An Environmental Group Found Arsenic And Chromium In Tap Water In All 50 US States. Here’s How To Check What’s In Your Taps.

In 2017, the nonprofit Environmental Working Group (EWG) released a database of all the known contaminants lurking in US drinking water. After compiling data from 50,000 public water utilities across the country from 2010 to 2015, the group found 267 chemicals that they dubbed concerning to human health.

On Wednesday, the group announced an update to those findings: After analyzing the same data set from 2012 to 2017, the EWG found 278 contaminants in US drinking water.

The health risk of each contaminant is “going to vary region by region, state by state, utility by utility,” Tasha Stoiber, a senior scientist at EWG, told Business Insider.