Partial replacement of lead pipe in the U.S. results in a galvanic connection of lead and copper pipe. To examine the galvanic effect between the lead pipe and copper pipe, a series of experiments was conducted with different water types (different chlo-ride-to-sulfate mass ratios (CSMR) and disinfectant doses) under stagnant conditions. During the 11-week experimental period, high galvanic currents between the lead and copper pipes were observed and were influenced by the CSMR of the drinking water. That is, when the CSMR was higher, the corrosion rate of lead pipe was increased. The results also indicated that there was a linear relationship between the galvanic current and the pH at the surface of the lead and copper pipe junction, which is consistent with the Lewis acidity of Pb~2+ that was released at the anode. There was also a linear trend between total lead in the water and the galvanic current. Both the soluble and total lead in the water was dramatically increased when the lead pipe was connected to copper pipe. These results indicate that partial lead line replacements can cause galvanic corrosion of lead pipe and subsequently increase lead contamination of drinking water.
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