van der Linden AMA, van Os EA, Wipfler EL, Cornelese AA, Ludeking DJW, Vermeulen T
RIVM Report 2015-0128
New methodologies for the assessment of the exposure of aquatic organisms to plant protection products (PPP) after their use in substrate cultivations in greenhouses were developed. The relevant protection goal is the aquatic ecosystem. In contrast with the current methodology, which was not specifically developed for substrate cultivations, the new methodology accounts for two major potential emission routes: the discharge of recirculation water and the discharge of filter cleaning water into surface water. The Dutch Ministry of Economic Affairs and the Ministry of Infrastructure and the Environment initiated this research to develop an exposure assessment methodology suitable for substrate cultivations in greenhouses. The new methodology assigns substrate cultivations to four different crop groups according to their water requirement and sodium tolerance. For each of the groups an assessment scenario was developed, taking into account nutrient emission limits. A representative discharge-receiving ditch was selected and parameterised. For each scenario and PPP application method, the Greenhouse Emission Model calculates water flows and PPP behaviour in the growing system, emissions of water and PPP to surface water and the fate of the PPP in the surface water. The resulting concentrations in surface water can be used to decide on the authorisation of PPPs.