Why Does the U.S. Still Have So Many Lead Water Pipes?

Five years ago, the Flint Water Crisis woke Americans to the potential danger of lead in drinking water. Still, many onlookers might think that this is an isolated problem, endemic to a forlorn city long seen as an outlier from the rest of America.

While it's true that America's drinking water is safe and generally well-managed, it's also true that tens of millions of Americans rely on public drinking water systems that utilize vast lines of aging lead pipes and maintain delicate systems which prevent that lead from leaching in. Should these safeguards fail, many people could find themselves drinking dangerously tainted water.

Today, we know lead to be a highly toxic metal, particularly dangerous to children, but more than a century ago, we knew it simply to be dense and durable yet also soft and malleable. Moreover, lead is nearly impervious to rust and doesn't decay from soil contact. These qualities made it perfect for smaller pipes called service lines that branch off from larger water mains and carry water to buildings, where they must twist and bend to get to sinks, showers, and toilets. Plumbers also became enamored with lead fittings and solder to rig piping within houses.

"Despite lead being more expensive than steel or other pipes, lead pipes were a better investment for municipalities and building owners because they lasted so much longer," author Seth M. Siegel described in his recently published book Troubled Water.

"By 1900, twenty-three of the twenty-five largest U.S. cities, and 85 percent of all cities, were primarily using lead service lines," Siegel added, citing research by Werner Troesken, a Professor of History at the University of Pittsburgh.

While the use of lead for new drinking water lines slowed – eventually to a standstill – in the second half of the 20th century, there remains more than 6.1 million lead service lines in the United States, most prominently in Illinois and Ohio.

So then why isn't there a huge problem with lead poisoning nationwide?

The answer is that utilities insert innocuous chemicals into drinking water that create buildups of minerals that coat the interiors of lead pipes, sealing off the lead from the water. But these coatings can quickly break down if the chemical balance is disturbed. In Flint, all it took for the protective minerals to dissipate was switching Flint's drinking water source from Lake Huron to the Flint River, as the latter had far more pollutants. In other isolated cases, shaking caused by nearby construction was enough to temporarily shake loose protective coatings inside lead pipes and cause lead levels to spike thousands of times higher than the EPA's required action levels.

Almost all of America's remaining lead pipes are due to be replaced by the middle of the century, but there are currently few widespread calls to get the work underway, perhaps because digging up water lines is costly and inconvenient. The American Water Works Association esimated that completely replacing all lead pipes would cost a trillion dollars.

That's a lot of money, but it could be cash well spent. In a report published earlier this year, the University of Minnesota and the Minnesota Department of Health calculated that replacing lead pipes in the state could yield a large return on investment.

"This report estimates costs for removing the two most significant sources of lead to be between $1.52 billion and $4.12 billion over 20 years. Estimated benefits associated with removing lead from water include improvements in population mental acuity and IQ (and resulting increases in lifetime productivity, earnings and taxes paid). The projected range of benefits is $4.24 billion to $8.47 billion over 20 years, although there are a number of reasons to believe these benefits may be underestimated."

According to the World Health Organization, "There is no known level of lead exposure that is considered safe." As a cumulative toxicant, it can build up in the body over time.

Dispatching it from drinking water once and for all seems like a no brainer.