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EWG's Tap Water Database — 2021 UPDATE

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Chromium (hexavalent)

Sonoma County Water Agency

Chromium (hexavalent) is a carcinogen that commonly contaminates American drinking water. Chromium (hexavalent) in drinking water may be due to industrial pollution or natural occurrences in mineral deposits and groundwater. Read more about chromium (hexavalent).

MORE ABOUT THIS CONTAMINANT

 

74

Samples

0

Samples exceeding legal limit (MCL)

20

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.165 ppb134ND - 0.600 ppb
20150.208 ppb135ND - 0.640 ppb
20160.0431 ppb131ND - 0.560 ppb
20170.0491 ppb111ND - 0.540 ppb
20180.614 ppb135ND - 3.60 ppb
20190.209 ppb114ND - 0.640 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.02 ppb

The EWG Health Guideline of 0.02 ppb for chromium (hexavalent) was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.

ppb = parts per billion

All test results

Date Lab ID Result
2014-08-191610-012-0825ND
2014-08-191610-001-0740ND
2014-08-191610-003-0915ND
2014-08-191610-008-0630ND
2014-08-191610-015-1000ND
2014-08-191610-018-0430ND
2014-08-201610-017-1045ND
2014-08-201610-019-04400.600 ppb
2014-08-201610-020-0950ND
2014-08-201610-007-06400.500 ppb
2014-08-201610-050-08250.550 ppb
2014-08-201610-002-07200.500 ppb
2014-08-271610-006-0750ND
2015-08-111610-008-0700ND
2015-08-111610-012-09000.640 ppb
2015-08-111610-017-0415ND
2015-08-111610-018-05000.510 ppb
2015-08-111610-015-0945ND
2015-08-111610-003-11300.500 ppb
2015-08-111610-001-07450.530 ppb
2015-08-121610-050-08300.520 ppb
2015-08-121610-020-1100ND
2015-08-121610-019-1005ND
2015-08-121610-007-0640ND
2015-08-121610-006-1145ND
2015-08-121610-002-0730ND
2016-08-301610-018-0850ND
2016-08-301610-017-1030ND
2016-08-301610-015-0950ND
2016-08-301610-012-08380.560 ppb
2016-08-301610-001-1340ND
2016-08-301610-002-0800ND
2016-08-301610-003-0920ND
2016-08-311610-008-1045ND
2016-08-311610-006-0600ND
2016-08-311610-050-0800ND
2016-08-311610-020-0515ND
2016-08-311610-007-0930ND
2016-10-121610-019-0900ND
2017-08-281610-001-0815ND
2017-08-281610-002-0950ND
2017-08-281610-003-07300.540 ppb
2017-08-281610-017-0920ND
2017-08-281610-015-0845ND
2017-08-291610-007-1030ND
2017-08-291610-019-1145ND
2017-08-291610-050-0745ND
2017-08-291610-020-0515ND
2017-08-291610-006-0610ND
2017-08-291610-008-0930ND
2018-08-271610-007-1110ND
2018-08-271610-050-0930ND
2018-08-271610-008-1130ND
2018-09-041610-003-0950ND
2018-09-041610-015-09003.60 ppb
2018-09-041610-002-1230ND
2018-09-041610-020-0915ND
2018-09-041610-006-08300.600 ppb
2018-09-041610-017-09350.580 ppb
2018-09-101610-019-0910ND
2018-09-111610-001-11151.50 ppb
2018-10-161610-001-0930ND
2018-12-061610-015-08001.70 ppb
2019-09-091610-008-09300.540 ppb
2019-09-091610-050-0730ND
2019-09-091610-020-0850ND
2019-09-091610-007-1100ND
2019-09-091610-006-08100.540 ppb
2019-09-101610-002-0810ND
2019-09-101610-015-07200.640 ppb
2019-09-101610-001-1040ND
2019-09-101610-017-0740ND
2019-11-121610-019-1145ND
2019-12-171610-003-10050.580 ppb