North Stonington — Despite an unexpected extra three days of summer vacation for students at North Stonington Elementary, school was back in session on Tuesday afternoon, with few signs of last week's last-minute reshuffling.

The building was closed after air and dust samples in three rooms showed high levels of polychlorinated biphenyls, a suspected carcinogen, according to the U.S. Environmental Protection Agency. The elementary school was quickly reorganized to move instruction out of those three rooms.

Books, classroom supplies and other items were vacuumed and wiped clean of any suspected contaminants before they were moved out of the three closed spaces: the music room, the library and a room that housed math interventionists, Board of Education Chairman Bob Carlson said.

Besides a few who wondered aloud why their older siblings had started school earlier, students went about their day like normal Tuesday afternoon, introducing themselves to new classmates and playing outside at recess.

The only visible signs of the remediation process were infrequent silver-colored vertical stripes running down the school's walls: a special kind of paint that encapsulates PCBs and ensures they don't disintegrate into dust and get into the air.

In Rebecca Stegeman's fifth-grade classroom, nametags sat on every desk as students, with new haircuts and back-to-school outfits, asked her about class rules.

"What happens if you don't do your homework?" fifth-grader David Levanto asked. "Not that I'm not going to do it," he quickly added.

Stegeman took the answer in stride, explaining her system of reminding students about homework on a large easel pad at the back of the room and the increased expectations of moving up to fifth grade.

"Most important, your teacher is really sad" when students don't hand in their homework, she added.

A good deal of shuffling had to take place to make sure school was running smoothly on Tuesday.

Principal Veronica Wilkison said there has been a "domino effect" since the change shifted instruction from the three closed rooms into other classrooms.

Music instruction had been moved upstairs, and the social worker had to be moved downstairs. The library's books still were in the process of being moved, but Wilkison said she hoped to have them available to students soon.

Math interventionist Deanna Scanapieco was moved into part of a large fifth-grade classroom, divided with a temporary wall borrowed from Wheeler Middle School, and will use more of the space when she sees more students. She sees up to 75 students in a day, she said.

"Everyone has to have lots of flexibility," she said. "Flexibility with a smile."

On Thursday of last week, members of the school board and Superintendent Peter Nero, along with Eagle Environmental, which the district has contracted for the environmental testing, answered questions from a group of parents and teachers about the steps the school has taken to resolve the PCB contamination.

Going forward, if more testing would be conducted, Nero explained, the sampling will cost the school around $15,000 for every round. While the school building project approved in May 2016 budgeted $3.4 million for hazardous materials remediation, the state needs to first pass a budget so the renovation can get underway.

The full data from the latest round of testing should be available soon, Nero added, and the school has "complied completely" with everything that the EPA and the state Department of Energy and Environmental Protection has asked so far.

Carlson added that the school board will form a subcommittee to see how they can fast-track further testing for PCBs and how they can make the testing information easily accessible.

"I want to make sure parents have answers ... as quickly as possible," he said.

n.lynch@theday.com