Nitrite

Wilmington Water Department

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.

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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	N/A	0	0	N/A
2015	0.0134 ppm	17	2	ND - 0.121 ppm
2016	ND	14	0	ND
2017	0.0148 ppm	20	3	ND - 0.147 ppm
2018	0.0461 ppm	19	14	ND - 0.432 ppm
2019	0.0157 ppm	15	5	ND - 0.0950 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	Result
2015-08-19	ND
2015-09-02	ND
2015-09-02	ND
2015-09-02	ND
2015-09-02	ND
2015-09-02	ND
2015-09-02	ND
2015-09-02	ND
2015-09-02	ND
2015-09-02	ND
2015-09-04	ND
2015-09-09	ND
2015-09-09	0.121 ppm
2015-09-09	0.106 ppm
2015-09-09	ND
2015-09-09	ND
2015-09-29	ND
2016-09-01	ND
2016-09-08	ND
2016-09-08	ND
2016-09-08	ND
2016-09-08	ND
2016-09-08	ND
2016-09-08	ND
2016-09-08	ND
2016-09-08	ND
2016-09-08	ND
2016-09-08	ND
2016-09-08	ND
2016-09-08	ND
2016-09-08	ND
2017-08-31	ND
2017-08-31	ND
2017-08-31	ND
2017-08-31	ND
2017-08-31	ND
2017-08-31	ND
2017-08-31	ND
2017-08-31	ND
2017-08-31	ND
2017-08-31	ND
2017-08-31	ND
2017-08-31	ND
2017-08-31	ND
2017-08-31	ND
2017-08-31	0.0900 ppm
2017-08-31	0.0590 ppm
2017-08-31	ND
2017-08-31	ND
2017-08-31	0.147 ppm
2017-08-31	ND
2018-07-11	0.0125 ppm
2018-07-11	0.0113 ppm
2018-07-11	0.0166 ppm
2018-07-11	ND
2018-07-11	0.0103 ppm
2018-07-11	0.0219 ppm
2018-07-11	0.0634 ppm
2018-07-11	0.0304 ppm
2018-07-11	ND
2018-07-11	0.432 ppm
2018-07-11	0.0107 ppm
2018-07-11	0.0139 ppm
2018-07-11	0.106 ppm
2018-07-11	0.0117 ppm
2018-07-18	0.123 ppm
2018-07-18	0.0114 ppm
2018-07-18	ND
2018-07-18	ND
2018-07-18	ND
2019-07-10	ND
2019-07-10	ND
2019-07-10	ND
2019-07-10	ND
2019-07-10	0.0950 ppm
2019-07-10	ND
2019-07-10	0.0650 ppm
2019-07-10	0.01000 ppm
2019-07-10	0.0210 ppm
2019-07-10	0.0440 ppm
2019-07-10	ND
2019-07-10	ND
2019-07-10	ND
2019-07-10	ND
2019-08-12	ND