“If we lose them, it’s not going to be easy to replace them,” said Rick DiGeronimo, a vice president at Independence Excavating, a construction firm based in Cleveland that has several projects in the Washington area. About one-third of its workers have temporary protected status. “We’d struggle to finish some of our jobs because there aren’t workers of this quality out there,” he said.

Construction appealed to new arrivals from El Salvador because the jobs did not require special skills or knowledge of English, said Abel Núñez, the executive director of Carecen, a social services organization for Latino immigrants. “The construction industry was booming and these people wanted to work,” he said.

Temporary protected status does not provide a path to citizenship, but most of these workers never thought they would face deportation. They have been in the United States legally, for nearly two decades in many cases. Some have bought homes and cars and have settled into middle-class lives. Many have children who are American citizens.

There are nearly 46,000 people under the program in Maryland, Virginia and the District of Columbia, according to the Center for American Progress, a liberal group that opposes the Trump administration’s move. Over all, the Washington area is home to nearly 200,000 Salvadorans, the largest group of foreign-born residents in the region.

“It doesn’t make any sense,” said Alexander Garray, who has temporary protected status and spends his days 120 feet below Washington, boring a huge tunnel for water and sewage that will result in cleaner rivers in the region. “I pay taxes, I’ve never had a problem with the law, and I own a home. I don’t understand why they are trying to kick us out.”