Major renovations started in the fall of last year after mold was found inside the walls of the bunk area where firefighters sleep.
"We noticed a smell, and we just kept having problems with moisture," said Belton Fire Chief Bruce Pritchard.
Pritchard said the quality of the air was tested to make sure firefighters were not at risk of getting sick.
"Once they came and did the tests, that's the only place the mold was. The firefighters were never in danger," Pritchard said. "It wasn't exposed to the outside area. They found it once they got in it, so the living area was never exposed to the mold."