Flight Attendant reported potable water system contamination with cloudy and foul smelling water. Maintenance later reported missing parts and a main system filter froze in place and irremovable from its housing. It could not be determined when it had been previously replaced.

Narrative

ZZZ1 to ZZZ; we were not serving drinks due to expected turbulence. I made a pot of coffee in the FWD galley to which myself and Flight Attendant (FA) C had one cup. Pilots declined. This pot was then discarded. ZZZ to ZZZ2 we got new pilots. Pilots asked for coffee. I brewed a fresh pot for them and served to them during boarding. On taxi out; Captain (CA) called and asked for us to secure clear zone so he can hand us the coffee as it tastes horrible. I discarded the coffee. At altitude; I dumped the coffee pot and it didn't smell normal. I was thinking that it was just an old coffee pack. Later on; FA-B called me from aft galley stating that both of her coffee makers were making bad coffee as well and that passengers were complaining. I had already served my section but at this point; discontinued all hot beverages. I checked the hot water from the forward galley and the water was cloudy. Pilots were notified.On the Ground in ZZZ2; Maintenance stated that they are emptying the water tank and replacing the filters. Maintenance had the forward galley filter out and said that it was so old that parts of it are missing. He couldn't get the filter out of the socket it had been there that long. We had a crew change at this point; so I am not sure as to what else was discovered at this point.