City of Little Falls votes to drill test holes in search of aquifer

Costs may be as high as $233,000 for first phase of project

By Terry LehrkeNews Editor

Karen Cavett and Jeff Liden showed the Little Falls City Council an image depicting the geological cross section of an area near the Little Falls/Morrison County Airport, that may contain an aquifer to provide a separate source of water for the city. The image shows a layer of clay above the aquifer which would protect it from contamination.

Karen Cavett and Jeff Liden showed the Little Falls City Council an image depicting the geological cross section of an area near the Little Falls/Morrison County Airport, that may contain an aquifer to provide a separate source of water for the city. The image shows a layer of clay above the aquifer which would protect it from contamination.

Test holes will soon be drilled near the Morrison County/Little Falls Airport, in search of an aquifer that could provide an alternative water source for the city of Little Falls.

The Council approved a bid from North Star Drilling in the amount of $233,195. However, if in the beginning stages of drilling, the area is found to be inadequate, the drilling would stop and the cost would be less.

Karen Cavett and Jeff Liden, engineers with Short Elliott Hendrickson (SEH) Inc. spoke with the Council about the process Monday.

Several years ago, Morrison County compiled geological atlas data. From that data, it was determined that an aquifer is located in and around the airport, and that it is separate from the aquifer in the city.

Cavett said the issue was an important one for the city. Currently, just one aquifer supplies all of the wells in the city, all located by City Hall and the water plant.

Test holes must be drilled to determine the kind of soil located in the area, as well as the quantity and quality of water and water flow.

“From the city’s perspective, we have to be comfortable before we award this bid,” said Public Works Director Jerry Lochner. “It’s a lot of money for the first phase.”

Cavett said the city had a wellhead protection plan done a few years ago. At that time, it was learned the coarse sand above the city’s current aquifer allowed for easy contamination from above and another water source was needed as a backup.

Cavett said an area near the south ballfield was looked at as well as an area near the city’s fire hall. But the ballfield is a long way away, she said, and while the area near the fire hall appeared to have potential for high water flow, it was still within the same confined aquifer as the water that comes into existing city wells.

“If the current well-field never became contaminated, it would be a great source,” she said.

The area near the airport is a separate aquifer, and confined, said Cavett. The clay surface in the area would keep contamination out. “It’s what you look for,” she said.

Liden said in theory, according to the geology that can be accessed from reading books about wells, the area appears to be promising.

However, the next step is to test drill to shore up an analysis of the site.

“Geology by poking holes is better than paper,” he said. “Your current aquifer is considered vulnerable by wellhead protection technology, but has been in use since 1905 without a problem.”

“The sky is not falling,” he said, but said it would be prudent for the city to take steps to find an alternate water source.

Part of the test drilling program would be to drill a couple of holes by the fire hall site, in addition to the airport site. If the fire hall site pans out, Liden said steps can be taken to secure it for a future well site.

Cavett said that with the current confined aquifer, the city is losing capacity slowly. Over the years, oxidation of minerals occurs. While wells can be cleaned a few times and Little Falls’ wells have been cleaned many times, Cavett said it will get to a point where the well won’t recharge. “That’s what is happening to individual wells,” she said.

“At some point, you’re not going to be able to rehab that,” said Liden. He said the city might be able to have replacement wells drilled, but there is still a vulnerability to the current water supply.

“This is a big investment to secure a source of water, but in the interests of Little Falls, it’s not that big of an investment to have a good supply of water,” said Liden.

Funds for the project will come from the water and improvement fund.

“It’s comforting to know that it may not get to the $233,000 level, said Council Member Greg Zylka, noting that if it’s a dry hole, the drilling would stop. “Maybe we’ll get lucky and hit a hot spot right away.”

 

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