Council OKs $19.89M sewer plant
An architectural rending shows the design for the City of Whitefish's new wastewater treatment plant. The architect is Comma-Q Architecture of Bozeman.
An architectural rending shows the design for the City of Whitefish's new wastewater treatment plant. The architect is Comma-Q Architecture of Bozeman.
Whitefish is moving forward with a major project to construct a new wastewater treatment plant at a cost of $19.89 million.
City Council last week unanimously approved awarding the plant construction project to Swank Enterprises. Construction. Construction of the new wastewater treatment plant is set to begin in the spring and it’s expected to be operational in the summer of 2021.
The wastewater plant has been designed to bring the city’s plant into compliance with state standards and to serve the city through 2035 or a population of 20,000.
Engineering estimates for the project had put the cost at $16.6 million, however, bids received on the project this fall put the cost above that estimate by 22% to 39%. Swank bid the project at $20.37 million and Dick Anderson Construction submitted a bid of $23.1 million.
Public Works Director Craig Workman explained the difference between the estimate and the bid figures.
“The assessment of the bidding process indicates that several factors may have impacted the bid including limited number of bidders, other similarly-sized projects bidding at the same time, this is an extremely complex project, the use of proprietary technology may have discouraged bidders, impact of the American Iron and Steel requirements, expensive dirt work and the involved control system,” Workman said.
He noted that Swank Enterprises spent a lot of time investigating the project so his department felt comfortable recommending their bid for the project and that it is a representation of the true cost of the project given the current bidding climate.
Following the bid process, the Public Works Department began working with engineers on “value engineering” to identify about $475,000 in savings from work that could be eliminated from the construction bid. Thus, ending at a final contract cost of $19.89 million.
The bulk of the savings — about $420,000 — came by eliminating work from the contract largely related to decommissioning of the current wastewater treatment plant. The related work is expected to be completed by city crews at a reduced cost from what was bid.
Other savings of about $54,000 came in making modifications to a portion of the project.
In 2012, Whitefish was issued an administrative order from the state Department of Environmental Quality as a result of several violations of the city’s wastewater collection and treatment system. The new plant will bring the city into compliance with updated requirements for removal of ammonia, nitrogen and phosphorous. The city had been completing projects to deal with the issue since and in 2016 submitted a report to the DEQ detailing plans for a new treatment plant.
Plans for the new wastewater treatment plant were completed in September and the city received final approval from DEQ in October.
Workman said the city is ready to begin the process of constructing a new wastewater treatment plant.
“The plant that has been designed and bid is the most cost-effective solution to regain compliance with DEQ and will serve the city for decades to come,” he said.
Though bids for construction of the project came in higher than projected, the city is still estimating a savings of $2.29 million in capital costs by selecting the Nereda system over another brand for use in the wastewater plant.
The city in 2018 selected a biological wastewater treatment technology for its new plant that will use a sequencing batch reactor, which is a type of activated sludge plant with multiple unit processes contained within the same concrete basin that saves space and cost.
The Nereda system requires much smaller basins to operate the sequencing batch reactor system, according to Workman, offering a significant reduction in the overall footprint of the plant. This means that savings were found by factoring in less concrete and foundation expense.
The Nereda system is also projected to have lower operating costs due to lower energy requirements.
“In the most practical terms, this technology will allow us to build smaller basins which are less than one-third the size of more traditional [sequencing batch reactors] basins, allowing for construction savings, reduced energy consumption, and ore effective use of land at the treatment plant site,” Workman said.
Related to the wastewater plant upgrade, since 2011, the city has invested in reducing infiltration of groundwater into the city’s wastewater system. Extraneous flow, known as infiltration and inflow, reduces the performance of the city’s wastewater treatment facility.
The city’s fiscal year 2020 budget includes $110,000 to continue to work on the issue.