Jamie Munks
The State Journal-Register
The swiftly pooling water that makes certain streets impassable and floods basements in some of Springfield’s older neighborhoods has become a theme during heavy rains, like the torrent that struck the city just over a week ago. And while work on the city’s sewer infrastructure and the Springfield Metro Sanitary District’s facilities is both underway and planned for the future, it’s unlikely even those sweeping efforts will eliminate all of the issues.
“It was a 50-year event. It was a severe weather event. We were anticipating showers, but not that much,” Springfield Public Works Director Mark Mahoney said. “And it varied across town. Some areas got 5 inches, while others got 2.5 inches.”
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Newly flooded areas, too
Ward 7 Ald. Joe McMenamin said he took a number of calls from residents in the city’s older neighborhoods that frequently experience flooding during heavy rains. In this instance, he also got a call from a resident who lives west of Chatham Road, which he found surprising, he said.
Springfield’s sewer system is made up of about 355 miles of separate sanitary sewers and about 140 miles of combined sewers. The city’s older neighborhoods with combined sewers are where many of the problems occur during the heaviest rains because they’re carrying a much larger volume due to the stormwater flow.
McMenamin said he heard from residents about basement and sewer backups as well as plugged street drains. Some of those came from areas of the city that have been identified as problems, including an area from State Street to Glenwood Avenue between Laurel and Ash streets, he said.
The city council last month approved a $45,000 engineering study to examine the sewer system in that area. Essentially, all of the calls from residents that Springfield’s sewer division takes during heavy rain are from people who live in older homes — some have groundwater infiltrating their basements, others have sewers backing up, and some have both, city sewer engineer John Higginbotham said.
Homes constructed after 1975 are required to have “overhead” sewer systems installed, and the city has an overhead sewer system program in place as an incentive to bring older homes up to the more current standards.
Higginbotham said a lot of people ask about the city installing new, larger pipes and separating the sewer system in the areas where it’s combined, but both of those efforts are very involved and costly and in some cases won’t eliminate the problems at properties with gravity service between the residence and the city sewer. “Homes with ‘gravity’ floor drains, even with a brand-new system, would be open to basement backups,” Higginbotham said.
The city’s program pays for 15 percent of the plumbing modification up to $600. McMenamin said he has suggested in the past that the city increase its contribution.
Mostly maintenance
Springfield is in the midst of a long-range, multimillion-dollar infrastructure overhaul plan. The city council last year approved annual 5 percent sewer rate increases for 10 years that will help maintain the aging infrastructure. While a lot of people inquire about sewer system separation, plans related to that are “very, very preliminary,” and most don’t call for large-scale separation projects, Higginbotham said.
All of the public works capital improvement plans for sewers are tied to the decade-long sewer rate hikes, but, while some upgrade projects are included, the overwhelming majority of the projects are for maintenance, Higginbotham said.
The city’s sewer system is overseen by two different governing bodies: The city owns and maintains the collection system, while the Springfield Metro Sanitary District operates the treatment facilities that receive all of the flow from the city’s system. The district is a separate entity that levies its own user fees independent of city sewer rates. The district is in the process of upgrading its two major treatment facilities — Spring Creek and Sugar Creek — to increase capacity.
Upgrades are ongoing at the two plants following direction from the Illinois Environmental Protection Agency in 2005, which deemed they were processing sewage containing more organic material than they were designed for.
Capacity at both of the treatment plants operated by the sanitary district were maxed out as a result of the Aug. 28 storm. Including both the treatment and stormwater capacity at the Spring Creek and Sugar Creek treatment facilities, “maxing out” means roughly 250 million gallons and 100 million gallons per day, respectively.
“It could have been worse,” said Gregg Humphrey, director of the sanitary district. “(We’re now) able to take in 60 percent more through treatment.” The long-term control plan aims to reduce the number of overflow occurrences, but it won’t eliminate them.
The Spring Creek project increased the treatment capacity by 30 million gallons per day. The planned Sugar Creek upgrade project would take its treatment capacity up to 37.5 million gallons per day, Humphrey said.
Joe McMenamin for Ward 7 