+1. What Art said. Bottled water is (except for certain emergency situations) a scam/idiot tax of the first order. (Actually, though, it's so awesome in scope, hypnotizing millions of otherwise capable and rational people, that you almost have to admire it for its utterly shameless, insanely profitable, breathtaking infamy. Big, big wow. Al Capone had nothing on these guys.)

But regarding the OP: yes, I'm getting a fresh test done, including chemical. Being on a relatively shallow well in farming/oilfield country, I should really be doing it yearly. It's free up here, so there's no excuse for my dumb-arse laziness.

Interesting thing about nitrates: a symptom is a perpetually loose digestion (trying to be delicate). Might explain a few things around here (TMI! TMI!).

Nitrate issues can occur anywhere: in the '70s, oil exploration crews in the far Canadian North complained about perpetual diarrhea. Their water source was pure glacial meltwater; but the geology of the rocky soil that the streams ran through added a massive load of dissolved nitrates.