The environmental fate assessment for plant protection products in the EU centres around three sets of predicted environmental concentrations (PEC) which cover potential exposure in soil, groundwater and surface water. The calculations for each of these compartments at the European level, and for most of the member states, follow the procedures outlined in various FOCUS and EFSA guidance documents and require the use of specific modelling software.
The calculations for soil and groundwater are relatively straightforward to perform and a number of tools have been developed throughout the industry, including EAR’s GRASS tool, to automate much of the manual work associated with conducting them. For many projects, the surface water assessment usually remains the most time-consuming aspect, particularly when it is necessary to fully explore the matrix of mitigation options available i.e. spray-drift buffers, drift-reducing nozzles and vegetated filter strips.
Delivering fast and more robust calculations
In 2020, Eurofins Agroscience Regulatory (EAR) developed a new tool to improve the efficiency of surface water calculations. The tool, known as SWEET (Surface Water Enhanced Efficiency Toolkit), has a number of key features:
It automates all the manual work associated with running surface water calculations at FOCUS Steps 3 and 4.
It provides true parallel-processing across multiple processors (within a single computer or server) and is scalable across separate machines on the same network (grid mode) which results in a much shorter runtime.
Results are automatically processed and extracted into an overall summary spreadsheet to allow quick and easy assessment of the overall exposure profile.
The output files that are often required by the authorities are minimised in size by eliminating the reporting of unnecessary parameters.
It maintains full regulatory acceptability by sitting above and interfacing directly with the existing regulatory models instead of replacing any of the elements.
EAR’s SWEET simultaneously tackles all three bottlenecks in the standard surface water modelling process (user interactions with the models, running of the simulations and processing of the output), to provide a highly streamlined and efficient process. By using SWEET the overall modelling time for a typical project is reduced by a factor of approximately 100. The direct consequences of this for the company’s clients are two-fold:
The turn-around time for urgent modelling requests is significantly reduced.
It is possible to fully investigate those situations where the list of potential use patterns is long without having to compromise by grouping different uses, thereby allowing the mitigation to be fine-tuned to each individual use.
Forthcoming revisions to the guidance based on the recommendations of EFSA(1) will extend the assessment period to 20 years and significantly increase the standard runtimes for surface water modelling, making tools such as SWEET invaluable in the future. SWEET has been built with a modular architecture so that, with relatively few minor updates, it will work with the revised FOCUS models as soon as they are made available.
SWEET represents a quantum leap in surface water modelling capabilities for Eurofins Agroscience Regulatory. It enables a wider range of product use scenarios to be fully explored, minimises delivery times for results and retains regulatory compliance.
Please contact Stuart Watson EAR’s Senior Regulatory Expert, if you are interested in any further details or would like to discuss how SWEET might be useful to support your future projects.
(1) EFSA (European Food Safety Authority), Adriaanse P, Boivin A, Klein M, Jarvis N, Stemmer M, Fait G and Egsmose M, 2020. Scientific report of EFSA on the ‘repair action’ of the FOCUS surface water scenarios. EFSA Journal 2020;18(6):6119, 301 pp. https://doi.org/10.2903/j.efsa.2020.6119
