(Top) 1977 Improvements to the City of Spokane Wastewater Treatment Plant to help improve water quality.
(Bottom) The City of Spokane Wastewater Treatment Plant
in 2009.





























Water Quality Improvements
The Spokane River Stewardship Partners have improved the health of the Spokane River.

Current Improvements

  • Spokane County completed construction of a state-of-the-art water reclamation facility in 2011 that treats wastewater to ultra clean levels and led a regional study to reduce phosphorus nonpoint sources into the river. To learn more, click here.
  • Inland Empire Paper Company has invested over $9 million in innovative wastewater treatment upgrades over the past five years in a proactive effort to meet new and more stringent water quality standards.
  • The City of Spokane is conducting an 18-month treatment technology study to identify the best ways to remove phosphorus from wastewater being treated at the reclamation facility.
  • The City of Coeur d'Alene is completing significant upgrades to their plant to reduce ammonia.
  • Liberty Lake Sewer and Water District recently spent $12 million upgrading its treatment plant to remove 80% more phosphorus. 
  • Avista received a new 50-year license from the Federal Energy Regulatory Commission to operate its five hydroelectric facilities (Post Falls, Upper Falls, Monroe Street, Nine Mile, and Long Lake) located on the Spokane River on June 18, 2009. As part of the new license Avista will be implementing a number of conditions that will support water quality improvements in the Spokane River and Lake Spokane.
  • In 2009, the City of Post Falls began construction of its treatment plant expansion which will add biological nitrogen reduction for sustainable, year-round improvements to the Spokane River.
  • Hayden Area Regional Sewer Board upgraded their treatment plant to accommodate growth in 2008. They do not discharge effluent to the Spokane River during the growing season; during this time they use all the treated effluent on their water reuse farm to grow livestock feed and poplar trees. 

For more information on water quality improvements, check out our historical timeline that highlights milestones over the last century along with photos


Spokane Watershed TMDLs

Spokane River DO TMDL 
The Spokane River, in particular within the Lake Spokane reservoir, has low dissolved oxygen (DO) levels during low flow in the summer months. Portions of the Lake Spokane reservoir violate the Washington State water quality standards for DO, and are listed on the 2004 list of impaired water bodies. Maintaining good water quality in the river and lake, especially adequate concentrations of DO, is important for supporting fish, invertebrates and other aquatic life.

A computer model was used to predict water quality changes in response to varying river flow, and types, quantity, and locations of wastewater discharges. This model was a tool that was used to establish the total maximum daily load (TMDL) of pollutants that can be discharged to the river, as well as to develop a Spokane River Water Quality Improvement Plan that addresses dissolved oxygen needs in the Lake Spokane reservoir. This plan was completed in 2009 and approved by EPA in 2010. To find out more information on the Spokane River DO TMDL project, click here to get to Ecology's web site.

Hangman Creek TMDL
The Hangman Creek (also known as Latah Creek) watershed has been influenced by land uses (agriculture, impervious surfaces, timber harvest, roads, etc.) as well as stream channel and flood plain alterations over the last 100-years that have contributed to “flashy” flow conditions, unstable stream banks, and substandard water quality.  

To address the water quality problems in the Washington portion of the watershed, Ecology and the Spokane Conservation District (SCD) worked together to develop Total Maximum Daily Loads (TMDL) to clean up polluted water so it meets water quality standards. Ecology published the final water quality improvement report for fecal coliform bacteria, high water temperatures, and turbidity in June 2009. The report was approved by EPA in September 2009.

Since the approval of the TMDL, Ecology and the SCD have worked with agencies and organizations to develop an implementation plan outlining what needs to occur to meet water quality targets in the watershed and various commitments to the effort. Ecology published the final plan and sent a copy to EPA on May 13, 2011.

Hangman Creek also has dissolved oxygen and pH impairments which are typically the result of excess nutrients like nitrogen and phosphorus. Ecology collected water quality data on dissolved oxygen, pH, and nutrients in the watershed. This data will be used to develop a separate TMDL to address these parameters when resources become available. To find out more information on the Hangman Creek TMDL projects
 click here to get to Ecology's web site.

Little Spokane River TMDL
To address water quality problems in the Washington portion of the Little Spokane River watershed, Ecology and the SCD worked together on the water quality improvement project called a TMDL. The Little Spokane River Watershed TMDL focused on fecal coliform bacteria, 
temperature, and turbidity issues. Ecology submitted the final TMDL to EPA for approval in February 2012. EPA approved the TMDL in April 2012. To find out more information on the Little Spokane River Watershed TMDL, click here to get to Ecology's web site.