NIAGARA FALLS, N.Y. — A public water board blames outdated equipment and miscommunication between employees for a discharge that turned the water below Niagara Falls black and smelly at a busy tourist site.

In a report to the Department of Environmental Conservation on Friday, the Niagara Falls Water Board says current technology at the wastewater treatment plant makes it difficult to manage sulfide. That results in periodic odors and darkened wastewater being released into the river.

The board said the problem on July 29 was worsened by a misunderstanding between employees. It said a pump should have been turned off when effluent turned dark during dewatering.

The board recommended costly solutions including changing where water discharges or using a new treatment process. It also identified immediate steps including procedural changes and modifying a pump.