Heptachlor
City of Friendswood
Heptachlor is an insecticide used for termite control until 1988. It is linked to cancer, hormone disruption and neurotoxicity.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | ND | 3 | 0 | ND |
| 2015 | ND | 4 | 0 | ND |
| 2016 | ND | 1 | 0 | ND |
| 2017 | ND | 1 | 0 | ND |
| 2018 | ND | 4 | 0 | ND |
| 2019 | ND | 1 | 0 | ND |
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 |
|---|---|---|
| 2014-02-20 | AC43948 | ND |
| 2014-02-20 | AC43949 | ND |
| 2014-03-20 | AC47856 | ND |
| 2015-02-05 | AC79543 | ND |
| 2015-05-19 | AC92691 | ND |
| 2015-05-19 | AC92692 | ND |
| 2015-05-19 | AC92693 | ND |
| 2016-02-04 | AD22263 | ND |
| 2017-01-19 | AD65886 | ND |
| 2018-01-29 | AE11109 | ND |
| 2018-05-21 | AE27093 | ND |
| 2018-05-21 | AE27094 | ND |
| 2018-09-17 | AE40331 | ND |
| 2019-02-04 | AE52755 | ND |