Water | Ecotrope

Portland Water Bureau to test for chromium-6

Ecotrope | Jan. 12, 2011 7:27 a.m. | Updated: Feb. 19, 2013 1:42 p.m.

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An environmental advocacy group tested tap water in Bend and found hexavalent chromium, a natural mineral and manufacturing byproduct that the EPA says "is likely carcinogenic in humans" though utilities are not specifically required to test for it in the water supply.

An environmental advocacy group tested tap water in Bend and found hexavalent chromium, a natural mineral and manufacturing byproduct that the EPA says "is likely carcinogenic in humans" though utilities are not specifically required to test for it in the water supply.

The Portland Water Bureau has sent out a response to the Environmental Working Group’s tests showing hexavalent chromium in drinking water across the country to reassure its customers that Portland water is safe to drink. The bureau says it will follow the Environmental Protection Agency’s new recommendations for how utilities can monitor the probable carcinogen and let customers know how much of it is in their drinking water.

Portland’s drinking water comes from the protected Bull Run and Columbia South Shore Wellfield watersheds, and the Portland Water Bureau tests Bull Run water for total chromium three times a year. Since 2000, 30 of 33 samples from Bull Run have shown no trace of chromium. The highest level detected was 3 parts per billion, which is more than 30 times below the federal limit for total chromium.

Note, however, that’s total chromium.

Hexavalent chromium is one of two key types of chromium that can be found in drinking water. Trivalent chromium is another kind, and it can actually have beneficial health effects. Hexavalent chromium, or chromium-6, is carcinogenic when inhaled, and the EPA has said it is a “likely carcinogen” when ingested. But the EPA doesn’t have specific drinking water limits for chromium-6 yet, so water utilities are not required to test for it. New standards for how much chromium-6 is safe to drink are still underway, but in the meantime, the Portland Water Bureau says it is developing a testing plan that will meet the EPA’s latest recommendations.

Any word from your utility on how they handle chromium-6? I’d be interested to hear about any new action on hexavalent chromium at other utilities around the state.

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