Nitrate and nitrite

New Design - Frederick County

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	N/A	0	0	N/A
2015	4.40 ppm	2	2	1.20 ppm - 7.60 ppm
2016	2.35 ppm	5	5	0.640 ppm - 7.80 ppm
2017	2.91 ppm	7	7	0.0500 ppm - 8.00 ppm
2018	1.65 ppm	4	4	1.10 ppm - 2.19 ppm
2019	1.60 ppm	2	2	1.000 ppm - 2.20 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
2015-04-07	AM04968	1.20 ppm
2015-04-22	AM05687	7.60 ppm
2016-03-16	AN03618	0.900 ppm
2016-04-27	AN05680	1.20 ppm
2016-04-27	AN03618_A	1.20 ppm
2016-04-27	AN05683	7.80 ppm
2016-06-06	E16004629002	0.640 ppm
2017-02-06	AO01703	1.60 ppm
2017-02-09	AN03618	0.0500 ppm
2017-03-09	AO03287	7.90 ppm
2017-04-05	E17003928003	0.850 ppm
2017-04-05	AO01703_A	1.000 ppm
2017-04-05	AO03287_A	8.00 ppm
2017-06-02	AO07391	1.000 ppm
2018-02-21	AP02760	1.10 ppm
2018-03-12	AP03597	1.90 ppm
2018-04-09	AP04907	1.40 ppm
2018-04-12	E18003688001	2.19 ppm
2019-02-28	AQ03031	1.000 ppm
2019-04-01	AQ04624	2.20 ppm