AQUAPOL is a research project (2003-2005) on the nutrient load and response in water bodies linking to the EU Water Framework Directive. AQUAPOL's main purpose is to develop improved tools for assessing pollution load and ecological status in water bodies. The practicality and usefulness of the tools were examined by testing them in the Kapos catchment in Hungary. The project aims to apply different non-point source pollution models namely: TEOTIL, SWAT, and the simple Source Apportionment method. The strengths, weaknesses and applicability were evaluated. The other main activity is the development of scientific tools for assessing the ecological status of selected water bodies. It involves the delineation of water bodies, the assessment of reference conditions, and the development of potential metrics expressing dose-response relationships between chemical and biological elements. The project aimed to formulate a preliminary system for ecological status classification as well.