There's a blue pipe (1" diameter) extending ~3 feet from the city water meter before transitioning to 1" copper, then the copper connects 2 feet later to my rusted galvanized. I've run new pex-a pipe throughout the house, copper for above-ground section (e.g. hose bibs, shut-off valve), and planned to run pvc schedule 80 to the service line. Thought the service line was copper but turns out it's a blue pipe.

How do I know if this is pex pipe or polybutylene? I don't see any markings. Appears to be connected to the copper pipe with a compression union. I don't know when it was installed.