Control of selected quality indicators of water intended for consumption at the draw-off point - the example of the city of Krakow

Abstract

This article presents the results of the measurements carried out in the period from June 2020 until May 2021. Four water quality parameters were tested, i.e. turbidity, total iron, free chlorine and coliform bacteria in raw water, treated water and in 50 selected draw-off points in the water supply zone of the Water Treatment Plant „Raba” (ZUW “Raba”). Samples were taken every week throughout the study period. Studies have shown that the above mentioned indicators at the draw-off points turned out to be significantly below the required values. The water at the draw-off point met Polish and European quality requirements. The maximum water turbidity value did not exceed the required 1 NTU and was maintained at a similar level, i.e. 0.97 NTU at the intake point and 1 NTU in the treated water. The content of total iron remained at a similar level, i.e. 0.03 mg/dm3 in water at draw-off points and 0.02 mg/dm3 in treated water. The value of free chlorine decreased from 0.73 mg/dm3 to 0 mg/dm3 (median). The number of colony-forming units of coliform bacteria was 0, which is a result consistent with the requirements  Studies have shown that the water supplied to consumers meets the parameters required by law, which gives grounds to conclude that there is no secondary pollution in the water distribution system.