Replacement of the United States six to ten million lead service lines is complicated by what the proper replacement pipe material would be, such as copper, iron, steel or plastic. 35 percent of US utilities’ spending on drinking water distribution will go towards plastic piping, but the potential health risks from plastic material is unclear. Recent studies show plastic pipes can cause contamination through the plastic material leaching or through permeation, where pollutants can seep from the outside environment, through the plastic and into the water. Additional considerations are that plastic pipes can be more easily damaged by wildfires.
Although these concerns about PVC pipes in particular are disputed by the executive director of the Uni-Bell PVC Pipe Association and the NSF’s position doesn’t discourage the use of plastic pipes in general, it recommends that consumers with concerns focus on specific types of piping which could be vulnerable to contamination. Despite these positions, there is still data showing that leaching and permeation can occur. Studies performed on PEX (cross-linked polyethylene) pipes have shown that in addition to allowing chemicals to pass through, microbial growth can be higher than otherwise. Considering that there are multiple potential negative effects from plastic piping, more studies should be performed, in addition to studies on pipes made of metals like copper and steel. Due to the challenges and time required to replace lead service lines, testing will continue to be important for some time into the future.