'Not Healthy at All'

As floodwaters begin to recede in some of the most devastated parts of the Midwest, residents there are shifting their focus toward recovery.

But for Michele Kolsrud of Cedar Rapids, Iowa, rebuilding her home seems like a far-away goal. She can't even stand being inside it for long.

"We're only supposed to stay here for half an hour at a time," Kolsrud told ABC News. "So even with masks, we're getting that smell. It's just, it's bad."

As in hundreds of other homes, a layer of toxic sludge has covered everything, brought into the houses after floodwaters ran through gas stations, paint stores, sewage plants and farms that house fertilizer and pesticides. Its pungent smell is the least of homeowners' problems.

"We found some elevated levels of bacteria, e-coli, and some industrial chemicals, some motor oil and diesel fuel," said Michael Wichman, Associate Director of Environmental Health at the University of Iowa, where the sludge was tested.

Even before the test results came back, officials warned residents to be wary of the water.

"If you drink this water and live, tell me about it," Leroy Lippert, chairman of emergency management and homeland security in Des Moines County, Iowa, told The Associated Press on Friday. "You have no idea. It is very, very wise to stay out of it. It's as dangerous as anything."

Even without drinking it, the infectious soup could pose a serious threat.

"Any e-coli exposure is dangerous," Dr. Ryan Sundermann, medical director at Cedar Rapids' St. Luke's Hospital, told ABC News. "It's the most common cause of infectious diarrhea."

Taking a lesson from "the Katrina cough," a respiratory illness caused by inhalation of airborne particles from pervasive mold that was widespread following the Katrina flooding in 2005, officials suggest homeowners wear masks and stay in their homes for only short amounts of time.

"There really is no safe level of mold to breathe in," said Tom Hart of the Linn County, Iowa, Department of Public Health.

Much to the relief of flood victims, health concerns are not the only lesson officials have taken from Katrina and applied in the Midwest.

'Not the FEMA of 2005'

Though the flooding is receding to the north, the Mississippi River continues to make its way south, cresting at various levels along the way.

But officials with the Federal Emergency Management Agency said they are confident that there are "sufficient resources" to handle further flooding.

This is a very different outlook than many had in 2005, when FEMA proved to be ill-prepared to deal with the emergency response necessitated by Hurricane Katrina's devastation of the Gulf Coast.

"The FEMA of today is not the FEMA of 2005. We took the lessons of Katrina and applied them," said Glenn Cannon, FEMA's assistant administrator in the Disaster Operations Directorate. "We have risen to the level that the public expects from us."

Officials claim FEMA is now an "active" agency rather than "reactive," citing the 3.6 million liters of drinking water, nearly 200,000 Meals Ready to Eat (MREs) and nearly 13 million sandbags the government agency and its partners have deployed in flooded or endangered areas.

"They have been trying hard to be proactive throughout this crisis, and had people on site almost immediately after the flooding began," Iowa Lt. Gov. Patty Judge told the AP.

FEMA is also quick to help flood victims financially.