Hosmer House basement shows elevated mold spores; facilities director reports remediation and pending retesting

Town facilities director Sandra Durander told the Sudbury Historical Commission on Sept. 17 that follow-up testing found elevated mold spores in the Hosmer House basement after visible mold was discovered in a second-floor storage room in 2023. Durander said the art-storage room and most other interior spaces have low spore counts but the basement has experienced elevated levels at times.

Durander described steps taken since the initial discovery: contractors opened affected walls, HEPA vacuumed and cleaned artwork carefully, the house underwent industrial cleaning, two larger dehumidifiers were installed in the basement, and oversized HEPA filtration was added throughout the property. "The basement did have elevated mold spores," Durander said, and the consultant recommended continued dehumidification and follow-up testing after cooler, less humid weather.

Durander said inspectors returned to the site and took fresh air samples that morning; she expected results by the end of the week or early next week and told commissioners she anticipated the levels would drop with continued dehumidification. The facilities team also offered to visually inspect holiday decorations and other stored inventory for visible mold and report back to docents.

Docent Maureen Hines and others expressed concern because many volunteers are older adults. Hines asked whether the kitchen and other areas below the storage room were tested; Durander said the testing protocol covered each floor and areas of concern and that no other indoor air-quality contamination was found. Durander said she would share the lab results with the commission when available.

Next steps: Durander will provide the retest results to the commission and confirm whether the house is safe for docents and public events. The commission is holding open-house planning contingent on acceptable retest results.