With $4 million in hand, the City of Springfield is set to start on an $8 million-plus sewer project in north-central Springfield this summer, helping to expand and improve the city’s aging sewer infrastructure.
The work should also help protect two creeks.
The Pea Ridge Creek Sanitary Sewer improvements will replace sewer mains along Doling Branch and Pea Ridge Creek. Originally estimated at $6.8 million, the combined cost of the two projects has since ballooned to somewhere between $8-9 million due to inflation, according to Tim Schoenhoff, a professional engineer for the Springfield Clean Water Services Administration.
The projects, which will cause several road closures and a bore under Interstate 44, are on track to get started in June. The are part of Springfield’s Supplemental Overflow Control Plan, which was revised in 2021.
Aging pipes, heavy rain contribute to sewer overflows
Most of the Springfield sewer system is estimated to exceed its expected 50-year lifespan over the next decade, and much of it is already more than 100 years old. Schoenhoff estimates the Pea Ridge and Doling Branch sewer lines to be between 80 and 100 years old. Sewer main pipes have deteriorated as the system has aged. This deterioration causes sewer overflows in manholes, during heavy rainfall events or when other objects, such as tree roots, clog the pipes.
After doing an extensive analysis across the sewer system, public works staffers identified “pinch points,” where sewer overflow was at its worst.
“That’s where both these projects came from, ‘Hey, we have a pretty big problem here,’” Schoenhoff said.
Erinn Kemper, the director of environmental services with the city said that this project represents a “substantial improvement to the sewer system,” and that, in addition to eliminating overflows, will improve water quality.
“The sewers are undersized during rain events,” Schoenhoff said. “That’s our biggest issue, what we’re trying to fix here. Under really any rain event, or mostly over a half inch, sewage is coming out of these manholes and it’s getting in these folks’ backyards.”
Pea Ridge improvements come with high price tag, high impact
The Pea Ridge project extends from just east of National Avenue, near Snider Street, to where Pea Ridge Creek and Doling Branch meet just north of the former Central Bible College. The Doling project extends south from where it intersects with Pea Ridge Creek, through Doling Park, to Talmage Street.
The Pea Ridge project will replace roughly 5,500 feet of 12-inch sewer main with 24-inch pipe, while the Doling project will replace 6,873 feet of sewer main with new piping 12 inches in diameter larger than the existing 18-inch system. The Doling main will expand even larger under I-44.
Brief road closures are expected to occur on Norton Road and at the intersection of National Avenue and Vernon Street, but the boring under I-44 will not impact traffic. In addition, closures of portions of the Greenway Trail and Doling Park will take place during construction.
Nearby residents will be notified of when they will experience sewer service interruptions, lasting at most a few hours.
While public works staffers hope to eventually have both projects being constructed concurrently, work on Doling Park will begin first, and make its way down to the park by late 2023 or early 2024.
On April 17, the Springfield City Council approved a bid for $5,626,850 from Rosetta Construction, who will head the Doling Park project. Because contractors are still awaiting bidding for the Pea Ridge project, the City Council voted to move only $4 million from the Clean Water Fund, which is primarily comprised of wastewater fees, for the project at the May 8 meeting. The Pea Ridge project is estimated to cost about $3.5 million, according to Schoenhoff.
While the biggest priority is eliminating sewer overflows, Schoenhoff said they are also expanding the sewer pipes for the potential of future population growth.
“It also increases the capacity for future development in the area if things redevelop or if stuff happens upstream of these properties,” he said.
While the sewer mains themselves will run along less than 50 residents’ properties, the projects will have a much wider impact on the northern watershed of the city. While the city has worked on other sizable sewer projects, the Pea Ridge Creek improvements are significant in scope.
The city continues to work towards fulfilling the Overflow Control Plan, which has been amended numerous times since the Missouri Department of Natural Resources and Springfield entered a consent judgment in 1995 to get the city’s sewer system to comply with the Clean Water Act. An estimated $300 million still needs to be invested in the city’s sewer system to fulfill the plan.
Like with these projects, Schoenhoff expects inflation to continue playing a role in the city’s ability to fund sewer improvements.