ST. LOUIS (AP) -- Government scientists are evaluating samples of Mississippi River water taken from the area protected by the Birds Point Levee in southeast Missouri to see what sort of contaminants are flowing over fields and into homes following the intentional break.
Bob Holmes, national flood hazard coordinator for the U.S. Geological Survey, told The Associated Press on Friday that water samples were taken in the days immediately after the Army Corps of Engineers used explosives to open a hole in the levee on May 2. The breach lowered the water level at nearby Cairo, Ill., where the flood was threatening to overtop the floodwall and inundate the town of 2,800 residents.
Though Cairo was spared, the breach inundated 130,000 acres of rich Missouri farmland, wiping out a bumper wheat crop and eliminating any hope of producing corn and soybeans for the rest of this year. It also flooded some 100 homes.
Test results aren't expected for several weeks. It's not clear whether they will be used to decide how quickly residents can return to the area or how quickly the land can be used again.
John Schumacher of the USGS office in Rolla, Mo., said scientists are looking at metals, nutrients, bacteria and pesticides flowing into the Birds Point area, as well as the amount of sediment coming down the flooded river.
"Rivers transport what's at the land surface that's there naturally, or that we have put there," Schumacher said. "In a flood event, you have an opportunity for these streams to pick up tremendous volumes of other material."
For example, when a major flood occurs, some sewer systems aren't able to properly treat sewage, which flows into the river. Schumacher said scientists also will evaluate the level of pesticides in the water.
"This is happening during the spring season," Schumacher said. "To have agriculture, we have to use a lot of synthetic chemicals. We could be potentially flushing these things from the fields as the river moves through."
It wasn't immediately clear if the Environmental Protection Agency and the Missouri Department of Natural Resources were also investigating water quality in the area. Phone calls seeking comment from EPA and DNR were not returned.
USGS -- the nation's primary collector of river flow information that is used, in part, to develop flood forecasts -- also is collecting data to gain a better understanding of flooding's impact on water velocity and how the river changes when flooding occurs. Days before the breach at Birds Point, USGS workers installed 38 storm surge sensors developed after Hurricane Katrina and Hurricane Rita to measure water flow into the southeast Missouri floodway.
As tragic as the flood is, USGS officials said, it is providing an opportunity for scientists to better understand the ramifications of the disaster, perhaps informing future flood-fighting efforts.
"Our main mission here is scientific," Schumacher said. "This is a very rare opportunity to characterize what's occurring through the system."
(Copyright 2011 by The Associated Press. All Rights Reserved.)