Moose Lake Star Gazette - Serving Carlton and Pine Counties Since 1895

By Natascha Watercott
Moose Lake Star-Gazette 

Sewer pond repair options discussed

 


At the February 6 Willow River City Council meeting, Mark Lundgren, environmental engineer at MSA Professional Services, briefly discussed options for repairing the sewer ponds that were damaged during last summer’s flooding. He explained that MSA had been hired to do a facility planning process for MPCA (Minnesota Pollution Control Agency). “Through this process, we were tasked with identifying a number of different options for how we can repair the ponds and hopefully prevent such a failure in the future,” he said.

MSA had developed four different options that will be presented to the MPCA for feedback as part of the facility planning process once the city reviewed and recommended one of the proposed facility plans. The four options had already been discussed at a prior meeting with Councilor Vicki Whitehouse and Becky Morris, secondary sewer and water operator, as well as John Herdegen, engineer for MSA Professional Services, and Lundgren.

The first option is to just re-line the existing secondary pond, which had failed completely. This is the most cost-effective option at $1 million. Lundgren said that he had been told by the MPCA that this option could not be implemented, however. Via phone interview, councilor Vicki Whitehouse explained that just re-lining the pond would probably not be enough to prevent the pond from failing again should there be another large flood. Similar to the dam, some kind of preventative improvements would be ideal.

The second option is to subcut (undercut) some of the material under the pond. This would involve raising up the pond floor and adding an intermediate pumping station. Lundgren noted that he, Herdegen, Morris and Whitehouse didn’t like this as a long-term option because it would require installing pumps and electricity.

The third option, which the city had indicated that it would like to investigate further, would involve building a new primary pond on the old primary pond’s footprint (foundation). “We think this is probably our best option, both in terms of being able to not be hugely expensive and get some elevation change and utilize most of the existing equipment,” explained Lundgren. The estimated cost for this option was $1.8 million. Lundgren also noted that this option had the best compromise of safety and capacity to protect against future flooding events.

The fourth option would involve putting a new primary pond in front of the existing primary pond, but would also require buying additional land. This option would cost an estimated $2.2 million, which Lundgren said was probably too expensive, but was also the best option for gaining elevation and protecting against future damage.

A fifth alternative was also presented. Lundgren said they could add what is called a cushion, two feet of sand underneath the liner, which would protect against hydraulic forces and prevent future failures. He noted that this option was also very expensive and probably something that was beyond what the city would want to look at for the project.

Funding for the project would be the same as the dam: the Homeland Security Emergency Management program would fund 75 percent of the cost to replace what was destroyed in the flood, and the city would have to find funding for the other 25 percent.

“They (MPCA) have indicated that they are willing to go with us and talk to Homeland Security, saying that ‘since we are not allowing the city to do the least costly option, your 75 percent needs to cover 75 percent of the recommended option.’ So we’re hoping that’s going to fly. MPCA is going to go in there with us and go to bat for us on that one,” said Lundgren.

He added that he believes the city can get the additional 25 percent of the cost through the Minnesota Public Facilities Authority (PFA), which, according to mn.gov, is a “multi-agency authority that provides municipal financing expertise … and makes low-interest loans and grants available to finance infrastructure that might otherwise be unaffordable to communities if they had to borrow money for the projects at market rates.”

As far as a timetable for the project, Lundgren said he is hoping to get the facility plan to the MPCA for expedited approval yet this month. It will then go to the various funding agencies, and the city will hopefully receive funding in March.

Asked if there would be an increase in the water and sewer bill, Lundgren responded that they are not far enough along yet and that it all depends on what kind of funding they can get.

Lundgren was also asked what was being done in terms of repairs to ensure that when future flooding events occur that this kind of damage doesn’t happen again. It was noted that in the last five years, there has been extensive damage done to the sewer ponds twice due to flooding. Some residents attending the meeting questioned if it might be worth the extra money to implement more extensive repairs.

“Every time we look at a project like this, it’s a balance between safety and cost, and if I was going to say what is the safest option, I would say let’s build that pond up front and let’s build it with a double liner and two feet of sand, but then you’re looking at $3 million,” said Lundgren.

“And we’re only getting paid Homeland Security funds for what was damaged,” Councilor Whitehouse added.

Ultimately, the council approved the waste water facility plan for alternative 3.

 

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