The aim of this paper is to analyse changes in the physicochemical elements in groundwater in the vicinity of a small municipal solid waste landfill site located within the territory of the European Union on the basis of 7-year hydrochemical research. Samples of groundwater and leachate near the examined landfill were collected four times a year during two periods, between 2008 and 2012 during the use of the landfill and between 2013 and 2014 at the stage of its closure. The research results were analysed on the basis of general physicochemical properties: pH; total organic carbon (TOC); electrical conductivity (EC); inorganic elements: Cr, Zn, Cd, Cu, Pb, Hg; and one organic element—polycyclic aromatic hydrocarbon (PAH). The analysis was carried out in accordance with the EU and national legislation requirements regarding landfill monitoring. The assessment of the groundwater and analysis indicators of the leachate pollution allowed interpretation of the impact of the municipal solid waste landfill on the state of the water environment in the immediate vicinity . The results show that the increased values of Cd, EC, and TOC turned out to be the determinants of the negative impact of leachate on the groundwater quality below the landfill. The integrated water threat model determined the potential negative impact of a landfill site. The extent depended on local environmental conditions and the self-cleaning process. Deterioration of the chemical status in the quality of the groundwater within the landfill area was a consequence of the lack of efficiency of the existing drainage system, which may result from the 19-year period of its use. The applied correlation relationship between physicochemical elements between leachate and groundwater with a time shift due to the extended time of migration of contaminants or mass transfer in waterlogged ground can be an important tool to identify the threat of groundwater pollution in the area of landfill sites.

This paper presents the changes in concentration of seven biogenic indices in the Wisłok River water and determines the water treatment processes required in order to obtain water fit for consumption. The investigations were conducted during 2004–2013, and water samples were collected at a measuring-control point was situated at 67.9 km on the river at the surface water intake for the water supply to the Rzeszów city dwellers. Analysis of the research results allows for the forecasting of technological and organizational changes in the treatment processes of the abstracted water. It was found that only the mean concentration of Kjeldahl nitrogen exceeded the value admissible for class I, which allowed the Wisłok River water to be classified as class II with good potential and determined the water quality category as A2, which indicates the necessity for typical performance physical and chemical treatment. Downward trends in the contents of the tested nutrients occurred during the period of investigation, except for nitrite nitrogen. Statistically significant downward trends were registered for ammonium nitrogen, Kjeldahl nitrogen, total nitrogen and phosphates. The decline in nutrient concentrations in the water of Wisłok is a tangible result of the introduction of new standards of water resource management in the catchment, compliant with the European Union legislation.

Spatial and time changeability of surface water quality results from anthropogenic activities in the catchment area [1,2], growing pollutant amount [3], and environmental management [4]. The EU Water Framework Directive (WFD) [5] stipulates that the waters of all European strongly changed water bodies must achieve good ecological potential and good chemical status by 2015 [6, 7]. A considerable part of waters bodies in Europe is exposed to the risk of not achieving a good state by this year [8]. Therefore, water quality assessment and determining the factors affecting its changes have been the subject of numerous papers [9][10][11][12][13][14][15][16]. The assessment process faces two main problems: complexity and uncertainty [17] -both due to high social and economic costs [6,18]. Changeability of water chemical parameters should be assessed on the basis of monitoring programs in order to detect changes in their quality status [6,19,20]. This aims to determine the main actions targeting restoration of good status of waters, which ensures that their quality would respond to the aims suggested by WFD for the human population, considering the principle of sustainable development and public health [21,22]. Problems with water quality are associated with a great number of nutrients originating from surface runoff from urban areas [23] (including sewage discharge) [2, 24] and from agricultural areas [7,25].Pol. J. Environ. Stud. Vol. 24, No. 4 (2015), [1633][1634][1635][1636][1637][1638][1639][1640] Original Research Changeability of Oxygen and Biogenic Indices in Waters Flowing through Areas under Various AnthropopressuresWłodzimierz Kanownik*, Agnieszka Policht-Latawiec AbstractSeasonal and monthly changes of biogenic and oxygen indices in the water of two streams in 2007-10 are discussed in this paper. The streams have similar catchment areas that area managed and used in different ways. The Krzyworzeka stream catchment is covered by rural areas, whereas the Serafa stream flows through built-up and urbanized areas.Statistical testing using U Mann-Whitney's nonparametric test was conducted to determine the differences of oxygen and biogenic water quality index values between the growing season and outside the growing season. Statistically significant decreases in ammonium, nitrate, and total nitrogen concentrations, as well as oxygen dissolved in Krzyworzeka Stream, were registered during the growing season. In the Serafa water only the concentrations of dissolved oxygen and biological oxygen demand decreased significantly. On this basis it was established that in clean waters vegetation development considerably influences the content of biogenic compounds. Serious pollution of stream water causes vegetation and the intensity of biochemical processes in water to not cause any clear reduction in biogenic compound concentrations.

The paper aims to determine the most significant physicochemical indicators of the effects that a lined landfill in southern Poland has had on groundwater quality. The results of the tests of groundwater and leachate water from the landfill for the period 2009 to 2016 were subjected to a detailed statistical analysis based on the 10 physicochemical parameters. A factor analysis was conducted considering the European Union and national requirements for landfills using analytical and statistical tools. The leachate contamination indicators from a landfill were analysed to reveal their interaction with the groundwater. The assessment indicated that there was an elevated and statistically significantly higher electrical conductivity and copper and total organic carbon concentrations in groundwater hydraulically downgradient of the landfill. The assessment also indicated that there were significant differences in the correlations between chemical parameters downgradient of the landfill and that there was a trend of increasing concentrations of some chemical constituents in groundwater. The adverse effects of the landfill were due to the deposited amount of waste exceeding 10 Mg per day. The impact was noticeable despite low and decreasing concentrations of heavy metals (Hg, Cu, Cd, Pb and Zn) in the leachate. The deterioration of the chemical state of the groundwater in the landfill vicinity could result in the extended time of pollutant migration or mass transport in the irrigated soil medium due to the limited efficiency of the leachate intake system or sealing screen after more than 20 years of landfill operation.

The paper presents an analysis of 20 physicochemical elements in the Bobrza River water sampled above and below the treated sewage discharge point. Sitkówka mechanical and biological sewage treatment plant with a value of 289 000 People Equivalent discharges on average 51 000 m 3 of treated sewage daily, which makes up 29% of mean daily flow in the Bobrza River. On the basis of hydrochemical analyses it was stated that the discharge of treated sewage led to worsening of 18 out of 20 studied water quality indices in the Bobrza River. In the river water below the sewage discharge statistically significantly higher values of electrolytic conductivity, dissolved solids, calcium, magnesium, sodium and potassium were registered. A decrease in dissolved oxygen content in the water and increase in its electrolytic conductivity caused a change of water quality class in the Bobrza River from the maximum potential to potential below good. On the other hand, increase in concentrations of dissolved solids and sulphates caused a change of the water class from the maximum potential to good potential. Statistical factor analysis (FA) made possible a reduction of a set of 20 physicochemical elements to four mutually orthogonal factors explaining 95% (above the treatment plant) and 96% (below the treatment plant) of the internal structure of primary data. The first factor is connected with point source pollution (sewage discharge), the second describes oxygen conditions in water, the third results from seasonality and is responsible for the pollutants from natural sources, whereas the fourth factor has not been unanimously defined yet.