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EWG's Tap Water Database — 2021 UPDATE

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Nitrite

Missouri American St. Louis County & St. Charles County

Nitrite, closely related to the fertilizer chemical nitrate, comes from urban runoff and from fertilizer applied to agricultural lands to pollute drinking water. Nitrite is significantly more toxic than nitrate. Excessive nitrite in water can cause oxygen deprivation in infants and increase the risk of cancer.

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35

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
2014ND100ND
2015ND50ND
2016ND50ND
2017ND50ND
2018ND50ND
20190.0200 ppm51ND - 0.1000 ppm

ppm = parts per million

State and national drinking water standards and health guidelines

EPA Maximum Contaminant
Level (MCL) 1 ppm

The legal limit for nitrite, established in 1991, was based on the rate of conversion of ingested nitrate into nitrite in adults. This limit may not fully protect against the risk of cancer due to nitrite exposure.

ppm = parts per million

All test results

Date Lab ID Result
2014-04-1525143301ND
2014-04-1625141501ND
2014-04-1625142401ND
2014-07-2926956301ND
2014-07-2926956401ND
2014-07-2926956501ND
2014-07-2926956601ND
2014-07-2926956701ND
2014-10-0827161901ND
2014-10-0927162201ND
2015-04-2228626601ND
2015-04-2228624801ND
2015-04-2228625701ND
2015-10-2630317501ND
2015-10-2630317801ND
2016-04-0531776401ND
2016-04-0531777401ND
2016-04-2031778401ND
2016-10-0533414601ND
2016-10-0533414301ND
2017-04-1135121801ND
2017-04-1935119801ND
2017-04-1935120801ND
2017-10-1637230401ND
2017-10-1637230701ND
2018-04-1639053401ND
2018-04-2439052501ND
2018-04-2439687101ND
2018-10-0941293301ND
2018-10-0941293601ND
2019-04-0843597701ND
2019-04-0843598601ND
2019-04-0943599401ND
2019-10-0746959201ND
2019-10-07469594010.1000 ppm