EWG's Tap Water Database — 2019 UPDATE



City of Donna

Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. 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
20120.130 ppm110.130 ppm
20130.135 ppm220.120 ppm - 0.150 ppm
20140.855 ppm220.830 ppm - 0.880 ppm
20150.530 ppm110.530 ppm
20160.630 ppm110.630 ppm
20170.790 ppm110.790 ppm

ppm = parts per million

State and national drinking water standards and health guidelines

EWG Health Guideline 0.14 ppm

The EWG Health Guideline of 0.14 ppm for nitrate was defined by EWG . This health guideline protects against cancer and harm to fetal growth and development.

EPA Maximum Contaminant
Level (MCL) 10 ppm

The legal limit for nitrate, established in 1962, was developed to protect infants from acute methemoglobinemia, a life-threatening disorder of oxygen transport in the body. This limit does not fully protect against the risk of cancer and harm to the developing fetus.

ppm = parts per million

All test results

Date Lab ID Result
2012-01-3112020420010.130 ppm
2013-04-16AC167260.120 ppm
2013-07-23AC254500.150 ppm
2014-01-29AC405810.880 ppm
2014-01-29AC405720.830 ppm
2015-01-21AC770030.530 ppm
2016-03-02AD265350.630 ppm
2017-01-10AD638170.790 ppm