Know Your Environment. Protect Your Health.

Chlorate

Whitworth Water District 2

Chlorate forms in drinking water as a byproduct of disinfection. Chlorate impairs thyroid function, making chlorate exposure most harmful during pregnancy and childhood. Read More.

In 2002, California scientists proposed an advisory value, called an action level, for chlorate at 200 parts per billion. Between 2013 and 2015, the EPA collected data through the Unregulated Contaminant Monitoring Rule program and found that over 15 percent of water tests from 38 percent of utilities had chlorate levels above a health-protective concentration, which federal scientists defined as 210 parts per billion, nearly equivalent to the California advisory value.

Click here to read more about disinfection byproducts.

 

28

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND140ND
2015ND140ND
2016N/A00N/A
2017N/A00N/A
2018N/A00N/A
2019N/A00N/A
2020N/A00N/A
2021N/A00N/A
2022N/A00N/A
2023N/A00N/A

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 210 ppb

The EWG Health Guideline of 210 ppb for chlorate was defined by the Environmental Protection Agency as a benchmark for testing under the Unregulated Contaminant Monitoring Rule program. This health guideline protects against hormone disruption.

ppb = parts per billion

All test results

Date Lab ID Result
2014-07-15WA97-SE1-14-13634-31796ND
2014-07-15WA97-SE1-14-13634-31790ND
2014-07-15WA97-SE1-14-13634-31789ND
2014-07-15WA97-SE1-14-13634-31795ND
2014-07-15WA97-SE1-14-13634-31797ND
2014-07-16WA97-SE1-14-13634-31792ND
2014-07-16WA97-SE1-14-13634-31788ND
2014-07-16WA97-SE1-14-13634-31787ND
2014-07-16WA97-SE1-14-13634-31794ND
2014-07-16WA97-SE1-14-13634-31798ND
2014-07-16WA97-SE1-14-13634-31799ND
2014-07-16WA97-SE1-14-13634-31800ND
2014-07-16WA97-SE1-14-13634-31791ND
2014-07-16WA97-SE1-14-13634-31793ND
2015-01-12WA97-SE2-15-01346-3174ND
2015-01-12WA97-SE2-15-01346-3172ND
2015-01-12WA97-SE2-15-01346-3171ND
2015-01-12WA97-SE1-15-01346-3176ND
2015-01-12WA97-SE2-15-01346-3173ND
2015-01-12WA97-SE1-15-01346-3183ND
2015-01-12WA97-SE1-15-01346-3181ND
2015-01-12WA97-SE1-15-01346-3182ND
2015-01-12WA97-SE1-15-01346-3180ND
2015-01-12WA97-SE1-15-01346-3178ND
2015-01-12WA97-SE1-15-01346-3175ND
2015-01-12WA97-SE1-15-01346-3177ND
2015-01-13WA97-SE1-15-01346-3184ND
2015-01-13WA97-SE1-15-01346-3179ND