Freshwater - Drivers and pressures (Czech Republic)
Changes in industry, public sector and wastewater treatment are the main positive drivers and pressures influencing water quality.
The construction and modernisation of wastewater treatment plants (WWTPs) and sewerage systems has contributed significantly to reducing the pollution discharged into watercourses from point sources, particularly since the mid-1990s. The proportion of the population connected to public sewerage systems has increased from 72 % in 1990 to 81.1 % in 2008 (see Fig.). Between 1990 and 2008, the proportion of wastewater (excluding rainwater) treated and discharged into sewerage systems increased from 75 % to 95 % (see Fig.). Moreover, the percentage of tertiary treatment to remove problematic nutrients in new and modernised WWTPs has increased (see Fig.). Since 1990, the total number of WWTPs in the Czech Republic has more than tripled. The first new sewerage systems and WWTPs were constructed in larger towns and cities. This is because coverage in smaller municipalities, where the population density is lower, requires a larger financial outlay and the construction itself takes longer. More information: http://issar.cenia.cz/issar/page.php?id=1776.
The positive developments in wastewater treatment are supported by the obligations under Council Directive 91/271/EEC concerning urban wastewater treatment. The decrease in phosphorus emissions has also been supported by a ban on phosphates in detergents since October 2006 (see Fig.).
The presence of nutrients in freshwater can also be attributed to agriculture. After 1990, the use of inorganic fertilisers decreased significantly in connection with the transformation of agriculture and an increase in the cost of fertilisers. From 1993, the use of inorganic nitrogen fertilisers started to increase, mainly to compensate for the decrease in applied nitrogen from livestock manure production. From 2000, the balance in inputs minus outputs increased to 60–73 kg N per hectare, which is reasonable given the climatic conditions in the Czech Republic. However, the use of nitrogen in organic fertilisation is a very one sided affair causing many problems. Nitrogen run-off into water from agriculture is influenced by erosion, soil compaction, inappropriate agricultural techniques and the storage of fertilisers and livestock manure. The average amount of nitrogen run-off from agriculture on Czech territory is approximately two-thirds of the balance (see Fig. (for soil surface nitrogen balance) and Fig. (for soil surface phosphorus balance)).