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Lower Columbia-Sandy Subbasin TMDL

Proposed rule

Rulemaking contact: Michele Martin, 503-880-7737

In 2013, the United States Environmental Protection Agency disapproved the Natural Conditions Criterion contained in Oregon's water quality standard for temperature due to the 2012 U.S. District Court decision for NWEA v. EPA, 855 F. Supp. 2d 1199 (D. Or., 2012). This portion of the temperature water quality standard was used in most temperature TMDLs issued from 2003 through 2012. On Oct. 4, 2019, the U.S. District Court issued a judgment for NWEA v. EPA, No. 3:12-cv-01751-HZ (D. Or., Oct. 4, 2019) and required DEQ and USEPA to replace 15 Oregon temperature TMDLs that were based on the Natural Conditions Criterion and to reissue the temperature TMDLs based on the remaining elements of the temperature water quality standard.

DEQ will present this TMDL to the Environmental Quality Commission for proposed rule adoption in July 2024. Per the District Court's final order and judgement, DEQ must amend and submit replaced temperature TMDLs to EPA for approval or disapproval. The schedule for the Lower Columbia-Sandy Subbasin TMDL will be submitted to EPA in July 2024, for determination by Sept. 15, 2024.

Advisory committee

DEQ plans to hold two rulemaking advisory committee meetings for the Lower Columbia-Sandy Subbasin. The role of the rulemaking advisory committee is to advise DEQ on the following: 

  • Economic and fiscal impacts of the proposed rules for entities impacted by the proposed TMDL 
  • Revision of required TMDL elements with a focus on the TMDL allocations to be updated based on the current temperature criteria for the Lower Columbia-Sandy Subbasin project area
  • Revisions to the Water Quality Management Plan
Committee documents
  • Advisory Committee Charter
  • Advisory Committee Roster

Public comment

DEQ invites the public to submit comments on the proposed rules. The comment period closed at 4 p.m. on Feb. 26, 2024.

For more information, see the Notice of Proposed Rulemaking, which includes the notice and proposed rules.

Supporting documents


Public hearing

Online only, Feb. 16, 2024.

DEQ held a public hearing to present information, answer questions, and accept comments. The hearing was held remotely via Zoom and was open to everyone

Public involvement

Webinar 2: March 21, 2023, 2 p.m. PT
DEQ held an informational webinar about the Temperature Total Maximum Daily Load Replacement for the Lower Columbia-Sandy Subbasin. The webinar provided an opportunity to exchange questions and answers about the technical approach to revising the TMDL.

Webinar 1: Jan. 31, 2023 

DEQ held an informational webinar about the Temperature Total Maximum Daily Load Replacements for the Lower Columbia-Sandy Subbasin and the Willamette Subbasins. The webinar provided information about the rulemakings and the technical approach to revising the TMDLs and the Water Quality Management Plans.  

EQC action

DEQ will present this TMDL to the Environmental Quality Commission for proposed rule adoption in July 2024.