Tests are still being conducted on the water supply after an estimated 640,000 litres of magnesium chloride spilled into the Oshawa Harbour Sunday.

The spill occurred just after midnight as the product, which can be used to de-ice roadways, was being taken off a ship. The solution spilled onto the shoreline and into the harbour.

According to the Ministry of Environment, the ship is owned by a company called the Miller Group.

“Even though the amount sounds very large . . . the lake is quite a large body of water, so (the spill) is not even a tenth of a percentage, or an hundredth of a percentage (of the lake’s total volume),” explained John Presta, director of environmental services for the Region of Durham.

The solution mixed into the harbour’s water supply and cannot be extracted. The harbour opens into Lake Ontario.