The Hutchinson City Council on Tuesday approved applying for two separate low-interest loans from the state to address issues related to aging water and sewer infrastructure in the city.

One will help to replace the last five of nearly three dozen sewer lift stations installed around the city in the 1970s and 80s, said Public Works Director Brian Clennan, as well as upgrade deteriorating grit removal equipment at the city’s wastewater treatment plant.

The other will start moving the city toward a goal of replacing more than 3 miles per year of failing waterlines around the city though that ultimate goal is still several years away.

If awarded, the loans for sewer-related work will top $3.57 million, while the waterline work is more than $1.2 million.If granted, Clennan advised the council, the 20-year loans would be at 2%, which is about 60% of the current market rate. Water and sewer system revenues would pay the loans.

“The other reason is the waterline project could qualify for partial principal forgiveness if there’s money left, but all projects are ranked, so we’re not sure if we’d be eligible for some forgiveness,” he said.

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During a public hearing on the loan applications, Clennan provided details about the individual systems and their challenges and a broader overview of the systems.

The city owns and operates 33 lift stations on its sanitary sewer collection system. Sewer systems usually use gravity flow, but because Hutchinson is so flat, there are locations where the wastewater has to be mechanically lifted to a higher elevation to create flow.

Since their original construction, the city has already converted 28 wells from wet well-mounted lift stations to submersible-type non-clogging pumps.

The improvements include new bypass connections, manual transfer switches to operate a portable generator and wet-well cleaning systems to control grease.

"Failure of a lift station could result in significant backup on residences or businesses,” Clennan said. “They’re really a critical piece of infrastructure for the community to function properly.”

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Lift stations being replaced include:

A separate wastewater system project is at the headworks of the city’s treatment plant, where equipment settles out and removes grit from the wastewater before it goes through the system, prolonging equipment life and making the plant more efficient. Grit buildup downstream could also lead to ammonia buildup, violating the city’s operating permits, Clennan said.

The system, installed in the 80s, includes diffusers that release bubbles in the wastewater, which help make the grit fall out. What settles in the bottom is augured out to a “cyclone pump,” which spins it and further separates it. They spread the resulting slurry on fields and haul the grit to the landfill.

All that equipment and some piping will be replaced at an estimated cost of $820,000. The plant is designed to handle 8.3 million gallons a day but is averaging 4 to 5 million gallons, Clennan said, so there’s still room to grow.

On the waterline side, the city wants to replace 1.3 miles of six-inch cast iron pipe, primarily in neighborhoods between K-61 and Town Street and First and Ninth avenues.

The city needs to replace 3.3 miles annually, Clennan said, which is about 1% of the line total but will build up to that over the next four years as funds accumulate from rate increases approved by the council earlier this year.

Data Clennan shared with the council showed around 5% of the city's 300-plus miles of waterline was installed from 1900 to 1909. That pipe accounts for about 8% of all waterline breaks.

However, pipe installed in the 1950s and 60s, about 28% of the city's waterline total, accounts for 47% of all breaks.

“I heard all the good steel went to building tanks in the 40s, so the cast iron that went into waterlines is not as high quality,” Clennan explained.

Some 62% of the city’s waterline system is iron pipe, but it accounts for 94% of the breaks. Also, based on size, 6-inch pipe makes up 38% of the piping, but accounts for 80% of breaks.

All the pipe the project will replace was installed between 1938 and 1968, Clennan said. PVC pipe will replace it.

Besides approving resolutions authorizing staff to submit applications to the Kansas Water Supply and Kansas Water Pollution Control revolving funds, the council Tuesday approved a preliminary design agreement with Burns and McDonell of Wichita for $136,974.

The company was the only one of five invited to bid who submitted a proposal, Clennan said, but it “was very thorough, and they have completed several projects at the wastewater treatment plant.”

City staff suggest using a design-build process to shorten the construction timeline by at least six months, rather than a design-bid-build format, but will come back to the council after design completion to finalize the process.