Recent news stories discussed a report by The Environmental Working Group (EWG) that said the chemical compound Hexavalent chromium (chromium(VI), Cr(VI), chromium 6) has been detected in water supplies for most U.S. cities, including Seattle.
Seattle’s water—and the water Seattle Public Utilities (SPU) provides to other local water utilities—is safe to drink.
SPU tested for chromium-6 in its water last year, and the results are contained in SPU’s 2015 Water Quality Report (Page 14). Sixteen SPU tests at four testing locations showed that Hexavalent Chromium is present in SPU’s water in low amounts, within a range of 0.063 to 0.17 parts per billion (ppb).
In California, one of the few places chromium-6 is regulated, the regulatory level is 10 ppb — 100 times the amount detected in SPU’s water.
Chromium-6 is an unregulated compound under U.S. Environmental Protection Agency (EPA) rules, and in most U.S. states, including Washington. The compound occurs naturally in the environment from the erosion of natural chromium deposits. It can also be produced by industrial processes. There are demonstrated instances of chromium being released to the environment by leakage, poor storage, or inadequate industrial waste disposal practices.
The City of Seattle owns or controls more than 100,000 acres of watershed that are closed to general public access. We protect these watersheds from fire, toxic spills, invasive species, and human disturbance.
For more information, visit the following EPA sites: