For the second week in a row, considerable rainfall in the City of South Haven has resulted in sanitary sewer overflows into the Black River. City Wastewater Treatment Plant Superintendent Dave Mulac says the overflow was registered again this morning around 10:45am on Dunkley Avenue roughly 300 feet north of Dyckman Avenue.
At that hour this morning, approximately 100 gallons per minute of diluted wastewater was continuing to overflow into the storm drain and the Black River. That’s the same general site where the situation was compromised during last week’s torrential downpours in the city.
Mulac says the overflow was caused by inflow and infiltration into the wastewater collection system upstream from the Main Lift Station. Older sanitary sewers throughout portions of the collection system are susceptible to inflow of storm water during heavy rainfall and/or snow melt periods.
As the additional water moves downstream in the collection system, it must be pumped at various locations. At the time of the overflow the pumps at the Main Lift Station were unable to keep up with the large quantities of storm water flowing through the wastewater collection system. Excess flow which cannot be handled by the pumps overflows into the Black River through a storm drain located in Dunkley Street.
Mulac says city staff will continue to monitor the situation and file reports on the discharge with the Michigan Department of Environmental Quality and the Van Buren County Health Department.
Last week’s 8.5-inch rainfall in Van Buren County sent anywhere from 10-to-13,000 gallons into the Black River and also caused a breach in the Briggs Mill Dam in Paw Paw.
The City is currently constructing new interceptor sewers, a new main pump station, and an equalization basin to address the overflows that occasionally occur at this location. Those improvements are anticipated to cost in excess of $11,000,000 and will be significantly completed by the end of 2017.
South Haven City Engineer Larry Halberstadt says they won’t know the total overflow discharge volume until the rain ceases and the overflow stops. Stay tuned.
