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 on Sept. 29, 2006

• TMDL Order Memorandum - Sept. 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
• Response to Public Comments PDF 8.0 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

Coast Fork Willamette Subbasin

TMDL approved by EPA on May 17, 1996

• Total Maximum Daily Load PDF

Columbia Slough Watershed

TMDL approved by EPA on Nov. 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 PDF

Molalla-Pudding Subbasin

TMDL approved by EPA on Dec. 31, 2008

• TMDL Order Memo - Dec. 8, 2008 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 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 Dec. 18, 1993

• Total Maximum Daily Load PDF

Tualatin Subbasin

Tualatin Subbasin TMDL Revision

• TMDL Order Memo - Aug. 28, 2012 PDF
• Fact Sheet: Working for Clean Water in the Tualatin River Subbasin PDF
• Executive Summary PDF
• Chapter 1: Overview and Background PDF
• Chapter 2: pH and Chlorophyll a (Total Phosphorus) TMDL Amendment PDF
• Chapter 3: Amendment to 2001 Waste Load Allocations for Ammonia Under 2001 Dissolved Oxygen TMDL for the Tualatin Basin PDF
• Chapter 4: Water Quality Management Plan PDF
• Appendix 2-A: Tualatin River Total Maximum Daily Loads: Total Phosphorus and Dissolved Oxygen Analysis for the Upper River Final Report PDF
• Appendix 2-B: Tualatin River Total Maximum Daily Loads for Total Phosphorus (4/20/2009) Phosphorus Control Period PDF
• Appendix 3-A: Changes to the 2001 Dissolved Oxygen TMDL for the Tualatin Basin PDF
• Response to Comments PDF

TMDL approved by EPA on August 7, 2001

• Total Maximum Daily Load and Water Quality Management Plan PDF
• Appendix A: Temperature Technical Analysis PDF (16.5 MB)
• 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
• Appendix F: Tualatin Subbasin Fish Habitat and Fish Community Information PDF
• Appendix G: Toxics Discussion PDF
• Appendix H: Biological Criteria Discussion PDF
• Appendix I: Tualatin Subbasin Water Quality Management Plan PDF 
• Response to Public Comment PDF

Yamhill Subbasin

TMDL approved by EPA on March 16, 1992

• Total Maximum Daily Load PDF

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

For more information on the Yamhill Subbasin and TMDL update, see the Yamhill Subbasin TMDLs home page.

Contact Information

• Basin Coordinator List PDF

 

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