The treatment plants in the USA are not working properly because they can't handle changing conditions.
When there's drought, human poop doesn't also get reduced. We keep pooping at the same rate. So the sewage is not as diluted as it is when we have normally expected amounts of rainwater.
When we have too much rain, there's issues with containing our sewage from getting into the groundwater and aquifers ...
@RandomDamage turns out that removing nitrates is extremely hard though. If your water treatment plant doesn't use Reverse Osmosis, it's not gonna get removed. There is an ion exchange filtration technology that can also remove them but it's incredibly expensive to operate so it's not likely to ever be used at scale.
@feld well, it's going to suck. There's a lot of people in the red and orange areas and they can't all move
It's a problem that's going to have to be dealt with in various ways in place.
Which probably means the expensive water treatment solutions in your other comment, and hoping that with practice we can find ways to bring the cost down
@RandomDamage yeah moving is super expensive and there are countless reasons why people can't relocate but if you can or you're planning to... I would definitely urge people to consider this variable