Meanwhile, some Appalachian communities have discolored, polluted, or entirely absent tap water because of the very companies that bring jobs to the area. Lack of regulatory enforcement may contribute to that. "In recent years, the Environmental Working Group, a non-profit based in Washington, D.C., published a report that demonstrated a decades-long lack of enforcement on the part of the regulators and revealed that the agency’s 'safety levels' might be misaligned to the real-world environmental damage they cause, meaning that in light of the latest research the levels once deemed safe may, in fact, be harmful," Pytalski reports.
But even when safe levels for contaminants are known, it's still difficult to prove that mining and fracking operations are responsible for area health problems.
It's a complicated issue, but EWG has created a searchable Tap Water Database that makes it possible to check the water quality for every zip code in the U.S.