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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

Montgomery County Regional Public Water Authority

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.

 

7

Samples

0

Samples exceeding legal limit (MCL)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND10ND
2015ND10ND
2016ND10ND
20170.140 ppm110.140 ppm
2018ND10ND
20190.140 ppm21ND - 0.280 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
2014-08-25Y142400009ND
2015-08-25Y152390025ND
2016-08-29Y162450004ND
2017-08-21Y1723600250.140 ppm
2018-09-04Y182500002ND
2019-08-07Y1922000110.280 ppm
2019-08-26Y192410018ND