The Institute of Hydrology of the Leibniz Centre for Agricultural Landscape Research (ZALF) e.V. operates four groundwater monitoring wells in the Quillow catchment. The wells are located in the neighborhood of Dedelow near the stream Quillow and its tributary Peege. Altitude in meter: between 64 and 74 m a.s.l., Geographic latitude: 53,3665 N, Geographic longitude: 13,8030 E. Water samples are collected periodically at different dates in a year and at different depths. Each sample was analysed in the own hydrochemical laboratory where the parameters pH value, redox potential, electric conductivity, water temperature, oxygen, hydrogen carbonate, ammonium, phosphate, spectral absorption coefficient, chloride, bromite, nitrite, sulfate, sodium, potassium, magnesium, calcite, dissolved organic carbon, iron(II) and manganese were determined.