Rivers are considered as one of the main resources of water supply for various applications such as agricultural, drinking and industrial purposes. Also, these resources are used as a place for discharge of sewages, industrial wastewater and agricultural drainage. Regarding the fact that each river has a certain capacity for acceptance of pollutants, nowadays qualitative and environmental investigations of these resources are proposed. In this study, qualitative investigation of the Talar river was done according to Oregon Water Quality Index (OWQI), National Sanitation Foundation Water Quality Index (NSFWQI) and Wilcox indicators during 2011–2012 years at upstream, midstream and downstream of the river in two periods of wet and dry seasons. According to the results of OWQI, all of the values at 3 stations and both periods are placed at very bad quality category and the water is not acceptable for drinking purposes. According to NSFWQI, the best condition was related to the upstream station at wet season period (58, medium quality) and the worst condition was related to the downstream in wet season period (46, very bad quality). Also the results of Wilcox showed that in both periods of wet season and dry season, the water quality is getting better from upstream station to the downstream station, and according to the index classification, the downstream water quality has shown good quality and it is suitable for agriculture.

This study illustrates the benefits of statistical techniques to analyze spatial and temporal variations in water quality. In this scope water quality differentiation caused by anthropogenic and natural factors in the Tahtali and Balçova reservoirs in western Turkey was investigated using discriminant analysis-DA, Mann Whitney U techniques. Effectiveness of pollution prevention measures was analyzed by Mann Kendall and Sen’s Slope estimator methods. The water quality variables were divided into three groups as physical-inorganic, organic and inorganic pollution parameters for the study. Results showed that water quality between reservoirs was differentiated for “physical-inorganic” and “organic pollution” parameters. Degree of influence of water quality by urbanization was higher in the Tahtali reservoir and in general, no trend detection at pollution indicators explained by effective management practices at both sites.

The data set of the Warta discharges in Poznań (Poland) is one of the largest in the world as the daily observations of river stages have been conducted without interruptions since January, 1st, 1822. The Poznań measurement profile is situated in the 243.6 km and closes the catchment area of approximately 25 thousand square kilometers. The data used as the input in the paper were daily values of the Warta discharges in Poznań in the years 1822-2012. The climate in Poznań, a city situated in the centre of the Wielkopolska (Greater Poland) region, is relatively stable (Miler et al. 2005). Also the Warta River runoff shows considerable stability, especially in terms of mean annual values. Short-term trends are random in character. It was found that the Jeziorsko reservoir (total storage volume of 203 000 000 m3, officially put to use on September, 9th, 1987) significantly reduced daily variability of the flows and reduced peak discharge of the flood wave in the summer of 1997 on the Warta River at Poznań. The calculated periodogram for mean annual discharges of the Warta River in Poznań shows that there are main periodicities of ca. 10 year lengths. The research of the Provincial Inspectorate for Environmental Protection (WIOŚ) in Poznań shows a gradual improvement of water quality in the Warta River in Poznań.

The work is an attempt to assess piped water quality in four counties located in east central Poland. Piped water was analysed for three successive years in each county. Water samples were tested for the following physical and chemical parameters: turbidity, colour, conductivity, taste, odour, pH, nitrates (III), nitrates (V), iron and manganese. They were compared with the current standard values. Preliminary data analysis included an analysis of maximum and minimum values of physical and chemical parameters, and it revealed that turbidity, colour, iron and manganese contents exceeded the permissible standards in all the counties. Percentages of parameters exceedances and mean values of the exceedances were used to rank the counties in terms of water quality. The ranking was obtained by means of multidimensional comparative analysis. It was demonstrated that best quality water was supplied by Węgrów County water supply system which was followed by Mińsk Mazowiecki County. The third rank was assigned to Łosice County and the poorest quality water was found to be supplied by Siedlce County water supply system.

Saprol 190 EC (triforine) and Rubigan 12 EC (fenarimol) diluted in 6 types of water were applied against rose rust Phragmidium mucronatum Cooke. No adjuvants were added to the emulsion except when the spray mix was made using water from Poznań prepared in 2 variants: with an addition of Citowett AL and without it. Independently on the plant protection product type, efficacy of fungicides diluted in well water from Szczepankowo, Kościan or Śmigiel was better than when they were diluted in water after reversed osmosis. However, no type of water exerted any significant effect on efficacy of the investigated fungicides independently on the year of studies, although, in 1999, a better biological activity was shown by Rubigan 12 EC diluted in water from Kościan and Poznań than when they were diluted in water after reversed osmosis. The fungicides were most effective after addition of Citowett AL, however, a visible effect of this adjuvant showing increased rose protection against rose rust was found only in 1998.

In the study, environmetric methods were successfully performed a) to explore natural and anthropogenic controls on reservoir water quality, b) to investigate spatial and temporal differences in quality, and c) to determine quality variables discriminating three reservoirs in Izmir, Turkey. Results showed that overall water quality was mainly governed by “natural factors” in the whole region. A parameter that was the most important in contributing to water quality variation for one reservoir was not important for another. Between summer and winter periods, difference in arsenic concentrations were statistically significant in the Tahtalı, Ürkmez and iron concentrations were in the Balçova reservoirs. Observation of high/low levels in two seasons was explained by different processes as for instance, dilution from runoff at times of high flow seeped through soil and entered the river along with the rainwater run-off and adsorption. Three variables “boron, arsenic and sulphate” discriminated quality among Balçova & Tahtalı, Balçova & Ürkmez and two variables “zinc and arsenic” among the Tahtalı & Ürkmez reservoirs. The results illustrated the usefulness of multivariate statistical techniques to fingerprint pollution sources and investigate temporal/spatial variations in water quality.

The aim of this study was to examine the changes in the chemical composition of shallow groundwater and its quality that have occurred in the last decade in an agriculturally used, heavily populated and characterized by a complex geological structure, catchment of the Stara Rzeka river, located in the flysch part of the Outer Carpathians. Water samples were collected during 2013 from 19 still operating wells. Analyses of pH, electrolytic conductivity and chemical composition by ion chromatography were conducted. The obtained results were compared with the results of studies conducted in 2003 for the same wells. The quality of groundwater and its suitability for consumption was assessed based on the regulations currently existing in Poland. 21% of the wells still do not meet the requirements for drinking water in terms of at least one component. However, there was a decrease in the concentration of mineral forms of nitrogen and phosphorus in most of the wells and their mean concentration as compared to 2003 was reduced. In terms of physical and chemical characteristics groundwater of this region is typical of the hypergenic zone of the temperate climate. The highest concentrations were observed for Ca²⁺ and HCO₃^- ions, while K⁺ and Cl^- were characterized by the largest variability. Principal Component Analysis (PCA) demonstrated that the factors determining the quality and chemical composition of the analyzed waters include the composition of bedrock (mineralogy of the rock environment) and human economic activity, and that they have not been significantly changed over the past decade.

Chemical industries in Onitsha urban area of southeastern Nigeria have been discharging large quantities of effluents into surface streams. These streams are the primary sources of water used by poor households for domestic purposes. This study examines the effects of effluents on the physicochemical and microbiological characteristics of the recipient streams. This objective was achieved by collecting eight effluents and twenty-two water samples from control points, discharge lo-cations and exit chutes of the effluents for analysis. The results of the study characterised the effluents and their effects on the recipient streams. The effluents cause gross pollution of the streams as most of the parameters including pH, total dis-solved solids (TDS), turbidity, biological oxygen demand (BOD), chemical oxygen demand (COD), Mg, NO3, Fe, Cu, Pb, Cr, total heterotrophic count (THC) and total coliform group (TCG) returned high values that exceeded the World Health Organisation’s (WHO) benchmark from 2011 for drinking water quality. Only dissolved oxygen (DO), Na, Zn, Ca, and Na returned values lower than the WHO guideline. E. coli was found in all the samples; TCG was also high. This paper, there-fore, recommends that the effluent generating industries should treat their effluents before disposal.

Water quality is an important criterion for evaluating the suitability of water for drinking and domestic purpose. The main objective of this study was to investigate the physicochemical characterization of groundwater for drinking water con-sumption. Ten captured sources were selected from three aquifers including the Guelma Mio-Plio-Quaternary alluvial ba-sin; the Senonian Heliopolis Neritic limestone aquifer, and the Eocene limestones of Ras El Agba-Sellaoua aquifer. The analyses concerned the periods of high water in May 2017 and low water in August 2017. Twelve parameters were deter-mined for the water samples: pH, T (°C), EC, Ca2+, Mg2+, Na+, K+, Cl–, HCO3–, SO42–, NO3–, TH (hydrotimetric degree), TAT (total alkalinity titration). The interpretation of the various analytical results allowed the determination of the chemical facies and the classification of the groundwater aquifers as follows: (i) in the alluvial layer, the gypsiferous marl substratum and the clays of the three terraces (high, medium and low) have given the water a chlorinated calcium chemical facies in the east part of the study area and travertines feeding partly alluvial layer, and have given a bicarbonated calcium water facies in the west, (ii) in the Senonian of Heliopolis limestone and Eocene carbonate formations of Ras El Agba- -Sellaoua, the chemical facies are calcium bicarbonate. Water isotopes (δ18O and δD) helped to determine the origin of groundwater. Overall, the groundwater in the area is hard and has significant to excessive mineralization. It is progressivelydegraded in the direction of flow, especially in the Guelma alluvial aquifer.

Based on chemical analyses, the quality of ground waters for drinking, agricultural and industrial purposes was deter-mined in Rafsanjan Plain-Iran. Samples for analyses were taken from 22 wells in 2012. Because of high water hardness and total dissolved solids content, water was found to be unsuitable for drinking purposes. Water quality for agriculture was determined with the use of the Wilcox method. Among the analysed water, 10.33% were attributed to C3-S1 class (high electrolytic conductivity and low sodium adsorption ratio), 59.5% to class C4-S1 (very high EC and low SAR) and 30.17% to class C4-S2 (very high EC and medium SAR). 89.67% of studied wells were unsuitable for agriculture. Because of corro-sive water properties all but two wells on Rafsanjan Plain were undesirable for use in the industry. The results of qualitative analyses were presented in GIS and in databases to support making decision and management of groundwater on Rafsanjan Plain.

According to the Nitrate Directive it is necessary to established a protective belt (ecotones) around lakes. Inside these belts, it is forbidden to use fertilize for agricultural purposes. It is believed that it is the most imported measure to protect water quality in the lake. The analysis were conducted to estimate the sources of nitrogen entering the waters of the lake. Some analysis were conducted to estimate the sources of nitrogen entering waters of the lake. It was proved that the biggest load (more than 80%) of contamination is entering the lake with water flowing in streams and ditches. Only 10% of the chemicals are entering the lake with the groundwater filtrating to the lake. It is very important to use a proper methods of agriculture with proper methods of fertilization in the whole area of river basin flowing to the lakes.

The objective of the study was to characterise the quality of surface waters in order to de-termine their vulnerability to pollution by nitrogen compounds from agricultural activity, as well as to specify the areas with increased exposure, where nitrogen runoff from agricultural sources has to be reduced. It was necessary to determine surface waters liable to pollution by these compounds due to the fact that agricultural production should be carried out in the way which limits and prevents water pollution by nitrogen compounds of agricultural origin. The study addressed the following is-sues: the concentration of nitrogen compounds in the surface waters of the Middle Odra Basin, and the extent of eutrophication in flowing inland waters (with nitrogen as the main nutrient). The results have been plotted in figures and gathered in tables.

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.