A.6.1   Introduction

This section addresses the key aspects of the proposed Project that relate to protecting public safety during the construction and operational phases of the Project, including the converter stations and onshore and offshore HVDC and HVAC cables. Safety precautions and emergency systems would be implemented as part of the proposed Project to ensure safe and reliable operation of Project facilities.

A.6.2   Construction Phase

A.6.2.1   Converter Stations/Laydown Areas

The construction schedule for the proposed converter stations, including utilization of nearby laydown areas, is expected to require about 20 months (excluding demolition of existing structures). Construction activities at the converter station sites would include: demolition of existing structures on the converter station sites; remediation of any contamination (based on the results of Phase I and II Environmental Site Assessments and subsequent regulatory agency-approved remediation plans, as applicable, with an expected duration of 3 to 6 months); grading, excavation, and site preparation activities; and construction of the converter station facilities. All of these activities would involve truck traffic and heavy equipment operations. The converter station sites and associated laydown areas would be fenced to prevent unauthorized access and to protect the public from onsite activities. In addition, security personnel would protect the construction sites during non-work hours.

A.6.2.2   Onshore Cable Installation

The relatively short sections of onshore HVAC and HVDC cable would normally be installed via below-ground trenching. All pertinent Occupational Health and Safety (OSHA) standards required for all construction operations would be followed. In addition, any segments of trench left open during non-work hours would be secured to protect the public and vehicular traffic, as applicable. The bore pit locations near the shoreline (and other locations using HDD or comparable technology, as applicable) for the proposed HDD operations would also be shored and fenced to protect the public.

A.6.2.3   Offshore Cable Installation

Installation of the offshore portion of the transmission cables would involve use of the cable laying ship (Giulio Verne) and Hydroplow in deep water areas, and the cable laying barge (with tugboats) and the Hydroplow in shallow water areas (between Suisun Bay and Pittsburg and probably across Pinole Shoals). The offshore cable laying operation is expected to require approximately 4 to 5 months and would occur 24 hours a day, 7 days per week. In order to avoid potential conflicts with ship traffic (commercial, military, fishing, and recreational) and navigation hazards, the U.S. Coast Guard would be notified and kept abreast of the cable laying plans and progress in the bay and a San Francisco Bar Pilots representative would be onboard the cable laying ship at all times. The Coast Guard would issue a Notice to Mariners based on the information supplied by the Project Proponent/Prysmian in advance of the commencement of the offshore cable laying operation. In addition, the cable laying ship/barge and attendant vessels, as applicable, would be well lit and would be equipped with state of the art communication and navigation equipment and radar to ensure safety.

A.6.3   Operational Phase

During the operational phase, the potential exists for electric shock and electric and magnetic fields (EMF) exposure to workers and the public. The design of the proposed Project would protect the public from direct access to all components. The HVDC and HVAC cable would be buried underwater and under sediment or protective mattresses in the submarine portions, and in underground trenches (or on aboveground transmission poles) in the onshore portions of the proposed route. Warning marker tapes and a layer of concrete slab would protect against accidental contact due to construction or unauthorized digging in the underground land-based portions.

At each terminus of the proposed route, the cables would transition from the trench and be terminated within a secured area of the converter stations and PG&E substations, accessible only to trained, authorized personnel. Fencing and/or an enclosure wall would restrict vehicular access. Converter stations and all associated equipment would be contained within an enclosed area with a pass key-operated security gate. Additional security measures would include surveillance cameras and intrusion alarms.

The proposed state of the art communication facilities, including the fiber optic cable portion of the cable system, between the 2 converter stations would allow for real time, instantaneous monitoring of the overall system, and the ability to immediately identify any potential malfunctions. In the unlikely event that the HVDC cable was compromised, the system would shut down instantaneously (milliseconds) thereby preventing electrical shock.

The converter station designs would prevent unacceptable electric and magnetic emissions from the sites thereby protecting the public. The HVDC cable has very low electric and magnetic field values by design and both the HVDC and the short segments of HVAC cables would be installed to achieve minimum electric and magnetic field levels in public areas.

The programs to be implemented to protect worker health and safety would also benefit public safety. Facility design would include redundancy and controls and monitoring systems to minimize the potential for upset conditions. Potential public health impacts associated with facilities operation would be mitigated by development and implementation of Emergency Response Plans; a Spill Prevention, Control, and Countermeasures Plan; Containment Structures; safety programs; and employee training.

The converter stations would have onsite fire protection systems (including emergency backup systems) and would be supported by the local fire protection services. During the detailed design of the proposed Project, potential fire protection designs and systems would be reviewed with local agencies to finalize design details.

In general, the fire protection system would consist of automatic detection and firefighting equipment. The fire detection-control panel would be located in the control room and connected to the control and protection system for remote actuation. The fire alarm would be initiated automatically by smoke, heat, or flame detectors, or manually by push button. A combination of detectors would be used including infrared and ultraviolet detectors, ionization and optical smoke detectors, and rate-of-rise temperature-sensitive detectors, depending on the equipment and/or space being monitored.

Audible alarms and flashing lights would be activated in the event of an incident. The equipment or area where the alarm was triggered would be indicated on the control panel. The firefighting equipment would initiate automatically, using water or an appropriate gas-based extinguishing agent.

Fire detection and automatic firefighting equipment would be connected to a power supply within the fire-detection control panel, which would be connected to the mains via a power supply/battery charger unit with an internal battery. A pump house would be included within the facility with 2 diesel-driven firewater pumps.

Auxiliary power in the event of a power outage would be supplied by an emergency generator (diesel powered).

A.6.4   Waste Management

The proposed Project would generate a variety of wastes during construction and operations. Refer to Section 4.14, Hazardous Materials Handling and Waste Management, for more information. These wastes would include replaceable parts, rags, and other waste materials and chemicals produced from maintenance activities, equipment fluids, and waste oil.

A.6.4.1   Construction Wastes

Inert solid wastes resulting from construction activities may include lumber, excess concrete, metal and scrap, and empty non-hazardous containers. Management of these wastes would be the responsibility of the construction contractor(s). Typical management practices required for contractor waste include recycling when possible, proper storage of waste and debris to prevent wind dispersion, and weekly pickup of wastes for disposal at local Class III landfills. The total amount of solid waste generated by construction activities is expected to be similar to that for normal commercial construction.

A.6.4.2   Operations Wastes

Inert solid waste generated at the converter stations during operation would be predominantly office wastes and routine maintenance wastes such as scrap metal, wood, and plastic from surplus and deactivated equipment, and parts. Scrap materials such as paper, packing materials, glass, metal, and plastic will be segregated and managed for recycling. Non-recyclable inert wastes will be stored in covered trash bins in accordance with local ordinances and picked up by an authorized local trash hauler on a regular basis for transport and disposal in suitable landfill areas. Skim oil collected from equipment drains and other liquids from equipment would be transported by an authorized carrier to a certified recycling facility.

A.6.5   Chemical Management

The chemicals to be used, handled, or stored at the converter stations during operation are listed in Section 4.14, Hazardous Materials Handling and Waste Management. The storage, use, and handling of these materials would be in accordance with applicable laws, ordinances, regulations, and standards and would include:

Periodic inspections would ensure that all containers were secure and properly marked.

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