DULUTH — A Chicago-based environmental group warned in a new report against increased shipment of petroleum products on the Great Lakes, particularly a plan to ship oil out of Superior, Wis.

A report from the Alliance for the Great Lakes said U.S. and Canadian shipping fleets and ports aren’t designed for large-scale crude oil transports, and that neither government’s regulatory systems are prepared to deal with increased shipments across the lakes.

An Indiana-based company that owns a Superior refinery is planning a $30 million port terminal where oil from western pipelines would be transferred onto Great Lakes tankers and barges. An official with Calumet Special Products said the company is pursuing state and federal permits.

The report also contended that western Canadian “tar sands” oil, likely to be one type shipped across the lakes, may not be controlled by traditional oil-spill cleanup methods. Tar crude “is extremely difficult, potentially even impossible, to completely remove from the water after a spill,” the report said, noting that Great Lakes depths would likely make it even more difficult.

Project supporters note that oil has been shipped on the lakes for more than a century without catastrophic problems.

The Alliance suggests a number of policy changes before oil could be shipped on the lakes, including greater coordination between U.S. and Canadian regulators and more federal dollars for oil spill prevention, preparedness and response.