The paper gives a brief overview on the current state of the art of cost-efficiency analysis
concerning measures to reduce nutrient immissions into the Baltic Sea. On the basis of a literature
review it develops a methodology for a rough estimation of the cost-efficiency of measures
intended to reduce nutrient immissions into the Odra river basin and the Odra Estuary. The results
are presented as annual marginal costs and absolute costs of the respective measures. Agricultural
measures prove to be the most efficient means to reduce nutrient immission – but only up to certain
threshold levels and following uneven regional patterns. To realise radical cuts in nutrient
immissions, a combined strategy integrating agricultural and waste water treatment oriented
measures would be necessary.
The preliminary results presented in this paper suggest threshold levels for reductions of nitrogen
immissions into the Odra river at around 2500 t per year from point sources and around 3000 to
5000 t nitrogen immissions from diffuse sources. Annual reduction costs at these levels would be
38 million € for waste water treatment and between 30 and 60 million € for agricultural measures.
Concerning phosphorus, a reduction up to 450 t by improvement of treatment technologies appear
to be feasible at annual costs of approximately 7 million €. The work on this task will be finished
in spring 2010 with including more measures and cost functions into the MONERIS model system.