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EWG's Tap Water Database — 2019 UPDATE

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Chlorate

Northampton Bucks County Municipal Authority

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.

 

46

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012N/A00N/A
2013N/A00N/A
2014N/A00N/A
201578.1 ppb4634ND - 200.0 ppb
2016N/A00N/A
2017N/A00N/A

ppb = parts per billion

State and national drinking water standards and health guidelines

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
2015-02-1200111 02201538.0 ppb
2015-02-1200109 022015150.0 ppb
2015-02-1200112 022015ND
2015-02-1200110 022015ND
2015-02-1200114 022015110.0 ppb
2015-02-1200001 022015130.0 ppb
2015-02-1200115 022015ND
2015-02-1200113 02201529.0 ppb
2015-02-1200107 02201540.0 ppb
2015-02-1299001 022015130.0 ppb
2015-02-1200108 022015ND
2015-02-1200106 02201599.0 ppb
2015-02-1800104 022015110.0 ppb
2015-02-1800105 022015ND
2015-02-1800102 022015ND
2015-02-1800103 02201572.0 ppb
2015-02-1899001 022015 UCM200.0 ppb
2015-02-1899001 022015 UCM150.0 ppb
2015-02-1899001 022015 UCM150.0 ppb
2015-02-1800101 02201595.0 ppb
2015-02-1800010 022015110.0 ppb
2015-05-1200001 072015140.0 ppb
2015-05-1200010 072015150.0 ppb
2015-08-1800113 0815ND
2015-08-1800112 0815ND
2015-08-1800010 0815150.0 ppb
2015-08-1800001 0815150.0 ppb
2015-08-1800115 0815ND
2015-08-180010 081556.0 ppb
2015-08-1899001 0815120.0 ppb
2015-08-1800104 081578.0 ppb
2015-08-1800114 081557.0 ppb
2015-08-1800102 0815ND
2015-08-1800103 081572.0 ppb
2015-08-2599001.0815180.0 ppb
2015-08-2599001 0815170.0 ppb
2015-08-2500106 081572.0 ppb
2015-08-2599001_081572.0 ppb
2015-08-2500111 081534.0 ppb
2015-08-2500109 0815140.0 ppb
2015-08-2500108 0815ND
2015-08-2500110 0815ND
2015-08-2500105 081523.0 ppb
2015-08-2500107 081556.0 ppb
2015-11-1700010 1115120.0 ppb
2015-11-1700001 1115140.0 ppb