EWG's Tap Water Database — 2019 UPDATE


Nitrate and nitrite

Tate-Monroe Water Association PWS

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
20120.280 ppm220.250 ppm - 0.310 ppm
20130.375 ppm220.220 ppm - 0.530 ppm
20140.405 ppm220.170 ppm - 0.640 ppm
20150.480 ppm220.190 ppm - 0.770 ppm
20160.475 ppm220.250 ppm - 0.700 ppm
20170.275 ppm220.190 ppm - 0.360 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
2012-01-3112-11123-010.250 ppm
2012-01-3112-11125-01A0.310 ppm
2013-01-2813-11079-01A0.530 ppm
2013-01-2813-11078-010.220 ppm
2014-02-1214-11751-01A0.170 ppm
2014-02-1214-11749-01A0.640 ppm
2015-01-1415-10536-01A0.190 ppm
2015-01-1415-10535-01A0.770 ppm
2016-03-1416-13690-010.250 ppm
2016-03-1416-13691-01A0.700 ppm
2017-01-3117-11690-01A0.190 ppm
2017-01-3117-11691-01A0.360 ppm