PG&E Co. was ordered by the California Public Utilities Commission in San Francisco Tuesday to pay a $400,000 fine for a toppled transmission tower that caused a massive blackout in Monterey County in 2015.
More than 55,000 people lost power when the newly installed transmission tower north of PG&E’s Moss Landing substation fell over and took high-voltage transmission lines down with it on Oct. 18, 2015.
The customers who lost power were in Sand City, Seaside, Pacific Grove, Carmel-by-the-Sea, Monterey and the surrounding area beginning at 7 a.m. that day. About half had power restored within seven hours, but others lacked electricity for 17 hours.
The citation issued by the PUC Safety and Enforcement Division said utility workers used an incorrect angle when they installed the four concrete footings of the tower on Sept. 9, 2015.
That “resulted in a low safety factor and caused the tower to fail and fall to the ground” on Oct. 18, the citation said. The tower was put into operation on Oct. 11.
The citation said, “PG&E’s employees discovered the misalignment on September 9, 2015, and proceeded with constructing the tower without correcting the misalignment.” The citation is for installing the tower improperly and seven days of operating it with a below-minimum safety factor.
Since then, according to the citation, PG&E hired an outside engineering company, updated its construction standards and procedures and tested all towers installed within the previous two years.
PG&E has 30 days either to pay the citation or to appeal it to a PUC administrative law judge.
In a statement, the utility said, “We are reviewing” the citation, and did not say whether it plans to appeal.
Spokesman Matt Nauman said, “As we shared publicly after this incident, the tower footings were not properly installed and that led to the tower failure.” “Since then, we have inspected all recently constructed towers and found that they were installed correctly with no steel deformation or cracking,” he said.
Bauamman said steps recommended by the engineering firm included a new tower stub angle verification process, additional training and the use of stronger steel, and “have all been implemented.”