Some construction companies in North Dakota are paying workers under the table and skipping out on worker benefits to avoid paying taxes, according to local union advocates and data analysis from the University of California Berkeley Labor Center that finds the construction industry may no longer be able to offer workers “family-supporting jobs.”

Isaac Prieto said he came to North Dakota for higher wages, but eventually discovered his drywall employer was purposefully denying him benefits and even claiming more compensation than he received in order to make illegal payments to other workers.

“I was working 70, 80 hours a week,” he said. “I never get paid overtime. And he has a lot of people who do not have papers. Every year I would get like $4,000 or $5,000 extra on my paycheck that I did not make. I guess they thought I was not gonna do my taxes.”

Even if workers receive their full pay and benefits, the report said, their compensation may not be enough. It suggested low construction wages force more than one-third of U.S. workers onto public-assistance programs, at a taxpayer cost of nearly $28 billion per year.

Adam Duininck, director of government affairs for the North Central States Regional Council of Carpenters, a union that helps workers negotiate with companies and state lawmakers, said holding companies accountable helps more than just construction workers.

“Construction industry tax fraud affects everybody,” he said. “You have this workforce that’s not being paid. There’s payroll taxes [that] aren’t paid on them, unemployment insurance, health care that they may use. It ends up costing us as taxpayers. We have to pick up the tab.”

The council represents nearly 27,000 union members and their families in the Dakotas, Iowa, Minnesota, Nebraska, and Wisconsin.

The industry had been known for allowing workers without a college education to find well-paid jobs. Prieto said he became a union member to prepare for the future.

“I want to retire someday, get my full 401(k),” he said. “I don’t want to owe the government money. I want to know everything is legal, everything’s taken care of. I don’t want to become an old man, and next thing you know, I did not put a lot of money into my retirement.”