Nitrate and nitrite

City of Horn Lake

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.

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
2013	N/A	0	0	N/A
2014	0.0675 ppm	4	1	ND - 0.270 ppm
2015	0.0700 ppm	4	1	ND - 0.280 ppm
2016	0.108 ppm	4	1	ND - 0.430 ppm
2017	0.0875 ppm	4	1	ND - 0.350 ppm
2018	0.103 ppm	4	1	ND - 0.410 ppm
2019	0.0975 ppm	4	1	ND - 0.390 ppm

ppm = parts per million

State and national drinking water standards and health guidelines

EWG Health Guideline 0.14 ppm

The 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
2014-01-27	140128-079NI	0.270 ppm
2014-01-27	140128-073NI	ND
2014-01-27	140128-068NI	ND
2014-01-27	140128-065NI	ND
2015-01-26	150127-053NI	ND
2015-01-26	150127-052NI	0.280 ppm
2015-01-26	150127-051NI	ND
2015-11-18	151119-012NI	ND
2016-03-21	160322-045NI	0.430 ppm
2016-03-21	160322-085NI	ND
2016-03-21	160322-047NI	ND
2016-03-21	160322-046NI	ND
2017-01-30	170131-028NI	ND
2017-01-30	170131-014NI	0.350 ppm
2017-01-30	170131-013NI	ND
2017-01-30	170131-001NI	ND
2018-01-29	180130-079NI	0.410 ppm
2018-01-29	180130-078NI	ND
2018-01-29	180130-074NI	ND
2018-01-29	180130-073NI	ND
2019-02-05	190206-004NI	0.390 ppm
2019-02-05	190206-024NI	ND
2019-02-05	190206-013NI	ND
2019-02-05	190206-009NI	ND