The closure of a copper smelter in Timmins, Ontario included the task of emptying three ponds containing approximately 288,000 m³ of acidic water (pH: 1.4-3.6) with a high metal content (maximum zinc concentration: 43,820 mg/L).

Sanexen was retained to design, install and operate a water treatment system on site. The acidic water was treated using a continuous feed of lime slurry produced on-site. More than 10 km of 8-inch-diameter piping was installed for a dual purpose: pumping the raw water and lime slurry to the treatment pad, and discharging treated water into the tailings management area. A total of 10 pumps were in operation during peak periods. The system was designed to operate in highly corrosive conditions upstream and to prevent scaling downstream.

Water treatment was conducted over two consecutive summers, and water was also pumped out of the pond throughout the winter season.