The occurrence of glyphosate in surface water

The commonly used non-selective herbicide glyphosate (N-[Phosphonomethyl]gl ycin) occurred in surface water of two small tributaries of the river Ruhr in North-Rhine-Westphalia (FRG) with a maximum concentration of 590 ng/l. I n the examined catchment areas weed control application in rail tracks is o ne of the main sources of an input to surface water. The occurrence of the metabolite aminomethyl phosphonic acid (AMPA) was linked to glyphosate load rather than to a detergent inflow via municipal sewage. The observed disap pearance of glyphosate was faster than the disappearance of diuron indicati ng a lower persistence. A final assessment of the importance of highly pola r pesticides in organic contaminant of surface water needs extended water m onitoring analyses and further field investigation.