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EWG's Tap Water Database — 2021 UPDATE

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Heptachlor epoxide

Tbw/s. Pasco Wellfield Chemical Feed System

Heptachlor epoxide is a breakdown product of heptachlor, a highly toxic and carcinogenic pesticide banned in the U.S. since the 1980s.

 

12

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND20ND
2015ND20ND
2016ND20ND
2017ND20ND
2018ND20ND
2019ND20ND

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.006 ppb

The EWG Health Guideline of 0.006 ppb for heptachlor epoxide 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 cancer.

EPA Maximum Contaminant
Level (MCL) 0.2 ppb

The legal limit for heptachlor epoxide, established in 1991, was based on analytical detection limits at the time that the standard was set. This limit may not fully protect against the risk of cancer.

ppb = parts per billion

All test results

Date Result
2014-04-09ND
2014-06-03ND
2015-04-01ND
2015-04-07ND
2016-04-06ND
2016-05-10ND
2017-04-05ND
2017-04-18ND
2018-04-04ND
2018-04-09ND
2019-04-02ND
2019-04-03ND