Helen Galfi´s research deals with sustainable water management in urban areas with special focus on monitoring stormwater pollution sources and fluxes in storm sewer systems. The recent interest was on stormwater quality measurement techniques and related errors as well as the spatial and temporal variations of stormwater contaminants studied within the research cluster Stormwater & Sewers. The research includes topics concerning automatic sampler contamination during indicator bacteria monitoring in storm sewers, microorganisms-, nutrients- and inorganic pollutant sources in urbanized catchments with varying land use and development degree in cold climate as well as modeling seasonal and local variation of pollutant fluxes with special emphasis on solids and heavy metals. The previous research interest during master studies was the assessment of groundwater quality and their compliance with the European water guidelines, especially the nitrate directive. The initial research was broadened during the PhD studies to cover monitoring and pollution in urban storm sewers for a variety of contaminants impairing the receiving environment.