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Improvement projects

Find information about capital improvement projects at South Plant.

To ensure South Plant keeps pace with regional growth and continues to meet regulatory requirements, it is important that we maintain and update our infrastructure through capital improvement projects. These improvements also help us increase efficiency, improve system reliability, and protect community health and the environment.

Capital projects

Biogas and heat system improvements

  • The wastewater treatment process produces gasses. Our biogas system captures these gases and converts them into energy for heat and other uses.   
  • Work will occur through 2024. 

Biogas from the digesters at South Plant can be sent to the co-generation system to be converted into electricity and heat.

Biogas from the digesters at South Plant can be sent to the co-generation system to be converted into electricity and heat. 

 


Influent pump station seismic upgrades – 2027

  • Living in the Pacific Northwest puts us at risk of large seismic events. These upgrades will help protect the plant so that wastewater treatment processes can continue even in the event of an earthquake.   
  • Work will occur through 2027

 



Odor control modifications at primary, secondary, and dissolved air flotation thickeners – 2022

  • We want to be good neighbors. This project is allowing us to modify and refurbish our odor control system to reduce the amount of odor that escapes the plant   
  • Work will occur through 2022. 

 


Dewatering building truck loading bay ventilation improvements – 2025

  • We want to keep our workers safe and reduce smells escaping the plant. This project will improve ventilation and reduce ammonia odors on-site and for neighbors.  
  • Work will occur through 2025. 

 


Essential services standby generator replacement – 2024

  • This project is replacing a generator that is at the end of its useful life. We want to be prepared in the event of a power loss to run essential equipment so that you can keep flushing your toilet.
  • Work will occur through 2024. 

 


Fire control panel upgrade – 2023

  • We are constantly working to ensure compliance with safety and health codes.   
  • Work will occur through 2023. 

 



Loop Compost Pilot – 2023

  • We are testing out ways to safely produce Class A biosolids from wastewater for use in public spaces and home gardens. Currently, WTD produces Class B biosolids that require permits and are used on commercial farms and forests.
  • Work will occur through 2023. 

Loop trucks—you may recognize them driving around our region

Loop trucks—you may recognize them driving around our region.  

 


Dissolved air flotation tank rehabilitation – 2026

  • Dissolved air flotation tanks are used to remove grease and oil from wastewater. Some components in our tanks have aged and require rehabilitation or replacement.
  • Work will occur through 2026. 
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