The number of wastewater treatment plants (WWTPs) in the Czech Republic is increasing. Wastewater, which was previously disposed of in other ways (e.g. septic tanks, cesspits etc), is now entering the surface water (after treatment at a WWTP). Billions of Czech crowns have been invested in the construction of new WWTPs or reconstruction and intensification of existing ones. This money had been invested to meet discharge standards for individual pollutants. However, the overall level of pollution associated with wastewater discharges has not been assessed. The indicator of grey water footprint was used to assess whether there was an increase in pollution load discharged from WWTPs between 2002 and 2018. Discharged pollution data from 4115 industrial and municipal WWTPs were analysed. The analysis of such a large data set has not been carried out yet and brings new knowledge concerning the effect of WWTP size on the grey water footprint. Overall, the total value of the grey water footprint (and thus of the discharged pollution level) decreased in the monitored period. Grey water footprint caused by the largest WWTPs decreased, while the grey water footprint of small WWTPs increased, due to the increase in their number. The decisive pollutants that determine the value of the grey water footprint are total phosphorus and ammonium nitrogen. Measures targeting these two main pollutants can significantly reduce the overall level of pollution load discharged from WWTPs.

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This study compares the Life Cycle Assessment based Water Scarcity Footprint of produced energy unit in two nuclear power plants in the Czech Republic between 2005 and 2015. Primary data has been used to allocate impacts to the core processing stage. Although the real total amount of water consumption in both power plants is similar, the water scarcity footprint in Temelín nuclear power plant is of approximately 8.9 m3 H2Oeq per MWh lower than in Dukovany power plant. The cooling water has the most significant contribution to the freshwater availability impact category. Evaporation from reservoirs which are a part of water management of the individual power plants has lower, but not inconsiderable, contribution to the water consumption. In the case of Temelín nuclear power plant, the loss caused by evaporation from Hněvkovice reservoir is of approximately 6.5% of the difference between withdrawal and discharge of the power plant. In the case of Dukovany nuclear power plant, evaporation from Dalešice - Mohelno reservoir is of even around 11%.

Water accounting is an important tool for water managers. Many studies use official water accounting data or similar data for their assessment. In particular, large-scale studies or water footprint studies have limited opportunities for “in-situ” data collection. In many cases, the processors of studies do not know the origin of the data and their limitations. Water accounting data are very often used for decision-making process, water resource management, and planning in the water sector. This article tries to answer the question “How truthful are water accounting data?” For this task water accounting in the agriculture sector in the Czech Republic was selected. The data on water withdrawals for the agriculture purposes was analysed and compared with water needs estimation based on additional data on agricultural production.

Surface water pollution is referred to be a problem in the entire Odra river basin. In sub-basins, an insufficient degree of wastewater treatment has been identified as a major problem – in relation to the best available technologies and environmental objectives of Directive 2000/60/EC. The grey water footprint indicator was used to express the influence of point sources of pollution (industrial and municipal wastewater treatment plants) on discharged pollution reduction in the Czech part of the international Odra river basin. The number of 391 records of wastewater treatment plants for the period 2004–2018 was analysed. The results show that the wastewater treatment plants reduce by up to 92% the potential water needs for dilution of pollution discharged into waters in the Czech part of the Odra river basin.