Committee endorses contract for design of Trosper Road sewer extension in Tumwater

The Tumwater Public Works Committee endorsed a $578,060 contract with consulting engineers Gray & Osborne Inc. to design the extension of the sewer along Trosper Road. 

The project will extend the sewer line roughly 6,000 feet to the west. Currently, the line terminates at Lambskin Street before routing north toward the Trosper Ridge community. 

The public works committee made the decision at a meeting on June 4.

The extension will be funded using a $5.25 million Washington State Department of Ecology loan that the committee endorsed on April 23, and the Tumwater City Council approved on May 5 through its consent calendar. The 30-year loan carries an interest rate of 2.7 percent. 

Tyle Zuchowski, Deputy Director of the Tumwater Water Resources & Sustainability Department, said the primary driver of the project is to protect and improve groundwater in the area.

There are known water quality issues in nearby Percival Creek, particularly with fecal coliform content and nitrogen levels. 

The project will also serve as a pilot case study to help the city develop its septic-to-sewer conversion program. 

Zuchowski said Gray & Osborne was selected from seven companies that bid for the project. 

The firm’s contract includes project management, topographic surveys, right-of-way mapping, geotechnical investigations, utility coordination, stakeholder engagement, design and permitting. 

Zuchowski said staff would return to council once the project is ready to advance to construction. He added he is hopeful construction could start next summer.