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EWG's Tap Water Database — 2021 UPDATE

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

City of Davis

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.

 

34

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014N/A00N/A
2015ND160ND
2016ND20ND
2017ND40ND
2018ND110ND
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
2015-07-070013-004-1253ND
2015-07-070013-052-0648ND
2015-07-070013-030-0919ND
2015-07-070013-026-1041ND
2015-07-070013-025-0832ND
2015-07-070013-024-1120ND
2015-07-070013-023-0904ND
2015-07-070013-020-0757ND
2015-07-070013-010-1148ND
2015-07-070013-002-1333ND
2015-07-070013-006-1115ND
2015-07-070013-018-0721ND
2015-07-070013-015-1321ND
2015-07-070013-016-0957ND
2015-07-070013-017-1030ND
2015-07-210013-009-0747ND
2016-01-260013-019-1005ND
2016-02-010013-019-1002ND
2017-03-201228-057-1120ND
2017-06-141228-057-0820ND
2017-09-201228-057-0910ND
2017-12-121228-057-0735ND
2018-02-141228-057-0925ND
2018-04-181228-028-0855ND
2018-08-151228-028-0720ND
2018-08-151228-052-0930ND
2018-08-151228-057-0840ND
2018-08-151228-030-0640ND
2018-08-151228-025-0755ND
2018-08-151228-020-1001ND
2018-08-151228-019-0902ND
2018-08-151228-018-0819ND
2018-11-071228-028-0818ND
2019-02-061228-028-0820ND