I heard something about southern aquifers, like in Florida and the Bahamas getting sulfurous, especially if not enough water is run through them, but that there are also special filters for it.

My last experience with sulfur water was at summer camp in the early to mid 60's in upstate NY where for two summers the camp's water was dreadful, making everything taste and smell like rotten eggs. They said it was harmless, even good for us, but who knows? Even the camp's "bug juice" reeked of it.