Addressing seismic issues at Altimira Middle School

“The buildings are not at risk of imminent collapse, but there is some urgency to this,” said Josh Jackson of Perkins-Eastman consulting firm regarding seismic problems at nine structures 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.

Option 1

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.”

Option 2

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.’”

Kelly opined that rather than settling for the S-3 standard, Altimira buildings should meet the highest possible safety standards for students, teachers, staff and community members.

Option 3

The third scenario would be to provide a full retrofit in accordance with the S-1 standard, in which structures remain safe to occupy after an earthquake and retain their pre-earthquake strength and stiffness. This is the standard required by the Division of the State Architect in California for new school construction or a mandatory retrofit.

“This rating indicates that a building is immediately ‘occupyable’ after a seismic event,” Jackson said. “We would anticipate no damage and that the building could be a place of refuge where people could go in the event of an earthquake.”

All six Altimira buildings that house students — as well as the administration building, storage/restrooms structure and mechanical building — would be retrofitted for an estimated $9.3 million.

“This would take all buildings to the S-1 standard, a very high standard,” Jackson said.

Winders noted that S-1 is cost effective and could ensure the school becomes an evacuation site in the event of an emergency.

“Unlike the city of Sonoma, in the Springs we do not have many safe and large places to evacuate the community in the event of a large-scale disaster,” she said. “Altimira is such a place if it were to receive the needed retrofitting.”

Kelly shared concerns about costs, but said the district’s Fund 21, which currently has $24.9 million, can provide the necessary amount of money for the project.

The next steps could be to complete a more in-depth cost analysis and establish an estimated timeline.

Jackson said that the project would take several years.

“I want to be very clear that the types of improvement we’re talking about — to foundations, and roof and wall connections — are potentially long-term projects that would need to be phased in over a period of years, he said. “It would also be really important to think about the impact on school programs. It may be possible to do some work while a site is occupied, but that would need to be coordinated with school programs.”

Reach the reporter, Dan Johnson, at

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