HS2.3.6

EDI
Micropollutants and pathogens in the soil-groundwater-river continuum: modelling, monitoring and mitigation

A large number of pathogens, micropollutants and their transformation products (veterinary and human pharmaceuticals, personal care products, pesticides and biocides, chlorinated compounds, PFAS, heavy metals) pose a risk for soil, groundwater and surface water. The large diversity of compounds and of their sources makes the quantification of their occurrence in the terrestrial and aquatic environment across space and time a challenging task. Regulatory monitoring programmes cover a small selection out of the compound diversity and quantify these selected compounds only at coarse temporal and spatial resolution. Carefully designed monitoring however allows to detect and elucidate processes and to estimate parameters in the aquatic environment. Modelling is a complementary tool to generalize measured data and extrapolate in time and space, which is needed as a basis for scenario analysis and decision making. Mitigation measures can help reduce contamination of ground- and surface water and impacts on water quality and aquatic ecosystems.

This session invites contributions that improve our quantitative understanding of the sources and pathways, mass fluxes, the fate and transport and the mitigation of micropollutants and pathogens in the soil-groundwater-river continuum.

Topics cover:
- Novel sampling and monitoring concepts and devices
- New analytical methods, new detection methods for DNA, pathogens, micropollutants, non-target screening
- Experimental studies and modelling approaches to quantify diffuse and point source inputs
- Novel monitoring approaches such as non-target screening as tools for improving processes understanding and source identification such as industries
- Comparative fate studies on parent compounds and transformation products
- Diffuse sources and (re-)emerging chemicals
- Biogeochemical interactions and impact on micropollutant behaviour
- Setup of mitigation measures and evaluating their effectiveness.

Convener: Matthias Gassmann | Co-conveners: Daniele la Cecilia, Claudia Ferrario, Stefan Reichenberger, Sylvain Payraudeau
Presentations
| Wed, 25 May, 08:30–11:45 (CEST)
 
Room 2.15

Presentations: Wed, 25 May | Room 2.15

Chairpersons: Sylvain Payraudeau, Matthias Gassmann
08:30–08:35
Organic micropollutants
08:35–08:42
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EGU22-122
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ECS
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Highlight
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On-site presentation
Shulamit Nussboim, Orah Felicia Moshe, Jonathan B. Larrone, Lea Wittenberg, and Elazar Volk

Non-point pollutants, such as fertilizers and pesticides, are transported in water and travel via complex hydrologic flowpaths, with each field being a diffuse source of agrochemicals. Although pollutant transport in tile drains has been investigated widely, most studies occurred in temperate zones, with insufficient focus on leaching timing. We investigate the leachate timing and specific pathways from the field to the stream, to better understand the unique transport dynamics in Eastern Mediterranean climates, in areas with extensive subsurface drainage systems. To improve basin management strategies, this study targets the knowledge gap regarding specific pollutant transport and timing, which results in inefficient policies to reduce water pollution.  In our investigation of two crop fields in the Kishon basin, Israel, the systems drain both soil water and high groundwater, providing an opportunity to examine water quality dynamics in multiple pathways. We collected water samples from field runoff, subsurface pipes, and groundwater during summer irrigation and winter storm events. Results show a clear spatial distribution of agrochemicals due to their properties. Higher number of pesticides were found in ponded field water and their concentrations were higher in order of magnitude in compare to tile drainage pipes. We identified pesticides in all samples that had not been applied to the field within the last 1.5 years.  Leaching timing was demonstrated with higher pesticide concentration appearing in water collected from drainage pipes during irrigation and pesticides concentration decreasing after irrigation ended. The concentration changes were observed within 12-15 hours after opening or closing irrigation. Tracking the pools, the high concentration in the top soil creates a pesticides reservoir transported with the onset of irrigation and rain.  The leaching timing was demonstrated as well by lab results and measuring in-situ EC and pH.  After a four-day storm, EC declined drastically, demonstrating the input of relatively low nutrient content water to the high concentrations present in the high water table. Later in the winter, surface runoff in the main draining trench from the field to the stream contained high concentrations of phosphate and sediments and low concentrations of nitrate and chloride, compared to surface runoff in the field. Since nitrate and chloride are highly soluble, the reduced concentration in the draining trench to the stream demonstrates that water percolates downwards through the soil column with solutes rather than propagating with surface runoff, and particulate-bound species and sediments travel via surface runoff to the stream. Demonstrating pollutant transport pathways and timing, we provide a window into the propagation mechanisms of pollutants at a small scale, to support decision making and improve basin management.

 

How to cite: Nussboim, S., Moshe, O. F., Larrone, J. B., Wittenberg, L., and Volk, E.: Agrochemical transport in the field scale: the case study of a subsurface drainage system in the Kishon Basin, Israel, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-122, https://doi.org/10.5194/egusphere-egu22-122, 2022.

08:42–08:49
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EGU22-12528
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ECS
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Presentation form not yet defined
Marta Llamas, Joaquín Jiménez-Martínez, Iñaki Vadillo, Pablo Jiménez-Gavilán, Pablo Lara-Martín, and Carmen Corada-Fernández

Contaminants of Emerging Concern (CECs) and regulated organic pollutants pose a serious threat to water quality and their spatial distribution is challenging to assess as it can be driven by several factors.

In the current work, we focus on the distribution of a wide range of regulated and non-regulated organic contaminants in groundwater of the Fuente de Piedra lagoon catchment, in Southern Spain. Groundwater samples were collected and they were analyzed for (I) 185 organic contaminants and (II) water ions and stable isotopes (δ2H, δ18O and δ13C). Target organic contaminants included pharmaceuticals, personal care products, polyaromatic hydrocarbons, pesticides, flame retardants and plastizicers.

The Fuente de Piedra lagoon is a hypersaline wetland located in an endorheic basin (150 km2) in which three main aquifer types, with an hydraulic connection, can be distinguished: (I) unconfined carbonate aquifers with low mineralized water corresponding to two mountain ranges; (II) an unconfined porous aquifer formed by Quaternary and Miocene deposits, more exposed to pollution from anthropogenic activities; and (III) a karstic-type confined aquifer developed in a massive accumulation of evaporites and gypsum (Upper Triassic). 

In total, 32 organic contaminants were detected, at least once. An attempt to evaluate the importance of the different factors affecting the spatial distribution of the organic contaminants have been conducted. Attention has been paid to the main physico-chemical properties of the pollutants (hydrophobicity and speciation), distribution of pollution sources and anthropogenic pressures in the area (including water management practices) and hydrogeological characteristics of the different aquifers. A geochemical model has been built to characterize water mixing processes in order to better understand transport and fate of these organic contaminants.

How to cite: Llamas, M., Jiménez-Martínez, J., Vadillo, I., Jiménez-Gavilán, P., Lara-Martín, P., and Corada-Fernández, C.: Occurrence, distribution and behaviour of contaminants of emerging concern and regulated organic pollutants. Case study: the endorheic catchment of Fuente de Piedra Lagoon (Southern Spain). , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12528, https://doi.org/10.5194/egusphere-egu22-12528, 2022.

08:49–08:56
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EGU22-5666
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ECS
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On-site presentation
Elise Verstraeten, Alice Alonso, Marnik Vanclooster, and Louise Collier

Over the last decades, various regulations and good management practices have been implemented to reverse the increasing concentration of nitrates and pesticides in our groundwaters. The effects of these efforts on groundwater quality are complex to assess because of the non-linearity and the spatial heterogeneity of the hydrological fluxes, the numerous potential pollution sources, and the temporal delays due to the infiltration time in the vadose zone.

We use the information encoded in the monitoring data of 52 groundwater wells and galleries in Wallonia (Belgium) to assess the effectiveness of the regulations and management practices. We analyze the trends of the time series and subsequently seek to explain their spatial and temporal variability by looking into the characteristics likely to support or undermine the regulations and good practices such as water depth or urban development.

Our results should contribute to a better understanding and prediction of the groundwater quality trends at the catchment scale in Wallonia, providing guidance to catchment management. 

How to cite: Verstraeten, E., Alonso, A., Vanclooster, M., and Collier, L.: Characterising trend changes of groundwater quality in Wallonia (Belgium), EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5666, https://doi.org/10.5194/egusphere-egu22-5666, 2022.

08:56–09:03
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EGU22-454
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ECS
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On-site presentation
Mohammad Arar and Anat Bernstein
Atrazine is one of the most frequently detected pesticides in groundwater. Its microbial degradation is often studied in soils, but less frequently studied in groundwater . In Israel, atrazine is the most frequently detected pesticide in groundwater. It was hypothesized that its degradation potential in groundwater is wide. Thus, this study aimed to gain indication for ongoing degradation in atrazine affected groundwater.

 Results of microcosm experiments with groundwater bacteria indicated on its degradation potential. PCR analysis of microcosms cultures has shown the presence of atzA and trzN genes. Furthermore, LC-MS analysis of groundwater extracts identified a large proportion of atrazine degradation products indicating on ongoing degradation in the field. Further isotope analysis of atrazine in  groundwater extracts will provide an additional line of evidence for ongoing degradation in groundwater.

How to cite: Arar, M. and Bernstein, A.: Microbial degradation of Atrazine in Groundwater, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-454, https://doi.org/10.5194/egusphere-egu22-454, 2022.

09:03–09:10
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EGU22-7082
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On-site presentation
Sylvie Kříženecká

The strength of the interaction between a pesticide and the soil organic matter is a key parameter to assess the risk of it reaching to groundwater with potentially harmful effects to human health. The humic substances (HS) play important role in the adsorption of pesticides. The mechanism of these reactions includes cation exchange, chelation, coordination, hydrogen bonding, charge transfer, hydrofobic bonding, π bonding, and van der Waals bonding. Many factors could affect the pesticide signals in LC-MS/MS analysis.  The chemical and physical properties of the analytes and the composition of the sample matrix are amongst them. Acidification of the solution can also affect the ionization of analytes (pesticides) in the ion source.

In this work, a approach that allows measuring such pesticide interactions  in acidic solutions (formic acid - FA, acetic acid - AA). These were representatives of pesticides phenoxycarboxylic, chloroacetanilide, urea, organophosphate, triazine, triazole and representatives of other pesticides. The measurements showed that different groups of pesticides exhibit different behaviors in the presence of humic acids. There were differences both between different groups of pesticides and between individual representatives within certain groups.

The resulting measured concentration values differed most from each other for organophosphate pesticides. At the same time, the structures of the molecules of these pesticides vary greatly. Dimethoat had a more pronounced signal drop than diazinon at lower pesticide concentrations (25 ng/l). The effect of the addition of FA and AA on the resulting concentration values also differed between the two pollutants studied. In diazinon, the addition of AA signal decreased in dimethoat, on the contrary, increased. The addition of FA in diazinon further dampened the signal, while dimethoat experienced a similar increase in analyte values as with the addition of AA. From the results of the measurements, it can be deduced that representatives of organophosphate pesticides show different behavior in the presence of HA.

How to cite: Kříženecká, S.: Influence of sample acidification in the presence of humic substances in determination of pesticide by LC-MS/MS, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7082, https://doi.org/10.5194/egusphere-egu22-7082, 2022.

09:10–09:17
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EGU22-5104
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ECS
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On-site presentation
Tobias Junginger, Sylvain Payraudeau, and Gwenaël Imfeld

Urban biocides like terbutryn are used in construction materials such as render and paints on façades to prevent the growth of algae and fungi. With wind-driven rain, those contaminants leach into the environment and pose a risk for groundwater contamination. In our study, we combined leaching experiments with artificial facades to quantify biocide release, lysimeter experiments to get insights into the reactive transport under environmental conditions, and field sampling in an urban catchment to follow-up biocide release from source (building facades) to sinks (stormwater retention systems/ groundwater). We use concentrations of terbutryn as well as its four major transformation products to establish mass balances. Furthermore, we use Compound-Specific Isotope Analysis (CSIA) as a concentration-independent tool to identify the dominant degradation processes in the environment by taking into account (i) isotopic enrichment of stable isotopes by dual-isotope plots and (ii) patterns of formed transformation products. Façade leaching experiments show that high quantities of terbutryn remain on the facades and leaching continues for a long period. Transformation products are already formed on the facades through photodegradation. Reactive transport on typical urban surfaces (gravel, paved stones with joints, soil) indicates high retention of terbutryn in the grass lysimeter and faster leaching in gravel and pavement lysimeters with low recoveries of terbutryn in the first 2 months (3 %, 1 % and <1 % in gravel, paved and grass lysimeter, respectively). In all lysimeters, transformation products were formed, exceeding the concentrations of leached terbutryn at some sampling points, indicating higher mobility through better solubility in water of the daughter compounds. The overall extend of (bio-)degradation in the lysimeters was low for terbutryn, as supported by CSIA data (changes in Δδ13C < 2‰). Grab samples in a stormwater retention pond and swale system in an urban catchment confirmed the leaching of terbutryn and transformation products in a catchment from 6-year-old buildings with concentrations of terbutryn between 3 and 70 ng/L, as well as TP terbutryn sulfoxide, exceeding 400 ng/L. Our study implies the importance of detailed monitoring of urban biocides to understand the reactive transport processes on their pathways into groundwater and underlines the importance of monitoring also transformation products in typical monitoring schemes.

How to cite: Junginger, T., Payraudeau, S., and Imfeld, G.: The Urban Biocide Terbutryn: Field investigations to explore release and reactive transport under environmental conditions, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5104, https://doi.org/10.5194/egusphere-egu22-5104, 2022.

09:17–09:24
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EGU22-4334
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ECS
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Highlight
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On-site presentation
Felicia Linke, Lena Schnarr, Oliver Olsson, Klaus Kümmerer, Frank Preusser, Hannes Leistert, Marcus Bork, and Jens Lange

Urban swales collect stormwater runoff containing micropollutants such as biocides washed off from facades during wind driven rain. Although swales retain contaminants, they might eventually reach groundwater through soil. However, there is little data available of biocide occurrence in urban swale sediment. In this study, we measured the biocide entry to an urban swale and its distribution in sediment. The selected swale in south-west Germany collects runoff from a 3 ha residential area with 46 houses. Two pipes lead into the swale, one collecting runoff from a 1 ha area (“East”) and one from a 2 ha area (“West”). We took sediment samples after dry and wet periods close to both pipes and additional water grab samples during wet periods. In total, we collected 19 stormwater samples during 7 events and 116 sediment samples during 8 days over a period of two years. Water samples were analyzed for three biocides (diuron, terbutryn, octylisothiazoline= OIT) and four transformation products (= TPs, diuron-desmethyl, terbuthylazine-2-hydroxy, terbutryn-desethyl, terbumeton) using LC-MS/MS. Sediment samples were analyzed for terbutryn, OIT and 3 TPs of terbutryn. Finally, we linked a water balance model to a leaching model and simulated longterm biocide input into the swale. This we compared with biocide concentration in the swale sediments using a mass balance approach. We found all biocides and all TPs in water samples at both pipes confirming biocide input to the swale. In the sediment, terbutryn concentrations were generally below 1 ng/g. Of three measured TPs of terbutryn we detected only one, terbutryn-desethyl (<1 ng/g dry weight). There were no significant differences of terbutryn concentration in the sediment before and after storm events. This suggests continuous input and long presence of biocides. Concentrations at pipe West were higher than at pipe East. This pointed to differences in the connected areas such as differences in paints used at individual houses. At the outlet of pipe West, we found maximum concentrations of terbutryn (26 ng/g) in saturated sediments below standing water, which suggests more sorption and less degradation at this location. We thus assume that dry condition in swales during dry weather promote degradation. Overall, our findings emphasize that not only the quantity of urban runoff should guide the design of urban swale systems but also potential biocide entry.

How to cite: Linke, F., Schnarr, L., Olsson, O., Kümmerer, K., Preusser, F., Leistert, H., Bork, M., and Lange, J.: Measuring and modeling biocide entry from facades in urban swale sediment , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4334, https://doi.org/10.5194/egusphere-egu22-4334, 2022.

09:24–09:31
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EGU22-3887
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ECS
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Virtual presentation
Mike Fuchs, Sebastian Gebler, and Andreas Lorke

Modelling environmental concentrations of pesticides at landscape-level is of growing interest for pesticide registration and product stewardship, including higher-tier studies in risk assessment, mitigation measures, monitoring support and decision making. Typically, runoff, drainage, and leaching are taken into account, using different modelling concepts. However, the modelling of spray drift often is simplified or neglected in landscape-level models. For example, the Soil and Water Assessment Tool (SWAT) does not consider spray drift for pesticide transport simulation. Hence, external offline calculations of spray drift are necessary, with the pesticide masses added to the channel network via point sources. Although this is a pragmatic solution for including spray drift, future scientific questions in high spatial and temporal resolution require adequate integrated processes on landscape‑level. Hence, the goal of this project is to: (i) develop and validate a standalone spray drift model that can be used with other modelling approaches in a modular manner, and (ii) implement that model into SWAT+.

Our spray drift model consists of two parts. First, a mechanistic droplet model predicts the trajectories of individual droplets. Second, a 2D Gaussian diffusion model predicts longitudinal advection as well as vertical and lateral dispersion of droplets. This modelling approach allows for a reasonable tradeoff between accuracy and computational expenses. The following inputs are considered: (i) weather conditions, (ii) drop size distribution, (iii) physio‑chemical properties of the active ingredient, and (iv) operational characteristics (e.g., nozzle count, boom height and width, applied amounts and volumes, and forward driving speed).

It is planned to validate the model against an ensemble of computational fluid dynamics simulations. Additionally, the approach will be evaluated using high resolution SWAT+ models of medium sized agriculturally dominated catchments in Germany. We expect the implementation of spray drift to improve modelling performance for different research questions e.g., the sensitivity of aquatic pesticide concentrations on landscape-level regarding application timing.

How to cite: Fuchs, M., Gebler, S., and Lorke, A.: High resolution exposure modelling at landscape-level – on the development of a mechanistic drift module for SWAT+, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3887, https://doi.org/10.5194/egusphere-egu22-3887, 2022.

09:31–09:38
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EGU22-832
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Presentation form not yet defined
Thorsten Pohlert, Stefan Reichenberger, Sebastian Multsch, Nicholas Jarvis, and Mikaela Gönczi

In Sweden farmers are legally obliged to apply for permits for pesticide use if their land lies within a drinking water abstraction zone. The standalone modelling tool MACRO-DB 4 developed by the Swedish University of Agricultural Sciences (SLU) is available for risk assessment and decision support. MACRO-DB 4 is used by local authorities, farmers/landowners and consultants, and is based on the well-established leaching model MACRO 5.2. However, the software is costly to maintain and slow for end users. Hence, a robust meta-model of MACRO-DB 4 was developed and integrated in a web-based tool (MACRO DB Steg2 v.5) that is fast, easy to maintain, and easy to understand for stakeholders. The meta-model (implemented as an R package) is based on i) a large number of MACRO simulations for the whole agriculturally relevant area of Sweden, and ii) a trilinear interpolation tool. The simulations comprised 18 climates, 72 soils, 1 typical crop (spring cereals), 3 application seasons (spring, summer and autumn), and 150 dummy compounds consisting of a grid of normalized Freundlich coefficient Koc, degradation half-life at reference conditions DT50 and Freundlich exponent. Target variables were i) the mean leaching flux concentration over 20 years at 2 m depth (PECgw), and ii) the 20-year mean concentration in large surface water bodies (PECsw; based on pesticide inputs via drainage and baseflow) . The meta-model performs a trilinear interpolation (in the three-dimensional space of Koc, DT50 and Freundlich exponent) for log10 of PECgw or PECsw, respectively. Different crops are taken into account in the web-based tool by adjusting the pesticide interception fraction according to the BBCH stage of the crop to be modelled at the time of application. In order to identify the most important input factors for PECgw and PECsw, a variance-based Global Sensitivity Analysis (GSA) was performed for the MACRO meta-model using the Sobol’ method. This method allows to i) identify first-order (direct) and higher-order (interaction) effects for each input factor (climate, soil, application season, Koc, DT50 and Freundlich exponent), and ii) rank the input factors according to their importance.

How to cite: Pohlert, T., Reichenberger, S., Multsch, S., Jarvis, N., and Gönczi, M.: Global Sensitivity Analysis for a MACRO Meta-Model for Swedish Drinking Water Abstraction Zones, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-832, https://doi.org/10.5194/egusphere-egu22-832, 2022.

09:38–09:45
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EGU22-4541
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ECS
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On-site presentation
Guillaume Metayer, Cecile Dages, Jean Stephane Bailly, David Crevoisier, and Marc Voltz

The use of pesticides in agriculture leads to widespread contamination of various environmental compartments. Surface water contamination represents a major environmental and health risk to manage. Models are a valuable tool for quantifying levels and temporal dynamics of contamination and for identifying and locating the physico-chemical processes involved in pesticide fate. The use of a model requires to know its performance for a given objective. Models simulating pesticide transfers to surface waters have generally been validated either in the laboratory or on a small scale (Gao et al., 2004, Joyce et al., 2010), or at field scale on mass export of discrete floods (Young and Fry, 2019), or at catchment scale on average concentrations or mass exports with minimum daily resolution (Wang et al., 2019). To our knowledge none have been evaluated on multi-year and field-scale databases. MHYDAS-Pesticide-1.0 is a continuous distributed mechanistic model used to simulate water and pesticide transfers from agricultural plots to the river system. The aim of this study is to evaluate at field scale the performance of this model to reproduce multi-year chronicles of runoff water contamination by a post-emergence herbicide intensively used in viticulture, glyphosate. The model was applied to a vineyard plot belonging to the Long-Term Observatory OMERE (Molénat et al., 2018), which outlet runoff discharge and glyphosate concentration have been monitored since 2001. The evaluation was conducted sequentially: the model was first evaluated on its performance in reproducing the runoff hydrographs observed at the plot outlet, then on its performance in simulating the temporal dynamics of glyphosate concentrations measured in runoff water. In both cases, the evaluation included a calibration and a validation step. The simulations were compared to data acquired between 2001 and 2017. The first three years were used for calibration and the following years for validation. To compare simulation results to observations, we considered variables of interest at flood event scale : the flood volume, the peak outflow and the mean glyphosate concentration. Goodness of fit was evaluated considering classical statistical performance indicators such as percent bias and Nash-Sutcliffe efficiency. These indicators were adapted to decrease the weight of the highest values relative to the lowest values. First calibration-validation results of saturated conductivity and height of surface detention enabled to identify a change of soil surface state during the assessment period that was corroborated by field observations. Taking this change into account by specific calibrations, the model reproduced very well runoff heights and peaks during the validation periods. The reproduction of concentration dynamics was also very satisfactory after calibration of glyphosate degradation kinetic and sorption coefficients and depth of the mixing layer between topsoil and surface runoff. This study demonstrates the ability of MHYDAS-Pesticide-1.0 to simulate multi-year time series of pesticide concentrations in surface water. It also provides a better understanding of the hierarchy of transfer processes occurring at the plot scale.

How to cite: Metayer, G., Dages, C., Bailly, J. S., Crevoisier, D., and Voltz, M.: Assessment of the MHYDAS-Pesticide-1.0 model in simulating pesticide concentrations in surface waters at plot-scale continuously over decades, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4541, https://doi.org/10.5194/egusphere-egu22-4541, 2022.

09:45–10:00
Coffee break
Chairpersons: Matthias Gassmann, Sylvain Payraudeau
Inorganic micropollutants
10:20–10:27
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EGU22-11685
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Presentation form not yet defined
Sylvain Payraudeau, Fatima Meite, and Gwenaël Imfeld

Zinc-based and Cu-based fungicides are widely used in European vineyards to prevent fungal diseases. The soil management and rainfall characteristics influence the runoff export of copper (Cu) and zinc (Zn) from vineyard plots, although quantitative field studies are mostly missing. The runoff exports of Zn and Cu from Northern vineyard plots (Rouffach, Alsace, calcareous-loamy soils with pH = 8.0) under conventional and alternative soil management were compared during two contrasting vine-growing seasons. The conventional management included standard soil maintenance with chemical weeding, whereas the alternative management involved the conversion to organic farming with a mechanical soil management. Cu in top-soil, i.e. the first 5 cm, reached 103.6 ± 19.1 and 70.8 ± 7.8 kg Cu ha-1 for conventional and alternative plots, respectively, mirroring accumulation since decades. Zn in top-soil reached 70.8 ± 16.4 and 63.9 ± 7.8 kg Cu ha-1 for conventional and alternative plots, respectively. No Zn applications on the conventional and alternative plots were recorded during the two growing seasons. Overall, our results emphasize that destructuring of the surface soil layer and tillage preceding a storm event largely influences water flows and exports of both dissolved and solid-bound Cu and Zn. Plowing work on the organic plot a few days before a most intense storm event resulted in significant mass export, accounting for 99% and 95% of the total mass exported during the vine-growing season for Cu and Zn, respectively. However, grass cover on one out of two inter-rows limited runoff volumes to a maximum runoff coefficient of up to 1.4% over the two vine-growing seasons. The seasonal export of Cu and Zn occurred mainly by surface runoff as the monthly water storage of the soil was lower than the water holding capacity, thereby limiting vertical flows in both management modes. The mass export of solid-bound Cu and Zn contributed to more than 95% of total export of both Cu and Zn from the vineyard plots. The seasonal Cu and Zn exports ranged from 0.001 to 0.05% of historical Cu and Zn in the top-soil, raising the issue of both Cu and Zn accumulation in vineyard soils. Altogether, this study underscores that soil mechanical management preceding a storm event largely affects Cu and Zn export, although Cu and Zn fluxes in runoff from the alternative management are globally lower. 

How to cite: Payraudeau, S., Meite, F., and Imfeld, G.: Soil management affects copper and zinc export in runoff from Northern vineyard plots (Rouffach, Alsace, France), EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11685, https://doi.org/10.5194/egusphere-egu22-11685, 2022.

10:27–10:34
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EGU22-4540
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ECS
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Presentation form not yet defined
Aaron Brewer, Ishai Dror, and Brian Berkowitz

Rare earth elements (REEs) are an emerging pollutant whose increasing use in various technological applications causes increasing risk of environmental contamination. Electronic waste (E-waste) could be one major source of REE pollution, as E-waste typically contains elevated REE concentrations and is often handled in unsafe and environmentally hazardous ways. Here, a series of leaching assays revealed that <1% of REEs available in a representative E-waste were released except at acidic conditions (pH 2) rarely observed in nature. If REEs are leached from E-waste, the extent of their spread in the environment will depend, in large part, on their mobility through porous media. Measurements of REE transport through saturated sand demonstrated extremely limited mobility except at acidic conditions (pH 2), though significant REE retention by the substrate still occurs at this low pH. Similar experiments in a natural soil found REE mobility to be even lower in that substrate, with complete REE retention even after the passage of up to 215 pore volumes of a 500 ppb REE solution. Aqueous REEs are therefore not expected to be highly mobile in the environment. The presence of natural or anthropogenic nanoparticles may affect REE behavior during leaching and/or transport. Measurements indicated that silica nanoparticles can increase the concentration of fluid-mobile REEs during E-waste leaching, but both plastic and silica nanoparticles have a negligible effect on REE transport. Ultimately, the experiments and analysis presented here suggest that the threat of REE pollution from E-waste is minimal except at specific sites with unusual environmental conditions.

How to cite: Brewer, A., Dror, I., and Berkowitz, B.: Electronic waste as a source of rare earth element pollution: Leaching, transport in porous media, and the effects of nanoparticles, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4540, https://doi.org/10.5194/egusphere-egu22-4540, 2022.

10:34–10:41
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EGU22-8261
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On-site presentation
Mohamed Yassin, Mohammed Benaafi, Bassam Tawabini, and Sani Abba

Soils may preserve metals from different sources that might pollute the environment. Hence, it is very important to assess the concentration of the geochemical elements of areas where intensified agriculture and industrial activities. This study involved the spatial assessment of topsoil contamination with trace metals in selected areas in Eastern Province, Saudi Arabia. To achieve this objective, more than 130 samples of topsoil from residential, industrial, and agricultural areas were collected and analysed. Inductively coupled plasma - optical emission spectroscopy (ICP-OES) was used to analyse the samples for various trace metals. Moreover, different artificial intelligence (AI) models such as artificial neural network (ANN) were applied to estimation the zinc (Zn), copper (Cu), chromium (Cr), and lead (Pb) using feature-based input selection. The experimental results depicted that the average concentration levels of HMs were as follows: Chromium (Cr) (31.79±37.9 mg/kg), Copper (Cu) (6.76±12.54 mg/kg), Lead (Pb) (6.34±14.55 mg/kg), and Zinc (Zn) (23.44±84.43 mg/kg). The modelling accuracy showed that agricultural and industrial stations performance merit with goodness-of-fit ranges of 51-91% and 80-99%, respectively. This study concluded that AI models might be successfully applied for the quick estimation of soil trace metals and for decision support system.

How to cite: Yassin, M., Benaafi, M., Tawabini, B., and Abba, S.: Assessment of the variation of soil trace metals using artificial intelligence: A case study from Eastern Province, Saudi Arabia, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8261, https://doi.org/10.5194/egusphere-egu22-8261, 2022.

Risk mitigation measures
10:41–10:48
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EGU22-106
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ECS
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On-site presentation
Anuradha Anuradha and Brijesh Kumar Yadav

Heavy metal contaminated water is a major threat to human and aquatic life. Chromium is a toxic heavy metal discharged into surface water mainly due to industrial applications. Physico-chemical technologies to treat chromium-contaminated waters are expensive, especially for developing countries. Macrophytes-based phytoremediation is a competent method of water treatment that is simple, cost-effective, and provides satisfactory results. In the present study, we investigated the potential of macrophyte Eichhornia crassipes, commonly known as water hyacinth, to accumulate chromium concentrations from water. We conducted a hydroponics experiment for ten days under controlled laboratory conditions to examine the hyperaccumulation potential of the species. The experiment results showed that Eichhornia crassipes is an excellent accumulator of chromium. The maximum concentration was found in the plant's roots with small amounts in the shoots and leaves. These results demonstrate that E. crassipes can provide an efficient and environment-friendly option of remediating chromium-contaminated surface water bodies.

How to cite: Anuradha, A. and Yadav, B. K.: Eichhornia crassipes macrophytes for treatment of heavy metal contaminated water, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-106, https://doi.org/10.5194/egusphere-egu22-106, 2022.

10:48–10:55
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EGU22-1960
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Virtual presentation
Ming Xu, Xing-hao Huang, Peng Gao, Hao-qiang Chen, Xiao-xiao Shen, Wu-hui Zhu, Yan-yan Zhang, and Guang-qiu Jin

Estuarine sediments are reservoirs of antibiotic resistance genes (ARGs). However, spatiotemporal variations in the response mechanism between ARGs removal and the microbial community under the bio-ecological restoration of estuaries remain unclear. In this study, spatiotemporal hydrological and water quality data were collected from a 14,000 m2 estuary located in the downstream of the Yangtze River to construct a MIKE 21 hydrodynamic model. Based on this, a bio-ecological combined restoration technology of estuaries was constructed and has been running steadily for more than two years. Water and sediment samples in different sections of the bio-ecological restoration and in different seasons were collected to reveal the spatiotemporal variations and response mechanism of ARGs and the microbial community. In total, nine typical ARGs, intI1, and the microbial community were investigated by quantitative polymerase chain reaction and evaluation of the 16S rRNA. The results revealed that the ecological restoration improved the hydrodynamic conditions of the estuary, mitigated the accumulation of pollutants, and considerably removed macrolide (ermC: 63.17–99.06%, ermB: 30.32–96.29%), sulfonamide (sul2: 31.25–98.91%), and tetracycline (tetA: 26.93–98.68%, tetW: 64.86–94.99%) resistance genes. Meanwhile, the ARGs exhibited significant spatiotemporal variation, and that the dominant genes in the estuarine sediments were sulfonamide, macrolide, and tetracycline resistance genes. The absolute abundances of the ARGs followed the order winter > summer > autumn > spring. Proteobacteria (45.33%), Chloroflexi (11.24%), and Acidobacteria (9.99%) were the dominant phyla in the estuary sediment. Massilia and Pseudarthrobacter were the dominant genera in spring, whereas the genera belonging to Proteobacteria were dominant in the other three seasons. Proteobacteria, which was positively correlated with sul1, sul2, tetA, tetM, tetW, ermB, ermC, qnrS, and floR, was recognized as typical antibiotic resistant bacteria, while Thiobacillus, Massilia, and Dechloromonas were found to be potential host genera. Network analysis also revealed the possibility that sul1, tetA, and ermC can act as multi-antibiotic resistance genes. Furthermore, environmental factors including total phosphorus, total nitrogen, and heavy metal concentration also affected ARG dissemination by affecting microbes (p ≤ 0.05). Overall, our findings provided practical evidence for the role that bio-ecological restoration plays in controlling the propagation of ARGs by regulating the microbial community in the estuary sediment.

How to cite: Xu, M., Huang, X., Gao, P., Chen, H., Shen, X., Zhu, W., Zhang, Y., and Jin, G.: Spatiotemporal variations in the response mechanism between ARGs removal and the microbial community in estuary sediments under the bio-ecological restoration, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1960, https://doi.org/10.5194/egusphere-egu22-1960, 2022.

10:55–11:02
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EGU22-5848
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ECS
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On-site presentation
Du Phuc Tho Dang, Liliane Jean-Soro, and Béatrice Béchet

The management of urban stormwater runoff has moved from approaches narrowly focused on reducing flooding to approaches more focused on improving water quality. From impervious surfaces, stormwater is often diverted into retention ponds where sedimentation is used to limit the impact on waterbodies by trapping particulate pollutants. Trace elements are of particular interest because of their potential toxicity. The composition of the sediment varies over time, particularly through the development of vegetation. Ageing has an effect on sediment removal ability of pollutants (Nuel et al., 2018). The aim of this study was to compare the mobility of trace elements in sediments of a retention-infiltration pond before and after its total dredging. The mobility of these pollutants is related to their geochemical fractionation between solid phases which is generally investigated by extraction methods. The single extraction method with ammonium acetate and calcium chloride was applied on sediment samples to quantify the highest labile fraction of these elements (Sakan et al., 2020). The ultrasound assisted sequential extraction based on the procedure proposed by Rauret et al., (2000) and certified by Pueyo et al., (2001) was applied to determine the pollutant distribution among the acid-extractable, reducible, oxidizable fractions of sediments. The ageing effect is examined to explain the global removal ability of sediments. Then, the distribution of trace elements in different solid phases is analyzed in function of the sediment ageing, the mineral composition and granulometry of sediments.

Nuel, M., Laurent, J., Bois, P., Heintz, D., Wanko, A., 2018. Seasonal and ageing effect on the behaviour of 86 drugs in a full-scale surface treatment wetland: Removal efficiencies and distribution in plants and sediments. Science of The Total Environment 615, 1099–1109. https://doi.org/10.1016/j.scitotenv.2017.10.061

Pueyo, M., Rauret, G., Lück, D., Yli-Halla, M., Muntau, H., Quevauviller, Ph., López-Sánchez, J.F., 2001. Certification of the extractable contents of Cd, Cr, Cu, Ni, Pb and Zn in a freshwater sediment following a collaboratively tested and optimised three-step sequential extraction procedure. J. Environ. Monitor. 3, 243–250. https://doi.org/10.1039/b010235k

Rauret, G., López-Sánchez, J.-F., Sahuquillo, A., Barahona, E., Lachica, M., Ure, A.M., Davidson, C.M., Gomez, A., Lück, D., Bacon, J., Yli-Halla, M., Muntau, H., Quevauviller, Ph., 2000. Application of a modified BCR sequential extraction (three-step) procedure for the determination of extractable trace metal contents in a sewage sludge amended soil reference material (CRM 483), complemented by a three-year stability study of acetic acid and EDTA extractable metal content. J. Environ. Monitor. 2, 228–233. https://doi.org/10.1039/b001496f

Sakan, S., Frančišković-Bilinski, S., Đorđević, D., Popović, A., Škrivanj, S., Bilinski, H., 2020. Geochemical Fractionation and Risk Assessment of Potentially Toxic Elements in Sediments from Kupa River, Croatia. Water 12, 2024. https://doi.org/10.3390/w12072024

 

How to cite: Dang, D. P. T., Jean-Soro, L., and Béchet, B.: Evaluation of ageing effect on trace element mobility in sediment of sustainable drainage systems by chemical extractions, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5848, https://doi.org/10.5194/egusphere-egu22-5848, 2022.

11:02–11:09
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EGU22-13039
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Presentation form not yet defined
Rafael Muñoz-Carpena, Stefan Reichenberger, and Robin Sur

Regulatory exposure assessments (EA) are a cornerstone in the registration of new or existing agrochemicals in the EU, USA and many other countries to preserve ecosystem health and water quality. VFSMOD (Muñoz-Carpena et al., 1999; 2004) is a numerical, storm-based design model that quantifies the performance of vegetative filter strips- VFS (grass buffers) to mitigate pesticide runoff into surface waters. The model has been coupled into current USA and EU long-term (20 to 30 yr), higher-tier regulatory pesticide EAs to estimate potential pesticide load reductions by the VFS before entering the aquatic environment. A new comprehensive modeling component has been added to VFSMOD to quantify the fate of pesticides residue on the VFS between events in the context of long-term simulations. The aim of this study is to present the verification of the assumptions and accuracy of the new pesticide residue component within VFSMOD in the context of continuous simulations by exploring a wide range of conditions (Koc, half-life, remobilization processes) of importance to improve current understanding of quantitative mitigation of pesticides in the regulatory environment.  The results show the complex interaction in the VFS amongst surface pesticide runoff, sedimentation, infiltration and leaching, degradation, evapotranspiration and soil moisture change, and mixing layer remobilization that produces emergent behavior in the amount of pesticide residue potentially remobilized in the next event in the series.

How to cite: Muñoz-Carpena, R., Reichenberger, S., and Sur, R.: Importance of surface pesticide residues in the quantitative mitigation of pesticides with vegetative filter strips: VFSMOD development and analysis, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13039, https://doi.org/10.5194/egusphere-egu22-13039, 2022.

11:09–11:16
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EGU22-628
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Presentation form not yet defined
Stefan Reichenberger, Robin Sur, Stephan Sittig, Sebastian Multsch, Álvaro Carmona-Cabrero, and Rafael Muñoz-Carpena

The most widely implemented mitigation measure to reduce transfer of pesticides and other pollutants to surface water bodies via surface runoff are vegetative filter strips (VFS). The most commonly used model for assessing the reduction of surface runoff, eroded sediment and pesticide inputs into surface water by VFS is VFSMOD, which simulates reduction of total inflow (∆Q) and reduction of incoming eroded sediment load (∆E) mechanistically. These variables are subsequently used to calculate the reduction of pesticide load by the VFS (∆P). Since errors in ∆Q and ∆E will propagate to ∆P, for strongly sorbing compounds, an accurate prediction of ∆E is crucial for a reliable prediction of ∆P. The most important parameter characterizing the incoming sediment in VFSMOD is the median particle diameter d50, which is currently fixed to 20 µm in the regulatory tool SWAN 5.01. The objective of this study was to derive an improved, generic d50 parameterization methodology that can be readily used for regulatory VFS scenarios.

A test dataset of d50 values and explanatory variables has been compiled from heterogeneous data sources. The established test dataset (n = 93) was analysed using Machine Learning techniques (Random Forest, Gradient Boosting) and multiple regression analysis (MLR). With the help of the knowledge gained with Machine Learning, a MLR equation with six predictor variables was established and thoroughly tested. Since three of the predictors are event-specific (eroded sediment yield, rainfall intensity and peak runoff rate), the predicted d50 values vary between runoff events according to their magnitude and intensity.

A modified version of SWAN-VFSMOD containing the improved d50 parameterization method was run for a number of contrasting compounds and application scenarios. The obtained ∆E and ∆P values as well as the resulting pesticide concentrations in surface water and sediment (PECsw/sed) were compared with the current FOCUS step4 approach.

How to cite: Reichenberger, S., Sur, R., Sittig, S., Multsch, S., Carmona-Cabrero, Á., and Muñoz-Carpena, R.: Impact of a new sediment parameterization method in VFSMOD on PECsw/sed in FOCUS step4, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-628, https://doi.org/10.5194/egusphere-egu22-628, 2022.

11:16–11:23
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EGU22-13012
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ECS
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Virtual presentation
John Howe and Rafael Munoz-Carpena

VFSMOD, a numerical storm-based vegetative filter strip (VFS) design model, calculates pesticide mitigation from runoff through VFS in regulatory long-term ecotoxicological exposure assessments. After each storm, the model calculates degradation in the hiatus period and currently adopts a risk-conservative approach of full remobilization of surface pesticide residues during following storms. For highly-sorbed chemicals, although risk-conservative, this assumption has been shown to be unrealistic and a revised mechanistic modeling approach that produces accurate estimates across a wide range of chemicals is sought.  To test the ability of the revised modeling approach to predict VFS efficacy accurately over time, a mesoscale experiment was designed using triplicated 1.2Lx0.35Wx0.5D m soil boxes with VFS planted on the surface.  The device was instrumented to quantify how different types of pesticides are remobilized from the VFS surface over consecutive rainfall events with a hiatus in between. A rainfall simulator provides uniformly distributed precipitation input at 5-year storm intensity and a lateral inflow spreader provides runoff entering the upper side of the VFS. A chemical tracer is added to the pesticide and sediment inflow suspension and tracked through the system using a longitudinal grid of 12 soil moisture and electrical conductivity sensors, and 4 automatic flow meters at 3 drainage and 1 surface runoff outlets per box. Infiltration and runoff are quantified to close the mass balance.  The use of advanced instrumentation is vital to achieve data with high spaciotemporal resolution for analysis. Due to the complex nature of the VFS environment, system subcomponents are sequentially tested for water traceability. Before the addition of pesticides, the system was tested with water and tracer. Preliminary mass balance results will ensure all water is traceable through the system, which will be essential during later experimentation with pesticides.

How to cite: Howe, J. and Munoz-Carpena, R.: PESTICIDE REMOBILIZATION in VEGETATIVE FILTER STRIPS USING MESOSCALE MULTI-EVENT EXPERIMENTATION, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13012, https://doi.org/10.5194/egusphere-egu22-13012, 2022.

11:23–11:30
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EGU22-639
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Highlight
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Presentation form not yet defined
Michael Klein, Stefan Reichenberger, Isabel O'Connor, Simon Spycher, Stephan Sittig, Sebastian Multsch, Kai Thomas, Jens Flade, and Dietlinde Großmann

Surface runoff from agricultural fields is a major input pathway of pesticides into surface waters. The aim of this project was to i) analyze the effectiveness of various mitigation measures to reduce pesticide runoff and erosion inputs into surface waters, ii) assess the suitability of the measures found effective for use in the quantitative environmental exposure assessment for authorization of plant protection products (PPP), and iii) make recommendations how the potentially suitable measures could be applied in risk assessment of PPP in Germany. Following a literature analysis, 16 risk mitigation measures were presented to five experts for evaluation of effectiveness, cost-effectiveness, controllability, current distribution and dissemination potential. Measures finally selected for quantitative analysis belong to 3 groups: vegetative filter strips (VFS), soil conservation measures and micro-dams in row crops. Subsequently, the effectiveness of the recommended measures was evaluated based on experimental data using different statistical methods (e.g. CART, MLR, graphical methods).

The quantitative analysis confirmed the effectiveness of VFS and micro-dams. For soil conservation measures (especially mulch-till), the evaluated data showed highly variable results. This was partly caused by the heterogeneity of the experimental data, which also made it difficult to aggregate the results of different studies.

The following conclusions were drawn: Both VFS and micro-dams can be recommended for application in quantitative environmental exposure assessment for pesticides.  However, infiltration and sedimentation in VFS should be simulated with a mechanistic model such as VFSMOD. The effect of micro-dams can be modelled as a reduction of the runoff Curve Number (CN). The runoff modelling should be carried out with a model such as PRZM which adjusts the CN daily based on soil water content.

How to cite: Klein, M., Reichenberger, S., O'Connor, I., Spycher, S., Sittig, S., Multsch, S., Thomas, K., Flade, J., and Großmann, D.: Evaluation of the effectiveness of mitigation measures to reduce pesticide inputs into surface water bodies via surface runoff and erosion, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-639, https://doi.org/10.5194/egusphere-egu22-639, 2022.

11:30–11:45