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EWG's Tap Water Database — 2019 UPDATE

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Chlorite

City of Black Hawk

Chlorite is a disinfection byproduct resulting from water treatment with chlorine dioxide. Chlorite decreases hemoglobin levels and causes other hematologic effects. Read More.

Chlorite also forms when chlorine dioxide is used as a bleaching agent for textiles, paper pulp, flour and oils, and from the use of chlorine dioxide in food and packaging. In 2009, California published a public health goal of 50 parts per billion for chlorite in drinking water. California state scientists reported that chlorite causes red blood cell damage, affects sperm and thyroid function, and may alter behavior and neurodevelopment of rat pups exposed in the womb.

Click here to read more about disinfection byproducts.

 

73

Samples

0

Samples exceeding legal limit (MCL)

20

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012N/A00N/A
2013N/A00N/A
2014N/A00N/A
201541.4 ppb71ND - 290.0 ppb
201650.8 ppb3610ND - 240.0 ppb
201774.7 ppb3012ND - 370.0 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 50 ppb

The EWG Health Guideline of 50 ppb for chlorite was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against change in blood chemistry.

EPA Maximum Contaminant
Level (MCL) 1,000 ppb

ppb = parts per billion

All test results

Date Result
2015-09-28290.0 ppb
2015-11-05ND
2015-11-05ND
2015-11-05ND
2015-12-21ND
2015-12-21ND
2015-12-21ND
2016-01-05ND
2016-01-05ND
2016-01-05ND
2016-02-10ND
2016-02-1069.0 ppb
2016-02-10ND
2016-03-01ND
2016-03-01ND
2016-03-01ND
2016-04-04ND
2016-04-04ND
2016-04-04ND
2016-05-10ND
2016-05-10ND
2016-05-10ND
2016-06-02220.0 ppb
2016-06-02150.0 ppb
2016-06-02240.0 ppb
2016-07-05220.0 ppb
2016-07-05170.0 ppb
2016-07-05210.0 ppb
2016-08-01160.0 ppb
2016-08-01190.0 ppb
2016-08-01200.0 ppb
2016-09-06ND
2016-09-06ND
2016-09-06ND
2016-10-03ND
2016-10-03ND
2016-10-03ND
2016-11-01ND
2016-11-01ND
2016-11-01ND
2016-12-08ND
2016-12-08ND
2016-12-08ND
2017-01-02ND
2017-01-02ND
2017-01-02ND
2017-04-0311.0 ppb
2017-04-0315.0 ppb
2017-04-03ND
2017-05-02ND
2017-05-02ND
2017-05-02180.0 ppb
2017-06-12ND
2017-06-12ND
2017-06-12150.0 ppb
2017-07-06310.0 ppb
2017-07-06ND
2017-07-06ND
2017-08-02370.0 ppb
2017-08-02280.0 ppb
2017-08-02350.0 ppb
2017-09-12ND
2017-09-12220.0 ppb
2017-09-12ND
2017-10-02ND
2017-10-0273.0 ppb
2017-10-02ND
2017-11-07ND
2017-11-0712.0 ppb
2017-11-07ND
2017-12-05ND
2017-12-05270.0 ppb
2017-12-05ND