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EWG's Tap Water Database — 2021 UPDATE

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2,3,7,8-TCDD (Dioxin)

California Water Service (CWS) - Los Altos Suburban

Dioxins are contaminants released from chemical manufacturing, pulp and paper bleaching, and incineration of products that contain chlorine. 2,3,7,8-Tetrachlorodibenzodioxin (2,3,7,8-TCDD) is the most toxic chemical in the group of dioxins. Read More.

Dioxins are among the most toxic known environmental pollutants. As a class, dioxins are extremely toxic, persistent and bioaccumulative; these contaminants build up and are stored in fatty tissues and fluids, such as breast milk, and pass from the mother to the child. Most people are exposed to dioxins through the food they eat, primarily from meat, dairy, fish and eggs. In humans, dioxins are associated with cancer, birth defects, damage to the nervous and immune systems, altered metabolism, thyroid disruption, altered menstrual cycling and damage to the cardiovascular system.

 

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
2014ND330ND
2015ND70ND
2016N/A00N/A
2017ND310ND
2018ND60ND
2019N/A00N/A

ppt = parts per trillion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.0002 ppt

The EWG Health Guideline of 0.0002 ppt for 2,3,7,8-TCDD was defined by the Environmental Protection Agency as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.

EPA Maximum Contaminant
Level (MCL) 0.03 ppt

ppt = parts per trillion

All test results

Date Lab ID Result
2014-01-080013-008-1111ND
2014-01-150013-016-1051ND
2014-01-150013-002-1059ND
2014-02-100013-010-1140ND
2014-02-190013-018-1015ND
2014-02-270013-023-1059ND
2014-03-040013-015-1220ND
2014-03-040013-011-1130ND
2014-04-080013-020-1057ND
2014-04-090013-021-1328ND
2014-04-170013-022-1225ND
2014-05-140013-037-1343ND
2014-05-140013-023-1230ND
2014-06-040013-028-0920ND
2014-06-040013-024-1032ND
2014-06-040013-029-0830ND
2014-06-040013-002-1142ND
2014-06-040013-032-1142ND
2014-06-040013-035-1100ND
2014-07-020013-002-0935ND
2014-07-020013-016-1055ND
2014-07-090013-008-1009ND
2014-08-110013-010-1039ND
2014-08-110013-018-1025ND
2014-09-090013-015-1122ND
2014-09-090013-011-1303ND
2014-10-010013-022-1354ND
2014-10-020013-020-1233ND
2014-10-020013-021-1322ND
2014-12-100013-024-1251ND
2014-12-100013-028-1233ND
2014-12-100013-029-1136ND
2014-12-100013-032-1320ND
2015-02-020013-013-1522ND
2015-02-030013-013-1126ND
2015-03-032116-057-1002ND
2015-03-100013-030-1320ND
2015-06-239590-030-1030ND
2015-06-239590-013-1140ND
2015-06-239590-057-1100ND
2017-01-119590-011-0955ND
2017-01-119590-010-0930ND
2017-02-079590-023-1255ND
2017-02-089590-021-1300ND
2017-02-149590-020-1547ND
2017-03-159590-024-0915ND
2017-03-159590-028-1208ND
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
2017-06-132116-024-1142ND
2017-06-132116-028-1315ND
2017-07-069590-016-1145ND
2017-07-069590-002-1115ND
2017-07-199590-008-1030ND
2017-08-092155-037-1220ND
2017-08-092116-021-1150ND
2017-09-062116-035-1301ND
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
2017-12-129590-029-1045ND
2017-12-129590-032-1115ND
2017-12-202116-018-1345ND
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