Know Your Environment. Protect Your Health.

Nitrate

Harris County Municipal Utility District 421

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.

 

6

Samples

0

Samples exceeding legal limit (MCL)

5

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.790 ppm110.790 ppm
20190.500 ppm110.500 ppm
20200.770 ppm110.770 ppm
20210.300 ppm110.300 ppm
20220.140 ppm110.140 ppm
20230.210 ppm110.210 ppm

ppm = parts per million

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.14 ppm

The EWG 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

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
2018-05-24AE276120.790 ppm
2019-08-29AE815170.500 ppm
2020-08-06AF222100.770 ppm
2021-09-07AF688990.300 ppm
2022-09-16AG133700.140 ppm
2023-07-24AG497270.210 ppm