EWG's Tap Water Database — 2019 UPDATE


Nitrate and nitrite

Wellborn SUD

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
20121.96 ppm770.0500 ppm - 6.30 ppm
20132.18 ppm220.226 ppm - 4.13 ppm
20140.150 ppm220.140 ppm - 0.160 ppm
20150.235 ppm220.0700 ppm - 0.400 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
2012-02-01AB799160.130 ppm
2012-02-01AB799170.0500 ppm
2012-03-21AB847751.76 ppm
2012-06-18AB930591.57 ppm
2012-06-18AB930550.170 ppm
2012-09-12AC007246.30 ppm
2012-11-0112110940013.72 ppm
2013-02-0613022280024.13 ppm
2013-06-12Q13021830060.226 ppm
2014-02-13AC428580.140 ppm
2014-02-13AC428570.160 ppm
2015-03-24AC857830.400 ppm
2015-03-24AC857840.0700 ppm