Academic researchers at the University of Virginia (Charlottesville, Virginia) are urging water system managers across the United States to consider new research on corrosion inhibitors to help prevent future problems similar to those that occurred in Flint, Michigan.
For instance, the team (Figure 2) notes that adding orthophosphate to treated drinking water can cause protective coatings to form inside pipes, thereby preventing corrosion and controlling lead concentrations at very low levels. This makes it more difficult for harmful lead to leach out and contaminate drinking water—which happened in Flint.
“This is a real problem that is never going to go away as long as lead pipe is in service—and it could have been avoided,” says Veronica Rafla, a graduate student in materials science at the school. “Before we started this, we didn’t how little phosphate was needed to solve the problem. It is shocking. A small amount can make a huge difference. A little gives an immense benefit.”
Using Flint as a Case Study
In 2014, the city of Flint switched its water supply from Lake Huron to the Flint River as a cost-cutting measure. The Flint River water contained higher levels of chloride, making it more corrosive than the lake water. In turn, this led to an increased release of lead from the system’s aging water pipes.
At the same time, as part of a plan to save money, local water system managers were not treating the water with orthophosphate.
John Scully, FNACE—chair of the Materials Science and Engineering Department at Virginia and co-director of the school’s Center for Electrochemical Science and Engineering—worked over the summer with undergraduate and graduate students to further explore Flint’s problems.
Scully says the team’s research found that just a small amount of orthophosphate was needed to treat the lead-leaching problem. With experiments still ongoing, Scully says he is not yet ready to declare an exact level. However, he notes that in recent months, Flint officials have indeed resumed the treatment process using orthophosphate.
“Sometimes problems can be overlooked, and it doesn’t take much to solve them,” says Kateryna Gusieva, a Ukrainian post-doctoral research associate working in materials science at Virginia.
Aging U.S. Infrastructure
Scully’s group is researching the problem with an eye toward future U.S. water system problems, since aging water infrastructure could soon create more problems throughout the country, he says.
According to Scully, most lead water pipes were installed in U.S. municipal systems from the early 1800s into the 1900s, based on the belief that lead was more malleable and less corrosive than iron pipes, and also lasted longer than cast iron.
“People then did not understand that lead is a poison,” Scully says.
Over time, many U.S. officials began to recognize the health problems of leaching lead from pipes and proposed ways of dealing with it, such as reducing the acceptable levels of lead in water.
“As the years went by, the allowable lead levels got lower,” Scully says.
Nonetheless, because many of the pipes are buried underground and not visible, addressing the corrosion in water pipes remains a challenging process. Scully notes that in many cases, corrosion maintenance programs have been deferred—leading to more expensive remediation and replacement issues later in the system’s lifecycle.
As a result, Scully and the student researchers (Figure 2) are hoping to raise even more awareness in the aftermath of what happened in Flint.
“I have been in the corrosion business for eight years, and I think this is my contribution to the real world,” Gusieva says. “Growing up, I never thought I would make a difference. Because in my country, the politics are difficult—but this work is helping people in a broader sense.”
One potential solution offered by many U.S. system operators has been to replace the outdated lead piping, Scully says. While many systems still use lead pipe, some operators have replaced parts of their lead piping with copper replacement tubing.
However, Scully warns that the use of the copper replacement tubing may accelerate the corrosion of the remaining lead sections of the pipe due to galvanic corrosion. Scully says it is important that researchers solve problems such as this, since the water system operators are typically not corrosion experts.
“If you don’t know something, you ask the experts,” says Jacob Wright, who graduated from Virginia in May with an engineering degree and continued to work with Scully’s team over the summer. “Sometimes the half-solutions often implemented can create their own problems.”
The work by Scully and his team is largely due to personal commitment to the cause. Scully notes that he has received no funding for this research thus far, adding that students are moonlighting from their own research projects in other areas.
“The project will likely never end, in that we will continue in some residual or low-level way because we did this in our spare time anyway,” Scully says. “It was unfunded. All my students are funded on something else—no one is coming in yet with exclusively dedicated lead corrosion funding.”
Scully says he may apply to the National Science Foundation (Arlington, Virginia) for future funding, thereby enabling his team to further examine issues such as what happens when an inhibitor chemical is used, discontinued, and then reintroduced.
“It is of no direct use at Flint, as long as the restored orthophosphate treatment works and/or the water supply has been switched to a less-corrosive source,” Scully says. “But maybe if we show that chemical treatment is inadequate once you go through a period of ‘no inhibitor use’ in a corrosive water situation, that would be a piece of information that would be worthwhile to share and might have practical impact.”
Scully also serves as the technical editor-in-chief of NACE International’s CORROSION research journal. After the problems in Flint, Scully notes that CORROSION granted free, open-access status on its material related to lead corrosion in water pipes, as part of an effort to warn the public of its dangers while also offering potential solutions to system operators.
In the case of his team’s latest work, Scully says that experiments are continuing to roll in, with results analyzed, rerun, and double-checked.
“No answer is better than the wrong answer, by order of magnitude,” Scully says.
But in the near future, the goal is to publish the team’s specific findings.
“The research we do will be eventually reported out in an archival journal,” Scully says. “We are disseminating knowledge that hopefully trickles down to the general public for the benefit of all. It is also helpful to the students’ careers.”
1 M. Kelly, “Professor, Students Examine Lead Corrosion In Pipes, In Light Of Flint’s Problem,” University of Virginia News Release, 09/27/2016, https://news.virginia.edu/content/professor-students-examine-lead-corrosion-pipes-light-flints-problem (October 17, 2016).