Nitrate and nitrite

Phelan Pinon Hills CSD

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	2.00 ppm	2	1	ND - 4.00 ppm
2015	0.507 ppm	3	3	0.410 ppm - 0.580 ppm
2016	1.000 ppm	6	4	ND - 4.40 ppm
2017	2.30 ppm	2	1	ND - 4.60 ppm
2018	0.507 ppm	3	3	0.440 ppm - 0.540 ppm
2019	0.817 ppm	6	2	ND - 4.30 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
2014-04-17	3761-017-1105	4.00 ppm
2014-06-18	3761-007-0758	ND
2015-02-09	3761-011-0935	0.410 ppm
2015-02-17	3761-002-1035	0.580 ppm
2015-02-17	3761-009-0918	0.530 ppm
2016-04-04	3761-015-0935	4.40 ppm
2016-04-13	3761-006-1050	ND
2016-07-11	3761-005-0900	0.590 ppm
2016-07-19	3761-012-0815	ND
2016-09-08	3761-016-0845	0.470 ppm
2016-12-13	3761-013-0900	0.540 ppm
2017-04-03	3761-017-0930	4.60 ppm
2017-06-12	3761-007-1330	ND
2018-02-05	3761-002-0815	0.540 ppm
2018-02-08	3761-011-1130	0.440 ppm
2018-04-10	3761-009-1100	0.540 ppm
2019-04-02	3761-006-0948	ND
2019-04-02	3761-015-1225	4.30 ppm
2019-07-03	3761-012-0940	ND
2019-07-03	3761-005-1109	0.600 ppm
2019-09-09	3761-016-1030	ND
2019-12-09	3761-013-1142	ND