Who turned the Niagara River black?
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Niagara Falls: Smelly black water shocks visitors

Tourists visiting Niagara Falls were shocked to see black, foul-smelling discharge spewing into the famous river on Saturday.

The local water board has since apologised for "causing alarm" by releasing water containing carbon residue and other solids after "routine" maintenance work on its sewage works.

It says the discharge was "within permitted limits".

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