Summary:

The subject of the study is quaternary groundwater intaken by 10 drilled wells numbered as follows: S-7a, S-9a, S-11b, S-12b, S-15a, S-16a, S-17a, S-18a, S-20a and S-21 constructed in the period 1971 - 1993 and forming "Stare ujęcie" located in Stalowa Wola. Total manganese concentration in waters of "Stare ujęcie" intake falls within the range from 0.001 mgMn•dm-3 to 2.57 mgMn•dm-3, and total iron - from 0.01 mgFe•dm-3 to 6.50 mgFe•dm-3. Given the quality classification of "Stare ujęcie" waters - they predominantly belong to 3rd and 4th class and their quality is unsatisfactory. The chemical composition variability of the intaken waters is spatially presented in the study in the form of hydroisolines, while the temporal variability was discussed descriptively and with the use of statistical coefficient of variation. The variability of total iron concentration in waters of "Stare ujęcie" is very high in the case of wells S-7a and S-17a, in the case of wells S-9a, S-18a, S-20a and S-21 - it is high, while in well S-15a the variability is medium. Concentration of total manganese in waters of wells S-15a and S-18a is characterized by low variability, in waters of wells S-7a, S-9a and S-21 - by medium variability, while in waters of wells S-17a and S-20a its variability is high.