A robust body of academic literature from the U.S. and Canada links lead in drinking water to increases in blood lead levels. Sources of lead contamination in drinking water include corrosion of lead service lines (LSLs), brass plumbing fixtures, and lead solder installed before Congress limited the use of lead in plumbing and pipes in 1986. Although indoor plumbing fixtures and lead solder can contribute to elevated lead levels in water, the research indicates that LSLs account for the largest share of lead in water. Importantly, observational studies show that U.S. residences with LSLs are at even greater risk if the techniques used to manage the corrosivity of water are not effective and lead from pipes leaches into a home’s water supply.
In the past, “corrosion control” has been the primary method for reducing lead in water in the United States. This technique involves treating water with chemicals, such as orthophosphates, that create a barrier between the pipes and the water in them or adjust the pH or hardness of water. While corrosion control has dramatically decreased water lead levels in the U.S., the various methods can differ substantially in effectiveness and corrosion control can never completely eliminate the risk of lead exposure that results from leaving lead pipes in the ground. For this reason, LSL replacement is viewed as the most reliable and effective method to reduce lead in drinking water.
When water systems remove LSLs, they must offer property owners the opportunity to replace their portion of the line at the same time. But because owners cannot be compelled to pay for replacement of their lines, the public portion is often all that gets updated. However, research shows that lead concentrations increase during and after such partial remediation, indicating that partial replacements—in which only one portion of a line is updated—are inadequate to protect children from exposure. For that reason, this website shows the expected costs and benefits of full LSL replacement, wherein both the homeowner and utility-owned portions of the lines are replaced. There are a variety of policy approaches to ensuring this full replacement takes place—examples such as Lansing, MI and Madison, WI.
The computations in this website therefore represent the costs and economic benefits of full LSL replacement in homes built before 1986 where children in the 2019 birth cohort would reside. Costs include the cost of testing the property for the presence of a LSL and the average cost of full LSL replacement. Benefits are derived from lower blood lead levels expected due to LSL replacement and the resulting lifetime impacts consisting of increased lifetime earnings, reduced health expenditures, decreased education spending, and a lower risk of mortality.