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    1. Earthmoving

    Napa Valley River Gas Pipeline Under Construction

    Oct. 16, 2024
    A new 26-inch-diameter pipe will tie into the existing natural gas line network and allow for inline inspections.
    ID 14885808 © Sergei Ryjkov | Dreamstime.com
    Gas Pipeline Construction

    By: Barry Eberling
    Source: Napa Valley Register, California

    Land along Highway 29 in the rural Carneros/Stanly Lane area looks like a long and narrow construction zone, with heavy equipment and large pipes stretching on and on.

    Pacific Gas & Electric Co. is at work south of the city of Napa near the Butler Bridge. The utility company is replacing a natural gas line that runs beneath the Napa River to allow for new inline inspection methods.

    “It is safety-driven and will allow PG&E to pinpoint potential threats to address on our pipeline,” Jeff Smith, a PG&E spokesperson, said in an email. “It will provide data/information that serves Napa and the surrounding area.”

    Workers are putting in a 26-inch-diameter pipe that will tie into the existing natural gas line network on each side of the river. Then, when the new pipe is working, PG&E will remove the old pipe, according to the project’s 2023 environmental report.

    Highway 29 drivers are getting glimpses of the action as they speed by. The project is hard to miss, given more than a half-mile of new pipe is involved.

    The trick is installing the pipe without digging up the riverbed. Workers will use horizontal directional drilling—drilling into dry ground in an arc that passes 60 feet under the river. Then the pipe is to be pulled through the borehole.

    When the new pipe is working, the old pipe will be decommissioned and the segment under the river removed.

    “No gas service or public road interruptions are expected,” Smith said.

    A sign near the river has long alerted people to the old natural gas pipeline, which is actually three 8-inch-diameter pipes. It reads: “Warning, do not anchor or dredge, gas pipeline crossing.”

    A barge crane will remove the old pipe from the river by connecting to the end of the buried pipeline, which will be excavated by divers. The crane will lift the pipe vertically out the riverbed, an environmental report said.

    The old pipe is buried less than a foot to 17 feet deep under the riverbanks and riverbed. Excavation in the river, when necessary, will be done with a submersible dredging pump, the study said.

    When the project is finished, the barge will be towed to a local boat landing. There, pipe sections will be loaded onto trucks to be taken to a recycling or disposal facility, according to the environmental report.

    Some segments of old pipes away from the river are to be left in place. They will be filled with cement slurry and capped, the environmental study said.

    Work is to continue through the spring of 2025, according to Smith.

    PG&E has done major natural gas pipeline replacement and upgrading work in the area in previous years. The utility announced in 2020 that it would replace most of a 1930-era transmission line from near Stanly Lane up the Napa Valley to north of St. Helena, work that has since been done.

    Smith said the latest Napa River project is part of a larger project in Napa and Sonoma counties. He wouldn’t say how much the Napa River project costs.

    (c)2024 Napa Valley Register, Calif.
    Visit Napa Valley Register, Calif. at www.napavalleyregister.com.
    Distributed by Tribune Content Agency, LLC.