Update on Mold Concerns in KSC Dorms, Fall 2021

Written by Ralph Stuart, CIH, CCHO
Originally written: December 9, 2021
The previous report can be found here.
Questions about the information below can be directed to ralph.stuart@keene.edu


On December 1, sampling of airborne particles in and around Pondside 3 and One Butler Court was conducted. On December 7, the lab results identified the presence of several molds inside and outside both buildings. These include Stachybotrys, which is associated with moist cellulose building materials.

On December 2, one area of mold growth was reported in Pondside 3, on a bathroom ceiling that was being dripped on from a leaking shower above. This area was sampled and found to be Stachybotrys. The underside of the ceiling was cleaned on December 2 and repainted the next day to contain the mold without disturbing it, until the ceiling can be completely replaced over winter break.

A collection of action steps to identify and address any other potential sources of mold contamination in these dorms has been identified. These will be undertaken over winter break. Another round of airborne sampling will be done before the dorms are fully reoccupied in January.

According to the Environmental Protection Agency and Centers for Disease Control, airborne mold is unlikely to raise health concerns for most people without visible growth. Physical Plant and Custodial Services is able to continue to promptly respond to mold concerns and remediate mold growth as they arise. For this reason, we believe that it is appropriate for people to continue to live in these dorms until a more systematic review can be conducted over break.

The report below provides a technical summary of the work done on this issue since the last update on December 1.

Field Sampling

Airborne dust samples were taken in and around the Pondside 3 and One Butler Court using “mold trap” protocols. These samples were collected by Desmarais Environmental, Inc. and were visually examined by EM Labs PK to identify the types and quantities of the molds found in these areas.

For each dorm, six samples were taken:

  • One outdoors as an environmental control
  • One in the ground floor lobby as a building control
  • Two samples were taken in each of two suites where potential mold concerns had been identified. In Pondside 3, the suites sampled were 120 and 207. In One Butler Court, the suites sampled were 312 and 313.

The lab reports for these samples can be seen here:

The primary finding in these results is that some molds were more numerous indoors than outdoors. There are no governmental standards for what constitutes a safe level of these molds in residential spaces. For this reason, KSC Physical Plant will respond to these results by systematically cleaning and examining both buildings when they are unoccupied over winter break to locate and remediate any mold growths in the building. Specific steps to be taken are described below. Another round of sampling will take place before the dorm is fully reopened in January.

Mold Remediation Due to Shower Leak

On December 2, stains on the ceiling of 111 Pondside 3 were reported. Custodial service was dispatched to clean the mold that morning. That afternoon, Ralph Stuart examined both the bottom and top of the ceiling tile and took surface samples for lab analysis. The lab report confirmed that the mold growing on the top of the ceiling was Stachybotrys. The sample on the bottom of the ceiling did not find Stachybotrys, indicating that the custodial cleaning of the area was effective.

It was determined that the mold was growing due to a leaking shower above the 111 suite. This shower was placed out of service until a temporary repair could be made to stop the leak. The complete repair will take place over winter break.

Below are pictures of the underside of the ceiling after cleaning and the top side of the ceiling when it was sampled. The underside has since been painted with mold resistant paint. The top side has been left undisturbed until the ceiling can be fully replaced. The shower will rebuilt the week of January 3 to prevent future leaks.

Building wide system components

On December 7, after the lab results of the airborne sampling were received, Ralph toured the mechanical systems of both dorms to look for locations with similar mold growth. None were found.

Ongoing Air Monitoring

To further assess whether there are likely conditions for growing mold in these dorms, air quality monitoring is being conducted in the 207 Pondside 3 suite. According to the EPA, the primary parameter of interest for assessing mold potential is relative humidity; this value should be kept below 60%. Monitoring between December 1 and 9 indicates that this suite continues to meet this criteria. Additionally, CO2 and fine particle levels in the suite remain at similar levels to those found in KSC classrooms. In both classrooms and dorms, fine particle sampling generally correlates to outdoor air quality conditions.

Next Steps

The presence of Stachybotrys in the airborne samples indicates that there could be other moist cellulose building materials in these dorms. In order to assess this concern, a systematic cleaning and review of the building’s living areas and mechanical spaces will take place over winter break. Specifically:

  • Custodial services will clean open surfaces and air diffusers in the suites.
  • KSC mechanics will clean interior of air handlers and replace air filters there; clean heater closets, including filter replacement and vacuuming the backs of doors and review the building’s exhaust system to assure its best functioning.
  • KSC Carpenters will replace the bathroom ceiling in P3 111 to
  • KSC EHS will arrange for resampling of airborne mold in early January. Upon request, EHS will review spaces for HEPA air cleaner placement in occupied area as appropriate. The primary considerations for air cleaner placement are specific health concerns related to the space and the size of the space that the cleaner will be placed in.


EPA Guidance on Managing Mold: https://www.epa.gov/mold

CDC Basic Facts about Mold and Dampness: https://www.cdc.gov/mold/default.htm

NIOSH Dampness and Mold Assessment Tool https://www.cdc.gov/niosh/docs/2019-115/pdfs/2019-115.pdf