The Willamette Basin

Coast Fork Willamette Subbasin Columbia Slough Watershed Middle Willamette Subbasin Rickreall Creek Molalla-Pudding Subbasin Tualatin Subbasin Willamette Basin Yamhill Subbasin Basin Contact Information

Willamette Basin

Proposed Modifications to the Willamette Basin TMDL

The Oregon Department of Environmental quality is proposing to revise the thermal pollution limit for the City of Jefferson’s wastewater treatment plant located at 701 North Second Street, Jefferson OR, 97352. The Jefferson Wastewater Treatment Plant discharges heated effluent to the Santiam River.

The purpose for this TMDL modification is to correct a spreadsheet unit error that resulted in the incorrect calculation of the thermal pollution limit for Jefferson’s wastewater treatment plant.

The public comment period is now closed. For more information, see the following documents:

• Public Notice PDF
• Willamette TMDL Addendum PDF

Additional information regarding the Willamette Basin TMDL, including the Willamette Basin Rivers and Streams Assessment.

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TMDL approved by the US Environmental Protection Agency (EPA) on September 29, 2006

• TMDL Order Memorandum - September 21, 2006 PDF
   
• Executive Summary PDF
• Acknowledgements PDF
• Glossary of Acronyms and Terms PDF
• Chapter 1: Overview PDF 2.1 mb
• Chapter 2: Willamette Basin Bacteria TMDL PDF
• Chapter 3: Willamette Basin Mercury TMDL PDF 1.5 mb
• Chapter 4: Temperature-Mainstem TMDL and Subbasin Summary PDF 6.3mb
• Chapter 5: Lower Willamette Subbasin TMDL PDF 9.6 mb
• Chapter 6: Clackamas Subbasin TMDL PDF 3.5 mb
• Chapter 7: Middle Willamette Subbasin TMDL PDF 6.7 mb
• Chapter 8: North Santiam Subbasin TMDL PDF 3.5 mb
• Chapter 9: South Santiam Subbasin TMDL PDF 4.8 mb
• Chapter 10: Upper Willamette Subbasin TMDL PDF 15.2 mb
• Chapter 11: McKenzie Subbasin TMDL PDF 3.3 mb
• Chapter 12: Middle Fork Willamette Subbasin TMDL PDF 3.8 mb
• Chapter 13: Coast Fork Willamette Subbasin TMDL PDF 6.0 mb
• Chapter 14: Water Quality Management Plan (WQMP) PDF
• Appendix A: Bacteria PDF 1.8 mb
• Appendix B: Mercury PDF 2.8 mb
• Appendix C: Temperature PDF 11.0 mb

   Willamette River Basin Temperature TMDL modeling reports from Portland State University and USGS:

• CE-QUAL-W2 Boundary Conditions and Model Setup (PSU) PDF 30.8 mb
• CE-QUAL-W2 Model Calibration Report (PSU) PDF 9.5 mb
• CE-QUAL-W2 Model Scenarios Report (PSU) PDF 12.9 mb
• North Santiam and Santiam Rivers Modeling Report (USGS) PDF 2.6 mb

• Willamette CE-QUAL-W2 models
• Additional information about the CE-QUAL-W2 model

• Response to Public Comments PDF 8.0 mb

Coast Fork Willamette Subbasin

TMDL approved by EPA on May 17, 1996

• Total Maximum Daily Load (TMDL) PDF

Columbia Slough Watershed

TMDL approved by EPA on November 25, 1998

• Columbia Slough Watershed Map PDF 1.3mb
  
• Total Maximum Daily Loads (TMDLs) PDF 1.0mb

Middle Willamette Subbasin

Rickreall Creek

TMDL approved by EPA on April 18, 1994

• Total Maximum Daily Load (TMDL) PDF

Molalla-Pudding Subbasin

TMDL approved by EPA on December 31, 2008

• TMDL Order Memo PDF

• Executive Summary PDF
• Chapter 1: Overview PDF
• Chapter 2: Temperature PDF
• Chapter 3: Bacteria PDF
• Chapter 4: Pesticides PDF
• Chapter 5: Nitrate PDF
• Chapter 6: Metals PDF
• Chapter 7: Water Quality Management Plan (WQMP) PDF
• Appendix A: Temperature Analysis PDF
• Appendix B: Willamette Near Stream Land Cover PDF
• Appendix C: Heat Source Model PDF
• Appendix D: Example Effluent Temperatures PDF
• Appendix E: Natural Thermal Potential Estimation PDF
• Appendix F: Bacteria Analytical Methods PDF
• Appendix G: Bacteria Data Review PDF
• Appendix H: Bacteria Statistical Test PDF
• Appendix I: Current Pesticides PDF
• Appendix J: Pesticide Analysis PDF
• Appendix K: TSS Turbidity Model PDF
• Appendix L: Nitrate Analysis PDF
• Appendix M: Metals Analysis PDF

• Response to Public Comment PDF

Pudding River 

TMDL approved by EPA on December 18, 1993

• Total Maximum Daily Load (TMDL) PDF

Tualatin Subbasin

Tualatin Subbasin TMDL Revision

DEQ accepted comments on draft documents describing pollution limits and plans to improve water quality in the Tualatin River subbasins and ensure streams are healthy for fish and wildlife, and safe for fishing and swimming. The comment period closed on Dec. 14, 2011.

Fact Sheet PDF Draft Executive Summary PDF Draft Chapter 1: Overview and Background PDF Draft Chapter 2: Revised Temperature Total Maximum Daily Load PDF Draft Chapter 3: Amendment for the Total Phosphorus TMDL PDF Draft Chapter 4: Amendment for the Ammonia TMDL PDF Draft Chapter 5: Water Quality Management Plan & Pollutant Trading PDF

Draft Appendices Appendix 2A: Temperature Criteria (as of March 2004) PDF Appendix 2B-1: Point Source Allocations for Discharges to Tributaries in the Tualatin Subbasin TMDL PDF Appendix 2B-2A: Tualatin River Total Maximum Daily Load Temperature Modeling Final Report PDF Appendix 2B-2B: USGS Model Documentation PDF Appendix 2B-3: Tualatin River Total Maximum Daily Load Temperature Wasteload Calculations PDF Appendix 2C-1: Lower Willamette Subbasin--Ecoregional Characterization of Vegetation PDF Appendix 2C-2: How to Use a Shade Curve PDF Appendix 3A: Tualatin River Total Maximum Daily Loads: Total Phosphorus & Dissolved Oxygen Analysis for the Upper River Final Report PDF Appendix 3B: Tualatin River Total Maximum Daily Loads for Total Phosphorus (4/20/2009) Phosphorus Control Period PDF Appendix 4A: See Chapter 4

TMDL approved by EPA on August 7, 2001

• Total Maximum Daily Load (TMDL) and Water Quality Management Plan (WQMP) PDF 3.5mb
• Appendix A: Temperature Technical Analysis PDF 16.5mb
• Appendix B: Bacteria Model Description PDF
• Appendix C: Supporting Documents for the Chlorophyll A/pH (Phosphorus) TMDL PDF
• Appendix D: Supporting Documents for the Dissolved Oxygen TMDL PDF
• Appendix E: Low pH Discussion PDF 1.2mb
• Appendix F: Tualatin Subbasin Fish Habitat and Fish Community Information PDF 1.7mb
• Appendix G: Toxics Discussion PDF
• Appendix H: Biological Criteria Discussion PDF
• Appendix I: Tualatin Subbasin Water Quality Management Plan (WQMP) PDF
   
• Response to Public Comment PDF 1.1mb

Yamhill Subbasin

TMDL approved by EPA on March 16, 1992

• Total Maximum Daily Load (TMDL) PDF

   TMDL Report In-Progress (Data analysis and report writing phase) - For updated TMDL.

•  Yamhill Subbasin TMDLs Home Page

Contact Information

• Basin Coordinator List PDF

 

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