Glossary of Terms

There are several technical terms frequently used when discussing Areas of Concern and their Remedial Action Plans. This glossary has been created as a resource for our readers to reference when reviewing reports and other resources related to Areas of Concern and the implementation of Remedial Action Plans.

Area of Concern (AOC)– AOCs are geographic areas within the Great Lakes system where severe environmental degradation has occurred, and were identified under the 1987 Great Lakes Water Quality Agreement.

Beneficial Use Impairment (BUI) – A BUI is a common use or feature of a waterway that has been negatively impacted due/by to local environmental degradation. There are 14 BUIs that are evaluated for each AOC. Each BUI is assigned a status:

• Impaired – the BUI has been negatively impacted and action is required to restore its quality.
• Not Impaired – the beneficial use has not been negatively impacted.
• Requires Further Assessment (RFA) – More data/research is needed to determine an impaired or not impaired status.

Combined Sewer Overflow (CSO) – Combined storm and sanitary sewer systems.

 Delist – The removal of an Area of Concern (AOC) from the list of AOCs achieved only when the criteria for the restoration of beneficial uses as defined by the Remedial Action Plan (RAP) are met and agreed upon by agencies and the local community.

Redesignation –  When restoration goals for an impaired BUI have been met, the status can be changed (redesignated) to “not impaired”.