ENVIRONMENTAL DATA STATEMENT SAN ONOFRE TO ENCINA 230 KV TRANSMISSION LINE PREPARED FOR: SAN DIEGO GAS & ELECTRIC COMPANY 101 ASH STREET SAN DIEGO, CALIFORNIA 92101 PREPARED BY: WESTEC SERVICES, INC. 1520 STATE STREET, SUITE 240 SAN DIEGO, CALIFORNIA 92101 AUGUST 1978 TABLE OF CONTENTS Section Title Page I INTRODUCTION 1 1.1 General 1 1.2 Scope of the Environmental Data 2 Statement (EDS) 1.3 Need for the Project 2 1.4 Preparation Staff 3 1.5 Certification 3 II PROJECT DESCRIPTION 5 2.1 Location 5 2.2 Objectives S 2.3 Project Characteristics 8 2.4 Construction Methods 15 2.5 Operation and Maintenance 16 2.6 Environmental Criteria 16 III EXISTING CONDITIONS 17 3.1 Land Resources 17 3.1.1 Overview 17 3.1.2 Topography 18 3.1.3 Geology and Geologic Structure 19 3.1.4 Soils 20 3.1.5 Geologic Hazards 20 3.1.6 Soil Erosion 21 3.1.7 Volcanic Activity 2 TABLE OF CONTENTS (Continued) Section Title Page 3.1.8 Areal Land Subsidence 22. 3.1.9 Mineral Resources 22 3.1.10 Seismicity 22 3.2 Vegetation, Wildlife and Habitat 24 3.2.1 Vegetation 24 3.2.2 Wildlife and Habitat 27 3.2.3 High Interest Species 29 3.3 Air Quality 35 3.3.1 Meteorology 35 3.3.2 Air Quality 35 3.3.3 Electrical Phenomena 35 3.4 Hydrology 37 3.4.1 Water Quality 38 .3.5 Land Use 38 3.5.1 . Overview 38 3.5.2 Construction Areas 40 3.6 Socio-Economic Factors 42 3.7 Cultural Resources 42 3.7.1 Archaeology 3.7.2 Paleontology 61 3.8 Aesthetics 62 3.9 Noise 6.) TABLE OF CONTENTS (Continued) Section Title Page IV ENVIRONMENTAL ANALYSIS 65 4.1 Land -Resources 65 4.1.1 Overview 65 4.1.2 Landform Alteration 66 4.1.3 Erosion Potential 66 4.1.4 Landslide Potential 66 4.1.5 Flooding 67 4.2 Biological Resources 67 4.3 Air Quality 68 4.3.1 Meteorology 68 4.3.2 Air Quality 69 4.3.3 Electrical Phenomena 69 4.4 Hydrology 76 4.4.1 Surface Water 76 4.4.2 Groundwater 78 4.4.3 Water Quality 78 41.5 Land Use 78 4.5.1 Overview 78 4.5.2 . Construction Areas 79 4.6 Socio-Economic Impacts 80 4.7 Cultural Resources 81 4.7.1 Archaeology 81 4.7.2 Paleontology 4.8 Aesthetics 82 TABLE OF CONTENTS (Continued) Section Title Page 4.9 Noise 83 4.10 Safety 89 V MITIGATION MEASURES 90 5.1 Land Resources 90 5.1.1 Overview 90 5.1.2 Landform Alteration 90 5.1.3 Erosion Potential 90 5.1.4 Landslide Potential 90 5.1.5 Flooding 91 5.2 Biological Resources 91 5.3 Air Quality 91 5.3.1 Meteorology 91 5.3.2 Air Quality 92 5.3.3 Electrical Phenomena 92 5.4 Hydrology 95 5.4.1 Surface Water 95 5.4.2 Groundwater 95 5.4.3 Water Quality 95 5.5 Land Use 95 5.6 Socio-Economic Considerations P5 5.7 Cultural Resources 97 5.7.1 Archaeology 07 Paleontology 99 iv TABLE OF CONTENTS (Continued) Section Title Page 5.8 Aesthetics 99 5.9 Noise 99 5.10 Safety 100 VI ALTERNATIVES TO THE PROPOSED ACTION 101 6.1 Introduction 101 6.2 Alternative Routes 101 6.3 Alternative Design 102 6.4 No Project 102 VII UNAVOIDABLE ADVERSE IMPACTS 104 VIII RELATIONSHIP BETWEEN LOCAL SHORT-TERM USES OF MAN'S ENVIRONMENT AND THE MAINTENANCE AND ENHANCEMENT OF LONG-TERM PRODUCTIVITY 105 IX IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS 106 OF RESOURCES X GROWTH-INDUCING IMPACTS OF THE PROPOSED PROJECT 107 XI PERMITS AND AGENCY CONTACTS 108 XII REFERENCES, PERSONS AND ORGANIZATIONS CONSULTED LIST OF FIGURES Number Title Page 2-1 Regional Map 6 2-2 SDGE'S SONGS 2 and 3 Transmission System 2-3 Areas of Construction 11 V LIST OF FIGURES (Continued) Number Title Page 2-4 Existing Structures -- Oceanside Airport 12 2-S R/W Cross Section -- Oceanside Airport 13 2-6 Lattice Tower -- Hub 14 3-1 Trapline Locations 32 3-2 Current Zoning 41 3-3 Archaeological Resources 56 4-1 Calculated Electrostatic Field Strength - Oceanside Airport Segment 77 4-2 Noise Level Contours 88 LIST OF TABLES Number Title Page 2-1 San Onofre-Encina 230 KV Line Data 9 3-1 Ambient Air Quality - Oceanside Station 36 3-2 Archaeological Sites in the Region of Proposed Construction: San Onofre to Encina 230 KV Circuit 48 3-3 Mission Avenue Traffic Noise 64 4-1 Operations Data for Installation of New 84 Structures and Wire Installation 4-2 Equipment Noise Levels 85 4-3 Annual CNEL 87 APPENDICES Letter Title Page A Soils Investigation A-1 B Economic Data B-1 C Archaeologic Background Data C-1 vi APPENDICES (Continued) Letter Title Page D Archaeologic Record Search Data D-1 E Acoustical Analysis E-1 vii SECTION I INTRODUCTION 1.1 GENERAL The Final Environmental Statement (AEC, 1973) for the San Onofre Nuclear Generating Station, Units 2 and 3, identified the need for San Diego Gas & Electric Company (SDG&E) to provide addi tional transmission lines if it was to effectively utilize its share of the additional generating capacity of these new units. This Environmental Data Statement (EDS) was developed to evaluate the environmental effects of the placement and operation of 24 miles of single circuit 230 KV transmission line (of which ap proximately 0.6 miles involve new construction) within the SDG&E system between the San Onofre Nuclear Generating Station (SONGS) and SDGGE's Encina. Substation in Carlsbad. This document identi fies and evaluates potential environmental impacts associated with the placement, construction (where applicable) and operation of the proposed transmission circuit and has been prepared in con formance with the California Environmental Quality Act of 1970 and subsequent environmental legislation. This document has been structured in accordance with the guidelines contained in Rule 17.1 of the "State of California Public Utilities Commission (CPUC) Rules of Practice and Procedure" dated March 23, 1974, and is intended to accompany an application to this Commission for a Certificate of Public Convenience and Necessity under General Order Number 131. Certification by the Commission is required for those portions of the proposed San Onofre to Encina circuit which involve new construction. 1.2 SCOPE OF THE ENVIRONMENTAL DATA STATEMENT (EDS) This EDS presents a systematic evaluation of the potential environmental impacts associated with the proposed project, and considers the impacts of alternatives to the project. Character istics unique to electrical transmission lines have been identi fied, and their effects considered in light of the present and potential environmental setting of the project area and surround ings. It has been prepared as a focused document in accordance with the March 4, 1978 amendments to the California Environmental Quality Act (CEQA). As such, it has considered all potential environmental effects, but has dismissed those felt to be in significant, providing a rationale for such conclusions. Thus, this EDS focuses on those environmental effects which are determined to be of significance. This Draft EDS is not meant to be used as an engineering document. Likewise, it does not relieve the involved agencies of their responsibilities to ensure that engineering documents other wise required for this project are prepared and submitted. 1.3 NEED FOR THE PROJECT The San .Onofre-Encina 230 KV Circuit is required to transmit power from San Onofre Unit 2 to SDG&E's system and to reliably import power from the intertie with Southern California Edison Company during credible outage conditions. Loss of either the San Onofre-Mission or San Onofre-Talega 230 KV circuits would result in a reduction of firm energy import capabilities through the intertie to the SDG&E system. Loss of both of these circuits 2 would completely sever the SDGGE electric transmission system from the rest of the interconnected systems in the western states. This would isolate SDG&E from its share of power generated by San Onofre Nuclear Generating Station, as well as power normally delivered through the intertie from other off-system resources. Increased on-system generation, if available, would be required to replace generation lost as a result of reduced intertie capa bilities. The San Onofre-Encina 230 KV line will also provide addi tional outlet capacity for Encina Unit 5, thereby increasing the reliability of power supply from this generating source. 1.4 PREPARATION STAFF Members of WESTEC Services' professional staff and its consultants contributing to this report are listed below: Ed Kamps; M.S. Business Science, B.A. Electrical Engineering San Diego Acoustics, Inc. (Consultant) Richard L. Carrico; M.A. History, B.A. Anthropology William Eckhardt; B.A. Anthropology Stephen B. Lacy; M.S. Biology Gary Lowe; M.S. Geology Frank A. Kingery; M.S. Geology, Registered Geologist State of California, No. 3352 Fay .0. Round; B.S. Engineering 1.5 CERTIFICATION The environmental information in this EDS has been compiled by the individuals listed above. To the best of our knowledge and 3 belief this information is accurate and correct and reflects our best professional opinion of the direct and indirect environmental impacts associated with the proposed project. Fay 0. Round, Jr. Principal/Project Manager 4 SECTION II PROJECT DESCRIPTION 2.1 LOCATION The route of the existing right-of-way (R/W) involved in this project is shown in Figure 2-1. It extends for about 24 miles from the San Onofre Nuclear Generating Station in Orange County, through Camp Pendleton, areas of unincorporated San Diego County, and portions of the Cities of Oceanside and Carlsbad, finally terminating at the San Diego Gas & Electric Company's Encina Substation located near the Encina Power Plant in Carlsbad.