Nitrate and nitrite

Marshall Waterworks

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	0.280 ppm	4	1	ND - 1.12 ppm
2015	0.780 ppm	2	1	ND - 1.56 ppm
2016	0.328 ppm	4	1	ND - 1.31 ppm
2017	0.458 ppm	4	2	ND - 1.49 ppm
2018	0.353 ppm	4	2	ND - 1.09 ppm
2019	0.273 ppm	4	1	ND - 1.09 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
2014-07-08	E140601322	ND
2014-07-08	E140601330	1.12 ppm
2014-10-28	E140802407	ND
2014-10-28	E140802399	ND
2015-07-14	VA010-DCLS	1.56 ppm
2015-07-14	VA010-DCLS	ND
2016-07-12	E160608123	1.31 ppm
2016-07-12	E160608118	ND
2016-12-01	E160901675	ND
2016-12-01	E160901672	ND
2017-07-31	E170600337	1.49 ppm
2017-07-31	E170600343	ND
2017-12-06	E170805507	0.340 ppm
2017-12-06	E170805499	ND
2018-07-23	E180606187	1.09 ppm
2018-07-23	E180606188	ND
2018-11-28	E180905389	ND
2018-11-28	E180905390	0.320 ppm
2019-07-10	E190606452	ND
2019-07-10	E190606454	1.09 ppm
2019-11-19	E190906271	ND
2019-11-19	E190906272	ND