The ECJ dismissed the Commission’s action against Finland for failure to fulfill obligations by not requiring more stringent treatment of all waste water collected in agglomerations of more than 10 000 population equivalent (p.e) under Directive 91/271/EEC concerning urban waste-water treatment. The Court first noted that Directive 91/271/EEC does not provide for a general obligation to require tertiary treatment of nitrogen from the discharges of every treatment plant of urban waste water from such agglomerations. Further, the Court held that the Commission has failed to establish that the quantity of nitrogen which comes from treatment plants of urban waste water from such agglomerations whose discharges flow into the Gulf of Bothnia contributes to eutrophication in the Baltic Sea. Accordingly, the Court concluded that the Commission has failed to prove that Finland was obliged to require tertiary treatment of nitrogen in every treatment plant of urban waste water from agglomerations of more than 10 000 p.e. whose discharges flow into the Gulf of Bothnia.