Mercer Island City Manager Jessi Bon admitted that the shuttered city hall building makes her incredibly nervous.

The aging structure has been closed since mid-April after asbestos-contaminated broken tiles were discovered in the boiler room, which contains two air-handling units. Extensive testing with environmental safety experts revealed asbestos in some settled dust samples and within two HVAC system filters and flooring during additional sampling, according to a report delivered by Jaime Page, support services manager, at the July 18 hybrid city council meeting. There were no positive tests for airborne asbestos.

With her voice slightly quavering, Bon noted that the city has received a preliminary cost estimate of $10.2 million for removal and replacement of equipment and materials and finishes in order for city staff to re-occupy the building. That cost doesn’t include the abatement process of removal and safe disposal of hazardous materials.

Bon said the city faces a significant problem, and one of its worst-case scenarios arose when experts began examining the HVAC system. The attic poses another problem.

“We can’t even access fully the attic. We did asbestos testing as far as we could and then we stopped because the next round of asbestos testing will likely involve full removal of the ceiling to get to the materials,” said Bon, who led a city hall closure update at the meeting and was joined by Tim Ogden, principal of PBS Engineering and Environmental, and others who are working with the city on the complex situation.

“Given the location of the asbestos in the HVAC system, staff speculate that the contamination may have occurred during a building renovation project in the late 1980s or early 1990s,” reads a city report.

No action was taken at the meeting regarding the long-term destiny of city hall, but it is clear that the building will remain closed for the foreseeable future, said Bon, who will return to council in the early fall with an update and engage in a discussion about a city hall-related policy decision. Council will be on August recess until its next meeting on Sept. 5.

As council and city staffers further delved into the city hall discussion, Bon added, “My gut is telling me those costs will go up as we get into further design and probably even run into a lot of problems once we get into construction. I’m very concerned about that.”

The DCW Cost Management estimate was laid out by Northwest Studio’s Aaron Young, a partner for the architecture and urban design firm that was about to begin assessing the conditions of several city buildings before city hall was closed. From design and permitting to construction and move-in, the entire process could take from 13-17 months plus an abatement period. Northwest Studio partners also evaluated the Mercer Island Police Department’s HVAC system, which is estimated to cost $4.1 million to remove and replace over a 13-to-15-month-plus time frame.

Several city councilmembers chimed in with their views on the scenario, noting that the city shouldn’t spend the $10.2 million on a building that is nearing the end of its life span.

“I think in the big scheme of things, all buildings eventually need replacement. It’s just a matter of how much useful life we can get from the building and what it will lead to one concluding it’s necessary for its replacement,” said councilmember Ted Weinberg. “I think the event of us discovering asbestos has reduced the uncertainty for the council and the public that it may be time to consider a once-in-a-century facilities investment for a city.”

Added councilmember Jake Jacobson: “I have a very difficult time thinking of spending any more money aside from what has to be done to kind of close the chapter here for this building.”

City hall — which includes the council chambers — the municipal court and the police department are all located on the city campus at 9611 SE 36th St. Beginning with city council’s April 18 meeting, all subsequent meetings have been conducted virtually, while municipal court hearings are presently occurring at the Kirkland Municipal Justice Center and other court business taking place in a Fire Station 91 conference room. Elsewhere, copious city staffers are either working remotely or within various city buildings. The police department is currently housed in a Luther Burbank Park building.

“We’re a strong team. We’ve been through some hard situations together and we’re hanging in there,” said Bon, adding that they’ve been patient, flexible and creative along the way.

City Hall was closed on April 17, the same day the city began experiencing a water crisis. On the morning of April 22, city officials lifted the water emergency as levels rose overnight to surpass 20 feet in the tanks.