Reuters: Enbridge Inc’s chief executive said on Sunday the company would not restart its ruptured pipeline in Michigan this week as it continues to clean up 800,000 gallons of oil spilled in and around the Kalamazoo River. Meanwhile, the Environmental Protection Agency (EPA) said there was “significant improvement” at the spill site after almost a week and no signs of new contamination. Officials also gave an update on the cleanup efforts, saying 39,000 barrels — about 1.6 million …