Greater Austin/Travis Regional Radio System (GATRRS) Talkgroup Research
From The RadioReference Wiki
1473 is not Security Team 2; they are discussing which baggage conveyor belts to use. As far as I know there is only one security talkgroup.
They have allocated to them Facilities Maintenance, Building Maintenance, and Airfield Maintenance. There are also Operations, which deals with things like flights being late and gate changes and such, and Operations Security, which are the heavily armed men in black roaming the concourse. There are 4 talkgroups allocated for general purpose airport use that are not used for anything. There are a few others as well. I can't identify which talkgroup number goes with which use however.
September 2017 observations:
TG 563: no longer parking enforcement, traffic revolves around repairing hydrants.
TG 554: appears to be the new parking enforcement TG. Talk group not currently listed here.
TG 617: WCSD (COA Wireless Communications Services Division) -- heard testing BDA system at a water plant. Talk group not currently listed here.
TG 592: Security team, possibly for city hall based on traffic. Talk group not currently listed here.
TG 3625: Some form of police, traffic indicates Del Rio, TX area. Talk group not currently listed here.
TG 1240: St. David's Pflugerville ER. Talk group not currently listed here.