September 20, 2010
Urbanization affecting water quality in Metro East
CARBONDALE, Ill. -- Fecal bacteria in the streams of Illinois’ rapidly developing Metro East exceed both national and state environmental standards, researchers from Southern Illinois University Carbondale have found.
A three-year study of 43 subwatersheds within the Lower Kaskaskia River basin has revealed that those in urban areas contain on a day-to-day basis significantly higher levels of both E. coli and phosphorus, a major fertilizer component, than do the largely rural, agricultural subwatersheds.
“That surprised me,” said SIUC Assistant Professor of Forestry Jon E. Schoonover, who managed the project. “People have been pointing a finger at agriculture for years as a major source of water pollution, but our study showed that as urbanization increased, so did water quality problems.”
Although some of the subwatersheds studied are less polluted than others, very few are in good shape, the researchers found. Of the 29 in the Silver Creek watershed, which includes Shiloh and O’Fallon as well as the smaller communities of Freeburg and Troy, the team rated only two as good overall. Fifteen received a fair rating, and 12 rated poor. In the Richland Creek watershed, two of 14 subwatersheds merited a good classification, where six received fair ratings and six others rated poor. (To view a roundup of the project and read the entire report, visit kaskaskia.illinoisstate.edu.)
The team’s report does not say where the bacteria and phosphorus are coming from -- that wasn’t within the project’s scope -- but Schoonover and colleague Karl W.J. Williard have their suspicions.
“As far as bacteria is concerned, two possibilities are home septic systems and combined sewer overflows,” Williard said. “If home septic systems are not maintained correctly, they’re not effective. Combined sewer overflows can occur in urban areas where the wastewater collection system combines with stormwater. That combination can overwhelm the treatment plants’ ability to treat all the water. When that happens, water is discharged untreated.”
It’s easy to see the connection between fecal bacteria, faulty water collection systems and leaky septic systems, but there could be a link with phosphorus, too. In urban areas, homeowners and landscapers lay sod atop compacted soils and apply fertilizers spring and fall. Much of it can wash off those compacted lawns, as well as concrete sidewalks and driveways, and into the storm drains. From there, it makes its way to lakes, streams and rivers.
In rural areas, bacteria and phosphorus takes a less direct route, and good conservation practices can lessen their effect still further.
“Farmers who use grassed waterways and buffer strips can reduce phosphorus and bacteria movement to streams,” Schoonover said. “It’s also becoming common for farmers to test their soil to determine the optimum fertilizer application rate to meet plant demands. When you apply only what the plant needs, you don’t get runoff into rivers and streams.”
While water quality assessments played a key role, they comprised only part of the project, said team member Erin L. Seekamp, an SIUC assistant professor of forestry, whose research focuses on the human dimensions of conservation practices and watershed planning.
“We were interested in what community governments can do to improve water quality, what people can do collectively as residents and what they can do at the individual level,” she said. “Those we talked to felt that this project was both logical and timely. They appreciated the integrated aspect.
“One of our key community findings was that residents ranked good water quality as important as social services, education and health care. That was surprising because usually social services rank higher than ecological services.”
More than three-quarters of area residents involved in the study through focus groups or mailed surveys feared that impaired watersheds would degrade wildlife habitat, encourage invasive species, taint wells and make their streams and rivers less beautiful.
They also expressed “moderate to extreme concern” about the social and environmental impacts of development and rapid urbanization -- such things as sprawl, increasing traffic and demands on infrastructure as well as the loss of forest and agricultural land.
Most saw a clear link between water quality and development. In the Richland Creek subwatershed, 94 percent of survey respondents said developers influenced water quality; in Silver Creek, that rose to 97 percent. And they felt strongly about that.
“Residents who responded to our survey indicated it wasn’t OK to put a priority on economic development over water quality, something which some interview, focus group and workshop participants perceive is occurring in their communities,” Seekamp said.
But they didn’t completely let themselves off the hook. Nearly 58 percent of Richland Creek respondents disagreed with the notion that what they did with their land had no effect on water quality, as did almost 59 percent of Silver Creek respondents.
The good news here is that “social capital” -- the web of individual and community connections that produce trust, a sense of belonging and a willingness to help each other -- is a community strength, Seekamp said.
“Collectively, community members perceive they have the power to come together to create change,” she said.
As the project wrapped up, team members held a series of public meetings in August to share their findings and help residents begin to explore possible steps they could take on their own.
“After the Belleville meeting, we witnessed that group process begin,” Seekamp said. “We had broken down our exhibits and packed up our vehicles, and they were still outside the building talking.”