The joint authority was approved in 1977 to govern the airport.
All three cities also share a stake in the Magnolia Power Plant in Burbank, adding to annual saving accrued through membership of the Southern California Public Power Authority.
In Glendale, the Verdugo Fire Communications Center serves the tri-cities along with Alhambra, Arcadia and seven other communities.
Verdugo dispatch, officials said, is a prime example of cities not having to cede their identities, along with a recently approved joint helicopter agreement among all three cities. The deal saves Burbank and Glendale about $400,000 annually.