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EWG's Tap Water Database — 2019 UPDATE

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Chromium (total)

Northwest Utilities

Chromium is a naturally occurring metal, but industrial uses can elevate its levels in water. One form, hexavalent chromium, causes cancer. Total chromium is not a good indicator of the amount of hexavalent chromium in drinking water.

 

42

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20121.60 ppb330.600 ppb - 2.30 ppb
20130.111 ppb91ND - 1.000 ppb
20140.0329 ppb213ND - 0.270 ppb
20150.733 ppb32ND - 1.10 ppb
2016ND30ND
20172.90 ppb331.20 ppb - 3.80 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EPA Maximum Contaminant
Level (MCL) 100 ppb

The legal limit for total chromium, established in 1991, was based on a 1958 toxicity study in laboratory animals, and applies to both the less-toxic trivalent chromium and the more-toxic hexavalent chromium forms of this compound. This limit does not protect against the risk of cancer from ingestion of hexavalent chromium.

ppb = parts per billion

All test results

Date Result
2012-08-220.600 ppb
2012-09-041.90 ppb
2012-09-042.30 ppb
2013-08-061.000 ppb
2013-08-06ND
2013-08-13ND
2013-10-23ND
2013-10-23ND
2013-10-23ND
2013-10-23ND
2013-10-23ND
2013-10-23ND
2014-01-14ND
2014-01-14ND
2014-01-14ND
2014-01-14ND
2014-01-14ND
2014-01-14ND
2014-04-29ND
2014-04-29ND
2014-04-29ND
2014-04-29ND
2014-04-29ND
2014-04-30ND
2014-07-140.220 ppb
2014-07-140.200 ppb
2014-07-14ND
2014-07-14ND
2014-07-140.270 ppb
2014-07-21ND
2014-07-21ND
2014-07-21ND
2014-08-20ND
2015-09-15ND
2015-09-151.10 ppb
2015-09-151.10 ppb
2016-09-12ND
2016-09-12ND
2016-09-12ND
2017-08-233.80 ppb
2017-08-233.70 ppb
2017-08-231.20 ppb