Michigan recently proposed changes to a drinking water safeguard known as the Lead and Copper Rule, which is supposed to help remove lead from drinking water. But it may not live up to this expectation because it allows water utilities to do what are called partial lead service line replacements.
To understand what a partial replacement is, it’s helpful to know how water is delivered to our homes. As the graphic below illustrates, water mains deliver water to the street then the water flows through service lines into our homes. In Michigan, roughly 500,000 houses are connected to the water main by lead service lines, which are a source of lead contamination for drinking water. Lead can be released from the pipes despite the use of chemicals that generally hold it in place. The only way to remove this source of lead contamination is to completely remove lead pipes from the ground.
In Michigan—and in most places around the country—water utilities require homeowners to cover the cost of replacing the portion of the pipe that runs from the property line to the home. If residents do not replace the pipe due to their inability to pay or as the result of ineffective utility education and outreach programs, then the utility will often replace only the portion of the pipe that runs from the water main in the street to the curb. The new section, which is typically copper, is then reconnected to the remaining old lead pipe that runs to the house.
So, what’s wrong with partial lead pipe replacements?
First, as the name suggests, a partial replacement leaves lead pipes in the ground. Because lead pipes are a source of lead contaminated drinking water, failure to remove the entire pipe leaves the source of lead contamination in place.
Second, a chemical reaction called galvanic corrosion can occur when two types of metal (lead and copper) are fused together, which can cause more corrosion of the lead pipe. This further increases the risk of lead-contaminated drinking water.
Studies have shown that partial lead pipe replacements can be problematic.
At best, they waste money because they do not reduce levels of lead in drinking water. The EPA’s Science Advisory Board noted that partial replacements “have not been shown to reliably reduce drinking water lead levels in the short term, ranging from days to months, and potentially even longer.” Further, there is no financial case to be made for partial lead pipe replacement. Instead, there are significant cost advantages to replacing the entire lead pipe when the construction crew is on site. Ratepayers should demand that water utilities stop this practice unless it’s a temporary repair during a water main break or other emergency.
At worst, partial replacements can substantially increase lead levels for months—or longer. According to the Centers for Disease Control and Prevention, partial replacements “may be linked to increased incidence of high blood levels in children.” The EPA’s Science Advisory Board noted that partial replacements are “frequently associated with short-term elevated drinking water lead levels for some period of time after replacement, suggesting the potential for harm, rather than benefit during that time period.” The Science Advisory Board found that, even while the lead levels might stabilize over time, they could remain at levels consistent with those prior to the partial replacement.
It’s also worth noting that the American Water Works Association, which is the industry association for 3,900 water utilities supplying roughly 80% of the nation’s drinking water, prioritized the removal of existing partial lead pipes in its November 2017 lead pipe replacement guidance. In fact, according to Paul Olson, AWWA’s senior manager of standards:
“The [AWWA] standard continually recommends avoiding partial replacement, if possible. It can cause more problems than it solves. You’re getting rid of some lead, but in the process, you’re disturbing the system and may be stirring up more lead than if you had just left the whole thing alone.”
The only way to protect public health is to remove the pipes, which is why we are calling for a ban on partial replacements and a mandate to replace the full lead pipe.
Unfortunately, however, these partial replacements could become more widespread under Michigan’s proposed Lead and Copper Rule. While the proposed rule’s stated goal is the removal of all lead pipes delivering water to homes, it contains significant loopholes that would allow water systems to accelerate partial replacements.
In the wake of the Flint Water Crisis, Michigan should become the model state by mandating full lead pipe replacement and calling for other improvements to the current proposal. The Michigan Department of Environmental Quality is taking comments on their suggested changes to the Lead and Copper Rule until March 21st. You can be part of the solution by submitting your comments in support of strong lead in drinking water protections.