EWG's Tap Water Database — 2019 UPDATE


Nitrate and nitrite

Doyon Utilities Jber - Richardson

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.





Samples exceeding legal limit (MCL)


Samples exceeding
health guidelines

Testing results - average by year

YearAverage resultSamples takenDetectionsRange of results
20120.525 ppm440.300 ppm - 0.600 ppm
20130.575 ppm440.400 ppm - 0.700 ppm
20140.467 ppm330.300 ppm - 0.600 ppm
20150.467 ppm330.300 ppm - 0.600 ppm
20160.367 ppm330.200 ppm - 0.500 ppm
20170.520 ppm110.520 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
2012-01-03IN*25737540.600 ppm
2012-01-03IN*25737550.600 ppm
2012-01-03IN*25737560.600 ppm
2012-01-03IN*25737530.300 ppm
2013-01-15IN*27667670.400 ppm
2013-01-15IN*27667710.600 ppm
2013-01-15IN*27667720.600 ppm
2013-01-15IN*27667730.700 ppm
2014-01-06IN*29550290.500 ppm
2014-01-06IN*29550310.600 ppm
2014-01-06IN*29550270.300 ppm
2015-01-12IN*31713650.300 ppm
2015-01-12IN*31713670.500 ppm
2015-01-12IN*31713680.600 ppm
2016-04-11IN*34297830.200 ppm
2016-04-11IN*34297920.400 ppm
2016-04-11IN*34297970.500 ppm
2017-01-09IN*PEF316330.520 ppm