The article analyses implementation of the urban waste water treatment directive 91/271/eec in four member states (germany, the netherlands, spain and the united kingdom) and the compliance responses made to the national policies in which the directive is implemented. National policy features heavily influenced compliance choices and the implementation of the directive, as did the characteristics of the water works that were in place. In germany the directive accelerated improvement programmes but did not really alter them. In spain it contributed to changes in the organizational structure and to the development of improvement programmes. In england and wales it led to an alteration of compliance choices and national policies. In the netherlands it did not have an impact for the simple reason that it did not require a revision in the wastewater treatment programmes. The article describes compliance choices and appraises them. We discovered several suboptimalities such as the building of expensive, capital-intensive sewage treatment plants, the poor functioning of plants, and the singular focus on wastewater treatment (which were related to civil engineering preferences and national and eu funding arrangements). We also found that possibilities for flexibility in the directive were not well utilized, due to the poor mechanism of information exchange and absence of requirements to weigh the costs against benefits And erp environment.