OTTAWA  An extensive review of Canada’s oil sands released on Wednesday rejected several claims from both the energy industry and environmentalists while accusing Canadian governments of inadequate oversight of the projects.

The deposits in northern Alberta of tarlike bitumen mixed with sand and other minerals have helped Canada become the largest supplier of imported oil to the United States.

But the projects also use significant amounts of energy and water to dig up deposits and then transform the bitumen into synthetic crude oil while leaving behind large, toxic waste ponds. That has made the projects a target for environmentalists around the world.

While the 438-page report published by the Royal Society of Canada found much to criticize in the oil sands, it also dismissed a common claim by environmentalists that the operations were the most environmentally destructive projects on earth.