Petaluma to assess 15 public buildings for earthquake safety, including historic library

The earthquake and aftershock that rattled much of the North Bay last week was a reminder to be prepared for the next big temblor — and area municipalities are taking note.

Earthquakes with an epicenter inside Petaluma city limits occur frequently, according to Robert-Michael de Groot with the U.S. Geological Survey in Pasadena, but none are significant enough to cause damage or even notice. That doesn’t mean Petaluma is in the clear, especially considering danger lurking from local fault lines, including the Rodgers Creek Fault that runs partially along Sonoma Mountain, east of the city.

In the days following the 4.4 magnitude quake, its epicenter located about 2 miles northeast of central Santa Rosa, and the subsequent 4.3 magnitude aftershock Sept. 12, municipalities across Sonoma County examined area infrastructure for damage. The only significant destruction was said to have occurred to some homes in a Larkfield neighborhood about 5 miles from the quake’s center.

The temblor prompted many to also consider the potential for future, larger seismic events.

The city of Petaluma hopes to move forward with a study to assess the feasibility and cost of adding retrofits to several public buildings for better safety in case of a sizable quake. The study will be funded through a $499,000 grant the city received this summer from the California Department of Housing and Community Development.

“Obviously we want to make sure all of our buildings are safe to be in,” said Patrick Carter, assistant to the Petaluma city manager.

The city’s assessment list is comprised of 15 structures, not in any specific order:

• Community Center — 20 N. McDowell Blvd.
• Police Station — 969 Petaluma Blvd. N.
• Fire Station No. 1 — 198 E. D St.
• Fire Station No. 2 — 1001 N. McDowell Blvd.
• Fire Station No. 3 — 831 S. McDowell Blvd.
• Senior Center — 211 Novak Drive
• Teen Center — 150 Fairgrounds Drive
• Cavanaugh Center — 426 Eighth St.
• City Hall — 11 English St.
• Water Field Office — 202 N. McDowell Blvd.
• Corporation Yard — 840 Hopper St.
• Municipal Airport — 601 Sky Ranch Drive
• Transit Center — 555 N. McDowell Blvd.
• Petaluma Historical Library & Museum — 20 Fourth St.
• Petaluma water distribution system and tanks

“There is no imminent threat that we’re aware of,” Carter said about the buildings on the list.

The city will contract with a third party to perform the assessments of each structure, but that doesn’t mean each one will need improvements.

For instance, the Water Field Office, built in 2005, has a better chance of being up to seismic safety standards than the Petaluma Historical Library & Museum, which is over 115 years old.

The museum has multiple seismic vulnerabilities that in 2017 were assessed and flagged as needing retrofitting. Of particular concern is the structure’s ceiling, which includes a free-standing stained-glass dome, and other dated infrastructure that’s been on the museum’s radar for years.

Previous assessments put the cost of retrofitting the museum’s building at $3.6 million.

Petaluma Public Works and the city are currently working on outsourcing the assessment job. The organizations have yet to put out requests for proposal, but the selection process will take about a month once the applications are received, according to Carter.

The application window typically lasts three to four weeks, with the hope of getting three solid proposals.

The city has three years to use the grant funds, but a timeline to start the process is currently unknown, Carter said. While it’s hoped the process will start soon, the city may not currently have the resources to allocate toward the project.

“A lot of this is based on staffing availability,” Carter said. “We have a lot of irons in the fire.”

Once the seismic retrofit studies for each building are collected, the city will need to seek additional funding to execute the retrofitting plans. That financing would ideally come from another state grant, Carter said.

Contact the reporter Rebecca Wolff at rebecca.wolff@sonomanews.com.