The Maid of the Mist boat tour is one of the most enduring and popular tourist attractions in western New York, visited by more than 1.5 million people a year. On a busy summer weekend in 2017, tourgoers expecting to feel the spray of Niagara Falls on their faces instead were taken aback by a foul-smelling black plume spreading underneath the boat from the shoreline near the falls. The source of the sludgy water was attributed to discharge from the Niagara Falls Wastewater Treatment Plant that occurred as part of routine daily maintenance of one of its wastewater sedimentation basins.
That incident, along with several discharges by the wastewater treatment plant into the Niagara River triggered by overflow from heavy rains, resulted in $50,000 in fines from the New York Department of Environmental Conservation.
Under pressure to avoid further fines and another international spectacle, wastewater treatment plant officials determined that a weir — a wall or barrier to regulate flow — would put an end at least to the inky discharge. This would prevent the black carbon dust that results from cleaning of the carbon filters from discharging directly into the Niagara River by ensuring the mixing of effluent and flush waters en route to discharge.