2,4,5-TP (Silvex)
Guilford Water Authority
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 | 3 | 0 | ND |
| 2019 | ND | 1 | 0 | ND |
| 2020 | ND | 6 | 0 | ND |
| 2021 | N/A | 0 | 0 | N/A |
| 2022 | N/A | 0 | 0 | N/A |
| 2023 | ND | 10 | 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 |
|---|---|---|
| 2018-05-29 | 8055384-01 | ND |
| 2018-09-04 | 8091925-01 | ND |
| 2018-12-11 | 8122846-01 | ND |
| 2019-03-05 | 9032320-01 | ND |
| 2020-06-09 | 22559596.00 | ND |
| 2020-06-09 | 22559566.00 | ND |
| 2020-06-09 | 22559536.00 | ND |
| 2020-09-09 | 23136538.00 | ND |
| 2020-09-09 | 23136556.00 | ND |
| 2020-09-09 | 23136586.00 | ND |
| 2023-05-17 | 29053234.00 | ND |
| 2023-05-17 | 29053250.00 | ND |
| 2023-05-17 | 29053266.00 | ND |
| 2023-05-24 | 29053424.00 | ND |
| 2023-05-24 | 29053391.00 | ND |
| 2023-07-18 | 29651145.00 | ND |
| 2023-07-18 | 29651237.00 | ND |
| 2023-07-18 | 29651157.00 | ND |
| 2023-08-01 | 29651270.00 | ND |
| 2023-08-01 | 29651217.00 | ND |