Chromium

WaterOne's state-of-the-art water quality lab runs over 120,000 tests on over 18,000 water samples each year to ensure the finest water reaches our customers' taps. This includes monitoring for substances like chromium.

Chromium is an odorless and tasteless metallic element found naturally in rocks, plants, soil and volcanic dust, and animals. The most common forms of chromium that occur in natural waters in the environment are trivalent chromium (chromium-3) and hexavalent chromium (chromium-6).

Chromium-3 is an essential human dietary element and is found in many vegetables, fruits, meats, grains and yeast. Chromium-6 occurs naturally in the environment from the erosion of natural chromium deposits, and it can also be produced by industrial processes.

EPA has a drinking water standard of 100 parts per billion (ppb) for total chromium, which includes all forms of chromium including chromium-6. Water systems are required to test for total chromium.

Chromium-6 and chromium-3 are covered under the total chromium drinking water standard because these forms of chromium can convert back and forth in water and in the human body, depending on environmental conditions. Measuring just one form may not capture all of the chromium that is present. In order to ensure that the greatest potential risk is addressed, EPA's regulation assumes that a measurement of total chromium is 100% chromium-6, the more toxic form.

WaterOne rigorously monitors to ensure the safety of our customers. Trace levels of total chromium remain at safe levels, a fraction of the EPA's regulatory limit.

Public safety is our priority. If WaterOne detects this or any other harmful substance in the water supply, we are required by law to notify the public. To ensure we reach you with important information about water quality and your water service, sign-up for Notify JoCo.