Danbury officials are moving to update the master plan for the rapidly growing Reserve development on the city’s west side. More than 2,000 condos and apartments have now been approved or are under construction at the former Union Carbide campus, with city leaders citing major growth concerns. The revised plan would allow construction of a new firehouse to improve emergency response in the area. Mayor Roberto Alves says the city already has a contract to purchase land for the proposed station.