EWG's Tap Water Database — 2019 UPDATE


Nitrate and nitrite

Fort Bend County MUD 25

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
20120.103 ppm330.01000 ppm - 0.150 ppm
20130.103 ppm330.01000 ppm - 0.160 ppm
20140.0700 ppm220.01000 ppm - 0.130 ppm
20150.150 ppm220.130 ppm - 0.170 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
2012-03-20AB844780.01000 ppm
2012-03-20AB844790.150 ppm
2012-03-20AB844810.150 ppm
2013-02-28AC118760.01000 ppm
2013-02-28AC118770.140 ppm
2013-02-28AC118710.160 ppm
2014-01-16AC391900.01000 ppm
2014-01-16AC391850.130 ppm
2015-02-04AC791210.130 ppm
2015-02-04AC791200.170 ppm