Officials with the U.S. Environmental Protection Agency are spending a second day in Waterloo, investigating the cause of a strange odor at Logan Middle School that forced the school to close last week. Four E.P.A. investigators arrived at the school Wednesday and spent the night taking air samples.

Manuel Schmaedick, the E.P.A.’s on-site coordinator says the odor is extremely transient and there’s currently no odor for them to smell so it’s very hard to make an educated guess about what was causing the problem. About 20 students and nearly a dozen staff members complained of illness last week, when the smell forced the school to close for all or part of three days. Schmaedick says there were no reports of illness at Logan Wednesday.

"That makes it more difficult to pinpoint but at the same time, that transient nature also is a good thing because it shows us that there truly has not been any high concentrations that were observable with the instruments," Schmaedick says. Tests conducted by state and local officials last week found no signs of pollution in the school. Schmaedick says the E.P.A.is using more-advanced equipment to conduct further tests.

He says they’re moving into a phase of looking at any low-level possibilities using the air sampling to search for any concentrations "of anything that we can see." E.P.A.officials plan to monitor the school until test results are complete in about ten days.

Waterloo Schools spokeswoman Sharon Miller says the district has developed contingency plans to relocate Logan’s 350 students if tests show the stink is a health hazard. She says the district does have some buildings available and they’re taking steps to be ready to relocate Logan if need be. 

Radio Iowa