'Because of the chromium'
There's something I don't understand in this movie. When Erin visits Donna Jensen for the first time and Donna reveals that PG&E paid for all the doctors visits, Erin asks why and Donna says "because of the chromium".
I don't understand this part. PG&E paid for the doctors because there is chromium in the water? And the residents weren't suspicious about this? Maybe I'm missing something here. Can someone please explain it to me?