Terminus of Sylmar Ground Return System Being Replaced

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The mystery barge located in the Pacific Ocean, off Sunset and Pacific Coast Highway, is working on an electrical grounding project.

Mystery Ocean Barge Is an Electrical Project

Pacific Palisades Rotary Club member Jim Hahn wondered about the barge, with cranes, that has been located in Santa Monica Bay, off Gladstone’s.

Other locals have expressed similar concerns, with some residents worried that perhaps the barge has something to do with off-shore oil drilling. Another resident reported that “the barge was going to lift a 50-year wreck off the ocean bottom.”

Actually, it’s the culmination of an important L.A. Department of Water and Power project called the Sylmar Ground Return System. I reported on when I worked at the Palisadian-Post (around 2010—I don’t have access to my stories and my name has been taken off those stories, but if you are a subscriber and feed in “Sylmar Ground Return System” (SGRS), you should be able to read early stories on the subject).

The Los Angeles area receives its power from a direct current in The Dalles, Oregon. Power travels 850 miles to the Sylmar Converter Station in the San Fernando Valley, which was put into operation in 1970.

The purpose was for electricity to function safely in Southern California in case of an overflow of energy during a disruption, such as an earthquake or other disaster. The Pacific Direct Current Intertie (PDCI) transmission line requires a ground return system to safely conduct and dissipate overflows of energy.

The Sylmar Ground Return System serves as a safeguard, which allows the PDCI line to remain operational and to allow time for an electrical problem to be fixed.

The grounding system starts in Sylmar, goes 22.5-miles to near the Kenter Elementary School area (Kenter Canyon Terminal Tower) and then underground for 7.5-miles towards the coast before ending at the Gladstone Vault.

The end is located in a parking lot along the south side of Pacific Coast Highway near its intersection with Sunset Boulevard, at Will Rogers State Beach.

DWP Crews are working at a vault located in the Gladstone parking lot, at PCH and Sunset Boulevard. The replacement of cables that will go into the Pacific Ocean will cost about $114 million.

Initially, the first two segments were also going to be replaced. In a July 27, 2016 document filed with the California Coastal Commission, it was explained “that overhead and underground segments of the SGRS, with maintenance improvements, are adequate to support the continued reliable operation of the PDCI and would not be replaced.”

But, the array of cables located about 50 feet below the ocean revealed physical deficiencies, “including seawater penetration and corrosion of the marine cables, metal fatigue at the point of attachment between the cables and the electrode array vaults, and corrosion of the electrode rods, which threaten the reliability and on-going functionality of the system. In addition, the limited capacity of the existing system limits the flexibility of system operators to respond to and resolve disruptions on PDCI, while the location of the electrode just a mile from shore presents a corrosion threat to onshore metal infrastructure related to the operation of the ground return system.”

This meant that the underwater section of the SGRS had to be replaced. A resolution for the $114 million project went before the L.A. City Council for approval in May 2016. The cost of the project would also be split with Southern California Edison (50 percent) and the cities of Burbank (3.8 percent), Glendale (3.8 percent) and Pasadena (2.3 percent).

The project, which was heard and approved by the Coastal Commission, with conditions, on January 2016, would include: two marine cables and 36 concrete vaults housing 144 electrodes that would be extended off shore from the current electrodes (about two miles) and at a depth of about 100 feet below mean sea level.

The report states that a “variety of vessels and equipment would be needed during installation, including a barge, cable laying vessel, jet plow, tug boats and several smaller support vessels, as well as a large generator, a 30-ton crane to be operated from the barge, and an onshore cable-pulling rig. In addition, several truck trips would be required to deliver equipment and materials to the onshore work site during cable pulling.”

The existing marine electrode and cables currently located at the Gladstone Vault and in the ocean would be abandoned pending the completion of a feasibility study for possible removal.

(To read the 47-page report, visit: documents.coastal.ca.gov/reports/2017/1/f9a-1-2017.pdf.)

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2 Responses to Terminus of Sylmar Ground Return System Being Replaced

  1. Hester Palmquist says:

    Thank you so much, Sue, for tackling this mystery!! My husband and I have been seeing this barge daily from our house in Castellammare and could not imagine why it was there.

    Just last night in a phone conversation with my friend Kim Clary, I suggested we contact you to find out what it was doing there, but some other brilliant person beat me to the punch!!

    Hester Palmquist and Murray Levy

    P.S. We love “Circling the News”!!

  2. Robert H Herzstein says:

    Good coverage, as always.

    I’d like to clarify to curious readers (and as a former Southern California Edison employee) that the LA area does not get most of its power from Oregon. However, the different regional transmission and distribution systems are interconnected to allow power to be transferred as needed to use energy resources more efficiently and to respond to system overloads and failures.

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