While the article doesn't say where the proposed pit will be, there is already an active pit and a large commercial landfill on Millstream
Take a look at Google Maps, locate Western Speedway.
There is a large gravel pit/quarry just north of the Speedway, and then untouched forest land just to the north of that.
OK wants to develop the untouched forest land between the rock quarry just north of the Speedway and the Coast Environmental landfill just north of the untouched forest.
The eastern boundary of the proposed quarry would butt up against the western boundary of Thetis Lake Park.
It won't extend all the way to the Millstream Road though, as some of the land just to the east of Millstream Road belongs to the CRD.