Know Your Environment. Protect Your Health.

Nitrate and nitrite

Harris County Municipal Utility District 23

Nitrate and nitrite enter water from fertilizer runoff, septic tanks and urban runoff. These contaminants can cause oxygen deprivation for infants and increase the risk of cancer. Nitrite is significantly more toxic than nitrate. Click here to read more about nitrate.

 

6

Samples

0

Samples exceeding legal limit (MCL)

4

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.585 ppm220.500 ppm - 0.670 ppm
2019ND10ND
20200.0483 ppm62ND - 0.180 ppm
20210.145 ppm21ND - 0.290 ppm
20220.160 ppm110.160 ppm
2023N/A00N/A

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

ppm = parts per million

All test results

Date Lab ID Result
2018-02-08AE128770.500 ppm
2018-06-26AE313340.670 ppm
2019-02-25AE55539ND
2021-01-13AF38973ND
2021-01-13AF389740.290 ppm
2022-01-25AF814810.160 ppm