Tumwater projects: widening Old Highway 99, 79th Ave roundabout, Palermo Lagoon Dredging project

The Tumwater Public Works Committee recommended signing with contractors HDR Engineering, Inc. and Clearcreek Contractors for various city projects during a regular meeting last Thursday, April 6.

The Old Highway 99 and 79th Avenue Roundabout Project will be handled by HDR Engineering, Inc., while the Palermo Lagoon Dredging & Maintenance Project will be handled by Clearcreek Contractors.

Old Highway 99 and 79th Avenue Roundabout Project

Improvement projects for Old Highway 99 from 73 Avenue to 93 Avenue are included in the city’s 2036 Transportation Master Plan (TMP) published last 2016.

The TMP included widening Old Highway 99 to five lanes and intersection control at 79th Avenue.

“In 2016, the 2036 transportation master plan identified this as a need for intersection improvements. The current level of service at this intersection is significantly low,” Capital Projects Manager Don Carney said.

For this project, the consultant’s (HDR Engineering, Inc) scope of work includes the design of the Old Highway 99 and 79th Avenue Roundabout and a planned frontage in another location, which makes up their $735,000 consultant fee.

Palermo Lagoon Dredging & Maintenance Project

The Palermo Aeration Lagoon collects runoff from underground drainage systems and removes groundwater contaminants.

The U.S. Environmental Protection Agency built the Palermo Aeration Lagoon in 2000, and the system collects runoff from underground drainage systems and removes groundwater contaminants through aeration pumps. 

Over time, the lagoon has become saturated with sediments, decreasing the lagoon’s capacity and affecting the treatment processes, and this project will restore its normal functioning state.

Dan Smith, Director of Water Resources and Sustainability, presented in lieu of Operations Manager Steve Craig.

“We have large aerators that are attached to the Palermo Welfield and that serve to, basically, volatilize chemicals and evaporate them into the atmosphere prior to either entering our surface waters here downstream into the Deschutes River or into our drinking water from the Wellfield,” Smith said.

This maintenance project has a total cost of $126,650.

Both motions for the recommendation for the approval of the agreements and to authorize Mayor Debbie Sullivan to sign the documents were approved by the committee and will be forwarded to the city council to be finalized.