After months of negotiation and debate, the U.S. House of Representatives could be poised to pass a two-part legislative package aimed at overhauling the country’s notoriously aging infrastructure. But House Democrats (who hold a majority in the chamber) have yet to reach an agreement on one part: a bill that focuses on social programs and fighting climate change. This means the other part—the bipartisan Infrastructure Investment and Jobs Act, or IIJA—remains in limbo. The IIJA’s $1 trillion investment, which includes $550 billion in new federal spending, sounds hefty—but many experts say it is only enough to merely get started on addressing the problem.

“You can’t build a healthy economy on a crumbling infrastructure,” says Maria Lehman, president-elect of the American Society of Civil Engineers. Every four years this professional organization publishes a report card on U.S. utilities, issuing letter grades in 17 categories such as roads, internet access and drinking water—and the grades rarely rise above a D. “We’ve had many, many, many decades of taking our infrastructure for granted,” Lehman points out. “And it’s all coming due at the same time.” Scientific American spoke with Lehman about what’s broken, whether the IIJA’s $1 trillion investment can fix it, and what happens if the federal government fails to invest in infrastructure.

[An edited transcript of the interview follows.]

What does the report card indicate about the state of the nation’s infrastructure?

Our infrastructure, in general, is not in a midlife crisis; it’s in an old-age crisis. Most of our infrastructure is old and tired, and was not built for today’s needs. If you look at roads and bridges, there’s more traffic. There’s heavier trucks. All those things weren’t imagined 30, 40, 80 years ago when we built it. This report card in 2021 is the first time that the [grade] was out of the D range, the first time we’ve had a cumulative grade at C minus. And that really has more to do with state and local governments stepping up, because the federal government really hasn’t changed or increased their formulas for several decades; it certainly has not even kept up with inflation. A lot of states and locals have done things like had bond issuances for water and wastewater, or raised gas taxes to be able to fund more than they were before. But it still comes down to the fact that you really need a strong federal partner.

Which categories seem to be in the worst shape?

Eleven out of our 17 categories got a D. That’s horrible. I mean, aviation, dams, hazardous waste, inland waterways, levees, public parks, roads, schools, stormwater, transit and wastewater, all got scores of D. Transit was the lowest grade, a D minus; rail was the highest with a B. The class I railroads have made a lot of investment over the last decade to improve the rails, to improve crossing. Positive train control has been improved in the country to make sure we’re at the latest and greatest safety technology.

The other one that I think did really well, in general, is ports. Most of them are either public-private partnerships, public authorities or private, and we have seen so much more imports into the country in so much freight, that the ports themselves have done really well. But everything else has got issues.

For me personally, the one that I think is the most important is the lead pipes in [the category of drinking] water. The reason for that is lead is one of three heavy metals that, once you have it in your body, it never leaves. So those children in underrepresented, underserved communities that have those lead service lines, the lead poisoning they get—they’re never getting out of that. They’re impacted for life. So, from a public health and safety standpoint, the investment in getting rid of those lead lines, on the water system side, is the most important thing we ought to do.

How does the new infrastructure bill help?

Part of what we do with the report card is what we call the Failure to Act economic reports, where we hire an outside economist to take a look at all the data and all the metrics that we pulled together, and then look at what the impact is. We do it in various classes of infrastructure, so there’s a road and bridge one, there’s water and wastewater, there’s the electric grid. The idea of the Failure to Act report is, “If we do nothing, what is the impact?” The gap between all funding sources—local, state, federal and private—versus the need is $2.6 trillion for the next 10 years. So, if you look at that [over], say, five years, that’s $1.3 trillion. The infrastructure bill itself is supplementing that by $550 billion. So, it’s about half what the gap is. The bill, as it stands right now, is more than we’ve ever invested, and in some categories of infrastructure, it’s as much as double. But it’s still overall not enough. It’s still not beating the gap of what the needs are out there.

If you look at the bill, the biggest impact that I see is in bridges. Because in bridges, I think it takes up about three quarters of the gap. In highways it’s much less, because we have over a trillion in road bridge backlog—out of that $2.6 trillion, $1.1 trillion is in roads and bridges—and roads are expensive to reconstruct.

What is the impact of inaction?

We talked about those Failure to Act reports. [In addition to] identifying the gaps, it basically said that the average family is going to lose $3,300 a year based on infrastructure [failures]. For example, you have a “boil water” alert, or you have to buy water. Or your power’s out, and you have to go get a generator and replace a refrigerator full of food that spoiled and that nobody’s going to pay for. You hit a pothole, and not only did you blow the tire but you dented the rim or you cracked the axle. The lack of infrastructure investment is already impacting families at over $3,000 a year. It’s a one-on-one cost, and so there isn’t this huge outcry—but a lot less than that per family would fix it. So, we really need to make the investment. You know, for highways alone, it’s $1,000 a year [lost] on average across the U.S. just sitting in traffic, and people not going back to transit or commuter rail has caused car-mageddon in a lot of cities. People feel safer in their cars [because of COVID]; they’re not going back to transit. And that’s causing a lot of issues, and more wear and tear on the road, and more costs.

Does the bill fund any ambitious new projects? Anything that would create something new rather than fixing what is old?

The construction industry, as a whole, has not seen the disruption that almost everything else has. We still use steel and concrete, and have for a very long time. But the thing that’s exciting to me is we’ve underfunded research and development for a long time as a country, and so one of the things in the IIJA is that there’s $50 billion in resilience projects that make us more climate-resilient. So we think about building it back better, making something that’s going to be there. There’s $7 billion towards electric vehicles. And there’s research and development money that is sprinkled in through a lot of the different items—that can [help] come up with what the next great thing is going to be.