Originally Posted by hfly

Again, those are the regulations, in actual practice, the average water tank on a plane is sampled far less than the above. In any case, considering that your average narrow body a/c in the US has made as many as 1000 flights in a 3 month period, and possibly 4000 in a 12 month period, and could have had its tank filled for each and every flight, from different sources in the US as well as anywhere in the Caribbean basin, not to mention Mexico, Central and Northern South America, you still trust that water to drink?