SOUTH BEND, IN — American Structurepoint, as a key member of the consultant team led by Stantec, has contributed to the City of South Bend, Indiana reaching an agreement with the United States Department of Justice (DOJ), United States Environmental Protection Agency (EPA), and the Indiana Department of Environmental Management (IDEM) on its updated Combined Sewer Overflow (CSO) Long Term Control Plan (LTCP). The new plan will implement advanced modeling techniques and innovative combined sewer overflow management solutions to help the city save more than $400 million in its mission to reduce overflows impacting St. Joseph River water quality.

The update modifies the city’s 2012 consent decree with the EPA that established a plan to reduce CSOs by 2031. Phase I improvements successfully decreased overflows, creating an opportunity to re-evaluate Phase II strategy to optimize efficiency and cost. Phase II was projected to cost more than $713 million. The revised plan includes $276 million in capital improvements, saving the city $437 million in projected costs. It also has a new deadline of 2038.

In 2015, South Bend hired the Stantec-American Structurepoint team to reassess its long-term control plan after completing Phase 1 of the plan. Other subconsultants to Stantec included LimnoTech and Xylem. The reassessment sought to find a more cost-effective approach for reducing overflows from the city’s 34 outfalls located along a 7-mile- long stretch of the 5t. Joseph River. Over several years, the team worked with the city to develop a tailored solution optimizing existing infrastructure while implementing advanced regional storage controls.

American Structurepoint performed conceptual design analysis and developed cost estimates for potential alternatives for treatment capacity, in-line storage, offline storage and treatment, real-time controls, and green infrastructure. Costs were used by the city to assess improvement and affordability for the rate payers. The Stantec – American Structurepoint consultant team developed a revised LTCP, known as the Smarter Alternative for a Greener Environment, integrating gray and green infrastructure with advanced technology to mitigate overflows. Plan elements include:

• Expanding the city’s wastewater treatment plant capacity to 100 million gallons, including a 2-million-gallon equalization basin.
• Building three new retention treatment basins with a combined volume of over 10 million gallons. The retention basins will store overflows and send them to the treatment facility once capacity becomes available.
• Nearly 4 miles of large diameter conveyance improvements.
• Targeted green infrastructure including sewer separation, green alley improvements, and rain barrel
• programs.

With all improvements in place, South Bend will capture and treat 99.6% of combined sewage generated during wet weather events, up from the original plan’s 89%. By capturing and treating the extra CSO volumes, the new plan is expected to reduce the amount of E. coli discharged to the St. Joseph River by an additional 12%.