In 1991, the US EPA published the ‘Lead and Copper Rule’ (LCR) regulation to address the widespread legacy use of lead pipes for potable water delivery and service lines. While well intended, the regulation received immediate push-back from municipal water utility companies that cited compliance with the regulation was too difficult to implement in the LCR’s time-line and owner-utility responsibility was ill-defined. As a result, the American Water Works Association (AWWA) sued the EPA in 1993 and a Federal Appeals Court partially sided with the AWWA. After several years of back and forth, the LCR was amended in 2000 to allow for utility companies to perform ‘partial replacements’ of water delivery lines. This in essence made the problem worse, as it allowed for the utility companies to replace main water lines, but leave the lead service lines intact and the responsibility of the landowner to complete the replacement. This has left many homeowners unsure or falsely sure of whether or not their service lines are made of lead.

This issue has come to the forefront of the Nation’s attention due to the recent problems found in Flint, Michigan. Flint is not alone in their plight in dealing with this issue, nearly all urban areas have used and continue to have lead service and distribution lines. This problem is particularly worse in older and larger cities including Washington, DC, Boston and Philadelphia due to scarce records of the original pipe installations. Considering this history, there is a current need to rapidly and cost effectively identify the service line material supplying water to homeowners and residents in urban areas.

While non-destructive (NDE) methods exist to provide some vision of buried infrastructure (such as closed circuit television, electromagnetic induction, ground penetrating radar, wave impedance probe, or infrared thermography), none are intended to quickly and accurately characterize the material of a service pipe. Drexel researchers have created a new system and process that monitors the presence of lead by using propagating stress waves through a length of pipe. The Drexel process takes advantage of the significantly different velocities that stress waves propagate within various materials, to create a quick, simple, reliable, and cost-effective system for evaluating the presence of lead.