@RandomDamage they can't, that's the point

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 ...