Lead in Drinking Water in Slovenian Kindergartens and Schools

The purpose of the work is to determine how high are the concentrations of lead in drinking water in older Slovenian kindergartens and primary schools and to demonstrate that lead can also migrate from newer materials used for the construction of water distribution networks. To determine the concentrations of lead in drinking water, it is needed to take 250 ml of drinking water that stood in the pipes from 8 to 18 hours. It is also applied a method for determining the migration from different materials. An old lead pipe is utilized, as well as new materials (PEX-Al-PEX, copper, galvanized pipes and stainless steel pipes). Sampling showed that 6 samples of 39 had levels of lead higher than 10 mu g/l, two of them highly exceeded that level. Negative correlation between the level of pH and concentration of lead in drinking water is moderate. Implementation of lead migration from various types of pipes demonstrated the migration from galvanized pipes in all simulants. Furthermore, the migration of lead from galvanized pipes is dependent on water temperature. The migration was confirmed from the lead pipe as expected. Study points to a problem with elevated concentrations of lead in drinking water faced by older kindergartens and primary schools in Slovenia. All concentrations of lead after flushing the pipes were below the 10 mu g/l, which shows that the most effective action to lower the concentrations of lead is flushing the water pipes. For the purposes of national monitoring of drinking water is necessary to apply a better method for determining lead levels in drinking water namely the sampling of water that stood in the pipes at least 8 to 18 hours. This study has demonstrated the migration of lead from galvanized pipes. This material is also installed in 54 % of kindergartens and primary schools that participated in the study.