A new one for me.
I have noticed done here in FL that checking the street meters have some surprises.
No pressure regulators on any homes. A rare occasion I do find a backflow preventer buried in with the meter.
While watching the small rotary dial on a few homes I noticed it was slowly spinning, then it would reverse a small amount, then continue forward again. Back and forth it would spin.
Could this be a backflow siphon issue with the city?
Is a preventer needed, or what would cause the reversal?