Know Your Environment. Protect Your Health.

Chlorate

City of Richland

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.

 

24

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20143.39 ppb182ND - 34.0 ppb
2015ND60ND
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
2014-06-03WA97-SE1-14-10122-24347ND
2014-06-03WA97-SE1-14-10122-24346ND
2014-06-03WA97-SE1-14-10122-24344ND
2014-06-03WA97-SE1-14-10122-2434327.0 ppb
2014-06-03WA97-SE1-14-10122-24342ND
2014-06-03WA97-SE1-14-10122-24345ND
2014-06-03WA97-SE1-14-10122-24340ND
2014-06-03WA97-SE1-14-10122-24341ND
2014-09-09WA97-SE2-14-17859-40876ND
2014-09-09WA97-SE2-14-17859-40877ND
2014-09-09WA97-SE2-14-17859-4087534.0 ppb
2014-09-09WA97-SE2-14-17859-40878ND
2014-12-02WA97-SE3-14-23659-53705ND
2014-12-02WA97-SE3-14-23659-53709ND
2014-12-02WA97-SE3-14-23659-53707ND
2014-12-02WA97-SE3-14-23659-53706ND
2014-12-02WA97-SE3-14-23659-53708ND
2014-12-02WA97-SE3-14-23659-53710ND
2015-01-13WA97-SE2-15-00789-1996ND
2015-01-13WA97-SE3-15-00789-1996ND
2015-02-24WA97-SE4-15-03525-8154ND
2015-03-10WA97-SE4-15-04495-10284ND
2015-03-10WA97-SE4-15-04495-10285ND
2015-03-10WA97-SE4-15-04495-10286ND