Nitrite

Denton County Fresh Water Supply District 1-a Castle Hills

Nitrite, closely related to the fertilizer chemical nitrate, comes from urban runoff and from fertilizer applied to agricultural lands to pollute drinking water. Nitrite is significantly more toxic than nitrate. Excessive nitrite in water can cause oxygen deprivation in infants and increase the risk of cancer.

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	0.119 ppm	5	3	ND - 0.352 ppm
2015	0.0505 ppm	5	2	ND - 0.230 ppm
2016	0.0515 ppm	4	2	ND - 0.136 ppm
2017	0.0370 ppm	4	3	ND - 0.0572 ppm
2018	0.106 ppm	4	3	ND - 0.307 ppm
2019	0.0127 ppm	4	2	ND - 0.0301 ppm

ppm = parts per million

State and national drinking water standards and health guidelines

EPA Maximum Contaminant
Level (MCL) 1 ppm

The legal limit for nitrite, established in 1991, was based on the rate of conversion of ingested nitrate into nitrite in adults. This limit may not fully protect against the risk of cancer due to nitrite exposure.

ppm = parts per million

All test results

Date	Lab ID	Result
2014-02-25	Q1406116002	ND
2014-02-25	Q1406116003	ND
2014-06-24	Q1423351003	0.00650 ppm
2014-09-09	Q1442738003	0.234 ppm
2014-11-12	Q1455687003	0.352 ppm
2015-03-04	Q1508287002	ND
2015-03-04	Q1508287005	ND
2015-06-11	Q1521540001	0.0225 ppm
2015-09-10	Q1535137001	0.230 ppm
2015-11-23	Q1546241001	ND
2016-03-31	Q1612985001	ND
2016-04-26	Q1616453001	ND
2016-09-01	Q1635097001	0.136 ppm
2016-10-18	Q1644228001	0.0700 ppm
2017-01-26	Q1703698004	0.0410 ppm
2017-05-09	Q1718886001	0.0497 ppm
2017-08-01	Q1731639001	0.0572 ppm
2017-10-25	Q1754813003	ND
2018-02-13	Q1805970003	ND
2018-05-07	Q1818240001	0.0615 ppm
2018-08-07	Q1831302001	0.0538 ppm
2018-11-05	Q1844084002	0.307 ppm
2019-02-28	Q1908666001	ND
2019-06-18	Q1937114001	0.0205 ppm
2019-09-25	Q1968834001	0.0301 ppm
2019-12-12	Q1979971004	ND