Los Angeles County Public Works (PW) is responsible for the construction and operation of County roads, building safety, sewerage and flood control. PW also operates traffic signals and intelligent transportation systems, drinking water systems in some communities, five airports, paratransit and fixed route public transport. It administers various environmental programs, issues permits for activities in the public roadway, and has a Department Emergency Operations Center that works in conjunction with the County Emergency Operations Center operated by the County Sheriff's Department. PW is headquartered in Alhambra.