DEQ is in the process of revising multiple temperature TMDLs that were issued by DEQ and approved by EPA between 2004 and 2010, including the Umpqua Basin temperature TMDL. EPA and the State of Oregon are working collaboratively under a federal court order to reissue these temperature TMDLs to make them consistent with current temperature standards. These TMDLs must be updated because they were based, in part, on the Natural Conditions Criterion, a section of the temperature standard that was subject to litigation and that the EPA determined should not be used to establish TMDLs.
DEQ requested EPA assistance to complete the Umpqua temperature TMDL revision by the court-ordered deadline of Feb. 28, 2025. DEQ lacks the resources to work on the Umpqua temperature TMDL and complete all the necessary work for the remaining temperature TMDLs that must also be revised.
Find out more at the Umpqua River Basin Temperature TMDL replacement web page.