The city of Lowell, Mass., has more than 100 bridges, carrying tens of thousands of vehicles a day over historic canals and the mighty Merrimack River that once fueled its industrial-era factories and textile mills.

City officials and residents have long complained that the aging steel and concrete structures — many built decades ago — are deteriorating and at risk of failure. Projects to overhaul the bridges have been pitched by city planners over the years but shelved due a lack of funding.

Now several of those bridges are set for major repairs after getting a $21.4 million federal grant, awarded in August. The money comes from the Infrastructure Investment and Jobs Act, a $1.2 trillion spending bill signed by President Joe Biden in 2021.

The act, also referred to as the Bipartisan Infrastructure Law, passed the U.S. Senate by a bipartisan vote of 69-30 in August 2021, followed in November of that year with passage in the U.S. House on a vote of 228-206. The vote by the Massachusetts congressional delegation was mostly along party lines, with the exception of Democratic U.S. Rep. Ayanna Pressley, who voted against it.

Supporters of the infrastructure law, like U.S. Rep. Lori Trahan, a Westford Democrat, have touted it as a “once-in-a-generation” investment that will have a measurable impact on people’s everyday lives.

“The Bipartisan Infrastructure Law is finally helping to transform cities like Lowell that have long been left to fend for themselves,” she said.

Pressley said at the time of the House vote that she didn’t support the law because the companion Build Back Better Act, which would have pumped federal dollars into the care industry, housing, climate change initiatives and more, was divided into smaller, narrower spending bills.

“I refuse to choose between the livelihoods of the union workers who build our highways and bridges, and the childcare and health care workers who care for our children, elderly and disabled loved ones,” she said in a statement. “I refuse to choose between our crumbling roads, bridges, public transit system, and our crumbling housing stock.”

Overall, Massachusetts stands to receive more than $9.3 billion from the infrastructure law over the next five years, including at least $4.2 billion for roadway upgrades and $1.1 billion for bridge repairs, according to the Biden administration.

At least $1.1 billion will be directed to improving water and sewer infrastructure and address outfalls that spew sewage into the Merrimack River.

The state will also get $2.5 billion for upgrades on its public transit system. Other funding would be devoted to airport upgrades and incentives for drivers to switch to electric vehicles.

It’s also slated to get $147 million to help expand high-speed broadband internet service to underserved regions of the state.

But the state is also chasing after $2.5 billion in competitive grants made available through the infrastructure law for local governments to fix potholes and crumbling bridges, upgrade water and sewer systems and other needs.

In October, the U.S. Department of Transportation said it is sending $1 billion to the state to support a dozen programs that fund infrastructure upgrades, including roads, bridges and tunnels, carbon emission reduction efforts, highway safety improvements and workforce development.

The prospect of billions of dollars in federal funding to jumpstart public work projects in Massachusetts has construction trades preparing to turn shovels and break ground.

“We’re really excited about it,” said Frank Callahan, president of the Massachusetts Building Trades Council, which represents union construction workers. “We’ve been working the trades, expanding apprenticeship programs, and working with cities and towns to identify projects.”