President Biden aims to replace all lead service lines in the United States — a long overdue undertaking to resolve a legacy of contamination. His initial American Jobs Plan set out to replace all lead lines within 10 years, with an estimated price tag of $45 billion. If enacted, pending infrastructure legislation would provide a down payment of $15 billion for the effort.

According to the White House, lead pipes run through an estimated 6 to 10 million homes, plus another 400,000 schools and child care centers. Lead exposure impairs neural development in young children and causes greater risk of kidney failure, stroke, and other health conditions. Disproportionately affecting low-income neighborhoods and communities of color, lead poses both a major public health risk and environmental justice issue.

Although replacement of lead service lines receives bipartisan support, upgrading the country’s aging infrastructure is no easy feat. A lack of data and mapping of old lines means we may not always know exactly how many lead pipes there are — and how much replacing all of them will cost. Furthermore, public water service lines only extend to the edge of private properties, meaning many homeowners own, and are responsible for, a portion of these lead pipes.

Navigating this complex web of policy, infrastructure, and funding will require collaboration between all affected stakeholders: governments, water utilities, households, and more. We ask experts from a range of backgrounds to consider: what is the best way to rapidly replace the country’s lead service lines? What should achieving 100 percent replacement look like in terms of strategy, timing, and the amount and structure of funding? And in achieving all of this, how can we ensure that the people most at risk are prioritized?

Since the initial wave of infrastructure investment in the 1970s and 1980s, many municipalities have not seen that effort matched. Perhaps enabled by a lack of taxpayer engagement (except during service interruptions), as well as a lack of knowledge regarding how these services are provided and what they actually cost, inadequate investment in our infrastructure seems likely to continue, especially where we are struggling to pay for other critical needs.

Even where water and sewer utility rates are far lower than necessary to properly fund infrastructure needs, ratepayers often complain about their utility bills. Thus, our thirst for aggressively marketed brand-name bottled water seems inexplicable. Not counting the related cost of plastic waste, folks who get their water at the supermarket may pay about 300 times the rate of tap water.

As confounding is our pervasive reluctance to pursue effective conservation measures. Municipalities across the country are strained by unnecessary potable water demand resulting from customers’ leaking pipes and faucets, older high-capacity fixtures, and uncontrolled lawn irrigation, adding agricultural chemicals to the pollutant load for wastewater treatment facilities receiving the irrigation runoff. And, where conservation is yet an untapped resource, municipal water rates may remain upside down — rewarding heavy users by charging them less per gallon.

Infrastructure issues are magnified for rural towns with their small tax base. These localities likely constructed their drinking water and wastewater facilities over forty years ago and may have trouble even maintaining their aging facilities. Facing ever-tightening regulatory standards applied to ever-older infrastructure, these towns often experience service interruptions as their facilities become more and more vulnerable to catastrophic failure.

Facilities designed long ago often face significant changes in drinking water demand patterns and wastewater generation. Of course, all the treated drinking water may not actually be distributed to customers, nor may all the wastewater collected actually find its way to the wastewater treatment plant. The amount of drinking water lost from distribution line leaks and breaks can be shocking, while wastewater collection lines become occluded and lift stations fail, all adding significantly to the total cost shouldered by taxpayers.

Also, pollutant loadings may have increased in sources of drinking water and wastewater receiving streams, posing treatment challenges for these older facilities, particularly given more stringent regulatory performance requirements. These issues are challenging on a normal day. Then there are major line breaks, simultaneous equipment failures, high-demand holiday weekends, major storms, and for coastal facilities, storm surge, and sea-level rise.

Finally, older facilities were not designed to treat recently recognized pollutants, which could require facility upgrades all by themselves. For their drinking water source, small towns face increasing pressure from source water that can be impacted by agricultural operations, which may contribute escalating concentrations of nitrates, blue-green algae, and other pollutants. Small towns adjacent to larger municipalities may rely on source water impacted by urban development.

Groundwater in urban areas is vulnerable to contaminants associated with commercial and industrial activities such as petroleum sales or dry cleaning. Also, emerging contaminants including 1,4-Dioxane and per- and poly-fluoroalkyl substances are tied to many urban sources, including land application of municipal wastewater treatment plant sludge. Even if these smaller facilities are not actually down-gradient from an urban area, continued operation of public water supply wells can alter the normal groundwater flow direction, pulling ubiquitous urban groundwater contaminants into nearby well fields. Small towns adjacent to larger municipalities may also find surface waters impacted by discharges from the larger municipalities’ wastewater treatment plants, as well as from urban stormwater runoff.

The combined effect of all these issues on facility compliance and general infrastructure performance is foreseeable: our currently outdated and past-end-of-life infrastructure is often simply not up to the task. But we can be smarter about design and about our demands. And we must be committed to investing in our infrastructure, however that investment may be funded. Perhaps more federal funds will be available, and perhaps public-private partnerships are the key. But a commitment to smart conservation measures and meeting necessary costs are certainly first steps.