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Listing Impaired Waters and Developing TMDLs

What is the 303(d) list? What is a total maximum daily load (TMDL)? How is a TMDL developed? The answers to these and many other questions related to TMDLs can be found on this supplemental information module as part of the Water Quality Standards Academy.

This course is not only an introductory unit for those with little familiarity with impaired waters, the 303(d) list and TMDLs but also a refresher course for those with experience in the subject. The course concludes with a brief quiz intended to touch on some of the key concepts. The main pages and quiz are designed to take users approximately 20 minutes to complete. (Note that quiz responses are not scored or recorded.)

Additional information about impaired waters can be found on EPA’s website on Impaired Waters and TMDLs or on your state water quality agency website.