Sewer plant renovation OK'd

The Kalispell City Council on Monday agreed to proceed with a renovation of the primary digester tank at the wastewater treatment plant, finalizing an $863,188 contract with Swank Enterprises.

Hired to design and oversee the project, Craig Caprara of HDR Engineering said he worked through some questions he and several city council members had about the internal coatings Swank Enterprises planned to use for the project.

Special coatings protect the 50-by-32-foot concrete digester tank and its concrete and foam lid from methane gas and other corrosive elements generated by the biological solids reduction process inside.

“The coating they proposed wasn’t one of the approved ones we had. We provided them with a list and they evaluated those and agreed they could use an approved coating for the price in their bid,” Caprara said.

“That alleviated the concerns we had, and we don’t see any reason for you to not sign a contract with Swank Enterprises.”

Council member Tim Kluesner said another concern with the project was the cost, but he ultimately joined the rest of the city council to vote to proceed.

“My biggest catch on all this is the fact that we budgeted $865,000 and now we pay $1.27 million. We’re paying 30 percent more than what we thought this project would cost,” Kluesner said.

The renovation’s cost grew by nearly $200,000 from preliminary cost estimates as extra work and design changes were added during final engineering.

Kalispell officials plan to pay for the project with a loan from the Montana State Revolving Fund. Construction costs, taxes, engineering services, bond counsel costs and a required 15 percent contingency could push the total bond amount to as high as $1.27 million.

Caprara stressed some of those costs won’t materialize. The 15 percent contingency is an item required by the state and likely won’t be needed.

“For a project like this, typically we don’t see more than three to five percent contingency at most, so I would expect you won’t spend anywhere close to that on this project,” Caprara said.

Council member Phil Guiffrida III questioned if two separate bid items that were not awarded because they did not come in under budget will later lead to extra costs that would be avoidable if they are done now.

Those items would replace various piping components on and around the digester tank. Public Works Director Susie Turner they can be done  later and will be brought back as capital improvement projects next fiscal year.

The approved project will replace the digester tank’s lid, install a new mixer and foam separator and relocate a temperature transmitter, among other work. A secondary digester will go online while the primary digester is down.

Construction is planned to start this spring and take 150 days to complete. The primary digester renovation is one of several projects public works staffers hope to complete this year at the wastewater treatment plant.

The others would replace a failing belt-driven sludge press with a new screw-driven sludge press and replace 11,000 square feet of leaky roof liner over the plant’s control room.

Reporter Tom Lotshaw may be reached at 758-4483 or by email at tlotshaw@dailyinterlake.com.