EPA Maximum Contaminant Level (MCL) |
0.5 mg/L |
Picloram is a synthetic organic chemical used as an herbicide to control woody plants and broad-leafed weeds. It arrives in drinking water primarily through herbicidal runoff.
Acute exposure is generally not a health concern; according to the Extension Toxicology Network, picloram is “slightly to practically nontoxic via ingestion.” Long term exposure to large amounts, however, can affect the liver. According to the EPA:
Some people who drink water containing picloram well in excess of the maximum contaminant level [0.5 milligrams per Liter] for many years could experience liver problems.
The EPA recommends granular activated carbon (GAC) for the treatment of picloram.
Sources: EPA, Extension Toxicology Network, Photo: geograph.org.uk, author: Walter Baxter
(whole house & well units)