05/04/2007

Sewer gas causes school to close

Odor left several Betsie Valley students ill

By Christine Finger

cfinger@record-eagle.com

THOMPSONVILLE — Officials at Benzie County Central Schools canceled a day of classes at one elementary school after sewer gas drifted into the building and students fell ill.

Superintendent David Micinski said students and staff in one of the classrooms at Betsie Valley Elementary smelled an unpleasant odor several weeks ago that was suspected to be sewer gas, or methane, coming from a roof ventilation system.

Last week, workers made adjustments to the ventilation system that appeared to fix the issue, but on Tuesday several students in the classroom reported experiencing dizziness, nausea and headaches.

Examination at Munson Medical Center determined the students' symptoms could be from exposure to carbon monoxide, but none suffered long-term health effects, Micinski said. Fire and health department tests on Tuesday night did not detect carbon monoxide, but the district called off classes at the school on Wednesday so its architect and engineers could correct the ventilation problem.

"When those kinds of symptoms surfaced, it was in the best interest to take the very precautionary steps that we did,” Micinski said.

Sewer gas is a mixture of toxic and nontoxic gases formed during the decay of household and industrial waste. Carbon monoxide is colorless, odorless and results from incomplete oxidation of carbon in combustion.

Students returned to class on Thursday after health inspectors tested for signs of the problem gases. The district also has installed permanent carbon monoxide detectors.

"We had it checked and checked again,” Micinski said.