Know Your Environment. Protect Your Health.

Nitrate

Northwest Harris County Municipal Utility District 21

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.

 

18

Samples

0

Samples exceeding legal limit (MCL)

12

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.620 ppm110.620 ppm
20190.260 ppm110.260 ppm
20200.423 ppm440.120 ppm - 0.800 ppm
20210.513 ppm440.0800 ppm - 1.01 ppm
20220.283 ppm440.0900 ppm - 0.780 ppm
20230.555 ppm440.0800 ppm - 1.01 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
2018-01-11AE088140.620 ppm
2019-06-17AE707720.260 ppm
2020-03-24AF042320.640 ppm
2020-05-21AF122740.800 ppm
2020-08-13AF233290.130 ppm
2020-12-03AF363920.120 ppm
2021-03-09AF458901.01 ppm
2021-04-06AF490920.440 ppm
2021-08-12AF660100.0800 ppm
2021-10-21AF742680.520 ppm
2022-02-03AF831170.780 ppm
2022-05-17AF971070.110 ppm
2022-07-21AG056640.0900 ppm
2022-10-25AG182260.150 ppm
2023-01-12AG242821.01 ppm
2023-04-13AG366710.680 ppm
2023-07-20AG494730.0800 ppm
2023-10-12AG596610.450 ppm