2,4,5-TP (Silvex)
Pendleton Water Association
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 | 4 | 0 | ND |
| 2019 | ND | 4 | 0 | ND |
| 2020 | ND | 2 | 0 | ND |
| 2021 | ND | 2 | 0 | ND |
| 2022 | ND | 2 | 0 | ND |
| 2023 | ND | 2 | 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 |
|---|---|---|
| 2018-02-20 | 35375979001 | ND |
| 2018-02-20 | 35375979001 | ND |
| 2018-08-06 | 35409599001 | ND |
| 2018-08-06 | 35409599001 | ND |
| 2019-03-12 | 35454721001 | ND |
| 2019-03-12 | 35454721001 | ND |
| 2019-08-07 | 35488972001 | ND |
| 2019-08-07 | 35488972001 | ND |
| 2020-02-10 | 35529911001 | ND |
| 2020-09-22 | 35579669001 | ND |
| 2021-01-20 | 35606276002 | ND |
| 2021-08-18 | 35657244005 | ND |
| 2022-02-21 | 35699244001 | ND |
| 2022-08-29 | 35743858002 | ND |
| 2023-02-27 | 35782747002 | ND |
| 2023-08-07 | 35819671001 | ND |