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Wastewater Treatment Plant

Kirksville’s wastewater treatment processes essentially accelerate nature’s clean-up methods, through the use of bacteria and enzymes, which "eat" the harmful pollutants in the water. Water velocity also affects treatment because the speed of the flow of the water will determine how much settling occurs. For example, if you stir sugar into tea, the action of stirring causes the sugar to be suspended in the tea. If you leave the tea for a while, some of the sugar will settle out. It follows that the flow of water must be monitored in sewer lines. If the water is moving too slowly the solids settle out and the lines become blocked.

The objectives of wastewater treatment include:
  • Prevention of nuisances
  • Avoiding water supply contamination
  • Maintaining clean waters for the propagation and survival of fish and other wildlife
  • Conservation of water for all uses

Lift Stations:

There are 17 lift stations in Kirksville. Lift stations are low points where gravity takes sewer water. The station then lifts the water by pumping it up to a point where gravity can carry it to the wastewater plant. "Good" bacteria and enzymes are added at the lift stations to reduce odors caused by hydrogen sulfide gas which can build up in sewers. This gas will corrode the collection system used to transport water if it is not controlled. Each lift station has at least two pumps and some stations have a basin that can hold excess wastewater should there be an emergency.

The Treatment Process:

Once the collection system takes wastewater from the lift stations to the wastewater plant, pumps in the influent pump station lift the sewage to levels where gravity can take it through the plant. From there it goes to a grit chamber which settles out some of the heavier materials in the wastewater. Further material is removed in the headworks building by a mechanical bar screen which removes things like rags, sticks and other debris.

From the headworks building the flow makes its way through the activated sludge process. It goes into the anoxic zones first which has mixers to keep the solids suspended so they can move on through the aeration basins. While in the aeration basins air is added to create oxygen by using blowers to help with the treatment process and supply oxygen to the microorganisms. 

Once the flow leaves the aeration basins it goes in the clarifiers which allows for any heavy pollutants to settle out which goes to the Ras/Was pit and the floatable materials such as oil and grease to be skimmed off into a scum pit. From these two pits, it will be pumped to the above-ground tanks called digesters. While in the digesters floating aerators mix and create oxygen to digest and decompose any organic materials. The sludge created by the digesters is ultimately hauled to farmers' fields as fertilizer. 

Biological Treatment:

Biological treatment occurs throughout the activated sludge process. Microorganisms enter the aeration basins at the anoxic zone which has no oxygen. They are slow and sluggish at this point. Once leaving the anoxic zone they are introduced into the aeration basin where we add air for oxygen. This creates a better quality of life for them and they will become very active and feed well on the waste coming in and reproduce very well. These two qualities are very important because these microorganisms are the biggest factor in the treatment process. 

Exiting the Treatment Plant:

This wastewater treatment process requires extensive monitoring. The plant can treat 5 million gallons of water per day but currently averages 2 million per day. It treated more than 1.06 billion gallons of water last year. Treated water discharged to Bear Creek must be tested for nutrient levels weekly. Other tests must be performed daily to make sure everything is working properly. The industries in Kirksville are also monitored to make sure they don’t put any pollution into the wastewater system.

Maintenance of Operations:

Extensive maintenance also comes with extensive monitoring. The equipment must continually be checked for breakdowns. If a breakdown occurs the backup systems must be put into operation immediately. Personnel checks lift stations each day to make sure the 37 pumps and motors are working properly and check sewer pipes for corrosion. Hauling the sludge to farmers’ fields is also time-consuming and costly.

Plant Operators’ Qualifications:

All operators are licensed by the state of Missouri to handle wastewater. Four levels of operator certification are available through the Department of Natural Resources. Several years of experience are required to obtain the highest certification. The operators are required to have 30 hours of ongoing education and training every three years to maintain their license. A lot of time and effort are put into this facility to ensure that the wastewater is properly treated.

How this Division Benefits You:

The City’s wastewater treatment accelerates the natural process of cleansing wastewater, it minimizes harmful by-products of pollutants to our environment. Without proper treatment procedures, the health and well-being of the community and downstream water users suffer.

Contact Information


23002 Atlas Lane
Kirksville, MO 63501

Phone: (660) 665-2861
Fax: (660) 785-6937

Office Hours:
Monday - Friday, 7:00 am - 4:00 pm

Tim Reed Superintendent