@pamelasc1 Hi Pam - MAC/NTM are killed by heat well below the boiling point (I think I have read 145F?) so heating to boiling one time should be sufficient. I like my water COLD, so I place it in a well-scrubbed, covered pitcher in the refrigerator. I clean all cups, glasses, water bottles, pitchers, etc and my tea kettle with dish detergent, hot water and vigorous scrubbing regularly to keep any NTM and other germs at bay. This prevents the formation of the "biofilm" where NTM like to hide and reproduce. Studies of water pipes and shower heads seem to indicate the biofilm starts forming in a couple of weeks if not disturbed. When available, I use my dishwasher for this - but no space for one in my tiny house here in Texas. Sue