Budget climbs for odor control upgrades at Cedar Rapids sewage facility

Illinois company is low bidder for $6.59 million project

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CEDAR RAPIDS — Cedar Rapids is primed to move forward on a major odor control upgrade at the city’s sewage treatment plant, which has seen budget estimates balloon in the past 17 months.

Cedar Rapids City Council is being asked when it meets Tuesday to award a $6.59 million contract to Williams Bros. Construction of Peoria, Illinois, to upgrade the Water Pollution Control facility.

The meeting takes place at noon at City Hall, 101 First St. SE. The item is on the council’s consent agenda, which means discussion about the contract is not likely to take place.

The cost of the project is up from a staff estimate of $5.2 million earlier this year and $3.9 million forecast in March 2015.

“The change is based on the technology we plan to implement,” said Steve Hershner, Cedar Rapids utilities director. “It is very difficult to project this type of work, when you are talking about an odor control system that’s not like any other odor control system.”

The 2015 estimate was a preliminary “best guess” early in the project, Hershner said. More recently, quotes for material and equipment were about $400,000 higher than the latest city staff estimate and the overall project difficulty and market conditions were underestimated, according to city documents.

The Williams bid was the lowest of four the city received, which also included submissions of $6.8 million, $6.9 million and $7.6 million.

The sewage treatment plant treats organic waste from about 180,000 metro area residents, and the odor control system is approaching 20 years old.

Often the stink isn’t noticeable unless passing by the plant at 7825 Bertram Road SE, but it can get smelly at times depending on the weather conditions. The worst of the whiffs tend to drift toward Bertram, which is typically down wind of the plant, neighbors said.

“Maybe three times a week, and always in the morning, you can smell it — it’s like rotten eggs,” said Libberty Hines, 36, of Bertram. But, she added, it’s really not that bad.

Ellen Heck, 73, who lives in a neighborhood off Highway 13, said the smell can be strong at times, but it typically is gone within an hour. Volunteers and staff at the nearby Indian Creek Nature Center said campers occasionally complain about the smell, but on the whole it isn’t bothersome.

Still, they said they are glad to hear improvements are in the works.

The new odor control plan budgets the costs over the next three years with completion by early 2019, Hershner said. The project involves repairing and upgrading the odor controls and adding capacity.

Consultant CH2M Hill Engineers was hired for $590,465 in 2014 to engineer the new project after earlier evaluating the systems and recommending optimizations.

The facility has two bioscrubbers, which use bacteria grown on lava rocks to remove odor-causing compounds, such as hydrogen sulfide, at a rate of about 90,000 cubic feet of air per minute. The project is to see the addition of two new biotowers each with a capacity to scrub 25,000 cubic feet of air per minute. The added capacity is to maintain the plant’s ability to keep up with odor control when a unit is down.

The upcoming project also includes replacing the lava rocks, repairing the bioscrubber vessels, replacing and repairing ductwork and fans, improving ventilation of the sludge storage tank and demolishing a backup chemical scrubber.

“We will see an additional level of odor control when the newer units are online,” Hershner said. “Yes, at the end of this project, we should see some overall improvements.”

The odor can’t be eliminated entirely, Hershner said. External factors, such as meteorological conditions, play a major role in when it stinks and when it doesn’t and are beyond the plant’s control.

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