To change the authorized depth for the project for navigation at Manistique Harbor, Michigan, and for other purposes.

Amends Federal law making appropriations for improvement of a harbor at Manistique Harbor, Michigan, to permit installation of a sand and stone cap over sediments affected by polychlorinated biphenyls in accordance with an administrative order of the Environmental Protection Agency. Regulates project depth. Requires that the project continue to be maintained as a harbor of refuge.