Atrazine

California Water Service (CWS) - Salinas

Atrazine is a herbicide commonly detected in drinking water that comes from cornfield and other agricultural runoff. It is a hormone disrupter that harms the male and female reproductive systems of people and wildlife. Read More.

Federal laws allow up to 3 parts per billion of atrazine in treated tap water. Water suppliers average atrazine measurements collected over a year, which means that the reported values underestimate intense spikes of elevated exposures during the periods in late spring and early summer when atrazine is applied in large amounts on farm fields.

Human epidemiological studies suggest that federal standards for atrazine are insufficient to protect public health. In 1999 the California Office of Environmental Health Hazard Assessment set a public health goal of 0.15 parts per billion for atrazine in drinking water, based on a study finding increased rates of breast cancer in rats exposed to the chemical. California’s legal maximum for atrazine in tap water is 1 ppb.

Click here to read more about atrazine.

MORE ABOUT THIS CONTAMINANT

115

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Range of results
2014	ND	13	ND
2015	ND	8	ND
2016	ND	22	ND
2017	ND	5	ND
2018	ND	22	ND
2019	ND	45	ND

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.1 ppb

The EWG Health Guideline of 0.1 ppb for atrazine was defined by EWG based on epidemiological studies of human exposure to atrazine in drinking water.. This health guideline protects against harm to the developing fetus, harm to the reproductive system and hormone disruption.

EPA Maximum Contaminant
Level (MCL) 3 ppb

The legal limit for atrazine, established in 1991, was based on a toxicity study in laboratory animals conducted in the 1980s. This limit does not fully protect against harm to the reproductive system, harm to the developing fetus, and hormone disruption.

ppb = parts per billion

All test results

Date	Lab ID	Result
2014-02-12	9590-102-1321	ND
2014-02-12	9590-103-1352	ND
2014-02-12	9590-123-0936	ND
2014-02-19	9590-106-1143	ND
2014-05-07	9590-102-1427	ND
2014-05-07	9590-103-1448	ND
2014-05-13	9590-123-1033	ND
2014-08-04	9590-102-0912	ND
2014-08-04	9590-103-1409	ND
2014-08-04	9590-123-0940	ND
2014-11-12	9590-102-1030	ND
2014-11-12	9590-103-0949	ND
2014-11-12	9590-123-1409	ND
2015-02-07	9590-103-1044	ND
2015-02-07	9590-123-1140	ND
2015-03-10	9590-102-1500	ND
2015-03-10	9590-123-1420	ND
2015-04-21	9590-008-1356	ND
2015-05-14	9590-102-1556	ND
2015-05-14	9590-103-1504	ND
2015-05-14	9590-123-1437	ND
2016-01-07	9590-009-1048	ND
2016-01-07	9590-020-1009	ND
2016-01-20	9590-018-1244	ND
2016-02-04	9590-027-0946	ND
2016-02-09	9590-104-1214	ND
2016-02-10	9590-006-1204	ND
2016-02-22	9590-024-1519	ND
2016-03-01	9590-037-1248	ND
2016-03-03	9590-015-1426	ND
2016-04-05	9590-022-1344	ND
2016-04-27	9590-041-1039	ND
2016-05-03	9590-026-1258	ND
2016-05-04	9590-017-1424	ND
2016-06-28	9590-023-1352	ND
2016-08-02	9590-019-1102	ND
2016-09-14	9590-106-0909	ND
2016-09-20	9590-046-1102	ND
2016-10-05	9590-029-1003	ND
2016-10-05	9590-030-0904	ND
2016-12-07	9590-043-1444	ND
2016-12-29	9590-008-1413	ND
2016-12-29	9590-104-0951	ND
2017-01-19	9590-014-1048	ND
2017-03-02	9590-132-1100	ND
2017-04-05	9590-005-1428	ND
2017-11-21	9590-131-1240	ND
2017-12-14	9590-132-1456	ND
2018-02-01	9590-102-0955	ND
2018-02-01	9590-103-1043	ND
2018-02-06	9590-024-1030	ND
2018-03-19	9590-123-1200	ND
2018-03-20	9590-132-0953	ND
2018-05-01	9590-019-0943	ND
2018-05-01	9590-103-1010	ND
2018-05-02	9590-102-0858	ND
2018-05-03	9590-123-0928	ND
2018-07-18	9590-132-0914	ND
2018-09-04	9590-132-1034	ND
2018-09-11	9590-019-0930	ND
2018-10-02	9590-009-0928	ND
2018-10-09	9590-018-1140	ND
2018-10-29	9590-020-1318	ND
2018-11-06	9590-104-0936	ND
2018-11-07	9590-006-1026	ND
2018-11-08	9590-024-1201	ND
2018-11-20	9590-027-1346	ND
2018-12-06	9590-037-1016	ND
2018-12-06	9590-132-1148	ND
2018-12-18	9590-015-0944	ND
2019-01-03	9590-009-1359	ND
2019-01-03	9590-022-1009	ND
2019-01-23	9590-041-1311	ND
2019-01-29	9590-018-1411	ND
2019-02-05	9590-017-1431	ND
2019-02-05	9590-026-1409	ND
2019-02-06	9590-027-0924	ND
2019-02-20	9590-006-1031	ND
2019-02-20	9590-019-0921	ND
2019-02-20	9590-104-1139	ND
2019-03-06	9590-037-1024	ND
2019-03-06	9590-132-0954	ND
2019-03-14	9590-015-1443	ND
2019-03-21	9590-023-1310	ND
2019-04-01	9590-008-0915	ND
2019-04-01	9590-022-1120	ND
2019-04-02	9590-005-1406	ND
2019-05-01	9590-017-1232	ND
2019-05-01	9590-026-1411	ND
2019-05-08	9590-014-1433	ND
2019-05-08	9590-019-1004	ND
2019-05-16	9590-041-1228	ND
2019-06-12	9590-046-1030	ND
2019-06-18	9590-023-1321	ND
2019-06-18	9590-106-1107	ND
2019-06-18	9590-132-0948	ND
2019-07-02	9590-008-1020	ND
2019-07-10	9590-029-0937	ND
2019-07-18	9590-020-1120	ND
2019-07-18	9590-030-1340	ND
2019-08-01	9590-014-1129	ND
2019-08-13	9590-005-1110	ND
2019-09-12	9590-046-1045	ND
2019-09-12	9590-106-1057	ND
2019-09-12	9590-132-1442	ND
2019-09-17	9590-131-1340	ND
2019-09-25	9590-043-1242	ND
2019-10-01	9590-029-1125	ND
2019-10-03	9590-030-0940	ND
2019-10-08	9590-020-0949	ND
2019-10-30	9590-801-1110	ND
2019-10-30	9590-805-1339	ND
2019-12-03	9590-131-1013	ND
2019-12-03	9590-132-0946	ND
2019-12-05	9590-043-1357	ND