Quantification and characterization of glyphosate use and loss in a residential area.
Urban runoff can be a significant source of pesticides in urban streams. However, quantification of this source has been difficult because pesticide use by urban residents (e.g., on pavements or in gardens) is often unknown, particularly at the scale of a residential catchment. Proper quantification and characterization of pesticide loss via urban runoff require sound information on the use and occurrence of pesticides at hydrologically-relevant spatial scales, involving various hydrological conditions. We conducted a monitoring study in a residential area (9.5 ha, Flanders, Belgium) to investigate the use and loss of a widely-used herbicide (glyphosate) and its major degradation product (aminomethylphosphonic acid, AMPA). The study covered 13 rainfall events over 67 days. Overall, less than 0.5% of glyphosate applied was recovered from the storm drain outflow in the catchment. Maximum detected concentrations were 6.1 μg/L and 5.8 μg/L for glyphosate and AMPA, respectively, both of which are below the predicted no-effect concentration for surface water proposed by the Flemish environmental agency (10 μg/L), but are above the EU drinking water standard (0.1 μg/L). The measured concentrations and percentage loss rates can be attributed partially to the strong sorption capacity of glyphosate and low runoff potential in the study area. However, glyphosate loss varied considerably among rainfall events and event load of glyphosate mass was mainly controlled by rainfall amount, according to further statistical analyses. To obtain urban pesticide management insights, robust tools are required to investigate the loss and occurrence of pesticides influenced by various factors, particularly the hydrological and spatial factors.
VITO, Flemish Institute for Technological Research, Environmental Modelling Unit, Boeretang 200, 2400 Mol, Belgium; VUB, Free University of Brussels, Department of Hydrology and Hydraulic Engineering, Pleinlaan 2, 1050 Brussels, Belgium. Electronic address: ting.tang@vito.be.
Ting
T
Tang
VITO, Flemish Institute for Technological Research, Environmental Modelling Unit, Boeretang 200, 2400 Mol, Belgium.
Wesley
W
Boënne
VITO, Flemish Institute for Technological Research, Environmental Modelling Unit, Boeretang 200, 2400 Mol, Belgium.
Nele
N
Desmet
VITO, Flemish Institute for Technological Research, Environmental Modelling Unit, Boeretang 200, 2400 Mol, Belgium; Ghent University, Department of Soil Management, Coupure Links 653, 9000 Ghent, Belgium; University of Antwerp, Department of Bioscience Engineering, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
Piet
P
Seuntjens
VITO, Flemish Institute for Technological Research, Environmental Modelling Unit, Boeretang 200, 2400 Mol, Belgium.
Jan
J
Bronders
VUB, Free University of Brussels, Department of Hydrology and Hydraulic Engineering, Pleinlaan 2, 1050 Brussels, Belgium; UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, Netherlands.
Ann
A
van Griensven
D001530:Belgium; D004784:Environmental Monitoring; D005998:Glycine / Q000031:analogs & derivatives* / Q000032:analysis; D006540:Herbicides / Q000032:analysis*; D011891:Rain / Q000737:chemistry; D045483:Rivers / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D000097797:Glyphosate
D005998:Glycine; D006540:Herbicides; D014874:Water Pollutants, Chemical; D000097797:Glyphosate
Glyphosate; Hard surfaces; Loss rates; Residential runoff; Storm drain