Engineer makes recommendations for water treatment, spillways

Construction of a new, pressurized-sand water treatment plant for the City of Holton and spillway repairs at two city-owned lakes would likely be costly, an engineer told the Holton City Commission last Tuesday.

“Whatever you do, you’re going to have to spend some money,” Don Hellar, an engineer with the Great Bend-based Evans-Bierly-Hutchinson and Associates (EBH) engineering firm, told commission­ers about making improvements at the water plant and the lakes.

Hellar did not present commis­sioners with cost estimates for work options during Tuesday’s meeting, held a day later than usual due to the Labor Day holiday, al­though he noted some of the op­tions could have million-dollar price tags attached. He agreed to meet with commissioners in early October to discuss pricing options for possible future projects.

In addition to improvements at the water plant and spillway repairs at Prairie Lake, two topics of recent commission discussion on how to spend the city’s capital improve­ment funds, the rain-damaged spillway at Elkhorn Lake is now in need of repair, commissioners noted in July. At that time, they ap­proved a $16,500 bid from EBH for engineering work on those three projects.

Hellar’s initial report to the commission suggested that the city could build an entirely new, pressurized-sand treatment plant that would adequately treat water from two city-owned wells located north of Prairie Lake, since the ex­isting plant that treats water from that lake is “old and does not meet how we’d design things nowa­days.”

The city currently gets the majority of its water supply from Public Wholesale Water Supply District 18, which treats water from Banner Creek Reservoir for sale to the city and to Jackson County Rural Water District 3.

Commissioners have expressed a desire to “rehab” the city’s water plant as a backup for times that Wholesale 18’s plant goes offline, Holton City Manager Kerwin McKee said.

However, the city’s existing water plant — built in 1947 and given its most recent “rehab” in 1985 — is incapable of running at low speeds, McKee said. A pressurized-sand water treatment plant, he added, would be able to run at lower speeds and allow the city to treat water from the city’s two wells located northeast of the city for sale to city utility customers at a rate cheaper than what the city pays Wholesale 18 for water.

“It would also be cheaper than trying to rehab the old plant,” McKee added.

Building a new plant complete with a new clarifier and filters needed to clean Prairie Lake water for city utility customers, however, would likely cost the city about $2 million, Hellar said. Add on a new line to bring water from the lake to the plant and repairs to the lake’s pump house, “we’re up to $3 mil­lion and then some,” he added.

On the other hand, he suggested the city could continue to purchase water from Wholesale 18 and cease using Prairie Lake as a water supply source but use the new treatment plant to treat water from the two wells, which he said are “in good shape” and “will supply all the water that you need.”

Hellar proposed the construction of a small plant that would remove iron and manganese from the well water, noting a ballpark estimate of $1.25 million for the construction.

“We’re just trying to look at supplementing the water we’re get­ting from Public Wholesale 18,” he told commissioners. “And if Public Wholesale 18 is down, you’ve got a supply of water that you can oper­ate with.”

Those wells, Holton Water and Sewer Superintendent Dennis Ash­craft said, can pump between 400 to 500 gallons per minute at their maximum capacity, or up to 500,000 gallons of water per day. Conversely, Commissioner Tim Morris noted, the city buys more than 8.1 million gallons of water from Wholesale 18 per month.

Concerning Elkhorn Lake, where city officials noted that runoff from rain into the lake had caused “a potential safety issue,” Hellar noted the primary spillway is not the con­crete culvert at the north end of the lake where the road is closed due to that particular safety issue. Rather, it is a concrete box located within the lake where a spillway outlet could be unplugged to remove ex­cess water.

“My guess is that it’s clogged up by mud,” he told commissioners. “It probably didn’t happen with just one flood overnight. It probably happened over time.”

The culvert, he said, is the lake’s “secondary spillway,” and repairing it is “not going to be a huge help, but it will let what’s under that road dry up.” The culvert itself is washed out underneath the con­crete, which is “hanging on by re­bar,” he added, and repairing it re­quires that the area dries out.

Hellar did not provide estimates on how to repair the spillways at either Elkhorn or Prairie lakes, but instead tried to give commissioners an idea what repairing the latter might cost. A similar structure at Anthony in south central Kansas cost $2 million to repair, he said, and Holton’s spillway is about half as long as the Anthony spillway.

Furthermore, Hellar said he had spoken with a spillway “restoration specialist” about repairing the Prairie Lake spillway by drilling holes in the “big cracks,” filling them with epoxy and patching them. The specialist, he said, gave an estimate in the “$25,000 to $30,000 range, but I think it’ll be a little bit more than that.”

The “chute” that takes water down from the Prairie Lake spillway is in far worse shape, Hellar told commis­sioners, and repairing that could also cost “quite a bit of money,” but he added that “for now, I do not plan to do anything with that.”

McKee suggested that if the city was going to spend $1 million or more repairing the Prairie Lake spillway, dredging the lake should also be considered as the lake is “silted in considerably.” Ashcraft said dredging was “proba­bly” not necessary, since the city’s aim is to “just repair what we have and extend the life of the lake as long as we can.”

Whatever the work plan, Hellar told commissioners that EBH is “trying to make efficient use of your money,” and noted that there were several options for paying for the work. Rural Development could offer a loan with an interest rate of 2.75 percent, he said, and interest rates for municipal bonds are “al­most nothing right now.”

“Now is a pretty good time to be doing something,” Hellar told commissioners, noting that he would return to commissioners with some cost estimates in early October.