FOCUS S Water Scenarios WG Meeting, Brussels, 20-21 January ...

SANCO/4802/2001-rev.2 final (May 2003)
|[pic] |EUROPEAN COMMISSION |
| |HEALTH & CONSUMER PROTECTION DIRECTORATE-GENERAL |
| | |
| |Directorate E - Food Safety: plant health, animal |
| |health and welfare, international questions |
| |E1 - Plant health |
focus SURFACE WATER SCENARIOS IN THE EU EVALUATION PROCESS UNDER 91/414/EEC.
Report prepared by the FOCUS Working Group
on Surface Water Scenarios Authors: J. Linders, P. Adriaanse, R. Allen, E. Capri, V. Gouy, J.
Hollis, N. Jarvis, M. Klein, P. Lolos, W.-M. Maier, S. Maund, C.
Pais, M. Russell, L. Smeets, J.-L. Teixeira, S. Vizantinopoulos,
D. Yon Acknowledgements The authors would like to thank the many people who have assisted their
work by kindly providing information, data and help in carrying out many
test runs of the models. Without their contributions this work could not
have been completed. Working Group Membership P. Adriaanse Alterra, NL R. Allen Bayer CropScience, USA E. Capri Universitá Cattolica del Sacro Cuore, I V. Gouy Cemagref, F J. Hollis, secretariat NSRI, Cranfield University UK N. Jarvis SLU, S M. Klein Fraunhofer-Institute for Molecular Biology & Applied Ecology, D J. Linders, chairman RIVM, NL P. Lolos (from June 2000) NAGREF, GR W.-M. Maier (from September, 1988) European Commission, B S. Maund Syngenta, UK C. Pais (from March 2001) Instituto de Hidráulica, Engenharia Rural e
Ambiente, P M. Russell DuPont Crop Protection, USA L. Smeets (To September, 1988) European Commission, B J.-L. Teixeira (To March 2001) Instituto de Hidráulica, Engenharia Rural
e Ambiente, P S. Vizantinopoulos (To June 2000) National Agricultural Research
Foundation, GR D. Yon Dow Agrosciences, UK
Citation Those wishing to cite this report are advised to use the following form for
the citation: 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. FOREWORD Introduction This foreword is written on behalf of the FOCUS Steering Committee in
support of the work of the FOCUS Working Group on Surface Water Scenarios.
This work is reported here for use in the European review of active
substances of plant protection products under Council Directive 91/414/EEC.
FOCUS stands for FOrum for the Co-ordination of pesticide fate models and
their USe. The FOCUS forum was established as a joint initiative of the Commission and
industry in order to develop guidance on the use of mathematical models in
the review process under Council Directive 91/414/EEC of 15 July 1991
concerning the placing of plant protection products on the market and
subsequent amendments. In their introductory report, the FOCUS Steering
Committee mentions the need for guidance on the estimation of Predicted
Environmental Concentrations (PECs) using mathematical models. To answer
this need, three working groups were established and subsequently published
guidance documents dealing with: . Leaching Models and EU Registration (FOCUS, 1995); . Soil Persistence Models and EU Registration (FOCUS, 1996) . Surface Water Models and EU Registration of Plant Protection Products
(FOCUS, 1997) The guidance document on Surface Water Models included three important
recommendations: In order to develop typical scenarios for surface water fate modelling
including inputs from spray drift, drainage and run-off within the EU and
to subsequently assess the distribution of 'worst case scenarios' following
use of a plant protection product the development of appropriate EU
databases of aquatic environments adjacent to agricultural land, soil
types, topography, crops and climate is needed. Whilst standard scenarios are not available for the assessment of PECs in
surface water and sediment, it is recommended that all model calculations
make careful and reasoned consideration of the definition of the
scenario(s). Justification for all selections must be made. Standard scenarios for the European Union should be developed. Based on these recommendations, the Steering Committee established in 1996
the current FOCUS Working Group on Surface Water Scenarios and decided to
develop a series of standard agriculturally relevant scenarios for the
European Union that can be used with these models to fulfil the
requirements for calculating PECs.
Remit to the Working Group The Steering Group formulated the following remit to the group: " Objective Develop scenarios that can be used as a reliable input for modelling in
the EU registration process as proposed by the FOCUS Surface Water
Working Group in the step by step approach proposed in their report.
Background The registration procedure for plant protection products according to the
Council Directive 91/414/EEC includes the possibility of using models for
the calculation of Predicted Environmental Concentrations in surface
water (PECsw). Depending on PECsw, further investigations, e.g.
ecotoxicity tests, have to be conducted in order to demonstrate
acceptable risk to aquatic organisms. A step by step procedure for the calculation of PECsw has been described
in the report of the FOCUS Surface Water Modelling Working Group. The
procedure consists of four steps, whereby the first step represents a
very simple approach using simple kinetics, and assuming a loading
equivalent to a maximum annual application. The second step is the
estimation of time-weighted concentrations taking into account a sequence
of loadings, and the third step focuses on more detailed modelling taking
into account realistic "worst case" amounts entering surface water via
relevant routes (run-off, spray drift, drainage, atmospheric deposition).
The last (4th) step considers substance loadings as foreseen in Step 3,
but it also takes into account the range of possible uses. The uses are
therefore related to the specific and realistic combinations of cropping,
soil, weather, field topography and aquatic bodies adjacent to fields. A critical component of any modelling procedure is the identification of
relevant scenarios to characterise the environmental conditions
determining model input parameters. It would be ideal, when calculating PECsw for European registration
purposes, if modellers could draw on a limited number of well-defined
European scenarios. Such scenarios do not exist. The entry routes of plant protection products into surface water will
differ considerably from country to country within the EU. To identify
the routes, region specific scenarios have to be defined considering the
target crop, hydrological situation, surface water body, field
topography, climatic, soil and management regime. To complete this task,
another FOCUS Working Group is needed. The existence of standard scenarios will make a uniform procedure for
assessing the PECsw of plant protection products in surface water
possible." The FOCUS Working Group on Surface Water Scenarios has now completed this
work, which is represented in detail in this report and the associated
computer files. It can be said that the objectives set by the Steering
Committee have been met.
Use of the FOCUS Surface Water Scenarios and interpreting results
Although the approach developed by the FOCUS working group meets the
objectives set, it is important to keep in mind some general rules when the
models are used and their results are interpreted. What the standard scenarios do and do not represent
The contamination of surface waters resulting from the use of an active
substance is represented by ten realistic worst-case scenarios, which were
selected on the basis of expert judgement. Collectively, these scenarios
represent agriculture across Europe, for the purposes of Step 1 to 3
assessments at the EU level. However, being designed as "realistic worst
case" scenarios, these scenarios do not mimic specific fields, and nor are
they necessarily representative of the agriculture at the location or the
Member State after which they are named. Also they do not represent
national scenarios for the registration of plant protection products in the
Member States. It may be possible for a Member State to use some of the
scenarios defined also as a representative scenario to be used in national
authorisations but the scenarios were not intended for that purpose and
specific parameters, crops or situations have been adjusted with the
intention of making the scenario more appropriate to represent a realistic
worst case for a wider area. The purpose of the standard scenarios is to assist in establishing relevant
Predicted Environmental Concentrations (PECs) in surface water bodies which
- in combination with the appropriate end points from ecotoxicology testing
- can be used to assess whether there are safe uses for a given substance.
The concept of the tiered approach to surface water exposure assessment is
one of increasing realism with step 1 scenarios representing a very simp