St. Paul Replacing Every Lead Pipe With Copper

St. Paul, MN, is trying to replace all its lead pipes with copper in a project that will not be finished for another two decades.

The effort started when St. Paul realized it was above federal levels for lead in water, according to Minnesota Public Radio. The U.S. EPA forced St. Paul to remove 7 percent of its lead service lines for three consecutive years. But once St. Paul brought lead levels back under levels permitted by the federal government, it decided to keep attacking the lead problem, according to MPR.

Jim Bode, who worked in St. Paul's water utility laboratory when the city was still in violation, described the city’s experience.

"No one likes to fail," he said, per MPR. "Getting served a notice of violation is a failure in our industry. So, yeah, it was stressful."

The effort to replace all lead pipes brings risks. Ripping up lead service lines can actually increase lead levels.

“Cutting a lead service line can cause flaking in the protective scale lining a lead pipe no matter where the cut occurs. And flaking can last for months,” the report said.

But now the utility treats its water in a way that aims to prevent elevated lead levels.

“At the utility's plant three miles north of downtown St. Paul, murky surface water flows through a series of indoor pools where it is softened, filtered and ultimately treated with sodium hydroxide to raise the water's pH, a measure of its hydrogen ion concentration. Raising the water's pH allows a thin coat of scale to form inside the lead service lines, which prevents the corrosion that leaches lead particles into water,” the report said.

“It took time for St. Paul to perfect its method, but the pH strategy is working well now and is largely responsible for the utility's success in driving down its lead levels to below federal limits,” the report said.

The utility offers customers clearcut information about lead concerns.

The EPA currently says that if more than 10 percent of tap water samples “exceed the lead action level of 15 parts per billion, then water systems are required to take additional actions.

To read more of our lead contamination stories visit Water Online’s Drinking Water Contaminant Removal Solutions Center.