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EWG's Tap Water Database — 2021 UPDATE

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

Three Valleys Municipal Water District

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.

 

17

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND30ND
2015ND20ND
2016ND50ND
2017ND40ND
2018ND20ND
2019ND10ND

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
2014-02-189588-002-0800ND
2014-06-109588-004-1030ND
2014-09-169588-004-1101ND
2015-03-109588-002-0930ND
2015-06-099588-004-0940ND
2016-03-159588-002-0900ND
2016-06-219588-004-1006ND
2016-06-219588-002-1030ND
2016-09-139588-002-1000ND
2016-12-139588-002-1655ND
2017-03-219588-004-1040ND
2017-06-219588-004-1100ND
2017-06-229588-002-1000ND
2017-09-129588-002-0900ND
2018-06-129588-004-0000ND
2018-09-119588-002-1045ND
2019-09-179588-002-1005ND