PROGRAM INFORMATION

 

About Inflow and Infiltration (I/I)

The sanitary sewer system in your community was designed to convey domestic and commercial wastewater to the wastewater treatment plant, where pollutants and wastes are removed before the water is discharged into the environment. Rainwater and groundwater, called 'clear water', typically does not require treatment. Clear water should be directed to the ground surface or storm sewer,  flowing into receiving streams and lakes, and. not be directed into the sanitary sewer.

Excess clear water in the sanitary sewer collection system leads to unnecessarily high flows within the sewer. These high flows can cause basement sewage backups, bypassing of untreated wastewater into receiving streams, or increased taxpayer costs for constructing and maintaining an oversized collection system.

The City regularly engages in maintenance to correct cracks and other defects in pipes and manholes to reduce clear water infiltration into the sanitary sewer collection system. However, a significant source of clear water is often found on private property collected by roof drains, sump pumps, seepage collection systems (known as "beaver drains") and footing drains.

Even a few sump pumps or footing drains improperly connected to the sanitary sewer can significantly impact the community's collection system. A typical sanitary sewer pipe in a residential neighborhood has an 8" diameter pipe with a typical capacity of 350 gallons per minute (gpm). This capacity is sufficient if only domestic wastewater enters the pipe. However, adding a few sump pumps  which can discharge between 20 to 100 gpm each, could quickly overload the pipe, potentially leading to backups in that neighborhood.

The City of Wanamingo will conduct  sump pump inspections to verify that sump pumps, roof drains, and other clear water sources are not connected to the sanitary sewer system.

The program’s goal is to remove clear water from the sanitary sewer collection system, reducing the potential for sanitary sewer backups, improving public health and extending the service life of the sanitary sewer collection system and treatment plant, leading to lower taxpayer costs.

Additional I/I Handouts and Information

About the Inspections

Timeframe: The program area will be inspected in the fall/winter of 2024.  

Scheduled Appointments: To ensure resident safety, all inspections will be scheduled. No door-to-door inspections will be conducted. Inspections will typically be completed between the hours of 8:00 am  and 4:00 pm.

Web or Telephone: Both a telephone number and a web based option are available for ease of appointment scheduling.  The secure web-based scheduling system allows residents to schedule an appointment. Residents who prefer not to use the Internet can call our toll free telephone number to schedule an appointment.

Identification of Inspectors: WHKS inspectors will be wearing an identification badge with the WHKS and City logos, and their clothing and vehicles will have WHKS branding. If you have any questions about the identity of the inspectors, please feel free to contact us.

Prepare for the Inspection: Before the inspection make sure there is clear and easy access to your sump pump (if applicable) and the water meter (for material inventory).  This will allow the inspection to occur in a timely matter.  

The Inspection:   An adult occupant must be present during the inspection.  The sump inspection will consist of observing the following items:

  1. Exterior Grading: Does the exterior grading slope towards the building?
  2. Roof Drains: Are there roof drain downspouts that lead to the ground?
  3. Basement: Is there a basement?
  4. Seepage Collection System (Beaver System): Is there a seepage collection system? If present, does it discharge into a sump pit (proper) or the floor drain (improper)?
  5. Sump Pit/Sump Pump: Is there a sump pump? If present, does it discharge outside the basement through a rigid pipe (proper), discharge to the floor drain (improper), or discharge to either location through a flexible hose (improper)?
  6. Water Service Line Material: Record the material of the water service entering the building. 
 
If a sump pump or roof drain discharge location cannot be determined by visual inspection, it shall be noted and the appropriate City personnel will follow up with the occupant at a later time to determine the discharge location. 
 

If an improper connection is found, the inspector will issue a Violation Notice to the occupant and explain the necessary steps and timeframe for correction. A reinspection must then be scheduled and conducted to verify that the correction has been made.

Inspection Time:  A typical inspection  can be completed in under 15 minutes. 

Improper Connection: Flexible Hose Proper Connection: Rigid Discharge Pipe To Exterior.


Typical Water Meter