Chromium levels found to be low in Medford water

Medford's water sources contain only trace amounts of a potential cancer-causing element now under public-health scrutiny, meaning that what flows from your tap tests at lower levels than some teas, soft drinks and even some bottled water, research shows.

Medford Water Commission tests on its Big Butte Springs and Rogue River water intakes found light levels of chromium-6, an element found naturally in the western Cascade slopes but also the source of some industrial contamination elsewhere in the country.

Concerns about chromium-6 levels have been raised at municipal water-treatment plants throughout the United States. Medford's levels came in about the same as those in other Oregon cities, said Robert Noelle, the commission's water-quality superintendent.

"People need to keep perspective on this," Noelle said. "The numbers are extremely low."

In September 2010, an Environmental Protection Agency draft human-health assessment for chromium-6 proposed classifying it as a likely cause of cancer in people when ingested over a lifetime.

Current studies are now trying to determine a baseline threshold for what would be considered safe exposure levels similar to other regulated carcinogens.

EPA officials have said they expect to set that exposure level by the end of this year.

"At this point, we feel it is a non-issue for us until the standards are set," Noelle said.

Since the early 1980s, Medford has tested its water supplies for all forms of chromium heretofore regulated under an umbrella "total chromium" standard. That standard, which includes chromium-6, allows a maximum concentration of 100 parts per billion in U.S. drinking water.

All results of Medford's tests were less than 1 part per billion, according to the commission.

Noelle pulled water samples from Big Butte Springs and the Rogue River on Sept. 19 for testing strictly for chromium-6, and the results were returned earlier this month, he said.

Those levels averaged .16 parts per billion, ranging from .103 ppb to .190 ppb.

Consider that the global population is about to hit 7 billion people, "you are .16 ppb of the world population," Noelle said.

Recent testing conducted by Utah State University through the Water Research Foundation found higher chromium-6 levels in some teas, soft drinks and bottled water.

Teas in the tests showed levels of .15 ppb to 17.5 ppb, while soft drinks in the tests had chromium-6 levels ranging from non-detectable to 396 ppb.

Bottled water tested elsewhere off Oregon store shelves had levels from non-detectable to slightly more than 1 ppb, Noelle said.

The chromium-6 testing was possible because of scientific advances and does not suggest that chromium-6 is new to Medford water, Noelle said.

It is found naturally in rocks, plants, soils and volcanic dust. Trace amounts have been found in rivers and streams of the western Cascades, according to the commission.

"The waters flowing out of Big Butte Springs and the Rogue River probably had these levels in them for thousands of years," Noelle said.

Reach reporter Mark Freeman at 541-776-4470, or email at mfreeman@mailtribune.com.

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