Chloromethane
Galveston County Water Control and Improvement District 19
Chloromethane is an industrial solvent, aerosol propellant and a refrigerant. It also forms as a byproduct of water disinfection. The EPA classifies chloromethane as possibly carcinogenic to humans.
5
Samples
0
Samples exceeding legal limit (MCL)
2
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | ND | 1 | 0 | ND |
| 2019 | ND | 1 | 0 | ND |
| 2020 | N/A | 0 | 0 | N/A |
| 2021 | ND | 1 | 0 | ND |
| 2022 | 7.80 ppb | 1 | 1 | 7.80 ppb |
| 2023 | 12.0 ppb | 1 | 1 | 12.0 ppb |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
EWG Health Guideline: 2.69 ppb
The EWG Health Guideline of 2.69 ppb for chloromethane was defined by the Environmental Protection Agency as a benchmark for testing under the Unregulated Contaminant Monitoring Rule program. This health guideline protects against cancer.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-05-18 | AE27036 | ND |
| 2019-06-12 | AE70399 | ND |
| 2021-07-01 | AF60388 | ND |
| 2022-05-13 | AF97077 | 7.80 ppb |
| 2023-09-11 | AG55579 | 12.0 ppb |