Residents living along and near West Napa Street were awakened in the early morning hours on Tuesday with the ominous warning to “shelter in place.”
The notice, coming from telephone alerts or a knock on the door between 2 and 3 a.m., warned of a gas leak in the neighborhood.
A six-block area, from Fifth Street to Second Street West, and West Spain to Perkins Street, was alerted to the break, which occurred when a work crew inadvertently broke through a 3-inch natural gas line, according to the Sonoma Valley Fire and Rescue.
The incident took place on the street at 415 W. Napa St. at about 1:23 a.m., when an Anvil Builders crew digging a 5-foot trench for the ongoing water system replacement project broke through the line.
That came just a week after an Anvil crew had cut through an electrical conduit at Fifth Street West, shutting down the stoplight at that intersection. That conduit had not been marked, according to City of Sonoma Public Works Director Colleen Ferguson; this PG&E line, on the other hand, had been.
“My understanding is that they were looking for the line, and had reached a portion of earth that was undistributed, and had not found it,” said the city’s Construction Manager Jane Rozga. They had about a foot to go to the bottom of the trench they were working on, she said, and had been using a shovel to dig. But when they encountered very hard, undisturbed soil about 4 feet down, they believed they had missed the gas line already.
“The material was hard so they used the mini-excavator rather than a shovel,” said Rozga, and the gas line was severed.
Rozga speculated that the gas line had been drilled in “directionally,” so the soil showed no signs of disturbance.
Deanna Contreras of PG&E confirmed that the gas main had been bored in rather than trenched, due to the hardness of the substrata. She also said the line was deeper than most, which may have caused the workmen to believe the line was not in the marked location.
“The line was 6 feet under the street – 71 inches – which is pretty deep,” said Contreras. “The contractor may not have ever seen a line that deep before, and he may have hit an area of bedrock and thought that he was in the clear.”
Contreras and Rozga agreed that the line was properly marked through the 811 system, the Underground Service Alert network of utility providers. PG&E had been notified by Anvil of the potential dig, and the lines were marked to let crews know of their location. The notification of utilities is required for all construction projects, public and private, through the 811 system.
Contreras pointed out that Friday, Aug. 11 (“8-11”), is National Safe Digging Day, to educate the public about the importance of avoiding gas and other utility lines.
“Anytime a home owner or a city or a contractor is doing any work, call 811 or visit 811express.com, and submit the information of the work you’re doing. It could be planting a tree in your back yard, it could be installing a new fence, it’s required that 811 is called. It alerts a ticket for utilities to come out and mark the area.”
Should you dig it?
“Damaging utility lines can result in repair costs, property damage, service disruptions, personal injury or even death,” said James Wingate, executive director of USA North 811. “Choose safety and contact USA before you dig.”
If you’re planning a dig, file a ticket at 811express.com or call 811.
For more information go to www.pge.com/digsafely or www.usanorth811.org/