Galvanic impacts of partial lead service line replacement on lead leaching into drinking water

Due to jurisdiction issues, partial lead service line replacement (and not full) is widely implemented in the United States (US), in order to alleviate lead-in-water problems. A portion of the lead service line is replaced with copper, and the dissimilar pipe materials are then connected to restore drinking water service. This practice creates an electrochemical or galvanic cell, which can accelerate corrosion of the lead pipe by galvanic action. The adverse effects of such connections in the context of lead leaching were verified in experiments of simulated lead service line replacement. Galvanic connections between lead pipe and copper pipe increased lead release, compared to lead pipe alone. The extent of galvanic corrosion was dependent on drinking water quality, and specifically on the Chloride to Sulfate Mass Ratio (CSMR) of the water. Higher galvanic currents between lead and copper were measured when the CSMR was high, mechanistically explaining the trends in lead release. Consideration of galvanic corrosion long-term impacts after partial lead service line replacements is deemed important, on the basis of the results presented herein.