From the NRDC:
"America has a drinking water crisis. An NRDC study has found that contaminants that may harm human health are found in tap water in every state in the nation.
Established in 1974, the Safe Drinking Water Act is one of our bedrock environmental laws, consisting of rules that regulate about 100 contaminants found in drinking water. NRDC has documented serious problems with our outdated and deteriorating water infrastructure, widespread violations and inadequate enforcement of the Safe Drinking Water Act for more than 25 years.
Our analysis shows that in 2015 alone, there were more than 80,000 reported violations of the Safe Drinking Water Act by community water systems. Nearly 77 million people were served by more than 18,000 of these systems with violations in 2015. These violations included exceeding health-based standards, failing to properly test water for contaminants, and failing to report contamination to state authorities or the public. What’s worse, 2015 saw more than 12,000 health-based violations in some 5,000 community water systems serving more than 27 million people."