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EWG's Tap Water Database — 2021 UPDATE

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Heptachlor

Marco Rural Water Company

Heptachlor is an insecticide used for termite control until 1988. It is linked to cancer, hormone disruption and neurotoxicity.

 

18

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
2014ND20ND
2015N/A00N/A
2016ND80ND
2017N/A00N/A
2018N/A00N/A
2019ND80ND

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.008 ppb

The EWG Health Guideline of 0.008 ppb for heptachlor 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) 0.4 ppb

The legal limit for heptachlor, 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 due to heptachlor exposure.

ppb = parts per billion

All test results

Date Lab ID Result
2014-03-04AD36307ND
2014-06-10AD41057ND
2016-11-08AD85403ND
2016-11-08AD85422ND
2016-11-08AD85395ND
2016-11-08AD85412ND
2016-11-08AD85401ND
2016-11-08AD85416ND
2016-11-08AD85399ND
2016-11-08AD85414ND
2019-12-02AE40915ND
2019-12-02AE40929ND
2019-12-03AE41078ND
2019-12-03AE41076ND
2019-12-03AE41048ND
2019-12-03AE41070ND
2019-12-03AE41072ND
2019-12-03AE41074ND