Get the lead out
More than 18 million people in the United States are at risk from water pipes that leach lead, which can cause brain damage, learning problems, premature births and high blood pressure, among other serious health effects. But the process for replacing entire municipal water systems can be very expensive and slow, as seen in Flint, Michigan, and more recently in Newark, New Jersey. Now, researchers led by Ashok Gadgil, professor of civil and environmental engineering, have devised a novel solution to this problem. The team found that when a low voltage power source, about 1V, is connected to a lead pipe filled with a harmless phosphate solution and to a conductive wire within the pipe, an insoluble lead phosphate layer rapidly forms on the inside surfaces of the pipe. In about two hours, the power source and the wire can be disconnected and removed. The newly formed protective scale results in a 99% reduction of lead leaching rates, according to preliminary laboratory experiments performed on lead pipes without any scale. While pipe replacement remains the best solution, this technology could be an important stopgap for communities where timely pipe replacement is not economically feasible.