EWG's Tap Water Database — 2021 UPDATE


Nitrate and nitrite

Dewitt WDS - North

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
20140.385 ppm220.190 ppm - 0.580 ppm
20150.505 ppm220.400 ppm - 0.610 ppm
20160.267 ppm21ND - 0.534 ppm
20170.460 ppm440.271 ppm - 0.689 ppm
20180.328 ppm440.200 ppm - 0.590 ppm
20190.525 ppm440.230 ppm - 1.000 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