The City of Owatonna provides wastewater treatment that results in high-quality, return flows to the river. The wastewater collection within the city is accomplished through approximately 200 miles of collection lines with some lines dating back to the early 1900s. The collection system functions primarily by gravity flow, however, lift stations are utilized at some points along the system.

Wastewater Treatment Facility


The City of Owatonna’s treatment plant was built in 1987. The average daily flow through the wastewater system is approximately 3.5 to 4.0 MGD with the maximum peak daily flow of 10 MGD.

Sanitary Sewer Ownership

As a property owner, you own your sewer service from the building to the City sewer main. The City owns and maintains the sewer main which is generally located in the middle of the street. The City cleans and inspects the main lines according to the Owatonna Sanitary Sewer Maintenance Policy. Maintenance crew's use a high pressure jet of water to clean the walls of the sewer main and push material and debris downstream where is can be removed at a manhole.

Slow Drains

When you experience slow drains or sewer back-up, it is important to call the Wastewater Treatment Facility in addition to calling your plumber. We will inspect the City sewer main and determine if the blockage is in the mainline or the private service line. If the problem is in the City main, we can alleviate the problem at no cost to you. If the problem is in the private sewer line, staff will advise you of any action you should take.

Causes of sanitary sewer backups are:

  • Invasive tree roots
  • Putting items down your drain that should be put into your garbage
  • Sewer Pipe problems (private and / or City Main)

Things to Remember

  • Call Gopher One at 800-252-1166 to locate utilities prior to digging.
  • Call the Wastewater Treatment Facility at 507-444-2452 whenever your private contractor cleans your service line. This helps prevent roots and debris from getting pushed out of your private service line to the city mainline and cause a backup.
  • Permits are required when digging up service lines.
  • Sewer odors occur when basement floor drains have dried up and allow sewer gas to enter the home. These drains need to be checked periodically and refilled with water. Pour water into the drain to keep it filled. If the odor persists, call the Wastewater Treatment Facility at 507-444-2452.