EWG's Tap Water Database — 2019 UPDATE


Chromium (hexavalent)

Layton City Water System

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).





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20130.435 ppb550.182 ppb - 0.629 ppb
20140.396 ppb550.102 ppb - 0.507 ppb
20150.429 ppb440.219 ppb - 0.550 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 Result
2013-09-100.310 ppb
2013-09-100.486 ppb
2013-09-100.182 ppb
2013-12-130.629 ppb
2013-12-130.568 ppb
2014-03-120.475 ppb
2014-03-120.507 ppb
2014-03-120.494 ppb
2014-06-120.401 ppb
2014-06-120.102 ppb
2015-03-260.454 ppb
2015-10-150.219 ppb
2015-10-150.550 ppb
2015-12-170.491 ppb