trans-1,2-Dichloroethylene
Northwest Harris County Municipal Utility District 23
1,2-Dichloroethylene, a neurotoxic solvent, exists in two different forms: trans-1,2-dichloroethylene and cis-1,2-dichloroethylene. A mixture of the two forms is used to manufacture other solvents and chemical products.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | ND | 4 | 0 | ND |
| 2019 | ND | 3 | 0 | ND |
| 2020 | ND | 3 | 0 | ND |
| 2021 | ND | 4 | 0 | ND |
| 2022 | ND | 4 | 0 | ND |
| 2023 | ND | 4 | 0 | ND |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
EWG Health Guideline: 60 ppb
The EWG Health Guideline of 60 ppb for trans-1,2-dichloroethylene 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 harm to internal organs.
EPA Maximum Contaminant
Level (MCL): 100 ppb
The legal limit for trans-1,2-dichloroethylene, established in 1991, was based on a toxicity study in laboratory animals conducted in the 1980s.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-01-11 | AE08956 | ND |
| 2018-05-17 | AE26815 | ND |
| 2018-07-12 | AE33153 | ND |
| 2018-10-09 | AE42952 | ND |
| 2019-01-31 | AE52467 | ND |
| 2019-09-25 | AE84642 | ND |
| 2019-11-07 | AE88933 | ND |
| 2020-02-13 | AE98459 | ND |
| 2020-08-13 | AF23542 | ND |
| 2020-12-03 | AF36488 | ND |
| 2021-03-09 | AF46016 | ND |
| 2021-04-06 | AF49185 | ND |
| 2021-08-12 | AF66123 | ND |
| 2021-10-21 | AF74371 | ND |
| 2022-02-03 | AF83333 | ND |
| 2022-05-17 | AF97252 | ND |
| 2022-07-21 | AG05793 | ND |
| 2022-10-25 | AG18331 | ND |
| 2023-01-12 | AG24446 | ND |
| 2023-04-13 | AG36773 | ND |
| 2023-08-17 | AG53066 | ND |
| 2023-10-12 | AG59738 | ND |