Know Your Environment. Protect Your Health.

Heptachlor epoxide

Helms Water 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)

6

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.0120 ppb21ND - 0.0240 ppb
20190.0145 ppb21ND - 0.0290 ppb
20200.0130 ppb21ND - 0.0260 ppb
20210.0130 ppb21ND - 0.0260 ppb
20220.0160 ppb21ND - 0.0320 ppb
20230.0250 ppb21ND - 0.0500 ppb

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

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 Lab ID Result
2018-04-30CB02844-010.0240 ppb
2018-04-30CB02844-02ND
2019-06-06CC03216-010.0290 ppb
2019-06-06CC03216-02ND
2020-04-15CD03897-010.0260 ppb
2020-04-15CD03897-02ND
2021-05-05CE02456-010.0260 ppb
2021-05-05CE02456-02ND
2022-06-09CF02963-010.0320 ppb
2022-06-09CF02963-02ND
2023-05-11752-6930-10.0500 ppb
2023-05-11752-6930-2ND