Mold was discovered in many of the school buildings, and the schools were closed for about a week.
Tuesday the elementary school students went back and Wednesday middle and high school students will go back.
Elementary school students are excited to be back in the classrooms after an unplanned week-long break.
Sandy Youngblood, a grandparent of an elementary school student, said, "They were kind of glad that they didn't go to school for a while but then they were antsy wanting to get back in."
Air quality test results came back from the school buildings with no unusual levels of mold. Students and parents are happy to be back on their normal schedule.
Marsha Sipe, a grandparent of an elementary school student, "I think he was happy because he didn't want to make up any days, he wanted his holidays off. I have four grandsons in the school district so we're kind of glad that they're all back. And they are too."
District officials are also relieved.
Assistant Superintendent Greg Milbrand said, "To see the kids in there smiling, happy, back in school, the teachers smiling and happy as well. It was just a great morning to start the day."
East Pennsboro middle and high school students will share the middle school building. The high school students will attend school for four hours in the morning and the middle school students for four hours in the afternoon.
But the high school building will be closed for at least three weeks while the pipes are re-insulated.
Sipe said, "We all weren't happy at first. We thought it could've been done beforehand. But I think they're doing the best they can right now."
Parents said ultimately the most important thing is the students are back in the classroom.
Youngblood said, "I think it's all working out for the best. You know. You just do the best you can in a bad situation. And this is what we are doing."
District officials said they are still unsure as to how much it will cost to get rid of the mold in the schools.