"But Weck, a biology professor and gentleman farmer, is concerned about the trouble housing developments have caused his sinkholes. Or, more precisely, the ecological damage from sewage runoff into sinkhole-fed underground streams.
St. Clair County is concerned, too. Hoping to lessen the impact of development, county leaders have targeted sinkhole-prone property for conservation.
Geologist Philip Moss of Waterloo said parts of St. Clair and Monroe counties have the highest concentration of sinkholes in Illinois, an average of about 75 holes per square mile. The holes lead to underground streams, creating unique wildlife habitats. They're often surrounded by a grove of trees and add a rolling quality to the land, attracting developers."It looks pretty," Moss said. "Farmers prefer selling it first because it can't be used very well for farming."But he and other experts say septic systems often don't control enough pollution, letting bacteria seep into the underground streams. That can contaminate wells, meaning some homebuilders will have to add costly water treatment systems.
The choice to protect property, however, will ultimately fall to landowners.
About 40 landowners, Weck included, have already received letters notifying them of tax breaks they can receive if they create conservation areas. Another 200 of the largest landowners, those who own more than 10 acres in the southwestern part of the county, are expected to get letters, too. Weck, who already has land in the program, is considering adding acreage under a state conservation program.Sinkholes in St. Clair and Monroe counties develop in areas known as "karst," a term for land formations of porous rock that have a significant amount of natural seepage. Of the two counties, Monroe has significantly more karst area than St. Clair." (...)
Full article: Stltoday.com