Problems with meeting new (10 μg/L) standard for lead in drinking water: Polish perspectives

In the current (2011) edition of ‘Guidelines for Drinking-water Quality’, the World Health Organization sets the guideline value for the concentration of lead in drinking water at 10 μg/L. This value, however, is a provisional one on the basis of treatment performance and analytical achievability. It is extremely difficult to achieve lower concentrations by central conditioning, such as phosphate dosing. Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption has set 10 μg/L as a target parametric value. The parametric value was 25 μg/L until December 2013. In Poland, the 10 μg/L standard came into force on 1 January 2013. A tap survey based on random daytime sampling (RDT) was conducted in 15 water supply zones in Poland. A total of 1440 RDT samples were collected during the period 2007–2012. The survey revealed that on average 8.4% of samples collected show lead concentrations exceeding 10 μg/L. In some water supply zones, the percentage of non-compliant samples reached 60%. This suggests that a substantial number of water companies in Poland will have to undertake significant measures to achieve proper quality standards in water supplied to consumers.