GRAND FORKS — Grand Forks Central High School students and staff returned to their regular schedule on Tuesday, Nov. 5, after it was determined the smell that sent them all to the gymnasium for an hour was not natural gas, as originally suspected.
Parents and others with ties to the school received an "all clear" message about 10:50 a.m. and were told that the school would continue on a normal schedule for the rest of the day.
Out of caution and as advised by the local fire department, Grand Forks Central students and staff were moved to the gymnasium at about 9:45 a.m. Tuesday when the smell of natural gas was detected at the school.
The school’s boilers, part of the heating system, were turned off.
The Grand Forks Fire Department assessed the building and said students and employees were safe and in no immediate danger. They stayed in the gym until the smell dissipated.
Fire department and Xcel Energy personnel conducted air quality testing. Both groups determined the smell was not natural gas, according to a statement by Jon Strandell, principal at Grand Forks Central High School.
"None of our equipment detected natural gas when we were there," said Mark Nesbit, North Dakota principal manager for Xcel Energy.
"It could be a plumbing problem" or something associated with downtown construction work, possibly affecting a sewer main, Nesbit said.
Strandell said several interviews were conducted with those who smelled the odor and none reported the typical "rotten egg" smell of natural gas.
"We can assure you the smell was not harmful, but was unpleasant," he said in a message sent to parents and others.
Grand Forks Central custodians and other employees of the school district's buildings and grounds division have been checking the floor drains and sewers in the basement at the school and are working to determine the exact location of the issue, Strandell said in the message to parents sent Tuesday afternoon.
Strandell said he and other staff members believe the smell may have been sewer gas.
"There has been no smell present in the building since mid-morning," he said.