Sewer Lateral Backflow Prevention

Homeowners that have experienced or are concerned about sewage backing up in their basement may want to consider installing a Backflow Preventer on their sewer lateral.  These devices would be most effective in combined sewer areas or in separate sanitary sewer areas where a basement has sewer service.  Also, homeowners that have experienced sewer backups in the past are encouraged to consider this as a potential solution to preventing future sewer backups or flooded basements.

How can my basement flood with sewage?

Combined sewers are used to collect both storm water and waste water.  During dry conditions, the sewers are able to handle the waste water flow.  During wet weather, the sewer may become surcharged due to the volume of storm water which will cause the sewage to back up in your lateral.  If there is enough of a surcharge in the sewer, it is possible for the sewage to enter your basement or crawl space.  Removal of gutter downspouts and sump pumps from the sanitary or combined sewers will help reduce basement flooding.

How can a backflow preventer stop sewage from entering my basement?

A backflow preventer is equipped with a valve that will close when the sewer is surcharged.  During this time, your residence will be cut off from the sewer.  When the sewer is able to accept flow from your lateral, the valve will open and your lateral will drain into the sewer.

Is a backflow preventer required by the City?

No, the property owner must decide if a backflow preventer is appropriate for their situation to prevent a wet basement.

What about clean water connections to the sewer with a backflow preventer?

Clean water connections to a separated sanitary sewer are strictly prohibited and must be removed.  The City has a grant program to provide financial assistance with removing sources of clean water connections from either a separated sanitary or combined sewer.  Please contact the Utility Department for more information.  Also, click here to view the Clean Water Removal page.

If you are in the combined sewer area and have clean water connections to your sewer lateral such as a perimeter foundation tile, down spouts from gutters, or a sump pump; you are strongly encouraged to remove these clean water connections from your sewer lateral prior to installing a backflow preventer.  If these are not removed prior to installing a backflow preventer, you may cause your basement to flood due to the volume of clean water being generated from your own residence.  Should the backflow preventer close due to the sewer surcharge, your sewer lateral will fill up with clean water and reduce the storage capacity for your waste water and possibly cause a wet basement.

What about maintenance?

All mechanical devices require routine maintenance.  A backflow prevention device should be inspected on a regular basis to ensure proper working condition.  Local plumbers will be able to assist you if you need help.    The homeowner is responsible for maintaining these devices installed on their sewer lateral.

Is there any financial assistance availble for a backflow preventer?

The Utility Department does not offer financial assistance at this time.  You may qualify for assistance through the City Housing Program, call 419-354-6203 to see if you qualify.

What if I have more questions?

Contact the Water & Sewer Division at 419-354-6277.