City of The Dalles, OR

Wastewater & Stormwater


Poster Think Before You Flush, same text on webpageTHINK BEFORE YOU FLUSH

Toilet paper and human waste are the only two things that should be flushed.

Do not flush these items:
            • Cotton swabs and makeup pads
            • Tampons, maxi pads & their applicators/wrappers
            • Cleaning/Flushable Wipes
            • Paper towels and cloth towels
            • Diapers and Underwear
Removing clogs in your sewer pipes is your responsibility.


The City cleans about 2 million gallons per day before it goes into the Columbia River.

100 miles of sewer lines are maintained by only 9 certified operators. The wastewater treatment plant has only 7 certified operators. Help avoid preventable clogs that take them away from other critical tasks. Help us clean up wastewater before it goes into the sewer system. Think before you flush.

Wipes are the biggest cause of sewer backups in The Dalles. Even if the package says "flushable" they should never be flushed. Put dirty wipes in the trash.

The purpose of sanitary sewer system is to funnel sewage to the wastewater treatment plant. The Wastewater Collections Division operates and maintains the sanitary sewer system.  The system consists of sanitary sewer mains, debris interceptors and lift stations. A well maintained system protects human health and protects the environment.  Division duties include:

  • video inspections,
  • mechanical and chemical treatment of sewer clogs,
  • routine lift station maintenance,
  • system repair and replacement.

The Dalles RV Dump Station

Help us avoid costly sewer back-ups

Think Before You Flush

Wipes Clog Pipes and Pumps Video
(Used with permission)

Think Before You Wash

Food service establishment guide for grease interceptor compliance

Pretreatment of wastewater guide for industrial users

Help us keep hazardous waste out of the sewer and local waterways

Protect Yourself from Mercury

Protejase del Mercurio

Wastewater treatment preserves the beauty and bounty of the Columbia River. The Wastewater Treatment Plant operates under contract by Jacobs. Public Works staff provides administrative oversight for the plant. The City treats sewage to protect human health through disinfection. Treatment also removes debris and chemicals that can harm plants, fish and animals. The water discharged must meet stringent Oregon Department of Environmental Quality regulations.

The purpose of storm water management is to protect property and the environment. The Wastewater Collections Division also operates and maintains the stormwater conveyance systems. Water collected by the system is not treated before discharge into the Columbia River. We ask citizens to ensure that only rain goes down the drain. Together we can protect human health and the environment.

Keep sanitary sewer and stormwater collection systems separated

For more information on the Wastewater System contact Public Works.