Sanitary Sewer Department

Summer is the season for sewer cleaning. The city has 93 miles of sanitary sewer lines. Each year, the Public Works department cleans approximately 1/4 of the city's sanitary sewer lines. The sanitary sewer lines are cleaned using high performance sewer cleaning equipment. A cleaning nozzle is propelled from 1 manhole to the next using water under high pressure. The nozzle is then pulled back to the starting manhole. As the nozzle is pulled back, water scours the inside of the sanitary sewer pipe. Any debris in the pipe is pulled back with the water. The debris is removed from the manhole with a vacuum unit. If roots are found, they are cut with a root cutter. This process is repeated on every sewer line cleaned.
During the cleaning process, air occasionally vents into a home through the sanitary sewer service line and ventilation system. When this happens water in the toilet bowl can bubble or surge or, in rare cases, splash out of the bowl. The common causes of air venting into homes during sanitary sewer cleaning are: air movement from    normal cleaning operations, the use of higher pressure necessary when cleaning sanitary sewer lines that have a steep slope, sewer lines running close to the building, a plugged roof vent, and the size and complexity of the home's waste and ventilation system.So, to minimize water splashing out of your toilet bowl, make it a habit to keep the lid down.
Sewer Backups
If you experience a sewer backup and do not know where the blockage is, you should contact the city before contacting a drain cleaning company. You may be able to avoid an unnecessary charge if the problem is in the city’s sewer line rather than in your property’s service line. A Public Works employee will determine if the problem is in the city’s line or in your property’s service line. You can call us at 763-755-5100. 

The property owner is responsible for clearing any blockage in the service line between the home and the city sanitary sewer main. This includes debris and tree roots. The property owner is also responsible for cleaning and repairing any damage done to the property by the backup. The city is not automatically liable for blockages in the city’s sanitary sewer system. The city is only liable for those damages if the backup was caused by the city’s negligence. Most homeowner insurance policies exclude damage resulting from sewer backups. Many insurance providers do have insurance riders that can be purchased to insure loss due to sewer backups.

Causes for Sewer Backups
Sanitary sewer line blockages are typically caused by roots, grease, and improper disposal of items. Occasionally a blockage is the result of a broken service line as a result of being driven over during or after construction of the home. In some cases it has been a few years for the broken service line to be detected. Tree roots can enter the sanitary sewer system at joints and cracks in the sewer service lines and mains. Grease can solidify in the sewer lines and restrict other waste from flowing through. The lines can be blocked by items like disposable diapers, paper towels, dental floss, bathroom cleaning wipes, feminine hygiene products, washing machine lint, or other items improperly flushed down the drain or toilet. There are some products on the market stating they are flushable but in reality is a major cause of most of the blockages. All of the stated items should be thrown away in the trash. The sanitary sewer system is not a garbage can. If it's not toilet paper, don't flush it. The video below shows what happens to some of these items. Watch the Will It Flush Video for more information.

Contact Us

  1. Brian Kraabel
    Utilities Manager
    Ph: 763-767-5180
    Staff Directory
Lift Stations
The city also operates and maintains 9 lift stations at various locations throughout the city. As stated in the above paragraph, items that are introduced into the sanitary sewer system creating blockages can also get into the pumps and cause bigger problems. 
Lift Station

Pump Failure
When pumps fail, crews are sent out to clean and replace, if necessary. Items get into the pump impellers and get tangled. The pumps stop and in some cases cause the pump to overheat. These pumps are very expensive and take time to replace. The longer it takes to replace these pumps and clean out the system, the greater the chance of having a backup into a home or group of homes.

Watch the Will It Flush Video on YouTube for more information.
Pump Backup
Sewer Odors
Floor and sink drains usually have water filling the bottom of the drain trap which acts as a barrier between the air in the sewer line and the air in your home. When a drain trap becomes dry, sewer odors can enter into the residence. If you experience sewer odors in your home, run water down all your drains.
Sump Pumps
If you use a sump pump in your basement, it is illegal to drain the water into the basement sanitary sewer drain or laundry tub. Sump pumps must be discharged outside of the house to the yard or drain way that will prevent the water from draining directly to the street. Call the Public Works department if you need more information.

How to Prevent Backups

Property owners can do many things to prevent their service from backing up. Remember, the very same things can help prevent backups in the city main as well.
  • Grease: Cooking oil should be poured into a heat-resistant container and disposed of in the garbage after it cools, not down the drain. Some people assume that washing grease down the drain with hot water is satisfactory. This grease goes down the drain, cools off, and solidifies either in the drain, the property owner's service, or in the sewer main. When this happens, the line eventually clogs.
  • Paper Products: Paper towels, disposable diapers, dental floss, flushable wipes as advertised and feminine products cause many problems in the property owner's service as well as in the city main. These products do not deteriorate quickly. They become lodged in portions of the service line, main line and pumps, causing sewer backups. These products should be disposed of in the garbage.
  • Illegal Plumbing Connections: Do not connect French drains, sump pumps, roof gutter drains, or foundation drains to your sanitary sewer service. It is illegal and will cause debris and silt to clog your service line. Consult a plumber to correct any illegal connections.
Sewer Use Ordinance
The City’s Sewer Use Ordinance prohibits certain discharges into their sanitary sewer lines.
Link for Sewer Ordinance 32 Sec

Sewer Maintenance Inspection Equipment
The Public Works department may use the following types of equipment when performing inspection and maintenance of its sanitary sewer system:
  • Sewer Jetter / Vactor - The jetter uses a high pressure water system to clean the sewer main of debris, such as sand, grease, and other materials that settle in the sewer main. Using a high pressure water system, the jetter propels a hose, with a specially designed nozzle, into the sewer main. The hose is then pulled back slowly while the high pressure water system flushes the materials to a downstream manhole for removal by the vactor. The vactor uses a positive displacement to create a vacuum that can lift debris from manholes.
  • TV Inspection - Closed circuit television video (CCTV) inspection equipment and pipeline inspection/asset management software is used to inspect sanitary and storm sewers. The system uses a self-propelled transporter to carry the camera down the sewer main. While the camera is in operation, visual data is recorded for maintenance assessment needs.

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