Know Your Environment. Protect Your Health.

Chlorate

Parkland Light & Water Company

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
2013ND100ND
2014ND140ND
2015N/A00N/A
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
2013-10-14201310150087AMND
2013-10-14201310150065AMND
2013-10-14201310150077AMND
2013-10-14201310150101AMND
2013-10-14201310150081AMND
2013-10-14201310150041AMND
2013-10-15201310160198AMND
2013-10-15201310160202AMND
2013-10-15201310160196AMND
2013-10-15201310160194AMND
2014-04-01201404020528AMND
2014-04-01201404020442AMND
2014-04-01201404020435AMND
2014-04-01201404020449AMND
2014-04-03201404040355AMND
2014-04-03201404040294AMND
2014-04-03201404040258AMND
2014-04-03201404040256AMND
2014-04-03201404040254AMND
2014-04-03201404040307AMND
2014-04-07201404080583AMND
2014-04-07201404080577AMND
2014-10-02201410030196AMND
2014-10-02201410030192AMND