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EWG's Tap Water Database — 2021 UPDATE

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Nitrate and nitrite

Rison Waterworks

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.

 

14

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND20ND
2015ND20ND
2016ND30ND
2017ND20ND
2018ND20ND
2019ND30ND

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
2014-02-05140370014ND
2014-08-12142260011ND
2015-03-16Y150780007ND
2015-07-27Y152110010ND
2016-01-25Y160280012ND
2016-03-03Y160640002ND
2016-09-12Y162590009ND
2017-01-16Y170190012ND
2017-07-24Y172080025ND
2018-03-13Y180740015ND
2018-07-23Y182080022ND
2019-01-22Y190240008ND
2019-01-22Y190240007ND
2019-07-22Y192060001ND