Riser Banging and Water Running in Apartment Building Wall

[Scott Steven NYC]

HELP! The below links (#2 and #3) are examples of banging sounds we hear throughout the day in our wall in an apartment building. The building's water riser is the only plumbing in the wall as well as the waste line. We also hear the sound of flowing water (line #1) for periods of up to 30/40 minutes. Noone can figure this out. Any thoughts?

https://youtube.com/shorts/r-kNg9cdZNY?feature=share

https://youtu.be/G3L4fmMU1AQ



https://youtu.be/G3L4fmMU1AQ

 

[ScaringTheShitOutOfPoop]

Do you have any water coming out of the walls at anywhere?