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Wastewater System

Trenchless Technology

Wastewater is carried from homes and businesses by pipes and pump stations before it's treated at wastewater treatment plants and released into Commencement Bay.
City of Tacoma Wastewater Management operates two treatment plants, cleans billions of gallons of wastewater every year and serves hundreds of thousands of customers. Learn more about how we move wastewater through the City.


Pump Stations

Pump stations move the wastewater flow from one area to another through sewer lines.  The City of Tacoma operates 50 pump stations.  Help us keep the system flowing by not flushing certain types of items.  These items can cause pump stations to fail, which can lead to sewer backups.

Tacoma's Treatment Plants

To serve our more than 90,000 customers, the City operates two award-winning wastewater treatment plants -Central Wastewater Treatment Plant and North End Wastewater Treatment Plant.

Both treatment plants are considered state of the art, but operate in very different ways.  The Central Wastewater Treatment Plant, located on the Tideflats along the Puyallup River, uses high purity oxygen and "good" bacteria to remove organics from wastewater.  The North End Wastewater Treatment Plant, in Mason Gulch off Ruston Way, uses chemicals to remove the organics and a filter with "good" bacteria to treat the wastewater before it enters Puget Sound.

Every year we lead hundreds of students (middle school through college) and community groups through our wastewater treatment plants to show how they are an integral part of recycling our resources and keeping our water clean. To set up a group tour, call the Central Wastewater Treatment Plant at (253) 502-2176.


Improvement Projects

We're proud of Tacoma's historic buildings and appreciate when property owners restore them, preserving the splendor of the old while adding the technology and safety of today.  While the wastewater system isn't as grand as our brick buildings and historic homes, it's just as important for us to improve our infrastructure to keep it operating safely and efficiently. 

Some of our infrastructure is 100 years old and needs to be replaced.  In the past, we repaired pipes only when a failure occurred, but in 1995, the City began an aggressive Inflow and Infiltration Program.  At a cost of $4 million a year, we began upgrading or replacing old sewer pipes that allowed groundwater and surface water to seep into the sewer system through cracked and leaky joints. 

To upgrade old sewer pipes, we use trenchless technology, allowing us in many cases to replace pipes without cutting into the streets.  This construction method reduces time-consuming detours and costly road reconstruction.