Alpharetta has approved a $117,000 contract to install vehicle exhaust ventilation systems at four of its fire stations.

The award comes six months after the City Council approved a contract with EMS Specialty Equipment for $98,900, including installation. Gary George, public safety director, said that contract was withdrawn after more due diligence was conducted.

Fire stations 1, 2, 3 and 4 do not have exhaust systems in their bays, resulting in a carbon dioxide buildup whenever firetrucks are running, even with the bay doors open.