A new report issued Tuesday from the Environmental Working Group, an independent advocacy group, examined water systems across the country. The results? About 218 million Americans are using tap water that contains levels of chromium-6 that the group considers "dangerous."
Those levels are at or above0.03 parts per billion, a designation found in 75% of the samples tested between 2013 and 2015. While the EPA has not set a limit for the chemical in drinking water, it has set a standard of 100 parts per billion for all forms of chromium. California enforces a maximum contaminant level for chromium-6 at 10 ppb, and is the only state in the nation to do so.
According to the National Toxicology Program, chromium is a naturally occurring element with many forms. Chromium-6 is produced by industrial processes, and is commonly used in electroplating, stainless steel production, leather tanning, textile manufacturing and wood preservation. It is also found in the ash from coal-burning power plants and used in cooling waters.
The Environmental Working Group reviewed the EPA's third Unregulated Contaminant Monitoring Rule for its report. The report indicated that only one public water system had total chromium exceeding EPA standards, but 2% of the water systems -- 1,370 counties -- had chromium-6 levels exceeding California's standard, according to the group.
Oklahoma, Arizona and California had the highest average statewide levels of the chemical in their water system, and Phoenix had the highest average level of any large city. St. Louis County, Houston, Los Angeles and Suffolk County, New York, also had relatively high levels.
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