Eastern Canada Response Corp., the oil spill response company, was moving out from the scene after finishing the job Friday afternoon.

Mark S. Brown, a regional manager of Eastern Canada Response, said all of the company's cleanup equipment and the contaminated seaweed gathered from the shore should be gone.

"We are currently in the stage of demobilizing from the site," Mr. Brown said Friday afternoon.

However, the Ministry of the Environment of the Province of Ontario has yet to confirm that the water quality is back to normal. Residents on Dawson Point will be provided with bottled water until the Ministry of Environment determines that it is safe to drink the water from their wells.

About 396 gallons of diesel fuel was spilled Wednesday morning during fueling of the Sea Hound, a tugboat operated by Nadro Marine Services Ltd., a contractor based in Port Drove, Ontario.

The boat was docked at Dawson Point when the spill occurred.

Deborah A. Baxter, a spokesperson of Transport Canada, said it would take four to five days for its staff to determine the cause of the spill.

The tugboats are used to push barges loaded with supplies and parts from Ogdensburg for Canadian Hydro Developers Inc.'s 86-turbine Wolfe Island Wind Project. So far, 28 wind turbines have arrived.

To contain the spill Wednesday morning, Nadro Marine staff first deployed a 100-foot boom around the tugboat to contain the fuel. The Canadian coast guard, which first responded to the scene, deployed an additional 800-foot boom and the ECRC, a private marine oil spill response company, then took over the scene and deployed additional booms, oil-absorbent mats and other containment devices.

By Thursday afternoon, most of the diesel fuel was absorbed by the mats or had evaporated.

Mr. Brown said the spill has not harmed the river's natural habitat and there should be no lasting environmental affects.