When Keith Rapp gets a drink from his kitchen, it's quite a process.
The water comes in through a filter on the back of his refrigerator, then through another filter inside the fridge. From there, Rapp fills a Brita pitcher, then a water bottle with its own carbon filter in the cap.
"This will be the fourth filtration of this water," he said, taking a sip from the bottle. "That's how we do water here."
Rapp lives in the east Twin Cities metro where the groundwater was contaminated by chemicals produced for decades by 3M.