A lingering smell at Oxford Center School has stumped local and state health experts for years and has parents worried.
"It smells like a basement," Kerry Mizak, a mother of three, said.
"Like you threw dirty laundry in the washing machine and left it for a few days," Kim Gugliotti, mother of a fourth grader, said.
"It's a mystery," Oxford Superintendent Annie Ortiz said.
Oxford Center School is a sprawling campus built in the 1940s and 1950s and around 500 students in third through fifth grade, teachers and staff members spend more than 30 hours here every week.
Last spring, people started complaining of a strong moldy, musty smell in "Building One."
"Our children are coming home with this odor in their clothing, in their hair, books, backpacks," Mizak said.
On Sept. 10, the district closed the two classrooms in the building and moved about 50 students to the art room and library for class.
After Christmas break, they moved again and took up residence in the newly-vacant portable classrooms across campus.
Gugliotti's daughter is in one of classes that's been displaced twice and said the learning environment in the library was “deplorable" and she has lingering questions about whether the campus is an appropriate place for young children to go to school.
"I'm anxious, I'm angry, and I would like to see something done and get some answers," Gugliotti said.
Superintendent Ortiz said the district has spent several months and tens of thousands of dollars to identify the source of the problem.
"Everyone has gotten to the same conclusion. No one knows exactly what the odor is. However, that doesn't mean the district is giving up," Ortiz said.
The district granted the NBC Connecticut Troubleshooters access to the classrooms in question.
"We removed all the ceiling tiles, anything that was porous, sheet rock walls, insulation. The odor is definitely far less today, but it's still present," said facilities director John Barlow, who has spearheaded several renovations.
The Pomperaug Health District has been involved as well and director Neal Lustig said his agency has responded to solve several strange odors in various buildings since 2003.
"This is an issue that may have been lurking in the background, but for some reason may have gotten worse," Lustig said.
This fall, Lustig brought in an industrial hygienist from the Connecticut Department of Public Health. She did not conduct any tests, and in her report, she simply recommended a change in air handler settings in Building One to increase air flow. The Troubleshooters reached out to the Department of Public Health, but the agency declined to comment on the report.
We asked Lustig about the potential of health problems in the future and how, if their not sure what the problem is, they can be sure there are no long-term concerns.
"You don't really know," Lustig replied.
Lustig has recommended they keep students out of the two classrooms in Building One, but district leaders say the bottom line is that they need to build a new school.
That's not a quick fix.
The town has funded a state-mandated facilities study that's underway right now.
District leaders expect the new school will cost in the range of $30 million to $40 million.
Based on the state's formula, the Department of Education would reimburse Oxford about 30 percent of the cost. That means taxpayers would have to approve bonding of about $25 million at referendum in order to get the construction started.
"It could take us anywhere from three to five years, minimum three," Superintendent Ortiz said.
Parents, including Mizak, whose asthmatic second grader is set to attend Center School in the fall, want answers now.
"Everyone agrees we need a new school, but we need to deal with the situation that's going on now and come up with a short term solution," Mizak said.
Ortiz said there are no other buildings in Oxford that can accommodate 450 students.
They are exploring the idea of busing the students to a vacant school building outside of town or keeping them where they are until a new school is finished.
"I have huge concerns over the state of what her health will be in 15 years, based on the conditions now," Gugliotti said.
The district expects the facilities study to be done next month and that will start the process to choosing a site and design for the new school.
After that, that next hurdle is for voters to approve the plan at referendum.