By Robert Coleman, Environmental Working Group
In 2016, an EWG report found that chromium-6 – a cancer-causing compound made notorious by the film “Erin Brockovich” – contaminated the tap water supplies of 218 million Americans in all 50 states. But our just-released Tap Water Database shows the problem is even worse than that.
Based on test results obtained directly from almost 50,000 local water utilities, drinking water supplies for about 250 million Americans are contaminated with chromium-6. For about 231 million people, drinking water supplies have average levels of chromium-6 exceeding the one-in-a-million cancer risk level determined by California state scientists.
That may still underestimate the number of people exposed because water from most smaller utilities and private wells usually is not tested for chromium-6. Although it’s been almost a decade since the National Toxicology Program found the compound caused cancer in rodents when ingested, there are no federal regulations on chromium-6 in drinking water and no federal requirements for regular monitoring of chromium-6 in tap water.
There are a couple of possible reasons for the new, higher numbers in the Tap Water Database.
- The Environmental Protection Agency classifies utilities that purchase finished water from other public utilities as consecutive systems, which are only required to test for disinfectant byproducts, lead and copper. The database suggests that many consecutive systems are buying finished water tainted with chromium-6 from other utilities. To see if your water supplier is a consecutive system and may be purchasing contaminated finished water, look up your supplier in the Tap Water Database.
- California is the only state that set a public health goal and legal limit* for chromium-6, and requires water utilities to test for the chemical. EWG’s 2016 report was based on data from the EPA’s Unregulated Contaminant Monitoring program. The EPA-mandated testing involves only a small number of water utilities that serve less than 10,000 people.
We urge the federal government to follow California’s lead and set a nationwide legal limit on chromium-6 in drinking water, and require both large and small utilities to test for it. While the legal limit set by California in 2014 was too high to fully protect human health, it represented a step in the right direction. And until regular nationwide testing is required, we can’t know the true extent of contamination in public water utilities.
For now, we invite everyone to use our database to find out if there is chromium-6 in your water. If so, contact your local elected officials to express your outrage and use EWG’s Water Filter Guide to find a water filter that is certified to remove the contaminant.
*California set a legal limit in 2014 of 10 ppb, a level too high to fully protect health. After a legal challenge focused on how the costs of implementing the standard were calculated, the state was required to withdraw its limit in 2017 and start work on establishing a new state standard.