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Tuesday, August 26, 2008

UI engineers begin yearlong study of flood pollutants in Cedar Rapids Aug. 26

The Flood of 2008 and the pollutants it left in Cedar Rapids, Iowa, will be the focus of a yearlong, $100,000 National Science Foundation (NSF) study by University of Iowa researchers in cooperation with the Linn County Board of Supervisors beginning Tuesday, Aug. 26.

Project principal investigators Keri Hornbuckle and Thanos Papanicolaou, professors of civil and environmental engineering and researchers at IIHR-Hydroscience and Engineering, say that they and about a dozen UI undergraduate and graduate students will begin collecting soil samples from lawns adjacent to roadways and grassy land within the flood zone of the city at 9 a.m. Tuesday, Aug. 26.

"We hope to determine the major sources of the mud and sediments that the flood waters left behind," Hornbuckle said. "We will measure radionuclides, stable isotopes of nitrogen and carbon, and persistent organic pollutants such as PCBs (persistent, toxic industrial chemicals banned decades ago) and chlordanes (insecticides used on lawns, gardens, corn and other crops) in Cedar Rapids sediments to trace the suspension, transport and deposition of sediments within Cedar Rapids.

"Although much of the mud and muck has disappeared, we are confident that the chemicals needed for their research remain," she said. She added that Linda Langston, chair of the Linn County Board of Supervisors, will be a key person in the overview of data collection sites.

Researchers will be equipped with small shovels, sampling jars and bags, GPS units, and clipboards. The goal is to collect about 400 soil samples from grassy areas of the city, with additional sampling conducted in the Cedar River and Cedar Lake via a boat through core sampling and bed load sediment measurements. Used as a cooling lake for the Sixth Street Generating Station and having an average depth of less than four feet, Cedar Lake is especially important because it is contaminated with chlordanes and PCBs.

"The origin of the sediments that now cover the city of Cedar Rapids is the focus of this project. We hypothesize that the sediments originated from at least three major sources including in-stream, stream bank sediments, and Cedar Lake sediments," Hornbuckle said.

Papanicolaou noted that the erosion of bank sediments is a key process in river dynamics, affecting a wide range of physical, ecological and socio-economic issues within a river drainage area and that the impact of bank erosion can be severe and further exacerbated due to flooding.

Hornbuckle and Papanicolaou said that the project and its findings will be of interest to the city as well as their fellow engineers. The project will use state-of-the-art measurement techniques, and the strategy being tested can be used by other researchers to track sediments in similar floods.

The UI researchers are scheduled to report their findings to the National Science Foundation by July 2009.

STORY SOURCE: University of Iowa News Services, 300 Plaza Centre One, Suite 371, Iowa City, Iowa 52242-2500

MEDIA CONTACTS: Keri Hornbuckle, UI College of Engineering, 319-331-3053,; Thanos Papanicolaou, UI College of Engineering, 319-321-0483,; Gary Galluzzo, University News Services, 319-384-0009,

NOTE TO EDITORS: News media are invited to attend the Tuesday, Aug. 26, kick-off of the Cedar Rapids flood pollutants study. UI researchers will meet at 9 a.m. Tuesday, Aug. 26, at the intersection of 3rd Street SE and 11th Avenue SE in Cedar Rapids prior to dispersing throughout the city to collect soil samples at various sites. Reporters can learn the current location of UI researchers by contacting UI Principal Investigator Keri Hornbuckle via cell phone at 319-331-3053.