The aim of the joint Finnish-Latvian project was to develop an interdisciplinary view on the factors affecting water quality in Latvia, but also influencing the Baltic Sea. Project tried to integrate not only analysis of socio-economic situation in Latvia and actual human impacts on water quality with process of development of environmental protection system, but also possible responses of aquatic systems and loadings to the Baltic Sea focusing on the influences coming from cities of Latvia, with the modelling approach. Another goal of this project was to summarize exiting information on environmental quality, environmental protection system in Latvia during las decades - transition period and on how the historical heritage and the restructuring process in society has influenced environment and how these activities can influence the development in future.