Here’s what worries engineers the most about U.S. infrastructure
Water and sewer systems built in the mid-19th century weren't meant to handle the demands of modern cities, and many bridges and levees have aged well past their intended lifespan.
Christine Kirchhoff’s family were preparing to move into a new house when Hurricane Harvey hit Houston in 2017. Then the massive storm dumped 50 inches of rain on the area in just a few days, leaving two nearby reservoirs so full that their operators were forced to open the floodgates. Kirchhoff’s family had to be evacuated by boat. Both their original and new houses were inundated.
As an associate professor of civil and environmental engineering at Pennsylvania State University, Kirchhoff spent a lot of time thinking about water even before it swallowed her family’s livelihood. She is part of the legion of professionals behind the complex, often invisible systems that support American life: dams, roads, the electric grid, and much more.
For the last 25 years, the American Society of Civil Engineers has been sounding the alarm on the state of that infrastructure across the country. In their most recent assessment, for example, transit scored a D- and hazardous waste a D+. It’s an expensive problem to ignore. The ASCE estimates current infrastructure conditions cost the average family $3,300 a year. “Everyone is paying whether they know it or not,” Kirchhoff says.
Train derailments, highway and bridge collapses, and dam failures have become increasingly common. But which areas are civil engineers most concerned could cause imminent catastrophe, and what can we do about it? Kirchhoff and other infrastructure experts weigh in.
Water contamination crises are already here
The engineers we talked to agreed: our water systems are in trouble. Both those that protect us from water as a hazard (stormwater, dams, levees, bridges) and those that help us manage water as a resource (drinking water, wastewater, inland waterways) are in grim shape.
The United States’ 2.2-million-mile drinking water and 800,000-mile sewer system was developed in part in response to the widespread waterborne diseases of the mid nineteenth century, Kirchhoff says. Maintenance has lagged woefully behind since then; some older areas, including some cities in the northeast, still use century-old wooden pipes. And many more of our pipes nationwide are still made of lead.
A water system designed for yesterday’s climate and to filter yesterday’s contaminants is especially problematic in a world of increasing demand, fiercer and more frequent storms, and “forever” chemicals. The result: boil orders, water main breaks, and sewer overflow, plus 15 percent of our water treatment plants working at or over capacity. These issues, combined with the toxicity of lead pipes, lead to water crises like the one that continues to plague Flint, Michigan.
Amlan Mukherjee, the director of sustainability focusing on infrastructure at WAP Sustainability Consulting, recommends focusing on these pipes—swapping lead for PVC or other materials and fixing the leaks that spill some 6 billion gallons of treated water a day—as one high priority fix.
Our coastline is also dotted with facilities storing hazardous oil and other chemical waste cocooned in donut-shaped earthen structures, adds Bilal Ayyub, a professor of civil and environmental engineering at the University of Maryland at College Park—structures that, he notes, could be made of concrete. Because of soil’s vulnerabilities, he worries that dramatic rainfall or a storm surge could destroy these structures, resulting in a release of toxic chemicals “bigger than the Exxon Valdez spill by orders of magnitude.”
His worst-case scenario has already happened at least once, when floodwaters from Hurricane Harvey ate through the earthen container at the San Jacinto River Waste Pits, releasing noxious waste into a nearby river.
Physical collapse is happening now
Meanwhile, the number of high-hazard-potential dams in the United States now tops 15,000. Many were built during or before the WWII era and have been widely neglected since then. And when it comes to bridges, “there are cautionary tales all over,” says Maria Lehman, president of ASCE and vice chair of the Biden Administration’s National Infrastructure Advisory Council. “Every county in the country has a list of bridges that, if they had money, they would replace tomorrow.”
Our 617,000 bridges include not just those spanning mighty rivers but also every highway overpass and minor link across a stream—and close to one tenth of them are significantly compromised. “If you have to think in terms of catastrophe, we’re already there,” Mukherjee says. In 2007, the collapse of an I-35W bridge in Minnesota killed 13 people and injured 145. More recently, a six-lane bridge over the Mississippi was closed for three months in 2021, disrupting interstate travel and shipping because an inspector missed a significant crack. Americans drive 178 million trips on structurally deficient bridges each day.
Yet the US spends only 1.5-2.5 percent of its GDP on infrastructure, proportionately less than half of what the European Union spends, Lehman says. This long-term lack of funding has run out the clock on many solutions. Many of our bridges were built to last 30-50 years, but nearly half are at least half a century old. The average age of our levees is also 50; our dams average 57.
Now, extreme weather is intensifying just as structures fail. We’ve already seen consequences in the devastation of Hurricane Katrina in 2005, for example, when collapsing levees inundated 80 percent of New Orleans, killing hundreds, or in the failure of an under-inspected dam in Edenville, Michigan, which flooded the region and destroyed thousands of homes in 2020. The trend is set to continue: after Superstorm Sandy engulfed New York City transit, Ayyub helped study similar risks in Washington, D.C and Shanghai. His models showed widespread flooding that could swamp D.C. metro stations and in severe cases even reach “the backyard of the White House.”
The future of U.S. infrastructure
Mukherjee is optimistic about the use of new technology to solve some of these issues, though adoption has been slow. Drones can provide human inspectors with up-close views of areas they can’t reach themselves and reduce chance of human error; a drone on an unrelated project captured footage of the Mississippi bridge crack two years before its discovery.
Ayyub has also worked with North American freight railroads to find weak links using computer modeling, combing through thousands of stations to “identify exactly which point if it fails will have the biggest impact,” he says. Why not do the same with our power grid and waterways?
One piece of good news: in 2021, Congress passed the Bipartisan Infrastructure Law, which provides $1.2 trillion over five years for the ailing systems that help American society run, the largest federal investment in US history. It was a major victory. “Every president for the last eight presidents said we should spend a lot of money—like a trillion dollars—on infrastructure, and none of them delivered,” Lehman says.
Unless it is renewed regularly, though, this funding will barely stop the bleeding. And meanwhile, across the country, families like Kirchhoff’s (who after a difficult year were able to rebuild both the destroyed houses) struggle to recover from a relentless march of disasters, many of them preventable. It’s time for the US to learn the lessons drawn from of a century of neglect, Lehman argues, and begin maintaining the systems that makes so much of American life possible while they’re still in working condition.
“If you have a leak in your roof, you go up there, find it, replace the shingles, put on a little tar” she says. “If you let it go, it’s not going to be a little fix: it’s going to be a replacement.”
You May Also Like
Go Further
Animals
- Ancient dolphins thrive in one of Italy's most polluted citiesAncient dolphins thrive in one of Italy's most polluted cities
- This bug can get 26 times bigger than its smallest specimenThis bug can get 26 times bigger than its smallest specimen
- One of Earth’s biggest freshwater fish is bouncing backOne of Earth’s biggest freshwater fish is bouncing back
Environment
- How pulling carbon out of the ocean may help remove it from the airHow pulling carbon out of the ocean may help remove it from the air
- Can Paris clean up the Seine in time for the Olympics?Can Paris clean up the Seine in time for the Olympics?
- What fuel made from the sun could do for the planetWhat fuel made from the sun could do for the planet
- Mexico City is running out of water—are these cities next?Mexico City is running out of water—are these cities next?
- These photos show what happens to coral reefs in a warming worldThese photos show what happens to coral reefs in a warming world
History & Culture
- Meet the Louisiana legend who inspired Princess TianaMeet the Louisiana legend who inspired Princess Tiana
- Vivid colors of ancient art uncovered in Egypt's Temple of EsnaVivid colors of ancient art uncovered in Egypt's Temple of Esna
- Here's the real reason the U.S. doesn't use the metric systemHere's the real reason the U.S. doesn't use the metric system
- Before the Great Migration, there was the Great ExodusBefore the Great Migration, there was the Great Exodus
- The perfect storm that led to the Jonestown massacreThe perfect storm that led to the Jonestown massacre
Science
- This is the biggest health challenge women face in their 40sThis is the biggest health challenge women face in their 40s
- How a rare, ‘once-in-20-years’ aurora formed at the North PoleHow a rare, ‘once-in-20-years’ aurora formed at the North Pole
- Why doctors don't know much about uterine fibroidsWhy doctors don't know much about uterine fibroids
- Why it’s never too late to learn a language as an adultWhy it’s never too late to learn a language as an adult
Travel
- Everything to know about Zion National Park
- Travel
- Destination Guide
Everything to know about Zion National Park - Join this 147-year-old club to swim in San Francisco BayJoin this 147-year-old club to swim in San Francisco Bay
- Discover the bounty of super-size farm shops in this UK regionDiscover the bounty of super-size farm shops in this UK region
- How to make summer pudding, a classic British dessertHow to make summer pudding, a classic British dessert
- A spotlight on Ecuador's age-old relationship with the sun
- Paid Content
A spotlight on Ecuador's age-old relationship with the sun - 6 alternatives to the most popular national park lodges6 alternatives to the most popular national park lodges