The costs incurred by water boards to maintain and improve the quality of the surface water are paid for from the revenues of the anti-pollution levy. This tax is levied to private households and companies on the principle of ‘the polluter pays’.
Pollution in a water board catchment area is expressed in pollution units. These are assigned to polluters in accordance with the amount they pollute. Households, for example, are charged for a standard three units. Single households for one pollution unit.
Companies with high pollution levels are charged more than those who have lower levels. The level of pollution is measured in the effluent, or on the basis of the amount of water intake.