Endothall
Endothall·Affects brain, kidneys
An aquatic herbicide applied directly to lakes, ponds, and irrigation canals to control submerged and floating weeds. Also used as a pre-harvest desiccant on cotton and potatoes.
Endothall
EPA limit
0.1 mg/L (MCL)
Most at risk
Residents near treated lakes and reservoirs, agricultural workers
Found in
City water · Well water
AquaOx filters
YesActivated coconut shell carbon
What it does to you
Health effects
Endothall's primary chronic concerns are damage to the kidneys and the gastrointestinal tract. Long-term animal studies show kidney lesions and changes in the lining of the stomach and intestines at moderate exposures, and the EPA set the drinking water standard based on these endpoints.
Acute exposure to concentrated product is highly irritating to the skin, eyes, and respiratory tract, and ingestion can cause severe gastrointestinal damage. The compound is also reported to affect the central nervous system at high exposures.
The EPA does not classify endothall as a carcinogen, but it is one of the more acutely toxic aquatic herbicides in current use, which is why it requires restricted-use certification for application.
Where it comes from
How it gets into your water
Endothall is applied directly to water to control submerged aquatic vegetation in lakes, ponds, reservoirs, and irrigation canals. It is also used as a pre-harvest desiccant on cotton, hops, and potatoes. Because the primary use is intentional application to water, the contamination pathway is direct.
The compound degrades within days to weeks in water, but during active treatment periods levels in treated bodies can briefly exceed drinking water standards. Public utilities drawing from treated reservoirs typically issue advisories before and during treatment.
Endothall binds moderately to sediment and does not migrate into groundwater readily, so private wells are at low risk unless the wellhead is very close to a treated surface water body.
Aquatic weed control
Direct application to lakes and ponds
Treated reservoirs
Brief elevation after application
Pre-harvest desiccation
Cotton and potato applications
Find out for yourself
Is it in your water?
Public utilities test for endothall and report results in their annual Consumer Confidence Report. Detections are uncommon outside of active treatment windows in surface-water-supplied systems.
If your community is on a reservoir that receives endothall treatment for aquatic weeds, watch for advisories around the treatment season. Private well owners are generally at low risk.
The fix
How AquaOx filters it
Endothall is filtered efficiently by activated carbon. The coconut shell carbon stage in The AquaOx adsorbs endothall molecules as water passes through, with independent testing showing high reduction rates.
For households on surface-water-supplied utilities or near treated water bodies, we recommend pairing The AquaOx with our FE Edition or RE Edition if iron or hydrogen sulfide is also present, and adding the under-sink RO for additional drinking-water polish.