Reaction to the solution: lead exposure following partial service line replacement.

Abstract

The safety of a commonly used construction technique for getting the lead out of drinking water—digging up old lead water pipes (“service lines”) and replacing a portion with new copper pipe—has been debated for many years. At best, critics charge, this technique may waste millions of dollars by failing to reduce levels of lead in drinking water. At worst, the partial replacement technique can backfire and substantially increase lead levels for months or longer. The Centers for Disease Control and Prevention (CDC) recently warned public health officials that new agency findings suggest partial replacement of lead service lines may be linked to an increased incidence of high blood lead levels in children. Some drinking water experts are now saying the CDC and the U.S. Environmental Protection Agency (EPA) should consider jointly recommending a moratorium on partial service line replacement based on this new information. To understand the potential impact of partial lead service line replacement, Virginia Tech environmental engineer Marc Edwards suggests an analogy with lead paint. “We all understand that lead paint becomes a hazard if it’s disturbed,” he says. “Our research indicates that doing a partial [lead] service line replacement is analogous to creating a source of lead dust right in your home, where it is very accessible by children. The ‘dust’ in this case, which is in the form of lead rust on the pipe, builds up continuously over time. If and when it comes off [the pipe], the amount of lead [in drinking water] can vastly exceed health standards.” He adds, “But instead of realizing this is a potential hazard, homeowners have a false sense of security, because they are told that partial service line replacements are being conducted to improve the situation.” “There is no doubt that partial lead service line replacements can result in significantly elevated levels of lead in tap water and that this contamination can continue for weeks and months, particularly in situations where [drinking water] corrosion control is not optimized,” says EPA chemist Michael Schock. “Why and where these high levels occur is still the topic of research, but their occurrence is fact.”