Eutrophication or Undesirable Algae

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The Stage 1 RAP indicates that Eutrophication (excessive amounts of algae) were observed in slow-moving waters downstream of Sault Sainte Marie, Ontario’s East End Water Pollution Control Plant.

In 2006, the East End plant was upgraded to include secondary treatment, and its effluent pipe was relocated to a faster-moving part of the river.

Guidance for Delisting of Eutrophication or Undesirable Algae BUI

The Guidance for Delisting states that the BUI will be considered restored when:

“No waterbodies within the AOC are included on the list of non-attaining waters due to excessive algal growths from high nutrient loadings in the most recent Clean Water Act Water Quality and Pollution Control in Michigan: Section 303(d) and 305(b) Integrated Report (Integrated Report), which is submitted by DEQ to U.S. EPA every two years.


in cases where water bodies within the AOC are either on the nonattainment list or exhibit excessive algal growth from high nutrient loadings, this BUI will be considered restored when no persistent or high levels of nuisance algal growths or nuisance algal blooms occur for 2 consecutive monitoring cycles.”