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Map of the Great Lakes  Watershed

Map of the Great Lakes Watershed

The Great Lakes Initiative Toxicity Data Clearinghouse is a central location for information on criteria, toxicity data, exposure parameters and other supporting documents used in developing water quality standards in the Great Lakes Watershed.

The Clearinghouse contains information relevant to regulatory and non-regulatory programs.

It can be used to help establish water quality criteria, permit discharge limits, Total Maximum Daily Loads, Remedial Action Plans, and Lakewide Management Plans within the Great Lakes Basin.

In particular, States and Tribes can use the Clearinghouse to help derive criteria for pollutants without specific numeric criteria published in 40 CFR Part 132 of the GLI.

The target audience for the Clearinghouse is State and Tribal environmental agencies in the Great Lakes basin, as well as other interested parties with a technical background.

Where the data comes from

Related information

The Clearinghouse relies on State environmental agencies to provide data, usually in the form of water quality standards fact sheets, to EPA.

The Clearinghouse data was last updated August 2013 (see Version History) and contains data provided by Indiana, Minnesota, New York, Ohio, and Wisconsin.

While Michigan chose not to provide facts sheets, you can contact MDEQ directly (see GLI States & Tribes) to obtain them.

Illinois and Pennsylvania do not have fact sheets for their Great Lakes basin waters, as these two States have limited numbers of discharges to such waters. Should the need arise for water quality criteria, these states may choose to generate criteria according to their regulations and in that event fact sheets may be available.

The Clearinghouse will be updated as States and Tribes revise or adopt new criteria and provide data to EPA; however there may be a lag between the publication of new or revised criteria and the uploading of new data into the Clearinghouse.

The GLI Clearinghouse is essentially a central access point for available data; it should not be considered an official site for State/Tribal criteria or supporting information. Users interested in official information should refer to the original State documents or contact the State/Tribal agency directly.


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