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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

University Of Notre Dame

Nitrate and nitrite enter water from fertilizer runoff, septic tanks and urban runoff. These contaminants can cause oxygen deprivation for infants and increase the risk of cancer. Nitrite is significantly more toxic than nitrate. Click here to read more about nitrate.

MORE ABOUT THIS CONTAMINANT

 

28

Samples

0

Samples exceeding legal limit (MCL)

13

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.317 ppm64ND - 1.20 ppm
2015N/A00N/A
2016ND10ND
20170.263 ppm75ND - 0.990 ppm
20180.200 ppm72ND - 0.700 ppm
20190.279 ppm76ND - 0.910 ppm

ppm = parts per million

State and national drinking water standards and health guidelines

EWG Health Guideline 0.14 ppm

The health guideline of 0.14 parts per million, or ppm, for nitrate and nitrite is based on the equivalent health guideline for nitrate, as defined in a peer-reviewed scientific study by EWG. This guideline represents a one-in-one-million annual cancer risk level.

EPA Maximum Contaminant
Level (MCL) 10 ppm

ppm = parts per million

All test results

Date Lab ID Result
2014-06-03318631-02N1.20 ppm
2014-06-03318631-03N0.1000 ppm
2014-06-03318631-04NND
2014-06-03318631-05N0.1000 ppm
2014-06-03318631-06NND
2014-06-03318631-01N0.500 ppm
2016-05-123447085NND
2017-12-1917122285004AN0.150 ppm
2017-12-1917122285007ANND
2017-12-1917122285005AN0.1000 ppm
2017-12-1917122285003ANND
2017-12-1917122285002AN0.410 ppm
2017-12-1917122285001AN0.990 ppm
2017-12-19171222850006AN0.190 ppm
2018-10-1618102092009N0.700 ppm
2018-10-1618102092006NND
2018-10-1618102092004NND
2018-10-16181020920047ND
2018-10-1618102092003NND
2018-10-1618102092002NND
2018-10-1618102092001N0.700 ppm
2019-12-0419120394007N0.170 ppm
2019-12-0419120394006N0.120 ppm
2019-12-0419120394005N0.180 ppm
2019-12-0419120394004N0.180 ppm
2019-12-0419120394003NND
2019-12-0419120394002N0.390 ppm
2019-12-0419120394001N0.910 ppm