The flushing factor
Sanitary district examining ways to improve stream water quality
Poor water quality plagues two Springfield streams, and part of the problem is the Springfield Metro Sanitary District, according to a recent study measuring fecal coliform bacteria, present in both human and animal waste, in Spring and Sugar creeks. The district occasionally sends untreated wastewater into the two streams at eight different points.
As a contributor to the two creeks’ fecal coliform content, the district is required to develop a long-term control plan that will necessarily include expensive alternatives for dealing with the untreated waste it now empties into the streams. But a recent study shows that other sources of fecal coliform bacteria contribute more often to the problem than does raw sewage.
The still-developing long-term control plan is meant to reduce the number and volume of the district’s “combined sewer overflows.” Combined sewer overflows occur during heavy rains and are a mixture of sanitary water, which is flushed or drained from homes and businesses, and storm water conveyed through street grates in amounts too great for the sanitary district to treat on the spot.
During heavy rains, the district captures and treats the “first flush,” which is the first rush of sewage to move through pipes during a storm. The first flush has the greatest concentration of sanitary water and, therefore, flushed fecal coliform bacteria. After the first flush and once the district reaches its treatment capacity, much of the storm-induced flow goes straight into Spring Creek, which has six overflow points along the meandering waterway that nears Veterans Parkway by Jefferson Street and again by the state fairgrounds, or into Sugar Creek, which has two overflow points, one near Harvard Park and one southeast of where I-55 meets I-72. Combined sewer overflows discharged into Spring Creek and Sugar Creek flow into the Sangamon River and eventually into the Illinois River.
The recent study, performed by Springfield engineering firm Crawford, Murphy and Tilly, shows that from May through October – the recreational season – Spring Creek’s fecal coliform levels exceeded standards between 60 and 64 percent of the time. Sugar Creek exceeds those standards between 25 and 44 percent of the time. SMSD was part of the problem during no more than 5.1 percent of the recreational season.
SMSD director Gregg Humphrey says much of the fecal coliform bacteria in Spring and Sugar creeks comes from natural sources. “The problem is with agriculture, ducks and geese – birds and everything that’s out there,” Humphrey says. “If you could kill all of the animals upstream, you’d be able to hit water quality.”
Regardless of the degree to which Springfield-area sewage contributes to Spring and Sugar creeks’ poor water quality, SMSD is required by law to examine ways to reduce the number and volume of combined sewer overflows it releases into the waterways. “What we add to it is minimal, but since we’re a contributor that’s where the regulation comes in for the sanitary district. We can’t cause or contribute, and we contribute,” Humphrey says.
John Wells, environmental protection engineer with Illinois EPA, says even the relatively low contributions of fecal coliform bacteria from the sanitary district are significant because human waste can contain parasites or pathogens that can cause serious illness.
“The combined sewer overflows are untreated sanitary sewage and storm water,” he says. “Attempting to reduce the number and volume of these discharges and to better treat them will provide benefits to the stream and the environment that go beyond just reducing fecal coliform and pathogens, as important as that is.”
Combined sewer overflows can also contain detergents, oils and other environmentally unfriendly substances.
Now that the water quality study is complete, SMSD must further examine ways to reduce the combined sewer overflows it sends to Spring and Sugar creeks. Some of those alternatives include separating the city’s combined sewers, creating a deep tunnel storage system and building a new treatment facility that would only be used during wet weather.
Each alternative comes with its own set of pros and cons, but Wells says any solution will be expensive. “They will be spending millions of dollars, no doubt.” But he adds that IEPA will work with the sanitary district to find a balance between acceptable cost and significant benefit.
Whether the eventual improvements will require increased sewage fees is still an unknown, Humphrey says. The district plans to submit its long-term control plan by the end of this year, at which point federal and state regulatory agencies will examine it and possibly suggest changes. “It’s not an overnight process,” Humphrey says.
SMSD will hold an informational public meeting, resembling an open house, regarding the study results and the district’s developing long-term control plan, from 4:30 to 7:30 p.m. on Aug. 3 at the Crowne Plaza Hotel on Dirksen Parkway.
Contact Rachel Wells at firstname.lastname@example.org.