Advocates who want to do something about illegal immigration in Nebraska have become enthused about the national pilot project E-Verify, which is intended to give employers a quick answer on an employee’s immigration status.

A word of caution is in order.

E-Verify is no panacea.

The system may be worth trying, but authorities should have a clear view of the system’s limitations.

Its problems include a significant error rate. The system is ineffective in detecting fraudulent documents. There are also questions about how much more work the system can handle because it is slated for more than double its federal responsibilities next year.

One recommendation to expand local use of E-Verify came this month from a mayoral task force in Fremont that has been exploring immigration issues.

Also suggesting expanded use of the system is Sen. Brad Ashford of Omaha, head of the Legislature’s Judiciary Committee, who has held meetings in Grand Island, North Platte, Scottsbluff, Lexington and Schuyler.

One problem with E-Verify is that it relies on the Social Security database. The government itself acknowledges that the database has an error rate of 4.1 percent. That equates to about 17 million U.S. residents.

Employees who are given a “tentative nonconfirmation” have eight days to eliminate the discrepancy. Many of the errors can be cleared up in a matter of days, according to a review of 1,000 new hires conducted by Homeland Security, but some are more problematic.

Some experts also believe that the error rate is higher among naturalized citizens. It would be particularly distressing if the E-Verify program caused trouble for new citizens who have done their best to comply with the rules.

A Government Accountability Office report in June also noted that E-Verify “cannot yet fully address identity fraud issues, for example when employees present genuine documents that may be stolen,” although steps are under way to improve its effectiveness.

The E-Verify system is set to assume a huge new workload on Jan. 15 when federal contractors and subcontractors will begin using the system under an executive order issued by President George W. Bush.

The government estimates 168,000 employers will have to screen 3.8 million employees in 2009. This year, 70,000 employers used the system. The Information Technology Association of America is worried it will not be able to manage larger volumes.

Given that the E-Verify System is still in its early days, officials in Nebraska should be leery about using it as the basis for levying stiff penalties. Both employees and employers should be given adequate leeway in case the system does not live up to expectations.