The paper presents the results of research on selected parameters characterising the quality of surface and ground waters in a small densely wooded lowland catchment. The catchment is situated in the central part of the Wielkopolska region, about 20 km to the northeast of Poznań (in the Zielonka Forest Complex). In the hydrological years 1998–2002, the nitrate content of water in the Hutka watercourse (surface water) was on the level corresponding with water purity class I while the concentrations of phosphates, dissolved oxygen and nitrites corresponded with class II or III (according to Polish standards). Highly concentrated nutrients were the main pollutants of groundwater in the catchment.

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