2,4,5-TP (Silvex)
Chalk Hill Special Utility District
2(2,4,5-trichlorophenoxy) propionic acid (2,4,5-TP or Silvex) is a cancer-causing herbicide banned in the U.S. in 1985 because of its toxicity. It is still detected as a groundwater contaminant in areas where it was sprayed or stored.
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 | 1 | 0 | ND |
| 2019 | ND | 1 | 0 | ND |
| 2020 | ND | 3 | 0 | ND |
| 2021 | ND | 1 | 0 | ND |
| 2022 | ND | 1 | 0 | ND |
| 2023 | ND | 5 | 0 | ND |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
EWG Health Guideline: 3 ppb
The EWG Health Guideline of 3 ppb for 2,4,5-TP 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): 50 ppb
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-06-20 | Q1824487002 | ND |
| 2019-01-10 | Q1901411005 | ND |
| 2020-03-23 | Q2012183002 | ND |
| 2020-12-17 | Q2050083012 | ND |
| 2020-12-17 | Q2050083013 | ND |
| 2021-11-09 | Q2131359008 | ND |
| 2022-12-13 | Q2237298010 | ND |
| 2023-03-20 | Q2310465007 | ND |
| 2023-05-23 | Q2319409001 | ND |
| 2023-05-23 | Q2319409012 | ND |
| 2023-07-27 | Q2330274001 | ND |
| 2023-10-19 | Q2344966001 | ND |