Assessing the coverage of surface water exposure via drainage by the FOCUS scenarios in France

Garcia, L.1*, Erzgräber, B.1, Guyot, C.2, Hammel, K.2, Huang, M-X.3, Loiseau, L.4,

O’Carroll, N.5, Reiher, W.6, Roulier, S.7, Saludas, J.4

1 BASF SE, Speyerer Straße 2, 67117 Limburgerhof, Germany 2 Bayer CropScience, Alfred-Nobel-Strasse 50, 40789 Monheim, Germany 3 Dupont Crop Protection, 1090 Elkton Rd., Newark, Delaware, USA 4 Syngenta, Schwarzwaldallee 215, CH-4002 Basel, Switzerland 5 Dow AgroSciences,6, rue Jean-Pierre Timbaud, 78067 St Quentin En Yvelines, France 6 Dr Knoell Consult GmbH, Marie-Currie-Str. 8, 51377 Leverkusen, Germany 7 Makhteshim-Agan, 2 rue Troyon, 92316 Sèvres, France * lucas.garcia@basf.com Introduction

In France, the potential exposure of surface water to Plant Protection Products (PPP) is assessed using the European FOCUS Surface Water scenarios (FOCUS, 2001).

In 2011, the French Agency for Food, Environmental and Occupational Health and Safety (ANSES - Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail), in charge of the risk assessment of Plant Protection Products, evaluated the relevance of the FOCUS drainage scenarios in France. This work showed that significant areas of drained land are not directly represented by any of the six D scenarios (ANSES, 2011). This outcome implies an unknown level of uncertainty in surface water exposure in these areas of drained land.

The aim of the present work is to assess to which extent the FOCUS D scenarios are nevertheless protective for those critical areas highlighted by ANSES. Modelling approach

To assess the coverage of the drainage risk in France by the FOCUS D scenarios, specific drainage scenarios relevant for these critical areas were established. To do so both soil and climatic components of these areas were addressed: (i) soils were identified using the European soil database (ESDB v2) and the FOCUS criteria to derive the drainage (D) soil scenarios, (ii) these soils were overlapped with drained acreage as reported in the French agricultural census (Agreste, 2001), with a selection criterion of over 10% of the agricultural surfaces effectively drained, (iii) the soil components were parameterised by selecting the FOCUS D scenario soil profile parameterisation corresponding to the type of soil identified in (i), and finally (iv) weather data were extracted from relevant MARS database grids corresponding to the determined areas. It resulted in the definition of eight “Geographical Areas” (GA) described by ten modelling scenarios.

Using these scenarios, simulations using the MACRO and TOXSWA models were conducted to establish maximum PECs in surface water bodies for several FOCUS dummy substances. “Winter cereals” was selected as representative crop since it is parameterised in all six FOCUS D scenarios. Drift entries were eliminated from the simulations. In accordance with the FOCUS approach, an evaluation year was defined. To account for the influence of the application date, twelve simulations (one for every month) were run per scenario. Results

To clarify the question whether the FOCUS D scenarios adequately cover, i.e. are protective, for the potential exposure of surface water via drainage in the critical areas identified by

ANSES, the PECsw obtained in these specific simulations were compared to the concentrations of the classical FOCUS D scenarios.

The results for FOCUS dummies D (DT50 = 30 d, Koc = 10 mL g-1) and I (DT50 = 300 d, Koc = 1000 mL g-1) are presented in the following figures:

Figure 1 a & b: Maximum PECsw (in μg L-1) as given by TOXSWA for all simulations for specific GAs scenarios (GAx) and FOCUS D scenarios (Dx). Each horizontal dash thus represents the maximum PECsw for a given application month associated to a given water body. Greyed out areas of the plot highlight heavy clay soil scenarios

The results show that the potential risk of contamination of surface water via drainage in the areas identified by ANSES is covered by the existing FOCUS D scenarios. Only one extreme concentration in GA1 scenario for an application in November is higher than PECsw calculated with FOCUS scenario. As for the original FOCUS D scenarios (FOCUS, 2001), the GAs show a clear clustering of sensitive areas, all bound to heavy clay soils, giving significantly higher PECsw. References

Agreste, 2001. Recensement agricole 2000 - L’inventaire – France métropolitaine (CD-Rom).

ANSES, 2011, Groundwater and surface water exposure assessment for France, 13th International Fresenius AGRO Conference: Behaviour of Pesticides in Air, Soil, and Water. 27 and 28 June 2011, Mainz/Germany.

ESDB v2. http://eusoils.jrc.ec.europa.eu/ESDB_Archive/ESDB/

FOCUS, 2001. FOCUS Surface Water Scenarios in the EU Evaluation Process under 91/414/EEC”. Report of the FOCUS Working Group on Surface Water Scenarios, EC Document Reference SANCO/4802/2001-rev.2. 245 pp

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