Most... MOST tap drinking water is safe. There are incidents such as the Flint, Michigan lead which render the water unfit for drinking. Those are the exceptions.
If people complain of chlorine, the water supply probably is still simply chlorinating and not going to chloramines. Many systems feed some ammonia after the chlorine. Without the ammonia, chloramines, the chlorine off-gasses and will lose its residual as it moves out into the distribution network. Hence, those living closer to the treatment plants will taste/smell chlorine because it's stronger there than further out in the system. With the ammonia binding with the chlorine, water can leave the plant with a slightly lower residual and a more even taste/odor throughout the system.
As far as water tasting different from one place to another... Different source water can certainly have an effect on the taste/odor of the finished water. Well water will usually have some minerals in it, mainly iron and manganese. Surface water... is it a lake or is it a river/stream. Lakes turn over and the source water changes season to season. Rivers/streams are affected by runoff so can go from fairly clean to muddy in a moment's notice during hard rains. The changes can be anticipated, but no one can outthink Mother Nature.
Building water treatment plants over the years, I have been extremely particular that walls are straight... piping connections are aligned... paint and coating systems are applied evenly... blue is blue and green is green. A new plant will go on line and user will never know until a local newspaper publishes the news. Immediately, the plant will get calls saying "Our water tastes different!". The best thing the supplier can do is invite those customers to the new facility. If it is dirty, paint doesn't match, concrete not finished to flat texture, etc. the water will never taste good. OTOH, if a customer comes into the plant and leaves swearing they had been in a hospital, library, or new school due to the professional workmanship... they will leave telling everyone how great the "new" water tastes.
Nothing more rewarding than seeing muddy, dirty water coming into a treatment plant and leaving as excellent drinking water. That accomplishment is a combination of science, hard work, experience, and a staff dedicated to providing only the best quality product for their valued customers.
