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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

Hartland Institute

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.

 

6

Samples

0

Samples exceeding legal limit (MCL)

3

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20140.170 ppm110.170 ppm
20150.133 ppm110.133 ppm
20160.115 ppm220.107 ppm - 0.123 ppm
20170.176 ppm110.176 ppm
2018N/A00N/A
20190.220 ppm110.220 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
2014-02-27307180.170 ppm
2015-03-18460160-ANALYTICS0.133 ppm
2016-03-140065512-NIT0.123 ppm
2016-10-260076691NN0.107 ppm
2017-11-090096730-NIT0.176 ppm
2019-11-200140725-NIT0.220 ppm