@paxmundi This is another one of those issues surrounding MAC & Bronchiectasis where the answer is "It depends."
If you have GERD, where stomach contents can be forced upwards from the throat and inhaled, and water happens to be in the mix, and the water has significant numbers of NTM bacteria, you could get NTM from water into your lungs.
Or, if like @kathyjjb or me, you have a swallowing disorder, you could aspirate water while drinking if you begin to choke/cough. We have both done therapy to alleviate this (I still need to do the exercises every few days.)

Different people take different approaches to the situation. Some only drink boiled water, others use a LifeStraw or similar filter (.2 microns or smaller) to remove any NTM. Some people drink bottled spring water (from natural ground springs, which has low or no NTM in it.) This is different from purified drinking water, which is municipal water further purified or filtered, but with no particular standards. Others drink whatever is available, and let the chips fall where they may.

What do I do? I drink water from a dual filter system with a larger pore 1 micron filter and a .2 micron final filter. If I am out, and plan ahead, I carry my own or bottled spring water. If not, I drink whatever is available. Have been doing this for years without getting reinfected - maybe I am just lucky.