Lillån
Statusbedömning enligt EU
In Sweden, the County Administration board is responsible for improving the water quality in lakes and watercourses according to the European Union Water Framework Directive. In Västmanland county, where river Lillån is situated, the County Administration of Västmanland have the main responsibility for the aquatic environment in that area. The knowledge about the different watercourses in the chatchment of river Lillån is today limited. The aim with this study was to evaluate the ecological quality of River Lillån based on water chemistry analyses and benthic fauna investigations. The aim was also for the benthic fauna to compere different samplingsites and sampling methods with each other in order to see how the species composition changes in the river, and to see the advantages and disadvantages with different sampling tecniques. The methods used for the assessment was presented in a handbook composed by the Swedish Environmental Protection Agency. The results of the study showed that Lillån have good quality concerning acidity and the general ecological status. The benthic fauna investigations indicated high levels of nutrients and thereby resulted in poor status concerning that parameter. The conclusion of the study was that river Lillån does not fulfill the criteria of good status according to the Water Framework Direcive composed by the European Union. Keywords: Water directive, water quality evaulation, benthic fauna, acidification, nutrients, methods for sample-taking.Nyckelord: Vattendirektiv, statusbedömning, bottenfauna, försurning, näringsämnen, provtagningsmetoder.