Environment and Climate Change Canada started an investigation in February 2016 after they were notified by provincial authorities of an ongoing sewage release at Black Lake Denesuline First Nation in Northern Saskatchewan’s Athabasca Basin region. Federal enforcement officers determined that Black Lake Denesuline First Nation failed to notify officials that approximately 86,000 litres of sewage was released into the lake. Black Lake provides drinking water to the community of Black Lake Denesuline First Nation, and contains a number of fish species including walleye, yellow perch, northern pike and arctic grayling. Under the Fisheries Act, all persons having the charge, management or control of a deleterious substance, or of activities that result in a deposit of a deleterious substance into fish-bearing water, must immediately notify officials of an unauthorized deposit if its detrimental to fish or fish habitat.