Author(s): Lu Chang

Linked Author(s):

Keywords: Drinking water supply; Lead contamination; Lead solder; Brass fixtures;

Abstract: Lead (Pb) is a toxic heavy metal that may be present in household drinking water supply systems fitted with lead-containing fittings and fixtures. Worldwide there have been a number of excess lead incidents in drinking water supply systems, raising public health concerns. Even though lead pipes are not used in drinking water supply system of Hong Kong, excess lead has been found in the drinking water of high rise buildings of public rental housing (PRH) estates. It is suspected that the water is contaminated by the lead-solder joints and brass components in the supply chain. The objective of this study is to understand the lead release characteristics of a drinking water supply pipeline with lead-solder joints and brass fixtures under stagnant and flowing conditions. Leaching experiments in stagnant water are carried out using a brass valve and a lead solder joint connected with copper pipes. The results show that the mass of lead released from the brass valve and lead-soldered joint increases non-linearly with time and can be predicted using the Fickian diffusion law. Lead concentration measurements are conducted in lead-contaminated water supply chains consisting of components dismantled from (PRH) estates. High lead concentration is observed at the location of brass components and near locations of clusters of lead-solder joints. The lead concentrations of water supply chains with lead-solder joints are several times higher than that without lead-solder joints.

DOI: https://doi.org/10.3850/38WC092019-1895

Year: 2019