The City of Wenatchee provides sanitary sewer services to all residences within the City limits, north of the Wenatchee River bridge in Olds Station and in portions of the Sunnyslope area within the Growth Management Boundary. To view the the City of Wenatchee sanitary service area, please visit the City's GIS City Map, Maps

If you are having a sewer issue that you would like to report please call 509-888-3235 during business hours.  If you are having an after-hour sewer emergency please call  (509) 665-2236.

Collection and Treatment
All of the wastewater is transported via an underground network of piping and pump stations called the Collection System to the Wastewater Treatment Plant located on Worthen Street. The Wastewater Treatment Plant is one of the City’s most expensive and complicated facilities. The wastewater is processed through several physical and biological treatment processes and finally disinfected through an ultraviolet light exposure process that kills all harmful bacteria before being discharged to the Columbia River. The treated discharge or effluent meets or exceeds stringent water quality parameters before it is discharged.

The fragile biological treatment process commissions the services of millions of bacteria to perform the lengthy treatment functions. In order to protect the populations of bacteria from toxic discharges of illegal substances, the City administers a pre-treatment program to help ensure the high quality of our effluent and biosoilds, and to remain in compliance with our state discharge permit. 

Collection System Cleaning and Maintenance

The sanitary sewer system requires cleaning and routine maintenance to prevent blockages and back-ups. To clean the system, City crews use an educator truck (Pictured below). The truck is equipped with a cleaning nozzle that is propelled from one manhole to the next using high pressure water and then pulled backward. As the nozzle is pulled backward, water scours the inside of the pipe, removing any debris in the pipe. The debris pulled backward with the nozzle and water and vacuumed out of the manhole.  The cleaning process is also important for removing tree roots that may have penetrated the sewer pipe. This process is completed on every sewer line throughout the City.

During the cleaning process, moving air can vent into a home through the sanitary sewer service line. When air vents through the sewer line, water in the toilet bowl can bubble, surge, or even splash out of the bowl. The water that could come from an incident like this comes from the bowl itself.  The common causes of air venting into homes during sanitary sewer cleaning are: are movement from normal cleaning operations, the use of higher pressure needed when cleaning sanitary sewer lines located in a steep slope, sewer lines running close to buildings, a plugged roof vent, the size and complexity of a homes waste and ventilation system.  To minimize potential for water splashing out of your toilet bowl, it is best to keep the lid down.

Industrial Symbiosis

The City of Wenatchee is launching in partnership with the Center for Sustainable Infrastructure (CSI), and industrial symbiosis experts from Denmark’s Kalundborg Symbiosis—a globally recognized leader in circular economy solutions.  The City of Wenatchee will be exploring wastewater/industrial symbiosis opportunities between the City’s Wastewater Treatment Plant (WWTP) and the Chelan Douglas Port Authority’s developing craft brewery district and downtown businesses. The project aims to:

• Maximize water recycling to reduce overall consumption
• Recover energy and other resources from wastewater
• Reduce emissions from solids handling
• Lower reliance on local groundwater supplies
• Reduce production costs for local craft breweries

Why Participate?  Industrial symbiosis has been proven to deliver:

• Cost savings through resource efficiency and shared services
• Waste reduction by repurposing byproducts into valuable inputs
• Energy optimization through heat recovery and process integration

The Wenatchee Industrial Symbiosis planning effort is supported with funding from Washington’s Climate Commitment Act. The CCA supports Washington’s climate action efforts by putting cap-and-invest dollars to work reducing climate pollution, creating jobs, and improving public health. Information about the CCA is available at www.climate.wa.gov.

Wastewater Treatment Plant Improvements

The wastewater treatment plant is an essential part of keeping our community and environment safe.  To maintain this critical infrastructure and keep up with our growing community, the City continues to implement projects to replacing aging infrastructure and upgrade the wastewater treatment plant.  Here are a few projects that we are working on:

• The City is nearing completion of a new 380,000 gallon anaerobic digester.  This is the first phase of a round of improvements to replace old equipment and improve solids handling operations.  This project is expected to be completed by June 2025.
• A broken 8” concrete pipe caused a 36” pipe to fail.  These leaks caused settling issues along Worthen Street in front of the Wastewater Treatment Plant.  Emergency repair of the two pipes was completed in 2024.  The City is now working on repairing and restoring the landscaping along Worthen Street.  This project is expected to be completed by the end of 2025.

 Future Projects

The City is in the the design phase for a new administration building at the wastewater treatment plant and improvements to the anaerobic digesters. Construction of these two projects are planned for 2027 and 2027, respectively. 

Disposable Does Not Mean Flushable
As wastewater enters the treatment plant the garbage must be screened out to prevent plugs and pump failures. The material removed from the wastewater influent must then be bagged and hauled to the landfill. Sometimes the garbage that gets disposed in the sewer system does not make it to the treatment plant. The garbage gets stuck in the sewer lines and in lift station pumps, which can result in sanitary sewer overflows. A sanitary sewer overflow can result in the sewage backing up into houses or into the streets. This creates a large mess and is costly to clean up.

Note that even wipes that are labeled as "flushable" should not be flushed down the toilet. These wipes do not disperse quickly like toilet paper, they can stay intact all the way to the treatment plant.

• What Not To Flush Brochure (pdf)
• What Not To Flush Brochure - Spanish (pdf)

Disposal of Unused Medicines
When medicines are no longer needed it’s important to dispose of them properly to avoid harm to others or the environment.  The best way to dispose of unused medicines is to participate in a take-back program. 

Confluence Health participates in the National Prescription Drug Take-Back Program to provide a safe, convenient, and responsible means to dispose of prescription drugs.  Click here to view MedSafe drug collection and disposal receptacles.

The following links will provide additional information on how to dispose of unused medicines.

• FDA How to Dispose of Unused Medicines (pdf)
• Disposal of Unused Medicine: What You Should Know (link)

Visiting the Waste Water Treatment Plant

The City of Wenatchee welcomes guests to visit the Wastewater Treatment Plant by appointment. If you would like to schedule a tour, contact Wastewater Supervisor Mike Hodgson, mhodgson@wenatcheewa.gov.

• WWTP Tour Waiver Form (pdf)
• WWTP Tour Waiver Form_Spanish (pdf)
  

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