ST. PAUL, Minn. (AP) — A provision in the Senate immigration bill would make it mandatory for businesses to use E-Verify, a database that’s supposed to tell whether a potential hire is eligible to work in the U.S. But some Minnesota employers say the system is unreliable and burdensome.

They have a sympathetic ear in Sen. Al Franken. The Minnesota Democrat said the requirement could be difficult for small businesses including farms that hire immigrant workers.

The system is prone to misidentifying legal workers, Minnesota Public Radio reported Thursday (http://bit.ly/ZndI0J ). It has a false positive rate of about 0.7 percent.

“The system isn’t ready for prime time,” Franken told reporters during a conference call last week. “Big businesses have the HR departments to deal with these errors. But for a small business where your accountant is also your front desk clerk and your mechanic and maybe your spouse, these kinds of errors are going to be a huge problem.”

Franken is still considering how to protect small businesses from the mandate. One possibility is to make E-Verify a requirement only after the error rate drops below a certain level.

Some government contractors in Minnesota are required to use the program, but it’s not mandatory for all businesses that have contracts with the state.

Priya Outar, of St. Paul, is among those who have run into trouble with the system. As a child, she emigrated from Guyana and eventually became a citizen. Yet after graduating from law school, Outar has been repeatedly flagged by the system as ineligible to work.

“I have had to inform the Social Security Administration at least three times that I am a naturalized citizen. For a professional, and a lawyer at that, this situation is mostly just awkward and inconvenient; I cannot imagine the increased exposure to discrimination faced by individuals who do less specialized work,” Outar said.

The false positive rate is 20 times higher for foreign-born workers than it is for workers born here, according to a 2009 report commissioned by the Department of Homeland Security. That’s because immigrants, particularly Latinos, have more complicated names.

“Latinos often have a maternal and paternal last name, and there’s a lack of consistency in tracking both,” said John Keller, executive director of the Immigrant Law Center of Minnesota. “All of those will potentially lead to a non-authorization for employment even though the person is authorized to work.”

It’s a particular problem for Minnesota’s dairy industry. In Minnesota, about 45 percent of the non-family dairy employees are from Mexico, Guatemala and Ecuador, said Chuck Schwartau, who oversees livestock education programs for the University of Minnesota Extension in Rochester.

Jessica Vaughan, public policy director at the Center for Immigration Studies, said E-Verify has improved dramatically since it was launched as a pilot program in 1997. Giving small businesses a pass on E-Verify would mean a lot of ineligible workers could slip through the cracks, she said.