s the flavored Safeway select water good for you or is the acid and
sweetners used dangerous for tooth decay and other health issues?

Acidic drinks, weather sugar free or not, are bad for teeth. Try to
drink plain water as an alternative, and stay away from citrus
flavors. This is also why you should avoid citrus drinks such as
orange juice late at night. Sugar free fizzy drinks, such as Diet
Coke, are still bad for your teeth, dispite the healthy aura they
create.

Still, these drinks are much better than their sugary alternatives.