Summary:

In the article was presented variability of iron and manganese ions concentration during the decade 1993-2002 in the underground waters of „Bzin" water intake that supply water pipe for Skarżysko-Kamienna city. The Bzin water intake includes six drilled wells of 37 to 60 meters depth and 74 to 341 m³/h capacity that intake underground waters from carbonated, slotted Triassic formation. Conducted research indicated very high variability of analyses compounds. The analysis of Fe and Mn ions variability in the underground Triassic waters of Bzin intake showed that in the well II and III waters decreasing of Mn and Fe concentrations, in the wells I and Ia decreasing only of Mn concentration and increasing of Fe level, however in wells IIIb and IV increasing both Mn and Fe concentrations was followed during progressive exploitation. In case of Fe ions, concentration in exploited water reached up to 1,52 mg/dm³ (well I) and manganese up to 0,78 mg/dm³ (well Ia).
First class waters (very good quality) occurred throughout research period in the well 3b, and the worst third and forth class: in the year 1997, in the well 4, that was connected with high concentration of Fe and Mn ions, and throughout whole research period, in wells 1, 1a and 2 for the sake of Mn concentration.
In the well 3b area of Bin intake atypical phenomenon was affirmed, in which co-occurred in the intake Triassic waters the lowest Fe and Man ions concentrations, roof of Triassic aquifer was located lowest above sea level and the lowest piezometric pressure of deposition subarthesian Triassic waters took place.