Water turns black near Niagara Falls

The water near the base of Niagara Falls turned an alarming shade of black before tourists' eyes over the weekend following a foul-smelling discharge from a wastewater treatment plant.

The water board for the city of Niagara Falls, N.Y., said the discharge on Saturday was part of routine maintenance of one of its basins.

Video taken from a helicopter shows black-coloured water along the Niagara River's U.S. shoreline below the falls that border the country and Canada. The inky water enveloped the dock for the popular Maid of the Mist tour boats.

Officials say the blackish water contained accumulated solids and carbon residue but no organic oils or solvents. They described the odour as "normal sewer water discharge smell." The board says the discharge was within permitted limits.

The black water had dissipated by Sunday.