Uranium concentrations in groundwater taken from private drilled wells have been never determined in Poland, implying a lack of available data to quantify the human exposure to U through drinking water consumption, especially in rural areas influenced by mining activities. The main aim of the study was the assessment of human health risk related to the consumption of well waters containing U, collected from selected rural areas of the Lower Silesian region (Poland). The random daytime (RDT) sampling method was applied to the collection of well waters from three control study areas (CSA): Mniszków (CSA-A), Stara Kamienica/M. Kamienica/Kopaniec (CSA-B) and Kletno (CSA-C). The analyses of RDT samples were performed by validated method based on inductively coupled plasma mass spectrometry (ICP-MS). Uranium concentration ranges in well waters and the estimated geometric means for individual control study areas were: 0.005-1.03 μg/L and 0.052 μg/L (CSA-A), 0.027-10.6 μg/L and 0.40 μg/L (CSA-B), and 0.006-27.1 μg/L and 0.38 μg/L (CSA-C). The average and individual chronic daily intakes (CDI) of U by drinking water pathway (adults/children) were in the ranges of: 0.0017-0.013/0.0052-0.040 μg · kg-1 · day-1 and 0.0002-0.90/0.0005-2.71 μg · kg-1 · day-1. The average %TDI and ranges of individual %TDI (adults/children) were: 0.17%/0.52% and 0.02-3.4%/0.05-10.3% (CSA-A), 1.3%/4.0% and 0.09-35%/0.27-106% (CSA-B), and 1.3%/3.8% and 0.02-90%/0.06-271% (CSA-C). The estimated average CDI values of U through well water are significantly lower than the TDI (1 μg · kg-1 · day-1), while for individual CDI values the contribution to the TDI can reach even 90% (adults) and 271% (children), indicating essential human health risk for children consuming well water from private drilled wells located in CSA-B and CSA-C (5.3% of total number of samples collected).

People rarely consider where their tap water comes from, or how much of it is actually available. At the same time, it is people who are most often responsible for water pollution. Problems involving the contamination of water-supply areas in Poland are scrutinized by an “intervention team” of experts at the Polish Hydrogeological Survey.

Potok Golawiecki (a river in the province of Silesia) is polluted in a way typical for the Upper Silesian industrial zone. It is the river into which the Ziemowit coal mine discharges its salt waters and it also receives municipal sewage. Changes in the values of selected indicators ofwater quality for Potok Golawiecki along its course were determined in the paper. It was found that the hydrochcmical character of the water in Potok Goławiecki depended strongly on salt water discharges from mines, which were the main factor disturbing the river's natural environment. The pollution of the river makes its water non-potable, and excludes its use even in industry

Forecasts suggest that the freshwater resources available to our civilization will shrink by 30% in the coming two decades. How can we reverse the degradation of water resources and create a balance between the society’s demand for water and the capacity of the hydrosphere?

The paper presents a small water reservoir Psurów located on the Prosna River (right tributary of the Warta River) in the Opolskie Voivodeship (southern Poland). Results of water quality analyses of the Prosna River flowing into the reservoir and the outflowing water, as well as water stored in the reservoir have been discussed. Water flows of the Prosna River above and below the Psurów reservoir were analyzed. The analyses were carried out from November 2006 to October 2008. The research showed that the small water reservoir Psurów contributed to the reduction of the following loads: phosphates (by about 21 %), nitrates (by 26%), nitrites (by 9%), ammonia (by 5%) and total suspended solids (by 17%). It was found out that there was a statistically significant relationship (p < 0.05) between the volume of water flowing out of the reservoir and the inflowing water (Pearson's correlation coefficient: r = 0.93). Based on the Yollenweider's criterion the Psurów reservoir was classified to polytrophic reservoirs.

CropSyst model can be used as irrigation water management tool to increase wheat productivity with poor quality water. The objective of this study was to calibrate CropSyst model for wheat irrigated with fresh and agricultural drainage water. To do so, three field experiments were conducted during three successive seasons in Nubaria Agricultural Research Station, Egypt representing the newly reclaimed calcareous soils. In the first season the treatments were 100% crop evapotranspiration (ETc) of fresh water (FW) and 100% ETc of agricultural drainage water (DW), while in the second and the third seasons, the treatments were 100% ETc of FW, 100% ETc of DW, 120% ETc of DW and 130% ETc of DW. From these results one can concluded that deducting 5% of the applied water to all treatments reduced yield by 3, 5 and 7% in the first, second and third growing season, respectively as a result of heat stress existed in the 2nd and 3rd seasons during reproductive phase. Furthermore, deducting 5% of the applied water from all treatments in the vegetative phase only resulted in lower yield losses. Thus, using CropSyst model could guide us to when we could reduce the applied irrigation water to wheat to avoid high yield losses.

The Netherlands has a long tradition in water management, mainly stemming from the geography of the country. The ‘struggle with water’ has been organised from medieval times by the water boards (waterschappen), which are the oldest democratic institutions in the Netherlands. Nowa-days the water boards, 27 in the whole of the Netherlands, are not only responsible for flood protec-tion and regulation of water levels, but for water quality management and waste water treatment as well. In the years in which the WFD implementation has been underway in the Netherlands, several issues have arisen. Cooperation between all levels of government is key. This requires as clear as possible divisions of competences between the various parties involved. It also takes much time, es-pecially in a process in which many matters have to be invented ‘on the fly’, such as criteria for des-ignating water bodies, ecological standards, and the formulation of MEP and GEP.

Polish water resources depend on precipitations, which are variable in time and space. In dry years the water balance is negative in central parts of Poland but sudden thaws and downfalls may result in periodical water excess and dangerous floods almost in the entire country. The retention capacity of artificial reservoirs in Poland permits to store only 6% of the average annual runoff, which is commonly considered insufficient. Another method to increase retention is soil water con-trol. About fifty percent of soils in Poland consist of light and very light sandy soils with low water capacity. Loams and organogenic soils cover approximately 25% and 8.5% area of the country, re-spectively. Almost half of agricultural lands (48%) have relatively good water conditions, but the rest requires soil water control measures. An increase of the soil water content could be achieved by changes of soil properties, water table control and soil water management. Modernization and recon-struction of drainage and irrigation systems, which were built mainly in the period 1960–1980, is needed.

The research was set up in the Neretva River valley in the Southern part of Croatian Karst area, where implementation of modern hydrotechnical practices within the river catchment’s area led to intrusion of seawater to groundwater resulting in soil salinization in the delta. The region has great agro-ecological potential for intensive production of vegetables and Mediterranean fruits. Since the combination of the effects of saline groundwater and the use of this water for irrigation may have disastrous effects on the productivity of agricultural soils water, a project was started in order to set up a permanent monitoring network. The aim of this study was to determine the salt dynamics in the surface water on five locations which are considered as potential sources of the irrigation water (Modric canal, Neretva River near Opuzen, Crepina, Jasenska and Vidrice pumping station) during a 4-year period (1999–2002). The surface water samples had been collected on monthly basis and analyzed for all parameters required in the irrigation water quality classification. The results show considerable spatial and temporal variability of determined parameters. Thus, in the Neretva River near Opuzen, total salt concentrations in water ranged from 0.4 to 7.7 dS·m–1, and in Modric from 1.65 up to17.2 dS·m–1. Dominant cations and anions on all observed locations were Na+ and Cl–. Constantly high concentration of Na+ in sampled surface waters is of a special concern. Utilization of the water of such quality may cause problems related to the use of alkaline waters for irrigation, which can further cause permanent loss of fertile soil.

The study covered water resources of two mountain streams in the Polish Carpathians. These were the Biała Woda and Czarna Woda streams, the catchments of which are adjacent to each other. Water flows in both streams were measured during the hydrological years from 2006 to 2020. Next, water outflows from the catchments were calculated. The study aimed to determine differences in the water resources of those catchments in a very small mountainous area. The study showed quantitative similarity in water resources in the entire multi-annual period but at the same time large differences in shorter periods. Instantaneous and daily outflows showed the largest differences, but differences in annual outflows of up to 20% were also recorded. Therefore, hydrological data from operational cross-sections to assess water resources of neighbouring uncontrolled watercourses should cover multi-annual mean values. It was found that during periods of increased runoff (from melting snow or precipitation), the outflow from the Biała Woda catchment was much larger, while during rain-free periods, the outflow from the Czarna Woda catchment prevailed. All short- term flood like outflows were at least several tens of per cent higher in the Biała Woda catchment. The higher retention capacity of the Czarna Woda catchment can be attributed to the land use (mainly forest areas). The results can be used for modelling catchments of similar parameters and determining their retention capacity.

The paper presents the result of hydrogeological studies of Lublin Coal Basin (LCB), particularly at Jurassic level. It is arranged in several parts: I) stratigraphy, tectonics and lithology of Jurassic system at LCB territory, 2) groundwater dynamics, 3) chemical composition of waters, 4) hyclrogeochemical stability conditions. The paper also suggests a few main directions of using the Jurassic waters in prophylaxis and therapy of many diseases. The waters, containing considerably elevated quantities of fluorine compounds come from Jurassic formation lying at the considerable depth. Coal mine joins them with saline Carboniferous waters. After pretreatment, they are discharged to the surface ancl to the river. Jurassic waters belong to the group of low mineralised waters. They contain 6-1 I mg F/dm3 fluorides. Thus they can be usefu I in prophylactics of teeth ancl paradental illnesses, particularly in risk groups. Thanks to, fluorides contained in these waters they can be used during and after treatment and to support surgical operations or rehabilitation effects.

The results of investigations into suspended matter sedimentation from mine waters in the settling tank at the Ziemowit coal mine as well as in the relevant model of the settling tank were presented. It was shown that variations in the performance of the tank are caused by improperly accumulated sediment, which generates privileged water flow in superficial layers. Additionally, impetuous periodical water discharges seem to be important. The investigations performed on the settling tank model were focused on estimating the influence of temperature, flow rate and the aeration of mine water on the suspended matter sedimentation. Reasons for inefficiency of the settling tank were determined, and technological changes enhancing the process of suspensions removal were suggested.

The Baltic is a unique brakish sea. Its moderate salinity is the result of the fresh river water input and non-periodic inflows of salty, oxygenated waters from the North Sea. However, the balance continually fluctuates. What impact does that have on the sea?

Cyanobacterials (Cyanophyta) belong to phytoplancton. In normal stale concentration of cyanobacterial cells in water rangs between a few hundreds to a few thousands in I drn' of water but while blooming may be increased even to one million in I dm3. At this time water has characteristic color, depending on dominated species. Also characteristic smell is the results of the presence ofcyanobacterial and phytoplankton cells producing odour substances. The cyanobacterial blooms are very important hygienic problem for both human and animal health. While blooming they form foams and head coating on water surface. Also cyanobacterial toxins are huge problem. Cyanobacteria may produce acute toxins such as hepatotoxic peptides (microcystins, nodularins and cylindrospermopsin) and neurotoxic alkaloids (anatoxin-a, anatoxin-a(s), homoanatoxin and aphanotoxins). Cyanobacterial toxins are very dangerous substances which can intoxicate hepatocytes and the nervous system in humans and animals. In this situation it is very important to remove them effectively in water pretreatment processes. In the present paper have been presented for the first time in Poland data on removing cyanobacterial toxins from water in pretreatment process with application of chlorine dioxide and ozone on the example of Sulejów - Łódź water pipe system. In period I 998-200 I the effectiveness rnicrocystin-LR removal ranged between 74--92% while for other izoforms they were between 45-94%.

Permanent grasslands – according to the Water Framework Directive – are typical water related ecosystems so they largely affect water quality, its cycling and balance and therefore deserve protection. They are an element of landscape structure (ecosystem function or service) commonly considered a factor stabilising environmental changes.

Most threats posed to waters in Poland originate from present cropland structure with its definite predominance of arable lands over grasslands. Agriculture should therefore focus on the improvement of land use structure in order to minimise environmental hazards and to guarantee at the same time optimum economic effects. This could be achieved by turning arable lands into grasslands (where justified e.g. on light soils) or at least by maintaining present grassland area (condition in negotiations with the EU) and management that would consider environmental protection.

Increasing the contribution of grasslands to cropland structure or at least maintaining their pre-sent status quo would help to achieve compromise between the goals of farmers and environmental protection. Purposeful utilisation of ecosystem services, particularly those of grasslands, allows to maintain more intensive farming without environmental hazard. Limited should be only such activi-ties whose intensity exceeds regenerative or buffering environmental capacity e.g. on grounds par-ticularly subjected to water pollution or those included into Natura 2000 network.

During the past several years big changes have been observed in waste water disposal, noticeable particularly in the improvement of water protection and sewage treatment. An important element of waste water disposal still requiring improvement is a low development of sewage systems in rural and urban areas. The main problem is an increasing amount of sludge, high degree of sediment hydration and considerable ability to anaerobic decomposition, a lack of areas for managing sediments near big cities and deposits of sediments on storage areas. Selected issues of waste water disposal and sludge handling in the Mazovian Province against a background of waste water disposal and sludge handling in Poland were presented in the article.

Views on the objectives and role of water management have remarkably changed in the last years. The need of a complex water management that would consider all water users including agriculture and natural environment is often underlined. It is pointed out that agriculture and natural environment (including commercial forests) are basic consumers of precipitation water which is not considered in water and economic balances. More and more importance is attributed to the utilisation of waters from catchment basin and to application of non-technical measures of controlling water cycles. A large impact of agro-ecosystems and natural or semi-natural (forests, wetlands) ecosystems on water balance is underlined. This different approach to the problems of water management is expressed e.g. in Water Framework Directive of European Union devoted to surface and ground water protection. The directive attributes a great role to the protection of aquatic and water related ecosystems. More and more often it is realised that the total water resources are equal to the volume of atmospheric precipitation. Water management should involve not only the water in geological aquifers or river channels but also that which is retained in soil profile. Such elements of water balance as spatial distribution, interception, infiltration and recharge of ground water reservoirs, soil retention capacity, surface runoff and evapotranspiration depend largely on land use in a catchment. Through appropriate land use and catchment management, application of rational agro-technical methods, development of small retention, wetland restoration, and hampering water outflow from draining systems one may significantly affect water cycling in a catchment.

Small water resources of Poland, increasing water consumption, climate changes and requirements of environmental protection enforce the implementation of complex methods of water management and search for environmental-friendly methods of limiting economic losses caused by water deficit or excess. Saving water used for economic purposes and agriculture would permit better fulfilment of the needs of natural environment.

The present study aimed to assess groundwater quality according to the water quality index (WQI) in Ali Al- Gharbi district of the Maysan Governorate in eastern Iraq. For this purpose, 10 physical parameters such as pH, total hardness ( TH), magnesium (Mg2+), calcium (Ca2+), potassium (K+), sodium (Na+), sulphate (SO42–), chloride (Cl–), nitrate (NO3–), and total dissolved solids ( TDSs) were examined since 2019 from 16 different locations (viz. wells). The analysis results indicated that 18.75% of the water samples were of good quality, 56.25% of them had low quality, and 25% of such samples were very poor. The WQI also varied from 69.67 and 297.6. Therefore, prior to water use, there is a dire need for some treatments, as protecting this district from pollution is significant.

The possibility of the application of nontraditional method of greenhouse gas utilization by the injection of CO2 (sequestration) into porous geological deposits, treated as unconventional gas collectors, requires the fulfillment of basic criteria such as the impact on the environment and long term storage. The important issue is the physical behavior of the deposit during the porous structure saturation phase by carbon dioxide. What should be mentioned first and foremost is: the availability of CO2 transport along the porous structure and adsorption capacity. The work presents the results of water vapor sorption on coal samples from selected Hard Coal Mines of a differentiated carbon content. The received results were presented in the form of sorption and desorption isotherms performed in a temperature of 303 K. It was additionally described with a BET adsorption isotherm. Based on sorption data, a specific surface area was calculated, in accordance with BET theory. The amount of the adsorbed water vapor molecules for the analyzed coal samples was dependent on the degree of metamorphism. The obtained isotherms can be described as type II according to the BET classification. Volumetric type apparatus -adsorption- microburette liquid was used for the sorption experiments. Water vapor sorption in relation to coals allows for the quantitative determination of primary adsorption centers as a measure of adsorbed molecule interconnections with the adsorbent surface. Based on the BET adsorption equation, out of water vapor isotherms, the amount of adsorption active centers, which potentially may take part in CO2 adsorption in coal seams during injection of this gas, was determined. The sorption capacity of coals is determined by the degree of metamorphism, which also has very large impact on the sorption capacity of the deposit.

Ballast water is a significant vector for the transport and introduction of aquatic organisms, microorganisms and chemical pollutants which impacts on ecosystems worldwide. In the study, ballast water from short- and long- range vessels with treatment systems was microbiologically evaluated in spring (April 20th) and summer (July 19th) and compared with waters of the main Police Seaport in the Odra River Estuary, southern Baltic Sea. All collected samples were evaluated for their physicochemical properties by standard methods. The number of individual groups of microorganisms was determined using the indirect culture method, according to the technique of inoculation of serial dilutions of samples of the examined waters. The results showed differences in the microorganisms in analysed samples. The phylogenetic analysis of bacteria recorded from the ballast water of short-range ships in spring showed the presence of six species of the genus Bordetella, while in summer four species of the genus Clostridium. In the ballast water of long-range ships, proteolytic bacteria pre-dominated in spring and halophilic bacteria in summer. In the summer period, eight species of bacteria were recorded, of which six belonged to the genus Clostridium. The ballast water treatment processes used on ships influence the composition of bacterial communities through selective recolonisation of water, which may transform bacterial functions as an important element of the marine food web. On the other hand, the presence of pathogenic bacterial species in the tested samples indicates improvement necessity of ballast water treatment systems used on vessels.

The growing population and the development of industries in all countries of the world have created a very important and complex issue for water supply to cities. Today, many parts of the world are facing the problem of water shortage and this problem cannot be easily solved. In addition to the proper use of water resources and preventing the loss of natural water, the establishment of regional water supply networks is effective in meeting the future needs of the people. A water distribution network (water supply network) is a set of interconnected pipelines used to transport and distribute water in a complex. In designing the water distribution network, factors such as the type of water distribution network, water pressure, water velocity, design flow, minimum pipe diameter, pipe material and many other factors should be considered. In this study, we have tried to design the water supply network of a part of Balikpapan city in Indonesia. The design method led to the determination of pressure values in the connection nodes, pipe diameters, flow rate and velocity in the pipes. All the existing criteria are considered in the design of the water supply network. Although this study has been implemented for a specific study area, it can be of great help to designers in designing the water supply network.

Suspended matter, phytoplankton and light attenuation were investigated in various North East Greenland, Svalbard and Siberian river mouths in 1992-1994. The amount of mineral suspensions well correlated with freshwater discharge in the case of tidal glacier bays, while such correlation in Siberian rivers and pack ice meltwater was not found. Freshwater phytoplankton species were found in Siberian estuaries only and in two other ecosystems marine and ice phytoplankton species prevailed. The light attenuation connected with freshwater discharge seems to be a key factor limiting primary production in coastal Actic waters in the summer. The amount of glacial suspensions well correlated with the salinity drop in the case of Svalbard, while Siberian river estuaries produced very turbid waters with the suspension loads not correlated to freshwater or depth.

Mine drainage and discharge of salt waters into water bodies belong to main environmental issues, which must be appropriately addressed by the underground coal mining industry. The large area of exploited and abandoned mine fields in the Upper Silesia Coal Basin, as well as the geological structure of the rock mass and its hydrogeological conditions require the draining and discharge of about 119 million m3/yr of mine waters. Increasing the depth of mining and the necessity of protection of mines against water hazard result in increased amounts of chlorides and sulphates in the mine waters, even by decreasing the total coal output and the number of mines. The majority of the salts are being discharged directly into rivers, partly under control of salt concentration, however from the point of the view of environment protection, the most favorable way of their utilization would be technologies allowing the bulk use of saline waters. Filling of underground voids represents a group of such methods, from which the filling of goaves (cavings) is the most effective. Due to large volume of voids resulting from the extraction of coal and taking the numerous limitations of this method into account, the potential capacity for filling reaches about 17.7 million m3/yr of cavings and unnecessary workings. Considering the limited availability of fly ash, which is the main component of slurries being in use for the filling of voids, the total volume of saline water and brines, which could be utilized, has been assessed as 3,5–6,5 million m3/yr