It appears that 22 days ago user dwyerm posted about a recent flood at the West Point treatment plant in the Puget Sound area: https://news.ycombinator.com/item?id=14914743

The article mentions "millions of gallons of raw wastewater dumped into Puget Sound in 2000, 2006 and 2009" as well as "millions of gallons of wastewater began flooding the plant" [this time, in 2017].

I could find no source indicating that the flooded water was "treated drinking water", nor that the EPA pitched a fit.