Nitrate

California Water Service (CWS) - King City

Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. Click here to read more about nitrate.

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Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2013	N/A	0	0	N/A
2014	2.90 ppm	9	9	0.420 ppm - 5.88 ppm
2015	3.05 ppm	11	11	0.440 ppm - 6.33 ppm
2016	4.08 ppm	9	9	0.498 ppm - 6.95 ppm
2017	3.28 ppm	11	11	0.539 ppm - 6.30 ppm
2018	2.54 ppm	12	12	0.825 ppm - 4.79 ppm
2019	3.11 ppm	9	9	1.00 ppm - 5.02 ppm

ppm = parts per million

State and national drinking water standards and health guidelines

EWG Health Guideline 0.14 ppm

The EWG Health Guideline of 0.14 ppm for nitrate was defined by EWG . This health guideline protects against cancer and harm to fetal growth and development.

EPA Maximum Contaminant
Level (MCL) 10 ppm

The legal limit for nitrate, established in 1962, was developed to protect infants from acute methemoglobinemia, a life-threatening disorder of oxygen transport in the body. This limit does not fully protect against the risk of cancer and harm to the developing fetus.

ppm = parts per million

All test results

Date	Lab ID	Result
2014-03-17	5701-012-1111	1.45 ppm
2014-03-17	5701-006-1406	0.882 ppm
2014-03-19	5701-007-1104	5.05 ppm
2014-06-04	9590-015-0930	0.633 ppm
2014-06-11	5701-007-1415	5.19 ppm
2014-06-17	5701-008-1322	0.420 ppm
2014-07-16	5701-014-1130	1.32 ppm
2014-09-16	5701-007-1150	5.24 ppm
2014-12-17	5701-007-1445	5.88 ppm
2015-02-18	9590-014-1235	1.76 ppm
2015-03-16	5701-006-1015	0.879 ppm
2015-03-16	5701-012-1205	2.53 ppm
2015-03-16	5701-007-1433	6.17 ppm
2015-06-08	5701-007-1400	5.95 ppm
2015-06-08	5701-015-1203	0.627 ppm
2015-06-09	9590-008-1110	0.452 ppm
2015-06-09	9590-008-1110	0.440 ppm
2015-07-22	5701-014-1104	2.27 ppm
2015-09-10	9590-007-1233	6.33 ppm
2015-12-02	5701-007-1412	6.18 ppm
2016-03-02	5701-007-1331	6.47 ppm
2016-03-07	9590-012-1150	4.20 ppm
2016-03-08	9590-006-1008	1.50 ppm
2016-06-15	5701-007-1237	6.95 ppm
2016-06-15	5701-008-1430	0.498 ppm
2016-06-20	5701-015-1345	0.774 ppm
2016-06-20	5701-014-1317	3.74 ppm
2016-09-19	5701-007-1046	6.43 ppm
2016-12-13	5701-007-1318	6.15 ppm
2017-03-14	5701-007-1100	6.30 ppm
2017-03-14	5701-012-1312	3.07 ppm
2017-03-15	5701-006-1336	2.94 ppm
2017-06-08	9590-015-1216	0.660 ppm
2017-06-13	5701-014-1105	2.44 ppm
2017-06-13	5701-007-1155	5.77 ppm
2017-06-13	5701-008-1400	0.539 ppm
2017-09-18	5701-007-1230	4.88 ppm
2017-11-20	9590-015-1130	0.850 ppm
2017-12-12	5701-007-1000	4.28 ppm
2017-12-19	5701-007-1058	4.30 ppm
2018-02-08	9590-014-1125	1.40 ppm
2018-02-21	5701-006-1030	1.51 ppm
2018-02-21	5701-007-1410	4.10 ppm
2018-02-21	5701-008-1450	0.908 ppm
2018-03-14	5701-012-1525	1.68 ppm
2018-03-14	5701-014-1324	1.53 ppm
2018-03-14	5701-015-1411	0.825 ppm
2018-05-15	5701-007-1405	3.91 ppm
2018-07-17	9590-008-1113	1.000 ppm
2018-08-15	5701-007-1114	4.45 ppm
2018-09-17	9590-007-1300	4.40 ppm
2018-11-28	5701-007-1158	4.79 ppm
2019-02-13	5701-007-1240	4.93 ppm
2019-02-13	5701-008-1203	1.21 ppm
2019-03-19	5701-014-1102	1.49 ppm
2019-03-19	5701-015-1043	1.00 ppm
2019-03-20	9590-012-1145	2.30 ppm
2019-04-17	9590-006-1201	2.50 ppm
2019-05-14	5701-007-1401	5.02 ppm
2019-08-21	5701-007-0927	4.99 ppm
2019-11-19	5701-007-1111	4.56 ppm