The Chattanooga Fire Department is an ISO Class 2 department, with 400 full-time firefighter positions. These firefighters provide fire suppression, hazardous materials response, rescue, and emergency medical services to approximately 156,000 citizens in an area of roughly 145 square miles. The Chattanooga Fire Department currently operates 24 front-line companies mobilized out of 17 fire stations. These 24 companies consist of ten 75-foot quints, one 109-foot quint, one 104-foot quint platform, two 100-foot aerials, seven pumpers and three squads. The department also maintains three hazardous materials units. The Chattanooga Fire Department has recently been designated as a lead regional response agency for a ten-county Homeland Security District in southeast Tennessee. The department will field a team trained and equipped to respond to incidents involving chemical, biological, radiological, nuclear and explosive (CBRNE) weapons. The department will also provide a team to respond to technical rescue and water rescue incidents.