TD readies for plant overhaul

“This is really unique — on the cutting edge,” said Tom Paul, general manager of Mortenson, a company based in Kirkland, Wash. “We’re kind of writing the book on how it goes.”

Preston Van Meter, market director with Kennedy/Jenks, said the biggest challenge facing the team has been how to plan for construction while the First Street wastewater plant remains operational.

“We’ve virtually builtthe plant multiple times so that we could see which is the best design effort,” he said.

Dave Anderson, public works director for the City of The Dalles, said the normal process for a project is to have an engineer design plans that are later interpreted by the contractor, which often results in a lot of changes on the ground.

“Early in 2013 the city council gave us permission to use this alternative delivery system,” he said.

Instead of the traditional bid system, the city chose to invite proposals from design-build teams and Mortenson and Kennedy/Jenks were selected because of their experience with a $240 million project in Washington and another in Colorado.

The two companies have been working together for more than three years, according to Paul.

Van Meter said plans designed without input from a contractor have a “series of assumptions” that sometimes don’t work.

“This allows us to put everything on the table with the contractor who will be doing the building,” he said. “We look at the total cost and how to maximize the value.”

By reducing the number of changes that will need to be made, Van Meter said the level of risk is reduced and so is the expenditure.

“We’re driving a lot of that out with this process,” he said.

Anderson said the reduction of change orders during the project have been shown to save an average of 6 percent in costs across the nation.

“It’s really about getting the most value for the dollars we’re spending,” he said.

Through a series of workshops with city officials, the design-build team is now in the process of evaluating what needs to be done at the plant to correct deficiencies and replace aging equipment.

They have also been performing flow tests and determining how well the existing system is functioning to identify any potential problems.

One of the problems that needs to be corrected is the flow level of water passing through the system, said Anderson.

He said the city is not meeting the state Department of Environmental Quality’s flow guidelines for wastewater and needs to come into compliance.

If a component of the plant were to fail, Paul said current equipment would be unable to handle the flow needed to continue operating the system safety and effectively.

Once Mortenson and Kennedy/Jenks have finalized their plans, sometime in early July, the city will confer with regulatory agencies to make sure the changes are in compliance with government guidelines.

By the time construction begins at the end of October or first part of November, Anderson said any snarls should have been worked out.

Once phase one is completed, planning will begin for the second phase, which will cost $3.38 million and focus on modernizing the treatment process. That work is expected to begin in 2017 and be completed two years later.

The final phase of improvements, at $4.76 million, will improve the collection system to meet future population growth needs, as well as upgrade the administration building.

Construction begins in 2019 and is expected to wind up in 2021.