UPDATE 1-Enbridge says no restart date for ruptured line

* Restart of Michigan line in hands of regulators

* As much as 6,000 barrels collected from spill

* Oil is not advancing toward Lake Michigan - EPA (Adds comments from EPA chief, visit to spill site)

By Bernie Woodall and Scott Haggett

DETROIT/CALGARY, July 30 (Reuters) - Enbridge Inc's (ENB.TO: Quote) chief executive said on Friday he was unable to say when the company would be able to restart the Michigan pipeline that ruptured earlier this week, spilling more than 800,000 gallons of oil.

U.S. Environmental Protection Agency Administrator Lisa Jackson said she was "very confident" that the oil's progress toward Lake Michigan has been stopped.

Jackson on Friday flew over the spill area including the oil-fouled Kalamazoo River with Michigan Gov. Jennifer Granholm and Debbie Stabenow, Democrat senator from the state's capital, Lansing.

The three women said in a Friday night press conference that they were pleased with progress of workers to contain the spill that Enbridge noticed on Monday. Granholm said federal officials and Enbridge have rallied to respond to the spill in the past several days after what she called a slow start.

While Enbridge Chief Executive Pat Daniel said that making the pipe ready to resume operation can take only a matter of days, but he said a restart of the pipeline is in the hands of U.S. regulators.