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EWG's Tap Water Database — 2021 UPDATE

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Heptachlor

Harris County MUD 165

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

 

10

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
2015ND20ND
2016ND10ND
2017N/A00N/A
2018ND50ND
2019ND20ND

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
2015-05-27AC93470ND
2015-05-27AC93466ND
2016-03-21AD29762ND
2018-06-07AE29059ND
2018-06-07AE29060ND
2018-06-07AE29062ND
2018-08-24AE38575ND
2018-11-30AE47650ND
2019-01-31AE52525ND
2019-03-27AE60339ND