepidium virginicum var. robinsonii
Robinson's pepper-grass
-/-/4.3/-
-
-
Leptosyne maritima
Sea dahlia
-/-/2B.2/-
-
-
Lilium humboldtii subsp. ocellatum
Ocellated Humboldt lily
-/-/4.2/-
-
-
Lycium californicum
California box-thorn
-/-/4.2/-
-
-
Microseris douglasii subsp. platycarpha
Small-flowered microseris
-/-/4.2/-
-
-
Monardella stoneana
Jennifer's monardella
-/-/1B.2/-
-
-
Monardella viminea
Willowy monardella
FE/CE/1B.1/MSCP
-
-
Mucronea californica
California spineflower
-/-/4.2/-
-
-
Myosurus minimus subsp. apus
Little mousetail
-/-/3.1/MSCP
-
-
Nama stenocarpa
Mud nama
-/-/2B.2/-
-
-
Navarretia fossalis
Spreading navarretia
FT/-/1B.1/MSCP
-
-
Navarretia prostrata
Prostrate vernal pool navarretia
-/-/1B.1/-
-
-
Nemacaulis denudata var. gracilis
Slender cottonheads
-/-/2B.2/-
Wb
wb
Orcuttia californica
California Orcutt grass
FE/CE/1B.1/MSCP
-
-
Orobanche parishii subsp. brachyloba
Short-lobed broomrape
-/-/4.2/-
-
-
Phacelia stellaris
Brand's star phacelia
-/-/1B.1/-
-
-
Quercus dumosa
Nuttall's scrub oak
-/-/1B.1/-
-
-
Romneya coulteri
Coulter's matilija poppy
-/-/4.2/-
-
-
Selaginella cinerascens
Ashy spike-moss
-/-/4.1/-
-
-
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Table 3-5. Special-status Plant Species with the Potential to Occur Within the Evaluated Area of Each Alternative
Statusa
Scientific Name
Common Name
Federal/State/
CRPR/MSCP
Alternative 1
Alternative 2
Senecio aphanactis
Chaparral ragwort
-/-/2B.2/-
-
-
Sphaerocarpos drewiae
Bottle liverwort
-/-/1B.1/-
W
W
Stipa diegoensis
San Diego County needle grass
-/-/4.2/-
-
-
Stylocline citroleum
Oil neststraw
-/-/1B.1/-
-
-
Viguiera laciniata
San Diego County viguiera
-/-/4.3/-
Ac
Ac
Non-vascular plants
Geothallus tuberosus
Campbell's liverwort
-/-/1B.1/-
-
-
Mobergia calculiformis
Light gray lichen
-
-
Tortula californica
California screw-moss
-/-/1B.2/-
-
-
Source: (CDFW, 2022; CNPS, 2022; USFWS, 2022).
Note: W = Special-status plant species documented within the boundaries of each Alternative Area; A = Special-status plant species documented adjacent to
each Alternative Area.
a - Federal: FE = Federally endangered, FT = Federally threatened, - = No federal listing; State: CE = California endangered, - = No California listing; California
Rare Plant Rank (CRPR) List Ranks: List IB = Plants rare, threatened, or endangered in California and elsewhere; List 2B = Plants rare, threatened, or
endangered in California, but more common elsewhere; List 4 = Plants of limited distribution, a watch list; CRPR Threat Ranks: 0.1 = Seriously threatened in
California (high degree/immediacy of threat); 0.2 = Fairly threatened in California (moderate degree/immediacy of threat); 0.3 = Not very threatened in
California (low degree/immediacy of threats or no current threats known); MSCP: Species covered under the Multiple Species Conservation Program (MSCP).
b - These occurrences as represented by large polygons as exact location are inaccurate; therefore, it is unclear if the species is within or adjacent to the
evaluated areas.
c-Species documented during reconnaissance surveys in April 2021.
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Habitat Conservation Plans
Biological resources management in the Tijuana River Valley is handled by various entities with
applicable jurisdiction such as the City of San Diego and the USFWS. The MSCP is a cooperative
regional conservation planning program whose goal is to balance protection of habitat and species
with recreation, development, and agricultural activities within the San Diego region (County of San
Diego, 2020a). The MSCP provides a means to comply with federal and state conservation laws; it
establishes conservation guidelines and terms under which non-federal development may 'take'28
covered species incidental to an otherwise lawful activity, including how the take will be minimized
and mitigated to the maximum extent practicable (City of San Diego, 2021d). The Tijuana River
Valley is located within the City of San Diego MSCP Subarea Plan boundaries, which also includes a
Multi-Habitat Planning Area (MHPA) delineated by the City of San Diego to protect critical, sensitive
biological resources (County of San Diego, 2007). A large portion of the Tijuana River Valley is
included in this MHPA. Development may be subject to the guidelines established in the Subarea
Plan for the MSCP. Plant species covered under this plan are described below, and wildlife species
covered under this plan are described in Section 3.4.2 (Wildlife and Inland Fish Resources) below.
The MSCP covers 46 plant species and recognizes multiple other species (e.g., narrow endemic
species). In addition to special-status plant species discussed above that may be covered under the
MSCP, the following MSCP species do not meet the definition of special-status plant species above
but are likely to use or are known to occur in the Tijuana River Basin or surrounding area: coast
wallflower (Erysimum ammophium), Dean's milk vetch [Astragalus deanei), Del Mar Mesa sand
aster (Corethrogyne filaginifolia var. linifolia), heart-leaved pitcher sage (Lepechinia cardiophylla),
mission Canyon bluecup (Githopsis diffusa subsp. filicaulis), narrow-leaved nightshade (Solarium
tenuilobatum), Nuttall's lotus (lotus nuttallianus), Palmer's ericameria (Ericameria palmeri subsp.
palmeri], slender-pod jewelflower (Caulanthus heterophyllus), and dense pine-reed grass
(Calamagrostis koelerioides).
3.4.2 Wildlife and Inland Fish Resources
General
The Tijuana River Valley is home to many wildlife and fish species. Habitats within the Tijuana
River Valley provide foraging and nesting habitat for migratory and resident bird species, as well as
cover and foraging opportunities for reptiles and mammals (County of San Diego, 2007). Fish have
been observed in the small tidal creeks and channels found in the Tijuana River Valley, and
anadromous fish species have historically used the Tijuana River as a migratory corridor to reach
spawning and rearing habitat located in upstream perennial waters. The Tijuana River Estuary is
designated an NNL due to its national significance, possessing one of the finest saltwater marshes
on the California coastline, supporting endangered bird species, and providing important habitat
for other wildlife, especially waterfowl (National Park Service, 2020).
Special-status wildlife and fish species are defined as: 1) listed, proposed for listing, or under
review as rare, threatened, or endangered under the federal ESA or the CESA; 2) protected under
the BGEPA; or 3) designated by CDFW as Fully Protected or a Species of Special Concern. See
28 In accordance with the ESA, the term "take" means to harass, harm, pursue, hunt, shoot, wound, kill, trap,
capture, or collect, or to attempt to engage in any such conduct.
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Section 6.1.5 (Inland Biological Resources) for information on federal and state laws that protect
species found in the Tijuana River Valley.
As discussed in Section 3.4.1 (Botanical Resources), development within the Tijuana River Valley
may be subject to the guidelines established in the MSCP per the City of San Diego MSCP Subarea
Plan. The MSCP, which covers 39 wildlife species, establishes conservation guidelines and terms
under which non-federal development may take covered species incidental to an otherwise lawful
activity, including how the take will be minimized and mitigated to the maximum extent
practicable. The MSCP recognizes wildlife species, including a subset with no federal or state listing
or status (e.g., Species of Special Concern), that could use habitats in the Tijuana River Basin. In
addition to special-status wildlife species discussed in the sections below that may be covered
under the MSCP, the following MSCP-covered species do not meet the definition of special-status
wildlife above but are likely to use or are known to occur in the Tijuana River Basin or surrounding
area: wandering (salt marsh) skipper butterfly (Panoquina errans), orange-throated whiptail
[Aspidoscelis hyperythra),29 Canada goose (Branta canadensis), reddish egret (Egretta rufescens),
white-faced ibis [Plegadis chihi), Cooper's hawk [Accipiter cooperii),30 ferruginous hawk (Buteo
regalis), long-billed curlew [Numenius americanus), elegant tern (Thalasseus elegans), western
bluebird (Sialia mexicana), rufous-crowned sparrow (Aimophila ruficeps), mountain lion (Puma
concolor), and southern mule deer (Odocoileus hemionusfuliginatus).
USFWS practices predator management atthe Tijuana River Slough NWRto increase the
productivity of the California least tern, the light-footed Ridgway's rail, and the western snowy
plover (CDPR, USFWS, & NOAA, 2010). Avian and mammalian predator monitoring is conducted to
identify and control predators that pose a threat to these critical populations (CDPR, USFWS, &
NOAA, 2010). In addition, physical devices such as tiles and exclosures are placed within California
least tern and snowy plover colonies to help protect chicks and eggs from predation, and nesting
platforms are installed in marsh habitats to help with enhanced light-footed Ridgway's rail
protection from avian predators (CDPR, USFWS, & NOAA, 2010).
The Tijuana River Valley faces a number of threats from invasive species. For example, the shot hole
borer beetle damages native plants by causing fungal infections and, following an outbreak in 2015,
has impacted thousands of trees in the valley (SFEI, 2017). Additionally, the presence of brown-
headed cowbirds in the Tijuana River Valley have impacted nesting success of special-status
species, including the least Bell's vireo (Unitt, 2004). Human induced habitat modifications, such as
the abandonment of previous sand and gravel burrow pits in the vicinity of Dairy Mart Road, create
perennial ponds that support a variety of invasive species (R. Fisher, personal communication, April
2, 2021).
Wildlife
A list of the special-status wildlife species potentially occurring in or near the Alternative 1 and 2
areas was developed by querying the IPaC portal for federally listed and proposed endangered,
threatened, and candidate species (USFWS, 2022); the CNDDB (CDFW, 2022); and available
biological reports and literature from the region.
29 Observed in the Tijuana River Estuary during the April 2021 reconnaissance surveys by Stillwater Sciences.
30 Call heard near gravel borrow pits during the April 2021 reconnaissance surveys by Stillwater Sciences.
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To determine the likelihood of each special-status wildlife species (from the database queries) to
occur in or near the evaluated areas, the habitat preferences and distributional range of each
species was compared with existing information, results of prior surveys, and information collected
from reconnaissance-level habitat assessments conducted by Stillwater Sciences in April 2021 and
February 2022. The field assessments focused on areas along the Tijuana River Basin, including
Tijuana River (from the international boundary to Dairy Mart Road), the ITP and surrounding
infrastructure and staging areas, and Smuggler's Gulch. The field visits included examining the
extent and quality of available habitat features and elements (e.g., habitat connectivity and suitable
aquatic habitat) and noting all wildlife species observed, including special-status species.
The following describe the categories for likelihood of a special-status species to occur in or near
the evaluated area:
• None (no potential to occur): the alternative area is outside of the species' known
distribution or elevation range and/or the species' required habitat is lacking from the
alternative area.
• Low (not expected to occur): the species' known distribution or elevation range overlaps
with the alternative area and the species' required habitat is of very low quality or quantity
in the alternative area; suitable key habitat or habitat elements may be present but may be
of poor quality or isolated from the nearest extant occurrences.
• Moderate (may possibly occur): the species' known distribution or elevation range overlaps
with the alternative area and the species' required habitat occurs in the alternative area.
There may be documented extant occurrences nearby.
• High (present): the species has been documented in the alternative area and/or its required
habitat occurs in the alternative area and is of high quality.
Fifty-seven special-status wildlife species were identified from the database queries as potentially
occurring in the evaluated area (Appendix E). Of these, 15 species were determined to have no
potential to occur in the project boundaries or be affected by the alternatives (Appendix E). Table
3-6 lists the 42 species with high, moderate, or low potential to be present in the project boundaries
(of the Core Projects for Alternative 1) or, in the case of Alternative 2, to be present in areas
potentially affected by predicted downstream effects in addition to the project boundaries. Effects
on species with high or moderate potential to occur in the evaluated area are included in Section
4.4 (Inland Biological Resources). Species with low potential to occur are only evaluated for project-
related effects (Section 4.4 [Inland Biological Resources]) if they are federally and/or state-listed
under the ESA and/or CESA and where unavoidable impacts to the species would be potentially
significant. Appendix E (Database Query Results for Special-status Species and Sensitive Natural
Communities) includes additional details for special-status wildlife species, including likelihood to
occur, status, range, and closest documented occurrences (if any).
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Table 3-6. Special-status Wildlife Species with Low, Moderate, or High Potential to Occur
Common Name
Scientific Name
Status
Likelihood to Occur
(Federal/State/
MSCP)a
Habitat Associations
Alternative
1
Alternative
2
Invertebrates
San Diego fairy shrimp
FE/-/MSCP
Coastal vernal pool complexes and similar ephemeral wetland types
Low
Low
Branchinecta sandiegonensis
Riverside fairy shrimp
FE/-/MSCP
Vernal pools, ponds, and other ephemeral pools or pool complexes
None
Lowc
Streptocephalus woottoni
Crotch's bumble bee
-/SCE/-
Open grassland and scrub habitats; nests are often located underground in
Low
Low
Bom bus crotch ii
abandoned rodent burrows, or above ground in tufts of grass, rock piles,
or tree cavities
Monarch Butterfly
FC/-/-
Coastal California groves of blue gum eucalyptus (Eucalyptus globulus),
Low
Low
(Western North American ACU)
Monterey pine (Pinus radiata), and Monterey cypress (Cupressus
Danaus plexippus
macrocarpa); milkweed (Asclepias spp.) is a host plant required for
species' breeding
Hermes copper butterfly
FPT/-/-
Host plants include spiny redberry (Rhamnus crocea) in coastal sage scrub
Low
Low
Lycaena Hermes
and chaparral vegetation; primary nectar source is California buckwheat
(Eriogonum fasciculatum)
Quino checkerspot butterfly
FE/-/-
Grasslands, coastal sage scrub, chamise chaparral, red shank chaparral,
Low/
Low/
Euphydryas editha quino
juniper woodland, and semi-desert scrub; primary host plants are native
species of plantain
Moderate
Moderate
Amphibians
Western spadefoot
Status Review
Areas with sparse vegetation and/or short grasses in sandy or gravelly
None
Low0
Spea hammondii
7
ssc/-
soils; washes, river floodplains, alluvial fans, playas, alkali flats; breeds in
ephemeral rain pools with no predators
Arroyo toad
FE/SSC/
Washes, arroyos, sandy riverbanks, riparian areas with willows,
None
Lowc
Bufo californicus
MSCP
sycamores, oaks, cottonwoods; needs exposed sandy streamsides with
stable terraces for burrowing, with scattered vegetation for shelter, and
areas of quiet water or pools free of predatory fishes with sandy or gravel
bottoms without silt for breeding
Reptiles
Western pond turtle
-/SCC/MSCP
Permanent, slow-moving fresh or brackish water with available basking
Low
Lowc
Actinemys marmorata
sites and adjacent open habitats or forest for nesting
Coast horned lizard
-/SCC/MSCP
Open areas with sandy soil and/or patches of loose soil and low/scattered
Moderate
Moderate
Phrynosoma blainvillii
vegetation in scrublands, grasslands, conifer forests, and woodlands;
frequently found near ant hills
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Table 3-6. Special-status Wildlife Species with Low, Moderate, or High Potential to Occur
Common Name
Scientific Name
Status
(Federal/State/
MSCP)a
Habitat Associations
Likelihood to Occur
Alternative
1
Alternative
2
Southern California legless
lizard
Anniella stebbinsi
-/ssc/-
Sparsely vegetated beaches, chaparral, pine-oak woodland, and
streamside growth of sycamores, cottonwoods, and oaks; occasionally
enters desert scrub; requires loose soil habitats for burrowing
Moderate
Moderate
California glossy snake
Arizona elegans occidentalis
-/ssc/-
Most common in desert habitats, prefers scrub and grassland with loose
or sandy soils
Low
Low
Baja California coachwhip
Masticophis fuliginosus
-/ssc/-
Occupies a variety of habitats including desert, prairie, scrubland, juniper-
grassland, woodland, thornforest, and farmland; usually avoids dense
vegetation
Moderate
Moderate
Two-striped garter snake
Thamnophis hammondii
-/ssc/-
In or near permanent fresh water, often along streams with rocky beds
and riparian vegetation
Low
Low
Birds
California brown pelican
Pelecanus occidentalis
FD/SD, SFP/
MSCP
Nests on low rocky or brushy slopes of undisturbed islands; rarely seen
inland or far out at sea; roost habitat includes islands, offshore rocks,
beaches, mudflats, wharfs, piers, breakwaters, and jetties
High d
High d
Bald eagle
Haliaeetus leucocephalus
FD, BGEPA/SE,
SFP/MSCP
Large bodies of water or rivers with abundant fish, uses snags or other
perches; nests in advanced-successional conifer forest near open water
Lowd
Lowd
Northern harrier
Circus cyaneus
-/SSC/MSCP
Nests, forages, and roosts in wetlands or along rivers or lakes, but also in
grasslands, meadows, or grain fields
High
High
White-tailed kite
Elanus leucurus
—/SFP/—
Lowland grasslands and wetlands with open areas; nests in trees near
open foraging areas
High
High
Swainson's hawk
Buteo swainsoni
-/ST/MSCP
Nests in oaks or cottonwoods in or near riparian habitats; forages in
grasslands, irrigated pastures, and grain fields
Lowd
Low/
Moderated
Golden eagle
Aquila chrysaetos
BGEPA/-/MSCP
Open woodlands and oak savannahs, grasslands, chaparral, sagebrush
flats; nests on steep cliffs or medium to tall trees
Lowd
Lowd
American peregrine falcon
Falco peregrin us anatum
FD/SD,
SFP/MSCP
Wetlands, woodlands, cities, agricultural lands, and coastal area with cliffs
(and rarely broken-top, predominant trees) for nesting; often forages near
water
Moderated
Moderated
California black rail
Laterallus jamaicenis
coturniculus
-/ST, SFP/-
Large tidally influenced marshes with saline to brackish water, typically
with a high proportion of pickleweed (Salicornia virginica); also can be
associated with bulrush (Schoenoplectus spp.), cattail (Typha spp.), or
rushes (Juncus spp.)
None
Lowc
Light-footed Ridgway's rail
Rallus obsoletus levipes
FE/SE, SFP/-
Coastal salt marshes with tall dense California cordgrass, wrack deposits,
and available high marsh zones to provide refugia during high tides
None
Moderatec
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Table 3-6. Special-status Wildlife Species with Low, Moderate, or High Potential to Occur
Common Name
Scientific Name
Status
Likelihood to Occur
(Federal/State/
MSCP)a
Habitat Associations
Alternative
1
Alternative
2
Western snowy plover
FT/SSC/MSCP
Barren to sparsely vegetated beaches, barrier beaches, salt-evaporation
None
Lowc
Charadrius nivosus
pond levees, and shores of alkali lakes; also nests on gravel bars in rivers
with wide flood plains; needs sandy, gravelly, or friable soils for nesting
Mountain plover
-/SSC/MSCP
Occupies open plains or rolling hills with short grasses or very sparse
Low
Moderated
Charadrius montanus
vegetation; nearby bodies of water are not needed; may use newly
plowed or sprouting grain fields
California least tern
fe/se,
Sparsely vegetated coastal beaches and estuaries near shallow waters,
Lowd
Lowc
Sternula antillarum browni
SFP/MSCP
above high tide line
Western burrowing owl
-/SSC/MSCP
Level, open, dry, heavily grazed, or low- stature grassland or desert
Low
Low
Athene cunicularia hypugaea
vegetation with available burrows
Southwestern willow flycatcher
FE/SE/MSCP
Riparian habitat, commonly wider than 10 meters; nesting occurs in native
Moderated
Highd
Empidonax traillii extimus
willow (Salix spp), non-native tamarisk (Tamarix spp.), and other riparian
vegetation stands 4-7 meters high
Least Bell's vireo
FE/SE/MSCP
Nests in dense vegetative cover of riparian areas; often nests in willow or
High
High
Vireo bellii pusillus
mulefat; forages in dense, stratified canopy
Coastal California gnatcatcher
FT/SSC/-
Low, coastal sage scrub in arid washes, on mesas, and on slopes
High
High
Polioptila californica
Yellow warbler
-/SSC/-
Open canopy, deciduous riparian woodland close to water, along streams
High
High
Setophaga petechia
or wet meadows
Yellow-breasted chat
-/SSC/-
Early successional riparian habitats with a dense shrub layer and an open
High
High
Icteria virens
canopy
Belding's savannah sparrow
-/SE/MSCP
Inhabits coastal salt marshes; nests in pickleweed (Salicornia) on and
Lowd
Moderatec
Passerculus sandwichensis
about margins of tidal flats
beldingi
Large-billed savannah sparrow
-/SSC/MSCP
Inhabits coastal salt marshes; breeds in salt marshes and alkaline sumps
Lowd
Lowc-d
Passerculus sandwichensis
rostratus
Tricolored blackbird
-/ST, SSC/MSCP
Feeds in grasslands and agriculture fields; nesting habitat components
None
Moderatec
Agelaius tricolor
include open accessible water, a protected nesting substrate (including
flooded or thorny vegetation), and a suitable nearby foraging space with
adequate insect prey
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Table 3-6. Special-status Wildlife Species with Low, Moderate, or High Potential to Occur
Common Name
Scientific Name
Status
Likelihood to Occur
(Federal/State/
MSCP)a
Habitat Associations
Alternative
1
Alternative
2
Mammals
San Diego desert woodrat
-/ssc/-
Rocky areas within several habitats, including Joshua tree, pinyon-juniper,
None
Low
Neotoma lepida intermedia
chaparral, sagebrush, and desert habitats
Northwestern San Diego
-/ssc/-
Occurs mainly in arid coastal and desert borders; sandy herbaceous areas
Moderate
Moderate
pocket mouse
with rocks or coarse gravel within chaparral, coastal scrub, and grassland
Chaetodipus fallax
communities
San Diego black-tailed
-/ssc/-
Open or sparse grasslands, coastal scrub, and agricultural fields; not
Moderate
Moderate
jackrabbit
typically found in high grass or dense brush
Lepus californicus ssp. bennettii
Mexican long-tongued bat
-/ssc/-
Desert, montane, riparian, and pinyon-juniper habitats; roosts in desert
Low
Low
Choeronycteris mexicana
canyons, deep caves, mines, rock crevices, or abandoned buildings (in
urban environments)
Western red bat
-/ssc/-
Riparian forests and woodlands near streams, fields, and orchards
None
Lowd
Lasiurus blossevillii
Pallid bat
-/ssc/-
Roosts in rock crevices, tree hollows, mines, caves, and a variety of vacant
Low
Low
Antrozous pallidus
and occupied buildings; feeds in a variety of open woodland habitats
American badger
-/SSC/MSCP
Shrubland, open grasslands, fields, and alpine meadows with friable soils
Low
Low/
Taxidea taxus
Moderate
a - Federal: FE = Listed as endangered under the federal ESA; FT = Listed as threatened under the federal ESA; FC = Federal candidate species; FPT = Federally
proposed as threatened; FD = Federally delisted; BGEPA = Protected under the Bald and Golden Eagle Protection Act; State: SE = Listed as endangered under
the CESA; ST = Listed as threatened under the CESA; SD = State delisted; SSC = CDFW Species of Special Concern; SFP = CDFW Fully Protected species; MSCP =
Species covered under the Multiple Species Conservation Program.
b - In July 2015, after a 90-day review in response to a petition to list the western spadefoot toad, USFWS determined that there was sufficient evidence to
support the potential listing of the species (USFWS-R8-ES-2015-0066). In January 2020, the USFWS initiated a status review (12-month finding), requesting
information to support a Species Status Assessment and inform a possible future critical habitat designation.
c - While there is no or low potential to occur in the evaluated area for the Alternative, the species is known to or may occur in areas downstream of the
evaluated area (e.g., in Tijuana River downstream of Dairy Mart Road and/or in Tijuana Estuary) and may be affected by flow effects from the Alternative,
d - Potential for foraging, loafing, fly-over, or stopover during migration; no potential for nesting because the Alternative is outside of species' nesting range,
or there is a lack of suitable nesting habitat.
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Several federally listed wildlife species are known to occur in the greater Tijuana River Valley,
including San Diego fairy shrimp (Branchinecta sandiegonensis), Quino checkerspot butterfly
(Ephydryas editha quino), light-footed Ridgway's rail (Rallus obsoletus levipes),31 western snowy
plover (Charadrius alexandrinus nivosus), California least tern (Sternula antillarum browni),
southwestern willow flycatcher (Empidonax traillii extimus),32 least Bell's vireo (Vireo belli pusillus),
and coastal California gnatcatcher (Polioptila californica californica). As shown in Figure 3-15,
USFWS has defined three federally designated critical habitat areas in the valley (San Diego fairy
shrimp, least Bell's vireo, and western snowy plover). Of these, critical habitat for least Bell's vireo
overlaps with the evaluated area.
In addition to those mentioned above that also have a federal listing, state-listed species that may
be present in the alternative areas include Belding's savannah sparrow (Passerculus sandwichensis
beldingi), tricolored blackbird (Agelaius tricolor), and Swainson's hawks (Buteo swainsoni).
Swainson's hawks and mountain plovers (Charadrius montanus) have been documented in the
region, though only as migrants (i.e., not breeding). Numerous state Species of Special Concern
and/or Fully Protected species may also occur in the project areas, including birds (e.g., yellow
warbler [Setophaga petechia], yellow-breasted chat [Icteria virens], white-tailed kite [Elanus
leucurus], northern harrier [Circus hudsonius]), and mammals (e.g., San Diego black-tailed jackrabbit
[Lepus californicus bennettii], American badger [Taxidea taxus], and various special-status bats)
(Table 3-6).
ITP Parcel
The ITP parcel consists of all disturbed and developed land, with few wildlife species observed
onsite. Federally listed wildlife species known to occur in the general vicinity include least Bell's
vireo and coastal California gnatcatcher (Parsons, 2005). Least Bell's vireo is a federally and state-
listed endangered species that nests in dense riparian vegetative cover, often in willow or mulefat,
and forages in dense, stratified, overstory canopy. The coastal California gnatcatcher is federally
listed as threatened and is a CDFW Species of Special Concern that is known to live in coastal scrub
habitat with low-growing deciduous vegetation and with documented occurrences in the vicinity
from 2016 (CDFW, 2020a).
Special-status white-tailed kite (Fully Protected) was observed in this area in 2004 (Parsons, 2005)
and during the April 2021 reconnaissance surveys by Stillwater Sciences. Northern harrier (Circus
hudsonius) (Species of Special Concern) are expected to forage in the disturbed areas.
31 Formerly light-footed clapper rail (Rallus longirostris levipes) (CDFW, 2021c).
32 As migrants only.
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TIJUANA RIVER
ESTUARY
PACIFIC
OCEAN
r
I I Evaluated Area
Federal critical habitat
Western snowy plover (Charadrius nivosus nivosus)
San Diego fairy shrimp (Branchinecta sandiegonesis)
Least Bell's vireo (Vireo bellii pusillus)
RCITiYlbF.
IMPERIAL BEACH
NAVAL OUTLYING
LANDING FIELD
IMPERIAL BEACH
iSANnYSIDRO'
'.C amino d e
*. MEXICO
DOWNTOWN^
SAN
DIEGO
IMPERIAL
BEACH -
CHULA
VISTA
Tijuana
River -
Valley
Figure 3-15. USFWS Critical Habitat in the Tijuana River Valley
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Fish
Special-status fish species that could occur near or within project areas include:
• Steelhead [Oncorhynchus mykiss; federally endangered).
• Pacific lamprey (Entosphenus tridentatus; California State Species of Special Concern).
Below are descriptions of special-status fish species distribution and status, life histories and
habitat requirements, and potential for occurrence within the Tijuana River. Descriptions of species
composition in the Tijuana River Estuary are also provided.
Steelhead
Steelhead in the Tijuana River are considered a part of the Southern California steelhead Distinct
Population Segment (DPS), which is listed as endangered by the federal ESA (NMFS, 2012). The
Southern California DPS includes the areas of the coastal watersheds that are seasonally accessible
to steelhead migrating upstream from the ocean (NMFS, 2012). Steelhead above impassable
barriers are not listed under or afforded the protection of the federal ESA (NMFS, 2012). Of note,
the Tijuana River is one of the southernmost watersheds that historically supported the federally
endangered Southern California steelhead DPS (NMFS, 2012).
Southern California steelhead is a species of trout that can migrate to the ocean (referred to as
anadromous) or complete its life cycle entirely in fresh water (referred to as resident). Steelhead is
the term used to describe the anadromous life history type, whereas freshwater residents are
generally referred to as rainbow trout The two life history forms are capable of interbreeding, and
one life history form can produce offspring that follows the alternate form. The decision for an
individual to adopt a life history pathway, such as anadromy or residency, is influenced by a
combination of genetics, fish condition, and environmental factors (Kendall etal., 2014).
Due to limited data specific to the Tijuana River, the presence of life history strategies and timing
for steelhead life stages in the Tijuana River watershed are assumed to be similar to other
populations within the Southern California steelhead DPS.
Southern California steelhead are considered a "winter-run" type, meaning they enter rivers from
the ocean in the winter and spawn shortly thereafter. Winter-run adult steelhead along the
California coast can enter rivers as early as October and as late as June, but most adult steelhead
enter rivers between January and April with peak migration in February and March (Shapovalov &
Taft, 1954). River entry and upstream migration of steelhead in southern California watersheds is
dependent on high flow events that breach sandbars in the lagoon to provide upstream passage.
These high flow events occur during the winter and spring months.
Spawning would occur in tributaries with suitable habitat and could occur anytime during the
migration season and extending into May. In the Tijuana River, suitable habitat for steelhead
spawning is limited to tributaries that exist above barriers and there is no suitable spawning
habitat in the lower Tijuana River. Unlike anadromous Pacific salmon species (Oncorhynchus spp.),
steelhead are iteroparous (i.e., they are capable of repeat spawning), and after spawning, adult
steelhead can remain in fresh water or return to the ocean as "kelts."
A freshwater resident steelhead may utilize tributaries or the mainstem within the watershed or
may migrate between multiple tributaries and mainstem reaches to spawn as a "fluvial" life history
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variant. A steelhead unable or unwilling to access the ocean (e.g., because a barrier is present
within the watershed) may migrate to a lake or reservoir to rear as an "adfluvial" variant.
Steelhead can spend one to seven years in fresh water before outmigrating to the sea and one to
five years in the ocean before returning to the fresh water to spawn (Busby et al., 1996; Kendall et
al., 2014). It is expected that juveniles would emigrate from the Tijuana River to the ocean at age
one or two, and smolts are expected to migrate between March and May, with a few individuals
observed as early as January and as late as July (Booth, 2020).
Smolts may also exhibit a "lagoon rearing" strategy where they rear in the brackish water of a
lagoon prior to entering the marine environment or migrating back upstream (Hayes et al., 2011;
Kendall et al., 2014). These smolts may remain in a lagoon or estuary for a short period of time or a
whole season (Hayes et al., 2011; Shapovalov & Taft, 1954). There is no evidence of a lagoon rearing
life history type in the Tijuana River despite historical monitoring in the lagoon. However, a lagoon
rearing life history type could occur in the Tijuana River provided suitable conditions (e.g.,
downstream passage, suitable water quality) and the occurrence of emigrants from upstream
populations.
Steelhead would have historically migrated in the main channel of the Tijuana River to move
between perennial tributaries and the ocean. There is little historical or current information on
steelhead in the Tijuana River watershed; surveys indicate the potential presence of resident
steelhead populations in upstream perennial tributaries (NMFS, 2012), but barriers prevent these
fish from migrating between ocean and freshwater. Despite the lack of information, specific
recovery actions for steelhead are outlined within the National Marine Fisheries Service (NMFS)
Southern California Steelhead Recovery Plan (2012), including those addressing urban effluent.
Downstream (north) of the U.S.-Mexico border, there is a lack of perennial habitat for steelhead
except in the tidally influenced reaches of the Tijuana River (SFEI, 2017). Therefore, any locations
upstream of the tidally influenced zones could only be seasonally occupied by steelhead or utilized
for migration during high flow events that are typically short-lived. Some pools in the Tijuana River
upstream of the tidally influenced reaches may hold perennial waters, but poor water quality in
these pools would be expected to exclude steelhead. Off-channel, man-made ponds also occur, but
would only be expected to support non-native fish species, not steelhead. Tributaries such as
Smuggler's Gulch are likely unoccupied by fish regardless of flow because of their ephemeral
nature. However, during a biological survey by Stillwater Sciences on April 14, 2021, water and the
presence of tadpoles was noted in Smuggler's Gulch in a pool downstream from Monument Road.
This reach is presumed to be seasonally intermittent and would not support fish unless perennial
flows were provided. Within the lower Tijuana River, it is expected that poor water quality (e.g., low
dissolved oxygen, pollution), high temperatures, and altered flows are limiting to steelhead.
Pacific Lamprey
Pacific lamprey is an anadromous fish species that can be present in the majority of coastal
drainages along the Pacific coast of North America, from Alaska to Mexico (Goodman et al., 2006).
According to Docker (2010), Pacific lamprey across the west coast of North America do not show
major genetic differences between populations. This suggests a lack of natal homing in the species,
meaning Pacific lamprey do not necessarily spawn in the stream where they were born (Docker,
2010). Pacific lamprey are classified as a CDFW Species of Special Concern.
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There is limited information on Pacific lamprey within the Tijuana River watershed. Therefore, it is
assumed that Pacific lamprey life history and habitat requirements in the Tijuana River would be
similar to other rivers at the southern extent of their range.
Within southern California, Pacific lamprey adults typically enter fresh water to migrate upstream
between December and May, with the peak migration occurring in March of most years, depending
on water temperatures and local conditions such as seasonal flow regimes (Booth, 2016; Chase,
2001). Adult Pacific lamprey in the Santa Clara River watershed in southern California typically
spend one year in fresh water prior to spawning (Booth, 2016; Chase, 2001), and it is likely the
same would occur in the Tijuana River watershed. Spawning generally takes place between January
and June, and downstream migrating adults (post-spawn) could occur as late as May. Redds are
typically constructed by both males and females in gravel and cobble substrates within pools, run
tailouts, and low gradient riffles (Brumo etal., 2009; Gunckel etal., 2009; Stone, 2006). During
spawning, eggs are deposited into the redd and hatch after approximately 15 days, depending on
water temperatures (Brumo, 2006; Meeuwig et al., 2005). Pacific lampreys typically die within a
few days to two weeks after spawning (Brumo, 2006; Kan, 1975; Pletcher, 1963). The egg-sac larval
stage, known as prolarvae, spend another 15 days in the redd gravels, during which time they
absorb the remaining egg sac, until they emerge at night and drift downstream (Brumo, 2006).
After drifting downstream, the eyeless larvae, known as ammocoetes, settle out of the water
column and burrow into fine silt and sand substrates that often contain organic matter. Within the
stream network they are generally found in low-velocity, depositional areas such as pools, alcoves,
and side channels (Torgersen & Close, 2004). Depending on factors influencing growth rates, they
rear in these habitats from four to 10 years, filter-feeding on algae and detrital matter before
metamorphosing into the adult form (Moore & Mallatt, 1980; Pletcher, 1963; van de Wetering,
1998). After metamorphosis, smolt-like individuals known as macropthalmia migrate to the ocean,
typically in conjunction with high flow events between winter and spring, where they feed
parasitically on a variety of marine fishes (Beamish & Levings, 1991; Richards & Beamish, 1981).
Pacific lampreys are thought to remain in the ocean for approximately 18 to 40 months before
returning to fresh water as sexually immature adults, typically from late winter to early summer
(Beamish, 1980; Kan, 1975).
Similar to steelhead, Pacific lamprey would have also historically migrated in the main channel of
the Tijuana River to access perennial spawning habitat. There is little information available on
Pacific lamprey in the Tijuana River. However, based on additional information received during the
natural resources workshop held for the project on March 9, 2021 (see Section 7.1.3 [Natural
Resources Workshop]), suitable habitat exists upstream of the project area that could
accommodate Pacific lamprey spawning and rearing, as long as upstream passage was provided
from the ocean (R. Fisher, personal communication, March 9, 2021) and water quality did not result
in mortality of upstream migrants.
Estuarine Species
The estuary provides biological ecosystem services, primarily habitat for juvenile fish. Predominant
fish species present in the estuary include topsmelt (Atherinops affinis), longjaw mudsucker
[Gillichthys mirabilis), arrow goby (Clevelandia ios), California killifish (Fundulus parvipinnis), and
striped mullet (Mugil cepalus) (USIBWC, 2016; Zedler et al., 1992). The estuary also provides
nursery habitat for species caught for recreational fishing, such as the diamond turbot (Hypsopetta
guttulate), California halibut [Paralichthys californicus), surfperches, anchovies, plueronectids,
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croakers, and sea bass (USIBWC, 2008; Zedler et al., 1992). Based on analysis of a long-term
monitoring datasetfrom the estuary, Desmond et al. (2002) found that water temperature was the
primary driver in patterns of fish observed in the estuary, but discharge was also important There
was also predictable seasonality observed in the estuarine fish assemblage, likely due to
temperature variation. Peak abundance was in summer/fall when discharge was low, and
interannual trends showed that periods of increased sewage input affected fish assemblage with
more rapidly maturing fish (e.g., arrow goby) being more dominant under increased sewage inputs
(Desmond et al., 2002).
Summary of Special-status Fish
Overall, there is limited biological survey information on the presence of fish species upstream of
the tidally influenced reaches and near the project sites, but based on biological surveys conducted
on April 14, 2021, these reaches are not expected to support special-status fish species except
potentially during migration events. During migration events, poor water quality may limit fish
migrations or prevent them altogether. Based on the information available and communications
with regional stakeholders, federally endangered species have a very low potential to occur within
the project sites but could occur throughout the year in downstream areas such as the estuary. The
species occupying these areas could be affected by changes in flow, water quality, and/or sediment
transport resulting from projects.
3.5 Marine Biological Resources
In defining the evaluated area for potential project effects under the Proposed Action, EPA and
USIBWC considered the known extent of the SBOO discharge plume along with the locations of
natural bounding features. The SBOO discharge plume monitoring program (City of San Diego,
2020a) has detected the influence of the discharge at stations located approximately 6.6 miles
upcoast and 4.9 miles downcoast of the SBOO. Point Loma is approximately 10 miles to the north of
the SBOO discharge and the continental shelf extends from the shoreline to the shelf break
approximately 10 miles offshore (west) of the coastline. These two prominent natural features are
convenient for defining the northern and across-shore (western) extents of the evaluated area. The
southern extent is the U.S.-Mexico border. Figure 3-16 depicts the evaluated area33 for potential
project effects on marine biological resources.
33 The evaluated area is called the "Action Area" in Appendix F (NMFS Biological Assessment) and Appendix G
(NMFS Essential Fish Habitat Assessment). In addition, the Action Area described in Appendices F and G also
includes the Tijuana River Estuary.
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Habitats and Associated Species
More detailed descriptions of the general character of the marine environment in the evaluated
area are provided in Appendix F (NMFS Biological Assessment) and Appendix G (NMFS Essential
Fish Habitat Assessment), The evaluated area is located near the southern limit of the geographic
region known as the Southern California Bight (SCB). The SCB extends from Point Conception to the
U.S.-Mexico border. The dramatic shift in coastline south of Point Conception affects ocean currents,
resulting in a biogeographic transition zone in the SCB between cool-temperate water in the north
and warm sub-tropical water in the south. In the ocean adjacent to and including the evaluated
area, warm sub-tropical waters are entrained northward from the equator by the oceanography of
the region throughout m ost of the year. Subsequen tly, the evaluated area experiences warmer
water conditions relative to the remainder of the SCB region. Horn etal. (2006) refer to the warm-
temperate ecology in the SCB, which extends into coastal Baja Mexico, as the San Diegan Province.
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Historical surveys have indicated that at least 80 percent of the surveyed seabed in the evaluated
area consists of soft sediment habitat The remainder of seabed habitat consists of rocky reef
habitat, portions of which support kelp forest habitat Surveys throughout the evaluated area of the
infaunal community, fishes, and macro-invertebrates inhabiting the soft sediment habitat have
shown typical assemblages for healthy southern California sandy seafloor habitats. Benthic
macrofauna has typically consisted of worms, crabs, clams, brittle stars, and other small
invertebrates. These organisms play important ecological roles in coastal marine ecosystems off
southern California, including as primary and secondary consumers that support higher trophic
organisms such as fishes, larger invertebrates, and even marine mammals and other vertebrates
such as birds. Annelid polychaete worms have been the dominant infaunal taxonomic group,
constituting more than 80 percent of the total organisms collected in the region. They have been
followed in abundance by crustaceans, mollusks, and echinoderms. Speckled and longfin sanddab
have dominated the benthic associated fish assemblage that have also included many California
lizardfish, California tonguefish, and white croaker. Common midwater and pelagic schooling fishes
have included northern anchovy and Pacific sardine. Other species captured in trawl nets have
included flatfishes such as California halibut, hornyhead turbot, English sole, fantail sole, and
spotted turbot Seabed-associated round fishes have included many species of rockfishes, pink
seaperch, blacktip poacher, Pacific Argentine, spotted cusk-eel, yellowchin sculpin, longspine
combfish, roughback sculpin, plainfin midshipman, queenfish, and California scorpionfish.
Elasmobranchs have included round stingray, California skate, and shovelnose guitarfish.
The wye diffuser and main barrel of the SBOO are armored by rock and boulder that form an
artificial reef in the otherwise sandy seabed of the evaluated area at the depth of the SBOO. Footage
from a remotely operated vehicle (ROV) survey of this structure indicates a healthy reef community
of invertebrates, understory seaweeds, and associated fishes. Encrusting organisms such as
anemone and gorgonian corals are abundant, particularly on the open diffusers of the southern leg.
Biological communities on the northern leg, which does not currently discharge effluent, are
notably less diverse and abundant than on the southern leg. It is likely that the effluent contributes
nutrients that increase the abundance and diversity of marine communities on the southern
diffuser leg.
Inshore and to the north of the SBOO is a cobble and boulder reef that supports an intermittent kelp
forest referred to in this assessment as Imperial Beach Kelp Forest. This feature is discussed in the
Essential Fish Habitat section below. The coastline of the evaluated area consists predominantly of
sandy beach intertidal habitat The northern extent of the evaluated area includes the Point Loma
headland, an area of extensive rocky intertidal habitat. This includes the Cabrillo State Marine
Reserve (SMR) and is discussed in the Marine Protected Areas (MPAs) section below.
Phytoplankton blooms are a common feature of all ocean systems. HABs occur when populations of
usually monospecific species of toxic phytoplankton rapidly increase in numbers. These toxin-
producing algal blooms cause illness and death of fish, seabirds, mammals, and other marine life.
Several species contribute to the formation of HABs, however the most common phytoplankton in
southern California to form HABs is Pseudo-nitzschia. This taxon produces domoic acid and is
responsible for frequent sea lion deaths, toxic blooms, and associated mammal and bird illnesses in
California. Other species include Alexandrium, Gymnodinium, and Pyrodinium, all of which are
associated with paralytic shellfish poisoning (PSP). These HABs result in concentrations of
toxicants in shellfish and are a serious human health risk. The contaminated shellfish and other
lower invertebrates that consume and concentrate the PSP toxins are generally unaffected.
However, there is some evidence that PSPs, which transfer to higher invertebrates and vertebrates
such as fishes, birds, marine mammals, and other animals, may cause harm to other marine life.
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Protected Species
Marine species in California waters derive conservation protection from several legislative
mechanisms. The following sections provide lists of species managed under the federal ESA of 1973
and the CESA of 1970. No critical habitat occurs in the marine evaluated area. Marine mammals
managed under the federal Marine Mammal Protection Act of 1972 (MMPA) and that may occur in
the evaluated area are also included below. These legislations protect their listed species from
'take' as discussed in further detail in Section 6.1.6 (Marine Biological Resources).34 Both sections
include the current designation for each species' management unit under these key marine
conservation policies and their likelihood of occurrence in the evaluated area.
Listed Species
Table 3-7 identifies species and their management units (where applicable) that are listed under
either ESA or CESA and are assessed as having a medium or high likelihood to occur in the
evaluated area. Likelihood of occurrence is based primarily on known species distribution patterns
published in peer-reviewed and academic literature, grey literature publications based on
authoritative sources such as government agencies, and finalized planning documents. A full
description of this assessment is included in Appendix F (NMFS Biological Assessment).
The species identified in Table 3-7 as having a high likelihood of occurrence in the evaluated area
are four species of whales, the green sea turtle (Chelonia mydas), and the shortfin mako shark
[Isurus oxyrinchus). These animals move over large areas to forage or migrate relative to the size of
the evaluated area. The shortfin mako shark is currently proposed for listing due to a decline in
abundance globally; however, they are relatively common in southern California.
34 Take is defined in the ESA as "harass, harm, pursue, hunt, shoot, wound, kill trap, capture, or collect, or to
attempt to engage in any such conduct;" in the MMPA as "to harass, hunt, capture, or kill, or attempt to harass,
hunt, capture, or kill any marine mammal;" and in CESA as to "hunt, pursue, catch, capture, or kill, or attempt
to hunt, pursue, catch, capture, or kill."
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Table 3-7. Species Listed Under the ESA or CESA with Medium to High Likelihood of Occurrence in the
Evaluated Area
Species and Management Unit (DPS)a
Scientific Name
ESA
CESA
Likelihood of
Occurrenceb
Marine mammalsc
Blue whale
Balaenoptera musculus
FE
NL
High
Humpback whale (Central America DPS)
Megaptera novaeangliae
FE
NL
High
Humpback whale (Mexico DPS)
FT
NL
High
Fin whale
Balaenoptera physalus
FE
NL
High
Gray whale (Western North Pacific DPS)
Eschrichtius robustus
FE
NL
Medium
Guadalupe fur seal
Arctocephalus townsendi
FT
CT
Medium
Sea turtles
Green sea turtle (East Pacific DPS)
Chelonia mydas
FT
NL
High
Leatherback sea turtle
Dermochelys coriacea
FE
NL
Medium
Loggerhead sea turtle
Caretta caretta
FE
NL
Medium
Fishes
Shortfin mako or bonito shark
Isurus oxyrinchus
FPL
NL
High
Abbreviations: NL = not listed; T = threatened; E = endangered; F = federal; C = California; PL = petition to list,
a - DPS: Distinct Population Segment.
b - Likelihood of occurrence based on analysis described in Appendix F (NMFS Biological Assessment),
c - All marine mammal DPS listed under ESA are also 'depleted' stocks under the MMPA.
Marine Mammals
Table 3-8 identifies marine mammals not listed under ESA and CESA that may occur in the
evaluated area and identifies the MMPA stock unit and the stock's status under the MMPA.
Likelihood of occurrence is based on the same assessment provided for species in Table 3-7.
Several marine mammals that have a high likelihood of occurrence are pinnipeds and small
cetaceans that may forage consistently in the evaluated area. These are California sea lion, harbor
seal, bottlenose dolphin, and common dolphin. These animals typically have a localized 'home
range' and are therefore likely to remain in the evaluated area for extended periods of time. Pacific
white-sided dolphins are not particularly noted for having a localized home range. In addition, the
entire evaluated area contains Biologically Important Areas for the gray whale for migration and
feeding, and a smaller area off Point Loma is used for blue whale feeding. Gray whales are
migratory, passing through the area twice per year when moving between northern-latitude, warm-
season feeding grounds and southern-latitude, cool-season nursery grounds.
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Table 3-8. Marine Mammal Species with a Medium or High Likelihood of Occurrence in the
Evaluated Area and are Not Listed Under ESA or CESA
Species and Stock Unit
Scientific Name
MMPA Stock
Statusa
Likelihood of
Occurrence
California sea lion (US stock)
Zalophus californianus
Non-strategic
High
Harbor seal (CA stock)
Phoca vitulina
Non-strategic
High
Gray whale (eastern north Pacific stock)
Eschrichtius robustus
Non-strategic
High
Pacific white-sided dolphin (CA/OR/WA stock)
Lagenorhynchus obliquidens
Non-strategic
High
Bottlenose dolphin (CA/OR/WA offshore stock)
Tursiops truncatus
Non-strategic
High
Bottlenose dolphin (CA coastal stock)
Non-strategic
High
Short-beaked common dolphin (CA/OR/WA
stock)
Del phi n us del phis
Non-strategic
High
Long-beaked common dolphin (CA stock)
Del phi n us capensis (bairdii)
Non-strategic
High
Killer whale (eastern north Pacific offshore)
Orcinus orca
Non-strategic
Medium
Risso's dolphin (CA/OR/WA stock)
Grampus griseus
Non-strategic
Medium
a - Under the MMPA, stocks may be designated as 'strategic' if below the maximal population size or 'depleted' if
below an optimal population size.
Essential Fish Habitat
There are four Fishery Management Plans (FMPs) on the Pacific coast of North America that include
managed species with designated Essential Fish Habitat (EFH) that may occur in the evaluated area.
These FMPs are the CPS FMP, the Pacific Coast Groundfish (PCG) FMP, the Pacific Coast Salmon
(PCS) FMP, and the Highly Migratory Species (HMS) FMP. The following section lists species
managed under these four FMPs, and habitat areas defined as EFH areas designated by the FMPs.
Most of the Pacific coastline of North America, including the evaluated area, is encompassed by PCG,
CPS, and krill EFH. Two species of fishes protected under the HMS FMP, dorado and common
thresher shark, have EFH that partially overlaps the evaluated area. No PCS FMP EFH is designated
in the evaluated area. Within the category of EFH, regional Fishery Management Councils are
entitled to identify Habitat Areas of Particular Concern (HAPCs). These subsets of EFH are either
spatially explicit areas or habitat types that have been identified by regional Fishery Management
Councils as having high priority for conservation, management, or research. Three categories of
HAPC occur in the area: canopy kelp, rocky reefs, and estuary. The rocky reef HAPC consists of an
area of cobble seabed to the northeast of the SBOO that provides hard substrate on which algal and
invertebrate communities can attach and numerous other reef species can associate. This rocky reef
also provides substrate for the attachment and growth of giant kelp [Macrocystis pyrifera). Given
the correct ocean conditions, giant kelp plants can reach the sea surface and form a canopy
structure. Canopy kelp and rocky reef habitat are both forms of HAPC recognized under the PCG
FMP. This area is referred to in this assessment as the Imperial Beach Kelp Forest Data showing the
location of the Imperial Beach rocky reef and kelp forest in relation to the Point Loma kelp forest
and other features in the region are shown in Appendix G (NMFS Essential Fish Habitat
Assessment).
Marine Protected Areas (MPAs)
Of the 124 MPAs managed under the Marine Life Protection Act that occur within California, two
MPAs occur within the evaluated area. The Tijuana River Mouth SMCA encompasses approximately
3 square miles from the mean high tide line to approximately 1.4 miles offshore and extends
approximately 2.3 miles upcoast from the U.S.-Mexico border. The MPA encompasses sandy beach
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and subtidal habitat, approximately 0.59 square miles of rocky reef that includes persistent kelp
forest habitat, tidal flats, coastal marsh, and estuary habitat The Cabrillo SMR is located at the
northern extent of the evaluated area and encompasses waters adjacent to the Cabrillo National
Monument at Point Loma. This MPA is approximately 0.39 square miles in size and encompasses
approximately 0.97 miles of rocky intertidal shoreline, the entire shoreline extent of the MPA. The
MPA extends out to sea through an extensive rocky reef habitat that encompasses at least 75
percent of the total area of the MPA. The MPA includes surfgrass, kelp, rocky reef, and a small
amount of beach habitat
The Cabrillo SMR restricts the take or possession of all living, geological, or cultural marine
resources. The Tijuana River Mouth SMCA restricts most take or possession of marine resources
but allows for certain recreational fishing for most CPS. The Tijuana River Mouth SMCA also allows
for infrastructure-related activities and operations that include beach nourishment activities and
the maintenance of existing artificial structures.
3.6 Geological Resources
3.6.1 Geology, Soils, and Topography
Geology
The Tijuana River flows from its headwaters in Mexico northwest into California, through urban
Tijuana, Mexico, and into the undeveloped river valley within the coastal plain of San Diego. The
Tijuana River Valley is located within the Peninsular Ranges Geomorphic Province, with the north-
to northwest-trending Peninsular Ranges east of the watershed (SFEI, 2017). The coastal area
mostly consists of Cenozoic sedimentary rocks with quaternary alluvium along the valley floors
(SFEI, 2017). Mesas south of the valley along the U.S.-Mexico border consist of late Pliocene and
early Pleistocene sedimentary rocks in the San Diego Formation with early to mid-Pleistocene
sedimentary deposits (SFEI, 2017). The Tijuana River Valley formed over the past 10,000 to 12,000
years, with the river depositing sediments to form the alluvial fan delta in the past 5,000 years
(SFEI, 2017).
Portions of the Tijuana River Valley have been used historically for sand and gravel extraction. The
Nelson Sloan Quarry (also known as the Border Highlands Pit) is located immediately west of the
SBWRP and east of Smuggler's Gulch. See Section 3.9 (Land Use) for further discussion of mineral
resource extraction in the valley.
See Section 3.6.2 (Seismic Hazards) for discussion of landslide risks.
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Soils
The Tijuana River traverses east to west through the valley and estuary, contributing alluvial
material to the river valley. Soils in this region are primarily deposited particles from nearby
bedrock sources, which can be unstable (Parsons, 2005). The Natural Resources Conservation
Service (NRCS), an agency of the U.S. Department of Agriculture (USDA), conducts soil surveys and
produces soil maps for general use in characterizing soils (NRCS, 2020). The NRCS soil survey for
the area characterizes the soil map units in the project area, shown in Figure 3-17, as follows:
• Soils at the ITP parcel include Visalia gravelly sandy loam (VbB), which is well drained with
very low runoff and 2 to 5 percent slopes, and Chino fine sandy loam (ChA), which is
moderately well drained with medium runoff and 0 to 2 percent slopes.
• Soils in the Tijuana River main channel are predominantly Chino silt loam, saline (CkA),
which is moderately well drained with low runoff and 0 to 2 percent slopes. A small portion
of the channel is mapped as ChA.
• Soils in Smuggler's Gulch include Riverwash (Rm), which is excessively drained with
negligible runoff and 0 to 4 percent slopes; Visalia sandy loam (VaA), which is well drained
with very low runoff and 0 to 2 percent slopes; and Terrace escarpments (TeF). Soils in Goat
Canyon are also mapped as Rm.
• Soils along Monument Road include ChA and VaA in addition to the following: Olivenhain
cobbly loam (OhF), which is well drained with very high runoff and 30 to 50 percent slopes;
Olivenhain cobbly loam (OhE), which is well drained with very high runoff and 9 to 30
percent slopes; and Olivenhain cobbly loam (OhC), which is well drained with very high
runoff and 2 to 9 percent slopes.
• The Border Highlands between Smuggler's Gulch and the ITP parcel include OhC, OhE, and
OhF in addition to Huerhuero loam (HrC2), which is moderately well drained with very high
runoff and 5 to 9 percent slopes, and TeF.
Fill, alluvium, alluvial fan deposits, and terrace deposits are found at the ITP parcel. These soils are
fine-to-coarse sands with medium-to-low amounts of silts and clays. Gravels, cobbles, and boulders
are found at irregular depths, creating rocky zones. Construction at the ITP parcel is limited by the
loose alluvial deposit and by the elevated water table due to the proximity of the river (Parsons,
2005).
A geotechnical study was recently conducted in the Tijuana River main channel upstream of Dairy
Mart Road. Soil in the main channel was characterized by approximately 4 feet of fill material that
was moist, loose, poorly graded sand with silt layered over alluvium. Soils in the main channel are
granular, subject to erosion, may be subject to caving or sloughing (Stantec, 2019).
Smuggler's Gulch and Goat Canyon soils are highly susceptible to erosion. Rilling is evident
throughout the Tijuana River watershed, with an increase in sediment deposits and avulsion
channels in the past century (Southwest Wetlands Interpretive Association, 2001).
Some of the soils in the river valley have characteristics that can support agriculture, and some are
considered prime farmland. However, as discussed in Section 3.9 (Land Use), none of the project
sites support agriculture or are considered prime farmland.
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Pilot channel
PACIFIC
OCEAN
m
\ city of .
IMPERIAL BEACH
l_ j Tijuana River Valley
_ Soil map units
^OTAYvM ESA
NAVAL OUTLYING
LANDING FIELD
IMPERIAL BEACH
SANhYSIDRO;
MonumentlRHI
[Caminol5j^
united.
MEXICO
'• - i ¦
DOWNTOWN
^TIJUANA v
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Figure 3-17. Soil Map Units in the Tijuana River Valley
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Topography
The Tijuana River Valley consists of low-lying tidal marsh and wetlands bordered by mesa or
terrace escarpments to the south and developed urbanized land to the north and east Three
tributary canyons—Smuggler's Gulch, Goat Canyon, and Yogurt Canyon—are present along the U.S.-
Mexico border. Smuggler's Gulch and Goat Canyon extend for several miles into Mexico. These
canyons are characterized by steep side slopes that contribute sediment-filled flows through the
canyons and into the estuary. The mesa between Goat Canyon and Smuggler's Gulch is known as
Spooner's Mesa. This and other neighboring mesas are known as the Border Highlands and provide
prominent viewpoints overlooking the Tijuana River Valley, as discussed further in Section 3.8
(Visual Resources). The regional topography influences air quality and climate by driving winds
inland to the mountains during the day and allowing winds to blow down the hills and valleys at
night This pushes pollutants to the north and then to the south to Mexico when wind shifts
direction (City of San Diego, 2020d). See Section 3.11 (Air Quality) for additional information.
The Goat Canyon diversion structure is situated at a height of approximately 90 feet above MSL.
The Smuggler's Gulch channel elevation decreases from approximately 56 feet at the diversion
structure to 42 feet where it flows under Monument Road. ITP elevations range from 50 feet to 60
feet above MSL across the developed site. The Tijuana River main channel elevation decreases from
approximately 50 feet at the U.S.-Mexico border to approximately 32 feet where it flows under the
Dairy Mart Road Bridge (SANDAG, 2020c).
3.6.2 Seismic Hazards
The Tijuana River Valley is not located in any Seismic Hazard Zones established by the state Seismic
Hazard Mapping Act. However, the area is a seismically active region that is near several active
regional faults. These include the La Nacion Fault approximately 5 miles inland from the coastline
and the Newport-Inglewood/Rose Canyon Fault system in the northern portion of San Diego Bay
and approximately two miles offshore, including numerous small- to medium-length faults likely in
the area of the SBOO. In San Diego, the majority of earthquakes originate in the Imperial Valley
which contains the Elsinore, San Jacinto, and San Andreas faults (City of San Diego, 2008d). Other
major fault zones located farther off the coast include the San Clemente, the San Diego Trough, the
Coronado Bank, and the Coronado Shelf, which is located 2.5 miles west of the SBOO.
The City of San Diego classifies the Tijuana River Valley and Estuary as having low to moderate
geotechnical and relative risk (City of San Diego, 2008d; Parsons, 2005). A series of faults consisting
of concealed zones, faults, and one inferred fault is located in the border highlands area just north
of the border. The fault lines occur in north-south alignments across the terrace escarpments near
the location of the ITP and between Goat Canyon and Smuggler's Gulch (SANDAG, 2020a). These
faults are listed as potentially active, presumed inactive, or activity unknown according to the San
Diego Seismic Safety Study (City of San Diego, 2008b).
Landslide risks occur when people or structures are exposed to landslides that may involve loss,
injury, or death. A landslide occurred at Smuggler's Gulch in 1992, resulting in erosion and
deposition (Daniels et al., 2022). A portion of the terrace escarpments in the Tijuana River Valley is
identified as a landslide geohazard; this includes areas on the western side of Goat Canyon and both
sides of Smuggler's Gulch (SANDAG, 2020b).
The Tijuana River, floodplains, and estuary are susceptible to liquefaction, which occurs when
granular soils saturated with water reach a liquid state after being shaken. This can cause the
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ground to undergo lateral spreading, lose strength, and cause slope failures during seismic events.
The river main channel has high potential for liquefaction while the bottom of Smuggler's Gulch and
Goat Canyon have low potential, and the elevated portions of the mesas have no potential for
liquefaction (City of San Diego, 2008b).
Figure 3-18 depicts geohazards in the vicinity of the project areas.
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PACIFIC
OCEAN
u--m.
l_ j Tijuana River Valley
1 Fault
' * »Inferred fault
:ri:n Concealed zone
High liquefaction potential
Low liquefaction potential
kXXl Possible or confirmed landslides
Slide prone formation
CITY OF
imperial'beach •;|
-OTAYil
NAVAL OUTLYING
LANDING FIELD
IMPERIAL BEACH
SANiYSIDRO'
[M on um ent]R(j |
C ami no d e
Ii.4-DOWNTOWN
^:.4t»aJIJu'ana^
HNsS
Hni
SAN
DIEGO
IMPERIAL
BEACH -
CHULA
VISTA
Figure 3-18. Geohazards in the Tijuana River Valley
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3.7 Cultural Resources
3.7.1 Summary of Regional Context
The prehistory of San Diego County has most frequently been divided chronologically into three or
four periods. The Terminal Pleistocene/Early Holocene period (ca. 12,000-6000 B.C.) encompasses
the Clovis pattern dating elsewhere in North America to around 11,500 B.C. and is distinguished by
large, fluted projectile points. The San Dieguito pattern (8500-6000 B.C.) includes large projectile
points, bifaces, crescents, scraper planes, scrapers, hammers, choppers, and ground stone. The
Middle/Late Holocene Period (ca. 6000 B.C.-A.D. 800), also known as the La Jolla pattern, includes
extensive shell middens, portable ground stone metates and manos, crudely flaked cobble tools,
expanding-stemmed projectile points (Pinto and Elko forms), and flexed human burials. The Late
Prehistoric period (ca. A.D. 800-1769) is distinguished by small projectile points, brownware
pottery, and the practice of human cremation. Traits characterizing the Late Prehistoric period
include greater use of inland settlement locations, reliance on acorns, a greater emphasis on
hunting, and interregional exchange.
European exploration of the San Diego area was initiated with the maritime expeditions of Juan
Rodriguez Cabrillo in 1542 and Sebastian Vizcaino in 1602. However, the historic period proper did
not begin until 1769, when expeditions under the leadership of Gaspar de Portola and Junipero
Serra reached the region from Baja California. In that year, a royal presidio and the Mision San
Diego de Alcala were founded, and the incorporation of local Kumeyaay into the mission system
was begun. The indigenous populations of the San Diego region encountered by early Spanish
colonizers were speakers of a Yuman language or languages, variously referred to as Kumeyaay,
Diegueno, Tipai, and Ipai. The Kumeyaay territory extended from south of Agua Hedionda Lagoon,
Escondido, and Lake Henshaw to south of Ensenada in northern Baja California and east near the
lower Colorado River. Above the family, the fundamental Kumeyaay social units were the simul
(patrilineage) and the residential community or band. Leaders performed ceremonial, advisory, and
diplomatic functions rather than judicial, redistributive, or military functions. Structures included
houses with excavated floors, ramadas, sweathouses, ceremonial enclosures, and acorn granaries. A
range of community ceremonies were performed, such as coming of age ceremonies and death and
mourning ceremonies.
After Mexico's independence in 1821, the missions were secularized in 1833. Native Americans
released from the San Diego mission returned to their native villages, moved east to areas lying
beyond Mexican control, or sought work on ranchos or in the town of San Diego. The U.S.'s conquest
and annexation of California in the Mexican-American War between 1846 and 1848 resulted in the
Kumeyaay Indian nation being split between two countries. In the years after the U.S. annexed
California, many Native Americans were displaced, and tens of thousands died from diseases,
including smallpox. In the 1870s, President Ulysses S. Grant signed two EOs leading to the
establishment of Indian reservations in San Diego for the San Pasqual, Pala, Santa Ysabel, Sycuan, La
Jolla, Rincon, Viejas, and Capitan Grande bands of Kumeyaay. The Mesa Grande, Pauma, La Jolla,
Campo, Cuyapaipe, La Posta, Manzanita, Rincon, Pauma, and Yuima reservations are all officially
established under authorizing congressional legislation, the Relief for the Mission Indians Act of
1891 (Carter, 2022).
The region experienced cycles of economic and demographic booms and busts, with notable
periods of growth in the mid-1880s, during World Wars I and II, and on a more sustained basis
throughout the postwar decades. Aspects of development included the creation of transportation
networks based on port facilities, railroads, highways, and airports; more elaborate systems of
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water supply and flood control; grazing livestock and growing a changing array of crops; limited
amounts of manufacturing; and accommodating visitors and retirees. The region also developed
several military facilities including the Border Field Auxiliary Naval Air Station's Aerial Target
Bombing/Gunnery Range within the Border Field State Park, which was in operation between 1912
to 1961. After false starts, San Diego converted itself to a substantial city, and then into a
metropolis, with exceptionally wide civic boundaries encompassing such suburbs as Ocean Beach,
Pacific Beach, Clairemont, and La Jolla. Other cities were incorporated in the coastal region,
including National City (1887), Coronado (1891), Chula Vista (1911), Imperial Beach (1956), Del
Mar (1959), Solana Beach (1986), and Encinitas (1986).
A more detailed summary of the prehistoric and historic cultural setting of the Tijuana River Valley
is presented in the Class III Cultural Resource Inventory conducted for the Proposed Action
(Daniels et al., 2022), included as Appendix C of this PEIS.
3.7.2 Resources in the Tijuana River Valley
Section 106 of the National Historic Preservation Act (NHPA) requires federal agencies to consider
the effects of undertakings (i.e., actions) on any historic property and to consult with various
parties, including the State Historic Preservation Officer (SHPO), on these effects. In California, the
California Office of Historic Preservation (OHP) serves as the SHPO.
A Class III Cultural Resource Inventory was conducted for a 336-acre area encompassing the Area
of Potential Effect (APE) of all project elements in the U.S. The investigation results are detailed in a
technical report (Daniels etal., 2022), included as Appendix C of this PEIS. Table 3-9 lists the
cultural resources identified during the Class III Cultural Resource Inventory that intersect the
project area.
The study involved a records search from the South Coastal Information Center (SCIC), a Sacred
Lands File search at the Native American Heritage Commission (NAHC), and an intensive pedestrian
inventory. The SCIC records search indicated that a total of seven previously recorded cultural
resources intersect the proposed APE, including four prehistoric sites (CA-SDI-4933, CA-SDI-8604,
CA-SDI-8605, and CA-SDI-13486), two historic sites (CA-SDI-11096H and CA-SDI-11948H), and one
prehistoric isolate (P-37-034104). During early conversations with OHP, a newly recorded
multicomponent site (CA-SDI-23075) was also identified as intersecting the project area.
During the intensive pedestrian field survey, no artifacts were encountered within or immediately
surrounding the previously defined boundaries of the four prehistoric sites or the multicomponent
site. The four prehistoric sites have been formally evaluated for listing in the National Register of
Historic Places (NRHP) and the California Register of Historical Resources (CRHR); they were
recommended not eligible and have received OHP concurrence. The multicomponent site, CA-SDI-
23075, underwent subsurface testing under a previous survey effort for a different project
completed under contract for USIBWC; however, the testing was to determine the presence or
absence of cultural deposits in that project's APE and was not considered sufficient to formally
evaluate the site for NRHP eligibility.
Historic artifacts and features associated with CA-SDI-11096H were recorded outside the
previously defined boundaries during the survey and correspond with the now demolished
structures visible in the area's historic aerials. The site boundary was modified to reflect the actual
location of the previously recorded house, a cobble wall, and historic/modern-period demolition
debris. Multiple cobble wall sections associated with CA-SDI-11948H that had previously been
recorded were identified along with a wire winch wheel and motor with a concrete foundation. The
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site boundary for CA-SDI-11948H was also revised to encompass the distribution of historic-period
features more accurately. Formal evaluations of these sites have not yet been conducted.
One new cultural resource was identified just east of CA-SDI-11096H, consisting of a low cobble and
mortar wall with two 4-ft-tall pillars near the center that once served as the entrance to the
Windover Ranch during the early to mid-twentieth century. A primary record for the resource was
submitted to the SCIC and was assigned the permanent designation of P-37-39462. No other
features or artifacts were identified in association with this resource.
The prehistoric isolate shell fragment, P-37-034104, was relocated during the pedestrian survey
and was in the same condition as previously recorded. The shell was likely redeposited during
previous flooding events. Isolated resources are categorically not eligible for listing in the NRHP,
and P-37-034104 does not require further consideration.
Table 3-9. Summary of Cultural Resources Intersecting the Project Area
Primary No.
P-37-
Trinomial No.
CA-SDI-
Recording Archaeologist/Firm and Year
Recorded or Updated
Description
NRHP Eligibility
Status
P-37-004933
CA-SDI-4933
Higgins 1994; Carrico et al. 1996; Higgins et
al. 1994; Widell 1994; Carrico and Serr 1996;
Case 1996; Carrico et al. 1996b; Widell 1996;
Polan 1981; Gallegos et al. 1986; Carrico
1996a; Carrico 1996b; SWCA 2004; Wilson et
al. 2014; Anaya 2019
AP2 (Lithic scatter);
AP15 (Habitation
debris)
Recommended
Ineligible for
NRHP and CRHR
P-37-008604
CA-SDI-8604
ASM Affiliates 1989; Higgins 1994; Pigniolo
and Baksh 1999; Higgins et al. 1994; USAC03
1992; Gallegos et al. 1986; Pigniolo et al.
2001; SWCA 2004; Wilson et al. 2014
AP2 (Lithic scatter)
Recommended
Ineligible for
NRHP and CRHR
P-37-008605
CA-SDI-8605
Cheever and Gallegos 1987; ASM Affiliates
1989; Higgins 1994; Higgins et al. 1994;
Turnbow 1994; Turnbow et al. 1995; USAC03
1992; Polan 1981; Gallegos et al. 1986; Cook
et al. 2003; SWCA 2004; Hector 2006; Becker
2011; Wilson et al. 2014; Foglia 2018
AP2 (Lithic scatter)
Recommended
Ineligible for
NRHP and CRHR
P-37-011096
CA-SDI-
11096H
ASM Affiliates 1989; Manley 1993; City of
San Diego 1994; Higgins 1994; Higgins et al.
1994; SWCA 2004; Hector 2006; Becker
2011; Wilson et al. 2014; Foglia 2018
HP2 (Single-family
property)
Unevaluated
P-37-011948
CA-SDI-
11948H
Higgins 1994; Higgins et al. 1994; Widell
1994; Cook et al 2003; SWCA 2004; Becker
2011; Hector 2006; Wilson et al. 2014
AH2 (Foundations);
AH11 (Wall/fence)
Unevaluated
P-37-013486
CA-SDI-13486
Higgins 1994; Higgins et al. 1994; Turnbow
1994; Turnbow et al. 1995; Cook et al. 2003;
SWCA 2004; Berryman and Rosenberg
2010a; Berryman and Rosenberg 2010b;
Whitaker 2011; Wilson et al. 2014; Tennesen
2018; Anaya 2019
AP2 (Lithic scatter)
Recommended
Ineligible for
NRHP and CRHR
P-37-034104
N/A
ASM 2013
AP16 (Isolate shell)
Ineligible
P-37-039926
CA-SDI-23075
Sayre and Wesson 2020
AP2 (Lithic scatter);
AH 16 (Other)
Unevaluated
P-37-039462
N/A
ASM 2022
AH11 (Wall/fence)
Unevaluated
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3.8 Visual Resources
The Tijuana River Valley is a scenic estuary area surrounded by urban area to the north, east, and
south and the Pacific Ocean to the west The valley is primarily undeveloped and includes several
parks and hiking trails to promote enjoyment of the natural beauty. To the west of the Tijuana River
Valley are undeveloped coastline and beaches with unobscured views of the ocean. The mesas
along the border with Mexico afford desirable views across the varying landforms, including views
of the ocean and beaches to the west, the Tijuana River Valley to the north, and neighboring mesas.
The City of San Diego General Plan and neighboring San Ysidro and Tijuana River Valley Community
Plans work together to provide general guidance and address more specific issues at a community
level, including visual resource considerations (City of San Diego, 2021c). The San Ysidro
Community Plan and Local Coastal Program Land Use Plan identifies five scenic overlooks along or
near Camino de la Plaza, close to the sod farm, which all look towards the Tijuana River Valley, a
designated open space, and the Pacific Ocean (City of San Diego, 2017).
Other state laws focus on protecting visual and scenic resources by regulating development in areas
considered to be of high scenic quality. These include the CCA, which includes provisions about
protecting visual or scenic resources within the Coastal Zone. Steep hillsides, which are potential
visual resources,35 are present in Smuggler's Gulch, around the mesas, along Monument Road, and
along portions of the U.S.-Mexico border. Additionally, the portion of Interstate 5 that is northeast
of the project area is eligible to be, but not yet designated, a State Scenic Highway per the California
Department of Transportation (Caltrans) under the California Scenic Highway Program (Caltrans,
2018).
Light sources in the area include nearby residential and commercial lights, with street lighting
present along roadways and in parking lots. Lights are present in the parking lots at the ITP and
SBWRP. There is limited lighting in Smuggler's Gulch and Goat Canyon. Lights are also managed by
CBP as part of the border wall infrastructure in the region (CBP, 2018).
The ITP parcel and the Tijuana River main channel are surrounded by residential urban areas to the
east and south and by natural, open space areas to the north and west. The scenic Tijuana River and
Tijuana River Valley downstream of Dairy Mart Road are generally not visible from the ITP and
SBWRP parcels. Mesa landforms are visible to the west of this area. Smuggler's Gulch and Goat
Canyon are surrounded by natural areas, with steep hillsides characteristic of mesa landforms to
the east and west North of Smuggler's Gulch is private land that is primarily used for agriculture.
See Section 6.1.8 (Visual Resources) for information about regulations protecting visual and scenic
resources.
35 The Tijuana River Valley Local Coastal Program Land Use Plan identifies steep hillsides as potential visual
resources. The San Diego Environmentally Sensitive Lands Regulations regarding steep hillsides apply to
proposed development on a site containing portions with 1) a natural gradient of at least 25 percent and a
vertical elevation of at least 50 feet, or 2) a natural gradient of at least 200 percent and a vertical elevation of
at least 10 feet (City of San Diego, 2004).
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3.9 Land Use
The Tijuana River Valley is surrounded by developed, urbanized areas that are part of the City of
Imperial Beach to the north, the City of San Diego to the north and east, and the City of Tijuana,
Mexico to the south. San Ysidro, a district of San Diego, is located to the northeast of the Tijuana
River main channel. The majority of the developed land in the U.S. bordering the open space of the
valley is occupied by single-family residential buildings to the north, northeast, and east. Multi-
family residential dwellings and other mixed uses are located along Interstate 5. Immediately to the
east of the north levee is Coral Gate, a single-family residential community, and the Las Americas
Premium Outlets, a regional shopping center. Bordering the south of the valley are communities in
Tijuana called delegaciones, which include Playas de Tijuana, Centro, and Otay-Centenario (from
west to east). These are highly populated areas consisting of mixed residential and commercial
uses. Industrial areas along the border in Mexico are concentrated around the port of entry and the
Tijuana River.
Within the Tijuana River Valley, which is predominantly used for recreational purposes, there are
three parks: Border Field State Park, Tijuana River Valley Regional Park, and the USFWS Tijuana
Slough NWR Border Field State Park, owned and managed by the CDPR, is located along the coast
and encompasses a portion of Goat Canyon. The Tijuana Slough NWR, also located along the
coastline, is bordered by the City of Imperial Beach to the north and encompasses the majority of
the Tijuana River Estuary. Most of the rest of the valley downstream of Dairy Mart Road, including
Smuggler's Gulch, is part of the Tijuana River Valley Regional Park, which is owned and managed by
the County of San Diego Department of Parks and Recreation with some exclusions for private
property scattered throughout. Within all three parks, trails (i.e., multi-use trails, equestrian trails,
pedestrian trails, seasonal trails) and various access roads allow the public to access recreational
opportunities such as hiking, horseback riding, biking, wildlife viewing, sightseeing, and picnicking.
A recently opened 79-acre campground in the Tijuana River Valley Regional Park provides the
public with 51 primitive campsites and 10 yurts in addition to a nature center and associated
facilities. There are no parks or trails in the valley upstream of Dairy Mart Road. The Chula Vista
Model Airplane and Radio Control Club leases approximately 20 acres of land owned by USIBWC
just north of the ITP on the floodplain of the main channel. Figure 1-1 in Section 1.1 (Background)
shows the park boundaries.
The TRNERR, a part of the National Estuarine Research Reserve System established by the National
Oceanic and Atmospheric Administration (NOAA), is situated in the valley and serves important
research and educational purposes. The TRNERR overlaps all three parks mentioned above and is
managed through cooperation with California State Parks, USFWS, the City of San Diego, the County
of San Diego, and the U.S. Navy. Policy related to the reserve is coordinated by the TRNERR
Advisory Council (TRNERR, 2020). The TRNERR has participated in activities with the North
American Marine Protected Area Network (NAMPAN) and was a pilot site for a "vital signs"
assessment conducted by NAMPAN (CDPR, USFWS, &NOAA, 2010).
Several privately owned parcels in the valley are used for agricultural purposes, including some
located just north of Smuggler's Gulch along Monument Road and several parcels adjacent to the
City of Imperial Beach to the east of the Naval Outlying Landing Field Imperial Beach. The IBWC-
owned parcel includes approximately 130 acres between Dairy Mart Road, the Tijuana River, and
the north levee that are currently used as a sod farm. The California Farmland Mapping and
Monitoring Program has designated this sod farm as prime farmland (California Department of
Conservation, 2016). The Tijuana River Community Garden, managed by the Resource
Conservation District (RCD) of Greater San Diego County, is located within the Tijuana River Valley
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Regional Park just north of the river at the corner of Hollister Street and Sunset Avenue (RCD of
Greater San Diego County, 2020). The river main channel, Smuggler's Gulch, and Goat Canyon
contain no agricultural uses.
The Tijuana River Valley has historically been used for sand and gravel extractive operations,
specifically in areas east of Border Field State Park and south of Monument Road (Parsons, 2005).
The Mineral Land Classification system established by the California Surface Mining and
Reclamation Act of 1975 designates the Tijuana River Valley as a combination of Mineral Resource
Zones (MRZ) 2 and 3. MRZ-2 designates areas where adequate information indicates significant
mineral deposits are present or there is a high likelihood of presence; MRZ-3 designates areas
containing mineral deposits for which significance has not been evaluated (City of San Diego,
2008c). The Nelson Sloan Quarry (also known as the Border Highlands Pit) is located on county
land immediately west of the SBWRP and east of Smuggler's Gulch on the mesa landform. The
quarry is no longer active and has undergone reclamation. The CDPR is planning to restore this site
to a natural landform and habitat for beneficial reuse/disposal of excess sediment excavated from
flood control facilities and disturbed habitats in the Tijuana River Valley (CDPR, 2021). The
southwest quadrant of the ITP parcel was previously used as a sand and gravel quarry (Parsons,
2005) but is currently used by CBP as a construction staging area for border infrastructure projects.
Portions of the Tijuana River Valley and nearby coastal areas also support Navy operations and
border protection. The Naval Outlying Landing Field Imperial Beach is located north of the
TRNERR, within the city limits of Imperial Beach. The landing field, part of Naval Base Coronado,
handles overflow helicopter squadrons from Naval Air Station North Island in San Diego and
conducts much of the Navy's West Coast helicopter training (City of Imperial Beach, 2019). Navy
facilities along the coastline north of the Tijuana River, including Naval Base Coronado, support
SEAL training activities. CBP maintains the border fence and shares responsibilities with USIBWC
for maintaining the canyon flow diversion structures. CBP utilizes informal trails to conduct patrols
in the Tijuana River Valley (Nordby, 2018). In accordance with a 1980 Memorandum of
Understanding with IBWC, CBP also maintains property along the Tijuana River channel by
conducting mechanical removal of vegetation to preserve line of sight (CBP, 2017).
The Tijuana River and adjacent floodplains upstream of Dairy Mart Road and the ITP parcel are
owned by USIBWC, a federal entity. Smuggler's Gulch is located on land owned by the County of San
Diego, and a small portion by the border is federally owned land. Goat Canyon is located on land
owned by the State of California, the County of San Diego, and the federal government (small
portion by the border). Figure 3-19 shows the land ownership in the Tijuana River Valley.
Land use plans that have been established in Tijuana River Valley and/or the vicinity include the
following:
• City of San Diego Multiple Species Conservation Program Subarea Plan (1997). The
areas affected by the Proposed Action are located within the Southern Area of the MSCP
Subarea Plan and are within the MHPA. Utility lines and roads, limited water facilities, and
other essential public facilities are considered conditionally compatible with the biological
objectives of the MSCP and thus would be allowed within the city's MHPA. The plan also
identifies water quality, including sewage, as a priority issue for the Tijuana River Valley.
See Section 3.4 (Inland Biological Resources) for additional information about MSCP
species.
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Policies and guidelines in this plan (e.g., Construction and Maintenance; Fencing, Lighting,
and Signage; Materials Storage Policies; Land Use Adjacency Guidelines) may apply to the
Proposed Action depending on coordination with the City of San Diego.
• Tijuana River Valley Local Coastal Program Land Use Plan (2007). The areas affected
by the Proposed Action are covered by this plan and are designated as either Utility or as
Multi-Species Conservation Open Space land uses. The activities associated with the
Proposed Action generally fit within approved uses and even help support some of the
management goals identified in the plan.
• City of San Diego General Plan (2008a). The General Plan designates areas affected by the
Proposed Action as Park, Open Space, & Recreation; Agriculture; and Institutional & Public
and Semi-Public Facilities. The Tijuana River Valley is in Planning Area 50 and is specified
as a Proposition A land where a Managed Growth Initiative applies. The activities associated
with the Proposed Action generally fit within approved uses, support many of the identified
goals, and even help address some of the management issues identified in the various
elements within the General Plan.
• County of San Diego General Plan: A Plan for Growth, Conservation, and Sustainability
(2011) (Chapter 3: Land Use Element). This plan only applies to unincorporated areas in
the County of San Diego. The Proposed Action is outside the boundaries of the land covered
in this plan.
• San Ysidro Community Plan and Local Coastal Program Land Use Plan (2017). This
plan covers the San Ysidro Community, which is located to the east of areas affected by the
Proposed Action. While the Proposed Action does not take place within the borders of the
San Ysidro community, this plan identifies scenic overlooks and vistas that overlook the
Tijuana River Valley and areas affected by the Proposed Action. See Section 3.8 (Visual
Resources) for more information on the overlooks.
• County of San Diego Local Coastal Program Land Use Plan (2018). This plan only
applies to a narrow strip of land within the coastal zone that is also located within
unincorporated areas in the County of San Diego. All project areas are outside the
boundaries of the land covered in this plan.
• City of Imperial Beach General Plan/Local Coastal Program Land Use Plan (2019).
This plan area is located downstream of the project area in the City of Imperial Beach. The
Proposed Action does not take place directly on land covered by the plan; however, beach
and ocean areas in Imperial Beach are downstream of the Proposed Action and would be
impacted by the Proposed Action. The activities associated with the Proposed Action
generally fit within the guidance of the plan and help address some of the management
issues identified in the plan.
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TIJUANA RIVER
ESTUARY
PACIFIC
OCEAN
l_ j Tijuana River Valley
Parcel ownership
Private/Other
City of San Diego
County of San Diego
State of California
Federal
CJ.T*£S !• -
IMPERIAL BEACH
OJAYlM ESA,
NAVAL OUTLYING
LANDING FIELD
IMPERIAL BEACH
jSANj|YSIDRO'
IMonumentlRal
'caminoidg)
UNITED state s_
Y" MEXICO - ,
DOWNTOWN
^TlfU^A ij
SAN
DIEGO
IMPERIAL
BEACH -
CHULA
VISTA
Figure 3-19. Land Ownership in the Tijuana River Valley
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3.10 Coastal Zone
Per the CCA, the California coastal zone "is a distinct and valuable natural resource of vital and
enduring interest to all the people and exists as a delicately balanced ecosystem" (PRC § 30001(a)).
The CCA defines the coastal zone as "extending seaward to the state's outer limit of jurisdiction,
including all offshore islands, and extending inland generally 1,000 yards from the mean high tide
line of the sea. In significant coastal estuarine, habitat, and recreational areas it extends inland to
the first major ridgeline paralleling the sea or five miles from the mean high tide line of the sea,
whichever is less, and in developed urban areas the zone generally extends inland less than 1,000
yards" (PRC §30103).
As shown in Figure 3-20, the coastal zone encompasses the entire Tijuana River Valley, adjacent
coastal areas, and additional portions of the City of Imperial Beach and San Ysidro. The policies of
the CCA shape the conservation and management of many resources and features in the Tijuana
River Valley, including (but not limited to) wetlands, estuaries, shorelines, wildlife habitat,
recreational areas, and scenic vistas. Specific coastal resources in the vicinity of the project areas,
and the baseline impacts to these resources caused by contaminated transboundary flows, are
discussed throughout relevant subsections of Section 3 (Affected Environment) of this PEIS.
Federal lands, including the ITP parcel and the flood control areas upstream of Dairy Mart Road, are
excluded from the coastal zone (16 U.S.C. § 1453).
See Section 6.1.9 (Coastal Zone) and Appendix H (Coastal Consistency Determination) for additional
details about the federal Coastal Zone Management Act (CZMA), federal consistency
determinations, the CCC authority, regulations, and review processes for development in coastal
zones, including Coastal Development Permits (CDPs) and Local Coastal Programs (LCPs).
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I _ I Coastal zone
] City of Imperial Beach Local Coastal Program
City of San Diego Local Coastal Program
Federal property (excluded from coastal zone)
~
' c.nY,PF: ¦¦¦•
IMPERIAL* BEACH
—
NAVAL OUTLYING
LANDING FIELD
IMPERIAL BEACH
SAN Y5IDRO-
[Satu'rnlBlvtil
¦r?*
WE>2t. HWBBftlBBMWM
v *>~ ,»v
ESs . ¦¦ va: - •>
It • ,, ^
[Monument! RH |
Cam'ino d e
* ' '¦Rift'sBSfs
,V ' UNITED
_< •.
'states
MEXICO
-'downtown
" TIJUANA ¦ v
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Tijuana
River -
Valley
Figure 3-20. Coastal Zone Boundary and LCP Jurisdictions in the Tijuana River Valley
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3.11 Air Quality and Odor
Regional Air Quality
Air quality in the San Diego region is variable and is dependent on factors including meteorological
conditions, local pollutant emissions, and transported pollution from adjacent regions.
Photochemical smog, including ozone (O3), can occur as a result of vehicular emissions of nitrogen
oxides (NOx) and volatile organic compounds (VOCs), particularly during periods of warm, sunny
weather and during temperature inversions that reduce pollutant dispersion in the atmosphere.
Temperature inversions occur in both winter and summer months when warm dry inland air
overlies cool moist marine air, preventing pollutants from rising. Winds blow predominantly from
the west, particularly during summer months. Santa Ana winds (dry downslope winds originating
inland from the east/northeast) can occur, particularly during autumn months. Santa Ana winds
typically blow pollutants out to the ocean, resulting in clear days. Transported pollution from both
the South Coast Air Basin to the north (which includes Los Angeles) and Tijuana, Mexico, to the
south can significantly contribute to ozone levels in San Diego County (SDAPCD, 2020).
The Clean Air Act established National Ambient Air Quality Standards (NAAQS) to protect public
health and welfare from the effects of air pollution. California maintains their own set of air quality
standards (California Ambient Air Quality Standards [CAAQS]) that predate the NAAQS and are, in
some cases, more restrictive than the national standards. Table 3-10 summarizes the NAAQS and
CAAQS. National primary standards are levels of air quality necessary to protect public health, and
national secondary standards are levels of air quality necessary to protect public welfare from any
known or anticipated adverse effects of a pollutant While ozone pollution levels and days of air
quality exceedances in the San Diego region have declined significantly since 1990, San Diego
County is categorized as a severe nonattainment area for ozone (per both the 2008 eight-hour
standard and the 2015 eight-hour standard) and a maintenance area for carbon monoxide (CO)
(EPA, 2022a). See Section 6.1.10 (Air Quality and Odor) for additional information on air quality
regulations.
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Table 3-10. Federal and California Ambient Air Quality Standards
Pollutant
Averaging
Time
National Standard
California Standard
Primary
Secondary
Ozone (O3)
1-hour
—
0.09 ppm (180 ng/m3)a
8-hour
0.0/0 ppm (137 ng/m3)b
Same as primary
0.070 ppm (137 ng/m3)
Respirable particulate
matter (PM10)
24-hour
150 ng/m3
Same as primary
50 ng/m3
Annual
—
—
20 ng/m3
Fine particulate
matter (PM2.5)
24-hour
35 ng/m3c
Same as primary
—
Annual
12.0 ng/m3d
15.0 ng/m3
12 ng/m3
Carbon monoxide (CO)
1-hour
35 ppm (40 mg/m3)
—
20 ppm (23 mg/m3)
8-hour
9 ppm (10 mg/m3)
—
9.0 ppm (10 mg/m3)
Nitrogen dioxide (NO2)
1-hour
100 ppb (188 ng/m3)
—
0.18 ppm (339 ng/m3)
Annual
53 ppb (100 ng/m3)
Same as primary
0.030 ppm (57 ng/m3)
Sulfur dioxide (SO2)
1-hour
75 ppb (196 Hg/m3)
—
0.25 ppm (665 Hg/m3)
3-hour
0.5 ppm (1300 ng/m3)
24-hour
0.14 ppm (370 ng/m3)
—
0.04 ppm (105 ng/m3)
Annual
0.030 ppm (79 ng/m3)
—
—
Lead
30-day
—
—
1.5 ng/m3
Quarter
1.5 ng/m3
Same as primary
3-month
0.15 ng/m3
Same as primary
Visibility reducing
particles
8-hour
No national standard
See footnote e
Sulfates
24-hour
No national standard
25 ng/m3
Hydrogen sulfide (H2S)
1-hour
No national standard
0.03 ppm (42 ng/m3)
Vinyl chloride (C2H3CI)
24-hour
No national standard
0.01 ppm (26 ng/m3)
Source: (CARB, 2021a); 40 CFR § 50.5.
a - ppm = parts per million; ng = microgram.
b - In 2015, EPA strengthened the previous 2008 ground-level ozone standard from 0.075 ppm to 0.070 ppm.
c- In 2006, EPA strengthened the previous 1997 24-hour PM2.5 standard from 65 ng/m3to 35 ng/m3.
d - In 2012, EPA strengthened the previous 1997 annual PM2.5 primary standard from 15.0 ng/m3to 12.0 ng/m3.
The secondary standard was left unchanged.
e - 10-mile visibility standard equal to "extinction of 0.23 per kilometer."
Local Air Quality
As of 2020, the San Diego County Air Pollution Control District (SDAPCD) operated a network of
nine air monitoring stations throughout the county. Two additional monitors, including one in San
Ysidro immediately northeast of Interstate 5, are still in the permitting process (SDAPCD, 2021).
Air quality in the San Ysidro district is known to be greatly impacted by emissions from queues of
idling vehicles at the San Ysidro point of entry (SDAPCD, 2021). This community is also affected by
transboundary air pollution from Mexico, with air quality monitoring showing elevated particulate
levels in the community when downwind of Tijuana (SDAPCD, 2019a). Several efforts—funded and
supported by agencies and organizations including the California Office of Environmental Health
Hazard Assessment (OEHHA), the California Air Resources Board (CARB), EPA Region 9, and
NADBank—have been implemented in recent years to expand and improve air quality monitoring
in San Ysidro and Tijuana near the border. Goals of these efforts include measuring changes in
pollutant levels, identifying highly affected areas in San Ysidro, and identifying potential mitigation
strategies through community engagement. Additionally, in response to Assembly Bill (AB) 617,
CARB established the Community Air Protection Program (CAPP) with the goal of reducing
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pollutant exposure in communities that are heavily impacted by air pollution. In 2022, CARB added
the San Diego International Border Community (encompassing parts of San Ysidro and Otay Mesa
East) to the CAPP and is currently in the process of forming a steering committee to develop and
advise on air quality improvement strategies in this community.
CalEPA's CalEnviroScreen 4.0 tool incorporates available air monitoring data and emissions
estimates to summarize and illustrate, at the census tract level, community exposure to air
pollutants including ozone (based on 2017-2019 monitoring data), PM2.5 (based on 2015-2017
monitoring data), and diesel PM (based on emissions estimates) (CalEPA, 2021b). Estimated PM2.5
exposures in the Tijuana River Valley and San Ysidro areas are among the highest in the state, with
estimated exposures to diesel PM also being elevated in San Ysidro and eastern portions of the
Tijuana River Valley. See Section 3.20 (Environmental Justice) and Appendix I (Supplemental Data
for Environmental Justice Analysis) for additional information. However, while the county is a
nonattainment area for ozone, the CalEnviroScreen tool identifies the Tijuana River Valley and
adjacent areas to the north as having relatively low exposure to ozone as compared to the county
and state as a whole.
The aerosolization of estuary and ocean water also presents air quality concerns, as contaminated
water can migrate inland, carrying pathogens and other impurities along with it See Section 3.16
(Public Health and Safety) for more information regarding recent and ongoing local research into
this topic.
Odor
Under Regulation IV Rule 51 of the SDAPCD, the discharge of air contaminants is prohibited if such
as discharge would cause "injury, detriment, nuisance or annoyance to any considerable number of
persons or to the public." Under this rule, an odor is considered a nuisance based on the number of
complaints received by the SDAPCD. Odor from WWTPs is caused primarily by H2S gas, which is
created from sulfide-containing compounds under anaerobic conditions and characterized by a
distinctive "rotten egg" smell.
Odor studies were conducted in 1997 and 2002. The 1997 study assessed odor-producing sources
within the Tijuana River Valley, including the ITP, the buffer area between Mexico and the U.S.,
Stewart's Drain, and the Coral Gate development. The ITP was found to be operating well within the
SDAPCD H2S permit limit of 42 ng/m3. Strong odors were detected at Stewart's Drain (east of the
ITP), the intersection of Dairy Mart Road and Camino de la Plaza, and several areas of standing
water (Parsons, 2005). The 2002 study found that H2S concentrations at all sampling locations
were within SDAPCD limits. One odor complaint was filed with the SDAPCD in May 2003
concerning the operation of the ITP, but upon investigation, the source of the odor was determined
to be the Tijuana River, caused by the pump station at the U.S.-Mexico border that had been
malfunctioning for five months (Parsons, 2005). EPA and USIBWC do not have any records of more
recent odor studies or public complaints of odor originating from the ITP. The main cause of odor
complaints within the Tijuana River Valley appears to be the Tijuana River itself, rather than the
WWTPs. Odor concerns due to untreated wastewater and standing water in the Tijuana River and
pilot channel (e.g., near the southern Hollister Street bridge) persist among residents and
researchers.
Sensitive Receptors
The City of San Diego's CEQA Significance Determination Thresholds for air quality and odor define
a sensitive receptor as "a person in the population who is particularly susceptible to health effects
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due to exposure to an air contaminant than is the population at large." These guidelines identify
long-term care facilities (e.g., hospitals, convalescent centers, retirement homes), residences (e.g.,
medical patients in homes), schools, playgrounds, childcare centers, and athletic facilities as
examples of sensitive receptors (City of San Diego, 2016a).
No long-term care facilities or public or private schools are located within the Tijuana River Valley.
Several parks, playgrounds, and athletic facilities are located within approximately 1 mile of the ITP
parcel. It is unknown whether sensitive receptors occupy any of the few residences along
Monument Road or Dairy Mart Road south of Interstate 5.
ITP Operations
Permitted emission units at the ITP include two diesel engines: one 3,057-horsepower (hp) engine
driving a 2,000-kW electric generator and one 2,151-hp engine, also driving an electric generator.
The generators are for emergencies only and are not to be operated for non-emergency events such
as demand response (SDAPCD, 2011b, 2019b). The ITP has not experienced any unplanned power
outages within the past five years requiring use of the emergency generators. The ITP also includes
four odor control scrubbers (SDAPCD, 2011a).
3.12 Climate
Regional Climate
Coastal portions of the San Diego region feature a mild Mediterranean regional climate influenced
by the Pacific High, a semi-permanent, high-pressure area in the eastern Pacific Ocean that causes
summer storms to be directed north, allowing for clear skies in the summer months. Summers are
warm and dry with moderate temperatures ranging from 61 to 79 °F with a seasonal mean of 70 °F.
Fog forms regularly during the night and early morning over the coast, often penetrating inland.
Winters are mild and wet with temperatures ranging from 45 to 67 °F with a seasonal mean of 56
°F. Highest precipitation occurs from November through March. Annual precipitation over the past
20 years has averaged 9.6 inches (NOAA, 2021a). Table 3-11 summarizes precipitation and
temperature data over the past five years for the closest weather station.
Table 3-11. Summary of Weather Data for Brown Field Municipal Airport
Year
Annual Average
Precipitation
(Inches)
Temperature
Annual Average
(°F)
Average Daily Max
(°F)
Average Daily Min
(°F)
2016
11.23
64.5
74.7
54.4
2017
10.1
64.4
74.8
54.0
2018
7.01
64.6
74.5
54.7
2019
18.48
62.2
72.0
52.5
2020
9.67
64.1
75.1
53.3
Source: (NOAA, 2021a).
Climate Change and Greenhouse Gas (GHG) Emissions
Global climate change has led to several trends in the southwestern U.S., including rising
temperatures, more frequent and severe droughts and wildfires, and sea level rise (USGCRP, 2018).
Climate change concerns in southern California include more frequent and prolonged droughts;
more frequent and severe wildfires; rising temperatures and more frequent extreme heat episodes;
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competing water demands; sea level rise; and ocean changes including ocean warming, ocean
acidification, and reduced ocean oxygen (USGCRP, 2018). Climate change is reducing renewable
surface water and groundwater resources along the U.S.-Mexico border, and much of northern and
central Mexico are currently under high or very high levels of water stress (Good Neighbor
Environmental Board, 2016). Additionally, in the U.S.-Mexico border region, impoverished
communities are especially vulnerable to climate change impacts such as drought, rising
temperatures that intensify health effects of air pollution, and extreme weather events (Good
Neighbor Environmental Board, 2016).
Coastal vegetative ecosystems, such as the Tijuana River Estuary, naturally sequester large
quantities of carbon. Due to their high productivity and rapid sedimentation, ecosystems including
mangroves, salt marshes, and sea grass beds can sequester more carbon per unit area than
terrestrial forests, while providing co-benefits such as protection from sea level rise. The
conservation and restoration of coastal marine ecosystems has emerged as a prominent strategy
for mitigating and adapting to climate change.
Greenhouse gases (GHGs), which trap heat in the atmosphere, are emitted from a wide variety of
natural and anthropogenic sources, including burning of fossil fuels and other materials and
methane emissions from agricultural practices or decay of organic materials. GHGs include carbon
dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases (hydrofluorocarbons,
perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride). In California, total 2019 emissions
equaled 418.2 million metric tons of carbon dioxide equivalent (C02e). Major emission sources
include the transportation (41 percent), industrial (24 percent), and electric power sectors (9
percent) (CARB, 2021b).
The City of San Diego recently released their 2022 Climate Action Plan, which builds upon the
progress of the previous 2015 Climate Action Plan. The new Climate Action Plan sets an ambitious
goal of achieving net-zero GHG emissions by 2035 and establishes an intermediate target of 61
percent below 2019 levels by 2030. The plan identifies six strategies to achieve this goal:
Decarbonization of the Built Environment, Access to Clean and Renewable Energy, Mobility and
Land Use, Circular Economy and Clean Communities, Resilient Infrastructure and Healthy
Ecosystems, and Emerging Climate Action. As part of these strategies, the plan sets goals for
diverting waste streams to landfills and acknowledges the GHG contributions of WWTPs in the
city's Metropolitan Sewerage System.36 The City of San Diego's 2019 baseline emissions were
estimated at 10.5 million metric tons of C02e. Major emission sources in 2019 included on-road
transportation (55 percent), electricity consumption (22 percent), and direct natural gas use (18
percent) (City of San Diego, 2022b). See Section 6.1.11 (Climate) for information about
requirements for analyzing the impact of GHGs as directed under EO 14008, Tackling the Climate
Crisis at Home and Abroad (86 FR 7619), under CEQA, and in consistency with local climate action
plans.
Existing sources of GHG emissions in the project area include Scope 1 emissions from operation of
emergency generators at the ITP (see Section 3.11 [Air Quality]); Scope 2 emissions associated with
36 The ITP is not part of the city's municipal sewer system, but the neighboring SBWRP is included.
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electricity use (see Section 3.14 [Energy]); and Scope 3 mobile source emissions from ITP employee
commuting and hauling of dry solids waste by truck (see Section 3.17 [Transportation]).37
3.13 Solid and Hazardous Waste
Solid waste includes trash; garbage; refuse; sludge from a waste treatment plant, water supply
treatment plant, or air pollution control facility; and other discarded material resulting from
household, government, industrial, medical, commercial, mining, and agricultural operations, and
from community activities. Hazardous waste is defined as a solid waste or combination of solid
wastes which 1) may cause or significantly contribute to an increase in mortality or illness or 2)
may pose a substantial present or potential hazard to human health or the environment when
improperly managed (42 U.S.C § 6903). Hazardous and nonhazardous solid wastes are regulated by
federal, state, and local laws, as described in Section 6.1.12 (Solid and Hazardous Waste).
Trash and Debris
Trash is a major human health and environmental concern in the Tijuana River Valley. Trash
impairs the beneficial uses of the watershed, including fishing and water recreation. Some trash can
be a significant source of bacteria, viruses, and toxic substances, which can result in beach closures.
Broken glass or sharp metal fragments can cause puncture or laceration injuries. Trash can also
impair and clog drainage infrastructure contributing to flood and human hazards. Trash in the
Tijuana River Valley also threatens wildlife by impairing aquatic and wetland habitats; disrupting
spawning, reproduction, and/or early development of aquatic organisms; and inhibiting growth of
aquatic and wetland vegetation (Tetra Tech, 2009). Discarded tire waste is a major trash source in
the Tijuana River Valley. Studies on plastic and tire leachates in various water ecosystems highlight
toxic effects on wildlife, including restricted algae growth and embryonic development in mussels
within the Mediterranean Sea (Capolupo etal., 2020). A recent study by Tian etal. (2021) identified
disposed tire rubber as a potential source of 6PPD-quinone, a highly toxic transformation
byproduct of the antioxidant 6PPD, which is commonly used in tires. The authors found 6PPD-
quinone to be contributing to increased juvenile mortality of coho salmon in the Pacific Northwest
(Tian etal., 2021).
In 2009, URS Corporation conducted a physical survey of trash in the current and historical
channels of the Tijuana River and its floodplain and tributaries. Across the entire survey area, trash
tended to accumulate in areas where other trash or vegetation served as physical barricades to
surface water flow or in areas where decreased flow velocity allowed debris to drop out of
suspension (URS, 2010). Surveyed areas with the highest density of surface trash included the high-
water area just east of Dairy Mart Road, particularly at the northeast corner of the Dairy Mart Road
Bridge. The most prevalent types of trash and debris by weight were tires (30 percent); organic
37 GHG emissions are classified as Scope 1 (direct emissions), Scope 2 (indirect emissions from purchased
energy), and Scope 3 (other indirect emissions). Scope 1 emissions include emissions from direct fossil fuel
combustion, such as in the operation of boilers, generators, incinerators, and vehicles operated by the
organization, as well as fugitive emissions of refrigerants and other GHGs (e.g., fire suppressants). Scope 2
emissions include upstream emissions from purchased electricity, steam, heating, and cooling. Scope 3
emissions include all other indirect emissions not included in Scope 2, such as emissions from employee
commuting and business travel, transmission and distribution losses associated with purchased electricity,
methane emissions from contracted solid waste disposal, methane and nitrous oxide emissions from
contracted wastewater treatment, and upstream emissions associated with purchased products and services.
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debris, including leaves, grass, sediment, branches, stumps, and textiles (19 percent); lumber (17
percent); and plastic (15 percent) (URS, 2010). Plastics generally have low density, making their
weight contribution particularly notable. URS also found evidence of illegal dumping in the valley
along residential and commercial areas at the northern edge of the floodplain, particularly near
Dairy Mart Road (URS, 2010).
While the study described above surveyed quantities of trash accumulated in selected locations, no
studies have yet focused on estimating quantities of trash conveyed across the border during wet-
and dry-weather flows (HDR, 2020c). To approximate the annual trash load in transboundary
flows, HDR applied the volumetric fraction of trash in the dredged sediment from the Goat Canyon
sediment basins to the annual sediment yield to both sources. HDR developed a very conservative
estimate that 10 percent of the dredged sediment by volume is trash (HDR, 2020c). This estimate,
when applied to the Tijuana River main channel and Smuggler's Gulch sediment yields estimated by
PG Environmental (PG Environmental, 202If), produces annual trash load estimates of 15,000
cubic yards and 1,800 cubic yards, respectively.
Trash accumulation patterns in both Smuggler's Gulch and Goat Canyon are influenced by existing
infrastructure in the canyons. Trash booms were installed in Smuggler's Gulch in 2019 (HDR,
2020c). In addition, CBP has identified concerns with the amount of trash that accumulates in the
canyon flow diversion structures during wet-weather conditions. Thin layers of trash, likely
deposited during storm events, were also observed in the sidewalls of the excavation of Smuggler's
Gulch in 2009. During a subsequent field study, trash was found in Smuggler's Gulch in sediment
cores collected below the water table (deeper than 12 feet) (URS, 2010). In Goat Canyon,
substantial densities of trash were observed in the sediment basins during a previous trash survey
(URS, 2010). Existing trash booms in Goat Canyon capture the majority of floating trash, which is
removed during sediment removal operations at the nearby sediment basins (HDR, 2020c).
Ground Contamination and Cleanup
One soil contamination site, located in the southwest quadrant of the ITP parcel, is within the
immediate vicinity of the Proposed Action. This portion of the ITP parcel includes the 43-acre
former Hofer site purchased by USIBWC in 1999, which was used as a dairy farm and later for game
bird ranching, scrap metal salvage, auto repair, feed storage, and fertilizer processing. Former uses
of the site contaminated the soil in some areas with lead, and in one area with polychlorinated
biphenyls. In 1997, a Phase II Environmental Site Assessment found that soil contaminants were
not above hazardous waste levels. Groundwater sampling at various locations on the property
identified low concentrations of heavy metals and VOCs, but none were detected at levels above
state action levels for drinking water (Parsons, 2005). Following the assessment, contaminated
soils were removed from the site, and four monitoring wells and one water production well were
removed. The SWRCB California GeoTracker database identifies the former Hofer property as the
site of a spill of unspecified contaminants reported in December 1991 to the San Diego Local
Oversight Program. According to GeoTracker, the contamination event has been cleaned up, and the
case has since been closed (SWRCB, 2020).
Wastewater Treatment Process Solids
Existing wastewater treatment processes at the ITP produce solid waste. The ITP is designed to
treat an average daily flow of 25 MGD (30 MGD peak), and treated secondary effluent is discharged
via the SBLO/SBOO to the Pacific Ocean. The ITP produces an average of 11,000 tons/yr of primary
sludge dry solids—including approximately 600 tons/yr of sediment and trash by way of screening
and grit removal—and 8,000 tons/yr of secondary (waste activated) sludge dry solids (PG
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Environmental, 2021c). These solid wastes are trucked to a disposal facility in Punta Bandera,
Mexico, approximately 4.2 miles (10 miles by road) south of the international border. The disposal
facility includes eight sludge disposal cells, each with a capacity of 23,700 cubic meters per year
(EPA, 2009). It is EPA's understanding that these disposal cells are currently being operated at near
capacity, and that logistical difficulties with transporting sludge to Mexico via truck are limiting the
plant's ability to effectively remove sludge from the site. Authorities in Mexico are currently
investigating disposal site alternatives to replace the Punta Bandera disposal facility once it ceases
operations.
Solid waste disposal facilities in the region that can accept solids from wastewater facilities include
those listed in Table 3-12. The Miramar Landfill, located approximately 25 miles from the ITP and
north of the City of San Diego, currently serves as the disposal site for sediment removed from the
Goat Canyon sediment basins managed by California State Parks. Of the five facilities considered
below, two were determined early on to be not viable options for accepting additional waste from
the Proposed Action: Miramar Landfill because of expected impacts to its anticipated closure date
and East Otay Mesa Recycling Collections Center and Landfill because it is not yet approved and
operational.
Table 3-12. Regional Disposal Facility Information
Disposal Facility
Owner/Operator
Driving
Distance from
ITP (Miles)
Remaining
Capacity3
Projected Cease
Operation Date
Considered for
the Proposed
Action
Punta Bandera (Punta
CESPT
10
Unknown
Estimated 2024
Yes
Bandera, MX)
Miramar Landfill (San
U.S. Department
25
11,080,871 cubic
1/1/2031
Yes, but not
Diego, CA)b
of the Navy/City
of San Diego
yards (2020)
viable
Sycamore Landfill
Republic Services
29
113,972,637 cubic
Estimated 2072
Yes
(Santee, CA)
yards (2016)b
Otay Landfill (Chula
Republic Services
9
21,194,008 cubic
Estimated 2032
Yes
Vista, CA)
yards (2016)b
East Otay Mesa
Not yet
11.5
180 million tons
N/A
Yes, but not
Recycling Collection
determined
viable
Center and Landfill
(San Diego County,
CA) (Proposed)c
a - Year in parentheses indicates the date of the most recent available estimate,
b - Source: (CalRecycle, 2022).
c - Source: (County of San Diego, 2022).
3.14 Energy
The Tijuana River Valley, including the ITP, is served by San Diego Gas & Electric (SDG&E). SDG&E
provides natural gas and electricity to San Diego County and southern Orange County in California.
SDG&E's 2018 electric power mix consisted of 43 percent renewable energy (21 percent wind, 20
percent solar, 2 percent biomass and biowaste), 29 percent natural gas, 27 percent unspecified
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sources of power,38 and less than 1 percent other sources. Baja California and California share two
cross-border electrical interconnection lines, including a connection between Tijuana and Otay
Mesa (Good Neighbor Environmental Board, 2019).
The ITP is connected to the existing power grid and purchases power from SDG&E. The ITP used
9.99 gigawatt-hours (GWh) at a total cost of $1.96 million during the six-month period from
February 25, 2020, to August 25, 2020 (SDG&E, 2020). Using this example timeframe, the annual
electricity demand of the ITP is estimated to be approximately 20.0 GWh/year. The ITP obtains
backup power from two diesel engines: one 3,057-hp engine driving a 2,000-kW electric generator
and one 2,151-hp engine, also driving an electric generator. The generators are for emergencies
only and are not to be operated for non-emergency events such as demand response (SDAPCD,
2011b, 2019b). The ITP has not experienced any unplanned power outages within the past five
years requiring use of the emergency generators. The ITP does not use any natural gas.
There are no electric substations or high voltage transmission lines in the Tijuana River Valley.
There are distribution lines that feed the ITP and SBWRP, including lines that run along Dairy Mart
Road and Monument Road.
3.15 Public Services and Utilities
The Tijuana River Valley area is serviced by utilities from the City of San Diego. The emergency
services that serve the Tijuana River Valley are located in the adjacent communities of Imperial
Beach, Otay Mesa, and San Ysidro. Two major roads, Hollister Street and Dairy Mart Road, provide
emergency vehicle access for the Tijuana River Valley. Monument Road traverses the Tijuana River
Valley east to west and provides the areas west of Smuggler's Gulch with access to emergency
services. During wet-weather events, flooding overtops Monument Road in Smuggler's Gulch and
Yogurt Canyon, which can restrict emergency vehicle access to areas west of the flooded section of
the road.
Emergency Services
The Tijuana River Valley is currently serviced by the Southern Division of the City of San Diego
Police Department. The department headquarters is located east of the Tijuana River Valley, in the
Otay Mesa West Area.
The Tijuana River Valley is currently serviced by the City of San Diego Fire Department and is split
between two fire districts. Fire District E29 services areas east of Camino de la Plaza, including San
Ysidro. Fire District E30 services areas west of Camino de la Plaza and the Nestor/South San Diego
areas.
The Tijuana River Valley is currently served by two area hospitals, San Ysidro Health Otay and
Sharp Chula Vista Medical Center, which are located northeast of the Tijuana River Valley area in
the San Ysidro and Chula Vista communities. Two urgent care facilities, South Bay Urgent Care and
U.S. Healthworks-Chula Vista, are located north of the Tijuana River Valley in the Imperial Beach
38 "Unspecified sources of power" refers to electricity from transactions that are not traceable to specific
generation sources (California Energy Commission, 2019). This could include purchased/imported power.
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and Chula Vista communities. Most of the Tijuana River Valley is serviced by the San Diego
Ambulance Service, with the South 5 Ambulance Service Area servicing areas near Yogurt Canyon.
Binational emergency services, those that address responses to hazardous materials incidents
within a two-mile radius of the U.S.-Mexico border, are coordinated in cooperation between the
cities of San Diego and Tijuana and the County of San Diego in accordance with a Binational
Hazardous Materials Prevention and Emergency Response Plan. The plan includes hazards
identification along the border, an incident notification system, and procedures for emergency
response operations (County of San Diego, City of San Diego, & City of Tijuana, 2013).
Navy Operations and Border Protection
As discussed in Section 3.9 (Land Use), portions of the Tijuana River Valley and nearby coastal
areas support Navy operations and border protection. Navy operations in this area include those at
Naval Base Coronado, Naval Outlying Landing Field Imperial Beach, and Silver Strand Training
Complex. Under current conditions, contaminated transboundary flows hinder Navy activities and
infrastructure as described in Section 1.3.2 (Impacts of Contaminated Transboundary Flows).
The San Diego Division of CBP conducts Tijuana River Valley operations from the Imperial Beach
Station, located immediately east of the Naval Outlying Landing Field Imperial Beach. CBP conducts
routine patrols across the span of the border fence, including the canyons and the Tijuana River
where it crosses the border. CBP also monitors and maintains the integrity of the grates in the Goat
Canyon, Smuggler's Gulch, and Stewart's Drain culverts underneath the border fence. Under current
conditions, CBP's ability to safely perform these duties in the canyons is hindered by the frequent
presence of pooled dry-weather transboundary flows (including trash and sediment) around the
grates and in the canyon flow diversion structures, particularly in Goat Canyon.
Public Schools and Districts
One public school, Willow Elementary School, is located within the Tijuana River Valley,
approximately 1 mile northeast of the ITP. Surrounding neighborhoods are serviced by public
school districts including the South Bay Union School District and San Ysidro School District In
addition to public schools, several private schools are located north of the Tijuana River Valley.
Other Public Community Facilities
Other public facilities in the area include libraries, recreation centers, and parks. The closest library
to the Tijuana River Valley is the Imperial Beach Library, approximately 2 miles north of the
TRNERR. Several recreation centers are located in San Ysidro and Imperial Beach. The open space
of the Tijuana River Valley contains several recreational parks under varying jurisdictions (i.e.,
state, local, and federal). These include the Tijuana Slough NWR, Border Field State Park, Tijuana
River Valley Regional Park, the TRNERR, and Friendship Park. See Section 3.9 (Land Use) for
additional information about these parks.
Utilities
The City of San Diego Public Utilities Department operates the Point Loma WWTP and the SBWRP,
the latter of which provides local wastewater treatment services and reclaimed water to the South
Bay area. However, most properties within the Tijuana River Valley are not served by city sewers
and instead rely on septic systems. The ITP treats transboundary wastewater flows from Tijuana,
including flows from the canyon collector system, but does not provide wastewater treatment for
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communities in the U.S. The residents and businesses in the Tijuana River Valley, including USIBWC
(for ITP operations), purchase and receive potable water from the City of San Diego Public Utilities
Department and electricity from SDG&E. See Section 3.1 (Freshwater and Estuarine Resources) for
additional information on drinking water and Section 3.14 (Energy) for additional information on
energy use. Information is limited on communication infrastructure and service providers that
service the Tijuana River Valley.
3.16 Public Health and Safety
In the Tijuana River Valley and neighboring coastal areas, existing sources of public health and
safety concerns include transboundary flows of untreated wastewater and trash from Mexico and
the subsequent contamination concerns. In February 2021, the San Diego County Board of
Supervisors declared pollution in the Tijuana River Valley a public health crisis (City News Service,
2021). Additional topics relevant to discussion of public health and safety include the management
of and exposure to hazardous materials, waste sites, and areas susceptible to hazardous conditions.
Untreated wastewater enters the Pacific Ocean in transboundary flows through the Tijuana River
and discharges via SAB Creek. Once in the ocean, contaminants in the wastewater—including
bacteria (e.g., Enterococcus and E. coli) and norovirus—can pose human health risks to those who
work and recreate along the coastline in southern San Diego County. These affected groups
primarily include beachgoers, surfers, U.S. Navy SEALs training facility personnel (located in
Coronado, California), and CBP personnel. The County of San Diego monitors the ocean water for
FIB and closes beaches if the FIB concentration exceeds the EPA beach action value (an "FIB
exceedance"). As discussed in Section 1.3.2 (Impacts of Contaminated Transboundary Flows), poor
coastal water quality has contributed to frequent beach closures in southern San Diego County. The
beaches at Imperial Beach Pier and Border Field State Park have averaged 66 and 170 closure days
per year since 2003, respectively, with even more frequent closures at Border Field State Park in
recentyears (averaging 262 closure days per year since 2019). Additionally, beach closures and
warning days in southern San Diego County have significantly increased since May 2022, when the
county implemented a new and more sensitive water quality monitoring method for bacteria (Dias,
2022; Elmer, 2022a, 2022b; SCCWRP, 2022). Historical monitoring data collected at nearshore kelp
stations near the Tijuana River mouth show that elevated FIB levels occur more frequently in wet-
weather conditions, typically due to heavy storm activity and river runoff (City of San Diego, 2020a;
City of San Diego Public Utilities, 2016). Studies have shown increased risk of gastrointestinal or
other acute illness in surfers within three days after a rain event (Arnold et al., 2017; Schiff et al.,
2016). However, a recent modeling study by the Scripps Institution of Oceanography indicated that
human health risk during the dry season may be greater than previously understood, due to
transport of norovirus from coastal discharges in Mexico (Feddersen et al., 2021). Exposure to
pathogens from fecal matter while swimming can cause gastrointestinal illness such as vomiting,
diarrhea, stomachache, nausea, and sometimes fever (EPA, 2012). Non-gastrointestinal adverse
health effects can include upper respiratory illness, rash, eye ailments, earache, or infections (EPA,
2012). Residents of the City of Imperial Beach have reported illnesses and ear infections as a result
of exposure to the contaminated ocean water.
Aerosolization of microbes in contaminated coastal water can potentially lead to airborne exposure
to pathogens among beachgoers and residents in coastal areas. In a recent study led by the Scripps
Institution of Oceanography, researchers released 30 gallons of water-soluble and non-toxic dye
into the ocean at Imperial Beach, California and monitored its water and air dispersal to model
aerosolization of pathogens. This dye was detected in the air as far as 668 meters inland and 720
meters downwind from the source. This study indicates that coastal water pollution can be
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aerosolized and carried inland by onshore winds (Pendergraft et al., 2021), although the impacts to
public health were not studied. The Scripps Institution of Oceanography is continuing to perform
air quality monitoring to inform assessment of potential public health impacts of aerosolized
contaminated water (Scripps Institution of Oceanography, 2021).
CBP routinely conducts activities that result in exposure of their agents to polluted water at the
border, such as cleaning and removing debris from culverts, operating gates during high-flow
events, monitoring access points in the canyons, and performing other basic security functions. CBP
agents maintain the in-culvert grates in Goat Canyon, Smuggler's Gulch, and Stewart's Drain,
resulting in exposure to contaminated pools of dry-weather transboundary flows around the grates
and in the canyon flow diversion structures, particularly in Goat Canyon. Exposure to these
conditions has led to epidermal rashes in CBP agents performing their duties. CBP has also reported
agents who have endured stomach issues, and one agent who nearly lost an arm to a flesh-eating
bacteria infection (CBS News, 2020). Additionally, Navy personnel who train in the Pacific Ocean
have reportedly endured gastrointestinal illnesses, and even some more serious cases of infection
such as cellulitis (CBS News, 2020).
Trash in the Tijuana River Valley often includes items such as lumber, tires, plastics, textiles, paper,
bottles, and metal and originates from upstream areas in Mexico. The total weight of ground surface
trash in the valley has been estimated at approximately 5.9 million pounds (2,950 tons) (URS,
2010). See Section 3.13 (Solid and Hazardous Waste) for further details on trash in the valley.
Public health concerns about trash accumulation in the valley include exposure to bacteria, viruses,
and toxic substances from trash such as diapers, medical and household waste, and chemicals;
puncture and laceration injuries resulting in microbial exposure that can cause illness; and ponding
of water in containers and tires, which provides mosquito breeding areas and can increase the risks
of diseases such as encephalitis and the West Nile virus (Tetra Tech, 2009). Vector-borne diseases
have been associated with the accumulation of solid waste in urban areas—particularly garbage
and trash accumulations, which can provide food sources and breeding and burrowing sites for
animal disease vectors such as canines and rodents (Krystosik etal., 2020). Accumulation of solid
waste, such as tires, creates harborage that provides shelter and food for rodents (Quinn et al.,
2019). In California, rats and mice persist in almost all cities, and the presence of these rodents
around human infrastructure may increase human exposure to allergens, infectious organisms, and
parasites that may transmit other diseases (Quinn et al., 2019).
Development in areas susceptible to hazardous conditions (e.g., wildfire risk areas, coastal zones,
landslides, floodplains) can create public health and safety concerns unless managed and planned
carefully. The City of San Diego, in accordance with state law, has designated Very High Fire Hazard
Severity Zones. Building standards in these areas may specifically include measures to reduce the
rate of fire spread, such as through vegetation management. The Tijuana River Valley is located
entirely within a Very High Fire Hazard Severity Zone (City of San Diego, 2009). In addition, some
portions of the valley are characterized as landslide hazard areas, such as those with steep slopes.
The Tijuana River Valley is also located within a coastal zone subject to sea level rise and contains a
regulatory floodway and 100-year floodplains. See Sections 3.1 (Freshwater and Estuarine
Resources), 3.3 (Floodplains), 3.6 (Geological Resources), and 3.12 (Climate) for more information
about development in these areas.
3.17 Transportation
The Tijuana River Valley is a relatively undeveloped region and has limited transportation
infrastructure. There are no public transportation routes (e.g., buses, light rail) or freeways. Several
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rural two-direction, one-lane roads traverse the Tijuana River Valley, most notably Dairy Mart
Road, Hollister Street, and Monument Road. Only two bridges cross the Tijuana River in the U.S. at
Dairy Mart Road and Hollister Road. The Tijuana River Valley region is accessed by Interstate 5,
which extends to the San Ysidro Port of Entry just east of the Tijuana River.
Roads in San Diego County near the U.S.-Mexico border are heavily congested in the vicinity of the
San Ysidro Port of Entry, which is the busiest land port of entry in the Western Hemisphere (GSA,
2021). Lines of vehicles waiting for entry can extend for several miles on local freeways and total as
many as 70,000 vehicles per day. The Port of Entry was recently modernized and expanded to
include additional inspection booths, Interstate 5 highway realignment, and additional pedestrian
infrastructure, with construction completed in 2019 (GSA, 2021). The San Ysidro Port of Entry is
located less than 1,000 feet to the east of where the Tijuana River crosses the border. The
southbound side of Interstate 5 leading up to the Port of Entry is considered one of the top 10
bottleneck areas in Caltrans District 11 during peak a.m. and/or p.m. periods (Caltrans, 2021a). The
ITP parcel is accessed near the intersection of Dairy Mart Road and Monument Road. Asphalt and
gravel roads encircle the perimeter of the complex, and there is a loose grid of paved and unpaved
roads throughout the site, including the lower unpaved portion of Dairy Mart Road. Access to the
ITP facility is controlled.
Authorized vehicles can access Goat Canyon and Smuggler's Gulch from dirt roads by way of
Monument Road. Maintenance roads along the north and south levees, and on top of the north
levee, are used by USIBWC and CBP. CBP also uses Border Road, which runs along the U.S.-Mexico
border from the Pacific Ocean to the south levee.
The managers at the TRNERR have identified the following as primary roads that are important to
maintain for emergency vehicles, community evacuations, border security, and public access: Dairy
Mart Road, Hollister Street, Monument Road, Seacoast Drive, roads on the north and south levees,
access to Imperial Beach Border Patrol Station from Saturn Boulevard, Border Road, the Smuggler's
Gulch access road, and dirt roads crisscrossing the TRNERR.
Traffic volumes in the Tijuana River Valley are low. Table 3-13 summarizes the annual average
daily traffic (AADT) counts at several locations along Dairy Mart Road, Monument Road, and
Interstate 5. The data represent two-way (except for ramp segments which are one-way), 24-hour
volumes. However, during site visits in 2021, traffic congestion during rush hour was occasionally
observed on Dairy Mart Road near the Interstate 5 interchange, including at the three-way
intersection with Servando Avenue.
The stretch of Monument Road and Dairy Mart Road from the entrance to Border Field State Park
all the way to Interstate 5 is designated as a bike route.
Portions of Monument Road are affected by flooding due to transboundary flows through the
border canyons. Flows entering the U.S. from Mexico at Smuggler's Gulch frequently exceed the
capacity of the existing culvert under Monument Road. During these conditions, Monument Road
can become unpassable, greatly limiting vehicular access to areas in the valley west of this point.
As discussed in Section 3.13 (Solid and Hazardous Waste), existing operations at the ITP produce
waste that is trucked to a disposal facility in Punta Bandera, Mexico. This facility is approximately
4.2 miles south of the international border or approximately 10 miles from the ITP by road.
However, logistical difficulties regarding access to hauling services are currently limiting the plant's
ability to effectively remove sludge from the site. Other regional disposal facilities in the U.S. that
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are being considered for wastewater treatment process sludge waste include Otay and Sycamore
Landfills.
Table 3-13. AADT Counts for Selected Roads Within and Near the Tijuana River Valley
Street
Segment
Count
Year of Data a
Dairy Mart Road
San Ysidro Blvd West to Interstate 5 Ramp
18,800
2016
Interstate 5 Ramp to Servando Avenue
12,700
2016
Servando Avenue to Camino De La Plaza
10,000
2016
Monument Road
Hollister Street to Clearwater Way
2,100
2016
Interstate 5
Northbound at Dairy Mart Road
51,000
2020
Northbound at Via San Ysidro
38,000
2020
Interstate 5 (ramp
Northbound on from West San Ysidro
14,100
2017
volume)
Boulevard
Northbound off to West San Ysidro Boulevard
2,541
2021
Southbound on from Dairy Mart Road
2,050
2017
Southbound off to Dairy Mart Road
11,400
2017
Northbound off to State Route 905
2,700
2017
Southbound on from State Route 905
2,200
2017
State Route 905
Eastbound at Interstate 5 junction
29,000
2020
(between
Eastbound San Diego Freeway at 1-5 junction
31,000
2020
Interstates 5 and
Eastbound at Beyer Boulevard
56,000
2020
805)
Eastbound at Picador Boulevard
56,000
2020
Eastbound at Interstate 805 junction
74,000
2020
Westbound at Interstate 805 junction
56,000
2020
Westbound at Picador Boulevard
56,000
2020
Westbound at Beyer Boulevard
50,000
2020
Westbound San Diego Freeway at Interstate 5
junction
11,400
2020
Westbound at Interstate 5 junction
11,000
2020
State Route 905
Eastbound off to Interstate 805 northbound
15,000
2016
(ramp volume)
Westbound on from Interstate 805
southbound
18,700
2019
Interstate 805
Northbound at State Route 905 junction
128,000
2020
(north of State
Northbound at Palm Avenue
150,000
2020
Route 905)
Northbound Auto Parkway Drive/Main Street
154,000
2020
Southbound Auto Parkway Drive/Main Street
150,000
2020
Southbound at Palm Avenue
128,000
2020
Southbound at State Route 905 junction
61,000
2020
Interstate 805
Northbound off to Auto Park/Main Street
8,300
2020
(ramp volume)
Southbound on from Auto Park/Main Street
11,200
2014
Main Street
Between ramp Interstate 805 northbound and
Main Court
35,700
2016
Between Oleander Avenue and Brandywine
Avenue
22,400
2016
Maxwell Road
Between Main Street and landfill
2,800
2016
Source: (Caltrans, 2020a, 2020b; SANDAG, 2022a)
a - Where AADT counts were available from multiple sources, the most recent data points were used for this table.
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3.18 Noise
Noise is unwanted or disturbing sound that can interfere with normal activities or disrupt quality of
life. Noise sources (e.g., highways, airports) exist within or near the Tijuana River Valley, and new
noise sources can be introduced during construction and operation of new facilities. Excessive
noise refers to sound levels that would endanger public safety or cause discomfort or annoyance to
a person of normal sensitivity. Impulsive noise refers to a single noise event that causes a high peak
noise level lasting less than one second (e.g., fireworks or certain construction activities such as pile
driving). Excessive noise or impulsive noise can affect nearby noise-sensitive receptors such as
schools, neighborhoods, and habitats.
Noise levels are typically measured as decibels (dB) or A-weighted decibels (dBA) and are often
regulated under state or local ordinances. Noise decreases with distance from the noise source at a
rate between approximately 3 dBA to 6 dBA per doubling of distance due to cylindrical spreading of
energy from line sources (e.g., roadways) or spherical spreading of energy from point sources over
an increasing area (Caltrans, 2013). Table 3-14 compares the perception of noise levels associated
with common noise sources.
Local ordinances regulate noise by establishing acceptable noise thresholds and potentially
requiring permits and noise mitigation for construction activities and noise-producing equipment,
as described in Section 6.1.13 (Noise). Table 3-15 compares the county and city sound level
limitations.
Table 3-14. Perception of Typical Noise Levels
Noise Level (dB)
Example Common Noise Source
Subjective Evaluation
140
Fireworks, gun shot
Painful and dangerous
130
Ambulance siren
120
Jet plane taking off
Uncomfortable; dangerous after 30
seconds of exposure
110
Concert, sporting event
Very loud; dangerous after 30
minutes of exposure
100
Music player at full volume, snowmobile
90
Blender, lawnmower, power tools
80
Alarm clock
Loud
70
Vacuum, vehicle traffic
60
Normal speech, dishwasher
Moderate
50
Rainfall
40
Library
Soft
30
Whisper
20
Leaves rustling
Faint
Source: (American Academy of Audiology, 2010).
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Table 3-15. San Diego County and San Diego City Sound Level Limits
Land Use
Time of Day
County One-Hour Average
Sound Level (dB)a
City One-Hour Average
Sound Level (dB)b
Single family residential
7 a.m. to 7 p.m.
50
50
7 p.m. to 10 p.m.
50
45
10 p.m. to 7 a.m.
45
40
Multi-family residential
7 a.m. to 7 p.m.
55
55
7 p.m. to 10 p.m.
55
50
10 p.m. to 7 a.m.
50
45
All other residential
7 a.m. to 7 p.m.
60
60
7 p.m. to 10 p.m.
60
55
10 p.m. to 7 a.m.
55
50
Commercial
7 a.m. to 7 p.m.
55-70
65
7 p.m. to 10 p.m.
55-70
60
10 p.m. to 7 a.m.
50-65
60
Industrial or agricultural (including
operational activities)
Any time
70-75
75
a - San Diego County Code § 36.404.
b - San Diego Municipal Code § 59.5.0401.
In San Diego County, transportation is the most significant source of noise, including noise from
motor vehicle traffic, as well as aircrafts and railroads in certain portions of the county (County of
San Diego, 2011). Interstate 5 is an eight-lane highway just northeast of the Tijuana River Valley
and connects the metropolitan areas of San Diego and Tijuana. In Mexico, Mexico ID and Via
Internacional are highways that parallel portions of the U.S.-Mexico border. Mexico ID is a tolled
six-lane highway, and Via Internacional is a four-lane freeway in Tijuana. These highways generate
typical transportation-related noise on the edges of the Tijuana River Valley.
The Tijuana River Valley is predominantly open space consisting of parks with trails for residents
and visitors, which do not generate substantial background noise. Major sources of noise in the
Tijuana River Valley and neighboring areas include military and commercial airports. The Naval
Outlying Landing Field Imperial Beach, located directly north of the TRNERR, handles overflow
helicopter squadrons and conducts helicopter training in addition to serving as an airport (City of
Imperial Beach, 2019). Brown Field Municipal Airport is located approximately four miles
northeast of the project area in the Otay Mesa community and is used as a public airport (City of
San Diego, 2021a). Tijuana International Airport is south of Brown Field Municipal Airport, located
just across the U.S.-Mexico border. The Tijuana International Airport is a public airport, handling up
to 10 million passengers a year (Grupo Aeroportuario del Pacifico, 2015). Other minor noise
sources within the Tijuana River Valley and near the project site include traffic along Monument
Road and Dairy Mart Road (including heavy vehicles such as dump trucks), CBP use of off-road
vehicles, and wastewater treatment operations at the ITP and SBWRP, including use of emergency
generators and pump stations. The ITP and SBWRP are not known to be substantial existing noise
sources in the area since publicly owned treatment works are typically designed to operate
adjacent to residential areas and are well insulated. Based on a recent noise survey, exterior
locations at the ITP registering the highest noise levels were at the emergency generators (106-110
dB, when generator is running) and above the secondary reactors (115-128 dB). These locations
are each at least 300 feet from the nearest ITP property boundary.
Noise-sensitive receptors in the vicinity of the Tijuana River Valley include schools, residential
areas, recreational parks, and wildlife habitats. Table 3-16 and Figure 3-21 identify noise-sensitive
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receptors located within 0.5 miles from U.S.-side project components. In addition, the Tijuana River
Valley provides valuable habitat for protected avian species such as the least Bell's vireo and
western snowy plover, which can be sensitive to noise as discussed in Section 3.4.2 (Wildlife and
Inland Fish Resources).
Airborne sound with a very low frequency and sufficient amplitude can sometimes be felt before it
is heard, and may therefore be confused with ground-borne vibration (Caltrans, 2013). Ground-
borne vibration occurs when energy excites the adjacent ground, causing vibration waves to
oscillate and spread rapidly through the ground. Ground-borne vibration can be caused by heavy
vehicle traffic, trains, and construction activities. Vibrations can propagate through the earth to the
foundations of buildings, and, in extreme cases, can cause structural damage.
Table 3-16. Noise-Sensitive Receptors in the Vicinity of Project Areas
Noise-Sensitive Receptor
Receptor Type
Distances to Example Nearby Project Elements
Tijuana River Valley Regional
Park
Recreational
¦ 0 feet (from Project B trenching or trenchless entry/exit
point)
¦ 450 feet (from Project A potential staging activities at ITP)
Least Bell's vireo critical habitat
Wildlife
¦ 0 feet (from common construction vehicle route)
¦ 400 feet (from Option B1 trenching)
¦ 400 feet (from Project A potential staging activities at ITP
Potential least Bell's vireo
habitat
Wildlife
¦ 0 feet (from Project B trenching or trenchless entry/exit
point)
Potential coastal California
gnatcatcher habitat
Wildlife
¦ 0 feet (from Project B trenching or trenchless entry/exit
point)
Residences along Monument
Road
Residential
¦ 20 feet (from common construction vehicle route and
Option B1 trenching)
Residences along Dairy Mart
Road, San Ysidro Blvd W, and
near Interstate 5 interchange
Residential
¦ 20 feet (from common construction vehicle route)
Residences in Tijuana near the
U.S.-Mexico border
Residential
¦ 0 feet (from Project C potential sewer repair locations)
¦ 90 feet (from Project J potential trash processing area)
¦ 170 feet (from Project D trenching)
¦ 350 feet (from Project A construction at ITP)
¦ 150 feet (from Project F and J areas under consideration)
Coral Gate neighborhood
Residential
¦ 230 feet (from Project F and J areas under consideration)
Willow Elementary School
Educational
¦ 0.5 miles (from Project F and J areas under consideration)
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Noise-sensitive receptors
Least Bell's vireo critical habitat
Tijuana River Valley Regional Park
¦ SAN iYSIDRO,
Residences along
Dairy Mart Road,
San Ysidro Blvd W,
and near Interstate 5
interchange
mmWtM
Willow Elementary
School
Coral Gate
eighborhood
Residences along
Monument Road
Plaza.
!un^dT^ates-
S^XICS®
Smuggler's Gulch
(potential habitat for
least Bell's vireo and
coastal California
gnatcatcher)
jjMlD.O W NTOWN~
Residences in Tijuana near *.•
the U.S.-Mexico border '
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Figure 3-21. General Locations of Noise-Sensitive Receptors in the Vicinity of Project Areas
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3.19 Socioeconomics
This section describes the existing social and economic resources—including population,
employment, income, and housing—in San Diego County, the City of San Diego (including the
district of San Ysidro), the City of Imperial Beach, and communities in Tijuana near the U.S.-Mexico
border.
See Section 3.20 (Environmental Justice) and Appendix I (Supplemental Data for Environmental
Justice Analysis) for additional demographic information regarding communities in the vicinity of
the Proposed Action, including analyses at the census tract and census block group level.
Population
Table 3-17 summarizes population data for the U.S. jurisdictions in the vicinity of the Proposed
Action. The population of San Diego County is estimated to be over 3.3 million as of April 2020 and
is expected to grow to over 4 million by mid-century, an increase of just over 20 percent. The City of
Imperial Beach and the district of San Ysidro are roughly equal in population (roughly 28,000 and
26,000, respectively). Population growth forecasts are based on a combination of economic and
demographic projections, existing land use plans and policies, and potential land use plan changes.
San Ysidro's population is particularly young, with roughly 30 percent of the population 18 years of
age and under. San Ysidro is expected to undergo increased development intensity and significant
population growth, including the addition of housing units near transit stations (City of San Diego,
2017; SANDAG, 2021d). The population of San Ysidro is expected to grow significantly, with a
projected growth of 37 percent between 2020 and 2035. The population of Tijuana is currently
estimated to be 1.6 million and is growing at a rate of approximately 2.5 percent per year. However,
this may be an underrepresentation of population due to the high numbers of unregulated tenants
in Tijuana who do not hold legal land titles, who are not likely listed in official population statistics.
Table 3-17. Current and Projected Population of U.S. Communities in Vicinity of Proposed Action
Jurisdiction
2020
Population
20
Population
35
% Change from
2020
20
Population
50
% Change from
2020
County of San Diego
3,343,349
3,853,698
+15%
4,068,759
+22%
—City of San Diego
1,430,483
1,665,609
+16%
1,777,936
+24%
District of San Ysidro
26,082
35,797
+37%
39,367
+51%
—City of Imperial Beach
28,055
30,369
+8%
31,691
+13%
Source: (SANDAG, 2013a, 2013b, 2013c, 2013d, 2021a, 2021b, 2021c, 2021d).
Table 3-18 summarizes the racial demographics for the U.S. jurisdictions in the vicinity of the
Proposed Action. San Diego County, the City of San Diego, the district of San Ysidro, and the City of
Imperial Beach are all majority-minority jurisdictions, with 54 percent, 56 percent, 88 percent, and
68 percent of the population represented by non-white demographic groups, respectively. The
most common minority group is Hispanic, particularly in San Ysidro and the City of Imperial Beach,
where they represent a majority of the population (83 percent and 51 percent, respectively). See
Figure 3-22, Section 3.20 (Environmental Justice), and Appendix I (Supplemental Data for
Environmental Justice Analysis) for additional information. In Mexico, there are 68 indigenous
communities and one Afro-Mexican community. There is a relatively large indigenous population in
the Baja California border region (which includes Tijuana) compared to other Mexican states that
share a border with the U.S. Additionally, there is one national coordination center for indigenous
peoples (Centro Coordinadores de Pueblos Indigenas) located in the border region of Baja California.
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Table 3-18. Racial Demographics of U.S. Communities in Vicinity of Proposed Action, 2020
American
Indian
Asian and
Jurisdiction
Hispanic
White
Black
Pacific
Islander
All Other
County of San Diego
1,142,875
1,536,268
159,320
15,153
369,059
120,674
(34%)
(46%)
(5%)
(<1%)
(11%)
(4%)
—City of San Diego
441,621
630,962
83,222
5,211
213,858
55,609
(31%)
(44%)
(6%)
(<1%)
(15%)
(4%)
District of San Ysidro
21,532
3,250
341
62
705
192
(83%)
(12%)
(1%)
(<1%)
(3%)
(1%)
—City of Imperial Beach
14,432
8,923
1,240
155
2,052
1,253
(51%)
(32%)
(4%)
(1%)
(7%)
(4%)
Source: (SANDAG, 2021a, 2021b, 2021c, 2021d).
Data on English-speaking ability and limited English-speaking households, or households
experiencing "linguistic isolation," are collected in the American Community Survey (ACS) and are
available for the study region. A linguistically isolated household is described as "a household in
which all members age 14 years and over speak a non-English language and also speak English less
than Very well' (have difficulty with English)" (EPA, 2022f). In the City of San Diego, 40 percent of
the population five years of age and over speak a language other than English in their households
(either partially or entirely), and 15 percent of the population five years of age and over speak
English "less than very well." The most common language spoken in the household other than
English is Spanish, representing 23 percent of the population 5 years of age and over, followed by
Asian and Pacific Islander languages at 12 percent (Census Bureau, 2019b). The City of Imperial
Beach has similar language statistics: 45 percent of the population five years of age and over speak
a language other than English in their households, and 14 percent of the population five years of
age and over speak English "less than very well." The most common language spoken in the
household other than English is Spanish, representing 39 percent of the population five years of age
and over, followed by Asian and Pacific Islander languages at 5 percent (Census Bureau, 2019f).
Language statistics specific to the district of San Ysidro and the Coral Gate neighborhood are not
readily available; however, 90 percent of residents in the census tract containing Coral Gate and
portions of San Ysidro speak Spanish at home (Census Bureau, 2019c). Additionally, in the census
block group encompassing the ITP parcel (Block Group 060730100091), 47 percent of the
population speaks English "less than very well," and 100 percent of linguistically isolated
households speak Spanish (EPA, 2022b). Many communities throughout the South Bay area are
characterized as "linguistically isolated" as documented in Appendix I (Supplemental Data for
Environmental Justice Analysis).
Employment and Income
The major employment sectors in the San Diego region are military, tourism, international trade,
and manufacturing (City of San Diego, 2021b). With many military installments in the county, the
U.S. Navy is one of the largest employers in the region (City of San Diego, 2019).
Table 3-19 summarizes the total current and projected employment statistics across all sectors in
the U.S. jurisdictions in the vicinity of the Proposed Action. Each jurisdiction is projected to have an
approximately 30 percent increase in available jobs from 2012 to 2050.
The unemployment rate in the San Diego region has been negatively impacted by COVID-19
closures and job losses. As of August 2021, the unemployment rate in the San Diego region was 6.6
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percent, twice as high as the pre-pandemic rate of 3.2 percent, but less than the 15.9 percent peak
in April 2020 (SANDAG, 2021e). However, in February 2022, unemployment reached a post-
pandemic low rate of 4.0 percent, marking a 50 percent decrease from February 2021 (SANDAG,
2022b). While unemployment rates have decreased since April 2020, the current unemployment
rate in the region continues to be slightly higher than recent historical rates due to COVID-19. See
Section 3.20 (Environmental Justice) and Appendix I (Supplemental Data for Environmental Justice
Analysis) for additional unemployment data.
Table 3-19. Current and Projected Employment of U.S. Communities in Vicinity of Proposed Action
Jurisdiction
2012
2050
Percentage Change
2012-2050
County of San Diego
1,450,913
1,911,405
+32%
—City of San Diego
780,252
1,008,793
+29%
District of San Ysidro
7,322
9,800
+34%
—City of Imperial Beach
3,665
4,857
+33%
Source: (SANDAG, 2013a, 2013b, 2013c, 2013d).
Beach closures due to poor water quality are likely to have adversely affected employment and
income in the City of Imperial Beach and adjacent coastal communities; however, specific data
regarding the degree of these economic impacts are not readily available.
Table 3-20 summarizes the median household income of U.S. jurisdictions in the vicinity of the
Proposed Action. A projected median household income is not available because the San Diego
Association of Governments' (SANDAG's) income forecast is under review. Of the adjacent
communities, the City of San Diego has the highest median household income, followed closely by
San Diego County. The City of Imperial Beach median household income is approximately 30
percent lower than that of San Diego County as a whole, and San Ysidro has the lowest median
household income of the nearby jurisdictions.
In the City of San Diego, 8.3 percent of families (representing 12.8 percent of people) have
household incomes that fall below poverty level. In the City of Imperial Beach, 13.8 percent of
families (representing 18.9 percent of people) have household incomes that fall below poverty level
(Census Bureau, 2019a, 2019e). In the Coral Gate neighborhood, 6.1 percent of families have
household incomes that fall below poverty level (Census Bureau, 2019d). Many communities
throughout the South Bay area—not including the Coral Gate neighborhood—have relatively high
prevalence of low-income households, as shown in Figure 3-23 and documented in Section 3.20
(Environmental Justice) and Appendix I (Supplemental Data for Environmental Justice Analysis).
Table 3-20. Median Household Income of U.S. Communities in Vicinity of Proposed Action
Jurisdiction
2018$
County of San Diego
$82,538
—City of San Diego
$83,543
District of San Ysidro
$47,972
—City of Imperial Beach
$57,545
Source: (SANDAG, 2019a, 2019b, 2019c, 2019d).
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Housing
Table 3-21 summarizes the current housing inventories in U.S. jurisdictions in the vicinity of the
Proposed Action. The total number of housing units in San Diego County is just over 1.2 million, 60
percent of which are single-family units. Multi-family units account for 37 percent, with the
remainder consisting of mobile homes and other types. By 2050, total housing units in San Diego
County, the City of San Diego, the district of San Ysidro, and the City of Imperial Beach are expected
to increase by 23, 28, 31, and 15 percent from 2020 levels, respectively, based on data from
SANDAG (2013a, 2013b, 2013c, 2013d, 2021a, 2021b, 2021c, 2021d).
In the southern urban areas of San Diego County, a high proportion of housing units are occupied
and overcrowded (i.e., with more than one occupant per room). Overcrowded housing exists in all
census tracts in the Tijuana River Valley and is especially prevalent in areas along the Interstate 5
corridor through Chula Vista and National City (Public Health Alliance, 2022). In the census tract
containing the ITP parcel (6073010009) which has a population of 6,978, only 29.4 percent of
people own their own home (17th percentile in the state) compared to a 53.3 percent
homeownership rate in the county. This census tract scored well in housing habitability, meaning
households have basic kitchen facilities and plumbing (Public Health Alliance, 2022). The
significant majority of housing units in this tract are fully occupied (only 20 out of 1,722 were
unoccupied, according to 2015-2019 ACS data) (EPA, 2022c).
The Coral Gate neighborhood is made up of 477 housing units, 98 percent of which are single-family
detached homes (Census Bureau, 2019d). The remainder are three- or four-unit apartments.
Ninety-four percent of households are owner occupied, and 6 percent are renter occupied. The
median real estate property value of homes in the neighborhood is $470,600. The median age of the
real estate in the neighborhood is 23 years (Census Bureau, 2019d).
Table 3-21. Total Current Housing Units of U.S. Communities in Vicinity of Proposed Action, 2020
Jurisdiction
Single-Family,
Detached
Single-Family,
Attached
Multi-Family
Mobile Home
and Other
Total Housing
Units
County of San Diego
613,492
114,398
446,029
42,120
1,216,039
—City of San Diego
237,494
49,240
253,453
4,962
545,149
District of San Ysidro
2,234
430
4,673
508
7,845
—City of Imperial Beach
4,406
1,408
4,006
185
10,005
Source: (SANDAG, 2021a, 2021b, 2021c, 2021d).
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060730101032060730101101
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Figure 3-23. Low-Income Percent of Population for Census Block Groups in San Diego County, Based on EJScreen 2.0 Data
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3.20 Environmental Justice
EO 12898, Federal Actions to Address Environmental Justice in Minority Populations and Low-Income
Populations (59 FR 7629), directs federal agencies to make environmental justice (EJ) part of their
missions by "identifying and addressing, as appropriate, disproportionately high and adverse
human health or environmental effects of their programs, policies, and activities on minority
populations and low-income populations..." CEQ has oversight of the federal government's
compliance with EO 12898 and NEPA, and developed Environmental Justice Guidance Under the
National Environmental Policy Act in 1997 to help federal agencies identify and address
environmental justice concerns when conducting NEPA assessments (CEQ, 1997b). When
determining whether effects stemming from proposed actions are disproportionately high and
adverse, CEQ's guidance directs agencies to consider each of the following three factors to the
extent practicable (CEQ, 1997b):
• Whether there is, or will be, an effect on the natural or physical environment that
significantly (as defined by NEPA) and adversely affects a minority or low-income
population or Indian tribe. Such effects may include ecological, cultural, human health,
economic, or social impacts that are linked to impacts on the natural or physical
environment
• Whether existing environmental effects are significant (as defined by NEPA) and currently
or could in the future have an adverse impact on minority or low-income populations or
Indian tribes. Such effects may include any environmental effects that would appreciably
exceed, or are likely to appreciably exceed, those on the general population or other
appropriate comparison groups.
• Whether environmental effects occur, or would occur, in a minority or low-income
population or Indian tribe affected by cumulative or multiple adverse exposures from
environmental hazards.
When incorporating environmental justice into the NEPA process, EPA also analyzed impacts and
determined significance in accordance with Final Guidance for Incorporating Environmental Justice
Concerns in EPA's NEPA Compliance Analyses (EPA, 1998).
Beyond CEQ and EPA guidance, more recent efforts under the Biden administration have placed a
renewed focus on environmental justice considerations. The recent EO 13985, Advancing Racial
Equity and Support for Underserved Communities Through the Federal Government (86 FR 7009),
directs federal agencies to assess whether, and to what extent, underserved communities face
systemic barriers in accessing opportunities and benefits available pursuant to the agency's policies
and programs. EO 13985 also requires federal agencies to develop a plan for addressing barriers.
EPA's E.0.13985 Equity Action Plan identifies six priority actions that form the foundation for
achieving equity, environmental justice, and civil rights (EPA, 2022e).
Recent federal mandates related to climate change impacts also provide guidance regarding
environmental and climate justice considerations. EO 14008, Tackling the Climate Crisis at Home
and Abroad (86 FR 7619), directs agencies to "make achieving environmental justice part of their
missions by developing programs, policies, and activities to address the disproportionately high
and adverse human health, environmental, climate-related and other cumulative impacts on
disadvantaged communities (DACs), as well as the accompanying economic challenges of such
impacts." EO 14008 also established the White House Environmental Justice Advisory Council
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within EPA to advise on how to increase the federal government's efforts to address environmental
injustice.
EPA is also guided by its own definition of environmental justice, which reflects federal priorities
and guidance. EPA defines environmental justice as "the fair treatment and meaningful involvement
of all people regardless of race, color, national origin, or income with respect to the development,
implementation and enforcement of environmental laws, regulations and policies" (EPA, 2021b).
EPA has the goal of ensuring environmental justice for all communities across the U.S.
Additionally, EPA and USIBWC reviewed Promising Practices for EJ Methodologies in NEPA Reviews,
which provides methods for incorporating robust environmental justice considerations into NEPA
processes (IWG on Environmental Justice & NEPA Committee, 2016). This report does not establish
new requirements for NEPA analysis and is intended to provide flexibility for agencies as they
examine environmental justice during NEPA reviews.
As described in the following subsections, EPA and USIBWC evaluated whether environmental
inequities exist in communities in the vicinity of construction and operational activities under the
Proposed Action. Section 4.20 (Environmental Justice) discusses the potential impacts of the
Proposed Action, including the potential for disproportionately high and adverse effects on
minority and/or low-income populations, such as potential exacerbation of existing social,
economic, health, or environmental burdens. A more detailed description of the environmental
justice review and analyses for the Proposed Action is described in Appendix I (Supplemental Data
for Environmental Justice Analysis).
Geographic Scope of Analysis
EPA and USIBWC defined the geographic scope of the environmental justice analysis in the U.S. (EJ
Study Area) for the Proposed Action as a polygon that includes all census block groups and tracts
falling within one of two areas (EJ Study Area 1 or EJ Study Area 2). The geographic extents of EJ
Study Areas 1 and 2 are defined as follows and illustrated in Figure 3-24:
• EJ Study Area 1 includes all census block groups located (entirely or partially) within 0.5
miles of the edge of a polygon encompassing the locations of potential construction
activities under the Proposed Action, excluding on-road vehicle use.39 Communities in this
area are more likely to be affected by short-term construction and long-term O&M of new
infrastructure under the Proposed Action. EJ Study Area 1 covers approximately 6.36
square miles, encompassing five block groups and two census tracts.
39 The communities located east of Interstate 5 along the U.S.-Mexico border (Block Group 060730100151;
Tract 6073010015) was excluded from EJ Study Area 1. This community is, at its closest, approximately 0.3
miles from the easternmost U.S. project element under the Proposed Action—specifically, the areas under
consideration for the U.S.-side river diversion (Project F; see Figure 2-13). This community was excluded
because 1) only a very small portion of the areas under consideration for the U.S.-side river diversion is
located within 0.5 miles of this community; 2) the intervening area includes dense residential and
commercial development, Interstate 5, and the San Ysidro Port of Entry, which would likely obscure the
effects of any activities associated with the river diversion; and 3) this community area is more than 10 miles
wide and encompasses areas with environmental and social conditions that could substantially differ from
those of the communities close to the Proposed Action.
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• EJ Study Area 2 includes all additional block groups adjacent to the potential truck hauling
route to and from Otay Landfill.40 Communities in this area would potentially be affected by
increased vehicle use along highways and local roads during short-term construction and
long-term O&M of new infrastructure under the Proposed Action. EJ Study Area 2 covers
approximately 30 square miles, including 20 block groups and 13 census tracts.
Coastal communities were excluded from the geographic scope of analysis because the Proposed
Action would be expected to result in significant long-term environmental benefits for coastal
communities, with no adverse construction-related impacts, due to significantly reduced marine
discharges of untreated wastewater. Additionally, a rapid review of demographic and
environmental burden indicators from the available screening tools (discussed below) indicates
that coastal communities in southern San Diego County are generally exposed to fewer and less
intense existing social and environmental burdens than the communities closer to the location of
the Proposed Action.
EPA and USIBWC selected San Diego County as the comparison population—i.e., for each indicator,
this analysis considers whether conditions within the EJ Study Area are higher or lower compared
to the county as a whole. San Diego County was used as a reference point to ensure communities
are adequately examined in comparison to local conditions, rather than using the state as a
reference point which could over- or underestimate the context of local burdens. Using the county
as the reference point also enables comparison between the areas in the county that will accrue
benefits and those that are likely to experience negative impacts. All statistics reported as
percentiles in this section are relative to San Diego County as a whole.
EPA and USIBWC also considered reasonably foreseeable transboundary impacts to communities in
Tijuana along the U.S.-Mexico border that are in the vicinity of potential U.S.-side construction and
operation activities. As described in Section 1.5 (Purpose and Scope of the Programmatic EIS), this
PEIS does not evaluate potential impacts to communities in Mexico that would result from actions
in Mexico. Mexico authorities would be responsible for preparing environmental impact analyses
for actions in Mexico pursuant to Mexican laws and authorities as discussed in Section 6.2 (Mexican
Regulations and Permits).
40 The route to Otay Landfill was chosen, rather than the route to Sycamore Landfill, because Otay Landfill is
much closer and therefore a more likely destination for construction debris and other solids waste. Analyzing
block groups adjacent to the route to Otay Landfill ensures impacts to the local community are appropriately
considered, rather than having an overly broad analysis that examines all communities— including several
non-burdened communities—between the Proposed Action and Sycamore Landfill. For example, the census
block group that includes Sycamore Landfill is 42 percent minority and 11 percent low income, whereas the
census block group that includes Otay Landfill is 85 percent minority and 14 percent low income.
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Data Sources
EPA's Environmental Justice Screening and Mapping Tool (EJScreen 2.0)41 and CalEPA's
CalEnviroScreen 4.042 tools are available to assist the public, planners, and decision makers with
identifying U.S. communities that are disproportionately affected or burdened by environmental,
social, public health, and demographic indicators.
• EJScreen is EPA's web-based application that provides EPA and the public with a nationally
consistent environmental justice screening and mapping dataset and approach for
combining environmental and demographic indicators into Environmental Justice Indexes
(EJ Indexes). EJScreen combines environmental, demographic, and geographic data to
highlight areas where vulnerable populations (as determined based on a series of
demographic indicators) may be disproportionately impacted by pollution and other
environmental stressors. EJScreen assesses potential disproportionate environmental
burdens on and harms to vulnerable populations. It provides a broad and flexible platform
for screening and visualization of potential environmental justice issues at a fine
community scale (census block group).
• CalEnviroScreen 4.0 is a California-specific screening tool based on publicly available data
that is used to identify communities disproportionately burdened by multiple pollution
sources or that exhibit population characteristics that make them more sensitive to
pollution. CalEnviroScreen 4.0 provides data at the scale of census tracts. While some
indicators are similar to those used in EJScreen, CalEnviroScreen 4.0 includes some
California-specific indicators and also enables users to make comparisons between regions
in the state.
EPA and USIBWC used EJScreen 2.0 and CalEnviroScreen 4.0 as primary screening tools to assess
social, economic, environmental, and demographic data for block groups and census tracts in the
geographic scope of analysis. EPA and USIBWC also reviewed additional data sources and reports to
supplement the screening-level analysis:
• The Public Health Alliance of Southern California's Healthy Places Index 3.0 (HPI)43
evaluates socioeconomic and environmental indicators that may affect human health and
life expectancy. Based on these indicators, an HPI score is generated that indicates the
overall community health conditions compared to other communities in California (Public
Health Alliance, 2022). EPA and USIBWC examined the HPI scores and certain indicators for
census tracts located within the geographic scope of analysis. EPA and USIBWC did not
examine indicators provided through HPI 3.0, for which related data is available through
EJScreen 2.0 or CalEnviroScreen 4.0.
• The Good Neighbor Environmental Board's 17th Report (Climate Change and Resilient
Communities Along the U.S.-Mexico Border: The Role of the Federal Agencies)44 was also
41 See https://ejscreen.epa.gov/mapper/.
42 See https://oehha.ca.gov/calenviroscreen/report/calenviroscreen-40.
43 See https://map.healthyplacesindex.org/?redirect=false.
44 See https://19january2017snapshot.epa.gov/sites/production/files/2016-
12/documents/17th_gneb_report_publication_12 0516_final_508.pdf.
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reviewed to help characterize vulnerable populations near the U.S.-Mexico border, water
issues, air pollution and traffic, energy resources, public health, and existing climate change
impacts on the natural and human environment (Good Neighbor Environmental Board,
2016).
• The SDAPCD's AB 617: Community Air Protection Program Submittal for San Diego
International Border Community [Community Air Monitoring and Emission Reduction Plan)45
was presented to CARB in 2019 and identifies and provides socioeconomic and
environmental information on DACs in San Diego County (SDAPCD, 2019a).
• OEHHA identified DACs pursuantto SB 5 3 5.46 DACs are those census tracts thatreceive the
highest 25 percent of overall scores in CalEnviroScreen 4.0 (in addition to census tracts
identified in a previous 2017 designation as disadvantaged, regardless of their scores in
CalEnviroScreen 4.047); census tracts that receive the highest 5 percent of CalEnviroScreen
4.0 cumulative pollution burden scores where no overall CalEnviroScreen 4.0 score is
available; and lands under the control of federally recognized tribes (OEHHA, 2022). DACs
receive investments of proceeds from the California cap-and-trade program as directed by
SB 535 and AB 1550, which sets minimum funding levels to DACs.
Potentially Affected Communities in the U.S.
All population statistics reported as percentiles in this section are relative to San Diego County as a
whole (i.e., for each indicator and community, the percentiles represent the degree of burden
relative to that of all communities in the county for that particular indicator).48 See Appendix I
(Supplemental Data for Environmental Justice Analysis) for additional information on the
methodology used by EPA and USIBWC to calculate and evaluate county percentiles.
Both minority (people of color) and, to a lesser extent, low-income populations are prevalent
throughout the EJ Study Area. Minority and low-income population statistics and figures by
community within the EJ Study Area are provided in Table 3-22 and in Figure 3-25 through Figure
3-33. All communities within the EJ Study Area are above the 80th percentile for minority
populations, with several having extremely high values above the 90th percentile. In particular, 14
block groups and seven census tracts are in or above the 95th percentile—including four block
groups and one census tract in the 99th percentile and one census tract in the 100th percentile—for
minority populations, all of which are located within approximately 0.65 miles of the Proposed
Action, with one encompassing the ITP parcel and one overlapping the boundaries of the area
45 See https://www.sdapcd.org/content/dam/sdapcd/documents/capp/San-Diego-International-Border-
Community-Monitoring-CERP-Year-2-Submittal-092619.pdf.
46 See https://oehha.ca.gov/calenviroscreen/sb535.
47 CalEPA recently released CalEnviroScreen 4.0 and revised their approach to identifying SB 535
communities as of May 2022.
48 EPA and USIBWC evaluated demographic and environmental indicators individually rather than using the
EJ Indexes pre-calculated by EJScreen 2.0, which combine single environmental indicator values with the
demographic index for the block group in order to allow for comparisons of potential exposure and
susceptibility to pollution across all block groups in the U.S.
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under consideration for the U.S.-side river diversion. Block groups in the 90th percentile for
minority populations are located throughout the EJ Study Area.
Several communities within the EJ Study Area are above the 65th percentile for low-income
populations, with some having extremely high values above the 90th percentile. In particular, two
block groups are in the 99th percentile for low-income populations, one of which encompasses the
ITP parcel and is located adjacent to the U.S.-Mexico border, while the other is located adjacent to
California State Route 905. Communities that have low percentiles for low-income populations are
typically—with some exceptions—those that are large in geographic size and thus include
populations far from the areas that would potentially be affected by the Proposed Action. One
exception is the block group that encompasses the Coral Gate neighborhood, which is below the
20th percentile for low-income populations.
EPA and USIBWC assessed whether communities in the EJ Study Area experience disproportionate
environmental burdens. Based on a review of available data obtained through the websites for the
EJScreen and CalEnviroScreen tools, EPA and USIBWC determined that many communities in the EJ
Study Area are currently overburdened49 by one or more environmental indicators. Many
communities in the EJ Study Area experience extremely high burdens (i.e., above the 90th
percentile, for purposes of this analysis) for one or more of the following indicators: lifetime cancer
risks from inhalation of air toxics (all 25 block groups), PM2.5 levels (all 15 census tracts),50 toxic air
chemical releases (all 15 census tracts), less than high school education (11 block groups and five
census tracts), linguistic isolation (11 block groups and five census tracts), unemployment (nine
block groups and seven census tracts), wastewater discharges (11 block groups), solid waste
facilities (six census tracts), traffic impacts (five census tracts), populations of youth (five block
groups), impaired water bodies (four block groups), traffic proximity (four block groups), risks for
cardiovascular disease (four census tracts), diesel PM levels (three census tracts),50 and risks for
asthma (three census tracts).
• Communities experiencing certain extremely high social and health burdens (i.e., low
education levels, linguistic isolation, risks for asthma and cardiovascular disease) tend to be
located within or adjacent to the portion of San Ysidro bordered by Interstates 5/805 and
California State Route 905.
49 Overburdened communities are considered minority, low-income, tribal, or indigenous populations or
geographic locations in the U.S. that potentially experience disproportionate environmental harms and risks.
This disproportionality can be as a result of greater vulnerability to environmental hazards, lack of
opportunity for public participation, or other factors. Increased vulnerability may be attributable to an
accumulation of negative or lack of positive environmental, health, economic, or social conditions within
these populations or places. The term describes situations where multiple factors, including both
environmental and socio-economic stressors, may act cumulatively to affect health and the environment and
contribute to persistent environmental health disparities (EPA, 2016b).
50 EJScreen and CalEnviroScreen present sharply contrasting percentiles for both PM2.5 values and Diesel PM
values. For example, EJScreen indicates that all PM2.5 values for the EJ Study Area are below the 25th
percentile while CalEnviroScreen indicates PM2.5 values in the EJ Study Area are all above the 95th percentile.
Similarly with Diesel PM, EJScreen and CalEnviroScreen report values in the EJ Study Area are below 70th
percentile and up to the 94th percentile, respectively. The updates made in CalEnviroScreen 4.0 (released
October 2021) incorporated several improvements to the PM2.5 and Diesel PM indicators resulting in changes
to the data along the border (i.e., the Diesel PM indicator now reflects emissions from sources in Mexico).
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• Communities experiencing certain extremely high water quality-related burdens (i.e.,
wastewater discharges, impaired water bodies) tend to be located near the U.S.-Mexico
border and in the Tijuana River Valley.
• Communities experiencing extremely high burdens due to Diesel PM tend to be located
immediately west of Interstate 805.
• Communities experiencing extremely high burdens associated with traffic tend to be
located in census tracts along the U.S.-Mexico border and near the San Ysidro Port of Entry
(per CalEnviroScreen).
• Communities experiencing extremely high burdens associated with solid waste facilities are
all located in EJ Study Area 2 east of Interstate 805 and/or north of California State Route
905 (i.e., in the vicinity of Otay Landfill).
• For most of these indicators, there are additional communities that experience these
burdens in the 65th-89th percentile range.
Some communities may also experience high burdens (i.e., between the 65-89th percentiles, for
purposes of this analysis) for additional indicators not described above, including: exposure to
cleanup sites (e.g., Superfund sites) (four census tracts, plus one census tract above the 90th
percentile, located throughout the EJ Study Area), hazardous waste facilities (four census tracts,
plus one census tract above the 90th percentile, all located in EJ Study Area 2), groundwater threats
(three census tracts, plus one census tract above the 90th percentile, all located in EJ Study Area 2),
low birth weight (four census tracts, plus one census tract above the 90th percentile, all located in EJ
Study Area 2), and housing burdens (three census tracts, all located in EJ Study Area 2 west of
Interstate 805).
Because several communities in both EJ Study Areas 1 and 2 experience multiple social and
environmental burdens, there is potential for these burdens to result in cumulative impacts that
could further increase burdens felt by the community. These cumulative impacts and burdens may
not be captured by examining single indicators on their own but are important to consider in
determining potential strategies to mitigate impacts to communities. Population statistics for
certain indicators are provided in Table 3-22 and Table 3-23.
The review of other data sources described earlier in this section provided additional information
regarding social and environmental burdens within the EJ Study Area:
• Based on the review of HPI data, communities within the EJ Study Area may have
unhealthier conditions than other census tracts in San Diego County. For example, for the
following indicators that have been positively associated with life expectancy, some census
tracts in the EJ Study Area are below the 35th percentile, meaning that they have less healthy
conditions for these indicators than other areas: active commuting, tree canopy, voting,
homeownership, uncrowded housing, insured adults, and overall HPI score, in addition to
health-related indicators identified through EJScreen 2.0 and CalEnviroScreen 4.0 (Public
Health Alliance, 2022).
• Based on the review of the Good Neighbor Environmental Board's 17th Report,
communities within the EJ Study Area may be especially vulnerable to climate change
impacts including drought, rising temperatures, and extreme weather events. In addition,
the proximity of vulnerable populations to the San Ysidro Port of Entry (located at the U.S.-
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Mexico border where EJ Study Areas 1 and 2 meet) may exacerbate the adverse health
effects posed by traffic exposure. As described in Sections 3.11 (Air Quality and Odor) and
3.17 (Transportation), the San Ysidro Port of Entry is the busiest port of entry in the U.S. for
both private vehicles and pedestrians. It is located within the EJ Study Area, close to the
border between EJ Study Area 1 and EJ Study Area 2. Proximity to large numbers of idling
vehicles can cause exposure to toxic air pollutants. Both short-term high exposures in near-
traffic environments (e.g., pedestrians in wait lines adjacent to vehicular traffic) and longer-
term exposures in more remote environments (e.g., nearby schools and housing units) have
been linked to harmful health effects. Rising temperatures associated with climate change
will only exacerbate these air quality issues (Good Neighbor Environmental Board, 2016).
• Based on the review of SDAPCD'sAB 617: Community Air Protection Program Submittal,
the San Diego International Border Community, which surrounds the San Ysidro Port of
Entry, is identified as a priority area for a monitoring and emission reductions program
(SDAPCD, 2019a). The SDAPCD identifies the census tract containing the ITP parcel
(06073010009) as low income and low access to grocery stores, based on the 2015 USDA
Food Access Research Atlas. The SDAPCD identified and prioritized the San Diego
International Border Community because of significant socioeconomic factors, such as
existing burdens that negatively affect their ability to protect themselves from pollution
exposure. The community is also subject to elevated PM levels due to its location downwind
from Tijuana (SDAPCD, 2019a).
• Three census tracts in the vicinity of the ITP (06073010009, 6073010013, and
6073010111) are identified as DACs per SB 535 with CalEnviroScreen 4.0 percentiles of
74.7, 82.8, and 76.5, respectively (OEHHA, 2022). The census tract containing the ITP parcel
(06073010009) is under the 75 percent threshold but was previously designated as a DAC
in the 2017 version, which relied on the CalEnviroScreen 3.0 data, and therefore remains
designated as disadvantaged per the new definitions released in May 2022. Figure 3-34
shows the DACs in the vicinity of the Tijuana River Valley.
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Table 3-22. Communities in the EJ Study Area with Potential Environmental Justice Concerns Based on EJScreen 2.0 Data
Census Block
Group Number
Minority
Low-Income
County Percentiles for Other Selected Indicators of Overburden c,d
Percent of
County
Percent of
County
Unemployment
Air Toxics
Traffic
Wastewater
Population a
Percentile
Population b
Percentile
Cancer Risk
Proximity
Discharge
EJ Study Area 1
060730100091
100%
99th
86%
99th
78th
94th
78th
91st
060730100092
95%
95th
11%
19th
50th
94th
59th
91st
060730100093
98%
98th
62%
94th
39th
94th
71st
91st
060730100094
100%
99th
68%
96th
90th
94th
85th
91st
060730101091
85%
84th
14%
27th
57th
99th
60th
91st
EJ Study Area 2
060730100012
82%
81st
17%
35th
68th
94th
42nd
0th
060730100031
97%
98th
16%
32nd
62nd
94th
91st
0th
060730100041
92%
91st
48%
83rd
71st
99th
69th
84th
060730100042
97%
97th
37%
71st
94th
99th
79th
87th
060730100051
98%
98th
30%
63rd
91st
99th
81st
86th
060730100053
97%
97th
68%
96th
72nd
99th
70th
88th
060730100054
96%
96th
79%
99th
97th
99th
80th
89th
060730100121
96%
96th
11%
19th
41st
99th
55th
90th
060730100122
100%
99th
62%
93rd
96th
99th
74th
90th
060730100123
100%
99th
64%
94th
80th
99th
81st
90th
060730100142
88%
87th
17%
36th
50th
99th
68th
0th
060730100151
93%
93rd
22%
47th
46th
100th
80th
87th
060730101063
93%
93rd
53%
88th
97th
94th
94th
89th
060730101092
95%
96th
36%
70th
92nd
99th
84th
91st
060730101111
97%
97th
51%
86th
79th
99th
83rd
90th
060730101112
92%
91st
57%
91st
81st
99th
90th
90th
060730133061
91%
90th
28%
59th
91st
94th
89th
0th
060730133081
89%
89th
48%
83rd
96th
94th
93rd
0th
060730133121
87%
86th
24%
53rd
83rd
94th
87th
0th
060730133131
85%
84th
14%
26th
74th
94th
44th
0th
Source: (EPA, 2022g).
a - San Diego County has a minority population of 54 percent (EPA, 2022d).
b - San Diego County has a low-income population of 28 percent (EPA, 2022d).
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c - For each indicator and census block group, the percentiles indicate the degree of burden relative to that of all census block groups in San Diego County for
that indicator. For example, if a census block group is 48 percent minority and is at the 69th county percentile, this means that 48 percent of the population
within the census block group is minority, and that is an equal or higher percent minority than 69 percent of all census block groups in the county,
d - County percentiles for environmental indicators were calculated from the raw environmental indicator values (not the EJ Index values).
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Final Programmatic EIS: USMCA Mitigation of
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Affected Environment
Table 3-23. Communities in the EJ Study Area with Potential Environmental Justice Concerns Based
on CalEnviroScreen 4.0 Data
Census Tract Number
Percentiles for Other Selected Indicators of Overburden a
PM2.5
Diesel PM
Toxic Air Chemical
Releases from Facilities
EJ Study Area 1
6073010009
100th
78th
97th
6073010109 b
99th
19th
92nd
EJ Study Area 2
6073010001
97th
61st
98th
6073010003
98th
90th
99th
6073010004
99th
81st
98th
6073010005
99th
92nd
97th
6073010012
99th
82nd
96th
6073010014
98th
41st
99th
6073010015
98th
39th
99th
6073010106
97th
77th
95th
6073010111
99th
85th
95th
6073013306
96th
94th
99th
6073013308
95th
86th
98th
6073013312
96th
63rd
99th
6073013313
96th
25th
99th
Source: (CalEPA, 2021a).
a - For each indicator and census tract, the percentiles indicate the degree of burden relative to that of all census
tracts in San Diego County for that indicator.
b - A portion of Census Tract 6073010109 also falls within the boundaries of EJ Study Area 2.
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Final Programmatic EIS: USMCA Mitigation of
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Affected Environment
Minority
I I 87.5 -100 percentile
j 75 - 87.5 percentile
I 62.5 - 75 percentile
j 50 - 62.5 percentile
0 - 50 percentile
I I Proposed Action location
Example truck routes
Goat Canyon to UP
Smuggler's Gulch to ITP
ITP to Otay Landfill
Otay Landfill
SAN
DIEGO
CHULA
IMPERIAL vista
BEACH.
Tijuana
River -
Valley
Top label represents the blockgroup number.
Bottom label represents burden percentile compared to other blockgroups in the County.
Miles
Figure 3-25. Minority Percentile (County) for Block Groups in EJ Study Area, Based on EJScreen 2.0 Data
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Affected Environment
060730100093
730133061
I 59%
060730100012
35% t
060730100142
36%
060730100051
63%
>073010'
060730101091
27%
)73010(
19%
Low income
87.5 -100 percentile
H 75 - 87.5 percentile
_| 62.5 - 75 percentile
I 50 - 62.5 percentile
I 0 - 50 percentile
cud Proposed Action location
Example truck routes
Goat Canyon to UP
Smuggler's Gulch to ITP
ITP to Otay Landfill
IH
n
1i
i
EJ Study
Area 1
A
f \ I
m
100031
^^32%
fe. \
060730100042 \
L 71%
i ij/
0 307 3013312H
060730133131
26%
Otay Landfill
060730100151
47%
Top label represents the blockgroup number.
Bottom label represents burden percentile compared to other blockgroups in the County.
I Miles
A
%ERG
SAN
DIEGO
CHULA
IMPERIAL VISTA
BEACHv
Tijuana
River
Valley
Figure 3-26, Low-Income Percentile (County) for Block Groups in EJ Study Area, Based on EJScreen 2.0 Data
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Affected Environment
Unemployment rate
I | 87.5 - 100 percentile
_J 75 - 87.5 percentile
n 62.5 - 75 percentile
1 50 - 62.5 percentile
0-50 percentile
I I Proposed Action location
Example truck routes
Goat Canyon to UP
Smuggler's Gulch to ITP
ITP to Otay Landfill
060730133131
74%
Otay Landfill
060730100012
68% i^TJ
P0100031
62%
060730100142
50%
060730100041
71%
>7301000!
72% .
060730100151
46%
06073010(
^w39%
060730101091
57%
1730100C
50%
SAN
DIEGO
CHULA
IMPERIAL vista
BEACH.
Tijuana
River -
Valley
Top label represents the blockgroup number.
Bottom label represents burden percentile compared to other blockgroups in the County.
Miles
Figure 3-27. Unemployment Percentile (County) for Block Groups in EJ Study Area, Based on EJScreen 2.0 Data
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Affected Environment
060730133121
060730133061 94%
94%
060730133'
94%
060730133081
94%
060730100012
94%
060730100142
060730100131
94% /
060730100042 060730100041
99% 99%
060730101063_
060730100054 06073010005'
f QQ% 99%
060730,o(l2K07^^«!,oloo1^0730,00053
99% V 99„A
06073010lbq2
99% \ 060730100122
06073CT00123
060730100151
100%
060730100093
94%
060730101091
060730100092
060730100091 94 %
94%
060730100094
Air toxics cancer risk
I | 87.5 - 100 percentile
n 75 - 87.5 percentile
I 62.5 - 75 percentile
] 50 - 62.5 percentile
0-50 percentile
I I Proposed Action location
Example truck routes
Goat Canyon to UP
Smuggler's Gulch to ITP
ITP to Otay Landfill
Otay Landfill
SAN
DIEGO
CHULA
IMPERIAL vista
BEACH.
Tijuana
River -
Valley
Top label represents the blockgroup number.
Bottom label represents burden percentile compared to other blockgroups in the County.
Miles
Figure 3-28. Air Toxics Cancer Risk Percentile (County) for Block Groups in EJ Study Area, Based on EJScreen 2.0 Data
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Final Programmatic EIS: USMCA Mitigation of
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Affected Environment
^ 06073013312
¦¦0730133061 87%
I 89%
060730133081
$50730100f3f
i' 91 % /
Traffic proximity
I I 87.5 -100 percentile
j 75 - 87.5 percentile
I 62.5 - 75 percentile
] 50 - 62.5 percentile
0 - 50 percentile
I I Proposed Action location
Example truck routes
Goat Canyon to UP
Smuggler's Gulch to ITP
ITP to Otay Landfill
060730133131
44%
Otay Landfill
060730100012
42%
060730100142
68%
060730100041
69% ¦ I
|060730100p53
70% r
>73010012
060730101
£sw71%
060730101091
60%
>730100C
59%
SAN
DIEGO
CHULA
IMPERIAL vista
BEACH.
• ' '
Tijuana
River -
Valley
Top label represents the blockgroup number.
Bottom label represents burden percentile compared to other blockgroups in the County.
Miles
Figure 3-29. Traffic Proximity Percentile (County) for Block Groups in EJ Study Area, Based on EJScreen 2.0 Data
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Final Programmatic EIS: USMCA Mitigation of
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Affected Environment
Wastewater discharge
I I 87.5 -100 percentile
j 75 - 87.5 percentile
I 62.5 - 75 percentile
j 50 - 62.5 percentile
0 - 50 percentile
I I Proposed Action location
Example truck routes
Goat Canyon to UP
Smuggler's Gulch to ITP
ITP to Otay Landfill
0 50730133121
'30133061 0%
0%
060730133131
0%
Otay Landfill
>0730133081
0%
060730100012
0%
060730100142
0%
30100031
0%
SAN
DIEGO
CHULA
IMPERIAL vista
BEACH.
Tijuana
River -
Valley
Top label represents the blockgroup number.
Bottom label represents burden percentile compared to other blockgroups in the County.
Miles
Figure 3-30. Wastewater Discharge Percentile (County) for Block Groups in EJ Study Area, Based on EJScreen 2.0 Data
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Final Programmatic EIS: USMCA Mitigation of
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Affected Environment
6073013104 *
92%
6073012600
6073013310
6073013309
6073013103
93%
6073013303
94%
6073013203
94%
6073013306
96%
6073013310
96% J
6073013312
96%
6073013206
94%
6073013307
96%
6073013204
95%
6073013205
95%
J010103
6073013308
95%
6073010001
97%
6073010107
97%
607301001
6073010014
98%
6073010003
6073010010
6073010300
6073010402
97%
6073010004
99%
6073010106
97%
6073010110
97%
6073010104
97%
6073010112
/6073010111
6073010005
6073010200
95%
6073010012
6073010015
6073010013
6073010109
6073010009
100%
Particulate matter 2.5
_! 87.5 - 100 percentile
~ 75-87.5 percentile
i 62.5 - 75 percentile
I I 50 - 62.5 percentile
I 0 - 50 percentile
i i Proposed Action location
Example truck routes
Goat Canyon to UP
Smuggler's Gulch to ITP
ITP to Otay Landfill
SAN
DIEGO
CHULA
IMPERIAL vista
BEACH. ¦
Tijuana
River -
Valley
Top label represents the census tract number.
Bottom label represents burden percentile compared to other census tracts in the County.
Miles
Figure 3-31. PM2.5 Percentile (County) for Census Tracts in EJ Study Area, Based on CalEnviroScreen 4,0 Data
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Final Programmatic EIS: USMCA Mitigation of
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Affected Environment
6073010003
6073010112
6073010005
6073010012
6073010013
6073010009
173013104
27V--'"
6073013103
50%
W7301331:
6073013206
i 21%
6073010107
72%
6073010200
6073010109
19%
073013309
74%^
6073013203
19%
6073013303
Diesel particulate matter
_! 87.5 - 100 percentile
~Z\ 75 - 87.5 percentile
i 62.5 - 75 percentile
] 50 - 62.5 percentile
I 0 - 50 percentile
cud Proposed Action location
Example truck routes
Goat Canyon to UP
Smuggler's Gulch to ITP
ITP to Otay Landfill
6073013313
25%
6073013306
94%
6073013307
79%
6073013204
27%
Otay Landfill
6073013308
1010103
57%
60730
61
6073010011
17%
6073010014
41%
6073010010
49%
UUJU
•. M '¦
6073010300
28%
6073010402
6073010106
77%
6073010004
6073010110
6073010104
38%
EJ Study
Area 1
6073010015
SAN
DIEGO
CHULA
IMPERIAL VISTA
BEACH„
Tijuana
River
Valley
«ERG
A
Miles
TIJUANA
Top label represents the census tract number.
Bottom label represents burden percentile compared to other census tracts in the County.
Figure 3-32. Diesel PM Percentile (County) for Census Tracts in EJ Study Area, Based on CalEnviroScreen 4.0 Data
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Final Programmatic EIS: USMCA Mitigation of
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Affected Environment
Toxic air chemical releases from facilities
| 87.5 -100 percentile
Zl 75 - 87.5 percentile
| 62.5 - 75 percentile
I I 50 - 62.5 percentile
I 0 - 50 percentile
i i Proposed Action location
Example truck routes
Goat Canyon to UP
Smuggler's Gulch to UP
UP to Otay Landfill
6073013103
94%
6073010402
90%
6073013203 6073013303
96% 98%
6073013206
96% 6073013204
6073013205 96%
95%
6073013312 607301331ft
6073010107
94%
• ' L
/
805
6073010011 I
6073010010 97o/o 6073010003
96% 99% /
6073010106
6073010104 6073010110 95%
92%
6073010014
99%
6073010004
98%
6073010112
93%
/6073010111
\ 95%
6073010005
97%
6073010013
97%
6073010109
92%
y
m
—¦v
6073010009
97%
Ife ""V* -N
Top label represents the census tract number.
Bottom label represents burden percentile compared to other census tracts in the County.
r'j k" - r t . Bit5 i irrK}
0 0.25 0.5 0.75 1
I Miles
A
%ERG
CHULA
IMPERIAL viSTA
BEACHv
Tijuana
River
Valley
Figure 3-33. Toxic Air Chemical Releases Percentile (County) for Census Tracts in EJ Study Area, Based on CalEnviroScreen 4.0 Data
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Final Programmatic EIS: USMCA Mitigation of
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Affected Environment
SSSfJKgl
RSsir smSE
SSM(m»
Siij-Ji*.
:
SB 535 Disadvantaged Communities
f M P E RIAV B EACH
OJAY.M ESAj
NAVAL OUTLYING
LANDING FIELD
IMPERIAL BEACH
SANfcVSIDRO)
[Monument' Rq |
[CamirToTdi^
[uTHted^sta^
MEXICO
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Label represents the census tract number.
Figure 3-34. SB 535 DACs
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Final Programmatic EIS: USMCA Mitigation of
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Affected Environment
Potentially Affected Communities in Mexico
Vulnerable communities in Mexico exist along the U.S.-Mexico border in Tijuana. The ATLAS report
developed by the Secretaria de Desarrollo Territorial, Urbano y Ambiental presented a socio-
environmental vulnerability index for Tijuana, Mexico, based on indicators such as social (e.g., level
of education, access to health services), economic (e.g., employment), quality of living and housing,
infrastructure, and environment (Secretaria de Desarrollo Territorial, Urbano y Ambiental, 2022).
Based on the vulnerability index, the neighborhoods near where the Tijuana River crosses the U.S.-
Mexico border have mid-high, high, and very high index scores. Neighborhoods with the highest
levels of poverty in Tijuana include Aeropuerto, Libertad, Zona Norte, Los Laureles, and Zona
Centro, all of which are located along the U.S.-Mexico border and near where the Tijuana River
crosses the border.
In addition, in Mexico, indigenous groups and Afro-Mexican communities face disproportionate
exposure to environmental harms based on their demographics and lack of sociopolitical power.
Lastly, vulnerable communities in Mexico include migrants in refugee settlements that await
asylum processing in informal housing in Tijuana.
See Section 6.1.14 (Environmental Justice) for additional information about EO requirements.
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Environmental Consequences
4. ENVIRONMENTAL CONSEQUENCES
This section includes an analysis of the environmental consequences, or impacts, of the Proposed
Action. Impacts of the Proposed Action described in each of the following resource sections are
considered significant in the context of NEPA if they meet the standards for significance defined for
each resource. As discussed in Section 1.5 (Purpose and Scope of the Programmatic EIS), this
analysis includes disclosure of transboundary effects between the U.S. and Mexico. Transboundary
effects are discussed in each of the following resource sections and are summarized in Table 4-1
below.
Table 4-1. Summary of Potential Transboundary Effects Under the Proposed Action
Alternative
Project Title
Project
Location
Transboundary Effects
From Action in U.S.
From Action in
Mexico
Alternative 1: Core Projects
Alternative 2: Core + Supplemental Projects
A. Expanded ITP
U.S. only
Short-term construction impacts;
long-term impacts from ITP
operation
N/Aa
B. Tijuana Canyon
Flows to ITP
U.S. and
Mexico
Short-term construction impacts
Short-term
construction impactsa
C. Tijuana Sewer
Repairs
Mexico only
N/A
Short-term
construction impactsa
D. APTP Phase 1
U.S. and
Mexico
Short-term construction impacts;
long-term impacts from APTP
operation
Short-term
construction impactsa
E. APTP Phase 2
U.S. only
Short-term construction impacts;
long-term impacts from APTP
operation
N/Ab
F. U.S.-side River
Diversion to APTP
U.S. only
Short-term construction impacts
N/Ab
G. New SABTP
Mexico only
N/A
Short-term
construction impactsa
H. Tijuana WWTP
Treated Effluent Reuse
Mexico only
N/A
Short-term
construction impactsa
1. ITP Treated Effluent
Reuse
U.S. and
Mexico
Short-term construction impacts
Short-term
construction impacts
J. Trash Boom(s)
U.S. only
Short-term construction impacts;
long-term impacts from trash
extraction and processing
N/Ab
a - Project would change transboundary effects by reducing contaminated transboundary flows from Mexico to
the U.S. In some cases, these transboundary effects would be due to actions in the U.S. that result in operational
changes in Mexico (e.g., sending more wastewater to the U.S. for treatment).
b - Project would address contaminated river flows after they have entered the U.S. Therefore, for purposes of
this table, this is not considered a transboundary effect to the U.S.
4-1
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Final Programmatic EIS: USMCA Mitigation of
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Environmental Consequences
4.1 Freshwater and Estuarine Resources
4.1.1 Standards of Significance
Impacts to freshwater and estuarine resources would be significant if they were to include any of
the following:
• Dredge, fill, or removal or other hydrological disruption of wetlands or jurisdictional waters
of the U.S. resulting in the need for an individual CWA 404 permit
• Drawdown of groundwater by a substantial amount to the detriment of groundwater-
dependent habitat.
• Substantial degradation of water quality.
• Creation of substantial erosion or runoff either on or off site and/or contribution of runoff
that would exceed the capacity of existing or planned stormwater drainage systems.
4.1.2 No-Action Alternative
The No-Action Alternative would include the continuation of existing impacts to freshwater and
estuarine resources that are currently resulting from contaminated transboundary flows from
Tijuana (see Section 1.3 [Causes and Impacts of Contaminated Transboundary Flows from Tijuana]
and Section 3.1 [Freshwater and Estuarine Resources]). These impacts would persist unabated and
would worsen over time as wastewater infrastructure in Tijuana continues to deteriorate and the
population continues to grow without access to adequate wastewater treatment infrastructure.
4.1.3 Alternative 1: Core Projects
Temporary Effects
Under Alternative 1, construction activities for the Core Projects would include potential minor,
short-term impacts to water resources as described below. However, Alternative 1 would not result
in significant impacts to freshwater and estuarine resources per the criteria in Section 4.1.1
(Standards of Significance).
Projects A (Expanded ITP) and/or D (APTP Phase 1) at the ITP parcel would potentially involve
temporary construction activities (e.g., staging) in the vicinity of two features identified as potential
wetlands under CCC jurisdiction (PEM Wetland 5 and PSS Wetland 6), a drainage channel identified
as a potential jurisdictional water of the U.S. (Clearwater Swale 1), and a small ditch identified as a
potential jurisdictional water of the state (Clearwater Ditch 1). Project B (Tijuana Canyon Flows to
ITP) would include temporary construction activities in Smuggler's Gulch that would occur in the
vicinity of the Palustrine Scrub-Shrub wetland and intermittent stream channel that were
delineated as potential jurisdictional waters of the U.S. These projects would incorporate BMPs
(e.g., spill prevention and erosion and sediment control measures) to mitigate the minor, short-
term impacts to water quality from construction-related activities.
Project B, Option B1 would result in temporary open-cut trenching along Monument Road that
would potentially, depending on the final design and siting location of the pipeline, cross two
potentially jurisdictional waters of the U.S. (MRTrib 1 and MRTrib 2),resulting in direct and
temporary impacts. If impacts to the waters are unavoidable and if these tributaries are determined
to be jurisdictional waters of the U.S., then activities associated with this construction would
4-2
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
require compliance with CWA Section 404 and would likely fall under a Section 404 Nationwide
Permit 58 for Utility Line Activities for Water and Other Substances. The activity may also be
eligible for enrollment under a RWQCB General Order to meet Section 401 Water Quality
Certification and Waste Discharge Requirements. Depending on the final design and siting location,
the activities may also require a Lake and Streambed Alteration (LSA) Agreement with the CDFW,
and/or a CDP from the CCC. The minor, short-term impacts on water quality associated with
construction-related activities from the Core Projects would be minimized through implementation
of construction BMPs.
No discharges to groundwater would occur during construction, and all activities would be handled
pursuant to spill prevention procedures to avoid impacts to groundwater. Construction activities
would not impact drinking water resources because none are present within the affected area.
Construction activities would adhere to the storm water management permitting requirements
described in Section 6.1.2 (Freshwater and Estuarine Resources). Construction activities would be
required to implement temporary erosion, sediment, good housekeeping, and pollution prevention
BMPs to mitigate stormwater pollutants during the construction phase. Examples of potential BMPs
include perimeter controls (e.g., silt fencing, track pads, filter rolls), temporary stabilization (e.g.,
cover and containment for stockpiles, grass seeding, perpendicular grading), proper storage of fuels
and other chemicals, covering waste containers when not in use, and proper maintenance of
concrete washout areas.
Construction activities would not be expected to affect any water-dependent recreational activities.
Construction and pipeline repair activities in Mexico under Projects B, C (Tijuana Sewer Repairs),
and D would not result in direct or indirect transboundary impacts to freshwater or estuarine
resources in the U.S. since minor construction impacts would be limited to the areas of construction
in Mexico.
Permanent Effects
Under Alternative 1, implementation of the Core Projects would be expected to eliminate dry-
weather transboundary flows and pollutant loadings in the Tijuana River and substantially reduce
the number of days per year with transboundary river flows, while resulting in only minor
reductions in the total volume of transboundary river flows over the course of a typical year. These
impacts are presented in detail below. Alternative 1 would not result in significant impacts to
freshwater and estuarine resources per the criteria in Section 4.1.1 (Standards of Significance) and
is anticipated to have long-term beneficial impacts on water quality and wetlands in the Tijuana
River and the Tijuana River Estuary.
Table 4-2 summarizes the estimated impacts that Alternative 1 would have on transboundary flows
and pollutant loadings in the Tijuana River.
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Table 4-2. Impacts on Transboundary Flows in the Tijuana River - Alternative 1
Projectsa
Flow Days
Flow Volume
BODs Load
Days/yr
Percent
Change
Billion gal/yr
Percent
Change
Tons/yr
Percent
Change
Current conditions b
153
N/A
17.5
N/A
1,670
N/A
Project C onlyc
79
-48%
16.9
-3%
660
-60%
Project D onlyd
73
-52%
16.7
-5%
1,210
-28%
Alternative 1 maximum
(Projects C + D)
68
-56%
16.5
-6%
562
-66%
a - Projects A and B would result in negligible or no changes to transboundary river flows.
b - Current conditions were calculated using Tijuana River flow data from January 2016 through January 2022,
during a period when PB-CILA capacity was 23 MGD. This analysis assumes that future baseline transboundary
river flow conditions will be similar to those represented in this historical period of flow data and estimates the
projects' effectiveness at reducing transboundary flows under these future baseline conditions,
c-Assumes Project C reduces untreated wastewater in the Tijuana River in Mexico down to 5 MGD. Reflects PB-
CILA reliably diverting flows up to 23 MGD. Impact of Project C on transboundary river flows would be less if PB-
CILA is capable of reliably diverting more than 23 MGD with the recent (2021-22) upgrades,
d - Reflects PB-CILA, with new/rehabilitated conveyance line, reliably diverting flows up to 35 MGD (bypassing
PB1-A).
As summarized above, implementation of the Core Projects—specifically, Projects C (Tijuana Sewer
Repairs) and D (APTP Phase 1), whether performed independently or in combination—would
substantially decrease the frequency of transboundary river flows (by 56 percent) and the
associated pollutant loadings to the Tijuana River in the U.S. Nutrient loadings in transboundary
river flows would be reduced by up to approximately 439 tons/yr if only Project C were
implemented; 203 tons/yr if only Project D were implemented; and 467 tons/yr if both projects
were implemented. Loadings of numerous other pollutants to the Tijuana River in the U.S. would
also be reduced—including ammonia, bacteria, BODs, phosphorous, surfactants, and various metals
including copper, nickel and zinc, all of which are present at elevated levels in the Tijuana River in
Mexico (IBWC, 2020). The reduction in pollutant loadings from untreated wastewater would
potentially help alleviate impaired water listings for the Tijuana River and the Tijuana River
Estuary (e.g., due to reduced loadings of bacteria, nutrients, and BOD5); would potentially help the
Tijuana River meet the beneficial uses listed in the San Diego Water Board's Basin Plan; would be
expected to improve groundwater quality in the Tijuana Groundwater Basin; and would be
expected to improve downstream conditions for water-dependent recreational activities in the
Tijuana River and the Tijuana River Estuary. Water quality improvements would also potentially
reduce contamination levels in sediment from the Tijuana River and increase the potential for
suitable reuse of extracted sediment However, these projects would result in a negligible reduction
in transboundary sediment loads (less than 1 percent51) and only incidental trash removal, and
thus would not substantially change sediment or trash volumes in the Tijuana River Valley.
Implementation of Projects C and D would decrease the cumulative volume of transboundary river
flows by up to approximately 1.00 billion gallons per year (BGY) (3,070 ac-ft/year), which equates
to a 6 percent reduction in annual flow.
51 This estimate does not account for potential reductions in sediment loadings that are known to be caused
by erosion around leaking sewer collectors in Tijuana, which would be rehabilitated or replaced under
Project C.
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Environmental Consequences
EPA and USIBWC conducted an additional analysis to illustrate the potential impacts of the Core
Projects on transboundary river flows during different portions of the rainfall season. The analysis
used historical stream gage data from the 2016 through 2019 rainfall years (i.e., May 1, 2016,
through April 30, 2020)52 to represent future baseline transboundary river flow conditions and
estimated the projects' effectiveness at reducing transboundary flows under these future baseline
conditions. The following assumptions were made to define seasons, rainfall year, and dry weather
for the analysis:
• The wet season is defined as October 1 through the following March 31.
• The dry season is defined as May 22 through September 7 (to approximate Memorial Day
and Labor Day, respectfully).
• The full rainfall year is defined as May 1 through the following April 30.
• Dry-weather days are defined as the periods occurring at least five days after the most
recent precipitation registered at San Diego International Airport and during which the
river flow rate does not exceed 23 MGD (as higher flow rates are potentially indicative of
stormwater in the river, potentially due to precipitation elsewhere in the watershed). Flows
on dry-weather days can occur at any time of the year when the river diversion and
pumping system is not functioning as designed.
The results of this analysis are presented in Table 4-3. Additionally, EPA and USIBWC created a
series of charts that 1) depict historical transboundary river flows from the 2000 through 2020
rainfall years, categorized by season and dry weather conditions, and 2) illustrate the portion of
those transboundary flows that could have been prevented if the Core Projects were retroactively
implemented (this is applied only to the more recent 2016 through 2020 rainfall years). These
charts, which are presented in Figure 4-1, Figure 4-2, and Figure 4-3, help to illustrate how the
expected frequency and volume of future transboundary river flows (following implementation of
the Core Projects) would compare to historical transboundary flows during different portions of the
rainfall season.
During the dry season, implementation of the Core Projects would eliminate transboundary river
flows other than the occasional wet-weather flow that exceeds 35 MGD. By preventing the types of
dry-season flows that have become more frequent since the 2017 rainfall year, implementation of
the Core Projects would be expected to result in future dry-season flow conditions that more
closely resemble historical conditions since 2000, as depicted in Figure 4-1 and Figure 4-2. During
most of this 21-year period, a typical dry season has featured fewer than 10 days with river flows
(i.e., less than 10 percent of dry-season days have flows) and less than 100 MG of total flow over the
course of the season.
During the wet season, implementation of the Core Projects would allow for the diversion of dry-
weather flows and very small wet-weather flows of up to 35 MGD. This would be expected to
52 This analysis and the analysis presented in Table 4-2 are based on different ranges of historical stream gage
data. The two analyses therefore result in different characterizations of current conditions (which also
represent assumed future baseline conditions). However, both analyses provided similar estimates of the
Core Projects' potential impacts on those future baseline conditions (e.g., both estimate a 6 percent reduction
in total annual flow volume).
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Final Programmatic EIS: USMCA Mitigation of
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Environmental Consequences
reduce wet-season transboundary river flow days by approximately 32 percent (37 fewer days of
wet-season flows, on average). However, this change equates to only a 6 percent reduction in total
wet-season flow volume because it would not affect wet-weather flows that exceed 35 MGD, which
contribute the significant majority of annual flows in the Tijuana River (see Table 3-1). The reduced
wet-season flows following implementation of the Core Projects would be expected to be generally
consistent, in terms of frequency and volume, with historical conditions since 2000 as depicted in
Figure 4-1 and Figure 4-2. Because of the shutoff protocols for the PB-CILA river diversion under
Project D, implementation of the Core Projects would not mitigate impacts to the river or estuary
resulting from extreme weather events.
During a typical rainfall year, implementation of the Core Projects would reduce transboundary
river flow days by approximately 46 percent (80 fewer days of flows, on average), equating to a 6
percent reduction in total annual flow volume. The reduced flows following implementation of the
Core Projects would be expected to be generally consistent, in terms of frequency and volume, with
historical conditions since 2000 as depicted in Figure 4-1 and Figure 4-2.
As shown in Table 4-3 and Figure 4-3, implementation of the Core Projects would be expected to
eliminate dry-weather transboundary flows (approximately 43 days per year, on average) and the
associated pollutant loadings in the Tijuana River.
Table 4-3. Impacts on Transboundary Flows in the Tijuana River, by Portion of Rainfall Year (Annual
Averages, Based on Data for 2016 Through 2019 Rainfall Years) - Alternative 1
Portion of Rainfall
Year
Flow Days
Flow Volume (MG)
Cu rrent
Conditionsa
Alternative 1
Maximum
(Projects C + D)bc d
Percent
Change
Cu rrent
Conditionsa
Alternative 1
Maximum
(Projects C + D)bc d
Percent
Change
Full rainfall year
171
91
-46%
20,848
19,577
-6%
Wet season only
118
81
-32%
17,643
16,670
-6%
Dry season only
17
0.5
-97%
99
22
-78%
"Dry weather"
conditions onlye
43
0
-100%
167
0
-100%
a - Calculations are based on Tijuana River stream gage data from the 2016 through 2019 rainfall years (i.e., May 1,
2016, through April 30, 2020), during a period when PB-CILA capacity was 23 MGD. These calculations exclude
stream gage data from the outlier 2020 rainfall year due to the near-constant shutdown of the PB-CILA river
diversion throughout the 2020 dry season. This analysis assumes that future baseline transboundary river flow
conditions would be similar to those represented in this historical period of flow data and estimates the projects'
effectiveness at reducing transboundary flows under these future baseline conditions,
b - Projects A and B would result in negligible or no changes to transboundary river flows,
c - Assumes Project C reduces untreated wastewater in the Tijuana River in Mexico down to 5 MGD. Reflects PB-
CILA reliably diverting flows up to 23 MGD. Impact of Project C on transboundary river flows would be less if PB-
CILA is capable of reliably diverting more than 23 MGD with the recent (2021-2022) upgrades,
d - Reflects PB-CILA, with new/rehabilitated conveyance line, reliably diverting flows up to 35 MGD (bypassing
PB1-A).
e - For purposes of this analysis, "dry weather" conditions indicate that the flow occurred at least five days after
the most recent precipitation registered at San Diego International Airport, and that the flow rate did not exceed
23 MGD. A select few flow events that exceeded the 23-MGD threshold were considered dry weather because
they occurred at a time of year with no registered precipitation, and/or because they varied only slightly above 23
MGD during a period that was predominantly dry weather.
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Final Programmatic EIS: USMCA Mitigation of
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Environmental Consequences
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Targeted by Alternative 1
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Final Programmatic EIS: USMCA Mitigation of
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Environmental Consequences
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Targeted by Alternative 1
4-8
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Final Programmatic EIS: USMCA Mitigation of
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Environmental Consequences
140
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the most recent precipitation registered at San Diego International Airport, and that the flow rate did not exceed
23 MGD. A select few flow events that exceeded the 23-MGD threshold were considered dry weather because
they occurred at a time of year with no registered precipitation, and/or because they varied only slightly above 23
MGD during a period that was predominantly dry weather.
Figure 4-3. Dry-Weather Transboundary Flow Days and Volume in the Tijuana River per Rainfall Year
(2000-2020) and Portion Targeted by Alternative 1
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Final Programmatic EIS: USMCA Mitigation of
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The overall reduction in transboundary river flow volume, while modest (approximately 6 percent),
would likely have a beneficial impact on downstream efforts to counteract the increasing
freshwater influence on salt marsh habitat in the Tijuana River Estuary, as discussed in Section
3.1.1 (Hydrology).
EPA and USIBWC also considered whether the estimated surface flow reductions in the river would
potentially have an effect on groundwater levels and riparian vegetation and habitat The Core
Projects would target the diversion of dry-weather flows and a very small portion of wet-weather
flows (i.e., when PB-CILA is operational), a substantial portion of which would otherwise be
expected to infiltrate to the alluvial aquifer before reaching the estuary, depending on the flow rate
and saturation conditions. The surface flow reduction would take place over the course of several
years as pipeline repairs are performed in Tijuana under Project C and as the reliability and
capacity of the river diversion system increases under Project D. As discussed in Section 3.1.1
(Hydrology), the Natural Safe Yield for the Tijuana Groundwater Basin has been estimated at
approximately 5,000-6,800 ac-ft/year. However, EPA and USIBWC understand that these estimates
do not account for contributions from untreated transboundary sewage flows (Rempel, 1992). The
Natural Safe Yield of the Tijuana Groundwater Basin following implementation of the Core Projects
is therefore expected to remain similar to past estimates, indicating a surplus of groundwater that
would continue supporting baseflows in reaches of the Tijuana River downstream of Dairy Mart
Road Bridge. Also, as noted above, implementation of the Core Projects would not affect wet-
weather transboundary river flow events that saturate the wider floodplain, fill ponds and other
depressions, and gradually recharge the aquifer. Transboundary river flow conditions after Core
Project implementation would be expected to be generally consistent, in terms of frequency and
volume, with historical conditions since 2000 (excepting the 2017 and 2020 rainfall years, which
had unusually frequent dry-weather transboundary flows). EPA and USIBWC are consulting with
USFWS regarding this potential impact See Section 4.4 (Inland Biological Resources) for further
discussion.
Projects A (Expanded ITP) and B (Tijuana Canyon Flows to ITP) would result in negligible or no
changes to transboundary river flows. Project A would potentially reduce untreated wastewater
overflows from the sanitary sewer to the Tijuana River caused by mechanical failures at PB1-B;
however, its primary purpose is to provide additional treatment capacity for flows that otherwise
would discharge to the coast via SAB Creek. Project B would result in no changes in transboundary
river flows but would potentially reduce the amount of contaminated transboundary dry-weather
flows in Goat Canyon and Smuggler's Gulch by eliminating the reliance on pump stations whose
mechanical issues may cause occasional wastewater overflows into the canyons in Mexico.
Operations under the Core Projects would not result in any impacts to wetlands or other delineated
aquatic resources other than through the changes in the frequency, magnitude, and pollutant
loadings of transboundary river flows described above. Operations would not introduce a new
demand for groundwater and would not impact drinking water resources because none are present
within the affected area.
Projects A and D would construct up to approximately 12.3 acres of new impervious surfaces at the
ITP parcel and would thus increase stormwater runoff from the site to the Tijuana River. Due to the
increase in new impervious surfaces, permanent, post-construction BMP requirements would apply
to the projects. Per guidance from the County of San Diego BMP Design Manual (County of San
Diego, 2020c) and permitting and regulatory requirements described in Section 6.1.2 (Freshwater
and Estuarine Resources), both projects would be required to incorporate design measures to
prevent any net increase in stormwater runoff and maintain predevelopment hydrology to the
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Final Programmatic EIS: USMCA Mitigation of
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Environmental Consequences
maximum extent technically feasible. Examples of low-impact design alternatives that would be
considered include incorporating pervious pavements, bioretention areas, rain gardens, and swales.
Sufficient land is expected to be available within the ITP parcel to incorporate low-impact design
alternatives into the project design, such as along rights of way, adjacent to buildings and roadways,
and in unused parcels. If proposed low-impact design alternatives would not meet the expected
design capture volume requirements, then storm water requirements could potentially result in
inclusion of a small, permanent retention basin in the northwest area of the ITP parcel. If the
permanent stormwater retention basin is included as a post-construction BMP measure, it could be
constructed at the beginning of the construction phase to also provide sediment control during
construction activities. The feasibility of incorporating these permanent BMPs would be evaluated
further during the planning and design phase, and final permanent BMPs would be identified
during the county review process.
4.1.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Under Alternative 2, construction activities for the Core Projects would result in the same minor,
short-term impacts to freshwater and estuarine resources from construction-related activities as
would occur under Alternative 1. Construction activities for the Supplemental Projects would
include temporary construction activities in the Tijuana River main channel and floodplain,
resulting in temporary impacts to potential jurisdictional aquatic resources as described below and
resulting in at least one significant impact on freshwater and estuarine resources per the criteria in
Section 4.1.1 (Standards of Significance). Construction-related impacts would be mitigated through
the use of BMPs. (See the "Permanent Effects" discussion below regarding potential permanent
construction-related impacts to these aquatic features.)
Project E (APTP Phase 2) would involve construction activities in the vicinity of a potential CCC
jurisdictional wetland (PSS Wetland 6), and the current conceptual location for the treated effluent
pipeline under Project I (ITP Treated Effluent Reuse) runs through the site of a potential CCC
jurisdictional wetland (PEM Wetland 5). These projects would incorporate water quality BMPs (e.g.,
spill prevention and erosion and sediment control measures) to mitigate the potential minor, short-
term indirect impacts to these hydrologic features. The pipeline segment under Project I would be
installed via trenchless methods or, if this is not feasible, the location would be adjusted to avoid
direct impacts to this wetland.
Projects F (U.S.-side River Diversion to APTP) and J (Trash Boom[s]) would include temporary
construction activities in the Tijuana River main channel and the surrounding floodplain, which is
identified as a potential jurisdictional water of the U.S. For the river diversion, construction would
require temporary damming and flow diversion of the river. Flows associated with the Tijuana
River in this area are characterized as intermittent to ephemeral; therefore, the diversion is not
anticipated to result in downstream impacts on the river, as the features and resources associated
with the river are subject to long periods of zero flow. The specific construction-related impacts to
aquatic resources and the associated permitting and review requirements (e.g., CWA Section 404
permit authorization, RWQCB401 Water Quality Certification, LSA Agreement, and CDP) would be
evaluated in subsequent tiered NEPA analyses.
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No discharges to groundwater would occur during construction, and all activities would be handled
pursuant to spill prevention procedures so as to avoid impacts to groundwater. Construction
activities would not impact drinking water resources because none are present within the affected
area.
Construction activities would adhere to the stormwater management permitting requirements
described in Section 6.1.2 (Freshwater and Estuarine Resources).
Construction activities would not be expected to affect any water-dependent recreational activities
because water-based recreation is not present in the construction area or prevalent in the estuary.
Construction activities in Mexico would not result in transboundary impacts to freshwater or
estuarine resources in the U.S. because any effects on these resources would be localized to the
construction area in Mexico.
Permanent Effects
Under Alternative 2, implementation of the Core Projects would result in the same long-term
beneficial impacts to freshwater and estuarine resources as would occur under Alternative 1.
Implementation of the Supplemental Projects would further reduce transboundary flows and
pollutant loadings in the Tijuana River, as described below. Certain Supplemental Projects would
also directly impact potential jurisdictional aquatic resources. These impacts would potentially
result in significant, long-term impacts to freshwater and estuarine resources per the criteria in
Section 4.1.1 (Standards of Significance).
Table 4-4 summarizes the estimated impacts that Alternative 2 would have on transboundary flows
and pollutant loadings in the Tijuana River. This includes the impacts of Core Projects C (Tijuana
Sewer Repairs) and D (APTP Phase 1).
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Table 4-4. Impacts on Transboundary Flows in the Tijuana River - Alternative 2
Projectsa
Flow Days
Flow Volume
BODs Load
Days/yr
Percent
Change
Billion
gal/yr
Percent
Change
Tons/yr
Percent
Change
Current conditions b
153
N/A
17.5
N/A
1,670
N/A
Alternative 1 maximum c
68
-56%
16.5
-6%
562
-66%
Alternative 1 + Project F (35
MGD diversion)d
68
-56%
15.5
-11%
398
-76%
Alternative 1 + Projects E +
F (60 MGD diversion)e
43
-72%
14.1
-19%
238
-86%
Alternative 1 + Project H f
55
-64%
16.0
-9%
458
-73%
Alternative 2 maximum
(Alternative 1 + Projects E +
F [60 MGD diversion] + H)
36
-76%
13.8
-21%
214
-87%
a - Projects A, B, G, I, and J would result in negligible or no changes to transboundary river flows,
b - Current conditions were calculated using Tijuana River flow data from January 2016 through January 2022,
during a period when PB-CILA capacity was 23 MGD. This analysis assumes that future baseline transboundary
river flow conditions will be similar to those represented in this historical period of flow data and estimates the
projects' effectiveness at reducing transboundary flows under these future baseline conditions,
c-See Table 4-2.
d - Reflects 35-MGD diversion in U.S. operating at river flows up to 60 MGD.
e - Reflects 60-MGD diversion in U.S. operating at river flows up to 120 MGD, paired with Project E to provide
capacity to treat these flows.
f-Assumes Project H reduces Tijuana River flow in Mexico by 10.3 MGD, and Project C reduces untreated
wastewater in the Tijuana River in Mexico down to 5 MGD. Reflects PB-CILA reliably diverting river flows up to 35
MGD under Project D.
As summarized above, full implementation of the Supplemental Projects—specifically, Projects E
(APTP Phase 2), F (U.S.-side River Diversion to APTP), and H (Tijuana WWTP Treated Effluent
Reuse)—would result in a substantial further reduction in the frequency of transboundary river
flows and the associated pollutant loadings to the Tijuana River in the U.S., beyond what would be
achieved under Core Projects C and D. Nutrient loadings in transboundary river flows would be
further reduced by up to approximately 147 tons/yr if only Project F were implemented (35-MGD
option); 324 tons/yr if only Projects E and F were implemented (60-MGD option); 255 tons/yr if
only Project H were implemented; and 445 tons/yr if each project were implemented in addition to
the Core Projects. Loadings of numerous other pollutants to the Tijuana River in the U.S. would also
be reduced—including ammonia, bacteria, BODs, phosphorous, surfactants, and various metals
including copper, nickel and zinc, all of which are present at elevated levels in the Tijuana River in
Mexico (IBWC, 2020). This further reduction in pollutant loadings from untreated wastewater
would potentially help alleviate impaired water listings for the Tijuana River and the Tijuana River
Estuary (e.g., due to reduced loadings of bacteria, nutrients, and BOD5); would potentially help the
Tijuana River meet the beneficial uses listed in the San Diego Water Board's Basin Plan; would be
expected to improve groundwater quality in the Tijuana Groundwater Basin; and would be
expected to improve downstream conditions for water-dependent recreational activities in the
Tijuana River and the Tijuana River Estuary. Water quality improvements would also potentially
reduce contamination levels in sediment from the Tijuana River and increase the potential for
suitable reuse of extracted sediment However, these projects would result in a negligible reduction
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Final Programmatic EIS: USMCA Mitigation of
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in transboundary sediment loads (less than 2 percent)53 and thus would not substantially change
sediment volumes in the Tijuana River Valley.
As discussed in Section 4.13 (Solid and Hazardous Waste), the trash boom(s) under Project J would
be expected to substantially reduce the amount of floatable trash in transboundary river flows. This
would potentially help alleviate impaired water listings (for trash) for the Tijuana River and the
Tijuana River Estuary and would potentially help the Tijuana River meet the beneficial uses listed
in the San Diego Water Board's Basin Plan. However, further studies are necessary in support of the
subsequent tiered analyses to refine the estimates of how much trash would be successfully
removed from transboundary river flows.
Implementation of the Supplemental Projects would further decrease the cumulative volume of
transboundary flows in the river, particularly during smaller wet-weather events when a portion of
the flow would otherwise be expected to infiltrate to the alluvial aquifer before reaching the
estuary, depending on the flow rate and saturation conditions. Specifically (each of these represents
the additional, incremental reduction beyond the impacts of the Core Projects):
• Project F would further reduce transboundary river flows by up to approximately 2.40 BGY
(7,370 ac-ft/year) under the 60-MGD diversion option, assuming it is paired with the 60-
MGD treatment capacity at the APTP provided by Project E.
• Project H (Tijuana WWTP Treated Effluent Reuse) would further reduce transboundary
river flows by approximately 0.50 BGY (1,530 ac-ft/year).
• Full implementation of the Supplemental Projects would further reduce transboundary
river flows by up to approximately 2.70 BGY (8,290 ac-ft/year).
EPA and USIBWC do not have sufficient information at this time to estimate the extent to which
these transboundary wet-weather flow reductions would result in reduced infiltration to the
aquifer. Further hydrogeologic assessment is necessary to characterize the potential impacts to
factors including groundwater levels, groundwater-dependent vegetation, river baseflow in
downstream reaches, and saltwater intrusion. These impacts would be evaluated in subsequent
tiered NEPA analyses and related consultations. However, as noted below, implementation of the
Supplemental Projects would not affect larger wet-weather transboundary river flow events that
saturate the wider floodplain, fill ponds and other depressions, and gradually recharge the aquifer.
Implementation of the Supplemental Projects would not affect wet-weather transboundary river
flows that exceed the shutoff threshold of the Project F river diversion, other than through the 10.3-
MGD reduction of treated effluent in the river under Project H. Implementation of the Supplemental
Projects would not mitigate impacts to the river or estuary from extreme weather events, despite
the substantial reduction in the frequency of dry-weather and wet-weather transboundary river
flows.
53 This estimate does not account for potential reductions in sediment loadings that are known to be caused
by erosion around leaking sewer collectors in Tijuana, which would be rehabilitated or replaced under
Project C.
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
Projects G (New SABTP) and I (ITP Treated Effluent Reuse) would result in no changes to
transboundary river flows because they would not affect volumes of river flows in Mexico or
change the operation of the river diversion system.
The implementation of Projects F and J (Trash Boom[s]) would potentially result in a permanent
reduction in acreage of potential jurisdictional aquatic resources in the Tijuana River floodplain,
which may require an individual CWA 404 permit Additionally, recurring O&M of these features
(e.g., extraction of trash using heavy mobile equipment) would potentially result in further
disturbances to aquatic resources in the floodplain. The construction activities are not anticipated
to result in the relocation of the Tijuana River channel or a reduction in the primary functions of the
river. The specific impacts and associated mitigation requirements would be evaluated in
subsequent tiered NEPA analyses. Operations under the other Supplemental Projects would not
result in any impacts to wetlands or other delineated aquatic resources other than through the
changes in transboundary river flows described above. Operations would not introduce a new
demand for groundwater and would not impact drinking water resources because none are present
within the affected area.
Projects E, F, and J would potentially involve construction of new impervious surfaces in the U.S.
and, if so, would increase stormwater runoff to the Tijuana River. Applicability of County of San
Diego BMP Design Manual and EISA stormwater management requirements would be evaluated in
subsequent tiered NEPA analyses. Project E would likely require the incorporation of design
measures at the ITP parcel as described above for Alternative 1. Because Project F and J would
increase impervious surfaces in the floodplain, design alternatives to prevent any net increase in
stormwater runoff would be evaluated during the design phase and in subsequent tiered NEPA
analyses.
4.1.5 Comparative Analysis of the Alternatives
Table 4-5 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
Two of the alternatives would result in a significant, or potentially significant, impact on freshwater
and estuarine resources per the criteria in Section 4.1.1 (Standards of Significance). Section 5
(Mitigation Measures and Performance Monitoring) identifies the mitigation measures that would
be implemented for the Core Projects and provides recommended mitigation measures for the
Supplemental Projects (which would be further refined and developed in subsequent tiered NEPA
analyses).
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
Table 4-5. Comparative Analysis of Effects - Freshwater and Estuarine Resources
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Potential minor, short-term impacts
from open-cut trenching along
Monument Road to cross two
potentially jurisdictional waters of
the U.S., depending on final design
and siting location; these impacts
would not require an individual
CWA 404 permit
¦ No impacts to groundwater,
drinking water resources, or water-
dependent recreational activities
¦ No exceedance of stormwater
drainage systems
Same as Alternative 1, plus the
following:
¦ Potential minor, short-term impacts
to potentially jurisdictional waters of
the U.S. from construction of U.S.-side
river diversion and trash boom(s) in
Tijuana River main channel and
floodplain (see Section 5 for potential
mitigation measures)
Permanent
effects
¦ Continuation
of significant
impacts to
freshwater
and estuarine
resources and
continuation
of water
quality
degradation
(see Section 5
for potential
mitigation
measures)
¦ Long-term beneficial effects from
substantial reductions in pollutant
loadings and frequency of dry-
weather transboundary river flows
¦ Potential alleviation of impaired
water listings, assistance in meeting
the San Diego Water Board's Basin
Plan, improvements to
groundwater quality, and
improvements to water-dependent
recreational activities
¦ Potential reductions in
contaminated transboundary dry-
weather flows in Goat Canyon and
Smuggler's Gulch
¦ No change in groundwater demand
and no impacts to drinking water
resources
¦ Increase in stormwater runoff from
new impervious footprint
Same as Alternative 1, plus the
following:
¦ Potentially significant, long-term
reduction in acreage of potentially
jurisdictional waters of the U.S. in the
Tijuana River floodplain for the U.S.-
side river diversion and trash boom[s],
requiring an individual CWA 404
permit (see Section 5 for potential
mitigation measures)
¦ Long-term beneficial effects from
increased reductions in pollutant
loadings and frequency and volume of
transboundary river flows
¦ Substantial reduction in floatable
trash in transboundary river flows
¦ Increase in water quality-related
benefits
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
4.2 Marine Waters
4.2.1 Standards of Significance
Impacts to marine waters would be significant if they were to include any of the following:
• Inconsistency with the California Ocean Plan.
• Inability to meet discharge requirements or obtain NPDES permits for proposed discharges
to the ocean.
• Substantial increase in pollutant loadings discharged to the ocean from point or non-point
sources.
• Disruption of recreational and/or commercial activities that are dependent on marine
waters.
4.2.2 No-Action Alternative
The No-Action Alternative would result in the continuation of existing impacts to marine waters
that are currently resulting from the discharge of untreated wastewater into the Pacific Ocean (see
Section 1.3 [Causes and Impacts of Contaminated Transboundary Flows from Tijuana] and Section
3.2 [Marine Waters]). The amount of effluent treated at the ITP and discharged from the SBOO
would not substantially change as the ITP is already operating near capacity. Pollutant loadings to
the Pacific Ocean via SAB Creek and via transboundary river and canyon flows would persist
unabated and would worsen over time as wastewater infrastructure in Tijuana continues to
deteriorate and the population continues to grow without access to adequate wastewater
treatment infrastructure. This would worsen water quality and increase HAB events, beach
closures, and negative public health impacts.
4.2.3 Alternative 1: Core Projects
Temporary Effects
Under Alternative 1, construction activities for the Core Projects would result in minor, short-term
impacts to marine waters from activities associated with modifications to the wye diffuser array on
the SBOO for Projects A (Expanded ITP) and D (APTP Phase 1) as described in Section 4.5.3 (Marine
Biological Resources). Vessels required for these modifications would likely carry hydraulic fluids
and fuel, thus vessel activities would bring a small risk of oil spill and water pollution. Assuming
mitigation measures are maintained (see Section 5 [Mitigation Measures and Performance
Monitoring]), the likelihood of an oil spill occurring would be negligible. Additionally, vessel
operation and diver activity would potentially result in minor inconveniences to recreational and
commercial fishing activities. However, construction activities would occur over a relatively short
period of time (a few hours each day for a few weeks),would be localized to the area around the
southern leg of the SBOO, and would likely occur in phases over the course of several years. No
other components of the Core Projects would result in temporary effects on marine waters because
they would not involve disturbance or activities in the marine environment. Based on this and the
minor nature of impacts mentioned above, construction activities for Alternative 1 would not result
in significant impacts to marine waters per the criteria in Section 4.2.1 (Standards of Significance).
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
Permanent Effects
Under Alternative 1, implementation of the Core Projects would provide long-term beneficial
impacts from treatment of wastewater flows that would otherwise be discharged without
treatment to the Pacific Ocean via SAB Creek. Core Projects would also reduce the frequency of and
pollutant loadings from dry-weather transboundary river flows, some of which would otherwise
reach the Pacific Ocean via the Tijuana River Estuary. Overall, operation of all Core Projects would
result in a significant net reduction in pollutant loadings discharged to the Pacific Ocean. Core
Projects would be expected to meet discharge requirements and be able to obtain NPDES permits
and would not be expected to disrupt recreational or commercial activities dependent on marine
waters.
The following subsections discuss how implementation of the Core Projects would potentially
impact marine waters by reducing discharges of untreated wastewater to the Pacific Ocean via SAB
Creek; increasing discharges of treated effluent to the Pacific Ocean via the SBOO; and reducing
pollutant loadings that are conveyed to the Pacific Ocean via the Tijuana River and Estuary. This is
followed by a discussion of expected overall marine water quality improvements and the associated
reductions in beach impacts. While implementation of the Core Projects would result in overall
long-term benefits to marine water quality, the substantial increase in pollutant loadings
discharged via the SBOO would be considered a significant impact per the criteria in Section 4.2.1
(Standards of Significance).
Reduced Discharges of Untreated Wastewater via SAB Creek
Implementation of the Core Projects would immediately lead to significant reductions in discharges
of untreated wastewater to the Pacific Ocean via SAB Creek, as summarized in Table 4-6. The
majority of these improvements would be accomplished through Projects A (Expanded ITP), B
(Tijuana Canyon Flows to ITP), and C (Tijuana Sewer Repairs) by improving the collection and
treatment of wastewater in Tijuana.
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
Table 4-6. Impacts on Discharges to the Pacific Ocean via SAB Creek (Initial Operations) - Alternative
1
Projects
Untreated Wastewater
Flow Volume
BODs Load
Nutrient Load
Million
gallons/day
Percent
Change
Tons/yr
Percent
Change
Tons/yr
Percent
Change
Current conditions a
28.2
N/A
17,200
N/A
3,916
N/A
Project A, Option A1 (Expand
to 40 MGD) onlyc
13.4
-52%
8,175
-52%
1,763
-55%
Project A, Option A2 (Expand
to 50 MGD) only b c d
6.5
-11%
3,950
-77%
931
-76%
Project A, Option A3 (Expand
to 60 MGD) only b c d
6.5
-11%
3,950
-77%
931
-76%
Project D (35 MGD) onlyc
22.7
-20%
13,800
-20%
2,835
-28%
Alternative 1 maximum
(Projects A [Option A3] + D)
2.2
-92%
1,340
-92%
275
-93%
a - Current conditions were calculated using Tijuana River flow data from January 2016 through January 2022,
during a period when PB-CILA capacity was 23 MGD.
b - Reflects ITP treatment of inflows resulting from Project B (Tijuana Canyon Flows to ITP).
c - Reflects ITP treatment of inflows resulting from Project C (Tijuana Sewer Repairs).
d - Reflects changes in discharges and loadings that would be achieved upon startup of new treatment facilities
(i.e., before the full treatment capacity comes into service in response to population growth in Tijuana).
As shown above, implementation of the Core Projects would nearly eliminate discharges of
untreated wastewater to the Pacific Ocean via SAB Creek. This would result in substantial regional
coastal water quality improvements, leading to reduced negative impacts to beaches and public
health as discussed below (see Improvements in Marine Water Quality and Reduced Beach
Impacts) and in Section 4.16 (Public Health and Safety).
Implementation of the Core Projects would also reduce (by up to 93 percent) the portion of
sediment loads via SAB Creek that come from untreated wastewater or river water. These projects
would not affect sediment loads to the Pacific Ocean resulting from storm water and erosion within
the SAB Creek watershed.
Table 4-6 identifies the improvements that would occur upon startup of the new treatment
facilities. However, the 50-MGD and 60-MGD options of Project A provide additional treatment
capacity to accommodate projected population growth in Tijuana through the years 2030 and 2050,
respectively, assuming Tijuana canyon flows are treated at the ITP (Project B). The full water
quality benefits of these options would be realized once this additional treatment capacity comes
into service in response to population growth. To estimate these future improvements relative to
baseline conditions, EPA and USIBWC projected 2050 baseline conditions for discharges to SAB
Creek (i.e., assuming no infrastructure improvements are made) and estimated the impacts of the
Core Projects on this projected baseline. Table 4-7 summarizes these projected (2050) reductions
in discharges of untreated wastewater to the Pacific Ocean via SAB Creek.
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
Table 4-7. Impacts on Discharges to the Pacific Ocean via SAB Creek (Projected 2050 Conditions) -
Alternative 1
Projects
Untreated Wastewater
Flow Volume
BODs Load
Nutrient Load
Million
gallons/day
Percent
Change
Tons/yr
Percent
Change
Tons/yr
Percent
Change
Projected 2050 baseline
conditionsa
44.6
N/A
27,200
N/A
5,980
N/A
Project A, Option Al (Expand
to 40 MGD) onlyc
28.1
-37%
17,200
-37%
4,230
-29%
Project A, Option A2 (Expand
to 50 MGD) only b c d
18.3
-59%
11,200
-59%
2,980
-50%
Project A, Option A3 (Expand
to 60 MGD) only b c e
9.3
-79%
5,680
-79%
1,880
-69%
Project D (35 MGD) onlyc
37.8
-15%
23,100
-15%
4,750
-21%
Alternative 1 maximum
(Projects A [Option A3] + D)
5.4
-88%
3,310
-88%
674
-89%
a - Projected conditions in 2050 reflect estimates of additional wastewater generated due to projected population
growth in Tijuana with no corresponding improvements to wastewater treatment infrastructure,
b - Reflects ITP treatment of inflows resulting from Project B (Tijuana Canyon Flows to ITP).
c - Reflects ITP treatment of inflows resulting from Project C (Tijuana Sewer Repairs).
d - Reflects projected operations in 2030, when the 50-MGD ITP would be operating at full capacity based on
estimated population growth in Tijuana.
e - Reflects projected operations in 2050, when the 60-MGD ITP would be operating at full capacity based on
estimated population growth in Tijuana.
As shown above, implementation of Project A, Option A2 or Option A3 in particular, would be
projected to substantially reduce future discharges of untreated wastewater to the Pacific Ocean via
SAB Creek. The added capacity provided under Option A3 would help prepare for projected
conditions in 2050 and provide additional coastal water quality improvements through 2050,
achieving more than double the pollutant loading reductions that would occur under Option Al.
Implementation of Option A3 would also be projected to reduce (by up to 88 percent) the portion of
projected sediment loads via SAB Creek that would come from untreated wastewater or river
water. These projects would not affect sediment loads to the Pacific Ocean resulting from
stormwater and erosion within the SAB Creek watershed.
Increased Discharge of Treated Effluent via the SBOO
Implementation of the Core Projects would increase discharges of treated effluent to the Pacific
Ocean via the SBOO. The increase in discharges via the SBOO would consist of 1) additional
discharges of secondary-treated wastewater from the expanded ITP (Project A), with the volume of
discharged effluent depending on the capacity option, and 2) new discharges of primary-treated
river water from the new APTP Phase 1 (Project D). These increases in SBOO discharges would be
in addition to the current discharges of secondary-treated effluent from the existing ITP and
SBWRP.
Table 4-8 identifies the estimated changes in discharges via the SBOO that would occur upon
startup of the new treatment facilities. Table 4-9 identifies the estimated changes in discharges via
the SBOO as projected for the year 2050, when the 60-MGD expanded ITP (Project A, Option A3) is
projected to be at full capacity based on estimated population growth in Tijuana. In addition to
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
reflecting changes in discharges expected from the Proposed Action, these 2050 projections also
reflect an assumed increase in discharges from the SBWRP over this period.
Full implementation of the Core Projects (including the 60-MGD expanded ITP) would result in the
following changes to the flow rate, nutrient loadings, and BOD5 loadings of discharges via the SBOO:
• Flow Rate: The average daily SBOO effluent flow rate would immediately increase from
approximately 28.8 MGD under current conditions to approximately 65.2 MGD under initial
operating conditions of the expanded ITP and new 35-MGD APTP. The average daily SBOO
effluent rate would then gradually increase (over the course of the 20-year period from
2030 to 2050) to approximately 84.7 MGD by 2050 as the full capacity of the 60-MGD
expanded ITP comes into service in response to population growth in Tijuana. This
discharge would remain well below the SBOO design capacity of 174 MGD average daily
flow rate.
• BOD5: The annual BOD5 loadings in SBOO discharges would immediately increase from
approximately 533 tons/yr under current conditions to approximately 2,270 tons/yr under
initial operating conditions of the expanded ITP and new 35-MGD APTP. Annual BOD5
loadings would then gradually increase (over the course of the 20-year period from 2030 to
2050) to approximately 2,640 tons/yr by 2050.
• Nutrients: The total annual nutrient loadings (including total annual nitrogen and
phosphorous loadings) in SBOO discharges would immediately increase from
approximately 1,670 tons/yr under current conditions to approximately 4,240 tons/yr
under initial operating conditions of the expanded ITP and new 35-MGD APTP. The total
annual nutrient loadings would then gradually increase (over the course of the 20-year
period from 2030 to 2050) to approximately 5,280 tons/yr by 2050.
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
Table 4-8. Impacts on Discharges to the Pacific Ocean via the SBOO (Initial Operations) - Alternative 1
Parameter
Units
Current
Conditions,
Annual
Avga
Project A, Option
A1 (Expand to 40
MGD) Onlyc
Project A, Option
A2 (Expand to 50
MGD) Onlyb,cd
Project A, Option
A3(Expand to 60
MGD) Onlyb,cd
Project D (35 MGD)
Onlyc
Alternative 1
Maximum
(Projects A [Option
A3] + D)
Annual
Avg
%
Change
Annual
Avg
%
Change
Annual
Avg
%
Change
Annual
Avg
%
Change
Annual
Avg
%
Change
Effluent flow rate
MGD
28.8
43.8
52%
48.8
69%
48.8
69%
45.2
57%
65.2
126%
Temperature
deg C
23.4
23.3
0%
23.3
-1%
23.3
-1%
22.8
-3%
22.9
-2%
Ammonia-N
mg/L
8.52
8.88
4%
8.95
5%
8.95
5%
12.7
49%
11.7
38%
BODs
mg/L
12.1
13.7
13%
13.7
13%
13.7
13%
26.6
119%
22.9
88%
tons/yr
533
912
71%
1,020
92%
1,020
92%
1,830
244%
2,270
326%
Total nutrients
mg/L
38.0
39.3
3%
39.6
4%
39.6
4%
43.0
13%
42.6
12%
tons/yr
1,670
2,620
57%
2,940
76%
2,940
76%
2,960
78%
4,240
154%
Total dissolved
solids (TDS)
mg/L
1,320
1,330
1%
1,340
1%
1,340
1%
1,360
4%
1,360
4%
tons/yr
57,700
88,900
54%
99,300
72%
99,300
72%
93,900
63%
135,000
135%
TSS
mg/L
10.4
10.7
3%
10.7
3%
10.7
3%
10.6
2%
10.8
4%
tons/yr
456
712
56%
797
75%
797
75%
731
60%
1,070
135%
Fecal coliform
MPN/
100 mL
387,000
391,000
1%
392,000
1%
392,000
1%
433,000
12%
423,000
9%
Cadmium (total
recoverable)
Hg/L
0.117
0.122
4%
0.123
5%
0.123
5%
0.0816
-31%
0.0969
-17%
Ib/yr
10.3
16.3
58%
18.3
78%
18.3
78%
11.2
9%
19.3
87%
Copper (total
recoverable)
Hg/L
3.77
3.46
-8%
3.49
-7%
3.49
-7%
6.19
64%
5.45
45%
tons/yr
0.143
0.231
61%
0.259
81%
0.259
81%
0.426
197%
0.541
277%
Lead (total
recoverable)
Hg/L
0.130
0.133
2%
0.133
2%
0.133
2%
0.219
68%
0.194
49%
Ib/yr
11.4
17.7
55%
19.8
73%
19.8
73%
30.1
163%
38.5
236%
Mercury (total
recoverable)
Hg/L
0.0504
0.0464
-8%
0.0468
-7%
0.0468
-7%
0.0698
38%
0.0638
27%
tons/yr
0.00192
0.00310
61%
0.00348
81%
0.00348
81%
0.00481
150%
0.00634
230%
Nickel (total
recoverable)
Hg/L
18.7
19.5
4%
19.7
5%
19.7
5%
14.4
-23%
16.4
-12%
Ib/yr
1,640
2,610
59%
2,930
78%
2,930
78%
1,980
21%
3,270
99%
Selenium (total
recoverable)
Hg/L
5.11
5.35
5%
5.39
6%
5.39
6%
4.69
-8%
5.03
-2%
Ib/yr
448
713
59%
802
79%
802
79%
646
44%
1,000
123%
Thallium (total
recoverable)
Hg/L
2.07
2.08
1%
2.09
1%
2.09
1%
2.09
1%
2.10
1%
Ib/yr
181
278
53%
310
71%
310
71%
288
59%
417
130%
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
Table 4-8. Impacts on Discharges to the Pacific Ocean via the SBOO (Initial Operations) - Alternative 1
Parameter
Units
Current
Conditions,
Annual
Avga
Project A, Option
A1 (Expand to 40
MGD) Onlyc
Project A, Option
A2 (Expand to 50
MGD) Onlyb,cd
Project A, Option
A3(Expand to 60
MGD) Onlyb,cd
Project D (35 MGD)
Onlyc
Alternative 1
Maximum
(Projects A [Option
A3] + D)
Annual
Avg
%
Change
Annual
Avg
%
Change
Annual
Avg
%
Change
Annual
Avg
%
Change
Annual
Avg
%
Change
Zinc (total
recoverable)
Hg/L
16.9
15.6
-8%
15.7
-7%
15.7
-7%
17.5
4%
17.3
3%
tons/yr
0.642
1.04
62%
1.17
82%
1.17
82%
1.21
88%
1.72
168%
a - Current conditions (25 MGD for the UP and 3.8 MGD for the SBWRP) were calculated using 2015-2020 effluent monitoring data,
b - Reflects UP treatment of inflows resulting from Project B (Tijuana Canyon Flows to ITP).
c - Reflects ITP treatment of inflows resulting from Project C (Tijuana Sewer Repairs).
d - Reflects changes in discharges and loadings that would be achieved upon startup of new treatment facilities (i.e., before the full treatment capacity comes
into service in response to population growth in Tijuana).
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
Table 4-9. Impacts on Discharges to the Pacific Ocean via the SBOO (Projected 2050 Conditions) - Alternative 1
Parameter
Units
No Action,
Annual
Avga
Project A, Option
A1(Expand to 40
MGD) Onlyc
Project A, Option
A2 (Expand to 50
MGD) Onlyb,cd
Project A, Option
A3 (Expand to 60
MGD) Onlyb,ce
Project D (35 MGD)
Onlyc
Alternative 1
Maximum
(Projects A [Option
A3] + D)
Annual
Avg
%
Change
Annual
Avg
%
Change
Annual
Avg
%
Change
Annual
Avg
%
Change
Annual
Avg
%
Change
Effluent flow rate
MGD
33.2
48.2
45%
58.2
75%
68.2
105%
49.7
49%
84.7
155%
Temperature
deg C
23.7
23.5
-1%
23.4
-1%
23.4
-1%
23.0
-3%
23.0
-3%
Ammonia-N
mg/L
7.62
8.22
8%
8.45
11%
8.61
13%
11.7
54%
10.8
42%
BODs
mg/L
11.3
13.0
15%
13.2
17%
13.4
18%
24.8
118%
20.5
81%
tons/yr
574
953
66%
1,170
104%
1,390
143%
1,870
227%
2,640
360%
Total nutrients
mg/L
34.8
36.9
6%
37.8
9%
38.4
10%
40.4
16%
40.9
18%
tons/yr
1,760
2,710
54%
3,350
90%
3,990
126%
3,050
74%
5,280
200%
TDS
mg/L
1,270
1,300
2%
1,310
3%
1,320
4%
1,330
4%
1,340
6%
tons/yr
64,500
95,700
48%
116,000
81%
137,000
113%
101,000
56%
173,000
169%
TSS
mg/L
9.67
10.1
5%
10.3
7%
10.5
8%
10.8
12%
11.0
14%
tons/yr
490
746
52%
916
87%
1,090
122%
821
68%
1,420
189%
Fecal coliform
MPN/
100 mL
375,000
383,000
2%
386,000
3%
388,000
3%
421,000
12%
412,000
10%
Cadmium (total
recoverable)
Hg/L
0.105
0.113
8%
0.116
11%
0.119
13%
0.0764
-27%
0.0992
-5%
Ib/yr
10.6
16.6
57%
20.6
94%
24.6
132%
11.6
9%
25.6
141%
Copper (total
recoverable)
Hg/L
3.29
3.15
-4%
3.26
-1%
3.33
1%
5.65
72%
4.87
48%
tons/yr
289
464
60%
578
100%
693
140%
855
196%
1,260
335%
Lead (total
recoverable)
Hg/L
0.106
0.116
9%
0.119
13%
0.122
16%
0.194
84%
0.171
62%
Ib/yr
10.7
17.0
59%
21.2
98%
25.4
137%
29.4
175%
44.0
312%
Mercury (total
recoverable)
Hg/L
0.0443
0.0426
-4%
0.0439
-1%
0.0449
1%
0.0639
44%
0.0583
32%
tons/yr
3.89
6.25
61%
7.79
100%
9.32
140%
9.67
149%
15.0
287%
Nickel (total
recoverable)
Hg/L
16.6
18.0
8%
18.6
12%
18.9
14%
13.4
-20%
16.6
0%
Ib/yr
1,690
2,650
57%
3,290
95%
3,930
133%
2,030
20%
4,270
154%
Selenium (total
recoverable)
Hg/L
4.50
4.90
9%
5.06
13%
5.17
15%
4.31
-4%
4.93
10%
Ib/yr
455
721
58%
897
97%
1,070
136%
653
43%
1,270
179%
Thallium (total
recoverable)
Hg/L
2.02
2.05
1%
2.06
2%
2.07
2%
2.06
2%
2.08
3%
Ib/yr
205
302
47%
366
79%
431
110%
311
52%
537
162%
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
Table 4-9. Impacts on Discharges to the Pacific Ocean via the SBOO (Projected 2050 Conditions) - Alternative 1
Parameter
Units
No Action,
Annual
Avga
Project A, Option
A1(Expand to 40
MGD) Onlyc
Project A, Option
A2 (Expand to 50
MGD) Onlyb,cd
Project A, Option
A3 (Expand to 60
MGD) Onlyb,ce
Project D (35 MGD)
Onlyc
Alternative 1
Maximum
(Projects A [Option
A3] + D)
Annual
Avg
%
Change
Annual
Avg
%
Change
Annual
Avg
%
Change
Annual
Avg
%
Change
Annual
Avg
%
Change
Zinc (total
recoverable)
Hg/L
14.9
14.3
-4%
14.7
-1%
15.0
1%
16.1
8%
16.4
10%
tons/yr
1,310
2,100
61%
2,610
100%
3,130
140%
2,440
87%
4,230
224%
a - Projected 2050 conditions under the No-Action Alternative (25 MGD for the UP and 8.26 MGD for the SBWRP) were calculated using 2015-2020 effluent
monitoring data. The projected SBWRP effluent flow rate to the SBOO assumes operations will increase to use the plant's full 15 MGD capacity by 2050, while
continuing to reuse the same percentage of treated effluent as they do under current operations (approximately 55 percent),
b - Reflects ITP treatment of inflows resulting from Project B (Tijuana Canyon Flows to ITP).
c - Reflects ITP treatment of inflows resulting from Project C (Tijuana Sewer Repairs).
d - Reflects projected operations in 2030, when the 50-MGD ITP would be operating at full capacity based on estimated population growth in Tijuana,
e - Reflects projected operations in 2050, when the 60-MGD ITP would be operating at full capacity based on estimated population growth in Tijuana.
4-25
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
These tables are not a comprehensive list of all potential pollutants of concern that could be
discharged via the SBOO. For example, because the APTP would provide primary treatment of
diverted dry-weather flows from the Tijuana River, the range and concentrations of pollutants in
the treated effluent via the SBOO would be influenced by factors including industrial discharges and
agricultural runoff within and upstream of Tijuana. These are pollutants that, in the absence of the
proposed APTP, would have otherwise been discharged (untreated) to the Pacific Ocean via SAB
Creek, or would have potentially reached the Tijuana River Estuary and Pacific Ocean via
transboundary river flows. Examples could include surfactants, pesticides, and phthalates.54 Of
note, IBWC conducted water quality sampling in the Tijuana River and Alamar River in 2019 and
identified elevated levels of bis (2-ethylhexyl) phthalate at all monitoring sites, possibly due to
chemical leaching from plastics and solid waste discarded in the river (IBWC, 2020). However, the
river samples had low levels of organics and pesticides, and none of the river samples had
detectable levels of toxic parameters of concern such as hexavalent chromium or the carcinogenic
pesticides DDT and Aldrin (IBWC, 2020).
EPA and USIBWC conducted outfall plume transport modeling using the UM3 nearfield model
coupled with the Brook's far-field dispersion model from the Visual Plumes software suite to
analyze the differences in potential pollutant transport from SBOO discharges under current and
future conditions. For purposes of this modeling effort, EPA and USIBWC assumed average daily
flows of 35 MGD for the baseline scenario and 110 MGD for future conditions (which is
considerably higher than the average daily flow rate projected for 2050 in Table 4-9),55 with
modifications to the SBOO diffuser ports to accommodate the increased flow. This effort produced
both nearfield dilution estimates and estimates of potential far-field transport processes over a
longer time-period. The results, presented in Appendix J (South Bay Ocean Outfall Plume Transport
Modeling), indicate that pollutant concentrations in far-field environments following
implementation of the Core Projects would increase relative to baseline conditions, but that—
depending on the specific number and configuration of open diffuser ports—pollutant
concentrations would potentially decrease within a limited nearfield area around the SBOO (e.g.,
within approximately 300 to 500 meters of the point of discharge, based on the specific port
configuration modeled for this effort). This phenomenon could be due, in part, to the increase in
effective length of the diffuser achieved by bringing more ports into service to accommodate
additional flow. See Appendix J (South Bay Ocean Outfall Plume Transport Modeling) and Section
4.5 (Marine Biological Resources) for additional discussion.
54 Because PB-CILA (the pump station that would convey diverted river flows to the APTP) would not be
capable of operating when the instantaneous river flow rate exceeds 35 MGD, the APTP influent and
subsequent discharges of primary-treated effluent via the SBOO would not be expected to include significant
amounts of runoff-driven pollutants such as pesticides.
55 This modeled alternative scenario of 110 MGD represents a 214 percent increase in average daily flow
above the assumed baseline of 35 MGD. After the completion of model runs under this effort, EPA refined its
estimate of current SBOO discharges to 28.8 MGD (instead of 35 MGD) and refined its estimate of projected
2050 discharges under the Core Projects to 84.7 MGD (instead of 110 MGD). This refined estimate represents
a 194 percent increase in projected average daily flow above the baseline. The modeled scenarios therefore
represent a conservative model construction that likely overestimates the expected changes in the SBOO
effluent plume under the Core Projects.
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
Reduced Loadings via the Tijuana River and Estuary
As discussed in Section 4.1 (Freshwater and Estuarine Resources), implementation of the Core
Projects would substantially reduce dry-weather transboundary flows and pollutant loadings in the
Tijuana River. For example, BOD5 loadings in these transboundary flows would be reduced from
approximately 1,670 tons/yr to 562 tons/yr with full implementation of the Core Projects.
EPA and USIBWC assume that these improvements would result in reduced pollutant loadings to
the Pacific Ocean via the Tijuana River. However, due to the complex hydrogeologic processes in the
Tijuana River and Estuary described in Section 3.1 (Freshwater and Estuarine Resources), EPA and
USIBWC are not able to estimate the proportion of these reduced pollutant loadings that would
have otherwise eventually been transported to the Pacific Ocean (e.g., through groundwater or wet-
weather flows).
Improvements in Marine Water Quality and Reduced Beach Impacts
The estimated decreases in pollutant loadings to the Pacific Ocean via SAB Creek and the Tijuana
River described above far outweigh the estimated increases in loadings from discharge of treated
effluent via the SBOO. Implementation of the Core Projects would therefore be expected to result in
significant marine water quality benefits in the Pacific Ocean. Net reductions in nutrient loadings to
the Pacific Ocean would potentially reduce the formation of HABs along the coastline and the
associated health risks to wildlife and humans.
In particular, reducing discharges of untreated wastewater via SAB Creek is expected to result in
substantial improvements to coastal water quality and reduced beach impacts during the tourist
(dry) season—i.e., Memorial Day to Labor Day. In a recent modeling study, the Scripps Institution of
Oceanography examined the frequency and causes of water quality-driven human health impacts
at four beaches along the U.S. and Mexican coasts, based on four56 wastewater input scenarios
representing different combinations of untreated wastewater contributions from SAB Creek and
the Tijuana River (Feddersen et al., 2021). In this study, the authors estimated the following for
each beach and input scenario:
• Shoreline norovirus concentrations.
• Number of ill swimmers (Nm) due to exposure to norovirus pathogens in untreated
wastewater discharges.
• Beach impact fraction (BIF), which is the fraction of time that the modeled mean (expected)
probability of swimmer illness exceeds 0.036 (i.e., 36 per 1,000) due to exposure to
norovirus pathogens in untreated wastewater discharges (Feddersen et al., 2021).
The model results indicate that untreated wastewater from SAB Creek is the dominant cause of
swimmer illness at regional beaches during the tourist (dry) season (Feddersen et al., 2021).
Drawing from the modeled relationship between discharges of untreated wastewater via SAB Creek
and the resulting beach impacts, EPA and USIBWC interpolated the expected tourist (dry) season
56 At EPA's request, the Scripps Institution of Oceanography also performed a supplemental model run to
calculate beach impact fraction for a fifth scenario that is not documented in the published report. See
Appendix K (Interpolation of Modeled Beach Impacts) for more information.
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
impacts at regional beaches that would result from implementation of the Core Projects.57 See
Appendix K (Interpolation of Modeled Beach Impacts) for the interpolation methodology. The
results are presented in Table 4-10 and Table 4-11. These results demonstrate that full
implementation of the Core Projects would immediately lead to significant reductions in water
quality-driven human health impacts at regional beaches during the tourist (dry) season.
Table 4-10. Impacts on Tourist (Dry) Season Nm at Imperial Beach (Initial Operations) - Alternative 1
Project
Untreated
Wastewater from
SAB Creek (MGD)
Imperial Beach
Nin e
Percent
Change
Current conditions a
28.2
21,352
N/A
Project A, Option Al (Expand to 40 MGD) onlyc
13.4
11,779
-45%
Project A, Option A2 (Expand to 50 MGD) only bc d
6.5
7,315
-66%
Project A, Option A3 (Expand to 60 MGD) only bc d
6.5
7,315
-66%
Project D (35 MGD) onlyc
22.7
17,794
-17%
Alternative 1 maximum (Projects A [Option A3] + D)
2.2
4,534
-79%
a - Current conditions were calculated using Tijuana River flow data from January 2016 through January 2022,
during a period when PB-CILA capacity was 23 MGD.
b - Reflects ITP treatment of inflows resulting from Project B (Tijuana Canyon Flows to ITP).
c - Reflects ITP treatment of inflows resulting from Project C (Tijuana Sewer Repairs).
d - Reflects changes in discharges and loadings that would be achieved upon startup of new treatment facilities
(i.e., before the full treatment capacity comes into service in response to population growth in Tijuana),
e - Nin is defined as the number of ill swimmers due to exposure to norovirus pathogens in untreated wastewater
discharges. Results are interpolated from those of two scenarios in Feddersen et al. (2021) representing 0 MGD
and 35 MGD of untreated wastewater from SAB Creek. See Appendix K (Interpolation of Modeled Beach Impacts)
for additional information, including discussion of how this interpolation potentially overestimates Nni reductions
for certain projects.
57 In this PEIS, EPA and USIBWC have not attempted to predict changes in beach closures under the Proposed
Action. Instead, this PEIS uses Nm and BIF to represent "beach impacts." Projects that would reduce the
estimated Nm and BIF at regional beaches are expected to have a corresponding potential to reduce beach
closures. However, actual beach closures are implemented pursuant to the County of San Diego's beach water
quality monitoring program, and future reductions in the frequency and duration of beach closures may differ
from these estimated reductions in "beach impacts."
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
Table 4-11. Impacts on Tourist (Dry) Season Beach Impact Fraction (Initial Operations) - Alternative
1
Project
Untreated
Wastewater
from SAB
Creek (MGD)
Playas Tijuana
Imperial Beach
Silver Strand
Beach
Hotel del
Coronado
BIFe
%
Change
BIFe
%
Change
BIFe
%
Change
BIFe
%
Change
Current conditions a
28.2
0.576
N/A
0.396
N/A
0.292
N/A
0.212
N/A
Project A, Option Al
(Expand to 40 MGD)
onlyc
13.4
0.490
-15%
0.297
-25%
0.193
-34%
0.099
-53%
Project A, Option A2
(Expand to 50 MGD)
only b-c'd
6.5
0.330
-43%
0.178
-55%
0.110
-62%
0.047
-78%
Project A, Option A3
(Expand to 60 MGD)
only b-c'd
6.5
0.330
-43%
0.178
-55%
0.110
-62%
0.047
-78%
Project D (35 MGD)
onlyc
22.7
0.544
-6%
0.359
-9%
0.255
-13%
0.170
-20%
Alternative 1
maximum (Projects
A [Option A3] + D)
2.2
0.156
-73%
0.060
-85%
0.037
-87%
0.016
-92%
a - Current conditions were calculated using Tijuana River flow data from January 2016 through January 2022,
during a period when PB-CILA capacity was 23 MGD.
b - Reflects ITP treatment of inflows resulting from Project B (Tijuana Canyon Flows to ITP).
c - Reflects ITP treatment of inflows resulting from Project C (Tijuana Sewer Repairs).
d - Reflects changes in discharges and loadings that would be achieved upon startup of new treatment facilities
(i.e., before the full treatment capacity comes into service in response to population growth in Tijuana),
e - BIF is defined as the fraction of time that the modeled mean (expected) probability of swimmer illness exceeds
0.036 (i.e., 36 per 1,000) due to exposure to norovirus pathogens in untreated wastewater discharges. Results are
interpolated from those of two scenarios in Feddersen et al. (2021) representing 0 MGD and 35 MGD of untreated
wastewater from SAB Creek and a third scenario (F. Feddersen, personal communication, April 23, 2022)
representing 10 MGD of untreated wastewater from SAB Creek. See Appendix K (Interpolation of Modeled Beach
Impacts) for additional information.
4.2.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Under Alternative 2, construction activities for the Core Projects would result in the same minor,
short-term impacts to marine waters as would occur under Alternative 1. Most construction
activities for the Supplemental Projects would not result in impacts to marine waters. One
exception is the potential modifications to the wye diffuser array on the SBOO for Project E (APTP
Phase 2), which would have the same impacts as described for the Core Projects. Additionally, it is
possible that the scope of Project G (New SABTP) could be modified to include installation of a
subaquatic discharge pipe. In that scenario, the subsequent tiered NEPA analysis for Project G
would assess the potential for transboundary effects on marine waters. These actions would not be
expected to result in significant impacts to marine waters per the criteria in Section 4.2.1
(Standards of Significance).
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
Permanent Effects
Under Alternative 2, implementation of the Core Projects would result in the same long-term
beneficial impacts to marine waters as would occur under Alternative 1—specifically, a significant
net reduction in pollutant loadings to the Pacific Ocean, but with a substantial increase in loadings
discharged via the SBOO.
As discussed below, implementation of the Supplemental Projects would expand these impacts and
improvements by:
• Providing additional treatment capacity for wastewater flows that would otherwise be
discharged without treatment to the Pacific Ocean via SAB Creek.
• Further reducing pollutant loadings from transboundary river flows, some of which would
otherwise reach the Pacific Ocean via the Tijuana River Estuary.
• Further increasing pollutant loadings from treated effluent discharged via the SBOO.
The substantial increase in pollutant loadings discharged via the SBOO would be considered a
significant, long-term impact per the criteria in Section 4.2.1 (Standards of Significance).
Supplemental Projects would be expected to meet discharge requirements and be able to obtain
NPDES permits and therefore would not be expected to disrupt recreational or commercial
activities dependent on marine waters.
Reduced Discharges of Untreated Wastewater via SAB Creek
Under Alternative 2, implementation of the Core Projects would result in the same reductions in
discharges via SAB Creek as would occur under Alternative 1. Implementation of Supplemental
Project G would provide treatment capacity for the remainder of untreated wastewater flows that
are not addressed by the Core Projects, resulting in the additional improvements shown in Table
4-12.
No other Supplemental Projects would impact discharges of untreated wastewater to the Pacific
Ocean via SAB Creek because they are instead focused on addressing other transboundary flows.
Table 4-12. Impacts on Discharges to the Pacific Ocean via SAB Creek - Alternative 2
Projectsa
Untreated Wastewater
Flow Volume
BODs Load
Nutrient Load
Million
gallons/day
Percent
Change
Tons/yr
Percent
Change
Tons/yr
Percent
Change
Current conditions b
28.2
N/A
17,200
N/A
3,916
N/A
Alternative 1 maximum c
2.2
-92%
1,340
-92%
275
-93%
Alternative 2 (Alternative 1
+ Project G)
0.1
-100%
54
-100%
131
-97%
a - Project G is the only Supplemental Project that would result in non-negligible changes to discharges via SAB
Creek.
b - Current conditions were calculated using Tijuana River flow data from January 2016 through January 2022,
during a period when PB-CILA capacity was 23 MGD.
c-See Table 4-6.
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
Increased Discharge of Treated Effluent via the SBOO
Under Alternative 2, implementation of the Core Projects would result in the same increases in
discharges via the SBOO as would occur under Alternative 1. Implementation of Supplemental
Projects E and F (U.S.-side River Diversion to APTP) would result in the diversion and treatment of
additional Tijuana River flows and would therefore result in a further increase (beyond that of the
Core Projects) in the amount of primary-treated effluent discharged to the Pacific Ocean via the
SBOO. In the absence of the proposed APTP, the pollutants in this effluent would have otherwise
potentially reached the Tijuana River Estuary and Pacific Ocean via transboundary river flows.
Implementation of Supplemental Project H (Tijuana WWTP Treated Effluent Reuse) in addition to
Projects E and F would help to offset some of this projected increase in treated effluent discharges
via the SBOO.
Table 4-13 identifies the estimated changes in discharges via the SBOO that would occur upon
startup of the new treatment facilities. Table 4-14 identifies the estimated changes in discharges via
the SBOO as projected for the year 2050, when the 60-MGD expanded ITP (Project A, Option A3) is
projected to be at full capacity based on estimated population growth in Tijuana. In addition to
reflecting changes in discharges expected from the Proposed Action, these 2050 projections also
reflect an assumed increase in discharges from the SBWRP over this period.
Full implementation of the Core and Supplemental Projects (including the 60-MGD expanded ITP)
would result in the following changes to the flow rate, nutrient loadings, and BODs loadings of
discharges via the SBOO:
• Flow Rate: The average daily SBOO effluent flow rate would immediately increase from
approximately 28.8 MGD under current conditions to approximately 62.5 MGD under initial
operating conditions of the expanded ITP and new 60-MGD APTP—a slightly smaller
increase than under the Core Projects alone. The average daily SBOO effluent rate would
then gradually increase (over the course of the 20-year period from 2030 to 2050) to
approximately 86.6 MGD by 2050 as the full capacity of the 60-MGD expanded ITP comes
into service in response to population growth in Tijuana—a slightly greater increase than
under the Core Projects alone. This discharge would remain well below the SBOO design
capacity of 174 MGD average daily flow rate.
• BOD5: The annual BOD5 loadings in SBOO discharges would immediately increase from
approximately 533 tons/yr under current conditions to approximately 2,440 tons/yr under
initial operating conditions of the expanded ITP and new 60-MGD APTP—a slightly greater
increase than under the Core Projects alone. Annual BOD5 loadings would then gradually
increase (over the course of the 20-year period from 2030 to 2050) to approximately 2,810
tons/yr by 2050—a slightly greater increase than under the Core Projects alone.
• Nutrients: The total annual nutrient loadings (including total annual nitrogen and
phosphorous loadings) in SBOO discharges would immediately increase from
approximately 1,670 tons/yr under current conditions to approximately 3,940 tons/yr
under initial operating conditions of the expanded ITP and new 60-MGD APTP—a slightly
smaller increase than under the Core Projects alone. The total annual nutrient loadings
would then gradually increase (over the course of the 20-year period from 2030 to 2050) to
approximately 5,050 tons/yr by 2050—a slightly smaller increase than under the Core
Projects alone.
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
The subsequent tiered NEPA analyses for these projects would evaluate the specific estimated
changes in loadings and marine water quality impacts resulting from these increases in SBOO
discharges.
Table 4-13. Impacts on Discharges to the Pacific Ocean via the SBOO (Initial Operations) -
Alternative 2
Projectsa
Effluent Flow Volume
BODs Load
Nutrient Load
Million
gallons/day
Percent
Change
Tons/yr
Percent
Change
Tons/yr
Percent
Change
Current conditions b
28.8
N/A
533
N/A
1,670
N/A
Alternative 1 maximum b
65.2
126%
2,270
326%
4,240
154%
Alternative 1 + Project F (35
MGD diversion)c
67.7
135%
2,350
341%
4,330
160%
Alternative 1 + Projects E + F
(60 MGD diversion)d
71.3
148%
2,420
355%
4,450
167%
Alternative 1 + Project H e
57.7
100%
2,320
335%
3,810
128%
Alternative 2 maximum
(Alternative 1 + Projects E +
F [60 MGD diversion] + H)
62.5
117%
2,440
358%
3,940
136%
a - Projects G, I, and J would result in no changes to discharges via the SBOO.
b - See Table 4-8.
c - Reflects 35-MGD diversion in U.S. operating at river flows up to 60 MGD.
d - Reflects 60-MGD diversion in U.S. operating at river flows up to 120 MGD, paired with Project E to provide
capacity to treat these flows.
e - Assumes Project H reduces Tijuana River flow in Mexico by 10.3 MGD, and Project C reduces untreated
wastewater in the Tijuana River in Mexico down to 5 MGD. Reflects PB-CILA reliably diverting river flows up to 35
MGD under Project D.
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Final Programmatic EIS: USMCA Mitigation of
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Environmental Consequences
Table 4-14. Impacts on Discharges to the Pacific Ocean via the SBOO (Projected 2050 Conditions) -
Alternative 2
Effluent Flow Volume
BODs Load
Nutrient Load
Projectsa
Million
Percent
Tons/yr
Percent
Tons/yr
Percent
gallons/day
Change
Change
Change
No action b
33.2
N/A
574
N/A
1,760
N/A
Alternative 1 maximum b
84.7
155%
2,640
360%
5,280
200%
Alternative 1 + Project F (35
87.2
162%
2,720
374%
5,380
206%
MGD diversion)c
Alternative 1 + Projects E + F
90.8
173%
2,790
387%
5,490
212%
(60 MGD diversion)d
Alternative 1 + Project H e
80.8
143%
2,690
368%
4,900
178%
Alternative 2 maximum
86.6
161%
2,810
389%
5,050
187%
(Alternative 1 + Projects E +
F [60 MGD diversion] + H)
a - Projects G, I, and J would result in no changes to discharges via the SBOO.
b - See Table 4-9.
c - Reflects 35-MGD diversion in U.S. operating at river flows up to 60 MGD.
d - Reflects 60-MGD diversion in U.S. operating at river flows up to 120 MGD, paired with Project E to provide
capacity to treat these flows.
e - Assumes Project H reduces Tijuana River flow in Mexico by 10.3 MGD, and Project C reduces untreated
wastewater in the Tijuana River in Mexico down to 5 MGD. Reflects PB-CILA reliably diverting river flows up to 35
MGD under Project D.
Reduced Loadings via the Tijuana River and Estuary
Under Alternative 2, implementation of the Core Projects would result in the same reductions in
transboundary pollutant loadings to the Tijuana River as would occur under Alternative 1. As
discussed in Section 4.1 (Freshwater and Estuarine Resources), implementation of Supplemental
Projects E, F, and H would result in a substantial further reduction in the frequency of
transboundary river flows and the associated pollutant loadings to the Tijuana River in the U.S.
EPA and USIBWC assume that these improvements would result in reduced pollutant loadings to
the Pacific Ocean via the Tijuana River. However, due to the complex hydrogeologic processes in the
Tijuana River and Estuary described in Section 3.1 (Freshwater and Estuarine Resources), EPA and
USIBWC are not able to estimate the proportion of these reduced pollutant loadings that would
have otherwise eventually been transported to the Pacific Ocean (e.g., through groundwater or wet-
weather flows).
Improvements in Marine Water Quality and Reduced Beach Impacts
Implementation of Supplemental Project G would result in further reductions in water quality-
driven human health impacts at regional beaches by providing treatment capacity for all remaining
wastewater discharges via SAB Creek. Specifically, EPA and USIBWC estimate that implementation
of all Core Projects plus Project G would eliminate more than 99 percent of the modeled BIF for
beaches in southern San Diego County during the tourist (dry) season.
Subsequent tiered NEPA analyses would further assess the relationships of the changes in pollutant
loadings via SAB Creek, via the SBOO, and to the Tijuana River to determine whether those changes
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would constitute a net reduction in loadings to the marine environment and therefore a benefit to
marine water quality.
4.2.5 Comparative Analysis of the Alternatives
Table 4-15 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
All three alternatives would result in significant impacts to marine water resources per the criteria
in Section 4.2.1 (Standards of Significance). Section 5 (Mitigation Measures and Performance
Monitoring) identifies the mitigation measures that would be implemented for the Core Projects
and provides recommended mitigation measures for the Supplemental Projects (which would be
further refined and developed in subsequent tiered NEPA analyses).
Table 4-15. Comparative Analysis of Effects - Marine Waters
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Potential for minor, short-term impacts
from pollution associated with vessel
activities during modifications to SBOO
¦ Minor, short-term localized
inconveniences to fishing activities
during modifications to SBOO
¦ No inconsistencies with California Ocean
Plan, exceedances of discharge
requirements, or increase in pollutant
loadings to the ocean
Same as Alternative 1
Permanent
effects
¦ Continuation,
and worsening
over time, of
significant
existing
marine water
quality
impacts (see
Section 5 for
potential
mitigation
measures)
¦ Significant, long-term impacts from
substantial increase in pollutant loadings
to Pacific Ocean via the SBOO, due to
expanded wastewater treatment
capacity in U.S. (see Section 5 for
potential mitigation measures);
expected to be consistent with the
California Ocean Plan
¦ Long-term beneficial effects from
reduction in pollutant loadings to Pacific
Ocean via SAB Creek and Tijuana River
Estuary
¦ Overall net reduction in pollutant
loadings discharged to the Pacific Ocean
¦ Significant, long-term benefits to marine
water quality, marine wildlife health,
human health, and beaches
¦ No exceedances of discharge
requirements or disruptions to
recreational/commercial activities that
depend on marine waters
Same as Alternative 1, plus the
following:
¦ Significant, long-term impacts
from additional increases in
pollutant loadings to Pacific
Ocean via the SBOO (see Section
5 for potential mitigation
measures); expected to be
consistent with the California
Ocean Plan
¦ Substantial beneficial reductions
in pollutant loadings to Pacific
Ocean via SAB Creek and Tijuana
River Estuary
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4.3 Floodplains
4.3.1 Standards of Significance
Impacts to floodplains would be significant if they were to include any of the following:
• Permanent obstruction or redirection of floodwaters.
• Development of structures in a floodway that are for human habitation.
• Increase in surface water elevation of the Tijuana River or increase in flood levels during
the occurrence of the base flood discharge.
4.3.2 No-Action Alternative
The No-Action Alternative would have no impacts to floodplains, floodways, or flood control
structures. Existing operations at the ITP would continue to occur outside the 100-year floodplain
and regulatory floodway.
4.3.3 Alternative 1: Core Projects
Under Alternative 1, construction and implementation of the Core Projects would include
installation of permanent aboveground features (e.g., wastewater treatment process infrastructure,
administrative buildings, and parking areas) in the 500-year floodplain and in areas outside the
500-year floodplain (Zone X, Area of Minimal Flood Hazard). All construction would take place
outside of the Tijuana River levee system, which protects the ITP infrastructure from a 333-year
flood event at the south levee and has greater than 3 feet of freeboard. No permanent features
would be installed or erected in the 100-year floodplain, other than a short segment of the
underground conveyance line along Monument Road near Clearwater Way under Project B (Tijuana
Canyon Flows to ITP), Options B1 and B2. Installation of this conveyance line is not expected to
alter elevations or change gradients and therefore no impacts to the 100-year floodplain are
expected. Alternative 1 would have no other short- or long-term impacts to mapped floodplains or
existing flood control structures (i.e., the north and south levees) and would not result in
significant impacts to floodplains per the criteria in Section 4.3.1 (Standards of Significance).
Alternative 1 would result in no permanent transboundary impacts to floodplains since effects from
projects in Mexico would not extend into the floodplain in the U.S. (other than reduction of
transboundary river flows, which would not affect flood events) and effects from projects in the U.S.
would not extend to floodplains in Mexico.
4.3.4 Alternative 2: Core and Supplemental Projects
Under Alternative 2, construction and implementation of the Core Projects would result in the same
impacts to floodplains as would occur under Alternative 1. Under Alternative 2, implementation of
the Supplemental Projects would include installation of permanent aboveground features (e.g.,
wastewater treatment process infrastructure, a diversion system, and trash boom[s]) and
construction and staging activities in the following FEMA floodplain zones: 100-year floodplain
(Zone AE, 1 Percent Annual Chance Flood Hazard), 500-year floodplain (Zone X, 0.2 Percent Annual
Chance Flood Hazard), and areas outside the 500-year floodplain (Zone X, Area of Minimal Flood
Hazard). Alternative 2 would not result in significant impacts to floodplains per the criteria in
Section 4.3.1 (Standards of Significance). Permanent features installed for Projects E and I would be
located outside of the Tijuana River levee system which protects the ITP infrastructure from a 333-
year flood event at the south levee and has greater than 3 feet of freeboard. Alternative 2 would
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result in no permanent transboundary impacts to floodplains since effects from projects in Mexico
would not extend into the floodplain in the U.S. (other than reduction of transboundary river flows,
which would not affect flood events) and effects from projects in the U.S. would not extend to
floodplains in Mexico.
Supplemental Projects F (U.S.-side River Diversion to APTP) and J (Trash Boom[s]) would require
temporary construction activities in the regulatory floodway within the existing levee system but
these construction activities would not take place during flood events. Project F would require the
installation of screw pumps and a conveyance line from the river diversion to the new APTP.
Although these installations would cross the south levee, impacts to the levee would be temporary
and construction would be completed during the dry season to avoid flood events. The levee would
be returned to existing conditions after the diversion system was installed. These projects are
subject to the requirements of EO 11988, Floodplain Management (42 FR 26951) (see Section 6.1.4
[Floodplains] for more information).
Projects F and J would require permanent development in the 100-year floodplain and regulatory
floodway but would be designed consistent with the County of San Diego Flood Damage Prevention
Ordinance and any other applicable requirements and guidelines for construction in a regulatory
floodway. The U.S.-side river diversion under Project F would not operate during flood events
(shutting off at a river flow rate of either 60 MGD or 120 MGD, depending on the design capacity)
and would not be expected to raise the surface water elevation or increase flood levels during the
occurrence of the base flood discharge. This would be further evaluated in a subsequent tiered
NEPA analysis. During operation, Project J would have potential upstream impacts to the 100-year
floodplain and the regulatory floodway by impeding trash and debris flow during storm events; a
pilot study and further hydrologic modeling may be necessary to assess this potential impact in
support of a subsequent tiered NEPA analysis. Trash processing areas for Project J, if necessary,
would potentially be located within the 100-year floodplain and within the regulatory floodway but
would be maintained in accordance with a trash management plan so as not to result in unintended
releases of processed trash during flood events.
Maintenance for Projects F and J would potentially require workers to be present in the floodway
during or after storm events (e.g., to resolve trash or sediment buildup at the influent screens or
wet well and in the trash boom[s]). Incorporation of remote assessment tools would reduce the
need for onsite human inspections in the floodway and the associated safety hazards.
4.3.5 Comparative Analysis of the Alternatives
Table 4-16 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
None of the evaluated alternatives would result in significant impacts to floodplains per the criteria
in Section 4.3.1 (Standards of Significance). Section 5 (Mitigation Measures and Performance
Monitoring) identifies the mitigation measures that would be implemented for the Core Projects
and provides recommended mitigation measures for the Supplemental Projects (which would be
further refined and developed in subsequent tiered NEPA analyses).
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Table 4-16. Comparative Analysis of Effects - Floodplains
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Minor, short-term impacts from
construction and staging activities
in 100- and 500-year floodplain and
in areas outside the 500-year
floodplain
Same as Alternative 1, plus the
following:
¦ Minor, short-term impacts from
construction activities in the
regulatory floodway
¦ Minor, short-term impact on flood
control structures (i.e., the south
levee) from construction activities
Permanent
effects
¦ None
¦ Installation of permanent
aboveground features in the 500-
year floodplain (outside the levee
system, which provides 3 feet of
freeboard) and in areas outside the
500-year floodplain
Same as Alternative 1, plus the
following:
¦ Additional permanent development in
the 100-year floodplain and regulatory
floodway for Projects F and J
¦ Minor, recurring impacts from trash
boom obstruction of trash and debris
flow during storm events
¦ Minor, recurring impacts from
maintenance work for Projects F and J
in the floodway during or after storm
events
4.4 Inland Biological Resources
4.4.1 Standards of Significance
Impacts to inland biological resources would be significant if they were to include any of the
following:
• Substantial disturbances to a special-status species either through direct mortality or
damage or substantial loss or degradation of their habitat.
• Substantial disruption of nesting migratory birds (e.g., nest disturbance, noise,
grading/clearing) during the breeding season.
• Removal, destruction, fragmentation, or degradation of environmentally sensitive habitats
(defined here as wetlands, including vernal pools, riparian areas, sensitive natural
communities, or MHPA lands).
4.4.2 No-Action Alternative
The No-Action Alternative would include the continuation of existing impacts to inland biological
resources that currently result from contaminated transboundary flows from Tijuana (see Section
1.3 [Causes and Impacts of Contaminated Transboundary Flows from Tijuana] and Section 3.4
[Inland Biological Resources]).
The No-Action Alternative would have no effects on special-status plant species that occur outside
of riparian habitats (i.e., outside of those areas that are currently subject to contaminated
transboundary flows). Contaminated transboundary flows in the Tijuana River would continue to
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lower the quality of the riparian habitats and adjacent upland habitats in these areas and
downstream. The No-Action Alternative would include the continuation of trash accumulation in
the Tijuana River Valley and Estuary. Trash accumulation presents concerns because it can expose
wildlife to toxic substances and increase ponding opportunities, which can encourage spread of
disease vectors. These impacts would persist unabated and would worsen over time as wastewater
infrastructure in Tijuana continues to deteriorate resulting in potential impacts on federally listed
wildlife species using riparian habitats and marsh and estuary habitats downstream of the project
areas (e.g., light-footed Ridgway's rail, snowy plover, least tern, Belding's savannah sparrow, and
tricolored blackbird).
4.4.3 Alternative 1: Core Projects
Temporary Effects
Under Alternative 1, short-term impacts from construction activities for implementation of the Core
Projects would occur within the footprint of the existing ITP parcel, along Monument Road, and
within Smuggler's Gulch. The vegetated areas within the ITP parcel are highly disturbed through
routine maintenance (i.e., mowing) and degraded with non-native plant species, which limits the
habitat value for wildlife. However, there is still potential for special-status species to be disturbed
during construction. Mitigation measures would be implemented to avoid or reduce potential
negative effects and thus the Core Projects would not result in significant impacts to inland
biological resources per the criteria in Section 4.4.1 (Standards of Significance).
A full list of recommended best practices and potential mitigation measures is provided in Section 5
(Mitigation Measures and Performance Monitoring). Prior to implementation of Alternative 1,
USIBWC would coordinate with CDFW if new information (e.g., protocol-level or preconstruction
surveys) reveals that the project would potentially result in take of state-listed species protected
under CESA.
Botanical Resources
Implementation of Projects A (Expanded ITP), B (Tijuana Canyon Flows to ITP), and D (APTP Phase
1) would include construction within the ITP parcel. Within the ITP parcel, there is potential for
some special-status plant species to occur. Some species have been documented within the ITP
parcel (i.e., Corethrogyne filaginifolia var. incana, Nemacaulis denudata var. gracilis, and
Sphaerocarpos drewiae] or adjacent to the ITP parcel (i.e., Ferocactus viridescens, Iva hayesiana, and
Viguiera laciniatci) (Table 3-5). Moreover, one sensitive natural community, Lemonade berry scrub,
has been documented within the project area (Table 3-4). Therefore, if no mitigation were
implemented, construction for Projects A, B, and D would potentially result in short-term
disturbances of special-status plant species or sensitive natural communities, either through direct
mortality or through damage or indirect damage caused by degrading special-status plant or
sensitive natural community habitat
Implementation of the Core Projects would include protocol-level surveys for special-status plant
species and sensitive natural communities that have the potential to occur in the evaluated area
(Mitigation Measure BR-26). For special-status species or sensitive natural communities
documented during the protocol-level surveys, Mitigation Measure BR-27 (establish a no-work
buffer) would be implemented, if feasible, to avoid loss of identified special-status plant species or
sensitive natural communities. If the special-status plant or sensitive natural community cannot be
avoided, a mitigation and monitoring plan would be developed in coordination with USFWS and
CDFW (Mitigation Measure BR-28). Therefore, with implementation of mitigation, construction for
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Core Projects would not result in short-term substantial disturbances of special-status plant
species.
Construction activities in Mexico would have no transboundary impact on botanical resources in
the U.S. since any potential impacts would be limited to the area of construction in Mexico.
Wildlife Resources
Construction activities for Projects A (Expanded ITP), B (Tijuana Canyon Flows to ITP), and D
(APTP Phase 1) would potentially result in short-term disturbances of special-status wildlife
species if no mitigation were implemented. Short-term disturbances could result from interference
with foraging/feeding behavior, interference with migration and reproduction, direct injury or
mortality, and/or damage or indirect damage by degrading suitable habitat, as discussed below.
Construction for Projects A and D would potentially affect San Diego fairy shrimp, if present, if
construction activities or staging areas were sited on an occupied vernal pool, even if dry (dry
occupied vernal pools contain cyst banks for the species). Focused vernal pool surveys have not
been conducted for the Proposed Action, and San Diego fairy shrimp may inhabit shallow and
relatively temporary vernal pools. There is a small chance that small vernal pools may occur in the
ITP where suitable clay or poor draining soils are found. However, San Diego fairy shrimp do not
likely occur in the project areas as no evidence of vernal pools or vernal pool complexes has been
identified to date, and field observations suggest there is a low probability that vernal pools occur
within the ITP. Surveys for vernal pool habitat would be conducted prior to project construction
(Mitigation Measure BR-13) and subsequently during final siting. If found, vernal pools would be
avoided. If vernal pools cannot be completely avoided and protocol-level surveys detect the
presence of San Diego fairy shrimp in vernal pools located on the ITP parcel, or within disturbance
areas, ESA Section 7 consultation with USFWS would be reinitiated, and a mitigation and
monitoring plan would be developed. Therefore, with implementation of mitigation (avoidance),
the Core Projects would not result in short-term substantial disturbances of San Diego fairy shrimp.
Construction for Projects A and D would potentially affect Quino checkerspot butterflies if no
mitigation were implemented by resulting in any of the following: loss of (e.g., removal), reduction
in, or damage to (e.g., disturbance to roots or limbs) occupied host plants; disruption of essential
behaviors (e.g., feeding, pupation, diapause periods); crushing, killing, or injuring individual eggs,
pre- or post-diapause larvae, or butterflies; or production of excessive dust that would impact
respiration by the adults or cover the eggs and larvae, leading to death by smothering or reducing
their lifecycle. However, Quino checkerspot butterflies have a relatively low potential to occur in
the vicinity of construction activities due to marginally suitable habitat. Primary host plants may
occur in small numbers in the proposed staging area between Dairy Mart Road and Clearwater
Way, or could become established in relatively small, fragmented areas within the ITP where
Project A or Project D may be implemented. Mitigation Measures BR-14, BR-15, and BR-20 include
focused surveys for Quino checkerspot butterfly primary host plants (regardless of occupation by
species) by a qualified biologist during the appropriate bloom time (to ensure host plants are
correctly identified); flagging for avoidance (if found); and fugitive dust prevention during
construction activities. If host plants were found during focused surveys, they would be flagged and
avoided to ensure that no suitable habitat for the species would be disturbed or impacted.
Additionally, Mitigation Measures BR-11, BR-17, and BR-18 (worker environmental awareness
training, equipment checks, and allowing animals to leave the area of their own volition) would
further reduce potential impacts to dispersing adult Quino checkerspot butterflies. Therefore, with
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implementation of mitigation, the Core Projects would not result in short-term substantial
disturbances of Quino checkerspot butterflies.
Construction activities for Projects A, B, and D would potentially affect special-status reptiles if no
mitigation were implemented. Specifically, construction activities would potentially affect coast
horned lizards, southern California legless lizards, and/or Baja California coachwhips, all of which
may occur in Smuggler's Gulch, and to a lesser extent in the ITP, as the ITP is marginally suitable for
these species. Temporary disturbances would occur if special-status reptiles were to enter the
project areas during construction activities. Potential direct effects include disruption of behavior
and movement caused by visual disturbance, noise/vibration from equipment, and/or general
presence of humans. Direct effects would potentially include injury or mortality of individuals
resulting from entrapment or collisions with construction vehicles or equipment and/or
entrapment in steep-sided excavations. Potential for injury or mortality is low as reptiles typically
flee to avoid people, and the areas within the construction footprint have limited suitable habitat In
addition, suitable coastal scrub habitat in Smuggler's Gulch would not be directly removed as part
of the construction of any of the options under Project B. Measures to avoid or minimize direct
effects on reptiles include worker environmental awareness training, targeted preconstruction
surveys, speed limits, letting wildlife move from the work area on their own, prohibiting use of
monofilament netting and instead using tightly woven fiber netting or similar material for erosion
control, and covering or installing a ramp for steep-sided excavations (Mitigation Measures BR-11,
BR-12, BR-16, BR-17, BR-18, BR-20, and BR-21). Indirect impacts from habitat removal would not
be expected, as no core habitat for special-status reptiles would be removed as part of the Core
Projects. Therefore, with implementation of mitigation, the Core Projects would not result in short-
term effects on special-status reptiles.
Construction for Projects A, B, and D would potentially result in short-term disturbances of nesting
birds if construction activities were to occur during the breeding seasons and if no mitigation were
implemented. Construction for Project B would occur in the vicinity of special-status bird species
that may nest in the coastal sage scrub on the slopes associated with Smuggler's Gulch (i.e.,
California coastal gnatcatcher). Construction activities for Project B, Options B1 (Trenching via
Smuggler's Gulch and Monument Road) and B2 (Trenchless via Smuggler's Gulch and Under Mesa),
would also occur in the vicinity of special-status bird species that may nest in the small riparian
area within Smuggler's Gulch (i.e., white-tailed kite, least Bell's vireo, yellow warbler, and/or
yellow-breasted chat). Other migratory birds may nest within, or in the vicinity of, the ITP.
Proposed construction activities would be unlikely to affect special-status birds that may only use
the area for foraging (e.g., Swainson's hawk, American peregrine falcon, and southwestern willow
flycatcher), as foraging birds can easily disperse away from project-related disturbance. Potential
short-term effects on nesting special-status or other migratory birds include the disturbance (e.g.,
harassment) of an individual and actions that could lead to the abandonment or failure of a nest
(e.g., damage to the nest and/or the vegetation containing the nest). Noise and vibration associated
with the use of heavy equipment during construction may lead to effects by disrupting or masking
intraspecific communication and/or startling birds nesting in adjacent habitat Continued
disturbance from construction noise could result in displacement, nest abandonment, and/or
reproductive loss. Displaced birds could have increased risk of predation, death, or injury, or could
be unable to find nearby suitable and/or available nesting habitat (i.e., habitat that does not overlap
with the nesting territories of other birds). In addition, an increase in fugitive dust from
construction activities could temporarily degrade surrounding suitable nesting habitat
Implementation of preconstruction nest surveys for nesting birds, including special-status species
(e.g., least Bell's vireo, California coastal gnatcatcher, white-tailed kite, yellow warbler, and yellow-
breasted chat) (Mitigation Measure BR-23), would ensure that any active nest found would be given
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an appropriate no-disturbance buffer to prevent disturbance or abandonment resulting from
construction activities. Additionally, Mitigation Measures BR-11, BR-18, and BR-20 (worker
environmental awareness training, letting wildlife move from the work area on their own, speed
limits) would further reduce short-term effects on nesting special-status or migratory birds.
There are no anticipated indirect effects on any special-status birds from the loss or reduction of
preferred habitat and/or food sources, as suitable riparian or coastal sage scrub habitats are not
proposed for removal or alteration. Open-cut trenching for Project B would be confined to the
existing roadway in Smuggler's Gulch and along Monument Road, as well as the undeveloped strip
of land adjacent to Clearwater Way and WestTia Juana Street. These areas do not provide any high-
value nesting habitat for special-status birds. Therefore, with implementation of mitigation, the
Core Projects would not result in short-term effects on special-status or other migratory nesting
birds.
Construction for Projects A, B, and D would potentially result in short-term disturbances of
Northwestern San Diego pocket mice and San Diego black-tailed jackrabbits if they were to enter
the project areas during construction activities and if no mitigation were implemented.
Northwestern San Diego pocket mice and San Diego black-tailed jackrabbit may occur in Smuggler's
Gulch, and to a lesser extent in the ITP. Potential effects include disruption of behavior and
movement caused by visual disturbance, noise/vibration from equipment, or general presence of
humans. Direct effects would potentially include injury or mortality of individuals resulting from
entrapment or collisions with construction vehicles or equipment and/or entrapment in steep-
sided excavations. Potential for injury or mortality is low as these mammals typically flee to avoid
people and equipment, and the construction areas have limited suitable habitat. In addition,
suitable coastal scrub habitat in Smuggler's Gulch would not be directly removed as part of the
construction of any of the options under Project B. Measures to avoid or minimize direct impacts on
mammals include worker environmental awareness training, targeted preconstruction surveys,
speed limits, letting wildlife move from the work area on their own, prohibiting use of
monofilament netting and instead using tightly woven fiber netting or similar material for erosion
control, and covering or installing a ramp for steep-sided excavations (Mitigation Measures BR-11,
BR-12, BR-16, BR-17, BR-18, BR-20, and BR-21). Therefore, with implementation of mitigation, the
Core Projects would not result in short-term effects on special-status mammals.
The Core Projects would not result in short-term effects on special-status amphibians, as there is no
potential for occurrence in the area affected by the Core Projects. Construction activities in Mexico
would not be expected to affect wildlife resources in the U.S. since any potential impacts would be
limited to the area of construction in Mexico.
Inland Fish Resources
Construction activities for Core Projects would occur in areas that provide no habitat for special-
status fish species. Construction activities for Core Projects would potentially result in temporary
effects on special-status fish, such as sediment runoff and hydrocarbon contamination of aquatic
habitats. Increased sediment inputs into the Tijuana River would coincide with rain events during
or following construction activities that disturb soils. Hydrocarbon contamination could result from
leaking fuel or hydraulic lines on heavy equipment, improper fuel handling practices, or spills
during refueling or lubrication operations. Specifically, Projects A (Expanded ITP) and D (APTP
Phase 1) would involve construction activities within the existing ITP parcel that is adjacent to the
Tijuana River. Project B (Tijuana Canyon Flows to ITP), Option B1 (Trenching via Smuggler's Gulch
and Monument Road), would have the largest potential impacts due to aboveground effects from
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the use of trenching that would result in the disturbance to soils and the largest potential for
sediment runoff. Implementation of Options B2 (Trenchless via Smuggler's Gulch and Under Mesa)
and B3 (Connect to Existing Canyon Collector System) would reduce potential impacts from
sediment runoff by using trenchless methods. All Core Projects could result in hydrocarbon
contamination associated with construction operations.
Increased sediment runoff and hydrocarbon contamination would predominantly occur during
wet-season rain events, which coincide with the potential presence of migrating special-status
species (i.e., steelhead and Pacific lamprey). However, elevated concentrations of sediment and
contaminants already occur during high flow events from natural and non-natural processes within
the watershed, and it is unlikely that additional inputs from construction would result in large
proportional increases such that concentrations would increase beyond biological tolerance
thresholds for special-status fish. The potential effects of increased sediment runoff and
hydrocarbon contamination on special-status fish would be minimized through implementation of
Mitigation Measures BR-29 and BR-30 (erosion reduction measures and hydrocarbon
contamination BMPs), respectively. With implementation of mitigation, the Core Projects would not
result in short-term substantial disturbances of on special-status fish species.
Construction activities in Mexico would not be expected to affect inland fish resources in the U.S.
since any potential impacts would be limited to the area of construction in Mexico.
Permanent Effects
Under Alternative 1, implementation of the Core Projects would provide long-term water quality
benefits that could potentially improve conditions for inland biological resources in downstream
areas in the Tijuana River and Estuary. The Core Projects would result in minor reductions in
sediment loads and incidental trash removal but would not substantially change sediment or trash
volumes in the Tijuana River Valley and Estuary. These water quality improvements described in
Section 4.1 (Freshwater and Estuarine Resources) would likely have beneficial permanent effects
on inland biological resources. Implementation of the Core Projects would not result in significant
impacts to inland biological resources per the criteria in Section 4.4.1 (Standards of Significance).
Through coordination with USFWS, EPA prepared and submitted a Biological Assessment to
determine whether this project would be likely to result in adverse effects on species protected
under the ESA. In accordance with ESA Section 7, EPA requested USFWS concurrence with a may
affect but is not likely to adversely affect determination for the species specified in the Biological
Assessment and for least Bell's vireo critical habitat Based on continued informal consultation with
USFWS, it is possible that USFWS may identify additional conservation measures necessary to
ensure that reductions in freshwater river flows under the Core Projects would not result in a net
loss of downstream riparian habitat for the least Bell's vireo (Mitigation Measure BR-25). See
Sections 6.1.5 (Inland Biological Resources) and 7.2.1 (Endangered Species Act Section 7
Consultation) and Appendix D (USFWS Biological Assessment) for more information.
Prior to implementation of Alternative 1, USIBWC would coordinate with CDFW if new information
(e.g., protocol-level or preconstruction surveys) reveals that the project would potentially result in
take of state-listed species protected under CESA.
Botanical Resources
As indicated in Section 4.1 (Freshwater and Estuarine Resources), transboundary river flow
conditions after Core Project implementation would be expected to be generally consistent, in
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terms of frequency and volume, with historical conditions since 2000 (excepting the 2017 and 2020
rainfall years, which had unusually frequent dry-weather transboundary flows). Therefore, any
changes to surface water and groundwater interactions as a result of the implementation of the
Core Projects would not substantially disturb special-status plant species that are associated with
riparian habitat: Artemisia palmeri, Juglans californica, Lilium humboldtii subsp. ocellatum,
Monardella stoneana, and Monardella viminea. Moreover, water quality improvements from
implementation of Core Projects would likely have long-term beneficial effects on those same
species.
No other components of Core Projects would result in long-term effects on botanical resources in
the U.S.
Wildlife Resources
Implementation of the Core Projects would improve downstream water quality, thus reducing
wildlife exposure to toxic substances and ponding that can encourage spread of disease vectors.
This would likely provide associated long-term benefits to special-status wildlife species using the
Tijuana River Estuary downstream of the project areas (e.g., light-footed Ridgway's rail, Belding's
savannah sparrow, and tricolored blackbird). As indicated above (see Botanical Resources) and in
Section 4.1 (Freshwater and Estuarine Resources), transboundary river flow conditions after Core
Project implementation would be expected to be generally consistent, in terms of frequency and
volume, with historical conditions since 2000 (excepting the 2017 and 2020 rainfall years, which
had unusually frequent dry-weather transboundary flows). Therefore, any changes to surface water
and groundwater interactions as a result of the implementation of the Core Project would not result
in long-term substantial disturbances of special-status plant species that are associated with
riparian habitat and thus would not result in substantial long-term disturbances of special-status
wildlife species that are using associated downstream riparian habitats (e.g., least Bell's vireo, light-
footed Ridgway's rail, Belding's savannah sparrow, and tricolored blackbird).
No other components of Core Projects would result in long-term effects on wildlife resources in the
U.S.
Inland Fish Resources
Contaminated transboundary flows are likely a critical limiting factor for special-status fish species
in the Tijuana River and the Tijuana River Estuary. Thus, water quality improvements associated
with implementation of Core Projects would likely improve conditions for special-status fish in
downstream areas of the Tijuana River and Estuary.
Specifically, Projects C (Tijuana Sewer Repairs) and D (APTP Phase 1) would be the only Core
Projects that affect transboundary river flows by reducing contaminated dry-weather flows. Under
existing conditions, dry weather flows are likely elevated above natural levels from urban runoff
and wastewater discharge. Furthermore, special-status fish species are not expected to be present
in the Tijuana River downstream of the U.S.-Mexico border during the dry season. Therefore, any
reduction in transboundary flows during the dry season would not result in long-term disturbances
of special-status fish species in the Tijuana River downstream of the U.S.-Mexico border and would
potentially improve conditions in the estuary due to reduced input of contaminated flows.
Implementation of the Core Projects would not affect wet-weather transboundary river flows
(other than through the reduction of untreated wastewater in the river under Project C) and thus
would not decrease migration opportunities for special-status fish species. Because of the shutoff
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protocols for the PB-CILA river diversion under Project D, implementation of the Core Projects
would not mitigate impacts to the river or estuary from extreme weather events.
Due to the reduction in transboundary flows largely occurring during dry-season, when special
status fish are not reliant on flows in the Tijuana River, implementation of Core Projects would not
result in long-term effects on special-status fish species.
No other components of Core Projects would result in long-term effects on inland fish resources in
the U.S.
4.4.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Under Alternative 2, implementation of the Core Projects would result in the same short-term
impacts to inland biological resources as would occur under Alternative 1.
Implementation of Supplemental Projects in the U.S. would include short-term construction
activities within the same locations used for Core Projects, in addition to construction activities in
the Tijuana River main channel and floodplain for Projects F (U.S.-side River Diversion to APTP)
and J (Trash Boom[s]). Construction in the Tijuana River main channel and floodplain would
potentially result in short-term substantial disturbances of special-status species or sensitive
natural communities (in addition to those identified for Alternative 1) if no mitigation were
implemented. These effects would be further defined and analyzed in subsequent tiered NEPA
analyses, and USIBWC would coordinate with CDFW if new information (e.g., protocol-level or
preconstruction surveys) reveals that Alternative 2 would potentially result in take of state-listed
species protected under CESA. Construction activities in Mexico would not result in transboundary
effects on inland biological resources in the U.S. Mitigation measures would be implemented to
avoid or reduce potential negative effects and thus the Supplemental Projects would not result in
significant impacts to inland biological resources per the criteria in Section 4.4.1 (Standards of
Significance).
Botanical Resources
Implementation of Projects F (U.S.-side River Diversion to APTP) and J (Trash Boom[s]) would
include construction activities in the Tijuana River main channel, where there would be potential
for some special-status plant species to occur (see Appendix E [Database Query Results for Special-
status Species and Sensitive Natural Communities]). Some species have been documented within
the main channel (i.e., Heterotheca sessiliflora subsp. sessiliflora and Iva hayesianci) or adjacent to
the main channel [i.e., Ambrosia monogyrci) (Table 3-5). Moreover, one sensitive natural
community, Gooding's willow-red willow Riparian Woodland and Forest, has been documented
within the Supplemental Project area (Table 3-4). Therefore, construction of the U.S.-side river
diversion and trash boom(s) would potentially result in substantial disturbances of special-status
plant species or sensitive natural communities, either through direct mortality or damage or
through indirect damage caused by degradation of special-status plant or sensitive natural
community habitat. Potential effects and the need for mitigation would be dependent on the
location of the proposed river diversion and trash boom(s), which would be further defined and
analyzed in subsequent tiered NEPA analyses.
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Protocol-level surveys would be conducted for special-status plant species and sensitive natural
communities that have the potential to occur in construction areas (Mitigation Measure BR-26). For
special-status species or sensitive natural communities documented during protocol-level surveys,
Mitigation Measure BR-27 (establish a no-work buffer) would be implemented, if feasible, to avoid
loss of identified special-status plant species or sensitive natural communities. If the special-status
plants cannot be avoided, a mitigation and monitoring plan would be developed in coordination
with USFWS and CDFW (Mitigation Measure BR-28). Therefore, with implementation of mitigation,
Supplemental Projects would not result in short-term substantial disturbances of special-status
plant species.
Wildlife Resources
Construction activities in the Tijuana River main channel for Projects F (U.S.-side River Diversion to
APTP) and J (Trash Boom[s]) would be expected to have few, if any, short-term effects on special-
status wildlife species. Habitat value along the Tijuana River upstream of Dairy Mart Road is
marginally suitable and limited for special-status wildlife species, as riparian vegetation along this
section of the Tijuana River is regularly managed (e.g., by mowing, discing, cutting) to maintain a
line-of-sight for CBP agents and reduce hiding opportunities within the Tijuana River Floodway
(CBP, 2017). Therefore, there would be low potential for short-term substantial disturbances of
wildlife resources. Potential effects and the need for mitigation would be dependent on the location
of the proposed river diversion and trash boom(s), which would be further defined and analyzed in
subsequent tiered NEPA analyses.
Inland Fish Resources
Construction activities in the Tijuana River main channel for Projects F (U.S.-side River Diversion to
APTP) and J (Trash Boom[s]) would potentially result in short-term disturbances of special-status
fish by altering flows and channel morphology, as well as through increases in sediment and
hydrocarbon inputs into the Tijuana River and Estuary. Increased sediment and hydrocarbon
inputs would result in the same short-term effects on special-status fish as described for
construction activities in Alternative 1. These effects could be similarly mitigated using Mitigation
Measures BR-29 and BR-30 (erosion reduction measures and hydrocarbon contamination BMPs).
Altered flows and channel morphology during construction would potentially result in short-term
substantial disturbances of migration of special-status fish if passage were not provided during
construction activities that coincided with migration season, which extends from approximately
December to July for steelhead and Pacific lamprey. These effects on migration would be mitigated
through implementation of Mitigation Measure BR-31 (limiting in-water work to the dry-season).
Potential effects and the need for mitigation would be dependent on the location of the proposed
river diversion and trash boom(s), which would be further defined and analyzed in subsequent
tiered NEPA analyses.
Permanent Effects
Under Alternative 2, implementation of the Core Projects would result in the same long-term
impacts to inland biological resources as would occur under Alternative 1. Operational effects of the
Supplemental Projects, including additional transboundary water quality improvements and
additional reductions in contaminated transboundary flows, would result in additional benefits to
special-status species. However, by decreasing the cumulative volume of transboundary flows in
the Tijuana River, the Supplemental Projects would potentially result in at least one of the
significant impacts to inland biological resources per the criteria in Section 4.4.1 (Standards of
Significance). Potential effects and the need for mitigation would be further defined and analyzed in
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subsequent tiered NEPA analyses, and USIBWC would coordinate with CDFW if new information
(e.g., protocol-level or preconstruction surveys) reveals that Alternative 2 would potentially result
in take of state-listed species protected under CESA..
Botanical Resources
Implementation of the Supplemental Projects would further decrease the cumulative volume of
transboundary flows in the river, particularly during smaller wet-weather events as described in
Section 4.1 (Freshwater and Estuarine Resources). Additional decreases in contaminated
transboundary flows would potentially result in permanent benefits to special-status plant species
through reduced contaminants. Reductions in trash, resulting from implementation of Project J
(Trash Boom[s]), could also result in long-term benefits to special-status plant species.
Implementation of Projects F (U.S.-side River Diversion to APTP) and H (Tijuana WWTP Treated
Effluent Reuse) would result in a reduction in transboundary river flows. Reductions in
transboundary river flows would potentially result in long-term substantial disturbances of special-
status plant species that are associated with riparian habitat (i.e., Artemisia palmeri, Juglans
californica, Lilium humboldtii subsp. ocellatum, Monardella stoneana, and Monardella vimineci)
resulting in a potentially significant impact. In addition, changes in transboundary flows could
impact the physical, chemical, and biological properties in the Tijuana River Estuary, which could
affect special-status plant species in the estuary. These potential effects and the need for mitigation
would be analyzed in further detail in subsequent tiered NEPA analyses.
Wildlife Resources
Implementation of the Supplemental Projects would further decrease the cumulative volume of
transboundary flows in the river, particularly during smaller wet-weather events as described in
Section 4.1 (Freshwater and Estuarine Resources). Additional decreases in contaminated
transboundary flows would potentially result in long-term benefits to special-status wildlife species
through reduced exposure to contaminants and disease vectors. Reductions in trash and debris,
resulting from implementation of Project J (Trash Boom[s]), would also result in permanent
benefits to special-status wildlife species by limiting exposure to harmful debris and/or limiting
potential buildup leading to ponding water that promotes disease vectors. Operation of Projects F
(U.S.-side River Diversion to APTP) and J would result in a reduction in transboundary flows. These
changes in flows would potentially result in long-term substantial disturbances of special-status
wildlife species that may occur in downstream river or estuarine habitats (e.g., least Bell's vireo,
light-footed Ridgway's rail, Belding's savannah sparrow, and tricolored blackbird) resulting in a
significant impact. These potential effects and the need for mitigation would be analyzed in further
detail in subsequent tiered NEPA analyses.
Inland Fish Resources
Implementation of the Supplemental Projects would further decrease the cumulative volume of
transboundary flows in the river, particularly during smaller wet-weather events as described in
Section 4.1 (Freshwater and Estuarine Resources). Additional decreases in contaminated
transboundary flows would potentially result in long-term benefits to special-status fish species
through reduced exposure to contaminants. Reductions in trash, resulting from implementation of
Project J (Trash Boom[s]), would also potentially result in long-term benefits to special-status fish
species.
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Implementation of Projects F (U.S.-side River Diversion to APTP) and H (Tijuana WWTP Treated
Effluent Reuse) would result in a reduction in transboundary river flows, which could potentially
affect the ability of special-status fish to migrate in the Tijuana River. Reduced flows could have the
effect of reducing the frequency of migration opportunities (e.g., there could be fewer sandbar-
breaching events that provide connectivity with the ocean). Reduced flows could also limit passage
due to the formation of riffles that lack sufficient water depth for passage. In addition, changes in
transboundary flows would potentially impact the physical, chemical, and biological properties in
the Tijuana River Estuary, which would potentially substantially disturb steelhead individuals with
a lagoon rearing life history type if steelhead with this life history type occurred in the watershed
resulting in a significant impact. However, implementation of the Supplemental Projects would not
affect larger wet-weather transboundary river flow events when migration of special-status fish is
expected. Potential effects and the need for mitigation would be analyzed in further detail in
subsequent tiered NEPA analyses.
4.4.5 Comparative Analysis of the Alternatives
Table 4-17 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
One of the evaluated alternatives would potentially result in significant impacts to inland biological
resources per the criteria in Section 4.4.1 (Standards of Significance). Section 5 (Mitigation
Measures and Performance Monitoring) identifies the mitigation measures that would be
implemented for the Core Projects and provides recommended mitigation measures for the
Supplemental Projects (which would be further refined and developed in subsequent tiered NEPA
analyses).
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Table 4-17. Comparative Analysis of Effects - Inland Biological Resources
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ No short-term substantial
disturbances of special-status
species, migratory birds, or
environmentally sensitive habitats
during construction in the ITP
parcel, Smuggler's Gulch, and along
Monument Road with
implementation of mitigation
¦ No short-term substantial
disturbance of San Diego fairy
shrimp with implementation of
mitigation
¦ No short-term substantial
disturbance of Quino checkerspot
butterfly with implementation of
mitigation
Same as Alternative 1, plus the
following:
¦ Potential short-term substantial
disturbances of special-status wildlife
and fish species during construction in
the Tijuana River main channel and
floodplain depending on the location
of the proposed river diversion and
trash boom(s) (see Section 5 for
potential mitigation measures)
Permanent
effects
¦ Continuation
of negative
effects on
inland
biological
resources
resulting from
contaminated
transboundary
flows
¦ Potential long-term beneficial
effects on inland biological
resources due to improved water
quality
¦ No long-term substantial
disturbances of special-status plant
and wildlife species associated with
downstream riparian habitat
(pending continued consultation
with USFWS)
¦ EPA and USIBWC anticipate
conclusion of ESA Section 7
informal consultation with USFWS
concurrence with the may affect
but is not likely to adversely affect
determination
Same as Alternative 1, plus the
following:
¦ Potential significant, long-term
substantial disturbances of special-
status plant and wildlife species
associated with downstream riparian
habitat due to reduced wet-weather
transboundary flows (see Section 5
for potential mitigation measures)
¦ Potential significant, long-term
substantial disturbances from
reduction in special-status fish
migration ability and/or degradation
of estuarine rearing conditions due to
reduced wet-weather transboundary
flows (see Section 5 for potential
mitigation measures)
¦ Increase in water quality-related long-
term beneficial effect on inland
biological resources
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4.5 Marine Biological Resources
4.5.1 Standards of Significance
Impacts to marine biological resources would be significant if they were to include a substantial
disturbance58 to a species or habitat protected or conserved under federal, state, or local legislation
and regulations.
4.5.2 No-Action Alternative
Under the No-Action Alternative, the ITP would continue discharging treated effluent via the SBOO
at a level similar to current practices, and the marine habitat conditions described in Section 3.5
(Marine Biological Resources) would, at first, remain similar to existing conditions. However,
pollutant loadings to the Pacific Ocean via SAB Creek and via transboundary river and canyon flows
would persist unabated and would worsen over time as wastewater infrastructure in Tijuana
continues to deteriorate and the population continues to grow without access to adequate
wastewater treatment infrastructure. This would be expected to contribute to more frequent and
intense HAB events and general degradation of marine habitat.
4.5.3 Alternative 1: Core Projects
Temporary Effects
Under Alternative 1, implementation of the Core Projects would result in minor, short-term impacts
to marine biological resources from activities associated with modifications to the wye diffuser
array on the SBOO for Projects A (Expanded ITP) and D (APTP Phase 1). Currently, 18 of the 165
risers are open, with operating diffusers and ports. A further 16 risers are currently capped,
consisting of a diffuser head with four temporarily closed ports. The remaining 131 risers are blind
flanged and would require the installation of a diffuser head to be operational. To accommodate the
increase in effluent discharge volume for the Core Projects, up to 55 risers on the southern leg of
the SBOO wye diffuser would be recommissioned (e.g., by uncapping the 16 capped risers/diffusers
and installing new diffusers/ports on up to 39 blind flanged risers). This would involve physical
modifications as described below.
It is anticipated that the recommissioning of a capped/plugged or a blind-flanged diffuser port
would result in minor disturbance to marine wildlife and habitat Specifically, divers would likely
disturb or remove a relatively small area of habitat and species on and around a diffuser head that
requires modification. At each modified diffuser head, it is assumed that this may result in the
disruption of no more, and in most circumstances considerably less, than a 6-foot-by-6-foot area of
artificial reef habitat. This disturbance would be necessary to allow divers to access bolts, blind
flanges, and other parts of the diffuser ports with hand tools to make the modifications likely to be
required to recommission these features. Following completion of the diver activity, natural
58 A substantial disturbance would be a high likelihood of causing a substantial decline in the local population
of a species or extent and/or health of a habitat. 'Likelihood' is a judgment or assertion reasonably supported
by evidence, precedent, or reasoned assessment of other established information. In this context, 'substantial'
is defined as any change that could be detected over natural variability and occurs for more than six months,
while 'local' is used to define any population or habitat occurring within the Area of Interest of the Proposed
Project area and activities on a permanent or intermittent basis.
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ecological-succession processes would be highly likely to gradually replace the lost habitat over
time. During these diving activities, disturbance of sandy seafloor adjacent to the rocky reef would
not occur, as the working footprint of these diving activities would occur within the boundaries of
the ballast-rock reef. The ballast-rock reef, risers, and other SBOO structures that would be directly
contacted by these activities do not constitute EFH. While the water column above the ballast-rock
reef is EFH, these activities would not result in substantial disturbances to this habitat
Marine life may be disturbed by noise and activity during vessel use and diver activity. Diver
activity is unlikely to include activities that generate very high noise levels, such as powered cutting
or hammering. Direct disturbance of marine wildlife due to construction activities is discussed in
the NMFS Biological Assessment (Appendix F). Impacts would be highly unlikely because the
activity would occur over a relatively short period of time (a few hours each day for a few weeks),
activities would likely occur in phases over the course of several years, animals would be unlikely
to regularly occur in the immediate vicinity of the SBOO wye diffuser, and these animals would
easily move a short distance away if disturbed.
Vessel activities bring a small risk of grounding or oil spill. However, spilled fluids from a grounded
or stricken vessel can have serious environmental consequences for marine habitats and associated
species. Vessels would be likely to carry hydraulic fluids and fuel that would be toxic to marine life
if spilled. The Tijuana River Estuary and Imperial Beach Kelp Forest would be the most vulnerable
EFH to spilled oil or hydraulic fluids. Assuming mitigation measures are maintained (see Section 5
[Mitigation Measures and Performance Monitoring]), the likelihood of substantial disturbance of
EFH from oil spill or grounding is negligible.
Anchor deployment carries some risk of collision with marine mammals, sea turtles, and benthic
invertebrates and is discussed in the NMFS Biological Assessment (Appendix F) and NMFS Essential
Fish Habitat Assessment (Appendix G). However, assuming mitigation measures are applied (see
Section 5 [Mitigation Measures and Performance Monitoring]), the likelihood of an anchor striking
a protected animal would be so small that the risk of a substantial disturbance would be negligible.
Anchor deployment on sandy seafloor would potentially result in minor disturbance of seabed
communities within the immediate proximity of the anchor; however, this would occur within an
estimated area no larger than 9 square feet (SF), based on typical small-to-medium boat anchor
size. While this anchoring would disturb Groundfish EFH within this footprint, this effect is minimal
relative to available adjacent habitat and would therefore have a negligible effect on species using
this habitat and would not constitute a substantial disturbance.
Potential effects on conserved species and habitat due to recommissioning activities would be
highly unlikely to occur or unlikely to be detected over natural variability. Alternative 1 would not
result in significant impacts to marine biological resources per the criteria in Section 4.5.1
(Standards of Significance).
Permanent Effects
Under Alternative 1, implementation of the Core Projects would have long-term beneficial effects by
reducing untreated wastewater contamination in transboundary flows in the Tijuana River and in
flows that would have otherwise been discharged, untreated, to the Pacific Ocean via SAB Creek.
This would be accompanied by an increase in the discharge of primary- and secondary-treated
effluent to the ocean via the SBOO. The net reduction in pollutant loadings to marine waters is
expected to improve water quality conditions in the evaluated area and result in a net beneficial
impact on marine wildlife. Alternative 1 would not result in significant impacts to marine biological
resources per the criteria in Section 4.5.1 (Standards of Significance).
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Certain Core Projects (Projects A [Expanded ITP] and D [APTP Phase 1]) include volume scenarios
for the treatment of transboundary flows that would cumulatively result in an increase of up to
approximately 55.7 MGD of effluent being discharged from the SBOO, in addition to baseline
discharges of up to 28.8 MGD from the ITP and SBWRP combined, for a total discharge of up to 84.7
MGD.59 To assess the potential for negative effects, the magnitude of change in SBOO discharge
extent has been estimated using a mixing model. Modeling was performed with the UM3 model
from the Visual Plumes software suite (Plumesl8 edition60). Results of the plume modeling
discussed in Section 4.2 (Marine Waters) predict that an increase in volume of effluent from 35
MGD to 110 MGD61 would result in an approximate doubling in the overall modeled plume extent,
with less of an increase in the plume extent in areas closer to the SBOO where concentrations are
higher. It is important to consider that these results reflect a highly idealized comparison between
two discharge volume scenarios and are not expected to represent actual plume positions in
relation to the SBOO terminus. Rather, the results demonstrate the approximate change in
magnitude of the discharge in relation to dispersal potential.
In evaluating the Proposed Action in relation to ESA-listed species, EPA and USIBWC considered the
following potential pathways of exposure for ESA-listed species to polluted nearshore waters due
to discharge of wastewater (treated and untreated) to the Pacific Ocean arising from the Proposed
Action:
1. The direct ingestion, or indirect ingestion via prey, of chemicals toxic to the animals that
occur in the polluted discharges.
2. An increase in the likelihood of HABs, which in turn produce toxins that directly harm
animals or their prey, due to increased nutrient enrichment and other less direct ecological
consequences of reduced water quality.
In evaluating the Proposed Action in relation to EFH, EPA and USIBWC considered the following
potential pathways of EFH exposure to polluted waters due to discharge of wastewater (treated
and untreated) to the Pacific Ocean arising from the Proposed Action:
1. The presence in EFH of chemicals toxic to animals at levels sufficient to cause harm when
ingested either directly or indirectly via the consumption of prey.
59 The average daily SBOO effluent flow rate would immediately increase from approximately 28.8 MGD
under current conditions to approximately 65.1 MGD under initial operating conditions of the expanded ITP
and new 35-MGD APTP. The average daily SBOO effluent rate would then gradually increase (over the course
of the 20-year period from 2030 to 2050) to approximately 84.7 MGD by 2050 as the full capacity of the 60-
MGD expanded ITP comes into service in response to population growth in Tijuana.
60 Visual Plumes is a free outfall modeling software suite developed by EPA and currently distributed in
partnership between the SWRCB and Walter Frick, the lead software developer/maintainer. Plumesl8
edition retrieved on January 5, 2021, from:
https://www.waterboards.ca.gov/water_issues/programs/ocean/
61 As discussed in Section 4.2 (Marine Waters), the modeled scenarios represent a conservative model
construction that likely overestimates the expected changes in the SBOO effluent plume under the Core
Projects.
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2. An increase in the likelihood of HABs within EFH (which produce toxins that directly harm
animals or their prey) due to increased nutrient enrichment and other less-direct ecological
consequences of reduced water quality.
For additional information and analysis on constituents and pollutants of wastewater discharges
and their effects on marine wildlife and EFH in the evaluated area, see Appendix F (NMFS Biological
Assessment) and Appendix G (NMFS Essential Fish Habitat Assessment). The NPDES program seeks
to ensure that these pollutants will not degrade marine communities. Although discharge of treated
effluent to the ocean via the SBOO would increase, the continued discharge of untreated
wastewater from SAB Creek and through other transboundary flows into the marine environment
(if not addressed through the Proposed Action) would result in a higher loading of metals,
nutrients, BOD, TSS, and other potential pollutants in the marine environment of the evaluated
area. Therefore, the implementation of the Core Projects would result in a net decrease in the
release of pollutants to the marine environment.
As discussed in Section 4.2 (Marine Waters), implementation of Core Projects would reduce overall
nutrient loadings to the Pacific Ocean but would increase nutrient loadings discharged specifically
via the SBOO (by approximately 154 percent under initial operations and by approximately 200
percent in 2050 when compared to the no-action baseline). It is unclear whether the increase in the
SBOO discharge would increase the frequency or magnitude of HABs in the evaluated area. It is
highly probable that contributions of coastally trapped raw effluent presently discharged from SAB
Creek and the Tijuana River Estuary do contribute to an increased likelihood of HAB events. The
Core Projects seek to reduce or eliminate this polluting feature. If the enrichment of coastal waters
due to transboundary flows does result in increased frequency of HABs, there would likely be a net
reduction in this negative consequence of pollution from Mexico due to implementation of the Core
Projects. This would improve water quality in the marine environment and benefit ESA-listed
species and EFH in the evaluated area. Implementation of Core Projects would therefore not be
expected to result in substantial disturbances to ESA-listed species or EFH due to HABs.
The extensive environmental monitoring program conducted by the City of San Diego on the
ongoing SBOO discharge has, to date, not identified any effects on EFH, including the Imperial Beach
Kelp Forest (City of San Diego, 2013, 2016c, 2018a, 2020b, 2022a). The expansion of discharge
volume through the SBOO under Alternative 1 would result in an increase in the extent of the
detectable plume and pollutant loadings. However, the increase in the treated effluent plume extent
would be a direct result of the effort to decrease nearshore pollution from transboundary flows.
Currently, the effects of ongoing transboundary flows originating from SAB Creek and the Tijuana
River Estuary on the Imperial Beach Kelp Forest HAPC are uncertain. The sizeable, persistent flows
of untreated wastewater originating at SAB Creek (which includes raw sewage) have been shown to
envelop the Imperial Beach Kelp Forest on a regular basis, and discharges from the Tijuana River
Estuary are a major source of nearshore pollution, particularly during wet-season outflows from
the estuary. It is highly likely that these polluting waters impact the quality of kelp canopy HAPC at
the Imperial Beach Kelp Forest. The Core Projects are intended to reduce these polluting events and
therefore would be likely to result in a net beneficial impact on EFH in the evaluated area.
Through consultation with NMFS, EPA prepared and submitted to NMFS a Biological Assessment in
accordance with ESA Section 7 with a determination that implementation of the Core Projects
would be likely to result in adverse effects to listed species identified as having medium to high
potential to occur within the Proposed Action area and may affect, but is not likely to adversely affect
all other listed species. EPA also submitted to NMFS an EFH Assessment in accordance with the
Magnuson-Stevens Fishery Conservation and Management (Magnuson-Stevens) Act with a
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determination that the Core Projects would adversely affect EFH within the evaluated area.
Consultation with NMFS is ongoing, and EPA anticipates issuance of a Biological Opinion from
NMFS that will include reasonable and prudent mitigation measures to minimize or offset potential
impacts to marine species and EFH, which will be incorporated into the ROD for this PEIS
(Mitigation Measure BR-34). See Sections 6.1.6 (Marine Biological Resources), 7.2.1 (Endangered
Species Act Section 7 Consultation), and 7.2.2 [Magnuson-Stevens Fishery Conservation and
Management Act Consultation (Essential Fish Habitat)], as well as Appendix F (NMFS Biological
Assessment) and Appendix G (NMFS Essential Fish Habitat Assessment) for additional information
about the determinations and consultation processes.
While the increase in pollutant discharges via the SBOO could affect individual animals belonging to
populations of conserved species, this would be unlikely to result in a substantial decline in the
population of these species. Alternative 1 would not result in significant impacts to marine
biological resources per the criteria in Section 4.5.1 (Standards of Significance).
4.5.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Under Alternative 2, implementation of the Core Projects would result in the same minor, short-
term impacts to marine biological resources as would occur under Alternative 1. Of the
Supplemental Projects, only Project E (APTP Phase 2) would require modifications to the diffusers
for additional discharges via the SBOO. The impacts associated with this additional modification
would be similar to those described above for Alternative 1. Additionally, it is possible that the
scope of Project G (New SABTP) could be modified to include installation of a subaquatic discharge
pipe. In that scenario, the subsequent tiered NEPA analysis for Project G would assess the potential
for transboundary effects on marine biological resources. These actions would not be expected to
result in significant impacts to marine biological resources per the criteria in Section 4.5.1
(Standards of Significance).
Permanent Effects
Under Alternative 2, implementation of the Core Projects would result in the same long-term net
beneficial impacts to marine biological resources as would occur under Alternative 1.
Implementation of Supplemental Project G would further decrease discharges of untreated effluent
to the Pacific Ocean via SAB Creek, while Supplemental Projects E, F (U.S.-side River Diversion to
APTP), and H (Tijuana WWTP Treated Effluent Reuse) would result in increased discharges of
primary-treated effluent to the Pacific Ocean via the SBOO. These increased discharges via the
SBOO are pollutants that, in the absence of the proposed APTP, would have potentially reached the
Tijuana River Estuary and Pacific Ocean via transboundary river flows.
Subsequent tiered NEPA analyses would further assess the relationships of these changes in
pollutant loadings to determine whether they would constitute a net reduction in loadings to the
marine environment and therefore a benefit to marine biological resources. The increase in
pollutant discharges via the SBOO under the Supplemental Projects has not yet been assessed with
respect to potential effects on individual animals. However, EPA and USIBWC anticipate that the
overall net benefit of the Core and Supplemental Projects (due to the reduction of pollutants in the
marine environment) would sufficiently offset any effects to individual animals and that there
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would be no substantial decline in these species' populations. Therefore, Alternative 2 would not
result in significant impacts to marine biological resources per the criteria in Section 4.5.1
(Standards of Significance).
4.5.5 Comparative Analysis of the Alternatives
Table 4-18 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
None of the evaluated alternatives would result in significant impacts to marine biological
resources per the criteria in Section 4.5.1 (Standards of Significance). Section 5 (Mitigation
Measures and Performance Monitoring) identifies the mitigation measures that would be
implemented for the Core Projects and provides recommended mitigation measures for the
Supplemental Projects (which would be further refined and developed in subsequent tiered NEPA
analyses).
Table 4-18. Comparative Analysis of Effects - Marine Biological Resources
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Potential minor, short-term effects
from noise and activity during vessel
use and diver activity
¦ Potential negligible impacts to marine
species due to collision risk from
vessel traffic and anchor deployment
¦ Potential minor impacts to seabed
communities and Groundfish EFH due
to anchor deployment
¦ Potential negligible impacts to marine
species or habitat due to risk of spill or
grounding from vessel accident
Same as Alternative 1
Permanent
effects
¦ Over time,
expected
contribution to
more frequent
and intense HAB
events and
general
degradation of
marine habitat
¦ Long-term beneficial effects from net
improvement to coastal water quality
and marine habitat due to pollutant
loading reductions, despite increased
loadings via SBOO
¦ Net beneficial impact on EFH
¦ EPA and USIBWC anticipate
conclusion of ESA Section 7 formal
consultation with NMFS issuance of a
Biological Opinion that includes
reasonable and prudent mitigation
measures, which will be incorporated
into the ROD for this PEIS
Same as Alternative 1, plus the
following:
¦ Additional long-term beneficial
effect from decrease in
nearshore pollution, along with
additional increase in pollutant
loadings via SBOO; subsequent
tiered NEPA analyses would be
required to assess the resulting
potential effects on marine
biological resources
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4.6 Geological Resources
4.6.1 Standards of Significance
Impacts to geological resources would be significant if they were to include any of the following:
• Exacerbation of, and/or exposure to, adverse conditions due to liquefaction, liquefiable
soils, unstable soils, or landslide potential.
• Modification of local topography such that it concentrates uncontrolled runoff or causes
major erosion.
• Adverse conditions affecting the stability of bedrock or the underlying geology.
• Extensive modification or destruction of unique geological or topographical features.
• High-occupancy development over a major fault such that risk to humans or structures
would incur.
4.6.2 No-Action Alternative
The No-Action Alternative would have no impacts to geology, soils, or topography and would have
no change in risk of seismic hazards.
4.6.3 Alternative 1: Core Projects
Temporary Effects
Under Alternative 1, construction activities for the Core Projects would disturb soils as a result of
site preparation, grading and/or filling, trenching, and other construction activities primarily
within the ITP parcel, creating the potential for minor, short-term impacts from soil runoff and
erosion. As summarized in Table 4-19, Alternative 1 would result in a total of up to approximately
33 acres of temporary surface disturbance (portions of which would potentially be disturbed
multiple times by different, non-concurrent projects), 321,000 SF of open-cut trenching, and 6,200
linear feet of micro-tunneling for all Core Projects combined. Projects with micro-tunneling
(Projects B [Tijuana Canyon Flows to ITP] and D [APTP Phase 1]) would potentially result in
impacts to the underlying geology, including transboundary impacts for work under the border,
and would result in soil disturbance for temporary pits at each end of the micro-tunnel ground
entrances. No other Core Projects would result in impacts to the underlying geology or
transboundary impacts. Alternative 1 would not result in significant impacts to geological resources
per the criteria in Section 4.6.1 (Standards of Significance).
For all Core Projects, use of temporary equipment staging areas would create areas of compacted
soil. Most of this would occur under Project A (Expanded ITP), which would result in moderate
compaction due to staging activities in the undeveloped 25-acre southwest quadrant of the ITP
parcel.
In Smuggler's Gulch, personnel and infrastructure for Project B (Tijuana Canyon Flows to ITP)
would be exposed to potential landslide risks during construction activities; however, personnel
would only be onsite during construction and during limited O&M activities and therefore would
have extremely low potential to risk loss of life or injury should a landslide event occur. No other
Core Projects would involve exposure to landslide risks during either construction or operation.
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Table 4-19. Temporary Ground Disturbance in the U.S.
Project
Open-Cut Trenching
Micro-tunneling or Directional Drilling
Surface Disturbance
Project A
None
None
Up to 18.6 acres
Project Ba
Up to 276,000 SFb
(Option Bl)
Up to 6,000 linear feet (Option B2)
Up to 6.4 acres (Option Bl)
Project C
N/A
N/A
N/A
Project D
Up to 45,000 SFb
Up to 200 linear feet
Up to 8.3 acres
Total
Up to 321,000 SF b
Up to 6,200 linear feet
Up to 33.2 acres
a - Option with the largest impact is specified,
b - Assumes a 25-foot-wide area for trenching activities.
Permanent Effects
Under Alternative 1, implementation of the Core Projects would result in a total of up to
approximately 12.3 acres of permanent development for all Core Projects combined. The Core
Projects are located near to known but likely inactive faults along the border but would not be
exposed to the substantial earthquake hazards of major fault zones due to their distance from these
zones. Core Projects would not be anticipated to impact underlying geology; however, geotechnical
studies would be needed during project design to confirm that no bedrock modifications would be
necessary to support new structures. The Core Projects would not result in any transboundary
effects on geological resources. Alternative 1 would not result in significant impacts to geological
resources per the criteria in Section 4.6.1 (Standards of Significance).
Project A (Expanded ITP) would require the import of up to 40,000 cubic yards of fill material to
provide a level foundation for new treatment infrastructure, potentially raising ground surface
elevations by up to approximately 10 feet in some areas within the ITP parcel and resulting in a
minor modification of local topography. To the extent feasible, the project would reuse excess spoils
generated during construction within the ITP parcel, such as from excavation to build subsurface
portions of the secondary clarifiers and reactors. Additional fill material, if needed, would be
sourced from elsewhere within the Tijuana River Valley, such as the transboundary sediment
deposits in Goat Canyon or Smuggler's Gulch. No other Core Projects would modify topography.
Project A would result in permanent development (conversion to impervious surface area) of up to
approximately 11.3 acres of the undeveloped 25-acre southwest quadrant of the ITP parcel for
construction of new facilities and pavement. The larger expansion of the ITP (Option A3) would
require more development (i.e., closer to the approximate 11.3-acre estimate) than the smaller
expansion (Options A1 and A2) to accommodate additional treatment infrastructure. Additionally,
Project D (APTP Phase 1) would result in the permanent development (conversion to impervious
surface area) of approximately 2 acres of ground surface. No other Core Projects would involve
permanent development resulting in conversion of soil and ground surface to impervious surfaces.
Project A development at the ITP parcel and Project B (Tijuana Canyon Flows to ITP) pipe
installation along Monument Road would occur in areas mapped as having high liquefaction
potential, while Project B construction in Smuggler's Gulch would occur in an area mapped as
having low liquefaction potential; project components in areas subject to liquefaction would be
designed to be seismically resistant in accordance with applicable seismic design standards, and all
project components would be designed to reflect the findings and recommendations of future
project-specific geotechnical studies. No other Core Projects would involve constructing new
infrastructure in areas mapped as having high liquefaction potential.
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4.6.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Under Alternative 2, implementation of the Core Projects would result in the same minor, short-
term impacts to geological resources as would occur under Alternative 1. However, the total
acreage of temporary surface disturbance, open-cut trenching, and micro-tunneling for
Supplemental Projects is indeterminable at this time and would be characterized in subsequent
tiered NEPA analyses. The general construction activities (e.g., site preparation, grading and/or
filling, trenching, temporary pits for micro-tunneling, and temporary staging areas) and their
related impacts described above for Core Projects would be applicable to similar construction
activities for the Supplemental Projects. Projects with micro-tunneling (Project I [ITP Treated
Effluent Reuse]) would potentially result in impacts to the underlying geology and would result in
soil disturbance for temporary pits at each end of the micro-tunnel ground entrances. No other
Supplemental Projects would result in impacts to the underlying geology, and none would result in
transboundary impacts. Alternative 2 would not result in significant impacts to geological resources
per the criteria in Section 4.6.1 (Standards of Significance).
Project F (U.S.-side River Diversion to APTP) would require soil excavation and temporary
damming and flow diversion of the Tijuana River and open-cut trenching for installation of pipeline
from the diversion to the APTP. However, Project F would have no impacts to topography or the
underlying geology because localized topographical conditions would be restored to
preconstruction conditions and excavations would not reach bedrock under the deep alluvial
sediment of the main channel. Project I would include open-cut trenching in the ITP parcel for
installation of a new treated effluent pipeline, which would temporarily disturb soils. The extent
and degree of impact would be dependent on future design and placement of the pipeline (to be
evaluated in tiered NEPA analyses). Project J (Trash Boom[s]) would temporarily disturb soils for
limited grading in the Tijuana River main channel and would also require localized excavation to
construct the concrete footings that would secure the ends of the trash boom. Project J would have
no impacts to topography or the underlying geology for the same reasons described above for
Project F.
Permanent Effects
Under Alternative 2, implementation of the Core Projects would result in the same impacts to
geological resources as would occur under Alternative 1. However, the total acreage of permanent
development for all Supplemental Projects is indeterminable at this time and would be
characterized in subsequent tiered NEPA analyses. Similar to the Core Projects, the Supplemental
Projects are located near to known but likely inactive faults along the border but would not be
exposed to the substantial earthquake hazards of major fault zones due to their distance from these
zones. Except for Project I, which includes micro-tunneling at the border and which has the
potential to impact bedrock if present, Supplemental Projects would have no permanent impacts to
underlying geology or topography due to lack of permanent surface modifications and lack of
drilling or excavation activities that might affect bedrock. Alternative 2 would not result in
significant impacts to geological resources per the criteria in Section 4.6.1 (Standards of
Significance).
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Project E (APTP Phase 2) would potentially include a minor increase from Project D (APTP Phase 1)
in the amount of permanent development (conversion to impervious surface area), though Phase 1
is expected to include all concrete pads necessary to support process units under both phases and
thus ensure soil and foundation stability for the overall plant Project F (U.S.-side River Diversion to
APTP) would result in permanent development of up to approximately 8 acres of the Tijuana River
main channel, depending on final siting location and whether a concrete apron is necessary to
ensure capture of flows. Project J (Trash Boom[s]) would result in minor amounts of permanent
development that would be further characterized in subsequent tiered NEPA analyses.
It is not known whether operation of the river diversion under Project F would affect downstream
soils by modifying sediment deposition patterns during certain transboundary flow conditions.
Additionally, during operations for Project J, extracted trash would potentially require a designated
processing area near to the boom. This processing area would require a permanent access road and
would experience repeated heavy equipment traffic and potential soil compaction. These unknown
and potential impacts would require evaluation in subsequent tiered NEPA analyses.
Project E development in the northern portion of the ITP parcel, along with Projects F and J, would
occur in areas mapped as having high liquefaction potential; project components in areas subject to
liquefaction would be designed to be seismically resistant in accordance with applicable seismic
design standards, and all project components would be designed to reflect the findings and
recommendations of future project-specific geotechnical studies. No other Supplemental Projects
would involve constructing new infrastructure in areas mapped as having high liquefaction
potential.
4.6.5 Comparative Analysis of the Alternatives
Table 4-20 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
None of the evaluated alternatives would result in significant impacts to geological resources per
the criteria in Section 4.6.1 (Standards of Significance). Section 5 (Mitigation Measures and
Performance Monitoring) identifies the mitigation measures that would be implemented for the
Core Projects and provides recommended mitigation measures for the Supplemental Projects
(which would be further refined and developed in subsequent tiered NEPA analyses).
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Table 4-20. Comparative Analysis of Effects - Geological Resources
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Minor, short-term impacts from
disturbance of up to 33.2 acres of soil
due to site preparation, grading,
and/or filling; up to 321,000 SF of
open-cut trenching; and up to 6,200
linear feet of micro-tunneling or
directional drilling (includes
disturbance for staging activities and
stormwater management in the
southwest quadrant of the ITP parcel)
¦ Exposure to potential landslide risks
during construction activities in
Smuggler's Gulch
Same as Alternative 1, plus the
following:
¦ Additional short-term impacts from
disturbance of soils in the Tijuana
River main channel (acreage
undetermined) for damming and flow
diversion of the river, pipeline
trenching, and trash boom installation
¦ Additional minor, short-term impacts
from soil disturbance within ITP parcel
Permanent
effects
¦ None
¦ Minor, localized long-term effects
from modification to topography
within ITP parcel
¦ Permanent impacts from development
(conversion to impervious surface
area) of up to approximately 12.3 total
acres
¦ Construction (in accordance with
applicable seismic design standards) in
areas mapped as having high
liquefaction potential at the ITP and
low liquefaction potential in
Smuggler's Gulch
Same as Alternative 1, plus the
following:
¦ Potential long-term impacts from
permanent development (conversion
to impervious surface area) of up to
approximately 8 acres of the riverbed,
plus other minor, long-term impacts
from development for the trash
boom(s) and APTP Phase 2
4.7 Cultural Resources
4.7.1 Standards of Significance
Impacts to cultural resources would be significant if they were to include any of the following:
• Substantial disturbance or destruction of a property or site that is eligible for listing in the
NRHP and/or the CRHR.
• Interference with tribal religious or sacred uses of the affected property.
• Disturbance of Native American human remains, funerary objects, sacred objects, or objects
of cultural patrimony.
4.7.2 No-Action Alternative
The No-Action Alternative would have no impacts to cultural resources.
4.7.3 Alternative 1: Core Projects
Implementation of Core Projects under Alternative 1 would have no impacts on cultural resources
as there are no resources located in the vicinity of the project areas listed or eligible for listing in
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the NRHP or CRHR. The Project APE does not include any properties of known religious or sacred
significance to Native American tribes, nor does it include any known or suspected Native American
human remains, funerary objects, sacred objects, or objects of cultural patrimony. Therefore,
Alternative 1 would not result in significant impacts to cultural resources per the criteria in Section
4.7.1 (Standards of Significance). Project components in Mexico would have no effect on cultural
resources in the U.S. because their impacts would be limited to construction in their immediate
vicinity and would not extend across the border.
Alternative 1 intersects four prehistoric sites (CA-SDI-4933, CA-SDI-8604, CA-SDI-8605, and CA-
SDI-13486) that have previously been evaluated as not significant and recommended as not eligible
for listing in the NRHP and CRHR. Thus, the Proposed Action would not have an adverse effect on
the sites. The Project APE also intersects four formally unevaluated cultural resources. The cultural
resources consist of one heavily disturbed but inadequately defined multicomponent site (CA-SDI-
23075) and three historic sites whose built components have all been destroyed except for a few
remnants of cobble walls. Based on the current survey results and previous investigations, these
sites are preliminarily recommended as not significant and therefore not eligible for listing in the
NRHP. Construction for Core Projects would not intersect with the unevaluated site (CA-SDI-
23075). Construction activities in Smuggler's Gulch and along Monument Road for Project B
(Tijuana Canyon Flows to ITP) would potentially intersect with three unevaluated cultural
resources (CA-SDI-11096H, CA-SDI-11948H, and P-37-039462) that would require avoidance.
Avoidance of these resources would likely be feasible for the Core Projects. Should the Core Project
plans change and avoidance become infeasible, a formal evaluation for eligibility to the NRHP is
recommended for these resources prior to their destruction.
Operational activities associated with Alternative 1 would not have any effects on cultural
resources.
The Class III Cultural Resource Inventory results can be found in Appendix C (Class III Cultural
Resource Inventory [Public Version]). Because EPA would enact avoidance measures during
construction and would thus be treating the unevaluated resources as eligible for listing in the
NRHP, EPA has determined that the Proposed Action (including both Alternative 1 and Alternative
2) would have no adverse effects on cultural resources. EPA received OHP concurrence with this
determination on June 26, 2022 and also conducted outreach to Native American tribes to ensure
that ground-disturbing activities during construction would not affect cultural resources. See
Sections 6.1.7 (Cultural Resources), 7.2.3 (National Historic Preservation Act Section 106
Consultation), and Section 7.2.4 (Government-to-Government Consultation with Native American
Tribes) for additional information.
4.7.4 Alternative 2: Core and Supplemental Projects
Under Alternative 2, implementation of Core Projects would result in the same impacts on cultural
resources as would occur under Alternative 1. Implementation of Supplemental Projects under
Alternative 2 would intersect only one cultural resource, which is also intersected by the Core
Projects as discussed above. The affected area does not include any properties of known religious
or sacred significance to Native American tribes, nor does it include any known or suspected Native
American human remains, funerary objects, sacred objects, or objects of cultural patrimony.
Alternative 2 would not result in any significant impacts to cultural resources per the criteria in
Section 4.7.1 (Standards of Significance). Project components in Mexico would have no effect on
cultural resources in the U.S. because their impacts would be limited to construction in their
immediate vicinity and would not extend across the border.
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Construction activities for Projects E (APTP Phase 2) and I (ITP Treated Effluent Reuse) would
intersect with one of the prehistoric sites discussed above for the Core Projects. The site (CA-SDI-
13486) does not require avoidance. Construction for Supplemental Projects would not intersect
with any other cultural resources. Thus, the construction of Supplemental Projects would not have
an adverse effect on the sites.
Operational activities associated with Alternative 2 would not have any effects on cultural
resources.
The Class III Cultural Resource Inventory results can be found in Appendix C (Class III Cultural
Resource Inventory [Public Version]). As discussed above for Alternative 1, EPA has determined
that the Proposed Action (including both Alternative 1 and Alternative 2) would have no adverse
effects on cultural resources and received OHP concurrence with this determination. See Sections
6.1.7 (Cultural Resources), 7.2.3 (National Historic Preservation Act Section 106 Consultation), and
Section 7.2.4 (Government-to-Government Consultation with Native American Tribes) for
additional information.
4.7.5 Comparative Analysis of the Alternatives
Table 4-21 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
None of the evaluated alternatives would result in significant impacts to cultural resources per the
criteria in Section 4.7.1 (Standards of Significance). Section 5 (Mitigation Measures and
Performance Monitoring) identifies the mitigation measures that would be implemented for the
Core Projects and provides recommended mitigation measures for the Supplemental Projects
(which would be further refined and developed in subsequent tiered NEPA analyses).
Table 4-21. Comparative Analysis of Effects - Cultural Resources
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ No adverse effects on cultural resources
¦ Potential for construction to intersect with
four resources determined ineligible for
listing in the NRHP
¦ Potential for construction to intersect with
three unevaluated cultural resources that
would require avoidance
¦ Same as Alternative 1
Permanent
effects
¦ None
¦ None
¦ None
4.8 Visual Resources
4.8.1 Standards of Significance
Impacts to visual resources would be significant if they were to result in any of the following:
• Introduction of features that would detract from or contrast with the existing visual
character or quality of the localized area (e.g., by resulting in bulk, scale, materials, or style
that would be incompatible with surrounding development).
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• Substantial obstruction, interruption, or detraction from a valued focal and/or panoramic
vista from a public road, trail within an adopted county or state trail system, scenic vista or
highway, recreational area, or public vantage point as identified in a community plan.
• Removal or adverse change of one or more designated features that contribute to the visual
character or image of the localized area (e.g., designated landmarks, historic resources, a
landmark tree, a stand of mature trees, and rock outcroppings).
• Substantial change to the existing landform, natural topography, or other ground surface
relief features through landform alteration.
• Emission or reflection of a significant amount of light or glare.
Regulations and requirements to protect visual resources are described in Section 6.1.8 (Visual
Resources).
4.8.2 No-Action Alternative
The No-Action Alternative would have no impacts to visual resources. Transboundary flows would
continue to carry visible trash from Mexico to downstream areas in the U.S.
4.8.3 Alternative 1: Core Projects
Temporary Effects
Under Alternative 1, Core Projects would result in a minor, short-term impact from diminishment
of views to accommodate construction activities that may be partially visible from recreational
areas, public roads, scenic overlooks, and limited areas in Tijuana. However, construction activities
for Core Projects would be short-term and would not result in significant impacts to visual
resources per the criteria in Section 4.8.1 (Standards of Significance).
Specifically, construction activities and staging areas for Projects A (Expanded ITP) and D (APTP
Phase 1) would potentially be visible from portions of Dairy Mart Road, Monument Road, Camino
de la Plaza, the scenic overlook adjacent to Bibler Drive, and certain public roads and properties in
Tijuana adjacent to the U.S.-Mexico border. Construction activities for Project B (Tijuana Canyon
Flows to ITP) would potentially be visible from recreational areas (e.g., trails in Smuggler's Gulch)
and Monument Road. However, construction would be short-term, would not obstruct views, and
would not alter the visual character. Construction activities viewed from areas east and north of
Camino de la Plaza would be at least partially obscured by an existing fence that extends along the
length of the road. Transboundary visual impacts would be at least partially obscured by the border
fence.
During construction for all Core Projects, lighting would be minimized when practicable, would be
consistent with applicable lighting regulations and ordinances, and would not produce excessive
light pollution or glare.
Construction of project components in Mexico would have no transboundary impacts to visual
resources in the U.S. because any visual impacts would be limited to the immediate vicinity of the
project and would not extend across the border.
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Permanent Effects
Under Alternative 1, new infrastructure and minor landform alterations associated with
implementation of the Core Projects would potentially be visible from public roads, scenic
overlooks, and limited areas in Tijuana. However, implementation of the Core Projects would not
result in significant impacts to visual resources per the criteria in Section 4.8.1 (Standards of
Significance).
Specifically, new infrastructure built for Projects A (Expanded ITP) and D (APTP Phase 1) would
have potential minor visibility from Dairy Mart Road, Monument Road, Camino de la Plaza, the
scenic overlook adjacent to Bibler Drive, and certain public roads and properties in Tijuana
adjacent to the U.S.-Mexico border. New infrastructure would be built with a similar style, size, and
height as the immediately adjacent existing wastewater treatment facilities and would thus be
consistent with the existing visual character of the localized area. New infrastructure viewed from
areas east and north of Camino de la Plaza would be at least partially obscured by an existing fence
that extends along the length of the road. Transboundary visual impacts would be at least partially
obscured by the border fence.
Minor topographic changes and/or land conversion would occur to accommodate implementation
of Projects A and D. However, any topographic or landform alteration would be limited to the ITP
parcel, would not affect scenic views of mesas, and would be consistent with the existing visual
character. See Section 4.6 (Geological Resources) for additional information about potential impacts
to the existing landform and topography.
Operational lighting for Projects A and D would be installed and operated in accordance with
applicable regulations and ordinances and would not produce excessive light pollution or glare.
No other components of Core Projects would result in permanent effects on visual resources in the
U.S.
4.8.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Under Alternative 2, construction activities would result in minor, short-term effects on visual
resources similar to those that would occur under Alternative 1; however, Alternative 2 would
require a greater amount of construction for implementation of Supplemental Projects.
Implementation of the Core Projects would result in the same impacts to visual resources as
described above for Alternative 1. Construction of certain Supplemental Projects would also
potentially result in temporary alterations to landform or ground surface relief features. However,
construction activities for Alternative 2 would be short-term and would not result in significant
impacts to visual resources per the criteria in Section 4.8.1 (Standards of Significance).
Construction activities and staging areas for Projects E (APTP Phase 2), F (U.S.-side River Diversion
to APTP), I (ITP Treated Effluent Reuse), and J (Trash Boom[s]) would potentially be visible from
portions of Dairy Mart Road, Monument Road, Camino de la Plaza, the scenic overlook adjacent to
Bibler Drive, and certain public roads and properties in Tijuana adjacent to the U.S.-Mexico border.
However, construction would be short-term, would not obstruct views, and would not alter the
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visual character. Construction activities viewed from areas east and north of Camino de la Plaza
would be at least partially obscured by an existing fence that extends along the length of the road.
Transboundary visual impacts would be at least partially obscured by the border fence.
As described in Section 4.6 (Geological Resources), Project F would potentially result in temporary
minor changes in the visual characteristics of the landform due to short-term damming of the
Tijuana River during construction of the river diversion structure. However, construction activities
would be short-term and localized, and would not be expected to permanently alter the visual
landform or topography. Impacts from Project F would be dependent on the location and design of
the river diversion structure, which would be further defined and analyzed in subsequent tiered
NEPA analyses.
During construction for Alternative 2, lighting would be minimized when practicable, would be
consistent with applicable lighting regulations and ordinances, and would not produce excessive
light pollution or glare.
No other components of Alternative 2 would result in temporary effects on visual resources in the
U.S.
Permanent Effects
Under Alternative 2, Core Projects would have the same permanent effects as described above for
Alternative 1. Alternative 2 would not remove or change designated features that contribute to the
visual character and would not produce excessive light or glare. However, certain Supplemental
Projects implemented under Alternative 2 would potentially alter the landform and introduce
features that would detract from or contrast with the existing visual character of the localized area.
New infrastructure built for Projects E (APTP Phase 2) and I (ITP Treated Effluent Reuse) would
have potential minor visibility from Dairy Mart Road, Monument Road, Camino de la Plaza, the
scenic overlook adjacent to Bibler Drive, and certain public roads and properties in Tijuana
adjacent to the U.S.-Mexico border. New infrastructure would be built with a similar style, size, and
height as the immediately adjacent existing wastewater treatment facilities and would thus be
consistent with the existing visual character of the localized area.
Implementation of Projects F (U.S.-side River Diversion to APTP) and J (Trash Boom[s]) would
result in the potential visibility of the river diversion structure, trash boom(s), and maintenance
equipment from Dairy Mart Road, Monument Road, Camino de la Plaza, and certain public roads
and properties in Tijuana adjacent to the U.S.-Mexico border.62 The trash boom(s) and maintenance
activities for Project J would also have potential visibility from the scenic overlook adjacent to
Bibler Drive. As discussed in Section 4.6 (Geological Resources), Projects F and J would also require
permanent land conversion, which would alter the local appearance. The diversion of a portion of
wet-weather flows under Project F would have the potential to influence the visual characteristics
of downstream areas with groundwater-dependent riparian vegetation and habitat. In addition,
O&M for Project J would result in the accumulation of trash upstream of the trash boom(s) and in
trash processing area(s) that may be visible. These features would potentially detract from the
existing visual character or quality of the localized area. However, by decreasing the amount of
62 See Section 4.15 (Public Services and Utilities) regarding potential impacts of these projects to CBP
surveillance activities.
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trash in downstream portions ofthe Tijuana River, Project J would also potentially improve the
visual character of the Tijuana River Valley and Estuary. Potential impacts to visual resources
would be dependent on the location and design of the river diversion, trash boom(s), and trash
processing area(s), and on the capture efficiency of the trash boom(s), which would be further
defined and analyzed in subsequent tiered NEPA analyses with input from the local community.
For all projects, new infrastructure and maintenance activities viewed from areas east and north of
Camino de la Plaza would be at least partially obscured by an existing fence that extends along the
length of the road. Transboundary visual impacts would be at least partially obscured by the border
fence.
Operational lighting for Supplemental Projects would be installed and operated in accordance with
applicable regulations and ordinances and would not produce excessive light pollution or glare.
No other components of Alternative 2 would result in permanent effects on visual resources in the
U.S.
See Section 4.20 (Environmental Justice) regarding disproportionately high and adverse effects due
to impacts to visual resources under Alternative 2.
4.8.5 Comparative Analysis of the Alternatives
Table 4-22 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
Certain components of the evaluated alternatives would, in the absence of mitigation, potentially
result in significant impacts to visual resources per the criteria in Section 4.8.1 (Standards of
Significance). Section 5 (Mitigation Measures and Performance Monitoring) identifies the mitigation
measures that would be implemented for the Core Projects and provides recommended mitigation
measures for the Supplemental Projects (which would be further refined and developed in
subsequent tiered NEPA analyses).
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Table 4-22. Comparative Analysis of Effects - Visual Resources
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Minor, short-term impacts to
visual resources from construction
activities, involving:
- No detraction from the visual
character or quality of the
localized area
- No visibility from Interstate 5
- No substantial landform
alteration
¦ Potential minor, short-term
impacts from diminishment of
views from recreational areas,
public roads, scenic overlooks, and
Tijuana
¦ Minor, short-term impacts from
construction lighting that would
not produce excessive light
pollution or glare (consistent with
applicable regulations and
ordinances)
Same as Alternative 1, plus the
following:
¦ Slight increase in the duration and
visibility of construction activities
¦ Potential minor, short-term impacts
from changes in visual characteristics
of the landform during construction of
the U.S.-side river diversion
Permanent
effects
¦ None
¦ No reduction in
impacts of
trash in
transboundary
flows on
downstream
visual
resources
¦ Minor, long-term impacts to visual
resources from new infrastructure
and minor landform alterations,
involving:
- No detraction from the visual
character or quality of the
localized area
- No visibility from Interstate 5
¦ Minor, long-term impacts from the
introduction of infrastructure and
minor landform alterations on the
ITP parcel potentially visible from
public roads, scenic overlooks, and
Tijuana (consistent with visual
character)
¦ Minor, long-term impacts from
operational lighting that would not
produce excessive light pollution
or glare (consistent with applicable
regulations and ordinances)
¦ Potential significant, long-term impact
from detraction of the visual character
or quality of the localized area due to
introduction of physical structures,
land conversion, and O&M associated
with the U.S.-side river diversion and
trash boom(s) (see Section 5 for
potential mitigation measures)
¦ No visibility from Interstate 5
¦ Minor, long-term impacts from the
introduction of infrastructure and
minor landform alterations on the ITP
parcel potentially visible from public
roads, scenic overlooks, and Tijuana
(consistent with visual character)
¦ Minor, long-term impacts from
potential downstream changes to
visual character or quality of the
Tijuana River Valley and Estuary due
to reduced wet-weather flows and
trash deposition
¦ Minor, long-term impacts from
operational lighting that would not
produce excessive light pollution or
glare (consistent with applicable
regulations and ordinances)
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4.9 Land Use
4.9.1 Standards of Significance
Impacts to land use would be significant if they were to result in any of the following:
• Change or modification to land use in a way that is inconsistent with previously designated
land uses.
• Required changes to existing land use plans in order for the project to be implemented.
• Widespread changes in land ownership.
• Use of eminent domain.
4.9.2 No-Action Alternative
The No-Action Alternative would have no impacts to land use.
4.9.3 Alternative 1: Core Projects
Temporary Effects
Certain projects in Alternative 1 would result in minor, short-term effects on land use to
accommodate construction activities. Specifically, Projects A (Expanded ITP) and D (APTP Phase 1)
would result in temporary use (e.g., material/equipment staging and stormwater management) of
the undeveloped 25-acre southwest quadrant of the ITP parcel. Use of this area would require
coordination with CBP to avoid conflicts with future CBP construction staging needs. No other Core
Projects would result in temporary effects on land use. While construction activities under any of
the Core Projects could temporarily impact site access in certain areas, this would not affect how
sites are actively used other than as described above for construction within the ITP parcel.
Alternative 1 would result in no short-term changes to agricultural, military, or mineral land uses
because these land uses are not present in the construction area. Short-term transboundary effects
from actions in Mexico (e.g., due to construction noise) under Alternative 1 would not affect access
to, or use of, land in the U.S.
See Section 4.15 (Public Services and Utilities) for discussion of impacts to CBP ability to perform
patrols and execute their mission.
Permanent Effects
Certain projects in Alternative 1 would result in minor, long-term effects on land use. Specifically,
Project A (Expanded ITP) would result in conversion of up to approximately 10 acres of the
undeveloped 25-acre southwest quadrant of the ITP parcel to land permanently used for
wastewater infrastructure, which would be consistent with the surrounding land use. This land use
conversion would preclude continued or future use of this area by CBP for border operations such
as construction staging. The larger expansion of the 60-MGD ITP (Option A3) would likely require
more land (i.e., closer to the approximate 11.3-acre estimate) in the southwest quadrant of the ITP
parcel than the smaller expansion (Option Al) to accommodate additional treatment infrastructure.
Project A would include no long-term changes to any other recreational, agricultural, military,
mineral, or other land uses. Additionally, Project D (APTP Phase 1) would include the development
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of a small portion of the ITP parcel (approximately 2-4 acres) to land permanently used for
wastewater infrastructure, which would be consistent with surrounding land use.
No other components of Alternative 1 would result in long-term effects on land use.
Alternative 1 would result in no changes in land ownership, no use of eminent domain, and no long-
term changes to agricultural, military, or mineral land uses because these land uses are not present
in the project area. Long-term transboundary effects from actions in Mexico (e.g., reductions in
contaminated transboundary flows) under Alternative 1 would not affect access to, or use of, land
in the U.S. but would potentially benefit recreational use of parks and beaches in a manner
consistent with existing land use designations.
No land use plan changes would need to occur to allow Alternative 1 to move forward (see land use
plans listed in Section 3.9 [Land Use]).
4.9.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Under Alternative 2, Core Projects would have the same minor, short-term effects on land use as
described above for Alternative 1. The Supplemental Projects would not result in any additional
temporary effects on land use. While construction activities for Supplemental Projects could
temporarily impact site access in certain areas, this would not affect how sites are actively used
other than as described above for construction within the ITP parcel.
Alternative 2 would result in no short-term changes to agricultural, military, or mineral land uses
because these land uses are not present in the project area. Short-term transboundary effects from
actions in Mexico (e.g., due to construction noise) under Alternative 2 would not affect access to, or
use of, land in the U.S.
Permanent Effects
Under Alternative 2, Core Projects would have the same minor, long-term effects as described
above for Alternative 1. Certain Supplemental Projects in Alternative 2 would result in permanent
effects on existing land uses. Specifically, Project E (APTP Phase 2) would expand the treatment
footprint further for the APTP within the ITP parcel; similar to Project D (APTP Phase 1), this would
be consistent with the surrounding land use. Project F (U.S.-side River Diversion to APTP) would
involve permanent installation of wastewater infrastructure (i.e., the Tijuana River diversion
system) on land primarily used for flood control but would otherwise result in no land use changes.
Project J (Trash Boom[s]) would involve the addition of trash collection, processing, and disposal
operational activities in the Tijuana River main channel on land primarily used for flood control but
would otherwise result in no land use changes.
No other components of Alternative 2 would result in long-term effects on land use.
Alternative 2 would result in no changes in land ownership; no use of eminent domain; and no long-
term changes to agricultural, military, or mineral land uses because these land uses are not present
in the construction area. Long-term transboundary effects from actions in Mexico (e.g., reductions
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in contaminated transboundary flows) under Alternative 2 would not affect access to, or use of,
land in the U.S. but would potentially benefit recreational use of parks and beaches in a manner
consistent with existing land use designations.
No land use plan changes would need to occur to allow Alternative 2 to move forward (see land use
plans listed in Section 3.9 [Land Use]).
4.9.5 Comparative Analysis of the Alternatives
Table 4-23 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
None of the evaluated alternatives would result in significant impacts to land use per the criteria in
Section 4.9.1 (Standards of Significance).
Table 4-23. Comparative Analysis of Effects - Land Use
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Minor, short-term impacts from the
use of the undeveloped 25-acre
southwest quadrant of the ITP parcel
Same as Alternative 1
Permanent
effects
¦ None
¦ Minor, long-term impacts to land use
(conversion of undeveloped land) in a
manner consistent with applicable
land use plans
¦ No land ownership changes or use of
eminent domain
¦ Minor, long-term impact from
conversion/development of up to
approx. 14 acres of land to wastewater
infrastructure use
Same as Alternative 1, plus the
following:
¦ Minor, long-term impact from
installation of wastewater
infrastructure (i.e., the Tijuana River
diversion system) on land primarily
used for flood control
¦ Minor, long-term impact from the
addition of trash-related infrastructure
and operations on land primarily used
for flood control
4.10 Coastal Zone
4.10.1 Standards of Significance
Impacts to the coastal zone would be significant if they were found to be inconsistent with the
enforceable policies of the California Coastal Management Program (CCMP).
4.10.2 No-Action Alternative
The No-Action Alternative would include the continuation of existing impacts to freshwater,
estuarine, and coastal resources that are currently resulting from contaminated transboundary
flows from Tijuana (see Section 1.3 [Causes and Impacts of Contaminated Transboundary Flows
from Tijuana] and Section 3.1 [Freshwater and Estuarine Resources]). These impacts would persist
unabated and would worsen over time as wastewater infrastructure in Tijuana continues to
deteriorate and the population continues to grow without access to adequate wastewater
treatment infrastructure.
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4.10.3 Alternative 1: Core Projects
Under Alternative 1, long-term impacts resulting from construction and operation of the Core
Projects—including transboundary water quality improvements from Mexico—would be generally
consistent with the enforceable policies of the CCMP. To analyze consistency with the CCMP, EPA
and USIBWC developed a coastal consistency determination and submitted it to the CCC on October
31, 2022. In this consistency determination, EPA and USIBWC analyzed the Core Projects'
consistency with each applicable policy of the CCA and determined that implementation of the Core
Projects would be consistent with some individual policies and would "neither directly promote nor
be inconsistent with" other individual policies. Findings of consistency were based on the fact that
the Core Projects would result in long-term beneficial impacts to downstream and coastal water
quality, which would promote protection of water-oriented recreational activities and oceanfront
land. However, the Core Projects would neither directly promote nor be inconsistent with certain
policies, as there may be localized impacts to the coastal zone from project construction and
operation. For example, implementation of the Core Projects could result in localized adverse water
quality impacts around the SBOO due to the increased discharges of treated effluent due to Projects
A (Expanded ITP) and D (APTP Phase 1). See Appendix H (Coastal Consistency Determination) for
more information.
The Core Projects are not inconsistent with any individual policy in the CCA and therefore would
not result in significant coastal zone impacts per the criteria in Section 4.10.1 (Standards of
Significance).
4.10.4 Alternative 2: Core and Supplemental Projects
Under Alternative 2, long-term impacts resulting from construction and operation of the Core
Projects would be the same as those under Alternative 1. However, construction and operation of
the Supplemental Projects—including additional transboundary water quality improvements from
Mexico—would result in additional impacts and benefits to resources of the coastal zone. These
additional impacts and benefits require further evaluation through the preparation and submittal of
a CZMA consistency determination (to be prepared and submitted during the subsequent tiered
NEPA analyses). For example, the consistency evaluation for Project F (U.S.-side River Diversion to
APTP) would need to evaluate the potential for the partial reduction in wet-weather river flows to
affect downstream habitat and local coastal currents, while accounting for projected sea level rise;
and would need to consider the potential reuse of sediments extracted from these diverted river
flows (e.g., for beach replenishment).
4.10.5 Comparative Analysis of the Alternatives
Table 4-24 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
None of the evaluated alternatives would be expected to result in significant impacts to the coastal
zone per the criteria in Section 4.10.1 (Standards of Significance).
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Table 4-24. Comparative Analysis of Effects - Coastal Zone
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Anticipated effects to be consistent
with or to neither directly promote
nor be inconsistent with enforceable
policies of the CCMP (pending
concurrence from CCC)
¦ Anticipated effects to be consistent
with or to neither directly promote
nor be inconsistent with enforceable
policies of the CCMP (to be
evaluated in a consistency
determination)
Permanent
effects
¦ None
¦ No reduction in
current impacts
of contaminated
transboundary
flows on coastal
resources
¦ Anticipated effects to be consistent
with or to neither directly promote
nor be inconsistent with enforceable
policies of the CCMP (pending
concurrence from CCC)
¦ Long-term beneficial effects from
the reduction in impacts of
contaminated transboundary flows
on coastal resources
Same as Alternative 1, plus the
following (to be evaluated in a
consistency determination):
¦ Additional long-term beneficial
effects from the reduction in
impacts of contaminated
transboundary flows on coastal
resources
¦ Potential long-term effect on
downstream and coastal resources
due to partial reduction in wet-
weather river flows
4.11 Air Quality and Odor
4.11.1 Standards of Significance
Impacts to air quality or odor would be significant if they were to result in any of the following:
• Total direct and indirect emissions of nonattainment criteria pollutants at levels that meet
or exceed the applicable Clean Air Act General Conformity Rule (GCR) de minimis thresholds
(40 CFR § 93.153), thus requiring a conformity determination.
• Emissions that exceed the Air Quality Impact Assessment (AQIA) trigger levels as presented
in the City of San Diego's CEQA Significance Determination Thresholds for air quality and
odor (City of San Diego, 2016a).
• Exposure of sensitive receptors to substantial pollutant concentrations, including air toxics
such as diesel particulates.
• Creation of objectionable odors affecting a substantial number of people.
4.11.2 No-Action Alternative
The No-Action Alternative would have no impacts to air quality or odor. The existing ITP and its
odor control scrubbers would continue to operate, occasionally producing emissions from
operation of the emergency generators. The No-Action Alternative would not achieve any reduction
in odor from contaminated transboundary flows in the Tijuana River, estuary, and coastal areas.
4.11.3 Alternative 1: Core Projects
EPA used CalEEMod (California Air Pollution Control Officers Association, 2022) and a variety of
emission factors to estimate direct and indirect emissions from Core Project construction activities
and operations in the U.S. Criteria pollutant emissions in the U.S. under Alternative 1 are
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summarized in Table 4-25, with comparisons to applicable screening thresholds. Documentation of
these model outputs and emissions estimates is provided in Appendix L (Emissions Calculations).
Table 4-25. Summary of Estimated Criteria Pollutant Emissions in the U.S. (Construction and
Operation) - Alternative 1
Pollutant
Emissions (tons/yr)a
Screening Thresholds
Threshold(s)
Exceeded?
2024
2025
2026
2027-Future
Years
GCR De
Minimis
Level
AQIA Trigger
Levelb
vocc
0.2
0.3
10.3
5.5
25
15
No
NOx
1.8
2.5
9.2
11.3
25
40
No
CO
1.4
3.6
16.8
28.2
100
100
No
S02
<0.01
0.01
0.02
<0.01
-
¦1^
O
Q_
No
PM10
0.7
0.6
0.7
0.3
-
15
No
PM2.5
0.4
0.2
0.3
0.1
-
-
No
a - Estimated emissions are based on completion of all construction activities for Core Projects in the U.S. by no
later than 2026, with plant operations under both Projects A and D beginning in 2026 and continuing in future
years. Estimates account for mobile source emissions, including on-road and non-road construction vehicles, truck
hauling of fill material and solids waste, and staff commuting. Estimates represent post-control emissions and
assume the use of selective catalytic reduction and catalytic oxidation at the anaerobic digestion facility under
Project A.
b - Per the City of San Diego's CEQA Significance Determination Thresholds for air quality and odor (City of San
Diego, 2016a).
c - Includes reactive organic gases, as calculated by CalEEMod.
d - Screening threshold is based on sulfur oxide emissions.
Temporary Effects
Under Alternative 1, as described below, construction activities for the Core Projects would result
in temporary emissions but would not result in significant impacts to air quality or odor per the
criteria in Section 4.11.1 (Standards of Significance).
Construction activities for the Core Projects would result in direct emissions of criteria air
pollutants (e.g., VOCs, NOx, PM, and CO) due to factors including combustion of fossil fuels by on-
road and non-road vehicles and equipment (including, but not limited to, dump trucks, tractors,
excavators, backhoes, dozers, and paving equipment), dust and soil disturbance, asphalt paving and
painting. The significant majority of these construction activities would take place at the ITP parcel,
where construction for Projects A (Expanded ITP) and D (APTP Phase 1) would be expected to take
approximately two years and one year, respectively. Project A would introduce new mobile source
emissions to and from the ITP parcel for truck hauling of imported fill material from fill source
locations in the Tijuana River Valley. Construction for Project B (Tijuana Canyon Flows to ITP),
depending on the selected option, would result in temporary PM and VOC emissions due to open-
cut trenching and asphalt pavement repairs along roads leading to the ITP, including Monument
Road.
Based on the estimates presented in Appendix L for emissions in the U.S., construction emissions
for the Core Projects would be well below the GCR de minimis levels and AQIA trigger levels. This
reflects a worst-case assumption that construction under Projects A and D would take place
concurrently. There are no known sensitive receptors in the vicinity of the ITP parcel or along
Monument Road or Dairy Mart Road south of Interstate 5, and construction activities would not be
expected to create objectionable odors.
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Due to the proximity to the U.S.-Mexico border and residential areas in Tijuana, construction
activities at the ITP parcel—particularly under Project A—would potentially result in minor
transboundary air quality effects on receptors in Mexico. Construction and sewage collector repair
activities under Projects B and C (Tijuana Sewer Repairs) that take place in Mexico near the U.S.-
Mexico border would have the potential to result in minor, temporary transboundary impacts to air
quality in the U.S. Construction activities in Mexico under Project D would not be expected to result
in transboundary impacts to air quality in the U.S. due to the limited scope of construction activities.
See Section 4.20 (Environmental Justice) regarding disproportionately high and adverse effects due
to air emissions under Alternative 1. See Section 4.21.5 (Cumulative Effects) regarding significant
cumulative air quality impacts that require mitigation, based on a review of the impacts of other
past, present, or reasonably foreseeable actions.
Permanent Effects
Under Alternative 1, as described below, operational activities for the Core Projects would result in
recurring emissions, some of which would require emissions and odor controls. Incorporation of
these required controls would ensure that emissions of criteria pollutants or air toxics would not
result in significant impacts to air quality per the criteria in Section 4.11.1 (Standards of
Significance). However, the expanded wastewater treatment processes would potentially result in
significant odor impacts per the criteria in Section 4.11.1 (Standards of Significance).
Under Project A (Expanded ITP), incorporation of anaerobic digestion, and the associated
requirement to combust the generated biogas (e.g., via flare, engine, or turbine), would drastically
increase the ITP's potential-to-emit (PTE) for regulated pollutants including NOx, non-methane
hydrocarbons/VOCs, and hazardous air pollutants (HAPs) including formaldehyde, as well as the
odorous compound H2S. Based on the PTE calculations provided in Appendix L, all three ITP
capacity options under Project A would trigger best available control technology (BACT)
requirements pursuant to SDAPCD Rule 20.2. Based on a review of control systems in place at other
WWTPs in California that feature anaerobic digestion, BACT emission controls for the expanded ITP
would most likely be required to incorporate biogas pretreatmentto remove formaldehyde and
H2S; selective catalytic reduction to remove NOx; catalytic oxidation to remove VOCs; and
combustion of biogas in a reciprocating engine, which could then be used to generate electricity to
help offset indirect emissions from electricity consumption at the expanded ITP. Incorporation of
BACT emission controls would render federal New Source Review (NSR) permitting requirements
not applicable. A more detailed analysis of the expanded ITP's potential emissions, the associated
control and permitting requirements, and additional best design practices to limit emissions (e.g.,
fugitive air emissions containment system to reduce H2S leaks) would be performed in coordination
with the SDAPCD during the project's design phase. Occasional operation of new emergency
generators atthe expanded ITP would not generate substantial emissions. See Section 6.1.10 (Air
Quality and Odor) for additional discussion of potential permitting requirements. Despite the
incorporation of odor controls and engineering measures to minimize fugitive emissions, H2S
emissions from the anaerobic digestion process under Project A—which would operate on a
continuous (or near-continuous) basis—would have the potential to create objectionable odors
affecting nearby communities.
Projects B (Tijuana Canyon Flows to ITP) and C (Tijuana Sewer Repairs) would not generate
operating emissions. The emissions estimates for Project A account for the additional wastewater
conveyed by these projects to the expanded ITP.
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Under Project D (APTP Phase 1), new stationary source emissions would generally be limited to
occasional operation of new emergency generators, which would not generate substantial
emissions. Due to the relatively low BOD concentrations in the influent water to the APTP,
substantial odors are not expected.
Operations under Projects A and D would increase recurring mobile source emissions to and from
the ITP parcel (e.g., along portions of Dairy Mart Road and through the Interstate 5 interchange)
due to increases in staff commuting and truck hauling of solid waste. As discussed in Section 4.17
(Transportation), these increases in traffic volume in the U.S. would be negligible compared to
existing levels. Operation of the new and expanded treatment plants under Projects A and D would
also generate indirect emissions due to factors including energy consumption, landfill use, and
water consumption.
Overall, based on the estimates presented in Table 4-25 and Appendix L for emissions in the U.S.,
the combined direct (post-control) and indirect emissions due to operations under the Core
Projects would be well below the GCR de minimis levels and AQIA trigger levels. There are no
known sensitive receptors in the vicinity of the ITP parcel on the U.S. side or along Monument Road
or Dairy Mart Road south of Interstate 5, and the nearest residential community in the U.S. is
located approximately 0.4 miles from the ITP. Operations would therefore not be expected to
expose sensitive receptors to substantial pollutant concentrations, but as noted above, would
potentially create objectionable odors affecting a substantial number of people.
By reducing transboundary river flows that are contaminated with untreated wastewater, the Core
Projects would be expected to reduce odors from untreated wastewater and standing water in the
Tijuana River, estuary, and coastal areas.
Due to the proximity of the proposed anaerobic digestion facility to the U.S.-Mexico border and
residential areas in Tijuana, operations under Project A would potentially result in transboundary
air quality effects, including nuisance odors, to receptors in Mexico. Under Project A, truck hauling
of solid waste to a disposal site in Mexico (though a dedicated ITP gate in the border fence) would
increase mobile source emissions in Mexico, which in turn could potentially contribute to existing
transboundary air quality impacts from Mexico to the U.S.
See Section 4.20 (Environmental Justice) regarding disproportionately high and adverse effects due
to air emissions and odor under Alternative 1. See Section 4.21.5 (Cumulative Effects) regarding
significant cumulative air quality impacts that require mitigation, based on a review of the impacts
of other past, present, or reasonably foreseeable actions.
4.11.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Under Alternative 2, as described below, construction activities would result in temporary
emissions but would not result in significant impacts to air quality or odor per the criteria in
Section 4.11.1 (Standards of Significance), pending further review in subsequent tiered NEPA
analyses.
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Under Alternative 2, construction activities for the Core Projects would result in the same impacts
to air quality and odor as would occur under Alternative 1. Construction activities for Supplemental
Projects E (APTP Phase 2), F (U.S.-side River Diversion to APTP), I (ITP Treated Effluent Reuse), and
J (Trash Boom[s]) would result in direct emissions of criteria air pollutants (e.g., VOCs, NOx, PM,
and CO) due to factors including combustion of fossil fuels and dust and soil disturbance. The
magnitude of these construction-related emissions in the U.S. would likely be similar to or less than
the magnitude of emissions from the Core Projects, which are estimated to be well below the GCR
de minimis levels and AQIA trigger levels. This would be characterized in subsequent tiered NEPA
analyses.
There are no known sensitive receptors in the vicinity of the ITP parcel or along Monument Road or
Dairy Mart Road south of Interstate 5, and the nearest residential community in the U.S. is located
approximately 0.4 miles from the ITP. Construction activities would not be expected to create
objectionable odors. However, construction for Projects F and J would potentially take place in
closer proximity to residential communities such as the Coral Gate neighborhood. A more thorough
identification of nearby sensitive receptors and assessment of air quality impacts to those receptors
would be performed in subsequent tiered NEPA analyses.
Due to the proximity to the U.S.-Mexico border and residential areas in Tijuana, construction
activities at the ITP parcel would potentially result in minor transboundary air quality effects on
receptors in Mexico. Construction for Projects G (New SABTP) and H (Tijuana WWTP Treated
Effluent Reuse) would not result in transboundary impacts to air quality in the U.S., as these
projects are several miles from the border and impacts would be expected to be localized.
See Section 4.20 (Environmental Justice) regarding disproportionately high and adverse effects due
to air emissions under Alternative 2. See Section 4.21.5 (Cumulative Effects) regarding significant
cumulative air quality impacts that require mitigation, based on a review of the impacts of other
past, present, or reasonably foreseeable actions.
Permanent Effects
Under Alternative 2, as described below, operations would potentially trigger significant impacts to
air quality or odor per the criteria in Section 4.11.1 (Standards of Significance), specifically with
regards to objectionable odors and potential impacts to sensitive receptors from Project J (Trash
Boom[s]). This would require further review in subsequent tiered NEPA analyses.
Under Alternative 2, operations for the Core Projects would result in the same impacts to air quality
and odor as would occur under Alternative 1. The Supplemental Projects would not involve any
new stationary sources in the U.S. other than possibly an additional emergency generator at the
APTP under Project E (APTP Phase 2)—which would not generate substantial emissions—and
potential for increased odor emissions from the expanded APTP.
Projects E, F (U.S.-side River Diversion to APTP), and H (Tijuana WWTP Treated Effluent Reuse)
would increase recurring mobile source emissions to and from the ITP parcel (e.g., along portions of
Dairy Mart Road and through the Interstate 5 interchange) due to increases in staff commuting and
truck hauling of solid waste. As discussed in Section 4.17 (Transportation), these increases in traffic
volume in the U.S. would be minor compared to existing levels.
Project J would increase recurring mobile source emissions for extraction of trash from the booms,
followed by truck hauling of the extracted trash for disposal. As discussed in Section 4.17
(Transportation), the volume, timing, and frequency of the hauling activities (e.g., several small
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hauling events versus one large hauling event) are indeterminable at this point. Depending on these
factors, Project J would potentially cause substantial localized increases in traffic volumes,
congestion, and the resulting emissions of air toxics such as diesel particulates, which could affect
nearby sensitive receptors if they are present Project J would also result in the accumulation of
trash upstream of the trash boom(s) and in trash processing area(s), which could produce
objectionable odors that affect nearby communities. A more thorough assessment of these
potentially significant impacts would be performed in subsequent tiered NEPA analyses.
Overall, the combined direct and indirect emissions in the U.S. due to operations under the
Supplemental Projects are not expected to exceed GCR de minimis levels or AQIA trigger levels;
however, this would require more thorough assessment in subsequent tiered NEPA analyses.
By reducing transboundary river and marine flows that are contaminated with untreated
wastewater, the Supplemental Projects—including Projects G (New SABTP) and H in Mexico—
would be expected to reduce odors from untreated wastewater and standing water in the Tijuana
River, estuary, and coastal areas.
The potential truck emissions and odor concerns resulting from trash management activities under
Project J could result in transboundary air quality effects on nearby communities in Mexico. A more
thorough assessment would be performed in subsequent tiered NEPA analyses. Otherwise,
operations for the Supplemental Projects in the U.S. would not be expected to result in
transboundary air quality effects on Mexico. Operations for Projects G and H in Mexico would not
be expected to result in transboundary air quality effects on the U.S. other than as described above.
See Section 4.20 (Environmental Justice) regarding disproportionately high and adverse effects due
to air emissions and odor under Alternative 2. See Section 4.21.5 (Cumulative Effects) regarding
significant cumulative air quality impacts that require mitigation, based on a review of the impacts
of other past, present, or reasonably foreseeable actions.
4.11.5 Comparative Analysis of the Alternatives
Table 4-26 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
Two of the evaluated alternatives would result in significant impacts to air quality and odor per the
criteria in Section 4.11.1 (Standards of Significance). Section 5 (Mitigation Measures and
Performance Monitoring) identifies the mitigation measures that would be implemented for the
Core Projects and provides recommended mitigation measures for the Supplemental Projects
(which would be further refined and developed in subsequent tiered NEPA analyses).
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Table 4-26. Comparative Analysis of Effects - Air Quality and Odor
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Minor, short-term impacts from
construction emissions (below GCR de
minimis and AQIA levels)
¦ No objectionable odors or known
impacts to sensitive receptors
Same as Alternative 1, plus the
following:
¦ Minor, short-term impacts due
to increased construction
emissions (below GCR de
minimis and AQIA levels)
Permanent
effects
¦ None
¦ No reduction in
odor from
contaminated
transboundary
flows
¦ Potential significant, long-term impacts
from objectionable odor emissions from
ITP anaerobic digestor process, requiring
odor controls (see Section 5 for
potential mitigation measures)
¦ Minor, long-term impacts from new
criteria pollutant and toxics emissions
from the ITP anaerobic digestor process,
requiring BACT
¦ Minor, long-term impacts from new
stationary source and odor emissions at
the APTP
¦ Minor, long-term increase in mobile
source emissions from commuting and
hauling of waste from ITP and APTP
¦ Overall emissions below GCR de minimis
and AQIA levels
¦ No known impacts to sensitive receptors
¦ Long-term beneficial impacts due to
reduced odor from contaminated
transboundary flows
Same as Alternative 1, plus the
following:
¦ Potential significant, long-term
effects from objectionable odors
and/or impacts to sensitive
receptors due to trash boom
operations (see Section 5 for
potential mitigation measures)
4.12 Climate
4.12.1 Standards of Significance
Impacts to climate would be significant if they were to result in any of the following:
• Inconsistency with the City of San Diego Climate Action Plan.
• Adverse impacts by the project to a specific resource, ecosystem, human community, or
structure, where those impacts would be exacerbated by the foreseeable adverse effects of
climate change.
4.12.2 No-Action Alternative
The No-Action Alternative would have no impacts to regional climate. The existing ITP operations
would continue to generate Scope 1 emissions from emergency generators, Scope 2 emissions
associated with electricity use, and Scope 3 mobile source emissions from employee commuting
and solids waste hauling by truck. The No-Action Alternative would not provide any potential water
reuse opportunities to help reduce competition for increasingly scarce water resources.
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4.12.3 Alternative 1: Core Projects
Under Alternative 1, implementation of Core Projects would have no impacts to regional climate. All
Core Projects would increase Scope 3 emissions from construction vehicles. Additionally,
construction in Mexico for Projects B (Tijuana Canyon Flows to ITP), C (Tijuana Sewer Repairs), and
D (APTP Phase 1) would result in Scope 3 emissions that would create transboundary effects for
GHG emissions. During operation, Project A (Expanded ITP), Options A1 and A2 would decrease
Scope 3 emissions from truck hauling activities associated with solids disposal while Project A,
Option A3 and Project D would increase Scope 3 emissions. Projects A and D would result in
increases in Scope 2 emissions from electricity use and would slightly increase Scope 3 emissions
from increased use of commuter vehicles.
For all Core Projects combined, construction emissions in the U.S. would be no greater than
approximately 3,000 ton/yr C02e with construction activities in Mexico expected to contribute a
much lower amount of C02e. Operational emissions., including Scope 1, 2, and 3 emissions as
estimated using CalEEMod (California Air Pollution Control Officers Association, 2022), would
eventually increase by up to approximately 30,000 ton/yr C02e. The significant majority (96
percent) of this increase would come from combustion of biogas generated by anaerobic digestion
under the 60-MGD design option (Project A, Option A3). That increase would gradually take place
through approximately 2050 as the full capacity of the 60-MGD ITP expansion comes into service in
response to population growth in Tijuana.
Anaerobic digestion of primary and secondary sludge for Project A would generate substantial
amounts of GHG emissions through combustion of produced biogas. Combustion of biogas would
result in increased Scope 1 carbon dioxide emissions and potential emissions of fugitive methane.
Requirements under the State of California GHG cap and trade program could apply if the design
were to incorporate electricity generation and the potential to emit (PTE) associated with onsite
electricity generation were to exceed 25,000 metric ton/yr C02e.
Although aspects of the Core Projects may contribute to specific strategies identified in the City of
San Diego Climate Action Plan (e.g., anaerobic digestion to reduce the volume of sludge sent to
landfill, methane capture from wastewater treatment facilities), ultimately the Core Projects would
be inconsistent with the Climate Action Plan because they would increase GHG emissions directly
and through energy use, transportation, and waste generation.
The Core Projects would have a small to negligible potential to exacerbate drought conditions in
downstream portions of the Tijuana River by reducing the frequency and volume of dry-weather
transboundary river flows to a level that would be more consistent with historical dry-weather flow
patterns (see Section 4.1 [Freshwater and Estuarine Resources]). New U.S.-side infrastructure
associated with Alternative 1 would be far from shore and well upstream of tidally influenced areas
and therefore would not be expected to be affected by sea level rise.
4.12.4 Alternative 2: Core and Supplemental Projects
Under Alternative 2, implementation of the Core Projects would result in the same impacts to
climate as would occur under Alternative 1. Alternative 2 would have no impacts to regional
climate. All Supplemental Projects would increase Scope 3 emissions from construction vehicles.
Additionally, construction in Mexico for Projects G (New SABTP), H (Tijuana WWTP Treated
Effluent Reuse), and I (ITP Treated Effluent Reuse) would result in Scope 3 emissions that would
create transboundary effects for GHG emissions. Operation of Projects E (APTP Phase 2) and J
(Trash Boom[s]) would increase Scope 3 emissions from truck hauling for solids waste and trash
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disposal. Projects E and F would result in an increase in Scope 2 emissions associated with
electricity use and would increase Scope 3 emissions from increased use of commuter vehicles.
Similar to Alternative 1, Alternative 2 would be inconsistent with the City of San Diego Climate
Action Plan because it would increase GHG emissions directly and through energy use,
transportation, and waste generation.
In addition to the impact on dry-weather transboundary river flows described for the Core Projects,
the Supplemental Projects would decrease the cumulative volume of transboundary flows in the
Tijuana River, particularly during smaller wet-weather events (see Section 4.1 [Freshwater and
Estuarine Resources]). Additional study would be needed in subsequent tiered NEPA analyses to
assess whether this could exacerbate saltwater intrusion caused by sea level rise.
Alternative 2 would provide potential water reuse opportunities under Projects H and I (ITP
Treated Effluent Reuse) to help reduce competition for increasingly scarce water resources. New
U.S.-side infrastructure associated with Alternative 2 would be far from shore and well upstream of
tidally influenced areas and therefore would not be expected to be affected by sea level rise.
4.12.5 Comparative Analysis of the Alternatives
Table 4-27 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
Two of the evaluated alternatives would result in significant impacts to climate per the criteria in
Section 4.12.1 (Standards of Significance). Section 5 (Mitigation Measures and Performance
Monitoring) identifies the mitigation measures that would be implemented for the Core Projects
and provides recommended mitigation measures for the Supplemental Projects (which would be
further refined and developed in subsequent tiered NEPA analyses).
Table 4-27. Comparative Analysis of Effects - Climate
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
and
permanent
effects
¦ Continuation of
GHG emissions
generation at
current levels
¦ No
opportunities
for water reuse
to reduce
competition for
water resources
¦ Increases in GHG emissions from
construction and operational activities
of approximately 3,000 ton/yr CChe
and 30,000 ton/yr CChe, respectively
(plus minor CChe emissions from
construction in Mexico)
¦ Generation of substantial amounts of
GHG emissions through combustion of
produced biogas for Project A
¦ Inconsistent with the City of San Diego
Climate Action Plan (see Section 5 for
potential mitigation measures)
¦ Small to negligible potential to
exacerbate drought conditions in
downstream portions of the Tijuana
River
Same as Alternative 1, plus the
following:
¦ Additional GHG emissions from
the Supplemental Projects
¦ Inconsistent with the City of San
Diego Climate Action Plan (see
Section 5 for potential mitigation
measu res)
¦ Removal of a portion of wet-
weather flows for Project F with
unknown effects on saltwater
intrusion downstream
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4.13 Solid and Hazardous Waste
4.13.1 Standards of Significance
Impacts to solid and hazardous waste would be significant if they were to result in any of the
following:
• Generation, handling, or storage of hazardous waste in a manner that does not comply with
applicable regulations.
• Disposal of wastes to a public or private landfill that would detrimentally affect the ability of
the facility to serve existing customers or substantially affect the anticipated lifespan of the
facility.
• Exposure to hazards created by disturbance of an existing contaminated site.
4.13.2 No-Action Alternative
The No-Action Alternative would have no impacts to solid and hazardous waste and would not
reduce quantities of trash and debris deposited in the Tijuana River Valley due to transboundary
flows. The existing ITP would continue to operate and generate approximately 118,100 cubic yards
of solids from wastewater processes that require disposal annually.
4.13.3 Alternative 1: Core Projects
Temporary Effects
Under Alternative 1, implementation of the Core Projects would result in minor, short-term impacts
from construction wastes (e.g., packaging materials, worker refuse) but would be unlikely to
generate any hazardous building materials (e.g., materials contaminated with lead, asbestos, or
polychlorinated biphenyls). Alternative 1 would not result in significant impacts to solid and
hazardous wastes per the criteria in Section 4.13.1 (Standards of Significance). Alternative 1 would
result in no temporary transboundary impacts to solid and hazardous wastes.
Under Project A (Expanded ITP) and, if necessary, Project D (APTP Phase 1), construction activities
and ground disturbance would occur in the southwest corner of the ITP parcel, in an area that was
previously known as the Hofer property. This property once contained contaminated soil, as
discussed in Section 3.13 (Solid and Hazardous Waste). The contaminated soil was cleaned up in
1997 before USIBWC acquired this portion of the ITP parcel. Therefore, Projects A and D would not
result in exposure to known soil contaminants at this site during construction.
Permanent Effects
Under Alternative 1, implementation of the Core Projects would not be expected to generate
hazardous waste aside from typical cleaning and equipment maintenance wastes (e.g., solvents,
oils, and greases), which would be managed and disposed of in accordance with applicable
requirements. As summarized in Table 4-28 and discussed below, operation of expanded
wastewater treatment processes would eventually (by 2050) increase solids waste production by
up to 23,700 cubic yards/yr (80 percent) over existing ITP operations, approximately half of which
would require disposal in the U.S. Alternative 1 would not result in significant impacts to solid and
hazardous wastes per the criteria in Section 4.13.1 (Standards of Significance). Alternative 1 would
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result in a recurring transboundary impact on solid and hazardous wastes for disposal of sludge in
Mexico under Project A (Expanded ITP; see following discussion).
For Projects A and D (APTP Phase 1), the wastewater treatment processes would produce sludge
that would require processing, hauling, and disposal, resulting in recurring effort and cost
Estimated solids production per year for Projects A and D and the change in solids production per
year from the existing conditions are presented in Table 4-28. For Project A, expansion of the ITP
from 25 MGD to 40 MGD (Option Al) or 50 MGD (Option A2) would decrease solids waste
production by approximately 29,200 and 4,800 cubic yards/yr, respectively. For Option A3 (60
MGD), initial operating conditions would result in the same decrease in solids waste production as
would occur under Option A2 (decrease of 4,800 cubic yards/yr); however, by approximately 2050,
plant operations would gradually increase solids waste production by approximately 13,400 cubic
yards/yr as the additional treatment capacity comes into service in response to population growth.
These estimates include incorporation of anaerobic digestion of primary and secondary sludge
which would result in a 46 percent reduction in TSS. This TSS reduction would lead to a decrease in
the amount of solids waste produced under the 40- and 50-MGD design options. Trucks would
transfer the solids to Mexico for either beneficial reuse (e.g., land application) or landfill disposal in
accordance with binational agreements with Mexico. The Punta Bandera disposal facility (where
existing ITP solids waste is disposed of) is nearing capacity and Mexico is evaluating sites for a new
landfill to receive solids waste following closure of the Punta Bandera facility, but information on
specific candidate landfill sites is not available at this time. This waste would not be incinerated.
EPA and USIBWC anticipate that evolving binational discussions would influence the disposal
location for solids waste from Project A.
For Project D, operation of the new APTP (Phase 1) would increase solids waste production by
approximately 10,300 cubic yards/yr (over current conditions). Solids would be disposed of at a
viable regional disposal facility in the U.S.,63 such as Sycamore Landfill or Otay Landfill, which are
both operated by Republic Services (see Table 3-12 in Section 3.13 [Solid and Hazardous Waste]).
Both these facilities are expected to have capacity to receive annual loads of approximately 10,000
to 16,000 cubic yards of solids for disposal without impacting the long-term operation of the
facilities. Disposal of wastes at these landfills would not detrimentally affect the ability of the
facilities to serve existing customers or affect the lifespan of the facilities. It is possible that the
solids from Project D would be split between the two facilities, depending on discussions with
Republic Services when negotiating a disposal agreement. The solids waste would be subject to
sampling requirements in accordance with the applicable acceptance guidelines of the facility.
While Projects A and D would increase the number of personnel at the ITP parcel and thus slightly
increase the associated domestic waste hauling and disposal requirements, this would not be
expected to introduce any new sources of trash loadings into the Tijuana River Valley.
While implementation of the Core Projects would be expected to reduce the frequency of dry-
weather transboundary river flows, it would not reduce the frequency of wet-weather
63 This analysis assumes that solids waste from the proposed APTP would be disposed of in the U.S. since this
is currently the only viable option due to the absence of a binational agreement. Disposing of waste in Mexico
that is produced in the U.S. would require additional treaty negotiations. If future treaty minutes result in a
change to this arrangement, EPA and/or USIBWC would reevaluate the location of sludge disposal and
consider the potential benefits or impacts of transferring such disposal from landfills in the U.S. to those in
Mexico.
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transboundary river flows that convey substantial amounts of trash and debris into the Tijuana
River Valley. Therefore, Core Projects would not reduce trash and debris during these wet-weather
conditions. See Section 4.1 (Freshwater and Estuarine Resources) for further discussion.
Table 4-28. Summary of Estimated Changes in Wastewater Process Solids Production under
Alternative 1
Project
Plant
Landfill
Location
Solids Production (cubic yards/yr)f
Total
Change from
Current Conditions
Current conditions a
ITP
Mexico
118,100
N/A
Project A, Option A1 (Expand to 40 MGD) onlyc
ITP
Mexico
88,900
-29,200
Project A, Option A2 (Expand to 50 MGD) only bc d
ITP
Mexico
113,300
-4,800
Project A, Option A3 (Expand to 60 MGD) only b c e
ITP
Mexico
131,500
13,400
Project D (35 MGD) onlyc
APTP
(Phase 1)
U.S.
10,300
10,300
Alternative 1 maximum (Projects A [Option A3] +
D)
-
-
141,800
23,700
a - Current conditions were calculated using data from January 2016 through January 2022.
b - Reflects UP treatment of inflows resulting from Project B (Tijuana Canyon Flows to ITP).
c - Reflects ITP treatment of inflows resulting from Project C (Tijuana Sewer Repairs).
d - Reflects projected operations in 2030, when the 50-MGD ITP would be operating at full capacity based on
estimated population growth in Tijuana.
e - Reflects projected operations in 2050, when the 60-MGD ITP would be operating at full capacity based on
estimated population growth in Tijuana,
f- Represents sediments and sludge dry solids.
4.13.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Under Alternative 2, implementation of the Core Projects would result in the same minor, short-
term impacts to solid and hazardous waste as would occur under Alternative 1. The general solid
and hazardous waste impacts discussed above for Core Projects (e.g., that the Core Projects would
be expected to produce minor construction wastes but no hazardous building materials) would be
applicable to the Supplemental Projects. Alternative 2 would not result in significant impacts to
solid and hazardous wastes per the criteria in Section 4.13.1 (Standards of Significance). Alternative
2 would result in no temporary transboundary impacts to solid and hazardous wastes.
Permanent Effects
Under Alternative 2, implementation of the Core Projects would result in the same impacts to solid
and hazardous waste as would occur under Alternative 1. Implementation of the Supplemental
Projects would not be expected to generate hazardous waste aside from typical cleaning and
equipment maintenance wastes (e.g., solvents, oils, and greases), which would be managed and
disposed of in accordance with applicable requirements. As discussed below, implementation of the
Supplemental Projects would create additional solid waste disposal requirements in both the U.S.
and Mexico. Alternative 2 would not result in significant impacts to solid and hazardous wastes per
the criteria in Section 4.13.1 (Standards of Significance). Alternative 2 would result in the same
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recurring transboundary impact on solid and hazardous waste as described for Alternative 1
(expanded ITP solids disposal in Mexico).
Supplemental Projects with wastewater treatment processes that would produce solids include
Projects E (APTP Phase 2) and G (New SABTP). For Project E, expanding the APTP (Phase 2) would
increase solids waste production by approximately 5,700 cubic yards/yr over Phase 1 solids waste
production, for a total of 16,000 cubic yards/yr. For Project E, solids waste would likely be disposed
of in the U.S. at the same regional disposal facility identified for Project D (Phase 1): that is, at either
Sycamore Landfill or Otay Landfill (see potential facilities in Table 3-12 in Section 3.13 [Solid and
Hazardous Waste]). The solids waste disposal for Project E would not detrimentally affect the
ability of either facility to serve existing customers or affect the lifespan of the facility. Project G
would include production of solids waste at the new SABTP in Mexico. Solids waste from Project G
would be disposed of either at Punta Bandera or at a viable regional facility in Mexico (not
incinerated); it would not be disposed of in the U.S.
Project J (Trash Boom[s]) would capture floatable trash in the main channel and would reduce
trash and debris deposits in the Tijuana River Valley. Based on available information on the
performance of similar existing trash booms in Goat Canyon, it is assumed that the trash boom(s)
would trap 75 percent of the trash load in the main channel. This trapping efficiency, when applied
to the annual trash load discussed in Section 3.13 (Solid and Hazardous Waste) (15,000 cubic
yards), results in an estimate that the trash boom(s) would capture 11,300 cubic yards of trash
annually. The trash boom(s) in the main river channel would not be able to capture trash or debris
that is deposited farther upstream or that flows under or over the trash boom(s) and would not be
effective in capturing any trash entering the Tijuana River Valley downstream of the boom
location(s), such as at illegal dumping sites near Dairy Mart Road. In a subsequent tiered NEPA
analysis, further studies would be needed to refine the estimates of trash loads in wet-weather
transboundary flows in the main channel; the expected trapping efficiency of the engineered
boom(s); and the resulting amount of trash and debris requiring extraction, processing, hauling,
and disposal at an appropriate disposal facility in the U.S., such as Sycamore Landfill or Otay
Landfill (see Table 3-12 in Section 3.13 [Solid and Hazardous Waste]).
4.13.5 Comparative Analysis of the Alternatives
Table 4-29 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
None of the evaluated alternatives would result in significant impacts to solid and hazardous waste
per the criteria in Section 4.13.1 (Standards of Significance). Section 5 (Mitigation Measures and
Performance Monitoring) identifies the mitigation measures that would be implemented for the
Core Projects and provides recommended mitigation measures for the Supplemental Projects
(which would be further refined and developed in subsequent tiered NEPA analyses).
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Table 4-29. Comparative Analysis of Effects - Solid and Hazardous Waste
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Minor, short-term impacts from
production of construction waste
¦ Unlikely to generate any hazardous
building materials
Same as Alternative 1
Permanent
effects
¦ None
¦ No reduction
in quantities
of trash and
debris
deposited in
the Tijuana
River Valley
¦ Minor, long-term impacts from
typical cleaning and equipment
maintenance wastes, managed in
accordance with applicable
requirements
¦ Long-term effects from increase in
solids production of up to 23,700
cubic yards/yr over existing ITP
operations, including:
- 10,300 cubic yards/yr requiring
disposal in the U.S.
- Long-term effects from
transboundary impact:
substantial decrease or minor
increase (depending on Project A
design option) in solids requiring
disposal in Mexico
¦ No reduction in quantities of trash
and debris deposited in the Tijuana
River Valley
Same as Alternative 1, plus the
following:
¦ Long-term impacts from additional
increase in solids production of up to
5,700 cubic yards/yr requiring disposal
in the U.S.
¦ Long-term impacts from capture of
approximately 11,300 cubic yards of
trash and debris per year requiring
disposal in the U.S., and associated
long-term beneficial effects from
reduction in trash and debris
deposited in the Tijuana River Valley
4.14 Energy
4.14.1 Standards of Significance
Impacts to energy would be significant if they were to result in any of the following:
• Exceedance of existing electrical infrastructure capacity, resulting in the demand for new or
altered public electrical service facilities or utilities that would have significant environmental
impacts.
• Use of excessive amounts of fuel, energy, or power that would negatively affect the availability
of resources for public services and utilities.
4.14.2 No-Action Alternative
The No-Action Alternative would not have any impacts on energy.
4.14.3 Alternative 1: Core Projects
Implementation of Core Projects under Alternative 1 would result in increased energy use
associated with construction and O&M activities. Operation of all Core Projects would potentially
increase electricity demand by approximately 26.9 GWh/yr in the U.S. but would include the
opportunity to offset a portion, or all, of this increase through electrical generation using biogas, as
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discussed below. Core Projects would not be expected to negatively affect energy availability for
public services. Operation of certain Core Projects may require upgrades to electrical utilities, but
modifications would be minor and would not be expected to have significant environmental
impacts. Therefore, implementation of Core Projects would not result in significant impacts to
energy resources per the criteria in Section 4.14.1 (Standards of Significance).
Construction of all Core Projects would result in direct consumption of fossil fuels associated with
construction equipment (e.g., gasoline, diesel) as well as other irretrievable uses of energy such as
the embodied energy of construction materials. However, construction activities would be short-
term and would not be expected to exceed electrical infrastructure capacity or negatively affect the
availability of energy resources for public services and utilities.
Project A (Expanded ITP) operations under initial operating conditions would increase electrical
demand by approximately 12 to 19 GWh/yr, depending on the design option. However, eventual
operating conditions for Option A3 would include treatment of up to 60 MGD (over the course of a
20-year period from 2030 to 2050) as the full expansion capacity comes into service to treat
additional sewage from population growth in Tijuana. Expansion to 60 MGD would increase
electrical demand by an additional 6 GWh/yr over this time period. Project D (APTP Phase 1)
operations would increase electrical demand by approximately 1.9 GWh/yr. Table 4-30
summarizes the estimated changes in electricity demand for Projects A and D. As discussed in
Section 4.15 (Public Services and Utilities), potential minor, localized modifications to electricity
lines and transformers near the ITP may be required to service new facilities constructed under
Projects A and D, but modifications would not result in adverse environmental impacts. EPA and/or
USIBWC would coordinate with SDG&E to confirm the necessary scope of these upgrades. The
designs for Projects A and D would also include flexibility for incorporating energy conservation
equipment.
The proposed conveyance pipelines for Project B (Tijuana Canyon Flows to ITP) would be gravity-
fed and require minimal or no electrical demand. Project B, Option B3 (Connect to Existing Canyon
Collector System) would potentially result in a slight increase in the electrical demand at Hollister
Street pump station needed to pump additional flows to the ITP.
The proposed anaerobic digestion of primary and secondary sludge under Project A would provide
an opportunity to offset grid electricity use through biogas combustion. Depending on the design
option, anaerobic digestion would produce approximately 0.89 to 1.22 million cubic feet per day
(Mcf/day) of biogas. This corresponds to 0.58 to 0.79 Mcf/day of methane with an energy
equivalent of 760 to 1,040 million British thermal units per day and a capacity of 2.6 to 3.4
megawatts (PG Environmental, 2021c). Biogas from the anaerobic digester would be produced on a
continuous basis—i.e., up to 8,760 hours per year without accounting for occasional pauses during
maintenance of the digesters or process upsets. At this rate, with a biogas-fueled reciprocating
engine also operating continuously to generate electricity, this system would be capable of
generating a theoretical maximum of approximately 23 GWh/yr (for the 40-MGD expanded ITP) or
29 GWh/yr (for the 60-MGD expanded ITP). This system would have the potential to fully offset the
increased electricity demand at the ITP and APTP shown in Table 4-30, with the possibility of also
generating surplus electricity to offset a portion of the electricity demand from continued operation
of the existing ITP facilities.
Fossil fuel consumption for trucking of solids waste for disposal would decrease under
implementation of Project A, Options A1 (Expand to 40 MGD) andA2 (Expand to 50 MGD). Fossil
fuel consumption for trucking of solids waste for disposal would increase under implementation of
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Project A, Option A3 (Expand to 60 MGD), and Project D. Negligible increases in staff commuting
from implementation of Alternative 1 would also result in negligible to minor increases in fossil fuel
consumption. See Sections 4.13 (Solid and Hazardous Waste) and 4.17 (Transportation) for
additional discussion.
Implementation of the Core Projects would reduce energy use in Mexico by reducing the use of
pump stations under Projects B and D. By improving the collection of wastewater in Mexico and
providing increased treatment capacity in the U.S., the Core Projects would reduce the volume of
wastewater requiring treatment at SABTP and thus reduce electricity demand at SABTP.
Construction and O&M of project components in Mexico would have no transboundary effects on
energy in the U.S. because components in Mexico would obtain electricity and any required energy
demands from sources in Mexico.
Table 4-30. Summary of Estimated Increases in Electricity Demand for Core Projects
Project
Plant
Electricity Demand (GWh/yr)f
Current conditions a
ITP
20
Project A, Option A1 (Expand to 40 MGD) onlyc
ITP
+12
Project A, Option A2 (Expand to 50 MGD) only bc d
ITP
+19
Project A, Option A3 (Expand to 60 MGD) only b c e
ITP
+25
Project D (35 MGD) onlyc
APTP (Phase 1)
+1.9
Alternative 1 maximum (Projects A [Option A3] +
D)
-
+26.9
a - Current conditions were calculated using electrical demand data from February 25, 2020, to August 25, 2020.
b - Reflects UP treatment of inflows resulting from Project B (Tijuana Canyon Flows to ITP).
c - Reflects ITP treatment of inflows resulting from Project C (Tijuana Sewer Repairs).
d - Reflects projected operations in 2030, when the 50-MGD ITP would be operating at full capacity based on
estimated population growth in Tijuana.
e - Reflects projected operations in 2050, when the 60-MGD ITP would be operating at full capacity based on
estimated population growth in Tijuana.
f-Values do not reflect the energy savings to Mexico resulting from having to treat less wastewater at the
SABTP.
4.14.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Implementation of Alternative 2 would result in effects on energy similar to those under Alternative
1; however, Alternative 2 would require a greater amount of energy for construction and O&M of
Supplemental Projects. Alternative 2 would not be expected to require any upgrades to electrical
utilities that would have significant environmental impacts or result in negative effects on energy
availability for public services and utilities. Therefore, Alternative 2 would not result in significant
impacts to energy resources per the criteria in Section 4.14.1 (Standards of Significance).
For Project E (APTP Phase 2), expansion of the APTP from 35 MGD to 60 MGD would increase
electricity demand to power additional treatment processes. The new screw pumps required for
operation of Project F (U.S.-side River Diversion to APTP) and the new pump station required for
operation of Project I (ITP Treated Effluent Reuse) would also create additional electricity demand.
However, the designs for Projects E and F would include flexibility for incorporating energy
conservation equipment and strategies, such as shutting down when not providing sufficient
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benefits. Providing electrical utility services to the new facilities constructed under Projects E and
F, if necessary, would potentially require modifications to electrical lines and/or transformers that
serve the ITP area. Any public utility modification would be minor and localized, and would not
result in adverse physical impacts.
The Supplemental Projects would lead to increased fossil fuel consumption from trucking of the
following wastes: solids waste generated from operation of Project E, sediments removed from the
intake structure during maintenance of Project F, and trash removed during O&M of Project J
(Trash Boom[s]). Project J would potentially result in substantial increases in fossil fuel
consumption from trucking. The magnitude of the increases would be dependent on the trash
capture efficiency of the boom(s) and the frequency of hauling activities, which would be further
defined and analyzed in subsequent tiered NEPA analyses. Minor increases in staff commuting
under implementation of Alternative 2 would also result in minimal increases in fossil fuel
consumption. Fossil fuel use from Alternative 2 would not be expected to affect the availability of
energy resources for public services and utilities since fossil fuel sources are readily available in the
region. See Sections 4.13 (Solid and Hazardous Waste) and 4.17 (Transportation) for additional
discussion.
Project G (New SABTP) would potentially reduce energy use in Mexico by shutting down the
existing ineffective SABTP and replacing it with a smaller, more efficient operation. Project I would
also potentially offset the existing use of potable water, thus also offsetting the associated energy
use required for the treatment of this potable water in Mexico. Project H (Tijuana WWTP Treated
Effluent Reuse) would also potentially offset energy use by reducing the amount of treated effluent
undergoing an unnecessary second round of treatment. By reducing the amount of treated effluent
in the Tijuana River, Project H would increase the energy efficiency of downstream components of
the Tijuana River diversion system (i.e., PB-CILA, PB1-A, PB1-B, and either the SABTP or ITP) by
freeing up energy to treat the remaining flows.
No other components of Alternative 2 would result in effects on energy in the U.S.
4.14.5 Comparative Analysis of the Alternatives
Table 4-31 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
None of the evaluated alternatives would result in significant impacts to energy per the criteria in
Section 4.14.1 (Standards of Significance). Section 5 (Mitigation Measures and Performance
Monitoring) identifies the mitigation measures that would be implemented for the Core Projects
and provides recommended mitigation measures for the Supplemental Projects (which would be
further refined and developed in subsequent tiered NEPA analyses).
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Table 4-31. Comparative Analysis of Effects - Energy
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Minor, short-term impacts from direct
consumption of fossil fuels associated
with construction equipment and
direct use of embodied energy of
construction materials
¦ No exceedance of electrical
infrastructure capacity or negative
effects on energy availability for public
services and utilities
Same as Alternative 1, plus the
following:
¦ Minor, short-term impact from slight
increase in energy use due to
construction of additional
infrastructure
Permanent
effects
¦ None
¦ Minor, long-term impacts from
increasing electricity demand by 26.9
GWh/yr under eventual operating
conditions
¦ Potential minor, localized
modifications to electrical utilities near
the ITP that would not result in
adverse environmental impact
¦ No negative effects on energy
availability for public services and
utilities
¦ Potential beneficial impact from
opportunity to offset grid electricity
through biogas combustion
¦ Potential minor, long-term effect from
minimal increase in fossil fuel
consumption for hauling solids waste
and staff commuting
¦ Potential reductions in energy use and
electrical demand in Mexico
Same as Alternative 1, plus the
following:
¦ Minor, long-term impact from
increase in electricity demand for
expanded APTP, plus additional
electricity demand for new screw
pumps and pump station
¦ Minor, long-term impact from
increase in fossil fuel consumption for
staff commuting and extracting and
hauling solids waste, sediments, and
trash, but with no associated effect on
energy availability for public services
and utilities
¦ Potential long-term beneficial effects
from energy offsets through reuse of
treated effluent
4.15 Public Services and Utilities
4.15.1 Standards of Significance
Impacts to public services and utilities would be significant if they were to result in any of the
following:
• Exceedance of existing public infrastructure capacity, resulting in the demand for new or
altered public service facilities or utilities that would have adverse physical impacts or
conflict with the community plans or goals.
• Use of excessive amounts of fuel, energy, power, or water that would negatively affect the
availability of resources for public services and utilities (e.g., water use that results in
insufficient water supplies available to serve reasonably foreseeable future development
during normal, dry, and multiple dry years).
• Introduction of an activity or infrastructure modification that impedes or conflicts with
existing public services.
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4.15.2 No-Action Alternative
The No-Action Alternative would have no impacts to public services and utilities. Transboundary
flows would continue to hinder CBP and Navy activities as described in Section 1.3.2 (Impacts of
Contaminated Transboundary Flows).
4.15.3 Alternative 1: Core Projects
Temporary Effects
Under Alternative 1, implementation of certain Core Projects would result in minor, short-term
effects on public services and utilities to accommodate construction activities. However,
construction-related impacts to public services and utilities, if they could not be avoided, would be
short-term and localized. In addition, construction activities for the Core Projects would not use
excessive amounts of fuel, energy, power, or water and thus would not affect the availability of
resources for public services and utilities.
As discussed in Section 4.13 (Solid and Hazardous Waste), waste generated from construction
activities would require short-term use of public landfill(s), but sufficient capacity would be
available and this increase in demand would not require the construction of new disposal facilities.
As discussed in Section 4.17 (Transportation), Projects A (Expanded ITP), B (Tijuana Canyon Flows
to ITP), and D (APTP Phase 1) would incorporate traffic control measures during temporary road
closures or detours. These measures would ensure that construction activities would not impede or
conflict with emergency services, CBP activities, or public access to community facilities.
Pipeline installation under the U.S.-Mexico border in Smuggler's Gulch for Project B and from PB-
CILA to the new APTP for Project D would be coordinated with CBP to ensure construction
activities would not affect CBP operations (e.g., monitoring access points in the canyons and
performing security functions).
Construction activities in Mexico under Alternative 1 would not use public services or utilities in
the U.S., and short-term transboundary impacts from construction in Mexico would not impede or
conflict with emergency services, CBP activities, or public access to community facilities.
Permanent Effects
Under Alternative 1, implementation of the Core Projects would not be expected to exceed existing
infrastructure capacity, result in the demand for new public services or utilities, or result in
population growth that would strain the services of, or public access to, emergency services, school
systems, or other community facilities. Operation of infrastructure associated with Core Projects
would not result in the use of excessive amounts of fuel, energy, power, or water and thus would
not affect the availability of resources for public services and utilities.
As discussed in Section 4.13 (Solid and Hazardous Waste), solid waste produced under Project D
operations (APTP Phase 1) would require long-term use of public landfill(s), but sufficient capacity
would be available and this increase in demand would not require the construction of new disposal
facilities. Solid waste produced under Project A operations (Expanded ITP) would be hauled to
Mexico for disposal and therefore would not impact public landfill availability in the U.S.
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Wastewater treatment operations under Projects A and D would result in minor long-term
increases in water and energy use, traffic along Dairy Mart Road, and employment. These increases
would be well within the capacity of existing utility infrastructure and would not be expected to
impact public access to emergency services (e.g., by hindering emergency vehicles) or strain the
services of school systems or other community facilities. See Sections 4.1 (Freshwater and
Estuarine Resources), 4.14 (Energy), 4.17 (Transportation), and 4.19 (Socioeconomics) for
additional discussion.
Providing utility services to the new facilities constructed under Projects A and D would potentially
require modifications to electrical lines, transformers, and other localized public utilities that serve
the ITP area. Any public utility modification would be minor and localized, and would not result in
adverse physical impacts.
Alternative 1 would support the public service missions of CBP and the Navy by reducing impacts
to their operations caused by contaminated transboundary flows. Specifically, Projects B and C
(Tijuana Sewer Repairs) would potentially reduce the volume and frequency of dry-weather
transboundary flows in Goat Canyon and Smuggler's Gulch. Project C would also potentially reduce
transboundary flows of untreated wastewater in Stewart's Drain. Therefore, these projects would
potentially improve CBP's ability to safely monitor and maintain infrastructure in these areas. By
reducing discharges of untreated wastewater to the Pacific Ocean, Core Projects would help to
reduce the frequency of coastal water advisories and the associated impacts to Navy training
activities described in Section 1.3.2 (Impacts of Contaminated Transboundary Flows).
No other components of Core Projects would result in permanent effects on public services and
utilities in the U.S.
4.15.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Under Alternative 2, construction activities would result in minor, short-term effects on public
services and utilities similar to those under Alternative 1; however, Alternative 2 would require a
greater amount of construction for implementation of Supplemental Projects. Implementation of
the Core Projects would result in the same impacts to public services and utilities as would occur
under Alternative 1. Construction-related impacts to public services and utilities, if they could not
be avoided, would be short-term and localized. Construction activities for Alternative 2 would not
use excessive amounts of fuel, energy, power, or water and thus would not affect the availability of
resources for public services and utilities.
As discussed in Section 4.13 (Solid and Hazardous Waste), waste generated from construction
activities would require short-term use of public landfill(s)—slightly more than for Core Projects,
due to the greater amount of construction—but sufficient capacity would be available and this
increase in demand would not require the construction of new disposal facilities.
As discussed in Section 4.17 (Transportation), construction activities in the U.S. would incorporate
traffic control measures if temporary public road closures or detours were required. These
measures would ensure that construction activities would not impede or conflict with emergency
services or public access to community facilities.
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Certain construction activities would be coordinated with CBP to ensure that the activities do not
affect CBP operations (e.g., performing security functions and conducting vegetation management).
These construction activities include pipeline installation under the U.S.-Mexico border from the
ITP to PB1-B for Project I (ITP Treated Effluent Reuse), installation of the river diversion structure
for Project F (U.S.-side River Diversion to APTP), and installation of the trash boom(s) for Project J
(Trash Boom[s]) in the Tijuana River main channel near the U.S.-Mexico border. Impacts to CBP
operations from Projects F and J would be dependent on the location and design of the river
diversion and trash boom(s), which would be further defined and analyzed in subsequent tiered
NEPA analyses.
Construction activities in Mexico under Alternative 2 would not use public services and utilities in
the U.S., and short-term transboundary impacts from construction in Mexico would not impede or
conflict with emergency services, CBP activities, or public access to community facilities.
Permanent Effects
Under Alternative 2, implementation of the Core Projects would result in the same minor, long-term
effects as would occur under Alternative 1. Alternative 2 would not be expected to exceed existing
infrastructure capacity, result in the demand for new public services or utilities, or result in
population growth that would strain the services of, or public access to, emergency services, school
systems, or other community facilities. Operation of infrastructure associated with Alternative 2
would not result in the use of excessive amounts of fuel, energy, power, or water and thus would
not affect the availability of resources for public services and utilities. Certain Supplemental
Projects could significantly affect CBP operations if their impacts were not appropriately
considered in coordination with CBP during project planning and design.
As discussed in Section 4.13 (Solid and Hazardous Waste), Alternative 2 would require long-term
use of public landfill(s) due to solid waste produced under Project E operations (APTP Phase 2),
Project F maintenance (U.S.-side River Diversion to APTP), and Project J maintenance (Trash
Boom[s]), in addition to the Core Projects. Sufficient capacity would be expected to be available, and
the increase in demand would not require the construction of new disposal facilities.
Wastewater treatment operations under Project E and maintenance activities under Project J would
result in minor long-term increases in water and energy use, traffic along Dairy Mart Road, and/or
employment. These increases, in addition to those of the Core Projects, would be well within the
capacity of existing utility infrastructure and would not be expected to impact public access to
emergency services (e.g., by hindering emergency vehicles) or strain the services of school systems
or other community facilities. See Sections 4.1 (Freshwater and Estuarine Resources), 4.14
(Energy), 4.17 (Transportation), and 4.19 (Socioeconomics) for additional discussion.
Providing utility services to the new facilities constructed under Projects E and F, if necessary,
would potentially require modifications to electrical lines, transformers, and other localized public
utilities that serve the ITP area. Any public utility modification would be minor and localized, and
would not result in adverse physical impacts.
Certain Supplemental Projects, if not properly planned and designed, would potentially interfere
with CBP's ability to perform patrols and execute their mission. Specifically, Projects F and J would
include new infrastructure and O&M activities in the Tijuana River main channel in an area where
CBP currently performs regular vegetation maintenance. To conduct maintenance activities near
the U.S.-Mexico border for Project J, heavy vehicles would require access to the trash boom(s) and
trash processing area(s) on a recurring basis, which would potentially interfere with CBP
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operations. Implementation of Project J would result in the accumulation of trash upstream of the
boom(s) or in the trash processing area(s), and these accumulations of trash would potentially
affect field conditions, cause occupational safety concerns, and cause surveillance and access issues
for CBP personnel. To minimize impacts to CBP operations and mission, coordination would be
required, potentially including revisions to the 1980 Memorandum of Understanding between
USIBWC and CBP. Potential impacts to CBP operations, and the design considerations necessary to
reduce these potential impacts, would be dependent on the location and design of the river
diversion, trash boom(s), and trash processing area(s), and on the capture efficiency of the trash
boom(s), all of which would be further defined and analyzed in subsequent tiered NEPA analyses
with input from CBP.
The public service mission benefits to CBP and the Navy under Alternative 2 would include those
described for the Core Projects, plus further benefits to Navy training activities due to reductions in
discharges of untreated wastewater to the Pacific Ocean as described in Section 1.3.2 (Impacts of
Contaminated Transboundary Flows).
No other components of Alternative 2 would result in permanent effects on public services and
utilities in the U.S.
4.15.5 Comparative Analysis of the Alternatives
Table 4-32 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
One of the evaluated alternatives would, in the absence of mitigation, potentially result in
significant impacts to public services and utilities per the criteria in 4.15.1 (Standards of
Significance). Section 5 (Mitigation Measures and Performance Monitoring) identifies the mitigation
measures that would be implemented for the Core Projects and provides recommended mitigation
measures for the Supplemental Projects (which would be further refined and developed in
subsequent tiered NEPA analyses).
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Table 4-32. Comparative Analysis of Effects - Public Services and Utilities
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Minor, short-term impacts to public
services and utilities (in coordination
with CBP) to accommodate
construction activities
¦ No public infrastructure capacity
exceedance, excessive use of public
resources, or impedance of public
services
¦ No short-term impacts from public
landfill use (within capacity)
¦ Minor, short-term impacts due to
potential road closures or detours
during construction
Same as Alternative 1, plus the
following:
¦ No short-term impacts from
additional public landfill use (within
capacity)
¦ Additional minor, short-term impacts
due to potential road closures or
detours during construction
¦ Additional potential for localized
interference with CBP operations
during construction
Permanent
effects
¦ None
¦ No reduction in
impacts of
contaminated
transboundary
flows on CBP
and Navy
public service
missions
¦ Minor, long-term impacts to public
services and utilities to
accommodate O&M activities
¦ No public infrastructure capacity
exceedance, excessive use of public
resources, or impedance of public
services
¦ No long-term impacts from public
landfill use (within capacity)
¦ Potential minor, localized
modifications to existing public
utilities that would have no adverse
physical impacts
¦ Long-term beneficial impacts from
reduction in contaminated
transboundary flows that interfere
with CBP and Navy public service
missions
Same as Alternative 1, plus the
following:
¦ Potential significant, long-term
impact from impedance to CBP
operations due to U.S.-side river
diversion and trash boom(s) (see
Section 5 for potential mitigation
measu res)
¦ No long-term impacts from
additional public landfill use (within
capacity)
¦ Long-term beneficial effect from
further reductions in contaminated
transboundary flows that interfere
with CBP and Navy public service
missions
4.16 Public Health and Safety
4.16.1 Standards of Significance
Impacts to public health and safety would be significant if they were to include any of the following:
• Increase in risk of wildland fires or inability to meet applicable fire codes.
• Increase in unsafe field conditions for CBP personnel.
• Exacerbation of water quality issues at public beaches in the U.S.
• Introduction of new environments (e.g., standing water) that could increase human
exposure to vectors that are capable of transmitting diseases.
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4.16.2 No-Action Alternative
The No-Action Alternative would include the continuation of existing impacts to public health and
safety that are currently resulting from contaminated transboundary flows from Tijuana (see
Section 1.3 [Causes and Impacts of Contaminated Transboundary Flows from Tijuana] and Section
3.1 [Freshwater and Estuarine Resources]). These impacts include coastal discharges of largely
untreated wastewater (sewage) along the Pacific Ocean coast in the U.S. that expose public beaches
and recreational users to unsafe conditions and result in beach closures. Transboundary flows
currently carry trash from Tijuana throughout the Tijuana River Valley, which presents human
health concerns by way of exposures to toxic substances and ponding that can encourage spread of
disease vectors. These conditions also present health risks to U.S. military and border security
personnel.
These impacts would persist unabated and would worsen over time as wastewater infrastructure in
Tijuana continues to deteriorate and the population continues to grow without access to adequate
wastewater treatment infrastructure. The No-Action Alternative would therefore exacerbate
current unsafe field conditions for CBP personnel and water quality issues at public beaches, which
would be a significant impact per the criteria in Section 4.16.1 (Standards of Significance).
4.16.3 Alternative 1: Core Projects
Under Alternative 1, implementation of the Core Projects would include development in areas
susceptible to hazardous conditions, such as in Very High Fire Hazard Severity Zones and areas
susceptible to landslides. Development in these areas would be consistent with applicable design
codes to reduce risks. For additional information associated with these individual hazard areas, see
Sections 4.1 (Freshwater and Estuarine Resources), 4.6 (Geological Resources), and 4.12 (Climate).
A discussion of water quality impacts that affect beach closures and a discussion of impacts to CBP
ability to perform patrols and execute their mission can be found in Sections 4.2 (Marine Waters)
and 4.15 (Public Services and Utilities), respectively. Construction activities would not result in any
public health and safety impacts. Alternative 1 would not result in significant impacts to public
health and safety per the criteria in Section 4.16.1 (Standards of Significance).
Drawing from the modeled relationship (presented in Feddersen etal. (2021)) between discharges
of untreated wastewater via SAB Creek and resulting beach impacts, EPA and USIBWC interpolated
the expected tourist (dry) season impacts at regional beaches that would result from
implementation of the Core Projects (see Section 4.2 [Marine Waters]). Based on EPA's analysis, full
implementation of the Core Projects would immediately lead to significant reductions in water
quality-driven human health impacts at regional beaches. The Core Projects would be expected to
reduce Nm at Imperial Beach by up to 79 percent upon startup of the new treatment facilities. The
Core Projects would be expected to reduce public health and safety impacts at the beaches and at
Naval facilities in San Diego County, including the Navy SEALs training facility in Coronado,
California. By reducing the amount of contaminated water released into the ocean, the Core Projects
would further be expected to reduce potential human health impacts from airborne exposure to
pathogens from aerosolized ocean water.
Projects A and C would also improve field conditions for CBP personnel by reducing contaminated
transboundary flows near canyon flow diversion structures, the border fence, and other border
infrastructure that are patrolled and maintained by CBP personnel. Construction and operation of
the Core Projects would not increase standing water that could provide breeding areas for
mosquitoes.
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4.16.4 Alternative 2: Core and Supplemental Projects
Under Alternative 2, implementation of the Core Projects would result in the same impacts to public
health and safety as would occur under Alternative 1. Implementation of the Supplemental Projects
would include development in the same areas susceptible to hazardous conditions that are
identified above for the Core Projects, with the addition of development in a floodway for Projects F
(U.S.-side River Diversion to APTP) and J (Trash Boom[s]). For additional information associated
with this individual hazard area, see Section 4.3 (Floodplains). Construction activities would not
result in any public health and safety impacts.
Implementation of Project G would result in further reductions in water quality-driven human
health impacts at regional beaches by providing treatment capacity for all remaining wastewater
discharges via SAB Creek (see Section 4.2 [Marine Waters]). EPA and USIBWC estimate that
implementation of all Core Projects plus Project G would eliminate more than 99 percent of the
modeled BIF for beaches in southern San Diego County. This would substantially improve water
quality and thus reduce public health and safety impacts at the beaches and at Naval facilities in San
Diego County, including the Navy SEALs training facility in Coronado, California. This would further
reduce potential human health impacts by lowering the amount of pathogens present in aerosolized
ocean water.
Project J would introduce a new feature (trash boom[s]) near the border that requires regular
security inspections by CBP personnel. Exposure to trash, which may contain toxic substances,
wastes, or chemicals, would potentially present health and safety risks to CBP personnel during
border security activities, resulting in a significant impact per the criteria in Section 4.16.1
(Standards of Significance). Coordination with CBP during subsequent tiered NEPA analyses for
Project J would be needed to identify ways to reduce CBP health risks associated with maintaining
security at the trash boom(s).
Construction and operation of Projects F and J would introduce new environments that could
contain standing water and create conditions conducive to the breeding and multiplication of
disease vectors (e.g., mosquitoes, rodents, stray dogs) that could impact public health, resulting in a
significant impact per the criteria in Section 4.16.1 (Standards of Significance).
See Section 4.20 (Environmental Justice) regarding disproportionately high and adverse effects due
to public health and safety impacts under Alternative 2.
4.16.5 Comparative Analysis of the Alternatives
Table 4-33 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
Two of the evaluated alternatives would potentially result in significant impacts to public health
and safety per the criteria in Section 4.16.1 (Standards of Significance). Section 5 (Mitigation
Measures and Performance Monitoring) identifies the mitigation measures that would be
implemented for the Core Projects and provides recommended mitigation measures for the
Supplemental Projects (which would be further refined and developed in subsequent tiered NEPA
analyses).
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Table 4-33. Comparative Analysis of Effects - Public Health and Safety
Effect
No-Action
Alternative 1 (Core Projects)
Alternative 2
Category
Alternative
(Core and Supplemental Projects)
Temporary
¦ None
¦ No short-term impacts from
Same as Alternative 1
effects
construction activities
Permanent
¦ Significant, long-
¦ Minor, long-term impacts from
Same as Alternative 1, plus the
effects
term impact from
increasing staff/facilities in areas
following:
exacerbation of
susceptible to very high fire
¦ Additional minor, long-term impacts
unsafe field
severity and landslides
from increasing staff/facilities in areas
conditions for
¦ Long-term beneficial effects
susceptible to high fire severity and
CBP personnel
from improvement of water
landslides
(see Section 5 for
quality and thus reduction of
¦ Additional long-term beneficial effects
potential
public health and safety impacts
from additional improvement of
mitigation
at the beaches and at Naval
water quality and thus reduction of
measures)
facilities
public health and safety impacts at
¦ Significant, long-
¦ Long-term beneficial effects
the beaches and at Naval facilities
term impact from
from improvement in field
¦ Significant, long-term impact from
exacerbation of
conditions for CBP personnel
increase in unsafe field conditions for
water quality
operating in the Tijuana River,
CBP personnel due to trash boom(s)
issues at public
Goat Canyon, and Smuggler's
(see Section 5 for potential
beaches (see
Gulch
mitigation measures)
Section 5 for
¦ Significant, long-term impact from the
potential
introduction of breeding areas for
mitigation
disease-spreading vectors due to U.S.-
measures)
side river diversion and trash boom(s)
(see Section 5 for potential
mitigation measures)
4.17 Transportation
4.17.1 Standards of Significance
Impacts to transportation would be significant if they were to include any of the following:
• Permanent road closures that prevent access to public or recreational areas or public
services.
• Creation of dangerous or degrading conditions to existing transportation infrastructure or
routes.
• Substantial increases in traffic volumes in residential or congested areas.
4.17.2 No-Action Alternative
The No-Action Alternative would have no impacts to transportation. The ITP would continue to
operate under current conditions, disposing of solids to Punta Bandera in Mexico (see Section 4.13,
Solid and Hazardous Waste). The estimated annual truckloads for ITP solids disposal is 4,724,
which results in approximately 94,480 vehicle miles traveled (VMT) annually.
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4.17.3 Alternative 1: Core Projects
Temporary Effects
Under Alternative 1, implementation of the Core Projects would result in minor, short-term impacts
from increases in vehicle traffic to and from the sites of construction. Construction vehicles would
access the project areas from public roads such as Interstate 5, Monument Road, and Dairy Mart
Road. Construction wastes (e.g., packaging materials and worker refuse) for the Core Projects
(excluding Project C) would be sent to an appropriate regional disposal facility (e.g., Sycamore
Landfill or Otay Landfill), resulting in minor truck traffic impacts. Alternative 1 would not result in
significant impacts to transportation per the criteria in Section 4.17.1 (Standards of Significance).
Alternative 1 would result in no temporary transboundary impacts to transportation.
Construction of Project A (Expanded ITP) would require the import of up to approximately 40,000
cubic yards of fill material to the ITP parcel. To minimize haul route distances, the fill would be
hauled by truck from a suitable source within the Tijuana River Valley such as the Goat Canyon
sediment basins or Smuggler's Gulch, both of which undergo sediment extraction as part of their
regular maintenance. For purposes of conducting truck hauling estimates and estimating VMT, the
fill source location farthest from the ITP parcel was used: the Goat Canyon sediment basins, which
are approximately 3 miles distant It was also assumed that trucks used for the hauling would have
a capacity of 16 cubic yards of material. During construction, it is conservatively estimated that the
hauling of fill material to the ITP parcel would result in up to approximately 15,000 VMT. Figure 4-4
shows the expected truck routes from candidate fill source locations in the Tijuana River Valley to
the ITP parcel.
Construction activities along Monument Road for Project B (Tijuana Canyon Flows to ITP), Option
Bl, would likely result in temporary traffic reconfigurations and/or road closures. Monument Road
is the primary access route to Border Field State Park and is a designated bike route, so traffic
disruptions could affect local recreational users in addition to residents of private property situated
along Monument Road. On-road construction vehicles for Project B would park in staging areas in
Smuggler's Gulch on county-owned land. All other temporary construction vehicle staging areas in
the U.S. would be located on USIBWC-owned land at the ITP parcel or near the corner of Dairy Mart
Road and Clearwater Way.
See Section 4.20 (Environmental Justice) regarding disproportionately high and adverse effects due
to traffic impacts under Alternative 1.
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Pilot channel
Example truck routes from potential fill source locations
Smuggler's Gulch to UP
Goat Canyon to ITP
Smuggler's
Gulch
Goat
Canyon
UNITED]
MEXICO
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
VISTA
Figure 4-4. Truck Routes Between ITP Parcel and Candidate Fill Source Locations
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Permanent Effects
Under Alternative 1, implementation of Projects A (Expanded ITP), B (Tijuana Canyon Flows to
ITP), and D (APTP Phase 1) would result in minor increases in trucking volumes and commuter
traffic volumes in the U.S. Alternative 1 would not result in significant impacts to transportation per
the criteria in Section 4.17.1 (Standards of Significance). Alternative 1 would result in
transboundary transportation impacts due to increased waste hauling requirements in Mexico.
Information regarding truckloads and estimated VMT is summarized in Table 4-34.
The wastewater treatment processes for Projects A and D would produce solids waste that would
require hauling by truck along public transportation routes for disposal at an appropriate regional
disposal facility (see Section 4.13 [Solid and Hazardous Waste]). All solids waste produced for
Projects A would be transported to Punta Bandera in Mexico, where the existing ITP solids waste is
currently disposed.64 All solids waste produced for Project D would be transported to a viable
regional disposal facility in the U.S. Expansion of the ITP from 25 MGD to 40 MGD (Project A, Option
Al) or 50 MGD (Project A, Option A2) would reduce the number of truckloads for solids waste
disposal by approximately 1,168 per year and 192 per year, respectively. Expansion of the ITP to 60
MGD would eventually increase the number of truckloads for solids waste disposal by
approximately 536 per year as the full capacity of the plant comes into service by approximately
2050.65 For Project A, the incorporation of anaerobic digestion into the wastewater processes at the
ITP would significantly reduce the quantity of solids waste produced and thus limit the truckloads
required for disposal. Project D would increase truckloads in the U.S. by approximately 644
truckloads of solid wastes per year.66 Solids waste hauling requirements for the two plants
combined would therefore increase by up to 1,180 truckloads and 48,058 VMT (round trip) per
year compared to current conditions. This represents an increase of no more than approximately
four truckloads per day, even under peak operating conditions in response to wet-weather flows.
The truck hauling route for Project A to Punta Bandera in Mexico would traverse south across the
border through a dedicated gate in the border fence (as is the current practice at the ITP) and
would not pass residential areas in the U.S. or increase traffic in the U.S. The truck route for Project
D would traverse north up Dairy Mart Road and likely onto Interstate 5 towards one of the regional
disposal facilities specified in Section 3.13 (Solid and Hazardous Waste). Approximately two
truckloads per day during peak solids waste production would enter/exit the Interstate 5
interchange, resulting in a negligible increase in AADT counts for the on/off ramps, which currently
have AADTs of 14,100 (on ramp from San Ysidro Blvd.) and 2,500 (off ramp onto Dairy Mart Road)
(see Section 3.17 [Transportation]). Figure 4-5 and Figure 4-6 show the expected truck routes from
the ITP parcel to Punta Bandera and to the candidate regional disposal facilities in the U.S.
64 Or to a beneficial reuse site or new landfill in Mexico, as discussed in Section 4.13 (Solid and Hazardous
Waste).
65 Based on current practices at the ITP, truck trip estimates assume that a single truck to Mexico hauls 25
cubic yards of material.
66 Truck trip estimates for projects that dispose of wastes at regional facilities in the U.S. assume that a single
truck hauls 16 cubic yards of material, which is the size of a typical dump truck.
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Projects A, B, and D would require approximately 82 additional staff for facility O&M, resulting in a
negligible increase in AADT counts on roads in the ITP vicinity. All staff would utilize parking lots
located at the ITP facility, some of which may be expanded to accommodate the staff increases.
Expansion of the ITP would require the permanent relocation of the lower portion of Dairy Mart
Road from its current location to the west perimeter of the ITP parcel. The road at this location is an
internal service road that is not typically traveled by the public, so minimal disruptions to traffic are
expected.
See Section 4.20 (Environmental Justice) regarding disproportionately high and adverse effects due
to traffic impacts under Alternative 1.
Table 4-34. Summary of Estimated Changes in Truckloads and VMT for Solids Waste Disposal
Project
Origin
Destination
Truckloads
VMT
Peak
Daily3
Average
Daily
Annual
Peak
Daily
Average
Daily
Annual
Current conditions (ITP
operations)
ITP
Punta
Bandera
19
13
4,724
388
259
94,500
Project A, Option A1 (Expand
to 40 MGD) onlyc
ITP
Punta
Bandera
-5
-3
-1,168
-96
-64
-23,360
Project A, Option A2 (Expand
to 50 MGD) only b c
-1
-1
-192
-16
-11
-3,840
Project A, Option A3 (Expand
to 60 MGD) only b c d
+2
+1
+536
+44
+29
+10,720
Project D (35 MGD) onlyc
APTP
Sycamore
Landfill6
+2
+2
+644
+112
+102
+37,340
Alternative 1 maximum (Projects A [Option A3] +
D)
+4
+3
+1,180
+156
+132
+48,060
a - A peaking factor of 1.5 was used to calculate the peak daily solids waste production and truckloads, based on
the expected peak daily flow rate and TSS loads in the untreated wastewater and stormwater.
b - Reflects ITP treatment of inflows resulting from Project B (Tijuana Canyon Flows to ITP).
c - Reflects ITP treatment of inflows resulting from Project C (Tijuana Sewer Repairs).
d - Represents eventual operating conditions of 60 MGD (rather than initial operating conditions of 50 MGD),
which is expected to be achieved by 2050 as the population in Tijuana expands.
e -The distance to the farthest regional disposal facility (Sycamore Landfill; see Table 3-12 in Section 3.13) was
used to calculate VMT for this project.
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crnadonaT
^TirEDjSiF'^l)
ir^'rco
Gates
controlled
by CBP
Otay Landfill
Example truck routes to potential landfill locations
— - UP to Punta Bandera via ID
- ITP to Otay Landfill via Dairy Mart Rd
SABTP
mexic
SAN
DIEGO
IMPERIAL
BEACH.
CHULA
WA-
Tijuana
River -
Valley
Figure 4-5. Truck Routes Between ITP Parcel and Candidate Regional Disposal Facilities (1 of 2)
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hm<
nftHA RIVjt
PACIFIC
OCEAN
Sycamore Landfill
Example truck routes to potential landfill location
UP to Sycamore Landfill via 1-5 N and 1-15 N
UP to Sycamore Landfill via 1-805 N and CA-125 N
f^NlTE-PiTSTATES
-1"
Example routes from ITP
[united]
SAN ELCAJ0N
DIEGO
Tijuana River
[MEXICO]
Figure 4-6. Truck Routes Between ITP Parcel and Candidate Regional Disposal Facilities (2 of 2)
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4.17.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Under Alternative 2, implementation of the Core Projects would result in the same minor, short-
term impacts to transportation as would occur under Alternative 1. The general transportation
impacts discussed above for Core Projects (e.g., minor increase in construction vehicle traffic,
transportation impacts to staging areas on USIBWC-owned land) would be applicable to the
Supplemental Projects located in the U.S. Alternative 2 would not result in significant impacts to
transportation per the criteria in Section 4.17.1 (Standards of Significance). Alternative 2 would
result in no temporary transboundary impacts to transportation since vehicles associated with
construction would not cross the border.
See Section 4.20 (Environmental Justice) regarding disproportionately high and adverse effects due
to traffic impacts under Alternative 2.
Permanent Effects
Under Alternative 2, implementation of the Core Projects would result in the same impacts to
transportation as would occur under Alternative 1. Implementation of Project E (APTP Phase 2)
would result in minor increases in commuter traffic volumes beyond those specified for the Core
Projects. As described below, Alternative 2 would result in an additional 1,700 truckloads annually
beyond those specified for the Core Projects (a total of up to 2,880 truckloads annually for Core and
Supplemental Projects), which would translate to an additional 99,000 VMT annually (a total of
147,023 VMT annually for Core and Supplemental Projects combined) for disposing of solids waste
and trash. Alternative 2 would result in one potentially significant impact on transportation per the
criteria in Section 4.17.1 (Standards of Significance). Alternative 2 would result in no recurring
transboundary impacts to transportation since vehicles associated with construction would not
cross the border.
Project E (APTP Phase 2) would increase truckloads by approximately 1,000 per year beyond the
number expected for Project D (APTP Phase 1) and would follow the same truck hauling route as
Project D. This represents a negligible increase in AADT counts for the Interstate 5 on/off ramps at
Dairy Mart Road. During peak solids waste production, however, up to approximately 10 additional
truckloads per day would pass through the interchange, resulting in a minor increase in truck
traffic on those days. Project E would result in approximately 58,000 VMT annually for disposal of
solids waste.
Based on currently available data, Project J (Trash Boom[s]) would result in approximately 700
truckloads annually for disposal of trash extracted from the booms during operations, translating to
up to 41,000 VMT annually (assuming trash would be hauled to a disposal facility in San Diego
County). Depending on the location of the trash processing area(s), these truck trips would
potentially occur near residential areas. However, this estimate is based on very limited data
regarding the expected volume of trash requiring disposal. Additional studies (e.g., a trash boom
pilot study) and stakeholder coordination are needed to determine the anticipated frequency of
extraction and cleaning for the trash boom(s), which would influence the timing and frequency of
truckloads traveling away from the site (e.g., several small hauling events versus one large hauling
event). Depending on these factors, Project J would potentially result in a significant transportation
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impact during hauling activities by causing substantial localized increases in traffic volumes and
congestion near residential areas.
See Section 4.20 (Environmental Justice) regarding disproportionately high and adverse effects due
to traffic impacts under Alternative 2.
4.17.5 Comparative Analysis of the Alternatives
Table 4-35 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
One of the evaluated alternatives would potentially result in significant impacts to transportation
per the criteria in Section 4.17.1 (Standards of Significance). Section 5 (Mitigation Measures and
Performance Monitoring) identifies the mitigation measures that would be implemented for the
Core Projects and provides recommended mitigation measures for the Supplemental Projects
(which would be further refined and developed in subsequent tiered NEPA analyses).
Table 4-35. Comparative Analysis of Effects - Transportation
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Minor, short-term impacts from
increases in vehicle traffic to and
from the sites of construction
¦ Minor, short-term impacts from
temporary traffic reconfigurations
and/or road closures along
Monument Road for Project B
(Tijuana Canyon Flows to ITP),
Option B1
¦ Minor, short-term impacts to traffic
from temporary staging areas in the
U.S. (in Smuggler's Gulch, along
Monument Road, and on USIBWC-
owned land)
Same as Alternative 1
Permanent
effects
¦ Continuation
of current
operations at
the ITP, which
produce an
estimated
4,724 annual
truckloads
(94,480 VMT)
¦ Minor, long-term impact from
increases in commuter traffic
volumes resulting from the
employment of additional staff
needed during operations
¦ Minor, long-term impact from a
total increase of up to 1,180 annual
truckloads (approximately 48,058
VMT)
- Transboundary impact: Minor,
long-term impact from an
estimated increase of up to 536
truckloads annually to Punta
Bandera in Mexico
(approximately 10,720 VMT) or
other new/viable reuse or
disposal facility in Mexico
Same as Alternative 1, plus the
following:
¦ Minor, long-term impact from
additional increase in commuter
traffic volumes associated with
Project E (APTP Phase 2)
¦ Potential significant, long-term impact
from an additional increase of up to
1,700 annual truckloads
(approximately 99,000 VMT),
including:
- Potential significant substantial
localized increases in traffic
volumes and congestion from
Project J, depending on frequency
of trash hauling (see Section 5 for
potential mitigation measures)
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4.18 Noise
4.18.1 Standards of Significance
Noise impacts would be significant if they were to involve any of the following:
• Generation of exterior noise that exceeds standards established by San Diego Municipal
Code §59.5.04.
• Generation of impulsive noise that exceeds standards established by San Diego County Code
§36.410.
• Exposure of buildings, including fragile buildings and buildings that require low ambient
vibration for interior operations (e.g., research facilities), to excessive or substantial
ground-borne vibration.
• A substantial increase in ambient noise levels perceived at noise-sensitive receptors.
Noise standards are described in more detail in Section 6.1.13 (Noise).
4.18.2 No-Action Alternative
The No-Action Alternative would result in no change in existing noise and ground-borne vibration
impacts. Continued operation of the ITP at its existing capacity would continue to generate minor
ambient noise and ground-borne vibration from equipment and waste hauling.
4.18.3 Alternative 1: Core Projects
Temporary Effects
Under Alternative 1, certain construction activities for implementation of the Core Projects would
be reasonably likely to temporarily expose noise-sensitive receptors to noise levels, including
impulsive noise levels, above city and county limits if no mitigation were implemented. In addition,
ground-borne vibration from certain construction activities could result in minor annoyances,
based on an evaluation using methodology from the Transit Noise and Vibration Impact Assessment
Manual and comparison with construction vibration damage criteria (FTA, 2018).
Noise levels would vary depending on the type of construction equipment used. Common examples
of equipment that could be used during construction of Core Projects and their associated noise
levels include air compressors, backhoes, and loaders (approximately 80 dBA); compactors and
generators (approximately 82 dBA); trucks (approximately 84 dBA); rollers, pavers, and dozers
(approximately 85 dBA); and jack hammers (approximately 88 dBA) (FTA, 2018).67 Noise from
construction activities and vehicle traffic would attenuate at an approximate rate of 3 to 6 dBA per
doubling of distance over open terrain. Noise would drop off over a shorter distance if obstructions
were present that would block the path of propagation, which would decrease noise perceived at
sensitive receptors the farther they are located from the noise source (Caltrans, 2013). For most
67 The typical noise levels provided by the Federal Transit Administration (FTA) (2018) use a measurement
distance of 50 feet from the respective construction equipment noise source.
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work associated with Core Projects, besides work in Smuggler's Gulch and along Monument Road,
construction noise would be expected to attenuate below applicable noise limits before reaching
noise-sensitive receptors in the U.S. and would not constitute a substantial increase in ambient
noise levels.
Specifically, construction activities for Project A (Expanded ITP) would likely result in moderate
temporary noise impacts to sensitive receptors if no mitigation were implemented. Receptors
affected due to construction activities at the ITP parcel could include protected species habitat
(depending on construction timing), a small portion of Tijuana River Valley Regional Park, and
residences in Tijuana immediately across the U.S.-Mexico border from the site of the proposed ITP
facilities (e.g., the anaerobic digester building). Construction would take place over a period of at
least two years. At a distance of 350 feet, which is the approximate closest distance of residences (in
Tijuana) to potential construction activity, the vibration levels of heavy construction equipment at
the ITP could result in minor annoyances.
Construction activities for ProjectB (Tijuana Canyon Flows to ITP), Option B1 (Trenching via
Smuggler's Gulch and Monument Rd), would potentially result in substantial temporary and
localized noise impacts to protected species habitat (depending on construction timing),
recreational areas (e.g., trails in Smuggler's Gulch), and residences immediately adjacent to portions
of Monument Road (including one residence approximately 20 feet from the road). Additionally,
Smuggler's Gulch has a U-shaped topography that is open to the north with a large earthwork along
the border enclosing the southern end; therefore, noise from construction activities within the
gulch would potentially be reflected and focused to the north towards residences in the U.S., while
the earthwork would likely decrease noise propagation to the south towards residences in Tijuana.
However, construction for Project B would be very short-term and would likely occur only during
the day. As discussed in Sections 4.4 (Inland Biological Resources) and 5 (Mitigation Measures and
Performance Monitoring), to the greatest extent practicable, construction activities within 300 feet
of suitable least Bell's vireo habitat and coastal California gnatcatcher habitat would be avoided
during the vireo breeding season (March 15 to August 31) and the gnatcatcher breeding season
(February 15 to August 31), respectively. If work were necessary during these breeding seasons,
preconstruction surveys for least Bell's vireo and coastal California gnatcatchers would be
conducted, and no-disturbance buffers would be implemented to reduce potential noise- and
vibration-related disturbances.
Open-cut trenching, directional drilling, and pavement removal and replacement associated with
Project B would generally not require the use of heavy vibration-producing equipment Option B1
would have greater potential for vibration impacts to residences located in close proximity along
Monument Road. However, vibration-generating work in these areas would likely be limited to
small, handheld equipment such as jackhammers and compactors. At a distance of 20 feet, which is
the approximate closest distance of residences to potential construction activity, the vibration
levels of jackhammers could result in minor annoyances. Construction noise and vibration for
Options B2 (Trenchless via Smuggler's Gulch and Under Mesa) and B3 (Connect to Existing Canyon
Collector System) would be limited to areas surrounding micro-tunneling entry and exit points and
would not constitute a substantial increase in ambient noise levels.
Certain construction activities for Project C (Tijuana Sewer Repairs) would occur directly south of
the U.S.-Mexico border and would potentially result in minor localized transboundary noise impacts
to protected species habitat (depending on construction timing) and recreational areas (e.g., trails
in Smuggler's Gulch) in the U.S. However, construction-related noise and vibration would be short-
term and much less extensive than required for other Core Projects; would not be perceptible at
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U.S. residential areas due to the distance to the U.S.-Mexico border; and would not be expected to
constitute a substantial increase in ambient noise levels in the U.S.
Project D (APTP Phase 1) would require construction activities similar to those under Project A;
however, construction of the new APTP would be much less extensive and would be performed
over a shorter duration. Thus, noise impacts associated with Project D construction would be more
temporary and minor in comparison to Project A. Construction noise and vibration from installation
of the new force main, including transboundary effects to and from Mexico, would be limited to
areas surrounding the micro-tunneling entry and exit points.
Construction vehicles traveling along Monument Road and through the Interstate 5 interchange for
Core Projects would not be expected to generate a substantial increase in ambient noise levels.
However, vibration associated with loaded trucks at a distance of 20 feet could result in minor
annoyances.
See Section 4.4 (Inland Biological Resources) for discussion of the potential for construction noise
to affect protected species.
Construction workers would also be exposed to high noise levels typically associated with
construction activities and would be required to adhere to applicable safety measures (e.g., hearing
protection).
Permanent Effects
Under Alternative 1, implementation of the Core Projects would likely result in changes in noise
frequency and ground-borne vibration perceived at noise-sensitive receptors along waste hauling
routes due to potential changes in heavy vehicle traffic associated with solids waste disposal during
operation of Projects A (Expanded ITP) and D (APTP Phase 1). Specifically, Option A1 (Expand to 40
MGD) would decrease waste disposal requirements for the ITP and therefore reduce the frequency
of noise and vibration-related annoyances generated from heavy vehicle traffic along Monument
Road. Increased waste hauling under Options A2 (Expand to 50 MGD) and A3 (Expand to 60 MGD)
and Project D would potentially result in a slight increase in these noise and vibration impacts.
Noise generation from waste hauling would likely be below city and county limits at noise-sensitive
receptors and would not constitute a substantial increase in ambient noise levels. See Section 4.17
(Transportation) for a more detailed discussion of transportation impacts.
Noise-producing equipment, such as emergency generators, installed for Projects A and D would
result in minor noise generation that would likely attenuate below perceptible levels before
escaping USIBWC property boundaries. Emergency generators would operate only during testing
and unplanned electrical outages. In addition, new facilities would be designed consistent with
standard building design codes and applicable noise codes and ordinances such that equipment
would not create substantial noise that would escape the property boundaries. However, as
discussed in Section 4.14 (Energy), Project A would potentially include continuous (or near-
continuous) operation of a reciprocating engine to combust waste biogas from the anaerobic
digester facility and generate electricity for use at the expanded ITP. Depending on the engine's
capacity and its location within the ITP parcel, its operation would have the potential to exceed
exterior noise standards (particularly during nighttime operation, when noise standards are lower)
or result in increased ambient noise levels at noise-sensitive receptors. This impact would be
mitigated through proper siting of the engine within the ITP parcel (e.g., away from the property
boundaries) and incorporation of noise attenuation features.
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No other components of Core Projects would be expected to increase ambient noise levels at noise-
sensitive receptors, generate exterior or impulsive noise above city or county limits, or result in
permanent or recurring noise or ground-borne vibration impacts.
4.18.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Construction activities for Alternative 2 would result in temporary effects similar to those under
Alternative 1; however, implementation of Supplemental Projects under Alternative 2 would
include the construction of additional infrastructure and would therefore potentially increase the
duration of construction-related noise and ground-borne vibration annoyances. For Core Projects,
temporary effects would be the same as those under Alternative 1. Certain construction activities
for Supplemental Projects would be reasonably likely to temporarily expose noise-sensitive
receptors to noise levels, including impulsive noise levels, above city and county limits during
construction if no mitigation were implemented. In addition, ground-borne vibration from certain
construction activities could result in minor annoyances.
Construction activities for Project E (APTP Phase 2) would likely result in minor, short-term,
localized noise impacts to protected species habitat (depending on construction timing).
Construction activities for Projects F (U.S.-side River Diversion to APTP) and J (Trash Boom[s])
would potentially result in minor construction noise impacts and vibration-related annoyances.
These impacts could affect protected species habitat (depending on construction timing),
residences in the U.S. immediately east and/or north from the potential U.S.-side river diversion
and trash boom(s), and residences in Tijuana immediately across the U.S.-Mexico border from the
potential U.S.-side river diversion and trash boom(s). Noise and vibration impacts and the need for
mitigation would be dependent on the location of the proposed river diversion and trash boom(s),
which would be further defined and analyzed in subsequent tiered NEPA analyses.
Construction activities for Project I (ITP Treated Effluent Reuse) would potentially result in minor,
short-term noise impacts and vibration-related annoyance to protected species habitat (depending
on construction timing) and residences in Tijuana immediately across the U.S.-Mexico border from
the site of the proposed treated effluent reuse pipeline. Construction activities in Mexico near the
border would potentially generate transboundary noise, but the noise impacts would be short-term
and minor; would not be expected to affect noise-sensitive receptors in the U.S. due to the distance
between these receptors and the U.S.-Mexico border; and would not constitute a substantial
increase in ambient noise levels.
Construction activities for Projects G (New SABTP) and H (Tijuana WWTP Treated Effluent Reuse)
would not be expected to have transboundary noise or ground-borne vibration impacts to the U.S.
due to their distance from the U.S.
Construction vehicles traveling along Monument Road and through the Interstate 5 interchange for
Supplemental Projects would not be expected to result in noise impacts to noise-sensitive receptors
and would not constitute a substantial increase in ambient noise levels, but could result in minor
vibration-related annoyances.
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See Section 4.4 (Inland Biological Resources) for discussion of the potential for construction noise
to affect protected species.
Construction workers would also be exposed to high noise levels typically associated with
construction activities and would be required to adhere to applicable safety measures (e.g., hearing
protection).
Permanent Effects
Under Alternative 2, implementation of the Core Projects would result in the same permanent
effects as would occur under Alternative 1. Certain Supplemental Projects in Alternative 2 would
result in minor additional permanent noise impacts to noise-sensitive receptors and vibration-
related annoyances, but these impacts would not constitute a substantial increase in ambient noise
levels. Specifically, Projects E (APTP Phase 2) and J (Trash Boom[s]) would increase waste disposal
requirements for the APTP and trash boom(s) and therefore would potentially result in a slight
increase in the frequency of noise and minor vibration-related annoyances generated from heavy
vehicle traffic along Monument Road. Noise generation from waste hauling would likely be below
city and county limits at noise-sensitive receptors and would not constitute a substantial increase
in ambient noise levels. See Section 4.17 (Transportation) for a more detailed discussion of
transportation impacts.
Maintenance activities for Project J would require the occasional use of heavy equipment, such as a
bulldozer or front-end loader, for trash extraction. Trash extraction would potentially result in
minor, localized noise impacts and vibration-related annoyances. Therefore, maintenance for
Project J could affect protected species habitat (depending on maintenance timing), residences in
the U.S. immediately east and/or north from the potential trash boom(s), and residences in Tijuana
immediately across the U.S.-Mexico border from the potential trash boom(s) if no mitigation were
implemented. Noise and vibration impacts and the need for mitigation would be dependent on the
location of the proposed trash boom(s), which would be further defined and analyzed in
subsequent tiered NEPA analyses.
Project F (U.S.-side River Diversion to APTP) would potentially result in a minor increase in
operational noise from pumps that would be perceptible at noise-sensitive receptors if no
mitigation were implemented. These impacts and the need for mitigation would be dependent on
the location of the diversion, which would be further defined and analyzed in subsequent tiered
NEPA analyses. Noise-producing equipment, such as generators, installed for Projects E and I (ITP
Treated Effluent Reuse) would result in minor noise generation that would likely attenuate below
perceptible levels before escaping USIBWC property boundaries. In addition, new facilities would
be designed consistent with standard building design codes and applicable noise codes and
ordinances such that equipment would not create substantial noise that would escape the property
boundaries.
No other components of Alternative 2 would be expected to increase ambient noise levels at noise-
sensitive receptors, generate exterior or impulsive noise above city or county limits, or result in
permanent noise or ground-borne vibration impacts.
4.18.5 Comparative Analysis of the Alternatives
Table 4-36 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
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Two of the evaluated alternatives would, in the absence of mitigation, potentially result in
significant impacts to noise per the criteria in Section 4.18.1 (Standards of Significance). Section 5
(Mitigation Measures and Performance Monitoring) identifies the mitigation measures that would
be implemented for the Core Projects and provides recommended mitigation measures for the
Supplemental Projects (which would be further refined and developed in subsequent tiered NEPA
analyses).
Table 4-36. Comparative Analysis of Effects - Noise
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Potential significant, short-term impacts
from localized, short-term exceedances of
city and county noise levels (see Section 5
for potential mitigation measures)
¦ Potential significant, short-term impacts
from substantial increases in noise levels in
specific areas near noise-sensitive receptors
(e.g., protected species habitat and
recreational areas in Smuggler's Gulch;
residences immediately adjacent to portions
of Monument Road) (see Section 5 for
potential mitigation measures)
¦ Minor to moderate, short-term impacts
from increases in noise levels perceived at
recreational areas and residences in the U.S.
and Tijuana
¦ Potential minor, short-term impacts to
residential buildings from exposure to
ground-borne vibration annoyances
¦ Minor, short-term impacts to construction
workers from typical occupational noise
exposure
Same as Alternative 1, plus the
following:
¦ Potential minor, short-term
impacts from increase in
duration of construction-related
noise and ground-borne
vibration annoyances due to
construction of additional
infrastructure
Permanent
effects
¦ None
¦ Potential significant, long-term impacts from
increase in noise due to continuous (or near-
continuous) operation of biogas-fired engine
and electrical generator (see Section 5 for
potential mitigation measures)
¦ Minor, long-term impacts from increase in
noise and ground-borne vibration impacts
perceived at protected species habitat
(depending on construction timing),
recreational areas, and residences in the
U.S. and Tijuana due to increases in heavy
vehicle traffic; however, this would not
constitute a substantial increase in ambient
noise levels
Same as Alternative 1, plus the
following:
¦ Potential minor, long-term
impacts from increase in
operational noise from new
equipment under Projects F and
J that would potentially be
perceptible at noise-sensitive
receptors if no mitigation were
implemented
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4.19 Socioeconomics
4.19.1 Standards of Significance
Impacts to social and economic resources would be significant if they were to result in any of the
following:
• Substantial increase in poverty or unemployment levels.
• Substantial reduction in housing availability, housing affordability, or property values.
• Substantial reduction in access, availability, or affordability of public services and utilities.
• Increase in job growth, population growth, or population concentration to an extent that
requires substantial increases in housing, public services, public utilities, or the costs for
local governments to provide these services.
4.19.2 No-Action Alternative
Under the No-Action Alternative, coastal communities in San Diego County, including the City of
Imperial Beach, and communities near the Tijuana River would continue to experience adverse
socioeconomic impacts due to water quality-related beach closures and poor water quality in the
river. The No-Action Alternative would not result in any changes in population, housing,
employment, economic activity, or other socioeconomic factors.
4.19.3 Alternative 1: Core Projects
Temporary Effects
Construction for Core Projects implemented under Alternative 1 would potentially result in
benefits to social and economic resources through minor short-term increases in employment and
economic activity during construction (e.g., meals and incidentals for construction workers).
Construction activities would also potentially result in minor short-term increases in population
and demand for rental housing for non-local workforce; but it is not known from which locations in
the region the construction workforce would travel to be employed on the project. Based on a
review of EJScreen and the California Healthy Places Index, residential housing within the census
tract containing the ITP has a high percentage of rental properties, relative to the county as a whole
(Public Health Alliance, 2022). While this suggests that rental properties may be available to
regional workforce interested in living immediately adjacent to the construction site, housing in
this tract—and in several other tracts surrounding the ITP parcel—is typically completely occupied
or overcrowded (e.g., 500 of 522 units are occupied in the block group downstream of Dairy Mart
Road Bridge). This could influence the non-local construction workforce to look elsewhere in the
San Diego region for short-term housing. Available unoccupied housing units are assumed to exist
within reasonable commuting distance elsewhere in the San Diego region. The Core Projects
therefore would not be expected to substantially reduce housing availability, affordability, or
property values immediately adjacent to the construction sites (at the ITP parcel and in Smuggler's
Gulch). Short-term job and population growth would not strain existing housing or public services
and utilities to an extent that would increase costs to local governments. Construction for
Alternative 1 would not result in significant impacts to socioeconomics per the criteria in Section
4.19.1 (Standards of Significance).
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Permanent Effects
Under Alternative 1, implementation of the Core Projects would create minor new employment
opportunities—specifically, the hiring of up to approximately 82 new O&M staff—and would create
potential indirect socioeconomic benefits due to improved water quality in downstream portions of
the Tijuana River Valley and adjacent coastal areas. These potential benefits could include
improved recreational conditions, reduced risks to human health, and reduction of water quality-
related barriers to tourism and related economic activity in coastal communities (e.g., City of
Imperial Beach). It is unknown how many of the new O&M staff would relocate to southern San
Diego County and would thus require housing. To the extent that new staff do require housing,
available unoccupied housing units are assumed to exist within reasonable commuting distance
elsewhere in the San Diego region despite the limited housing availability in the immediate vicinity
of the ITP parcel. Implementation of the Core Projects therefore would not be expected to
substantially reduce housing availability, affordability, or property values. See Sections 4.1
(Freshwater and Estuarine Resources), 4.2 (Marine Waters), and 4.16 (Public Health and Safety) for
additional discussions.
The anaerobic digestion process that would be used for Project A (Expanded ITP) would produce
solids with a higher organic content. These solids could be suitable for beneficial reuse, such as land
application, which could enhance agricultural production. Pathogen reduction and vector attraction
reduction would need to be ensured so that land application of biosolids does not threaten human
health and the environment.
These socioeconomic benefits from implementation of the Core Projects would not be expected to
affect long-term population trends or demand for public services and utilities. Alternative 1 would
not result in significant impacts to socioeconomics per the criteria in Section 4.19.1 (Standards of
Significance).
4.19.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Under Alternative 2, implementation of the Core Projects would result in the same impacts to
socioeconomics as would occur under Alternative 1. However, Alternative 2 would require a
greater amount of construction for implementation of Supplemental Projects, resulting in minor
increases in employment and economic activity (e.g., meals and incidentals for construction
workers). Similar to Alternative 1, construction activities would also potentially result in minor
short-term increases in population and demand for rental housing for non-local workforce; but it is
not known from which locations in the region the construction workforce would travel to be
employed on the project For the same reasons as stated under Alternative 1, the Supplemental
Projects therefore would not be expected to substantially reduce housing availability, affordability,
or property values immediately adjacent to the construction sites (at the ITP parcel and in
Smuggler's Gulch). Short-term job and population growth would not strain existing housing or
public services and utilities to an extent that would increase costs to local governments.
Construction for Alternative 2 would not result in significant impacts to socioeconomics per the
criteria in Section 4.19.1 (Standards of Significance).
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Permanent Effects
Under Alternative 2, implementation of the Core Projects would result in the same impacts to
socioeconomics as would occur under Alternative 1. Alternative 2 would result in slightly more
employment opportunities than Alternative 1—specifically, the hiring of up to approximately 27
additional O&M staff for Supplemental Projects—and would create additional potential indirect
socioeconomic benefits due to greater improvements to water quality in downstream portions of
the Tijuana River Valley and adjacent coastal areas. These potential benefits could include
improved recreational conditions, reduced risks to human health, and reduction of water quality-
related barriers to tourism and related economic activity in coastal communities (e.g., City of
Imperial Beach). Similar to Alternative 1, available unoccupied housing units would be assumed to
exist within reasonable commuting distance elsewhere in the San Diego region despite the limited
housing availability in the immediate vicinity of the ITP parcel. Implementation of the Supplemental
Projects therefore would not be expected to substantially reduce housing availability, affordability,
or property values. The total social and economic impacts for Supplemental Projects are
indeterminable at this time and would be analyzed in subsequent tiered NEPA analyses.
Implementation of Project J (Trash Boom[s]) would substantially reduce floatable transboundary
trash in the Tijuana River Valley and Estuary, which would improve access to recreational
resources, improve the visual quality of downstream areas, and reduce public health risks and
odors.
Implementation of Projects H (Tijuana WWTP Treated Effluent Reuse) and I (ITP Treated Effluent
Reuse) would potentially have beneficial socioeconomic impacts in Tijuana by helping to satisfy the
increasing water demand.
The socioeconomic benefits from implementation of Alternative 2 would not be expected to affect
long-term population trends or demand for public services and utilities.
See Sections 4.1 (Freshwater and Estuarine Resources), 4.2 (Marine Waters), 4.8 (Visual
Resources), 4.11 (Air Quality and Odor), 4.16 (Public Health and Safety), and 4.17 (Transportation)
for additional discussions.
4.19.5 Comparative Analysis of the Alternatives
Table 4-37 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
None of the evaluated alternatives would result in significant impacts to socioeconomic resources
per the criteria in Section 4.19.1 (Standards of Significance).
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Table 4-37. Comparative Analysis of Effects - Socioeconomics
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Minor increase in employment due
to hiring of construction workers
¦ Minor increase in economic activity
during construction (e.g., meals and
incidentals for construction
workers)
¦ No reduction in access to housing or
public services and utilities
Same as Alternative 1, plus the
following:
¦ Additional minor increases in
employment and economic
activities due to construction of
additional infrastructure
Permanent
effects
¦ None
¦ No reduction in
adverse
socioeconomic
impacts due to
water-quality
related beach
closures and
public health
concerns
¦ Increase in employment from the
hiring of up to 82 new O&M staff
¦ Improved recreational conditions,
reduced risks to human health, and
reduction of water quality-related
barriers to tourism and related
economic activity in coastal
communities
¦ Potential increases in agricultural
productivity through beneficial
reuse of solids for land application
¦ No reduction in access to housing or
public services and utilities
Same as Alternative 1, plus the
following:
¦ Additional increases in employment
from the hiring of up to 27 new
O&M staff
¦ Additional socioeconomic benefits
associated with water quality
improvements
¦ Potential alleviation of water
demand by providing treated
effluent reuse
4.20 Environmental Justice
4.20.1 Standards of Significance
Per CEQ guidance regarding environmental justice (1997b), significance of impacts of the Proposed
Action—including consideration of context (e.g., an incremental increase in impacts to a highly
overburdened community) and intensity as defined by NEPA—is a factor for determining whether
the impacts are disproportionately high and adverse. EPA and USIBWC, in accordance with CEQ and
EPA environmental justice guidance, analyzed whether impacts would be disproportionately high
and adverse, recognizing that impacts may be both disproportionately high and adverse and
significant per NEPA depending on the context and intensity most relevant to the communities with
environmental justice concerns that are affected (those identified in Section 3.20 [Environmental
Justice]).
As described in Section 3.20 (Environmental Justice), EPA and USIBWC evaluated whether
environmental inequities exist in communities in the EJ Study Area, which includes communities in
the vicinity of construction and operational activities under the Proposed Action. This analysis
determined that minority and, to a lesser extent, low-income populations are prevalent throughout
the EJ Study Area, including several communities in the immediate vicinity of the ITP with
extremely high (90th percentile and higher) minority and low-income population percentiles
relative to the County of San Diego overall. Additionally, many communities in the EJ Study Area
currently experience extremely high (90th percentile and higher) burdens for multiple
environmental indicators, including poor air quality (e.g., PM2.5 and diesel PM) and traffic-related
impacts, among others. The multiple social and environmental burdens in these communities
contribute stressors that can amplify impacts of the Proposed Action and further increase
overburdens felt by the community. See Section 3.20 (Environmental Justice) and Appendix I
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(Supplemental Data for Environmental Justice Analysis) for additional information. EPA and
USIBWC considered this context in determining whether specific impacts under the Proposed
Action should be considered significant (within the meaning of NEPA) and/or disproportionately
high and adverse.
4.20.2 No-Action Alternative
Under the No-Action Alternative, the existing ITP would continue to exist with no changes in
operation, meaning contaminated transboundary flows would continue to result in impacts to the
surrounding community that currently experiences high social and environmental burdens. The
No-Action Alternative would not achieve the desired environmental improvements to the
surrounding community because this alternative does not reduce contaminated transboundary
flows in the Tijuana River, estuary, and coastal areas.
4.20.3 Alternative 1: Core Projects
Temporary Effects
Construction for Core Projects implemented under Alternative 1 would result in temporary impacts
to communities with environmental justice concerns due to construction-related emissions and
traffic. As described below, construction for Alternative 1 would result in disproportionately high
and adverse effects on minority, low-income, and/or overburdened communities. EPA and USIBWC
would incorporate mitigation measures as described in Section 5 (Mitigation Measures and
Performance Monitoring) to avoid, minimize, or compensate for these effects.
Construction for Projects A (Expanded ITP) and D (APTP Phase 1) would result in extended periods
of construction activity at the ITP parcel, including use of heavy trucks along roads between the ITP
parcel, fill source locations in the Tijuana River Valley, and landfills (e.g., Otay Landfill) for disposal
of construction debris. These construction activities would therefore result in temporary increases
in criteria air pollutant emissions (including PM2.5 and diesel PM) and traffic. As discussed in
Sections 4.11 (Air Quality and Odor) and 4.17 (Transportation), all criteria pollutant emissions
from construction (including PM) would be very low compared to both GCR de minimis thresholds
and San Diego AQIA trigger levels, and the expected increase in counts of vehicles during
construction would be very low compared to existing average daily traffic volumes. However, these
impacts would occur in communities that currently experience high (between the 65-89th
percentiles) and/or extremely high (90th percentile or higher) burdens for these specific
environmental indicators in addition to other social and environmental burdens—e.g., 95th
percentile or higher for PM2.5 in all portions of the EJ Study Area and 65th percentile or higher for
Diesel PM in more than half of the census tracts in the EJ Study Area (CalEPA, 2021a). Therefore,
these construction-related impacts under Projects A and D would be significant when considered
within the context of the impacted communities. Additionally, because these impacts would occur
predominantly within minority, low-income, and/or overburdened communities, impacts to these
communities would appreciably exceed those to the general population (e.g., San Diego County as a
whole). EPA and USIBWC therefore considered these air quality and traffic-related impacts under
Projects A and D to be disproportionately high and adverse effects.
Construction for Project B (Tijuana Canyon Flows to ITP), depending on the option selected, would
also result in temporary construction activity in the U.S. between Smuggler's Gulch and the ITP
parcel to install underground pipelines. While these activities would generate temporary air
emissions and vehicle use, work would involve small construction crews and equipment fleets and
would not involve prolonged use of heavy trucks along local roads and highways. Construction-
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related impacts under Project B would therefore not be significant when considered within the
context of the impacted communities and would not be disproportionately high and adverse.
Construction and sewage collector repair activities in Mexico under Projects B, C (Tijuana Sewer
Repairs), and D would not result in temporary transboundary impacts to air quality in the U.S. due
to their distance from the U.S.-Mexico border and/or limited scope of construction activities, and
would not result in any temporary traffic impacts in the U.S. These activities would therefore not be
significant when considered within the context of the impacted communities and would not be
disproportionately high and adverse.
Due to the proximity to the U.S.-Mexico border and communities in Tijuana, construction activities
at the ITP parcel—particularly under Project A—would potentially result in temporary minor to
moderate transboundary air quality and noise effects on receptors in Mexico. These temporary
impacts could contribute to existing socio-environmental vulnerabilities in Mexico communities
along the border.
See Sections 4.11 (Air Quality and Odor), 4.17 (Transportation), 4.18 (Noise), and 4.19
(Socioeconomics) for additional discussion of temporary construction-related impacts. See Section
4.21.5 (Cumulative Effects) regarding significant cumulative environmental justice impacts that
require mitigation, based on a review of the impacts of other past, present, or reasonably
foreseeable actions.
Permanent Effects
Under Alternative 1, implementation of the Core Projects would result in long-term impacts to
communities with environmental justice concerns due to operational emissions, odor, and traffic.
As described below, Alternative 1 would result in disproportionately high and adverse effects on
minority, low-income, and/or overburdened communities. EPA and USIBWC would incorporate
mitigation measures as described in Section 5 (Mitigation Measures and Performance Monitoring)
to avoid, minimize, or compensate for these effects.
Operations under Projects A (Expanded ITP) and D (APTP Phase 1) would result in long-term
operational emissions, a long-term increase in employee commuting to the ITP parcel due to staff
increases, and a long-term increase in the use of heavy trucks along roads between the ITP parcel
and landfills (e.g., Otay Landfill) for disposal of solids waste. These operations would therefore
result in long-term increases in criteria air pollutant emissions (including PM2.5 and diesel PM) and
traffic. As discussed in Sections 4.11 (Air Quality and Odor) and 4.17 (Transportation), all criteria
pollutant emissions from operations (including PM) would be very low compared to both GCR de
minimis thresholds and San Diego AQIA trigger levels, with the incorporation of pollution controls
as described in Section 4.11 (Air Quality and Odor), and the expected increase in counts of vehicles
during operation would be very low compared to existing average daily traffic volumes. However,
these impacts would occur in communities that currently experience extremely high burdens for
these specific environmental indicators in addition to other social and environmental burdens.
Therefore, these operational impacts under Projects A and D would be significant when considered
within the context of the impacted communities. Additionally, as described in Section 4.11 (Air
Quality and Odor), H2S emissions from the anaerobic digestion process under Project A—which
would operate on a continuous (or near-continuous) basis—would have the potential to create
objectionable odors affecting nearby communities, thus resulting in a significant impact. Because
these impacts would occur predominantly within minority, low-income, and/or overburdened
communities, impacts to these communities would appreciably exceed those to the general
population (e.g., San Diego County as a whole). EPA and USIBWC therefore considered these air
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quality, odor, and traffic-related impacts under Projects A and D to be disproportionately high and
adverse effects.
Projects B (Tijuana Canyon Flows to ITP) and C (Tijuana Sewer Repairs) would not generate
operating emissions and would involve minimal or no traffic impacts associated with O&M.
Operational impacts from these projects would therefore not be significant when considered within
the context of the impacted communities and would not be disproportionately high and adverse.
Due to the proximity to the U.S.-Mexico border and communities in Tijuana, the operational
activities described above at the ITP parcel—particularly under Project A—would potentially result
in long-term minor to moderate transboundary air quality, odor, and noise impacts to receptors in
Mexico. Additionally, under Project A, increased truck hauling of solid waste to a disposal site68 in
Mexico (through a dedicated ITP gate in the border fence) would increase the associated air quality,
noise, and traffic impacts in Mexico.69 These long-term impacts could contribute to existing socio-
environmental vulnerabilities in Mexico communities along the border. EPA and USIBWC are
available to support the Mexican government in conducting targeted community outreach and
engagement, should the Mexican government request support
See Sections 4.11 (Air Quality and Odor), 4.13 (Solid and Hazardous Waste), 4.17 (Transportation),
and 4.19 (Socioeconomics) for additional discussion. See Section 4.21.5 (Cumulative Effects)
regarding significant cumulative environmental justice impacts that require mitigation, based on a
review of the impacts of other past, present, or reasonably foreseeable actions.
4.20.4 Alternative 2: Core and Supplemental Projects
Supplemental Projects are included in this PEIS at a programmatic level and are intended to be
analyzed further in subsequent tiered NEPA analyses.
Temporary Effects
Under Alternative 2, implementation of the Core Projects would result in the same impacts to
communities with environmental justice concerns as would occur under Alternative 1. However,
Alternative 2 would require a greater amount of construction for implementation of Supplemental
Projects, resulting in slight increases in temporary impacts to communities with environmental
justice concerns that would be further analyzed in subsequent tiered NEPA analyses. Construction
for Alternative 2 would result in disproportionately high and adverse effects on minority, low-
income, and/or overburdened communities. EPA and USIBWC would perform additional public
outreach as necessary during the subsequent tiered NEPA analyses to explore and incorporate
appropriate mitigation measures to avoid, minimize, or compensate for these effects.
68 As discussed in Section 3.13 (Solid and Hazardous Waste), disposal site alternatives to Punta Bandera have
not been identified by Mexico yet. EPA may coordinate with Mexico to ensure mitigation measures are
identified once Mexico selects an alternative disposal site.
69 Options A1 and A2 would decrease solids waste production. For Option A3, initial operating conditions
would also result in a decrease in solids waste production; however, between approximately 2030 and 2050,
plant operations would gradually increase solids waste production as the additional treatment capacity
comes into service in response to population growth.
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Construction for certain Supplemental Projects would result in extended periods of construction
activity in the vicinity of the ITP parcel, including use of heavy trucks along roads between the ITP
parcel and landfills (e.g., Otay Landfill) for disposal of construction debris. Specifically, construction
for Projects E (APTP Phase 2), F (U.S.-side River Diversion to APTP), and J (Trash Boom[s]) would
result in temporary increases in criteria air pollutant emissions (including PM2.5 and diesel PM) and
traffic. As discussed in Sections 4.11 (Air Quality and Odor) and 4.17 (Transportation), criteria
pollutant emissions from construction for the Supplemental Projects (including PM) are estimated
to be similar to or less than those for the Core Projects, which are well below both GCR de minimis
thresholds and San Diego AQIA trigger levels, and the expected increase in counts of vehicles during
construction would be very low compared to existing average daily traffic volumes. However, these
impacts would occur in communities that currently experience extremely high burdens for these
specific environmental indicators in addition to other social and environmental burdens.
Additionally, some areas under consideration for the U.S.-side river diversion and trash boom(s)
are located in very close proximity (approximately 230 feet) to residential developments, such as
those in the Coral Gate neighborhood. Therefore, these construction-related impacts under Projects
E, F, and J would be potentially significant when considered within the context of the impacted
communities. Additionally, because these impacts would occur predominantly within minority,
low-income, and/or overburdened communities, impacts to these communities would appreciably
exceed those to the general population (e.g., San Diego County as a whole). EPA and USIBWC
therefore considered these air quality and traffic-related impacts under Projects E, F, and J to be
potentially disproportionately high and adverse effects.
Construction for Project I (ITP Treated Effluent Reuse) would involve temporary, limited activity in
the ITP parcel along a narrow linear footprint for installation of a treated effluent pipeline. While
this activity would generate temporary air emissions and result in vehicle use, work would be
limited to a small construction footprint and would not involve prolonged use of heavy vehicles.
Construction-related impacts under Project I would therefore not be significant when considered
within the context of the impacted communities and would not be disproportionately high and
adverse.
Construction activities in Mexico under Project I would result in temporary transboundary impacts
to air quality in the U.S. due to the distance from the U.S.-Mexico border. However, due to the
limited scope of construction activities (i.e., less than 300 feet of pipeline installation to cross the
border), these impacts would not be significant when considered within the context of the impacted
communities and would not be disproportionately high and adverse. Construction for Projects G
(New SABTP) and H (Tijuana WWTP Treated Effluent Reuse) in Mexico would not result in any
temporary impacts to minority, low-income, and/or overburdened communities in the U.S. because
these projects are substantially removed in distance from U.S. communities.
Due to the proximity to the U.S.-Mexico border and communities in Tijuana, construction activities
at the ITP parcel for Projects E and I would potentially result in temporary minor transboundary air
quality effects on receptors in Mexico. In addition, Projects E, F, I, and J would potentially result in
temporary minor transboundary noise effects on receptors in Mexico. These temporary impacts
could contribute to existing socio-environmental vulnerabilities in Mexico communities along the
border.
See Sections 4.11 (Air Quality and Odor), 4.17 (Transportation), 4.18 (Noise), and 4.19
(Socioeconomics) for additional discussion of temporary construction-related impacts. See Section
4.21.5 (Cumulative Effects) regarding significant cumulative environmental justice impacts that
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require mitigation, based on a review of the impacts of other past, present, or reasonably
foreseeable actions.
Permanent Effects
Under Alternative 2, implementation of the Core Projects would result in the same impacts to
communities with environmental justice concerns as would occur under Alternative 1. Alternative 2
would potentially result in disproportionately high and adverse effects on minority, low-income,
and/or overburdened communities. EPA and USIBWC would perform additional public outreach as
necessary during the subsequent tiered NEPA analyses to explore and incorporate appropriate
mitigation measures to avoid, minimize, or compensate for these effects.
Operations under Projects E (APTP Phase 2), F (U.S.-side River Diversion), and J (Trash Boom[s])
would result in long-term operational emissions, a long-term increase in employee commuting to
the ITP parcel due to staff increases (for Project E), and a long-term increase in the use of heavy
trucks along roads between the ITP parcel and landfills (e.g., Otay Landfill) for disposal of solids
waste and/or trash. Project E would also include a new stationary source of emissions (occasional
operation of new emergency generator), which would not generate substantial emissions. These
operations would therefore result in long-term increases in criteria air pollutant emissions
(including PM2.5 and diesel PM) and traffic. As discussed in Sections 4.11 (Air Quality and Odor) and
4.17 (Transportation), all criteria pollutant emissions from operations (including PM) would be
very low compared to both GCR de minimis thresholds and San Diego AQIA trigger levels, with the
incorporation of pollution controls as described in Section 4.11 (Air Quality and Odor), and the
expected increase in counts of vehicles during operation would be very low compared to existing
average daily traffic volumes (with the potential exception of Project J, depending on the timing and
frequency of trash hauling activities). However, these impacts would occur in communities that
currently experience extremely high burdens for these specific environmental indicators in
addition to other social and environmental burdens. Therefore, these operational impacts under
Projects E, F, and J would be potentially significant when considered within the context of the
impacted communities. Additionally, because these impacts would occur predominantly within
minority, low-income, and/or overburdened communities, impacts to these communities would
appreciably exceed those to the general population (e.g., San Diego County as a whole). EPA and
USIBWC therefore considered these air quality and traffic-related impacts under Projects E, F, and J
to be potentially disproportionately high and adverse effects.
The U.S.-side river diversion for Project F and the trash boom(s) for Project J would potentially
detract from the visual character of the surrounding area. Project J would also result in the
accumulation of trash upstream of the trash boom(s) and in trash processing area(s) that may be
visible and produce objectionable odors. Projects F and J would potentially create conditions
conducive to the breeding and multiplication of disease vectors (e.g., mosquitoes, rodents, stray
dogs) that could impact public health in nearby minority and/or low-income communities. Because
these potentially significant impacts would occur predominantly within minority, low-income,
and/or overburdened communities, impacts to these communities would appreciably exceed those
to the general population (e.g., San Diego County as a whole). EPA and USIBWC therefore
considered these odor, visual, and public health and safety impacts under Project F and J to be
potentially disproportionately high and adverse effects.
Specific impacts to minority, low-income, and/or overburdened communities would be dependent
on the location and design of the river diversion, trash boom(s), and trash processing area(s); the
capture efficiency of the trash boom(s); and the frequency of trash extraction and disposal from the
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trash boom(s). The Supplemental Projects would be further defined, analyzed, and mitigated in
subsequent tiered NEPA analyses with input from the local community. EPA and USIBWC are
available to support the Mexican government in conducting targeted community outreach and
engagement, should the Mexican government request support
Due to the proximity to the U.S.-Mexico border and communities in Tijuana, the operational
activities described above at the ITP parcel—particularly under Projects E, I, and J—would
potentially result in long-term minor transboundary air quality and noise effects on receptors in
Mexico. These long-term impacts could contribute to existing socio-environmental vulnerabilities in
Mexico communities along the border.
Operations under Projects G (New SABTP) and H (Tijuana WWTP Treated Effluent Reuse) would
not result in any long-term impacts to minority, low-income, and/or overburdened communities in
the U.S. because these projects are substantially removed in distance from U.S. communities
(approximately 4 to 12 miles away from the EJ Study Area).
See Sections 4.8 (Visual Resources), 4.11 (Air Quality and Odor), 4.16 (Public Health and Safety),
4.17 (Transportation), and 4.19 (Socioeconomics) for additional discussions. See Section 4.21.5
(Cumulative Effects) regarding significant cumulative environmental justice impacts that require
mitigation, based on a review of the impacts of other past, present, or reasonably foreseeable
actions.
4.20.5 Comparative Analysis of the Alternatives
Table 4-38 provides a summary comparison of the impacts described above for the three evaluated
alternatives.
Two of the evaluated alternatives would, in the absence of mitigation, potentially result in
disproportionately high and adverse effects on minority, low-income, and/or overburdened
communities. Section 5 (Mitigation Measures and Performance Monitoring) identifies the
mitigation measures that would be implemented for the Core Projects and provides recommended
mitigation measures for the Supplemental Projects (which would be further refined and developed
in subsequent tiered NEPA analyses).
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Table 4-38. Comparative Analysis of Effects - Environmental Justice
Effect
Category
No-Action
Alternative
Alternative 1 (Core Projects)
Alternative 2
(Core and Supplemental Projects)
Temporary
effects
¦ None
¦ Significant and disproportionately high
and adverse effects due to minor
increases in criteria air pollutant
emissions (including PM2.5 and diesel
PM) and traffic associated with
extended construction for the
expanded ITP and new APTP in areas
currently experiencing extremely high
overburdens from PM2.5, diesel PM,
traffic impacts, and/or traffic proximity
(see Section 5 for potential mitigation
measures)
¦ Potential minor to moderate
transboundary air quality and noise
impacts to socio-environmentally
vulnerable communities in Mexico due
to construction at the ITP parcel
Same as Alternative 1, plus the
following:
¦ Potential additional increases in
significant and disproportionately high
and adverse effects due to minor
increases in PM2.5, diesel PM, and
traffic resulting from construction for
the expanded APTP, U.S.-side river
diversion, and trash boom(s) (see
Section 5 for potential mitigation
measu res)
¦ Potential minor increases in
transboundary air quality and/or noise
impacts to socio-environmentally
vulnerable communities in Mexico due
to additional construction at the ITP
parcel and/or for the U.S.-side river
diversion and trash boom(s)
Permanent
effects
¦ None
¦ Significant and disproportionately high
and adverse effects due to minor
increases in criteria air pollutant
emissions (including PM2.5 and diesel
PM) and traffic associated with
operations, commuting, and waste
hauling in areas currently experiencing
extremely high overburdens from
PM2.5, diesel PM, traffic impacts,
and/or traffic proximity (see Section 5
for potential mitigation measures)
¦ Significant and disproportionately high
and adverse effects due to
objectionable odor emissions from the
ITP anaerobic digestion process (see
Section 5 for potential mitigation
measures)
¦ Potential minor to moderate
transboundary air quality, odor, noise,
and/or traffic impacts to socio-
environmentally vulnerable
communities in Mexico due to
operations at the ITP parcel and/or
waste hauling and disposal
Same as Alternative 1, plus the
following:
¦ Potential additional increases in
significant and disproportionately high
and adverse effects due to minor
increases in PM2.5, diesel PM, and
traffic resulting from operation of the
expanded APTP, U.S.-side river
diversion, and trash boom(s) (see
Section 5 for potential mitigation
measu res)
¦ Potential significant and
disproportionately high and adverse
effects due to visual intrusions from
the U.S.-side river diversion and trash
boom(s) (see Section 5 for potential
mitigation measures)
¦ Potential significant and
disproportionately high and adverse
effects due to proximity to disease
vectors from the U.S.-side river
diversion and trash boom(s) (see
Section 5 for potential mitigation
measures)
¦ Potential minor increases in
transboundary air quality and noise
impacts to socio-environmentally
vulnerable communities in Mexico due
to additional operations at the ITP
parcel
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4.21 Other Sections Required by NEPA and CEQA
4.21.1 Unavoidable Adverse Effects
Unavoidable adverse effects are those that cannot be avoided should the Proposed Action be
implemented (40 CFR § 1502.16(a)(2)). Where practicable, mitigation would be incorporated to
reduce the adverse effects as specified in Section 5 (Mitigation Measures and Performance
Monitoring). Adverse impacts that cannot be eliminated through mitigation would be unavoidable.
Unavoidable adverse effects related to the Proposed Action would include the following:
• Reduction in surface water flows in the Tijuana River (Core and Supplemental Projects).
• Increased criteria pollutant and GHG emissions during construction and operations (Core
and Supplemental Projects).
• Increased production of wastewater treatment solids waste and trash that require disposal
at regional landfills (Core and Supplemental Projects).
• Increased traffic (i.e., commuter vehicles and trucks) on local roads during construction and
operations (Core and Supplemental Projects).
• Disproportionately high and adverse effects due to increased criteria air pollutant
emissions and traffic in communities currently experiencing extremely high overburdens
(Core and Supplemental Projects).
• Transboundary air quality and noise impacts to socio-environmentally vulnerable
communities in Mexico (Core and Supplemental Projects).
• Reduction in acreage of jurisdictional water resources (Supplemental Projects).
4.21.2 Relationship Between Short-Term Uses of the Environment and Maintenance and
Enhancement of Long-Term Productivity
Implementation of the Proposed Action would require short-term commitments of energy, raw
materials, and other resources during construction to further the overall purpose of providing
enduring, long-term enhancements to environmental quality and public health as described in
Section 1.4 (Purpose and Need for Action).
The Proposed Action would not result in any disruptions to short-term uses of resources or
negative effects on the long-term productivity of the Tijuana River Valley.
4.21.3 Irreversible and Irretrievable Commitment of Resources
The CEQ NEPA Implementing Regulations require that evaluation of environmental consequences
include discussion of irreversible or irretrievable commitments of resources needed for
implementation of the Proposed Action (40 CFR§ 1502.16 [a] [4]).
According to the CEQA Guidelines, evaluation of irreversible and irretrievable commitments should
be completed to ensure that consumption for the Proposed Action is justified (Cal. Code Regs. tit.
14, § 15126.2(d)). The irreversible and irretrievable commitment of resources refers to the use of
non-renewable resources such that their future removal or nonuse would be unlikely. A
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commitment of resources would also be considered irreversible and irretrievable if the resource is
consumed or destructed such that it could not be replaced, or if the resource is degraded to a point
such that there would be little possibility for its restoration.
Implementation of the Proposed Action would result in the irreversible and irretrievable
commitment of energy, material, human, and financial resources during construction and long-term
operation as discussed below.
The consumption of non-renewable fossil fuels would occur during construction activities and long-
term O&M of projects. Equipment and vehicles would use fossil fuels (e.g., gasoline, diesel) to
operate. Electricity would also be generated in part by non-renewable energy sources. However,
these energy sources would be readily available and their use for the Proposed Action would not
substantially increase energy demand or preempt future energy development or energy
conservation. Thus, the commitment of energy for the Proposed Action would have no adverse
impacts and would not be significant. See Section 4.14 (Energy) for additional discussion.
Construction of proposed infrastructure would require the use of building and fill materials. The
use of these materials would be irreversible and irretrievable. However, construction materials and
fill would be readily available and their use for the Proposed Action would not inhibit construction
for unrelated actions or substantially increase their demand. Therefore, the commitment of
material resources for the Proposed Action would have no adverse impacts and would not be
significant.
The use of human resources would be needed for construction activities, facility O&M, and truck
hauling for disposal of wastes during operations. Increased staffing needs could potentially strain
the availability of truck drivers for unrelated actions. However, the need for human resources could
help alleviate economic burdens in the Tijuana River Valley by providing employment
opportunities. Therefore, the commitment of human resources for the Proposed Action would have
no adverse impacts and would not be significant See Sections 4.17 (Transportation), 4.19
(Socioeconomics), and 4.20 (Environmental Justice) for additional discussion.
The expenditure of federal funding for implementation of the Proposed Action would commit funds
that would not be able to be used for other projects. However, these financial resources would
allow for a comprehensive solution to address transboundary pollution in the Tijuana River Valley.
Less-comprehensive projects and funding mechanisms may not be sufficient to address existing and
projected deficiencies described in Section 1.3 (Causes and Impacts of Contaminated
Transboundary Flows from Tijuana). The expenditure of funds would allow for EPA to meet the
goals and objectives of the USMCA Implementation Act and meet the purpose and need of the
Proposed Action as described in Section 1.4 (Purpose and Need for Action). Therefore, the
commitment of financial resources would not be considered significant.
As discussed above, the use of non-renewable energy sources would be required for
implementation of the Proposed Action. However, the use of non-renewable energy would be
considered minor in a regional context. In addition, the use of non-renewable energy would be
potentially offset by energy-saving equipment and operating strategies, and potential installation of
a biogas-fueled electric generator to offset other onsite energy consumption. See Section 4.14
(Energy) and Table 5-2 for additional discussion of energy use and conservation. Water would not
be used as a consumable resource except for minor consumption from existing water utility
connections required at proposed WWTPs for operations and thus the Proposed Action would not
deplete water resources. Additionally, some components of the Proposed Action—specifically,
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Projects H (Tijuana WWTP Treated Effluent Reuse) and I (ITP Treated Effluent Reuse)—would help
conserve water by providing opportunities for water reuse.
The Proposed Action would not require excessive use of natural resources. As an objective of the
Proposed Action, both Alternative 1 and Alternative 2 would aim to protect natural resources from
the negative effects of contaminated transboundary flows. Thus, the Proposed Action would help
conserve natural resources throughout the Tijuana River Valley and the Pacific Ocean. See Sections
4.1 (Freshwater and Estuarine Resources), 4.2 (Marine Waters), 4.3 (Floodplains), 4.4 (Inland
Biological Resources), 4.5 (Marine Biological Resources), 4.6 (Geological Resources), and 4.11 (Air
Quality and Odor) for respective discussions on potential impacts to natural resources.
4.21.4 Growth-Inducing Impacts
The CEQA Guidelines require that evaluation of environmental consequences include discussion of
growth-inducing impacts resulting from implementation of the Proposed Action (Cal. Code Regs. tit.
14, § Section 15126(e)). Growth-inducing impacts would be expected to occur if an action has
indirect or direct effects that would foster economic or population growth. The Proposed Action
would not result in direct growth-inducing impacts as it would not include construction or removal
of housing, displacement of people, or changes in land use that would alter planned population
densities.
As discussed in Section 4.19 (Socioeconomics), the Proposed Action would not be expected to have
significant effects on population growth or housing in the U.S.
Improved water quality would potentially restore recreational resources and reduce water quality-
related obstacles to economic growth in portions of the Tijuana River Valley and adjacent coastal
areas. While these beneficial effects could help reduce barriers to economic growth, these changes
would occur due to restoration of previously existing environmental conditions, rather than
through creation of new economic opportunities. Therefore, improved water quality would not
result in significant growth-inducing impacts.
Implementation of the Proposed Action would improve wastewater treatment capacity; however,
this improved capacity would not serve communities in the U.S. Therefore, improved wastewater
treatment capacity would not remove an obstacle to growth or foster economic or population
growth in the U.S., and would thus not result in growth-inducing impacts in the U.S.
More specifically, for Project A (Expanded ITP), Option A3, the 60-MGD expanded plant would
provide sufficient capacity to treat sewage from the Tijuana population under both initial operating
conditions (projected as 50 MGD in 2030) and projected conditions in 2050 (projected as 60 MGD
in 2050). While Option A3 would eventually provide sufficient reserve wastewater treatment
capacity to account for future population growth, this would not be considered a significant growth-
inducing impact given that insufficient treatment capacity does not currently inhibit population
growth in Tijuana. The existing lack of sufficient treatment capacity for wastewater from Tijuana
has proven to not be an obstacle to population growth, as the population in Tijuana has continued
to grow beyond the capabilities of the existing collection and treatment system. Thus, providing
additional capacity would not remove an obstacle to growth. Implementation of Option A3 would
be intended to reduce the impacts of projected population growth in Tijuana, rather than fostering
or promoting growth. Therefore, Option A3 would not result in significant growth-inducing impacts
in Tijuana.
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4.21.5 Cumulative Effects
The Proposed Action, in combination with other past, present, or reasonably foreseeable actions
within or near the Tijuana River Valley, could contribute to cumulative effects on certain
environmental resources. Cumulative effects can result from individually minor but collectively
significant actions taking place over a period of time (40 CFR§ 1508.1(g) [2022]). The extent of the
cumulative effects analysis is generally limited to the geographic/natural boundaries of the affected
resource areas. CEQ indicates that the geographic extent for the analysis can be defined on a case-
by-case basis and is dependent on the affected resources (CEQ, 1997c).
4.21.5.1 Past, Present, and Reasonably Foreseeable Actions within Geographic Scope of
Analysis
Table 4-39 lists the past, present, and reasonably foreseeable actions that EPA and USIBWC
considered in the cumulative effects analysis. These actions include those discussed in Section 2.9
(Related Projects), baseline conditions affecting existing communities, and additional projects or
actions that are known to occur in the Tijuana River Valley area that are unrelated to the Proposed
Action.
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Table 4-39. Past, Present, and Reasonably Foreseeable Actions Considered for Cumulative Effects
Action
Proponent
Location
Description
Status
Related Projects Included in Treaty Minute No. 328
1. Tijuana River diversion
CONAGUA, CESPT,
Mexico
Immediate Project B1 in Treaty Minute No. 328: Rehabilitated pump
Ongoing
rehabilitation
CI LA, EPA
station PB-CILA and constructed a new Tijuana River intake (already
completed as part of cost-sharing agreement with Mexico); rehabilitate
PB1-A and PB1-B.
2. Rehabilitation of the
CONAGUA, CESPT,
Mexico
Immediate Project B2: Rehabilitate the Buena Vista section of the Collector
Ongoing
Collector Oriente
EPA
Oriente sewer main and install 4,416 feet of pipelines in Tijuana to reduce
the risk of line failures and untreated wastewater discharges that could
affect the Tijuana River.
3. Rehabilitation of the
CONAGUA, CESPT,
Mexico
Immediate Project B3: Install a redundant line in Mexico to reduce the risk
Planned
International Collector
EPA
of line failures and untreated wastewater discharges that could affect the
(Phase 1)
Tijuana River.
4. Rehabilitation of line from
CESPT
Mexico
Immediate Project B4: Rehabilitate a portion of the pipeline in the
Planned
PB1-A to SABTP.
segment that conveys flows by gravity from PB1-A to SABTP by replacing
13,225 feet of pipeline.
5. Closing of the open gravity
CESPT
Mexico
Immediate Project B6: Encase approximately 19,685 feet of the open
Planned
channel from PB1-A to
gravity channel from PB1-A to the SABTP with a pipeline to close that
SABTP
section of the channel.
6. Conveyance of
CESPT
Mexico
Immediate Project B12: Lift station and force main to convey wastewater
Planned
wastewater from Sainz
from Sainz Canyon to the Arturo Herrera WWTP by constructing a pump
Canyon to Arturo Herrera
station and 5,577 feet of pipe with a capacity of 3.4 MGD.
7. Rehabilitation of
CESPT
Mexico
Immediate Project B13: Rehabilitate Matadero and Laureles 1 and 2 pump
Planned
Matadero and Laureles 1 & 2
stations by replacing pumps, installing a new Motor Control Center at each
pump stations
station, and installing a new preliminary treatment system in the lift
station at each station.
8. Construction of 18-MGD
CESPT
Mexico
Immediate Project B14: Construct a new 18-MGD capacity WWTP at SAB
Planned
SABTP
using an oxidation ditch process and constructing a 656-foot ocean outfall.
9. Construction of PB-1
CONAGUA, CESPT,
Mexico
Immediate Project B16: Construct a backup power supply system for the
Planned
backup power supply system
EPA
PB-1 electrical substation.
10. Reuse of effluent from La
CESPT
Mexico
Future Project Bl: Construct new conveyance facilities and associated
Planned
Morita and Arturo Herrera
infrastructure to permit use of Arturo Herrera and La Morita WWTP
WWTPs (Phase II)
treated effluent in Valle de las Palmas.
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Table 4-39. Past, Present, and Reasonably Foreseeable Actions Considered for Cumulative Effects
Action
Proponent
Location
Description
Status
Other Related Projects
11. Smuggler's Gulch trash
County of San
U.S.
Installed trash booms across the drainage swale in Smuggler's Gulch,
Completed
booms
Diego
downstream of the existing collector structure.
12. Trash fence in Matadero
CESPT
Mexico
Installed a trash wall/fence in Matadero Canyon roughly 2,000 feet south
Completed
Canyon
of the border to screen trash before it crosses the border into the U.S.
13. Rehabilitation of
CESPT
Mexico
Installed approximately 1.2 miles of pipelines and rehabilitated the Canon
Completed
Collector Poniente Segment
del Sainz-Los Reyes connection in Tijuana to reduce the risk of line failures
1A
and untreated wastewater discharges to the Tijuana River.
14. Sediment excavation in
City of San Diego
U.S.
Dredging and excavation of sediment from the Smuggler's Gulch channel,
Ongoing
Smuggler's Gulch and the
downstream from Smuggler's Gulch to the pilot channel, and in portions of
Tijuana River
the Tijuana River.
15. Trash boom in Los
Wildcoast and City
Mexico
Installed a trash boom in Los Laureles Canyon approximately 1.2 miles
Completed
Laureles Canyon
of Tijuana
south of the border.
16. Repair ITP junction box 1
USIBWC
U.S.
Repair JB-1 to restore gates and flow control for influent from the
Planned
(JB-1)
International Collector to the ITP.
17. Smuggler's Gulch
County of San
U.S.
Install a sediment capture basin and trash boom in Smuggler's Gulch to
Planned
sediment and trash capture
Diego
trap large trash/sediment flows and reduce downstream impacts. Widen
facility
existing culvert under Monument Road to reduce flooding.
18. Monument Road
CAState Parks
U.S.
Improve Monument Road downstream of Yogurt Canyon to ameliorate
Planned
Improvements at Yogurt
flooding.
Canyon
19. Continued operation of
USIBWC and City of
U.S.
Continued wastewater treatment operations at the ITP and SBWRP and
Ongoing
ITP and SBWRP
San Diego
discharge to the Pacific Ocean via the SBOO, in addition to any added
capacity under the USMCA project.
Other Actions
20. Tijuana River Border
CBP
U.S.
Install a bridge across the Tijuana River immediately downstream of the
Planned
Barrier Project
U.S.-Mexico border (between the existing concrete levees on either side of
the main channel), with a system of lift gates intended to prevent border
crossings via the river channel.
21. Tijuana River Valley
County of San
U.S.
Constructed a 79-acre campground featuring dozens of tent, RV, yurt, and
Completed
Regional Park campground
Diego Department
of Parks and
Recreation
equestrian campsites, along with nature education opportunities, an
amphitheater, and other amenities.
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Table 4-39. Past, Present, and Reasonably Foreseeable Actions Considered for Cumulative Effects
Action
Proponent
Location
Description
Status
22. Replacement, Operation,
CBP
U.S.
Replaced approximately 14 miles of primary pedestrian fence and made
Completed
and Maintenance of Tactical
other infrastructure improvements along the southwestern border of the
Infrastructure
U.S. between the City of Tijuana, Mexico and the City of San Diego,
California.
23. Rehabilitation of the
USIBWC
U.S.
Rehabilitate the levee system upstream of Dairy Mart Road to protect
Planned
levee system in the Tijuana
surrounding communities from a 100-year flood.
River Flood Control Project
24. Continued operation of
City of San Diego
U.S.
Continued wastewater treatment operations and discharge to the Pacific
Ongoing
Point Loma WWTP
Ocean through the Point Loma Ocean Outfall.
25. Vegetation maintenance
CBP
U.S.
Regular vegetation maintenance upstream of Dairy Mart Road Bridge to
ensure border security.
Ongoing
26. Tijuana Estuary Tidal
USFWS
U.S.
Restore approximately 80-87 acres of disturbed uplands and degraded
Planned (Draft
Restoration Project II Phase 1
wetlands in the southern arm of the Tijuana Estuary within the Tijuana
Slough NWR and Border Field State Park.
EIR/EIS
published August
2022)
27. Nelson Sloan Quarry
CDPR
U.S.
Consists of the beneficial re-use of excess sediment excavated from flood
Planned (Draft
Restoration and Beneficial
control facilities and disturbed habitats in the Tijuana River Valley towards
EIR published
Reuse of Sediment Project
the restoration of the Nelson Sloan Quarry.
September 2021)
28. Tijuana River Valley
County of San
U.S.
Refine and permit a network of multi-use recreational trails, which would
To Be
Regional Park Trails and
Diego Department
facilitate recreational access and allow for the rehabilitation of degraded
Determined
Enhancement Project
of Public Works
natural habitats within the Tijuana River Valley Regional Park.
29. Border wall remediation
CBP
U.S.
Improper compaction of soil and construction materials along a wall
To Be
and repairs
segment is causing dangerous erosion along a 14-mile stretch in San Diego,
California. DHS will begin necessary backfill projects to ensure the safety of
nearby border communities.
Determined
Other Conditions Affecting Tijuana River Valley Communities
30. Baseline conditions and
N/A
U.S. and
Stressors, such as emissions from traffic congestion and climate-driven
Ongoing
activities in overburdened
Mexico
risks/trends such as increased drought conditions, that contribute to
communities
environmental and human health impacts in overburdened communities.
31. Wastewater
N/A
Mexico
See Section 1.3.1 (Causes of Contaminated Transboundary Flows).
Ongoing
infrastructure failures
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4.21.5.2 Cumulative Effects Analysis
The majority of the identified past, present, and reasonably foreseeable actions or projects
considered in the cumulative effects analysis are intended to improve environmental conditions
and/or public health and safety in the Tijuana River Valley—for example, by restoring wetland
habitat or by preventing or capturing transboundary flows of trash and untreated wastewater.
These projects also do not encourage growth or qualify as major development projects, as they
neither increase housing nor provide new commercial or industrial opportunities to the
neighboring urban and suburban areas.
Due to the variety of projects analyzed as part of the Proposed Action and the scale of the
geographic area of analysis, the cumulative effects analysis is limited to a discussion of resource
areas affected by the Proposed Action that are of national, regional, and/or local significance and
that have non-beneficial impacts as a result of the Proposed Action.
The resource areas identified for discussion in the cumulative effects analysis are presented in
Table 4-40 along with a description of the geographic area of analysis considered in the analysis.
The cumulative effects of the Proposed Action in combination with past, present, and reasonably
foreseeable projects is discussed in the subsections below. Based on this analysis, EPA and USIBWC
identified potentially significant cumulative effects for air quality and environmental justice and
identified one additional mitigation measure, which is reflected in Section 5 (Mitigation Measures
and Performance Monitoring).
All Supplemental Projects should be reassessed for cumulative effects at the time of their
subsequent tiered NEPA analysis.
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Table 4-40. Cumulative Effects Analysis Scope and Project Matrix
Affected Resource of
National, Regional,
or Local Significance
Element(s) of Proposed Action That Would Result in
Non-beneficial Effect
Geographic Area of Analysis Associated with the
Affected Resource
Other Actions that
Affect the Resource in
the Geographic Area
(See Table 4-39)
Freshwater and
Estuarine Resources:
Hydrology
Construction in wetlands in the U.S.; operation of new
infrastructure in the U.S. and Mexico that would cause
a reduction in downstream Tijuana River flow
frequency and volume
The Tijuana River watershed
All actions (except
24)
Marine Waters and
Biological Resources
Increase in discharges of treated effluent to Pacific
Ocean via the SBOO; physical modification of SBOO
diffusers
Ocean waters from Point Loma to the U.S.-Mexico
border, extending out to the continental shelf
(approximately 10 miles offshore)
8, 19, 24, 31
Floodplains
Construction in the Tijuana River floodplain (e.g.,
between the north and south levees) for installation
of new infrastructure in the U.S.
The 100-year floodplain of the Tijuana River in the
U.S. that is upstream of Dairy Mart Road
20, 22, 23, 25
Inland Biological
Resources
Construction in the U.S.; operation of new
infrastructure in the U.S. and Mexico that would cause
a reduction in downstream Tijuana River flow
frequency and volume
Localized areas in the vicinity of construction
activities in the U.S. and habitat in areas
downstream of new infrastructure in the Tijuana
River Valley in the U.S.
All actions in the
U.S. (except 24)
Air Quality
Construction activities in the U.S. and Mexico (i.e.,
fugitive dust); operations of new infrastructure in the
U.S. (i.e., anaerobic digestion and combustion of
biogas at the expanded ITP and emissions from truck
hauling of solids for disposal); and operation of new
infrastructure in Mexico (i.e., emissions from truck
hauling of solids for disposal)
The San Diego air basin and Tijuana, Mexico
All actions (except
31)
Odor
Operation of the expanded ITP in the U.S.
Localized areas in the vicinity of the ITP (including
communities in and adjacent to the Tijuana River
Valley and Mexico communities near the ITP)
19, 31
GHG Emissions
See Air Quality
The San Diego air basin and Tijuana, Mexico
All actions (except
31)
Solid and Hazardous
Waste
Temporary construction activities that would produce
minor waste; and operations in the U.S. that would
produce wastewater process solids waste and trash
Regional landfills (including Punta Bandera3, Otay
Landfill, and Sycamore Landfill)
11, 12, 14, 15, 17,
19, 24 (and possibly
20)b
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Table 4-40. Cumulative Effects Analysis Scope and Project Matrix
Affected Resource of
National, Regional,
or Local Significance
Element(s) of Proposed Action That Would Result in
Non-beneficial Effect
Geographic Area of Analysis Associated with the
Affected Resource
Other Actions that
Affect the Resource in
the Geographic Area
(See Table 4-39)
Public Health and
Safety
Operation of new infrastructure in the U.S. (e.g., trash
booms and river diversion); and increasing staff
and/or facilities in areas susceptible to very high fire
severity and landslides
Areas along the U.S.-Mexico border and near the
proposed trash booms and river diversion in the
Tijuana River main channel
All Treaty Minute
No. 328 actions (1-
10), 11,13, 16,17,
31 (and possibly 20)
Transportation
Construction in the U.S. (i.e., use of heavy
equipment/vehicles); operations in the U.S. (i.e.,
employee commuting and truck hauling to dispose of
solids waste)
Public roads in the Tijuana River Valley (i.e., Dairy
Mart Road and the 1-5 interchange along with
access roads within the ITP parcel and Smuggler's
Gulch) and public roads leading to the disposal
facilities (including Punta Bandera in Mexico and
proposed regional facilities in the U.S.)
11,14,16,17,18,
19, 20, 21, 22, 23,
26, 27, 28, and 29
Environmental
Justice
Construction/operations in the U.S. (i.e., activities
resulting in air quality, transportation, and odor
impacts to overburdened and DACs)
EJ Study Area as defined in Section 3.20
(Environmental Justice)
All actions
a - Or an appropriate replacement disposal facility in Mexico.
b - This list includes actions that would be expected to result in long-term solid waste disposal requirements.
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Freshwater and Estuarine Resources: Hydrology
Certain projects of the Proposed Action (Projects C, D, E, F, and H) would reduce the frequency and
volume of flows in the Tijuana River that could, as a consequence, affect the hydrology of lower
reaches of the Tijuana River downstream of Dairy Mart Road Bridge, adversely affect infiltration to
groundwater, and decrease the availability of dry-weather surface flows for riparian vegetation and
habitat; see Section 4.1 (Freshwater and Estuarine Resources). Certain actions in Table 4-39
potentially accelerate these expected reductions in transboundary river flow frequency and volume
but do not result in additional reductions beyond those expected under the Proposed Action. For
example, Action 3 will reduce potential leaks from the International Collector to the Tijuana River
(e.g., via Stewart's Drain); this will potentially result in transboundary river flow reductions that
are currently attributed to Project C in Section 4.1 of this PEIS but could do so on a more
accelerated schedule. Similarly, if implementation of Action 1 allows PB-CILA to reliably divert 35
MGD, it will potentially result in transboundary river flow reductions that are currently attributed
to Project D in Section 4.1 of this PEIS but could do so on a more accelerated schedule. While
Actions 2 and 13 are aimed at preventing future potential line failures that otherwise could
contribute flows to the Tijuana River, implementation of these projects will not reduce existing
leaks or transboundary river flows.
Construction and operation of the Tijuana River Border Barrier (Action 20) has the potential to
impede transboundary river flows and thus affect river hydrology both upstream and downstream
of the U.S.-Mexico border. However, CBP has not made sufficient information available regarding
the barrier design (e.g., count, size, and locations of support columns; size and spacing of bars in lift
gates) or the expected operating protocols (e.g., conditions under which lift gates would be open or
closed) to support an assessment of the potential cumulative effects to river hydrology. EPA and
USIBWC will continue efforts to coordinate with CBP to resolve these concerns after completing this
Final PEIS and during preparation of subsequent tiered NEPA analyses. See the Floodplains section
of this analysis for further discussion.
Based on the above discussion, the actions in T able 4-39—with the possible exception of Action 20
if it impedes transboundary river flows—are not expected to contribute to potential adverse effects
related to downstream hydrology. Additionally, the transboundary river flow reductions due to the
Proposed Action would contribute to beneficial efforts (e.g., Action 26) to counteract the increasing
freshwater influence and restore tidal influence and salt marsh hydrology in the Tijuana River
Estuary.
Certain projects of the Proposed Action (Projects F and J) would have direct effects on jurisdictional
aquatic resources in the watershed, specifically upstream of Dairy Mart Road Bridge in the Tijuana
River. Actions 11,14,17, 20, and 26 in Table 4-39 also involve direct impacts to jurisdictional
aquatic resources in the Tijuana River Valley. Some actions (e.g., Action 26) are meant to restore
these resources while others include only minor negative impacts. For example, past construction
for Actions 11 and 14 were limited in size and scope and were not major construction or
development projects (e.g., pilings for boom installation and minor in-stream work for boom
installation) that destroyed aquatic resources. Current and future continued maintenance activities
associated with actions such as trash boom cleaning and sediment excavation (Actions 11,14, and
17) are part of efforts to improve hydrologic conditions in Smuggler's Gulch and the Tijuana River
and have limited effects at the time of the regular maintained activity. Cumulatively, direct effects
on jurisdictional aquatic resources do not result in removal of aquatic habitat nor do they create
substantial detrimental effects across the watershed.
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Based on the above, this analysis did not identify any significant cumulative effects on freshwater
and estuarine resources beyond those identified Section 4.1 (Freshwater and Estuarine Resources)
for the Proposed Action. No further mitigation is necessary.
Marine Waters and Biological Resources
Certain projects of the Proposed Action (Projects A, B, C, D, E, F, and H) would substantially increase
pollutant loadings from treated effluent discharged to the Pacific Ocean via the SBOO, which would
potentially increase pollutant concentrations in the area of nearfield dilution, depending on the
configuration of open SBOO diffuser ports; see Section 4.2 (Marine Waters).
Other actions in Table 4-39 contribute pollutant loadings to the Pacific Ocean offshore of southern
San Diego County, including continued discharges of treated effluent from the Point Loma WWTP
via the PLOO (Action 24), which have the potential to result in cumulative effects on marine water
quality and marine biological resources. While these discharges contribute pollutant loadings to the
existing conditions in the Pacific Ocean, the areas of nearfield dilution for the SBOO and PLOO do
not overlap. It is possible for large-ranging marine species (e.g., whales) to move between the areas
of nearfield dilution for each outfall and thus be impacted by both the Proposed Action and Action
24, resulting in cumulative effects such as direct ingestion, or indirect ingestion via prey, of
chemicals in the effluent. While these impacts may be additive, the cumulative effect is dependent
on the movement patterns of the marine species and would not affect all spatial extents equally due
to variations in ocean upwellings and current patterns that may carry effluent discharges unevenly
throughout the zones of initial dilution.
Additionally, the Proposed Action would provide net positive impacts to the Pacific Ocean by
ameliorating existing poor water quality conditions as discussed in Section 4.2 (Marine Waters),
including those caused by wastewater infrastructure failures (Action 31). While continued
operation of the SBWRP and ITP (Action 19) also results in the discharge of treated effluent via the
SBOO, the analyses in Section 4.2 (Marine Waters) and Appendix J (South Bay Ocean Outfall Plume
Transport Modeling) account for these cumulative effects by including existing and projected
treated effluent flows and pollutant loadings from these facilities (including BODs and nutrients) as
part of the evaluated baseline.
As discussed in Section 2.8 (Funding Sources and Binational Agreement), Project G (New SABTP) of
the Proposed Action and its corresponding project in Treaty Minute No. 328 (Action 8) are similar
in type and purpose. However, these projects differ in size (5 MGD vs. 18 MGD capacity) and
features (continued discharge to SAB Creek vs. construction of new ocean outfall) and are based on
substantially different assumptions regarding which wastewater flows would continue to require
treatment in Mexico and eventual discharge via SAB Creek. If Mexico implements Action 8 rather
than using U.S. appropriations to implement Project G, EPA and USIBWC anticipate that
improvements to marine water quality in the U.S. would be similar to those described in this PEIS
for the Proposed Action, provided that the new SABTP under Action 8 incorporates disinfection of
effluent prior to discharge.
Based on the above, this analysis did not identify any significant cumulative effects on marine
waters and biological resources—per the criteria in Section 4.2.1 (Standards of Significance) and
Section 4.5.1 (Standards of Significance)—beyond those identified in Section 4.2 (Marine Waters)
and 4.5 (Marine Biological Resources) for the Proposed Action. No further mitigation is necessary.
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Floodplains
Certain projects of the Proposed Action (Projects B, F, and J) would affect the 100-year floodplain of
the Tijuana River in the U.S. that is upstream of Dairy Mart Road. The Proposed Action would
require permanent development (Projects F and J) in both the 100-year floodplain and the
regulatory floodway (inside the levees) while Project B would include temporary work in the 100-
year floodplain outside the levees. Certain actions in Table 4-39 (Actions 20, 22, and 23) include
permanent development in the 100-year floodplain. In particular, construction and operation of the
Tijuana River Border Barrier (Action 20) has the potential to impede transboundary river flows and
thus impact river hydrology, which could increase the risk of catastrophic flooding during
significant storm events and the resulting impacts to surrounding communities and infrastructure.
However, CBP has not made sufficient information available regarding the barrier design (e.g.,
count, size, and locations of support columns; size and spacing of bars in lift gates) or the expected
operating protocols (e.g., conditions under which lift gates would be open or closed) to support an
assessment of the potential floodplain impacts resulting from Action 20. EPA and USIBWC will
continue efforts to coordinate with CBP to resolve these concerns after completing this Final PEIS
and during preparation of subsequent tiered NEPA analyses, which will consider potential
cumulative impacts to the levees providing floodwater protection and the regulated floodway.
Lastly, continued vegetation maintenance (Action 25) does not affect the levees and will continue to
benefit flood control by removing flow obstructions and vegetation from within the flood channel.
Certain projects of the Proposed Action (Project F) would temporarily affect the existing levee
surrounding the Tijuana River in the U.S. by installing piping under the south levee. This would not
affect the north levee where levee improvements (Action 23) are planned to take place, and no
projects of the Proposed Action would affect the levees near where the border fence replacement
(Action 22, which is already complete) occurred.
Based on the above, this analysis did not identify any significant cumulative effects on floodplains
per the criteria in Section 4.3 (Standards of Significance), with the possible exception of Action 20 if
further analysis reveals that the project increases flooding risk. No further mitigation is necessary.
Inland Biological Resources
All projects of the Proposed Action in the U.S. would result in temporary effects on inland wildlife
species, habitat, and/or sensitive natural communities, predominantly in localized areas in the
vicinity of construction activities for new infrastructure. Projects F and J would also result in
permanent effects on inland wildlife species and their habitat due to removal of riparian habitat for
installation of the diversion structure and trash boom; these effects would be analyzed in further
detail in the subsequent tiered NEPA analyses. See Section 4.4 (Inland Biological Resources). EPA
and USIBWC anticipate the conclusion of informal consultation with USFWS with concurrence with
the may affect but is not likely to adversely affect determination, as discussed in Section 7.2.1
(Consultation with USFWS).
Of the projects identified in Table 4-39, all actions in the U.S. have the potential to affect inland
biological resources on at least a temporary basis. Actions that involve construction activities with
heavy vehicles and that occur at the same time in the same vicinity as the Proposed Action will
potentially contribute to cumulative additive increases in noise effects on nearby species such as
nesting birds. The Nelson Sloan Quarry restoration (Action 27) will remove coastal sage scrub
habitat (and provide restoration for the removal) and potentially affect special-status species and
migratory birds in the vicinity of the quarry (e.g., coastal California gnatcatcher and Quino
checkerspot butterfly). Per the project's Draft Environmental Impact Report (EIR), Action 27 will
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include mitigation measures, such as preconstruction surveys and noise attenuation measures as
appropriate, to reduce potential effects on special-status species (CDPR, 2021).
Development of the Tijuana River Valley Regional Park campground (Action 21) removed
approximately 15 acres ofvegetation, based on a review of aerial imagery dated July 2021, and
could result in the grading of over 30 acres if the project is fully implemented; however, all impacts
are in disturbed, non-native vegetation (CDPR, 2018). Other actions (e.g., Actions 26 and 28)
involve habitat restoration and will have minor limited impacts on habitat. Actions that are subject
to the MSCP Subarea Plan and the City's MSCP are required to comply with the biological guidelines
and provisions set forth in those plans for compliance with applicable regulations. Construction
schedules of other actions in Table 4-39 are not all known, so it is not possible for EPA and USIBWC
to assess the potential for other temporary cumulative biological resource impacts during
construction.
The Proposed Action—in particular, the U.S.-side river diversion under Project F—would
potentially result in permanent effects on inland biological resources from reductions in
transboundary river flows that could potentially result in long-term disturbances of special-status
plant species that are associated with riparian habitat and could potentially affect the ability of
special-status fish to migrate in the Tijuana River. Certain infrastructure improvements in Mexico
(Actions 1-10) will potentially accelerate these expected reductions in transboundary river flow
frequency and volume but will not result in additional reductions beyond those expected under the
Proposed Action. See the Freshwater and Estuarine Resources: Hydrology section of this analysis
for further discussion.
Based on the above, this analysis did not identify any significant cumulative effects on inland
biological resources beyond those identified in Section 4.4 (Inland Biological Resources) for the
Proposed Action. No further mitigation is necessary.
Air Quality
All projects of the Proposed Action in the U.S. would result in direct emissions of criteria air
pollutants (e.g., VOCs, NOx, PM, and CO) during construction and/or operational activities, and
certain activities in Mexico (e.g., elements of Projects B and C) would potentially result in
transboundary emissions from construction activities; see Section 4.11 (Air Quality and Odor). All
actions in Table 4-39 are also expected to result in direct emissions through construction or
operational activities or as a result of existing baseline conditions in the Tijuana River Valley (e.g.,
air pollution from traffic congestion surrounding the San Ysidro Port of Entry). When considered
cumulatively, these combined effects are expected to be additive in nature and could contribute
negatively to overall air quality in the San Diego air basin.
Restoration of the former Nelson Sloan quarry (Action 27) will be concurrent with, and
immediately west of, Proposed Action construction activities at the ITP parcel. Quarry restoration
will result in dust (PMio) emissions from dumping sediment at the quarry and from heavy vehicles
used to haul large volumes of sediment to the project site. CDPR estimated that maximum daily
PMio emissions will be slightly below AQIA trigger levels (CDPR, 2021). It is possible that this
action, combined with PMio-emitting temporary construction activities under the Proposed Action
(e.g., grading and fill activities at the ITP parcel), will produce daily PMio emissions that exceed the
AQIA trigger levels and thus result in a significant cumulative effect. The Proposed Action includes
dust mitigation measures, but additional measures may be warranted for cumulative effects should
Action 27 and Proposed Action activities at the ITP parcel be implemented concurrently.
Construction schedules of other actions in Table 4-39 are not all known, so it is not possible for EPA
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and USIBWC to assess the potential for other temporary cumulative air quality impacts during
construction.
Based on the above, this analysis identified significant cumulative effects on air quality
resources—per the criteria in Section 4.11.1 (Standards of Significance)—beyond those identified
in Section 4.11 (Air Quality and Odor) for the Proposed Action. Consideration of further mitigation
is necessary. Specifically, EPA and USIBWC would coordinate with CDPR regarding construction
and operation schedules for the Proposed Action and quarry restoration activities to ensure, to the
extent practicable, that activities with potential to generate substantial dust emissions do not take
place concurrently (e.g., grading, fill, or sediment hauling activities at the ITP parcel taking place
concurrently with sediment hauling and deposition at the quarry).
Odor
Certain projects of the Proposed Action (Project A and, to a lesser extent, Project D) would
potentially create objectionable odors in communities near the ITP—in both the U.S. and Mexico—
due to H2S emissions from expanded wastewater treatment operations and a new anaerobic
digestion process. Of the actions identified in Table 4-39, operation of the existing ITP (Action 19)
potentially contributes to objectionable odors in communities near the ITP, and existing
wastewater infrastructure failures (Action 31) are known to contribute objectionable odors in the
Tijuana River Valley by causing or contributing to transboundary flows of untreated wastewater.
While odors from the existing ITP (Action 19) do present a potential cumulative effect, the
Proposed Action is specifically intended to reduce contaminated transboundary flows, including
those caused by existing wastewater infrastructure failures (Action 31).
Based on the above, this analysis did not identify any significant cumulative effects on odor beyond
those identified in Section 4.11 (Air Quality and Odor) for the Proposed Action. No further
mitigation is necessary.
GHG Emissions
All projects of the Proposed Action would result in increases in GHG emissions (Scope 1, Scope 2,
and/or Scope 3) from both construction and operational activities. Of the actions identified in Table
4-39, all actions except Action 31 are also expected to contribute GHG emissions from construction
and, in some cases, operational activities. Per CEQ guidance, the analysis of the effects of GHG
emissions is essentially a cumulative effects analysis that is included in the general discussion of
climate change impacts; the direct and indirect effects analysis therefore adequately addresses
cumulative climate change effects from the Proposed Action (CEQ, 2016). See Section 4.12 (Climate)
for the direct and indirect effects analysis.
Based on the above, this analysis did not identify any significant cumulative effects on climate
beyond those identified in Section 4.12 (Climate) for the Proposed Action. No further mitigation is
necessary.
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Solid and Hazardous Waste
Certain projects of the Proposed Action (Projects A, D, E, and J) would affect regional landfills—
including Punta Bandera in Mexico,70 and Otay Landfill and Sycamore Landfill in the U.S.—due to
their long-term solid waste disposal requirements for wastewater treatment processes solids waste
or trash as discussed in Section 4.13 (Solid and Hazardous Waste). Certain actions in Table 4-39
(Actions 11,12,14, and 17) are also expected to produce long-term operational wastes (i.e., trash
extracted from trash booms or sediment removed from sediment capture basins) to be sent to
regional disposal facilities in the U.S. if reuse is not feasible. As discussed in Section 3.13 (Solid and
Hazardous Waste), regional landfills such as Otay and Sycamore Landfills have available capacity,
which EPA and USIBWC expect to be sufficient to account for incoming wastes from these actions.
Additionally, to the extent that these regional landfills are already accepting wastes from these
actions, the "Projected Cease Operation Date" in Table 3-12 should already account for these waste
disposal requirements. For actions that are disposing of sediment, reuse options in the area will
include the proposed Nelson Sloan Quarry restoration (Action 27). Separately, continued operation
of the ITP and the SBWRP (Action 19) and the Point Loma WWTP (Action 24) will continue to
produce long-term wastewater treatment process solids that require disposal. Specifically, Action
19 results in solids waste that is sent to the Punta Bandera facility in Mexico from the ITP and, in
the case of the SBWRP, conveyance of sludge to the Point Loma WWTP for disposal or beneficial
reuse. For Action 19, the solids waste produced by the existing ITP is analyzed as part of the current
conditions in the analysis described in Section 4.13 (Solid and Hazardous Waste); this existing
disposal requirement already informs Mexico's decision to seek out a replacement for the Punta
Bandera facility. Under the Proposed Action—specifically, Project A (Expanded ITP)—solids waste
disposal requirements from the ITP would initially decrease due to anaerobic digestion of all
primary and secondary sludge from the ITP, with the increase in solids waste occurring in later
years (between 2030 and 2050) as the additional treatment capacity comes into service in response
to population growth, depending on the design option. Implementation of Project A, since it would
reduce solids waste hauled to Punta Bandera in the initial phases of operation, would help prolong
the time Mexico has to find a suitable replacement facility before Punta Bandera must close.
EPA and USIBWC do not have sufficient information regarding the trash boom in Los Laureles
Canyon (Action 15) or the proposed Tijuana River Border Barrier (Action 20) to support an
assessment of cumulative waste disposal requirements.
Based on the above, this analysis did not identify any significant cumulative effects on solid and
hazardous resources per the criteria in Section 4.13.1 (Standards of Significance). No further
mitigation is necessary.
Public Health and Safety
Certain projects of the Proposed Action (Projects F and J) would affect public health and safety.
Specifically, Project J would increase unsafe field conditions for CBP personnel conducting
inspections near or within areas of accumulated trash, and Projects F and J would introduce
potential breeding areas for disease-spreading vectors.
70 Or an appropriate replacement disposal facility in Mexico.
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Contaminated transboundary flows due to wastewater infrastructure failures (Action 31)
contribute to poor and unsafe working conditions where CBP personnel operate along the border.
However, the Proposed Action and certain infrastructure improvements in Mexico (Actions 1-10,
13, and 16) would reduce contaminated transboundary flows and thus improve field conditions for
CBP personnel that work in and around those flows.
Trash booms and barriers installed under Action 11 (completed) and Action 17 (proposed) have
the potential to create conditions conducive to the breeding and multiplication of disease vectors
(e.g., mosquitoes, rodents, stray dogs), similar to Project J. However, the locations of trash booms in
Smuggler's Gulch under Actions 11 and 17 are at least 1.5 miles away from the locations of booms
under Project J. Existing wastewater infrastructure failures (Action 31) do currently provide
potential breeding areas in the form of stagnant and pooled waters from contaminated
transboundary flows. However, the Proposed Action is specifically intended to reduce
contaminated transboundary flows, including those caused by existing wastewater infrastructure
failures.
EPA and USIBWC do not have sufficient information regarding the proposed Tijuana River Border
Barrier (Action 20) to support an assessment of cumulative effects on public health and safety (e.g.,
due to trash accumulation and creation of stagnant, pooled waters).
Based on the above, this analysis did not identify any significant cumulative effects on public health
and safety beyond those identified in Section 4.16 (Public Health and Safety) for the Proposed
Action. No further mitigation is necessary.
Transportation
Certain projects of the Proposed Action (Projects A, B, D, E, F, I, and J) would affect public roads by
increasing the number of vehicles on local roads during construction and/or operations in the
Tijuana River Valley and on roads leading to the disposal facilities (including Punta Bandera in
Mexico and Otay Landfill and/or Sycamore Landfill in the U.S.). The Proposed Action would
increase trucking along disposal routes, increase AADT resulting from an increase in employee
commuting at the ITP parcel, increase traffic for construction activities, and result in temporary
traffic configurations during construction. Certain actions in Table 4-39 (Actions 16,17,18, 20, 21,
22, 23, 26, 28, and 29) are expected to add to a cumulative increase in construction-related traffic
within and near the Tijuana River Valley. However, several of these projects are already complete,
and others such as Action 20 are expected to be complete before the start of any Proposed Action
construction activities in the Tijuana River Valley. Construction schedules of other planned actions
are not known, so it is not possible for EPA and USIBWC to assess the potential for temporary
cumulative transportation impacts during construction.
Actions 14,17, and 27 are expected to generate long-term operational transportation impacts in the
U.S. from truck hauling of excavated sediment for disposal. Under current sediment management
practices within the Tijuana River Valley (including Action 14), sediment extracted from the Goat
Canyon sediment basin, Smuggler's Gulch, the Tijuana River, and the Tijuana River pilot channel is
hauled by heavy trucks to regional landfills and other off-site placement locations. This occurs
seasonally over a period of approximately three to four months per year. Installation of a new
sediment capture basin in Smuggler's Gulch (Action 17) is expected to increase the amount of
sediment captured at this site and the associated hauling requirements. The Nelson Sloan Quarry
restoration (Action 27), which will be underway before construction begins under the Proposed
Action, will effectively redirect all seasonal Tijuana River Valley sediment management truck
activity to the quarry as the deposition site. Trucks will access the quarry via an improved dirt
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driveway off of Monument Road, approximately 0.25 miles west of the ITP parcel. CDPR determined
that traffic impacts from the quarry restoration would be well below City of San Diego screening
thresholds for significance (CDPR, 2020) and that the project would reduce overall truck trips and
VMT by reducing the need to haul excess sediment from within the Tijuana River Valley to regional
landfills and other off-site placement locations (CDPR, 2021).
Actions 11 and 17 are expected to generate long-term operational transportation impacts in the U.S.
from truck hauling of trash (from trash booms/barriers) for disposal. However, these hauling
activities are expected to take place infrequently and likely no more than several days per year.
Continued operation of the ITP and SBWRP (Action 19) generates long-term operational
transportation impacts in the U.S. from employee commuting, which is presumably reflected in the
baseline AADT counts provided in Section 3.17 (Transportation).
Cumulatively, these actions, combined with the Proposed Action, potentially increase the amount of
long-term truck and traffic impacts in the Tijuana River Valley (e.g., along Monument Road and
Dairy Mart Road) but are not expected to result in substantial increases in traffic volumes in
residential or congested areas beyond those potential increases under Project J.
Based on the above, this analysis did not identify any significant cumulative effects on
transportation resources—per the criteria in Section 4.17.1 (Standards of Significance)—beyond
those identified in Section 4.17 (Transportation) for the Proposed Action. No further mitigation is
necessary.
Environmental Justice
As discussed in Section 4.20 (Environmental Justice), air quality, odor, and transportation impacts
from the Proposed Action would occur in communities that currently experience high or extremely
high burdens for these specific environmental indicators in addition to other social and
environmental burdens. As discussed above, this analysis identified potential significant cumulative
effects on air quality due to the cumulative PMio emissions from Proposed Action construction
activities and other actions—specifically, the Nelson Sloan Quarry restoration (Action 27). These
temporary, cumulative air quality impacts could contribute to existing socio-environmental
vulnerabilities in communities along the U.S.-Mexico border and overburdened communities in the
U.S. This underscores the need to implement the additional mitigation identified in the Air Quality
discussion above.
Additionally, and as described throughout this cumulative effects analysis, many of the actions in
Table 4-39 that are intended to mitigate contaminated transboundary flows involve temporary
construction-related impacts. These temporary impacts are generally located within or near
communities that currently experience high or extremely high social and environmental burdens.
In contrast, the long-term environmental benefits of these projects will include substantial benefits
to downstream and coastal communities that generally do not currently experience a similarly
elevated degree of social and environmental burdens. This cumulative inequity in the distribution
of construction-related impacts and environmental benefits further underscores the
disproportionately high and adverse effects identified in Section 4.20 (Environmental Justice) and
the associated need for mitigation.
Baseline conditions and activities in overburdened communities (Action 30) are an inherent
component of the affected environment and environmental consequences discussions in Sections
3.20 (Environmental Justice) and 4.20 (Environmental Justice), respectively. There are no new
4-139
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Environmental Consequences
cumulative effects identified as a result of Action 3 0 in this analysis that are not previously
discussed in Section 4.20.
Wastewater infrastructure failures (Action 31) currently cause transboundary flows that convey
environmental contaminants into predominantly minority, low-income, and/or overburdened
communities in the U.S. However, the Proposed Action and most actions in Table 4-39 (Actions 1-17
and 19) are specifically intended to reduce contaminated transboundary flows, including those
caused by existing wastewater infrastructure failures (Action 31), such that the cumulative effect is
a lessening of these impacts to minority, low-income, and/or overburdened communities in the U.S.
Based on the above, this analysis identified cumulative effects that are significant and
disproportionately high and adverse impacts—per the criteria in Section 4.20.1 (Standards of
Significance)—beyond those potentially significant impacts identified in Section 4.20
(Environmental Justice) for the Proposed Action. Consideration of further mitigation is necessary.
Specifically, and as noted in the Air Quality section of this analysis, EPA and USIBWC would
coordinate with CDPR regarding construction and operation schedules for the Proposed Action and
quarry restoration activities to ensure, to the extent practicable, that activities with potential to
generate substantial dust emissions do not take place concurrently (e.g., grading, fill, or sediment
hauling activities at the ITP parcel taking place concurrently with sediment hauling and deposition
at the quarry).
4-140
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
5. MITIGATION MEASURES AND PERFORMANCE MONITORING
Mitigation measures are those that avoid, minimize, or compensate for effects caused by a proposed
action or its alternatives as described in an environmental document, and are committed to by the
agency in the decision document (e.g., the ROD for an EIS) as appropriate. Mitigation can include
avoiding the impact altogether; minimizing impacts by limiting the degree or magnitude of the
action and its implementation; rectifying the impact by repairing, rehabilitating, or restoring the
affected environment; reducing or eliminating the impact over time by preservation and
maintenance operations during the life of the action; or compensating for the impact by replacing
or providing substitute resources or environments (40 CFR § 1508.1 (s)).
EPA and USIBWC have identified mitigation measures associated with the Proposed Action that will
be included in the decision as determined necessary throughout the NEPA process.
This section also addresses the performance monitoring mechanisms that would be used to assess
water quality, human health, and environmental outcomes resulting from implementation of the
Proposed Action.
5.1 Summary of Significant Impacts and Mitigation
Significant impacts for each Alternative were evaluated in Section 4 (Environmental Consequences)
and are summarized by resource area in Table 5-1. EPA and USIBWC have determined that a
portion of these significant impacts would require mitigation as noted in the table. Table 5-1
includes indicators to show which Alternative(s) result in the significant impact
A summary of applicable mitigation measures for the Core and Supplemental Projects is included in
Table 5-2. For Supplemental Projects, future tiered NEPA analyses may identify additional
mitigation measures required for implementation. Table 5-2 includes indicators to show whether
the mitigation measures are necessary to address a significant impact listed in Table 5-1. For
Supplemental Projects, mitigation measures are identified in order to solicit public comment on the
measure to inform the tiered framework established by this programmatic document Mitigation
measures for Supplemental Projects will not be included in the ROD as committed measures but
instead will be carried forward and revised as appropriate as measures in subsequent tiered NEPA
analyses for the Supplemental Projects.
5-1
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-1. Significant Impacts to be Mitigated
Significant Impact
No-Action
Alternative
Alternative 1
(Core Projects)
Alternative 2
(Comprehensive
Solution)
Freshwater and Estuarine Resources
Continuation of impacts to freshwater and estuarine resources and water quality degradation
X
Potential impacts to potential jurisdictional water of the U.S. for construction of U.S.-side river diversion
and trash boom(s) in Tijuana River main channel and floodplain
©
Potential permanent reduction in acreage of potential jurisdictional water resources in the Tijuana River
floodplain for the U.S.-side river diversion and trash boom[s] requiring an individual CWA 404 permit
©
Marine Waters
Continuation, and worsening over time, of existing marine water quality impacts
X
Substantial increase in pollutant loadings to Pacific Ocean via the SBOO
¦
¦ ©
Floodplains
[None identified]
Inland Biological Resources
Continuation of negative effects on inland biological resources resulting from contaminated transboundary
flows
X
Potential short-term substantial disturbances of special-status wildlife and fish species during construction
in Tijuana River main channel and floodplain, depending on the locations of the proposed river diversion
and trash boom(s)
©
Potential long-term substantial disturbances of special-status plant and wildlife species associated with
downstream riparian habitat due to reduced wet-weather transboundary flows
©
Potential long-term reduction in special-status fish migration ability and/or estuarine rearing conditions
due to reduced wet-weather transboundary flows
©
Marine Biological Resources
[None identified]
Geological Resources
[None identified]
Cultural Resources
[None identified]
Visual Resources
Potential detraction from the visual character or quality of the localized area due to introduction of
physical structures, land conversion, and O&M associated with the U.S.-side river diversion and trash
boom(s)
©
5-2
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-1. Significant Impacts to be Mitigated
Significant Impact
No-Action
Alternative
Alternative 1
(Core Projects)
Alternative 2
(Comprehensive
Solution)
Potential disproportionately high and adverse effect due to visual intrusions from U.S.-side river diversion
and/or trash boom(s)*
©
Land Use
[None identified]
Coastal Zone
[None identified]
Air Quality and Odor
Potential objectionable odor emissions from UP anaerobic digestion process
¦
¦ ©
Potential objectionable odors and/or impacts to sensitive receptors due to trash boom operations
©
Disproportionately high and adverse effect due to minor increase in PM2.5 and diesel PM emissions (due to
construction, operations, and/or commuting) in areas that currently experience extremely high
overburdens from PM2.5 and diesel PM*
¦
¦ ©
Disproportionately high and adverse effect due to objectionable odor emissions from UP anaerobic
digestion process*
¦
¦ ©
Potential for cumulative daily PM10 emissions (from the Proposed Action and concurrent restoration
activities at the nearby Nelson Sloan Quarry) to exceed AQIA trigger levels and result in disproportionately
high and adverse effect*
¦
¦ ©
Climate
Inconsistent with the City of San Diego Climate Action Plan due to an increase in GHG emissions
¦
¦ ©
Solid and Hazardous Waste
[None identified]
Energy
[None identified]
Public Services and Utilities
Potential impedance to CBP operations due to U.S.-side river diversion and trash boom(s)
©
Public Health and Safety
Exacerbation of unsafe field conditions for CBP personnel
X
Exacerbation of water quality issues at public beaches
X
Increase in unsafe field conditions for CBP personnel due to trash boom(s)
©
Introduction of breeding areas for disease-spreading vectors due to U.S.-side river diversion and trash
boom(s)
©
5-3
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project Mitigation Measures and Performance Monitoring
Table 5-1. Significant Impacts to be Mitigated
Significant Impact
No-Action
Alternative
Alternative 1
(Core Projects)
Alternative 2
(Comprehensive
Solution)
Potential disproportionately high and adverse effect due to proximity to disease vectors from U.S.-side
river diversion and/or trash boom(s)*
©
Transportation
Potential substantial localized increases in traffic volumes and congestion from Project J, depending on
frequency of trash hauling
©
Disproportionately high and adverse effects due to minor increases in traffic associated with operations,
commuting, and waste hauling in areas currently experiencing extremely high overburdens from traffic
impacts and/or traffic proximity*
¦
¦ ©
Noise
Potential localized, short-term exceedances of city and county noise levels during construction
¦
¦ ©
Potential for substantial, short-term increases in noise levels during construction in specific areas near
noise-sensitive receptors (e.g., protected species habitat and recreational areas in Smuggler's Gulch;
residences immediately adjacent to portions of Monument Rd)
¦
¦ ©
Potential long-term impacts from increase in noise due to continuous (or near-continuous) operation of
biogas-fired engine and electrical generator
¦
¦ ©
Socioeconomics
[None identified]
Environmental Justice
[See disproportionately high and adverse effects identified with an asterisk (*) listed in Visual Resources, Air
Quality and Odor, Public Health and Safety, and Transportation sections above in this table.]
* Indicates a disproportionately high and adverse effect that was identified in the environmental justice analysis (see Section 4.20 [Environmental Justice] or
the environmental justice portion of the cumulative effects analysis (see Section 4.21.5 [Cumulative Effects]).
Symbol key:
X Significant impact is a result of the No-Action Alternative.
¦ Significant impact is a result of a Core Project(s).
© Significant impact is a result of a Supplemental Project(s).
¦ © Significant impact is a result of both a Core and Supplemental Project(s).
5-4
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Alternative 1
Mitigation Measure
Project Phase
Alternative 2
A
B
C
D
E
F
G
H
1
J
Water Resources (Includes Freshwater and Estuarine, Marine, and Floodplains)
WR-1: Adherence to NPDES permit conditions (operational effluent limitations,
Operation
¦
¦
©
monitoring requirements, etc.).
WR-2: Acquisition of CWA Section 404 permit authorization(s) and adherence to CWA
Planning,
404 permit conditions, if applicable; water quality certification or waste discharge
Construction,
~
©
©
permit from RWQCB.
Operation
WR-3: Adherence to erosion and sediment control measures and prevention
Construction
procedures in accordance with a project-specific Stormwater Pollution Prevention
~
~
~
©
©
©
©
Plan (SWPPP) prepared by a certified Qualified SWPPP Developer and approved by the
San Diego Water Board.
WR-4: Incorporation of stormwater runoff control measures, procurement of state
Planning,
stormwater permits, development of a Stormwater Quality Management Plan and
Construction
~
~
~
©
©
©
©
Spill Prevention Plan that include BMPs for minimizing stormwater runoff, erosion,
and potential water quality impacts.
WR-5: Avoidance of wetlands (through use of trenchless methods for channel
Construction
©
crossings or through relocation of pipeline).
WR-6: Limiting construction activities in the Tijuana River floodplain to the dry season.
Construction
©
©
WR-7: Use of remote assessment tools for inspections of infrastructure in the 100-
Operation
©
©
year floodplain and regulatory floodway.
WR-8: Implementation of a pilot-scale trash boom study and further hydrologic
Planning
©
©
modeling.
Biological Resources (Inland and Marine)
BR-1: (General) Confine all heavy equipment, vehicles, and construction activities to
Construction
existing access roads, road shoulders, and disturbed/developed or designated work
~
~
~
©
©
©
©
areas. Limit work areas to what is necessary for construction.
BR-2: (General) All materials imported into the Action Area (e.g., straw wattles,
Construction
gravel, and mulch) will be obtained from certified sources that are free of noxious
~
~
~
©
©
©
©
weeds.
5-5
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Mitigation Measure
Project Phase
Alternative 1
Alternative 2
A
B
C
D
E
F
G
H
1
J
BR-3: (General) Wash stations will be set up at all vehicle entrances into the Action
Area to remove plant material, mud and dirt from vehicles before entering the Action
Area. Sediment accumulated from the washing will be removed daily and placed in a
sealed container for disposal in an approved landfill. Project workers will use boot
brushes, a metal scraper, soap, water and scrub brushes to remove mud, debris, and
plant materials found on their clothing and personal equipment.
Construction
~
~
~
©
©
©
©
BR-4: (General) BMPs for erosion control, stormwater runoff, hazardous material
handling, and stockpile management will be implemented to prevent pollution caused
by construction operations and to reduce contaminated stormwater runoff.
Construction
~
~
~
©
©
©
©
BR-5: (General) All construction equipment will be inspected for leaks prior to being
brought onsite. All equipment shall be well maintained and inspected daily while
onsite to prevent leaks of fuels, lubricants or other fluids into wetlands and
waterways.
Construction,
Operation
~
~
~
©
©
©
©
BR-6: (General) Service and refueling procedures will be conducted in a designated
area where there is no potential for fuel spills to seep or wash into waterways.
Construction,
Operation
~
~
~
©
©
©
©
BR-7: (General) No pets, hunting, open fires (such as barbecues), or firearms will be
permitted at the project site.
Construction,
Operation
~
~
~
©
©
©
©
BR-8: (General) Project lighting will be of the lowest illumination necessary for safety
and will be directed toward the construction area and away from sensitive habitats, as
feasible. Light glare shields will be used to reduce the extent of illumination into
sensitive habitats. In particular, use of lighting that causes direct illumination into
sensitive habitats (e.g., riparian and coastal sage scrub) would be avoided during the
period from one hour past sunset through one hour before sunrise.
Construction,
Operation
~
~
~
©
©
©
©
BR-9: (General) Ground disturbance and vegetation removal should not exceed the
minimum amount necessary to complete work at the site.
Construction
~
~
~
©
©
©
©
BR-10: (General) All areas where revegetation is required will be replanted with
native species. A native plant restoration and monitoring plan will be developed by a
qualified botanist in coordination with USFWS.
Construction
~
~
~
©
©
©
©
5-6
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Mitigation Measure
Project Phase
Alternative 1
Alternative 2
ABCDEFGHI J
BR-11: (Special-status Species) A qualified biologist will develop an environmental
training and will present the training to all crew members prior to them beginning
work on the project. The training will include a description of special-status species
with potential to occur, life history and habitat associations, general protection
measures, the terms and conditions of project permits, penalties for non-compliance,
and the boundaries of the construction areas. A handout will be provided to all
participating personnel and at least one copy will be kept onsite during construction
activities. Upon completion of the training, crew members will sign a form stating that
they attended and understood the training.
Construction
©
©
©
©
BR-12: (Special-status Species) Preconstruction surveys for special-status wildlife
species shall be conducted within seven days prior to construction initiation. Surveys
will be conducted by qualified biologists with appropriate knowledge and experience
in the life history, ecology, and identification of special-status species that may be
encountered.
Construction
©
©
©
©
BR-13: (Special-status Species) A focused survey for vernal pools will be conducted in
the project area no less than one year prior to construction. If any vernal pools are
found, they will be flagged and fully avoided. If full avoidance is infeasible, USFWS-
protocol San Diego fairy shrimp surveys will be conducted. If fairy shrimp are found to
inhabit any vernal pools that cannot be completely avoided, ESA Section 7
consultation with USFWS will be reinitiated, and a mitigation plan will be developed.
Planning,
Construction
©
©
©
©
BR-14: (Special-status Species) A qualified biologist will conduct a preconstruction
survey for Quino checkerspot butterfly host plants in areas of suitable habitat that
may be impacted by construction (including staging areas) during appropriate
blooming periods (to ensure host plants are correctly identified) no less than one year
prior to construction. If found, areas containing host plants will be flagged and
avoided.
Planning,
Construction
©
©
©
©
BR-15: (Special-status Species) Sensitive biological resources (e.g., vernal pools,
nesting birds, listed plants, Quino checkerspot butterfly host plants, other sensitive
wildlife) identified in or adjacent to construction work areas during preconstruction
surveys will be clearly marked or flagged in the field. Such areas will be avoided during
construction as detailed in relevant species-specific measures below.
Construction
©
©
©
©
5-7
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Alternative 1
Mitigation Measure
Project Phase
Alternative 2
A
B
C
D
E
F
G
H
1
J
BR-16: (Special-status Species) Erosion control materials shall be installed per
Construction
manufacturing material specifications and must not contain monofilament netting.
~
~
~
©
©
©
©
Only tightly woven netting or similar material will be used for all geo-synthetic erosion
control materials such as coir rolls and geo-textiles.
BR-17: (Special-status Species) All construction personnel will visually check for
Construction
wildlife on or beneath vehicles and construction equipment before moving or
~
~
~
©
©
©
©
operating them.
BR-18: (Special-status Species) If listed wildlife is observed within the work area or its
Construction,
immediate vicinity, work will stop until the animal leaves the area of its own volition.
The animal will not be harried or harassed into leaving the area. If the animal does not
Operation
~
~
~
©
©
©
©
leave of its own accord, contact the Project biologist for further guidance.
BR-19: (Special-status Species) During project activities, all trash that may attract
Construction,
wildlife will be properly contained in covered garbage receptacles. Following
Operation
~
~
~
©
©
©
©
construction, all trash and construction debris from project sites will be removed.
BR-20: (Special-status Species) Impacts from fugitive dust during construction will be
Construction,
avoided and minimized through watering, limiting vehicle speeds to 20 miles per hour,
Operation
~
~
~
©
©
©
©
controlling vehicle access, and other appropriate measures.
BR-21: (Special-status Species) At the end of the day, all steep-sided excavations
Construction
more than 2 feet deep will either be covered or be provided with one or more ramps
installed at an angle of no more than 45 degrees to allow egress. Covers and ramps
~
~
~
©
©
©
©
shall be constructed of earth material or plywood (or similar material). All excavations
will be inspected prior to backfill or grading to ensure that no listed species are
trapped within.
5-8
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Mitigation Measure
Project Phase
Alternative 1
Alternative 2
A
B
C
D
E
F
G
H
1
J
BR-22: (Special-status Species) For project activities conducted during the migratory
bird breeding season (February 1 to August 15), a preconstruction nest survey will be
conducted. Surveys will include ground nesting birds and raptors within 300 feet of
the project area. Species-specific surveys for least Bell's vireo and California
gnatcatcher will be conducted as described below in measures 23 and 24. If active
nests (i.e., nests containing eggs or young) are identified, a no-disturbance buffer zone
will be established around the nest using flagging, fencing, and/or signage as
appropriate. No construction activities will occur within the buffer zone until a
qualified biologist has determined that the young have fledged or that construction
activities within the buffer zone are not disturbing the nesting birds. The width of the
buffer zone will be determined by a qualified biologist in coordination with CDFW;
recommended buffers are 500 feet for raptors and 100 feet for other birds. If the
project is delayed longer than two weeks during breeding season, an additional survey
will be necessary.
Construction
~
~
~
©
©
©
©
BR-23: (Special-status Species) To the greatest extent practicable, work within 300
feet of suitable least Bell's vireo habitat (i.e., riparian habitat associated with
Smuggler's Gulch) will be avoided during the vireo breeding season (March 15 to
August 31). If work is necessary to begin within 300 feet of suitable vireo habitat
during the breeding season, a biologist will conduct a preconstruction survey no more
than 14 days before construction initiation in the area to determine if any nesting
vireos are present. If an active nest is present, a 300-foot no-disturbance buffer
around the nest will be clearly demarcated, and the area will be avoided until the
young have fledged the nest and/or the nest becomes inactive. Preconstruction
surveys will be repeated if construction start is delayed more than 14 days from the
survey date.
Construction
~
~
~
©
©
©
©
5-9
-------
Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Mitigation Measure
Project Phase
Alternative 1
Alternative 2
ABCDEFGHI J
BR-24: (Special-status Species) To the greatest extent practicable, work within 300
feet of suitable gnatcatcher habitat (e.g., coastal sage scrub habitat associated with
Smuggler's Gulch) will be avoided during the gnatcatcher breeding season (February
15 to August 31). If work is necessary within 300 feet of suitable gnatcatcher habitat
during the breeding season, a biologist will conduct a preconstruction survey no more
than 14 days before construction initiation in the area to determine whether any
nesting gnatcatchers are present. If a nest is present, a 300-foot no-disturbance buffer
around the nest will be clearly demarcated, and the area will be avoided until the
young have fledged and/or the nest becomes inactive. Preconstruction surveys will be
repeated if construction start is delayed more than 14 days from the survey date.
Construction
©
©
©
©
BR-25: (Special-status Species) Additional conservation measures, if identified by
USFWS during ongoing informal consultation for the Core Projects, to ensure that
reductions in freshwater river flows will not result in a net loss of downstream riparian
habitat for the least Bell's vireo.
To Be
Determined
BR-26: (Special-status Plants and Sensitive Natural Communities) Protocol-level
surveys for special-status plant species and sensitive natural communities with the
potential to occur in the project areas will be conducted during appropriate blooming
periods and no less than one year prior to construction. The survey protocol will
follow the Guidelines for Conducting and Reporting Botanical Inventories for Federally
Listed, Proposed and Candidate Plants (USFWS 2000) and Protocols for Surveying and
Evaluating Impacts to Special Status Native Plant Populations and Sensitive Natural
Communities (CDFW 2018).
Planning
©
©
©
©
BR-27: (Special-status Plants and Sensitive Natural Communities) If found, a no-work
buffer will be established around the special-status plant population or sensitive
natural community, and this buffer will be avoided to the maximum extent
practicable. The buffer width will be determined in coordination with USFWS and/or
CDFW.
Planning,
Construction
©
©
©
©
BR-28: (Special-status Plants and Sensitive Natural Communities) If the special-status
plants or sensitive natural community cannot be avoided, a mitigation and monitoring
plan will be developed in coordination with USFWS and CDFW.
Planning,
Construction
©
©
©
©
5-10
-------
Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Mitigation Measure
Project Phase
Alternative 1
Alternative 2
A
B
C
D
E
F
G
H
1
J
BR-29: (Special-status Fish) Prior to commencing work, installation of silt fencing,
straw bales, fiber rolls, and/or other measures would be placed to reduce erosion and
sediment transport from construction areas and activities. Exposed soil areas will be
stabilized for overwintering protection from erosion.
Construction
~
~
~
©
©
©
©
BR-30: (Special-status Fish) Hydrocarbon contamination of aquatic habitats could
potentially occur during construction operations. Contamination could result from
leaking fuel or hydraulic lines on heavy equipment, improper fuel handling practices,
or spills during refueling or lubrication operations. The contractors will ensure that all
fuel and hydraulic lines on heavy equipment are in good working order and not
leaking. The operators will also conduct all fueling and lubrication operations at the
designated out-of-channel laydown site and use BMPs when doing so. There will be
no fuel storage facilities within the banks of the channel or within the floodplain. All
equipment will be serviced on an as-needed basis with the necessary fueling and
lubrication conducted at the designated locations. Accidents, such as a breaking of a
hydraulic line, require immediate cleanup of the area well before the onset of high-
flow conditions. Adequately sized spill kits will be present at all times during operation
of equipment. All packaging, containers, tires and auto body debris, other large metal
debris, and trash will be removed from the construction area and disposed of or
recycled properly.
Construction
~
~
~
©
©
©
©
BR-31: (Special-status Fish) In-water construction would be limited to the dry-season
(approximately June through November) unless otherwise agreed upon with resource
agencies. The intent of the established operating season is to limit the potential for
direct impacts and other interactions between construction activities and various
steelhead and Pacific lamprey life-history stages that occupy (seasonally or year-
round) the project site. If construction occurs during migration season,
implementation of trap and haul or other approaches to provide volitional or non-
volitional passage should be considered in coordination with resource agencies.
Construction
~
~
~
©
©
©
©
BR-32: (General) Additional unspecified measures, if necessary, to ensure wildlife and
fish impacts are not substantial (to be identified during subsequent tiered NEPA
analyses).
To Be
Determined
©
©
5-11
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Mitigation Measure
Project Phase
Alternative 1
Alternative 2
BCD
G H I J
BR-33: (General) A Field Environmental Monitor (FEM) will be onsite during ground-
disturbing activities and during construction to monitor compliance with applicable
environmental regulations and site-specific BMPs and conservation measures.
Construction
©
©
©
©
BR-34: (Marine Wildlife) Additional reasonable and prudent mitigation measures, if
identified by NMFS during ongoing formal consultation or in the Biological Opinion for
the Core Projects, to minimize potential effects to ESA-listed species due to SBOO
discharges.
To Be
Determined
BR-35: (Marine Wildlife) Vessel operator or crewmember must maintain a constant
watch of the ocean surface in front and adjacent to the vessel for marine mammals
and turtles at all times. If marine animals are observed distant to the vessel, vessel
operators should adjust their course as necessary to ensure they do not disturb the
natural behavior of these animals. If animals are observed within close limits of the
vessel such that the vessel may disturb those animals, vessels are advised to follow
close observation guidelines available through NMFS. These include the following
recommendations:
¦ Slow down and operate at a no-wake speed.
¦ Stay out of the path of the animal's direction of travel.
¦ Do not put your vessel between whales, especially mothers and calves.
¦ Do not chase or harass animals, and do not approach the animals head-on, from
directly behind them, or from the side (t-bone).
¦ If animals are following a trajectory closely parallel to the direction of vessel
travel, gradually steer the vessel to be parallel to the animals from the side and
stay at least 100 yards away—i.e., the length of a football field.
Construction
©
BR-36: (Marine Wildlife) If a vessel needs to deploy any anchors, the vessel operators
will check for reef with onboard sonar equipment and anchors will be deployed over
sandy seabed at least 10 feet away from the edge of the rocky reef surrounding the
SBOO.
Construction
©
5-12
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Mitigation Measure
Project Phase
Alternative 1
Alternative 2
A
B
C
D
E
F
G
H
1
J
BR-37: (Marine Wildlife) Vessels must be maintained to a standard that eliminates
the likelihood of diesel or hydraulic oil spills during normal operation, including the
storage and maintenance of spill kits appropriate to dealing with small vessel-based
spills such as sand buckets, absorbent pads and cloths, and other emergency
containment devices to stop small spills of hydraulic fluids and other polluting fluids
from entering the water if they are accidentally spilled on deck.
Construction
~
~
©
BR-38: (Marine Wildlife) In the case of a catastrophic loss of engine power that may
result in a grounding, vessel captains must have procedures in place to raise
coastguard support rapidly.
Construction
~
~
©
Geological Resources
GR-1: Preparation of a geotechnical report to assess site soil characteristics.
Planning
~
~
~
©
©
©
©
GR-2: Incorporation of site stabilization measures (e.g., revegetation of disturbed
areas) during and post-construction.
Construction
~
~
~
©
©
©
©
GR-3: Ripping and/or loosening of compacted areas prior to revegetation.
Construction
~
~
~
©
©
©
©
GR-4: Site watering to reduce fugitive dust from disturbed, exposed soils.
Construction
~
~
~
©
©
©
©
GR-5: Potential reuse of high-quality removed topsoil for restoration activities
elsewhere in the project area.
Construction
~
~
~
©
©
©
©
GR-6: Incorporation of standard erosion and sediment control BMPs, specified in a
project-specific Erosion and Sediment Control Plan and/or Stormwater Management
Plan (typical BMPs include silt fences, swales, and filter socks).
Planning,
Construction
~
~
~
©
©
©
©
GR-7: Incorporation of specific measures to reduce the potential for soil
contamination during construction (e.g., from equipment leaks or material spills) in a
project-specific SWPPP prepared by a certified Qualified SWPPP Developer and
approved by the San Diego Water Board.
Planning,
Construction
~
~
~
©
©
©
©
GR-8: Compliance with Uniform Building Code, California Building Code, City of San
Diego Municipal Code, and any applicable seismic design standards to ensure risks are
minimized and mitigated.
Planning,
Construction
~
~
~
©
©
©
©
GR-9: Incorporation of measures to prevent unstable soil conditions such as caving
and sloughing, especially during trenching operations.
Construction
~
~
©
©
©
5-13
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Alternative 1
Mitigation Measure
Project Phase
Alternative 2
A
B
C
D
E
F
G
H
1
J
Cultural Resources
CR-1: Avoidance of previously identified cultural resources during project design and
Planning,
construction. Should project plans change, and avoidance become infeasible, a formal
Construction
~
evaluation for eligibility to the NRHP is recommended.
Visual Resources
VR-1: Minimization of construction lighting, when practicable consistent with
applicable lighting regulations and ordinances.
Construction
~
~
~
©
©
©
©
*VR-2: Additional unspecified measures to reduce or mitigate potential detraction
To Be
from the visual character or quality of the localized area due to U.S.-side river
Determined
©
©
diversion and trash boom(s) (to be identified during subsequent tiered NEPA
analyses).
Land Use
[None identified]
Coastal Zone
[None identified (beyond those identified elsewhere in this table for resources in the coastal zone)]
Air Quality and Odor
*AQ-1: Community outreach to ensure that receptors potentially affected by odor
Planning,
emissions, including emissions from operation of the expanded UP (including the
Operation
anaerobic digester) and the new APTP, have the opportunity to share information
with USIBWC. Examples include but are not limited to:
¦ Continuing to hold USIBWC Citizens Forum Meetings as vehicle for hearing
community concerns.
¦ Publishing regular (e.g., annual) public notices to ensure community is aware of
¦
¦
©
meetings.
¦ Providing contact information to ensure timely communication of any odor
complaints.
¦ Conducting direct outreach to individual members of the potentially affected
community (e.g., via email or flyer) before the proposed facilities become
operational.
*AQ-2: Appropriate use of scrubbers, aeration, fugitive emissions containment
Planning,
©
system, and/or other odor controls to lessen odor impacts.
Operation
5-14
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Mitigation Measure
Project Phase
Alternative 1
Alternative 2
A
B
C
D
E
F
G
H
1
J
*AQ-3: Installation of BACT emissions reduction technologies for criteria pollutants
and/or HAPs (e.g., biogas pretreatment to remove formaldehyde and H2S, selective
catalytic reduction to remove NOx, catalytic oxidation to remove VOCs, combustion of
biogas).
Planning,
Operation
¦
*AQ-4: Development and implementation of a Fugitive Dust Control Plan to reduce
fugitive dust emissions and community exposure to fugitive dust. The plan would
apply to both active and inactive construction sites (i.e., including weekends and
holidays) and to related activities including hauling and storage of fill material. This
includes, but is not limited to, the following recommendations:
¦ Stabilizing of disturbed areas by covering and/or applying water or
chemical/organic dust palliative.
¦ Covering of hauled and stockpiled materials to prevent spillage or transport by
wind.
¦ Phasing of activities that produce substantial amounts of dust (e.g., grading
operations and dumping of soil) and avoiding these activities under windy
conditions.
¦ Limiting speed of earth-moving equipment to 10 mph.
¦ Placing stockpiles in locations away from nearby receptors.
Planning,
Construction
¦
¦
¦
©
©
©
©
5-15
-------
Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Mitigation Measure
Project Phase
Alternative 1
Alternative 2
A
B
C
D
E
F
G
H
1
J
*AQ-5: Inclusion of construction fleet emissions reduction strategies as a factor in the
scoring and evaluation of proposals during the procurement process. Examples
include, but are not limited to, indicating a preference for proposals that include
commitments to use the following:
¦ Energy-efficient and fuel-efficient fleets.
¦ Alternative fuel vehicles (e.g., electric, natural gas, biodiesel).
¦ Best available emissions control technology, including zero-emission technologies;
on-highway vehicles that meet or exceed EPA exhaust emissions standards for
model year 2010 and newer heavy-duty on-highway compression-ignition engines
(and/or more stringent upcoming regulations such as EPA's proposed "Clean
Trucks Plan"); and nonroad vehicles and equipment that meet or exceed EPA Tier
4 exhaust emissions standards for heavy-duty nonroad compression-ignition
engines.
¦ Add-on emission controls, where appropriate (e.g., diesel particulate filters).
¦ Grid-based electricity for generators.
Planning
¦
¦
¦
©
©
©
©
*AQ-6: Coordination with CDPR regarding construction and operation schedules to
ensure, to the extent practicable, that activities with potential to generate substantial
dust emissions at/near the ITP parcel and the Nelson Sloan quarry do not take place
concurrently (e.g., grading, fill, or sediment hauling activities at the ITP parcel taking
place concurrently with sediment hauling and deposition at the quarry).
Construction,
Operation
¦
¦
¦
©
©
©
©
*AQ-7: Procurement of a Program Management and Construction Management
Services team, whose responsibilities will include ensuring the construction contractor
takes appropriate measures to reduce air quality impacts. This includes, but is not
limited to, the following:
¦ Ensuring the construction contractor adheres to emissions reduction
commitments made during the procurement process (see AQ-5); adheres to the
Fugitive Dust Control Plan (see AQ-4) and Construction Traffic Management Plan
(see TR-3); limits idling of heavy equipment to less than five minutes; and locates
diesel engines, motors, and equipment staging areas as far as possible from
residential areas and other sensitive receptors.
¦ Conducting an equipment inventory (prior to groundbreaking) to identify
opportunities for use of add-on emission controls.
Planning,
Construction
¦
¦
¦
©
©
©
©
5-16
-------
Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Alternative 1
Mitigation Measure
Project Phase
Alternative 2
A
B
C
D
E
F
G
H
1
J
Climate
CL-1: Adherence to State of California GHG cap and trade program requirements, if
Planning
1
applicable.
CL-2: Incorporation of anaerobic digestion of primary and secondary sludge into
Planning,
project design (with appropriate control of biogas emissions) to reduce downstream
Operation
¦
GHG emissions from landfilling of solids waste from the expanded UP.
CL-3: Adherence to mitigation measures identified elsewhere in this table for
Planning,
reducing/offsetting anticipated increases in stationary and mobile source emissions,
Construction,
~
~
©
©
energy use, and waste generation.
Operation
Solid and Hazardous Waste
*SHW-1: Incorporation of anaerobic digestion of primary and secondary sludge into
Planning,
1
project design to reduce amount of solids waste from the expanded UP.
Operation
SHW-2: Development and implementation of a trash management plan for trash and
Planning,
©
debris captured by trash boom(s).
Operation
SHW-3: Development and implementation of a Solid and Hazardous Waste
Planning,
Management Plan that identifies wastes generated at the project site and their
Operation
~
~
~
©
©
©
©
appropriate means of disposal.
SHW-4: Implementation of employee training that outlines appropriate disposal
Planning,
practices for allowable wastes that can be placed in a landfill and regulated
Operation
~
~
~
©
©
©
©
substances including fluorescent light bulbs, oily rags, and aerosol cans.
Energy
EN-1: During siting, orientation, and design, encourage and explore ways to:
Planning
¦ Reduce wasteful, inefficient, and unnecessary consumption of energy during
construction, operation, maintenance and/or removal.
¦ Minimize energy consumption (including transportation energy), increase water
conservation, and reduce solid waste.
~
~
~
©
©
©
©
¦ Reduce peak energy demand.
¦ Employ alternate fuels (particularly renewable ones) or energy systems.
¦ Promote energy conservation, which could result from recycling efforts.
Public Services and Utilities
PSU-1: Incorporation of appropriate traffic control measures to ensure access to
Construction
~
~
~
©
©
©
©
community facilities is not impeded during construction.
5-17
-------
Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Mitigation Measure
Project Phase
Alternative 1
Alternative 2
A
B
C
D
E
F
G
H
1
J
PSU-2: Additional unspecified measures to reduce or mitigate potential impedance to
CBP operations due to U.S.-side river diversion and trash boom(s) (to be identified
during subsequent tiered NEPA analyses).
To Be
Determined
©
©
Public Health and Safety
*PHS-1: Additional unspecified measures to reduce or mitigate presence of standing
water in/around U.S.-side river diversion and intercepted trash (to be identified
during subsequent tiered NEPA analyses).
To Be
Determined
©
©
Transportation
*TR-1: Additional unspecified measures, if necessary, to ensure trash hauling does not
create substantial localized increases in traffic volumes in residential congestion (to be
identified during subsequent tiered NEPA analyses).
To Be
Determined
©
*TR-2: Incorporation of anaerobic digestion of primary and secondary sludge into
project design to reduce amount of solids waste requiring hauling from the expanded
UP.
Planning,
Operation
¦
*TR-3: Development and implementation of a Construction Traffic Management Plan
to include specific measures for reducing vehicle trips and VMT by the construction
vehicle fleet (in particular, reducing heavy truck trips in areas currently experiencing
extremely high overburdens from traffic impacts and/or traffic proximity).
Planning,
Construction
¦
¦
¦
©
©
©
©
*TR-4: Development and implementation of an Operational Traffic Management Plan
to include specific measures for reducing vehicle trips and VMT during treatment
plant operations and employee commuting (in particular, reducing heavy truck trips in
areas currently experiencing extremely high overburdens from traffic impacts and/or
traffic proximity).
Planning,
Operation
¦
¦
©
*TR-5: Feasibility assessment for the use of larger-capacity dump trucks for hauling of
APTP solids waste to landfills, thus reducing the number of trips required. This would
need to be conducted prior to or during design for the APTP to ensure the facilities
and site plan incorporate sufficient clearance for larger trucks.
Planning
¦
©
*TR-6: Local sourcing of fill material from within the Tijuana River Valley to limit haul
route distances, such as from the sediment deposits in Goat Canyon or Smuggler's
Gulch.
Planning,
Construction
¦
Noise
NO-1: Construction timing limited to Monday-Saturday from 7:00 a.m. to 7:00 p.m.
Construction
¦
¦
¦
©
©
©
©
5-18
-------
Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
Table 5-2. Summary of Mitigation Measures by Alternative and Project
Mitigation Measure
Project Phase
Alternative 1
Alternative 2
A
B
C
D
E
F
G
H
1
J
NO-2: Community outreach provide residents potentially affected by construction
noise from Project B, Option B1 trenching along Monument Road with information on
the benefits of the project, advanced notice of proposed construction dates and
times, and contact information to ensure timely communication of any noise
complaints.
Planning,
Construction
¦
NO-3: Construction timing for work within 300 feet of suitable least Bell's vireo or
coastal California gnatcatcher habitat limited to time-of-year restrictions outside of
bird breeding season (see Biological Resources Mitigation Measures #22 and #23
above).
Construction
¦
NO-4: Proper siting of biogas-fueled engine and electrical generator within the ITP
parcel (e.g., away from the property boundary) with incorporation of noise
attenuation features.
Planning,
Operation
¦
NO-5: Incorporation of design measures to minimize operational noise (i.e., acoustical
structure housing).
Planning,
Operation
~
~
~
©
©
©
Socioeconomics
SO-1: To the extent permitted by Federal statutes and regulations, USIBWC will
encourage the use of local small disadvantaged businesses or women-owned
businesses for Federal procurement(s) related to the proposed project.
Planning,
Construction,
Operation
~
~
~
©
©
©
©
Environmental Justice
[See mitigation measures identified with an asterisk (*) in Visual Resources, Air Quality and Odor,
Public Health and Safety, and Transportation sections above in this table.]
* Indicates a mitigation measure is necessary to address a disproportionately high and adverse effect identified in the environmental justice analysis (see
Section 4.20 [Environmental Justice]) or the environmental justice portion of the cumulative effects analysis (see Section 4.21.5 [Cumulative Effects]). In some
cases, this mitigation is necessary to address a disproportionately high and adverse effect caused by impacts in a different resource area—for example, SHW-1
under Solid and Hazardous Waste is intended to mitigate disproportionately high and adverse effects to air quality and transportation.
Symbol key:
¦ Core Projects: Mitigation measure is necessary to address a significant impact identified in Section 4 and Table 5-1.
Core Projects: Mitigation measure is intended to address both a non-significant impact and a disproportionately high and adverse effect identified in
the environmental justice analysis, as identified in Section 4 and Table 5-1.
~ Core Projects: Mitigation measure is intended to address a non-significant impact identified in Section 4.
© Supplemental Projects: Mitigation measure may be necessary to address impacts of a Supplemental Project. These potential impacts, their
significance, and the associated mitigation requirements will be analyzed further in subsequent tiered NEPA analyses.
5-19
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Mitigation Measures and Performance Monitoring
5.2 Mitigation Monitoring
Agencies may adopt monitoring programs, if applicable, to enforce mitigation requirements or
commitments, and if doing so, must summarize such monitoring in the decision document (e.g., the
ROD for an EIS) (40 CFR§ 1505.2). EPA and USIBWC will commit to the following roles and
responsibilities to ensure effective implementation of mitigation:
• EPA, as the agency responsible for coordinating the issuance of U.S. appropriations for
implementation of the Proposed Action, would ensure that any interagency agreements
with USIBWC regarding the Proposed Action include specification of the required mitigation
measures to be implemented, as identified in the ROD for the PEIS or in the decision
documents for subsequent tiered NEPA analyses.
• USIBWC, as the agency responsible for implementation of the Proposed Action, would
assume responsibilities for ensuring mitigation specified in the ROD is incorporated and
enforced. Mitigation measures would be incorporated into contract documents as
appropriate in the design and construction procurement process or otherwise implemented
by USIBWC. USIBWC oversight of this process would include, but not be limited to, review
and approval of designs, specifications, and Work Plans; monitoring of implemented
contracted mitigation activities and construction; review and approval of final reports,
assessments, and designs; and ensuring mitigation requirements are met.
5.3 Performance Monitoring of Project Effectiveness
EPA and USIBWC have identified the following mechanisms that would be used to monitor the
effectiveness of infrastructure improvements under the Proposed Action (i.e., performance
monitoring). This would include efforts to assess water quality, human health, and environmental
outcomes resulting from implementation of the Proposed Action. Additional opportunities for
performance monitoring may be identified at a later date or may be specified in the ROD.
• For projects that receive USMCA funds, USIBWC is planning pre- and post-implementation
monitoring events to document the resulting improvements in water quality. The specific
approach for the first phase of monitoring will be discussed as part of the Minute 320
Binational Core Group. Per a recent settlement agreement, USIBWC is also required to
perform quarterly assessments to evaluate the success of USMCA projects in addressing
impacts from sewage and other wastes in Mexico and the U.S. Funding for this monitoring
would be the responsibility of USIBWC.
• For projects that are funded through BWIP, grant agreements would terminate after one
year of operation and would include some monitoring to ensure the project is operating
correctly. The grant agreement would identify responsibilities for this monitoring.
• The RWQCB will require inclusion of a monitoring program in conjunction with reissuance
of the NPDES permit for the expanded ITP and the issuance of a NPDES permit for the new
APTP. This could potentially include ocean monitoring, industrial source monitoring,
and/or monitoring of Tijuana River and canyon flows. EPA and USIBWC would work with
the RWQCB through the NPDES permit process to establish the specific monitoring
requirements. Funding for this monitoring would be the responsibility of USIBWC.
5-20
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Compliance with Applicable Environmental Regulations
6. COMPLIANCE WITH APPLICABLE ENVIRONMENTAL REGULATIONS
6.1 United States Regulations and Permits
6.1.1 Summary of Federal Cross-Cutting Authorities
Table 6-1 summarizes the applicability of 22 federal overlapping ("cross-cutter") authorities to the
Proposed Action, based on the current understanding of the project scopes and impacts. For
presentation purposes, the cross-cutters are organized into three categories as described below:
1. Applicable Cross-Cutters with Major Requirements: Those that may require a substantial
effort on the part of the federal agency to reach full compliance or that have significant
resources present in the affected area that trigger compliance requirements.
2. Applicable Cross-Cutters with Minor Requirements: Those that may require minor effort on
the part of the federal agency to reach full compliance or that have minor resources present
in the affected area that trigger compliance requirements.
3. Non-Applicable Cross-Cutters: Those that do not apply and have no potential to be triggered
in the future.
The specific requirements of applicable cross-cutters are discussed throughout Section 4
(Environmental Consequences) and the following subsections of Section 6.1. Additionally, Section
7.2 (Regulatory Consultation) includes discussion of the consultation and coordination efforts
performed during the development of this PEIS in response to cross-cutter requirements.
6-1
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Compliance with Applicable Environmental Regulations
Table 6-1. Summary of Applicability of Federal Cross-cutting Authorities by Alternative and Project
Alternative 1
Federal Cross-cutting Authority
Alternative 2
A
B
c
D
E
F
G
H
1
J
Applicable Cross-Cutters with Major Requirements
Bald and Golden Eagle Protection Act (16 U.S.C. §§ 668-668C)
Clean Water Act: Section 401 (33 U.S.C. § 1341) and Section 404
*
V
V
(33 U.S.C. § 1344)
Clean Water Act: Section 402 National Pollutant Discharge
V
V
V
V
V
Elimination System (33 U.S.C. § 1342)
Coastal Zone Management Act (16 U.S.C. § 1451 et seq.)
V
V
V
V
V
V
V
Endangered Species Act (16 U.S.C. § 1531 et seq.)
V
V
V
V
V
V
V
EO No. 12898, Federal Actions to Address Environmental Justice in
V
V
V
V
V
V
V
Minority Populations and Low-Income Populations (59 FR 7629)
Fish and Wildlife Coordination Act (16 U.S.C. § 661 et seq.)
V
V
National Historic Preservation Act and Archeological and Historic
V
V
V
V
V
V
V
Preservation Act (16 U.S.C. § 469A-1)
Applicable Cross-Cutters with Minor Requirements
EO No. 11988, Flood Plain Management (42 FR 26951), as
•/
•/
•/
•/
amended by EO No. 12148, Federal Emergency Management (44
FR 43239)
Magnuson-Stevens Fishery Conservation and Management Act (16
V
V
V
V
V
U.S.C. § 1801 et seq.)
Marine Mammal Protection Act (16 U.S.C. § 1361)
V
V
V
V
V
Migratory Bird Treaty Act (16 U.S.C. §§ 703-712)
V
V
V
V
V
V
V
Native American Graves Protection and Repatriation Act (25 U.S.C.
V
V
V
V
V
V
V
§ 3001 et seq.)
EO No. 11990, Protection of Wetlands (42 FR 26961), as amended
V
V
V
by EO No. 12608, Elimination of Unnecessary Executive Orders and
Technical Amendments to Others (52 FR 34617)
Non-Applicable Cross-Cutters
Archaeological Resources Protection Act (16 U.S.C. §§ 470AA-MM)
Clean Air Act Conformity (42 U.S.C. § 7401 et seq.)
Coastal Barriers Resources Act (16 U.S.C. § 3501 et seq.)
Farmland Protection Policy Act (7 U.S.C. § 4201 et seq.)
Rivers and Harbors Act: Section 10 (33 U.S.C. § 403)
Safe Drinking Water Act (42 U.S.C. § 300f et seq.)
Wild and Scenic Rivers Act (16 U.S.C. § 1271 et seq.)
The Wilderness Act (16 U.S.C. § 1131 et seq.)
Symbol key:
S The project triggers the cross-cutter.
* The project potentially triggers the cross-cutter (applicability depends on final design and siting location).
6.1.2 Fresh water and Estuarine Resources
Surface Water: Lakes. Rivers, and Streams
Actions affecting surface water resources including lakes, rivers, and streams are regulated by the
federal CWA, specifically sections 401, 404, and 402. Section 401 of the CWA prohibits federal
agencies from issuing permits or licenses to conduct any activity that may result in any discharge
6-2
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Compliance with Applicable Environmental Regulations
into waters of the U.S. unless a state, in this case the San Diego Water Board, issues a water quality
certification. Section 404 of the CWA regulates the discharge of dredged or fill material into the
waters of the U.S. A Section 404 permit must be obtained from USACE before material maybe
discharged into "waters of the U.S.," which are broadly defined by USACE to include the navigable
waters, their tributaries, lakes, ponds, most impoundments of waters of the U.S., wetlands that are
adjacent to or abutting waters of the U.S, and the territorial seas. The federal CWA requires that
every applicant for a Section 404 permit or Section 10 of the Rivers and Harbors Act permit must
request a state certification that an activity does not violate state or federal water quality standards.
Section 402 of the CWA establishes the NPDES program, which regulates the discharge of pollutants
through a point source into a water of the U.S. The EPA establishes effluent limits for discharges and
sets water quality standards for constituents in surface waters. NPDES permits include limits on the
amounts of pollutants to be discharged, in addition to enforceable permit conditions related to
monitoring and reporting. In California, NPDES permits are managed by the RWQCBs. There are
two current NPDES permits for discharges to the Pacific Ocean via the SBOO: one for the SBWRP
(CA0109045) held by the City of San Diego and the other for the ITP (CA0108928) held by USIBWC.
See Section 3.2 (Marine Waters) for more details on these discharges.
Development activities affecting aquatic resources in California may require an LSA Agreement
CDFW requires that entities notify them prior to conducting activities that divert or obstruct river
flow; change the bed, channel, or bank of a river; use material from a river; or deposit or dispose of
material into a river. This regulation pertains to rivers that are dry for periods of time, such as the
Tijuana River, and includes riparian habitats associated with watercourses. CDFW requires an LSA
Agreement for any projects that may substantially adversely affect fish and wildlife resources
(CDFW, 2020b).
Surface Water Quality
The CWA is the most relevant federal policy pertaining to water quality in the Tijuana River. Section
303 requires states to adopt water quality standards, and Section 303(c)(2)(b) requires that states
adopt numerical water quality standards for toxic pollutants for which EPA has published water
quality criteria.
In California, the Porter-Cologne Act is the statutory authority for protecting water quality in
surface water, coastal waters, groundwater, and discharges. It requires California to adopt water
quality policies, plans, and objectives that protect the state's waters (SWRCB, 2014a). The Porter-
Cologne Act states that beneficial uses and water quality objectives must be defined for all waters of
the state (SDRWQCB, 2016). The RWQCB is responsible for designating appropriate beneficial uses
to be maintained and protected; the San Diego Water Board is responsible for carrying out these
obligations for the Tijuana River (SDRWQCB, 2016).
Wetlands
Wetlands in California are protected by federal and state laws, regulations, and policies. Under the
federal CWA, wetlands are defined as "Those areas that are inundated or saturated by surface or
ground water at a frequency or duration sufficient to support, and that normally do support, a
prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally
include marshes, swamps, bogs, and similar areas (33 CFR Part 328)." The overarching goal of the
CWA is to maintain the physical, chemical, and biological integrity of the Nation's waters, and more
specifically to ensure a "No Net Loss" of wetlands in the CWA regulatory program through
avoidance, then minimization, and finally compensatory mitigation for impacts associated with
6-3
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Final Programmatic EIS: USMCA Mitigation of
Contaminated Transboundary Flows Project
Compliance with Applicable Environmental Regulations
discharges of dredge or fill material into waters of the U.S. The Section 404 permit program allows
discharges of dredge of fill material into waters of the U.S., including wetlands, under two scenarios:
no practicable alternative exists that is less damaging to aquatic resources, or the waters of the U.S.
would not be significantly degraded. For unavoidable impacts on federally regulated wetlands,
compensatory mitigation is required to replace the loss of wetland and aquatic resource functions
in the watershed, as outlined in the Mitigation Rule Section 404(b)(1) guidelines. Wetlands under
CWA jurisdiction may occur within the Proposed Action area and would be subject to Section 404
regulations. Section 10 of the Rivers and Harbors Act prevents the unauthorized obstruction of
navigable waters of the U.S., including wetlands. The Tijuana Estuary (to 2.5 feet MSL) is regulated
as a Traditional Navigable Water (TNW) pursuantto Section 10 of the Rivers and Harbors Act;
however, the scope of this jurisdiction is outside of the Proposed Action area.
EO 11990, Protection of Wetlands (42 FR 26961), as amended (52 FR 34617), requires federal
agencies to avoid undertaking or providing assistance for new construction located in wetlands
unless practicable alternatives do not exist and the proposed action includes all practicable
measures to minimize harm to wetlands, which may result from such use. The affected area of the
Proposed Action includes mapped wetland features (see CWA discussion above). The federal
agency must consider alternatives to wetland sites and, if use of a wetland site cannot be avoided,
must minimize damage to wetlands. EO 11990 is applicable to Projects F and J and is potentially
applicable to Project B, depending on final designs. Alternatives are being evaluated as part of this
NEPA review and, through coordination with the appropriate entities, mitigation, minimization, and
avoidance measures will be incorporated into the decision-making process.
The CZMA authorizes states to manage coastal resources, which in California are administered by
state agencies, including CCC, under the CCMP (see Section 6.1.9 [Coastal Zone] for additional
information). The CCC is responsible for determining the presence of wetlands that are subject to
regulation under the CCA; further, the CCC may review applications for Section 404 and Section 10
permits for consistency with the CCMP in addition to other requirements the CCC has for CDP
applications. Section 30231 of the CCA requires the maintenance and restoration of the biological
productivity and quality of wetlands. Section 30233 prohibits the filling of wetlands unless there is
no feasible alternative that is less environmentally damaging. A portion of the coastal wetlands
within the Tijuana River Valley likely fall within the jurisdiction of the CCC and are subject to CCC
regulations.
In accordance with the Porter-Cologne Water Quality Control Act, the RWQCBs regulate discharges
of dredge and fill material that may affect the quality of waters of the state, including some but not
all features that are defined as wetlands. The state's wetland definition generally includes all waters
of the U.S. and all natural wetlands regardless of their proximity to other waters. Project activities
resulting in discharges of dredged and fill material into wetland waters of the state may be
reviewed under the RWQCB's Waste Discharge Permitprogram (SWRCB, 2021).
The CDFW assists the CCC with determining the size and presence of wetlands subject to regulation
under the CCA. Wetlands may also be subject to jurisdiction by CDFW under Sections 1600-1616 of
the California Fish and Game Code.
Activities associated with the construction of one Core Project (Project B, Option Bl), depending on
final design and siting location of the pipeline, would potentially require a Section 404 Nationwide
Permit 58 for Utility Line Activities for Water and Other Substances and may be eligible for
enrollment under a RWQCB General Order to meet Section 401 Water Quality Certification and
Waste Discharge Requirements. Depending on final design and siting location, the activities may
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also require an LSA Agreement with the CDFW, and/or a CDP from the CCC. For Supplemental
Projects, the specific construction-related impacts to aquatic resources and the associated
permitting and review requirements (e.g., CWA Section 404 permit authorization, RWQCB 401
Water Quality Certification, LSA Agreement, CDP) would be evaluated in subsequent tiered NEPA
analyses.
Stormwater Management
Stormwater discharges are regulated under the CWA Section 402 NPDES program. In addition, EISA
requires federal agencies to reduce stormwater runoff from federal development and
redevelopment projects to protect water resources, which can include green infrastructure and
low-impact development practices. EO 13834, Efficient Federal Operations (83 FR 23771), stipulates
that agencies must meet statutory requirements pertaining to stormwater management, and notes
that Section 438 of EISA establishes those requirements for construction of new federal facilities
(CEQ, 2019; EPA, 2018).
In California, the SWRCB is responsible for issuing stormwater permits in accordance with the
NPDES program. If more than one acre of land will be disturbed, the entity conducting the
construction must file an NOI to be covered under the General Permit for Storm Water Discharges
Associated with Construction Activity (General Permit Order 2009-0009-DWQ) (SWRCB, 2013).
The General Permit requires that entities must also have a SWPPP prepared by a certified Qualified
SWPPP Developer that specifies BMPs that will be used to prevent pollutants from entering
stormwater and to control sediment erosion (SWRCB, 2013). Stormwater discharge from industrial
sites is allowed through an Industrial General Permit (State Board Order 2014-0057-DWA), and
discharge from construction sites requires a Construction General Permit (State Board Order 2012-
0006-DWQ) (SWRCB, 2012, 2014b). The San Diego Water Board issues stormwater permits for
projects in the Tijuana River Valley and reviews SWPPPs and activities in accordance with a general
NPDES permit.
At the county level, stormwater is regulated under the County of San Diego Watershed Protection,
Stormwater Management, and Discharge Control Ordinance. Under this ordinance, entities
undertaking development projects in the County of San Diego must adhere to discharge regulations,
which may include BMPs, and create a Stormwater Management Plan that describes measures that
will be used for stormwater and non-stormwater management (County of San Diego, 2016).
Additionally, permanent, post-construction stormwater management must be consistent with
applicable requirements of the County of San Diego Watershed Protection, Stormwater
Management, and Discharge Control Ordinance and with the Regional MS4 permit (NPDES No.
CAS0109266), and compliance guidance provided by the County of San Diego BMP Design Manual
(County of San Diego, 2020c). Of the Core Projects, Projects A and D would be required to
incorporate design measures to reduce post-construction runoff per the County of San Diego BMP
Design Manual (under which both projects are likely to be considered Priority Development
Projects) and per EISA. Under the MS4 permit and the county's Watershed Protection, Stormwater
Management, and Discharge Control Ordinance Section 67.811(b)(4)(A), projects must implement
BMPs designed to retain onsite the pollutants contained in the volume of stormwater runoff
produced from a 24-hour 85th percentile storm event that would occur when the project is
complete. A Stormwater Quality Management Plan, which documents the stormwater management
design for each project, would need to be submitted to the county, and county approval would be
required as part of the Regional MS4 Permit (NPDES No. CAS0109266). The county review process
ensures that stormwater management objectives were considered during project planning and that
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potential permanent BMPs have been identified. Both projects would likely require a General
Permit for Stormwater Discharges Associated with Construction Activity. Of the Supplemental
Projects, Projects E, F, and J may also face the same requirements, but the specifics of such
applicability would be evaluated in subsequent tiered NEPA analyses.
Groundwater and Drinking Water
The Safe Drinking Water Act (SDWA) authorizes the EPA to set health-based standards for drinking
water. In addition, SDWA authorizes EPA to designate sole source aquifers and review projects
located in the review area for the aquifer to ensure that the project does not contaminate the sole
source aquifer.
The SDWA does not apply to the Proposed Action because no sole source aquifers exist within the
affected area and none of the projects involve establishing public drinking water systems.
6.1.3 Marine Waters
Section 402 of the CWA establishes the NPDES program, which regulates the discharge of pollutants
through a point source into a water of the U.S. A NPDES permit is required for such discharges and
would contain limits on the amounts of pollutants to be discharged in addition to enforceable
permit conditions related to monitoring and reporting. In California, the state is fully authorized to
issue NPDES permits through its state NPDES program managed by the SWRCB and the RWQCBs.
Discharges to ocean waters must further comply with Ocean Discharge Criteria when obtaining a
NPDES permit pursuant to Section 403 of the CWA.
Limits on discharges to marine receiving waters are also informed by the NRWQC. Published
pursuant to Section 304(a) of the CWA, the NRWQCs are compiled to provide guidance for states
and tribes to establish water quality standards and control discharges. Some pollutants have
NRWQCs established for the protection of aquatic life that establish the acute (i.e., criteria
maximum) or chronic (i.e., criteria continuous) concentrations in saltwater (EPA, 2020).
The California Ocean Plan is intended to protect the quality of ocean waters for public use and
enjoyment, by means of controlling discharge of waste to ocean waters and intake of seawater. The
California Ocean Plan therefore regulates discharges to the ocean from point source discharges
such as the SBOO (SWRCB, 2019). The California Ocean Plan identifies water quality objectives,
which include standards for bacterial, physical, chemical, and biological characteristics, as well as
radioactivity. It also provides water quality objectives for protection of marine aquatic life (based
on six-month median, daily maximum, and instantaneous maximum limiting concentrations) and
protection of human health from carcinogens and non-carcinogens (based on 30-day average
limiting concentrations).
Section 402 of the CWA is applicable to all projects that would increase discharges via the SBOO.
Core Projects A (Expanded ITP) and D (APTP Phase 1) and Supplemental Project E (APTP Phase 2)
would be expected to meet discharge requirements and obtain NPDES permits. This process would
need to account for any projected changes in the influent wastewater resulting from
implementation of Core Projects B (Tijuana Canyon Flows to ITP) and C (Tijuana Sewer Repairs)
and Supplemental Project H (Tijuana WWTP Treated Effluent Reuse). For Supplemental Projects,
the subsequent tiered NEPA analyses for these projects would evaluate the specific estimated
changes in loadings and marine water quality impacts resulting from these increases in SBOO
discharges.
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These projects would ensure consistency with the California Ocean Plan via the NPDES process. As
part of the NPDES application, EPA/USIBWC would complete and submit effluent testing data and
whole effluent toxicity testing data consistent with EPA's NPDES application form requirements. In
addition, EPA/USIBWC would submit a request to the San Diego Water Board for a regulatory
mixing zone based on modeling that reflects the facility's operational and discharge characteristics
at the time of application. When fully treated and with the establishment of a regulatory mixing
zone, the discharge from the facility would not cause or contribute to exceedances of water quality
objectives of the California Ocean Plan.
6.1.4 Floodplains
Section 14 of the Rivers and Harbors Act, commonly referred to as Section 408 (of the U.S.C.),
provides that any use or alteration of a civil works project by another party is subject to the
approval of USACE. The Tijuana River Basin (Tijuana River Flood Control Project) was completed in
1979 and is controlled by USIBWC. While USACE designed and provided construction management
services for the Tijuana River Flood Control Project, they performed work under contract to
USIBWC rather than through USACE funding. The Tijuana River Basin is owned and managed by
USIBWC and is therefore not a civil works project. Thus, modification to the basin under the
Proposed Action does not require a Section 408 permit or USACE approval.
EO 11988, Floodplain Management (42 FR 26951), as amended (44 FR 43239), requires federal
agencies to evaluate the potential effects of any actions it may take in a floodplain and is
implemented by the Guidelines for Implementing Executive Order 11988, Floodplain Management,
and Executive Order 13690, Establishing a Federal Flood Risk Management Standard and a Process
for Further Soliciting and Considering Stakeholder (FEMA, 2015). EO 11988 requires that an agency
consider alternatives to avoid adverse effects and incompatible development in a floodplain. In
addition, the EO requires public notice for actions that are proposed to be located in the floodplain
and requires that new construction in a floodplain be protected with floodproofing or other
measures. The implementing guidance recommends that the floodplain be defined and established
through one of several approaches. For purposes of this Proposed Action, where a levee structure
exists to provide freeboard elevation around critical infrastructure (the ITP), the floodplain
considered is defined as "the elevation and flood hazard area that result from using the freeboard
value, reached by adding an additional 2 feet to the base flood elevation (BFE) for non-critical
actions and from adding an additional 3 feet to the BFE for critical actions" (FEMA, 2015). The levee
system that surrounds the Tijuana River Basin provides 3 feet of freeboard above the BFE and is
designed to protect the ITP parcel from a 333-year flood event at the south levee specifically.
Projects located within the levee system are subject to the requirements of EO 11988.
Development in a floodplain or floodway is also regulated by county requirements. The San Diego
County General Plan—Safety Element establishes policies related to flood hazards and development
within floodways, such as limiting development in floodplains and requiring conformance to federal
floodproofing standards and siting criteria (County of San Diego, 2011). Furthermore, the County of
San Diego Flood Damage Prevention Ordinance imposes construction standards on projects located
in SFHAs to protect human life and to minimize public and private losses due to flood conditions.
The ordinance requires a development permit for new construction and requires notifications from
the Floodplain Administrator to adjacent communities, the California Department of Water
Resources, and FEMA for alteration or relocation of a watercourse in a FEMA floodplain.
Construction in a floodway requires a "No Rise" Certification demonstrating the proposed use shall
not result in any increase in flood levels during the base flood discharge (San Diego County Code of
Regulatory Ordinances, Title 8, Division 11).
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As discussed in Section 4.3 (Floodplains), the majority of the Proposed Action is located outside the
100-year floodplain and the regulatory floodway. However, Projects F (U.S.-side River Diversion to
APTP) and J (Trash Boom[s]), and a small component of Project B (Options B1 andB2 only), would
occur within the 100-year floodplain (a SFHA). Additionally, Projects F and J would occur within the
levee system and in the regulatory floodplain and therefore would be required to comply with EO
11988 and the Flood Damage Prevention Ordinance. For those projects subject to the EO, this PEIS
includes an initial consideration of alternatives to development in the floodplain (i.e., the No-Action
Alternative). However, subsequent tiered NEPA analyses for Projects F and J would need to address
the requirements of EO 11988 in more detail and would provide the required public notices.
6.1.5 Inland Biological Resources
Endangered Species Act
Under ESA Section 7, federal agencies must consult with the USFWS when any action the agency
carries out, funds, or authorizes may affect a listed endangered or threatened species under USFWS
jurisdiction. A federal agency must ensure that its actions are not likely to jeopardize the continued
existence of endangered or threatened species, or adversely modify or destroy their designated
critical habitat Furthermore, if incidental take is reasonably certain to occur, ESA requires USFWS
to provide an Incidental Take Statement that specifies the impact of any incidental taking and
includes nondiscretionary, reasonable, and prudent measures and terms and conditions to
minimize such impacts.
If the federal agency taking the action determines that the project is not likely to adversely affect
listed species and/or critical habitat, they submit an informal consultation request to USFWS for
concurrence. USFWS will provide a Letter of Concurrence to the EPA if it agrees with the action
agency's not likely to adversely affect determination.
ESA Section 7 is applicable to all Core Projects with effects in the U.S. Several federally listed
endangered or threatened species have potential to occur in the area affected by the Proposed
Action. Consultation with USFWS is therefore necessary to determine the potential for adverse
effects on listed species that may occur. See Section 7.2.1 (Endangered Species Act Section 7
Consultation) regarding this consultation with USFWS.
Similarly, ESA Section 7 is applicable to Supplemental Projects E, F, I and J. Consultation would take
place during subsequent tiered NEPA analyses.
Migratory Bird Treaty Act
The Migratory Bird Treaty Act (MBTA) makes it unlawful to take any protected migratory bird
species listed in 50 CFR§ 10.13 without prior authorization by USFWS. Because protected
migratory birds use the affected area, compliance with the MBTA is required.
Migratory birds are abundant and can be found in the majority of habitat types across the U.S. In the
lower Tijuana River Valley, especially in the estuary and along the coastline, migratory birds are
attracted to the marsh and wetland habitats. The USFWS Information for Planning and Consultation
tool identifies 28 migratory bird species with the potential to occur in the Tijuana River Valley, plus
additional species that could occur along the beaches north of the estuary. Avian species, the
majority of which are protected under the MBTA, are listed in Section 3.4.2 (Wildlife and Inland
Fish Resources).
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Typically, construction and operation of wastewater infrastructure has the potential to result in
indirect impacts to protected migratory bird species. The MBTA is applicable to all Core and
Supplemental Projects located in the U.S. (i.e., Projects A, B, D, E, F, I, and J). General wildlife-related
mitigation measures included in Section 5 (Mitigation Measures and Performance Monitoring)
would help mitigate impacts to migratory birds. EPA and USIBWC received no recommendations
specific to migratory birds during the comment review period. Mitigation measures, once adopted
in the NEPA decision document, become enforceable by the EPA.
Bald and Golden Eagle Protection Act
BGEPA provides for the protection of the bald eagle and the golden eagle by prohibiting, except
under certain specified conditions, the taking, possession and commerce of such birds. The BGEPA
broadly defines 'take' as "pursue, shoot, shoot at, poison, wound, kill, capture, trap, collect, molest,
or disturb."
As documented in Section 3.4.2 (Wildlife and Inland Fish Resources), bald eagles and golden eagles
are expected to have a low likelihood to occur within the project areas due to the lack of suitable
nesting habitat and presence of only marginally suitable foraging habitat While the BGEPA would
apply, the Proposed Action would have minimal or no potential to result in the take of individuals of
either species. Consultation and coordination with USFWS has not identified any further
requirements for complying with the BGEPA.
Fish and Wildlife Coordination Act
The Fish and Wildlife Coordination Act (FWCA) requires consultation with the USFWS and the fish
and wildlife agencies of states where the "waters of any stream or other body of water are proposed
or authorized to be impounded, diverted, the channel deepened, or the stream or other body of
water otherwise controlled or modified for any purpose whatever, including navigation and
drainage" by any agency under a federal permit or license. An exemption exists for surface water
impoundments where the maximum surface area is less than 10 acres.
FWCA is applicable to the Supplemental Projects with major activities in the Tijuana River—
specifically, Projects F (U.S.-side River Diversion to APTP) and J (Trash Boom[s])—and therefore
USFWS review is required. To date, USFWS has not provided any comments related to FWCA
compliance. FWCA recommendations, if applicable, would be expected to be provided by USFWS
during subsequent tiered NEPA analyses and would be considered as mitigation in the tiered NEPA
process.
California Endangered Species Act
CESA conserves and protects species at a risk of extinction, with species being designated as
threatened or endangered by the California Fish and Game Commission. A CESA-listed species may
not be imported, exported, taken, possessed, purchased, or sold without proper authorization from
the CDFW. CESA is similar to the federal ESA both in process and substance; it is intended to
provide additional protection to threatened and endangered species in California. Species may be
listed as threatened or endangered under both acts (in which case the provisions of both state and
federal laws apply) or under only one act A candidate species is one that the California Fish and
Game Commission has formally noticed as being under review by CDFW for addition to the state
list. Candidate species are protected by the provisions of CESA. Any listed or candidate species that
could be adversely affected by any aspect of the proposed project would be required to comply with
CESA and obtain an incidental take permit.
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As described in Section 3.4 (Inland Biological Resources), there are CESA-listed species present that
would be affected by the Proposed Action. Therefore, CESA would apply to the Proposed Action. As
described in Section 4.4 (Inland Biological Resources), USIBWC would coordinate with CDFW if new
information (e.g., protocol-level or preconstruction surveys) reveals that the Proposed Action
would potentially result in take of state-listed species protected under CESA.
California Fish and Game Code
The CDFW is also responsible for enforcing the California Fish and Game Code, which contains
several provisions potentially relevant to construction projects. The Fish and Game Code lists
animal species designated as Fully Protected, which may not be taken or possessed at any time. The
Fully Protected designation does not allow "incidental take" and is thus more restrictive than CESA.
Fully Protected species are listed in Sections 3511 (birds), 4700 (mammals), 5050 (reptiles and
amphibians), and 5515 (fish) of the Fish and Game Code, while protected amphibians and reptiles
are listed in Chapter 5, Sections 41 and 42 (California Code of Regulations [CCR]; Title 14, Div. 1).
Section 3503 of the Fish and Game Code (CCR; Title 14, Div. 1) prohibits the take, possession, or
needless destruction of the nest or eggs of most bird species. Subsection 3503.5 (CCR; Title 14, Div.
1) specifically prohibits the take, possession, or destruction of any birds in the orders
Falconiformes (hawks and eagles) or Strigiformes (owls) and their nests. These provisions, along
with the federal MBTA, serve to protect nesting native birds. Certain non-native species, including
European starling and house sparrow, are not protected under the California Fish and Game Code.
All Core and Supplemental Projects would comply with the Fish and Game Code by avoiding
incidental take of any Fully Protected species, and the mitigation measures discussed in Section 5
(Mitigation Measures and Performance Monitoring) would help ensure compliance. Mitigation
measures include conducting preconstruction protocol-level surveys for special-status species
(Mitigation Measure BR-2 6) and establishing a no-work buffer to avoid take, if necessary and
feasible (Mitigation Measure BR-27).
California Species of Special Concern
The CDFW maintains an administrative list of Species of Special Concern, defined as a "species,
subspecies, or distinct population of an animal native to California that currently satisfies one or
more of the following (not necessarily mutually exclusive) criteria: is extirpated from the State, or,
in the case of birds, in its primary seasonal or breeding role; is listed as federally, but not State,
threatened or endangered; meets the State definition of threatened or endangered but has not
formally been listed; is experiencing, or formerly experienced, serious (noncyclical) population
declines or range retractions (not reversed) that, if continued or resumed, could qualify it for State
threatened or endangered status; and has naturally small populations exhibiting high susceptibility
to risk from any factor(s), that if realized, could lead to declines that would qualify it for State
threatened or endangered status."
The CDFW's Nongame Wildlife Program is responsible for producing and updating Species of
Special Concern publications for mammals, birds, reptiles, and amphibians. The Fisheries Branch is
responsible for updates to the Fish Species of Special Concern document and list. Section 15380 of
the CEQA Guidelines indicates that Species of Special Concern should be included in an analysis of
project impacts if they can be shown to meet the criteria of sensitivity outlined therein. In contrast
to species listed under the federal or California ESAs, however, Species of Special Concern have no
formal legal protective status.
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Native Plant Protection Act
The Native Plant Protection Act (NPPA; CFG Code Section 1900 et seq.) designates 64 species,
subspecies, and varieties of native California plants as rare. NPPA prohibits take of rare native
plants but includes some exceptions for agricultural and nursery operations; emergencies; and,
after properly notifying CDFW, for vegetation removal from canals, roads, and other sites, changes
in land use, and in certain other situations. All Core and Supplemental Projects in California would
comply with the NPPA by avoiding take of rare native plants, and the mitigation measures
discussed in Section 5 (Mitigation Measures and Performance Monitoring) would help ensure
compliance. Mitigation measures include conducting preconstruction protocol-level surveys for
special-status species (Mitigation Measure BR-26); establishing a no-work buffer to avoid take, if
necessary and feasible (Mitigation Measure BR-27); and developing a mitigation and monitoring
plan in coordination with CDFW, if necessary (Mitigation Measure BR-28).
California Rare Plant Ranks
Special-status plants in California are assigned to one of five CRPRs by a group of over 300 botanists
in government, academia, non-governmental organizations, and the private sector. This effort is
jointly managed by the CDFW and CNPS. The five CRPRs currently recognized by the CNDDB
include the following:
• Rare Plant Rank 1A—presumed extinct in California.
• Rare Plant Rank IB—rare, threatened, or endangered in California and elsewhere.
• Rare Plant Rank 2—rare, threatened, or endangered in California but more common
elsewhere.
• Rare Plant Rank 3—a review list of plants about which more information is needed.
• Rare Plant Rank 4—a watch list of plants of limited distribution.
Substantial impacts to plants ranked 1A, IB, and 2 are typically considered significant based on
Section 15380 of the CEQA Guidelines, depending on the policy of the lead agency. Plants ranked 3
and 4 may be evaluated by the lead agency on a case-by-case basis to determine significance
thresholds under CEQA.
6.1.6 Marine Biological Resources
Endangered Species Act
Under ESA Section 7, federal agencies must consult with NMFS when any action the agency carries
out, funds, or authorizes may affect a listed endangered or threatened species under NMFS
jurisdiction. A federal agency must ensure that its actions are not likely to jeopardize the continued
existence of endangered or threatened species, or adversely modify or destroy their designated
critical habitat If the federal agency concludes that the proposed federal action is likely to
adversely affect listed species, the federal agency must request formal consultation pursuant to 50
CFR § 402.14 under the ESA. NMFS will then consider the findings of the Biological Assessment and
prepare a Biological Opinion stating how the agency's actions would affect listed species in
accordance with Section 7(b)(3) of the ESA. The Biological Opinion will consider whether the
proposed federal action has the potential to jeopardize the continued existence of endangered or
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threatened species in accordance with Section 7(a)(2). If incidental take is reasonably certain to
occur, Section 7(b)(4) requires NMFS to provide an Incidental Take Statement that specifies the
impact of any incidental taking and includes nondiscretionary reasonable and prudent measures
and terms and conditions to minimize such impacts.
ESA Section 7 is applicable to projects that would increase the amount of pollutants discharged into
the ocean via the SBOO, including all of the Core Projects. It is also applicable to projects that would
require physical modifications to the SBOO (e.g., Projects A, D, and/or E). As described in Section
3.5 (Marine Biological Resources), while no marine critical habitats occur at or near the SBOO,
several federally listed endangered or threatened species have potential to occur in the marine
environment around the SBOO. Consultation with NMFS is therefore necessary to determine the
potential for adverse effects on listed marine species that may occur. See Section 7.2.1 (Endangered
Species Act Section 7 Consultation) regarding this consultation with NMFS.
Marine Mammal Protection Act
The MMPA restricts the take71 of marine mammals and is implemented by NMFS, USFWS, and the
Marine Mammal Commission. The act provides for both directed and incidental take authorizations
that may permit an entity to incidentally take marine mammals associated with commercial and
noncommercial fishing operations, for scientific purposes, and for other limited activities. All
marine mammals are protected under the MMPA.
The MMPA is applicable to projects that would increase the amount of pollutants discharged into
the ocean via the SBOO, including all of the Core Projects. It is also applicable to projects that would
require physical modifications to the SBOO (e.g., Projects A, D, and/or E). As described in Section
3.5 (Marine Biological Resources), protected marine mammals have the potential to occur in the
marine environment around the SBOO, and an increase in discharges via the SBOO has the potential
to result in indirect impacts to these protected marine mammals. If project activities may result in
exceeding Level A or Level B harassment thresholds,72 there are two types of authorizations that
can be obtained depending on the project activity:
• An Incidental Harassment Authorization—written approval from NMFS for time-limited
harassment, which is generally applied to activities like construction that might occur over
a period typically shorter than a year or two.
• A Letter of Authorization—for operational effects that may span multiple years.
71 Take is defined to mean "to harass, hunt, capture, or kill, or attempt to harass, hunt, capture, or kill any
marine mammal" (16 U.S.C. § 1362). This definition is expanded in 50 CFR § 216.3 to include a list of actions
that fall into the category of take.
72 Level A harassment means the potential to injure a marine mammal or marine mammal stock in the wild.
Level B harassment means the potential to disturb a marine mammal or marine mammal stock in the wild by
causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing,
breeding, feeding, or sheltering but which does not have the potential to injure a marine mammal or marine
mammal stock in the wild.
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The Proposed Action is likely to result in net benefits to marine mammals protected under the
MMPA. Therefore, there is no likelihood of incidental take and no requirement for application to
NMFS under the MMPA for an incidental take authorization of letter of authorization.
Magnuson-Stevens Fishery Conservation and Management (Magnuson-Stevens) Act
The Magnuson-Stevens Act governs fisheries management in U.S. federal waters and requires
federal agencies to consult with NMFS regarding any action authorized, funded, or undertaken, or
proposed to be authorized, funded, or undertaken, that may adversely affect EFH. Within the
category of EFH, regional Fishery Management Councils are entitled to identify HAPCs. These
subsets of EFH are either spatially explicit areas or habitat types that have been identified by
regional Fishery Management Councils as having high priority for conservation, management, or
research.
The Magnuson-Stevens Act is applicable to projects that would increase the amount of pollutants
discharged into the ocean via the SBOO, including all of the Core Projects. It is also applicable to
projects that would require physical modifications to the SBOO (e.g., Projects A, D, and/or E). As
described in Section 3.5 (Marine Biological Resources), the marine environment around the SBOO
includes several EFH-designated areas, including those of the common thresher shark, dorado fish,
PCG, CPS, and krill, as well as HAPCs including canopy kelp and rocky reefs. In addition, estuaries
are designated as HAPCs, and potential changes in river flows, canyon flows, and sediment
transport to the Tijuana River Estuary would therefore require consideration for potential adverse
effects on CPS EFH and PCG HAPC. See Section 7.2.2 (Magnuson-Stevens Fishery Conservation and
Management Act Consultation (Essential Fish Habitat)) regarding this consultation with NMFS.
California Endangered Species Act
CESA conserves and protects species at a risk of extinction, with species being designated as
threatened or endangered by the California Fish and Game Commission (CDFW, 2021c). A CESA-
listed species may not be imported, exported, taken, possessed, purchased, or sold without proper
authorization from the CDFW (CDFW, 2 02 Id). CDFW designates Species of Special Concern, which
carries no formal legal status but allows focus on native California wildlife species at conservation
risk before they meet CESA criteria for listing (CDFW, 2021b). The CEQA Guidelines indicate that
Species of Special Concern should be included in an analysis of project impacts if they can be shown
to meet the criteria of sensitivity outlined therein (Cal. Code Regs. tit. 14, § 15380). CDFW Fully
Protected animals may not be taken or possessed, and no permits may be issued except for
scientific research or relocation (CDFW, 2021a)
There are no affected CESA-listed species in the marine environment Therefore, CESA regulating
marine wildlife would not apply to the Proposed Action.
6.1.7 Cultural Resources
National Historic Preservation Act
To ensure the protection of historic resources, the U.S. Congress passed the NHPA in 1966 and then
amended the NHPA in 1976,1980,1992, and 2016. Section 106 of the NHPA, implemented under
36 CFR Part 800, requires federal agencies to consider the effects of undertakings (i.e., actions) on
any historic property and consult with various parties, including the SHPO, on these effects. The
goal of consultation is to identify historic properties potentially affected by the undertaking, assess
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the effects on those properties, and identify ways to avoid, minimize, or mitigate any adverse effects
on historic properties. In California, the OHP within the CDPR serves as the SHPO.
The use of federal funds administered by EPA for the Proposed Action qualifies as an undertaking
for purposes of the NHPA as defined in 36 CFR § 800.16. Sections 7.2.3 and 7.2.4 discuss EPA's
consultations with OHP and Native American tribes.
Native American Graves Protection and Repatriation Act
The Native American Graves Protection and Repatriation Act (NAGPRA) (Pub. L. No. 101; 43 C.F.R. §
10.4) requires the preparation of an inadvertent discoveries plan for excavation to ensure that
certain Native American human remains, funerary objects, sacred objects, and objects of cultural
patrimony are appropriately repatriated if found.
The significant majority of excavation activities associated with the Proposed Action in the U.S.
would take place within federal lands (e.g., Projects A, D, E, F, I, and J). If remains or cultural items
are discovered on federal or tribal lands, federal agencies may pursue intentional excavation or
removal pursuant to a previously developed discovery plan. However, if the likelihood of discovery
is deemed low, the federal agency may forgo developing a formal plan and instead include plans for
addressing inadvertent discoveries in some other manner, such as in their Section 106 compliance
documentation. Inadvertent discoveries are typically handled by issuing a stop work order,
protecting the site from damage, and then following up with the appropriate entities to consult and
develop a plan for disposition so that work can resume. Preparation of an inadvertent discoveries
plan is expected to be sufficient to ensure NAGPRA compliance.
Some excavation or trenching activities associated with the Proposed Action in the U.S. would take
place outside of federal or tribal lands, including potential excavation within Smuggler's Gulch and
along Monument Road under Project B (Tijuana Canyon Flows to ITP). Local or state laws would
govern excavations and discoveries in these areas (e.g., California PRC § 5097.98 and State Health
and Safety Code § 7050.5) and would not be subject to NAGPRA; however, under state laws, a
similar mechanism exists for the discussion and repatriation of culturally sensitive materials.
Archaeological Resources Protection Act
The Archaeological Resources Protection Act (ARPA) (Pub. L. No. 96-95; 16 U.S.C. 470cc(a))
establishes requirements for projects involving the excavation or removal of archeological
resources on public lands (i.e., lands owned and administered by the U.S.) or Indian lands. Any
entity undertaking a project on public or Indian lands must obtain a permit for the excavation or
removal of archaeological resources and for carrying out any associated activities.
The majority of activities associated with the Proposed Action in the U.S. would take place within
federal lands. However, none of the Core Projects or Supplemental Projects are expected to involve
excavation or removal of archaeological resources. The potential for inadvertent discoveries and
methods to avoid unintentional excavation or removal of archaeological resources are identified
during the NHPA Section 106 process.
The affected area does not include American Indian tribal lands or those associated with federally
recognized tribal entities (e.g., federally recognized Reservations, Off-Reservation Trust Lands, or
Census Oklahoma Tribal Statistical Areas) (USFS, 2020).
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6.1.8 Visual Resources
Several state and local laws and regulations are in place for the protection of visual and scenic
resources, including the following:
• The CCA, discussed in more detail in Section 6.1.9 (Coastal Zone), includes provisions about
protecting visual or scenic resources within the Coastal Zone.
• Under the California Scenic Highway Program, the Caltrans Director designates highways as
State Scenic Highways if they are highly scenic with natural features visible from the
highway and the local government has created a Corridor Protection Program to ensure
development is consistent with these visual resources (Caltrans, 2021b). The portion of
Interstate 5 that is northeast of the project area is eligible to be, but not yet designated as, a
State Scenic Highway (Caltrans, 2018).
• The San Diego County Zoning Ordinances General Regulations contain restrictions relating
to glare and outdoor lighting, including nighttime requirements for lighting use between
11:00 p.m. and dawn, as well as temporary exemptions (County of San Diego, 2020b).
• The San Diego County Light Pollution Code includes requirements for outdoor light fixtures;
however, federal government or State of California lighting fixtures are exempt (County of
San Diego, 2009).
• Through Council Policy 900-19, the City of San Diego offers protection for designated tree
resources, including landmark trees that have very high or unique aesthetic quality, from
being removed, damaged, or pruned without prior approval and permits from the city.
• The Tijuana River Valley Local Coastal Program Land Use Plan identifies steep hillsides as
potential scenic amenities that would be regulated through San Diego Municipal Code
§143.01 Environmentally Sensitive Lands Regulations (City of San Diego, 2007).
As discussed in Section 4.8 (Visual Resources), U.S.-side activities under the Proposed Action would
not include tree removal or modification, development on steep hillsides, or introduction of
features visible from Interstate 5. Additionally, construction and operational lighting would be
minimized when practicable and would comply with applicable light and glare standards.
Therefore, the Proposed Action would be expected to comply with applicable regulations pertaining
to visual resources.
6.1.9 Coastal Zone
Coastal Zone Management Act
Enacted by Congress in 1972, the CZMA provides for the management of coastal resources with the
goal "to preserve, protect, develop, and where possible, to restore or enhance, the resources of the
Nation's coastal zone" (16 U.S.C. § 1452). It requires that any federal action "within or outside the
coastal zone that affects any land or water use or natural resource of the coastal zone shall be
carried out in a manner which is consistent to the maximum extent practicable with the enforceable
policies of approved state management programs" (16 U.S.C. § 1452). In response, the CCMP was
created and federally certified in 1977 to implement the federal consistency procedures of the
CZMA.
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Under the CZMA, federal agency activities and development projects that have reasonably
foreseeable effects on the coastal zone must undergo a consistency determination. Although federal
lands are excluded from the coastal zone, effects on the coastal zone from projects on federal lands
must be included in the consistency determination. Similarly, any non-federal applicants for federal
authorizations (e.g., permits, licenses) and funding must undergo a consistency certification. Federal
consistency provisions shall include a statement indicating that the proposed action will be
undertaken in a manner that is consistent with the state coastal management program (in this case,
the CCMP). They shall also include a detailed description of the activity, its associated facilities, and
their coastal effects, and comprehensive data and information sufficient to support the consistency
statement. The CCC is responsible for reviewing these consistency analyses for federal projects
affecting the California coastal zone.
Consistency determinations are required for activities affecting land use, water use, or natural
resources in the coastal zone. Land and water uses include—but are not limited to—public access,
recreation, fishing, historic or cultural preservation, development, hazards management, marinas
and floodplain management, scenic and aesthetic enjoyment, and resource creation or restoration
projects. Natural resources include biological or physical resources that are found within a state's
coastal zone on a regular or cyclical basis. Biological and physical resources include—but are not
limited to—air, tidal and nontidal wetlands, ocean waters, estuaries, rivers, streams, lakes, aquifers,
submerged aquatic vegetation, land, plants, trees, minerals, fish, shellfish, invertebrates,
amphibians, birds, mammals, reptiles, and coastal resources of national significance (15 CFR §
930.11).
California Coastal Act
In 1972, due to growing public concern about coastal development and its impact on public access
and coastal resources, California voters passed Proposition 20, "The Coastal Initiative." The
initiative authorized the development of the California Coastal Plan and created what is now known
as the CCC to regulate development in the coastal zone. The CCA was passed soon after in 1976. All
consistency documents are reviewed for consistency with Chapter 3 of the CCA, which is the
underlying legal authority for the CCMP.
A key provision of the CCA is the requirement that local governments draft LCPs to guide coastal
zone development, conservation, and planning. Once an LCP is approved by the CCC, the review
authority for new development transfers from the CCC to the local authority, with the exception of
certain geographic areas including submerged lands and public trust lands (County of San Diego,
2018). The CCC also retains appellate authority over specified categories of development The
primary tool for implementing the LCP is the CDP. Development within the coastal zone generally
may not commence until a CDP has been issued either by the CCC or—if the LCP has been
approved—by the local authority.
Applicability to the Evaluated Alternatives
As noted in Section 3.10 (Coastal Zone), the Tijuana River Valley and adjacent coastal areas are
located within the coastal zone. Federal lands, including the ITP parcel and the flood control areas
upstream of Dairy Mart Road, are excluded from the coastal zone. However, pursuant to the CZMA,
actions on federal lands must nonetheless be reviewed for reasonably foreseeable effects on the
coastal zone.
Most of the U.S.-side Proposed Action components evaluated in this PEIS are located directly on
federal land with the exception of elements of Project B (Tijuana Canyon Flows to ITP). Piping
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under Project B would be located within the Tijuana River segment of the City of San Diego LCP
jurisdiction. On February 11, 2022, EPA submitted a jurisdictional review request to the CCC to
determine the applicable authorities, review requirements, and approval processes (e.g., CCC
versus City review of the federal consistency determination and CDP application) for the projects
that comprise the two action alternatives in this PEIS. EPA submitted a second request on August 4,
2022 seeking clarification regarding the applicability of the CDP process. CCC responded that the
CDP process does not apply to federal agency activities.
Pursuant to the CZMA, EPA prepared and requested CCC concurrence with a consistency
determination for the Core Projects. As discussed in Section 4.10 (Coastal Zone), construction and
implementation of the Core Projects would be generally consistent with the policies in the CCA.
However, due to some localized impacts to the coastal zone, implementation of the Core Projects
would "neither directly promote nor be inconsistent with" some individual policies of the CCA. See
Appendix H (Coastal Consistency Determination) for the full consistency determination.
Consistency determinations for the Supplemental Projects would be prepared and submitted
during the subsequent tiered NEPA analyses.
6.1.10 Air Quality and Odor
The amendments to the Clean Air Act mandated that EPA regulate the emissions of HAPs. HAPs are
pollutants that are known or suspected to cause cancer or other serious health effects. HAPs include
certain VOCs, pesticides, herbicides, and radionuclides. EPA has identified industry-specific
National Emission Standards for Hazardous Air Pollutants (NESHAPs) to protect public health and
welfare. These NESHAPs apply to all air emission sources that have the potential to emit at least 10
tons/yr of any single HAP or 25 tons/yr of multiple HAPs (40 CFR § 63.2). In addition to the
NESHAPs, EPA has developed Maximum Achievable Control Technology (MACT) standards for
particular source categories. MACT standards are based on the level of emission control currently
being achieved by the best-performing similar sources. Stationary sources identified as major
sources of HAPs are required to comply with MACT standards and perform an initial performance
test and regular monitoring to demonstrate compliance with NESHAPs.
Projects involving any new or modified air emission sources (e.g., boilers, emergency generators)
are required to apply the BACT, as defined by California law. If emissions exceed certain limits,
emissions offsets may be required. If modeled emissions of HAPs from new or modified stationary
sources are found to exceed specified health limits, the application of best available control
technology for toxics (T-BACT) would be required.
Under the Clean Air Act GCR, no federal agency can approve or undertake an action unless the
project has been demonstrated to conform to the applicable State Implementation Plan. A federal
action must not adversely affect the attainment and maintenance of the NAAQS or emission
reduction plans leading to attainment, nor can it cause or contribute to any new violation of any
standard. Conformity determinations are not required for federal actions if an applicability analysis
shows that the total direct and indirect emissions from the project would be below the applicable
de minimis thresholds (40 CFR § 93.153). Table 6-2 presents the de minimis thresholds for San
Diego County.
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Table 6-2. De Minimis Emissions Thresholds for General Conformity Applicability
Pollutant
San Diego County Attainment Status
De Minimis Emissions (tons/yr)
O3 (2015 standard)
Severe Nonattainment
25 a
O3 (2008 standard)
Severe Nonattainment
25 a
CO
Maintenance
100
Source: 40 CFR§ 93.153.
a- De minimis limits for ozone apply to the precursor pollutants, VOCs, and NOx. EPA is responsible for complying
with both the 2015 and 2008 ozone standards.
Under Regulation IV, Rule 51 of the SDAPCD, the discharge of air contaminants is prohibited if such
a discharge would cause "injury, detriment, nuisance or annoyance to any considerable number of
persons or to the public." Under this rule, an odor is considered a nuisance based on the number of
complaints received by the SDAPCD. Odor impacts are also regulated under California Health and
Safety Code Section 41700, San Diego County Zoning Ordinance Section 6318, and the San Diego
Municipal Code § 142.0710.
As discussed in Section 4.11 (Air Quality and Odor), emissions from the Proposed Action would not
exceed GCR de minimis thresholds. However, stringent pollution and odor control requirements
(i.e., BACT) would apply to Project A (Expanded ITP) due to emissions from the anaerobic digestion
process. Projects D and E (APTP Phases 1 and 2) would not be expected to trigger substantial
permitting, impact assessment, or emission control requirements for criteria pollutants or HAPs, as
the principal processes of non-industrial wastewater treatment operations (including primary and
secondary treatment) typically produce trace emissions that are considerably less than notable
regulatory applicability thresholds. The APTP would likely require an operational permit and
permits to operate emergency generators.
EPA and/or USIBWC would obtain and comply with all applicable permits for the Proposed Action.
6.1.11 Climate
In 2016, CEQ issued final guidance on GHG emissions and the effects of climate change (CEQ, 2016).
The guidance recommended that agencies quantify a proposed agency action's projected direct and
indirect GHG emissions and use the projected GHG emissions as a proxy for assessing potential
climate change impacts in NEPA analyses. The guidance also advises agencies to use their NEPA
review to consider alternatives that would make the actions and affected communities more
resilientto the effects of a changing climate (CEQ, 2016). This CEQ guidance is currently under
review for revision and update.
The recently issued EO 14008, Tackling the Climate Crisis at Home and Abroad (86 FR 7619), states
that the U.S. needs to achieve economywide net-zero emissions no later than 2050. It sets the
expectation that agencies with infrastructure investments shall reduce climate pollution and those
with permitting decisions shall consider the effects of GHG emissions and climate change in their
decisions.
The State of California has developed statewide GHG reduction goals through several legislative and
executive directives. In 2005, Governor Schwarzenegger issued EO S-3-05 to reduce statewide
emissions to 80 percent below 1990 levels by 2050. In 2006, the California Global Warming
Solutions Act (AB 32) called for the reduction of statewide emissions to 1990 levels by 2020. AB 32
required CARB to develop a Climate Change Scoping Plan to describe the approach to reach the goal
by 2020. The currentplan (2017) is being updated for the third time since being approved in 2008.
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The scoping plan recommends that local governments adopt adopted GHG emissions reduction
goals for year 2020 consistent with AB 32 and recommends local governments to adopt a goal for
municipal operations and communitywide emission reduction by approximately 15 percent from
current levels by 2020 (City of San Diego, 2015). In 2015, California Governor Brown issued EO B-
30-15, which established an interim goal to reduce statewide emissions to 40 percent below 1990
levels by 2030.
Under CEQA, agencies must analyze the GHG emissions of proposed projects, including an analysis
of the project's effect on climate change. In determining the significance of a project's impact,
agencies should consider the project's consistency with California's long-term climate goals (Cal.
Code Regs. tit. 14, § 15064.4). Threshold approaches are typically used to determine if the climate
impacts from the project are considered significant The City of San Diego's Climate Action Plan
Consistency Checklist, adopted in 2016, is currently being revised and is proposed to be codified in
the Land Development Code. It is meant to provide a streamlined review process for the GHG
analysis of proposed new development projects that trigger environmental review pursuant to
CEQA. Projects that are consistent with the Climate Action Plan as determined through the checklist
may rely on the GHG analysis in the Climate Action Plan. Projects that are inconsistent with the
Climate Action Plan must prepare a project-specific GHG analysis.
As discussed in Section 4.12 (Climate), while aspects of the Proposed Action may contribute to
specific strategies identified in the City of San Diego Climate Action Plan (e.g., anaerobic digestion to
reduce the volume of sludge sent to landfill, and methane capture from wastewater treatment
facilities), ultimately the Proposed Action would be inconsistent with the Climate Action Plan
because it would increase GHG emissions directly and through energy use, transportation, and
waste generation. This led to a determination of significant impact specific to climate impacts.
6.1.12 Solid and Hazardous Waste
Sludge disposal in the U.S. must comply with Section 503 of the CWA, which establishes
requirements for the management of biosolids generated during the treatment of municipal
wastewater. Section 503 establishes general requirements, pollutant limits, management practices,
operational standards, and requirements for the frequency of monitoring, recordkeeping, and
reporting for biosolids that are (i) applied to land to condition the soil or fertilize crops or other
vegetation grown in the soil, (ii) placed on a surface disposal site for final disposal, or (iii) fired in a
biosolids incinerator (40 C.F.R. § 503).
The California Hazardous Waste Control Act establishes regulations and incentives to ensure the
safe handling, treatment, recycling, and destruction of hazardous wastes (California Health and
Safety Code [CA H&SC] § 25100-25259). California's Hazardous Materials Business Plan program
provides threshold quantities for regulated hazardous substances. If quantities are exceeded, the
responsible entity is required to submit a Hazardous Materials Business Plan consisting of an
inventory of hazardous materials, an emergency response plan, and an employee training program
(CA H&SC § 25500-25547.8). For San Diego County, businesses that handle solid hazardous
materials in amounts greater than or equal to 500 pounds in a given year are required to submit a
Hazardous Materials Business Plan pursuant to the CAH&SC (San Diego County Code § 68.1113).
As discussed in Section 4.13 (Solid and Hazardous Waste), all evaluated alternatives are expected to
comply with applicable solid and hazardous waste standards if they generate hazardous waste from
typical cleaning and equipment maintenance wastes (e.g., solvents, oils, greases). With anaerobic
digestion for Project A (Expanded ITP), produced solids waste could be suitable for beneficial reuse
such as land application in the U.S. and, if so, would be required to comply with Section 503 of the
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CWA. Section 503 requirements would not apply to solids waste produced under Projects D and E
(APTP Phases 1 and 2), which would be disposed of in a landfill, or to solids waste to be disposed of
in Mexico.
6.1.13 Noise
Local ordinances regulate noise by establishing acceptable noise thresholds and potentially
requiring permits and noise mitigation for construction activities and noise-producing equipment.
Examples of mitigation methods include use of noise barriers (e.g., solid walls, fences, earthen
mounds), enclosures, and monitoring. The County of San Diego Noise Ordinance, the San Diego
County Code § 36.409, and the San Diego Municipal Code § 59.5.0404 state that, between 7 a.m. and
7 p.m., construction noise should not exceed a sound level of 75 dB at the property boundary line
when averaged over an eight-hour period. A permit is required for any construction-specific noise
between the hours of 7 p.m. and 7 a.m., regardless of land use (San Diego Municipal Code §
59.5.0404). Construction activities must adhere to applicable noise limits depending on its
jurisdictional location. Additionally, San Diego County Code § 36.410 states that impulsive noise
shall not exceed 82 dB in residential areas or 85 dB in agricultural areas at the property line for 25
percent of the minutes in the measurement period.
Residential areas have slightly lower maximum general sound thresholds than areas zoned for
agricultural, commercial, or industrial use (San Diego County Code § 36.404). The City of San Diego
Noise Abatement and Control Ordinance provides general sound level limits for different land uses,
as well as noise controls for maintenance and construction activities. Industrial and commercial
land uses do not have a tiered time-of-day limitation, while residential and commercial land uses
average sound level is more tightly restricted from 7 p.m. to 7 a.m. (San Diego Municipal Code §
59.5.0401). See Table 3-15 for a comparison of the county and city general sound level limitations.
As discussed in Section 4.18 (Noise), most Core and Supplemental Projects are expected to comply
with applicable noise standards with possible exceptions for work near residential property
boundaries (e.g., Option B1 trenching along Monument Road) and operation of the biogas-fired
engine and electrical generator under Project A. If nighttime construction is necessary, the
construction contractor would first obtain the appropriate permit.
6.1.14 Environmental Justice
EO 12898, Federal Actions to Address Environmental Justice in Minority Populations and Low-Income
Populations (59 FR 7629), specifically requires that federal agencies consider effects of proposed
actions—including human health, economic, and social impacts—on minority and low-income
communities when performing NEPA analyses. EO 13985, Advancing Racial Equity and Support for
Underserved Communities Through the Federal Government (86 FR 7009), directs federal agencies to
imbed equity into agency programs and activities by assessing the extent to which underserved
communities face systemic barriers in accessing opportunities and benefits related to the agency's
policies and programs and directs the agency to develop a plan for addressing these barriers. To
help achieve environmental justice, EPA's E.0.13985 Equity Action Plan calls for EPA to develop
more thorough analyses on the accumulation of multiple environmental and social stressors during
decision making (including environmental decision making), conduct a critical review of existing
data and methods for considering vulnerabilities due to burdens, and identify opportunities and
develop recommendations to address vulnerabilities due to overburdens during decision contexts
(EPA, 2022e). EO 14008, Tackling the Climate Crisis at Home and Abroad (86 FR 7619), directs
federal agencies to address disproportionately high and adverse human health, environmental,
climate-related, and cumulative impacts and associated economic effects on DACs.
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Both minority and low-income populations, as well as communities overburdened for one or more
environmental indicators, are present in the EJ Study Area, which includes communities in the
vicinity of construction and operational activities under the Proposed Action. Therefore, EOs
12898,13985, and 14008 require that EPA and USIBWC complete an analysis to determine
whether, and to what extent, the projects would result in disproportionately high and adverse
effects on the minority and low-income populations, including the potential for exacerbation of
existing social, economic, health, or environmental burdens. EPA and USIBWC would develop and
incorporate mitigation measures as described in Section 5 (Mitigation Measures and Performance
Monitoring) to avoid, minimize, or compensate for potential effects. See Sections 3.20, 4.20, and
Appendix I (Supplemental Data for Environmental Justice Analysis) for additional information on
the environmental justice review and analysis conducted for the Proposed Action.
6.2 Mexican Regulations and Permits
Mexico authorities would be responsible for preparing environmental impact analyses for actions
in Mexico pursuant to Mexican laws and authorities.
Components of the Proposed Action that occur in Mexico would require additional environmental
review in the form of an Environmental Assessment Document ("Manifestacion de Impacto
Ambiental" [MIA]). Development of an MIA ensures that actions in Mexico are compliant with
Mexican regulations, protect environmental resources, and prevent adverse impacts (Sanchez-
Triana & Enriquez, 2007). The MIA serves as a technical and legal document to present the
evaluation of alternatives, identify potential impacts, and set forth mitigation measures to reduce
adverse impacts, including impacts from construction, O&M, and decommissioning activities
(Parsons, 2005; Sanchez-Triana & Enriquez, 2007; White &Case LLP, 2019). The MIA would be
subject to review by federal, state, and local governments, which may provide comments, require
additional mitigation measures, require additional risk assessments, report the action, or deny
issuing authorization for the action (Parsons, 2005; Sanchez-Triana & Enriquez, 2007). As part of
the MIA process, a summary of the action must be published in a newspaper, the MIA must be made
public if requested, and public comments on the MIA must be included in the action's
administrative record.
Recent BWIP-funded projects in Tijuana—e.g., Rehabilitation of the International Collector (Phase
1) and Tijuana River diversion rehabilitation; see Section 2.9 (Related Projects)—involved public
outreach in compliance with NADBank community participation criteria. Specifically, public
outreach included the formation of a Citizen Information Committee, distribution of factsheets to
the community adjacent to the project location, publication of an information note in the local
newspaper, and a survey to gauge community support for the projects. Components of the
Proposed Action in Mexico funded through USMCA Implementation Act appropriations or BWIP
would potentially undergo a similar public outreach and engagement process.
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Additional Mexican regulations, standards, and permitting requirements also exist to protect
environmental and human health. The following represent example aspects of the Proposed Action
that may have environmental compliance implications in Mexico:
• Temporary effects from construction in Mexico under Projects B (Tijuana Canyon Flows to
ITP), C (Tijuana Sewer Repairs), D (APTP Phase 1), G (New SABTP), H (Tijuana WWTP
Treated Effluent Reuse), and I (ITP Treated Effluent Reuse)—subject to regulations and
permitting requirements to protect a broad range of resource areas including water
resources, geologic resources, air quality, biological resources, cultural resources, land use,
visual resources, solid and hazardous waste, public health and safety, transportation, and
noise.
• Solids waste transport, disposal, and/or land application in Mexico under Projects A
(Expanded ITP) and G (New SABTP)—subject to regulations on transportation, solid and
hazardous waste, and land use.
• Treated effluent discharges from Mexico under Project G—subject to water quality
standards, wastewater permitting requirements, and regulations to protect biological
resources.
• Treated effluent reuse in Mexico under Projects H and I—subject to drinking water
standards and regulations protecting water quality.
See Section 6.2 of the Final Supplemental EIS for Clean Water Act Compliance at the South Bay
International Wastewater Treatment Plant (Parsons, 2005) for additional background on
potentially applicable Mexican regulations and permits.73
73 See https://www.ibwc.gov/Files/Web/Final_SEIS.pdf.
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Public and Interagency Coordination
7. PUBLIC AND INTERAGENCY COORDINATION
7.1 Interagency Stakeholder Coordination Prior to Draft PEIS Development
Before developing the Draft PEIS, EPA initiated early stakeholder coordination and outreach to
engage interested international, federal, state, and local entities and representatives. This process
was integral to forming the alternatives presented in the Draft PEIS and this Final PEIS. Initially,
EPA led the public and interagency coordination process as mandated by the USMCA
Implementation Act In October 2021, EPA and USIBWC agreed to become joint lead agencies for
the NEPA process as discussed in Section 1.5 (Purpose and Scope of the Programmatic EIS).
7.1.1 Eligible Public Entities Coordinating Group
The USMCA Implementation Act directed EPA to carry out the planning, design, construction, and
O&M of high-priority treatment works "in coordination with eligible public entities." Based on that
direction, EPA established the EPECG, consisting of federal, state, and local stakeholders and
solicited their input on the set of project options to be considered for evaluation in an EIS.
The EPECG membership roster consists of the following public entities:
• EPA co-chairs:
— EPA Office of Wastewater Management
— EPA Region 9, Water Division
• Binational entities:
— North American Development Bank (NADBank)
• U.S. federal entities:
— U.S. Army Corps of Engineers (USACE)
— U.S. Customs and Border Protection (CBP)
— U.S. Department of Commerce—represented by the U.S. International Trade
Administration
— U.S. Department of State
— U.S. Fish and Wildlife Service (USFWS)
— U.S. International Boundary and Water Commission (USIBWC)
— U.S. Navy
• U.S. state, regional, and local public entities:
— California Environmental Protection Agency (CalEPA)
— California natural resource agency—represented by the Tijuana River National
Estuarine Research Reserve (TRNERR) with the California State Coastal Conservancy as
delegate
— San Diego Regional Water Quality Control Board (SDRWQCB, or San Diego Water Board)
— San Diego County
— City of Chula Vista
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— City of Coronado
— City of Imperial Beach
— City of San Diego
— Port of San Diego
To date, the EPECG has met on 12 occasions, all by conference call. Coordination topics addressed at
EPECG meetings have included, among other topics: the approach to public engagement; the project
evaluation and selection process, including member feedback on the merits and concerns of each
project option; overview of the technical analysis approach, high-level criteria to be used in the
evaluation, and the long-term projects identified for inclusion in the evaluation; the identification
and optimization of alternatives; the planning and evaluation of short-term project options;
appropriate use of USMCA funds; and recent research efforts.
EPECG Meeting 1—June 2, 2020 • EPECG Meeting 7—August 4, 2021
EPECG Meeting 2—July 29, 2020 • EPECG Meeting 8—November 8, 2021
EPECG Meeting 3—October 1, 2020 • EPECG Meeting 9—March 7, 2022
EPECG Meeting 4—November 19, 2020 • EPECG Meeting 10—June 24, 2022
EPECG Meeting 5—February 25, 2021 • EPECG Meeting 11—August 5, 2022
EPECG Meeting 6—May 19, 2021 • EPECG Meeting 12—October 4, 2022
As part of EPA's process to assess technical options to address the transboundary wastewater
flows, the supporting contractors conducted 18 individual virtual interviews with EPECG members
in January and February 2021. The goal of these interviews was to understand the EPECG members'
perspectives on the range of long-term projects currently being considered, synergies between
projects, and the larger contextual considerations that may impact project success. Responses were
aggregated and not attributed to specific individuals. High-level themes that emerged from the
interviews were shared with EPA. The EPECG members provided input on a range of topics,
including:
• The most pressing negative impacts and pollutants facing the Tijuana River watershed.
• Key projects or combinations of projects that may have the most promise to address the
impacts or issues of most importance.
• The most important factors for implementing a solution to address transboundary flows
related to USMCA investments.
• Critical actions that could be taken within Mexico to aid in ensuring long-term investments
and reliable O&M of infrastructure.
• Questions and/or additional information that EPECG members have for EPA and/or other
entities engaged in the process.
7.1.2 Technical Expert Consultation Process (TECP)
Early in the project development phase, EPA recognized the need to obtain and incorporate
information from technical experts to inform the feasibility and alternatives analysis and to bring
the USMCA Mitigation of Contaminated Transboundary Flows project team up to speed on existing
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information. As a result, EPA developed the TECP and involved stakeholders who were familiar
with the technical aspects of transboundary flows and existing infrastructure. Specifically, the
following stakeholders either 1) own or operate infrastructure or resources within the project area
or 2) maintain data, reports, and other technical information that are critical to understanding
transboundary flows and potential solutions:
• EPA Region 9 and Headquarters staff.
• U.S. International Boundary and Water Commission (USIBWC) and Comision International
de Limites y Aquas, Seccion Mexicana (CILA).
• North American Development Bank (NADBank).
• The County of San Diego and their consultant, HDR.
• The City of San Diego and representatives from the South Bay Water Reclamation Plant
(SBWRP).
• U.S. Customs and Border Protection (CBP).
• Scripps Institution of Oceanography at the University of California San Diego.
• San Diego Regional Water Quality Control Board (SDRWQCB, San Diego Water Board).
• California Department of Parks and Recreation (CDPR).
After reviewing documents, reports, and data provided by the TECP, EPA scheduled meetings with
individual TECP stakeholders to 1) introduce the USMCA Mitigation of Contaminated
Transboundary Flows Project team; 2) assign a main point of contact between EPA and the TECP
stakeholder; and 3) request documentation, additional technical information, or clarification to
further inform the feasibility and alternatives analysis. In some cases, EPA provided a list of
questions to discuss with TECP stakeholders during the meetings. TECP stakeholders responded to
the questions and provided additional technical documentation to EPA, as requested. The following
presents a summary of the TECP meetings that have occurred to date:
• Meeting with USIBWC on September 17, 2020:
— Discussed the existing footprint and treatment processes of the ITP, the ability for the
ITP to handle additional flows during wet weather, and other operational and
performance challenges faced by the ITP and the collection system.
• Meeting with the County of San Diego and HDR on October 16, 2020:
— Discussed the Scripps Institution of Oceanography draft study and findings regarding
beach impacts from coastal discharges of untreated wastewater.
— Discussed issues with flooding of Monument Road in addition to road closures, estuary
impacts, and lack of water quality data from Goat Canyon.
— Discussed the operation of various existing infrastructure including PB-CILA, PB1-A, the
SBOO, levees, border walls, and the ITP.
• Meetings with the City of San Diego on November 2, 2020, and November 9, 2020:
— Discussed source control in Mexico as a barrier to treating water for beneficial reuse,
the potential of selling SBWRP and the SBOO assets to the federal government, and
evaluating the potential for treatment system consolidation and regionalization.
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— The city provided additional information on asset management of SBWRP and the
SBOO.
— Discussed the availability of data for hydraulic modeling and profiles of SBWRP and
SBOO, mapping and land use surrounding SBWRP, stress testing, asset management
documentation, hydraulic modeling, design basis and hydraulic profiles for SBWRP and
SBOO, operating costs, and sludge disposal.
• Meetings with NADBank on October 29, 2020, and December 2, 2020:
— Discussed the overall NEPA process.
— Participants requested additional information regarding flow diagrams of the systems
(including diversion structure operation); information on infrastructure upgrades;
standard operating procedures for operating PB-CILA; plan, schedule, and cost of
maintaining the canyon collector system; and the availability of water quality
monitoring data.
— Discussed questions regarding the operation, performance, and possibility of failure for
assets (particularly PB1-A, PB1-B, and PB-CILA); seasonal flow trends; historical data on
asset performance; service life of assets; regular O&M for diversion infrastructure and
the canyon collector system; and water reuse.
• Meeting with CDPRon December 4, 2020:
— Discussed Yogurt Canyon drainage; sediment and trash deposition; issues with road
flooding, seasonal flooding, and the connection between flooding and public access
issues to beach and parks; loss of salt marsh habitat; the option of a proposed pilot
channel; and concerns regarding its invasive impacts to the salt marsh.
• PG Environmental site visits to ITP and wastewater infrastructure in the U.S. and Mexico,
May 25-27, 2021:
— Met with representatives from IBWC and Veolia, who provided a plant tour of the ITP.
Discussed operational challenges and constraints, condition of existing plant equipment,
and site suitability for expanding the plant
— Met with representatives from CBP, who provided a tour of the U.S.-side canyon flow
diversion structures along the international border. Discussed challenges with
patrolling the border infrastructure, including pools of wastewater during dry weather
and high-flow events during wet weather.
— Met with representatives from CESPT and CILA, who provided a tour of PB-CILA and
other Mexico-side pump stations. Discussed current condition of pumping equipment,
operational protocols and procedures, and operational challenges and constraints.
— Met with representatives from the County of San Diego, who provided a tour of the
Smuggler's Gulch trash boom. Discussed trash boom design, efficacy, and maintenance
requirements.
— Met with representatives from CDPR, who provided a tour of the Goat Canyon sediment
basin and trash boom. Discussed sediment basin and trash boom design, efficacy, and
maintenance requirements.
The USMCA Mitigation of Contaminated Transboundary Flows Project team does not have
additional meetings scheduled with TECP stakeholders at this time, but may identify the need for
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additional meetings, depending upon the need for technical input for the feasibility and alternatives
analysis.
7.1.3 Natural Resources Workshop
On March 9 and April 2, 2021, EPA hosted and facilitated a Natural Resources Workshop for the
USMCA Mitigation of Contaminated Transboundary Flows Project EPA invited natural resource
managers and conservation specialists in the San Diego region to the workshop to solicit input
related to biological resources to inform the planning process. The workshop was divided into two
parts (two-hour sessions each) and was focused on the following:
• Part 1 (March 9, 2021)—EPA summarized the project options being considered; described
the natural resource data collection and review efforts to date; and requested relevant
information on flora and fauna, such as survey and monitoring data, ongoing projects and
management efforts, and species recovery plans.
• Part 2 (April 2, 2021)—EPA focused on discussing potential water quality and river flow
changes and concerns downstream of the U.S.-Mexico border and the implications on
natural and ecological resource management in the Tijuana River and Estuary.
Participants included individuals from the following agencies and organizations: USFWS, USDA-
NRCS, USIBWC, TRNERR, CDPR, CDFW, County of San Diego, City of San Diego, City of Imperial
Beach, San Diego Management and Monitoring Program, USGS, U.S. Navy, California State Coastal
Conservancy, and Bureau of Land Management
7.2 Regulatory Consultation
7.2.1 Endangered Species Act Section 7 Consultation
Consultation with USFWS
EPA engaged in preliminary discussions and early coordination with USFWS, including some prior
to initiation of the NEPA process, which included the following:
• On December 16, 2020, EPA conducted an introductory meeting with USFWS to notify them
of the Proposed Action and begin early coordination on the action and its potential effects.
• EPA hosted and facilitated the Natural Resources Workshop, including USFWS as a
participant See Section 7.1.3 (Natural Resources Workshop).
• On July 1, 2021, EPA met with USFWS and discussed an overview of the Proposed Action,
the status of alternatives development, and a proposed approach to ESA Section 7
consultation.
• On January 5, 2022, EPA met with USFWS and discussed updates and a summary of listed
species with the potential for project-related effects.
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• On February 9, 2022, EPA's biological consultants conducted a site visit with USFWS to
evaluate site conditions in the proposed Action Area74 and discuss potential impacts on
federally listed species.
The scope of the ESA Section 7 consultation is limited to the Core Projects. Supplemental Projects
would be subject to the ESA but would undergo consultation at a later date, likely in support of the
subsequent tiered NEPA analyses for those projects. On May 25, 2022, EPA submitted to USFWS a
Biological Assessment for review through informal consultation and a request for concurrence with
a finding of may affect, but is not likely to adversely affect all listed species and designated critical
habitat with the potential to occur within the Action Area—see Appendix D (USFWS Biological
Assessment).75 Since the submittal of the Biological Assessment, EPA has provided additional
information and analyses in response to inquiries from USFWS. Based on continued informal
consultation with USFWS, EPA anticipates receiving concurrence with the not likely to adversely
affect finding. It is possible that USFWS may identify additional conservation measures necessary to
ensure that reductions in freshwater river flows under the Core Projects would not result in a net
loss of downstream riparian habitat for the least Bell's vireo. EPA will continue to coordinate with
USFWS pursuant to ESA Section 7 for the Core Projects throughout the NEPA process. Mitigation
measures that have been identified in consultation with USFWS as of the date of this Final PEIS are
included in Section 5 (Mitigation Measures and Performance Monitoring). If additional
conservation measures are identified later in the consultation process with USFWS, they will be
incorporated into the ROD for this PEIS and applied to the Core Projects (Mitigation Measure BR-
25).
Consultation with NMFS
When developing the EID, EPA engaged in preliminary discussion with NMFS staff to inform them
of the development of alternatives leading up to the release of the Draft PEIS and this Final PEIS.
• On February 26, 2021, EPA provided a joint presentation to NMFS that included information
on the 10 projects identified in Section 2.1.1 (Identification of Projects to Undergo
Feasibility Analysis) that were under consideration in the EID.
• On July 7, 2021, EPA provided a second presentation to NMFS that included an update on
three tentative project alternatives that would be brought forward to the PEIS.
• On August 4, 2021, a technical memorandum was provided to NMFS for review. The
memorandum described the Action Area76 potentially affected by the Proposed Action
considered for assessment in the PEIS. The memorandum also contained a list of species
that EPA had determined could occur within this Action Area and a table of key life-history
74 This Action Area, related to inland biological resources, is defined in Appendix D (USFWS Biological
Assessment).
75 The Biological Assessment submitted by EPA on May 25, 2022 was marked as a "Draft." EPA has since
responded via email to USFWS's follow-up requests for information and clarification, rather than by
submitting a revised or final Biological Assessment. Based on continued informal consultation with USFWS,
EPA does not anticipate the need to submit a revised or final Biological Assessment.
76 This Action Area, related to marine biological resources and EFH, is defined in Appendix F (NMFS Biological
Assessment).
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and management references compiled to inform the biological assessment The technical
memorandum also included a discussion of potential EFH in the Action Area. On August 25,
2021, NMFS provided an email response with comments relating to the technical
memorandum.
Since these discussions, EPA completed the alternatives analysis (see Section 2.1.3 [Alternatives
Analysis]), which identified the Alternatives 1 and 2 considered in this PEIS.
The scope of the ESA Section 7 consultation is limited to the Core Projects. Supplemental Projects
would be subject to the ESA but would undergo consultation at a later date, likely in support of the
subsequent tiered NEPA analyses for those projects. On May 5, 2022, EPA submitted to NMFS a
preliminary draft combined Biological Assessment and EFH Assessment report seeking feedback.
On May 25, 2022, EPA submitted to NMFS a draft Biological Assessment and EFH Assessment
report for review, to initiate informal consultation, and to request concurrence. On May 27, 2022,
NMFS provided comments on the May 5, 2022 preliminary draft Biological Assessment and EFH
Assessment report and requested that EPA make appropriate revisions before submitting the
Biological Assessment and EFH Assessment to initiate consultation pursuant to ESA Section 7 and
the Magnuson-Stevens Act. Since receiving the comments from NMFS on the preliminary draft, EPA
decided to separate the Biological Assessment and EFH Assessment into their own distinct reports.
On July 22, 2022, EPA requested to initiate formal consultation pursuantto 50 CFR § 402.14 via
transmittal of a Biological Assessment, which incorporated revisions intended to address NMFS's
ESA Section 7 consultation-specific comments on the May 5, 2022 preliminary draft Biological
Assessment In the July 22, 2022 NMFS Biological Assessment (provided in Appendix F), EPA
determined that implementation of the Core Projects may affect, and is likely to adversely affect
listed species identified as having medium to high potential to occur within the proposed Action
Area and may affect, but is not likely to adversely affect all other listed species. Since submittal of the
NMFS Biological Assessment, EPA has provided additional information and analyses in response to
inquiries from NMFS. Based on continued consultation, EPA anticipates that NMFS will issue a
Biological Opinion that identifies reasonable and prudent measures to minimize potential adverse
effects to ESA-listed species due to SBOO discharges. EPA will continue to coordinate with NMFS
pursuantto ESA Section 7 for the Core Projects throughout the NEPA process. Mitigation measures
that have been identified in consultation with NMFS as of the date of this Final PEIS are included in
Section 5 (Mitigation Measures and Performance Monitoring). If additional reasonable and prudent
measures are identified later in the consultation process with NMFS, they will be incorporated into
the ROD for this PEIS and applied to the Core Projects (Mitigation Measure BR-34).
7.2.2 Magnuson-Stevens Fishery Conservation and Management Act Consultation (Essential Fish
Habitat)
Consultation regarding effects on EFH with NMFS has been, and will continue to be, conducted
concurrent with discussions and subsequent consultation with NMFS on ESA-listed species. As
discussed in Section 7.2.1 (Consultation with NMFS), EPA initially submitted a combined draft
Biological Assessment and EFH Assessment report and subsequently decided to separate the two
assessments into their own distinct reports. On August 10, 2022, EPA submitted an EFH
Assessment that incorporated revisions that address NMFS's comments related to EFH on the May
5, 2022 preliminary draft Biological Assessment and EFH Assessment report. EPA's transmittal of
the EFH Assessment on August 10, 2022 requested NMFS's review pursuant to the Magnuson-
Stevens Act and 50 CFR Part 600. In the EFH Assessment (provided in Appendix G), EPA
determined that the Core Projects would adversely affect EFH within the Action Area due to
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increased discharges of treated effluent via the SBOO and potential disturbance of seabed
communities due to anchor deployment Mitigation measures that have been identified in
consultation with NMFS as of the date of this Final PEIS are included in Section 5 (Mitigation
Measures and Performance Monitoring). If additional conservation measures are identified later in
the consultation process with NMFS, they will be incorporated into the ROD for this PEIS and
applied to the Core Projects. EPA and USIBWC will not sign the ROD for this PEIS until Magnuson-
Stevens Act consultation is completed.
7.2.3 National Historic Preservation Act Section 106 Consultation
Discussions with OHP regarding the Proposed Action began with a meeting with Associate State
Archaeologist Jeffrey Delsescaux on December 15, 2020. Mr. Delsescaux provided information from
a recent cultural resources study for the Tijuana River Flood Control Project conducted within the
APE for the Proposed Action. The study recorded one new resource not on file at the SCIC, CA-SDI-
23075, and it was thus added to the list of cultural resources to consider in the Class III Cultural
Resource Inventory for the Proposed Action.
On May 25, 2022, EPA submitted a formal request for consultation under NHPA Section 106 and
concurrence on the findings of the Class III Cultural Resource Inventory and EPA's finding of no
historic properties affected for the Proposed Action.
OHP responded in a letter dated June 26, 2022, stating that EPA may instead have a finding of no
adverse effect since EPA is imposing avoidance conditions to prevent adverse effects to the four
unevaluated resources within the APE. OHP also stated that it would not object to a finding of no
adverse effect pursuant to 36 CFR § 800.5(b).
EPA responded in a letter dated September 19, 2022, stating that it agrees with OHP's comments
and is treating the four previously unevaluated resources as eligible for the purposes of this
undertaking. As such, EPA also stated that it is revising the previous finding of no historic properties
affected to a finding of no adverse effect to conclude consultation. EPA also provided OHP with a
copy of the Final Class III Cultural Resource Inventory for the USMCA Mitigation of Contaminated
Transboundary Flows Project in the Tijuana Watershed in San Diego, California (Daniels et al., 2022),
the public version of which is provided in Appendix C. OHP responded in a letter dated October 20,
2022, reaffirming that they do not object to the finding of no adverse effect.
For communications related to Section 106 consultation with OHP, see Appendix M (NHPA Section
106 Correspondence).
7.2.4 Government-to-Government Consultation with Native American Tribes
On March 30, 2021, letters were mailed to local tribal contacts provided by the NAHC and EPA
tribal liaison seeking early engagement and requesting any knowledge of cultural resources in the
USMCA project areas and any potential concerns regarding the Proposed Action and its potential
for adverse effects on cultural resources.77 Tribes with available email addresses were provided
electronic copies of the outreach as well on April 2, 2021. The Rincon Band of Luiseno Indians
responded in a letter dated April 28, 2021, stating thatthey have no additional information
77 A separate version of this outreach letter was mailed to Carmen Lucas of the Kwaaymii Laguna Band of
Mission Indians on April 20, 2021.
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concerning potential impacts on cultural resources. The Rincon Band recommended that EPA
coordinate with the Kumeyaay Nation to address and mitigate impacts to cultural resources and
requested to be included in future correspondence for the USMCA project No other tribal contacts
responded to EPA's outreach letter. Separately, in response to the NOI to prepare an EIS (see
Section 7.3.4.1 [Public Notification and Scoping Meeting]), the Viejas Band of Kumeyaay Indians
commented on April 8, 2021, that the USMCA project site has cultural significance or ties to them
and requested that a Kumeyaay Cultural Monitor be onsite for ground-disturbing activities. Native
American participation was included as part of the pedestrian survey for the Class III Cultural
Resource Inventory. During the pedestrian survey, Deangelo Espinoza from the Viejas Band of
Kumeyaay Indians served as the Kumeyaay Cultural Monitor.
Although EPA did not need to consult with tribes in reaching the finding that the Proposed Action
would not affect historic properties, EPA distributed notification letters and notices of the
availability of the Draft PEIS to the tribal contacts provided by the NAHC and EPA tribal liaison—
see Appendix N (Tribal Outreach Correspondence).78 The notification letters included copies of the
Draft Class III Cultural Resource Inventory and documentation specified in 40 CFR § 800.11(e)
supporting the finding, and notified tribal contacts that EPA had requested OHP concurrence on this
determination for the Proposed Action. This letter covered the full scope of the Proposed Action,
including all projects proposed in this PEIS. EPA received one response from Cheryl Madrigal of the
Rincon Band of Luiseno Indians in an email dated July 7, 2022, stating that the project location is
not within the traditional use area of the Rincon Band. The Rincon Band deferred the review of the
finding to the Kumeyaay Nation, including the Viejas Band of Kumeyaay Indians, who served as the
Native American monitors during the pedestrian survey. EPA and USIBWC have not received any
other response letters as of the date of this Final PEIS.
As noted above in Section 7.2.3 (National Historic Preservation Act Section 106 Consultation),
consultation under NHPA Section 106 has concluded with a finding of no adverse effect. Continued
consultation with Indian tribes will occur as needed. EPA recognizes that consultation is an ongoing
process of communication that may include written correspondence, meetings, telephone
conferences, site visits, and emails, and will employ these methods of consultation to seek
agreement with tribes regarding matters arising out of the Section 106 process as necessary, in
accordance with 36 CFR § 800.16(f). EPA recognizes the special expertise of Indian tribes to
determine the religious and cultural significance of historic properties to them per 36 CFR §
800.4(c)(1) and recognizes that 36 CFR§ 800.5(a) requires that agencies apply the criteria of
adverse effect in consultation with Indian tribes.
7.3 Public Engagement and Review
7.3.1 Public Information Meetings
To date, EPA has conducted eight public listening sessions with broader stakeholders, all by
conference call. Topics addressed at the public listening sessions have included, among other topics,
update on short-term impact projects; overview of the technical analysis approach, high-level
criteria to be used in the evaluation, and the long-term projects identified for inclusion in the
78 As described in Section 7.2.3 (National Historic Preservation Act Section 106 Consultation), EPA initially
reached a finding of no historic properties affected for the Proposed Action. The notification letters sent to
tribal contacts indicated this finding. EPA later revised this to a finding of no adverse effect based on feedback
from OHP.
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evaluation; the identification and optimization of alternatives; information on the NEPA scoping
process and important dates for stakeholders; and addressing public stakeholders' key questions.
Upcoming public listening sessions will be announced by EPA.
• Public Information Meeting 1—June 25, 2020
• Public Information Meeting 2—November 20, 2020
• Public Information Meeting 3—February 26, 2021
• Public Information Meeting 4—May 24, 2021
• Public Information Meeting 5—August 6, 2021
• Public Information Meeting 6—November 8, 2021
• Public Information Meeting 7—June 28, 2022
• Public Information Meeting 8—October 5, 2022
7.3.2 USIBWC Citizens Forum Meetings
The USIBWC Citizens Forum was established in 2002 to facilitate the exchange of information
between USIBWC and members of the public about Commission activities in San Diego County. The
Citizens Forum is intended to bring together community members enabling the early and continued
two-way flow of information, concerns, values, and needs between USIBWC and the general public,
environmentalists, government agencies, municipalities, and other interested parties. The Citizens
Forum meetings are conducted three times per year and cover topics including, but not limited to,
projects within the Tijuana River watershed, wastewater treatment operations along the U.S.-
Mexico border, and the status of the USMCA Mitigation of Contaminated Transboundary Flows
Project Meeting minutes and presentation materials are available on the USIBWC Citizens Forum
website.79
7.3.3 South County Environmental Justice Taskforce
The South County Environmental Justice Taskforce (SCEJTF), chaired by San Diego County District 1
Supervisor Nora Vargas, was created in 2021 to bring together San Diego leaders on public health
issues and pollution affecting residents in the Tijuana River Valley. One of its main purposes is to
improve health outcomes, particularly in severely impacted communities with environmental
justice concerns in San Diego County. By facilitating diverse stakeholder engagement, it aims at
broadening awareness and support to implement innovative ideas. The SCEJTF is comprised of
binational entities representing various sectors including government, community groups,
academia, and nonprofit including members from environmental justice organizations. The
Taskforce meets quarterly and as needed. Following NEPA public scoping, EPA provided overview
presentations on and answered questions posed by Taskforce members on the USMCA project in
June and September 2021. EPA continues being an active participant in SCEJTF meetings.
79 See https://ibwc.gov/Citizens_Forums/CF_SBIWTP.html.
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7.3.4 NEPA Public Scoping
7.3.4.1 Public Notification and Scoping Meeting
On April 5, 2021, EPA published in the Federal Register a NOI to prepare an EIS (86 FR 17595; this
notice is available at www.federalregister.gov). The publication initiated public scoping by
providing a notice of virtual public scoping meetings and request for comments from federal, state,
and local agencies, Native American tribes, and the public. EPA established a 45-day public
comment period for the scoping process that concluded on May 20, 2021.
EPA published public notices of their intent to prepare an EIS, notice of public scoping meeting, and
request for comments in two local newspapers: the San Diego Union-Tribune for three consecutive
days starting on April 6, 2021, and the Imperial Beach Eagle and Times on April 8, 2021.
Additionally, EPA notified approximately 85 "potentially interested parties" (e.g., agencies,
organizations, and businesses) through a combination of emailed flyers, directly mailed flyers, a
listserv distribution (for NADBank), and website submittals. EPA also posted notices on the EPA
project website (https://www.epa.gov/sustainable-water-infrastructure/usmca-tijuana-river-
watershed). Appendix 0 (Distribution List) includes the list of the potentially interested parties that
received public notice distributions.
As described in the NOI and other public scoping materials, EPA had not yet identified the
alternatives to be evaluated in the EIS but anticipated that each alternative would consist of one or
more of the 10 projects that were undergoing feasibility analysis at the time, as described in Section
2.1 (Formulation of Alternatives).
EPA hosted a virtual public scoping meeting on April 20, 2021, at 6 p.m. Pacific Daylight Time (PDT)
to provide information to the public on the Proposed Action and to accept public comments. The
presentation lasted approximately 30 minutes and was followed by a formal public comment
period for the meeting participants who submitted comments both orally and in written form
within the virtual meeting platform. The presentation included an overview of the USMCA, the
NEPA and scoping process, an anticipated schedule, technical analysis process, scope of the issues
to be addressed, overview of the existing systems, and a description of the proposed projects.
Nearly 150 people attended the virtual public scoping meeting and the comments received during
the virtual meeting were collected, reviewed, and considered during the preparation of the PEIS.
The meeting materials were presented in a bilingual written format (English/Spanish) and audio
was made available during the meeting with simultaneous Spanish interpretation services. Closed
captioning was also available to participants during the meeting. A recording of the public scoping
meeting was made available on the EPA Tijuana River Watershed NEPA Implementation project
website.80
7.3.4.2 Summary of Scoping Comments
EPA received scoping comments from public citizens, federal and tribal representatives, non-
governmental organizations, and a variety of other stakeholders. Comments were received by email
and as written and spoken comments during the public scoping meeting. Commenters provided
80 See https://www.epa.gov/sustainable-water-infrastructure/tijuana-river-watershed-nepa-
implementation.
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input on the following topics: the proposed projects; the purpose and need; funding sources and
scope of funding; timing and schedule; alternatives; the binational nature of the issues; Tijuana
infrastructure; effects on tourism, recreation, water quality, terrestrial and estuarine habitats,
streams and riparian habitats, air quality and odor, public health, and cultural resources; Navy
operations, environmental justice, and climate change; mitigation and BMPs; and coordination and
consultation with agency stakeholders.
7.3.4.3 Summary of Submitted Alternatives, Information, and Analyses
During the NEPA public scoping period for this PEIS, EPA and USIBWC received scoping comments
from public citizens, federal and tribal representatives, non-governmental organizations, and a
variety of other stakeholders. Some of these comments suggested projects to be considered in the
PEIS and/or provided information or analyses for EPA and USIBWC consideration. As discussed in
Section 2.7.3 (Other Projects Identified Based on Public Scoping Comments), commenters
submitted the following alternatives for EPA consideration: Separation of the stormwater and
sewage systems in Tijuana, Utilization of a treatment plant in Mexico for reclamation and reuse of
untreated wastewater and/or treated effluent, Installation of micro-treatment systems in Tijuana,
Promotion of home (domestic) water reuse in Tijuana, Establishment of a recycling program in
Tijuana to prevent solvents, detergents, and chemicals from entering the waste stream,
Remediation and restoration of the Tijuana River Valley to its historical environmental conditions,
and Extension of the SBOO to deeper offshore waters. Additional information about the range of
alternatives considered is provided in Sections 2.2 (Proposed Action and Range of Alternatives
Evaluated in This PEIS) and 2.7 (Alternatives Eliminated from Evaluation in This PEIS).
7.3.5 Public Review of Draft PEIS
7.3.5.1 Public Notification and Meetings
On June 17, 2022, EPA and USIBWC published an NOA, a notice of virtual public comment meetings,
and a request for comments on the Draft PEIS (87 FR 36487). The public comment period for the
Draft PEIS lasted for a period of 45 days and concluded on August 1, 2022. In addition to the NOA in
the Federal Register, EPA and USIBWC distributed notices of the Draft PEIS to all agencies,
organizations, elected officials, Native American and tribal Representatives, local businesses and
residences, and electronic mailing lists as identified in Appendix 0 (Distribution List). EPA and
USIBWC also submitted the Draft PEIS to the California Office of Planning and Research for review
by state agencies and publication on the CEQAnet website (SCH# 2022060324) on June 16, 2022.81
Additional notices were published in the following newspapers: San Diego Union-Tribune (June 17,
18, and 19), English only; Frontera (June 17,18, and 19), Spanish only; and Imperial Beach Eagle
and Times (June 22 online; June 23 print), English only. EPA and USIBWC also distributed physical
and electronic fliers in both English and Spanish to Native American and tribal representatives,
local businesses, and private residences near the Proposed Action as well as to various
governmental representatives.
EPA and USIBWC hosted two virtual public comment meetings open to any interested party during
the 45-day period, which took place on July 19, 2022 at 6:30 pm PDT and July 20, 2022 at 2 pm
PDT. The meeting materials were presented in a bilingual written format (English/Spanish) and
81 https://ceqanet.opr.ca.gov/2022060324
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Public and Interagency Coordination
audio was made available during the meeting with simultaneous Spanish interpretation services.
Closed captioning was also available to participants during the meeting. A recording of the first
public comment meeting was made available on the EPA Tijuana River Watershed NEPA
Implementation project website.82 All comments received, both individually during the 45-day
review period and during the virtual public comment meetings, were reviewed by EPA and
USIBWC. Substantive comments were considered in preparation of this Final PEIS and are
appended to or otherwise summarized in Appendix A (Response to Comments on Draft
Programmatic Environmental Impact Statement). Additionally, this Final PEIS includes a summary
that identifies all alternatives, information, and analyses by state, tribal, and local governments and
other public commenters submitted for consideration in developing the Final PEIS in accordance
with 40 CFR§ 1502.17(b)—see Section 7.3.5.3 (Summary of Submitted Alternatives, Information,
and Analyses).
7.3.5.2
Summary of Public Comments
During the 45-day review period for the Draft PEIS, EPA and USIBWC received 38 comments that
had unique content, including 25 emailed comments with 15 unique letters, three form letters, and
seven slight variations of the form letters; eight written comments from the public meetings; and
five spoken comments from the public meetings. In addition to private citizens, the following
organizations and agencies provided comments on the Draft PEIS:
CalEPA
California State Lands Commission
California State Parks
Citizens for Coastal Conservancy
City of Coronado, Office of the Mayor
City of Imperial Beach
City of San Diego
Congress of the United States, Office of
Congressman Juan Vargas
County of San Diego, Land Use and
Environment Group
County of San Diego, Parks and
Recreation
Outdoor Outreach
Port of San Diego
San Diego Audubon Society
San Diego County Board of Supervisors
San Diego County Board of Supervisors,
Office of Vice Chair Nora Vargas
San Diego Regional Water Quality
Control Board
Stop the Poop
Surfrider Foundation
Tijuana River Valley Equestrian
Association
YMCA of San Diego County
EPA and USIBWC have considered and responded to all substantive comments. The responses and
reproductions of all comments are appended to this PEIS—see Appendix A (Response to Comments
on Draft Programmatic Environmental Impact Statement).
82 See https://www.epa.gov/sustainable-water-infrastructure/tijuana-river-watershed-nepa-
implementation.
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7.3.5.3 Summary of Submitted Alternatives, Information, and Analyses
Some of the comments on the Draft PEIS suggested projects to be considered in the PEIS and/or
provided information or analyses for EPA and USIBWC consideration. See Section 2.7.4 (Other
Projects Identified Based on Public Comments on the Draft PEIS) for a summary of alternatives
commenters submitted for consideration during the public comment period. Additional
information about the range of alternatives considered is provided in Sections 2.2 (Proposed Action
and Range of Alternatives Evaluated in This PEIS) and 2.7 (Alternatives Eliminated from Evaluation
in This PEIS).
In accordance with 40 CFR§ 1502.17(b), EPA and USIBWC have appended to this PEIS all
comments received during the comment period and indicated which of those include alternatives,
information, and analyses for the agencies' consideration—see Appendix A (Response to Comments
on Draft Programmatic Environmental Impact Statement). Comments in this appendix that contain
"alternatives," "information," or analyses" are identified under the comment heading "Flag Excerpt
as Containing Submitted Info."
7.3.5.4 Summary of Changes Since the Draft PEIS
Since release of the Draft PEIS, EPA and USIBWC revised this PEIS to account for comments
received on the Draft PEIS, binational negotiations, ongoing consultations, additional analyses, and
minor technical edits. The following bullets identify the sections that EPA and USIBWC substantially
revised or added since the Draft PEIS and the general reasons for the updates:
• Revised to identify the preferred alternative: Sections 1.1 (Background) and 2.6
(Identification of Preferred Alternative and Environmentally Preferable Alternative).
• Revised and/or added to reflect the EPA and CONAGUA SOI and/or the IBWC Treaty Minute
No. 328 and its relationship to the Proposed Action: Sections 1.1 (Background), 2.5.2.3
(Project G: New SABTP), 2.5.2.4 (Project H: Tijuana WWTP Treated Effluent Reuse), 2.8
(Funding Sources and Binational Agreement), 2.9 (Related Projects), and 4.21.5 (Cumulative
Effects).
• Revised to address public comments on the Draft PEIS: Sections 2.2 (Proposed Action and
Range of Alternatives Evaluated in This PEIS), 2.4 (Alternative 1: Core Projects), 2.4.1.2
(Project B: Tijuana Canyon Flows to ITP), 2.5 (Alternative 2: Core and Supplemental
Projects), 2.5.2.3 (Project G: New SABTP), 2.6 (Identification of Preferred Alternative and
Environmentally Preferable Alternative), 3.1.1.2 (Tijuana River in U.S. (Downstream of U.S.-
Mexico Border)), 3.2.2 (Marine Water Quality), 3.13 (Solid and Hazardous Waste), 3.16
(Public Health and Safety), 4.1 (Freshwater and Estuarine Resources), and 5 (Mitigation
Measures and Performance Monitoring).
• Revised and/or added to summarize and discuss the public review process and comments
received on the Draft PEIS: Sections 2.7.4 (Other Projects Identified Based on Public
Comments on the Draft PEIS) and 7.3.5 (Public Review of Draft PEIS).
• Revised to reflect updates regarding consultation and/or coordination statuses and
findings: Sections 3.5 (Marine Biological Resources), 3.9 (Land Use), 4.4 (Inland Biological
Resources), 4.5 (Marine Biological Resources), 4.7 (Cultural Resources), 4.10 (Coastal
Zone), 5 (Mitigation Measures and Performance Monitoring), 7.2.1 (Endangered Species Act
Section 7 Consultation), 7.2.2 (Magnuson-Stevens Fishery Conservation and Management
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Act Consultation (Essential Fish Habitat)), 7.2.3 (National Historic Preservation Act Section
106 Consultation), and 7.2.4 (Government-to-Government Consultation with Native
American Tribes).
• Added to discuss mechanisms that would be used to monitor the effectiveness of
infrastructure improvements implemented under the Proposed Action: Section 5.3
(Performance Monitoring of Project Effectiveness).
• Revised based on internal EPA and USIBWC review, including addition of new measures to
ensure the PEIS reflects sufficient mitigation of air quality impacts: Table 5-2 (Summary of
Mitigation Measures by Alternative and Project).
• Received other miscellaneous technical revisions: Abstract, Executive Summary,
Appendices, and Sections 1.3.2 (Impacts of Contaminated Transboundary Flows), 2.5.2.6
(Project J: Trash Boom(s)), 2.7.1 (Projects and Sub-projects from EPA's Initial Set of 10
Projects), 3.1.3 (Stormwater Management), 3.1.4 (Groundwater and Drinking Water), 3.3
(Floodplains), 3.12 (Climate), 4.2 (Marine Waters), 4.12 (Climate), 4.13 (Solid and
Hazardous Waste), 4.16 (Public Health and Safety), 4.18 (Noise), 4.21.5 (Cumulative
Effects), 6.1.1 (Summary of Federal Cross-Cutting Authorities), 6.1.2 (Freshwater and
Estuarine Resources), 6.1.5 (Inland Biological Resources), 6.1.6 (Marine Biological
Resources), 6.1.9 (Coastal Zone), 6.1.11 (Climate), and 7.3.1 (Public Information Meetings).
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List of Preparers and Reviewers
8. LIST OF PREPARERS AND REVIEWERS
The individuals listed in Table 8-1 contributed to the preparation of this document
Table 8-1. List of Preparers and Reviewers
Affiliation
Name
Relevant Experience
Preparers
ERG
Patrick Goodwin
B.A. Environmental Science; 20 years of experience in NEPA and
(Project Manager)
environmental planning and compliance
Helen Anthony
B.S. Environmental Technology and Management; 8 years of experience in
water quality planning and compliance
Eric Bell
B.S. Mechanical Engineering, M.S. and Ph.D. Civil and Environmental
Engineering; 8 years of experience in sustainability engineering and climate
change mitigation
Brittany Bondi
B.S. Environmental Studies, M.S. Environment and Resources; 2 years of
experience in NEPA and environmental and natural resource studies and
documentation
Allison DenBleyker
B.S. Civil Engineering, M.S. Environmental and Water Resources
Engineering; 15 years of experience in air pollution emission inventories
from mobile sources
Theresa Docal
B.S. Environmental Science and Policy; 3 years of experience in NEPA and
environmental and natural resource studies and documentation
Blake Fox
B.S. Environmental Science; 9 years of experience in NEPA and
environmental and natural resource studies and documentation
Kathleen Onorevole
B.A. Environmental Biology, M.S. Marine Science; 8 years of experience in
sustainability and water quality planning and monitoring
Bob Sidner
B.S. Chemical Engineering; 22 years of experience in air pollution
permitting and compliance assessments, air emissions estimation, air
pollution control planning, and process engineering evaluations
ASM Affiliates
Jimmy Daniels
B.A., M.A., and Ph.D. (candidate) Anthropology; 15 years of experience in
archaeology and cultural resource management
PG
James Hollibaugh
B.S. Mechanical Engineering; 16 years of experience in environmental
Environmental
compliance
Esa Crumb
B.S. Molecular, Cellular, and Developmental Biology, M.S. Ecology and
Systematic Biology, PWS #3842; 14 years of experience in environmental
compliance and natural resource assessment, monitoring, technical
studies, and documentation
Matt Reusswig
B.S. Environmental Science, B.S.E. Civil and Environmental Engineering,
M.S. Environmental Engineering and Science; 12 years of experience in
NPDES permits development, wastewater engineering, and modeling
Andrew Rimelman
B.S. Chemical Engineering; 3 years of experience in wastewater
engineering and NPDES permitting
Jason Rose
B.S. Geoenvironmental Engineering; M.S. Hydrological Science and
Engineering; 25 years of experience in hydrogeology, environmental
remediation and compliance
Kevin Stockton
B.S. Astrophysics; 8 years of experience in stormwater/wastewater
infrastructure planning, assessment, and compliance
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Table 8-1. List of Preparers and Reviewers
Affiliation
Name
Relevant Experience
Stillwater
Sciences
Wendy Katagi
B.A. Social Ecology; Certified Environmental Professional, 32 years of
experience in watershed planning/implementation of multi-benefit
restoration and species recovery programs
Holly Burger
B.S. Biology; 20 years of experience in aquatic and terrestrial biology and
environmental planning and compliance
Lucy Barraza
B.S. Evolution and Ecology; 17 years of experience in CEQA and NEPA,
environmental planning and compliance
Matt Drenner
B.A. Biology, M.S. Environmental Sciences, Ph.D. Forestry; 13 years of
experience evaluating fish populations and habitat and extensive research
examining the behavior and physiology offish species
Nicole Jurjavcic
B.A. Biological Sciences (Ecology and Evolution), M.S. Ecology; 25 years of
experience in botanical surveys, habitat assessments, and environmental
planning and compliance
Marissa Montjoy
B.A. Environmental Sciences; 5 years of experience in wildlife construction
monitoring and targeted wildlife surveys
Margie Pfeffer
B.A. Environmental Science; 5 years of experience in botanical surveys and
habitat restoration
Tenera
Environmental
Joe Phelan
B.S. Marine and Environmental Science, Ph.D. Marine Biology; 15 years of
experience in marine environmental planning
Reviewers
EPA Region 9
Elizabeth Borowiec
B.A. Political Science and Communications, M.S. Community and Regional
Planning; 30 years of experience in water resources management
Tom Konner
B.S. Geology, M.F.A. Creative Writing, M.S. Civil and Environmental
Engineering; 20 years of experience in water resources engineering
Monica Moran
B.S. Environmental and Ecological Engineering; 2 years of experience in
water resources engineering
Steven Smith
B.A. Economics, M.S. Environmental Studies; 22 years of experience in
environmental planning for water and wastewater projects
Mimi Soo-Hoo
B.A. Geography, M.S. Environmental Science and Management; 9 years of
experience in water resources management
EPA
Headquarters
Ami Cobb
B.S. and M.S. Civil and Environmental Engineering; 5 years of experience in
water resources engineering
Jessica Glenn
B.S. Civil and Environmental Engineering; 9 years of experience in rural and
urban water and wastewater infrastructure engineering
USIBWC
Gilbert Anaya
B.S. Microbiology, M.S. Environmental Science; 33 years of experience in
water and environmental resources
Kelly Blough
B.A. Geology; 28 years of experience in environmental management
Mark Howe
B.A. Anthropology, M.A. History; 25 years of experience in cultural
resources
Elizabeth
Verdecchia
B.A. Environmental Science and Engineering, M.A.G. Applied Geography;
21 years of experience in environmental science
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References Cited
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