Know Your Environment. Protect Your Health.

Chlorate

Firgrove Mutual Inc

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.

 

30

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201446.9 ppb117ND - 100.0 ppb
201515.8 ppb1911ND - 39.0 ppb
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
2014-11-17201411190526AM100.0 ppb
2014-11-17201411190378AM40.0 ppb
2014-11-17201411190437AMND
2014-11-17201411190452AMND
2014-11-17201411190528AM98.0 ppb
2014-11-17201411190454AMND
2014-11-17201411190338AM76.0 ppb
2014-11-17201411190490AMND
2014-11-17201411190450AM74.0 ppb
2014-11-17201411190435AM84.0 ppb
2014-11-17201411190403AM44.0 ppb
2015-01-19201501200178AMND
2015-02-13201502160119AMND
2015-02-13201502160121AM29.0 ppb
2015-03-13201503170797AM30.0 ppb
2015-05-18201505200407AM21.0 ppb
2015-05-18201505200251AM22.0 ppb
2015-05-18201505200247AM20.0 ppb
2015-05-18201505210080AM22.0 ppb
2015-05-18201505200268AM22.0 ppb
2015-05-18201505200262AMND
2015-05-18201505200243AMND
2015-05-18201505200655AMND
2015-05-18201505200274AMND
2015-05-18201505200651AM39.0 ppb
2015-05-18201505200365AMND
2015-05-18201505210076AMND
2015-05-18201505210078AM33.0 ppb
2015-08-21201508250623AM33.0 ppb
2015-08-21201508250571AM30.0 ppb