Wastewater Management

Tacoma operates 50 pump stations that move wastewater through sewer lines from one area to another. To help keep the system functioning, avoid flushing items that can cause pump station failures and lead to sewer backups.

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

Central Wastewater Treatment Plant is one of the most technologically advanced facilities in the nation, serving Tacoma, Fife, Fircrest, and parts of unincorporated Pierce County – about 20,000 customers in total.

The plant recycles 100% of its processed biosolids into award-winning TAGRO Mix and Potting Soil products, helping gardens thrive across the region.

Among its innovative features is a dual digestion system, which produces Class A exceptional quality biosolids. The plant also has a peak flow treatment facility that can quickly handle high volumes of water during heavy storms, reducing the risk of sewage overflows. During major storm events, the plant can process over 130 million gallons of wastewater per day.

As an integral part of Tacoma’s growth, the plant underwent a major upgrade in 2008. In 2014, the Pierce County Flood Control Zone District Board invested $6 million to build a floodwall around the facility, protecting it from potential flood risks. This critical project was selected to prevent untreated wastewater from entering local waterways, which could have widespread impacts on businesses, recreation, and wildlife.

North End Wastewater Treatment Plant utilizes chemicals and filters with beneficial bacteria to treat wastewater before it enters Puget Sound and is recognized as one of the most innovative facilities in the nation. Its cutting-edge, cost-saving approach earned a prestigious national award from Rutgers University for improving productivity, efficiency, and cost savings through creative problem-solving.

Unlike conventional treatment plants, the North End facility’s highly efficient process eliminates the need for large tanks and extra land, significantly reducing construction costs. The plant’s upgrades, completed between 1989 and 1997, cost $10 million—far below the typical $38 million for a conventional system. This facility continues to play a vital role in Tacoma’s development.

We offer educational tours for students and community groups to show how wastewater treatment is essential to water recycling and environmental protection.

To schedule a group tour, contact the Central Wastewater Treatment Plant

Tacoma’s wastewater infrastructure, with some components over 100 years old, is continuously being upgraded to ensure safety and efficiency. Since 1995, the City has implemented an aggressive Inflow and Infiltration Program, investing $4 million annually to replace or repair old pipes that allow groundwater to seep into the system. We use trenchless technology to replace aging pipes, minimizing street disruptions, reducing detours, and saving on road reconstruction costs.

The City of Tacoma’s Environmental Services Department has implemented Environmental and Sustainability Management Systems (ESMS) at the Central Wastewater Treatment Plant and Solid Waste Management to enhance environmental performance and sustainability.

What is an ESMS?

An Environmental and Sustainability Management System (ESMS) is a structured approach designed to help organizations:

• Reduce environmental impacts
• Increase sustainability
• Ensure compliance with environmental regulations
• Integrate environmental considerations into daily operations

Tacoma’s Environmental Services Department developed its ESMS framework using the International Organization of Standardization (ISO) 14001 Standard, a globally recognized model for effective environmental management.

To reinforce our commitment, Environmental Services has issued an Environmental Policy outlining our goals for continuous improvement.

Significant Environmental Aspects & Goals

The ESMS requires a thorough evaluation of facility operations to identify key environmental impacts. The following significant environmental aspects were identified at the Central Wastewater Treatment Plant and North End Treatment Plant, with goals set for improvement:

• Greenhouse Gas Emissions – Convert 40% of biogas emissions to fuel
• Greenhouse Gas Emissions – Optimize digester gas system
• Greenhouse Gas Emissions – Reduce air emissions and improve aerobic digester (quad) operations
• Raw Materials – Upgrade North End Treatment Plant trickling filter and chlorine system

At the Solid Waste Management Division, additional environmental aspects were identified, with specific goals to reduce impacts:

• Air Emissions – Reduce greenhouse gas emissions
• Potential Spills – Reduce the number of spills
• Fire Potential – Decrease solid waste trailer fires and reduce firefighting discharges into the storm system
• Resource Consumption – Minimize contamination in the residential recycling stream

Through the ESMS, Tacoma continues to advance environmental stewardship, sustainability, and operational excellence.

For more information, contact Judith Scott

Tacoma, originally named Commencement City, was founded in 1868 by General Morton McCarver, who saw the city’s deep harbor and timber resources as key to its future. By 1873, Tacoma was selected as the terminus of the Northern Pacific Railroad, setting the stage for its development.

Tacoma’s Sewer System: The first community sewers were built in Tacoma in 1880, designed to carry waste directly to Commencement Bay. As the city grew, industrial and population expansion overwhelmed natural systems, causing significant pollution.

By the 1940s, the City recognized the need to address pollution from sewer discharges. In 1944, voters approved a $3 million bond for essential sewer construction and a wastewater treatment plant to serve central, southern, and eastern Tacoma. Main sewer construction began in 1949.

Long-Term Improvements: In 1955, the City developed a long-range plan for sewage and drainage improvements, beginning with separating surface water from wastewater systems. This effort, initiated in the late 1950s, prevented raw sewage from discharging into storm drains. By 1993, all storm drains were disconnected from the sewer system.In 1995, Tacoma launched the Inflow and Infiltration program, investing $4 million annually to upgrade old pipes and prevent groundwater from seeping into the system. This program continues today, removing private roof drains from the sewer system identified through smoke tests.

Tacoma has made tremendous progress since its early days of sewer overflows. Today, the Wastewater and Surface Water Management divisions play a crucial role in the cleanup and restoration of local waterways and watersheds. The City continues to champion the protection of one of the Northwest’s most valuable natural resources, contributing to the region’s quality of life.