Nitrate and nitrite

San Gabriel Valley Water Company - Fontana

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

118

Samples

Samples exceeding legal limit (MCL)

117

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	3.66 ppm	27	27	0.590 ppm - 11.0 ppm
2015	3.90 ppm	26	26	0.700 ppm - 12.0 ppm
2016	3.81 ppm	21	21	0.660 ppm - 8.80 ppm
2017	3.22 ppm	23	23	0.780 ppm - 8.10 ppm
2018	3.85 ppm	18	18	0.550 ppm - 7.90 ppm
2019	4.20 ppm	3	2	ND - 7.50 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
2014-01-08	9588-003-1130	0.590 ppm
2014-01-10	9588-001-1045	0.700 ppm
2014-01-22	9588-022-1145	0.930 ppm
2014-01-22	9588-023-1030	0.740 ppm
2014-01-22	9588-028-1110	0.780 ppm
2014-03-05	9588-020-1120	1.60 ppm
2014-03-19	9588-006-0910	1.20 ppm
2014-03-19	9588-007-1000	1.40 ppm
2014-03-26	9588-011-0900	3.70 ppm
2014-04-16	9588-043-0850	4.80 ppm
2014-04-16	9588-044-1100	3.10 ppm
2014-04-16	9588-045-1010	1.60 ppm
2014-04-16	9588-064-0920	4.60 ppm
2014-04-17	9588-014-0835	11.0 ppm
2014-04-17	9588-031-0745	2.20 ppm
2014-05-21	9588-063-0725	2.80 ppm
2014-05-27	9588-040-1245	8.40 ppm
2014-06-10	9588-038-0850	4.10 ppm
2014-06-24	9588-033-0800	6.30 ppm
2014-06-24	9588-042-0830	6.20 ppm
2014-07-09	9588-065-0850	5.20 ppm
2014-07-09	9588-067-1100	6.00 ppm
2014-07-09	9588-068-1000	5.10 ppm
2014-07-23	9588-026-0740	5.80 ppm
2014-07-23	9588-034-0945	4.80 ppm
2014-07-23	9588-072-0910	3.90 ppm
2014-08-06	9588-027-1020	1.20 ppm
2015-01-30	9588-001-0815	0.930 ppm
2015-01-30	9588-003-0915	0.700 ppm
2015-01-30	9588-011-1050	3.70 ppm
2015-01-30	9588-022-0750	1.000 ppm
2015-01-30	9588-023-0845	0.920 ppm
2015-01-30	9588-027-1030	1.20 ppm
2015-02-26	9588-007-0855	1.30 ppm
2015-02-26	9588-020-0820	1.50 ppm
2015-02-26	9588-028-0745	0.920 ppm
2015-03-12	9588-031-0800	2.10 ppm
2015-03-12	9588-044-0900	2.40 ppm
2015-03-12	9588-045-0740	1.50 ppm
2015-03-23	9588-043-0810	4.80 ppm
2015-03-23	9588-064-0750	6.90 ppm
2015-04-27	9588-026-0840	5.60 ppm
2015-05-11	9588-038-1015	4.00 ppm
2015-05-11	9588-040-1045	8.40 ppm
2015-05-13	9588-033-0945	6.20 ppm
2015-05-13	9588-042-0900	5.20 ppm
2015-05-18	9588-065-0900	5.90 ppm
2015-05-18	9588-068-0945	4.80 ppm
2015-06-10	9588-067-0730	5.80 ppm
2015-06-15	9588-034-0800	5.70 ppm
2015-06-15	9588-072-0740	3.80 ppm
2015-08-19	9588-014-1030	12.0 ppm
2015-10-26	9588-063-1000	4.10 ppm
2016-01-25	9588-001-1030	1.000 ppm
2016-01-25	9588-003-0910	0.660 ppm
2016-02-17	9588-007-0925	1.30 ppm
2016-02-17	9588-022-0900	1.10 ppm
2016-02-17	9588-023-0850	0.970 ppm
2016-02-17	9588-028-0830	0.940 ppm
2016-02-17	9588-043-1030	4.70 ppm
2016-02-17	9588-063-1005	2.90 ppm
2016-02-17	9588-064-1020	6.00 ppm
2016-03-14	9588-026-1100	5.80 ppm
2016-03-14	9588-038-0920	4.30 ppm
2016-03-14	9588-040-0900	8.80 ppm
2016-03-14	9588-068-0950	4.50 ppm
2016-05-04	9588-065-0745	6.10 ppm
2016-05-16	9588-067-1020	4.90 ppm
2016-05-23	9588-027-0910	1.20 ppm
2016-06-23	9588-033-0950	4.00 ppm
2016-06-23	9588-042-1010	3.90 ppm
2016-06-30	9588-034-0820	4.80 ppm
2016-06-30	9588-072-0810	4.40 ppm
2016-11-29	9588-035-0930	7.70 ppm
2017-02-01	9588-001-0935	0.880 ppm
2017-02-01	9588-003-0810	0.780 ppm
2017-02-07	9588-007-1030	1.20 ppm
2017-02-07	9588-027-1000	1.20 ppm
2017-02-07	9588-028-0930	1.30 ppm
2017-02-23	9588-020-1030	0.940 ppm
2017-02-23	9588-022-1040	2.00 ppm
2017-02-23	9588-023-1020	0.930 ppm
2017-02-24	9588-026-0830	8.10 ppm
2017-02-24	9588-043-0920	4.40 ppm
2017-02-24	9588-063-0930	2.80 ppm
2017-02-24	9588-064-0910	7.60 ppm
2017-03-31	9588-006-1010	1.10 ppm
2017-05-08	9588-011-1105	3.90 ppm
2017-06-13	9588-033-1000	2.80 ppm
2017-06-13	9588-042-0945	4.80 ppm
2017-06-19	9588-034-0910	5.20 ppm
2017-06-19	9588-072-0850	4.30 ppm
2017-07-26	9588-038-0830	2.60 ppm
2017-08-07	9588-067-1100	6.90 ppm
2017-09-14	9588-031-1320	2.10 ppm
2017-09-14	9588-044-1420	6.50 ppm
2017-09-14	9588-045-1340	1.70 ppm
2018-01-19	9588-076-0800	0.550 ppm
2018-03-12	9588-023-0940	0.650 ppm
2018-03-15	9588-006-1110	1.20 ppm
2018-03-15	9588-007-0810	1.40 ppm
2018-03-15	9588-020-0730	1.60 ppm
2018-03-26	9588-043-0950	4.90 ppm
2018-04-09	9588-040-1030	7.30 ppm
2018-05-21	9588-063-0840	4.00 ppm
2018-06-11	9588-034-1030	5.30 ppm
2018-06-11	9588-068-0947	5.20 ppm
2018-06-11	9588-072-1020	4.40 ppm
2018-06-25	9588-065-0900	7.20 ppm
2018-07-05	9588-028-0750	0.710 ppm
2018-07-09	9588-033-1140	6.80 ppm
2018-07-17	9588-042-0954	6.30 ppm
2018-07-17	9588-067-1030	7.90 ppm
2018-07-30	9588-031-0800	2.00 ppm
2018-07-30	9588-045-0730	1.80 ppm
2019-01-02	9588-076-1000	ND
2019-06-17	9588-064-0915	7.50 ppm
2019-07-11	9588-043-0810	5.10 ppm