Menu

EWG's Tap Water Database — 2021 UPDATE

Donate

2,4-D

California Water Service (CWS) - Los Altos Suburban

2,4-D (2,4-dichlorophenoxyacetic acid) is a herbicide that can be applied directly to GMO corn and soy plants engineered to withstand this toxic chemical. Americans' exposures to 2,4-D from food and drinking water will likely increase in years to come as farmers plant more of these GMO crops. Read More.

2,4-D is an endocrine disruptor that interferes with thyroid hormones. The International Agency for Research on Cancer classifies 2,4-D as possibly carcinogenic to humans. In occupational studies, farmers exposed to 2,4-D tended to have higher incidences of damaged and malformed sperm. Laboratory animals exposed to 2,4-D during gestation are born underdeveloped and are more likely to have birth defects.

 

77

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
2014ND340ND
2015ND60ND
2016N/A00N/A
2017ND310ND
2018ND60ND
2019N/A00N/A

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 20 ppb

The EWG Health Guideline of 20 ppb for 2,4-D was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against harm to internal organs.

EPA Maximum Contaminant
Level (MCL) 70 ppb

The legal limit for 2,4-D, established in 1991, was based on toxicity studies in laboratory animals conducted in the 1980s. This limit may not fully protect against harm to the nervous system, harm to the thyroid, and hormone disruption.

ppb = parts per billion

All test results

Date Lab ID Result
2014-01-085810-008-1130ND
2014-01-155810-002-1204ND
2014-01-155810-016-1140ND
2014-02-105810-010-1151ND
2014-02-195810-018-1000ND
2014-02-275810-023-1106ND
2014-03-045810-015-1228ND
2014-03-055810-011-1133ND
2014-04-085810-020-1119ND
2014-04-095810-021-1343ND
2014-04-175810-022-1230ND
2014-05-145810-037-1403ND
2014-05-215810-023-1215ND
2014-06-045810-029-0855ND
2014-06-045810-024-1033ND
2014-06-045810-028-0923ND
2014-06-045810-032-1143ND
2014-06-045810-035-1100ND
2014-07-025810-002-1000ND
2014-07-025810-016-1052ND
2014-07-095810-008-1015ND
2014-08-115810-018-1010ND
2014-08-115810-010-1048ND
2014-09-095810-015-1130ND
2014-09-095810-011-1312ND
2014-10-015810-022-1357ND
2014-10-025810-021-1312ND
2014-10-025810-020-1228ND
2014-11-055810-037-1335ND
2014-12-105810-024-1301ND
2014-12-105810-032-1314ND
2014-12-105810-029-1133ND
2014-12-105810-035-1134ND
2014-12-105810-028-1227ND
2015-02-035810-013-1129ND
2015-03-039590-057-1010ND
2015-03-105810-030-1323ND
2015-06-239590-030-1030ND
2015-06-239590-057-1100ND
2015-06-239590-013-1140ND
2017-01-119590-010-0930ND
2017-01-119590-011-0955ND
2017-02-079590-023-1255ND
2017-02-089590-021-1300ND
2017-02-149590-020-1547ND
2017-03-159590-028-1208ND
2017-03-159590-024-0915ND
2017-04-049590-010-1400ND
2017-04-059590-016-1200ND
2017-04-069590-011-1110ND
2017-05-049590-020-1245ND
2017-05-049590-023-1200ND
2017-05-099590-021-1130ND
2017-06-139590-028-1315ND
2017-06-139590-024-1142ND
2017-07-069590-016-1145ND
2017-07-069590-002-1115ND
2017-07-199590-008-1030ND
2017-08-099590-037-1220ND
2017-08-099590-022-1150ND
2017-09-069590-035-1301ND
2017-09-069590-032-1230ND
2017-09-069590-029-1500ND
2017-10-119590-002-1030ND
2017-10-119590-008-1345ND
2017-11-139590-037-1300ND
2017-11-149590-022-1300ND
2017-12-069590-035-1200ND
2017-12-129590-032-1115ND
2017-12-129590-029-1045ND
2017-12-209590-018-1345ND
2018-02-069590-013-1015ND
2018-03-079590-030-1145ND
2018-04-259590-013-1030ND
2018-06-069590-030-0930ND
2018-09-189590-057-1234ND
2018-12-059590-057-1100ND