Contaminant Level (MCL)
Endothall is an herbicide, defoliant and desiccant (drying agent) that is most commonly used to treat aquatic weeds. It's used on potato, cotton, sugar beet, hops, turf and alfalfa crops, and arrives in drinking water primarily through agricultural runoff.
The EPA reports that acute exposure to endothall can cause “depressed breathing and heart rate.” The agency also warns that long term exposure can lead to problems with the digestive system:
Endothall has the potential to cause the following effects from a lifetime exposure at levels above the MCL [0.1 milligrams per Liter]: increase in size of some internal organs, particularly the stomach and intestine.
The EPA recommends granular activated carbon (GAC) for the treatment of endothall.
Sources: EPA (1), EPA (2), EPA (3), Image: WikiMedia, author: Pato Novoa
(whole house & well units)