WASTE WATER TREATMENT

Last update
12.09.2012

Key question

How much of the Czech Republic’s population is connected to sewerage systems and waste water treatment plants and what is the proportion of treated waste water?

Key message

In the long-term perspective, there is a constant improvement of sewerage and waste water treatment infrastructure. Since 2000, the length of the sewerage network has doubled, the number of inhabitants connected to public sewer has increased (from 75% to 83%), particularly the proportion of inhabitants connected to sewers that ends in a waste water treatment plant (from 64% to 78%). The share of treated waste water has increased slightly (from 95% to 97%), the number of waste water treatment plants (WWTPs) has almost doubled and, last but not least, the proportion of tertiary treatment has grown slightly (from 43 % in 2002 to 46% in 2011).

So far, the requirements for urban waste water treatment in agglomerations above 2,000 population equivalent provided for by the Council Directive 91/271/EEC have not been met, and the unsatisfactory state in ensuring the collection and treatment of waste water concerns 43 agglomerations out of 633 (the total number).

Overall assessment	Change since 1990	Change since 2000	Last year-to-year change

The treatment and discharge of municipal waste water and some waste water originating in the food processing industry is dealt with by the Council Directive 91/271/EEC of 21st May 1991 concerning municipal waste water treatment. The Directive aims at protecting the environment from the adverse effects of waste water discharge. In particular, it is necessary to ensure secondary treatment of municipal waste water in sensitive areas according to the Nitrate Directive, namely construction of the missing water management infrastructure (in particular waste water treatment plants and sewers), reconstruction and improvement of the waste water treatment technology in all agglomerations over 2,000 population equivalent. The Czech Republic was supposed to finish this within the transition period, i.e. by the end of 2010.

The mid-term strategy of state policy concerning water supply and sewerage systems prior to 2015 is presented in the Development Plan for Water Supply and Sewerage Systems of the Czech Republic that is linked to other strategic documents, while respecting the requirements of relevant EU legislation. Furthermore, the desirable trend includes increasing the proportion of the population connected to public sewerage systems and increasing the proportion of the population connected to sewers ending in WWTPs. For the Development Plans for Water Supply and Sewerage Systems of the Czech Republic’s Regions, the number of opinions that are issued by the Ministry of Agriculture on proposed changes to the technical solutions to drinking water supply, sewerage services and waste water treatment increases every year.

Chart 2: Waste water treatment plants according to treatment stages, the Czech Republic [number]
Source: The Czech Statistical Office

Chart 3: Volume of wastewater discharged into municipal sewerage systems and their treatment, the Czech Republic [mil. m³]
Source: The Czech Statistical Office

Chart 4: The proportion of the population connected to waste water treatment plants according to treatment stages, an international comparison, 2007 [%]
Source: Eurostat

Indicator assessment – text part

Since 2000, and especially in the period after the Czech Republic´s joining the EU in 2004, the network of sewers and WWTPs had gone through significant development. In 2011, the sewerage networks were twice as long compared to the year 2000 and the proportion of the Czech Republic´s population connected to the sewerage increased from 74.8% to 82.6%. The trend of increasing the share of the population connected to the sewerage system is not so significant in recent years since both sewers and waste water treatment plants have been constructed to a great extent in larger towns and cities and it is necessary to gradually cover smaller municipalities where fewer inhabitants are concentrated. Nonetheless, the 14% increase in the share of the population connected to sewerage ending in a WWTP between 2000 and 2011 is very positive. So far, not all the waste water discharged into sewerage systems is treated, however, the proportion of treated waste water (96.8%) is very satisfactory. Over the monitored period since 2000, the proportion of waste water that is discharged into sewerage systems and treated has stagnated at 94–96%. According to data from the Czech Statistical Office, 96.8% of the 487.6 mil. m3 of waste water discharged into sewerage systems, excluding rainwater, was treated in 2011 (in 1990 the proportion was only 75%). In 2011, 95.9% of sewage discharged into public sewers and 98.7% of industrial and other waters were treated. The amount of treated rainwater is generally growing, with year-to-year fluctuations being influenced by precipitation totals in the years concerned.

In comparison with the year 2000, the total number of WWTPs for public use has doubled to 2,251 in the Czech Republic; their total capacity decreased slightly (by 3.3%) because of reconstructions of older plants but the volume of waste water discharged into sewers has decreased, too. The significant increase in the number of WWTPs after 2004 is related to implementation of the Council Directive 91/271/EEC which requires securing treatment of municipal waste water and waste water from certain industrial sectors (food industry). Due to the construction and modernization of waste water treatment plants, the number of WWTPs with nitrogen or phosphorus removal (tertiary treatment) increased by 55, the number of those with basic mechanical-biological treatment by 7 and there is one new plant with mechanical treatment. All agglomerations with population equivalent over 10,000 have ensured tertiary treatment, although not all of them comply with the Directive´s requirements for the quality limits concerning discharged waste water.

In 2011, altogether 52 WWTPs with capacity exceeding 2,000 population equivalent were reconstructed or expanded and three new ones were put into operation. At the end of 2010, the transitional period to meet the requirements of Council Directive 91/271/EEC ended, but even on 31st December, 2011, 43 out of the total number of 633 agglomerations with population equivalent over 2,000 had not ensured waste water collection and treatment in a satisfactory manner. Of this number, 35 agglomerations have not complied with the treatment limits (of which 15 agglomerations do not have any wastewater treatment plant at all), 6 agglomerations are connected to a WWTP in another agglomeration with an unsatisfactory WWTP and two agglomerations are building a connection to a satisfactory WWTP in another agglomeration. Improvement of the state and gradual meeting of the requirements in the following years can be expected.

The average efficiency of wastewater treatment plants (the amount of pollution degraded and removed) is very high in the Czech Republic; in 2011, it was as follows: 97.9% for BOD5, 97.5% for suspended solids, 94.3% for CODCr, 82.4% for Ptotal and 72.5% for nitrogen substances. The values are similar to those in previous years, which is connected with the fact that the modernization of large waste water treatment plants is complete and the amount of pollution produced in individual agglomerations has stabilized.

In an international comparison, there is a generally better situation in the countries of northern, western and partly also southern Europe as far as the population´s connection to WWTPs and treatment stages are concerned. The states of Eastern Europe and the Balkans lag behind the EU average. The Czech Republic holds the leading positions among the new EU member states in the share of the population connected to sewer with a waste water treatment plant and in the proportion of tertiary treatment. In these terms, the worst situation is in Romania and Bulgaria (EU members since 2007), which began to build sewerage infrastructure intensively with regard to implementation of the EU legislation in the last few years. Existence of great regional differences in these indicators between the cities and rural regions is also typical for these countries.

Data sources

The Czech Statistical Office
The T. G. Masaryk Water Research Institute (a public research institution)
The European Environment Agency (EEA)
Eurostat, The Statistical Office of the European Union

Links to additional information

The European Environment Agency, international indicators (CSI 024)
Water Supply, Sewerage and Watercourses, The Czech Statistical Office tables
Report on the state of Water Management in the Czech Republic