I dislike amazon as much as the next guy, maybe even more. That said, the "techspot" summary article is a huge simplification of a much larger wastewater issue in the area. It basically regurgitates and attempts to amplify Amazons culpability in an issue that frankly they are a rounding error in. But no one really gives a shit about well water and farmers but they do love to hate big tech(and rightfully so in many cases) so thats the hook I guess. The Rolling Stone article is worth a read(its linked in the techspot summary).
https://www.rollingstone.com/culture/culture-features/data-center-water-pollution-amazon-oregon-1235466613/
The good news, as I understand it, is nitrates are effectively removed from drinking water with Reverse Osmosis filtering which is a few hundred to few thousand dollars per house. Of course thats not free, but not digging up every distribution pipe in the area type issue(Flint, MI)