Your water supplier may be using chloramine as a disinfectant, which is usually 5 parts chlorine combined with1 part ammonia. This is what my water supplier did, and my tests on the tap always a slight ammonia reading.
I would have checked for you, but "USA" as your location in your ID is too vague. You can find out yourself by googling your cities "drinking water quality report".
If you see the word chloramine, or Total chlorine as a disinfectant, that's the clue.
If it only states chlorine, then the ammonia is not coming from the tap.
I never added ammonia neutralizers, because with a healthy population of beneficial bacteria it was taken care of.