Contributions to drinking water lead from galvanized iron corrosion scales

摘要

This article summarizes a study that identified a previously overlooked potential source of drinking water lead: galvanized iron in-home plumbing with a historical lead service line. Lead from a service line can build up in corrosion scales inside galvanized in-home plumbing over decades and be released from these scales to tap water. This form of lead release can be exacerbated by hydraulic characteristics common to residential plumbing. The potential for galvanized plumbing to release substantial amounts of particulate lead—even long after lead service line replacement (LSLR)—has serious implications for Lead and Copper Rule (LCR) compliance as well as the effectiveness of partial or even full LSLR. Utility managers may be especially concerned about a source of lead located on private property that can nonetheless increase the risk of LCR noncompli-ance. In addition, the study raises questions about the effectiveness of typical corrosion control treatment (i.e., orthophosphates) to stem this particular type of lead release.