A disaster like the January 2014 contamination that cost 300,000 residents of Charleston, W.V., their drinking water could happen almost anywhere in the United States. Fortunately, environmental journalists have access to information that could help the public learn about threats to drinking water and act to head them off.
At a Senate Environment Committee hearing  February 4, 2014, there seemed to be bipartisan agreement that current laws, regulations, and enforcement have proven inadequate to keep drinking water safe. Major drinking water utilities are supposed to conduct and make public "source water assessments," but often these take digging to get. And even then, they may miss crucial threats. The Freedom Industries chemical tank farm was there in plain sight a mile upstream of the Charleston intake, but the source water assessment did not identify it.
While EPA and local utilities do make much data available online, the Environmental Working Group (EWG) has compiled a database that is much easier for a non-specialist to use. EWG's tap water database, first published in 2009, gathers data from the states as well as from EPA, and compiles city-by-city rankings of the best and worst drinking water quality. It also explains the health significance of contaminants and lists contaminants not regulated by EPA.