Know Your Environment. Protect Your Health.

Nitrate

Harris County Fresh Water Supply District 1a

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.

 

11

Samples

0

Samples exceeding legal limit (MCL)

10

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.485 ppm220.420 ppm - 0.550 ppm
20190.915 ppm220.590 ppm - 1.24 ppm
20200.400 ppm110.400 ppm
20210.700 ppm220.690 ppm - 0.710 ppm
20220.570 ppm220.0900 ppm - 1.05 ppm
20230.515 ppm220.380 ppm - 0.650 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
2018-01-24AE100250.420 ppm
2018-01-24AE100270.550 ppm
2019-01-11AE494250.590 ppm
2019-02-20AE549731.24 ppm
2020-01-21AE941730.400 ppm
2021-03-08AF455700.710 ppm
2021-03-08AF455730.690 ppm
2022-01-31AF824030.0900 ppm
2022-01-31AF824051.05 ppm
2023-01-31AG265980.380 ppm
2023-06-14AG444080.650 ppm