Liberte Environmental Associates

TMDLs Potentially Affecting Water Quality


Current Draft TMDLs - Released by Oregon Department of Environmental Quality

Tualatin River Basin TMDL: Draft TMDL Related Documents

Draft TMDL comment period ended on December 14, 2011. This watershed is located in northwest Oregon.

Tualatin River Basin Watershed Draft TMDL Public Notice (public comment period ended on December 14, 2011)

Tualatin River Basin Watershed TMDL Fact Sheet

Tualatin River Basin Watershed TMDL Executive Summary

Tualatin River Basin Watershed TMDL Main Report (4.5 MB, chapters compiled*)

Tualatin River Basin Watershed TMDL Report Appendices (8.1 MB, appendices compiled*, no Appendix 1 was offered by DEQ)

Tualatin River Basin Watershed - Existing TMDL finalized in 2001

Links to Tualatin Basin NPDES Permits for sewage treatment plants (STP):
Forest Grove STP
Hillsboro STP
Rock Creek STP
Durham STP

DEQ originally provided the Draft Tualatin Watershed TMDL documents in smaller size, separate chapters and appendices, as follows:
Chapter 1 - Introduction
Chapter 2 - Temperature
Chapter 3 - Phosphorus
Chapter 4 - Ammonia
Chapter 5 - WQ Management & Pollutant Trading

Separate Appendices (no Appendix 1 was offered by DEQ)
Appendix 2A - Temperature Criteria (from March 2004)
Appendix 2B-1 - Point Source Allocations
Appendix 2B-2A - Temperature Modeling
Appendix 2B-2B - USGS Model Documentation (locked document)
Appendix 2B-3 - Temperature Wasteload Calculations
Appendix 2C-1 - Lower Willamette Subbasin - Ecoregional
Appendix 2C-2 - Shade Curve
Appendix 3A - Phosphorus and Oxygen Analysis - Upper River
Appendix 3B - Phosphorus Loads and Control
Appendix 4 - Not provided by DEQ but the reader is referred to Chapter 4.

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