THE RELATIONSHIP BETWEEN IRON PARTICLES IN WATER MAINS AND LEAD RELEASE

Abstract

The impact on human health caused by lead release has resulted in stringent lead regulations, which limit the drinking water concentration of lead to 10µg/L. In order to meet regulation guidelines, sources of lead are being removed from the distribution system and premise plumbing. Lead service lines (LSLs) are replaced to minimize the effect of lead release, with LSL contributing as much as 50-75% of total lead at the tap. Adsorption of lead on galvanized iron corrosion scales have been shown to increase lead release in LSL replacements, which is very concerning for utilities considering replacing the LSLs. Adsorption of lead on to iron minerals has been hypothesized as a mechanism for lead exposure. With the significant presence of unlined cast iron pipes in Halifax, the objective of this thesis was to determine the relationship between the iron particles found in cast iron pipes and lead release at the tap.