At Marion Utilities, we’ve been working to protect and improve our local environment for decades. To that end, our efforts have been largely focused on reducing the negative impact of combined sewer overflows on the Mississinewa River. During wet weather, stormwater is captured and carried through common sewers along with wastewater from homes and businesses. When the volume of flow exceeds the sewer’s capacity, the excess flow discharges into the river creating a combined sewer overflow event. Reducing the frequency and volumes of those events are our main objective. Since the inception of the Stormwater Utility, back in 1995, tens of millions of dollars have been spent toward this effort. Nearly $14 million has been invested over the past ten years alone.
The first study commissioned for the purpose of understanding the impact of combined sewer overflows on our river was completed back in 1974. At that time, it was determined that nearly 1.2 billion gallons of flow was being discharged into the river during wet weather events over the course of a year. After much work and significant financial investment, a follow-up study was performed in 2009 to determine the level of progress. The results revealed that the volume of wet weather discharge had dramatically decreased to 182 million gallons per year. After further investment, and follow-up investigation in 2020, we determined that the yearly discharge volume had decreased again by nearly 70% to 55.5 million gallons. That means that we have reduced the overall negative impact of combined sewer overflows in our community by more than 95%.
As impressive as that is, we still have a lot of work to do to meet our ultimate goals.
Since early last year, we’ve been working with our engineering team to develop projects that will take us through the next phase of our plan. Bids have been received and financing is in place to begin construction sometime in late June or early July on projects totaling more than $12 million. Funding comes in the form of $11 million in revenue bonds and the remainder from cash on hand.
The projects include a large pumping and storage facility that will divert and store flow from wet weather events, preventing that flow from being discharged into the river prior to treatment. The idea is that when the heavy flows subside, the stored wastewater can be redirected back into the system for treatment through the wastewater treatment facility. In addition, an expansion to our existing disinfection process will be completed so that higher volume wet weather flows can be chlorinated and de-chlorinated more effectively and efficiently as they are processed through the treatment facility prior to final discharge into the river.
The goal is to complete all of the necessary projects associated with our Long-Term Control Plan by 2025. Future projects will include additional diversion and storage facilities located throughout the city in areas such as Home Ave. and Lincoln Blvd., Nebraska and Spencer Streets, and possibly 8th and Whites Street. With all of the projects complete, we expect the yearly combined sewer discharge volume to be less than 250,000 gallons. That is an overall reduction in negative impact to our environment of 98%.