On the societal level, risks are the result of collective processes of definition. Accepted risks are mainly the output and secondarily the (scientific) input of these processes. As a consequence, in this paper the question of risk management of the nitrate burden to ground and drinking water is analysed within the framework of comparative policy analysis. Various actors pursue their respective interests in different policy arenas within the given rules of the policy game. The impacts of the policy outputs on the policy addressees, namely farmers and water companies, (substantially) determine the level of actual risk. Different national regulatory styles and traditions towards nitrate regulation shape the policy outputs. Consequently, the assumption or normative postulate of a rational (scientific) risk assessment and risk management appears to be utterly heroic and, in the end, misleading.