EWG's Tap Water Database — 2021 UPDATE



Brownsville Water Department

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
20140.425 ppm220.222 ppm - 0.627 ppm
20150.462 ppm220.287 ppm - 0.636 ppm
20160.413 ppm220.220 ppm - 0.605 ppm
20170.458 ppm220.265 ppm - 0.651 ppm
20180.740 ppm220.695 ppm - 0.785 ppm
20190.377 ppm220.219 ppm - 0.535 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 Result
2014-01-200.627 ppm
2014-01-200.222 ppm
2015-02-030.636 ppm
2015-02-030.287 ppm
2016-01-250.605 ppm
2016-01-250.220 ppm
2017-02-130.651 ppm
2017-02-130.265 ppm
2018-02-050.785 ppm
2018-02-050.695 ppm
2019-01-090.535 ppm
2019-01-090.219 ppm