Water Quality Improvement Project
South Fork Palouse River:


The South Fork Palouse River drains 130 square miles around the towns of Pullman and Albion in Washington and Moscow, Idaho. Grain fields and pastures dominate the area. The major land use is farming with residential, commercial, and industrial developments clustered around the towns.

Water quality issues

The South Fork Palouse River and several other tributaries are impaired for one or more of the following pollutants: ammonia; dissolved oxygen; fecal coliform bacteria; PCBs; chlorinated pesticides; temperature; and pH.

Status of the projects

The following is the timeline for the South Fork Palouse River watershed water quality improvement project.

Dissolved oxygen / pH / Temperature

Dissolved oxygen, pH, and temperature affect the health and distribution of fish and other aquatic life. The South Fork Palouse River is impaired by high temperatures, low dissolved oxygen, and pH outside the range appropriate for fish and other aquatic life. Excessive nutrients in the stream (for example nitrogen, including ammonia, and phosphorus) can affect the level of dissolved oxygen and pH in the stream.

  • From May 2006-October 2006 Ecology conducted a temperature study. It ran during the time of year when the water is most likely to be impaired. Another study examined dissolved oxygen, pH, and nutrients. Data for the dissolved oxygen and pH study were collected in conjunction with the bacteria study and intensive surveys that were conducted in June and August 2006.
  • In late 2009, Ecology applied for EPA funding to hire a contractor to study the aquatic life (fish and insects) in the streams. In May 2010 a contract was awarded to Tetra Tech, Inc. to research historical literature about aquatic life in the watershed and collect fish and insects during the summer/fall of 2010. This information will assist Ecology in determining the appropriate water-quality standard criteria to protect the stream for the aquatic species that should be present in the watershed under natural conditions (unaltered by human activities). Tetra Tech’s final report was completed in spring 2011.
  • In June and August 2010, Ecology conducted additional intensive surveys of dissolved oxygen, pH, and nutrients. The purpose of these studies was to determine the effect of changes at the Moscow wastewater treatment plant, located just across the state line on Paradise Creek, on water quality downstream in Washington. The Moscow treatment plant installed filtration to significantly reduce the amount of nutrients discharged to Paradise Creek. This additional information will be useful to further calibrate the computer model Ecology is using to analyze the watershed.

Fecal coliform bacteria

Fecal coliform bacteria come from the intestinal tract of warm-blooded animals and can indicate the presence of human and animal waste which may carry disease-causing organisms.

  • From May 2006-May 2007, Ecology conducted a study that examined the levels and distribution of fecal coliform bacteria throughout the watershed. The study found that the South Fork Palouse River; Paradise Creek; Airport Road Creek; Missouri Flat Creek; Dry Fork Creek; Spring Flat Creek; Staley Creek; and Four Mile Creek violate the fecal coliform bacteria water quality standards during a portion of the year.
  • In June 2008, Ecology formed an advisory group to review the studies' results and recommend strategies to improve water quality. More information about the activities of the advisory group are available on the SFPR TMDL Advisory Group page.
  • In August 2009, Ecology completed the water quality improvement report on fecal coliform bacteria. After the public comment period, Ecology addressed the comments received. On October 22, 2009 Ecology submitted the final improvement report to EPA. EPA approved the submittal in January 2010.
  • Ecology, with the assistance of several entities and the SFPR TMDL Advisory Group, developed an implementation plan describing how the water quality goals in the water quality improvement report will be implemented. The draft plan was available for public review until November 18, 2011. After Ecology reviewed and responded to comments received, we sent a copy of the finalized plan to EPA for their records.


During the Palouse River toxics study, the South Fork Palouse River was found to be impaired for PCBs and dieldrin (a chlorinated pesticide). These impairments are addressed through the Toxics TMDL, which EPA approved in November 2007.


A TMDL for ammonia in the South Fork Palouse River, including Paradise Creek, was completed in 1993. After this TMDL was approved, the water quality criteria for ammonia was changed. An addendum to the original TMDL to reflect the revised criteria was published in 1995.


To learn more about the importance of these various parameters, please see our water quality impairments page.

Technical information

Unless otherwise specified, the following documents are Ecology publications.

Streamflow Summary for the Palouse and South Fork Palouse Rivers and Selected Tributaries, 2006-08

Dissolved oxygen / pH / Temperature

Quality Assurance Project Plan: South Fork Palouse River Dissolved Oxygen and pH Total Maximum Daily Load Study

South Fork Palouse River Temperature TMDL Study Quality Assurance Project Plan

Instream Assessment of Biota and Migration Patterns of the South Fork Palouse River Watershed

Quality Assurance Project Plan for In-Stream Assessment of Biota and Migration Patterns of the South Fork Palouse River Watershed (Tetra Tech)

Fecal coliform bacteria

South Fork Palouse River Watershed Fecal Coliform Bacteria Total Maximum Daily Load: Water Quality Implementation Plan

South Fork Palouse River Fecal Coliform Bacteria TMDL: Water Quality Improvement Report

Quality Assurance Project Plan: South Fork Palouse River Fecal Coliform Bacteria Total Maximum Daily Load Study

Related information


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Last updated February 2016


WRIA: #34 (Palouse)
County: Whitman

Water-body Names:
South Fork Palouse River
Paradise Creek
Airport Road Creek
Missouri Flat Creek
Dry Fork Creek
Spring Flat Creek
Staley Creek
Four Mile Creek

Dissolved oxygen
Fecal coliform bacteria
PCBs and dieldrin

# of TMDLs:
Ammonia-N - 1
Fecal coliform bacteria - 4

Ammonia-N - Approved by EPA.
Fecal coliform bacteria - Approved by EPA.
Has implementation plan.
Dissolved oxygen/pH/Temperature - under development.

Contact Info:
Elaine Snouwaert
Phone: 509-329-3503
Email: Elaine.Snouwaert@ecy.wa.gov

Eastern Region
Department of Ecology
4601 N Monroe Street
Spokane, WA 99205-1295