Federal officials worry that the electrified barrier might be dangerous for the crews of barges on the Chicago Sanitary and Ship Canal.
The barrier was completed two years ago but has yet to be activated, The Milwaukee Journal Sentinel reported.
The carp, imported to Arkansas 30 years ago, escaped into the Mississippi River system and multiplied quickly. Experts say they are within 45 miles of the Great Lakes and the only thing in their way is a smaller electric barrier that was not intended to be a permanent solution.
Gov. Jim Doyle wrote Homeland Security Secretary Michael Chertoff and Defense Secretary Robert Gates on behalf of the Council of Great Lakes Governors, asking for a "detailed work plan and timeline" on the completion of testing.