Chloromethane
Williams Water Supply
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.
17
Samples
0
Samples exceeding legal limit (MCL)
14
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | 2.48 ppb | 4 | 4 | 1.50 ppb - 3.30 ppb |
| 2019 | 5.30 ppb | 3 | 3 | 3.20 ppb - 8.30 ppb |
| 2020 | 5.90 ppb | 2 | 2 | 5.30 ppb - 6.50 ppb |
| 2021 | 5.58 ppb | 4 | 4 | 2.80 ppb - 8.80 ppb |
| 2022 | 4.50 ppb | 4 | 4 | 1.70 ppb - 7.80 ppb |
| 2023 | N/A | 0 | 0 | N/A |
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 |
|---|---|---|
| 2018-02-06 | OE622249 | 1.90 ppb |
| 2018-05-01 | OE652868 | 3.20 ppb |
| 2018-08-07 | OE695222 | 1.50 ppb |
| 2018-11-07 | OE738065 | 3.30 ppb |
| 2019-05-06 | OE803980 | 4.40 ppb |
| 2019-08-05 | OE845462 | 3.20 ppb |
| 2019-11-11 | OE892259 | 8.30 ppb |
| 2020-08-03 | OE1156353 | 6.50 ppb |
| 2020-11-03 | OE1396829 | 5.30 ppb |
| 2021-02-01 | OE1573212 | 4.80 ppb |
| 2021-05-03 | OE1683169 | 5.90 ppb |
| 2021-08-02 | OE1778892 | 8.80 ppb |
| 2021-11-01 | OE1915530 | 2.80 ppb |
| 2022-02-01 | OE2035034 | 1.70 ppb |
| 2022-06-15 | OE2118487 | 7.80 ppb |
| 2022-08-09 | OE2153453 | 5.50 ppb |
| 2022-11-01 | OE2200810 | 3.00 ppb |