Detoxifying Pit Lakes by Controlled Algal Blooms: Laboratory Study and Pilot Field Trial at little Creek Pond at Vangoda Pit near Faro, Yukon, Canada

When a mine closes, the open pit left behind often fills with water that washes metals from the pit walls. This water may be toxic and cannot be disharged without further treatment. This study evaluated the possibility of using algal blooms to remove toxic metals from pit lakes. The study had two components: laboratory tests and pit lake fertilization trials. The site for the field trial was Little Creek Pond, a small collection pond located at Vangorda Pit, near Faro, Yukon. The pond receives zinc-contaminated leachate from a waste rock dump and seepage from Vangorda Pit.Leachate is water that has percolated through soil or rock containing soluble substances such as zinc and that contains certain amounts of these substances in solution. The laboratory study, using Little Creek Pond water, demonstrated that zinc could be removed by promoting an algal bloom. Its concentrations were decreased dramatically during the 56-day study (from starting concentrations of 55 mg/L down to 3 mg/L). An interesting finding was that zinc was removed if pond sediments were present, but not if they were absent. The high initial zinc concentrations may have been too toxic to allow the development of…

Publisher

Government of Yukon

Resources

3

Catalogue metadata updated

2026-08-26