University of Illinois researchers are experimenting with grass buffer strips near livestock facilities as way to reduce the risk of ground water contamination by cryptosporidium parvum.

"We found that vegetation can play a significant role in reducing levels of cryptosporidium in surface water," says Prasanta Kalita, agricultural engineer. "Furthermore, our research shows that when cryptosporidium is absorbed into the soil and vegetation, it does not seem to leach down into nearby groundwater."

Cryptosporidium is a single-celled protozoan that can cause severe gastrointestinal illness in humans. It is shed by livestock in their manure and is resistant to water chemical treatment.

U of I researchers are testing buffer strips with variables including rainfall intensity, slope, soil type and grass species.

They found that a filter strip on Catlin soil with a 1.5% slope can retain 98.3% of cryptosporidium in the soil and vegetation. On bare soil, 86% of the parasite is retained.

This summer, researchers will monitor buffer strips under "real-life" conditions, at several livestock facilities. They are also developing computer model to analyze the data and design the optimum buffer system.

For more information, contact Prasanta Kalita at (217) 333-0945 or visit