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.