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EWG's Tap Water Database — 2021 UPDATE

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Nitrite

Norwalk City

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.

 

51

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND120ND
2015ND120ND
2016ND120ND
2017ND120ND
2018ND30ND
2019N/A00N/A

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
2014-01-15AG62884ND
2014-02-12AG64524ND
2014-03-05AG65768ND
2014-04-02AG67508ND
2014-05-07AG70041ND
2014-06-04AG72190ND
2014-07-02AG74561ND
2014-08-06AG77082ND
2014-09-03AG79537ND
2014-10-08AG82469ND
2014-11-05AG84394ND
2014-12-03AG86460ND
2015-01-07AG88645ND
2015-02-04AG90153ND
2015-03-04AG91760ND
2015-04-01AG93591ND
2015-05-13AG96407ND
2015-06-03AG97778ND
2015-07-08AH00610ND
2015-08-05AH02699ND
2015-09-02AH04987ND
2015-10-07AH07447ND
2015-11-04AH09317ND
2015-12-02AH11125ND
2016-01-06AH13089ND
2016-02-03AH14724ND
2016-03-02AH16437ND
2016-04-06AH18799ND
2016-05-04AH20801ND
2016-06-08AH23381ND
2016-07-13AH25927ND
2016-08-03AH27389ND
2016-09-07AH30110ND
2016-10-05AH32792ND
2016-11-02AH34981ND
2016-12-07AH37625ND
2017-01-11AH40302ND
2017-02-01AH42069ND
2017-03-01AH44130ND
2017-04-05AH46503ND
2017-05-03AH48833ND
2017-06-07AH51408ND
2017-07-05AH53781ND
2017-08-02AH56154ND
2017-09-06AH59049ND
2017-10-04AH61408ND
2017-11-08AH63906ND
2017-12-06AH65866ND
2018-01-03AH67429ND
2018-02-14AH70126ND
2018-07-1018-23938-05ND