Denver hasn’t hit California’s goal for chromium in drinking water, but it’s complicated

Denver and all its surrounding counties (and a bunch of others in Colorado) reportedly have levels of chromium that exceed California’s goal.

Boaters on Chatfield Reservoir. (Kevin J. Beaty/Denverite)chatfield; reservoir; water; lake; denver; littleton; denverite; kevinjbeaty

You may remember hexavalent chromium from the film “Erin Brockovich,” which was of course about a small town contaminated by the carcinogen.

Last week, Environmental Working Group reported that 200 million Americans’ water was “tainted” by the chemical. Water supplies were considered to be tainted if their chromium-6 levels exceeded the public health goal set by California.

The public health goal is the level that is safe for a lifetime of consumption, as determined by the California Environmental Protection Agency.

Denver and all its surrounding counties (and a bunch of others in Colorado) reportedly have levels of chromium that exceed that goal.

Denver’s water registered at .0378 parts per billion, while California’s recommendation is 0.02 ppb. In other words, nearly double the California “goal.”

The contaminant occurs naturally in rock and enters the water supply through erosion, although it also can occur from industrial processes, according to a Denver Water spokeswoman.

That said, it’s important to understand that Denver’s chromium-6 levels don’t exceed any legal limits. In fact, California’s public health goal is not even the limit in that state. California actually allows up to 10 ppb, a limit that Denver meets.

Also, Denver is actually bound by the federal standard for chromium in general, not the California standard for chromium-6. The federal limit for chromium is much higher at 100 ppb.

What’s the plan?

Here’s the statement Denver Water provided to me:

“EPA is still evaluating the health effects of chromium and will determine if the total chromium (limit) needs to be adjusted and/or if a new regulation for hexavalent chromium is needed in drinking water.

Even though our hexavalent chromium levels are well below the California MCL, we are looking at ways to modify our practices to reach a goal of zero. Denver Water’s goal is to stay ahead of regulations and move in a proactive direction to maintain high-quality water delivery to our customers.”

Andrew Kenney

Author: Andrew Kenney

Andrew Kenney writes about public spaces, Denver phenomena and whatever else. He previously worked for six years as a reporter at The News & Observer in Raleigh, N.C. His most prized possession is his collection of bizarre voicemail. Leave him one at 303-502-2803, or email akenney@denverite.com.