Waste water from households and businesses, as well as losses of nutrients and pesticides from agriculture and other sources, damage the quality of the surface water. This damage is expressed amongst other things in the negative oxygen conditions, excessively high nutrient concentrations and the presence of all kinds of harmful substances in the aquatic environment. This all leads to a general decrease of the ecological quality.
Physical disturbance, such as making infiltration areas impermeable, straightening watercourses, nature unfriendly embankments and dampening of ditch systems not only damage the environment of aquatic organisms, they also result in a reduction of the self-purification processes that allow the surface water to process some of the pollution itself.
The government is trying to improve the water quality through the development and improvement of the public waste water treatment infrastructure, by improving the structural characteristics and by cleaning watercourse sediments. Via permits, levies and inspections the governmentencourages business to decrease pollutants loads. In the Manure decree the government wants to reduce diffuse losses of nitrogen and phosphorous through agriculture.