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EWG's Tap Water Database — 2021 UPDATE

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Heptachlor

Harris County Municipal Utility District 109

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
2014N/A00N/A
2015ND30ND
2016ND20ND
2017ND40ND
2018ND50ND
2019ND40ND

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
2015-07-06AC98467ND
2015-07-06AC98468ND
2015-12-02AD15257ND
2016-09-25AD51263ND
2016-12-05AD60485ND
2017-01-06AD63768ND
2017-04-21AD80809ND
2017-07-12AD89122ND
2017-10-24AE01943ND
2018-01-31AE11700ND
2018-01-31AE11683ND
2018-04-12AE22361ND
2018-07-26AE34736ND
2018-11-07AE45658ND
2019-02-14AE54691ND
2019-05-22AE67790ND
2019-08-14AE78741ND
2019-11-22AE90482ND