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.

MORE ABOUT THIS CONTAMINANT

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	0.320 ppm	2	2	0.230 ppm - 0.410 ppm
2015	0.630 ppm	2	2	0.600 ppm - 0.660 ppm
2016	0.670 ppm	2	2	0.650 ppm - 0.690 ppm
2017	0.710 ppm	3	3	0.620 ppm - 0.760 ppm
2018	0.485 ppm	2	2	0.420 ppm - 0.550 ppm
2019	0.915 ppm	2	2	0.590 ppm - 1.24 ppm

ppm = parts per million

State and national drinking water standards and health guidelines

EWG Health Guideline 0.14 ppm

The EWG Health Guideline of 0.14 ppm for nitrate was defined by EWG . This health guideline protects against cancer and harm to fetal growth and development.

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
2014-05-05	AC52771	0.410 ppm
2014-07-25	AC60992	0.230 ppm
2015-02-03	AC78906	0.660 ppm
2015-02-03	AC78907	0.600 ppm
2016-02-02	AD21300	0.690 ppm
2016-02-02	AD21301	0.650 ppm
2017-04-26	AD81052	0.620 ppm
2017-07-10	AD88601	0.760 ppm
2017-07-10	AD88585	0.750 ppm
2018-01-24	AE10027	0.550 ppm
2018-01-24	AE10025	0.420 ppm
2019-01-11	AE49425	0.590 ppm
2019-02-20	AE54973	1.24 ppm