Band officials have declared a state of emergency on the Constance Lake First Nation.
The move comes following an algae bloom that appeared eight days ago on the lake that supplies drinking water for the Reserve.
That's left the 900 residents of the community trying to meet their drinking water, cooking and hygiene needs with bottled water and a small supply trucked in from nearby Hearst.
Band Chief Arthur Moore said he is demanding urgent action to address the water crisis.
The chief said he wants Indian Affairs to immediately upgrade the community’s water treatment plant to bring it into compliance with existing provincial regulations.