One of the tasks of the socio-economic evaluation is the quantification of the damage costs of the current pollution of the Scheldt district.
We consider three main pressures (three sectors: households, agriculture and industry) in the Scheldt district. Damages that have to be evaluated are the damages to the water environment and the damage to those who use the water environment (net economic losses for fisheries, shell-fisheries and commercial aquaculture; reduction in recreational and tourist activities; health effects to humans, livestock; negative ecological effects on biota; loss of value for waterside residential properties, loss of amenity value of water bodies, etc).
Damage costs have to be evaluated at different levels (local, regional, global) and for all aquatic ecosystems.

In order to mitigate these damages, a program of polluting control measures will be set up. Measures will be selected according to the pressures that exist in the Scheldt district. This program of measures has to be as cost-effective as possible; therefore a cost-effectiveness analysis should be performed to choose the most cost-efficient polluting control measures.

Thirdly, a cost-benefit analysis will be carried out, this one compares the total (direct and indirect) benefits and costs of the program of measures. Benefits are the damage costs avoided and the costs refer to polluting control costs. Therefore, the aim of this step is to compare the two preceding steps i.e. damage costs and polluting control costs taking into account all indirect effects.

In a very general and synthetic way, we can say that there are two main “types” of costs to determine. On the one hand, we have the cost of the pollution or damage costs of the Scheldt district (the damage to the environment and the damage to those who use the water environment) and on the other hand, we have the costs of the measures selected to mitigate the pollution (pollution control costs).