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The work presented the assessment of household wastewater treatment plants with drainage systems on the quality of groundwater in dug wells and deep water wells in the area of 3 selected communes (Drelów, Dębowa Kłoda and Urszulin), located in the Lublin province in south-eastern Poland. The investigations of the physicochemical composition of water from selected 28 dug wells and 2 deep water wells were conducted from June to July 2020, involving 9 measurement series. The microbiological studies consisted in 4 measurement series. The composition of the wastewater from primary settling tanks discharged to soil via drainage systems located in the vicinity of considered wells was also examined on a single occasion. The studies indicate that the water from wells are significantly polluted with ammonia, nitrites, as well as compounds of natural origin: iron and manganese. The presence of microbiological pollution of fecal origin was noted. The studies clearly indicate the possible pollution of the analyzed well waters with domestic sewage discharged to soil via drainage systems. Therefore, it necessary to take the actions aimed at improving the quality of groundwater in the Lublin province, including limitation of drainage systems, especially in the areas with unfavorable subsurface and hydrological conditions as well as low water supply coverage. The need to introduce changes in legal regulations and strategies for the development of technical infrastructure in counties, favoring the most efficient, as well as simple and inexpensive technologies, was indicated.

The study investigated the efficiency of removal of iron, manganese and indicator bacteria from potable groundwater by using carbonate-silica rock (opoka). The tests were performed in a laboratory in three filter columns supplied with water containing increased concentrations of iron and manganese. Two of the columns were filled with carbonate-silica rock with particle sizes of 2-5 mm; retention time for water in the columns was set at 1 h and 2 h. A third column was filled with 1-2 mm rock particles, with hydraulic retention time set at 1 h. High removal efficiencies were determined for iron, manganese and coliform bacteria and low removal efficiencies for psychro- and mesophilic bacteria. An increase in the alkalinity of the investigated water was also observed.

In this paper, the pollutant removal efficiency and the reliability of a vertical and horizontal flow hybrid constructed wetland (CW) planted with common reed, manna grass, and Virginia mallow were analyzed. The wastewater treatment plant, located in south-eastern Poland, treated domestic sewage at an average flow rate of 2.5 m3/d. The tests were carried out during five years of its operation (2014&ndash, 2018). The following parameters were measured: biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids, total nitrogen, and total phosphorus. The results showed that more than 95% of BOD5, COD, and total phosphorus was removed in the tested CW system. The average effectiveness of removal of total suspended solids and total nitrogen exceeded 86%. A reliability analysis performed using the Weibull probability model showed that the removal reliability in the tested CW was very high for BOD5, COD, total suspended solids, and total phosphorus (100%). The probability that the total nitrogen concentration in the treated effluents would reach the limit value (30 mg/L) established for effluents discharged from a treatment plant of less than 2000 PE (population equivalent) to standing waters was 94%. The values of all the pollution indicators in wastewater discharged to the receiver were significantly lower than the limit values required in Poland. The investigated hybrid CW system with common reed, manna grass, and Virginia mallow guaranteed stable low values of BOD5, COD, total suspended solids, and total phosphorus in the treated wastewater, which meant it was highly likely to be positively evaluated in case of an inspection.

The paper presents the results of research on the effects of removing pollution from domestic wastewater in two beds of constructed wetland systems with vertical flow. Bed I was planted with common reed (Phragmites australis Cav. Trin. Ex Steud.), whereas bed II with Glyceria maxima (Glyceria aquatica L.). The surface of each of the beds amounted to 30 m2, and the hydraulic load of each of them amounted to 0.033 m3·m-2·d-1. The study showed very good results in the removal of most of the analyzed indicators of contamination, which were similar in both analyzed beds. They were, respectively: 91 and 93% – for total suspended solids, 96 and 98% – for BOD5, 96 and 94% – for CODCr, 88 and 86% – for ammonia nitrogen and 87 and 88% – for total phosphorus. Much smaller effects were reported with regard to total nitrogen removal – 55% in bed I with common reed and 54% in bed II with Glyceria maxima. The tested beds also eliminated the number of coliform bacteria and faecal coliform bacteria quite effectively. Average effects of the removal of coliform bacteria in bed I and II were 99.74%, in the case of faecal coliform 98.06% and 97.94% respectively. Values of basic indicators of contamination (total suspended solids, BOD5 and CODCr) in the wastewater discharged from the analyzed beds met the requirements of the Regulation of the Minister of the Environment of 2014. The test results obtained in the first year of operation of the analyzed beds show that neither of the applied plants significantly improves the results of contaminant removal.