A prerequisite for achieving high energy efficiency of water supply systems (understood as using less energy to perform the same task) is the appropriate selection of all elements and their rational use. Energy consumption in water supply systems (WSS) is closely connected with water demand. Especially in the case of oversized water supply systems for which consumers’ water demand is at least 50% less than previously planned and flow velocity in some parts of the system is below 0.01 m·s⁻¹, this problem of excessive energy consumption can be observed. In the literature, it is difficult to find descriptions and methods of energy management for such a case. The purpose of this study was both an evaluation of the current demand of an oversized WSS and a preliminary technical analysis of the possibility for energy saving. Solutions are presented that resulted in improvements in energy management, thus increasing energy efficiency. The conducted analyses indicate the wide use of numerical, hydraulic models, among others, for the needs of the sustainable oversize water supply systems management in order to improve energy efficiency. Those simulations only give energy consumption results as a first step in the process of decision-making for the modernization process, in which investment costs should be taken into account as a second step. Thus, this paper emphasizes the crucial role of hydraulic models as a good analytical tool used in decision support systems (DSS), especially for large, oversized water supply systems.

The article is focused on the issue of blackouts in a water industry and the selection of a renewable energy source for a water treatment plant. In the case of power outage, it is necessary to constantly ensure the supply of a drinking water, if this requirement would not be met, it could cause of deterioration of hygiene and health of the population. To be able to convey drinking water during a blackout, it is mandatory to have a backup power supply. The state of the current water treatment plants in the Czech Republic is that they are using diesel generators as backup power supply, which causes air pollution. There are other options of power supply that can be used, such as renewable energy sources. By using a multi-criteria analysis method, renewable energy sources were analyzed for a water treatment plant in the selected region. Based on the results, it seems that the most suitable choice is a small hydro power plant at the entry points of water treatment plant. Other possibilities of renewable energy sources that may be suitable for a water treatment plant and the usage of a multi-criteria analysis method for a water treatment plant in other countries are also discussed.

The issue discussed in this article concerns corporate social responsibility (CSR), which is playing an increasingly important role in the context of sustainable development of enterprises. The purpose of the current work was to assess the practices applied in the area of corporate social responsibility in water and sanitation companies, based on the opinions of employees and managers. The motivation for undertaking research on this topic resulted from the scarcity of scientific studies on the measurement of the corporate social responsibility concept in water and sanitization companies using a multidimensional approach based on the ISO 26000 standard. The study used methodological triangulation based on the use of qualitative and quantitative research methods to verify information from different sources. This approach allowed the authors to obtain the data more effectively and analyze the problem from numerous different perspectives. The study used an interview method that targeted water and sanitization utility staff. In-depth research was based on the case study method, which is particularly important when researching complex phenomena. For this purpose, surveys were carried out, the results of which indicate that corporate social responsibility of the surveyed enterprise is at a high level, and that there are statistically significant differences between individual dimensions of CSR. The results indicate that the surveyed company is oriented towards supporting activities in the area of corporate social responsibility, in accordance with the in the concept of sustainable development.

The main rule included in IPPC directive (Directive 96/61/EC) obligating installation owners to operate in the sustainable way in order to reduce the impact on the environment. Water resources are limited, therefore many industries, in particular in water-stressed areas, must invest in water-saving programs. In particular, this problem applies to paper plants, which should limit their consumption of fresh water. However, the main environmental consequence in the production of pulp and paper refers not only to the consumption of water resources, but also to the emission of wastewater resulting from the production process. This paper focuses on the concept of sustainable management of water and wastewater. The proposed approach is demonstrated with a case study. The different treatment facilities option has been tested to find the optimal solution to minimalize consumption of fresh water and reduce effluent loads. The optimal water-wastewater configuration was found by testing several configurations. We concluded that striving for a nearly full circulation loop closure is not always justified by sustainable development and should be assessed in an integrated way.

Water management in cities is a critical factor for sustainable growth and development. Satisfying the current needs with respect for the future is not possible without properly managed water and wastewater systems. An essential element of wastewater systems is the wastewater treatment plant (WWTP). The nexus between wastewater treatments and energy demand is a well-known problem. In times of energy crisis, effective energy management in this critical infrastructure is a key task. The purpose of this article is to analyze WWTPs’ energy consumption with regard to proposed management strategies for managers, designers and decision makers. A detailed analysis of WWTP operational parameters and a proposal of improvement actions will be useful for applicability and benchmarking studies. Estimating the carbon footprint (CF) of selected WWTPs considering the indirect emissions due to energy consumption is an important step for developing energy neutrality of WWTPs. Due to the desire to deepen research in the area of a complex phenomenon, which is the energy management system in WWTPs, the research undertaken herein is based on the case study method of three water and sewage companies operating southwestern Poland. Each urban area has different specificities, natural conditions and needs. The presented results of the analyses may be the basis for developing directions for changes in national policy, other benchmarking studies, and improving the energy management system in WWTPs.