What is a Combined Sewer Overflow?

Underground sewers carry the water and sewage sent down the drain to the wastewater treatment plant.  Combined sewers also collect rainwater runoff in the same pipe.  When the amount of rain causes the water to exceed the capacity of the pipe, some of the untreated stormwater and wastewater flows into the river and it is called a combined sewer overflow.  This occurs at sites that are permitted combined sewer outfalls.

Where are Combined Sewer Outfalls Located in South Bend?

Every combined sewer overflow (CSO) outfall location has its own sign located along the river that reads, "Wet Weather Notice.  This is a combined sewer overflow outfall.  This water can become polluted during or after rain events or snow melt.  It is not advisable to swim or fish here during these conditions.  In the event of discharge from this outfall during dry weather or for more detailed information, please call the Department of Environmental Services 574-277-8515."  The permitted CSO outfall number is also listed on the sign.  The City of South Bend maintains these signs as part of the CSO Operational Plan and will replace signs as needed to ensure compliance.

What Public Entities are Impacted by Combined Sewer Overflows?

The identified public entities that could be impacted by combined sewer overflows in South Bend are the St. Joseph Count Health Department (contact via mespich@sjcindiana.com and envirohd@sjcindiana.com), the St. Joseph County Parks Department (contact via sslauson@sjcparks.org), the City of South Bend Venues Parks and Arts (contact via jmartine@southbendin.gov), and the Berrien County Health Department (contact via bchd@bchdmi.org).  Each of these public entities was contacted for comments during the development of this plan and no comments or recommendations were given.

How is the Public Initially Notified of a Combined Sewer Overflow?

When a combined sewer overflow event is known or likely, an initial overflow event alert is sent using a distribution emailing system within four hours of becoming aware of the event.  The notification will indicate that an overflow is likely to be discharging to the St. Joseph River on that day and that public access areas that could potentially be impacted are the East Race Waterway and any boat launch between the Logan Street Bridge and the Toll Road. The public entities listed above and anyone from the public who requests it will receive these notifications.  Call 574-277-8515 if you would like to be added to the list to receive these email notifications.  These notifications could be delayed beyond four hours due to computer systems malfunctions.  Every effort will be made to keep this from occurring.

How are CSO Discharge Volumes and Durations Measured or Estimated?

In wet weather, the volume discharged and the duration of the discharge is calculated using metered data for the five largest CSOs in South Bend.  For the remaining CSOs, a matrix using precipitation is used to estimate the start time, volume, and duration of the discharge.  The matrix was created from a South Bend design storm model.  This model is assessed every five years to determine whether recalibration is needed and recalibrate if necessary.  Precipitation from snow will estimate overflows just as rain would.  In the event of an overflow at an estimated site due to snow melt, a notice will be sent but the volume of overflow will have been previously estimated when the snow fell.  For dry weather overflows, sensor data is used to estimate the volume and duration of an overflow.  

What Additional Information is Supplied by Public Notice After an Overflow?

Within seven days of any combined sewer overflow event, a supplemental notice will be sent to the same email distribution list to give more information about the overflow event.  This notice will include the estimated volume discharged from CSOs during the event and the date and time the discharge ended.  If the initial notice included this information, a supplemental notice is not required.

In addition, the City will make available by May 1 of each year an annual notice describing CSOs that occurred in the preceding calendar year.  The annual notice will be available on the City's website.  The annual notice will contain the location and receiving water for each CSO discharge point, the date, location, approximate duration, measured or estimated volume and cause of each wet weather and any dry weather discharge from the previous year, the precipitation data in total inches to the nearest tenth of an inch that resulted in a wet weather CSO discharge, and a description of the public access areas potentially impacted by the CSO discharges.  It will also contain the permittee's contact information, a summary of available monitoring data for CSO discharges, a concise summary of the implementation of the nine minimum controls and the status of the implementation of the Long Term Control Plan, including what key milestones remain and a description of the average annual number of CSO discharges anticipated after the Long Term Control Plan is fully implemented.

311 Process Notes

Please send calls about CSOs and requests for CSO notifications to 8515.