Know Your Environment. Protect Your Health.

Nitrate and nitrite

Harris County Water Control and Improvement District 89

NOTE: Harris County Water Control and Improvement District 89 purchases water from City of Houston which is required to test for nitrate and nitrite. Sample information shown below was taken by City of Houston.

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.

 

8

Samples

0

Samples exceeding legal limit (MCL)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018N/A00N/A
2019ND20ND
20200.0483 ppm62ND - 0.180 ppm
2021N/A00N/A
2022N/A00N/A
2023ND10ND

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

NOTE: Harris County Water Control and Improvement District 89 purchases water from City of Houston which is required to test for nitrate and nitrite. Sample information shown below was taken by City of Houston.

Date Lab ID Result
2019-06-25AE71856ND
2019-11-18AE89369ND
2020-11-04AF33154ND
2020-11-04AF33162ND
2020-11-04AF331630.180 ppm
2020-11-05AF333690.110 ppm
2020-11-05AF33370ND
2020-11-05AF33371ND