Nitrate and nitrite

Marion Water System

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
2014	ND	4	0	ND
2015	ND	4	0	ND
2016	0.0305 ppm	4	4	0.0280 ppm - 0.0330 ppm
2017	ND	4	0	ND
2018	ND	4	0	ND
2019	0.0245 ppm	4	2	ND - 0.0490 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
2014-11-17	AD99773	ND
2014-11-17	AD99743	ND
2014-11-17	AD99773	ND
2014-11-17	AD99743	ND
2015-08-24	35204447002	ND
2015-08-24	35204447002	ND
2015-10-01	35210114009	ND
2015-10-01	35210114009	ND
2016-12-01	35280570020	0.0280 ppm
2016-12-01	35280570021	0.0330 ppm
2016-12-01	35280570021	0.0330 ppm
2016-12-01	35280570020	0.0280 ppm
2017-11-06	35346871001	ND
2017-11-06	35346871001	ND
2017-11-06	35346863001	ND
2017-11-06	35346863001	ND
2018-03-15	35380525001	ND
2018-03-15	35380525001	ND
2018-05-14	35392913003	ND
2018-05-14	35392913003	ND
2019-12-06	35519663001	0.0490 ppm
2019-12-06	35519663002	ND
2019-12-06	35519663001	0.0490 ppm
2019-12-06	35519663002	ND