Toxic Hexavalent Chromium Released into Tap Water Through Pipes

The 2000 film “Erin Brockovich,” based on a true story, launched the carcinogen hexavalent chromium into the spotlight. Water supplies in California were tainted with the chemical, which caused a plethora of residents in Hinkley to succumb to cancer and all sorts of other deadly diseases.

A new study is bringing this chemical back to light by analyzing the process in which it infiltrates the drinking water supply, specifically when commonly used chlorine disinfectants corrode cast iron water distribution pipes.

Chromium occurs naturally and is often added to countless products. Its toxicity varies depending on its state. More than 200 million people in the United States drink tap water with chromium concentrations above .02 ppb, according to the Environmental Working Group. The state of California has set this part-per-billion level to ensure that fewer than one out of a million exposed people will get cancer in their lifetimes. The United States Environmental Protection Agency (EPA) does not regulate chromium levels in drinking water.

In the past, scientists hypothesized that chromium found in drinking water came from outside the distribution system, emerging from natural sources such as groundwater, surface water, or industrial pollution. However, environmental engineer Haizhou Liu and his team at the University of California, Riverside, noticed that reactions within water pipes might raise chromium levels at the tap.

Sections of cast iron pipes from two drinking water systems were obtained for the study. Cast iron is the most common type of pipe, and it contains significant amounts of added chromium, which acts as an anti-corrosive.

The scientists discovered that scales of flakes from within the pipes produced chromium. “The oxidation of chromium in the scales by chlorine disinfectant accounts for most of the formation of hexavalent chromium released into the solution,” Liu said.

“Now that we know that cast iron pipes are a potential source of hexavalent chromium, utilities need to think proactively to use less reactive disinfectants and limit the amount of chromium allowed in new drinking water pipes,” said Lynn Katz, an environmental engineer at the University of Texas.

To learn more about hexavalent chromium, visit Erin Brockovich’s website. To install a water filter in your home, contact the experts at Reynolds Water Conditioning today.

Reynolds Water Conditioning was established in 1931 and is Michigan’s oldest water conditioning treatment company. Still owned and operated by the Reynolds family, we take pride in providing the highest quality products at a cost-effective price. If your tap water lacks the quality you deserve, contact us today at or call 800-572-9575.

Written by the digital marketing staff at Creative Programs & Systems:

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