EWG's Tap Water Database — 2019 UPDATE



Herington, City of

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
20120.710 ppm220.630 ppm - 0.790 ppm
20130.440 ppm220.370 ppm - 0.510 ppm
20140.240 ppm110.240 ppm
20150.335 ppm220.140 ppm - 0.530 ppm
20160.415 ppm220.400 ppm - 0.430 ppm
20170.745 ppm220.390 ppm - 1.10 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
2012-04-11577387BT0.790 ppm
2012-05-08578569WS0.630 ppm
2013-04-09594366BT0.370 ppm
2013-05-06595580WS0.510 ppm
2014-04-221002300.240 ppm
2015-03-172970830.140 ppm
2015-04-203158030.530 ppm
2016-03-145092490.400 ppm
2016-04-185295600.430 ppm
2017-03-137236170.390 ppm
2017-04-177431071.10 ppm