Wilton officials are trying to get ahead of a burgeoning mold situation at two district schools, and hope that an improving dryer weather forecast will let their efforts at remediation take hold.
Wilton Public Schools Superintendent Kevin Smith briefed Board of Education members Wednesday evening, Sept. 13. at a special meeting held to update them on how the schools were handling the air quality contamination issue.
He confirmed what they’d been told at their regular meeting last week: several factors, including continued high temperatures and rainy weather coupled with aging HVAC equipment and COVID-era guidance on circulating fresh outside air indoors had combined to cause “mold blooms in several classrooms” at Cider Mill and Middlebrook Schools just as the school year started.
Deep Cleaning and Air Scrubbing
Smith said air testing confirmed what was suspected after teachers reported “musty odors,” and custodians found water pooling underneath carpets that wouldn’t dry. The district’s maintenance team has started remediation efforts.
“They have gone through and deep cleaned all the rooms. We have purchased a number of dehumidifiers as well as air scrubbers. We placed those in classrooms. We’ve done some repeated air testing to try to lower the humidity levels and just make sure that we’re responding appropriately. At Middlebrook, we’ve done the same thing and then we took the added step, because the carpets were retaining moisture, of removing carpets in a number of the classrooms and replacing that with LBT tile,” Smith said.
Since implementing those strategies, Smith said most of the repeat testing has come back “well within normal ranges.”
“So we feel pretty good that the mitigation strategies that we’re using are effective,” he said.
Facilities manager Jose Figueroa said visual inspection in several classrooms that included opening up walls and checking above ceiling tiles found no mold behind any structrual features.
He added that surfaces were cleaned with bleach and air scrubbers and dehumidifiers with HEPA filters have been employed “so that we can cleanse the air, just making sure that we’re getting all the particles out.”
Fresh Air — Good or Bad?
But complicating matters is the need to use ventilators that pull in fresh air from outside. With multiple days of rain over the last several weeks, the air being pulled into the schools has had very high humidity levels.
“That’s a huge problem. … Down in that Cannondale area [of Cider Mill], the average humidity levels were 85% which is the cause of these mold spores. You add the 85% humidity and then the dew point is 60,” Figueroa said.
He added that bringing in dehumidifiers has helped “quite a bit,” and that he has purchased additional units to use in high humidity areas.
It’s a balance that will continue to be complicated for maintenance staff.
“We’re working on trying to tweak the system, but again, we have the air flowing into the building especially as we approach the flu season. We can’t restrict classrooms or anything like that because it could cause another problem,” Figueroa said.
Some of the school equipment is older and is in need of repair or replacement. Figueroa said the aging equipment is struggling to keep up with the protracted heat and high humidity.
“We’re making those repairs as they come up, but it’s getting to a point where we’re wearing out our equipment pretty, pretty, pretty quickly with the CDC regs and the amount of time that we have to have these units running. …. It’s a huge strain,” Figueroa said.
Air Samples — How Much and What Kind of Mold?
District air quality consultant Scott Johnson, an industrial hygienist with Atlas Technical Consultants, was called in to take air samples and give additional guidance.
His testing showed that some remediation efforts were quickly effective, with mold levels dropping after surfaces were deep cleaned and moisture levels were brought down. But in other classrooms, additional steps needed to be taken, including removing carpeting completely and putting sealant epoxy on the concrete before installing LBT tiles.
“Those numbers came back, they went down from 80,000 to 720,” Figueroa said, adding that a plan is being put into place to replace carpeting in first floor classrooms at Middlebrook in the yellow core, while students and teachers in those classrooms will be temporarily relocated until the work is completed.
Johnson was able to confirm that the types of mold spores found in the schools were common and not as dangerous as black mold, which was not found in the buildings.
“We did not find any stachybotrys, which is the toxic mold everybody talks about, which is very good. That was not in any samples that we found, so you’re good there,” he said.
He made recommendations for moving forward. “I feel that removing the carpets if you can, keeping the relative humidity down, do a general cleanliness of the unit ventilators, the vents; any condensation that you find, searching for pipe leaks, condensation drips above the ceiling from pipes, just to stop the potential growth from water,” Johnson said.
Replacing carpets in classrooms and areas that are the most impacted is estimated to cost between $50-60,000, according to Smith.
One thing Johnson said would be impossible was eliminating mold completely.
“It’ll never be mold free. There’s mold everywhere because you’re opening doors, windows, you have fresh air coming in. So you’ll always have mold. You’ll never get it down to zero. It’s just a matter of the levels of mold spores that you get, just keep them down. And the types of mold species,” Johnson said.
BOE Vice Chair Jen Lalor asked if it was impossible for any place to be completely mold free.
“Maybe operating rooms because you have the positive pressure and positive HVAC filtration, but there’s mold everywhere. You’ll never be free of mold. Because you’re outdoors, it’s on your clothes, it’s on your shoes, it’s in your hair. So as soon as you walk in the room, mold’s everywhere.”
Longterm Approach
This past spring, town officials approved a contract with KG+D Architects to begin a longterm facilities needs assessment focused on Cider Mill and Middlebrook, as well as Wilton High School.
But in the more immediate timeframe through spring, BOE Chair Ruth DeLuca wanted to know if Johnson thought the district should be doing more testing or additional protocol planning.
“Your main concern is to stop the moisture intrusion which will stop the growth [of mold]. So your humidity levels, your condensation any pipe leaks. Once you stop those, then your mold counts will go down,” he said, something that will change season to season. “We’ll try to do air testing periodically for complaint areas once a year here and there, just to see if the levels stay or if you have additional issues…But what you’re planning on doing should be the route to go.”
All testing and result reports will be added to the Wilton Public Schools website once they are completed.