METAL MOBILIZATION FROM WATER-DISTRIBUTION SYSTEMS OF BUILDINGS SERVICED BY LEAD-PIPE MAINS

Studies were made of the mobilization of metals from the water-distribution systems within several types of buildings, many of which are serviced by old lead-pipe mains, in Halifax, Nova Scotia. The study examined 36 single-family houses, three apartments in a high-rise building, and one school. In many homes, water that stood in pipes overnight developed relatively large concentrations of copper, lead, and zinc. In total, 70% of the standing water from single-family homes had lead concentrations exceeding the 0.01 mg/L criterion for lead in drinking water. The 30 single-family homes serviced by municipal mains made of lead did not have significantly larger lead concentrations than the six homes serviced by other types of piping. This suggests that the source of lead in drinking water is metal dissolving from the water-distribution systems within the homes, rather than from the lead service lines.