PV systems are gaining ground as a standard for family homes. Apartment buildings are lagging behind, but design optimization and community energy bring new possibilities.

The paper discusses solutions to rural sanitation. As population density decreases, the cost of central sanitation rises, and so villages with high sanitation costs risk having sewerage charges above the socially acceptable water price. This is also why other methods of sanitation should be used. In addition, in future, rural solutions should take into account not only the economic aspect but, as with other investments, all aspects of sustainability (see EGS assessment). Following the experience of climate change impacts, experience of natural phenomena and war events, the impact on climate change and the resilience of solutions to risks should also be part of the assessment.

The presented set of four communications deals with the risk management in favour of safety applied to the operation of pipelines. It respects current professional knowledge and presents it in the concept promoted by the UN, the European Union, the OECD and others. The fourth part contains a conclusion, characteristics of new aspects addressed by the professional sphere for practice and a list of used literature.

The presented set of four communications deals with the risk management in favour of safety applied to the operation of pipelines. It respects current professional knowledge and presents it in the concept promoted by the UN, the European Union, the OECD and others. The third part summarizes the findings on the checklist methodology and provides examples for pipelines.

The presented set of four communications deals with the risk management in favour of safety applied to the operation of pipelines. It respects current professional knowledge and presents it in the concept promoted by the UN, the European Union, the OECD and others. The second part summarizes the knowledge and principles of risk management and lists the sources of risks for the pipeline.

The presented set of four communications deals with the risk management in favour of safety applied to the operation of pipelines. It respects current professional knowledge and presents it in the concept promoted by the UN, the European Union, the OECD and others. The first part introduces terms used in engineering practice, which deals with risks and safety and introduces knowledge that is relevant to pipeline safety.

The agricultural holdings built in the 1970s have, from today's perspective, an inadequate wastewater management concept associated with the operation of single sewers. The paper deals with the solution of the conceptual approach presented on a specific agricultural site. Extensive technologies were used for wastewater treatment, represented by a model vertical filter with integrated aeration, which should show adequate results.

This paper deals with the study of the effect of the use of styrene in a polyester resin as a polymer binder in a trenchless rehabilitation composite. The different formulations also contain secondary raw materials as waste foam glass, basalt frit, waste glass from solar panels and fly ash. In the development of the formulations, which are subsequently used to saturate the polymer sleeves, the influence on the mechanical properties of the whole composite is mainly investigated. The mechanical parameters investigated include mainly the flexural modulus, the stress at first failure, the flexural deformation, adhesion of the lining to the pipe. The work found that the decrease in mechanical properties for the non-styrene variant is not so significant as to prevent its effective use in the composite.

An analysis of a central and decentralized solar domestic hot water system for an apartment building shows that the usable solar gain and year-round efficiency are similar, but the solar coverage and the need for backup heat source energy are fundamentally different.

Recently, there have been more and more cases of suspected influence on water levels. There are more and more related disputes with this trend. However, the employees of water authorities have no choice but to rely on the experience of the geologist who prepared the project. In terms of form, the project can be processed well. But fatal problems can arise in terms of well operation. A special chapter is the wells for heat pumps with all their shortcomings and huge technical problems with grouting cement mixtures resulting from small diameters of wells. The aim of this paper is to inform about the wide possibilities of well logging to find out the real cause of the problems related to the level drops and to suggest the optimal way of remediation.

Tracer tests (indicative or indicator tests, use of markers) are a key technique for determining preferential flow paths and delineating watersheds in karst. They are also widely used to verify flow and determine transport characteristics at contaminated sites. They consist of injecting a known amount of tracer into a sinkhole or well and taking water samples at the locations where tracer is expected to reappear. Tracer tests make it possible to determine not only the flow velocity, but also the volume of mobile water between objects when discharge is measured, and also how many % of the tracer has arrived at the monitored objects, and thus also how many % of the tracer, on the other hand, is heading to unmonitored/unknown places. In the Czech Republic, tracer tests were so far usually carried out mainly with NaCl, especially in connection with water supply facilities. In the USA and neighboring European countries, the most commonly used tracer for decades has been the sodium salt of fluorescein (hereinafter Na-fluorescein) and other fluorescent tracers, as their background concentrations in nature are mostly zero and modern fluorimeters enable to detect tracer concentrations usually in tenths of μg/l, which allows the injection of a very small amount of tracer compared to NaCl, well below visibility with the naked eye. Na-fluorescein is conservative, well soluble, non-toxic. Analysis consists of either direct measurement of fluorescence with field fluorimeters or sampling and laboratory analysis on a laboratory fluorimeter. A tracer test with Na-fluorescein in 2021 demonstrated the rapid flow of water from the Bubovický stream sink in the Český Kras to the springs in Sv. Jan pod Skalou and the surrounding area, and on the contrary refuted the possibility that the water from the sink is connected with the water supply well in Srbsko. The tracer test with Na-fluorescein carried out in 2022 in the Chýnov cave aimed to more accurately characterize the connection of the underground flow with the spring Rutice – drinking water supply for Chýnov town. A positive statement was obtained from the regional public health authorities to carry out the above-mentioned tracer tests. Tracer tests with Na-fluorescein can now be used in the Czech Republic in the same way as in neighboring countries. In conclusion, it can be stated that tracer tests are an effective tool for monitoring groundwater flow not only in karst environments. They can be used to confirm or disprove the rapid connection of sinks, streams, and other objects with drinking water supplies, thereby targeting measures to prevent the possible contamination.

The global pandemic that has swept the world in the last two years has affected most of the population. However, the pandemic has also had an indirect effect on water resources in the water sector. One such example is the almost borderline depletion of groundwater reserves at the Koberovy site, Jablonec nad Nisou district.
The area of interest is interesting from a geological and hydrogeological point of view only because it is located on the border of the Podkrkonoše and Bohemian Cretaceous basins. It is an area with a small catchment area, lower rainfall and also higher groundwater abstractions, i.e. an ideal location for the problem that came at the turn of 2020 and 2021.
In the Koberovy community, groundwater withdrawals from the water supply pumping facility, the drilled well KH-3, increased threefold over the area‘s groundwater table during this period. This has created a significant problem affecting groundwater management in the area. Thanks to the established system of express pumping tests at the intake facilities managed by Severočeské vodovody a kanalizací, a.s. (referred to as SčVK) and field investigations at the site, causes have been identified and solutions proposed that are not ideal from the point of view of the water supply hydrogeologist. As a result, the hydrogeologist recommended adjusting the pumping regime, which was to „buy time“ until the necessary change in the concept of supplying, the area of interest, with drinking water.

Tritium (³H), radioactive hydrogen, which occurs on the Earth's surface in low concentrations, can be used as a tracer due to its suitable properties. For this purpose, tritium was monitored in groundwater and precipitation samples. The tritium concentration in groundwater was lower than in precipitation. This is caused by the radioactive decay of tritium, infiltrated from the surface into groundwater, where the connection with the surface is limited. Tritium concentration can therefore be used to infer the rate of connection between groundwater and the surface and can be used to estimate the level of infiltration or the vulnerability of groundwater.

In the Brno area there are abundant groundwater sources in artesian structures. The hydrogeological aquifer of artesian water are Miocene sands covered with the position of Baden's calcareous clays. Under the Brno there is therefore a usable hydrogeological structure, able to serve as an alternative source of water to bridge emergencies and crisis situations. The expected usable reserves of artesian water are 200 to 300 l.s⁻¹. The yield of the structure may be threatened by excessive water extraction, as artesian waters have been (and in some cases still are) used mainly as a source of water for industrial enterprises. In 2021, the first stage of hydrogeological work took place, the aim of which was to revise selected existing hydrogeological wells, which could be used as potential sources of drinking water to ensure the required volumes of water for the needs of emergency water supply of Brno city. In 2022, the second stage of work took place, the aim of which was to define land suitable for excavating new wells.

Design engineering using standard objects brings new possibilities to water management design practice. Similar to CAD tools in the past, integrated engineering now represents the gateway to the world of digitization of water management units and can be understood as an effective pre-step before the introduction of BIM, enabling the creation of digital twins and operational optimization. These new procedures can open the gates of perception of the project and management of the whole in hitherto unknown levels. Due to emerging legislative and business trends in the Czech Republic, we can expect an increased demand for digitally processed projects in object architecture, enabling an interconnected approach to the creation and management of documentation in individual phases of the life cycle of a technological unit.

The article shows the ways of using load profiles of hot water heaters defined by Commission Regulations No 811, 812, 813 and 814/2013 to construct a cumulative hot water consumption curves. The authors point out errors commonly made by designers of hot water preparation systems in relation to the use of the load profiles. The conclusion of the article contains a comparison between consumption curves obtained with use of the hot water heaters’ load profiles and real measurements in different types of buildings.

The paper deals with the methods of checking the performed sealing works in its second part. Measurements of the permeability of the grouted environment in the field are evaluated, the findings of the grouting records are analyzed and the cement content in the taken samples of the grouted soil was determined in laboratory conditions. Finally, the recommendations for remediation are summarized.