City News
Updates on Mold Testing and Remediation Planning at Sebastopol Library
June 15, 2026, City News
The City of Sebastopol and the Sonoma County Library are providing an update on the status of the Sebastopol Regional Library following environmental testing and initial exploratory work inside the building.
The Library was proactively closed to the public on Thursday June 4 after a staff member observed peeling wallpaper in the Staff Work Room and Teen Reading Area. Library staff opened sections of the walls in the affected areas after investigating peeling and other signs of moisture intrusion. During that process, mold was discovered within the wall cavities. To assess the situation, specialists, including a certified environmental testing firm and laboratory, were retained to conduct mold and indoor air quality testing on June 5. The results of that testing are being used to guide the appropriate remediation and repair efforts.
A quote from Library staff that was reported in local media last week mistakenly stated that the type of mold observed in the building had not yet been identified. The mold observed within the opened wall cavities is Stachybotrys sp., commonly referred to as black mold. Information about mold in buildings and their impact on health may be found on the websites of the CDC and the California Department of Public Health.
Environmental testing also confirmed that airborne mold was not detected in common areas of the library. Elevated airborne mold levels were identified only in the two rooms where wall assemblies had been opened: the Staff Work Room/Office Area and the Teen Reading Area. Based on the information available, the elevated airborne mold levels in those rooms were likely related to the disturbance of mold-impacted materials during exploratory wall openings. Because Library staff opened the walls in those rooms before any environmental testing was conducted, the City cannot make a definitive determination about environmental conditions that may have existed prior to that work.
As a precaution, the city’s commercial cleaning contractor ServPro established containment in the affected rooms and installed HEPA air scrubbers to help maintain air quality and reduce the potential spread of airborne particulate matter. The library remains closed to the public while the City continues to evaluate the building and determine the appropriate next steps.
Based on non-invasive moisture testing, wall assemblies throughout the building have been found to contain elevated moisture levels, which means mold growth may be present within additional concealed wall cavities. The current demolition work in the Teen Room and Staff Room is intended to evaluate the extent of damage to the building’s structural wood framing and to help develop a more accurate scope of work and cost estimate for remediation of the full facility.
The City has asked the contractor to pause once this initial phase of work is complete and to treat the work performed to date as Phase I. Much of this initial work has focused on addressing contamination associated with the exploratory wall openings and assessing conditions in the two affected rooms.
A future Phase II would likely involve opening walls throughout the building and performing more comprehensive mold remediation. Given the substantial anticipated cost, this matter is anticipated for discussion at the July 7 City Council meeting. At that time, the City Council will discuss next steps. Staff will provide additional information and recommendations as they become available.
Moving forward, the City of Sebastopol will serve as the point of contact for communications related to remediation and repair of the library building, which the City owns. A webpage on the City of Sebastopol website is being developed as a resource for the public. Updates will also be posted to the City’s social media outlets. The Sonoma County Library will provide updates regarding library services.