MITCHELL — When a casual observer sees progress on the city of Mitchell’s south wastewater treatment complex by the Mitchell Regional Landfill, they see men working in muddy conditions and concrete foundations being poured and prefabricated concrete walls being moved by cranes.
For Bryan Garrison, it’s life.
Garrison, 63, has worked on such jobs sites for most of his adult life in over 30 U.S. states.
“I think Mitchell has just as much going for it as any place. I mean, when they get done cleaning the lake, y'all are going to have to put up road blocks,” Garrison said.
Garrison, who is the engineering inspector for Mitchell’s south wastewater treatment complex, believes that Mitchell can compete with other cities in beauty and offerings.
“It's just you haven't developed it. As that happens, this whole community is going to need this bigger sanitation system,” Garrison said.
The foundations of two buildings at the south wastewater treatment complex have been laid, and yet, the whole complex is still over a year out from final completion.
The $39.2 million south wastewater treatment complex includes a $6.74 million blower building, a $11.53 million dewatering facility, and an equalizing storage basin for $2.77 million. The bid for construction from John T. Jones Construction was $32 million. There are $17 million in grants for the complex, according to Public Works Director Joe Schroeder.
When residents flush a toilet or take a shower, wastewater passes through the
$15.3 million north wastewater treatment facility, where larger solids and grit are removed
. Afterward, wastewater makes its way two miles to the south wastewater treatment complex.
First, wastewater comes to two open-air in-ground basins to be agitated. Presently, the city uses giant egg beaters to agitate the wastewater, which are not energy efficient. The city is replacing the egg beater system and old compressors with forced air from four air blowers stationed inside a dedicated blower building.
It's cheaper to produce the air than it is to run egg beaters, according to Garrison. One new air blower is equivalent to the turbulence produced by three of the existing blowers on site, which are set to be decommissioned.
“Now, they've got two blowers inside this existing little building here, and they're just underpowered, that's the bottom line. So this will give them more volume and more velocity as well,” construction superintendent Andrew Smith said.
The four walls of the blower building have been erected, but no roof has been installed. There are four concrete platforms for air compressors to be placed, which will send 20.5 pounds per square inch or 800 standard cubic feet of forced air per minute through underground pipes into the open air basins like a kid blowing air through a stray into a cup of water.
“It activates the waste product and makes it to where it's biodegradable much quicker,” Garrison said.
The aeration process allows for greater oxygen coverage so that microbes, which require oxygen to live, can eat the organic waste. The south wastewater treatment complex uses a chemical free process.
From the open-air basins, wastewater will travel to a nearby splitter box before being sent to clarifier pits to further break down waste material.
“The clarifiers separate the liquid from the solid,” Garrison said. “It's organic material, and that's what we call sludge.”
Sludge waste material will be pushed via pipeline down to the dewatering facility once it becomes fully operational in fall 2026 while clarified water is sent to a lagoon pond to further break down.
“Quite a bit to do, and a little time to do it,” Smith said.
The dewatering facility’s foundation is poured and has a sloped floor for drainage, with a center vaulted containment area under the slab. Stem walls, which will hold the three-story structure, go underground about five feet.
“A lot of engineering goes into what looks like a very simple little building slab,” Garrison said.
Metal pipe was installed in sub-zero temperatures and crews dealt with groundwater seeping into work areas. It took about six months to complete the ground level work.
“These guys fought like animals to get it done,” Garrison said.
Prefabricated concrete walls arrived on long flatbeds via a semi-truck, to be installed on the stem walls. One wall panel, 12 feet wide by 32 feet tall, weighed 41,700 lbs.
Once sludge is dewatered, it will travel the short journey via dump truck to the landfill. Volume of processed waste at the facility will determine how often a truck is filled with dewatered sludge.
“We're trying to break up the solids into a sludge, and reuse the sludge and spread it over the landfill. We need to cover the garbage,” Mitchell Engineering Supervisor Terry Johnson said.
1/9: Giant egg beaters, set to be replaced with forced air, agitate wastewater at the south wastewater treatment complex pictured on Tuesday, April 8, 2025, south of Mitchell.
Adam Thury / Mitchell Republic
2/9: Two giant egg beaters, set to be replaced with forced air, agitate wastewater at the south wastewater treatment complex pictured on Tuesday, April 8, 2025, south of Mitchell.
Adam Thury / Mitchell Republic
3/9: Construction of the blower building, which will send forced air to two open-air basins to agitate wastewater, at the south wastewater treatment complex pictured on Tuesday, April 8, 2025, south of Mitchell.
Adam Thury / Mitchell Republic
4/9: Welder aids construction of the blower building, which will send forced air to two open-air basins to agitate wastewater, at the south wastewater treatment complex pictured on Tuesday, April 8, 2025, south of Mitchell.
Adam Thury / Mitchell Republic
5/9: General Superintendent Andrew Smith and Engineering Inspector Bryan Garrison look over plans for the construction of the wastewater treatment plant as pictured on Tuesday, April 8, 2025, south of Mitchell.
Adam Thury / Mitchell Republic
6/9: Construction of the basin, yet to have concrete poured, at the south wastewater treatment complex pictured on Tuesday, April 8, 2025, south of Mitchell.
Adam Thury / Mitchell Republic
7/9: Construction of the basin, yet to have concrete poured, at the south wastewater treatment complex pictured on Tuesday, April 8, 2025, south of Mitchell.
Adam Thury / Mitchell Republic
8/9: The foundation of the dewatering building, where water will be removed from solid waste, at south wastewater treatment complex as pictured on Tuesday, April 8, 2025, south of Mitchell.
Adam Thury / Mitchell Republic
9/9: Construction of the basin, yet to have concrete poured, at the south wastewater treatment complex pictured on Tuesday, April 8, 2025, south of Mitchell.
Adam Thury / Mitchell Republic
Thick wastewater awaiting processing at the dewatering facility will be sent to an equalization basin, which is a large holding tank that helps equalize the pressure and volume inside the dewatering facility.
“It can only process so much at any given time, so if the volume is too high, this is storage,” Garrison said.
The foundation of the above-ground basin will be poured in three sections, and already has a sump pump throat poured, according to Garrison. The walls will be poured in place and use a product called xypex, which is a self-healing concrete.
“It's another year of just setting equipment and process pipe and tuning everything in,” Garrison said.
There are five city lagoons, at various depths, covering a 240-acre area holding about 700 million gallons of water. The only thing that leaves the landfill and treatment facility is the clarified water that comes out on the far end of the lagoons a year after being flushed through city pipes.
Lagoon water is transferred from one lagoon to the next, with a focus on moving top water with the least amount of sediment. In the spring and the fall, the lagoons are emptied into the James River by permit from the South Dakota Department of Agriculture and Natural Resources.
“The water on the way out is much cleaner than Lake Mitchell,” Garrison said.
1/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
2/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
3/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
4/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
5/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
6/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
7/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
8/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
9/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
10/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
11/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
12/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
13/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
14/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
15/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
16/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
17/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
18/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
19/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
20/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
21/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
22/31: City of Mitchell engineering supervisor Terry Johnson and HDR engineering inspector Bryan Garrison survey the scene at the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
23/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
24/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
25/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
26/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
27/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
28/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
29/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
30/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
31/31: Scenes from the south wastewater treatment complex, where walls for the dewatering facility were laid in place by crane and the concrete foundation for the basin was poured, as pictured on Wednesday, April 16, south of Mitchell.
Adam Thury / Mitchell Republic
At the Jan. 21 city council meeting,
the council voted unanimously to raise water rates
, effective on April 1, from $16.75 per 750 gallons to $18.62 per 750 gallons. Additionally, an increase to $20.50 per 750 gallons goes into effect on Oct. 1.
In March, Mitchell Mayor Jordan Hanson attributed the recent rate hikes in residential water bills to the city’s increase in water infrastructure projects.
The city of Mitchell has utilized various State Revolving Fund loans for water projects, which require that the city prove that it has revenue to pay back the loan. This proof comes in the form of revenue from residential water bills.
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