DETROIT - A report written in response to a massive oil spill from an Enbridge pipeline into a Michigan river concludes U.S. federal laws are inadequate to protect the Great Lakes basin from oil pollution and states should fill the gaps.

The report released Monday by the National Wildlife Federation and University of Michigan Law School finds there's no review of long-term risks related to oil-pipeline routing decisions. It says states have a "critical opportunity" to minimize impact before construction.

The authors say stronger rules are needed to prevent spills such as the July 2010 accident near Marshall that released more than 800,000 gallons of oil into the Kalamazoo River and Talmadge Creek. Cleanup continues and the pipeline rupture's cause isn't known.

The pipeline is operated by Enbridge Inc. (TSX:ENB) of Calgary. It runs from Griffith, Ind., to Sarnia, Ont.