A landmark federal commitment to fund the elimination of a toxic national legacy—lead drinking water pipes—promises to improve the public health outlook for millions of people across the U.S. But it also presents communities with a thorny choice between replacement pipes made of well-studied metals such as copper, steel or iron and more affordable but less-studied pipes made of plastic.
Service lines are commonly made of copper, iron, steel or one of several types of polyethylene or polyvinyl chloride , according to various sources. In the next decade up to 35 percent of U.S. utilities’ spending on drinking water distribution will go toward plastic pipes, says Bluefield Research, a firm that provides analyses of global water markets.
Some organizations associated with the plastic pipes industry are skeptical or dismissive of findings that link these pipes with potential drinking water quality and health concerns. Bruce Hollands, executive director of the Uni-Bell PVC Pipe Association, points to a 2015 environmental product declaration that followed an assessment of seven PVC water and sewer pipe products by the International Organization of Standardization , a voluntary, nongovernmental standards organization.
Permeation of metal pipes is “extremely rare,” says Edwards, who in 2015 pinned down the cause of high lead levels amid Flint, Mich.’s water crisis. In contrast, gasoline and solvents can permeate polyethylene pipes, and pure benzene and other dangerous organic compounds also permeate PVC pipe without rubber gaskets , a Water Research Foundation report states.
But the characteristics of the study’s two individual water systems varied by water source, disinfectant used and average pH, among other factors. Such variations are unavoidable across water systems. “Plastic pipe can leach TOC, but this can be addressed through quality control measures such as proper testing and certification,” Gurian says. “Engineering is about managing risks and making tradeoffs.
“When you have so many people—so many organizations, especially—when they agree..., shouldn’t you take notice ...' I'm disappointed that *Scientific* American reporting ultimately resorts to 'popularity' of opinion, rather than evaluating the actual *science* in the issue.
So then offer a solution. Because copper isn't free from harm either, especially with lead solder joints. PVC contains chemicals that can be problematic. Galvanized pipe can lead to sterility in men. Glass isn't going to work because it's breakable. So what is the answer?