Monitoring of chemical pollutants following the European Water Framework Directive gives only marginal attention to their
partitioning among particulate, colloidal and truly dissolved phases, which is a crucial phenomenon in aquatic environments.
Proper consideration of issues related to pollutant partitioning would increase both the quality of monitoring data and their
usefulness for implementing adequate management strategies. This contribution highlights and discusses conceptual and technical challenges in properly considering pollutant partitioning in ecological and chemical assessment. We also consider the need to improve integration of monitoring programs and fundamental research and suggest how to achieve such integration.