A minimally-invasive, on-site identification method for lead-lined water service lines: A case study in Trenton, NJ

Abstract

Lead exposure is a well-understood health risk, both acutely via lead poisoning, and at low dosages for a prolonged period. Historically, lead was commonly used in many industries, including in paint, gasoline, and plumbing. In the 21st century, high-profile cases of elevated lead levels in residential tap water systems in Washington, D.C. (2003), Flint, MI (2014), and Newark, NJ (2016) made replacing lead pipes a priority for many municipalities. Replacement became particularly important for cities with large amounts of housing built before the 1986 federal lead pipe ban. However, most municipalities do not have accurate or complete records of where lead pipes were installed, particularly on the privately-owned, homeowner side of the line, and steel pipes lined with lead often go undetected by conventional identification methods. In this paper, we propose and evaluate a novel method of identifying lead-lined water service lines using a portable x-ray fluorescence (XRF) device. Using a suit of 656 samples from pipes replaced in Trenton City and Hamilton, NJ, we found that an XRF analysis on the outer surface of the pipe was capable of detecting ~70% of lead-lined samples, and that ~90% samples with an outer surface reading of at least 10,000 ppm were visibly lead-lined. This minimally invasive approach allows utilities to quickly and accurately identify lead service lines without cutting or excavation.