Nitrate and nitrite

Warrenton PWS

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	0.0200 ppm	4	4	0.0150 ppm - 0.0240 ppm
2015	0.00550 ppm	4	1	ND - 0.0220 ppm
2016	0.0270 ppm	4	4	0.0200 ppm - 0.0320 ppm
2017	0.0258 ppm	4	4	0.0230 ppm - 0.0280 ppm
2018	0.0310 ppm	4	4	0.0240 ppm - 0.0360 ppm
2019	0.0300 ppm	4	4	0.0270 ppm - 0.0340 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	AC17140	0.0190 ppm
2014-01-27	AC17141	0.0240 ppm
2014-01-27	AC17142	0.0220 ppm
2014-01-27	AC17139	0.0150 ppm
2015-09-02	AC57918	ND
2015-09-02	AC57917	ND
2015-09-02	AC57919	0.0220 ppm
2015-09-02	AC57920	ND
2016-08-15	AC82133	0.0200 ppm
2016-08-15	AC82131	0.0260 ppm
2016-08-15	AC82130	0.0300 ppm
2016-08-15	AC82132	0.0320 ppm
2017-08-24	AD03765	0.0230 ppm
2017-08-24	AD03764	0.0280 ppm
2017-08-24	AD03763	0.0280 ppm
2017-08-24	AD03762	0.0240 ppm
2018-08-21	AD30887	0.0360 ppm
2018-08-21	AD30888	0.0240 ppm
2018-08-21	AD30889	0.0340 ppm
2018-08-21	AD30890	0.0300 ppm
2019-08-27	AD53701	0.0270 ppm
2019-08-27	AD53702	0.0340 ppm
2019-08-27	AD53703	0.0320 ppm
2019-08-27	AD53704	0.0270 ppm