Addressing seismic issues at Altimira Middle School
During its meeting on Thursday, the Sonoma Valley Unified School District board reviewed three options to address seismic deficiencies in nine buildings at Altimira Middle School, including a full retrofit that would cost an estimated $9.3 million.
“The issue is not an emergency,” said Josh Jackson said, a senior associate who presented the options for the consulting firm Perkins Eastman. “The buildings are not at risk of imminent collapse, but there is some urgency to this.”
While preparing the school district’s Facilities Master Plan, Perkins Eastman stated in January 2023 that several of Altimira’s buildings do not meet earthquake safety standards. The district is advised to either retrofit or demolish the buildings.
“It could be a high priority for the district to address in the coming years. I don’t think actions need to be taken this week, but this is the next thing the district should spend capital investments on,” Jackson said.
Trustee Celeste Winders said that it was a relief to hear that the buildings are safe right now, but that the situation is serious.
“It is very serious in the context that we live in California and earthquakes are part of our lives here and a big consideration in the decisions we make as a community,” she said. “Altimira is a top priority when we have discussion about capital investments in our schools. There is nothing that is a higher priority than Altimira. It needs to be the next capital investment we make.”
Perkins Eastman obtained ratings for the nine buildings at Altimira according to a structural performance scale aligned with The American Society of Civil Engineers Code 41-17. The scale ranges from S-6 (unsafe) to S-1 (suitable for immediate occupancy).
It was determined that in a maximum considered earthquake, which is expected to occur every 700 to 1,300 years, the nine Altimira buildings all have a rating of S-6. For smaller “design-based earthquakes,” which occur every 250 to 600 years, Altimira structures all received a rating of S-5, meaning they would have damaged components and continue to support gravity loads, but retain no margin against collapse.
“I want to clarify that lots of school districts have building that have these ratings,” Jackson said. “This is not great news, but the caveat is that these buildings do not need to stop being used immediately. They are structurally sound, but we would have concerns if the strongest type of earthquake that could potentially occur in this area were to take place.”
Jackson provided details of three possible ways to address the issue.
In one scenario, all students who would normally attend Altimira would instead enroll at Adele Harrison Middle School. Based on the 2022-23 enrollment (396 students; 2023-24 enrollment is 352 students) at Altimira, this would require Adele Harrison to add approximately 36,000 square feet of classroom and lab space for roughly $18 million.
“To be perfectly honest, given that the projected (future) enrollment is lower than the current year, this number could be lower,” Jackson said. “At the same time, there could be other improvements to the site related to infrastructure and circulation, so the cost could be as low as $12 million or up to $25 million.”
Winders said this option presents its own set of problems.
“Adele Harrison is not big enough to provide the level of quality educational spaces for all of the Valley’s middle school students,” she said. “It would require an expansion that also has significant cost attached to it.
“An additional consideration is that the campus is on Broadway, next to the high school, where traffic is already a heavy concern.”
Trustee John Kelly added, “Sonoma Valley Unified School District does not have the necessary funds to pursue that type of construction, given the money available for capital projects.”
Another possibility would be to retrofit only the six buildings that house students — four classroom buildings, a gym and a library — and aim for an S-3 standard, in which structure would have damaged components after an earthquake but retain a safe margin against the onset of partial or total collapse.
In this scenario, seismic improvements would cost an estimated $4.5 million and additional funds could be used to pursue modest classroom modernizations while the working is being done.
“We would be very confident that there would be no injuries in the buildings, but they may not be immediately usable in the wake of an earthquake,” Jackson said. “It would be totally reasonable for the district to say, ‘We don’t want to spend money on reinforcing buildings that students don’t spend time in.’”