Release of Metals from Different Sections of Domestic Drinking Water Installations

Abstract

Different metals can leach from piping materials into the tap water, which can be of health concern. This study investigated in which amount abundant metals were released from different parts of domestic installations into the cold tap water. For the approximate spatial allocation of the metal releasing sources, a sequential water sampling protocol was used after three hours of stagnation time representing the first five litre of the water column. After stagnation ten sample volumes were collected in series. Existing facilities of domestic installations constructed with different plumbing materials were examined predominantly from residential buildings. The elements Al, As, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sb, Se, U and Zn were detected by means of ICP-MS. In total 16 water pipe strands of 11 domestic installation systems were examined. They comprised 401 single water samples and 5,614 single parameters. Depending upon the type of plumbing, different courses and concentration ranges of the elements could be measured in the tap water samples. Terminal taps or installation parts were in all investigated systems responsible for a release of nickel and in several cases of low concentrations of cadmium. The concentration courses of the element zinc proved as a good indicator for the allocation of the metal source to a brass containing section of the installation (zinc as an alloy component of brass). One can conclude that sequential water sampling protocol in combination with multi-element detection can be a valuable non-destructive method for drinking water-hygienic investigations of domestic installations.